Skip default port send in signal proto

client/internal/peer/conn.go

@@ -94,7 +94,8 @@ type PQHandshaker interface {
 	// peer-config time (the pull path). ok is false until one has been derived.
 	PSK(remoteKey string) (wgtypes.Key, bool)
 	// SetRemoteAddr registers the peer's data-path endpoint learned from signalling:
-	// its WG overlay IP with the advertised pq UDP port.
+	// its WG overlay IP with the announced pq UDP port (port 0 means the peer omitted
+	// it and is on the default port).
 	SetRemoteAddr(remoteKey string, addr netip.AddrPort)
 	// OnDataPathRekeyed signals a fresh WireGuard handshake for the peer; it clocks the
 	// next chained PSK rotation pushed over the data path. sinceActivity is how long

client/internal/peer/handshaker.go

@@ -182,9 +182,11 @@ func (h *Handshaker) Listen(ctx context.Context) {
 // pqRegisterEndpoint feeds the post-quantum handshaker the peer's data-path endpoint
 // (its WG overlay IP plus the advertised pq UDP port) learned from a remote offer/answer.
 func (h *Handshaker) pqRegisterEndpoint(remotePort int) {
-	if h.config.PQ == nil || remotePort <= 0 || remotePort > 65535 || len(h.config.WgConfig.AllowedIps) == 0 {
+	if h.config.PQ == nil || remotePort < 0 || remotePort > 65535 || len(h.config.WgConfig.AllowedIps) == 0 {
 		return
 	}
+	// remotePort may be 0 (the peer omitted it, meaning the default port); the adapter
+	// resolves 0 to DefaultPort.
 	addr := netip.AddrPortFrom(h.config.WgConfig.AllowedIps[0].Addr(), uint16(remotePort))
 	h.config.PQ.SetRemoteAddr(h.config.Key, addr)
 }