/* * Fundamental constants relating to ethernet. * * $\Id: ethernet.h,v 1.2 1996/08/06 21:14:21 phk Exp $ * */#ifndef _NET_ETHERNET_H_#define _NET_ETHERNET_H_/* * The number of bytes in an ethernet (MAC) address. */#define	ETHER_ADDR_LEN		6/* * The number of bytes in the type field. */#define	ETHER_TYPE_LEN		2/* * The number of bytes in the trailing CRC field. */#define	ETHER_CRC_LEN		4/* * The length of the combined header. */#define	ETHER_HDR_LEN		(ETHER_ADDR_LEN*2+ETHER_TYPE_LEN)/* * The minimum packet length. */#define	ETHER_MIN_LEN		64/* * The maximum packet length. */#define	ETHER_MAX_LEN		1518/* * A macro to validate a length with */#define	ETHER_IS_VALID_LEN(foo)	\	((foo) >= ETHER_MIN_LEN && (foo) <= ETHER_MAX_LEN)/* * Structure of a 10Mb/s Ethernet header. */struct	ether_header {	u_char	ether_dhost[ETHER_ADDR_LEN];	u_char	ether_shost[ETHER_ADDR_LEN];	u_short	ether_type;};/* * Structure of a 48-bit Ethernet address. */struct	ether_addr {	u_char octet[ETHER_ADDR_LEN];};#endif