1/* $NetBSD: sll.h,v 1.4 2018/09/03 15:26:44 christos Exp $ */
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. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the University of
23 * California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 * may be used to endorse or promote products derived from this software
26 * without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
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
76#ifndef lib_pcap_sll_h
77#define lib_pcap_sll_h
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#include <pcap/pcap-inttypes.h>
86
87struct sll_header {
88 uint16_t sll_pkttype; /* packet type */
89 uint16_t sll_hatype; /* link-layer address type */
90 uint16_t sll_halen; /* link-layer address length */
91 uint8_t sll_addr[SLL_ADDRLEN]; /* link-layer address */
92 uint16_t sll_protocol; /* protocol */
93};
94
95/*
96 * The LINUX_SLL_ values for "sll_pkttype"; these correspond to the
97 * PACKET_ values on Linux, but are defined here so that they're
98 * available even on systems other than Linux, and so that they
99 * don't change even if the PACKET_ values change.
100 */
101#define LINUX_SLL_HOST 0
102#define LINUX_SLL_BROADCAST 1
103#define LINUX_SLL_MULTICAST 2
104#define LINUX_SLL_OTHERHOST 3
105#define LINUX_SLL_OUTGOING 4
106
107/*
108 * The LINUX_SLL_ values for "sll_protocol"; these correspond to the
109 * ETH_P_ values on Linux, but are defined here so that they're
110 * available even on systems other than Linux. We assume, for now,
111 * that the ETH_P_ values won't change in Linux; if they do, then:
112 *
113 * if we don't translate them in "pcap-linux.c", capture files
114 * won't necessarily be readable if captured on a system that
115 * defines ETH_P_ values that don't match these values;
116 *
117 * if we do translate them in "pcap-linux.c", that makes life
118 * unpleasant for the BPF code generator, as the values you test
119 * for in the kernel aren't the values that you test for when
120 * reading a capture file, so the fixup code run on BPF programs
121 * handed to the kernel ends up having to do more work.
122 *
123 * Add other values here as necessary, for handling packet types that
124 * might show up on non-Ethernet, non-802.x networks. (Not all the ones
125 * in the Linux "if_ether.h" will, I suspect, actually show up in
126 * captures.)
127 */
128#define LINUX_SLL_P_802_3 0x0001 /* Novell 802.3 frames without 802.2 LLC header */
129#define LINUX_SLL_P_802_2 0x0004 /* 802.2 frames (not D/I/X Ethernet) */
130#define LINUX_SLL_P_CAN 0x000C /* CAN frames, with SocketCAN pseudo-headers */
131#define LINUX_SLL_P_CANFD 0x000D /* CAN FD frames, with SocketCAN pseudo-headers */
132
133#endif
134