wip: working - moving on to single relay w/ address discovery

node/globals.go

@@ -23,6 +23,8 @@ type peerRoute struct {
 	ControlCipher *controlCipher
 	DataCipher    *dataCipher
 	RemoteAddr    netip.AddrPort // Remote address if directly connected.
+	// TODO: Remove this and use global localAddr and relayIP.
+	// Replace w/ a Direct boolean.
 	LocalAddr netip.AddrPort // Local address as seen by the remote.
 	RelayIP   byte           // Non-zero if we should relay.
 }
@@ -32,6 +34,7 @@ var (
 	netName    string
 	localIP    byte
 	localPub   bool
+	localAddr  netip.AddrPort
 	privateKey []byte
 
 	// Shared interface for writing.
@@ -54,4 +57,9 @@ var (
 
 	// Global routing table.
 	routingTable [256]*atomic.Pointer[peerRoute]
+
+	// TODO: use relay for local address discovery. This should be new stream ID,
+	// managed by a single thread.
+	// localAddr *atomic.Pointer[netip.AddrPort]
+	// relayIP *atomic.Pointer[byte]
 )

node/hubpoller.go

@@ -58,7 +58,6 @@ func (hp *hubPoller) Run() {
 func (hp *hubPoller) pollHub() {
 	var state m.NetworkState
 
-	log.Printf("Fetching peer state...")
 	resp, err := hp.client.Do(hp.req)
 	if err != nil {
 		log.Printf("Failed to fetch peer state: %v", err)

node/main.go

@@ -105,7 +105,13 @@ func main(listenIP string, port uint16) {
 
 	// Intialize globals.
 	localIP = config.PeerIP
-	localPub = addrIsValid(config.PublicIP)
+
+	ip, ok := netip.AddrFromSlice(config.PublicIP)
+	if ok {
+		localPub = true
+		localAddr = netip.AddrPortFrom(ip, config.Port)
+	}
+
 	privateKey = config.PrivKey
 
 	_iface = newIFWriter(iface)
@@ -178,6 +184,8 @@ func readFromConn(conn *net.UDPConn) {
 		case controlStreamID:
 			handleControlPacket(remoteAddr, h, data, decBuf)
 
+			// TODO: discoveryStreamID
+
 		case dataStreamID:
 			handleDataPacket(h, data, decBuf)
 
@@ -217,7 +225,7 @@ func handleControlPacket(addr netip.AddrPort, h header, data, decBuf []byte) {
 
 	pkt := controlPacket{
 		SrcIP:   h.SourceIP,
-		RemoteAddr: addr,
+		SrcAddr: addr,
 	}
 
 	if err := pkt.ParsePayload(out); err != nil {

node/packets.go

@@ -2,6 +2,7 @@ package node
 
 import (
 	"errors"
+	"log"
 	"net/netip"
 )
 
@@ -14,13 +15,14 @@ const (
 	packetTypeSyn = iota + 1
 	packetTypeSynAck
 	packetTypeAck
+	packetTypeProbe
 )
 
 // ----------------------------------------------------------------------------
 
 type controlPacket struct {
 	SrcIP   byte
-	RemoteAddr netip.AddrPort
+	SrcAddr netip.AddrPort
 	Payload any
 }
 
@@ -30,8 +32,9 @@ func (p *controlPacket) ParsePayload(buf []byte) (err error) {
 		p.Payload, err = parseSynPacket(buf)
 	case packetTypeSynAck:
 		p.Payload, err = parseSynAckPacket(buf)
-	case packetTypeAck:
+	case packetTypeProbe:
-		p.Payload, err = parseAckPacket(buf)
+		log.Printf("Got probe...")
+		p.Payload, err = parseProbePacket(buf)
 	default:
 		return errUnknownPacketType
 	}
@@ -44,6 +47,7 @@ type synPacket struct {
 	TraceID   uint64   // TraceID to match response w/ request.
 	SharedKey [32]byte // Our shared key.
 	RelayIP   byte
+	FromAddr  netip.AddrPort // The client's sending address.
 }
 
 func (p synPacket) Marshal(buf []byte) []byte {
@@ -52,6 +56,7 @@ func (p synPacket) Marshal(buf []byte) []byte {
 		Uint64(p.TraceID).
 		SharedKey(p.SharedKey).
 		Byte(p.RelayIP).
+		AddrPort(p.FromAddr).
 		Build()
 }
 
@@ -60,6 +65,7 @@ func parseSynPacket(buf []byte) (p synPacket, err error) {
 		Uint64(&p.TraceID).
 		SharedKey(&p.SharedKey).
 		Byte(&p.RelayIP).
+		AddrPort(&p.FromAddr).
 		Error()
 	return
 }
@@ -68,47 +74,54 @@ func parseSynPacket(buf []byte) (p synPacket, err error) {
 
 type synAckPacket struct {
 	TraceID  uint64
-	RecvAddr netip.AddrPort
+	FromAddr netip.AddrPort
+	ToAddr   netip.AddrPort
 }
 
 func (p synAckPacket) Marshal(buf []byte) []byte {
 	return newBinWriter(buf).
 		Byte(packetTypeSynAck).
 		Uint64(p.TraceID).
-		AddrPort(p.RecvAddr).
+		AddrPort(p.FromAddr).
+		AddrPort(p.ToAddr).
 		Build()
 }
 
 func parseSynAckPacket(buf []byte) (p synAckPacket, err error) {
 	err = newBinReader(buf[1:]).
 		Uint64(&p.TraceID).
-		AddrPort(&p.RecvAddr).
+		AddrPort(&p.FromAddr).
+		AddrPort(&p.ToAddr).
 		Error()
 	return
 }
 
 // ----------------------------------------------------------------------------
 
-type ackPacket struct {
+type addrDiscoveryPacket struct {
 	TraceID  uint64
-	SendAddr netip.AddrPort // Address of the sender.
+	FromAddr netip.AddrPort
-	RecvAddr netip.AddrPort // Address of the recipient as seen by sender.
+	ToAddr   netip.AddrPort
 }
 
-func (p ackPacket) Marshal(buf []byte) []byte {
+// ----------------------------------------------------------------------------
+
+// A probeReqPacket is sent from a client to a server to determine if direct
+// UDP communication can be used.
+type probePacket struct {
+	TraceID uint64
+}
+
+func (p probePacket) Marshal(buf []byte) []byte {
 	return newBinWriter(buf).
-		Byte(packetTypeAck).
+		Byte(packetTypeProbe).
 		Uint64(p.TraceID).
-		AddrPort(p.SendAddr).
-		AddrPort(p.RecvAddr).
 		Build()
 }
 
-func parseAckPacket(buf []byte) (p ackPacket, err error) {
+func parseProbePacket(buf []byte) (p probePacket, err error) {
 	err = newBinReader(buf[1:]).
 		Uint64(&p.TraceID).
-		AddrPort(&p.SendAddr).
-		AddrPort(&p.RecvAddr).
 		Error()
 	return
 }

node/peer-supervisor.go

@@ -66,6 +66,36 @@ func (s *peerSupervisor) sendControlPacket(pkt interface{ Marshal([]byte) []byte
 	_sendControlPacket(pkt, s.staged, s.buf1, s.buf2)
 }
 
+func (s *peerSupervisor) sendControlPacketTo(
+	pkt interface{ Marshal([]byte) []byte },
+	addr netip.AddrPort,
+) {
+	if !addr.IsValid() {
+		s.logf("ERROR: Attepted to send packet to invalid address: %v", addr)
+		return
+	}
+	route := s.staged
+	route.RelayIP = 0
+	route.RemoteAddr = addr
+	_sendControlPacket(pkt, route, s.buf1, s.buf2)
+}
+
+// ----------------------------------------------------------------------------
+
+func (s *peerSupervisor) getLocalAddr() netip.AddrPort {
+	if localPub {
+		return localAddr
+	}
+
+	if s.staged.RelayIP != 0 {
+		if addr := routingTable[s.staged.RelayIP].Load().LocalAddr; addr.IsValid() {
+			return addr
+		}
+	}
+
+	return s.staged.LocalAddr
+}
+
 // ----------------------------------------------------------------------------
 
 func (s *peerSupervisor) logf(msg string, args ...any) {
@@ -113,7 +143,7 @@ func (s *peerSupervisor) _peerUpdate(peer *m.Peer) stateFunc {
 
 	if s.remotePub == localPub {
 		if localIP < s.remoteIP {
-			return s.serverAccept
+			return s.server
 		}
 		return s.clientInit
 	}
@@ -121,18 +151,13 @@ func (s *peerSupervisor) _peerUpdate(peer *m.Peer) stateFunc {
 	if s.remotePub {
 		return s.clientInit
 	}
-	return s.serverAccept
+	return s.server
 }
 
 // ----------------------------------------------------------------------------
 
-func (s *peerSupervisor) serverAccept() stateFunc {
+func (s *peerSupervisor) server() stateFunc {
-	s.logf("STATE: server-accept")
+	s.logf("STATE: server")
-	s.staged.Up = false
-	s.staged.DataCipher = nil
-	s.staged.RemoteAddr = zeroAddrPort
-	s.staged.RelayIP = 0
-	s.publish()
 
 	var syn synPacket
 
@@ -145,61 +170,38 @@ func (s *peerSupervisor) serverAccept() stateFunc {
 			switch p := pkt.Payload.(type) {
 
 			case synPacket:
+				// Before we can respond to this packet, we need to make sure the
+				// route is setup properly.
+				if p.TraceID != syn.TraceID {
 					syn = p
-				s.staged.RemoteAddr = pkt.RemoteAddr
+					s.staged.Up = true
+					s.staged.RemoteAddr = pkt.SrcAddr
 					s.staged.DataCipher = newDataCipherFromKey(syn.SharedKey)
 					s.staged.RelayIP = syn.RelayIP
+					s.staged.LocalAddr = s.getLocalAddr()
 					s.publish()
-				s.sendControlPacket(synAckPacket{TraceID: syn.TraceID, RecvAddr: pkt.RemoteAddr})
-
-			case ackPacket:
-				if p.TraceID != syn.TraceID {
-					continue
 				}
 
-				// Publish.
+				// We should always respond.
-				return s.serverConnected(syn.TraceID)
+				s.sendControlPacket(synAckPacket{
-			}
+					TraceID:  syn.TraceID,
-		}
+					FromAddr: s.staged.LocalAddr,
-	}
+					ToAddr:   pkt.SrcAddr,
+				})
+
+				// If we're relayed, attempt to probe the client.
+				if s.staged.RelayIP != 0 && syn.FromAddr.IsValid() {
+					probe := probePacket{TraceID: newTraceID()}
+					s.logf("SERVER sending probe %v: %v", probe, syn.FromAddr)
+					s.sendControlPacketTo(probe, syn.FromAddr)
 				}
 
-// ----------------------------------------------------------------------------
+			case probePacket:
-
+				s.logf("SERVER got probe: %v", p)
-func (s *peerSupervisor) serverConnected(traceID uint64) stateFunc {
+				s.logf("SERVER sending probe: %v", pkt.SrcAddr)
-	s.logf("STATE: server-connected")
+				s.sendControlPacketTo(probePacket{TraceID: p.TraceID}, pkt.SrcAddr)
-	s.staged.Up = true
-	s.publish()
-	return func() stateFunc {
-		return s._serverConnected(traceID)
 			}
 		}
-
-func (s *peerSupervisor) _serverConnected(traceID uint64) stateFunc {
-
-	timeoutTimer := time.NewTimer(timeoutInterval)
-	defer timeoutTimer.Stop()
-
-	for {
-		select {
-		case peer := <-s.peerUpdates:
-			return s.peerUpdate(peer)
-
-		case pkt := <-s.controlPackets:
-			switch p := pkt.Payload.(type) {
-
-			case ackPacket:
-				if p.TraceID != traceID {
-					return s.serverAccept
-				}
-				s.sendControlPacket(ackPacket{TraceID: traceID, RecvAddr: pkt.RemoteAddr})
-				timeoutTimer.Reset(timeoutInterval)
-			}
-
-		case <-timeoutTimer.C:
-			s.logf("server timeout")
-			return s.serverAccept
-		}
 	}
 }
 
@@ -208,13 +210,10 @@ func (s *peerSupervisor) _serverConnected(traceID uint64) stateFunc {
 func (s *peerSupervisor) clientInit() stateFunc {
 	s.logf("STATE: client-init")
 	if !s.remotePub {
-		// TODO: Check local discovery for IP.
-		// TODO: Attempt UDP hole punch.
-		// TODO: client-relayed
 		return s.clientSelectRelay
 	}
 
-	return s.clientDial
+	return s.client
 }
 
 // ----------------------------------------------------------------------------
@@ -237,7 +236,7 @@ func (s *peerSupervisor) clientSelectRelay() stateFunc {
 				s.staged.RelayIP = relay.IP
 				s.staged.LocalAddr = relay.LocalAddr
 				s.publish()
-				return s.clientDial
+				return s.client
 			}
 
 			s.logf("No relay available.")
@@ -264,20 +263,26 @@ func (s *peerSupervisor) selectRelay() *peerRoute {
 
 // ----------------------------------------------------------------------------
 
-func (s *peerSupervisor) clientDial() stateFunc {
+func (s *peerSupervisor) client() stateFunc {
-	s.logf("STATE: client-dial")
+	s.logf("STATE: client")
 
 	var (
 		syn = synPacket{
 			TraceID:   newTraceID(),
 			SharedKey: s.staged.DataCipher.Key(),
 			RelayIP:   s.staged.RelayIP,
+			FromAddr:  s.getLocalAddr(),
 		}
+		ack synAckPacket
 
-		timeout = time.NewTimer(dialTimeout)
+		probe = probePacket{TraceID: newTraceID()}
+
+		timeoutTimer = time.NewTimer(timeoutInterval)
+		pingTimer    = time.NewTimer(pingInterval)
 	)
 
-	defer timeout.Stop()
+	defer timeoutTimer.Stop()
+	defer pingTimer.Stop()
 
 	s.sendControlPacket(syn)
 
@@ -289,64 +294,36 @@ func (s *peerSupervisor) clientDial() stateFunc {
 
 		case pkt := <-s.controlPackets:
 			switch p := pkt.Payload.(type) {
+
 			case synAckPacket:
 				if p.TraceID != syn.TraceID {
+					s.logf("Bad traceID?")
 					continue // Hmm...
 				}
-				s.sendControlPacket(ackPacket{TraceID: syn.TraceID, RecvAddr: pkt.RemoteAddr})
+				ack = p
-				return s.clientConnected(p)
-			}
-
-		case <-timeout.C:
-			return s.clientInit
-		}
-	}
-}
-
-// ----------------------------------------------------------------------------
-
-func (s *peerSupervisor) clientConnected(p synAckPacket) stateFunc {
-	s.logf("STATE: client-connected")
-	s.staged.Up = true
-	s.staged.LocalAddr = p.RecvAddr
-	s.publish()
-
-	return func() stateFunc {
-		return s._clientConnected(p.TraceID)
-	}
-}
-
-func (s *peerSupervisor) _clientConnected(traceID uint64) stateFunc {
-
-	pingTimer := time.NewTimer(pingInterval)
-	timeoutTimer := time.NewTimer(timeoutInterval)
-
-	defer pingTimer.Stop()
-	defer timeoutTimer.Stop()
-
-	for {
-		select {
-		case peer := <-s.peerUpdates:
-			return s.peerUpdate(peer)
-
-		case pkt := <-s.controlPackets:
-			switch p := pkt.Payload.(type) {
-
-			case ackPacket:
-				if p.TraceID != traceID {
-					return s.clientInit
-				}
 				timeoutTimer.Reset(timeoutInterval)
+
+				if !s.staged.Up {
+					s.staged.Up = true
+					s.staged.LocalAddr = p.ToAddr
+					s.publish()
+				}
+
+			case probePacket:
+				s.logf("CLIENT got probe: %v", p)
 			}
 
 		case <-pingTimer.C:
-			s.sendControlPacket(ackPacket{TraceID: traceID})
+			s.sendControlPacket(syn)
 			pingTimer.Reset(pingInterval)
 
-		case <-timeoutTimer.C:
+			if s.staged.RelayIP != 0 && ack.FromAddr.IsValid() {
-			s.logf("client timeout")
+				s.logf("CLIENT sending probe %v: %v", probe, ack.FromAddr)
-			return s.clientInit
+				s.sendControlPacketTo(probe, ack.FromAddr)
+			}
 
+		case <-timeoutTimer.C:
+			return s.clientInit
 		}
 	}
 }