contrib/tcpdump/sll.h

   1 /*-
   2  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from the Stanford/CMU enet packet filter,
   6  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
   7  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
   8  * Berkeley Laboratory.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  *
  38  * @(#) $Header: /tcpdump/master/tcpdump/sll.h,v 1.7.6.1 2008-05-30 01:38:21 guy Exp $ (LBL)
  39  */
  40
  41 /*
  42  * For captures on Linux cooked sockets, we construct a fake header
  43  * that includes:
  44  *
  45  *      a 2-byte "packet type" which is one of:
  46  *
  47  *              LINUX_SLL_HOST          packet was sent to us
  48  *              LINUX_SLL_BROADCAST     packet was broadcast
  49  *              LINUX_SLL_MULTICAST     packet was multicast
  50  *              LINUX_SLL_OTHERHOST     packet was sent to somebody else
  51  *              LINUX_SLL_OUTGOING      packet was sent *by* us;
  52  *
  53  *      a 2-byte Ethernet protocol field;
  54  *
  55  *      a 2-byte link-layer type;
  56  *
  57  *      a 2-byte link-layer address length;
  58  *
  59  *      an 8-byte source link-layer address, whose actual length is
  60  *      specified by the previous value.
  61  *
  62  * All fields except for the link-layer address are in network byte order.
  63  *
  64  * DO NOT change the layout of this structure, or change any of the
  65  * LINUX_SLL_ values below.  If you must change the link-layer header
  66  * for a "cooked" Linux capture, introduce a new DLT_ type (ask
  67  * "tcpdump-workers@lists.tcpdump.org" for one, so that you don't give it
  68  * a value that collides with a value already being used), and use the
  69  * new header in captures of that type, so that programs that can
  70  * handle DLT_LINUX_SLL captures will continue to handle them correctly
  71  * without any change, and so that capture files with different headers
  72  * can be told apart and programs that read them can dissect the
  73  * packets in them.
  74  *
  75  * This structure, and the #defines below, must be the same in the
  76  * libpcap and tcpdump versions of "sll.h".
  77  */
  78
  79 /*
  80  * A DLT_LINUX_SLL fake link-layer header.
  81  */
  82 #define SLL_HDR_LEN     16              /* total header length */
  83 #define SLL_ADDRLEN     8               /* length of address field */
  84
  85 struct sll_header {
  86         u_int16_t       sll_pkttype;    /* packet type */
  87         u_int16_t       sll_hatype;     /* link-layer address type */
  88         u_int16_t       sll_halen;      /* link-layer address length */
  89         u_int8_t        sll_addr[SLL_ADDRLEN];  /* link-layer address */
  90         u_int16_t       sll_protocol;   /* protocol */
  91 };
  92
  93 /*
  94  * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the
  95  * PACKET_ values on Linux, but are defined here so that they're
  96  * available even on systems other than Linux, and so that they
  97  * don't change even if the PACKET_ values change.
  98  */
  99 #define LINUX_SLL_HOST          0
 100 #define LINUX_SLL_BROADCAST     1
 101 #define LINUX_SLL_MULTICAST     2
 102 #define LINUX_SLL_OTHERHOST     3
 103 #define LINUX_SLL_OUTGOING      4
 104
 105 /*
 106  * The LINUX_SLL_ values for "sll_protocol"; these correspond to the
 107  * ETH_P_ values on Linux, but are defined here so that they're
 108  * available even on systems other than Linux.  We assume, for now,
 109  * that the ETH_P_ values won't change in Linux; if they do, then:
 110  *
 111  *      if we don't translate them in "pcap-linux.c", capture files
 112  *      won't necessarily be readable if captured on a system that
 113  *      defines ETH_P_ values that don't match these values;
 114  *
 115  *      if we do translate them in "pcap-linux.c", that makes life
 116  *      unpleasant for the BPF code generator, as the values you test
 117  *      for in the kernel aren't the values that you test for when
 118  *      reading a capture file, so the fixup code run on BPF programs
 119  *      handed to the kernel ends up having to do more work.
 120  *
 121  * Add other values here as necessary, for handling packet types that
 122  * might show up on non-Ethernet, non-802.x networks.  (Not all the ones
 123  * in the Linux "if_ether.h" will, I suspect, actually show up in
 124  * captures.)
 125  */
 126 #define LINUX_SLL_P_802_3       0x0001  /* Novell 802.3 frames without 802.2 LLC header */
 127 #define LINUX_SLL_P_802_2       0x0004  /* 802.2 frames (not D/I/X Ethernet) */