php script to update multiple dyndns endpoints with one url

fritzbox-dyndns-update-multiple.php

<?php

/**
 * Quick and dirty script to update ipv4 and ipv6 records simultaneously by the fritz box ddns function.
 * afraid.org offered only one-record-per-url so this takes the fritzbox input and makes two separate calls to afraid.org
 * Fritzbox settings should be:
 * url = point to this script. attach parameters auth_key, ipv4 and ipv6. Lookup the fritzbox help to find the parameter placeholder, should look like
 * http://path-to-this-script.com/script.php?auth_key=<username>&ipv4=<ipaddr>&ipv6=<ip6addr>
 * domain: your domain
 * username: yourawesomekey below
 * password anything you want, doesn't matter
 */

$auth_key = 'yourawesomekey_privately_defined'; //prevent anyone who knows the simple script url to update your ip adresses

if ($_GET['auth_key'] == $auth_key) {
    
    $ipv4 = $_GET['ipv4'];
    $ipv6 = $_GET['ipv6'];
    
    
    function curl_fetch($url)
    {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        $data  = curl_exec($ch);
        $error = curl_error($ch);
        curl_close($ch);
        
        if (!empty($error)) {
            echo $error;
        }
        return $data;
    }
    
    //Make sure to enter the correct update URL (mind the correct token!)
    $ipv4_url = 'http://freedns.afraid.org/dynamic/update.php?<token4>&address=' . $ipv4;
    echo curl_fetch($ipv4_url);
    //Make sure to enter the correct update URL (mind the correct token!)    
    $ipv6_url = 'http://freedns.afraid.org/dynamic/update.php?<token6>&address=' . $ipv6;
    echo curl_fetch($ipv6_url);
    
}