Disable WAN Interface on CARP Backup

10-wancarp

#!/usr/local/bin/php
<?php

require_once("config.inc");
require_once("interfaces.inc");
require_once("util.inc");

$subsystem = !empty($argv[1]) ? $argv[1] : '';
$type = !empty($argv[2]) ? $argv[2] : '';

if ($type != 'MASTER' && $type != 'BACKUP' && $type != 'INIT') {
    log_error("Carp '$type' event unknown from source '{$subsystem}'");
    exit(1);
}

if (!strstr($subsystem, '@')) {
    log_error("Carp '$type' event triggered from wrong source '{$subsystem}'");
    exit(1);
}

$ifkey = 'wan';
$lan_vip = 'YOUR_CARP_LAN_VIP';

if ($type === "MASTER") {
    log_error("Enable interface '$ifkey' due CARP event '$type'");

    $config['interfaces'][$ifkey]['enable'] = '1';
    write_config("Enable interface '$ifkey' due CARP event '$type'", false);
    interface_configure(false, $ifkey, false, false);
} else if ($type === "BACKUP") {
    log_error("Disable interface '$ifkey' due CARP event '$type'");

    unset($config['interfaces'][$ifkey]['enable']);
    write_config("Disable interface '$ifkey' due CARP event '$type'", false);
    interface_configure(false, $ifkey, false, false);

    exec('/sbin/route del default >&1', $ifc, $ret);
    exec('/sbin/route add default ' . $lan_vip . ' >&1', $ifc, $ret);
}
?>

I have a dual-wan setup, and my old scripts are no longer working well either. Would it suffice to simply loop through an array of WAN interfaces? It doesn't seem like I should be calling the exec() lines for each interface, right?