aiocoap + uvloop = Address family for hostname not supported

[lwis]

• uvloop version: 0.8.0
• Python version: 3.6
• Platform: Linux
• Can you reproduce the bug with PYTHONASYNCIODEBUG in env?: Yes

Not sure if this is an issue downstream with aiocoap, or uvloop. Looking for some information/direction.

Traceback (most recent call last):
  File "/usr/src/app/homeassistant/components/tradfri.py", line 98, in gateway_discovered
    allow_tradfri_groups)
  File "/usr/src/app/homeassistant/components/tradfri.py", line 118, in _setup_gateway
    api = yield from api_factory(host, key, loop=hass.loop)
  File "/usr/local/lib/python3.6/site-packages/pytradfri/api/aiocoap_api.py", line 135, in api_factory
    yield from request(Command('get', ['status']))
  File "/usr/local/lib/python3.6/site-packages/pytradfri/api/aiocoap_api.py", line 97, in request
    result = yield from _execute(api_commands[0])
  File "/usr/local/lib/python3.6/site-packages/pytradfri/api/aiocoap_api.py", line 84, in _execute
    protocol = yield from _get_protocol()
  File "/usr/local/lib/python3.6/site-packages/pytradfri/api/aiocoap_api.py", line 53, in _get_protocol
    protocol = yield from Context.create_client_context(loop=loop)
  File "/usr/local/lib/python3.6/site-packages/aiocoap/protocol.py", line 524, in create_client_context
    self.transport_endpoints.append((yield from TransportEndpointUDP6.create_client_transport_endpoint(new_message_callback=self._dispatch_message, new_error_callback=self._dispatch_error, log=self.log, loop=loop, dump_to=dump_to)))
  File "/usr/local/lib/python3.6/site-packages/aiocoap/transports/udp6.py", line 179, in create_client_transport_endpoint
    return (yield from cls._create_transport_endpoint(new_message_callback, new_error_callback, log, loop, dump_to, None, multicast=False))
  File "/usr/local/lib/python3.6/site-packages/aiocoap/transports/udp6.py", line 140, in _create_transport_endpoint
    transport, protocol = yield from loop.create_datagram_endpoint(protofact, family=socket.AF_INET6)
  File "uvloop/loop.pyx", line 2436, in create_datagram_endpoint (uvloop/loop.c:44170)
socket.gaierror: [Errno -9] Address family for hostname not supported

Ref: home-assistant/core#7815

[myusuf3]

any updates on this? blocking progress up stream willing to work to get it fixed.

[1st1]

Sorry, no update as of yet. I'm a bit behind on releasing a new uvloop version with fixes to all open issues. Will try to dedicate a few days closer to the end of the week. If you are willing to make a PR fixing this go ahead!

[myusuf3]

@1st1 can you tell where the issue is? how you would go about fixing it, I can dive in. Thanks for responding so quick.

[tomitm]

I believe I know what the issue is, but not familiar enough to setup and test this - feel free to give this a try @myusuf3.

Looking at the trace, the issue is here while aiocoap called with family=socket.AF_INET6.

uvloop/uvloop/loop.pyx

Lines 2421 to 2436 in 490c410

	if rads is not None:
	udp = UDPTransport.__new__(UDPTransport)
	rai = (<AddrInfo>rads).data
	udp._init(self, rai.ai_family)
	udp._set_remote_address(rai.ai_addr, rai.ai_addrlen)
	else:
	if family not in (uv.AF_INET, uv.AF_INET6):
	raise ValueError('unexpected address family')
	udp = UDPTransport.__new__(UDPTransport)
	udp._init(self, family)
	if reuse_port:
	self._sock_set_reuseport(udp._fileno())
	socket = udp._get_socket()
	socket.bind(('0.0.0.0', 0))

It's an IPv6 socket binding to an IPv4 address. 0.0.0.0 is not a valid IPv6 address, hence the Address family for hostname not supported error.

Should check if family is AF_INET6 and bind to :: or ::/0 instead, which is the IPv6 equivalent of 0.0.0.0.

[lwis]

@myusuf3 is this something you could take a look at? If not I can probably set some time aside in a 3-4 days.

[1st1]

I'll fix this on Monday.

[lwis]

@1st1 you da man, let us know if you need us to test bud 👍

[lwis]

For those interested, I just tested a quick fix for this;

https://github.com/chrysn/aiocoap/blob/a2c2abe28107af0d492fac715f915dd3307d4a31/aiocoap/transports/udp6.py#L142 fails with;

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/homeassistant/setup.py", line 191, in _async_setup_component
    result = yield from component.async_setup(hass, processed_config)
  File "/usr/lib/python3.6/site-packages/homeassistant/components/tradfri.py", line 107, in async_setup
    allow_tradfri_groups))
  File "/usr/lib/python3.6/site-packages/homeassistant/components/tradfri.py", line 121, in _setup_gateway
    api = yield from api_factory(host, key, loop=hass.loop)
  File "/config/deps/lib/python3.6/site-packages/pytradfri/api/aiocoap_api.py", line 46, in api_factory
    _protocol = yield from Context.create_client_context(loop=loop)
  File "/usr/lib/python3.6/site-packages/aiocoap/protocol.py", line 524, in create_client_context
    self.transport_endpoints.append((yield from TransportEndpointUDP6.create_client_transport_endpoint(new_message_callback=self._dispatch_message, new_error_callback=s$
lf._dispatch_error, log=self.log, loop=loop, dump_to=dump_to)))
  File "/usr/lib/python3.6/site-packages/aiocoap/transports/udp6.py", line 179, in create_client_transport_endpoint
    return (yield from cls._create_transport_endpoint(new_message_callback, new_error_callback, log, loop, dump_to, None, multicast=False))
  File "/usr/lib/python3.6/site-packages/aiocoap/transports/udp6.py", line 142, in _create_transport_endpoint
    sock = transport._sock
AttributeError: 'uvloop.loop.UDPTransport' object has no attribute '_sock'

[myusuf3]

@1st1 huzzah!!

[1st1]

Just pushed a commit to master that should fix this. Could someone please try it out?

[terrisgit]

I am also hitting this problem. Thank you for this package!

[1st1]

I'll wait till tomorrow if someone tries the master branch out and confirms that the problem is fixed. If not, I'll issue a minor uvloop release tomorrow morning.