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
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@lists.tcpdump.org" for one, so that you don't give it
66 * a 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
74#ifndef lib_pcap_sll_h
75#define lib_pcap_sll_h
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
83struct 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) */
126
127#endif
128