Python port of ShadowsocksR
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#!/usr/bin/python
# -*- coding: utf-8 -*-
# Copyright (c) 2014 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.
import time
import socket
import logging
import encrypt
import errno
import eventloop
from common import parse_header
# local:
# stage 0 init
# stage 1 hello received, hello sent
# stage 4 addr received, reply sent
# stage 5 remote connected
# remote:
# stage 0 init
# stage 4 addr received, reply sent
# stage 5 remote connected
BUF_SIZE = 8 * 1024
class TCPRelayHandler(object):
def __init__(self, fd_to_handlers, loop, local_sock, config, is_local):
self._fd_to_handlers = fd_to_handlers
self._loop = loop
self._local_sock = local_sock
self._remote_sock = None
self._config = config
self._is_local = is_local
self._stage = 0
self._encryptor = encrypt.Encryptor(config['password'],
config['method'])
self._data_to_write_to_local = []
self._data_to_write_to_remote = []
fd_to_handlers[local_sock.fileno()] = self
local_sock.setblocking(False)
loop.add(local_sock, eventloop.POLL_IN)
def resume_reading(self, sock):
pass
def pause_reading(self, sock):
pass
def resume_writing(self, sock):
pass
def pause_writing(self, sock):
pass
def write_all_to_sock(self, data, sock):
# write to sock
# put remaining bytes into buffer
# return true if all written
# return false if some bytes left in buffer
# raise if encounter error
return True
def on_local_read(self):
if not self._local_sock:
return
is_local = self._is_local
data = self._local_sock.recv(BUF_SIZE)
if not is_local:
data = self._encryptor.decrypt(data)
if self._stage == 5:
if self._is_local:
data = self._encryptor.encrypt(data)
if not self.write_all_to_sock(data, self._remote_sock):
self.pause_reading(self._local_sock)
return
if is_local and self._stage == 0:
# TODO check auth method
self.write_all_to_sock('\x05\00', self._local_sock)
self._stage = 1
return
if self._stage == 4:
self._data_to_write_to_remote.append(data)
if (is_local and self._stage == 0) or \
(not is_local and self._stage == 1):
try:
if is_local:
cmd = ord(data[1])
# TODO check cmd == 1
assert cmd == 1
# just trim VER CMD RSV
data = data[3:]
header_result = parse_header(data)
if header_result is None:
raise Exception('can not parse header')
addrtype, remote_addr, remote_port, header_length =\
header_result
logging.info('connecting %s:%d' % (remote_addr, remote_port))
if is_local:
# forward address to remote
self._data_to_write_to_remote.append(data[:header_length])
self.write_all_to_sock('\x05\x00\x00\x01' +
'\x00\x00\x00\x00\x10\x10',
self._local_sock)
else:
remote_addr = self._config['server']
remote_port = self._config['server_port']
# TODO async DNS
addrs = socket.getaddrinfo(remote_addr, remote_port, 0,
socket.SOCK_STREAM, socket.SOL_TCP)
if len(addrs) == 0:
raise Exception("can't get addrinfo for %s:%d" %
(remote_addr, remote_port))
af, socktype, proto, canonname, sa = addrs[0]
self._remote_sock = socket.socket(af, socktype, proto)
self._remote_sock.setblocking(False)
# TODO support TCP fast open
self._remote_sock.connect(sa)
self._loop.add(self._remote_sock, eventloop.POLL_OUT)
if len(data) > header_length:
self._data_to_write_to_remote.append(data[header_length:])
self._stage = 4
self.pause_reading(self._local_sock)
return
except Exception:
import traceback
traceback.print_exc()
# TODO use logging when debug completed
self.destroy()
if self._stage == 4:
self._data_to_write_to_remote.append(data)
def on_remote_read(self):
data = self._remote_sock.recv(BUF_SIZE)
if self._is_local:
data = self._encryptor.decrypt(data)
try:
if not self.write_all_to_sock(data, self._local_sock):
self.pause_reading(self._remote_sock)
self.resume_writing(self._local_sock)
except Exception:
import traceback
traceback.print_exc()
# TODO use logging when debug completed
self.destroy()
def on_local_write(self):
if self._data_to_write_to_local:
written = self.write_all_to_sock(
''.join(self._data_to_write_to_local), self._local_sock)
if written:
self.pause_writing(self._local_sock)
else:
self.pause_writing(self._local_sock)
def on_remote_write(self):
if self._data_to_write_to_remote:
written = self.write_all_to_sock(
''.join(self._data_to_write_to_remote), self._remote_sock)
if written:
self.pause_writing(self._remote_sock)
else:
self.pause_writing(self._remote_sock)
def on_local_error(self):
self.destroy()
def on_remote_error(self):
self.destroy()
def handle_event(self, sock, event):
# order is important
if sock == self._remote_sock:
if event & eventloop.POLL_IN:
self.on_remote_read()
if event & eventloop.POLL_OUT:
self.on_remote_write()
if event & eventloop.POLL_ERR:
self.on_remote_error()
elif sock == self._local_sock:
if event & eventloop.POLL_IN:
self.on_local_read()
if event & eventloop.POLL_OUT:
self.on_local_write()
if event & eventloop.POLL_ERR:
self.on_local_error()
else:
logging.warn('unknown socket')
def destroy(self):
if self._remote_sock:
self._remote_sock.close()
self._loop.remove(self._remote_sock)
del self._fd_to_handlers[self._remote_sock.fileno()]
self._remote_sock = None
if self._local_sock:
self._local_sock.close()
self._loop.remove(self._local_sock)
del self._fd_to_handlers[self._local_sock.fileno()]
self._local_sock = None
class TCPRelay(object):
def __init__(self, config, is_local):
self._config = config
self._is_local = is_local
self._closed = False
self._fd_to_handlers = {}
if is_local:
listen_addr = config['local_address']
listen_port = config['local_port']
else:
listen_addr = config['server']
listen_port = config['server_port']
addrs = socket.getaddrinfo(listen_addr, listen_port, 0,
socket.SOCK_STREAM, socket.SOL_TCP)
if len(addrs) == 0:
raise Exception("can't get addrinfo for %s:%d" %
(listen_addr, listen_port))
af, socktype, proto, canonname, sa = addrs[0]
server_socket = socket.socket(af, socktype, proto)
server_socket.bind(sa)
server_socket.setblocking(False)
server_socket.listen(1024)
self._server_socket = server_socket
def _run(self):
server_socket = self._server_socket
self._eventloop = eventloop.EventLoop()
self._eventloop.add(server_socket, eventloop.POLL_IN)
last_time = time.time()
while not self._closed:
try:
events = self._eventloop.poll(1)
except (OSError, IOError) as e:
if eventloop.errno_from_exception(e) == errno.EPIPE:
# Happens when the client closes the connection
continue
else:
logging.error(e)
continue
for sock, event in events:
if sock == self._server_socket:
try:
conn = self._server_socket.accept()
TCPRelayHandler(self._eventloop, conn, self._config,
self._is_local)
except (OSError, IOError) as e:
error_no = eventloop.errno_from_exception(e)
if error_no in [errno.EAGAIN, errno.EINPROGRESS]:
continue
else:
handler = self._fd_to_handlers.get(sock.fileno(), None)
if handler:
handler.handle_event(sock, event)
else:
logging.warn('can not find handler for fd %d',
sock.fileno())
now = time.time()
if now - last_time > 5:
# TODO sweep timeouts
last_time = now