From 7ed7713848b697947b27f4e1eddc398740610e94 Mon Sep 17 00:00:00 2001
From: christos <christos@NetBSD.org>
Date: Sat, 27 Mar 2004 20:50:43 +0000
Subject: [PATCH] From Vernon Schryver:

Wolfgang Solfrank has explained the problem with router discovery
in `routed` in a way I can understand.

Let's assume that the configured preference of the interface is 5.
This gets converted to 0x80000005 through the use of the UNSIGN_PREF
macro.  Later on, this value gets put into the PREF macro, which
compares it against the interface metric(s) (let's assume those
values to be 0 for now).  Of course the 0x80000005, cast to int,
is much less than 0, so the clamping rule is triggered, which
gives us a value of 1.  This is then converted via SIGN_PREF into
0x80000001 and put into the message.  Certainly, this isn't what
was intended.
---
 sbin/routed/main.c   |  6 +++---
 sbin/routed/rdisc.c  | 11 ++++++-----
 sbin/routed/routed.8 |  5 ++---
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/sbin/routed/main.c b/sbin/routed/main.c
index 7fc89ca45769..927c1d33aca2 100644
--- a/sbin/routed/main.c
+++ b/sbin/routed/main.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: main.c,v 1.35 2003/11/14 01:31:24 enami Exp $	*/
+/*	$NetBSD: main.c,v 1.36 2004/03/27 20:50:43 christos Exp $	*/
 
 /*
  * Copyright (c) 1983, 1988, 1993
@@ -46,7 +46,7 @@ __COPYRIGHT("@(#) Copyright (c) 1983, 1988, 1993\n"
 	    "The Regents of the University of California."
 	    "  All rights reserved.\n");
 #ifdef __NetBSD__
-__RCSID("$NetBSD: main.c,v 1.35 2003/11/14 01:31:24 enami Exp $");
+__RCSID("$NetBSD: main.c,v 1.36 2004/03/27 20:50:43 christos Exp $");
 #elif defined(__FreeBSD__)
 __RCSID("$FreeBSD$");
 #else
@@ -226,7 +226,7 @@ main(int argc,
 		case 'v':
 			/* display version */
 			verbose++;
-			msglog("version 2.25");
+			msglog("version 2.28");
 			break;
 
 		default:
diff --git a/sbin/routed/rdisc.c b/sbin/routed/rdisc.c
index 9f9c05b767c4..24bbdb6e0bba 100644
--- a/sbin/routed/rdisc.c
+++ b/sbin/routed/rdisc.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: rdisc.c,v 1.14 2002/11/30 04:04:23 christos Exp $	*/
+/*	$NetBSD: rdisc.c,v 1.15 2004/03/27 20:50:43 christos Exp $	*/
 
 /*
  * Copyright (c) 1995
@@ -39,7 +39,7 @@
 #include <netinet/ip_icmp.h>
 
 #ifdef __NetBSD__
-__RCSID("$NetBSD: rdisc.c,v 1.14 2002/11/30 04:04:23 christos Exp $");
+__RCSID("$NetBSD: rdisc.c,v 1.15 2004/03/27 20:50:43 christos Exp $");
 #elif defined(__FreeBSD__)
 __RCSID("$FreeBSD$");
 #else
@@ -99,9 +99,10 @@ struct dr {				/* accumulated advertisements */
 #define UNSIGN_PREF(p) SIGN_PREF(p)
 /* adjust unsigned preference by interface metric,
  * without driving it to infinity */
-#define PREF(p, ifp) ((int)(p) <= ((ifp)->int_metric+(ifp)->int_adj_outmetric)\
-		      ? ((p) != 0 ? 1 : 0)				    \
-		      : (p) - ((ifp)->int_metric+(ifp)->int_adj_outmetric))
+#define PREF(p, ifp) ((n_long)(p) <= (n_long)((ifp)->int_metric		\
+				      + (ifp)->int_adj_outmetric)	\
+		      ? ((p) != 0 ? 1 : 0)				\
+		      : (p) - ((ifp)->int_metric + (ifp)->int_adj_outmetric))
 
 static void rdisc_sort(void);
 
diff --git a/sbin/routed/routed.8 b/sbin/routed/routed.8
index 8926b05aac43..e5bff5b3f11c 100644
--- a/sbin/routed/routed.8
+++ b/sbin/routed/routed.8
@@ -1,4 +1,4 @@
-.\"	$NetBSD: routed.8,v 1.42 2003/09/07 16:22:23 wiz Exp $
+.\"	$NetBSD: routed.8,v 1.43 2004/03/27 20:50:43 christos Exp $
 .\"
 .\" Copyright (c) 1983, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -640,8 +640,7 @@ sets the preference in Router Discovery Advertisements to the optionally
 signed integer
 .Ar N .
 The default preference is 0.
-Default routes with smaller or more negative preferences are preferred by
-clients.
+Default routes with larger preferences are preferred by clients.
 .It Cm rdisc_interval Ns \&= Ns Ar N
 sets the nominal interval with which Router Discovery Advertisements
 are transmitted to N seconds and their lifetime to 3*N.