The kernel uses rtm_addrs as a bit field for addresses that are

included in the routing message.  The significance of the bits has
to be consistent with the order of the addresss.  In route(8) store
addresses in ascending order of RTA values.  This allows to use
MPLS routes together with route labels.
OK mpi@ claudio@

1 files changed, 4 insertions, 3 deletions

diff --git a/sbin/route/route.c b/sbin/route/route.c
index bd57fae5324..1ee0b197a3f 100644
--- a/sbin/route/route.c
+++ b/sbin/route/route.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: route.c,v 1.231 2019/08/29 14:28:34 bluhm Exp $	*/
+/*	$OpenBSD: route.c,v 1.232 2019/08/29 22:42:16 bluhm Exp $	*/
 /*	$NetBSD: route.c,v 1.16 1996/04/15 18:27:05 cgd Exp $	*/
 
 /*
@@ -68,7 +68,7 @@
 const struct if_status_description
 			if_status_descriptions[] = LINK_STATE_DESCRIPTIONS;
 
-union sockunion so_dst, so_gate, so_mask, so_ifa, so_ifp, so_label, so_src;
+union sockunion so_dst, so_gate, so_mask, so_ifa, so_ifp, so_src, so_label;
 
 typedef union sockunion *sup;
 pid_t	pid;
@@ -1087,13 +1087,14 @@ rtmsg(int cmd, int flags, int fmask, uint8_t prio)
 
 	if (rtm_addrs & RTA_NETMASK)
 		mask_addr(&so_dst, &so_mask, RTA_DST);
+	/* store addresses in ascending order of RTA values */
 	NEXTADDR(RTA_DST, so_dst);
 	NEXTADDR(RTA_GATEWAY, so_gate);
 	NEXTADDR(RTA_NETMASK, so_mask);
 	NEXTADDR(RTA_IFP, so_ifp);
 	NEXTADDR(RTA_IFA, so_ifa);
-	NEXTADDR(RTA_LABEL, so_label);
 	NEXTADDR(RTA_SRC, so_src);
+	NEXTADDR(RTA_LABEL, so_label);
 	rtm.rtm_msglen = l = cp - (char *)&m_rtmsg;
 	if (verbose)
 		print_rtmsg(&rtm, l);