From f5a16879b22d584941561122e7b36c3ecb6c953e Mon Sep 17 00:00:00 2001
From: Alexander Rose <alexander.rose@secunet.com>
Date: Wed, 27 Mar 2024 14:33:21 +0100
Subject: [PATCH] ospf6d: Fix metric when sending AS-external LSAs

When ospf6d originates an AS-external route that has been read from a kernel
routing table, then the metric of that route was ignored until now.
In my case all of these routes were announced with metric 1 in LS-updates.

Now the metric of the kernel route is added to whatever metric ospf6d already
computed originally.

Signed-off-by: Alexander Rose <alexander.rose@secunet.com>
---
 ospf6d/ospf6_asbr.c  | 20 ++++++++++++--------
 ospf6d/ospf6_asbr.h  |  3 ++-
 ospf6d/ospf6_zebra.c |  2 +-
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/ospf6d/ospf6_asbr.c b/ospf6d/ospf6_asbr.c
index d1c2b8bfc9a4..050f0498a913 100644
--- a/ospf6d/ospf6_asbr.c
+++ b/ospf6d/ospf6_asbr.c
@@ -1426,10 +1426,9 @@ static void ospf6_external_lsa_fwd_addr_set(struct ospf6 *ospf6,
 }
 
 void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
-				 struct prefix *prefix,
-				 unsigned int nexthop_num,
-				 const struct in6_addr *nexthop,
-				 route_tag_t tag, struct ospf6 *ospf6)
+				 struct prefix *prefix, unsigned int nexthop_num,
+				 const struct in6_addr *nexthop, route_tag_t tag,
+				 struct ospf6 *ospf6, uint32_t metric)
 {
 	route_map_result_t ret;
 	struct ospf6_route troute;
@@ -1498,9 +1497,10 @@ void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
 				match->path.metric_type =
 					metric_type(ospf6, type, 0);
 			if (troute.path.cost)
-				match->path.cost = troute.path.cost;
+				match->path.cost = troute.path.cost + metric;
 			else
-				match->path.cost = metric_value(ospf6, type, 0);
+				match->path.cost =
+					metric_value(ospf6, type, 0) + metric;
 
 			if (!IN6_IS_ADDR_UNSPECIFIED(&tinfo.forwarding))
 				memcpy(&info->forwarding, &tinfo.forwarding,
@@ -1511,10 +1511,14 @@ void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
 			 * metric fields
 			 */
 			match->path.metric_type = metric_type(ospf6, type, 0);
-			match->path.cost = metric_value(ospf6, type, 0);
+			match->path.cost = metric_value(ospf6, type, 0) + metric;
 			info->tag = tag;
 		}
 
+		/* sum of metrics caused an overflow */
+		if (match->path.cost < metric)
+			match->path.cost = UINT32_MAX;
+
 		info->type = type;
 
 		if (nexthop_num && nexthop) {
@@ -1924,7 +1928,7 @@ static void ospf6_redistribute_default_set(struct ospf6 *ospf6, int originate)
 	case DEFAULT_ORIGINATE_ALWAYS:
 		ospf6_asbr_redistribute_add(DEFAULT_ROUTE, 0,
 					    (struct prefix *)&p, 0, &nexthop, 0,
-					    ospf6);
+					    ospf6, 0);
 		break;
 	}
 }
diff --git a/ospf6d/ospf6_asbr.h b/ospf6d/ospf6_asbr.h
index d63e46727890..d69b85ea6830 100644
--- a/ospf6d/ospf6_asbr.h
+++ b/ospf6d/ospf6_asbr.h
@@ -115,7 +115,8 @@ extern void ospf6_asbr_redistribute_add(int type, ifindex_t ifindex,
 					struct prefix *prefix,
 					unsigned int nexthop_num,
 					const struct in6_addr *nexthop,
-					route_tag_t tag, struct ospf6 *ospf6);
+					route_tag_t tag, struct ospf6 *ospf6,
+					uint32_t metric);
 extern void ospf6_asbr_redistribute_remove(int type, ifindex_t ifindex,
 					   struct prefix *prefix,
 					   struct ospf6 *ospf6);
diff --git a/ospf6d/ospf6_zebra.c b/ospf6d/ospf6_zebra.c
index 3245578b07f2..911f3567d453 100644
--- a/ospf6d/ospf6_zebra.c
+++ b/ospf6d/ospf6_zebra.c
@@ -289,7 +289,7 @@ static int ospf6_zebra_read_route(ZAPI_CALLBACK_ARGS)
 	if (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD)
 		ospf6_asbr_redistribute_add(api.type, ifindex, &api.prefix,
 					    api.nexthop_num, nexthop, api.tag,
-					    ospf6);
+					    ospf6, api.metric);
 	else
 		ospf6_asbr_redistribute_remove(api.type, ifindex, &api.prefix,
 					       ospf6);