(legacy) it feels kind of duplicate, but to avoid too much changes to how it...

(legacy) it feels kind of duplicate, but to avoid too much changes to how it works now let's keep the behavior approx. the same.

src/etc/inc/auth.inc

@@ -148,20 +148,8 @@ if(function_exists("display_error_form") && !isset($config['system']['webgui']['
 					}
 
 			if(!$found_host) {
-				$interface_list_ips = get_configured_ip_addresses();
-				foreach($interface_list_ips as $ilips) {
-					if(strcasecmp($referrer_host, $ilips) == 0) {
-						$found_host = true;
-						break;
-					}
-				}
-				$interface_list_ipv6s = get_configured_ipv6_addresses();
-				foreach($interface_list_ipv6s as $ilipv6s) {
-					if(strcasecmp($referrer_host, $ilipv6s) == 0) {
-						$found_host = true;
-						break;
-					}
-				}
+				$found_host = isAuthLocalIP($referrer_host) ;
+
 				if($referrer_host == "127.0.0.1" || $referrer_host == "localhost") {
 					// allow SSH port forwarded connections and links from localhost
 					$found_host = true;
@@ -188,6 +176,37 @@ unset($security_passed);
 $groupindex = index_groups();
 $userindex = index_users();
 
+/**
+ * check if $http_host is a local configured ip address
+ */
+function isAuthLocalIP($http_host) {
+    global $config;
+    $local_ip = false;
+    if (isset($config['interfaces'])) {
+	foreach($config['interfaces'] as $if => $ifdetail) {
+		if (isset($ifdetail['enable'])) {
+			if (isset($ifdetail['ipaddr']) && $ifdetail['ipaddr'] == $http_host) {
+				$local_ip = true;
+			} elseif (isset($ifdetail['ipaddr6']) && $ifdetail['ipaddr6'] == $http_host) {
+				$local_ip = true;
+			}
+		}
+	}
+    }
+
+    if (isset($config['virtualip'])) {
+        if ($config['virtualip']['vip']) {
+            foreach ($config['virtualip']['vip'] as $vip) {
+                if ($vip['subnet'] == $http_host) {
+                    $local_ip = true;
+                }
+            }
+        }
+    }
+
+    return $local_ip;
+}
+
 function index_groups()
 {
 	global $config, $groupindex;

src/etc/inc/authgui.inc

@@ -31,7 +31,6 @@
 */
 
 require_once("auth.inc");
-require_once("functions.inc");
 
 // provided via legacy_bindings.inc 
 global $priv_list;
@@ -408,27 +407,8 @@ function display_login_form()
 
     // fix, local ip check was previously done using "filter_generate_optcfg_array" which basically includes alomst everything here.
     // this should do the trick as well.
-    if (isset($config['interfaces'])) {
-	foreach($config['interfaces'] as $if => $ifdetail) {
-		if (isset($ifdetail['enable'])) {
-			if (isset($ifdetail['ipaddr']) && $ifdetail['ipaddr'] == $http_host) {
-				$local_ip = true;
-			} elseif (isset($ifdetail['ipaddr6']) && $ifdetail['ipaddr6'] == $http_host) {
-				$local_ip = true;
-			}
-		}
-	}
-    }
+    $local_ip = isAuthLocalIP($http_host);
 
-    if (isset($config['virtualip'])) {
-        if ($config['virtualip']['vip']) {
-            foreach ($config['virtualip']['vip'] as $vip) {
-                if ($vip['subnet'] == $http_host) {
-                    $local_ip = true;
-                }
-            }
-        }
-    }
     if (isset($config['openvpn']['openvpn-server'])) {
         foreach ($config['openvpn']['openvpn-server'] as $ovpns) {
             if (is_ipaddrv4($http_host) && !empty($ovpns['tunnel_network']) && ip_in_subnet($http_host, $ovpns['tunnel_network'])) {