ip-neighbor: add api for getting neighbor db config

There is an API call to change neighbor database configuration (i.e.
limit on peer number, aging, and recycling). With this change, make
getting current values of these settings available via the API.

Type: improvement

Change-Id: Ie9394e086b68cf9b28ad98dea162f203f8043cbb
Signed-off-by: Alexander Chernavin <achernavin@netgate.com>
diff --git a/src/vnet/ip-neighbor/ip_neighbor.h b/src/vnet/ip-neighbor/ip_neighbor.h
index 8c07df8..cc888ba 100644
--- a/src/vnet/ip-neighbor/ip_neighbor.h
+++ b/src/vnet/ip-neighbor/ip_neighbor.h
@@ -36,6 +36,8 @@
 
 extern int ip_neighbor_config (ip_address_family_t af,
 			       u32 limit, u32 age, bool recycle);
+extern int ip_neighbor_get_config (ip_address_family_t af, u32 *limit,
+				   u32 *age, bool *recycle);
 
 extern void ip_neighbor_del_all (ip_address_family_t af, u32 sw_if_index);