Split "proxies" into "proxy_dialers" and "modes"

Half of the packages in there registered dialer types with golang.org/x/net/proxy,
and half of them were proxying modes for the program as a whole.  These are separate
things, so move them into separate directories.

1 files changed, 303 insertions, 0 deletions

diff --git a/modes/pt_socks5/pt_socks5.go b/modes/pt_socks5/pt_socks5.go
new file mode 100644
index 0000000..579124f
--- /dev/null
+++ b/modes/pt_socks5/pt_socks5.go
@@ -0,0 +1,303 @@
+/*
+ * Copyright (c) 2014-2015, Yawning Angel <yawning at torproject dot org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Go language Tor Pluggable Transport suite.  Works only as a managed
+// client/server.
+package pt_socks5
+
+import (
+	"fmt"
+	"io"
+	golog "log"
+	"net"
+	"net/url"
+	"sync"
+
+	"golang.org/x/net/proxy"
+
+	"git.torproject.org/pluggable-transports/goptlib.git"
+	"github.com/OperatorFoundation/obfs4/common/log"
+	"github.com/OperatorFoundation/obfs4/common/pt_extras"
+	"github.com/OperatorFoundation/obfs4/common/socks5"
+	"github.com/OperatorFoundation/obfs4/common/termmon"
+	"github.com/OperatorFoundation/obfs4/transports"
+	"github.com/OperatorFoundation/obfs4/transports/base"
+)
+
+const (
+	obfs4proxyVersion = "0.0.7-dev"
+	obfs4proxyLogFile = "obfs4proxy.log"
+	socksAddr         = "127.0.0.1:0"
+)
+
+var stateDir string
+
+func ClientSetup(termMon *termmon.TermMonitor) (launched bool, listeners []net.Listener) {
+	ptClientInfo, err := pt.ClientSetup(transports.Transports())
+	if err != nil {
+		golog.Fatal(err)
+	}
+
+	ptClientProxy, err := pt_extras.PtGetProxy()
+	fmt.Println("ptclientproxy", ptClientProxy)
+	if err != nil {
+		golog.Fatal(err)
+	} else if ptClientProxy != nil {
+		pt_extras.PtProxyDone()
+	}
+
+	// Launch each of the client listeners.
+	for _, name := range ptClientInfo.MethodNames {
+		t := transports.Get(name)
+		if t == nil {
+			pt.CmethodError(name, "no such transport is supported")
+			continue
+		}
+
+		f, err := t.ClientFactory(stateDir)
+		if err != nil {
+			pt.CmethodError(name, "failed to get ClientFactory")
+			continue
+		}
+
+		ln, err := net.Listen("tcp", socksAddr)
+		if err != nil {
+			pt.CmethodError(name, err.Error())
+			continue
+		}
+
+		go clientAcceptLoop(termMon, f, ln, ptClientProxy)
+		pt.Cmethod(name, socks5.Version(), ln.Addr())
+
+		log.Infof("%s - registered listener: %s", name, ln.Addr())
+
+		listeners = append(listeners, ln)
+		launched = true
+	}
+	pt.CmethodsDone()
+
+	return
+}
+
+func clientAcceptLoop(termMon *termmon.TermMonitor, f base.ClientFactory, ln net.Listener, proxyURI *url.URL) error {
+	defer ln.Close()
+	for {
+		conn, err := ln.Accept()
+		if err != nil {
+			if e, ok := err.(net.Error); ok && !e.Temporary() {
+				return err
+			}
+			continue
+		}
+		go clientHandler(termMon, f, conn, proxyURI)
+	}
+}
+
+func clientHandler(termMon *termmon.TermMonitor, f base.ClientFactory, conn net.Conn, proxyURI *url.URL) {
+	defer conn.Close()
+	termMon.OnHandlerStart()
+	defer termMon.OnHandlerFinish()
+
+	name := f.Transport().Name()
+
+	// Read the client's SOCKS handshake.
+	socksReq, err := socks5.Handshake(conn)
+	if err != nil {
+		log.Errorf("%s - client failed socks handshake: %s", name, err)
+		return
+	}
+	addrStr := log.ElideAddr(socksReq.Target)
+
+	// Deal with arguments.
+	args, err := f.ParseArgs(&socksReq.Args)
+	if err != nil {
+		log.Errorf("%s(%s) - invalid arguments: %s", name, addrStr, err)
+		socksReq.Reply(socks5.ReplyGeneralFailure)
+		return
+	}
+
+	// Obtain the proxy dialer if any, and create the outgoing TCP connection.
+	dialFn := proxy.Direct.Dial
+	if proxyURI != nil {
+		dialer, err := proxy.FromURL(proxyURI, proxy.Direct)
+		if err != nil {
+			// This should basically never happen, since config protocol
+			// verifies this.
+			log.Errorf("%s(%s) - failed to obtain proxy dialer: %s", name, addrStr, log.ElideError(err))
+			socksReq.Reply(socks5.ReplyGeneralFailure)
+			return
+		}
+		dialFn = dialer.Dial
+	}
+
+	fmt.Println("Got dialer", dialFn, proxyURI, proxy.Direct)
+
+	remote, err := f.Dial("tcp", socksReq.Target, dialFn, args)
+	if err != nil {
+		log.Errorf("%s(%s) - outgoing connection failed: %s", name, addrStr, log.ElideError(err))
+		socksReq.Reply(socks5.ErrorToReplyCode(err))
+		return
+	}
+	defer remote.Close()
+	err = socksReq.Reply(socks5.ReplySucceeded)
+	if err != nil {
+		log.Errorf("%s(%s) - SOCKS reply failed: %s", name, addrStr, log.ElideError(err))
+		return
+	}
+
+	if err = copyLoop(conn, remote); err != nil {
+		log.Warnf("%s(%s) - closed connection: %s", name, addrStr, log.ElideError(err))
+	} else {
+		log.Infof("%s(%s) - closed connection", name, addrStr)
+	}
+
+	return
+}
+
+func ServerSetup(termMon *termmon.TermMonitor) (launched bool, listeners []net.Listener) {
+	ptServerInfo, err := pt.ServerSetup(transports.Transports())
+	if err != nil {
+		golog.Fatal(err)
+	}
+
+	for _, bindaddr := range ptServerInfo.Bindaddrs {
+		name := bindaddr.MethodName
+		t := transports.Get(name)
+		if t == nil {
+			pt.SmethodError(name, "no such transport is supported")
+			continue
+		}
+
+		f, err := t.ServerFactory(stateDir, &bindaddr.Options)
+		if err != nil {
+			pt.SmethodError(name, err.Error())
+			continue
+		}
+
+		ln, err := net.ListenTCP("tcp", bindaddr.Addr)
+		if err != nil {
+			pt.SmethodError(name, err.Error())
+			continue
+		}
+
+		go serverAcceptLoop(termMon, f, ln, &ptServerInfo)
+		if args := f.Args(); args != nil {
+			pt.SmethodArgs(name, ln.Addr(), *args)
+		} else {
+			pt.SmethodArgs(name, ln.Addr(), nil)
+		}
+
+		log.Infof("%s - registered listener: %s", name, log.ElideAddr(ln.Addr().String()))
+
+		listeners = append(listeners, ln)
+		launched = true
+	}
+	pt.SmethodsDone()
+
+	return
+}
+
+func serverAcceptLoop(termMon *termmon.TermMonitor, f base.ServerFactory, ln net.Listener, info *pt.ServerInfo) error {
+	defer ln.Close()
+	for {
+		conn, err := ln.Accept()
+		if err != nil {
+			if e, ok := err.(net.Error); ok && !e.Temporary() {
+				return err
+			}
+			continue
+		}
+		go serverHandler(termMon, f, conn, info)
+	}
+}
+
+func serverHandler(termMon *termmon.TermMonitor, f base.ServerFactory, conn net.Conn, info *pt.ServerInfo) {
+	defer conn.Close()
+	termMon.OnHandlerStart()
+	defer termMon.OnHandlerFinish()
+
+	name := f.Transport().Name()
+	addrStr := log.ElideAddr(conn.RemoteAddr().String())
+	log.Infof("%s(%s) - new connection", name, addrStr)
+
+	// Instantiate the server transport method and handshake.
+	remote, err := f.WrapConn(conn)
+	if err != nil {
+		log.Warnf("%s(%s) - handshake failed: %s", name, addrStr, log.ElideError(err))
+		return
+	}
+
+	// Connect to the orport.
+	orConn, err := pt.DialOr(info, conn.RemoteAddr().String(), name)
+	if err != nil {
+		log.Errorf("%s(%s) - failed to connect to ORPort: %s", name, addrStr, log.ElideError(err))
+		return
+	}
+	defer orConn.Close()
+
+	if err = copyLoop(orConn, remote); err != nil {
+		log.Warnf("%s(%s) - closed connection: %s", name, addrStr, log.ElideError(err))
+	} else {
+		log.Infof("%s(%s) - closed connection", name, addrStr)
+	}
+
+	return
+}
+
+func copyLoop(a net.Conn, b net.Conn) error {
+	// Note: b is always the pt connection.  a is the SOCKS/ORPort connection.
+	errChan := make(chan error, 2)
+
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	go func() {
+		defer wg.Done()
+		defer b.Close()
+		defer a.Close()
+		_, err := io.Copy(b, a)
+		errChan <- err
+	}()
+	go func() {
+		defer wg.Done()
+		defer a.Close()
+		defer b.Close()
+		_, err := io.Copy(a, b)
+		errChan <- err
+	}()
+
+	// Wait for both upstream and downstream to close.  Since one side
+	// terminating closes the other, the second error in the channel will be
+	// something like EINVAL (though io.Copy() will swallow EOF), so only the
+	// first error is returned.
+	wg.Wait()
+	if len(errChan) > 0 {
+		return <-errChan
+	}
+
+	return nil
+}