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if_dl.h revision 1.4 
      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  *	from: @(#)if_dl.h	8.1 (Berkeley) 6/10/93
     34  *	$Id: if_dl.h,v 1.4 1994/05/13 06:02:33 mycroft Exp $
     35  */
     36 
     37 /*
     38  * A Link-Level Sockaddr may specify the interface in one of two
     39  * ways: either by means of a system-provided index number (computed
     40  * anew and possibly differently on every reboot), or by a human-readable
     41  * string such as "il0" (for managerial convenience).
     42  *
     43  * Census taking actions, such as something akin to SIOCGCONF would return
     44  * both the index and the human name.
     45  *
     46  * High volume transactions (such as giving a link-level ``from'' address
     47  * in a recvfrom or recvmsg call) may be likely only to provide the indexed
     48  * form, (which requires fewer copy operations and less space).
     49  *
     50  * The form and interpretation  of the link-level address is purely a matter
     51  * of convention between the device driver and its consumers; however, it is
     52  * expected that all drivers for an interface of a given if_type will agree.
     53  */
     54 
     55 /*
     56  * Structure of a Link-Level sockaddr:
     57  */
     58 struct sockaddr_dl {
     59 	u_char	sdl_len;	/* Total length of sockaddr */
     60 	u_char	sdl_family;	/* AF_DLI */
     61 	u_short	sdl_index;	/* if != 0, system given index for interface */
     62 	u_char	sdl_type;	/* interface type */
     63 	u_char	sdl_nlen;	/* interface name length, no trailing 0 reqd. */
     64 	u_char	sdl_alen;	/* link level address length */
     65 	u_char	sdl_slen;	/* link layer selector length */
     66 	char	sdl_data[12];	/* minimum work area, can be larger;
     67 				   contains both if name and ll address */
     68 };
     69 
     70 #define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
     71 
     72 #ifndef KERNEL
     73 
     74 #include <sys/cdefs.h>
     75 
     76 __BEGIN_DECLS
     77 void	link_addr __P((const char *, struct sockaddr_dl *));
     78 char	*link_ntoa __P((const struct sockaddr_dl *));
     79 __END_DECLS
     80 
     81 #endif /* !KERNEL */
     82