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/cdefs.h> 25 #include <sys/types.h> 26 #include <stdint.h> 27 #include <net/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 }; 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 }; 45 46 /* Ethernet protocol ID's */ 47 #define ETHERTYPE_PUP 0x0200 /* Xerox PUP */ 48 #define ETHERTYPE_IP 0x0800 /* IP */ 49 #define ETHERTYPE_ARP 0x0806 /* Address resolution */ 50 #define ETHERTYPE_REVARP 0x8035 /* Reverse ARP */ 51 52 #define ETHER_ADDR_LEN ETH_ALEN /* size of ethernet addr */ 53 #define ETHER_TYPE_LEN 2 /* bytes in type field */ 54 #define ETHER_CRC_LEN 4 /* bytes in CRC field */ 55 #define ETHER_HDR_LEN ETH_HLEN /* total octets in header */ 56 #define ETHER_MIN_LEN (ETH_ZLEN + ETH_CRC_LEN) /* min packet length */ 57 #define ETHER_MAX_LEN (ETH_FRAME_LEN + ETH_CRC_LEN) /* max packet length */ 58 59 /* make sure ethernet length is valid */ 60 #define ETHER_IS_VALID_LEN(foo) \ 61 ((foo) >= ETHER_MIN_LEN && (foo) <= ETHER_MAX_LEN) 62 63 /* 64 * The ETHERTYPE_NTRAILER packet types starting at ETHERTYPE_TRAIL have 65 * (type-ETHERTYPE_TRAIL)*512 bytes of data followed 66 * by an ETHER type (as given above) and then the (variable-length) header. 67 */ 68 #define ETHERTYPE_TRAIL 0x1000 /* Trailer packet */ 69 #define ETHERTYPE_NTRAILER 16 70 71 #define ETHERMTU ETH_DATA_LEN 72 #define ETHERMIN (ETHER_MIN_LEN-ETHER_HDR_LEN-ETHER_CRC_LEN) 73 74 __END_DECLS 75 76 #endif /* net/ethernet.h */ 77