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bus/websocket.py

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initial commit
2024-05-03 15:03:07 +03:00
import base64
import functools
import hashlib
import json
import logging
import os
import psycopg2
import random
import socket
import struct
import selectors
import threading
import time
from collections import defaultdict, deque
from contextlib import closing, suppress
from enum import IntEnum
from psycopg2.pool import PoolError
from urllib.parse import urlparse
from weakref import WeakSet
from werkzeug.local import LocalStack
from werkzeug.exceptions import BadRequest, HTTPException, ServiceUnavailable
import odoo
from odoo import api
from .models.bus import dispatch
from odoo.http import root, Request, Response, SessionExpiredException, get_default_session
from odoo.modules.registry import Registry
from odoo.service import model as service_model
from odoo.service.server import CommonServer
from odoo.service.security import check_session
from odoo.tools import config
_logger = logging.getLogger(__name__)
MAX_TRY_ON_POOL_ERROR = 10
DELAY_ON_POOL_ERROR = 0.03
def acquire_cursor(db):
""" Try to acquire a cursor up to `MAX_TRY_ON_POOL_ERROR` """
for tryno in range(1, MAX_TRY_ON_POOL_ERROR + 1):
with suppress(PoolError):
return odoo.registry(db).cursor()
time.sleep(random.uniform(DELAY_ON_POOL_ERROR, DELAY_ON_POOL_ERROR * tryno))
raise PoolError('Failed to acquire cursor after %s retries' % MAX_TRY_ON_POOL_ERROR)
# ------------------------------------------------------
# EXCEPTIONS
# ------------------------------------------------------
class UpgradeRequired(HTTPException):
code = 426
description = "Wrong websocket version was given during the handshake"
def get_headers(self, environ=None):
headers = super().get_headers(environ)
headers.append((
'Sec-WebSocket-Version',
'; '.join(WebsocketConnectionHandler.SUPPORTED_VERSIONS)
))
return headers
class WebsocketException(Exception):
""" Base class for all websockets exceptions """
class ConnectionClosed(WebsocketException):
"""
Raised when the other end closes the socket without performing
the closing handshake.
"""
class InvalidCloseCodeException(WebsocketException):
def __init__(self, code):
super().__init__(f"Invalid close code: {code}")
class InvalidDatabaseException(WebsocketException):
"""
When raised: the database probably does not exists anymore, the
database is corrupted or the database version doesn't match the
server version.
"""
class InvalidStateException(WebsocketException):
"""
Raised when an operation is forbidden in the current state.
"""
class InvalidWebsocketRequest(WebsocketException):
"""
Raised when a websocket request is invalid (format, wrong args).
"""
class PayloadTooLargeException(WebsocketException):
"""
Raised when a websocket message is too large.
"""
class ProtocolError(WebsocketException):
"""
Raised when a frame format doesn't match expectations.
"""
class RateLimitExceededException(Exception):
"""
Raised when a client exceeds the number of request in a given
time.
"""
# ------------------------------------------------------
# WEBSOCKET LIFECYCLE
# ------------------------------------------------------
class LifecycleEvent(IntEnum):
OPEN = 0
CLOSE = 1
# ------------------------------------------------------
# WEBSOCKET
# ------------------------------------------------------
class Opcode(IntEnum):
CONTINUE = 0x00
TEXT = 0x01
BINARY = 0x02
CLOSE = 0x08
PING = 0x09
PONG = 0x0A
class CloseCode(IntEnum):
CLEAN = 1000
GOING_AWAY = 1001
PROTOCOL_ERROR = 1002
INCORRECT_DATA = 1003
ABNORMAL_CLOSURE = 1006
INCONSISTENT_DATA = 1007
MESSAGE_VIOLATING_POLICY = 1008
MESSAGE_TOO_BIG = 1009
EXTENSION_NEGOTIATION_FAILED = 1010
SERVER_ERROR = 1011
RESTART = 1012
TRY_LATER = 1013
BAD_GATEWAY = 1014
SESSION_EXPIRED = 4001
KEEP_ALIVE_TIMEOUT = 4002
class ConnectionState(IntEnum):
OPEN = 0
CLOSING = 1
CLOSED = 2
DATA_OP = {Opcode.TEXT, Opcode.BINARY}
CTRL_OP = {Opcode.CLOSE, Opcode.PING, Opcode.PONG}
HEARTBEAT_OP = {Opcode.PING, Opcode.PONG}
VALID_CLOSE_CODES = {
code for code in CloseCode if code is not CloseCode.ABNORMAL_CLOSURE
}
CLEAN_CLOSE_CODES = {CloseCode.CLEAN, CloseCode.GOING_AWAY, CloseCode.RESTART}
RESERVED_CLOSE_CODES = range(3000, 5000)
_XOR_TABLE = [bytes(a ^ b for a in range(256)) for b in range(256)]
class Frame:
def __init__(
self,
opcode,
payload=b'',
fin=True,
rsv1=False,
rsv2=False,
rsv3=False
):
self.opcode = opcode
self.payload = payload
self.fin = fin
self.rsv1 = rsv1
self.rsv2 = rsv2
self.rsv3 = rsv3
class CloseFrame(Frame):
def __init__(self, code, reason):
if code not in VALID_CLOSE_CODES and code not in RESERVED_CLOSE_CODES:
raise InvalidCloseCodeException(code)
payload = struct.pack('!H', code)
if reason:
payload += reason.encode('utf-8')
self.code = code
self.reason = reason
super().__init__(Opcode.CLOSE, payload)
_websocket_instances = WeakSet()
class Websocket:
__event_callbacks = defaultdict(set)
# Maximum size for a message in bytes, whether it is sent as one
# frame or many fragmented ones.
MESSAGE_MAX_SIZE = 2 ** 20
# Proxies usually close a connection after 1 minute of inactivity.
# Therefore, a PING frame have to be sent if no frame is either sent
# or received within CONNECTION_TIMEOUT - 15 seconds.
CONNECTION_TIMEOUT = 60
INACTIVITY_TIMEOUT = CONNECTION_TIMEOUT - 15
# How many requests can be made in excess of the given rate.
RL_BURST = int(config['websocket_rate_limit_burst'])
# How many seconds between each request.
RL_DELAY = float(config['websocket_rate_limit_delay'])
def __init__(self, sock, session):
# Session linked to the current websocket connection.
self._session = session
self._db = session.db
self.__socket = sock
self._close_sent = False
self._close_received = False
self._timeout_manager = TimeoutManager()
# Used for rate limiting.
self._incoming_frame_timestamps = deque(maxlen=self.RL_BURST)
# Used to notify the websocket that bus notifications are
# available.
self.__notif_sock_w, self.__notif_sock_r = socket.socketpair()
self._channels = set()
self._last_notif_sent_id = 0
# Websocket start up
self.__selector = (
selectors.PollSelector()
if odoo.evented and hasattr(selectors, 'PollSelector')
else selectors.DefaultSelector()
)
self.__selector.register(self.__socket, selectors.EVENT_READ)
self.__selector.register(self.__notif_sock_r, selectors.EVENT_READ)
self.state = ConnectionState.OPEN
_websocket_instances.add(self)
self._trigger_lifecycle_event(LifecycleEvent.OPEN)
# ------------------------------------------------------
# PUBLIC METHODS
# ------------------------------------------------------
def get_messages(self):
while self.state is not ConnectionState.CLOSED:
try:
readables = {
selector_key[0].fileobj for selector_key in
self.__selector.select(self.INACTIVITY_TIMEOUT)
}
if self._timeout_manager.has_timed_out() and self.state is ConnectionState.OPEN:
self.disconnect(
CloseCode.ABNORMAL_CLOSURE
if self._timeout_manager.timeout_reason is TimeoutReason.NO_RESPONSE
else CloseCode.KEEP_ALIVE_TIMEOUT
)
continue
if not readables:
self._send_ping_frame()
continue
if self.__notif_sock_r in readables:
self._dispatch_bus_notifications()
if self.__socket in readables:
message = self._process_next_message()
if message is not None:
yield message
except Exception as exc:
self._handle_transport_error(exc)
def disconnect(self, code, reason=None):
"""
Initiate the closing handshake that is, send a close frame
to the other end which will then send us back an
acknowledgment. Upon the reception of this acknowledgment,
the `_terminate` method will be called to perform an
orderly shutdown. Note that we don't need to wait for the
acknowledgment if the connection was failed beforewards.
"""
if code is not CloseCode.ABNORMAL_CLOSURE:
self._send_close_frame(code, reason)
else:
self._terminate()
@classmethod
def onopen(cls, func):
cls.__event_callbacks[LifecycleEvent.OPEN].add(func)
return func
@classmethod
def onclose(cls, func):
cls.__event_callbacks[LifecycleEvent.CLOSE].add(func)
return func
def subscribe(self, channels, last):
""" Subscribe to bus channels. """
self._channels = channels
if self._last_notif_sent_id < last:
self._last_notif_sent_id = last
# Dispatch past notifications if there are any.
self.trigger_notification_dispatching()
def trigger_notification_dispatching(self):
"""
Warn the socket that notifications are available. Ignore if a
dispatch is already planned or if the socket is already in the
closing state.
"""
if self.state is not ConnectionState.OPEN:
return
readables = {
selector_key[0].fileobj for selector_key in
self.__selector.select(0)
}
if self.__notif_sock_r not in readables:
# Send a random bit to mark the socket as readable.
self.__notif_sock_w.send(b'x')
# ------------------------------------------------------
# PRIVATE METHODS
# ------------------------------------------------------
def _get_next_frame(self):
# 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
# +-+-+-+-+-------+-+-------------+-------------------------------+
# |F|R|R|R| opcode|M| Payload len | Extended payload length |
# |I|S|S|S| (4) |A| (7) | (16/64) |
# |N|V|V|V| |S| | (if payload len==126/127) |
# | |1|2|3| |K| | |
# +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
# | Extended payload length continued, if payload len == 127 |
# + - - - - - - - - - - - - - - - +-------------------------------+
# | |Masking-key, if MASK set to 1 |
# +-------------------------------+-------------------------------+
# | Masking-key (continued) | Payload Data |
# +-------------------------------- - - - - - - - - - - - - - - - +
# : Payload Data continued ... :
# + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
# | Payload Data continued ... |
# +---------------------------------------------------------------+
def recv_bytes(n):
""" Pull n bytes from the socket """
data = bytearray()
while len(data) < n:
received_data = self.__socket.recv(n - len(data))
if not received_data:
raise ConnectionClosed()
data.extend(received_data)
return data
def is_bit_set(byte, n):
"""
Check whether nth bit of byte is set or not (from left
to right).
"""
return byte & (1 << (7 - n))
def apply_mask(payload, mask):
# see: https://www.willmcgugan.com/blog/tech/post/speeding-up-websockets-60x/
a, b, c, d = (_XOR_TABLE[n] for n in mask)
payload[::4] = payload[::4].translate(a)
payload[1::4] = payload[1::4].translate(b)
payload[2::4] = payload[2::4].translate(c)
payload[3::4] = payload[3::4].translate(d)
return payload
self._limit_rate()
first_byte, second_byte = recv_bytes(2)
fin, rsv1, rsv2, rsv3 = (is_bit_set(first_byte, n) for n in range(4))
try:
opcode = Opcode(first_byte & 0b00001111)
except ValueError as exc:
raise ProtocolError(exc)
payload_length = second_byte & 0b01111111
if rsv1 or rsv2 or rsv3:
raise ProtocolError("Reserved bits must be unset")
if not is_bit_set(second_byte, 0):
raise ProtocolError("Frame must be masked")
if opcode in CTRL_OP:
if not fin:
raise ProtocolError("Control frames cannot be fragmented")
if payload_length > 125:
raise ProtocolError(
"Control frames payload must be smaller than 126"
)
if payload_length == 126:
payload_length = struct.unpack('!H', recv_bytes(2))[0]
elif payload_length == 127:
payload_length = struct.unpack('!Q', recv_bytes(8))[0]
if payload_length > self.MESSAGE_MAX_SIZE:
raise PayloadTooLargeException()
mask = recv_bytes(4)
payload = apply_mask(recv_bytes(payload_length), mask)
frame = Frame(opcode, bytes(payload), fin, rsv1, rsv2, rsv3)
self._timeout_manager.acknowledge_frame_receipt(frame)
return frame
def _process_next_message(self):
"""
Process the next message coming throught the socket. If a
data message can be extracted, return its decoded payload.
As per the RFC, only control frames will be processed once
the connection reaches the closing state.
"""
frame = self._get_next_frame()
if frame.opcode in CTRL_OP:
self._handle_control_frame(frame)
return
if self.state is not ConnectionState.OPEN:
# After receiving a control frame indicating the connection
# should be closed, a peer discards any further data
# received.
return
if frame.opcode is Opcode.CONTINUE:
raise ProtocolError("Unexpected continuation frame")
message = frame.payload
if not frame.fin:
message = self._recover_fragmented_message(frame)
return (
message.decode('utf-8')
if message is not None and frame.opcode is Opcode.TEXT else message
)
def _recover_fragmented_message(self, initial_frame):
message_fragments = bytearray(initial_frame.payload)
while True:
frame = self._get_next_frame()
if frame.opcode in CTRL_OP:
# Control frames can be received in the middle of a
# fragmented message, process them as soon as possible.
self._handle_control_frame(frame)
if self.state is not ConnectionState.OPEN:
return
continue
if frame.opcode is not Opcode.CONTINUE:
raise ProtocolError("A continuation frame was expected")
message_fragments.extend(frame.payload)
if len(message_fragments) > self.MESSAGE_MAX_SIZE:
raise PayloadTooLargeException()
if frame.fin:
return bytes(message_fragments)
def _send(self, message):
if self.state is not ConnectionState.OPEN:
raise InvalidStateException(
"Trying to send a frame on a closed socket"
)
opcode = Opcode.BINARY
if not isinstance(message, (bytes, bytearray)):
opcode = Opcode.TEXT
self._send_frame(Frame(opcode, message))
def _send_frame(self, frame):
if frame.opcode in CTRL_OP and len(frame.payload) > 125:
raise ProtocolError(
"Control frames should have a payload length smaller than 126"
)
if isinstance(frame.payload, str):
frame.payload = frame.payload.encode('utf-8')
elif not isinstance(frame.payload, (bytes, bytearray)):
frame.payload = json.dumps(frame.payload).encode('utf-8')
output = bytearray()
first_byte = (
(0b10000000 if frame.fin else 0)
| (0b01000000 if frame.rsv1 else 0)
| (0b00100000 if frame.rsv2 else 0)
| (0b00010000 if frame.rsv3 else 0)
| frame.opcode
)
payload_length = len(frame.payload)
if payload_length < 126:
output.extend(
struct.pack('!BB', first_byte, payload_length)
)
elif payload_length < 65536:
output.extend(
struct.pack('!BBH', first_byte, 126, payload_length)
)
else:
output.extend(
struct.pack('!BBQ', first_byte, 127, payload_length)
)
output.extend(frame.payload)
self.__socket.sendall(output)
self._timeout_manager.acknowledge_frame_sent(frame)
if not isinstance(frame, CloseFrame):
return
self.state = ConnectionState.CLOSING
self._close_sent = True
if frame.code not in CLEAN_CLOSE_CODES or self._close_received:
return self._terminate()
# After sending a control frame indicating the connection
# should be closed, a peer does not send any further data.
self.__selector.unregister(self.__notif_sock_r)
def _send_close_frame(self, code, reason=None):
""" Send a close frame. """
self._send_frame(CloseFrame(code, reason))
def _send_ping_frame(self):
""" Send a ping frame """
self._send_frame(Frame(Opcode.PING))
def _send_pong_frame(self, payload):
""" Send a pong frame """
self._send_frame(Frame(Opcode.PONG, payload))
def _terminate(self):
""" Close the underlying TCP socket. """
with suppress(OSError, TimeoutError):
self.__socket.shutdown(socket.SHUT_WR)
# Call recv until obtaining a return value of 0 indicating
# the other end has performed an orderly shutdown. A timeout
# is set to ensure the connection will be closed even if
# the other end does not close the socket properly.
self.__socket.settimeout(1)
while self.__socket.recv(4096):
pass
self.__selector.unregister(self.__socket)
self.__selector.close()
self.__socket.close()
self.state = ConnectionState.CLOSED
dispatch.unsubscribe(self)
self._trigger_lifecycle_event(LifecycleEvent.CLOSE)
def _handle_control_frame(self, frame):
if frame.opcode is Opcode.PING:
self._send_pong_frame(frame.payload)
elif frame.opcode is Opcode.CLOSE:
self.state = ConnectionState.CLOSING
self._close_received = True
code, reason = CloseCode.CLEAN, None
if len(frame.payload) >= 2:
code = struct.unpack('!H', frame.payload[:2])[0]
reason = frame.payload[2:].decode('utf-8')
elif frame.payload:
raise ProtocolError("Malformed closing frame")
if not self._close_sent:
self._send_close_frame(code, reason)
else:
self._terminate()
def _handle_transport_error(self, exc):
"""
Find out which close code should be sent according to given
exception and call `self.disconnect` in order to close the
connection cleanly.
"""
code, reason = CloseCode.SERVER_ERROR, str(exc)
if isinstance(exc, (ConnectionClosed, OSError)):
code = CloseCode.ABNORMAL_CLOSURE
elif isinstance(exc, (ProtocolError, InvalidCloseCodeException)):
code = CloseCode.PROTOCOL_ERROR
elif isinstance(exc, UnicodeDecodeError):
code = CloseCode.INCONSISTENT_DATA
elif isinstance(exc, PayloadTooLargeException):
code = CloseCode.MESSAGE_TOO_BIG
elif isinstance(exc, (PoolError, RateLimitExceededException)):
code = CloseCode.TRY_LATER
elif isinstance(exc, SessionExpiredException):
code = CloseCode.SESSION_EXPIRED
if code is CloseCode.SERVER_ERROR:
reason = None
registry = Registry(self._session.db)
sequence = registry.registry_sequence
registry = registry.check_signaling()
if sequence != registry.registry_sequence:
_logger.warning("Bus operation aborted; registry has been reloaded")
else:
_logger.error(exc, exc_info=True)
self.disconnect(code, reason)
def _limit_rate(self):
"""
This method is a simple rate limiter designed not to allow
more than one request by `RL_DELAY` seconds. `RL_BURST` specify
how many requests can be made in excess of the given rate at the
begining. When requests are received too fast, raises the
`RateLimitExceededException`.
"""
now = time.time()
if len(self._incoming_frame_timestamps) >= self.RL_BURST:
elapsed_time = now - self._incoming_frame_timestamps[0]
if elapsed_time < self.RL_DELAY * self.RL_BURST:
raise RateLimitExceededException()
self._incoming_frame_timestamps.append(now)
def _trigger_lifecycle_event(self, event_type):
"""
Trigger a lifecycle event that is, call every function
registered for this event type. Every callback is given both the
environment and the related websocket.
"""
if not self.__event_callbacks[event_type]:
return
with closing(acquire_cursor(self._db)) as cr:
env = api.Environment(cr, self._session.uid, self._session.context)
for callback in self.__event_callbacks[event_type]:
try:
service_model.retrying(functools.partial(callback, env, self), env)
except Exception:
_logger.warning(
'Error during Websocket %s callback',
LifecycleEvent(event_type).name,
exc_info=True
)
def _dispatch_bus_notifications(self):
"""
Dispatch notifications related to the registered channels. If
the session is expired, close the connection with the
`SESSION_EXPIRED` close code. If no cursor can be acquired,
close the connection with the `TRY_LATER` close code.
"""
session = root.session_store.get(self._session.sid)
if not session:
raise SessionExpiredException()
with acquire_cursor(session.db) as cr:
env = api.Environment(cr, session.uid, session.context)
if session.uid is not None and not check_session(session, env):
raise SessionExpiredException()
# Mark the notification request as processed.
self.__notif_sock_r.recv(1)
notifications = env['bus.bus']._poll(self._channels, self._last_notif_sent_id)
if not notifications:
return
self._last_notif_sent_id = notifications[-1]['id']
self._send(notifications)
class TimeoutReason(IntEnum):
KEEP_ALIVE = 0
NO_RESPONSE = 1
class TimeoutManager:
"""
This class handles the Websocket timeouts. If no response to a
PING/CLOSE frame is received after `TIMEOUT` seconds or if the
connection is opened for more than `self._keep_alive_timeout` seconds,
the connection is considered to have timed out. To determine if the
connection has timed out, use the `has_timed_out` method.
"""
TIMEOUT = 15
# Timeout specifying how many seconds the connection should be kept
# alive.
KEEP_ALIVE_TIMEOUT = int(config['websocket_keep_alive_timeout'])
def __init__(self):
super().__init__()
self._awaited_opcode = None
# Time in which the connection was opened.
self._opened_at = time.time()
# Custom keep alive timeout for each TimeoutManager to avoid multiple
# connections timing out at the same time.
self._keep_alive_timeout = (
self.KEEP_ALIVE_TIMEOUT + random.uniform(0, self.KEEP_ALIVE_TIMEOUT / 2)
)
self.timeout_reason = None
# Start time recorded when we started awaiting an answer to a
# PING/CLOSE frame.
self._waiting_start_time = None
def acknowledge_frame_receipt(self, frame):
if self._awaited_opcode is frame.opcode:
self._awaited_opcode = None
self._waiting_start_time = None
def acknowledge_frame_sent(self, frame):
"""
Acknowledge a frame was sent. If this frame is a PING/CLOSE
frame, start waiting for an answer.
"""
if self.has_timed_out():
return
if frame.opcode is Opcode.PING:
self._awaited_opcode = Opcode.PONG
elif frame.opcode is Opcode.CLOSE:
self._awaited_opcode = Opcode.CLOSE
if self._awaited_opcode is not None:
self._waiting_start_time = time.time()
def has_timed_out(self):
"""
Determine whether the connection has timed out or not. The
connection times out when the answer to a CLOSE/PING frame
is not received within `TIMEOUT` seconds or if the connection
is opened for more than `self._keep_alive_timeout` seconds.
"""
now = time.time()
if now - self._opened_at >= self._keep_alive_timeout:
self.timeout_reason = TimeoutReason.KEEP_ALIVE
return True
if self._awaited_opcode and now - self._waiting_start_time >= self.TIMEOUT:
self.timeout_reason = TimeoutReason.NO_RESPONSE
return True
return False
# ------------------------------------------------------
# WEBSOCKET SERVING
# ------------------------------------------------------
_wsrequest_stack = LocalStack()
wsrequest = _wsrequest_stack()
class WebsocketRequest:
def __init__(self, db, httprequest, websocket):
self.db = db
self.httprequest = httprequest
self.session = None
self.ws = websocket
def __enter__(self):
_wsrequest_stack.push(self)
return self
def __exit__(self, *args):
_wsrequest_stack.pop()
def serve_websocket_message(self, message):
try:
jsonrequest = json.loads(message)
event_name = jsonrequest['event_name'] # mandatory
except KeyError as exc:
raise InvalidWebsocketRequest(
f'Key {exc.args[0]!r} is missing from request'
) from exc
except ValueError as exc:
raise InvalidWebsocketRequest(
f'Invalid JSON data, {exc.args[0]}'
) from exc
data = jsonrequest.get('data')
self.session = self._get_session()
try:
self.registry = Registry(self.db)
self.registry.check_signaling()
except (
AttributeError, psycopg2.OperationalError, psycopg2.ProgrammingError
) as exc:
raise InvalidDatabaseException() from exc
with closing(acquire_cursor(self.db)) as cr:
self.env = api.Environment(cr, self.session.uid, self.session.context)
threading.current_thread().uid = self.env.uid
service_model.retrying(
functools.partial(self._serve_ir_websocket, event_name, data),
self.env,
)
def _serve_ir_websocket(self, event_name, data):
"""
Delegate most of the processing to the ir.websocket model
which is extensible by applications. Directly call the
appropriate ir.websocket method since only two events are
tolerated: `subscribe` and `update_presence`.
"""
self.env['ir.websocket']._authenticate()
if event_name == 'subscribe':
self.env['ir.websocket']._subscribe(data)
if event_name == 'update_presence':
self.env['ir.websocket']._update_bus_presence(**data)
def _get_session(self):
session = root.session_store.get(self.ws._session.sid)
if not session:
raise SessionExpiredException()
return session
def update_env(self, user=None, context=None, su=None):
"""
Update the environment of the current websocket request.
"""
Request.update_env(self, user, context, su)
def update_context(self, **overrides):
"""
Override the environment context of the current request with the
values of ``overrides``. To replace the entire context, please
use :meth:`~update_env` instead.
"""
self.update_env(context=dict(self.env.context, **overrides))
class WebsocketConnectionHandler:
SUPPORTED_VERSIONS = {'13'}
# Given by the RFC in order to generate Sec-WebSocket-Accept from
# Sec-WebSocket-Key value.
_HANDSHAKE_GUID = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
_REQUIRED_HANDSHAKE_HEADERS = {
'connection', 'host', 'sec-websocket-key',
'sec-websocket-version', 'upgrade', 'origin',
}
@classmethod
def websocket_allowed(cls, request):
return not request.registry.in_test_mode()
@classmethod
def open_connection(cls, request):
"""
Open a websocket connection if the handshake is successfull.
:return: Response indicating the server performed a connection
upgrade.
:raise: UpgradeRequired if there is no intersection between the
versions the client supports and those we support.
:raise: BadRequest if the handshake data is incorrect.
"""
if not cls.websocket_allowed(request):
raise ServiceUnavailable("Websocket is disabled in test mode")
cls._handle_public_configuration(request)
try:
response = cls._get_handshake_response(request.httprequest.headers)
socket = request.httprequest._HTTPRequest__environ['socket']
session, db, httprequest = request.session, request.db, request.httprequest
response.call_on_close(lambda: cls._serve_forever(
Websocket(socket, session),
db,
httprequest,
))
# Force save the session. Session must be persisted to handle
# WebSocket authentication.
request.session.is_dirty = True
return response
except KeyError as exc:
raise RuntimeError(
f"Couldn't bind the websocket. Is the connection opened on the evented port ({config['gevent_port']})?"
) from exc
except HTTPException as exc:
# The HTTP stack does not log exceptions derivated from the
# HTTPException class since they are valid responses.
_logger.error(exc)
raise
@classmethod
def _get_handshake_response(cls, headers):
"""
:return: Response indicating the server performed a connection
upgrade.
:raise: BadRequest
:raise: UpgradeRequired
"""
cls._assert_handshake_validity(headers)
# sha-1 is used as it is required by
# https://datatracker.ietf.org/doc/html/rfc6455#page-7
accept_header = hashlib.sha1(
(headers['sec-websocket-key'] + cls._HANDSHAKE_GUID).encode()).digest()
accept_header = base64.b64encode(accept_header)
return Response(status=101, headers={
'Upgrade': 'websocket',
'Connection': 'Upgrade',
'Sec-WebSocket-Accept': accept_header.decode(),
})
@classmethod
def _handle_public_configuration(cls, request):
if not os.getenv('ODOO_BUS_PUBLIC_SAMESITE_WS'):
return
headers = request.httprequest.headers
origin_url = urlparse(headers.get('origin'))
if origin_url.netloc != headers.get('host') or origin_url.scheme != request.httprequest.scheme:
request.session = root.session_store.new()
request.session.update(get_default_session(), db=request.session.db)
request.session.is_explicit = True
@classmethod
def _assert_handshake_validity(cls, headers):
"""
:raise: UpgradeRequired if there is no intersection between
the version the client supports and those we support.
:raise: BadRequest in case of invalid handshake.
"""
missing_or_empty_headers = {
header for header in cls._REQUIRED_HANDSHAKE_HEADERS
if header not in headers
}
if missing_or_empty_headers:
raise BadRequest(
f"""Empty or missing header(s): {', '.join(missing_or_empty_headers)}"""
)
if headers['upgrade'].lower() != 'websocket':
raise BadRequest('Invalid upgrade header')
if 'upgrade' not in headers['connection'].lower():
raise BadRequest('Invalid connection header')
if headers['sec-websocket-version'] not in cls.SUPPORTED_VERSIONS:
raise UpgradeRequired()
key = headers['sec-websocket-key']
try:
decoded_key = base64.b64decode(key, validate=True)
except ValueError:
raise BadRequest("Sec-WebSocket-Key should be b64 encoded")
if len(decoded_key) != 16:
raise BadRequest(
"Sec-WebSocket-Key should be of length 16 once decoded"
)
@classmethod
def _serve_forever(cls, websocket, db, httprequest):
"""
Process incoming messages and dispatch them to the application.
"""
current_thread = threading.current_thread()
current_thread.type = 'websocket'
for message in websocket.get_messages():
with WebsocketRequest(db, httprequest, websocket) as req:
try:
req.serve_websocket_message(message)
except SessionExpiredException:
websocket.disconnect(CloseCode.SESSION_EXPIRED)
except PoolError:
websocket.disconnect(CloseCode.TRY_LATER)
except Exception:
_logger.exception("Exception occurred during websocket request handling")
def _kick_all():
""" Disconnect all the websocket instances. """
for websocket in _websocket_instances:
if websocket.state is ConnectionState.OPEN:
websocket.disconnect(CloseCode.GOING_AWAY)
CommonServer.on_stop(_kick_all)
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