976 lines
36 KiB
Python
976 lines
36 KiB
Python
from __future__ import annotations
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import asyncio
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import hmac
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import http
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import logging
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import socket
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import sys
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from collections.abc import Awaitable, Generator, Iterable, Sequence
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from types import TracebackType
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from typing import Any, Callable, cast
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from ..exceptions import InvalidHeader
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from ..extensions.base import ServerExtensionFactory
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from ..extensions.permessage_deflate import enable_server_permessage_deflate
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from ..frames import CloseCode
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from ..headers import (
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build_www_authenticate_basic,
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parse_authorization_basic,
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validate_subprotocols,
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)
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from ..http11 import SERVER, Request, Response
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from ..protocol import CONNECTING, OPEN, Event
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from ..server import ServerProtocol
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from ..typing import LoggerLike, Origin, StatusLike, Subprotocol
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from .compatibility import asyncio_timeout
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from .connection import Connection, broadcast
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__all__ = [
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"broadcast",
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"serve",
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"unix_serve",
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"ServerConnection",
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"Server",
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"basic_auth",
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]
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class ServerConnection(Connection):
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"""
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:mod:`asyncio` implementation of a WebSocket server connection.
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:class:`ServerConnection` provides :meth:`recv` and :meth:`send` methods for
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receiving and sending messages.
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It supports asynchronous iteration to receive messages::
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async for message in websocket:
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await process(message)
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The iterator exits normally when the connection is closed with close code
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1000 (OK) or 1001 (going away) or without a close code. It raises a
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:exc:`~websockets.exceptions.ConnectionClosedError` when the connection is
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closed with any other code.
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The ``ping_interval``, ``ping_timeout``, ``close_timeout``, ``max_queue``,
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and ``write_limit`` arguments have the same meaning as in :func:`serve`.
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Args:
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protocol: Sans-I/O connection.
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server: Server that manages this connection.
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"""
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def __init__(
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self,
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protocol: ServerProtocol,
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server: Server,
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*,
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ping_interval: float | None = 20,
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ping_timeout: float | None = 20,
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close_timeout: float | None = 10,
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max_queue: int | None | tuple[int | None, int | None] = 16,
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write_limit: int | tuple[int, int | None] = 2**15,
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) -> None:
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self.protocol: ServerProtocol
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super().__init__(
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protocol,
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ping_interval=ping_interval,
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ping_timeout=ping_timeout,
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close_timeout=close_timeout,
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max_queue=max_queue,
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write_limit=write_limit,
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)
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self.server = server
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self.request_rcvd: asyncio.Future[None] = self.loop.create_future()
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self.username: str # see basic_auth()
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def respond(self, status: StatusLike, text: str) -> Response:
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"""
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Create a plain text HTTP response.
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``process_request`` and ``process_response`` may call this method to
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return an HTTP response instead of performing the WebSocket opening
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handshake.
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You can modify the response before returning it, for example by changing
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HTTP headers.
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Args:
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status: HTTP status code.
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text: HTTP response body; it will be encoded to UTF-8.
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Returns:
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HTTP response to send to the client.
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"""
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return self.protocol.reject(status, text)
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async def handshake(
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self,
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process_request: (
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Callable[
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[ServerConnection, Request],
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Awaitable[Response | None] | Response | None,
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]
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| None
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) = None,
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process_response: (
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Callable[
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[ServerConnection, Request, Response],
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Awaitable[Response | None] | Response | None,
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]
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| None
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) = None,
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server_header: str | None = SERVER,
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) -> None:
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"""
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Perform the opening handshake.
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"""
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await asyncio.wait(
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[self.request_rcvd, self.connection_lost_waiter],
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return_when=asyncio.FIRST_COMPLETED,
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)
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if self.request is not None:
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async with self.send_context(expected_state=CONNECTING):
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response = None
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if process_request is not None:
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try:
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response = process_request(self, self.request)
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if isinstance(response, Awaitable):
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response = await response
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except Exception as exc:
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self.protocol.handshake_exc = exc
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response = self.protocol.reject(
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http.HTTPStatus.INTERNAL_SERVER_ERROR,
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(
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"Failed to open a WebSocket connection.\n"
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"See server log for more information.\n"
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),
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)
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if response is None:
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if self.server.is_serving():
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self.response = self.protocol.accept(self.request)
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else:
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self.response = self.protocol.reject(
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http.HTTPStatus.SERVICE_UNAVAILABLE,
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"Server is shutting down.\n",
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)
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else:
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assert isinstance(response, Response) # help mypy
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self.response = response
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if server_header:
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self.response.headers["Server"] = server_header
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response = None
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if process_response is not None:
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try:
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response = process_response(self, self.request, self.response)
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if isinstance(response, Awaitable):
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response = await response
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except Exception as exc:
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self.protocol.handshake_exc = exc
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response = self.protocol.reject(
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http.HTTPStatus.INTERNAL_SERVER_ERROR,
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(
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"Failed to open a WebSocket connection.\n"
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"See server log for more information.\n"
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),
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)
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if response is not None:
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assert isinstance(response, Response) # help mypy
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self.response = response
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self.protocol.send_response(self.response)
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# self.protocol.handshake_exc is set when the connection is lost before
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# receiving a request, when the request cannot be parsed, or when the
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# handshake fails, including when process_request or process_response
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# raises an exception.
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# It isn't set when process_request or process_response sends an HTTP
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# response that rejects the handshake.
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if self.protocol.handshake_exc is not None:
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raise self.protocol.handshake_exc
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def process_event(self, event: Event) -> None:
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"""
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Process one incoming event.
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"""
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# First event - handshake request.
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if self.request is None:
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assert isinstance(event, Request)
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self.request = event
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self.request_rcvd.set_result(None)
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# Later events - frames.
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else:
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super().process_event(event)
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def connection_made(self, transport: asyncio.BaseTransport) -> None:
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super().connection_made(transport)
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self.server.start_connection_handler(self)
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class Server:
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"""
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WebSocket server returned by :func:`serve`.
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This class mirrors the API of :class:`asyncio.Server`.
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It keeps track of WebSocket connections in order to close them properly
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when shutting down.
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Args:
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handler: Connection handler. It receives the WebSocket connection,
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which is a :class:`ServerConnection`, in argument.
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process_request: Intercept the request during the opening handshake.
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Return an HTTP response to force the response. Return :obj:`None` to
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continue normally. When you force an HTTP 101 Continue response, the
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handshake is successful. Else, the connection is aborted.
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``process_request`` may be a function or a coroutine.
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process_response: Intercept the response during the opening handshake.
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Modify the response or return a new HTTP response to force the
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response. Return :obj:`None` to continue normally. When you force an
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HTTP 101 Continue response, the handshake is successful. Else, the
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connection is aborted. ``process_response`` may be a function or a
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coroutine.
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server_header: Value of the ``Server`` response header.
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It defaults to ``"Python/x.y.z websockets/X.Y"``. Setting it to
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:obj:`None` removes the header.
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open_timeout: Timeout for opening connections in seconds.
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:obj:`None` disables the timeout.
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logger: Logger for this server.
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It defaults to ``logging.getLogger("websockets.server")``.
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See the :doc:`logging guide <../../topics/logging>` for details.
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"""
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def __init__(
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self,
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handler: Callable[[ServerConnection], Awaitable[None]],
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*,
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process_request: (
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Callable[
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[ServerConnection, Request],
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Awaitable[Response | None] | Response | None,
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||
]
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||
| None
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) = None,
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process_response: (
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Callable[
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[ServerConnection, Request, Response],
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Awaitable[Response | None] | Response | None,
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||
]
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| None
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) = None,
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server_header: str | None = SERVER,
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||
open_timeout: float | None = 10,
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||
logger: LoggerLike | None = None,
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||
) -> None:
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self.loop = asyncio.get_running_loop()
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self.handler = handler
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self.process_request = process_request
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self.process_response = process_response
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self.server_header = server_header
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self.open_timeout = open_timeout
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if logger is None:
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logger = logging.getLogger("websockets.server")
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self.logger = logger
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# Keep track of active connections.
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self.handlers: dict[ServerConnection, asyncio.Task[None]] = {}
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# Task responsible for closing the server and terminating connections.
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self.close_task: asyncio.Task[None] | None = None
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||
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# Completed when the server is closed and connections are terminated.
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self.closed_waiter: asyncio.Future[None] = self.loop.create_future()
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||
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@property
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def connections(self) -> set[ServerConnection]:
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"""
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||
Set of active connections.
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||
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This property contains all connections that completed the opening
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handshake successfully and didn't start the closing handshake yet.
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It can be useful in combination with :func:`~broadcast`.
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"""
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return {connection for connection in self.handlers if connection.state is OPEN}
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def wrap(self, server: asyncio.Server) -> None:
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"""
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||
Attach to a given :class:`asyncio.Server`.
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||
Since :meth:`~asyncio.loop.create_server` doesn't support injecting a
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custom ``Server`` class, the easiest solution that doesn't rely on
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||
private :mod:`asyncio` APIs is to:
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||
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- instantiate a :class:`Server`
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- give the protocol factory a reference to that instance
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- call :meth:`~asyncio.loop.create_server` with the factory
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- attach the resulting :class:`asyncio.Server` with this method
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||
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"""
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self.server = server
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for sock in server.sockets:
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if sock.family == socket.AF_INET:
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name = "%s:%d" % sock.getsockname()
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elif sock.family == socket.AF_INET6:
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name = "[%s]:%d" % sock.getsockname()[:2]
|
||
elif sock.family == socket.AF_UNIX:
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name = sock.getsockname()
|
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# In the unlikely event that someone runs websockets over a
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# protocol other than IP or Unix sockets, avoid crashing.
|
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else: # pragma: no cover
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||
name = str(sock.getsockname())
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self.logger.info("server listening on %s", name)
|
||
|
||
async def conn_handler(self, connection: ServerConnection) -> None:
|
||
"""
|
||
Handle the lifecycle of a WebSocket connection.
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||
|
||
Since this method doesn't have a caller that can handle exceptions,
|
||
it attempts to log relevant ones.
|
||
|
||
It guarantees that the TCP connection is closed before exiting.
|
||
|
||
"""
|
||
try:
|
||
async with asyncio_timeout(self.open_timeout):
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||
try:
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||
await connection.handshake(
|
||
self.process_request,
|
||
self.process_response,
|
||
self.server_header,
|
||
)
|
||
except asyncio.CancelledError:
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||
connection.close_transport()
|
||
raise
|
||
except Exception:
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||
connection.logger.error("opening handshake failed", exc_info=True)
|
||
connection.close_transport()
|
||
return
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||
|
||
if connection.protocol.state is not OPEN:
|
||
# process_request or process_response rejected the handshake.
|
||
connection.close_transport()
|
||
return
|
||
|
||
try:
|
||
connection.start_keepalive()
|
||
await self.handler(connection)
|
||
except Exception:
|
||
connection.logger.error("connection handler failed", exc_info=True)
|
||
await connection.close(CloseCode.INTERNAL_ERROR)
|
||
else:
|
||
await connection.close()
|
||
|
||
except TimeoutError:
|
||
# When the opening handshake times out, there's nothing to log.
|
||
pass
|
||
|
||
except Exception: # pragma: no cover
|
||
# Don't leak connections on unexpected errors.
|
||
connection.transport.abort()
|
||
|
||
finally:
|
||
# Registration is tied to the lifecycle of conn_handler() because
|
||
# the server waits for connection handlers to terminate, even if
|
||
# all connections are already closed.
|
||
del self.handlers[connection]
|
||
|
||
def start_connection_handler(self, connection: ServerConnection) -> None:
|
||
"""
|
||
Register a connection with this server.
|
||
|
||
"""
|
||
# The connection must be registered in self.handlers immediately.
|
||
# If it was registered in conn_handler(), a race condition could
|
||
# happen when closing the server after scheduling conn_handler()
|
||
# but before it starts executing.
|
||
self.handlers[connection] = self.loop.create_task(self.conn_handler(connection))
|
||
|
||
def close(self, close_connections: bool = True) -> None:
|
||
"""
|
||
Close the server.
|
||
|
||
* Close the underlying :class:`asyncio.Server`.
|
||
* When ``close_connections`` is :obj:`True`, which is the default,
|
||
close existing connections. Specifically:
|
||
|
||
* Reject opening WebSocket connections with an HTTP 503 (service
|
||
unavailable) error. This happens when the server accepted the TCP
|
||
connection but didn't complete the opening handshake before closing.
|
||
* Close open WebSocket connections with close code 1001 (going away).
|
||
|
||
* Wait until all connection handlers terminate.
|
||
|
||
:meth:`close` is idempotent.
|
||
|
||
"""
|
||
if self.close_task is None:
|
||
self.close_task = self.get_loop().create_task(
|
||
self._close(close_connections)
|
||
)
|
||
|
||
async def _close(self, close_connections: bool) -> None:
|
||
"""
|
||
Implementation of :meth:`close`.
|
||
|
||
This calls :meth:`~asyncio.Server.close` on the underlying
|
||
:class:`asyncio.Server` object to stop accepting new connections and
|
||
then closes open connections with close code 1001.
|
||
|
||
"""
|
||
self.logger.info("server closing")
|
||
|
||
# Stop accepting new connections.
|
||
self.server.close()
|
||
|
||
# Wait until all accepted connections reach connection_made() and call
|
||
# register(). See https://github.com/python/cpython/issues/79033 for
|
||
# details. This workaround can be removed when dropping Python < 3.11.
|
||
await asyncio.sleep(0)
|
||
|
||
if close_connections:
|
||
# Close OPEN connections with close code 1001. After server.close(),
|
||
# handshake() closes OPENING connections with an HTTP 503 error.
|
||
close_tasks = [
|
||
asyncio.create_task(connection.close(1001))
|
||
for connection in self.handlers
|
||
if connection.protocol.state is not CONNECTING
|
||
]
|
||
# asyncio.wait doesn't accept an empty first argument.
|
||
if close_tasks:
|
||
await asyncio.wait(close_tasks)
|
||
|
||
# Wait until all TCP connections are closed.
|
||
await self.server.wait_closed()
|
||
|
||
# Wait until all connection handlers terminate.
|
||
# asyncio.wait doesn't accept an empty first argument.
|
||
if self.handlers:
|
||
await asyncio.wait(self.handlers.values())
|
||
|
||
# Tell wait_closed() to return.
|
||
self.closed_waiter.set_result(None)
|
||
|
||
self.logger.info("server closed")
|
||
|
||
async def wait_closed(self) -> None:
|
||
"""
|
||
Wait until the server is closed.
|
||
|
||
When :meth:`wait_closed` returns, all TCP connections are closed and
|
||
all connection handlers have returned.
|
||
|
||
To ensure a fast shutdown, a connection handler should always be
|
||
awaiting at least one of:
|
||
|
||
* :meth:`~ServerConnection.recv`: when the connection is closed,
|
||
it raises :exc:`~websockets.exceptions.ConnectionClosedOK`;
|
||
* :meth:`~ServerConnection.wait_closed`: when the connection is
|
||
closed, it returns.
|
||
|
||
Then the connection handler is immediately notified of the shutdown;
|
||
it can clean up and exit.
|
||
|
||
"""
|
||
await asyncio.shield(self.closed_waiter)
|
||
|
||
def get_loop(self) -> asyncio.AbstractEventLoop:
|
||
"""
|
||
See :meth:`asyncio.Server.get_loop`.
|
||
|
||
"""
|
||
return self.server.get_loop()
|
||
|
||
def is_serving(self) -> bool: # pragma: no cover
|
||
"""
|
||
See :meth:`asyncio.Server.is_serving`.
|
||
|
||
"""
|
||
return self.server.is_serving()
|
||
|
||
async def start_serving(self) -> None: # pragma: no cover
|
||
"""
|
||
See :meth:`asyncio.Server.start_serving`.
|
||
|
||
Typical use::
|
||
|
||
server = await serve(..., start_serving=False)
|
||
# perform additional setup here...
|
||
# ... then start the server
|
||
await server.start_serving()
|
||
|
||
"""
|
||
await self.server.start_serving()
|
||
|
||
async def serve_forever(self) -> None: # pragma: no cover
|
||
"""
|
||
See :meth:`asyncio.Server.serve_forever`.
|
||
|
||
Typical use::
|
||
|
||
server = await serve(...)
|
||
# this coroutine doesn't return
|
||
# canceling it stops the server
|
||
await server.serve_forever()
|
||
|
||
This is an alternative to using :func:`serve` as an asynchronous context
|
||
manager. Shutdown is triggered by canceling :meth:`serve_forever`
|
||
instead of exiting a :func:`serve` context.
|
||
|
||
"""
|
||
await self.server.serve_forever()
|
||
|
||
@property
|
||
def sockets(self) -> Iterable[socket.socket]:
|
||
"""
|
||
See :attr:`asyncio.Server.sockets`.
|
||
|
||
"""
|
||
return self.server.sockets
|
||
|
||
async def __aenter__(self) -> Server: # pragma: no cover
|
||
return self
|
||
|
||
async def __aexit__(
|
||
self,
|
||
exc_type: type[BaseException] | None,
|
||
exc_value: BaseException | None,
|
||
traceback: TracebackType | None,
|
||
) -> None: # pragma: no cover
|
||
self.close()
|
||
await self.wait_closed()
|
||
|
||
|
||
# This is spelled in lower case because it's exposed as a callable in the API.
|
||
class serve:
|
||
"""
|
||
Create a WebSocket server listening on ``host`` and ``port``.
|
||
|
||
Whenever a client connects, the server creates a :class:`ServerConnection`,
|
||
performs the opening handshake, and delegates to the ``handler`` coroutine.
|
||
|
||
The handler receives the :class:`ServerConnection` instance, which you can
|
||
use to send and receive messages.
|
||
|
||
Once the handler completes, either normally or with an exception, the server
|
||
performs the closing handshake and closes the connection.
|
||
|
||
This coroutine returns a :class:`Server` whose API mirrors
|
||
:class:`asyncio.Server`. Treat it as an asynchronous context manager to
|
||
ensure that the server will be closed::
|
||
|
||
from websockets.asyncio.server import serve
|
||
|
||
def handler(websocket):
|
||
...
|
||
|
||
# set this future to exit the server
|
||
stop = asyncio.get_running_loop().create_future()
|
||
|
||
async with serve(handler, host, port):
|
||
await stop
|
||
|
||
Alternatively, call :meth:`~Server.serve_forever` to serve requests and
|
||
cancel it to stop the server::
|
||
|
||
server = await serve(handler, host, port)
|
||
await server.serve_forever()
|
||
|
||
Args:
|
||
handler: Connection handler. It receives the WebSocket connection,
|
||
which is a :class:`ServerConnection`, in argument.
|
||
host: Network interfaces the server binds to.
|
||
See :meth:`~asyncio.loop.create_server` for details.
|
||
port: TCP port the server listens on.
|
||
See :meth:`~asyncio.loop.create_server` for details.
|
||
origins: Acceptable values of the ``Origin`` header, for defending
|
||
against Cross-Site WebSocket Hijacking attacks. Include :obj:`None`
|
||
in the list if the lack of an origin is acceptable.
|
||
extensions: List of supported extensions, in order in which they
|
||
should be negotiated and run.
|
||
subprotocols: List of supported subprotocols, in order of decreasing
|
||
preference.
|
||
select_subprotocol: Callback for selecting a subprotocol among
|
||
those supported by the client and the server. It receives a
|
||
:class:`ServerConnection` (not a
|
||
:class:`~websockets.server.ServerProtocol`!) instance and a list of
|
||
subprotocols offered by the client. Other than the first argument,
|
||
it has the same behavior as the
|
||
:meth:`ServerProtocol.select_subprotocol
|
||
<websockets.server.ServerProtocol.select_subprotocol>` method.
|
||
process_request: Intercept the request during the opening handshake.
|
||
Return an HTTP response to force the response or :obj:`None` to
|
||
continue normally. When you force an HTTP 101 Continue response, the
|
||
handshake is successful. Else, the connection is aborted.
|
||
``process_request`` may be a function or a coroutine.
|
||
process_response: Intercept the response during the opening handshake.
|
||
Return an HTTP response to force the response or :obj:`None` to
|
||
continue normally. When you force an HTTP 101 Continue response, the
|
||
handshake is successful. Else, the connection is aborted.
|
||
``process_response`` may be a function or a coroutine.
|
||
server_header: Value of the ``Server`` response header.
|
||
It defaults to ``"Python/x.y.z websockets/X.Y"``. Setting it to
|
||
:obj:`None` removes the header.
|
||
compression: The "permessage-deflate" extension is enabled by default.
|
||
Set ``compression`` to :obj:`None` to disable it. See the
|
||
:doc:`compression guide <../../topics/compression>` for details.
|
||
open_timeout: Timeout for opening connections in seconds.
|
||
:obj:`None` disables the timeout.
|
||
ping_interval: Interval between keepalive pings in seconds.
|
||
:obj:`None` disables keepalive.
|
||
ping_timeout: Timeout for keepalive pings in seconds.
|
||
:obj:`None` disables timeouts.
|
||
close_timeout: Timeout for closing connections in seconds.
|
||
:obj:`None` disables the timeout.
|
||
max_size: Maximum size of incoming messages in bytes.
|
||
:obj:`None` disables the limit.
|
||
max_queue: High-water mark of the buffer where frames are received.
|
||
It defaults to 16 frames. The low-water mark defaults to ``max_queue
|
||
// 4``. You may pass a ``(high, low)`` tuple to set the high-water
|
||
and low-water marks. If you want to disable flow control entirely,
|
||
you may set it to ``None``, although that's a bad idea.
|
||
write_limit: High-water mark of write buffer in bytes. It is passed to
|
||
:meth:`~asyncio.WriteTransport.set_write_buffer_limits`. It defaults
|
||
to 32 KiB. You may pass a ``(high, low)`` tuple to set the
|
||
high-water and low-water marks.
|
||
logger: Logger for this server.
|
||
It defaults to ``logging.getLogger("websockets.server")``. See the
|
||
:doc:`logging guide <../../topics/logging>` for details.
|
||
create_connection: Factory for the :class:`ServerConnection` managing
|
||
the connection. Set it to a wrapper or a subclass to customize
|
||
connection handling.
|
||
|
||
Any other keyword arguments are passed to the event loop's
|
||
:meth:`~asyncio.loop.create_server` method.
|
||
|
||
For example:
|
||
|
||
* You can set ``ssl`` to a :class:`~ssl.SSLContext` to enable TLS.
|
||
|
||
* You can set ``sock`` to provide a preexisting TCP socket. You may call
|
||
:func:`socket.create_server` (not to be confused with the event loop's
|
||
:meth:`~asyncio.loop.create_server` method) to create a suitable server
|
||
socket and customize it.
|
||
|
||
* You can set ``start_serving`` to ``False`` to start accepting connections
|
||
only after you call :meth:`~Server.start_serving()` or
|
||
:meth:`~Server.serve_forever()`.
|
||
|
||
"""
|
||
|
||
def __init__(
|
||
self,
|
||
handler: Callable[[ServerConnection], Awaitable[None]],
|
||
host: str | None = None,
|
||
port: int | None = None,
|
||
*,
|
||
# WebSocket
|
||
origins: Sequence[Origin | None] | None = None,
|
||
extensions: Sequence[ServerExtensionFactory] | None = None,
|
||
subprotocols: Sequence[Subprotocol] | None = None,
|
||
select_subprotocol: (
|
||
Callable[
|
||
[ServerConnection, Sequence[Subprotocol]],
|
||
Subprotocol | None,
|
||
]
|
||
| None
|
||
) = None,
|
||
process_request: (
|
||
Callable[
|
||
[ServerConnection, Request],
|
||
Awaitable[Response | None] | Response | None,
|
||
]
|
||
| None
|
||
) = None,
|
||
process_response: (
|
||
Callable[
|
||
[ServerConnection, Request, Response],
|
||
Awaitable[Response | None] | Response | None,
|
||
]
|
||
| None
|
||
) = None,
|
||
server_header: str | None = SERVER,
|
||
compression: str | None = "deflate",
|
||
# Timeouts
|
||
open_timeout: float | None = 10,
|
||
ping_interval: float | None = 20,
|
||
ping_timeout: float | None = 20,
|
||
close_timeout: float | None = 10,
|
||
# Limits
|
||
max_size: int | None = 2**20,
|
||
max_queue: int | None | tuple[int | None, int | None] = 16,
|
||
write_limit: int | tuple[int, int | None] = 2**15,
|
||
# Logging
|
||
logger: LoggerLike | None = None,
|
||
# Escape hatch for advanced customization
|
||
create_connection: type[ServerConnection] | None = None,
|
||
# Other keyword arguments are passed to loop.create_server
|
||
**kwargs: Any,
|
||
) -> None:
|
||
if subprotocols is not None:
|
||
validate_subprotocols(subprotocols)
|
||
|
||
if compression == "deflate":
|
||
extensions = enable_server_permessage_deflate(extensions)
|
||
elif compression is not None:
|
||
raise ValueError(f"unsupported compression: {compression}")
|
||
|
||
if create_connection is None:
|
||
create_connection = ServerConnection
|
||
|
||
self.server = Server(
|
||
handler,
|
||
process_request=process_request,
|
||
process_response=process_response,
|
||
server_header=server_header,
|
||
open_timeout=open_timeout,
|
||
logger=logger,
|
||
)
|
||
|
||
if kwargs.get("ssl") is not None:
|
||
kwargs.setdefault("ssl_handshake_timeout", open_timeout)
|
||
if sys.version_info[:2] >= (3, 11): # pragma: no branch
|
||
kwargs.setdefault("ssl_shutdown_timeout", close_timeout)
|
||
|
||
def factory() -> ServerConnection:
|
||
"""
|
||
Create an asyncio protocol for managing a WebSocket connection.
|
||
|
||
"""
|
||
# Create a closure to give select_subprotocol access to connection.
|
||
protocol_select_subprotocol: (
|
||
Callable[
|
||
[ServerProtocol, Sequence[Subprotocol]],
|
||
Subprotocol | None,
|
||
]
|
||
| None
|
||
) = None
|
||
if select_subprotocol is not None:
|
||
|
||
def protocol_select_subprotocol(
|
||
protocol: ServerProtocol,
|
||
subprotocols: Sequence[Subprotocol],
|
||
) -> Subprotocol | None:
|
||
# mypy doesn't know that select_subprotocol is immutable.
|
||
assert select_subprotocol is not None
|
||
# Ensure this function is only used in the intended context.
|
||
assert protocol is connection.protocol
|
||
return select_subprotocol(connection, subprotocols)
|
||
|
||
# This is a protocol in the Sans-I/O implementation of websockets.
|
||
protocol = ServerProtocol(
|
||
origins=origins,
|
||
extensions=extensions,
|
||
subprotocols=subprotocols,
|
||
select_subprotocol=protocol_select_subprotocol,
|
||
max_size=max_size,
|
||
logger=logger,
|
||
)
|
||
# This is a connection in websockets and a protocol in asyncio.
|
||
connection = create_connection(
|
||
protocol,
|
||
self.server,
|
||
ping_interval=ping_interval,
|
||
ping_timeout=ping_timeout,
|
||
close_timeout=close_timeout,
|
||
max_queue=max_queue,
|
||
write_limit=write_limit,
|
||
)
|
||
return connection
|
||
|
||
loop = asyncio.get_running_loop()
|
||
if kwargs.pop("unix", False):
|
||
self.create_server = loop.create_unix_server(factory, **kwargs)
|
||
else:
|
||
# mypy cannot tell that kwargs must provide sock when port is None.
|
||
self.create_server = loop.create_server(factory, host, port, **kwargs) # type: ignore[arg-type]
|
||
|
||
# async with serve(...) as ...: ...
|
||
|
||
async def __aenter__(self) -> Server:
|
||
return await self
|
||
|
||
async def __aexit__(
|
||
self,
|
||
exc_type: type[BaseException] | None,
|
||
exc_value: BaseException | None,
|
||
traceback: TracebackType | None,
|
||
) -> None:
|
||
self.server.close()
|
||
await self.server.wait_closed()
|
||
|
||
# ... = await serve(...)
|
||
|
||
def __await__(self) -> Generator[Any, None, Server]:
|
||
# Create a suitable iterator by calling __await__ on a coroutine.
|
||
return self.__await_impl__().__await__()
|
||
|
||
async def __await_impl__(self) -> Server:
|
||
server = await self.create_server
|
||
self.server.wrap(server)
|
||
return self.server
|
||
|
||
# ... = yield from serve(...) - remove when dropping Python < 3.10
|
||
|
||
__iter__ = __await__
|
||
|
||
|
||
def unix_serve(
|
||
handler: Callable[[ServerConnection], Awaitable[None]],
|
||
path: str | None = None,
|
||
**kwargs: Any,
|
||
) -> Awaitable[Server]:
|
||
"""
|
||
Create a WebSocket server listening on a Unix socket.
|
||
|
||
This function is identical to :func:`serve`, except the ``host`` and
|
||
``port`` arguments are replaced by ``path``. It's only available on Unix.
|
||
|
||
It's useful for deploying a server behind a reverse proxy such as nginx.
|
||
|
||
Args:
|
||
handler: Connection handler. It receives the WebSocket connection,
|
||
which is a :class:`ServerConnection`, in argument.
|
||
path: File system path to the Unix socket.
|
||
|
||
"""
|
||
return serve(handler, unix=True, path=path, **kwargs)
|
||
|
||
|
||
def is_credentials(credentials: Any) -> bool:
|
||
try:
|
||
username, password = credentials
|
||
except (TypeError, ValueError):
|
||
return False
|
||
else:
|
||
return isinstance(username, str) and isinstance(password, str)
|
||
|
||
|
||
def basic_auth(
|
||
realm: str = "",
|
||
credentials: tuple[str, str] | Iterable[tuple[str, str]] | None = None,
|
||
check_credentials: Callable[[str, str], Awaitable[bool] | bool] | None = None,
|
||
) -> Callable[[ServerConnection, Request], Awaitable[Response | None]]:
|
||
"""
|
||
Factory for ``process_request`` to enforce HTTP Basic Authentication.
|
||
|
||
:func:`basic_auth` is designed to integrate with :func:`serve` as follows::
|
||
|
||
from websockets.asyncio.server import basic_auth, serve
|
||
|
||
async with serve(
|
||
...,
|
||
process_request=basic_auth(
|
||
realm="my dev server",
|
||
credentials=("hello", "iloveyou"),
|
||
),
|
||
):
|
||
|
||
If authentication succeeds, the connection's ``username`` attribute is set.
|
||
If it fails, the server responds with an HTTP 401 Unauthorized status.
|
||
|
||
One of ``credentials`` or ``check_credentials`` must be provided; not both.
|
||
|
||
Args:
|
||
realm: Scope of protection. It should contain only ASCII characters
|
||
because the encoding of non-ASCII characters is undefined. Refer to
|
||
section 2.2 of :rfc:`7235` for details.
|
||
credentials: Hard coded authorized credentials. It can be a
|
||
``(username, password)`` pair or a list of such pairs.
|
||
check_credentials: Function or coroutine that verifies credentials.
|
||
It receives ``username`` and ``password`` arguments and returns
|
||
whether they're valid.
|
||
Raises:
|
||
TypeError: If ``credentials`` or ``check_credentials`` is wrong.
|
||
ValueError: If ``credentials`` and ``check_credentials`` are both
|
||
provided or both not provided.
|
||
|
||
"""
|
||
if (credentials is None) == (check_credentials is None):
|
||
raise ValueError("provide either credentials or check_credentials")
|
||
|
||
if credentials is not None:
|
||
if is_credentials(credentials):
|
||
credentials_list = [cast(tuple[str, str], credentials)]
|
||
elif isinstance(credentials, Iterable):
|
||
credentials_list = list(cast(Iterable[tuple[str, str]], credentials))
|
||
if not all(is_credentials(item) for item in credentials_list):
|
||
raise TypeError(f"invalid credentials argument: {credentials}")
|
||
else:
|
||
raise TypeError(f"invalid credentials argument: {credentials}")
|
||
|
||
credentials_dict = dict(credentials_list)
|
||
|
||
def check_credentials(username: str, password: str) -> bool:
|
||
try:
|
||
expected_password = credentials_dict[username]
|
||
except KeyError:
|
||
return False
|
||
return hmac.compare_digest(expected_password, password)
|
||
|
||
assert check_credentials is not None # help mypy
|
||
|
||
async def process_request(
|
||
connection: ServerConnection,
|
||
request: Request,
|
||
) -> Response | None:
|
||
"""
|
||
Perform HTTP Basic Authentication.
|
||
|
||
If it succeeds, set the connection's ``username`` attribute and return
|
||
:obj:`None`. If it fails, return an HTTP 401 Unauthorized responss.
|
||
|
||
"""
|
||
try:
|
||
authorization = request.headers["Authorization"]
|
||
except KeyError:
|
||
response = connection.respond(
|
||
http.HTTPStatus.UNAUTHORIZED,
|
||
"Missing credentials\n",
|
||
)
|
||
response.headers["WWW-Authenticate"] = build_www_authenticate_basic(realm)
|
||
return response
|
||
|
||
try:
|
||
username, password = parse_authorization_basic(authorization)
|
||
except InvalidHeader:
|
||
response = connection.respond(
|
||
http.HTTPStatus.UNAUTHORIZED,
|
||
"Unsupported credentials\n",
|
||
)
|
||
response.headers["WWW-Authenticate"] = build_www_authenticate_basic(realm)
|
||
return response
|
||
|
||
valid_credentials = check_credentials(username, password)
|
||
if isinstance(valid_credentials, Awaitable):
|
||
valid_credentials = await valid_credentials
|
||
|
||
if not valid_credentials:
|
||
response = connection.respond(
|
||
http.HTTPStatus.UNAUTHORIZED,
|
||
"Invalid credentials\n",
|
||
)
|
||
response.headers["WWW-Authenticate"] = build_www_authenticate_basic(realm)
|
||
return response
|
||
|
||
connection.username = username
|
||
return None
|
||
|
||
return process_request
|