clusterer_controller: an MI reload of the DB clusters keeps the controller clusters

clusterer:reload replaced the whole cluster list with what the DB holds,
so on a node with DB clusters beside controller clusters it dropped the
controller clusters from clusterer - their nodes, sharing tags' cluster
and the capabilities tm and dialog registered on them.  They now move
into the reloaded list as they are, and a DB cluster with the id of one
of them makes the reload fail.

Author: Lt-Flash

modules-contrib/clusterer_controller/clusterer_mod.c

@@ -882,6 +882,7 @@ mi_response_t *clusterer_reload(const mi_params_t *params,
 {
 	cluster_info_t *new_info;
 	cluster_info_t *old_info;
+	cluster_info_t *cl, *new_cl, **old_next, **new_tail;
 
 	if (!db_mode) {
 		LM_ERR("Running in non-DB mode\n");
@@ -894,6 +895,19 @@ mi_response_t *clusterer_reload(const mi_params_t *params,
 	}
 
 	lock_start_write(cl_list_lock);
+	for (cl = *cluster_list; cl; cl = cl->next) {
+		if (!cl->controller_managed)
+			continue;
+		for (new_cl = new_info; new_cl; new_cl = new_cl->next)
+			if (new_cl->cluster_id == cl->cluster_id) {
+				lock_stop_write(cl_list_lock);
+				LM_ERR("cluster %d in the DB is controller-managed here - "
+					"not reloaded\n", cl->cluster_id);
+				free_info(new_info);
+				return init_mi_error(400,
+					MI_SSTR("DB defines a controller-managed cluster"));
+			}
+	}
 	if (preserve_reg_caps(new_info) < 0) {
 		lock_stop_write(cl_list_lock);
 		LM_ERR("Failed to preserve registered capabilities\n");
@@ -904,6 +918,18 @@ mi_response_t *clusterer_reload(const mi_params_t *params,
 		return init_mi_error(500, "Failed to reload", 16);
 	}
 	old_info = *cluster_list;
+	/* the controller clusters are not in the DB: they move over as they are */
+	for (new_tail = &new_info; *new_tail; new_tail = &(*new_tail)->next) ;
+	for (old_next = &old_info; (cl = *old_next); ) {
+		if (cl->controller_managed) {
+			*old_next = cl->next;
+			cl->next = NULL;
+			*new_tail = cl;
+			new_tail = &cl->next;
+		} else {
+			old_next = &cl->next;
+		}
+	}
 	*cluster_list = new_info;
 	lock_stop_write(cl_list_lock);