xref: /netbsd/sys/net/dlt.h (revision bce879b8)
1 /*	$NetBSD: dlt.h,v 1.23 2022/05/28 21:14:57 andvar 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. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *      @(#)bpf.h       7.1 (Berkeley) 5/7/91
37  */
38 
39 #ifndef _NET_DLT_H_
40 #define _NET_DLT_H_
41 /*
42  * Link-layer header type codes.
43  *
44  * Do *NOT* add new values to this list without asking
45  * "tcpdump-workers@lists.tcpdump.org" for a value.  Otherwise, you run
46  * the risk of using a value that's already being used for some other
47  * purpose, and of having tools that read libpcap-format captures not
48  * being able to handle captures with your new DLT_ value, with no hope
49  * that they will ever be changed to do so (as that would destroy their
50  * ability to read captures using that value for that other purpose).
51  *
52  * See
53  *
54  *	https://www.tcpdump.org/linktypes.html
55  *
56  * for detailed descriptions of some of these link-layer header types.
57  */
58 
59 /*
60  * These are the types that are the same on all platforms, and that
61  * have been defined by <net/bpf.h> for ages.
62  */
63 #define DLT_NULL	0	/* BSD loopback encapsulation */
64 #define DLT_EN10MB	1	/* Ethernet (10Mb) */
65 #define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
66 #define DLT_AX25	3	/* Amateur Radio AX.25 */
67 #define DLT_PRONET	4	/* Proteon ProNET Token Ring */
68 #define DLT_CHAOS	5	/* Chaos */
69 #define DLT_IEEE802	6	/* 802.5 Token Ring */
70 #define DLT_ARCNET	7	/* ARCNET, with BSD-style header */
71 #define DLT_SLIP	8	/* Serial Line IP */
72 #define DLT_PPP		9	/* Point-to-point Protocol */
73 #define DLT_FDDI	10	/* FDDI */
74 
75 /*
76  * These are types that are different on some platforms, and that
77  * have been defined by <net/bpf.h> for ages.  We use #ifdefs to
78  * detect the BSDs that define them differently from the traditional
79  * libpcap <net/bpf.h>
80  *
81  * XXX - DLT_ATM_RFC1483 is 13 in BSD/OS, and DLT_RAW is 14 in BSD/OS,
82  * but I don't know what the right #define is for BSD/OS.
83  */
84 #define DLT_ATM_RFC1483	11	/* LLC-encapsulated ATM */
85 
86 #ifdef __OpenBSD__
87 #define DLT_RAW		14	/* raw IP */
88 #else
89 #define DLT_RAW		12	/* raw IP */
90 #endif
91 
92 /*
93  * Given that the only OS that currently generates BSD/OS SLIP or PPP
94  * is, well, BSD/OS, arguably everybody should have chosen its values
95  * for DLT_SLIP_BSDOS and DLT_PPP_BSDOS, which are 15 and 16, but they
96  * didn't.  So it goes.
97  */
98 #if defined(__NetBSD__) || defined(__FreeBSD__)
99 #ifndef DLT_SLIP_BSDOS
100 #define DLT_SLIP_BSDOS	13	/* BSD/OS Serial Line IP */
101 #define DLT_PPP_BSDOS	14	/* BSD/OS Point-to-point Protocol */
102 #define DLT_HIPPI	15	/* HIPPI */
103 #define DLT_HDLC	16	/* HDLC framing */
104 #endif
105 #else
106 #define DLT_SLIP_BSDOS	15	/* BSD/OS Serial Line IP */
107 #define DLT_PPP_BSDOS	16	/* BSD/OS Point-to-point Protocol */
108 #endif
109 
110 /*
111  * 17 was used for DLT_PFLOG in OpenBSD; it no longer is.
112  *
113  * It was DLT_LANE8023 in SuSE 6.3, so we defined LINKTYPE_PFLOG
114  * as 117 so that pflog captures would use a link-layer header type
115  * value that didn't collide with any other values.  On all
116  * platforms other than OpenBSD, we defined DLT_PFLOG as 117,
117  * and we mapped between LINKTYPE_PFLOG and DLT_PFLOG.
118  *
119  * OpenBSD eventually switched to using 117 for DLT_PFLOG as well.
120  *
121  * Don't use 17 for anything else.
122  */
123 #if defined(__OpenBSD__) || defined(__NetBSD__)
124 #define DLT_OLD_PFLOG	17
125 #endif
126 
127 /*
128  * 18 is used for DLT_PFSYNC in OpenBSD, NetBSD, DragonFly BSD and
129  * macOS; don't use it for anything else.  (FreeBSD uses 121, which
130  * collides with DLT_HHDLC, even though it doesn't use 18 for
131  * anything and doesn't appear to have ever used it for anything.)
132  *
133  * We define it as 18 on those platforms; it is, unfortunately, used
134  * for DLT_CIP in Suse 6.3, so we don't define it as DLT_PFSYNC
135  * in general.  As the packet format for it, like that for
136  * DLT_PFLOG, is not only OS-dependent but OS-version-dependent,
137  * we don't support printing it in tcpdump except on OSes that
138  * have the relevant header files, so it's not that useful on
139  * other platforms.
140  */
141 #if defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DragonFly__) || defined(__APPLE__)
142 #define DLT_PFSYNC	18
143 #endif
144 
145 #define DLT_ATM_CLIP	19	/* Linux Classical-IP over ATM */
146 
147 /*
148  * Apparently Redback uses this for its SmartEdge 400/800.  I hope
149  * nobody else decided to use it, too.
150  */
151 #define DLT_REDBACK_SMARTEDGE	32
152 
153 /*
154  * These values are defined by NetBSD; other platforms should refrain from
155  * using them for other purposes, so that NetBSD savefiles with link
156  * types of 50 or 51 can be read as this type on all platforms.
157  */
158 #define DLT_PPP_SERIAL	50	/* PPP over serial with HDLC encapsulation */
159 #define DLT_PPP_ETHER	51	/* PPP over Ethernet */
160 
161 /*
162  * The Axent Raptor firewall - now the Symantec Enterprise Firewall - uses
163  * a link-layer type of 99 for the tcpdump it supplies.  The link-layer
164  * header has 6 bytes of unknown data, something that appears to be an
165  * Ethernet type, and 36 bytes that appear to be 0 in at least one capture
166  * I've seen.
167  */
168 #define DLT_SYMANTEC_FIREWALL	99
169 
170 /*
171  * Values between 100 and 103 are used in capture file headers as
172  * link-layer header type LINKTYPE_ values corresponding to DLT_ types
173  * that differ between platforms; don't use those values for new DLT_
174  * new types.
175  */
176 
177 /*
178  * Values starting with 104 are used for newly-assigned link-layer
179  * header type values; for those link-layer header types, the DLT_
180  * value returned by pcap_datalink() and passed to pcap_open_dead(),
181  * and the LINKTYPE_ value that appears in capture files, are the
182  * same.
183  *
184  * DLT_MATCHING_MIN is the lowest such value; DLT_MATCHING_MAX is
185  * the highest such value.
186  */
187 #define DLT_MATCHING_MIN	104
188 
189 /*
190  * This value was defined by libpcap 0.5; platforms that have defined
191  * it with a different value should define it here with that value -
192  * a link type of 104 in a save file will be mapped to DLT_C_HDLC,
193  * whatever value that happens to be, so programs will correctly
194  * handle files with that link type regardless of the value of
195  * DLT_C_HDLC.
196  *
197  * The name DLT_C_HDLC was used by BSD/OS; we use that name for source
198  * compatibility with programs written for BSD/OS.
199  *
200  * libpcap 0.5 defined it as DLT_CHDLC; we define DLT_CHDLC as well,
201  * for source compatibility with programs written for libpcap 0.5.
202  */
203 #define DLT_C_HDLC	104	/* Cisco HDLC */
204 #define DLT_CHDLC	DLT_C_HDLC
205 
206 #define DLT_IEEE802_11	105	/* IEEE 802.11 wireless */
207 
208 /*
209  * 106 is reserved for Linux Classical IP over ATM; it's like DLT_RAW,
210  * except when it isn't.  (I.e., sometimes it's just raw IP, and
211  * sometimes it isn't.)  We currently handle it as DLT_LINUX_SLL,
212  * so that we don't have to worry about the link-layer header.)
213  */
214 
215 /*
216  * Frame Relay; BSD/OS has a DLT_FR with a value of 11, but that collides
217  * with other values.
218  * DLT_FR and DLT_FRELAY packets start with the Q.922 Frame Relay header
219  * (DLCI, etc.).
220  */
221 #define DLT_FRELAY	107
222 
223 /*
224  * OpenBSD DLT_LOOP, for loopback devices; it's like DLT_NULL, except
225  * that the AF_ type in the link-layer header is in network byte order.
226  *
227  * DLT_LOOP is 12 in OpenBSD, but that's DLT_RAW in other OSes, so
228  * we don't use 12 for it in OSes other than OpenBSD.
229  */
230 #ifdef __OpenBSD__
231 #define DLT_LOOP	12
232 #else
233 #define DLT_LOOP	108
234 #endif
235 
236 /*
237  * Encapsulated packets for IPsec; DLT_ENC is 13 in OpenBSD, but that's
238  * DLT_SLIP_BSDOS in NetBSD, so we don't use 13 for it in OSes other
239  * than OpenBSD.
240  */
241 #ifdef __OpenBSD__
242 #define DLT_ENC		13
243 #else
244 #define DLT_ENC		109
245 #endif
246 
247 /*
248  * Values between 110 and 112 are reserved for use in capture file headers
249  * as link-layer types corresponding to DLT_ types that might differ
250  * between platforms; don't use those values for new DLT_ types
251  * other than the corresponding DLT_ types.
252  */
253 
254 /*
255  * Linux cooked sockets.
256  */
257 #define DLT_LINUX_SLL	113
258 
259 /*
260  * Apple LocalTalk hardware.
261  */
262 #define DLT_LTALK	114
263 
264 /*
265  * Acorn Econet.
266  */
267 #define DLT_ECONET	115
268 
269 /*
270  * Reserved for use with OpenBSD ipfilter.
271  */
272 #define DLT_IPFILTER	116
273 
274 /*
275  * OpenBSD DLT_PFLOG.
276  */
277 #define DLT_PFLOG	117
278 
279 /*
280  * Registered for Cisco-internal use.
281  */
282 #define DLT_CISCO_IOS	118
283 
284 /*
285  * For 802.11 cards using the Prism II chips, with a link-layer
286  * header including Prism monitor mode information plus an 802.11
287  * header.
288  */
289 #define DLT_PRISM_HEADER	119
290 
291 /*
292  * Reserved for Aironet 802.11 cards, with an Aironet link-layer header
293  * (see Doug Ambrisko's FreeBSD patches).
294  */
295 #define DLT_AIRONET_HEADER	120
296 
297 /*
298  * Sigh.
299  *
300  * 121 was reserved for Siemens HiPath HDLC on 2002-01-25, as
301  * requested by Tomas Kukosa.
302  *
303  * On 2004-02-25, a FreeBSD checkin to sys/net/bpf.h was made that
304  * assigned 121 as DLT_PFSYNC.  In current versions, its libpcap
305  * does DLT_ <-> LINKTYPE_ mapping, mapping DLT_PFSYNC to a
306  * LINKTYPE_PFSYNC value of 246, so it should write out DLT_PFSYNC
307  * dump files with 246 as the link-layer header type.  (Earlier
308  * versions might not have done mapping, in which case they would
309  * have written them out with a link-layer header type of 121.)
310  *
311  * OpenBSD, from which pf came, however, uses 18 for DLT_PFSYNC;
312  * its libpcap does no DLT_ <-> LINKTYPE_ mapping, so it would
313  * write out DLT_PFSYNC dump files with use 18 as the link-layer
314  * header type.
315  *
316  * NetBSD, DragonFly BSD, and Darwin also use 18 for DLT_PFSYNC; in
317  * current versions, their libpcaps do DLT_ <-> LINKTYPE_ mapping,
318  * mapping DLT_PFSYNC to a LINKTYPE_PFSYNC value of 246, so they
319  * should write out DLT_PFSYNC dump files with 246 as the link-layer
320  * header type.  (Earlier versions might not have done mapping,
321  * in which case they'd work the same way OpenBSD does, writing
322  * them out with a link-layer header type of 18.)
323  *
324  * We'll define DLT_PFSYNC as:
325  *
326  *    18 on NetBSD, OpenBSD, DragonFly BSD, and Darwin;
327  *
328  *    121 on FreeBSD;
329  *
330  *    246 everywhere else.
331  *
332  * We'll define DLT_HHDLC as 121 on everything except for FreeBSD;
333  * anybody who wants to compile, on FreeBSD, code that uses DLT_HHDLC
334  * is out of luck.
335  *
336  * We'll define LINKTYPE_PFSYNC as 246 on *all* platforms, so that
337  * savefiles written using *this* code won't use 18 or 121 for PFSYNC,
338  * they'll all use 246.
339  *
340  * Code that uses pcap_datalink() to determine the link-layer header
341  * type of a savefile won't, when built and run on FreeBSD, be able
342  * to distinguish between LINKTYPE_PFSYNC and LINKTYPE_HHDLC capture
343  * files, as pcap_datalink() will give 121 for both of them.  Code
344  * that doesn't, such as the code in Wireshark, will be able to
345  * distinguish between them.
346  *
347  * FreeBSD's libpcap won't map a link-layer header type of 18 - i.e.,
348  * DLT_PFSYNC files from OpenBSD and possibly older versions of NetBSD,
349  * DragonFly BSD, and macOS - to DLT_PFSYNC, so code built with FreeBSD's
350  * libpcap won't treat those files as DLT_PFSYNC files.
351  *
352  * Other libpcaps won't map a link-layer header type of 121 to DLT_PFSYNC;
353  * this means they can read DLT_HHDLC files, if any exist, but won't
354  * treat pcap files written by any older versions of FreeBSD libpcap that
355  * didn't map to 246 as DLT_PFSYNC files.
356  */
357 #ifdef __FreeBSD__
358 #define DLT_PFSYNC		121
359 #else
360 #define DLT_HHDLC		121
361 #endif
362 
363 /*
364  * This is for RFC 2625 IP-over-Fibre Channel.
365  *
366  * This is not for use with raw Fibre Channel, where the link-layer
367  * header starts with a Fibre Channel frame header; it's for IP-over-FC,
368  * where the link-layer header starts with an RFC 2625 Network_Header
369  * field.
370  */
371 #define DLT_IP_OVER_FC		122
372 
373 /*
374  * This is for Full Frontal ATM on Solaris with SunATM, with a
375  * pseudo-header followed by an AALn PDU.
376  *
377  * There may be other forms of Full Frontal ATM on other OSes,
378  * with different pseudo-headers.
379  *
380  * If ATM software returns a pseudo-header with VPI/VCI information
381  * (and, ideally, packet type information, e.g. signalling, ILMI,
382  * LANE, LLC-multiplexed traffic, etc.), it should not use
383  * DLT_ATM_RFC1483, but should get a new DLT_ value, so tcpdump
384  * and the like don't have to infer the presence or absence of a
385  * pseudo-header and the form of the pseudo-header.
386  */
387 #define DLT_SUNATM		123	/* Solaris+SunATM */
388 
389 /*
390  * Reserved as per request from Kent Dahlgren <kent@praesum.com>
391  * for private use.
392  */
393 #define DLT_RIO                 124     /* RapidIO */
394 #define DLT_PCI_EXP             125     /* PCI Express */
395 #define DLT_AURORA              126     /* Xilinx Aurora link layer */
396 
397 /*
398  * Header for 802.11 plus a number of bits of link-layer information
399  * including radio information, used by some recent BSD drivers as
400  * well as the madwifi Atheros driver for Linux.
401  */
402 #define DLT_IEEE802_11_RADIO	127	/* 802.11 plus radiotap radio header */
403 
404 /*
405  * Reserved for the TZSP encapsulation, as per request from
406  * Chris Waters <chris.waters@networkchemistry.com>
407  * TZSP is a generic encapsulation for any other link type,
408  * which includes a means to include meta-information
409  * with the packet, e.g. signal strength and channel
410  * for 802.11 packets.
411  */
412 #define DLT_TZSP                128     /* Tazmen Sniffer Protocol */
413 
414 /*
415  * BSD's ARCNET headers have the source host, destination host,
416  * and type at the beginning of the packet; that's what's handed
417  * up to userland via BPF.
418  *
419  * Linux's ARCNET headers, however, have a 2-byte offset field
420  * between the host IDs and the type; that's what's handed up
421  * to userland via PF_PACKET sockets.
422  *
423  * We therefore have to have separate DLT_ values for them.
424  */
425 #define DLT_ARCNET_LINUX	129	/* ARCNET */
426 
427 /*
428  * Juniper-private data link types, as per request from
429  * Hannes Gredler <hannes@juniper.net>.  The DLT_s are used
430  * for passing on chassis-internal metainformation such as
431  * QOS profiles, etc..
432  */
433 #define DLT_JUNIPER_MLPPP       130
434 #define DLT_JUNIPER_MLFR        131
435 #define DLT_JUNIPER_ES          132
436 #define DLT_JUNIPER_GGSN        133
437 #define DLT_JUNIPER_MFR         134
438 #define DLT_JUNIPER_ATM2        135
439 #define DLT_JUNIPER_SERVICES    136
440 #define DLT_JUNIPER_ATM1        137
441 
442 /*
443  * Apple IP-over-IEEE 1394, as per a request from Dieter Siegmund
444  * <dieter@apple.com>.  The header that's presented is an Ethernet-like
445  * header:
446  *
447  *	#define FIREWIRE_EUI64_LEN	8
448  *	struct firewire_header {
449  *		u_char  firewire_dhost[FIREWIRE_EUI64_LEN];
450  *		u_char  firewire_shost[FIREWIRE_EUI64_LEN];
451  *		u_short firewire_type;
452  *	};
453  *
454  * with "firewire_type" being an Ethernet type value, rather than,
455  * for example, raw GASP frames being handed up.
456  */
457 #define DLT_APPLE_IP_OVER_IEEE1394	138
458 
459 /*
460  * Various SS7 encapsulations, as per a request from Jeff Morriss
461  * <jeff.morriss[AT]ulticom.com> and subsequent discussions.
462  */
463 #define DLT_MTP2_WITH_PHDR	139	/* pseudo-header with various info, followed by MTP2 */
464 #define DLT_MTP2		140	/* MTP2, without pseudo-header */
465 #define DLT_MTP3		141	/* MTP3, without pseudo-header or MTP2 */
466 #define DLT_SCCP		142	/* SCCP, without pseudo-header or MTP2 or MTP3 */
467 
468 /*
469  * DOCSIS MAC frames.
470  */
471 #define DLT_DOCSIS		143
472 
473 /*
474  * Linux-IrDA packets. Protocol defined at http://www.irda.org.
475  * Those packets include IrLAP headers and above (IrLMP...), but
476  * don't include Phy framing (SOF/EOF/CRC & byte stuffing), because Phy
477  * framing can be handled by the hardware and depend on the bitrate.
478  * This is exactly the format you would get capturing on a Linux-IrDA
479  * interface (irdaX), but not on a raw serial port.
480  * Note the capture is done in "Linux-cooked" mode, so each packet include
481  * a fake packet header (struct sll_header). This is because IrDA packet
482  * decoding is dependant on the direction of the packet (incoming or
483  * outgoing).
484  * When/if other platform implement IrDA capture, we may revisit the
485  * issue and define a real DLT_IRDA...
486  * Jean II
487  */
488 #define DLT_LINUX_IRDA		144
489 
490 /*
491  * Reserved for IBM SP switch and IBM Next Federation switch.
492  */
493 #define DLT_IBM_SP		145
494 #define DLT_IBM_SN		146
495 
496 /*
497  * Reserved for private use.  If you have some link-layer header type
498  * that you want to use within your organization, with the capture files
499  * using that link-layer header type not ever be sent outside your
500  * organization, you can use these values.
501  *
502  * No libpcap release will use these for any purpose, nor will any
503  * tcpdump release use them, either.
504  *
505  * Do *NOT* use these in capture files that you expect anybody not using
506  * your private versions of capture-file-reading tools to read; in
507  * particular, do *NOT* use them in products, otherwise you may find that
508  * people won't be able to use tcpdump, or snort, or Ethereal, or... to
509  * read capture files from your firewall/intrusion detection/traffic
510  * monitoring/etc. appliance, or whatever product uses that DLT_ value,
511  * and you may also find that the developers of those applications will
512  * not accept patches to let them read those files.
513  *
514  * Also, do not use them if somebody might send you a capture using them
515  * for *their* private type and tools using them for *your* private type
516  * would have to read them.
517  *
518  * Instead, ask "tcpdump-workers@lists.tcpdump.org" for a new DLT_ value,
519  * as per the comment above, and use the type you're given.
520  */
521 #define DLT_USER0		147
522 #define DLT_USER1		148
523 #define DLT_USER2		149
524 #define DLT_USER3		150
525 #define DLT_USER4		151
526 #define DLT_USER5		152
527 #define DLT_USER6		153
528 #define DLT_USER7		154
529 #define DLT_USER8		155
530 #define DLT_USER9		156
531 #define DLT_USER10		157
532 #define DLT_USER11		158
533 #define DLT_USER12		159
534 #define DLT_USER13		160
535 #define DLT_USER14		161
536 #define DLT_USER15		162
537 
538 /*
539  * For future use with 802.11 captures - defined by AbsoluteValue
540  * Systems to store a number of bits of link-layer information
541  * including radio information:
542  *
543  *	http://www.shaftnet.org/~pizza/software/capturefrm.txt
544  *
545  * but it might be used by some non-AVS drivers now or in the
546  * future.
547  */
548 #define DLT_IEEE802_11_RADIO_AVS 163	/* 802.11 plus AVS radio header */
549 
550 /*
551  * Juniper-private data link type, as per request from
552  * Hannes Gredler <hannes@juniper.net>.  The DLT_s are used
553  * for passing on chassis-internal metainformation such as
554  * QOS profiles, etc..
555  */
556 #define DLT_JUNIPER_MONITOR     164
557 
558 /*
559  * BACnet MS/TP frames.
560  */
561 #define DLT_BACNET_MS_TP	165
562 
563 /*
564  * Another PPP variant as per request from Karsten Keil <kkeil@suse.de>.
565  *
566  * This is used in some OSes to allow a kernel socket filter to distinguish
567  * between incoming and outgoing packets, on a socket intended to
568  * supply pppd with outgoing packets so it can do dial-on-demand and
569  * hangup-on-lack-of-demand; incoming packets are filtered out so they
570  * don't cause pppd to hold the connection up (you don't want random
571  * input packets such as port scans, packets from old lost connections,
572  * etc. to force the connection to stay up).
573  *
574  * The first byte of the PPP header (0xff03) is modified to accommodate
575  * the direction - 0x00 = IN, 0x01 = OUT.
576  */
577 #define DLT_PPP_PPPD		166
578 
579 /*
580  * Names for backwards compatibility with older versions of some PPP
581  * software; new software should use DLT_PPP_PPPD.
582  */
583 #define DLT_PPP_WITH_DIRECTION	DLT_PPP_PPPD
584 #define DLT_LINUX_PPP_WITHDIRECTION	DLT_PPP_PPPD
585 
586 /*
587  * Juniper-private data link type, as per request from
588  * Hannes Gredler <hannes@juniper.net>.  The DLT_s are used
589  * for passing on chassis-internal metainformation such as
590  * QOS profiles, cookies, etc..
591  */
592 #define DLT_JUNIPER_PPPOE       167
593 #define DLT_JUNIPER_PPPOE_ATM   168
594 
595 #define DLT_GPRS_LLC		169	/* GPRS LLC */
596 #define DLT_GPF_T		170	/* GPF-T (ITU-T G.7041/Y.1303) */
597 #define DLT_GPF_F		171	/* GPF-F (ITU-T G.7041/Y.1303) */
598 
599 /*
600  * Requested by Oolan Zimmer <oz@gcom.com> for use in Gcom's T1/E1 line
601  * monitoring equipment.
602  */
603 #define DLT_GCOM_T1E1		172
604 #define DLT_GCOM_SERIAL		173
605 
606 /*
607  * Juniper-private data link type, as per request from
608  * Hannes Gredler <hannes@juniper.net>.  The DLT_ is used
609  * for internal communication to Physical Interface Cards (PIC)
610  */
611 #define DLT_JUNIPER_PIC_PEER    174
612 
613 /*
614  * Link types requested by Gregor Maier <gregor@endace.com> of Endace
615  * Measurement Systems.  They add an ERF header (see
616  * http://www.endace.com/support/EndaceRecordFormat.pdf) in front of
617  * the link-layer header.
618  */
619 #define DLT_ERF_ETH		175	/* Ethernet */
620 #define DLT_ERF_POS		176	/* Packet-over-SONET */
621 
622 /*
623  * Requested by Daniele Orlandi <daniele@orlandi.com> for raw LAPD
624  * for vISDN (http://www.orlandi.com/visdn/).  Its link-layer header
625  * includes additional information before the LAPD header, so it's
626  * not necessarily a generic LAPD header.
627  */
628 #define DLT_LINUX_LAPD		177
629 
630 /*
631  * Juniper-private data link type, as per request from
632  * Hannes Gredler <hannes@juniper.net>.
633  * The DLT_ are used for prepending meta-information
634  * like interface index, interface name
635  * before standard Ethernet, PPP, Frelay & C-HDLC Frames
636  */
637 #define DLT_JUNIPER_ETHER       178
638 #define DLT_JUNIPER_PPP         179
639 #define DLT_JUNIPER_FRELAY      180
640 #define DLT_JUNIPER_CHDLC       181
641 
642 /*
643  * Multi Link Frame Relay (FRF.16)
644  */
645 #define DLT_MFR                 182
646 
647 /*
648  * Juniper-private data link type, as per request from
649  * Hannes Gredler <hannes@juniper.net>.
650  * The DLT_ is used for internal communication with a
651  * voice Adapter Card (PIC)
652  */
653 #define DLT_JUNIPER_VP          183
654 
655 /*
656  * Arinc 429 frames.
657  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
658  * Every frame contains a 32bit A429 label.
659  * More documentation on Arinc 429 can be found at
660  * http://www.condoreng.com/support/downloads/tutorials/ARINCTutorial.pdf
661  */
662 #define DLT_A429                184
663 
664 /*
665  * Arinc 653 Interpartition Communication messages.
666  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
667  * Please refer to the A653-1 standard for more information.
668  */
669 #define DLT_A653_ICM            185
670 
671 /*
672  * This used to be "USB packets, beginning with a USB setup header;
673  * requested by Paolo Abeni <paolo.abeni@email.it>."
674  *
675  * However, that header didn't work all that well - it left out some
676  * useful information - and was abandoned in favor of the DLT_USB_LINUX
677  * header.
678  *
679  * This is now used by FreeBSD for its BPF taps for USB; that has its
680  * own headers.  So it is written, so it is done.
681  *
682  * For source-code compatibility, we also define DLT_USB to have this
683  * value.  We do it numerically so that, if code that includes this
684  * file (directly or indirectly) also includes an OS header that also
685  * defines DLT_USB as 186, we don't get a redefinition warning.
686  * (NetBSD 7 does that.)
687  */
688 #define DLT_USB_FREEBSD		186
689 #define DLT_USB			186
690 
691 /*
692  * Bluetooth HCI UART transport layer (part H:4); requested by
693  * Paolo Abeni.
694  */
695 #define DLT_BLUETOOTH_HCI_H4	187
696 
697 /*
698  * IEEE 802.16 MAC Common Part Sublayer; requested by Maria Cruz
699  * <cruz_petagay@bah.com>.
700  */
701 #define DLT_IEEE802_16_MAC_CPS	188
702 
703 /*
704  * USB packets, beginning with a Linux USB header; requested by
705  * Paolo Abeni <paolo.abeni@email.it>.
706  */
707 #define DLT_USB_LINUX		189
708 
709 /*
710  * Controller Area Network (CAN) v. 2.0B packets.
711  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
712  * Used to dump CAN packets coming from a CAN Vector board.
713  * More documentation on the CAN v2.0B frames can be found at
714  * http://www.can-cia.org/downloads/?269
715  */
716 #define DLT_CAN20B              190
717 
718 /*
719  * IEEE 802.15.4, with address fields padded, as is done by Linux
720  * drivers; requested by Juergen Schimmer.
721  */
722 #define DLT_IEEE802_15_4_LINUX	191
723 
724 /*
725  * Per Packet Information encapsulated packets.
726  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
727  */
728 #define DLT_PPI			192
729 
730 /*
731  * Header for 802.16 MAC Common Part Sublayer plus a radiotap radio header;
732  * requested by Charles Clancy.
733  */
734 #define DLT_IEEE802_16_MAC_CPS_RADIO	193
735 
736 /*
737  * Juniper-private data link type, as per request from
738  * Hannes Gredler <hannes@juniper.net>.
739  * The DLT_ is used for internal communication with a
740  * integrated service module (ISM).
741  */
742 #define DLT_JUNIPER_ISM         194
743 
744 /*
745  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
746  * nothing); requested by Mikko Saarnivala <mikko.saarnivala@sensinode.com>.
747  * For this one, we expect the FCS to be present at the end of the frame;
748  * if the frame has no FCS, DLT_IEEE802_15_4_NOFCS should be used.
749  *
750  * We keep the name DLT_IEEE802_15_4 as an alias for backwards
751  * compatibility, but, again, this should *only* be used for 802.15.4
752  * frames that include the FCS.
753  */
754 #define DLT_IEEE802_15_4_WITHFCS	195
755 #define DLT_IEEE802_15_4		DLT_IEEE802_15_4_WITHFCS
756 
757 /*
758  * Various link-layer types, with a pseudo-header, for SITA
759  * (http://www.sita.aero/); requested by Fulko Hew (fulko.hew@gmail.com).
760  */
761 #define DLT_SITA		196
762 
763 /*
764  * Various link-layer types, with a pseudo-header, for Endace DAG cards;
765  * encapsulates Endace ERF records.  Requested by Stephen Donnelly
766  * <stephen@endace.com>.
767  */
768 #define DLT_ERF			197
769 
770 /*
771  * Special header prepended to Ethernet packets when capturing from a
772  * u10 Networks board.  Requested by Phil Mulholland
773  * <phil@u10networks.com>.
774  */
775 #define DLT_RAIF1		198
776 
777 /*
778  * IPMB packet for IPMI, beginning with a 2-byte header, followed by
779  * the I2C slave address, followed by the netFn and LUN, etc..
780  * Requested by Chanthy Toeung <chanthy.toeung@ca.kontron.com>.
781  *
782  * XXX - this used to be called DLT_IPMB, back when we got the
783  * impression from the email thread requesting it that the packet
784  * had no extra 2-byte header.  We've renamed it; if anybody used
785  * DLT_IPMB and assumed no 2-byte header, this will cause the compile
786  * to fail, at which point we'll have to figure out what to do about
787  * the two header types using the same DLT_/LINKTYPE_ value.  If that
788  * doesn't happen, we'll assume nobody used it and that the redefinition
789  * is safe.
790  */
791 #define DLT_IPMB_KONTRON	199
792 
793 /*
794  * Juniper-private data link type, as per request from
795  * Hannes Gredler <hannes@juniper.net>.
796  * The DLT_ is used for capturing data on a secure tunnel interface.
797  */
798 #define DLT_JUNIPER_ST          200
799 
800 /*
801  * Bluetooth HCI UART transport layer (part H:4), with pseudo-header
802  * that includes direction information; requested by Paolo Abeni.
803  */
804 #define DLT_BLUETOOTH_HCI_H4_WITH_PHDR	201
805 
806 /*
807  * AX.25 packet with a 1-byte KISS header; see
808  *
809  *	http://www.ax25.net/kiss.htm
810  *
811  * as per Richard Stearn <richard@rns-stearn.demon.co.uk>.
812  */
813 #define DLT_AX25_KISS		202
814 
815 /*
816  * LAPD packets from an ISDN channel, starting with the address field,
817  * with no pseudo-header.
818  * Requested by Varuna De Silva <varunax@gmail.com>.
819  */
820 #define DLT_LAPD		203
821 
822 /*
823  * PPP, with a one-byte direction pseudo-header prepended - zero means
824  * "received by this host", non-zero (any non-zero value) means "sent by
825  * this host" - as per Will Barker <w.barker@zen.co.uk>.
826  */
827 #define DLT_PPP_WITH_DIR	204	/* Don't confuse with DLT_PPP_WITH_DIRECTION */
828 
829 /*
830  * Cisco HDLC, with a one-byte direction pseudo-header prepended - zero
831  * means "received by this host", non-zero (any non-zero value) means
832  * "sent by this host" - as per Will Barker <w.barker@zen.co.uk>.
833  */
834 #define DLT_C_HDLC_WITH_DIR	205
835 
836 /*
837  * Frame Relay, with a one-byte direction pseudo-header prepended - zero
838  * means "received by this host" (DCE -> DTE), non-zero (any non-zero
839  * value) means "sent by this host" (DTE -> DCE) - as per Will Barker
840  * <w.barker@zen.co.uk>.
841  */
842 #define DLT_FRELAY_WITH_DIR	206
843 
844 /*
845  * LAPB, with a one-byte direction pseudo-header prepended - zero means
846  * "received by this host" (DCE -> DTE), non-zero (any non-zero value)
847  * means "sent by this host" (DTE -> DCE)- as per Will Barker
848  * <w.barker@zen.co.uk>.
849  */
850 #define DLT_LAPB_WITH_DIR	207
851 
852 /*
853  * 208 is reserved for an as-yet-unspecified proprietary link-layer
854  * type, as requested by Will Barker.
855  */
856 
857 /*
858  * IPMB with a Linux-specific pseudo-header; as requested by Alexey Neyman
859  * <avn@pigeonpoint.com>.
860  */
861 #define DLT_IPMB_LINUX		209
862 
863 /*
864  * FlexRay automotive bus - http://www.flexray.com/ - as requested
865  * by Hannes Kaelber <hannes.kaelber@x2e.de>.
866  */
867 #define DLT_FLEXRAY		210
868 
869 /*
870  * Media Oriented Systems Transport (MOST) bus for multimedia
871  * transport - http://www.mostcooperation.com/ - as requested
872  * by Hannes Kaelber <hannes.kaelber@x2e.de>.
873  */
874 #define DLT_MOST		211
875 
876 /*
877  * Local Interconnect Network (LIN) bus for vehicle networks -
878  * http://www.lin-subbus.org/ - as requested by Hannes Kaelber
879  * <hannes.kaelber@x2e.de>.
880  */
881 #define DLT_LIN			212
882 
883 /*
884  * X2E-private data link type used for serial line capture,
885  * as requested by Hannes Kaelber <hannes.kaelber@x2e.de>.
886  */
887 #define DLT_X2E_SERIAL		213
888 
889 /*
890  * X2E-private data link type used for the Xoraya data logger
891  * family, as requested by Hannes Kaelber <hannes.kaelber@x2e.de>.
892  */
893 #define DLT_X2E_XORAYA		214
894 
895 /*
896  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
897  * nothing), but with the PHY-level data for non-ASK PHYs (4 octets
898  * of 0 as preamble, one octet of SFD, one octet of frame length+
899  * reserved bit, and then the MAC-layer data, starting with the
900  * frame control field).
901  *
902  * Requested by Max Filippov <jcmvbkbc@gmail.com>.
903  */
904 #define DLT_IEEE802_15_4_NONASK_PHY	215
905 
906 /*
907  * David Gibson <david@gibson.dropbear.id.au> requested this for
908  * captures from the Linux kernel /dev/input/eventN devices. This
909  * is used to communicate keystrokes and mouse movements from the
910  * Linux kernel to display systems, such as Xorg.
911  */
912 #define DLT_LINUX_EVDEV		216
913 
914 /*
915  * GSM Um and Abis interfaces, preceded by a "gsmtap" header.
916  *
917  * Requested by Harald Welte <laforge@gnumonks.org>.
918  */
919 #define DLT_GSMTAP_UM		217
920 #define DLT_GSMTAP_ABIS		218
921 
922 /*
923  * MPLS, with an MPLS label as the link-layer header.
924  * Requested by Michele Marchetto <michele@openbsd.org> on behalf
925  * of OpenBSD.
926  */
927 #define DLT_MPLS		219
928 
929 /*
930  * USB packets, beginning with a Linux USB header, with the USB header
931  * padded to 64 bytes; required for memory-mapped access.
932  */
933 #define DLT_USB_LINUX_MMAPPED	220
934 
935 /*
936  * DECT packets, with a pseudo-header; requested by
937  * Matthias Wenzel <tcpdump@mazzoo.de>.
938  */
939 #define DLT_DECT		221
940 
941 /*
942  * From: "Lidwa, Eric (GSFC-582.0)[SGT INC]" <eric.lidwa-1@nasa.gov>
943  * Date: Mon, 11 May 2009 11:18:30 -0500
944  *
945  * DLT_AOS. We need it for AOS Space Data Link Protocol.
946  *   I have already written dissectors for but need an OK from
947  *   legal before I can submit a patch.
948  *
949  */
950 #define DLT_AOS                 222
951 
952 /*
953  * Wireless HART (Highway Addressable Remote Transducer)
954  * From the HART Communication Foundation
955  * IES/PAS 62591
956  *
957  * Requested by Sam Roberts <vieuxtech@gmail.com>.
958  */
959 #define DLT_WIHART		223
960 
961 /*
962  * Fibre Channel FC-2 frames, beginning with a Frame_Header.
963  * Requested by Kahou Lei <kahou82@gmail.com>.
964  */
965 #define DLT_FC_2		224
966 
967 /*
968  * Fibre Channel FC-2 frames, beginning with an encoding of the
969  * SOF, and ending with an encoding of the EOF.
970  *
971  * The encodings represent the frame delimiters as 4-byte sequences
972  * representing the corresponding ordered sets, with K28.5
973  * represented as 0xBC, and the D symbols as the corresponding
974  * byte values; for example, SOFi2, which is K28.5 - D21.5 - D1.2 - D21.2,
975  * is represented as 0xBC 0xB5 0x55 0x55.
976  *
977  * Requested by Kahou Lei <kahou82@gmail.com>.
978  */
979 #define DLT_FC_2_WITH_FRAME_DELIMS	225
980 
981 /*
982  * Solaris ipnet pseudo-header; requested by Darren Reed <Darren.Reed@Sun.COM>.
983  *
984  * The pseudo-header starts with a one-byte version number; for version 2,
985  * the pseudo-header is:
986  *
987  * struct dl_ipnetinfo {
988  *     uint8_t   dli_version;
989  *     uint8_t   dli_family;
990  *     uint16_t  dli_htype;
991  *     uint32_t  dli_pktlen;
992  *     uint32_t  dli_ifindex;
993  *     uint32_t  dli_grifindex;
994  *     uint32_t  dli_zsrc;
995  *     uint32_t  dli_zdst;
996  * };
997  *
998  * dli_version is 2 for the current version of the pseudo-header.
999  *
1000  * dli_family is a Solaris address family value, so it's 2 for IPv4
1001  * and 26 for IPv6.
1002  *
1003  * dli_htype is a "hook type" - 0 for incoming packets, 1 for outgoing
1004  * packets, and 2 for packets arriving from another zone on the same
1005  * machine.
1006  *
1007  * dli_pktlen is the length of the packet data following the pseudo-header
1008  * (so the captured length minus dli_pktlen is the length of the
1009  * pseudo-header, assuming the entire pseudo-header was captured).
1010  *
1011  * dli_ifindex is the interface index of the interface on which the
1012  * packet arrived.
1013  *
1014  * dli_grifindex is the group interface index number (for IPMP interfaces).
1015  *
1016  * dli_zsrc is the zone identifier for the source of the packet.
1017  *
1018  * dli_zdst is the zone identifier for the destination of the packet.
1019  *
1020  * A zone number of 0 is the global zone; a zone number of 0xffffffff
1021  * means that the packet arrived from another host on the network, not
1022  * from another zone on the same machine.
1023  *
1024  * An IPv4 or IPv6 datagram follows the pseudo-header; dli_family indicates
1025  * which of those it is.
1026  */
1027 #define DLT_IPNET		226
1028 
1029 /*
1030  * CAN (Controller Area Network) frames, with a pseudo-header as supplied
1031  * by Linux SocketCAN, and with multi-byte numerical fields in that header
1032  * in big-endian byte order.
1033  *
1034  * See Documentation/networking/can.txt in the Linux source.
1035  *
1036  * Requested by Felix Obenhuber <felix@obenhuber.de>.
1037  */
1038 #define DLT_CAN_SOCKETCAN	227
1039 
1040 /*
1041  * Raw IPv4/IPv6; different from DLT_RAW in that the DLT_ value specifies
1042  * whether it's v4 or v6.  Requested by Darren Reed <Darren.Reed@Sun.COM>.
1043  */
1044 #define DLT_IPV4		228
1045 #define DLT_IPV6		229
1046 
1047 /*
1048  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
1049  * nothing), and with no FCS at the end of the frame; requested by
1050  * Jon Smirl <jonsmirl@gmail.com>.
1051  */
1052 #define DLT_IEEE802_15_4_NOFCS	230
1053 
1054 /*
1055  * Raw D-Bus:
1056  *
1057  *	http://www.freedesktop.org/wiki/Software/dbus
1058  *
1059  * messages:
1060  *
1061  *	http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-messages
1062  *
1063  * starting with the endianness flag, followed by the message type, etc.,
1064  * but without the authentication handshake before the message sequence:
1065  *
1066  *	http://dbus.freedesktop.org/doc/dbus-specification.html#auth-protocol
1067  *
1068  * Requested by Martin Vidner <martin@vidner.net>.
1069  */
1070 #define DLT_DBUS		231
1071 
1072 /*
1073  * Juniper-private data link type, as per request from
1074  * Hannes Gredler <hannes@juniper.net>.
1075  */
1076 #define DLT_JUNIPER_VS			232
1077 #define DLT_JUNIPER_SRX_E2E		233
1078 #define DLT_JUNIPER_FIBRECHANNEL	234
1079 
1080 /*
1081  * DVB-CI (DVB Common Interface for communication between a PC Card
1082  * module and a DVB receiver).  See
1083  *
1084  *	http://www.kaiser.cx/pcap-dvbci.html
1085  *
1086  * for the specification.
1087  *
1088  * Requested by Martin Kaiser <martin@kaiser.cx>.
1089  */
1090 #define DLT_DVB_CI		235
1091 
1092 /*
1093  * Variant of 3GPP TS 27.010 multiplexing protocol (similar to, but
1094  * *not* the same as, 27.010).  Requested by Hans-Christoph Schemmel
1095  * <hans-christoph.schemmel@cinterion.com>.
1096  */
1097 #define DLT_MUX27010		236
1098 
1099 /*
1100  * STANAG 5066 D_PDUs.  Requested by M. Baris Demiray
1101  * <barisdemiray@gmail.com>.
1102  */
1103 #define DLT_STANAG_5066_D_PDU	237
1104 
1105 /*
1106  * Juniper-private data link type, as per request from
1107  * Hannes Gredler <hannes@juniper.net>.
1108  */
1109 #define DLT_JUNIPER_ATM_CEMIC	238
1110 
1111 /*
1112  * NetFilter LOG messages
1113  * (payload of netlink NFNL_SUBSYS_ULOG/NFULNL_MSG_PACKET packets)
1114  *
1115  * Requested by Jakub Zawadzki <darkjames-ws@darkjames.pl>
1116  */
1117 #define DLT_NFLOG		239
1118 
1119 /*
1120  * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type
1121  * for Ethernet packets with a 4-byte pseudo-header and always
1122  * with the payload including the FCS, as supplied by their
1123  * netANALYZER hardware and software.
1124  *
1125  * Requested by Holger P. Frommer <HPfrommer@hilscher.com>
1126  */
1127 #define DLT_NETANALYZER		240
1128 
1129 /*
1130  * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type
1131  * for Ethernet packets with a 4-byte pseudo-header and FCS and
1132  * with the Ethernet header preceded by 7 bytes of preamble and
1133  * 1 byte of SFD, as supplied by their netANALYZER hardware and
1134  * software.
1135  *
1136  * Requested by Holger P. Frommer <HPfrommer@hilscher.com>
1137  */
1138 #define DLT_NETANALYZER_TRANSPARENT	241
1139 
1140 /*
1141  * IP-over-InfiniBand, as specified by RFC 4391.
1142  *
1143  * Requested by Petr Sumbera <petr.sumbera@oracle.com>.
1144  */
1145 #define DLT_IPOIB		242
1146 
1147 /*
1148  * MPEG-2 transport stream (ISO 13818-1/ITU-T H.222.0).
1149  *
1150  * Requested by Guy Martin <gmsoft@tuxicoman.be>.
1151  */
1152 #define DLT_MPEG_2_TS		243
1153 
1154 /*
1155  * ng4T GmbH's UMTS Iub/Iur-over-ATM and Iub/Iur-over-IP format as
1156  * used by their ng40 protocol tester.
1157  *
1158  * Requested by Jens Grimmer <jens.grimmer@ng4t.com>.
1159  */
1160 #define DLT_NG40		244
1161 
1162 /*
1163  * Pseudo-header giving adapter number and flags, followed by an NFC
1164  * (Near-Field Communications) Logical Link Control Protocol (LLCP) PDU,
1165  * as specified by NFC Forum Logical Link Control Protocol Technical
1166  * Specification LLCP 1.1.
1167  *
1168  * Requested by Mike Wakerly <mikey@google.com>.
1169  */
1170 #define DLT_NFC_LLCP		245
1171 
1172 /*
1173  * 246 is used as LINKTYPE_PFSYNC; do not use it for any other purpose.
1174  *
1175  * DLT_PFSYNC has different values on different platforms, and all of
1176  * them collide with something used elsewhere.  On platforms that
1177  * don't already define it, define it as 246.
1178  */
1179 #if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__) && !defined(__APPLE__)
1180 #define DLT_PFSYNC		246
1181 #endif
1182 
1183 /*
1184  * Raw InfiniBand packets, starting with the Local Routing Header.
1185  *
1186  * Requested by Oren Kladnitsky <orenk@mellanox.com>.
1187  */
1188 #define DLT_INFINIBAND		247
1189 
1190 /*
1191  * SCTP, with no lower-level protocols (i.e., no IPv4 or IPv6).
1192  *
1193  * Requested by Michael Tuexen <Michael.Tuexen@lurchi.franken.de>.
1194  */
1195 #define DLT_SCTP		248
1196 
1197 /*
1198  * USB packets, beginning with a USBPcap header.
1199  *
1200  * Requested by Tomasz Mon <desowin@gmail.com>
1201  */
1202 #define DLT_USBPCAP		249
1203 
1204 /*
1205  * Schweitzer Engineering Laboratories "RTAC" product serial-line
1206  * packets.
1207  *
1208  * Requested by Chris Bontje <chris_bontje@selinc.com>.
1209  */
1210 #define DLT_RTAC_SERIAL		250
1211 
1212 /*
1213  * Bluetooth Low Energy air interface link-layer packets.
1214  *
1215  * Requested by Mike Kershaw <dragorn@kismetwireless.net>.
1216  */
1217 #define DLT_BLUETOOTH_LE_LL	251
1218 
1219 /*
1220  * DLT type for upper-protocol layer PDU saves from wireshark.
1221  *
1222  * the actual contents are determined by two TAGs stored with each
1223  * packet:
1224  *   EXP_PDU_TAG_LINKTYPE          the link type (LINKTYPE_ value) of the
1225  *				   original packet.
1226  *
1227  *   EXP_PDU_TAG_PROTO_NAME        the name of the wireshark dissector
1228  * 				   that can make sense of the data stored.
1229  */
1230 #define DLT_WIRESHARK_UPPER_PDU	252
1231 
1232 /*
1233  * DLT type for the netlink protocol (nlmon devices).
1234  */
1235 #define DLT_NETLINK		253
1236 
1237 /*
1238  * Bluetooth Linux Monitor headers for the BlueZ stack.
1239  */
1240 #define DLT_BLUETOOTH_LINUX_MONITOR	254
1241 
1242 /*
1243  * Bluetooth Basic Rate/Enhanced Data Rate baseband packets, as
1244  * captured by Ubertooth.
1245  */
1246 #define DLT_BLUETOOTH_BREDR_BB	255
1247 
1248 /*
1249  * Bluetooth Low Energy link layer packets, as captured by Ubertooth.
1250  */
1251 #define DLT_BLUETOOTH_LE_LL_WITH_PHDR	256
1252 
1253 /*
1254  * PROFIBUS data link layer.
1255  */
1256 #define DLT_PROFIBUS_DL		257
1257 
1258 /*
1259  * Apple's DLT_PKTAP headers.
1260  *
1261  * Sadly, the folks at Apple either had no clue that the DLT_USERn values
1262  * are for internal use within an organization and partners only, and
1263  * didn't know that the right way to get a link-layer header type is to
1264  * ask tcpdump.org for one, or knew and didn't care, so they just
1265  * used DLT_USER2, which causes problems for everything except for
1266  * their version of tcpdump.
1267  *
1268  * So I'll just give them one; hopefully this will show up in a
1269  * libpcap release in time for them to get this into 10.10 Big Sur
1270  * or whatever Mavericks' successor is called.  LINKTYPE_PKTAP
1271  * will be 258 *even on macOS*; that is *intentional*, so that
1272  * PKTAP files look the same on *all* OSes (different OSes can have
1273  * different numerical values for a given DLT_, but *MUST NOT* have
1274  * different values for what goes in a file, as files can be moved
1275  * between OSes!).
1276  *
1277  * When capturing, on a system with a Darwin-based OS, on a device
1278  * that returns 149 (DLT_USER2 and Apple's DLT_PKTAP) with this
1279  * version of libpcap, the DLT_ value for the pcap_t  will be DLT_PKTAP,
1280  * and that will continue to be DLT_USER2 on Darwin-based OSes. That way,
1281  * binary compatibility with Mavericks is preserved for programs using
1282  * this version of libpcap.  This does mean that if you were using
1283  * DLT_USER2 for some capture device on macOS, you can't do so with
1284  * this version of libpcap, just as you can't with Apple's libpcap -
1285  * on macOS, they define DLT_PKTAP to be DLT_USER2, so programs won't
1286  * be able to distinguish between PKTAP and whatever you were using
1287  * DLT_USER2 for.
1288  *
1289  * If the program saves the capture to a file using this version of
1290  * libpcap's pcap_dump code, the LINKTYPE_ value in the file will be
1291  * LINKTYPE_PKTAP, which will be 258, even on Darwin-based OSes.
1292  * That way, the file will *not* be a DLT_USER2 file.  That means
1293  * that the latest version of tcpdump, when built with this version
1294  * of libpcap, and sufficiently recent versions of Wireshark will
1295  * be able to read those files and interpret them correctly; however,
1296  * Apple's version of tcpdump in OS X 10.9 won't be able to handle
1297  * them.  (Hopefully, Apple will pick up this version of libpcap,
1298  * and the corresponding version of tcpdump, so that tcpdump will
1299  * be able to handle the old LINKTYPE_USER2 captures *and* the new
1300  * LINKTYPE_PKTAP captures.)
1301  */
1302 #ifdef __APPLE__
1303 #define DLT_PKTAP	DLT_USER2
1304 #else
1305 #define DLT_PKTAP	258
1306 #endif
1307 
1308 /*
1309  * Ethernet packets preceded by a header giving the last 6 octets
1310  * of the preamble specified by 802.3-2012 Clause 65, section
1311  * 65.1.3.2 "Transmit".
1312  */
1313 #define DLT_EPON	259
1314 
1315 /*
1316  * IPMI trace packets, as specified by Table 3-20 "Trace Data Block Format"
1317  * in the PICMG HPM.2 specification.
1318  */
1319 #define DLT_IPMI_HPM_2	260
1320 
1321 /*
1322  * per  Joshua Wright <jwright@hasborg.com>, formats for Zwave captures.
1323  */
1324 #define DLT_ZWAVE_R1_R2  261
1325 #define DLT_ZWAVE_R3     262
1326 
1327 /*
1328  * per Steve Karg <skarg@users.sourceforge.net>, formats for Wattstopper
1329  * Digital Lighting Management room bus serial protocol captures.
1330  */
1331 #define DLT_WATTSTOPPER_DLM     263
1332 
1333 /*
1334  * ISO 14443 contactless smart card messages.
1335  */
1336 #define DLT_ISO_14443	264
1337 
1338 /*
1339  * Radio data system (RDS) groups.  IEC 62106.
1340  * Per Jonathan Brucker <jonathan.brucke@gmail.com>.
1341  */
1342 #define DLT_RDS		265
1343 
1344 /*
1345  * USB packets, beginning with a Darwin (macOS, etc.) header.
1346  */
1347 #define DLT_USB_DARWIN	266
1348 
1349 /*
1350  * OpenBSD DLT_OPENFLOW.
1351  */
1352 #define DLT_OPENFLOW	267
1353 
1354 /*
1355  * SDLC frames containing SNA PDUs.
1356  */
1357 #define DLT_SDLC	268
1358 
1359 /*
1360  * per "Selvig, Bjorn" <b.selvig@ti.com> used for
1361  * TI protocol sniffer.
1362  */
1363 #define DLT_TI_LLN_SNIFFER	269
1364 
1365 /*
1366  * per: Erik de Jong <erikdejong at gmail.com> for
1367  *   https://github.com/eriknl/LoRaTap/releases/tag/v0.1
1368  */
1369 #define DLT_LORATAP             270
1370 
1371 /*
1372  * per: Stefanha at gmail.com for
1373  *   http://lists.sandelman.ca/pipermail/tcpdump-workers/2017-May/000772.html
1374  * and: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/vsockmon.h
1375  * for: http://qemu-project.org/Features/VirtioVsock
1376  */
1377 #define DLT_VSOCK               271
1378 
1379 /*
1380  * Nordic Semiconductor Bluetooth LE sniffer.
1381  */
1382 #define DLT_NORDIC_BLE		272
1383 
1384 /*
1385  * Excentis DOCSIS 3.1 RF sniffer (XRA-31)
1386  *   per: bruno.verstuyft at excentis.com
1387  *        http://www.xra31.com/xra-header
1388  */
1389 #define DLT_DOCSIS31_XRA31	273
1390 
1391 /*
1392  * mPackets, as specified by IEEE 802.3br Figure 99-4, starting
1393  * with the preamble and always ending with a CRC field.
1394  */
1395 #define DLT_ETHERNET_MPACKET	274
1396 
1397 /*
1398  * DisplayPort AUX channel monitoring data as specified by VESA
1399  * DisplayPort(DP) Standard preceded by a pseudo-header.
1400  *    per dirk.eibach at gdsys.cc
1401  */
1402 #define DLT_DISPLAYPORT_AUX	275
1403 
1404 /*
1405  * Linux cooked sockets v2.
1406  */
1407 #define DLT_LINUX_SLL2	276
1408 
1409 /*
1410  * In case the code that includes this file (directly or indirectly)
1411  * has also included OS files that happen to define DLT_MATCHING_MAX,
1412  * with a different value (perhaps because that OS hasn't picked up
1413  * the latest version of our DLT definitions), we undefine the
1414  * previous value of DLT_MATCHING_MAX.
1415  */
1416 #ifdef DLT_MATCHING_MAX
1417 #undef DLT_MATCHING_MAX
1418 #endif
1419 #define DLT_MATCHING_MAX	276	/* highest value in the "matching" range */
1420 
1421 /*
1422  * DLT and savefile link type values are split into a class and
1423  * a member of that class.  A class value of 0 indicates a regular
1424  * DLT_/LINKTYPE_ value.
1425  */
1426 #define DLT_CLASS(x)		((x) & 0x03ff0000)
1427 
1428 /*
1429  * NetBSD-specific generic "raw" link type.  The class value indicates
1430  * that this is the generic raw type, and the lower 16 bits are the
1431  * address family we're dealing with.  Those values are NetBSD-specific;
1432  * do not assume that they correspond to AF_ values for your operating
1433  * system.
1434  */
1435 #define	DLT_CLASS_NETBSD_RAWAF	0x02240000
1436 #define	DLT_NETBSD_RAWAF(af)	(DLT_CLASS_NETBSD_RAWAF | (af))
1437 #define	DLT_NETBSD_RAWAF_AF(x)	((x) & 0x0000ffff)
1438 #define	DLT_IS_NETBSD_RAWAF(x)	(DLT_CLASS(x) == DLT_CLASS_NETBSD_RAWAF)
1439 
1440 #endif /* !_NET_DLT_H_ */
1441