dnsx: impl GetRelay

It returns the sole backing Proxy of a DNS transport, if any.

Author: ignoramous

intra/backend/dnsx.go

@@ -89,6 +89,9 @@ type DNSTransport interface {
 	P50() int64
 	// Return the server host address used to initialize this transport.
 	GetAddr() *Gostr
+	// Return the proxy (relay) always used by this transport.
+	// Returns nil if there isn't any.
+	GetRelay() Proxy
 	// State of the transport after previous query (see: queryerror.go)
 	Status() int
 }
@@ -153,7 +156,8 @@ type ResolverListener interface {
 	// OnDNSRemoved is called when a DNS transport with id is removed, except
 	// when the transport is stopped, then OnDNSStopped is called instead.
 	OnDNSRemoved(id *Gostr)
-	// OnDNSStopped is called when the DNS transport is stopped. Note:
-	// OnDNSRemoved is not called for each transport before this.
+	// OnDNSStopped is called when all DNS transports are stopped. Note:
+	// OnDNSRemoved is not called for each transport even if they are
+	// being removed and not just stopped.
 	OnDNSStopped()
 }

intra/bootstrap.go

@@ -288,6 +288,10 @@ func (b *bootstrap) GetAddr() *x.Gostr {
 	return x.StrOf(dnsx.NoDNS)
 }
 
+func (b *bootstrap) GetRelay() x.Proxy {
+	return nil
+}
+
 func (b *bootstrap) IPPorts() []netip.AddrPort {
 	if tr := b.tr; tr != nil {
 		return tr.IPPorts()

intra/dns53/dot.go

@@ -367,6 +367,14 @@ func (t *dot) GetAddr() *x.Gostr {
 	return x.StrOf(t.getAddr())
 }
 
+func (t *dot) GetRelay() x.Proxy {
+	if r := t.relay; len(r) > 0 {
+		px, _ := t.proxies.ProxyFor(r)
+		return px
+	}
+	return nil
+}
+
 func (t *dot) getAddr() (addr string) {
 	if t.c3 != nil {
 		addr = dnsx.EchPrefix + t.addrport

intra/dns53/errorer.go

@@ -27,7 +27,7 @@ type errorer struct {
 
 var _ dnsx.Transport = (*errorer)(nil)
 
-// NewGroundedTransport returns a DNS transport that blocks all DNS queries.
+// NewErrorerTransport returns a DNS transport that always errors out on queries.
 func NewErrorerTransport(id string) *errorer {
 	t := &errorer{
 		id:     id, // typically, dnsx.Fixed
@@ -65,6 +65,10 @@ func (t *errorer) GetAddr() *x.Gostr {
 	return x.StrOf(t.ipport)
 }
 
+func (t *errorer) GetRelay() x.Proxy {
+	return nil
+}
+
 func (t *errorer) IPPorts() []netip.AddrPort {
 	return dnsx.NoIPPort
 }

intra/dns53/goos.go

@@ -197,6 +197,10 @@ func (t *goosr) getAddr() string {
 	return protect.Localhost + ":53" // dummy
 }
 
+func (t *goosr) GetRelay() x.Proxy {
+	return nil
+}
+
 func (t *goosr) IPPorts() []netip.AddrPort {
 	return []netip.AddrPort{netip.AddrPortFrom(netip.IPv6Loopback(), uint16(53))}
 }

intra/dns53/grounded.go

@@ -74,6 +74,10 @@ func (t *grounded) GetAddr() *x.Gostr {
 	return x.StrOf(t.ipport)
 }
 
+func (t *grounded) GetRelay() x.Proxy {
+	return nil
+}
+
 func (t *grounded) IPPorts() []netip.AddrPort {
 	return dnsx.NoIPPort
 }

intra/dns53/mdns.go

@@ -203,6 +203,10 @@ func (t *dnssd) GetAddr() *x.Gostr {
 	return x.StrOf(t.ipport)
 }
 
+func (t *dnssd) GetRelay() x.Proxy {
+	return nil
+}
+
 func (t *dnssd) IPPorts() []netip.AddrPort {
 	return []netip.AddrPort{
 		xdns.MDNSAddr4.AddrPort(),

intra/dns53/upstream.go

@@ -345,6 +345,14 @@ func (t *transport) getAddr() string {
 	return addr
 }
 
+func (t *transport) GetRelay() x.Proxy {
+	if r := t.relay; len(r) > 0 {
+		px, _ := t.proxies.ProxyFor(r)
+		return px
+	}
+	return nil
+}
+
 func (t *transport) IPPorts() (ipps []netip.AddrPort) {
 	for _, ip := range dialers.For(t.addrport) {
 		ipps = append(ipps, netip.AddrPortFrom(ip, t.port))

intra/dnscrypt/multiserver.go

@@ -310,8 +310,8 @@ func resolve(network string, data *dns.Msg, si *serverinfo, smm *x.DNSSummary) (
 	useudp := proto == dnsx.NetTypeUDP
 	pid := dnsx.NetNoProxy
 	if si != nil {
-		if r := si.relay; r != nil {
-			pid = si.chooseProxy([]string{r.ID().V()})
+		if r := si.relay; len(r) > 0 {
+			pid = si.chooseProxy([]string{r})
 		} else {
 			pid = si.chooseProxy(pids)
 		}
@@ -659,6 +659,10 @@ func (p *DcMulti) getAddr() string {
 	return p.lastAddr
 }
 
+func (p *DcMulti) GetRelay() x.Proxy {
+	return nil
+}
+
 func (p *DcMulti) IPPorts() []netip.AddrPort {
 	// TODO: get ipports from all servers
 	return dnsx.NoIPPort

intra/dnscrypt/servers.go

@@ -58,7 +58,7 @@ type serverinfo struct {
 	UDPAddr            *net.UDPAddr
 	TCPAddr            *net.TCPAddr
 	proxies            ipn.ProxyProvider // proxy-provider, may be nil
-	relay              ipn.Proxy         // proxy relay to use, may be nil
+	relay              string            // proxy relay to use, may be nil
 	est                core.P2QuantileEstimator
 
 	// fields below are mutable
@@ -260,7 +260,7 @@ func fetchDNSCryptServerInfo(proxy *DcMulti, name string, stamp stamps.ServerSta
 		RelayTCPAddrs:      core.NewZeroVolatile[[]*net.TCPAddr](), // populated later; see proxy.refreshRoutes()
 		RelayUDPAddrs:      core.NewZeroVolatile[[]*net.UDPAddr](), // populated later; see proxy.refreshRoutes()
 		proxies:            px,
-		relay:              relay,
+		relay:              relay.ID().V(),
 		est:                core.NewP50Estimator(ctx),
 		status:             core.NewVolatile(dnsx.Start),
 	}
@@ -393,6 +393,18 @@ func (s *serverinfo) getAddr() string {
 	return s.HostName
 }
 
+func (s *serverinfo) GetRelay() x.Proxy {
+	return s.getRelay()
+}
+
+func (s *serverinfo) getRelay() ipn.Proxy {
+	if r := s.relay; len(r) > 0 {
+		px, _ := s.proxies.ProxyFor(r)
+		return px
+	}
+	return nil
+}
+
 func (s *serverinfo) IPPorts() []netip.AddrPort {
 	if relay := s.RelayUDPAddrs.Load(); relay != nil {
 		return addr2ipp(relay...)
@@ -413,7 +425,7 @@ func (s *serverinfo) Stop() error {
 }
 
 func (s *serverinfo) dialudp(pid string, addr *net.UDPAddr) (net.Conn, error) {
-	userelay := s.relay != nil
+	userelay := s.GetRelay() != nil
 	useproxy := len(pid) != 0 // pid == dnsx.NetNoProxy => ipn.Base
 	if userelay || useproxy {
 		return s.dialpx(pid, "udp", addr.String())
@@ -422,7 +434,7 @@ func (s *serverinfo) dialudp(pid string, addr *net.UDPAddr) (net.Conn, error) {
 }
 
 func (s *serverinfo) dialtcp(pid string, addr *net.TCPAddr) (net.Conn, error) {
-	userelay := s.relay != nil
+	userelay := s.GetRelay() != nil
 	useproxy := len(pid) != 0 // pid == dnsx.NetNoProxy => ipn.Base
 	if userelay || useproxy {
 		return s.dialpx(pid, "tcp", addr.String())
@@ -431,7 +443,7 @@ func (s *serverinfo) dialtcp(pid string, addr *net.TCPAddr) (net.Conn, error) {
 }
 
 func (s *serverinfo) dialpx(pid, proto string, addr string) (net.Conn, error) {
-	relay := s.relay
+	relay := s.getRelay()
 	if relay != nil {
 		// addr is always ip:port; hence protect.dialers are not needed
 		return relay.Dialer().Dial(proto, addr)