if_dl.h revision 96184 
1/*
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)if_dl.h	8.1 (Berkeley) 6/10/93
34 * $FreeBSD: head/sys/net/if_dl.h 96184 2002-05-07 22:14:06Z kbyanc $
35 */
36
37#ifndef _NET_IF_DL_H_
38#define _NET_IF_DL_H_
39
40/*
41 * A Link-Level Sockaddr may specify the interface in one of two
42 * ways: either by means of a system-provided index number (computed
43 * anew and possibly differently on every reboot), or by a human-readable
44 * string such as "il0" (for managerial convenience).
45 *
46 * Census taking actions, such as something akin to SIOCGCONF would return
47 * both the index and the human name.
48 *
49 * High volume transactions (such as giving a link-level ``from'' address
50 * in a recvfrom or recvmsg call) may be likely only to provide the indexed
51 * form, (which requires fewer copy operations and less space).
52 *
53 * The form and interpretation  of the link-level address is purely a matter
54 * of convention between the device driver and its consumers; however, it is
55 * expected that all drivers for an interface of a given if_type will agree.
56 */
57
58/*
59 * Structure of a Link-Level sockaddr:
60 */
61struct sockaddr_dl {
62	u_char	sdl_len;	/* Total length of sockaddr */
63	u_char	sdl_family;	/* AF_LINK */
64	u_short	sdl_index;	/* if != 0, system given index for interface */
65	u_char	sdl_type;	/* interface type */
66	u_char	sdl_nlen;	/* interface name length, no trailing 0 reqd. */
67	u_char	sdl_alen;	/* link level address length */
68	u_char	sdl_slen;	/* link layer selector length */
69	char	sdl_data[46];	/* minimum work area, can be larger;
70				   contains both if name and ll address */
71};
72
73#define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
74
75#ifndef _KERNEL
76
77#include <sys/cdefs.h>
78
79__BEGIN_DECLS
80void	link_addr(const char *, struct sockaddr_dl *);
81char	*link_ntoa(const struct sockaddr_dl *);
82__END_DECLS
83
84#endif /* !_KERNEL */
85
86#endif
87