From: Don Slice <dslice@cumulusnetworks.com>
Date: Tue, 25 Sep 2018 13:22:22 +0000 (-0700)
Subject: bgpd: allow nht registration on ipv6 link-local addresses
X-Git-Tag: frr-7.1-dev~290^2
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=687a2b5dcccd7d7b288b7a00fcc6f39130f471e0;p=mirror%2Ffrr.git

bgpd: allow nht registration on ipv6 link-local addresses

Signed-off-by: Don Slice <dslice@cumulusnetworks.com>
Testing Done: bgp-smoke completed with no new failures

While testing 5549 support using global addresses, discovered that
ipv6 nexthop tracking thru a route-reflector didn't work.  Since
the next-hop used for remote nexthops resolves to the link-local
of the route-reflector, we need to track it in order to react to
interface down events.  Also tripped over a crash in certain cases
which is also resolved in this fix.
---

diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index dd1ffe9f3b..c94c707157 100644
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -169,11 +169,6 @@ int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
 		if (make_prefix(afi, ri, &p) < 0)
 			return 1;
 	} else if (peer) {
-		/* Don't register link local NH */
-		if (afi == AFI_IP6
-		    && IN6_IS_ADDR_LINKLOCAL(&peer->su.sin6.sin6_addr))
-			return 1;
-
 		if (!sockunion2hostprefix(&peer->su, &p)) {
 			if (BGP_DEBUG(nht, NHT)) {
 				zlog_debug(
@@ -287,10 +282,6 @@ void bgp_delete_connected_nexthop(afi_t afi, struct peer *peer)
 	if (!peer)
 		return;
 
-	/* We don't register link local address for NHT */
-	if (afi == AFI_IP6 && IN6_IS_ADDR_LINKLOCAL(&peer->su.sin6.sin6_addr))
-		return;
-
 	if (!sockunion2hostprefix(&peer->su, &p))
 		return;
 
@@ -437,8 +428,9 @@ void bgp_parse_nexthop_update(int command, vrf_id_t vrf_id)
 			 * we receive from bgp.  This is to allow us
 			 * to work with v4 routing over v6 nexthops
 			 */
-			if (peer &&
-			    CHECK_FLAG(peer->flags, PEER_FLAG_CAPABILITY_ENHE)
+			if (peer && !peer->ifp
+			    && CHECK_FLAG(peer->flags,
+					  PEER_FLAG_CAPABILITY_ENHE)
 			    && nhr.prefix.family == AF_INET6) {
 				struct interface *ifp;
 
@@ -556,11 +548,6 @@ static int make_prefix(int afi, struct bgp_info *ri, struct prefix *p)
 		}
 		break;
 	case AFI_IP6:
-		/* We don't register link local NH */
-		if (ri->attr->mp_nexthop_len != BGP_ATTR_NHLEN_IPV6_GLOBAL
-		    || IN6_IS_ADDR_LINKLOCAL(&ri->attr->mp_nexthop_global))
-			return -1;
-
 		p->family = AF_INET6;
 
 		if (is_bgp_static) {