bpo-31922: Do not connect UDP sockets when broadcast is allowed (GH-423)
*Moved from python/asyncio#493.*
This PR fixes issue python/asyncio#480, as explained in [this comment](https://github.com/python/asyncio/issues/480#issuecomment-278703828).
The `_SelectorDatagramTransport.sendto` method has to be modified ~~so `_sock.sendto` is used in all cases (because it is tricky to reliably tell if the socket is connected or not). Could that be an issue for connected sockets?~~ *EDIT* ... so `_sock.send` is used only if `_sock` is connected.
It also protects `socket.getsockname` against `OSError` in `_SelectorTransport`. This might happen on Windows if the socket is not connected (e.g. for UDP broadcasting).
https://bugs.python.org/issue31922
diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
index c58906f..9613ac2 100644
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -1306,7 +1306,8 @@
if local_addr:
sock.bind(local_address)
if remote_addr:
- await self.sock_connect(sock, remote_address)
+ if not allow_broadcast:
+ await self.sock_connect(sock, remote_address)
r_addr = remote_address
except OSError as exc:
if sock is not None:
diff --git a/Lib/asyncio/selector_events.py b/Lib/asyncio/selector_events.py
index 93b6889..2996821 100644
--- a/Lib/asyncio/selector_events.py
+++ b/Lib/asyncio/selector_events.py
@@ -587,7 +587,10 @@
def __init__(self, loop, sock, protocol, extra=None, server=None):
super().__init__(extra, loop)
self._extra['socket'] = sock
- self._extra['sockname'] = sock.getsockname()
+ try:
+ self._extra['sockname'] = sock.getsockname()
+ except OSError:
+ self._extra['sockname'] = None
if 'peername' not in self._extra:
try:
self._extra['peername'] = sock.getpeername()
@@ -976,9 +979,11 @@
if not data:
return
- if self._address and addr not in (None, self._address):
- raise ValueError(
- f'Invalid address: must be None or {self._address}')
+ if self._address:
+ if addr not in (None, self._address):
+ raise ValueError(
+ f'Invalid address: must be None or {self._address}')
+ addr = self._address
if self._conn_lost and self._address:
if self._conn_lost >= constants.LOG_THRESHOLD_FOR_CONNLOST_WRITES:
@@ -989,7 +994,7 @@
if not self._buffer:
# Attempt to send it right away first.
try:
- if self._address:
+ if self._extra['peername']:
self._sock.send(data)
else:
self._sock.sendto(data, addr)
@@ -1012,7 +1017,7 @@
while self._buffer:
data, addr = self._buffer.popleft()
try:
- if self._address:
+ if self._extra['peername']:
self._sock.send(data)
else:
self._sock.sendto(data, addr)
diff --git a/Lib/test/test_asyncio/test_base_events.py b/Lib/test/test_asyncio/test_base_events.py
index c245c47..25420b2 100644
--- a/Lib/test/test_asyncio/test_base_events.py
+++ b/Lib/test/test_asyncio/test_base_events.py
@@ -1586,6 +1586,23 @@
self.assertRaises(
OSError, self.loop.run_until_complete, coro)
+ def test_create_datagram_endpoint_allow_broadcast(self):
+ protocol = MyDatagramProto(create_future=True, loop=self.loop)
+ self.loop.sock_connect = sock_connect = mock.Mock()
+ sock_connect.return_value = []
+
+ coro = self.loop.create_datagram_endpoint(
+ lambda: protocol,
+ remote_addr=('127.0.0.1', 0),
+ allow_broadcast=True)
+
+ transport, _ = self.loop.run_until_complete(coro)
+ self.assertFalse(sock_connect.called)
+
+ transport.close()
+ self.loop.run_until_complete(protocol.done)
+ self.assertEqual('CLOSED', protocol.state)
+
@patch_socket
def test_create_datagram_endpoint_socket_err(self, m_socket):
m_socket.getaddrinfo = socket.getaddrinfo
diff --git a/Lib/test/test_asyncio/test_selector_events.py b/Lib/test/test_asyncio/test_selector_events.py
index d0d171a..bf721b0 100644
--- a/Lib/test/test_asyncio/test_selector_events.py
+++ b/Lib/test/test_asyncio/test_selector_events.py
@@ -1065,6 +1065,7 @@
self.sock.fileno.return_value = 7
def datagram_transport(self, address=None):
+ self.sock.getpeername.side_effect = None if address else OSError
transport = _SelectorDatagramTransport(self.loop, self.sock,
self.protocol,
address=address)
diff --git a/Misc/NEWS.d/next/Library/2018-05-30-01-05-50.bpo-31922.fobsXJ.rst b/Misc/NEWS.d/next/Library/2018-05-30-01-05-50.bpo-31922.fobsXJ.rst
new file mode 100644
index 0000000..df3881b
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-05-30-01-05-50.bpo-31922.fobsXJ.rst
@@ -0,0 +1,3 @@
+:meth:`asyncio.AbstractEventLoop.create_datagram_endpoint`:
+Do not connect UDP socket when broadcast is allowed.
+This allows to receive replies after a UDP broadcast.