WIP

README.md

@@ -1,9 +1,5 @@
 # vppn: Virtual Potentially Private Network
 
-## TODO
-
-* Add `-force-init` argument to `node` main?
-
 ## Hub Server Configuration
 
 ```
@@ -33,7 +29,6 @@ WorkingDirectory=/home/user/
 ExecStart=/home/user/hub -listen <addr>:https -root-dir=/home/user
 Restart=always
 RestartSec=8
-TimeoutStopSec=24
 
 [Install]
 WantedBy=default.target
@@ -70,7 +65,6 @@ WorkingDirectory=/home/user/
 ExecStart=/home/user/vppn -name vppn -hub-address https://my.hub -api-key 1234567890
 Restart=always
 RestartSec=8
-TimeoutStopSec=24
 
 [Install]
 WantedBy=default.target

node/README.md

@@ -0,0 +1,17 @@
+# VPPN Peer Code
+
+## Refactoring for Testability
+
+* [ ] connWriter
+  * [ ] Separate send/relay calls
+* [x] mcWriter
+* [x] ifWriter
+* [ ] ifReader
+* [ ] connReader
+* [ ] mcReader
+* [ ] hubPoller
+* [ ] supervisor
+
+## Updates
+
+* [ ] Send timing info w/ syn/ack packets

node/conn.go

@@ -1,50 +1,3 @@
 package node
 
-import (
-	"io"
-	"log"
-	"net"
-	"net/netip"
-	"sync"
-)
-
 // ----------------------------------------------------------------------------
-
-type connWriter struct {
-	lock sync.Mutex
-	conn *net.UDPConn
-}
-
-func newConnWriter(conn *net.UDPConn) *connWriter {
-	return &connWriter{conn: conn}
-}
-
-func (w *connWriter) WriteTo(packet []byte, addr netip.AddrPort) {
-	// Even though a conn is safe for concurrent use, it turns out that a mutex
-	// in Go is more fair when there's contention. Without this lock, control
-	// packets may fail to be sent in a timely manner causing timeouts.
-	w.lock.Lock()
-	if _, err := w.conn.WriteToUDPAddrPort(packet, addr); err != nil {
-		log.Printf("Failed to write to UDP port: %v", err)
-	}
-	w.lock.Unlock()
-}
-
-// ----------------------------------------------------------------------------
-
-type ifWriter struct {
-	lock  sync.Mutex
-	iface io.ReadWriteCloser
-}
-
-func newIFWriter(iface io.ReadWriteCloser) *ifWriter {
-	return &ifWriter{iface: iface}
-}
-
-func (w *ifWriter) Write(packet []byte) {
-	w.lock.Lock()
-	if _, err := w.iface.Write(packet); err != nil {
-		log.Fatalf("Failed to write to interface: %v", err)
-	}
-	w.lock.Unlock()
-}

node/connwriter.go

@@ -0,0 +1,146 @@
+package node
+
+import (
+	"log"
+	"net/netip"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+// ----------------------------------------------------------------------------
+
+type peerRoute struct {
+	IP            byte
+	Up            bool // True if data can be sent on the route.
+	Relay         bool // True if the peer is a relay.
+	Direct        bool // True if this is a direct connection.
+	PubSignKey    []byte
+	ControlCipher *controlCipher
+	DataCipher    *dataCipher
+	RemoteAddr    netip.AddrPort // Remote address if directly connected.
+}
+
+// ----------------------------------------------------------------------------
+
+type udpAddrPortWriter interface {
+	WriteToUDPAddrPort([]byte, netip.AddrPort) (int, error)
+}
+
+type marshaller interface {
+	Marshal([]byte) []byte
+}
+
+// ----------------------------------------------------------------------------
+
+type connWriter struct {
+	localIP byte
+	conn    udpAddrPortWriter
+
+	// For sending control packets.
+	cBuf1 []byte
+	cBuf2 []byte
+
+	// For sending data packets.
+	dBuf1 []byte
+	dBuf2 []byte
+
+	counters [256]uint64
+
+	// Lock around for sending on UDP Conn.
+	wLock sync.Mutex
+}
+
+func newConnWriter(conn udpAddrPortWriter, localIP byte) *connWriter {
+	w := &connWriter{
+		localIP: localIP,
+		conn:    conn,
+		cBuf1:   make([]byte, bufferSize),
+		cBuf2:   make([]byte, bufferSize),
+		dBuf1:   make([]byte, bufferSize),
+		dBuf2:   make([]byte, bufferSize),
+	}
+	for i := range w.counters {
+		w.counters[i] = uint64(time.Now().Unix()<<30 + 1)
+	}
+	return w
+}
+
+// Not safe for concurrent use. Should only be called by supervisor.
+func (w *connWriter) SendControlPacket(pkt marshaller, route *peerRoute) {
+	buf := pkt.Marshal(w.cBuf1)
+	h := header{
+		StreamID: controlStreamID,
+		Counter:  atomic.AddUint64(&w.counters[route.IP], 1),
+		SourceIP: w.localIP,
+		DestIP:   route.IP,
+	}
+	buf = route.ControlCipher.Encrypt(h, buf, w.cBuf2)
+	w.writeTo(buf, route.RemoteAddr)
+}
+
+func (w *connWriter) RelayControlPacket(pkt marshaller, route, relay *peerRoute) {
+	buf := pkt.Marshal(w.cBuf1)
+	h := header{
+		StreamID: controlStreamID,
+		Counter:  atomic.AddUint64(&w.counters[route.IP], 1),
+		SourceIP: w.localIP,
+		DestIP:   route.IP,
+	}
+	buf = route.ControlCipher.Encrypt(h, buf, w.cBuf2)
+	w.relayPacket(buf, w.cBuf1, route, relay)
+}
+
+// Not safe for concurrent use. Should only be called by ifReader.
+func (w *connWriter) SendDataPacket(pkt []byte, route, relay *peerRoute) {
+	h := header{
+		StreamID: dataStreamID,
+		Counter:  atomic.AddUint64(&w.counters[route.IP], 1),
+		SourceIP: w.localIP,
+		DestIP:   route.IP,
+	}
+
+	enc := route.DataCipher.Encrypt(h, pkt, w.dBuf1)
+
+	if route.Direct {
+		w.writeTo(enc, route.RemoteAddr)
+		return
+	}
+
+	w.relayPacket(enc, w.dBuf2, route, relay)
+}
+
+// TODO: RelayDataPacket
+
+// Safe for concurrent use. Should only be called by connReader.
+//
+// This function will send pkt to the peer directly. This is used when a peer
+// is acting as a relay and is forwarding already encrypted data for another
+// peer.
+func (w *connWriter) SendEncryptedDataPacket(pkt []byte, route *peerRoute) {
+	w.writeTo(pkt, route.RemoteAddr)
+}
+
+func (w *connWriter) relayPacket(data, buf []byte, route, relay *peerRoute) {
+	if relay == nil || !relay.Up {
+		return
+	}
+
+	h := header{
+		StreamID: dataStreamID,
+		Counter:  atomic.AddUint64(&w.counters[relay.IP], 1),
+		SourceIP: w.localIP,
+		DestIP:   route.IP,
+	}
+
+	enc := relay.DataCipher.Encrypt(h, data, buf)
+	w.writeTo(enc, relay.RemoteAddr)
+}
+
+func (w *connWriter) writeTo(packet []byte, addr netip.AddrPort) {
+	w.wLock.Lock()
+	if _, err := w.conn.WriteToUDPAddrPort(packet, addr); err != nil {
+		log.Printf("Failed to write to UDP port: %v", err)
+	}
+	w.wLock.Unlock()
+}

node/connwriter_test.go

@@ -0,0 +1,291 @@
+package node
+
+import (
+	"bytes"
+	"net/netip"
+	"testing"
+)
+
+// ----------------------------------------------------------------------------
+
+type testUDPPacket struct {
+	Addr netip.AddrPort
+	Data []byte
+}
+
+type testUDPAddrPortWriter struct {
+	written []testUDPPacket
+}
+
+func (w *testUDPAddrPortWriter) WriteToUDPAddrPort(b []byte, addr netip.AddrPort) (int, error) {
+	w.written = append(w.written, testUDPPacket{
+		Addr: addr,
+		Data: bytes.Clone(b),
+	})
+	return len(b), nil
+}
+
+func (w *testUDPAddrPortWriter) Written() []testUDPPacket {
+	out := w.written
+	w.written = []testUDPPacket{}
+	return out
+}
+
+// ----------------------------------------------------------------------------
+
+type testPacket string
+
+func (p testPacket) Marshal(b []byte) []byte {
+	b = b[:len(p)]
+	copy(b, []byte(p))
+	return b
+}
+
+// ----------------------------------------------------------------------------
+
+func testConnWriter_getTestRoutes() (local, remote, relayLocal, relayRemote *peerRoute) {
+	localKeys := generateKeys()
+	remoteKeys := generateKeys()
+
+	local = &peerRoute{
+		IP:            2,
+		Up:            true,
+		Relay:         false,
+		PubSignKey:    remoteKeys.PubSignKey,
+		ControlCipher: newControlCipher(localKeys.PrivKey, remoteKeys.PubKey),
+		DataCipher:    newDataCipher(),
+		RemoteAddr:    netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 1, 1, 2}), 100),
+	}
+
+	remote = &peerRoute{
+		IP:            1,
+		Up:            true,
+		Relay:         false,
+		PubSignKey:    localKeys.PubSignKey,
+		ControlCipher: newControlCipher(remoteKeys.PrivKey, localKeys.PubKey),
+		DataCipher:    local.DataCipher,
+		RemoteAddr:    netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 1, 1, 1}), 100),
+	}
+
+	rLocalKeys := generateKeys()
+	rRemoteKeys := generateKeys()
+
+	relayLocal = &peerRoute{
+		IP:            3,
+		Up:            true,
+		Relay:         true,
+		Direct:        true,
+		PubSignKey:    rRemoteKeys.PubSignKey,
+		ControlCipher: newControlCipher(rLocalKeys.PrivKey, rRemoteKeys.PubKey),
+		DataCipher:    newDataCipher(),
+		RemoteAddr:    netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 1, 1, 3}), 100),
+	}
+
+	relayRemote = &peerRoute{
+		IP:            1,
+		Up:            true,
+		Relay:         false,
+		Direct:        true,
+		PubSignKey:    rLocalKeys.PubSignKey,
+		ControlCipher: newControlCipher(rRemoteKeys.PrivKey, rLocalKeys.PubKey),
+		DataCipher:    relayLocal.DataCipher,
+		RemoteAddr:    netip.AddrPortFrom(netip.AddrFrom4([4]byte{1, 1, 1, 1}), 100),
+	}
+
+	return
+}
+
+// ----------------------------------------------------------------------------
+
+// Testing if we can send a control packet directly to the remote route.
+func TestConnWriter_SendControlPacket_direct(t *testing.T) {
+	route, rRoute, _, _ := testConnWriter_getTestRoutes()
+	route.Direct = true
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+	in := testPacket("hello world!")
+
+	w.SendControlPacket(in, route)
+	out := writer.Written()
+	if len(out) != 1 {
+		t.Fatal(out)
+	}
+
+	if out[0].Addr != route.RemoteAddr {
+		t.Fatal(out[0])
+	}
+
+	dec, ok := rRoute.ControlCipher.Decrypt(out[0].Data, make([]byte, 1024))
+	if !ok {
+		t.Fatal(ok)
+	}
+	if string(dec) != string(in) {
+		t.Fatal(dec)
+	}
+}
+
+// Testing if we can relay a packet via an intermediary.
+func TestConnWriter_SendControlPacket_relay(t *testing.T) {
+	route, rRoute, relay, rRelay := testConnWriter_getTestRoutes()
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+	in := testPacket("hello world!")
+
+	w.RelayControlPacket(in, route, relay)
+
+	out := writer.Written()
+	if len(out) != 1 {
+		t.Fatal(out)
+	}
+
+	if out[0].Addr != relay.RemoteAddr {
+		t.Fatal(out[0])
+	}
+
+	dec, ok := rRelay.DataCipher.Decrypt(out[0].Data, make([]byte, 1024))
+	if !ok {
+		t.Fatal(ok)
+	}
+
+	dec2, ok := rRoute.ControlCipher.Decrypt(dec, make([]byte, 1024))
+	if !ok {
+		t.Fatal(ok)
+	}
+
+	if string(dec2) != string(in) {
+		t.Fatal(dec2)
+	}
+}
+
+// Testing that a nil relay doesn't cause an issue.
+func TestConnWriter_SendControlPacket_relay_relayNil(t *testing.T) {
+	route, rRoute, _, _ := testConnWriter_getTestRoutes()
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+	in := testPacket("hello world!")
+
+	w.RelayControlPacket(in, route, nil)
+
+	out := writer.Written()
+	if len(out) != 0 {
+		t.Fatal(out)
+	}
+
+}
+
+// Testing that we don't send anything if the relay isn't up.
+func TestConnWriter_SendControlPacket_relay_relayNotUp(t *testing.T) {
+	route, rRoute, relay, _ := testConnWriter_getTestRoutes()
+	relay.Up = false
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+	in := testPacket("hello world!")
+
+	w.RelayControlPacket(in, route, relay)
+
+	out := writer.Written()
+	if len(out) != 0 {
+		t.Fatal(out)
+	}
+}
+
+// Testing that we can send a data packet directly to a remote route.
+func TestConnWriter_SendDataPacket_direct(t *testing.T) {
+	route, rRoute, _, _ := testConnWriter_getTestRoutes()
+	route.Direct = true
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+
+	in := []byte("hello world!")
+	w.SendDataPacket(in, route, nil)
+
+	out := writer.Written()
+	if len(out) != 1 {
+		t.Fatal(out)
+	}
+
+	if out[0].Addr != route.RemoteAddr {
+		t.Fatal(out[0])
+	}
+
+	dec, ok := rRoute.DataCipher.Decrypt(out[0].Data, make([]byte, 1024))
+	if !ok {
+		t.Fatal(ok)
+	}
+
+	if !bytes.Equal(dec, in) {
+		t.Fatal(dec)
+	}
+}
+
+// Testing that we can relay a data packet via a relay.
+func TestConnWriter_SendDataPacket_relay(t *testing.T) {
+	route, rRoute, relay, rRelay := testConnWriter_getTestRoutes()
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+	in := []byte("Hello world!")
+
+	w.SendDataPacket(in, route, relay)
+
+	out := writer.Written()
+	if len(out) != 1 {
+		t.Fatal(out)
+	}
+
+	if out[0].Addr != relay.RemoteAddr {
+		t.Fatal(out[0])
+	}
+
+	dec, ok := rRelay.DataCipher.Decrypt(out[0].Data, make([]byte, 1024))
+	if !ok {
+		t.Fatal(ok)
+	}
+
+	dec2, ok := rRoute.DataCipher.Decrypt(dec, make([]byte, 1024))
+	if !ok {
+		t.Fatal(ok)
+	}
+
+	if !bytes.Equal(dec2, in) {
+		t.Fatal(dec2)
+	}
+}
+
+// Testing that we don't attempt to relay if the relay is nil.
+func TestConnWriter_SendDataPacket_relay_relayNil(t *testing.T) {
+	route, rRoute, _, _ := testConnWriter_getTestRoutes()
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+	in := []byte("Hello world!")
+
+	w.SendDataPacket(in, route, nil)
+
+	out := writer.Written()
+	if len(out) != 0 {
+		t.Fatal(out)
+	}
+}
+
+// Testing that we don't attempt to relay if the relay isn't up.
+func TestConnWriter_SendDataPacket_relay_relayNotUp(t *testing.T) {
+	route, rRoute, relay, _ := testConnWriter_getTestRoutes()
+	relay.Up = false
+
+	writer := &testUDPAddrPortWriter{}
+	w := newConnWriter(writer, rRoute.IP)
+	in := []byte("Hello world!")
+
+	w.SendDataPacket(in, route, relay)
+
+	out := writer.Written()
+	if len(out) != 0 {
+		t.Fatal(out)
+	}
+}

node/crypto.go

@@ -0,0 +1,30 @@
+package node
+
+import (
+	"crypto/rand"
+	"log"
+
+	"golang.org/x/crypto/nacl/box"
+	"golang.org/x/crypto/nacl/sign"
+)
+
+type cryptoKeys struct {
+	PubKey      []byte
+	PrivKey     []byte
+	PubSignKey  []byte
+	PrivSignKey []byte
+}
+
+func generateKeys() cryptoKeys {
+	pubKey, privKey, err := box.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate encryption keys: %v", err)
+	}
+
+	pubSignKey, privSignKey, err := sign.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate signing keys: %v", err)
+	}
+
+	return cryptoKeys{pubKey[:], privKey[:], pubSignKey[:], privSignKey[:]}
+}

node/data-flow.dot

@@ -0,0 +1,14 @@
+digraph d {
+    ifReader   -> connWriter;
+    connReader -> ifWriter;
+    connReader -> connWriter;
+    connReader -> supervisor;
+    mcReader   -> supervisor;
+    supervisor -> connWriter;
+    supervisor -> mcWriter;
+    hubPoller  -> supervisor;
+
+    connWriter [shape="box"];
+    mcWriter [shape="box"];
+    ifWriter [shape="box"];
+}

node/globalfuncs.go

@@ -1,65 +1,8 @@
 package node
 
-import (
-	"sync/atomic"
-)
-
 func getRelayRoute() *peerRoute {
 	if ip := relayIP.Load(); ip != nil {
 		return routingTable[*ip].Load()
 	}
 	return nil
 }
-
-func _sendControlPacket(pkt interface{ Marshal([]byte) []byte }, route peerRoute, buf1, buf2 []byte) {
-	buf := pkt.Marshal(buf2)
-	h := header{
-		StreamID: controlStreamID,
-		Counter:  atomic.AddUint64(&sendCounters[route.IP], 1),
-		SourceIP: localIP,
-		DestIP:   route.IP,
-	}
-	buf = route.ControlCipher.Encrypt(h, buf, buf1)
-
-	if route.Direct {
-		_conn.WriteTo(buf, route.RemoteAddr)
-		return
-	}
-
-	_relayPacket(route.IP, buf, buf2)
-}
-
-func _sendDataPacket(route *peerRoute, pkt, buf1, buf2 []byte) {
-	h := header{
-		StreamID: dataStreamID,
-		Counter:  atomic.AddUint64(&sendCounters[route.IP], 1),
-		SourceIP: localIP,
-		DestIP:   route.IP,
-	}
-
-	enc := route.DataCipher.Encrypt(h, pkt, buf1)
-
-	if route.Direct {
-		_conn.WriteTo(enc, route.RemoteAddr)
-		return
-	}
-
-	_relayPacket(route.IP, enc, buf2)
-}
-
-func _relayPacket(destIP byte, data, buf []byte) {
-	relayRoute := getRelayRoute()
-	if relayRoute == nil || !relayRoute.Up || !relayRoute.Relay {
-		return
-	}
-
-	h := header{
-		StreamID: dataStreamID,
-		Counter:  atomic.AddUint64(&sendCounters[relayRoute.IP], 1),
-		SourceIP: localIP,
-		DestIP:   destIP,
-	}
-
-	enc := relayRoute.DataCipher.Encrypt(h, data, buf)
-	_conn.WriteTo(enc, relayRoute.RemoteAddr)
-}

node/globals.go

@@ -5,7 +5,6 @@ import (
 	"net/netip"
 	"net/url"
 	"sync/atomic"
-	"time"
 )
 
 const (
@@ -17,21 +16,9 @@ const (
 	signOverhead          = 64
 )
 
-var (
-	multicastIP   = netip.AddrFrom4([4]byte{224, 0, 0, 157})
-	multicastAddr = net.UDPAddrFromAddrPort(netip.AddrPortFrom(multicastIP, 4560))
-)
-
-type peerRoute struct {
-	IP            byte
-	Up            bool // True if data can be sent on the route.
-	Relay         bool // True if the peer is a relay.
-	Direct        bool // True if this is a direct connection.
-	PubSignKey    []byte
-	ControlCipher *controlCipher
-	DataCipher    *dataCipher
-	RemoteAddr    netip.AddrPort // Remote address if directly connected.
-}
+var multicastAddr = net.UDPAddrFromAddrPort(netip.AddrPortFrom(
+	netip.AddrFrom4([4]byte{224, 0, 0, 157}),
+	4560))
 
 var (
 	hubURL *url.URL
@@ -45,20 +32,7 @@ var (
 	privKey     []byte
 	privSignKey []byte
 
-	// Shared interface for writing.
-	_iface *ifWriter
-
-	// Shared connection for writing.
-	_conn *connWriter
-
-	// Counters for sending to each peer.
-	sendCounters [256]uint64 = func() (out [256]uint64) {
-		for i := range out {
-			out[i] = uint64(time.Now().Unix()<<30 + 1)
-		}
-		return
-	}()
-
+	// TODO: Doesn't need to be global.
 	// Duplicate checkers for incoming packets.
 	dupChecks [256]*dupCheck = func() (out [256]*dupCheck) {
 		for i := range out {
@@ -67,9 +41,11 @@ var (
 		return
 	}()
 
+	// TODO: Doesn't need to be global .
 	// Messages for the supervisor.
 	messages = make(chan any, 1024)
 
+	// TODO: Doesn't need to be global .
 	// Global routing table.
 	routingTable [256]*atomic.Pointer[peerRoute] = func() (out [256]*atomic.Pointer[peerRoute]) {
 		for i := range out {
@@ -82,5 +58,6 @@ var (
 	// Managed by the relayManager.
 	relayIP = &atomic.Pointer[byte]{}
 
+	// TODO: Only used by supervisor: can make local there.
 	publicAddrs = newPubAddrStore()
 )

node/ifreader.go

@@ -0,0 +1,102 @@
+package node
+
+import (
+	"io"
+	"log"
+	"sync/atomic"
+)
+
+type ifReader struct {
+	iface           io.Reader
+	routes          [256]*atomic.Pointer[peerRoute]
+	relay           *atomic.Pointer[peerRoute]
+	sendDataPacket  func(pkt []byte, route *peerRoute)
+	relayDataPacket func(pkt []byte, route, relay *peerRoute)
+}
+
+func newIFReader(
+	iface io.Reader,
+	routes [256]*atomic.Pointer[peerRoute],
+	relay *atomic.Pointer[peerRoute],
+	sendDataPacket func(pkt []byte, route *peerRoute),
+	relayDackPacket func(pkt []byte, route, relay *peerRoute),
+) *ifReader {
+	return &ifReader{
+		iface:          iface,
+		routes:         routes,
+		relay:          relay,
+		sendDataPacket: sendDataPacket,
+	}
+}
+
+func (r *ifReader) Run() {
+	var (
+		packet   = make([]byte, bufferSize)
+		remoteIP byte
+		ok       bool
+	)
+
+	for {
+		packet = r.readNextPacket(packet)
+		if remoteIP, ok = r.parsePacket(packet); ok {
+			r.sendPacket(packet, remoteIP)
+		}
+	}
+}
+
+func (r *ifReader) sendPacket(pkt []byte, remoteIP byte) {
+	route := r.routes[remoteIP].Load()
+	if !route.Up {
+		log.Printf("Route not connected: %d", remoteIP)
+		return
+	}
+
+	// Direct path => early return.
+	if route.Direct {
+		r.sendDataPacket(pkt, route)
+		return
+	}
+
+	if relay := r.relay.Load(); relay != nil {
+		r.relayDataPacket(pkt, route, relay)
+	}
+}
+
+// Get next packet, returning packet, and destination ip.
+func (r *ifReader) readNextPacket(buf []byte) []byte {
+	n, err := r.iface.Read(buf[:cap(buf)])
+	if err != nil {
+		log.Fatalf("Failed to read from interface: %v", err)
+	}
+
+	return buf[:n]
+}
+
+func (r *ifReader) parsePacket(buf []byte) (byte, bool) {
+	n := len(buf)
+	if n == 0 {
+		return 0, false
+	}
+
+	version := buf[0] >> 4
+
+	switch version {
+	case 4:
+		if n < 20 {
+			log.Printf("Short IPv4 packet: %d", len(buf))
+			return 0, false
+		}
+		return buf[19], true
+
+	case 6:
+		if len(buf) < 40 {
+			log.Printf("Short IPv6 packet: %d", len(buf))
+			return 0, false
+		}
+		return buf[39], true
+
+	default:
+		log.Printf("Invalid IP packet version: %v", version)
+		return 0, false
+	}
+}

node/ifreader_test.go

@@ -0,0 +1,117 @@
+package node
+
+import (
+	"bytes"
+	"net"
+	"sync/atomic"
+	"testing"
+)
+
+// Test that we parse IPv4 packets correctly.
+func TestIFReader_parsePacket_ipv4(t *testing.T) {
+	r := newIFReader(nil, [256]*atomic.Pointer[peerRoute]{}, nil, nil, nil)
+
+	pkt := make([]byte, 1234)
+	pkt[0] = 4 << 4
+	pkt[19] = 128
+
+	if ip, ok := r.parsePacket(pkt); !ok || ip != 128 {
+		t.Fatal(ip, ok)
+	}
+}
+
+// Test that we parse IPv6 packets correctly.
+func TestIFReader_parsePacket_ipv6(t *testing.T) {
+	r := newIFReader(nil, [256]*atomic.Pointer[peerRoute]{}, nil, nil, nil)
+
+	pkt := make([]byte, 1234)
+	pkt[0] = 6 << 4
+	pkt[39] = 42
+
+	if ip, ok := r.parsePacket(pkt); !ok || ip != 42 {
+		t.Fatal(ip, ok)
+	}
+}
+
+// Test that empty packets work as expected.
+func TestIFReader_parsePacket_emptyPacket(t *testing.T) {
+	r := newIFReader(nil, [256]*atomic.Pointer[peerRoute]{}, nil, nil, nil)
+
+	pkt := make([]byte, 0)
+	if ip, ok := r.parsePacket(pkt); ok {
+		t.Fatal(ip, ok)
+	}
+}
+
+// Test that invalid IP versions fail.
+func TestIFReader_parsePacket_invalidIPVersion(t *testing.T) {
+	r := newIFReader(nil, [256]*atomic.Pointer[peerRoute]{}, nil, nil, nil)
+
+	for i := byte(1); i < 16; i++ {
+		if i == 4 || i == 6 {
+			continue
+		}
+		pkt := make([]byte, 1234)
+		pkt[0] = i << 4
+
+		if ip, ok := r.parsePacket(pkt); ok {
+			t.Fatal(i, ip, ok)
+		}
+	}
+}
+
+// Test that short IPv4 packets fail.
+func TestIFReader_parsePacket_shortIPv4(t *testing.T) {
+	r := newIFReader(nil, [256]*atomic.Pointer[peerRoute]{}, nil, nil, nil)
+
+	pkt := make([]byte, 19)
+	pkt[0] = 4 << 4
+
+	if ip, ok := r.parsePacket(pkt); ok {
+		t.Fatal(ip, ok)
+	}
+}
+
+// Test that short IPv6 packets fail.
+func TestIFReader_parsePacket_shortIPv6(t *testing.T) {
+	r := newIFReader(nil, [256]*atomic.Pointer[peerRoute]{}, nil, nil, nil)
+
+	pkt := make([]byte, 39)
+	pkt[0] = 6 << 4
+
+	if ip, ok := r.parsePacket(pkt); ok {
+		t.Fatal(ip, ok)
+	}
+}
+
+// Test that we can read a packet.
+func TestIFReader_readNextpacket(t *testing.T) {
+	in, out := net.Pipe()
+	r := newIFReader(out, [256]*atomic.Pointer[peerRoute]{}, nil, nil, nil)
+	defer in.Close()
+	defer out.Close()
+
+	go in.Write([]byte("hello world!"))
+
+	pkt := r.readNextPacket(make([]byte, bufferSize))
+	if !bytes.Equal(pkt, []byte("hello world!")) {
+		t.Fatalf("%s", pkt)
+	}
+}
+
+// Testing that we can send a packet directly.
+func TestIFReader_sendPacket_direct(t *testing.T) {
+	// TODO
+}
+
+// Testing that we don't send a packet if route isn't up.
+func TestIFReader_sendPacket_directNotUp(t *testing.T) {
+	// TODO
+}
+
+// Testing that we can send a packet via a relay.
+func TestIFReader_sendPacket_relayed(t *testing.T) {
+	// TODO
+}
+
+// Testing that we don't try to send on a nil relay IP.

node/ifwriter.go

@@ -0,0 +1,5 @@
+package node
+
+import "io"
+
+type ifWriter io.Writer

node/localdiscovery_test.go

@@ -20,7 +20,7 @@ func TestLocalDiscoveryPacketSigning(t *testing.T) {
 	privSignKey = privSigKey[:]
 	route := routingTable[localIP].Load()
 	route.IP = byte(localIP)
-	route.PubSignKey = pubSignKey[0:32]
+	route.PubSignKey = pubSignKey[:]
 	routingTable[localIP].Store(route)
 
 	out := buildLocalDiscoveryPacket(buf1, buf2)

node/main.go

@@ -143,10 +143,6 @@ func main() {
 	conn.SetReadBuffer(1024 * 1024 * 8)
 	conn.SetWriteBuffer(1024 * 1024 * 8)
 
-	// Intialize globals.
-	_iface = newIFWriter(iface)
-	_conn = newConnWriter(conn)
-
 	localIP = config.PeerIP
 
 	ip, ok := netip.AddrFromSlice(config.PublicIP)
@@ -169,17 +165,19 @@ func main() {
 		}
 	}()
 
-	go startPeerSuper()
+	sender := newPacketSender(conn)
+
+	go startPeerSuper(routingTable, messages, sender)
 
 	go newHubPoller().Run()
-	go readFromConn(conn)
+	go readFromConn(conn, iface, sender)
 
-	readFromIFace(iface)
+	readFromIFace(iface, sender)
 }
 
 // ----------------------------------------------------------------------------
 
-func readFromConn(conn *net.UDPConn) {
+func readFromConn(conn *net.UDPConn, iface io.ReadWriteCloser, sender dataPacketSender) {
 
 	defer panicHandler()
 
@@ -213,7 +211,7 @@ func readFromConn(conn *net.UDPConn) {
 			handleControlPacket(remoteAddr, h, data, decBuf)
 
 		case dataStreamID:
-			handleDataPacket(h, data, decBuf)
+			handleDataPacket(h, data, decBuf, iface, sender)
 
 		default:
 			log.Printf("Unknown stream ID: %d", h.StreamID)
@@ -263,7 +261,7 @@ func handleControlPacket(addr netip.AddrPort, h header, data, decBuf []byte) {
 
 }
 
-func handleDataPacket(h header, data []byte, decBuf []byte) {
+func handleDataPacket(h header, data []byte, decBuf []byte, iface ifWriter, sender dataPacketSender) {
 	route := routingTable[h.SourceIP].Load()
 	if !route.Up {
 		log.Printf("Not connected (recv).")
@@ -282,7 +280,9 @@ func handleDataPacket(h header, data []byte, decBuf []byte) {
 	}
 
 	if h.DestIP == localIP {
-		_iface.Write(dec)
+		if _, err := iface.Write(dec); err != nil {
+			log.Fatalf("Failed to write to interface: %v", err)
+		}
 		return
 	}
 
@@ -292,16 +292,14 @@ func handleDataPacket(h header, data []byte, decBuf []byte) {
 		return
 	}
 
-	_conn.WriteTo(dec, destRoute.RemoteAddr)
+	sender.SendEncryptedDataPacket(dec, destRoute.RemoteAddr)
 }
 
 // ----------------------------------------------------------------------------
 
-func readFromIFace(iface io.ReadWriteCloser) {
+func readFromIFace(iface io.ReadWriteCloser, sender dataPacketSender) {
 	var (
 		packet   = make([]byte, bufferSize)
-		buf1     = make([]byte, bufferSize)
-		buf2     = make([]byte, bufferSize)
 		remoteIP byte
 		err      error
 	)
@@ -318,6 +316,6 @@ func readFromIFace(iface io.ReadWriteCloser) {
 			continue
 		}
 
-		_sendDataPacket(route, packet, buf1, buf2)
+		sender.SendDataPacket(packet, *route)
 	}
 }

node/main_test.go

@@ -0,0 +1,37 @@
+package node
+
+import (
+	"crypto/rand"
+	"log"
+
+	"golang.org/x/crypto/nacl/box"
+	"golang.org/x/crypto/nacl/sign"
+)
+
+type testPeer struct {
+	IP          byte
+	PubKey      []byte
+	PrivKey     []byte
+	PubSignKey  []byte
+	PrivSignKey []byte
+}
+
+func newTestPeer(ip byte) testPeer {
+	encPubKey, encPrivKey, err := box.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate encryption keys: %v", err)
+	}
+
+	signPubKey, signPrivKey, err := sign.GenerateKey(rand.Reader)
+	if err != nil {
+		log.Fatalf("Failed to generate signing keys: %v", err)
+	}
+
+	return testPeer{
+		IP:          ip,
+		PubKey:      encPubKey[:],
+		PrivKey:     encPrivKey[:],
+		PubSignKey:  signPubKey[:],
+		PrivSignKey: signPrivKey[:],
+	}
+}

node/mcwriter.go

@@ -0,0 +1,62 @@
+package node
+
+import (
+	"log"
+	"net"
+
+	"golang.org/x/crypto/nacl/sign"
+)
+
+// ----------------------------------------------------------------------------
+
+type udpWriter interface {
+	WriteToUDP([]byte, *net.UDPAddr) (int, error)
+}
+
+// ----------------------------------------------------------------------------
+
+func createLocalDiscoveryPacket(localIP byte, signingKey []byte) []byte {
+	h := header{
+		SourceIP: localIP,
+		DestIP:   255,
+	}
+	buf := make([]byte, headerSize)
+	h.Marshal(buf)
+	out := make([]byte, headerSize+signOverhead)
+	return sign.Sign(out[:0], buf, (*[64]byte)(signingKey))
+}
+
+func headerFromLocalDiscoveryPacket(pkt []byte) (h header, ok bool) {
+	if len(pkt) != headerSize+signOverhead {
+		return
+	}
+
+	h.Parse(pkt[signOverhead:])
+	ok = true
+	return
+}
+
+func verifyLocalDiscoveryPacket(pkt, buf []byte, pubSignKey []byte) bool {
+	_, ok := sign.Open(buf[:0], pkt, (*[32]byte)(pubSignKey))
+	return ok
+}
+
+// ----------------------------------------------------------------------------
+
+type mcWriter struct {
+	conn            udpWriter
+	discoveryPacket []byte
+}
+
+func newMCWriter(conn udpWriter, localIP byte, signingKey []byte) *mcWriter {
+	return &mcWriter{
+		conn:            conn,
+		discoveryPacket: createLocalDiscoveryPacket(localIP, signingKey),
+	}
+}
+
+func (w *mcWriter) SendLocalDiscovery() {
+	if _, err := w.conn.WriteToUDP(w.discoveryPacket, multicastAddr); err != nil {
+		log.Printf("Failed to write multicast UDP packet: %v", err)
+	}
+}

node/mcwriter_test.go

@@ -0,0 +1,102 @@
+package node
+
+import (
+	"bytes"
+	"net"
+	"testing"
+)
+
+// ----------------------------------------------------------------------------
+
+// Testing that we can create and verify a local discovery packet.
+func TestVerifyLocalDiscoveryPacket_valid(t *testing.T) {
+	keys := generateKeys()
+
+	created := createLocalDiscoveryPacket(55, keys.PrivSignKey)
+
+	header, ok := headerFromLocalDiscoveryPacket(created)
+	if !ok {
+		t.Fatal(ok)
+	}
+	if header.SourceIP != 55 || header.DestIP != 255 {
+		t.Fatal(header)
+	}
+
+	if !verifyLocalDiscoveryPacket(created, make([]byte, 1024), keys.PubSignKey) {
+		t.Fatal("Not valid")
+	}
+}
+
+// Testing that we don't try to parse short packets.
+func TestVerifyLocalDiscoveryPacket_tooShort(t *testing.T) {
+	keys := generateKeys()
+
+	created := createLocalDiscoveryPacket(55, keys.PrivSignKey)
+
+	_, ok := headerFromLocalDiscoveryPacket(created[:len(created)-1])
+	if ok {
+		t.Fatal(ok)
+	}
+}
+
+// Testing that modifying a packet makes it invalid.
+func TestVerifyLocalDiscoveryPacket_invalid(t *testing.T) {
+	keys := generateKeys()
+
+	created := createLocalDiscoveryPacket(55, keys.PrivSignKey)
+	buf := make([]byte, 1024)
+	for i := range created {
+		modified := bytes.Clone(created)
+		modified[i]++
+		if verifyLocalDiscoveryPacket(modified, buf, keys.PubSignKey) {
+			t.Fatal("Verification should have failed.")
+		}
+	}
+}
+
+// ----------------------------------------------------------------------------
+
+type testUDPWriter struct {
+	written [][]byte
+}
+
+func (w *testUDPWriter) WriteToUDP(b []byte, addr *net.UDPAddr) (int, error) {
+	w.written = append(w.written, bytes.Clone(b))
+	return len(b), nil
+}
+
+func (w *testUDPWriter) Written() [][]byte {
+	out := w.written
+	w.written = [][]byte{}
+	return out
+}
+
+// ----------------------------------------------------------------------------
+
+// Testing that the mcWriter sends local discovery packets as expected.
+func TestMCWriter_SendLocalDiscovery(t *testing.T) {
+	keys := generateKeys()
+	writer := &testUDPWriter{}
+
+	mcw := newMCWriter(writer, 42, keys.PrivSignKey)
+	mcw.SendLocalDiscovery()
+
+	out := writer.Written()
+	if len(out) != 1 {
+		t.Fatal(out)
+	}
+
+	pkt := out[0]
+
+	header, ok := headerFromLocalDiscoveryPacket(pkt)
+	if !ok {
+		t.Fatal(ok)
+	}
+	if header.SourceIP != 42 || header.DestIP != 255 {
+		t.Fatal(header)
+	}
+
+	if !verifyLocalDiscoveryPacket(pkt, make([]byte, 1024), keys.PubSignKey) {
+		t.Fatal("Verification should succeed.")
+	}
+}

node/messages.go

@@ -10,7 +10,8 @@ import (
 type controlMsg[T any] struct {
 	SrcIP   byte
 	SrcAddr netip.AddrPort
-	Packet  T
+	// TODO: RecvdAt int64 // Unixmilli.
+	Packet T
 }
 
 func parseControlMsg(srcIP byte, srcAddr netip.AddrPort, buf []byte) (any, error) {
@@ -55,5 +56,3 @@ type peerUpdateMsg struct {
 // ----------------------------------------------------------------------------
 
 type pingTimerMsg struct{}
-
-// ----------------------------------------------------------------------------

node/packets.go

@@ -21,7 +21,8 @@ const (
 // ----------------------------------------------------------------------------
 
 type synPacket struct {
-	TraceID       uint64   // TraceID to match response w/ request.
+	TraceID uint64 // TraceID to match response w/ request.
+	// TODO: SentAt int64 // Unixmilli.
 	SharedKey     [32]byte // Our shared key.
 	Direct        bool
 	PossibleAddrs [8]netip.AddrPort // Possible public addresses of the sender.

node/packets_test.go

@@ -1,41 +1 @@
 package node
-
-import (
-	"crypto/rand"
-	"net/netip"
-	"reflect"
-	"testing"
-)
-
-func TestPacketSyn(t *testing.T) {
-	in := synPacket{
-		TraceID:  newTraceID(),
-		FromAddr: netip.AddrPortFrom(netip.AddrFrom4([4]byte{4, 5, 6, 7}), 22),
-	}
-	rand.Read(in.SharedKey[:])
-
-	out, err := parseSynPacket(in.Marshal(make([]byte, bufferSize)))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !reflect.DeepEqual(in, out) {
-		t.Fatal("\n", in, "\n", out)
-	}
-}
-
-func TestPacketSynAck(t *testing.T) {
-	in := ackPacket{
-		TraceID:  newTraceID(),
-		FromAddr: netip.AddrPortFrom(netip.AddrFrom4([4]byte{4, 5, 6, 7}), 22),
-	}
-
-	out, err := parseAckPacket(in.Marshal(make([]byte, bufferSize)))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if !reflect.DeepEqual(in, out) {
-		t.Fatal("\n", in, "\n", out)
-	}
-}

node/packetsender.go

@@ -0,0 +1,127 @@
+package node
+
+import (
+	"log"
+	"net"
+	"net/netip"
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+type controlPacketSender interface {
+	SendControlPacket(pkt marshaller, route peerRoute)
+}
+
+type dataPacketSender interface {
+	SendDataPacket(pkt []byte, route peerRoute)
+	SendEncryptedDataPacket(pkt []byte, addr netip.AddrPort)
+}
+
+// ----------------------------------------------------------------------------
+
+type packetSender struct {
+	conn *net.UDPConn
+
+	// For sending control packets.
+	cLock sync.Mutex
+	cBuf1 []byte
+	cBuf2 []byte
+
+	// For sending data packets.
+	dBuf1 []byte
+	dBuf2 []byte
+
+	counters [256]uint64
+
+	// Lock around for sending on UDP Conn.
+	wLock sync.Mutex
+}
+
+func newPacketSender(conn *net.UDPConn) *packetSender {
+	ps := &packetSender{
+		conn:  conn,
+		cBuf1: make([]byte, bufferSize),
+		cBuf2: make([]byte, bufferSize),
+		dBuf1: make([]byte, bufferSize),
+		dBuf2: make([]byte, bufferSize),
+	}
+	for i := range ps.counters {
+		ps.counters[i] = uint64(time.Now().Unix()<<30 + 1)
+	}
+	return ps
+}
+
+// Safe for concurrent use.
+func (sender *packetSender) SendControlPacket(pkt marshaller, route peerRoute) {
+	sender.cLock.Lock()
+	defer sender.cLock.Unlock()
+
+	buf := pkt.Marshal(sender.cBuf1)
+	h := header{
+		StreamID: controlStreamID,
+		Counter:  atomic.AddUint64(&sender.counters[route.IP], 1),
+		SourceIP: localIP,
+		DestIP:   route.IP,
+	}
+	buf = route.ControlCipher.Encrypt(h, buf, sender.cBuf2)
+
+	if route.Direct {
+		sender.writeTo(buf, route.RemoteAddr)
+		return
+	}
+
+	sender.relayPacket(route.IP, buf, sender.cBuf1)
+}
+
+// Not safe for concurrent use.
+func (sender *packetSender) SendDataPacket(pkt []byte, route peerRoute) {
+	h := header{
+		StreamID: dataStreamID,
+		Counter:  atomic.AddUint64(&sender.counters[route.IP], 1),
+		SourceIP: localIP,
+		DestIP:   route.IP,
+	}
+
+	enc := route.DataCipher.Encrypt(h, pkt, sender.dBuf1)
+
+	if route.Direct {
+		sender.writeTo(enc, route.RemoteAddr)
+		return
+	}
+
+	sender.relayPacket(route.IP, enc, sender.dBuf2)
+}
+
+func (sender *packetSender) SendEncryptedDataPacket(pkt []byte, addr netip.AddrPort) {
+	sender.writeTo(pkt, addr)
+}
+
+func (sender *packetSender) relayPacket(destIP byte, data, buf []byte) {
+	ip := relayIP.Load()
+	if ip == nil {
+		return
+	}
+	relayRoute := routingTable[*ip].Load()
+	if relayRoute == nil || !relayRoute.Up || !relayRoute.Relay {
+		return
+	}
+
+	h := header{
+		StreamID: dataStreamID,
+		Counter:  atomic.AddUint64(&sender.counters[relayRoute.IP], 1),
+		SourceIP: localIP,
+		DestIP:   destIP,
+	}
+
+	enc := relayRoute.DataCipher.Encrypt(h, data, buf)
+	sender.writeTo(enc, relayRoute.RemoteAddr)
+}
+
+func (sender *packetSender) writeTo(packet []byte, addr netip.AddrPort) {
+	sender.wLock.Lock()
+	if _, err := sender.conn.WriteToUDPAddrPort(packet, addr); err != nil {
+		log.Printf("Failed to write to UDP port: %v", err)
+	}
+	sender.wLock.Unlock()
+}

node/relaymanager.go

@@ -6,6 +6,7 @@ import (
 	"time"
 )
 
+// TODO: Make part of main loop on ping timer
 func relayManager() {
 	time.Sleep(2 * time.Second)
 	updateRelayRoute()

node/shared.go

@@ -0,0 +1,59 @@
+package node
+
+import (
+	"net/netip"
+	"sync/atomic"
+)
+
+type sharedState struct {
+	// Immutable:
+	HubAddress  string
+	APIKey      string
+	NetName     string
+	LocalIP     byte
+	LocalPub    bool
+	LocalAddr   netip.AddrPort
+	PrivKey     []byte
+	PrivSignKey []byte
+
+	// Mutable:
+	Routes  [256]*atomic.Pointer[peerRoute]
+	RelayIP *atomic.Pointer[byte]
+
+	// Messages for supervisor main loop.
+	Messages chan any
+}
+
+func newSharedState(
+	netName,
+	hubAddress,
+	apiKey string,
+	conf localConfig,
+) (
+	ss sharedState,
+) {
+	ss.HubAddress = hubAddress
+
+	ss.APIKey = apiKey
+	ss.NetName = netName
+	ss.LocalIP = conf.PeerIP
+
+	ip, ok := netip.AddrFromSlice(conf.PublicIP)
+	if ok {
+		ss.LocalPub = true
+		ss.LocalAddr = netip.AddrPortFrom(ip, conf.Port)
+	}
+
+	ss.PrivKey = conf.PrivKey
+	ss.PrivSignKey = conf.PrivSignKey
+
+	for i := range ss.Routes {
+		ss.Routes[i] = &atomic.Pointer[peerRoute]{}
+		ss.Routes[i].Store(&peerRoute{})
+	}
+
+	ss.RelayIP = &atomic.Pointer[byte]{}
+
+	ss.Messages = make(chan any, 1024)
+	return
+}

node/shared_test.go

@@ -0,0 +1,16 @@
+package node
+
+import "vppn/m"
+
+// TODO:
+var sharedStateForTesting = func() sharedState {
+	ss := newSharedState(
+		"testNet",
+		"http://localhost:39499",
+		"123",
+		localConfig{
+			PeerConfig: m.PeerConfig{},
+		})
+
+	return ss
+}

node/supervisor.go

@@ -19,14 +19,17 @@ const (
 
 // ----------------------------------------------------------------------------
 
-func startPeerSuper() {
+func startPeerSuper(
+	routingTable [256]*atomic.Pointer[peerRoute],
+	messages chan any,
+	sender controlPacketSender,
+) {
 	peers := [256]peerState{}
 	for i := range peers {
 		data := &peerStateData{
+			sender:    sender,
 			published: routingTable[i],
 			remoteIP:  byte(i),
-			buf1:      make([]byte, bufferSize),
-			buf2:      make([]byte, bufferSize),
 			limiter: ratelimiter.New(ratelimiter.Config{
 				FillPeriod:   20 * time.Millisecond,
 				MaxWaitCount: 1,
@@ -34,10 +37,10 @@ func startPeerSuper() {
 		}
 		peers[i] = data.OnPeerUpdate(nil)
 	}
-	go runPeerSuper(peers)
+	go runPeerSuper(peers, messages)
 }
 
-func runPeerSuper(peers [256]peerState) {
+func runPeerSuper(peers [256]peerState, messages chan any) {
 	for raw := range messages {
 		switch msg := raw.(type) {
 
@@ -84,6 +87,8 @@ type peerState interface {
 // ----------------------------------------------------------------------------
 
 type peerStateData struct {
+	sender controlPacketSender
+
 	// The purpose of this state machine is to manage this published data.
 	published *atomic.Pointer[peerRoute]
 	staged    peerRoute // Local copy of shared data. See publish().
@@ -95,10 +100,6 @@ type peerStateData struct {
 	peer      *m.Peer
 	remotePub bool
 
-	// Buffers for sending control packets.
-	buf1 []byte
-	buf2 []byte
-
 	// For logging. Set per-state.
 	client bool
 
@@ -129,7 +130,7 @@ func (s *peerStateData) _sendControlPacket(pkt interface{ Marshal([]byte) []byte
 		s.logf("Not sending control packet: rate limited.") // Shouldn't happen.
 		return
 	}
-	_sendControlPacket(pkt, route, s.buf1, s.buf2)
+	s.sender.SendControlPacket(pkt, route)
 }
 
 // ----------------------------------------------------------------------------
@@ -175,8 +176,9 @@ func (s *peerStateData) OnPeerUpdate(peer *m.Peer) peerState {
 
 	s.peer = peer
 	s.staged = peerRoute{
-		IP:            s.remoteIP,
-		PubSignKey:    peer.PubSignKey,
+		IP:         s.remoteIP,
+		PubSignKey: peer.PubSignKey,
+		// TODO: privKey global.
 		ControlCipher: newControlCipher(privKey, peer.PubKey),
 		DataCipher:    newDataCipher(),
 	}
@@ -192,6 +194,7 @@ func (s *peerStateData) OnPeerUpdate(peer *m.Peer) peerState {
 	}
 
 	if s.remotePub == localPub {
+		// TODO: localIP is global
 		if localIP < s.remoteIP {
 			return enterStateServer(s)
 		}
@@ -349,6 +352,7 @@ func (s *stateClient) OnAck(msg controlMsg[ackPacket]) {
 	}
 
 	// Store possible public address if we're not a public node.
+	// TODO: localPub is global, publicAddrs is global.
 	if !localPub && s.remotePub {
 		publicAddrs.Store(msg.Packet.ToAddr)
 	}