1 /* Copyright (C) 1997-2022 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.  */
33 struct ether_addr
34 {
35   uint8_t ether_addr_octet[ETH_ALEN];
36 } __attribute__ ((__packed__));
37 
38 /* 10Mb/s ethernet header */
39 struct 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 */
84