1/* $OpenBSD: if_dl.h,v 1.13 2023/11/12 17:51:40 bluhm Exp $ */
2/* $NetBSD: if_dl.h,v 1.8 1995/03/26 20:30:13 jtc Exp $ */
3
4/*
5 * Copyright (c) 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)if_dl.h 8.1 (Berkeley) 6/10/93
33 */
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#ifndef _NET_IF_DL_H_
54#define _NET_IF_DL_H_
55
56/*
57 * Structure of a Link-Level sockaddr:
58 */
59struct sockaddr_dl {
60 u_char sdl_len; /* Total length of sockaddr */
61 u_char sdl_family; /* AF_LINK */
62 u_int16_t sdl_index; /* if != 0, system given index for interface */
63 u_char sdl_type; /* interface type */
64 u_char sdl_nlen; /* interface name length, no trailing 0 reqd. */
65 u_char sdl_alen; /* link level address length */
66 u_char sdl_slen; /* link layer selector length, mostly 0 */
67 char sdl_data[24]; /* minimum work area, can be larger;
68 contains both if name and ll address;
69 big enough for IFNAMSIZ plus 8byte ll addr */
70};
71
72#define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
73
74#ifdef _KERNEL
75
76static inline struct sockaddr_dl *
77satosdl(struct sockaddr *sa)
78{
79 return ((struct sockaddr_dl *)(sa));
80}
81
82static inline const struct sockaddr_dl *
83satosdl_const(const struct sockaddr *sa)
84{
85 return ((const struct sockaddr_dl *)(sa));
86}
87
88static inline struct sockaddr *
89sdltosa(struct sockaddr_dl *sdl)
90{
91 return ((struct sockaddr *)(sdl));
92}
93
94#else /* _KERNEL */
95
96__BEGIN_DECLS
97char *link_ntoa(const struct sockaddr_dl *);
98__END_DECLS
99
100#endif /* _KERNEL */
101#endif /* _NET_IF_DL_H_ */