255 lines
9.8 KiB
Python
255 lines
9.8 KiB
Python
|
import sys
|
||
|
|
import time
|
||
|
|
|
||
|
|
from . import exceptions
|
||
|
|
from . import packet
|
||
|
|
from . import payload
|
||
|
|
|
||
|
|
|
||
|
|
class Socket(object):
|
||
|
|
"""An Engine.IO socket."""
|
||
|
|
upgrade_protocols = ['websocket']
|
||
|
|
|
||
|
|
def __init__(self, server, sid):
|
||
|
|
self.server = server
|
||
|
|
self.sid = sid
|
||
|
|
self.queue = self.server.create_queue()
|
||
|
|
self.last_ping = None
|
||
|
|
self.connected = False
|
||
|
|
self.upgrading = False
|
||
|
|
self.upgraded = False
|
||
|
|
self.closing = False
|
||
|
|
self.closed = False
|
||
|
|
self.session = {}
|
||
|
|
|
||
|
|
def poll(self):
|
||
|
|
"""Wait for packets to send to the client."""
|
||
|
|
queue_empty = self.server.get_queue_empty_exception()
|
||
|
|
try:
|
||
|
|
packets = [self.queue.get(
|
||
|
|
timeout=self.server.ping_interval + self.server.ping_timeout)]
|
||
|
|
self.queue.task_done()
|
||
|
|
except queue_empty:
|
||
|
|
raise exceptions.QueueEmpty()
|
||
|
|
if packets == [None]:
|
||
|
|
return []
|
||
|
|
while True:
|
||
|
|
try:
|
||
|
|
pkt = self.queue.get(block=False)
|
||
|
|
self.queue.task_done()
|
||
|
|
if pkt is None:
|
||
|
|
self.queue.put(None)
|
||
|
|
break
|
||
|
|
packets.append(pkt)
|
||
|
|
except queue_empty:
|
||
|
|
break
|
||
|
|
return packets
|
||
|
|
|
||
|
|
def receive(self, pkt):
|
||
|
|
"""Receive packet from the client."""
|
||
|
|
packet_name = packet.packet_names[pkt.packet_type] \
|
||
|
|
if pkt.packet_type < len(packet.packet_names) else 'UNKNOWN'
|
||
|
|
self.server.logger.info('%s: Received packet %s data %s',
|
||
|
|
self.sid, packet_name,
|
||
|
|
pkt.data if not isinstance(pkt.data, bytes)
|
||
|
|
else '<binary>')
|
||
|
|
if pkt.packet_type == packet.PONG:
|
||
|
|
self.schedule_ping()
|
||
|
|
elif pkt.packet_type == packet.MESSAGE:
|
||
|
|
self.server._trigger_event('message', self.sid, pkt.data,
|
||
|
|
run_async=self.server.async_handlers)
|
||
|
|
elif pkt.packet_type == packet.UPGRADE:
|
||
|
|
self.send(packet.Packet(packet.NOOP))
|
||
|
|
elif pkt.packet_type == packet.CLOSE:
|
||
|
|
self.close(wait=False, abort=True)
|
||
|
|
else:
|
||
|
|
raise exceptions.UnknownPacketError()
|
||
|
|
|
||
|
|
def check_ping_timeout(self):
|
||
|
|
"""Make sure the client is still responding to pings."""
|
||
|
|
if self.closed:
|
||
|
|
raise exceptions.SocketIsClosedError()
|
||
|
|
if self.last_ping and \
|
||
|
|
time.time() - self.last_ping > self.server.ping_timeout:
|
||
|
|
self.server.logger.info('%s: Client is gone, closing socket',
|
||
|
|
self.sid)
|
||
|
|
# Passing abort=False here will cause close() to write a
|
||
|
|
# CLOSE packet. This has the effect of updating half-open sockets
|
||
|
|
# to their correct state of disconnected
|
||
|
|
self.close(wait=False, abort=False)
|
||
|
|
return False
|
||
|
|
return True
|
||
|
|
|
||
|
|
def send(self, pkt):
|
||
|
|
"""Send a packet to the client."""
|
||
|
|
if not self.check_ping_timeout():
|
||
|
|
return
|
||
|
|
else:
|
||
|
|
self.queue.put(pkt)
|
||
|
|
self.server.logger.info('%s: Sending packet %s data %s',
|
||
|
|
self.sid, packet.packet_names[pkt.packet_type],
|
||
|
|
pkt.data if not isinstance(pkt.data, bytes)
|
||
|
|
else '<binary>')
|
||
|
|
|
||
|
|
def handle_get_request(self, environ, start_response):
|
||
|
|
"""Handle a long-polling GET request from the client."""
|
||
|
|
connections = [
|
||
|
|
s.strip()
|
||
|
|
for s in environ.get('HTTP_CONNECTION', '').lower().split(',')]
|
||
|
|
transport = environ.get('HTTP_UPGRADE', '').lower()
|
||
|
|
if 'upgrade' in connections and transport in self.upgrade_protocols:
|
||
|
|
self.server.logger.info('%s: Received request to upgrade to %s',
|
||
|
|
self.sid, transport)
|
||
|
|
return getattr(self, '_upgrade_' + transport)(environ,
|
||
|
|
start_response)
|
||
|
|
if self.upgrading or self.upgraded:
|
||
|
|
# we are upgrading to WebSocket, do not return any more packets
|
||
|
|
# through the polling endpoint
|
||
|
|
return [packet.Packet(packet.NOOP)]
|
||
|
|
try:
|
||
|
|
packets = self.poll()
|
||
|
|
except exceptions.QueueEmpty:
|
||
|
|
exc = sys.exc_info()
|
||
|
|
self.close(wait=False)
|
||
|
|
raise exc[1].with_traceback(exc[2])
|
||
|
|
return packets
|
||
|
|
|
||
|
|
def handle_post_request(self, environ):
|
||
|
|
"""Handle a long-polling POST request from the client."""
|
||
|
|
length = int(environ.get('CONTENT_LENGTH', '0'))
|
||
|
|
if length > self.server.max_http_buffer_size:
|
||
|
|
raise exceptions.ContentTooLongError()
|
||
|
|
else:
|
||
|
|
body = environ['wsgi.input'].read(length).decode('utf-8')
|
||
|
|
p = payload.Payload(encoded_payload=body)
|
||
|
|
for pkt in p.packets:
|
||
|
|
self.receive(pkt)
|
||
|
|
|
||
|
|
def close(self, wait=True, abort=False):
|
||
|
|
"""Close the socket connection."""
|
||
|
|
if not self.closed and not self.closing:
|
||
|
|
self.closing = True
|
||
|
|
self.server._trigger_event('disconnect', self.sid, run_async=False)
|
||
|
|
if not abort:
|
||
|
|
self.send(packet.Packet(packet.CLOSE))
|
||
|
|
self.closed = True
|
||
|
|
self.queue.put(None)
|
||
|
|
if wait:
|
||
|
|
self.queue.join()
|
||
|
|
|
||
|
|
def schedule_ping(self):
|
||
|
|
def send_ping():
|
||
|
|
self.last_ping = None
|
||
|
|
self.server.sleep(self.server.ping_interval)
|
||
|
|
if not self.closing and not self.closed:
|
||
|
|
self.last_ping = time.time()
|
||
|
|
self.send(packet.Packet(packet.PING))
|
||
|
|
|
||
|
|
self.server.start_background_task(send_ping)
|
||
|
|
|
||
|
|
def _upgrade_websocket(self, environ, start_response):
|
||
|
|
"""Upgrade the connection from polling to websocket."""
|
||
|
|
if self.upgraded:
|
||
|
|
raise IOError('Socket has been upgraded already')
|
||
|
|
if self.server._async['websocket'] is None:
|
||
|
|
# the selected async mode does not support websocket
|
||
|
|
return self.server._bad_request()
|
||
|
|
ws = self.server._async['websocket'](self._websocket_handler)
|
||
|
|
return ws(environ, start_response)
|
||
|
|
|
||
|
|
def _websocket_handler(self, ws):
|
||
|
|
"""Engine.IO handler for websocket transport."""
|
||
|
|
# try to set a socket timeout matching the configured ping interval
|
||
|
|
# and timeout
|
||
|
|
for attr in ['_sock', 'socket']: # pragma: no cover
|
||
|
|
if hasattr(ws, attr) and hasattr(getattr(ws, attr), 'settimeout'):
|
||
|
|
getattr(ws, attr).settimeout(
|
||
|
|
self.server.ping_interval + self.server.ping_timeout)
|
||
|
|
|
||
|
|
if self.connected:
|
||
|
|
# the socket was already connected, so this is an upgrade
|
||
|
|
self.upgrading = True # hold packet sends during the upgrade
|
||
|
|
|
||
|
|
pkt = ws.wait()
|
||
|
|
decoded_pkt = packet.Packet(encoded_packet=pkt)
|
||
|
|
if decoded_pkt.packet_type != packet.PING or \
|
||
|
|
decoded_pkt.data != 'probe':
|
||
|
|
self.server.logger.info(
|
||
|
|
'%s: Failed websocket upgrade, no PING packet', self.sid)
|
||
|
|
self.upgrading = False
|
||
|
|
return []
|
||
|
|
ws.send(packet.Packet(packet.PONG, data='probe').encode())
|
||
|
|
self.queue.put(packet.Packet(packet.NOOP)) # end poll
|
||
|
|
|
||
|
|
pkt = ws.wait()
|
||
|
|
decoded_pkt = packet.Packet(encoded_packet=pkt)
|
||
|
|
if decoded_pkt.packet_type != packet.UPGRADE:
|
||
|
|
self.upgraded = False
|
||
|
|
self.server.logger.info(
|
||
|
|
('%s: Failed websocket upgrade, expected UPGRADE packet, '
|
||
|
|
'received %s instead.'),
|
||
|
|
self.sid, pkt)
|
||
|
|
self.upgrading = False
|
||
|
|
return []
|
||
|
|
self.upgraded = True
|
||
|
|
self.upgrading = False
|
||
|
|
else:
|
||
|
|
self.connected = True
|
||
|
|
self.upgraded = True
|
||
|
|
|
||
|
|
# start separate writer thread
|
||
|
|
def writer():
|
||
|
|
while True:
|
||
|
|
packets = None
|
||
|
|
try:
|
||
|
|
packets = self.poll()
|
||
|
|
except exceptions.QueueEmpty:
|
||
|
|
break
|
||
|
|
if not packets:
|
||
|
|
# empty packet list returned -> connection closed
|
||
|
|
break
|
||
|
|
try:
|
||
|
|
for pkt in packets:
|
||
|
|
ws.send(pkt.encode())
|
||
|
|
except:
|
||
|
|
break
|
||
|
|
writer_task = self.server.start_background_task(writer)
|
||
|
|
|
||
|
|
self.server.logger.info(
|
||
|
|
'%s: Upgrade to websocket successful', self.sid)
|
||
|
|
|
||
|
|
while True:
|
||
|
|
p = None
|
||
|
|
try:
|
||
|
|
p = ws.wait()
|
||
|
|
except Exception as e:
|
||
|
|
# if the socket is already closed, we can assume this is a
|
||
|
|
# downstream error of that
|
||
|
|
if not self.closed: # pragma: no cover
|
||
|
|
self.server.logger.info(
|
||
|
|
'%s: Unexpected error "%s", closing connection',
|
||
|
|
self.sid, str(e))
|
||
|
|
break
|
||
|
|
if p is None:
|
||
|
|
# connection closed by client
|
||
|
|
break
|
||
|
|
pkt = packet.Packet(encoded_packet=p)
|
||
|
|
try:
|
||
|
|
self.receive(pkt)
|
||
|
|
except exceptions.UnknownPacketError: # pragma: no cover
|
||
|
|
pass
|
||
|
|
except exceptions.SocketIsClosedError: # pragma: no cover
|
||
|
|
self.server.logger.info('Receive error -- socket is closed')
|
||
|
|
break
|
||
|
|
except: # pragma: no cover
|
||
|
|
# if we get an unexpected exception we log the error and exit
|
||
|
|
# the connection properly
|
||
|
|
self.server.logger.exception('Unknown receive error')
|
||
|
|
break
|
||
|
|
|
||
|
|
self.queue.put(None) # unlock the writer task so that it can exit
|
||
|
|
writer_task.join()
|
||
|
|
self.close(wait=False, abort=True)
|
||
|
|
|
||
|
|
return []
|