1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#ifndef _NET_IF_DL_H_
33#define _NET_IF_DL_H_
34
35/*
36 * A Link-Level Sockaddr may specify the interface in one of two
37 * ways: either by means of a system-provided index number (computed
38 * anew and possibly differently on every reboot), or by a human-readable
39 * string such as "il0" (for managerial convenience).
40 *
41 * Census taking actions, such as something akin to SIOCGCONF would return
42 * both the index and the human name.
43 *
44 * High volume transactions (such as giving a link-level ``from'' address
45 * in a recvfrom or recvmsg call) may be likely only to provide the indexed
46 * form, (which requires fewer copy operations and less space).
47 *
48 * The form and interpretation  of the link-level address is purely a matter
49 * of convention between the device driver and its consumers; however, it is
50 * expected that all drivers for an interface of a given if_type will agree.
51 */
52
53/*
54 * Structure of a Link-Level sockaddr:
55 */
56struct sockaddr_dl {
57	u_char	sdl_len;	/* Total length of sockaddr */
58	u_char	sdl_family;	/* AF_LINK */
59	u_short	sdl_index;	/* if != 0, system given index for interface */
60	u_char	sdl_type;	/* interface type */
61	u_char	sdl_nlen;	/* interface name length, no trailing 0 reqd. */
62	u_char	sdl_alen;	/* link level address length */
63	u_char	sdl_slen;	/* link layer selector length */
64	char	sdl_data[46];	/* minimum work area, can be larger;
65				   contains both if name and ll address */
66};
67
68#define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
69#define CLLADDR(s) ((c_caddr_t)((s)->sdl_data + (s)->sdl_nlen))
70#define LLINDEX(s) ((s)->sdl_index)
71
72struct ifnet;
73struct sockaddr_dl *link_alloc_sdl(size_t, int);
74void link_free_sdl(struct sockaddr *sa);
75struct sockaddr_dl *link_init_sdl(struct ifnet *, struct sockaddr *, u_char);
76
77#ifndef _KERNEL
78
79#include <sys/cdefs.h>
80
81__BEGIN_DECLS
82void	link_addr(const char *, struct sockaddr_dl *);
83char	*link_ntoa(const struct sockaddr_dl *);
84__END_DECLS
85
86#endif /* !_KERNEL */
87
88#endif
89