--- Net2/net/radix.h	2018/04/24 18:04:02	1.1
+++ Net2/net/radix.h	2018/04/24 18:21:50	1.1.1.2
@@ -30,9 +30,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)radix.h	7.4 (Berkeley) 6/28/90
+ *	from: @(#)radix.h	7.4 (Berkeley) 6/28/90
+ *	radix.h,v 1.3 1993/05/20 03:06:08 cgd Exp
  */
 
+#ifndef _NET_RADIX_H_
+#define _NET_RADIX_H_
+
 /*
  * Radix search tree node layout.
  */
@@ -116,3 +120,5 @@ extern struct radix_node_head {
 #define R_Malloc(p, t, n) (p = (t) malloc((unsigned long)(n), M_RTABLE, M_DONTWAIT))
 #define Free(p) free((caddr_t)p, M_RTABLE);
 #endif /*KERNEL*/
+
+#endif /* !_NET_RADIX_H_ */