771 lines
33 KiB
Python
771 lines
33 KiB
Python
|
import base64
|
||
|
|
import gzip
|
||
|
|
import importlib
|
||
|
|
import io
|
||
|
|
import logging
|
||
|
|
import secrets
|
||
|
|
import urllib
|
||
|
|
import zlib
|
||
|
|
|
||
|
|
from . import exceptions
|
||
|
|
from . import packet
|
||
|
|
from . import payload
|
||
|
|
from . import socket
|
||
|
|
|
||
|
|
default_logger = logging.getLogger('engineio.server')
|
||
|
|
|
||
|
|
|
||
|
|
class Server(object):
|
||
|
|
"""An Engine.IO server.
|
||
|
|
|
||
|
|
This class implements a fully compliant Engine.IO web server with support
|
||
|
|
for websocket and long-polling transports.
|
||
|
|
|
||
|
|
:param async_mode: The asynchronous model to use. See the Deployment
|
||
|
|
section in the documentation for a description of the
|
||
|
|
available options. Valid async modes are "threading",
|
||
|
|
"eventlet", "gevent" and "gevent_uwsgi". If this
|
||
|
|
argument is not given, "eventlet" is tried first, then
|
||
|
|
"gevent_uwsgi", then "gevent", and finally "threading".
|
||
|
|
The first async mode that has all its dependencies
|
||
|
|
installed is the one that is chosen.
|
||
|
|
:param ping_interval: The interval in seconds at which the server pings
|
||
|
|
the client. The default is 25 seconds. For advanced
|
||
|
|
control, a two element tuple can be given, where
|
||
|
|
the first number is the ping interval and the second
|
||
|
|
is a grace period added by the server.
|
||
|
|
:param ping_timeout: The time in seconds that the client waits for the
|
||
|
|
server to respond before disconnecting. The default
|
||
|
|
is 20 seconds.
|
||
|
|
:param max_http_buffer_size: The maximum size of a message. The default
|
||
|
|
is 1,000,000 bytes.
|
||
|
|
:param allow_upgrades: Whether to allow transport upgrades or not. The
|
||
|
|
default is ``True``.
|
||
|
|
:param http_compression: Whether to compress packages when using the
|
||
|
|
polling transport. The default is ``True``.
|
||
|
|
:param compression_threshold: Only compress messages when their byte size
|
||
|
|
is greater than this value. The default is
|
||
|
|
1024 bytes.
|
||
|
|
:param cookie: If set to a string, it is the name of the HTTP cookie the
|
||
|
|
server sends back tot he client containing the client
|
||
|
|
session id. If set to a dictionary, the ``'name'`` key
|
||
|
|
contains the cookie name and other keys define cookie
|
||
|
|
attributes, where the value of each attribute can be a
|
||
|
|
string, a callable with no arguments, or a boolean. If set
|
||
|
|
to ``None`` (the default), a cookie is not sent to the
|
||
|
|
client.
|
||
|
|
:param cors_allowed_origins: Origin or list of origins that are allowed to
|
||
|
|
connect to this server. Only the same origin
|
||
|
|
is allowed by default. Set this argument to
|
||
|
|
``'*'`` to allow all origins, or to ``[]`` to
|
||
|
|
disable CORS handling.
|
||
|
|
:param cors_credentials: Whether credentials (cookies, authentication) are
|
||
|
|
allowed in requests to this server. The default
|
||
|
|
is ``True``.
|
||
|
|
:param logger: To enable logging set to ``True`` or pass a logger object to
|
||
|
|
use. To disable logging set to ``False``. The default is
|
||
|
|
``False``. Note that fatal errors are logged even when
|
||
|
|
``logger`` is ``False``.
|
||
|
|
:param json: An alternative json module to use for encoding and decoding
|
||
|
|
packets. Custom json modules must have ``dumps`` and ``loads``
|
||
|
|
functions that are compatible with the standard library
|
||
|
|
versions.
|
||
|
|
:param async_handlers: If set to ``True``, run message event handlers in
|
||
|
|
non-blocking threads. To run handlers synchronously,
|
||
|
|
set to ``False``. The default is ``True``.
|
||
|
|
:param monitor_clients: If set to ``True``, a background task will ensure
|
||
|
|
inactive clients are closed. Set to ``False`` to
|
||
|
|
disable the monitoring task (not recommended). The
|
||
|
|
default is ``True``.
|
||
|
|
:param transports: The list of allowed transports. Valid transports
|
||
|
|
are ``'polling'`` and ``'websocket'``. Defaults to
|
||
|
|
``['polling', 'websocket']``.
|
||
|
|
:param kwargs: Reserved for future extensions, any additional parameters
|
||
|
|
given as keyword arguments will be silently ignored.
|
||
|
|
"""
|
||
|
|
compression_methods = ['gzip', 'deflate']
|
||
|
|
event_names = ['connect', 'disconnect', 'message']
|
||
|
|
valid_transports = ['polling', 'websocket']
|
||
|
|
_default_monitor_clients = True
|
||
|
|
sequence_number = 0
|
||
|
|
|
||
|
|
def __init__(self, async_mode=None, ping_interval=25, ping_timeout=20,
|
||
|
|
max_http_buffer_size=1000000, allow_upgrades=True,
|
||
|
|
http_compression=True, compression_threshold=1024,
|
||
|
|
cookie=None, cors_allowed_origins=None,
|
||
|
|
cors_credentials=True, logger=False, json=None,
|
||
|
|
async_handlers=True, monitor_clients=None, transports=None,
|
||
|
|
**kwargs):
|
||
|
|
self.ping_timeout = ping_timeout
|
||
|
|
if isinstance(ping_interval, tuple):
|
||
|
|
self.ping_interval = ping_interval[0]
|
||
|
|
self.ping_interval_grace_period = ping_interval[1]
|
||
|
|
else:
|
||
|
|
self.ping_interval = ping_interval
|
||
|
|
self.ping_interval_grace_period = 0
|
||
|
|
self.max_http_buffer_size = max_http_buffer_size
|
||
|
|
self.allow_upgrades = allow_upgrades
|
||
|
|
self.http_compression = http_compression
|
||
|
|
self.compression_threshold = compression_threshold
|
||
|
|
self.cookie = cookie
|
||
|
|
self.cors_allowed_origins = cors_allowed_origins
|
||
|
|
self.cors_credentials = cors_credentials
|
||
|
|
self.async_handlers = async_handlers
|
||
|
|
self.sockets = {}
|
||
|
|
self.handlers = {}
|
||
|
|
self.log_message_keys = set()
|
||
|
|
self.start_service_task = monitor_clients \
|
||
|
|
if monitor_clients is not None else self._default_monitor_clients
|
||
|
|
if json is not None:
|
||
|
|
packet.Packet.json = json
|
||
|
|
if not isinstance(logger, bool):
|
||
|
|
self.logger = logger
|
||
|
|
else:
|
||
|
|
self.logger = default_logger
|
||
|
|
if self.logger.level == logging.NOTSET:
|
||
|
|
if logger:
|
||
|
|
self.logger.setLevel(logging.INFO)
|
||
|
|
else:
|
||
|
|
self.logger.setLevel(logging.ERROR)
|
||
|
|
self.logger.addHandler(logging.StreamHandler())
|
||
|
|
modes = self.async_modes()
|
||
|
|
if async_mode is not None:
|
||
|
|
modes = [async_mode] if async_mode in modes else []
|
||
|
|
self._async = None
|
||
|
|
self.async_mode = None
|
||
|
|
for mode in modes:
|
||
|
|
try:
|
||
|
|
self._async = importlib.import_module(
|
||
|
|
'engineio.async_drivers.' + mode)._async
|
||
|
|
asyncio_based = self._async['asyncio'] \
|
||
|
|
if 'asyncio' in self._async else False
|
||
|
|
if asyncio_based != self.is_asyncio_based():
|
||
|
|
continue # pragma: no cover
|
||
|
|
self.async_mode = mode
|
||
|
|
break
|
||
|
|
except ImportError:
|
||
|
|
pass
|
||
|
|
if self.async_mode is None:
|
||
|
|
raise ValueError('Invalid async_mode specified')
|
||
|
|
if self.is_asyncio_based() and \
|
||
|
|
('asyncio' not in self._async or not
|
||
|
|
self._async['asyncio']): # pragma: no cover
|
||
|
|
raise ValueError('The selected async_mode is not asyncio '
|
||
|
|
'compatible')
|
||
|
|
if not self.is_asyncio_based() and 'asyncio' in self._async and \
|
||
|
|
self._async['asyncio']: # pragma: no cover
|
||
|
|
raise ValueError('The selected async_mode requires asyncio and '
|
||
|
|
'must use the AsyncServer class')
|
||
|
|
if transports is not None:
|
||
|
|
if isinstance(transports, str):
|
||
|
|
transports = [transports]
|
||
|
|
transports = [transport for transport in transports
|
||
|
|
if transport in self.valid_transports]
|
||
|
|
if not transports:
|
||
|
|
raise ValueError('No valid transports provided')
|
||
|
|
self.transports = transports or self.valid_transports
|
||
|
|
self.logger.info('Server initialized for %s.', self.async_mode)
|
||
|
|
|
||
|
|
def is_asyncio_based(self):
|
||
|
|
return False
|
||
|
|
|
||
|
|
def async_modes(self):
|
||
|
|
return ['eventlet', 'gevent_uwsgi', 'gevent', 'threading']
|
||
|
|
|
||
|
|
def on(self, event, handler=None):
|
||
|
|
"""Register an event handler.
|
||
|
|
|
||
|
|
:param event: The event name. Can be ``'connect'``, ``'message'`` or
|
||
|
|
``'disconnect'``.
|
||
|
|
:param handler: The function that should be invoked to handle the
|
||
|
|
event. When this parameter is not given, the method
|
||
|
|
acts as a decorator for the handler function.
|
||
|
|
|
||
|
|
Example usage::
|
||
|
|
|
||
|
|
# as a decorator:
|
||
|
|
@eio.on('connect')
|
||
|
|
def connect_handler(sid, environ):
|
||
|
|
print('Connection request')
|
||
|
|
if environ['REMOTE_ADDR'] in blacklisted:
|
||
|
|
return False # reject
|
||
|
|
|
||
|
|
# as a method:
|
||
|
|
def message_handler(sid, msg):
|
||
|
|
print('Received message: ', msg)
|
||
|
|
eio.send(sid, 'response')
|
||
|
|
eio.on('message', message_handler)
|
||
|
|
|
||
|
|
The handler function receives the ``sid`` (session ID) for the
|
||
|
|
client as first argument. The ``'connect'`` event handler receives the
|
||
|
|
WSGI environment as a second argument, and can return ``False`` to
|
||
|
|
reject the connection. The ``'message'`` handler receives the message
|
||
|
|
payload as a second argument. The ``'disconnect'`` handler does not
|
||
|
|
take a second argument.
|
||
|
|
"""
|
||
|
|
if event not in self.event_names:
|
||
|
|
raise ValueError('Invalid event')
|
||
|
|
|
||
|
|
def set_handler(handler):
|
||
|
|
self.handlers[event] = handler
|
||
|
|
return handler
|
||
|
|
|
||
|
|
if handler is None:
|
||
|
|
return set_handler
|
||
|
|
set_handler(handler)
|
||
|
|
|
||
|
|
def send(self, sid, data):
|
||
|
|
"""Send a message to a client.
|
||
|
|
|
||
|
|
:param sid: The session id of the recipient client.
|
||
|
|
:param data: The data to send to the client. Data can be of type
|
||
|
|
``str``, ``bytes``, ``list`` or ``dict``. If a ``list``
|
||
|
|
or ``dict``, the data will be serialized as JSON.
|
||
|
|
"""
|
||
|
|
try:
|
||
|
|
socket = self._get_socket(sid)
|
||
|
|
except KeyError:
|
||
|
|
# the socket is not available
|
||
|
|
self.logger.warning('Cannot send to sid %s', sid)
|
||
|
|
return
|
||
|
|
socket.send(packet.Packet(packet.MESSAGE, data=data))
|
||
|
|
|
||
|
|
def get_session(self, sid):
|
||
|
|
"""Return the user session for a client.
|
||
|
|
|
||
|
|
:param sid: The session id of the client.
|
||
|
|
|
||
|
|
The return value is a dictionary. Modifications made to this
|
||
|
|
dictionary are not guaranteed to be preserved unless
|
||
|
|
``save_session()`` is called, or when the ``session`` context manager
|
||
|
|
is used.
|
||
|
|
"""
|
||
|
|
socket = self._get_socket(sid)
|
||
|
|
return socket.session
|
||
|
|
|
||
|
|
def save_session(self, sid, session):
|
||
|
|
"""Store the user session for a client.
|
||
|
|
|
||
|
|
:param sid: The session id of the client.
|
||
|
|
:param session: The session dictionary.
|
||
|
|
"""
|
||
|
|
socket = self._get_socket(sid)
|
||
|
|
socket.session = session
|
||
|
|
|
||
|
|
def session(self, sid):
|
||
|
|
"""Return the user session for a client with context manager syntax.
|
||
|
|
|
||
|
|
:param sid: The session id of the client.
|
||
|
|
|
||
|
|
This is a context manager that returns the user session dictionary for
|
||
|
|
the client. Any changes that are made to this dictionary inside the
|
||
|
|
context manager block are saved back to the session. Example usage::
|
||
|
|
|
||
|
|
@eio.on('connect')
|
||
|
|
def on_connect(sid, environ):
|
||
|
|
username = authenticate_user(environ)
|
||
|
|
if not username:
|
||
|
|
return False
|
||
|
|
with eio.session(sid) as session:
|
||
|
|
session['username'] = username
|
||
|
|
|
||
|
|
@eio.on('message')
|
||
|
|
def on_message(sid, msg):
|
||
|
|
with eio.session(sid) as session:
|
||
|
|
print('received message from ', session['username'])
|
||
|
|
"""
|
||
|
|
class _session_context_manager(object):
|
||
|
|
def __init__(self, server, sid):
|
||
|
|
self.server = server
|
||
|
|
self.sid = sid
|
||
|
|
self.session = None
|
||
|
|
|
||
|
|
def __enter__(self):
|
||
|
|
self.session = self.server.get_session(sid)
|
||
|
|
return self.session
|
||
|
|
|
||
|
|
def __exit__(self, *args):
|
||
|
|
self.server.save_session(sid, self.session)
|
||
|
|
|
||
|
|
return _session_context_manager(self, sid)
|
||
|
|
|
||
|
|
def disconnect(self, sid=None):
|
||
|
|
"""Disconnect a client.
|
||
|
|
|
||
|
|
:param sid: The session id of the client to close. If this parameter
|
||
|
|
is not given, then all clients are closed.
|
||
|
|
"""
|
||
|
|
if sid is not None:
|
||
|
|
try:
|
||
|
|
socket = self._get_socket(sid)
|
||
|
|
except KeyError: # pragma: no cover
|
||
|
|
# the socket was already closed or gone
|
||
|
|
pass
|
||
|
|
else:
|
||
|
|
socket.close()
|
||
|
|
if sid in self.sockets: # pragma: no cover
|
||
|
|
del self.sockets[sid]
|
||
|
|
else:
|
||
|
|
for client in self.sockets.values():
|
||
|
|
client.close()
|
||
|
|
self.sockets = {}
|
||
|
|
|
||
|
|
def transport(self, sid):
|
||
|
|
"""Return the name of the transport used by the client.
|
||
|
|
|
||
|
|
The two possible values returned by this function are ``'polling'``
|
||
|
|
and ``'websocket'``.
|
||
|
|
|
||
|
|
:param sid: The session of the client.
|
||
|
|
"""
|
||
|
|
return 'websocket' if self._get_socket(sid).upgraded else 'polling'
|
||
|
|
|
||
|
|
def handle_request(self, environ, start_response):
|
||
|
|
"""Handle an HTTP request from the client.
|
||
|
|
|
||
|
|
This is the entry point of the Engine.IO application, using the same
|
||
|
|
interface as a WSGI application. For the typical usage, this function
|
||
|
|
is invoked by the :class:`Middleware` instance, but it can be invoked
|
||
|
|
directly when the middleware is not used.
|
||
|
|
|
||
|
|
:param environ: The WSGI environment.
|
||
|
|
:param start_response: The WSGI ``start_response`` function.
|
||
|
|
|
||
|
|
This function returns the HTTP response body to deliver to the client
|
||
|
|
as a byte sequence.
|
||
|
|
"""
|
||
|
|
if self.cors_allowed_origins != []:
|
||
|
|
# Validate the origin header if present
|
||
|
|
# This is important for WebSocket more than for HTTP, since
|
||
|
|
# browsers only apply CORS controls to HTTP.
|
||
|
|
origin = environ.get('HTTP_ORIGIN')
|
||
|
|
if origin:
|
||
|
|
allowed_origins = self._cors_allowed_origins(environ)
|
||
|
|
if allowed_origins is not None and origin not in \
|
||
|
|
allowed_origins:
|
||
|
|
self._log_error_once(
|
||
|
|
origin + ' is not an accepted origin.', 'bad-origin')
|
||
|
|
r = self._bad_request('Not an accepted origin.')
|
||
|
|
start_response(r['status'], r['headers'])
|
||
|
|
return [r['response']]
|
||
|
|
|
||
|
|
method = environ['REQUEST_METHOD']
|
||
|
|
query = urllib.parse.parse_qs(environ.get('QUERY_STRING', ''))
|
||
|
|
jsonp = False
|
||
|
|
jsonp_index = None
|
||
|
|
|
||
|
|
# make sure the client uses an allowed transport
|
||
|
|
transport = query.get('transport', ['polling'])[0]
|
||
|
|
if transport not in self.transports:
|
||
|
|
self._log_error_once('Invalid transport', 'bad-transport')
|
||
|
|
r = self._bad_request('Invalid transport')
|
||
|
|
start_response(r['status'], r['headers'])
|
||
|
|
return [r['response']]
|
||
|
|
|
||
|
|
# make sure the client speaks a compatible Engine.IO version
|
||
|
|
sid = query['sid'][0] if 'sid' in query else None
|
||
|
|
if sid is None and query.get('EIO') != ['4']:
|
||
|
|
self._log_error_once(
|
||
|
|
'The client is using an unsupported version of the Socket.IO '
|
||
|
|
'or Engine.IO protocols', 'bad-version')
|
||
|
|
r = self._bad_request(
|
||
|
|
'The client is using an unsupported version of the Socket.IO '
|
||
|
|
'or Engine.IO protocols')
|
||
|
|
start_response(r['status'], r['headers'])
|
||
|
|
return [r['response']]
|
||
|
|
|
||
|
|
if 'j' in query:
|
||
|
|
jsonp = True
|
||
|
|
try:
|
||
|
|
jsonp_index = int(query['j'][0])
|
||
|
|
except (ValueError, KeyError, IndexError):
|
||
|
|
# Invalid JSONP index number
|
||
|
|
pass
|
||
|
|
|
||
|
|
if jsonp and jsonp_index is None:
|
||
|
|
self._log_error_once('Invalid JSONP index number',
|
||
|
|
'bad-jsonp-index')
|
||
|
|
r = self._bad_request('Invalid JSONP index number')
|
||
|
|
elif method == 'GET':
|
||
|
|
if sid is None:
|
||
|
|
# transport must be one of 'polling' or 'websocket'.
|
||
|
|
# if 'websocket', the HTTP_UPGRADE header must match.
|
||
|
|
upgrade_header = environ.get('HTTP_UPGRADE').lower() \
|
||
|
|
if 'HTTP_UPGRADE' in environ else None
|
||
|
|
if transport == 'polling' \
|
||
|
|
or transport == upgrade_header == 'websocket':
|
||
|
|
r = self._handle_connect(environ, start_response,
|
||
|
|
transport, jsonp_index)
|
||
|
|
else:
|
||
|
|
self._log_error_once('Invalid websocket upgrade',
|
||
|
|
'bad-upgrade')
|
||
|
|
r = self._bad_request('Invalid websocket upgrade')
|
||
|
|
else:
|
||
|
|
if sid not in self.sockets:
|
||
|
|
self._log_error_once('Invalid session ' + sid, 'bad-sid')
|
||
|
|
r = self._bad_request('Invalid session')
|
||
|
|
else:
|
||
|
|
socket = self._get_socket(sid)
|
||
|
|
try:
|
||
|
|
packets = socket.handle_get_request(
|
||
|
|
environ, start_response)
|
||
|
|
if isinstance(packets, list):
|
||
|
|
r = self._ok(packets, jsonp_index=jsonp_index)
|
||
|
|
else:
|
||
|
|
r = packets
|
||
|
|
except exceptions.EngineIOError:
|
||
|
|
if sid in self.sockets: # pragma: no cover
|
||
|
|
self.disconnect(sid)
|
||
|
|
r = self._bad_request()
|
||
|
|
if sid in self.sockets and self.sockets[sid].closed:
|
||
|
|
del self.sockets[sid]
|
||
|
|
elif method == 'POST':
|
||
|
|
if sid is None or sid not in self.sockets:
|
||
|
|
self._log_error_once(
|
||
|
|
'Invalid session ' + (sid or 'None'), 'bad-sid')
|
||
|
|
r = self._bad_request('Invalid session')
|
||
|
|
else:
|
||
|
|
socket = self._get_socket(sid)
|
||
|
|
try:
|
||
|
|
socket.handle_post_request(environ)
|
||
|
|
r = self._ok(jsonp_index=jsonp_index)
|
||
|
|
except exceptions.EngineIOError:
|
||
|
|
if sid in self.sockets: # pragma: no cover
|
||
|
|
self.disconnect(sid)
|
||
|
|
r = self._bad_request()
|
||
|
|
except: # pragma: no cover
|
||
|
|
# for any other unexpected errors, we log the error
|
||
|
|
# and keep going
|
||
|
|
self.logger.exception('post request handler error')
|
||
|
|
r = self._ok(jsonp_index=jsonp_index)
|
||
|
|
elif method == 'OPTIONS':
|
||
|
|
r = self._ok()
|
||
|
|
else:
|
||
|
|
self.logger.warning('Method %s not supported', method)
|
||
|
|
r = self._method_not_found()
|
||
|
|
|
||
|
|
if not isinstance(r, dict):
|
||
|
|
return r or []
|
||
|
|
if self.http_compression and \
|
||
|
|
len(r['response']) >= self.compression_threshold:
|
||
|
|
encodings = [e.split(';')[0].strip() for e in
|
||
|
|
environ.get('HTTP_ACCEPT_ENCODING', '').split(',')]
|
||
|
|
for encoding in encodings:
|
||
|
|
if encoding in self.compression_methods:
|
||
|
|
r['response'] = \
|
||
|
|
getattr(self, '_' + encoding)(r['response'])
|
||
|
|
r['headers'] += [('Content-Encoding', encoding)]
|
||
|
|
break
|
||
|
|
cors_headers = self._cors_headers(environ)
|
||
|
|
start_response(r['status'], r['headers'] + cors_headers)
|
||
|
|
return [r['response']]
|
||
|
|
|
||
|
|
def start_background_task(self, target, *args, **kwargs):
|
||
|
|
"""Start a background task using the appropriate async model.
|
||
|
|
|
||
|
|
This is a utility function that applications can use to start a
|
||
|
|
background task using the method that is compatible with the
|
||
|
|
selected async mode.
|
||
|
|
|
||
|
|
:param target: the target function to execute.
|
||
|
|
:param args: arguments to pass to the function.
|
||
|
|
:param kwargs: keyword arguments to pass to the function.
|
||
|
|
|
||
|
|
This function returns an object that represents the background task,
|
||
|
|
on which the ``join()`` methond can be invoked to wait for the task to
|
||
|
|
complete.
|
||
|
|
"""
|
||
|
|
th = self._async['thread'](target=target, args=args, kwargs=kwargs)
|
||
|
|
th.start()
|
||
|
|
return th # pragma: no cover
|
||
|
|
|
||
|
|
def sleep(self, seconds=0):
|
||
|
|
"""Sleep for the requested amount of time using the appropriate async
|
||
|
|
model.
|
||
|
|
|
||
|
|
This is a utility function that applications can use to put a task to
|
||
|
|
sleep without having to worry about using the correct call for the
|
||
|
|
selected async mode.
|
||
|
|
"""
|
||
|
|
return self._async['sleep'](seconds)
|
||
|
|
|
||
|
|
def create_queue(self, *args, **kwargs):
|
||
|
|
"""Create a queue object using the appropriate async model.
|
||
|
|
|
||
|
|
This is a utility function that applications can use to create a queue
|
||
|
|
without having to worry about using the correct call for the selected
|
||
|
|
async mode.
|
||
|
|
"""
|
||
|
|
return self._async['queue'](*args, **kwargs)
|
||
|
|
|
||
|
|
def get_queue_empty_exception(self):
|
||
|
|
"""Return the queue empty exception for the appropriate async model.
|
||
|
|
|
||
|
|
This is a utility function that applications can use to work with a
|
||
|
|
queue without having to worry about using the correct call for the
|
||
|
|
selected async mode.
|
||
|
|
"""
|
||
|
|
return self._async['queue_empty']
|
||
|
|
|
||
|
|
def create_event(self, *args, **kwargs):
|
||
|
|
"""Create an event object using the appropriate async model.
|
||
|
|
|
||
|
|
This is a utility function that applications can use to create an
|
||
|
|
event without having to worry about using the correct call for the
|
||
|
|
selected async mode.
|
||
|
|
"""
|
||
|
|
return self._async['event'](*args, **kwargs)
|
||
|
|
|
||
|
|
def generate_id(self):
|
||
|
|
"""Generate a unique session id."""
|
||
|
|
id = base64.b64encode(
|
||
|
|
secrets.token_bytes(12) + self.sequence_number.to_bytes(3, 'big'))
|
||
|
|
self.sequence_number = (self.sequence_number + 1) & 0xffffff
|
||
|
|
return id.decode('utf-8').replace('/', '_').replace('+', '-')
|
||
|
|
|
||
|
|
def _generate_sid_cookie(self, sid, attributes):
|
||
|
|
"""Generate the sid cookie."""
|
||
|
|
cookie = attributes.get('name', 'io') + '=' + sid
|
||
|
|
for attribute, value in attributes.items():
|
||
|
|
if attribute == 'name':
|
||
|
|
continue
|
||
|
|
if callable(value):
|
||
|
|
value = value()
|
||
|
|
if value is True:
|
||
|
|
cookie += '; ' + attribute
|
||
|
|
else:
|
||
|
|
cookie += '; ' + attribute + '=' + value
|
||
|
|
return cookie
|
||
|
|
|
||
|
|
def _handle_connect(self, environ, start_response, transport,
|
||
|
|
jsonp_index=None):
|
||
|
|
"""Handle a client connection request."""
|
||
|
|
if self.start_service_task:
|
||
|
|
# start the service task to monitor connected clients
|
||
|
|
self.start_service_task = False
|
||
|
|
self.start_background_task(self._service_task)
|
||
|
|
|
||
|
|
sid = self.generate_id()
|
||
|
|
s = socket.Socket(self, sid)
|
||
|
|
self.sockets[sid] = s
|
||
|
|
|
||
|
|
pkt = packet.Packet(packet.OPEN, {
|
||
|
|
'sid': sid,
|
||
|
|
'upgrades': self._upgrades(sid, transport),
|
||
|
|
'pingTimeout': int(self.ping_timeout * 1000),
|
||
|
|
'pingInterval': int(
|
||
|
|
self.ping_interval + self.ping_interval_grace_period) * 1000})
|
||
|
|
s.send(pkt)
|
||
|
|
s.schedule_ping()
|
||
|
|
|
||
|
|
# NOTE: some sections below are marked as "no cover" to workaround
|
||
|
|
# what seems to be a bug in the coverage package. All the lines below
|
||
|
|
# are covered by tests, but some are not reported as such for some
|
||
|
|
# reason
|
||
|
|
ret = self._trigger_event('connect', sid, environ, run_async=False)
|
||
|
|
if ret is not None and ret is not True: # pragma: no cover
|
||
|
|
del self.sockets[sid]
|
||
|
|
self.logger.warning('Application rejected connection')
|
||
|
|
return self._unauthorized(ret or None)
|
||
|
|
|
||
|
|
if transport == 'websocket': # pragma: no cover
|
||
|
|
ret = s.handle_get_request(environ, start_response)
|
||
|
|
if s.closed and sid in self.sockets:
|
||
|
|
# websocket connection ended, so we are done
|
||
|
|
del self.sockets[sid]
|
||
|
|
return ret
|
||
|
|
else: # pragma: no cover
|
||
|
|
s.connected = True
|
||
|
|
headers = None
|
||
|
|
if self.cookie:
|
||
|
|
if isinstance(self.cookie, dict):
|
||
|
|
headers = [(
|
||
|
|
'Set-Cookie',
|
||
|
|
self._generate_sid_cookie(sid, self.cookie)
|
||
|
|
)]
|
||
|
|
else:
|
||
|
|
headers = [(
|
||
|
|
'Set-Cookie',
|
||
|
|
self._generate_sid_cookie(sid, {
|
||
|
|
'name': self.cookie, 'path': '/', 'SameSite': 'Lax'
|
||
|
|
})
|
||
|
|
)]
|
||
|
|
try:
|
||
|
|
return self._ok(s.poll(), headers=headers,
|
||
|
|
jsonp_index=jsonp_index)
|
||
|
|
except exceptions.QueueEmpty:
|
||
|
|
return self._bad_request()
|
||
|
|
|
||
|
|
def _upgrades(self, sid, transport):
|
||
|
|
"""Return the list of possible upgrades for a client connection."""
|
||
|
|
if not self.allow_upgrades or self._get_socket(sid).upgraded or \
|
||
|
|
transport == 'websocket':
|
||
|
|
return []
|
||
|
|
if self._async['websocket'] is None: # pragma: no cover
|
||
|
|
self._log_error_once(
|
||
|
|
'The WebSocket transport is not available, you must install a '
|
||
|
|
'WebSocket server that is compatible with your async mode to '
|
||
|
|
'enable it. See the documentation for details.',
|
||
|
|
'no-websocket')
|
||
|
|
return []
|
||
|
|
return ['websocket']
|
||
|
|
|
||
|
|
def _trigger_event(self, event, *args, **kwargs):
|
||
|
|
"""Invoke an event handler."""
|
||
|
|
run_async = kwargs.pop('run_async', False)
|
||
|
|
if event in self.handlers:
|
||
|
|
if run_async:
|
||
|
|
return self.start_background_task(self.handlers[event], *args)
|
||
|
|
else:
|
||
|
|
try:
|
||
|
|
return self.handlers[event](*args)
|
||
|
|
except:
|
||
|
|
self.logger.exception(event + ' handler error')
|
||
|
|
if event == 'connect':
|
||
|
|
# if connect handler raised error we reject the
|
||
|
|
# connection
|
||
|
|
return False
|
||
|
|
|
||
|
|
def _get_socket(self, sid):
|
||
|
|
"""Return the socket object for a given session."""
|
||
|
|
try:
|
||
|
|
s = self.sockets[sid]
|
||
|
|
except KeyError:
|
||
|
|
raise KeyError('Session not found')
|
||
|
|
if s.closed:
|
||
|
|
del self.sockets[sid]
|
||
|
|
raise KeyError('Session is disconnected')
|
||
|
|
return s
|
||
|
|
|
||
|
|
def _ok(self, packets=None, headers=None, jsonp_index=None):
|
||
|
|
"""Generate a successful HTTP response."""
|
||
|
|
if packets is not None:
|
||
|
|
if headers is None:
|
||
|
|
headers = []
|
||
|
|
headers += [('Content-Type', 'text/plain; charset=UTF-8')]
|
||
|
|
return {'status': '200 OK',
|
||
|
|
'headers': headers,
|
||
|
|
'response': payload.Payload(packets=packets).encode(
|
||
|
|
jsonp_index=jsonp_index).encode('utf-8')}
|
||
|
|
else:
|
||
|
|
return {'status': '200 OK',
|
||
|
|
'headers': [('Content-Type', 'text/plain')],
|
||
|
|
'response': b'OK'}
|
||
|
|
|
||
|
|
def _bad_request(self, message=None):
|
||
|
|
"""Generate a bad request HTTP error response."""
|
||
|
|
if message is None:
|
||
|
|
message = 'Bad Request'
|
||
|
|
message = packet.Packet.json.dumps(message)
|
||
|
|
return {'status': '400 BAD REQUEST',
|
||
|
|
'headers': [('Content-Type', 'text/plain')],
|
||
|
|
'response': message.encode('utf-8')}
|
||
|
|
|
||
|
|
def _method_not_found(self):
|
||
|
|
"""Generate a method not found HTTP error response."""
|
||
|
|
return {'status': '405 METHOD NOT FOUND',
|
||
|
|
'headers': [('Content-Type', 'text/plain')],
|
||
|
|
'response': b'Method Not Found'}
|
||
|
|
|
||
|
|
def _unauthorized(self, message=None):
|
||
|
|
"""Generate a unauthorized HTTP error response."""
|
||
|
|
if message is None:
|
||
|
|
message = 'Unauthorized'
|
||
|
|
message = packet.Packet.json.dumps(message)
|
||
|
|
return {'status': '401 UNAUTHORIZED',
|
||
|
|
'headers': [('Content-Type', 'application/json')],
|
||
|
|
'response': message.encode('utf-8')}
|
||
|
|
|
||
|
|
def _cors_allowed_origins(self, environ):
|
||
|
|
default_origins = []
|
||
|
|
if 'wsgi.url_scheme' in environ and 'HTTP_HOST' in environ:
|
||
|
|
default_origins.append('{scheme}://{host}'.format(
|
||
|
|
scheme=environ['wsgi.url_scheme'], host=environ['HTTP_HOST']))
|
||
|
|
if 'HTTP_X_FORWARDED_PROTO' in environ or \
|
||
|
|
'HTTP_X_FORWARDED_HOST' in environ:
|
||
|
|
scheme = environ.get(
|
||
|
|
'HTTP_X_FORWARDED_PROTO',
|
||
|
|
environ['wsgi.url_scheme']).split(',')[0].strip()
|
||
|
|
default_origins.append('{scheme}://{host}'.format(
|
||
|
|
scheme=scheme, host=environ.get(
|
||
|
|
'HTTP_X_FORWARDED_HOST', environ['HTTP_HOST']).split(
|
||
|
|
',')[0].strip()))
|
||
|
|
if self.cors_allowed_origins is None:
|
||
|
|
allowed_origins = default_origins
|
||
|
|
elif self.cors_allowed_origins == '*':
|
||
|
|
allowed_origins = None
|
||
|
|
elif isinstance(self.cors_allowed_origins, str):
|
||
|
|
allowed_origins = [self.cors_allowed_origins]
|
||
|
|
elif callable(self.cors_allowed_origins):
|
||
|
|
origin = environ.get('HTTP_ORIGIN')
|
||
|
|
allowed_origins = [origin] \
|
||
|
|
if self.cors_allowed_origins(origin) else []
|
||
|
|
else:
|
||
|
|
allowed_origins = self.cors_allowed_origins
|
||
|
|
return allowed_origins
|
||
|
|
|
||
|
|
def _cors_headers(self, environ):
|
||
|
|
"""Return the cross-origin-resource-sharing headers."""
|
||
|
|
if self.cors_allowed_origins == []:
|
||
|
|
# special case, CORS handling is completely disabled
|
||
|
|
return []
|
||
|
|
headers = []
|
||
|
|
allowed_origins = self._cors_allowed_origins(environ)
|
||
|
|
if 'HTTP_ORIGIN' in environ and \
|
||
|
|
(allowed_origins is None or environ['HTTP_ORIGIN'] in
|
||
|
|
allowed_origins):
|
||
|
|
headers = [('Access-Control-Allow-Origin', environ['HTTP_ORIGIN'])]
|
||
|
|
if environ['REQUEST_METHOD'] == 'OPTIONS':
|
||
|
|
headers += [('Access-Control-Allow-Methods', 'OPTIONS, GET, POST')]
|
||
|
|
if 'HTTP_ACCESS_CONTROL_REQUEST_HEADERS' in environ:
|
||
|
|
headers += [('Access-Control-Allow-Headers',
|
||
|
|
environ['HTTP_ACCESS_CONTROL_REQUEST_HEADERS'])]
|
||
|
|
if self.cors_credentials:
|
||
|
|
headers += [('Access-Control-Allow-Credentials', 'true')]
|
||
|
|
return headers
|
||
|
|
|
||
|
|
def _gzip(self, response):
|
||
|
|
"""Apply gzip compression to a response."""
|
||
|
|
bytesio = io.BytesIO()
|
||
|
|
with gzip.GzipFile(fileobj=bytesio, mode='w') as gz:
|
||
|
|
gz.write(response)
|
||
|
|
return bytesio.getvalue()
|
||
|
|
|
||
|
|
def _deflate(self, response):
|
||
|
|
"""Apply deflate compression to a response."""
|
||
|
|
return zlib.compress(response)
|
||
|
|
|
||
|
|
def _log_error_once(self, message, message_key):
|
||
|
|
"""Log message with logging.ERROR level the first time, then log
|
||
|
|
with given level."""
|
||
|
|
if message_key not in self.log_message_keys:
|
||
|
|
self.logger.error(message + ' (further occurrences of this error '
|
||
|
|
'will be logged with level INFO)')
|
||
|
|
self.log_message_keys.add(message_key)
|
||
|
|
else:
|
||
|
|
self.logger.info(message)
|
||
|
|
|
||
|
|
def _service_task(self): # pragma: no cover
|
||
|
|
"""Monitor connected clients and clean up those that time out."""
|
||
|
|
while True:
|
||
|
|
if len(self.sockets) == 0:
|
||
|
|
# nothing to do
|
||
|
|
self.sleep(self.ping_timeout)
|
||
|
|
continue
|
||
|
|
|
||
|
|
# go through the entire client list in a ping interval cycle
|
||
|
|
sleep_interval = float(self.ping_timeout) / len(self.sockets)
|
||
|
|
|
||
|
|
try:
|
||
|
|
# iterate over the current clients
|
||
|
|
for s in self.sockets.copy().values():
|
||
|
|
if not s.closing and not s.closed:
|
||
|
|
s.check_ping_timeout()
|
||
|
|
self.sleep(sleep_interval)
|
||
|
|
except (SystemExit, KeyboardInterrupt):
|
||
|
|
self.logger.info('service task canceled')
|
||
|
|
break
|
||
|
|
except:
|
||
|
|
# an unexpected exception has occurred, log it and continue
|
||
|
|
self.logger.exception('service task exception')
|