#!/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 import platform from shadowsocks import encrypt, obfs, eventloop, shell, common from shadowsocks.common import pre_parse_header, parse_header # 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 UDP_MAX_BUF_SIZE = 65536 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 try: self._encryptor = encrypt.Encryptor(config['password'], config['method']) except Exception: self._stage = STAGE_DESTROYED logging.error('creater encryptor fail at port %d', server._listen_port) return 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.protocol_param = '' server_info.obfs_param = config['obfs_param'] server_info.iv = self._encryptor.cipher_iv server_info.recv_iv = b'' server_info.key = self._encryptor.cipher_key server_info.head_len = 30 server_info.tcp_mss = 1440 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.protocol_param = config['protocol_param'] server_info.obfs_param = '' server_info.iv = self._encryptor.cipher_iv server_info.recv_iv = b'' server_info.key = self._encryptor.cipher_key server_info.head_len = 30 server_info.tcp_mss = 1440 self._protocol.set_server_info(server_info) self._redir_list = config.get('redirect', ["0.0.0.0:0"]) self._bind = config.get('out_bind', '') self._bindv6 = config.get('out_bindv6', '') self._ignore_bind_list = config.get('ignore_bind', []) 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._accept_address = local_sock.getsockname()[:2] self._remote_address = None if 'forbidden_ip' in config: self._forbidden_iplist = config['forbidden_ip'] else: self._forbidden_iplist = None if 'forbidden_port' in config: self._forbidden_portset = config['forbidden_port'] else: self._forbidden_portset = 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) self._server.stat_add(self._client_address[0], 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 >= 0xff00: length = struct.unpack('>H', self._udp_data_send_buffer[1:3])[0] + 0xff00 if length > len(self._udp_data_send_buffer): break data = self._udp_data_send_buffer[:length] if length >= 0xff00: data = data[1:] 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) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() return False return True else: try: if self._encrypt_correct: if sock == self._remote_sock: self._server.server_transfer_ul += len(data) self._update_activity(len(data)) 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) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() return False except Exception as e: shell.print_exception(e) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) 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 from %s:%d' % (self._client_address[0], self._client_address[1])) 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 from %s:%d' % (self._client_address[0], self._client_address[1])) return True def _get_redirect_host(self, client_address, ogn_data): host_list = self._redir_list or ["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 af == socket.AF_INET6: addr = struct.unpack('>Q', address_bytes[8:])[0] elif af == socket.AF_INET: addr = struct.unpack('>I', address_bytes)[0] else: addr = 0 host_port = [] match_port = False if type(host_list) != list: host_list = [host_list] for host in host_list: items = common.to_str(host).rsplit(':', 1) if len(items) > 1: try: port = int(items[1]) if port == self._server._listen_port: match_port = True host_port.append((items[0], port)) except: pass else: host_port.append((host, 80)) if match_port: last_host_port = host_port host_port = [] for host in last_host_port: if host[1] == self._server._listen_port: host_port.append(host) return host_port[((hash_code & 0xffffffff) + addr) % len(host_port)] def _handel_protocol_error(self, client_address, ogn_data): logging.warn("Protocol ERROR, TCP ogn data %s from %s:%d via port %d" % (binascii.hexlify(ogn_data), client_address[0], client_address[1], self._server._listen_port)) self._encrypt_correct = False #create redirect or disconnect by hash code host, port = self._get_redirect_host(client_address, ogn_data) if port == 0: raise Exception('can not parse header') data = b"\x03" + common.to_bytes(common.chr(len(host))) + common.to_bytes(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: if self._encryptor is not None: 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() logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() def _get_head_size(self, buf, def_value): if len(buf) < 2: return def_value head_type = common.ord(buf[0]) & 0xF if head_type == 1: return 7 if head_type == 4: return 19 if head_type == 3: return 4 + common.ord(buf[1]) return def_value 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 not None: try: common.to_str(header_result[1]) except Exception as e: header_result = None 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 common.connect_log('%s connecting %s:%d via port %d' % ((connecttype == 0) and 'TCP' or 'UDP', common.to_str(remote_addr), remote_port, self._server._listen_port)) 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) head_len = self._get_head_size(data, 30) self._obfs.obfs.server_info.head_len = head_len self._protocol.obfs.server_info.head_len = head_len if self._encryptor is not None: 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 not self._remote_udp: if self._forbidden_iplist: if common.to_str(sa[0]) in self._forbidden_iplist: if self._remote_address: raise Exception('IP %s is in forbidden list, when connect to %s:%d via port %d' % (common.to_str(sa[0]), self._remote_address[0], self._remote_address[1], self._server._listen_port)) raise Exception('IP %s is in forbidden list, reject' % common.to_str(sa[0])) if self._forbidden_portset: if sa[1] in self._forbidden_portset: if self._remote_address: raise Exception('Port %d is in forbidden list, when connect to %s:%d via port %d' % (sa[1], self._remote_address[0], self._remote_address[1], self._server._listen_port)) raise Exception('Port %d is in forbidden list, reject' % sa[1]) 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.setblocking(False) if self._remote_udp: remote_sock_v6.setblocking(False) else: remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_NODELAY, 1) remote_sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1) if platform.system() in ['Linux']: remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_KEEPIDLE, 120) remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_KEEPINTVL, 20) remote_sock.setsockopt(socket.SOL_TCP, socket.TCP_KEEPCNT, 5) if not self._is_local: bind_addr = '' if self._bind and af == socket.AF_INET: bind_addr = self._bind elif self._bindv6 and af == socket.AF_INET6: bind_addr = self._bindv6 else: bind_addr = self._accept_address[0] bind_addr = bind_addr.replace("::ffff:", "") if bind_addr in self._ignore_bind_list: bind_addr = None if bind_addr: local_addrs = socket.getaddrinfo(bind_addr, port, 0, socket.SOCK_STREAM, socket.SOL_TCP) if local_addrs[0][0] == af: logging.debug("bind %s" % (bind_addr,)) remote_sock.bind((bind_addr, 0)) 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() logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) 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 if not is_local: if self._encryptor is not None: if self._encrypt_correct: try: obfs_decode = self._obfs.server_decode(data) except Exception as e: shell.print_exception(e) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() return if obfs_decode[2]: data = self._obfs.server_encode(b'') self._write_to_sock(data, self._local_sock) if obfs_decode[1]: if not self._protocol.obfs.server_info.recv_iv: iv_len = len(self._protocol.obfs.server_info.iv) self._protocol.obfs.server_info.recv_iv = obfs_decode[0][:iv_len] data = self._encryptor.decrypt(obfs_decode[0]) else: data = obfs_decode[0] try: data, sendback = self._protocol.server_post_decrypt(data) if sendback: backdata = self._protocol.server_pre_encrypt(b'') backdata = self._encryptor.encrypt(backdata) backdata = self._obfs.server_encode(backdata) try: self._write_to_sock(backdata, self._local_sock) except Exception as e: shell.print_exception(e) if self._config['verbose']: traceback.print_exc() logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() return except Exception as e: shell.print_exception(e) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() else: return if not data: return if self._stage == STAGE_STREAM: if self._is_local: if self._encryptor is not None: 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(UDP_MAX_BUF_SIZE) else: data, addr = self._remote_sock_v6.recvfrom(UDP_MAX_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 size = len(data) + 2 if size >= 0xff00: data = common.chr(0xff) + struct.pack('>H', size - 0xff00 + 1) + data else: data = struct.pack('>H', size) + 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 if self._encryptor is not None: if self._is_local: try: obfs_decode = self._obfs.client_decode(data) except Exception as e: shell.print_exception(e) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() return if obfs_decode[1]: send_back = self._obfs.client_encode(b'') self._write_to_sock(send_back, self._remote_sock) if not self._protocol.obfs.server_info.recv_iv: iv_len = len(self._protocol.obfs.server_info.iv) self._protocol.obfs.server_info.recv_iv = obfs_decode[0][:iv_len] data = self._encryptor.decrypt(obfs_decode[0]) try: data = self._protocol.client_post_decrypt(data) except Exception as e: shell.print_exception(e) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) self.destroy() return else: if self._encrypt_correct: data = self._protocol.server_pre_encrypt(data) data = self._encryptor.encrypt(data) data = self._obfs.server_encode(data) self._update_activity(len(data)) self._server.server_transfer_dl += len(data) else: return try: self._write_to_sock(data, self._local_sock) except Exception as e: shell.print_exception(e) if self._config['verbose']: traceback.print_exc() logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) 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)) logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) 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)) if self._remote_address: logging.error("when connect to %s:%d" % (self._remote_address[0], self._remote_address[1])) else: logging.error("exception from %s:%d" % (self._client_address[0], self._client_address[1])) 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 from %s:%d' % (self._client_address[0], self._client_address[1])) def _log_error(self, e): logging.error('%s when handling connection from %s:%d' % (e, self._client_address[0], self._client_address[1])) def stage(self): return self._stage 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._encryptor = None self._dns_resolver.remove_callback(self._handle_dns_resolved) self._server.remove_handler(self) self._server.add_connection(-1) self._server.stat_add(self._client_address[0], -1) class TCPRelay(object): def __init__(self, config, dns_resolver, is_local, stat_callback=None, stat_counter=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() if config.get('connect_verbose_info', 0) > 0: common.connect_log = logging.info 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(config.get('max_connect', 1024)) self._server_socket = server_socket self._stat_counter = stat_counter 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_stat(self, port, stat_dict, val): newval = stat_dict.get(0, 0) + val stat_dict[0] = newval logging.debug('port %d connections %d' % (port, newval)) connections_step = 25 if newval >= stat_dict.get(-1, 0) + connections_step: logging.info('port %d connections up to %d' % (port, newval)) stat_dict[-1] = stat_dict.get(-1, 0) + connections_step elif newval <= stat_dict.get(-1, 0) - connections_step: logging.info('port %d connections down to %d' % (port, newval)) stat_dict[-1] = stat_dict.get(-1, 0) - connections_step def stat_add(self, local_addr, val): if self._stat_counter is not None: if self._listen_port not in self._stat_counter: self._stat_counter[self._listen_port] = {} newval = self._stat_counter[self._listen_port].get(local_addr, 0) + val logging.debug('port %d addr %s connections %d' % (self._listen_port, local_addr, newval)) self._stat_counter[self._listen_port][local_addr] = newval self.update_stat(self._listen_port, self._stat_counter[self._listen_port], val) if newval <= 0: if local_addr in self._stat_counter[self._listen_port]: del self._stat_counter[self._listen_port][local_addr] newval = self._stat_counter.get(0, 0) + val self._stat_counter[0] = newval logging.debug('Total connections %d' % newval) connections_step = 50 if newval >= self._stat_counter.get(-1, 0) + connections_step: logging.info('Total connections up to %d' % newval) self._stat_counter[-1] = self._stat_counter.get(-1, 0) + connections_step elif newval <= self._stat_counter.get(-1, 0) - connections_step: logging.info('Total connections down to %d' % newval) self._stat_counter[-1] = self._stat_counter.get(-1, 0) - connections_step 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.debug('timed out: %s:%d' % handler.remote_address) else: logging.debug('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() handler = TCPRelayHandler(self, self._fd_to_handlers, self._eventloop, conn[0], self._config, self._dns_resolver, self._is_local) if handler.stage() == STAGE_DESTROYED: conn[0].close() 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) for handler in list(self._fd_to_handlers.values()): handler.destroy() 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()