Merge pull request #4846 from vivek-cumulus/rfc-5549-gua-fix-ra

Fix nexthop reg and RA enable for IPv4 route exchange using GUA IPv6 peering

2 files changed, 35 insertions, 14 deletions

diff --git a/bgpd/bgp_fsm.c b/bgpd/bgp_fsm.c
index 4348e6b24..c9c6fc157 100644
--- a/bgpd/bgp_fsm.c
+++ b/bgpd/bgp_fsm.c
@@ -96,6 +96,21 @@ static int bgp_holdtime_timer(struct thread *);
 /* BGP FSM functions. */
 static int bgp_start(struct peer *);
 
+/* Register peer with NHT */
+static int bgp_peer_reg_with_nht(struct peer *peer)
+{
+	int connected = 0;
+
+	if (peer->sort == BGP_PEER_EBGP && peer->ttl == 1
+	    && !CHECK_FLAG(peer->flags, PEER_FLAG_DISABLE_CONNECTED_CHECK)
+	    && !bgp_flag_check(peer->bgp, BGP_FLAG_DISABLE_NH_CONNECTED_CHK))
+		connected = 1;
+
+	return bgp_find_or_add_nexthop(
+		peer->bgp, peer->bgp, family2afi(peer->su.sa.sa_family),
+		NULL, peer, connected);
+}
+
 static void peer_xfer_stats(struct peer *peer_dst, struct peer *peer_src)
 {
 	/* Copy stats over. These are only the pre-established state stats */
@@ -293,6 +308,11 @@ static struct peer *peer_xfer_conn(struct peer *from_peer)
 	if (from_peer)
 		peer_xfer_stats(peer, from_peer);
 
+	/* Register peer for NHT. This is to allow RAs to be enabled when
+	 * needed, even on a passive connection.
+	 */
+	bgp_peer_reg_with_nht(peer);
+
 	bgp_reads_on(peer);
 	bgp_writes_on(peer);
 	thread_add_timer_msec(bm->master, bgp_process_packet, peer, 0,
@@ -1382,7 +1402,6 @@ static int bgp_connect_fail(struct peer *peer)
 int bgp_start(struct peer *peer)
 {
 	int status;
-	int connected = 0;
 
 	bgp_peer_conf_if_to_su_update(peer);
 
@@ -1439,17 +1458,10 @@ int bgp_start(struct peer *peer)
 		return -1;
 	}
 
-	/* Register to be notified on peer up */
-	if (peer->sort == BGP_PEER_EBGP && peer->ttl == 1
-	    && !CHECK_FLAG(peer->flags, PEER_FLAG_DISABLE_CONNECTED_CHECK)
-	    && !bgp_flag_check(peer->bgp, BGP_FLAG_DISABLE_NH_CONNECTED_CHK))
-		connected = 1;
-	else
-		connected = 0;
-
-	if (!bgp_find_or_add_nexthop(peer->bgp, peer->bgp,
-				     family2afi(peer->su.sa.sa_family), NULL,
-				     peer, connected)) {
+	/* Register peer for NHT. If next hop is already resolved, proceed
+	 * with connection setup, else wait.
+	 */
+	if (!bgp_peer_reg_with_nht(peer)) {
 		if (bgp_zebra_num_connects()) {
 			if (bgp_debug_neighbor_events(peer))
 				zlog_debug("%s [FSM] Waiting for NHT",
diff --git a/bgpd/bgp_nexthop.c b/bgpd/bgp_nexthop.c
index a8c507832..812f0ce16 100644
--- a/bgpd/bgp_nexthop.c
+++ b/bgpd/bgp_nexthop.c
@@ -680,17 +680,23 @@ static void bgp_show_nexthops(struct vty *vty, struct bgp *bgp, int detail,
 			continue;
 		for (rn = bgp_table_top(table[afi]); rn;
 		     rn = bgp_route_next(rn)) {
+			struct peer *peer;
+
 			bnc = bgp_node_get_bgp_nexthop_info(rn);
 			if (!bnc)
 				continue;
+			peer = (struct peer *)bnc->nht_info;
 
 			if (CHECK_FLAG(bnc->flags, BGP_NEXTHOP_VALID)) {
 				vty_out(vty,
-					" %s valid [IGP metric %d], #paths %d\n",
+					" %s valid [IGP metric %d], #paths %d",
 					inet_ntop(rn->p.family,
 						  &rn->p.u.prefix, buf,
 						  sizeof(buf)),
 					bnc->metric, bnc->path_count);
+				if (peer)
+					vty_out(vty, ", peer %s", peer->host);
+				vty_out(vty, "\n");
 
 				if (!detail)
 					continue;
@@ -698,10 +704,13 @@ static void bgp_show_nexthops(struct vty *vty, struct bgp *bgp, int detail,
 				bgp_show_nexthops_detail(vty, bgp, bnc);
 
 			} else {
-				vty_out(vty, " %s invalid\n",
+				vty_out(vty, " %s invalid",
 					inet_ntop(rn->p.family,
 						  &rn->p.u.prefix, buf,
 						  sizeof(buf)));
+				if (peer)
+					vty_out(vty, ", peer %s", peer->host);
+				vty_out(vty, "\n");
 				if (CHECK_FLAG(bnc->flags,
 					       BGP_NEXTHOP_CONNECTED))
 					vty_out(vty, "  Must be Connected\n");