// init $config['virtualip']['vip']
if (!isset($config['virtualip']['vip']) || !is_array($config['virtualip']['vip'])) {
    $config['virtualip']['vip'] = array();
}
$a_vip =& $config['virtualip']['vip'];
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    if (!empty($_POST['carp_maintenancemode'])) {
        interfaces_carp_set_maintenancemode(!isset($config["virtualip_carp_maintenancemode"]));
    } elseif (!empty($_POST['disablecarp'])) {
        if (get_single_sysctl('net.inet.carp.allow') > 0) {
            $carp_counter = 0;
            set_single_sysctl('net.inet.carp.allow', '0');
            foreach ($a_vip as $vip) {
                switch ($vip['mode']) {
                    case "carp":
                        interface_vip_bring_down($vip);
                        $carp_counter++;
                        sleep(1);
                        break;
                }
            }
            $savemsg = sprintf(gettext("%s IPs have been disabled. Please note that disabling does not survive a reboot."), $carp_counter);
        } else {
            $savemsg = gettext("CARP has been enabled.");
            foreach ($a_vip as $vip) {
                switch ($vip['mode']) {
                    case "carp":
                        interface_carp_configure($vip);
                        sleep(1);
                        break;
                }

            if (session_status() == PHP_SESSION_NONE) {
                session_start();
            }
            $user = getUserEntry($_SESSION['Username']);
            if (is_array($user) && userHasPrivilege($user, "user-config-readonly")) {
                header("Location: firewall_virtual_ip.php");
                exit;
            }
            session_write_close();
            // Special case since every proxyarp vip is handled by the same daemon.
            if ($a_vip[$_GET['id']]['mode'] == "proxyarp") {
                $viface = $a_vip[$_GET['id']]['interface'];
                unset($a_vip[$_GET['id']]);
                interface_proxyarp_configure($viface);
            } else {
                interface_vip_bring_down($a_vip[$_GET['id']]);
                unset($a_vip[$_GET['id']]);
            }
            if (count($config['virtualip']['vip']) == 0) {
                unset($config['virtualip']['vip']);
            }
            write_config();
            header("Location: firewall_virtual_ip.php");
            exit;
        }
    }
} else {
    if ($_GET['changes'] == "mods" && is_numericint($_GET['id'])) {
        $id = $_GET['id'];
    }
}

/**
 * delete virtual ip
 */
function deleteVIPEntry($id)
{
    global $config;
    $input_errors = array();
    $a_vip =& $config['virtualip']['vip'];
    /* make sure no inbound NAT mappings reference this entry */
    if (isset($config['nat']['rule'])) {
        foreach ($config['nat']['rule'] as $rule) {
            if (!empty($rule['destination']['address'])) {
                if ($rule['destination']['address'] == $a_vip[$id]['subnet']) {
                    $input_errors[] = gettext("This entry cannot be deleted because it is still referenced by at least one NAT mapping.");
                    break;
                }
            }
        }
    }
    if (is_ipaddrv6($a_vip[$id]['subnet'])) {
        $is_ipv6 = true;
        $subnet = gen_subnetv6($a_vip[$id]['subnet'], $a_vip[$id]['subnet_bits']);
        $if_subnet_bits = get_interface_subnetv6($a_vip[$id]['interface']);
        $if_subnet = gen_subnetv6(get_interface_ipv6($a_vip[$id]['interface']), $if_subnet_bits);
    } else {
        $is_ipv6 = false;
        $subnet = gen_subnet($a_vip[$id]['subnet'], $a_vip[$id]['subnet_bits']);
        $if_subnet_bits = get_interface_subnet($a_vip[$id]['interface']);
        $if_subnet = gen_subnet(get_interface_ip($a_vip[$id]['interface']), $if_subnet_bits);
    }
    $subnet .= "/" . $a_vip[$id]['subnet_bits'];
    $if_subnet .= "/" . $if_subnet_bits;
    if (isset($config['gateways']['gateway_item'])) {
        foreach ($config['gateways']['gateway_item'] as $gateway) {
            if ($a_vip[$id]['interface'] != $gateway['interface']) {
                continue;
            }
            if ($is_ipv6 && $gateway['ipprotocol'] == 'inet') {
                continue;
            }
            if (!$is_ipv6 && $gateway['ipprotocol'] == 'inet6') {
                continue;
            }
            if (ip_in_subnet($gateway['gateway'], $if_subnet)) {
                continue;
            }
            if (ip_in_subnet($gateway['gateway'], $subnet)) {
                $input_errors[] = gettext("This entry cannot be deleted because it is still referenced by at least one Gateway.");
                break;
            }
        }
    }
    if ($a_vip[$id]['mode'] == "ipalias") {
        $subnet = gen_subnet($a_vip[$id]['subnet'], $a_vip[$id]['subnet_bits']) . "/" . $a_vip[$id]['subnet_bits'];
        $found_if = false;
        $found_carp = false;
        $found_other_alias = false;
        if ($subnet == $if_subnet) {
            $found_if = true;
        }
        $vipiface = $a_vip[$id]['interface'];
        foreach ($a_vip as $vip_id => $vip) {
            if ($vip_id != $id) {
                if ($vip['interface'] == $vipiface && ip_in_subnet($vip['subnet'], $subnet)) {
                    if ($vip['mode'] == "carp") {
                        $found_carp = true;
                    } else {
                        if ($vip['mode'] == "ipalias") {
                            $found_other_alias = true;
                        }
                    }
                }
            }
        }
        if ($found_carp === true && $found_other_alias === false && $found_if === false) {
            $input_errors[] = gettext("This entry cannot be deleted because it is still referenced by a CARP IP with the description") . " {$vip['descr']}.";
        }
    }
    if (count($input_errors) == 0) {
        // Special case since every proxyarp vip is handled by the same daemon.
        if ($a_vip[$id]['mode'] == "proxyarp") {
            $viface = $a_vip[$id]['interface'];
            unset($a_vip[$id]);
            interface_proxyarp_configure($viface);
        } else {
            interface_vip_bring_down($a_vip[$id]);
            unset($a_vip[$id]);
        }
        if (count($config['virtualip']['vip']) == 0) {
            unset($config['virtualip']['vip']);
        }
    }
    return $input_errors;
}