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 /*
41  * $Id: //depot/argus/argus/include/argus/sll.h#2 $
42  * $DateTime: 2011/01/26 17:16:43 $
43  * $Change: 2088 $
44  */
45 
46 #if !defined(sll_h)
47 #define sll_h
48 
49 /*
50  * For captures on Linux cooked sockets, we construct a fake header
51  * that includes:
52  *
53  *	a 2-byte "packet type" which is one of:
54  *
55  *		LINUX_SLL_HOST		packet was sent to us
56  *		LINUX_SLL_BROADCAST	packet was broadcast
57  *		LINUX_SLL_MULTICAST	packet was multicast
58  *		LINUX_SLL_OTHERHOST	packet was sent to somebody else
59  *		LINUX_SLL_OUTGOING	packet was sent *by* us;
60  *
61  *	a 2-byte Ethernet protocol field;
62  *
63  *	a 2-byte link-layer type;
64  *
65  *	a 2-byte link-layer address length;
66  *
67  *	an 8-byte source link-layer address, whose actual length is
68  *	specified by the previous value.
69  *
70  * All fields except for the link-layer address are in network byte order.
71  *
72  * DO NOT change the layout of this structure, or change any of the
73  * LINUX_SLL_ values below.  If you must change the link-layer header
74  * for a "cooked" Linux capture, introduce a new DLT_ type (ask
75  * "tcpdump-workers@tcpdump.org" for one, so that you don't give it a
76  * value that collides with a value already being used), and use the
77  * new header in captures of that type, so that programs that can
78  * handle DLT_LINUX_SLL captures will continue to handle them correctly
79  * without any change, and so that capture files with different headers
80  * can be told apart and programs that read them can dissect the
81  * packets in them.
82  *
83  * This structure, and the #defines below, must be the same in the
84  * libpcap and tcpdump versions of "sll.h".
85  */
86 
87 /*
88  * A DLT_LINUX_SLL fake link-layer header.
89  */
90 #define SLL_HDR_LEN	16		/* total header length */
91 #define SLL_ADDRLEN	8		/* length of address field */
92 
93 struct sll_header {
94 	u_short	sll_pkttype;	/* packet type */
95 	u_short	sll_hatype;	/* link-layer address type */
96 	u_short	sll_halen;	/* link-layer address length */
97 	u_char	sll_addr[SLL_ADDRLEN];	/* link-layer address */
98 	u_short	sll_protocol;	/* protocol */
99 };
100 
101 /*
102  * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the
103  * PACKET_ values on Linux, but are defined here so that they're
104  * available even on systems other than Linux, and so that they
105  * don't change even if the PACKET_ values change.
106  */
107 #define LINUX_SLL_HOST		0
108 #define LINUX_SLL_BROADCAST	1
109 #define LINUX_SLL_MULTICAST	2
110 #define LINUX_SLL_OTHERHOST	3
111 #define LINUX_SLL_OUTGOING	4
112 
113 /*
114  * The LINUX_SLL_ values for "sll_protocol"; these correspond to the
115  * ETH_P_ values on Linux, but are defined here so that they're
116  * available even on systems other than Linux.  We assume, for now,
117  * that the ETH_P_ values won't change in Linux; if they do, then:
118  *
119  *	if we don't translate them in "pcap-linux.c", capture files
120  *	won't necessarily be readable if captured on a system that
121  *	defines ETH_P_ values that don't match these values;
122  *
123  *	if we do translate them in "pcap-linux.c", that makes life
124  *	unpleasant for the BPF code generator, as the values you test
125  *	for in the kernel aren't the values that you test for when
126  *	reading a capture file, so the fixup code run on BPF programs
127  *	handed to the kernel ends up having to do more work.
128  *
129  * Add other values here as necessary, for handling packet types that
130  * might show up on non-Ethernet, non-802.x networks.  (Not all the ones
131  * in the Linux "if_ether.h" will, I suspect, actually show up in
132  * captures.)
133  */
134 #define LINUX_SLL_P_802_3	0x0001	/* Novell 802.3 frames without 802.2 LLC header */
135 #define LINUX_SLL_P_802_2	0x0004	/* 802.2 frames (not D/I/X Ethernet) */
136 #endif
137