Fix websocket connection leak (#7978)

Author: bdraco

CHANGES/7978.bugfix

@@ -0,0 +1 @@
+Fix websocket connection leak

aiohttp/web_ws.py

@@ -162,9 +162,8 @@ def _send_heartbeat(self) -> None:
     def _pong_not_received(self) -> None:
         if self._req is not None and self._req.transport is not None:
             self._closed = True
-            self._close_code = WSCloseCode.ABNORMAL_CLOSURE
+            self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
             self._exception = asyncio.TimeoutError()
-            self._req.transport.close()
 
     async def prepare(self, request: BaseRequest) -> AbstractStreamWriter:
         # make pre-check to don't hide it by do_handshake() exceptions
@@ -382,7 +381,10 @@ async def write_eof(self) -> None:  # type: ignore[override]
         await self.close()
         self._eof_sent = True
 
-    async def close(self, *, code: int = WSCloseCode.OK, message: bytes = b"") -> bool:
+    async def close(
+        self, *, code: int = WSCloseCode.OK, message: bytes = b"", drain: bool = True
+    ) -> bool:
+        """Close websocket connection."""
         if self._writer is None:
             raise RuntimeError("Call .prepare() first")
 
@@ -396,46 +398,53 @@ async def close(self, *, code: int = WSCloseCode.OK, message: bytes = b"") -> bo
             reader.feed_data(WS_CLOSING_MESSAGE, 0)
             await self._waiting
 
-        if not self._closed:
-            self._closed = True
-            try:
-                await self._writer.close(code, message)
-                writer = self._payload_writer
-                assert writer is not None
-                await writer.drain()
-            except (asyncio.CancelledError, asyncio.TimeoutError):
-                self._close_code = WSCloseCode.ABNORMAL_CLOSURE
-                raise
-            except Exception as exc:
-                self._close_code = WSCloseCode.ABNORMAL_CLOSURE
-                self._exception = exc
-                return True
+        if self._closed:
+            return False
 
-            if self._closing:
-                return True
+        self._closed = True
+        try:
+            await self._writer.close(code, message)
+            writer = self._payload_writer
+            assert writer is not None
+            if drain:
+                await writer.drain()
+        except (asyncio.CancelledError, asyncio.TimeoutError):
+            self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
+            raise
+        except Exception as exc:
+            self._exception = exc
+            self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
+            return True
 
-            reader = self._reader
-            assert reader is not None
-            try:
-                async with async_timeout.timeout(self._timeout):
-                    msg = await reader.read()
-            except asyncio.CancelledError:
-                self._close_code = WSCloseCode.ABNORMAL_CLOSURE
-                raise
-            except Exception as exc:
-                self._close_code = WSCloseCode.ABNORMAL_CLOSURE
-                self._exception = exc
-                return True
+        if self._closing:
+            return True
 
-            if msg.type == WSMsgType.CLOSE:
-                self._close_code = msg.data
-                return True
+        reader = self._reader
+        assert reader is not None
+        try:
+            async with async_timeout.timeout(self._timeout):
+                msg = await reader.read()
+        except asyncio.CancelledError:
+            self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
+            raise
+        except Exception as exc:
+            self._exception = exc
+            self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
+            return True
 
-            self._close_code = WSCloseCode.ABNORMAL_CLOSURE
-            self._exception = asyncio.TimeoutError()
+        if msg.type == WSMsgType.CLOSE:
+            self._set_code_close_transport(msg.data)
             return True
-        else:
-            return False
+
+        self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
+        self._exception = asyncio.TimeoutError()
+        return True
+
+    def _set_code_close_transport(self, code: WSCloseCode) -> None:
+        """Set the close code and close the transport."""
+        self._close_code = code
+        if self._req is not None and self._req.transport is not None:
+            self._req.transport.close()
 
     async def receive(self, timeout: Optional[float] = None) -> WSMessage:
         if self._reader is None:
@@ -466,7 +475,7 @@ async def receive(self, timeout: Optional[float] = None) -> WSMessage:
                     set_result(waiter, True)
                     self._waiting = None
             except (asyncio.CancelledError, asyncio.TimeoutError):
-                self._close_code = WSCloseCode.ABNORMAL_CLOSURE
+                self._set_code_close_transport(WSCloseCode.ABNORMAL_CLOSURE)
                 raise
             except EofStream:
                 self._close_code = WSCloseCode.OK
@@ -488,7 +497,11 @@ async def receive(self, timeout: Optional[float] = None) -> WSMessage:
                 self._close_code = msg.data
                 # Could be closed while awaiting reader.
                 if not self._closed and self._autoclose:  # type: ignore[redundant-expr]
-                    await self.close()
+                    # The client is likely going to close the
+                    # connection out from under us so we do not
+                    # want to drain any pending writes as it will
+                    # likely result writing to a broken pipe.
+                    await self.close(drain=False)
             elif msg.type == WSMsgType.CLOSING:
                 self._closing = True
             elif msg.type == WSMsgType.PING and self._autoping:

docs/web_reference.rst

@@ -988,6 +988,14 @@ and :ref:`aiohttp-web-signals` handlers::
 
       .. versionadded:: 3.3
 
+   :param bool autoclose: Close connection when the client sends
+                           a :const:`~aiohttp.WSMsgType.CLOSE` message,
+                           ``True`` by default. If set to ``False``,
+                           the connection is not closed and the
+                           caller is responsible for calling
+                           ``request.transport.close()`` to avoid
+                           leaking resources.
+
 
    The class supports ``async for`` statement for iterating over
    incoming messages::
@@ -1164,7 +1172,7 @@ and :ref:`aiohttp-web-signals` handlers::
          The method is converted into :term:`coroutine`,
          *compress* parameter added.
 
-   .. method:: close(*, code=WSCloseCode.OK, message=b'')
+   .. method:: close(*, code=WSCloseCode.OK, message=b'', drain=True)
       :async:
 
       A :ref:`coroutine<coroutine>` that initiates closing
@@ -1178,6 +1186,8 @@ and :ref:`aiohttp-web-signals` handlers::
                       :class:`str` (converted to *UTF-8* encoded bytes)
                       or :class:`bytes`.
 
+      :param bool drain: drain outgoing buffer before closing connection.
+
       :raise RuntimeError: if connection is not started
 
    .. method:: receive(timeout=None)

tests/test_web_websocket.py

@@ -1,5 +1,6 @@
 # type: ignore
 import asyncio
+import time
 from typing import Any
 from unittest import mock
 
@@ -139,6 +140,20 @@ async def test_write_non_prepared() -> None:
         await ws.write(b"data")
 
 
+async def test_heartbeat_timeout(make_request: Any) -> None:
+    """Verify the transport is closed when the heartbeat timeout is reached."""
+    loop = asyncio.get_running_loop()
+    future = loop.create_future()
+    req = make_request("GET", "/")
+    lowest_time = time.get_clock_info("monotonic").resolution
+    req._protocol._timeout_ceil_threshold = lowest_time
+    ws = WebSocketResponse(heartbeat=lowest_time, timeout=lowest_time)
+    await ws.prepare(req)
+    ws._req.transport.close.side_effect = lambda: future.set_result(None)
+    await future
+    assert ws.closed
+
+
 def test_websocket_ready() -> None:
     websocket_ready = WebSocketReady(True, "chat")
     assert websocket_ready.ok is True
@@ -207,6 +222,7 @@ async def test_send_str_closed(make_request: Any) -> None:
     await ws.prepare(req)
     ws._reader.feed_data(WS_CLOSED_MESSAGE, 0)
     await ws.close()
+    assert len(ws._req.transport.close.mock_calls) == 1
 
     with pytest.raises(ConnectionError):
         await ws.send_str("string")
@@ -263,6 +279,8 @@ async def test_close_idempotent(make_request: Any) -> None:
     ws._reader.feed_data(WS_CLOSED_MESSAGE, 0)
     assert await ws.close(code=1, message="message1")
     assert ws.closed
+    assert len(ws._req.transport.close.mock_calls) == 1
+
     assert not (await ws.close(code=2, message="message2"))
 
 
@@ -296,12 +314,15 @@ async def test_write_eof_idempotent(make_request: Any) -> None:
     req = make_request("GET", "/")
     ws = WebSocketResponse()
     await ws.prepare(req)
+    assert len(ws._req.transport.close.mock_calls) == 0
+
     ws._reader.feed_data(WS_CLOSED_MESSAGE, 0)
     await ws.close()
 
     await ws.write_eof()
     await ws.write_eof()
     await ws.write_eof()
+    assert len(ws._req.transport.close.mock_calls) == 1
 
 
 async def test_receive_eofstream_in_reader(make_request: Any, loop: Any) -> None:
@@ -327,6 +348,7 @@ async def test_receive_timeouterror(make_request: Any, loop: Any) -> None:
     req = make_request("GET", "/")
     ws = WebSocketResponse()
     await ws.prepare(req)
+    assert len(ws._req.transport.close.mock_calls) == 0
 
     ws._reader = mock.Mock()
     res = loop.create_future()
@@ -336,6 +358,8 @@ async def test_receive_timeouterror(make_request: Any, loop: Any) -> None:
     with pytest.raises(asyncio.TimeoutError):
         await ws.receive()
 
+    assert len(ws._req.transport.close.mock_calls) == 1
+
 
 async def test_multiple_receive_on_close_connection(make_request: Any) -> None:
     req = make_request("GET", "/")
@@ -367,13 +391,15 @@ async def test_close_exc(make_request: Any) -> None:
     req = make_request("GET", "/")
     ws = WebSocketResponse()
     await ws.prepare(req)
+    assert len(ws._req.transport.close.mock_calls) == 0
 
     exc = ValueError()
     ws._writer = mock.Mock()
     ws._writer.close.side_effect = exc
     await ws.close()
     assert ws.closed
     assert ws.exception() is exc
+    assert len(ws._req.transport.close.mock_calls) == 1
 
     ws._closed = False
     ws._writer.close.side_effect = asyncio.CancelledError()