+#define rt_rt rt_rtu.rtu_rt /* pass to ioctl */
+#define rt_hash rt_rtu.rtu_entry.rtu_hash /* for net or host */
+#define rt_dst rt_rtu.rtu_entry.rtu_dst /* match value */
+#define rt_gateway rt_rtu.rtu_entry.rtu_gateway /* who to forward to */
+#define rt_flags rt_rtu.rtu_entry.rtu_flags /* see below */
+#define rt_retry rt_rtu.rtu_entry.rtu_retry /* retries of ioctl */
+#define rt_timer rt_rtu.rtu_entry.rtu_timer /* for invalidation */
+#define rt_metric rt_rtu.rtu_entry.rtu_metric /* cost of route */
+#define rt_ifp rt_rtu.rtu_entry.rtu_ifp /* interface to take */
+