Commit Graph

7 Commits

Author SHA1 Message Date
Razvan Dimescu
5b2cc874a1 feat: TCP fallback, query minimization, UDP auto-disable
Transport resilience for restrictive networks (ISPs blocking UDP:53):
- DNS-over-TCP fallback: UDP fail/truncation → automatic TCP retry
- UDP auto-disable: after 3 consecutive failures, switch to TCP-first
- IPv6 → TCP directly (UDP socket binds 0.0.0.0, can't reach IPv6)
- Network change resets UDP detection for re-probing
- Root hint rotation in TLD priming

Privacy:
- RFC 7816 query minimization: root servers see TLD only, not full name

Code quality:
- Merged find_starting_ns + find_starting_zone → find_closest_ns
- Extracted resolve_ns_addrs_from_glue shared helper
- Removed overall timeout wrapper (per-hop timeouts sufficient)
- forward_tcp for DNS-over-TCP (RFC 1035 §4.2.2)

Testing:
- Mock TCP-only DNS server for fallback tests (no network needed)
- tcp_fallback_resolves_when_udp_blocked
- tcp_only_iterative_resolution
- tcp_fallback_handles_nxdomain
- udp_auto_disable_resets
- Integration test suite (4 suites, 51 tests)
- Network probe script (tests/network-probe.sh)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-27 19:50:19 +02:00
Razvan Dimescu
637b374d8b feat: recursive resolution + full DNSSEC validation
Numa becomes a true DNS resolver — resolves from root nameservers
with complete DNSSEC chain-of-trust verification.

Recursive resolution:
- Iterative RFC 1034 from configurable root hints (13 default)
- CNAME chasing (depth 8), referral following (depth 10)
- A+AAAA glue extraction, IPv6 nameserver support
- TLD priming: NS + DS + DNSKEY for 34 gTLDs + EU ccTLDs
- Config: mode = "recursive" in [upstream], root_hints, prime_tlds

DNSSEC (all 4 phases):
- EDNS0 OPT pseudo-record (DO bit, 1232 payload per DNS Flag Day 2020)
- DNSKEY, DS, RRSIG, NSEC, NSEC3 record types with wire read/write
- Signature verification via ring: RSA/SHA-256, ECDSA P-256, Ed25519
- Chain-of-trust: zone DNSKEY → parent DS → root KSK (key tag 20326)
- DNSKEY RRset self-signature verification (RRSIG(DNSKEY) by KSK)
- RRSIG expiration/inception time validation
- NSEC: NXDOMAIN gap proofs, NODATA type absence, wildcard denial
- NSEC3: SHA-1 iterated hashing, closest encloser proof, hash range
- Authority RRSIG verification for denial proofs
- Config: [dnssec] enabled/strict (default false, opt-in)
- AD bit on Secure, SERVFAIL on Bogus+strict
- DnssecStatus cached per entry, ValidationStats logging

Performance:
- TLD chain pre-warmed on startup (root DNSKEY + TLD DS/DNSKEY)
- Referral DS piggybacking from authority sections
- DNSKEY prefetch before validation loop
- Cold-cache validation: ~1 DNSKEY fetch (down from 5)
- Benchmarks: RSA 10.9µs, ECDSA 174ns, DS verify 257ns

Also:
- write_qname fix for root domain "." (was producing malformed queries)
- write_record_header() dedup, write_bytes() bulk writes
- DnsRecord::domain() + query_type() accessors
- UpstreamMode enum, DEFAULT_EDNS_PAYLOAD const
- Real glue TTL (was hardcoded 3600)
- DNSSEC restricted to recursive mode only

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-27 18:39:23 +02:00
Razvan Dimescu
d274500308 feat: DNS-over-HTTPS (DoH) upstream forwarding (#14)
* feat: DNS-over-HTTPS upstream forwarding

Encrypt upstream queries via DoH — ISPs see HTTPS traffic on port 443,
not plaintext DNS on port 53. URL scheme determines transport:
https:// = DoH, bare IP = plain UDP. Falls back to Quad9 DoH when
system resolver cannot be detected.

- Upstream enum (Udp/Doh) with Display and PartialEq
- BytePacketBuffer::from_bytes constructor
- reqwest http2 feature for DoH server compatibility
- network_watch_loop guards against DoH→UDP silent downgrade
- 5 new tests (mock DoH server, HTTP errors, timeout)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* style: cargo fmt

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* docs: add DoH to README — Why Numa, comparison table, roadmap

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-24 00:39:58 +02:00
Razvan Dimescu
7a64e7c4aa fix truncation check: use == instead of >= for buffer-full detection
recv_from can never return more bytes than the buffer size — the kernel
truncates silently. == is the correct heuristic for detecting truncation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-21 03:35:21 +02:00
Razvan Dimescu
2cb87bbe83 fix rustfmt formatting
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-21 03:31:44 +02:00
Razvan Dimescu
4b60a4b49c launch hardening: TC bit, Dockerfile, platform-aware deploy
- Set TC (truncation) bit when response exceeds 4096-byte buffer
  instead of dropping the response silently. Clients can retry via TCP.
- Log when upstream response is truncated in forward.rs.
- Dockerfile: bump to Rust 1.88, include site/service files, use
  alpine runtime instead of scratch, add cmake/perl for aws-lc-sys.
- Makefile deploy: platform-aware — codesign on macOS, systemctl on Linux.
- README: trim roadmap to near-term items only.
- Verified: Docker build + smoke test passes on Linux (Alpine musl).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-21 03:31:15 +02:00
Razvan Dimescu
9c71e9bb3f refactor to async tokio with modular architecture
- Replace synchronous std::net::UdpSocket with tokio async runtime
- Spawn concurrent task per incoming DNS query via tokio::spawn
- Extract monolithic main.rs into modules: buffer, header, question,
  record, packet, config, cache, forward, stats
- Share state across tasks via Arc<ServerCtx> with scoped Mutex locks
- Add TOML config loading, TTL-aware cache, structured logging, stats
- Add CLAUDE.md, README, dns_fun.toml config, and design docs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-10 04:50:16 +02:00