ospf6d: missing ECMP NHs in certain topologies

[mirror_frr.git] / ospf6d / ospf6_spf.c

diff --git a/ospf6d/ospf6_spf.c b/ospf6d/ospf6_spf.c
index 3cc0d5e96386ab61867c3a3c8f445c403a3a2c50..0990b14307f2254156c406ae36cf118d29d440f9 100644 (file)
--- a/ospf6d/ospf6_spf.c
+++ b/ospf6d/ospf6_spf.c
@@ -310,7 +310,7 @@ static void ospf6_nexthop_calc(struct ospf6_vertex *w, struct ospf6_vertex *v,
 static int ospf6_spf_install(struct ospf6_vertex *v,
                             struct ospf6_route_table *result_table)
 {
-       struct ospf6_route *route, *parent_route;
+       struct ospf6_route *route;
        struct ospf6_vertex *prev;
 
        if (IS_OSPF6_DEBUG_SPF(PROCESS))
@@ -330,7 +330,12 @@ static int ospf6_spf_install(struct ospf6_vertex *v,
                        zlog_debug(
                                "  another path found to route %pFX lsa %s, merge",
                                &route->prefix, v->lsa->name);
-               ospf6_spf_merge_nexthops_to_route(route, v);
+
+               /* merging the parent's nexthop information to the child's
+                * if the parent is not the root of the tree.
+                */
+               if (!ospf6_merge_parents_nh_to_child(v, route, result_table))
+                       ospf6_spf_merge_nexthops_to_route(route, v);
 
                prev = (struct ospf6_vertex *)route->route_option;
                assert(prev->hops <= v->hops);
@@ -396,13 +401,7 @@ static int ospf6_spf_install(struct ospf6_vertex *v,
         * installed,
         * its parent's route's nexthops have already been installed.
         */
-       if (v->parent && v->parent->hops) {
-               parent_route =
-                       ospf6_route_lookup(&v->parent->vertex_id, result_table);
-               if (parent_route) {
-                       ospf6_route_merge_nexthops(route, parent_route);
-               }
-       }
+       ospf6_merge_parents_nh_to_child(v, route, result_table);
 
        if (v->parent)
                listnode_add_sort(v->parent->child_list, v);
@@ -1275,3 +1274,20 @@ void ospf6_ase_calculate_timer_add(struct ospf6 *ospf6)
        event_add_timer(master, ospf6_ase_calculate_timer, ospf6,
                        OSPF6_ASE_CALC_INTERVAL, &ospf6->t_ase_calc);
 }
+
+bool ospf6_merge_parents_nh_to_child(struct ospf6_vertex *v,
+                                    struct ospf6_route *route,
+                                    struct ospf6_route_table *result_table)
+{
+       struct ospf6_route *parent_route;
+
+       if (v->parent && v->parent->hops) {
+               parent_route =
+                       ospf6_route_lookup(&v->parent->vertex_id, result_table);
+               if (parent_route) {
+                       ospf6_route_merge_nexthops(route, parent_route);
+                       return true;
+               }
+       }
+       return false;
+}