You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
291 lines
10 KiB
291 lines
10 KiB
#!/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.
|
|
|
|
# SOCKS5 UDP Request
|
|
# +----+------+------+----------+----------+----------+
|
|
# |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA |
|
|
# +----+------+------+----------+----------+----------+
|
|
# | 2 | 1 | 1 | Variable | 2 | Variable |
|
|
# +----+------+------+----------+----------+----------+
|
|
|
|
# SOCKS5 UDP Response
|
|
# +----+------+------+----------+----------+----------+
|
|
# |RSV | FRAG | ATYP | DST.ADDR | DST.PORT | DATA |
|
|
# +----+------+------+----------+----------+----------+
|
|
# | 2 | 1 | 1 | Variable | 2 | Variable |
|
|
# +----+------+------+----------+----------+----------+
|
|
|
|
# shadowsocks UDP Request (before encrypted)
|
|
# +------+----------+----------+----------+
|
|
# | ATYP | DST.ADDR | DST.PORT | DATA |
|
|
# +------+----------+----------+----------+
|
|
# | 1 | Variable | 2 | Variable |
|
|
# +------+----------+----------+----------+
|
|
|
|
# shadowsocks UDP Response (before encrypted)
|
|
# +------+----------+----------+----------+
|
|
# | ATYP | DST.ADDR | DST.PORT | DATA |
|
|
# +------+----------+----------+----------+
|
|
# | 1 | Variable | 2 | Variable |
|
|
# +------+----------+----------+----------+
|
|
|
|
# shadowsocks UDP Request and Response (after encrypted)
|
|
# +-------+--------------+
|
|
# | IV | PAYLOAD |
|
|
# +-------+--------------+
|
|
# | Fixed | Variable |
|
|
# +-------+--------------+
|
|
|
|
# HOW TO NAME THINGS
|
|
# ------------------
|
|
# `dest` means destination server, which is from DST fields in the SOCKS5
|
|
# request
|
|
# `local` means local server of shadowsocks
|
|
# `remote` means remote server of shadowsocks
|
|
# `client` means UDP clients that connects to other servers
|
|
# `server` means the UDP server that handles user requests
|
|
|
|
|
|
import time
|
|
import threading
|
|
import socket
|
|
import logging
|
|
import struct
|
|
import encrypt
|
|
import eventloop
|
|
import lru_cache
|
|
import errno
|
|
|
|
|
|
BUF_SIZE = 65536
|
|
|
|
|
|
def parse_header(data):
|
|
addrtype = ord(data[0])
|
|
dest_addr = None
|
|
dest_port = None
|
|
header_length = 0
|
|
if addrtype == 1:
|
|
if len(data) >= 7:
|
|
dest_addr = socket.inet_ntoa(data[1:5])
|
|
dest_port = struct.unpack('>H', data[5:7])[0]
|
|
header_length = 7
|
|
else:
|
|
logging.warn('[udp] header is too short')
|
|
elif addrtype == 3:
|
|
if len(data) > 2:
|
|
addrlen = ord(data[1])
|
|
if len(data) >= 2 + addrlen:
|
|
dest_addr = data[2:2 + addrlen]
|
|
dest_port = struct.unpack('>H', data[2 + addrlen:4 +
|
|
addrlen])[0]
|
|
header_length = 4 + addrlen
|
|
else:
|
|
logging.warn('[udp] header is too short')
|
|
else:
|
|
logging.warn('[udp] header is too short')
|
|
elif addrtype == 4:
|
|
if len(data) >= 19:
|
|
dest_addr = socket.inet_ntop(socket.AF_INET6, data[1:17])
|
|
dest_port = struct.unpack('>H', data[17:19])[0]
|
|
header_length = 19
|
|
else:
|
|
logging.warn('[udp] header is too short')
|
|
else:
|
|
logging.warn('unsupported addrtype %d' % addrtype)
|
|
if dest_addr is None:
|
|
return None
|
|
return (addrtype, dest_addr, dest_port, header_length)
|
|
|
|
|
|
def client_key(a, b, c, d):
|
|
return '%s:%s:%s:%s' % (a, b, c, d)
|
|
|
|
|
|
class UDPRelay(object):
|
|
def __init__(self, listen_addr='127.0.0.1', listen_port=1080,
|
|
remote_addr='127.0.0.1', remote_port=8387, password=None,
|
|
method='table', timeout=300, is_local=True):
|
|
self._listen_addr = listen_addr
|
|
self._listen_port = listen_port
|
|
self._remote_addr = remote_addr
|
|
self._remote_port = remote_port
|
|
self._password = password
|
|
self._method = method
|
|
self._timeout = timeout
|
|
self._is_local = is_local
|
|
self._cache = lru_cache.LRUCache(timeout=timeout,
|
|
close_callback=self._close_client)
|
|
self._client_fd_to_server_addr = lru_cache.LRUCache(timeout=timeout)
|
|
self._closed = False
|
|
|
|
addrs = socket.getaddrinfo(self._listen_addr, self._listen_port, 0,
|
|
socket.SOCK_DGRAM, socket.SOL_UDP)
|
|
if len(addrs) == 0:
|
|
raise Exception("can't get addrinfo for %s:%d" %
|
|
(self._listen_addr, self._listen_port))
|
|
af, socktype, proto, canonname, sa = addrs[0]
|
|
server_socket = socket.socket(af, socktype, proto)
|
|
server_socket.bind((self._listen_addr, self._listen_port))
|
|
server_socket.setblocking(False)
|
|
self._server_socket = server_socket
|
|
|
|
def _close_client(self, client):
|
|
if hasattr(client, 'close'):
|
|
self._eventloop.remove(client)
|
|
client.close()
|
|
else:
|
|
# just an address
|
|
pass
|
|
|
|
def _handle_server(self):
|
|
server = self._server_socket
|
|
data, r_addr = server.recvfrom(BUF_SIZE)
|
|
if self._is_local:
|
|
frag = ord(data[2])
|
|
if frag != 0:
|
|
logging.warn('drop a message since frag is not 0')
|
|
return
|
|
else:
|
|
data = data[3:]
|
|
else:
|
|
# decrypt data
|
|
data = encrypt.encrypt_all(self._password, self._method, 0, data)
|
|
if not data:
|
|
return
|
|
header_result = parse_header(data)
|
|
if header_result is None:
|
|
return
|
|
addrtype, dest_addr, dest_port, header_length = header_result
|
|
|
|
if self._is_local:
|
|
server_addr, server_port = self._remote_addr, self._remote_port
|
|
else:
|
|
server_addr, server_port = dest_addr, dest_port
|
|
|
|
key = client_key(r_addr[0], r_addr[1], dest_addr, dest_port)
|
|
client = self._cache.get(key, None)
|
|
if not client:
|
|
# TODO async getaddrinfo
|
|
addrs = socket.getaddrinfo(server_addr, server_port, 0,
|
|
socket.SOCK_DGRAM, socket.SOL_UDP)
|
|
if addrs:
|
|
af, socktype, proto, canonname, sa = addrs[0]
|
|
client = socket.socket(af, socktype, proto)
|
|
client.setblocking(False)
|
|
self._cache[key] = client
|
|
self._client_fd_to_server_addr[client.fileno()] = r_addr
|
|
else:
|
|
# drop
|
|
return
|
|
self._eventloop.add(client, eventloop.POLL_IN)
|
|
|
|
data = data[header_length:]
|
|
if not data:
|
|
return
|
|
if self._is_local:
|
|
data = encrypt.encrypt_all(self._password, self._method, 1, data)
|
|
if not data:
|
|
return
|
|
try:
|
|
client.sendto(data, (server_addr, server_port))
|
|
except IOError as e:
|
|
err = eventloop.errno_from_exception(e)
|
|
if err in (errno.EINPROGRESS, errno.EAGAIN):
|
|
pass
|
|
else:
|
|
logging.error(e)
|
|
|
|
def _handle_client(self, sock):
|
|
data, r_addr = sock.recvfrom(BUF_SIZE)
|
|
if not self._is_local:
|
|
addrlen = len(r_addr[0])
|
|
if addrlen > 255:
|
|
# drop
|
|
return
|
|
data = '\x03' + chr(addrlen) + r_addr[0] + \
|
|
struct.pack('>H', r_addr[1]) + data
|
|
response = encrypt.encrypt_all(self._password, self._method, 1,
|
|
data)
|
|
if not response:
|
|
return
|
|
else:
|
|
data = encrypt.encrypt_all(self._password, self._method, 0,
|
|
data)
|
|
if not data:
|
|
return
|
|
header_result = parse_header(data)
|
|
if header_result is None:
|
|
return
|
|
# addrtype, dest_addr, dest_port, header_length = header_result
|
|
response = '\x00\x00\x00' + data
|
|
client_addr = self._client_fd_to_server_addr.get(sock.fileno(), None)
|
|
if client_addr:
|
|
self._server_socket.sendto(response, client_addr)
|
|
else:
|
|
# this packet is from somewhere else we know
|
|
# simply drop that packet
|
|
pass
|
|
|
|
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(10)
|
|
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:
|
|
self._handle_server()
|
|
else:
|
|
self._handle_client(sock)
|
|
now = time.time()
|
|
if now - last_time > 3.5:
|
|
self._cache.sweep()
|
|
if now - last_time > 7:
|
|
self._client_fd_to_server_addr.sweep()
|
|
last_time = now
|
|
|
|
def start(self):
|
|
if self._closed:
|
|
raise Exception('closed')
|
|
t = threading.Thread(target=self._run)
|
|
t.setName('UDPThread')
|
|
t.setDaemon(False)
|
|
t.start()
|
|
self._thread = t
|
|
|
|
def close(self):
|
|
self._closed = True
|
|
self._server_socket.close()
|
|
|
|
def thread(self):
|
|
return self._thread
|
|
|