From 67d7c717dd65d1db30734cb3751972b03380c5e8 Mon Sep 17 00:00:00 2001
From: Claudio Jeker <claudio@cvs.openbsd.org>
Date: Wed, 4 Jul 2012 20:43:27 +0000
Subject: Seems like I missed to adjust the route decision code to cover the
 things that need to be checked because of route reflection. Do this now and
 reference the new RR RFC in the man page. OK henning@ sthen@

---
 usr.sbin/bgpd/bgpd.8       | 14 +++++++-------
 usr.sbin/bgpd/rde_decide.c | 36 ++++++++++++++++++++++++++++--------
 2 files changed, 35 insertions(+), 15 deletions(-)

(limited to 'usr.sbin')

diff --git a/usr.sbin/bgpd/bgpd.8 b/usr.sbin/bgpd/bgpd.8
index a2ce726af25..47129c9ab45 100644
--- a/usr.sbin/bgpd/bgpd.8
+++ b/usr.sbin/bgpd/bgpd.8
@@ -1,4 +1,4 @@
-.\" $OpenBSD: bgpd.8,v 1.41 2012/06/10 11:16:08 claudio Exp $
+.\" $OpenBSD: bgpd.8,v 1.42 2012/07/04 20:43:26 claudio Exp $
 .\"
 .\" Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: June 10 2012 $
+.Dd $Mdocdate: July 4 2012 $
 .Dt BGPD 8
 .Os
 .Sh NAME
@@ -157,11 +157,6 @@ control socket
 .%D March 1999
 .Re
 .Rs
-.%R RFC 2796
-.%T "BGP Route Reflection - An Alternative to Full Mesh IBGP"
-.%D April 2000
-.Re
-.Rs
 .%R RFC 2918
 .%T "Route Refresh Capability for BGP-4"
 .%D September 2000
@@ -187,6 +182,11 @@ control socket
 .%D February 2006
 .Re
 .Rs
+.%R RFC 4456
+.%T "BGP Route Reflection - An Alternative to Full Mesh IBGP"
+.%D April 2006
+.Re
+.Rs
 .%R RFC 4486
 .%T "BGP Cease Notification Message Subcodes"
 .%D April 2006
diff --git a/usr.sbin/bgpd/rde_decide.c b/usr.sbin/bgpd/rde_decide.c
index 19c9162d721..f58d4b7d528 100644
--- a/usr.sbin/bgpd/rde_decide.c
+++ b/usr.sbin/bgpd/rde_decide.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rde_decide.c,v 1.61 2012/04/12 17:31:05 claudio Exp $ */
+/*	$OpenBSD: rde_decide.c,v 1.62 2012/07/04 20:43:26 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Claudio Jeker <claudio@openbsd.org>
@@ -109,6 +109,9 @@ int
 prefix_cmp(struct prefix *p1, struct prefix *p2)
 {
 	struct rde_aspath	*asp1, *asp2;
+	struct attr		*a;
+	u_int32_t		 p1id, p2id;
+	int			 p1cnt, p2cnt;
 
 	if (p1 == NULL)
 		return (-1);
@@ -187,13 +190,30 @@ prefix_cmp(struct prefix *p1, struct prefix *p2)
 		if ((p2->lastchange - p1->lastchange) != 0)
 			return (p2->lastchange - p1->lastchange);
 
-	/* 10. lowest BGP Id wins */
-	if ((p2->aspath->peer->remote_bgpid -
-	    p1->aspath->peer->remote_bgpid) != 0)
-		return (p2->aspath->peer->remote_bgpid -
-		    p1->aspath->peer->remote_bgpid);
+	/* 10. lowest BGP Id wins, use ORIGINATOR_ID if present */
+	if ((a = attr_optget(asp1, ATTR_ORIGINATOR_ID)) != NULL) {
+		memcpy(&p1id, a->data, sizeof(p1id));
+		p1id = ntohl(p1id);
+	} else
+		p1id = asp1->peer->remote_bgpid;
+	if ((a = attr_optget(asp2, ATTR_ORIGINATOR_ID)) != NULL) {
+		memcpy(&p2id, a->data, sizeof(p2id));
+		p2id = ntohl(p2id);
+	} else
+		p2id = asp2->peer->remote_bgpid;
+	if ((p2id - p1id) != 0)
+		return (p2id - p1id);
 
-	/* 11. lowest peer address wins (IPv4 is better than IPv6) */
+	/* 11. compare CLUSTER_LIST length, shorter is better */
+	p1cnt = p2cnt = 0;
+	if ((a = attr_optget(asp1, ATTR_CLUSTER_LIST)) != NULL)
+		p1cnt = a->len / sizeof(u_int32_t);
+	if ((a = attr_optget(asp2, ATTR_CLUSTER_LIST)) != NULL)
+		p2cnt = a->len / sizeof(u_int32_t);
+	if ((p2cnt - p1cnt) != 0)
+		return (p2cnt - p1cnt);
+
+	/* 12. lowest peer address wins (IPv4 is better than IPv6) */
 	if (memcmp(&p1->aspath->peer->remote_addr,
 	    &p2->aspath->peer->remote_addr,
 	    sizeof(p1->aspath->peer->remote_addr)) != 0)
@@ -201,7 +221,7 @@ prefix_cmp(struct prefix *p1, struct prefix *p2)
 		    &p2->aspath->peer->remote_addr,
 		    sizeof(p1->aspath->peer->remote_addr)));
 
-	/* 12. for announced prefixes prefer dynamic routes */
+	/* 13. for announced prefixes prefer dynamic routes */
 	if ((asp1->flags & F_ANN_DYNAMIC) != (asp2->flags & F_ANN_DYNAMIC)) {
 		if (asp1->flags & F_ANN_DYNAMIC)
 			return (1);
-- 
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