BUG/MEDIUM: bwlim: Be sure to never set the analyze expiration date in past
Every time a bandwidth limitation is evaluated on a channel, the analyze
expiration date is renewed, mainly based on the internal bandwidth
limitation filter expiration date. However, when the filter is called while
there is no data to filter, we skip all limitation computations to jump at
the end of the function. At this stage, the analyze expiration date is
renewed before exiting. But here the internal expiration date may be expired
and not reset.
To sum up, it is possible to set the analyze expiration date of a channel in
the past. It is unexpected and this could lead to a loop in process_stream.
To fix the issue, we just now take care to reset the internal expiration
date, if needed, before exiting.
This patch should fix the issue #2634. It must be backported as far as 2.8.
(cherry picked from commit 2cb5b7dca688e59146256833153ad700302004ba)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 9613cd06a5a8d2dd89d55b2c13ac311b7a25f5c1)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit ab5a6cce24ba7598f2d224cf582694ba3636cb2a)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/src/flt_bwlim.c b/src/flt_bwlim.c
index 27db231..82aa44b 100644
--- a/src/flt_bwlim.c
+++ b/src/flt_bwlim.c
@@ -85,10 +85,13 @@
/* Don't forward anything if there is nothing to forward or the waiting
* time is not expired
*/
- if (!len || (tick_isset(st->exp) && !tick_is_expired(st->exp, now_ms)))
+ if (tick_isset(st->exp) && !tick_is_expired(st->exp, now_ms))
goto end;
st->exp = TICK_ETERNITY;
+ if (!len)
+ goto end;
+
ret = len;
if (conf->flags & BWLIM_FL_SHARED) {
void *ptr;
@@ -177,6 +180,7 @@
end:
chn->analyse_exp = tick_first((tick_is_expired(chn->analyse_exp, now_ms) ? TICK_ETERNITY : chn->analyse_exp),
st->exp);
+ BUG_ON(tick_is_expired(chn->analyse_exp, now_ms));
return ret;
}