From d048a319df412ee7966a898caed2ac93f0eae1b1 Mon Sep 17 00:00:00 2001
From: Martin Willi <martin@revosec.ch>
Date: Thu, 7 Nov 2013 09:21:02 +0100
Subject: [PATCH] ike: Restart inactivity counter after doing a CHILD_SA rekey

When doing a rekey for a CHILD_SA, the use counters get reset. An inactivity
job is queued for a time unrelated to the rekey time, so it might happen
that the inactivity job gets executed just after rekeying. If this happens,
inactivity is detected even if we had traffic on the rekeyed CHILD_SA just
before rekeying.

This change implies that inactivity checks can't handle inactivity timeouts
for rekeyed CHILD_SAs, and therefore requires that inactivity timeout is shorter
than the rekey time to have any effect.
---
 man/ipsec.conf.5.in                            | 4 +++-
 src/libcharon/processing/jobs/inactivity_job.c | 5 +++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/man/ipsec.conf.5.in b/man/ipsec.conf.5.in
index 92be67000..a0be75536 100644
--- a/man/ipsec.conf.5.in
+++ b/man/ipsec.conf.5.in
@@ -386,7 +386,9 @@ retransmission timeout applies, as every exchange is used to detect dead peers.
 .TP
 .BR inactivity " = <time>"
 defines the timeout interval, after which a CHILD_SA is closed if it did
-not send or receive any traffic.
+not send or receive any traffic. The inactivity counter is reset during CHILD_SA
+rekeying. This means that the inactivity timeout must be smaller than the
+rekeying interval to have any effect.
 .TP
 .BR eap_identity " = <id>"
 defines the identity the client uses to reply to an EAP Identity request.
diff --git a/src/libcharon/processing/jobs/inactivity_job.c b/src/libcharon/processing/jobs/inactivity_job.c
index 9ab69b417..197733979 100644
--- a/src/libcharon/processing/jobs/inactivity_job.c
+++ b/src/libcharon/processing/jobs/inactivity_job.c
@@ -73,12 +73,13 @@ METHOD(job_t, execute, job_requeue_t,
 		{
 			if (child_sa->get_reqid(child_sa) == this->reqid)
 			{
-				time_t in, out, diff;
+				time_t in, out, install, diff;
 
 				child_sa->get_usestats(child_sa, TRUE, &in, NULL, NULL);
 				child_sa->get_usestats(child_sa, FALSE, &out, NULL, NULL);
+				install = child_sa->get_installtime(child_sa);
 
-				diff = time_monotonic(NULL) - max(in, out);
+				diff = time_monotonic(NULL) - max(max(in, out), install);
 
 				if (diff >= this->timeout)
 				{