+#include <netdissect-stdinc.h>
+
+#include "netdissect.h"
+#include "extract.h"
+
+/*
+ * from: NetBSD: if_arc.h,v 1.13 1999/11/19 20:41:19 thorpej Exp
+ */
+
+/*
+ * Structure of a 2.5MB/s Arcnet header on the BSDs,
+ * as given to interface code.
+ */
+struct arc_header {
+ uint8_t arc_shost;
+ uint8_t arc_dhost;
+ uint8_t arc_type;
+ /*
+ * only present for newstyle encoding with LL fragmentation.
+ * Don't use sizeof(anything), use ARC_HDR{,NEW}LEN instead.
+ */
+ uint8_t arc_flag;
+ uint16_t arc_seqid;
+
+ /*
+ * only present in exception packets (arc_flag == 0xff)
+ */
+ uint8_t arc_type2; /* same as arc_type */
+ uint8_t arc_flag2; /* real flag value */
+ uint16_t arc_seqid2; /* real seqid value */
+};
+
+#define ARC_HDRLEN 3
+#define ARC_HDRNEWLEN 6
+#define ARC_HDRNEWLEN_EXC 10
+
+/* RFC 1051 */
+#define ARCTYPE_IP_OLD 240 /* IP protocol */
+#define ARCTYPE_ARP_OLD 241 /* address resolution protocol */