IPv4 helper methods.

ip_helpers.py

def uint(i):
  return 0xffffffff & i

def IP2Int(ip):
    o = map(int, ip.split('.'))
    res = (16777216 * o[0]) + (65536 * o[1]) + (256 * o[2]) + o[3]
    return res


def Int2IP(ipnum):
    o1 = int(ipnum / 16777216) % 256
    o2 = int(ipnum / 65536) % 256
    o3 = int(ipnum / 256) % 256
    o4 = int(ipnum) % 256
    return '%(o1)s.%(o2)s.%(o3)s.%(o4)s' % locals()


def isIPInCIDR(ip, cidr):
    parts = cidr.split('/')
    cidr_ip = parts[0]
    cidr_maskbit = parts[1]
    
    int_cidr_ip = IP2Int(cidr_ip)
    int_mask = 0xffffffff << (32 - int(cidr_maskbit))
    int_network = uint(int_cidr_ip & int_mask)
    int_broadcast = uint(int_network | (~int_mask))
    
    # print '{} = {}'.format(int_network, Int2IP(int_network))
    # print '{} = {}'.format(int_broadcast, Int2IP(int_broadcast))
    
    int_ip = IP2Int(ip)
    # print '{} = {}'.format(int_ip, Int2IP(int_ip))
    return int_ip >= int_network and int_ip <= int_broadcast