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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 <pcap/pcap.h>
38 
39 #ifdef __cplusplus
40 extern "C" {
41 #endif
42 
43 #if defined(_WIN32)
44   /*
45    * Make sure Packet32.h doesn't define BPF structures that we've
46    * probably already defined as a result of including <pcap/pcap.h>.
47    */
48   #define BPF_MAJOR_VERSION
49   #include <Packet32.h>
50 #elif defined(MSDOS)
51   #include <fcntl.h>
52   #include <io.h>
53 #endif
54 
55 #if (defined(_MSC_VER) && (_MSC_VER <= 1200)) /* we are compiling with Visual Studio 6, that doesn't support the LL suffix*/
56 
57 /*
58  * Swap byte ordering of unsigned long long timestamp on a big endian
59  * machine.
60  */
61 #define SWAPLL(ull)  ((ull & 0xff00000000000000) >> 56) | \
62                       ((ull & 0x00ff000000000000) >> 40) | \
63                       ((ull & 0x0000ff0000000000) >> 24) | \
64                       ((ull & 0x000000ff00000000) >> 8)  | \
65                       ((ull & 0x00000000ff000000) << 8)  | \
66                       ((ull & 0x0000000000ff0000) << 24) | \
67                       ((ull & 0x000000000000ff00) << 40) | \
68                       ((ull & 0x00000000000000ff) << 56)
69 
70 #else /* A recent Visual studio compiler or not VC */
71 
72 /*
73  * Swap byte ordering of unsigned long long timestamp on a big endian
74  * machine.
75  */
76 #define SWAPLL(ull)  ((ull & 0xff00000000000000LL) >> 56) | \
77                       ((ull & 0x00ff000000000000LL) >> 40) | \
78                       ((ull & 0x0000ff0000000000LL) >> 24) | \
79                       ((ull & 0x000000ff00000000LL) >> 8)  | \
80                       ((ull & 0x00000000ff000000LL) << 8)  | \
81                       ((ull & 0x0000000000ff0000LL) << 24) | \
82                       ((ull & 0x000000000000ff00LL) << 40) | \
83                       ((ull & 0x00000000000000ffLL) << 56)
84 
85 #endif /* _MSC_VER */
86 
87 /*
88  * Maximum snapshot length.
89  *
90  * Somewhat arbitrary, but chosen to be:
91  *
92  *    1) big enough for maximum-size Linux loopback packets (65549)
93  *       and some USB packets captured with USBPcap:
94  *
95  *           http://desowin.org/usbpcap/
96  *
97  *       (> 131072, < 262144)
98  *
99  * and
100  *
101  *    2) small enough not to cause attempts to allocate huge amounts of
102  *       memory; some applications might use the snapshot length in a
103  *       savefile header to control the size of the buffer they allocate,
104  *       so a size of, say, 2^31-1 might not work well.
105  *
106  * We don't enforce this in pcap_set_snaplen(), but we use it internally.
107  */
108 #define MAXIMUM_SNAPLEN		262144
109 
110 struct pcap_opt {
111 	char	*device;
112 	int	timeout;	/* timeout for buffering */
113 	u_int	buffer_size;
114 	int	promisc;
115 	int	rfmon;		/* monitor mode */
116 	int	immediate;	/* immediate mode - deliver packets as soon as they arrive */
117 	int	tstamp_type;
118 	int	tstamp_precision;
119 };
120 
121 typedef int	(*activate_op_t)(pcap_t *);
122 typedef int	(*can_set_rfmon_op_t)(pcap_t *);
123 typedef int	(*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *);
124 typedef int	(*inject_op_t)(pcap_t *, const void *, size_t);
125 typedef int	(*setfilter_op_t)(pcap_t *, struct bpf_program *);
126 typedef int	(*setdirection_op_t)(pcap_t *, pcap_direction_t);
127 typedef int	(*set_datalink_op_t)(pcap_t *, int);
128 typedef int	(*getnonblock_op_t)(pcap_t *, char *);
129 typedef int	(*setnonblock_op_t)(pcap_t *, int, char *);
130 typedef int	(*stats_op_t)(pcap_t *, struct pcap_stat *);
131 #ifdef _WIN32
132 typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *);
133 typedef int	(*setbuff_op_t)(pcap_t *, int);
134 typedef int	(*setmode_op_t)(pcap_t *, int);
135 typedef int	(*setmintocopy_op_t)(pcap_t *, int);
136 typedef HANDLE	(*getevent_op_t)(pcap_t *);
137 typedef int	(*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *);
138 typedef int	(*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *);
139 typedef u_int	(*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int);
140 typedef int	(*setuserbuffer_op_t)(pcap_t *, int);
141 typedef int	(*live_dump_op_t)(pcap_t *, char *, int, int);
142 typedef int	(*live_dump_ended_op_t)(pcap_t *, int);
143 typedef PAirpcapHandle	(*get_airpcap_handle_op_t)(pcap_t *);
144 #endif
145 typedef void	(*cleanup_op_t)(pcap_t *);
146 
147 /*
148  * We put all the stuff used in the read code path at the beginning,
149  * to try to keep it together in the same cache line or lines.
150  */
151 struct pcap {
152 	/*
153 	 * Method to call to read packets on a live capture.
154 	 */
155 	read_op_t read_op;
156 
157 	/*
158 	 * Method to call to read packets from a savefile.
159 	 */
160 	int (*next_packet_op)(pcap_t *, struct pcap_pkthdr *, u_char **);
161 
162 #ifdef _WIN32
163 	ADAPTER *adapter;
164 #else
165 	int fd;
166 	int selectable_fd;
167 #endif /* _WIN32 */
168 
169 	/*
170 	 * Read buffer.
171 	 */
172 	u_int bufsize;
173 	void *buffer;
174 	u_char *bp;
175 	int cc;
176 
177 	int break_loop;		/* flag set to force break from packet-reading loop */
178 
179 	void *priv;		/* private data for methods */
180 
181 	int swapped;
182 	FILE *rfile;		/* null if live capture, non-null if savefile */
183 	u_int fddipad;
184 	struct pcap *next;	/* list of open pcaps that need stuff cleared on close */
185 
186 	/*
187 	 * File version number; meaningful only for a savefile, but we
188 	 * keep it here so that apps that (mistakenly) ask for the
189 	 * version numbers will get the same zero values that they
190 	 * always did.
191 	 */
192 	int version_major;
193 	int version_minor;
194 
195 	int snapshot;
196 	int linktype;		/* Network linktype */
197 	int linktype_ext;       /* Extended information stored in the linktype field of a file */
198 	int tzoff;		/* timezone offset */
199 	int offset;		/* offset for proper alignment */
200 	int activated;		/* true if the capture is really started */
201 	int oldstyle;		/* if we're opening with pcap_open_live() */
202 
203 	struct pcap_opt opt;
204 
205 	/*
206 	 * Place holder for pcap_next().
207 	 */
208 	u_char *pkt;
209 
210 #ifdef _WIN32
211 	struct pcap_stat stat;		/* used for pcap_stats_ex() */
212 #endif
213 
214 	/* We're accepting only packets in this direction/these directions. */
215 	pcap_direction_t direction;
216 
217 	/*
218 	 * Flags to affect BPF code generation.
219 	 */
220 	int bpf_codegen_flags;
221 
222 	/*
223 	 * Placeholder for filter code if bpf not in kernel.
224 	 */
225 	struct bpf_program fcode;
226 
227 	char errbuf[PCAP_ERRBUF_SIZE + 1];
228 	int dlt_count;
229 	u_int *dlt_list;
230 	int tstamp_type_count;
231 	u_int *tstamp_type_list;
232 	int tstamp_precision_count;
233 	u_int *tstamp_precision_list;
234 
235 	struct pcap_pkthdr pcap_header;	/* This is needed for the pcap_next_ex() to work */
236 
237 	/*
238 	 * More methods.
239 	 */
240 	activate_op_t activate_op;
241 	can_set_rfmon_op_t can_set_rfmon_op;
242 	inject_op_t inject_op;
243 	setfilter_op_t setfilter_op;
244 	setdirection_op_t setdirection_op;
245 	set_datalink_op_t set_datalink_op;
246 	getnonblock_op_t getnonblock_op;
247 	setnonblock_op_t setnonblock_op;
248 	stats_op_t stats_op;
249 
250 	/*
251 	 * Routine to use as callback for pcap_next()/pcap_next_ex().
252 	 */
253 	pcap_handler oneshot_callback;
254 
255 #ifdef _WIN32
256 	/*
257 	 * These are, at least currently, specific to the Win32 NPF
258 	 * driver.
259 	 */
260 	stats_ex_op_t stats_ex_op;
261 	setbuff_op_t setbuff_op;
262 	setmode_op_t setmode_op;
263 	setmintocopy_op_t setmintocopy_op;
264 	getevent_op_t getevent_op;
265 	oid_get_request_op_t oid_get_request_op;
266 	oid_set_request_op_t oid_set_request_op;
267 	sendqueue_transmit_op_t sendqueue_transmit_op;
268 	setuserbuffer_op_t setuserbuffer_op;
269 	live_dump_op_t live_dump_op;
270 	live_dump_ended_op_t live_dump_ended_op;
271 	get_airpcap_handle_op_t get_airpcap_handle_op;
272 #endif
273 	cleanup_op_t cleanup_op;
274 };
275 
276 /*
277  * BPF code generation flags.
278  */
279 #define BPF_SPECIAL_VLAN_HANDLING	0x00000001	/* special VLAN handling for Linux */
280 
281 /*
282  * This is a timeval as stored in a savefile.
283  * It has to use the same types everywhere, independent of the actual
284  * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
285  * platforms and 64-bit tv_sec values on other platforms, and writing
286  * out native `struct timeval' values would mean files could only be
287  * read on systems with the same tv_sec size as the system on which
288  * the file was written.
289  */
290 
291 struct pcap_timeval {
292     bpf_int32 tv_sec;		/* seconds */
293     bpf_int32 tv_usec;		/* microseconds */
294 };
295 
296 /*
297  * This is a `pcap_pkthdr' as actually stored in a savefile.
298  *
299  * Do not change the format of this structure, in any way (this includes
300  * changes that only affect the length of fields in this structure),
301  * and do not make the time stamp anything other than seconds and
302  * microseconds (e.g., seconds and nanoseconds).  Instead:
303  *
304  *	introduce a new structure for the new format;
305  *
306  *	send mail to "tcpdump-workers@lists.tcpdump.org", requesting
307  *	a new magic number for your new capture file format, and, when
308  *	you get the new magic number, put it in "savefile.c";
309  *
310  *	use that magic number for save files with the changed record
311  *	header;
312  *
313  *	make the code in "savefile.c" capable of reading files with
314  *	the old record header as well as files with the new record header
315  *	(using the magic number to determine the header format).
316  *
317  * Then supply the changes by forking the branch at
318  *
319  *	https://github.com/the-tcpdump-group/libpcap/issues
320  *
321  * and issuing a pull request, so that future versions of libpcap and
322  * programs that use it (such as tcpdump) will be able to read your new
323  * capture file format.
324  */
325 
326 struct pcap_sf_pkthdr {
327     struct pcap_timeval ts;	/* time stamp */
328     bpf_u_int32 caplen;		/* length of portion present */
329     bpf_u_int32 len;		/* length this packet (off wire) */
330 };
331 
332 /*
333  * How a `pcap_pkthdr' is actually stored in savefiles written
334  * by some patched versions of libpcap (e.g. the ones in Red
335  * Hat Linux 6.1 and 6.2).
336  *
337  * Do not change the format of this structure, in any way (this includes
338  * changes that only affect the length of fields in this structure).
339  * Instead, introduce a new structure, as per the above.
340  */
341 
342 struct pcap_sf_patched_pkthdr {
343     struct pcap_timeval ts;	/* time stamp */
344     bpf_u_int32 caplen;		/* length of portion present */
345     bpf_u_int32 len;		/* length this packet (off wire) */
346     int		index;
347     unsigned short protocol;
348     unsigned char pkt_type;
349 };
350 
351 /*
352  * User data structure for the one-shot callback used for pcap_next()
353  * and pcap_next_ex().
354  */
355 struct oneshot_userdata {
356 	struct pcap_pkthdr *hdr;
357 	const u_char **pkt;
358 	pcap_t *pd;
359 };
360 
361 #ifndef min
362 #define min(a, b) ((a) > (b) ? (b) : (a))
363 #endif
364 
365 int	pcap_offline_read(pcap_t *, int, pcap_handler, u_char *);
366 
367 #include <stdarg.h>
368 
369 #include "portability.h"
370 
371 /*
372  * Does the packet count argument to a module's read routine say
373  * "supply packets until you run out of packets"?
374  */
375 #define PACKET_COUNT_IS_UNLIMITED(count)	((count) <= 0)
376 
377 /*
378  * Routines that most pcap implementations can use for non-blocking mode.
379  */
380 #if !defined(_WIN32) && !defined(MSDOS)
381 int	pcap_getnonblock_fd(pcap_t *, char *);
382 int	pcap_setnonblock_fd(pcap_t *p, int, char *);
383 #endif
384 
385 /*
386  * Internal interfaces for "pcap_create()".
387  *
388  * "pcap_create_interface()" is the routine to do a pcap_create on
389  * a regular network interface.  There are multiple implementations
390  * of this, one for each platform type (Linux, BPF, DLPI, etc.),
391  * with the one used chosen by the configure script.
392  *
393  * "pcap_create_common()" allocates and fills in a pcap_t, for use
394  * by pcap_create routines.
395  */
396 pcap_t	*pcap_create_interface(const char *, char *);
397 pcap_t	*pcap_create_common(char *, size_t);
398 int	pcap_do_addexit(pcap_t *);
399 void	pcap_add_to_pcaps_to_close(pcap_t *);
400 void	pcap_remove_from_pcaps_to_close(pcap_t *);
401 void	pcap_cleanup_live_common(pcap_t *);
402 int	pcap_check_activated(pcap_t *);
403 
404 /*
405  * Internal interfaces for "pcap_findalldevs()".
406  *
407  * "pcap_platform_finddevs()" is a platform-dependent routine to
408  * find local network interfaces.
409  *
410  * "pcap_findalldevs_interfaces()" is a helper to find those interfaces
411  * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
412  *
413  * "pcap_add_if()" adds an interface to the list of interfaces, for
414  * use by various "find interfaces" routines.
415  */
416 int	pcap_platform_finddevs(pcap_if_t **, char *);
417 #if !defined(_WIN32) && !defined(MSDOS)
418 int	pcap_findalldevs_interfaces(pcap_if_t **, char *,
419 	    int (*)(const char *));
420 #endif
421 int	add_addr_to_iflist(pcap_if_t **, const char *, bpf_u_int32,
422 	    struct sockaddr *, size_t, struct sockaddr *, size_t,
423 	    struct sockaddr *, size_t, struct sockaddr *, size_t, char *);
424 int	add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t,
425 	    struct sockaddr *, size_t, struct sockaddr *, size_t,
426 	    struct sockaddr *dstaddr, size_t, char *errbuf);
427 int	pcap_add_if(pcap_if_t **, const char *, bpf_u_int32, const char *,
428 	    char *);
429 int	add_or_find_if(pcap_if_t **, pcap_if_t **, const char *, bpf_u_int32,
430 	    const char *, char *);
431 #ifndef _WIN32
432 bpf_u_int32 if_flags_to_pcap_flags(const char *, u_int);
433 #endif
434 
435 /*
436  * Internal interfaces for "pcap_open_offline()".
437  *
438  * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
439  * by pcap_open_offline routines.
440  *
441  * "sf_cleanup()" closes the file handle associated with a pcap_t, if
442  * appropriate, and frees all data common to all modules for handling
443  * savefile types.
444  */
445 pcap_t	*pcap_open_offline_common(char *ebuf, size_t size);
446 void	sf_cleanup(pcap_t *p);
447 
448 /*
449  * Internal interfaces for both "pcap_create()" and routines that
450  * open savefiles.
451  *
452  * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
453  * and "pcap_next_ex()".
454  */
455 void	pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *);
456 
457 #ifdef _WIN32
458 void	pcap_win32_err_to_str(DWORD, char *);
459 #endif
460 
461 int	install_bpf_program(pcap_t *, struct bpf_program *);
462 
463 int	pcap_strcasecmp(const char *, const char *);
464 
465 #ifdef __cplusplus
466 }
467 #endif
468 
469 #endif
470