sys/net/if_dl.h

   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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      @(#)if_dl.h     8.1 (Berkeley) 6/10/93
  30  * $FreeBSD$
  31  */
  32
  33 #ifndef _NET_IF_DL_H_
  34 #define _NET_IF_DL_H_
  35
  36 /*
  37  * A Link-Level Sockaddr may specify the interface in one of two
  38  * ways: either by means of a system-provided index number (computed
  39  * anew and possibly differently on every reboot), or by a human-readable
  40  * string such as "il0" (for managerial convenience).
  41  *
  42  * Census taking actions, such as something akin to SIOCGCONF would return
  43  * both the index and the human name.
  44  *
  45  * High volume transactions (such as giving a link-level ``from'' address
  46  * in a recvfrom or recvmsg call) may be likely only to provide the indexed
  47  * form, (which requires fewer copy operations and less space).
  48  *
  49  * The form and interpretation  of the link-level address is purely a matter
  50  * of convention between the device driver and its consumers; however, it is
  51  * expected that all drivers for an interface of a given if_type will agree.
  52  */
  53
  54 /*
  55  * Structure of a Link-Level sockaddr:
  56  */
  57 struct sockaddr_dl {
  58         u_char  sdl_len;        /* Total length of sockaddr */
  59         u_char  sdl_family;     /* AF_LINK */
  60         u_short sdl_index;      /* if != 0, system given index for interface */
  61         u_char  sdl_type;       /* interface type */
  62         u_char  sdl_nlen;       /* interface name length, no trailing 0 reqd. */
  63         u_char  sdl_alen;       /* link level address length */
  64         u_char  sdl_slen;       /* link layer selector length */
  65         char    sdl_data[46];   /* minimum work area, can be larger;
  66                                    contains both if name and ll address */
  67 };
  68
  69 #define LLADDR(s) ((caddr_t)((s)->sdl_data + (s)->sdl_nlen))
  70 #define CLLADDR(s) ((c_caddr_t)((s)->sdl_data + (s)->sdl_nlen))
  71 #define LLINDEX(s) ((s)->sdl_index)
  72
  73
  74 struct ifnet;
  75 struct sockaddr_dl *link_alloc_sdl(size_t, int);
  76 void link_free_sdl(struct sockaddr *sa);
  77 struct sockaddr_dl *link_init_sdl(struct ifnet *, struct sockaddr *, u_char);
  78
  79 #ifndef _KERNEL
  80
  81 #include <sys/cdefs.h>
  82
  83 __BEGIN_DECLS
  84 void    link_addr(const char *, struct sockaddr_dl *);
  85 char    *link_ntoa(const struct sockaddr_dl *);
  86 __END_DECLS
  87
  88 #endif /* !_KERNEL */
  89
  90 #endif