client multiplexes AND recovers correctly! (close #31)

 - stabilize rest of WebRTCPeer
 - use uid for the datachannel label
 - store a consistent WebRTC config in the dialer

.travis.yml

@@ -23,6 +23,7 @@ before_install:
 install:
     - go get -u github.com/smartystreets/goconvey
     - go get -u github.com/keroserene/go-webrtc
+    - go get -u github.com/dchest/uniuri
     - go get -u git.torproject.org/pluggable-transports/goptlib.git
     - pushd proxy
     - npm install

client/client_test.go

@@ -49,7 +49,7 @@ type FakeDialer struct{}
 
 func (w FakeDialer) Catch() (Snowflake, error) {
 	fmt.Println("Caught a dummy snowflake.")
-	return &webRTCConn{}, nil
+	return &WebRTCPeer{}, nil
 }
 
 type FakeSocksConn struct {
@@ -63,9 +63,9 @@ func (f FakeSocksConn) Reject() error {
 }
 func (f FakeSocksConn) Grant(addr *net.TCPAddr) error { return nil }
 
-type FakePeers struct{ toRelease *webRTCConn }
+type FakePeers struct{ toRelease *WebRTCPeer }
 
-func (f FakePeers) Collect() (Snowflake, error) { return &webRTCConn{}, nil }
+func (f FakePeers) Collect() (Snowflake, error) { return &WebRTCPeer{}, nil }
 func (f FakePeers) Pop() Snowflake              { return nil }
 func (f FakePeers) Melted() <-chan struct{}     { return nil }
 
@@ -141,7 +141,7 @@ func TestSnowflakeClient(t *testing.T) {
 			cnt := 5
 			p := NewPeers(cnt)
 			for i := 0; i < cnt; i++ {
-				p.activePeers.PushBack(&webRTCConn{})
+				p.activePeers.PushBack(&WebRTCPeer{})
 			}
 			So(p.Count(), ShouldEqual, cnt)
 			p.End()

client/peers.go

@@ -70,7 +70,7 @@ func (p *Peers) Pop() Snowflake {
 	var ok bool
 	for nil == snowflake {
 		snowflake, ok = <-p.snowflakeChan
-		conn := snowflake.(*webRTCConn)
+		conn := snowflake.(*WebRTCPeer)
 		if !ok {
 			return nil
 		}
@@ -79,7 +79,7 @@ func (p *Peers) Pop() Snowflake {
 		}
 	}
 	// Set to use the same rate-limited traffic logger to keep consistency.
-	snowflake.(*webRTCConn).BytesLogger = p.BytesLogger
+	snowflake.(*WebRTCPeer).BytesLogger = p.BytesLogger
 	return snowflake
 }
 
@@ -99,7 +99,7 @@ func (p *Peers) Count() int {
 func (p *Peers) purgeClosedPeers() {
 	for e := p.activePeers.Front(); e != nil; {
 		next := e.Next()
-		conn := e.Value.(*webRTCConn)
+		conn := e.Value.(*WebRTCPeer)
 		// Purge those marked for deletion.
 		if conn.closed {
 			p.activePeers.Remove(e)
@@ -115,7 +115,7 @@ func (p *Peers) End() {
 	cnt := p.Count()
 	for e := p.activePeers.Front(); e != nil; {
 		next := e.Next()
-		conn := e.Value.(*webRTCConn)
+		conn := e.Value.(*WebRTCPeer)
 		conn.Close()
 		p.activePeers.Remove(e)
 		e = next

client/rendezvous.go

@@ -115,17 +115,19 @@ func (bc *BrokerChannel) Negotiate(offer *webrtc.SessionDescription) (
 // Implements the |Tongue| interface to catch snowflakes, using BrokerChannel.
 type WebRTCDialer struct {
 	*BrokerChannel
-	// webrtcConfig *webrtc.Configuration
-	iceServers IceServerList
+	webrtcConfig *webrtc.Configuration
 }
 
 func NewWebRTCDialer(
 	broker *BrokerChannel, iceServers IceServerList) *WebRTCDialer {
-
+	config := webrtc.NewConfiguration(iceServers...)
+	if nil == config {
+		log.Println("Unable to prepare WebRTC configuration.")
+		return nil
+	}
 	return &WebRTCDialer{
 		BrokerChannel: broker,
-		iceServers:    iceServers,
-		// webrtcConfig:  config,
+		webrtcConfig:  config,
 	}
 }
 
@@ -136,8 +138,7 @@ func (w WebRTCDialer) Catch() (Snowflake, error) {
 	}
 	// TODO: [#3] Fetch ICE server information from Broker.
 	// TODO: [#18] Consider TURN servers here too.
-	config := webrtc.NewConfiguration(w.iceServers...)
-	connection := NewWebRTCConnection(config, w.BrokerChannel)
+	connection := NewWebRTCConnection(w.webrtcConfig, w.BrokerChannel)
 	err := connection.Connect()
 	return connection, err
 }
@@ -149,7 +150,7 @@ func (w WebRTCDialer) Catch() (Snowflake, error) {
 type CopyPasteDialer struct {
 	webrtcConfig *webrtc.Configuration
 	signal       *os.File
-	current      *webRTCConn
+	current      *WebRTCPeer
 }
 
 func NewCopyPasteDialer(iceServers IceServerList) *CopyPasteDialer {

client/snowflake.go

@@ -75,7 +75,6 @@ func handler(socks SocksConnector, snowflakes SnowflakeCollector) error {
 		handlerChan <- -1
 	}()
 	// Obtain an available WebRTC remote. May block.
-	log.Println("handler: awaiting Snowflake...")
 	snowflake := snowflakes.Pop()
 	if nil == snowflake {
 		socks.Reject()
@@ -148,6 +147,10 @@ func main() {
 		// Otherwise, use manual copy and pasting of SDP messages.
 		snowflakes.Tongue = NewCopyPasteDialer(iceServers)
 	}
+	if nil == snowflakes.Tongue {
+		log.Fatal("Unable to prepare rendezvous method.")
+		return
+	}
 	// Use a real logger to periodically output how much traffic is happening.
 	snowflakes.BytesLogger = &BytesSyncLogger{
 		inboundChan: make(chan int, 5), outboundChan: make(chan int, 5),
@@ -212,4 +215,5 @@ func main() {
 		case sig = <-sigChan:
 		}
 	}
+	log.Println("snowflake is done.")
 }

client/torrc

@@ -5,6 +5,6 @@ ClientTransportPlugin snowflake exec ./client \
 -url https://snowflake-reg.appspot.com/ \
 -front www.google.com \
 -ice stun:stun.l.google.com:19302 \
--max 1
+-max 4
 
 Bridge snowflake 0.0.3.0:1

client/util.go

@@ -2,10 +2,11 @@ package main
 
 import (
 	"fmt"
-	"github.com/keroserene/go-webrtc"
 	"log"
 	"strings"
 	"time"
+
+	"github.com/keroserene/go-webrtc"
 )
 
 const (

client/webrtc.go

@@ -3,16 +3,22 @@ package main
 import (
 	"bytes"
 	"errors"
-	"github.com/keroserene/go-webrtc"
 	"io"
 	"log"
 	"time"
+
+	"github.com/dchest/uniuri"
+	"github.com/keroserene/go-webrtc"
 )
 
 // Remote WebRTC peer.
 // Implements the |Snowflake| interface, which includes
 // |io.ReadWriter|, |Resetter|, and |Connector|.
-type webRTCConn struct {
+//
+// Handles preparation of go-webrtc PeerConnection. Only ever has
+// one DataChannel.
+type WebRTCPeer struct {
+	id        string
 	config    *webrtc.Configuration
 	pc        *webrtc.PeerConnection
 	transport SnowflakeDataChannel // Holds the WebRTC DataChannel.
@@ -33,13 +39,13 @@ type webRTCConn struct {
 
 // Read bytes from local SOCKS.
 // As part of |io.ReadWriter|
-func (c *webRTCConn) Read(b []byte) (int, error) {
+func (c *WebRTCPeer) Read(b []byte) (int, error) {
 	return c.recvPipe.Read(b)
 }
 
 // Writes bytes out to remote WebRTC.
 // As part of |io.ReadWriter|
-func (c *webRTCConn) Write(b []byte) (int, error) {
+func (c *WebRTCPeer) Write(b []byte) (int, error) {
 	c.BytesLogger.AddOutbound(len(b))
 	if nil == c.transport {
 		log.Printf("Buffered %d bytes --> WebRTC", len(b))
@@ -51,7 +57,7 @@ func (c *webRTCConn) Write(b []byte) (int, error) {
 }
 
 // As part of |Snowflake|
-func (c *webRTCConn) Close() error {
+func (c *WebRTCPeer) Close() error {
 	var err error = nil
 	log.Printf("WebRTC: Closing")
 	c.cleanup()
@@ -61,7 +67,7 @@ func (c *webRTCConn) Close() error {
 }
 
 // As part of |Resetter|
-func (c *webRTCConn) Reset() {
+func (c *WebRTCPeer) Reset() {
 	c.Close()
 	go func() {
 		c.reset <- struct{}{}
@@ -70,12 +76,13 @@ func (c *webRTCConn) Reset() {
 }
 
 // As part of |Resetter|
-func (c *webRTCConn) WaitForReset() { <-c.reset }
+func (c *WebRTCPeer) WaitForReset() { <-c.reset }
 
 // Construct a WebRTC PeerConnection.
 func NewWebRTCConnection(config *webrtc.Configuration,
-	broker *BrokerChannel) *webRTCConn {
-	connection := new(webRTCConn)
+	broker *BrokerChannel) *WebRTCPeer {
+	connection := new(WebRTCPeer)
+	connection.id = "snowflake-" + uniuri.New()
 	connection.config = config
 	connection.broker = broker
 	connection.offerChannel = make(chan *webrtc.SessionDescription, 1)
@@ -94,7 +101,8 @@ func NewWebRTCConnection(config *webrtc.Configuration,
 }
 
 // As part of |Connector| interface.
-func (c *webRTCConn) Connect() error {
+func (c *WebRTCPeer) Connect() error {
+	log.Println(c.id, " connecting...")
 	// TODO: When go-webrtc is more stable, it's possible that a new
 	// PeerConnection won't need to be re-prepared each time.
 	err := c.preparePeerConnection()
@@ -113,7 +121,7 @@ func (c *webRTCConn) Connect() error {
 }
 
 // Create and prepare callbacks on a new WebRTC PeerConnection.
-func (c *webRTCConn) preparePeerConnection() error {
+func (c *WebRTCPeer) preparePeerConnection() error {
 	if nil != c.pc {
 		c.pc.Close()
 		c.pc = nil
@@ -161,11 +169,11 @@ func (c *webRTCConn) preparePeerConnection() error {
 }
 
 // Create a WebRTC DataChannel locally.
-func (c *webRTCConn) establishDataChannel() error {
+func (c *WebRTCPeer) establishDataChannel() error {
 	if c.transport != nil {
 		panic("Unexpected datachannel already exists!")
 	}
-	dc, err := c.pc.CreateDataChannel("snowflake", webrtc.Init{})
+	dc, err := c.pc.CreateDataChannel(c.id, webrtc.Init{})
 	// Triggers "OnNegotiationNeeded" on the PeerConnection, which will prepare
 	// an SDP offer while other goroutines operating on this struct handle the
 	// signaling. Eventually fires "OnOpen".
@@ -220,7 +228,7 @@ func (c *webRTCConn) establishDataChannel() error {
 	return nil
 }
 
-func (c *webRTCConn) sendOfferToBroker() {
+func (c *WebRTCPeer) sendOfferToBroker() {
 	if nil == c.broker {
 		return
 	}
@@ -235,7 +243,7 @@ func (c *webRTCConn) sendOfferToBroker() {
 
 // Block until an SDP offer is available, send it to either
 // the Broker or signal pipe, then await for the SDP answer.
-func (c *webRTCConn) exchangeSDP() error {
+func (c *WebRTCPeer) exchangeSDP() error {
 	select {
 	case offer := <-c.offerChannel:
 		// Display for copy-paste when no broker available.
@@ -272,7 +280,7 @@ func (c *webRTCConn) exchangeSDP() error {
 }
 
 // Close all channels and transports
-func (c *webRTCConn) cleanup() {
+func (c *WebRTCPeer) cleanup() {
 	if nil != c.offerChannel {
 		close(c.offerChannel)
 	}