ip_in_cidr.py

import struct
import socket


def ip2int(addr):
    return struct.unpack("!I", socket.inet_aton(addr))[0]


def int2ip(addr):
    return socket.inet_ntoa(struct.pack("!I", addr))


def get_range(addr, mask):
    addr = addr.split('_')

    if len(addr) != 4:
        return 'Invalid cidr'

    for i in addr:
        if int(i) > 255:
            return 'Invalid cidr'

    addr = '.'.join(addr)

    first = ip2int(addr) & (-1 << 32 - mask)
    last = first + pow(2, 32 - mask) - 1

    return {'first_ip': int2ip(first + 1), 'last_ip': int2ip(last)}


def check_in_range(addr_1, addr_2, mask):
    addr_1 = addr_1.split('_')
    addr_2 = addr_2.split('_')

    if len(addr_1) != 4 or len(addr_2) != 4:
        return 'Invalid cidr'

    for i in addr_1:
        if int(i) > 255:
            return 'Invalid cidr'

    for i in addr_2:
        if int(i) > 255:
            return 'Invalid cidr'

    addr_1 = '.'.join(addr_1)
    addr_2 = '.'.join(addr_2)

    first = ip2int(addr_2) & (-1 << 32 - mask)
    last = first + pow(2, 32 - mask) - 1

    if ip2int(addr_1) > first and ip2int(addr_1) < last:
        return True
    else:
        return False