bfd: Add an update API that has create new or modify existing semantics

Type: improvement

helps keep the agents stateless

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I3588f13c081e24f5a8083b490eb02856361e4ccb
diff --git a/src/vnet/bfd/bfd_api.h b/src/vnet/bfd/bfd_api.h
index 2a6c69b..f051e6b 100644
--- a/src/vnet/bfd/bfd_api.h
+++ b/src/vnet/bfd/bfd_api.h
@@ -45,6 +45,15 @@
 		     u8 bfd_key_id);
 
 /**
+ * @brief create a new or modify and existing bfd session
+ */
+vnet_api_error_t
+bfd_udp_upd_session (u32 sw_if_index, const ip46_address_t *local_addr,
+		     const ip46_address_t *peer_addr, u32 desired_min_tx_usec,
+		     u32 required_min_rx_usec, u8 detect_mult,
+		     u8 is_authenticated, u32 conf_key_id, u8 bfd_key_id);
+
+/**
  * @brief modify existing session
  */
 vnet_api_error_t