From: Christopher Faulet <cfaulet@haproxy.com>
Date: Fri, 13 Jan 2023 10:28:31 +0000 (+0100)
Subject: BUG/MEDIUM: mux-h2: Don't send CANCEL on shutw when response length is unkown
X-Git-Tag: v2.8-dev2~39
X-Git-Url: http://git.haproxy.org/?a=commitdiff_plain;h=462f52260c0685696b1521ef9e5276b98ba98cde;p=haproxy-3.0.git

BUG/MEDIUM: mux-h2: Don't send CANCEL on shutw when response length is unkown

Since commit 473e0e54 ("BUG/MINOR: mux-h2: send a CANCEL instead of ES on
truncated writes"), a CANCEL may be reported when the response length is
unkown. It happens for H1 reponses without "Content-lenght" or
"Transfer-encoding" header.

Indeed, in this case, the end of the reponse is detected when the server
connection is closed. On the fontend side, the H2 multiplexer handles this
event as an abort and sensd a RST_STREAM frame with CANCEL error code.

The issue is not with the above commit but with the commit 4877045f1
("MINOR: mux-h2: make streams know if they need to send more data"). The
H2_SF_MORE_HTX_DATA flag must only be set if the payload length can be
determined.

This patch should fix the issue #1992. It must be backported to 2.7.
---

diff --git a/src/mux_h2.c b/src/mux_h2.c
index 22b1f1e..4c29a28 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -6356,7 +6356,7 @@ static size_t h2_snd_buf(struct stconn *sc, struct buffer *buf, size_t count, in
 	if (!(h2s->flags & H2_SF_OUTGOING_DATA) && count)
 		h2s->flags |= H2_SF_OUTGOING_DATA;
 
-	if (htx->extra)
+	if (htx->extra && htx->extra != ULLONG_MAX)
 		h2s->flags |= H2_SF_MORE_HTX_DATA;
 	else
 		h2s->flags &= ~H2_SF_MORE_HTX_DATA;