zebra: reinstate bgp route on local delete

Neigh detected duplicate detected during local update,
upon receiving kernel neigh delete, set neigh inactive
flag so BGPd can install remote route entry if present.

Only if freeze action enabled, local duplicate detected
entry will not be present in BGPd thus marking neigh
inactive is safe. BGPd will simply attempt install
remote entry if present.

Ticket:CM-23438
Testing Done:
Validated MAC-IP pair, trigger mobility of between two
VTEPs, upon local freeze perform neigh delete which
triggers BGP to install remote type-2 route into kernel.

Signed-off-by: Chirag Shah <chirag@cumulusnetworks.com>

diff --git a/zebra/zebra_vxlan.c b/zebra/zebra_vxlan.c
index 45e6caebbe9ce05fcb0e799d35e2128ea2f676ed..a7b689c12afd2a6e285b3c36aa474489e2d01a54 100644 (file)
--- a/zebra/zebra_vxlan.c
+++ b/zebra/zebra_vxlan.c
@@ -7024,6 +7024,7 @@ int zebra_vxlan_handle_kernel_neigh_del(struct interface *ifp,
        zebra_vni_t *zvni = NULL;
        zebra_mac_t *zmac = NULL;
        zebra_l3vni_t *zl3vni = NULL;
+       struct zebra_vrf *zvrf;
 
        /* check if this is a remote neigh entry corresponding to remote
         * next-hop
@@ -7076,9 +7077,23 @@ int zebra_vxlan_handle_kernel_neigh_del(struct interface *ifp,
                return 0;
        }
 
+       zvrf = vrf_info_lookup(zvni->vxlan_if->vrf_id);
+       if (!zvrf) {
+               zlog_debug("%s: VNI %u vrf lookup failed.",
+                                  __PRETTY_FUNCTION__, zvni->vni);
+               return -1;
+       }
+
+       /* In case of feeze action, if local neigh is in duplicate state,
+        * Mark the Neigh as inactive before sending delete request to BGPd,
+        * If BGPd has remote entry, it will re-install
+        */
+       if (zvrf->dad_freeze &&
+           CHECK_FLAG(n->flags, ZEBRA_NEIGH_DUPLICATE))
+           ZEBRA_NEIGH_SET_INACTIVE(n);
+
        /* Remove neighbor from BGP. */
-       zvni_neigh_send_del_to_client(zvni->vni, &n->ip, &n->emac,
-                       0, n->state);
+       zvni_neigh_send_del_to_client(zvni->vni, &n->ip, &n->emac, 0, n->state);
 
        /* Delete this neighbor entry. */
        zvni_neigh_del(zvni, n);