From afbb1c59a3b4dbbe41b1869642b31e39fb0136d2 Mon Sep 17 00:00:00 2001
From: Lou Berger <lberger@labn.net>
Date: Fri, 7 Oct 2016 09:44:42 -0400
Subject: [PATCH] bgp: ignore NHT when bgpd has never connected to zebra

---
 bgpd/bgp_nht.c   |  4 +++-
 bgpd/bgp_zebra.c | 12 ++++++++++++
 bgpd/bgp_zebra.h |  2 ++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index ef70d0e4f9..d1f7fe341e 100644
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -41,6 +41,7 @@
 #include "bgpd/bgp_debug.h"
 #include "bgpd/bgp_nht.h"
 #include "bgpd/bgp_fsm.h"
+#include "bgpd/bgp_zebra.h"
 
 extern struct zclient *zclient;
 
@@ -234,7 +235,8 @@ bgp_find_or_add_nexthop (struct bgp *bgp, afi_t afi, struct bgp_info *ri,
   else if (peer)
     bnc->nht_info = (void *)peer;
 
-  return (CHECK_FLAG(bnc->flags, BGP_NEXTHOP_VALID));
+  return (bgp_zebra_num_connects() == 0 ||
+          CHECK_FLAG(bnc->flags, BGP_NEXTHOP_VALID));
 }
 
 void
diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c
index 789dba53f8..11e888d7e9 100644
--- a/bgpd/bgp_zebra.c
+++ b/bgpd/bgp_zebra.c
@@ -109,6 +109,8 @@ bgp_install_info_to_zebra (struct bgp *bgp)
   return 1;
 }
 
+int zclient_num_connects;
+
 /* Router-id update message from zebra. */
 static int
 bgp_router_id_update (int command, struct zclient *zclient, zebra_size_t length,
@@ -2087,6 +2089,8 @@ bgp_zebra_connected (struct zclient *zclient)
 {
   struct bgp *bgp;
 
+  zclient_num_connects++;       /* increment even if not responding */
+
   /* At this point, we may or may not have BGP instances configured, but
    * we're only interested in the default VRF (others wouldn't have learnt
    * the VRF from Zebra yet.)
@@ -2109,6 +2113,8 @@ bgp_zebra_connected (struct zclient *zclient)
 void
 bgp_zebra_init (struct thread_master *master)
 {
+  zclient_num_connects = 0;
+
   /* Set default values. */
   zclient = zclient_new (master);
   zclient_init (zclient, ZEBRA_ROUTE_BGP, 0);
@@ -2143,3 +2149,9 @@ bgp_zebra_destroy(void)
   zclient_free(zclient);
   zclient = NULL;
 }
+
+int
+bgp_zebra_num_connects(void)
+{
+  return zclient_num_connects;
+}
diff --git a/bgpd/bgp_zebra.h b/bgpd/bgp_zebra.h
index af921af82f..24b4634eb6 100644
--- a/bgpd/bgp_zebra.h
+++ b/bgpd/bgp_zebra.h
@@ -62,4 +62,6 @@ extern struct interface *if_lookup_by_ipv6 (struct in6_addr *, ifindex_t, vrf_id
 extern struct interface *if_lookup_by_ipv6_exact (struct in6_addr *, ifindex_t, vrf_id_t);
 #endif /* HAVE_IPV6 */
 
+extern int bgp_zebra_num_connects(void);
+
 #endif /* _QUAGGA_BGP_ZEBRA_H */
-- 
2.39.5