zebra: If we hand set the router-id only update everyone if it changes

When we hand set the router-id, but we have choosen a router-id
that is already the `winner` there is no point in updating anyone
with this data.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/zebra/router-id.c b/zebra/router-id.c
index 689b9787ee..ac81d537d0 100644
--- a/zebra/router-id.c
+++ b/zebra/router-id.c
@@ -120,10 +120,12 @@ int router_id_get(afi_t afi, struct prefix *p, struct zebra_vrf *zvrf)
 
 static int router_id_set(afi_t afi, struct prefix *p, struct zebra_vrf *zvrf)
 {
-	struct prefix p2;
+	struct prefix after, before;
 	struct listnode *node;
 	struct zserv *client;
 
+	router_id_get(afi, &before, zvrf);
+
 	switch (afi) {
 	case AFI_IP:
 		zvrf->rid_user_assigned.u.prefix4.s_addr = p->u.prefix4.s_addr;
@@ -135,10 +137,17 @@ static int router_id_set(afi_t afi, struct prefix *p, struct zebra_vrf *zvrf)
 		return -1;
 	}
 
-	router_id_get(afi, &p2, zvrf);
+	router_id_get(afi, &after, zvrf);
+
+	/*
+	 * If we've been told that the router-id is exactly the same
+	 * do we need to really do anything here?
+	 */
+	if (prefix_same(&before, &after))
+		return 0;
 
 	for (ALL_LIST_ELEMENTS_RO(zrouter.client_list, node, client))
-		zsend_router_id_update(client, afi, &p2, zvrf->vrf->vrf_id);
+		zsend_router_id_update(client, afi, &after, zvrf->vrf->vrf_id);
 
 	return 0;
 }