--- Net2/net/netisr.h	2018/04/24 18:04:02	1.1.1.1
+++ Net2/net/netisr.h	2018/04/24 18:21:42	1.1.1.2
@@ -30,9 +30,13 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	@(#)netisr.h	7.8 (Berkeley) 5/7/91
+ *	from: @(#)netisr.h	7.8 (Berkeley) 5/7/91
+ *	netisr.h,v 1.3 1993/05/20 03:06:05 cgd Exp
  */
 
+#ifndef _NET_NETISR_H_
+#define _NET_NETISR_H_
+
 /*
  * The networking code runs off software interrupts.
  *
@@ -84,3 +88,5 @@ int	softem;
 int	netisr;				/* scheduling bits for network */
 #endif
 #endif
+
+#endif /* !_NET_NETISR_H_ */