tree b0918e0e75bee46ae6155732fb5cb9163505f2dc
parent 6d215536f4aa2e3c95fde9d001a1c894d4eecb93
author Willy Tarreau <w@1wt.eu> 1569480435 +0200
committer Christopher Faulet <cfaulet@haproxy.com> 1569578093 +0200

BUG/MEDIUM: mux-h2: don't reject valid frames on closed streams

Consecutive to commit 6884aa3eb0 ("BUG/MAJOR: mux-h2: Handle HEADERS frames
received after a RST_STREAM frame") some valid frames on closed streams
(RST_STREAM, PRIORITY, WINDOW_UPDATE) were now rejected. It turns out that
the previous condition was in fact intentional to catch only sensitive
frames, which was indeed a mistake since these ones needed to be decoded
to keep HPACK synchronized. But we must absolutely accept WINDOW_UPDATES
or we risk to stall some transfers. And RST/PRIO definitely are valid.

Let's adjust the condition to reflect that and update the comment to
explain the reason for this unobvious condition.

This must be backported to 2.0 and 1.9 after the commit above is brought
there.

(cherry picked from commit 4c08f12dd86bda574c15261bcd69135dd662f990)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>