#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright 2015 clowwindy
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from __future__ import absolute_import, division, print_function, \
with_statement
import time
import socket
import errno
import struct
import logging
import binascii
import traceback
import random
from shadowsocks import encrypt, obfs, eventloop, shell, common
from shadowsocks.common import pre_parse_header, parse_header
# set it 'True' if run as a local client and connect to a server which support new protocol
CLIENT_NEW_PROTOCOL = False #deprecated
# we clear at most TIMEOUTS_CLEAN_SIZE timeouts each time
TIMEOUTS_CLEAN_SIZE = 512
MSG_FASTOPEN = 0x20000000
# SOCKS command definition
CMD_CONNECT = 1
CMD_BIND = 2
CMD_UDP_ASSOCIATE = 3
# for each opening port, we have a TCP Relay
# for each connection, we have a TCP Relay Handler to handle the connection
# for each handler, we have 2 sockets:
# local: connected to the client
# remote: connected to remote server
# for each handler, it could be at one of several stages:
# as sslocal:
# stage 0 SOCKS hello received from local, send hello to local
# stage 1 addr received from local, query DNS for remote
# stage 2 UDP assoc
# stage 3 DNS resolved, connect to remote
# stage 4 still connecting, more data from local received
# stage 5 remote connected, piping local and remote
# as ssserver:
# stage 0 just jump to stage 1
# stage 1 addr received from local, query DNS for remote
# stage 3 DNS resolved, connect to remote
# stage 4 still connecting, more data from local received
# stage 5 remote connected, piping local and remote
STAGE_INIT = 0
STAGE_ADDR = 1
STAGE_UDP_ASSOC = 2
STAGE_DNS = 3
STAGE_CONNECTING = 4
STAGE_STREAM = 5
STAGE_DESTROYED = -1
# for each handler, we have 2 stream directions:
# upstream: from client to server direction
# read local and write to remote
# downstream: from server to client direction
# read remote and write to local
STREAM_UP = 0
STREAM_DOWN = 1
# for each stream, it's waiting for reading, or writing, or both
WAIT_STATUS_INIT = 0
WAIT_STATUS_READING = 1
WAIT_STATUS_WRITING = 2
WAIT_STATUS_READWRITING = WAIT_STATUS_READING | WAIT_STATUS_WRITING
BUF_SIZE = 32 * 1024
class TCPRelayHandler(object):
def __init__(self, server, fd_to_handlers, loop, local_sock, config,
dns_resolver, is_local):
self._server = server
self._fd_to_handlers = fd_to_handlers
self._loop = loop
self._local_sock = local_sock
self._remote_sock = None
self._remote_sock_v6 = None
self._remote_udp = False
self._config = config
self._dns_resolver = dns_resolver
# TCP Relay works as either sslocal or ssserver
# if is_local, this is sslocal
self._is_local = is_local
self._stage = STAGE_INIT
self._encryptor = encrypt.Encryptor(config['password'],
config['method'])
self._encrypt_correct = True
self._obfs = obfs.obfs(config['obfs'])
server_info = obfs.server_info(server.obfs_data)
server_info.host = config['server']
server_info.port = server._listen_port
server_info.tcp_mss = 1440
server_info.param = config['obfs_param']
self._obfs.set_server_info(server_info)
self._protocol = obfs.obfs(config['protocol'])
server_info = obfs.server_info(server.protocol_data)
server_info.host = config['server']
server_info.port = server._listen_port
server_info.tcp_mss = 1440
server_info.param = ''
self._protocol.set_server_info(server_info)
self._fastopen_connected = False
self._data_to_write_to_local = []
self._data_to_write_to_remote = []
self._udp_data_send_buffer = b''
self._upstream_status = WAIT_STATUS_READING
self._downstream_status = WAIT_STATUS_INIT
self._client_address = local_sock.getpeername()[:2]
self._remote_address = None
if 'forbidden_ip' in config:
self._forbidden_iplist = config['forbidden_ip']
else:
self._forbidden_iplist = None
if is_local:
self._chosen_server = self._get_a_server()
fd_to_handlers[local_sock.fileno()] = self
local_sock.setblocking(False)
local_sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
loop.add(local_sock, eventloop.POLL_IN | eventloop.POLL_ERR,
self._server)
self.last_activity = 0
self._update_activity()
self._server.add_connection(1)
def __hash__(self):
# default __hash__ is id / 16
# we want to eliminate collisions
return id(self)
@property
def remote_address(self):
return self._remote_address
def _get_a_server(self):
server = self._config['server']
server_port = self._config['server_port']
if type(server_port) == list:
server_port = random.choice(server_port)
if type(server) == list:
server = random.choice(server)
logging.debug('chosen server: %s:%d', server, server_port)
return server, server_port
def _update_activity(self, data_len=0):
# tell the TCP Relay we have activities recently
# else it will think we are inactive and timed out
self._server.update_activity(self, data_len)
def _update_stream(self, stream, status):
# update a stream to a new waiting status
# check if status is changed
# only update if dirty
dirty = False
if stream == STREAM_DOWN:
if self._downstream_status != status:
self._downstream_status = status
dirty = True
elif stream == STREAM_UP:
if self._upstream_status != status:
self._upstream_status = status
dirty = True
if dirty:
if self._local_sock:
event = eventloop.POLL_ERR
if self._downstream_status & WAIT_STATUS_WRITING:
event |= eventloop.POLL_OUT
if self._upstream_status & WAIT_STATUS_READING:
event |= eventloop.POLL_IN
self._loop.modify(self._local_sock, event)
if self._remote_sock:
event = eventloop.POLL_ERR
if self._downstream_status & WAIT_STATUS_READING:
event |= eventloop.POLL_IN
if self._upstream_status & WAIT_STATUS_WRITING:
event |= eventloop.POLL_OUT
self._loop.modify(self._remote_sock, event)
if self._remote_sock_v6:
self._loop.modify(self._remote_sock_v6, event)
def _write_to_sock(self, data, sock):
# write data to sock
# if only some of the data are written, put remaining in the buffer
# and update the stream to wait for writing
if not sock:
return False
#logging.debug("_write_to_sock %s %s %s" % (self._remote_sock, sock, self._remote_udp))
uncomplete = False
if self._remote_udp and sock == self._remote_sock:
try:
self._udp_data_send_buffer += data
#logging.info('UDP over TCP sendto %d %s' % (len(data), binascii.hexlify(data)))
while len(self._udp_data_send_buffer) > 6:
length = struct.unpack('>H', self._udp_data_send_buffer[:2])[0]
if length > len(self._udp_data_send_buffer):
break
data = self._udp_data_send_buffer[:length]
self._udp_data_send_buffer = self._udp_data_send_buffer[length:]
frag = common.ord(data[2])
if frag != 0:
logging.warn('drop a message since frag is %d' % (frag,))
continue
else:
data = data[3:]
header_result = parse_header(data)
if header_result is None:
continue
connecttype, dest_addr, dest_port, header_length = header_result
addrs = socket.getaddrinfo(dest_addr, dest_port, 0,
socket.SOCK_DGRAM, socket.SOL_UDP)
#logging.info('UDP over TCP sendto %s:%d %d bytes from %s:%d' % (dest_addr, dest_port, len(data), self._client_address[0], self._client_address[1]))
if addrs:
af, socktype, proto, canonname, server_addr = addrs[0]
data = data[header_length:]
if af == socket.AF_INET6:
self._remote_sock_v6.sendto(data, (server_addr[0], dest_port))
else:
sock.sendto(data, (server_addr[0], dest_port))
except Exception as e:
#trace = traceback.format_exc()
#logging.error(trace)
error_no = eventloop.errno_from_exception(e)
if error_no in (errno.EAGAIN, errno.EINPROGRESS,
errno.EWOULDBLOCK):
uncomplete = True
else:
shell.print_exception(e)
self.destroy()
return False
return True
else:
try:
if self._is_local:
pass
else:
if sock == self._local_sock and self._encrypt_correct:
obfs_encode = self._obfs.server_encode(data)
data = obfs_encode
if data:
l = len(data)
s = sock.send(data)
if s < l:
data = data[s:]
uncomplete = True
else:
return
except (OSError, IOError) as e:
error_no = eventloop.errno_from_exception(e)
if error_no in (errno.EAGAIN, errno.EINPROGRESS,
errno.EWOULDBLOCK):
uncomplete = True
else:
#traceback.print_exc()
shell.print_exception(e)
self.destroy()
return False
except Exception as e:
shell.print_exception(e)
self.destroy()
return False
if uncomplete:
if sock == self._local_sock:
self._data_to_write_to_local.append(data)
self._update_stream(STREAM_DOWN, WAIT_STATUS_WRITING)
elif sock == self._remote_sock:
self._data_to_write_to_remote.append(data)
self._update_stream(STREAM_UP, WAIT_STATUS_WRITING)
else:
logging.error('write_all_to_sock:unknown socket')
else:
if sock == self._local_sock:
self._update_stream(STREAM_DOWN, WAIT_STATUS_READING)
elif sock == self._remote_sock:
self._update_stream(STREAM_UP, WAIT_STATUS_READING)
else:
logging.error('write_all_to_sock:unknown socket')
return True
def _get_redirect_host(self, client_address, ogn_data):
# test
host_list = [(b"www.bing.com", 80), (b"www.microsoft.com", 80), (b"cloudfront.com", 80), (b"cloudflare.com", 80), (b"1.2.3.4", 1000), (b"0.0.0.0", 0)]
hash_code = binascii.crc32(ogn_data)
addrs = socket.getaddrinfo(client_address[0], client_address[1], 0, socket.SOCK_STREAM, socket.SOL_TCP)
af, socktype, proto, canonname, sa = addrs[0]
address_bytes = common.inet_pton(af, sa[0])
if len(address_bytes) == 16:
addr = struct.unpack('>Q', address_bytes[8:])[0]
if len(address_bytes) == 4:
addr = struct.unpack('>I', address_bytes)[0]
else:
addr = 0
return host_list[((hash_code & 0xffffffff) + addr + 3) % len(host_list)]
def _handel_protocol_error(self, client_address, ogn_data):
#raise Exception('can not parse header')
logging.warn("Protocol ERROR, TCP ogn data %s from %s:%d" % (binascii.hexlify(ogn_data), client_address[0], client_address[1]))
self._encrypt_correct = False
#create redirect or disconnect by hash code
host, port = self._get_redirect_host(client_address, ogn_data)
data = b"\x03" + common.chr(len(host)) + host + struct.pack('>H', port)
logging.warn("TCP data redir %s:%d %s" % (host, port, binascii.hexlify(data)))
return data + ogn_data
def _handle_stage_connecting(self, data):
if self._is_local:
data = self._protocol.client_pre_encrypt(data)
data = self._encryptor.encrypt(data)
data = self._obfs.client_encode(data)
if data:
self._data_to_write_to_remote.append(data)
if self._is_local and not self._fastopen_connected and \
self._config['fast_open']:
# for sslocal and fastopen, we basically wait for data and use
# sendto to connect
try:
# only connect once
self._fastopen_connected = True
remote_sock = \
self._create_remote_socket(self._chosen_server[0],
self._chosen_server[1])
self._loop.add(remote_sock, eventloop.POLL_ERR, self._server)
data = b''.join(self._data_to_write_to_remote)
l = len(data)
s = remote_sock.sendto(data, MSG_FASTOPEN, self._chosen_server)
if s < l:
data = data[s:]
self._data_to_write_to_remote = [data]
else:
self._data_to_write_to_remote = []
self._update_stream(STREAM_UP, WAIT_STATUS_READWRITING)
except (OSError, IOError) as e:
if eventloop.errno_from_exception(e) == errno.EINPROGRESS:
# in this case data is not sent at all
self._update_stream(STREAM_UP, WAIT_STATUS_READWRITING)
elif eventloop.errno_from_exception(e) == errno.ENOTCONN:
logging.error('fast open not supported on this OS')
self._config['fast_open'] = False
self.destroy()
else:
shell.print_exception(e)
if self._config['verbose']:
traceback.print_exc()
self.destroy()
def _handle_stage_addr(self, ogn_data, data):
try:
if self._is_local:
cmd = common.ord(data[1])
if cmd == CMD_UDP_ASSOCIATE:
logging.debug('UDP associate')
if self._local_sock.family == socket.AF_INET6:
header = b'\x05\x00\x00\x04'
else:
header = b'\x05\x00\x00\x01'
addr, port = self._local_sock.getsockname()[:2]
addr_to_send = socket.inet_pton(self._local_sock.family,
addr)
port_to_send = struct.pack('>H', port)
self._write_to_sock(header + addr_to_send + port_to_send,
self._local_sock)
self._stage = STAGE_UDP_ASSOC
# just wait for the client to disconnect
return
elif cmd == CMD_CONNECT:
# just trim VER CMD RSV
data = data[3:]
else:
logging.error('unknown command %d', cmd)
self.destroy()
return
before_parse_data = data
if self._is_local:
header_result = parse_header(data)
else:
data = pre_parse_header(data)
if data is None:
data = self._handel_protocol_error(self._client_address, ogn_data)
header_result = parse_header(data)
if header_result is None:
data = self._handel_protocol_error(self._client_address, ogn_data)
header_result = parse_header(data)
connecttype, remote_addr, remote_port, header_length = header_result
logging.info('%s connecting %s:%d from %s:%d' %
((connecttype == 0) and 'TCP' or 'UDP',
common.to_str(remote_addr), remote_port,
self._client_address[0], self._client_address[1]))
self._remote_address = (common.to_str(remote_addr), remote_port)
self._remote_udp = (connecttype != 0)
# pause reading
self._update_stream(STREAM_UP, WAIT_STATUS_WRITING)
self._stage = STAGE_DNS
if self._is_local:
# forward address to remote
self._write_to_sock((b'\x05\x00\x00\x01'
b'\x00\x00\x00\x00\x10\x10'),
self._local_sock)
if CLIENT_NEW_PROTOCOL:
rnd_len = random.randint(1, 32)
total_len = 7 + rnd_len + len(data)
data = b'\x88' + struct.pack('>H', total_len) + chr(rnd_len) + (b' ' * (rnd_len - 1)) + data
crc = (0xffffffff - binascii.crc32(data)) & 0xffffffff
data += struct.pack('<I', crc)
data = self._protocol.client_pre_encrypt(data)
data_to_send = self._encryptor.encrypt(data)
data_to_send = self._obfs.client_encode(data_to_send)
if data_to_send:
self._data_to_write_to_remote.append(data_to_send)
# notice here may go into _handle_dns_resolved directly
self._dns_resolver.resolve(self._chosen_server[0],
self._handle_dns_resolved)
else:
if len(data) > header_length:
self._data_to_write_to_remote.append(data[header_length:])
# notice here may go into _handle_dns_resolved directly
self._dns_resolver.resolve(remote_addr,
self._handle_dns_resolved)
except Exception as e:
self._log_error(e)
if self._config['verbose']:
traceback.print_exc()
self.destroy()
def _create_remote_socket(self, ip, port):
if self._remote_udp:
addrs_v6 = socket.getaddrinfo("::", 0, 0, socket.SOCK_DGRAM, socket.SOL_UDP)
addrs = socket.getaddrinfo("0.0.0.0", 0, 0, socket.SOCK_DGRAM, socket.SOL_UDP)
else:
addrs = socket.getaddrinfo(ip, port, 0, socket.SOCK_STREAM, socket.SOL_TCP)
if len(addrs) == 0:
raise Exception("getaddrinfo failed for %s:%d" % (ip, port))
af, socktype, proto, canonname, sa = addrs[0]
if self._forbidden_iplist:
if common.to_str(sa[0]) in self._forbidden_iplist:
raise Exception('IP %s is in forbidden list, reject' %
common.to_str(sa[0]))
remote_sock = socket.socket(af, socktype, proto)
self._remote_sock = remote_sock
self._fd_to_handlers[remote_sock.fileno()] = self
if self._remote_udp:
af, socktype, proto, canonname, sa = addrs_v6[0]
remote_sock_v6 = socket.socket(af, socktype, proto)
self._remote_sock_v6 = remote_sock_v6
self._fd_to_handlers[remote_sock_v6.fileno()] = self
remote_sock.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 1024 * 32)
remote_sock.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 1024 * 32)
remote_sock_v6.setsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF, 1024 * 32)
remote_sock_v6.setsockopt(socket.SOL_SOCKET, socket.SO_SNDBUF, 1024 * 32)
remote_sock.setblocking(False)
if self._remote_udp:
remote_sock_v6.setblocking(False)
else:
remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1)
return remote_sock
def _handle_dns_resolved(self, result, error):
if error:
self._log_error(error)
self.destroy()
return
if result:
ip = result[1]
if ip:
try:
self._stage = STAGE_CONNECTING
remote_addr = ip
if self._is_local:
remote_port = self._chosen_server[1]
else:
remote_port = self._remote_address[1]
if self._is_local and self._config['fast_open']:
# for fastopen:
# wait for more data to arrive and send them in one SYN
self._stage = STAGE_CONNECTING
# we don't have to wait for remote since it's not
# created
self._update_stream(STREAM_UP, WAIT_STATUS_READING)
# TODO when there is already data in this packet
else:
# else do connect
remote_sock = self._create_remote_socket(remote_addr,
remote_port)
if self._remote_udp:
self._loop.add(remote_sock,
eventloop.POLL_IN,
self._server)
if self._remote_sock_v6:
self._loop.add(self._remote_sock_v6,
eventloop.POLL_IN,
self._server)
else:
try:
remote_sock.connect((remote_addr, remote_port))
except (OSError, IOError) as e:
if eventloop.errno_from_exception(e) in (errno.EINPROGRESS,
errno.EWOULDBLOCK):
pass # always goto here
else:
raise e
self._loop.add(remote_sock,
eventloop.POLL_ERR | eventloop.POLL_OUT,
self._server)
self._stage = STAGE_CONNECTING
self._update_stream(STREAM_UP, WAIT_STATUS_READWRITING)
self._update_stream(STREAM_DOWN, WAIT_STATUS_READING)
if self._remote_udp:
while self._data_to_write_to_remote:
data = self._data_to_write_to_remote[0]
del self._data_to_write_to_remote[0]
self._write_to_sock(data, self._remote_sock)
return
except Exception as e:
shell.print_exception(e)
if self._config['verbose']:
traceback.print_exc()
self.destroy()
def _on_local_read(self):
# handle all local read events and dispatch them to methods for
# each stage
if not self._local_sock:
return
is_local = self._is_local
data = None
try:
data = self._local_sock.recv(BUF_SIZE)
except (OSError, IOError) as e:
if eventloop.errno_from_exception(e) in \
(errno.ETIMEDOUT, errno.EAGAIN, errno.EWOULDBLOCK):
return
if not data:
self.destroy()
return
ogn_data = data
self._update_activity(len(data))
if not is_local:
if self._encrypt_correct:
obfs_decode = self._obfs.server_decode(data)
if obfs_decode[2]:
self._write_to_sock(b'', self._local_sock)
if obfs_decode[1]:
data = self._encryptor.decrypt(obfs_decode[0])
else:
data = obfs_decode[0]
try:
data = self._protocol.server_post_decrypt(data)
except Exception as e:
shell.print_exception(e)
self.destroy()
if not data:
return
self._server.server_transfer_ul += len(data)
if self._stage == STAGE_STREAM:
if self._is_local:
data = self._protocol.client_pre_encrypt(data)
data = self._encryptor.encrypt(data)
data = self._obfs.client_encode(data)
self._write_to_sock(data, self._remote_sock)
return
elif is_local and self._stage == STAGE_INIT:
# TODO check auth method
self._write_to_sock(b'\x05\00', self._local_sock)
self._stage = STAGE_ADDR
return
elif self._stage == STAGE_CONNECTING:
self._handle_stage_connecting(data)
elif (is_local and self._stage == STAGE_ADDR) or \
(not is_local and self._stage == STAGE_INIT):
self._handle_stage_addr(ogn_data, data)
def _on_remote_read(self, is_remote_sock):
# handle all remote read events
data = None
try:
if self._remote_udp:
if is_remote_sock:
data, addr = self._remote_sock.recvfrom(BUF_SIZE)
else:
data, addr = self._remote_sock_v6.recvfrom(BUF_SIZE)
port = struct.pack('>H', addr[1])
try:
ip = socket.inet_aton(addr[0])
data = b'\x00\x01' + ip + port + data
except Exception as e:
ip = socket.inet_pton(socket.AF_INET6, addr[0])
data = b'\x00\x04' + ip + port + data
data = struct.pack('>H', len(data) + 2) + data
#logging.info('UDP over TCP recvfrom %s:%d %d bytes to %s:%d' % (addr[0], addr[1], len(data), self._client_address[0], self._client_address[1]))
else:
data = self._remote_sock.recv(BUF_SIZE)
except (OSError, IOError) as e:
if eventloop.errno_from_exception(e) in \
(errno.ETIMEDOUT, errno.EAGAIN, errno.EWOULDBLOCK, 10035): #errno.WSAEWOULDBLOCK
return
if not data:
self.destroy()
return
self._server.server_transfer_dl += len(data)
self._update_activity(len(data))
if self._is_local:
obfs_decode = self._obfs.client_decode(data)
if obfs_decode[1]:
send_back = self._obfs.client_encode(b'')
self._write_to_sock(send_back, self._remote_sock)
data = self._encryptor.decrypt(obfs_decode[0])
data = self._protocol.client_post_decrypt(data)
else:
if self._encrypt_correct:
data = self._protocol.server_pre_encrypt(data)
data = self._encryptor.encrypt(data)
try:
self._write_to_sock(data, self._local_sock)
except Exception as e:
shell.print_exception(e)
if self._config['verbose']:
traceback.print_exc()
# TODO use logging when debug completed
self.destroy()
def _on_local_write(self):
# handle local writable event
if self._data_to_write_to_local:
data = b''.join(self._data_to_write_to_local)
self._data_to_write_to_local = []
self._write_to_sock(data, self._local_sock)
else:
self._update_stream(STREAM_DOWN, WAIT_STATUS_READING)
def _on_remote_write(self):
# handle remote writable event
self._stage = STAGE_STREAM
if self._data_to_write_to_remote:
data = b''.join(self._data_to_write_to_remote)
self._data_to_write_to_remote = []
self._write_to_sock(data, self._remote_sock)
else:
self._update_stream(STREAM_UP, WAIT_STATUS_READING)
def _on_local_error(self):
logging.debug('got local error')
if self._local_sock:
logging.error(eventloop.get_sock_error(self._local_sock))
self.destroy()
def _on_remote_error(self):
logging.debug('got remote error')
if self._remote_sock:
logging.error(eventloop.get_sock_error(self._remote_sock))
self.destroy()
def handle_event(self, sock, event):
# handle all events in this handler and dispatch them to methods
if self._stage == STAGE_DESTROYED:
logging.debug('ignore handle_event: destroyed')
return
# order is important
if sock == self._remote_sock or sock == self._remote_sock_v6:
if event & eventloop.POLL_ERR:
self._on_remote_error()
if self._stage == STAGE_DESTROYED:
return
if event & (eventloop.POLL_IN | eventloop.POLL_HUP):
self._on_remote_read(sock == self._remote_sock)
if self._stage == STAGE_DESTROYED:
return
if event & eventloop.POLL_OUT:
self._on_remote_write()
elif sock == self._local_sock:
if event & eventloop.POLL_ERR:
self._on_local_error()
if self._stage == STAGE_DESTROYED:
return
if event & (eventloop.POLL_IN | eventloop.POLL_HUP):
self._on_local_read()
if self._stage == STAGE_DESTROYED:
return
if event & eventloop.POLL_OUT:
self._on_local_write()
else:
logging.warn('unknown socket')
def _log_error(self, e):
logging.error('%s when handling connection from %s:%d' %
(e, self._client_address[0], self._client_address[1]))
def destroy(self):
# destroy the handler and release any resources
# promises:
# 1. destroy won't make another destroy() call inside
# 2. destroy releases resources so it prevents future call to destroy
# 3. destroy won't raise any exceptions
# if any of the promises are broken, it indicates a bug has been
# introduced! mostly likely memory leaks, etc
if self._stage == STAGE_DESTROYED:
# this couldn't happen
logging.debug('already destroyed')
return
self._stage = STAGE_DESTROYED
if self._remote_address:
logging.debug('destroy: %s:%d' %
self._remote_address)
else:
logging.debug('destroy')
if self._remote_sock:
logging.debug('destroying remote')
try:
self._loop.remove(self._remote_sock)
except Exception as e:
pass
del self._fd_to_handlers[self._remote_sock.fileno()]
self._remote_sock.close()
self._remote_sock = None
if self._remote_sock_v6:
logging.debug('destroying remote')
try:
self._loop.remove(self._remote_sock_v6)
except Exception as e:
pass
del self._fd_to_handlers[self._remote_sock_v6.fileno()]
self._remote_sock_v6.close()
self._remote_sock_v6 = None
if self._local_sock:
logging.debug('destroying local')
self._loop.remove(self._local_sock)
del self._fd_to_handlers[self._local_sock.fileno()]
self._local_sock.close()
self._local_sock = None
if self._obfs:
self._obfs.dispose()
self._obfs = None
if self._protocol:
self._protocol.dispose()
self._protocol = None
self._dns_resolver.remove_callback(self._handle_dns_resolved)
self._server.remove_handler(self)
self._server.add_connection(-1)
class TCPRelay(object):
def __init__(self, config, dns_resolver, is_local, stat_callback=None):
self._config = config
self._is_local = is_local
self._dns_resolver = dns_resolver
self._closed = False
self._eventloop = None
self._fd_to_handlers = {}
self.server_transfer_ul = 0
self.server_transfer_dl = 0
self.server_connections = 0
self.protocol_data = obfs.obfs(config['protocol']).init_data()
self.obfs_data = obfs.obfs(config['obfs']).init_data()
self._timeout = config['timeout']
self._timeouts = [] # a list for all the handlers
# we trim the timeouts once a while
self._timeout_offset = 0 # last checked position for timeout
self._handler_to_timeouts = {} # key: handler value: index in timeouts
if is_local:
listen_addr = config['local_address']
listen_port = config['local_port']
else:
listen_addr = config['server']
listen_port = config['server_port']
self._listen_port = listen_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.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind(sa)
server_socket.setblocking(False)
if config['fast_open']:
try:
server_socket.setsockopt(socket.SOL_TCP, 23, 5)
except socket.error:
logging.error('warning: fast open is not available')
self._config['fast_open'] = False
server_socket.listen(1024)
self._server_socket = server_socket
self._stat_callback = stat_callback
def add_to_loop(self, loop):
if self._eventloop:
raise Exception('already add to loop')
if self._closed:
raise Exception('already closed')
self._eventloop = loop
self._eventloop.add(self._server_socket,
eventloop.POLL_IN | eventloop.POLL_ERR, self)
self._eventloop.add_periodic(self.handle_periodic)
def remove_handler(self, handler):
index = self._handler_to_timeouts.get(hash(handler), -1)
if index >= 0:
# delete is O(n), so we just set it to None
self._timeouts[index] = None
del self._handler_to_timeouts[hash(handler)]
def add_connection(self, val):
self.server_connections += val
logging.debug('server port %5d connections = %d' % (self._listen_port, self.server_connections,))
def update_activity(self, handler, data_len):
if data_len and self._stat_callback:
self._stat_callback(self._listen_port, data_len)
# set handler to active
now = int(time.time())
if now - handler.last_activity < eventloop.TIMEOUT_PRECISION:
# thus we can lower timeout modification frequency
return
handler.last_activity = now
index = self._handler_to_timeouts.get(hash(handler), -1)
if index >= 0:
# delete is O(n), so we just set it to None
self._timeouts[index] = None
length = len(self._timeouts)
self._timeouts.append(handler)
self._handler_to_timeouts[hash(handler)] = length
def _sweep_timeout(self):
# tornado's timeout memory management is more flexible than we need
# we just need a sorted last_activity queue and it's faster than heapq
# in fact we can do O(1) insertion/remove so we invent our own
if self._timeouts:
logging.log(shell.VERBOSE_LEVEL, 'sweeping timeouts')
now = time.time()
length = len(self._timeouts)
pos = self._timeout_offset
while pos < length:
handler = self._timeouts[pos]
if handler:
if now - handler.last_activity < self._timeout:
break
else:
if handler.remote_address:
logging.warn('timed out: %s:%d' %
handler.remote_address)
else:
logging.warn('timed out')
handler.destroy()
self._timeouts[pos] = None # free memory
pos += 1
else:
pos += 1
if pos > TIMEOUTS_CLEAN_SIZE and pos > length >> 1:
# clean up the timeout queue when it gets larger than half
# of the queue
self._timeouts = self._timeouts[pos:]
for key in self._handler_to_timeouts:
self._handler_to_timeouts[key] -= pos
pos = 0
self._timeout_offset = pos
def handle_event(self, sock, fd, event):
# handle events and dispatch to handlers
if sock:
logging.log(shell.VERBOSE_LEVEL, 'fd %d %s', fd,
eventloop.EVENT_NAMES.get(event, event))
if sock == self._server_socket:
if event & eventloop.POLL_ERR:
# TODO
raise Exception('server_socket error')
try:
logging.debug('accept')
conn = self._server_socket.accept()
TCPRelayHandler(self, self._fd_to_handlers,
self._eventloop, conn[0], self._config,
self._dns_resolver, self._is_local)
except (OSError, IOError) as e:
error_no = eventloop.errno_from_exception(e)
if error_no in (errno.EAGAIN, errno.EINPROGRESS,
errno.EWOULDBLOCK):
return
else:
shell.print_exception(e)
if self._config['verbose']:
traceback.print_exc()
else:
if sock:
handler = self._fd_to_handlers.get(fd, None)
if handler:
handler.handle_event(sock, event)
else:
logging.warn('poll removed fd')
def handle_periodic(self):
if self._closed:
if self._server_socket:
self._eventloop.remove(self._server_socket)
self._server_socket.close()
self._server_socket = None
logging.info('closed TCP port %d', self._listen_port)
if not self._fd_to_handlers:
logging.info('stopping')
self._eventloop.stop()
self._sweep_timeout()
def close(self, next_tick=False):
logging.debug('TCP close')
self._closed = True
if not next_tick:
if self._eventloop:
self._eventloop.remove_periodic(self.handle_periodic)
self._eventloop.remove(self._server_socket)
self._server_socket.close()
for handler in list(self._fd_to_handlers.values()):
handler.destroy()
