xref: /freebsd/contrib/libpcap/pcap-common.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*
2  * Copyright (c) 1993, 1994, 1995, 1996, 1997
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that: (1) source code distributions
7  * retain the above copyright notice and this paragraph in its entirety, (2)
8  * distributions including binary code include the above copyright notice and
9  * this paragraph in its entirety in the documentation or other materials
10  * provided with the distribution, and (3) all advertising materials mentioning
11  * features or use of this software display the following acknowledgement:
12  * ``This product includes software developed by the University of California,
13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14  * the University nor the names of its contributors may be used to endorse
15  * or promote products derived from this software without specific prior
16  * written permission.
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20  *
21  * pcap-common.c - common code for pcap and pcap-ng files
22  */
23 
24 #ifdef HAVE_CONFIG_H
25 #include "config.h"
26 #endif
27 
28 #ifdef _WIN32
29 #include <pcap-stdinc.h>
30 #else /* _WIN32 */
31 #if HAVE_INTTYPES_H
32 #include <inttypes.h>
33 #elif HAVE_STDINT_H
34 #include <stdint.h>
35 #endif
36 #ifdef HAVE_SYS_BITYPES_H
37 #include <sys/bitypes.h>
38 #endif
39 #include <sys/types.h>
40 #endif /* _WIN32 */
41 
42 #include "pcap-int.h"
43 #include "extract.h"
44 #include "pcap/sll.h"
45 #include "pcap/usb.h"
46 #include "pcap/nflog.h"
47 #include "pcap/can_socketcan.h"
48 
49 #include "pcap-common.h"
50 
51 /*
52  * We don't write DLT_* values to capture files, because they're not the
53  * same on all platforms.
54  *
55  * Unfortunately, the various flavors of BSD have not always used the same
56  * numerical values for the same data types, and various patches to
57  * libpcap for non-BSD OSes have added their own DLT_* codes for link
58  * layer encapsulation types seen on those OSes, and those codes have had,
59  * in some cases, values that were also used, on other platforms, for other
60  * link layer encapsulation types.
61  *
62  * This means that capture files of a type whose numerical DLT_* code
63  * means different things on different BSDs, or with different versions
64  * of libpcap, can't always be read on systems other than those like
65  * the one running on the machine on which the capture was made.
66  *
67  * Instead, we define here a set of LINKTYPE_* codes, and map DLT_* codes
68  * to LINKTYPE_* codes when writing a savefile header, and map LINKTYPE_*
69  * codes to DLT_* codes when reading a savefile header.
70  *
71  * For those DLT_* codes that have, as far as we know, the same values on
72  * all platforms (DLT_NULL through DLT_FDDI), we define LINKTYPE_xxx as
73  * DLT_xxx; that way, captures of those types can still be read by
74  * versions of libpcap that map LINKTYPE_* values to DLT_* values, and
75  * captures of those types written by versions of libpcap that map DLT_
76  * values to LINKTYPE_ values can still be read by older versions
77  * of libpcap.
78  *
79  * The other LINKTYPE_* codes are given values starting at 100, in the
80  * hopes that no DLT_* code will be given one of those values.
81  *
82  * In order to ensure that a given LINKTYPE_* code's value will refer to
83  * the same encapsulation type on all platforms, you should not allocate
84  * a new LINKTYPE_* value without consulting
85  * "tcpdump-workers@lists.tcpdump.org".  The tcpdump developers will
86  * allocate a value for you, and will not subsequently allocate it to
87  * anybody else; that value will be added to the "pcap.h" in the
88  * tcpdump.org Git repository, so that a future libpcap release will
89  * include it.
90  *
91  * You should, if possible, also contribute patches to libpcap and tcpdump
92  * to handle the new encapsulation type, so that they can also be checked
93  * into the tcpdump.org Git repository and so that they will appear in
94  * future libpcap and tcpdump releases.
95  *
96  * Do *NOT* assume that any values after the largest value in this file
97  * are available; you might not have the most up-to-date version of this
98  * file, and new values after that one might have been assigned.  Also,
99  * do *NOT* use any values below 100 - those might already have been
100  * taken by one (or more!) organizations.
101  *
102  * Any platform that defines additional DLT_* codes should:
103  *
104  *	request a LINKTYPE_* code and value from tcpdump.org,
105  *	as per the above;
106  *
107  *	add, in their version of libpcap, an entry to map
108  *	those DLT_* codes to the corresponding LINKTYPE_*
109  *	code;
110  *
111  *	redefine, in their "net/bpf.h", any DLT_* values
112  *	that collide with the values used by their additional
113  *	DLT_* codes, to remove those collisions (but without
114  *	making them collide with any of the LINKTYPE_*
115  *	values equal to 50 or above; they should also avoid
116  *	defining DLT_* values that collide with those
117  *	LINKTYPE_* values, either).
118  */
119 #define LINKTYPE_NULL		DLT_NULL
120 #define LINKTYPE_ETHERNET	DLT_EN10MB	/* also for 100Mb and up */
121 #define LINKTYPE_EXP_ETHERNET	DLT_EN3MB	/* 3Mb experimental Ethernet */
122 #define LINKTYPE_AX25		DLT_AX25
123 #define LINKTYPE_PRONET		DLT_PRONET
124 #define LINKTYPE_CHAOS		DLT_CHAOS
125 #define LINKTYPE_IEEE802_5	DLT_IEEE802	/* DLT_IEEE802 is used for 802.5 Token Ring */
126 #define LINKTYPE_ARCNET_BSD	DLT_ARCNET	/* BSD-style headers */
127 #define LINKTYPE_SLIP		DLT_SLIP
128 #define LINKTYPE_PPP		DLT_PPP
129 #define LINKTYPE_FDDI		DLT_FDDI
130 
131 /*
132  * LINKTYPE_PPP is for use when there might, or might not, be an RFC 1662
133  * PPP in HDLC-like framing header (with 0xff 0x03 before the PPP protocol
134  * field) at the beginning of the packet.
135  *
136  * This is for use when there is always such a header; the address field
137  * might be 0xff, for regular PPP, or it might be an address field for Cisco
138  * point-to-point with HDLC framing as per section 4.3.1 of RFC 1547 ("Cisco
139  * HDLC").  This is, for example, what you get with NetBSD's DLT_PPP_SERIAL.
140  *
141  * We give it the same value as NetBSD's DLT_PPP_SERIAL, in the hopes that
142  * nobody else will choose a DLT_ value of 50, and so that DLT_PPP_SERIAL
143  * captures will be written out with a link type that NetBSD's tcpdump
144  * can read.
145  */
146 #define LINKTYPE_PPP_HDLC	50		/* PPP in HDLC-like framing */
147 
148 #define LINKTYPE_PPP_ETHER	51		/* NetBSD PPP-over-Ethernet */
149 
150 #define LINKTYPE_SYMANTEC_FIREWALL 99		/* Symantec Enterprise Firewall */
151 
152 /*
153  * These correspond to DLT_s that have different values on different
154  * platforms; we map between these values in capture files and
155  * the DLT_ values as returned by pcap_datalink() and passed to
156  * pcap_open_dead().
157  */
158 #define LINKTYPE_ATM_RFC1483	100		/* LLC/SNAP-encapsulated ATM */
159 #define LINKTYPE_RAW		101		/* raw IP */
160 #define LINKTYPE_SLIP_BSDOS	102		/* BSD/OS SLIP BPF header */
161 #define LINKTYPE_PPP_BSDOS	103		/* BSD/OS PPP BPF header */
162 
163 /*
164  * Values starting with 104 are used for newly-assigned link-layer
165  * header type values; for those link-layer header types, the DLT_
166  * value returned by pcap_datalink() and passed to pcap_open_dead(),
167  * and the LINKTYPE_ value that appears in capture files, are the
168  * same.
169  *
170  * LINKTYPE_MATCHING_MIN is the lowest such value; LINKTYPE_MATCHING_MAX
171  * is the highest such value.
172  */
173 #define LINKTYPE_MATCHING_MIN	104		/* lowest value in the "matching" range */
174 
175 #define LINKTYPE_C_HDLC		104		/* Cisco HDLC */
176 #define LINKTYPE_IEEE802_11	105		/* IEEE 802.11 (wireless) */
177 #define LINKTYPE_ATM_CLIP	106		/* Linux Classical IP over ATM */
178 #define LINKTYPE_FRELAY		107		/* Frame Relay */
179 #define LINKTYPE_LOOP		108		/* OpenBSD loopback */
180 #define LINKTYPE_ENC		109		/* OpenBSD IPSEC enc */
181 
182 /*
183  * These three types are reserved for future use.
184  */
185 #define LINKTYPE_LANE8023	110		/* ATM LANE + 802.3 */
186 #define LINKTYPE_HIPPI		111		/* NetBSD HIPPI */
187 #define LINKTYPE_HDLC		112		/* NetBSD HDLC framing */
188 
189 #define LINKTYPE_LINUX_SLL	113		/* Linux cooked socket capture */
190 #define LINKTYPE_LTALK		114		/* Apple LocalTalk hardware */
191 #define LINKTYPE_ECONET		115		/* Acorn Econet */
192 
193 /*
194  * Reserved for use with OpenBSD ipfilter.
195  */
196 #define LINKTYPE_IPFILTER	116
197 
198 #define LINKTYPE_PFLOG		117		/* OpenBSD DLT_PFLOG */
199 #define LINKTYPE_CISCO_IOS	118		/* For Cisco-internal use */
200 #define LINKTYPE_IEEE802_11_PRISM 119		/* 802.11 plus Prism II monitor mode radio metadata header */
201 #define LINKTYPE_IEEE802_11_AIRONET 120		/* 802.11 plus FreeBSD Aironet driver radio metadata header */
202 
203 /*
204  * Reserved for Siemens HiPath HDLC.
205  */
206 #define LINKTYPE_HHDLC		121
207 
208 #define LINKTYPE_IP_OVER_FC	122		/* RFC 2625 IP-over-Fibre Channel */
209 #define LINKTYPE_SUNATM		123		/* Solaris+SunATM */
210 
211 /*
212  * Reserved as per request from Kent Dahlgren <kent@praesum.com>
213  * for private use.
214  */
215 #define LINKTYPE_RIO		124		/* RapidIO */
216 #define LINKTYPE_PCI_EXP	125		/* PCI Express */
217 #define LINKTYPE_AURORA		126		/* Xilinx Aurora link layer */
218 
219 #define LINKTYPE_IEEE802_11_RADIOTAP 127	/* 802.11 plus radiotap radio metadata header */
220 
221 /*
222  * Reserved for the TZSP encapsulation, as per request from
223  * Chris Waters <chris.waters@networkchemistry.com>
224  * TZSP is a generic encapsulation for any other link type,
225  * which includes a means to include meta-information
226  * with the packet, e.g. signal strength and channel
227  * for 802.11 packets.
228  */
229 #define LINKTYPE_TZSP		128		/* Tazmen Sniffer Protocol */
230 
231 #define LINKTYPE_ARCNET_LINUX	129		/* Linux-style headers */
232 
233 /*
234  * Juniper-private data link types, as per request from
235  * Hannes Gredler <hannes@juniper.net>.  The corresponding
236  * DLT_s are used for passing on chassis-internal
237  * metainformation such as QOS profiles, etc..
238  */
239 #define LINKTYPE_JUNIPER_MLPPP  130
240 #define LINKTYPE_JUNIPER_MLFR   131
241 #define LINKTYPE_JUNIPER_ES     132
242 #define LINKTYPE_JUNIPER_GGSN   133
243 #define LINKTYPE_JUNIPER_MFR    134
244 #define LINKTYPE_JUNIPER_ATM2   135
245 #define LINKTYPE_JUNIPER_SERVICES 136
246 #define LINKTYPE_JUNIPER_ATM1   137
247 
248 #define LINKTYPE_APPLE_IP_OVER_IEEE1394 138	/* Apple IP-over-IEEE 1394 cooked header */
249 
250 #define LINKTYPE_MTP2_WITH_PHDR	139
251 #define LINKTYPE_MTP2		140
252 #define LINKTYPE_MTP3		141
253 #define LINKTYPE_SCCP		142
254 
255 #define LINKTYPE_DOCSIS		143		/* DOCSIS MAC frames */
256 
257 #define LINKTYPE_LINUX_IRDA	144		/* Linux-IrDA */
258 
259 /*
260  * Reserved for IBM SP switch and IBM Next Federation switch.
261  */
262 #define LINKTYPE_IBM_SP		145
263 #define LINKTYPE_IBM_SN		146
264 
265 /*
266  * Reserved for private use.  If you have some link-layer header type
267  * that you want to use within your organization, with the capture files
268  * using that link-layer header type not ever be sent outside your
269  * organization, you can use these values.
270  *
271  * No libpcap release will use these for any purpose, nor will any
272  * tcpdump release use them, either.
273  *
274  * Do *NOT* use these in capture files that you expect anybody not using
275  * your private versions of capture-file-reading tools to read; in
276  * particular, do *NOT* use them in products, otherwise you may find that
277  * people won't be able to use tcpdump, or snort, or Ethereal, or... to
278  * read capture files from your firewall/intrusion detection/traffic
279  * monitoring/etc. appliance, or whatever product uses that LINKTYPE_ value,
280  * and you may also find that the developers of those applications will
281  * not accept patches to let them read those files.
282  *
283  * Also, do not use them if somebody might send you a capture using them
284  * for *their* private type and tools using them for *your* private type
285  * would have to read them.
286  *
287  * Instead, in those cases, ask "tcpdump-workers@lists.tcpdump.org" for a
288  * new DLT_ and LINKTYPE_ value, as per the comment in pcap/bpf.h, and use
289  * the type you're given.
290  */
291 #define LINKTYPE_USER0		147
292 #define LINKTYPE_USER1		148
293 #define LINKTYPE_USER2		149
294 #define LINKTYPE_USER3		150
295 #define LINKTYPE_USER4		151
296 #define LINKTYPE_USER5		152
297 #define LINKTYPE_USER6		153
298 #define LINKTYPE_USER7		154
299 #define LINKTYPE_USER8		155
300 #define LINKTYPE_USER9		156
301 #define LINKTYPE_USER10		157
302 #define LINKTYPE_USER11		158
303 #define LINKTYPE_USER12		159
304 #define LINKTYPE_USER13		160
305 #define LINKTYPE_USER14		161
306 #define LINKTYPE_USER15		162
307 
308 /*
309  * For future use with 802.11 captures - defined by AbsoluteValue
310  * Systems to store a number of bits of link-layer information
311  * including radio information:
312  *
313  *	http://www.shaftnet.org/~pizza/software/capturefrm.txt
314  */
315 #define LINKTYPE_IEEE802_11_AVS	163	/* 802.11 plus AVS radio metadata header */
316 
317 /*
318  * Juniper-private data link type, as per request from
319  * Hannes Gredler <hannes@juniper.net>.  The corresponding
320  * DLT_s are used for passing on chassis-internal
321  * metainformation such as QOS profiles, etc..
322  */
323 #define LINKTYPE_JUNIPER_MONITOR 164
324 
325 /*
326  * BACnet MS/TP frames.
327  */
328 #define LINKTYPE_BACNET_MS_TP	165
329 
330 /*
331  * Another PPP variant as per request from Karsten Keil <kkeil@suse.de>.
332  *
333  * This is used in some OSes to allow a kernel socket filter to distinguish
334  * between incoming and outgoing packets, on a socket intended to
335  * supply pppd with outgoing packets so it can do dial-on-demand and
336  * hangup-on-lack-of-demand; incoming packets are filtered out so they
337  * don't cause pppd to hold the connection up (you don't want random
338  * input packets such as port scans, packets from old lost connections,
339  * etc. to force the connection to stay up).
340  *
341  * The first byte of the PPP header (0xff03) is modified to accomodate
342  * the direction - 0x00 = IN, 0x01 = OUT.
343  */
344 #define LINKTYPE_PPP_PPPD	166
345 
346 /*
347  * Juniper-private data link type, as per request from
348  * Hannes Gredler <hannes@juniper.net>.  The DLT_s are used
349  * for passing on chassis-internal metainformation such as
350  * QOS profiles, cookies, etc..
351  */
352 #define LINKTYPE_JUNIPER_PPPOE     167
353 #define LINKTYPE_JUNIPER_PPPOE_ATM 168
354 
355 #define LINKTYPE_GPRS_LLC	169		/* GPRS LLC */
356 #define LINKTYPE_GPF_T		170		/* GPF-T (ITU-T G.7041/Y.1303) */
357 #define LINKTYPE_GPF_F		171		/* GPF-F (ITU-T G.7041/Y.1303) */
358 
359 /*
360  * Requested by Oolan Zimmer <oz@gcom.com> for use in Gcom's T1/E1 line
361  * monitoring equipment.
362  */
363 #define LINKTYPE_GCOM_T1E1	172
364 #define LINKTYPE_GCOM_SERIAL	173
365 
366 /*
367  * Juniper-private data link type, as per request from
368  * Hannes Gredler <hannes@juniper.net>.  The DLT_ is used
369  * for internal communication to Physical Interface Cards (PIC)
370  */
371 #define LINKTYPE_JUNIPER_PIC_PEER    174
372 
373 /*
374  * Link types requested by Gregor Maier <gregor@endace.com> of Endace
375  * Measurement Systems.  They add an ERF header (see
376  * http://www.endace.com/support/EndaceRecordFormat.pdf) in front of
377  * the link-layer header.
378  */
379 #define LINKTYPE_ERF_ETH	175	/* Ethernet */
380 #define LINKTYPE_ERF_POS	176	/* Packet-over-SONET */
381 
382 /*
383  * Requested by Daniele Orlandi <daniele@orlandi.com> for raw LAPD
384  * for vISDN (http://www.orlandi.com/visdn/).  Its link-layer header
385  * includes additional information before the LAPD header, so it's
386  * not necessarily a generic LAPD header.
387  */
388 #define LINKTYPE_LINUX_LAPD	177
389 
390 /*
391  * Juniper-private data link type, as per request from
392  * Hannes Gredler <hannes@juniper.net>.
393  * The Link Types are used for prepending meta-information
394  * like interface index, interface name
395  * before standard Ethernet, PPP, Frelay & C-HDLC Frames
396  */
397 #define LINKTYPE_JUNIPER_ETHER  178
398 #define LINKTYPE_JUNIPER_PPP    179
399 #define LINKTYPE_JUNIPER_FRELAY 180
400 #define LINKTYPE_JUNIPER_CHDLC  181
401 
402 /*
403  * Multi Link Frame Relay (FRF.16)
404  */
405 #define LINKTYPE_MFR            182
406 
407 /*
408  * Juniper-private data link type, as per request from
409  * Hannes Gredler <hannes@juniper.net>.
410  * The DLT_ is used for internal communication with a
411  * voice Adapter Card (PIC)
412  */
413 #define LINKTYPE_JUNIPER_VP     183
414 
415 /*
416  * Arinc 429 frames.
417  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
418  * Every frame contains a 32bit A429 label.
419  * More documentation on Arinc 429 can be found at
420  * http://www.condoreng.com/support/downloads/tutorials/ARINCTutorial.pdf
421  */
422 #define LINKTYPE_A429           184
423 
424 /*
425  * Arinc 653 Interpartition Communication messages.
426  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
427  * Please refer to the A653-1 standard for more information.
428  */
429 #define LINKTYPE_A653_ICM       185
430 
431 /*
432  * This used to be "USB packets, beginning with a USB setup header;
433  * requested by Paolo Abeni <paolo.abeni@email.it>."
434  *
435  * However, that header didn't work all that well - it left out some
436  * useful information - and was abandoned in favor of the DLT_USB_LINUX
437  * header.
438  *
439  * This is now used by FreeBSD for its BPF taps for USB; that has its
440  * own headers.  So it is written, so it is done.
441  */
442 #define LINKTYPE_USB_FREEBSD	186
443 
444 /*
445  * Bluetooth HCI UART transport layer (part H:4); requested by
446  * Paolo Abeni.
447  */
448 #define LINKTYPE_BLUETOOTH_HCI_H4	187
449 
450 /*
451  * IEEE 802.16 MAC Common Part Sublayer; requested by Maria Cruz
452  * <cruz_petagay@bah.com>.
453  */
454 #define LINKTYPE_IEEE802_16_MAC_CPS	188
455 
456 /*
457  * USB packets, beginning with a Linux USB header; requested by
458  * Paolo Abeni <paolo.abeni@email.it>.
459  */
460 #define LINKTYPE_USB_LINUX		189
461 
462 /*
463  * Controller Area Network (CAN) v. 2.0B packets.
464  * DLT_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
465  * Used to dump CAN packets coming from a CAN Vector board.
466  * More documentation on the CAN v2.0B frames can be found at
467  * http://www.can-cia.org/downloads/?269
468  */
469 #define LINKTYPE_CAN20B         190
470 
471 /*
472  * IEEE 802.15.4, with address fields padded, as is done by Linux
473  * drivers; requested by Juergen Schimmer.
474  */
475 #define LINKTYPE_IEEE802_15_4_LINUX	191
476 
477 /*
478  * Per Packet Information encapsulated packets.
479  * LINKTYPE_ requested by Gianluca Varenni <gianluca.varenni@cacetech.com>.
480  */
481 #define LINKTYPE_PPI			192
482 
483 /*
484  * Header for 802.16 MAC Common Part Sublayer plus a radiotap radio header;
485  * requested by Charles Clancy.
486  */
487 #define LINKTYPE_IEEE802_16_MAC_CPS_RADIO	193
488 
489 /*
490  * Juniper-private data link type, as per request from
491  * Hannes Gredler <hannes@juniper.net>.
492  * The DLT_ is used for internal communication with a
493  * integrated service module (ISM).
494  */
495 #define LINKTYPE_JUNIPER_ISM    194
496 
497 /*
498  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
499  * nothing); requested by Mikko Saarnivala <mikko.saarnivala@sensinode.com>.
500  */
501 #define LINKTYPE_IEEE802_15_4	195
502 
503 /*
504  * Various link-layer types, with a pseudo-header, for SITA
505  * (http://www.sita.aero/); requested by Fulko Hew (fulko.hew@gmail.com).
506  */
507 #define LINKTYPE_SITA		196
508 
509 /*
510  * Various link-layer types, with a pseudo-header, for Endace DAG cards;
511  * encapsulates Endace ERF records.  Requested by Stephen Donnelly
512  * <stephen@endace.com>.
513  */
514 #define LINKTYPE_ERF		197
515 
516 /*
517  * Special header prepended to Ethernet packets when capturing from a
518  * u10 Networks board.  Requested by Phil Mulholland
519  * <phil@u10networks.com>.
520  */
521 #define LINKTYPE_RAIF1		198
522 
523 /*
524  * IPMB packet for IPMI, beginning with the I2C slave address, followed
525  * by the netFn and LUN, etc..  Requested by Chanthy Toeung
526  * <chanthy.toeung@ca.kontron.com>.
527  */
528 #define LINKTYPE_IPMB		199
529 
530 /*
531  * Juniper-private data link type, as per request from
532  * Hannes Gredler <hannes@juniper.net>.
533  * The DLT_ is used for capturing data on a secure tunnel interface.
534  */
535 #define LINKTYPE_JUNIPER_ST     200
536 
537 /*
538  * Bluetooth HCI UART transport layer (part H:4), with pseudo-header
539  * that includes direction information; requested by Paolo Abeni.
540  */
541 #define LINKTYPE_BLUETOOTH_HCI_H4_WITH_PHDR	201
542 
543 /*
544  * AX.25 packet with a 1-byte KISS header; see
545  *
546  *	http://www.ax25.net/kiss.htm
547  *
548  * as per Richard Stearn <richard@rns-stearn.demon.co.uk>.
549  */
550 #define LINKTYPE_AX25_KISS	202
551 
552 /*
553  * LAPD packets from an ISDN channel, starting with the address field,
554  * with no pseudo-header.
555  * Requested by Varuna De Silva <varunax@gmail.com>.
556  */
557 #define LINKTYPE_LAPD		203
558 
559 /*
560  * Variants of various link-layer headers, with a one-byte direction
561  * pseudo-header prepended - zero means "received by this host",
562  * non-zero (any non-zero value) means "sent by this host" - as per
563  * Will Barker <w.barker@zen.co.uk>.
564  */
565 #define LINKTYPE_PPP_WITH_DIR	204	/* PPP */
566 #define LINKTYPE_C_HDLC_WITH_DIR 205	/* Cisco HDLC */
567 #define LINKTYPE_FRELAY_WITH_DIR 206	/* Frame Relay */
568 #define LINKTYPE_LAPB_WITH_DIR	207	/* LAPB */
569 
570 /*
571  * 208 is reserved for an as-yet-unspecified proprietary link-layer
572  * type, as requested by Will Barker.
573  */
574 
575 /*
576  * IPMB with a Linux-specific pseudo-header; as requested by Alexey Neyman
577  * <avn@pigeonpoint.com>.
578  */
579 #define LINKTYPE_IPMB_LINUX	209
580 
581 /*
582  * FlexRay automotive bus - http://www.flexray.com/ - as requested
583  * by Hannes Kaelber <hannes.kaelber@x2e.de>.
584  */
585 #define LINKTYPE_FLEXRAY	210
586 
587 /*
588  * Media Oriented Systems Transport (MOST) bus for multimedia
589  * transport - http://www.mostcooperation.com/ - as requested
590  * by Hannes Kaelber <hannes.kaelber@x2e.de>.
591  */
592 #define LINKTYPE_MOST		211
593 
594 /*
595  * Local Interconnect Network (LIN) bus for vehicle networks -
596  * http://www.lin-subbus.org/ - as requested by Hannes Kaelber
597  * <hannes.kaelber@x2e.de>.
598  */
599 #define LINKTYPE_LIN		212
600 
601 /*
602  * X2E-private data link type used for serial line capture,
603  * as requested by Hannes Kaelber <hannes.kaelber@x2e.de>.
604  */
605 #define LINKTYPE_X2E_SERIAL	213
606 
607 /*
608  * X2E-private data link type used for the Xoraya data logger
609  * family, as requested by Hannes Kaelber <hannes.kaelber@x2e.de>.
610  */
611 #define LINKTYPE_X2E_XORAYA	214
612 
613 /*
614  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
615  * nothing), but with the PHY-level data for non-ASK PHYs (4 octets
616  * of 0 as preamble, one octet of SFD, one octet of frame length+
617  * reserved bit, and then the MAC-layer data, starting with the
618  * frame control field).
619  *
620  * Requested by Max Filippov <jcmvbkbc@gmail.com>.
621  */
622 #define LINKTYPE_IEEE802_15_4_NONASK_PHY	215
623 
624 /*
625  * David Gibson <david@gibson.dropbear.id.au> requested this for
626  * captures from the Linux kernel /dev/input/eventN devices. This
627  * is used to communicate keystrokes and mouse movements from the
628  * Linux kernel to display systems, such as Xorg.
629  */
630 #define LINKTYPE_LINUX_EVDEV	216
631 
632 /*
633  * GSM Um and Abis interfaces, preceded by a "gsmtap" header.
634  *
635  * Requested by Harald Welte <laforge@gnumonks.org>.
636  */
637 #define LINKTYPE_GSMTAP_UM	217
638 #define LINKTYPE_GSMTAP_ABIS	218
639 
640 /*
641  * MPLS, with an MPLS label as the link-layer header.
642  * Requested by Michele Marchetto <michele@openbsd.org> on behalf
643  * of OpenBSD.
644  */
645 #define LINKTYPE_MPLS		219
646 
647 /*
648  * USB packets, beginning with a Linux USB header, with the USB header
649  * padded to 64 bytes; required for memory-mapped access.
650  */
651 #define LINKTYPE_USB_LINUX_MMAPPED		220
652 
653 /*
654  * DECT packets, with a pseudo-header; requested by
655  * Matthias Wenzel <tcpdump@mazzoo.de>.
656  */
657 #define LINKTYPE_DECT		221
658 
659 /*
660  * From: "Lidwa, Eric (GSFC-582.0)[SGT INC]" <eric.lidwa-1@nasa.gov>
661  * Date: Mon, 11 May 2009 11:18:30 -0500
662  *
663  * DLT_AOS. We need it for AOS Space Data Link Protocol.
664  *   I have already written dissectors for but need an OK from
665  *   legal before I can submit a patch.
666  *
667  */
668 #define LINKTYPE_AOS		222
669 
670 /*
671  * Wireless HART (Highway Addressable Remote Transducer)
672  * From the HART Communication Foundation
673  * IES/PAS 62591
674  *
675  * Requested by Sam Roberts <vieuxtech@gmail.com>.
676  */
677 #define LINKTYPE_WIHART		223
678 
679 /*
680  * Fibre Channel FC-2 frames, beginning with a Frame_Header.
681  * Requested by Kahou Lei <kahou82@gmail.com>.
682  */
683 #define LINKTYPE_FC_2		224
684 
685 /*
686  * Fibre Channel FC-2 frames, beginning with an encoding of the
687  * SOF, and ending with an encoding of the EOF.
688  *
689  * The encodings represent the frame delimiters as 4-byte sequences
690  * representing the corresponding ordered sets, with K28.5
691  * represented as 0xBC, and the D symbols as the corresponding
692  * byte values; for example, SOFi2, which is K28.5 - D21.5 - D1.2 - D21.2,
693  * is represented as 0xBC 0xB5 0x55 0x55.
694  *
695  * Requested by Kahou Lei <kahou82@gmail.com>.
696  */
697 #define LINKTYPE_FC_2_WITH_FRAME_DELIMS		225
698 
699 /*
700  * Solaris ipnet pseudo-header; requested by Darren Reed <Darren.Reed@Sun.COM>.
701  *
702  * The pseudo-header starts with a one-byte version number; for version 2,
703  * the pseudo-header is:
704  *
705  * struct dl_ipnetinfo {
706  *     u_int8_t   dli_version;
707  *     u_int8_t   dli_family;
708  *     u_int16_t  dli_htype;
709  *     u_int32_t  dli_pktlen;
710  *     u_int32_t  dli_ifindex;
711  *     u_int32_t  dli_grifindex;
712  *     u_int32_t  dli_zsrc;
713  *     u_int32_t  dli_zdst;
714  * };
715  *
716  * dli_version is 2 for the current version of the pseudo-header.
717  *
718  * dli_family is a Solaris address family value, so it's 2 for IPv4
719  * and 26 for IPv6.
720  *
721  * dli_htype is a "hook type" - 0 for incoming packets, 1 for outgoing
722  * packets, and 2 for packets arriving from another zone on the same
723  * machine.
724  *
725  * dli_pktlen is the length of the packet data following the pseudo-header
726  * (so the captured length minus dli_pktlen is the length of the
727  * pseudo-header, assuming the entire pseudo-header was captured).
728  *
729  * dli_ifindex is the interface index of the interface on which the
730  * packet arrived.
731  *
732  * dli_grifindex is the group interface index number (for IPMP interfaces).
733  *
734  * dli_zsrc is the zone identifier for the source of the packet.
735  *
736  * dli_zdst is the zone identifier for the destination of the packet.
737  *
738  * A zone number of 0 is the global zone; a zone number of 0xffffffff
739  * means that the packet arrived from another host on the network, not
740  * from another zone on the same machine.
741  *
742  * An IPv4 or IPv6 datagram follows the pseudo-header; dli_family indicates
743  * which of those it is.
744  */
745 #define LINKTYPE_IPNET		226
746 
747 /*
748  * CAN (Controller Area Network) frames, with a pseudo-header as supplied
749  * by Linux SocketCAN, and with multi-byte numerical fields in that header
750  * in big-endian byte order.
751  *
752  * See Documentation/networking/can.txt in the Linux source.
753  *
754  * Requested by Felix Obenhuber <felix@obenhuber.de>.
755  */
756 #define LINKTYPE_CAN_SOCKETCAN	227
757 
758 /*
759  * Raw IPv4/IPv6; different from DLT_RAW in that the DLT_ value specifies
760  * whether it's v4 or v6.  Requested by Darren Reed <Darren.Reed@Sun.COM>.
761  */
762 #define LINKTYPE_IPV4		228
763 #define LINKTYPE_IPV6		229
764 
765 /*
766  * IEEE 802.15.4, exactly as it appears in the spec (no padding, no
767  * nothing), and with no FCS at the end of the frame; requested by
768  * Jon Smirl <jonsmirl@gmail.com>.
769  */
770 #define LINKTYPE_IEEE802_15_4_NOFCS		230
771 
772 /*
773  * Raw D-Bus:
774  *
775  *	http://www.freedesktop.org/wiki/Software/dbus
776  *
777  * messages:
778  *
779  *	http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-messages
780  *
781  * starting with the endianness flag, followed by the message type, etc.,
782  * but without the authentication handshake before the message sequence:
783  *
784  *	http://dbus.freedesktop.org/doc/dbus-specification.html#auth-protocol
785  *
786  * Requested by Martin Vidner <martin@vidner.net>.
787  */
788 #define LINKTYPE_DBUS		231
789 
790 /*
791  * Juniper-private data link type, as per request from
792  * Hannes Gredler <hannes@juniper.net>.
793  */
794 #define LINKTYPE_JUNIPER_VS			232
795 #define LINKTYPE_JUNIPER_SRX_E2E		233
796 #define LINKTYPE_JUNIPER_FIBRECHANNEL		234
797 
798 /*
799  * DVB-CI (DVB Common Interface for communication between a PC Card
800  * module and a DVB receiver).  See
801  *
802  *	http://www.kaiser.cx/pcap-dvbci.html
803  *
804  * for the specification.
805  *
806  * Requested by Martin Kaiser <martin@kaiser.cx>.
807  */
808 #define LINKTYPE_DVB_CI		235
809 
810 /*
811  * Variant of 3GPP TS 27.010 multiplexing protocol.  Requested
812  * by Hans-Christoph Schemmel <hans-christoph.schemmel@cinterion.com>.
813  */
814 #define LINKTYPE_MUX27010	236
815 
816 /*
817  * STANAG 5066 D_PDUs.  Requested by M. Baris Demiray
818  * <barisdemiray@gmail.com>.
819  */
820 #define LINKTYPE_STANAG_5066_D_PDU		237
821 
822 /*
823  * Juniper-private data link type, as per request from
824  * Hannes Gredler <hannes@juniper.net>.
825  */
826 #define LINKTYPE_JUNIPER_ATM_CEMIC		238
827 
828 /*
829  * NetFilter LOG messages
830  * (payload of netlink NFNL_SUBSYS_ULOG/NFULNL_MSG_PACKET packets)
831  *
832  * Requested by Jakub Zawadzki <darkjames-ws@darkjames.pl>
833  */
834 #define LINKTYPE_NFLOG		239
835 
836 /*
837  * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type
838  * for Ethernet packets with a 4-byte pseudo-header and always
839  * with the payload including the FCS, as supplied by their
840  * netANALYZER hardware and software.
841  *
842  * Requested by Holger P. Frommer <HPfrommer@hilscher.com>
843  */
844 #define LINKTYPE_NETANALYZER	240
845 
846 /*
847  * Hilscher Gesellschaft fuer Systemautomation mbH link-layer type
848  * for Ethernet packets with a 4-byte pseudo-header and FCS and
849  * 1 byte of SFD, as supplied by their netANALYZER hardware and
850  * software.
851  *
852  * Requested by Holger P. Frommer <HPfrommer@hilscher.com>
853  */
854 #define LINKTYPE_NETANALYZER_TRANSPARENT	241
855 
856 /*
857  * IP-over-InfiniBand, as specified by RFC 4391.
858  *
859  * Requested by Petr Sumbera <petr.sumbera@oracle.com>.
860  */
861 #define LINKTYPE_IPOIB		242
862 
863 /*
864  * MPEG-2 transport stream (ISO 13818-1/ITU-T H.222.0).
865  *
866  * Requested by Guy Martin <gmsoft@tuxicoman.be>.
867  */
868 #define LINKTYPE_MPEG_2_TS	243
869 
870 /*
871  * ng4T GmbH's UMTS Iub/Iur-over-ATM and Iub/Iur-over-IP format as
872  * used by their ng40 protocol tester.
873  *
874  * Requested by Jens Grimmer <jens.grimmer@ng4t.com>.
875  */
876 #define LINKTYPE_NG40		244
877 
878 /*
879  * Pseudo-header giving adapter number and flags, followed by an NFC
880  * (Near-Field Communications) Logical Link Control Protocol (LLCP) PDU,
881  * as specified by NFC Forum Logical Link Control Protocol Technical
882  * Specification LLCP 1.1.
883  *
884  * Requested by Mike Wakerly <mikey@google.com>.
885  */
886 #define LINKTYPE_NFC_LLCP	245
887 
888 /*
889  * pfsync output; DLT_PFSYNC is 18, which collides with DLT_CIP in
890  * SuSE 6.3, on OpenBSD, NetBSD, DragonFly BSD, and Mac OS X, and
891  * is 121, which collides with DLT_HHDLC, in FreeBSD.  We pick a
892  * shiny new link-layer header type value that doesn't collide with
893  * anything, in the hopes that future pfsync savefiles, if any,
894  * won't require special hacks to distinguish from other savefiles.
895  *
896  */
897 #define LINKTYPE_PFSYNC		246
898 
899 /*
900  * Raw InfiniBand packets, starting with the Local Routing Header.
901  *
902  * Requested by Oren Kladnitsky <orenk@mellanox.com>.
903  */
904 #define LINKTYPE_INFINIBAND	247
905 
906 /*
907  * SCTP, with no lower-level protocols (i.e., no IPv4 or IPv6).
908  *
909  * Requested by Michael Tuexen <Michael.Tuexen@lurchi.franken.de>.
910  */
911 #define LINKTYPE_SCTP		248
912 
913 /*
914  * USB packets, beginning with a USBPcap header.
915  *
916  * Requested by Tomasz Mon <desowin@gmail.com>
917  */
918 #define LINKTYPE_USBPCAP	249
919 
920 /*
921  * Schweitzer Engineering Laboratories "RTAC" product serial-line
922  * packets.
923  *
924  * Requested by Chris Bontje <chris_bontje@selinc.com>.
925  */
926 #define DLT_RTAC_SERIAL		250
927 
928 /*
929  * Bluetooth Low Energy air interface link-layer packets.
930  *
931  * Requested by Mike Kershaw <dragorn@kismetwireless.net>.
932  */
933 #define LINKTYPE_BLUETOOTH_LE_LL	251
934 
935 /*
936  * Link-layer header type for upper-protocol layer PDU saves from wireshark.
937  *
938  * the actual contents are determined by two TAGs stored with each
939  * packet:
940  *   EXP_PDU_TAG_LINKTYPE          the link type (LINKTYPE_ value) of the
941  *				   original packet.
942  *
943  *   EXP_PDU_TAG_PROTO_NAME        the name of the wireshark dissector
944  * 				   that can make sense of the data stored.
945  */
946 #define LINKTYPE_WIRESHARK_UPPER_PDU	252
947 
948 /*
949  * Link-layer header type for the netlink protocol (nlmon devices).
950  */
951 #define LINKTYPE_NETLINK		253
952 
953 /*
954  * Bluetooth Linux Monitor headers for the BlueZ stack.
955  */
956 #define LINKTYPE_BLUETOOTH_LINUX_MONITOR	254
957 
958 /*
959  * Bluetooth Basic Rate/Enhanced Data Rate baseband packets, as
960  * captured by Ubertooth.
961  */
962 #define LINKTYPE_BLUETOOTH_BREDR_BB	255
963 
964 /*
965  * Bluetooth Low Energy link layer packets, as captured by Ubertooth.
966  */
967 #define LINKTYPE_BLUETOOTH_LE_LL_WITH_PHDR	256
968 
969 /*
970  * PROFIBUS data link layer.
971  */
972 #define LINKTYPE_PROFIBUS_DL		257
973 
974 /*
975  * Apple's DLT_PKTAP headers.
976  *
977  * Sadly, the folks at Apple either had no clue that the DLT_USERn values
978  * are for internal use within an organization and partners only, and
979  * didn't know that the right way to get a link-layer header type is to
980  * ask tcpdump.org for one, or knew and didn't care, so they just
981  * used DLT_USER2, which causes problems for everything except for
982  * their version of tcpdump.
983  *
984  * So I'll just give them one; hopefully this will show up in a
985  * libpcap release in time for them to get this into 10.10 Big Sur
986  * or whatever Mavericks' successor is called.  LINKTYPE_PKTAP
987  * will be 258 *even on OS X*; that is *intentional*, so that
988  * PKTAP files look the same on *all* OSes (different OSes can have
989  * different numerical values for a given DLT_, but *MUST NOT* have
990  * different values for what goes in a file, as files can be moved
991  * between OSes!).
992  */
993 #define LINKTYPE_PKTAP		258
994 
995 /*
996  * Ethernet packets preceded by a header giving the last 6 octets
997  * of the preamble specified by 802.3-2012 Clause 65, section
998  * 65.1.3.2 "Transmit".
999  */
1000 #define LINKTYPE_EPON		259
1001 
1002 /*
1003  * IPMI trace packets, as specified by Table 3-20 "Trace Data Block Format"
1004  * in the PICMG HPM.2 specification.
1005  */
1006 #define LINKTYPE_IPMI_HPM_2	260
1007 
1008 /*
1009  * per  Joshua Wright <jwright@hasborg.com>, formats for Zwave captures.
1010  */
1011 #define LINKTYPE_ZWAVE_R1_R2	261
1012 #define LINKTYPE_ZWAVE_R3	262
1013 
1014 /*
1015  * per Steve Karg <skarg@users.sourceforge.net>, formats for Wattstopper
1016  * Digital Lighting Management room bus serial protocol captures.
1017  */
1018 #define LINKTYPE_WATTSTOPPER_DLM 263
1019 
1020 /*
1021  * ISO 14443 contactless smart card messages.
1022  */
1023 #define LINKTYPE_ISO_14443      264
1024 
1025 /*
1026  * Radio data system (RDS) groups.  IEC 62106.
1027  * Per Jonathan Brucker <jonathan.brucke@gmail.com>.
1028  */
1029 #define LINKTYPE_RDS		265
1030 
1031 #define LINKTYPE_MATCHING_MAX	265		/* highest value in the "matching" range */
1032 
1033 static struct linktype_map {
1034 	int	dlt;
1035 	int	linktype;
1036 } map[] = {
1037 	/*
1038 	 * These DLT_* codes have LINKTYPE_* codes with values identical
1039 	 * to the values of the corresponding DLT_* code.
1040 	 */
1041 	{ DLT_NULL,		LINKTYPE_NULL },
1042 	{ DLT_EN10MB,		LINKTYPE_ETHERNET },
1043 	{ DLT_EN3MB,		LINKTYPE_EXP_ETHERNET },
1044 	{ DLT_AX25,		LINKTYPE_AX25 },
1045 	{ DLT_PRONET,		LINKTYPE_PRONET },
1046 	{ DLT_CHAOS,		LINKTYPE_CHAOS },
1047 	{ DLT_IEEE802,		LINKTYPE_IEEE802_5 },
1048 	{ DLT_ARCNET,		LINKTYPE_ARCNET_BSD },
1049 	{ DLT_SLIP,		LINKTYPE_SLIP },
1050 	{ DLT_PPP,		LINKTYPE_PPP },
1051 	{ DLT_FDDI,	 	LINKTYPE_FDDI },
1052 	{ DLT_SYMANTEC_FIREWALL, LINKTYPE_SYMANTEC_FIREWALL },
1053 
1054 	/*
1055 	 * These DLT_* codes have different values on different
1056 	 * platforms; we map them to LINKTYPE_* codes that
1057 	 * have values that should never be equal to any DLT_*
1058 	 * code.
1059 	 */
1060 #ifdef DLT_FR
1061 	/* BSD/OS Frame Relay */
1062 	{ DLT_FR,		LINKTYPE_FRELAY },
1063 #endif
1064 
1065 	{ DLT_ATM_RFC1483, 	LINKTYPE_ATM_RFC1483 },
1066 	{ DLT_RAW,		LINKTYPE_RAW },
1067 	{ DLT_SLIP_BSDOS,	LINKTYPE_SLIP_BSDOS },
1068 	{ DLT_PPP_BSDOS,	LINKTYPE_PPP_BSDOS },
1069 
1070 	/* BSD/OS Cisco HDLC */
1071 	{ DLT_C_HDLC,		LINKTYPE_C_HDLC },
1072 
1073 	/*
1074 	 * These DLT_* codes are not on all platforms, but, so far,
1075 	 * there don't appear to be any platforms that define
1076 	 * other codes with those values; we map them to
1077 	 * different LINKTYPE_* values anyway, just in case.
1078 	 */
1079 
1080 	/* Linux ATM Classical IP */
1081 	{ DLT_ATM_CLIP,		LINKTYPE_ATM_CLIP },
1082 
1083 	/* NetBSD sync/async serial PPP (or Cisco HDLC) */
1084 	{ DLT_PPP_SERIAL,	LINKTYPE_PPP_HDLC },
1085 
1086 	/* NetBSD PPP over Ethernet */
1087 	{ DLT_PPP_ETHER,	LINKTYPE_PPP_ETHER },
1088 
1089 	/*
1090 	 * All LINKTYPE_ values between LINKTYPE_MATCHING_MIN
1091 	 * and LINKTYPE_MATCHING_MAX are mapped to identical
1092 	 * DLT_ values.
1093 	 */
1094 
1095 	{ -1,			-1 }
1096 };
1097 
1098 int
1099 dlt_to_linktype(int dlt)
1100 {
1101 	int i;
1102 
1103 	/*
1104 	 * DLTs that, on some platforms, have values in the matching range
1105 	 * but that *don't* have the same value as the corresponding
1106 	 * LINKTYPE because, for some reason, not all OSes have the
1107 	 * same value for that DLT (note that the DLT's value might be
1108 	 * outside the matching range on some of those OSes).
1109 	 */
1110 	if (dlt == DLT_PFSYNC)
1111 		return (LINKTYPE_PFSYNC);
1112 	if (dlt == DLT_PKTAP)
1113 		return (LINKTYPE_PKTAP);
1114 
1115 	/*
1116 	 * For all other values in the matching range, the DLT
1117 	 * value is the same as the LINKTYPE value.
1118 	 */
1119 	if (dlt >= DLT_MATCHING_MIN && dlt <= DLT_MATCHING_MAX)
1120 		return (dlt);
1121 
1122 	/*
1123 	 * Map the values outside that range.
1124 	 */
1125 	for (i = 0; map[i].dlt != -1; i++) {
1126 		if (map[i].dlt == dlt)
1127 			return (map[i].linktype);
1128 	}
1129 
1130 	/*
1131 	 * If we don't have a mapping for this DLT, return an
1132 	 * error; that means that this is a value with no corresponding
1133 	 * LINKTYPE, and we need to assign one.
1134 	 */
1135 	return (-1);
1136 }
1137 
1138 int
1139 linktype_to_dlt(int linktype)
1140 {
1141 	int i;
1142 
1143 	/*
1144 	 * LINKTYPEs in the matching range that *don't*
1145 	 * have the same value as the corresponding DLTs
1146 	 * because, for some reason, not all OSes have the
1147 	 * same value for that DLT.
1148 	 */
1149 	if (linktype == LINKTYPE_PFSYNC)
1150 		return (DLT_PFSYNC);
1151 	if (linktype == LINKTYPE_PKTAP)
1152 		return (DLT_PKTAP);
1153 
1154 	/*
1155 	 * For all other values in the matching range, the LINKTYPE
1156 	 * value is the same as the DLT value.
1157 	 */
1158 	if (linktype >= LINKTYPE_MATCHING_MIN &&
1159 	    linktype <= LINKTYPE_MATCHING_MAX)
1160 		return (linktype);
1161 
1162 	/*
1163 	 * Map the values outside that range.
1164 	 */
1165 	for (i = 0; map[i].linktype != -1; i++) {
1166 		if (map[i].linktype == linktype)
1167 			return (map[i].dlt);
1168 	}
1169 
1170 	/*
1171 	 * If we don't have an entry for this LINKTYPE, return
1172 	 * the link type value; it may be a DLT from an older
1173 	 * version of libpcap.
1174 	 */
1175 	return linktype;
1176 }
1177 
1178 #define EXTRACT_
1179 
1180 /*
1181  * DLT_LINUX_SLL packets with a protocol type of LINUX_SLL_P_CAN or
1182  * LINUX_SLL_P_CANFD have SocketCAN headers in front of the payload,
1183  * with the CAN ID being in host byte order.
1184  *
1185  * When reading a DLT_LINUX_SLL capture file, we need to check for those
1186  * packets and convert the CAN ID from the byte order of the host that
1187  * wrote the file to this host's byte order.
1188  */
1189 static void
1190 swap_linux_sll_header(const struct pcap_pkthdr *hdr, u_char *buf)
1191 {
1192 	u_int caplen = hdr->caplen;
1193 	u_int length = hdr->len;
1194 	struct sll_header *shdr = (struct sll_header *)buf;
1195 	u_int16_t protocol;
1196 	pcap_can_socketcan_hdr *chdr;
1197 
1198 	if (caplen < (u_int) sizeof(struct sll_header) ||
1199 	    length < (u_int) sizeof(struct sll_header)) {
1200 		/* Not enough data to have the protocol field */
1201 		return;
1202 	}
1203 
1204 	protocol = EXTRACT_16BITS(&shdr->sll_protocol);
1205 	if (protocol != LINUX_SLL_P_CAN && protocol != LINUX_SLL_P_CANFD)
1206 		return;
1207 
1208 	/*
1209 	 * SocketCAN packet; fix up the packet's header.
1210 	 */
1211 	chdr = (pcap_can_socketcan_hdr *)(buf + sizeof(struct sll_header));
1212 	if (caplen < (u_int) sizeof(struct sll_header) + sizeof(chdr->can_id) ||
1213 	    length < (u_int) sizeof(struct sll_header) + sizeof(chdr->can_id)) {
1214 		/* Not enough data to have the CAN ID */
1215 		return;
1216 	}
1217 	chdr->can_id = SWAPLONG(chdr->can_id);
1218 }
1219 
1220 /*
1221  * The DLT_USB_LINUX and DLT_USB_LINUX_MMAPPED headers are in host
1222  * byte order when capturing (it's supplied directly from a
1223  * memory-mapped buffer shared by the kernel).
1224  *
1225  * When reading a DLT_USB_LINUX or DLT_USB_LINUX_MMAPPED capture file,
1226  * we need to convert it from the byte order of the host that wrote
1227  * the file to this host's byte order.
1228  */
1229 static void
1230 swap_linux_usb_header(const struct pcap_pkthdr *hdr, u_char *buf,
1231     int header_len_64_bytes)
1232 {
1233 	pcap_usb_header_mmapped *uhdr = (pcap_usb_header_mmapped *)buf;
1234 	bpf_u_int32 offset = 0;
1235 
1236 	/*
1237 	 * "offset" is the offset *past* the field we're swapping;
1238 	 * we skip the field *before* checking to make sure
1239 	 * the captured data length includes the entire field.
1240 	 */
1241 
1242 	/*
1243 	 * The URB id is a totally opaque value; do we really need to
1244 	 * convert it to the reading host's byte order???
1245 	 */
1246 	offset += 8;			/* skip past id */
1247 	if (hdr->caplen < offset)
1248 		return;
1249 	uhdr->id = SWAPLL(uhdr->id);
1250 
1251 	offset += 4;			/* skip past various 1-byte fields */
1252 
1253 	offset += 2;			/* skip past bus_id */
1254 	if (hdr->caplen < offset)
1255 		return;
1256 	uhdr->bus_id = SWAPSHORT(uhdr->bus_id);
1257 
1258 	offset += 2;			/* skip past various 1-byte fields */
1259 
1260 	offset += 8;			/* skip past ts_sec */
1261 	if (hdr->caplen < offset)
1262 		return;
1263 	uhdr->ts_sec = SWAPLL(uhdr->ts_sec);
1264 
1265 	offset += 4;			/* skip past ts_usec */
1266 	if (hdr->caplen < offset)
1267 		return;
1268 	uhdr->ts_usec = SWAPLONG(uhdr->ts_usec);
1269 
1270 	offset += 4;			/* skip past status */
1271 	if (hdr->caplen < offset)
1272 		return;
1273 	uhdr->status = SWAPLONG(uhdr->status);
1274 
1275 	offset += 4;			/* skip past urb_len */
1276 	if (hdr->caplen < offset)
1277 		return;
1278 	uhdr->urb_len = SWAPLONG(uhdr->urb_len);
1279 
1280 	offset += 4;			/* skip past data_len */
1281 	if (hdr->caplen < offset)
1282 		return;
1283 	uhdr->data_len = SWAPLONG(uhdr->data_len);
1284 
1285 	if (uhdr->transfer_type == URB_ISOCHRONOUS) {
1286 		offset += 4;			/* skip past s.iso.error_count */
1287 		if (hdr->caplen < offset)
1288 			return;
1289 		uhdr->s.iso.error_count = SWAPLONG(uhdr->s.iso.error_count);
1290 
1291 		offset += 4;			/* skip past s.iso.numdesc */
1292 		if (hdr->caplen < offset)
1293 			return;
1294 		uhdr->s.iso.numdesc = SWAPLONG(uhdr->s.iso.numdesc);
1295 	} else
1296 		offset += 8;			/* skip USB setup header */
1297 
1298 	/*
1299 	 * With the old header, there are no isochronous descriptors
1300 	 * after the header.
1301 	 *
1302 	 * With the new header, the actual number of descriptors in
1303 	 * the header is not s.iso.numdesc, it's ndesc - only the
1304 	 * first N descriptors, for some value of N, are put into
1305 	 * the header, and ndesc is set to the actual number copied.
1306 	 * In addition, if s.iso.numdesc is negative, no descriptors
1307 	 * are captured, and ndesc is set to 0.
1308 	 */
1309 	if (header_len_64_bytes) {
1310 		/*
1311 		 * This is either the "version 1" header, with
1312 		 * 16 bytes of additional fields at the end, or
1313 		 * a "version 0" header from a memory-mapped
1314 		 * capture, with 16 bytes of zeroed-out padding
1315 		 * at the end.  Byte swap them as if this were
1316 		 * a "version 1" header.
1317 		 */
1318 		offset += 4;			/* skip past interval */
1319 		if (hdr->caplen < offset)
1320 			return;
1321 		uhdr->interval = SWAPLONG(uhdr->interval);
1322 
1323 		offset += 4;			/* skip past start_frame */
1324 		if (hdr->caplen < offset)
1325 			return;
1326 		uhdr->start_frame = SWAPLONG(uhdr->start_frame);
1327 
1328 		offset += 4;			/* skip past xfer_flags */
1329 		if (hdr->caplen < offset)
1330 			return;
1331 		uhdr->xfer_flags = SWAPLONG(uhdr->xfer_flags);
1332 
1333 		offset += 4;			/* skip past ndesc */
1334 		if (hdr->caplen < offset)
1335 			return;
1336 		uhdr->ndesc = SWAPLONG(uhdr->ndesc);
1337 
1338 		if (uhdr->transfer_type == URB_ISOCHRONOUS) {
1339 			/* swap the values in struct linux_usb_isodesc */
1340 			usb_isodesc *pisodesc;
1341 			u_int32_t i;
1342 
1343 			pisodesc = (usb_isodesc *)(void *)(buf+offset);
1344 			for (i = 0; i < uhdr->ndesc; i++) {
1345 				offset += 4;		/* skip past status */
1346 				if (hdr->caplen < offset)
1347 					return;
1348 				pisodesc->status = SWAPLONG(pisodesc->status);
1349 
1350 				offset += 4;		/* skip past offset */
1351 				if (hdr->caplen < offset)
1352 					return;
1353 				pisodesc->offset = SWAPLONG(pisodesc->offset);
1354 
1355 				offset += 4;		/* skip past len */
1356 				if (hdr->caplen < offset)
1357 					return;
1358 				pisodesc->len = SWAPLONG(pisodesc->len);
1359 
1360 				offset += 4;		/* skip past padding */
1361 
1362 				pisodesc++;
1363 			}
1364 		}
1365 	}
1366 }
1367 
1368 /*
1369  * The DLT_NFLOG "packets" have a mixture of big-endian and host-byte-order
1370  * data.  They begin with a fixed-length header with big-endian fields,
1371  * followed by a set of TLVs, where the type and length are in host
1372  * byte order but the values are either big-endian or are a raw byte
1373  * sequence that's the same regardless of the host's byte order.
1374  *
1375  * When reading a DLT_NFLOG capture file, we need to convert the type
1376  * and length values from the byte order of the host that wrote the
1377  * file to the byte order of this host.
1378  */
1379 static void
1380 swap_nflog_header(const struct pcap_pkthdr *hdr, u_char *buf)
1381 {
1382 	u_char *p = buf;
1383 	nflog_hdr_t *nfhdr = (nflog_hdr_t *)buf;
1384 	nflog_tlv_t *tlv;
1385 	u_int caplen = hdr->caplen;
1386 	u_int length = hdr->len;
1387 	u_int16_t size;
1388 
1389 	if (caplen < (u_int) sizeof(nflog_hdr_t) ||
1390 	    length < (u_int) sizeof(nflog_hdr_t)) {
1391 		/* Not enough data to have any TLVs. */
1392 		return;
1393 	}
1394 
1395 	if (nfhdr->nflog_version != 0) {
1396 		/* Unknown NFLOG version */
1397 		return;
1398 	}
1399 
1400 	length -= sizeof(nflog_hdr_t);
1401 	caplen -= sizeof(nflog_hdr_t);
1402 	p += sizeof(nflog_hdr_t);
1403 
1404 	while (caplen >= sizeof(nflog_tlv_t)) {
1405 		tlv = (nflog_tlv_t *) p;
1406 
1407 		/* Swap the type and length. */
1408 		tlv->tlv_type = SWAPSHORT(tlv->tlv_type);
1409 		tlv->tlv_length = SWAPSHORT(tlv->tlv_length);
1410 
1411 		/* Get the length of the TLV. */
1412 		size = tlv->tlv_length;
1413 		if (size % 4 != 0)
1414 			size += 4 - size % 4;
1415 
1416 		/* Is the TLV's length less than the minimum? */
1417 		if (size < sizeof(nflog_tlv_t)) {
1418 			/* Yes. Give up now. */
1419 			return;
1420 		}
1421 
1422 		/* Do we have enough data for the full TLV? */
1423 		if (caplen < size || length < size) {
1424 			/* No. */
1425 			return;
1426 		}
1427 
1428 		/* Skip over the TLV. */
1429 		length -= size;
1430 		caplen -= size;
1431 		p += size;
1432 	}
1433 }
1434 
1435 void
1436 swap_pseudo_headers(int linktype, struct pcap_pkthdr *hdr, u_char *data)
1437 {
1438 	/*
1439 	 * Convert pseudo-headers from the byte order of
1440 	 * the host on which the file was saved to our
1441 	 * byte order, as necessary.
1442 	 */
1443 	switch (linktype) {
1444 
1445 	case DLT_LINUX_SLL:
1446 		swap_linux_sll_header(hdr, data);
1447 		break;
1448 
1449 	case DLT_USB_LINUX:
1450 		swap_linux_usb_header(hdr, data, 0);
1451 		break;
1452 
1453 	case DLT_USB_LINUX_MMAPPED:
1454 		swap_linux_usb_header(hdr, data, 1);
1455 		break;
1456 
1457 	case DLT_NFLOG:
1458 		swap_nflog_header(hdr, data);
1459 		break;
1460 	}
1461 }
1462