MEDIUM: stream-int: return the allocated appctx in stream_int_register_handler()

The task returned by stream_int_register_handler() is never used, however we
always need to access the appctx afterwards. So make it return the appctx
instead. We already plan for it to fail, which is the reason for the addition
of a few tests and the possibility for the HTTP analyser to return a status
code 500.

include/proto/stream_interface.h

@@ -42,8 +42,7 @@ extern struct si_ops si_embedded_ops;
 extern struct si_ops si_conn_ops;
 extern struct data_cb si_conn_cb;
 
-struct task *stream_int_register_handler(struct stream_interface *si,
-					 struct si_applet *app);
+struct appctx *stream_int_register_handler(struct stream_interface *si, struct si_applet *app);
 void stream_int_unregister_handler(struct stream_interface *si);
 
 /* initializes a stream interface in the SI_ST_INI state. It's detached from

src/dumpstats.c

@@ -159,8 +159,9 @@ static int stats_accept(struct session *s)
 	struct appctx *appctx;
 
 	s->target = &cli_applet.obj_type;
-	stream_int_register_handler(&s->si[1], objt_applet(s->target));
-	appctx = si_appctx(&s->si[1]);
+	appctx = stream_int_register_handler(&s->si[1], objt_applet(s->target));
+	if (!appctx)
+		return -1;
 	appctx->st1 = 0;
 	appctx->st0 = STAT_CLI_INIT;
 

src/peers.c

@@ -1097,8 +1097,9 @@ int peer_accept(struct session *s)
 	struct appctx *appctx;
 
 	s->target = &peer_applet.obj_type;
-	stream_int_register_handler(&s->si[1], objt_applet(s->target));
-	appctx = si_appctx(&s->si[1]);
+	appctx = stream_int_register_handler(&s->si[1], objt_applet(s->target));
+	if (!appctx)
+		return -1;
 	appctx->st0 = PEER_SESSION_ACCEPT;
 	appctx->ctx.peers.ptr = s;
 
@@ -1175,8 +1176,9 @@ static struct session *peer_session_create(struct peer *peer, struct peer_sessio
 	if (s->fe->options2 & PR_O2_INDEPSTR)
 		s->si[0].flags |= SI_FL_INDEP_STR;
 
-	stream_int_register_handler(&s->si[0], &peer_applet);
-	appctx = si_appctx(&s->si[0]);
+	appctx = stream_int_register_handler(&s->si[0], &peer_applet);
+	if (!appctx)
+		goto out_fail_conn1;
 	appctx->st0 = PEER_SESSION_CONNECT;
 	appctx->ctx.peers.ptr = (void *)ps;
 

src/proto_http.c

@@ -3461,8 +3461,15 @@ int http_process_req_common(struct session *s, struct channel *req, int an_bit,
 	if (!http_req_last_rule) {
 		if (stats_check_uri(s->rep->prod, txn, px)) {
 			s->target = &http_stats_applet.obj_type;
-			stream_int_register_handler(s->rep->prod, objt_applet(s->target));
+			if (unlikely(!stream_int_register_handler(s->rep->prod, objt_applet(s->target)))) {
+				txn->status = 500;
+				s->logs.tv_request = now;
+				stream_int_retnclose(req->prod, http_error_message(s, HTTP_ERR_500));
 
+				if (!(s->flags & SN_ERR_MASK))
+					s->flags |= SN_ERR_RESOURCE;
+				goto return_prx_cond;
+			}
 			/* parse the whole stats request and extract the relevant information */
 			http_handle_stats(s, req);
 			http_req_last_rule = http_req_get_intercept_rule(px, &px->uri_auth->http_req_rules, s, txn);

src/stream_interface.c

@@ -342,21 +342,21 @@ static void stream_int_chk_snd(struct stream_interface *si)
 		task_wakeup(si->owner, TASK_WOKEN_IO);
 }
 
-/* Register an applet to handle a stream_interface as part of the stream
- * interface's owner task, which is returned. The SI will wake it up everytime
- * it is solicited. The task's processing function must call the applet's
- * function before returning. It must be deleted by the task handler using
- * stream_int_unregister_handler(), possibly from within the function itself.
- * It also pre-initializes applet.state to zero and the connection context
- * to NULL.
+/* Register an applet to handle a stream_interface as part of the
+ * stream interface's owner task. The SI will wake it up everytime it
+ * is solicited.  The task's processing function must call the applet's
+ * function before returning. It must be deleted by the task handler
+ * using stream_int_unregister_handler(), possibly from within the
+ * function itself. It also pre-initializes the applet's context and
+ * returns it (or NULL in case it could not be allocated).
  */
-struct task *stream_int_register_handler(struct stream_interface *si, struct si_applet *app)
+struct appctx *stream_int_register_handler(struct stream_interface *si, struct si_applet *app)
 {
 	DPRINTF(stderr, "registering handler %p for si %p (was %p)\n", app, si, si->owner);
 
 	si_attach_applet(si, app);
 	si->flags |= SI_FL_WAIT_DATA;
-	return si->owner;
+	return si_appctx(si);
 }
 
 /* Unregister a stream interface handler. This must be called by the handler task