BUG/MEDIUM: stconn: Wait iobuf is empty to shut SE down during a check send

When a send attempt is performed on the opposite side from sc_notify() and
all outgoing data are sent while a shut was scheduled, the SE is shut down
because we consider all data were sent and no more are expected. However,
here we must also be carefull to have sent all pending data in the
iobuf. Indeed, some spliced data may be blocked. In this case, if the SE is
shut down, these data may be lost.

This patch should fix the original bug reported in #2749. It must be
backported as far as 2.9.

(cherry picked from commit 48f1e2b6fe8457bb5b9d8db9447157c244d871b7)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/src/stconn.c b/src/stconn.c
index bda1b61..274bf01 100644 (file)
--- a/src/stconn.c
+++ b/src/stconn.c
@@ -873,7 +873,7 @@ static void sc_app_chk_snd_conn(struct stconn *sc)
        /* OK, so now we know that some data might have been sent, and that we may
         * have to poll first. We have to do that too if the buffer is not empty.
         */
-       if (!co_data(oc)) {
+       if (!co_data(oc) && !sc_ep_have_ff_data(sc)) {
                /* the connection is established but we can't write. Either the
                 * buffer is empty, or we just refrain from sending because the
                 * ->o limit was reached. Maybe we just wrote the last