Allow NO_SUCH_ENTRY to count as successful 'removal' of neighbors. Wh…

…en an address is removed, VPP will invalidate the neighbor cache. This change allows the subsequent gratutious neigh deletion from Linux to be harmless.

lcpng_nl_sync.c

@@ -272,16 +272,16 @@ lcp_nl_neigh_del (struct rtnl_neigh *rn)
   lcp_nl_mk_ip_addr (rtnl_neigh_get_dst (rn), &nh);
   rv = ip_neighbor_del (&nh, lip->lip_phy_sw_if_index);
 
-  if (rv)
-    {
-      NL_ERROR ("neigh_del: Failed %U iface %U", format_ip_address, &nh,
-		format_vnet_sw_if_index_name, vnet_get_main (),
-		lip->lip_phy_sw_if_index);
-    }
-  else
+  if (rv == 0 || rv == VNET_API_ERROR_NO_SUCH_ENTRY)
     {
       NL_NOTICE ("neigh_del: Deleted %U iface %U", format_ip_address, &nh,
 		 format_vnet_sw_if_index_name, vnet_get_main (),
 		 lip->lip_phy_sw_if_index);
     }
+  else
+    {
+      NL_ERROR ("neigh_del: Failed %U iface %U", format_ip_address, &nh,
+		format_vnet_sw_if_index_name, vnet_get_main (),
+		lip->lip_phy_sw_if_index);
+    }
 }