freebsd-nq/sys/net/ethernet.h
Poul-Henning Kamp 26a8b0bf7e Megacommit to straigthen out ETHER_ mess.
I'm pretty convinced after looking at this that the majority of our
drivers are confused about the in/exclusion of ETHER_CRC_LEN :-(
1996-08-06 21:14:36 +00:00

64 lines
1.0 KiB
C

/*
* Fundamental constants relating to ethernet.
*
* $Id: ethernet.h,v 1.1 1996/08/05 14:02:38 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