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1 /*
2  * Copyright (c) 1994, 1995, 1996
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 the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the Computer Systems
16  *	Engineering Group at Lawrence Berkeley Laboratory.
17  * 4. Neither the name of the University nor of the Laboratory may be used
18  *    to endorse or promote products derived from this software without
19  *    specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef pcap_int_h
35 #define	pcap_int_h
36 
37 #include <stddef.h>
38 
39 #include <signal.h>
40 
41 #include <pcap/pcap.h>
42 
43 #include "varattrs.h"
44 #include "fmtutils.h"
45 
46 /*
47  * Version string.
48  * Uses PACKAGE_VERSION from config.h.
49  */
50 #define PCAP_VERSION_STRING "libpcap version " PACKAGE_VERSION
51 
52 #ifdef __cplusplus
53 extern "C" {
54 #endif
55 
56 /*
57  * If pcap_new_api is set, we disable pcap_lookupdev(), because:
58  *
59  *    it's not thread-safe, and is marked as deprecated, on all
60  *    platforms;
61  *
62  *    on Windows, it may return UTF-16LE strings, which the program
63  *    might then pass to pcap_create() (or to pcap_open_live(), which
64  *    then passes them to pcap_create()), requiring pcap_create() to
65  *    check for UTF-16LE strings using a hack, and that hack 1)
66  *    *cannot* be 100% reliable and 2) runs the risk of going past the
67  *    end of the string.
68  *
69  * We keep it around in legacy mode for compatibility.
70  *
71  * We also disable the aforementioned hack in pcap_create().
72  */
73 extern int pcap_new_api;
74 
75 /*
76  * If pcap_utf_8_mode is set, on Windows we treat strings as UTF-8.
77  *
78  * On UN*Xes, we assume all strings are and should be in UTF-8, regardless
79  * of the setting of this flag.
80  */
81 extern int pcap_utf_8_mode;
82 
83 #ifdef MSDOS
84   #include <fcntl.h>
85   #include <io.h>
86 #endif
87 
88 /*
89  * Swap byte ordering of unsigned long long timestamp on a big endian
90  * machine.
91  */
92 #define SWAPLL(ull)  ((ull & 0xff00000000000000ULL) >> 56) | \
93                       ((ull & 0x00ff000000000000ULL) >> 40) | \
94                       ((ull & 0x0000ff0000000000ULL) >> 24) | \
95                       ((ull & 0x000000ff00000000ULL) >> 8)  | \
96                       ((ull & 0x00000000ff000000ULL) << 8)  | \
97                       ((ull & 0x0000000000ff0000ULL) << 24) | \
98                       ((ull & 0x000000000000ff00ULL) << 40) | \
99                       ((ull & 0x00000000000000ffULL) << 56)
100 
101 /*
102  * Maximum snapshot length.
103  *
104  * Somewhat arbitrary, but chosen to be:
105  *
106  *    1) big enough for maximum-size Linux loopback packets (65549)
107  *       and some USB packets captured with USBPcap:
108  *
109  *           https://desowin.org/usbpcap/
110  *
111  *       (> 131072, < 262144)
112  *
113  * and
114  *
115  *    2) small enough not to cause attempts to allocate huge amounts of
116  *       memory; some applications might use the snapshot length in a
117  *       savefile header to control the size of the buffer they allocate,
118  *       so a size of, say, 2^31-1 might not work well.  (libpcap uses it
119  *       as a hint, but doesn't start out allocating a buffer bigger than
120  *       2 KiB, and grows the buffer as necessary, but not beyond the
121  *       per-linktype maximum snapshot length.  Other code might naively
122  *       use it; we want to avoid writing a too-large snapshot length,
123  *       in order not to cause that code problems.)
124  *
125  * We don't enforce this in pcap_set_snaplen(), but we use it internally.
126  */
127 #define MAXIMUM_SNAPLEN		262144
128 
129 /*
130  * Locale-independent macros for testing character types.
131  * These can be passed any integral value, without worrying about, for
132  * example, sign-extending char values, unlike the C macros.
133  */
134 #define PCAP_ISDIGIT(c) \
135 	((c) >= '0' && (c) <= '9')
136 #define PCAP_ISXDIGIT(c) \
137 	(((c) >= '0' && (c) <= '9') || \
138 	 ((c) >= 'A' && (c) <= 'F') || \
139 	 ((c) >= 'a' && (c) <= 'f'))
140 
141 struct pcap_opt {
142 	char	*device;
143 	int	timeout;	/* timeout for buffering */
144 	u_int	buffer_size;
145 	int	promisc;
146 	int	rfmon;		/* monitor mode */
147 	int	immediate;	/* immediate mode - deliver packets as soon as they arrive */
148 	int	nonblock;	/* non-blocking mode - don't wait for packets to be delivered, return "no packets available" */
149 	int	tstamp_type;
150 	int	tstamp_precision;
151 
152 	/*
153 	 * Platform-dependent options.
154 	 */
155 #ifdef __linux__
156 	int	protocol;	/* protocol to use when creating PF_PACKET socket */
157 #endif
158 #ifdef _WIN32
159 	int	nocapture_local;/* disable NPF loopback */
160 #endif
161 };
162 
163 typedef int	(*activate_op_t)(pcap_t *);
164 typedef int	(*can_set_rfmon_op_t)(pcap_t *);
165 typedef int	(*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *);
166 typedef int	(*next_packet_op_t)(pcap_t *, struct pcap_pkthdr *, u_char **);
167 typedef int	(*inject_op_t)(pcap_t *, const void *, int);
168 typedef void	(*save_current_filter_op_t)(pcap_t *, const char *);
169 typedef int	(*setfilter_op_t)(pcap_t *, struct bpf_program *);
170 typedef int	(*setdirection_op_t)(pcap_t *, pcap_direction_t);
171 typedef int	(*set_datalink_op_t)(pcap_t *, int);
172 typedef int	(*getnonblock_op_t)(pcap_t *);
173 typedef int	(*setnonblock_op_t)(pcap_t *, int);
174 typedef int	(*stats_op_t)(pcap_t *, struct pcap_stat *);
175 typedef void	(*breakloop_op_t)(pcap_t *);
176 #ifdef _WIN32
177 typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *);
178 typedef int	(*setbuff_op_t)(pcap_t *, int);
179 typedef int	(*setmode_op_t)(pcap_t *, int);
180 typedef int	(*setmintocopy_op_t)(pcap_t *, int);
181 typedef HANDLE	(*getevent_op_t)(pcap_t *);
182 typedef int	(*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *);
183 typedef int	(*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *);
184 typedef u_int	(*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int);
185 typedef int	(*setuserbuffer_op_t)(pcap_t *, int);
186 typedef int	(*live_dump_op_t)(pcap_t *, char *, int, int);
187 typedef int	(*live_dump_ended_op_t)(pcap_t *, int);
188 typedef PAirpcapHandle	(*get_airpcap_handle_op_t)(pcap_t *);
189 #endif
190 typedef void	(*cleanup_op_t)(pcap_t *);
191 
192 /*
193  * We put all the stuff used in the read code path at the beginning,
194  * to try to keep it together in the same cache line or lines.
195  */
196 struct pcap {
197 	/*
198 	 * Method to call to read packets on a live capture.
199 	 */
200 	read_op_t read_op;
201 
202 	/*
203 	 * Method to call to read the next packet from a savefile.
204 	 */
205 	next_packet_op_t next_packet_op;
206 
207 #ifdef _WIN32
208 	HANDLE handle;
209 #else
210 	int fd;
211 #endif /* _WIN32 */
212 
213 	/*
214 	 * Read buffer.
215 	 */
216 	u_int bufsize;
217 	void *buffer;
218 	u_char *bp;
219 	int cc;
220 
221 	sig_atomic_t break_loop; /* flag set to force break from packet-reading loop */
222 
223 	void *priv;		/* private data for methods */
224 
225 #ifdef ENABLE_REMOTE
226 	struct pcap_samp rmt_samp;	/* parameters related to the sampling process. */
227 #endif
228 
229 	int swapped;
230 	FILE *rfile;		/* null if live capture, non-null if savefile */
231 	u_int fddipad;
232 	struct pcap *next;	/* list of open pcaps that need stuff cleared on close */
233 
234 	/*
235 	 * File version number; meaningful only for a savefile, but we
236 	 * keep it here so that apps that (mistakenly) ask for the
237 	 * version numbers will get the same zero values that they
238 	 * always did.
239 	 */
240 	int version_major;
241 	int version_minor;
242 
243 	int snapshot;
244 	int linktype;		/* Network linktype */
245 	int linktype_ext;	/* Extended information stored in the linktype field of a file */
246 	int offset;		/* offset for proper alignment */
247 	int activated;		/* true if the capture is really started */
248 	int oldstyle;		/* if we're opening with pcap_open_live() */
249 
250 	struct pcap_opt opt;
251 
252 	/*
253 	 * Place holder for pcap_next().
254 	 */
255 	u_char *pkt;
256 
257 #ifdef _WIN32
258 	struct pcap_stat stat;	/* used for pcap_stats_ex() */
259 #endif
260 
261 	/* We're accepting only packets in this direction/these directions. */
262 	pcap_direction_t direction;
263 
264 	/*
265 	 * Flags to affect BPF code generation.
266 	 */
267 	int bpf_codegen_flags;
268 
269 #if !defined(_WIN32) && !defined(MSDOS)
270 	int selectable_fd;	/* FD on which select()/poll()/epoll_wait()/kevent()/etc. can be done */
271 
272 	/*
273 	 * In case there either is no selectable FD, or there is but
274 	 * it doesn't necessarily work (e.g., if it doesn't get notified
275 	 * if the packet capture timeout expires before the buffer
276 	 * fills up), this points to a timeout that should be used
277 	 * in select()/poll()/epoll_wait()/kevent() call.  The pcap_t should
278 	 * be put into non-blocking mode, and, if the timeout expires on
279 	 * the call, an attempt should be made to read packets from all
280 	 * pcap_t's with a required timeout, and the code must be
281 	 * prepared not to see any packets from the attempt.
282 	 */
283 	const struct timeval *required_select_timeout;
284 #endif
285 
286 	/*
287 	 * Placeholder for filter code if bpf not in kernel.
288 	 */
289 	struct bpf_program fcode;
290 
291 	char errbuf[PCAP_ERRBUF_SIZE + 1];
292 #ifdef _WIN32
293 	char acp_errbuf[PCAP_ERRBUF_SIZE + 1];	/* buffer for local code page error strings */
294 #endif
295 	int dlt_count;
296 	u_int *dlt_list;
297 	int tstamp_type_count;
298 	u_int *tstamp_type_list;
299 	int tstamp_precision_count;
300 	u_int *tstamp_precision_list;
301 
302 	struct pcap_pkthdr pcap_header;	/* This is needed for the pcap_next_ex() to work */
303 
304 	/*
305 	 * More methods.
306 	 */
307 	activate_op_t activate_op;
308 	can_set_rfmon_op_t can_set_rfmon_op;
309 	inject_op_t inject_op;
310 	save_current_filter_op_t save_current_filter_op;
311 	setfilter_op_t setfilter_op;
312 	setdirection_op_t setdirection_op;
313 	set_datalink_op_t set_datalink_op;
314 	getnonblock_op_t getnonblock_op;
315 	setnonblock_op_t setnonblock_op;
316 	stats_op_t stats_op;
317 	breakloop_op_t breakloop_op;
318 
319 	/*
320 	 * Routine to use as callback for pcap_next()/pcap_next_ex().
321 	 */
322 	pcap_handler oneshot_callback;
323 
324 #ifdef _WIN32
325 	/*
326 	 * These are, at least currently, specific to the Win32 NPF
327 	 * driver.
328 	 */
329 	stats_ex_op_t stats_ex_op;
330 	setbuff_op_t setbuff_op;
331 	setmode_op_t setmode_op;
332 	setmintocopy_op_t setmintocopy_op;
333 	getevent_op_t getevent_op;
334 	oid_get_request_op_t oid_get_request_op;
335 	oid_set_request_op_t oid_set_request_op;
336 	sendqueue_transmit_op_t sendqueue_transmit_op;
337 	setuserbuffer_op_t setuserbuffer_op;
338 	live_dump_op_t live_dump_op;
339 	live_dump_ended_op_t live_dump_ended_op;
340 	get_airpcap_handle_op_t get_airpcap_handle_op;
341 #endif
342 	cleanup_op_t cleanup_op;
343 };
344 
345 /*
346  * BPF code generation flags.
347  */
348 #define BPF_SPECIAL_VLAN_HANDLING	0x00000001	/* special VLAN handling for Linux */
349 
350 /*
351  * This is a timeval as stored in a savefile.
352  * It has to use the same types everywhere, independent of the actual
353  * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
354  * platforms and 64-bit tv_sec values on other platforms, and writing
355  * out native `struct timeval' values would mean files could only be
356  * read on systems with the same tv_sec size as the system on which
357  * the file was written.
358  */
359 
360 struct pcap_timeval {
361     bpf_int32 tv_sec;		/* seconds */
362     bpf_int32 tv_usec;		/* microseconds */
363 };
364 
365 /*
366  * This is a `pcap_pkthdr' as actually stored in a savefile.
367  *
368  * Do not change the format of this structure, in any way (this includes
369  * changes that only affect the length of fields in this structure),
370  * and do not make the time stamp anything other than seconds and
371  * microseconds (e.g., seconds and nanoseconds).  Instead:
372  *
373  *	introduce a new structure for the new format;
374  *
375  *	send mail to "tcpdump-workers@lists.tcpdump.org", requesting
376  *	a new magic number for your new capture file format, and, when
377  *	you get the new magic number, put it in "savefile.c";
378  *
379  *	use that magic number for save files with the changed record
380  *	header;
381  *
382  *	make the code in "savefile.c" capable of reading files with
383  *	the old record header as well as files with the new record header
384  *	(using the magic number to determine the header format).
385  *
386  * Then supply the changes by forking the branch at
387  *
388  *	https://github.com/the-tcpdump-group/libpcap/tree/master
389  *
390  * and issuing a pull request, so that future versions of libpcap and
391  * programs that use it (such as tcpdump) will be able to read your new
392  * capture file format.
393  */
394 
395 struct pcap_sf_pkthdr {
396     struct pcap_timeval ts;	/* time stamp */
397     bpf_u_int32 caplen;		/* length of portion present */
398     bpf_u_int32 len;		/* length of this packet (off wire) */
399 };
400 
401 /*
402  * How a `pcap_pkthdr' is actually stored in savefiles written
403  * by some patched versions of libpcap (e.g. the ones in Red
404  * Hat Linux 6.1 and 6.2).
405  *
406  * Do not change the format of this structure, in any way (this includes
407  * changes that only affect the length of fields in this structure).
408  * Instead, introduce a new structure, as per the above.
409  */
410 
411 struct pcap_sf_patched_pkthdr {
412     struct pcap_timeval ts;	/* time stamp */
413     bpf_u_int32 caplen;		/* length of portion present */
414     bpf_u_int32 len;		/* length of this packet (off wire) */
415     int		index;
416     unsigned short protocol;
417     unsigned char pkt_type;
418 };
419 
420 /*
421  * User data structure for the one-shot callback used for pcap_next()
422  * and pcap_next_ex().
423  */
424 struct oneshot_userdata {
425 	struct pcap_pkthdr *hdr;
426 	const u_char **pkt;
427 	pcap_t *pd;
428 };
429 
430 #ifndef min
431 #define min(a, b) ((a) > (b) ? (b) : (a))
432 #endif
433 
434 int	pcap_offline_read(pcap_t *, int, pcap_handler, u_char *);
435 
436 #include <stdarg.h>
437 
438 #include "portability.h"
439 
440 /*
441  * Does the packet count argument to a module's read routine say
442  * "supply packets until you run out of packets"?
443  */
444 #define PACKET_COUNT_IS_UNLIMITED(count)	((count) <= 0)
445 
446 /*
447  * Routines that most pcap implementations can use for non-blocking mode.
448  */
449 #if !defined(_WIN32) && !defined(MSDOS)
450 int	pcap_getnonblock_fd(pcap_t *);
451 int	pcap_setnonblock_fd(pcap_t *p, int);
452 #endif
453 
454 /*
455  * Internal interfaces for "pcap_create()".
456  *
457  * "pcap_create_interface()" is the routine to do a pcap_create on
458  * a regular network interface.  There are multiple implementations
459  * of this, one for each platform type (Linux, BPF, DLPI, etc.),
460  * with the one used chosen by the configure script.
461  *
462  * "pcap_create_common()" allocates and fills in a pcap_t, for use
463  * by pcap_create routines.
464  */
465 pcap_t	*pcap_create_interface(const char *, char *);
466 
467 /*
468  * This wrapper takes an error buffer pointer and a type to use for the
469  * private data, and calls pcap_create_common(), passing it the error
470  * buffer pointer, the size fo the private data type, in bytes, and the
471  * offset of the private data from the beginning of the structure, in
472  * bytes.
473  */
474 #define PCAP_CREATE_COMMON(ebuf, type) \
475 	pcap_create_common(ebuf, \
476 	    sizeof (struct { pcap_t __common; type __private; }), \
477 	    offsetof (struct { pcap_t __common; type __private; }, __private))
478 pcap_t	*pcap_create_common(char *, size_t, size_t);
479 int	pcap_do_addexit(pcap_t *);
480 void	pcap_add_to_pcaps_to_close(pcap_t *);
481 void	pcap_remove_from_pcaps_to_close(pcap_t *);
482 void	pcap_cleanup_live_common(pcap_t *);
483 int	pcap_check_activated(pcap_t *);
484 void	pcap_breakloop_common(pcap_t *);
485 
486 /*
487  * Internal interfaces for "pcap_findalldevs()".
488  *
489  * A pcap_if_list_t * is a reference to a list of devices.
490  *
491  * A get_if_flags_func is a platform-dependent function called to get
492  * additional interface flags.
493  *
494  * "pcap_platform_finddevs()" is the platform-dependent routine to
495  * find local network interfaces.
496  *
497  * "pcap_findalldevs_interfaces()" is a helper to find those interfaces
498  * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
499  *
500  * "add_dev()" adds an entry to a pcap_if_list_t.
501  *
502  * "find_dev()" tries to find a device, by name, in a pcap_if_list_t.
503  *
504  * "find_or_add_dev()" checks whether a device is already in a pcap_if_list_t
505  * and, if not, adds an entry for it.
506  */
507 struct pcap_if_list;
508 typedef struct pcap_if_list pcap_if_list_t;
509 typedef int (*get_if_flags_func)(const char *, bpf_u_int32 *, char *);
510 int	pcap_platform_finddevs(pcap_if_list_t *, char *);
511 #if !defined(_WIN32) && !defined(MSDOS)
512 int	pcap_findalldevs_interfaces(pcap_if_list_t *, char *,
513 	    int (*)(const char *), get_if_flags_func);
514 #endif
515 pcap_if_t *find_or_add_dev(pcap_if_list_t *, const char *, bpf_u_int32,
516 	    get_if_flags_func, const char *, char *);
517 pcap_if_t *find_dev(pcap_if_list_t *, const char *);
518 pcap_if_t *add_dev(pcap_if_list_t *, const char *, bpf_u_int32, const char *,
519 	    char *);
520 int	add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t,
521 	    struct sockaddr *, size_t, struct sockaddr *, size_t,
522 	    struct sockaddr *dstaddr, size_t, char *errbuf);
523 #ifndef _WIN32
524 pcap_if_t *find_or_add_if(pcap_if_list_t *, const char *, bpf_u_int32,
525 	    get_if_flags_func, char *);
526 int	add_addr_to_if(pcap_if_list_t *, const char *, bpf_u_int32,
527 	    get_if_flags_func,
528 	    struct sockaddr *, size_t, struct sockaddr *, size_t,
529 	    struct sockaddr *, size_t, struct sockaddr *, size_t, char *);
530 #endif
531 
532 /*
533  * Internal interfaces for "pcap_open_offline()" and other savefile
534  * I/O routines.
535  *
536  * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
537  * by pcap_open_offline routines.
538  *
539  * "pcap_adjust_snapshot()" adjusts the snapshot to be non-zero and
540  * fit within an int.
541  *
542  * "sf_cleanup()" closes the file handle associated with a pcap_t, if
543  * appropriate, and frees all data common to all modules for handling
544  * savefile types.
545  *
546  * "charset_fopen()", in UTF-8 mode on Windows, does an fopen() that
547  * treats the pathname as being in UTF-8, rather than the local
548  * code page, on Windows.
549  */
550 
551 /*
552  * This wrapper takes an error buffer pointer and a type to use for the
553  * private data, and calls pcap_create_common(), passing it the error
554  * buffer pointer, the size fo the private data type, in bytes, and the
555  * offset of the private data from the beginning of the structure, in
556  * bytes.
557  */
558 #define PCAP_OPEN_OFFLINE_COMMON(ebuf, type) \
559 	pcap_open_offline_common(ebuf, \
560 	    sizeof (struct { pcap_t __common; type __private; }), \
561 	    offsetof (struct { pcap_t __common; type __private; }, __private))
562 pcap_t	*pcap_open_offline_common(char *ebuf, size_t total_size,
563     size_t private_data);
564 bpf_u_int32 pcap_adjust_snapshot(bpf_u_int32 linktype, bpf_u_int32 snaplen);
565 void	sf_cleanup(pcap_t *p);
566 #ifdef _WIN32
567 FILE	*charset_fopen(const char *path, const char *mode);
568 #else
569 /*
570  * On other OSes, just use Boring Old fopen().
571  */
572 #define charset_fopen(path, mode)	fopen((path), (mode))
573 #endif
574 
575 /*
576  * Internal interfaces for loading code at run time.
577  */
578 #ifdef _WIN32
579 #define pcap_code_handle_t	HMODULE
580 #define pcap_funcptr_t		FARPROC
581 
582 pcap_code_handle_t	pcap_load_code(const char *);
583 pcap_funcptr_t		pcap_find_function(pcap_code_handle_t, const char *);
584 #endif
585 
586 /*
587  * Internal interfaces for doing user-mode filtering of packets and
588  * validating filter programs.
589  */
590 /*
591  * Auxiliary data, for use when interpreting a filter intended for the
592  * Linux kernel when the kernel rejects the filter (requiring us to
593  * run it in userland).  It contains VLAN tag information.
594  */
595 struct bpf_aux_data {
596 	u_short vlan_tag_present;
597 	u_short vlan_tag;
598 };
599 
600 /*
601  * Filtering routine that takes the auxiliary data as an additional
602  * argument.
603  */
604 u_int	pcap_filter_with_aux_data(const struct bpf_insn *,
605     const u_char *, u_int, u_int, const struct bpf_aux_data *);
606 
607 /*
608  * Filtering routine that doesn't.
609  */
610 u_int	pcap_filter(const struct bpf_insn *, const u_char *, u_int, u_int);
611 
612 /*
613  * Routine to validate a BPF program.
614  */
615 int	pcap_validate_filter(const struct bpf_insn *, int);
616 
617 /*
618  * Internal interfaces for both "pcap_create()" and routines that
619  * open savefiles.
620  *
621  * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
622  * and "pcap_next_ex()".
623  */
624 void	pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *);
625 
626 int	install_bpf_program(pcap_t *, struct bpf_program *);
627 
628 int	pcap_strcasecmp(const char *, const char *);
629 
630 /*
631  * Internal interfaces for pcap_createsrcstr and pcap_parsesrcstr with
632  * the additional bit of information regarding SSL support (rpcap:// vs.
633  * rpcaps://).
634  */
635 int	pcap_createsrcstr_ex(char *, int, const char *, const char *,
636     const char *, unsigned char, char *);
637 int	pcap_parsesrcstr_ex(const char *, int *, char *, char *,
638     char *, unsigned char *, char *);
639 
640 #ifdef YYDEBUG
641 extern int pcap_debug;
642 #endif
643 
644 #ifdef __cplusplus
645 }
646 #endif
647 
648 #endif
649