bgpd: Cleanup NHT state when underlying VRF goes down

When the underlying VRF is deleted, ensure that state for the
next hops that BGP registers with zebra for tracking purposes is
properly updated. Otherwise BGP will not re-register the next hop
when the VRF is re-created, resulting in the next hop staying
unresolved.

Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>
Reviewed-by:   Don Slice <dslice@cumulusnetworks.com>
Ticket: CM-17456
Reviewed By: CCR-6587
Testing Done: Manual, bgp-min, vrf

diff --git a/bgpd/bgp_nht.c b/bgpd/bgp_nht.c
index 3a7a60b14d368d97576fc43339f21d743244c63e..55a2f10132453a8b9cb982bcd7f15e7451497c55 100644 (file)
--- a/bgpd/bgp_nht.c
+++ b/bgpd/bgp_nht.c
@@ -482,6 +482,33 @@ void bgp_parse_nexthop_update(int command, vrf_id_t vrf_id)
        evaluate_paths(bnc);
 }
 
+/*
+ * Cleanup nexthop registration and status information for BGP nexthops
+ * pertaining to this VRF. This is invoked upon VRF deletion.
+ */
+void bgp_cleanup_nexthops(struct bgp *bgp)
+{
+       afi_t afi;
+       struct bgp_node *rn;
+       struct bgp_nexthop_cache *bnc;
+
+       for (afi = AFI_IP; afi < AFI_MAX; afi++) {
+               if (!bgp->nexthop_cache_table[afi])
+                       continue;
+
+               for (rn = bgp_table_top(bgp->nexthop_cache_table[afi]); rn;
+                    rn = bgp_route_next(rn)) {
+                       if ((bnc = rn->info) == NULL)
+                               continue;
+
+                       /* Clear relevant flags. */
+                       UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
+                       UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
+                       UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED);
+               }
+       }
+}
+
 /**
  * make_prefix - make a prefix structure from the path (essentially
  * path's node.

diff --git a/bgpd/bgp_nht.h b/bgpd/bgp_nht.h
index f649bb225963012dd47456ec0a1fb9d95c23bf68..4b297f410c80f3102ca574883546e61fb8f475a4 100644 (file)
--- a/bgpd/bgp_nht.h
+++ b/bgpd/bgp_nht.h
@@ -66,4 +66,10 @@ void bgp_unlink_nexthop_by_peer(struct peer *);
  */
 extern void bgp_delete_connected_nexthop(afi_t afi, struct peer *peer);
 
+/*
+ * Cleanup nexthop registration and status information for BGP nexthops
+ * pertaining to this VRF. This is invoked upon VRF deletion.
+ */
+extern void bgp_cleanup_nexthops(struct bgp *bgp);
+
 #endif /* _BGP_NHT_H */

diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index c58e4e70cd726721a9afdd884785b8bdfaab1715..a017c4fa263b02929caf314d4fc269f62d1acbfc 100644 (file)
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -3031,6 +3031,9 @@ void bgp_instance_down(struct bgp *bgp)
 
        /* Purge network and redistributed routes. */
        bgp_purge_static_redist_routes(bgp);
+
+       /* Cleanup registered nexthops (flags) */
+       bgp_cleanup_nexthops(bgp);
 }
 
 /* Delete BGP instance. */