1/* Copyright (C) 1997-2026 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 */