libpcap  1.10.1
About: libpcap is a packet filter library used by tools like tcpdump.
  Fossies Dox: libpcap-1.10.1.tar.gz  ("unofficial" and yet experimental doxygen-generated source code documentation)  

sll.h
Go to the documentation of this file.
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 #include <pcap/pcap-inttypes.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 struct sll_header {
86  uint16_t sll_pkttype; /* packet type */
87  uint16_t sll_hatype; /* link-layer address type */
88  uint16_t sll_halen; /* link-layer address length */
89  uint8_t sll_addr[SLL_ADDRLEN]; /* link-layer address */
90  uint16_t sll_protocol; /* protocol */
91 };
92 
93 /*
94  * A DLT_LINUX_SLL2 fake link-layer header.
95  */
96 #define SLL2_HDR_LEN 20 /* total header length */
97 
98 struct sll2_header {
99  uint16_t sll2_protocol; /* protocol */
100  uint16_t sll2_reserved_mbz; /* reserved - must be zero */
101  uint32_t sll2_if_index; /* 1-based interface index */
102  uint16_t sll2_hatype; /* link-layer address type */
103  uint8_t sll2_pkttype; /* packet type */
104  uint8_t sll2_halen; /* link-layer address length */
105  uint8_t sll2_addr[SLL_ADDRLEN]; /* link-layer address */
106 };
107 
108 /*
109  * The LINUX_SLL_ values for "sll_pkttype" and LINUX_SLL2_ values for
110  * "sll2_pkttype"; these correspond to the PACKET_ values on Linux,
111  * which are defined by a header under include/uapi in the current
112  * kernel source, and are thus not going to change on Linux. We
113  * define them here so that they're available even on systems other
114  * than Linux.
115  */
116 #define LINUX_SLL_HOST 0
117 #define LINUX_SLL_BROADCAST 1
118 #define LINUX_SLL_MULTICAST 2
119 #define LINUX_SLL_OTHERHOST 3
120 #define LINUX_SLL_OUTGOING 4
121 
122 /*
123  * The LINUX_SLL_ values for "sll_protocol" and LINUX_SLL2_ values for
124  * "sll2_protocol"; these correspond to the ETH_P_ values on Linux, but
125  * are defined here so that they're available even on systems other than
126  * Linux. We assume, for now, that the ETH_P_ values won't change in
127  * Linux; if they do, then:
128  *
129  * if we don't translate them in "pcap-linux.c", capture files
130  * won't necessarily be readable if captured on a system that
131  * defines ETH_P_ values that don't match these values;
132  *
133  * if we do translate them in "pcap-linux.c", that makes life
134  * unpleasant for the BPF code generator, as the values you test
135  * for in the kernel aren't the values that you test for when
136  * reading a capture file, so the fixup code run on BPF programs
137  * handed to the kernel ends up having to do more work.
138  *
139  * Add other values here as necessary, for handling packet types that
140  * might show up on non-Ethernet, non-802.x networks. (Not all the ones
141  * in the Linux "if_ether.h" will, I suspect, actually show up in
142  * captures.)
143  */
144 #define LINUX_SLL_P_802_3 0x0001 /* Novell 802.3 frames without 802.2 LLC header */
145 #define LINUX_SLL_P_802_2 0x0004 /* 802.2 frames (not D/I/X Ethernet) */
146 #define LINUX_SLL_P_CAN 0x000C /* CAN frames, with SocketCAN pseudo-headers */
147 #define LINUX_SLL_P_CANFD 0x000D /* CAN FD frames, with SocketCAN pseudo-headers */
148 
149 #endif
#define SLL_ADDRLEN
Definition: sll.h:83
uint16_t sll2_protocol
Definition: sll.h:99
uint32_t sll2_if_index
Definition: sll.h:101
uint8_t sll2_addr[8]
Definition: sll.h:105
uint16_t sll2_hatype
Definition: sll.h:102
uint8_t sll2_halen
Definition: sll.h:104
uint8_t sll2_pkttype
Definition: sll.h:103
uint16_t sll2_reserved_mbz
Definition: sll.h:100
Definition: sll.h:85
uint8_t sll_addr[8]
Definition: sll.h:89
uint16_t sll_halen
Definition: sll.h:88
uint16_t sll_protocol
Definition: sll.h:90
uint16_t sll_hatype
Definition: sll.h:87
uint16_t sll_pkttype
Definition: sll.h:86