[3.12] gh-91227: Ignore ERROR_PORT_UNREACHABLE in proactor recvfrom() (GH-32011) (GH-117209)

(cherry picked from commit f11d0d8be8af28e1368c3c7c116218cf65ddf93e)

Co-authored-by: Erik Soma <stillusingirc@gmail.com>

1 files changed, 17 insertions, 12 deletions

diff --git a/Lib/asyncio/windows_events.py b/Lib/asyncio/windows_events.py
index c71f401..cb61345 100644
--- a/Lib/asyncio/windows_events.py
+++ b/Lib/asyncio/windows_events.py
@@ -8,6 +8,7 @@ if sys.platform != 'win32':  # pragma: no cover
 import _overlapped
 import _winapi
 import errno
+from functools import partial
 import math
 import msvcrt
 import socket
@@ -466,6 +467,18 @@ class IocpProactor:
             else:
                 raise
 
+    @classmethod
+    def _finish_recvfrom(cls, trans, key, ov, *, empty_result):
+        try:
+            return cls.finish_socket_func(trans, key, ov)
+        except OSError as exc:
+            # WSARecvFrom will report ERROR_PORT_UNREACHABLE when the same
+            # socket is used to send to an address that is not listening.
+            if exc.winerror == _overlapped.ERROR_PORT_UNREACHABLE:
+                return empty_result, None
+            else:
+                raise
+
     def recv(self, conn, nbytes, flags=0):
         self._register_with_iocp(conn)
         ov = _overlapped.Overlapped(NULL)
@@ -500,7 +513,8 @@ class IocpProactor:
         except BrokenPipeError:
             return self._result((b'', None))
 
-        return self._register(ov, conn, self.finish_socket_func)
+        return self._register(ov, conn, partial(self._finish_recvfrom,
+                                                empty_result=b''))
 
     def recvfrom_into(self, conn, buf, flags=0):
         self._register_with_iocp(conn)
@@ -510,17 +524,8 @@ class IocpProactor:
         except BrokenPipeError:
             return self._result((0, None))
 
-        def finish_recv(trans, key, ov):
-            try:
-                return ov.getresult()
-            except OSError as exc:
-                if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED,
-                                    _overlapped.ERROR_OPERATION_ABORTED):
-                    raise ConnectionResetError(*exc.args)
-                else:
-                    raise
-
-        return self._register(ov, conn, finish_recv)
+        return self._register(ov, conn, partial(self._finish_recvfrom,
+                                                empty_result=0))
 
     def sendto(self, conn, buf, flags=0, addr=None):
         self._register_with_iocp(conn)