Check if a given IPV4 belongs to Cloudflare. Usage : `php is-cloudflare-ip.php 108.162.242.71`

is-cloudflare-ip.php

<?php

/**
 * Check if a given ip is in a network.
 *
 * @link https://gist.github.com/tott/7684443
 *
 * @param  string $ip    IP to check in IPV4 format eg. 127.0.0.1
 * @param  string $range IP/CIDR netmask eg. 127.0.0.0/24, also 127.0.0.1 is accepted and /32 assumed
 *
 * @return boolean true if the ip is in this range / false if not.
 */
function ip_in_range($ip, $range)
{
    if (strpos($range, '/') == false) {
        $range .= '/32';
    }
    // $range is in IP/CIDR format eg 127.0.0.1/24
    list($range, $netmask) = explode('/', $range, 2);
    $range_decimal = ip2long($range);
    $ip_decimal = ip2long($ip);
    $wildcard_decimal = pow(2, (32 - $netmask)) - 1;
    $netmask_decimal = ~ $wildcard_decimal;

    return (($ip_decimal & $netmask_decimal) == ($range_decimal & $netmask_decimal));
}

/**
 * Check if a given IPV4 belongs to Cloudflare.
 *
 * @param  string $ip    IP to check in IPV4 format eg. 127.0.0.1
 *
 * @return boolean true if the ip belongs to Cloudflare / false if not.
 */
function is_cloudflare($ip)
{
    $cf_ips = array(
        '199.27.128.0/21',
        '173.245.48.0/20',
        '103.21.244.0/22',
        '103.22.200.0/22',
        '103.31.4.0/22',
        '141.101.64.0/18',
        '108.162.192.0/18',
        '190.93.240.0/20',
        '188.114.96.0/20',
        '197.234.240.0/22',
        '198.41.128.0/17',
        '162.158.0.0/15',
        '104.16.0.0/12',
    );

    $is_cf_ip = false;

    foreach ($cf_ips as $cf_ip) {
        if (ip_in_range($ip, $cf_ip)) {
            $is_cf_ip = true;
            break;
        }
    }

    return $is_cf_ip;
}

if (empty($argv[1])) {
    exit(sprintf("Usage: php %s XXX.XXX.XXX.XXX\n", $argv[0]));
}

printf("%s is %sa Cloudflare IP\n", $argv[1], is_cloudflare($argv[1]) ? '' : 'not ');