freebsd-dev/sys/net/ethernet.h
1999-08-28 01:08:13 +00:00

98 lines
2.2 KiB
C

/*
* Fundamental constants relating to ethernet.
*
* $FreeBSD$
*
*/
#ifndef _NET_ETHERNET_H_
#define _NET_ETHERNET_H_
/*
* The number of bytes in an ethernet (MAC) address.
*/
#define ETHER_ADDR_LEN 6
/*
* The number of bytes in the type field.
*/
#define ETHER_TYPE_LEN 2
/*
* The number of bytes in the trailing CRC field.
*/
#define ETHER_CRC_LEN 4
/*
* The length of the combined header.
*/
#define ETHER_HDR_LEN (ETHER_ADDR_LEN*2+ETHER_TYPE_LEN)
/*
* The minimum packet length.
*/
#define ETHER_MIN_LEN 64
/*
* The maximum packet length.
*/
#define ETHER_MAX_LEN 1518
/*
* A macro to validate a length with
*/
#define ETHER_IS_VALID_LEN(foo) \
((foo) >= ETHER_MIN_LEN && (foo) <= ETHER_MAX_LEN)
/*
* Structure of a 10Mb/s Ethernet header.
*/
struct ether_header {
u_char ether_dhost[ETHER_ADDR_LEN];
u_char ether_shost[ETHER_ADDR_LEN];
u_short ether_type;
};
/*
* Structure of a 48-bit Ethernet address.
*/
struct ether_addr {
u_char octet[ETHER_ADDR_LEN];
};
#define ETHERTYPE_PUP 0x0200 /* PUP protocol */
#define ETHERTYPE_IP 0x0800 /* IP protocol */
#define ETHERTYPE_ARP 0x0806 /* Addr. resolution protocol */
#define ETHERTYPE_REVARP 0x8035 /* reverse Addr. resolution protocol */
#define ETHERTYPE_VLAN 0x8100 /* IEEE 802.1Q VLAN tagging */
#define ETHERTYPE_LOOPBACK 0x9000 /* used to test interfaces */
/* XXX - add more useful types here */
/*
* The ETHERTYPE_NTRAILER packet types starting at ETHERTYPE_TRAIL have
* (type-ETHERTYPE_TRAIL)*512 bytes of data followed
* by an ETHER type (as given above) and then the (variable-length) header.
*/
#define ETHERTYPE_TRAIL 0x1000 /* Trailer packet */
#define ETHERTYPE_NTRAILER 16
#define ETHERMTU (ETHER_MAX_LEN-ETHER_HDR_LEN-ETHER_CRC_LEN)
#define ETHERMIN (ETHER_MIN_LEN-ETHER_HDR_LEN-ETHER_CRC_LEN)
#ifndef KERNEL
#include <sys/cdefs.h>
/*
* Ethernet address conversion/parsing routines.
*/
__BEGIN_DECLS
struct ether_addr *ether_aton __P((char *));
int ether_hostton __P((char *, struct ether_addr *));
int ether_line __P((char *, struct ether_addr *, char *));
char *ether_ntoa __P((struct ether_addr *));
int ether_ntohost __P((char *, struct ether_addr *));
__END_DECLS
#endif /* !KERNEL */
#endif /* !_NET_ETHERNET_H_ */