vlan

# -*- coding: utf-8 -*-
# Copyright (c) 2009 Andrey Vlasovskikh

from __future__ import with_statement
import os, socket, errno
from itertools import imap
from contextlib import closing
from pprint import pformat

NETLINK_KOBJECT_UEVENT = 15
UEVENT_DEFAULT_GROUP = 0

def parse_message(data):
    'bytes -> (bytes, {bytes: bytes})'
    lines = data.split('\x00')
    name = lines[0]
    attrs = dict(tuple(x.split('=', 1)) for x in lines[1:] if x != '')
    return (name, attrs)

def make_socket(group):
    'int -> socket'
    s = socket.socket(socket.AF_NETLINK, socket.SOCK_DGRAM,
        NETLINK_KOBJECT_UEVENT)
    try:
        s.bind((os.getpid(), netlink_group(group)))
        return s
    except:
        s.close()
        raise

def recv_msgs(s):
    'socket -> Iterable((bytes, {bytes: bytes}))'
    BUFSIZE = 65536
    return imap(parse_message, iter(lambda: s.recv(BUFSIZE), ''))

def netlink_group(n):
    'int -> int'
    return 1 << n

def main():
    with closing(make_socket(UEVENT_DEFAULT_GROUP)) as s:
        for msg in recv_msgs(s):
            print pformat(msg)

if __name__ == '__main__':
    try:
        main()
    except KeyboardInterrupt:
        pass