cloudflare_ip_check.py

import ipaddress

from typing import Union, List


class Network:

    def __init__(self, network_ips: List[str]):
        self.nets = [ipaddress.ip_network(nip) for nip in network_ips]

    def __contains__(self, ip: Union[str, ipaddress.IPv4Address]):
        if isinstance(ip, str):
            ip = ipaddress.ip_address(ip)
        return any(ip in net for net in self.nets)


# https://www.cloudflare.com/ips-v4
CLOUDFLARE_IPS = [
    '103.21.244.0/22',
    '103.22.200.0/22',
    '103.31.4.0/22',
    '104.16.0.0/12',
    '108.162.192.0/18',
    '131.0.72.0/22',
    '141.101.64.0/18',
    '162.158.0.0/15',
    '172.64.0.0/13',
    '173.245.48.0/20',
    '188.114.96.0/20',
    '190.93.240.0/20',
    '197.234.240.0/22',
    '198.41.128.0/17',
]
cloudflare_network = Network(CLOUDFLARE_IPS)


if __name__ == '__main__':
    import sys
    assert '103.21.244.1' in cloudflare_network
    assert '100.21.244.1' not in cloudflare_network
    for ip in sys.argv[1:]:
        print(ip, ip in cloudflare_network)