From 46ee012950e04dceb806b2c17f695628fbd9e186 Mon Sep 17 00:00:00 2001
From: renato <renato@openbsd.org>
Date: Sat, 10 Oct 2015 05:03:39 +0000
Subject: [PATCH] Fix detection of interface up/down events.

---
 usr.sbin/eigrpd/interface.c | 28 ++++++++++++++++++++--------
 usr.sbin/eigrpd/packet.c    | 13 ++++++++-----
 2 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/usr.sbin/eigrpd/interface.c b/usr.sbin/eigrpd/interface.c
index b7f4bec0dba..c233dedddc3 100644
--- a/usr.sbin/eigrpd/interface.c
+++ b/usr.sbin/eigrpd/interface.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: interface.c,v 1.3 2015/10/05 01:59:33 renato Exp $ */
+/*	$OpenBSD: interface.c,v 1.4 2015/10/10 05:03:39 renato Exp $ */
 
 /*
  * Copyright (c) 2015 Renato Westphal <renato@openbsd.org>
@@ -246,25 +246,37 @@ if_update(struct iface *iface, int af)
 {
 	struct eigrp_iface	*ei;
 	int			 link_ok;
+	int			 addr_ok = 1;
+	struct if_addr		*if_addr;
 
 	link_ok = (iface->flags & IFF_UP) &&
 	    LINK_STATE_IS_UP(iface->linkstate);
 
+	/*
+	 * NOTE: For EIGRPv4, each interface should have a valid IP address
+	 * otherwise they can not be enabled in the routing domain. For IPv6
+	 * this limitation does not exist because the link-local addresses
+	 * are used to form the adjacencies.
+	 */
+	if (af == AF_INET) {
+		TAILQ_FOREACH(if_addr, &iface->addr_list, entry)
+			if (if_addr->af == AF_INET)
+				break;
+		if (if_addr == NULL)
+			addr_ok = 0;
+	}
+
 	TAILQ_FOREACH(ei, &iface->ei_list, i_entry) {
 		if (af != AF_UNSPEC && ei->eigrp->af != af)
 			continue;
 
 		if (ei->state == IF_STA_DOWN) {
-			if (!link_ok)
-				continue;
-			if (af == AF_INET && TAILQ_EMPTY(&iface->addr_list))
+			if (!link_ok || !addr_ok)
 				continue;
 			ei->state = IF_STA_ACTIVE;
 			eigrp_if_start(ei);
-		} else {
-			if (link_ok)
-				continue;
-			if (!(af == AF_INET && TAILQ_EMPTY(&iface->addr_list)))
+		} else if (ei->state == IF_STA_ACTIVE) {
+			if (link_ok && addr_ok)
 				continue;
 			ei->state = IF_STA_DOWN;
 			eigrp_if_reset(ei);
diff --git a/usr.sbin/eigrpd/packet.c b/usr.sbin/eigrpd/packet.c
index 27a5f9e5c30..05a57f6db1e 100644
--- a/usr.sbin/eigrpd/packet.c
+++ b/usr.sbin/eigrpd/packet.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: packet.c,v 1.3 2015/10/04 23:08:57 renato Exp $ */
+/*	$OpenBSD: packet.c,v 1.4 2015/10/10 05:03:39 renato Exp $ */
 
 /*
  * Copyright (c) 2015 Renato Westphal <renato@openbsd.org>
@@ -707,10 +707,13 @@ find_iface(unsigned int ifindex, int af, union eigrpd_addr *src)
 		 * addresses for the subnet as known to the local router."
 		 */
 		TAILQ_FOREACH(if_addr, &iface->addr_list, entry) {
-			mask = prefixlen2mask(if_addr->prefixlen);
-			if ((if_addr->addr.v4.s_addr & mask) ==
-			    (src->v4.s_addr & mask))
-				return (iface);
+			if (if_addr->af == AF_INET) {
+				mask = prefixlen2mask(if_addr->prefixlen);
+
+				if ((if_addr->addr.v4.s_addr & mask) ==
+				    (src->v4.s_addr & mask))
+					return (iface);
+			}
 		}
 		break;
 	case AF_INET6:
-- 
2.20.1