From: Christopher Faulet <cfaulet@haproxy.com>
Date: Tue, 2 Apr 2024 16:01:23 +0000 (+0200)
Subject: BUG/MEDIUM: stconn: Don't forward shutdown to SE if iobuf is not empty
X-Git-Tag: v3.0-dev7~35
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3abf6934a436a6fba14a44145c020663c81ef29d;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: stconn: Don't forward shutdown to SE if iobuf is not empty

It is only an issue when the kernel splicing is used. The zero-copy
forwarding via the buffers is not affected. When a shutdown is received on
the producer side and some data are blocked in the pipe for a while, the
shutdown may be forwarded to the other side. Usually, in this case, the
shutdown must be scheduled, waiting all output data (from the channel and
the consumer's iobuf) are sent. But only the channel was considered.

The bug was introduced by commit 20c463955d ("MEDIUM: channel: don't look at
iobuf to report an empty channel"). To fix the issue, we must also check
data blocked in the consummer iobuf.

This patch should solve the issue #2505. It must be backported to 2.9.
---

diff --git a/src/stconn.c b/src/stconn.c
index 0383e24048..acfa6cc395 100644
--- a/src/stconn.c
+++ b/src/stconn.c
@@ -531,7 +531,7 @@ static inline int sc_cond_forward_shut(struct stconn *sc)
 	if (!(sc->flags & (SC_FL_EOS|SC_FL_ABRT_DONE)) || !(sc->flags & SC_FL_NOHALF))
 		return 0;
 
-	if (co_data(sc_ic(sc)) && !(sc_ic(sc)->flags & CF_WRITE_TIMEOUT)) {
+	if ((co_data(sc_ic(sc)) || sc_ep_have_ff_data(sc_opposite(sc))) && !(sc_ic(sc)->flags & CF_WRITE_TIMEOUT)) {
 		/* the shutdown cannot be forwarded now because
 		 * we should flush outgoing data first. But instruct the output
 		 * channel it should be done ASAP.
@@ -1067,7 +1067,7 @@ void sc_notify(struct stconn *sc)
 	struct task *task = sc_strm_task(sc);
 
 	/* process consumer side */
-	if (!co_data(oc)) {
+	if (!co_data(oc) && !sc_ep_have_ff_data(sco)) {
 		struct connection *conn = sc_conn(sc);
 
 		if (((sc->flags & (SC_FL_SHUT_DONE|SC_FL_SHUT_WANTED)) == SC_FL_SHUT_WANTED) &&
diff --git a/src/stream.c b/src/stream.c
index 9d99d2f6b3..7052f7c30a 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -2369,7 +2369,7 @@ struct task *process_stream(struct task *t, void *context, unsigned int state)
 
 	/* shutdown(write) pending */
 	if (unlikely((scb->flags & (SC_FL_SHUT_DONE|SC_FL_SHUT_WANTED)) == SC_FL_SHUT_WANTED &&
-		     (!co_data(req) || (req->flags & CF_WRITE_TIMEOUT)))) {
+		     ((!co_data(req) && !sc_ep_have_ff_data(scb)) || (req->flags & CF_WRITE_TIMEOUT)))) {
 		if (scf->flags & SC_FL_ERROR)
 			scb->flags |= SC_FL_NOLINGER;
 		sc_shutdown(scb);
@@ -2477,7 +2477,7 @@ struct task *process_stream(struct task *t, void *context, unsigned int state)
 
 	/* shutdown(write) pending */
 	if (unlikely((scf->flags & (SC_FL_SHUT_DONE|SC_FL_SHUT_WANTED)) == SC_FL_SHUT_WANTED &&
-		     (!co_data(res) || (res->flags & CF_WRITE_TIMEOUT)))) {
+		     ((!co_data(res) && !sc_ep_have_ff_data(scf)) || (res->flags & CF_WRITE_TIMEOUT)))) {
 		sc_shutdown(scf);
 	}