lagg interfaces, restructure interface_lagg_configure() and add mtu option,...

lagg interfaces, restructure interface_lagg_configure() and add mtu option, for https://github.com/opnsense/core/issues/1709

src/etc/inc/interfaces.inc

@@ -704,35 +704,48 @@ function interface_lagg_configure(&$lagg)
     if (!count($members)) {
         return -1;
     }
+    $interface_stats = legacy_interfaces_details();
 
-    if (file_exists("/var/run/booting") || !(empty($lagg['laggif']))) {
-        legacy_interface_destroy($lagg['laggif']);
-        legacy_interface_create($lagg['laggif']);
+    if (!empty($lagg['laggif'])) {
         $laggif = $lagg['laggif'];
+        if (empty($interface_stats[$laggif])) {
+            legacy_interface_create($lagg['laggif']);
+        } else {
+            // Already configured, detach child interfaces before attempting to configure.
+            // Prevents vlans to loose parent.
+            if (!empty($interface_stats[$laggif]['laggport'])) {
+                foreach ($interface_stats[$laggif]['laggport'] as $laggport) {
+                    mwexec("/sbin/ifconfig {$laggif} -laggport {$laggport}");
+                }
+            }
+        }
     } else {
         $laggif = legacy_interface_create('lagg');
     }
 
-    /* Calculate smaller mtu and enforce it */
+
+    // determine mtu value to use, either the provided one for the lagg or smallest of it's children
     $mtu = null;
+    if (!empty($lagg['mtu'])) {
+        // mtu provided for lagg
+        $mtu = $lagg['mtu'];
+    } else {
+        // min() mtu of children
         foreach ($members as $member) {
-        $opts = legacy_interface_stats($member);
-        if (!empty($opts['mtu']) && ($mtu == null || $opts['mtu'] < $mtu)) {
-            $mtu = $opts['mtu'];
+            if (!empty($interface_stats[$member]['mtu']) && ($mtu == null || $interface_stats[$member]['mtu'] < $mtu)) {
+                $mtu = $interface_stats[$member]['mtu'];
             }
         }
-
-    $checklist = get_interface_list();
-    foreach ($members as $member) {
-        if (!array_key_exists($member, $checklist)) {
-            continue;
     }
 
+    foreach ($members as $member) {
+        if (!empty($interface_stats[$member])) {
             legacy_interface_mtu($member, $mtu);
             configure_interface_hardware($member);
             interfaces_bring_up($member);
             mwexec("/sbin/ifconfig {$laggif} laggport {$member}");
         }
+    }
 
     mwexec("/sbin/ifconfig {$laggif} laggproto " . escapeshellarg($lagg['proto']));
     if (!empty($lagg['lacp_fast_timeout'])) {

src/www/interfaces_lagg_edit.php

@@ -93,6 +93,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
     $pconfig['proto'] = isset($a_laggs[$id]['proto']) ? $a_laggs[$id]['proto'] : null;
     $pconfig['descr'] = isset($a_laggs[$id]['descr']) ? $a_laggs[$id]['descr'] : null;
     $pconfig['lacp_fast_timeout'] = !empty($a_laggs[$id]['lacp_fast_timeout']);
+    $pconfig['mtu'] = isset($a_laggs[$id]['mtu']) ? $a_laggs[$id]['mtu'] : null;
 } elseif ($_SERVER['REQUEST_METHOD'] === 'POST') {
     // validate and save form data
     if (!empty($a_laggs[$_POST['id']])) {
@@ -118,6 +119,9 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
     if (!in_array($pconfig['proto'], $laggprotos)) {
         $input_errors[] = gettext("Protocol supplied is invalid");
     }
+    if (!empty($pconfig['mtu']) && ($pconfig['mtu'] < 576 || $pconfig['mtu'] > 9000)) {
+        $input_errors[] = gettext("The MTU must be greater than 576 bytes and less than 9000.");
+    }
 
     if (count($input_errors) == 0) {
         $lagg = array();
@@ -125,6 +129,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
         $lagg['descr'] = $pconfig['descr'];
         $lagg['laggif'] = $pconfig['laggif'];
         $lagg['proto'] = $pconfig['proto'];
+        $lagg['mtu'] = $pconfig['mtu'];
         $lagg['lacp_fast_timeout'] = !empty($pconfig['lacp_fast_timeout']);
         if (isset($id)) {
             $lagg['laggif'] = $a_laggs[$id]['laggif'];
@@ -282,6 +287,15 @@ legacy_html_escape_form_data($pconfig);
                       </div>
                     </td>
                   </tr>
+                  <tr>
+                    <td><a id="help_for_mtu" href="#" class="showhelp"><i class="fa fa-info-circle"></i></a> <?=gettext("MTU"); ?></td>
+                    <td>
+                      <input name="mtu" id="mtu" type="text" value="<?=$pconfig['mtu'];?>" />
+                      <div class="hidden" for="help_for_mtu">
+                        <?= gettext("If you leave this field blank, the smallest mtu of this laggs children will be used.");?>
+                      </div>
+                    </td>
+                  </tr>
                   <tr>
                     <td width="22%" valign="top">&nbsp;</td>
                     <td width="78%">