xref: /freebsd/contrib/tcpdump/tcpdump.c (revision 3fc9e2c36555140de248a0b4def91bbfa44d7c2c)
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 #endif	/* __FreeBSD__ */
80 #ifndef WIN32
81 #include <sys/wait.h>
82 #include <sys/resource.h>
83 #include <pwd.h>
84 #include <grp.h>
85 #include <errno.h>
86 #endif /* WIN32 */
87 
88 /* capabilities convinience library */
89 #ifdef HAVE_CAP_NG_H
90 #include <cap-ng.h>
91 #endif /* HAVE_CAP_NG_H */
92 
93 #include "netdissect.h"
94 #include "interface.h"
95 #include "addrtoname.h"
96 #include "machdep.h"
97 #include "setsignal.h"
98 #include "gmt2local.h"
99 #include "pcap-missing.h"
100 
101 #ifndef PATH_MAX
102 #define PATH_MAX 1024
103 #endif
104 
105 #ifdef SIGINFO
106 #define SIGNAL_REQ_INFO SIGINFO
107 #elif SIGUSR1
108 #define SIGNAL_REQ_INFO SIGUSR1
109 #endif
110 
111 netdissect_options Gndo;
112 netdissect_options *gndo = &Gndo;
113 
114 static int dflag;			/* print filter code */
115 static int Lflag;			/* list available data link types and exit */
116 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
117 static int Jflag;			/* list available time stamp types */
118 #endif
119 static char *zflag = NULL;		/* compress each savefile using a specified command (like gzip or bzip2) */
120 
121 static int infodelay;
122 static int infoprint;
123 
124 char *program_name;
125 
126 int32_t thiszone;		/* seconds offset from gmt to local time */
127 
128 /* Forwards */
129 static RETSIGTYPE cleanup(int);
130 static RETSIGTYPE child_cleanup(int);
131 static void usage(void) __attribute__((noreturn));
132 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
133 
134 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
135 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
136 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
137 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
138 static void droproot(const char *, const char *);
139 static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
140      __attribute__ ((noreturn, format (printf, 2, 3)));
141 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
142 
143 #ifdef SIGNAL_REQ_INFO
144 RETSIGTYPE requestinfo(int);
145 #endif
146 
147 #if defined(USE_WIN32_MM_TIMER)
148   #include <MMsystem.h>
149   static UINT timer_id;
150   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
151 #elif defined(HAVE_ALARM)
152   static void verbose_stats_dump(int sig);
153 #endif
154 
155 static void info(int);
156 static u_int packets_captured;
157 
158 struct printer {
159         if_printer f;
160 	int type;
161 };
162 
163 
164 struct ndo_printer {
165         if_ndo_printer f;
166 	int type;
167 };
168 
169 
170 static struct printer printers[] = {
171 	{ arcnet_if_print,	DLT_ARCNET },
172 #ifdef DLT_ARCNET_LINUX
173 	{ arcnet_linux_if_print, DLT_ARCNET_LINUX },
174 #endif
175 	{ token_if_print,	DLT_IEEE802 },
176 #ifdef DLT_LANE8023
177 	{ lane_if_print,        DLT_LANE8023 },
178 #endif
179 #ifdef DLT_CIP
180 	{ cip_if_print,         DLT_CIP },
181 #endif
182 #ifdef DLT_ATM_CLIP
183 	{ cip_if_print,		DLT_ATM_CLIP },
184 #endif
185 	{ sl_if_print,		DLT_SLIP },
186 #ifdef DLT_SLIP_BSDOS
187 	{ sl_bsdos_if_print,	DLT_SLIP_BSDOS },
188 #endif
189 	{ ppp_if_print,		DLT_PPP },
190 #ifdef DLT_PPP_WITHDIRECTION
191 	{ ppp_if_print,		DLT_PPP_WITHDIRECTION },
192 #endif
193 #ifdef DLT_PPP_BSDOS
194 	{ ppp_bsdos_if_print,	DLT_PPP_BSDOS },
195 #endif
196 	{ fddi_if_print,	DLT_FDDI },
197 	{ null_if_print,	DLT_NULL },
198 #ifdef DLT_LOOP
199 	{ null_if_print,	DLT_LOOP },
200 #endif
201 	{ raw_if_print,		DLT_RAW },
202 	{ atm_if_print,		DLT_ATM_RFC1483 },
203 #ifdef DLT_C_HDLC
204 	{ chdlc_if_print,	DLT_C_HDLC },
205 #endif
206 #ifdef DLT_HDLC
207 	{ chdlc_if_print,	DLT_HDLC },
208 #endif
209 #ifdef DLT_PPP_SERIAL
210 	{ ppp_hdlc_if_print,	DLT_PPP_SERIAL },
211 #endif
212 #ifdef DLT_PPP_ETHER
213 	{ pppoe_if_print,	DLT_PPP_ETHER },
214 #endif
215 #ifdef DLT_LINUX_SLL
216 	{ sll_if_print,		DLT_LINUX_SLL },
217 #endif
218 #ifdef DLT_IEEE802_11
219 	{ ieee802_11_if_print,	DLT_IEEE802_11},
220 #endif
221 #ifdef DLT_LTALK
222 	{ ltalk_if_print,	DLT_LTALK },
223 #endif
224 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
225 	{ pflog_if_print,	DLT_PFLOG },
226 #endif
227 #ifdef DLT_FR
228 	{ fr_if_print,		DLT_FR },
229 #endif
230 #ifdef DLT_FRELAY
231 	{ fr_if_print,		DLT_FRELAY },
232 #endif
233 #ifdef DLT_SUNATM
234 	{ sunatm_if_print,	DLT_SUNATM },
235 #endif
236 #ifdef DLT_IP_OVER_FC
237 	{ ipfc_if_print,	DLT_IP_OVER_FC },
238 #endif
239 #ifdef DLT_PRISM_HEADER
240 	{ prism_if_print,	DLT_PRISM_HEADER },
241 #endif
242 #ifdef DLT_IEEE802_11_RADIO
243 	{ ieee802_11_radio_if_print,	DLT_IEEE802_11_RADIO },
244 #endif
245 #ifdef DLT_ENC
246 	{ enc_if_print,		DLT_ENC },
247 #endif
248 #ifdef DLT_SYMANTEC_FIREWALL
249 	{ symantec_if_print,	DLT_SYMANTEC_FIREWALL },
250 #endif
251 #ifdef DLT_APPLE_IP_OVER_IEEE1394
252 	{ ap1394_if_print,	DLT_APPLE_IP_OVER_IEEE1394 },
253 #endif
254 #ifdef DLT_IEEE802_11_RADIO_AVS
255 	{ ieee802_11_radio_avs_if_print,	DLT_IEEE802_11_RADIO_AVS },
256 #endif
257 #ifdef DLT_JUNIPER_ATM1
258 	{ juniper_atm1_print,	DLT_JUNIPER_ATM1 },
259 #endif
260 #ifdef DLT_JUNIPER_ATM2
261 	{ juniper_atm2_print,	DLT_JUNIPER_ATM2 },
262 #endif
263 #ifdef DLT_JUNIPER_MFR
264 	{ juniper_mfr_print,	DLT_JUNIPER_MFR },
265 #endif
266 #ifdef DLT_JUNIPER_MLFR
267 	{ juniper_mlfr_print,	DLT_JUNIPER_MLFR },
268 #endif
269 #ifdef DLT_JUNIPER_MLPPP
270 	{ juniper_mlppp_print,	DLT_JUNIPER_MLPPP },
271 #endif
272 #ifdef DLT_JUNIPER_PPPOE
273 	{ juniper_pppoe_print,	DLT_JUNIPER_PPPOE },
274 #endif
275 #ifdef DLT_JUNIPER_PPPOE_ATM
276 	{ juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
277 #endif
278 #ifdef DLT_JUNIPER_GGSN
279 	{ juniper_ggsn_print,	DLT_JUNIPER_GGSN },
280 #endif
281 #ifdef DLT_JUNIPER_ES
282 	{ juniper_es_print,	DLT_JUNIPER_ES },
283 #endif
284 #ifdef DLT_JUNIPER_MONITOR
285 	{ juniper_monitor_print, DLT_JUNIPER_MONITOR },
286 #endif
287 #ifdef DLT_JUNIPER_SERVICES
288 	{ juniper_services_print, DLT_JUNIPER_SERVICES },
289 #endif
290 #ifdef DLT_JUNIPER_ETHER
291 	{ juniper_ether_print,	DLT_JUNIPER_ETHER },
292 #endif
293 #ifdef DLT_JUNIPER_PPP
294 	{ juniper_ppp_print,	DLT_JUNIPER_PPP },
295 #endif
296 #ifdef DLT_JUNIPER_FRELAY
297 	{ juniper_frelay_print,	DLT_JUNIPER_FRELAY },
298 #endif
299 #ifdef DLT_JUNIPER_CHDLC
300 	{ juniper_chdlc_print,	DLT_JUNIPER_CHDLC },
301 #endif
302 #ifdef DLT_MFR
303 	{ mfr_if_print,		DLT_MFR },
304 #endif
305 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
306 	{ bt_if_print,		DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
307 #endif
308 #ifdef HAVE_PCAP_USB_H
309 #ifdef DLT_USB_LINUX
310 	{ usb_linux_48_byte_print, DLT_USB_LINUX},
311 #endif /* DLT_USB_LINUX */
312 #ifdef DLT_USB_LINUX_MMAPPED
313 	{ usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
314 #endif /* DLT_USB_LINUX_MMAPPED */
315 #endif /* HAVE_PCAP_USB_H */
316 #ifdef DLT_IPV4
317 	{ raw_if_print,		DLT_IPV4 },
318 #endif
319 #ifdef DLT_IPV6
320 	{ raw_if_print,		DLT_IPV6 },
321 #endif
322 	{ NULL,			0 },
323 };
324 
325 static struct ndo_printer ndo_printers[] = {
326 	{ ether_if_print,	DLT_EN10MB },
327 #ifdef DLT_IPNET
328 	{ ipnet_if_print,	DLT_IPNET },
329 #endif
330 #ifdef DLT_IEEE802_15_4
331 	{ ieee802_15_4_if_print, DLT_IEEE802_15_4 },
332 #endif
333 #ifdef DLT_IEEE802_15_4_NOFCS
334 	{ ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
335 #endif
336 #ifdef DLT_PPI
337 	{ ppi_if_print,		DLT_PPI },
338 #endif
339 #ifdef DLT_NETANALYZER
340 	{ netanalyzer_if_print, DLT_NETANALYZER },
341 #endif
342 #ifdef DLT_NETANALYZER_TRANSPARENT
343 	{ netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
344 #endif
345 	{ NULL,			0 },
346 };
347 
348 if_printer
349 lookup_printer(int type)
350 {
351 	struct printer *p;
352 
353 	for (p = printers; p->f; ++p)
354 		if (type == p->type)
355 			return p->f;
356 
357 	return NULL;
358 	/* NOTREACHED */
359 }
360 
361 if_ndo_printer
362 lookup_ndo_printer(int type)
363 {
364 	struct ndo_printer *p;
365 
366 	for (p = ndo_printers; p->f; ++p)
367 		if (type == p->type)
368 			return p->f;
369 
370 	return NULL;
371 	/* NOTREACHED */
372 }
373 
374 static pcap_t *pd;
375 
376 static int supports_monitor_mode;
377 
378 extern int optind;
379 extern int opterr;
380 extern char *optarg;
381 
382 struct print_info {
383         netdissect_options *ndo;
384         union {
385                 if_printer     printer;
386                 if_ndo_printer ndo_printer;
387         } p;
388         int ndo_type;
389 };
390 
391 struct dump_info {
392 	char	*WFileName;
393 	char	*CurrentFileName;
394 	pcap_t	*pd;
395 	pcap_dumper_t *p;
396 #ifdef __FreeBSD__
397 	int	dirfd;
398 #endif
399 };
400 
401 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
402 static void
403 show_tstamp_types_and_exit(const char *device, pcap_t *pd)
404 {
405 	int n_tstamp_types;
406 	int *tstamp_types = 0;
407 	const char *tstamp_type_name;
408 	int i;
409 
410 	n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
411 	if (n_tstamp_types < 0)
412 		error("%s", pcap_geterr(pd));
413 
414 	if (n_tstamp_types == 0) {
415 		fprintf(stderr, "Time stamp type cannot be set for %s\n",
416 		    device);
417 		exit(0);
418 	}
419 	fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
420 	    device);
421 	for (i = 0; i < n_tstamp_types; i++) {
422 		tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
423 		if (tstamp_type_name != NULL) {
424 			(void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
425 			    pcap_tstamp_type_val_to_description(tstamp_types[i]));
426 		} else {
427 			(void) fprintf(stderr, "  %d\n", tstamp_types[i]);
428 		}
429 	}
430 	pcap_free_tstamp_types(tstamp_types);
431 	exit(0);
432 }
433 #endif
434 
435 static void
436 show_dlts_and_exit(const char *device, pcap_t *pd)
437 {
438 	int n_dlts;
439 	int *dlts = 0;
440 	const char *dlt_name;
441 
442 	n_dlts = pcap_list_datalinks(pd, &dlts);
443 	if (n_dlts < 0)
444 		error("%s", pcap_geterr(pd));
445 	else if (n_dlts == 0 || !dlts)
446 		error("No data link types.");
447 
448 	/*
449 	 * If the interface is known to support monitor mode, indicate
450 	 * whether these are the data link types available when not in
451 	 * monitor mode, if -I wasn't specified, or when in monitor mode,
452 	 * when -I was specified (the link-layer types available in
453 	 * monitor mode might be different from the ones available when
454 	 * not in monitor mode).
455 	 */
456 	if (supports_monitor_mode)
457 		(void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
458 		    device,
459 		    Iflag ? "when in monitor mode" : "when not in monitor mode");
460 	else
461 		(void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
462 		    device);
463 
464 	while (--n_dlts >= 0) {
465 		dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
466 		if (dlt_name != NULL) {
467 			(void) fprintf(stderr, "  %s (%s)", dlt_name,
468 			    pcap_datalink_val_to_description(dlts[n_dlts]));
469 
470 			/*
471 			 * OK, does tcpdump handle that type?
472 			 */
473 			if (lookup_printer(dlts[n_dlts]) == NULL
474                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
475 				(void) fprintf(stderr, " (printing not supported)");
476 			fprintf(stderr, "\n");
477 		} else {
478 			(void) fprintf(stderr, "  DLT %d (printing not supported)\n",
479 			    dlts[n_dlts]);
480 		}
481 	}
482 #ifdef HAVE_PCAP_FREE_DATALINKS
483 	pcap_free_datalinks(dlts);
484 #endif
485 	exit(0);
486 }
487 
488 /*
489  * Set up flags that might or might not be supported depending on the
490  * version of libpcap we're using.
491  */
492 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
493 #define B_FLAG		"B:"
494 #define B_FLAG_USAGE	" [ -B size ]"
495 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
496 #define B_FLAG
497 #define B_FLAG_USAGE
498 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
499 
500 #ifdef HAVE_PCAP_CREATE
501 #define I_FLAG		"I"
502 #else /* HAVE_PCAP_CREATE */
503 #define I_FLAG
504 #endif /* HAVE_PCAP_CREATE */
505 
506 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
507 #define j_FLAG		"j:"
508 #define j_FLAG_USAGE	" [ -j tstamptype ]"
509 #define J_FLAG		"J"
510 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
511 #define j_FLAG
512 #define j_FLAG_USAGE
513 #define J_FLAG
514 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
515 
516 #ifdef HAVE_PCAP_FINDALLDEVS
517 #ifndef HAVE_PCAP_IF_T
518 #undef HAVE_PCAP_FINDALLDEVS
519 #endif
520 #endif
521 
522 #ifdef HAVE_PCAP_FINDALLDEVS
523 #define D_FLAG	"D"
524 #else
525 #define D_FLAG
526 #endif
527 
528 #ifdef HAVE_PCAP_DUMP_FLUSH
529 #define U_FLAG	"U"
530 #else
531 #define U_FLAG
532 #endif
533 
534 #ifndef WIN32
535 /* Drop root privileges and chroot if necessary */
536 static void
537 droproot(const char *username, const char *chroot_dir)
538 {
539 	struct passwd *pw = NULL;
540 
541 	if (chroot_dir && !username) {
542 		fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
543 		exit(1);
544 	}
545 
546 	pw = getpwnam(username);
547 	if (pw) {
548 		if (chroot_dir) {
549 			if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
550 				fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
551 				    chroot_dir, pcap_strerror(errno));
552 				exit(1);
553 			}
554 		}
555 #ifdef HAVE_CAP_NG_H
556 		int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
557 		if (ret < 0) {
558 			printf("error : ret %d\n", ret);
559 		}
560 		/* We don't need CAP_SETUID and CAP_SETGID */
561 		capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_SETUID);
562 		capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_SETUID);
563 		capng_update(CAPNG_DROP, CAPNG_PERMITTED, CAP_SETUID);
564 		capng_update(CAPNG_DROP, CAPNG_PERMITTED, CAP_SETUID);
565 		capng_apply(CAPNG_SELECT_BOTH);
566 
567 #else
568 		if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
569 		    setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
570 			fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
571 			    username,
572 			    (unsigned long)pw->pw_uid,
573 			    (unsigned long)pw->pw_gid,
574 			    pcap_strerror(errno));
575 			exit(1);
576 		}
577 #endif /* HAVE_CAP_NG_H */
578 	}
579 	else {
580 		fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
581 		    username);
582 		exit(1);
583 	}
584 }
585 #endif /* WIN32 */
586 
587 static int
588 getWflagChars(int x)
589 {
590 	int c = 0;
591 
592 	x -= 1;
593 	while (x > 0) {
594 		c += 1;
595 		x /= 10;
596 	}
597 
598 	return c;
599 }
600 
601 
602 static void
603 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
604 {
605         char *filename = malloc(PATH_MAX + 1);
606         if (filename == NULL)
607             error("Makefilename: malloc");
608 
609         /* Process with strftime if Gflag is set. */
610         if (Gflag != 0) {
611           struct tm *local_tm;
612 
613           /* Convert Gflag_time to a usable format */
614           if ((local_tm = localtime(&Gflag_time)) == NULL) {
615                   error("MakeTimedFilename: localtime");
616           }
617 
618           /* There's no good way to detect an error in strftime since a return
619            * value of 0 isn't necessarily failure.
620            */
621           strftime(filename, PATH_MAX, orig_name, local_tm);
622         } else {
623           strncpy(filename, orig_name, PATH_MAX);
624         }
625 
626 	if (cnt == 0 && max_chars == 0)
627 		strncpy(buffer, filename, PATH_MAX + 1);
628 	else
629 		if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
630                   /* Report an error if the filename is too large */
631                   error("too many output files or filename is too long (> %d)", PATH_MAX);
632         free(filename);
633 }
634 
635 static int tcpdump_printf(netdissect_options *ndo _U_,
636 			  const char *fmt, ...)
637 {
638 
639   va_list args;
640   int ret;
641 
642   va_start(args, fmt);
643   ret=vfprintf(stdout, fmt, args);
644   va_end(args);
645 
646   return ret;
647 }
648 
649 static struct print_info
650 get_print_info(int type)
651 {
652 	struct print_info printinfo;
653 
654 	printinfo.ndo_type = 1;
655 	printinfo.ndo = gndo;
656 	printinfo.p.ndo_printer = lookup_ndo_printer(type);
657 	if (printinfo.p.ndo_printer == NULL) {
658 		printinfo.p.printer = lookup_printer(type);
659 		printinfo.ndo_type = 0;
660 		if (printinfo.p.printer == NULL) {
661 			gndo->ndo_dltname = pcap_datalink_val_to_name(type);
662 			if (gndo->ndo_dltname != NULL)
663 				error("packet printing is not supported for link type %s: use -w",
664 				      gndo->ndo_dltname);
665 			else
666 				error("packet printing is not supported for link type %d: use -w", type);
667 		}
668 	}
669 	return (printinfo);
670 }
671 
672 static char *
673 get_next_file(FILE *VFile, char *ptr)
674 {
675 	char *ret;
676 
677 	ret = fgets(ptr, PATH_MAX, VFile);
678 	if (!ret)
679 		return NULL;
680 
681 	if (ptr[strlen(ptr) - 1] == '\n')
682 		ptr[strlen(ptr) - 1] = '\0';
683 
684 	return ret;
685 }
686 
687 int
688 main(int argc, char **argv)
689 {
690 	register int cnt, op, i;
691 	bpf_u_int32 localnet, netmask;
692 	register char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
693 	pcap_handler callback;
694 	int type;
695 	int dlt;
696 	int new_dlt;
697 	const char *dlt_name;
698 	struct bpf_program fcode;
699 #ifndef WIN32
700 	RETSIGTYPE (*oldhandler)(int);
701 #endif
702 	struct print_info printinfo;
703 	struct dump_info dumpinfo;
704 	u_char *pcap_userdata;
705 	char ebuf[PCAP_ERRBUF_SIZE];
706 	char VFileLine[PATH_MAX + 1];
707 	char *username = NULL;
708 	char *chroot_dir = NULL;
709 	char *ret = NULL;
710 	char *end;
711 #ifdef HAVE_PCAP_FINDALLDEVS
712 	pcap_if_t *devpointer;
713 	int devnum;
714 #endif
715 	int status;
716 	FILE *VFile;
717 #ifdef __FreeBSD__
718 	cap_rights_t rights;
719 	int cansandbox;
720 #endif	/* __FreeBSD__ */
721 
722 #ifdef WIN32
723 	if(wsockinit() != 0) return 1;
724 #endif /* WIN32 */
725 
726 	jflag=-1;	/* not set */
727         gndo->ndo_Oflag=1;
728 	gndo->ndo_Rflag=1;
729 	gndo->ndo_dlt=-1;
730 	gndo->ndo_default_print=ndo_default_print;
731 	gndo->ndo_printf=tcpdump_printf;
732 	gndo->ndo_error=ndo_error;
733 	gndo->ndo_warning=ndo_warning;
734 	gndo->ndo_snaplen = DEFAULT_SNAPLEN;
735 
736 	cnt = -1;
737 	device = NULL;
738 	infile = NULL;
739 	RFileName = NULL;
740 	VFileName = NULL;
741 	VFile = NULL;
742 	WFileName = NULL;
743 	dlt = -1;
744 	if ((cp = strrchr(argv[0], '/')) != NULL)
745 		program_name = cp + 1;
746 	else
747 		program_name = argv[0];
748 
749 	if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
750 		error("%s", ebuf);
751 
752 #ifdef LIBSMI
753 	smiInit("tcpdump");
754 #endif
755 
756 	while (
757 	    (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)
758 		switch (op) {
759 
760 		case 'a':
761 			/* compatibility for old -a */
762 			break;
763 
764 		case 'A':
765 			++Aflag;
766 			break;
767 
768 		case 'b':
769 			++bflag;
770 			break;
771 
772 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
773 		case 'B':
774 			Bflag = atoi(optarg)*1024;
775 			if (Bflag <= 0)
776 				error("invalid packet buffer size %s", optarg);
777 			break;
778 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
779 
780 		case 'c':
781 			cnt = atoi(optarg);
782 			if (cnt <= 0)
783 				error("invalid packet count %s", optarg);
784 			break;
785 
786 		case 'C':
787 			Cflag = atoi(optarg) * 1000000;
788 			if (Cflag < 0)
789 				error("invalid file size %s", optarg);
790 			break;
791 
792 		case 'd':
793 			++dflag;
794 			break;
795 
796 #ifdef HAVE_PCAP_FINDALLDEVS
797 		case 'D':
798 			if (pcap_findalldevs(&devpointer, ebuf) < 0)
799 				error("%s", ebuf);
800 			else {
801 				for (i = 0; devpointer != 0; i++) {
802 					printf("%d.%s", i+1, devpointer->name);
803 					if (devpointer->description != NULL)
804 						printf(" (%s)", devpointer->description);
805 					printf("\n");
806 					devpointer = devpointer->next;
807 				}
808 			}
809 			return 0;
810 #endif /* HAVE_PCAP_FINDALLDEVS */
811 
812 		case 'L':
813 			Lflag++;
814 			break;
815 
816 		case 'e':
817 			++eflag;
818 			break;
819 
820 		case 'E':
821 #ifndef HAVE_LIBCRYPTO
822 			warning("crypto code not compiled in");
823 #endif
824 			gndo->ndo_espsecret = optarg;
825 			break;
826 
827 		case 'f':
828 			++fflag;
829 			break;
830 
831 		case 'F':
832 			infile = optarg;
833 			break;
834 
835 		case 'G':
836 			Gflag = atoi(optarg);
837 			if (Gflag < 0)
838 				error("invalid number of seconds %s", optarg);
839 
840                         /* We will create one file initially. */
841                         Gflag_count = 0;
842 
843 			/* Grab the current time for rotation use. */
844 			if ((Gflag_time = time(NULL)) == (time_t)-1) {
845 				error("main: can't get current time: %s",
846 				    pcap_strerror(errno));
847 			}
848 			break;
849 
850 		case 'h':
851 			usage();
852 			break;
853 
854 		case 'H':
855 			++Hflag;
856 			break;
857 
858 		case 'i':
859 			if (optarg[0] == '0' && optarg[1] == 0)
860 				error("Invalid adapter index");
861 
862 #ifdef HAVE_PCAP_FINDALLDEVS
863 			/*
864 			 * If the argument is a number, treat it as
865 			 * an index into the list of adapters, as
866 			 * printed by "tcpdump -D".
867 			 *
868 			 * This should be OK on UNIX systems, as interfaces
869 			 * shouldn't have names that begin with digits.
870 			 * It can be useful on Windows, where more than
871 			 * one interface can have the same name.
872 			 */
873 			devnum = strtol(optarg, &end, 10);
874 			if (optarg != end && *end == '\0') {
875 				if (devnum < 0)
876 					error("Invalid adapter index");
877 
878 				if (pcap_findalldevs(&devpointer, ebuf) < 0)
879 					error("%s", ebuf);
880 				else {
881 					/*
882 					 * Look for the devnum-th entry
883 					 * in the list of devices
884 					 * (1-based).
885 					 */
886 					for (i = 0;
887 					    i < devnum-1 && devpointer != NULL;
888 					    i++, devpointer = devpointer->next)
889 						;
890 					if (devpointer == NULL)
891 						error("Invalid adapter index");
892 				}
893 				device = devpointer->name;
894 				break;
895 			}
896 #endif /* HAVE_PCAP_FINDALLDEVS */
897 			device = optarg;
898 			break;
899 
900 #ifdef HAVE_PCAP_CREATE
901 		case 'I':
902 			++Iflag;
903 			break;
904 #endif /* HAVE_PCAP_CREATE */
905 
906 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
907 		case 'j':
908 			jflag = pcap_tstamp_type_name_to_val(optarg);
909 			if (jflag < 0)
910 				error("invalid time stamp type %s", optarg);
911 			break;
912 
913 		case 'J':
914 			Jflag++;
915 			break;
916 #endif
917 
918 		case 'l':
919 #ifdef WIN32
920 			/*
921 			 * _IOLBF is the same as _IOFBF in Microsoft's C
922 			 * libraries; the only alternative they offer
923 			 * is _IONBF.
924 			 *
925 			 * XXX - this should really be checking for MSVC++,
926 			 * not WIN32, if, for example, MinGW has its own
927 			 * C library that is more UNIX-compatible.
928 			 */
929 			setvbuf(stdout, NULL, _IONBF, 0);
930 #else /* WIN32 */
931 #ifdef HAVE_SETLINEBUF
932 			setlinebuf(stdout);
933 #else
934 			setvbuf(stdout, NULL, _IOLBF, 0);
935 #endif
936 #endif /* WIN32 */
937 			break;
938 
939 		case 'K':
940 			++Kflag;
941 			break;
942 
943 		case 'm':
944 #ifdef LIBSMI
945 			if (smiLoadModule(optarg) == 0) {
946 				error("could not load MIB module %s", optarg);
947 			}
948 			sflag = 1;
949 #else
950 			(void)fprintf(stderr, "%s: ignoring option `-m %s' ",
951 				      program_name, optarg);
952 			(void)fprintf(stderr, "(no libsmi support)\n");
953 #endif
954 			break;
955 
956 		case 'M':
957 			/* TCP-MD5 shared secret */
958 #ifndef HAVE_LIBCRYPTO
959 			warning("crypto code not compiled in");
960 #endif
961 			sigsecret = optarg;
962 			break;
963 
964 		case 'n':
965 			++nflag;
966 			break;
967 
968 		case 'N':
969 			++Nflag;
970 			break;
971 
972 		case 'O':
973 			Oflag = 0;
974 			break;
975 
976 		case 'p':
977 			++pflag;
978 			break;
979 
980 		case 'q':
981 			++qflag;
982 			++suppress_default_print;
983 			break;
984 
985 		case 'r':
986 			RFileName = optarg;
987 			break;
988 
989 		case 'R':
990 			Rflag = 0;
991 			break;
992 
993 		case 's':
994 			snaplen = strtol(optarg, &end, 0);
995 			if (optarg == end || *end != '\0'
996 			    || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
997 				error("invalid snaplen %s", optarg);
998 			else if (snaplen == 0)
999 				snaplen = MAXIMUM_SNAPLEN;
1000 			break;
1001 
1002 		case 'S':
1003 			++Sflag;
1004 			break;
1005 
1006 		case 't':
1007 			++tflag;
1008 			break;
1009 
1010 		case 'T':
1011 			if (strcasecmp(optarg, "vat") == 0)
1012 				packettype = PT_VAT;
1013 			else if (strcasecmp(optarg, "wb") == 0)
1014 				packettype = PT_WB;
1015 			else if (strcasecmp(optarg, "rpc") == 0)
1016 				packettype = PT_RPC;
1017 			else if (strcasecmp(optarg, "rtp") == 0)
1018 				packettype = PT_RTP;
1019 			else if (strcasecmp(optarg, "rtcp") == 0)
1020 				packettype = PT_RTCP;
1021 			else if (strcasecmp(optarg, "snmp") == 0)
1022 				packettype = PT_SNMP;
1023 			else if (strcasecmp(optarg, "cnfp") == 0)
1024 				packettype = PT_CNFP;
1025 			else if (strcasecmp(optarg, "tftp") == 0)
1026 				packettype = PT_TFTP;
1027 			else if (strcasecmp(optarg, "aodv") == 0)
1028 				packettype = PT_AODV;
1029 			else if (strcasecmp(optarg, "carp") == 0)
1030 				packettype = PT_CARP;
1031 			else if (strcasecmp(optarg, "radius") == 0)
1032 				packettype = PT_RADIUS;
1033 			else if (strcasecmp(optarg, "zmtp1") == 0)
1034 				packettype = PT_ZMTP1;
1035 			else if (strcasecmp(optarg, "vxlan") == 0)
1036 				packettype = PT_VXLAN;
1037 			else
1038 				error("unknown packet type `%s'", optarg);
1039 			break;
1040 
1041 		case 'u':
1042 			++uflag;
1043 			break;
1044 
1045 #ifdef HAVE_PCAP_DUMP_FLUSH
1046 		case 'U':
1047 			++Uflag;
1048 			break;
1049 #endif
1050 
1051 		case 'v':
1052 			++vflag;
1053 			break;
1054 
1055 		case 'V':
1056 			VFileName = optarg;
1057 			break;
1058 
1059 		case 'w':
1060 			WFileName = optarg;
1061 			break;
1062 
1063 		case 'W':
1064 			Wflag = atoi(optarg);
1065 			if (Wflag < 0)
1066 				error("invalid number of output files %s", optarg);
1067 			WflagChars = getWflagChars(Wflag);
1068 			break;
1069 
1070 		case 'x':
1071 			++xflag;
1072 			++suppress_default_print;
1073 			break;
1074 
1075 		case 'X':
1076 			++Xflag;
1077 			++suppress_default_print;
1078 			break;
1079 
1080 		case 'y':
1081 			gndo->ndo_dltname = optarg;
1082 			gndo->ndo_dlt =
1083 			  pcap_datalink_name_to_val(gndo->ndo_dltname);
1084 			if (gndo->ndo_dlt < 0)
1085 				error("invalid data link type %s", gndo->ndo_dltname);
1086 			break;
1087 
1088 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
1089 		case 'Y':
1090 			{
1091 			/* Undocumented flag */
1092 #ifdef HAVE_PCAP_DEBUG
1093 			extern int pcap_debug;
1094 			pcap_debug = 1;
1095 #else
1096 			extern int yydebug;
1097 			yydebug = 1;
1098 #endif
1099 			}
1100 			break;
1101 #endif
1102 		case 'z':
1103 			if (optarg) {
1104 				zflag = strdup(optarg);
1105 			} else {
1106 				usage();
1107 				/* NOTREACHED */
1108 			}
1109 			break;
1110 
1111 		case 'Z':
1112 			if (optarg) {
1113 				username = strdup(optarg);
1114 			}
1115 			else {
1116 				usage();
1117 				/* NOTREACHED */
1118 			}
1119 			break;
1120 
1121 		default:
1122 			usage();
1123 			/* NOTREACHED */
1124 		}
1125 
1126 	switch (tflag) {
1127 
1128 	case 0: /* Default */
1129 	case 4: /* Default + Date*/
1130 		thiszone = gmt2local(0);
1131 		break;
1132 
1133 	case 1: /* No time stamp */
1134 	case 2: /* Unix timeval style */
1135 	case 3: /* Microseconds since previous packet */
1136         case 5: /* Microseconds since first packet */
1137 		break;
1138 
1139 	default: /* Not supported */
1140 		error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1141 		break;
1142 	}
1143 
1144 	if (fflag != 0 && (VFileName != NULL || RFileName != NULL))
1145 		error("-f can not be used with -V or -r");
1146 
1147 	if (VFileName != NULL && RFileName != NULL)
1148 		error("-V and -r are mutually exclusive.");
1149 
1150 #ifdef WITH_CHROOT
1151 	/* if run as root, prepare for chrooting */
1152 	if (getuid() == 0 || geteuid() == 0) {
1153 		/* future extensibility for cmd-line arguments */
1154 		if (!chroot_dir)
1155 			chroot_dir = WITH_CHROOT;
1156 	}
1157 #endif
1158 
1159 #ifdef WITH_USER
1160 	/* if run as root, prepare for dropping root privileges */
1161 	if (getuid() == 0 || geteuid() == 0) {
1162 		/* Run with '-Z root' to restore old behaviour */
1163 		if (!username)
1164 			username = WITH_USER;
1165 	}
1166 #endif
1167 
1168 	if (RFileName != NULL || VFileName != NULL) {
1169 		/*
1170 		 * If RFileName is non-null, it's the pathname of a
1171 		 * savefile to read.  If VFileName is non-null, it's
1172 		 * the pathname of a file containing a list of pathnames
1173 		 * (one per line) of savefiles to read.
1174 		 *
1175 		 * In either case, we're reading a savefile, not doing
1176 		 * a live capture.
1177 		 */
1178 #ifndef WIN32
1179 		/*
1180 		 * We don't need network access, so relinquish any set-UID
1181 		 * or set-GID privileges we have (if any).
1182 		 *
1183 		 * We do *not* want set-UID privileges when opening a
1184 		 * trace file, as that might let the user read other
1185 		 * people's trace files (especially if we're set-UID
1186 		 * root).
1187 		 */
1188 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1189 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
1190 #endif /* WIN32 */
1191 		if (VFileName != NULL) {
1192 			if (VFileName[0] == '-' && VFileName[1] == '\0')
1193 				VFile = stdin;
1194 			else
1195 				VFile = fopen(VFileName, "r");
1196 
1197 			if (VFile == NULL)
1198 				error("Unable to open file: %s\n", strerror(errno));
1199 
1200 			ret = get_next_file(VFile, VFileLine);
1201 			if (!ret)
1202 				error("Nothing in %s\n", VFileName);
1203 			RFileName = VFileLine;
1204 		}
1205 
1206 		pd = pcap_open_offline(RFileName, ebuf);
1207 		if (pd == NULL)
1208 			error("%s", ebuf);
1209 #ifdef __FreeBSD__
1210 		cap_rights_init(&rights, CAP_READ);
1211 		if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
1212 		    errno != ENOSYS) {
1213 			error("unable to limit pcap descriptor");
1214 		}
1215 #endif
1216 		dlt = pcap_datalink(pd);
1217 		dlt_name = pcap_datalink_val_to_name(dlt);
1218 		if (dlt_name == NULL) {
1219 			fprintf(stderr, "reading from file %s, link-type %u\n",
1220 			    RFileName, dlt);
1221 		} else {
1222 			fprintf(stderr,
1223 			    "reading from file %s, link-type %s (%s)\n",
1224 			    RFileName, dlt_name,
1225 			    pcap_datalink_val_to_description(dlt));
1226 		}
1227 		localnet = 0;
1228 		netmask = 0;
1229 	} else {
1230 		/*
1231 		 * We're doing a live capture.
1232 		 */
1233 		if (device == NULL) {
1234 			device = pcap_lookupdev(ebuf);
1235 			if (device == NULL)
1236 				error("%s", ebuf);
1237 		}
1238 #ifdef WIN32
1239 		/*
1240 		 * Print a message to the standard error on Windows.
1241 		 * XXX - why do it here, with a different message?
1242 		 */
1243 		if(strlen(device) == 1)	//we assume that an ASCII string is always longer than 1 char
1244 		{						//a Unicode string has a \0 as second byte (so strlen() is 1)
1245 			fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1246 		}
1247 		else
1248 		{
1249 			fprintf(stderr, "%s: listening on %s\n", program_name, device);
1250 		}
1251 
1252 		fflush(stderr);
1253 #endif /* WIN32 */
1254 #ifdef HAVE_PCAP_CREATE
1255 		pd = pcap_create(device, ebuf);
1256 		if (pd == NULL)
1257 			error("%s", ebuf);
1258 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1259 		if (Jflag)
1260 			show_tstamp_types_and_exit(device, pd);
1261 #endif
1262 		/*
1263 		 * Is this an interface that supports monitor mode?
1264 		 */
1265 		if (pcap_can_set_rfmon(pd) == 1)
1266 			supports_monitor_mode = 1;
1267 		else
1268 			supports_monitor_mode = 0;
1269 		status = pcap_set_snaplen(pd, snaplen);
1270 		if (status != 0)
1271 			error("%s: Can't set snapshot length: %s",
1272 			    device, pcap_statustostr(status));
1273 		status = pcap_set_promisc(pd, !pflag);
1274 		if (status != 0)
1275 			error("%s: Can't set promiscuous mode: %s",
1276 			    device, pcap_statustostr(status));
1277 		if (Iflag) {
1278 			status = pcap_set_rfmon(pd, 1);
1279 			if (status != 0)
1280 				error("%s: Can't set monitor mode: %s",
1281 				    device, pcap_statustostr(status));
1282 		}
1283 		status = pcap_set_timeout(pd, 1000);
1284 		if (status != 0)
1285 			error("%s: pcap_set_timeout failed: %s",
1286 			    device, pcap_statustostr(status));
1287 		if (Bflag != 0) {
1288 			status = pcap_set_buffer_size(pd, Bflag);
1289 			if (status != 0)
1290 				error("%s: Can't set buffer size: %s",
1291 				    device, pcap_statustostr(status));
1292 		}
1293 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1294                 if (jflag != -1) {
1295 			status = pcap_set_tstamp_type(pd, jflag);
1296 			if (status < 0)
1297 				error("%s: Can't set time stamp type: %s",
1298 			    	    device, pcap_statustostr(status));
1299 		}
1300 #endif
1301 		status = pcap_activate(pd);
1302 		if (status < 0) {
1303 			/*
1304 			 * pcap_activate() failed.
1305 			 */
1306 			cp = pcap_geterr(pd);
1307 			if (status == PCAP_ERROR)
1308 				error("%s", cp);
1309 			else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1310 			          status == PCAP_ERROR_PERM_DENIED) &&
1311 			         *cp != '\0')
1312 				error("%s: %s\n(%s)", device,
1313 				    pcap_statustostr(status), cp);
1314 #ifdef __FreeBSD__
1315 			else if (status == PCAP_ERROR_RFMON_NOTSUP &&
1316 			    strncmp(device, "wlan", 4) == 0) {
1317 				char parent[8], newdev[8];
1318 				char sysctl[32];
1319 				size_t s = sizeof(parent);
1320 
1321 				snprintf(sysctl, sizeof(sysctl),
1322 				    "net.wlan.%d.%%parent", atoi(device + 4));
1323 				sysctlbyname(sysctl, parent, &s, NULL, 0);
1324 				strlcpy(newdev, device, sizeof(newdev));
1325 				/* Suggest a new wlan device. */
1326 				newdev[strlen(newdev)-1]++;
1327 				error("%s is not a monitor mode VAP\n"
1328 				    "To create a new monitor mode VAP use:\n"
1329 				    "  ifconfig %s create wlandev %s wlanmode "
1330 				    "monitor\nand use %s as the tcpdump "
1331 				    "interface", device, newdev, parent,
1332 				    newdev);
1333 			}
1334 #endif
1335 			else
1336 				error("%s: %s", device,
1337 				    pcap_statustostr(status));
1338 		} else if (status > 0) {
1339 			/*
1340 			 * pcap_activate() succeeded, but it's warning us
1341 			 * of a problem it had.
1342 			 */
1343 			cp = pcap_geterr(pd);
1344 			if (status == PCAP_WARNING)
1345 				warning("%s", cp);
1346 			else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1347 			         *cp != '\0')
1348 				warning("%s: %s\n(%s)", device,
1349 				    pcap_statustostr(status), cp);
1350 			else
1351 				warning("%s: %s", device,
1352 				    pcap_statustostr(status));
1353 		}
1354 #else
1355 		*ebuf = '\0';
1356 		pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1357 		if (pd == NULL)
1358 			error("%s", ebuf);
1359 		else if (*ebuf)
1360 			warning("%s", ebuf);
1361 #endif /* HAVE_PCAP_CREATE */
1362 		/*
1363 		 * Let user own process after socket has been opened.
1364 		 */
1365 #ifndef WIN32
1366 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1367 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
1368 #endif /* WIN32 */
1369 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1370 		if(Bflag != 0)
1371 			if(pcap_setbuff(pd, Bflag)==-1){
1372 				error("%s", pcap_geterr(pd));
1373 			}
1374 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1375 		if (Lflag)
1376 			show_dlts_and_exit(device, pd);
1377 		if (gndo->ndo_dlt >= 0) {
1378 #ifdef HAVE_PCAP_SET_DATALINK
1379 			if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1380 				error("%s", pcap_geterr(pd));
1381 #else
1382 			/*
1383 			 * We don't actually support changing the
1384 			 * data link type, so we only let them
1385 			 * set it to what it already is.
1386 			 */
1387 			if (gndo->ndo_dlt != pcap_datalink(pd)) {
1388 				error("%s is not one of the DLTs supported by this device\n",
1389 				      gndo->ndo_dltname);
1390 			}
1391 #endif
1392 			(void)fprintf(stderr, "%s: data link type %s\n",
1393 				      program_name, gndo->ndo_dltname);
1394 			(void)fflush(stderr);
1395 		}
1396 		i = pcap_snapshot(pd);
1397 		if (snaplen < i) {
1398 			warning("snaplen raised from %d to %d", snaplen, i);
1399 			snaplen = i;
1400 		}
1401 		if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1402 			localnet = 0;
1403 			netmask = 0;
1404 			warning("%s", ebuf);
1405 		}
1406 	}
1407 	if (infile)
1408 		cmdbuf = read_infile(infile);
1409 	else
1410 		cmdbuf = copy_argv(&argv[optind]);
1411 
1412 	if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1413 		error("%s", pcap_geterr(pd));
1414 	if (dflag) {
1415 		bpf_dump(&fcode, dflag);
1416 		pcap_close(pd);
1417 		free(cmdbuf);
1418 		exit(0);
1419 	}
1420 	init_addrtoname(localnet, netmask);
1421         init_checksum();
1422 
1423 #ifndef WIN32
1424 	(void)setsignal(SIGPIPE, cleanup);
1425 	(void)setsignal(SIGTERM, cleanup);
1426 	(void)setsignal(SIGINT, cleanup);
1427 #endif /* WIN32 */
1428 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1429 	(void)setsignal(SIGCHLD, child_cleanup);
1430 #endif
1431 	/* Cooperate with nohup(1) */
1432 #ifndef WIN32
1433 	if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1434 		(void)setsignal(SIGHUP, oldhandler);
1435 #endif /* WIN32 */
1436 
1437 #ifndef WIN32
1438 	/*
1439 	 * If a user name was specified with "-Z", attempt to switch to
1440 	 * that user's UID.  This would probably be used with sudo,
1441 	 * to allow tcpdump to be run in a special restricted
1442 	 * account (if you just want to allow users to open capture
1443 	 * devices, and can't just give users that permission,
1444 	 * you'd make tcpdump set-UID or set-GID).
1445 	 *
1446 	 * Tcpdump doesn't necessarily write only to one savefile;
1447 	 * the general only way to allow a -Z instance to write to
1448 	 * savefiles as the user under whose UID it's run, rather
1449 	 * than as the user specified with -Z, would thus be to switch
1450 	 * to the original user ID before opening a capture file and
1451 	 * then switch back to the -Z user ID after opening the savefile.
1452 	 * Switching to the -Z user ID only after opening the first
1453 	 * savefile doesn't handle the general case.
1454 	 */
1455 
1456 #ifdef HAVE_CAP_NG_H
1457 	/* We are running as root and we will be writing to savefile */
1458 	if ((getuid() == 0 || geteuid() == 0) && WFileName) {
1459 		if (username) {
1460 			/* Drop all capabilities from effective set */
1461 			capng_clear(CAPNG_EFFECTIVE);
1462 			/* Add capabilities we will need*/
1463 			capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_SETUID);
1464 			capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_SETGID);
1465 			capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_DAC_OVERRIDE);
1466 
1467 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_SETUID);
1468 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_SETGID);
1469 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
1470 
1471 			capng_apply(CAPNG_SELECT_BOTH);
1472 		}
1473 	}
1474 #endif /* HAVE_CAP_NG_H */
1475 
1476 	if (getuid() == 0 || geteuid() == 0) {
1477 		if (username || chroot_dir)
1478 			droproot(username, chroot_dir);
1479 
1480 	}
1481 #endif /* WIN32 */
1482 
1483 	if (pcap_setfilter(pd, &fcode) < 0)
1484 		error("%s", pcap_geterr(pd));
1485 #ifdef __FreeBSD__
1486 	if (RFileName == NULL && VFileName == NULL) {
1487 		static const unsigned long cmds[] = { BIOCGSTATS };
1488 
1489 		cap_rights_init(&rights, CAP_IOCTL, CAP_READ);
1490 		if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
1491 		    errno != ENOSYS) {
1492 			error("unable to limit pcap descriptor");
1493 		}
1494 		if (cap_ioctls_limit(pcap_fileno(pd), cmds,
1495 		    sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
1496 			error("unable to limit ioctls on pcap descriptor");
1497 		}
1498 	}
1499 #endif
1500 	if (WFileName) {
1501 		pcap_dumper_t *p;
1502 		/* Do not exceed the default PATH_MAX for files. */
1503 		dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
1504 
1505 		if (dumpinfo.CurrentFileName == NULL)
1506 			error("malloc of dumpinfo.CurrentFileName");
1507 
1508 		/* We do not need numbering for dumpfiles if Cflag isn't set. */
1509 		if (Cflag != 0)
1510 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1511 		else
1512 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1513 
1514 		p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1515 #ifdef HAVE_CAP_NG_H
1516         /* Give up capabilities, clear Effective set */
1517         capng_clear(CAPNG_EFFECTIVE);
1518 #endif
1519 		if (p == NULL)
1520 			error("%s", pcap_geterr(pd));
1521 #ifdef __FreeBSD__
1522 		cap_rights_init(&rights, CAP_SEEK, CAP_WRITE);
1523 		if (cap_rights_limit(fileno(pcap_dump_file(p)), &rights) < 0 &&
1524 		    errno != ENOSYS) {
1525 			error("unable to limit dump descriptor");
1526 		}
1527 #endif
1528 		if (Cflag != 0 || Gflag != 0) {
1529 #ifdef __FreeBSD__
1530 			dumpinfo.WFileName = strdup(basename(WFileName));
1531 			dumpinfo.dirfd = open(dirname(WFileName),
1532 			    O_DIRECTORY | O_RDONLY);
1533 			if (dumpinfo.dirfd < 0) {
1534 				error("unable to open directory %s",
1535 				    dirname(WFileName));
1536 			}
1537 			cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
1538 			    CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
1539 			if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
1540 			    errno != ENOSYS) {
1541 				error("unable to limit directory rights");
1542 			}
1543 #else	/* !__FreeBSD__ */
1544 			dumpinfo.WFileName = WFileName;
1545 #endif
1546 			callback = dump_packet_and_trunc;
1547 			dumpinfo.pd = pd;
1548 			dumpinfo.p = p;
1549 			pcap_userdata = (u_char *)&dumpinfo;
1550 		} else {
1551 			callback = dump_packet;
1552 			pcap_userdata = (u_char *)p;
1553 		}
1554 #ifdef HAVE_PCAP_DUMP_FLUSH
1555 		if (Uflag)
1556 			pcap_dump_flush(p);
1557 #endif
1558 	} else {
1559 		type = pcap_datalink(pd);
1560 		printinfo = get_print_info(type);
1561 		callback = print_packet;
1562 		pcap_userdata = (u_char *)&printinfo;
1563 	}
1564 
1565 #ifdef SIGNAL_REQ_INFO
1566 	/*
1567 	 * We can't get statistics when reading from a file rather
1568 	 * than capturing from a device.
1569 	 */
1570 	if (RFileName == NULL)
1571 		(void)setsignal(SIGNAL_REQ_INFO, requestinfo);
1572 #endif
1573 
1574 	if (vflag > 0 && WFileName) {
1575 		/*
1576 		 * When capturing to a file, "-v" means tcpdump should,
1577 		 * every 10 secodns, "v"erbosely report the number of
1578 		 * packets captured.
1579 		 */
1580 #ifdef USE_WIN32_MM_TIMER
1581 		/* call verbose_stats_dump() each 1000 +/-100msec */
1582 		timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1583 		setvbuf(stderr, NULL, _IONBF, 0);
1584 #elif defined(HAVE_ALARM)
1585 		(void)setsignal(SIGALRM, verbose_stats_dump);
1586 		alarm(1);
1587 #endif
1588 	}
1589 
1590 #ifndef WIN32
1591 	if (RFileName == NULL) {
1592 		/*
1593 		 * Live capture (if -V was specified, we set RFileName
1594 		 * to a file from the -V file).  Print a message to
1595 		 * the standard error on UN*X.
1596 		 */
1597 		if (!vflag && !WFileName) {
1598 			(void)fprintf(stderr,
1599 			    "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1600 			    program_name);
1601 		} else
1602 			(void)fprintf(stderr, "%s: ", program_name);
1603 		dlt = pcap_datalink(pd);
1604 		dlt_name = pcap_datalink_val_to_name(dlt);
1605 		if (dlt_name == NULL) {
1606 			(void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1607 			    device, dlt, snaplen);
1608 		} else {
1609 			(void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1610 			    device, dlt_name,
1611 			    pcap_datalink_val_to_description(dlt), snaplen);
1612 		}
1613 		(void)fflush(stderr);
1614 	}
1615 #endif /* WIN32 */
1616 
1617 #ifdef __FreeBSD__
1618 	cansandbox = (nflag && VFileName == NULL && zflag == NULL);
1619 	if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
1620 		error("unable to enter the capability mode");
1621 	if (cap_sandboxed())
1622 		fprintf(stderr, "capability mode sandbox enabled\n");
1623 #endif	/* __FreeBSD__ */
1624 
1625 	do {
1626 		status = pcap_loop(pd, cnt, callback, pcap_userdata);
1627 		if (WFileName == NULL) {
1628 			/*
1629 			 * We're printing packets.  Flush the printed output,
1630 			 * so it doesn't get intermingled with error output.
1631 			 */
1632 			if (status == -2) {
1633 				/*
1634 				 * We got interrupted, so perhaps we didn't
1635 				 * manage to finish a line we were printing.
1636 				 * Print an extra newline, just in case.
1637 				 */
1638 				putchar('\n');
1639 			}
1640 			(void)fflush(stdout);
1641 		}
1642 		if (status == -1) {
1643 			/*
1644 			 * Error.  Report it.
1645 			 */
1646 			(void)fprintf(stderr, "%s: pcap_loop: %s\n",
1647 			    program_name, pcap_geterr(pd));
1648 		}
1649 		if (RFileName == NULL) {
1650 			/*
1651 			 * We're doing a live capture.  Report the capture
1652 			 * statistics.
1653 			 */
1654 			info(1);
1655 		}
1656 		pcap_close(pd);
1657 		if (VFileName != NULL) {
1658 			ret = get_next_file(VFile, VFileLine);
1659 			if (ret) {
1660 				RFileName = VFileLine;
1661 				pd = pcap_open_offline(RFileName, ebuf);
1662 				if (pd == NULL)
1663 					error("%s", ebuf);
1664 #ifdef __FreeBSD__
1665 				cap_rights_init(&rights, CAP_READ);
1666 				if (cap_rights_limit(fileno(pcap_file(pd)),
1667 				    &rights) < 0 && errno != ENOSYS) {
1668 					error("unable to limit pcap descriptor");
1669 				}
1670 #endif
1671 				new_dlt = pcap_datalink(pd);
1672 				if (WFileName && new_dlt != dlt)
1673 					error("%s: new dlt does not match original", RFileName);
1674 				printinfo = get_print_info(new_dlt);
1675 				dlt_name = pcap_datalink_val_to_name(new_dlt);
1676 				if (dlt_name == NULL) {
1677 					fprintf(stderr, "reading from file %s, link-type %u\n",
1678 					RFileName, new_dlt);
1679 				} else {
1680 					fprintf(stderr,
1681 					"reading from file %s, link-type %s (%s)\n",
1682 					RFileName, dlt_name,
1683 					pcap_datalink_val_to_description(new_dlt));
1684 				}
1685 				if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1686 					error("%s", pcap_geterr(pd));
1687 				if (pcap_setfilter(pd, &fcode) < 0)
1688 					error("%s", pcap_geterr(pd));
1689 			}
1690 		}
1691 	}
1692 	while (ret != NULL);
1693 
1694 	free(cmdbuf);
1695 	exit(status == -1 ? 1 : 0);
1696 }
1697 
1698 /* make a clean exit on interrupts */
1699 static RETSIGTYPE
1700 cleanup(int signo _U_)
1701 {
1702 #ifdef USE_WIN32_MM_TIMER
1703 	if (timer_id)
1704 		timeKillEvent(timer_id);
1705 	timer_id = 0;
1706 #elif defined(HAVE_ALARM)
1707 	alarm(0);
1708 #endif
1709 
1710 #ifdef HAVE_PCAP_BREAKLOOP
1711 	/*
1712 	 * We have "pcap_breakloop()"; use it, so that we do as little
1713 	 * as possible in the signal handler (it's probably not safe
1714 	 * to do anything with standard I/O streams in a signal handler -
1715 	 * the ANSI C standard doesn't say it is).
1716 	 */
1717 	pcap_breakloop(pd);
1718 #else
1719 	/*
1720 	 * We don't have "pcap_breakloop()"; this isn't safe, but
1721 	 * it's the best we can do.  Print the summary if we're
1722 	 * not reading from a savefile - i.e., if we're doing a
1723 	 * live capture - and exit.
1724 	 */
1725 	if (pd != NULL && pcap_file(pd) == NULL) {
1726 		/*
1727 		 * We got interrupted, so perhaps we didn't
1728 		 * manage to finish a line we were printing.
1729 		 * Print an extra newline, just in case.
1730 		 */
1731 		putchar('\n');
1732 		(void)fflush(stdout);
1733 		info(1);
1734 	}
1735 	exit(0);
1736 #endif
1737 }
1738 
1739 /*
1740   On windows, we do not use a fork, so we do not care less about
1741   waiting a child processes to die
1742  */
1743 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1744 static RETSIGTYPE
1745 child_cleanup(int signo _U_)
1746 {
1747   wait(NULL);
1748 }
1749 #endif /* HAVE_FORK && HAVE_VFORK */
1750 
1751 static void
1752 info(register int verbose)
1753 {
1754 	struct pcap_stat stat;
1755 
1756 	/*
1757 	 * Older versions of libpcap didn't set ps_ifdrop on some
1758 	 * platforms; initialize it to 0 to handle that.
1759 	 */
1760 	stat.ps_ifdrop = 0;
1761 	if (pcap_stats(pd, &stat) < 0) {
1762 		(void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1763 		infoprint = 0;
1764 		return;
1765 	}
1766 
1767 	if (!verbose)
1768 		fprintf(stderr, "%s: ", program_name);
1769 
1770 	(void)fprintf(stderr, "%u packet%s captured", packets_captured,
1771 	    PLURAL_SUFFIX(packets_captured));
1772 	if (!verbose)
1773 		fputs(", ", stderr);
1774 	else
1775 		putc('\n', stderr);
1776 	(void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
1777 	    PLURAL_SUFFIX(stat.ps_recv));
1778 	if (!verbose)
1779 		fputs(", ", stderr);
1780 	else
1781 		putc('\n', stderr);
1782 	(void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
1783 	    PLURAL_SUFFIX(stat.ps_drop));
1784 	if (stat.ps_ifdrop != 0) {
1785 		if (!verbose)
1786 			fputs(", ", stderr);
1787 		else
1788 			putc('\n', stderr);
1789 		(void)fprintf(stderr, "%u packet%s dropped by interface\n",
1790 		    stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
1791 	} else
1792 		putc('\n', stderr);
1793 	infoprint = 0;
1794 }
1795 
1796 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1797 static void
1798 compress_savefile(const char *filename)
1799 {
1800 # ifdef HAVE_FORK
1801 	if (fork())
1802 # else
1803 	if (vfork())
1804 # endif
1805 		return;
1806 	/*
1807 	 * Set to lowest priority so that this doesn't disturb the capture
1808 	 */
1809 #ifdef NZERO
1810 	setpriority(PRIO_PROCESS, 0, NZERO - 1);
1811 #else
1812 	setpriority(PRIO_PROCESS, 0, 19);
1813 #endif
1814 	if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
1815 		fprintf(stderr,
1816 			"compress_savefile:execlp(%s, %s): %s\n",
1817 			zflag,
1818 			filename,
1819 			strerror(errno));
1820 # ifdef HAVE_FORK
1821 	exit(1);
1822 # else
1823 	_exit(1);
1824 # endif
1825 }
1826 #else  /* HAVE_FORK && HAVE_VFORK */
1827 static void
1828 compress_savefile(const char *filename)
1829 {
1830 	fprintf(stderr,
1831 		"compress_savefile failed. Functionality not implemented under your system\n");
1832 }
1833 #endif /* HAVE_FORK && HAVE_VFORK */
1834 
1835 static void
1836 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1837 {
1838 	struct dump_info *dump_info;
1839 #ifdef __FreeBSD__
1840 	cap_rights_t rights;
1841 #endif
1842 
1843 	++packets_captured;
1844 
1845 	++infodelay;
1846 
1847 	dump_info = (struct dump_info *)user;
1848 
1849 	/*
1850 	 * XXX - this won't force the file to rotate on the specified time
1851 	 * boundary, but it will rotate on the first packet received after the
1852 	 * specified Gflag number of seconds. Note: if a Gflag time boundary
1853 	 * and a Cflag size boundary coincide, the time rotation will occur
1854 	 * first thereby cancelling the Cflag boundary (since the file should
1855 	 * be 0).
1856 	 */
1857 	if (Gflag != 0) {
1858 		/* Check if it is time to rotate */
1859 		time_t t;
1860 
1861 		/* Get the current time */
1862 		if ((t = time(NULL)) == (time_t)-1) {
1863 			error("dump_and_trunc_packet: can't get current_time: %s",
1864 			    pcap_strerror(errno));
1865 		}
1866 
1867 
1868 		/* If the time is greater than the specified window, rotate */
1869 		if (t - Gflag_time >= Gflag) {
1870 #ifdef __FreeBSD__
1871 			FILE *fp;
1872 			int fd;
1873 #endif
1874 
1875 			/* Update the Gflag_time */
1876 			Gflag_time = t;
1877 			/* Update Gflag_count */
1878 			Gflag_count++;
1879 			/*
1880 			 * Close the current file and open a new one.
1881 			 */
1882 			pcap_dump_close(dump_info->p);
1883 
1884 			/*
1885 			 * Compress the file we just closed, if the user asked for it
1886 			 */
1887 			if (zflag != NULL)
1888 				compress_savefile(dump_info->CurrentFileName);
1889 
1890 			/*
1891 			 * Check to see if we've exceeded the Wflag (when
1892 			 * not using Cflag).
1893 			 */
1894 			if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
1895 				(void)fprintf(stderr, "Maximum file limit reached: %d\n",
1896 				    Wflag);
1897 				exit(0);
1898 				/* NOTREACHED */
1899 			}
1900 			if (dump_info->CurrentFileName != NULL)
1901 				free(dump_info->CurrentFileName);
1902 			/* Allocate space for max filename + \0. */
1903 			dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
1904 			if (dump_info->CurrentFileName == NULL)
1905 				error("dump_packet_and_trunc: malloc");
1906 			/*
1907 			 * This is always the first file in the Cflag
1908 			 * rotation: e.g. 0
1909 			 * We also don't need numbering if Cflag is not set.
1910 			 */
1911 			if (Cflag != 0)
1912 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
1913 				    WflagChars);
1914 			else
1915 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
1916 
1917 #ifdef HAVE_CAP_NG_H
1918 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
1919 			capng_apply(CAPNG_EFFECTIVE);
1920 #endif /* HAVE_CAP_NG_H */
1921 #ifdef __FreeBSD__
1922 			fd = openat(dump_info->dirfd,
1923 			    dump_info->CurrentFileName,
1924 			    O_CREAT | O_WRONLY | O_TRUNC, 0644);
1925 			if (fd < 0) {
1926 				error("unable to open file %s",
1927 				    dump_info->CurrentFileName);
1928 			}
1929 			fp = fdopen(fd, "w");
1930 			if (fp == NULL) {
1931 				error("unable to fdopen file %s",
1932 				    dump_info->CurrentFileName);
1933 			}
1934 			dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
1935 #else	/* !__FreeBSD__ */
1936 			dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1937 #endif
1938 #ifdef HAVE_CAP_NG_H
1939 			capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
1940 			capng_apply(CAPNG_EFFECTIVE);
1941 #endif /* HAVE_CAP_NG_H */
1942 			if (dump_info->p == NULL)
1943 				error("%s", pcap_geterr(pd));
1944 #ifdef __FreeBSD__
1945 			cap_rights_init(&rights, CAP_SEEK, CAP_WRITE);
1946 			if (cap_rights_limit(fileno(pcap_dump_file(dump_info->p)),
1947 			    &rights) < 0 && errno != ENOSYS) {
1948 				error("unable to limit dump descriptor");
1949 			}
1950 #endif
1951 		}
1952 	}
1953 
1954 	/*
1955 	 * XXX - this won't prevent capture files from getting
1956 	 * larger than Cflag - the last packet written to the
1957 	 * file could put it over Cflag.
1958 	 */
1959 	if (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) {
1960 #ifdef __FreeBSD__
1961 		FILE *fp;
1962 		int fd;
1963 #endif
1964 
1965 		/*
1966 		 * Close the current file and open a new one.
1967 		 */
1968 		pcap_dump_close(dump_info->p);
1969 
1970 		/*
1971 		 * Compress the file we just closed, if the user asked for it
1972 		 */
1973 		if (zflag != NULL)
1974 			compress_savefile(dump_info->CurrentFileName);
1975 
1976 		Cflag_count++;
1977 		if (Wflag > 0) {
1978 			if (Cflag_count >= Wflag)
1979 				Cflag_count = 0;
1980 		}
1981 		if (dump_info->CurrentFileName != NULL)
1982 			free(dump_info->CurrentFileName);
1983 		dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
1984 		if (dump_info->CurrentFileName == NULL)
1985 			error("dump_packet_and_trunc: malloc");
1986 		MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
1987 #ifdef __FreeBSD__
1988 		fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
1989 		    O_CREAT | O_WRONLY | O_TRUNC, 0644);
1990 		if (fd < 0) {
1991 			error("unable to open file %s",
1992 			    dump_info->CurrentFileName);
1993 		}
1994 		fp = fdopen(fd, "w");
1995 		if (fp == NULL) {
1996 			error("unable to fdopen file %s",
1997 			    dump_info->CurrentFileName);
1998 		}
1999 		dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2000 #else	/* !__FreeBSD__ */
2001 		dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2002 #endif
2003 		if (dump_info->p == NULL)
2004 			error("%s", pcap_geterr(pd));
2005 #ifdef __FreeBSD__
2006 		cap_rights_init(&rights, CAP_SEEK, CAP_WRITE);
2007 		if (cap_rights_limit(fileno(pcap_dump_file(dump_info->p)),
2008 		    &rights) < 0 && errno != ENOSYS) {
2009 			error("unable to limit dump descriptor");
2010 		}
2011 #endif
2012 	}
2013 
2014 	pcap_dump((u_char *)dump_info->p, h, sp);
2015 #ifdef HAVE_PCAP_DUMP_FLUSH
2016 	if (Uflag)
2017 		pcap_dump_flush(dump_info->p);
2018 #endif
2019 
2020 	--infodelay;
2021 	if (infoprint)
2022 		info(0);
2023 }
2024 
2025 static void
2026 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2027 {
2028 	++packets_captured;
2029 
2030 	++infodelay;
2031 
2032 	pcap_dump(user, h, sp);
2033 #ifdef HAVE_PCAP_DUMP_FLUSH
2034 	if (Uflag)
2035 		pcap_dump_flush((pcap_dumper_t *)user);
2036 #endif
2037 
2038 	--infodelay;
2039 	if (infoprint)
2040 		info(0);
2041 }
2042 
2043 static void
2044 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2045 {
2046 	struct print_info *print_info;
2047 	u_int hdrlen;
2048 
2049 	++packets_captured;
2050 
2051 	++infodelay;
2052 	ts_print(&h->ts);
2053 
2054 	print_info = (struct print_info *)user;
2055 
2056 	/*
2057 	 * Some printers want to check that they're not walking off the
2058 	 * end of the packet.
2059 	 * Rather than pass it all the way down, we set this global.
2060 	 */
2061 	snapend = sp + h->caplen;
2062 
2063         if(print_info->ndo_type) {
2064                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
2065         } else {
2066                 hdrlen = (*print_info->p.printer)(h, sp);
2067         }
2068 
2069 	if (Xflag) {
2070 		/*
2071 		 * Print the raw packet data in hex and ASCII.
2072 		 */
2073 		if (Xflag > 1) {
2074 			/*
2075 			 * Include the link-layer header.
2076 			 */
2077 			hex_and_ascii_print("\n\t", sp, h->caplen);
2078 		} else {
2079 			/*
2080 			 * Don't include the link-layer header - and if
2081 			 * we have nothing past the link-layer header,
2082 			 * print nothing.
2083 			 */
2084 			if (h->caplen > hdrlen)
2085 				hex_and_ascii_print("\n\t", sp + hdrlen,
2086 				    h->caplen - hdrlen);
2087 		}
2088 	} else if (xflag) {
2089 		/*
2090 		 * Print the raw packet data in hex.
2091 		 */
2092 		if (xflag > 1) {
2093 			/*
2094 			 * Include the link-layer header.
2095 			 */
2096 			hex_print("\n\t", sp, h->caplen);
2097 		} else {
2098 			/*
2099 			 * Don't include the link-layer header - and if
2100 			 * we have nothing past the link-layer header,
2101 			 * print nothing.
2102 			 */
2103 			if (h->caplen > hdrlen)
2104 				hex_print("\n\t", sp + hdrlen,
2105 				    h->caplen - hdrlen);
2106 		}
2107 	} else if (Aflag) {
2108 		/*
2109 		 * Print the raw packet data in ASCII.
2110 		 */
2111 		if (Aflag > 1) {
2112 			/*
2113 			 * Include the link-layer header.
2114 			 */
2115 			ascii_print(sp, h->caplen);
2116 		} else {
2117 			/*
2118 			 * Don't include the link-layer header - and if
2119 			 * we have nothing past the link-layer header,
2120 			 * print nothing.
2121 			 */
2122 			if (h->caplen > hdrlen)
2123 				ascii_print(sp + hdrlen, h->caplen - hdrlen);
2124 		}
2125 	}
2126 
2127 	putchar('\n');
2128 
2129 	--infodelay;
2130 	if (infoprint)
2131 		info(0);
2132 }
2133 
2134 #ifdef WIN32
2135 	/*
2136 	 * XXX - there should really be libpcap calls to get the version
2137 	 * number as a string (the string would be generated from #defines
2138 	 * at run time, so that it's not generated from string constants
2139 	 * in the library, as, on many UNIX systems, those constants would
2140 	 * be statically linked into the application executable image, and
2141 	 * would thus reflect the version of libpcap on the system on
2142 	 * which the application was *linked*, not the system on which it's
2143 	 * *running*.
2144 	 *
2145 	 * That routine should be documented, unlike the "version[]"
2146 	 * string, so that UNIX vendors providing their own libpcaps
2147 	 * don't omit it (as a couple of vendors have...).
2148 	 *
2149 	 * Packet.dll should perhaps also export a routine to return the
2150 	 * version number of the Packet.dll code, to supply the
2151 	 * "Wpcap_version" information on Windows.
2152 	 */
2153 	char WDversion[]="current-cvs.tcpdump.org";
2154 #if !defined(HAVE_GENERATED_VERSION)
2155 	char version[]="current-cvs.tcpdump.org";
2156 #endif
2157 	char pcap_version[]="current-cvs.tcpdump.org";
2158 	char Wpcap_version[]="3.1";
2159 #endif
2160 
2161 /*
2162  * By default, print the specified data out in hex and ASCII.
2163  */
2164 static void
2165 ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
2166 {
2167 	hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */
2168 }
2169 
2170 void
2171 default_print(const u_char *bp, u_int length)
2172 {
2173 	ndo_default_print(gndo, bp, length);
2174 }
2175 
2176 #ifdef SIGNAL_REQ_INFO
2177 RETSIGTYPE requestinfo(int signo _U_)
2178 {
2179 	if (infodelay)
2180 		++infoprint;
2181 	else
2182 		info(0);
2183 }
2184 #endif
2185 
2186 /*
2187  * Called once each second in verbose mode while dumping to file
2188  */
2189 #ifdef USE_WIN32_MM_TIMER
2190 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
2191 				  DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
2192 {
2193 	struct pcap_stat stat;
2194 
2195 	if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2196 		fprintf(stderr, "Got %u\r", packets_captured);
2197 }
2198 #elif defined(HAVE_ALARM)
2199 static void verbose_stats_dump(int sig _U_)
2200 {
2201 	struct pcap_stat stat;
2202 
2203 	if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2204 		fprintf(stderr, "Got %u\r", packets_captured);
2205 	alarm(1);
2206 }
2207 #endif
2208 
2209 static void
2210 usage(void)
2211 {
2212 	extern char version[];
2213 #ifndef HAVE_PCAP_LIB_VERSION
2214 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
2215 	extern char pcap_version[];
2216 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2217 	static char pcap_version[] = "unknown";
2218 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2219 #endif /* HAVE_PCAP_LIB_VERSION */
2220 
2221 #ifdef HAVE_PCAP_LIB_VERSION
2222 #ifdef WIN32
2223 	(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2224 #else /* WIN32 */
2225 	(void)fprintf(stderr, "%s version %s\n", program_name, version);
2226 #endif /* WIN32 */
2227 	(void)fprintf(stderr, "%s\n",pcap_lib_version());
2228 #else /* HAVE_PCAP_LIB_VERSION */
2229 #ifdef WIN32
2230 	(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2231 	(void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
2232 #else /* WIN32 */
2233 	(void)fprintf(stderr, "%s version %s\n", program_name, version);
2234 	(void)fprintf(stderr, "libpcap version %s\n", pcap_version);
2235 #endif /* WIN32 */
2236 #endif /* HAVE_PCAP_LIB_VERSION */
2237 	(void)fprintf(stderr,
2238 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
2239 	(void)fprintf(stderr,
2240 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
2241 	(void)fprintf(stderr,
2242 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ]\n");
2243 	(void)fprintf(stderr,
2244 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -V file ] [ -w file ]\n");
2245 	(void)fprintf(stderr,
2246 "\t\t[ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
2247 	(void)fprintf(stderr,
2248 "\t\t[ -Z user ] [ expression ]\n");
2249 	exit(1);
2250 }
2251 
2252 
2253 
2254 /* VARARGS */
2255 static void
2256 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
2257 {
2258 	va_list ap;
2259 
2260 	(void)fprintf(stderr, "%s: ", program_name);
2261 	va_start(ap, fmt);
2262 	(void)vfprintf(stderr, fmt, ap);
2263 	va_end(ap);
2264 	if (*fmt) {
2265 		fmt += strlen(fmt);
2266 		if (fmt[-1] != '\n')
2267 			(void)fputc('\n', stderr);
2268 	}
2269 	exit(1);
2270 	/* NOTREACHED */
2271 }
2272 
2273 /* VARARGS */
2274 static void
2275 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
2276 {
2277 	va_list ap;
2278 
2279 	(void)fprintf(stderr, "%s: WARNING: ", program_name);
2280 	va_start(ap, fmt);
2281 	(void)vfprintf(stderr, fmt, ap);
2282 	va_end(ap);
2283 	if (*fmt) {
2284 		fmt += strlen(fmt);
2285 		if (fmt[-1] != '\n')
2286 			(void)fputc('\n', stderr);
2287 	}
2288 }
2289