from __future__ import annotations import logging import os import socket import ssl as ssl_module import threading import time import traceback import urllib.parse import warnings from collections.abc import Generator, Iterator, Sequence from types import TracebackType from typing import Any, Callable, Literal, TypeVar, cast, overload from ..client import ClientProtocol, backoff, process_exception from ..datastructures import Headers, HeadersLike from ..exceptions import ( InvalidProxyMessage, InvalidProxyStatus, InvalidStatus, ProxyError, SecurityError, ) from ..extensions.base import ClientExtensionFactory from ..extensions.permessage_deflate import enable_client_permessage_deflate from ..headers import validate_subprotocols from ..http11 import USER_AGENT, Response from ..protocol import CONNECTING, Event from ..proxy import Proxy, get_proxy, parse_proxy, prepare_connect_request from ..streams import StreamReader from ..typing import BytesLike, LoggerLike, Origin, PathLike, Subprotocol from ..uri import WebSocketURI, parse_uri from .connection import Connection from .utils import Deadline __all__ = ["connect", "unix_connect", "reconnect", "unix_reconnect", "ClientConnection"] MAX_REDIRECTS = int(os.environ.get("WEBSOCKETS_MAX_REDIRECTS", "10")) class ClientConnection(Connection): """ :mod:`threading` implementation of a WebSocket client connection. :class:`ClientConnection` provides :meth:`recv` and :meth:`send` methods for receiving and sending messages. It supports iteration to receive messages:: for message in websocket: process(message) The iterator exits normally when the connection is closed with code 1000 (OK) or 1001 (going away) or without a close code. It raises a :exc:`~websockets.exceptions.ConnectionClosedError` when the connection is closed with any other code. The ``ping_interval``, ``ping_timeout``, ``close_timeout``, and ``max_queue`` arguments have the same meaning as in :func:`connect`. Args: socket: Socket connected to a WebSocket server. protocol: Sans-I/O connection. """ def __init__( self, sock: socket.socket, protocol: ClientProtocol, *, ping_interval: float | None = 20, ping_timeout: float | None = 20, close_timeout: float | None = 10, max_queue: int | None | tuple[int | None, int | None] = 16, ) -> None: self.protocol: ClientProtocol self.response_rcvd = threading.Event() self.pending_legacy_warning = True super().__init__( sock, protocol, ping_interval=ping_interval, ping_timeout=ping_timeout, close_timeout=close_timeout, max_queue=max_queue, ) def __enter__(self) -> ClientConnection: self.pending_legacy_warning = False return super().__enter__() def maybe_raise_legacy_warning(self) -> None: if self.pending_legacy_warning: self.pending_legacy_warning = False warnings.warn( # deprecated in 17.1 "connect() must be used as a context manager: " "with connect(...) as websocket: ...; alternatively, use " "websocket = connect(..., legacy=True) to connect directly", DeprecationWarning, stacklevel=3, ) def handshake( self, additional_headers: HeadersLike | None = None, user_agent_header: str | None = USER_AGENT, timeout: float | None = None, ) -> None: """ Perform the opening handshake. """ self.request = self.protocol.connect() if additional_headers is not None: self.request.headers.update(additional_headers) if user_agent_header is not None: self.request.headers.setdefault("User-Agent", user_agent_header) with self.send_context(expected_state=CONNECTING): self.protocol.send_request(self.request) if not self.response_rcvd.wait(timeout): raise TimeoutError("timed out while waiting for handshake response") # self.protocol.handshake_exc is set when the connection is lost before # receiving a response, when the response cannot be parsed, or when the # response fails the handshake. if self.protocol.handshake_exc is not None: raise self.protocol.handshake_exc def process_event(self, event: Event) -> None: """ Process one incoming event. """ # First event - handshake response. if self.response is None: assert isinstance(event, Response) self.response = event self.response_rcvd.set() # Later events - frames. else: super().process_event(event) def recv_events(self) -> None: """ Read incoming data from the socket and process events. """ try: super().recv_events() finally: # If the connection is closed during the handshake, unblock it. self.response_rcvd.set() class reconnect: """ Similar to :func:`connect`, with support for automatic reconnection. :func:`reconnect` can also be treated as an infinite iterator to reconnect automatically on errors:: for websocket in reconnect(...): try: ... except websockets.exceptions.ConnectionClosed: continue If the connection fails with a transient error, it is retried with exponential backoff. If it fails with a fatal error, the exception is raised, breaking out of the loop. The connection is closed automatically after each iteration of the loop. :func:`reconnect` accepts the same arguments as :func:`connect`, minus the ``legacy`` flag, plus those listed below. It raises the same exceptions. Args: process_exception: When reconnecting automatically, tell whether an error is transient or fatal. The default behavior is defined by :func:`~websockets.client.process_exception`. Refer to its documentation for details. reconnect_delays: Delays in seconds between reconnection attempts. Default is exponential backoff with 5s jitter, capped at 60s. .. admonition:: Why is :func:`reconnect` a separate API from :func:`connect`? :class: tip A new API was necessary to maintain backwards compatibility with this historical behavior of :func:`connect`:: websocket = connect(...) for message in websocket: ... Once the deprecation period elapses, :func:`connect` will be changed to behave like :func:`reconnect` by default. """ def __init__( self, uri: str, *, # TCP/TLS sock: socket.socket | None = None, ssl: ssl_module.SSLContext | None = None, server_hostname: str | None = None, # WebSocket origin: Origin | None = None, extensions: Sequence[ClientExtensionFactory] | None = None, subprotocols: Sequence[Subprotocol] | None = None, compression: str | None = "deflate", # HTTP additional_headers: HeadersLike | None = None, user_agent_header: str | None = USER_AGENT, proxy: str | Literal[True] | None = True, proxy_ssl: ssl_module.SSLContext | None = None, proxy_server_hostname: str | None = None, process_exception: Callable[[Exception], Exception | None] = process_exception, # Timeouts open_timeout: float | None = 10, ping_interval: float | None = 20, ping_timeout: float | None = 20, close_timeout: float | None = 10, reconnect_delays: Callable[[], Generator[float]] = backoff, # Limits max_size: int | None | tuple[int | None, int | None] = 2**20, max_queue: int | None | tuple[int | None, int | None] = 16, # Logging logger: LoggerLike | None = None, # Escape hatch for advanced customization create_connection: type[ClientConnection] | None = None, # Other keyword arguments are passed to socket.create_connection **kwargs: Any, ) -> None: # Backwards compatibility: ssl used to be called ssl_context. if ssl is None and "ssl_context" in kwargs: ssl = kwargs.pop("ssl_context") warnings.warn( # deprecated in 13.0 - 2024-08-20 "ssl_context was renamed to ssl", DeprecationWarning, ) self.uri = uri self.ws_uri = parse_uri(uri) if not self.ws_uri.secure and ssl is not None: raise ValueError("ssl argument is incompatible with a ws:// URI") if subprotocols is not None: validate_subprotocols(subprotocols) if compression == "deflate": extensions = enable_client_permessage_deflate(extensions) elif compression is not None: raise ValueError(f"unsupported compression: {compression}") if logger is None: logger = logging.getLogger("websockets.client") if create_connection is None: create_connection = ClientConnection self.sock = sock self.ssl = ssl self.server_hostname = server_hostname self.additional_headers = additional_headers self.user_agent_header = user_agent_header self.proxy = proxy self.proxy_ssl = proxy_ssl self.proxy_server_hostname = proxy_server_hostname self.process_exception = process_exception self.open_timeout = open_timeout self.reconnect_delays = reconnect_delays self.logger = logger self.create_connection = create_connection self.open_socket_kwargs = kwargs self.protocol_kwargs = dict( origin=origin, extensions=extensions, subprotocols=subprotocols, max_size=max_size, logger=logger, ) self.connection_kwargs = dict( ping_interval=ping_interval, ping_timeout=ping_timeout, close_timeout=close_timeout, max_queue=max_queue, ) def open_socket(self, deadline: Deadline) -> socket.socket: """Open a TCP or Unix connection to the server, possibly through a proxy.""" kwargs = self.open_socket_kwargs.copy() unix = kwargs.pop("unix", False) proxy = self.proxy if unix: proxy = None if proxy is True: proxy = get_proxy(self.ws_uri) if unix: sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) try: sock.settimeout(deadline.timeout()) sock.connect(os.fspath(kwargs.pop("path"))) except Exception: sock.close() raise elif proxy is not None: proxy_parsed = parse_proxy(proxy) if proxy_parsed.scheme[:5] == "socks": sock = connect_socks_proxy( proxy_parsed, self.ws_uri, deadline, # websockets is consistent with the socket module while # python_socks is consistent across implementations. local_addr=kwargs.pop("source_address", None), ) elif proxy_parsed.scheme[:4] == "http": if proxy_parsed.scheme != "https" and self.proxy_ssl is not None: raise ValueError( "proxy_ssl argument is incompatible with an http:// proxy" ) sock = connect_http_proxy( proxy_parsed, self.ws_uri, deadline, user_agent_header=self.user_agent_header, ssl=self.proxy_ssl, server_hostname=self.proxy_server_hostname, **kwargs, ) else: raise AssertionError("parse_proxy returned unsupported proxy") else: # proxy is None kwargs.setdefault("address", (self.ws_uri.host, self.ws_uri.port)) kwargs.setdefault("timeout", deadline.timeout()) sock = socket.create_connection(**kwargs) sock.settimeout(None) return sock def enable_tls(self, sock: socket.socket, deadline: Deadline) -> socket.socket: """Enable TLS on the connection.""" if self.ssl is None: ssl = ssl_module.create_default_context() else: ssl = self.ssl if self.server_hostname is None: server_hostname = self.ws_uri.host else: server_hostname = self.server_hostname sock.settimeout(deadline.timeout()) if self.proxy_ssl is None: sock = ssl.wrap_socket(sock, server_hostname=server_hostname) else: sock_2 = SSLSSLSocket(sock, ssl, server_hostname=server_hostname) # Let's pretend that sock is a socket, even though it isn't. sock = cast(socket.socket, sock_2) sock.settimeout(None) return sock def open_connection(self, deadline: Deadline) -> ClientConnection: """Create a WebSocket connection.""" if self.sock is None: sock = self.open_socket(deadline) else: sock = self.sock try: if sock.family in {socket.AF_INET, socket.AF_INET6}: sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, True) if self.ws_uri.secure: sock = self.enable_tls(sock, deadline) protocol = ClientProtocol( self.ws_uri, **self.protocol_kwargs, # type: ignore ) # self.create_connection defaults to ClientConnection. connection = self.create_connection( sock, protocol, **self.connection_kwargs, # type: ignore ) except Exception: sock.close() raise try: connection.handshake( self.additional_headers, self.user_agent_header, deadline.timeout(), ) except Exception: connection.close_socket() connection.recv_events_thread.join() raise return connection def process_redirect(self, exc: Exception) -> Exception | str: """ Determine whether a connection error is a redirect that can be followed. Return the new URI if it's a valid redirect. Else, return an exception. """ if not ( isinstance(exc, InvalidStatus) and exc.response.status_code in [ 300, # Multiple Choices 301, # Moved Permanently 302, # Found 303, # See Other 307, # Temporary Redirect 308, # Permanent Redirect ] and "Location" in exc.response.headers ): return exc old_ws_uri = self.ws_uri new_uri = urllib.parse.urljoin(self.uri, exc.response.headers["Location"]) new_ws_uri = parse_uri(new_uri) # If connect() received a socket, it is closed and cannot be reused. if self.sock is not None: return ValueError( f"cannot follow redirect to {new_uri} with a preexisting socket" ) # TLS downgrade is forbidden. if old_ws_uri.secure and not new_ws_uri.secure: return SecurityError(f"cannot follow redirect to non-secure URI {new_uri}") # Apply restrictions to cross-origin redirects. if ( old_ws_uri.secure != new_ws_uri.secure or old_ws_uri.host != new_ws_uri.host or old_ws_uri.port != new_ws_uri.port ): # Cross-origin redirects on Unix sockets don't quite make sense. if self.open_socket_kwargs.get("unix", False): return ValueError( f"cannot follow cross-origin redirect to {new_uri} " f"with a Unix socket" ) # Cross-origin redirects when host and port are overridden are ill-defined. if self.open_socket_kwargs.get("address") is not None: return ValueError( f"cannot follow cross-origin redirect to {new_uri} " f"with an explicit host and port" ) # Strip credentials to avoid leaking them to a different origin. if self.additional_headers is not None: self.additional_headers = Headers( ( (key, value) for key, value in Headers(self.additional_headers).raw_items() if key.lower() not in ["authorization", "cookie", "proxy-authorization"] ) ) return new_uri def connect(self) -> ClientConnection: """Connect to a WebSocket server, following redirects.""" # Calculate timeouts on the TCP, TLS, and WebSocket handshakes. # The TCP and TLS timeouts must be set on the socket, then removed # to avoid conflicting with the WebSocket timeout in handshake(). deadline = Deadline(self.open_timeout) for _ in range(MAX_REDIRECTS): try: connection = self.open_connection(deadline) 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") # with connect(...) as ...: ... def __enter__(self) -> ClientConnection: if hasattr(self, "connection"): raise RuntimeError("connect() isn't reentrant") self.connection = self.connect() self.connection.pending_legacy_warning = False return self.connection def __exit__( self, exc_type: type[BaseException] | None, exc_value: BaseException | None, exc_traceback: TracebackType | None, ) -> None: try: self.connection.close() finally: del self.connection # for ... in reconnect(...): ... def __iter__(self) -> Iterator[ClientConnection]: delays: Generator[float] | None = None while True: try: 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(), ) time.sleep(delay) else: # The connection succeeded. Reset backoff. delays = None @overload def connect( uri: str, *, # TCP/TLS sock: socket.socket | None = ..., ssl: ssl_module.SSLContext | None = ..., server_hostname: str | None = ..., # WebSocket origin: Origin | None = ..., extensions: Sequence[ClientExtensionFactory] | None = ..., subprotocols: Sequence[Subprotocol] | None = ..., compression: str | None = ..., # HTTP additional_headers: HeadersLike | None = ..., user_agent_header: str | None = ..., proxy: str | Literal[True] | None = ..., proxy_ssl: ssl_module.SSLContext | None = ..., proxy_server_hostname: str | None = ..., # Timeouts open_timeout: float | None = ..., ping_interval: float | None = ..., ping_timeout: float | None = ..., close_timeout: float | None = ..., # Limits max_size: int | None | tuple[int | None, int | None] = ..., max_queue: int | None | tuple[int | None, int | None] = ..., # Logging logger: LoggerLike | None = ..., # Escape hatch for advanced customization create_connection: type[ClientConnection] | None = ..., # Backwards and forwards compatibility legacy: Literal[True] | None = ..., # Other keyword arguments are passed to socket.create_connection **kwargs: Any, ) -> ClientConnection: ... @overload def connect( uri: str, *, # TCP/TLS sock: socket.socket | None = ..., ssl: ssl_module.SSLContext | None = ..., server_hostname: str | None = ..., # WebSocket origin: Origin | None = ..., extensions: Sequence[ClientExtensionFactory] | None = ..., subprotocols: Sequence[Subprotocol] | None = ..., compression: str | None = ..., # HTTP additional_headers: HeadersLike | None = ..., user_agent_header: str | None = ..., proxy: str | Literal[True] | None = ..., proxy_ssl: ssl_module.SSLContext | None = ..., proxy_server_hostname: str | None = ..., # Timeouts open_timeout: float | None = ..., ping_interval: float | None = ..., ping_timeout: float | None = ..., close_timeout: float | None = ..., # Limits max_size: int | None | tuple[int | None, int | None] = ..., max_queue: int | None | tuple[int | None, int | None] = ..., # Logging logger: LoggerLike | None = ..., # Escape hatch for advanced customization create_connection: type[ClientConnection] | None = ..., # Backwards and forwards compatibility legacy: Literal[False], # Other keyword arguments are passed to socket.create_connection **kwargs: Any, ) -> reconnect: ... def connect( uri: str, *, # TCP/TLS sock: socket.socket | None = None, ssl: ssl_module.SSLContext | None = None, server_hostname: str | None = None, # WebSocket origin: Origin | None = None, extensions: Sequence[ClientExtensionFactory] | None = None, subprotocols: Sequence[Subprotocol] | None = None, compression: str | None = "deflate", # HTTP additional_headers: HeadersLike | None = None, user_agent_header: str | None = USER_AGENT, proxy: str | Literal[True] | None = True, proxy_ssl: ssl_module.SSLContext | None = None, proxy_server_hostname: str | None = None, # 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 | tuple[int | None, int | None] = 2**20, max_queue: int | None | tuple[int | None, int | None] = 16, # Logging logger: LoggerLike | None = None, # Escape hatch for advanced customization create_connection: type[ClientConnection] | None = None, # Backwards and forwards compatibility legacy: bool | None = None, # Other keyword arguments are passed to socket.create_connection **kwargs: Any, ) -> ClientConnection | reconnect: """ Connect to the WebSocket server at ``uri``. :func:`connect` should be treated as a context manager yielding a :class:`ClientConnection`, which can then receive and send messages:: from websockets.sync.client import connect with connect(...) as websocket: ... The connection is closed automatically when exiting the context. Use :func:`reconnect` to reconnect automatically on errors. For backwards compatibility, :func:`connect` can be called directly:: websocket = connect(..., legacy=True) In that case, you're responsible for closing the connection with :meth:`ClientConnection.close` when no longer needed. When the ``legacy`` flag is enabled, :func:`connect` returns directly a :class:`ClientConnection` and iterating that connection yields messages. Currently, this is the default behavior when ``legacy`` isn't specified. When the ``legacy`` flag is explicitly disabled, :func:`connect` behaves like :func:`reconnect`: using it as an iterator returns a new connection at each iteration, making it easy to reconnect automatically on errors. Args: uri: URI of the WebSocket server. sock: Preexisting TCP socket. ``sock`` overrides the host and port from ``uri``. You may call :func:`socket.create_connection` to create a suitable TCP socket. ssl: Configuration for enabling TLS on the connection. server_hostname: Host name for the TLS handshake. ``server_hostname`` overrides the host name from ``uri``. origin: Value of the ``Origin`` header, for servers that require it. 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. 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. additional_headers: Arbitrary HTTP headers to add to the handshake request. user_agent_header: Value of the ``User-Agent`` request header. It defaults to ``"Python/x.y.z websockets/X.Y"``. Setting it to :obj:`None` removes the header. proxy: If a proxy is configured, it is used by default. Set ``proxy`` to :obj:`None` to disable the proxy or to the address of a proxy to override the system configuration. See the :doc:`proxy docs <../../topics/proxies>` for details. proxy_ssl: Configuration for enabling TLS on the proxy connection. proxy_server_hostname: Host name for the TLS handshake with the proxy. ``proxy_server_hostname`` overrides the host name from ``proxy``. open_timeout: Timeout for opening the connection 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 the connection in seconds. :obj:`None` disables the timeout. max_size: Maximum size of incoming messages in bytes. :obj:`None` disables the limit. You may pass a ``(max_message_size, max_fragment_size)`` tuple to set different limits for messages and fragments when you expect long messages sent in short fragments. 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. logger: Logger for this client. It defaults to ``logging.getLogger("websockets.client")``. See the :doc:`logging guide <../../topics/logging>` for details. legacy: Set to :obj:`True` to opt into the historical behavior of returning a :class:`ClientConnection`, without deprecation warning. create_connection: Factory for the :class:`ClientConnection` managing the connection. Set it to a wrapper or a subclass to customize connection handling. Any other keyword arguments are passed to :func:`~socket.create_connection`. For example, you can set ``address`` to a ``(host, port)`` tuple to connect to a different host and port from those found in ``uri``. This only changes the destination of the TCP connection. The host name from ``uri`` is still used in the TLS handshake for secure connections and in the ``Host`` header. Raises: InvalidURI: If ``uri`` isn't a valid WebSocket URI. InvalidProxy: If ``proxy`` isn't a valid proxy. OSError: If the TCP connection fails. InvalidHandshake: If the opening handshake fails. TimeoutError: If the opening handshake times out. """ connecter = reconnect( uri, sock=sock, ssl=ssl, server_hostname=server_hostname, origin=origin, extensions=extensions, subprotocols=subprotocols, compression=compression, additional_headers=additional_headers, user_agent_header=user_agent_header, proxy=proxy, proxy_ssl=proxy_ssl, proxy_server_hostname=proxy_server_hostname, open_timeout=open_timeout, ping_interval=ping_interval, ping_timeout=ping_timeout, close_timeout=close_timeout, max_size=max_size, max_queue=max_queue, logger=logger, create_connection=create_connection, **kwargs, ) # For backwards compatibility, connect defaults to the historical behavior. # For forwards compatibility, the future behavior can be chosen explicitly. if legacy is False: return connecter connection = connecter.connect() # Users can opt in to the historical behavior to remain unaffected when the # future behavior becomes the default. if legacy: connection.pending_legacy_warning = False return connection def unix_reconnect( path: PathLike | None = None, uri: str | None = None, **kwargs: Any, ) -> reconnect: """ Similar to :func:`unix_connect`, with support for automatic reconnection. Refer to the documentation of :func:`reconnect` for details on its behavior. """ sock = kwargs.get("sock") if path is None and sock is None: raise ValueError("missing path argument") elif path is not None and sock is not None: raise ValueError("path is incompatible with sock") if uri is None: # Backwards compatibility: ssl used to be called ssl_context. if kwargs.get("ssl") is None and kwargs.get("ssl_context") is None: uri = "ws://localhost/" else: uri = "wss://localhost/" return reconnect(uri=uri, unix=True, path=path, **kwargs) @overload def unix_connect( path: PathLike | None = ..., uri: str | None = ..., *, legacy: Literal[True] | None = ..., **kwargs: Any, ) -> ClientConnection: ... @overload def unix_connect( path: PathLike | None = ..., uri: str | None = ..., *, legacy: Literal[False], **kwargs: Any, ) -> reconnect: ... def unix_connect( path: PathLike | None = None, uri: str | None = None, *, legacy: bool | None = None, **kwargs: Any, ) -> ClientConnection | reconnect: """ 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`` is provided, to ``wss://localhost/``. """ connecter = unix_reconnect(path, uri, **kwargs) # For backwards compatibility, connect defaults to the historical behavior. # For forwards compatibility, the future behavior can be chosen explicitly. if legacy is False: return connecter connection = connecter.connect() # Users can opt in to the historical behavior to remain unaffected when the # future behavior becomes the default. if legacy: connection.pending_legacy_warning = False return connection try: from python_socks import ProxyType from python_socks.sync import Proxy as SocksProxy except ImportError: def connect_socks_proxy( proxy: Proxy, ws_uri: WebSocketURI, deadline: Deadline, **kwargs: Any, ) -> socket.socket: 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, } def connect_socks_proxy( proxy: Proxy, ws_uri: WebSocketURI, deadline: Deadline, **kwargs: Any, ) -> socket.socket: """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], ) kwargs.setdefault("timeout", deadline.timeout()) # connect() is documented to raise OSError and TimeoutError. # Wrap other exceptions in ProxyError, a subclass of InvalidHandshake. try: return socks_proxy.connect(ws_uri.host, ws_uri.port, **kwargs) except (OSError, TimeoutError, socket.timeout): raise except Exception as exc: raise ProxyError("failed to connect to SOCKS proxy") from exc def read_connect_response(sock: socket.socket, deadline: Deadline) -> Response: reader = StreamReader() parser = Response.parse( reader.read_line, reader.read_exact, reader.read_to_eof, proxy=True, ) try: while True: sock.settimeout(deadline.timeout()) data = sock.recv(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 socket.timeout: raise TimeoutError("timed out while connecting to HTTP proxy") except Exception as exc: raise InvalidProxyMessage( "did not receive a valid HTTP response from proxy" ) from exc finally: sock.settimeout(None) def connect_http_proxy( proxy: Proxy, ws_uri: WebSocketURI, deadline: Deadline, *, user_agent_header: str | None = None, ssl: ssl_module.SSLContext | None = None, server_hostname: str | None = None, **kwargs: Any, ) -> socket.socket: # Connect socket kwargs.setdefault("timeout", deadline.timeout()) sock = socket.create_connection((proxy.host, proxy.port), **kwargs) # 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 sock.settimeout(deadline.timeout()) sock = ssl.wrap_socket(sock, server_hostname=server_hostname) sock.settimeout(None) # Send CONNECT request to the proxy and read response. request = prepare_connect_request(proxy, ws_uri, user_agent_header) sock.sendall(request) try: read_connect_response(sock, deadline) except Exception: sock.close() raise return sock T = TypeVar("T") F = TypeVar("F", bound=Callable[..., T]) class SSLSSLSocket: """ Socket-like object providing TLS-in-TLS. Only methods that are used by websockets are implemented. """ recv_bufsize = 65536 def __init__( self, sock: socket.socket, ssl_context: ssl_module.SSLContext, server_hostname: str | None = None, ) -> None: self.incoming = ssl_module.MemoryBIO() self.outgoing = ssl_module.MemoryBIO() self.ssl_socket = sock self.ssl_object = ssl_context.wrap_bio( self.incoming, self.outgoing, server_hostname=server_hostname, ) self.run_io(self.ssl_object.do_handshake) def run_io(self, func: Callable[..., T], *args: Any) -> T: while True: want_read = False want_write = False try: result = func(*args) except ssl_module.SSLWantReadError: want_read = True except ssl_module.SSLWantWriteError: # pragma: no cover want_write = True # Write outgoing data in all cases. data = self.outgoing.read() if data: self.ssl_socket.sendall(data) # Read incoming data and retry on SSLWantReadError. if want_read: data = self.ssl_socket.recv(self.recv_bufsize) if data: self.incoming.write(data) else: self.incoming.write_eof() continue # Retry after writing outgoing data on SSLWantWriteError. if want_write: # pragma: no cover continue # Return result if no error happened. return result def recv(self, buflen: int) -> bytes: try: return self.run_io(self.ssl_object.read, buflen) except ssl_module.SSLEOFError: return b"" # always ignore ragged EOFs def send(self, data: BytesLike) -> int: return self.run_io(self.ssl_object.write, data) def sendall(self, data: BytesLike) -> None: # adapted from ssl_module.SSLSocket.sendall() count = 0 with memoryview(data) as view, view.cast("B") as byte_view: amount = len(byte_view) while count < amount: count += self.send(byte_view[count:]) # recv_into(), recvfrom(), recvfrom_into(), sendto(), unwrap(), and the # flags argument aren't implemented because websockets doesn't need them. def __getattr__(self, name: str) -> Any: return getattr(self.ssl_socket, name)