simplify client handler & dialWebRTC with independent webRTCConn constructor

client/client_test.go

@@ -33,19 +33,19 @@ func TestConnect(t *testing.T) {
 			}
 			So(c.buffer.Bytes(), ShouldEqual, nil)
 
-			Convey("SendData buffers when datachannel is nil", func() {
-				c.SendData([]byte("test"))
+			Convey("sendData buffers when datachannel is nil", func() {
+				c.sendData([]byte("test"))
 				c.snowflake = nil
 				So(c.buffer.Bytes(), ShouldResemble, []byte("test"))
 			})
 
-			Convey("SendData sends to datachannel when not nil", func() {
+			Convey("sendData sends to datachannel when not nil", func() {
 				mock := new(MockDataChannel)
 				mock.done = make(chan bool)
 				go c.SendLoop()
 				c.writeChannel = make(chan []byte)
 				c.snowflake = mock
-				c.SendData([]byte("test"))
+				c.sendData([]byte("test"))
 				<-mock.done
 				So(c.buffer.Bytes(), ShouldEqual, nil)
 				So(mock.destination.Bytes(), ShouldResemble, []byte("test"))
@@ -55,7 +55,7 @@ func TestConnect(t *testing.T) {
 				c.answerChannel = make(chan *webrtc.SessionDescription)
 				c.config = webrtc.NewConfiguration()
 				c.PreparePeerConnection()
-				c.ReceiveAnswer()
+				c.receiveAnswer()
 				sdp := webrtc.DeserializeSessionDescription("test")
 				c.answerChannel <- sdp
 				So(c.pc.RemoteDescription(), ShouldEqual, sdp)
@@ -65,7 +65,7 @@ func TestConnect(t *testing.T) {
 			Convey("Receive answer fails on nil answer", func() {
 				c.reset = make(chan struct{})
 				c.answerChannel = make(chan *webrtc.SessionDescription)
-				c.ReceiveAnswer()
+				c.receiveAnswer()
 				c.answerChannel <- nil
 				<-c.reset
 			})

client/snowflake.go

@@ -18,7 +18,8 @@ import (
 )
 
 var ptInfo pt.ClientInfo
-var logFile *os.File
+
+// var logFile *os.File
 var brokerURL string
 var frontDomain string
 
@@ -35,13 +36,13 @@ func copyLoop(a, b net.Conn) {
 	wg.Add(2)
 	// TODO fix copy loop recovery
 	go func() {
-		io.Copy(b, a)
-		log.Println("copy loop b-a break")
+		written, err := io.Copy(b, a)
+		log.Println("copy loop b-a break", err, written)
 		wg.Done()
 	}()
 	go func() {
-		io.Copy(a, b)
-		log.Println("copy loop a-b break")
+		written, err := io.Copy(a, b)
+		log.Println("copy loop a-b break", err, written)
 		wg.Done()
 	}()
 	wg.Wait()
@@ -55,27 +56,22 @@ type SnowflakeChannel interface {
 }
 
 // Initialize a WebRTC Connection.
-func dialWebRTC(config *webrtc.Configuration, broker *BrokerChannel) (
-	*webRTCConn, error) {
-	connection := new(webRTCConn)
-	connection.config = config
-	connection.broker = broker
-	connection.offerChannel = make(chan *webrtc.SessionDescription)
-	connection.answerChannel = make(chan *webrtc.SessionDescription)
-	connection.writeChannel = make(chan []byte)
-	connection.errorChannel = make(chan error)
-	connection.reset = make(chan struct{})
-	connection.BytesInfo = &BytesInfo{
-		inboundChan: make(chan int), outboundChan: make(chan int),
-		inbound: 0, outbound: 0, inEvents: 0, outEvents: 0,
+func dialWebRTC() (*webRTCConn, error) {
+
+	// TODO: [#3] Fetch ICE server information from Broker.
+	// TODO: [#18] Consider TURN servers here too.
+	config := webrtc.NewConfiguration(
+		webrtc.OptionIceServer("stun:stun.l.google.com:19302"))
+
+	broker := NewBrokerChannel(brokerURL, frontDomain)
+	if nil == broker {
+		return nil, errors.New("Failed to prepare BrokerChannel")
 	}
-	go connection.BytesInfo.Log()
-
-	// Pipes remain the same even when DataChannel gets switched.
-	connection.recvPipe, connection.writePipe = io.Pipe()
 
+	connection := NewWebRTCConnection(config, broker)
 	go connection.ConnectLoop()
 	go connection.SendLoop()
+
 	return connection, nil
 }
 
@@ -105,16 +101,7 @@ func handler(conn *pt.SocksConn) error {
 	defer conn.Close()
 	log.Println("handler fired:", conn)
 
-	// TODO: [#3] Fetch ICE server information from Broker.
-	// TODO: [#18] Consider TURN servers here too.
-	config := webrtc.NewConfiguration(
-		webrtc.OptionIceServer("stun:stun.l.google.com:19302"))
-	broker := NewBrokerChannel(brokerURL, frontDomain)
-	if nil == broker {
-		conn.Reject()
-		return errors.New("Failed to prepare BrokerChannel")
-	}
-	remote, err := dialWebRTC(config, broker)
+	remote, err := dialWebRTC()
 	if err != nil {
 		conn.Reject()
 		return err
@@ -174,12 +161,12 @@ func readSignalingMessages(f *os.File) {
 }
 
 func main() {
-	var err error
+	// var err error
 	webrtc.SetLoggingVerbosity(1)
 	flag.StringVar(&brokerURL, "url", "", "URL of signaling broker")
 	flag.StringVar(&frontDomain, "front", "", "front domain")
 	flag.Parse()
-	logFile, err = os.OpenFile("snowflake.log", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
+	logFile, err := os.OpenFile("snowflake.log", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0600)
 	if err != nil {
 		log.Fatal(err)
 	}

client/webrtc.go

@@ -34,7 +34,7 @@ func (c *webRTCConn) Read(b []byte) (int, error) {
 }
 
 func (c *webRTCConn) Write(b []byte) (int, error) {
-	c.SendData(b)
+	c.sendData(b)
 	return len(b), nil
 }
 
@@ -63,7 +63,64 @@ func (c *webRTCConn) SetWriteDeadline(t time.Time) error {
 	return fmt.Errorf("SetWriteDeadline not implemented")
 }
 
-func (c *webRTCConn) PreparePeerConnection() {
+func NewWebRTCConnection(config *webrtc.Configuration,
+		broker *BrokerChannel) *webRTCConn {
+	connection := new(webRTCConn)
+	connection.config = config
+	connection.broker = broker
+	connection.offerChannel = make(chan *webrtc.SessionDescription)
+	connection.answerChannel = make(chan *webrtc.SessionDescription)
+	connection.writeChannel = make(chan []byte)
+	connection.errorChannel = make(chan error)
+	connection.reset = make(chan struct{})
+
+	// Log every few seconds.
+	connection.BytesInfo = &BytesInfo{
+		inboundChan: make(chan int), outboundChan: make(chan int),
+		inbound: 0, outbound: 0, inEvents: 0, outEvents: 0,
+	}
+	go connection.BytesInfo.Log()
+
+	// Pipes remain the same even when DataChannel gets switched.
+	connection.recvPipe, connection.writePipe = io.Pipe()
+
+	return connection
+}
+
+// WebRTC re-establishment loop. Expected in own goroutine.
+func (c *webRTCConn) ConnectLoop() {
+	for {
+		log.Println("Establishing WebRTC connection...")
+		// TODO: When go-webrtc is more stable, it's possible that a new
+		// PeerConnection won't need to be re-prepared each time.
+		c.preparePeerConnection()
+		err := c.establishDataChannel()
+		if err == nil {
+			c.sendOffer()
+			c.receiveAnswer()
+			<-c.reset
+			log.Println(" --- snowflake connection reset ---")
+		} else {
+			log.Println("WebRTC: Could not establish DataChannel.")
+		}
+	}
+}
+
+// Expected in own goroutine.
+func (c *webRTCConn) SendLoop() {
+	log.Println("send loop")
+	for data := range c.writeChannel {
+		// Flush buffer if necessary.
+		for c.buffer.Len() > 0 {
+			c.snowflake.Send(c.buffer.Bytes())
+			log.Println("Flushed", c.buffer.Len(), "bytes")
+			c.buffer.Reset()
+		}
+		c.snowflake.Send(data)
+	}
+}
+
+func (c *webRTCConn) preparePeerConnection() {
 	if nil != c.pc {
 		c.pc.Close()
 		c.pc = nil
@@ -110,7 +167,7 @@ func (c *webRTCConn) PreparePeerConnection() {
 }
 
 // Create a WebRTC DataChannel locally.
-func (c *webRTCConn) EstablishDataChannel() error {
+func (c *webRTCConn) establishDataChannel() error {
 	dc, err := c.pc.CreateDataChannel("snowflake", webrtc.Init{})
 	// Triggers "OnNegotiationNeeded" on the PeerConnection, which will prepare
 	// an SDP offer while other goroutines operating on this struct handle the
@@ -158,13 +215,14 @@ func (c *webRTCConn) EstablishDataChannel() error {
 
 // Block until an offer is available, then send it to either
 // the Broker or signal pipe.
-func (c *webRTCConn) SendOffer() error {
+func (c *webRTCConn) sendOffer() error {
+	log.Println("sendOffer...")
 	select {
 	case offer := <-c.offerChannel:
 		if "" == brokerURL {
 			log.Printf("Please Copy & Paste the following to the peer:")
 			log.Printf("----------------")
-			fmt.Fprintln(logFile, "\n"+offer.Serialize()+"\n")
+			log.Printf("\n" + offer.Serialize() + "\n")
 			log.Printf("----------------")
 			return nil
 		}
@@ -186,7 +244,7 @@ func (c *webRTCConn) SendOffer() error {
 	return nil
 }
 
-func (c *webRTCConn) ReceiveAnswer() {
+func (c *webRTCConn) receiveAnswer() {
 	go func() {
 		answer, ok := <-c.answerChannel
 		if !ok || nil == answer {
@@ -203,7 +261,7 @@ func (c *webRTCConn) ReceiveAnswer() {
 	}()
 }
 
-func (c *webRTCConn) SendData(data []byte) {
+func (c *webRTCConn) sendData(data []byte) {
 	c.BytesInfo.AddOutbound(len(data))
 	// Buffer the data in case datachannel isn't available yet.
 	if nil == c.snowflake {
@@ -214,39 +272,6 @@ func (c *webRTCConn) SendData(data []byte) {
 	c.writeChannel <- data
 }
 
-// Expected in own goroutine.
-func (c *webRTCConn) SendLoop() {
-	log.Println("send loop")
-	for data := range c.writeChannel {
-		// Flush buffer if necessary.
-		for c.buffer.Len() > 0 {
-			c.snowflake.Send(c.buffer.Bytes())
-			log.Println("Flushed", c.buffer.Len(), "bytes")
-			c.buffer.Reset()
-		}
-		c.snowflake.Send(data)
-	}
-}
-
-// WebRTC re-establishment loop. Expected in own goroutine.
-func (c *webRTCConn) ConnectLoop() {
-	for {
-		log.Println("Establishing WebRTC connection...")
-		// TODO: When go-webrtc is more stable, it's possible that a new
-		// PeerConnection won't need to be re-prepared each time.
-		c.PreparePeerConnection()
-		err := c.EstablishDataChannel()
-		if err == nil {
-			c.SendOffer()
-			c.ReceiveAnswer()
-			<-c.reset
-			log.Println(" --- snowflake connection reset ---")
-		} else {
-			log.Println("WebRTC: Could not establish DataChannel.")
-		}
-	}
-}
-
 func (c *webRTCConn) Reset() {
 	go func() {
 		c.reset <- struct{}{} // Attempt to negotiate a new datachannel..