From bbbed94a9392ec081cedeb9fa5115f4671aabdaf Mon Sep 17 00:00:00 2001
From: Franco Fichtner <franco@opnsense.org>
Date: Tue, 21 Mar 2023 21:18:53 +0100
Subject: [PATCH] Revert "dhcp: radvd HUP brings back the infamous "can't join
 ipv6-allrouters" error"

This reverts commit 38049e4ea8b342b6c5f7705e69c2e0034dc67914.
This can be fixed in radvd.
---
 src/etc/inc/plugins.inc.d/dhcpd.inc | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/etc/inc/plugins.inc.d/dhcpd.inc b/src/etc/inc/plugins.inc.d/dhcpd.inc
index ec83ba6d3..4389b8299 100644
--- a/src/etc/inc/plugins.inc.d/dhcpd.inc
+++ b/src/etc/inc/plugins.inc.d/dhcpd.inc
@@ -517,11 +517,15 @@ function dhcpd_radvd_configure($verbose = false, $blacklist = [])
 
     file_put_contents('/var/etc/radvd.conf', $radvdconf);
 
-    killbypid('/var/run/radvd.pid');
-
     if (count($radvdifs)) {
-        /* only start in valid configuration for legacy condition */
-        mwexec('/usr/local/sbin/radvd -p /var/run/radvd.pid -C /var/etc/radvd.conf -m syslog');
+        if (isvalidpid('/var/run/radvd.pid')) {
+            killbypid('/var/run/radvd.pid', 'HUP');
+        } else {
+            mwexec('/usr/local/sbin/radvd -p /var/run/radvd.pid -C /var/etc/radvd.conf -m syslog');
+        }
+    } else {
+        /* stop on invalid configuration for legacy condition above */
+        killbypid('/var/run/radvd.pid');
     }
 
     service_log("done.\n", $verbose);