dist/tcpdump/sll.h

   1 /*      $NetBSD$        */
   2
   3 /*-
   4  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from the Stanford/CMU enet packet filter,
   8  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
   9  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
  10  * Berkeley Laboratory.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  *
  36  * @(#) Header: /tcpdump/master/tcpdump/sll.h,v 1.7 2002/12/11 07:14:11 guy Exp (LBL)
  37  */
  38
  39 /*
  40  * For captures on Linux cooked sockets, we construct a fake header
  41  * that includes:
  42  *
  43  *      a 2-byte "packet type" which is one of:
  44  *
  45  *              LINUX_SLL_HOST          packet was sent to us
  46  *              LINUX_SLL_BROADCAST     packet was broadcast
  47  *              LINUX_SLL_MULTICAST     packet was multicast
  48  *              LINUX_SLL_OTHERHOST     packet was sent to somebody else
  49  *              LINUX_SLL_OUTGOING      packet was sent *by* us;
  50  *
  51  *      a 2-byte Ethernet protocol field;
  52  *
  53  *      a 2-byte link-layer type;
  54  *
  55  *      a 2-byte link-layer address length;
  56  *
  57  *      an 8-byte source link-layer address, whose actual length is
  58  *      specified by the previous value.
  59  *
  60  * All fields except for the link-layer address are in network byte order.
  61  *
  62  * DO NOT change the layout of this structure, or change any of the
  63  * LINUX_SLL_ values below.  If you must change the link-layer header
  64  * for a "cooked" Linux capture, introduce a new DLT_ type (ask
  65  * "tcpdump-workers@tcpdump.org" for one, so that you don't give it a
  66  * value that collides with a value already being used), and use the
  67  * new header in captures of that type, so that programs that can
  68  * handle DLT_LINUX_SLL captures will continue to handle them correctly
  69  * without any change, and so that capture files with different headers
  70  * can be told apart and programs that read them can dissect the
  71  * packets in them.
  72  *
  73  * This structure, and the #defines below, must be the same in the
  74  * libpcap and tcpdump versions of "sll.h".
  75  */
  76
  77 /*
  78  * A DLT_LINUX_SLL fake link-layer header.
  79  */
  80 #define SLL_HDR_LEN     16              /* total header length */
  81 #define SLL_ADDRLEN     8               /* length of address field */
  82
  83 struct sll_header {
  84         u_int16_t       sll_pkttype;    /* packet type */
  85         u_int16_t       sll_hatype;     /* link-layer address type */
  86         u_int16_t       sll_halen;      /* link-layer address length */
  87         u_int8_t        sll_addr[SLL_ADDRLEN];  /* link-layer address */
  88         u_int16_t       sll_protocol;   /* protocol */
  89 };
  90
  91 /*
  92  * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the
  93  * PACKET_ values on Linux, but are defined here so that they're
  94  * available even on systems other than Linux, and so that they
  95  * don't change even if the PACKET_ values change.
  96  */
  97 #define LINUX_SLL_HOST          0
  98 #define LINUX_SLL_BROADCAST     1
  99 #define LINUX_SLL_MULTICAST     2
 100 #define LINUX_SLL_OTHERHOST     3
 101 #define LINUX_SLL_OUTGOING      4
 102
 103 /*
 104  * The LINUX_SLL_ values for "sll_protocol"; these correspond to the
 105  * ETH_P_ values on Linux, but are defined here so that they're
 106  * available even on systems other than Linux.  We assume, for now,
 107  * that the ETH_P_ values won't change in Linux; if they do, then:
 108  *
 109  *      if we don't translate them in "pcap-linux.c", capture files
 110  *      won't necessarily be readable if captured on a system that
 111  *      defines ETH_P_ values that don't match these values;
 112  *
 113  *      if we do translate them in "pcap-linux.c", that makes life
 114  *      unpleasant for the BPF code generator, as the values you test
 115  *      for in the kernel aren't the values that you test for when
 116  *      reading a capture file, so the fixup code run on BPF programs
 117  *      handed to the kernel ends up having to do more work.
 118  *
 119  * Add other values here as necessary, for handling packet types that
 120  * might show up on non-Ethernet, non-802.x networks.  (Not all the ones
 121  * in the Linux "if_ether.h" will, I suspect, actually show up in
 122  * captures.)
 123  */
 124 #define LINUX_SLL_P_802_3       0x0001  /* Novell 802.3 frames without 802.2 LLC header */
 125 #define LINUX_SLL_P_802_2       0x0004  /* 802.2 frames (not D/I/X Ethernet) */