class IpUtils

FragmentListener.php in drupal/core/vendor/symfony/http-kernel/Symfony/Component/HttpKernel/EventListener/FragmentListener.php

IpUtilsTest.php in drupal/core/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Tests/IpUtilsTest.php

class IpUtils {

  /**
   * This class should not be instantiated
   */
  private function __construct() {
  }

  /**
   * Validates an IPv4 or IPv6 address.
   *
   * @param string       $requestIp
   * @param string|array $ips
   *
   * @return boolean Whether the IP is valid
   */
  public static function checkIp($requestIp, $ips) {
    if (!is_array($ips)) {
      $ips = array(
        $ips,
      );
    }
    $method = false !== strpos($requestIp, ':') ? 'checkIp6' : 'checkIp4';
    foreach ($ips as $ip) {
      if (self::$method($requestIp, $ip)) {
        return true;
      }
    }
    return false;
  }

  /**
   * Validates an IPv4 address.
   *
   * @param string $requestIp
   * @param string $ip
   *
   * @return boolean Whether the IP is valid
   */
  public static function checkIp4($requestIp, $ip) {
    if (false !== strpos($ip, '/')) {
      list($address, $netmask) = explode('/', $ip, 2);
      if ($netmask < 1 || $netmask > 32) {
        return false;
      }
    }
    else {
      $address = $ip;
      $netmask = 32;
    }
    return 0 === substr_compare(sprintf('%032b', ip2long($requestIp)), sprintf('%032b', ip2long($address)), 0, $netmask);
  }

  /**
   * Validates an IPv6 address.
   *
   * @author David Soria Parra <dsp at php dot net>
   * @see https://github.com/dsp/v6tools
   *
   * @param string $requestIp
   * @param string $ip
   *
   * @return boolean Whether the IP is valid
   *
   * @throws \RuntimeException When IPV6 support is not enabled
   */
  public static function checkIp6($requestIp, $ip) {
    if (!(extension_loaded('sockets') && defined('AF_INET6') || @inet_pton('::1'))) {
      throw new \RuntimeException('Unable to check Ipv6. Check that PHP was not compiled with option "disable-ipv6".');
    }
    if (false !== strpos($ip, '/')) {
      list($address, $netmask) = explode('/', $ip, 2);
      if ($netmask < 1 || $netmask > 128) {
        return false;
      }
    }
    else {
      $address = $ip;
      $netmask = 128;
    }
    $bytesAddr = unpack("n*", inet_pton($address));
    $bytesTest = unpack("n*", inet_pton($requestIp));
    for ($i = 1, $ceil = ceil($netmask / 16); $i <= $ceil; $i++) {
      $left = $netmask - 16 * ($i - 1);
      $left = $left <= 16 ? $left : 16;
      $mask = ~(0xffff >> $left) & 0xffff;
      if (($bytesAddr[$i] & $mask) != ($bytesTest[$i] & $mask)) {
        return false;
      }
    }
    return true;
  }

}