Refactoring main into separate modules

6 files changed, 91 insertions, 935 deletions

diff --git a/obfs4proxy/obfs4proxy.go b/obfs4proxy/obfs4proxy.go
index f66f7c0..92a34c0 100644
--- a/obfs4proxy/obfs4proxy.go
+++ b/obfs4proxy/obfs4proxy.go
@@ -32,22 +32,21 @@ package main
 import (
 	"flag"
 	"fmt"
-	"io"
 	golog "log"
 	"net"
-	"net/url"
 	"os"
 	"path"
-	"sync"
 	"syscall"
 
-	"golang.org/x/net/proxy"
-
 	"git.torproject.org/pluggable-transports/goptlib.git"
-	"git.torproject.org/pluggable-transports/obfs4.git/common/log"
-	"git.torproject.org/pluggable-transports/obfs4.git/common/socks5"
-	"git.torproject.org/pluggable-transports/obfs4.git/transports"
-	"git.torproject.org/pluggable-transports/obfs4.git/transports/base"
+	"github.com/OperatorFoundation/obfs4/common/log"
+	"github.com/OperatorFoundation/obfs4/common/termmon"
+	"github.com/OperatorFoundation/obfs4/common/pt_extras"
+	"github.com/OperatorFoundation/obfs4/transports"
+
+	"github.com/OperatorFoundation/obfs4/proxies/proxy_socks5"
+	"github.com/OperatorFoundation/obfs4/proxies/proxy_transparent"
+	"github.com/OperatorFoundation/obfs4/proxies/proxy_transparent_udp"
 )
 
 const (
@@ -57,249 +56,7 @@ const (
 )
 
 var stateDir string
-var termMon *termMonitor
-
-func clientSetup() (launched bool, listeners []net.Listener) {
-	ptClientInfo, err := pt.ClientSetup(transports.Transports())
-	if err != nil {
-		golog.Fatal(err)
-	}
-
-	ptClientProxy, err := ptGetProxy()
-	if err != nil {
-		golog.Fatal(err)
-	} else if ptClientProxy != nil {
-		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(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(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(f, conn, proxyURI)
-	}
-}
-
-func clientHandler(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
-	}
-	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() (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(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(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(f, conn, info)
-	}
-}
-
-func serverHandler(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
-}
+var termMon *termmon.TermMonitor
 
 func getVersion() string {
 	return fmt.Sprintf("obfs4proxy-%s", obfs4proxyVersion)
@@ -307,7 +64,7 @@ func getVersion() string {
 
 func main() {
 	// Initialize the termination state monitor as soon as possible.
-	termMon = newTermMonitor()
+	termMon = termmon.NewTermMonitor()
 
 	// Handle the command line arguments.
 	_, execName := path.Split(os.Args[0])
@@ -315,6 +72,13 @@ func main() {
 	logLevelStr := flag.String("logLevel", "ERROR", "Log level (ERROR/WARN/INFO/DEBUG)")
 	enableLogging := flag.Bool("enableLogging", false, "Log to TOR_PT_STATE_LOCATION/"+obfs4proxyLogFile)
 	unsafeLogging := flag.Bool("unsafeLogging", false, "Disable the address scrubber")
+	transparent := flag.Bool("transparent", false, "Enable transparent proxy mode")
+	udp := flag.Bool("udp", false, "Enable UDP proxy mode")
+	target := flag.String("target", "", "Specify transport server destination address")
+	clientMode := flag.Bool("client", false, "Enable client mode")
+	serverMode := flag.Bool("server", false, "Enable server mode")
+	statePath := flag.String("state", "", "Specify transport server destination address")
+	bindAddr := flag.String("bindaddr", "", "Specify the bind address for transparent server")
 	flag.Parse()
 
 	if *showVer {
@@ -328,11 +92,11 @@ func main() {
 	// Determine if this is a client or server, initialize the common state.
 	var ptListeners []net.Listener
 	launched := false
-	isClient, err := ptIsClient()
+	isClient, err := checkIsClient(*clientMode, *serverMode)
 	if err != nil {
 		golog.Fatalf("[ERROR]: %s - must be run as a managed transport", execName)
 	}
-	if stateDir, err = pt.MakeStateDir(); err != nil {
+	if stateDir, err = makeStateDir(*statePath); err != nil {
 		golog.Fatalf("[ERROR]: %s - No state directory: %s", execName, err)
 	}
 	if err = log.Init(*enableLogging, path.Join(stateDir, obfs4proxyLogFile), *unsafeLogging); err != nil {
@@ -345,14 +109,58 @@ func main() {
 
 	log.Noticef("%s - launched", getVersion())
 
-	// Do the managed pluggable transport protocol configuration.
-	if isClient {
-		log.Infof("%s - initializing client transport listeners", execName)
-		launched, ptListeners = clientSetup()
+  if *transparent {
+		// Do the transparent proxy configuration.
+		log.Infof("%s - initializing transparent proxy", execName)
+		if *udp {
+			log.Infof("%s - initializing UDP transparent proxy", execName)
+			if isClient {
+				log.Infof("%s - initializing client transport listeners", execName)
+				if *target == "" {
+					log.Errorf("%s - transparent mode requires a target", execName)
+				} else {
+					launched = proxy_transparent_udp.ClientSetup(termMon, *target)
+				}
+			} else {
+				log.Infof("%s - initializing server transport listeners", execName)
+				if *bindAddr == "" {
+					fmt.Println("%s - transparent mode requires a bindaddr", execName)
+				} else {
+					launched = proxy_transparent_udp.ServerSetup(termMon, *bindAddr)
+					fmt.Println("launched", launched, ptListeners)
+				}
+			}
+		} else {
+			log.Infof("%s - initializing TCP transparent proxy", execName)
+			if isClient {
+				log.Infof("%s - initializing client transport listeners", execName)
+				if *target == "" {
+					log.Errorf("%s - transparent mode requires a target", execName)
+				} else {
+					launched, ptListeners = proxy_transparent.ClientSetup(termMon, *target)
+				}
+			} else {
+				log.Infof("%s - initializing server transport listeners", execName)
+				if *bindAddr == "" {
+					fmt.Println("%s - transparent mode requires a bindaddr", execName)
+				} else {
+					launched, ptListeners = proxy_transparent.ServerSetup(termMon, *bindAddr)
+					fmt.Println("launched", launched, ptListeners)
+				}
+			}
+		}
 	} else {
-		log.Infof("%s - initializing server transport listeners", execName)
-		launched, ptListeners = serverSetup()
+		// Do the managed pluggable transport protocol configuration.
+		log.Infof("%s - initializing PT 1.0 proxy", execName)
+		if isClient {
+			log.Infof("%s - initializing client transport listeners", execName)
+			launched, ptListeners = proxy_socks5.ClientSetup(termMon)
+		} else {
+			log.Infof("%s - initializing server transport listeners", execName)
+			launched, ptListeners = proxy_socks5.ServerSetup(termMon)
+		}
 	}
+
 	if !launched {
 		// Initialization failed, the client or server setup routines should
 		// have logged, so just exit here.
@@ -368,7 +176,7 @@ func main() {
 	// connections will be processed.  Wait till the parent dies
 	// (immediate exit), a SIGTERM is received (immediate exit),
 	// or a SIGINT is received.
-	if sig := termMon.wait(false); sig == syscall.SIGTERM {
+	if sig := termMon.Wait(false); sig == syscall.SIGTERM {
 		return
 	}
 
@@ -378,5 +186,25 @@ func main() {
 	for _, ln := range ptListeners {
 		ln.Close()
 	}
-	termMon.wait(true)
+
+	termMon.Wait(true)
+}
+
+func checkIsClient(client bool, server bool) (bool, error) {
+	if client {
+		return true, nil
+	} else if server {
+		return false, nil
+	} else {
+		return pt_extras.PtIsClient()
+	}
+}
+
+func makeStateDir(statePath string) (string, error) {
+	if statePath != "" {
+		err := os.MkdirAll(statePath, 0700)
+		return statePath, err
+	} else {
+		return pt.MakeStateDir()
+	}
 }
diff --git a/obfs4proxy/proxy_http.go b/obfs4proxy/proxy_http.go
deleted file mode 100644
index 6f11790..0000000
--- a/obfs4proxy/proxy_http.go
+++ /dev/null
@@ -1,158 +0,0 @@
-/*
- * Copyright (c) 2014, 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.
- */
-
-package main
-
-import (
-	"bufio"
-	"fmt"
-	"net"
-	"net/http"
-	"net/http/httputil"
-	"net/url"
-	"time"
-
-	"golang.org/x/net/proxy"
-)
-
-// httpProxy is a HTTP connect proxy.
-type httpProxy struct {
-	hostPort string
-	haveAuth bool
-	username string
-	password string
-	forward  proxy.Dialer
-}
-
-func newHTTP(uri *url.URL, forward proxy.Dialer) (proxy.Dialer, error) {
-	s := new(httpProxy)
-	s.hostPort = uri.Host
-	s.forward = forward
-	if uri.User != nil {
-		s.haveAuth = true
-		s.username = uri.User.Username()
-		s.password, _ = uri.User.Password()
-	}
-
-	return s, nil
-}
-
-func (s *httpProxy) Dial(network, addr string) (net.Conn, error) {
-	// Dial and create the http client connection.
-	c, err := s.forward.Dial("tcp", s.hostPort)
-	if err != nil {
-		return nil, err
-	}
-	conn := new(httpConn)
-	conn.httpConn = httputil.NewClientConn(c, nil)
-	conn.remoteAddr, err = net.ResolveTCPAddr(network, addr)
-	if err != nil {
-		conn.httpConn.Close()
-		return nil, err
-	}
-
-	// HACK HACK HACK HACK.  http.ReadRequest also does this.
-	reqURL, err := url.Parse("http://" + addr)
-	if err != nil {
-		conn.httpConn.Close()
-		return nil, err
-	}
-	reqURL.Scheme = ""
-
-	req, err := http.NewRequest("CONNECT", reqURL.String(), nil)
-	if err != nil {
-		conn.httpConn.Close()
-		return nil, err
-	}
-	req.Close = false
-	if s.haveAuth {
-		req.SetBasicAuth(s.username, s.password)
-	}
-	req.Header.Set("User-Agent", "")
-
-	resp, err := conn.httpConn.Do(req)
-	if err != nil && err != httputil.ErrPersistEOF {
-		conn.httpConn.Close()
-		return nil, err
-	}
-	if resp.StatusCode != 200 {
-		conn.httpConn.Close()
-		return nil, fmt.Errorf("proxy error: %s", resp.Status)
-	}
-
-	conn.hijackedConn, conn.staleReader = conn.httpConn.Hijack()
-	return conn, nil
-}
-
-type httpConn struct {
-	remoteAddr   *net.TCPAddr
-	httpConn     *httputil.ClientConn
-	hijackedConn net.Conn
-	staleReader  *bufio.Reader
-}
-
-func (c *httpConn) Read(b []byte) (int, error) {
-	if c.staleReader != nil {
-		if c.staleReader.Buffered() > 0 {
-			return c.staleReader.Read(b)
-		}
-		c.staleReader = nil
-	}
-	return c.hijackedConn.Read(b)
-}
-
-func (c *httpConn) Write(b []byte) (int, error) {
-	return c.hijackedConn.Write(b)
-}
-
-func (c *httpConn) Close() error {
-	return c.hijackedConn.Close()
-}
-
-func (c *httpConn) LocalAddr() net.Addr {
-	return c.hijackedConn.LocalAddr()
-}
-
-func (c *httpConn) RemoteAddr() net.Addr {
-	return c.remoteAddr
-}
-
-func (c *httpConn) SetDeadline(t time.Time) error {
-	return c.hijackedConn.SetDeadline(t)
-}
-
-func (c *httpConn) SetReadDeadline(t time.Time) error {
-	return c.hijackedConn.SetReadDeadline(t)
-}
-
-func (c *httpConn) SetWriteDeadline(t time.Time) error {
-	return c.hijackedConn.SetWriteDeadline(t)
-}
-
-func init() {
-	proxy.RegisterDialerType("http", newHTTP)
-}
diff --git a/obfs4proxy/proxy_socks4.go b/obfs4proxy/proxy_socks4.go
deleted file mode 100644
index 536dd96..0000000
--- a/obfs4proxy/proxy_socks4.go
+++ /dev/null
@@ -1,164 +0,0 @@
-/*
- * Copyright (c) 2014, 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.
- *
- * This is inspired by go.net/proxy/socks5.go:
- *
- * Copyright 2011 The Go Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style
- * license that can be found in the LICENSE file.
- */
-
-package main
-
-import (
-	"errors"
-	"fmt"
-	"io"
-	"net"
-	"net/url"
-	"strconv"
-
-	"golang.org/x/net/proxy"
-)
-
-// socks4Proxy is a SOCKS4 proxy.
-type socks4Proxy struct {
-	hostPort string
-	username string
-	forward  proxy.Dialer
-}
-
-const (
-	socks4Version        = 0x04
-	socks4CommandConnect = 0x01
-	socks4Null           = 0x00
-	socks4ReplyVersion   = 0x00
-
-	socks4Granted                = 0x5a
-	socks4Rejected               = 0x5b
-	socks4RejectedIdentdFailed   = 0x5c
-	socks4RejectedIdentdMismatch = 0x5d
-)
-
-func newSOCKS4(uri *url.URL, forward proxy.Dialer) (proxy.Dialer, error) {
-	s := new(socks4Proxy)
-	s.hostPort = uri.Host
-	s.forward = forward
-	if uri.User != nil {
-		s.username = uri.User.Username()
-	}
-	return s, nil
-}
-
-func (s *socks4Proxy) Dial(network, addr string) (net.Conn, error) {
-	if network != "tcp" && network != "tcp4" {
-		return nil, errors.New("invalid network type")
-	}
-
-	// Deal with the destination address/string.
-	ipStr, portStr, err := net.SplitHostPort(addr)
-	if err != nil {
-		return nil, err
-	}
-	ip := net.ParseIP(ipStr)
-	if ip == nil {
-		return nil, errors.New("failed to parse destination IP")
-	}
-	ip4 := ip.To4()
-	if ip4 == nil {
-		return nil, errors.New("destination address is not IPv4")
-	}
-	port, err := strconv.ParseUint(portStr, 10, 16)
-	if err != nil {
-		return nil, err
-	}
-
-	// Connect to the proxy.
-	c, err := s.forward.Dial("tcp", s.hostPort)
-	if err != nil {
-		return nil, err
-	}
-
-	// Make/write the request:
-	//  +----+----+----+----+----+----+----+----+----+----+....+----+
-	//  | VN | CD | DSTPORT |      DSTIP        | USERID       |NULL|
-	//  +----+----+----+----+----+----+----+----+----+----+....+----+
-
-	req := make([]byte, 0, 9+len(s.username))
-	req = append(req, socks4Version)
-	req = append(req, socks4CommandConnect)
-	req = append(req, byte(port>>8), byte(port))
-	req = append(req, ip4...)
-	if s.username != "" {
-		req = append(req, s.username...)
-	}
-	req = append(req, socks4Null)
-	_, err = c.Write(req)
-	if err != nil {
-		c.Close()
-		return nil, err
-	}
-
-	// Read the response:
-	// +----+----+----+----+----+----+----+----+
-	// | VN | CD | DSTPORT |      DSTIP        |
-	// +----+----+----+----+----+----+----+----+
-
-	var resp [8]byte
-	_, err = io.ReadFull(c, resp[:])
-	if err != nil {
-		c.Close()
-		return nil, err
-	}
-	if resp[0] != socks4ReplyVersion {
-		c.Close()
-		return nil, errors.New("proxy returned invalid SOCKS4 version")
-	}
-	if resp[1] != socks4Granted {
-		c.Close()
-		return nil, fmt.Errorf("proxy error: %s", socks4ErrorToString(resp[1]))
-	}
-
-	return c, nil
-}
-
-func socks4ErrorToString(code byte) string {
-	switch code {
-	case socks4Rejected:
-		return "request rejected or failed"
-	case socks4RejectedIdentdFailed:
-		return "request rejected becasue SOCKS server cannot connect to identd on the client"
-	case socks4RejectedIdentdMismatch:
-		return "request rejected because the client program and identd report different user-ids"
-	default:
-		return fmt.Sprintf("unknown failure code %x", code)
-	}
-}
-
-func init() {
-	// Despite the scheme name, this really is SOCKS4.
-	proxy.RegisterDialerType("socks4a", newSOCKS4)
-}
diff --git a/obfs4proxy/pt_extras.go b/obfs4proxy/pt_extras.go
deleted file mode 100644
index f490fbc..0000000
--- a/obfs4proxy/pt_extras.go
+++ /dev/null
@@ -1,166 +0,0 @@
-/*
- * Copyright (c) 2014, 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.
- */
-
-package main
-
-import (
-	"errors"
-	"fmt"
-	"net"
-	"net/url"
-	"os"
-	"strconv"
-
-	"git.torproject.org/pluggable-transports/goptlib.git"
-)
-
-// This file contains things that probably should be in goptlib but are not
-// yet or are not finalized.
-
-func ptEnvError(msg string) error {
-	line := []byte(fmt.Sprintf("ENV-ERROR %s\n", msg))
-	pt.Stdout.Write(line)
-	return errors.New(msg)
-}
-
-func ptProxyError(msg string) error {
-	line := []byte(fmt.Sprintf("PROXY-ERROR %s\n", msg))
-	pt.Stdout.Write(line)
-	return errors.New(msg)
-}
-
-func ptProxyDone() {
-	line := []byte("PROXY DONE\n")
-	pt.Stdout.Write(line)
-}
-
-func ptIsClient() (bool, error) {
-	clientEnv := os.Getenv("TOR_PT_CLIENT_TRANSPORTS")
-	serverEnv := os.Getenv("TOR_PT_SERVER_TRANSPORTS")
-	if clientEnv != "" && serverEnv != "" {
-		return false, ptEnvError("TOR_PT_[CLIENT,SERVER]_TRANSPORTS both set")
-	} else if clientEnv != "" {
-		return true, nil
-	} else if serverEnv != "" {
-		return false, nil
-	}
-	return false, errors.New("not launched as a managed transport")
-}
-
-func ptGetProxy() (*url.URL, error) {
-	specString := os.Getenv("TOR_PT_PROXY")
-	if specString == "" {
-		return nil, nil
-	}
-	spec, err := url.Parse(specString)
-	if err != nil {
-		return nil, ptProxyError(fmt.Sprintf("failed to parse proxy config: %s", err))
-	}
-
-	// Validate the TOR_PT_PROXY uri.
-	if !spec.IsAbs() {
-		return nil, ptProxyError("proxy URI is relative, must be absolute")
-	}
-	if spec.Path != "" {
-		return nil, ptProxyError("proxy URI has a path defined")
-	}
-	if spec.RawQuery != "" {
-		return nil, ptProxyError("proxy URI has a query defined")
-	}
-	if spec.Fragment != "" {
-		return nil, ptProxyError("proxy URI has a fragment defined")
-	}
-
-	switch spec.Scheme {
-	case "http":
-		// The most forgiving of proxies.
-
-	case "socks4a":
-		if spec.User != nil {
-			_, isSet := spec.User.Password()
-			if isSet {
-				return nil, ptProxyError("proxy URI specified SOCKS4a and a password")
-			}
-		}
-
-	case "socks5":
-		if spec.User != nil {
-			// UNAME/PASSWD both must be between 1 and 255 bytes long. (RFC1929)
-			user := spec.User.Username()
-			passwd, isSet := spec.User.Password()
-			if len(user) < 1 || len(user) > 255 {
-				return nil, ptProxyError("proxy URI specified a invalid SOCKS5 username")
-			}
-			if !isSet || len(passwd) < 1 || len(passwd) > 255 {
-				return nil, ptProxyError("proxy URI specified a invalid SOCKS5 password")
-			}
-		}
-
-	default:
-		return nil, ptProxyError(fmt.Sprintf("proxy URI has invalid scheme: %s", spec.Scheme))
-	}
-
-	_, err = resolveAddrStr(spec.Host)
-	if err != nil {
-		return nil, ptProxyError(fmt.Sprintf("proxy URI has invalid host: %s", err))
-	}
-
-	return spec, nil
-}
-
-// Sigh, pt.resolveAddr() isn't exported.  Include our own getto version that
-// doesn't work around #7011, because we don't work with pre-0.2.5.x tor, and
-// all we care about is validation anyway.
-func resolveAddrStr(addrStr string) (*net.TCPAddr, error) {
-	ipStr, portStr, err := net.SplitHostPort(addrStr)
-	if err != nil {
-		return nil, err
-	}
-
-	if ipStr == "" {
-		return nil, net.InvalidAddrError(fmt.Sprintf("address string %q lacks a host part", addrStr))
-	}
-	if portStr == "" {
-		return nil, net.InvalidAddrError(fmt.Sprintf("address string %q lacks a port part", addrStr))
-	}
-	ip := net.ParseIP(ipStr)
-	if ip == nil {
-		return nil, net.InvalidAddrError(fmt.Sprintf("not an IP string: %q", ipStr))
-	}
-	port, err := strconv.ParseUint(portStr, 10, 16)
-	if err != nil {
-		return nil, net.InvalidAddrError(fmt.Sprintf("not a Port string: %q", portStr))
-	}
-
-	return &net.TCPAddr{IP: ip, Port: int(port), Zone: ""}, nil
-}
-
-// Feature #15435 adds a new env var for determining if Tor keeps stdin
-// open for use in termination detection.
-func ptShouldExitOnStdinClose() bool {
-	return os.Getenv("TOR_PT_EXIT_ON_STDIN_CLOSE") == "1"
-}
diff --git a/obfs4proxy/termmon.go b/obfs4proxy/termmon.go
deleted file mode 100644
index 86db190..0000000
--- a/obfs4proxy/termmon.go
+++ /dev/null
@@ -1,135 +0,0 @@
-/*
- * Copyright (c) 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.
- */
-
-package main
-
-import (
-	"io"
-	"io/ioutil"
-	"os"
-	"os/signal"
-	"runtime"
-	"syscall"
-	"time"
-
-	"git.torproject.org/pluggable-transports/obfs4.git/common/log"
-)
-
-var termMonitorOSInit func(*termMonitor) error
-
-type termMonitor struct {
-	sigChan     chan os.Signal
-	handlerChan chan int
-	numHandlers int
-}
-
-func (m *termMonitor) onHandlerStart() {
-	m.handlerChan <- 1
-}
-
-func (m *termMonitor) onHandlerFinish() {
-	m.handlerChan <- -1
-}
-
-func (m *termMonitor) wait(termOnNoHandlers bool) os.Signal {
-	// Block until a signal has been received, or (optionally) the
-	// number of pending handlers has hit 0.  In the case of the
-	// latter, treat it as if a SIGTERM has been received.
-	for {
-		select {
-		case n := <-m.handlerChan:
-			m.numHandlers += n
-		case sig := <-m.sigChan:
-			return sig
-		}
-		if termOnNoHandlers && m.numHandlers == 0 {
-			return syscall.SIGTERM
-		}
-	}
-}
-
-func (m *termMonitor) termOnStdinClose() {
-	_, err := io.Copy(ioutil.Discard, os.Stdin)
-
-	// io.Copy() will return a nil on EOF, since reaching EOF is
-	// expected behavior.  No matter what, if this unblocks, assume
-	// that stdin is closed, and treat that as having received a
-	// SIGTERM.
-	log.Noticef("Stdin is closed or unreadable: %v", err)
-	m.sigChan <- syscall.SIGTERM
-}
-
-func (m *termMonitor) termOnPPIDChange(ppid int) {
-	// Under most if not all U*IX systems, the parent PID will change
-	// to that of init once the parent dies.  There are several notable
-	// exceptions (Slowlaris/Android), but the parent PID changes
-	// under those platforms as well.
-	//
-	// Naturally we lose if the parent has died by the time when the
-	// Getppid() call was issued in our parent, but, this is better
-	// than nothing.
-	const ppidPollInterval = 1 * time.Second
-	for ppid == os.Getppid() {
-		time.Sleep(ppidPollInterval)
-	}
-
-	// Treat the parent PID changing as the same as having received
-	// a SIGTERM.
-	log.Noticef("Parent pid changed: %d (was %d)", os.Getppid(), ppid)
-	m.sigChan <- syscall.SIGTERM
-}
-
-func newTermMonitor() (m *termMonitor) {
-	ppid := os.Getppid()
-	m = new(termMonitor)
-	m.sigChan = make(chan os.Signal)
-	m.handlerChan = make(chan int)
-	signal.Notify(m.sigChan, syscall.SIGINT, syscall.SIGTERM)
-
-	// If tor supports feature #15435, we can use Stdin being closed as an
-	// indication that tor has died, or wants the PT to shutdown for any
-	// reason.
-	if ptShouldExitOnStdinClose() {
-		go m.termOnStdinClose()
-	} else {
-		// Instead of feature #15435, use various kludges and hacks:
-		//  * Linux - Platform specific code that should always work.
-		//  * Other U*IX - Somewhat generic code, that works unless the
-		//    parent dies before the monitor is initialized.
-		if termMonitorOSInit != nil {
-			// Errors here are non-fatal, since it might still be
-			// possible to fall back to a generic implementation.
-			if err := termMonitorOSInit(m); err == nil {
-				return
-			}
-		}
-		if runtime.GOOS != "windows" {
-			go m.termOnPPIDChange(ppid)
-		}
-	}
-	return
-}
diff --git a/obfs4proxy/termmon_linux.go b/obfs4proxy/termmon_linux.go
deleted file mode 100644
index 9711cfc..0000000
--- a/obfs4proxy/termmon_linux.go
+++ /dev/null
@@ -1,49 +0,0 @@
-/*
- * Copyright (c) 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.
- */
-
-package main
-
-import (
-	"fmt"
-	"syscall"
-)
-
-func termMonitorInitLinux(m *termMonitor) error {
-	// Use prctl() to have the kernel deliver a SIGTERM if the parent
-	// process dies.  This beats anything else that can be done before
-	// #15435 is implemented.
-	_, _, errno := syscall.Syscall(syscall.SYS_PRCTL, syscall.PR_SET_PDEATHSIG, uintptr(syscall.SIGTERM), 0)
-	if errno != 0 {
-		var err error = errno
-		return fmt.Errorf("prctl(PR_SET_PDEATHSIG, SIGTERM) returned: %s", err)
-	}
-	return nil
-}
-
-func init() {
-	termMonitorOSInit = termMonitorInitLinux
-}