xref: /netbsd-src/external/bsd/tcpdump/dist/tcpdump.c (revision 26ba0b503b498a5194a71ac319838b7f5497f3fe)
1 /*
2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
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  * Support for splitting captures into multiple files with a maximum
22  * file size:
23  *
24  * Copyright (c) 2001
25  *	Seth Webster <swebster@sst.ll.mit.edu>
26  */
27 
28 #include <sys/cdefs.h>
29 #ifndef lint
30 __RCSID("$NetBSD: tcpdump.c,v 1.20 2024/09/02 16:15:33 christos Exp $");
31 #endif
32 
33 /*
34  * tcpdump - dump traffic on a network
35  *
36  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
37  * Mercilessly hacked and occasionally improved since then via the
38  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
39  */
40 
41 #include <config.h>
42 
43 /*
44  * Some older versions of Mac OS X ship pcap.h from libpcap 0.6 with a
45  * libpcap based on 0.8.  That means it has pcap_findalldevs() but the
46  * header doesn't define pcap_if_t, meaning that we can't actually *use*
47  * pcap_findalldevs().
48  */
49 #ifdef HAVE_PCAP_FINDALLDEVS
50 #ifndef HAVE_PCAP_IF_T
51 #undef HAVE_PCAP_FINDALLDEVS
52 #endif
53 #endif
54 
55 #include "netdissect-stdinc.h"
56 
57 /*
58  * This must appear after including netdissect-stdinc.h, so that _U_ is
59  * defined.
60  */
61 #ifndef lint
62 static const char copyright[] _U_ =
63     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
64 The Regents of the University of California.  All rights reserved.\n";
65 #endif
66 
67 #include <sys/stat.h>
68 
69 #include <fcntl.h>
70 
71 #ifdef HAVE_LIBCRYPTO
72 #include <openssl/crypto.h>
73 #endif
74 
75 #ifdef HAVE_GETOPT_LONG
76 #include <getopt.h>
77 #else
78 #include "missing/getopt_long.h"
79 #endif
80 /* Capsicum-specific code requires macros from <net/bpf.h>, which will fail
81  * to compile if <pcap.h> has already been included; including the headers
82  * in the opposite order works fine. For the most part anyway, because in
83  * FreeBSD <pcap/pcap.h> declares bpf_dump() instead of <net/bpf.h>. Thus
84  * interface.h takes care of it later to avoid a compiler warning.
85  */
86 #ifdef HAVE_CAPSICUM
87 #include <sys/capsicum.h>
88 #include <sys/ioccom.h>
89 #include <net/bpf.h>
90 #include <libgen.h>
91 #ifdef HAVE_CASPER
92 #include <libcasper.h>
93 #include <casper/cap_dns.h>
94 #include <sys/nv.h>
95 #endif	/* HAVE_CASPER */
96 #endif	/* HAVE_CAPSICUM */
97 #ifdef HAVE_PCAP_OPEN
98 /*
99  * We found pcap_open() in the capture library, so we'll be using
100  * the remote capture APIs; define PCAP_REMOTE before we include pcap.h,
101  * so we get those APIs declared, and the types and #defines that they
102  * use defined.
103  *
104  * WinPcap's headers require that PCAP_REMOTE be defined in order to get
105  * remote-capture APIs declared and types and #defines that they use
106  * defined.
107  *
108  * (Versions of libpcap with those APIs, and thus Npcap, which is based on
109  * those versions of libpcap, don't require it.)
110  */
111 #define HAVE_REMOTE
112 #endif
113 #include <pcap.h>
114 #include <signal.h>
115 #include <stdio.h>
116 #include <stdarg.h>
117 #include <stdlib.h>
118 #include <string.h>
119 #include <limits.h>
120 #include <resolv.h>
121 #ifdef _WIN32
122 #include <windows.h>
123 #else
124 #include <sys/time.h>
125 #include <sys/wait.h>
126 #include <sys/resource.h>
127 #include <pwd.h>
128 #include <grp.h>
129 #endif /* _WIN32 */
130 
131 /*
132  * Pathname separator.
133  * Use this in pathnames, but do *not* use it in URLs.
134  */
135 #ifdef _WIN32
136 #define PATH_SEPARATOR	'\\'
137 #else
138 #define PATH_SEPARATOR	'/'
139 #endif
140 
141 /* capabilities convenience library */
142 /* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
143  * If HAVE_CAP_NG_H is not defined, undefine HAVE_LIBCAP_NG.
144  * Thus, the later tests are done only on HAVE_LIBCAP_NG.
145  */
146 #ifdef HAVE_LIBCAP_NG
147 #ifdef HAVE_CAP_NG_H
148 #include <cap-ng.h>
149 #else
150 #undef HAVE_LIBCAP_NG
151 #endif /* HAVE_CAP_NG_H */
152 #endif /* HAVE_LIBCAP_NG */
153 
154 #ifdef __FreeBSD__
155 #include <sys/sysctl.h>
156 #endif /* __FreeBSD__ */
157 
158 #include "netdissect-stdinc.h"
159 #include "netdissect.h"
160 #include "interface.h"
161 #include "addrtoname.h"
162 #include "machdep.h"
163 #include "pcap-missing.h"
164 #include "ascii_strcasecmp.h"
165 
166 #include "print.h"
167 
168 #include "diag-control.h"
169 
170 #include "fptype.h"
171 
172 #ifndef PATH_MAX
173 #define PATH_MAX 1024
174 #endif
175 
176 #if defined(SIGINFO)
177 #define SIGNAL_REQ_INFO SIGINFO
178 #elif defined(SIGUSR1)
179 #define SIGNAL_REQ_INFO SIGUSR1
180 #endif
181 
182 #if defined(HAVE_PCAP_DUMP_FLUSH) && defined(SIGUSR2)
183 #define SIGNAL_FLUSH_PCAP SIGUSR2
184 #endif
185 
186 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
187 static int Bflag;			/* buffer size */
188 #endif
189 #ifdef HAVE_PCAP_DUMP_FTELL64
190 static int64_t Cflag;			/* rotate dump files after this many bytes */
191 #else
192 static long Cflag;			/* rotate dump files after this many bytes */
193 #endif
194 static int Cflag_count;			/* Keep track of which file number we're writing */
195 #ifdef HAVE_PCAP_FINDALLDEVS
196 static int Dflag;			/* list available devices and exit */
197 #endif
198 #ifdef HAVE_PCAP_FINDALLDEVS_EX
199 static char *remote_interfaces_source;	/* list available devices from this source and exit */
200 #endif
201 
202 /*
203  * This is exported because, in some versions of libpcap, if libpcap
204  * is built with optimizer debugging code (which is *NOT* the default
205  * configuration!), the library *imports*(!) a variable named dflag,
206  * under the expectation that tcpdump is exporting it, to govern
207  * how much debugging information to print when optimizing
208  * the generated BPF code.
209  *
210  * This is a horrible hack; newer versions of libpcap don't import
211  * dflag but, instead, *if* built with optimizer debugging code,
212  * *export* a routine to set that flag.
213  */
214 extern int dflag;
215 int dflag;				/* print filter code */
216 static int Gflag;			/* rotate dump files after this many seconds */
217 static int Gflag_count;			/* number of files created with Gflag rotation */
218 static time_t Gflag_time;		/* The last time_t the dump file was rotated. */
219 static int Lflag;			/* list available data link types and exit */
220 static int Iflag;			/* rfmon (monitor) mode */
221 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
222 static int Jflag;			/* list available time stamp types */
223 static int jflag = -1;			/* packet time stamp source */
224 #endif
225 static int lflag;			/* line-buffered output */
226 static int pflag;			/* don't go promiscuous */
227 #ifdef HAVE_PCAP_SETDIRECTION
228 static int Qflag = -1;			/* restrict captured packet by send/receive direction */
229 #endif
230 #ifdef HAVE_PCAP_DUMP_FLUSH
231 static int Uflag;			/* "unbuffered" output of dump files */
232 #endif
233 static int Wflag;			/* recycle output files after this number of files */
234 static int WflagChars;
235 static char *zflag = NULL;		/* compress each savefile using a specified command (like gzip or bzip2) */
236 static int timeout = 1000;		/* default timeout = 1000 ms = 1 s */
237 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
238 static int immediate_mode;
239 #endif
240 static int count_mode;
241 
242 static int infodelay;
243 static int infoprint;
244 
245 char *program_name;
246 
247 /* Forwards */
248 static NORETURN void error(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
249 static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
250 static NORETURN void exit_tcpdump(int);
251 static void (*setsignal (int sig, void (*func)(int)))(int);
252 static void cleanup(int);
253 static void child_cleanup(int);
254 static void print_version(FILE *);
255 static void print_usage(FILE *);
256 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
257 static NORETURN void show_tstamp_types_and_exit(pcap_t *, const char *device);
258 #endif
259 static NORETURN void show_dlts_and_exit(pcap_t *, const char *device);
260 #ifdef HAVE_PCAP_FINDALLDEVS
261 static NORETURN void show_devices_and_exit(void);
262 #endif
263 #ifdef HAVE_PCAP_FINDALLDEVS_EX
264 static NORETURN void show_remote_devices_and_exit(void);
265 #endif
266 
267 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
268 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
269 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
270 static void droproot(const char *, const char *);
271 
272 #ifdef SIGNAL_REQ_INFO
273 static void requestinfo(int);
274 #endif
275 
276 #ifdef SIGNAL_FLUSH_PCAP
277 static void flushpcap(int);
278 #endif
279 
280 #ifdef _WIN32
281     static HANDLE timer_handle = INVALID_HANDLE_VALUE;
282     static void CALLBACK verbose_stats_dump(PVOID param, BOOLEAN timer_fired);
283 #else /* _WIN32 */
284   static void verbose_stats_dump(int sig);
285 #endif /* _WIN32 */
286 
287 static void info(int);
288 static u_int packets_captured;
289 
290 #ifdef HAVE_PCAP_FINDALLDEVS
291 static const struct tok status_flags[] = {
292 #ifdef PCAP_IF_UP
293 	{ PCAP_IF_UP,       "Up"       },
294 #endif
295 #ifdef PCAP_IF_RUNNING
296 	{ PCAP_IF_RUNNING,  "Running"  },
297 #endif
298 	{ PCAP_IF_LOOPBACK, "Loopback" },
299 #ifdef PCAP_IF_WIRELESS
300 	{ PCAP_IF_WIRELESS, "Wireless" },
301 #endif
302 	{ 0, NULL }
303 };
304 #endif
305 
306 static pcap_t *pd;
307 static pcap_dumper_t *pdd = NULL;
308 
309 static int supports_monitor_mode;
310 
311 extern int optind;
312 extern int opterr;
313 extern char *optarg;
314 
315 struct dump_info {
316 	char	*WFileName;
317 	char	*CurrentFileName;
318 	pcap_t	*pd;
319 	pcap_dumper_t *pdd;
320 	netdissect_options *ndo;
321 #ifdef HAVE_CAPSICUM
322 	int	dirfd;
323 #endif
324 };
325 
326 #if defined(HAVE_PCAP_SET_PARSER_DEBUG)
327 /*
328  * We have pcap_set_parser_debug() in libpcap; declare it (it's not declared
329  * by any libpcap header, because it's a special hack, only available if
330  * libpcap was configured to include it, and only intended for use by
331  * libpcap developers trying to debug the parser for filter expressions).
332  */
333 #ifdef _WIN32
334 __declspec(dllimport)
335 #else /* _WIN32 */
336 extern
337 #endif /* _WIN32 */
338 void pcap_set_parser_debug(int);
339 #elif defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
340 /*
341  * We don't have pcap_set_parser_debug() in libpcap, but we do have
342  * pcap_debug or yydebug.  Make a local version of pcap_set_parser_debug()
343  * to set the flag, and define HAVE_PCAP_SET_PARSER_DEBUG.
344  */
345 static void
346 pcap_set_parser_debug(int value)
347 {
348 #ifdef HAVE_PCAP_DEBUG
349 	extern int pcap_debug __weak;
350 
351 	if (&pcap_debug)
352 		pcap_debug = value;
353 #else /* HAVE_PCAP_DEBUG */
354 	extern int yydebug;
355 
356 	yydebug = value;
357 #endif /* HAVE_PCAP_DEBUG */
358 }
359 
360 #define HAVE_PCAP_SET_PARSER_DEBUG
361 #endif
362 
363 #if defined(HAVE_PCAP_SET_OPTIMIZER_DEBUG)
364 /*
365  * We have pcap_set_optimizer_debug() in libpcap; declare it (it's not declared
366  * by any libpcap header, because it's a special hack, only available if
367  * libpcap was configured to include it, and only intended for use by
368  * libpcap developers trying to debug the optimizer for filter expressions).
369  */
370 #ifdef _WIN32
371 __declspec(dllimport)
372 #else /* _WIN32 */
373 extern
374 #endif /* _WIN32 */
375 void pcap_set_optimizer_debug(int);
376 #endif
377 
378 /* VARARGS */
379 static void
380 error(const char *fmt, ...)
381 {
382 	va_list ap;
383 
384 	(void)fprintf(stderr, "%s: ", program_name);
385 	va_start(ap, fmt);
386 	(void)vfprintf(stderr, fmt, ap);
387 	va_end(ap);
388 	if (*fmt) {
389 		fmt += strlen(fmt);
390 		if (fmt[-1] != '\n')
391 			(void)fputc('\n', stderr);
392 	}
393 	exit_tcpdump(S_ERR_HOST_PROGRAM);
394 	/* NOTREACHED */
395 }
396 
397 /* VARARGS */
398 static void
399 warning(const char *fmt, ...)
400 {
401 	va_list ap;
402 
403 	(void)fprintf(stderr, "%s: WARNING: ", program_name);
404 	va_start(ap, fmt);
405 	(void)vfprintf(stderr, fmt, ap);
406 	va_end(ap);
407 	if (*fmt) {
408 		fmt += strlen(fmt);
409 		if (fmt[-1] != '\n')
410 			(void)fputc('\n', stderr);
411 	}
412 }
413 
414 static void
415 exit_tcpdump(int status)
416 {
417 	nd_cleanup();
418 	exit(status);
419 }
420 
421 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
422 static void
423 show_tstamp_types_and_exit(pcap_t *pc, const char *device)
424 {
425 	int n_tstamp_types;
426 	int *tstamp_types = 0;
427 	const char *tstamp_type_name;
428 	int i;
429 
430 	n_tstamp_types = pcap_list_tstamp_types(pc, &tstamp_types);
431 	if (n_tstamp_types < 0)
432 		error("%s", pcap_geterr(pc));
433 
434 	if (n_tstamp_types == 0) {
435 		fprintf(stderr, "Time stamp type cannot be set for %s\n",
436 		    device);
437 		exit_tcpdump(S_SUCCESS);
438 	}
439 	fprintf(stdout, "Time stamp types for %s (use option -j to set):\n",
440 	    device);
441 	for (i = 0; i < n_tstamp_types; i++) {
442 		tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
443 		if (tstamp_type_name != NULL) {
444 			(void) fprintf(stdout, "  %s (%s)\n", tstamp_type_name,
445 			    pcap_tstamp_type_val_to_description(tstamp_types[i]));
446 		} else {
447 			(void) fprintf(stdout, "  %d\n", tstamp_types[i]);
448 		}
449 	}
450 	pcap_free_tstamp_types(tstamp_types);
451 	exit_tcpdump(S_SUCCESS);
452 }
453 #endif
454 
455 static void
456 show_dlts_and_exit(pcap_t *pc, const char *device)
457 {
458 	int n_dlts, i;
459 	int *dlts = 0;
460 	const char *dlt_name;
461 
462 	n_dlts = pcap_list_datalinks(pc, &dlts);
463 	if (n_dlts < 0)
464 		error("%s", pcap_geterr(pc));
465 	else if (n_dlts == 0 || !dlts)
466 		error("No data link types.");
467 
468 	/*
469 	 * If the interface is known to support monitor mode, indicate
470 	 * whether these are the data link types available when not in
471 	 * monitor mode, if -I wasn't specified, or when in monitor mode,
472 	 * when -I was specified (the link-layer types available in
473 	 * monitor mode might be different from the ones available when
474 	 * not in monitor mode).
475 	 */
476 	(void) fprintf(stdout, "Data link types for ");
477 	if (supports_monitor_mode)
478 		(void) fprintf(stdout, "%s %s",
479 		    device,
480 		    Iflag ? "when in monitor mode" : "when not in monitor mode");
481 	else
482 		(void) fprintf(stdout, "%s",
483 		    device);
484 	(void) fprintf(stdout, " (use option -y to set):\n");
485 
486 	for (i = 0; i < n_dlts; i++) {
487 		dlt_name = pcap_datalink_val_to_name(dlts[i]);
488 		if (dlt_name != NULL) {
489 			(void) fprintf(stdout, "  %s (%s)", dlt_name,
490 			    pcap_datalink_val_to_description(dlts[i]));
491 
492 			/*
493 			 * OK, does tcpdump handle that type?
494 			 */
495 			if (!has_printer(dlts[i]))
496 				(void) fprintf(stdout, " (printing not supported)");
497 			fprintf(stdout, "\n");
498 		} else {
499 			(void) fprintf(stdout, "  DLT %d (printing not supported)\n",
500 			    dlts[i]);
501 		}
502 	}
503 #ifdef HAVE_PCAP_FREE_DATALINKS
504 	pcap_free_datalinks(dlts);
505 #endif
506 	exit_tcpdump(S_SUCCESS);
507 }
508 
509 #ifdef HAVE_PCAP_FINDALLDEVS
510 static void
511 show_devices_and_exit(void)
512 {
513 	pcap_if_t *dev, *devlist;
514 	char ebuf[PCAP_ERRBUF_SIZE];
515 	int i;
516 
517 	if (pcap_findalldevs(&devlist, ebuf) < 0)
518 		error("%s", ebuf);
519 	for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
520 		printf("%d.%s", i+1, dev->name);
521 		if (dev->description != NULL)
522 			printf(" (%s)", dev->description);
523 		if (dev->flags != 0) {
524 			printf(" [");
525 			printf("%s", bittok2str(status_flags, "none", dev->flags));
526 #ifdef PCAP_IF_WIRELESS
527 			if (dev->flags & PCAP_IF_WIRELESS) {
528 				switch (dev->flags & PCAP_IF_CONNECTION_STATUS) {
529 
530 				case PCAP_IF_CONNECTION_STATUS_UNKNOWN:
531 					printf(", Association status unknown");
532 					break;
533 
534 				case PCAP_IF_CONNECTION_STATUS_CONNECTED:
535 					printf(", Associated");
536 					break;
537 
538 				case PCAP_IF_CONNECTION_STATUS_DISCONNECTED:
539 					printf(", Not associated");
540 					break;
541 
542 				case PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE:
543 					break;
544 				}
545 			} else {
546 				switch (dev->flags & PCAP_IF_CONNECTION_STATUS) {
547 
548 				case PCAP_IF_CONNECTION_STATUS_UNKNOWN:
549 					printf(", Connection status unknown");
550 					break;
551 
552 				case PCAP_IF_CONNECTION_STATUS_CONNECTED:
553 					printf(", Connected");
554 					break;
555 
556 				case PCAP_IF_CONNECTION_STATUS_DISCONNECTED:
557 					printf(", Disconnected");
558 					break;
559 
560 				case PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE:
561 					break;
562 				}
563 			}
564 #endif
565 			printf("]");
566 		}
567 		printf("\n");
568 	}
569 	pcap_freealldevs(devlist);
570 	exit_tcpdump(S_SUCCESS);
571 }
572 #endif /* HAVE_PCAP_FINDALLDEVS */
573 
574 #ifdef HAVE_PCAP_FINDALLDEVS_EX
575 static void
576 show_remote_devices_and_exit(void)
577 {
578 	pcap_if_t *dev, *devlist;
579 	char ebuf[PCAP_ERRBUF_SIZE];
580 	int i;
581 
582 	if (pcap_findalldevs_ex(remote_interfaces_source, NULL, &devlist,
583 	    ebuf) < 0)
584 		error("%s", ebuf);
585 	for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
586 		printf("%d.%s", i+1, dev->name);
587 		if (dev->description != NULL)
588 			printf(" (%s)", dev->description);
589 		if (dev->flags != 0)
590 			printf(" [%s]", bittok2str(status_flags, "none", dev->flags));
591 		printf("\n");
592 	}
593 	pcap_freealldevs(devlist);
594 	exit_tcpdump(S_SUCCESS);
595 }
596 #endif /* HAVE_PCAP_FINDALLDEVS */
597 
598 /*
599  * Short options.
600  *
601  * Note that there we use all letters for short options except for g, k,
602  * o, and P, and those are used by other versions of tcpdump, and we should
603  * only use them for the same purposes that the other versions of tcpdump
604  * use them:
605  *
606  * macOS tcpdump uses -g to force non--v output for IP to be on one
607  * line, making it more "g"repable;
608  *
609  * macOS tcpdump uses -k to specify that packet comments in pcapng files
610  * should be printed;
611  *
612  * OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
613  * for hosts sending TCP SYN packets;
614  *
615  * macOS tcpdump uses -P to indicate that -w should write pcapng rather
616  * than pcap files.
617  *
618  * macOS tcpdump also uses -Q to specify expressions that match packet
619  * metadata, including but not limited to the packet direction.
620  * The expression syntax is different from a simple "in|out|inout",
621  * and those expressions aren't accepted by macOS tcpdump, but the
622  * equivalents would be "in" = "dir=in", "out" = "dir=out", and
623  * "inout" = "dir=in or dir=out", and the parser could conceivably
624  * special-case "in", "out", and "inout" as expressions for backwards
625  * compatibility, so all is not (yet) lost.
626  */
627 
628 /*
629  * Set up flags that might or might not be supported depending on the
630  * version of libpcap we're using.
631  */
632 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
633 #define B_FLAG		"B:"
634 #define B_FLAG_USAGE	" [ -B size ]"
635 #else /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
636 #define B_FLAG
637 #define B_FLAG_USAGE
638 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
639 
640 #ifdef HAVE_PCAP_FINDALLDEVS
641 #define D_FLAG	"D"
642 #else
643 #define D_FLAG
644 #endif
645 
646 #ifdef HAVE_PCAP_CREATE
647 #define I_FLAG		"I"
648 #else /* HAVE_PCAP_CREATE */
649 #define I_FLAG
650 #endif /* HAVE_PCAP_CREATE */
651 
652 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
653 #define j_FLAG		"j:"
654 #define j_FLAG_USAGE	" [ -j tstamptype ]"
655 #define J_FLAG		"J"
656 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
657 #define j_FLAG
658 #define j_FLAG_USAGE
659 #define J_FLAG
660 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
661 
662 #ifdef USE_LIBSMI
663 #define m_FLAG_USAGE "[ -m module ] ..."
664 #endif
665 
666 #ifdef HAVE_PCAP_SETDIRECTION
667 #define Q_FLAG "Q:"
668 #define Q_FLAG_USAGE " [ -Q in|out|inout ]"
669 #else
670 #define Q_FLAG
671 #define Q_FLAG_USAGE
672 #endif
673 
674 #ifdef HAVE_PCAP_DUMP_FLUSH
675 #define U_FLAG	"U"
676 #else
677 #define U_FLAG
678 #endif
679 
680 #define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:s:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
681 
682 /*
683  * Long options.
684  *
685  * We do not currently have long options corresponding to all short
686  * options; we should probably pick appropriate option names for them.
687  *
688  * However, the short options where the number of times the option is
689  * specified matters, such as -v and -d and -t, should probably not
690  * just map to a long option, as saying
691  *
692  *  tcpdump --verbose --verbose
693  *
694  * doesn't make sense; it should be --verbosity={N} or something such
695  * as that.
696  *
697  * For long options with no corresponding short options, we define values
698  * outside the range of ASCII graphic characters, make that the last
699  * component of the entry for the long option, and have a case for that
700  * option in the switch statement.
701  */
702 #define OPTION_VERSION			128
703 #define OPTION_TSTAMP_PRECISION		129
704 #define OPTION_IMMEDIATE_MODE		130
705 #define OPTION_PRINT			131
706 #define OPTION_LIST_REMOTE_INTERFACES	132
707 #define OPTION_TSTAMP_MICRO		133
708 #define OPTION_TSTAMP_NANO		134
709 #define OPTION_FP_TYPE			135
710 #define OPTION_COUNT			136
711 
712 static const struct option longopts[] = {
713 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
714 	{ "buffer-size", required_argument, NULL, 'B' },
715 #endif
716 	{ "list-interfaces", no_argument, NULL, 'D' },
717 #ifdef HAVE_PCAP_FINDALLDEVS_EX
718 	{ "list-remote-interfaces", required_argument, NULL, OPTION_LIST_REMOTE_INTERFACES },
719 #endif
720 	{ "help", no_argument, NULL, 'h' },
721 	{ "interface", required_argument, NULL, 'i' },
722 #ifdef HAVE_PCAP_CREATE
723 	{ "monitor-mode", no_argument, NULL, 'I' },
724 #endif
725 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
726 	{ "time-stamp-type", required_argument, NULL, 'j' },
727 	{ "list-time-stamp-types", no_argument, NULL, 'J' },
728 #endif
729 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
730 	{ "micro", no_argument, NULL, OPTION_TSTAMP_MICRO},
731 	{ "nano", no_argument, NULL, OPTION_TSTAMP_NANO},
732 	{ "time-stamp-precision", required_argument, NULL, OPTION_TSTAMP_PRECISION},
733 #endif
734 	{ "dont-verify-checksums", no_argument, NULL, 'K' },
735 	{ "list-data-link-types", no_argument, NULL, 'L' },
736 	{ "no-optimize", no_argument, NULL, 'O' },
737 	{ "no-promiscuous-mode", no_argument, NULL, 'p' },
738 #ifdef HAVE_PCAP_SETDIRECTION
739 	{ "direction", required_argument, NULL, 'Q' },
740 #endif
741 	{ "snapshot-length", required_argument, NULL, 's' },
742 	{ "absolute-tcp-sequence-numbers", no_argument, NULL, 'S' },
743 #ifdef HAVE_PCAP_DUMP_FLUSH
744 	{ "packet-buffered", no_argument, NULL, 'U' },
745 #endif
746 	{ "linktype", required_argument, NULL, 'y' },
747 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
748 	{ "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
749 #endif
750 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
751 	{ "debug-filter-parser", no_argument, NULL, 'Y' },
752 #endif
753 	{ "relinquish-privileges", required_argument, NULL, 'Z' },
754 	{ "count", no_argument, NULL, OPTION_COUNT },
755 	{ "fp-type", no_argument, NULL, OPTION_FP_TYPE },
756 	{ "number", no_argument, NULL, '#' },
757 	{ "print", no_argument, NULL, OPTION_PRINT },
758 	{ "version", no_argument, NULL, OPTION_VERSION },
759 	{ NULL, 0, NULL, 0 }
760 };
761 
762 #ifdef HAVE_PCAP_FINDALLDEVS_EX
763 #define LIST_REMOTE_INTERFACES_USAGE "[ --list-remote-interfaces remote-source ]"
764 #else
765 #define LIST_REMOTE_INTERFACES_USAGE
766 #endif
767 
768 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
769 #define IMMEDIATE_MODE_USAGE " [ --immediate-mode ]"
770 #else
771 #define IMMEDIATE_MODE_USAGE ""
772 #endif
773 
774 #ifndef _WIN32
775 /* Drop root privileges and chroot if necessary */
776 static void
777 droproot(const char *username, const char *chroot_dir)
778 {
779 	struct passwd *pw = NULL;
780 
781 	if (chroot_dir && !username)
782 		error("Chroot without dropping root is insecure");
783 
784 	pw = getpwnam(username);
785 	if (pw) {
786 		if (initgroups(pw->pw_name, pw->pw_gid) != 0) {
787 			fprintf(stderr, "tcpdump: Couldn't initgroups to "
788 			    "'%.32s' gid=%lu: %s\n", pw->pw_name,
789 			    (unsigned long)pw->pw_gid,
790 			    pcap_strerror(errno));
791 			exit(1);
792 		}
793 		if (chroot_dir) {
794 			setprotoent(1);
795 			res_init();
796 			if (chroot(chroot_dir) != 0 || chdir ("/") != 0)
797 				error("Couldn't chroot/chdir to '%.64s': %s",
798 				      chroot_dir, pcap_strerror(errno));
799 		}
800 #ifdef HAVE_LIBCAP_NG
801 		{
802 			int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
803 			if (ret < 0)
804 				error("capng_change_id(): return %d\n", ret);
805 			else
806 				fprintf(stderr, "dropped privs to %s\n", username);
807 		}
808 #else
809 		if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
810 		    setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0)
811 			error("Couldn't change to '%.32s' uid=%lu gid=%lu: %s",
812 				username,
813 				(unsigned long)pw->pw_uid,
814 				(unsigned long)pw->pw_gid,
815 				pcap_strerror(errno));
816 		else {
817 //			fprintf(stderr, "dropped privs to %s\n", username);
818 		}
819 #endif /* HAVE_LIBCAP_NG */
820 	} else
821 		error("Couldn't find user '%.32s'", username);
822 #ifdef HAVE_LIBCAP_NG
823 	/* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT anymore. */
824 DIAG_OFF_ASSIGN_ENUM
825 	capng_updatev(
826 		CAPNG_DROP,
827 		CAPNG_EFFECTIVE | CAPNG_PERMITTED,
828 		CAP_SETUID,
829 		CAP_SETGID,
830 		CAP_SYS_CHROOT,
831 		-1);
832 DIAG_ON_ASSIGN_ENUM
833 	capng_apply(CAPNG_SELECT_BOTH);
834 #endif /* HAVE_LIBCAP_NG */
835 
836 }
837 #endif /* _WIN32 */
838 
839 static int
840 getWflagChars(int x)
841 {
842 	int c = 0;
843 
844 	x -= 1;
845 	while (x > 0) {
846 		c += 1;
847 		x /= 10;
848 	}
849 
850 	return c;
851 }
852 
853 
854 static void
855 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
856 {
857         char *filename = malloc(PATH_MAX + 1);
858         if (filename == NULL)
859             error("%s: malloc", __func__);
860         if (strlen(orig_name) == 0)
861             error("an empty string is not a valid file name");
862 
863         /* Process with strftime if Gflag is set. */
864         if (Gflag != 0) {
865           struct tm *local_tm;
866 
867           /* Convert Gflag_time to a usable format */
868           if ((local_tm = localtime(&Gflag_time)) == NULL) {
869                   error("%s: localtime", __func__);
870           }
871 
872           /* There's no good way to detect an error in strftime since a return
873            * value of 0 isn't necessarily failure; if orig_name is an empty
874            * string, the formatted string will be empty.
875            *
876            * However, the C90 standard says that, if there *is* a
877            * buffer overflow, the content of the buffer is undefined,
878            * so we must check for a buffer overflow.
879            *
880            * So we check above for an empty orig_name, and only call
881            * strftime() if it's non-empty, in which case the return
882            * value will only be 0 if the formatted date doesn't fit
883            * in the buffer.
884            *
885            * (We check above because, even if we don't use -G, we
886            * want a better error message than "tcpdump: : No such
887            * file or directory" for this case.)
888            */
889           if (strftime(filename, PATH_MAX, orig_name, local_tm) == 0) {
890             error("%s: strftime", __func__);
891           }
892         } else {
893           strncpy(filename, orig_name, PATH_MAX);
894         }
895 
896 	if (cnt == 0 && max_chars == 0)
897 		strncpy(buffer, filename, PATH_MAX + 1);
898 	else
899 		if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
900                   /* Report an error if the filename is too large */
901                   error("too many output files or filename is too long (> %d)", PATH_MAX);
902         free(filename);
903 }
904 
905 static char *
906 get_next_file(FILE *VFile, char *ptr)
907 {
908 	char *ret;
909 	size_t len;
910 
911 	ret = fgets(ptr, PATH_MAX, VFile);
912 	if (!ret)
913 		return NULL;
914 
915 	len = strlen (ptr);
916 	if (len > 0 && ptr[len - 1] == '\n')
917 		ptr[len - 1] = '\0';
918 
919 	return ret;
920 }
921 
922 #ifdef HAVE_CASPER
923 static cap_channel_t *
924 capdns_setup(void)
925 {
926 	cap_channel_t *capcas, *capdnsloc;
927 	const char *types[1];
928 	int families[2];
929 
930 	capcas = cap_init();
931 	if (capcas == NULL)
932 		error("unable to create casper process");
933 	capdnsloc = cap_service_open(capcas, "system.dns");
934 	/* Casper capability no longer needed. */
935 	cap_close(capcas);
936 	if (capdnsloc == NULL)
937 		error("unable to open system.dns service");
938 	/* Limit system.dns to reverse DNS lookups. */
939 	types[0] = "ADDR";
940 	if (cap_dns_type_limit(capdnsloc, types, 1) < 0)
941 		error("unable to limit access to system.dns service");
942 	families[0] = AF_INET;
943 	families[1] = AF_INET6;
944 	if (cap_dns_family_limit(capdnsloc, families, 2) < 0)
945 		error("unable to limit access to system.dns service");
946 
947 	return (capdnsloc);
948 }
949 #endif	/* HAVE_CASPER */
950 
951 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
952 static int
953 tstamp_precision_from_string(const char *precision)
954 {
955 	if (strncmp(precision, "nano", strlen("nano")) == 0)
956 		return PCAP_TSTAMP_PRECISION_NANO;
957 
958 	if (strncmp(precision, "micro", strlen("micro")) == 0)
959 		return PCAP_TSTAMP_PRECISION_MICRO;
960 
961 	return -EINVAL;
962 }
963 
964 static const char *
965 tstamp_precision_to_string(int precision)
966 {
967 	switch (precision) {
968 
969 	case PCAP_TSTAMP_PRECISION_MICRO:
970 		return "micro";
971 
972 	case PCAP_TSTAMP_PRECISION_NANO:
973 		return "nano";
974 
975 	default:
976 		return "unknown";
977 	}
978 }
979 #endif
980 
981 #ifdef HAVE_CAPSICUM
982 /*
983  * Ensure that, on a dump file's descriptor, we have all the rights
984  * necessary to make the standard I/O library work with an fdopen()ed
985  * FILE * from that descriptor.
986  *
987  * A long time ago in a galaxy far, far away, AT&T decided that, instead
988  * of providing separate APIs for getting and setting the FD_ flags on a
989  * descriptor, getting and setting the O_ flags on a descriptor, and
990  * locking files, they'd throw them all into a kitchen-sink fcntl() call
991  * along the lines of ioctl(), the fact that ioctl() operations are
992  * largely specific to particular character devices but fcntl() operations
993  * are either generic to all descriptors or generic to all descriptors for
994  * regular files notwithstanding.
995  *
996  * The Capsicum people decided that fine-grained control of descriptor
997  * operations was required, so that you need to grant permission for
998  * reading, writing, seeking, and fcntl-ing.  The latter, courtesy of
999  * AT&T's decision, means that "fcntl-ing" isn't a thing, but a motley
1000  * collection of things, so there are *individual* fcntls for which
1001  * permission needs to be granted.
1002  *
1003  * The FreeBSD standard I/O people implemented some optimizations that
1004  * requires that the standard I/O routines be able to determine whether
1005  * the descriptor for the FILE * is open append-only or not; as that
1006  * descriptor could have come from an open() rather than an fopen(),
1007  * that requires that it be able to do an F_GETFL fcntl() to read
1008  * the O_ flags.
1009  *
1010  * Tcpdump uses ftell() to determine how much data has been written
1011  * to a file in order to, when used with -C, determine when it's time
1012  * to rotate capture files.  ftell() therefore needs to do an lseek()
1013  * to find out the file offset and must, thanks to the aforementioned
1014  * optimization, also know whether the descriptor is open append-only
1015  * or not.
1016  *
1017  * The net result of all the above is that we need to grant CAP_SEEK,
1018  * CAP_WRITE, and CAP_FCNTL with the CAP_FCNTL_GETFL subcapability.
1019  *
1020  * Perhaps this is the universe's way of saying that either
1021  *
1022  *	1) there needs to be an fopenat() call and a pcap_dump_openat() call
1023  *	   using it, so that Capsicum-capable tcpdump wouldn't need to do
1024  *	   an fdopen()
1025  *
1026  * or
1027  *
1028  *	2) there needs to be a cap_fdopen() call in the FreeBSD standard
1029  *	   I/O library that knows what rights are needed by the standard
1030  *	   I/O library, based on the open mode, and assigns them, perhaps
1031  *	   with an additional argument indicating, for example, whether
1032  *	   seeking should be allowed, so that tcpdump doesn't need to know
1033  *	   what the standard I/O library happens to require this week.
1034  */
1035 static void
1036 set_dumper_capsicum_rights(pcap_dumper_t *p)
1037 {
1038 	int fd = fileno(pcap_dump_file(p));
1039 	cap_rights_t rights;
1040 
1041 	cap_rights_init(&rights, CAP_SEEK, CAP_WRITE, CAP_FCNTL);
1042 	if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
1043 		error("unable to limit dump descriptor");
1044 	}
1045 	if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS) {
1046 		error("unable to limit dump descriptor fcntls");
1047 	}
1048 }
1049 #endif
1050 
1051 /*
1052  * Copy arg vector into a new buffer, concatenating arguments with spaces.
1053  */
1054 static char *
1055 copy_argv(char **argv)
1056 {
1057 	char **p;
1058 	size_t len = 0;
1059 	char *buf;
1060 	char *src, *dst;
1061 
1062 	p = argv;
1063 	if (*p == NULL)
1064 		return 0;
1065 
1066 	while (*p)
1067 		len += strlen(*p++) + 1;
1068 
1069 	buf = (char *)malloc(len);
1070 	if (buf == NULL)
1071 		error("%s: malloc", __func__);
1072 
1073 	p = argv;
1074 	dst = buf;
1075 	while ((src = *p++) != NULL) {
1076 		while ((*dst++ = *src++) != '\0')
1077 			;
1078 		dst[-1] = ' ';
1079 	}
1080 	dst[-1] = '\0';
1081 
1082 	return buf;
1083 }
1084 
1085 /*
1086  * On Windows, we need to open the file in binary mode, so that
1087  * we get all the bytes specified by the size we get from "fstat()".
1088  * On UNIX, that's not necessary.  O_BINARY is defined on Windows;
1089  * we define it as 0 if it's not defined, so it does nothing.
1090  */
1091 #ifndef O_BINARY
1092 #define O_BINARY	0
1093 #endif
1094 
1095 static char *
1096 read_infile(char *fname)
1097 {
1098 	int i, fd;
1099 	ssize_t cc;
1100 	char *cp;
1101 	our_statb buf;
1102 
1103 	fd = open(fname, O_RDONLY|O_BINARY);
1104 	if (fd < 0)
1105 		error("can't open %s: %s", fname, pcap_strerror(errno));
1106 
1107 	if (our_fstat(fd, &buf) < 0)
1108 		error("can't stat %s: %s", fname, pcap_strerror(errno));
1109 
1110 	/*
1111 	 * Reject files whose size doesn't fit into an int; a filter
1112 	 * *that* large will probably be too big.
1113 	 */
1114 	if (buf.st_size > INT_MAX)
1115 		error("%s is too large", fname);
1116 
1117 	cp = malloc((u_int)buf.st_size + 1);
1118 	if (cp == NULL)
1119 		error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
1120 			fname, pcap_strerror(errno));
1121 	cc = read(fd, cp, (u_int)buf.st_size);
1122 	if (cc < 0)
1123 		error("read %s: %s", fname, pcap_strerror(errno));
1124 	if (cc != buf.st_size)
1125 		error("short read %s (%d != %d)", fname, (int) cc,
1126 		    (int)buf.st_size);
1127 
1128 	close(fd);
1129 	/* replace "# comment" with spaces */
1130 	for (i = 0; i < cc; i++) {
1131 		if (cp[i] == '#')
1132 			while (i < cc && cp[i] != '\n')
1133 				cp[i++] = ' ';
1134 	}
1135 	cp[cc] = '\0';
1136 	return (cp);
1137 }
1138 
1139 #ifdef HAVE_PCAP_FINDALLDEVS
1140 static long
1141 parse_interface_number(const char *device)
1142 {
1143 	const char *p;
1144 	long devnum;
1145 	char *end;
1146 
1147 	/*
1148 	 * Search for a colon, terminating any scheme at the beginning
1149 	 * of the device.
1150 	 */
1151 	p = strchr(device, ':');
1152 	if (p != NULL) {
1153 		/*
1154 		 * We found it.  Is it followed by "//"?
1155 		 */
1156 		p++;	/* skip the : */
1157 		if (strncmp(p, "//", 2) == 0) {
1158 			/*
1159 			 * Yes.  Search for the next /, at the end of the
1160 			 * authority part of the URL.
1161 			 */
1162 			p += 2;	/* skip the // */
1163 			p = strchr(p, '/');
1164 			if (p != NULL) {
1165 				/*
1166 				 * OK, past the / is the path.
1167 				 */
1168 				device = p + 1;
1169 			}
1170 		}
1171 	}
1172 	devnum = strtol(device, &end, 10);
1173 	if (device != end && *end == '\0') {
1174 		/*
1175 		 * It's all-numeric, but is it a valid number?
1176 		 */
1177 		if (devnum <= 0) {
1178 			/*
1179 			 * No, it's not an ordinal.
1180 			 */
1181 			error("Invalid adapter index %s", device);
1182 		}
1183 		return (devnum);
1184 	} else {
1185 		/*
1186 		 * It's not all-numeric; return -1, so our caller
1187 		 * knows that.
1188 		 */
1189 		return (-1);
1190 	}
1191 }
1192 
1193 static char *
1194 find_interface_by_number(const char *url
1195 #ifndef HAVE_PCAP_FINDALLDEVS_EX
1196 _U_
1197 #endif
1198 , long devnum)
1199 {
1200 	pcap_if_t *dev, *devlist;
1201 	long i;
1202 	char ebuf[PCAP_ERRBUF_SIZE];
1203 	char *device;
1204 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1205 	const char *endp;
1206 	char *host_url;
1207 #endif
1208 	int status;
1209 
1210 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1211 	/*
1212 	 * Search for a colon, terminating any scheme at the beginning
1213 	 * of the URL.
1214 	 */
1215 	endp = strchr(url, ':');
1216 	if (endp != NULL) {
1217 		/*
1218 		 * We found it.  Is it followed by "//"?
1219 		 */
1220 		endp++;	/* skip the : */
1221 		if (strncmp(endp, "//", 2) == 0) {
1222 			/*
1223 			 * Yes.  Search for the next /, at the end of the
1224 			 * authority part of the URL.
1225 			 */
1226 			endp += 2;	/* skip the // */
1227 			endp = strchr(endp, '/');
1228 		} else
1229 			endp = NULL;
1230 	}
1231 	if (endp != NULL) {
1232 		/*
1233 		 * OK, everything from device to endp is a URL to hand
1234 		 * to pcap_findalldevs_ex().
1235 		 */
1236 		endp++;	/* Include the trailing / in the URL; pcap_findalldevs_ex() requires it */
1237 		host_url = malloc(endp - url + 1);
1238 		if (host_url == NULL && (endp - url + 1) > 0)
1239 			error("Invalid allocation for host");
1240 
1241 		memcpy(host_url, url, endp - url);
1242 		host_url[endp - url] = '\0';
1243 		status = pcap_findalldevs_ex(host_url, NULL, &devlist, ebuf);
1244 		free(host_url);
1245 	} else
1246 #endif
1247 	status = pcap_findalldevs(&devlist, ebuf);
1248 	if (status < 0)
1249 		error("%s", ebuf);
1250 	/*
1251 	 * Look for the devnum-th entry in the list of devices (1-based).
1252 	 */
1253 	for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
1254 	    i++, dev = dev->next)
1255 		;
1256 	if (dev == NULL) {
1257 		pcap_freealldevs(devlist);
1258 		error("Invalid adapter index %ld: only %ld interfaces found",
1259 		    devnum, i);
1260 	}
1261 	device = strdup(dev->name);
1262 	pcap_freealldevs(devlist);
1263 	return (device);
1264 }
1265 #endif
1266 
1267 #ifdef HAVE_PCAP_OPEN
1268 /*
1269  * Prefixes for rpcap URLs.
1270  */
1271 static char rpcap_prefix[] = "rpcap://";
1272 static char rpcap_ssl_prefix[] = "rpcaps://";
1273 #endif
1274 
1275 static pcap_t *
1276 open_interface(const char *device, netdissect_options *ndo, char *ebuf)
1277 {
1278 	pcap_t *pc;
1279 #ifdef HAVE_PCAP_CREATE
1280 	int status;
1281 	char *cp;
1282 #endif
1283 
1284 #ifdef HAVE_PCAP_OPEN
1285 	/*
1286 	 * Is this an rpcap URL?
1287 	 */
1288 	if (strncmp(device, rpcap_prefix, sizeof(rpcap_prefix) - 1) == 0 ||
1289 	    strncmp(device, rpcap_ssl_prefix, sizeof(rpcap_ssl_prefix) - 1) == 0) {
1290 		/*
1291 		 * Yes.  Open it with pcap_open().
1292 		 */
1293 		*ebuf = '\0';
1294 		pc = pcap_open(device, ndo->ndo_snaplen,
1295 		    pflag ? 0 : PCAP_OPENFLAG_PROMISCUOUS, timeout, NULL,
1296 		    ebuf);
1297 		if (pc == NULL) {
1298 			/*
1299 			 * If this failed with "No such device" or "The system
1300 			 * cannot find the device specified", that means
1301 			 * the interface doesn't exist; return NULL, so that
1302 			 * the caller can see whether the device name is
1303 			 * actually an interface index.
1304 			 */
1305 			if (strstr(ebuf, "No such device") != NULL ||
1306 			    strstr(ebuf, "The system cannot find the device specified") != NULL)
1307 				return (NULL);
1308 			error("%s", ebuf);
1309 		}
1310 		if (*ebuf)
1311 			warning("%s", ebuf);
1312 		return (pc);
1313 	}
1314 #endif /* HAVE_PCAP_OPEN */
1315 
1316 #ifdef HAVE_PCAP_CREATE
1317 	pc = pcap_create(device, ebuf);
1318 	if (pc == NULL) {
1319 		/*
1320 		 * If this failed with "No such device", that means
1321 		 * the interface doesn't exist; return NULL, so that
1322 		 * the caller can see whether the device name is
1323 		 * actually an interface index.
1324 		 */
1325 		if (strstr(ebuf, "No such device") != NULL)
1326 			return (NULL);
1327 		error("%s", ebuf);
1328 	}
1329 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1330 	if (Jflag)
1331 		show_tstamp_types_and_exit(pc, device);
1332 #endif
1333 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1334 	status = pcap_set_tstamp_precision(pc, ndo->ndo_tstamp_precision);
1335 	if (status != 0)
1336 		error("%s: Can't set %ssecond time stamp precision: %s",
1337 		    device,
1338 		    tstamp_precision_to_string(ndo->ndo_tstamp_precision),
1339 		    pcap_statustostr(status));
1340 #endif
1341 
1342 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1343 	if (immediate_mode) {
1344 		status = pcap_set_immediate_mode(pc, 1);
1345 		if (status != 0)
1346 			error("%s: Can't set immediate mode: %s",
1347 			    device, pcap_statustostr(status));
1348 	}
1349 #endif
1350 	/*
1351 	 * Is this an interface that supports monitor mode?
1352 	 */
1353 	if (pcap_can_set_rfmon(pc) == 1)
1354 		supports_monitor_mode = 1;
1355 	else
1356 		supports_monitor_mode = 0;
1357 	if (ndo->ndo_snaplen != 0) {
1358 		/*
1359 		 * A snapshot length was explicitly specified;
1360 		 * use it.
1361 		 */
1362 		status = pcap_set_snaplen(pc, ndo->ndo_snaplen);
1363 		if (status != 0)
1364 			error("%s: Can't set snapshot length: %s",
1365 			    device, pcap_statustostr(status));
1366 	}
1367 	status = pcap_set_promisc(pc, !pflag);
1368 	if (status != 0)
1369 		error("%s: Can't set promiscuous mode: %s",
1370 		    device, pcap_statustostr(status));
1371 	if (Iflag) {
1372 		status = pcap_set_rfmon(pc, 1);
1373 		if (status != 0)
1374 			error("%s: Can't set monitor mode: %s",
1375 			    device, pcap_statustostr(status));
1376 	}
1377 	status = pcap_set_timeout(pc, timeout);
1378 	if (status != 0)
1379 		error("%s: pcap_set_timeout failed: %s",
1380 		    device, pcap_statustostr(status));
1381 	if (Bflag != 0) {
1382 		status = pcap_set_buffer_size(pc, Bflag);
1383 		if (status != 0)
1384 			error("%s: Can't set buffer size: %s",
1385 			    device, pcap_statustostr(status));
1386 	}
1387 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1388 	if (jflag != -1) {
1389 		status = pcap_set_tstamp_type(pc, jflag);
1390 		if (status < 0)
1391 			error("%s: Can't set time stamp type: %s",
1392 			    device, pcap_statustostr(status));
1393 		else if (status > 0)
1394 			warning("When trying to set timestamp type '%s' on %s: %s",
1395 			    pcap_tstamp_type_val_to_name(jflag), device,
1396 			    pcap_statustostr(status));
1397 	}
1398 #endif
1399 	status = pcap_activate(pc);
1400 	if (status < 0) {
1401 		/*
1402 		 * pcap_activate() failed.
1403 		 */
1404 		cp = pcap_geterr(pc);
1405 		if (status == PCAP_ERROR)
1406 			error("%s", cp);
1407 		else if (status == PCAP_ERROR_NO_SUCH_DEVICE) {
1408 			/*
1409 			 * Return an error for our caller to handle.
1410 			 */
1411 			snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
1412 			    device, pcap_statustostr(status), cp);
1413 		} else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
1414 			error("%s: %s\n(%s)", device,
1415 			    pcap_statustostr(status), cp);
1416 #ifdef __FreeBSD__
1417 		else if (status == PCAP_ERROR_RFMON_NOTSUP &&
1418 		    strncmp(device, "wlan", 4) == 0) {
1419 			char parent[8], newdev[8];
1420 			char sysctl[32];
1421 			size_t s = sizeof(parent);
1422 
1423 			snprintf(sysctl, sizeof(sysctl),
1424 			    "net.wlan.%d.%%parent", atoi(device + 4));
1425 			sysctlbyname(sysctl, parent, &s, NULL, 0);
1426 			strlcpy(newdev, device, sizeof(newdev));
1427 			/* Suggest a new wlan device. */
1428 			/* FIXME: incrementing the index this way is not going to work well
1429 			 * when the index is 9 or greater but the only consequence in this
1430 			 * specific case would be an error message that looks a bit odd.
1431 			 */
1432 			newdev[strlen(newdev)-1]++;
1433 			error("%s is not a monitor mode VAP\n"
1434 			    "To create a new monitor mode VAP use:\n"
1435 			    "  ifconfig %s create wlandev %s wlanmode monitor\n"
1436 			    "and use %s as the tcpdump interface",
1437 			    device, newdev, parent, newdev);
1438 		}
1439 #endif
1440 		else
1441 			error("%s: %s", device,
1442 			    pcap_statustostr(status));
1443 		pcap_close(pc);
1444 		return (NULL);
1445 	} else if (status > 0) {
1446 		/*
1447 		 * pcap_activate() succeeded, but it's warning us
1448 		 * of a problem it had.
1449 		 */
1450 		cp = pcap_geterr(pc);
1451 		if (status == PCAP_WARNING)
1452 			warning("%s", cp);
1453 		else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1454 		         *cp != '\0')
1455 			warning("%s: %s\n(%s)", device,
1456 			    pcap_statustostr(status), cp);
1457 		else
1458 			warning("%s: %s", device,
1459 			    pcap_statustostr(status));
1460 	}
1461 #ifdef HAVE_PCAP_SETDIRECTION
1462 	if (Qflag != -1) {
1463 		status = pcap_setdirection(pc, Qflag);
1464 		if (status != 0)
1465 			error("%s: pcap_setdirection() failed: %s",
1466 			      device,  pcap_geterr(pc));
1467 		}
1468 #endif /* HAVE_PCAP_SETDIRECTION */
1469 #else /* HAVE_PCAP_CREATE */
1470 	*ebuf = '\0';
1471 	/*
1472 	 * If no snapshot length was specified, or a length of 0 was
1473 	 * specified, default to 256KB.
1474 	 */
1475 	if (ndo->ndo_snaplen == 0)
1476 		ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
1477 	pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, timeout, ebuf);
1478 	if (pc == NULL) {
1479 		/*
1480 		 * If this failed with "No such device", that means
1481 		 * the interface doesn't exist; return NULL, so that
1482 		 * the caller can see whether the device name is
1483 		 * actually an interface index.
1484 		 */
1485 		if (strstr(ebuf, "No such device") != NULL)
1486 			return (NULL);
1487 		error("%s", ebuf);
1488 	}
1489 	if (*ebuf)
1490 		warning("%s", ebuf);
1491 #endif /* HAVE_PCAP_CREATE */
1492 
1493 	return (pc);
1494 }
1495 
1496 int
1497 main(int argc, char **argv)
1498 {
1499 	int cnt, op, i;
1500 	bpf_u_int32 localnet = 0, netmask = 0;
1501 	char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
1502 	char *endp;
1503 	pcap_handler callback;
1504 	int dlt;
1505 	const char *dlt_name;
1506 	struct bpf_program fcode;
1507 #ifndef _WIN32
1508 	void (*oldhandler)(int);
1509 #endif
1510 	struct dump_info dumpinfo;
1511 	u_char *pcap_userdata;
1512 	char ebuf[PCAP_ERRBUF_SIZE];
1513 	char VFileLine[PATH_MAX + 1];
1514 	const char *username = NULL;
1515 #ifndef _WIN32
1516 	const char *chroot_dir = NULL;
1517 #endif
1518 	char *ret = NULL;
1519 	char *end;
1520 #ifdef HAVE_PCAP_FINDALLDEVS
1521 	pcap_if_t *devlist;
1522 	long devnum;
1523 #endif
1524 	int status;
1525 	FILE *VFile;
1526 #ifdef HAVE_CAPSICUM
1527 	cap_rights_t rights;
1528 	int cansandbox;
1529 #endif	/* HAVE_CAPSICUM */
1530 	int Oflag = 1;			/* run filter code optimizer */
1531 	int yflag_dlt = -1;
1532 	const char *yflag_dlt_name = NULL;
1533 	int print = 0;
1534 
1535 	netdissect_options Ndo;
1536 	netdissect_options *ndo = &Ndo;
1537 
1538 	/*
1539 	 * Initialize the netdissect code.
1540 	 */
1541 	if (nd_init(ebuf, sizeof(ebuf)) == -1)
1542 		error("%s", ebuf);
1543 
1544 	memset(ndo, 0, sizeof(*ndo));
1545 	ndo_set_function_pointers(ndo);
1546 
1547 	cnt = -1;
1548 	device = NULL;
1549 	infile = NULL;
1550 	RFileName = NULL;
1551 	VFileName = NULL;
1552 	VFile = NULL;
1553 	WFileName = NULL;
1554 	dlt = -1;
1555 	if ((cp = strrchr(argv[0], PATH_SEPARATOR)) != NULL)
1556 		ndo->program_name = program_name = cp + 1;
1557 	else
1558 		ndo->program_name = program_name = argv[0];
1559 
1560 #if defined(HAVE_PCAP_WSOCKINIT)
1561 	if (pcap_wsockinit() != 0)
1562 		error("Attempting to initialize Winsock failed");
1563 #elif defined(HAVE_WSOCKINIT)
1564 	if (wsockinit() != 0)
1565 		error("Attempting to initialize Winsock failed");
1566 #endif
1567 
1568 	/*
1569 	 * On platforms where the CPU doesn't support unaligned loads,
1570 	 * force unaligned accesses to abort with SIGBUS, rather than
1571 	 * being fixed up (slowly) by the OS kernel; on those platforms,
1572 	 * misaligned accesses are bugs, and we want tcpdump to crash so
1573 	 * that the bugs are reported.
1574 	 */
1575 	if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
1576 		error("%s", ebuf);
1577 
1578 	/*
1579 	 * An explicit tzset() call is usually not needed as it happens
1580 	 * implicitly the first time we call localtime() or mktime(),
1581 	 * but in some cases (sandboxing, chroot) this may be too late.
1582 	 */
1583 	tzset();
1584 
1585 	while (
1586 	    (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
1587 		switch (op) {
1588 
1589 		case 'a':
1590 			/* compatibility for old -a */
1591 			break;
1592 
1593 		case 'A':
1594 			++ndo->ndo_Aflag;
1595 			break;
1596 
1597 		case 'b':
1598 			++ndo->ndo_bflag;
1599 			break;
1600 
1601 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
1602 		case 'B':
1603 			Bflag = atoi(optarg)*1024;
1604 			if (Bflag <= 0)
1605 				error("invalid packet buffer size %s", optarg);
1606 			break;
1607 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
1608 
1609 		case 'c':
1610 			cnt = atoi(optarg);
1611 			if (cnt <= 0)
1612 				error("invalid packet count %s", optarg);
1613 			break;
1614 
1615 		case 'C':
1616 			errno = 0;
1617 #ifdef HAVE_PCAP_DUMP_FTELL64
1618 			Cflag = strtoint64_t(optarg, &endp, 10);
1619 #else
1620 			Cflag = strtol(optarg, &endp, 10);
1621 #endif
1622 			if (endp == optarg || *endp != '\0' || errno != 0
1623 			    || Cflag <= 0)
1624 				error("invalid file size %s", optarg);
1625 			/*
1626 			 * Will multiplying it by 1000000 overflow?
1627 			 */
1628 #ifdef HAVE_PCAP_DUMP_FTELL64
1629 			if (Cflag > INT64_T_CONSTANT(0x7fffffffffffffff) / 1000000)
1630 #else
1631 			if (Cflag > LONG_MAX / 1000000)
1632 #endif
1633 				error("file size %s is too large", optarg);
1634 			Cflag *= 1000000;
1635 			break;
1636 
1637 		case 'd':
1638 			++dflag;
1639 			break;
1640 
1641 #ifdef HAVE_PCAP_FINDALLDEVS
1642 		case 'D':
1643 			Dflag++;
1644 			break;
1645 #endif
1646 
1647 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1648 		case OPTION_LIST_REMOTE_INTERFACES:
1649 			remote_interfaces_source = optarg;
1650 			break;
1651 #endif
1652 
1653 		case 'L':
1654 			Lflag++;
1655 			break;
1656 
1657 		case 'e':
1658 			++ndo->ndo_eflag;
1659 			break;
1660 
1661 		case 'E':
1662 #ifndef HAVE_LIBCRYPTO
1663 			warning("crypto code not compiled in");
1664 #endif
1665 			ndo->ndo_espsecret = optarg;
1666 			break;
1667 
1668 		case 'f':
1669 			++ndo->ndo_fflag;
1670 			break;
1671 
1672 		case 'F':
1673 			infile = optarg;
1674 			break;
1675 
1676 		case 'G':
1677 			Gflag = atoi(optarg);
1678 			if (Gflag < 0)
1679 				error("invalid number of seconds %s", optarg);
1680 
1681                         /* We will create one file initially. */
1682                         Gflag_count = 0;
1683 
1684 			/* Grab the current time for rotation use. */
1685 			if ((Gflag_time = time(NULL)) == (time_t)-1) {
1686 				error("%s: can't get current time: %s",
1687 				    __func__, pcap_strerror(errno));
1688 			}
1689 			break;
1690 
1691 		case 'h':
1692 			print_usage(stdout);
1693 			exit_tcpdump(S_SUCCESS);
1694 			break;
1695 
1696 		case 'H':
1697 			++ndo->ndo_Hflag;
1698 			break;
1699 
1700 		case 'i':
1701 			device = optarg;
1702 			break;
1703 
1704 #ifdef HAVE_PCAP_CREATE
1705 		case 'I':
1706 			++Iflag;
1707 			break;
1708 #endif /* HAVE_PCAP_CREATE */
1709 
1710 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1711 		case 'j':
1712 			jflag = pcap_tstamp_type_name_to_val(optarg);
1713 			if (jflag < 0)
1714 				error("invalid time stamp type %s", optarg);
1715 			break;
1716 
1717 		case 'J':
1718 			Jflag++;
1719 			break;
1720 #endif
1721 
1722 		case 'l':
1723 #ifdef _WIN32
1724 			/*
1725 			 * _IOLBF is the same as _IOFBF in Microsoft's C
1726 			 * libraries; the only alternative they offer
1727 			 * is _IONBF.
1728 			 *
1729 			 * XXX - this should really be checking for MSVC++,
1730 			 * not _WIN32, if, for example, MinGW has its own
1731 			 * C library that is more UNIX-compatible.
1732 			 */
1733 			setvbuf(stdout, NULL, _IONBF, 0);
1734 #else /* _WIN32 */
1735 #ifdef HAVE_SETLINEBUF
1736 			setlinebuf(stdout);
1737 #else
1738 			setvbuf(stdout, NULL, _IOLBF, 0);
1739 #endif
1740 #endif /* _WIN32 */
1741 			lflag = 1;
1742 			break;
1743 
1744 		case 'K':
1745 			++ndo->ndo_Kflag;
1746 			break;
1747 
1748 		case 'm':
1749 			if (nd_have_smi_support()) {
1750 				if (nd_load_smi_module(optarg, ebuf, sizeof(ebuf)) == -1)
1751 					error("%s", ebuf);
1752 			} else {
1753 				(void)fprintf(stderr, "%s: ignoring option '-m %s' ",
1754 					      program_name, optarg);
1755 				(void)fprintf(stderr, "(no libsmi support)\n");
1756 			}
1757 			break;
1758 
1759 		case 'M':
1760 			/* TCP-MD5 shared secret */
1761 #ifndef HAVE_LIBCRYPTO
1762 			warning("crypto code not compiled in");
1763 #endif
1764 			ndo->ndo_sigsecret = optarg;
1765 			break;
1766 
1767 		case 'n':
1768 			++ndo->ndo_nflag;
1769 			break;
1770 
1771 		case 'N':
1772 			++ndo->ndo_Nflag;
1773 			break;
1774 
1775 		case 'O':
1776 			Oflag = 0;
1777 			break;
1778 
1779 		case 'p':
1780 			++pflag;
1781 			break;
1782 
1783 		case 'q':
1784 			++ndo->ndo_qflag;
1785 			++ndo->ndo_suppress_default_print;
1786 			break;
1787 
1788 #ifdef HAVE_PCAP_SETDIRECTION
1789 		case 'Q':
1790 			if (ascii_strcasecmp(optarg, "in") == 0)
1791 				Qflag = PCAP_D_IN;
1792 			else if (ascii_strcasecmp(optarg, "out") == 0)
1793 				Qflag = PCAP_D_OUT;
1794 			else if (ascii_strcasecmp(optarg, "inout") == 0)
1795 				Qflag = PCAP_D_INOUT;
1796 			else
1797 				error("unknown capture direction '%s'", optarg);
1798 			break;
1799 #endif /* HAVE_PCAP_SETDIRECTION */
1800 
1801 		case 'r':
1802 			RFileName = optarg;
1803 			break;
1804 
1805 		case 's':
1806 			ndo->ndo_snaplen = (int)strtol(optarg, &end, 0);
1807 			if (optarg == end || *end != '\0'
1808 			    || ndo->ndo_snaplen < 0 || ndo->ndo_snaplen > MAXIMUM_SNAPLEN)
1809 				error("invalid snaplen %s (must be >= 0 and <= %d)",
1810 				      optarg, MAXIMUM_SNAPLEN);
1811 			break;
1812 
1813 		case 'S':
1814 			++ndo->ndo_Sflag;
1815 			break;
1816 
1817 		case 't':
1818 			++ndo->ndo_tflag;
1819 			break;
1820 
1821 		case 'T':
1822 			if (ascii_strcasecmp(optarg, "vat") == 0)
1823 				ndo->ndo_packettype = PT_VAT;
1824 			else if (ascii_strcasecmp(optarg, "wb") == 0)
1825 				ndo->ndo_packettype = PT_WB;
1826 			else if (ascii_strcasecmp(optarg, "rpc") == 0)
1827 				ndo->ndo_packettype = PT_RPC;
1828 			else if (ascii_strcasecmp(optarg, "rtp") == 0)
1829 				ndo->ndo_packettype = PT_RTP;
1830 			else if (ascii_strcasecmp(optarg, "rtcp") == 0)
1831 				ndo->ndo_packettype = PT_RTCP;
1832 			else if (ascii_strcasecmp(optarg, "snmp") == 0)
1833 				ndo->ndo_packettype = PT_SNMP;
1834 			else if (ascii_strcasecmp(optarg, "cnfp") == 0)
1835 				ndo->ndo_packettype = PT_CNFP;
1836 			else if (ascii_strcasecmp(optarg, "tftp") == 0)
1837 				ndo->ndo_packettype = PT_TFTP;
1838 			else if (ascii_strcasecmp(optarg, "aodv") == 0)
1839 				ndo->ndo_packettype = PT_AODV;
1840 			else if (ascii_strcasecmp(optarg, "carp") == 0)
1841 				ndo->ndo_packettype = PT_CARP;
1842 			else if (ascii_strcasecmp(optarg, "radius") == 0)
1843 				ndo->ndo_packettype = PT_RADIUS;
1844 			else if (ascii_strcasecmp(optarg, "zmtp1") == 0)
1845 				ndo->ndo_packettype = PT_ZMTP1;
1846 			else if (ascii_strcasecmp(optarg, "vxlan") == 0)
1847 				ndo->ndo_packettype = PT_VXLAN;
1848 			else if (ascii_strcasecmp(optarg, "pgm") == 0)
1849 				ndo->ndo_packettype = PT_PGM;
1850 			else if (ascii_strcasecmp(optarg, "pgm_zmtp1") == 0)
1851 				ndo->ndo_packettype = PT_PGM_ZMTP1;
1852 			else if (ascii_strcasecmp(optarg, "lmp") == 0)
1853 				ndo->ndo_packettype = PT_LMP;
1854 			else if (ascii_strcasecmp(optarg, "resp") == 0)
1855 				ndo->ndo_packettype = PT_RESP;
1856 			else if (ascii_strcasecmp(optarg, "ptp") == 0)
1857 				ndo->ndo_packettype = PT_PTP;
1858 			else if (ascii_strcasecmp(optarg, "someip") == 0)
1859 				ndo->ndo_packettype = PT_SOMEIP;
1860 			else if (ascii_strcasecmp(optarg, "domain") == 0)
1861 				ndo->ndo_packettype = PT_DOMAIN;
1862 			else
1863 				error("unknown packet type '%s'", optarg);
1864 			break;
1865 
1866 		case 'u':
1867 			++ndo->ndo_uflag;
1868 			break;
1869 
1870 #ifdef HAVE_PCAP_DUMP_FLUSH
1871 		case 'U':
1872 			++Uflag;
1873 			break;
1874 #endif
1875 
1876 		case 'v':
1877 			++ndo->ndo_vflag;
1878 			break;
1879 
1880 		case 'V':
1881 			VFileName = optarg;
1882 			break;
1883 
1884 		case 'w':
1885 			WFileName = optarg;
1886 			break;
1887 
1888 		case 'W':
1889 			Wflag = atoi(optarg);
1890 			if (Wflag <= 0)
1891 				error("invalid number of output files %s", optarg);
1892 			WflagChars = getWflagChars(Wflag);
1893 			break;
1894 
1895 		case 'x':
1896 			++ndo->ndo_xflag;
1897 			++ndo->ndo_suppress_default_print;
1898 			break;
1899 
1900 		case 'X':
1901 			++ndo->ndo_Xflag;
1902 			++ndo->ndo_suppress_default_print;
1903 			break;
1904 
1905 		case 'y':
1906 			yflag_dlt_name = optarg;
1907 			yflag_dlt =
1908 				pcap_datalink_name_to_val(yflag_dlt_name);
1909 			if (yflag_dlt < 0)
1910 				error("invalid data link type %s", yflag_dlt_name);
1911 			break;
1912 
1913 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
1914 		case 'Y':
1915 			{
1916 			/* Undocumented flag */
1917 			pcap_set_parser_debug(1);
1918 			}
1919 			break;
1920 #endif
1921 		case 'z':
1922 			zflag = optarg;
1923 			break;
1924 
1925 		case 'Z':
1926 			username = optarg;
1927 			break;
1928 
1929 		case '#':
1930 			ndo->ndo_packet_number = 1;
1931 			break;
1932 
1933 		case OPTION_VERSION:
1934 			print_version(stdout);
1935 			exit_tcpdump(S_SUCCESS);
1936 			break;
1937 
1938 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1939 		case OPTION_TSTAMP_PRECISION:
1940 			ndo->ndo_tstamp_precision = tstamp_precision_from_string(optarg);
1941 			if (ndo->ndo_tstamp_precision < 0)
1942 				error("unsupported time stamp precision");
1943 			break;
1944 #endif
1945 
1946 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1947 		case OPTION_IMMEDIATE_MODE:
1948 			immediate_mode = 1;
1949 			break;
1950 #endif
1951 
1952 		case OPTION_PRINT:
1953 			print = 1;
1954 			break;
1955 
1956 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1957 		case OPTION_TSTAMP_MICRO:
1958 			ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
1959 			break;
1960 
1961 		case OPTION_TSTAMP_NANO:
1962 			ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_NANO;
1963 			break;
1964 #endif
1965 
1966 		case OPTION_FP_TYPE:
1967 			/*
1968 			 * Print out the type of floating-point arithmetic
1969 			 * we're doing; it's probably IEEE, unless somebody
1970 			 * tries to run this on a VAX, but the precision
1971 			 * may differ (e.g., it might be 32-bit, 64-bit,
1972 			 * or 80-bit).
1973 			 */
1974 			float_type_check(0x4e93312d);
1975 			return 0;
1976 
1977 		case OPTION_COUNT:
1978 			count_mode = 1;
1979 			break;
1980 
1981 		default:
1982 			print_usage(stderr);
1983 			exit_tcpdump(S_ERR_HOST_PROGRAM);
1984 			/* NOTREACHED */
1985 		}
1986 
1987 #ifdef HAVE_PCAP_FINDALLDEVS
1988 	if (Dflag)
1989 		show_devices_and_exit();
1990 #endif
1991 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1992 	if (remote_interfaces_source != NULL)
1993 		show_remote_devices_and_exit();
1994 #endif
1995 
1996 	switch (ndo->ndo_tflag) {
1997 
1998 	case 0: /* Default */
1999 	case 1: /* No time stamp */
2000 	case 2: /* Unix timeval style */
2001 	case 3: /* Microseconds/nanoseconds since previous packet */
2002 	case 4: /* Date + Default */
2003 	case 5: /* Microseconds/nanoseconds since first packet */
2004 		break;
2005 
2006 	default: /* Not supported */
2007 		error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
2008 		break;
2009 	}
2010 
2011 	if (ndo->ndo_fflag != 0 && (VFileName != NULL || RFileName != NULL))
2012 		error("-f can not be used with -V or -r");
2013 
2014 	if (VFileName != NULL && RFileName != NULL)
2015 		error("-V and -r are mutually exclusive.");
2016 
2017 	/*
2018 	 * If we're printing dissected packets to the standard output,
2019 	 * and either the standard output is a terminal or we're doing
2020 	 * "line" buffering, set the capture timeout to .1 second rather
2021 	 * than 1 second, as the user's probably expecting to see packets
2022 	 * pop up immediately shortly after they arrive.
2023 	 *
2024 	 * XXX - would there be some value appropriate for all cases,
2025 	 * based on, say, the buffer size and packet input rate?
2026 	 */
2027 	if ((WFileName == NULL || print) && (isatty(1) || lflag))
2028 		timeout = 100;
2029 
2030 #ifdef WITH_CHROOT
2031 	/* if run as root, prepare for chrooting */
2032 	if (getuid() == 0 || geteuid() == 0) {
2033 		/* future extensibility for cmd-line arguments */
2034 		if (!chroot_dir)
2035 			chroot_dir = WITH_CHROOT;
2036 	}
2037 #endif
2038 
2039 #ifdef WITH_USER
2040 	/* if run as root, prepare for dropping root privileges */
2041 	if (getuid() == 0 || geteuid() == 0) {
2042 		/* Run with '-Z root' to restore old behaviour */
2043 		if (!username)
2044 			username = WITH_USER;
2045 		else if (strcmp(username, "root") == 0)
2046 			username = NULL;
2047 	}
2048 #endif
2049 
2050 	if (RFileName != NULL || VFileName != NULL) {
2051 		/*
2052 		 * If RFileName is non-null, it's the pathname of a
2053 		 * savefile to read.  If VFileName is non-null, it's
2054 		 * the pathname of a file containing a list of pathnames
2055 		 * (one per line) of savefiles to read.
2056 		 *
2057 		 * In either case, we're reading a savefile, not doing
2058 		 * a live capture.
2059 		 */
2060 #ifndef _WIN32
2061 		/*
2062 		 * We don't need network access, so relinquish any set-UID
2063 		 * or set-GID privileges we have (if any).
2064 		 *
2065 		 * We do *not* want set-UID privileges when opening a
2066 		 * trace file, as that might let the user read other
2067 		 * people's trace files (especially if we're set-UID
2068 		 * root).
2069 		 */
2070 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
2071 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
2072 #endif /* _WIN32 */
2073 		if (VFileName != NULL) {
2074 			if (VFileName[0] == '-' && VFileName[1] == '\0')
2075 				VFile = stdin;
2076 			else
2077 				VFile = fopen(VFileName, "r");
2078 
2079 			if (VFile == NULL)
2080 				error("Unable to open file: %s\n", pcap_strerror(errno));
2081 
2082 			ret = get_next_file(VFile, VFileLine);
2083 			if (!ret)
2084 				error("Nothing in %s\n", VFileName);
2085 			RFileName = VFileLine;
2086 		}
2087 
2088 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
2089 		pd = pcap_open_offline_with_tstamp_precision(RFileName,
2090 		    ndo->ndo_tstamp_precision, ebuf);
2091 #else
2092 		pd = pcap_open_offline(RFileName, ebuf);
2093 #endif
2094 
2095 		if (pd == NULL)
2096 			error("%s", ebuf);
2097 #ifdef HAVE_CAPSICUM
2098 		cap_rights_init(&rights, CAP_READ);
2099 		if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
2100 		    errno != ENOSYS) {
2101 			error("unable to limit pcap descriptor");
2102 		}
2103 #endif
2104 		dlt = pcap_datalink(pd);
2105 		dlt_name = pcap_datalink_val_to_name(dlt);
2106 		fprintf(stderr, "reading from file %s", RFileName);
2107 		if (dlt_name == NULL) {
2108 			fprintf(stderr, ", link-type %u", dlt);
2109 		} else {
2110 			fprintf(stderr, ", link-type %s (%s)", dlt_name,
2111 				pcap_datalink_val_to_description(dlt));
2112 		}
2113 		fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2114 #ifdef DLT_LINUX_SLL2
2115 		if (dlt == DLT_LINUX_SLL2)
2116 			fprintf(stderr, "Warning: interface names might be incorrect\n");
2117 #endif
2118 	} else if (dflag && !device) {
2119 		int dump_dlt = DLT_EN10MB;
2120 		/*
2121 		 * We're dumping the compiled code without an explicit
2122 		 * device specification.  (If a device is specified, we
2123 		 * definitely want to open it to use the DLT of that device.)
2124 		 * Either default to DLT_EN10MB with a warning, or use
2125 		 * the user-specified value if supplied.
2126 		 */
2127 		/*
2128 		 * If no snapshot length was specified, or a length of 0 was
2129 		 * specified, default to 256KB.
2130 		 */
2131 		if (ndo->ndo_snaplen == 0)
2132 			ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
2133 		/*
2134 		 * If a DLT was specified with the -y flag, use that instead.
2135 		 */
2136 		if (yflag_dlt != -1)
2137 			dump_dlt = yflag_dlt;
2138 		else
2139 			fprintf(stderr, "Warning: assuming Ethernet\n");
2140 	        pd = pcap_open_dead(dump_dlt, ndo->ndo_snaplen);
2141 	} else {
2142 		/*
2143 		 * We're doing a live capture.
2144 		 */
2145 		if (device == NULL) {
2146 			/*
2147 			 * No interface was specified.  Pick one.
2148 			 */
2149 #ifdef HAVE_PCAP_FINDALLDEVS
2150 			/*
2151 			 * Find the list of interfaces, and pick
2152 			 * the first interface.
2153 			 */
2154 			if (pcap_findalldevs(&devlist, ebuf) == -1)
2155 				error("%s", ebuf);
2156 			if (devlist == NULL)
2157 				error("no interfaces available for capture");
2158 			device = strdup(devlist->name);
2159 			pcap_freealldevs(devlist);
2160 #else /* HAVE_PCAP_FINDALLDEVS */
2161 			/*
2162 			 * Use whatever interface pcap_lookupdev()
2163 			 * chooses.
2164 			 */
2165 			device = pcap_lookupdev(ebuf);
2166 			if (device == NULL)
2167 				error("%s", ebuf);
2168 #endif
2169 		}
2170 
2171 		/*
2172 		 * Try to open the interface with the specified name.
2173 		 */
2174 		pd = open_interface(device, ndo, ebuf);
2175 		if (pd == NULL) {
2176 			/*
2177 			 * That failed.  If we can get a list of
2178 			 * interfaces, and the interface name
2179 			 * is purely numeric, try to use it as
2180 			 * a 1-based index in the list of
2181 			 * interfaces.
2182 			 */
2183 #ifdef HAVE_PCAP_FINDALLDEVS
2184 			devnum = parse_interface_number(device);
2185 			if (devnum == -1) {
2186 				/*
2187 				 * It's not a number; just report
2188 				 * the open error and fail.
2189 				 */
2190 				error("%s", ebuf);
2191 			}
2192 
2193 			/*
2194 			 * OK, it's a number; try to find the
2195 			 * interface with that index, and try
2196 			 * to open it.
2197 			 *
2198 			 * find_interface_by_number() exits if it
2199 			 * couldn't be found.
2200 			 */
2201 			device = find_interface_by_number(device, devnum);
2202 			pd = open_interface(device, ndo, ebuf);
2203 			if (pd == NULL)
2204 				error("%s", ebuf);
2205 #else /* HAVE_PCAP_FINDALLDEVS */
2206 			/*
2207 			 * We can't get a list of interfaces; just
2208 			 * fail.
2209 			 */
2210 			error("%s", ebuf);
2211 #endif /* HAVE_PCAP_FINDALLDEVS */
2212 		}
2213 
2214 		/*
2215 		 * Let user own process after capture device has
2216 		 * been opened.
2217 		 */
2218 #ifndef _WIN32
2219 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
2220 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
2221 #endif /* _WIN32 */
2222 #if !defined(HAVE_PCAP_CREATE) && defined(_WIN32)
2223 		if(Bflag != 0)
2224 			if(pcap_setbuff(pd, Bflag)==-1){
2225 				error("%s", pcap_geterr(pd));
2226 			}
2227 #endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
2228 		if (Lflag)
2229 			show_dlts_and_exit(pd, device);
2230 		if (yflag_dlt >= 0) {
2231 #ifdef HAVE_PCAP_SET_DATALINK
2232 			if (pcap_set_datalink(pd, yflag_dlt) < 0)
2233 				error("%s", pcap_geterr(pd));
2234 #else
2235 			/*
2236 			 * We don't actually support changing the
2237 			 * data link type, so we only let them
2238 			 * set it to what it already is.
2239 			 */
2240 			if (yflag_dlt != pcap_datalink(pd)) {
2241 				error("%s is not one of the DLTs supported by this device\n",
2242 				      yflag_dlt_name);
2243 			}
2244 #endif
2245 			(void)fprintf(stderr, "%s: data link type %s\n",
2246 				      program_name,
2247 				      pcap_datalink_val_to_name(yflag_dlt));
2248 			(void)fflush(stderr);
2249 		}
2250 #if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK)
2251 		else {
2252 			/*
2253 			 * Attempt to set default linktype to
2254 			 * DLT_LINUX_SLL2 when capturing on the
2255 			 * "any" device.
2256 			 *
2257 			 * If the attempt fails, just quietly drive
2258 			 * on; this may be a non-Linux "any" device
2259 			 * that doesn't support DLT_LINUX_SLL2.
2260 			 */
2261 			if (strcmp(device, "any") == 0) {
2262 DIAG_OFF_WARN_UNUSED_RESULT
2263 				(void) pcap_set_datalink(pd, DLT_LINUX_SLL2);
2264 DIAG_ON_WARN_UNUSED_RESULT
2265 			}
2266 		}
2267 #endif
2268 		i = pcap_snapshot(pd);
2269 		if (ndo->ndo_snaplen < i) {
2270 			if (ndo->ndo_snaplen != 0)
2271 				warning("snaplen raised from %d to %d", ndo->ndo_snaplen, i);
2272 			ndo->ndo_snaplen = i;
2273 		} else if (ndo->ndo_snaplen > i) {
2274 			warning("snaplen lowered from %d to %d", ndo->ndo_snaplen, i);
2275 			ndo->ndo_snaplen = i;
2276 		}
2277                 if(ndo->ndo_fflag != 0) {
2278                         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
2279                                 warning("foreign (-f) flag used but: %s", ebuf);
2280                         }
2281                 }
2282 
2283 	}
2284 	if (infile)
2285 		cmdbuf = read_infile(infile);
2286 	else
2287 		cmdbuf = copy_argv(&argv[optind]);
2288 
2289 #ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
2290 	pcap_set_optimizer_debug(dflag);
2291 #endif
2292 	if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2293 		error("%s", pcap_geterr(pd));
2294 	if (dflag) {
2295 		bpf_dump(&fcode, dflag);
2296 		pcap_close(pd);
2297 		free(cmdbuf);
2298 		pcap_freecode(&fcode);
2299 		exit_tcpdump(S_SUCCESS);
2300 	}
2301 
2302 #ifdef HAVE_CASPER
2303 	if (!ndo->ndo_nflag)
2304 		capdns = capdns_setup();
2305 #endif	/* HAVE_CASPER */
2306 
2307 	init_print(ndo, localnet, netmask);
2308 
2309 #ifndef _WIN32
2310 	(void)setsignal(SIGPIPE, cleanup);
2311 	(void)setsignal(SIGTERM, cleanup);
2312 #endif /* _WIN32 */
2313 	(void)setsignal(SIGINT, cleanup);
2314 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2315 	(void)setsignal(SIGCHLD, child_cleanup);
2316 #endif
2317 	/* Cooperate with nohup(1) */
2318 #ifndef _WIN32
2319 	/*
2320 	 * In illumos /usr/include/sys/iso/signal_iso.h causes Clang to
2321 	 * generate a -Wstrict-prototypes warning here, see [1].  The
2322 	 * __illumos__ macro is available since at least GCC 11 and Clang 13,
2323 	 * see [2].
2324 	 * 1: https://www.illumos.org/issues/16344
2325 	 * 2: https://www.illumos.org/issues/13726
2326 	 */
2327 #ifdef __illumos__
2328 	DIAG_OFF_STRICT_PROTOTYPES
2329 #endif /* __illumos__ */
2330 	if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
2331 #ifdef __illumos__
2332 	DIAG_ON_STRICT_PROTOTYPES
2333 #endif /* __illumos__ */
2334 		(void)setsignal(SIGHUP, oldhandler);
2335 #endif /* _WIN32 */
2336 
2337 #ifndef _WIN32
2338 	/*
2339 	 * If a user name was specified with "-Z", attempt to switch to
2340 	 * that user's UID.  This would probably be used with sudo,
2341 	 * to allow tcpdump to be run in a special restricted
2342 	 * account (if you just want to allow users to open capture
2343 	 * devices, and can't just give users that permission,
2344 	 * you'd make tcpdump set-UID or set-GID).
2345 	 *
2346 	 * Tcpdump doesn't necessarily write only to one savefile;
2347 	 * the general only way to allow a -Z instance to write to
2348 	 * savefiles as the user under whose UID it's run, rather
2349 	 * than as the user specified with -Z, would thus be to switch
2350 	 * to the original user ID before opening a capture file and
2351 	 * then switch back to the -Z user ID after opening the savefile.
2352 	 * Switching to the -Z user ID only after opening the first
2353 	 * savefile doesn't handle the general case.
2354 	 */
2355 
2356 	if (getuid() == 0 || geteuid() == 0) {
2357 #ifdef HAVE_LIBCAP_NG
2358 		/* Initialize capng */
2359 		capng_clear(CAPNG_SELECT_BOTH);
2360 		if (username) {
2361 DIAG_OFF_ASSIGN_ENUM
2362 			capng_updatev(
2363 				CAPNG_ADD,
2364 				CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2365 				CAP_SETUID,
2366 				CAP_SETGID,
2367 				-1);
2368 DIAG_ON_ASSIGN_ENUM
2369 		}
2370 		if (chroot_dir) {
2371 DIAG_OFF_ASSIGN_ENUM
2372 			capng_update(
2373 				CAPNG_ADD,
2374 				CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2375 				CAP_SYS_CHROOT
2376 				);
2377 DIAG_ON_ASSIGN_ENUM
2378 		}
2379 
2380 		if (WFileName) {
2381 DIAG_OFF_ASSIGN_ENUM
2382 			capng_update(
2383 				CAPNG_ADD,
2384 				CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2385 				CAP_DAC_OVERRIDE
2386 				);
2387 DIAG_ON_ASSIGN_ENUM
2388 		}
2389 		capng_apply(CAPNG_SELECT_BOTH);
2390 #endif /* HAVE_LIBCAP_NG */
2391 		if (username || chroot_dir) {
2392 #ifndef HAVE_LIBCAP_NG
2393 			if (!WFileName)
2394 #endif
2395 			droproot(username, chroot_dir);
2396 		}
2397 	}
2398 #endif /* _WIN32 */
2399 
2400 	if (pcap_setfilter(pd, &fcode) < 0)
2401 		error("%s", pcap_geterr(pd));
2402 #ifdef HAVE_CAPSICUM
2403 	if (RFileName == NULL && VFileName == NULL && pcap_fileno(pd) != -1) {
2404 		static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
2405 
2406 		/*
2407 		 * The various libpcap devices use a combination of
2408 		 * read (bpf), ioctl (bpf, netmap), poll (netmap)
2409 		 * so we add the relevant access rights.
2410 		 */
2411 		cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
2412 		if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
2413 		    errno != ENOSYS) {
2414 			error("unable to limit pcap descriptor");
2415 		}
2416 		if (cap_ioctls_limit(pcap_fileno(pd), cmds,
2417 		    sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
2418 			error("unable to limit ioctls on pcap descriptor");
2419 		}
2420 	}
2421 #endif
2422 	if (WFileName) {
2423 		/* Do not exceed the default PATH_MAX for files. */
2424 		dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
2425 
2426 		if (dumpinfo.CurrentFileName == NULL)
2427 			error("malloc of dumpinfo.CurrentFileName");
2428 
2429 		/* We do not need numbering for dumpfiles if Cflag isn't set. */
2430 		if (Cflag != 0)
2431 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
2432 		else
2433 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
2434 
2435 		pdd = pcap_dump_open(pd, dumpinfo.CurrentFileName);
2436 #ifdef HAVE_LIBCAP_NG
2437 		/* Give up CAP_DAC_OVERRIDE capability.
2438 		 * Only allow it to be restored if the -C or -G flag have been
2439 		 * set since we may need to create more files later on.
2440 		 */
2441 		capng_update(
2442 			CAPNG_DROP,
2443 			(Cflag || Gflag ? 0 : CAPNG_PERMITTED)
2444 				| CAPNG_EFFECTIVE,
2445 			CAP_DAC_OVERRIDE
2446 			);
2447 		capng_apply(CAPNG_SELECT_BOTH);
2448 #endif /* HAVE_LIBCAP_NG */
2449 		if (pdd == NULL)
2450 			error("%s", pcap_geterr(pd));
2451 #ifdef HAVE_CAPSICUM
2452 		set_dumper_capsicum_rights(pdd);
2453 #endif
2454 		if (Cflag != 0 || Gflag != 0) {
2455 #ifdef HAVE_CAPSICUM
2456 			/*
2457 			 * basename() and dirname() may modify their input buffer
2458 			 * and they do since FreeBSD 12.0, but they didn't before.
2459 			 * Hence use the return value only, but always assume the
2460 			 * input buffer has been modified and would need to be
2461 			 * reset before the next use.
2462 			 */
2463 			char *WFileName_copy;
2464 
2465 			if ((WFileName_copy = strdup(WFileName)) == NULL) {
2466 				error("Unable to allocate memory for file %s",
2467 				    WFileName);
2468 			}
2469 			DIAG_OFF_C11_EXTENSIONS
2470 			dumpinfo.WFileName = strdup(basename(WFileName_copy));
2471 			DIAG_ON_C11_EXTENSIONS
2472 			if (dumpinfo.WFileName == NULL) {
2473 				error("Unable to allocate memory for file %s",
2474 				    WFileName);
2475 			}
2476 			free(WFileName_copy);
2477 
2478 			if ((WFileName_copy = strdup(WFileName)) == NULL) {
2479 				error("Unable to allocate memory for file %s",
2480 				    WFileName);
2481 			}
2482 			DIAG_OFF_C11_EXTENSIONS
2483 			char *WFileName_dirname = dirname(WFileName_copy);
2484 			DIAG_ON_C11_EXTENSIONS
2485 			dumpinfo.dirfd = open(WFileName_dirname,
2486 			    O_DIRECTORY | O_RDONLY);
2487 			if (dumpinfo.dirfd < 0) {
2488 				error("unable to open directory %s",
2489 				    WFileName_dirname);
2490 			}
2491 			free(WFileName_dirname);
2492 			free(WFileName_copy);
2493 
2494 			cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
2495 			    CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
2496 			if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
2497 			    errno != ENOSYS) {
2498 				error("unable to limit directory rights");
2499 			}
2500 			if (cap_fcntls_limit(dumpinfo.dirfd, CAP_FCNTL_GETFL) < 0 &&
2501 			    errno != ENOSYS) {
2502 				error("unable to limit dump descriptor fcntls");
2503 			}
2504 #else	/* !HAVE_CAPSICUM */
2505 			dumpinfo.WFileName = WFileName;
2506 #endif
2507 			callback = dump_packet_and_trunc;
2508 			dumpinfo.pd = pd;
2509 			dumpinfo.pdd = pdd;
2510 			pcap_userdata = (u_char *)&dumpinfo;
2511 		} else {
2512 			callback = dump_packet;
2513 			dumpinfo.WFileName = WFileName;
2514 			dumpinfo.pd = pd;
2515 			dumpinfo.pdd = pdd;
2516 			pcap_userdata = (u_char *)&dumpinfo;
2517 		}
2518 		if (print) {
2519 			dlt = pcap_datalink(pd);
2520 			ndo->ndo_if_printer = get_if_printer(dlt);
2521 			dumpinfo.ndo = ndo;
2522 		} else
2523 			dumpinfo.ndo = NULL;
2524 
2525 #ifdef HAVE_PCAP_DUMP_FLUSH
2526 		if (Uflag)
2527 			pcap_dump_flush(pdd);
2528 #endif
2529 	} else {
2530 		dlt = pcap_datalink(pd);
2531 		ndo->ndo_if_printer = get_if_printer(dlt);
2532 		callback = print_packet;
2533 		pcap_userdata = (u_char *)ndo;
2534 	}
2535 
2536 #ifdef SIGNAL_REQ_INFO
2537 	/*
2538 	 * We can't get statistics when reading from a file rather
2539 	 * than capturing from a device.
2540 	 */
2541 	if (RFileName == NULL)
2542 		(void)setsignal(SIGNAL_REQ_INFO, requestinfo);
2543 #endif
2544 #ifdef SIGNAL_FLUSH_PCAP
2545 	(void)setsignal(SIGNAL_FLUSH_PCAP, flushpcap);
2546 #endif
2547 
2548 	if (ndo->ndo_vflag > 0 && WFileName && RFileName == NULL && !print) {
2549 		/*
2550 		 * When capturing to a file, if "--print" wasn't specified,
2551 		 *"-v" means tcpdump should, once per second,
2552 		 * "v"erbosely report the number of packets captured.
2553 		 * Except when reading from a file, because -r, -w and -v
2554 		 * together used to make a corner case, in which pcap_loop()
2555 		 * errored due to EINTR (see GH #155 for details).
2556 		 */
2557 #ifdef _WIN32
2558 		/*
2559 		 * https://blogs.msdn.microsoft.com/oldnewthing/20151230-00/?p=92741
2560 		 *
2561 		 * suggests that this dates back to W2K.
2562 		 *
2563 		 * I don't know what a "long wait" is, but we'll assume
2564 		 * that printing the stats could be a "long wait".
2565 		 */
2566 		CreateTimerQueueTimer(&timer_handle, NULL,
2567 		    verbose_stats_dump, NULL, 1000, 1000,
2568 		    WT_EXECUTEDEFAULT|WT_EXECUTELONGFUNCTION);
2569 		setvbuf(stderr, NULL, _IONBF, 0);
2570 #else /* _WIN32 */
2571 		/*
2572 		 * Assume this is UN*X, and that it has setitimer(); that
2573 		 * dates back to UNIX 95.
2574 		 */
2575 		struct itimerval timer;
2576 		(void)setsignal(SIGALRM, verbose_stats_dump);
2577 		timer.it_interval.tv_sec = 1;
2578 		timer.it_interval.tv_usec = 0;
2579 		timer.it_value.tv_sec = 1;
2580 		timer.it_value.tv_usec = 1;
2581 		setitimer(ITIMER_REAL, &timer, NULL);
2582 #endif /* _WIN32 */
2583 	}
2584 
2585 	if (RFileName == NULL) {
2586 		/*
2587 		 * Live capture (if -V was specified, we set RFileName
2588 		 * to a file from the -V file).  Print a message to
2589 		 * the standard error on UN*X.
2590 		 */
2591 		if (!ndo->ndo_vflag && !WFileName) {
2592 			(void)fprintf(stderr,
2593 			    "%s: verbose output suppressed, use -v[v]... for full protocol decode\n",
2594 			    program_name);
2595 		} else
2596 			(void)fprintf(stderr, "%s: ", program_name);
2597 		dlt = pcap_datalink(pd);
2598 		dlt_name = pcap_datalink_val_to_name(dlt);
2599 		(void)fprintf(stderr, "listening on %s", device);
2600 		if (dlt_name == NULL) {
2601 			(void)fprintf(stderr, ", link-type %u", dlt);
2602 		} else {
2603 			(void)fprintf(stderr, ", link-type %s (%s)", dlt_name,
2604 				      pcap_datalink_val_to_description(dlt));
2605 		}
2606 		(void)fprintf(stderr, ", snapshot length %d bytes\n", ndo->ndo_snaplen);
2607 		(void)fflush(stderr);
2608 	}
2609 
2610 	/*
2611 	 * If a user name was specified with "-Z", attempt to switch to
2612 	 * that user's UID.  This would probably be used with sudo,
2613 	 * to allow tcpdump to be run in a special restricted
2614 	 * account (if you just want to allow users to open capture
2615 	 * devices, and can't just give users that permission,
2616 	 * you'd make tcpdump set-UID or set-GID).
2617 	 *
2618 	 * Tcpdump doesn't necessarily write only to one savefile;
2619 	 * the general only way to allow a -Z instance to write to
2620 	 * savefiles as the user under whose UID it's run, rather
2621 	 * than as the user specified with -Z, would thus be to switch
2622 	 * to the original user ID before opening a capture file and
2623 	 * then switch back to the -Z user ID after opening the savefile.
2624 	 * Switching to the -Z user ID only after opening the first
2625 	 * savefile doesn't handle the general case.
2626 	 */
2627 	if (getuid() == 0 || geteuid() == 0) {
2628 		if (username || chroot_dir)
2629 			droproot(username, chroot_dir);
2630 	}
2631 
2632 #ifdef HAVE_CAPSICUM
2633 	cansandbox = (VFileName == NULL && zflag == NULL);
2634 #ifdef HAVE_CASPER
2635 	cansandbox = (cansandbox && (ndo->ndo_nflag || capdns != NULL));
2636 #else
2637 	cansandbox = (cansandbox && ndo->ndo_nflag);
2638 #endif /* HAVE_CASPER */
2639 	cansandbox = (cansandbox && (pcap_fileno(pd) != -1 ||
2640 	    RFileName != NULL));
2641 
2642 	if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
2643 		error("unable to enter the capability mode");
2644 #endif	/* HAVE_CAPSICUM */
2645 
2646 	do {
2647 		status = pcap_loop(pd, cnt, callback, pcap_userdata);
2648 		if (WFileName == NULL) {
2649 			/*
2650 			 * We're printing packets.  Flush the printed output,
2651 			 * so it doesn't get intermingled with error output.
2652 			 */
2653 			if (status == -2) {
2654 				/*
2655 				 * We got interrupted, so perhaps we didn't
2656 				 * manage to finish a line we were printing.
2657 				 * Print an extra newline, just in case.
2658 				 */
2659 				putchar('\n');
2660 			}
2661 			(void)fflush(stdout);
2662 		}
2663                 if (status == -2) {
2664 			/*
2665 			 * We got interrupted. If we are reading multiple
2666 			 * files (via -V) set these so that we stop.
2667 			 */
2668 			VFileName = NULL;
2669 			ret = NULL;
2670 		}
2671 		if (status == -1) {
2672 			/*
2673 			 * Error.  Report it.
2674 			 */
2675 			(void)fprintf(stderr, "%s: pcap_loop: %s\n",
2676 			    program_name, pcap_geterr(pd));
2677 		}
2678 		if (RFileName == NULL) {
2679 			/*
2680 			 * We're doing a live capture.  Report the capture
2681 			 * statistics.
2682 			 */
2683 			info(1);
2684 		}
2685 		pcap_close(pd);
2686 		if (VFileName != NULL) {
2687 			ret = get_next_file(VFile, VFileLine);
2688 			if (ret) {
2689 				int new_dlt;
2690 
2691 				RFileName = VFileLine;
2692 				pd = pcap_open_offline(RFileName, ebuf);
2693 				if (pd == NULL)
2694 					error("%s", ebuf);
2695 #ifdef HAVE_CAPSICUM
2696 				cap_rights_init(&rights, CAP_READ);
2697 				if (cap_rights_limit(fileno(pcap_file(pd)),
2698 				    &rights) < 0 && errno != ENOSYS) {
2699 					error("unable to limit pcap descriptor");
2700 				}
2701 #endif
2702 				new_dlt = pcap_datalink(pd);
2703 				if (new_dlt != dlt) {
2704 					/*
2705 					 * The new file has a different
2706 					 * link-layer header type from the
2707 					 * previous one.
2708 					 */
2709 					if (WFileName != NULL) {
2710 						/*
2711 						 * We're writing raw packets
2712 						 * that match the filter to
2713 						 * a pcap file.  pcap files
2714 						 * don't support multiple
2715 						 * different link-layer
2716 						 * header types, so we fail
2717 						 * here.
2718 						 */
2719 						error("%s: new dlt does not match original", RFileName);
2720 					}
2721 
2722 					/*
2723 					 * We're printing the decoded packets;
2724 					 * switch to the new DLT.
2725 					 *
2726 					 * To do that, we need to change
2727 					 * the printer, change the DLT name,
2728 					 * and recompile the filter with
2729 					 * the new DLT.
2730 					 */
2731 					dlt = new_dlt;
2732 					ndo->ndo_if_printer = get_if_printer(dlt);
2733 					/* Free the old filter */
2734 					pcap_freecode(&fcode);
2735 					if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2736 						error("%s", pcap_geterr(pd));
2737 				}
2738 
2739 				/*
2740 				 * Set the filter on the new file.
2741 				 */
2742 				if (pcap_setfilter(pd, &fcode) < 0)
2743 					error("%s", pcap_geterr(pd));
2744 
2745 				/*
2746 				 * Report the new file.
2747 				 */
2748 				dlt_name = pcap_datalink_val_to_name(dlt);
2749 				fprintf(stderr, "reading from file %s", RFileName);
2750 				if (dlt_name == NULL) {
2751 					fprintf(stderr, ", link-type %u", dlt);
2752 				} else {
2753 					fprintf(stderr, ", link-type %s (%s)",
2754 						dlt_name,
2755 						pcap_datalink_val_to_description(dlt));
2756 				}
2757 				fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2758 			}
2759 		}
2760 	}
2761 	while (ret != NULL);
2762 
2763 	if (count_mode && RFileName != NULL)
2764 		fprintf(stdout, "%u packet%s\n", packets_captured,
2765 			PLURAL_SUFFIX(packets_captured));
2766 
2767 	free(cmdbuf);
2768 	pcap_freecode(&fcode);
2769 	exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS);
2770 }
2771 
2772 /*
2773  * Catch a signal.
2774  */
2775 static void
2776 (*setsignal (int sig, void (*func)(int)))(int)
2777 {
2778 #ifdef _WIN32
2779 	return (signal(sig, func));
2780 #else
2781 	struct sigaction old, new;
2782 
2783 	memset(&new, 0, sizeof(new));
2784 	new.sa_handler = func;
2785 	if ((sig == SIGCHLD)
2786 # ifdef SIGNAL_REQ_INFO
2787 		|| (sig == SIGNAL_REQ_INFO)
2788 # endif
2789 # ifdef SIGNAL_FLUSH_PCAP
2790 		|| (sig == SIGNAL_FLUSH_PCAP)
2791 # endif
2792 		)
2793 		new.sa_flags = SA_RESTART;
2794 	if (sigaction(sig, &new, &old) < 0)
2795 		/* The same workaround as for SIG_DFL above. */
2796 #ifdef __illumos__
2797 		DIAG_OFF_STRICT_PROTOTYPES
2798 #endif /* __illumos__ */
2799 		return (SIG_ERR);
2800 #ifdef __illumos__
2801 		DIAG_ON_STRICT_PROTOTYPES
2802 #endif /* __illumos__ */
2803 	return (old.sa_handler);
2804 #endif
2805 }
2806 
2807 /* make a clean exit on interrupts */
2808 static void
2809 cleanup(int signo _U_)
2810 {
2811 #ifdef _WIN32
2812 	if (timer_handle != INVALID_HANDLE_VALUE) {
2813 		DeleteTimerQueueTimer(NULL, timer_handle, NULL);
2814 		CloseHandle(timer_handle);
2815 		timer_handle = INVALID_HANDLE_VALUE;
2816         }
2817 #else /* _WIN32 */
2818 	struct itimerval timer;
2819 
2820 	timer.it_interval.tv_sec = 0;
2821 	timer.it_interval.tv_usec = 0;
2822 	timer.it_value.tv_sec = 0;
2823 	timer.it_value.tv_usec = 0;
2824 	setitimer(ITIMER_REAL, &timer, NULL);
2825 #endif /* _WIN32 */
2826 
2827 #ifdef HAVE_PCAP_BREAKLOOP
2828 	/*
2829 	 * We have "pcap_breakloop()"; use it, so that we do as little
2830 	 * as possible in the signal handler (it's probably not safe
2831 	 * to do anything with standard I/O streams in a signal handler -
2832 	 * the ANSI C standard doesn't say it is).
2833 	 */
2834 	pcap_breakloop(pd);
2835 #else
2836 	/*
2837 	 * We don't have "pcap_breakloop()"; this isn't safe, but
2838 	 * it's the best we can do.  Print the summary if we're
2839 	 * not reading from a savefile - i.e., if we're doing a
2840 	 * live capture - and exit.
2841 	 */
2842 	if (pd != NULL && pcap_file(pd) == NULL) {
2843 		/*
2844 		 * We got interrupted, so perhaps we didn't
2845 		 * manage to finish a line we were printing.
2846 		 * Print an extra newline, just in case.
2847 		 */
2848 		putchar('\n');
2849 		(void)fflush(stdout);
2850 		info(1);
2851 	}
2852 	exit_tcpdump(S_SUCCESS);
2853 #endif
2854 }
2855 
2856 /*
2857   On windows, we do not use a fork, so we do not care less about
2858   waiting a child processes to die
2859  */
2860 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2861 static void
2862 child_cleanup(int signo _U_)
2863 {
2864   while (waitpid(-1, NULL, WNOHANG) >= 0);
2865 }
2866 #endif /* HAVE_FORK && HAVE_VFORK */
2867 
2868 static void
2869 info(int verbose)
2870 {
2871 	struct pcap_stat stats;
2872 
2873 	/*
2874 	 * Older versions of libpcap didn't set ps_ifdrop on some
2875 	 * platforms; initialize it to 0 to handle that.
2876 	 */
2877 	stats.ps_ifdrop = 0;
2878 	if (pcap_stats(pd, &stats) < 0) {
2879 		(void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
2880 		infoprint = 0;
2881 		return;
2882 	}
2883 
2884 	if (!verbose)
2885 		fprintf(stderr, "%s: ", program_name);
2886 
2887 	(void)fprintf(stderr, "%u packet%s captured", packets_captured,
2888 	    PLURAL_SUFFIX(packets_captured));
2889 	if (!verbose)
2890 		fputs(", ", stderr);
2891 	else
2892 		putc('\n', stderr);
2893 	(void)fprintf(stderr, "%u packet%s received by filter", stats.ps_recv,
2894 	    PLURAL_SUFFIX(stats.ps_recv));
2895 	if (!verbose)
2896 		fputs(", ", stderr);
2897 	else
2898 		putc('\n', stderr);
2899 	(void)fprintf(stderr, "%u packet%s dropped by kernel", stats.ps_drop,
2900 	    PLURAL_SUFFIX(stats.ps_drop));
2901 	if (stats.ps_ifdrop != 0) {
2902 		if (!verbose)
2903 			fputs(", ", stderr);
2904 		else
2905 			putc('\n', stderr);
2906 		(void)fprintf(stderr, "%u packet%s dropped by interface\n",
2907 		    stats.ps_ifdrop, PLURAL_SUFFIX(stats.ps_ifdrop));
2908 	} else
2909 		putc('\n', stderr);
2910 	infoprint = 0;
2911 }
2912 
2913 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2914 #ifdef HAVE_FORK
2915 #define fork_subprocess() fork()
2916 #else
2917 #define fork_subprocess() vfork()
2918 #endif
2919 static void
2920 compress_savefile(const char *filename)
2921 {
2922 	pid_t child;
2923 
2924 	child = fork_subprocess();
2925 	if (child == -1) {
2926 		fprintf(stderr,
2927 			"compress_savefile: fork failed: %s\n",
2928 			pcap_strerror(errno));
2929 		return;
2930 	}
2931 	if (child != 0) {
2932 		/* Parent process. */
2933 		return;
2934 	}
2935 
2936 	/*
2937 	 * Child process.
2938 	 * Set to lowest priority so that this doesn't disturb the capture.
2939 	 */
2940 #ifdef NZERO
2941 	setpriority(PRIO_PROCESS, 0, NZERO - 1);
2942 #else
2943 	setpriority(PRIO_PROCESS, 0, 19);
2944 #endif
2945 	if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
2946 		fprintf(stderr,
2947 			"compress_savefile: execlp(%s, %s) failed: %s\n",
2948 			zflag,
2949 			filename,
2950 			pcap_strerror(errno));
2951 #ifdef HAVE_FORK
2952 	exit(S_ERR_HOST_PROGRAM);
2953 #else
2954 	_exit(S_ERR_HOST_PROGRAM);
2955 #endif
2956 }
2957 #else  /* HAVE_FORK && HAVE_VFORK */
2958 static void
2959 compress_savefile(const char *filename)
2960 {
2961 	fprintf(stderr,
2962 		"compress_savefile failed. Functionality not implemented under your system\n");
2963 }
2964 #endif /* HAVE_FORK && HAVE_VFORK */
2965 
2966 static void
2967 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2968 {
2969 	struct dump_info *dump_info;
2970 
2971 	++packets_captured;
2972 
2973 	++infodelay;
2974 
2975 	dump_info = (struct dump_info *)user;
2976 
2977 	/*
2978 	 * XXX - this won't force the file to rotate on the specified time
2979 	 * boundary, but it will rotate on the first packet received after the
2980 	 * specified Gflag number of seconds. Note: if a Gflag time boundary
2981 	 * and a Cflag size boundary coincide, the time rotation will occur
2982 	 * first thereby cancelling the Cflag boundary (since the file should
2983 	 * be 0).
2984 	 */
2985 	if (Gflag != 0) {
2986 		/* Check if it is time to rotate */
2987 		time_t t;
2988 
2989 		/* Get the current time */
2990 		if ((t = time(NULL)) == (time_t)-1) {
2991 			error("%s: can't get current_time: %s",
2992 			    __func__, pcap_strerror(errno));
2993 		}
2994 
2995 
2996 		/* If the time is greater than the specified window, rotate */
2997 		if (t - Gflag_time >= Gflag) {
2998 #ifdef HAVE_CAPSICUM
2999 			FILE *fp;
3000 			int fd;
3001 #endif
3002 
3003 			/* Update the Gflag_time */
3004 			Gflag_time = t;
3005 			/* Update Gflag_count */
3006 			Gflag_count++;
3007 			/*
3008 			 * Close the current file and open a new one.
3009 			 */
3010 			pcap_dump_close(dump_info->pdd);
3011 
3012 			/*
3013 			 * Compress the file we just closed, if the user asked for it
3014 			 */
3015 			if (zflag != NULL)
3016 				compress_savefile(dump_info->CurrentFileName);
3017 
3018 			/*
3019 			 * Check to see if we've exceeded the Wflag (when
3020 			 * not using Cflag).
3021 			 */
3022 			if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
3023 				(void)fprintf(stderr, "Maximum file limit reached: %d\n",
3024 				    Wflag);
3025 				info(1);
3026 				exit_tcpdump(S_SUCCESS);
3027 				/* NOTREACHED */
3028 			}
3029 			if (dump_info->CurrentFileName != NULL)
3030 				free(dump_info->CurrentFileName);
3031 			/* Allocate space for max filename + \0. */
3032 			dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
3033 			if (dump_info->CurrentFileName == NULL)
3034 				error("dump_packet_and_trunc: malloc");
3035 			/*
3036 			 * Gflag was set otherwise we wouldn't be here. Reset the count
3037 			 * so multiple files would end with 1,2,3 in the filename.
3038 			 * The counting is handled with the -C flow after this.
3039 			 */
3040 			Cflag_count = 0;
3041 
3042 			/*
3043 			 * This is always the first file in the Cflag
3044 			 * rotation: e.g. 0
3045 			 * We also don't need numbering if Cflag is not set.
3046 			 */
3047 			if (Cflag != 0)
3048 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
3049 				    WflagChars);
3050 			else
3051 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
3052 
3053 #ifdef HAVE_LIBCAP_NG
3054 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3055 			capng_apply(CAPNG_SELECT_BOTH);
3056 #endif /* HAVE_LIBCAP_NG */
3057 #ifdef HAVE_CAPSICUM
3058 			fd = openat(dump_info->dirfd,
3059 			    dump_info->CurrentFileName,
3060 			    O_CREAT | O_WRONLY | O_TRUNC, 0644);
3061 			if (fd < 0) {
3062 				error("unable to open file %s",
3063 				    dump_info->CurrentFileName);
3064 			}
3065 			fp = fdopen(fd, "w");
3066 			if (fp == NULL) {
3067 				error("unable to fdopen file %s",
3068 				    dump_info->CurrentFileName);
3069 			}
3070 			dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
3071 #else	/* !HAVE_CAPSICUM */
3072 			dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
3073 #endif
3074 #ifdef HAVE_LIBCAP_NG
3075 			capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3076 			capng_apply(CAPNG_SELECT_BOTH);
3077 #endif /* HAVE_LIBCAP_NG */
3078 			if (dump_info->pdd == NULL)
3079 				error("%s", pcap_geterr(pd));
3080 #ifdef HAVE_CAPSICUM
3081 			set_dumper_capsicum_rights(dump_info->pdd);
3082 #endif
3083 		}
3084 	}
3085 
3086 	/*
3087 	 * XXX - this won't prevent capture files from getting
3088 	 * larger than Cflag - the last packet written to the
3089 	 * file could put it over Cflag.
3090 	 */
3091 	if (Cflag != 0) {
3092 #ifdef HAVE_PCAP_DUMP_FTELL64
3093 		int64_t size = pcap_dump_ftell64(dump_info->pdd);
3094 #else
3095 		/*
3096 		 * XXX - this only handles a Cflag value > 2^31-1 on
3097 		 * LP64 platforms; to handle ILP32 (32-bit UN*X and
3098 		 * Windows) or LLP64 (64-bit Windows) would require
3099 		 * a version of libpcap with pcap_dump_ftell64().
3100 		 */
3101 		long size = pcap_dump_ftell(dump_info->pdd);
3102 #endif
3103 
3104 		if (size == -1)
3105 			error("ftell fails on output file");
3106 		if (size > Cflag) {
3107 #ifdef HAVE_CAPSICUM
3108 			FILE *fp;
3109 			int fd;
3110 #endif
3111 
3112 			/*
3113 			 * Close the current file and open a new one.
3114 			 */
3115 			pcap_dump_close(dump_info->pdd);
3116 
3117 			/*
3118 			 * Compress the file we just closed, if the user
3119 			 * asked for it.
3120 			 */
3121 			if (zflag != NULL)
3122 				compress_savefile(dump_info->CurrentFileName);
3123 
3124 			Cflag_count++;
3125 			if (Wflag > 0) {
3126 				if (Cflag_count >= Wflag)
3127 					Cflag_count = 0;
3128 			}
3129 			if (dump_info->CurrentFileName != NULL)
3130 				free(dump_info->CurrentFileName);
3131 			dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
3132 			if (dump_info->CurrentFileName == NULL)
3133 				error("%s: malloc", __func__);
3134 			MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
3135 #ifdef HAVE_LIBCAP_NG
3136 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3137 			capng_apply(CAPNG_SELECT_BOTH);
3138 #endif /* HAVE_LIBCAP_NG */
3139 #ifdef HAVE_CAPSICUM
3140 			fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
3141 			    O_CREAT | O_WRONLY | O_TRUNC, 0644);
3142 			if (fd < 0) {
3143 				error("unable to open file %s",
3144 				    dump_info->CurrentFileName);
3145 			}
3146 			fp = fdopen(fd, "w");
3147 			if (fp == NULL) {
3148 				error("unable to fdopen file %s",
3149 				    dump_info->CurrentFileName);
3150 			}
3151 			dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
3152 #else	/* !HAVE_CAPSICUM */
3153 			dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
3154 #endif
3155 #ifdef HAVE_LIBCAP_NG
3156 			capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3157 			capng_apply(CAPNG_SELECT_BOTH);
3158 #endif /* HAVE_LIBCAP_NG */
3159 			if (dump_info->pdd == NULL)
3160 				error("%s", pcap_geterr(pd));
3161 #ifdef HAVE_CAPSICUM
3162 			set_dumper_capsicum_rights(dump_info->pdd);
3163 #endif
3164 		}
3165 	}
3166 
3167 	pcap_dump((u_char *)dump_info->pdd, h, sp);
3168 #ifdef HAVE_PCAP_DUMP_FLUSH
3169 	if (Uflag)
3170 		pcap_dump_flush(dump_info->pdd);
3171 #endif
3172 
3173 	if (dump_info->ndo != NULL)
3174 		pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3175 
3176 	--infodelay;
3177 	if (infoprint)
3178 		info(0);
3179 }
3180 
3181 static void
3182 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3183 {
3184 	struct dump_info *dump_info;
3185 
3186 	++packets_captured;
3187 
3188 	++infodelay;
3189 
3190 	dump_info = (struct dump_info *)user;
3191 
3192 	pcap_dump((u_char *)dump_info->pdd, h, sp);
3193 #ifdef HAVE_PCAP_DUMP_FLUSH
3194 	if (Uflag)
3195 		pcap_dump_flush(dump_info->pdd);
3196 #endif
3197 
3198 	if (dump_info->ndo != NULL)
3199 		pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3200 
3201 	--infodelay;
3202 	if (infoprint)
3203 		info(0);
3204 }
3205 
3206 static void
3207 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3208 {
3209 	++packets_captured;
3210 
3211 	++infodelay;
3212 
3213 	if (!count_mode)
3214 		pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
3215 
3216 	--infodelay;
3217 	if (infoprint)
3218 		info(0);
3219 }
3220 
3221 #ifdef SIGNAL_REQ_INFO
3222 static void
3223 requestinfo(int signo _U_)
3224 {
3225 	if (infodelay)
3226 		++infoprint;
3227 	else
3228 		info(0);
3229 }
3230 #endif
3231 
3232 #ifdef SIGNAL_FLUSH_PCAP
3233 static void
3234 flushpcap(int signo _U_)
3235 {
3236 	if (pdd != NULL)
3237 		pcap_dump_flush(pdd);
3238 }
3239 #endif
3240 
3241 static void
3242 print_packets_captured (void)
3243 {
3244 	static u_int prev_packets_captured, first = 1;
3245 
3246 	if (infodelay == 0 && (first || packets_captured != prev_packets_captured)) {
3247 		fprintf(stderr, "Got %u\r", packets_captured);
3248 		first = 0;
3249 		prev_packets_captured = packets_captured;
3250 	}
3251 }
3252 
3253 /*
3254  * Called once each second in verbose mode while dumping to file
3255  */
3256 #ifdef _WIN32
3257 static void CALLBACK verbose_stats_dump(PVOID param _U_,
3258     BOOLEAN timer_fired _U_)
3259 {
3260 	print_packets_captured();
3261 }
3262 #else /* _WIN32 */
3263 static void verbose_stats_dump(int sig _U_)
3264 {
3265 	print_packets_captured();
3266 }
3267 #endif /* _WIN32 */
3268 
3269 DIAG_OFF_DEPRECATION
3270 static void
3271 print_version(FILE *f)
3272 {
3273 #ifndef HAVE_PCAP_LIB_VERSION
3274   #ifdef HAVE_PCAP_VERSION
3275 	extern char pcap_version[];
3276   #else /* HAVE_PCAP_VERSION */
3277 	static char pcap_version[] = "unknown";
3278   #endif /* HAVE_PCAP_VERSION */
3279 #endif /* HAVE_PCAP_LIB_VERSION */
3280 	const char *smi_version_string;
3281 
3282 	(void)fprintf(f, "%s version " PACKAGE_VERSION "\n", program_name);
3283 #ifdef HAVE_PCAP_LIB_VERSION
3284 	(void)fprintf(f, "%s\n", pcap_lib_version());
3285 #else /* HAVE_PCAP_LIB_VERSION */
3286 	(void)fprintf(f, "libpcap version %s\n", pcap_version);
3287 #endif /* HAVE_PCAP_LIB_VERSION */
3288 
3289 #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
3290 	(void)fprintf (f, "%s\n", SSLeay_version(SSLEAY_VERSION));
3291 #endif
3292 
3293 	smi_version_string = nd_smi_version_string();
3294 	if (smi_version_string != NULL)
3295 		(void)fprintf (f, "SMI-library: %s\n", smi_version_string);
3296 
3297 #if defined(__SANITIZE_ADDRESS__)
3298 	(void)fprintf (f, "Compiled with AddressSanitizer/GCC.\n");
3299 #elif defined(__has_feature)
3300 #  if __has_feature(address_sanitizer)
3301 	(void)fprintf (f, "Compiled with AddressSanitizer/Clang.\n");
3302 #  elif __has_feature(memory_sanitizer)
3303 	(void)fprintf (f, "Compiled with MemorySanitizer/Clang.\n");
3304 #  endif
3305 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
3306 	(void)fprintf (f, "%zu-bit build, %zu-bit time_t\n",
3307 		       sizeof(void *) * 8, sizeof(time_t) * 8);
3308 }
3309 DIAG_ON_DEPRECATION
3310 
3311 static void
3312 print_usage(FILE *f)
3313 {
3314 	print_version(f);
3315 	(void)fprintf(f,
3316 "Usage: %s [-Abd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ] [--count]\n", program_name);
3317 	(void)fprintf(f,
3318 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
3319 	(void)fprintf(f,
3320 "\t\t[ -i interface ]" IMMEDIATE_MODE_USAGE j_FLAG_USAGE "\n");
3321 #ifdef HAVE_PCAP_FINDALLDEVS_EX
3322 	(void)fprintf(f,
3323 "\t\t" LIST_REMOTE_INTERFACES_USAGE "\n");
3324 #endif
3325 #ifdef USE_LIBSMI
3326 	(void)fprintf(f,
3327 "\t\t" m_FLAG_USAGE "\n");
3328 #endif
3329 	(void)fprintf(f,
3330 "\t\t[ -M secret ] [ --number ] [ --print ]" Q_FLAG_USAGE "\n");
3331 	(void)fprintf(f,
3332 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ --version ]\n");
3333 	(void)fprintf(f,
3334 "\t\t[ -V file ] [ -w file ] [ -W filecount ] [ -y datalinktype ]\n");
3335 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
3336 	(void)fprintf(f,
3337 "\t\t[ --time-stamp-precision precision ] [ --micro ] [ --nano ]\n");
3338 #endif
3339 	(void)fprintf(f,
3340 "\t\t[ -z postrotate-command ] [ -Z user ] [ expression ]\n");
3341 }
3342