Standardise sockets

[BiffoBear]

Updated adafruit_wiznet5k_socket.py to match as closely as possible CPython socket. Functions that exist in Cpython socket have matching parameters and return types. Functions that exist in wiznet5k socket but not in Cpython socket were renamed with a leading _ except socket.setinterface.

Main differences:

• flags still not implemented, not planned to be.
• socket.bind can only bind to the IP address that the Wiznet chip was initialized with. All the hardware sockets share this single address. Changing the IP address after initialization leaves previously connected sockets in an unknown state. Raises ValueError if the IP address does not match.
• socket.bind should raise an exception if the socket is already bound. Making this check currently causes socket.accept to fail because it calls 'bind' on a bound socket (now solved).

Not attempted, TODO: at a later date:

• Raise appropriate exceptions from adafruit_wiznet5k.py
• Refactor modules to stop calling socket nonstandard functions then remove nonstandard functions.

This has been tested by running simpletest.py and simpleserver.py.

More testing would be appreciated.

[FoamyGuy]

I have a few questions about possible tweaks.

I will also test this branch out on a device this week and report back how it goes.

Thank you again for all of the hard work you've put into the improvements for this library @BiffoBear!

[BiffoBear]

@FoamyGuy Please have a look at this too, the function can take either 2 or 3 args and CP does not support overloading, so I don't know how to type this function.

def sendto(self, data: bytearray, *flags_and_or_address: any) -> int:
        """
        Send data to the socket. The socket should not be connected to a remote socket, since the
        destination socket is specified by address. Return the number of bytes sent..

        Either:
        :param bytearray data: Data to send to the socket.
        :param [Tuple[str, int]] address: Remote socket as a (host, port) tuple.

        Or:
        :param bytearray data: Data to send to the socket.
        :param int flags: Not implemented, kept for compatibility.
        :param Tuple[int, Tuple(str, int)] address: Remote socket as a (host, port) tuple
        """

[BiffoBear]

Refactored bind() into bind() and _bind() to allow accept() to call bind on an already bound socket.

[FoamyGuy]

@FoamyGuy Please have a look at this too, the function can take either 2 or 3 args and CP does not support overloading, so I don't know how to type this function.

I saw that one. I Do think think way you've done it is good. I don't know of any better way that we could type / document it.

[FoamyGuy]

This is looking good to me.

I have tested this version successfully with a Feather ESP32-S2 TFT and Ethernet Featherwing with:

• wiznet5k_simpletest.py
• wiznet5k_simpleserver.py
• wiznet5k_wsgiserver.py
• wiznet5k_aio_post.py

and all are working as expected.

I also checked htonl() against the currently released version to ensure they output the same thing from same input. Lastly I compared inet_aton and inet_ntoa outputs to output from the same function from cpython built-in module socket. All are matching as expected.

Thank you again @BiffoBear for working on this and all of the other improvements!