From 8af03b396a6025437b675f9ecaa5db321ec4918c Mon Sep 17 00:00:00 2001
From: Olivier Houchard <ohouchard@haproxy.com>
Date: Wed, 22 Jan 2020 17:34:54 +0100
Subject: [PATCH] MEDIUM: streams: Always create a conn_stream in
 connect_server().

In connect_server(), when creating a new connection for which we don't yet
know the mux (because it'll be decided by the ALPN), instead of associating
the connection to the stream_interface, always create a conn_stream. This way,
we have less special-casing needed. Store the conn_stream in conn->ctx,
so that we can reach the upper layers if needed.
---
 include/proto/stream_interface.h |  7 +----
 src/backend.c                    | 44 ++++++++------------------------
 src/stream_interface.c           |  2 +-
 3 files changed, 12 insertions(+), 41 deletions(-)

diff --git a/include/proto/stream_interface.h b/include/proto/stream_interface.h
index c0f88b265c..d1e228b092 100644
--- a/include/proto/stream_interface.h
+++ b/include/proto/stream_interface.h
@@ -172,7 +172,6 @@ static inline enum obj_type *si_detach_endpoint(struct stream_interface *si)
  */
 static inline void si_release_endpoint(struct stream_interface *si)
 {
-	struct connection *conn;
 	struct conn_stream *cs;
 	struct appctx *appctx;
 
@@ -189,10 +188,6 @@ static inline void si_release_endpoint(struct stream_interface *si)
 		if (appctx->applet->release && !si_state_in(si->state, SI_SB_DIS|SI_SB_CLO))
 			appctx->applet->release(appctx);
 		appctx_free(appctx);
-	} else if ((conn = objt_conn(si->end))) {
-		conn_stop_tracking(conn);
-		conn_full_close(conn);
-		conn_free(conn);
 	}
 	si_detach_endpoint(si);
 }
@@ -478,7 +473,7 @@ static inline int si_sync_recv(struct stream_interface *si)
 		return 0;
 
 	cs = objt_cs(si->end);
-	if (!cs)
+	if (!cs || !cs->conn->mux)
 		return 0; // only conn_streams are supported
 
 	if (si->wait_event.events & SUB_RETRY_RECV)
diff --git a/src/backend.c b/src/backend.c
index 0a91a68756..4bb30adfb9 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1083,7 +1083,8 @@ static void assign_tproxy_address(struct stream *s)
  */
 static int conn_complete_server(struct connection *conn)
 {
-	struct stream *s = container_of(conn->ctx, struct stream, si[1].end);
+	struct conn_stream *cs = conn->ctx;
+	struct stream *s = si_strm((struct stream_interface *)cs->data);
 
 	task_wakeup(s->task, TASK_WOKEN_IO);
 	conn_clear_xprt_done_cb(conn);
@@ -1408,32 +1409,20 @@ int connect_server(struct stream *s)
 			return SF_ERR_INTERNAL;  /* how did we get there ? */
 
 #if defined(USE_OPENSSL) && defined(TLSEXT_TYPE_application_layer_protocol_negotiation)
+		srv_cs = si_alloc_cs(&s->si[1], srv_conn);
+		if (!srv_cs) {
+			conn_free(srv_conn);
+			return SF_ERR_RESOURCE;
+		}
+		srv_conn->ctx = srv_cs;
 		if (!srv ||
 		    ((!(srv->ssl_ctx.alpn_str) && !(srv->ssl_ctx.npn_str)) ||
 		    srv->mux_proto || s->be->mode != PR_MODE_HTTP))
 #endif
-		{
-			srv_cs = objt_cs(s->si[1].end);
-			if (!srv_cs || srv_cs->conn != srv_conn)
-				srv_cs = si_alloc_cs(&s->si[1], srv_conn);
-			if (!srv_cs) {
-				conn_free(srv_conn);
-				return SF_ERR_RESOURCE;
-			}
 			init_mux = 1;
-		}
 #if defined(USE_OPENSSL) && defined(TLSEXT_TYPE_application_layer_protocol_negotiation)
-		else {
-			srv_conn->ctx = &s->si[1].end;
-			/* Store the connection into the stream interface,
-			 * while we still don't have a mux, so that if the
-			 * stream is destroyed before the connection is
-			 * established, we have a chance to destroy it even
-			 * if it is no longer referenced in the session.
-			 */
-			s->si[1].end = &srv_conn->obj_type;
+		else
 			conn_set_xprt_done_cb(srv_conn, conn_complete_server);
-		}
 
 #endif
 		/* process the case where the server requires the PROXY protocol to be sent */
@@ -1978,10 +1967,6 @@ void back_handle_st_con(struct stream *s)
 
 		if (conn->flags & CO_FL_ERROR)
 			goto fail;
-		si_detach_endpoint(&s->si[1]);
-		srv_cs = si_alloc_cs(&s->si[1], conn);
-		if (!srv_cs)
-			goto fail;
 		if (conn_install_mux_be(conn, srv_cs, s->sess) < 0)
 			goto fail;
 		srv = objt_server(s->target);
@@ -1991,16 +1976,7 @@ void back_handle_st_con(struct stream *s)
 		goto done;
 
 	fail:
-		si_detach_endpoint(&s->si[1]);
-		if (srv_cs)
-			cs_free(srv_cs);
-		/* kill the connection now */
-		conn_stop_tracking(conn);
-		conn_full_close(conn);
-		conn_free(conn);
-		conn = NULL;
-		/* Let process_stream know it went wrong */
-		s->si[1].flags |= SI_FL_ERR;
+		si_release_endpoint(&s->si[1]);
 	}
 
  done:
diff --git a/src/stream_interface.c b/src/stream_interface.c
index ba82cae945..e1c51f4d73 100644
--- a/src/stream_interface.c
+++ b/src/stream_interface.c
@@ -923,7 +923,7 @@ void si_sync_send(struct stream_interface *si)
 		return;
 
 	cs = objt_cs(si->end);
-	if (!cs)
+	if (!cs || !cs->conn->mux)
 		return;
 
 	si_cs_send(cs);