xref: /freebsd/contrib/tcpdump/tcpdump.c (revision 197731f6)
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 #ifndef lint
29 static const char copyright[] _U_ =
30     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
31 The Regents of the University of California.  All rights reserved.\n";
32 static const char rcsid[] _U_ =
33     "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.283 2008-09-25 21:45:50 guy Exp $ (LBL)";
34 #endif
35 
36 /* $FreeBSD$ */
37 
38 /*
39  * tcpdump - monitor tcp/ip traffic on an ethernet.
40  *
41  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
42  * Mercilessly hacked and occasionally improved since then via the
43  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
44  */
45 
46 #ifdef HAVE_CONFIG_H
47 #include "config.h"
48 #endif
49 
50 #include <tcpdump-stdinc.h>
51 
52 #ifdef WIN32
53 #include "getopt.h"
54 #include "w32_fzs.h"
55 extern int strcasecmp (const char *__s1, const char *__s2);
56 extern int SIZE_BUF;
57 #define off_t long
58 #define uint UINT
59 #endif /* WIN32 */
60 
61 #ifdef HAVE_SMI_H
62 #include <smi.h>
63 #endif
64 
65 #include <pcap.h>
66 #include <signal.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #include <limits.h>
71 #ifdef __FreeBSD__
72 #include <sys/capability.h>
73 #include <sys/ioccom.h>
74 #include <sys/types.h>
75 #include <sys/sysctl.h>
76 #include <net/bpf.h>
77 #include <fcntl.h>
78 #include <libgen.h>
79 #ifdef HAVE_LIBCAPSICUM
80 #include <libcapsicum.h>
81 #include <libcapsicum_dns.h>
82 #include <libcapsicum_service.h>
83 #include <nv.h>
84 #endif	/* HAVE_LIBCAPSICUM */
85 #endif	/* __FreeBSD__ */
86 #ifndef WIN32
87 #include <sys/wait.h>
88 #include <sys/resource.h>
89 #include <pwd.h>
90 #include <grp.h>
91 #include <errno.h>
92 #endif /* WIN32 */
93 
94 /* capabilities convinience library */
95 #ifdef HAVE_CAP_NG_H
96 #include <cap-ng.h>
97 #endif /* HAVE_CAP_NG_H */
98 
99 #include "netdissect.h"
100 #include "interface.h"
101 #include "addrtoname.h"
102 #include "machdep.h"
103 #include "setsignal.h"
104 #include "gmt2local.h"
105 #include "pcap-missing.h"
106 
107 #ifndef PATH_MAX
108 #define PATH_MAX 1024
109 #endif
110 
111 #ifdef SIGINFO
112 #define SIGNAL_REQ_INFO SIGINFO
113 #elif SIGUSR1
114 #define SIGNAL_REQ_INFO SIGUSR1
115 #endif
116 
117 netdissect_options Gndo;
118 netdissect_options *gndo = &Gndo;
119 
120 static int dflag;			/* print filter code */
121 static int Lflag;			/* list available data link types and exit */
122 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
123 static int Jflag;			/* list available time stamp types */
124 #endif
125 static char *zflag = NULL;		/* compress each savefile using a specified command (like gzip or bzip2) */
126 
127 static int infodelay;
128 static int infoprint;
129 
130 char *program_name;
131 
132 #ifdef HAVE_LIBCAPSICUM
133 cap_channel_t *capdns;
134 #endif
135 
136 int32_t thiszone;		/* seconds offset from gmt to local time */
137 
138 /* Forwards */
139 static RETSIGTYPE cleanup(int);
140 static RETSIGTYPE child_cleanup(int);
141 static void usage(void) __attribute__((noreturn));
142 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
143 
144 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
145 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
146 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
147 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
148 static void droproot(const char *, const char *);
149 static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
150      __attribute__ ((noreturn, format (printf, 2, 3)));
151 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
152 
153 #ifdef SIGNAL_REQ_INFO
154 RETSIGTYPE requestinfo(int);
155 #endif
156 
157 #if defined(USE_WIN32_MM_TIMER)
158   #include <MMsystem.h>
159   static UINT timer_id;
160   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
161 #elif defined(HAVE_ALARM)
162   static void verbose_stats_dump(int sig);
163 #endif
164 
165 static void info(int);
166 static u_int packets_captured;
167 
168 struct printer {
169         if_printer f;
170 	int type;
171 };
172 
173 
174 struct ndo_printer {
175         if_ndo_printer f;
176 	int type;
177 };
178 
179 
180 static struct printer printers[] = {
181 	{ arcnet_if_print,	DLT_ARCNET },
182 #ifdef DLT_ARCNET_LINUX
183 	{ arcnet_linux_if_print, DLT_ARCNET_LINUX },
184 #endif
185 	{ token_if_print,	DLT_IEEE802 },
186 #ifdef DLT_LANE8023
187 	{ lane_if_print,        DLT_LANE8023 },
188 #endif
189 #ifdef DLT_CIP
190 	{ cip_if_print,         DLT_CIP },
191 #endif
192 #ifdef DLT_ATM_CLIP
193 	{ cip_if_print,		DLT_ATM_CLIP },
194 #endif
195 	{ sl_if_print,		DLT_SLIP },
196 #ifdef DLT_SLIP_BSDOS
197 	{ sl_bsdos_if_print,	DLT_SLIP_BSDOS },
198 #endif
199 	{ ppp_if_print,		DLT_PPP },
200 #ifdef DLT_PPP_WITHDIRECTION
201 	{ ppp_if_print,		DLT_PPP_WITHDIRECTION },
202 #endif
203 #ifdef DLT_PPP_BSDOS
204 	{ ppp_bsdos_if_print,	DLT_PPP_BSDOS },
205 #endif
206 	{ fddi_if_print,	DLT_FDDI },
207 	{ null_if_print,	DLT_NULL },
208 #ifdef DLT_LOOP
209 	{ null_if_print,	DLT_LOOP },
210 #endif
211 	{ raw_if_print,		DLT_RAW },
212 	{ atm_if_print,		DLT_ATM_RFC1483 },
213 #ifdef DLT_C_HDLC
214 	{ chdlc_if_print,	DLT_C_HDLC },
215 #endif
216 #ifdef DLT_HDLC
217 	{ chdlc_if_print,	DLT_HDLC },
218 #endif
219 #ifdef DLT_PPP_SERIAL
220 	{ ppp_hdlc_if_print,	DLT_PPP_SERIAL },
221 #endif
222 #ifdef DLT_PPP_ETHER
223 	{ pppoe_if_print,	DLT_PPP_ETHER },
224 #endif
225 #ifdef DLT_LINUX_SLL
226 	{ sll_if_print,		DLT_LINUX_SLL },
227 #endif
228 #ifdef DLT_IEEE802_11
229 	{ ieee802_11_if_print,	DLT_IEEE802_11},
230 #endif
231 #ifdef DLT_LTALK
232 	{ ltalk_if_print,	DLT_LTALK },
233 #endif
234 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
235 	{ pflog_if_print,	DLT_PFLOG },
236 #endif
237 #ifdef DLT_FR
238 	{ fr_if_print,		DLT_FR },
239 #endif
240 #ifdef DLT_FRELAY
241 	{ fr_if_print,		DLT_FRELAY },
242 #endif
243 #ifdef DLT_SUNATM
244 	{ sunatm_if_print,	DLT_SUNATM },
245 #endif
246 #ifdef DLT_IP_OVER_FC
247 	{ ipfc_if_print,	DLT_IP_OVER_FC },
248 #endif
249 #ifdef DLT_PRISM_HEADER
250 	{ prism_if_print,	DLT_PRISM_HEADER },
251 #endif
252 #ifdef DLT_IEEE802_11_RADIO
253 	{ ieee802_11_radio_if_print,	DLT_IEEE802_11_RADIO },
254 #endif
255 #ifdef DLT_ENC
256 	{ enc_if_print,		DLT_ENC },
257 #endif
258 #ifdef DLT_SYMANTEC_FIREWALL
259 	{ symantec_if_print,	DLT_SYMANTEC_FIREWALL },
260 #endif
261 #ifdef DLT_APPLE_IP_OVER_IEEE1394
262 	{ ap1394_if_print,	DLT_APPLE_IP_OVER_IEEE1394 },
263 #endif
264 #ifdef DLT_IEEE802_11_RADIO_AVS
265 	{ ieee802_11_radio_avs_if_print,	DLT_IEEE802_11_RADIO_AVS },
266 #endif
267 #ifdef DLT_JUNIPER_ATM1
268 	{ juniper_atm1_print,	DLT_JUNIPER_ATM1 },
269 #endif
270 #ifdef DLT_JUNIPER_ATM2
271 	{ juniper_atm2_print,	DLT_JUNIPER_ATM2 },
272 #endif
273 #ifdef DLT_JUNIPER_MFR
274 	{ juniper_mfr_print,	DLT_JUNIPER_MFR },
275 #endif
276 #ifdef DLT_JUNIPER_MLFR
277 	{ juniper_mlfr_print,	DLT_JUNIPER_MLFR },
278 #endif
279 #ifdef DLT_JUNIPER_MLPPP
280 	{ juniper_mlppp_print,	DLT_JUNIPER_MLPPP },
281 #endif
282 #ifdef DLT_JUNIPER_PPPOE
283 	{ juniper_pppoe_print,	DLT_JUNIPER_PPPOE },
284 #endif
285 #ifdef DLT_JUNIPER_PPPOE_ATM
286 	{ juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
287 #endif
288 #ifdef DLT_JUNIPER_GGSN
289 	{ juniper_ggsn_print,	DLT_JUNIPER_GGSN },
290 #endif
291 #ifdef DLT_JUNIPER_ES
292 	{ juniper_es_print,	DLT_JUNIPER_ES },
293 #endif
294 #ifdef DLT_JUNIPER_MONITOR
295 	{ juniper_monitor_print, DLT_JUNIPER_MONITOR },
296 #endif
297 #ifdef DLT_JUNIPER_SERVICES
298 	{ juniper_services_print, DLT_JUNIPER_SERVICES },
299 #endif
300 #ifdef DLT_JUNIPER_ETHER
301 	{ juniper_ether_print,	DLT_JUNIPER_ETHER },
302 #endif
303 #ifdef DLT_JUNIPER_PPP
304 	{ juniper_ppp_print,	DLT_JUNIPER_PPP },
305 #endif
306 #ifdef DLT_JUNIPER_FRELAY
307 	{ juniper_frelay_print,	DLT_JUNIPER_FRELAY },
308 #endif
309 #ifdef DLT_JUNIPER_CHDLC
310 	{ juniper_chdlc_print,	DLT_JUNIPER_CHDLC },
311 #endif
312 #ifdef DLT_MFR
313 	{ mfr_if_print,		DLT_MFR },
314 #endif
315 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
316 	{ bt_if_print,		DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
317 #endif
318 #ifdef HAVE_PCAP_USB_H
319 #ifdef DLT_USB_LINUX
320 	{ usb_linux_48_byte_print, DLT_USB_LINUX},
321 #endif /* DLT_USB_LINUX */
322 #ifdef DLT_USB_LINUX_MMAPPED
323 	{ usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
324 #endif /* DLT_USB_LINUX_MMAPPED */
325 #endif /* HAVE_PCAP_USB_H */
326 #ifdef DLT_IPV4
327 	{ raw_if_print,		DLT_IPV4 },
328 #endif
329 #ifdef DLT_IPV6
330 	{ raw_if_print,		DLT_IPV6 },
331 #endif
332 	{ NULL,			0 },
333 };
334 
335 static struct ndo_printer ndo_printers[] = {
336 	{ ether_if_print,	DLT_EN10MB },
337 #ifdef DLT_IPNET
338 	{ ipnet_if_print,	DLT_IPNET },
339 #endif
340 #ifdef DLT_IEEE802_15_4
341 	{ ieee802_15_4_if_print, DLT_IEEE802_15_4 },
342 #endif
343 #ifdef DLT_IEEE802_15_4_NOFCS
344 	{ ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
345 #endif
346 #ifdef DLT_PPI
347 	{ ppi_if_print,		DLT_PPI },
348 #endif
349 #ifdef DLT_NETANALYZER
350 	{ netanalyzer_if_print, DLT_NETANALYZER },
351 #endif
352 #ifdef DLT_NETANALYZER_TRANSPARENT
353 	{ netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
354 #endif
355 	{ NULL,			0 },
356 };
357 
358 if_printer
359 lookup_printer(int type)
360 {
361 	struct printer *p;
362 
363 	for (p = printers; p->f; ++p)
364 		if (type == p->type)
365 			return p->f;
366 
367 	return NULL;
368 	/* NOTREACHED */
369 }
370 
371 if_ndo_printer
372 lookup_ndo_printer(int type)
373 {
374 	struct ndo_printer *p;
375 
376 	for (p = ndo_printers; p->f; ++p)
377 		if (type == p->type)
378 			return p->f;
379 
380 	return NULL;
381 	/* NOTREACHED */
382 }
383 
384 static pcap_t *pd;
385 
386 static int supports_monitor_mode;
387 
388 extern int optind;
389 extern int opterr;
390 extern char *optarg;
391 
392 struct print_info {
393         netdissect_options *ndo;
394         union {
395                 if_printer     printer;
396                 if_ndo_printer ndo_printer;
397         } p;
398         int ndo_type;
399 };
400 
401 struct dump_info {
402 	char	*WFileName;
403 	char	*CurrentFileName;
404 	pcap_t	*pd;
405 	pcap_dumper_t *p;
406 #ifdef __FreeBSD__
407 	int	dirfd;
408 #endif
409 };
410 
411 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
412 static void
413 show_tstamp_types_and_exit(const char *device, pcap_t *pd)
414 {
415 	int n_tstamp_types;
416 	int *tstamp_types = 0;
417 	const char *tstamp_type_name;
418 	int i;
419 
420 	n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
421 	if (n_tstamp_types < 0)
422 		error("%s", pcap_geterr(pd));
423 
424 	if (n_tstamp_types == 0) {
425 		fprintf(stderr, "Time stamp type cannot be set for %s\n",
426 		    device);
427 		exit(0);
428 	}
429 	fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
430 	    device);
431 	for (i = 0; i < n_tstamp_types; i++) {
432 		tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
433 		if (tstamp_type_name != NULL) {
434 			(void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
435 			    pcap_tstamp_type_val_to_description(tstamp_types[i]));
436 		} else {
437 			(void) fprintf(stderr, "  %d\n", tstamp_types[i]);
438 		}
439 	}
440 	pcap_free_tstamp_types(tstamp_types);
441 	exit(0);
442 }
443 #endif
444 
445 static void
446 show_dlts_and_exit(const char *device, pcap_t *pd)
447 {
448 	int n_dlts;
449 	int *dlts = 0;
450 	const char *dlt_name;
451 
452 	n_dlts = pcap_list_datalinks(pd, &dlts);
453 	if (n_dlts < 0)
454 		error("%s", pcap_geterr(pd));
455 	else if (n_dlts == 0 || !dlts)
456 		error("No data link types.");
457 
458 	/*
459 	 * If the interface is known to support monitor mode, indicate
460 	 * whether these are the data link types available when not in
461 	 * monitor mode, if -I wasn't specified, or when in monitor mode,
462 	 * when -I was specified (the link-layer types available in
463 	 * monitor mode might be different from the ones available when
464 	 * not in monitor mode).
465 	 */
466 	if (supports_monitor_mode)
467 		(void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
468 		    device,
469 		    Iflag ? "when in monitor mode" : "when not in monitor mode");
470 	else
471 		(void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
472 		    device);
473 
474 	while (--n_dlts >= 0) {
475 		dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
476 		if (dlt_name != NULL) {
477 			(void) fprintf(stderr, "  %s (%s)", dlt_name,
478 			    pcap_datalink_val_to_description(dlts[n_dlts]));
479 
480 			/*
481 			 * OK, does tcpdump handle that type?
482 			 */
483 			if (lookup_printer(dlts[n_dlts]) == NULL
484                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
485 				(void) fprintf(stderr, " (printing not supported)");
486 			fprintf(stderr, "\n");
487 		} else {
488 			(void) fprintf(stderr, "  DLT %d (printing not supported)\n",
489 			    dlts[n_dlts]);
490 		}
491 	}
492 #ifdef HAVE_PCAP_FREE_DATALINKS
493 	pcap_free_datalinks(dlts);
494 #endif
495 	exit(0);
496 }
497 
498 /*
499  * Set up flags that might or might not be supported depending on the
500  * version of libpcap we're using.
501  */
502 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
503 #define B_FLAG		"B:"
504 #define B_FLAG_USAGE	" [ -B size ]"
505 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
506 #define B_FLAG
507 #define B_FLAG_USAGE
508 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
509 
510 #ifdef HAVE_PCAP_CREATE
511 #define I_FLAG		"I"
512 #else /* HAVE_PCAP_CREATE */
513 #define I_FLAG
514 #endif /* HAVE_PCAP_CREATE */
515 
516 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
517 #define j_FLAG		"j:"
518 #define j_FLAG_USAGE	" [ -j tstamptype ]"
519 #define J_FLAG		"J"
520 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
521 #define j_FLAG
522 #define j_FLAG_USAGE
523 #define J_FLAG
524 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
525 
526 #ifdef HAVE_PCAP_FINDALLDEVS
527 #ifndef HAVE_PCAP_IF_T
528 #undef HAVE_PCAP_FINDALLDEVS
529 #endif
530 #endif
531 
532 #ifdef HAVE_PCAP_FINDALLDEVS
533 #define D_FLAG	"D"
534 #else
535 #define D_FLAG
536 #endif
537 
538 #ifdef HAVE_PCAP_DUMP_FLUSH
539 #define U_FLAG	"U"
540 #else
541 #define U_FLAG
542 #endif
543 
544 #ifndef WIN32
545 /* Drop root privileges and chroot if necessary */
546 static void
547 droproot(const char *username, const char *chroot_dir)
548 {
549 	struct passwd *pw = NULL;
550 
551 	if (chroot_dir && !username) {
552 		fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
553 		exit(1);
554 	}
555 
556 	pw = getpwnam(username);
557 	if (pw) {
558 		if (chroot_dir) {
559 			if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
560 				fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
561 				    chroot_dir, pcap_strerror(errno));
562 				exit(1);
563 			}
564 		}
565 #ifdef HAVE_CAP_NG_H
566 		int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
567 		if (ret < 0) {
568 			printf("error : ret %d\n", ret);
569 		}
570 		/* We don't need CAP_SETUID and CAP_SETGID */
571 		capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_SETUID);
572 		capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_SETUID);
573 		capng_update(CAPNG_DROP, CAPNG_PERMITTED, CAP_SETUID);
574 		capng_update(CAPNG_DROP, CAPNG_PERMITTED, CAP_SETUID);
575 		capng_apply(CAPNG_SELECT_BOTH);
576 
577 #else
578 		if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
579 		    setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
580 			fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
581 			    username,
582 			    (unsigned long)pw->pw_uid,
583 			    (unsigned long)pw->pw_gid,
584 			    pcap_strerror(errno));
585 			exit(1);
586 		}
587 #endif /* HAVE_CAP_NG_H */
588 	}
589 	else {
590 		fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
591 		    username);
592 		exit(1);
593 	}
594 }
595 #endif /* WIN32 */
596 
597 static int
598 getWflagChars(int x)
599 {
600 	int c = 0;
601 
602 	x -= 1;
603 	while (x > 0) {
604 		c += 1;
605 		x /= 10;
606 	}
607 
608 	return c;
609 }
610 
611 
612 static void
613 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
614 {
615         char *filename = malloc(PATH_MAX + 1);
616         if (filename == NULL)
617             error("Makefilename: malloc");
618 
619         /* Process with strftime if Gflag is set. */
620         if (Gflag != 0) {
621           struct tm *local_tm;
622 
623           /* Convert Gflag_time to a usable format */
624           if ((local_tm = localtime(&Gflag_time)) == NULL) {
625                   error("MakeTimedFilename: localtime");
626           }
627 
628           /* There's no good way to detect an error in strftime since a return
629            * value of 0 isn't necessarily failure.
630            */
631           strftime(filename, PATH_MAX, orig_name, local_tm);
632         } else {
633           strncpy(filename, orig_name, PATH_MAX);
634         }
635 
636 	if (cnt == 0 && max_chars == 0)
637 		strncpy(buffer, filename, PATH_MAX + 1);
638 	else
639 		if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
640                   /* Report an error if the filename is too large */
641                   error("too many output files or filename is too long (> %d)", PATH_MAX);
642         free(filename);
643 }
644 
645 static int tcpdump_printf(netdissect_options *ndo _U_,
646 			  const char *fmt, ...)
647 {
648 
649   va_list args;
650   int ret;
651 
652   va_start(args, fmt);
653   ret=vfprintf(stdout, fmt, args);
654   va_end(args);
655 
656   return ret;
657 }
658 
659 static struct print_info
660 get_print_info(int type)
661 {
662 	struct print_info printinfo;
663 
664 	printinfo.ndo_type = 1;
665 	printinfo.ndo = gndo;
666 	printinfo.p.ndo_printer = lookup_ndo_printer(type);
667 	if (printinfo.p.ndo_printer == NULL) {
668 		printinfo.p.printer = lookup_printer(type);
669 		printinfo.ndo_type = 0;
670 		if (printinfo.p.printer == NULL) {
671 			gndo->ndo_dltname = pcap_datalink_val_to_name(type);
672 			if (gndo->ndo_dltname != NULL)
673 				error("packet printing is not supported for link type %s: use -w",
674 				      gndo->ndo_dltname);
675 			else
676 				error("packet printing is not supported for link type %d: use -w", type);
677 		}
678 	}
679 	return (printinfo);
680 }
681 
682 static char *
683 get_next_file(FILE *VFile, char *ptr)
684 {
685 	char *ret;
686 
687 	ret = fgets(ptr, PATH_MAX, VFile);
688 	if (!ret)
689 		return NULL;
690 
691 	if (ptr[strlen(ptr) - 1] == '\n')
692 		ptr[strlen(ptr) - 1] = '\0';
693 
694 	return ret;
695 }
696 
697 #ifdef HAVE_LIBCAPSICUM
698 static cap_channel_t *
699 capdns_setup(void)
700 {
701 	cap_channel_t *capcas, *capdnsloc;
702 	const char *types[1];
703 	int families[2];
704 
705 	capcas = cap_init();
706 	if (capcas == NULL) {
707 		warning("unable to contact casperd");
708 		return (NULL);
709 	}
710 	capdnsloc = cap_service_open(capcas, "system.dns");
711 	/* Casper capability no longer needed. */
712 	cap_close(capcas);
713 	if (capdnsloc == NULL) {
714 		warning("unable to open system.dns service");
715 		return (NULL);
716 	}
717 	/* Limit system.dns to reverse DNS lookups. */
718 	types[0] = "ADDR";
719 	if (cap_dns_type_limit(capdnsloc, types, 1) < 0) {
720 		warning("unable to limit access to system.dns service");
721 		cap_close(capdnsloc);
722 		return (NULL);
723 	}
724 	families[0] = AF_INET;
725 	families[1] = AF_INET6;
726 	if (cap_dns_family_limit(capdnsloc, families, 2) < 0) {
727 		warning("unable to limit access to system.dns service");
728 		cap_close(capdnsloc);
729 		return (NULL);
730 	}
731 
732 	return (capdnsloc);
733 }
734 #endif	/* HAVE_LIBCAPSICUM */
735 
736 int
737 main(int argc, char **argv)
738 {
739 	register int cnt, op, i;
740 	bpf_u_int32 localnet, netmask;
741 	register char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
742 	pcap_handler callback;
743 	int type;
744 	int dlt;
745 	int new_dlt;
746 	const char *dlt_name;
747 	struct bpf_program fcode;
748 #ifndef WIN32
749 	RETSIGTYPE (*oldhandler)(int);
750 #endif
751 	struct print_info printinfo;
752 	struct dump_info dumpinfo;
753 	u_char *pcap_userdata;
754 	char ebuf[PCAP_ERRBUF_SIZE];
755 	char VFileLine[PATH_MAX + 1];
756 	char *username = NULL;
757 	char *chroot_dir = NULL;
758 	char *ret = NULL;
759 	char *end;
760 #ifdef HAVE_PCAP_FINDALLDEVS
761 	pcap_if_t *devpointer;
762 	int devnum;
763 #endif
764 	int status;
765 	FILE *VFile;
766 #ifdef __FreeBSD__
767 	cap_rights_t rights;
768 	int cansandbox;
769 #endif	/* __FreeBSD__ */
770 
771 #ifdef WIN32
772 	if(wsockinit() != 0) return 1;
773 #endif /* WIN32 */
774 
775 	jflag=-1;	/* not set */
776         gndo->ndo_Oflag=1;
777 	gndo->ndo_Rflag=1;
778 	gndo->ndo_dlt=-1;
779 	gndo->ndo_default_print=ndo_default_print;
780 	gndo->ndo_printf=tcpdump_printf;
781 	gndo->ndo_error=ndo_error;
782 	gndo->ndo_warning=ndo_warning;
783 	gndo->ndo_snaplen = DEFAULT_SNAPLEN;
784 
785 	cnt = -1;
786 	device = NULL;
787 	infile = NULL;
788 	RFileName = NULL;
789 	VFileName = NULL;
790 	VFile = NULL;
791 	WFileName = NULL;
792 	dlt = -1;
793 	if ((cp = strrchr(argv[0], '/')) != NULL)
794 		program_name = cp + 1;
795 	else
796 		program_name = argv[0];
797 
798 	if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
799 		error("%s", ebuf);
800 
801 #ifdef LIBSMI
802 	smiInit("tcpdump");
803 #endif
804 
805 	while (
806 	    (op = getopt(argc, argv, "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpqr:Rs:StT:u" U_FLAG "V:vw:W:xXy:Yz:Z:")) != -1)
807 		switch (op) {
808 
809 		case 'a':
810 			/* compatibility for old -a */
811 			break;
812 
813 		case 'A':
814 			++Aflag;
815 			break;
816 
817 		case 'b':
818 			++bflag;
819 			break;
820 
821 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
822 		case 'B':
823 			Bflag = atoi(optarg)*1024;
824 			if (Bflag <= 0)
825 				error("invalid packet buffer size %s", optarg);
826 			break;
827 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
828 
829 		case 'c':
830 			cnt = atoi(optarg);
831 			if (cnt <= 0)
832 				error("invalid packet count %s", optarg);
833 			break;
834 
835 		case 'C':
836 			Cflag = atoi(optarg) * 1000000;
837 			if (Cflag < 0)
838 				error("invalid file size %s", optarg);
839 			break;
840 
841 		case 'd':
842 			++dflag;
843 			break;
844 
845 #ifdef HAVE_PCAP_FINDALLDEVS
846 		case 'D':
847 			if (pcap_findalldevs(&devpointer, ebuf) < 0)
848 				error("%s", ebuf);
849 			else {
850 				for (i = 0; devpointer != 0; i++) {
851 					printf("%d.%s", i+1, devpointer->name);
852 					if (devpointer->description != NULL)
853 						printf(" (%s)", devpointer->description);
854 					printf("\n");
855 					devpointer = devpointer->next;
856 				}
857 			}
858 			return 0;
859 #endif /* HAVE_PCAP_FINDALLDEVS */
860 
861 		case 'L':
862 			Lflag++;
863 			break;
864 
865 		case 'e':
866 			++eflag;
867 			break;
868 
869 		case 'E':
870 #ifndef HAVE_LIBCRYPTO
871 			warning("crypto code not compiled in");
872 #endif
873 			gndo->ndo_espsecret = optarg;
874 			break;
875 
876 		case 'f':
877 			++fflag;
878 			break;
879 
880 		case 'F':
881 			infile = optarg;
882 			break;
883 
884 		case 'G':
885 			Gflag = atoi(optarg);
886 			if (Gflag < 0)
887 				error("invalid number of seconds %s", optarg);
888 
889                         /* We will create one file initially. */
890                         Gflag_count = 0;
891 
892 			/* Grab the current time for rotation use. */
893 			if ((Gflag_time = time(NULL)) == (time_t)-1) {
894 				error("main: can't get current time: %s",
895 				    pcap_strerror(errno));
896 			}
897 			break;
898 
899 		case 'h':
900 			usage();
901 			break;
902 
903 		case 'H':
904 			++Hflag;
905 			break;
906 
907 		case 'i':
908 			if (optarg[0] == '0' && optarg[1] == 0)
909 				error("Invalid adapter index");
910 
911 #ifdef HAVE_PCAP_FINDALLDEVS
912 			/*
913 			 * If the argument is a number, treat it as
914 			 * an index into the list of adapters, as
915 			 * printed by "tcpdump -D".
916 			 *
917 			 * This should be OK on UNIX systems, as interfaces
918 			 * shouldn't have names that begin with digits.
919 			 * It can be useful on Windows, where more than
920 			 * one interface can have the same name.
921 			 */
922 			devnum = strtol(optarg, &end, 10);
923 			if (optarg != end && *end == '\0') {
924 				if (devnum < 0)
925 					error("Invalid adapter index");
926 
927 				if (pcap_findalldevs(&devpointer, ebuf) < 0)
928 					error("%s", ebuf);
929 				else {
930 					/*
931 					 * Look for the devnum-th entry
932 					 * in the list of devices
933 					 * (1-based).
934 					 */
935 					for (i = 0;
936 					    i < devnum-1 && devpointer != NULL;
937 					    i++, devpointer = devpointer->next)
938 						;
939 					if (devpointer == NULL)
940 						error("Invalid adapter index");
941 				}
942 				device = devpointer->name;
943 				break;
944 			}
945 #endif /* HAVE_PCAP_FINDALLDEVS */
946 			device = optarg;
947 			break;
948 
949 #ifdef HAVE_PCAP_CREATE
950 		case 'I':
951 			++Iflag;
952 			break;
953 #endif /* HAVE_PCAP_CREATE */
954 
955 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
956 		case 'j':
957 			jflag = pcap_tstamp_type_name_to_val(optarg);
958 			if (jflag < 0)
959 				error("invalid time stamp type %s", optarg);
960 			break;
961 
962 		case 'J':
963 			Jflag++;
964 			break;
965 #endif
966 
967 		case 'l':
968 #ifdef WIN32
969 			/*
970 			 * _IOLBF is the same as _IOFBF in Microsoft's C
971 			 * libraries; the only alternative they offer
972 			 * is _IONBF.
973 			 *
974 			 * XXX - this should really be checking for MSVC++,
975 			 * not WIN32, if, for example, MinGW has its own
976 			 * C library that is more UNIX-compatible.
977 			 */
978 			setvbuf(stdout, NULL, _IONBF, 0);
979 #else /* WIN32 */
980 #ifdef HAVE_SETLINEBUF
981 			setlinebuf(stdout);
982 #else
983 			setvbuf(stdout, NULL, _IOLBF, 0);
984 #endif
985 #endif /* WIN32 */
986 			break;
987 
988 		case 'K':
989 			++Kflag;
990 			break;
991 
992 		case 'm':
993 #ifdef LIBSMI
994 			if (smiLoadModule(optarg) == 0) {
995 				error("could not load MIB module %s", optarg);
996 			}
997 			sflag = 1;
998 #else
999 			(void)fprintf(stderr, "%s: ignoring option `-m %s' ",
1000 				      program_name, optarg);
1001 			(void)fprintf(stderr, "(no libsmi support)\n");
1002 #endif
1003 			break;
1004 
1005 		case 'M':
1006 			/* TCP-MD5 shared secret */
1007 #ifndef HAVE_LIBCRYPTO
1008 			warning("crypto code not compiled in");
1009 #endif
1010 			sigsecret = optarg;
1011 			break;
1012 
1013 		case 'n':
1014 			++nflag;
1015 			break;
1016 
1017 		case 'N':
1018 			++Nflag;
1019 			break;
1020 
1021 		case 'O':
1022 			Oflag = 0;
1023 			break;
1024 
1025 		case 'p':
1026 			++pflag;
1027 			break;
1028 
1029 		case 'q':
1030 			++qflag;
1031 			++suppress_default_print;
1032 			break;
1033 
1034 		case 'r':
1035 			RFileName = optarg;
1036 			break;
1037 
1038 		case 'R':
1039 			Rflag = 0;
1040 			break;
1041 
1042 		case 's':
1043 			snaplen = strtol(optarg, &end, 0);
1044 			if (optarg == end || *end != '\0'
1045 			    || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
1046 				error("invalid snaplen %s", optarg);
1047 			else if (snaplen == 0)
1048 				snaplen = MAXIMUM_SNAPLEN;
1049 			break;
1050 
1051 		case 'S':
1052 			++Sflag;
1053 			break;
1054 
1055 		case 't':
1056 			++tflag;
1057 			break;
1058 
1059 		case 'T':
1060 			if (strcasecmp(optarg, "vat") == 0)
1061 				packettype = PT_VAT;
1062 			else if (strcasecmp(optarg, "wb") == 0)
1063 				packettype = PT_WB;
1064 			else if (strcasecmp(optarg, "rpc") == 0)
1065 				packettype = PT_RPC;
1066 			else if (strcasecmp(optarg, "rtp") == 0)
1067 				packettype = PT_RTP;
1068 			else if (strcasecmp(optarg, "rtcp") == 0)
1069 				packettype = PT_RTCP;
1070 			else if (strcasecmp(optarg, "snmp") == 0)
1071 				packettype = PT_SNMP;
1072 			else if (strcasecmp(optarg, "cnfp") == 0)
1073 				packettype = PT_CNFP;
1074 			else if (strcasecmp(optarg, "tftp") == 0)
1075 				packettype = PT_TFTP;
1076 			else if (strcasecmp(optarg, "aodv") == 0)
1077 				packettype = PT_AODV;
1078 			else if (strcasecmp(optarg, "carp") == 0)
1079 				packettype = PT_CARP;
1080 			else if (strcasecmp(optarg, "radius") == 0)
1081 				packettype = PT_RADIUS;
1082 			else if (strcasecmp(optarg, "zmtp1") == 0)
1083 				packettype = PT_ZMTP1;
1084 			else if (strcasecmp(optarg, "vxlan") == 0)
1085 				packettype = PT_VXLAN;
1086 			else
1087 				error("unknown packet type `%s'", optarg);
1088 			break;
1089 
1090 		case 'u':
1091 			++uflag;
1092 			break;
1093 
1094 #ifdef HAVE_PCAP_DUMP_FLUSH
1095 		case 'U':
1096 			++Uflag;
1097 			break;
1098 #endif
1099 
1100 		case 'v':
1101 			++vflag;
1102 			break;
1103 
1104 		case 'V':
1105 			VFileName = optarg;
1106 			break;
1107 
1108 		case 'w':
1109 			WFileName = optarg;
1110 			break;
1111 
1112 		case 'W':
1113 			Wflag = atoi(optarg);
1114 			if (Wflag < 0)
1115 				error("invalid number of output files %s", optarg);
1116 			WflagChars = getWflagChars(Wflag);
1117 			break;
1118 
1119 		case 'x':
1120 			++xflag;
1121 			++suppress_default_print;
1122 			break;
1123 
1124 		case 'X':
1125 			++Xflag;
1126 			++suppress_default_print;
1127 			break;
1128 
1129 		case 'y':
1130 			gndo->ndo_dltname = optarg;
1131 			gndo->ndo_dlt =
1132 			  pcap_datalink_name_to_val(gndo->ndo_dltname);
1133 			if (gndo->ndo_dlt < 0)
1134 				error("invalid data link type %s", gndo->ndo_dltname);
1135 			break;
1136 
1137 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
1138 		case 'Y':
1139 			{
1140 			/* Undocumented flag */
1141 #ifdef HAVE_PCAP_DEBUG
1142 			extern int pcap_debug;
1143 			pcap_debug = 1;
1144 #else
1145 			extern int yydebug;
1146 			yydebug = 1;
1147 #endif
1148 			}
1149 			break;
1150 #endif
1151 		case 'z':
1152 			if (optarg) {
1153 				zflag = strdup(optarg);
1154 			} else {
1155 				usage();
1156 				/* NOTREACHED */
1157 			}
1158 			break;
1159 
1160 		case 'Z':
1161 			if (optarg) {
1162 				username = strdup(optarg);
1163 			}
1164 			else {
1165 				usage();
1166 				/* NOTREACHED */
1167 			}
1168 			break;
1169 
1170 		default:
1171 			usage();
1172 			/* NOTREACHED */
1173 		}
1174 
1175 	switch (tflag) {
1176 
1177 	case 0: /* Default */
1178 	case 4: /* Default + Date*/
1179 		thiszone = gmt2local(0);
1180 		break;
1181 
1182 	case 1: /* No time stamp */
1183 	case 2: /* Unix timeval style */
1184 	case 3: /* Microseconds since previous packet */
1185         case 5: /* Microseconds since first packet */
1186 		break;
1187 
1188 	default: /* Not supported */
1189 		error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1190 		break;
1191 	}
1192 
1193 	if (fflag != 0 && (VFileName != NULL || RFileName != NULL))
1194 		error("-f can not be used with -V or -r");
1195 
1196 	if (VFileName != NULL && RFileName != NULL)
1197 		error("-V and -r are mutually exclusive.");
1198 
1199 #ifdef WITH_CHROOT
1200 	/* if run as root, prepare for chrooting */
1201 	if (getuid() == 0 || geteuid() == 0) {
1202 		/* future extensibility for cmd-line arguments */
1203 		if (!chroot_dir)
1204 			chroot_dir = WITH_CHROOT;
1205 	}
1206 #endif
1207 
1208 #ifdef WITH_USER
1209 	/* if run as root, prepare for dropping root privileges */
1210 	if (getuid() == 0 || geteuid() == 0) {
1211 		/* Run with '-Z root' to restore old behaviour */
1212 		if (!username)
1213 			username = WITH_USER;
1214 	}
1215 #endif
1216 
1217 	if (RFileName != NULL || VFileName != NULL) {
1218 		/*
1219 		 * If RFileName is non-null, it's the pathname of a
1220 		 * savefile to read.  If VFileName is non-null, it's
1221 		 * the pathname of a file containing a list of pathnames
1222 		 * (one per line) of savefiles to read.
1223 		 *
1224 		 * In either case, we're reading a savefile, not doing
1225 		 * a live capture.
1226 		 */
1227 #ifndef WIN32
1228 		/*
1229 		 * We don't need network access, so relinquish any set-UID
1230 		 * or set-GID privileges we have (if any).
1231 		 *
1232 		 * We do *not* want set-UID privileges when opening a
1233 		 * trace file, as that might let the user read other
1234 		 * people's trace files (especially if we're set-UID
1235 		 * root).
1236 		 */
1237 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1238 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
1239 #endif /* WIN32 */
1240 		if (VFileName != NULL) {
1241 			if (VFileName[0] == '-' && VFileName[1] == '\0')
1242 				VFile = stdin;
1243 			else
1244 				VFile = fopen(VFileName, "r");
1245 
1246 			if (VFile == NULL)
1247 				error("Unable to open file: %s\n", strerror(errno));
1248 
1249 			ret = get_next_file(VFile, VFileLine);
1250 			if (!ret)
1251 				error("Nothing in %s\n", VFileName);
1252 			RFileName = VFileLine;
1253 		}
1254 
1255 		pd = pcap_open_offline(RFileName, ebuf);
1256 		if (pd == NULL)
1257 			error("%s", ebuf);
1258 #ifdef __FreeBSD__
1259 		cap_rights_init(&rights, CAP_READ);
1260 		if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
1261 		    errno != ENOSYS) {
1262 			error("unable to limit pcap descriptor");
1263 		}
1264 #endif
1265 		dlt = pcap_datalink(pd);
1266 		dlt_name = pcap_datalink_val_to_name(dlt);
1267 		if (dlt_name == NULL) {
1268 			fprintf(stderr, "reading from file %s, link-type %u\n",
1269 			    RFileName, dlt);
1270 		} else {
1271 			fprintf(stderr,
1272 			    "reading from file %s, link-type %s (%s)\n",
1273 			    RFileName, dlt_name,
1274 			    pcap_datalink_val_to_description(dlt));
1275 		}
1276 		localnet = 0;
1277 		netmask = 0;
1278 	} else {
1279 		/*
1280 		 * We're doing a live capture.
1281 		 */
1282 		if (device == NULL) {
1283 			device = pcap_lookupdev(ebuf);
1284 			if (device == NULL)
1285 				error("%s", ebuf);
1286 		}
1287 #ifdef WIN32
1288 		/*
1289 		 * Print a message to the standard error on Windows.
1290 		 * XXX - why do it here, with a different message?
1291 		 */
1292 		if(strlen(device) == 1)	//we assume that an ASCII string is always longer than 1 char
1293 		{						//a Unicode string has a \0 as second byte (so strlen() is 1)
1294 			fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1295 		}
1296 		else
1297 		{
1298 			fprintf(stderr, "%s: listening on %s\n", program_name, device);
1299 		}
1300 
1301 		fflush(stderr);
1302 #endif /* WIN32 */
1303 #ifdef HAVE_PCAP_CREATE
1304 		pd = pcap_create(device, ebuf);
1305 		if (pd == NULL)
1306 			error("%s", ebuf);
1307 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1308 		if (Jflag)
1309 			show_tstamp_types_and_exit(device, pd);
1310 #endif
1311 		/*
1312 		 * Is this an interface that supports monitor mode?
1313 		 */
1314 		if (pcap_can_set_rfmon(pd) == 1)
1315 			supports_monitor_mode = 1;
1316 		else
1317 			supports_monitor_mode = 0;
1318 		status = pcap_set_snaplen(pd, snaplen);
1319 		if (status != 0)
1320 			error("%s: Can't set snapshot length: %s",
1321 			    device, pcap_statustostr(status));
1322 		status = pcap_set_promisc(pd, !pflag);
1323 		if (status != 0)
1324 			error("%s: Can't set promiscuous mode: %s",
1325 			    device, pcap_statustostr(status));
1326 		if (Iflag) {
1327 			status = pcap_set_rfmon(pd, 1);
1328 			if (status != 0)
1329 				error("%s: Can't set monitor mode: %s",
1330 				    device, pcap_statustostr(status));
1331 		}
1332 		status = pcap_set_timeout(pd, 1000);
1333 		if (status != 0)
1334 			error("%s: pcap_set_timeout failed: %s",
1335 			    device, pcap_statustostr(status));
1336 		if (Bflag != 0) {
1337 			status = pcap_set_buffer_size(pd, Bflag);
1338 			if (status != 0)
1339 				error("%s: Can't set buffer size: %s",
1340 				    device, pcap_statustostr(status));
1341 		}
1342 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1343                 if (jflag != -1) {
1344 			status = pcap_set_tstamp_type(pd, jflag);
1345 			if (status < 0)
1346 				error("%s: Can't set time stamp type: %s",
1347 			    	    device, pcap_statustostr(status));
1348 		}
1349 #endif
1350 		status = pcap_activate(pd);
1351 		if (status < 0) {
1352 			/*
1353 			 * pcap_activate() failed.
1354 			 */
1355 			cp = pcap_geterr(pd);
1356 			if (status == PCAP_ERROR)
1357 				error("%s", cp);
1358 			else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1359 			          status == PCAP_ERROR_PERM_DENIED) &&
1360 			         *cp != '\0')
1361 				error("%s: %s\n(%s)", device,
1362 				    pcap_statustostr(status), cp);
1363 #ifdef __FreeBSD__
1364 			else if (status == PCAP_ERROR_RFMON_NOTSUP &&
1365 			    strncmp(device, "wlan", 4) == 0) {
1366 				char parent[8], newdev[8];
1367 				char sysctl[32];
1368 				size_t s = sizeof(parent);
1369 
1370 				snprintf(sysctl, sizeof(sysctl),
1371 				    "net.wlan.%d.%%parent", atoi(device + 4));
1372 				sysctlbyname(sysctl, parent, &s, NULL, 0);
1373 				strlcpy(newdev, device, sizeof(newdev));
1374 				/* Suggest a new wlan device. */
1375 				newdev[strlen(newdev)-1]++;
1376 				error("%s is not a monitor mode VAP\n"
1377 				    "To create a new monitor mode VAP use:\n"
1378 				    "  ifconfig %s create wlandev %s wlanmode "
1379 				    "monitor\nand use %s as the tcpdump "
1380 				    "interface", device, newdev, parent,
1381 				    newdev);
1382 			}
1383 #endif
1384 			else
1385 				error("%s: %s", device,
1386 				    pcap_statustostr(status));
1387 		} else if (status > 0) {
1388 			/*
1389 			 * pcap_activate() succeeded, but it's warning us
1390 			 * of a problem it had.
1391 			 */
1392 			cp = pcap_geterr(pd);
1393 			if (status == PCAP_WARNING)
1394 				warning("%s", cp);
1395 			else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1396 			         *cp != '\0')
1397 				warning("%s: %s\n(%s)", device,
1398 				    pcap_statustostr(status), cp);
1399 			else
1400 				warning("%s: %s", device,
1401 				    pcap_statustostr(status));
1402 		}
1403 #else
1404 		*ebuf = '\0';
1405 		pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1406 		if (pd == NULL)
1407 			error("%s", ebuf);
1408 		else if (*ebuf)
1409 			warning("%s", ebuf);
1410 #endif /* HAVE_PCAP_CREATE */
1411 		/*
1412 		 * Let user own process after socket has been opened.
1413 		 */
1414 #ifndef WIN32
1415 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1416 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
1417 #endif /* WIN32 */
1418 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1419 		if(Bflag != 0)
1420 			if(pcap_setbuff(pd, Bflag)==-1){
1421 				error("%s", pcap_geterr(pd));
1422 			}
1423 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1424 		if (Lflag)
1425 			show_dlts_and_exit(device, pd);
1426 		if (gndo->ndo_dlt >= 0) {
1427 #ifdef HAVE_PCAP_SET_DATALINK
1428 			if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1429 				error("%s", pcap_geterr(pd));
1430 #else
1431 			/*
1432 			 * We don't actually support changing the
1433 			 * data link type, so we only let them
1434 			 * set it to what it already is.
1435 			 */
1436 			if (gndo->ndo_dlt != pcap_datalink(pd)) {
1437 				error("%s is not one of the DLTs supported by this device\n",
1438 				      gndo->ndo_dltname);
1439 			}
1440 #endif
1441 			(void)fprintf(stderr, "%s: data link type %s\n",
1442 				      program_name, gndo->ndo_dltname);
1443 			(void)fflush(stderr);
1444 		}
1445 		i = pcap_snapshot(pd);
1446 		if (snaplen < i) {
1447 			warning("snaplen raised from %d to %d", snaplen, i);
1448 			snaplen = i;
1449 		}
1450 		if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1451 			localnet = 0;
1452 			netmask = 0;
1453 			warning("%s", ebuf);
1454 		}
1455 	}
1456 	if (infile)
1457 		cmdbuf = read_infile(infile);
1458 	else
1459 		cmdbuf = copy_argv(&argv[optind]);
1460 
1461 	if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1462 		error("%s", pcap_geterr(pd));
1463 	if (dflag) {
1464 		bpf_dump(&fcode, dflag);
1465 		pcap_close(pd);
1466 		free(cmdbuf);
1467 		exit(0);
1468 	}
1469 
1470 #ifdef HAVE_LIBCAPSICUM
1471 	if (!nflag)
1472 		capdns = capdns_setup();
1473 #endif	/* HAVE_LIBCAPSICUM */
1474 
1475 	init_addrtoname(localnet, netmask);
1476         init_checksum();
1477 
1478 #ifndef WIN32
1479 	(void)setsignal(SIGPIPE, cleanup);
1480 	(void)setsignal(SIGTERM, cleanup);
1481 	(void)setsignal(SIGINT, cleanup);
1482 #endif /* WIN32 */
1483 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1484 	(void)setsignal(SIGCHLD, child_cleanup);
1485 #endif
1486 	/* Cooperate with nohup(1) */
1487 #ifndef WIN32
1488 	if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1489 		(void)setsignal(SIGHUP, oldhandler);
1490 #endif /* WIN32 */
1491 
1492 #ifndef WIN32
1493 	/*
1494 	 * If a user name was specified with "-Z", attempt to switch to
1495 	 * that user's UID.  This would probably be used with sudo,
1496 	 * to allow tcpdump to be run in a special restricted
1497 	 * account (if you just want to allow users to open capture
1498 	 * devices, and can't just give users that permission,
1499 	 * you'd make tcpdump set-UID or set-GID).
1500 	 *
1501 	 * Tcpdump doesn't necessarily write only to one savefile;
1502 	 * the general only way to allow a -Z instance to write to
1503 	 * savefiles as the user under whose UID it's run, rather
1504 	 * than as the user specified with -Z, would thus be to switch
1505 	 * to the original user ID before opening a capture file and
1506 	 * then switch back to the -Z user ID after opening the savefile.
1507 	 * Switching to the -Z user ID only after opening the first
1508 	 * savefile doesn't handle the general case.
1509 	 */
1510 
1511 #ifdef HAVE_CAP_NG_H
1512 	/* We are running as root and we will be writing to savefile */
1513 	if ((getuid() == 0 || geteuid() == 0) && WFileName) {
1514 		if (username) {
1515 			/* Drop all capabilities from effective set */
1516 			capng_clear(CAPNG_EFFECTIVE);
1517 			/* Add capabilities we will need*/
1518 			capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_SETUID);
1519 			capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_SETGID);
1520 			capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_DAC_OVERRIDE);
1521 
1522 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_SETUID);
1523 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_SETGID);
1524 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
1525 
1526 			capng_apply(CAPNG_SELECT_BOTH);
1527 		}
1528 	}
1529 #endif /* HAVE_CAP_NG_H */
1530 
1531 	if (getuid() == 0 || geteuid() == 0) {
1532 		if (username || chroot_dir)
1533 			droproot(username, chroot_dir);
1534 
1535 	}
1536 #endif /* WIN32 */
1537 
1538 	if (pcap_setfilter(pd, &fcode) < 0)
1539 		error("%s", pcap_geterr(pd));
1540 #ifdef __FreeBSD__
1541 	if (RFileName == NULL && VFileName == NULL) {
1542 		static const unsigned long cmds[] = { BIOCGSTATS };
1543 
1544 		cap_rights_init(&rights, CAP_IOCTL, CAP_READ);
1545 		if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
1546 		    errno != ENOSYS) {
1547 			error("unable to limit pcap descriptor");
1548 		}
1549 		if (cap_ioctls_limit(pcap_fileno(pd), cmds,
1550 		    sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
1551 			error("unable to limit ioctls on pcap descriptor");
1552 		}
1553 	}
1554 #endif
1555 	if (WFileName) {
1556 		pcap_dumper_t *p;
1557 		/* Do not exceed the default PATH_MAX for files. */
1558 		dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
1559 
1560 		if (dumpinfo.CurrentFileName == NULL)
1561 			error("malloc of dumpinfo.CurrentFileName");
1562 
1563 		/* We do not need numbering for dumpfiles if Cflag isn't set. */
1564 		if (Cflag != 0)
1565 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1566 		else
1567 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1568 
1569 		p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1570 #ifdef HAVE_CAP_NG_H
1571         /* Give up capabilities, clear Effective set */
1572         capng_clear(CAPNG_EFFECTIVE);
1573 #endif
1574 		if (p == NULL)
1575 			error("%s", pcap_geterr(pd));
1576 #ifdef __FreeBSD__
1577 		cap_rights_init(&rights, CAP_SEEK, CAP_WRITE);
1578 		if (cap_rights_limit(fileno(pcap_dump_file(p)), &rights) < 0 &&
1579 		    errno != ENOSYS) {
1580 			error("unable to limit dump descriptor");
1581 		}
1582 #endif
1583 		if (Cflag != 0 || Gflag != 0) {
1584 #ifdef __FreeBSD__
1585 			dumpinfo.WFileName = strdup(basename(WFileName));
1586 			dumpinfo.dirfd = open(dirname(WFileName),
1587 			    O_DIRECTORY | O_RDONLY);
1588 			if (dumpinfo.dirfd < 0) {
1589 				error("unable to open directory %s",
1590 				    dirname(WFileName));
1591 			}
1592 			cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
1593 			    CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
1594 			if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
1595 			    errno != ENOSYS) {
1596 				error("unable to limit directory rights");
1597 			}
1598 #else	/* !__FreeBSD__ */
1599 			dumpinfo.WFileName = WFileName;
1600 #endif
1601 			callback = dump_packet_and_trunc;
1602 			dumpinfo.pd = pd;
1603 			dumpinfo.p = p;
1604 			pcap_userdata = (u_char *)&dumpinfo;
1605 		} else {
1606 			callback = dump_packet;
1607 			pcap_userdata = (u_char *)p;
1608 		}
1609 #ifdef HAVE_PCAP_DUMP_FLUSH
1610 		if (Uflag)
1611 			pcap_dump_flush(p);
1612 #endif
1613 	} else {
1614 		type = pcap_datalink(pd);
1615 		printinfo = get_print_info(type);
1616 		callback = print_packet;
1617 		pcap_userdata = (u_char *)&printinfo;
1618 	}
1619 
1620 #ifdef SIGNAL_REQ_INFO
1621 	/*
1622 	 * We can't get statistics when reading from a file rather
1623 	 * than capturing from a device.
1624 	 */
1625 	if (RFileName == NULL)
1626 		(void)setsignal(SIGNAL_REQ_INFO, requestinfo);
1627 #endif
1628 
1629 	if (vflag > 0 && WFileName) {
1630 		/*
1631 		 * When capturing to a file, "-v" means tcpdump should,
1632 		 * every 10 secodns, "v"erbosely report the number of
1633 		 * packets captured.
1634 		 */
1635 #ifdef USE_WIN32_MM_TIMER
1636 		/* call verbose_stats_dump() each 1000 +/-100msec */
1637 		timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1638 		setvbuf(stderr, NULL, _IONBF, 0);
1639 #elif defined(HAVE_ALARM)
1640 		(void)setsignal(SIGALRM, verbose_stats_dump);
1641 		alarm(1);
1642 #endif
1643 	}
1644 
1645 #ifndef WIN32
1646 	if (RFileName == NULL) {
1647 		/*
1648 		 * Live capture (if -V was specified, we set RFileName
1649 		 * to a file from the -V file).  Print a message to
1650 		 * the standard error on UN*X.
1651 		 */
1652 		if (!vflag && !WFileName) {
1653 			(void)fprintf(stderr,
1654 			    "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1655 			    program_name);
1656 		} else
1657 			(void)fprintf(stderr, "%s: ", program_name);
1658 		dlt = pcap_datalink(pd);
1659 		dlt_name = pcap_datalink_val_to_name(dlt);
1660 		if (dlt_name == NULL) {
1661 			(void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1662 			    device, dlt, snaplen);
1663 		} else {
1664 			(void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1665 			    device, dlt_name,
1666 			    pcap_datalink_val_to_description(dlt), snaplen);
1667 		}
1668 		(void)fflush(stderr);
1669 	}
1670 #endif /* WIN32 */
1671 
1672 #ifdef __FreeBSD__
1673 	cansandbox = (VFileName == NULL && zflag == NULL);
1674 #ifdef HAVE_LIBCAPSICUM
1675 	cansandbox = (cansandbox && (nflag || capdns != NULL));
1676 #else
1677 	cansandbox = (cansandbox && nflag);
1678 #endif
1679 	if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
1680 		error("unable to enter the capability mode");
1681 	if (cap_sandboxed())
1682 		fprintf(stderr, "capability mode sandbox enabled\n");
1683 #endif	/* __FreeBSD__ */
1684 
1685 	do {
1686 		status = pcap_loop(pd, cnt, callback, pcap_userdata);
1687 		if (WFileName == NULL) {
1688 			/*
1689 			 * We're printing packets.  Flush the printed output,
1690 			 * so it doesn't get intermingled with error output.
1691 			 */
1692 			if (status == -2) {
1693 				/*
1694 				 * We got interrupted, so perhaps we didn't
1695 				 * manage to finish a line we were printing.
1696 				 * Print an extra newline, just in case.
1697 				 */
1698 				putchar('\n');
1699 			}
1700 			(void)fflush(stdout);
1701 		}
1702 		if (status == -1) {
1703 			/*
1704 			 * Error.  Report it.
1705 			 */
1706 			(void)fprintf(stderr, "%s: pcap_loop: %s\n",
1707 			    program_name, pcap_geterr(pd));
1708 		}
1709 		if (RFileName == NULL) {
1710 			/*
1711 			 * We're doing a live capture.  Report the capture
1712 			 * statistics.
1713 			 */
1714 			info(1);
1715 		}
1716 		pcap_close(pd);
1717 		if (VFileName != NULL) {
1718 			ret = get_next_file(VFile, VFileLine);
1719 			if (ret) {
1720 				RFileName = VFileLine;
1721 				pd = pcap_open_offline(RFileName, ebuf);
1722 				if (pd == NULL)
1723 					error("%s", ebuf);
1724 #ifdef __FreeBSD__
1725 				cap_rights_init(&rights, CAP_READ);
1726 				if (cap_rights_limit(fileno(pcap_file(pd)),
1727 				    &rights) < 0 && errno != ENOSYS) {
1728 					error("unable to limit pcap descriptor");
1729 				}
1730 #endif
1731 				new_dlt = pcap_datalink(pd);
1732 				if (WFileName && new_dlt != dlt)
1733 					error("%s: new dlt does not match original", RFileName);
1734 				printinfo = get_print_info(new_dlt);
1735 				dlt_name = pcap_datalink_val_to_name(new_dlt);
1736 				if (dlt_name == NULL) {
1737 					fprintf(stderr, "reading from file %s, link-type %u\n",
1738 					RFileName, new_dlt);
1739 				} else {
1740 					fprintf(stderr,
1741 					"reading from file %s, link-type %s (%s)\n",
1742 					RFileName, dlt_name,
1743 					pcap_datalink_val_to_description(new_dlt));
1744 				}
1745 				if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1746 					error("%s", pcap_geterr(pd));
1747 				if (pcap_setfilter(pd, &fcode) < 0)
1748 					error("%s", pcap_geterr(pd));
1749 			}
1750 		}
1751 	}
1752 	while (ret != NULL);
1753 
1754 	free(cmdbuf);
1755 	exit(status == -1 ? 1 : 0);
1756 }
1757 
1758 /* make a clean exit on interrupts */
1759 static RETSIGTYPE
1760 cleanup(int signo _U_)
1761 {
1762 #ifdef USE_WIN32_MM_TIMER
1763 	if (timer_id)
1764 		timeKillEvent(timer_id);
1765 	timer_id = 0;
1766 #elif defined(HAVE_ALARM)
1767 	alarm(0);
1768 #endif
1769 
1770 #ifdef HAVE_PCAP_BREAKLOOP
1771 	/*
1772 	 * We have "pcap_breakloop()"; use it, so that we do as little
1773 	 * as possible in the signal handler (it's probably not safe
1774 	 * to do anything with standard I/O streams in a signal handler -
1775 	 * the ANSI C standard doesn't say it is).
1776 	 */
1777 	pcap_breakloop(pd);
1778 #else
1779 	/*
1780 	 * We don't have "pcap_breakloop()"; this isn't safe, but
1781 	 * it's the best we can do.  Print the summary if we're
1782 	 * not reading from a savefile - i.e., if we're doing a
1783 	 * live capture - and exit.
1784 	 */
1785 	if (pd != NULL && pcap_file(pd) == NULL) {
1786 		/*
1787 		 * We got interrupted, so perhaps we didn't
1788 		 * manage to finish a line we were printing.
1789 		 * Print an extra newline, just in case.
1790 		 */
1791 		putchar('\n');
1792 		(void)fflush(stdout);
1793 		info(1);
1794 	}
1795 	exit(0);
1796 #endif
1797 }
1798 
1799 /*
1800   On windows, we do not use a fork, so we do not care less about
1801   waiting a child processes to die
1802  */
1803 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1804 static RETSIGTYPE
1805 child_cleanup(int signo _U_)
1806 {
1807   wait(NULL);
1808 }
1809 #endif /* HAVE_FORK && HAVE_VFORK */
1810 
1811 static void
1812 info(register int verbose)
1813 {
1814 	struct pcap_stat stat;
1815 
1816 	/*
1817 	 * Older versions of libpcap didn't set ps_ifdrop on some
1818 	 * platforms; initialize it to 0 to handle that.
1819 	 */
1820 	stat.ps_ifdrop = 0;
1821 	if (pcap_stats(pd, &stat) < 0) {
1822 		(void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1823 		infoprint = 0;
1824 		return;
1825 	}
1826 
1827 	if (!verbose)
1828 		fprintf(stderr, "%s: ", program_name);
1829 
1830 	(void)fprintf(stderr, "%u packet%s captured", packets_captured,
1831 	    PLURAL_SUFFIX(packets_captured));
1832 	if (!verbose)
1833 		fputs(", ", stderr);
1834 	else
1835 		putc('\n', stderr);
1836 	(void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
1837 	    PLURAL_SUFFIX(stat.ps_recv));
1838 	if (!verbose)
1839 		fputs(", ", stderr);
1840 	else
1841 		putc('\n', stderr);
1842 	(void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
1843 	    PLURAL_SUFFIX(stat.ps_drop));
1844 	if (stat.ps_ifdrop != 0) {
1845 		if (!verbose)
1846 			fputs(", ", stderr);
1847 		else
1848 			putc('\n', stderr);
1849 		(void)fprintf(stderr, "%u packet%s dropped by interface\n",
1850 		    stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
1851 	} else
1852 		putc('\n', stderr);
1853 	infoprint = 0;
1854 }
1855 
1856 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1857 static void
1858 compress_savefile(const char *filename)
1859 {
1860 # ifdef HAVE_FORK
1861 	if (fork())
1862 # else
1863 	if (vfork())
1864 # endif
1865 		return;
1866 	/*
1867 	 * Set to lowest priority so that this doesn't disturb the capture
1868 	 */
1869 #ifdef NZERO
1870 	setpriority(PRIO_PROCESS, 0, NZERO - 1);
1871 #else
1872 	setpriority(PRIO_PROCESS, 0, 19);
1873 #endif
1874 	if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
1875 		fprintf(stderr,
1876 			"compress_savefile:execlp(%s, %s): %s\n",
1877 			zflag,
1878 			filename,
1879 			strerror(errno));
1880 # ifdef HAVE_FORK
1881 	exit(1);
1882 # else
1883 	_exit(1);
1884 # endif
1885 }
1886 #else  /* HAVE_FORK && HAVE_VFORK */
1887 static void
1888 compress_savefile(const char *filename)
1889 {
1890 	fprintf(stderr,
1891 		"compress_savefile failed. Functionality not implemented under your system\n");
1892 }
1893 #endif /* HAVE_FORK && HAVE_VFORK */
1894 
1895 static void
1896 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1897 {
1898 	struct dump_info *dump_info;
1899 #ifdef __FreeBSD__
1900 	cap_rights_t rights;
1901 #endif
1902 
1903 	++packets_captured;
1904 
1905 	++infodelay;
1906 
1907 	dump_info = (struct dump_info *)user;
1908 
1909 	/*
1910 	 * XXX - this won't force the file to rotate on the specified time
1911 	 * boundary, but it will rotate on the first packet received after the
1912 	 * specified Gflag number of seconds. Note: if a Gflag time boundary
1913 	 * and a Cflag size boundary coincide, the time rotation will occur
1914 	 * first thereby cancelling the Cflag boundary (since the file should
1915 	 * be 0).
1916 	 */
1917 	if (Gflag != 0) {
1918 		/* Check if it is time to rotate */
1919 		time_t t;
1920 
1921 		/* Get the current time */
1922 		if ((t = time(NULL)) == (time_t)-1) {
1923 			error("dump_and_trunc_packet: can't get current_time: %s",
1924 			    pcap_strerror(errno));
1925 		}
1926 
1927 
1928 		/* If the time is greater than the specified window, rotate */
1929 		if (t - Gflag_time >= Gflag) {
1930 #ifdef __FreeBSD__
1931 			FILE *fp;
1932 			int fd;
1933 #endif
1934 
1935 			/* Update the Gflag_time */
1936 			Gflag_time = t;
1937 			/* Update Gflag_count */
1938 			Gflag_count++;
1939 			/*
1940 			 * Close the current file and open a new one.
1941 			 */
1942 			pcap_dump_close(dump_info->p);
1943 
1944 			/*
1945 			 * Compress the file we just closed, if the user asked for it
1946 			 */
1947 			if (zflag != NULL)
1948 				compress_savefile(dump_info->CurrentFileName);
1949 
1950 			/*
1951 			 * Check to see if we've exceeded the Wflag (when
1952 			 * not using Cflag).
1953 			 */
1954 			if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
1955 				(void)fprintf(stderr, "Maximum file limit reached: %d\n",
1956 				    Wflag);
1957 				exit(0);
1958 				/* NOTREACHED */
1959 			}
1960 			if (dump_info->CurrentFileName != NULL)
1961 				free(dump_info->CurrentFileName);
1962 			/* Allocate space for max filename + \0. */
1963 			dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
1964 			if (dump_info->CurrentFileName == NULL)
1965 				error("dump_packet_and_trunc: malloc");
1966 			/*
1967 			 * This is always the first file in the Cflag
1968 			 * rotation: e.g. 0
1969 			 * We also don't need numbering if Cflag is not set.
1970 			 */
1971 			if (Cflag != 0)
1972 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
1973 				    WflagChars);
1974 			else
1975 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
1976 
1977 #ifdef HAVE_CAP_NG_H
1978 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
1979 			capng_apply(CAPNG_EFFECTIVE);
1980 #endif /* HAVE_CAP_NG_H */
1981 #ifdef __FreeBSD__
1982 			fd = openat(dump_info->dirfd,
1983 			    dump_info->CurrentFileName,
1984 			    O_CREAT | O_WRONLY | O_TRUNC, 0644);
1985 			if (fd < 0) {
1986 				error("unable to open file %s",
1987 				    dump_info->CurrentFileName);
1988 			}
1989 			fp = fdopen(fd, "w");
1990 			if (fp == NULL) {
1991 				error("unable to fdopen file %s",
1992 				    dump_info->CurrentFileName);
1993 			}
1994 			dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
1995 #else	/* !__FreeBSD__ */
1996 			dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1997 #endif
1998 #ifdef HAVE_CAP_NG_H
1999 			capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2000 			capng_apply(CAPNG_EFFECTIVE);
2001 #endif /* HAVE_CAP_NG_H */
2002 			if (dump_info->p == NULL)
2003 				error("%s", pcap_geterr(pd));
2004 #ifdef __FreeBSD__
2005 			cap_rights_init(&rights, CAP_SEEK, CAP_WRITE);
2006 			if (cap_rights_limit(fileno(pcap_dump_file(dump_info->p)),
2007 			    &rights) < 0 && errno != ENOSYS) {
2008 				error("unable to limit dump descriptor");
2009 			}
2010 #endif
2011 		}
2012 	}
2013 
2014 	/*
2015 	 * XXX - this won't prevent capture files from getting
2016 	 * larger than Cflag - the last packet written to the
2017 	 * file could put it over Cflag.
2018 	 */
2019 	if (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) {
2020 #ifdef __FreeBSD__
2021 		FILE *fp;
2022 		int fd;
2023 #endif
2024 
2025 		/*
2026 		 * Close the current file and open a new one.
2027 		 */
2028 		pcap_dump_close(dump_info->p);
2029 
2030 		/*
2031 		 * Compress the file we just closed, if the user asked for it
2032 		 */
2033 		if (zflag != NULL)
2034 			compress_savefile(dump_info->CurrentFileName);
2035 
2036 		Cflag_count++;
2037 		if (Wflag > 0) {
2038 			if (Cflag_count >= Wflag)
2039 				Cflag_count = 0;
2040 		}
2041 		if (dump_info->CurrentFileName != NULL)
2042 			free(dump_info->CurrentFileName);
2043 		dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2044 		if (dump_info->CurrentFileName == NULL)
2045 			error("dump_packet_and_trunc: malloc");
2046 		MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
2047 #ifdef __FreeBSD__
2048 		fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
2049 		    O_CREAT | O_WRONLY | O_TRUNC, 0644);
2050 		if (fd < 0) {
2051 			error("unable to open file %s",
2052 			    dump_info->CurrentFileName);
2053 		}
2054 		fp = fdopen(fd, "w");
2055 		if (fp == NULL) {
2056 			error("unable to fdopen file %s",
2057 			    dump_info->CurrentFileName);
2058 		}
2059 		dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2060 #else	/* !__FreeBSD__ */
2061 		dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2062 #endif
2063 		if (dump_info->p == NULL)
2064 			error("%s", pcap_geterr(pd));
2065 #ifdef __FreeBSD__
2066 		cap_rights_init(&rights, CAP_SEEK, CAP_WRITE);
2067 		if (cap_rights_limit(fileno(pcap_dump_file(dump_info->p)),
2068 		    &rights) < 0 && errno != ENOSYS) {
2069 			error("unable to limit dump descriptor");
2070 		}
2071 #endif
2072 	}
2073 
2074 	pcap_dump((u_char *)dump_info->p, h, sp);
2075 #ifdef HAVE_PCAP_DUMP_FLUSH
2076 	if (Uflag)
2077 		pcap_dump_flush(dump_info->p);
2078 #endif
2079 
2080 	--infodelay;
2081 	if (infoprint)
2082 		info(0);
2083 }
2084 
2085 static void
2086 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2087 {
2088 	++packets_captured;
2089 
2090 	++infodelay;
2091 
2092 	pcap_dump(user, h, sp);
2093 #ifdef HAVE_PCAP_DUMP_FLUSH
2094 	if (Uflag)
2095 		pcap_dump_flush((pcap_dumper_t *)user);
2096 #endif
2097 
2098 	--infodelay;
2099 	if (infoprint)
2100 		info(0);
2101 }
2102 
2103 static void
2104 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2105 {
2106 	struct print_info *print_info;
2107 	u_int hdrlen;
2108 
2109 	++packets_captured;
2110 
2111 	++infodelay;
2112 	ts_print(&h->ts);
2113 
2114 	print_info = (struct print_info *)user;
2115 
2116 	/*
2117 	 * Some printers want to check that they're not walking off the
2118 	 * end of the packet.
2119 	 * Rather than pass it all the way down, we set this global.
2120 	 */
2121 	snapend = sp + h->caplen;
2122 
2123         if(print_info->ndo_type) {
2124                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
2125         } else {
2126                 hdrlen = (*print_info->p.printer)(h, sp);
2127         }
2128 
2129 	if (Xflag) {
2130 		/*
2131 		 * Print the raw packet data in hex and ASCII.
2132 		 */
2133 		if (Xflag > 1) {
2134 			/*
2135 			 * Include the link-layer header.
2136 			 */
2137 			hex_and_ascii_print("\n\t", sp, h->caplen);
2138 		} else {
2139 			/*
2140 			 * Don't include the link-layer header - and if
2141 			 * we have nothing past the link-layer header,
2142 			 * print nothing.
2143 			 */
2144 			if (h->caplen > hdrlen)
2145 				hex_and_ascii_print("\n\t", sp + hdrlen,
2146 				    h->caplen - hdrlen);
2147 		}
2148 	} else if (xflag) {
2149 		/*
2150 		 * Print the raw packet data in hex.
2151 		 */
2152 		if (xflag > 1) {
2153 			/*
2154 			 * Include the link-layer header.
2155 			 */
2156 			hex_print("\n\t", sp, h->caplen);
2157 		} else {
2158 			/*
2159 			 * Don't include the link-layer header - and if
2160 			 * we have nothing past the link-layer header,
2161 			 * print nothing.
2162 			 */
2163 			if (h->caplen > hdrlen)
2164 				hex_print("\n\t", sp + hdrlen,
2165 				    h->caplen - hdrlen);
2166 		}
2167 	} else if (Aflag) {
2168 		/*
2169 		 * Print the raw packet data in ASCII.
2170 		 */
2171 		if (Aflag > 1) {
2172 			/*
2173 			 * Include the link-layer header.
2174 			 */
2175 			ascii_print(sp, h->caplen);
2176 		} else {
2177 			/*
2178 			 * Don't include the link-layer header - and if
2179 			 * we have nothing past the link-layer header,
2180 			 * print nothing.
2181 			 */
2182 			if (h->caplen > hdrlen)
2183 				ascii_print(sp + hdrlen, h->caplen - hdrlen);
2184 		}
2185 	}
2186 
2187 	putchar('\n');
2188 
2189 	--infodelay;
2190 	if (infoprint)
2191 		info(0);
2192 }
2193 
2194 #ifdef WIN32
2195 	/*
2196 	 * XXX - there should really be libpcap calls to get the version
2197 	 * number as a string (the string would be generated from #defines
2198 	 * at run time, so that it's not generated from string constants
2199 	 * in the library, as, on many UNIX systems, those constants would
2200 	 * be statically linked into the application executable image, and
2201 	 * would thus reflect the version of libpcap on the system on
2202 	 * which the application was *linked*, not the system on which it's
2203 	 * *running*.
2204 	 *
2205 	 * That routine should be documented, unlike the "version[]"
2206 	 * string, so that UNIX vendors providing their own libpcaps
2207 	 * don't omit it (as a couple of vendors have...).
2208 	 *
2209 	 * Packet.dll should perhaps also export a routine to return the
2210 	 * version number of the Packet.dll code, to supply the
2211 	 * "Wpcap_version" information on Windows.
2212 	 */
2213 	char WDversion[]="current-cvs.tcpdump.org";
2214 #if !defined(HAVE_GENERATED_VERSION)
2215 	char version[]="current-cvs.tcpdump.org";
2216 #endif
2217 	char pcap_version[]="current-cvs.tcpdump.org";
2218 	char Wpcap_version[]="3.1";
2219 #endif
2220 
2221 /*
2222  * By default, print the specified data out in hex and ASCII.
2223  */
2224 static void
2225 ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
2226 {
2227 	hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */
2228 }
2229 
2230 void
2231 default_print(const u_char *bp, u_int length)
2232 {
2233 	ndo_default_print(gndo, bp, length);
2234 }
2235 
2236 #ifdef SIGNAL_REQ_INFO
2237 RETSIGTYPE requestinfo(int signo _U_)
2238 {
2239 	if (infodelay)
2240 		++infoprint;
2241 	else
2242 		info(0);
2243 }
2244 #endif
2245 
2246 /*
2247  * Called once each second in verbose mode while dumping to file
2248  */
2249 #ifdef USE_WIN32_MM_TIMER
2250 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
2251 				  DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
2252 {
2253 	struct pcap_stat stat;
2254 
2255 	if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2256 		fprintf(stderr, "Got %u\r", packets_captured);
2257 }
2258 #elif defined(HAVE_ALARM)
2259 static void verbose_stats_dump(int sig _U_)
2260 {
2261 	struct pcap_stat stat;
2262 
2263 	if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2264 		fprintf(stderr, "Got %u\r", packets_captured);
2265 	alarm(1);
2266 }
2267 #endif
2268 
2269 static void
2270 usage(void)
2271 {
2272 	extern char version[];
2273 #ifndef HAVE_PCAP_LIB_VERSION
2274 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
2275 	extern char pcap_version[];
2276 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2277 	static char pcap_version[] = "unknown";
2278 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2279 #endif /* HAVE_PCAP_LIB_VERSION */
2280 
2281 #ifdef HAVE_PCAP_LIB_VERSION
2282 #ifdef WIN32
2283 	(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2284 #else /* WIN32 */
2285 	(void)fprintf(stderr, "%s version %s\n", program_name, version);
2286 #endif /* WIN32 */
2287 	(void)fprintf(stderr, "%s\n",pcap_lib_version());
2288 #else /* HAVE_PCAP_LIB_VERSION */
2289 #ifdef WIN32
2290 	(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2291 	(void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
2292 #else /* WIN32 */
2293 	(void)fprintf(stderr, "%s version %s\n", program_name, version);
2294 	(void)fprintf(stderr, "libpcap version %s\n", pcap_version);
2295 #endif /* WIN32 */
2296 #endif /* HAVE_PCAP_LIB_VERSION */
2297 	(void)fprintf(stderr,
2298 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
2299 	(void)fprintf(stderr,
2300 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
2301 	(void)fprintf(stderr,
2302 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ]\n");
2303 	(void)fprintf(stderr,
2304 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -V file ] [ -w file ]\n");
2305 	(void)fprintf(stderr,
2306 "\t\t[ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
2307 	(void)fprintf(stderr,
2308 "\t\t[ -Z user ] [ expression ]\n");
2309 	exit(1);
2310 }
2311 
2312 
2313 
2314 /* VARARGS */
2315 static void
2316 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
2317 {
2318 	va_list ap;
2319 
2320 	(void)fprintf(stderr, "%s: ", program_name);
2321 	va_start(ap, fmt);
2322 	(void)vfprintf(stderr, fmt, ap);
2323 	va_end(ap);
2324 	if (*fmt) {
2325 		fmt += strlen(fmt);
2326 		if (fmt[-1] != '\n')
2327 			(void)fputc('\n', stderr);
2328 	}
2329 	exit(1);
2330 	/* NOTREACHED */
2331 }
2332 
2333 /* VARARGS */
2334 static void
2335 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
2336 {
2337 	va_list ap;
2338 
2339 	(void)fprintf(stderr, "%s: WARNING: ", program_name);
2340 	va_start(ap, fmt);
2341 	(void)vfprintf(stderr, fmt, ap);
2342 	va_end(ap);
2343 	if (*fmt) {
2344 		fmt += strlen(fmt);
2345 		if (fmt[-1] != '\n')
2346 			(void)fputc('\n', stderr);
2347 	}
2348 }
2349