Index: net_utilities.c
--- net_utilities.c.orig
+++ net_utilities.c
@@ -24,6 +24,8 @@
 /* necessary header files and defines */
 
 #include <stdio.h>
+#include <stdlib.h> /* exit */
+#include <string.h> /* memcpy */
 
 #include "net_utilities.h"
 #include "general_utilities.h"
