Improve the handling of "counting to infinity" mechanism and add an heuristic

higly recommended in the rfc.

tested by me and OK claudio@

4 files changed, 50 insertions, 19 deletions

diff --git a/usr.sbin/ripd/rde.c b/usr.sbin/ripd/rde.c
index 22b93adaebe..408bc97731e 100644
--- a/usr.sbin/ripd/rde.c
+++ b/usr.sbin/ripd/rde.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde.c,v 1.5 2007/03/31 09:49:20 michele Exp $ */
+/*	$OpenBSD: rde.c,v 1.6 2007/04/09 20:45:52 michele Exp $ */
 
 /*
  * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it>
@@ -383,6 +383,7 @@ rde_send_delete_kroute(struct rt_node *r)
 int
 rde_check_route(struct rip_route *e)
 {
+	struct timeval	 tv, now;
 	struct rt_node	*rn;
 	struct iface	*iface;
 	int		 metric;
@@ -396,17 +397,14 @@ rde_check_route(struct rip_route *e)
 	    htonl(INADDR_LOOPBACK & IN_CLASSA_NET))
 		return (-1);
 
-	if (e->metric > INFINITY)
-		return (-1);
-
 	if ((iface = if_find_index(e->ifindex)) == NULL)
 		return (-1);
 
 	metric = MIN(INFINITY, e->metric + iface->cost);
-	if (metric >= INFINITY)
-		return (0);
 
 	if ((rn = rt_find(e->address.s_addr, e->mask.s_addr)) == NULL) {
+		if (metric >= INFINITY)
+			return (0);
 		rn = rt_new_rr(e, metric);
 		rt_insert(rn);
 		rde_send_change_kroute(rn);
@@ -427,13 +425,31 @@ rde_check_route(struct rip_route *e)
 			rde_send_change_kroute(rn);
 			triggered_update(rn);
 		} else if (e->nexthop.s_addr == rn->nexthop.s_addr &&
-		    e->metric > metric) {
-			rn->metric = metric;
-			rde_send_change_kroute(rn);
-			triggered_update(rn);
+		    metric > rn->metric) { 
+				rn->metric = metric;
+				rde_send_change_kroute(rn);
+				triggered_update(rn);
+				if (rn->metric == INFINITY)
+					route_start_garbage(rn);
+		} else if (e->nexthop.s_addr != rn->nexthop.s_addr &&
+		    metric == rn->metric) {
+			/* If the new metric is the same as the old one,
+			 * examine the timeout for the existing route.  If it
+			 * is at least halfway to the expiration point, switch
+			 * to the new route.
+			 */
+			timerclear(&tv);
+			gettimeofday(&now, NULL);
+			evtimer_pending(&rn->timeout_timer, &tv);
+			if (tv.tv_sec - now.tv_sec < ROUTE_TIMEOUT / 2) {
+				rn->nexthop.s_addr = e->nexthop.s_addr;
+				rn->ifindex = e->ifindex;
+				rde_send_change_kroute(rn);
+			}
 		}
 
-		if (e->nexthop.s_addr == rn->nexthop.s_addr)
+		if (e->nexthop.s_addr == rn->nexthop.s_addr &&
+		    rn->metric < INFINITY)
 			route_reset_timers(rn);
 	}
 
diff --git a/usr.sbin/ripd/rde.h b/usr.sbin/ripd/rde.h
index f27d561a8ae..429c5a91055 100644
--- a/usr.sbin/ripd/rde.h
+++ b/usr.sbin/ripd/rde.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde.h,v 1.1 2006/10/18 16:11:58 norby Exp $ */
+/*	$OpenBSD: rde.h,v 1.2 2007/04/09 20:45:52 michele Exp $ */
 
 /*
  * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it>
@@ -46,7 +46,7 @@ void		 rde_send_delete_kroute(struct rt_node *);
 int              rde_imsg_compose_ripe(int, u_int32_t, pid_t, void *,
 		     u_int16_t);
 
-/* rde_routes.c */
+/* rde_rib.c */
 void		 rt_init(void);
 int		 rt_compare(struct rt_node *, struct rt_node *);
 struct rt_node	*rt_find(in_addr_t, in_addr_t);
@@ -59,6 +59,7 @@ void		 rt_snap(u_int32_t);
 void             rt_clear(void);
 void		 route_reset_timers(struct rt_node *);
 int		 route_start_timeout(struct rt_node *);
+void		 route_start_garbage(struct rt_node *);
 void		 rt_dump(pid_t);
 
 #endif /* _RDE_H_ */
diff --git a/usr.sbin/ripd/rde_rib.c b/usr.sbin/ripd/rde_rib.c
index e26292ee953..ce10a480f73 100644
--- a/usr.sbin/ripd/rde_rib.c
+++ b/usr.sbin/ripd/rde_rib.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde_rib.c,v 1.1 2006/10/18 16:11:58 norby Exp $ */
+/*	$OpenBSD: rde_rib.c,v 1.2 2007/04/09 20:45:52 michele Exp $ */
 
 /*
  * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it>
@@ -44,7 +44,6 @@ RB_GENERATE(rt_tree, rt_node, entry, rt_compare)
 
 void	 route_action_timeout(int, short, void *);
 void	 route_action_garbage(int, short, void *);
-int	 route_start_timeout(struct rt_node *);
 
 /* timers */
 int
@@ -58,6 +57,21 @@ route_start_timeout(struct rt_node *rn)
 	return (evtimer_add(&rn->timeout_timer, &tv));
 }
 
+void
+route_start_garbage(struct rt_node *rn)
+{
+	struct timeval	 tv;
+
+	timerclear(&tv);
+	tv.tv_sec = ROUTE_GARBAGE;
+
+	if (evtimer_pending(&rn->timeout_timer, NULL)) {
+		if (evtimer_del(&rn->timeout_timer) == -1)
+			fatal("route_start_garbage");
+		evtimer_add(&rn->garbage_timer, &tv);
+	}
+}
+
 /* ARGSUSED */
 void
 route_action_timeout(int fd, short event, void *arg)
@@ -95,7 +109,7 @@ route_reset_timers(struct rt_node *r)
 	evtimer_del(&r->timeout_timer);
 	evtimer_del(&r->garbage_timer);
 
-	event_add(&r->timeout_timer, &tv);
+	evtimer_add(&r->timeout_timer, &tv);
 }
 
 /* route table */
diff --git a/usr.sbin/ripd/ripe.h b/usr.sbin/ripd/ripe.h
index 3c901901afe..8a7d2c70270 100644
--- a/usr.sbin/ripd/ripe.h
+++ b/usr.sbin/ripd/ripe.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ripe.h,v 1.5 2007/03/27 20:19:04 michele Exp $ */
+/*	$OpenBSD: ripe.h,v 1.6 2007/04/09 20:45:52 michele Exp $ */
 
 /*
  * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it>
@@ -73,12 +73,12 @@ struct nbr {
 	int			 flags;
 };
 
-/* packet */
+/* packet.c */
 int	 send_packet(struct iface *, void *, size_t, struct sockaddr_in *);
 void	 recv_packet(int, short, void *);
 int	 gen_rip_hdr(struct buf *, u_int8_t);
 
-/* interface */
+/* interface.c */
 void			 if_init(struct ripd_conf *, struct iface *);
 int			 if_fsm(struct iface *, enum iface_event);
 int			 if_set_mcast(struct iface *);