Sockets and structure

#!/usr/bin/env python3

from ctypes import *
import struct
import socket

host = '192.168.0.9'


class IP(Structure):
    _fields_ = [
        ("ihl", c_ubyte, 4),
        ("version", c_ubyte, 4),
        ("tos", c_ubyte),
        ("len", c_ushort),
        ("id", c_ushort),
        ("offset", c_ushort),
        ("ttl", c_ubyte),
        ("protocol_num", c_ubyte),
        ("sum", c_ushort),
        ("src", c_int),
        ("dst", c_int)
    ]

    def __init__(self, socket_buffer=None):
        self.protocol_map = {1: 'ICMP', 6: 'TCP', 17: 'UDP'}

        self.src_address = socket.inet_ntoa(struct.pack('<L', self.src))
        self.dst_address = socket.inet_ntoa(struct.pack('<L', self.dst))

        self.protocol = self.protocol_map[self.protocol_num]

    def __new__(cls, socket_buffer=None):
        return cls.from_buffer_copy(socket_buffer)


socket_protocol = socket.IPPROTO_UDP
sock = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket_protocol)
sock.bind((host, 0))

sock.setsockopt(socket.IPPROTO_IP, socket.IP_HDRINCL, 1)

try:

    while True:
        raw_buffer = sock.recvfrom(65565)[0]
        ip_header = IP(raw_buffer[:20])
        print('Protocol: {} {} -> {}'.format(ip_header.protocol, ip_header.src_address, ip_header.dst_address))

except KeyboardInterrupt:
    print('\rExiting...')