$OpenBSD$

Index: protocol_parser.c
--- protocol_parser.c.orig
+++ protocol_parser.c
@@ -21,6 +21,7 @@
 #include <string.h>
 #include <sys/socket.h>
 #include <net/if_arp.h>
+#include <netinet/in.h>
 #include <netinet/ip.h>
 #define __FAVOR_BSD
 #include <netinet/udp.h>
