def _on_remote_read(self):
# handle all remote read events
data = None
if self._is_local:
buf_size = UP_STREAM_BUF_SIZE
else:
buf_size = DOWN_STREAM_BUF_SIZE
try:
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):
return
if not data:
self.destroy()
return
self._update_activity(len(data))
if self._is_local:
data = self._cryptor.decrypt(data)
else:
data = self._cryptor.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 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_stage_connecting(self, data):
if not self._is_local:
if self._ota_enable_session:
self._ota_chunk_data(data,
self._data_to_write_to_remote.append)
else:
self._data_to_write_to_remote.append(data)
return
if self._ota_enable_session:
data = self._ota_chunk_data_gen(data)
data = self._cryptor.encrypt(data)
self._data_to_write_to_remote.append(data)
if self._config['fast_open'] and not self._fastopen_connected:
# 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 _send_control_data(self, data):
if not self._control_client_addr:
return
try:
self._control_socket.sendto(data, self._control_client_addr)
except (socket.error, 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()
def _handle_dns_resolved(self, result, error):
if error:
addr, port = self._client_address[0], self._client_address[1]
logging.error('%s when handling connection from %s:%d' %
(error, addr, port))
self.destroy()
return
if not (result and result[1]):
self.destroy()
return
ip = result[1]
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 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)
try:
remote_sock.connect((remote_addr, remote_port))
except (OSError, IOError) as e:
if eventloop.errno_from_exception(e) == \
errno.EINPROGRESS:
pass
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)
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
if is_local:
buf_size = UP_STREAM_BUF_SIZE
else:
buf_size = DOWN_STREAM_BUF_SIZE
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
self._update_activity(len(data))
if not is_local:
data = self._cryptor.decrypt(data)
if not data:
return
if self._stage == STAGE_STREAM:
self._handle_stage_stream(data)
return
elif is_local and self._stage == STAGE_INIT:
# jump over socks5 init
if self._is_tunnel:
self._handle_stage_addr(data)
return
else:
self._handle_stage_init(data)
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(data)
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 data or not sock:
return False
uncomplete = False
try:
l = len(data)
s = sock.send(data)
if s < l:
data = data[s:]
uncomplete = True
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:
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 _handle_server(self):
server = self._server_socket
data, r_addr = server.recvfrom(BUF_SIZE)
key = None
iv = None
if not data:
logging.debug('UDP handle_server: data is empty')
if self._stat_callback:
self._stat_callback(self._listen_port, len(data))
if self._is_local:
if self._is_tunnel:
# add ss header to data
tunnel_remote = self.tunnel_remote
tunnel_remote_port = self.tunnel_remote_port
data = common.add_header(tunnel_remote, tunnel_remote_port,
data)
else:
frag = common.ord(data[2])
if frag != 0:
logging.warn('UDP drop a message since frag is not 0')
return
else:
data = data[3:]
else:
# decrypt data
try:
data, key, iv = cryptor.decrypt_all(self._password,
self._method, data,
self._crypto_path)
except Exception:
logging.debug('UDP handle_server: decrypt data failed')
return
if not data:
logging.debug('UDP handle_server: data is empty after decrypt')
return
header_result = parse_header(data)
if header_result is None:
return
addrtype, dest_addr, dest_port, header_length = header_result
logging.info("udp data to %s:%d from %s:%d" %
(dest_addr, dest_port, r_addr[0], r_addr[1]))
if self._is_local:
server_addr, server_port = self._get_a_server()
else:
server_addr, server_port = dest_addr, dest_port
# spec https://hshadow.org/en/spec/one-time-auth.html
self._ota_enable_session = addrtype & ADDRTYPE_AUTH
if self._ota_enable and not self._ota_enable_session:
logging.warn('client one time auth is required')
return
if self._ota_enable_session:
if len(data) < header_length + ONETIMEAUTH_BYTES:
logging.warn('UDP one time auth header is too short')
return
_hash = data[-ONETIMEAUTH_BYTES:]
data = data[:-ONETIMEAUTH_BYTES]
_key = iv + key
if onetimeauth_verify(_hash, data, _key) is False:
logging.warn('UDP one time auth fail')
return
addrs = self._dns_cache.get(server_addr, None)
if addrs is None:
addrs = socket.getaddrinfo(server_addr, server_port, 0,
socket.SOCK_DGRAM, socket.SOL_UDP)
if not addrs:
# drop
return
else:
self._dns_cache[server_addr] = addrs
af, socktype, proto, canonname, sa = addrs[0]
key = client_key(r_addr, af)
client = self._cache.get(key, None)
if not client:
# TODO async getaddrinfo
if self._forbidden_iplist:
if common.to_str(sa[0]) in self._forbidden_iplist:
logging.debug('IP %s is in forbidden list, drop' %
common.to_str(sa[0]))
# drop
return
client = socket.socket(af, socktype, proto)
client.setblocking(False)
self._cache[key] = client
self._client_fd_to_server_addr[client.fileno()] = r_addr
self._sockets.add(client.fileno())
self._eventloop.add(client, eventloop.POLL_IN, self)
if self._is_local:
key, iv, m = cryptor.gen_key_iv(self._password, self._method)
# spec https://hshadow.org/en/spec/one-time-auth.html
if self._ota_enable_session:
data = self._ota_chunk_data_gen(key, iv, data)
try:
data = cryptor.encrypt_all_m(key, iv, m, self._method, data,
self._crypto_path)
except Exception:
logging.debug("UDP handle_server: encrypt data failed")
return
if not data:
return
else:
data = data[header_length:]
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:
shell.print_exception(e)
