Proyectos de Subversion Moodle

<?php

declare(strict_types=1);

namespace GeoIp2;

class Util

{

    /**

     * This returns the network in CIDR notation for the given IP and prefix

     * length. This is for internal use only.

     *

     * @internal

     *

     * @ignore

     */

    public static function cidr(string $ipAddress, int $prefixLen): string

    {

        $ipBytes = inet_pton($ipAddress);

        $networkBytes = str_repeat("\0", \strlen($ipBytes));

        $curPrefix = $prefixLen;

        for ($i = 0; $i < \strlen($ipBytes) && $curPrefix > 0; $i++) {

            $b = $ipBytes[$i];

            if ($curPrefix < 8) {

                $shiftN = 8 - $curPrefix;

                $b = \chr(0xFF & (\ord($b) >> $shiftN) << $shiftN);

            }

            $networkBytes[$i] = $b;

            $curPrefix -= 8;

        }

        $network = inet_ntop($networkBytes);

        return "$network/$prefixLen";

    }

}