add
This commit is contained in:
macbook_max
@@ -0,0 +1,923 @@
|
||||
from __future__ import annotations
|
||||
|
||||
import asyncio
|
||||
import hmac
|
||||
import http
|
||||
import logging
|
||||
import re
|
||||
import socket
|
||||
from collections.abc import Awaitable, Coroutine, Generator, Iterable, Sequence
|
||||
from types import TracebackType
|
||||
from typing import Any, Callable, Mapping, Self, cast
|
||||
|
||||
from ..exceptions import InvalidHeader
|
||||
from ..extensions.base import ServerExtensionFactory
|
||||
from ..extensions.permessage_deflate import enable_server_permessage_deflate
|
||||
from ..frames import CloseCode
|
||||
from ..headers import (
|
||||
build_www_authenticate_basic,
|
||||
parse_authorization_basic,
|
||||
validate_subprotocols,
|
||||
)
|
||||
from ..http11 import SERVER, Request, Response
|
||||
from ..protocol import CONNECTING, OPEN, Event
|
||||
from ..server import ServerProtocol
|
||||
from ..typing import LoggerLike, Origin, PathLike, StatusLike, Subprotocol
|
||||
from ..utils import get_socket_name
|
||||
from .connection import Connection, broadcast
|
||||
|
||||
|
||||
__all__ = [
|
||||
"broadcast",
|
||||
"serve",
|
||||
"unix_serve",
|
||||
"ServerConnection",
|
||||
"Server",
|
||||
"basic_auth",
|
||||
]
|
||||
|
||||
|
||||
class ServerConnection(Connection):
|
||||
"""
|
||||
:mod:`asyncio` implementation of a WebSocket server connection.
|
||||
|
||||
:class:`ServerConnection` provides :meth:`recv` and :meth:`send` methods for
|
||||
receiving and sending messages.
|
||||
|
||||
It supports asynchronous iteration to receive messages::
|
||||
|
||||
async for message in websocket:
|
||||
await 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``, ``max_queue``,
|
||||
and ``write_limit`` arguments have the same meaning as in :func:`serve`.
|
||||
|
||||
Args:
|
||||
protocol: Sans-I/O connection.
|
||||
server: Server that manages this connection.
|
||||
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
protocol: ServerProtocol,
|
||||
server: Server,
|
||||
*,
|
||||
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,
|
||||
write_limit: int | tuple[int, int | None] = 2**15,
|
||||
) -> None:
|
||||
self.protocol: ServerProtocol
|
||||
super().__init__(
|
||||
protocol,
|
||||
ping_interval=ping_interval,
|
||||
ping_timeout=ping_timeout,
|
||||
close_timeout=close_timeout,
|
||||
max_queue=max_queue,
|
||||
write_limit=write_limit,
|
||||
)
|
||||
self.server = server
|
||||
self.request_rcvd: asyncio.Future[None] = self.loop.create_future()
|
||||
self.username: str # see basic_auth()
|
||||
self.handler: Callable[[ServerConnection], Awaitable[None]] # see route()
|
||||
self.handler_kwargs: Mapping[str, Any] # see route()
|
||||
|
||||
def respond(self, status: StatusLike, text: str) -> Response:
|
||||
"""
|
||||
Create a plain text HTTP response.
|
||||
|
||||
``process_request`` and ``process_response`` may call this method to
|
||||
return an HTTP response instead of performing the WebSocket opening
|
||||
handshake.
|
||||
|
||||
You can modify the response before returning it, for example by changing
|
||||
HTTP headers.
|
||||
|
||||
Args:
|
||||
status: HTTP status code.
|
||||
text: HTTP response body; it will be encoded to UTF-8.
|
||||
|
||||
Returns:
|
||||
HTTP response to send to the client.
|
||||
|
||||
"""
|
||||
return self.protocol.reject(status, text)
|
||||
|
||||
async def handshake(
|
||||
self,
|
||||
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,
|
||||
) -> None:
|
||||
"""
|
||||
Perform the opening handshake.
|
||||
|
||||
"""
|
||||
await asyncio.wait(
|
||||
[self.request_rcvd, self.connection_lost_waiter],
|
||||
return_when=asyncio.FIRST_COMPLETED,
|
||||
)
|
||||
|
||||
if self.request is not None:
|
||||
response = None
|
||||
|
||||
if process_request is not None:
|
||||
try:
|
||||
response = process_request(self, self.request)
|
||||
if isinstance(response, Awaitable):
|
||||
response = await response
|
||||
except Exception as exc:
|
||||
self.protocol.handshake_exc = exc
|
||||
self.logger.error("process_request failed", exc_info=True)
|
||||
response = self.protocol.reject(
|
||||
http.HTTPStatus.INTERNAL_SERVER_ERROR,
|
||||
(
|
||||
"Failed to open a WebSocket connection.\n"
|
||||
"See server log for more information.\n"
|
||||
),
|
||||
)
|
||||
|
||||
if response is None:
|
||||
self.response = self.protocol.accept(self.request)
|
||||
else:
|
||||
assert isinstance(response, Response) # help mypy
|
||||
self.response = response
|
||||
|
||||
if server_header is not None:
|
||||
self.response.headers["Server"] = server_header
|
||||
|
||||
response = None
|
||||
|
||||
if process_response is not None:
|
||||
try:
|
||||
response = process_response(self, self.request, self.response)
|
||||
if isinstance(response, Awaitable):
|
||||
response = await response
|
||||
except Exception as exc:
|
||||
self.protocol.handshake_exc = exc
|
||||
self.logger.error("process_response failed", exc_info=True)
|
||||
response = self.protocol.reject(
|
||||
http.HTTPStatus.INTERNAL_SERVER_ERROR,
|
||||
(
|
||||
"Failed to open a WebSocket connection.\n"
|
||||
"See server log for more information.\n"
|
||||
),
|
||||
)
|
||||
|
||||
if response is not None:
|
||||
assert isinstance(response, Response) # help mypy
|
||||
self.response = response
|
||||
|
||||
# Reject the connection if the server started closing during the
|
||||
# opening handshake. Don't yield before send_response() to avoid
|
||||
# a race condition after checking if the server is closing.
|
||||
if (
|
||||
self.response.status_code == http.HTTPStatus.SWITCHING_PROTOCOLS
|
||||
and not self.server.is_serving()
|
||||
):
|
||||
self.response = self.protocol.reject(
|
||||
http.HTTPStatus.SERVICE_UNAVAILABLE,
|
||||
"Server is shutting down.\n",
|
||||
)
|
||||
|
||||
# Don't respond if the connection was closed during the handshake.
|
||||
if self.state is CONNECTING:
|
||||
async with self.send_context(expected_state=CONNECTING):
|
||||
self.protocol.send_response(self.response)
|
||||
|
||||
def process_event(self, event: Event) -> None:
|
||||
"""
|
||||
Process one incoming event.
|
||||
|
||||
"""
|
||||
# First event - handshake request.
|
||||
if self.request is None:
|
||||
assert isinstance(event, Request)
|
||||
self.request = event
|
||||
self.request_rcvd.set_result(None)
|
||||
# Later events - frames.
|
||||
else:
|
||||
super().process_event(event)
|
||||
|
||||
def connection_made(self, transport: asyncio.BaseTransport) -> None:
|
||||
super().connection_made(transport)
|
||||
# The handler task must be registered in self.handler_tasks now. If it
|
||||
# was registered inside the task, a race condition could happen when
|
||||
# closing the server after scheduling the task but before it executes.
|
||||
handler_task = self.loop.create_task(self.server.handler(self))
|
||||
self.server.handler_tasks.add(handler_task)
|
||||
|
||||
|
||||
class Server:
|
||||
"""
|
||||
WebSocket server returned by :func:`serve`.
|
||||
|
||||
This class mirrors most of the API of :class:`asyncio.Server`, with the
|
||||
following differences:
|
||||
|
||||
* You can invoke :func:`serve` as ``async with serve(...) as server: ...``
|
||||
in addition to ``server = await serve(...)`` to start the server.
|
||||
|
||||
* It doesn't provide ``close_clients`` or ``abort_clients``; by default,
|
||||
:meth:`close` closes existing connections with code 1001 (going away).
|
||||
|
||||
Args:
|
||||
handler: Handler for one connection. It receives an asyncio protocol.
|
||||
logger: Logger for this server.
|
||||
It defaults to ``logging.getLogger("websockets.server")``.
|
||||
See the :doc:`logging guide <../../topics/logging>` for details.
|
||||
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
create_server: Callable[[], Coroutine[Any, Any, asyncio.Server]],
|
||||
handler: Callable[[ServerConnection], Coroutine[Any, Any, None]],
|
||||
logger: LoggerLike | None = None,
|
||||
) -> None:
|
||||
self.create_server = create_server
|
||||
self.handler = handler
|
||||
if logger is None:
|
||||
logger = logging.getLogger("websockets.server")
|
||||
self.logger = logger
|
||||
|
||||
# Keep track of active connections and connection handler tasks.
|
||||
self.all_connections: set[ServerConnection] = set()
|
||||
self.handler_tasks: set[asyncio.Task[None]] = set()
|
||||
|
||||
# Task responsible for closing the server and terminating connections.
|
||||
self.close_task: asyncio.Task[None] | None = None
|
||||
|
||||
# Completed when the server is closed and connections are terminated.
|
||||
loop = asyncio.get_running_loop()
|
||||
self.handlers_waiter: asyncio.Future[None] = loop.create_future()
|
||||
|
||||
@property
|
||||
def connections(self) -> set[ServerConnection]:
|
||||
"""
|
||||
Set of active connections.
|
||||
|
||||
This property contains all connections that completed the opening
|
||||
handshake successfully and didn't start the closing handshake yet.
|
||||
It can be useful in combination with :func:`~broadcast`.
|
||||
|
||||
"""
|
||||
return {
|
||||
connection
|
||||
for connection in self.all_connections
|
||||
if connection.protocol.state is OPEN
|
||||
}
|
||||
|
||||
def close(
|
||||
self,
|
||||
close_connections: bool = True,
|
||||
code: CloseCode | int = CloseCode.GOING_AWAY,
|
||||
reason: str = "",
|
||||
) -> 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 code 1001 (going away).
|
||||
``code`` and ``reason`` can be customized, for example to use code
|
||||
1012 (service restart).
|
||||
|
||||
* Wait until all connection handlers have returned.
|
||||
|
||||
:meth:`close` is idempotent.
|
||||
|
||||
"""
|
||||
if self.close_task is None:
|
||||
self.close_task = self.get_loop().create_task(
|
||||
self._close(close_connections, code, reason)
|
||||
)
|
||||
|
||||
async def _close(
|
||||
self,
|
||||
close_connections: bool = True,
|
||||
code: CloseCode | int = CloseCode.GOING_AWAY,
|
||||
reason: str = "",
|
||||
) -> 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.
|
||||
|
||||
"""
|
||||
self.logger.info("server closing")
|
||||
|
||||
# Stop accepting new connections.
|
||||
# Also reject OPENING connections with HTTP 503 — see handshake().
|
||||
self.server.close()
|
||||
|
||||
# Close OPEN connections.
|
||||
if close_connections:
|
||||
close_tasks = [
|
||||
asyncio.create_task(connection.close(code, reason))
|
||||
for connection in self.all_connections
|
||||
if connection.protocol.state is OPEN
|
||||
]
|
||||
# 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 have returned.
|
||||
# asyncio.wait doesn't accept an empty first argument.
|
||||
if self.handler_tasks:
|
||||
await asyncio.wait(self.handler_tasks)
|
||||
|
||||
# Tell wait_closed() to return.
|
||||
self.handlers_waiter.set_result(None)
|
||||
|
||||
self.logger.info("server closed")
|
||||
|
||||
def get_loop(self) -> asyncio.AbstractEventLoop:
|
||||
"""
|
||||
See :meth:`asyncio.Server.get_loop`.
|
||||
|
||||
"""
|
||||
return self.server.get_loop()
|
||||
|
||||
async def start_serving(self) -> None:
|
||||
"""
|
||||
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:
|
||||
"""
|
||||
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` or by
|
||||
calling :meth:`~Server.close` from another task.
|
||||
|
||||
"""
|
||||
try:
|
||||
if not self.is_serving():
|
||||
await self.start_serving()
|
||||
# If close() is called, wait_closed() will return, and we'll exit.
|
||||
await self.wait_closed()
|
||||
except asyncio.CancelledError:
|
||||
try:
|
||||
self.close()
|
||||
await self.wait_closed()
|
||||
finally:
|
||||
raise
|
||||
|
||||
def is_serving(self) -> bool:
|
||||
"""
|
||||
See :meth:`asyncio.Server.is_serving`.
|
||||
|
||||
"""
|
||||
return self.server.is_serving()
|
||||
|
||||
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.handlers_waiter)
|
||||
|
||||
@property
|
||||
def sockets(self) -> tuple[socket.socket, ...]:
|
||||
"""
|
||||
See :attr:`asyncio.Server.sockets`.
|
||||
|
||||
"""
|
||||
return self.server.sockets
|
||||
|
||||
async def _await(self) -> Self:
|
||||
if not hasattr(self, "server"):
|
||||
self.server = await self.create_server()
|
||||
if self.server.is_serving():
|
||||
for sock in self.server.sockets:
|
||||
self.logger.info("server listening on %s", get_socket_name(sock))
|
||||
return self
|
||||
|
||||
def __await__(self) -> Generator[Any, None, Self]:
|
||||
# Create a suitable iterator by calling __await__ on a coroutine.
|
||||
return self._await().__await__()
|
||||
|
||||
async def __aenter__(self) -> Self:
|
||||
return await self
|
||||
|
||||
async def __aexit__(
|
||||
self,
|
||||
exc_type: type[BaseException] | None,
|
||||
exc_value: BaseException | None,
|
||||
traceback: TracebackType | None,
|
||||
) -> None:
|
||||
self.close()
|
||||
await self.wait_closed()
|
||||
|
||||
|
||||
# serve() is declared as a function rather than a coroutine in order to support
|
||||
# async with serve(...) as server: ... in addition to server = await serve(...).
|
||||
|
||||
|
||||
def serve(
|
||||
handler: Callable[[ServerConnection], Awaitable[None]],
|
||||
host: str | None = None,
|
||||
port: int | None = None,
|
||||
*,
|
||||
# WebSocket
|
||||
origins: Sequence[Origin | re.Pattern[str] | None] | None = None,
|
||||
extensions: Sequence[ServerExtensionFactory] | None = None,
|
||||
subprotocols: Sequence[Subprotocol] | None = None,
|
||||
select_subprotocol: (
|
||||
Callable[
|
||||
[ServerConnection, Sequence[Subprotocol]],
|
||||
Subprotocol | None,
|
||||
]
|
||||
| None
|
||||
) = None,
|
||||
compression: str | None = "deflate",
|
||||
# HTTP
|
||||
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,
|
||||
# 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,
|
||||
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,
|
||||
) -> Server:
|
||||
"""
|
||||
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 function returns a :class:`Server` object whose API mirrors
|
||||
:class:`asyncio.Server`. Treat it as an asynchronous context manager to
|
||||
serve requests and ensure that the server will be closed gracefully::
|
||||
|
||||
from websockets.asyncio.server import serve
|
||||
|
||||
async def handler(websocket):
|
||||
...
|
||||
|
||||
# set this event to exit the server
|
||||
stop = asyncio.Event()
|
||||
|
||||
async with serve(handler, host, port):
|
||||
await stop.wait()
|
||||
|
||||
Alternatively, await it and call :meth:`~Server.serve_forever` to serve
|
||||
requests, then cancel it to stop the server::
|
||||
|
||||
server = await serve(handler, host, port)
|
||||
await server.serve_forever()
|
||||
|
||||
Combining these two patterns works, but is unnecessary: when the context
|
||||
manager exits, :meth:`~Server.serve_forever` has already closed the server::
|
||||
|
||||
async with serve(handler, host, port) as server: # don't do this!
|
||||
await server.serve_forever() # it's redundant
|
||||
|
||||
You can also stop the server gracefully by calling its
|
||||
:meth:`~Server.close` method::
|
||||
|
||||
server = await serve(handler, host, port)
|
||||
try:
|
||||
await stop.wait()
|
||||
finally:
|
||||
server.close()
|
||||
await server.wait_closed()
|
||||
|
||||
By default, closing the server closes connections with code 1001 (going
|
||||
away). You can keep connections alive and wait for clients to disconnect::
|
||||
|
||||
server.close(close_connections=False)
|
||||
|
||||
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. Values can be
|
||||
:class:`str` to test for an exact match or regular expressions
|
||||
compiled by :func:`re.compile` to test against a pattern. 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.
|
||||
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.
|
||||
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.
|
||||
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. 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.
|
||||
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()`.
|
||||
|
||||
"""
|
||||
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
|
||||
|
||||
if kwargs.get("ssl") is not None:
|
||||
kwargs.setdefault("ssl_handshake_timeout", open_timeout)
|
||||
kwargs.setdefault("ssl_shutdown_timeout", close_timeout)
|
||||
|
||||
async def create_server() -> asyncio.Server:
|
||||
loop = asyncio.get_running_loop()
|
||||
if kwargs.pop("unix", False):
|
||||
return await loop.create_unix_server(protocol_factory, **kwargs)
|
||||
else:
|
||||
return await loop.create_server(protocol_factory, host, port, **kwargs)
|
||||
|
||||
def protocol_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,
|
||||
server,
|
||||
ping_interval=ping_interval,
|
||||
ping_timeout=ping_timeout,
|
||||
close_timeout=close_timeout,
|
||||
max_queue=max_queue,
|
||||
write_limit=write_limit,
|
||||
)
|
||||
return connection
|
||||
|
||||
async def protocol_handler(connection: ServerConnection) -> None:
|
||||
"""
|
||||
Handle the lifecycle of a WebSocket connection.
|
||||
|
||||
Since this coroutine 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:
|
||||
# Apply open_timeout to the WebSocket handshake.
|
||||
# Use ssl_handshake_timeout for the TLS handshake.
|
||||
async with asyncio.timeout(open_timeout):
|
||||
await connection.handshake(
|
||||
process_request,
|
||||
process_response,
|
||||
server_header,
|
||||
)
|
||||
|
||||
if connection.protocol.state is not OPEN:
|
||||
connection.transport.abort()
|
||||
return
|
||||
|
||||
server.all_connections.add(connection)
|
||||
connection.start_keepalive()
|
||||
try:
|
||||
async with connection:
|
||||
await handler(connection)
|
||||
except Exception:
|
||||
connection.logger.error("connection handler failed", exc_info=True)
|
||||
finally:
|
||||
server.all_connections.discard(connection)
|
||||
|
||||
except Exception:
|
||||
# Don't leak connections when the opening handshake times out or
|
||||
# an unexpected error occurs.
|
||||
connection.transport.abort()
|
||||
|
||||
finally:
|
||||
server.handler_tasks.discard(asyncio.current_task())
|
||||
|
||||
# The server variable is captured by the closure of conn_handler() and
|
||||
# protocol_factory().
|
||||
server = Server(create_server, protocol_handler, logger)
|
||||
return server
|
||||
|
||||
|
||||
def unix_serve(
|
||||
handler: Callable[[ServerConnection], Awaitable[None]],
|
||||
path: PathLike | None = None,
|
||||
**kwargs: Any,
|
||||
) -> 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
|
||||
Reference in New Issue
Block a user