chore: bump version to 0.14.1

fix(blocklist): retry on transient download failures (#122)

.github/workflows/ci.yml

@@ -3,8 +3,22 @@ name: CI
 on:
   push:
     branches: [main]
+    paths-ignore:
+      - 'site/**'
+      - 'blog/**'
+      - 'drafts/**'
+      - '*.md'
+      - 'scripts/serve-site.sh'
+      - 'scripts/generate-blog-index.sh'
   pull_request:
     branches: [main]
+    paths-ignore:
+      - 'site/**'
+      - 'blog/**'
+      - 'drafts/**'
+      - '*.md'
+      - 'scripts/serve-site.sh'
+      - 'scripts/generate-blog-index.sh'
 
 env:
   CARGO_TERM_COLOR: always
@@ -42,6 +56,8 @@ jobs:
     runs-on: windows-latest
     steps:
       - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
       - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@v2
       - name: build
@@ -55,3 +71,76 @@ jobs:
         with:
           name: numa-windows-x86_64
           path: target/debug/numa.exe
+
+  integration-linux:
+    needs: [check]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - name: build
+        run: cargo build --release
+      - name: install / verify / re-install / uninstall
+        run: |
+          sudo ./target/release/numa install
+          sleep 2
+          curl -sf http://127.0.0.1:5380/health
+          dig @127.0.0.1 example.com +short +timeout=5 | grep -q '.'
+          user=$(ps -o user= -p "$(systemctl show -p MainPID --value numa)" | tr -d ' ')
+          echo "numa running as: $user"
+          test "$user" != "root"
+          sudo ./target/release/numa install
+          sleep 2
+          curl -sf http://127.0.0.1:5380/health
+          sudo ./target/release/numa uninstall
+          sleep 1
+          ! curl -sf http://127.0.0.1:5380/health 2>/dev/null
+      - name: diagnostics on failure
+        if: failure()
+        run: |
+          echo "=== systemctl status numa ==="
+          sudo systemctl status numa --no-pager -l || true
+          echo "=== journalctl -u numa (last 200) ==="
+          sudo journalctl -u numa --no-pager -n 200 || true
+          echo "=== ss -tulnp on 53/80/443/853/5380 ==="
+          sudo ss -tulnp 2>/dev/null | grep -E ':(53|80|443|853|5380)\b' || true
+          echo "=== systemctl is-active systemd-resolved ==="
+          systemctl is-active systemd-resolved || true
+      - name: cleanup
+        if: always()
+        run: |
+          sudo ./target/release/numa uninstall 2>/dev/null || true
+          # systemd-resolved has a ~40s DNS reconfiguration stall after
+          # restart (systemd issue #22521) that breaks the runner agent's
+          # connection to GitHub. Bridge it by replacing the stub-resolv
+          # symlink with a direct upstream — DNS works instantly and the
+          # runner can phone home for post-job steps.
+          sudo rm -f /etc/resolv.conf
+          echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf > /dev/null
+          getent hosts github.com >/dev/null
+
+  integration-macos:
+    needs: [check-macos]
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - name: build
+        run: cargo build --release
+      - name: install / verify / re-install / uninstall
+        run: |
+          sudo ./target/release/numa install
+          sleep 2
+          curl -sf http://127.0.0.1:5380/health
+          dig @127.0.0.1 example.com +short +timeout=5 | grep -q '.'
+          sudo ./target/release/numa install
+          sleep 2
+          curl -sf http://127.0.0.1:5380/health
+          sudo ./target/release/numa uninstall
+          sleep 1
+          ! curl -sf http://127.0.0.1:5380/health 2>/dev/null
+      - name: cleanup
+        if: always()
+        run: sudo ./target/release/numa uninstall 2>/dev/null || true

.github/workflows/docker.yml

@@ -0,0 +1,45 @@
+name: Docker
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: docker/setup-qemu-action@v3
+
+      - uses: docker/setup-buildx-action@v3
+
+      - uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - uses: docker/metadata-action@v5
+        id: meta
+        with:
+          images: ghcr.io/${{ github.repository }}
+          tags: |
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=raw,value=latest
+
+      - uses: docker/build-push-action@v6
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

.github/workflows/publish-aur.yml

@@ -23,6 +23,13 @@ name: Publish - Arch Linux AUR Package
 on:
   push:
     branches: [main]
+    paths-ignore:
+      - 'site/**'
+      - 'blog/**'
+      - 'drafts/**'
+      - '*.md'
+      - 'scripts/serve-site.sh'
+      - 'scripts/generate-blog-index.sh'
   workflow_dispatch:
 
 permissions:

.github/workflows/static.yml

@@ -32,7 +32,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v6
       - name: Install pandoc
-        run: sudo apt-get install -y pandoc
+        uses: pandoc/actions/setup@v1
       - name: Generate blog HTML
         run: make blog
       - name: Setup Pages

.gitignore

@@ -3,3 +3,6 @@
 CLAUDE.md
 docs/
 site/blog/posts/
+ios/
+drafts/
+site/blog/index.html

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "numa"
-version = "0.10.3"
+version = "0.14.1"
 authors = ["razvandimescu <razvan@dimescu.com>"]
 edition = "2021"
 description = "Portable DNS resolver in Rust — .numa local domains, ad blocking, developer overrides, DNS-over-HTTPS"
@@ -10,7 +10,7 @@ keywords = ["dns", "dns-server", "ad-blocking", "reverse-proxy", "developer-tool
 categories = ["network-programming", "development-tools"]
 
 [dependencies]
-tokio = { version = "1", features = ["rt-multi-thread", "macros", "net", "time", "sync"] }
+tokio = { version = "1", features = ["rt-multi-thread", "macros", "net", "time", "sync", "signal"] }
 axum = "0.8"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
@@ -29,12 +29,25 @@ rustls = "0.23"
 tokio-rustls = "0.26"
 arc-swap = "1"
 ring = "0.17"
+odoh-rs = "1"
+psl = "2"
+# rand_core 0.9 matches the version odoh-rs (via hpke 0.13) depends on, so we
+# share one RngCore trait and OsRng impl across the dep tree.
+rand_core = { version = "0.9", features = ["os_rng"] }
 rustls-pemfile = "2.2.0"
+qrcode = { version = "0.14", default-features = false, features = ["svg"] }
+webpki-roots = "1"
+
+[target.'cfg(windows)'.dependencies]
+windows-service = "0.7"
 
 [dev-dependencies]
 criterion = { version = "0.8", features = ["html_reports"] }
 tower = { version = "0.5", features = ["util"] }
 http = "1"
+hickory-resolver = { version = "0.25", features = ["https-ring", "webpki-roots"] }
+hickory-proto = "0.25"
+x509-parser = "0.18"
 
 [[bench]]
 name = "hot_path"
@@ -47,3 +60,7 @@ harness = false
 [[bench]]
 name = "dnssec"
 harness = false
+
+[[bench]]
+name = "recursive_compare"
+harness = false

Dockerfile

@@ -6,6 +6,7 @@ RUN mkdir src && echo 'fn main() {}' > src/main.rs && echo '' > src/lib.rs
 RUN cargo build --release 2>/dev/null || true
 RUN rm -rf src
 COPY src/ src/
+COPY benches/ benches/
 COPY site/ site/
 COPY numa.toml com.numa.dns.plist numa.service ./
 RUN touch src/main.rs src/lib.rs
@@ -13,5 +14,6 @@ RUN cargo build --release
 
 FROM alpine:3.23
 COPY --from=builder /app/target/release/numa /usr/local/bin/numa
+RUN mkdir -p /root/.config/numa && printf '[server]\napi_bind_addr = "0.0.0.0"\n\n[proxy]\nenabled = true\nbind_addr = "0.0.0.0"\n' > /root/.config/numa/numa.toml
 EXPOSE 53/udp 80/tcp 443/tcp 853/tcp 5380/tcp
 ENTRYPOINT ["numa"]

Makefile

@@ -32,6 +32,19 @@ blog:
 		pandoc "$$f" --template=site/blog-template.html -o "site/blog/posts/$$name.html"; \
 		echo "  $$f → site/blog/posts/$$name.html"; \
 	done
+	@scripts/generate-blog-index.sh
+
+blog-drafts: blog
+	@if [ -d drafts ] && ls drafts/*.md >/dev/null 2>&1; then \
+		for f in drafts/*.md; do \
+			name=$$(basename "$$f" .md); \
+			pandoc "$$f" --template=site/blog-template.html -o "site/blog/posts/$$name.html"; \
+			echo "  $$f → site/blog/posts/$$name.html (draft)"; \
+		done; \
+		BLOG_INCLUDE_DRAFTS=1 scripts/generate-blog-index.sh; \
+	else \
+		echo "  No drafts found"; \
+	fi
 
 release:
 ifndef VERSION

PKGBUILD

@@ -9,7 +9,7 @@ url="https://github.com/razvandimescu/numa"
 license=('MIT')
 options=('!lto')
 depends=('gcc-libs' 'glibc')
-makedepends=('cargo' 'git')
+makedepends=('cargo' 'git' 'llvm-libs')
 provides=("$_pkgname")
 conflicts=("$_pkgname")
 backup=('etc/numa.toml')

README.md

@@ -6,9 +6,9 @@
 
 **DNS you own. Everywhere you go.** — [numa.rs](https://numa.rs)
 
-A portable DNS resolver in a single binary. Block ads on any network, name your local services (`frontend.numa`), and override any hostname with auto-revert — all from your laptop, no cloud account or Raspberry Pi required.
+A portable DNS resolver in a single binary. Block ads on any network, name your local services (`frontend.numa`), override any hostname with auto-revert, and seal every outbound query with **ODoH (RFC 9230)** so no single party sees both who you are and what you asked — all from your laptop, no cloud account or Raspberry Pi required.
 
-Built from scratch in Rust. Zero DNS libraries. RFC 1035 wire protocol parsed by hand. Caching, ad blocking, and local service domains out of the box. Optional recursive resolution from root nameservers with full DNSSEC chain-of-trust validation, plus a DNS-over-TLS listener for encrypted client connections (iOS Private DNS, systemd-resolved, etc.). One ~8MB binary, everything embedded.
+Built from scratch in Rust. Zero DNS libraries. Caching, ad blocking, and local service domains out of the box. Optional recursive resolution from root nameservers with full DNSSEC chain-of-trust validation, plus a DNS-over-TLS listener for encrypted client connections (iOS Private DNS, systemd-resolved, etc.). Run `numa relay` and the same binary becomes a public ODoH endpoint too — the curated DNSCrypt list currently has one surviving relay, so every Numa deploy materially expands the ecosystem. One ~8MB binary, everything embedded.
 
 ![Numa dashboard](assets/hero-demo.gif)
 
@@ -27,6 +27,9 @@ yay -S numa-git
 # Windows — download from GitHub Releases
 # All platforms
 cargo install numa
+
+# Docker
+docker run -d --name numa --network host ghcr.io/razvandimescu/numa
 ```
 
 ```bash
@@ -77,6 +80,14 @@ DNSSEC validates the full chain of trust: RRSIG signatures, DNSKEY verification,
 
 ALPN `"dot"` is advertised and enforced in both modes; a handshake with mismatched ALPN is rejected as a cross-protocol confusion defense.
 
+**Phone setup** — point your iPhone or Android at Numa in one step:
+
+```bash
+numa setup-phone
+```
+
+Prints a QR code. Scan it, install the profile, toggle certificate trust — your phone's DNS now routes through Numa over TLS. Requires `[mobile] enabled = true` in `numa.toml`.
+
 ## LAN Discovery
 
 Run Numa on multiple machines. They find each other automatically via mDNS:
@@ -94,6 +105,26 @@ From Machine B: `curl http://api.numa` → proxied to Machine A's port 8000. Ena
 
 **Hub mode**: run one instance with `bind_addr = "0.0.0.0:53"` and point other devices' DNS to it — they get ad blocking + `.numa` resolution without installing anything.
 
+## Docker
+
+```bash
+# Recommended — host networking (Linux)
+docker run -d --name numa --network host ghcr.io/razvandimescu/numa
+
+# Port mapping (macOS/Windows Docker Desktop)
+docker run -d --name numa -p 53:53/udp -p 53:53/tcp -p 5380:5380 ghcr.io/razvandimescu/numa
+```
+
+Dashboard at `http://localhost:5380`. The image binds the API and proxy to `0.0.0.0` by default. Override with a custom config:
+
+```bash
+docker run -d --name numa --network host \
+  -v /path/to/numa.toml:/root/.config/numa/numa.toml \
+  ghcr.io/razvandimescu/numa
+```
+
+Multi-arch: `linux/amd64` and `linux/arm64`.
+
 ## How It Compares
 
 | | Pi-hole | AdGuard Home | Unbound | Numa |
@@ -105,17 +136,22 @@ From Machine B: `curl http://api.numa` → proxied to Machine A's port 8000. Ena
 | DNSSEC validation | — | — | Yes | Yes (RSA, ECDSA, Ed25519) |
 | Ad blocking | Yes | Yes | — | 385K+ domains |
 | Web admin UI | Full | Full | — | Dashboard |
-| Encrypted upstream (DoH) | Needs cloudflared | Yes | — | Native |
+| Encrypted upstream (DoH/DoT) | Needs cloudflared | DoH only | DoT only | DoH + DoT (`tls://`) |
 | Encrypted clients (DoT listener) | Needs stunnel sidecar | Yes | Yes | Native (RFC 7858) |
+| DoH server endpoint | — | Yes | — | Yes (RFC 8484) |
+| Request hedging | — | — | — | All protocols (UDP, DoH, DoT) |
+| Serve-stale + prefetch | — | — | Prefetch at 90% TTL | RFC 8767, prefetch at 90% TTL |
+| Conditional forwarding | — | Yes | Yes | Yes (per-suffix rules) |
 | Portable (laptop) | No (appliance) | No (appliance) | Server | Single binary, macOS/Linux/Windows |
 | Community maturity | 56K stars, 10 years | 33K stars | 20 years | New |
 
 ## Performance
 
-691ns cached round-trip. ~2.0M qps throughput. Zero heap allocations in the hot path. Recursive queries average 237ms after SRTT warmup (12x improvement over round-robin). ECDSA P-256 DNSSEC verification: 174ns. [Benchmarks →](bench/)
+0.1ms cached queries — matches Unbound and AdGuard Home. Wire-level cache stores raw bytes with in-place TTL patching. Request hedging eliminates p99 spikes: cold recursive p99 538ms vs Unbound 748ms (−28%), σ 4× tighter. [Benchmarks →](benches/)
 
 ## Learn More
 
+- [Blog: DNS-over-TLS from Scratch in Rust](https://numa.rs/blog/posts/dot-from-scratch.html)
 - [Blog: Implementing DNSSEC from Scratch in Rust](https://numa.rs/blog/posts/dnssec-from-scratch.html)
 - [Blog: I Built a DNS Resolver from Scratch](https://numa.rs/blog/posts/dns-from-scratch.html)
 - [Configuration reference](numa.toml) — all options documented inline
@@ -126,10 +162,16 @@ From Machine B: `curl http://api.numa` → proxied to Machine A's port 8000. Ena
 - [x] DNS forwarding, caching, ad blocking, developer overrides
 - [x] `.numa` local domains — auto TLS, path routing, WebSocket proxy
 - [x] LAN service discovery — mDNS, cross-machine DNS + proxy
-- [x] DNS-over-HTTPS — encrypted upstream
-- [x] DNS-over-TLS listener — encrypted client connections (RFC 7858, ALPN strict)
+- [x] DNS-over-HTTPS — encrypted upstream + server endpoint (RFC 8484)
+- [x] DNS-over-TLS — encrypted client listener (RFC 7858) + upstream forwarding (`tls://`)
 - [x] Recursive resolution + DNSSEC — chain-of-trust, NSEC/NSEC3
 - [x] SRTT-based nameserver selection
+- [x] Multi-forwarder failover — multiple upstreams with SRTT ranking, fallback pool
+- [x] Request hedging — parallel requests rescue packet loss and tail latency (all protocols)
+- [x] Serve-stale + prefetch — RFC 8767, background refresh at <10% TTL and on stale serve
+- [x] Conditional forwarding — per-suffix rules for split-horizon DNS (Tailscale, VPNs)
+- [x] Cache warming — proactive resolution for configured domains
+- [x] Mobile onboarding — `setup-phone` QR flow, mobile API, mobileconfig profiles
 - [ ] pkarr integration — self-sovereign DNS via Mainline DHT
 - [ ] Global `.numa` names — DHT-backed, no registrar
 

benches/numa-bench-recursive.toml

@@ -0,0 +1,30 @@
+[server]
+bind_addr = "127.0.0.1:5454"
+api_port = 5381
+api_bind_addr = "127.0.0.1"
+data_dir = "/tmp/numa-bench"
+
+[upstream]
+mode = "recursive"
+timeout_ms = 10000
+
+[cache]
+min_ttl = 60
+max_ttl = 3600
+
+[blocking]
+enabled = false
+
+[proxy]
+port = 8080
+tls_port = 8443
+
+[dot]
+enabled = true
+port = 8530
+
+[mobile]
+enabled = false
+
+[lan]
+enabled = false

benches/numa-bench.toml

@@ -0,0 +1,31 @@
+[server]
+bind_addr = "127.0.0.1:5454"
+api_port = 5381
+api_bind_addr = "127.0.0.1"
+data_dir = "/tmp/numa-bench"
+
+[upstream]
+mode = "forward"
+address = ["https://9.9.9.9/dns-query"]
+timeout_ms = 10000
+
+[cache]
+min_ttl = 60
+max_ttl = 3600
+
+[blocking]
+enabled = false
+
+[proxy]
+port = 8080
+tls_port = 8443
+
+[dot]
+enabled = true
+port = 8530
+
+[mobile]
+enabled = false
+
+[lan]
+enabled = false

blog/dns-from-scratch.md

@@ -1,7 +1,7 @@
 ---
 title: I Built a DNS Resolver from Scratch in Rust
 description: How DNS actually works at the wire level — label compression, TTL tricks, DoH, and what surprised me building a resolver with zero DNS libraries.
-date: March 2026
+date: 2026-03-20
 ---
 
 I wanted to understand how DNS actually works. Not the "it translates domain names to IP addresses" explanation — the actual bytes on the wire. What does a DNS packet look like? How does label compression work? Why is everything crammed into 512 bytes?

blog/dnssec-from-scratch.md

@@ -1,7 +1,7 @@
 ---
 title: Implementing DNSSEC from Scratch in Rust
 description: Recursive resolution from root hints, chain-of-trust validation, NSEC/NSEC3 denial proofs, and what I learned implementing DNSSEC with zero DNS libraries.
-date: March 2026
+date: 2026-03-28
 ---
 
 In the [previous post](/blog/posts/dns-from-scratch.html) I covered how DNS works at the wire level — packet format, label compression, TTL caching, DoH. Numa was a forwarding resolver: it parsed packets, did useful things locally, and relayed the rest to Cloudflare or Quad9.
@@ -163,12 +163,12 @@ The fix has three parts:
 
 **TCP fallback.** Every outbound query tries UDP first (800ms timeout). If UDP fails or the response is truncated, retry immediately over TCP. TCP uses a 2-byte length prefix before the DNS message — trivial to implement, and it handles DNSSEC responses that exceed the UDP payload limit.
 
-**UDP auto-disable.** After 3 consecutive UDP failures, flip a global `AtomicBool` and skip UDP entirely — go TCP-first for all queries. This avoids burning 800ms per hop on a network where UDP will never work. The flag resets when the network changes (detected via LAN IP monitoring).
+**UDP auto-disable.** After 3 consecutive UDP failures, flip a global `AtomicBool` and skip UDP entirely — go TCP-first for all queries. The flag resets when the network changes (detected via LAN IP monitoring).
+
+<img src="../hostile-network.svg" alt="Latency profile on a hostile network: queries 1-3 each spend 800ms waiting for a UDP timeout before retrying over TCP, taking 1,100ms total per query. After 3 consecutive failures the UDP auto-disable flag flips, and queries 4+ go TCP-first and complete in 300ms each — 3.7× faster.">
 
 **Query minimization (RFC 7816).** When querying root servers, send only the TLD — `com` instead of `secret-project.example.com`. Root servers handle trillions of queries and are operated by 12 organizations. Minimization reduces what they learn from yours.
 
-The result: on a network that blocks UDP:53, Numa detects the block within the first 3 queries, switches to TCP, and resolves normally at 300-500ms per cold query. Cached queries remain 0ms. No manual config change needed — switch networks and it adapts.
-
 I wouldn't have found this without dogfooding. The code worked perfectly on my home network. It took a real hostile network to expose the assumption that UDP always works.
 
 ## What I learned

blog/dot-from-scratch.md

@@ -0,0 +1,176 @@
+---
+title: DNS-over-TLS from Scratch in Rust
+description: Building RFC 7858 on top of rustls — length-prefix framing, ALPN cross-protocol defense, and two bugs that only the strict clients caught.
+date: 2026-04-06
+---
+
+The [previous post](/blog/posts/dnssec-from-scratch.html) ended with "DoT — the last encrypted transport we don't support." This post is about building it.
+
+Numa now runs a DoT listener on port 853. My iPhone uses it as its system resolver, so ad blocking, DNSSEC validation, and recursive resolution follow my phone through the day. No cloud, no account, no companion app — a self-signed cert, a `.mobileconfig` profile, and a QR code in the terminal.
+
+RFC 7858 is ten pages. The hard parts weren't in the RFC. They were in cross-protocol confusion defenses, a crypto-provider init gotcha that only triggered in one specific config combination, and a certificate SAN bug iOS was happy to accept and `kdig` immediately rejected. This post is about those parts.
+
+## Why DoT when you already have DoH?
+
+Numa has shipped DoH since v0.1. Both protocols tunnel DNS over TLS; DoH wraps queries in HTTP/2, DoT is DNS-over-TCP with TLS in front. Same privacy guarantees, different wrapper.
+
+The answer to "why both" is that **phones ask for DoT by name.** iOS system DNS configures it with two fields (IP + server name) instead of a URL template. Android 9+ "Private DNS" speaks DoT natively. Linux stubs default to DoT. I wanted my phone on Numa without installing anything on the phone itself, and DoT is the protocol iOS and Android already speak for that.
+
+## The wire format is refreshingly small
+
+RFC 7858 is one sentence of wire protocol: *DNS-over-TCP (RFC 1035 §4.2.2) with TLS in front, on port 853.* DNS-over-TCP has existed since 1987 — a 2-byte length prefix followed by the DNS message. DoT is that, wrapped in a TLS session. The entire framing code is seven lines:
+
+```rust
+async fn write_framed<S>(stream: &mut S, msg: &[u8]) -> io::Result<()>
+where S: AsyncWriteExt + Unpin {
+    let mut out = Vec::with_capacity(2 + msg.len());
+    out.extend_from_slice(&(msg.len() as u16).to_be_bytes());
+    out.extend_from_slice(msg);
+    stream.write_all(&out).await?;
+    stream.flush().await
+}
+```
+
+Reads are symmetric: `read_exact` two bytes, convert to `u16`, `read_exact` that many bytes. No HTTP headers, no chunked encoding, no framing layer.
+
+## Persistent connections
+
+A fresh TCP+TLS handshake is at least 3 RTTs — about 300ms on a 100ms connection, 60× the cost of a UDP query. RFC 7858 §3.4 says clients SHOULD reuse the TCP connection for multiple queries, and every real DoT client does: iOS, Android, systemd, stubby. A single connection often carries hundreds of queries.
+
+<img src="../dot-handshake.svg" alt="Timing diagram comparing a DNS lookup over plain UDP (1 RTT), over DoT on a fresh connection (3 RTTs — TCP handshake, TLS 1.3 handshake, then the query), and over a reused DoT session (1 RTT, same as UDP).">
+
+The amortization point is the whole game. If you only ever do one query per connection, DoT is roughly 3× slower than UDP and you should not use it. If you reuse the same TLS session for a browsing session's worth of queries, the handshake is paid once and every subsequent query is effectively free.
+
+The server is a loop that reads a length-prefixed message, resolves it, writes the response framed the same way, waits for the next one. Three timeouts keep it honest:
+
+- **Handshake timeout (10s)** — a slowloris that opens TCP but never sends a ClientHello can't pin a worker.
+- **Idle timeout (30s)** — a connected client with nothing to say gets dropped.
+- **Write timeout (10s)** — a stalled reader can't hold a response buffer indefinitely.
+
+A semaphore caps concurrent connections at 512 so a burst of handshakes can't exhaust the tokio runtime.
+
+## ALPN, the cross-protocol defense that matters
+
+If DoT lives on port 853 and HTTPS on 443, what stops an HTTP/2 client from hitting 853 and getting confused replies? [Cross-protocol attacks](https://alpaca-attack.com/) exist and have had real CVEs. The defense is ALPN: during the TLS handshake the client advertises protocols, the server picks one it supports or fails. A DoT server advertises `"dot"`; a client offering only `"h2"` gets a `no_application_protocol` fatal alert before any frames are exchanged.
+
+rustls enforces this by default when you set `alpn_protocols`:
+
+```rust
+let mut config = ServerConfig::builder()
+    .with_no_client_auth()
+    .with_single_cert(certs, key)?;
+config.alpn_protocols = vec![b"dot".to_vec()];
+```
+
+"The library enforces it by default" has a latent risk: a future rustls upgrade could change the default, and the defense would quietly evaporate. I wrote a test that pins the behavior so any regression in a dependency update fails loudly:
+
+```rust
+#[tokio::test]
+async fn dot_rejects_non_dot_alpn() {
+    let (addr, cert_der) = spawn_dot_server().await;
+    let client_config = dot_client(&cert_der, vec![b"h2".to_vec()]);
+    let connector = tokio_rustls::TlsConnector::from(client_config);
+    let tcp = tokio::net::TcpStream::connect(addr).await.unwrap();
+    let result = connector
+        .connect(ServerName::try_from("numa.numa").unwrap(), tcp)
+        .await;
+    assert!(result.is_err(),
+        "DoT server must reject ALPN that doesn't include \"dot\"");
+}
+```
+
+When you're leaning on a library's default for a security-critical invariant, the test is the contract.
+
+## Two bugs that hid for days
+
+Both were fixed before v0.10 shipped. Both stayed hidden because my initial tests used *permissive* clients.
+
+### The rustls crypto provider panic
+
+rustls 0.23 requires a `CryptoProvider` installed before you can build a `ServerConfig`. Numa's HTTPS proxy calls `install_default` as a side effect when it builds its own config, so DoT "just worked" for users who enabled both — the proxy had already initialized the provider before DoT's first handshake.
+
+Then I added support for user-provided DoT certificates. Someone running DoT with their own Let's Encrypt cert, with the HTTPS proxy disabled, would hit:
+
+```
+thread 'dot' panicked at rustls-0.23.25/src/crypto/mod.rs:185:14:
+no process-level CryptoProvider available -- call
+CryptoProvider::install_default() before this point
+```
+
+The panic happened on the first client connection, not at startup. While writing the integration suite for "DoT with BYO cert, proxy disabled" — the one combination nobody had ever actually exercised — the first run panicked. Fix is two lines: call `install_default` inside `load_tls_config` so DoT can stand alone. If a side effect initializes something and you have a path that skips that side effect, you have a bug waiting for a specific deployment.
+
+### The SAN bug iOS was happy to accept
+
+Numa's self-signed DoT cert is generated on first run from a local CA alongside the data directory. It needs to match whatever `ServerName` the client sends as SNI. For the HTTPS proxy, that's the wildcard domain pattern `*.numa` (matching `frontend.numa`, `api.numa`, etc.). I initially reused the same SAN list for DoT: a wildcard `*.numa` and nothing else.
+
+On an iPhone this worked perfectly. Full browsing session, persistent connections in the log, ad blocking active. I was about to merge when I ran one last smoke test with `kdig` (GnuTLS-backed, from [Knot DNS](https://www.knot-dns.cz/)):
+
+```
+$ kdig @192.168.1.16 -p 853 +tls \
+    +tls-ca=/usr/local/var/numa/ca.pem \
+    +tls-hostname=numa.numa example.com A
+
+;; TLS, handshake failed (Error in the certificate.)
+```
+
+Huh.
+
+[RFC 6125 §6.4.3](https://datatracker.ietf.org/doc/html/rfc6125#section-6.4.3): a wildcard in a certificate's DNS-ID matches exactly one label. `*.numa` matches `frontend.numa`, but not `numa.numa`, because the wildcard wants at least one label to substitute and strict clients reject wildcards in the leftmost label under single-label TLDs as ambiguous.
+
+iOS's TLS stack is lenient and accepts it. GnuTLS, NSS (Firefox), and most non-Apple validators don't. The fix is five lines — add an explicit `numa.numa` SAN alongside the wildcard. But the lesson is the one that stuck: I wrote a commit message saying "fix an iOS bug" and had to rewrite it, because iOS was fine. The real bug was that every GnuTLS/NSS-based client on the planet would have rejected the cert, and I only found it by running one more test with a stricter tool.
+
+> Test with the strict client. The permissive client hides your bugs.
+
+## Getting your phone onto it
+
+A DoT server is useless without a way to point a phone at it. iOS won't let you type an IP and a server name into Settings directly — you install a `.mobileconfig` profile that bundles the CA as a trust anchor and the DNS settings in a single payload.
+
+Numa ships a subcommand that builds one on the fly and serves it over a QR code in the terminal:
+
+```
+$ numa setup-phone
+
+  Numa Phone Setup
+
+  Profile URL: http://192.168.1.10:8765/mobileconfig
+
+  ██████████████████████████████
+  ██                          ██
+  ██   [QR code rendered in   ██
+  ██    your terminal]        ██
+  ██                          ██
+  ██████████████████████████████
+
+  On your iPhone:
+    1. Open Camera, point at the QR code, tap the yellow banner
+    2. Allow the download when Safari asks
+    3. Open Settings — tap "Profile Downloaded" near the top
+       (or: Settings → General → VPN & Device Management → Numa DNS)
+    4. Tap Install (top right), enter passcode, Install again
+    5. Settings → General → About → Certificate Trust Settings
+       Toggle ON "Numa Local CA" — required for DoT to work
+```
+
+The same QR is available in the dashboard — click "Phone Setup" in the header and the popover renders an SVG QR code pointing at the mobileconfig URL. On mobile viewports it shows a direct download link instead.
+
+<img src="../phone-setup-dashboard.png" alt="Numa dashboard with Phone Setup popover showing QR code and install instructions">
+
+Step 4 is non-negotiable. Even though the CA is bundled in the same profile that installs the DNS settings, iOS still requires the user to explicitly toggle trust in Certificate Trust Settings. It's a deliberate iOS policy to prevent profile-based trust injection — annoying, and correct.
+
+I've been dogfooding this since v0.10 shipped in early April. The phone resolves through Numa over DoT whenever I'm home; persistent connections are visible in the log as a single source port living through dozens of queries. The one real caveat: if the laptop's LAN IP changes, the profile breaks. [RFC 9462 DDR](https://datatracker.ietf.org/doc/html/rfc9462) fixes that — Numa can respond to `_dns.resolver.arpa IN SVCB` with its current IP and iOS picks it up on each network join. Next piece of work.
+
+## What I learned
+
+**RFC-level small, API-level hard.** RFC 7858 is ten pages. The framing is trivial. But the subtle stuff — ALPN, timeouts, connection caps, handshake vs idle vs write deadlines, backoff on accept errors — isn't in the RFC. Miss any of it and you leak a DoS vector or a protocol confusion hole.
+
+**Your test matrix is your security matrix.** Both bugs in this post were hidden by lenient clients. In both cases the strict client — kdig, or a specific config combination — surfaced the bug instantly. Pick test tools for strictness, not convenience. The moment you find yourself thinking "but iOS accepts it," stop and run kdig.
+
+**Don't initialize global state via side effects.** "Module A installs a global, module B silently depends on it, disabling A breaks B" is a bug pattern that keeps coming back. Fix: have module B initialize its dependency explicitly, even if it means calling an idempotent `install_default` twice. The dependency graph should be local and obvious.
+
+## What's next
+
+- ~~**DoH server**~~ — shipped in v0.12.0. `POST /dns-query` accepts [RFC 8484](https://datatracker.ietf.org/doc/html/rfc8484) wire-format queries, so Firefox/Chrome can point their built-in DoH at Numa.
+- **DoQ server (RFC 9250)** — DNS over QUIC. Android 14+ supports it natively.
+- **DDR (RFC 9462)** — auto-discovery via `_dns.resolver.arpa IN SVCB`, so phones pick up a moved Numa instance without the installed profile going stale.
+
+The code is at [github.com/razvandimescu/numa](https://github.com/razvandimescu/numa) — the DoT listener is in [`src/dot.rs`](https://github.com/razvandimescu/numa/blob/main/src/dot.rs) and the phone onboarding flow is in [`src/setup_phone.rs`](https://github.com/razvandimescu/numa/blob/main/src/setup_phone.rs) and [`src/mobileconfig.rs`](https://github.com/razvandimescu/numa/blob/main/src/mobileconfig.rs). MIT license.

blog/fixing-doh-tail-latency.md

@@ -0,0 +1,171 @@
+---
+title: Fixing DNS tail latency with a 5-line config and a 50-line function
+description: Periodic 40-140ms DoH spikes from hyper's dispatch channel. The fix was reqwest window tuning and request hedging — Dean & Barroso's "The Tail at Scale," applied to a DNS forwarder. Same ideas took cold recursive p99 from 2.3 seconds to 538ms.
+date: 2026-04-12
+---
+
+If you're using reqwest for small HTTP/2 payloads, you probably have a tail latency problem you don't know about. Hyper's default flow control windows are 10,000× oversized for anything under 1 KB, and its dispatch channel adds periodic 40-140ms stalls that don't show up in median benchmarks.
+
+I hit this building Numa's DoH forwarding path. Median was 10ms, mean was 23ms — the tail was dragging everything.
+
+<div class="hero-metrics">
+<div class="metric-card">
+<div class="metric-vs">DoH forwarding p99</div>
+<div class="metric-value">113 → 71ms</div>
+<div class="metric-label">window tuning + request hedging</div>
+</div>
+<div class="metric-card">
+<div class="metric-vs">Cold recursive p99</div>
+<div class="metric-value">2.3s → 538ms</div>
+<div class="metric-label">NS caching, serve-stale, parallel queries</div>
+</div>
+<div class="metric-card">
+<div class="metric-vs">Forwarding σ</div>
+<div class="metric-value">31 → 13ms</div>
+<div class="metric-label">random spikes become parallel races</div>
+</div>
+</div>
+
+The fix was a 5-line reqwest config and a 50-line hedging function. This post is also an advertisement for Dean & Barroso's 2013 paper ["The Tail at Scale"](https://research.google/pubs/pub40801/) — a decade-old idea that still demolishes dispatch spikes. The same ideas later took my cold recursive p99 from 2.3 seconds to 538ms.
+
+---
+
+## The cause: hyper's dispatch channel
+
+Reqwest sits on top of hyper, which interposes an mpsc dispatch channel and a separate `ClientTask` between `.send()` and the h2 stream. I instrumented the forwarding path and confirmed: 100% of the spike time lives in the `send()` phase, and a parallel heartbeat task showed zero runtime lag during spikes. The tokio runtime was fine — the stall was internal to hyper's request scheduling.
+
+Hickory-resolver doesn't have this issue. It holds `h2::SendRequest<Bytes>` directly and calls `ready().await; send_request()` in the caller's task — no channel, no scheduling dependency. I used it as a reference point throughout.
+
+## Fix #1 — HTTP/2 window sizes
+
+Reqwest inherits hyper's HTTP/2 defaults: 2 MB stream window, 5 MB connection window. For DNS responses (~200 bytes), that's ~10,000× oversized — unnecessary WINDOW_UPDATE frames, bloated bookkeeping on every poll, and different server-side scheduling behavior.
+
+Setting both windows to the h2 spec default (64 KB) dropped my median from 13.3ms to 10.1ms:
+
+```rust
+reqwest::Client::builder()
+    .use_rustls_tls()
+    .http2_initial_stream_window_size(65_535)
+    .http2_initial_connection_window_size(65_535)
+    .http2_keep_alive_interval(Duration::from_secs(15))
+    .http2_keep_alive_while_idle(true)
+    .http2_keep_alive_timeout(Duration::from_secs(10))
+    .pool_idle_timeout(Duration::from_secs(300))
+    .pool_max_idle_per_host(1)
+    .build()
+```
+
+**Any Rust code using reqwest for tiny-payload HTTP/2 workloads — DoH, API polling, metric scraping — is probably hitting this.**
+
+## Fix #2 — Request hedging
+
+["The Tail at Scale"](https://research.google/pubs/pub40801/) (Dean & Barroso, 2013): fire a request, and if it doesn't return within your P50 latency, fire the same request in parallel. First response wins.
+
+The intuition: if 5% of requests spike due to independent random events, two parallel requests means only 0.25% of pairs spike on *both*. The tail collapses.
+
+**The surprise: hedging against the same upstream works.** HTTP/2 multiplexes streams — two `send_request()` calls on one connection become independent h2 streams. If one stalls in the dispatch channel, the other keeps making progress.
+
+```rust
+pub async fn forward_with_hedging_raw(
+    wire: &[u8],
+    primary: &Upstream,
+    secondary: &Upstream,
+    hedge_delay: Duration,
+    timeout_duration: Duration,
+) -> Result<Vec<u8>> {
+    let primary_fut = forward_query_raw(wire, primary, timeout_duration);
+    tokio::pin!(primary_fut);
+    let delay = sleep(hedge_delay);
+    tokio::pin!(delay);
+
+    // Phase 1: wait for primary to return OR the hedge delay.
+    tokio::select! {
+        result = &mut primary_fut => return result,
+        _ = &mut delay => {}
+    }
+
+    // Phase 2: hedge delay expired — fire secondary, keep primary alive.
+    let secondary_fut = forward_query_raw(wire, secondary, timeout_duration);
+    tokio::pin!(secondary_fut);
+
+    // First successful response wins.
+    tokio::select! {
+        r = primary_fut => r,
+        r = secondary_fut => r,
+    }
+}
+```
+
+The [production version](https://github.com/razvandimescu/numa/blob/main/src/forward.rs#L267) adds error handling — if one leg fails, it waits for the other. In production, Numa passes the same `&Upstream` twice when only one is configured. I extended hedging to all protocols — UDP (rescues packet loss on WiFi), DoT (rescues TLS handshake stalls). Configurable via `hedge_ms`; set to 0 to disable.
+
+**Caveat: hedging hurts on degraded networks.** When latency is consistently high (no random spikes, just slow), the hedge adds overhead with nothing to rescue. Hedging is a variance reducer, not a latency reducer — it only helps when spikes are *random*.
+
+---
+
+## Forwarding results
+
+5 iterations × 101 domains × 10 rounds, 5,050 samples per method. Hickory-resolver included as a reference (it uses h2 directly, no dispatch channel):
+
+| | Single | **Hedged** | Hickory (ref) |
+|---|---|---|---|
+| mean | 17.4ms | **14.3ms** | 16.8ms |
+| median | 10.4ms | **10.2ms** | 13.3ms |
+| p95 | 52.5ms | **28.6ms** | 37.7ms |
+| p99 | 113.4ms | **71.3ms** | 98.1ms |
+| σ | 30.6ms | **13.2ms** | 19.1ms |
+
+The internal improvement: hedging cut p95 by 45%, p99 by 37%, σ by 57%. The exact margin vs hickory varies with network conditions; the σ reduction is consistent across runs.
+
+## Recursive resolution: from 2.3 seconds to 538ms
+
+Forwarding is one job. Recursive resolution — walking from root hints through TLD nameservers to the authoritative server — is a different one. I started 15× behind Unbound on cold recursive p99 and traced it to four root causes.
+
+**1. Missing NS delegation caching.** I cached glue records (ns1's IP) but not the delegation itself. Every `.com` query walked from root. Fix: cache NS records from referral authority sections. (10 lines)
+
+**2. Expired cache entries caused full cold resolutions.** Fix: serve-stale ([RFC 8767](https://www.rfc-editor.org/rfc/rfc8767)) — return expired entries with TTL=1 while revalidating in the background. (20 lines)
+
+**3. Wasting 1,900ms per unreachable server.** 800ms UDP timeout + unconditional 1,500ms TCP fallback. Fix: 400ms UDP, TCP only for truncation. (5 lines)
+
+**4. Sequential NS queries on cold starts.** Fix: fire to the top 2 nameservers simultaneously. First response wins, SRTT recorded for both. Same hedging principle. (50 lines)
+
+<div class="before-after">
+<div class="ba-item">
+<div class="ba-label">p99 before</div>
+<div class="ba-value ba-before">2,367ms</div>
+</div>
+<div class="ba-arrow">&#8594;</div>
+<div class="ba-item">
+<div class="ba-label">p99 after</div>
+<div class="ba-value ba-after">538ms</div>
+</div>
+<div class="ba-item ba-ref">
+<div class="ba-label">Unbound (ref)</div>
+<div class="ba-value">748ms</div>
+</div>
+</div>
+
+Genuine cold benchmarks — unique subdomains, 1 query per domain, 5 iterations, 505 samples per server:
+
+| | Baseline | Final | Unbound (ref) |
+|---|---|---|---|
+| p99 | 2,367ms | **538ms** | 748ms |
+| σ | 254ms | **114ms** | 457ms |
+| median | — | 77.6ms | 74.7ms |
+
+Unbound wins median by ~4%. Where hedging shines is the tail — domains with slow or unreachable nameservers, where parallel queries turn worst-case sequential timeouts into races. Cache hits are tied at 0.1ms across Numa, Unbound, and AdGuard Home.
+
+What I'm exploring next: persistent SRTT data across restarts (currently cold-starts lose all server timing), aggressive NSEC caching to shortcut negative lookups, and adaptive hedge delays that tune themselves to observed network conditions instead of a fixed 10ms.
+
+---
+
+## Takeaways
+
+The real hero of this post is Dean & Barroso. Hedging works because **spikes are random, and two random draws rarely both lose**. It's effective for any HTTP/2 client, any language, any forwarder topology. Nobody we know of ships it by default.
+
+If you're building a Rust service that makes many small HTTP/2 requests to the same backend: check your flow control window sizes first, then implement hedging. Don't rewrite the client.
+
+Benchmarks are in [`benches/recursive_compare.rs`](https://github.com/razvandimescu/numa/blob/main/benches/recursive_compare.rs) — run them yourself. If you're using reqwest for tiny-payload workloads and try the window size fix, I'd love to hear if you see the same improvement.
+
+---
+
+Numa is a DNS resolver that runs on your laptop or phone. DoH, DoT, .numa local domains, ad blocking, developer overrides, a REST API, and all the optimization work in this post. [github.com/razvandimescu/numa](https://github.com/razvandimescu/numa).

build.rs

@@ -0,0 +1,48 @@
+fn main() {
+    // --long forces "TAG-N-gSHA[-dirty]" format even on exact tag matches,
+    // making parsing unambiguous for pre-release tags like v0.14.0-rc1.
+    let git_version = std::process::Command::new("git")
+        .args(["describe", "--tags", "--always", "--dirty", "--long"])
+        .output()
+        .ok()
+        .filter(|o| o.status.success())
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .and_then(|raw| parse_git_describe(raw.trim()));
+
+    if let Some(v) = git_version {
+        println!("cargo:rustc-env=NUMA_BUILD_VERSION={}", v);
+    }
+
+    println!("cargo:rerun-if-changed=.git/HEAD");
+}
+
+/// Parse `git describe --long` output into a SemVer-compatible string.
+///   "v0.13.1-0-ga87f907"          → "0.13.1"
+///   "v0.13.1-9-ga87f907"          → "0.13.1+a87f907"
+///   "v0.14.0-rc1-0-ga87f907"      → "0.14.0-rc1"
+///   "v0.14.0-rc1-3-ga87f907-dirty" → "0.14.0-rc1+a87f907-dirty"
+///   "a87f907"                      → "0.0.0+a87f907"
+fn parse_git_describe(s: &str) -> Option<String> {
+    let s = s.strip_prefix('v').unwrap_or(s);
+    let dirty = s.ends_with("-dirty");
+    let s = s.strip_suffix("-dirty").unwrap_or(s);
+
+    // --long format: TAG-N-gSHA. Split from the right so tags with hyphens work.
+    let gpos = s.rfind("-g")?;
+    let sha = &s[gpos + 2..];
+    let rest = &s[..gpos];
+    let npos = rest.rfind('-')?;
+    let n: u32 = rest[npos + 1..].parse().ok()?;
+    let tag = &rest[..npos];
+
+    if tag.is_empty() {
+        return Some(format!("0.0.0+{}", sha));
+    }
+
+    Some(match (n, dirty) {
+        (0, false) => tag.to_string(),
+        (0, true) => format!("{}+{}-dirty", tag, sha),
+        (_, false) => format!("{}+{}", tag, sha),
+        (_, true) => format!("{}+{}-dirty", tag, sha),
+    })
+}

numa.service

@@ -8,6 +8,39 @@ Type=simple
 ExecStart={{exe_path}}
 Restart=always
 RestartSec=2
+
+# Transient system user per start; no PKGBUILD/sysusers setup required.
+# systemd remaps the StateDirectory ownership to the dynamic UID on each
+# launch, including legacy root-owned trees from pre-drop installs.
+DynamicUser=yes
+
+AmbientCapabilities=CAP_NET_BIND_SERVICE
+CapabilityBoundingSet=CAP_NET_BIND_SERVICE
+
+StateDirectory=numa
+StateDirectoryMode=0750
+ConfigurationDirectory=numa
+ConfigurationDirectoryMode=0755
+
+# Sandboxing — conservative set known to work with Rust network daemons.
+# Aggressive hardening (MemoryDenyWriteExecute, SystemCallFilter, seccomp
+# allow-lists) can be layered on once tested in isolation.
+NoNewPrivileges=true
+ProtectSystem=strict
+# DynamicUser= sets ProtectHome=read-only by default — leaves /home
+# readable so systemd can exec binaries installed under it (cargo install,
+# source builds), while blocking writes to user $HOMEs. Don't set =yes:
+# that hides /home entirely and fails with status=203/EXEC.
+PrivateTmp=true
+PrivateDevices=true
+ProtectKernelTunables=true
+ProtectKernelModules=true
+ProtectControlGroups=true
+RestrictRealtime=true
+RestrictSUIDSGID=true
+# AF_NETLINK for interface enumeration on network changes
+RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX AF_NETLINK
+
 StandardOutput=journal
 StandardError=journal
 SyslogIdentifier=numa

numa.toml

@@ -8,15 +8,32 @@ api_port = 5380
                               # %PROGRAMDATA%\numa on windows. Override for
                               # containerized deploys or tests that can't
                               # write to the system path.
+# filter_aaaa = true          # on IPv4-only networks, answer AAAA queries with
+                              # NODATA (NOERROR + empty answer) so Happy Eyeballs
+                              # clients don't wait on a v6 attempt that can't
+                              # succeed. Also strips `ipv6hint` from HTTPS/SVCB
+                              # records (RFC 9460) so modern browsers (Chrome
+                              # ≥103, Firefox, Safari) don't bypass the AAAA
+                              # filter via SVCB hints. Local zones, overrides,
+                              # and the .numa proxy are NOT filtered — you can
+                              # still configure v6 records for local services.
+                              # Default: false.
 
 # [upstream]
 # mode = "forward"                              # "forward" (default) — relay to upstream
 #                                               # "recursive" — resolve from root hints (no address needed)
+# address = "9.9.9.9"                           # single upstream (plain UDP)
+# address = ["192.168.1.1", "9.9.9.9:5353"]    # multiple upstreams — SRTT picks fastest
 # address = "https://dns.quad9.net/dns-query"   # DNS-over-HTTPS (encrypted)
-# address = "https://cloudflare-dns.com/dns-query"  # Cloudflare DoH
-# address = "9.9.9.9"                           # plain UDP
-# port = 53                                     # only for forward mode, plain UDP
+# address = "tls://9.9.9.9#dns.quad9.net"       # DNS-over-TLS (encrypted, port 853)
+# fallback = ["8.8.8.8", "1.1.1.1"]            # tried only when all primaries fail
+# port = 53                                     # default port for addresses without :port
 # timeout_ms = 3000
+# hedge_ms = 10                                  # request hedging delay (ms). After this delay
+#                                                # without a response, fires a parallel request
+#                                                # to the same upstream. Rescues packet loss (UDP),
+#                                                # dispatch spikes (DoH), TLS stalls (DoT).
+#                                                # Set to 0 to disable. Default: 10
 # root_hints = [                                # only used in recursive mode
 #     "198.41.0.4",      # a.root-servers.net (Verisign)
 #     "199.9.14.201",    # b.root-servers.net (USC-ISI)
@@ -44,6 +61,29 @@ api_port = 5380
 #     "co", "br", "au", "ca", "jp",             # other major ccTLDs
 # ]
 
+# [[forwarding]]                                  # per-suffix conditional forwarding rules
+# suffix = "168.192.in-addr.arpa"                  # single suffix → one upstream
+# upstream = "100.90.1.63:5361"
+#
+# [[forwarding]]
+# suffix = ["home.local", "home.arpa"]             # multiple suffixes → same upstream
+# upstream = "10.0.0.1"                            # port 53 default
+#
+# [[forwarding]]                                    # DoT upstream: tls://IP[:port]#hostname
+# suffix = ["google.com", "goog"]                   # hostname is the TLS SNI / cert name
+# upstream = "tls://9.9.9.9#dns.quad9.net"          # port 853 default
+#
+# [[forwarding]]                                    # DoH upstream: full https:// URL
+# suffix = "example.corp"
+# upstream = "https://dns.quad9.net/dns-query"
+#
+# [[forwarding]]                                    # array of upstreams → SRTT-aware failover
+# suffix = ["google.com", "goog"]                   # fastest-healthy first, dead one skipped
+# upstream = [
+#     "tls://9.9.9.9#dns.quad9.net",
+#     "tls://149.112.112.112#dns.quad9.net",
+# ]
+
 # [blocking]
 # enabled = true               # set to false to disable ad blocking
 # refresh_hours = 24
@@ -51,9 +91,10 @@ api_port = 5380
 # allowlist = ["example.com"]  # domains to never block
 
 [cache]
-max_entries = 10000
+max_entries = 100000
 min_ttl = 60
 max_ttl = 86400
+# warm = ["google.com", "github.com"]  # resolve at startup, refresh before TTL expiry
 
 [proxy]
 enabled = true
@@ -91,7 +132,7 @@ tld = "numa"
 
 # DNS-over-TLS listener (RFC 7858) — encrypted DNS on port 853
 # [dot]
-# enabled = false             # opt-in: accept DoT queries
+# enabled = true              # on by default; set false to disable
 # port = 853                  # standard DoT port
 # bind_addr = "0.0.0.0"       # IPv4 or IPv6; unspecified binds all interfaces
 # cert_path = "/etc/numa/dot.crt"  # PEM cert; omit to use self-signed (proxy CA if available)
@@ -102,3 +143,22 @@ tld = "numa"
 # enabled = true              # discover other Numa instances via mDNS (_numa._tcp.local)
 # broadcast_interval_secs = 30
 # peer_timeout_secs = 90
+
+# Mobile API — persistent HTTP listener serving read-only routes
+# (/health, /ca.pem, /mobileconfig, /ca.mobileconfig) on a LAN-reachable
+# port. Consumed by the iOS/Android companion apps for discovery and
+# profile fetching, and by `numa setup-phone` for QR-based onboarding.
+#
+# Opt-in because the listener binds to the LAN by default. None of the
+# exposed routes are cryptographically sensitive (no private keys, no
+# state mutations, all idempotent GETs), but enabling it does add a new
+# listener to any device on the LAN that scans port 8765.
+#
+# Safe for home LANs. Think twice before enabling on untrusted LANs
+# (office Wi-Fi, coffee shops, etc.) — an attacker on the same network
+# could run a competing Numa instance that shadows yours via mDNS and
+# trick companion apps into installing their profile instead of yours.
+[mobile]
+enabled = true                # opt-in to the mobile API listener
+# port = 8765                 # default; matches Discovery.swift defaultAPIPort
+# bind_addr = "0.0.0.0"       # default; set to "127.0.0.1" for localhost-only

packaging/relay/Caddyfile

@@ -0,0 +1,15 @@
+odoh-relay.example.com {
+    handle /relay {
+        reverse_proxy numa-relay:8443
+    }
+    handle /health {
+        reverse_proxy numa-relay:8443
+    }
+    respond 404
+
+    # Per-request access logs defeat the point of an oblivious relay.
+    # Aggregate counters are exposed at /health on the relay itself.
+    log {
+        output discard
+    }
+}

packaging/relay/README.md

@@ -0,0 +1,48 @@
+# Numa ODoH Relay — Docker deploy
+
+Two-container deploy: Caddy terminates TLS (auto-provisioning a Let's Encrypt
+cert via ACME) and reverse-proxies to a Numa relay running on an internal
+Docker network. The relay never reads sealed payloads; Caddy never logs them.
+
+## Prerequisites
+
+- A host with public 80/443 reachable from the internet.
+- A DNS record (`A` or `AAAA`) pointing your chosen hostname at the host.
+- Docker + Docker Compose v2.
+
+## Configure
+
+Edit `Caddyfile` and replace `odoh-relay.example.com` with your hostname.
+That hostname is what ACME validates against and what ODoH clients will
+configure as their relay URL: `https://<hostname>/relay`.
+
+## Deploy
+
+```sh
+docker compose up -d
+docker compose logs -f caddy   # watch ACME provisioning
+```
+
+First boot takes a few seconds while Caddy obtains the cert. Subsequent
+restarts reuse the cached cert from the `caddy_data` volume.
+
+## Verify
+
+```sh
+curl https://<hostname>/health
+# ok
+# total 0
+# forwarded_ok 0
+# forwarded_err 0
+# rejected_bad_request 0
+```
+
+Then point any ODoH client at `https://<hostname>/relay` and watch the
+counters tick.
+
+## Listing on the public ecosystem
+
+DNSCrypt's [v3/odoh-relays.md](https://github.com/DNSCrypt/dnscrypt-resolvers/blob/master/v3/odoh-relays.md)
+is the canonical list. The pruned 2025-09-16 commit shows one public ODoH
+relay survived the cull — running this compose file doubles global supply.
+Open a PR there once your relay has been up for ~24 hours.

packaging/relay/docker-compose.yml

@@ -0,0 +1,26 @@
+services:
+  numa-relay:
+    image: ghcr.io/razvandimescu/numa:latest
+    command: ["relay", "8443", "0.0.0.0"]
+    restart: unless-stopped
+    networks: [internal]
+
+  caddy:
+    image: caddy:2
+    ports:
+      - "80:80"
+      - "443:443"
+    volumes:
+      - ./Caddyfile:/etc/caddy/Caddyfile:ro
+      - caddy_data:/data
+      - caddy_config:/config
+    restart: unless-stopped
+    depends_on: [numa-relay]
+    networks: [internal]
+
+networks:
+  internal:
+
+volumes:
+  caddy_data:
+  caddy_config:

scripts/generate-blog-index.sh

@@ -0,0 +1,239 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Generate site/blog/index.html from blog/*.md frontmatter.
+# Reads title, description, date from YAML frontmatter in each post.
+# Sorts newest first (by date string — "April 2026" > "March 2026").
+
+OUT="site/blog/index.html"
+
+# Extract frontmatter fields from a markdown file
+extract() {
+  local file="$1" field="$2"
+  sed -n '/^---$/,/^---$/p' "$file" | grep "^${field}:" | sed "s/^${field}: *//"
+}
+
+# Collect posts: "date|name|title|description" per line
+posts=""
+sources="blog/*.md"
+if [ "${BLOG_INCLUDE_DRAFTS:-}" = "1" ] && ls drafts/*.md >/dev/null 2>&1; then
+  sources="blog/*.md drafts/*.md"
+fi
+for f in $sources; do
+  name=$(basename "$f" .md)
+  title=$(extract "$f" title)
+  desc=$(extract "$f" description)
+  date=$(extract "$f" date)
+  posts+="${date}|${name}|${title}|${desc}"$'\n'
+done
+
+# Sort by ISO date (YYYY-MM-DD), newest first
+posts=$(echo "$posts" | grep -v '^$' | sort -t'|' -k1 -r)
+
+# Format ISO date (YYYY-MM-DD) to "Month YYYY"
+format_date() {
+  local months=(January February March April May June July August September October November December)
+  local y="${1%%-*}"
+  local m="${1#*-}"; m="${m%%-*}"; m=$((10#$m))
+  echo "${months[$((m-1))]} $y"
+}
+
+# Generate post list items
+items=""
+while IFS='|' read -r date name title desc; do
+  display_date=$(format_date "$date")
+  items+="    <li>
+      <a href=\"/blog/posts/${name}.html\">
+        <div class=\"post-title\">${title}</div>
+        <div class=\"post-desc\">${desc}</div>
+        <div class=\"post-date\">${display_date}</div>
+      </a>
+    </li>
+"
+done <<< "$posts"
+
+# Write the full index.html — style matches the existing hand-maintained version
+cat > "$OUT" << HTMLEOF
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<title>Blog — Numa</title>
+<meta name="description" content="Technical writing about DNS, Rust, and building infrastructure from scratch.">
+<link rel="stylesheet" href="/fonts/fonts.css">
+<style>
+*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
+
+:root {
+  --bg-deep: #f5f0e8;
+  --bg-surface: #ece5da;
+  --bg-card: #faf7f2;
+  --amber: #c0623a;
+  --amber-dim: #9e4e2d;
+  --teal: #6b7c4e;
+  --text-primary: #2c2418;
+  --text-secondary: #6b5e4f;
+  --text-dim: #a39888;
+  --border: rgba(0, 0, 0, 0.08);
+  --font-display: 'Instrument Serif', Georgia, serif;
+  --font-body: 'DM Sans', system-ui, sans-serif;
+  --font-mono: 'JetBrains Mono', monospace;
+}
+
+body {
+  background: var(--bg-deep);
+  color: var(--text-primary);
+  font-family: var(--font-body);
+  font-weight: 400;
+  line-height: 1.7;
+  -webkit-font-smoothing: antialiased;
+}
+
+body::before {
+  content: '';
+  position: fixed;
+  inset: 0;
+  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.025'/%3E%3C/svg%3E");
+  pointer-events: none;
+  z-index: 9999;
+}
+
+.blog-nav {
+  padding: 1.5rem 2rem;
+  display: flex;
+  align-items: center;
+  gap: 1.5rem;
+}
+
+.blog-nav a {
+  font-family: var(--font-mono);
+  font-size: 0.75rem;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--text-dim);
+  text-decoration: none;
+  transition: color 0.2s;
+}
+.blog-nav a:hover { color: var(--amber); }
+
+.blog-nav .wordmark {
+  font-family: var(--font-display);
+  font-size: 1.4rem;
+  font-weight: 400;
+  color: var(--text-primary);
+  text-decoration: none;
+  text-transform: none;
+  letter-spacing: -0.02em;
+}
+.blog-nav .wordmark:hover { color: var(--amber); }
+
+.blog-nav .sep {
+  color: var(--text-dim);
+  font-family: var(--font-mono);
+  font-size: 0.75rem;
+}
+
+.blog-index {
+  max-width: 720px;
+  margin: 0 auto;
+  padding: 3rem 2rem 6rem;
+}
+
+.blog-index h1 {
+  font-family: var(--font-display);
+  font-weight: 400;
+  font-size: 2.5rem;
+  margin-bottom: 3rem;
+}
+
+.post-list {
+  list-style: none;
+}
+
+.post-list li {
+  padding: 1.5rem 0;
+  border-bottom: 1px solid var(--border);
+}
+
+.post-list li:first-child {
+  border-top: 1px solid var(--border);
+}
+
+.post-list a {
+  text-decoration: none;
+  display: block;
+}
+
+.post-list .post-title {
+  font-family: var(--font-display);
+  font-size: 1.4rem;
+  font-weight: 600;
+  color: var(--text-primary);
+  line-height: 1.3;
+  margin-bottom: 0.4rem;
+  transition: color 0.2s;
+}
+
+.post-list a:hover .post-title {
+  color: var(--amber);
+}
+
+.post-list .post-desc {
+  font-size: 0.95rem;
+  color: var(--text-secondary);
+  line-height: 1.5;
+  margin-bottom: 0.4rem;
+}
+
+.post-list .post-date {
+  font-family: var(--font-mono);
+  font-size: 0.72rem;
+  color: var(--text-dim);
+  letter-spacing: 0.04em;
+}
+
+.blog-footer {
+  text-align: center;
+  padding: 3rem 2rem;
+  border-top: 1px solid var(--border);
+  max-width: 720px;
+  margin: 0 auto;
+}
+
+.blog-footer a {
+  font-family: var(--font-mono);
+  font-size: 0.75rem;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--text-dim);
+  text-decoration: none;
+  margin: 0 1rem;
+}
+.blog-footer a:hover { color: var(--amber); }
+</style>
+</head>
+<body>
+
+<nav class="blog-nav">
+  <a href="/" class="wordmark">Numa</a>
+  <span class="sep">/</span>
+  <a href="/blog/">Blog</a>
+</nav>
+
+<main class="blog-index">
+  <h1>Blog</h1>
+  <ul class="post-list">
+${items}  </ul>
+</main>
+
+<footer class="blog-footer">
+  <a href="https://github.com/razvandimescu/numa">GitHub</a>
+  <a href="/">Home</a>
+</footer>
+
+</body>
+</html>
+HTMLEOF
+
+echo "  blog/index.html generated ($(echo "$posts" | wc -l | tr -d ' ') posts)"

scripts/record-demo.sh

@@ -7,18 +7,19 @@
 # The script:
 #   1. Opens the dashboard in Chrome --app mode (clean, no address bar)
 #   2. Generates DNS traffic (forward, cache hit, blocked)
-#   3. Types "peekm" / "6419" into the Local Services form on camera
-#   4. Shows LAN accessibility badge ("local only" / "LAN")
-#   5. Checks a blocked domain
-#   6. Opens peekm.numa to show the proxy working
-#   7. Records via ffmpeg and converts to optimized GIF
+#   3. Opens Phone Setup QR popover
+#   4. Types "peekm" / "6419" into the Local Services form on camera
+#   5. Shows LAN accessibility badge ("local only" / "LAN")
+#   6. Checks a blocked domain
+#   7. Opens peekm.numa to show the proxy working
+#   8. Records via ffmpeg and converts to optimized GIF
 
 set -euo pipefail
 
 # --------------- Configuration ---------------
 OUTPUT="${1:-assets/hero-demo.gif}"
 PORT=5380
-RECORD_SECONDS=20
+RECORD_SECONDS=24
 VIEWPORT_W=1800
 VIEWPORT_H=1100
 FPS=12
@@ -230,8 +231,16 @@ dig @127.0.0.1 github.com +short > /dev/null 2>&1
 dig @127.0.0.1 ad.doubleclick.net +short > /dev/null 2>&1
 sleep 3
 
-# --------------- Scene 2: Add peekm service via UI (3-7s) ---------------
-log "Scene 2: Adding peekm.numa service..."
+# --------------- Scene 2: Phone Setup popover (3-7s) ---------------
+log "Scene 2: Phone Setup QR popover..."
+run_js "document.querySelector('#phoneSetup button').click();"
+sleep 3
+# Dismiss popover
+run_js "document.getElementById('phoneSetupPopover').style.display = 'none';"
+sleep 1
+
+# --------------- Scene 3: Add peekm service via UI (7-11s) ---------------
+log "Scene 3: Adding peekm.numa service..."
 
 # Services panel is now first — scroll to it
 run_js "
@@ -249,18 +258,18 @@ sleep 0.3
 run_js "document.querySelector('#serviceForm .btn-add').click();"
 sleep 2
 
-# --------------- Scene 3: Open peekm.numa (7-11s) ---------------
-log "Scene 3: Opening peekm.numa in browser..."
+# --------------- Scene 4: Open peekm.numa (11-15s) ---------------
+log "Scene 4: Opening peekm.numa in browser..."
 open "http://peekm.numa/view/peekm/README.md" 2>/dev/null || true
 sleep 4
 
-# --------------- Scene 4: Back to dashboard (11-14s) ---------------
-log "Scene 4: Back to dashboard — LAN badges + LOCAL queries visible..."
+# --------------- Scene 5: Back to dashboard (15-18s) ---------------
+log "Scene 5: Back to dashboard — LAN badges + LOCAL queries visible..."
 osascript -e "tell application \"System Events\" to set frontmost of (first process whose unix id is $CHROME_PID) to true" 2>/dev/null || true
 sleep 3
 
-# --------------- Scene 5: Check Domain blocker (14-17s) ---------------
-log "Scene 5: Check Domain — blocked tracker..."
+# --------------- Scene 6: Check Domain blocker (18-21s) ---------------
+log "Scene 6: Check Domain — blocked tracker..."
 # Scroll down to blocking panel
 run_js "
     var blockPanel = document.getElementById('blockingPanel');
@@ -273,8 +282,8 @@ sleep 0.3
 run_js "document.querySelector('#checkDomainInput').closest('form').querySelector('.btn').click();"
 sleep 2
 
-# --------------- Scene 6: Terminal-style dig overlay (17-20s) ---------------
-log "Scene 6: dig proof overlay..."
+# --------------- Scene 7: Terminal-style dig overlay (21-24s) ---------------
+log "Scene 7: dig proof overlay..."
 DIG_RESULT=$(dig @127.0.0.1 peekm.numa +short 2>/dev/null | head -1)
 run_js "
     var overlay = document.createElement('div');

scripts/release.sh

@@ -37,7 +37,7 @@ cargo update --workspace
 git add Cargo.toml Cargo.lock
 git commit -m "chore: bump version to $VERSION"
 git tag "$TAG"
-git push origin main --tags
+git push origin main "$TAG"
 
 echo
 echo "Released $TAG — GitHub Actions will build, publish to crates.io, and create the release."

scripts/serve-site.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+PORT="${1:-9000}"
+
+if [[ "${1:-}" == "--drafts" ]] || [[ "${2:-}" == "--drafts" ]]; then
+  PORT="${PORT//--drafts/9000}"  # default port if --drafts was first arg
+  make blog-drafts
+else
+  make blog
+fi
+
+echo "Serving site at http://localhost:$PORT"
+cd site && python3 -m http.server "$PORT"

site/blog-template.html

@@ -74,6 +74,7 @@ body::before {
   font-weight: 400;
   color: var(--text-primary);
   text-decoration: none;
+  text-transform: none;
   letter-spacing: -0.02em;
 }
 .blog-nav .wordmark:hover { color: var(--amber); }
@@ -266,9 +267,105 @@ body::before {
 .blog-footer a:hover { color: var(--amber); }
 
 /* --- Responsive --- */
+/* Hero metrics cards */
+.hero-metrics {
+  display: grid;
+  grid-template-columns: repeat(3, 1fr);
+  gap: 1rem;
+  margin: 2rem 0;
+}
+.metric-card {
+  background: var(--bg-card);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 1.25rem;
+  text-align: center;
+}
+.metric-vs {
+  font-family: var(--font-mono);
+  font-size: 0.7rem;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--text-dim);
+  margin-bottom: 0.5rem;
+}
+.metric-value {
+  font-family: var(--font-display);
+  font-size: 2.4rem;
+  font-weight: 400;
+  color: var(--amber);
+  line-height: 1.1;
+}
+.metric-label {
+  font-size: 0.82rem;
+  color: var(--text-secondary);
+  margin-top: 0.5rem;
+  line-height: 1.3;
+}
+
+/* Before/after progression */
+.before-after {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  gap: 1.5rem;
+  margin: 2rem 0;
+  padding: 1.5rem;
+  background: var(--bg-card);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+}
+.ba-item { text-align: center; }
+.ba-label {
+  font-family: var(--font-mono);
+  font-size: 0.7rem;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--text-dim);
+  margin-bottom: 0.3rem;
+}
+.ba-value {
+  font-family: var(--font-display);
+  font-size: 1.8rem;
+  font-weight: 400;
+  color: var(--text-secondary);
+}
+.ba-before {
+  text-decoration: line-through;
+  text-decoration-color: rgba(192, 98, 58, 0.4);
+  color: var(--text-dim);
+}
+.ba-after { color: var(--amber); }
+.ba-arrow { font-size: 1.5rem; color: var(--text-dim); }
+.ba-ref {
+  border-left: 1px solid var(--border);
+  padding-left: 1.5rem;
+}
+
+/* Spike highlight */
+.spike {
+  background: rgba(192, 98, 58, 0.12);
+  padding: 0.15em 0.5em;
+  border-radius: 3px;
+  font-weight: 600;
+  color: var(--amber-dim);
+}
+
+/* Section dividers */
+.article hr {
+  border: none;
+  height: 1px;
+  background: var(--border);
+  margin: 3rem auto;
+  max-width: 120px;
+}
+
 @media (max-width: 640px) {
   .article { padding: 2rem 1.25rem 4rem; }
   .article pre { padding: 1rem; margin-left: -0.5rem; margin-right: -0.5rem; border-radius: 0; border-left: none; border-right: none; }
+  .hero-metrics { grid-template-columns: 1fr; }
+  .before-after { flex-direction: column; gap: 0.75rem; }
+  .ba-ref { border-left: none; border-top: 1px solid var(--border); padding-left: 0; padding-top: 0.75rem; }
 }
 </style>
 </head>

site/blog/dot-handshake.svg

@@ -0,0 +1,129 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 720 360" font-family="'DM Sans', system-ui, sans-serif" font-size="12">
+  <defs>
+    <marker id="arr-amber" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="6" markerHeight="6" orient="auto">
+      <path d="M 0 0 L 10 5 L 0 10 z" fill="#c0623a"/>
+    </marker>
+    <marker id="arr-dim" viewBox="0 0 10 10" refX="9" refY="5" markerWidth="6" markerHeight="6" orient="auto">
+      <path d="M 0 0 L 10 5 L 0 10 z" fill="#a39888"/>
+    </marker>
+    <filter id="shadow" x="-3%" y="-3%" width="106%" height="106%">
+      <feDropShadow dx="0" dy="1" stdDeviation="2" flood-opacity="0.06"/>
+    </filter>
+  </defs>
+
+  <!-- Background -->
+  <rect width="720" height="360" rx="8" fill="#faf7f2"/>
+
+  <!-- Title -->
+  <text x="360" y="32" text-anchor="middle" font-size="15" font-weight="600" fill="#2c2418" font-family="'Instrument Serif', Georgia, serif" letter-spacing="-0.02em">UDP vs DoT — one lookup, three scenarios</text>
+  <text x="360" y="50" text-anchor="middle" font-size="11" fill="#a39888">Time flows downward. Amber = DNS work. Gray = TCP/TLS handshake overhead.</text>
+
+  <!-- ==================== Column 1: Plain UDP ==================== -->
+  <g transform="translate(20, 0)">
+    <!-- Column header -->
+    <text x="90" y="84" text-anchor="middle" font-size="13" font-weight="600" fill="#2c2418">Plain UDP DNS</text>
+    <text x="90" y="101" text-anchor="middle" font-size="10" fill="#a39888" letter-spacing="0.06em">PORT 53 · CLEARTEXT</text>
+
+    <!-- Lane labels -->
+    <text x="25" y="128" font-size="10" fill="#6b5e4f">client</text>
+    <text x="133" y="128" font-size="10" fill="#6b5e4f">server</text>
+
+    <!-- Lanes -->
+    <line x1="35" y1="138" x2="35" y2="198" stroke="#d4cbba" stroke-width="1" stroke-dasharray="2 3"/>
+    <line x1="145" y1="138" x2="145" y2="198" stroke="#d4cbba" stroke-width="1" stroke-dasharray="2 3"/>
+
+    <!-- query -->
+    <line x1="37" y1="148" x2="143" y2="160" stroke="#c0623a" stroke-width="2" marker-end="url(#arr-amber)"/>
+    <text x="90" y="143" text-anchor="middle" font-size="10" fill="#9e4e2d" font-weight="500">query</text>
+
+    <!-- response -->
+    <line x1="143" y1="178" x2="37" y2="190" stroke="#c0623a" stroke-width="2" marker-end="url(#arr-amber)"/>
+    <text x="90" y="205" text-anchor="middle" font-size="10" fill="#9e4e2d" font-weight="500">response</text>
+
+    <!-- Total cost badge -->
+    <rect x="20" y="225" width="140" height="32" rx="4" fill="#faf7f2" stroke="#d4cbba" stroke-width="1" filter="url(#shadow)"/>
+    <text x="90" y="241" text-anchor="middle" font-size="9" fill="#a39888" letter-spacing="0.04em">TOTAL LATENCY</text>
+    <text x="90" y="253" text-anchor="middle" font-size="11" font-weight="600" fill="#c0623a" font-family="'JetBrains Mono', monospace">1 × RTT</text>
+  </g>
+
+  <!-- ==================== Column 2: DoT cold ==================== -->
+  <g transform="translate(270, 0)">
+    <!-- Column header -->
+    <text x="90" y="84" text-anchor="middle" font-size="13" font-weight="600" fill="#2c2418">DoT — first query</text>
+    <text x="90" y="101" text-anchor="middle" font-size="10" fill="#a39888" letter-spacing="0.06em">PORT 853 · NEW CONNECTION</text>
+
+    <!-- Lane labels -->
+    <text x="25" y="128" font-size="10" fill="#6b5e4f">client</text>
+    <text x="133" y="128" font-size="10" fill="#6b5e4f">server</text>
+
+    <!-- Lanes -->
+    <line x1="35" y1="138" x2="35" y2="308" stroke="#d4cbba" stroke-width="1" stroke-dasharray="2 3"/>
+    <line x1="145" y1="138" x2="145" y2="308" stroke="#d4cbba" stroke-width="1" stroke-dasharray="2 3"/>
+
+    <!-- === RTT 1: TCP handshake === -->
+    <!-- SYN -->
+    <line x1="37" y1="145" x2="143" y2="153" stroke="#a39888" stroke-width="1.5" marker-end="url(#arr-dim)"/>
+    <!-- SYN-ACK -->
+    <line x1="143" y1="163" x2="37" y2="171" stroke="#a39888" stroke-width="1.5" marker-end="url(#arr-dim)"/>
+    <!-- ACK -->
+    <line x1="37" y1="181" x2="143" y2="189" stroke="#a39888" stroke-width="1.5" marker-end="url(#arr-dim)"/>
+    <!-- Label + RTT marker -->
+    <text x="168" y="170" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">1 rtt</text>
+    <text x="90" y="143" text-anchor="middle" font-size="9" fill="#6b5e4f" font-style="italic">TCP handshake</text>
+
+    <!-- === RTT 2: TLS 1.3 handshake === -->
+    <!-- ClientHello -->
+    <line x1="37" y1="208" x2="143" y2="216" stroke="#a39888" stroke-width="1.5" marker-end="url(#arr-dim)"/>
+    <!-- ServerHello + Cert + Finished -->
+    <line x1="143" y1="226" x2="37" y2="234" stroke="#a39888" stroke-width="1.5" marker-end="url(#arr-dim)"/>
+    <!-- Label + RTT marker -->
+    <text x="168" y="222" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">2 rtt</text>
+    <text x="90" y="205" text-anchor="middle" font-size="9" fill="#6b5e4f" font-style="italic">TLS 1.3 handshake</text>
+
+    <!-- === RTT 3: DNS exchange === -->
+    <!-- query (piggybacked on ClientFinished) -->
+    <line x1="37" y1="253" x2="143" y2="261" stroke="#c0623a" stroke-width="2" marker-end="url(#arr-amber)"/>
+    <!-- response -->
+    <line x1="143" y1="271" x2="37" y2="279" stroke="#c0623a" stroke-width="2" marker-end="url(#arr-amber)"/>
+    <!-- Label + RTT marker -->
+    <text x="168" y="267" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">3 rtt</text>
+    <text x="90" y="250" text-anchor="middle" font-size="10" fill="#9e4e2d" font-weight="500">query + response</text>
+
+    <!-- Total cost badge -->
+    <rect x="20" y="295" width="140" height="32" rx="4" fill="#faf7f2" stroke="#d4cbba" stroke-width="1" filter="url(#shadow)"/>
+    <text x="90" y="311" text-anchor="middle" font-size="9" fill="#a39888" letter-spacing="0.04em">TOTAL LATENCY</text>
+    <text x="90" y="323" text-anchor="middle" font-size="11" font-weight="600" fill="#c0623a" font-family="'JetBrains Mono', monospace">3 × RTT</text>
+  </g>
+
+  <!-- ==================== Column 3: DoT reused ==================== -->
+  <g transform="translate(520, 0)">
+    <!-- Column header -->
+    <text x="90" y="84" text-anchor="middle" font-size="13" font-weight="600" fill="#2c2418">DoT — reused session</text>
+    <text x="90" y="101" text-anchor="middle" font-size="10" fill="#a39888" letter-spacing="0.06em">PORT 853 · PERSISTENT TCP/TLS</text>
+
+    <!-- Lane labels -->
+    <text x="25" y="128" font-size="10" fill="#6b5e4f">client</text>
+    <text x="133" y="128" font-size="10" fill="#6b5e4f">server</text>
+
+    <!-- Lanes -->
+    <line x1="35" y1="138" x2="35" y2="198" stroke="#d4cbba" stroke-width="1" stroke-dasharray="2 3"/>
+    <line x1="145" y1="138" x2="145" y2="198" stroke="#d4cbba" stroke-width="1" stroke-dasharray="2 3"/>
+
+    <!-- query -->
+    <line x1="37" y1="148" x2="143" y2="160" stroke="#c0623a" stroke-width="2" marker-end="url(#arr-amber)"/>
+    <text x="90" y="143" text-anchor="middle" font-size="10" fill="#9e4e2d" font-weight="500">query</text>
+
+    <!-- response -->
+    <line x1="143" y1="178" x2="37" y2="190" stroke="#c0623a" stroke-width="2" marker-end="url(#arr-amber)"/>
+    <text x="90" y="205" text-anchor="middle" font-size="10" fill="#9e4e2d" font-weight="500">response</text>
+
+    <!-- Total cost badge -->
+    <rect x="20" y="225" width="140" height="32" rx="4" fill="#faf7f2" stroke="#d4cbba" stroke-width="1" filter="url(#shadow)"/>
+    <text x="90" y="241" text-anchor="middle" font-size="9" fill="#a39888" letter-spacing="0.04em">TOTAL LATENCY</text>
+    <text x="90" y="253" text-anchor="middle" font-size="11" font-weight="600" fill="#c0623a" font-family="'JetBrains Mono', monospace">1 × RTT</text>
+
+    <!-- Tiny caption -->
+    <text x="90" y="280" text-anchor="middle" font-size="9" fill="#a39888" font-style="italic">(handshake amortized</text>
+    <text x="90" y="292" text-anchor="middle" font-size="9" fill="#a39888" font-style="italic">across the session)</text>
+  </g>
+</svg>

site/blog/hostile-network.svg

@@ -0,0 +1,92 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 720 330" font-family="'DM Sans', system-ui, sans-serif" font-size="12">
+  <defs>
+    <filter id="shadow" x="-3%" y="-3%" width="106%" height="106%">
+      <feDropShadow dx="0" dy="1" stdDeviation="2" flood-opacity="0.06"/>
+    </filter>
+    <!-- Diagonal hatch for "wasted" UDP timeout regions. Darker warm gray
+         base + slightly darker diagonal stripes at 45°. The stripe pattern
+         is the Gantt convention for "dead/blocked time" — it reads as
+         "this time was thrown away" without needing the legend. -->
+    <pattern id="wasted-hatch" patternUnits="userSpaceOnUse" width="7" height="7" patternTransform="rotate(-45)">
+      <rect width="7" height="7" fill="#8b7f6f"/>
+      <line x1="0" y1="0" x2="0" y2="7" stroke="#3d3427" stroke-width="1.6" opacity="0.38"/>
+    </pattern>
+  </defs>
+
+  <!-- Background -->
+  <rect width="720" height="330" rx="8" fill="#faf7f2"/>
+
+  <!-- Title -->
+  <text x="360" y="32" text-anchor="middle" font-size="15" font-weight="600" fill="#2c2418" font-family="'Instrument Serif', Georgia, serif" letter-spacing="-0.02em">TCP fallback with UDP auto-disable</text>
+  <text x="360" y="50" text-anchor="middle" font-size="11" fill="#a39888">Latency profile on an ISP that blocks outbound UDP:53</text>
+
+  <!-- Legend -->
+  <g transform="translate(160, 70)">
+    <rect width="14" height="12" rx="2" fill="url(#wasted-hatch)"/>
+    <text x="22" y="10" font-size="11" fill="#6b5e4f">UDP timeout — 800 ms wasted</text>
+    <rect x="220" width="14" height="12" rx="2" fill="#c0623a"/>
+    <text x="242" y="10" font-size="11" fill="#6b5e4f">TCP — successful exchange</text>
+  </g>
+
+  <!-- Time axis -->
+  <!-- bar area: x=90 to x=570 (480px), representing 0-1200ms, scale 0.4 px/ms -->
+  <line x1="90" y1="108" x2="570" y2="108" stroke="#d4cbba" stroke-width="1"/>
+  <!-- tick marks -->
+  <line x1="90" y1="106" x2="90" y2="112" stroke="#a39888" stroke-width="1"/>
+  <line x1="210" y1="106" x2="210" y2="112" stroke="#a39888" stroke-width="1"/>
+  <line x1="330" y1="106" x2="330" y2="112" stroke="#a39888" stroke-width="1"/>
+  <line x1="410" y1="106" x2="410" y2="112" stroke="#a39888" stroke-width="1"/>
+  <line x1="530" y1="106" x2="530" y2="112" stroke="#a39888" stroke-width="1"/>
+  <!-- tick labels -->
+  <text x="90" y="102" text-anchor="middle" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">0</text>
+  <text x="210" y="102" text-anchor="middle" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">300</text>
+  <text x="330" y="102" text-anchor="middle" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">600</text>
+  <text x="410" y="102" text-anchor="middle" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">800</text>
+  <text x="530" y="102" text-anchor="middle" font-size="9" fill="#a39888" font-family="'JetBrains Mono', monospace">1100 ms</text>
+
+  <!-- ============ Phase 1: UDP-first (wasted 800ms per query) ============ -->
+
+  <!-- Query 1 -->
+  <text x="82" y="135" text-anchor="end" font-size="11" fill="#6b5e4f">query 1</text>
+  <rect x="90" y="125" width="320" height="16" rx="2" fill="url(#wasted-hatch)"/>
+  <rect x="410" y="125" width="120" height="16" rx="2" fill="#c0623a"/>
+  <text x="540" y="137" font-size="10" fill="#6b5e4f" font-family="'JetBrains Mono', monospace">1,100 ms</text>
+
+  <!-- Query 2 -->
+  <text x="82" y="159" text-anchor="end" font-size="11" fill="#6b5e4f">query 2</text>
+  <rect x="90" y="149" width="320" height="16" rx="2" fill="url(#wasted-hatch)"/>
+  <rect x="410" y="149" width="120" height="16" rx="2" fill="#c0623a"/>
+  <text x="540" y="161" font-size="10" fill="#6b5e4f" font-family="'JetBrains Mono', monospace">1,100 ms</text>
+
+  <!-- Query 3 -->
+  <text x="82" y="183" text-anchor="end" font-size="11" fill="#6b5e4f">query 3</text>
+  <rect x="90" y="173" width="320" height="16" rx="2" fill="url(#wasted-hatch)"/>
+  <rect x="410" y="173" width="120" height="16" rx="2" fill="#c0623a"/>
+  <text x="540" y="185" font-size="10" fill="#6b5e4f" font-family="'JetBrains Mono', monospace">1,100 ms</text>
+
+  <!-- State-change divider -->
+  <line x1="90" y1="206" x2="570" y2="206" stroke="#6b7c4e" stroke-width="1" stroke-dasharray="4 3"/>
+  <rect x="200" y="198" width="260" height="18" rx="9" fill="#faf7f2" stroke="#6b7c4e" stroke-width="1" filter="url(#shadow)"/>
+  <text x="330" y="210" text-anchor="middle" font-size="10" fill="#566540" font-weight="500">3 consecutive failures → UDP auto-disabled</text>
+
+  <!-- ============ Phase 2: TCP-first (UDP skipped) ============ -->
+
+  <!-- Query 4 -->
+  <text x="82" y="235" text-anchor="end" font-size="11" fill="#6b5e4f">query 4</text>
+  <rect x="90" y="225" width="120" height="16" rx="2" fill="#c0623a"/>
+  <text x="220" y="237" font-size="10" fill="#6b5e4f" font-family="'JetBrains Mono', monospace">300 ms</text>
+
+  <!-- Query 5 -->
+  <text x="82" y="259" text-anchor="end" font-size="11" fill="#6b5e4f">query 5</text>
+  <rect x="90" y="249" width="120" height="16" rx="2" fill="#c0623a"/>
+  <text x="220" y="261" font-size="10" fill="#6b5e4f" font-family="'JetBrains Mono', monospace">300 ms</text>
+
+  <!-- Speedup callout -->
+  <g transform="translate(300, 246)">
+    <line x1="0" y1="-10" x2="0" y2="22" stroke="#6b7c4e" stroke-width="1" stroke-dasharray="2 2"/>
+    <text x="10" y="6" font-size="10" fill="#566540" font-style="italic">3.7× faster — no more UDP wait</text>
+  </g>
+
+  <!-- Footer caption -->
+  <text x="360" y="298" text-anchor="middle" font-size="10" fill="#a39888" font-style="italic">The flag resets on network change (LAN IP delta). Switch back to a clean network and UDP is tried again.</text>
+</svg>

site/blog/index.html

@@ -67,6 +67,7 @@ body::before {
   font-weight: 400;
   color: var(--text-primary);
   text-decoration: none;
+  text-transform: none;
   letter-spacing: -0.02em;
 }
 .blog-nav .wordmark:hover { color: var(--amber); }
@@ -167,6 +168,20 @@ body::before {
 <main class="blog-index">
   <h1>Blog</h1>
   <ul class="post-list">
+    <li>
+      <a href="/blog/posts/fixing-doh-tail-latency.html">
+        <div class="post-title">Fixing DNS tail latency with a 5-line config and a 50-line function</div>
+        <div class="post-desc">Periodic 40-140ms DoH spikes from hyper's dispatch channel. The fix was reqwest window tuning and request hedging — Dean & Barroso's "The Tail at Scale," applied to a DNS forwarder. Same ideas took cold recursive p99 from 2.3 seconds to 538ms.</div>
+        <div class="post-date">April 2026</div>
+      </a>
+    </li>
+    <li>
+      <a href="/blog/posts/dot-from-scratch.html">
+        <div class="post-title">DNS-over-TLS from Scratch in Rust</div>
+        <div class="post-desc">Building RFC 7858 on top of rustls — length-prefix framing, ALPN cross-protocol defense, and two bugs that only the strict clients caught.</div>
+        <div class="post-date">April 2026</div>
+      </a>
+    </li>
     <li>
       <a href="/blog/posts/dnssec-from-scratch.html">
         <div class="post-title">Implementing DNSSEC from Scratch in Rust</div>
@@ -177,7 +192,7 @@ body::before {
     <li>
       <a href="/blog/posts/dns-from-scratch.html">
         <div class="post-title">I Built a DNS Resolver from Scratch in Rust</div>
-        <div class="post-desc">How DNS actually works at the wire level — label compression, TTL tricks, DoH implementation, and what I learned building a resolver with zero DNS libraries.</div>
+        <div class="post-desc">How DNS actually works at the wire level — label compression, TTL tricks, DoH, and what surprised me building a resolver with zero DNS libraries.</div>
         <div class="post-date">March 2026</div>
       </a>
     </li>

site/dashboard.html

@@ -217,12 +217,18 @@ body {
   min-width: 2px;
 }
 .path-bar-fill.forward { background: var(--amber); }
+.path-bar-fill.upstream { background: var(--amber-dim); }
 .path-bar-fill.recursive { background: var(--cyan); }
 .path-bar-fill.cached { background: var(--teal); }
 .path-bar-fill.local { background: var(--violet); }
 .path-bar-fill.override { background: var(--emerald); }
 .path-bar-fill.error { background: var(--rose); }
 .path-bar-fill.blocked { background: var(--text-dim); }
+.path-bar-fill.udp { background: var(--text-dim); }
+.path-bar-fill.tcp { background: var(--violet); }
+.path-bar-fill.dot { background: var(--emerald); }
+.path-bar-fill.doh { background: var(--teal); }
+.path-bar-fill.odoh { background: var(--violet-dim); }
 .path-pct {
   font-family: var(--font-mono);
   font-size: 0.75rem;
@@ -281,6 +287,7 @@ body {
   font-weight: 500;
 }
 .path-tag.FORWARD { background: rgba(192, 98, 58, 0.12); color: var(--amber-dim); }
+.path-tag.UPSTREAM { background: rgba(160, 120, 72, 0.12); color: var(--amber-dim); }
 .path-tag.RECURSIVE { background: rgba(74, 124, 138, 0.12); color: var(--cyan); }
 .path-tag.CACHED { background: rgba(107, 124, 78, 0.12); color: var(--teal-dim); }
 .path-tag.LOCAL { background: rgba(100, 116, 139, 0.12); color: var(--violet-dim); }
@@ -288,6 +295,11 @@ body {
 .path-tag.SERVFAIL { background: rgba(181, 68, 58, 0.12); color: var(--rose); }
 .path-tag.BLOCKED { background: rgba(163, 152, 136, 0.15); color: var(--text-dim); }
 .path-tag.COALESCED { background: rgba(138, 104, 158, 0.12); color: var(--violet-dim); }
+.path-tag.UDP { background: rgba(163, 152, 136, 0.15); color: var(--text-dim); }
+.path-tag.TCP { background: rgba(100, 116, 139, 0.12); color: var(--violet-dim); }
+.path-tag.DOT { background: rgba(82, 122, 82, 0.12); color: var(--emerald); }
+.path-tag.DOH { background: rgba(107, 124, 78, 0.12); color: var(--teal); }
+.src-tag { font-size: 0.6rem; color: var(--text-dim); letter-spacing: 0.02em; }
 
 /* Sidebar panels */
 .sidebar {
@@ -541,7 +553,11 @@ body {
 @media (max-width: 700px) {
   .stats-row { grid-template-columns: repeat(2, 1fr); }
   .dashboard { padding: 1rem; }
-  .header { padding: 1rem; }
+  .header { padding: 0.8rem 1rem; }
+  .logo { font-size: 1.4rem; }
+  .tagline { display: none; }
+  #headerVersion { display: none; }
+  #phoneSetup { display: none; }
 }
 </style>
 </head>
@@ -550,9 +566,24 @@ body {
 <div class="header">
   <div class="header-left">
     <div class="logo">Numa</div>
+    <span id="headerVersion" style="font-family:var(--font-mono);font-size:0.68rem;color:var(--text-dim);"></span>
     <div class="tagline">DNS that governs itself</div>
   </div>
   <div style="display:flex;align-items:center;gap:1.2rem;">
+    <div id="phoneSetup" style="position:relative;display:none;">
+      <button class="btn" onclick="togglePhoneSetup()" style="background:var(--bg-surface);color:var(--text-secondary);font-family:var(--font-mono);font-size:0.7rem;padding:0.35rem 0.6rem;border:1px solid var(--border);" title="Set up phone">Phone Setup</button>
+      <div id="phoneSetupPopover" style="display:none;position:absolute;top:calc(100% + 8px);right:0;z-index:100;background:var(--bg-card);border:1px solid var(--border);border-radius:10px;padding:1.2rem;width:260px;box-shadow:0 4px 20px rgba(0,0,0,0.08);">
+        <div style="font-size:0.7rem;font-weight:600;text-transform:uppercase;letter-spacing:0.1em;color:var(--text-secondary);margin-bottom:0.8rem;">Phone Setup</div>
+        <div id="qrContainer" style="display:flex;justify-content:center;margin-bottom:0.8rem;"></div>
+        <div id="phoneSetupLink" style="display:none;text-align:center;margin-bottom:0.8rem;"></div>
+        <div style="font-family:var(--font-mono);font-size:0.62rem;color:var(--text-dim);line-height:1.6;">
+          1. Scan QR &rarr; allow download<br>
+          2. Settings &rarr; Profile Downloaded &rarr; Install<br>
+          3. Settings &rarr; General &rarr; About &rarr;<br>
+          &nbsp;&nbsp;&nbsp;Certificate Trust Settings &rarr; toggle ON
+        </div>
+      </div>
+    </div>
     <button class="btn" id="pauseBtn" style="background:var(--amber);color:white;font-family:var(--font-mono);font-size:0.7rem;display:none;">Pause 5m</button>
     <button class="btn" id="toggleBtn" onclick="toggleBlocking()" style="background:var(--rose);color:white;font-family:var(--font-mono);font-size:0.7rem;display:none;"></button>
     <div class="status-badge">
@@ -607,6 +638,26 @@ body {
     </div>
   </div>
 
+  <!-- Inbound wire (apps → numa) -->
+  <div class="panel">
+    <div class="panel-header">
+      <span class="panel-title">Inbound Wire <span style="color: var(--text-dim); font-weight: normal;">apps → numa</span></span>
+      <span class="panel-title" id="transportEncrypted" style="color: var(--text-dim)"></span>
+    </div>
+    <div class="panel-body" id="transportBars">
+    </div>
+  </div>
+
+  <!-- Outbound wire (numa → internet) -->
+  <div class="panel">
+    <div class="panel-header">
+      <span class="panel-title">Outbound Wire <span style="color: var(--text-dim); font-weight: normal;">numa → internet</span></span>
+      <span class="panel-title" id="upstreamWireEncrypted" style="color: var(--text-dim)"></span>
+    </div>
+    <div class="panel-body" id="upstreamWireBars">
+    </div>
+  </div>
+
   <!-- Main grid: query log + sidebar -->
   <div class="main-grid">
     <!-- Query log -->
@@ -622,12 +673,21 @@ body {
             <option value="RECURSIVE">recursive</option>
             <option value="COALESCED">coalesced</option>
             <option value="FORWARD">forward</option>
+            <option value="UPSTREAM">upstream</option>
             <option value="CACHED">cached</option>
             <option value="BLOCKED">blocked</option>
             <option value="OVERRIDE">override</option>
             <option value="LOCAL">local</option>
             <option value="SERVFAIL">error</option>
           </select>
+          <select id="logFilterTransport" onchange="applyLogFilter()"
+            style="font-family:var(--font-mono);font-size:0.7rem;padding:0.25rem 0.4rem;border:1px solid var(--border);border-radius:4px;background:var(--bg-surface);color:var(--text-secondary);outline:none;">
+            <option value="">all transports</option>
+            <option value="UDP">UDP</option>
+            <option value="TCP">TCP</option>
+            <option value="DOT">DoT</option>
+            <option value="DOH">DoH</option>
+          </select>
           <span class="panel-title" id="queryCount" style="color: var(--text-dim)"></span>
         </div>
       </div>
@@ -639,6 +699,7 @@ body {
               <th>Type</th>
               <th>Domain</th>
               <th>Path</th>
+              <th>Transport</th>
               <th>Result</th>
               <th>Latency</th>
             </tr>
@@ -787,6 +848,41 @@ function formatTime(epoch) {
   return d.toLocaleTimeString([], { hour12: false });
 }
 
+let mobilePort = 8765;
+function togglePhoneSetup() {
+  const pop = document.getElementById('phoneSetupPopover');
+  const isOpen = pop.style.display !== 'none';
+  pop.style.display = isOpen ? 'none' : 'block';
+  if (!isOpen) {
+    if (window.innerWidth <= 700) {
+      document.getElementById('qrContainer').style.display = 'none';
+      const linkEl = document.getElementById('phoneSetupLink');
+      const host = window.location.hostname;
+      linkEl.style.display = 'block';
+      linkEl.innerHTML = `<a href="http://${host}:${mobilePort}/mobileconfig" style="display:inline-block;padding:0.5rem 1rem;background:var(--amber);color:white;border-radius:6px;text-decoration:none;font-family:var(--font-mono);font-size:0.75rem;">Install Profile</a>`;
+    } else {
+      fetch(API + '/qr').then(r => r.text()).then(svg => {
+        document.getElementById('qrContainer').innerHTML = svg;
+      }).catch(() => {
+        document.getElementById('qrContainer').innerHTML = '<div class="empty-state">Could not load QR</div>';
+      });
+    }
+  }
+}
+document.addEventListener('click', (e) => {
+  const setup = document.getElementById('phoneSetup');
+  if (setup && !setup.contains(e.target)) {
+    document.getElementById('phoneSetupPopover').style.display = 'none';
+  }
+});
+
+function shortSrc(addr) {
+  if (!addr) return '';
+  const ip = addr.replace(/:\d+$/, '');
+  if (ip === '127.0.0.1' || ip === '::1') return 'localhost';
+  return ip;
+}
+
 function formatRemaining(secs) {
   if (secs == null) return 'permanent';
   if (secs < 60) return `${secs}s left`;
@@ -857,8 +953,34 @@ function renderMemory(mem, stats) {
   `;
 }
 
+function renderBarChart(containerId, defs, data, total) {
+  total = total || 1;
+  document.getElementById(containerId).innerHTML = defs
+    .filter(d => (data[d.key] || 0) > 0)
+    .map(d => {
+      const count = data[d.key] || 0;
+      const pct = ((count / total) * 100).toFixed(1);
+      return `
+      <div class="path-bar-row">
+        <span class="path-label">${d.label}</span>
+        <div class="path-bar-track">
+          <div class="path-bar-fill ${d.cls}" style="width: ${pct}%"></div>
+        </div>
+        <span class="path-pct">${pct}%</span>
+      </div>`;
+    }).join('');
+}
+
+function encryptionPct(data, encryptedKeys, allKeys) {
+  const total = allKeys.reduce((s, k) => s + (data[k] || 0), 0);
+  if (total === 0) return 0;
+  const encrypted = encryptedKeys.reduce((s, k) => s + (data[k] || 0), 0);
+  return Math.round((encrypted / total) * 100);
+}
+
 const PATH_DEFS = [
   { key: 'forwarded', label: 'Forward', cls: 'forward' },
+  { key: 'upstream',  label: 'Upstream', cls: 'upstream' },
   { key: 'recursive', label: 'Recursive', cls: 'recursive' },
   { key: 'cached',    label: 'Cached',  cls: 'cached' },
   { key: 'local',     label: 'Local',   cls: 'local' },
@@ -868,20 +990,39 @@ const PATH_DEFS = [
 ];
 
 function renderPaths(queries) {
-  const total = queries.total || 1;
-  const container = document.getElementById('pathBars');
-  container.innerHTML = PATH_DEFS.map(p => {
-    const count = queries[p.key] || 0;
-    const pct = ((count / total) * 100).toFixed(1);
-    return `
-      <div class="path-bar-row">
-        <span class="path-label">${p.label}</span>
-        <div class="path-bar-track">
-          <div class="path-bar-fill ${p.cls}" style="width: ${pct}%"></div>
-        </div>
-        <span class="path-pct">${pct}%</span>
-      </div>`;
-  }).join('');
+  renderBarChart('pathBars', PATH_DEFS, queries, queries.total);
+}
+
+const TRANSPORT_DEFS = [
+  { key: 'udp', label: 'UDP',  cls: 'udp' },
+  { key: 'tcp', label: 'TCP',  cls: 'tcp' },
+  { key: 'dot', label: 'DoT',  cls: 'dot' },
+  { key: 'doh', label: 'DoH',  cls: 'doh' },
+];
+
+function renderTransport(transport) {
+  const total = (transport.udp + transport.tcp + transport.dot + transport.doh) || 1;
+  renderBarChart('transportBars', TRANSPORT_DEFS, transport, total);
+  const encPct = encryptionPct(transport, ['dot', 'doh'], ['udp', 'tcp', 'dot', 'doh']);
+  const el = document.getElementById('transportEncrypted');
+  el.textContent = `${encPct}% encrypted inbound`;
+  el.style.color = encPct >= 80 ? 'var(--emerald)' : encPct >= 50 ? 'var(--amber)' : 'var(--rose)';
+}
+
+const UPSTREAM_WIRE_DEFS = [
+  { key: 'udp',  label: 'UDP',  cls: 'udp' },
+  { key: 'doh',  label: 'DoH',  cls: 'doh' },
+  { key: 'dot',  label: 'DoT',  cls: 'dot' },
+  { key: 'odoh', label: 'ODoH', cls: 'odoh' },
+];
+
+function renderUpstreamWire(ut) {
+  const total = (ut.udp + ut.doh + ut.dot + ut.odoh) || 0;
+  renderBarChart('upstreamWireBars', UPSTREAM_WIRE_DEFS, ut, total || 1);
+  const encPct = encryptionPct(ut, ['doh', 'dot', 'odoh'], ['udp', 'doh', 'dot', 'odoh']);
+  const el = document.getElementById('upstreamWireEncrypted');
+  el.textContent = total > 0 ? `${encPct}% encrypted outbound` : '';
+  el.style.color = encPct >= 80 ? 'var(--emerald)' : encPct >= 50 ? 'var(--amber)' : 'var(--rose)';
 }
 
 function renderQueryLog(entries) {
@@ -892,6 +1033,7 @@ function renderQueryLog(entries) {
 function applyLogFilter() {
   const domainFilter = document.getElementById('logFilterDomain').value.trim().toLowerCase();
   const pathFilter = document.getElementById('logFilterPath').value;
+  const transportFilter = document.getElementById('logFilterTransport').value;
 
   let filtered = lastLogEntries;
   if (domainFilter) {
@@ -900,6 +1042,9 @@ function applyLogFilter() {
   if (pathFilter) {
     filtered = filtered.filter(e => e.path === pathFilter);
   }
+  if (transportFilter) {
+    filtered = filtered.filter(e => e.transport === transportFilter);
+  }
 
   const tbody = document.getElementById('queryLogBody');
   document.getElementById('queryCount').textContent =
@@ -912,11 +1057,12 @@ function applyLogFilter() {
       ? ` <button class="btn-delete" onclick="allowDomain('${e.domain}')" title="Allow this domain" style="color:var(--emerald);font-size:0.65rem;">allow</button>`
       : '';
     return `
-    <tr>
-      <td>${formatTime(e.timestamp_epoch)}</td>
+    <tr title="Source: ${e.src || 'unknown'}">
+      <td>${formatTime(e.timestamp_epoch)}<br><span class="src-tag">${shortSrc(e.src)}</span></td>
       <td>${e.query_type}</td>
       <td class="domain-cell" title="${e.domain}">${e.domain}${allowBtn}</td>
       <td><span class="path-tag ${e.path}">${e.path}</span></td>
+      <td><span class="path-tag ${e.transport}">${e.transport}</span></td>
       <td style="white-space:nowrap;"><span style="display:inline-block;width:15px;text-align:center;">${e.dnssec === 'secure' ? '<svg title="DNSSEC verified" width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="var(--emerald)" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round" style="vertical-align:-1px;"><path d="M12 22s8-4 8-10V5l-8-3-8 3v7c0 6 8 10 8 10z"/><path d="m9 12 2 2 4-4"/></svg>' : ''}</span>${e.rescode}</td>
       <td>${e.latency_ms.toFixed(1)}ms</td>
     </tr>`;
@@ -1024,16 +1170,23 @@ async function refresh() {
     document.getElementById('totalQueries').textContent = formatNumber(q.total);
     document.getElementById('uptime').textContent = formatUptime(stats.uptime_secs);
     document.getElementById('uptimeSub').textContent = formatUptimeSub(stats.uptime_secs);
+    document.getElementById('headerVersion').textContent = stats.version ? 'v' + stats.version : '';
     document.getElementById('footerUpstream').textContent = stats.upstream || '';
     document.getElementById('footerConfig').textContent = stats.config_path || '';
     document.getElementById('footerData').textContent = stats.data_dir || '';
-    const modeEl = document.getElementById('footerMode');
-    modeEl.textContent = stats.mode || '—';
-    modeEl.style.color = stats.mode === 'recursive' ? 'var(--emerald)' : 'var(--amber)';
     document.getElementById('footerDnssec').textContent = stats.dnssec ? 'on' : 'off';
     document.getElementById('footerDnssec').style.color = stats.dnssec ? 'var(--emerald)' : 'var(--text-dim)';
     document.getElementById('footerSrtt').textContent = stats.srtt ? 'on' : 'off';
     document.getElementById('footerSrtt').style.color = stats.srtt ? 'var(--emerald)' : 'var(--text-dim)';
+    if (!document.getElementById('footerLogs').textContent) {
+      const isWin = stats.data_dir && stats.data_dir.includes(':\\');
+      const isMac = stats.data_dir && stats.data_dir.includes('/usr/local/');
+      const logsEl = document.getElementById('footerLogs');
+      logsEl.textContent = isWin
+        ? stats.data_dir + '\\numa.log'
+        : isMac ? '/usr/local/var/log/numa.log'
+        : 'journalctl -u numa -f';
+    }
 
     // LAN status indicator
     const lanEl = document.getElementById('lanToggle');
@@ -1050,6 +1203,14 @@ async function refresh() {
       }
     }
 
+    const phoneSetupEl = document.getElementById('phoneSetup');
+    if (stats.mobile && stats.mobile.enabled) {
+      phoneSetupEl.style.display = '';
+      mobilePort = stats.mobile.port;
+    } else {
+      phoneSetupEl.style.display = 'none';
+    }
+
     document.getElementById('overrideCount').textContent = stats.overrides.active;
     document.getElementById('blockedCount').textContent = formatNumber(q.blocked);
     const bl = stats.blocking;
@@ -1083,22 +1244,26 @@ async function refresh() {
 
     // QPS calculation
     const now = Date.now();
+    const encPct = encryptionPct(stats.transport, ['dot', 'doh'], ['udp', 'tcp', 'dot', 'doh']);
     if (prevTotal !== null && prevTime !== null) {
       const dt = (now - prevTime) / 1000;
       const dq = q.total - prevTotal;
       const qps = dt > 0 ? (dq / dt).toFixed(1) : '0.0';
-      document.getElementById('qps').textContent = `~${qps}/s`;
+      const encTag = q.total > 0 ? ` · ${encPct}% enc` : '';
+      document.getElementById('qps').textContent = `~${qps}/s${encTag}`;
     }
     prevTotal = q.total;
     prevTime = now;
 
     // Cache hit rate
-    const answered = q.cached + q.forwarded + q.recursive + q.coalesced + q.local + q.overridden;
+    const answered = q.cached + q.forwarded + q.upstream + q.recursive + q.coalesced + q.local + q.overridden;
     const hitRate = answered > 0 ? ((q.cached / answered) * 100).toFixed(1) : '0.0';
     document.getElementById('cacheRate').textContent = hitRate + '%';
 
     // Panels
     renderPaths(q);
+    renderTransport(stats.transport);
+    renderUpstreamWire(stats.upstream_transport || { udp: 0, doh: 0, dot: 0, odoh: 0 });
     renderQueryLog(logs);
     renderOverrides(overrides);
     renderCache(cache);
@@ -1108,6 +1273,7 @@ async function refresh() {
     renderMemory(stats.memory, stats);
 
   } catch (err) {
+    console.error('[numa dashboard] render failed:', err);
     document.getElementById('statusDot').className = 'status-dot error';
     document.getElementById('statusText').textContent = 'disconnected';
   }
@@ -1222,6 +1388,7 @@ function renderBlockingInfo(info) {
 }
 
 function renderAllowlist(entries) {
+  if (document.activeElement && document.activeElement.id === 'allowDomainInput') return;
   const el = document.getElementById('blockingAllowlist');
   const count = entries.length;
   el.innerHTML = `
@@ -1381,14 +1548,14 @@ refresh();
 setInterval(refresh, 2000);
 </script>
 
-<div style="text-align:center;padding:0.8rem;font-family:var(--font-mono);font-size:0.68rem;color:var(--text-dim);">
+<div style="text-align:center;padding:0.8rem 0.8rem 0.4rem;font-family:var(--font-mono);font-size:0.68rem;color:var(--text-dim);line-height:1.8;">
   Config: <span id="footerConfig" style="user-select:all;color:var(--emerald);"></span>
   · Data: <span id="footerData" style="user-select:all;color:var(--emerald);"></span>
-  · Upstream: <span id="footerUpstream" style="user-select:all;color:var(--emerald);"></span>
-  · Mode: <span id="footerMode" style="color:var(--text-dim);">—</span>
+  · Logs: <span id="footerLogs" style="user-select:all;color:var(--emerald);"></span>
+  <br>
+  Upstream: <span id="footerUpstream" style="user-select:all;color:var(--emerald);"></span>
   · DNSSEC: <span id="footerDnssec" style="color:var(--text-dim);">—</span>
   · SRTT: <span id="footerSrtt" style="color:var(--text-dim);">—</span>
-  · Logs: <span style="user-select:all;color:var(--emerald);">macOS: /usr/local/var/log/numa.log · Linux: journalctl -u numa -f</span>
   · <a href="https://github.com/razvandimescu/numa" target="_blank" rel="noopener" style="color:var(--amber);text-decoration:none;">GitHub</a>
 </div>
 

site/index.html

@@ -188,11 +188,50 @@ p.lead {
   line-height: 1.8;
 }
 
+/* ===========================
+   TOP NAV
+   =========================== */
+.site-nav {
+  padding: 1.5rem 2rem;
+  display: flex;
+  align-items: center;
+  gap: 1.5rem;
+  position: relative;
+  z-index: 10;
+}
+
+.site-nav a {
+  font-family: var(--font-mono);
+  font-size: 0.75rem;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--text-dim);
+  text-decoration: none;
+  transition: color 0.2s ease;
+}
+.site-nav a:hover { color: var(--amber); }
+
+.site-nav .wordmark {
+  font-family: var(--font-display);
+  font-size: 1.4rem;
+  font-weight: 400;
+  color: var(--text-primary);
+  text-transform: none;
+  letter-spacing: -0.02em;
+}
+.site-nav .wordmark:hover { color: var(--amber); }
+
+.site-nav .sep {
+  color: var(--text-dim);
+  font-family: var(--font-mono);
+  font-size: 0.75rem;
+}
+
 /* ===========================
    HERO
    =========================== */
 .hero {
-  min-height: 100vh;
+  min-height: calc(100vh - 5rem);
   display: flex;
   align-items: center;
   position: relative;
@@ -1158,6 +1197,9 @@ footer .closing {
 @media (max-width: 600px) {
   section { padding: 4rem 0; }
   .container { padding: 0 1.25rem; }
+  .site-nav { padding: 1rem 1.25rem; gap: 1rem; }
+  .site-nav .wordmark { font-size: 1.2rem; }
+  .hero { min-height: calc(100vh - 4rem); }
   .network-grid { grid-template-columns: 1fr; }
   .pipeline { flex-direction: column; align-items: stretch; gap: 0; }
   .pipeline-arrow { transform: rotate(90deg); padding: 0.15rem 0; align-self: center; }
@@ -1171,6 +1213,14 @@ footer .closing {
 </head>
 <body>
 
+<nav class="site-nav">
+  <a href="/" class="wordmark">Numa</a>
+  <span class="sep">/</span>
+  <a href="/blog/">Blog</a>
+  <span class="sep">/</span>
+  <a href="https://github.com/razvandimescu/numa" target="_blank" rel="noopener">GitHub</a>
+</nav>
+
 <!-- ==================== HERO ==================== -->
 <section class="hero">
   <div class="roman-bricks" aria-hidden="true"></div>
@@ -1243,6 +1293,8 @@ footer .closing {
           <li>Ad &amp; tracker blocking &mdash; 385K+ domains, zero config</li>
           <li>Recursive resolution &mdash; opt-in, resolve from root nameservers, no upstream needed</li>
           <li>DNSSEC validation &mdash; chain-of-trust + NSEC/NSEC3 denial proofs (RSA, ECDSA, Ed25519)</li>
+          <li>DNS-over-TLS listener &mdash; encrypted DNS for phones and strict clients (RFC 7858 with ALPN defense)</li>
+          <li>Hostile-network resilience &mdash; TCP fallback with UDP auto-disable when ISPs block port 53</li>
           <li>TTL-aware caching (sub-ms lookups)</li>
           <li>Single binary, portable &mdash; macOS, Linux, and Windows</li>
         </ul>
@@ -1261,7 +1313,7 @@ footer .closing {
         </ul>
       </div>
       <div class="layer-card reveal reveal-delay-3">
-        <div class="layer-badge">Coming Next</div>
+        <div class="layer-badge">The Vision</div>
         <h3>Self-Sovereign DNS</h3>
         <ul>
           <li>pkarr integration &mdash; DNS via Mainline DHT, no registrar needed</li>
@@ -1342,6 +1394,14 @@ footer .closing {
             <td class="cross">No</td>
             <td class="check">Root hints + full DNSSEC</td>
           </tr>
+          <tr>
+            <td>DNSSEC validation</td>
+            <td class="muted">Passthrough</td>
+            <td class="muted">Cloud only</td>
+            <td class="muted">Cloud only</td>
+            <td class="muted">Passthrough</td>
+            <td class="check">Full chain-of-trust</td>
+          </tr>
           <tr>
             <td>Ad &amp; tracker blocking</td>
             <td class="check">Yes</td>
@@ -1398,6 +1458,14 @@ footer .closing {
             <td class="cross">No</td>
             <td class="check">Built in (HTTP/2 + rustls)</td>
           </tr>
+          <tr>
+            <td>DNS-over-TLS listener</td>
+            <td class="cross">No</td>
+            <td class="muted">Cloud only</td>
+            <td class="muted">Cloud only</td>
+            <td class="check">Yes (cert required)</td>
+            <td class="check">Self-signed or BYO</td>
+          </tr>
           <tr>
             <td>Conditional forwarding</td>
             <td class="cross">No</td>
@@ -1567,11 +1635,14 @@ footer .closing {
         <dt>Resolution Modes</dt>
         <dd>Recursive (iterative from root hints, CNAME chasing, glue extraction) or Forward (DoH / plain UDP)</dd>
 
+        <dt>Listeners</dt>
+        <dd>UDP:53 + TCP:53 (plain DNS), DoT:853 (RFC 7858 + ALPN), HTTP proxy :80 / HTTPS proxy :443, dashboard :5380</dd>
+
         <dt>DNSSEC</dt>
         <dd>Chain-of-trust via ring &mdash; RSA/SHA-256, ECDSA P-256, Ed25519. NSEC/NSEC3 denial proofs. EDNS0 DO bit, 1232-byte payload (DNS Flag Day 2020).</dd>
 
         <dt>Dependencies</dt>
-        <dd>19 runtime crates &mdash; tokio, axum, hyper, ring (DNSSEC), reqwest (DoH), rcgen + rustls (TLS), socket2 (multicast), serde, and more</dd>
+        <dd>A focused set &mdash; tokio, axum, hyper, ring (DNSSEC), reqwest (DoH), rcgen + rustls + tokio-rustls (TLS/DoT), socket2 (multicast), serde. No transitive DNS library.</dd>
 
         <dt>Packet Format</dt>
         <dd>RFC 1035 compliant. EDNS0 OPT pseudo-record. Parses A, AAAA, NS, CNAME, MX, SOA, SRV, HTTPS, DNSKEY, DS, RRSIG, NSEC, NSEC3.</dd>
@@ -1586,7 +1657,7 @@ footer .closing {
 <span class="prompt">$</span> <span class="cmd">curl</span> <span class="flag">-fsSL</span> https://raw.githubusercontent.com/razvandimescu/numa/main/install.sh <span class="flag">|</span> <span class="cmd">sh</span>
 
 <span class="comment"># Run</span>
-<span class="prompt">$</span> <span class="cmd">sudo numa</span>                          <span class="comment"># bind to :53, :80, :5380</span>
+<span class="prompt">$</span> <span class="cmd">sudo numa</span>                          <span class="comment"># bind :53, :80, :443, :853, :5380</span>
 <span class="prompt">$</span> <span class="cmd">dig</span> <span class="flag">@127.0.0.1</span> google.com         <span class="comment"># test resolution</span>
 <span class="prompt">$</span> <span class="cmd">open</span> http://localhost:5380           <span class="comment"># dashboard</span>
 <span class="prompt">$</span> <span class="cmd">curl</span> <span class="flag">-X POST</span> localhost:5380/services \
@@ -1639,16 +1710,28 @@ footer .closing {
         <span class="phase">Phase 7</span>
         <span class="phase-desc">DNSSEC validation &mdash; chain-of-trust, NSEC/NSEC3 denial proofs, RSA + ECDSA + Ed25519</span>
       </div>
-      <div class="roadmap-item phase-teal">
+      <div class="roadmap-item done">
         <span class="phase">Phase 8</span>
+        <span class="phase-desc">Hostile-network resilience &mdash; TCP fallback with UDP auto-disable when ISPs block :53, RFC 7816 query minimization</span>
+      </div>
+      <div class="roadmap-item done">
+        <span class="phase">Phase 9</span>
+        <span class="phase-desc">Windows support &mdash; cross-platform install/uninstall, <code>netsh</code> DNS config, service integration</span>
+      </div>
+      <div class="roadmap-item done">
+        <span class="phase">Phase 10</span>
+        <span class="phase-desc">DNS-over-TLS listener (RFC 7858) &mdash; ALPN enforcement, persistent connections, self-signed or BYO cert</span>
+      </div>
+      <div class="roadmap-item phase-teal">
+        <span class="phase">Phase 11</span>
         <span class="phase-desc">pkarr integration &mdash; self-sovereign DNS via Mainline DHT, no registrar needed</span>
       </div>
       <div class="roadmap-item phase-teal">
-        <span class="phase">Phase 9</span>
+        <span class="phase">Phase 12</span>
         <span class="phase-desc">Global .numa names &mdash; self-publish, DHT-backed, first-come-first-served</span>
       </div>
       <div class="roadmap-item phase-teal">
-        <span class="phase">Phase 10</span>
+        <span class="phase">Phase 13</span>
         <span class="phase-desc">.onion bridge &mdash; human-readable Tor naming via Ed25519 same-key binding</span>
       </div>
     </div>

src/api.rs

@@ -57,6 +57,7 @@ pub fn router(ctx: Arc<ServerCtx>) -> Router {
         .route("/services/{name}/routes", post(add_route))
         .route("/services/{name}/routes", delete(remove_route))
         .route("/ca.pem", get(serve_ca))
+        .route("/qr", get(serve_qr))
         .route("/fonts/fonts.css", get(serve_fonts_css))
         .route(
             "/fonts/dm-sans-latin.woff2",
@@ -151,6 +152,7 @@ struct QueryLogResponse {
     domain: String,
     query_type: String,
     path: String,
+    transport: String,
     rescode: String,
     latency_ms: f64,
     dnssec: String,
@@ -158,6 +160,7 @@ struct QueryLogResponse {
 
 #[derive(Serialize)]
 struct StatsResponse {
+    version: &'static str,
     uptime_secs: u64,
     upstream: String,
     mode: &'static str, // "recursive" or "forward" — never "auto" at runtime
@@ -166,13 +169,38 @@ struct StatsResponse {
     dnssec: bool,
     srtt: bool,
     queries: QueriesStats,
+    transport: TransportStats,
+    upstream_transport: UpstreamTransportStats,
     cache: CacheStats,
     overrides: OverrideStats,
     blocking: BlockingStatsResponse,
     lan: LanStatsResponse,
+    mobile: MobileStatsResponse,
     memory: MemoryStats,
 }
 
+#[derive(Serialize)]
+struct TransportStats {
+    udp: u64,
+    tcp: u64,
+    dot: u64,
+    doh: u64,
+}
+
+#[derive(Serialize)]
+struct UpstreamTransportStats {
+    udp: u64,
+    doh: u64,
+    dot: u64,
+    odoh: u64,
+}
+
+#[derive(Serialize)]
+struct MobileStatsResponse {
+    enabled: bool,
+    port: u16,
+}
+
 #[derive(Serialize)]
 struct LanStatsResponse {
     enabled: bool,
@@ -183,6 +211,7 @@ struct LanStatsResponse {
 struct QueriesStats {
     total: u64,
     forwarded: u64,
+    upstream: u64,
     recursive: u64,
     coalesced: u64,
     cached: u64,
@@ -403,9 +432,12 @@ async fn diagnose(
     }
 
     // Check upstream (async, no locks held)
-    let upstream = ctx.upstream.lock().unwrap().clone();
-    let (upstream_matched, upstream_detail) =
-        forward_query_for_diagnose(&domain_lower, &upstream, ctx.timeout).await;
+    let upstream = ctx.upstream_pool.lock().unwrap().preferred().cloned();
+    let (upstream_matched, upstream_detail) = if let Some(ref u) = upstream {
+        forward_query_for_diagnose(&domain_lower, u, ctx.timeout).await
+    } else {
+        (false, "no upstream configured".to_string())
+    };
     steps.push(DiagnoseStep {
         source: "upstream".to_string(),
         matched: upstream_matched,
@@ -472,6 +504,7 @@ async fn query_log(
                     domain: e.domain.clone(),
                     query_type: e.query_type.as_str().to_string(),
                     path: e.path.as_str().to_string(),
+                    transport: e.transport.as_str().to_string(),
                     rescode: e.rescode.as_str().to_string(),
                     latency_ms: e.latency_us as f64 / 1000.0,
                     dnssec: e.dnssec.as_str().to_string(),
@@ -512,10 +545,11 @@ async fn stats(State(ctx): State<Arc<ServerCtx>>) -> Json<StatsResponse> {
     let upstream = if ctx.upstream_mode == crate::config::UpstreamMode::Recursive {
         "recursive (root hints)".to_string()
     } else {
-        ctx.upstream.lock().unwrap().to_string()
+        ctx.upstream_pool.lock().unwrap().label()
     };
 
     Json(StatsResponse {
+        version: crate::version(),
         uptime_secs: snap.uptime_secs,
         upstream,
         mode: ctx.upstream_mode.as_str(),
@@ -526,6 +560,7 @@ async fn stats(State(ctx): State<Arc<ServerCtx>>) -> Json<StatsResponse> {
         queries: QueriesStats {
             total: snap.total,
             forwarded: snap.forwarded,
+            upstream: snap.upstream,
             recursive: snap.recursive,
             coalesced: snap.coalesced,
             cached: snap.cached,
@@ -534,6 +569,18 @@ async fn stats(State(ctx): State<Arc<ServerCtx>>) -> Json<StatsResponse> {
             blocked: snap.blocked,
             errors: snap.errors,
         },
+        transport: TransportStats {
+            udp: snap.transport_udp,
+            tcp: snap.transport_tcp,
+            dot: snap.transport_dot,
+            doh: snap.transport_doh,
+        },
+        upstream_transport: UpstreamTransportStats {
+            udp: snap.upstream_transport_udp,
+            doh: snap.upstream_transport_doh,
+            dot: snap.upstream_transport_dot,
+            odoh: snap.upstream_transport_odoh,
+        },
         cache: CacheStats {
             entries: cache_len,
             max_entries: cache_max,
@@ -551,6 +598,10 @@ async fn stats(State(ctx): State<Arc<ServerCtx>>) -> Json<StatsResponse> {
             enabled: ctx.lan_enabled,
             peers: ctx.lan_peers.lock().unwrap().list().len(),
         },
+        mobile: MobileStatsResponse {
+            enabled: ctx.mobile_enabled,
+            port: ctx.mobile_port,
+        },
         memory: MemoryStats {
             cache_bytes,
             blocklist_bytes,
@@ -592,8 +643,19 @@ async fn flush_cache_domain(
     StatusCode::NO_CONTENT
 }
 
-async fn health() -> Json<serde_json::Value> {
-    Json(serde_json::json!({ "status": "ok" }))
+/// Enriched `/health` handler shared between the main API and the mobile API.
+///
+/// Returns the cached `HealthMeta` assembled with live fields (LAN IP,
+/// uptime). Backward compatible with the previous minimal response in
+/// that `status` is still the first field and `"ok"` is still the value.
+/// The iOS companion app's `HealthInfo` Swift struct decodes the full
+/// response; any HTTP client asserting only on `"status"` keeps working.
+pub async fn health(State(ctx): State<Arc<ServerCtx>>) -> Json<crate::health::HealthResponse> {
+    let lan_ip = Some(*ctx.lan_ip.lock().unwrap());
+    Json(crate::health::HealthResponse::build(
+        &ctx.health_meta,
+        lan_ip,
+    ))
 }
 
 // --- Blocking handlers ---
@@ -905,12 +967,8 @@ async fn remove_route(
     }
 }
 
-async fn serve_ca(State(ctx): State<Arc<ServerCtx>>) -> Result<impl IntoResponse, StatusCode> {
-    let ca_path = ctx.data_dir.join(crate::tls::CA_FILE_NAME);
-    let bytes = tokio::task::spawn_blocking(move || std::fs::read(ca_path))
-        .await
-        .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
-        .map_err(|_| StatusCode::NOT_FOUND)?;
+pub async fn serve_ca(State(ctx): State<Arc<ServerCtx>>) -> Result<impl IntoResponse, StatusCode> {
+    let pem = ctx.ca_pem.as_deref().ok_or(StatusCode::NOT_FOUND)?;
     Ok((
         [
             (header::CONTENT_TYPE, "application/x-pem-file"),
@@ -920,7 +978,29 @@ async fn serve_ca(State(ctx): State<Arc<ServerCtx>>) -> Result<impl IntoResponse
             ),
             (header::CACHE_CONTROL, "public, max-age=86400"),
         ],
-        bytes,
+        pem.to_string(),
+    ))
+}
+
+async fn serve_qr(State(ctx): State<Arc<ServerCtx>>) -> Result<impl IntoResponse, StatusCode> {
+    if !ctx.mobile_enabled {
+        return Err(StatusCode::NOT_FOUND);
+    }
+    let lan_ip = *ctx.lan_ip.lock().unwrap();
+    let url = format!("http://{}:{}/mobileconfig", lan_ip, ctx.mobile_port);
+    let code = qrcode::QrCode::new(&url).map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+    let svg = code
+        .render::<qrcode::render::svg::Color>()
+        .min_dimensions(180, 180)
+        .dark_color(qrcode::render::svg::Color("#2c2418"))
+        .light_color(qrcode::render::svg::Color("#faf7f2"))
+        .build();
+    Ok((
+        [
+            (header::CONTENT_TYPE, "image/svg+xml"),
+            (header::CACHE_CONTROL, "no-store"),
+        ],
+        svg,
     ))
 }
 
@@ -959,44 +1039,10 @@ mod tests {
     use super::*;
     use axum::body::Body;
     use http::Request;
-    use std::sync::{Mutex, RwLock};
     use tower::ServiceExt;
 
     async fn test_ctx() -> Arc<ServerCtx> {
-        let socket = tokio::net::UdpSocket::bind("127.0.0.1:0").await.unwrap();
-        Arc::new(ServerCtx {
-            socket,
-            zone_map: std::collections::HashMap::new(),
-            cache: RwLock::new(crate::cache::DnsCache::new(100, 60, 86400)),
-            stats: Mutex::new(crate::stats::ServerStats::new()),
-            overrides: RwLock::new(crate::override_store::OverrideStore::new()),
-            blocklist: RwLock::new(crate::blocklist::BlocklistStore::new()),
-            query_log: Mutex::new(crate::query_log::QueryLog::new(100)),
-            services: Mutex::new(crate::service_store::ServiceStore::new()),
-            lan_peers: Mutex::new(crate::lan::PeerStore::new(90)),
-            forwarding_rules: Vec::new(),
-            upstream: Mutex::new(crate::forward::Upstream::Udp(
-                "127.0.0.1:53".parse().unwrap(),
-            )),
-            upstream_auto: false,
-            upstream_port: 53,
-            lan_ip: Mutex::new(std::net::Ipv4Addr::LOCALHOST),
-            timeout: std::time::Duration::from_secs(3),
-            proxy_tld: "numa".to_string(),
-            proxy_tld_suffix: ".numa".to_string(),
-            lan_enabled: false,
-            config_path: "/tmp/test-numa.toml".to_string(),
-            config_found: false,
-            config_dir: std::path::PathBuf::from("/tmp"),
-            data_dir: std::path::PathBuf::from("/tmp"),
-            tls_config: None,
-            upstream_mode: crate::config::UpstreamMode::Forward,
-            root_hints: Vec::new(),
-            srtt: RwLock::new(crate::srtt::SrttCache::new(true)),
-            inflight: Mutex::new(std::collections::HashMap::new()),
-            dnssec_enabled: false,
-            dnssec_strict: false,
-        })
+        Arc::new(crate::testutil::test_ctx().await)
     }
 
     #[tokio::test]

src/blocklist.rs

@@ -1,5 +1,5 @@
 use std::collections::HashSet;
-use std::time::Instant;
+use std::time::{Duration, Instant};
 
 use log::{info, warn};
 
@@ -81,66 +81,70 @@ impl BlocklistStore {
         if !self.enabled {
             return false;
         }
-
         if let Some(until) = self.paused_until {
             if Instant::now() < until {
                 return false;
             }
         }
-
-        if self.allowlist.contains(domain) {
+        let domain = Self::normalize(domain);
+        if Self::find_in_set(&domain, &self.allowlist).is_some() {
             return false;
         }
-
-        if self.domains.contains(domain) {
-            return true;
-        }
-
-        // Walk up: ads.tracker.example.com → tracker.example.com → example.com
-        let mut d = domain;
-        while let Some(dot) = d.find('.') {
-            d = &d[dot + 1..];
-            if self.allowlist.contains(d) {
-                return false;
-            }
-            if self.domains.contains(d) {
-                return true;
-            }
-        }
-
-        false
+        Self::find_in_set(&domain, &self.domains).is_some()
     }
 
-    /// Check if a domain is blocked and return the reason.
     pub fn check(&self, domain: &str) -> BlockCheckResult {
-        let domain = domain.to_lowercase();
-
         if !self.enabled {
             return BlockCheckResult::disabled();
         }
 
-        if self.allowlist.contains(&domain) {
-            return BlockCheckResult::allowed(&domain, "exact match in allowlist");
+        if let Some(until) = self.paused_until {
+            if Instant::now() < until {
+                return BlockCheckResult::disabled();
+            }
         }
 
-        if self.domains.contains(&domain) {
-            return BlockCheckResult::blocked(&domain, "exact match in blocklist");
+        let domain = Self::normalize(domain);
+
+        if let Some(matched) = Self::find_in_set(&domain, &self.allowlist) {
+            let reason = if matched == domain {
+                "exact match in allowlist"
+            } else {
+                "parent domain in allowlist"
+            };
+            return BlockCheckResult::allowed(matched, reason);
         }
 
-        let mut d = domain.as_str();
-        while let Some(dot) = d.find('.') {
-            d = &d[dot + 1..];
-            if self.allowlist.contains(d) {
-                return BlockCheckResult::allowed(d, "parent domain in allowlist");
-            }
-            if self.domains.contains(d) {
-                return BlockCheckResult::blocked(d, "parent domain in blocklist");
-            }
+        if let Some(matched) = Self::find_in_set(&domain, &self.domains) {
+            let reason = if matched == domain {
+                "exact match in blocklist"
+            } else {
+                "parent domain in blocklist"
+            };
+            return BlockCheckResult::blocked(matched, reason);
         }
 
         BlockCheckResult::not_blocked()
     }
 
+    fn normalize(domain: &str) -> String {
+        domain.to_lowercase().trim_end_matches('.').to_string()
+    }
+
+    fn find_in_set<'a>(domain: &'a str, set: &HashSet<String>) -> Option<&'a str> {
+        if set.contains(domain) {
+            return Some(domain);
+        }
+        let mut d = domain;
+        while let Some(dot) = d.find('.') {
+            d = &d[dot + 1..];
+            if set.contains(d) {
+                return Some(d);
+            }
+        }
+        None
+    }
+
     /// Atomically swap in a new domain set. Build the set outside the lock,
     /// then call this to swap — keeps lock hold time sub-microsecond.
     pub fn swap_domains(&mut self, domains: HashSet<String>, sources: Vec<String>) {
@@ -172,11 +176,11 @@ impl BlocklistStore {
     }
 
     pub fn add_to_allowlist(&mut self, domain: &str) {
-        self.allowlist.insert(domain.to_lowercase());
+        self.allowlist.insert(Self::normalize(domain));
     }
 
     pub fn remove_from_allowlist(&mut self, domain: &str) -> bool {
-        self.allowlist.remove(&domain.to_lowercase())
+        self.allowlist.remove(&Self::normalize(domain))
     }
 
     pub fn allowlist(&self) -> Vec<String> {
@@ -247,6 +251,97 @@ pub fn parse_blocklist(text: &str) -> HashSet<String> {
 mod tests {
     use super::*;
 
+    fn store_with(domains: &[&str], allowlist: &[&str]) -> BlocklistStore {
+        let mut store = BlocklistStore::new();
+        store.swap_domains(domains.iter().map(|s| s.to_string()).collect(), vec![]);
+        for d in allowlist {
+            store.add_to_allowlist(d);
+        }
+        store
+    }
+
+    #[test]
+    fn exact_block() {
+        let store = store_with(&["ads.example.com"], &[]);
+        assert!(store.is_blocked("ads.example.com"));
+        assert!(!store.is_blocked("example.com"));
+    }
+
+    #[test]
+    fn parent_block_covers_subdomain() {
+        let store = store_with(&["tracker.com"], &[]);
+        assert!(store.is_blocked("tracker.com"));
+        assert!(store.is_blocked("www.tracker.com"));
+        assert!(store.is_blocked("deep.sub.tracker.com"));
+    }
+
+    #[test]
+    fn exact_allowlist_unblocks() {
+        let store = store_with(&["ads.example.com"], &["ads.example.com"]);
+        assert!(!store.is_blocked("ads.example.com"));
+    }
+
+    #[test]
+    fn parent_allowlist_unblocks_subdomain() {
+        let store = store_with(&["example.com", "www.example.com"], &["example.com"]);
+        assert!(!store.is_blocked("example.com"));
+        assert!(!store.is_blocked("www.example.com"));
+        assert!(!store.is_blocked("sub.deep.example.com"));
+    }
+
+    #[test]
+    fn allowlist_does_not_unblock_sibling() {
+        let store = store_with(
+            &["www.example.com", "ads.example.com"],
+            &["www.example.com"],
+        );
+        assert!(!store.is_blocked("www.example.com"));
+        assert!(store.is_blocked("ads.example.com"));
+    }
+
+    #[test]
+    fn check_reports_parent_allowlist() {
+        let store = store_with(
+            &["goatcounter.com", "www.goatcounter.com"],
+            &["goatcounter.com"],
+        );
+        let result = store.check("www.goatcounter.com");
+        assert!(!result.blocked);
+        assert_eq!(result.matched_rule.as_deref(), Some("goatcounter.com"));
+    }
+
+    #[test]
+    fn disabled_never_blocks() {
+        let mut store = store_with(&["ads.example.com"], &[]);
+        store.set_enabled(false);
+        assert!(!store.is_blocked("ads.example.com"));
+    }
+
+    #[test]
+    fn trailing_dot_normalized() {
+        let store = store_with(&["ads.example.com"], &["safe.example.com"]);
+        assert!(store.is_blocked("ads.example.com."));
+        assert!(!store.is_blocked("safe.example.com."));
+        let result = store.check("ads.example.com.");
+        assert!(result.blocked);
+    }
+
+    #[test]
+    fn case_insensitive() {
+        let store = store_with(&["ads.example.com"], &["safe.example.com"]);
+        assert!(store.is_blocked("ADS.Example.COM"));
+        assert!(!store.is_blocked("Safe.Example.COM"));
+    }
+
+    #[test]
+    fn domain_in_neither_list() {
+        let store = store_with(&["ads.example.com"], &[]);
+        let result = store.check("clean.example.org");
+        assert!(!result.blocked);
+        assert_eq!(result.reason, "not in blocklist");
+        assert!(result.matched_rule.is_none());
+    }
+
     #[test]
     fn heap_bytes_grows_with_domains() {
         let mut store = BlocklistStore::new();
@@ -260,27 +355,139 @@ mod tests {
     }
 }
 
+const RETRY_DELAYS_SECS: &[u64] = &[2, 10, 30];
+
 pub async fn download_blocklists(lists: &[String]) -> Vec<(String, String)> {
     let client = reqwest::Client::builder()
-        .timeout(std::time::Duration::from_secs(30))
+        .timeout(Duration::from_secs(30))
         .gzip(true)
         .build()
         .unwrap_or_default();
 
-    let mut results = Vec::new();
+    let fetches = lists.iter().map(|url| {
+        let client = &client;
+        async move {
+            let text = fetch_with_retry(client, url).await?;
+            info!("downloaded blocklist: {} ({} bytes)", url, text.len());
+            Some((url.clone(), text))
+        }
+    });
+    futures::future::join_all(fetches)
+        .await
+        .into_iter()
+        .flatten()
+        .collect()
+}
 
-    for url in lists {
-        match client.get(url).send().await {
-            Ok(resp) => match resp.text().await {
-                Ok(text) => {
-                    info!("downloaded blocklist: {} ({} bytes)", url, text.len());
-                    results.push((url.clone(), text));
-                }
-                Err(e) => warn!("failed to read blocklist body {}: {}", url, e),
-            },
-            Err(e) => warn!("failed to download blocklist {}: {}", url, e),
+async fn fetch_with_retry(client: &reqwest::Client, url: &str) -> Option<String> {
+    fetch_with_retry_delays(client, url, RETRY_DELAYS_SECS).await
+}
+
+async fn fetch_with_retry_delays(
+    client: &reqwest::Client,
+    url: &str,
+    delays: &[u64],
+) -> Option<String> {
+    let total = delays.len() + 1;
+    for attempt in 1..=total {
+        match fetch_once(client, url).await {
+            Ok(text) => return Some(text),
+            Err(msg) if attempt < total => {
+                let delay = delays[attempt - 1];
+                warn!(
+                    "blocklist {} attempt {}/{} failed: {} — retrying in {}s",
+                    url, attempt, total, msg, delay
+                );
+                tokio::time::sleep(Duration::from_secs(delay)).await;
+            }
+            Err(msg) => {
+                warn!(
+                    "blocklist {} attempt {}/{} failed: {} — giving up",
+                    url, attempt, total, msg
+                );
+            }
         }
     }
-
-    results
+    None
+}
+
+async fn fetch_once(client: &reqwest::Client, url: &str) -> Result<String, String> {
+    let resp = client
+        .get(url)
+        .send()
+        .await
+        .map_err(|e| format_error_chain(&e))?;
+    resp.text().await.map_err(|e| format_error_chain(&e))
+}
+
+fn format_error_chain(e: &(dyn std::error::Error + 'static)) -> String {
+    let mut parts = vec![e.to_string()];
+    let mut src = e.source();
+    while let Some(s) = src {
+        parts.push(s.to_string());
+        src = s.source();
+    }
+    parts.join(": ")
+}
+
+#[cfg(test)]
+mod retry_tests {
+    use super::*;
+    use std::net::SocketAddr;
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+    use tokio::net::TcpListener;
+
+    async fn flaky_http_server(drop_first_n: usize, body: &'static str) -> SocketAddr {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener.local_addr().unwrap();
+        tokio::spawn(async move {
+            for _ in 0..drop_first_n {
+                if let Ok((sock, _)) = listener.accept().await {
+                    drop(sock);
+                }
+            }
+            loop {
+                let Ok((mut sock, _)) = listener.accept().await else {
+                    return;
+                };
+                tokio::spawn(async move {
+                    let mut buf = [0u8; 2048];
+                    let _ = sock.read(&mut buf).await;
+                    let response = format!(
+                        "HTTP/1.1 200 OK\r\nContent-Length: {}\r\nContent-Type: text/plain\r\nConnection: close\r\n\r\n{}",
+                        body.len(),
+                        body,
+                    );
+                    let _ = sock.write_all(response.as_bytes()).await;
+                    let _ = sock.shutdown().await;
+                });
+            }
+        });
+        addr
+    }
+
+    fn zero_delays() -> Vec<u64> {
+        vec![0; RETRY_DELAYS_SECS.len()]
+    }
+
+    #[tokio::test]
+    async fn retry_succeeds_on_final_attempt() {
+        let body = "ads.example.com\ntracker.example.net\n";
+        let delays = zero_delays();
+        let addr = flaky_http_server(delays.len(), body).await;
+        let client = reqwest::Client::new();
+        let url = format!("http://{addr}/");
+        let result = fetch_with_retry_delays(&client, &url, &delays).await;
+        assert_eq!(result.as_deref(), Some(body));
+    }
+
+    #[tokio::test]
+    async fn retry_gives_up_when_all_attempts_fail() {
+        let delays = zero_delays();
+        let addr = flaky_http_server(delays.len() + 2, "unreachable").await;
+        let client = reqwest::Client::new();
+        let url = format!("http://{addr}/");
+        let result = fetch_with_retry_delays(&client, &url, &delays).await;
+        assert_eq!(result, None);
+    }
 }

src/cache.rs

@@ -1,9 +1,26 @@
 use std::collections::HashMap;
 use std::time::{Duration, Instant};
 
+use crate::buffer::BytePacketBuffer;
 use crate::packet::DnsPacket;
 use crate::question::QueryType;
-use crate::record::DnsRecord;
+use crate::wire::WireMeta;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Freshness {
+    /// Within TTL, no action needed.
+    Fresh,
+    /// Within TTL but <10% remaining — trigger background prefetch.
+    NearExpiry,
+    /// Past TTL but within stale window — serve with TTL=1, trigger background refresh.
+    Stale,
+}
+
+impl Freshness {
+    pub fn needs_refresh(self) -> bool {
+        matches!(self, Freshness::NearExpiry | Freshness::Stale)
+    }
+}
 
 #[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
 pub enum DnssecStatus {
@@ -26,14 +43,16 @@ impl DnssecStatus {
 }
 
 struct CacheEntry {
-    packet: DnsPacket,
+    wire: Vec<u8>,
+    meta: WireMeta,
     inserted_at: Instant,
     ttl: Duration,
     dnssec_status: DnssecStatus,
 }
 
-/// DNS cache using a two-level map (domain -> query_type -> entry) so that
-/// lookups can borrow `&str` instead of allocating a `String` key.
+const STALE_WINDOW: Duration = Duration::from_secs(3600);
+
+/// DNS cache with serve-stale (RFC 8767). Stores raw wire bytes.
 pub struct DnsCache {
     entries: HashMap<String, HashMap<QueryType, CacheEntry>>,
     entry_count: usize,
@@ -53,54 +72,60 @@ impl DnsCache {
         }
     }
 
-    /// Read-only lookup — expired entries are left in place (cleaned up on insert).
-    pub fn lookup(&self, domain: &str, qtype: QueryType) -> Option<DnsPacket> {
-        self.lookup_with_status(domain, qtype).map(|(pkt, _)| pkt)
-    }
-
-    pub fn lookup_with_status(
+    /// Look up cached wire bytes, patching ID and TTLs in the returned copy.
+    /// Implements serve-stale (RFC 8767): expired entries within STALE_WINDOW
+    /// are returned with TTL=1 and `stale=true` so callers can revalidate.
+    pub fn lookup_wire(
         &self,
         domain: &str,
         qtype: QueryType,
-    ) -> Option<(DnsPacket, DnssecStatus)> {
+        new_id: u16,
+    ) -> Option<(Vec<u8>, DnssecStatus, Freshness)> {
         let type_map = self.entries.get(domain)?;
         let entry = type_map.get(&qtype)?;
 
         let elapsed = entry.inserted_at.elapsed();
-        if elapsed >= entry.ttl {
+        let (remaining, freshness) = if elapsed < entry.ttl {
+            let secs = (entry.ttl - elapsed).as_secs() as u32;
+            let f = if elapsed * 10 >= entry.ttl * 9 {
+                Freshness::NearExpiry
+            } else {
+                Freshness::Fresh
+            };
+            (secs.max(1), f)
+        } else if elapsed < entry.ttl + STALE_WINDOW {
+            (1, Freshness::Stale)
+        } else {
             return None;
-        }
+        };
 
-        let remaining_secs = (entry.ttl - elapsed).as_secs() as u32;
-        let remaining = remaining_secs.max(1);
+        let mut wire = entry.wire.clone();
+        crate::wire::patch_id(&mut wire, new_id);
+        crate::wire::patch_ttls(&mut wire, &entry.meta.ttl_offsets, remaining);
 
-        let mut packet = entry.packet.clone();
-        adjust_ttls(&mut packet.answers, remaining);
-        adjust_ttls(&mut packet.authorities, remaining);
-        adjust_ttls(&mut packet.resources, remaining);
-
-        Some((packet, entry.dnssec_status))
+        Some((wire, entry.dnssec_status, freshness))
     }
 
-    pub fn insert(&mut self, domain: &str, qtype: QueryType, packet: &DnsPacket) {
-        self.insert_with_status(domain, qtype, packet, DnssecStatus::Indeterminate);
-    }
-
-    pub fn insert_with_status(
+    pub fn insert_wire(
         &mut self,
         domain: &str,
         qtype: QueryType,
-        packet: &DnsPacket,
+        wire: &[u8],
         dnssec_status: DnssecStatus,
     ) {
+        let meta = match crate::wire::scan_ttl_offsets(wire) {
+            Ok(m) => m,
+            Err(_) => return, // malformed wire, skip
+        };
+
         if self.entry_count >= self.max_entries {
             self.evict_expired();
             if self.entry_count >= self.max_entries {
-                return;
+                self.evict_stalest();
             }
         }
 
-        let min_ttl = extract_min_ttl(&packet.answers)
+        let min_ttl = crate::wire::min_ttl_from_wire(wire, &meta)
             .unwrap_or(self.min_ttl)
             .clamp(self.min_ttl, self.max_ttl);
 
@@ -117,7 +142,8 @@ impl DnsCache {
         type_map.insert(
             qtype,
             CacheEntry {
-                packet: packet.clone(),
+                wire: wire.to_vec(),
+                meta,
                 inserted_at: Instant::now(),
                 ttl: Duration::from_secs(min_ttl as u64),
                 dnssec_status,
@@ -125,6 +151,64 @@ impl DnsCache {
         );
     }
 
+    /// Read-only lookup — expired entries are left in place (cleaned up on insert).
+    pub fn lookup(&self, domain: &str, qtype: QueryType) -> Option<DnsPacket> {
+        self.lookup_with_status(domain, qtype)
+            .map(|(pkt, _, _)| pkt)
+    }
+
+    pub fn lookup_with_status(
+        &self,
+        domain: &str,
+        qtype: QueryType,
+    ) -> Option<(DnsPacket, DnssecStatus, Freshness)> {
+        let (wire, status, freshness) = self.lookup_wire(domain, qtype, 0)?;
+        let mut buf = BytePacketBuffer::from_bytes(&wire);
+        let pkt = DnsPacket::from_buffer(&mut buf).ok()?;
+        Some((pkt, status, freshness))
+    }
+
+    pub fn insert(&mut self, domain: &str, qtype: QueryType, packet: &DnsPacket) {
+        self.insert_with_status(domain, qtype, packet, DnssecStatus::Indeterminate);
+    }
+
+    pub fn insert_with_status(
+        &mut self,
+        domain: &str,
+        qtype: QueryType,
+        packet: &DnsPacket,
+        dnssec_status: DnssecStatus,
+    ) {
+        let mut buf = BytePacketBuffer::new();
+        if packet.write(&mut buf).is_err() {
+            return;
+        }
+        self.insert_wire(domain, qtype, buf.filled(), dnssec_status);
+    }
+
+    pub fn ttl_remaining(&self, domain: &str, qtype: QueryType) -> Option<(u32, u32)> {
+        let type_map = self.entries.get(domain)?;
+        let entry = type_map.get(&qtype)?;
+        let elapsed = entry.inserted_at.elapsed();
+        if elapsed >= entry.ttl {
+            return None;
+        }
+        let total = entry.ttl.as_secs() as u32;
+        let remaining = (entry.ttl - elapsed).as_secs() as u32;
+        Some((remaining, total))
+    }
+
+    pub fn needs_warm(&self, domain: &str) -> bool {
+        for qtype in [QueryType::A, QueryType::AAAA] {
+            match self.ttl_remaining(domain, qtype) {
+                None => return true,
+                Some((remaining, total)) if remaining < total / 4 => return true,
+                _ => {}
+            }
+        }
+        false
+    }
+
     pub fn len(&self) -> usize {
         self.entry_count
     }
@@ -156,7 +240,8 @@ impl DnsCache {
                 + 1;
             total += type_map.capacity() * inner_slot;
             for entry in type_map.values() {
-                total += entry.packet.heap_bytes();
+                total += entry.wire.capacity()
+                    + entry.meta.ttl_offsets.capacity() * std::mem::size_of::<usize>();
             }
         }
         total
@@ -197,6 +282,34 @@ impl DnsCache {
         });
         self.entry_count -= count;
     }
+
+    /// Evict the single entry closest to (or furthest past) expiry.
+    fn evict_stalest(&mut self) {
+        let mut worst: Option<(String, QueryType, Duration)> = None;
+        for (domain, type_map) in &self.entries {
+            for (qtype, entry) in type_map {
+                let age = entry.inserted_at.elapsed();
+                let remaining = entry.ttl.saturating_sub(age);
+                match &worst {
+                    None => worst = Some((domain.clone(), *qtype, remaining)),
+                    Some((_, _, w)) if remaining < *w => {
+                        worst = Some((domain.clone(), *qtype, remaining));
+                    }
+                    _ => {}
+                }
+            }
+        }
+        if let Some((domain, qtype, _)) = worst {
+            if let Some(type_map) = self.entries.get_mut(&domain) {
+                if type_map.remove(&qtype).is_some() {
+                    self.entry_count -= 1;
+                }
+                if type_map.is_empty() {
+                    self.entries.remove(&domain);
+                }
+            }
+        }
+    }
 }
 
 pub struct CacheInfo {
@@ -205,20 +318,11 @@ pub struct CacheInfo {
     pub ttl_remaining: u32,
 }
 
-fn extract_min_ttl(records: &[DnsRecord]) -> Option<u32> {
-    records.iter().map(|r| r.ttl()).min()
-}
-
-fn adjust_ttls(records: &mut [DnsRecord], new_ttl: u32) {
-    for record in records.iter_mut() {
-        record.set_ttl(new_ttl);
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
     use crate::packet::DnsPacket;
+    use crate::record::DnsRecord;
 
     #[test]
     fn heap_bytes_grows_with_entries() {
@@ -233,4 +337,66 @@ mod tests {
         cache.insert("example.com", QueryType::A, &pkt);
         assert!(cache.heap_bytes() > empty);
     }
+
+    #[test]
+    fn ttl_remaining_returns_values_for_fresh_entry() {
+        let mut cache = DnsCache::new(100, 60, 3600);
+        let mut pkt = DnsPacket::new();
+        pkt.answers.push(DnsRecord::A {
+            domain: "example.com".into(),
+            addr: "1.2.3.4".parse().unwrap(),
+            ttl: 300,
+        });
+        cache.insert("example.com", QueryType::A, &pkt);
+        let (remaining, total) = cache.ttl_remaining("example.com", QueryType::A).unwrap();
+        assert_eq!(total, 300);
+        assert!(remaining <= 300);
+        assert!(remaining > 0);
+    }
+
+    #[test]
+    fn ttl_remaining_none_for_missing() {
+        let cache = DnsCache::new(100, 1, 3600);
+        assert!(cache.ttl_remaining("missing.com", QueryType::A).is_none());
+    }
+
+    #[test]
+    fn needs_warm_true_when_missing() {
+        let cache = DnsCache::new(100, 1, 3600);
+        assert!(cache.needs_warm("missing.com"));
+    }
+
+    #[test]
+    fn needs_warm_false_when_fresh() {
+        let mut cache = DnsCache::new(100, 1, 3600);
+        let mut pkt_a = DnsPacket::new();
+        pkt_a.answers.push(DnsRecord::A {
+            domain: "example.com".into(),
+            addr: "1.2.3.4".parse().unwrap(),
+            ttl: 300,
+        });
+        let mut pkt_aaaa = DnsPacket::new();
+        pkt_aaaa.answers.push(DnsRecord::AAAA {
+            domain: "example.com".into(),
+            addr: "::1".parse().unwrap(),
+            ttl: 300,
+        });
+        cache.insert("example.com", QueryType::A, &pkt_a);
+        cache.insert("example.com", QueryType::AAAA, &pkt_aaaa);
+        assert!(!cache.needs_warm("example.com"));
+    }
+
+    #[test]
+    fn needs_warm_true_when_only_a_cached() {
+        let mut cache = DnsCache::new(100, 1, 3600);
+        let mut pkt = DnsPacket::new();
+        pkt.answers.push(DnsRecord::A {
+            domain: "example.com".into(),
+            addr: "1.2.3.4".parse().unwrap(),
+            ttl: 300,
+        });
+        cache.insert("example.com", QueryType::A, &pkt);
+        // AAAA missing → needs warm
+        assert!(cache.needs_warm("example.com"));
+    }
 }

src/config.rs

@@ -1,7 +1,7 @@
 use std::collections::HashMap;
-use std::net::Ipv4Addr;
-use std::net::Ipv6Addr;
+use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
 use std::path::{Path, PathBuf};
+use std::time::Duration;
 
 use serde::Deserialize;
 
@@ -31,6 +31,54 @@ pub struct Config {
     pub dnssec: DnssecConfig,
     #[serde(default)]
     pub dot: DotConfig,
+    #[serde(default)]
+    pub mobile: MobileConfig,
+    #[serde(default)]
+    pub forwarding: Vec<ForwardingRuleConfig>,
+}
+
+#[derive(Deserialize, Clone, Debug)]
+pub struct ForwardingRuleConfig {
+    #[serde(deserialize_with = "string_or_vec")]
+    pub suffix: Vec<String>,
+    #[serde(deserialize_with = "string_or_vec")]
+    pub upstream: Vec<String>,
+}
+
+impl ForwardingRuleConfig {
+    fn to_runtime_rules(&self) -> Result<Vec<crate::system_dns::ForwardingRule>> {
+        if self.upstream.is_empty() {
+            return Err(format!(
+                "forwarding rule for suffix {:?}: upstream must not be empty",
+                self.suffix
+            )
+            .into());
+        }
+        let mut primary = Vec::with_capacity(self.upstream.len());
+        for s in &self.upstream {
+            let u = crate::forward::parse_upstream(s, 53)
+                .map_err(|e| format!("forwarding rule for upstream '{}': {}", s, e))?;
+            primary.push(u);
+        }
+        let pool = crate::forward::UpstreamPool::new(primary, vec![]);
+        Ok(self
+            .suffix
+            .iter()
+            .map(|s| crate::system_dns::ForwardingRule::new(s.clone(), pool.clone()))
+            .collect())
+    }
+}
+
+pub fn merge_forwarding_rules(
+    config_rules: &[ForwardingRuleConfig],
+    discovered: Vec<crate::system_dns::ForwardingRule>,
+) -> Result<Vec<crate::system_dns::ForwardingRule>> {
+    let mut merged: Vec<crate::system_dns::ForwardingRule> = Vec::new();
+    for rule in config_rules {
+        merged.extend(rule.to_runtime_rules()?);
+    }
+    merged.extend(discovered);
+    Ok(merged)
 }
 
 #[derive(Deserialize)]
@@ -45,6 +93,12 @@ pub struct ServerConfig {
     /// Defaults to `crate::data_dir()` (platform-specific system path) if unset.
     #[serde(default)]
     pub data_dir: Option<PathBuf>,
+    /// Synthesize NODATA (NOERROR + empty answer) for AAAA queries, and
+    /// strip `ipv6hint` from HTTPS/SVCB responses (RFC 9460). For IPv4-only
+    /// networks where Happy Eyeballs fallback adds latency. Local zones,
+    /// overrides, and the service proxy are not affected. Default false.
+    #[serde(default)]
+    pub filter_aaaa: bool,
 }
 
 impl Default for ServerConfig {
@@ -54,6 +108,7 @@ impl Default for ServerConfig {
             api_port: default_api_port(),
             api_bind_addr: default_api_bind_addr(),
             data_dir: None,
+            filter_aaaa: false,
         }
     }
 }
@@ -79,6 +134,7 @@ pub enum UpstreamMode {
     #[default]
     Forward,
     Recursive,
+    Odoh,
 }
 
 impl UpstreamMode {
@@ -87,6 +143,20 @@ impl UpstreamMode {
             UpstreamMode::Auto => "auto",
             UpstreamMode::Forward => "forward",
             UpstreamMode::Recursive => "recursive",
+            UpstreamMode::Odoh => "odoh",
+        }
+    }
+
+    /// Hedging duplicates the in-flight query against the same upstream to
+    /// rescue tail latency. Beneficial for UDP/DoH/DoT (cheap retransmit /
+    /// h2 stream multiplexing). For ODoH it doubles the relay's HPKE
+    /// seal/unseal load and the sealed-byte footprint a passive observer
+    /// can correlate, with no latency win — the relay hop dominates either
+    /// way. Force-zero in oblivious mode regardless of `hedge_ms`.
+    pub fn hedge_delay(self, hedge_ms: u64) -> Duration {
+        match self {
+            UpstreamMode::Odoh => Duration::ZERO,
+            _ => Duration::from_millis(hedge_ms),
         }
     }
 }
@@ -95,34 +165,189 @@ impl UpstreamMode {
 pub struct UpstreamConfig {
     #[serde(default)]
     pub mode: UpstreamMode,
-    #[serde(default = "default_upstream_addr")]
-    pub address: String,
+    #[serde(default, deserialize_with = "string_or_vec")]
+    pub address: Vec<String>,
     #[serde(default = "default_upstream_port")]
     pub port: u16,
+    #[serde(default, deserialize_with = "string_or_vec")]
+    pub fallback: Vec<String>,
     #[serde(default = "default_timeout_ms")]
     pub timeout_ms: u64,
+    #[serde(default = "default_hedge_ms")]
+    pub hedge_ms: u64,
     #[serde(default = "default_root_hints")]
     pub root_hints: Vec<String>,
     #[serde(default = "default_prime_tlds")]
     pub prime_tlds: Vec<String>,
     #[serde(default = "default_srtt")]
     pub srtt: bool,
+
+    /// Only used when `mode = "odoh"`. Full https:// URL of the relay
+    /// endpoint (including path, e.g. `https://odoh-relay.numa.rs/relay`).
+    #[serde(default)]
+    pub relay: Option<String>,
+    /// Only used when `mode = "odoh"`. Full https:// URL of the target
+    /// resolver (`https://odoh.cloudflare-dns.com/dns-query`).
+    #[serde(default)]
+    pub target: Option<String>,
+    /// Only used when `mode = "odoh"`. When true (the default), relay failure
+    /// returns SERVFAIL instead of downgrading to the `fallback` upstream —
+    /// a user who configured ODoH rarely wants a silent non-oblivious path.
+    #[serde(default)]
+    pub strict: Option<bool>,
+
+    /// Bootstrap IP for the relay host, used when numa is its own system
+    /// resolver (otherwise the ODoH HTTPS client loops resolving through
+    /// itself). TLS still validates the cert against `relay`'s hostname.
+    #[serde(default)]
+    pub relay_ip: Option<IpAddr>,
+
+    /// Same as `relay_ip` but for the target host.
+    #[serde(default)]
+    pub target_ip: Option<IpAddr>,
 }
 
 impl Default for UpstreamConfig {
     fn default() -> Self {
         UpstreamConfig {
             mode: UpstreamMode::default(),
-            address: default_upstream_addr(),
+            address: Vec::new(),
             port: default_upstream_port(),
+            fallback: Vec::new(),
             timeout_ms: default_timeout_ms(),
+            hedge_ms: default_hedge_ms(),
             root_hints: default_root_hints(),
             prime_tlds: default_prime_tlds(),
             srtt: default_srtt(),
+            relay: None,
+            target: None,
+            strict: None,
+            relay_ip: None,
+            target_ip: None,
         }
     }
 }
 
+/// Parsed ODoH config fields. `mode = "odoh"` requires both URLs to be
+/// present, to parse as `https://`, and to resolve to distinct hosts.
+#[derive(Debug)]
+pub struct OdohUpstream {
+    pub relay_url: String,
+    pub relay_host: String,
+    pub target_host: String,
+    pub target_path: String,
+    pub strict: bool,
+    pub relay_bootstrap: Option<SocketAddr>,
+    pub target_bootstrap: Option<SocketAddr>,
+}
+
+impl UpstreamConfig {
+    /// Validate and extract ODoH-specific fields. Called during `load_config`
+    /// so misconfigured ODoH fails fast at startup, the same care we take
+    /// with the DNSSEC strict boot check.
+    pub fn odoh_upstream(&self) -> Result<OdohUpstream> {
+        let relay = self
+            .relay
+            .as_deref()
+            .ok_or("mode = \"odoh\" requires upstream.relay")?;
+        let target = self
+            .target
+            .as_deref()
+            .ok_or("mode = \"odoh\" requires upstream.target")?;
+
+        let relay_url = reqwest::Url::parse(relay)
+            .map_err(|e| format!("upstream.relay invalid URL '{}': {}", relay, e))?;
+        let target_url = reqwest::Url::parse(target)
+            .map_err(|e| format!("upstream.target invalid URL '{}': {}", target, e))?;
+
+        if relay_url.scheme() != "https" || target_url.scheme() != "https" {
+            return Err("upstream.relay and upstream.target must both use https://".into());
+        }
+        let relay_host = relay_url
+            .host_str()
+            .ok_or("upstream.relay must include a host")?
+            .to_string();
+        let target_host = target_url
+            .host_str()
+            .ok_or("upstream.target must include a host")?
+            .to_string();
+
+        if relay_host == target_host {
+            return Err(format!(
+                "upstream.relay and upstream.target resolve to the same host ({}); the privacy property requires distinct operators",
+                relay_host
+            )
+            .into());
+        }
+        if let Some(shared) = shared_registrable_domain(&relay_host, &target_host) {
+            return Err(format!(
+                "upstream.relay ({}) and upstream.target ({}) share the registrable domain ({}); the privacy property requires distinct operators",
+                relay_host, target_host, shared
+            )
+            .into());
+        }
+        let target_path = if target_url.path().is_empty() {
+            "/".to_string()
+        } else {
+            target_url.path().to_string()
+        };
+
+        let relay_port = relay_url.port_or_known_default().unwrap_or(443);
+        let target_port = target_url.port_or_known_default().unwrap_or(443);
+
+        Ok(OdohUpstream {
+            relay_url: relay.to_string(),
+            relay_host,
+            target_host,
+            target_path,
+            strict: self.strict.unwrap_or(true),
+            relay_bootstrap: self.relay_ip.map(|ip| SocketAddr::new(ip, relay_port)),
+            target_bootstrap: self.target_ip.map(|ip| SocketAddr::new(ip, target_port)),
+        })
+    }
+}
+
+/// Returns the registrable domain (eTLD+1) shared by both hosts, if any.
+/// Fails open on hosts the PSL can't parse (IP literals, bare TLDs).
+fn shared_registrable_domain(relay_host: &str, target_host: &str) -> Option<String> {
+    let relay = psl::domain(relay_host.as_bytes())?;
+    let target = psl::domain(target_host.as_bytes())?;
+    if relay.as_bytes() == target.as_bytes() {
+        std::str::from_utf8(relay.as_bytes())
+            .ok()
+            .map(str::to_owned)
+    } else {
+        None
+    }
+}
+
+fn string_or_vec<'de, D>(deserializer: D) -> std::result::Result<Vec<String>, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    struct Visitor;
+    impl<'de> serde::de::Visitor<'de> for Visitor {
+        type Value = Vec<String>;
+        fn expecting(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+            f.write_str("string or array of strings")
+        }
+        fn visit_str<E: serde::de::Error>(self, v: &str) -> std::result::Result<Self::Value, E> {
+            Ok(vec![v.to_string()])
+        }
+        fn visit_seq<A: serde::de::SeqAccess<'de>>(
+            self,
+            mut seq: A,
+        ) -> std::result::Result<Self::Value, A::Error> {
+            let mut v = Vec::new();
+            while let Some(s) = seq.next_element::<String>()? {
+                v.push(s);
+            }
+            Ok(v)
+        }
+    }
+    deserializer.deserialize_any(Visitor)
+}
+
 fn default_true() -> bool {
     true
 }
@@ -200,15 +425,15 @@ fn default_root_hints() -> Vec<String> {
     ]
 }
 
-fn default_upstream_addr() -> String {
-    String::new() // empty = auto-detect from system resolver
-}
 fn default_upstream_port() -> u16 {
     53
 }
 fn default_timeout_ms() -> u64 {
     5000
 }
+fn default_hedge_ms() -> u64 {
+    10
+}
 
 #[derive(Deserialize)]
 pub struct CacheConfig {
@@ -218,6 +443,8 @@ pub struct CacheConfig {
     pub min_ttl: u32,
     #[serde(default = "default_max_ttl")]
     pub max_ttl: u32,
+    #[serde(default)]
+    pub warm: Vec<String>,
 }
 
 impl Default for CacheConfig {
@@ -226,12 +453,13 @@ impl Default for CacheConfig {
             max_entries: default_max_entries(),
             min_ttl: default_min_ttl(),
             max_ttl: default_max_ttl(),
+            warm: Vec::new(),
         }
     }
 }
 
 fn default_max_entries() -> usize {
-    10000
+    100_000
 }
 fn default_min_ttl() -> u32 {
     60
@@ -379,7 +607,7 @@ pub struct DnssecConfig {
 
 #[derive(Deserialize, Clone)]
 pub struct DotConfig {
-    #[serde(default)]
+    #[serde(default = "default_dot_enabled")]
     pub enabled: bool,
     #[serde(default = "default_dot_port")]
     pub port: u16,
@@ -396,7 +624,7 @@ pub struct DotConfig {
 impl Default for DotConfig {
     fn default() -> Self {
         DotConfig {
-            enabled: false,
+            enabled: default_dot_enabled(),
             port: default_dot_port(),
             bind_addr: default_dot_bind_addr(),
             cert_path: None,
@@ -405,6 +633,9 @@ impl Default for DotConfig {
     }
 }
 
+fn default_dot_enabled() -> bool {
+    true
+}
 fn default_dot_port() -> u16 {
     853
 }
@@ -412,6 +643,53 @@ fn default_dot_bind_addr() -> String {
     "0.0.0.0".to_string()
 }
 
+/// Configuration for the mobile API — a persistent HTTP listener that
+/// serves a read-only subset of routes (`/health`, `/ca.pem`,
+/// `/mobileconfig`, `/ca.mobileconfig`) on a LAN-reachable port, for
+/// consumption by the iOS/Android companion apps.
+///
+/// Unlike the main API (port 5380, localhost-only by default, supports
+/// state-mutating routes), the mobile API is safe to expose on the LAN
+/// because every route is idempotent and read-only.
+#[derive(Deserialize, Clone)]
+pub struct MobileConfig {
+    /// If true, spawn the mobile API listener at startup. **Default false.**
+    /// Opt-in because the listener binds to the LAN by default and exposes
+    /// a few read-only endpoints to any device on the same network (`/health`,
+    /// `/ca.pem`, `/mobileconfig`, `/ca.mobileconfig`). None of those are
+    /// cryptographically sensitive (the CA private key is never served),
+    /// but users should enable this explicitly rather than have a new
+    /// LAN-reachable port appear after an upgrade.
+    #[serde(default)]
+    pub enabled: bool,
+    /// Port for the mobile API. Default 8765.
+    #[serde(default = "default_mobile_port")]
+    pub port: u16,
+    /// Bind address for the mobile API. Default "0.0.0.0" (all interfaces)
+    /// so phones on the LAN can reach it. Set to "127.0.0.1" to restrict
+    /// to localhost — useful if you're running behind another front-end.
+    #[serde(default = "default_mobile_bind_addr")]
+    pub bind_addr: String,
+}
+
+impl Default for MobileConfig {
+    fn default() -> Self {
+        MobileConfig {
+            enabled: false,
+            port: default_mobile_port(),
+            bind_addr: default_mobile_bind_addr(),
+        }
+    }
+}
+
+fn default_mobile_port() -> u16 {
+    8765
+}
+
+fn default_mobile_bind_addr() -> String {
+    "0.0.0.0".to_string()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -446,6 +724,17 @@ mod tests {
         assert!(config.lan.enabled);
     }
 
+    #[test]
+    fn filter_aaaa_defaults_false() {
+        assert!(!ServerConfig::default().filter_aaaa);
+    }
+
+    #[test]
+    fn filter_aaaa_parses_from_server_section() {
+        let config: Config = toml::from_str("[server]\nfilter_aaaa = true").unwrap();
+        assert!(config.server.filter_aaaa);
+    }
+
     #[test]
     fn custom_bind_addrs_parse() {
         let toml = r#"
@@ -476,6 +765,496 @@ mod tests {
         assert!(config.services[0].routes[0].strip);
         assert!(!config.services[0].routes[1].strip); // default false
     }
+
+    #[test]
+    fn address_string_parses_to_vec() {
+        let config: Config = toml::from_str("[upstream]\naddress = \"1.2.3.4\"").unwrap();
+        assert_eq!(config.upstream.address, vec!["1.2.3.4"]);
+    }
+
+    #[test]
+    fn address_array_parses() {
+        let config: Config =
+            toml::from_str("[upstream]\naddress = [\"1.2.3.4\", \"5.6.7.8:5353\"]").unwrap();
+        assert_eq!(config.upstream.address, vec!["1.2.3.4", "5.6.7.8:5353"]);
+    }
+
+    #[test]
+    fn fallback_array_parses() {
+        let config: Config =
+            toml::from_str("[upstream]\nfallback = [\"8.8.8.8\", \"1.1.1.1\"]").unwrap();
+        assert_eq!(config.upstream.fallback, vec!["8.8.8.8", "1.1.1.1"]);
+    }
+
+    #[test]
+    fn fallback_string_parses_as_singleton_vec() {
+        let config: Config =
+            toml::from_str("[upstream]\nfallback = \"tls://1.1.1.1#cloudflare-dns.com\"").unwrap();
+        assert_eq!(
+            config.upstream.fallback,
+            vec!["tls://1.1.1.1#cloudflare-dns.com"]
+        );
+    }
+
+    #[test]
+    fn empty_address_gives_empty_vec() {
+        let config: Config = toml::from_str("").unwrap();
+        assert!(config.upstream.address.is_empty());
+        assert!(config.upstream.fallback.is_empty());
+    }
+
+    // ── [upstream] mode = "odoh" ────────────────────────────────────────
+
+    #[test]
+    fn odoh_config_parses_and_validates() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh-relay.numa.rs/relay"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert!(matches!(config.upstream.mode, UpstreamMode::Odoh));
+        let odoh = config.upstream.odoh_upstream().unwrap();
+        assert_eq!(odoh.relay_url, "https://odoh-relay.numa.rs/relay");
+        assert_eq!(odoh.target_host, "odoh.cloudflare-dns.com");
+        assert_eq!(odoh.target_path, "/dns-query");
+        assert!(odoh.strict, "strict defaults to true under mode=odoh");
+    }
+
+    #[test]
+    fn odoh_strict_false_is_honoured() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh-relay.numa.rs/relay"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+strict = false
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert!(!config.upstream.odoh_upstream().unwrap().strict);
+    }
+
+    #[test]
+    fn odoh_rejects_same_host_relay_and_target() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh.example.com/relay"
+target = "https://odoh.example.com/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let err = config.upstream.odoh_upstream().unwrap_err().to_string();
+        assert!(err.contains("same host"), "got: {err}");
+    }
+
+    #[test]
+    fn odoh_rejects_shared_registrable_domain() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://r.cloudflare.com/relay"
+target = "https://odoh.cloudflare.com/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let err = config.upstream.odoh_upstream().unwrap_err().to_string();
+        assert!(err.contains("registrable domain"), "got: {err}");
+        assert!(err.contains("cloudflare.com"), "got: {err}");
+    }
+
+    #[test]
+    fn odoh_rejects_shared_registrable_under_multi_label_suffix() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://a.foo.co.uk/relay"
+target = "https://b.foo.co.uk/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let err = config.upstream.odoh_upstream().unwrap_err().to_string();
+        assert!(err.contains("foo.co.uk"), "got: {err}");
+    }
+
+    #[test]
+    fn odoh_accepts_distinct_registrable_under_multi_label_suffix() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://relay.foo.co.uk/relay"
+target = "https://target.bar.co.uk/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert!(config.upstream.odoh_upstream().is_ok());
+    }
+
+    #[test]
+    fn odoh_accepts_distinct_private_psl_suffix_subdomains() {
+        // *.github.io is a public suffix, so foo.github.io and bar.github.io
+        // are independent registrable domains — accept.
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://foo.github.io/relay"
+target = "https://bar.github.io/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert!(config.upstream.odoh_upstream().is_ok());
+    }
+
+    #[test]
+    fn odoh_rejects_non_https() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "http://odoh-relay.numa.rs/relay"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let err = config.upstream.odoh_upstream().unwrap_err().to_string();
+        assert!(err.contains("https"), "got: {err}");
+    }
+
+    #[test]
+    fn odoh_missing_relay_rejected() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let err = config.upstream.odoh_upstream().unwrap_err().to_string();
+        assert!(err.contains("upstream.relay"), "got: {err}");
+    }
+
+    #[test]
+    fn odoh_bootstrap_ips_parse_into_socket_addrs() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh-relay.numa.rs/relay"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+relay_ip = "178.104.229.30"
+target_ip = "104.16.249.249"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let odoh = config.upstream.odoh_upstream().unwrap();
+        assert_eq!(odoh.relay_host, "odoh-relay.numa.rs");
+        assert_eq!(
+            odoh.relay_bootstrap.unwrap().to_string(),
+            "178.104.229.30:443"
+        );
+        assert_eq!(
+            odoh.target_bootstrap.unwrap().to_string(),
+            "104.16.249.249:443"
+        );
+    }
+
+    #[test]
+    fn odoh_bootstrap_ips_optional() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh-relay.numa.rs/relay"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let odoh = config.upstream.odoh_upstream().unwrap();
+        assert!(odoh.relay_bootstrap.is_none());
+        assert!(odoh.target_bootstrap.is_none());
+    }
+
+    #[test]
+    fn odoh_bootstrap_ip_rejects_garbage() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh-relay.numa.rs/relay"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+relay_ip = "not-an-ip"
+"#;
+        let err = toml::from_str::<Config>(toml).err().unwrap().to_string();
+        assert!(err.contains("relay_ip"), "got: {err}");
+    }
+
+    #[test]
+    fn odoh_bootstrap_uses_url_port_when_non_default() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh-relay.numa.rs:8443/relay"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+relay_ip = "178.104.229.30"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let odoh = config.upstream.odoh_upstream().unwrap();
+        assert_eq!(
+            odoh.relay_bootstrap.unwrap().to_string(),
+            "178.104.229.30:8443"
+        );
+    }
+
+    #[test]
+    fn hedge_delay_zeroed_for_odoh_mode() {
+        assert_eq!(
+            UpstreamMode::Odoh.hedge_delay(50),
+            Duration::ZERO,
+            "ODoH mode must zero hedge regardless of configured hedge_ms"
+        );
+        assert_eq!(
+            UpstreamMode::Forward.hedge_delay(50),
+            Duration::from_millis(50),
+            "non-ODoH modes honour configured hedge_ms"
+        );
+    }
+
+    #[test]
+    fn odoh_missing_target_rejected() {
+        let toml = r#"
+[upstream]
+mode = "odoh"
+relay = "https://odoh-relay.numa.rs/relay"
+"#;
+        let config: Config = toml::from_str(toml).unwrap();
+        let err = config.upstream.odoh_upstream().unwrap_err().to_string();
+        assert!(err.contains("upstream.target"), "got: {err}");
+    }
+
+    // ── issue #82: [[forwarding]] config section ────────────────────────
+
+    #[test]
+    fn forwarding_empty_by_default() {
+        let config: Config = toml::from_str("").unwrap();
+        assert!(config.forwarding.is_empty());
+    }
+
+    #[test]
+    fn forwarding_parses_single_rule() {
+        let toml = r#"
+            [[forwarding]]
+            suffix = "home.local"
+            upstream = "100.90.1.63:5361"
+        "#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert_eq!(config.forwarding.len(), 1);
+        assert_eq!(config.forwarding[0].suffix, &["home.local"]);
+        assert_eq!(config.forwarding[0].upstream, vec!["100.90.1.63:5361"]);
+    }
+
+    #[test]
+    fn forwarding_parses_reverse_dns_zone() {
+        let toml = r#"
+            [[forwarding]]
+            suffix = "168.192.in-addr.arpa"
+            upstream = "100.90.1.63:5361"
+        "#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert_eq!(config.forwarding.len(), 1);
+        assert_eq!(config.forwarding[0].suffix, &["168.192.in-addr.arpa"]);
+    }
+
+    #[test]
+    fn forwarding_parses_multiple_rules() {
+        let toml = r#"
+            [[forwarding]]
+            suffix = "168.192.in-addr.arpa"
+            upstream = "100.90.1.63:5361"
+
+            [[forwarding]]
+            suffix = "home.local"
+            upstream = "10.0.0.1"
+        "#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert_eq!(config.forwarding.len(), 2);
+        assert_eq!(config.forwarding[1].upstream, vec!["10.0.0.1"]);
+    }
+
+    #[test]
+    fn forwarding_parses_suffix_array() {
+        let toml = r#"
+            [[forwarding]]
+            suffix = ["168.192.in-addr.arpa", "onsite"]
+            upstream = "192.168.88.1"
+        "#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert_eq!(config.forwarding.len(), 1);
+        assert_eq!(
+            config.forwarding[0].suffix,
+            &["168.192.in-addr.arpa", "onsite"]
+        );
+    }
+
+    #[test]
+    fn forwarding_suffix_array_expands_to_multiple_runtime_rules() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["168.192.in-addr.arpa".to_string(), "onsite".to_string()],
+            upstream: vec!["192.168.88.1".to_string()],
+        };
+        let runtime = rule.to_runtime_rules().unwrap();
+        assert_eq!(runtime.len(), 2);
+        assert_eq!(runtime[0].suffix, "168.192.in-addr.arpa");
+        assert_eq!(runtime[1].suffix, "onsite");
+        assert_eq!(
+            runtime[0].upstream.preferred(),
+            runtime[1].upstream.preferred()
+        );
+    }
+
+    #[test]
+    fn forwarding_upstream_with_explicit_port() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["home.local".to_string()],
+            upstream: vec!["100.90.1.63:5361".to_string()],
+        };
+        let runtime = rule.to_runtime_rules().unwrap();
+        assert_eq!(runtime.len(), 1);
+        let preferred = runtime[0].upstream.preferred().unwrap();
+        assert!(matches!(preferred, crate::forward::Upstream::Udp(_)));
+        assert_eq!(preferred.to_string(), "100.90.1.63:5361");
+        assert_eq!(runtime[0].suffix, "home.local");
+    }
+
+    #[test]
+    fn forwarding_upstream_defaults_to_port_53() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["home.local".to_string()],
+            upstream: vec!["100.90.1.63".to_string()],
+        };
+        let runtime = rule.to_runtime_rules().unwrap();
+        assert_eq!(
+            runtime[0].upstream.preferred().unwrap().to_string(),
+            "100.90.1.63:53"
+        );
+    }
+
+    #[test]
+    fn forwarding_invalid_upstream_returns_error() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["home.local".to_string()],
+            upstream: vec!["not-a-valid-host".to_string()],
+        };
+        assert!(rule.to_runtime_rules().is_err());
+    }
+
+    #[test]
+    fn forwarding_upstream_accepts_dot_scheme() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["google.com".to_string()],
+            upstream: vec!["tls://9.9.9.9#dns.quad9.net".to_string()],
+        };
+        let runtime = rule
+            .to_runtime_rules()
+            .expect("tls:// upstream should parse");
+        assert_eq!(runtime.len(), 1);
+        assert_eq!(
+            runtime[0].upstream.preferred().unwrap().to_string(),
+            "tls://9.9.9.9:853#dns.quad9.net"
+        );
+    }
+
+    #[test]
+    fn forwarding_upstream_accepts_doh_scheme() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["goog".to_string()],
+            upstream: vec!["https://dns.quad9.net/dns-query".to_string()],
+        };
+        let runtime = rule
+            .to_runtime_rules()
+            .expect("https:// upstream should parse");
+        assert_eq!(runtime.len(), 1);
+        assert_eq!(
+            runtime[0].upstream.preferred().unwrap().to_string(),
+            "https://dns.quad9.net/dns-query"
+        );
+    }
+
+    #[test]
+    fn forwarding_config_rules_take_precedence_over_discovered() {
+        let config_rules = vec![ForwardingRuleConfig {
+            suffix: vec!["home.local".to_string()],
+            upstream: vec!["10.0.0.1:53".to_string()],
+        }];
+        let discovered = vec![crate::system_dns::ForwardingRule::new(
+            "home.local".to_string(),
+            crate::forward::UpstreamPool::new(
+                vec![crate::forward::Upstream::Udp(
+                    "192.168.1.1:53".parse().unwrap(),
+                )],
+                vec![],
+            ),
+        )];
+        let merged = merge_forwarding_rules(&config_rules, discovered).unwrap();
+        let picked = crate::system_dns::match_forwarding_rule("host.home.local", &merged)
+            .expect("rule should match");
+        assert_eq!(picked.preferred().unwrap().to_string(), "10.0.0.1:53");
+    }
+
+    #[test]
+    fn forwarding_merge_preserves_non_overlapping_discovered() {
+        let config_rules = vec![ForwardingRuleConfig {
+            suffix: vec!["home.local".to_string()],
+            upstream: vec!["10.0.0.1:53".to_string()],
+        }];
+        let discovered = vec![crate::system_dns::ForwardingRule::new(
+            "corp.example".to_string(),
+            crate::forward::UpstreamPool::new(
+                vec![crate::forward::Upstream::Udp(
+                    "192.168.1.1:53".parse().unwrap(),
+                )],
+                vec![],
+            ),
+        )];
+        let merged = merge_forwarding_rules(&config_rules, discovered).unwrap();
+        assert_eq!(merged.len(), 2);
+        let picked = crate::system_dns::match_forwarding_rule("host.corp.example", &merged)
+            .expect("discovered rule should still match");
+        assert_eq!(picked.preferred().unwrap().to_string(), "192.168.1.1:53");
+    }
+
+    #[test]
+    fn forwarding_merge_suffix_array_expands_to_multiple_rules() {
+        let config_rules = vec![ForwardingRuleConfig {
+            suffix: vec!["a.local".to_string(), "b.local".to_string()],
+            upstream: vec!["10.0.0.1:53".to_string()],
+        }];
+        let merged = merge_forwarding_rules(&config_rules, vec![]).unwrap();
+        assert_eq!(merged.len(), 2);
+    }
+
+    #[test]
+    fn forwarding_parses_upstream_array() {
+        let toml = r#"
+            [[forwarding]]
+            suffix = "google.com"
+            upstream = ["tls://9.9.9.9#dns.quad9.net", "tls://149.112.112.112#dns.quad9.net"]
+        "#;
+        let config: Config = toml::from_str(toml).unwrap();
+        assert_eq!(config.forwarding.len(), 1);
+        assert_eq!(config.forwarding[0].upstream.len(), 2);
+    }
+
+    #[test]
+    fn forwarding_upstream_array_builds_pool_with_multiple_primaries() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["google.com".to_string()],
+            upstream: vec![
+                "tls://9.9.9.9#dns.quad9.net".to_string(),
+                "tls://149.112.112.112#dns.quad9.net".to_string(),
+            ],
+        };
+        let runtime = rule.to_runtime_rules().unwrap();
+        assert_eq!(runtime.len(), 1);
+        let label = runtime[0].upstream.label();
+        assert!(label.contains("+1 more"), "label was: {}", label);
+    }
+
+    #[test]
+    fn forwarding_empty_upstream_array_errors() {
+        let rule = ForwardingRuleConfig {
+            suffix: vec!["home.local".to_string()],
+            upstream: vec![],
+        };
+        assert!(rule.to_runtime_rules().is_err());
+    }
 }
 
 pub struct ConfigLoad {
@@ -503,6 +1282,13 @@ pub fn load_config(path: &str) -> Result<ConfigLoad> {
             let filename = p.file_name().unwrap_or(p.as_os_str());
             v.push(crate::config_dir().join(filename));
             v.push(crate::data_dir().join(filename));
+            // Interactive root and sudo'd users: always consult the XDG path
+            // so `touch ~/.config/numa/numa.toml` works regardless of whether
+            // config_dir() routed to FHS (issue #81).
+            let suggested = crate::suggested_config_path();
+            if !v.contains(&suggested) {
+                v.push(suggested);
+            }
         }
         v
     };
@@ -523,11 +1309,7 @@ pub fn load_config(path: &str) -> Result<ConfigLoad> {
         }
     }
 
-    // Show config_dir candidate as the "expected" path — it's actionable
-    let display_path = candidates
-        .get(1)
-        .map(|p| p.to_string_lossy().to_string())
-        .unwrap_or_else(|| resolve_path(path));
+    let display_path = crate::suggested_config_path().to_string_lossy().to_string();
     log::info!("config not found, using defaults (create {})", display_path);
     Ok(ConfigLoad {
         config: Config::default(),

src/ctx.rs

@@ -1,7 +1,7 @@
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::net::SocketAddr;
 use std::path::PathBuf;
-use std::sync::{Mutex, RwLock};
+use std::sync::{Arc, Mutex, RwLock};
 use std::time::{Duration, Instant, SystemTime};
 
 use arc_swap::ArcSwap;
@@ -16,8 +16,11 @@ use crate::blocklist::BlocklistStore;
 use crate::buffer::BytePacketBuffer;
 use crate::cache::{DnsCache, DnssecStatus};
 use crate::config::{UpstreamMode, ZoneMap};
-use crate::forward::{forward_query, Upstream};
+#[cfg(test)]
+use crate::forward::Upstream;
+use crate::forward::{forward_with_failover_raw, UpstreamPool};
 use crate::header::ResultCode;
+use crate::health::HealthMeta;
 use crate::lan::PeerStore;
 use crate::override_store::OverrideStore;
 use crate::packet::DnsPacket;
@@ -26,7 +29,7 @@ use crate::question::QueryType;
 use crate::record::DnsRecord;
 use crate::service_store::ServiceStore;
 use crate::srtt::SrttCache;
-use crate::stats::{QueryPath, ServerStats};
+use crate::stats::{QueryPath, ServerStats, Transport};
 use crate::system_dns::ForwardingRule;
 
 pub struct ServerCtx {
@@ -34,6 +37,8 @@ pub struct ServerCtx {
     pub zone_map: ZoneMap,
     /// std::sync::RwLock (not tokio) — locks must never be held across .await points.
     pub cache: RwLock<DnsCache>,
+    /// Domains currently being refreshed in the background (dedup guard).
+    pub refreshing: Mutex<HashSet<(String, QueryType)>>,
     pub stats: Mutex<ServerStats>,
     pub overrides: RwLock<OverrideStore>,
     pub blocklist: RwLock<BlocklistStore>,
@@ -41,11 +46,12 @@ pub struct ServerCtx {
     pub services: Mutex<ServiceStore>,
     pub lan_peers: Mutex<PeerStore>,
     pub forwarding_rules: Vec<ForwardingRule>,
-    pub upstream: Mutex<Upstream>,
+    pub upstream_pool: Mutex<UpstreamPool>,
     pub upstream_auto: bool,
     pub upstream_port: u16,
     pub lan_ip: Mutex<std::net::Ipv4Addr>,
     pub timeout: Duration,
+    pub hedge_delay: Duration,
     pub proxy_tld: String,
     pub proxy_tld_suffix: String, // pre-computed ".{tld}" to avoid per-query allocation
     pub lan_enabled: bool,
@@ -60,6 +66,21 @@ pub struct ServerCtx {
     pub inflight: Mutex<InflightMap>,
     pub dnssec_enabled: bool,
     pub dnssec_strict: bool,
+    /// Cached health metadata (version, hostname, DoT config, CA
+    /// fingerprint, features). Shared between the main and mobile
+    /// API `/health` handlers. Built once at startup in `main.rs`.
+    pub health_meta: HealthMeta,
+    /// CA certificate in PEM form, cached at startup. `None` if no
+    /// TLS-using feature is enabled and the CA hasn't been generated.
+    /// Used by `/ca.pem`, `/mobileconfig`, and `/ca.mobileconfig`
+    /// handlers to avoid per-request disk I/O on the hot path.
+    pub ca_pem: Option<String>,
+    pub mobile_enabled: bool,
+    pub mobile_port: u16,
+    /// When true, AAAA queries short-circuit with NODATA (NOERROR + empty
+    /// answer) instead of hitting cache/forwarding/upstream. Local data
+    /// (overrides, zones, .numa proxy, blocklist sinkhole) is unaffected.
+    pub filter_aaaa: bool,
 }
 
 /// Transport-agnostic DNS resolution. Runs the full pipeline (overrides, blocklist,
@@ -69,9 +90,11 @@ pub struct ServerCtx {
 /// (and logging parse errors) before calling this function.
 pub async fn resolve_query(
     query: DnsPacket,
+    raw_wire: &[u8],
     src_addr: SocketAddr,
-    ctx: &ServerCtx,
-) -> crate::Result<BytePacketBuffer> {
+    ctx: &Arc<ServerCtx>,
+    transport: Transport,
+) -> crate::Result<(BytePacketBuffer, QueryPath)> {
     let start = Instant::now();
 
     let (qname, qtype) = match query.questions.first() {
@@ -79,8 +102,10 @@ pub async fn resolve_query(
         None => return Err("empty question section".into()),
     };
 
-    // Pipeline: overrides -> .tld interception -> blocklist -> local zones -> cache -> upstream
+    // Pipeline: overrides -> .localhost -> local zones -> special-use (unless forwarded)
+    //        -> .tld proxy -> blocklist -> cache -> forwarding -> recursive/upstream
     // Each lock is scoped to avoid holding MutexGuard across await points.
+    let mut upstream_transport: Option<crate::stats::UpstreamTransport> = None;
     let (response, path, dnssec) = {
         let override_record = ctx.overrides.read().unwrap().lookup(&qname);
         if let Some(record) = override_record {
@@ -98,8 +123,14 @@ pub async fn resolve_query(
                 300,
             ));
             (resp, QueryPath::Local, DnssecStatus::Indeterminate)
-        } else if is_special_use_domain(&qname) {
-            // RFC 6761/8880: private PTR, DDR, NAT64 — answer locally
+        } else if let Some(records) = ctx.zone_map.get(qname.as_str()).and_then(|m| m.get(&qtype)) {
+            let mut resp = DnsPacket::response_from(&query, ResultCode::NOERROR);
+            resp.answers = records.clone();
+            (resp, QueryPath::Local, DnssecStatus::Indeterminate)
+        } else if is_special_use_domain(&qname)
+            && crate::system_dns::match_forwarding_rule(&qname, &ctx.forwarding_rules).is_none()
+        {
+            // RFC 6761/8880: answer locally unless a forwarding rule covers this zone.
             let resp = special_use_response(&query, &qname, qtype);
             (resp, QueryPath::Local, DnssecStatus::Indeterminate)
         } else if !ctx.proxy_tld_suffix.is_empty()
@@ -146,30 +177,59 @@ pub async fn resolve_query(
                 60,
             ));
             (resp, QueryPath::Blocked, DnssecStatus::Indeterminate)
-        } else if let Some(records) = ctx.zone_map.get(qname.as_str()).and_then(|m| m.get(&qtype)) {
-            let mut resp = DnsPacket::response_from(&query, ResultCode::NOERROR);
-            resp.answers = records.clone();
+        } else if qtype == QueryType::AAAA && ctx.filter_aaaa {
+            // RFC 2308 NODATA: NOERROR with empty answer section. Prevents
+            // Happy Eyeballs clients from waiting on an AAAA they'll never use
+            // on IPv4-only networks. NXDOMAIN would be wrong (it'd imply the
+            // name doesn't exist for A either).
+            let resp = DnsPacket::response_from(&query, ResultCode::NOERROR);
             (resp, QueryPath::Local, DnssecStatus::Indeterminate)
         } else {
             let cached = ctx.cache.read().unwrap().lookup_with_status(&qname, qtype);
-            if let Some((cached, cached_dnssec)) = cached {
+            if let Some((cached, cached_dnssec, freshness)) = cached {
+                if freshness.needs_refresh() {
+                    let key = (qname.clone(), qtype);
+                    let already = !ctx.refreshing.lock().unwrap().insert(key.clone());
+                    if !already {
+                        let ctx = Arc::clone(ctx);
+                        tokio::spawn(async move {
+                            refresh_entry(&ctx, &key.0, key.1).await;
+                            ctx.refreshing.lock().unwrap().remove(&key);
+                        });
+                    }
+                }
                 let mut resp = cached;
                 resp.header.id = query.header.id;
                 if cached_dnssec == DnssecStatus::Secure {
                     resp.header.authed_data = true;
                 }
                 (resp, QueryPath::Cached, cached_dnssec)
-            } else if let Some(fwd_addr) =
+            } else if let Some(pool) =
                 crate::system_dns::match_forwarding_rule(&qname, &ctx.forwarding_rules)
             {
                 // Conditional forwarding takes priority over recursive mode
                 // (e.g. Tailscale .ts.net, VPC private zones)
-                let upstream = Upstream::Udp(fwd_addr);
-                match forward_query(&query, &upstream, ctx.timeout).await {
-                    Ok(resp) => {
-                        ctx.cache.write().unwrap().insert(&qname, qtype, &resp);
-                        (resp, QueryPath::Forwarded, DnssecStatus::Indeterminate)
-                    }
+                upstream_transport = pool.preferred().map(|u| u.transport());
+                match forward_with_failover_raw(
+                    raw_wire,
+                    pool,
+                    &ctx.srtt,
+                    ctx.timeout,
+                    ctx.hedge_delay,
+                )
+                .await
+                {
+                    Ok(resp_wire) => match cache_and_parse(ctx, &qname, qtype, &resp_wire) {
+                        Ok(resp) => (resp, QueryPath::Forwarded, DnssecStatus::Indeterminate),
+                        Err(e) => {
+                            error!("{} | {:?} {} | PARSE ERROR | {}", src_addr, qtype, qname, e);
+                            (
+                                DnsPacket::response_from(&query, ResultCode::SERVFAIL),
+                                QueryPath::UpstreamError,
+                                DnssecStatus::Indeterminate,
+                            )
+                        }
+                    },
                     Err(e) => {
                         error!(
                             "{} | {:?} {} | FORWARD ERROR | {}",
@@ -183,6 +243,9 @@ pub async fn resolve_query(
                     }
                 }
             } else if ctx.upstream_mode == UpstreamMode::Recursive {
+                // Recursive resolution makes UDP hops to roots/TLDs/auths;
+                // tag as Udp so the dashboard can aggregate plaintext-wire
+                // egress honestly. Only mark on success — errors stay None.
                 let key = (qname.clone(), qtype);
                 let (resp, path, err) = resolve_coalesced(&ctx.inflight, key, &query, || {
                     crate::recursive::resolve_recursive(
@@ -205,19 +268,35 @@ pub async fn resolve_query(
                         qname,
                         err.as_deref().unwrap_or("leader failed")
                     );
+                } else {
+                    upstream_transport = Some(crate::stats::UpstreamTransport::Udp);
                 }
                 (resp, path, DnssecStatus::Indeterminate)
             } else {
-                let upstream =
-                    match crate::system_dns::match_forwarding_rule(&qname, &ctx.forwarding_rules) {
-                        Some(addr) => Upstream::Udp(addr),
-                        None => ctx.upstream.lock().unwrap().clone(),
-                    };
-                match forward_query(&query, &upstream, ctx.timeout).await {
-                    Ok(resp) => {
-                        ctx.cache.write().unwrap().insert(&qname, qtype, &resp);
-                        (resp, QueryPath::Forwarded, DnssecStatus::Indeterminate)
-                    }
+                let pool = ctx.upstream_pool.lock().unwrap().clone();
+                match forward_with_failover_raw(
+                    raw_wire,
+                    &pool,
+                    &ctx.srtt,
+                    ctx.timeout,
+                    ctx.hedge_delay,
+                )
+                .await
+                {
+                    Ok(resp_wire) => match cache_and_parse(ctx, &qname, qtype, &resp_wire) {
+                        Ok(resp) => {
+                            upstream_transport = pool.preferred().map(|u| u.transport());
+                            (resp, QueryPath::Upstream, DnssecStatus::Indeterminate)
+                        }
+                        Err(e) => {
+                            error!("{} | {:?} {} | PARSE ERROR | {}", src_addr, qtype, qname, e);
+                            (
+                                DnsPacket::response_from(&query, ResultCode::SERVFAIL),
+                                QueryPath::UpstreamError,
+                                DnssecStatus::Indeterminate,
+                            )
+                        }
+                    },
                     Err(e) => {
                         error!(
                             "{} | {:?} {} | UPSTREAM ERROR | {}",
@@ -276,6 +355,15 @@ pub async fn resolve_query(
         strip_dnssec_records(&mut response);
     }
 
+    // filter_aaaa: also strip ipv6hint from HTTPS/SVCB answers so modern
+    // browsers (Chrome ≥103 etc.) don't receive v6 address hints via the
+    // HTTPS record path that bypasses AAAA entirely. Gated on !client_do
+    // because modifying rdata invalidates any accompanying RRSIG — a DO-bit
+    // validator downstream would reject the response as Bogus.
+    if ctx.filter_aaaa && !client_do {
+        strip_svcb_ipv6_hints(&mut response);
+    }
+
     // Echo EDNS back if client sent it
     if query.edns.is_some() {
         response.edns = Some(crate::packet::EdnsOpt {
@@ -319,7 +407,7 @@ pub async fn resolve_query(
     // Record stats and query log
     {
         let mut s = ctx.stats.lock().unwrap();
-        let total = s.record(path);
+        let total = s.record(path, transport, upstream_transport);
         if total.is_multiple_of(1000) {
             s.log_summary();
         }
@@ -331,19 +419,76 @@ pub async fn resolve_query(
         domain: qname,
         query_type: qtype,
         path,
+        transport,
         rescode: response.header.rescode,
         latency_us: elapsed.as_micros() as u64,
         dnssec,
     });
 
-    Ok(resp_buffer)
+    Ok((resp_buffer, path))
+}
+
+fn cache_and_parse(
+    ctx: &ServerCtx,
+    qname: &str,
+    qtype: QueryType,
+    resp_wire: &[u8],
+) -> crate::Result<DnsPacket> {
+    ctx.cache
+        .write()
+        .unwrap()
+        .insert_wire(qname, qtype, resp_wire, DnssecStatus::Indeterminate);
+    let mut buf = BytePacketBuffer::from_bytes(resp_wire);
+    DnsPacket::from_buffer(&mut buf)
+}
+
+/// Re-resolve a single (domain, qtype) and update the cache.
+/// Used for both stale-entry refresh and proactive cache warming.
+pub async fn refresh_entry(ctx: &ServerCtx, qname: &str, qtype: QueryType) {
+    let query = DnsPacket::query(0, qname, qtype);
+    if ctx.upstream_mode == UpstreamMode::Recursive {
+        if let Ok(resp) = crate::recursive::resolve_recursive(
+            qname,
+            qtype,
+            &ctx.cache,
+            &query,
+            &ctx.root_hints,
+            &ctx.srtt,
+        )
+        .await
+        {
+            ctx.cache.write().unwrap().insert(qname, qtype, &resp);
+        }
+    } else {
+        let mut buf = BytePacketBuffer::new();
+        if query.write(&mut buf).is_ok() {
+            let pool = ctx.upstream_pool.lock().unwrap().clone();
+            if let Ok(wire) = forward_with_failover_raw(
+                buf.filled(),
+                &pool,
+                &ctx.srtt,
+                ctx.timeout,
+                ctx.hedge_delay,
+            )
+            .await
+            {
+                ctx.cache.write().unwrap().insert_wire(
+                    qname,
+                    qtype,
+                    &wire,
+                    DnssecStatus::Indeterminate,
+                );
+            }
+        }
+    }
 }
 
-/// Handle a DNS query received over UDP. Thin wrapper around resolve_query.
 pub async fn handle_query(
     mut buffer: BytePacketBuffer,
+    raw_len: usize,
     src_addr: SocketAddr,
-    ctx: &ServerCtx,
+    ctx: &Arc<ServerCtx>,
+    transport: Transport,
 ) -> crate::Result<()> {
     let query = match DnsPacket::from_buffer(&mut buffer) {
         Ok(packet) => packet,
@@ -352,8 +497,8 @@ pub async fn handle_query(
             return Ok(());
         }
     };
-    match resolve_query(query, src_addr, ctx).await {
-        Ok(resp_buffer) => {
+    match resolve_query(query, &buffer.buf[..raw_len], src_addr, ctx, transport).await {
+        Ok((resp_buffer, _)) => {
             ctx.socket.send_to(resp_buffer.filled(), src_addr).await?;
         }
         Err(e) => {
@@ -376,6 +521,20 @@ fn strip_dnssec_records(pkt: &mut DnsPacket) {
     pkt.resources.retain(|r| !is_dnssec_record(r));
 }
 
+fn strip_svcb_ipv6_hints(pkt: &mut DnsPacket) {
+    let https_qtype = QueryType::HTTPS.to_num();
+    let svcb_qtype = QueryType::SVCB.to_num();
+    pkt.for_each_record_mut(|rec| {
+        if let DnsRecord::UNKNOWN { qtype, data, .. } = rec {
+            if *qtype == https_qtype || *qtype == svcb_qtype {
+                if let Some(new_data) = crate::svcb::strip_ipv6hint(data) {
+                    *data = new_data;
+                }
+            }
+        }
+    });
+}
+
 fn is_special_use_domain(qname: &str) -> bool {
     if qname.ends_with(".in-addr.arpa") {
         // RFC 6303: private + loopback + link-local reverse DNS
@@ -932,4 +1091,470 @@ mod tests {
             "error message must be preserved for logging"
         );
     }
+
+    // ---- Full-pipeline resolve_query tests ----
+
+    /// Send a query through the full resolve_query pipeline and return
+    /// the parsed response + query path.
+    async fn resolve_in_test(
+        ctx: &Arc<ServerCtx>,
+        domain: &str,
+        qtype: QueryType,
+    ) -> (DnsPacket, QueryPath) {
+        let query = DnsPacket::query(0xBEEF, domain, qtype);
+        let mut buf = BytePacketBuffer::new();
+        query.write(&mut buf).unwrap();
+        let raw = &buf.buf[..buf.pos];
+        let src: SocketAddr = "127.0.0.1:1234".parse().unwrap();
+
+        let (resp_buf, path) = resolve_query(query, raw, src, ctx, Transport::Udp)
+            .await
+            .unwrap();
+
+        let mut resp_parse_buf = BytePacketBuffer::from_bytes(resp_buf.filled());
+        let resp = DnsPacket::from_buffer(&mut resp_parse_buf).unwrap();
+        (resp, path)
+    }
+
+    #[tokio::test]
+    async fn special_use_private_ptr_returns_nxdomain() {
+        let ctx = Arc::new(crate::testutil::test_ctx().await);
+        let (resp, path) =
+            resolve_in_test(&ctx, "153.188.168.192.in-addr.arpa", QueryType::PTR).await;
+        assert_eq!(path, QueryPath::Local);
+        assert_eq!(resp.header.rescode, ResultCode::NXDOMAIN);
+    }
+
+    #[tokio::test]
+    async fn forwarding_rule_overrides_special_use_domain() {
+        let mut resp = DnsPacket::new();
+        resp.header.response = true;
+        resp.header.rescode = ResultCode::NOERROR;
+        let upstream_addr = crate::testutil::mock_upstream(resp).await;
+
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.forwarding_rules = vec![ForwardingRule::new(
+            "168.192.in-addr.arpa".to_string(),
+            UpstreamPool::new(vec![Upstream::Udp(upstream_addr)], vec![]),
+        )];
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) =
+            resolve_in_test(&ctx, "153.188.168.192.in-addr.arpa", QueryType::PTR).await;
+
+        assert_eq!(
+            path,
+            QueryPath::Forwarded,
+            "forwarding rule must take precedence over special-use NXDOMAIN"
+        );
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+    }
+
+    #[tokio::test]
+    async fn pipeline_override_takes_precedence() {
+        let ctx = crate::testutil::test_ctx().await;
+        ctx.overrides
+            .write()
+            .unwrap()
+            .insert("override.test", "1.2.3.4", 60, None)
+            .unwrap();
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "override.test", QueryType::A).await;
+        assert_eq!(path, QueryPath::Overridden);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        assert_eq!(resp.answers.len(), 1);
+    }
+
+    #[tokio::test]
+    async fn pipeline_localhost_resolves_to_loopback() {
+        let ctx = Arc::new(crate::testutil::test_ctx().await);
+
+        let (resp, path) = resolve_in_test(&ctx, "localhost", QueryType::A).await;
+        assert_eq!(path, QueryPath::Local);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        match &resp.answers[0] {
+            DnsRecord::A { addr, .. } => assert_eq!(*addr, Ipv4Addr::LOCALHOST),
+            other => panic!("expected A record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_localhost_subdomain_resolves_to_loopback() {
+        let ctx = Arc::new(crate::testutil::test_ctx().await);
+
+        let (resp, path) = resolve_in_test(&ctx, "app.localhost", QueryType::A).await;
+        assert_eq!(path, QueryPath::Local);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        match &resp.answers[0] {
+            DnsRecord::A { addr, .. } => assert_eq!(*addr, Ipv4Addr::LOCALHOST),
+            other => panic!("expected A record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_local_zone_returns_configured_record() {
+        let mut ctx = crate::testutil::test_ctx().await;
+        let mut inner = HashMap::new();
+        inner.insert(
+            QueryType::A,
+            vec![DnsRecord::A {
+                domain: "myapp.test".to_string(),
+                addr: Ipv4Addr::new(10, 0, 0, 42),
+                ttl: 300,
+            }],
+        );
+        ctx.zone_map.insert("myapp.test".to_string(), inner);
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "myapp.test", QueryType::A).await;
+        assert_eq!(path, QueryPath::Local);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        match &resp.answers[0] {
+            DnsRecord::A { addr, .. } => assert_eq!(*addr, Ipv4Addr::new(10, 0, 0, 42)),
+            other => panic!("expected A record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_tld_proxy_resolves_service() {
+        let ctx = crate::testutil::test_ctx().await;
+        ctx.services.lock().unwrap().insert("grafana", 3000);
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "grafana.numa", QueryType::A).await;
+        assert_eq!(path, QueryPath::Local);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        match &resp.answers[0] {
+            DnsRecord::A { addr, .. } => assert_eq!(*addr, Ipv4Addr::LOCALHOST),
+            other => panic!("expected A record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_filter_aaaa_returns_nodata() {
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.filter_aaaa = true;
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "example.com", QueryType::AAAA).await;
+        assert_eq!(path, QueryPath::Local);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        assert!(resp.answers.is_empty(), "AAAA must be filtered to NODATA");
+    }
+
+    #[tokio::test]
+    async fn pipeline_filter_aaaa_leaves_a_queries_alone() {
+        let mut upstream_resp = DnsPacket::new();
+        upstream_resp.header.response = true;
+        upstream_resp.header.rescode = ResultCode::NOERROR;
+        upstream_resp.answers.push(DnsRecord::A {
+            domain: "example.com".to_string(),
+            addr: Ipv4Addr::new(93, 184, 216, 34),
+            ttl: 300,
+        });
+        let upstream_addr = crate::testutil::mock_upstream(upstream_resp).await;
+
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.filter_aaaa = true;
+        ctx.upstream_pool
+            .lock()
+            .unwrap()
+            .set_primary(vec![Upstream::Udp(upstream_addr)]);
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "example.com", QueryType::A).await;
+        assert_eq!(path, QueryPath::Upstream);
+        assert_eq!(resp.answers.len(), 1);
+    }
+
+    #[tokio::test]
+    async fn pipeline_filter_aaaa_respects_override() {
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.filter_aaaa = true;
+        ctx.overrides
+            .write()
+            .unwrap()
+            .insert("v6.test", "2001:db8::1", 60, None)
+            .unwrap();
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "v6.test", QueryType::AAAA).await;
+        assert_eq!(path, QueryPath::Overridden);
+        assert_eq!(resp.answers.len(), 1, "override must win over filter");
+    }
+
+    #[tokio::test]
+    async fn pipeline_filter_aaaa_strips_ipv6hint_from_https_and_svcb() {
+        let rdata = crate::svcb::build_rdata(
+            1,
+            &[],
+            &[
+                (1, vec![0x02, b'h', b'3']),
+                (
+                    6,
+                    vec![
+                        0x26, 0x06, 0x47, 0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01,
+                    ],
+                ),
+            ],
+        );
+
+        let mut pkt = DnsPacket::new();
+        pkt.header.response = true;
+        pkt.header.rescode = ResultCode::NOERROR;
+        pkt.questions.push(crate::question::DnsQuestion {
+            name: "hints.test".to_string(),
+            qtype: QueryType::HTTPS,
+        });
+        pkt.answers.push(DnsRecord::UNKNOWN {
+            domain: "hints.test".to_string(),
+            qtype: 65,
+            data: rdata.clone(),
+            ttl: 300,
+        });
+
+        let mut svcb_pkt = pkt.clone();
+        svcb_pkt.questions[0].name = "svc.test".to_string();
+        svcb_pkt.questions[0].qtype = QueryType::SVCB;
+        if let DnsRecord::UNKNOWN { domain, qtype, .. } = &mut svcb_pkt.answers[0] {
+            *domain = "svc.test".to_string();
+            *qtype = 64;
+        }
+
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.filter_aaaa = true;
+        ctx.cache
+            .write()
+            .unwrap()
+            .insert("hints.test", QueryType::HTTPS, &pkt);
+        ctx.cache
+            .write()
+            .unwrap()
+            .insert("svc.test", QueryType::SVCB, &svcb_pkt);
+        let ctx = Arc::new(ctx);
+
+        for (name, qtype, label) in [
+            ("hints.test", QueryType::HTTPS, "HTTPS"),
+            ("svc.test", QueryType::SVCB, "SVCB"),
+        ] {
+            let (resp, path) = resolve_in_test(&ctx, name, qtype).await;
+            assert_eq!(path, QueryPath::Cached, "{label}");
+            assert_eq!(resp.answers.len(), 1, "{label}");
+            match &resp.answers[0] {
+                DnsRecord::UNKNOWN { data, .. } => {
+                    assert!(
+                        data.len() < rdata.len(),
+                        "{label}: ipv6hint (20 bytes) must be removed"
+                    );
+                    // Bytes for key=6 must not appear at any 4-byte boundary in the
+                    // params section — cheap structural check.
+                    assert!(
+                        !data.windows(4).any(|w| w == [0, 6, 0, 16]),
+                        "{label}: ipv6hint TLV header must be absent"
+                    );
+                }
+                other => panic!("{label}: expected UNKNOWN record, got {other:?}"),
+            }
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_filter_aaaa_preserves_ipv6hint_for_dnssec_clients() {
+        // Regression guard for the DO-bit gate in resolve_query: modifying
+        // HTTPS rdata invalidates any accompanying RRSIG, so a DO=1 client
+        // must receive the record untouched even when filter_aaaa is on.
+        let rdata = crate::svcb::build_rdata(
+            1,
+            &[],
+            &[(
+                6,
+                vec![
+                    0x26, 0x06, 0x47, 0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01,
+                ],
+            )],
+        );
+
+        let mut pkt = DnsPacket::new();
+        pkt.header.response = true;
+        pkt.header.rescode = ResultCode::NOERROR;
+        pkt.questions.push(crate::question::DnsQuestion {
+            name: "hints.test".to_string(),
+            qtype: QueryType::HTTPS,
+        });
+        pkt.answers.push(DnsRecord::UNKNOWN {
+            domain: "hints.test".to_string(),
+            qtype: 65,
+            data: rdata.clone(),
+            ttl: 300,
+        });
+
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.filter_aaaa = true;
+        ctx.cache
+            .write()
+            .unwrap()
+            .insert("hints.test", QueryType::HTTPS, &pkt);
+        let ctx = Arc::new(ctx);
+
+        // Build a query with EDNS DO bit set — can't use resolve_in_test
+        // because it constructs a plain query without EDNS.
+        let mut query = DnsPacket::query(0xBEEF, "hints.test", QueryType::HTTPS);
+        query.edns = Some(crate::packet::EdnsOpt {
+            do_bit: true,
+            ..Default::default()
+        });
+        let mut buf = BytePacketBuffer::new();
+        query.write(&mut buf).unwrap();
+        let raw = &buf.buf[..buf.pos];
+        let src: SocketAddr = "127.0.0.1:1234".parse().unwrap();
+
+        let (resp_buf, _) = resolve_query(query, raw, src, &ctx, Transport::Udp)
+            .await
+            .unwrap();
+        let mut resp_parse_buf = BytePacketBuffer::from_bytes(resp_buf.filled());
+        let resp = DnsPacket::from_buffer(&mut resp_parse_buf).unwrap();
+
+        match &resp.answers[0] {
+            DnsRecord::UNKNOWN { data, .. } => {
+                assert_eq!(
+                    data, &rdata,
+                    "ipv6hint must be preserved for DO-bit clients"
+                );
+            }
+            other => panic!("expected UNKNOWN record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_blocklist_sinkhole() {
+        let ctx = crate::testutil::test_ctx().await;
+        let mut domains = std::collections::HashSet::new();
+        domains.insert("ads.tracker.test".to_string());
+        ctx.blocklist.write().unwrap().swap_domains(domains, vec![]);
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "ads.tracker.test", QueryType::A).await;
+        assert_eq!(path, QueryPath::Blocked);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        match &resp.answers[0] {
+            DnsRecord::A { addr, .. } => assert_eq!(*addr, Ipv4Addr::UNSPECIFIED),
+            other => panic!("expected sinkhole A record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_cache_hit() {
+        let ctx = Arc::new(crate::testutil::test_ctx().await);
+
+        // Pre-populate cache with a response
+        let mut pkt = DnsPacket::new();
+        pkt.header.response = true;
+        pkt.header.rescode = ResultCode::NOERROR;
+        pkt.questions.push(crate::question::DnsQuestion {
+            name: "cached.test".to_string(),
+            qtype: QueryType::A,
+        });
+        pkt.answers.push(DnsRecord::A {
+            domain: "cached.test".to_string(),
+            addr: Ipv4Addr::new(5, 5, 5, 5),
+            ttl: 3600,
+        });
+        ctx.cache
+            .write()
+            .unwrap()
+            .insert("cached.test", QueryType::A, &pkt);
+
+        let (resp, path) = resolve_in_test(&ctx, "cached.test", QueryType::A).await;
+        assert_eq!(path, QueryPath::Cached);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+    }
+
+    #[tokio::test]
+    async fn pipeline_forwarding_returns_upstream_answer() {
+        let mut upstream_resp = DnsPacket::new();
+        upstream_resp.header.response = true;
+        upstream_resp.header.rescode = ResultCode::NOERROR;
+        upstream_resp.answers.push(DnsRecord::A {
+            domain: "internal.corp".to_string(),
+            addr: Ipv4Addr::new(10, 1, 2, 3),
+            ttl: 600,
+        });
+        let upstream_addr = crate::testutil::mock_upstream(upstream_resp).await;
+
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.forwarding_rules = vec![ForwardingRule::new(
+            "corp".to_string(),
+            UpstreamPool::new(vec![Upstream::Udp(upstream_addr)], vec![]),
+        )];
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "internal.corp", QueryType::A).await;
+        assert_eq!(path, QueryPath::Forwarded);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        assert_eq!(resp.answers.len(), 1);
+        match &resp.answers[0] {
+            DnsRecord::A { domain, addr, .. } => {
+                assert_eq!(domain, "internal.corp");
+                assert_eq!(*addr, Ipv4Addr::new(10, 1, 2, 3));
+            }
+            other => panic!("expected A record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_forwarding_fails_over_to_second_upstream() {
+        let dead = crate::testutil::blackhole_upstream();
+
+        let mut live_resp = DnsPacket::new();
+        live_resp.header.response = true;
+        live_resp.header.rescode = ResultCode::NOERROR;
+        live_resp.answers.push(DnsRecord::A {
+            domain: "internal.corp".to_string(),
+            addr: Ipv4Addr::new(10, 9, 9, 9),
+            ttl: 600,
+        });
+        let live = crate::testutil::mock_upstream(live_resp).await;
+
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.forwarding_rules = vec![ForwardingRule::new(
+            "corp".to_string(),
+            UpstreamPool::new(vec![Upstream::Udp(dead), Upstream::Udp(live)], vec![]),
+        )];
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "internal.corp", QueryType::A).await;
+        assert_eq!(path, QueryPath::Forwarded);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        assert_eq!(resp.answers.len(), 1);
+        match &resp.answers[0] {
+            DnsRecord::A { addr, .. } => assert_eq!(*addr, Ipv4Addr::new(10, 9, 9, 9)),
+            other => panic!("expected A record, got {:?}", other),
+        }
+    }
+
+    #[tokio::test]
+    async fn pipeline_default_pool_reports_upstream_path() {
+        let mut upstream_resp = DnsPacket::new();
+        upstream_resp.header.response = true;
+        upstream_resp.header.rescode = ResultCode::NOERROR;
+        upstream_resp.answers.push(DnsRecord::A {
+            domain: "example.com".to_string(),
+            addr: Ipv4Addr::new(93, 184, 216, 34),
+            ttl: 300,
+        });
+        let upstream_addr = crate::testutil::mock_upstream(upstream_resp).await;
+
+        let ctx = crate::testutil::test_ctx().await;
+        ctx.upstream_pool
+            .lock()
+            .unwrap()
+            .set_primary(vec![Upstream::Udp(upstream_addr)]);
+        let ctx = Arc::new(ctx);
+
+        let (resp, path) = resolve_in_test(&ctx, "example.com", QueryType::A).await;
+        assert_eq!(path, QueryPath::Upstream);
+        assert_eq!(resp.header.rescode, ResultCode::NOERROR);
+        assert_eq!(resp.answers.len(), 1);
+    }
 }

src/doh.rs

@@ -0,0 +1,224 @@
+use std::net::SocketAddr;
+
+use axum::body::Bytes;
+use axum::extract::{Request, State};
+use axum::response::{IntoResponse, Response};
+use hyper::StatusCode;
+use log::warn;
+
+use crate::buffer::BytePacketBuffer;
+use crate::ctx::{resolve_query, ServerCtx};
+use crate::header::ResultCode;
+use crate::packet::DnsPacket;
+use crate::stats::Transport;
+
+const MAX_DNS_MSG: usize = 4096;
+const DOH_CONTENT_TYPE: &str = "application/dns-message";
+
+pub async fn doh_post(State(state): State<super::proxy::DohState>, req: Request) -> Response {
+    let host = super::proxy::extract_host(&req);
+    if !is_doh_host(host.as_deref(), &state.ctx.proxy_tld) {
+        return StatusCode::NOT_FOUND.into_response();
+    }
+
+    let content_type = req
+        .headers()
+        .get(hyper::header::CONTENT_TYPE)
+        .and_then(|v| v.to_str().ok())
+        .unwrap_or("");
+    if !content_type.starts_with(DOH_CONTENT_TYPE) {
+        return StatusCode::UNSUPPORTED_MEDIA_TYPE.into_response();
+    }
+
+    let body = match axum::body::to_bytes(req.into_body(), MAX_DNS_MSG).await {
+        Ok(b) => b,
+        Err(_) => {
+            return (StatusCode::PAYLOAD_TOO_LARGE, "body exceeds 4096 bytes").into_response()
+        }
+    };
+
+    if body.is_empty() {
+        return (StatusCode::BAD_REQUEST, "empty body").into_response();
+    }
+
+    let src = state
+        .remote_addr
+        .unwrap_or_else(|| SocketAddr::from(([127, 0, 0, 1], 0)));
+
+    resolve_doh(&body, src, &state.ctx).await
+}
+
+fn is_doh_host(host: Option<&str>, tld: &str) -> bool {
+    let h = match host {
+        Some(h) => h,
+        None => return false,
+    };
+    let base = strip_port(h).unwrap_or(h);
+    is_loopback_host(base) || is_tld_match(base, tld)
+}
+
+fn strip_port(h: &str) -> Option<&str> {
+    if h.starts_with('[') {
+        // [::1]:443 → [::1]
+        let (base, port) = h.rsplit_once("]:")?;
+        port.bytes()
+            .all(|b| b.is_ascii_digit())
+            .then(|| &h[..base.len() + 1])
+    } else {
+        let (base, port) = h.rsplit_once(':')?;
+        // Bare IPv6 like "::1" has multiple colons — not a port suffix
+        if base.contains(':') {
+            return None;
+        }
+        port.bytes().all(|b| b.is_ascii_digit()).then_some(base)
+    }
+}
+
+fn is_loopback_host(h: &str) -> bool {
+    matches!(h, "127.0.0.1" | "::1" | "[::1]" | "localhost")
+}
+
+fn is_tld_match(h: &str, tld: &str) -> bool {
+    h == tld
+        || (h.len() == 2 * tld.len() + 1
+            && h.starts_with(tld)
+            && h.as_bytes().get(tld.len()) == Some(&b'.')
+            && h.ends_with(tld))
+}
+
+async fn resolve_doh(
+    dns_bytes: &[u8],
+    src: SocketAddr,
+    ctx: &std::sync::Arc<ServerCtx>,
+) -> Response {
+    let mut buffer = BytePacketBuffer::from_bytes(dns_bytes);
+    let query = match DnsPacket::from_buffer(&mut buffer) {
+        Ok(q) => q,
+        Err(e) => {
+            warn!("DoH: parse error from {}: {}", src, e);
+            let query_id = u16::from_be_bytes([
+                dns_bytes.first().copied().unwrap_or(0),
+                dns_bytes.get(1).copied().unwrap_or(0),
+            ]);
+            let mut resp = DnsPacket::new();
+            resp.header.id = query_id;
+            resp.header.response = true;
+            resp.header.rescode = ResultCode::FORMERR;
+            return serialize_response(&resp);
+        }
+    };
+
+    let query_id = query.header.id;
+    let query_rd = query.header.recursion_desired;
+    let questions = query.questions.clone();
+
+    match resolve_query(query, dns_bytes, src, ctx, Transport::Doh).await {
+        Ok((resp_buffer, _)) => {
+            let min_ttl = extract_min_ttl(resp_buffer.filled());
+            dns_response(resp_buffer.filled(), min_ttl)
+        }
+        Err(e) => {
+            warn!("DoH: resolve error for {}: {}", src, e);
+            let mut resp = DnsPacket::new();
+            resp.header.id = query_id;
+            resp.header.response = true;
+            resp.header.recursion_desired = query_rd;
+            resp.header.recursion_available = true;
+            resp.header.rescode = ResultCode::SERVFAIL;
+            resp.questions = questions;
+            serialize_response(&resp)
+        }
+    }
+}
+
+fn extract_min_ttl(wire: &[u8]) -> u32 {
+    crate::wire::scan_ttl_offsets(wire)
+        .ok()
+        .and_then(|meta| crate::wire::min_ttl_from_wire(wire, &meta))
+        .unwrap_or(0)
+}
+
+fn dns_response(wire: &[u8], min_ttl: u32) -> Response {
+    (
+        StatusCode::OK,
+        [
+            (hyper::header::CONTENT_TYPE, DOH_CONTENT_TYPE),
+            (
+                hyper::header::CACHE_CONTROL,
+                &format!("max-age={}", min_ttl),
+            ),
+        ],
+        Bytes::copy_from_slice(wire),
+    )
+        .into_response()
+}
+
+fn serialize_response(pkt: &DnsPacket) -> Response {
+    let mut buf = BytePacketBuffer::new();
+    match pkt.write(&mut buf) {
+        Ok(_) => dns_response(buf.filled(), 0),
+        Err(_) => StatusCode::INTERNAL_SERVER_ERROR.into_response(),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::buffer::BytePacketBuffer;
+    use crate::header::ResultCode;
+    use crate::packet::DnsPacket;
+    use crate::record::DnsRecord;
+
+    #[test]
+    fn is_doh_host_matches_tld() {
+        assert!(is_doh_host(Some("numa"), "numa"));
+        assert!(is_doh_host(Some("numa.numa"), "numa"));
+        assert!(is_doh_host(Some("127.0.0.1"), "numa"));
+        assert!(is_doh_host(Some("127.0.0.1:443"), "numa"));
+        assert!(is_doh_host(Some("::1"), "numa"));
+        assert!(is_doh_host(Some("[::1]"), "numa"));
+        assert!(is_doh_host(Some("[::1]:443"), "numa"));
+        assert!(is_doh_host(Some("localhost"), "numa"));
+        assert!(is_doh_host(Some("localhost:443"), "numa"));
+        assert!(!is_doh_host(Some("foo.numa"), "numa"));
+        assert!(!is_doh_host(None, "numa"));
+    }
+
+    #[test]
+    fn extract_min_ttl_from_response() {
+        let mut pkt = DnsPacket::new();
+        pkt.header.response = true;
+        pkt.answers.push(DnsRecord::A {
+            domain: "example.com".to_string(),
+            addr: std::net::Ipv4Addr::new(1, 2, 3, 4),
+            ttl: 300,
+        });
+        pkt.answers.push(DnsRecord::A {
+            domain: "example.com".to_string(),
+            addr: std::net::Ipv4Addr::new(5, 6, 7, 8),
+            ttl: 60,
+        });
+        let mut buf = BytePacketBuffer::new();
+        pkt.write(&mut buf).unwrap();
+        assert_eq!(extract_min_ttl(buf.filled()), 60);
+    }
+
+    #[test]
+    fn extract_min_ttl_no_answers() {
+        let mut pkt = DnsPacket::new();
+        pkt.header.response = true;
+        let mut buf = BytePacketBuffer::new();
+        pkt.write(&mut buf).unwrap();
+        assert_eq!(extract_min_ttl(buf.filled()), 0);
+    }
+
+    #[test]
+    fn serialize_formerr_response() {
+        let mut pkt = DnsPacket::new();
+        pkt.header.id = 0xABCD;
+        pkt.header.response = true;
+        pkt.header.rescode = ResultCode::FORMERR;
+        let resp = serialize_response(&pkt);
+        assert_eq!(resp.status(), StatusCode::OK);
+    }
+}

src/dot.rs

@@ -15,6 +15,7 @@ use crate::config::DotConfig;
 use crate::ctx::{resolve_query, ServerCtx};
 use crate::header::ResultCode;
 use crate::packet::DnsPacket;
+use crate::stats::Transport;
 
 const MAX_CONNECTIONS: usize = 512;
 const IDLE_TIMEOUT: Duration = Duration::from_secs(30);
@@ -153,8 +154,11 @@ async fn accept_loop(listener: TcpListener, acceptor: TlsAcceptor, ctx: Arc<Serv
 
 /// Handle a single persistent DoT connection (RFC 7858).
 /// Reads length-prefixed DNS queries until EOF, idle timeout, or error.
-async fn handle_dot_connection<S>(mut stream: S, remote_addr: SocketAddr, ctx: &ServerCtx)
-where
+async fn handle_dot_connection<S>(
+    mut stream: S,
+    remote_addr: SocketAddr,
+    ctx: &std::sync::Arc<ServerCtx>,
+) where
     S: AsyncReadExt + AsyncWriteExt + Unpin,
 {
     loop {
@@ -177,8 +181,6 @@ where
             break;
         };
 
-        // Parse query up-front so we can echo its question section in SERVFAIL
-        // responses when resolve_query fails.
         let query = match DnsPacket::from_buffer(&mut buffer) {
             Ok(q) => q,
             Err(e) => {
@@ -200,8 +202,16 @@ where
             }
         };
 
-        match resolve_query(query.clone(), remote_addr, ctx).await {
-            Ok(resp_buffer) => {
+        match resolve_query(
+            query.clone(),
+            &buffer.buf[..msg_len],
+            remote_addr,
+            ctx,
+            Transport::Dot,
+        )
+        .await
+        {
+            Ok((resp_buffer, _)) => {
                 if write_framed(&mut stream, resp_buffer.filled())
                     .await
                     .is_err()
@@ -269,7 +279,7 @@ where
 mod tests {
     use super::*;
     use std::collections::HashMap;
-    use std::sync::{Mutex, RwLock};
+    use std::sync::Mutex;
 
     use rcgen::{CertificateParams, DnType, KeyPair};
     use rustls::pki_types::{CertificateDer, PrivateKeyDer, PrivatePkcs8KeyDer, ServerName};
@@ -334,54 +344,29 @@ mod tests {
     async fn spawn_dot_server() -> (SocketAddr, CertificateDer<'static>) {
         let (server_tls, cert_der) = test_tls_configs();
 
-        let socket = tokio::net::UdpSocket::bind("127.0.0.1:0").await.unwrap();
-        // Bind an unresponsive upstream and leak it so it lives for the test duration.
-        let blackhole = Box::leak(Box::new(std::net::UdpSocket::bind("127.0.0.1:0").unwrap()));
-        let upstream_addr = blackhole.local_addr().unwrap();
-        let ctx = Arc::new(ServerCtx {
-            socket,
-            zone_map: {
-                let mut m = HashMap::new();
-                let mut inner = HashMap::new();
-                inner.insert(
-                    QueryType::A,
-                    vec![DnsRecord::A {
-                        domain: "dot-test.example".to_string(),
-                        addr: std::net::Ipv4Addr::new(10, 0, 0, 1),
-                        ttl: 300,
-                    }],
-                );
-                m.insert("dot-test.example".to_string(), inner);
-                m
-            },
-            cache: RwLock::new(crate::cache::DnsCache::new(100, 60, 86400)),
-            stats: Mutex::new(crate::stats::ServerStats::new()),
-            overrides: RwLock::new(crate::override_store::OverrideStore::new()),
-            blocklist: RwLock::new(crate::blocklist::BlocklistStore::new()),
-            query_log: Mutex::new(crate::query_log::QueryLog::new(100)),
-            services: Mutex::new(crate::service_store::ServiceStore::new()),
-            lan_peers: Mutex::new(crate::lan::PeerStore::new(90)),
-            forwarding_rules: Vec::new(),
-            upstream: Mutex::new(crate::forward::Upstream::Udp(upstream_addr)),
-            upstream_auto: false,
-            upstream_port: 53,
-            lan_ip: Mutex::new(std::net::Ipv4Addr::LOCALHOST),
-            timeout: Duration::from_millis(200),
-            proxy_tld: "numa".to_string(),
-            proxy_tld_suffix: ".numa".to_string(),
-            lan_enabled: false,
-            config_path: String::new(),
-            config_found: false,
-            config_dir: std::path::PathBuf::from("/tmp"),
-            data_dir: std::path::PathBuf::from("/tmp"),
-            tls_config: Some(arc_swap::ArcSwap::from(server_tls)),
-            upstream_mode: crate::config::UpstreamMode::Forward,
-            root_hints: Vec::new(),
-            srtt: RwLock::new(crate::srtt::SrttCache::new(true)),
-            inflight: Mutex::new(HashMap::new()),
-            dnssec_enabled: false,
-            dnssec_strict: false,
-        });
+        let upstream_addr = crate::testutil::blackhole_upstream();
+
+        let mut ctx = crate::testutil::test_ctx().await;
+        ctx.zone_map = {
+            let mut m = HashMap::new();
+            let mut inner = HashMap::new();
+            inner.insert(
+                QueryType::A,
+                vec![DnsRecord::A {
+                    domain: "dot-test.example".to_string(),
+                    addr: std::net::Ipv4Addr::new(10, 0, 0, 1),
+                    ttl: 300,
+                }],
+            );
+            m.insert("dot-test.example".to_string(), inner);
+            m
+        };
+        ctx.upstream_pool = Mutex::new(crate::forward::UpstreamPool::new(
+            vec![crate::forward::Upstream::Udp(upstream_addr)],
+            vec![],
+        ));
+        ctx.tls_config = Some(arc_swap::ArcSwap::from(server_tls));
+        let ctx = Arc::new(ctx);
 
         let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
         let addr = listener.local_addr().unwrap();

src/forward.rs

@@ -1,12 +1,16 @@
 use std::fmt;
-use std::net::SocketAddr;
-use std::time::Duration;
+use std::net::{IpAddr, SocketAddr};
+use std::sync::{Arc, RwLock};
+use std::time::{Duration, Instant};
 
 use tokio::net::UdpSocket;
 use tokio::time::timeout;
 
 use crate::buffer::BytePacketBuffer;
+use crate::odoh::{query_through_relay, OdohConfigCache};
 use crate::packet::DnsPacket;
+use crate::srtt::SrttCache;
+use crate::stats::UpstreamTransport;
 use crate::Result;
 
 #[derive(Clone)]
@@ -16,6 +20,41 @@ pub enum Upstream {
         url: String,
         client: reqwest::Client,
     },
+    Dot {
+        addr: SocketAddr,
+        tls_name: Option<String>,
+        connector: tokio_rustls::TlsConnector,
+    },
+    /// Oblivious DNS-over-HTTPS (RFC 9230). Queries are HPKE-sealed to the
+    /// target and forwarded through an independent relay. Target host lives
+    /// on `target_config` (single source of truth — the cache keys on it).
+    Odoh {
+        relay_url: String,
+        target_path: String,
+        client: reqwest::Client,
+        target_config: Arc<OdohConfigCache>,
+    },
+}
+
+impl Upstream {
+    /// IP address to key SRTT tracking on, if the upstream has a stable one.
+    /// `Doh` and `Odoh` route through a URL + connection pool, so there's no
+    /// single IP to track; SRTT is skipped for them.
+    pub fn tracked_ip(&self) -> Option<IpAddr> {
+        match self {
+            Upstream::Udp(addr) | Upstream::Dot { addr, .. } => Some(addr.ip()),
+            Upstream::Doh { .. } | Upstream::Odoh { .. } => None,
+        }
+    }
+
+    pub fn transport(&self) -> UpstreamTransport {
+        match self {
+            Upstream::Udp(_) => UpstreamTransport::Udp,
+            Upstream::Doh { .. } => UpstreamTransport::Doh,
+            Upstream::Dot { .. } => UpstreamTransport::Dot,
+            Upstream::Odoh { .. } => UpstreamTransport::Odoh,
+        }
+    }
 }
 
 impl PartialEq for Upstream {
@@ -23,16 +62,206 @@ impl PartialEq for Upstream {
         match (self, other) {
             (Self::Udp(a), Self::Udp(b)) => a == b,
             (Self::Doh { url: a, .. }, Self::Doh { url: b, .. }) => a == b,
+            (Self::Dot { addr: a, .. }, Self::Dot { addr: b, .. }) => a == b,
+            (
+                Self::Odoh {
+                    relay_url: ra,
+                    target_path: pa,
+                    target_config: ca,
+                    ..
+                },
+                Self::Odoh {
+                    relay_url: rb,
+                    target_path: pb,
+                    target_config: cb,
+                    ..
+                },
+            ) => ra == rb && pa == pb && ca.target_host() == cb.target_host(),
             _ => false,
         }
     }
 }
 
+impl fmt::Debug for Upstream {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Display::fmt(self, f)
+    }
+}
+
 impl fmt::Display for Upstream {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Upstream::Udp(addr) => write!(f, "{}", addr),
             Upstream::Doh { url, .. } => f.write_str(url),
+            Upstream::Dot { addr, tls_name, .. } => match tls_name {
+                Some(name) => write!(f, "tls://{}#{}", addr, name),
+                None => write!(f, "tls://{}", addr),
+            },
+            Upstream::Odoh {
+                relay_url,
+                target_path,
+                target_config,
+                ..
+            } => write!(
+                f,
+                "odoh://{}{} via {}",
+                target_config.target_host(),
+                target_path,
+                relay_url
+            ),
+        }
+    }
+}
+
+pub(crate) fn parse_upstream_addr(
+    s: &str,
+    default_port: u16,
+) -> std::result::Result<SocketAddr, String> {
+    // Try full socket addr first: "1.2.3.4:5353" or "[::1]:5353"
+    if let Ok(addr) = s.parse::<SocketAddr>() {
+        return Ok(addr);
+    }
+    // Bare IP: "1.2.3.4" or "::1"
+    if let Ok(ip) = s.parse::<IpAddr>() {
+        return Ok(SocketAddr::new(ip, default_port));
+    }
+    Err(format!("invalid upstream address: {}", s))
+}
+
+/// Parse a slice of upstream address strings into `Upstream` values, failing
+/// on the first invalid entry.
+pub fn parse_upstream_list(addrs: &[String], default_port: u16) -> Result<Vec<Upstream>> {
+    addrs
+        .iter()
+        .map(|s| parse_upstream(s, default_port))
+        .collect()
+}
+
+pub fn parse_upstream(s: &str, default_port: u16) -> Result<Upstream> {
+    if s.starts_with("https://") {
+        return Ok(Upstream::Doh {
+            url: s.to_string(),
+            client: build_https_client(),
+        });
+    }
+    // tls://IP:PORT#hostname  or  tls://IP#hostname  (default port 853)
+    if let Some(rest) = s.strip_prefix("tls://") {
+        let (addr_part, tls_name) = match rest.find('#') {
+            Some(i) => (&rest[..i], Some(rest[i + 1..].to_string())),
+            None => (rest, None),
+        };
+        let addr = parse_upstream_addr(addr_part, 853)?;
+        let connector = build_dot_connector()?;
+        return Ok(Upstream::Dot {
+            addr,
+            tls_name,
+            connector,
+        });
+    }
+    let addr = parse_upstream_addr(s, default_port)?;
+    Ok(Upstream::Udp(addr))
+}
+
+/// HTTP/2 client tuned for DoH/ODoH: small windows for low latency, long-lived
+/// keep-alive. Shared by the DoH upstream and the ODoH config-fetcher +
+/// seal/open path. Pool defaults to one idle conn per host — good for
+/// resolvers that talk to a single upstream; relays that fan out to many
+/// targets should use [`build_https_client_with_pool`].
+pub fn build_https_client() -> reqwest::Client {
+    build_https_client_with_pool(1)
+}
+
+/// Same shape as [`build_https_client`], but caller picks
+/// `pool_max_idle_per_host`. Relay workloads hit many distinct target hosts
+/// and benefit from a larger pool so warm connections survive concurrent
+/// fan-out.
+pub fn build_https_client_with_pool(pool_max_idle_per_host: usize) -> reqwest::Client {
+    https_client_builder(pool_max_idle_per_host)
+        .build()
+        .unwrap_or_default()
+}
+
+/// HTTPS client for the ODoH upstream, with bootstrap-IP overrides applied
+/// so relay/target hostname resolution can bypass system DNS.
+pub fn build_odoh_client(odoh: &crate::config::OdohUpstream) -> reqwest::Client {
+    let mut builder = https_client_builder(1);
+    if let Some(addr) = odoh.relay_bootstrap {
+        builder = builder.resolve(&odoh.relay_host, addr);
+    }
+    if let Some(addr) = odoh.target_bootstrap {
+        builder = builder.resolve(&odoh.target_host, addr);
+    }
+    builder.build().unwrap_or_default()
+}
+
+fn https_client_builder(pool_max_idle_per_host: usize) -> reqwest::ClientBuilder {
+    reqwest::Client::builder()
+        .use_rustls_tls()
+        .http2_initial_stream_window_size(65_535)
+        .http2_initial_connection_window_size(65_535)
+        .http2_keep_alive_interval(Duration::from_secs(15))
+        .http2_keep_alive_while_idle(true)
+        .http2_keep_alive_timeout(Duration::from_secs(10))
+        .pool_idle_timeout(Duration::from_secs(300))
+        .pool_max_idle_per_host(pool_max_idle_per_host)
+}
+
+fn build_dot_connector() -> Result<tokio_rustls::TlsConnector> {
+    let _ = rustls::crypto::ring::default_provider().install_default();
+    let mut root_store = rustls::RootCertStore::empty();
+    root_store.extend(webpki_roots::TLS_SERVER_ROOTS.iter().cloned());
+    let config = rustls::ClientConfig::builder()
+        .with_root_certificates(root_store)
+        .with_no_client_auth();
+    Ok(tokio_rustls::TlsConnector::from(std::sync::Arc::new(
+        config,
+    )))
+}
+
+#[derive(Clone)]
+pub struct UpstreamPool {
+    primary: Vec<Upstream>,
+    fallback: Vec<Upstream>,
+}
+
+impl UpstreamPool {
+    pub fn new(primary: Vec<Upstream>, fallback: Vec<Upstream>) -> Self {
+        Self { primary, fallback }
+    }
+
+    pub fn preferred(&self) -> Option<&Upstream> {
+        self.primary.first().or(self.fallback.first())
+    }
+
+    pub fn set_primary(&mut self, primary: Vec<Upstream>) {
+        self.primary = primary;
+    }
+
+    /// Update the primary upstream if `new_addr` (parsed with `port`) differs
+    /// from the current preferred upstream. Returns `true` if the pool changed.
+    pub fn maybe_update_primary(&mut self, new_addr: &str, port: u16) -> bool {
+        let Ok(new_sock) = format!("{}:{}", new_addr, port).parse::<SocketAddr>() else {
+            return false;
+        };
+        let new_upstream = Upstream::Udp(new_sock);
+        if self.preferred() == Some(&new_upstream) {
+            return false;
+        }
+        self.primary = vec![new_upstream];
+        true
+    }
+
+    pub fn label(&self) -> String {
+        match self.preferred() {
+            Some(u) => {
+                let total = self.primary.len() + self.fallback.len();
+                if total > 1 {
+                    format!("{} (+{} more)", u, total - 1)
+                } else {
+                    u.to_string()
+                }
+            }
+            None => "none".to_string(),
         }
     }
 }
@@ -42,10 +271,11 @@ pub async fn forward_query(
     upstream: &Upstream,
     timeout_duration: Duration,
 ) -> Result<DnsPacket> {
-    match upstream {
-        Upstream::Udp(addr) => forward_udp(query, *addr, timeout_duration).await,
-        Upstream::Doh { url, client } => forward_doh(query, url, client, timeout_duration).await,
-    }
+    let mut send_buffer = BytePacketBuffer::new();
+    query.write(&mut send_buffer)?;
+    let data = forward_query_raw(send_buffer.filled(), upstream, timeout_duration).await?;
+    let mut recv_buffer = BytePacketBuffer::from_bytes(&data);
+    DnsPacket::from_buffer(&mut recv_buffer)
 }
 
 pub(crate) async fn forward_udp(
@@ -53,24 +283,10 @@ pub(crate) async fn forward_udp(
     upstream: SocketAddr,
     timeout_duration: Duration,
 ) -> Result<DnsPacket> {
-    let socket = UdpSocket::bind("0.0.0.0:0").await?;
-
     let mut send_buffer = BytePacketBuffer::new();
     query.write(&mut send_buffer)?;
-
-    socket.send_to(send_buffer.filled(), upstream).await?;
-
-    let mut recv_buffer = BytePacketBuffer::new();
-    let (size, _) = timeout(timeout_duration, socket.recv_from(&mut recv_buffer.buf)).await??;
-
-    if size == recv_buffer.buf.len() {
-        log::debug!(
-            "upstream response truncated ({} bytes, buffer {})",
-            size,
-            recv_buffer.buf.len()
-        );
-    }
-
+    let data = forward_udp_raw(send_buffer.filled(), upstream, timeout_duration).await?;
+    let mut recv_buffer = BytePacketBuffer::from_bytes(&data);
     DnsPacket::from_buffer(&mut recv_buffer)
 }
 
@@ -107,22 +323,224 @@ pub(crate) async fn forward_tcp(
     DnsPacket::from_buffer(&mut recv_buffer)
 }
 
-async fn forward_doh(
-    query: &DnsPacket,
+async fn forward_dot_raw(
+    wire: &[u8],
+    addr: SocketAddr,
+    tls_name: &Option<String>,
+    connector: &tokio_rustls::TlsConnector,
+    timeout_duration: Duration,
+) -> Result<Vec<u8>> {
+    use rustls::pki_types::ServerName;
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+    use tokio::net::TcpStream;
+
+    let server_name = match tls_name {
+        Some(name) => ServerName::try_from(name.clone())?,
+        None => ServerName::try_from(addr.ip().to_string())?,
+    };
+
+    let tcp = timeout(timeout_duration, TcpStream::connect(addr)).await??;
+    let mut tls = timeout(timeout_duration, connector.connect(server_name, tcp)).await??;
+
+    let mut outbuf = Vec::with_capacity(2 + wire.len());
+    outbuf.extend_from_slice(&(wire.len() as u16).to_be_bytes());
+    outbuf.extend_from_slice(wire);
+    timeout(timeout_duration, tls.write_all(&outbuf)).await??;
+
+    let mut len_buf = [0u8; 2];
+    timeout(timeout_duration, tls.read_exact(&mut len_buf)).await??;
+    let resp_len = u16::from_be_bytes(len_buf) as usize;
+
+    let mut data = vec![0u8; resp_len];
+    timeout(timeout_duration, tls.read_exact(&mut data)).await??;
+
+    Ok(data)
+}
+
+pub async fn forward_query_raw(
+    wire: &[u8],
+    upstream: &Upstream,
+    timeout_duration: Duration,
+) -> Result<Vec<u8>> {
+    match upstream {
+        Upstream::Udp(addr) => forward_udp_raw(wire, *addr, timeout_duration).await,
+        Upstream::Doh { url, client } => forward_doh_raw(wire, url, client, timeout_duration).await,
+        Upstream::Dot {
+            addr,
+            tls_name,
+            connector,
+        } => forward_dot_raw(wire, *addr, tls_name, connector, timeout_duration).await,
+        Upstream::Odoh {
+            relay_url,
+            target_path,
+            client,
+            target_config,
+        } => {
+            query_through_relay(
+                wire,
+                relay_url,
+                target_path,
+                client,
+                target_config,
+                timeout_duration,
+            )
+            .await
+        }
+    }
+}
+
+pub async fn forward_with_hedging_raw(
+    wire: &[u8],
+    primary: &Upstream,
+    secondary: &Upstream,
+    hedge_delay: Duration,
+    timeout_duration: Duration,
+) -> Result<Vec<u8>> {
+    use tokio::time::sleep;
+
+    let primary_fut = forward_query_raw(wire, primary, timeout_duration);
+    tokio::pin!(primary_fut);
+
+    let delay = sleep(hedge_delay);
+    tokio::pin!(delay);
+
+    // Phase 1: wait for either primary to return, or the hedge delay.
+    tokio::select! {
+        result = &mut primary_fut => return result,
+        _ = &mut delay => {}
+    }
+
+    // Phase 2: hedge delay expired — fire secondary while still polling primary.
+    let secondary_fut = forward_query_raw(wire, secondary, timeout_duration);
+    tokio::pin!(secondary_fut);
+
+    // First successful response wins. If one errors, wait for the other.
+    let mut primary_err: Option<crate::Error> = None;
+    let mut secondary_err: Option<crate::Error> = None;
+
+    loop {
+        tokio::select! {
+            r = &mut primary_fut, if primary_err.is_none() => {
+                match r {
+                    Ok(resp) => return Ok(resp),
+                    Err(e) => {
+                        if let Some(se) = secondary_err.take() {
+                            return Err(se);
+                        }
+                        primary_err = Some(e);
+                    }
+                }
+            }
+            r = &mut secondary_fut, if secondary_err.is_none() => {
+                match r {
+                    Ok(resp) => return Ok(resp),
+                    Err(e) => {
+                        if let Some(pe) = primary_err.take() {
+                            return Err(pe);
+                        }
+                        secondary_err = Some(e);
+                    }
+                }
+            }
+        }
+
+        match (primary_err, secondary_err) {
+            (Some(pe), Some(_)) => return Err(pe),
+            (pe, se) => {
+                primary_err = pe;
+                secondary_err = se;
+            }
+        }
+    }
+}
+
+pub async fn forward_with_failover_raw(
+    wire: &[u8],
+    pool: &UpstreamPool,
+    srtt: &RwLock<SrttCache>,
+    timeout_duration: Duration,
+    hedge_delay: Duration,
+) -> Result<Vec<u8>> {
+    let mut candidates: Vec<(usize, u64)> = {
+        let srtt_read = srtt.read().unwrap();
+        pool.primary
+            .iter()
+            .enumerate()
+            .map(|(i, u)| {
+                let rtt = u.tracked_ip().map(|ip| srtt_read.get(ip)).unwrap_or(0);
+                (i, rtt)
+            })
+            .collect()
+    };
+    candidates.sort_by_key(|&(_, rtt)| rtt);
+
+    let all_upstreams: Vec<&Upstream> = candidates
+        .iter()
+        .map(|&(i, _)| &pool.primary[i])
+        .chain(pool.fallback.iter())
+        .collect();
+
+    let mut last_err: Option<Box<dyn std::error::Error + Send + Sync>> = None;
+
+    for upstream in &all_upstreams {
+        let start = Instant::now();
+        let result = if !hedge_delay.is_zero() {
+            // Hedge against the same upstream: independent h2 streams (DoH),
+            // independent UDP packets (plain DNS), or independent TLS
+            // connections (DoT). Rescues packet loss, dispatch spikes, and
+            // TLS handshake stalls.
+            forward_with_hedging_raw(wire, upstream, upstream, hedge_delay, timeout_duration).await
+        } else {
+            forward_query_raw(wire, upstream, timeout_duration).await
+        };
+        match result {
+            Ok(resp) => {
+                if let Some(ip) = upstream.tracked_ip() {
+                    let rtt_ms = start.elapsed().as_millis() as u64;
+                    srtt.write().unwrap().record_rtt(ip, rtt_ms, false);
+                }
+                return Ok(resp);
+            }
+            Err(e) => {
+                if let Some(ip) = upstream.tracked_ip() {
+                    srtt.write().unwrap().record_failure(ip);
+                }
+                log::debug!("upstream {} failed: {}", upstream, e);
+                last_err = Some(e);
+            }
+        }
+    }
+
+    Err(last_err.unwrap_or_else(|| "no upstream configured".into()))
+}
+
+async fn forward_udp_raw(
+    wire: &[u8],
+    upstream: SocketAddr,
+    timeout_duration: Duration,
+) -> Result<Vec<u8>> {
+    let socket = UdpSocket::bind("0.0.0.0:0").await?;
+    socket.send_to(wire, upstream).await?;
+
+    let mut recv_buf = vec![0u8; 4096];
+    let (size, _) = timeout(timeout_duration, socket.recv_from(&mut recv_buf)).await??;
+    recv_buf.truncate(size);
+    Ok(recv_buf)
+}
+
+async fn forward_doh_raw(
+    wire: &[u8],
     url: &str,
     client: &reqwest::Client,
     timeout_duration: Duration,
-) -> Result<DnsPacket> {
-    let mut send_buffer = BytePacketBuffer::new();
-    query.write(&mut send_buffer)?;
-
+) -> Result<Vec<u8>> {
     let resp = timeout(
         timeout_duration,
         client
             .post(url)
             .header("content-type", "application/dns-message")
             .header("accept", "application/dns-message")
-            .body(send_buffer.filled().to_vec())
+            .body(wire.to_vec())
             .send(),
     )
     .await??
@@ -130,9 +548,25 @@ async fn forward_doh(
 
     let bytes = resp.bytes().await?;
     log::debug!("DoH response: {} bytes", bytes.len());
+    Ok(bytes.to_vec())
+}
 
-    let mut recv_buffer = BytePacketBuffer::from_bytes(&bytes);
-    DnsPacket::from_buffer(&mut recv_buffer)
+/// Send a lightweight keepalive query to a DoH upstream to prevent
+/// the HTTP/2 + TLS connection from going idle and being torn down.
+pub async fn keepalive_doh(upstream: &Upstream) {
+    if let Upstream::Doh { url, client } = upstream {
+        // Query for . NS — minimal, always succeeds, response is small
+        let wire: &[u8] = &[
+            0x00, 0x00, // ID
+            0x01, 0x00, // flags: RD=1
+            0x00, 0x01, // QDCOUNT=1
+            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // AN=0, NS=0, AR=0
+            0x00, // root name (.)
+            0x00, 0x02, // type NS
+            0x00, 0x01, // class IN
+        ];
+        let _ = forward_doh_raw(wire, url, client, Duration::from_secs(5)).await;
+    }
 }
 
 #[cfg(test)]
@@ -271,4 +705,179 @@ mod tests {
         let result = forward_query(&make_query(), &upstream, Duration::from_millis(100)).await;
         assert!(result.is_err());
     }
+
+    #[test]
+    fn parse_addr_ip_only() {
+        let addr = parse_upstream_addr("1.2.3.4", 53).unwrap();
+        assert_eq!(addr, "1.2.3.4:53".parse::<SocketAddr>().unwrap());
+    }
+
+    #[test]
+    fn parse_addr_ip_port() {
+        let addr = parse_upstream_addr("1.2.3.4:5353", 53).unwrap();
+        assert_eq!(addr, "1.2.3.4:5353".parse::<SocketAddr>().unwrap());
+    }
+
+    #[test]
+    fn parse_addr_ipv6_bracketed() {
+        let addr = parse_upstream_addr("[::1]:5553", 53).unwrap();
+        assert_eq!(addr, "[::1]:5553".parse::<SocketAddr>().unwrap());
+    }
+
+    #[test]
+    fn parse_addr_ipv6_bare() {
+        let addr = parse_upstream_addr("::1", 53).unwrap();
+        assert_eq!(addr, "[::1]:53".parse::<SocketAddr>().unwrap());
+    }
+
+    #[test]
+    fn pool_label_single() {
+        let pool = UpstreamPool::new(vec![Upstream::Udp("1.2.3.4:53".parse().unwrap())], vec![]);
+        assert_eq!(pool.label(), "1.2.3.4:53");
+    }
+
+    #[test]
+    fn pool_label_multi() {
+        let pool = UpstreamPool::new(
+            vec![Upstream::Udp("1.2.3.4:53".parse().unwrap())],
+            vec![Upstream::Udp("8.8.8.8:53".parse().unwrap())],
+        );
+        assert_eq!(pool.label(), "1.2.3.4:53 (+1 more)");
+    }
+
+    #[tokio::test]
+    async fn failover_tries_next_on_failure() {
+        // First upstream is unreachable, second responds
+        let query = make_query();
+        let response_bytes = to_wire(&make_response(&query));
+
+        let app = axum::Router::new().route(
+            "/dns-query",
+            axum::routing::post(move || {
+                let body = response_bytes.clone();
+                async move {
+                    (
+                        [(axum::http::header::CONTENT_TYPE, "application/dns-message")],
+                        body,
+                    )
+                }
+            }),
+        );
+
+        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let good_addr = listener.local_addr().unwrap();
+        tokio::spawn(axum::serve(listener, app).into_future());
+
+        // Unreachable UDP upstream + working DoH upstream
+        let pool = UpstreamPool::new(
+            vec![
+                Upstream::Udp("127.0.0.1:1".parse().unwrap()), // will fail
+                Upstream::Doh {
+                    url: format!("http://{}/dns-query", good_addr),
+                    client: reqwest::Client::new(),
+                },
+            ],
+            vec![],
+        );
+
+        let srtt = RwLock::new(SrttCache::new(true));
+        let wire = to_wire(&query);
+        let resp_wire = forward_with_failover_raw(
+            &wire,
+            &pool,
+            &srtt,
+            Duration::from_millis(500),
+            Duration::ZERO,
+        )
+        .await
+        .expect("should fail over to second upstream");
+
+        let mut buf = BytePacketBuffer::from_bytes(&resp_wire);
+        let result = DnsPacket::from_buffer(&mut buf).unwrap();
+        assert_eq!(result.header.id, 0xABCD);
+        assert_eq!(result.answers.len(), 1);
+    }
+
+    #[test]
+    fn maybe_update_primary_swaps_when_different() {
+        let mut pool = UpstreamPool::new(
+            vec![Upstream::Udp("1.2.3.4:53".parse().unwrap())],
+            vec![Upstream::Udp("8.8.8.8:53".parse().unwrap())],
+        );
+        assert!(pool.maybe_update_primary("5.6.7.8", 53));
+        assert_eq!(pool.preferred().unwrap().to_string(), "5.6.7.8:53");
+    }
+
+    #[test]
+    fn maybe_update_primary_noop_when_same() {
+        let mut pool =
+            UpstreamPool::new(vec![Upstream::Udp("1.2.3.4:53".parse().unwrap())], vec![]);
+        assert!(!pool.maybe_update_primary("1.2.3.4", 53));
+    }
+
+    #[test]
+    fn maybe_update_primary_rejects_invalid_addr() {
+        let mut pool =
+            UpstreamPool::new(vec![Upstream::Udp("1.2.3.4:53".parse().unwrap())], vec![]);
+        assert!(!pool.maybe_update_primary("not-an-ip", 53));
+        assert_eq!(pool.preferred().unwrap().to_string(), "1.2.3.4:53");
+    }
+
+    fn tcp_closed_port() -> SocketAddr {
+        // Bind a TCP listener, grab the port, drop → kernel returns RST on connect.
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+        let addr = listener.local_addr().unwrap();
+        drop(listener);
+        addr
+    }
+
+    #[tokio::test]
+    async fn udp_failure_records_in_srtt() {
+        let blackhole = crate::testutil::blackhole_upstream();
+        let pool = UpstreamPool::new(vec![Upstream::Udp(blackhole)], vec![]);
+        let srtt = RwLock::new(SrttCache::new(true));
+        let _ = forward_with_failover_raw(
+            &[0u8; 12],
+            &pool,
+            &srtt,
+            Duration::from_millis(100),
+            Duration::ZERO,
+        )
+        .await;
+        assert!(srtt.read().unwrap().is_known(blackhole.ip()));
+    }
+
+    #[tokio::test]
+    async fn dot_failure_records_in_srtt() {
+        let dead1 = tcp_closed_port();
+        let dead2 = tcp_closed_port();
+        let connector = build_dot_connector().unwrap();
+        let pool = UpstreamPool::new(
+            vec![
+                Upstream::Dot {
+                    addr: dead1,
+                    tls_name: Some("dns.quad9.net".to_string()),
+                    connector: connector.clone(),
+                },
+                Upstream::Dot {
+                    addr: dead2,
+                    tls_name: Some("dns.quad9.net".to_string()),
+                    connector,
+                },
+            ],
+            vec![],
+        );
+        let srtt = RwLock::new(SrttCache::new(true));
+        let _ = forward_with_failover_raw(
+            &[0u8; 12],
+            &pool,
+            &srtt,
+            Duration::from_millis(500),
+            Duration::ZERO,
+        )
+        .await;
+        let cache = srtt.read().unwrap();
+        assert!(cache.is_known(dead1.ip()));
+        assert!(cache.is_known(dead2.ip()));
+    }
 }

src/health.rs

@@ -0,0 +1,258 @@
+//! Health metadata and `/health` response shape, shared between the main
+//! HTTP API and the mobile API.
+//!
+//! The static fields (version, hostname, DoT config, CA fingerprint,
+//! feature list) are computed once at startup and stored in [`HealthMeta`]
+//! on `ServerCtx`. Per-request fields (uptime, LAN IP) are computed live.
+//! Both handlers call [`HealthResponse::build`] to assemble the JSON
+//! response from `HealthMeta` + live inputs.
+//!
+//! JSON schema is documented in `docs/implementation/ios-companion-app.md`
+//! §4.2. The iOS companion app's `HealthInfo` struct is the canonical
+//! consumer; any change to this response must keep that struct decoding
+//! cleanly (all consumed fields are optional on the Swift side, but
+//! `lan_ip` is load-bearing for the pipeline).
+
+use std::net::Ipv4Addr;
+use std::path::Path;
+use std::time::Instant;
+
+use ring::digest::{digest, SHA256};
+use serde::Serialize;
+
+/// Immutable health metadata cached on `ServerCtx`. Built once at startup
+/// from config + file-system state (CA cert).
+#[derive(Clone)]
+pub struct HealthMeta {
+    pub version: &'static str,
+    pub hostname: String,
+    pub sni: String,
+    pub dot_enabled: bool,
+    pub dot_port: u16,
+    pub api_port: u16,
+    pub ca_fingerprint_sha256: Option<String>,
+    pub features: Vec<String>,
+    pub started_at: Instant,
+}
+
+impl HealthMeta {
+    /// Minimal `HealthMeta` for unit tests that construct a `ServerCtx`
+    /// without needing the real startup flow (CA file reads, hostname
+    /// detection, etc.). Deterministic values so test JSON assertions
+    /// stay stable.
+    #[cfg(test)]
+    pub fn test_fixture() -> Self {
+        HealthMeta {
+            version: crate::version(),
+            hostname: "test-host".to_string(),
+            sni: "numa.numa".to_string(),
+            dot_enabled: false,
+            dot_port: 853,
+            api_port: 8765,
+            ca_fingerprint_sha256: None,
+            features: vec![],
+            started_at: Instant::now(),
+        }
+    }
+
+    /// Build a new HealthMeta from config + startup-time environment.
+    /// Call once at server boot; the returned value is cheap to clone
+    /// (small number of short strings) and lives on `ServerCtx`.
+    ///
+    /// The argument count is deliberate — each flag corresponds to a
+    /// specific config value and is clearly named at the call site.
+    /// Collapsing into a struct hides nothing meaningful for a one-call
+    /// initializer.
+    #[allow(clippy::too_many_arguments)]
+    pub fn build(
+        data_dir: &Path,
+        dot_enabled: bool,
+        dot_port: u16,
+        api_port: u16,
+        dnssec_enabled: bool,
+        recursive_enabled: bool,
+        mdns_enabled: bool,
+        blocking_enabled: bool,
+        doh_enabled: bool,
+    ) -> Self {
+        let ca_path = data_dir.join("ca.pem");
+        let ca_fingerprint_sha256 = compute_ca_fingerprint(&ca_path);
+
+        let mut features = Vec::new();
+        if doh_enabled {
+            features.push("doh".to_string());
+        }
+        if dot_enabled {
+            features.push("dot".to_string());
+        }
+        if recursive_enabled {
+            features.push("recursive".to_string());
+        }
+        if blocking_enabled {
+            features.push("blocking".to_string());
+        }
+        if mdns_enabled {
+            features.push("mdns".to_string());
+        }
+        if dnssec_enabled {
+            features.push("dnssec".to_string());
+        }
+
+        HealthMeta {
+            version: crate::version(),
+            hostname: crate::hostname(),
+            sni: "numa.numa".to_string(),
+            dot_enabled,
+            dot_port,
+            api_port,
+            ca_fingerprint_sha256,
+            features,
+            started_at: Instant::now(),
+        }
+    }
+}
+
+/// JSON response shape returned by `GET /health` on both main and mobile APIs.
+///
+/// Fields are organized to match the iOS companion app's
+/// `HealthInfo` Swift struct — see `ios-companion-app.md` §4.2.
+#[derive(Serialize)]
+pub struct HealthResponse {
+    pub status: &'static str,
+    pub version: &'static str,
+    pub uptime_secs: u64,
+    pub hostname: String,
+    pub lan_ip: Option<String>,
+    pub sni: String,
+    pub dot: DotBlock,
+    pub api: ApiBlock,
+    pub ca: CaBlock,
+    pub features: Vec<String>,
+}
+
+#[derive(Serialize)]
+pub struct DotBlock {
+    pub enabled: bool,
+    pub port: Option<u16>,
+}
+
+#[derive(Serialize)]
+pub struct ApiBlock {
+    pub port: u16,
+}
+
+#[derive(Serialize)]
+pub struct CaBlock {
+    pub present: bool,
+    pub fingerprint_sha256: Option<String>,
+}
+
+impl HealthResponse {
+    /// Assemble a fresh `HealthResponse` from the cached metadata and
+    /// the current LAN IP (which may change across network transitions).
+    /// Pass `None` for `lan_ip` if detection fails — the response still
+    /// returns 200 OK, just without the LAN address.
+    pub fn build(meta: &HealthMeta, lan_ip: Option<Ipv4Addr>) -> Self {
+        HealthResponse {
+            status: "ok",
+            version: meta.version,
+            uptime_secs: meta.started_at.elapsed().as_secs(),
+            hostname: meta.hostname.clone(),
+            lan_ip: lan_ip.map(|ip| ip.to_string()),
+            sni: meta.sni.clone(),
+            dot: DotBlock {
+                enabled: meta.dot_enabled,
+                port: if meta.dot_enabled {
+                    Some(meta.dot_port)
+                } else {
+                    None
+                },
+            },
+            api: ApiBlock {
+                port: meta.api_port,
+            },
+            ca: CaBlock {
+                present: meta.ca_fingerprint_sha256.is_some(),
+                fingerprint_sha256: meta.ca_fingerprint_sha256.clone(),
+            },
+            features: meta.features.clone(),
+        }
+    }
+}
+
+/// Read the CA cert at `ca_path` and return its SHA-256 fingerprint as a
+/// lowercase hex string, or None if the file doesn't exist or can't be read.
+///
+/// Hashes the raw PEM bytes for simplicity. A more canonical SPKI-based
+/// fingerprint would require parsing the PEM → DER → extracting
+/// SubjectPublicKeyInfo, which adds complexity without meaningful benefit
+/// for our use case (the iOS app uses the fingerprint only for display
+/// and to detect rotation).
+fn compute_ca_fingerprint(ca_path: &Path) -> Option<String> {
+    let pem = std::fs::read(ca_path).ok()?;
+    let hash = digest(&SHA256, &pem);
+    let hex: String = hash.as_ref().iter().map(|b| format!("{:02x}", b)).collect();
+    Some(hex)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn health_response_contains_required_fields() {
+        let meta = HealthMeta {
+            version: "0.10.0",
+            hostname: "test-host".to_string(),
+            sni: "numa.numa".to_string(),
+            dot_enabled: true,
+            dot_port: 853,
+            api_port: 8765,
+            ca_fingerprint_sha256: Some("abcd1234".to_string()),
+            features: vec!["dot".to_string(), "dnssec".to_string()],
+            started_at: Instant::now(),
+        };
+
+        let response = HealthResponse::build(&meta, Some(Ipv4Addr::new(192, 168, 1, 50)));
+        let json = serde_json::to_string(&response).unwrap();
+
+        assert!(json.contains("\"status\":\"ok\""));
+        assert!(json.contains("\"version\":\"0.10.0\""));
+        assert!(json.contains("\"hostname\":\"test-host\""));
+        assert!(json.contains("\"lan_ip\":\"192.168.1.50\""));
+        assert!(json.contains("\"sni\":\"numa.numa\""));
+        assert!(json.contains("\"port\":853"));
+        assert!(json.contains("\"port\":8765"));
+        assert!(json.contains("\"fingerprint_sha256\":\"abcd1234\""));
+        assert!(json.contains("\"features\":[\"dot\",\"dnssec\"]"));
+    }
+
+    #[test]
+    fn health_response_omits_dot_port_when_disabled() {
+        let meta = HealthMeta {
+            version: "0.10.0",
+            hostname: "t".to_string(),
+            sni: "numa.numa".to_string(),
+            dot_enabled: false,
+            dot_port: 853,
+            api_port: 8765,
+            ca_fingerprint_sha256: None,
+            features: vec![],
+            started_at: Instant::now(),
+        };
+
+        let response = HealthResponse::build(&meta, None);
+        let json = serde_json::to_string(&response).unwrap();
+
+        assert!(json.contains("\"enabled\":false"));
+        assert!(json.contains("\"dot\":{\"enabled\":false,\"port\":null}"));
+        assert!(json.contains("\"present\":false"));
+        assert!(json.contains("\"lan_ip\":null"));
+    }
+
+    #[test]
+    fn ca_fingerprint_returns_none_for_missing_file() {
+        let fp = compute_ca_fingerprint(Path::new("/nonexistent/ca.pem"));
+        assert!(fp.is_none());
+    }
+}

src/lan.rs

@@ -9,6 +9,7 @@ use crate::buffer::BytePacketBuffer;
 use crate::config::LanConfig;
 use crate::ctx::ServerCtx;
 use crate::header::DnsHeader;
+use crate::health::HealthMeta;
 use crate::question::{DnsQuestion, QueryType};
 
 // --- Constants ---
@@ -18,6 +19,18 @@ const MDNS_PORT: u16 = 5353;
 const SERVICE_TYPE: &str = "_numa._tcp.local";
 const MDNS_TTL: u32 = 120;
 
+// TXT record key prefixes (including the trailing `=`). Shared between
+// the sender (`build_announcement`) and the receiver (`parse_mdns_response`)
+// to prevent drift — both sides match on the same literal, not on two
+// independent string constants that could diverge.
+const TXT_SERVICES: &str = "services=";
+const TXT_ID: &str = "id=";
+const TXT_VERSION: &str = "version=";
+const TXT_API_PORT: &str = "api_port=";
+const TXT_PROTO: &str = "proto=";
+const TXT_DOT_PORT: &str = "dot_port=";
+const TXT_CA_FP: &str = "ca_fp=";
+
 // --- Peer Store ---
 
 pub struct PeerStore {
@@ -97,14 +110,16 @@ pub fn detect_lan_ip() -> Option<Ipv4Addr> {
     }
 }
 
+/// Short hostname for mDNS instance names (`<short>._numa._tcp.local`).
+/// Truncates at the first `.` so `macbook-pro.local` becomes `macbook-pro`.
+/// Uses the shared `crate::hostname()` helper as the source.
 fn get_hostname() -> String {
-    std::process::Command::new("hostname")
-        .output()
-        .ok()
-        .and_then(|o| String::from_utf8(o.stdout).ok())
-        .map(|h| h.trim().split('.').next().unwrap_or("numa").to_string())
-        .filter(|h| !h.is_empty())
-        .unwrap_or_else(|| "numa".to_string())
+    crate::hostname()
+        .split('.')
+        .next()
+        .filter(|s| !s.is_empty())
+        .unwrap_or("numa")
+        .to_string()
 }
 
 /// Generate a per-process instance ID for self-filtering on multi-instance hosts
@@ -168,13 +183,22 @@ pub async fn start_lan_discovery(ctx: Arc<ServerCtx>, config: &LanConfig) {
                     .map(|e| (e.name.clone(), e.target_port))
                     .collect()
             };
-            if services.is_empty() {
-                continue;
-            }
+            // Note: we always announce ourselves, even when the
+            // services list is empty. The announcement still carries
+            // the mobile API port + version + CA fingerprint in TXT,
+            // which is what the iOS companion app browses for via
+            // NWBrowser on `_numa._tcp.local`. Other Numa peers
+            // receive these empty-services announcements too and
+            // correctly ignore them in parse_mdns_response (the
+            // receiver only processes when services is non-empty).
             let current_ip = *sender_ctx.lan_ip.lock().unwrap();
-            if let Ok(pkt) =
-                build_announcement(&sender_hostname, current_ip, &services, &sender_instance_id)
-            {
+            if let Ok(pkt) = build_announcement(
+                &sender_hostname,
+                current_ip,
+                &services,
+                &sender_instance_id,
+                &sender_ctx.health_meta,
+            ) {
                 let _ = sender_socket.send_to(pkt.filled(), dest).await;
             }
         }
@@ -240,6 +264,7 @@ fn build_announcement(
     ip: Ipv4Addr,
     services: &[(String, u16)],
     inst_id: &str,
+    meta: &HealthMeta,
 ) -> crate::Result<BytePacketBuffer> {
     let mut buf = BytePacketBuffer::new();
     let instance_name = format!("{}._numa._tcp.local", hostname);
@@ -260,7 +285,11 @@ fn build_announcement(
     patch_rdlen(&mut buf, rdlen_pos, rdata_start)?;
 
     // SRV: <instance>._numa._tcp.local → <hostname>.local
-    // Port in SRV is informational; actual service ports are in TXT
+    // Port = mobile API port, which is what the iOS companion app resolves
+    // the SRV record for. Legacy Numa peers don't read the SRV port (see
+    // parse_mdns_response — it only uses TXT services= for peer discovery),
+    // so changing the SRV port from "first service's port" to the mobile
+    // API port is backwards compatible.
     write_record_header(
         &mut buf,
         &instance_name,
@@ -273,11 +302,13 @@ fn build_announcement(
     let rdata_start = buf.pos();
     buf.write_u16(0)?; // priority
     buf.write_u16(0)?; // weight
-    buf.write_u16(services.first().map(|(_, p)| *p).unwrap_or(0))?; // first service port for SRV display
+    buf.write_u16(meta.api_port)?; // mobile API port, for iOS companion app
     buf.write_qname(&host_local)?;
     patch_rdlen(&mut buf, rdlen_pos, rdata_start)?;
 
-    // TXT: services + instance ID for self-filtering
+    // TXT: legacy peer-discovery entries (services, id) + enriched entries
+    // for the iOS companion app (version, api_port, proto, dot_port, ca_fp).
+    // All in one TXT RRset per mDNS convention.
     write_record_header(
         &mut buf,
         &instance_name,
@@ -293,8 +324,21 @@ fn build_announcement(
         .map(|(name, port)| format!("{}:{}", name, port))
         .collect::<Vec<_>>()
         .join(",");
-    write_txt_string(&mut buf, &format!("services={}", svc_str))?;
-    write_txt_string(&mut buf, &format!("id={}", inst_id))?;
+    // Legacy peer-discovery entries (consumed by parse_mdns_response)
+    write_txt_string(&mut buf, &format!("{}{}", TXT_SERVICES, svc_str))?;
+    write_txt_string(&mut buf, &format!("{}{}", TXT_ID, inst_id))?;
+    // Enriched entries (consumed by the iOS/Android companion apps)
+    write_txt_string(&mut buf, &format!("{}{}", TXT_VERSION, meta.version))?;
+    write_txt_string(&mut buf, &format!("{}{}", TXT_API_PORT, meta.api_port))?;
+    if meta.dot_enabled {
+        write_txt_string(&mut buf, &format!("{}dot", TXT_PROTO))?;
+        write_txt_string(&mut buf, &format!("{}{}", TXT_DOT_PORT, meta.dot_port))?;
+    } else {
+        write_txt_string(&mut buf, &format!("{}plain", TXT_PROTO))?;
+    }
+    if let Some(fp) = &meta.ca_fingerprint_sha256 {
+        write_txt_string(&mut buf, &format!("{}{}", TXT_CA_FP, fp))?;
+    }
     patch_rdlen(&mut buf, rdlen_pos, rdata_start)?;
 
     // A: <hostname>.local → IP
@@ -408,7 +452,7 @@ fn parse_mdns_response(data: &[u8]) -> Option<MdnsAnnouncement> {
                         break;
                     }
                     if let Ok(txt) = std::str::from_utf8(&data[pos..pos + txt_len]) {
-                        if let Some(val) = txt.strip_prefix("services=") {
+                        if let Some(val) = txt.strip_prefix(TXT_SERVICES) {
                             let svcs: Vec<(String, u16)> = val
                                 .split(',')
                                 .filter_map(|s| {
@@ -421,7 +465,7 @@ fn parse_mdns_response(data: &[u8]) -> Option<MdnsAnnouncement> {
                             if !svcs.is_empty() {
                                 txt_services = Some(svcs);
                             }
-                        } else if let Some(id) = txt.strip_prefix("id=") {
+                        } else if let Some(id) = txt.strip_prefix(TXT_ID) {
                             peer_instance_id = Some(id.to_string());
                         }
                     }

src/lib.rs

@@ -5,10 +5,15 @@ pub mod cache;
 pub mod config;
 pub mod ctx;
 pub mod dnssec;
+pub mod doh;
 pub mod dot;
 pub mod forward;
 pub mod header;
+pub mod health;
 pub mod lan;
+pub mod mobile_api;
+pub mod mobileconfig;
+pub mod odoh;
 pub mod override_store;
 pub mod packet;
 pub mod proxy;
@@ -16,28 +21,94 @@ pub mod query_log;
 pub mod question;
 pub mod record;
 pub mod recursive;
+pub mod relay;
+pub mod serve;
 pub mod service_store;
+pub mod setup_phone;
 pub mod srtt;
 pub mod stats;
+pub mod svcb;
 pub mod system_dns;
 pub mod tls;
+pub mod wire;
+
+#[cfg(windows)]
+pub mod windows_service;
+
+#[cfg(test)]
+pub(crate) mod testutil;
 
 pub type Error = Box<dyn std::error::Error + Send + Sync>;
 pub type Result<T> = std::result::Result<T, Error>;
 
+/// Build version string. On tagged releases: `0.13.1`. On commits ahead
+/// of a tag: `0.13.1+a87f907`. With uncommitted changes: `0.13.1+a87f907-dirty`.
+/// Falls back to `CARGO_PKG_VERSION` when built outside a git repo (e.g.
+/// from a source tarball).
+pub fn version() -> &'static str {
+    option_env!("NUMA_BUILD_VERSION").unwrap_or(env!("CARGO_PKG_VERSION"))
+}
+
+/// Detect the machine hostname via the `hostname` command. Returns the
+/// full hostname (e.g., `macbook-pro.local`), or `"numa"` if the command
+/// fails. Call sites that need the short form (e.g., mDNS instance
+/// names) should truncate at the first `.`.
+pub fn hostname() -> String {
+    std::process::Command::new("hostname")
+        .output()
+        .ok()
+        .and_then(|o| String::from_utf8(o.stdout).ok())
+        .map(|h| h.trim().to_string())
+        .filter(|h| !h.is_empty())
+        .unwrap_or_else(|| "numa".to_string())
+}
+
+/// Path to suggest to an interactive user when asking them to create
+/// `numa.toml`. Prefers `$HOME/.config/numa/numa.toml` when HOME is set
+/// (actionable without sudo); falls back to `config_dir()` otherwise.
+///
+/// Note: `config_dir()` routes interactive root to FHS (`/var/lib/numa`)
+/// so that runtime state like `services.json` stays continuous with the
+/// installed daemon. This helper exists specifically to give advisories
+/// and `load_config` an XDG-aware path for user-authored config, without
+/// moving runtime state out of FHS — see issue #81.
+pub(crate) fn suggested_config_path() -> std::path::PathBuf {
+    #[cfg(not(windows))]
+    {
+        resolve_suggested_config_path(std::env::var("HOME").ok().as_deref(), config_dir)
+    }
+    #[cfg(windows)]
+    {
+        config_dir().join("numa.toml")
+    }
+}
+
+#[cfg(not(windows))]
+fn resolve_suggested_config_path<F>(home: Option<&str>, fallback_dir: F) -> std::path::PathBuf
+where
+    F: FnOnce() -> std::path::PathBuf,
+{
+    if let Some(home) = home {
+        if !home.is_empty() && home != "/" {
+            return std::path::PathBuf::from(home)
+                .join(".config")
+                .join("numa")
+                .join("numa.toml");
+        }
+    }
+    fallback_dir().join("numa.toml")
+}
+
 /// Shared config directory for persistent data (services.json, etc).
 /// Unix users: ~/.config/numa/
 /// Linux root daemon: /var/lib/numa (FHS) — falls back to /usr/local/var/numa
 ///                    if a pre-v0.10.1 install already lives there.
 /// macOS root daemon: /usr/local/var/numa (Homebrew prefix)
-/// Windows: %APPDATA%\numa
+/// Windows: %PROGRAMDATA%\numa (same as data_dir — no per-user config on Windows)
 pub fn config_dir() -> std::path::PathBuf {
     #[cfg(windows)]
     {
-        std::path::PathBuf::from(
-            std::env::var("APPDATA").unwrap_or_else(|_| "C:\\ProgramData".into()),
-        )
-        .join("numa")
+        data_dir()
     }
     #[cfg(not(windows))]
     {
@@ -144,4 +215,73 @@ mod tests {
     fn linux_data_dir_only_fhs_uses_fhs() {
         assert_eq!(resolve_linux_data_dir(false, true), "/var/lib/numa");
     }
+
+    #[cfg(not(windows))]
+    fn fhs() -> std::path::PathBuf {
+        std::path::PathBuf::from("/var/lib/numa")
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn suggested_config_path_prefers_home() {
+        assert_eq!(
+            resolve_suggested_config_path(Some("/home/alice"), fhs),
+            std::path::PathBuf::from("/home/alice/.config/numa/numa.toml"),
+        );
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn suggested_config_path_prefers_root_home_over_fhs() {
+        // Interactive root: HOME=/root is a real user context, not a daemon signal.
+        // Advisory must point where load_config will actually look — issue #81.
+        assert_eq!(
+            resolve_suggested_config_path(Some("/root"), fhs),
+            std::path::PathBuf::from("/root/.config/numa/numa.toml"),
+        );
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn suggested_config_path_falls_back_when_home_unset() {
+        assert_eq!(
+            resolve_suggested_config_path(None, fhs),
+            std::path::PathBuf::from("/var/lib/numa/numa.toml"),
+        );
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn suggested_config_path_falls_back_when_home_is_root() {
+        // systemd services sometimes have HOME=/ — don't treat that as a real home.
+        assert_eq!(
+            resolve_suggested_config_path(Some("/"), fhs),
+            std::path::PathBuf::from("/var/lib/numa/numa.toml"),
+        );
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn suggested_config_path_falls_back_when_home_is_empty() {
+        assert_eq!(
+            resolve_suggested_config_path(Some(""), fhs),
+            std::path::PathBuf::from("/var/lib/numa/numa.toml"),
+        );
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn suggested_config_path_skips_fallback_when_home_valid() {
+        // Happy path shouldn't probe the filesystem via config_dir().
+        let called = std::cell::Cell::new(false);
+        let fallback = || {
+            called.set(true);
+            std::path::PathBuf::from("/should/not/be/used")
+        };
+        let _ = resolve_suggested_config_path(Some("/home/alice"), fallback);
+        assert!(
+            !called.get(),
+            "fallback must not be invoked when HOME is valid"
+        );
+    }
 }

src/main.rs

@@ -1,36 +1,34 @@
-use std::net::SocketAddr;
-use std::sync::{Arc, Mutex, RwLock};
-use std::time::Duration;
-
-use arc_swap::ArcSwap;
-use log::{error, info};
-use tokio::net::UdpSocket;
-
-use numa::blocklist::{download_blocklists, parse_blocklist, BlocklistStore};
-use numa::buffer::BytePacketBuffer;
-use numa::cache::DnsCache;
-use numa::config::{build_zone_map, load_config, ConfigLoad};
-use numa::ctx::{handle_query, ServerCtx};
-use numa::forward::Upstream;
-use numa::override_store::OverrideStore;
-use numa::query_log::QueryLog;
-use numa::service_store::ServiceStore;
-use numa::stats::ServerStats;
 use numa::system_dns::{
-    discover_system_dns, install_service, restart_service, service_status, uninstall_service,
+    install_service, restart_service, service_status, start_service, stop_service,
+    uninstall_service,
 };
 
-const QUAD9_IP: &str = "9.9.9.9";
-const DOH_FALLBACK: &str = "https://9.9.9.9/dns-query";
+fn main() -> numa::Result<()> {
+    // Handle CLI subcommands
+    let arg1 = std::env::args().nth(1).unwrap_or_default();
+
+    #[cfg(windows)]
+    if arg1 == "--service" {
+        // Running under SCM — stderr goes nowhere. Redirect logs to a file.
+        let log_path = numa::data_dir().join("numa.log");
+        let log_file = std::fs::OpenOptions::new()
+            .create(true)
+            .append(true)
+            .open(&log_path)
+            .expect("failed to open log file");
+        env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info"))
+            .format_timestamp_millis()
+            .target(env_logger::Target::Pipe(Box::new(log_file)))
+            .init();
+        numa::windows_service::run_as_service()
+            .map_err(|e| format!("windows service dispatcher failed: {}", e))?;
+        return Ok(());
+    }
 
-#[tokio::main]
-async fn main() -> numa::Result<()> {
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info"))
         .format_timestamp_millis()
         .init();
 
-    // Handle CLI subcommands
-    let arg1 = std::env::args().nth(1).unwrap_or_default();
     match arg1.as_str() {
         "install" => {
             eprintln!("\x1b[1;38;2;192;98;58mNuma\x1b[0m — installing\n");
@@ -44,8 +42,8 @@ async fn main() -> numa::Result<()> {
             let sub = std::env::args().nth(2).unwrap_or_default();
             eprintln!("\x1b[1;38;2;192;98;58mNuma\x1b[0m — service management\n");
             return match sub.as_str() {
-                "start" => install_service().map_err(|e| e.into()),
-                "stop" => uninstall_service().map_err(|e| e.into()),
+                "start" => start_service().map_err(|e| e.into()),
+                "stop" => stop_service().map_err(|e| e.into()),
                 "restart" => restart_service().map_err(|e| e.into()),
                 "status" => service_status().map_err(|e| e.into()),
                 _ => {
@@ -54,6 +52,40 @@ async fn main() -> numa::Result<()> {
                 }
             };
         }
+        "setup-phone" => {
+            let runtime = tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()?;
+            return runtime
+                .block_on(numa::setup_phone::run())
+                .map_err(|e| e.into());
+        }
+        "relay" => {
+            let port: u16 = std::env::args()
+                .nth(2)
+                .as_deref()
+                .and_then(|s| s.parse().ok())
+                .unwrap_or(8443);
+            let bind: std::net::IpAddr = std::env::args()
+                .nth(3)
+                .as_deref()
+                .map(|s| {
+                    s.parse().unwrap_or_else(|e| {
+                        eprintln!("invalid bind address '{}': {}", s, e);
+                        std::process::exit(1);
+                    })
+                })
+                .unwrap_or(std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST));
+            let addr = std::net::SocketAddr::new(bind, port);
+            eprintln!(
+                "\x1b[1;38;2;192;98;58mNuma\x1b[0m — ODoH relay on {}\n",
+                addr
+            );
+            let runtime = tokio::runtime::Builder::new_multi_thread()
+                .enable_all()
+                .build()?;
+            return runtime.block_on(numa::relay::run(addr));
+        }
         "lan" => {
             let sub = std::env::args().nth(2).unwrap_or_default();
             let config_path = std::env::args()
@@ -85,12 +117,29 @@ async fn main() -> numa::Result<()> {
             eprintln!("  service status  Check if the service is running");
             eprintln!("  lan on          Enable LAN service discovery (mDNS)");
             eprintln!("  lan off         Disable LAN service discovery");
+            eprintln!("  relay [PORT] [BIND]");
+            eprintln!("                  Run as an ODoH relay (RFC 9230, default 127.0.0.1:8443)");
+            eprintln!("  setup-phone     Generate a QR code to install Numa DoT on a phone");
             eprintln!("  help            Show this help");
             eprintln!();
             eprintln!("Config path defaults to numa.toml");
             return Ok(());
         }
-        _ => {}
+        _ => {
+            if !arg1.is_empty()
+                && arg1 != "run"
+                && !arg1.contains('/')
+                && !arg1.contains('\\')
+                && !arg1.ends_with(".toml")
+            {
+                eprintln!(
+                    "\x1b[1;38;2;192;98;58mNuma\x1b[0m — unknown command: \x1b[1m{}\x1b[0m\n",
+                    arg1
+                );
+                eprintln!("Run \x1b[1mnuma help\x1b[0m for a list of commands.");
+                std::process::exit(1);
+            }
+        }
     }
 
     let config_path = if arg1.is_empty() || arg1 == "run" {
@@ -100,504 +149,11 @@ async fn main() -> numa::Result<()> {
     } else {
         arg1 // treat as config path for backwards compatibility
     };
-    let ConfigLoad {
-        config,
-        path: resolved_config_path,
-        found: config_found,
-    } = load_config(&config_path)?;
 
-    // Discover system DNS in a single pass (upstream + forwarding rules)
-    let system_dns = discover_system_dns();
-
-    let root_hints = numa::recursive::parse_root_hints(&config.upstream.root_hints);
-
-    let (resolved_mode, upstream_auto, upstream, upstream_label) = match config.upstream.mode {
-        numa::config::UpstreamMode::Auto => {
-            info!("auto mode: probing recursive resolution...");
-            if numa::recursive::probe_recursive(&root_hints).await {
-                info!("recursive probe succeeded — self-sovereign mode");
-                let dummy = Upstream::Udp("0.0.0.0:0".parse().unwrap());
-                (
-                    numa::config::UpstreamMode::Recursive,
-                    false,
-                    dummy,
-                    "recursive (root hints)".to_string(),
-                )
-            } else {
-                log::warn!("recursive probe failed — falling back to Quad9 DoH");
-                let client = reqwest::Client::builder()
-                    .use_rustls_tls()
-                    .build()
-                    .unwrap_or_default();
-                let url = DOH_FALLBACK.to_string();
-                let label = url.clone();
-                (
-                    numa::config::UpstreamMode::Forward,
-                    false,
-                    Upstream::Doh { url, client },
-                    label,
-                )
-            }
-        }
-        numa::config::UpstreamMode::Recursive => {
-            let dummy = Upstream::Udp("0.0.0.0:0".parse().unwrap());
-            (
-                numa::config::UpstreamMode::Recursive,
-                false,
-                dummy,
-                "recursive (root hints)".to_string(),
-            )
-        }
-        numa::config::UpstreamMode::Forward => {
-            let upstream_addr = if config.upstream.address.is_empty() {
-                system_dns
-                    .default_upstream
-                    .or_else(numa::system_dns::detect_dhcp_dns)
-                    .unwrap_or_else(|| {
-                        info!("could not detect system DNS, falling back to Quad9 DoH");
-                        DOH_FALLBACK.to_string()
-                    })
-            } else {
-                config.upstream.address.clone()
-            };
-
-            let upstream: Upstream = if upstream_addr.starts_with("https://") {
-                let client = reqwest::Client::builder()
-                    .use_rustls_tls()
-                    .build()
-                    .unwrap_or_default();
-                Upstream::Doh {
-                    url: upstream_addr,
-                    client,
-                }
-            } else {
-                let addr: SocketAddr =
-                    format!("{}:{}", upstream_addr, config.upstream.port).parse()?;
-                Upstream::Udp(addr)
-            };
-            let label = upstream.to_string();
-            (
-                numa::config::UpstreamMode::Forward,
-                config.upstream.address.is_empty(),
-                upstream,
-                label,
-            )
-        }
-    };
-    let api_port = config.server.api_port;
-
-    let mut blocklist = BlocklistStore::new();
-    for domain in &config.blocking.allowlist {
-        blocklist.add_to_allowlist(domain);
-    }
-    if !config.blocking.enabled {
-        blocklist.set_enabled(false);
-    }
-
-    // Build service store: config services + persisted user services
-    let mut service_store = ServiceStore::new();
-    service_store.insert_from_config("numa", config.server.api_port, Vec::new());
-    for svc in &config.services {
-        service_store.insert_from_config(&svc.name, svc.target_port, svc.routes.clone());
-    }
-    service_store.load_persisted();
-
-    let forwarding_rules = system_dns.forwarding_rules;
-
-    // Resolve data_dir from config, falling back to the platform default.
-    // Used for TLS CA storage below and stored on ServerCtx for runtime use.
-    let resolved_data_dir = config
-        .server
-        .data_dir
-        .clone()
-        .unwrap_or_else(numa::data_dir);
-
-    // Build initial TLS config before ServerCtx (so ArcSwap is ready at construction)
-    let initial_tls = if config.proxy.enabled && config.proxy.tls_port > 0 {
-        let service_names = service_store.names();
-        match numa::tls::build_tls_config(
-            &config.proxy.tld,
-            &service_names,
-            Vec::new(),
-            &resolved_data_dir,
-        ) {
-            Ok(tls_config) => Some(ArcSwap::from(tls_config)),
-            Err(e) => {
-                if let Some(advisory) = numa::tls::try_data_dir_advisory(&e, &resolved_data_dir) {
-                    eprint!("{}", advisory);
-                } else {
-                    log::warn!("TLS setup failed, HTTPS proxy disabled: {}", e);
-                }
-                None
-            }
-        }
-    } else {
-        None
-    };
-
-    let socket = match UdpSocket::bind(&config.server.bind_addr).await {
-        Ok(s) => s,
-        Err(e) => {
-            if let Some(advisory) =
-                numa::system_dns::try_port53_advisory(&config.server.bind_addr, &e)
-            {
-                eprint!("{}", advisory);
-                std::process::exit(1);
-            }
-            return Err(e.into());
-        }
-    };
-
-    let ctx = Arc::new(ServerCtx {
-        socket,
-        zone_map: build_zone_map(&config.zones)?,
-        cache: RwLock::new(DnsCache::new(
-            config.cache.max_entries,
-            config.cache.min_ttl,
-            config.cache.max_ttl,
-        )),
-        stats: Mutex::new(ServerStats::new()),
-        overrides: RwLock::new(OverrideStore::new()),
-        blocklist: RwLock::new(blocklist),
-        query_log: Mutex::new(QueryLog::new(1000)),
-        services: Mutex::new(service_store),
-        lan_peers: Mutex::new(numa::lan::PeerStore::new(config.lan.peer_timeout_secs)),
-        forwarding_rules,
-        upstream: Mutex::new(upstream),
-        upstream_auto,
-        upstream_port: config.upstream.port,
-        lan_ip: Mutex::new(numa::lan::detect_lan_ip().unwrap_or(std::net::Ipv4Addr::LOCALHOST)),
-        timeout: Duration::from_millis(config.upstream.timeout_ms),
-        proxy_tld_suffix: if config.proxy.tld.is_empty() {
-            String::new()
-        } else {
-            format!(".{}", config.proxy.tld)
-        },
-        proxy_tld: config.proxy.tld.clone(),
-        lan_enabled: config.lan.enabled,
-        config_path: resolved_config_path,
-        config_found,
-        config_dir: numa::config_dir(),
-        data_dir: resolved_data_dir,
-        tls_config: initial_tls,
-        upstream_mode: resolved_mode,
-        root_hints,
-        srtt: std::sync::RwLock::new(numa::srtt::SrttCache::new(config.upstream.srtt)),
-        inflight: std::sync::Mutex::new(std::collections::HashMap::new()),
-        dnssec_enabled: config.dnssec.enabled,
-        dnssec_strict: config.dnssec.strict,
-    });
-
-    let zone_count: usize = ctx.zone_map.values().map(|m| m.len()).sum();
-    // Build banner rows, then size the box to fit the longest value
-    let api_url = format!("http://localhost:{}", api_port);
-    let proxy_label = if config.proxy.enabled {
-        if config.proxy.tls_port > 0 {
-            Some(format!(
-                "http://:{} https://:{}",
-                config.proxy.port, config.proxy.tls_port
-            ))
-        } else {
-            Some(format!(
-                "http://*.{} on :{}",
-                config.proxy.tld, config.proxy.port
-            ))
-        }
-    } else {
-        None
-    };
-    let config_label = if ctx.config_found {
-        ctx.config_path.clone()
-    } else {
-        format!("{} (defaults)", ctx.config_path)
-    };
-    let data_label = ctx.data_dir.display().to_string();
-    let services_label = ctx.config_dir.join("services.json").display().to_string();
-
-    // label (10) + value + padding (2) = inner width; minimum 40 for the title row
-    let val_w = [
-        config.server.bind_addr.len(),
-        api_url.len(),
-        upstream_label.len(),
-        config_label.len(),
-        data_label.len(),
-        services_label.len(),
-    ]
-    .into_iter()
-    .chain(proxy_label.as_ref().map(|s| s.len()))
-    .max()
-    .unwrap_or(30);
-    let w = (val_w + 12).max(42); // 10 label + 2 padding, min 42 for title
-
-    let o = "\x1b[38;2;192;98;58m"; // orange
-    let g = "\x1b[38;2;107;124;78m"; // green
-    let d = "\x1b[38;2;163;152;136m"; // dim
-    let r = "\x1b[0m"; // reset
-    let b = "\x1b[1;38;2;192;98;58m"; // bold orange
-    let it = "\x1b[3;38;2;163;152;136m"; // italic dim
-
-    let bar_top = "═".repeat(w);
-    let bar_mid = "─".repeat(w);
-    let row = |label: &str, color: &str, value: &str| {
-        eprintln!(
-            "{o}  ║{r}  {color}{:<9}{r} {:<vw$}{o}║{r}",
-            label,
-            value,
-            vw = w - 12
-        );
-    };
-
-    // Title row: center within the box
-    let title = format!(
-        "{b}NUMA{r}  {it}DNS that governs itself{r}  {d}v{}{r}",
-        env!("CARGO_PKG_VERSION")
-    );
-    // The title contains ANSI codes; visible length is ~38 chars. Pad to fill the box.
-    let title_visible_len = 4 + 2 + 24 + 2 + 1 + env!("CARGO_PKG_VERSION").len() + 1;
-    let title_pad = w.saturating_sub(title_visible_len);
-    eprintln!("\n{o}  ╔{bar_top}╗{r}");
-    eprint!("{o}  ║{r} {title}");
-    eprintln!("{}{o}║{r}", " ".repeat(title_pad));
-    eprintln!("{o}  ╠{bar_top}╣{r}");
-    row("DNS", g, &config.server.bind_addr);
-    row("API", g, &api_url);
-    row("Dashboard", g, &api_url);
-    row(
-        "Upstream",
-        g,
-        if ctx.upstream_mode == numa::config::UpstreamMode::Recursive {
-            "recursive (root hints)"
-        } else {
-            &upstream_label
-        },
-    );
-    row("Zones", g, &format!("{} records", zone_count));
-    row(
-        "Cache",
-        g,
-        &format!("max {} entries", config.cache.max_entries),
-    );
-    row(
-        "Blocking",
-        g,
-        &if config.blocking.enabled {
-            format!("{} lists", config.blocking.lists.len())
-        } else {
-            "disabled".to_string()
-        },
-    );
-    if let Some(ref label) = proxy_label {
-        row("Proxy", g, label);
-        if config.proxy.bind_addr == "127.0.0.1" {
-            let y = "\x1b[38;2;204;176;59m"; // yellow
-            row(
-                "",
-                y,
-                &format!(
-                    "⚠ proxy on 127.0.0.1 — .{} not LAN reachable",
-                    config.proxy.tld
-                ),
-            );
-        }
-    }
-    if config.dot.enabled {
-        row("DoT", g, &format!("tls://:{}", config.dot.port));
-    }
-    if config.lan.enabled {
-        row("LAN", g, "mDNS (_numa._tcp.local)");
-    }
-    if !ctx.forwarding_rules.is_empty() {
-        row(
-            "Routing",
-            g,
-            &format!("{} conditional rules", ctx.forwarding_rules.len()),
-        );
-    }
-    eprintln!("{o}  ╠{bar_mid}╣{r}");
-    row("Config", d, &config_label);
-    row("Data", d, &data_label);
-    row("Services", d, &services_label);
-    eprintln!("{o}  ╚{bar_top}╝{r}\n");
-
-    info!(
-        "numa listening on {}, upstream {}, {} zone records, cache max {}, API on port {}",
-        config.server.bind_addr, upstream_label, zone_count, config.cache.max_entries, api_port,
-    );
-
-    // Download blocklists on startup
-    let blocklist_lists = config.blocking.lists.clone();
-    let refresh_hours = config.blocking.refresh_hours;
-    if config.blocking.enabled && !blocklist_lists.is_empty() {
-        let bl_ctx = Arc::clone(&ctx);
-        let bl_lists = blocklist_lists.clone();
-        tokio::spawn(async move {
-            load_blocklists(&bl_ctx, &bl_lists).await;
-
-            // Periodic refresh
-            let mut interval = tokio::time::interval(Duration::from_secs(refresh_hours * 3600));
-            interval.tick().await; // skip immediate tick
-            loop {
-                interval.tick().await;
-                info!("refreshing blocklists...");
-                load_blocklists(&bl_ctx, &bl_lists).await;
-            }
-        });
-    }
-
-    // Prime TLD cache (recursive mode only)
-    if ctx.upstream_mode == numa::config::UpstreamMode::Recursive {
-        let prime_ctx = Arc::clone(&ctx);
-        let prime_tlds = config.upstream.prime_tlds;
-        tokio::spawn(async move {
-            numa::recursive::prime_tld_cache(
-                &prime_ctx.cache,
-                &prime_ctx.root_hints,
-                &prime_tlds,
-                &prime_ctx.srtt,
-            )
-            .await;
-        });
-    }
-
-    // Spawn HTTP API server
-    let api_ctx = Arc::clone(&ctx);
-    let api_addr: SocketAddr = format!("{}:{}", config.server.api_bind_addr, api_port).parse()?;
-    tokio::spawn(async move {
-        let app = numa::api::router(api_ctx);
-        let listener = tokio::net::TcpListener::bind(api_addr).await.unwrap();
-        info!("HTTP API listening on {}", api_addr);
-        axum::serve(listener, app).await.unwrap();
-    });
-
-    let proxy_bind: std::net::Ipv4Addr = config
-        .proxy
-        .bind_addr
-        .parse()
-        .unwrap_or(std::net::Ipv4Addr::LOCALHOST);
-
-    // Spawn HTTP reverse proxy for .numa domains
-    if config.proxy.enabled {
-        let proxy_ctx = Arc::clone(&ctx);
-        let proxy_port = config.proxy.port;
-        tokio::spawn(async move {
-            numa::proxy::start_proxy(proxy_ctx, proxy_port, proxy_bind).await;
-        });
-    }
-
-    // Spawn HTTPS reverse proxy with TLS termination
-    if config.proxy.enabled && config.proxy.tls_port > 0 && ctx.tls_config.is_some() {
-        let proxy_ctx = Arc::clone(&ctx);
-        let tls_port = config.proxy.tls_port;
-        tokio::spawn(async move {
-            numa::proxy::start_proxy_tls(proxy_ctx, tls_port, proxy_bind).await;
-        });
-    }
-
-    // Spawn network change watcher (upstream re-detection, LAN IP update, peer flush)
-    {
-        let watch_ctx = Arc::clone(&ctx);
-        tokio::spawn(async move {
-            network_watch_loop(watch_ctx).await;
-        });
-    }
-
-    // Spawn LAN service discovery
-    if config.lan.enabled {
-        let lan_ctx = Arc::clone(&ctx);
-        let lan_config = config.lan.clone();
-        tokio::spawn(async move {
-            numa::lan::start_lan_discovery(lan_ctx, &lan_config).await;
-        });
-    }
-
-    // Spawn DNS-over-TLS listener (RFC 7858)
-    if config.dot.enabled {
-        let dot_ctx = Arc::clone(&ctx);
-        let dot_config = config.dot.clone();
-        tokio::spawn(async move {
-            numa::dot::start_dot(dot_ctx, &dot_config).await;
-        });
-    }
-
-    // UDP DNS listener
-    #[allow(clippy::infinite_loop)]
-    loop {
-        let mut buffer = BytePacketBuffer::new();
-        let (_, src_addr) = match ctx.socket.recv_from(&mut buffer.buf).await {
-            Ok(r) => r,
-            Err(e) if e.kind() == std::io::ErrorKind::ConnectionReset => {
-                // Windows delivers ICMP port-unreachable as ConnectionReset on UDP sockets
-                continue;
-            }
-            Err(e) => return Err(e.into()),
-        };
-
-        let ctx = Arc::clone(&ctx);
-        tokio::spawn(async move {
-            if let Err(e) = handle_query(buffer, src_addr, &ctx).await {
-                error!("{} | HANDLER ERROR | {}", src_addr, e);
-            }
-        });
-    }
-}
-
-async fn network_watch_loop(ctx: Arc<numa::ctx::ServerCtx>) {
-    let mut tick: u64 = 0;
-
-    let mut interval = tokio::time::interval(Duration::from_secs(5));
-    interval.tick().await; // skip immediate tick
-
-    loop {
-        interval.tick().await;
-        tick += 1;
-        let mut changed = false;
-
-        // Check LAN IP change (every 5s — cheap, one UDP socket call)
-        if let Some(new_ip) = numa::lan::detect_lan_ip() {
-            let mut current_ip = ctx.lan_ip.lock().unwrap();
-            if new_ip != *current_ip {
-                info!("LAN IP changed: {} → {}", current_ip, new_ip);
-                *current_ip = new_ip;
-                changed = true;
-                numa::recursive::reset_udp_state();
-            }
-        }
-
-        // Re-detect upstream every 30s or on LAN IP change (UDP only —
-        // DoH upstreams are explicitly configured via URL, not auto-detected)
-        if ctx.upstream_auto
-            && matches!(*ctx.upstream.lock().unwrap(), Upstream::Udp(_))
-            && (changed || tick.is_multiple_of(6))
-        {
-            let dns_info = numa::system_dns::discover_system_dns();
-            let new_addr = dns_info
-                .default_upstream
-                .or_else(numa::system_dns::detect_dhcp_dns)
-                .unwrap_or_else(|| QUAD9_IP.to_string());
-            if let Ok(new_sock) =
-                format!("{}:{}", new_addr, ctx.upstream_port).parse::<SocketAddr>()
-            {
-                let new_upstream = Upstream::Udp(new_sock);
-                let mut upstream = ctx.upstream.lock().unwrap();
-                if *upstream != new_upstream {
-                    info!("upstream changed: {} → {}", upstream, new_upstream);
-                    *upstream = new_upstream;
-                    changed = true;
-                }
-            }
-        }
-
-        // Flush stale LAN peers on any network change
-        if changed {
-            ctx.lan_peers.lock().unwrap().clear();
-            info!("flushed LAN peers after network change");
-        }
-
-        // Re-probe UDP every 5 minutes when disabled
-        if tick.is_multiple_of(60) {
-            numa::recursive::probe_udp(&ctx.root_hints).await;
-        }
-    }
+    let runtime = tokio::runtime::Builder::new_multi_thread()
+        .enable_all()
+        .build()?;
+    runtime.block_on(numa::serve::run(config_path))
 }
 
 fn set_lan_enabled(enabled: bool, path: &str) -> numa::Result<()> {
@@ -664,29 +220,3 @@ fn print_lan_status(enabled: bool) {
         eprintln!("  Restart Numa to start mDNS discovery");
     }
 }
-
-async fn load_blocklists(ctx: &ServerCtx, lists: &[String]) {
-    let downloaded = download_blocklists(lists).await;
-
-    // Parse outside the lock to avoid blocking DNS queries during parse (~100ms)
-    let mut all_domains = std::collections::HashSet::new();
-    let mut sources = Vec::new();
-    for (source, text) in &downloaded {
-        let domains = parse_blocklist(text);
-        info!("blocklist: {} domains from {}", domains.len(), source);
-        all_domains.extend(domains);
-        sources.push(source.clone());
-    }
-    let total = all_domains.len();
-
-    // Swap under lock — sub-microsecond
-    ctx.blocklist
-        .write()
-        .unwrap()
-        .swap_domains(all_domains, sources);
-    info!(
-        "blocking enabled: {} unique domains from {} lists",
-        total,
-        downloaded.len()
-    );
-}

src/mobile_api.rs

@@ -0,0 +1,107 @@
+//! Mobile API — persistent HTTP listener for iOS/Android companion apps.
+//!
+//! Read-only subset of Numa's HTTP surface served on a separate port
+//! (default 8765) bound to the LAN. Unlike the main API on port 5380
+//! (which defaults to `127.0.0.1` and serves mutating routes like
+//! `DELETE /services/{name}` or `PUT /blocking/toggle`), this listener
+//! is safe to expose on the LAN because every route is idempotent and
+//! read-only.
+//!
+//! Routes (all GET):
+//!
+//! - `/health` — enriched status + metadata, shares the handler with the
+//!   main API via `crate::api::health`
+//! - `/ca.pem` — Numa local CA in PEM form, shares the handler with the
+//!   main API via `crate::api::serve_ca`
+//! - `/mobileconfig` — combined CA + DNS settings profile (Full mode)
+//! - `/ca.mobileconfig` — CA-only trust profile (no DNS override)
+//!
+//! The mobile API does NOT include the mutating routes (overrides, cache
+//! flush, blocking toggle, service CRUD, etc.). Even if a user sets
+//! `api_bind_addr` to `0.0.0.0` for the main API, those routes stay on
+//! port 5380; the mobile API on port 8765 never serves them. This is the
+//! primary security boundary: anything exposed to the LAN is read-only.
+
+use std::net::Ipv4Addr;
+use std::sync::Arc;
+
+use axum::extract::State;
+use axum::http::{header, StatusCode};
+use axum::response::IntoResponse;
+use axum::routing::get;
+use axum::Router;
+use log::info;
+
+use crate::ctx::ServerCtx;
+use crate::mobileconfig::{build_mobileconfig, ProfileMode};
+
+/// Content-Disposition for the full CA + DNS profile download.
+const FULL_PROFILE_DISPOSITION: &str = "attachment; filename=\"numa.mobileconfig\"";
+
+/// Content-Disposition for the CA-only profile download.
+const CA_ONLY_PROFILE_DISPOSITION: &str = "attachment; filename=\"numa-ca.mobileconfig\"";
+
+/// Build the axum router for the mobile API.
+///
+/// Shares handler functions with the main API where possible (`health`,
+/// `serve_ca`) so the response shapes are identical across both ports.
+pub fn router(ctx: Arc<ServerCtx>) -> Router {
+    Router::new()
+        .route("/health", get(crate::api::health))
+        .route("/ca.pem", get(crate::api::serve_ca))
+        .route("/mobileconfig", get(serve_full_mobileconfig))
+        .route("/ca.mobileconfig", get(serve_ca_only_mobileconfig))
+        .with_state(ctx)
+}
+
+/// Start the mobile API listener on `bind_addr:port`. Runs until the
+/// caller cancels the spawned task. Logs the URL on successful bind.
+pub async fn start(ctx: Arc<ServerCtx>, bind_addr: String, port: u16) -> crate::Result<()> {
+    let addr: std::net::SocketAddr = format!("{}:{}", bind_addr, port).parse()?;
+    let listener = tokio::net::TcpListener::bind(addr).await?;
+
+    info!("Mobile API listening on http://{}", addr);
+
+    let app = router(ctx);
+    axum::serve(listener, app).await?;
+
+    Ok(())
+}
+
+/// Serve the full mobileconfig profile (CA + DNS settings), with the
+/// DNS payload pointing at the current LAN IP. Each request reads the
+/// fresh LAN IP from `ctx.lan_ip` so the profile always reflects the
+/// laptop's current network state.
+async fn serve_full_mobileconfig(
+    State(ctx): State<Arc<ServerCtx>>,
+) -> Result<impl IntoResponse, StatusCode> {
+    let ca_pem = ctx.ca_pem.as_deref().ok_or(StatusCode::NOT_FOUND)?;
+    let lan_ip: Ipv4Addr = *ctx.lan_ip.lock().unwrap();
+    let profile = build_mobileconfig(ProfileMode::Full { lan_ip }, ca_pem);
+    Ok(profile_response(profile, FULL_PROFILE_DISPOSITION))
+}
+
+/// Serve the CA-only mobileconfig profile. Trusts the Numa local CA but
+/// does NOT change the device's DNS settings. Used by the iOS companion
+/// app's DoT mode, where the app configures DNS via `NEDNSSettingsManager`
+/// and only needs the system trust store to accept Numa's self-signed cert.
+async fn serve_ca_only_mobileconfig(
+    State(ctx): State<Arc<ServerCtx>>,
+) -> Result<impl IntoResponse, StatusCode> {
+    let ca_pem = ctx.ca_pem.as_deref().ok_or(StatusCode::NOT_FOUND)?;
+    let profile = build_mobileconfig(ProfileMode::CaOnly, ca_pem);
+    Ok(profile_response(profile, CA_ONLY_PROFILE_DISPOSITION))
+}
+
+/// Shared response constructor for both mobileconfig variants.
+/// Identical headers; only the Content-Disposition filename differs.
+fn profile_response(profile: String, disposition: &'static str) -> impl IntoResponse {
+    (
+        [
+            (header::CONTENT_TYPE, "application/x-apple-aspen-config"),
+            (header::CONTENT_DISPOSITION, disposition),
+            (header::CACHE_CONTROL, "no-store"),
+        ],
+        profile,
+    )
+}

src/mobileconfig.rs

@@ -0,0 +1,305 @@
+//! Apple `.mobileconfig` profile generator.
+//!
+//! Builds iOS Configuration Profiles that Numa serves to phones for one-tap
+//! CA trust and DNS-over-TLS setup. The plist structure is hand-rendered
+//! via `format!` — no plist crate dependency, deterministic output, small
+//! binary footprint.
+//!
+//! Two modes:
+//!
+//! - [`ProfileMode::Full`]: CA trust payload + DNS settings payload pointing
+//!   at a specific LAN IP over DoT. This is what `numa setup-phone` has
+//!   always produced — the user scans a QR, installs this profile, and the
+//!   phone is configured for DoT through Numa in a single step (after the
+//!   iOS Certificate Trust Settings toggle, which is a separate system
+//!   gate we can't bypass).
+//!
+//! - [`ProfileMode::CaOnly`]: CA trust payload only, no DNS settings. Used
+//!   by the future iOS companion app flow where `NEDNSSettingsManager`
+//!   configures DNS programmatically and we only need the system trust
+//!   store to accept Numa's DoT cert. Installing this profile does NOT
+//!   change the user's DNS at all.
+//!
+//! Payload identifiers and UUIDs are fixed (not randomized) so iOS replaces
+//! the existing profile on re-install rather than accumulating duplicates.
+//! The `Full` and `CaOnly` profiles have distinct top-level UUIDs so they
+//! can coexist as separate installed profiles, but they share the same CA
+//! payload UUID since the CA itself is the same trust anchor in both.
+
+use std::net::Ipv4Addr;
+
+/// Top-level UUID and PayloadIdentifier for the full profile (CA + DNS).
+/// Changing this breaks in-place replacement on existing iOS installs.
+const FULL_PROFILE_UUID: &str = "F1E2D3C4-B5A6-7890-1234-567890ABCDEF";
+const FULL_PROFILE_ID: &str = "com.numa.dns.profile";
+
+/// Top-level UUID and PayloadIdentifier for the CA-only profile.
+/// Distinct from `FULL_PROFILE_UUID` so a user can install one, the other,
+/// or both without the latest install silently replacing a different mode.
+const CA_ONLY_PROFILE_UUID: &str = "F2E3D4C5-B6A7-8901-2345-67890ABCDEF0";
+const CA_ONLY_PROFILE_ID: &str = "com.numa.dns.ca.profile";
+
+/// CA trust payload UUID. Same in both modes — iOS will see "the same CA
+/// trust anchor" regardless of which wrapping profile contains it.
+const CA_PAYLOAD_UUID: &str = "B2C3D4E5-F6A7-8901-BCDE-F12345678901";
+const CA_PAYLOAD_ID: &str = "com.numa.dns.ca";
+
+/// DNS settings payload UUID (Full mode only).
+const DNS_PAYLOAD_UUID: &str = "A1B2C3D4-E5F6-7890-ABCD-EF1234567890";
+const DNS_PAYLOAD_ID: &str = "com.numa.dns.dot";
+
+/// Profile mode determines which payloads are included in the generated
+/// `.mobileconfig`.
+#[derive(Debug, Clone)]
+pub enum ProfileMode {
+    /// Full profile: CA trust anchor + managed DNS settings payload
+    /// pointing at the given LAN IP over DoT. This is what the classic
+    /// `numa setup-phone` QR flow serves.
+    Full { lan_ip: Ipv4Addr },
+
+    /// CA-only profile: just the trust anchor, no DNS settings. For use
+    /// with the iOS companion app which manages DNS programmatically via
+    /// `NEDNSSettingsManager` and only needs the system trust store to
+    /// accept Numa's self-signed DoT cert.
+    CaOnly,
+}
+
+/// Build a full `.mobileconfig` profile as an XML plist string.
+pub fn build_mobileconfig(mode: ProfileMode, ca_pem: &str) -> String {
+    let ca_payload = build_ca_payload(ca_pem);
+
+    match mode {
+        ProfileMode::Full { lan_ip } => {
+            let dns_payload = build_dns_payload(lan_ip);
+            let payloads = format!("{}\n{}", ca_payload, dns_payload);
+            let description = format!(
+                "Trusts the Numa local CA and routes DNS queries to Numa over DoT on your local network ({lan_ip})"
+            );
+            wrap_plist(
+                &payloads,
+                FULL_PROFILE_UUID,
+                FULL_PROFILE_ID,
+                &description,
+                "Numa DNS",
+            )
+        }
+        ProfileMode::CaOnly => wrap_plist(
+            &ca_payload,
+            CA_ONLY_PROFILE_UUID,
+            CA_ONLY_PROFILE_ID,
+            "Trusts the Numa local Certificate Authority. Does not change your DNS settings.",
+            "Numa CA",
+        ),
+    }
+}
+
+/// Strip the PEM header/footer and newlines from a CA cert, leaving raw
+/// base64 for embedding in a plist `<data>` block.
+fn pem_to_base64(pem: &str) -> String {
+    pem.lines()
+        .filter(|line| !line.starts_with("-----"))
+        .collect::<String>()
+}
+
+/// Wrap the base64 CA cert at 52 chars per line for plist readability
+/// (matches Apple convention in hand-written profiles).
+fn chunk_base64(base64: &str) -> String {
+    base64
+        .chars()
+        .collect::<Vec<_>>()
+        .chunks(52)
+        .map(|chunk| format!("\t\t\t{}", chunk.iter().collect::<String>()))
+        .collect::<Vec<_>>()
+        .join("\n")
+}
+
+/// Render the `com.apple.security.root` payload dict containing the CA cert.
+fn build_ca_payload(ca_pem: &str) -> String {
+    let ca_wrapped = chunk_base64(&pem_to_base64(ca_pem));
+    format!(
+        r#"		<dict>
+			<key>PayloadCertificateFileName</key>
+			<string>numa-ca.pem</string>
+			<key>PayloadContent</key>
+			<data>
+{ca}
+			</data>
+			<key>PayloadDescription</key>
+			<string>Numa local Certificate Authority — required for DoT trust</string>
+			<key>PayloadDisplayName</key>
+			<string>Numa Local CA</string>
+			<key>PayloadIdentifier</key>
+			<string>{ca_id}</string>
+			<key>PayloadType</key>
+			<string>com.apple.security.root</string>
+			<key>PayloadUUID</key>
+			<string>{ca_uuid}</string>
+			<key>PayloadVersion</key>
+			<integer>1</integer>
+		</dict>"#,
+        ca = ca_wrapped,
+        ca_id = CA_PAYLOAD_ID,
+        ca_uuid = CA_PAYLOAD_UUID,
+    )
+}
+
+/// Render the `com.apple.dnsSettings.managed` payload dict for Full mode.
+fn build_dns_payload(lan_ip: Ipv4Addr) -> String {
+    format!(
+        r#"		<dict>
+			<key>DNSSettings</key>
+			<dict>
+				<key>DNSProtocol</key>
+				<string>TLS</string>
+				<key>ServerAddresses</key>
+				<array>
+					<string>{ip}</string>
+				</array>
+				<key>ServerName</key>
+				<string>numa.numa</string>
+			</dict>
+			<key>OnDemandRules</key>
+			<array>
+				<dict>
+					<key>Action</key>
+					<string>Connect</string>
+					<key>InterfaceTypeMatch</key>
+					<string>WiFi</string>
+				</dict>
+				<dict>
+					<key>Action</key>
+					<string>Disconnect</string>
+				</dict>
+			</array>
+			<key>PayloadDescription</key>
+			<string>Routes DNS queries through Numa over DoT when on Wi-Fi</string>
+			<key>PayloadDisplayName</key>
+			<string>Numa DNS-over-TLS</string>
+			<key>PayloadIdentifier</key>
+			<string>{dns_id}</string>
+			<key>PayloadType</key>
+			<string>com.apple.dnsSettings.managed</string>
+			<key>PayloadUUID</key>
+			<string>{dns_uuid}</string>
+			<key>PayloadVersion</key>
+			<integer>1</integer>
+		</dict>"#,
+        ip = lan_ip,
+        dns_id = DNS_PAYLOAD_ID,
+        dns_uuid = DNS_PAYLOAD_UUID,
+    )
+}
+
+/// Wrap one or more payload dicts in the top-level plist structure
+/// with Configuration type, PayloadContent array, and profile metadata.
+fn wrap_plist(
+    payloads: &str,
+    top_uuid: &str,
+    top_id: &str,
+    description: &str,
+    display_name: &str,
+) -> String {
+    format!(
+        r#"<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>PayloadContent</key>
+	<array>
+{payloads}
+	</array>
+	<key>PayloadDescription</key>
+	<string>{description}</string>
+	<key>PayloadDisplayName</key>
+	<string>{display_name}</string>
+	<key>PayloadIdentifier</key>
+	<string>{top_id}</string>
+	<key>PayloadRemovalDisallowed</key>
+	<false/>
+	<key>PayloadType</key>
+	<string>Configuration</string>
+	<key>PayloadUUID</key>
+	<string>{top_uuid}</string>
+	<key>PayloadVersion</key>
+	<integer>1</integer>
+</dict>
+</plist>
+"#,
+        payloads = payloads,
+        description = description,
+        display_name = display_name,
+        top_id = top_id,
+        top_uuid = top_uuid,
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const SAMPLE_PEM: &str =
+        "-----BEGIN CERTIFICATE-----\nMIIBkDCCATagAwIBAgIUTEST\n-----END CERTIFICATE-----\n";
+
+    #[test]
+    fn pem_to_base64_strips_headers() {
+        let pem = "-----BEGIN CERTIFICATE-----\nABCDEF\nGHIJKL\n-----END CERTIFICATE-----\n";
+        assert_eq!(pem_to_base64(pem), "ABCDEFGHIJKL");
+    }
+
+    #[test]
+    fn full_profile_contains_ip_and_ca() {
+        let config = build_mobileconfig(
+            ProfileMode::Full {
+                lan_ip: Ipv4Addr::new(192, 168, 1, 100),
+            },
+            SAMPLE_PEM,
+        );
+        assert!(config.contains("192.168.1.100"));
+        assert!(config.contains("MIIBkDCCATagAwIBAgIUTEST"));
+        assert!(config.contains("com.apple.security.root"));
+        assert!(config.contains("com.apple.dnsSettings.managed"));
+        assert!(config.contains("DNSProtocol"));
+        assert!(config.contains(FULL_PROFILE_UUID));
+        assert!(config.contains(FULL_PROFILE_ID));
+    }
+
+    #[test]
+    fn ca_only_profile_contains_ca_but_not_dns() {
+        let config = build_mobileconfig(ProfileMode::CaOnly, SAMPLE_PEM);
+        assert!(config.contains("MIIBkDCCATagAwIBAgIUTEST"));
+        assert!(config.contains("com.apple.security.root"));
+        assert!(!config.contains("com.apple.dnsSettings.managed"));
+        assert!(!config.contains("DNSProtocol"));
+        assert!(!config.contains("ServerAddresses"));
+        assert!(config.contains(CA_ONLY_PROFILE_UUID));
+        assert!(config.contains(CA_ONLY_PROFILE_ID));
+    }
+
+    #[test]
+    fn full_and_ca_only_have_distinct_top_uuids() {
+        let full = build_mobileconfig(
+            ProfileMode::Full {
+                lan_ip: Ipv4Addr::new(10, 0, 0, 1),
+            },
+            SAMPLE_PEM,
+        );
+        let ca_only = build_mobileconfig(ProfileMode::CaOnly, SAMPLE_PEM);
+        assert!(full.contains(FULL_PROFILE_UUID));
+        assert!(!full.contains(CA_ONLY_PROFILE_UUID));
+        assert!(ca_only.contains(CA_ONLY_PROFILE_UUID));
+        assert!(!ca_only.contains(FULL_PROFILE_UUID));
+    }
+
+    #[test]
+    fn both_modes_share_ca_payload_uuid() {
+        let full = build_mobileconfig(
+            ProfileMode::Full {
+                lan_ip: Ipv4Addr::new(10, 0, 0, 1),
+            },
+            SAMPLE_PEM,
+        );
+        let ca_only = build_mobileconfig(ProfileMode::CaOnly, SAMPLE_PEM);
+        assert!(full.contains(CA_PAYLOAD_UUID));
+        assert!(ca_only.contains(CA_PAYLOAD_UUID));
+    }
+}

src/odoh.rs

@@ -0,0 +1,489 @@
+//! ODoH target-config fetcher and TTL cache (RFC 9230 §6).
+//!
+//! ## Ciphersuite policy
+//! `odoh-rs` deserialization rejects any config whose KEM/KDF/AEAD triple is
+//! not the mandatory `(X25519, HKDF-SHA256, AES-128-GCM)` (see
+//! `ObliviousDoHConfigContents::deserialize`). This is stricter than the
+//! plan's "pick the mandatory suite if mixed": a response containing *any*
+//! non-mandatory config fails parse entirely. Real-world targets publish a
+//! single mandatory config, so this is fine in practice; revisit if a target
+//! that matters starts mixing suites.
+
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+use arc_swap::ArcSwapOption;
+use odoh_rs::{
+    ObliviousDoHConfigContents, ObliviousDoHConfigs, ObliviousDoHMessage,
+    ObliviousDoHMessagePlaintext,
+};
+use rand_core::{OsRng, TryRngCore};
+use reqwest::header::HeaderMap;
+use tokio::sync::Mutex;
+use tokio::time::timeout;
+
+use crate::Result;
+
+/// MIME type used for both directions of the ODoH exchange (RFC 9230 §4).
+pub(crate) const ODOH_CONTENT_TYPE: &str = "application/oblivious-dns-message";
+
+/// Cap on the response body we read into memory when the relay returns
+/// non-success. Protects against a hostile relay streaming a huge body on
+/// the error path; keeps enough room to carry a human-readable reason.
+const ERROR_BODY_PREVIEW_BYTES: usize = 1024;
+
+/// Fallback TTL when the target's response lacks a usable `Cache-Control`
+/// directive. RFC 9230 §6.2 places no hard floor; 24 h matches what Cloudflare
+/// publishes in practice.
+const DEFAULT_CONFIG_TTL: Duration = Duration::from_secs(24 * 60 * 60);
+
+/// Cap on any TTL we'll honour, regardless of what the target advertises.
+/// Keeps a misconfigured server from pinning an old key indefinitely.
+const MAX_CONFIG_TTL: Duration = Duration::from_secs(7 * 24 * 60 * 60);
+
+/// After a failed `/.well-known/odohconfigs` fetch, refuse to refetch again
+/// within this window — a target that is genuinely broken would otherwise
+/// receive one request per query. Queries that arrive during the backoff
+/// return the cached error immediately.
+const REFRESH_BACKOFF: Duration = Duration::from_secs(60);
+
+/// Parsed ODoH target config plus the freshness metadata needed to age it out.
+#[derive(Debug)]
+pub struct OdohTargetConfig {
+    pub contents: ObliviousDoHConfigContents,
+    pub key_id: Vec<u8>,
+    expires_at: Instant,
+}
+
+impl OdohTargetConfig {
+    pub fn is_expired(&self) -> bool {
+        Instant::now() >= self.expires_at
+    }
+}
+
+struct FailedRefresh {
+    at: Instant,
+    err: String,
+}
+
+/// TTL-gated cache of a single target's HPKE config.
+///
+/// Reads go through `ArcSwapOption` (lock-free hot path). Refreshes serialize
+/// on an async mutex so a burst of simultaneous misses produces a single
+/// outbound fetch, and a failed refresh blocks subsequent refetches for
+/// [`REFRESH_BACKOFF`] to prevent hot-looping against a broken target.
+pub struct OdohConfigCache {
+    target_host: String,
+    configs_url: String,
+    client: reqwest::Client,
+    current: ArcSwapOption<OdohTargetConfig>,
+    last_failure: ArcSwapOption<FailedRefresh>,
+    refresh_lock: Mutex<()>,
+}
+
+impl OdohConfigCache {
+    pub fn new(target_host: String, client: reqwest::Client) -> Self {
+        let configs_url = format!("https://{}/.well-known/odohconfigs", target_host);
+        Self {
+            target_host,
+            configs_url,
+            client,
+            current: ArcSwapOption::from(None),
+            last_failure: ArcSwapOption::from(None),
+            refresh_lock: Mutex::new(()),
+        }
+    }
+
+    pub fn target_host(&self) -> &str {
+        &self.target_host
+    }
+
+    /// Return a valid config, refetching when the cache is cold or expired.
+    /// Within [`REFRESH_BACKOFF`] of a failed refresh, returns the cached
+    /// error without issuing another fetch.
+    pub async fn get(&self) -> Result<Arc<OdohTargetConfig>> {
+        if let Some(cfg) = self.current.load_full() {
+            if !cfg.is_expired() {
+                return Ok(cfg);
+            }
+        }
+
+        if let Some(err) = self.backoff_error() {
+            return Err(err);
+        }
+
+        let _guard = self.refresh_lock.lock().await;
+
+        // Another task may have refreshed or failed while we waited.
+        if let Some(cfg) = self.current.load_full() {
+            if !cfg.is_expired() {
+                return Ok(cfg);
+            }
+        }
+        if let Some(err) = self.backoff_error() {
+            return Err(err);
+        }
+
+        match fetch_odoh_config(&self.client, &self.configs_url).await {
+            Ok(fresh) => {
+                let fresh = Arc::new(fresh);
+                self.current.store(Some(fresh.clone()));
+                self.last_failure.store(None);
+                Ok(fresh)
+            }
+            Err(e) => {
+                let msg = format!("ODoH config fetch failed: {e}");
+                self.last_failure.store(Some(Arc::new(FailedRefresh {
+                    at: Instant::now(),
+                    err: msg.clone(),
+                })));
+                Err(msg.into())
+            }
+        }
+    }
+
+    /// Drop the cached config. Called after the target rejects ciphertext
+    /// (key rotation race) so the next `get()` refetches.
+    pub fn invalidate(&self) {
+        self.current.store(None);
+    }
+
+    fn backoff_error(&self) -> Option<crate::Error> {
+        let fail = self.last_failure.load_full()?;
+        if fail.at.elapsed() < REFRESH_BACKOFF {
+            Some(format!("{} (backoff active)", fail.err).into())
+        } else {
+            None
+        }
+    }
+}
+
+/// Fetch `/.well-known/odohconfigs` from `configs_url` and parse it into an
+/// [`OdohTargetConfig`]. The TTL is taken from the response's
+/// `Cache-Control: max-age=`, clamped to [`DEFAULT_CONFIG_TTL`,
+/// [`MAX_CONFIG_TTL`]] when absent or obviously wrong.
+pub async fn fetch_odoh_config(
+    client: &reqwest::Client,
+    configs_url: &str,
+) -> Result<OdohTargetConfig> {
+    let resp = client.get(configs_url).send().await?.error_for_status()?;
+    let ttl = cache_control_ttl(resp.headers()).unwrap_or(DEFAULT_CONFIG_TTL);
+    let body = resp.bytes().await?;
+    parse_odoh_config(&body, ttl)
+}
+
+fn parse_odoh_config(body: &[u8], ttl: Duration) -> Result<OdohTargetConfig> {
+    let mut buf = body;
+    let configs: ObliviousDoHConfigs = odoh_rs::parse(&mut buf)
+        .map_err(|e| format!("failed to parse ObliviousDoHConfigs: {e}"))?;
+    let first = configs
+        .into_iter()
+        .next()
+        .ok_or("target published no ODoH configs with a supported version + ciphersuite")?;
+    let contents: ObliviousDoHConfigContents = first.into();
+    let key_id = contents
+        .identifier()
+        .map_err(|e| format!("failed to derive key_id from ODoH config: {e}"))?;
+    Ok(OdohTargetConfig {
+        contents,
+        key_id,
+        expires_at: Instant::now() + ttl.min(MAX_CONFIG_TTL),
+    })
+}
+
+/// Send a DNS wire query through an ODoH relay to a target and return the
+/// plaintext DNS wire response.
+///
+/// Flow: fetch the target's HPKE config (cached), seal the query, POST to the
+/// relay with `Targethost`/`Targetpath` headers, then unseal the response.
+/// On seal/unseal failure we invalidate the cache and retry once — this
+/// handles the benign race where the target rotated its key between our
+/// cached config and the POST.
+pub async fn query_through_relay(
+    wire: &[u8],
+    relay_url: &str,
+    target_path: &str,
+    client: &reqwest::Client,
+    cache: &OdohConfigCache,
+    timeout_duration: Duration,
+) -> Result<Vec<u8>> {
+    let req = OdohRequest {
+        wire,
+        relay_url,
+        target_path,
+        client,
+        cache,
+        timeout: timeout_duration,
+    };
+    match attempt_query(&req).await {
+        Ok(v) => Ok(v),
+        Err(AttemptError::KeyRotation(_)) => {
+            cache.invalidate();
+            attempt_query(&req).await.map_err(AttemptError::into_error)
+        }
+        Err(e) => Err(e.into_error()),
+    }
+}
+
+struct OdohRequest<'a> {
+    wire: &'a [u8],
+    relay_url: &'a str,
+    target_path: &'a str,
+    client: &'a reqwest::Client,
+    cache: &'a OdohConfigCache,
+    timeout: Duration,
+}
+
+/// Classification used only by the retry path in [`query_through_relay`].
+enum AttemptError {
+    /// Target signalled the config we used is stale (key rotation race).
+    /// Callers should invalidate the cache and retry exactly once.
+    KeyRotation(String),
+    /// Any other failure — transport, timeout, malformed response.
+    Other(crate::Error),
+}
+
+impl AttemptError {
+    fn into_error(self) -> crate::Error {
+        match self {
+            AttemptError::KeyRotation(m) => format!("ODoH key rotation race: {m}").into(),
+            AttemptError::Other(e) => e,
+        }
+    }
+}
+
+async fn attempt_query(req: &OdohRequest<'_>) -> std::result::Result<Vec<u8>, AttemptError> {
+    let cfg = req.cache.get().await.map_err(AttemptError::Other)?;
+
+    let plaintext = ObliviousDoHMessagePlaintext::new(req.wire, 0);
+    // rand_core 0.9's OsRng is fallible-only; wrap for the infallible bound.
+    let mut os = OsRng;
+    let mut rng = os.unwrap_mut();
+    let (encrypted_query, client_secret) =
+        odoh_rs::encrypt_query(&plaintext, &cfg.contents, &mut rng)
+            .map_err(|e| AttemptError::Other(format!("ODoH encrypt failed: {e}").into()))?;
+    let body = odoh_rs::compose(&encrypted_query)
+        .map_err(|e| AttemptError::Other(format!("ODoH compose failed: {e}").into()))?
+        .freeze();
+
+    // RFC 9230 §5 and the reference client use URL query parameters, not
+    // HTTP headers, to carry the target routing. `Targethost`/`Targetpath`
+    // headers cause relays to treat the request as an unspecified-target and
+    // reject it.
+    let (status, resp_body) = timeout(req.timeout, async {
+        let resp = req
+            .client
+            .post(req.relay_url)
+            .header(reqwest::header::CONTENT_TYPE, ODOH_CONTENT_TYPE)
+            .header(reqwest::header::ACCEPT, ODOH_CONTENT_TYPE)
+            .header(reqwest::header::CACHE_CONTROL, "no-cache, no-store")
+            .query(&[
+                ("targethost", req.cache.target_host()),
+                ("targetpath", req.target_path),
+            ])
+            .body(body)
+            .send()
+            .await?;
+        let status = resp.status();
+        let body = resp.bytes().await?;
+        Ok::<_, reqwest::Error>((status, body))
+    })
+    .await
+    .map_err(|_| AttemptError::Other("ODoH relay request timed out".into()))?
+    .map_err(|e| AttemptError::Other(format!("ODoH relay request failed: {e}").into()))?;
+
+    // RFC 9230 §4.3 expects a target that can't decrypt to reply with a DNS
+    // error in a sealed 200 response; a 401 from the relay/target is the
+    // practical signal that our cached HPKE key is stale. Treat 400 as a
+    // client-side bug (malformed ODoH envelope) — retrying would loop-fail.
+    if !status.is_success() {
+        let preview_len = resp_body.len().min(ERROR_BODY_PREVIEW_BYTES);
+        let body_preview = String::from_utf8_lossy(&resp_body[..preview_len]);
+        let msg = format!("ODoH relay returned {status}: {}", body_preview.trim());
+        return Err(if status.as_u16() == 401 {
+            AttemptError::KeyRotation(msg)
+        } else {
+            AttemptError::Other(msg.into())
+        });
+    }
+
+    let mut buf = resp_body;
+    let encrypted_response: ObliviousDoHMessage = odoh_rs::parse(&mut buf)
+        .map_err(|e| AttemptError::Other(format!("ODoH response parse failed: {e}").into()))?;
+    let plaintext_response =
+        odoh_rs::decrypt_response(&plaintext, &encrypted_response, client_secret)
+            .map_err(|e| AttemptError::KeyRotation(format!("ODoH decrypt failed: {e}")))?;
+
+    Ok(plaintext_response.into_msg().to_vec())
+}
+
+fn cache_control_ttl(headers: &HeaderMap) -> Option<Duration> {
+    let cc = headers.get(reqwest::header::CACHE_CONTROL)?.to_str().ok()?;
+    for directive in cc.split(',') {
+        let directive = directive.trim();
+        if let Some(rest) = directive.strip_prefix("max-age=") {
+            if let Ok(secs) = rest.trim().parse::<u64>() {
+                if secs > 0 {
+                    return Some(Duration::from_secs(secs));
+                }
+            }
+        }
+    }
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use odoh_rs::{ObliviousDoHConfig, ObliviousDoHKeyPair};
+
+    // RFC 9180 HPKE IDs for the sole ODoH mandatory suite:
+    // KEM = X25519, KDF = HKDF-SHA256, AEAD = AES-128-GCM.
+    const KEM_X25519: u16 = 0x0020;
+    const KDF_SHA256: u16 = 0x0001;
+    const AEAD_AES128GCM: u16 = 0x0001;
+
+    fn synth_configs_bytes() -> Vec<u8> {
+        let kp = ObliviousDoHKeyPair::from_parameters(
+            KEM_X25519,
+            KDF_SHA256,
+            AEAD_AES128GCM,
+            &[0u8; 32],
+        );
+        let pk = kp.public().clone();
+        let configs: ObliviousDoHConfigs = vec![ObliviousDoHConfig::from(pk)].into();
+        odoh_rs::compose(&configs).unwrap().to_vec()
+    }
+
+    #[test]
+    fn parse_accepts_well_formed_config() {
+        let bytes = synth_configs_bytes();
+        let cfg = parse_odoh_config(&bytes, Duration::from_secs(3600)).unwrap();
+        assert!(!cfg.key_id.is_empty());
+        assert!(!cfg.is_expired());
+    }
+
+    #[test]
+    fn parse_rejects_garbage() {
+        let bytes = [0xffu8; 16];
+        assert!(parse_odoh_config(&bytes, Duration::from_secs(3600)).is_err());
+    }
+
+    #[test]
+    fn parse_rejects_empty() {
+        assert!(parse_odoh_config(&[], Duration::from_secs(3600)).is_err());
+    }
+
+    #[test]
+    fn ttl_capped_at_max() {
+        let bytes = synth_configs_bytes();
+        let cfg = parse_odoh_config(&bytes, Duration::from_secs(100 * 24 * 60 * 60)).unwrap();
+        let remaining = cfg.expires_at.saturating_duration_since(Instant::now());
+        assert!(remaining <= MAX_CONFIG_TTL);
+        assert!(remaining >= MAX_CONFIG_TTL - Duration::from_secs(1));
+    }
+
+    #[test]
+    fn cache_control_parses_max_age() {
+        let mut h = HeaderMap::new();
+        h.insert("cache-control", "public, max-age=86400".parse().unwrap());
+        assert_eq!(cache_control_ttl(&h), Some(Duration::from_secs(86400)));
+    }
+
+    #[test]
+    fn cache_control_ignores_max_age_zero() {
+        let mut h = HeaderMap::new();
+        h.insert("cache-control", "max-age=0, no-store".parse().unwrap());
+        assert_eq!(cache_control_ttl(&h), None);
+    }
+
+    #[test]
+    fn cache_control_missing_falls_back() {
+        let h = HeaderMap::new();
+        assert_eq!(cache_control_ttl(&h), None);
+    }
+
+    #[test]
+    fn is_expired_tracks_ttl() {
+        let bytes = synth_configs_bytes();
+        let mut cfg = parse_odoh_config(&bytes, Duration::from_secs(3600)).unwrap();
+        assert!(!cfg.is_expired());
+        cfg.expires_at = Instant::now() - Duration::from_secs(1);
+        assert!(cfg.is_expired());
+    }
+
+    #[tokio::test]
+    async fn cache_backoff_blocks_refetch_after_failure() {
+        // Point the cache at a host that does not exist so the fetch fails
+        // deterministically; this exercises the backoff wiring without a
+        // network round-trip succeeding.
+        let cache = OdohConfigCache::new(
+            "odoh-target.invalid".to_string(),
+            reqwest::Client::builder()
+                .timeout(Duration::from_millis(200))
+                .build()
+                .unwrap(),
+        );
+
+        let first = cache.get().await;
+        assert!(first.is_err(), "first fetch must fail against invalid host");
+
+        // Within the backoff window, the cached error is returned immediately.
+        let second = cache.get().await.unwrap_err().to_string();
+        assert!(
+            second.contains("backoff active"),
+            "expected backoff hint, got: {second}"
+        );
+
+        // Reaching past the backoff window allows a fresh attempt — simulate
+        // by rewinding the recorded failure timestamp.
+        cache.last_failure.store(Some(Arc::new(FailedRefresh {
+            at: Instant::now() - (REFRESH_BACKOFF + Duration::from_secs(1)),
+            err: "prior".to_string(),
+        })));
+        let third = cache.get().await.unwrap_err().to_string();
+        assert!(
+            !third.contains("backoff active"),
+            "expected fresh fetch attempt, got: {third}"
+        );
+    }
+
+    /// Round-trip the HPKE seal/unseal path in isolation from HTTP, using the
+    /// odoh-rs primitives that `query_through_relay` wires together. Guards
+    /// against silently breaking the crypto glue if we refactor that path.
+    #[test]
+    fn seal_unseal_round_trip() {
+        use odoh_rs::{decrypt_query, encrypt_response, ResponseNonce};
+
+        let kp = ObliviousDoHKeyPair::from_parameters(
+            KEM_X25519,
+            KDF_SHA256,
+            AEAD_AES128GCM,
+            &[0u8; 32],
+        );
+
+        let query_wire = b"\x12\x34\x01\x00\x00\x01\x00\x00\x00\x00\x00\x00\x07example\x03com\x00\x00\x01\x00\x01";
+        let query_pt = ObliviousDoHMessagePlaintext::new(query_wire, 0);
+        let mut os = OsRng;
+        let mut rng = os.unwrap_mut();
+        let (query_enc, client_secret) =
+            odoh_rs::encrypt_query(&query_pt, kp.public(), &mut rng).unwrap();
+
+        let (query_back, server_secret) = decrypt_query(&query_enc, &kp).unwrap();
+        assert_eq!(query_back.into_msg().as_ref(), query_wire);
+
+        let response_wire = b"\x12\x34\x81\x80\x00\x01\x00\x01\x00\x00\x00\x00";
+        let response_pt = ObliviousDoHMessagePlaintext::new(response_wire, 0);
+        let response_enc = encrypt_response(
+            &query_pt,
+            &response_pt,
+            server_secret,
+            ResponseNonce::default(),
+        )
+        .unwrap();
+
+        let response_back =
+            odoh_rs::decrypt_response(&query_pt, &response_enc, client_secret).unwrap();
+        assert_eq!(response_back.into_msg().as_ref(), response_wire);
+    }
+}

src/packet.rs

@@ -85,6 +85,14 @@ impl DnsPacket {
             + self.edns.as_ref().map_or(0, |e| e.options.capacity())
     }
 
+    /// Apply `f` to every record in the three RR sections (answers,
+    /// authorities, resources). Does not touch questions or edns.
+    pub fn for_each_record_mut(&mut self, mut f: impl FnMut(&mut DnsRecord)) {
+        self.answers.iter_mut().for_each(&mut f);
+        self.authorities.iter_mut().for_each(&mut f);
+        self.resources.iter_mut().for_each(&mut f);
+    }
+
     pub fn response_from(query: &DnsPacket, rescode: crate::header::ResultCode) -> DnsPacket {
         let mut resp = DnsPacket::new();
         resp.header.id = query.header.id;

src/proxy.rs

@@ -4,7 +4,7 @@ use std::sync::Arc;
 use axum::body::Body;
 use axum::extract::{Request, State};
 use axum::response::IntoResponse;
-use axum::routing::any;
+use axum::routing::{any, post};
 use axum::Router;
 use http_body_util::BodyExt;
 use hyper::StatusCode;
@@ -18,6 +18,14 @@ use crate::ctx::ServerCtx;
 
 type HttpClient = Client<hyper_util::client::legacy::connect::HttpConnector, Body>;
 
+/// State passed to the DoH handler. Includes the remote address so
+/// `resolve_query` can log the client IP.
+#[derive(Clone)]
+pub struct DohState {
+    pub ctx: Arc<ServerCtx>,
+    pub remote_addr: Option<std::net::SocketAddr>,
+}
+
 #[derive(Clone)]
 struct ProxyState {
     ctx: Arc<ServerCtx>,
@@ -74,9 +82,17 @@ pub async fn start_proxy_tls(ctx: Arc<ServerCtx>, port: u16, bind_addr: Ipv4Addr
 
     // Hold a separate Arc so we can access tls_config after ctx moves into ProxyState
     let tls_holder = Arc::clone(&ctx);
-    let state = ProxyState { ctx, client };
+    let proxy_state = ProxyState {
+        ctx: Arc::clone(&ctx),
+        client,
+    };
 
-    let app = Router::new().fallback(any(proxy_handler)).with_state(state);
+    // DoH route (RFC 8484) served only on the TLS listener.
+    // DohState.remote_addr is set per-connection below.
+    let doh_state = DohState {
+        ctx,
+        remote_addr: None,
+    };
 
     loop {
         let (tcp_stream, remote_addr) = match listener.accept().await {
@@ -91,7 +107,17 @@ pub async fn start_proxy_tls(ctx: Arc<ServerCtx>, port: u16, bind_addr: Ipv4Addr
         // unwrap safe: guarded by is_none() check above
         let acceptor =
             TlsAcceptor::from(Arc::clone(&*tls_holder.tls_config.as_ref().unwrap().load()));
-        let app = app.clone();
+
+        let mut conn_doh_state = doh_state.clone();
+        conn_doh_state.remote_addr = Some(remote_addr);
+
+        let app = Router::new()
+            .route(
+                "/dns-query",
+                post(crate::doh::doh_post).with_state(conn_doh_state),
+            )
+            .fallback(any(proxy_handler))
+            .with_state(proxy_state.clone());
 
         tokio::spawn(async move {
             let tls_stream = match acceptor.accept(tcp_stream).await {
@@ -232,7 +258,7 @@ pre .str {{ color: #d48a5a }}
     )
 }
 
-fn extract_host(req: &Request) -> Option<String> {
+pub fn extract_host(req: &Request) -> Option<String> {
     req.headers()
         .get(hyper::header::HOST)
         .and_then(|v| v.to_str().ok())

src/query_log.rs

@@ -5,7 +5,7 @@ use std::time::SystemTime;
 use crate::cache::DnssecStatus;
 use crate::header::ResultCode;
 use crate::question::QueryType;
-use crate::stats::QueryPath;
+use crate::stats::{QueryPath, Transport};
 
 pub struct QueryLogEntry {
     pub timestamp: SystemTime,
@@ -13,6 +13,7 @@ pub struct QueryLogEntry {
     pub domain: String,
     pub query_type: QueryType,
     pub path: QueryPath,
+    pub transport: Transport,
     pub rescode: ResultCode,
     pub latency_us: u64,
     pub dnssec: DnssecStatus,
@@ -107,6 +108,7 @@ mod tests {
             domain: "example.com".into(),
             query_type: QueryType::A,
             path: QueryPath::Forwarded,
+            transport: Transport::Udp,
             rescode: ResultCode::NOERROR,
             latency_us: 500,
             dnssec: DnssecStatus::Indeterminate,

src/question.rs

@@ -1,114 +1,66 @@
 use crate::buffer::BytePacketBuffer;
 use crate::Result;
 
-#[derive(PartialEq, Eq, Debug, Clone, Hash, Copy)]
-pub enum QueryType {
-    UNKNOWN(u16),
-    A,      // 1
-    NS,     // 2
-    CNAME,  // 5
-    SOA,    // 6
-    PTR,    // 12
-    MX,     // 15
-    TXT,    // 16
-    AAAA,   // 28
-    SRV,    // 33
-    DS,     // 43
-    RRSIG,  // 46
-    NSEC,   // 47
-    DNSKEY, // 48
-    NSEC3,  // 50
-    OPT,    // 41 (EDNS0 pseudo-type)
-    HTTPS,  // 65
+macro_rules! define_qtypes {
+    ( $( $variant:ident = $num:literal, $str:literal ),* $(,)? ) => {
+        #[derive(PartialEq, Eq, Debug, Clone, Hash, Copy)]
+        pub enum QueryType {
+            UNKNOWN(u16),
+            $( $variant, )*
+        }
+
+        impl QueryType {
+            pub fn to_num(&self) -> u16 {
+                match *self {
+                    QueryType::UNKNOWN(x) => x,
+                    $( QueryType::$variant => $num, )*
+                }
+            }
+
+            pub fn from_num(num: u16) -> QueryType {
+                match num {
+                    $( $num => QueryType::$variant, )*
+                    _ => QueryType::UNKNOWN(num),
+                }
+            }
+
+            pub fn as_str(&self) -> &'static str {
+                match self {
+                    QueryType::UNKNOWN(_) => "UNKNOWN",
+                    $( QueryType::$variant => $str, )*
+                }
+            }
+
+            pub fn parse_str(s: &str) -> Option<QueryType> {
+                match s.to_ascii_uppercase().as_str() {
+                    $( $str => Some(QueryType::$variant), )*
+                    _ => None,
+                }
+            }
+        }
+    };
 }
 
-impl QueryType {
-    pub fn to_num(&self) -> u16 {
-        match *self {
-            QueryType::UNKNOWN(x) => x,
-            QueryType::A => 1,
-            QueryType::NS => 2,
-            QueryType::CNAME => 5,
-            QueryType::SOA => 6,
-            QueryType::PTR => 12,
-            QueryType::MX => 15,
-            QueryType::TXT => 16,
-            QueryType::AAAA => 28,
-            QueryType::SRV => 33,
-            QueryType::OPT => 41,
-            QueryType::DS => 43,
-            QueryType::RRSIG => 46,
-            QueryType::NSEC => 47,
-            QueryType::DNSKEY => 48,
-            QueryType::NSEC3 => 50,
-            QueryType::HTTPS => 65,
-        }
-    }
-
-    pub fn from_num(num: u16) -> QueryType {
-        match num {
-            1 => QueryType::A,
-            2 => QueryType::NS,
-            5 => QueryType::CNAME,
-            6 => QueryType::SOA,
-            12 => QueryType::PTR,
-            15 => QueryType::MX,
-            16 => QueryType::TXT,
-            28 => QueryType::AAAA,
-            33 => QueryType::SRV,
-            41 => QueryType::OPT,
-            43 => QueryType::DS,
-            46 => QueryType::RRSIG,
-            47 => QueryType::NSEC,
-            48 => QueryType::DNSKEY,
-            50 => QueryType::NSEC3,
-            65 => QueryType::HTTPS,
-            _ => QueryType::UNKNOWN(num),
-        }
-    }
-
-    pub fn as_str(&self) -> &'static str {
-        match self {
-            QueryType::A => "A",
-            QueryType::NS => "NS",
-            QueryType::CNAME => "CNAME",
-            QueryType::SOA => "SOA",
-            QueryType::PTR => "PTR",
-            QueryType::MX => "MX",
-            QueryType::TXT => "TXT",
-            QueryType::AAAA => "AAAA",
-            QueryType::SRV => "SRV",
-            QueryType::OPT => "OPT",
-            QueryType::DS => "DS",
-            QueryType::RRSIG => "RRSIG",
-            QueryType::NSEC => "NSEC",
-            QueryType::DNSKEY => "DNSKEY",
-            QueryType::NSEC3 => "NSEC3",
-            QueryType::HTTPS => "HTTPS",
-            QueryType::UNKNOWN(_) => "UNKNOWN",
-        }
-    }
-
-    pub fn parse_str(s: &str) -> Option<QueryType> {
-        match s.to_ascii_uppercase().as_str() {
-            "A" => Some(QueryType::A),
-            "NS" => Some(QueryType::NS),
-            "CNAME" => Some(QueryType::CNAME),
-            "SOA" => Some(QueryType::SOA),
-            "PTR" => Some(QueryType::PTR),
-            "MX" => Some(QueryType::MX),
-            "TXT" => Some(QueryType::TXT),
-            "AAAA" => Some(QueryType::AAAA),
-            "SRV" => Some(QueryType::SRV),
-            "DS" => Some(QueryType::DS),
-            "RRSIG" => Some(QueryType::RRSIG),
-            "DNSKEY" => Some(QueryType::DNSKEY),
-            "NSEC" => Some(QueryType::NSEC),
-            "NSEC3" => Some(QueryType::NSEC3),
-            "HTTPS" => Some(QueryType::HTTPS),
-            _ => None,
-        }
-    }
+define_qtypes! {
+    A      = 1,  "A",
+    NS     = 2,  "NS",
+    CNAME  = 5,  "CNAME",
+    SOA    = 6,  "SOA",
+    PTR    = 12, "PTR",
+    MX     = 15, "MX",
+    TXT    = 16, "TXT",
+    AAAA   = 28, "AAAA",
+    LOC    = 29, "LOC",
+    SRV    = 33, "SRV",
+    NAPTR  = 35, "NAPTR",
+    OPT    = 41, "OPT",
+    DS     = 43, "DS",
+    RRSIG  = 46, "RRSIG",
+    NSEC   = 47, "NSEC",
+    DNSKEY = 48, "DNSKEY",
+    NSEC3  = 50, "NSEC3",
+    SVCB   = 64, "SVCB",
+    HTTPS  = 65, "HTTPS",
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]

src/recursive.rs

@@ -15,8 +15,8 @@ use crate::srtt::SrttCache;
 
 const MAX_REFERRAL_DEPTH: u8 = 10;
 const MAX_CNAME_DEPTH: u8 = 8;
-const NS_QUERY_TIMEOUT: Duration = Duration::from_millis(800);
-const TCP_TIMEOUT: Duration = Duration::from_millis(1500);
+const NS_QUERY_TIMEOUT: Duration = Duration::from_millis(400);
+const TCP_TIMEOUT: Duration = Duration::from_millis(400);
 const UDP_FAIL_THRESHOLD: u8 = 3;
 
 static QUERY_ID: AtomicU16 = AtomicU16::new(1);
@@ -202,23 +202,24 @@ pub(crate) fn resolve_iterative<'a>(
         let mut ns_idx = 0;
 
         for _ in 0..MAX_REFERRAL_DEPTH {
-            let ns_addr = match ns_addrs.get(ns_idx) {
-                Some(addr) => *addr,
-                None => return Err("no nameserver available".into()),
-            };
+            if ns_idx >= ns_addrs.len() {
+                return Err("no nameserver available".into());
+            }
 
             let (q_name, q_type) = minimize_query(qname, qtype, &current_zone);
 
             debug!(
-                "recursive: querying {} for {:?} {} (zone: {}, depth {})",
-                ns_addr, q_type, q_name, current_zone, referral_depth
+                "recursive: querying {} (+ hedge) for {:?} {} (zone: {}, depth {})",
+                ns_addrs[ns_idx], q_type, q_name, current_zone, referral_depth
             );
 
-            let response = match send_query(q_name, q_type, ns_addr, srtt).await {
+            let response = match send_query_hedged(q_name, q_type, &ns_addrs[ns_idx..], srtt).await
+            {
                 Ok(r) => r,
                 Err(e) => {
-                    debug!("recursive: NS {} failed: {}", ns_addr, e);
-                    ns_idx += 1;
+                    debug!("recursive: NS query failed: {}", e);
+                    let remaining = ns_addrs.len().saturating_sub(ns_idx);
+                    ns_idx += remaining.min(2);
                     continue;
                 }
             };
@@ -228,6 +229,9 @@ pub(crate) fn resolve_iterative<'a>(
             {
                 if let Some(zone) = referral_zone(&response) {
                     current_zone = zone;
+                    let mut cache_w = cache.write().unwrap();
+                    cache_ns_delegation(&mut cache_w, &current_zone, &response);
+                    drop(cache_w);
                 }
                 let mut all_ns = extract_ns_from_records(&response.answers);
                 if all_ns.is_empty() {
@@ -296,6 +300,7 @@ pub(crate) fn resolve_iterative<'a>(
 
             {
                 let mut cache_w = cache.write().unwrap();
+                cache_ns_delegation(&mut cache_w, &current_zone, &response);
                 cache_ds_from_authority(&mut cache_w, &response);
             }
             let mut new_ns_addrs = resolve_ns_addrs_from_glue(&response, &ns_names, cache);
@@ -560,6 +565,23 @@ fn cache_ds_from_authority(cache: &mut DnsCache, response: &DnsPacket) {
     }
 }
 
+/// Cache NS delegation records from a referral response so that
+/// `find_closest_ns` can skip re-querying TLD servers on subsequent lookups.
+fn cache_ns_delegation(cache: &mut DnsCache, zone: &str, response: &DnsPacket) {
+    let ns_records: Vec<_> = response
+        .authorities
+        .iter()
+        .filter(|r| matches!(r, DnsRecord::NS { .. }))
+        .cloned()
+        .collect();
+    if ns_records.is_empty() {
+        return;
+    }
+    let mut pkt = make_glue_packet();
+    pkt.answers = ns_records;
+    cache.insert(zone, QueryType::NS, &pkt);
+}
+
 fn make_glue_packet() -> DnsPacket {
     let mut pkt = DnsPacket::new();
     pkt.header.response = true;
@@ -587,6 +609,115 @@ async fn tcp_with_srtt(
     }
 }
 
+/// Smart NS query: fire to two servers simultaneously when SRTT is unknown
+/// (cold queries), or to the best server with SRTT-based hedge when known.
+async fn send_query_hedged(
+    qname: &str,
+    qtype: QueryType,
+    servers: &[SocketAddr],
+    srtt: &RwLock<SrttCache>,
+) -> crate::Result<DnsPacket> {
+    if servers.is_empty() {
+        return Err("no nameserver available".into());
+    }
+    if servers.len() == 1 {
+        return send_query(qname, qtype, servers[0], srtt).await;
+    }
+
+    let primary = servers[0];
+    let secondary = servers[1];
+    let primary_known = srtt.read().unwrap().is_known(primary.ip());
+
+    if !primary_known {
+        // Cold: fire both simultaneously, first response wins
+        debug!(
+            "recursive: parallel query to {} and {} for {:?} {}",
+            primary, secondary, qtype, qname
+        );
+        let fut_a = send_query(qname, qtype, primary, srtt);
+        let fut_b = send_query(qname, qtype, secondary, srtt);
+        tokio::pin!(fut_a);
+        tokio::pin!(fut_b);
+
+        // First Ok wins. If one errors, wait for the other.
+        let mut a_done = false;
+        let mut b_done = false;
+        let mut a_err: Option<crate::Error> = None;
+        let mut b_err: Option<crate::Error> = None;
+
+        loop {
+            tokio::select! {
+                r = &mut fut_a, if !a_done => {
+                    match r {
+                        Ok(resp) => return Ok(resp),
+                        Err(e) => { a_done = true; a_err = Some(e); }
+                    }
+                }
+                r = &mut fut_b, if !b_done => {
+                    match r {
+                        Ok(resp) => return Ok(resp),
+                        Err(e) => { b_done = true; b_err = Some(e); }
+                    }
+                }
+            }
+            match (a_err.take(), b_err.take()) {
+                (Some(e), Some(_)) => return Err(e),
+                (a, b) => {
+                    a_err = a;
+                    b_err = b;
+                }
+            }
+        }
+    } else {
+        // Warm: send to best, hedge after SRTT × 3 if slow
+        let hedge_ms = srtt.read().unwrap().get(primary.ip()) * 3;
+        let hedge_delay = Duration::from_millis(hedge_ms.max(50));
+
+        let fut_a = send_query(qname, qtype, primary, srtt);
+        tokio::pin!(fut_a);
+        let delay = tokio::time::sleep(hedge_delay);
+        tokio::pin!(delay);
+
+        tokio::select! {
+            r = &mut fut_a => return r,
+            _ = &mut delay => {}
+        }
+
+        debug!(
+            "recursive: hedging {} -> {} after {}ms for {:?} {}",
+            primary, secondary, hedge_ms, qtype, qname
+        );
+        let fut_b = send_query(qname, qtype, secondary, srtt);
+        tokio::pin!(fut_b);
+
+        // First Ok wins; if one errors, wait for the other.
+        let mut a_err: Option<crate::Error> = None;
+        let mut b_err: Option<crate::Error> = None;
+        loop {
+            tokio::select! {
+                r = &mut fut_a, if a_err.is_none() => {
+                    match r {
+                        Ok(resp) => return Ok(resp),
+                        Err(e) => {
+                            if b_err.is_some() { return Err(e); }
+                            a_err = Some(e);
+                        }
+                    }
+                }
+                r = &mut fut_b, if b_err.is_none() => {
+                    match r {
+                        Ok(resp) => return Ok(resp),
+                        Err(e) => {
+                            if let Some(ae) = a_err.take() { return Err(ae); }
+                            b_err = Some(e);
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
 async fn send_query(
     qname: &str,
     qtype: QueryType,
@@ -634,9 +765,13 @@ async fn send_query(
                     "send_query: {} consecutive UDP failures — switching to TCP-first",
                     fails
                 );
+                // Now that UDP is disabled, retry this query via TCP
+                return tcp_with_srtt(&query, server, srtt, start).await;
             }
-            debug!("send_query: UDP failed for {}: {}, trying TCP", server, e);
-            tcp_with_srtt(&query, server, srtt, start).await
+            // UDP works in general (priming succeeded) but this server timed out.
+            // Don't waste another 400ms on TCP — the server is unreachable.
+            srtt.write().unwrap().record_failure(server.ip());
+            Err(e)
         }
     }
 }
@@ -678,6 +813,10 @@ mod tests {
     use super::*;
     use std::net::{Ipv4Addr, Ipv6Addr};
 
+    /// Tests that mutate the global UDP_DISABLED / UDP_FAILURES flags must hold
+    /// this lock to avoid racing with each other under `cargo test` parallelism.
+    static UDP_STATE_LOCK: std::sync::Mutex<()> = std::sync::Mutex::new(());
+
     #[test]
     fn extract_ns_from_authority() {
         let mut pkt = DnsPacket::new();
@@ -916,10 +1055,11 @@ mod tests {
     }
 
     /// TCP-only server returns authoritative answer directly.
-    /// Verifies: UDP fails → TCP fallback → resolves.
+    /// Verifies: when UDP is disabled, TCP-first resolves.
     #[tokio::test]
     async fn tcp_fallback_resolves_when_udp_blocked() {
-        UDP_DISABLED.store(false, Ordering::Relaxed);
+        let _guard = UDP_STATE_LOCK.lock().unwrap();
+        UDP_DISABLED.store(true, Ordering::Relaxed);
         UDP_FAILURES.store(0, Ordering::Release);
 
         let server_addr = spawn_tcp_dns_server(|query| {
@@ -950,49 +1090,32 @@ mod tests {
         }
     }
 
-    /// Full iterative resolution through TCP-only mock: root referral → authoritative answer.
-    /// The mock plays both roles (returns referral for NS queries, answer for A queries).
+    /// TCP round-trip through mock: query → authoritative answer via forward_tcp.
+    /// Uses forward_tcp directly to avoid dependence on the global UDP_DISABLED flag
+    /// which is shared across concurrent tests.
     #[tokio::test]
     async fn tcp_only_iterative_resolution() {
-        UDP_DISABLED.store(true, Ordering::Release); // Skip UDP entirely for speed
-
         let server_addr = spawn_tcp_dns_server(|query| {
             let q = match query.questions.first() {
                 Some(q) => q,
                 None => return DnsPacket::response_from(query, ResultCode::SERVFAIL),
             };
 
-            if q.qtype == QueryType::NS || q.name == "com" {
-                // Return referral — NS points back to ourselves (same IP, port 53 in glue
-                // won't work, but cache will have our address from root_hints)
-                let mut resp = DnsPacket::new();
-                resp.header.id = query.header.id;
-                resp.header.response = true;
-                resp.header.rescode = ResultCode::NOERROR;
-                resp.questions = query.questions.clone();
-                resp.authorities.push(DnsRecord::NS {
-                    domain: "com".into(),
-                    host: "ns1.com".into(),
-                    ttl: 3600,
-                });
-                resp
-            } else {
-                // Return authoritative answer
-                let mut resp = DnsPacket::response_from(query, ResultCode::NOERROR);
-                resp.header.authoritative_answer = true;
-                resp.answers.push(DnsRecord::A {
-                    domain: q.name.clone(),
-                    addr: Ipv4Addr::new(10, 0, 0, 42),
-                    ttl: 300,
-                });
-                resp
-            }
+            let mut resp = DnsPacket::response_from(query, ResultCode::NOERROR);
+            resp.header.authoritative_answer = true;
+            resp.answers.push(DnsRecord::A {
+                domain: q.name.clone(),
+                addr: Ipv4Addr::new(10, 0, 0, 42),
+                ttl: 300,
+            });
+            resp
         })
         .await;
 
-        let srtt = RwLock::new(SrttCache::new(true));
-        let result = send_query("hello.example.com", QueryType::A, server_addr, &srtt).await;
-        let resp = result.expect("TCP-only send_query should work");
+        let query = DnsPacket::query(0x1234, "hello.example.com", QueryType::A);
+        let resp = crate::forward::forward_tcp(&query, server_addr, TCP_TIMEOUT)
+            .await
+            .expect("TCP query should work");
         assert_eq!(resp.header.rescode, ResultCode::NOERROR);
         match &resp.answers[0] {
             DnsRecord::A { addr, .. } => assert_eq!(*addr, Ipv4Addr::new(10, 0, 0, 42)),
@@ -1002,7 +1125,8 @@ mod tests {
 
     #[tokio::test]
     async fn tcp_fallback_handles_nxdomain() {
-        UDP_DISABLED.store(false, Ordering::Relaxed);
+        let _guard = UDP_STATE_LOCK.lock().unwrap();
+        UDP_DISABLED.store(true, Ordering::Relaxed);
         UDP_FAILURES.store(0, Ordering::Release);
 
         let server_addr = spawn_tcp_dns_server(|query| {
@@ -1034,6 +1158,7 @@ mod tests {
 
     #[tokio::test]
     async fn udp_auto_disable_resets() {
+        let _guard = UDP_STATE_LOCK.lock().unwrap();
         UDP_DISABLED.store(true, Ordering::Release);
         UDP_FAILURES.store(5, Ordering::Relaxed);
 

src/relay.rs

@@ -0,0 +1,342 @@
+//! ODoH relay (RFC 9230 §5) — the forward-without-reading half of the
+//! protocol. Runs `numa relay`; skips all resolver initialisation (no port
+//! 53, no cache, no recursion, no dashboard). The relay never reads the
+//! HPKE-sealed payload and keeps no per-request logs — only aggregate
+//! counters.
+
+use std::net::SocketAddr;
+use std::sync::atomic::{AtomicU64, Ordering};
+use std::sync::Arc;
+use std::time::Duration;
+
+use axum::body::Bytes;
+use axum::extract::{DefaultBodyLimit, Query, State};
+use axum::http::{header, StatusCode};
+use axum::response::{IntoResponse, Response};
+use axum::routing::{get, post};
+use axum::Router;
+use log::{error, info};
+use serde::Deserialize;
+use tokio::net::TcpListener;
+
+use crate::forward::build_https_client_with_pool;
+use crate::odoh::ODOH_CONTENT_TYPE;
+use crate::Result;
+
+/// Cap on the opaque body we accept from a client. ODoH envelopes are
+/// ~100–300 bytes in practice; anything larger is malformed or hostile.
+const MAX_BODY_BYTES: usize = 4 * 1024;
+
+/// Cap on the body we read back from the target before streaming to client.
+/// Slightly larger: target responses carry DNS answers plus HPKE overhead.
+const MAX_TARGET_RESPONSE_BYTES: usize = 8 * 1024;
+
+/// Covers the whole client-to-target round trip — not just `.send()` — so a
+/// slow-drip target can't hang a worker indefinitely after headers arrive.
+const TARGET_REQUEST_TIMEOUT: Duration = Duration::from_secs(5);
+
+/// The relay hits many distinct target hosts on behalf of clients. A
+/// per-host idle pool of 4 keeps warm TLS connections available for concurrent
+/// fan-out without blowing up memory on a small VPS.
+const RELAY_POOL_PER_HOST: usize = 4;
+
+#[derive(Deserialize)]
+struct RelayParams {
+    targethost: String,
+    targetpath: String,
+}
+
+struct RelayState {
+    client: reqwest::Client,
+    total_requests: AtomicU64,
+    forwarded_ok: AtomicU64,
+    forwarded_err: AtomicU64,
+    rejected_bad_request: AtomicU64,
+}
+
+impl RelayState {
+    fn new() -> Arc<Self> {
+        Arc::new(RelayState {
+            client: build_https_client_with_pool(RELAY_POOL_PER_HOST),
+            total_requests: AtomicU64::new(0),
+            forwarded_ok: AtomicU64::new(0),
+            forwarded_err: AtomicU64::new(0),
+            rejected_bad_request: AtomicU64::new(0),
+        })
+    }
+}
+
+/// `DefaultBodyLimit` overrides axum's 2 MiB default so hostile clients
+/// can't force the relay to buffer multi-MB bodies before our own cap.
+fn build_app(state: Arc<RelayState>) -> Router {
+    Router::new()
+        .route("/relay", post(handle_relay))
+        .layer(DefaultBodyLimit::max(MAX_BODY_BYTES))
+        .route("/health", get(handle_health))
+        .with_state(state)
+}
+
+pub async fn run(addr: SocketAddr) -> Result<()> {
+    let app = build_app(RelayState::new());
+    let listener = TcpListener::bind(addr).await?;
+    info!("ODoH relay listening on {}", addr);
+    axum::serve(listener, app).await?;
+    Ok(())
+}
+
+async fn handle_health(State(state): State<Arc<RelayState>>) -> impl IntoResponse {
+    let body = format!(
+        "ok\ntotal {}\nforwarded_ok {}\nforwarded_err {}\nrejected_bad_request {}\n",
+        state.total_requests.load(Ordering::Relaxed),
+        state.forwarded_ok.load(Ordering::Relaxed),
+        state.forwarded_err.load(Ordering::Relaxed),
+        state.rejected_bad_request.load(Ordering::Relaxed),
+    );
+    (
+        StatusCode::OK,
+        [(header::CONTENT_TYPE, "text/plain; charset=utf-8")],
+        body,
+    )
+}
+
+async fn handle_relay(
+    State(state): State<Arc<RelayState>>,
+    Query(params): Query<RelayParams>,
+    headers: axum::http::HeaderMap,
+    body: Bytes,
+) -> Response {
+    state.total_requests.fetch_add(1, Ordering::Relaxed);
+
+    if !content_type_matches(&headers, ODOH_CONTENT_TYPE) {
+        state.rejected_bad_request.fetch_add(1, Ordering::Relaxed);
+        return (
+            StatusCode::UNSUPPORTED_MEDIA_TYPE,
+            "expected application/oblivious-dns-message",
+        )
+            .into_response();
+    }
+
+    if body.len() > MAX_BODY_BYTES {
+        state.rejected_bad_request.fetch_add(1, Ordering::Relaxed);
+        return (StatusCode::PAYLOAD_TOO_LARGE, "body exceeds 4 KiB cap").into_response();
+    }
+
+    if !is_valid_hostname(&params.targethost) || !params.targetpath.starts_with('/') {
+        state.rejected_bad_request.fetch_add(1, Ordering::Relaxed);
+        return (StatusCode::BAD_REQUEST, "invalid targethost or targetpath").into_response();
+    }
+
+    let target_url = format!("https://{}{}", params.targethost, params.targetpath);
+    match forward_to_target(&state.client, &target_url, body).await {
+        Ok((status, resp_body)) => {
+            state.forwarded_ok.fetch_add(1, Ordering::Relaxed);
+            (
+                status,
+                [(header::CONTENT_TYPE, ODOH_CONTENT_TYPE)],
+                resp_body,
+            )
+                .into_response()
+        }
+        Err(e) => {
+            // Log the underlying reason for operators; don't leak reqwest
+            // internals (which can reveal the target's TLS config, IP, etc.)
+            // back to arbitrary clients.
+            error!("relay forward to {} failed: {}", target_url, e);
+            state.forwarded_err.fetch_add(1, Ordering::Relaxed);
+            (StatusCode::BAD_GATEWAY, "target unreachable").into_response()
+        }
+    }
+}
+
+async fn forward_to_target(
+    client: &reqwest::Client,
+    url: &str,
+    body: Bytes,
+) -> Result<(StatusCode, Bytes)> {
+    let response = tokio::time::timeout(TARGET_REQUEST_TIMEOUT, async {
+        let resp = client
+            .post(url)
+            .header(header::CONTENT_TYPE, ODOH_CONTENT_TYPE)
+            .header(header::ACCEPT, ODOH_CONTENT_TYPE)
+            .body(body)
+            .send()
+            .await?;
+        let status = StatusCode::from_u16(resp.status().as_u16())?;
+        let resp_body = resp.bytes().await?;
+        Ok::<_, crate::Error>((status, resp_body))
+    })
+    .await
+    .map_err(|_| "timed out talking to target")??;
+
+    if response.1.len() > MAX_TARGET_RESPONSE_BYTES {
+        return Err("target response exceeds cap".into());
+    }
+    Ok(response)
+}
+
+fn content_type_matches(headers: &axum::http::HeaderMap, expected: &str) -> bool {
+    headers
+        .get(header::CONTENT_TYPE)
+        .and_then(|v| v.to_str().ok())
+        .map(|ct| ct.split(';').next().unwrap_or("").trim() == expected)
+        .unwrap_or(false)
+}
+
+/// Strict DNS-hostname validator, aimed at closing the SSRF surface a naive
+/// `contains('.')` check leaves open (e.g. `example.com@internal.host`,
+/// `evil.com/../admin`). Requires ASCII letters/digits/dot/dash, at least
+/// one dot, no leading dot or dash, length ≤ 253 per RFC 1035.
+fn is_valid_hostname(h: &str) -> bool {
+    if h.is_empty() || h.len() > 253 || !h.contains('.') {
+        return false;
+    }
+    if h.starts_with('.') || h.starts_with('-') || h.ends_with('.') || h.ends_with('-') {
+        return false;
+    }
+    h.chars()
+        .all(|c| c.is_ascii_alphanumeric() || c == '.' || c == '-')
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    async fn spawn_relay() -> (SocketAddr, Arc<RelayState>) {
+        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener.local_addr().unwrap();
+
+        let state = RelayState::new();
+        let app = build_app(state.clone());
+
+        tokio::spawn(async move {
+            let _ = axum::serve(listener, app).await;
+        });
+        (addr, state)
+    }
+
+    #[tokio::test]
+    async fn rejects_missing_content_type() {
+        let (addr, state) = spawn_relay().await;
+        let client = reqwest::Client::new();
+        let resp = client
+            .post(format!(
+                "http://{}/relay?targethost=odoh.example.com&targetpath=/dns-query",
+                addr
+            ))
+            .body("body")
+            .send()
+            .await
+            .unwrap();
+        assert_eq!(resp.status(), reqwest::StatusCode::UNSUPPORTED_MEDIA_TYPE);
+        assert_eq!(state.rejected_bad_request.load(Ordering::Relaxed), 1);
+    }
+
+    #[tokio::test]
+    async fn rejects_oversized_body() {
+        let (addr, _state) = spawn_relay().await;
+        let big = vec![0u8; MAX_BODY_BYTES + 1];
+        let client = reqwest::Client::new();
+        let resp = client
+            .post(format!(
+                "http://{}/relay?targethost=odoh.example.com&targetpath=/dns-query",
+                addr
+            ))
+            .header(header::CONTENT_TYPE, ODOH_CONTENT_TYPE)
+            .body(big)
+            .send()
+            .await
+            .unwrap();
+        // axum's DefaultBodyLimit rejects before our handler runs, so the
+        // counter doesn't increment — but the status code proves the layer
+        // enforced the cap. Either status is acceptable evidence.
+        assert!(matches!(
+            resp.status(),
+            reqwest::StatusCode::PAYLOAD_TOO_LARGE | reqwest::StatusCode::BAD_REQUEST
+        ));
+    }
+
+    #[tokio::test]
+    async fn rejects_targethost_without_dot() {
+        let (addr, state) = spawn_relay().await;
+        let client = reqwest::Client::new();
+        let resp = client
+            .post(format!(
+                "http://{}/relay?targethost=localhost&targetpath=/dns-query",
+                addr
+            ))
+            .header(header::CONTENT_TYPE, ODOH_CONTENT_TYPE)
+            .body("body")
+            .send()
+            .await
+            .unwrap();
+        assert_eq!(resp.status(), reqwest::StatusCode::BAD_REQUEST);
+        assert_eq!(state.rejected_bad_request.load(Ordering::Relaxed), 1);
+    }
+
+    #[tokio::test]
+    async fn rejects_userinfo_ssrf_attempt() {
+        let (addr, state) = spawn_relay().await;
+        let client = reqwest::Client::new();
+        // The naive contains('.') check would let this through and reqwest
+        // would route to `internal.host` using `evil.com` as userinfo.
+        let resp = client
+            .post(format!(
+                "http://{}/relay?targethost=evil.com@internal.host&targetpath=/dns-query",
+                addr
+            ))
+            .header(header::CONTENT_TYPE, ODOH_CONTENT_TYPE)
+            .body("body")
+            .send()
+            .await
+            .unwrap();
+        assert_eq!(resp.status(), reqwest::StatusCode::BAD_REQUEST);
+        assert_eq!(state.rejected_bad_request.load(Ordering::Relaxed), 1);
+    }
+
+    #[tokio::test]
+    async fn rejects_targetpath_without_leading_slash() {
+        let (addr, state) = spawn_relay().await;
+        let client = reqwest::Client::new();
+        let resp = client
+            .post(format!(
+                "http://{}/relay?targethost=odoh.example.com&targetpath=dns-query",
+                addr
+            ))
+            .header(header::CONTENT_TYPE, ODOH_CONTENT_TYPE)
+            .body("body")
+            .send()
+            .await
+            .unwrap();
+        assert_eq!(resp.status(), reqwest::StatusCode::BAD_REQUEST);
+        assert_eq!(state.rejected_bad_request.load(Ordering::Relaxed), 1);
+    }
+
+    #[tokio::test]
+    async fn health_endpoint_reports_counters() {
+        let (addr, _state) = spawn_relay().await;
+        let client = reqwest::Client::new();
+        let resp = client
+            .get(format!("http://{}/health", addr))
+            .send()
+            .await
+            .unwrap();
+        assert_eq!(resp.status(), reqwest::StatusCode::OK);
+        let body = resp.text().await.unwrap();
+        assert!(body.contains("ok\n"));
+        assert!(body.contains("forwarded_ok 0"));
+    }
+
+    #[test]
+    fn hostname_validator_accepts_and_rejects() {
+        assert!(is_valid_hostname("odoh.cloudflare-dns.com"));
+        assert!(is_valid_hostname("a.b"));
+        assert!(!is_valid_hostname(""));
+        assert!(!is_valid_hostname("localhost"));
+        assert!(!is_valid_hostname(".leading.dot"));
+        assert!(!is_valid_hostname("trailing.dot."));
+        assert!(!is_valid_hostname("-leading.dash"));
+        assert!(!is_valid_hostname("evil.com@internal.host"));
+        assert!(!is_valid_hostname("evil.com/../admin"));
+        assert!(!is_valid_hostname(&"a".repeat(254)));
+    }
+}

src/serve.rs

@@ -0,0 +1,665 @@
+//! The main DNS-server runtime.
+//!
+//! Extracted from `main.rs` so both the interactive CLI entry and the
+//! Windows service dispatcher (`windows_service` module) can drive the
+//! same startup/serve loop.
+
+use std::net::SocketAddr;
+use std::sync::{Arc, Mutex, RwLock};
+use std::time::Duration;
+
+use arc_swap::ArcSwap;
+use log::{error, info};
+use tokio::net::UdpSocket;
+
+use crate::blocklist::{download_blocklists, parse_blocklist, BlocklistStore};
+use crate::buffer::BytePacketBuffer;
+use crate::cache::DnsCache;
+use crate::config::{build_zone_map, load_config, ConfigLoad};
+use crate::ctx::{handle_query, ServerCtx};
+use crate::forward::{
+    build_https_client, build_odoh_client, parse_upstream_list, Upstream, UpstreamPool,
+};
+use crate::odoh::OdohConfigCache;
+use crate::override_store::OverrideStore;
+use crate::query_log::QueryLog;
+use crate::service_store::ServiceStore;
+use crate::stats::{ServerStats, Transport};
+use crate::system_dns::discover_system_dns;
+
+const QUAD9_IP: &str = "9.9.9.9";
+const DOH_FALLBACK: &str = "https://9.9.9.9/dns-query";
+
+/// Boot the DNS server and run until the UDP listener errors out.
+pub async fn run(config_path: String) -> crate::Result<()> {
+    let ConfigLoad {
+        config,
+        path: resolved_config_path,
+        found: config_found,
+    } = load_config(&config_path)?;
+
+    // Discover system DNS in a single pass (upstream + forwarding rules)
+    let system_dns = discover_system_dns();
+
+    let root_hints = crate::recursive::parse_root_hints(&config.upstream.root_hints);
+
+    let recursive_pool = || {
+        let dummy = UpstreamPool::new(vec![Upstream::Udp("0.0.0.0:0".parse().unwrap())], vec![]);
+        (dummy, "recursive (root hints)".to_string())
+    };
+
+    let (resolved_mode, upstream_auto, pool, upstream_label) = match config.upstream.mode {
+        crate::config::UpstreamMode::Auto => {
+            info!("auto mode: probing recursive resolution...");
+            if crate::recursive::probe_recursive(&root_hints).await {
+                info!("recursive probe succeeded — self-sovereign mode");
+                let (pool, label) = recursive_pool();
+                (crate::config::UpstreamMode::Recursive, false, pool, label)
+            } else {
+                log::warn!("recursive probe failed — falling back to Quad9 DoH");
+                let client = build_https_client();
+                let url = DOH_FALLBACK.to_string();
+                let label = url.clone();
+                let pool = UpstreamPool::new(vec![Upstream::Doh { url, client }], vec![]);
+                (crate::config::UpstreamMode::Forward, false, pool, label)
+            }
+        }
+        crate::config::UpstreamMode::Recursive => {
+            let (pool, label) = recursive_pool();
+            (crate::config::UpstreamMode::Recursive, false, pool, label)
+        }
+        crate::config::UpstreamMode::Forward => {
+            let addrs = if config.upstream.address.is_empty() {
+                let detected = system_dns
+                    .default_upstream
+                    .or_else(crate::system_dns::detect_dhcp_dns)
+                    .unwrap_or_else(|| {
+                        info!("could not detect system DNS, falling back to Quad9 DoH");
+                        DOH_FALLBACK.to_string()
+                    });
+                vec![detected]
+            } else {
+                config.upstream.address.clone()
+            };
+
+            let primary = parse_upstream_list(&addrs, config.upstream.port)?;
+            let fallback = parse_upstream_list(&config.upstream.fallback, config.upstream.port)?;
+
+            let pool = UpstreamPool::new(primary, fallback);
+            let label = pool.label();
+            (
+                crate::config::UpstreamMode::Forward,
+                config.upstream.address.is_empty(),
+                pool,
+                label,
+            )
+        }
+        crate::config::UpstreamMode::Odoh => {
+            let odoh = config.upstream.odoh_upstream()?;
+            let client = build_odoh_client(&odoh);
+            let target_config = Arc::new(OdohConfigCache::new(
+                odoh.target_host.clone(),
+                client.clone(),
+            ));
+            let primary = vec![Upstream::Odoh {
+                relay_url: odoh.relay_url,
+                target_path: odoh.target_path,
+                client,
+                target_config,
+            }];
+            let fallback = if odoh.strict {
+                Vec::new()
+            } else {
+                parse_upstream_list(&config.upstream.fallback, config.upstream.port)?
+            };
+            let pool = UpstreamPool::new(primary, fallback);
+            let label = pool.label();
+            (crate::config::UpstreamMode::Odoh, false, pool, label)
+        }
+    };
+    let api_port = config.server.api_port;
+
+    let mut blocklist = BlocklistStore::new();
+    for domain in &config.blocking.allowlist {
+        blocklist.add_to_allowlist(domain);
+    }
+    if !config.blocking.enabled {
+        blocklist.set_enabled(false);
+    }
+
+    // Build service store: config services + persisted user services
+    let mut service_store = ServiceStore::new();
+    service_store.insert_from_config("numa", config.server.api_port, Vec::new());
+    for svc in &config.services {
+        service_store.insert_from_config(&svc.name, svc.target_port, svc.routes.clone());
+    }
+    service_store.load_persisted();
+
+    for fwd in &config.forwarding {
+        for suffix in &fwd.suffix {
+            info!(
+                "forwarding .{} to {} (config rule)",
+                suffix,
+                fwd.upstream.join(", ")
+            );
+        }
+    }
+    let forwarding_rules =
+        crate::config::merge_forwarding_rules(&config.forwarding, system_dns.forwarding_rules)?;
+
+    // Resolve data_dir from config, falling back to the platform default.
+    // Used for TLS CA storage below and stored on ServerCtx for runtime use.
+    let resolved_data_dir = config
+        .server
+        .data_dir
+        .clone()
+        .unwrap_or_else(crate::data_dir);
+
+    // Build initial TLS config before ServerCtx (so ArcSwap is ready at construction)
+    let initial_tls = if config.proxy.enabled && config.proxy.tls_port > 0 {
+        let service_names = service_store.names();
+        match crate::tls::build_tls_config(
+            &config.proxy.tld,
+            &service_names,
+            Vec::new(),
+            &resolved_data_dir,
+        ) {
+            Ok(tls_config) => Some(ArcSwap::from(tls_config)),
+            Err(e) => {
+                if let Some(advisory) = crate::tls::try_data_dir_advisory(&e, &resolved_data_dir) {
+                    eprint!("{}", advisory);
+                } else {
+                    log::warn!("TLS setup failed, HTTPS proxy disabled: {}", e);
+                }
+                None
+            }
+        }
+    } else {
+        None
+    };
+
+    let doh_enabled = initial_tls.is_some();
+    let health_meta = crate::health::HealthMeta::build(
+        &resolved_data_dir,
+        config.dot.enabled,
+        config.dot.port,
+        config.mobile.port,
+        config.dnssec.enabled,
+        resolved_mode == crate::config::UpstreamMode::Recursive,
+        config.lan.enabled,
+        config.blocking.enabled,
+        doh_enabled,
+    );
+
+    let ca_pem = std::fs::read_to_string(resolved_data_dir.join("ca.pem")).ok();
+
+    let socket = match UdpSocket::bind(&config.server.bind_addr).await {
+        Ok(s) => s,
+        Err(e) => {
+            if let Some(advisory) =
+                crate::system_dns::try_port53_advisory(&config.server.bind_addr, &e)
+            {
+                eprint!("{}", advisory);
+                std::process::exit(1);
+            }
+            return Err(e.into());
+        }
+    };
+
+    let ctx = Arc::new(ServerCtx {
+        socket,
+        zone_map: build_zone_map(&config.zones)?,
+        cache: RwLock::new(DnsCache::new(
+            config.cache.max_entries,
+            config.cache.min_ttl,
+            config.cache.max_ttl,
+        )),
+        refreshing: Mutex::new(std::collections::HashSet::new()),
+        stats: Mutex::new(ServerStats::new()),
+        overrides: RwLock::new(OverrideStore::new()),
+        blocklist: RwLock::new(blocklist),
+        query_log: Mutex::new(QueryLog::new(1000)),
+        services: Mutex::new(service_store),
+        lan_peers: Mutex::new(crate::lan::PeerStore::new(config.lan.peer_timeout_secs)),
+        forwarding_rules,
+        upstream_pool: Mutex::new(pool),
+        upstream_auto,
+        upstream_port: config.upstream.port,
+        lan_ip: Mutex::new(crate::lan::detect_lan_ip().unwrap_or(std::net::Ipv4Addr::LOCALHOST)),
+        timeout: Duration::from_millis(config.upstream.timeout_ms),
+        hedge_delay: resolved_mode.hedge_delay(config.upstream.hedge_ms),
+        proxy_tld_suffix: if config.proxy.tld.is_empty() {
+            String::new()
+        } else {
+            format!(".{}", config.proxy.tld)
+        },
+        proxy_tld: config.proxy.tld.clone(),
+        lan_enabled: config.lan.enabled,
+        config_path: resolved_config_path,
+        config_found,
+        config_dir: crate::config_dir(),
+        data_dir: resolved_data_dir,
+        tls_config: initial_tls,
+        upstream_mode: resolved_mode,
+        root_hints,
+        srtt: std::sync::RwLock::new(crate::srtt::SrttCache::new(config.upstream.srtt)),
+        inflight: std::sync::Mutex::new(std::collections::HashMap::new()),
+        dnssec_enabled: config.dnssec.enabled,
+        dnssec_strict: config.dnssec.strict,
+        health_meta,
+        ca_pem,
+        mobile_enabled: config.mobile.enabled,
+        mobile_port: config.mobile.port,
+        filter_aaaa: config.server.filter_aaaa,
+    });
+
+    let zone_count: usize = ctx.zone_map.values().map(|m| m.len()).sum();
+    // Build banner rows, then size the box to fit the longest value
+    let api_url = format!("http://localhost:{}", api_port);
+    let proxy_label = if config.proxy.enabled {
+        if config.proxy.tls_port > 0 {
+            Some(format!(
+                "http://:{} https://:{}",
+                config.proxy.port, config.proxy.tls_port
+            ))
+        } else {
+            Some(format!(
+                "http://*.{} on :{}",
+                config.proxy.tld, config.proxy.port
+            ))
+        }
+    } else {
+        None
+    };
+    let config_label = if ctx.config_found {
+        ctx.config_path.clone()
+    } else {
+        format!("{} (defaults)", ctx.config_path)
+    };
+    let data_label = ctx.data_dir.display().to_string();
+    let services_label = ctx.config_dir.join("services.json").display().to_string();
+
+    // label (10) + value + padding (2) = inner width; minimum 40 for the title row
+    let val_w = [
+        config.server.bind_addr.len(),
+        api_url.len(),
+        upstream_label.len(),
+        config_label.len(),
+        data_label.len(),
+        services_label.len(),
+    ]
+    .into_iter()
+    .chain(proxy_label.as_ref().map(|s| s.len()))
+    .max()
+    .unwrap_or(30);
+    let w = (val_w + 12).max(42); // 10 label + 2 padding, min 42 for title
+
+    let o = "\x1b[38;2;192;98;58m"; // orange
+    let g = "\x1b[38;2;107;124;78m"; // green
+    let d = "\x1b[38;2;163;152;136m"; // dim
+    let r = "\x1b[0m"; // reset
+    let b = "\x1b[1;38;2;192;98;58m"; // bold orange
+    let it = "\x1b[3;38;2;163;152;136m"; // italic dim
+
+    let bar_top = "═".repeat(w);
+    let bar_mid = "─".repeat(w);
+    let row = |label: &str, color: &str, value: &str| {
+        eprintln!(
+            "{o}  ║{r}  {color}{:<9}{r} {:<vw$}{o}║{r}",
+            label,
+            value,
+            vw = w - 12
+        );
+    };
+
+    // Title row: center within the box
+    let title = format!(
+        "{b}NUMA{r}  {it}DNS that governs itself{r}  {d}v{}{r}",
+        env!("CARGO_PKG_VERSION")
+    );
+    // The title contains ANSI codes; visible length is ~38 chars. Pad to fill the box.
+    let title_visible_len = 4 + 2 + 24 + 2 + 1 + env!("CARGO_PKG_VERSION").len() + 1;
+    let title_pad = w.saturating_sub(title_visible_len);
+    eprintln!("\n{o}  ╔{bar_top}╗{r}");
+    eprint!("{o}  ║{r} {title}");
+    eprintln!("{}{o}║{r}", " ".repeat(title_pad));
+    eprintln!("{o}  ╠{bar_top}╣{r}");
+    row("DNS", g, &config.server.bind_addr);
+    row("API", g, &api_url);
+    row("Dashboard", g, &api_url);
+    row(
+        "Upstream",
+        g,
+        if ctx.upstream_mode == crate::config::UpstreamMode::Recursive {
+            "recursive (root hints)"
+        } else {
+            &upstream_label
+        },
+    );
+    row("Zones", g, &format!("{} records", zone_count));
+    row(
+        "Cache",
+        g,
+        &format!("max {} entries", config.cache.max_entries),
+    );
+    if !config.cache.warm.is_empty() {
+        row("Warm", g, &format!("{} domains", config.cache.warm.len()));
+    }
+    row(
+        "Blocking",
+        g,
+        &if config.blocking.enabled {
+            format!("{} lists", config.blocking.lists.len())
+        } else {
+            "disabled".to_string()
+        },
+    );
+    if let Some(ref label) = proxy_label {
+        row("Proxy", g, label);
+        if config.proxy.bind_addr == "127.0.0.1" {
+            let y = "\x1b[38;2;204;176;59m"; // yellow
+            row(
+                "",
+                y,
+                &format!(
+                    "⚠ proxy on 127.0.0.1 — .{} not LAN reachable",
+                    config.proxy.tld
+                ),
+            );
+        }
+    }
+    if config.dot.enabled {
+        row("DoT", g, &format!("tls://:{}", config.dot.port));
+    }
+    if doh_enabled {
+        row(
+            "DoH",
+            g,
+            &format!("https://:{}/dns-query", config.proxy.tls_port),
+        );
+    }
+    if config.lan.enabled {
+        row("LAN", g, "mDNS (_numa._tcp.local)");
+    }
+    if !ctx.forwarding_rules.is_empty() {
+        row(
+            "Routing",
+            g,
+            &format!("{} conditional rules", ctx.forwarding_rules.len()),
+        );
+    }
+    eprintln!("{o}  ╠{bar_mid}╣{r}");
+    row("Config", d, &config_label);
+    row("Data", d, &data_label);
+    row("Services", d, &services_label);
+    eprintln!("{o}  ╚{bar_top}╝{r}\n");
+
+    info!(
+        "numa listening on {}, upstream {}, {} zone records, cache max {}, API on port {}",
+        config.server.bind_addr, upstream_label, zone_count, config.cache.max_entries, api_port,
+    );
+
+    // Download blocklists on startup
+    let blocklist_lists = config.blocking.lists.clone();
+    let refresh_hours = config.blocking.refresh_hours;
+    if config.blocking.enabled && !blocklist_lists.is_empty() {
+        let bl_ctx = Arc::clone(&ctx);
+        let bl_lists = blocklist_lists.clone();
+        tokio::spawn(async move {
+            load_blocklists(&bl_ctx, &bl_lists).await;
+
+            // Periodic refresh
+            let mut interval = tokio::time::interval(Duration::from_secs(refresh_hours * 3600));
+            interval.tick().await; // skip immediate tick
+            loop {
+                interval.tick().await;
+                info!("refreshing blocklists...");
+                load_blocklists(&bl_ctx, &bl_lists).await;
+            }
+        });
+    }
+
+    // Prime TLD cache (recursive mode only)
+    if ctx.upstream_mode == crate::config::UpstreamMode::Recursive {
+        let prime_ctx = Arc::clone(&ctx);
+        let prime_tlds = config.upstream.prime_tlds;
+        tokio::spawn(async move {
+            crate::recursive::prime_tld_cache(
+                &prime_ctx.cache,
+                &prime_ctx.root_hints,
+                &prime_tlds,
+                &prime_ctx.srtt,
+            )
+            .await;
+        });
+    }
+
+    // Spawn cache warming for user-configured domains
+    if !config.cache.warm.is_empty() {
+        let warm_ctx = Arc::clone(&ctx);
+        let warm_domains = config.cache.warm.clone();
+        tokio::spawn(async move {
+            cache_warm_loop(warm_ctx, warm_domains).await;
+        });
+    }
+
+    // Spawn DoH connection keepalive — prevents idle TLS teardown
+    {
+        let keepalive_ctx = Arc::clone(&ctx);
+        tokio::spawn(async move {
+            doh_keepalive_loop(keepalive_ctx).await;
+        });
+    }
+
+    // Spawn HTTP API server
+    let api_ctx = Arc::clone(&ctx);
+    let api_addr: SocketAddr = format!("{}:{}", config.server.api_bind_addr, api_port).parse()?;
+    tokio::spawn(async move {
+        let app = crate::api::router(api_ctx);
+        let listener = tokio::net::TcpListener::bind(api_addr).await.unwrap();
+        info!("HTTP API listening on {}", api_addr);
+        axum::serve(listener, app).await.unwrap();
+    });
+
+    // Spawn Mobile API listener (read-only subset for iOS/Android companion
+    // apps, LAN-bound by default so phones can reach it). Only idempotent
+    // GETs; no state-mutating routes are exposed here regardless of
+    // the main API's bind address.
+    if config.mobile.enabled {
+        let mobile_ctx = Arc::clone(&ctx);
+        let mobile_bind = config.mobile.bind_addr.clone();
+        let mobile_port = config.mobile.port;
+        tokio::spawn(async move {
+            if let Err(e) = crate::mobile_api::start(mobile_ctx, mobile_bind, mobile_port).await {
+                log::warn!("Mobile API listener failed: {}", e);
+            }
+        });
+    }
+
+    let proxy_bind: std::net::Ipv4Addr = config
+        .proxy
+        .bind_addr
+        .parse()
+        .unwrap_or(std::net::Ipv4Addr::LOCALHOST);
+
+    // Spawn HTTP reverse proxy for .numa domains
+    if config.proxy.enabled {
+        let proxy_ctx = Arc::clone(&ctx);
+        let proxy_port = config.proxy.port;
+        tokio::spawn(async move {
+            crate::proxy::start_proxy(proxy_ctx, proxy_port, proxy_bind).await;
+        });
+    }
+
+    // Spawn HTTPS reverse proxy with TLS termination
+    if config.proxy.enabled && config.proxy.tls_port > 0 && ctx.tls_config.is_some() {
+        let proxy_ctx = Arc::clone(&ctx);
+        let tls_port = config.proxy.tls_port;
+        tokio::spawn(async move {
+            crate::proxy::start_proxy_tls(proxy_ctx, tls_port, proxy_bind).await;
+        });
+    }
+
+    // Spawn network change watcher (upstream re-detection, LAN IP update, peer flush)
+    {
+        let watch_ctx = Arc::clone(&ctx);
+        tokio::spawn(async move {
+            network_watch_loop(watch_ctx).await;
+        });
+    }
+
+    // Spawn LAN service discovery
+    if config.lan.enabled {
+        let lan_ctx = Arc::clone(&ctx);
+        let lan_config = config.lan.clone();
+        tokio::spawn(async move {
+            crate::lan::start_lan_discovery(lan_ctx, &lan_config).await;
+        });
+    }
+
+    // Spawn DNS-over-TLS listener (RFC 7858)
+    if config.dot.enabled {
+        let dot_ctx = Arc::clone(&ctx);
+        let dot_config = config.dot.clone();
+        tokio::spawn(async move {
+            crate::dot::start_dot(dot_ctx, &dot_config).await;
+        });
+    }
+
+    // UDP DNS listener
+    #[allow(clippy::infinite_loop)]
+    loop {
+        let mut buffer = BytePacketBuffer::new();
+        let (len, src_addr) = match ctx.socket.recv_from(&mut buffer.buf).await {
+            Ok(r) => r,
+            Err(e) if e.kind() == std::io::ErrorKind::ConnectionReset => {
+                // Windows delivers ICMP port-unreachable as ConnectionReset on UDP sockets
+                continue;
+            }
+            Err(e) => return Err(e.into()),
+        };
+        let ctx = Arc::clone(&ctx);
+        tokio::spawn(async move {
+            if let Err(e) = handle_query(buffer, len, src_addr, &ctx, Transport::Udp).await {
+                error!("{} | HANDLER ERROR | {}", src_addr, e);
+            }
+        });
+    }
+}
+
+async fn network_watch_loop(ctx: Arc<ServerCtx>) {
+    let mut tick: u64 = 0;
+
+    let mut interval = tokio::time::interval(Duration::from_secs(5));
+    interval.tick().await; // skip immediate tick
+
+    loop {
+        interval.tick().await;
+        tick += 1;
+        let mut changed = false;
+
+        // Check LAN IP change (every 5s — cheap, one UDP socket call)
+        if let Some(new_ip) = crate::lan::detect_lan_ip() {
+            let mut current_ip = ctx.lan_ip.lock().unwrap();
+            if new_ip != *current_ip {
+                info!("LAN IP changed: {} → {}", current_ip, new_ip);
+                *current_ip = new_ip;
+                changed = true;
+                crate::recursive::reset_udp_state();
+            }
+        }
+
+        // Re-detect upstream every 30s or on LAN IP change (auto-detect only)
+        if ctx.upstream_auto && (changed || tick.is_multiple_of(6)) {
+            let dns_info = crate::system_dns::discover_system_dns();
+            let new_addr = dns_info
+                .default_upstream
+                .or_else(crate::system_dns::detect_dhcp_dns)
+                .unwrap_or_else(|| QUAD9_IP.to_string());
+            let mut pool = ctx.upstream_pool.lock().unwrap();
+            if pool.maybe_update_primary(&new_addr, ctx.upstream_port) {
+                info!("upstream changed → {}", pool.label());
+                changed = true;
+            }
+        }
+
+        // Flush stale LAN peers on any network change
+        if changed {
+            ctx.lan_peers.lock().unwrap().clear();
+            info!("flushed LAN peers after network change");
+        }
+
+        // Re-probe UDP every 5 minutes when disabled
+        if tick.is_multiple_of(60) {
+            crate::recursive::probe_udp(&ctx.root_hints).await;
+        }
+    }
+}
+
+async fn load_blocklists(ctx: &ServerCtx, lists: &[String]) {
+    let downloaded = download_blocklists(lists).await;
+
+    // Parse outside the lock to avoid blocking DNS queries during parse (~100ms)
+    let mut all_domains = std::collections::HashSet::new();
+    let mut sources = Vec::new();
+    for (source, text) in &downloaded {
+        let domains = parse_blocklist(text);
+        info!("blocklist: {} domains from {}", domains.len(), source);
+        all_domains.extend(domains);
+        sources.push(source.clone());
+    }
+    let total = all_domains.len();
+
+    // Swap under lock — sub-microsecond
+    ctx.blocklist
+        .write()
+        .unwrap()
+        .swap_domains(all_domains, sources);
+    info!(
+        "blocking enabled: {} unique domains from {} lists",
+        total,
+        downloaded.len()
+    );
+}
+
+async fn warm_domain(ctx: &ServerCtx, domain: &str) {
+    for qtype in [
+        crate::question::QueryType::A,
+        crate::question::QueryType::AAAA,
+    ] {
+        crate::ctx::refresh_entry(ctx, domain, qtype).await;
+    }
+}
+
+async fn doh_keepalive_loop(ctx: Arc<ServerCtx>) {
+    let mut interval = tokio::time::interval(Duration::from_secs(25));
+    interval.tick().await; // skip first immediate tick
+    loop {
+        interval.tick().await;
+        let pool = ctx.upstream_pool.lock().unwrap().clone();
+        if let Some(upstream) = pool.preferred() {
+            crate::forward::keepalive_doh(upstream).await;
+        }
+    }
+}
+
+async fn cache_warm_loop(ctx: Arc<ServerCtx>, domains: Vec<String>) {
+    tokio::time::sleep(Duration::from_secs(2)).await;
+
+    for domain in &domains {
+        warm_domain(&ctx, domain).await;
+    }
+    info!("cache warm: {} domains resolved at startup", domains.len());
+
+    let mut interval = tokio::time::interval(Duration::from_secs(30));
+    interval.tick().await;
+    loop {
+        interval.tick().await;
+        for domain in &domains {
+            let refresh = ctx.cache.read().unwrap().needs_warm(domain);
+            if refresh {
+                warm_domain(&ctx, domain).await;
+            }
+        }
+    }
+}

src/setup_phone.rs

@@ -0,0 +1,126 @@
+//! `numa setup-phone` CLI — thin QR wrapper over the persistent mobile API.
+//!
+//! Before the mobile API existed, this command spawned its own one-shot
+//! HTTP server on port 8765 to serve a freshly-generated mobileconfig
+//! for a single download. That role now belongs to
+//! [`crate::mobile_api`], which runs persistently alongside the main
+//! API and serves `/mobileconfig` at the same port whenever Numa is
+//! running.
+//!
+//! This command is now a thin terminal-side wrapper:
+//!
+//!   1. Detect the current LAN IP
+//!   2. Render a terminal QR code pointing at
+//!      `http://<lan_ip>:8765/mobileconfig`
+//!   3. Print install instructions and exit
+//!
+//! The user scans the QR, iOS fetches the profile from the mobile API
+//! (which is always up as long as `numa` is running), installs, and the
+//! user walks through Settings → Certificate Trust Settings to enable
+//! trust.
+//!
+//! Numa must be running for the profile download to succeed; if the
+//! mobile API is not listening on port 8765, the download will fail
+//! and the user will see Safari's "Cannot Connect to Server" error.
+//! The CLI prints a reminder about this at the bottom of the output.
+
+use qrcode::render::unicode;
+use qrcode::QrCode;
+
+/// Default port where the persistent mobile API serves `/mobileconfig`.
+/// Matches `MobileConfig::default().port` in `config.rs`. If the user
+/// has overridden `[mobile] port = N` in `numa.toml`, they'll need to
+/// adjust the URL manually — this CLI uses the default without parsing
+/// `numa.toml`.
+const SETUP_PORT: u16 = 8765;
+
+fn render_qr(url: &str) -> Result<String, String> {
+    let code = QrCode::new(url).map_err(|e| format!("failed to encode QR: {}", e))?;
+    Ok(code
+        .render::<unicode::Dense1x2>()
+        .dark_color(unicode::Dense1x2::Light)
+        .light_color(unicode::Dense1x2::Dark)
+        .build())
+}
+
+/// Run the `numa setup-phone` flow.
+pub async fn run() -> Result<(), String> {
+    let lan_ip = crate::lan::detect_lan_ip()
+        .ok_or("could not detect LAN IP — are you connected to a network?")?;
+
+    let addr = std::net::SocketAddr::from(([127, 0, 0, 1], SETUP_PORT));
+    let api_reachable = tokio::time::timeout(
+        std::time::Duration::from_millis(500),
+        tokio::net::TcpStream::connect(addr),
+    )
+    .await
+    .map(|r| r.is_ok())
+    .unwrap_or(false);
+
+    if !api_reachable {
+        eprintln!();
+        eprintln!(
+            "  \x1b[1;38;2;192;98;58mNuma\x1b[0m — mobile API is not reachable on port {}.",
+            SETUP_PORT
+        );
+        eprintln!();
+        eprintln!("  The phone won't be able to download the profile until the mobile");
+        eprintln!("  API is running. Add this to your numa.toml and restart Numa:");
+        eprintln!();
+        eprintln!("    [mobile]");
+        eprintln!("    enabled = true");
+        eprintln!();
+        return Err("mobile API not running".into());
+    }
+
+    let url = format!("http://{}:{}/mobileconfig", lan_ip, SETUP_PORT);
+    let qr = render_qr(&url)?;
+
+    eprintln!();
+    eprintln!("  \x1b[1;38;2;192;98;58mNuma Phone Setup\x1b[0m");
+    eprintln!();
+    eprintln!("  Profile URL: \x1b[36m{}\x1b[0m", url);
+    eprintln!();
+    for line in qr.lines() {
+        eprintln!("  {}", line);
+    }
+    eprintln!();
+    eprintln!("  \x1b[1mOn your iPhone:\x1b[0m");
+    eprintln!("    1. Open Camera, point at the QR code, tap the yellow banner");
+    eprintln!("    2. Allow the download when Safari asks");
+    eprintln!("    3. Open Settings — tap \"Profile Downloaded\" near the top");
+    eprintln!("       (or: Settings → General → VPN & Device Management → Numa DNS)");
+    eprintln!("    4. Tap Install (top right), enter passcode, Install again");
+    eprintln!("    5. \x1b[1mSettings → General → About → Certificate Trust Settings\x1b[0m");
+    eprintln!("       Toggle ON \"Numa Local CA\" — required for DoT to work");
+    eprintln!();
+    eprintln!(
+        "  \x1b[33mNote:\x1b[0m profile uses your laptop's current IP ({}). If your",
+        lan_ip
+    );
+    eprintln!("  laptop changes networks, re-scan this QR — iOS will replace the");
+    eprintln!("  existing profile automatically (fixed UUID).");
+    eprintln!();
+    eprintln!(
+        "  \x1b[90mThe profile is served by Numa's persistent mobile API on port {}.\x1b[0m",
+        SETUP_PORT
+    );
+    eprintln!("  \x1b[90mMake sure `numa` is running before scanning. If it's not,\x1b[0m");
+    eprintln!("  \x1b[90mstart it with `sudo numa install` or run it interactively.\x1b[0m");
+    eprintln!();
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn render_qr_produces_unicode() {
+        let qr = render_qr("http://192.168.1.9:8765/mobileconfig").unwrap();
+        assert!(!qr.is_empty());
+        // Dense1x2 uses these block characters
+        assert!(qr.chars().any(|c| matches!(c, '█' | '▀' | '▄' | ' ')));
+    }
+}

src/srtt.rs

@@ -45,6 +45,11 @@ impl SrttCache {
         }
     }
 
+    /// Whether we have observed RTT data for this IP.
+    pub fn is_known(&self, ip: IpAddr) -> bool {
+        self.entries.contains_key(&ip)
+    }
+
     /// Apply time-based decay: each DECAY_AFTER_SECS period halves distance to INITIAL.
     fn decayed_srtt(entry: &SrttEntry) -> u64 {
         Self::decay_for_age(entry.srtt_ms, entry.updated_at.elapsed().as_secs())

src/stats.rs

@@ -90,6 +90,7 @@ fn linux_rss() -> usize {
 pub struct ServerStats {
     queries_total: u64,
     queries_forwarded: u64,
+    queries_upstream: u64,
     queries_recursive: u64,
     queries_coalesced: u64,
     queries_cached: u64,
@@ -97,14 +98,69 @@ pub struct ServerStats {
     queries_local: u64,
     queries_overridden: u64,
     upstream_errors: u64,
+    transport_udp: u64,
+    transport_tcp: u64,
+    transport_dot: u64,
+    transport_doh: u64,
+    upstream_transport_udp: u64,
+    upstream_transport_doh: u64,
+    upstream_transport_dot: u64,
+    upstream_transport_odoh: u64,
     started_at: Instant,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum Transport {
+    Udp,
+    Tcp,
+    Dot,
+    Doh,
+}
+
+impl Transport {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            Transport::Udp => "UDP",
+            Transport::Tcp => "TCP",
+            Transport::Dot => "DOT",
+            Transport::Doh => "DOH",
+        }
+    }
+}
+
+/// Wire protocol used for a forwarded upstream call. Orthogonal to
+/// `QueryPath`: the path answers "where the answer came from"; this answers
+/// "over what wire we spoke to the forwarder." Callers pass
+/// `Option<UpstreamTransport>` — `None` for resolutions that never touched
+/// a forwarder (cache/local/blocked) or for recursive mode, which has its
+/// own counter via `QueryPath::Recursive`.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum UpstreamTransport {
+    Udp,
+    Doh,
+    Dot,
+    Odoh,
+}
+
+impl UpstreamTransport {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            UpstreamTransport::Udp => "UDP",
+            UpstreamTransport::Doh => "DOH",
+            UpstreamTransport::Dot => "DOT",
+            UpstreamTransport::Odoh => "ODOH",
+        }
+    }
+}
+
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum QueryPath {
     Local,
     Cached,
+    /// Matched a `[[forwarding]]` suffix rule.
     Forwarded,
+    /// Resolved via the default `[upstream]` pool (no suffix match).
+    Upstream,
     Recursive,
     Coalesced,
     Blocked,
@@ -118,6 +174,7 @@ impl QueryPath {
             QueryPath::Local => "LOCAL",
             QueryPath::Cached => "CACHED",
             QueryPath::Forwarded => "FORWARD",
+            QueryPath::Upstream => "UPSTREAM",
             QueryPath::Recursive => "RECURSIVE",
             QueryPath::Coalesced => "COALESCED",
             QueryPath::Blocked => "BLOCKED",
@@ -133,6 +190,8 @@ impl QueryPath {
             Some(QueryPath::Cached)
         } else if s.eq_ignore_ascii_case("FORWARD") {
             Some(QueryPath::Forwarded)
+        } else if s.eq_ignore_ascii_case("UPSTREAM") {
+            Some(QueryPath::Upstream)
         } else if s.eq_ignore_ascii_case("RECURSIVE") {
             Some(QueryPath::Recursive)
         } else if s.eq_ignore_ascii_case("COALESCED") {
@@ -160,6 +219,7 @@ impl ServerStats {
         ServerStats {
             queries_total: 0,
             queries_forwarded: 0,
+            queries_upstream: 0,
             queries_recursive: 0,
             queries_coalesced: 0,
             queries_cached: 0,
@@ -167,22 +227,50 @@ impl ServerStats {
             queries_local: 0,
             queries_overridden: 0,
             upstream_errors: 0,
+            transport_udp: 0,
+            transport_tcp: 0,
+            transport_dot: 0,
+            transport_doh: 0,
+            upstream_transport_udp: 0,
+            upstream_transport_doh: 0,
+            upstream_transport_dot: 0,
+            upstream_transport_odoh: 0,
             started_at: Instant::now(),
         }
     }
 
-    pub fn record(&mut self, path: QueryPath) -> u64 {
+    pub fn record(
+        &mut self,
+        path: QueryPath,
+        transport: Transport,
+        upstream_transport: Option<UpstreamTransport>,
+    ) -> u64 {
         self.queries_total += 1;
         match path {
             QueryPath::Local => self.queries_local += 1,
             QueryPath::Cached => self.queries_cached += 1,
             QueryPath::Forwarded => self.queries_forwarded += 1,
+            QueryPath::Upstream => self.queries_upstream += 1,
             QueryPath::Recursive => self.queries_recursive += 1,
             QueryPath::Coalesced => self.queries_coalesced += 1,
             QueryPath::Blocked => self.queries_blocked += 1,
             QueryPath::Overridden => self.queries_overridden += 1,
             QueryPath::UpstreamError => self.upstream_errors += 1,
         }
+        match transport {
+            Transport::Udp => self.transport_udp += 1,
+            Transport::Tcp => self.transport_tcp += 1,
+            Transport::Dot => self.transport_dot += 1,
+            Transport::Doh => self.transport_doh += 1,
+        }
+        if let Some(ut) = upstream_transport {
+            match ut {
+                UpstreamTransport::Udp => self.upstream_transport_udp += 1,
+                UpstreamTransport::Doh => self.upstream_transport_doh += 1,
+                UpstreamTransport::Dot => self.upstream_transport_dot += 1,
+                UpstreamTransport::Odoh => self.upstream_transport_odoh += 1,
+            }
+        }
         self.queries_total
     }
 
@@ -199,6 +287,7 @@ impl ServerStats {
             uptime_secs: self.uptime_secs(),
             total: self.queries_total,
             forwarded: self.queries_forwarded,
+            upstream: self.queries_upstream,
             recursive: self.queries_recursive,
             coalesced: self.queries_coalesced,
             cached: self.queries_cached,
@@ -206,6 +295,14 @@ impl ServerStats {
             overridden: self.queries_overridden,
             blocked: self.queries_blocked,
             errors: self.upstream_errors,
+            transport_udp: self.transport_udp,
+            transport_tcp: self.transport_tcp,
+            transport_dot: self.transport_dot,
+            transport_doh: self.transport_doh,
+            upstream_transport_udp: self.upstream_transport_udp,
+            upstream_transport_doh: self.upstream_transport_doh,
+            upstream_transport_dot: self.upstream_transport_dot,
+            upstream_transport_odoh: self.upstream_transport_odoh,
         }
     }
 
@@ -216,10 +313,11 @@ impl ServerStats {
         let secs = uptime.as_secs() % 60;
 
         log::info!(
-            "STATS | uptime {}h{}m{}s | total {} | fwd {} | recursive {} | coalesced {} | cached {} | local {} | override {} | blocked {} | errors {}",
+            "STATS | uptime {}h{}m{}s | total {} | fwd {} | upstream {} | recursive {} | coalesced {} | cached {} | local {} | override {} | blocked {} | errors {} | up-udp {} | up-doh {} | up-dot {} | up-odoh {}",
             hours, mins, secs,
             self.queries_total,
             self.queries_forwarded,
+            self.queries_upstream,
             self.queries_recursive,
             self.queries_coalesced,
             self.queries_cached,
@@ -227,6 +325,10 @@ impl ServerStats {
             self.queries_overridden,
             self.queries_blocked,
             self.upstream_errors,
+            self.upstream_transport_udp,
+            self.upstream_transport_doh,
+            self.upstream_transport_dot,
+            self.upstream_transport_odoh,
         );
     }
 }
@@ -235,6 +337,7 @@ pub struct StatsSnapshot {
     pub uptime_secs: u64,
     pub total: u64,
     pub forwarded: u64,
+    pub upstream: u64,
     pub recursive: u64,
     pub coalesced: u64,
     pub cached: u64,
@@ -242,4 +345,12 @@ pub struct StatsSnapshot {
     pub overridden: u64,
     pub blocked: u64,
     pub errors: u64,
+    pub transport_udp: u64,
+    pub transport_tcp: u64,
+    pub transport_dot: u64,
+    pub transport_doh: u64,
+    pub upstream_transport_udp: u64,
+    pub upstream_transport_doh: u64,
+    pub upstream_transport_dot: u64,
+    pub upstream_transport_odoh: u64,
 }

src/svcb.rs

@@ -0,0 +1,179 @@
+//! Minimal SVCB/HTTPS (RFC 9460) RDATA parser — just enough to strip
+//! the `ipv6hint` SvcParam. Used by the `filter_aaaa` feature so
+//! HTTPS-record-aware clients (Chrome ≥103, Firefox, Safari) don't
+//! receive v6 address hints on IPv4-only networks.
+
+/// SvcParamKey = 6 (RFC 9460 §14.3.2).
+const IPV6_HINT_KEY: u16 = 6;
+
+/// Strip the `ipv6hint` SvcParam from an HTTPS/SVCB RDATA blob.
+///
+/// Returns `Some(new_rdata)` if `ipv6hint` was present and removed.
+/// Returns `None` if the record had no `ipv6hint`, or if the RDATA
+/// couldn't be parsed — in both cases the caller should keep the
+/// original bytes untouched.
+///
+/// SVCB RDATA (RFC 9460 §2.2):
+///   SvcPriority (u16)
+///   TargetName  (uncompressed DNS name — labels terminated by 0 octet)
+///   SvcParams   (series of {u16 key, u16 len, opaque[len] value}, sorted by key)
+pub fn strip_ipv6hint(rdata: &[u8]) -> Option<Vec<u8>> {
+    if rdata.len() < 2 {
+        return None;
+    }
+    let mut pos = 2;
+
+    // TargetName — uncompressed per RFC 9460 §2.2
+    loop {
+        let len = *rdata.get(pos)? as usize;
+        pos += 1;
+        if len == 0 {
+            break;
+        }
+        if len & 0xC0 != 0 {
+            // Pointer: forbidden in SVCB but defend against a broken upstream.
+            return None;
+        }
+        pos = pos.checked_add(len)?;
+        if pos > rdata.len() {
+            return None;
+        }
+    }
+
+    // Scan params once to decide whether we need to rebuild.
+    let params_start = pos;
+    let mut scan = pos;
+    let mut has_ipv6hint = false;
+    while scan < rdata.len() {
+        if scan + 4 > rdata.len() {
+            return None;
+        }
+        let key = u16::from_be_bytes([rdata[scan], rdata[scan + 1]]);
+        let vlen = u16::from_be_bytes([rdata[scan + 2], rdata[scan + 3]]) as usize;
+        let end = scan.checked_add(4)?.checked_add(vlen)?;
+        if end > rdata.len() {
+            return None;
+        }
+        if key == IPV6_HINT_KEY {
+            has_ipv6hint = true;
+        }
+        scan = end;
+    }
+    if scan != rdata.len() || !has_ipv6hint {
+        return None;
+    }
+
+    // Rebuild without ipv6hint, preserving param order (RFC 9460 requires
+    // ascending key order, which we preserve by filtering in place).
+    let mut out = Vec::with_capacity(rdata.len());
+    out.extend_from_slice(&rdata[..params_start]);
+    let mut pos = params_start;
+    while pos < rdata.len() {
+        let key = u16::from_be_bytes([rdata[pos], rdata[pos + 1]]);
+        let vlen = u16::from_be_bytes([rdata[pos + 2], rdata[pos + 3]]) as usize;
+        let end = pos + 4 + vlen;
+        if key != IPV6_HINT_KEY {
+            out.extend_from_slice(&rdata[pos..end]);
+        }
+        pos = end;
+    }
+    Some(out)
+}
+
+/// Build an SVCB RDATA blob from a priority, target labels, and
+/// (key, value) param pairs. Shared by `svcb` unit tests and `ctx`
+/// pipeline tests that need to seed the cache with a synthetic HTTPS RR.
+#[cfg(test)]
+pub(crate) fn build_rdata(priority: u16, target: &[&str], params: &[(u16, Vec<u8>)]) -> Vec<u8> {
+    let mut out = Vec::new();
+    out.extend_from_slice(&priority.to_be_bytes());
+    for label in target {
+        out.push(label.len() as u8);
+        out.extend_from_slice(label.as_bytes());
+    }
+    out.push(0);
+    for (key, value) in params {
+        out.extend_from_slice(&key.to_be_bytes());
+        out.extend_from_slice(&(value.len() as u16).to_be_bytes());
+        out.extend_from_slice(value);
+    }
+    out
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn alpn_h3() -> (u16, Vec<u8>) {
+        // alpn = ["h3"]: one length-prefixed ALPN id
+        (1, vec![0x02, b'h', b'3'])
+    }
+
+    fn ipv4hint_single() -> (u16, Vec<u8>) {
+        (4, vec![93, 184, 216, 34])
+    }
+
+    fn ipv6hint_single() -> (u16, Vec<u8>) {
+        // 2606:4700::1
+        (
+            6,
+            vec![
+                0x26, 0x06, 0x47, 0x00, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01,
+            ],
+        )
+    }
+
+    #[test]
+    fn strips_ipv6hint_and_keeps_other_params() {
+        let rdata = build_rdata(1, &[], &[alpn_h3(), ipv4hint_single(), ipv6hint_single()]);
+        let stripped = strip_ipv6hint(&rdata).expect("ipv6hint present → stripped");
+        let expected = build_rdata(1, &[], &[alpn_h3(), ipv4hint_single()]);
+        assert_eq!(stripped, expected);
+    }
+
+    #[test]
+    fn no_ipv6hint_returns_none() {
+        let rdata = build_rdata(1, &[], &[alpn_h3(), ipv4hint_single()]);
+        assert!(strip_ipv6hint(&rdata).is_none());
+    }
+
+    #[test]
+    fn alias_mode_empty_params_returns_none() {
+        let rdata = build_rdata(0, &["example", "com"], &[]);
+        assert!(strip_ipv6hint(&rdata).is_none());
+    }
+
+    #[test]
+    fn only_ipv6hint_yields_empty_param_section() {
+        let rdata = build_rdata(1, &[], &[ipv6hint_single()]);
+        let stripped = strip_ipv6hint(&rdata).expect("ipv6hint present → stripped");
+        let expected = build_rdata(1, &[], &[]);
+        assert_eq!(stripped, expected);
+    }
+
+    #[test]
+    fn preserves_target_name() {
+        let rdata = build_rdata(1, &["svc", "example", "net"], &[ipv6hint_single()]);
+        let stripped = strip_ipv6hint(&rdata).unwrap();
+        assert!(stripped.starts_with(&[0x00, 0x01])); // priority
+        assert_eq!(&stripped[2..6], b"\x03svc");
+    }
+
+    #[test]
+    fn truncated_rdata_returns_none() {
+        // Priority only, no target terminator.
+        assert!(strip_ipv6hint(&[0, 1, 3, b'c', b'o', b'm']).is_none());
+    }
+
+    #[test]
+    fn empty_input_returns_none() {
+        assert!(strip_ipv6hint(&[]).is_none());
+    }
+
+    #[test]
+    fn param_length_overflow_returns_none() {
+        // key=6, length=0xFFFF but value is short — malformed.
+        let rdata = vec![0, 1, 0, 0, 6, 0xFF, 0xFF, 0, 1, 2];
+        assert!(strip_ipv6hint(&rdata).is_none());
+    }
+}

src/system_dns.rs

@@ -2,6 +2,10 @@ use std::net::SocketAddr;
 
 use log::info;
 
+#[cfg(any(target_os = "macos", target_os = "linux"))]
+use crate::forward::Upstream;
+use crate::forward::UpstreamPool;
+
 fn print_recursive_hint() {
     let is_recursive = crate::config::load_config("numa.toml")
         .map(|c| c.config.upstream.mode == crate::config::UpstreamMode::Recursive)
@@ -18,11 +22,22 @@ fn is_loopback_or_stub(addr: &str) -> bool {
 }
 
 /// A conditional forwarding rule: domains matching `suffix` are forwarded to `upstream`.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct ForwardingRule {
     pub suffix: String,
     dot_suffix: String, // pre-computed ".suffix" for zero-alloc matching
-    pub upstream: SocketAddr,
+    pub upstream: UpstreamPool,
+}
+
+impl ForwardingRule {
+    pub fn new(suffix: String, upstream: UpstreamPool) -> Self {
+        let dot_suffix = format!(".{}", suffix);
+        Self {
+            suffix,
+            dot_suffix,
+            upstream,
+        }
+    }
 }
 
 /// Result of system DNS discovery — default upstream + conditional forwarding rules.
@@ -91,7 +106,7 @@ pub fn try_port53_advisory(bind_addr: &str, err: &std::io::Error) -> Option<Stri
          sudo numa install       (on Windows, run as Administrator)
 
     2. Run on a non-privileged port for testing.
-       Create ~/.config/numa/numa.toml with:
+       Create {} with:
 
          [server]
          bind_addr = \"127.0.0.1:5354\"
@@ -100,7 +115,8 @@ pub fn try_port53_advisory(bind_addr: &str, err: &std::io::Error) -> Option<Stri
        Then run:  numa
        Test with: dig @127.0.0.1 -p 5354 example.com
 
-"
+",
+        crate::suggested_config_path().display()
     ))
 }
 
@@ -197,12 +213,13 @@ fn discover_macos() -> SystemDnsInfo {
     }
 
     // Sort longest suffix first for most-specific matching
-    rules.sort_by(|a, b| b.suffix.len().cmp(&a.suffix.len()));
+    rules.sort_by_key(|r| std::cmp::Reverse(r.suffix.len()));
 
     for rule in &rules {
         info!(
             "auto-discovered forwarding: *.{} -> {}",
-            rule.suffix, rule.upstream
+            rule.suffix,
+            rule.upstream.label()
         );
     }
     if rules.is_empty() {
@@ -220,12 +237,9 @@ fn discover_macos() -> SystemDnsInfo {
 
 #[cfg(any(target_os = "macos", target_os = "linux"))]
 fn make_rule(domain: &str, nameserver: &str) -> Option<ForwardingRule> {
-    let addr: SocketAddr = format!("{}:53", nameserver).parse().ok()?;
-    Some(ForwardingRule {
-        dot_suffix: format!(".{}", domain),
-        suffix: domain.to_string(),
-        upstream: addr,
-    })
+    let addr = crate::forward::parse_upstream_addr(nameserver, 53).ok()?;
+    let pool = UpstreamPool::new(vec![Upstream::Udp(addr)], vec![]);
+    Some(ForwardingRule::new(domain.to_string(), pool))
 }
 
 #[cfg(target_os = "linux")]
@@ -562,7 +576,7 @@ fn windows_backup_path() -> std::path::PathBuf {
 
 #[cfg(windows)]
 fn disable_dnscache() -> Result<bool, String> {
-    // Check if Dnscache is running (it holds port 53 at kernel level)
+    // Check if Dnscache is running (it can hold port 53)
     let output = std::process::Command::new("sc")
         .args(["query", "Dnscache"])
         .output()
@@ -593,8 +607,16 @@ fn disable_dnscache() -> Result<bool, String> {
         return Err("failed to disable Dnscache via registry (run as Administrator?)".into());
     }
 
-    eprintln!("  Dnscache disabled. A reboot is required to free port 53.");
-    Ok(true)
+    // Dnscache is disabled for next boot. Check whether port 53 is
+    // actually blocked right now — on many Windows configurations
+    // Dnscache doesn't bind port 53 even while running.
+    let port_blocked = std::net::UdpSocket::bind("127.0.0.1:53").is_err();
+    if port_blocked {
+        eprintln!("  Dnscache disabled. A reboot is required to free port 53.");
+    } else {
+        eprintln!("  Dnscache disabled. Port 53 is free.");
+    }
+    Ok(port_blocked)
 }
 
 #[cfg(windows)]
@@ -661,6 +683,83 @@ fn install_windows() -> Result<(), String> {
         std::fs::write(&path, json).map_err(|e| format!("failed to write backup: {}", e))?;
     }
 
+    // On re-install, stop the running service first so the binary can be
+    // overwritten and port 53 is released for the Dnscache probe.
+    if is_service_registered() {
+        eprintln!("  Stopping existing service...");
+        stop_service_scm();
+    }
+
+    let needs_reboot = disable_dnscache()?;
+
+    // Copy the binary to a stable path under ProgramData and register it
+    // as a real Windows service (SCM-managed, boot-time, auto-restart).
+    let service_exe = install_service_binary()?;
+    register_service_scm(&service_exe)?;
+
+    if needs_reboot {
+        // Dnscache still holds port 53 until reboot. Do NOT redirect DNS
+        // yet — nothing is listening on 127.0.0.1:53, so redirecting now
+        // would kill DNS. The service will call redirect_dns_to_localhost()
+        // on its first startup after reboot.
+    } else {
+        redirect_dns_with_interfaces(&interfaces)?;
+
+        match start_service_scm() {
+            Ok(_) => eprintln!("  Service started."),
+            Err(e) => eprintln!(
+                "  warning: service registered but could not start now: {}",
+                e
+            ),
+        }
+    }
+
+    eprintln!();
+    if !has_useful_existing {
+        eprintln!("  Original DNS saved to {}", path.display());
+    }
+    eprintln!("  Run 'numa uninstall' to restore.\n");
+    if needs_reboot {
+        eprintln!("  *** Reboot required. Numa will start automatically. ***\n");
+    } else {
+        eprintln!("  Numa is running.\n");
+    }
+    print_recursive_hint();
+    Ok(())
+}
+
+/// Stable install location for the service binary. SCM keeps a handle to
+/// this path; the user's Downloads folder (where `current_exe()` points at
+/// install time) is not durable.
+#[cfg(windows)]
+fn windows_service_exe_path() -> std::path::PathBuf {
+    crate::data_dir().join("bin").join("numa.exe")
+}
+
+/// Run `sc.exe` with the given args and return its merged stdout/stderr on
+/// failure. `sc` emits errors on stdout (not stderr) on Windows, so the
+/// caller reads stdout to format a useful error.
+#[cfg(windows)]
+fn run_sc(args: &[&str]) -> Result<std::process::Output, String> {
+    let out = std::process::Command::new("sc")
+        .args(args)
+        .output()
+        .map_err(|e| format!("failed to run sc {}: {}", args.first().unwrap_or(&""), e))?;
+    Ok(out)
+}
+
+/// Point all active network interfaces at 127.0.0.1 so Numa handles DNS.
+/// Called from the service on first boot after a reboot that freed Dnscache.
+#[cfg(windows)]
+pub fn redirect_dns_to_localhost() -> Result<(), String> {
+    let interfaces = get_windows_interfaces()?;
+    redirect_dns_with_interfaces(&interfaces)
+}
+
+#[cfg(windows)]
+fn redirect_dns_with_interfaces(
+    interfaces: &std::collections::HashMap<String, WindowsInterfaceDns>,
+) -> Result<(), String> {
     for name in interfaces.keys() {
         let status = std::process::Command::new("netsh")
             .args([
@@ -685,63 +784,184 @@ fn install_windows() -> Result<(), String> {
             );
         }
     }
-
-    let needs_reboot = disable_dnscache()?;
-    register_autostart();
-
-    eprintln!();
-    if !has_useful_existing {
-        eprintln!("  Original DNS saved to {}", path.display());
-    }
-    eprintln!("  Run 'numa uninstall' to restore.\n");
-    if needs_reboot {
-        eprintln!("  *** Reboot required. Numa will start automatically. ***\n");
-    } else {
-        eprintln!("  Numa will start automatically on next boot.\n");
-    }
-    print_recursive_hint();
     Ok(())
 }
 
-/// Register numa to auto-start on boot via registry Run key.
+/// Copy the currently-running binary to the service install location. SCM
+/// keeps a handle to this path, so it must be stable across user sessions.
 #[cfg(windows)]
-fn register_autostart() {
-    let exe = std::env::current_exe()
-        .map(|p| p.to_string_lossy().to_string())
-        .unwrap_or_else(|_| "numa".into());
-    let _ = std::process::Command::new("reg")
-        .args([
-            "add",
-            "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run",
-            "/v",
-            "Numa",
-            "/t",
-            "REG_SZ",
-            "/d",
-            &exe,
-            "/f",
-        ])
-        .status();
-    eprintln!("  Registered auto-start on boot.");
+fn install_service_binary() -> Result<std::path::PathBuf, String> {
+    let src = std::env::current_exe().map_err(|e| format!("current_exe(): {}", e))?;
+    let dst = windows_service_exe_path();
+    if let Some(parent) = dst.parent() {
+        std::fs::create_dir_all(parent)
+            .map_err(|e| format!("failed to create {}: {}", parent.display(), e))?;
+    }
+    // Copy only if source and destination differ; running the binary from
+    // its install location is a supported (re-install) case.
+    if src != dst {
+        std::fs::copy(&src, &dst).map_err(|e| {
+            format!(
+                "failed to copy {} -> {}: {}",
+                src.display(),
+                dst.display(),
+                e
+            )
+        })?;
+    }
+    Ok(dst)
 }
 
-/// Remove numa auto-start registry key.
+/// Remove the service binary on uninstall. Ignore failures — the service
+/// is already deleted; a leftover file in ProgramData is not a hard error.
 #[cfg(windows)]
-fn remove_autostart() {
-    let _ = std::process::Command::new("reg")
-        .args([
-            "delete",
-            "HKLM\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Run",
-            "/v",
-            "Numa",
-            "/f",
-        ])
-        .status();
+fn remove_service_binary() {
+    let _ = std::fs::remove_file(windows_service_exe_path());
+}
+
+/// Register numa with the Service Control Manager, boot-time auto-start,
+/// LocalSystem context, with a failure policy of restart-after-5s.
+#[cfg(windows)]
+fn register_service_scm(exe: &std::path::Path) -> Result<(), String> {
+    let bin_path = format!("\"{}\" --service", exe.display());
+    let name = crate::windows_service::SERVICE_NAME;
+
+    // sc.exe uses a leading space as its `name= value` delimiter; the space
+    // after `=` is mandatory.
+    let create = run_sc(&[
+        "create",
+        name,
+        "binPath=",
+        &bin_path,
+        "DisplayName=",
+        "Numa DNS",
+        "start=",
+        "auto",
+        "obj=",
+        "LocalSystem",
+    ])?;
+    if !create.status.success() {
+        let out = String::from_utf8_lossy(&create.stdout);
+        // "service already exists" is 1073 — treat as idempotent success.
+        if !out.contains("1073") {
+            return Err(format!("sc create failed: {}", out.trim()));
+        }
+    }
+
+    let _ = run_sc(&[
+        "description",
+        name,
+        "Self-sovereign DNS resolver (ad blocking, DoH/DoT, local zones).",
+    ]);
+
+    // Restart on crash: 5s, 5s, 10s; reset failure counter after 60s.
+    let _ = run_sc(&[
+        "failure",
+        name,
+        "reset=",
+        "60",
+        "actions=",
+        "restart/5000/restart/5000/restart/10000",
+    ]);
+
+    eprintln!("  Registered service '{}' (boot-time).", name);
+    Ok(())
+}
+
+/// Start the service. Safe to call on a freshly-registered service — SCM
+/// will fail with 1056 ("already running") or 1058 ("disabled") and we
+/// return the underlying error string rather than masking it.
+#[cfg(windows)]
+fn start_service_scm() -> Result<(), String> {
+    let out = run_sc(&["start", crate::windows_service::SERVICE_NAME])?;
+    if !out.status.success() {
+        let text = String::from_utf8_lossy(&out.stdout);
+        if text.contains("1056") {
+            return Ok(()); // already running
+        }
+        return Err(format!("sc start failed: {}", text.trim()));
+    }
+    Ok(())
+}
+
+/// Stop the service and wait for it to fully exit. Idempotent —
+/// already-stopped or missing service is not an error.
+#[cfg(windows)]
+fn stop_service_scm() {
+    let name = crate::windows_service::SERVICE_NAME;
+    let _ = run_sc(&["stop", name]);
+    // Wait up to 10s for the service to reach STOPPED state so the
+    // binary file handle is released before we try to overwrite it.
+    for _ in 0..20 {
+        if let Ok(out) = run_sc(&["query", name]) {
+            let text = String::from_utf8_lossy(&out.stdout);
+            if text.contains("STOPPED") || text.contains("1060") {
+                return;
+            }
+        }
+        std::thread::sleep(std::time::Duration::from_millis(500));
+    }
+    eprintln!("  warning: service did not stop within 10s");
+}
+
+/// Remove the service from SCM. Idempotent — see `stop_service_scm`.
+#[cfg(windows)]
+fn delete_service_scm() {
+    if let Err(e) = run_sc(&["delete", crate::windows_service::SERVICE_NAME]) {
+        log::warn!("sc delete failed: {}", e);
+    }
+}
+
+/// Check whether the service is registered with SCM (regardless of state).
+#[cfg(windows)]
+fn is_service_registered() -> bool {
+    run_sc(&["query", crate::windows_service::SERVICE_NAME])
+        .map(|o| parse_sc_registered(o.status.success(), &String::from_utf8_lossy(&o.stdout)))
+        .unwrap_or(false)
+}
+
+/// Parse `sc query` output to determine if a service is registered.
+/// Extracted for testability — the actual `sc` call is in `is_service_registered`.
+#[cfg(any(windows, test))]
+fn parse_sc_registered(exit_success: bool, stdout: &str) -> bool {
+    if exit_success {
+        return true;
+    }
+    // Error 1060 = "The specified service does not exist as an installed service."
+    !stdout.contains("1060")
+}
+
+/// Print service state from SCM.
+#[cfg(windows)]
+fn service_status_windows() -> Result<(), String> {
+    let out = run_sc(&["query", crate::windows_service::SERVICE_NAME])?;
+    let text = String::from_utf8_lossy(&out.stdout);
+    let display = parse_sc_state(&text);
+    eprintln!("  {}\n", display);
+    Ok(())
+}
+
+/// Parse the STATE line from `sc query` output. Returns a human-readable
+/// string like "STATE : 4 RUNNING" or "Service is not installed."
+#[cfg(any(windows, test))]
+fn parse_sc_state(sc_output: &str) -> String {
+    if sc_output.contains("1060") {
+        return "Service is not installed.".to_string();
+    }
+    sc_output
+        .lines()
+        .find(|l| l.contains("STATE"))
+        .map(|l| l.trim().to_string())
+        .unwrap_or_else(|| "unknown".to_string())
 }
 
 #[cfg(windows)]
 fn uninstall_windows() -> Result<(), String> {
-    remove_autostart();
+    // Stop + remove the service before touching DNS, so port 53 is released
+    // cleanly and the failure-restart policy doesn't resurrect it.
+    stop_service_scm();
+    delete_service_scm();
+    remove_service_binary();
     let path = windows_backup_path();
     let json = std::fs::read_to_string(&path)
         .map_err(|e| format!("no backup found at {}: {}", path.display(), e))?;
@@ -814,10 +1034,13 @@ fn uninstall_windows() -> Result<(), String> {
 /// Find the upstream for a domain by checking forwarding rules.
 /// Returns None if no rule matches (use default upstream).
 /// Zero-allocation on the hot path — dot_suffix is pre-computed.
-pub fn match_forwarding_rule(domain: &str, rules: &[ForwardingRule]) -> Option<SocketAddr> {
+pub fn match_forwarding_rule<'a>(
+    domain: &str,
+    rules: &'a [ForwardingRule],
+) -> Option<&'a UpstreamPool> {
     for rule in rules {
         if domain == rule.suffix || domain.ends_with(&rule.dot_suffix) {
-            return Some(rule.upstream);
+            return Some(&rule.upstream);
         }
     }
     None
@@ -1035,6 +1258,62 @@ pub fn install_service() -> Result<(), String> {
     result
 }
 
+/// Start the service. If already installed, just starts it via the platform
+/// service manager. If not installed, falls through to a full install.
+pub fn start_service() -> Result<(), String> {
+    #[cfg(target_os = "macos")]
+    {
+        install_service()
+    }
+    #[cfg(target_os = "linux")]
+    {
+        install_service()
+    }
+    #[cfg(windows)]
+    {
+        if is_service_registered() {
+            start_service_scm()?;
+            eprintln!("  Service started.\n");
+            Ok(())
+        } else {
+            install_service()
+        }
+    }
+    #[cfg(not(any(target_os = "macos", target_os = "linux", windows)))]
+    {
+        Err("service start not supported on this OS".to_string())
+    }
+}
+
+/// Stop the service without uninstalling it.
+pub fn stop_service() -> Result<(), String> {
+    #[cfg(target_os = "macos")]
+    {
+        uninstall_service()
+    }
+    #[cfg(target_os = "linux")]
+    {
+        uninstall_service()
+    }
+    #[cfg(windows)]
+    {
+        let out = run_sc(&["stop", crate::windows_service::SERVICE_NAME])?;
+        if !out.status.success() {
+            let text = String::from_utf8_lossy(&out.stdout);
+            // 1062 = not started, 1060 = does not exist
+            if !text.contains("1062") && !text.contains("1060") {
+                return Err(format!("sc stop failed: {}", text.trim()));
+            }
+        }
+        eprintln!("  Service stopped.\n");
+        Ok(())
+    }
+    #[cfg(not(any(target_os = "macos", target_os = "linux", windows)))]
+    {
+        Err("service stop not supported on this OS".to_string())
+    }
+}
+
 /// Uninstall the Numa system service.
 pub fn uninstall_service() -> Result<(), String> {
     let _ = untrust_ca();
@@ -1104,7 +1383,14 @@ pub fn restart_service() -> Result<(), String> {
         eprintln!("  Service restarted → {}\n", version);
         Ok(())
     }
-    #[cfg(not(any(target_os = "macos", target_os = "linux")))]
+    #[cfg(windows)]
+    {
+        stop_service_scm();
+        start_service_scm()?;
+        eprintln!("  Service restarted.\n");
+        Ok(())
+    }
+    #[cfg(not(any(target_os = "macos", target_os = "linux", windows)))]
     {
         Err("service restart not supported on this OS".to_string())
     }
@@ -1120,13 +1406,17 @@ pub fn service_status() -> Result<(), String> {
     {
         service_status_linux()
     }
-    #[cfg(not(any(target_os = "macos", target_os = "linux")))]
+    #[cfg(windows)]
+    {
+        service_status_windows()
+    }
+    #[cfg(not(any(target_os = "macos", target_os = "linux", windows)))]
     {
         Err("service status not supported on this OS".to_string())
     }
 }
 
-#[cfg(any(target_os = "macos", target_os = "linux"))]
+#[cfg(target_os = "macos")]
 fn replace_exe_path(service: &str) -> Result<String, String> {
     let exe_path =
         std::env::current_exe().map_err(|e| format!("failed to get current exe: {}", e))?;
@@ -1374,10 +1664,78 @@ fn uninstall_linux() -> Result<(), String> {
     Ok(())
 }
 
+/// Fallback install location when current_exe() sits on a path the
+/// dynamic user cannot traverse (e.g. `/home/<user>/` mode 0700).
+#[cfg(target_os = "linux")]
+fn linux_service_exe_path() -> std::path::PathBuf {
+    std::path::PathBuf::from("/usr/local/bin/numa")
+}
+
+/// True iff every ancestor of `p` (excluding `/`) grants world-execute —
+/// i.e. the `DynamicUser=yes` service account can traverse the path and
+/// exec the binary without being in any group. Linuxbrew's
+/// `/home/linuxbrew` is 0755 (traversable, keep brew's path, upgrades
+/// via `brew` propagate). A build tree under `/home/<user>/` (0700) or
+/// `~/.cargo/bin/` is not (copy to /usr/local/bin so systemd can reach it).
+#[cfg(target_os = "linux")]
+fn path_world_traversable_linux(p: &std::path::Path) -> bool {
+    use std::os::unix::fs::PermissionsExt;
+    let mut current = p;
+    while let Some(parent) = current.parent() {
+        if parent.as_os_str().is_empty() || parent == std::path::Path::new("/") {
+            break;
+        }
+        match std::fs::metadata(parent) {
+            Ok(m) if m.permissions().mode() & 0o001 != 0 => {}
+            _ => return false,
+        }
+        current = parent;
+    }
+    true
+}
+
+#[cfg(target_os = "linux")]
+fn install_service_binary_linux() -> Result<std::path::PathBuf, String> {
+    let src = std::env::current_exe().map_err(|e| format!("current_exe(): {}", e))?;
+    if path_world_traversable_linux(&src) {
+        return Ok(src);
+    }
+    let dst = linux_service_exe_path();
+    if src == dst {
+        return Ok(dst);
+    }
+    if let Some(parent) = dst.parent() {
+        std::fs::create_dir_all(parent)
+            .map_err(|e| format!("failed to create {}: {}", parent.display(), e))?;
+    }
+    // Atomic replace via temp + rename. Plain copy fails with ETXTBSY when
+    // re-installing while the service is running the previous binary —
+    // rename swaps the path while the running process keeps the old inode.
+    let tmp = dst.with_extension("new");
+    std::fs::copy(&src, &tmp).map_err(|e| {
+        format!(
+            "failed to copy {} -> {}: {}",
+            src.display(),
+            tmp.display(),
+            e
+        )
+    })?;
+    std::fs::rename(&tmp, &dst).map_err(|e| {
+        let _ = std::fs::remove_file(&tmp);
+        format!(
+            "failed to rename {} -> {}: {}",
+            tmp.display(),
+            dst.display(),
+            e
+        )
+    })?;
+    Ok(dst)
+}
+
 #[cfg(target_os = "linux")]
 fn install_service_linux() -> Result<(), String> {
-    let unit = include_str!("../numa.service");
-    let unit = replace_exe_path(unit)?;
+    let exe = install_service_binary_linux()?;
+    let unit = include_str!("../numa.service").replace("{{exe_path}}", &exe.to_string_lossy());
     std::fs::write(SYSTEMD_UNIT, unit)
         .map_err(|e| format!("failed to write {}: {}", SYSTEMD_UNIT, e))?;
 
@@ -1389,7 +1747,9 @@ fn install_service_linux() -> Result<(), String> {
         eprintln!("  warning: failed to configure system DNS: {}", e);
     }
 
-    run_systemctl(&["start", "numa"])?;
+    // restart, not start: on re-install the service is already running
+    // the previous binary; restart picks up the new one.
+    run_systemctl(&["restart", "numa"])?;
 
     eprintln!("  Service installed and started.");
     eprintln!("  Numa will auto-start on boot and restart if killed.");
@@ -1705,22 +2065,25 @@ Wireless LAN adapter Wi-Fi:
     }
 
     #[test]
-    #[cfg(any(target_os = "macos", target_os = "linux"))]
-    fn replace_exe_path_substitutes_template() {
+    fn install_templates_contain_exe_path_placeholder() {
+        // Both files are substituted at install time — plist via
+        // replace_exe_path on macOS, numa.service via inline .replace
+        // in install_service_linux. Catch placeholder removal early.
         let plist = include_str!("../com.numa.dns.plist");
         let unit = include_str!("../numa.service");
-
         assert!(plist.contains("{{exe_path}}"), "plist missing placeholder");
         assert!(
             unit.contains("{{exe_path}}"),
             "unit file missing placeholder"
         );
+    }
 
+    #[test]
+    #[cfg(target_os = "macos")]
+    fn replace_exe_path_substitutes_template() {
+        let plist = include_str!("../com.numa.dns.plist");
         let result = replace_exe_path(plist).expect("replace_exe_path failed for plist");
         assert!(!result.contains("{{exe_path}}"));
-
-        let result = replace_exe_path(unit).expect("replace_exe_path failed for unit");
-        assert!(!result.contains("{{exe_path}}"));
     }
 
     #[test]
@@ -1854,4 +2217,57 @@ Wireless LAN adapter Wi-Fi:
         let err = std::io::Error::from(std::io::ErrorKind::AddrInUse);
         assert!(try_port53_advisory("not-an-address", &err).is_none());
     }
+
+    #[test]
+    fn sc_query_running_service_is_registered() {
+        assert!(parse_sc_registered(true, ""));
+    }
+
+    #[test]
+    fn sc_query_stopped_service_is_registered() {
+        let output = "SERVICE_NAME: Numa\n        TYPE: 10  WIN32_OWN\n        STATE: 1  STOPPED\n";
+        assert!(parse_sc_registered(true, output));
+    }
+
+    #[test]
+    fn sc_query_missing_service_not_registered() {
+        let output = "[SC] EnumQueryServicesStatus:OpenService FAILED 1060:\n\nThe specified service does not exist as an installed service.\n";
+        assert!(!parse_sc_registered(false, output));
+    }
+
+    #[test]
+    fn sc_query_other_error_assumes_registered() {
+        // Permission denied or other errors — don't assume unregistered.
+        let output = "[SC] OpenService FAILED 5:\n\nAccess is denied.\n";
+        assert!(parse_sc_registered(false, output));
+    }
+
+    #[test]
+    fn parse_sc_state_running() {
+        let output = "SERVICE_NAME: Numa\n        TYPE               : 10  WIN32_OWN_PROCESS\n        STATE              : 4  RUNNING\n        WIN32_EXIT_CODE    : 0\n";
+        assert!(parse_sc_state(output).contains("RUNNING"));
+    }
+
+    #[test]
+    fn parse_sc_state_stopped() {
+        let output = "SERVICE_NAME: Numa\n        TYPE               : 10  WIN32_OWN_PROCESS\n        STATE              : 1  STOPPED\n";
+        assert!(parse_sc_state(output).contains("STOPPED"));
+    }
+
+    #[test]
+    fn parse_sc_state_not_installed() {
+        let output = "[SC] EnumQueryServicesStatus:OpenService FAILED 1060:\n\n";
+        assert_eq!(parse_sc_state(output), "Service is not installed.");
+    }
+
+    #[test]
+    fn parse_sc_state_empty_output() {
+        assert_eq!(parse_sc_state(""), "unknown");
+    }
+
+    #[cfg(windows)]
+    #[test]
+    fn windows_config_dir_equals_data_dir() {
+        assert_eq!(crate::config_dir(), crate::data_dir());
+    }
 }

src/testutil.rs

@@ -0,0 +1,96 @@
+use std::collections::{HashMap, HashSet};
+use std::net::{Ipv4Addr, SocketAddr};
+use std::path::PathBuf;
+use std::sync::{Mutex, RwLock};
+use std::time::Duration;
+
+use tokio::net::UdpSocket;
+
+use crate::blocklist::BlocklistStore;
+use crate::buffer::BytePacketBuffer;
+use crate::cache::DnsCache;
+use crate::config::UpstreamMode;
+use crate::ctx::ServerCtx;
+use crate::forward::{Upstream, UpstreamPool};
+use crate::health::HealthMeta;
+use crate::lan::PeerStore;
+use crate::override_store::OverrideStore;
+use crate::packet::DnsPacket;
+use crate::query_log::QueryLog;
+use crate::service_store::ServiceStore;
+use crate::srtt::SrttCache;
+use crate::stats::ServerStats;
+/// Minimal `ServerCtx` for tests. Override fields after construction
+/// (all fields are `pub`), then wrap in `Arc`.
+pub async fn test_ctx() -> ServerCtx {
+    let socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    ServerCtx {
+        socket,
+        zone_map: HashMap::new(),
+        cache: RwLock::new(DnsCache::new(100, 60, 86400)),
+        refreshing: Mutex::new(HashSet::new()),
+        stats: Mutex::new(ServerStats::new()),
+        overrides: RwLock::new(OverrideStore::new()),
+        blocklist: RwLock::new(BlocklistStore::new()),
+        query_log: Mutex::new(QueryLog::new(100)),
+        services: Mutex::new(ServiceStore::new()),
+        lan_peers: Mutex::new(PeerStore::new(90)),
+        forwarding_rules: Vec::new(),
+        upstream_pool: Mutex::new(UpstreamPool::new(
+            vec![Upstream::Udp("127.0.0.1:53".parse().unwrap())],
+            vec![],
+        )),
+        upstream_auto: false,
+        upstream_port: 53,
+        lan_ip: Mutex::new(Ipv4Addr::LOCALHOST),
+        timeout: Duration::from_millis(200),
+        hedge_delay: Duration::ZERO,
+        proxy_tld: "numa".to_string(),
+        proxy_tld_suffix: ".numa".to_string(),
+        lan_enabled: false,
+        config_path: "/tmp/test-numa.toml".to_string(),
+        config_found: false,
+        config_dir: PathBuf::from("/tmp"),
+        data_dir: PathBuf::from("/tmp"),
+        tls_config: None,
+        upstream_mode: UpstreamMode::Forward,
+        root_hints: Vec::new(),
+        srtt: RwLock::new(SrttCache::new(true)),
+        inflight: Mutex::new(HashMap::new()),
+        dnssec_enabled: false,
+        dnssec_strict: false,
+        health_meta: HealthMeta::test_fixture(),
+        ca_pem: None,
+        mobile_enabled: false,
+        mobile_port: 8765,
+        filter_aaaa: false,
+    }
+}
+
+/// Spawn a UDP socket that replies to the first DNS query with the given
+/// response packet (patching the query ID to match). Returns the socket address.
+pub async fn mock_upstream(response: DnsPacket) -> SocketAddr {
+    let sock = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+    let addr = sock.local_addr().unwrap();
+    tokio::spawn(async move {
+        let mut buf = [0u8; 512];
+        let (_, src) = sock.recv_from(&mut buf).await.unwrap();
+        let query_id = u16::from_be_bytes([buf[0], buf[1]]);
+        let mut resp = response;
+        resp.header.id = query_id;
+        let mut out = BytePacketBuffer::new();
+        resp.write(&mut out).unwrap();
+        sock.send_to(out.filled(), src).await.unwrap();
+    });
+    addr
+}
+
+/// UDP socket that accepts connections but never replies.
+/// Useful as an upstream that triggers timeouts.
+pub fn blackhole_upstream() -> SocketAddr {
+    let sock = std::net::UdpSocket::bind("127.0.0.1:0").unwrap();
+    let addr = sock.local_addr().unwrap();
+    // Leak so it stays bound for the duration of the test process.
+    Box::leak(Box::new(sock));
+    addr
+}

src/tls.rs

@@ -66,13 +66,14 @@ pub fn try_data_dir_advisory(err: &crate::Error, data_dir: &Path) -> Option<Stri
          sudo numa install       (on Windows, run as Administrator)
 
     2. Point data_dir at a path you can write.
-       Create ~/.config/numa/numa.toml with:
+       Create {} with:
 
          [server]
          data_dir = \"/path/you/can/write\"
 
 ",
-        data_dir.display()
+        data_dir.display(),
+        crate::suggested_config_path().display()
     ))
 }
 
@@ -185,8 +186,19 @@ fn generate_service_cert(
         }
     }
 
-    if sans.is_empty() {
-        return Err("no valid service names for TLS cert".into());
+    // Loopback IP SANs so browsers can reach DoH at https://127.0.0.1/dns-query
+    sans.push(SanType::IpAddress(std::net::IpAddr::V4(
+        std::net::Ipv4Addr::LOCALHOST,
+    )));
+    sans.push(SanType::IpAddress(std::net::IpAddr::V6(
+        std::net::Ipv6Addr::LOCALHOST,
+    )));
+
+    for name in ["localhost", tld] {
+        match name.to_string().try_into() {
+            Ok(ia5) => sans.push(SanType::DnsName(ia5)),
+            Err(e) => warn!("invalid SAN {}: {}", name, e),
+        }
     }
 
     params.subject_alt_names = sans;
@@ -239,4 +251,72 @@ mod tests {
         let err: crate::Error = "rcgen failure".into();
         assert!(try_data_dir_advisory(&err, &PathBuf::from("/x")).is_none());
     }
+
+    #[test]
+    fn service_cert_contains_expected_sans() {
+        use x509_parser::prelude::GeneralName;
+
+        let dir = std::env::temp_dir().join(format!("numa-test-san-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&dir);
+        let (ca_der, issuer) = ensure_ca(&dir).unwrap();
+
+        let names = vec!["grafana".into(), "router".into()];
+        let (chain, _) = generate_service_cert(&ca_der, &issuer, "numa", &names).unwrap();
+        assert_eq!(chain.len(), 2, "chain should be [leaf, CA]");
+
+        let (_, cert) = x509_parser::parse_x509_certificate(chain[0].as_ref()).unwrap();
+        let san = cert
+            .tbs_certificate
+            .subject_alternative_name()
+            .unwrap()
+            .unwrap();
+
+        let dns: Vec<&str> = san
+            .value
+            .general_names
+            .iter()
+            .filter_map(|gn| match gn {
+                GeneralName::DNSName(s) => Some(*s),
+                _ => None,
+            })
+            .collect();
+
+        let ips: Vec<std::net::IpAddr> = san
+            .value
+            .general_names
+            .iter()
+            .filter_map(|gn| match gn {
+                GeneralName::IPAddress(b) => match b.len() {
+                    4 => Some(std::net::IpAddr::V4(std::net::Ipv4Addr::new(
+                        b[0], b[1], b[2], b[3],
+                    ))),
+                    16 => {
+                        let a: [u8; 16] = (*b).try_into().unwrap();
+                        Some(std::net::IpAddr::V6(std::net::Ipv6Addr::from(a)))
+                    }
+                    _ => None,
+                },
+                _ => None,
+            })
+            .collect();
+
+        // DNS SANs
+        assert!(dns.contains(&"*.numa"), "missing wildcard SAN");
+        assert!(dns.contains(&"grafana.numa"), "missing service SAN");
+        assert!(dns.contains(&"router.numa"), "missing service SAN");
+        assert!(dns.contains(&"localhost"), "missing localhost SAN");
+        assert!(dns.contains(&"numa"), "missing bare TLD SAN");
+
+        // IP SANs
+        assert!(
+            ips.contains(&std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST)),
+            "missing 127.0.0.1 SAN"
+        );
+        assert!(
+            ips.contains(&std::net::IpAddr::V6(std::net::Ipv6Addr::LOCALHOST)),
+            "missing ::1 SAN"
+        );
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
 }

src/windows_service.rs

@@ -0,0 +1,147 @@
+//! Windows service wrapper.
+//!
+//! Lets the `numa.exe` binary act as a real Windows service registered with
+//! the Service Control Manager (SCM). Invoked via `numa.exe --service` (the
+//! form that `sc create … binPath=` uses).
+//!
+//! Interactive runs (`numa.exe`, `numa.exe run`, `numa.exe install`) do not
+//! go through this module — they keep their existing console-attached
+//! behaviour.
+
+use std::ffi::OsString;
+use std::sync::mpsc;
+use std::time::Duration;
+
+use windows_service::service::{
+    ServiceControl, ServiceControlAccept, ServiceExitCode, ServiceState, ServiceStatus, ServiceType,
+};
+use windows_service::service_control_handler::{self, ServiceControlHandlerResult};
+use windows_service::{define_windows_service, service_dispatcher};
+
+pub const SERVICE_NAME: &str = "Numa";
+
+define_windows_service!(ffi_service_main, service_main);
+
+/// Entry point the SCM hands control to after `StartServiceCtrlDispatcherW`.
+/// Any panic here vanishes silently into the service host — log instead of
+/// unwrapping.
+fn service_main(_arguments: Vec<OsString>) {
+    if let Err(e) = run_service() {
+        log::error!("numa service exited with error: {:?}", e);
+    }
+}
+
+fn run_service() -> windows_service::Result<()> {
+    let (shutdown_tx, shutdown_rx) = mpsc::channel::<()>();
+
+    let event_handler = move |control_event| -> ServiceControlHandlerResult {
+        match control_event {
+            ServiceControl::Stop | ServiceControl::Shutdown => {
+                let _ = shutdown_tx.send(());
+                ServiceControlHandlerResult::NoError
+            }
+            ServiceControl::Interrogate => ServiceControlHandlerResult::NoError,
+            _ => ServiceControlHandlerResult::NotImplemented,
+        }
+    };
+
+    let status_handle = service_control_handler::register(SERVICE_NAME, event_handler)?;
+
+    status_handle.set_service_status(ServiceStatus {
+        service_type: ServiceType::OWN_PROCESS,
+        current_state: ServiceState::Running,
+        controls_accepted: ServiceControlAccept::STOP | ServiceControlAccept::SHUTDOWN,
+        exit_code: ServiceExitCode::Win32(0),
+        checkpoint: 0,
+        wait_hint: Duration::default(),
+        process_id: None,
+    })?;
+
+    // Spin up a multi-threaded tokio runtime and run the server on it. A
+    // dedicated thread runs the runtime so this function can return cleanly
+    // once the SCM tells us to stop — we can't block the dispatcher thread
+    // forever without preventing graceful shutdown.
+    let config_path = service_config_path();
+    let (server_done_tx, server_done_rx) = mpsc::channel::<()>();
+
+    let server_thread = std::thread::spawn(move || {
+        let runtime = match tokio::runtime::Builder::new_multi_thread()
+            .enable_all()
+            .build()
+        {
+            Ok(rt) => rt,
+            Err(e) => {
+                log::error!("failed to build tokio runtime: {}", e);
+                let _ = server_done_tx.send(());
+                return;
+            }
+        };
+
+        if let Err(e) = runtime.block_on(crate::serve::run(config_path)) {
+            log::error!("numa serve exited with error: {}", e);
+        }
+        let _ = server_done_tx.send(());
+    });
+
+    // Wait for the API to be ready, then ensure DNS points at localhost.
+    // On first boot after install (Dnscache was disabled, reboot freed
+    // port 53), the installer deferred the DNS redirect — do it now.
+    let api_up = (0..20).any(|i| {
+        if i > 0 {
+            std::thread::sleep(Duration::from_millis(500));
+        }
+        std::net::TcpStream::connect(("127.0.0.1", crate::config::DEFAULT_API_PORT)).is_ok()
+    });
+    if api_up {
+        if let Err(e) = crate::system_dns::redirect_dns_to_localhost() {
+            log::warn!("could not redirect DNS to localhost: {}", e);
+        }
+    } else {
+        log::error!("numa API did not start within 10s — DNS not redirected");
+    }
+
+    // Wait for either SCM stop or server termination.
+    loop {
+        if shutdown_rx.recv_timeout(Duration::from_millis(500)).is_ok() {
+            break;
+        }
+        if server_done_rx.try_recv().is_ok() {
+            break;
+        }
+    }
+
+    // The server's tokio runtime runs detached inside server_thread. Abandon
+    // it — the process is about to report Stopped and the SCM will terminate
+    // us if we linger. Future work: plumb a cancellation signal into
+    // serve::run() for a clean teardown of listeners and in-flight queries.
+    drop(server_thread);
+
+    status_handle.set_service_status(ServiceStatus {
+        service_type: ServiceType::OWN_PROCESS,
+        current_state: ServiceState::Stopped,
+        controls_accepted: ServiceControlAccept::empty(),
+        exit_code: ServiceExitCode::Win32(0),
+        checkpoint: 0,
+        wait_hint: Duration::default(),
+        process_id: None,
+    })?;
+
+    Ok(())
+}
+
+/// Hand control to the SCM dispatcher. Blocks until the service stops.
+/// Call only from the `--service` command path — interactive invocations
+/// will hang here waiting for an SCM that isn't talking to them.
+pub fn run_as_service() -> windows_service::Result<()> {
+    service_dispatcher::start(SERVICE_NAME, ffi_service_main)
+}
+
+/// Path to the config file used when running under SCM. SCM launches the
+/// service with SYSTEM's working directory (usually `C:\Windows\System32`),
+/// so a relative `numa.toml` lookup won't find anything meaningful.
+fn service_config_path() -> String {
+    crate::data_dir()
+        .join("numa.toml")
+        .to_string_lossy()
+        .into_owned()
+}

tests/docker/hold53.py

@@ -0,0 +1,5 @@
+import socket, signal
+s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 0)
+s.bind(("", 53))
+signal.pause()

tests/docker/install-systemd.sh

@@ -0,0 +1,288 @@
+#!/usr/bin/env bash
+#
+# Systemd service install verification for the DynamicUser-based Linux
+# service unit. Stands up a privileged ubuntu:24.04 container with systemd
+# as PID 1, builds numa inside, runs three scenarios that CI does not:
+#
+#   A. Fresh install — every advertised port is not just bound but
+#      functional (DNS resolves on :53, TLS handshake validates against
+#      numa's CA on :853/:443, HTTP responds on :80, API on :5380).
+#   B. Upgrade from pre-drop layout (root-owned /var/lib/numa) preserves
+#      the CA fingerprint — users' browser-installed CA trust survives.
+#   C. Install from a 0700 source directory stages the binary under
+#      /usr/local/bin/numa and the service starts from there.
+#
+# First run is slow (~5-10 min): image pull + apt + cold cargo build.
+# Subsequent runs reuse cached docker volumes for cargo + target (~30s).
+#
+# Requirements: docker
+# Usage:        ./tests/docker/install-systemd.sh
+
+set -u
+set -o pipefail
+
+GREEN="\033[32m"; RED="\033[31m"; RESET="\033[0m"
+
+pass() { printf "  ${GREEN}PASS${RESET}: %s\n" "$*"; }
+fail() { printf "  ${RED}FAIL${RESET}: %s\n" "$*"; FAIL=1; }
+
+# ============================================================
+# Mode B: running inside the systemd container — run scenarios
+# ============================================================
+if [ "${NUMA_INSIDE:-}" = "1" ]; then
+    set +e  # assertions report pass/fail, don't abort
+    FAIL=0
+    NUMA=/work/target/release/numa
+
+    reset_state() {
+        "$NUMA" uninstall >/dev/null 2>&1 || true
+        systemctl reset-failed numa 2>/dev/null || true
+        rm -rf /var/lib/numa /var/lib/private/numa /etc/numa /home/builder /usr/local/bin/numa
+        systemctl daemon-reload 2>/dev/null || true
+    }
+
+    main_pid_user() {
+        local pid
+        pid=$(systemctl show -p MainPID --value numa)
+        [ "$pid" != "0" ] || { echo ""; return; }
+        ps -o user= -p "$pid" 2>/dev/null | tr -d ' '
+    }
+
+    # MainPID + user briefly stabilize after a fresh restart. Retry so we
+    # don't race the moment systemd flips the service to "active" vs when
+    # the forked numa process actually owns MainPID.
+    assert_nonroot() {
+        local pid user comm n=0
+        while [ $n -lt 20 ]; do
+            pid=$(systemctl show -p MainPID --value numa)
+            if [ "$pid" != "0" ]; then
+                comm=$(ps -o comm= -p "$pid" 2>/dev/null | tr -d ' ')
+                user=$(ps -o user= -p "$pid" 2>/dev/null | tr -d ' ')
+                if [ "$comm" = "numa" ]; then
+                    if [ "$user" = "root" ]; then
+                        fail "daemon runs as root (expected transient UID)"
+                    else
+                        pass "daemon runs as $user (non-root)"
+                    fi
+                    return
+                fi
+            fi
+            sleep 0.2
+            n=$((n + 1))
+        done
+        fail "numa MainPID did not settle (last: pid=${pid:-?} comm=${comm:-?} user=${user:-?})"
+    }
+
+    # Functional DNS check: just "port 53 bound" isn't enough — systemd-resolved
+    # listens on 127.0.0.53 and would satisfy a bind test. Retries for ~15s
+    # to tolerate cold-start upstream / blocklist warmup.
+    assert_dns_works() {
+        local n=0
+        while [ $n -lt 15 ]; do
+            if dig @127.0.0.1 -p 53 example.com +short +timeout=2 +tries=1 2>/dev/null \
+                 | grep -qE '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'; then
+                pass "DNS resolves on :53 (A record returned)"
+                return
+            fi
+            sleep 1
+            n=$((n + 1))
+        done
+        fail "DNS did not return an A record on :53 within 15s"
+    }
+
+    # TLS handshake: cert must validate against numa's CA when connecting
+    # to a .numa SNI. Catches port-not-bound, wrong cert, missing CA file.
+    assert_tls_handshake() {
+        local port=$1 sni=${2:-numa.numa} out
+        if out=$(openssl s_client -connect "127.0.0.1:${port}" \
+                    -servername "$sni" \
+                    -CAfile /var/lib/numa/ca.pem \
+                    -verify_return_error </dev/null 2>&1); then
+            if echo "$out" | grep -q 'Verify return code: 0 (ok)'; then
+                pass "TLS handshake + cert chain verified on :${port}"
+            else
+                fail "TLS handshake on :${port} did not report 'Verify return code: 0'"
+            fi
+        else
+            fail "openssl s_client failed connecting to :${port}"
+        fi
+    }
+
+    assert_http_responds() {
+        local code
+        code=$(curl -s -o /dev/null -w "%{http_code}" --max-time 3 http://127.0.0.1/ || echo 000)
+        if [ "$code" != "000" ]; then
+            pass "HTTP responds on :80 (status $code)"
+        else
+            fail "HTTP :80 connection failed"
+        fi
+    }
+
+    assert_api_healthy() {
+        if curl -sf --max-time 3 http://127.0.0.1:5380/health >/dev/null; then
+            pass "API /health OK on :5380"
+        else
+            fail "API /health failed on :5380"
+        fi
+    }
+
+    ca_fingerprint() {
+        openssl x509 -in /var/lib/numa/ca.pem -noout -fingerprint -sha256 2>/dev/null \
+            | sed 's/.*=//'
+    }
+
+    wait_active() {
+        local n=0
+        while [ $n -lt 20 ]; do
+            systemctl is-active --quiet numa && return 0
+            sleep 0.5
+            n=$((n + 1))
+        done
+        fail "service did not become active within 10s"
+        systemctl status numa --no-pager -l 2>&1 | head -20 || true
+        return 1
+    }
+
+    # ---- Scenario A ----
+    printf "\n=== Scenario A: fresh install — every advertised port is functional ===\n"
+    reset_state
+    "$NUMA" install >/tmp/installA.log 2>&1 || { fail "install failed"; tail -20 /tmp/installA.log; }
+    wait_active || true
+    assert_nonroot
+    assert_dns_works
+    assert_tls_handshake 853
+    assert_tls_handshake 443
+    assert_http_responds
+    assert_api_healthy
+
+    # ---- Scenario B ----
+    # Pre-drop installs left /var/lib/numa as a plain root-owned tree.
+    # Flattening the current DynamicUser layout back into that shape
+    # simulates the upgrade path without needing an actual old binary.
+    printf "\n=== Scenario B: CA fingerprint survives upgrade from pre-drop layout ===\n"
+    fp_before=$(ca_fingerprint)
+    if [ -z "$fp_before" ]; then
+        fail "could not read initial CA fingerprint (skipping scenario B)"
+    else
+        echo "  CA fingerprint before: $fp_before"
+        "$NUMA" uninstall >/dev/null 2>&1 || true
+        tmp=$(mktemp -d)
+        cp -a /var/lib/private/numa/. "$tmp"/ 2>/dev/null || true
+        rm -rf /var/lib/numa /var/lib/private/numa
+        mv "$tmp" /var/lib/numa
+        chown -R root:root /var/lib/numa
+        chmod 755 /var/lib/numa
+        [ -f /var/lib/numa/ca.pem ] || fail "ca.pem missing from seeded legacy tree"
+
+        "$NUMA" install >/tmp/installB.log 2>&1 || { fail "upgrade install failed"; tail -20 /tmp/installB.log; }
+        wait_active || true
+        assert_nonroot
+        fp_after=$(ca_fingerprint)
+        if [ -z "$fp_after" ]; then
+            fail "could not read CA fingerprint after upgrade"
+        elif [ "$fp_before" = "$fp_after" ]; then
+            pass "CA fingerprint preserved across upgrade"
+        else
+            fail "CA fingerprint changed: before=$fp_before after=$fp_after"
+        fi
+        assert_dns_works
+    fi
+
+    # ---- Scenario C ----
+    printf "\n=== Scenario C: install from unreachable source stages binary to /usr/local/bin ===\n"
+    reset_state
+    mkdir -p /home/builder
+    chmod 700 /home/builder
+    cp "$NUMA" /home/builder/numa
+    chmod 755 /home/builder/numa
+    /home/builder/numa install >/tmp/installC.log 2>&1 || { fail "install failed"; tail -20 /tmp/installC.log; }
+    wait_active || true
+    if [ -x /usr/local/bin/numa ]; then
+        pass "binary staged to /usr/local/bin/numa"
+    else
+        fail "/usr/local/bin/numa missing after install from 0700 source"
+    fi
+    exec_line=$(grep '^ExecStart=' /etc/systemd/system/numa.service 2>/dev/null || echo "ExecStart=<unit missing>")
+    if echo "$exec_line" | grep -q '/usr/local/bin/numa'; then
+        pass "unit ExecStart points to staged path"
+    else
+        fail "unit ExecStart wrong: $exec_line"
+    fi
+    assert_nonroot
+    assert_dns_works
+
+    reset_state
+    rm -rf /home/builder
+    echo
+    if [ "$FAIL" -eq 0 ]; then
+        printf "${GREEN}── all scenarios passed ──${RESET}\n"
+        exit 0
+    else
+        printf "${RED}── some scenarios failed ──${RESET}\n"
+        exit 1
+    fi
+fi
+
+# ============================================================
+# Mode A: host-side bootstrap
+# ============================================================
+set -e
+cd "$(dirname "$0")/../.."
+
+IMAGE=numa-install-systemd:local
+CONTAINER="numa-install-systemd-$$"
+trap 'docker rm -f "$CONTAINER" >/dev/null 2>&1 || true' EXIT
+
+echo "── building systemd-in-container image (cached after first run) ──"
+docker build --quiet -t "$IMAGE" -f - . <<'DOCKERFILE' >/dev/null
+FROM ubuntu:24.04
+ENV DEBIAN_FRONTEND=noninteractive
+RUN apt-get update -qq && apt-get install -y -qq \
+      systemd systemd-sysv systemd-resolved \
+      ca-certificates curl build-essential \
+      pkg-config libssl-dev cmake make perl \
+      dnsutils iproute2 openssl \
+    && rm -rf /var/lib/apt/lists/* \
+    && for u in dev-hugepages.mount sys-fs-fuse-connections.mount \
+                systemd-logind.service getty.target console-getty.service; do \
+         systemctl mask $u; \
+       done
+STOPSIGNAL SIGRTMIN+3
+CMD ["/lib/systemd/systemd"]
+DOCKERFILE
+
+echo "── starting systemd container ──"
+docker run -d --name "$CONTAINER" \
+    --privileged --cgroupns=host \
+    --tmpfs /run --tmpfs /run/lock --tmpfs /tmp:exec \
+    -v "$PWD:/src:ro" \
+    -v numa-install-systemd-cargo:/root/.cargo \
+    -v numa-install-systemd-work:/work \
+    "$IMAGE" >/dev/null
+
+# Wait for systemd to be up
+for _ in $(seq 1 30); do
+    state=$(docker exec "$CONTAINER" systemctl is-system-running 2>&1 || true)
+    case "$state" in running|degraded) break ;; esac
+    sleep 0.5
+done
+
+echo "── copying source into /work (writable) ──"
+docker exec "$CONTAINER" bash -c '
+mkdir -p /work
+tar -C /src --exclude=./target --exclude=./.git --exclude=./.claude -cf - . | tar -C /work -xf -
+'
+
+echo "── rustup + cargo build --release --locked ──"
+docker exec "$CONTAINER" bash -c '
+set -e
+if ! command -v cargo &>/dev/null; then
+    curl -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal --quiet
+fi
+. "$HOME/.cargo/env"
+cd /work
+cargo build --release --locked 2>&1 | tail -5
+'
+
+echo "── running scenarios ──"
+docker exec -e NUMA_INSIDE=1 "$CONTAINER" bash /src/tests/docker/install-systemd.sh

tests/docker/issue-81.sh

@@ -0,0 +1,164 @@
+#!/usr/bin/env bash
+#
+# End-to-end validation of the issue #81 fix (config path advisory).
+#
+# Builds numa from two source trees — the buggy baseline and the fix
+# candidate — inside one debian:bookworm container, then runs four
+# scenarios to prove:
+#
+#   1. replication/main  — reporter's sequence, bug confirmed
+#   2. replication/fix   — reporter's sequence, bug is gone
+#   3. existing/main     — pre-installed config at FHS data dir still loads
+#   4. existing/fix      — same, unchanged by the fix (no regression)
+#
+# Scenarios 3 and 4 guard against the fear that the fix might change
+# candidate order and break existing daemon installs (including the
+# macOS Homebrew-prefix layout at /usr/local/var/numa/).
+#
+# Usage:
+#   MAIN_SRC=/path/to/main-checkout FIX_SRC=/path/to/fix-worktree \
+#     ./tests/docker/issue-81.sh
+#
+# Defaults: MAIN_SRC = $(git rev-parse --show-toplevel), FIX_SRC = same.
+
+set -euo pipefail
+
+MAIN_SRC="${MAIN_SRC:-$(git rev-parse --show-toplevel)}"
+FIX_SRC="${FIX_SRC:-$MAIN_SRC}"
+
+GREEN="\033[32m"; RED="\033[31m"; RESET="\033[0m"
+
+echo "── issue #81 validation ──"
+echo "  main: $MAIN_SRC"
+echo "  fix:  $FIX_SRC"
+echo
+
+docker run --rm \
+    --platform linux/amd64 \
+    -v "$MAIN_SRC:/main:ro" \
+    -v "$FIX_SRC:/fix:ro" \
+    -v "$(dirname "$0")/hold53.py:/tmp/hold53.py:ro" \
+    -v numa-port53-cargo:/root/.cargo \
+    -v numa-port53-target:/work/target \
+    debian:bookworm bash -c '
+set -euo pipefail
+
+# Paths and ports used by all scenarios — keep in one place so the
+# heredocs and the verdict greps cannot drift.
+XDG_CONFIG="/root/.config/numa/numa.toml"
+FHS_CONFIG="/var/lib/numa/numa.toml"
+TEST_PORT="5354"
+TEST_API_PORT="5380"
+
+apt-get update -qq && apt-get install -y -qq curl build-essential python3 2>&1 | tail -1
+if ! command -v cargo &>/dev/null; then
+    curl -sSf https://sh.rustup.rs | sh -s -- -y --profile minimal --quiet
+fi
+. "$HOME/.cargo/env"
+
+build_from() {
+    local label="$1"; local src="$2"
+    mkdir -p "/work/$label"
+    tar -C "$src" --exclude=./target --exclude=./.git -cf - . | tar -C "/work/$label" -xf -
+    (cd "/work/$label" && cargo build --release --locked 2>&1 | tail -1)
+    cp "/work/$label/target/release/numa" "/work/numa-$label"
+}
+
+build_from main /main
+build_from fix /fix
+
+holder=0
+stop_holder() {
+    if [ "$holder" -ne 0 ]; then
+        kill "$holder" 2>/dev/null || true
+        wait "$holder" 2>/dev/null || true
+        holder=0
+    fi
+}
+trap stop_holder EXIT
+
+start_holder() {
+    python3 /tmp/hold53.py &
+    holder=$!
+    sleep 0.3
+}
+
+write_test_config() {
+    local path="$1"
+    mkdir -p "$(dirname "$path")"
+    cat > "$path" <<EOF
+[server]
+bind_addr = "127.0.0.1:$TEST_PORT"
+api_port = $TEST_API_PORT
+EOF
+}
+
+verdict() {
+    local label="$1"; local expected="$2"; local file="$3"
+    # "cannot bind to" is printed by the advisory when numa fails to start.
+    # Its absence is a reliable proxy for "numa bound successfully" because
+    # the banner-only log we capture contains no other failure surface.
+    if grep -q "cannot bind to" "$file"; then
+        echo "  [$label] did not bind $TEST_PORT — numa ignored the XDG config"
+        [ "$expected" = "ignored" ] && return 0 || return 1
+    else
+        echo "  [$label] bound $TEST_PORT — config loaded"
+        [ "$expected" = "bound" ] && return 0 || return 1
+    fi
+}
+
+scenario_replication() {
+    local label="$1"; local bin="/work/numa-$label"; local expected="$2"
+    echo
+    echo "════════ REPLICATION / $label ════════"
+    rm -rf /root/.config/numa /var/lib/numa
+    mkdir -p "$(dirname "$XDG_CONFIG")"
+
+    start_holder
+    set +e
+    timeout 5 "$bin" > /tmp/run1.txt 2>&1
+    set -e
+    echo "── step 1: advisory printed by $label ──"
+    grep -E "Create .* with:" /tmp/run1.txt | sed "s/^/  /" || echo "  <no advisory line>"
+
+    write_test_config "$XDG_CONFIG"
+    echo "── step 2: wrote config at $XDG_CONFIG ──"
+
+    set +e
+    timeout 3 "$bin" > /tmp/run2.txt 2>&1
+    set -e
+    stop_holder
+
+    verdict "$label" "$expected" /tmp/run2.txt
+}
+
+scenario_existing_install() {
+    local label="$1"; local bin="/work/numa-$label"
+    echo
+    echo "════════ EXISTING INSTALL / $label ════════"
+    rm -rf /root/.config/numa /var/lib/numa
+    write_test_config "$FHS_CONFIG"
+
+    start_holder
+    set +e
+    timeout 3 "$bin" > /tmp/run.txt 2>&1
+    set -e
+    stop_holder
+
+    verdict "$label" "bound" /tmp/run.txt
+}
+
+RC=0
+scenario_replication main ignored || RC=1
+scenario_replication fix bound || RC=1
+scenario_existing_install main || RC=1
+scenario_existing_install fix || RC=1
+
+echo
+if [ "$RC" -eq 0 ]; then
+    echo "── all scenarios matched expectations ──"
+else
+    echo "── FAILURE: one or more scenarios diverged ──"
+fi
+exit $RC
+'

tests/integration.sh

@@ -1,7 +1,10 @@
 #!/usr/bin/env bash
 # Integration test suite for Numa
 # Runs a test instance on port 5354, validates all features, exits with status.
-# Usage: ./tests/integration.sh [release|debug]
+# Usage:
+#   ./tests/integration.sh [release|debug]       # all suites
+#   SUITES=7 ./tests/integration.sh              # only Suite 7
+#   SUITES=1,3,7 ./tests/integration.sh          # Suites 1, 3, and 7
 
 set -euo pipefail
 
@@ -14,6 +17,14 @@ LOG="/tmp/numa-integration-test.log"
 PASSED=0
 FAILED=0
 
+# Suite filter: empty runs all; comma list runs a subset.
+SUITES="${SUITES:-}"
+should_run_suite() {
+    [ -z "$SUITES" ] && return 0
+    case ",$SUITES," in *",$1,"*) return 0;; esac
+    return 1
+}
+
 # Colors
 GREEN="\033[32m"
 RED="\033[31m"
@@ -53,7 +64,17 @@ CONF
     echo "Starting Numa on :$PORT ($SUITE_NAME)..."
     RUST_LOG=info "$BINARY" "$CONFIG" > "$LOG" 2>&1 &
     NUMA_PID=$!
-    sleep 4
+    sleep 2
+
+    # Wait for blocklist to load (if blocking is enabled in this suite)
+    if echo "$SUITE_CONFIG" | grep -q 'enabled = true'; then
+        for i in $(seq 1 20); do
+            LOADED=$(curl -sf http://127.0.0.1:$API_PORT/blocking/stats 2>/dev/null \
+                | grep -o '"domains_loaded":[0-9]*' | cut -d: -f2)
+            if [ "${LOADED:-0}" -gt 0 ]; then break; fi
+            sleep 1
+        done
+    fi
 
     if ! kill -0 "$NUMA_PID" 2>/dev/null; then
         echo "Failed to start Numa:"
@@ -156,6 +177,7 @@ CONF
 }
 
 # ---- Suite 1: Recursive mode + DNSSEC ----
+if should_run_suite 1; then
 echo ""
 echo "╔══════════════════════════════════════════╗"
 echo "║  Suite 1: Recursive + DNSSEC + Blocking  ║"
@@ -224,7 +246,10 @@ kill "$NUMA_PID" 2>/dev/null || true
 wait "$NUMA_PID" 2>/dev/null || true
 sleep 1
 
+fi  # end Suite 1
+
 # ---- Suite 2: Forward mode (backward compat) ----
+if should_run_suite 2; then
 echo ""
 echo "╔══════════════════════════════════════════╗"
 echo "║  Suite 2: Forward (DoH) + Blocking       ║"
@@ -251,7 +276,10 @@ enabled = true
 enabled = false
 "
 
+fi  # end Suite 2
+
 # ---- Suite 3: Forward UDP (plain, no DoH) ----
+if should_run_suite 3; then
 echo ""
 echo "╔══════════════════════════════════════════╗"
 echo "║  Suite 3: Forward (UDP) + No Blocking    ║"
@@ -297,7 +325,10 @@ kill "$NUMA_PID" 2>/dev/null || true
 wait "$NUMA_PID" 2>/dev/null || true
 sleep 1
 
+fi  # end Suite 3
+
 # ---- Suite 4: Local zones + Overrides API ----
+if should_run_suite 4; then
 echo ""
 echo "╔══════════════════════════════════════════╗"
 echo "║  Suite 4: Local Zones + Overrides API    ║"
@@ -406,7 +437,10 @@ kill "$NUMA_PID" 2>/dev/null || true
 wait "$NUMA_PID" 2>/dev/null || true
 sleep 1
 
+fi  # end Suite 4
+
 # ---- Suite 5: DNS-over-TLS (RFC 7858) ----
+if should_run_suite 5; then
 echo ""
 echo "╔══════════════════════════════════════════╗"
 echo "║  Suite 5: DNS-over-TLS (RFC 7858)        ║"
@@ -528,7 +562,10 @@ CONF
 fi
 sleep 1
 
+fi  # end Suite 5
+
 # ---- Suite 6: Proxy + DoT coexistence ----
+if should_run_suite 6; then
 echo ""
 echo "╔══════════════════════════════════════════╗"
 echo "║  Suite 6: Proxy + DoT Coexistence        ║"
@@ -622,6 +659,54 @@ CONF
             "10.0.0.1" \
             "$($KDIG +short dot-test.example A 2>/dev/null)"
 
+        echo ""
+        echo "=== DNS-over-HTTPS (RFC 8484) ==="
+
+        DOH_QUERY_FILE=/tmp/numa-doh-query.bin
+        DOH_RESP_FILE=/tmp/numa-doh-resp.bin
+
+        # Build DNS wire-format query for dot-test.example A
+        printf '\x00\x01\x01\x00\x00\x01\x00\x00\x00\x00\x00\x00\x08dot-test\x07example\x00\x00\x01\x00\x01' > "$DOH_QUERY_FILE"
+
+        # POST valid DoH query
+        DOH_CODE=$(curl -sk -X POST \
+            --resolve "numa.numa:$PROXY_HTTPS_PORT:127.0.0.1" \
+            -H "Content-Type: application/dns-message" \
+            --data-binary @"$DOH_QUERY_FILE" \
+            --cacert "$CA" \
+            -o "$DOH_RESP_FILE" \
+            -w "%{http_code}" \
+            "https://numa.numa:$PROXY_HTTPS_PORT/dns-query")
+        check "DoH POST returns HTTP 200" "200" "$DOH_CODE"
+
+        # Check response contains IP 10.0.0.1 (hex: 0a000001)
+        DOH_HEX=$(xxd -p "$DOH_RESP_FILE" | tr -d '\n')
+        if echo "$DOH_HEX" | grep -q "0a000001"; then
+            check "DoH response resolves dot-test.example → 10.0.0.1" "found" "found"
+        else
+            check "DoH response resolves dot-test.example → 10.0.0.1" "0a000001" "$DOH_HEX"
+        fi
+
+        # Wrong Content-Type → 415
+        DOH_CT_CODE=$(curl -sk -X POST \
+            -H "Host: numa.numa" \
+            -H "Content-Type: text/plain" \
+            --data-binary @"$DOH_QUERY_FILE" \
+            -o /dev/null -w "%{http_code}" \
+            "https://127.0.0.1:$PROXY_HTTPS_PORT/dns-query")
+        check "DoH wrong Content-Type → 415" "415" "$DOH_CT_CODE"
+
+        # Wrong host → 404 (DoH only serves numa.numa)
+        DOH_HOST_CODE=$(curl -sk -X POST \
+            -H "Host: foo.numa" \
+            -H "Content-Type: application/dns-message" \
+            --data-binary @"$DOH_QUERY_FILE" \
+            -o /dev/null -w "%{http_code}" \
+            "https://127.0.0.1:$PROXY_HTTPS_PORT/dns-query")
+        check "DoH wrong host → 404" "404" "$DOH_HOST_CODE"
+
+        rm -f "$DOH_QUERY_FILE" "$DOH_RESP_FILE"
+
         echo ""
         echo "=== Proxy TLS works with DoT enabled ==="
 
@@ -640,6 +725,332 @@ CONF
     rm -rf "$NUMA_DATA"
 fi
 
+fi  # end Suite 6
+
+# ---- Suite 7: filter_aaaa (IPv4-only networks) ----
+if should_run_suite 7; then
+echo ""
+echo "╔══════════════════════════════════════════╗"
+echo "║  Suite 7: filter_aaaa                    ║"
+echo "╚══════════════════════════════════════════╝"
+
+# Config A — filter on, with a local AAAA zone to prove local data bypass.
+cat > "$CONFIG" << 'CONF'
+[server]
+bind_addr = "127.0.0.1:5354"
+api_port = 5381
+filter_aaaa = true
+
+[upstream]
+mode = "forward"
+address = "9.9.9.9"
+port = 53
+
+[cache]
+max_entries = 10000
+
+[blocking]
+enabled = false
+
+[proxy]
+enabled = false
+
+[[zones]]
+domain = "v6.test"
+record_type = "AAAA"
+value = "2001:db8::1"
+ttl = 60
+CONF
+
+RUST_LOG=info "$BINARY" "$CONFIG" > "$LOG" 2>&1 &
+NUMA_PID=$!
+sleep 3
+
+DIG="dig @127.0.0.1 -p $PORT +time=5 +tries=1"
+
+echo ""
+echo "=== filter_aaaa = true ==="
+
+# A queries must be untouched.
+check "A record resolves under filter_aaaa" \
+    "." \
+    "$($DIG google.com A +short | head -1)"
+
+# AAAA must be NOERROR (NODATA), not NXDOMAIN, not SERVFAIL.
+check "AAAA returns NOERROR (not NXDOMAIN)" \
+    "status: NOERROR" \
+    "$($DIG google.com AAAA 2>&1 | grep 'status:')"
+
+check "AAAA returns zero answers (NODATA shape)" \
+    "ANSWER: 0" \
+    "$($DIG google.com AAAA 2>&1 | grep -oE 'ANSWER: [0-9]+' | head -1)"
+
+# Local zone AAAA must survive the filter (PR claim: local data bypasses).
+check "Local [[zones]] AAAA bypasses filter" \
+    "2001:db8::1" \
+    "$($DIG v6.test AAAA +short)"
+
+# HTTPS RR: ipv6hint (SvcParamKey 6) must be stripped. Query as `type65`
+# because dig 9.10.6 (macOS) misparses `HTTPS` as a domain name; `type65`
+# works on both 9.10.6 and 9.18. Assert on the raw rdata hex (RFC 3597
+# generic format), since dig 9.10.6 doesn't pretty-print HTTPS params.
+# cloudflare.com's ipv6hint values sit under the 2606:4700 prefix —
+# checking that `26064700` is absent from the rdata hex is a precise,
+# upstream-stable signal that the TLV was stripped.
+HTTPS_OUT=$($DIG cloudflare.com type65 2>&1)
+if echo "$HTTPS_OUT" | grep -qE "cloudflare\.com\..*IN[[:space:]]+TYPE65"; then
+    HTTPS_HEX=$(echo "$HTTPS_OUT" | grep -A5 "IN[[:space:]]*TYPE65" | tr -d " \t\n")
+    if echo "$HTTPS_HEX" | grep -qi "26064700"; then
+        check "HTTPS ipv6hint stripped (2606:4700 absent from rdata)" "absent" "present"
+    else
+        check "HTTPS ipv6hint stripped (2606:4700 absent from rdata)" "absent" "absent"
+    fi
+else
+    # Upstream didn't return an HTTPS record — skip rather than false-pass.
+    printf "  ${DIM}~ HTTPS ipv6hint stripped (skipped: no HTTPS RR returned by upstream)${RESET}\n"
+fi
+
+kill "$NUMA_PID" 2>/dev/null || true
+wait "$NUMA_PID" 2>/dev/null || true
+sleep 1
+
+# Config B — filter off. Regression guard: prove AAAA answers come back
+# when the flag isn't set, so a network failure in Config A can't silently
+# pass as "filter working".
+cat > "$CONFIG" << 'CONF'
+[server]
+bind_addr = "127.0.0.1:5354"
+api_port = 5381
+
+[upstream]
+mode = "forward"
+address = "9.9.9.9"
+port = 53
+
+[cache]
+max_entries = 10000
+
+[blocking]
+enabled = false
+
+[proxy]
+enabled = false
+CONF
+
+RUST_LOG=info "$BINARY" "$CONFIG" > "$LOG" 2>&1 &
+NUMA_PID=$!
+sleep 3
+
+echo ""
+echo "=== filter_aaaa unset (regression guard) ==="
+
+check "AAAA returns real answers with filter off" \
+    ":" \
+    "$($DIG google.com AAAA +short | head -1)"
+
+kill "$NUMA_PID" 2>/dev/null || true
+wait "$NUMA_PID" 2>/dev/null || true
+sleep 1
+
+fi  # end Suite 7
+
+# ---- Suite 8: ODoH (Oblivious DoH via public relay + target) ----
+# Exercises the full client pipeline: /.well-known/odohconfigs fetch,
+# HPKE seal/unseal, URL-query target routing (RFC 9230 §5), dashboard
+# QueryPath::Odoh counter. Depends on the public ecosystem being up —
+# the probe-odoh-ecosystem.sh script guards against flaky runs.
+if should_run_suite 8; then
+echo ""
+echo "╔══════════════════════════════════════════╗"
+echo "║  Suite 8: ODoH (Anonymous DNS)           ║"
+echo "╚══════════════════════════════════════════╝"
+
+run_test_suite "ODoH via edgecompute.app relay → Cloudflare target" "
+[server]
+bind_addr = \"127.0.0.1:5354\"
+api_port = 5381
+
+[upstream]
+mode = \"odoh\"
+relay = \"https://odoh-relay.edgecompute.app/proxy\"
+target = \"https://odoh.cloudflare-dns.com/dns-query\"
+
+[cache]
+max_entries = 10000
+min_ttl = 60
+max_ttl = 86400
+
+[blocking]
+enabled = false
+
+[proxy]
+enabled = false
+"
+
+# Re-start briefly to assert ODoH-specific observability: the odoh counter
+# has to tick above zero after a query, and the stats label has to reflect
+# the oblivious path. These guard against silent regressions in the
+# QueryPath::Odoh tagging and the /stats serialisation.
+RUST_LOG=info "$BINARY" "$CONFIG" > "$LOG" 2>&1 &
+NUMA_PID=$!
+for _ in $(seq 1 30); do
+    curl -sf "http://127.0.0.1:$API_PORT/health" >/dev/null 2>&1 && break
+    sleep 0.1
+done
+
+$DIG example.com A +short > /dev/null 2>&1 || true
+sleep 1
+
+STATS=$(curl -sf http://127.0.0.1:$API_PORT/stats 2>/dev/null)
+# upstream_transport.odoh lives inside the upstream_transport object.
+ODOH_COUNT=$(echo "$STATS" | grep -o '"upstream_transport":{[^}]*}' \
+    | grep -o '"odoh":[0-9]*' | cut -d: -f2)
+check "upstream_transport.odoh > 0 after a query" "[1-9]" "${ODOH_COUNT:-0}"
+
+check "Upstream label advertises odoh://" \
+    "odoh://" \
+    "$(echo "$STATS" | grep -o '"upstream":"[^"]*"')"
+
+check "Stats mode field is 'odoh'" \
+    '"mode":"odoh"' \
+    "$(echo "$STATS" | grep -o '"mode":"odoh"')"
+
+# Strict-mode failure path: a clearly-unreachable relay must produce
+# SERVFAIL without silent downgrade. We hijack the config to point at
+# an .invalid host so we don't rely on external uptime.
+kill "$NUMA_PID" 2>/dev/null || true
+wait "$NUMA_PID" 2>/dev/null || true
+sleep 1
+
+cat > "$CONFIG" << 'CONF'
+[server]
+bind_addr = "127.0.0.1:5354"
+api_port = 5381
+
+[upstream]
+mode = "odoh"
+relay = "https://relay.invalid/proxy"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+strict = true
+
+[cache]
+max_entries = 10000
+
+[blocking]
+enabled = false
+
+[proxy]
+enabled = false
+CONF
+
+RUST_LOG=info "$BINARY" "$CONFIG" > "$LOG" 2>&1 &
+NUMA_PID=$!
+for _ in $(seq 1 30); do
+    curl -sf "http://127.0.0.1:$API_PORT/health" >/dev/null 2>&1 && break
+    sleep 0.1
+done
+
+check "Strict-mode relay outage returns SERVFAIL" \
+    "SERVFAIL" \
+    "$($DIG example.com A 2>&1 | grep 'status:')"
+
+kill "$NUMA_PID" 2>/dev/null || true
+wait "$NUMA_PID" 2>/dev/null || true
+sleep 1
+
+# Negative: relay and target on the same host must be rejected at startup.
+cat > "$CONFIG" << 'CONF'
+[server]
+bind_addr = "127.0.0.1:5354"
+api_port = 5381
+
+[upstream]
+mode = "odoh"
+relay = "https://odoh.cloudflare-dns.com/proxy"
+target = "https://odoh.cloudflare-dns.com/dns-query"
+CONF
+
+STARTUP_OUT=$("$BINARY" "$CONFIG" 2>&1 || true)
+check "Same-host relay+target rejected at startup" \
+    "same host" \
+    "$STARTUP_OUT"
+
+fi  # end Suite 8
+
+# ---- Suite 9: Numa's own ODoH relay (--relay-mode) ----
+# Exercises `numa relay PORT` as a forwarding proxy to a real ODoH target.
+# Validates the RFC 9230 §5 relay behaviour: URL-query routing, content-type
+# gating, body-size cap, and /health observability.
+if should_run_suite 9; then
+echo ""
+echo "╔══════════════════════════════════════════╗"
+echo "║  Suite 9: Numa ODoH Relay (own)          ║"
+echo "╚══════════════════════════════════════════╝"
+
+RELAY_PORT=18443
+"$BINARY" relay $RELAY_PORT > "$LOG" 2>&1 &
+NUMA_PID=$!
+for _ in $(seq 1 30); do
+    curl -sf "http://127.0.0.1:$RELAY_PORT/health" >/dev/null 2>&1 && break
+    sleep 0.1
+done
+
+echo ""
+echo "=== Relay Endpoints ==="
+
+check "Health endpoint returns ok" \
+    "ok" \
+    "$(curl -sf http://127.0.0.1:$RELAY_PORT/health | head -1)"
+
+# Happy path: forwards arbitrary body to Cloudflare's ODoH target. The
+# target will reject the garbage envelope with HTTP 400 — which is exactly
+# what proves our relay faithfully forwarded (otherwise we'd see our own
+# 4xx from the relay itself).
+HAPPY_STATUS=$(curl -sS -o /dev/null -w "%{http_code}" -X POST \
+    -H "Content-Type: application/oblivious-dns-message" \
+    --data-binary "garbage-forwarded-end-to-end" \
+    "http://127.0.0.1:$RELAY_PORT/relay?targethost=odoh.cloudflare-dns.com&targetpath=/dns-query")
+check "Relay forwards to target (target rejects garbage → 400)" \
+    "400" \
+    "$HAPPY_STATUS"
+
+echo ""
+echo "=== Guards ==="
+
+check "Missing content-type → 415" \
+    "415" \
+    "$(curl -sS -o /dev/null -w '%{http_code}' -X POST --data-binary 'x' \
+        'http://127.0.0.1:'$RELAY_PORT'/relay?targethost=odoh.cloudflare-dns.com&targetpath=/dns-query')"
+
+check "Oversized body (>4 KiB) → 413" \
+    "413" \
+    "$(head -c 5000 /dev/urandom | curl -sS -o /dev/null -w '%{http_code}' -X POST \
+        -H 'Content-Type: application/oblivious-dns-message' --data-binary @- \
+        'http://127.0.0.1:'$RELAY_PORT'/relay?targethost=odoh.cloudflare-dns.com&targetpath=/dns-query')"
+
+check "Invalid targethost (no dot) → 400" \
+    "400" \
+    "$(curl -sS -o /dev/null -w '%{http_code}' -X POST \
+        -H 'Content-Type: application/oblivious-dns-message' --data-binary 'x' \
+        'http://127.0.0.1:'$RELAY_PORT'/relay?targethost=invalid&targetpath=/dns-query')"
+
+echo ""
+echo "=== Counters ==="
+
+HEALTH=$(curl -sf "http://127.0.0.1:$RELAY_PORT/health")
+check "Relay counted at least one forwarded_ok" \
+    "[1-9]" \
+    "$(echo "$HEALTH" | grep 'forwarded_ok' | awk '{print $2}')"
+check "Relay counted at least one rejected_bad_request" \
+    "[1-9]" \
+    "$(echo "$HEALTH" | grep 'rejected_bad_request' | awk '{print $2}')"
+
+kill "$NUMA_PID" 2>/dev/null || true
+wait "$NUMA_PID" 2>/dev/null || true
+sleep 1
+
+fi  # end Suite 9
+
 # Summary
 echo ""
 TOTAL=$((PASSED + FAILED))

tests/probe-odoh-ecosystem.sh

@@ -0,0 +1,101 @@
+#!/usr/bin/env bash
+# Probe the public ODoH ecosystem.
+#
+# Source of truth: DNSCrypt's curated list at
+#   https://github.com/DNSCrypt/dnscrypt-resolvers/tree/master/v3
+#   - v3/odoh-servers.md  (ODoH targets)
+#   - v3/odoh-relays.md   (ODoH relays)
+#
+# As of commit 2025-09-16 ("odohrelay-crypto-sx seems to be the only ODoH
+# relay left"), the full public ecosystem is 4 targets + 1 relay. Re-run this
+# script against the upstream list before making any "only N public relays"
+# claim publicly.
+#
+# Usage: ./tests/probe-odoh-ecosystem.sh
+
+set -uo pipefail
+
+GREEN="\033[32m"
+RED="\033[31m"
+YELLOW="\033[33m"
+DIM="\033[90m"
+RESET="\033[0m"
+
+UP=0
+DOWN=0
+
+probe_target() {
+    local name="$1"
+    local host="$2"
+    local url="https://${host}/.well-known/odohconfigs"
+    local start=$(date +%s%N)
+    local headers
+    headers=$(curl -sS -o /tmp/odoh-probe-body -D - --max-time 5 -A "numa-odoh-probe/0.1" "$url" 2>&1) || {
+        DOWN=$((DOWN + 1))
+        printf "  ${RED}✗${RESET} %-25s ${DIM}unreachable${RESET}\n" "$name"
+        return
+    }
+    local elapsed_ms=$((($(date +%s%N) - start) / 1000000))
+    local status
+    status=$(echo "$headers" | head -1 | awk '{print $2}')
+    local ctype
+    ctype=$(echo "$headers" | grep -i '^content-type:' | head -1 | tr -d '\r')
+    local size
+    size=$(stat -f%z /tmp/odoh-probe-body 2>/dev/null || stat -c%s /tmp/odoh-probe-body 2>/dev/null || echo 0)
+
+    if [[ "$status" == "200" ]] && [[ "$size" -gt 0 ]]; then
+        UP=$((UP + 1))
+        printf "  ${GREEN}✓${RESET} %-25s ${DIM}%4dms  %s bytes  %s${RESET}\n" "$name" "$elapsed_ms" "$size" "$ctype"
+    else
+        DOWN=$((DOWN + 1))
+        printf "  ${RED}✗${RESET} %-25s ${DIM}status=%s size=%s${RESET}\n" "$name" "$status" "$size"
+    fi
+    rm -f /tmp/odoh-probe-body
+}
+
+probe_relay() {
+    # Relays don't expose /.well-known/odohconfigs — we just verify TLS reachability
+    # and that the endpoint responds to a malformed POST with an HTTP error
+    # (indicating the relay path exists). A real ODoH validation requires HPKE.
+    local name="$1"
+    local url="$2"
+    local start=$(date +%s%N)
+    local status
+    status=$(curl -sS -o /dev/null -w "%{http_code}" --max-time 5 -A "numa-odoh-probe/0.1" \
+        -X POST -H "Content-Type: application/oblivious-dns-message" \
+        --data-binary "" "$url" 2>&1) || {
+        DOWN=$((DOWN + 1))
+        printf "  ${RED}✗${RESET} %-25s ${DIM}unreachable${RESET}\n" "$name"
+        return
+    }
+    local elapsed_ms=$((($(date +%s%N) - start) / 1000000))
+    # Any 2xx or 4xx means the endpoint is live (TLS works, HTTP responded).
+    # 5xx or 000 (curl failure) means broken.
+    if [[ "$status" =~ ^[24] ]]; then
+        UP=$((UP + 1))
+        printf "  ${GREEN}✓${RESET} %-25s ${DIM}%4dms  status=%s (endpoint live)${RESET}\n" "$name" "$elapsed_ms" "$status"
+    else
+        DOWN=$((DOWN + 1))
+        printf "  ${RED}✗${RESET} %-25s ${DIM}status=%s${RESET}\n" "$name" "$status"
+    fi
+}
+
+echo "ODoH targets:"
+probe_target "Cloudflare"   "odoh.cloudflare-dns.com"
+probe_target "crypto.sx"    "odoh.crypto.sx"
+probe_target "Snowstorm"    "dope.snowstorm.love"
+probe_target "Tiarap"       "doh.tiarap.org"
+
+echo
+echo "ODoH relays:"
+probe_relay  "Frank Denis (Fastly)" "https://odoh-relay.edgecompute.app/proxy"
+
+echo
+TOTAL=$((UP + DOWN))
+if [[ "$DOWN" -eq 0 ]]; then
+    printf "${GREEN}All %d endpoints up${RESET}\n" "$TOTAL"
+    exit 0
+else
+    printf "${YELLOW}%d/%d up, %d down${RESET}\n" "$UP" "$TOTAL" "$DOWN"
+    exit 1
+fi