CODEWITHSUNDEEP
pythonpython-asynciocoap
Siniyas
Siniyas

Reputation: 471

Trying to connect to coap resource with python library

So im trying to connect to a CoaP Resource using this python library https://github.com/chrysn/aiocoap . The library uses python 3.4 and i have 3.4 installed and set as the interpreter to use with this (Im on Windows 7 btw). Still im getting this error message, when executing the clientGET.py file. Same for the server file.

C:\Python34\python.exe C:/Learning/PyCoap/aiocoap/clientGET.py
Traceback (most recent call last):
  File "C:/Learning/PyCoap/aiocoap/clientGET.py", line 34, in <module>
    asyncio.get_event_loop().run_until_complete(main())
  File "C:\Python34\lib\asyncio\base_events.py", line 268, in run_until_complete
    return future.result()
  File "C:\Python34\lib\asyncio\futures.py", line 277, in result
    raise self._exception
  File "C:\Python34\lib\asyncio\tasks.py", line 236, in _step
    result = next(coro)
  File "C:/Learning/PyCoap/aiocoap/clientGET.py", line 20, in main
    protocol = yield from Context.create_client_context()
  File "C:\Learning\PyCoap\aiocoap\aiocoap\protocol.py", line 510, in create_client_context
    transport, protocol = yield from loop.create_datagram_endpoint(protofact, family=socket.AF_INET6)
  File "C:\Python34\lib\asyncio\base_events.py", line 675, in create_datagram_endpoint
    waiter)
  File "C:\Python34\lib\asyncio\selector_events.py", line 68, in _make_datagram_transport
    address, waiter, extra)
  File "C:\Python34\lib\asyncio\selector_events.py", line 911, in __init__
    super().__init__(loop, sock, protocol, extra)
  File "C:\Python34\lib\asyncio\selector_events.py", line 452, in __init__
    self._extra['sockname'] = sock.getsockname()
OSError: [WinError 10022] Ein ungultiges Argument wurde angegeben

Process finished with exit code 1

Upvotes: 1

Views: 1307

Answers (2)

chrysn
chrysn

Reputation: 928

You might want to retry with a current version of Python and aiocoap (current development version, after 0.4a1). Windows used not to be supported in aiocoap, and is still not supporting all of CoAP, but now uses a socket implementation that is aware of some limitations in the Windows socket API.

Upvotes: 1

clacke
clacke

Reputation: 8026

I didn't explore this in a real Python, as I don't have a Windows machine with Python 3.4 handy, but it seems to me that this could be a bug in asyncio. Its UDP socket creation probably simply doesn't work on Windows. Do some experimenting on the lower level, looking at what aiocoap is doing, and try to prove me wrong.

It's supposed to work, documentation only mentions ProactorEventLoop as not supporting UDP.

The error condition is described in Socket.error: Invalid Argument supplied .

aiocoap.protocol.Context.create_client_context() seems to be doing the right thing according to asyncio documentation, but _SelectorTransport.__init__() will always call sock.getsockname() before any packets are sent, at which point the socket will not be bound to an address (according to the linked SO question) and getsockname() will fail on Windows.

Upvotes: 1

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