1/* Copyright (C) 1997-2025 Free Software Foundation, Inc.
 2   This file is part of the GNU C Library.
 3
 4   The GNU C Library is free software; you can redistribute it and/or
 5   modify it under the terms of the GNU Lesser General Public
 6   License as published by the Free Software Foundation; either
 7   version 2.1 of the License, or (at your option) any later version.
 8
 9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library; if not, see
16   <https://www.gnu.org/licenses/>.  */
17
18/* Based on the FreeBSD version of this file. Curiously, that file
19   lacks a copyright in the header. */
20
21#ifndef __NET_ETHERNET_H
22#define __NET_ETHERNET_H 1
23
24#include <sys/types.h>
25#include <stdint.h>
26
27#include <linux/if_ether.h>     /* IEEE 802.3 Ethernet constants */
28
29__BEGIN_DECLS
30
31/* This is a name for the 48 bit ethernet address available on many
32   systems.  */
33struct ether_addr
34{
35  uint8_t ether_addr_octet[ETH_ALEN];
36} __attribute__ ((__packed__));
37
38/* 10Mb/s ethernet header */
39struct ether_header
40{
41  uint8_t  ether_dhost[ETH_ALEN];	/* destination eth addr	*/
42  uint8_t  ether_shost[ETH_ALEN];	/* source ether addr	*/
43  uint16_t ether_type;		        /* packet type ID field	*/
44} __attribute__ ((__packed__));
45
46/* Ethernet protocol ID's */
47#define	ETHERTYPE_PUP		0x0200          /* Xerox PUP */
48#define ETHERTYPE_SPRITE	0x0500		/* Sprite */
49#define	ETHERTYPE_IP		0x0800		/* IP */
50#define	ETHERTYPE_ARP		0x0806		/* Address resolution */
51#define	ETHERTYPE_REVARP	0x8035		/* Reverse ARP */
52#define ETHERTYPE_AT		0x809B		/* AppleTalk protocol */
53#define ETHERTYPE_AARP		0x80F3		/* AppleTalk ARP */
54#define	ETHERTYPE_VLAN		0x8100		/* IEEE 802.1Q VLAN tagging */
55#define ETHERTYPE_IPX		0x8137		/* IPX */
56#define	ETHERTYPE_IPV6		0x86dd		/* IP protocol version 6 */
57#define ETHERTYPE_LOOPBACK	0x9000		/* used to test interfaces */
58
59#define	ETHER_ADDR_LEN	ETH_ALEN                 /* size of ethernet addr */
60#define	ETHER_TYPE_LEN	2                        /* bytes in type field */
61#define	ETHER_CRC_LEN	4                        /* bytes in CRC field */
62#define	ETHER_HDR_LEN	ETH_HLEN                 /* total octets in header */
63#define	ETHER_MIN_LEN	(ETH_ZLEN + ETHER_CRC_LEN) /* min packet length */
64#define	ETHER_MAX_LEN	(ETH_FRAME_LEN + ETHER_CRC_LEN) /* max packet length */
65
66/* make sure ethernet length is valid */
67#define	ETHER_IS_VALID_LEN(foo)	\
68	((foo) >= ETHER_MIN_LEN && (foo) <= ETHER_MAX_LEN)
69
70/*
71 * The ETHERTYPE_NTRAILER packet types starting at ETHERTYPE_TRAIL have
72 * (type-ETHERTYPE_TRAIL)*512 bytes of data followed
73 * by an ETHER type (as given above) and then the (variable-length) header.
74 */
75#define	ETHERTYPE_TRAIL		0x1000		/* Trailer packet */
76#define	ETHERTYPE_NTRAILER	16
77
78#define	ETHERMTU	ETH_DATA_LEN
79#define	ETHERMIN	(ETHER_MIN_LEN - ETHER_HDR_LEN - ETHER_CRC_LEN)
80
81__END_DECLS
82
83#endif	/* net/ethernet.h */