Limit IP range for registrations?

require PUN_ROOT.'lang/'.$pun_user['language'].'/prof_reg.php';

/**
 * - Limit allowed IP ranges during registration -
 *
 * Step 1:
 *
 * Array of allowed IP ranges. I'm using only the first 3 blocks here, so if you
 * need to be more specific you'll have to change the regex in step #2. Just add
 * addresses in the same way as I've written the example IP's.
 */

$pun_allow_ip_ranges = array(
    '127.0.0',
    '192.168.1'
);

/**
 * Step 2:
 *
 * Get the first 3 blocks from the users IP address, and capture it into the
 * $user_ip variable, then check if it is within the allowed range. If we can't
 * get the users IP address for whatever reason, we will also exit with a
 * "bad request" message.
 */

if( preg_match('#(\d{1,3}\.\d{1,3}\.\d{1,3})\.\d{1,3}#', get_remote_address(), $user_ip) ) {
    if( !in_array($user_ip[1], $pun_allow_ip_ranges) )
        message($lang_common['No permission']);
} else {
    message($lang_common['Bad request']);
}