From: Amaury Denoyelle <adenoyelle@haproxy.com>
Date: Wed, 8 Apr 2026 11:54:47 +0000 (+0200)
Subject: MINOR: xprt_qstrm: handle connection errors
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=10f2867dc27ea30bf5439a54318a2f8387a705fa;p=thirdparty%2Fhaproxy.git

MINOR: xprt_qstrm: handle connection errors

This patch implements proper connection error handling for xprt_qstrm
layer. Basically, processing is interrupted if CO_FL_ERROR is
encountered after either rcv_buf or snd_buf operations. Connectionn
error is set to the newly defined value CO_ER_QSTRM.
---

diff --git a/include/haproxy/connection-t.h b/include/haproxy/connection-t.h
index bc69ab353..a769ca0f1 100644
--- a/include/haproxy/connection-t.h
+++ b/include/haproxy/connection-t.h
@@ -285,6 +285,8 @@ enum {
 
 	CO_ER_SSL_FATAL,         /* SSL fatal error during a SSL_read or SSL_write */
 
+	CO_ER_QSTRM,             /* QMux transport parameter exchange failure */
+
 	CO_ER_REVERSE,           /* Error during reverse connect */
 
 	CO_ER_POLLERR,           /* we only noticed POLLERR */
diff --git a/src/connection.c b/src/connection.c
index e3b891528..f75895a76 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -863,6 +863,8 @@ const char *conn_err_code_str(struct connection *c)
 
 	case CO_ER_SSL_FATAL:      return "SSL fatal error";
 
+	case CO_ER_QSTRM:          return "Error during QMux transport parameters initial exchange";
+
 	case CO_ER_REVERSE:        return "Reverse connect failure";
 
 	case CO_ER_POLLERR:        return "Poller reported POLLERR";
diff --git a/src/session.c b/src/session.c
index e4b819617..f53cceb64 100644
--- a/src/session.c
+++ b/src/session.c
@@ -502,7 +502,8 @@ static void session_kill_embryonic(struct session *sess, unsigned int state)
 		if (!conn->err_code ||
 		    conn->err_code == CO_ER_PRX_EMPTY || conn->err_code == CO_ER_PRX_ABORT ||
 		    conn->err_code == CO_ER_CIP_EMPTY || conn->err_code == CO_ER_CIP_ABORT ||
-		    conn->err_code == CO_ER_SSL_EMPTY || conn->err_code == CO_ER_SSL_ABORT)
+		    conn->err_code == CO_ER_SSL_EMPTY || conn->err_code == CO_ER_SSL_ABORT ||
+		    conn->err_code == CO_ER_QSTRM)
 			log = 0;
 	}
 
@@ -514,6 +515,8 @@ static void session_kill_embryonic(struct session *sess, unsigned int state)
 				conn->err_code = CO_ER_CIP_TIMEOUT;
 			else if (conn->flags & CO_FL_SSL_WAIT_HS)
 				conn->err_code = CO_ER_SSL_TIMEOUT;
+			else if (conn->flags & CO_FL_QSTRM_RECV)
+				conn->err_code = CO_ER_QSTRM;
 		}
 
 		sess_log_embryonic(sess);
diff --git a/src/xprt_qstrm.c b/src/xprt_qstrm.c
index ce7a50f74..01a9265fc 100644
--- a/src/xprt_qstrm.c
+++ b/src/xprt_qstrm.c
@@ -65,7 +65,8 @@ int conn_recv_qstrm(struct connection *conn, struct xprt_qstrm_ctx *ctx, int fla
 
 	do {
 		ret = ctx->ops_lower->rcv_buf(conn, ctx->ctx_lower, buf, b_room(buf), NULL, 0, 0);
-		BUG_ON(conn->flags & CO_FL_ERROR);
+		if (conn->flags & CO_FL_ERROR)
+			goto fail;
 	} while (ret);
 
 	if (!b_data(buf))
@@ -91,6 +92,7 @@ int conn_recv_qstrm(struct connection *conn, struct xprt_qstrm_ctx *ctx, int fla
 	return 0;
 
  fail:
+	conn->err_code = CO_ER_QSTRM;
 	conn->flags |= CO_FL_ERROR;
 	return 0;
 }
@@ -123,6 +125,9 @@ int conn_send_qstrm(struct connection *conn, struct xprt_qstrm_ctx *ctx, int fla
 
 	sent = ctx->ops_lower->snd_buf(conn, ctx->ctx_lower, buf, b_data(buf),
 	                               NULL, 0, 0);
+	if (conn->flags & CO_FL_ERROR)
+		goto fail;
+
 	b_del(buf, sent);
 	if (b_data(buf))
 		goto retry;
@@ -135,6 +140,7 @@ int conn_send_qstrm(struct connection *conn, struct xprt_qstrm_ctx *ctx, int fla
 	return 0;
 
  fail:
+	conn->err_code = CO_ER_QSTRM;
 	conn->flags |= CO_FL_ERROR;
 	return 0;
 }
@@ -143,20 +149,23 @@ struct task *xprt_qstrm_io_cb(struct task *t, void *context, unsigned int state)
 {
 	struct xprt_qstrm_ctx *ctx = context;
 	struct connection *conn = ctx->conn;
-	int ret;
 
 	if (conn->flags & CO_FL_QSTRM_SEND) {
 		if (!conn_send_qstrm(conn, ctx, CO_FL_QSTRM_SEND)) {
-			ctx->ops_lower->subscribe(conn, ctx->ctx_lower,
-			                          SUB_RETRY_SEND, &ctx->wait_event);
+			if (!(conn->flags & CO_FL_ERROR)) {
+				ctx->ops_lower->subscribe(conn, ctx->ctx_lower,
+				                          SUB_RETRY_SEND, &ctx->wait_event);
+			}
 			goto out;
 		}
 	}
 
 	if (conn->flags & CO_FL_QSTRM_RECV) {
 		if (!conn_recv_qstrm(conn, ctx, CO_FL_QSTRM_RECV)) {
-			ctx->ops_lower->subscribe(conn, ctx->ctx_lower,
-			                          SUB_RETRY_RECV, &ctx->wait_event);
+			if (!(conn->flags & CO_FL_ERROR)) {
+				ctx->ops_lower->subscribe(conn, ctx->ctx_lower,
+				                          SUB_RETRY_RECV, &ctx->wait_event);
+			}
 			goto out;
 		}
 	}
@@ -164,15 +173,17 @@ struct task *xprt_qstrm_io_cb(struct task *t, void *context, unsigned int state)
  out:
 	if ((conn->flags & CO_FL_ERROR) ||
 	    !(conn->flags & (CO_FL_QSTRM_RECV|CO_FL_QSTRM_SEND))) {
+		/* XPRT should be unsubscribed when transfer done or on error. */
+		BUG_ON(ctx->wait_event.events);
+
 		/* MUX will access members from xprt_ctx on init, so create
 		 * operation should be called before any members are resetted.
 		 */
-		ret = conn_create_mux(conn, NULL);
-		BUG_ON(ret);
+		if (conn_create_mux(conn, NULL) == 0)
+			conn->mux->wake(conn);
 
 		conn->xprt_ctx = ctx->ctx_lower;
 		conn->xprt = ctx->ops_lower;
-		conn->mux->wake(conn);
 
 		b_free(&ctx->rxbuf);
 		b_free(&ctx->txbuf);