ddns.php: only issue updates for zones that really exist

1 files changed, 10 insertions, 1 deletions

diff --git a/ddns.php b/ddns.php
index c3694b9..f3becb4 100644
--- a/ddns.php
+++ b/ddns.php
@@ -15,8 +15,15 @@
 
   function reverse_entry($addr) {
     $addrTeile = explode('.', $addr);
+    $lp = array_pop($addrTeile);
+    $subNet = implode('.', $addrTeile);
+    array_push($addrTeile, $lp);
     array_reverse($addrTeile);
-    return implode('.',$addrTeile).'.in-addr.arpa.';
+    if (($subNet == '10.0.2') ||
+        ($subNet == '192.168.0') ||
+        ($subNet == '192.168.1'))
+      return implode('.',$addrTeile).'.in-addr.arpa.';
+    return NULL;
   };
 
   function reverse_zone($addr) {
@@ -125,6 +132,8 @@
   foreach ($ips as $i => $ip) {
     if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
       $reverse_entry = reverse_entry($ip);
+      if (!$reverse_entry)
+        continue;
       $updateCommand .=
         "zone ".reverse_zone($ip)."\n";
       // delete old record if existing