+/**
+ * listener events
+ */
+#define foreach_bfd_listen_event(F) \
+ F (CREATE, "sesion-created") \
+ F (UPDATE, "session-updated") \
+ F (DELETE, "session-deleted")
+
+typedef enum
+{
+#define F(sym, str) BFD_LISTEN_EVENT_##sym,
+ foreach_bfd_listen_event (F)
+#undef F
+} bfd_listen_event_e;
+
+/**
+ * session nitification call back function type
+ */
+typedef void (*bfd_notify_fn_t) (bfd_listen_event_e, const bfd_session_t *);
+