801 lines
30 KiB
Python
801 lines
30 KiB
Python
from __future__ import annotations
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import logging
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import os
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import ssl as ssl_module
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import traceback
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import urllib.parse
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from collections.abc import AsyncIterator, Generator, Sequence
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from types import TracebackType
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from typing import Any, Callable, Literal
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import trio
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from ..client import ClientProtocol, backoff, process_exception
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from ..datastructures import Headers, HeadersLike
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from ..exceptions import (
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InvalidProxyMessage,
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InvalidProxyStatus,
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InvalidStatus,
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ProxyError,
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SecurityError,
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)
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from ..extensions.base import ClientExtensionFactory
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from ..extensions.permessage_deflate import enable_client_permessage_deflate
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from ..headers import validate_subprotocols
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from ..http11 import USER_AGENT, Response
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from ..protocol import CONNECTING, Event
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from ..proxy import Proxy, get_proxy, parse_proxy, prepare_connect_request
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from ..streams import StreamReader
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from ..typing import LoggerLike, Origin, PathLike, Subprotocol
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from ..uri import WebSocketURI, parse_uri
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from .connection import Connection
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from .utils import race_events
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__all__ = ["connect", "unix_connect", "ClientConnection"]
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MAX_REDIRECTS = int(os.environ.get("WEBSOCKETS_MAX_REDIRECTS", "10"))
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class ClientConnection(Connection):
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"""
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:mod:`trio` implementation of a WebSocket client connection.
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:class:`ClientConnection` provides :meth:`recv` and :meth:`send` coroutines
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for 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``, and
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``max_queue`` arguments have the same meaning as in :func:`connect`.
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Args:
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nursery: Trio nursery.
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stream: Trio stream connected to a WebSocket server.
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protocol: Sans-I/O connection.
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"""
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def __init__(
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self,
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nursery: trio.Nursery,
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stream: trio.abc.Stream,
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protocol: ClientProtocol,
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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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) -> None:
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self.protocol: ClientProtocol
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super().__init__(
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nursery,
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stream,
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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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)
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self.response_rcvd = trio.Event()
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async def handshake(
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self,
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additional_headers: HeadersLike | None = None,
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user_agent_header: str | None = USER_AGENT,
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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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self.request = self.protocol.connect()
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if additional_headers is not None:
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self.request.headers.update(additional_headers)
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if user_agent_header is not None:
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self.request.headers.setdefault("User-Agent", user_agent_header)
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async with self.send_context(expected_state=CONNECTING):
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self.protocol.send_request(self.request)
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await race_events(self.response_rcvd, self.stream_closed)
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# self.protocol.handshake_exc is set when the connection is lost before
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# receiving a response, when the response cannot be parsed, or when the
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# response fails 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 response.
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if self.response is None:
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assert isinstance(event, Response)
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self.response = event
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self.response_rcvd.set()
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# Later events - frames.
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else:
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super().process_event(event)
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# This is spelled in lower case because it's exposed as a callable in the API.
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class connect:
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"""
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Connect to the WebSocket server at ``uri``.
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:func:`connect` should be treated as an asynchronous context manager
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yielding a :class:`ClientConnection`, which can then receive and send
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messages::
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from websockets.trio.client import connect
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async with connect(...) as websocket:
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...
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The connection is closed automatically when exiting the context.
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:func:`connect` can also be treated as an infinite asynchronous iterator
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to reconnect automatically on errors::
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async for websocket in connect(...):
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try:
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...
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except websockets.exceptions.ConnectionClosed:
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continue
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If the connection fails with a transient error, it is retried with
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exponential backoff. If it fails with a fatal error, the exception is
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raised, breaking out of the loop.
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The connection is closed automatically after each iteration of the loop.
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:func:`connect` cannot be awaited directly. This is because it runs a task
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to manage the connection and Trio doesn't support spawning tasks without a
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context that ensures completion.
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Args:
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uri: URI of the WebSocket server.
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stream: Preexisting TCP stream. ``stream`` overrides the host and port
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from ``uri``. You may call :func:`~trio.open_tcp_stream` to create a
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suitable TCP stream.
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ssl: Configuration for enabling TLS on the connection.
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server_hostname: Host name for the TLS handshake. ``server_hostname``
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overrides the host name from ``uri``.
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origin: Value of the ``Origin`` header, for servers that require it.
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extensions: List of supported extensions, in order in which they
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should be negotiated and run.
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subprotocols: List of supported subprotocols, in order of decreasing
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preference.
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compression: The "permessage-deflate" extension is enabled by default.
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Set ``compression`` to :obj:`None` to disable it. See the
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:doc:`compression guide <../../topics/compression>` for details.
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additional_headers: Arbitrary HTTP headers to add to the handshake
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request.
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user_agent_header: Value of the ``User-Agent`` request header.
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It defaults to ``"Python/x.y.z websockets/X.Y"``.
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Setting it to :obj:`None` removes the header.
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proxy: If a proxy is configured, it is used by default. Set ``proxy``
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to :obj:`None` to disable the proxy or to the address of a proxy
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to override the system configuration. See the :doc:`proxy docs
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<../../topics/proxies>` for details.
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proxy_ssl: Configuration for enabling TLS on the proxy connection.
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proxy_server_hostname: Host name for the TLS handshake with the proxy.
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``proxy_server_hostname`` overrides the host name from ``proxy``.
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process_exception: When reconnecting automatically, tell whether an
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error is transient or fatal. The default behavior is defined by
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:func:`~websockets.client.process_exception`. Refer to its
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documentation for details.
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open_timeout: Timeout for opening the connection in seconds.
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:obj:`None` disables the timeout.
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ping_interval: Interval between keepalive pings in seconds.
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:obj:`None` disables keepalive.
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ping_timeout: Timeout for keepalive pings in seconds.
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:obj:`None` disables timeouts.
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close_timeout: Timeout for closing the connection in seconds.
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:obj:`None` disables the timeout.
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reconnect_delays: Delays in seconds between reconnection attempts.
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Default is exponential backoff with 5s jitter, capped at 60s.
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max_size: Maximum size of incoming messages in bytes.
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:obj:`None` disables the limit. You may pass a ``(max_message_size,
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max_fragment_size)`` tuple to set different limits for messages and
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fragments when you expect long messages sent in short fragments.
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max_queue: High-water mark of the buffer where frames are received.
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It defaults to 16 frames. The low-water mark defaults to ``max_queue
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// 4``. You may pass a ``(high, low)`` tuple to set the high-water
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and low-water marks. If you want to disable flow control entirely,
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you may set it to ``None``, although that's a bad idea.
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logger: Logger for this client.
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It defaults to ``logging.getLogger("websockets.client")``.
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See the :doc:`logging guide <../../topics/logging>` for details.
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create_connection: Factory for the :class:`ClientConnection` managing
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the connection. Set it to a wrapper or a subclass to customize
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connection handling.
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Any other keyword arguments are passed to :func:`~trio.open_tcp_stream`.
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For example, you can set ``host`` and ``port`` to connect to a different
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host and port from those found in ``uri``. This only changes the destination
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of the TCP connection. The host name from ``uri`` is still used in the TLS
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handshake for secure connections and in the ``Host`` header.
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Raises:
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InvalidURI: If ``uri`` isn't a valid WebSocket URI.
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InvalidProxy: If ``proxy`` isn't a valid proxy.
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OSError: If the TCP connection fails.
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InvalidHandshake: If the opening handshake fails.
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TimeoutError: If the opening handshake times out.
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"""
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# Arguments of type SSLContext don't render correctly in the documentation
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# because of https://github.com/sphinx-doc/sphinx/issues/13838.
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def __init__(
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self,
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uri: str,
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*,
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# TCP/TLS
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stream: trio.abc.Stream | None = None,
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ssl: ssl_module.SSLContext | None = None,
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server_hostname: str | None = None,
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# WebSocket
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origin: Origin | None = None,
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extensions: Sequence[ClientExtensionFactory] | None = None,
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subprotocols: Sequence[Subprotocol] | None = None,
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compression: str | None = "deflate",
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# HTTP
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additional_headers: HeadersLike | None = None,
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user_agent_header: str | None = USER_AGENT,
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proxy: str | Literal[True] | None = True,
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proxy_ssl: ssl_module.SSLContext | None = None,
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proxy_server_hostname: str | None = None,
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process_exception: Callable[[Exception], Exception | None] = process_exception,
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# Timeouts
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open_timeout: float | None = 10,
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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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reconnect_delays: Callable[[], Generator[float]] = backoff,
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# Limits
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max_size: int | None | tuple[int | None, int | None] = 2**20,
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max_queue: int | None | tuple[int | None, int | None] = 16,
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# Logging
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logger: LoggerLike | None = None,
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# Escape hatch for advanced customization
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create_connection: type[ClientConnection] | None = None,
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# Other keyword arguments are passed to trio.open_tcp_stream
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**kwargs: Any,
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) -> None:
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self.uri = uri
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self.ws_uri = parse_uri(uri)
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if not self.ws_uri.secure and ssl is not None:
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raise ValueError("ssl argument is incompatible with a ws:// URI")
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if subprotocols is not None:
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validate_subprotocols(subprotocols)
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if compression == "deflate":
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extensions = enable_client_permessage_deflate(extensions)
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elif compression is not None:
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raise ValueError(f"unsupported compression: {compression}")
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if logger is None:
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logger = logging.getLogger("websockets.client")
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if create_connection is None:
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create_connection = ClientConnection
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self.stream = stream
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self.ssl = ssl
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self.server_hostname = server_hostname
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self.additional_headers = additional_headers
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self.user_agent_header = user_agent_header
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self.proxy = proxy
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self.proxy_ssl = proxy_ssl
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self.proxy_server_hostname = proxy_server_hostname
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self.process_exception = process_exception
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self.open_timeout = open_timeout
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self.reconnect_delays = reconnect_delays
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self.logger = logger
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self.create_connection = create_connection
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self.open_tcp_stream_kwargs = kwargs
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self.protocol_kwargs = dict(
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origin=origin,
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extensions=extensions,
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subprotocols=subprotocols,
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max_size=max_size,
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logger=logger,
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)
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self.connection_kwargs = dict(
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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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)
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async def open_tcp_stream(self) -> trio.abc.Stream:
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"""Open a TCP or Unix connection to the server, possibly through a proxy."""
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kwargs = self.open_tcp_stream_kwargs.copy()
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unix = kwargs.pop("unix", False)
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proxy = self.proxy
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if unix:
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proxy = None
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if proxy is True:
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proxy = get_proxy(self.ws_uri)
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if unix:
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return await trio.open_unix_socket(kwargs.pop("path"))
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elif proxy is not None:
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proxy_parsed = parse_proxy(proxy)
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if proxy_parsed.scheme[:5] == "socks":
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return await connect_socks_proxy(
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proxy_parsed,
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self.ws_uri,
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# websockets is consistent with trio while python_socks is
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# consistent across implementations.
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local_addr=kwargs.pop("local_address", None),
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)
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elif proxy_parsed.scheme[:4] == "http":
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if proxy_parsed.scheme != "https" and self.proxy_ssl is not None:
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raise ValueError(
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"proxy_ssl argument is incompatible with an http:// proxy"
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)
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return await connect_http_proxy(
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proxy_parsed,
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self.ws_uri,
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user_agent_header=self.user_agent_header,
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ssl=self.proxy_ssl,
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server_hostname=self.proxy_server_hostname,
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**kwargs,
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)
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else:
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raise AssertionError("parse_proxy returned unsupported proxy")
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else: # proxy is None
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kwargs.setdefault("host", self.ws_uri.host)
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kwargs.setdefault("port", self.ws_uri.port)
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return await trio.open_tcp_stream(**kwargs)
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async def enable_tls(self, stream: trio.abc.Stream) -> trio.abc.Stream:
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"""Enable TLS on the connection."""
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if self.ssl is None:
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ssl = ssl_module.create_default_context()
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else:
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ssl = self.ssl
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if self.server_hostname is None:
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server_hostname = self.ws_uri.host
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else:
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server_hostname = self.server_hostname
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ssl_stream = trio.SSLStream(
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stream,
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ssl,
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server_hostname=server_hostname,
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https_compatible=True,
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)
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await ssl_stream.do_handshake()
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return ssl_stream
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async def open_connection(self, nursery: trio.Nursery) -> ClientConnection:
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"""Create a WebSocket connection."""
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if self.stream is None:
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stream = await self.open_tcp_stream()
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else:
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stream = self.stream
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try:
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if self.ws_uri.secure:
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stream = await self.enable_tls(stream)
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protocol = ClientProtocol(
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self.ws_uri,
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**self.protocol_kwargs, # type: ignore
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)
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# self.create_connection defaults to ClientConnection.
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connection = self.create_connection(
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nursery,
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stream,
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protocol,
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**self.connection_kwargs, # type: ignore
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)
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await connection.handshake(
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self.additional_headers,
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self.user_agent_header,
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)
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except trio.Cancelled:
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await trio.aclose_forcefully(stream)
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# The nursery running this coroutine was canceled.
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# The next checkpoint raises trio.Cancelled.
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# aclose_forcefully() never returns.
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raise AssertionError("nursery should be canceled")
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except Exception:
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# Always close the connection even though keep-alive is the default
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# in HTTP/1.1 because the current implementation ties opening the
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# TCP/TLS connection with initializing the WebSocket protocol.
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await trio.aclose_forcefully(stream)
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raise
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return connection
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def process_redirect(self, exc: Exception) -> Exception | str:
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"""
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Determine whether a connection error is a redirect that can be followed.
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Return the new URI if it's a valid redirect. Else, return an exception.
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"""
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if not (
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isinstance(exc, InvalidStatus)
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and exc.response.status_code
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in [
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300, # Multiple Choices
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301, # Moved Permanently
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302, # Found
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303, # See Other
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307, # Temporary Redirect
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308, # Permanent Redirect
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]
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and "Location" in exc.response.headers
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):
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return exc
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old_ws_uri = self.ws_uri
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new_uri = urllib.parse.urljoin(self.uri, exc.response.headers["Location"])
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new_ws_uri = parse_uri(new_uri)
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# If connect() received a stream, it is closed and cannot be reused.
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if self.stream is not None:
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return ValueError(
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f"cannot follow redirect to {new_uri} with a preexisting stream"
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)
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# TLS downgrade is forbidden.
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if old_ws_uri.secure and not new_ws_uri.secure:
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return SecurityError(f"cannot follow redirect to non-secure URI {new_uri}")
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# Apply restrictions to cross-origin redirects.
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if (
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old_ws_uri.secure != new_ws_uri.secure
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or old_ws_uri.host != new_ws_uri.host
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or old_ws_uri.port != new_ws_uri.port
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):
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# Cross-origin redirects on Unix sockets don't quite make sense.
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if self.open_tcp_stream_kwargs.get("unix", False):
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return ValueError(
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f"cannot follow cross-origin redirect to {new_uri} "
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f"with a Unix socket"
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)
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# Cross-origin redirects when host and port are overridden are ill-defined.
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if (
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self.open_tcp_stream_kwargs.get("host") is not None
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or self.open_tcp_stream_kwargs.get("port") is not None
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):
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return ValueError(
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f"cannot follow cross-origin redirect to {new_uri} "
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f"with an explicit host or port"
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)
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# Strip credentials to avoid leaking them to a different origin.
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if self.additional_headers is not None:
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self.additional_headers = Headers(
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(
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(key, value)
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for key, value in Headers(self.additional_headers).raw_items()
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if key.lower()
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not in ["authorization", "cookie", "proxy-authorization"]
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)
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)
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return new_uri
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async def connect(self, nursery: trio.Nursery) -> ClientConnection:
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try:
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with (
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trio.CancelScope()
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if self.open_timeout is None
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else trio.fail_after(self.open_timeout)
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):
|
|
for _ in range(MAX_REDIRECTS):
|
|
try:
|
|
connection = await self.open_connection(nursery)
|
|
except Exception as exc:
|
|
exc_or_uri = self.process_redirect(exc)
|
|
if isinstance(exc_or_uri, Exception):
|
|
# Response isn't a valid redirect; raise the exception.
|
|
if exc_or_uri is exc:
|
|
raise
|
|
else:
|
|
raise exc_or_uri from exc
|
|
else:
|
|
# Response is a valid redirect; follow it.
|
|
self.uri = exc_or_uri
|
|
self.ws_uri = parse_uri(exc_or_uri)
|
|
continue
|
|
|
|
else:
|
|
connection.start_keepalive()
|
|
return connection
|
|
else:
|
|
raise SecurityError(f"more than {MAX_REDIRECTS} redirects")
|
|
|
|
except trio.TooSlowError as exc:
|
|
# Re-raise exception with an informative error message.
|
|
raise TimeoutError("timed out during opening handshake") from exc
|
|
|
|
# Do not define __await__ for ... = await nursery.start(connect, ...)
|
|
# because it doesn't look idiomatic in Trio.
|
|
|
|
# async with connect(...) as ...: ...
|
|
|
|
async def __aenter__(self) -> ClientConnection:
|
|
await self.__aenter_nursery__()
|
|
try:
|
|
self.connection = await self.connect(self.nursery)
|
|
return self.connection
|
|
except BaseException as exc:
|
|
await self.__aexit_nursery__(type(exc), exc, exc.__traceback__)
|
|
raise AssertionError("expected __aexit_nursery__ to re-raise the exception")
|
|
|
|
async def __aexit__(
|
|
self,
|
|
exc_type: type[BaseException] | None,
|
|
exc_value: BaseException | None,
|
|
traceback: TracebackType | None,
|
|
) -> None:
|
|
try:
|
|
try:
|
|
await self.connection.aclose()
|
|
finally:
|
|
del self.connection
|
|
finally:
|
|
await self.__aexit_nursery__(exc_type, exc_value, traceback)
|
|
|
|
async def __aenter_nursery__(self) -> None:
|
|
if hasattr(self, "nursery_manager"):
|
|
raise RuntimeError("connect() isn't reentrant")
|
|
self.nursery_manager = trio.open_nursery()
|
|
self.nursery = await self.nursery_manager.__aenter__()
|
|
|
|
async def __aexit_nursery__(
|
|
self,
|
|
exc_type: type[BaseException] | None,
|
|
exc_value: BaseException | None,
|
|
traceback: TracebackType | None,
|
|
) -> None:
|
|
# We need a nursery to start the recv_events and keepalive coroutines.
|
|
# They aren't expected to raise exceptions; instead they catch and log
|
|
# all unexpected errors. To keep the nursery an implementation detail,
|
|
# unwrap exceptions raised by user code — per the second option here:
|
|
# https://trio.readthedocs.io/en/stable/reference-core.html#designing-for-multiple-errors
|
|
try:
|
|
await self.nursery_manager.__aexit__(exc_type, exc_value, traceback)
|
|
except BaseException as exc:
|
|
assert isinstance(exc, BaseExceptionGroup)
|
|
try:
|
|
trio._util.raise_single_exception_from_group(exc)
|
|
except trio._util.MultipleExceptionError:
|
|
raise AssertionError(
|
|
"unexpected multiple exceptions; please file a bug report"
|
|
) from exc
|
|
finally:
|
|
del self.nursery_manager
|
|
|
|
# async for ... in connect(...):
|
|
|
|
async def __aiter__(self) -> AsyncIterator[ClientConnection]:
|
|
delays: Generator[float] | None = None
|
|
while True:
|
|
try:
|
|
async with self as connection:
|
|
yield connection
|
|
except Exception as exc:
|
|
# Determine whether the exception is retryable or fatal.
|
|
# The API of process_exception is "return an exception or None";
|
|
# "raise an exception" is also supported because it's a frequent
|
|
# mistake. It isn't documented in order to keep the API simple.
|
|
try:
|
|
new_exc = self.process_exception(exc)
|
|
except Exception as raised_exc:
|
|
new_exc = raised_exc
|
|
|
|
# The connection failed with a fatal error.
|
|
# Raise the exception and exit the loop.
|
|
if new_exc is exc:
|
|
raise
|
|
if new_exc is not None:
|
|
raise new_exc from exc
|
|
|
|
# The connection failed with a retryable error.
|
|
# Start or continue backoff and reconnect.
|
|
if delays is None:
|
|
delays = self.reconnect_delays()
|
|
delay = next(delays)
|
|
self.logger.info(
|
|
"connect failed; reconnecting in %.1f seconds: %s",
|
|
delay,
|
|
traceback.format_exception_only(exc)[0].strip(),
|
|
)
|
|
await trio.sleep(delay)
|
|
|
|
else:
|
|
# The connection succeeded. Reset backoff.
|
|
delays = None
|
|
|
|
|
|
def unix_connect(
|
|
path: PathLike | None = None,
|
|
uri: str | None = None,
|
|
**kwargs: Any,
|
|
) -> connect:
|
|
"""
|
|
Connect to a WebSocket server listening on a Unix socket.
|
|
|
|
This function accepts the same keyword arguments as :func:`connect`.
|
|
|
|
It's only available on Unix.
|
|
|
|
It's mainly useful for debugging servers listening on Unix sockets.
|
|
|
|
Args:
|
|
path: File system path to the Unix socket.
|
|
uri: URI of the WebSocket server. ``uri`` defaults to
|
|
``ws://localhost/`` or, when a ``ssl`` argument is provided, to
|
|
``wss://localhost/``.
|
|
|
|
"""
|
|
stream = kwargs.get("stream")
|
|
if path is None and stream is None:
|
|
raise ValueError("missing path argument")
|
|
elif path is not None and stream is not None:
|
|
raise ValueError("path is incompatible with stream")
|
|
|
|
if uri is None:
|
|
if kwargs.get("ssl") is None:
|
|
uri = "ws://localhost/"
|
|
else:
|
|
uri = "wss://localhost/"
|
|
|
|
return connect(uri=uri, unix=True, path=path, **kwargs)
|
|
|
|
|
|
try:
|
|
from python_socks import ProxyType
|
|
from python_socks.async_.trio import Proxy as SocksProxy
|
|
|
|
except ImportError:
|
|
|
|
async def connect_socks_proxy(
|
|
proxy: Proxy,
|
|
ws_uri: WebSocketURI,
|
|
**kwargs: Any,
|
|
) -> trio.abc.Stream:
|
|
raise ImportError("connecting through a SOCKS proxy requires python-socks")
|
|
|
|
else:
|
|
SOCKS_PROXY_TYPES = {
|
|
"socks5h": ProxyType.SOCKS5,
|
|
"socks5": ProxyType.SOCKS5,
|
|
"socks4a": ProxyType.SOCKS4,
|
|
"socks4": ProxyType.SOCKS4,
|
|
}
|
|
|
|
SOCKS_PROXY_RDNS = {
|
|
"socks5h": True,
|
|
"socks5": False,
|
|
"socks4a": True,
|
|
"socks4": False,
|
|
}
|
|
|
|
async def connect_socks_proxy(
|
|
proxy: Proxy,
|
|
ws_uri: WebSocketURI,
|
|
**kwargs: Any,
|
|
) -> trio.abc.Stream:
|
|
"""Connect via a SOCKS proxy and return the socket."""
|
|
socks_proxy = SocksProxy(
|
|
SOCKS_PROXY_TYPES[proxy.scheme],
|
|
proxy.host,
|
|
proxy.port,
|
|
proxy.username,
|
|
proxy.password,
|
|
SOCKS_PROXY_RDNS[proxy.scheme],
|
|
)
|
|
# connect() is documented to raise OSError.
|
|
# socks_proxy.connect() re-raises trio.TooSlowError as ProxyTimeoutError.
|
|
# Wrap other exceptions in ProxyError, a subclass of InvalidHandshake.
|
|
try:
|
|
return trio.SocketStream(
|
|
await socks_proxy.connect(ws_uri.host, ws_uri.port, **kwargs)
|
|
)
|
|
except OSError:
|
|
raise
|
|
except Exception as exc:
|
|
raise ProxyError("failed to connect to SOCKS proxy") from exc
|
|
|
|
|
|
async def read_connect_response(stream: trio.abc.Stream) -> Response:
|
|
reader = StreamReader()
|
|
parser = Response.parse(
|
|
reader.read_line,
|
|
reader.read_exact,
|
|
reader.read_to_eof,
|
|
proxy=True,
|
|
)
|
|
try:
|
|
while True:
|
|
data = await stream.receive_some(4096)
|
|
if data:
|
|
reader.feed_data(data)
|
|
else:
|
|
reader.feed_eof()
|
|
next(parser)
|
|
except StopIteration as exc:
|
|
assert isinstance(exc.value, Response) # help mypy
|
|
response = exc.value
|
|
if 200 <= response.status_code < 300:
|
|
return response
|
|
else:
|
|
raise InvalidProxyStatus(response)
|
|
except Exception as exc:
|
|
raise InvalidProxyMessage(
|
|
"did not receive a valid HTTP response from proxy"
|
|
) from exc
|
|
|
|
|
|
async def connect_http_proxy(
|
|
proxy: Proxy,
|
|
ws_uri: WebSocketURI,
|
|
*,
|
|
user_agent_header: str | None = None,
|
|
ssl: ssl_module.SSLContext | None = None,
|
|
server_hostname: str | None = None,
|
|
**kwargs: Any,
|
|
) -> trio.abc.Stream:
|
|
stream: trio.abc.Stream
|
|
stream = await trio.open_tcp_stream(proxy.host, proxy.port, **kwargs)
|
|
|
|
try:
|
|
# Initialize TLS wrapper and perform TLS handshake
|
|
if proxy.scheme == "https":
|
|
if ssl is None:
|
|
ssl = ssl_module.create_default_context()
|
|
if server_hostname is None:
|
|
server_hostname = proxy.host
|
|
ssl_stream = trio.SSLStream(
|
|
stream,
|
|
ssl,
|
|
server_hostname=server_hostname,
|
|
https_compatible=True,
|
|
)
|
|
await ssl_stream.do_handshake()
|
|
stream = ssl_stream
|
|
|
|
# Send CONNECT request to the proxy and read response.
|
|
request = prepare_connect_request(proxy, ws_uri, user_agent_header)
|
|
await stream.send_all(request)
|
|
await read_connect_response(stream)
|
|
|
|
except (trio.Cancelled, Exception):
|
|
await trio.aclose_forcefully(stream)
|
|
raise
|
|
|
|
return stream
|