if_ether.h

实现点到点的以太网协议,用于拨号上网,是拨号上网的基础部分软件模块.

/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Global definitions for the Ethernet IEEE 802.3 interface.
 *
 * Version:	@(#)if_ether.h	1.0.1a	02/08/94
 *
 * Author:	Fred N. van Kempen, <[e-mail]>
 *		Donald Becker, <[e-mail]>
 *		Alan Cox, <[e-mail]>
 *		Steve Whitehouse, <[e-mail]>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
 
#ifndef _LINUX_IF_ETHER_H
#define _LINUX_IF_ETHER_H

/*
 *	IEEE 802.3 Ethernet magic constants.  The frame sizes omit the preamble
 *	and FCS/CRC (frame check sequence). 
 */

#define ETH_ALEN	6		/* Octets in one ethernet addr	 */
#define ETH_HLEN	14		/* Total octets in header.	 */
#define ETH_ZLEN	60		/* Min. octets in frame sans FCS */
#define ETH_DATA_LEN	1500		/* Max. octets in payload	 */
#define ETH_FRAME_LEN	1514		/* Max. octets in frame sans FCS */

/*
 *	These are the defined Ethernet Protocol ID's.
 */

#define ETH_P_LOOP	0x0060		/* Ethernet Loopback packet	*/
#define ETH_P_PUP	0x0200		/* Xerox PUP packet		*/
#define ETH_P_PUPAT	0x0201		/* Xerox PUP Addr Trans packet	*/
#define ETH_P_IP	0x0800		/* Internet Protocol packet	*/
#define ETH_P_X25	0x0805		/* CCITT X.25			*/
#define ETH_P_ARP	0x0806		/* Address Resolution packet	*/
#define	ETH_P_BPQ	0x08FF		/* G8BPQ AX.25 Ethernet Packet	[ NOT AN OFFICIALLY REGISTERED ID ] */
#define ETH_P_IEEEPUP	0x0a00		/* Xerox IEEE802.3 PUP packet */
#define ETH_P_IEEEPUPAT	0x0a01		/* Xerox IEEE802.3 PUP Addr Trans packet */
#define ETH_P_DEC       0x6000          /* DEC Assigned proto           */
#define ETH_P_DNA_DL    0x6001          /* DEC DNA Dump/Load            */
#define ETH_P_DNA_RC    0x6002          /* DEC DNA Remote Console       */
#define ETH_P_DNA_RT    0x6003          /* DEC DNA Routing              */
#define ETH_P_LAT       0x6004          /* DEC LAT                      */
#define ETH_P_DIAG      0x6005          /* DEC Diagnostics              */
#define ETH_P_CUST      0x6006          /* DEC Customer use             */
#define ETH_P_SCA       0x6007          /* DEC Systems Comms Arch       */
#define ETH_P_RARP      0x8035		/* Reverse Addr Res packet	*/
#define ETH_P_ATALK	0x809B		/* Appletalk DDP		*/
#define ETH_P_AARP	0x80F3		/* Appletalk AARP		*/
#define ETH_P_IPX	0x8137		/* IPX over DIX			*/
#define ETH_P_IPV6	0x86DD		/* IPv6 over bluebook		*/
#define ETH_P_PPP_DISC	0x8863		/* PPPoE discovery messages     */
#define ETH_P_PPP_SES	0x8864		/* PPPoE session messages	*/
#define ETH_P_ATMMPOA	0x884c		/* MultiProtocol Over ATM	*/
#define ETH_P_ATMFATE	0x8884		/* Frame-based ATM Transport
					 * over Ethernet
					 */

/*
 *	Non DIX types. Won't clash for 1500 types.
 */
 
#define ETH_P_802_3	0x0001		/* Dummy type for 802.3 frames  */
#define ETH_P_AX25	0x0002		/* Dummy protocol id for AX.25  */
#define ETH_P_ALL	0x0003		/* Every packet (be careful!!!) */
#define ETH_P_802_2	0x0004		/* 802.2 frames 		*/
#define ETH_P_SNAP	0x0005		/* Internal only		*/
#define ETH_P_DDCMP     0x0006          /* DEC DDCMP: Internal only     */
#define ETH_P_WAN_PPP   0x0007          /* Dummy type for WAN PPP frames*/
#define ETH_P_PPP_MP    0x0008          /* Dummy type for PPP MP frames */
#define ETH_P_LOCALTALK 0x0009		/* Localtalk pseudo type 	*/
#define ETH_P_PPPTALK	0x0010		/* Dummy type for Atalk over PPP*/
#define ETH_P_TR_802_2	0x0011		/* 802.2 frames 		*/
#define ETH_P_MOBITEX	0x0015		/* Mobitex ([e-mail])	*/
#define ETH_P_CONTROL	0x0016		/* Card specific control frames */
#define ETH_P_IRDA	0x0017		/* Linux-IrDA			*/
#define ETH_P_ECONET	0x0018		/* Acorn Econet			*/

/*
 *	This is an Ethernet frame header.
 */
 
struct ethhdr 
{
	unsigned char	h_dest[ETH_ALEN];	/* destination eth addr	*/
	unsigned char	h_source[ETH_ALEN];	/* source ether addr	*/
	unsigned short	h_proto;		/* packet type ID field	*/
};

#endif	/* _LINUX_IF_ETHER_H */