ethernet.h revision 34649
1/* 2 * Fundamental constants relating to ethernet. 3 * 4 * $Id: ethernet.h,v 1.8 1997/02/22 09:40:58 peter Exp $ 5 * 6 */ 7 8#ifndef _NET_ETHERNET_H_ 9#define _NET_ETHERNET_H_ 10 11/* 12 * The number of bytes in an ethernet (MAC) address. 13 */ 14#define ETHER_ADDR_LEN 6 15 16/* 17 * The number of bytes in the type field. 18 */ 19#define ETHER_TYPE_LEN 2 20 21/* 22 * The number of bytes in the trailing CRC field. 23 */ 24#define ETHER_CRC_LEN 4 25 26/* 27 * The length of the combined header. 28 */ 29#define ETHER_HDR_LEN (ETHER_ADDR_LEN*2+ETHER_TYPE_LEN) 30 31/* 32 * The minimum packet length. 33 */ 34#define ETHER_MIN_LEN 64 35 36/* 37 * The maximum packet length. 38 */ 39#define ETHER_MAX_LEN 1518 40 41/* 42 * A macro to validate a length with 43 */ 44#define ETHER_IS_VALID_LEN(foo) \ 45 ((foo) >= ETHER_MIN_LEN && (foo) <= ETHER_MAX_LEN) 46 47/* 48 * Structure of a 10Mb/s Ethernet header. 49 */ 50struct ether_header { 51 u_char ether_dhost[ETHER_ADDR_LEN]; 52 u_char ether_shost[ETHER_ADDR_LEN]; 53 u_short ether_type; 54}; 55 56/* 57 * Structure of a 48-bit Ethernet address. 58 */ 59struct ether_addr { 60 u_char octet[ETHER_ADDR_LEN]; 61}; 62 63#define ETHERTYPE_PUP 0x0200 /* PUP protocol */ 64#define ETHERTYPE_IP 0x0800 /* IP protocol */ 65#define ETHERTYPE_ARP 0x0806 /* Addr. resolution protocol */ 66#define ETHERTYPE_REVARP 0x8035 /* reverse Addr. resolution protocol */ 67#define ETHERTYPE_VLAN 0x8100 /* IEEE 802.1Q VLAN tagging */ 68#define ETHERTYPE_LOOPBACK 0x9000 /* used to test interfaces */ 69/* XXX - add more useful types here */ 70 71/* 72 * The ETHERTYPE_NTRAILER packet types starting at ETHERTYPE_TRAIL have 73 * (type-ETHERTYPE_TRAIL)*512 bytes of data followed 74 * by an ETHER type (as given above) and then the (variable-length) header. 75 */ 76#define ETHERTYPE_TRAIL 0x1000 /* Trailer packet */ 77#define ETHERTYPE_NTRAILER 16 78 79#define ETHERMTU (ETHER_MAX_LEN-ETHER_HDR_LEN-ETHER_CRC_LEN) 80#define ETHERMIN (ETHER_MIN_LEN-ETHER_HDR_LEN-ETHER_CRC_LEN) 81 82#ifndef KERNEL 83#include <sys/cdefs.h> 84 85/* 86 * Ethernet address conversion/parsing routines. 87 */ 88__BEGIN_DECLS 89struct ether_addr *ether_aton __P((char *)); 90int ether_hostton __P((char *, struct ether_addr *)); 91int ether_line __P((char *, struct ether_addr *, char *)); 92char *ether_ntoa __P((struct ether_addr *)); 93int ether_ntohost __P((char *, struct ether_addr *)); 94__END_DECLS 95#endif /* !KERNEL */ 96 97#endif /* !_NET_ETHERNET_H_ */ 98