From: Frederic Lecaille <flecaille@haproxy.com>
Date: Fri, 13 Dec 2024 10:56:49 +0000 (+0100)
Subject: BUG/MINOR: quic: too permissive exit condition for high loss detection in Startup... 
X-Git-Tag: v3.2-dev2~80
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=178109f608ae1e446d9ea898bf5c83e4e8313bb5;p=thirdparty%2Fhaproxy.git

BUG/MINOR: quic: too permissive exit condition for high loss detection in Startup (BBR)

This bug fixes the 3rd condition used by bbr_check_startup_high_loss() to decide
it has detected some high loss as mentioned by the BBR v3 RFC draft:

   4.3.1.3. Exiting Startup Based on Packet Loss
   ...
   There are at least BBRStartupFullLossCnt=6 discontiguous sequence ranges lost in that round trip.

where a <= operator was used in place of <.

Must be backported to 3.1.
---

diff --git a/src/quic_cc_bbr.c b/src/quic_cc_bbr.c
index 6179c9f24b..3f49417eec 100644
--- a/src/quic_cc_bbr.c
+++ b/src/quic_cc_bbr.c
@@ -677,7 +677,7 @@ static void bbr_check_full_bw_reached(struct bbr *bbr, struct quic_cc_path *p)
 static void bbr_check_startup_high_loss(struct bbr *bbr, struct quic_cc_path *p)
 {
 	if (bbr->full_bw_reached ||
-	    bbr->loss_events_in_round <= BBR_STARTUP_FULL_LOSS_COUNT ||
+	    bbr->loss_events_in_round < BBR_STARTUP_FULL_LOSS_COUNT ||
 	    (bbr->in_loss_recovery &&
 	     bbr->round_count <= bbr->round_count_at_recovery) ||
 	    !is_inflight_too_high(&bbr->drs.rs)) {