ospf6d: Fix External routes ECMP

Handle RFC 2328 16.4 Calculating AS external routes with ECMP

For ASBR route, if it is learnt via new LSA and contains
different nexthop list. First lookup route in ospf6 route table
if it exists, merge nexthop list to existing and call the callback
to install into FIB (zebra). Delete created new route as it is
identical to existing entry in route table.

Ticket:CM-16139
Testing Done:
Run two ASBR with 2 ECMP paths from each
DUT neighbor receievs 4 ECMP path to a external route.
ospf6 installs all 4 ECMP path to FIB/RIB

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

1 files changed, 46 insertions, 4 deletions

diff --git a/ospf6d/ospf6_route.c b/ospf6d/ospf6_route.c
index 281757222d..735b28a693 100644
--- a/ospf6d/ospf6_route.c
+++ b/ospf6d/ospf6_route.c
@@ -215,7 +215,7 @@ void ospf6_copy_nexthops(struct list *dst, struct list *src)
 			if (ospf6_nexthop_is_set(nh)) {
 				nh_new = ospf6_nexthop_create();
 				ospf6_nexthop_copy(nh_new, nh);
-				listnode_add(dst, nh_new);
+				listnode_add_sort(dst, nh_new);
 			}
 		}
 	}
@@ -231,7 +231,7 @@ void ospf6_merge_nexthops(struct list *dst, struct list *src)
 			if (!ospf6_route_find_nexthop(dst, nh)) {
 				nh_new = ospf6_nexthop_create();
 				ospf6_nexthop_copy(nh_new, nh);
-				listnode_add(dst, nh_new);
+				listnode_add_sort(dst, nh_new);
 			}
 		}
 	}
@@ -338,7 +338,7 @@ int ospf6_route_get_first_nh_index(struct ospf6_route *route)
 	return (-1);
 }
 
-static int ospf6_nexthop_cmp(struct ospf6_nexthop *a, struct ospf6_nexthop *b)
+int ospf6_nexthop_cmp(struct ospf6_nexthop *a, struct ospf6_nexthop *b)
 {
 	if (a->ifindex < b->ifindex)
 		return -1;
@@ -351,6 +351,36 @@ static int ospf6_nexthop_cmp(struct ospf6_nexthop *a, struct ospf6_nexthop *b)
 	return 0;
 }
 
+static int ospf6_path_cmp(struct ospf6_path *a, struct ospf6_path *b)
+{
+	if (a->origin.adv_router < b->origin.adv_router)
+		return -1;
+	else if (a->origin.adv_router > b->origin.adv_router)
+		return 1;
+	else
+		return 0;
+}
+
+void ospf6_path_free(struct ospf6_path *op)
+{
+	if (op->nh_list)
+		list_delete_and_null(&op->nh_list);
+	XFREE(MTYPE_OSPF6_PATH, op);
+}
+
+struct ospf6_path *ospf6_path_dup(struct ospf6_path *path)
+{
+	struct ospf6_path *new;
+
+	new = XCALLOC(MTYPE_OSPF6_PATH, sizeof(struct ospf6_path));
+	memcpy(new, path, sizeof(struct ospf6_path));
+	new->nh_list = list_new();
+	new->nh_list->cmp = (int (*)(void *, void *))ospf6_nexthop_cmp;
+	new->nh_list->del = (void (*) (void *))ospf6_nexthop_delete;
+
+	return new;
+}
+
 struct ospf6_route *ospf6_route_create(void)
 {
 	struct ospf6_route *route;
@@ -358,6 +388,9 @@ struct ospf6_route *ospf6_route_create(void)
 	route->nh_list = list_new();
 	route->nh_list->cmp = (int (*)(void *, void *))ospf6_nexthop_cmp;
 	route->nh_list->del = (void (*) (void *))ospf6_nexthop_delete;
+	route->paths = list_new();
+	route->paths->cmp = (int (*)(void *, void *))ospf6_path_cmp;
+	route->paths->del =  (void (*)(void *))ospf6_path_free;
 	return route;
 }
 
@@ -366,6 +399,8 @@ void ospf6_route_delete(struct ospf6_route *route)
 	if (route) {
 		if (route->nh_list)
 			list_delete_and_null(&route->nh_list);
+		if (route->paths)
+			list_delete_and_null(&route->paths);
 		XFREE(MTYPE_OSPF6_ROUTE, route);
 	}
 }
@@ -464,7 +499,13 @@ ospf6_route_lookup_identical(struct ospf6_route *route,
 
 	for (target = ospf6_route_lookup(&route->prefix, table); target;
 	     target = target->next) {
-		if (ospf6_route_is_identical(target, route))
+		if (target->type == route->type &&
+		    (memcmp(&target->prefix, &route->prefix,
+			   sizeof(struct prefix)) == 0) &&
+		    target->path.type == route->path.type &&
+		    target->path.cost == route->path.cost &&
+		    target->path.u.cost_e2 == route->path.u.cost_e2 &&
+		    ospf6_route_cmp_nexthops(target, route) == 0)
 			return target;
 	}
 	return NULL;
@@ -1083,6 +1124,7 @@ void ospf6_route_show_detail(struct vty *vty, struct ospf6_route *route)
 	vty_out(vty, "Metric: %d (%d)\n", route->path.cost,
 		route->path.u.cost_e2);
 
+	vty_out(vty, "Paths count: %u\n", route->paths->count);
 	vty_out(vty, "Nexthop count: %u\n", route->nh_list->count);
 	/* Nexthops */
 	vty_out(vty, "Nexthop:\n");