Track nexthops when the underlying route is changing. Until now true nexthops

were only resolved when they were added. This calls for troubles if something
like ospfd starts to change the underlying routes.
Tested by gollo@, OK henning@

1 files changed, 22 insertions, 7 deletions

diff --git a/usr.sbin/bgpd/rde_rib.c b/usr.sbin/bgpd/rde_rib.c
index 609660f69c4..6e3410cb31a 100644
--- a/usr.sbin/bgpd/rde_rib.c
+++ b/usr.sbin/bgpd/rde_rib.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde_rib.c,v 1.96 2007/06/01 04:17:30 claudio Exp $ */
+/*	$OpenBSD: rde_rib.c,v 1.97 2008/11/21 17:41:22 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Claudio Jeker <claudio@openbsd.org>
@@ -616,7 +616,8 @@ prefix_bypeer(struct pt_entry *pte, struct rde_peer *peer, u_int32_t flags)
 }
 
 void
-prefix_updateall(struct rde_aspath *asp, enum nexthop_state state)
+prefix_updateall(struct rde_aspath *asp, enum nexthop_state state,
+    enum nexthop_state oldstate)
 {
 	struct prefix	*p;
 
@@ -632,6 +633,18 @@ prefix_updateall(struct rde_aspath *asp, enum nexthop_state state)
 		if (!(p->flags & F_LOCAL))
 			continue;
 
+		if (oldstate == state && state == NEXTHOP_REACH) {
+			/*
+			 * The state of the nexthop did not change. The only
+			 * thing that may have changed is the true_nexthop
+			 * or other internal infos. This will not change
+			 * the routing decision so shortcut here.
+			 */
+			if (p == p->prefix->active)
+				rde_send_kroute(p, NULL);
+			continue;
+		}
+
 		/* redo the route decision */
 		LIST_REMOVE(p, prefix_l);
 		/*
@@ -817,6 +830,7 @@ nexthop_update(struct kroute_nexthop *msg)
 {
 	struct nexthop		*nh;
 	struct rde_aspath	*asp;
+	enum nexthop_state	 oldstate;
 
 	nh = nexthop_lookup(&msg->nexthop);
 	if (nh == NULL) {
@@ -825,15 +839,16 @@ nexthop_update(struct kroute_nexthop *msg)
 		return;
 	}
 
+	if (nexthop_delete(nh))
+		/* nexthop no longer used */
+		return;
+
+	oldstate = nh->state;
 	if (msg->valid)
 		nh->state = NEXTHOP_REACH;
 	else
 		nh->state = NEXTHOP_UNREACH;
 
-	if (nexthop_delete(nh))
-		/* nexthop no longer used */
-		return;
-
 	if (msg->connected) {
 		nh->flags |= NEXTHOP_CONNECTED;
 		memcpy(&nh->true_nexthop, &nh->exit_nexthop,
@@ -866,7 +881,7 @@ nexthop_update(struct kroute_nexthop *msg)
 		return;
 
 	LIST_FOREACH(asp, &nh->path_h, nexthop_l) {
-		prefix_updateall(asp, nh->state);
+		prefix_updateall(asp, nh->state, oldstate);
 	}
 }