WSAAccept with Python and ctypes

gistfile1.py

import errno
import multiprocessing
import socket
import time

import ctypes
from ctypes import windll
from ctypes import POINTER, WINFUNCTYPE, c_char_p, c_char, c_int, c_ushort
from ctypes.wintypes import DWORD, UINT, INT, ULONG


SOCKET = UINT
SERVICETYPE = UINT
GROUP = UINT
DWORD_PTR = POINTER(DWORD)
LPINT = POINTER(INT)

CF_REJECT = 0x0001


class sockaddr(ctypes.Structure):
    _fields_ = [
        ('sa_family', c_ushort),
        ('sa_data', c_char * 14)
    ]


class WSABUF(ctypes.Structure):
    _fields_ = [
        ('len', ULONG),
        ('buf', c_char_p)
    ]

LPWSABUF = POINTER(WSABUF)


class FLOWSPEC(ctypes.Structure):
    _fields_ = [
        ('TokenRate', ULONG),
        ('TokenBucketSize', ULONG),
        ('PeakBandwidth', ULONG),
        ('Latency', ULONG),
        ('DelayVariation', ULONG),
        ('ServiceType', SERVICETYPE),
        ('MaxSduSize', ULONG),
        ('MinimumPolicedSize', ULONG),
    ]

LPQOS = POINTER(FLOWSPEC)


LPCONDITIONPROC = WINFUNCTYPE(
    c_int, LPWSABUF, LPWSABUF, LPQOS, LPQOS, LPWSABUF, LPWSABUF,
    POINTER(GROUP), DWORD_PTR)


@LPCONDITIONPROC
def cond_callback(*args):
    return CF_REJECT


lib = windll.LoadLibrary('Ws2_32')
WSAAccept = lib.WSAAccept
WSAAccept.argtypes = [SOCKET, POINTER(sockaddr), LPINT, LPCONDITIONPROC,
                      DWORD_PTR]
WSAAccept.restype = SOCKET


PORT = 50123


def server():
    s = socket.socket()
    s.bind(('127.0.0.1', PORT))
    s.listen(0)

    while True:
        print 'wait'
        sa_client = sockaddr()
        i_client_size = INT(ctypes.sizeof(sa_client))
        WSAAccept(s.fileno(), ctypes.byref(sa_client),
                  ctypes.byref(i_client_size), cond_callback, None)
        print 'refused', sa_client.sa_family, repr(sa_client.sa_data)


def main():
    p = multiprocessing.Process(target=server)
    p.daemon = True
    p.start()

    client = socket.socket()
    start = time.time()

    try:
        client.connect(('127.0.0.1', PORT))
    except socket.error as e:
        assert e.errno == errno.WSAECONNREFUSED
        print 'connection attempt took', time.time() - start

    client2 = socket.socket()
    start = time.time()

    try:
        client2.connect(('127.0.0.1', PORT))
    except socket.error as e:
        assert e.errno == errno.WSAECONNREFUSED
        print 'connection attempt took', time.time() - start
    finally:
        client.close()
        client2.close()

    p.join(1)


if __name__ == '__main__':
    main()

Reject not work as expected.