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

   1 /* Copyright (C) 1997-2023 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 */