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if_dl.h revision 1.13 
      1 /*	$NetBSD: if_dl.h,v 1.13 2004/11/20 00:53:13 wiz Exp $	*/
      2 
      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  *	@(#)if_dl.h	8.1 (Berkeley) 6/10/93
     32  */
     33 
     34 /*
     35  * A Link-Level Sockaddr may specify the interface in one of two
     36  * ways: either by means of a system-provided index number (computed
     37  * anew and possibly differently on every reboot), or by a human-readable
     38  * string such as "il0" (for managerial convenience).
     39  *
     40  * Census taking actions, such as something akin to SIOCGCONF would return
     41  * both the index and the human name.
     42  *
     43  * High volume transactions (such as giving a link-level ``from'' address
     44  * in a recvfrom or recvmsg call) may be likely only to provide the indexed
     45  * form, (which requires fewer copy operations and less space).
     46  *
     47  * The form and interpretation  of the link-level address is purely a matter
     48  * of convention between the device driver and its consumers; however, it is
     49  * expected that all drivers for an interface of a given if_type will agree.
     50  */
     51 
     52 #ifndef _NET_IF_DL_H_
     53 #define _NET_IF_DL_H_
     54 
     55 #include <sys/ansi.h>
     56 
     57 #ifndef sa_family_t
     58 typedef __sa_family_t	sa_family_t;
     59 #define sa_family_t	__sa_family_t
     60 #endif
     61 
     62 /*
     63  * Structure of a Link-Level sockaddr:
     64  */
     65 struct sockaddr_dl {
     66 	u_char	    sdl_len;	/* Total length of sockaddr */
     67 	sa_family_t sdl_family;	/* AF_LINK */
     68 	u_int16_t   sdl_index;	/* if != 0, system given index for interface */
     69 	u_char	    sdl_type;	/* interface type */
     70 	u_char	    sdl_nlen;	/* interface name length, no trailing 0 reqd. */
     71 	u_char	    sdl_alen;	/* link level address length */
     72 	u_char	    sdl_slen;	/* link layer selector length */
     73 	char	    sdl_data[12]; /* minimum work area, can be larger;
     74 				     contains both if name and ll address */
     75 };
     76 
     77 #define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
     78 
     79 #ifndef _KERNEL
     80 
     81 #include <sys/cdefs.h>
     82 
     83 __BEGIN_DECLS
     84 void	link_addr __P((const char *, struct sockaddr_dl *));
     85 char	*link_ntoa __P((const struct sockaddr_dl *));
     86 __END_DECLS
     87 
     88 #endif /* !_KERNEL */
     89 
     90 #endif /* _NET_IF_DL_H_ */
     91