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 5936a53905ecddd5f5f64876c5ba2b3a2057c4b4..22da2076065eb2c523bf442f8b6a303c6b4dc341 100644 (file)
--- 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;