mirror of
https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git
synced 2025-10-14 05:11:19 -04:00
move webRTCConn into separate file
This commit is contained in:
Serene Han
parent
ef5cb162c0
commit
f86f5b5b07
2 changed files with 255 additions and 247 deletions
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@ -3,10 +3,8 @@ package main
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import (
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"bufio"
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"bytes"
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"errors"
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"flag"
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"fmt"
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"io"
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"log"
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"net"
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@ -14,7 +12,6 @@ import (
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"os/signal"
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"sync"
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"syscall"
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"time"
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"git.torproject.org/pluggable-transports/goptlib.git"
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"github.com/keroserene/go-webrtc"
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@ -57,250 +54,6 @@ type SnowflakeChannel interface {
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Close() error
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}
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// Implements net.Conn interface
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type webRTCConn struct {
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config *webrtc.Configuration
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pc *webrtc.PeerConnection
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snowflake SnowflakeChannel // Interface holding the WebRTC DataChannel.
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broker *BrokerChannel
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offerChannel chan *webrtc.SessionDescription
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answerChannel chan *webrtc.SessionDescription
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errorChannel chan error
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writeChannel chan []byte
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recvPipe *io.PipeReader
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writePipe *io.PipeWriter
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buffer bytes.Buffer
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reset chan struct{}
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*BytesInfo
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}
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var webrtcRemote *webRTCConn
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func (c *webRTCConn) Read(b []byte) (int, error) {
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return c.recvPipe.Read(b)
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}
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func (c *webRTCConn) Write(b []byte) (int, error) {
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c.SendData(b)
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return len(b), nil
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}
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func (c *webRTCConn) Close() error {
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// Data channel closed implicitly?
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return c.pc.Close()
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}
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func (c *webRTCConn) LocalAddr() net.Addr {
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return nil
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}
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func (c *webRTCConn) RemoteAddr() net.Addr {
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return nil
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}
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func (c *webRTCConn) SetDeadline(t time.Time) error {
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return fmt.Errorf("SetDeadline not implemented")
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}
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func (c *webRTCConn) SetReadDeadline(t time.Time) error {
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return fmt.Errorf("SetReadDeadline not implemented")
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}
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func (c *webRTCConn) SetWriteDeadline(t time.Time) error {
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return fmt.Errorf("SetWriteDeadline not implemented")
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}
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func (c *webRTCConn) PreparePeerConnection() {
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if nil != c.pc {
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c.pc.Close()
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c.pc = nil
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}
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pc, err := webrtc.NewPeerConnection(c.config)
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if err != nil {
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log.Printf("NewPeerConnection: %s", err)
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c.errorChannel <- err
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}
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// Prepare PeerConnection callbacks.
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pc.OnNegotiationNeeded = func() {
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log.Println("WebRTC: OnNegotiationNeeded")
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go func() {
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offer, err := pc.CreateOffer()
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// TODO: Potentially timeout and retry if ICE isn't working.
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if err != nil {
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c.errorChannel <- err
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return
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}
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err = pc.SetLocalDescription(offer)
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if err != nil {
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c.errorChannel <- err
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return
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}
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}()
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}
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// Allow candidates to accumulate until OnIceComplete.
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pc.OnIceCandidate = func(candidate webrtc.IceCandidate) {
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log.Printf(candidate.Candidate)
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}
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// TODO: This may soon be deprecated, consider OnIceGatheringStateChange.
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pc.OnIceComplete = func() {
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log.Printf("WebRTC: OnIceComplete")
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c.offerChannel <- pc.LocalDescription()
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}
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// This callback is not expected, as the Client initiates the creation
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// of the data channel, not the remote peer.
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pc.OnDataChannel = func(channel *webrtc.DataChannel) {
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log.Println("OnDataChannel")
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panic("Unexpected OnDataChannel!")
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}
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c.pc = pc
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log.Println("WebRTC: PeerConnection created.")
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}
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// Create a WebRTC DataChannel locally.
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func (c *webRTCConn) EstablishDataChannel() error {
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dc, err := c.pc.CreateDataChannel("snowflake", webrtc.Init{})
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// Triggers "OnNegotiationNeeded" on the PeerConnection, which will prepare
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// an SDP offer while other goroutines operating on this struct handle the
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// signaling. Eventually fires "OnOpen".
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if err != nil {
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log.Printf("CreateDataChannel: %s", err)
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return err
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}
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dc.OnOpen = func() {
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log.Println("WebRTC: DataChannel.OnOpen")
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if nil != c.snowflake {
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panic("PeerConnection snowflake already exists.")
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}
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// Flush the buffer, then enable datachannel.
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dc.Send(c.buffer.Bytes())
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log.Println("Flushed", c.buffer.Len(), "bytes")
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c.buffer.Reset()
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c.snowflake = dc
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}
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dc.OnClose = func() {
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// Disable the DataChannel as a write destination.
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// Future writes will go to the buffer until a new DataChannel is available.
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log.Println("WebRTC: DataChannel.OnClose")
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// Only reset if this OnClose was triggered remotely.
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if nil != c.snowflake {
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c.snowflake = nil
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c.Reset()
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}
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}
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dc.OnMessage = func(msg []byte) {
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c.BytesInfo.AddInbound(len(msg))
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n, err := c.writePipe.Write(msg)
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if err != nil {
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// TODO: Maybe shouldn't actually close.
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log.Println("Error writing to SOCKS pipe")
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c.writePipe.CloseWithError(err)
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}
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if n != len(msg) {
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panic("short write")
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}
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}
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log.Println("WebRTC: DataChannel created.")
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return nil
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}
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// Block until an offer is available, then send it to either
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// the Broker or signal pipe.
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func (c *webRTCConn) SendOffer() error {
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select {
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case offer := <-c.offerChannel:
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if "" == brokerURL {
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log.Printf("Please Copy & Paste the following to the peer:")
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log.Printf("----------------")
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fmt.Fprintln(logFile, "\n"+offer.Serialize()+"\n")
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log.Printf("----------------")
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return nil
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}
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// Otherwise, use Broker.
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go func() {
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log.Println("Sending offer via BrokerChannel...\nTarget URL: ", brokerURL,
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"\nFront URL: ", frontDomain)
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answer, err := c.broker.Negotiate(c.pc.LocalDescription())
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if nil != err || nil == answer {
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log.Printf("BrokerChannel error: %s", err)
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answer = nil
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}
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c.answerChannel <- answer
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}()
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case err := <-c.errorChannel:
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c.pc.Close()
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return err
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}
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return nil
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}
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func (c *webRTCConn) ReceiveAnswer() {
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go func() {
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answer, ok := <-c.answerChannel
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if !ok || nil == answer {
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log.Printf("Failed to retrieve answer. Retrying in %d seconds", ReconnectTimeout)
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<-time.After(time.Second * ReconnectTimeout)
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c.Reset()
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return
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}
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log.Printf("Received Answer:\n\n%s\n", answer.Sdp)
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err := c.pc.SetRemoteDescription(answer)
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if nil != err {
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c.errorChannel <- err
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}
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}()
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}
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func (c *webRTCConn) SendData(data []byte) {
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c.BytesInfo.AddOutbound(len(data))
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// Buffer the data in case datachannel isn't available yet.
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if nil == c.snowflake {
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log.Printf("Buffered %d bytes --> WebRTC", len(data))
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c.buffer.Write(data)
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return
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}
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c.writeChannel <- data
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}
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// Expected in own goroutine.
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func (c *webRTCConn) SendLoop() {
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log.Println("send loop")
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for data := range c.writeChannel {
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// Flush buffer if necessary.
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for c.buffer.Len() > 0 {
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c.snowflake.Send(c.buffer.Bytes())
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log.Println("Flushed", c.buffer.Len(), "bytes")
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c.buffer.Reset()
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}
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c.snowflake.Send(data)
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}
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}
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// WebRTC re-establishment loop. Expected in own goroutine.
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func (c *webRTCConn) ConnectLoop() {
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for {
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log.Println("Establishing WebRTC connection...")
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// TODO: When go-webrtc is more stable, it's possible that a new
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// PeerConnection won't need to be re-prepared each time.
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c.PreparePeerConnection()
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err := c.EstablishDataChannel()
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if err == nil {
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c.SendOffer()
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c.ReceiveAnswer()
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<-c.reset
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log.Println(" --- snowflake connection reset ---")
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} else {
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log.Println("WebRTC: Could not establish DataChannel.")
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}
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}
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}
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func (c *webRTCConn) Reset() {
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go func() {
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c.reset <- struct{}{} // Attempt to negotiate a new datachannel..
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log.Println("WebRTC resetting...")
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}()
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}
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// Initialize a WebRTC Connection.
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func dialWebRTC(config *webrtc.Configuration, broker *BrokerChannel) (
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*webRTCConn, error) {
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255
client/webrtc.go
Normal file
255
client/webrtc.go
Normal file
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@ -0,0 +1,255 @@
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package main
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import (
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"bytes"
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"fmt"
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"github.com/keroserene/go-webrtc"
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"io"
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"log"
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"net"
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"time"
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)
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// Implements net.Conn interface
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type webRTCConn struct {
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config *webrtc.Configuration
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pc *webrtc.PeerConnection
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snowflake SnowflakeChannel // Interface holding the WebRTC DataChannel.
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broker *BrokerChannel
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offerChannel chan *webrtc.SessionDescription
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answerChannel chan *webrtc.SessionDescription
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errorChannel chan error
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writeChannel chan []byte
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recvPipe *io.PipeReader
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writePipe *io.PipeWriter
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buffer bytes.Buffer
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reset chan struct{}
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*BytesInfo
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}
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var webrtcRemote *webRTCConn
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func (c *webRTCConn) Read(b []byte) (int, error) {
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return c.recvPipe.Read(b)
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}
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func (c *webRTCConn) Write(b []byte) (int, error) {
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c.SendData(b)
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return len(b), nil
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}
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func (c *webRTCConn) Close() error {
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// Data channel closed implicitly?
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return c.pc.Close()
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}
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func (c *webRTCConn) LocalAddr() net.Addr {
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return nil
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}
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func (c *webRTCConn) RemoteAddr() net.Addr {
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return nil
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}
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func (c *webRTCConn) SetDeadline(t time.Time) error {
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return fmt.Errorf("SetDeadline not implemented")
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}
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func (c *webRTCConn) SetReadDeadline(t time.Time) error {
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return fmt.Errorf("SetReadDeadline not implemented")
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}
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func (c *webRTCConn) SetWriteDeadline(t time.Time) error {
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return fmt.Errorf("SetWriteDeadline not implemented")
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}
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func (c *webRTCConn) PreparePeerConnection() {
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if nil != c.pc {
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c.pc.Close()
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c.pc = nil
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}
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pc, err := webrtc.NewPeerConnection(c.config)
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if err != nil {
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log.Printf("NewPeerConnection: %s", err)
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c.errorChannel <- err
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}
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// Prepare PeerConnection callbacks.
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pc.OnNegotiationNeeded = func() {
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log.Println("WebRTC: OnNegotiationNeeded")
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go func() {
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offer, err := pc.CreateOffer()
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// TODO: Potentially timeout and retry if ICE isn't working.
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if err != nil {
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c.errorChannel <- err
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return
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}
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err = pc.SetLocalDescription(offer)
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if err != nil {
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c.errorChannel <- err
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return
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}
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}()
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}
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// Allow candidates to accumulate until OnIceComplete.
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pc.OnIceCandidate = func(candidate webrtc.IceCandidate) {
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log.Printf(candidate.Candidate)
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}
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// TODO: This may soon be deprecated, consider OnIceGatheringStateChange.
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pc.OnIceComplete = func() {
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log.Printf("WebRTC: OnIceComplete")
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c.offerChannel <- pc.LocalDescription()
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}
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// This callback is not expected, as the Client initiates the creation
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// of the data channel, not the remote peer.
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pc.OnDataChannel = func(channel *webrtc.DataChannel) {
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log.Println("OnDataChannel")
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panic("Unexpected OnDataChannel!")
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}
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c.pc = pc
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log.Println("WebRTC: PeerConnection created.")
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}
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// Create a WebRTC DataChannel locally.
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func (c *webRTCConn) EstablishDataChannel() error {
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dc, err := c.pc.CreateDataChannel("snowflake", webrtc.Init{})
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// Triggers "OnNegotiationNeeded" on the PeerConnection, which will prepare
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// an SDP offer while other goroutines operating on this struct handle the
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// signaling. Eventually fires "OnOpen".
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if err != nil {
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log.Printf("CreateDataChannel: %s", err)
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return err
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}
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dc.OnOpen = func() {
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log.Println("WebRTC: DataChannel.OnOpen")
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if nil != c.snowflake {
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panic("PeerConnection snowflake already exists.")
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}
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// Flush the buffer, then enable datachannel.
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dc.Send(c.buffer.Bytes())
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log.Println("Flushed", c.buffer.Len(), "bytes")
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c.buffer.Reset()
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c.snowflake = dc
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}
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dc.OnClose = func() {
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// Disable the DataChannel as a write destination.
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// Future writes will go to the buffer until a new DataChannel is available.
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log.Println("WebRTC: DataChannel.OnClose")
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// Only reset if this OnClose was triggered remotely.
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if nil != c.snowflake {
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c.snowflake = nil
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c.Reset()
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}
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}
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dc.OnMessage = func(msg []byte) {
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c.BytesInfo.AddInbound(len(msg))
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n, err := c.writePipe.Write(msg)
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if err != nil {
|
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// TODO: Maybe shouldn't actually close.
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log.Println("Error writing to SOCKS pipe")
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c.writePipe.CloseWithError(err)
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}
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if n != len(msg) {
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panic("short write")
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}
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}
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log.Println("WebRTC: DataChannel created.")
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return nil
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}
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// Block until an offer is available, then send it to either
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// the Broker or signal pipe.
|
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func (c *webRTCConn) SendOffer() error {
|
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select {
|
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case offer := <-c.offerChannel:
|
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if "" == brokerURL {
|
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log.Printf("Please Copy & Paste the following to the peer:")
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log.Printf("----------------")
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fmt.Fprintln(logFile, "\n"+offer.Serialize()+"\n")
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log.Printf("----------------")
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return nil
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}
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// Otherwise, use Broker.
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go func() {
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log.Println("Sending offer via BrokerChannel...\nTarget URL: ", brokerURL,
|
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"\nFront URL: ", frontDomain)
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answer, err := c.broker.Negotiate(c.pc.LocalDescription())
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if nil != err || nil == answer {
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log.Printf("BrokerChannel error: %s", err)
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answer = nil
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}
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c.answerChannel <- answer
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}()
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case err := <-c.errorChannel:
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c.pc.Close()
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return err
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}
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return nil
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}
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|
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func (c *webRTCConn) ReceiveAnswer() {
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go func() {
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answer, ok := <-c.answerChannel
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if !ok || nil == answer {
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log.Printf("Failed to retrieve answer. Retrying in %d seconds", ReconnectTimeout)
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<-time.After(time.Second * ReconnectTimeout)
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c.Reset()
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return
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}
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log.Printf("Received Answer:\n\n%s\n", answer.Sdp)
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err := c.pc.SetRemoteDescription(answer)
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if nil != err {
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c.errorChannel <- err
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}
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}()
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}
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|
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func (c *webRTCConn) SendData(data []byte) {
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c.BytesInfo.AddOutbound(len(data))
|
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// Buffer the data in case datachannel isn't available yet.
|
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if nil == c.snowflake {
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log.Printf("Buffered %d bytes --> WebRTC", len(data))
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c.buffer.Write(data)
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return
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}
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c.writeChannel <- data
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}
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// Expected in own goroutine.
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func (c *webRTCConn) SendLoop() {
|
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log.Println("send loop")
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for data := range c.writeChannel {
|
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// Flush buffer if necessary.
|
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for c.buffer.Len() > 0 {
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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..
|
||||
log.Println("WebRTC resetting...")
|
||||
}()
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue