+#define snat_is_unk_proto_session(s) (s->flags & SNAT_SESSION_FLAG_UNKNOWN_PROTO)
+
+/** \brief Check if NAT session is twice NAT.
+ @param s NAT session
+ @return 1 if NAT session is twice NAT
+*/
+#define is_twice_nat_session(s) (s->flags & SNAT_SESSION_FLAG_TWICE_NAT)
+
+/** \brief Check if NAT session is load-balancing.
+ @param s NAT session
+ @return 1 if NAT session is load-balancing
+*/
+#define is_lb_session(s) (s->flags & SNAT_SESSION_FLAG_LOAD_BALANCING)
+
+/** \brief Check if NAT session is forwarding bypass.
+ @param s NAT session
+ @return 1 if NAT session is load-balancing
+*/
+#define is_fwd_bypass_session(s) (s->flags & SNAT_SESSION_FLAG_FWD_BYPASS)
+
+/** \brief Check if NAT session is endpoint dependent.
+ @param s NAT session
+ @return 1 if NAT session is endpoint dependent
+*/
+#define is_ed_session(s) (s->flags & SNAT_SESSION_FLAG_ENDPOINT_DEPENDENT)
+
+#define nat_interface_is_inside(i) i->flags & NAT_INTERFACE_FLAG_IS_INSIDE
+#define nat_interface_is_outside(i) i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE
+
+#define nat_log_err(...) \
+ vlib_log(VLIB_LOG_LEVEL_ERR, snat_main.log_class, __VA_ARGS__)
+#define nat_log_warn(...) \
+ vlib_log(VLIB_LOG_LEVEL_WARNING, snat_main.log_class, __VA_ARGS__)
+#define nat_log_notice(...) \
+ vlib_log(VLIB_LOG_LEVEL_NOTICE, snat_main.log_class, __VA_ARGS__)
+#define nat_log_info(...) \
+ vlib_log(VLIB_LOG_LEVEL_INFO, snat_main.log_class, __VA_ARGS__)
+#define nat_log_debug(...)\
+ vlib_log(VLIB_LOG_LEVEL_DEBUG, snat_main.log_class, __VA_ARGS__)