From 238c75989980bccc857a3f7a74e3451f36d212e5 Mon Sep 17 00:00:00 2001
From: Karl Fessel <karl.fessel@ovgu.de>
Date: Fri, 23 Jul 2021 17:46:14 +0200
Subject: [PATCH] dhcpv6_client: mrd calculation fixed for renew and rebind

mrd calculation for dhcp-renew was wrong this fixes it
and the logic for dhcp rebind mrd handling
    (try rebind if ther is mrd)
see issue  #16677
---
 sys/net/application_layer/dhcpv6/client.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/net/application_layer/dhcpv6/client.c b/sys/net/application_layer/dhcpv6/client.c
index 0e92501e36..319e843e7e 100644
--- a/sys/net/application_layer/dhcpv6/client.c
+++ b/sys/net/application_layer/dhcpv6/client.c
@@ -839,7 +839,7 @@ static void _request_renew_rebind(uint8_t type)
         case DHCPV6_RENEW:
             irt = DHCPV6_REN_TIMEOUT;
             mrt = DHCPV6_REN_MAX_RT;
-            mrd = rebind_time - t2;
+            mrd = rebind_time - _now_sec();
             break;
         case DHCPV6_REBIND: {
             irt = DHCPV6_REB_TIMEOUT;
@@ -858,7 +858,7 @@ static void _request_renew_rebind(uint8_t type)
                     mrd = valid_until;
                 }
             }
-            if (mrd > 0) {
+            if (mrd == 0) {
                 /* all leases already expired, don't try to rebind and
                  * solicit immediately */
                 _post_solicit_servers();