address PR review: SRV port, drop spike, percent-encoded paths

- SRV record uses first service's port (was 0, confused dns-sd -L)
- Remove examples/mdns_coexist.rs (served its purpose as spike)
- Reject percent-encoding in route paths (defense-in-depth)

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

examples/mdns_coexist.rs

@@ -1,211 +0,0 @@
-use socket2::{Domain, Protocol, Socket, Type};
-/// Spike: can we bind to mDNS multicast (224.0.0.251:5353) alongside macOS mDNSResponder?
-///
-/// Tests:
-/// 1. Bind UDP socket to 0.0.0.0:5353 with SO_REUSEPORT + SO_REUSEADDR
-/// 2. Join multicast group 224.0.0.251
-/// 3. Send a PTR query for _services._dns-sd._udp.local (standard browse)
-/// 4. Listen for mDNS responses — do we see them alongside mDNSResponder?
-/// 5. Send a _numa._tcp.local announcement — does it conflict?
-///
-/// Run: cargo run --example mdns_coexist
-use std::mem::MaybeUninit;
-use std::net::{Ipv4Addr, SocketAddrV4};
-
-const MDNS_ADDR: Ipv4Addr = Ipv4Addr::new(224, 0, 0, 251);
-const MDNS_PORT: u16 = 5353;
-
-fn main() -> std::io::Result<()> {
-    println!("=== mDNS coexistence spike ===\n");
-
-    // Step 1: Create UDP socket with SO_REUSEPORT + SO_REUSEADDR
-    let socket = Socket::new(Domain::IPV4, Type::DGRAM, Some(Protocol::UDP))?;
-    socket.set_reuse_address(true)?;
-    #[cfg(unix)]
-    socket.set_reuse_port(true)?;
-    println!("[OK] Socket created with SO_REUSEADDR + SO_REUSEPORT");
-
-    // Step 2: Bind to 0.0.0.0:5353
-    let bind_addr = SocketAddrV4::new(Ipv4Addr::UNSPECIFIED, MDNS_PORT);
-    match socket.bind(&bind_addr.into()) {
-        Ok(()) => println!("[OK] Bound to 0.0.0.0:{}", MDNS_PORT),
-        Err(e) => {
-            println!("[FAIL] Cannot bind to port {}: {}", MDNS_PORT, e);
-            println!("       mDNSResponder may not allow port sharing");
-            return Ok(());
-        }
-    }
-
-    // Step 3: Join multicast group
-    match socket.join_multicast_v4(&MDNS_ADDR, &Ipv4Addr::UNSPECIFIED) {
-        Ok(()) => println!("[OK] Joined multicast group {}", MDNS_ADDR),
-        Err(e) => {
-            println!("[FAIL] Cannot join multicast {}: {}", MDNS_ADDR, e);
-            return Ok(());
-        }
-    }
-
-    // Step 4: Send a PTR query for _services._dns-sd._udp.local
-    let query = build_mdns_query("_services._dns-sd._udp.local");
-    let dest = SocketAddrV4::new(MDNS_ADDR, MDNS_PORT);
-    match socket.send_to(&query, &dest.into()) {
-        Ok(n) => println!("[OK] Sent mDNS browse query ({} bytes)", n),
-        Err(e) => {
-            println!("[FAIL] Cannot send to multicast: {}", e);
-            return Ok(());
-        }
-    }
-
-    // Step 5: Listen for responses (3 second timeout)
-    socket.set_read_timeout(Some(std::time::Duration::from_secs(3)))?;
-    let mut buf = [MaybeUninit::<u8>::zeroed(); 4096];
-    let mut count = 0;
-
-    println!("\nListening for mDNS responses (3s timeout)...\n");
-    loop {
-        match socket.recv_from(&mut buf) {
-            Ok((n, addr)) => {
-                let data: &[u8] =
-                    unsafe { &*(&buf[..n] as *const [MaybeUninit<u8>] as *const [u8]) };
-                count += 1;
-                let flags = u16::from_be_bytes([data[2], data[3]]);
-                let is_response = flags & 0x8000 != 0;
-                let qdcount = u16::from_be_bytes([data[4], data[5]]);
-                let ancount = u16::from_be_bytes([data[6], data[7]]);
-                println!(
-                    "  #{} from {} — {} bytes, {}, questions={}, answers={}",
-                    count,
-                    addr.as_socket().map(|s| s.to_string()).unwrap_or_default(),
-                    n,
-                    if is_response { "RESPONSE" } else { "QUERY" },
-                    qdcount,
-                    ancount,
-                );
-                if count >= 20 {
-                    println!("\n  (capped at 20, stopping)");
-                    break;
-                }
-            }
-            Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
-                println!("\n  Timeout — received {} packets total", count);
-                break;
-            }
-            Err(e) => {
-                println!("[FAIL] recv error: {}", e);
-                break;
-            }
-        }
-    }
-
-    // Step 6: Send a _numa._tcp.local announcement
-    let announcement =
-        build_mdns_announcement("_numa._tcp.local", "test-numa._numa._tcp.local", 5380);
-    match socket.send_to(&announcement, &dest.into()) {
-        Ok(n) => println!("\n[OK] Sent _numa._tcp.local announcement ({} bytes)", n),
-        Err(e) => println!("\n[FAIL] Cannot send announcement: {}", e),
-    }
-
-    // Verify we can see our own announcement
-    socket.set_read_timeout(Some(std::time::Duration::from_secs(2)))?;
-    let mut buf2 = [MaybeUninit::<u8>::zeroed(); 4096];
-    println!("Listening for our announcement echo (2s)...\n");
-    loop {
-        match socket.recv_from(&mut buf2) {
-            Ok((n, addr)) => {
-                let data: &[u8] =
-                    unsafe { &*(&buf2[..n] as *const [MaybeUninit<u8>] as *const [u8]) };
-                let flags = u16::from_be_bytes([data[2], data[3]]);
-                let is_response = flags & 0x8000 != 0;
-                if is_response {
-                    println!(
-                        "  Received response from {} ({} bytes) — multicast RX confirmed",
-                        addr.as_socket().map(|s| s.to_string()).unwrap_or_default(),
-                        n
-                    );
-                }
-            }
-            Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
-                println!("  Timeout");
-                break;
-            }
-            Err(_) => break,
-        }
-    }
-
-    // Verdict
-    println!("\n=== Verdict ===");
-    if count > 0 {
-        println!(
-            "[PASS] mDNS coexistence works — received {} packets alongside mDNSResponder",
-            count
-        );
-        println!("       Safe to proceed with mDNS-based LAN discovery");
-    } else {
-        println!("[WARN] No mDNS packets received — may need further investigation");
-        println!("       Possible causes: firewall, mDNSResponder not sharing port");
-    }
-
-    Ok(())
-}
-
-/// Build a minimal mDNS PTR query packet
-fn build_mdns_query(name: &str) -> Vec<u8> {
-    let mut pkt = Vec::new();
-
-    // Header: ID=0, flags=0 (query), QDCOUNT=1
-    pkt.extend_from_slice(&[0, 0]); // ID
-    pkt.extend_from_slice(&[0, 0]); // Flags (standard query)
-    pkt.extend_from_slice(&[0, 1]); // QDCOUNT = 1
-    pkt.extend_from_slice(&[0, 0]); // ANCOUNT
-    pkt.extend_from_slice(&[0, 0]); // NSCOUNT
-    pkt.extend_from_slice(&[0, 0]); // ARCOUNT
-
-    // Question: encode name as labels
-    for label in name.split('.') {
-        pkt.push(label.len() as u8);
-        pkt.extend_from_slice(label.as_bytes());
-    }
-    pkt.push(0); // root label
-
-    pkt.extend_from_slice(&[0, 12]); // QTYPE = PTR (12)
-    pkt.extend_from_slice(&[0, 1]); // QCLASS = IN (1)
-
-    pkt
-}
-
-/// Build a minimal mDNS announcement (response with PTR + SRV + TXT)
-fn build_mdns_announcement(service_type: &str, instance_name: &str, port: u16) -> Vec<u8> {
-    let mut pkt = Vec::new();
-
-    // Header: ID=0, flags=0x8400 (response, authoritative), ANCOUNT=1
-    pkt.extend_from_slice(&[0, 0]); // ID
-    pkt.extend_from_slice(&[0x84, 0x00]); // Flags: QR=1, AA=1
-    pkt.extend_from_slice(&[0, 0]); // QDCOUNT
-    pkt.extend_from_slice(&[0, 1]); // ANCOUNT = 1 (just PTR for now)
-    pkt.extend_from_slice(&[0, 0]); // NSCOUNT
-    pkt.extend_from_slice(&[0, 0]); // ARCOUNT
-
-    // PTR record: _numa._tcp.local → test-numa._numa._tcp.local
-    encode_name(&mut pkt, service_type);
-    pkt.extend_from_slice(&[0, 12]); // TYPE = PTR
-    pkt.extend_from_slice(&[0, 1]); // CLASS = IN
-    pkt.extend_from_slice(&[0, 0, 0, 120]); // TTL = 120s
-
-    // RDATA: the instance name
-    let mut rdata = Vec::new();
-    encode_name(&mut rdata, instance_name);
-    pkt.extend_from_slice(&(rdata.len() as u16).to_be_bytes()); // RDLENGTH
-    pkt.extend_from_slice(&rdata);
-
-    let _ = port; // SRV record would use this — omitted for spike simplicity
-
-    pkt
-}
-
-fn encode_name(buf: &mut Vec<u8>, name: &str) {
-    for label in name.split('.') {
-        buf.push(label.len() as u8);
-        buf.extend_from_slice(label.as_bytes());
-    }
-    buf.push(0);
-}

src/api.rs

@@ -777,8 +777,11 @@ async fn add_route(
     if req.path.is_empty() || !req.path.starts_with('/') {
         return Err((StatusCode::BAD_REQUEST, "path must start with /".into()));
     }
-    if req.path.contains("/../") || req.path.ends_with("/..") {
+    if req.path.contains("/../") || req.path.ends_with("/..") || req.path.contains("%") {
-        return Err((StatusCode::BAD_REQUEST, "path must not contain '..'".into()));
+        return Err((
+            StatusCode::BAD_REQUEST,
+            "path must not contain '..' or percent-encoding".into(),
+        ));
     }
     if req.port == 0 {
         return Err((StatusCode::BAD_REQUEST, "port must be > 0".into()));

src/lan.rs

@@ -256,7 +256,7 @@ fn build_announcement(
     let rdata_start = buf.pos();
     buf.write_u16(0)?; // priority
     buf.write_u16(0)?; // weight
-    buf.write_u16(0)?; // port (services have individual ports in TXT)
+    buf.write_u16(services.first().map(|(_, p)| *p).unwrap_or(0))?; // first service port for SRV display
     buf.write_qname(&host_local)?;
     patch_rdlen(&mut buf, rdlen_pos, rdata_start)?;