From: Sergey Kandaurov <pluknet@nginx.com>
Date: Tue, 9 May 2023 15:42:38 +0000 (+0400)
Subject: QUIC: removed check for in-flight packets in computing PTO.
X-Git-Url: http://www.kaiwu.me/postgresql/commit/static/gitweb.js?a=commitdiff_plain;h=f0537cf17cec8a823c5b81c8f07a2508d7366720;p=nginx.git

QUIC: removed check for in-flight packets in computing PTO.

The check is needed for clients in order to unblock a server due to
anti-amplification limits, and it seems to make no sense for servers.
See RFC 9002, A.6 and A.8 for a further explanation.

This makes max_ack_delay to now always account, notably including
PATH_CHALLENGE timers as noted in the last paragraph of 9000, 9.4,
unlike when it was only used when there are packets in flight.

While here, fixed nearby style.
---

diff --git a/src/event/quic/ngx_event_quic_ack.c b/src/event/quic/ngx_event_quic_ack.c
index d236deb59..2458c9aea 100644
--- a/src/event/quic/ngx_event_quic_ack.c
+++ b/src/event/quic/ngx_event_quic_ack.c
@@ -782,15 +782,11 @@ ngx_quic_pto(ngx_connection_t *c, ngx_quic_send_ctx_t *ctx)
     qc = ngx_quic_get_connection(c);
 
     /* RFC 9002, Appendix A.8.  Setting the Loss Detection Timer */
-    duration = qc->avg_rtt;
 
+    duration = qc->avg_rtt;
     duration += ngx_max(4 * qc->rttvar, NGX_QUIC_TIME_GRANULARITY);
     duration <<= qc->pto_count;
 
-    if (qc->congestion.in_flight == 0) { /* no in-flight packets */
-        return duration;
-    }
-
     if (ctx->level == ssl_encryption_application && c->ssl->handshaked) {
         duration += qc->ctp.max_ack_delay << qc->pto_count;
     }