+#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 */
+
+/* RFC 1201 */
+#define ARCTYPE_IP 212 /* IP protocol */
+#define ARCTYPE_ARP 213 /* address resolution protocol */
+#define ARCTYPE_REVARP 214 /* reverse addr resolution protocol */
+
+#define ARCTYPE_ATALK 221 /* Appletalk */
+#define ARCTYPE_BANIAN 247 /* Banyan Vines */
+#define ARCTYPE_IPX 250 /* Novell IPX */
+
+#define ARCTYPE_INET6 0xc4 /* IPng */
+#define ARCTYPE_DIAGNOSE 0x80 /* as per ANSI/ATA 878.1 */
+
+/*
+ * Structure of a 2.5MB/s Arcnet header on Linux. Linux has
+ * an extra "offset" field when given to interface code, and
+ * never presents packets that look like exception frames.
+ */
+struct arc_linux_header {
+ uint8_t arc_shost;
+ uint8_t arc_dhost;
+ uint16_t arc_offset;
+ uint8_t arc_type;
+ /*
+ * only present for newstyle encoding with LL fragmentation.
+ * Don't use sizeof(anything), use ARC_LINUX_HDR{,NEW}LEN
+ * instead.
+ */
+ uint8_t arc_flag;
+ uint16_t arc_seqid;
+};