xref: /netbsd-src/external/bsd/libpcap/dist/pcap-common.c (revision ccd9df534e375a4366c5b55f23782053c7a98d82)
1 /*	$NetBSD: pcap-common.c,v 1.8 2023/08/17 15:18:12 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1993, 1994, 1995, 1996, 1997
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that: (1) source code distributions
9  * retain the above copyright notice and this paragraph in its entirety, (2)
10  * distributions including binary code include the above copyright notice and
11  * this paragraph in its entirety in the documentation or other materials
12  * provided with the distribution, and (3) all advertising materials mentioning
13  * features or use of this software display the following acknowledgement:
14  * ``This product includes software developed by the University of California,
15  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16  * the University nor the names of its contributors may be used to endorse
17  * or promote products derived from this software without specific prior
18  * written permission.
19  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22  *
23  * pcap-common.c - common code for pcap and pcapng files
24  */
25 
26 #include <sys/cdefs.h>
27 __RCSID("$NetBSD: pcap-common.c,v 1.8 2023/08/17 15:18:12 christos Exp $");
28 
29 #ifdef HAVE_CONFIG_H
30 #include <config.h>
31 #endif
32 
33 #include <pcap-types.h>
34 
35 #include "pcap-int.h"
36 
37 #include "pcap-common.h"
38 
39 /*
40  * We don't write DLT_* values to capture files, because they're not the
41  * same on all platforms.
42  *
43  * Unfortunately, the various flavors of BSD have not always used the same
44  * numerical values for the same data types, and various patches to
45  * libpcap for non-BSD OSes have added their own DLT_* codes for link
46  * layer encapsulation types seen on those OSes, and those codes have had,
47  * in some cases, values that were also used, on other platforms, for other
48  * link layer encapsulation types.
49  *
50  * This means that capture files of a type whose numerical DLT_* code
51  * means different things on different BSDs, or with different versions
52  * of libpcap, can't always be read on systems other than those like
53  * the one running on the machine on which the capture was made.
54  *
55  * Instead, we define here a set of LINKTYPE_* codes, and map DLT_* codes
56  * to LINKTYPE_* codes when writing a savefile header, and map LINKTYPE_*
57  * codes to DLT_* codes when reading a savefile header.
58  *
59  * For those DLT_* codes that have, as far as we know, the same values on
60  * all platforms (DLT_NULL through DLT_FDDI), we define LINKTYPE_xxx as
61  * DLT_xxx; that way, captures of those types can still be read by
62  * versions of libpcap that map LINKTYPE_* values to DLT_* values, and
63  * captures of those types written by versions of libpcap that map DLT_
64  * values to LINKTYPE_ values can still be read by older versions
65  * of libpcap.
66  *
67  * The other LINKTYPE_* codes are given values starting at 100, in the
68  * hopes that no DLT_* code will be given one of those values.
69  *
70  * In order to ensure that a given LINKTYPE_* code's value will refer to
71  * the same encapsulation type on all platforms, you should not allocate
72  * a new LINKTYPE_* value without consulting
73  * "tcpdump-workers@lists.tcpdump.org".  The tcpdump developers will
74  * allocate a value for you, and will not subsequently allocate it to
75  * anybody else; that value will be added to the "pcap.h" in the
76  * tcpdump.org Git repository, so that a future libpcap release will
77  * include it.
78  *
79  * You should, if possible, also contribute patches to libpcap and tcpdump
80  * to handle the new encapsulation type, so that they can also be checked
81  * into the tcpdump.org Git repository and so that they will appear in
82  * future libpcap and tcpdump releases.
83  *
84  * Do *NOT* assume that any values after the largest value in this file
85  * are available; you might not have the most up-to-date version of this
86  * file, and new values after that one might have been assigned.  Also,
87  * do *NOT* use any values below 100 - those might already have been
88  * taken by one (or more!) organizations.
89  *
90  * Any platform that defines additional DLT_* codes should:
91  *
92  *	request a LINKTYPE_* code and value from tcpdump.org,
93  *	as per the above;
94  *
95  *	add, in their version of libpcap, an entry to map
96  *	those DLT_* codes to the corresponding LINKTYPE_*
97  *	code;
98  *
99  *	redefine, in their "net/bpf.h", any DLT_* values
100  *	that collide with the values used by their additional
101  *	DLT_* codes, to remove those collisions (but without
102  *	making them collide with any of the LINKTYPE_*
103  *	values equal to 50 or above; they should also avoid
104  *	defining DLT_* values that collide with those
105  *	LINKTYPE_* values, either).
106  */
107 #define LINKTYPE_NULL		DLT_NULL
108 #define LINKTYPE_ETHERNET	DLT_EN10MB	/* also for 100Mb and up */
109 #define LINKTYPE_EXP_ETHERNET	DLT_EN3MB	/* 3Mb experimental Ethernet */
110 #define LINKTYPE_AX25		DLT_AX25
111 #define LINKTYPE_PRONET		DLT_PRONET
112 #define LINKTYPE_CHAOS		DLT_CHAOS
113 #define LINKTYPE_IEEE802_5	DLT_IEEE802	/* DLT_IEEE802 is used for 802.5 Token Ring */
114 #define LINKTYPE_ARCNET_BSD	DLT_ARCNET	/* BSD-style headers */
115 #define LINKTYPE_SLIP		DLT_SLIP
116 #define LINKTYPE_PPP		DLT_PPP
117 #define LINKTYPE_FDDI		DLT_FDDI
118 
119 /*
120  * LINKTYPE_PPP is for use when there might, or might not, be an RFC 1662
121  * PPP in HDLC-like framing header (with 0xff 0x03 before the PPP protocol
122  * field) at the beginning of the packet.
123  *
124  * This is for use when there is always such a header; the address field
125  * might be 0xff, for regular PPP, or it might be an address field for Cisco
126  * point-to-point with HDLC framing as per section 4.3.1 of RFC 1547 ("Cisco
127  * HDLC").  This is, for example, what you get with NetBSD's DLT_PPP_SERIAL.
128  *
129  * We give it the same value as NetBSD's DLT_PPP_SERIAL, in the hopes that
130  * nobody else will choose a DLT_ value of 50, and so that DLT_PPP_SERIAL
131  * captures will be written out with a link type that NetBSD's tcpdump
132  * can read.
133  */
134 #define LINKTYPE_PPP_HDLC	50		/* PPP in HDLC-like framing */
135 
136 #define LINKTYPE_PPP_ETHER	51		/* NetBSD PPP-over-Ethernet */
137 
138 #define LINKTYPE_SYMANTEC_FIREWALL 99		/* Symantec Enterprise Firewall */
139 
140 /*
141  * These correspond to DLT_s that have different values on different
142  * platforms; we map between these values in capture files and
143  * the DLT_ values as returned by pcap_datalink() and passed to
144  * pcap_open_dead().
145  */
146 #define LINKTYPE_ATM_RFC1483	100		/* LLC/SNAP-encapsulated ATM */
147 #define LINKTYPE_RAW		101		/* raw IP */
148 #define LINKTYPE_SLIP_BSDOS	102		/* BSD/OS SLIP BPF header */
149 #define LINKTYPE_PPP_BSDOS	103		/* BSD/OS PPP BPF header */
150 
151 /*
152  * Values starting with 104 are used for newly-assigned link-layer
153  * header type values; for those link-layer header types, the DLT_
154  * value returned by pcap_datalink() and passed to pcap_open_dead(),
155  * and the LINKTYPE_ value that appears in capture files, are the
156  * same.
157  *
158  * LINKTYPE_MATCHING_MIN is the lowest such value; LINKTYPE_MATCHING_MAX
159  * is the highest such value.
160  */
161 #define LINKTYPE_MATCHING_MIN	104		/* lowest value in the "matching" range */
162 
163 #define LINKTYPE_C_HDLC		104		/* Cisco HDLC */
164 #define LINKTYPE_IEEE802_11	105		/* IEEE 802.11 (wireless) */
165 #define LINKTYPE_ATM_CLIP	106		/* Linux Classical IP over ATM */
166 #define LINKTYPE_FRELAY		107		/* Frame Relay */
167 #define LINKTYPE_LOOP		108		/* OpenBSD loopback */
168 #define LINKTYPE_ENC		109		/* OpenBSD IPSEC enc */
169 
170 /*
171  * These two types are reserved for future use.
172  */
173 #define LINKTYPE_LANE8023	110		/* ATM LANE + 802.3 */
174 #define LINKTYPE_HIPPI		111		/* NetBSD HIPPI */
175 
176 /*
177  * Used for NetBSD DLT_HDLC; from looking at the one driver in NetBSD
178  * that uses it, it's Cisco HDLC, so it's the same as DLT_C_HDLC/
179  * LINKTYPE_C_HDLC, but we define a separate value to avoid some
180  * compatibility issues with programs on NetBSD.
181  *
182  * All code should treat LINKTYPE_NETBSD_HDLC and LINKTYPE_C_HDLC the same.
183  */
184 #define LINKTYPE_NETBSD_HDLC	112		/* NetBSD HDLC framing */
185 
186 #define LINKTYPE_LINUX_SLL	113		/* Linux cooked socket capture */
187 #define LINKTYPE_LTALK		114		/* Apple LocalTalk hardware */
188 #define LINKTYPE_ECONET		115		/* Acorn Econet */
189 
190 /*
191  * Reserved for use with OpenBSD ipfilter.
192  */
193 #define LINKTYPE_IPFILTER	116
194 
195 #define LINKTYPE_PFLOG		117		/* OpenBSD DLT_PFLOG */
196 #define LINKTYPE_CISCO_IOS	118		/* For Cisco-internal use */
197 #define LINKTYPE_IEEE802_11_PRISM 119		/* 802.11 plus Prism II monitor mode radio metadata header */
198 #define LINKTYPE_IEEE802_11_AIRONET 120		/* 802.11 plus FreeBSD Aironet driver radio metadata header */
199 
200 /*
201  * Reserved for Siemens HiPath HDLC.
202  */
203 #define LINKTYPE_HHDLC		121
204 
205 #define LINKTYPE_IP_OVER_FC	122		/* RFC 2625 IP-over-Fibre Channel */
206 #define LINKTYPE_SUNATM		123		/* Solaris+SunATM */
207 
208 /*
209  * Reserved as per request from Kent Dahlgren <kent@praesum.com>
210  * for private use.
211  */
212 #define LINKTYPE_RIO		124		/* RapidIO */
213 #define LINKTYPE_PCI_EXP	125		/* PCI Express */
214 #define LINKTYPE_AURORA		126		/* Xilinx Aurora link layer */
215 
216 #define LINKTYPE_IEEE802_11_RADIOTAP 127	/* 802.11 plus radiotap radio metadata header */
217 
218 /*
219  * Reserved for the TZSP encapsulation, as per request from
220  * Chris Waters <chris.waters@networkchemistry.com>
221  * TZSP is a generic encapsulation for any other link type,
222  * which includes a means to include meta-information
223  * with the packet, e.g. signal strength and channel
224  * for 802.11 packets.
225  */
226 #define LINKTYPE_TZSP		128		/* Tazmen Sniffer Protocol */
227 
228 #define LINKTYPE_ARCNET_LINUX	129		/* Linux-style headers */
229 
230 /*
231  * Juniper-private data link types, as per request from
232  * Hannes Gredler <hannes@juniper.net>.  The corresponding
233  * DLT_s are used for passing on chassis-internal
234  * metainformation such as QOS profiles, etc..
235  */
236 #define LINKTYPE_JUNIPER_MLPPP  130
237 #define LINKTYPE_JUNIPER_MLFR   131
238 #define LINKTYPE_JUNIPER_ES     132
239 #define LINKTYPE_JUNIPER_GGSN   133
240 #define LINKTYPE_JUNIPER_MFR    134
241 #define LINKTYPE_JUNIPER_ATM2   135
242 #define LINKTYPE_JUNIPER_SERVICES 136
243 #define LINKTYPE_JUNIPER_ATM1   137
244 
245 #define LINKTYPE_APPLE_IP_OVER_IEEE1394 138	/* Apple IP-over-IEEE 1394 cooked header */
246 
247 #define LINKTYPE_MTP2_WITH_PHDR	139
248 #define LINKTYPE_MTP2		140
249 #define LINKTYPE_MTP3		141
250 #define LINKTYPE_SCCP		142
251 
252 #define LINKTYPE_DOCSIS		143		/* DOCSIS MAC frames */
253 
254 #define LINKTYPE_LINUX_IRDA	144		/* Linux-IrDA */
255 
256 /*
257  * Reserved for IBM SP switch and IBM Next Federation switch.
258  */
259 #define LINKTYPE_IBM_SP		145
260 #define LINKTYPE_IBM_SN		146
261 
262 /*
263  * Reserved for private use.  If you have some link-layer header type
264  * that you want to use within your organization, with the capture files
265  * using that link-layer header type not ever be sent outside your
266  * organization, you can use these values.
267  *
268  * No libpcap release will use these for any purpose, nor will any
269  * tcpdump release use them, either.
270  *
271  * Do *NOT* use these in capture files that you expect anybody not using
272  * your private versions of capture-file-reading tools to read; in
273  * particular, do *NOT* use them in products, otherwise you may find that
274  * people won't be able to use tcpdump, or snort, or Ethereal, or... to
275  * read capture files from your firewall/intrusion detection/traffic
276  * monitoring/etc. appliance, or whatever product uses that LINKTYPE_ value,
277  * and you may also find that the developers of those applications will
278  * not accept patches to let them read those files.
279  *
280  * Also, do not use them if somebody might send you a capture using them
281  * for *their* private type and tools using them for *your* private type
282  * would have to read them.
283  *
284  * Instead, in those cases, ask "tcpdump-workers@lists.tcpdump.org" for a
285  * new DLT_ and LINKTYPE_ value, as per the comment in pcap/bpf.h, and use
286  * the type you're given.
287  */
288 #define LINKTYPE_USER0		147
289 #define LINKTYPE_USER1		148
290 #define LINKTYPE_USER2		149
291 #define LINKTYPE_USER3		150
292 #define LINKTYPE_USER4		151
293 #define LINKTYPE_USER5		152
294 #define LINKTYPE_USER6		153
295 #define LINKTYPE_USER7		154
296 #define LINKTYPE_USER8		155
297 #define LINKTYPE_USER9		156
298 #define LINKTYPE_USER10		157
299 #define LINKTYPE_USER11		158
300 #define LINKTYPE_USER12		159
301 #define LINKTYPE_USER13		160
302 #define LINKTYPE_USER14		161
303 #define LINKTYPE_USER15		162
304 
305 /*
306  * For future use with 802.11 captures - defined by AbsoluteValue
307  * Systems to store a number of bits of link-layer information
308  * including radio information:
309  *
310  *	http://www.shaftnet.org/~pizza/software/capturefrm.txt
311  */
312 #define LINKTYPE_IEEE802_11_AVS	163	/* 802.11 plus AVS radio metadata header */
313 
314 /*
315  * Juniper-private data link type, as per request from
316  * Hannes Gredler <hannes@juniper.net>.  The corresponding
317  * DLT_s are used for passing on chassis-internal
318  * metainformation such as QOS profiles, etc..
319  */
320 #define LINKTYPE_JUNIPER_MONITOR 164
321 
322 /*
323  * BACnet MS/TP frames.
324  */
325 #define LINKTYPE_BACNET_MS_TP	165
326 
327 /*
328  * Another PPP variant as per request from Karsten Keil <kkeil@suse.de>.
329  *
330  * This is used in some OSes to allow a kernel socket filter to distinguish
331  * between incoming and outgoing packets, on a socket intended to
332  * supply pppd with outgoing packets so it can do dial-on-demand and
333  * hangup-on-lack-of-demand; incoming packets are filtered out so they
334  * don't cause pppd to hold the connection up (you don't want random
335  * input packets such as port scans, packets from old lost connections,
336  * etc. to force the connection to stay up).
337  *
338  * The first byte of the PPP header (0xff03) is modified to accommodate
339  * the direction - 0x00 = IN, 0x01 = OUT.
340  */
341 #define LINKTYPE_PPP_PPPD	166
342 
343 /*
344  * Juniper-private data link type, as per request from
345  * Hannes Gredler <hannes@juniper.net>.  The DLT_s are used
346  * for passing on chassis-internal metainformation such as
347  * QOS profiles, cookies, etc..
348  */
349 #define LINKTYPE_JUNIPER_PPPOE     167
350 #define LINKTYPE_JUNIPER_PPPOE_ATM 168
351 
352 #define LINKTYPE_GPRS_LLC	169		/* GPRS LLC */
353 #define LINKTYPE_GPF_T		170		/* GPF-T (ITU-T G.7041/Y.1303) */
354 #define LINKTYPE_GPF_F		171		/* GPF-F (ITU-T G.7041/Y.1303) */
355 
356 /*
357  * Requested by Oolan Zimmer <oz@gcom.com> for use in Gcom's T1/E1 line
358  * monitoring equipment.
359  */
360 #define LINKTYPE_GCOM_T1E1	172
361 #define LINKTYPE_GCOM_SERIAL	173
362 
363 /*
364  * Juniper-private data link type, as per request from
365  * Hannes Gredler <hannes@juniper.net>.  The DLT_ is used
366  * for internal communication to Physical Interface Cards (PIC)
367  */
368 #define LINKTYPE_JUNIPER_PIC_PEER    174
369 
370 /*
371  * Link types requested by Gregor Maier <gregor@endace.com> of Endace
372  * Measurement Systems.  They add an ERF header (see
373  * https://www.endace.com/support/EndaceRecordFormat.pdf) in front of
374  * the link-layer header.
375  */
376 #define LINKTYPE_ERF_ETH	175	/* Ethernet */
377 #define LINKTYPE_ERF_POS	176	/* Packet-over-SONET */
378 
379 /*
380  * Requested by Daniele Orlandi <daniele@orlandi.com> for raw LAPD
381  * for vISDN (http://www.orlandi.com/visdn/).  Its link-layer header
382  * includes additional information before the LAPD header, so it's
383  * not necessarily a generic LAPD header.
384  */
385 #define LINKTYPE_LINUX_LAPD	177
386 
387 /*
388  * Juniper-private data link type, as per request from
389  * Hannes Gredler <hannes@juniper.net>.
390  * The Link Types are used for prepending meta-information
391  * like interface index, interface name
392  * before standard Ethernet, PPP, Frelay & C-HDLC Frames
393  */
394 #define LINKTYPE_JUNIPER_ETHER  178
395 #define LINKTYPE_JUNIPER_PPP    179
396 #define LINKTYPE_JUNIPER_FRELAY 180
397 #define LINKTYPE_JUNIPER_CHDLC  181
398 
399 /*
400  * Multi Link Frame Relay (FRF.16)
401  */
402 #define LINKTYPE_MFR            182
403 
404 /*
405  * Juniper-private data link type, as per request from
406  * Hannes Gredler <hannes@juniper.net>.
407  * The DLT_ is used for internal communication with a
408  * voice Adapter Card (PIC)
409  */
410 #define LINKTYPE_JUNIPER_VP     183
411 
412 /*
413  * Arinc 429 frames.
414  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
415  * Every frame contains a 32bit A429 label.
416  * More documentation on Arinc 429 can be found at
417  * https://web.archive.org/web/20040616233302/https://www.condoreng.com/support/downloads/tutorials/ARINCTutorial.pdf
418  */
419 #define LINKTYPE_A429           184
420 
421 /*
422  * Arinc 653 Interpartition Communication messages.
423  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
424  * Please refer to the A653-1 standard for more information.
425  */
426 #define LINKTYPE_A653_ICM       185
427 
428 /*
429  * This used to be "USB packets, beginning with a USB setup header;
430  * requested by Paolo Abeni <paolo.abeni@email.it>."
431  *
432  * However, that header didn't work all that well - it left out some
433  * useful information - and was abandoned in favor of the DLT_USB_LINUX
434  * header.
435  *
436  * This is now used by FreeBSD for its BPF taps for USB; that has its
437  * own headers.  So it is written, so it is done.
438  */
439 #define LINKTYPE_USB_FREEBSD	186
440 
441 /*
442  * Bluetooth HCI UART transport layer (part H:4); requested by
443  * Paolo Abeni.
444  */
445 #define LINKTYPE_BLUETOOTH_HCI_H4	187
446 
447 /*
448  * IEEE 802.16 MAC Common Part Sublayer; requested by Maria Cruz
449  * <cruz_petagay@bah.com>.
450  */
451 #define LINKTYPE_IEEE802_16_MAC_CPS	188
452 
453 /*
454  * USB packets, beginning with a Linux USB header; requested by
455  * Paolo Abeni <paolo.abeni@email.it>.
456  */
457 #define LINKTYPE_USB_LINUX		189
458 
459 /*
460  * Controller Area Network (CAN) v. 2.0B packets.
461  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
462  * Used to dump CAN packets coming from a CAN Vector board.
463  * More documentation on the CAN v2.0B frames can be found at
464  * http://www.can-cia.org/downloads/?269
465  */
466 #define LINKTYPE_CAN20B         190
467 
468 /*
469  * IEEE 802.15.4, with address fields padded, as is done by Linux
470  * drivers; requested by Juergen Schimmer.
471  */
472 #define LINKTYPE_IEEE802_15_4_LINUX	191
473 
474 /*
475  * Per Packet Information encapsulated packets.
476  * LINKTYPE_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
477  */
478 #define LINKTYPE_PPI			192
479 
480 /*
481  * Header for 802.16 MAC Common Part Sublayer plus a radiotap radio header;
482  * requested by Charles Clancy.
483  */
484 #define LINKTYPE_IEEE802_16_MAC_CPS_RADIO	193
485 
486 /*
487  * Juniper-private data link type, as per request from
488  * Hannes Gredler <hannes@juniper.net>.
489  * The DLT_ is used for internal communication with a
490  * integrated service module (ISM).
491  */
492 #define LINKTYPE_JUNIPER_ISM    194
493 
494 /*
495  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
496  * nothing), and with the FCS at the end of the frame; requested by
497  * Mikko Saarnivala <mikko.saarnivala@sensinode.com>.
498  *
499  * This should only be used if the FCS is present at the end of the
500  * frame; if the frame has no FCS, DLT_IEEE802_15_4_NOFCS should be
501  * used.
502  */
503 #define LINKTYPE_IEEE802_15_4_WITHFCS	195
504 
505 /*
506  * Various link-layer types, with a pseudo-header, for SITA
507  * (https://www.sita.aero/); requested by Fulko Hew (fulko.hew@gmail.com).
508  */
509 #define LINKTYPE_SITA		196
510 
511 /*
512  * Various link-layer types, with a pseudo-header, for Endace DAG cards;
513  * encapsulates Endace ERF records.  Requested by Stephen Donnelly
514  * <stephen@endace.com>.
515  */
516 #define LINKTYPE_ERF		197
517 
518 /*
519  * Special header prepended to Ethernet packets when capturing from a
520  * u10 Networks board.  Requested by Phil Mulholland
521  * <phil@u10networks.com>.
522  */
523 #define LINKTYPE_RAIF1		198
524 
525 /*
526  * IPMB packet for IPMI, beginning with a 2-byte header, followed by
527  * the I2C slave address, followed by the netFn and LUN, etc..
528  * Requested by Chanthy Toeung <chanthy.toeung@ca.kontron.com>.
529  *
530  * XXX - its DLT_ value used to be called DLT_IPMB, back when we got the
531  * impression from the email thread requesting it that the packet
532  * had no extra 2-byte header.  We've renamed it; if anybody used
533  * DLT_IPMB and assumed no 2-byte header, this will cause the compile
534  * to fail, at which point we'll have to figure out what to do about
535  * the two header types using the same DLT_/LINKTYPE_ value.  If that
536  * doesn't happen, we'll assume nobody used it and that the redefinition
537  * is safe.
538  */
539 #define LINKTYPE_IPMB_KONTRON	199
540 
541 /*
542  * Juniper-private data link type, as per request from
543  * Hannes Gredler <hannes@juniper.net>.
544  * The DLT_ is used for capturing data on a secure tunnel interface.
545  */
546 #define LINKTYPE_JUNIPER_ST     200
547 
548 /*
549  * Bluetooth HCI UART transport layer (part H:4), with pseudo-header
550  * that includes direction information; requested by Paolo Abeni.
551  */
552 #define LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR	201
553 
554 /*
555  * AX.25 packet with a 1-byte KISS header; see
556  *
557  *	http://www.ax25.net/kiss.htm
558  *
559  * as per Richard Stearn <richard@rns-stearn.demon.co.uk>.
560  */
561 #define LINKTYPE_AX25_KISS	202
562 
563 /*
564  * LAPD packets from an ISDN channel, starting with the address field,
565  * with no pseudo-header.
566  * Requested by Varuna De Silva <varunax@gmail.com>.
567  */
568 #define LINKTYPE_LAPD		203
569 
570 /*
571  * PPP, with a one-byte direction pseudo-header prepended - zero means
572  * "received by this host", non-zero (any non-zero value) means "sent by
573  * this host" - as per Will Barker <w.barker@zen.co.uk>.
574  */
575 #define LINKTYPE_PPP_WITH_DIR	204	/* Don't confuse with LINKTYPE_PPP_PPPD */
576 
577 /*
578  * Cisco HDLC, with a one-byte direction pseudo-header prepended - zero
579  * means "received by this host", non-zero (any non-zero value) means
580  * "sent by this host" - as per Will Barker <w.barker@zen.co.uk>.
581  */
582 #define LINKTYPE_C_HDLC_WITH_DIR 205	/* Cisco HDLC */
583 
584 /*
585  * Frame Relay, with a one-byte direction pseudo-header prepended - zero
586  * means "received by this host" (DCE -> DTE), non-zero (any non-zero
587  * value) means "sent by this host" (DTE -> DCE) - as per Will Barker
588  * <w.barker@zen.co.uk>.
589  */
590 #define LINKTYPE_FRELAY_WITH_DIR 206	/* Frame Relay */
591 
592 /*
593  * LAPB, with a one-byte direction pseudo-header prepended - zero means
594  * "received by this host" (DCE -> DTE), non-zero (any non-zero value)
595  * means "sent by this host" (DTE -> DCE)- as per Will Barker
596  * <w.barker@zen.co.uk>.
597  */
598 #define LINKTYPE_LAPB_WITH_DIR	207	/* LAPB */
599 
600 /*
601  * 208 is reserved for an as-yet-unspecified proprietary link-layer
602  * type, as requested by Will Barker.
603  */
604 
605 /*
606  * IPMB with a Linux-specific pseudo-header; as requested by Alexey Neyman
607  * <avn@pigeonpoint.com>.
608  */
609 #define LINKTYPE_IPMB_LINUX	209
610 
611 /*
612  * FlexRay automotive bus - http://www.flexray.com/ - as requested
613  * by Hannes Kaelber <hannes.kaelber@x2e.de>.
614  */
615 #define LINKTYPE_FLEXRAY	210
616 
617 /*
618  * Media Oriented Systems Transport (MOST) bus for multimedia
619  * transport - https://www.mostcooperation.com/ - as requested
620  * by Hannes Kaelber <hannes.kaelber@x2e.de>.
621  */
622 #define LINKTYPE_MOST		211
623 
624 /*
625  * Local Interconnect Network (LIN) bus for vehicle networks -
626  * http://www.lin-subbus.org/ - as requested by Hannes Kaelber
627  * <hannes.kaelber@x2e.de>.
628  */
629 #define LINKTYPE_LIN		212
630 
631 /*
632  * X2E-private data link type used for serial line capture,
633  * as requested by Hannes Kaelber <hannes.kaelber@x2e.de>.
634  */
635 #define LINKTYPE_X2E_SERIAL	213
636 
637 /*
638  * X2E-private data link type used for the Xoraya data logger
639  * family, as requested by Hannes Kaelber <hannes.kaelber@x2e.de>.
640  */
641 #define LINKTYPE_X2E_XORAYA	214
642 
643 /*
644  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
645  * nothing), but with the PHY-level data for non-ASK PHYs (4 octets
646  * of 0 as preamble, one octet of SFD, one octet of frame length+
647  * reserved bit, and then the MAC-layer data, starting with the
648  * frame control field).
649  *
650  * Requested by Max Filippov <jcmvbkbc@gmail.com>.
651  */
652 #define LINKTYPE_IEEE802_15_4_NONASK_PHY	215
653 
654 /*
655  * David Gibson <david@gibson.dropbear.id.au> requested this for
656  * captures from the Linux kernel /dev/input/eventN devices. This
657  * is used to communicate keystrokes and mouse movements from the
658  * Linux kernel to display systems, such as Xorg.
659  */
660 #define LINKTYPE_LINUX_EVDEV	216
661 
662 /*
663  * GSM Um and Abis interfaces, preceded by a "gsmtap" header.
664  *
665  * Requested by Harald Welte <laforge@gnumonks.org>.
666  */
667 #define LINKTYPE_GSMTAP_UM	217
668 #define LINKTYPE_GSMTAP_ABIS	218
669 
670 /*
671  * MPLS, with an MPLS label as the link-layer header.
672  * Requested by Michele Marchetto <michele@openbsd.org> on behalf
673  * of OpenBSD.
674  */
675 #define LINKTYPE_MPLS		219
676 
677 /*
678  * USB packets, beginning with a Linux USB header, with the USB header
679  * padded to 64 bytes; required for memory-mapped access.
680  */
681 #define LINKTYPE_USB_LINUX_MMAPPED		220
682 
683 /*
684  * DECT packets, with a pseudo-header; requested by
685  * Matthias Wenzel <tcpdump@mazzoo.de>.
686  */
687 #define LINKTYPE_DECT		221
688 
689 /*
690  * From: "Lidwa, Eric (GSFC-582.0)[SGT INC]" <eric.lidwa-1@nasa.gov>
691  * Date: Mon, 11 May 2009 11:18:30 -0500
692  *
693  * DLT_AOS. We need it for AOS Space Data Link Protocol.
694  *   I have already written dissectors for but need an OK from
695  *   legal before I can submit a patch.
696  *
697  */
698 #define LINKTYPE_AOS		222
699 
700 /*
701  * Wireless HART (Highway Addressable Remote Transducer)
702  * From the HART Communication Foundation
703  * IES/PAS 62591
704  *
705  * Requested by Sam Roberts <vieuxtech@gmail.com>.
706  */
707 #define LINKTYPE_WIHART		223
708 
709 /*
710  * Fibre Channel FC-2 frames, beginning with a Frame_Header.
711  * Requested by Kahou Lei <kahou82@gmail.com>.
712  */
713 #define LINKTYPE_FC_2		224
714 
715 /*
716  * Fibre Channel FC-2 frames, beginning with an encoding of the
717  * SOF, and ending with an encoding of the EOF.
718  *
719  * The encodings represent the frame delimiters as 4-byte sequences
720  * representing the corresponding ordered sets, with K28.5
721  * represented as 0xBC, and the D symbols as the corresponding
722  * byte values; for example, SOFi2, which is K28.5 - D21.5 - D1.2 - D21.2,
723  * is represented as 0xBC 0xB5 0x55 0x55.
724  *
725  * Requested by Kahou Lei <kahou82@gmail.com>.
726  */
727 #define LINKTYPE_FC_2_WITH_FRAME_DELIMS		225
728 
729 /*
730  * Solaris ipnet pseudo-header; requested by Darren Reed <Darren.Reed@Sun.COM>.
731  *
732  * The pseudo-header starts with a one-byte version number; for version 2,
733  * the pseudo-header is:
734  *
735  * struct dl_ipnetinfo {
736  *     uint8_t   dli_version;
737  *     uint8_t   dli_family;
738  *     uint16_t  dli_htype;
739  *     uint32_t  dli_pktlen;
740  *     uint32_t  dli_ifindex;
741  *     uint32_t  dli_grifindex;
742  *     uint32_t  dli_zsrc;
743  *     uint32_t  dli_zdst;
744  * };
745  *
746  * dli_version is 2 for the current version of the pseudo-header.
747  *
748  * dli_family is a Solaris address family value, so it's 2 for IPv4
749  * and 26 for IPv6.
750  *
751  * dli_htype is a "hook type" - 0 for incoming packets, 1 for outgoing
752  * packets, and 2 for packets arriving from another zone on the same
753  * machine.
754  *
755  * dli_pktlen is the length of the packet data following the pseudo-header
756  * (so the captured length minus dli_pktlen is the length of the
757  * pseudo-header, assuming the entire pseudo-header was captured).
758  *
759  * dli_ifindex is the interface index of the interface on which the
760  * packet arrived.
761  *
762  * dli_grifindex is the group interface index number (for IPMP interfaces).
763  *
764  * dli_zsrc is the zone identifier for the source of the packet.
765  *
766  * dli_zdst is the zone identifier for the destination of the packet.
767  *
768  * A zone number of 0 is the global zone; a zone number of 0xffffffff
769  * means that the packet arrived from another host on the network, not
770  * from another zone on the same machine.
771  *
772  * An IPv4 or IPv6 datagram follows the pseudo-header; dli_family indicates
773  * which of those it is.
774  */
775 #define LINKTYPE_IPNET		226
776 
777 /*
778  * CAN (Controller Area Network) frames, with a pseudo-header as supplied
779  * by Linux SocketCAN, and with multi-byte numerical fields in that header
780  * in big-endian byte order.
781  *
782  * See Documentation/networking/can.txt in the Linux source.
783  *
784  * Requested by Felix Obenhuber <felix@obenhuber.de>.
785  */
786 #define LINKTYPE_CAN_SOCKETCAN	227
787 
788 /*
789  * Raw IPv4/IPv6; different from DLT_RAW in that the DLT_ value specifies
790  * whether it's v4 or v6.  Requested by Darren Reed <Darren.Reed@Sun.COM>.
791  */
792 #define LINKTYPE_IPV4		228
793 #define LINKTYPE_IPV6		229
794 
795 /*
796  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
797  * nothing), and with no FCS at the end of the frame; requested by
798  * Jon Smirl <jonsmirl@gmail.com>.
799  */
800 #define LINKTYPE_IEEE802_15_4_NOFCS		230
801 
802 /*
803  * Raw D-Bus:
804  *
805  *	https://www.freedesktop.org/wiki/Software/dbus
806  *
807  * messages:
808  *
809  *	https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-messages
810  *
811  * starting with the endianness flag, followed by the message type, etc.,
812  * but without the authentication handshake before the message sequence:
813  *
814  *	https://dbus.freedesktop.org/doc/dbus-specification.html#auth-protocol
815  *
816  * Requested by Martin Vidner <martin@vidner.net>.
817  */
818 #define LINKTYPE_DBUS		231
819 
820 /*
821  * Juniper-private data link type, as per request from
822  * Hannes Gredler <hannes@juniper.net>.
823  */
824 #define LINKTYPE_JUNIPER_VS			232
825 #define LINKTYPE_JUNIPER_SRX_E2E		233
826 #define LINKTYPE_JUNIPER_FIBRECHANNEL		234
827 
828 /*
829  * DVB-CI (DVB Common Interface for communication between a PC Card
830  * module and a DVB receiver).  See
831  *
832  *	https://www.kaiser.cx/pcap-dvbci.html
833  *
834  * for the specification.
835  *
836  * Requested by Martin Kaiser <martin@kaiser.cx>.
837  */
838 #define LINKTYPE_DVB_CI		235
839 
840 /*
841  * Variant of 3GPP TS 27.010 multiplexing protocol.  Requested
842  * by Hans-Christoph Schemmel <hans-christoph.schemmel@cinterion.com>.
843  */
844 #define LINKTYPE_MUX27010	236
845 
846 /*
847  * STANAG 5066 D_PDUs.  Requested by M. Baris Demiray
848  * <barisdemiray@gmail.com>.
849  */
850 #define LINKTYPE_STANAG_5066_D_PDU		237
851 
852 /*
853  * Juniper-private data link type, as per request from
854  * Hannes Gredler <hannes@juniper.net>.
855  */
856 #define LINKTYPE_JUNIPER_ATM_CEMIC		238
857 
858 /*
859  * NetFilter LOG messages
860  * (payload of netlink NFNL_SUBSYS_ULOG/NFULNL_MSG_PACKET packets)
861  *
862  * Requested by Jakub Zawadzki <darkjames-ws@darkjames.pl>
863  */
864 #define LINKTYPE_NFLOG		239
865 
866 /*
867  * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type
868  * for Ethernet packets with a 4-byte pseudo-header and always
869  * with the payload including the FCS, as supplied by their
870  * netANALYZER hardware and software.
871  *
872  * Requested by Holger P. Frommer <HPfrommer@hilscher.com>
873  */
874 #define LINKTYPE_NETANALYZER	240
875 
876 /*
877  * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type
878  * for Ethernet packets with a 4-byte pseudo-header and FCS and
879  * 1 byte of SFD, as supplied by their netANALYZER hardware and
880  * software.
881  *
882  * Requested by Holger P. Frommer <HPfrommer@hilscher.com>
883  */
884 #define LINKTYPE_NETANALYZER_TRANSPARENT	241
885 
886 /*
887  * IP-over-InfiniBand, as specified by RFC 4391.
888  *
889  * Requested by Petr Sumbera <petr.sumbera@oracle.com>.
890  */
891 #define LINKTYPE_IPOIB		242
892 
893 /*
894  * MPEG-2 transport stream (ISO 13818-1/ITU-T H.222.0).
895  *
896  * Requested by Guy Martin <gmsoft@tuxicoman.be>.
897  */
898 #define LINKTYPE_MPEG_2_TS	243
899 
900 /*
901  * ng4T GmbH's UMTS Iub/Iur-over-ATM and Iub/Iur-over-IP format as
902  * used by their ng40 protocol tester.
903  *
904  * Requested by Jens Grimmer <jens.grimmer@ng4t.com>.
905  */
906 #define LINKTYPE_NG40		244
907 
908 /*
909  * Pseudo-header giving adapter number and flags, followed by an NFC
910  * (Near-Field Communications) Logical Link Control Protocol (LLCP) PDU,
911  * as specified by NFC Forum Logical Link Control Protocol Technical
912  * Specification LLCP 1.1.
913  *
914  * Requested by Mike Wakerly <mikey@google.com>.
915  */
916 #define LINKTYPE_NFC_LLCP	245
917 
918 /*
919  * pfsync output; DLT_PFSYNC is 18, which collides with DLT_CIP in
920  * SuSE 6.3, on OpenBSD, NetBSD, DragonFly BSD, and macOS, and
921  * is 121, which collides with DLT_HHDLC, in FreeBSD.  We pick a
922  * shiny new link-layer header type value that doesn't collide with
923  * anything, in the hopes that future pfsync savefiles, if any,
924  * won't require special hacks to distinguish from other savefiles.
925  *
926  */
927 #define LINKTYPE_PFSYNC		246
928 
929 /*
930  * Raw InfiniBand packets, starting with the Local Routing Header.
931  *
932  * Requested by Oren Kladnitsky <orenk@mellanox.com>.
933  */
934 #define LINKTYPE_INFINIBAND	247
935 
936 /*
937  * SCTP, with no lower-level protocols (i.e., no IPv4 or IPv6).
938  *
939  * Requested by Michael Tuexen <Michael.Tuexen@lurchi.franken.de>.
940  */
941 #define LINKTYPE_SCTP		248
942 
943 /*
944  * USB packets, beginning with a USBPcap header.
945  *
946  * Requested by Tomasz Mon <desowin@gmail.com>
947  */
948 #define LINKTYPE_USBPCAP	249
949 
950 /*
951  * Schweitzer Engineering Laboratories "RTAC" product serial-line
952  * packets.
953  *
954  * Requested by Chris Bontje <chris_bontje@selinc.com>.
955  */
956 #define LINKTYPE_RTAC_SERIAL		250
957 
958 /*
959  * Bluetooth Low Energy air interface link-layer packets.
960  *
961  * Requested by Mike Kershaw <dragorn@kismetwireless.net>.
962  */
963 #define LINKTYPE_BLUETOOTH_LE_LL	251
964 
965 /*
966  * Link-layer header type for upper-protocol layer PDU saves from wireshark.
967  *
968  * the actual contents are determined by two TAGs, one or more of
969  * which is stored with each packet:
970  *
971  *   EXP_PDU_TAG_DISSECTOR_NAME      the name of the Wireshark dissector
972  *				     that can make sense of the data stored.
973  *
974  *   EXP_PDU_TAG_HEUR_DISSECTOR_NAME the name of the Wireshark heuristic
975  *				     dissector that can make sense of the
976  *				     data stored.
977  */
978 #define LINKTYPE_WIRESHARK_UPPER_PDU	252
979 
980 /*
981  * Link-layer header type for the netlink protocol (nlmon devices).
982  */
983 #define LINKTYPE_NETLINK		253
984 
985 /*
986  * Bluetooth Linux Monitor headers for the BlueZ stack.
987  */
988 #define LINKTYPE_BLUETOOTH_LINUX_MONITOR	254
989 
990 /*
991  * Bluetooth Basic Rate/Enhanced Data Rate baseband packets, as
992  * captured by Ubertooth.
993  */
994 #define LINKTYPE_BLUETOOTH_BREDR_BB	255
995 
996 /*
997  * Bluetooth Low Energy link layer packets, as captured by Ubertooth.
998  */
999 #define LINKTYPE_BLUETOOTH_LE_LL_WITH_PHDR	256
1000 
1001 /*
1002  * PROFIBUS data link layer.
1003  */
1004 #define LINKTYPE_PROFIBUS_DL		257
1005 
1006 /*
1007  * Apple's DLT_PKTAP headers.
1008  *
1009  * Sadly, the folks at Apple either had no clue that the DLT_USERn values
1010  * are for internal use within an organization and partners only, and
1011  * didn't know that the right way to get a link-layer header type is to
1012  * ask tcpdump.org for one, or knew and didn't care, so they just
1013  * used DLT_USER2, which causes problems for everything except for
1014  * their version of tcpdump.
1015  *
1016  * So I'll just give them one; hopefully this will show up in a
1017  * libpcap release in time for them to get this into 10.10 Big Sur
1018  * or whatever Mavericks' successor is called.  LINKTYPE_PKTAP
1019  * will be 258 *even on macOS*; that is *intentional*, so that
1020  * PKTAP files look the same on *all* OSes (different OSes can have
1021  * different numerical values for a given DLT_, but *MUST NOT* have
1022  * different values for what goes in a file, as files can be moved
1023  * between OSes!).
1024  */
1025 #define LINKTYPE_PKTAP		258
1026 
1027 /*
1028  * Ethernet packets preceded by a header giving the last 6 octets
1029  * of the preamble specified by 802.3-2012 Clause 65, section
1030  * 65.1.3.2 "Transmit".
1031  */
1032 #define LINKTYPE_EPON		259
1033 
1034 /*
1035  * IPMI trace packets, as specified by Table 3-20 "Trace Data Block Format"
1036  * in the PICMG HPM.2 specification.
1037  */
1038 #define LINKTYPE_IPMI_HPM_2	260
1039 
1040 /*
1041  * per  Joshua Wright <jwright@hasborg.com>, formats for Zwave captures.
1042  */
1043 #define LINKTYPE_ZWAVE_R1_R2	261
1044 #define LINKTYPE_ZWAVE_R3	262
1045 
1046 /*
1047  * per Steve Karg <skarg@users.sourceforge.net>, formats for Wattstopper
1048  * Digital Lighting Management room bus serial protocol captures.
1049  */
1050 #define LINKTYPE_WATTSTOPPER_DLM 263
1051 
1052 /*
1053  * ISO 14443 contactless smart card messages.
1054  */
1055 #define LINKTYPE_ISO_14443      264
1056 
1057 /*
1058  * Radio data system (RDS) groups.  IEC 62106.
1059  * Per Jonathan Brucker <jonathan.brucke@gmail.com>.
1060  */
1061 #define LINKTYPE_RDS		265
1062 
1063 /*
1064  * USB packets, beginning with a Darwin (macOS, etc.) header.
1065  */
1066 #define LINKTYPE_USB_DARWIN	266
1067 
1068 /*
1069  * OpenBSD DLT_OPENFLOW.
1070  */
1071 #define LINKTYPE_OPENFLOW	267
1072 
1073 /*
1074  * SDLC frames containing SNA PDUs.
1075  */
1076 #define LINKTYPE_SDLC		268
1077 
1078 /*
1079  * per "Selvig, Bjorn" <b.selvig@ti.com> used for
1080  * TI protocol sniffer.
1081  */
1082 #define LINKTYPE_TI_LLN_SNIFFER	269
1083 
1084 /*
1085  * per: Erik de Jong <erikdejong at gmail.com> for
1086  *   https://github.com/eriknl/LoRaTap/releases/tag/v0.1
1087  */
1088 #define LINKTYPE_LORATAP        270
1089 
1090 /*
1091  * per: Stefanha at gmail.com for
1092  *   https://lists.sandelman.ca/pipermail/tcpdump-workers/2017-May/000772.html
1093  * and: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/vsockmon.h
1094  * for: https://qemu-project.org/Features/VirtioVsock
1095  */
1096 #define LINKTYPE_VSOCK          271
1097 
1098 /*
1099  * Nordic Semiconductor Bluetooth LE sniffer.
1100  */
1101 #define LINKTYPE_NORDIC_BLE	272
1102 
1103 /*
1104  * Excentis DOCSIS 3.1 RF sniffer (XRA-31)
1105  *   per: bruno.verstuyft at excentis.com
1106  *        https://www.xra31.com/xra-header
1107  */
1108 #define LINKTYPE_DOCSIS31_XRA31	273
1109 
1110 /*
1111  * mPackets, as specified by IEEE 802.3br Figure 99-4, starting
1112  * with the preamble and always ending with a CRC field.
1113  */
1114 #define LINKTYPE_ETHERNET_MPACKET	274
1115 
1116 /*
1117  * DisplayPort AUX channel monitoring data as specified by VESA
1118  * DisplayPort(DP) Standard preceded by a pseudo-header.
1119  *    per dirk.eibach at gdsys.cc
1120  */
1121 #define LINKTYPE_DISPLAYPORT_AUX	275
1122 
1123 /*
1124  * Linux cooked sockets v2.
1125  */
1126 #define LINKTYPE_LINUX_SLL2	276
1127 
1128 /*
1129  * Sercos Monitor, per Manuel Jacob <manuel.jacob at steinbeis-stg.de>
1130  */
1131 #define LINKTYPE_SERCOS_MONITOR 277
1132 
1133 /*
1134  * OpenVizsla http://openvizsla.org is open source USB analyzer hardware.
1135  * It consists of FPGA with attached USB phy and FTDI chip for streaming
1136  * the data to the host PC.
1137  *
1138  * Current OpenVizsla data encapsulation format is described here:
1139  * https://github.com/matwey/libopenvizsla/wiki/OpenVizsla-protocol-description
1140  *
1141  */
1142 #define LINKTYPE_OPENVIZSLA     278
1143 
1144 /*
1145  * The Elektrobit High Speed Capture and Replay (EBHSCR) protocol is produced
1146  * by a PCIe Card for interfacing high speed automotive interfaces.
1147  *
1148  * The specification for this frame format can be found at:
1149  *   https://www.elektrobit.com/ebhscr
1150  *
1151  * for Guenter.Ebermann at elektrobit.com
1152  *
1153  */
1154 #define LINKTYPE_EBHSCR	        279
1155 
1156 /*
1157  * The https://fd.io vpp graph dispatch tracer produces pcap trace files
1158  * in the format documented here:
1159  * https://fdio-vpp.readthedocs.io/en/latest/gettingstarted/developers/vnet.html#graph-dispatcher-pcap-tracing
1160  */
1161 #define LINKTYPE_VPP_DISPATCH	280
1162 
1163 /*
1164  * Broadcom Ethernet switches (ROBO switch) 4 bytes proprietary tagging format.
1165  */
1166 #define LINKTYPE_DSA_TAG_BRCM	281
1167 #define LINKTYPE_DSA_TAG_BRCM_PREPEND	282
1168 
1169 /*
1170  * IEEE 802.15.4 with pseudo-header and optional meta-data TLVs, PHY payload
1171  * exactly as it appears in the spec (no padding, no nothing), and FCS if
1172  * specified by FCS Type TLV;  requested by James Ko <jck@exegin.com>.
1173  * Specification at https://github.com/jkcko/ieee802.15.4-tap
1174  */
1175 #define LINKTYPE_IEEE802_15_4_TAP       283
1176 
1177 /*
1178  * Marvell (Ethertype) Distributed Switch Architecture proprietary tagging format.
1179  */
1180 #define LINKTYPE_DSA_TAG_DSA	284
1181 #define LINKTYPE_DSA_TAG_EDSA	285
1182 
1183 /*
1184  * Payload of lawful intercept packets using the ELEE protocol;
1185  * https://socket.hr/draft-dfranusic-opsawg-elee-00.xml
1186  * https://xml2rfc.tools.ietf.org/cgi-bin/xml2rfc.cgi?url=https://socket.hr/draft-dfranusic-opsawg-elee-00.xml&modeAsFormat=html/ascii
1187  */
1188 #define LINKTYPE_ELEE		286
1189 
1190 /*
1191  * Serial frames transmitted between a host and a Z-Wave chip.
1192  */
1193 #define LINKTYPE_Z_WAVE_SERIAL	287
1194 
1195 /*
1196  * USB 2.0, 1.1, and 1.0 packets as transmitted over the cable.
1197  */
1198 #define LINKTYPE_USB_2_0	288
1199 
1200 /*
1201  * ATSC Link-Layer Protocol (A/330) packets.
1202  */
1203 #define LINKTYPE_ATSC_ALP	289
1204 
1205 #define LINKTYPE_MATCHING_MAX	289		/* highest value in the "matching" range */
1206 
1207 /*
1208  * The DLT_ and LINKTYPE_ values in the "matching" range should be the
1209  * same, so DLT_MATCHING_MAX and LINKTYPE_MATCHING_MAX should be the
1210  * same.
1211  */
1212 #if LINKTYPE_MATCHING_MAX != DLT_MATCHING_MAX
1213 #error The LINKTYPE_ matching range does not match the DLT_ matching range
1214 #endif
1215 
1216 static struct linktype_map {
1217 	int	dlt;
1218 	int	linktype;
1219 } map[] = {
1220 	/*
1221 	 * These DLT_* codes have LINKTYPE_* codes with values identical
1222 	 * to the values of the corresponding DLT_* code.
1223 	 */
1224 	{ DLT_NULL,		LINKTYPE_NULL },
1225 	{ DLT_EN10MB,		LINKTYPE_ETHERNET },
1226 	{ DLT_EN3MB,		LINKTYPE_EXP_ETHERNET },
1227 	{ DLT_AX25,		LINKTYPE_AX25 },
1228 	{ DLT_PRONET,		LINKTYPE_PRONET },
1229 	{ DLT_CHAOS,		LINKTYPE_CHAOS },
1230 	{ DLT_IEEE802,		LINKTYPE_IEEE802_5 },
1231 	{ DLT_ARCNET,		LINKTYPE_ARCNET_BSD },
1232 	{ DLT_SLIP,		LINKTYPE_SLIP },
1233 	{ DLT_PPP,		LINKTYPE_PPP },
1234 	{ DLT_FDDI,		LINKTYPE_FDDI },
1235 	{ DLT_SYMANTEC_FIREWALL, LINKTYPE_SYMANTEC_FIREWALL },
1236 
1237 	/*
1238 	 * These DLT_* codes have different values on different
1239 	 * platforms; we map them to LINKTYPE_* codes that
1240 	 * have values that should never be equal to any DLT_*
1241 	 * code.
1242 	 */
1243 #ifdef DLT_FR
1244 	/* BSD/OS Frame Relay */
1245 	{ DLT_FR,		LINKTYPE_FRELAY },
1246 #endif
1247 
1248 	{ DLT_ATM_RFC1483,	LINKTYPE_ATM_RFC1483 },
1249 	{ DLT_RAW,		LINKTYPE_RAW },
1250 	{ DLT_SLIP_BSDOS,	LINKTYPE_SLIP_BSDOS },
1251 	{ DLT_PPP_BSDOS,	LINKTYPE_PPP_BSDOS },
1252 	{ DLT_HDLC,		LINKTYPE_NETBSD_HDLC },
1253 
1254 	/* BSD/OS Cisco HDLC */
1255 	{ DLT_C_HDLC,		LINKTYPE_C_HDLC },
1256 
1257 	/*
1258 	 * These DLT_* codes are not on all platforms, but, so far,
1259 	 * there don't appear to be any platforms that define
1260 	 * other codes with those values; we map them to
1261 	 * different LINKTYPE_* values anyway, just in case.
1262 	 */
1263 
1264 	/* Linux ATM Classical IP */
1265 	{ DLT_ATM_CLIP,		LINKTYPE_ATM_CLIP },
1266 
1267 	/* NetBSD sync/async serial PPP (or Cisco HDLC) */
1268 	{ DLT_PPP_SERIAL,	LINKTYPE_PPP_HDLC },
1269 
1270 	/* NetBSD PPP over Ethernet */
1271 	{ DLT_PPP_ETHER,	LINKTYPE_PPP_ETHER },
1272 
1273 	/*
1274 	 * All LINKTYPE_ values between LINKTYPE_MATCHING_MIN
1275 	 * and LINKTYPE_MATCHING_MAX are mapped to identical
1276 	 * DLT_ values.
1277 	 */
1278 
1279 	{ -1,			-1 }
1280 };
1281 
1282 int
1283 dlt_to_linktype(int dlt)
1284 {
1285 	int i;
1286 
1287 	/*
1288 	 * DLTs that, on some platforms, have values in the matching range
1289 	 * but that *don't* have the same value as the corresponding
1290 	 * LINKTYPE because, for some reason, not all OSes have the
1291 	 * same value for that DLT (note that the DLT's value might be
1292 	 * outside the matching range on some of those OSes).
1293 	 */
1294 	if (dlt == DLT_PFSYNC)
1295 		return (LINKTYPE_PFSYNC);
1296 	if (dlt == DLT_PKTAP)
1297 		return (LINKTYPE_PKTAP);
1298 
1299 	/*
1300 	 * For all other values in the matching range, the DLT
1301 	 * value is the same as the LINKTYPE value.
1302 	 */
1303 	if (dlt >= DLT_MATCHING_MIN && dlt <= DLT_MATCHING_MAX)
1304 		return (dlt);
1305 
1306 	/*
1307 	 * Map the values outside that range.
1308 	 */
1309 	for (i = 0; map[i].dlt != -1; i++) {
1310 		if (map[i].dlt == dlt)
1311 			return (map[i].linktype);
1312 	}
1313 
1314 	/*
1315 	 * If we don't have a mapping for this DLT, return an
1316 	 * error; that means that this is a value with no corresponding
1317 	 * LINKTYPE, and we need to assign one.
1318 	 */
1319 	return (-1);
1320 }
1321 
1322 int
1323 linktype_to_dlt(int linktype)
1324 {
1325 	int i;
1326 
1327 	/*
1328 	 * LINKTYPEs in the matching range that *don't*
1329 	 * have the same value as the corresponding DLTs
1330 	 * because, for some reason, not all OSes have the
1331 	 * same value for that DLT.
1332 	 */
1333 	if (linktype == LINKTYPE_PFSYNC)
1334 		return (DLT_PFSYNC);
1335 	if (linktype == LINKTYPE_PKTAP)
1336 		return (DLT_PKTAP);
1337 
1338 	/*
1339 	 * For all other values in the matching range, except for
1340 	 * LINKTYPE_ATM_CLIP, the LINKTYPE value is the same as
1341 	 * the DLT value.
1342 	 *
1343 	 * LINKTYPE_ATM_CLIP is a special case.  DLT_ATM_CLIP is
1344 	 * not on all platforms, but, so far, there don't appear
1345 	 * to be any platforms that define it as anything other
1346 	 * than 19; we define LINKTYPE_ATM_CLIP as something
1347 	 * other than 19, just in case.  That value is in the
1348 	 * matching range, so we have to check for it.
1349 	 */
1350 	if (linktype >= LINKTYPE_MATCHING_MIN &&
1351 	    linktype <= LINKTYPE_MATCHING_MAX &&
1352 	    linktype != LINKTYPE_ATM_CLIP)
1353 		return (linktype);
1354 
1355 	/*
1356 	 * Map the values outside that range.
1357 	 */
1358 	for (i = 0; map[i].linktype != -1; i++) {
1359 		if (map[i].linktype == linktype)
1360 			return (map[i].dlt);
1361 	}
1362 
1363 	/*
1364 	 * If we don't have an entry for this LINKTYPE, return
1365 	 * the link type value; it may be a DLT from an newer
1366 	 * version of libpcap.
1367 	 */
1368 	return linktype;
1369 }
1370 
1371 /*
1372  * Return the maximum snapshot length for a given DLT_ value.
1373  *
1374  * For most link-layer types, we use MAXIMUM_SNAPLEN.
1375  *
1376  * For DLT_DBUS, the maximum is 128MiB, as per
1377  *
1378  *    https://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-messages
1379  *
1380  * For DLT_EBHSCR, the maximum is 8MiB, as per
1381  *
1382  *    https://www.elektrobit.com/ebhscr
1383  *
1384  * For DLT_USBPCAP, the maximum is 1MiB, as per
1385  *
1386  *    https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=15985
1387  */
1388 u_int
1389 max_snaplen_for_dlt(int dlt)
1390 {
1391 	switch (dlt) {
1392 
1393 	case DLT_DBUS:
1394 		return 128*1024*1024;
1395 
1396 	case DLT_EBHSCR:
1397 		return 8*1024*1024;
1398 
1399 	case DLT_USBPCAP:
1400 		return 1024*1024;
1401 
1402 	default:
1403 		return MAXIMUM_SNAPLEN;
1404 	}
1405 }
1406