January 2013 - tor-commits - lists.torproject.org

[flashproxy/master] I think --port should always override tor's requested port.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit c47f7674117b878e7f35b28e64698373f74974dd Author: David Fifield <david(a)bamsoftware.com> Date: Sun Dec 2 18:37:02 2012 -0800 I think --port should always override tor's requested port. --- websocket-transport/websocket-server.go | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/websocket-transport/websocket-server.go b/websocket-transport/websocket-server.go index ea13c1e..725053c 100644 --- a/websocket-transport/websocket-server.go +++ b/websocket-transport/websocket-server.go @@ -187,9 +187,10 @@ func main() { listeners := make([]*net.TCPListener, 0) for _, bindAddr := range ptInfo.BindAddrs { - // When tor tells us a port of 0, we are supposed to pick a - // random port. But we actually want to use the configured port. - if bindAddr.Addr.Port == 0 { + // Override tor's requested port (which is 0 if this transport + // has not been run before) with the one requested by the --port + // option. + if defaultPort != 0 { bindAddr.Addr.Port = defaultPort }

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[flashproxy/master] Comment typo.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit 533b03757113d01ddc9f55b32000d8a556ce1522 Author: David Fifield <david(a)bamsoftware.com> Date: Wed Dec 19 11:16:18 2012 -0800 Comment typo. --- websocket-transport/pt.go | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/websocket-transport/pt.go b/websocket-transport/pt.go index ffc475e..c43bf90 100644 --- a/websocket-transport/pt.go +++ b/websocket-transport/pt.go @@ -2,7 +2,7 @@ // // Sample client usage: // -// PtClientSetup([]string{"foo"} +// PtClientSetup([]string{"foo"}) // ln, err := startSocksListener() // if err != nil { // panic(err.Error())

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[flashproxy/master] Remove websocket-client.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit 6ad919a95c0a54d318d660c8fe71f054680a0b4f Author: David Fifield <david(a)bamsoftware.com> Date: Mon Jan 28 01:49:27 2013 -0800 Remove websocket-client. Go's kinda built-in WebSocket support is lame. I'm afraid it's going to crash if you feed it a giant message. websocket-client has nothing to do with flash proxy per se; it just happens to be able to connect to the same bridges that flash proxies connect to. --- .gitignore | 1 - websocket-transport/Makefile | 3 +- websocket-transport/websocket-client.go | 220 ------------------------------- 3 files changed, 1 insertions(+), 223 deletions(-) diff --git a/.gitignore b/.gitignore index ff6ddd5..3edea77 100644 --- a/.gitignore +++ b/.gitignore @@ -1,5 +1,4 @@ /facilitator.log *.pyc /dist -/websocket-transport/websocket-client /websocket-transport/websocket-server diff --git a/websocket-transport/Makefile b/websocket-transport/Makefile index ac6fa08..5cdba65 100644 --- a/websocket-transport/Makefile +++ b/websocket-transport/Makefile @@ -1,7 +1,7 @@ PREFIX = /usr/local BINDIR = $(PREFIX)/bin -PROGRAMS = websocket-client websocket-server +PROGRAMS = websocket-server GOBUILDFLAGS = # Alternate flags to use gccgo, allowing cross-compiling for x86 from @@ -11,7 +11,6 @@ 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 deleted file mode 100644 index 129e90a..0000000 --- a/websocket-transport/websocket-client.go +++ /dev/null @@ -1,220 +0,0 @@ -// 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 - } - } -}

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[flashproxy/master] Update README to say that --port overrides.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit 32cf416b28cea81fa63f1fb4b5b82159a662953d Author: David Fifield <david(a)bamsoftware.com> Date: Mon Jan 28 01:57:32 2013 -0800 Update README to say that --port overrides. --- README | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/README b/README index 7bc56fa..e7f64ce 100644 --- a/README +++ b/README @@ -106,9 +106,7 @@ for the Go programming language ("apt-get install golang" on Debian). $ make # make install Add a line like the following to the relay's torrc. You can change the ---port option; make sure that port is open in the firewall. The --port -option doesn't have an effect if Tor has previously started the -transport under a different port. +--port option; make sure that port is open in the firewall. ServerTransportPlugin websocket exec /usr/local/bin/websocket-transport --port 9901 == How to put a flash proxy badge on a web page

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[flashproxy/master] Merge branch 'transport'
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit 8e76ecea674f39f8bbe83b58965feaaaee07e9ea Merge: 7d5f6f1 fee9038 Author: David Fifield <david(a)bamsoftware.com> Date: Mon Jan 28 02:06:37 2013 -0800 Merge branch 'transport' Managed WebSocket server transport. .gitignore | 1 + README | 27 +-- init.d/websockify | 62 ----- patches/websockify-binary-default.patch | 40 --- websocket-transport/Makefile | 29 ++ websocket-transport/pt.go | 293 +++++++++++++++++++++ websocket-transport/socks.go | 107 ++++++++ websocket-transport/websocket-server.go | 235 +++++++++++++++++ websocket-transport/websocket.go | 429 +++++++++++++++++++++++++++++++ 9 files changed, 1103 insertions(+), 120 deletions(-) diff --cc .gitignore index 4ee6b0c,3edea77..41e7192 --- a/.gitignore +++ b/.gitignore @@@ -1,3 -1,4 +1,4 @@@ -/facilitator.log *.pyc /dist +/pyinstaller-tmp + /websocket-transport/websocket-server

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[flashproxy/master] Move websocket lib bug URLs to websocket.go.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit fee9038c3f0903760900118c215b79e8a84bebbc Author: David Fifield <david(a)bamsoftware.com> Date: Mon Jan 28 02:02:57 2013 -0800 Move websocket lib bug URLs to websocket.go. --- websocket-transport/README | 19 ------------------- websocket-transport/websocket.go | 14 ++++++++++++++ 2 files changed, 14 insertions(+), 19 deletions(-) diff --git a/websocket-transport/README b/websocket-transport/README deleted file mode 100644 index fedde17..0000000 --- a/websocket-transport/README +++ /dev/null @@ -1,19 +0,0 @@ -ClientTransportPlugin websocket exec ./websocket-client -Bridge websocket tor1.bamsoftware.com:9901 -UseBridges 1 - -ServerTransportPlugin websocket exec ./websocket-server - -"Denial of Service Protection in Go HTTP Servers" -https://code.google.com/p/go/issues/detail?id=2093 - -"go.websocket: Read/Copy fail with long frames" -https://code.google.com/p/go/issues/detail?id=2134 - -http://golang.org/pkg/net/textproto/#pkg-bugs -"To let callers manage exposure to denial of service attacks, Reader -should allow them to set and reset a limit on the number of bytes read -from the connection." - -"websocket.Dial doesn't limit response header length as http.Get does" -https://groups.google.com/forum/?fromgroups=#!topic/golang-nuts/2Tge6U8-QYI diff --git a/websocket-transport/websocket.go b/websocket-transport/websocket.go index 70bd67d..0e66405 100644 --- a/websocket-transport/websocket.go +++ b/websocket-transport/websocket.go @@ -4,6 +4,20 @@ // to partially read a frame. WebsocketConfig.MaxMessageSize affords control of // the maximum buffering of messages. // +// The reason for using this custom implementation instead of +// code.google.com/p/go.net/websocket is that the latter has problems with long +// messages and does not support server subprotocols. +// "Denial of Service Protection in Go HTTP Servers" +// https://code.google.com/p/go/issues/detail?id=2093 +// "go.websocket: Read/Copy fail with long frames" +// https://code.google.com/p/go/issues/detail?id=2134 +// http://golang.org/pkg/net/textproto/#pkg-bugs +// "To let callers manage exposure to denial of service attacks, Reader should +// allow them to set and reset a limit on the number of bytes read from the +// connection." +// "websocket.Dial doesn't limit response header length as http.Get does" +// https://groups.google.com/forum/?fromgroups=#!topic/golang-nuts/2Tge6U8-QYI +// // Example usage: // // func doSomething(ws *Websocket) {

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[flashproxy/master] Do the proper thing on first and second SIGINT.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit c3c5c05d581291df9567d8d85c861155193be113 Author: David Fifield <david(a)bamsoftware.com> Date: Sun Nov 11 19:28:09 2012 -0800 Do the proper thing on first and second SIGINT. --- websocket-transport/websocket-client.go | 39 ++++++++++++++++++++++++++++++- 1 files changed, 38 insertions(+), 1 deletions(-) diff --git a/websocket-transport/websocket-client.go b/websocket-transport/websocket-client.go index ca551dd..6cce020 100644 --- a/websocket-transport/websocket-client.go +++ b/websocket-transport/websocket-client.go @@ -14,6 +14,10 @@ import ( 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...) } @@ -94,6 +98,11 @@ func proxy(local *net.TCPConn, ws *websocket.Conn) { func handleConnection(conn *net.TCPConn) error { defer conn.Close() + handlerChan <- 1 + defer func() { + handlerChan <- -1 + }() + conn.SetDeadline(time.Now().Add(socksTimeout * time.Second)) dest, err := readSocks4aConnect(conn) if err != nil { @@ -167,16 +176,44 @@ func main() { 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) - <-signalChan + 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 + } + } }

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[flashproxy/master] Add minimal websocket-client README.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit d3e37012b25eb84b6f0577fbb4037880ed669ef5 Author: David Fifield <david(a)bamsoftware.com> Date: Sun Nov 11 19:01:57 2012 -0800 Add minimal websocket-client README. --- websocket-transport/README | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/websocket-transport/README b/websocket-transport/README new file mode 100644 index 0000000..2cb9b85 --- /dev/null +++ b/websocket-transport/README @@ -0,0 +1,3 @@ +ClientTransportPlugin websocket exec ./websocket-client +Bridge websocket tor1.bamsoftware.com:9901 +UseBridges 1

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[flashproxy/master] Do an explicit wait for SIGINT.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit 95e7b9e8bb8615bdfde05c115b64f173f505b810 Author: David Fifield <david(a)bamsoftware.com> Date: Sun Nov 11 19:17:25 2012 -0800 Do an explicit wait for SIGINT. --- websocket-transport/websocket-client.go | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/websocket-transport/websocket-client.go b/websocket-transport/websocket-client.go index f8ae8ef..ca551dd 100644 --- a/websocket-transport/websocket-client.go +++ b/websocket-transport/websocket-client.go @@ -7,6 +7,7 @@ import ( "net" "net/url" "os" + "os/signal" "time" ) @@ -175,5 +176,7 @@ func main() { } ptCmethodsDone() - select {} + signalChan := make(chan os.Signal, 1) + signal.Notify(signalChan, os.Interrupt) + <-signalChan }

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[flashproxy/master] First draft of websocket-client.
by dcf＠torproject.org 30 Jan '13

30 Jan '13

commit fb2697bca0b99bc4771c9b4111f654733ba7f903 Author: David Fifield <david(a)bamsoftware.com> Date: Sat Nov 10 21:32:01 2012 -0800 First draft of websocket-client. --- .gitignore | 1 + websocket-transport/Makefile | 16 ++++ websocket-transport/pt.go | 106 +++++++++++++++++++++++++++ websocket-transport/socks.go | 82 +++++++++++++++++++++ websocket-transport/websocket-client.go | 120 +++++++++++++++++++++++++++++++ 5 files changed, 325 insertions(+), 0 deletions(-) diff --git a/.gitignore b/.gitignore index 493cc74..24f143b 100644 --- a/.gitignore +++ b/.gitignore @@ -1,3 +1,4 @@ /facilitator.log *.pyc /dist +/websocket-transport/websocket-client diff --git a/websocket-transport/Makefile b/websocket-transport/Makefile new file mode 100644 index 0000000..14ffac0 --- /dev/null +++ b/websocket-transport/Makefile @@ -0,0 +1,16 @@ +PROGRAMS = websocket-client + +all: $(PROGRAMS) + +websocket-client: websocket-client.go socks.go pt.go + +%: %.go + go build -o $@ $^ + +clean: + rm -f $(PROGRAMS) + +fmt: + go fmt + +.PHONY: all clean fmt diff --git a/websocket-transport/pt.go b/websocket-transport/pt.go new file mode 100644 index 0000000..9eaed84 --- /dev/null +++ b/websocket-transport/pt.go @@ -0,0 +1,106 @@ +package main + +import ( + "bytes" + "fmt" + "net" + "os" + "strings" +) + +// Escape a string so it contains no byte values over 127 and doesn't contain +// any of the characters '\x00', '\n', or '\\'. +func escape(s string) string { + var buf bytes.Buffer + for _, b := range []byte(s) { + if b == '\n' { + buf.WriteString("\\n") + } else if b == '\\' { + buf.WriteString("\\\\") + } else if 0 < b && b < 128 { + buf.WriteByte(b) + } else { + fmt.Fprintf(&buf, "\\x%02x", b) + } + } + return buf.String() +} + +func ptLine(keyword string, v ...string) { + var buf bytes.Buffer + buf.WriteString(keyword) + for _, x := range v { + buf.WriteString(" " + escape(x)) + } + fmt.Println(buf.String()) +} + +func ptEnvError(msg string) { + ptLine("ENV-ERROR", msg) + os.Exit(1) +} + +func ptVersionError(msg string) { + ptLine("VERSION-ERROR", msg) + os.Exit(1) +} + +func ptCmethodError(methodName, msg string) { + ptLine("CMETHOD-ERROR", methodName, msg) + os.Exit(1) +} + +func ptGetManagedTransportVer() string { + const transportVersion = "1" + for _, offered := range strings.Split(os.Getenv("TOR_PT_MANAGED_TRANSPORT_VER"), ",") { + if offered == transportVersion { + return offered + } + } + return "" +} + +func ptGetClientTransports(supported []string) []string { + clientTransports := os.Getenv("TOR_PT_CLIENT_TRANSPORTS") + if clientTransports == "" { + ptEnvError("no TOR_PT_CLIENT_TRANSPORTS environment variable") + } + if clientTransports == "*" { + return supported + } + + result := make([]string, 0) + for _, requested := range strings.Split(clientTransports, ",") { + for _, methodName := range supported { + if requested == methodName { + result = append(result, methodName) + } + } + } + return result +} + +func ptCmethod(name string, socks string, addr net.Addr) { + ptLine("CMETHOD", name, socks, addr.String()) +} + +func ptCmethodsDone() { + ptLine("CMETHODS", "DONE") +} + +func ptClientSetup(methodNames []string) []string { + ver := ptGetManagedTransportVer() + if ver == "" { + ptVersionError("no-version") + } else { + ptLine("VERSION", ver) + } + + methods := ptGetClientTransports(methodNames) + if len(methods) == 0 { + ptCmethodsDone() + os.Exit(1) + } + + return methods +} diff --git a/websocket-transport/socks.go b/websocket-transport/socks.go new file mode 100644 index 0000000..33df918 --- /dev/null +++ b/websocket-transport/socks.go @@ -0,0 +1,82 @@ +package main + +import ( + "bufio" + "errors" + "fmt" + "io" + "net" +) + +const ( + socksVersion = 0x04 + socksCmdConnect = 0x01 + socksResponseVersion = 0x00 + socksRequestGranted = 0x5a + socksRequestFailed = 0x5b +) + +func readSocks4aConnect(s io.Reader) (string, error) { + r := bufio.NewReader(s) + + var h [8]byte + n, err := io.ReadFull(r, h[:]) + if err != nil { + return "", errors.New(fmt.Sprintf("after %d bytes of SOCKS header: %s", n, err)) + } + if h[0] != socksVersion { + return "", errors.New(fmt.Sprintf("SOCKS header had version 0x%02x, not 0x%02x", h[0], socksVersion)) + } + if h[1] != socksCmdConnect { + return "", errors.New(fmt.Sprintf("SOCKS header had command 0x%02x, not 0x%02x", h[1], socksCmdConnect)) + } + + _, err = r.ReadBytes('\x00') + if err != nil { + return "", errors.New(fmt.Sprintf("reading SOCKS userid: %s", n, err)) + } + + var port int + var host string + + port = int(h[2])<<8 | int(h[3])<<0 + if h[4] == 0 && h[5] == 0 && h[6] == 0 && h[7] != 0 { + hostBytes, err := r.ReadBytes('\x00') + if err != nil { + return "", errors.New(fmt.Sprintf("reading SOCKS4a destination: %s", err)) + } + host = string(hostBytes[:len(hostBytes)-1]) + } else { + host = net.IPv4(h[4], h[5], h[6], h[7]).String() + } + + if r.Buffered() != 0 { + return "", errors.New(fmt.Sprintf("%d bytes left after SOCKS header", r.Buffered())) + } + + return fmt.Sprintf("%s:%d", host, port), nil +} + +func sendSocks4aResponse(w io.Writer, code byte, addr *net.TCPAddr) error { + var resp [8]byte + resp[0] = socksResponseVersion + resp[1] = code + resp[2] = byte((addr.Port >> 8) & 0xff) + resp[3] = byte((addr.Port >> 0) & 0xff) + resp[4] = addr.IP[0] + resp[5] = addr.IP[1] + resp[6] = addr.IP[2] + resp[7] = addr.IP[3] + _, err := w.Write(resp[:]) + return err +} + +var emptyAddr = net.TCPAddr{net.IPv4(0, 0, 0, 0), 0} + +func sendSocks4aResponseGranted(w io.Writer, addr *net.TCPAddr) error { + return sendSocks4aResponse(w, socksRequestGranted, addr) +} + +func sendSocks4aResponseFailed(w io.Writer) error { + return sendSocks4aResponse(w, socksRequestFailed, &emptyAddr) +} diff --git a/websocket-transport/websocket-client.go b/websocket-transport/websocket-client.go new file mode 100644 index 0000000..5c1c882 --- /dev/null +++ b/websocket-transport/websocket-client.go @@ -0,0 +1,120 @@ +package main + +import ( + "code.google.com/p/go.net/websocket" + "fmt" + "io" + "net" + "net/url" + "os" + "time" +) + +const socksTimeout = 2 + +func logDebug(format string, v ...interface{}) { + fmt.Fprintf(os.Stderr, format+"\n", v...) +} + +func proxy(local *net.TCPConn, ws *websocket.Conn) error { + // Local-to-WebSocket read loop. + go func() { + n, err := io.Copy(ws, local) + logDebug("end local-to-WebSocket %d %s", n, err) + }() + + // WebSocket-to-local read loop. + go func() { + n, err := io.Copy(local, ws) + logDebug("end WebSocket-to-local %d %s", n, err) + }() + + select {} + return nil +} + +func handleConnection(conn *net.TCPConn) error { + defer conn.Close() + + conn.SetDeadline(time.Now().Add(socksTimeout * time.Second)) + dest, err := readSocks4aConnect(conn) + if err != nil { + sendSocks4aResponseFailed(conn) + return err + } + // Disable deadline. + conn.SetDeadline(time.Time{}) + logDebug("SOCKS request for %s", dest) + + // We need the parsed IP and port for the SOCKS reply. + destAddr, err := net.ResolveTCPAddr("tcp", dest) + if err != nil { + sendSocks4aResponseFailed(conn) + return err + } + + wsUrl := url.URL{Scheme: "ws", Host: dest} + ws, err := websocket.Dial(wsUrl.String(), "", wsUrl.String()) + if err != nil { + sendSocks4aResponseFailed(conn) + return err + } + defer ws.Close() + logDebug("WebSocket connection to %s", ws.Config().Location.String()) + + sendSocks4aResponseGranted(conn, destAddr) + + return proxy(conn, ws) +} + +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 socksAddrStrs = [...]string{"127.0.0.1:0", "[::1]:0"} + + ptClientSetup([]string{ptMethodName}) + + for _, socksAddrStr := range socksAddrStrs { + ln, err := startListener(socksAddrStr) + if err != nil { + ptCmethodError(ptMethodName, err.Error()) + } + ptCmethod(ptMethodName, "socks4", ln.Addr()) + } + ptCmethodsDone() + + select {} +}

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