fix bind_addr assignment for IPv6

[timbz]

As far as I can tell the if statement is not needed with IPv6. It actually fails on my machine with:

Traceback (most recent call last):
  File "monitor-sd.py", line 87, in <module>
    main()
  File "monitor-sd.py", line 79, in main
    asyncio.get_event_loop().run_until_complete(
  File "/usr/lib/python3.8/asyncio/base_events.py", line 616, in run_until_complete
    return future.result()
  File "monitor-sd.py", line 22, in run
    trsp_u, trsp_m, protocol = await SDProto.create_endpoints(
  File "/usr/local/lib/python3.8/dist-packages/someip/sd.py", line 380, in create_endpoints
    trsp_m = await cls._create_endpoint(
  File "/usr/local/lib/python3.8/dist-packages/someip/sd.py", line 254, in _create_endpoint
    trsp, _ = await loop.create_datagram_endpoint(
  File "/usr/lib/python3.8/asyncio/base_events.py", line 1265, in create_datagram_endpoint
    infos = await self._ensure_resolved(
  File "/usr/lib/python3.8/asyncio/base_events.py", line 1365, in _ensure_resolved
    return await loop.getaddrinfo(host, port, family=family, type=type,
  File "/usr/lib/python3.8/asyncio/base_events.py", line 825, in getaddrinfo
    return await self.run_in_executor(
  File "/usr/lib/python3.8/concurrent/futures/thread.py", line 57, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/usr/lib/python3.8/socket.py", line 918, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known

Some testing:

>socket.getaddrinfo("ff14::4:0%eth0.4", 30490)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.8/socket.py", line 918, in getaddrinfo
    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known

>socket.getaddrinfo("ff14::4:0", 30490)
[(<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('ff14::4:0', 30490, 0, 0)), (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_DGRAM: 2>, 17, '', ('ff14::4:0', 30490, 0, 0)), (<AddressFamily.AF_INET6: 10>, <SocketKind.SOCK_RAW: 3>, 0, '', ('ff14::4:0', 30490, 0, 0))]

[afflux]

Hi! Thanks for your PR. Please ignore the CI errors for now, they are unrelated.

I have to admit I'm no expert on IPv6 multicast addressing schemes, but I see that addresses in ff02::/16 really do require the scope suffix (which makes sense, as they are link-local). If other prefixes don't need it, I guess it could make sense to remove that logic and instead instruct the library user to provide it if necessary.

Just out of curiosity, what's your reasoning to use ff14::/16?

[timbz]

remove that logic and instead instruct the library user to provide it if necessary

Sounds like a good solution.

Just out of curiosity, what's your reasoning to use ff14::/16?

To be honest I never thought about it too much. The address comes from a requirement and I never challenged it (I'm not expert on IPv6 multicast addressing schemes too)