xref: /freebsd/sys/net/if_dl.h (revision 6e8394b8baa7d5d9153ab90de6824bcd19b3b4e1)
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  * $Id: if_dl.h,v 1.6 1997/02/22 09:41:00 peter Exp $
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  */
61 struct sockaddr_dl {
62 	u_char	sdl_len;	/* Total length of sockaddr */
63 	u_char	sdl_family;	/* AF_DLI */
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[12];	/* minimum work area, can be larger;
70 				   contains both if name and ll address */
71 	u_short	sdl_rcf;	/* source routing control */
72 	u_short	sdl_route[16];	/* source routing information */
73 };
74 
75 #define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
76 
77 #ifndef KERNEL
78 
79 #include <sys/cdefs.h>
80 
81 __BEGIN_DECLS
82 void	link_addr __P((const char *, struct sockaddr_dl *));
83 char	*link_ntoa __P((const struct sockaddr_dl *));
84 __END_DECLS
85 
86 #endif /* !KERNEL */
87 
88 #endif
89