Accept method

[AdamCummick]

Adds socket accept API
Adds context manager methods for socket
Adds setter for socket socknum
Adds status property for socket
Corrects bug in remote_port method

Tested with a SAMD51 running CircuitPython 6.0.0

CircuitPython test code:

import time
import board
import busio
import digitalio
import adafruit_requests as requests
from adafruit_wiznet5k.adafruit_wiznet5k import WIZNET5K
import adafruit_wiznet5k.adafruit_wiznet5k_socket as socket

cs = digitalio.DigitalInOut(board.D5)
spi_bus = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)
eth = WIZNET5K(spi_bus, cs, is_dhcp=False, debug=False)

socket.set_interface(eth)
s = socket.socket()
HOST = '192.168.3.56'  # Standard loopback interface address (localhost)
PORT = 65432        # Port to listen on (non-privileged ports are > 1023)

s.bind((HOST, PORT)) # Bind to IP and Port
s.listen() # begin listening

while True:
    listen_status = eth.socket_status(s.socknum)
    conn, addr = s.accept()
    with conn:
        data = conn.recv()
        print(f"data is {data}")
        conn.send(data)

Python client test code:

import time
import socket

HOST = '192.168.3.56'  # The server's hostname or IP address
PORT = 65432        # The port used by the server
while True:

    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.connect((HOST, PORT))
        s.sendall(b'Hello, world')
        data = s.recv(1024)
        print('Received', repr(data))
        time.sleep(1)

[brentru]

@AdamCummick Could you move the test code for this to the examples/ folder as adafruit_wiznet5k_simpleserver.py or similar? I think it'll be useful for others to build off of.

[AdamCummick]

@brentru Didn't see your message until after that last commit. I'll get a more standard looking example off of the test code shortly.

[brentru]

@AdamCummick Thanks for adding the accept method - I have some suggestions and comments.

[AdamCummick]

@brentru I added the requested changes as well as the example.

[brentru]

one little q

[AdamCummick]

Noticed an occasional bug where a zero length packet would be read. Wireshark was flagging a duplicate ACK. This was corrected by adding a wait state for the socket to actually close in the exit method.