socks5 proxy implementation from shadowsocks

socks5_proxy.py

#!/usr/bin/env python

# Copyright (c) 2013 clowwindy
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

# @2013.08.22 by felix021
# This file is modified fron local.py from shadowsocks 1.3.3 to act as a pure
# socks5 proxy.
# usage:
#    python ssocks5.py          #listens on 7070
#    python ssocks5.py 1080     #listens on 1080

from __future__ import with_statement
import sys

try:
    import gevent
    import gevent.monkey
    gevent.monkey.patch_all(dns=gevent.version_info[0] >= 1)
except ImportError:
    gevent = None
    print >>sys.stderr, 'warning: gevent not found, using threading instead'

import socket
import select
import SocketServer
import struct
import os
import logging
import getopt


def send_all(sock, data):
    bytes_sent = 0
    while True:
        r = sock.send(data[bytes_sent:])
        if r < 0:
            return r
        bytes_sent += r
        if bytes_sent == len(data):
            return bytes_sent


class ThreadingTCPServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer):
    allow_reuse_address = True


class Socks5Server(SocketServer.StreamRequestHandler):
    def handle_tcp(self, sock, remote):
        try:
            fdset = [sock, remote]
            while True:
                r, w, e = select.select(fdset, [], [])
                if sock in r:
                    data = sock.recv(4096)
                    if len(data) <= 0:
                        break
                    result = send_all(remote, data)
                    if result < len(data):
                        raise Exception('failed to send all data')

                if remote in r:
                    data = remote.recv(4096)
                    if len(data) <= 0:
                        break
                    result = send_all(sock, data)
                    if result < len(data):
                        raise Exception('failed to send all data')
        finally:
            sock.close()
            remote.close()

    def handle(self):
        try:
            sock = self.connection
            sock.recv(262)
            sock.send("\x05\x00")
            data = self.rfile.read(4) or '\x00' * 4
            mode = ord(data[1])
            if mode != 1:
                #logging.warn('mode != 1')
                return

            addrtype = ord(data[3])
            if addrtype == 1:
                addr_ip = self.rfile.read(4)
                addr = socket.inet_ntoa(addr_ip)
            elif addrtype == 3:
                addr_len = self.rfile.read(1)
                addr = self.rfile.read(ord(addr_len))
            elif addrtype == 4:
                addr_ip = self.rfile.read(16)
                addr = socket.inet_ntop(socket.AF_INET6, addr_ip)
            else:
                #logging.warn('addr_type not support')
                # not support
                return
            addr_port = self.rfile.read(2)
            port = struct.unpack('>H', addr_port)
            try:
                reply = "\x05\x00\x00\x01"
                reply += socket.inet_aton('0.0.0.0') + struct.pack(">H", 2222)
                self.wfile.write(reply)
                # reply immediately
                remote = socket.create_connection((addr, port[0]))
                #logging.info('connecting %s:%d' % (addr, port[0]))
            except socket.error, e:
                #logging.warn(e)
                return
            self.handle_tcp(sock, remote)
        except socket.error, e:
            #logging.warn(e)
            pass


def main():
    global PORT, LOCAL, IPv6
    
    logging.basicConfig(level=logging.DEBUG,
                        format='%(asctime)s %(levelname)-8s %(message)s',
                        datefmt='%Y-%m-%d %H:%M:%S', filemode='a+')

    # fix py2exe
    if hasattr(sys, "frozen") and sys.frozen in \
            ("windows_exe", "console_exe"):
        p = os.path.dirname(os.path.abspath(sys.executable))
        os.chdir(p)

    KEY = None
    METHOD = None
    LOCAL = ''
    IPv6 = False
    
    PORT = 7070
    if len(sys.argv) > 1:
        PORT = int(sys.argv[1])

    try:
        if IPv6:
            ThreadingTCPServer.address_family = socket.AF_INET6
        server = ThreadingTCPServer((LOCAL, PORT), Socks5Server)
        logging.info("starting local at %s:%d" % tuple(server.server_address[:2]))
        server.serve_forever()
    except socket.error, e:
        logging.error(e)
    except KeyboardInterrupt:
        server.shutdown()
        sys.exit(0)
        
if __name__ == '__main__':
    main()