zebra: Reinstall remote VTEP next hop when it becomes stale

When a remote VTEP next hop entry (for symmetric routing) becomes
stale, reinstall it. This makes the behavior the same as what is
done for remote host next hops (for asymmetric routing and ARP
suppression).

Signed-off-by: Vivek Venkatraman <vivek@cumulusnetworks.com>

diff --git a/zebra/zebra_vxlan.c b/zebra/zebra_vxlan.c
index 5e0ef54a390c060f2536ac3b65904eadac59157a..f92855426964385a3e410dbf6440140512e3c108 100644 (file)
--- a/zebra/zebra_vxlan.c
+++ b/zebra/zebra_vxlan.c
@@ -3203,6 +3203,27 @@ static int zl3vni_remote_nh_del(zebra_l3vni_t *zl3vni,
        return 0;
 }
 
+/* handle neigh update from kernel - the only thing of interest is to
+ * readd stale entries.
+ */
+static int zl3vni_local_nh_add_update(zebra_l3vni_t *zl3vni,
+                                     struct ipaddr *ip, u_int16_t state)
+{
+       zebra_neigh_t *n = NULL;
+
+       n = zl3vni_nh_lookup(zl3vni, ip);
+       if (!n)
+               return 0;
+
+       /* all next hop neigh are remote and installed by frr.
+        * If the kernel has aged this entry, re-install.
+        */
+       if (state & NUD_STALE)
+               zl3vni_nh_install(zl3vni, n);
+
+       return 0;
+}
+
 /* handle neigh delete from kernel */
 static int zl3vni_local_nh_del(zebra_l3vni_t *zl3vni,
                               struct ipaddr *ip)
@@ -4581,6 +4602,14 @@ int zebra_vxlan_local_neigh_add_update(struct interface *ifp,
        zebra_vni_t *zvni = NULL;
        zebra_neigh_t *n = NULL;
        zebra_mac_t *zmac = NULL, *old_zmac = NULL;
+       zebra_l3vni_t *zl3vni = NULL;
+
+       /* check if this is a remote neigh entry corresponding to remote
+        * next-hop
+        */
+       zl3vni = zl3vni_from_svi(ifp, link_if);
+       if (zl3vni)
+               return zl3vni_local_nh_add_update(zl3vni, ip, state);
 
        /* We are only interested in neighbors on an SVI that resides on top
         * of a VxLAN bridge.