WIP: Apparently working?

README.md

@@ -2,12 +2,13 @@
 
 ## TO DO
 
-* Double buffering in IFReader and ConnReader ?
 * Replace time-based counter with startup counter
   * 16 byte startupCounter
   * (startupCount << 48) + counter
   * pass startup count to newRoutingTable function (or global?)
   * write / increment on startup
+* Use startup counter for trace IDs as well.
+* Double buffering in IFReader and ConnReader ?
 * Clean up state machine - one class w/
   * type stateFunc func(msg any) stateFunc
   * "init" funcs: func enterDisconnected() stateFunc

peer/connreader.go

@@ -42,16 +42,7 @@ func (r *ConnReader) handleNextPacket() {
 	buf = buf[:n]
 	h := parseHeader(buf)
 
-	remote := r.RemotePeers[h.SourceIP].Load()
-
-	switch h.StreamID {
-	case controlStreamID:
-		remote.handleControlPacket(h, remoteAddr, buf)
-	case dataStreamID:
-		remote.handleDataPacket(h, buf)
-	default:
-		r.logf("Unknown stream ID: %d", h.StreamID)
-	}
+	r.RemotePeers[h.SourceIP].Load().HandlePacket(h, remoteAddr, buf)
 }
 
 func (r *ConnReader) logf(format string, args ...any) {

peer/globals.go

@@ -60,6 +60,8 @@ type Globals struct {
 
 	// Global TUN interface.
 	IFace io.ReadWriteCloser
+
+	// For trace ID.
 }
 
 func NewGlobals(

peer/mcreader.go

@@ -41,7 +41,6 @@ func runMCReaderInner(g Globals) {
 			logf("Failed to open discovery packet?")
 			continue
 		}
-		log.Printf("Got local discovery from %v: %v", remoteAddr, h)
 
 		g.RemotePeers[h.SourceIP].Load().HandleLocalDiscoveryPacket(h, remoteAddr, buf)
 	}

peer/packets-util.go

@@ -7,6 +7,7 @@ import (
 	"unsafe"
 )
 
+// TODO: Initialize w/ startup counter.
 var traceIDCounter uint64 = uint64(time.Now().Unix()<<30) + 1
 
 func newTraceID() uint64 {

peer/remote.go

@@ -98,12 +98,12 @@ func (r *Remote) sendUDP(b []byte, addr netip.AddrPort) {
 
 // ----------------------------------------------------------------------------
 
-func (r *Remote) encryptData(conf remoteConfig, packet []byte) []byte {
+func (r *Remote) encryptData(conf remoteConfig, destIP byte, packet []byte) []byte {
 	h := Header{
 		StreamID: dataStreamID,
 		Counter:  atomic.AddUint64(&r.sendCounter, 1),
 		SourceIP: r.Globals.LocalPeerIP,
-		DestIP:   r.RemotePeerIP,
+		DestIP:   destIP,
 	}
 	return conf.DataCipher.Encrypt(h, packet, packet[len(packet):cap(packet)])
 }
@@ -144,22 +144,21 @@ func (r *Remote) sendDataRelayed(conf remoteConfig, data []byte) {
 		return
 	}
 
-	relay.relayData(r.encryptData(conf, data))
+	relay.relayData(conf.Peer.PeerIP, r.encryptData(conf, conf.Peer.PeerIP, data))
 }
 
 // sendDataDirect sends data to the remote directly.
 func (r *Remote) sendDataDirect(conf remoteConfig, data []byte) {
-	r.logf("Sending data direct...")
-	r.sendUDP(r.encryptData(conf, data), conf.DirectAddr)
+	r.sendUDP(r.encryptData(conf, conf.Peer.PeerIP, data), conf.DirectAddr)
 }
 
-func (r *Remote) relayData(enc []byte) {
+func (r *Remote) relayData(toIP byte, enc []byte) {
 	conf := r.conf()
 	if !conf.Up || !conf.Direct {
 		r.logf("Cannot relay: not up or not a direct connection")
 		return
 	}
-	r.sendDataDirect(conf, enc)
+	r.sendUDP(r.encryptData(conf, toIP, enc), conf.DirectAddr)
 }
 
 func (r *Remote) sendControl(conf remoteConfig, data []byte) {
@@ -176,13 +175,11 @@ func (r *Remote) sendControlToAddr(buf []byte, addr netip.AddrPort) {
 }
 
 func (r *Remote) sendControlDirect(conf remoteConfig, data []byte) {
-	r.logf("Sending control direct...")
 	enc := r.encryptControl(conf, data)
 	r.sendUDP(enc, conf.DirectAddr)
 }
 
 func (r *Remote) sendControlRelayed(conf remoteConfig, data []byte) {
-	r.logf("Sending control relayed...")
 	relay := r.RelayHandler.Load()
 
 	if relay == nil {
@@ -190,7 +187,7 @@ func (r *Remote) sendControlRelayed(conf remoteConfig, data []byte) {
 		return
 	}
 
-	relay.relayData(r.encryptControl(conf, data))
+	relay.relayData(conf.Peer.PeerIP, r.encryptControl(conf, data))
 }
 
 func (r *Remote) forwardPacket(data []byte) {
@@ -268,7 +265,9 @@ func (r *Remote) handleDataPacket(h Header, data []byte) {
 	// For local.
 	if h.DestIP == r.LocalPeerIP {
 		if _, err := r.IFace.Write(dec); err != nil {
-			log.Fatalf("Failed to write to interface: %v", err)
+			// This could be a malformed packet from a peer, so we don't crash if it
+			// happens.
+			r.logf("Failed to write to interface: %v", err)
 		}
 		return
 	}
@@ -297,7 +296,6 @@ func (r *Remote) HandleLocalDiscoveryPacket(h Header, srcAddr netip.AddrPort, da
 		SrcIP:   h.SourceIP,
 		SrcAddr: srcAddr,
 	}
-	r.logf("Got local discovery packet from %v.", srcAddr)
 
 	select {
 	case r.messages <- msg:

peer/remotefsm.go

@@ -156,16 +156,13 @@ func (r *remoteFSM) stateServer_onInit(msg controlMsg[packetInit]) {
 }
 
 func (r *remoteFSM) stateServer_onSyn(msg controlMsg[packetSyn]) {
-	r.logf("Got SYN: %v", msg.Packet)
 	r.lastSeen = time.Now()
 	p := msg.Packet
 
 	// Before we can respond to this packet, we need to make sure the
 	// route is setup properly.
 	conf := r.conf()
-	if !conf.Up || conf.Direct != p.Direct {
-		r.logf("Got SYN.")
-	}
+	logSyn := !conf.Up || conf.Direct != p.Direct
 
 	conf.Up = true
 	conf.Direct = p.Direct
@@ -179,6 +176,10 @@ func (r *remoteFSM) stateServer_onSyn(msg controlMsg[packetSyn]) {
 
 	r.updateConf(conf)
 
+	if logSyn {
+		r.logf("Got SYN.")
+	}
+
 	r.sendControl(conf, packetAck{
 		TraceID:       p.TraceID,
 		ToAddr:        conf.DirectAddr,
@@ -429,7 +430,6 @@ func (r *remoteFSM) stateClient_onPingTimer() stateFunc {
 		return r.enterClientInit()
 	}
 
-	r.traceID = newTraceID()
 	r.stateClient_sendSyn(conf)
 	return r.stateClient
 }