1/*
2 * Fundamental constants relating to ethernet.
3 *
| 1/*
2 * Fundamental constants relating to ethernet.
3 *
|
4 * $Id$
| 4 * $Id: ethernet.h,v 1.1 1996/08/05 14:02:38 phk Exp $
|
5 *
6 */
7
| 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 */
|
8#define ETHER_ADDR_LEN 6
| 14#define ETHER_ADDR_LEN 6
|
9#define ETHER_TYPE_LEN 2
10#define ETHER_CRC_LENGTH 4
11#define ETHER_HDR_SIZE (ETHER_ADDR_LEN*2+ETHER_TYPE_LEN)
12#define ETHER_MIN_LEN 64
13#define ETHER_MAX_LEN 1518
| 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#endif
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