From eada2bf5a1836461b7854bb57337b62a1f43deda Mon Sep 17 00:00:00 2001
From: Franco Fichtner <franco@opnsense.org>
Date: Wed, 24 Oct 2018 09:23:13 +0000
Subject: [PATCH] interfaces: override link-local tracking router address if
 needed

PR: https://forum.opnsense.org/index.php?topic=10034.0
---
 src/etc/inc/interfaces.inc |  4 +++-
 src/www/interfaces.php     | 16 +++++++++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/etc/inc/interfaces.inc b/src/etc/inc/interfaces.inc
index 7339c294f..677bcd537 100644
--- a/src/etc/inc/interfaces.inc
+++ b/src/etc/inc/interfaces.inc
@@ -2577,6 +2577,8 @@ function interface_track6_configure($interface = 'lan', $lancfg, $linkupevent =
         return;
     }
 
+    $lladdr = !empty($lancfg['track6-lladdr']) ? $lancfg['track6-lladdr'] : 'fe80::1:1';
+
     $realif = get_real_interface($interface, 'inet6');
 
     /* always configure a fixed link-local on the track6 interfaces */
@@ -2584,7 +2586,7 @@ function interface_track6_configure($interface = 'lan', $lancfg, $linkupevent =
     if (!empty($linklocal)) {
         mwexecf('/sbin/ifconfig %s inet6 %s delete', array($realif, $linklocal));
     }
-    mwexecf('/sbin/ifconfig %s inet6 %s', array($realif, "fe80::1:1%{$realif}"));
+    mwexecf('/sbin/ifconfig %s inet6 %s', array($realif, "{$lladdr}%{$realif}"));
 
     switch ($trackcfg['ipaddrv6']) {
         case '6to4':
diff --git a/src/www/interfaces.php b/src/www/interfaces.php
index a6daf4b4b..b707967b9 100644
--- a/src/www/interfaces.php
+++ b/src/www/interfaces.php
@@ -426,6 +426,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
         'subnet',
         'subnetv6',
         'track6-interface',
+        'track6-lladdr',
         'track6-prefix-id',
         'rfc3118_isp',
         'rfc3118_username',
@@ -445,7 +446,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
     $pconfig['dhcp6usev4iface'] = isset($a_interfaces[$if]['dhcp6usev4iface']);
     $pconfig['dhcp6norelease'] = isset($a_interfaces[$if]['dhcp6norelease']);
     $pconfig['adv_dhcp6_debug'] = isset($a_interfaces[$if]['adv_dhcp6_debug']);
-    $pconfig['track6-prefix-id--hex'] = sprintf("%x", empty($pconfig['track6-prefix-id']) ? 0 :$pconfig['track6-prefix-id']);
+    $pconfig['track6-prefix-id--hex'] = sprintf("%x", empty($pconfig['track6-prefix-id']) ? 0 : $pconfig['track6-prefix-id']);
     $pconfig['dhcpd6track6allowoverride'] = isset($a_interfaces[$if]['dhcpd6track6allowoverride']);
 
     /*
@@ -794,6 +795,9 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
                     }
                     /* XXX should also check for duplicate delegation in peer trackers */
                 }
+                if (!empty($pconfig['track6-lladdr']) && (!is_ipaddrv6($pconfig['track6-lladdr']) || !is_linklocal($pconfig['track6-lladdr']))) {
+                    $input_errors[] = gettext('A valid link-local tracking router address must be specified.');
+                }
                 break;
         }
 
@@ -1222,6 +1226,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
                 case 'track6':
                     $new_config['ipaddrv6'] = 'track6';
                     $new_config['track6-interface'] = $pconfig['track6-interface'];
+                    $new_config['track6-lladdr'] = $pconfig['track6-lladdr'];
                     $new_config['track6-prefix-id'] = 0;
                     if (ctype_xdigit($pconfig['track6-prefix-id--hex'])) {
                         $new_config['track6-prefix-id'] = intval($pconfig['track6-prefix-id--hex'], 16);
@@ -3022,6 +3027,15 @@ include("head.inc");
                             </div>
                           </td>
                         </tr>
+                        <tr>
+                          <td><a id="help_for_track6-lladdr" href="#" class="showhelp"><i class="fa fa-info-circle"></i></a> <?= gettext('Link-local router address') ?></td>
+                          <td>
+                            <input name="track6-lladdr" type="text" id="track6-lladdr" value="<?= html_safe($pconfig['track6-lladdr']) ?>" placeholder="fe80::1:1"/>
+                            <div class="hidden" data-for="help_for_track6-lladdr">
+                              <?= gettext('The value in this field is the link-local router address. Optionally overrides the recommended use of fe80::1:1.') ?>
+                            </div>
+                          </td>
+                        </tr>
                         <tr>
                           <td><a id="help_for_dhcpd6_opt" href="#" class="showhelp"><i class="fa fa-info-circle"></i></a> <?= gettext('Manual configuration') ?></td>
                           <td>