From 1f3311f5dd45784fe6802a2d150776dc75a6c591 Mon Sep 17 00:00:00 2001
From: Csaba Kos <csaba.kos@gmail.com>
Date: Sat, 22 Jul 2023 00:33:14 -0500
Subject: [PATCH] interfaces: allow multiple IP addresses in dhcp reject from;
 closes #6683

---
 src/etc/inc/interfaces.inc |  4 ++--
 src/www/interfaces.php     | 12 +++++++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/etc/inc/interfaces.inc b/src/etc/inc/interfaces.inc
index 9fc6fc297..1d865733f 100644
--- a/src/etc/inc/interfaces.inc
+++ b/src/etc/inc/interfaces.inc
@@ -3112,7 +3112,7 @@ EOD;
         $dhclientconf .= "  supersede interface-mtu 0;\n";
     }
 
-    if (is_ipaddrv4($wancfg['dhcprejectfrom'])) {
+    if (!empty($wancfg['dhcprejectfrom'])) {
         $dhclientconf .= "  reject {$wancfg['dhcprejectfrom']};\n";
     }
 
@@ -3223,7 +3223,7 @@ function DHCP_Config_File_Advanced($interface, $wancfg, $wanif)
     if (empty($wancfg['dhcphonourmtu'])) {
         $dhclientconf .= "\tsupersede interface-mtu 0;\n";
     }
-    if (is_ipaddrv4($wancfg['dhcprejectfrom'])) {
+    if (!empty($wancfg['dhcprejectfrom'])) {
         $dhclientconf .= "\treject {$wancfg['dhcprejectfrom']};\n";
     }
     if (isset($wancfg['dhcpvlanprio'])) {
diff --git a/src/www/interfaces.php b/src/www/interfaces.php
index 3288373c6..d7e865d4e 100644
--- a/src/www/interfaces.php
+++ b/src/www/interfaces.php
@@ -845,8 +845,14 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
         if (!empty($pconfig['alias-subnet']) && !is_numeric($pconfig['alias-subnet'])) {
             $input_errors[] = gettext("A valid alias subnet bit count must be specified.");
         }
-        if (!empty($pconfig['dhcprejectfrom']) && !is_ipaddrv4($pconfig['dhcprejectfrom'])) {
-            $input_errors[] = gettext("A valid alias IP address must be specified to reject DHCP Leases from.");
+
+        if (!empty($pconfig['dhcprejectfrom'])) {
+            foreach (explode(',', $pconfig['dhcprejectfrom']) as $addr) {
+                if (!is_ipaddrv4($addr)) {
+                    $input_errors[] = gettext('A valid alias IP address list must be specified to reject DHCP leases from.');
+                    break;
+                }
+            }
         }
 
         if ($pconfig['gateway'] != "none" || $pconfig['gatewayv6'] != "none") {
@@ -2289,7 +2295,7 @@ include("head.inc");
                           <td>
                             <input name="dhcprejectfrom" type="text" id="dhcprejectfrom" value="<?=htmlspecialchars($pconfig['dhcprejectfrom']);?>" />
                             <div class="hidden" data-for="help_for_dhcprejectfrom">
-                              <?=gettext("If there is a certain upstream DHCP server that should be ignored, place the IP address or subnet of the DHCP server to be ignored here."); ?>
+                              <?=gettext("If there are certain upstream DHCP servers that should be ignored, place the comma separated list of IP addresses of the DHCP servers to be ignored here."); ?>
                               <?=gettext("This is useful for rejecting leases from cable modems that offer private IPs when they lose upstream sync."); ?>
                             </div>
                           </td>