From: Frédéric Lécaille <flecaille@haproxy.com>
Date: Tue, 4 Apr 2023 08:46:54 +0000 (+0200)
Subject: BUG/MINOR: quic: Unexpected connection closures upon idle timer task execution
X-Git-Tag: v2.8-dev7~109
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=12eca3a727b3278cf456b0f62da9d91c4b9c2a27;p=thirdparty%2Fhaproxy.git

BUG/MINOR: quic: Unexpected connection closures upon idle timer task execution

This bug arrived with this commit:

      MEDIUM: quic: Ack delay implementation

It is possible that the idle timer task was already in the run queue when its
->expire field was updated calling qc_idle_timer_do_rearm(). To prevent this
task from running in this condition, one must check its ->expire field value
with this condition to run the task if its timer has really expired:

	!tick_is_expired(t->expire, now_ms)

Furthermore, as this task may be directly woken up with a call to task_wakeup()
all, for instance by qc_kill_conn() to kill the connection, one must check this
task has really been woken up when it was in the wait queue and not by a direct
call to task_wakeup() thanks to this test:

	(state & TASK_WOKEN_ANY) == TASK_WOKEN_TIMER

Again, when this condition is not fulfilled, the task must be run.

Must be backported where the commit mentionned above was backported.
---

diff --git a/src/quic_conn.c b/src/quic_conn.c
index 5936a53905..22da207606 100644
--- a/src/quic_conn.c
+++ b/src/quic_conn.c
@@ -5681,6 +5681,9 @@ struct task *qc_idle_timer_task(struct task *t, void *ctx, unsigned int state)
 
 	TRACE_ENTER(QUIC_EV_CONN_IDLE_TIMER, qc);
 
+	if ((state & TASK_WOKEN_ANY) == TASK_WOKEN_TIMER && !tick_is_expired(t->expire, now_ms))
+		goto requeue;
+
 	if (tick_is_expired(qc->ack_expire, now_ms)) {
 		TRACE_PROTO("ack timer expired", QUIC_EV_CONN_SSLALERT, qc);
 		qc->ack_expire = TICK_ETERNITY;