bgpd: Exclude case for remote prefix w/o link-local

If we expand the truth (A || B) to "(A && B) || (A && !B) || (!A && B)" so that we can isolate the case (!A && B), we then add the additional check (C) to ensure that original route actually has a link-local hext-hop Signed-off-by: Richard Cunningham <[email protected]>
FRRouting · Aug 29, 2024 · 5f6a61f · 5f6a61f
1 parent 77e1a26
commit 5f6a61f
Showing 1 changed file with 10 additions and 7 deletions.
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
@@ -2472,13 +2472,16 @@ bool subgroup_announce_check(struct bgp_dest *dest, struct bgp_path_info *pi,
 	if (NEXTHOP_IS_V6) {
 		attr->mp_nexthop_len = BGP_ATTR_NHLEN_IPV6_GLOBAL;
 		if ((CHECK_FLAG(peer->af_flags[afi][safi],
-				PEER_FLAG_NEXTHOP_LOCAL_UNCHANGED)
-		     && IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_local))
-		    || (!reflect && !transparent
-			&& IN6_IS_ADDR_LINKLOCAL(&peer->nexthop.v6_local)
-			&& peer->shared_network
-			&& (from == bgp->peer_self
-			    || peer->sort == BGP_PEER_EBGP))) {
+				PEER_FLAG_NEXTHOP_LOCAL_UNCHANGED) &&
+		     IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_local)) ||
+		    (!reflect && !transparent &&
+		     IN6_IS_ADDR_LINKLOCAL(&peer->nexthop.v6_local) &&
+		     peer->shared_network &&
+		     ((from == bgp->peer_self && peer->sort == BGP_PEER_EBGP) ||
+		      (from == bgp->peer_self && peer->sort != BGP_PEER_EBGP) ||
+		      (from != bgp->peer_self &&
+		       IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_local) &&
+		       peer->sort == BGP_PEER_EBGP)))) {
 			if (safi == SAFI_MPLS_VPN)
 				attr->mp_nexthop_len =
 					BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL;