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/*
* Fundamental constants relating to ethernet.
*
* $Id$
*
*/
#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
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