archives/snowflake
2
0
Fork 0
mirror of https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git synced 2025-10-13 20:11:19 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Use a channel to safely synchronize datachannel writes, (#12)

Browse source 
clean up ice candidate log message.
still need to debug the copy loop break.
This commit is contained in:
Serene Han 2016-02-19 16:17:17 -08:00
parent c4215b5614
commit c3ada1b545
2 changed files with 47 additions and 18 deletions
Download patch file Download diff file Expand all files Collapse all files

54
client/snowflake.go
View file

@ -36,12 +36,15 @@ const (
func copyLoop(a, b net.Conn) {
var wg sync.WaitGroup
wg.Add(2)
// TODO fix the copy loop.
go func() {
io.Copy(b, a)
log.Println("copy loop b-a break")
wg.Done()
}()
go func() {
io.Copy(a, b)
log.Println("copy loop a-b break")
wg.Done()
}()
wg.Wait()
@ -63,6 +66,7 @@ type webRTCConn struct {
offerChannel chan *webrtc.SessionDescription
answerChannel chan *webrtc.SessionDescription
errorChannel chan error
writeChannel chan []byte
recvPipe *io.PipeReader
writePipe *io.PipeWriter
buffer bytes.Buffer
@ -77,7 +81,7 @@ 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
}
@ -133,9 +137,9 @@ func (c *webRTCConn) PreparePeerConnection() {
}
}()
}
// Allow candidates to accumulate until OnIceComplete.
pc.OnIceCandidate = func(candidate webrtc.IceCandidate) {
log.Printf("WebRTC: OnIceCandidate %s", candidate.Serialize())
// Allow candidates to accumulate until OnIceComplete.
log.Printf(candidate.Candidate)
}
// TODO: This may soon be deprecated, consider OnIceGatheringStateChange.
pc.OnIceComplete = func() {
@ -169,10 +173,11 @@ func (c *webRTCConn) EstablishDataChannel() error {
// }
// Flush the buffer, then enable datachannel.
// TODO: Make this more safe
dc.Send(c.buffer.Bytes())
log.Println("Flushed", c.buffer.Len(), "bytes")
c.buffer.Reset()
// dc.Send(c.buffer.Bytes())
// log.Println("Flushed", c.buffer.Len(), "bytes")
// c.buffer.Reset()
c.snowflake = dc
c.SendData(nil)
}
dc.OnClose = func() {
// Disable the DataChannel as a write destination.
@ -180,7 +185,7 @@ func (c *webRTCConn) EstablishDataChannel() error {
log.Println("WebRTC: DataChannel.OnClose")
if nil != c.snowflake {
c.snowflake = nil
// Only reset if this OnClose triggered
// Only reset if this OnClose was triggered remotely.
c.Reset()
}
}
@ -247,21 +252,32 @@ func (c *webRTCConn) ReceiveAnswer() {
}()
}
func (c *webRTCConn) sendData(data []byte) {
c.BytesInfo.AddOutbound(len(data))
func (c *webRTCConn) SendData(data []byte) {
// Buffer the data in case datachannel isn't available yet.
if nil == c.snowflake {
log.Printf("Buffered %d bytes --> WebRTC", len(data))
c.buffer.Write(data)
return
}
// Otherwise, 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()
go func() {
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.BytesInfo.AddOutbound(len(data))
c.snowflake.Send(data)
}
c.snowflake.Send(data)
}
// WebRTC re-establishment loop. Expected in own goroutine.
@ -296,6 +312,7 @@ func dialWebRTC(config *webrtc.Configuration, broker *BrokerChannel) (
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{
@ -308,6 +325,7 @@ func dialWebRTC(config *webrtc.Configuration, broker *BrokerChannel) (
connection.recvPipe, connection.writePipe = io.Pipe()
go connection.ConnectLoop()
go connection.SendLoop()
return connection, nil
}
@ -317,8 +335,10 @@ func endWebRTC() {
return
}
if nil != webrtcRemote.snowflake {
s := webrtcRemote.snowflake
webrtcRemote.snowflake = nil
log.Printf("WebRTC: closing DataChannel")
webrtcRemote.snowflake.Close()
s.Close()
}
if nil != webrtcRemote.pc {
log.Printf("WebRTC: closing PeerConnection")
@ -333,6 +353,7 @@ func handler(conn *pt.SocksConn) error {
handlerChan <- -1
}()
defer conn.Close()
log.Println("handler", conn)
// TODO: [#3] Fetch ICE server information from Broker.
// TODO: [#18] Consider TURN servers here too.
@ -357,6 +378,7 @@ func handler(conn *pt.SocksConn) error {
}
copyLoop(conn, remote)
log.Println("----END---")
return nil
}