glibc/sysdeps/unix/sysv/linux/net/ethernet.h

/* Copyright (C) 1997, 1999, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

/* Based on the FreeBSD version of this file. Curiously, that file
   lacks a copyright in the header. */

#ifndef __NET_ETHERNET_H
#define __NET_ETHERNET_H 1

#include <sys/cdefs.h>
#include <sys/types.h>
#include <linux/if_ether.h>     /* IEEE 802.3 Ethernet constants */

__BEGIN_DECLS

/* This is a name for the 48 bit ethernet address available on many
   systems.  */
struct ether_addr
{
  u_int8_t ether_addr_octet[ETH_ALEN];
} __attribute__ ((__packed__));

/* 10Mb/s ethernet header */
struct ether_header
{
  u_int8_t  ether_dhost[ETH_ALEN];	/* destination eth addr	*/
  u_int8_t  ether_shost[ETH_ALEN];	/* source ether addr	*/
  u_int16_t ether_type;		        /* packet type ID field	*/
} __attribute__ ((__packed__));

/* Ethernet protocol ID's */
#define	ETHERTYPE_PUP		0x0200          /* Xerox PUP */
#define	ETHERTYPE_IP		0x0800		/* IP */
#define	ETHERTYPE_ARP		0x0806		/* Address resolution */
#define	ETHERTYPE_REVARP	0x8035		/* Reverse ARP */

#define	ETHER_ADDR_LEN	ETH_ALEN                 /* size of ethernet addr */
#define	ETHER_TYPE_LEN	2                        /* bytes in type field */
#define	ETHER_CRC_LEN	4                        /* bytes in CRC field */
#define	ETHER_HDR_LEN	ETH_HLEN                 /* total octets in header */
#define	ETHER_MIN_LEN	(ETH_ZLEN + ETHER_CRC_LEN) /* min packet length */
#define	ETHER_MAX_LEN	(ETH_FRAME_LEN + ETHER_CRC_LEN) /* max packet length */

/* make sure ethenet length is valid */
#define	ETHER_IS_VALID_LEN(foo)	\
	((foo) >= ETHER_MIN_LEN && (foo) <= ETHER_MAX_LEN)

/*
 * The ETHERTYPE_NTRAILER packet types starting at ETHERTYPE_TRAIL have
 * (type-ETHERTYPE_TRAIL)*512 bytes of data followed
 * by an ETHER type (as given above) and then the (variable-length) header.
 */
#define	ETHERTYPE_TRAIL		0x1000		/* Trailer packet */
#define	ETHERTYPE_NTRAILER	16

#define	ETHERMTU	ETH_DATA_LEN
#define	ETHERMIN	(ETHER_MIN_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)

__END_DECLS

#endif	/* net/ethernet.h */