From 894ee65675ee846bd0c7d98e75b261cf5d6b35cc Mon Sep 17 00:00:00 2001
From: Christian Hesse <mail@eworm.de>
Date: Fri, 5 Jul 2019 16:09:49 +0200
Subject: [PATCH] ipv6-update: give hint about mis-usage

---
 ipv6-update | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/ipv6-update b/ipv6-update
index 1b52efc..869daf3 100644
--- a/ipv6-update
+++ b/ipv6-update
@@ -6,6 +6,11 @@
 
 :local PdPrefix $"pd-prefix";
 
+:if ([ :typeof $PdPrefix ] = "nothing") do={
+  :log error "This script is supposed to run from ipv6 dhcp-client.";
+  :error "Error: See log for details.";
+}
+
 :local Pool [ / ipv6 pool get [ find where prefix=$PdPrefix ] name ];
 :local AddrList [ / ipv6 firewall address-list find where comment=("ipv6-pool-" . $Pool) ];
 :local OldPrefix [ / ipv6 firewall address-list get $AddrList address ];