commit 5a7fa6ef4b2593531188f043421ec48f731b1a04 Author: David Fifield david@bamsoftware.com Date: Thu May 30 14:27:30 2013 -0700
Resurrect websocket-client. --- .gitignore | 1 + websocket-transport/Makefile | 3 +- websocket-transport/websocket-client.go | 220 +++++++++++++++++++++++++++++++ 3 files changed, 223 insertions(+), 1 deletion(-)
diff --git a/.gitignore b/.gitignore index b8833f8..cc97752 100644 --- a/.gitignore +++ b/.gitignore @@ -1,4 +1,5 @@ *.pyc /dist /py2exe-tmp +/websocket-transport/websocket-client /websocket-transport/websocket-server diff --git a/websocket-transport/Makefile b/websocket-transport/Makefile index 5cdba65..ac6fa08 100644 --- a/websocket-transport/Makefile +++ b/websocket-transport/Makefile @@ -1,7 +1,7 @@ PREFIX = /usr/local BINDIR = $(PREFIX)/bin
-PROGRAMS = websocket-server +PROGRAMS = websocket-client websocket-server
GOBUILDFLAGS = # Alternate flags to use gccgo, allowing cross-compiling for x86 from @@ -11,6 +11,7 @@ GOBUILDFLAGS =
all: websocket-server
+websocket-client: websocket-client.go socks.go pt.go websocket-server: websocket-server.go pt.go websocket.go
%: %.go diff --git a/websocket-transport/websocket-client.go b/websocket-transport/websocket-client.go new file mode 100644 index 0000000..129e90a --- /dev/null +++ b/websocket-transport/websocket-client.go @@ -0,0 +1,220 @@ +// Tor websocket client transport plugin. +// +// Usage: +// ClientTransportPlugin websocket exec ./websocket-client + +package main + +import ( + "code.google.com/p/go.net/websocket" + "flag" + "fmt" + "io" + "net" + "net/url" + "os" + "os/signal" + "sync" + "time" +) + +const socksTimeout = 2 +const bufSiz = 1500 + +// When a connection handler starts, +1 is written to this channel; when it +// ends, -1 is written. +var handlerChan = make(chan int) + +func logDebug(format string, v ...interface{}) { + fmt.Fprintf(os.Stderr, format+"\n", v...) +} + +func proxy(local *net.TCPConn, ws *websocket.Conn) { + var wg sync.WaitGroup + + wg.Add(2) + + // Local-to-WebSocket read loop. + go func() { + buf := make([]byte, bufSiz) + var err error + for { + n, er := local.Read(buf[:]) + if n > 0 { + ew := websocket.Message.Send(ws, buf[:n]) + if ew != nil { + err = ew + break + } + } + if er != nil { + err = er + break + } + } + if err != nil && err != io.EOF { + logDebug("%s", err) + } + local.CloseRead() + ws.Close() + + wg.Done() + }() + + // WebSocket-to-local read loop. + go func() { + var buf []byte + var err error + for { + er := websocket.Message.Receive(ws, &buf) + if er != nil { + err = er + break + } + n, ew := local.Write(buf) + if ew != nil { + err = ew + break + } + if n != len(buf) { + err = io.ErrShortWrite + break + } + } + if err != nil && err != io.EOF { + logDebug("%s", err) + } + local.CloseWrite() + ws.Close() + + wg.Done() + }() + + wg.Wait() +} + +func handleConnection(conn *net.TCPConn) error { + defer conn.Close() + + handlerChan <- 1 + defer func() { + handlerChan <- -1 + }() + + var ws *websocket.Conn + + conn.SetDeadline(time.Now().Add(socksTimeout * time.Second)) + err := AwaitSocks4aConnect(conn, func(dest string) (*net.TCPAddr, error) { + // Disable deadline. + conn.SetDeadline(time.Time{}) + logDebug("SOCKS request for %s", dest) + destAddr, err := net.ResolveTCPAddr("tcp", dest) + if err != nil { + return nil, err + } + wsUrl := url.URL{Scheme: "ws", Host: dest} + ws, err = websocket.Dial(wsUrl.String(), "", wsUrl.String()) + if err != nil { + return nil, err + } + logDebug("WebSocket connection to %s", ws.Config().Location.String()) + return destAddr, nil + }) + if err != nil { + return err + } + defer ws.Close() + proxy(conn, ws) + return nil +} + +func socksAcceptLoop(ln *net.TCPListener) error { + for { + socks, err := ln.AcceptTCP() + if err != nil { + return err + } + go func() { + err := handleConnection(socks) + if err != nil { + logDebug("SOCKS from %s: %s", socks.RemoteAddr(), err) + } + }() + } + return nil +} + +func startListener(addrStr string) (*net.TCPListener, error) { + addr, err := net.ResolveTCPAddr("tcp", addrStr) + if err != nil { + return nil, err + } + ln, err := net.ListenTCP("tcp", addr) + if err != nil { + return nil, err + } + go func() { + err := socksAcceptLoop(ln) + if err != nil { + logDebug("accept: %s", err) + } + }() + return ln, nil +} + +func main() { + const ptMethodName = "websocket" + var defaultSocksAddrStrs = []string{"127.0.0.1:0"} + var socksAddrStrs []string + + var socksArg = flag.String("socks", "", "address on which to listen for SOCKS connections") + flag.Parse() + if *socksArg != "" { + socksAddrStrs = []string{*socksArg} + } else { + socksAddrStrs = defaultSocksAddrStrs + } + + PtClientSetup([]string{ptMethodName}) + + listeners := make([]*net.TCPListener, 0) + for _, socksAddrStr := range socksAddrStrs { + ln, err := startListener(socksAddrStr) + if err != nil { + PtCmethodError(ptMethodName, err.Error()) + } + PtCmethod(ptMethodName, "socks4", ln.Addr()) + listeners = append(listeners, ln) + } + PtCmethodsDone() + + var numHandlers int = 0 + + signalChan := make(chan os.Signal, 1) + signal.Notify(signalChan, os.Interrupt) + var sigint bool = false + for !sigint { + select { + case n := <-handlerChan: + numHandlers += n + case <-signalChan: + logDebug("SIGINT") + sigint = true + } + } + + for _, ln := range listeners { + ln.Close() + } + + sigint = false + for numHandlers != 0 && !sigint { + select { + case n := <-handlerChan: + numHandlers += n + case <-signalChan: + logDebug("SIGINT") + sigint = true + } + } +}