MINOR: connection: remove an unwelcome dependency on struct stream

There was a reference to struct stream in conn_free() for the case
where we're freeing a connection that doesn't have a mux attached.
For now we know it's always a stream, and we only need to do it to
put a NULL in s->si[1].end.

Let's do it better by storing the pointer to si[1].end in the context
and specifying that this pointer is always nulled if the mux is null.
This way it allows a connection to detach itself from wherever it's
being used. Maybe we could even get rid of the condition on the mux.

diff --git a/include/proto/connection.h b/include/proto/connection.h
index 441b51df00b0539cfe6a607621e02f1c3bc97423..a7b596a50f0fc87c1478775914b4310d61078dcf 100644 (file)
--- a/include/proto/connection.h
+++ b/include/proto/connection.h
@@ -669,15 +669,14 @@ static inline void conn_free(struct connection *conn)
                sess->resp_conns--;
                LIST_DEL(&conn->session_list);
        }
-       /* If we temporarily stored the connection as the stream_interface's
-        * end point, remove it.
+
+       /* By convention we always place a NULL where the ctx points to if the
+        * mux is null. It may have been used to store the connection as a
+        * stream_interface's end point for example.
         */
-       if (conn->ctx != NULL && conn->mux == NULL) {
-               struct stream *s = conn->ctx;
+       if (conn->ctx != NULL && conn->mux == NULL)
+               *(void **)conn->ctx = NULL;
 
-               if (objt_conn(s->si[1].end) == conn)
-                       s->si[1].end = NULL;
-       }
        /* The connection is currently in the server's idle list, so tell it
         * there's one less connection available in that list.
         */

diff --git a/src/backend.c b/src/backend.c
index 237668cc432c847d91caf9f9f9da2f641eb67baf..2407f8a32ec37d24069a12c7ff55d2ae486dfc11 100644 (file)
--- a/src/backend.c
+++ b/src/backend.c
@@ -1052,12 +1052,13 @@ static void assign_tproxy_address(struct stream *s)
 #if defined(USE_OPENSSL) && defined(TLSEXT_TYPE_application_layer_protocol_negotiation)
 /*
  * Pick the right mux once the connection is established, we should now have
- * an alpn if available, so we are now able to choose.
+ * an alpn if available, so we are now able to choose. In this specific case
+ * the connection's context is &si[i].end.
  */
 static int conn_complete_server(struct connection *conn)
 {
        struct conn_stream *cs = NULL;
-       struct stream *s = conn->ctx;
+       struct stream *s = container_of(conn->ctx, struct stream, si[1].end);
        struct server *srv;
 
        task_wakeup(s->task, TASK_WOKEN_IO);
@@ -1066,8 +1067,6 @@ static int conn_complete_server(struct connection *conn)
        if (unlikely(!(conn->flags & (CO_FL_WAIT_L4_CONN | CO_FL_WAIT_L6_CONN | CO_FL_CONNECTED))))
                conn->flags |= CO_FL_CONNECTED;
 
-       if (!s)
-               goto fail;
        if (conn->flags & CO_FL_ERROR)
                goto fail;
        si_detach_endpoint(&s->si[1]);
@@ -1338,7 +1337,7 @@ int connect_server(struct stream *s)
                }
 #if defined(USE_OPENSSL) && defined(TLSEXT_TYPE_application_layer_protocol_negotiation)
                else {
-                       srv_conn->ctx = s;
+                       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