bugfix:cancel rebind6 timer after ipv6 expire

(cherry picked from commit 9a893a95bab101c995408e9cdc5d72b5276fdf5c)

bugfix-cancel-rebind6-timer-after-ipv6-expire.patch

@@ -0,0 +1,54 @@
+From 6fced85ebcd9563ceb78675d0f4ff3e3d0eea90b Mon Sep 17 00:00:00 2001
+From: huyizhen <huyizhen2@huawei.com>
+Date: Thu, 24 Oct 2024 21:36:06 +0800
+Subject: huawei-cancel-rebind6-timer-after-ipv6-expire
+
+Solve below question:
+Oct 23 16:38:04 localhost dhclient[141133]: PRC: Address 6636::3c depreferred.
+Oct 23 16:38:04 localhost dhclient[141133]: XMT: Rebind on enp4s0, interval 00ms.
+Oct 23 16:38:04 localhost dhclient[141133]: Impossible condition at dhc6.c:279.
+Oct 23 16:38:04 localhost dhclient[141133]:
+Oct 23 16:38:04 localhost dhclient[141133]: If you think you have received this message due to a bug rather
+Oct 23 16:38:04 localhost dhclient[141133]: than a configuration issue please read the section on submitting
+Oct 23 16:38:04 localhost dhclient[141133]: bugs on either our web page at www.isc.org or in the README file
+Oct 23 16:38:04 localhost dhclient[141133]: before submitting a bug. These pages explain the proper
+Oct 23 16:38:04 localhost dhclient[141133]: process and the information we find helpful for debugging.
+Oct 23 16:38:04 localhost dhclient[141133]:
+Oct 23 16:38:04 localhost dhclient[141133]: exiting.
+
+The reason is:
+1. After the REBIND message is retransmitted for the second time, the REBIND timer checks whether the REBIND message
+is received 5 seconds later and sets the RT field to 0. (Because the 5s timer expires when the timer expires, no next
+retransmission will occur.)
+2. After 5s, the DEPREFER timer is triggered first. The DEPREFER timer considers that the REBIND timer expires and set
+MRD field to 0, but the previously set REBIND timer is not canceled.
+3. The REBIND timer is triggered immediately. Because the MRD is set to 0, the retransmission timer considers that the
+maximum retransmission duration is not limited and attempts to continue the retransmission.
+4. During the retransmission process, the RT value is 0 (retransmission is performed after 0s), and the process exits.
+As a result, the DHCP6 function becomes abnormal.
+
+Solution:
+Cencle REBIND timer when DEPREFER timer considers that the REBIND timer expires.
+
+---
+ client/dhc6.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/client/dhc6.c b/client/dhc6.c
+index 88fd07d..2dbea60 100644
+--- a/client/dhc6.c
++++ b/client/dhc6.c
+@@ -4656,6 +4656,10 @@ dhc6_check_times(struct client_state *client)
+ 		 * depreffed an address.
+ 		 */
+ 		client->MRD = hi_expire - cur_time;
++		/* Rebind expired, cancel rebind(do_refresh6) timer. */
++		if (client->MRD == 0) {
++			cancel_timeout(do_refresh6, client);
++		}
+ 		break;
+ 
+ 	      default:
+-- 
+2.33.0
+

dhcp.spec

@@ -3,7 +3,7 @@
 
 Name:      dhcp
 Version:   4.4.3
-Release:   7
+Release:   8
 Summary:   Dynamic host configuration protocol software
 #Please don't change the epoch on this package
 Epoch:     12
@@ -62,6 +62,7 @@ Patch43: backport-CVE-2022-38177.patch
 Patch44: backport-CVE-2022-38178.patch
 Patch45: IAID-is-output-has-hexe-if-it-contains-or.patch
 Patch46: support-for-building-with-clang.patch
+Patch47: bugfix-cancel-rebind6-timer-after-ipv6-expire.patch
 
 BuildRequires: gcc autoconf automake libtool openldap-devel krb5-devel libcap-ng-devel
 BuildRequires: systemd systemd-devel
@@ -310,6 +311,12 @@ exit 0
 %{_mandir}/man3/omapi.3.gz
 
 %changelog
+* Wed Nov 5 huyizhen <huyizhen2@huawei.com> - 12:4.4.3-8
+- Type:bugfix
+- ID:NA
+- SUG:restart
+- DESC:cancel rebind6 timer after ipv6 expire
+
 * Thu Mar 20 cf-zhao <zhaochuanfeng@huawei.com> - 12:4.4.3-7
 - Type:enhancement
 - ID:NA