xref: /freebsd/contrib/tcpdump/tcpdump.c (revision 7447ca0eb235974642312b9555caec00b57d8fc1)
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 #endif
33 
34 /* $FreeBSD$ */
35 
36 /*
37  * tcpdump - monitor tcp/ip traffic on an ethernet.
38  *
39  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
40  * Mercilessly hacked and occasionally improved since then via the
41  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
42  */
43 
44 #ifdef HAVE_CONFIG_H
45 #include "config.h"
46 #endif
47 
48 /*
49  * Mac OS X may ship pcap.h from libpcap 0.6 with a libpcap based on
50  * 0.8.  That means it has pcap_findalldevs() but the header doesn't
51  * define pcap_if_t, meaning that we can't actually *use* pcap_findalldevs().
52  */
53 #ifdef HAVE_PCAP_FINDALLDEVS
54 #ifndef HAVE_PCAP_IF_T
55 #undef HAVE_PCAP_FINDALLDEVS
56 #endif
57 #endif
58 
59 #include <tcpdump-stdinc.h>
60 
61 #ifdef WIN32
62 #include "w32_fzs.h"
63 extern int strcasecmp (const char *__s1, const char *__s2);
64 extern int SIZE_BUF;
65 #define off_t long
66 #define uint UINT
67 #endif /* WIN32 */
68 
69 #ifdef USE_LIBSMI
70 #include <smi.h>
71 #endif
72 
73 #ifdef HAVE_LIBCRYPTO
74 #include <openssl/crypto.h>
75 #endif
76 
77 #ifdef HAVE_GETOPT_LONG
78 #include <getopt.h>
79 #else
80 #include "getopt_long.h"
81 #endif
82 /* Capsicum-specific code requires macros from <net/bpf.h>, which will fail
83  * to compile if <pcap.h> has already been included; including the headers
84  * in the opposite order works fine.
85  */
86 #ifdef __FreeBSD__
87 #include <sys/capsicum.h>
88 #include <sys/sysctl.h>
89 #include <libgen.h>
90 #endif /* __FreeBSD__ */
91 #ifdef HAVE_CASPER
92 #include <libcasper.h>
93 #include <casper/cap_dns.h>
94 #include <sys/nv.h>
95 #include <sys/capability.h>
96 #include <sys/ioccom.h>
97 #include <net/bpf.h>
98 #include <fcntl.h>
99 #endif	/* HAVE_CASPER */
100 #include <pcap.h>
101 #include <signal.h>
102 #include <stdio.h>
103 #include <stdlib.h>
104 #include <string.h>
105 #include <limits.h>
106 #ifndef WIN32
107 #include <sys/wait.h>
108 #include <sys/resource.h>
109 #include <pwd.h>
110 #include <grp.h>
111 #endif /* WIN32 */
112 
113 /* capabilities convenience library */
114 /* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
115  * If HAVE_CAP_NG_H is not defined, undefine HAVE_LIBCAP_NG.
116  * Thus, the later tests are done only on HAVE_LIBCAP_NG.
117  */
118 #ifdef HAVE_LIBCAP_NG
119 #ifdef HAVE_CAP_NG_H
120 #include <cap-ng.h>
121 #else
122 #undef HAVE_LIBCAP_NG
123 #endif /* HAVE_CAP_NG_H */
124 #endif /* HAVE_LIBCAP_NG */
125 
126 #include "netdissect.h"
127 #include "interface.h"
128 #include "addrtoname.h"
129 #include "machdep.h"
130 #include "setsignal.h"
131 #include "gmt2local.h"
132 #include "pcap-missing.h"
133 
134 #ifndef PATH_MAX
135 #define PATH_MAX 1024
136 #endif
137 
138 #ifdef SIGINFO
139 #define SIGNAL_REQ_INFO SIGINFO
140 #elif SIGUSR1
141 #define SIGNAL_REQ_INFO SIGUSR1
142 #endif
143 
144 netdissect_options Gndo;
145 netdissect_options *gndo = &Gndo;
146 
147 static int Dflag;			/* list available devices and exit */
148 static int dflag;			/* print filter code */
149 static int Lflag;			/* list available data link types and exit */
150 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
151 static int Jflag;			/* list available time stamp types */
152 #endif
153 #ifdef HAVE_PCAP_SETDIRECTION
154 int Qflag = -1;				/* restrict captured packet by send/receive direction */
155 #endif
156 static char *zflag = NULL;		/* compress each savefile using a specified command (like gzip or bzip2) */
157 
158 static int infodelay;
159 static int infoprint;
160 
161 char *program_name;
162 
163 #ifdef HAVE_CASPER
164 cap_channel_t *capdns;
165 #endif
166 
167 int32_t thiszone;		/* seconds offset from gmt to local time */
168 
169 /* Forwards */
170 static RETSIGTYPE cleanup(int);
171 static RETSIGTYPE child_cleanup(int);
172 static void print_version(void);
173 static void print_usage(void);
174 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
175 
176 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
177 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
178 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
179 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
180 static void droproot(const char *, const char *);
181 static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
182      __attribute__((noreturn))
183 #ifdef __ATTRIBUTE___FORMAT_OK
184      __attribute__((format (printf, 2, 3)))
185 #endif /* __ATTRIBUTE___FORMAT_OK */
186     ;
187 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...)
188 #ifdef __ATTRIBUTE___FORMAT_OK
189      __attribute__((format (printf, 2, 3)))
190 #endif /* __ATTRIBUTE___FORMAT_OK */
191     ;
192 
193 #ifdef SIGNAL_REQ_INFO
194 RETSIGTYPE requestinfo(int);
195 #endif
196 
197 #if defined(USE_WIN32_MM_TIMER)
198   #include <MMsystem.h>
199   static UINT timer_id;
200   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
201 #elif defined(HAVE_ALARM)
202   static void verbose_stats_dump(int sig);
203 #endif
204 
205 static void info(int);
206 static u_int packets_captured;
207 
208 struct printer {
209         if_printer f;
210 	int type;
211 };
212 
213 
214 struct ndo_printer {
215         if_ndo_printer f;
216 	int type;
217 };
218 
219 
220 static const struct printer printers[] = {
221 	{ NULL,			0 },
222 };
223 
224 static const struct ndo_printer ndo_printers[] = {
225 	{ ether_if_print,	DLT_EN10MB },
226 #ifdef DLT_IPNET
227 	{ ipnet_if_print,	DLT_IPNET },
228 #endif
229 #ifdef DLT_IEEE802_15_4
230 	{ ieee802_15_4_if_print, DLT_IEEE802_15_4 },
231 #endif
232 #ifdef DLT_IEEE802_15_4_NOFCS
233 	{ ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
234 #endif
235 #ifdef DLT_PPI
236 	{ ppi_if_print,		DLT_PPI },
237 #endif
238 #ifdef DLT_NETANALYZER
239 	{ netanalyzer_if_print, DLT_NETANALYZER },
240 #endif
241 #ifdef DLT_NETANALYZER_TRANSPARENT
242 	{ netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
243 #endif
244 #if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
245 	{ nflog_if_print,	DLT_NFLOG},
246 #endif
247 #ifdef DLT_CIP
248 	{ cip_if_print,         DLT_CIP },
249 #endif
250 #ifdef DLT_ATM_CLIP
251 	{ cip_if_print,		DLT_ATM_CLIP },
252 #endif
253 #ifdef DLT_IP_OVER_FC
254 	{ ipfc_if_print,	DLT_IP_OVER_FC },
255 #endif
256 	{ null_if_print,	DLT_NULL },
257 #ifdef DLT_LOOP
258 	{ null_if_print,	DLT_LOOP },
259 #endif
260 #ifdef DLT_APPLE_IP_OVER_IEEE1394
261 	{ ap1394_if_print,	DLT_APPLE_IP_OVER_IEEE1394 },
262 #endif
263 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
264 	{ bt_if_print,		DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
265 #endif
266 #ifdef DLT_LANE8023
267 	{ lane_if_print,        DLT_LANE8023 },
268 #endif
269 	{ arcnet_if_print,	DLT_ARCNET },
270 #ifdef DLT_ARCNET_LINUX
271 	{ arcnet_linux_if_print, DLT_ARCNET_LINUX },
272 #endif
273 	{ raw_if_print,		DLT_RAW },
274 #ifdef DLT_IPV4
275 	{ raw_if_print,		DLT_IPV4 },
276 #endif
277 #ifdef DLT_IPV6
278 	{ raw_if_print,		DLT_IPV6 },
279 #endif
280 #ifdef HAVE_PCAP_USB_H
281 #ifdef DLT_USB_LINUX
282 	{ usb_linux_48_byte_print, DLT_USB_LINUX},
283 #endif /* DLT_USB_LINUX */
284 #ifdef DLT_USB_LINUX_MMAPPED
285 	{ usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
286 #endif /* DLT_USB_LINUX_MMAPPED */
287 #endif /* HAVE_PCAP_USB_H */
288 #ifdef DLT_SYMANTEC_FIREWALL
289 	{ symantec_if_print,	DLT_SYMANTEC_FIREWALL },
290 #endif
291 #ifdef DLT_C_HDLC
292 	{ chdlc_if_print,	DLT_C_HDLC },
293 #endif
294 #ifdef DLT_HDLC
295 	{ chdlc_if_print,	DLT_HDLC },
296 #endif
297 #ifdef DLT_PPP_ETHER
298 	{ pppoe_if_print,	DLT_PPP_ETHER },
299 #endif
300 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
301 	{ pflog_if_print,	DLT_PFLOG },
302 #endif
303 	{ token_if_print,	DLT_IEEE802 },
304 	{ fddi_if_print,	DLT_FDDI },
305 #ifdef DLT_LINUX_SLL
306 	{ sll_if_print,		DLT_LINUX_SLL },
307 #endif
308 #ifdef DLT_FR
309 	{ fr_if_print,		DLT_FR },
310 #endif
311 #ifdef DLT_FRELAY
312 	{ fr_if_print,		DLT_FRELAY },
313 #endif
314 #ifdef DLT_MFR
315 	{ mfr_if_print,		DLT_MFR },
316 #endif
317 	{ atm_if_print,		DLT_ATM_RFC1483 },
318 #ifdef DLT_SUNATM
319 	{ sunatm_if_print,	DLT_SUNATM },
320 #endif
321 #ifdef DLT_ENC
322 	{ enc_if_print,		DLT_ENC },
323 #endif
324 	{ sl_if_print,		DLT_SLIP },
325 #ifdef DLT_SLIP_BSDOS
326 	{ sl_bsdos_if_print,	DLT_SLIP_BSDOS },
327 #endif
328 #ifdef DLT_LTALK
329 	{ ltalk_if_print,	DLT_LTALK },
330 #endif
331 #ifdef DLT_JUNIPER_ATM1
332 	{ juniper_atm1_print,	DLT_JUNIPER_ATM1 },
333 #endif
334 #ifdef DLT_JUNIPER_ATM2
335 	{ juniper_atm2_print,	DLT_JUNIPER_ATM2 },
336 #endif
337 #ifdef DLT_JUNIPER_MFR
338 	{ juniper_mfr_print,	DLT_JUNIPER_MFR },
339 #endif
340 #ifdef DLT_JUNIPER_MLFR
341 	{ juniper_mlfr_print,	DLT_JUNIPER_MLFR },
342 #endif
343 #ifdef DLT_JUNIPER_MLPPP
344 	{ juniper_mlppp_print,	DLT_JUNIPER_MLPPP },
345 #endif
346 #ifdef DLT_JUNIPER_PPPOE
347 	{ juniper_pppoe_print,	DLT_JUNIPER_PPPOE },
348 #endif
349 #ifdef DLT_JUNIPER_PPPOE_ATM
350 	{ juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
351 #endif
352 #ifdef DLT_JUNIPER_GGSN
353 	{ juniper_ggsn_print,	DLT_JUNIPER_GGSN },
354 #endif
355 #ifdef DLT_JUNIPER_ES
356 	{ juniper_es_print,	DLT_JUNIPER_ES },
357 #endif
358 #ifdef DLT_JUNIPER_MONITOR
359 	{ juniper_monitor_print, DLT_JUNIPER_MONITOR },
360 #endif
361 #ifdef DLT_JUNIPER_SERVICES
362 	{ juniper_services_print, DLT_JUNIPER_SERVICES },
363 #endif
364 #ifdef DLT_JUNIPER_ETHER
365 	{ juniper_ether_print,	DLT_JUNIPER_ETHER },
366 #endif
367 #ifdef DLT_JUNIPER_PPP
368 	{ juniper_ppp_print,	DLT_JUNIPER_PPP },
369 #endif
370 #ifdef DLT_JUNIPER_FRELAY
371 	{ juniper_frelay_print,	DLT_JUNIPER_FRELAY },
372 #endif
373 #ifdef DLT_JUNIPER_CHDLC
374 	{ juniper_chdlc_print,	DLT_JUNIPER_CHDLC },
375 #endif
376 #ifdef DLT_PKTAP
377 	{ pktap_if_print,	DLT_PKTAP },
378 #endif
379 #ifdef DLT_IEEE802_11_RADIO
380 	{ ieee802_11_radio_if_print,	DLT_IEEE802_11_RADIO },
381 #endif
382 #ifdef DLT_IEEE802_11
383 	{ ieee802_11_if_print,	DLT_IEEE802_11},
384 #endif
385 #ifdef DLT_IEEE802_11_RADIO_AVS
386 	{ ieee802_11_radio_avs_if_print,	DLT_IEEE802_11_RADIO_AVS },
387 #endif
388 #ifdef DLT_PRISM_HEADER
389 	{ prism_if_print,	DLT_PRISM_HEADER },
390 #endif
391 	{ ppp_if_print,		DLT_PPP },
392 #ifdef DLT_PPP_WITHDIRECTION
393 	{ ppp_if_print,		DLT_PPP_WITHDIRECTION },
394 #endif
395 #ifdef DLT_PPP_BSDOS
396 	{ ppp_bsdos_if_print,	DLT_PPP_BSDOS },
397 #endif
398 #ifdef DLT_PPP_SERIAL
399 	{ ppp_hdlc_if_print,	DLT_PPP_SERIAL },
400 #endif
401 	{ NULL,			0 },
402 };
403 
404 static const struct tok status_flags[] = {
405 #ifdef PCAP_IF_UP
406 	{ PCAP_IF_UP,       "Up"       },
407 #endif
408 #ifdef PCAP_IF_RUNNING
409 	{ PCAP_IF_RUNNING,  "Running"  },
410 #endif
411 	{ PCAP_IF_LOOPBACK, "Loopback" },
412 	{ 0, NULL }
413 };
414 
415 if_printer
416 lookup_printer(int type)
417 {
418 	const struct printer *p;
419 
420 	for (p = printers; p->f; ++p)
421 		if (type == p->type)
422 			return p->f;
423 
424 	return NULL;
425 	/* NOTREACHED */
426 }
427 
428 if_ndo_printer
429 lookup_ndo_printer(int type)
430 {
431 	const struct ndo_printer *p;
432 
433 	for (p = ndo_printers; p->f; ++p)
434 		if (type == p->type)
435 			return p->f;
436 
437 #if defined(DLT_USER2) && defined(DLT_PKTAP)
438 	/*
439 	 * Apple incorrectly chose to use DLT_USER2 for their PKTAP
440 	 * header.
441 	 *
442 	 * We map DLT_PKTAP, whether it's DLT_USER2 as it is on Darwin-
443 	 * based OSes or the same value as LINKTYPE_PKTAP as it is on
444 	 * other OSes, to LINKTYPE_PKTAP, so files written with
445 	 * this version of libpcap for a DLT_PKTAP capture have a link-
446 	 * layer header type of LINKTYPE_PKTAP.
447 	 *
448 	 * However, files written on OS X Mavericks for a DLT_PKTAP
449 	 * capture have a link-layer header type of LINKTYPE_USER2.
450 	 * If we don't have a printer for DLT_USER2, and type is
451 	 * DLT_USER2, we look up the printer for DLT_PKTAP and use
452 	 * that.
453 	 */
454 	if (type == DLT_USER2) {
455 		for (p = ndo_printers; p->f; ++p)
456 			if (DLT_PKTAP == p->type)
457 				return p->f;
458 	}
459 #endif
460 
461 	return NULL;
462 	/* NOTREACHED */
463 }
464 
465 static pcap_t *pd;
466 
467 static int supports_monitor_mode;
468 
469 extern int optind;
470 extern int opterr;
471 extern char *optarg;
472 
473 struct print_info {
474         netdissect_options *ndo;
475         union {
476                 if_printer     printer;
477                 if_ndo_printer ndo_printer;
478         } p;
479         int ndo_type;
480 };
481 
482 struct dump_info {
483 	char	*WFileName;
484 	char	*CurrentFileName;
485 	pcap_t	*pd;
486 	pcap_dumper_t *p;
487 #ifdef __FreeBSD__
488 	int	dirfd;
489 #endif
490 };
491 
492 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
493 static void
494 show_tstamp_types_and_exit(const char *device, pcap_t *pd)
495 {
496 	int n_tstamp_types;
497 	int *tstamp_types = 0;
498 	const char *tstamp_type_name;
499 	int i;
500 
501 	n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
502 	if (n_tstamp_types < 0)
503 		error("%s", pcap_geterr(pd));
504 
505 	if (n_tstamp_types == 0) {
506 		fprintf(stderr, "Time stamp type cannot be set for %s\n",
507 		    device);
508 		exit(0);
509 	}
510 	fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
511 	    device);
512 	for (i = 0; i < n_tstamp_types; i++) {
513 		tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
514 		if (tstamp_type_name != NULL) {
515 			(void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
516 			    pcap_tstamp_type_val_to_description(tstamp_types[i]));
517 		} else {
518 			(void) fprintf(stderr, "  %d\n", tstamp_types[i]);
519 		}
520 	}
521 	pcap_free_tstamp_types(tstamp_types);
522 	exit(0);
523 }
524 #endif
525 
526 static void
527 show_dlts_and_exit(const char *device, pcap_t *pd)
528 {
529 	int n_dlts;
530 	int *dlts = 0;
531 	const char *dlt_name;
532 
533 	n_dlts = pcap_list_datalinks(pd, &dlts);
534 	if (n_dlts < 0)
535 		error("%s", pcap_geterr(pd));
536 	else if (n_dlts == 0 || !dlts)
537 		error("No data link types.");
538 
539 	/*
540 	 * If the interface is known to support monitor mode, indicate
541 	 * whether these are the data link types available when not in
542 	 * monitor mode, if -I wasn't specified, or when in monitor mode,
543 	 * when -I was specified (the link-layer types available in
544 	 * monitor mode might be different from the ones available when
545 	 * not in monitor mode).
546 	 */
547 	if (supports_monitor_mode)
548 		(void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
549 		    device,
550 		    Iflag ? "when in monitor mode" : "when not in monitor mode");
551 	else
552 		(void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
553 		    device);
554 
555 	while (--n_dlts >= 0) {
556 		dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
557 		if (dlt_name != NULL) {
558 			(void) fprintf(stderr, "  %s (%s)", dlt_name,
559 			    pcap_datalink_val_to_description(dlts[n_dlts]));
560 
561 			/*
562 			 * OK, does tcpdump handle that type?
563 			 */
564 			if (lookup_printer(dlts[n_dlts]) == NULL
565                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
566 				(void) fprintf(stderr, " (printing not supported)");
567 			fprintf(stderr, "\n");
568 		} else {
569 			(void) fprintf(stderr, "  DLT %d (printing not supported)\n",
570 			    dlts[n_dlts]);
571 		}
572 	}
573 #ifdef HAVE_PCAP_FREE_DATALINKS
574 	pcap_free_datalinks(dlts);
575 #endif
576 	exit(0);
577 }
578 
579 #ifdef HAVE_PCAP_FINDALLDEVS
580 static void
581 show_devices_and_exit (void)
582 {
583 	pcap_if_t *devpointer;
584 	char ebuf[PCAP_ERRBUF_SIZE];
585 	int i;
586 
587 	if (pcap_findalldevs(&devpointer, ebuf) < 0)
588 		error("%s", ebuf);
589 	else {
590 		for (i = 0; devpointer != NULL; i++) {
591 			printf("%d.%s", i+1, devpointer->name);
592 			if (devpointer->description != NULL)
593 				printf(" (%s)", devpointer->description);
594 			if (devpointer->flags != 0)
595 				printf(" [%s]", bittok2str(status_flags, "none", devpointer->flags));
596 			printf("\n");
597 			devpointer = devpointer->next;
598 		}
599 	}
600 	exit(0);
601 }
602 #endif /* HAVE_PCAP_FINDALLDEVS */
603 
604 /*
605  * Short options.
606  *
607  * Note that there we use all letters for short options except for g, k,
608  * o, and P, and those are used by other versions of tcpdump, and we should
609  * only use them for the same purposes that the other versions of tcpdump
610  * use them:
611  *
612  * OS X tcpdump uses -g to force non--v output for IP to be on one
613  * line, making it more "g"repable;
614  *
615  * OS X tcpdump uses -k tospecify that packet comments in pcap-ng files
616  * should be printed;
617  *
618  * OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
619  * for hosts sending TCP SYN packets;
620  *
621  * OS X tcpdump uses -P to indicate that -w should write pcap-ng rather
622  * than pcap files.
623  *
624  * OS X tcpdump also uses -Q to specify expressions that match packet
625  * metadata, including but not limited to the packet direction.
626  * The expression syntax is different from a simple "in|out|inout",
627  * and those expressions aren't accepted by OS X tcpdump, but the
628  * equivalents would be "in" = "dir=in", "out" = "dir=out", and
629  * "inout" = "dir=in or dir=out", and the parser could conceivably
630  * special-case "in", "out", and "inout" as expressions for backwards
631  * compatibility, so all is not (yet) lost.
632  */
633 
634 /*
635  * Set up flags that might or might not be supported depending on the
636  * version of libpcap we're using.
637  */
638 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
639 #define B_FLAG		"B:"
640 #define B_FLAG_USAGE	" [ -B size ]"
641 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
642 #define B_FLAG
643 #define B_FLAG_USAGE
644 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
645 
646 #ifdef HAVE_PCAP_CREATE
647 #define I_FLAG		"I"
648 #else /* HAVE_PCAP_CREATE */
649 #define I_FLAG
650 #endif /* HAVE_PCAP_CREATE */
651 
652 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
653 #define j_FLAG		"j:"
654 #define j_FLAG_USAGE	" [ -j tstamptype ]"
655 #define J_FLAG		"J"
656 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
657 #define j_FLAG
658 #define j_FLAG_USAGE
659 #define J_FLAG
660 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
661 
662 #ifdef HAVE_PCAP_FINDALLDEVS
663 #define D_FLAG	"D"
664 #else
665 #define D_FLAG
666 #endif
667 
668 #ifdef HAVE_PCAP_DUMP_FLUSH
669 #define U_FLAG	"U"
670 #else
671 #define U_FLAG
672 #endif
673 
674 #ifdef HAVE_PCAP_SETDIRECTION
675 #define Q_FLAG "Q:"
676 #else
677 #define Q_FLAG
678 #endif
679 
680 #define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:Rs:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
681 
682 /*
683  * Long options.
684  *
685  * We do not currently have long options corresponding to all short
686  * options; we should probably pick appropriate option names for them.
687  *
688  * However, the short options where the number of times the option is
689  * specified matters, such as -v and -d and -t, should probably not
690  * just map to a long option, as saying
691  *
692  *  tcpdump --verbose --verbose
693  *
694  * doesn't make sense; it should be --verbosity={N} or something such
695  * as that.
696  *
697  * For long options with no corresponding short options, we define values
698  * outside the range of ASCII graphic characters, make that the last
699  * component of the entry for the long option, and have a case for that
700  * option in the switch statement.
701  */
702 #define OPTION_VERSION		128
703 #define OPTION_TSTAMP_PRECISION	129
704 #define OPTION_IMMEDIATE_MODE	130
705 
706 static const struct option longopts[] = {
707 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
708 	{ "buffer-size", required_argument, NULL, 'B' },
709 #endif
710 	{ "list-interfaces", no_argument, NULL, 'D' },
711 	{ "help", no_argument, NULL, 'h' },
712 	{ "interface", required_argument, NULL, 'i' },
713 #ifdef HAVE_PCAP_CREATE
714 	{ "monitor-mode", no_argument, NULL, 'I' },
715 #endif
716 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
717 	{ "time-stamp-type", required_argument, NULL, 'j' },
718 	{ "list-time-stamp-types", no_argument, NULL, 'J' },
719 #endif
720 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
721 	{ "time-stamp-precision", required_argument, NULL, OPTION_TSTAMP_PRECISION},
722 #endif
723 	{ "dont-verify-checksums", no_argument, NULL, 'K' },
724 	{ "list-data-link-types", no_argument, NULL, 'L' },
725 	{ "no-optimize", no_argument, NULL, 'O' },
726 	{ "no-promiscuous-mode", no_argument, NULL, 'p' },
727 #ifdef HAVE_PCAP_SETDIRECTION
728 	{ "direction", required_argument, NULL, 'Q' },
729 #endif
730 	{ "snapshot-length", required_argument, NULL, 's' },
731 	{ "absolute-tcp-sequence-numbers", no_argument, NULL, 'S' },
732 #ifdef HAVE_PCAP_DUMP_FLUSH
733 	{ "packet-buffered", no_argument, NULL, 'U' },
734 #endif
735 	{ "linktype", required_argument, NULL, 'y' },
736 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
737 	{ "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
738 #endif
739 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
740 	{ "debug-filter-parser", no_argument, NULL, 'Y' },
741 #endif
742 	{ "relinquish-privileges", required_argument, NULL, 'Z' },
743 	{ "number", no_argument, NULL, '#' },
744 	{ "version", no_argument, NULL, OPTION_VERSION },
745 	{ NULL, 0, NULL, 0 }
746 };
747 
748 #ifndef WIN32
749 /* Drop root privileges and chroot if necessary */
750 static void
751 droproot(const char *username, const char *chroot_dir)
752 {
753 	struct passwd *pw = NULL;
754 
755 	if (chroot_dir && !username) {
756 		fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
757 		exit(1);
758 	}
759 
760 	pw = getpwnam(username);
761 	if (pw) {
762 		if (chroot_dir) {
763 			if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
764 				fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
765 				    chroot_dir, pcap_strerror(errno));
766 				exit(1);
767 			}
768 		}
769 #ifdef HAVE_LIBCAP_NG
770 		int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
771 		if (ret < 0) {
772 			fprintf(stderr, "error : ret %d\n", ret);
773 		}
774 		else {
775 			fprintf(stderr, "dropped privs to %s\n", username);
776 		}
777 #else
778 		if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
779 		    setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
780 			fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
781 			    username,
782 			    (unsigned long)pw->pw_uid,
783 			    (unsigned long)pw->pw_gid,
784 			    pcap_strerror(errno));
785 			exit(1);
786 		}
787 		else {
788 			fprintf(stderr, "dropped privs to %s\n", username);
789 		}
790 #endif /* HAVE_LIBCAP_NG */
791 	}
792 	else {
793 		fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
794 		    username);
795 		exit(1);
796 	}
797 #ifdef HAVE_LIBCAP_NG
798 	/* We don't need CAP_SETUID and CAP_SETGID any more. */
799 	capng_updatev(
800 		CAPNG_DROP,
801 		CAPNG_EFFECTIVE | CAPNG_PERMITTED,
802 		CAP_SETUID,
803 		CAP_SETGID,
804 		-1);
805 	capng_apply(CAPNG_SELECT_BOTH);
806 #endif /* HAVE_LIBCAP_NG */
807 
808 }
809 #endif /* WIN32 */
810 
811 static int
812 getWflagChars(int x)
813 {
814 	int c = 0;
815 
816 	x -= 1;
817 	while (x > 0) {
818 		c += 1;
819 		x /= 10;
820 	}
821 
822 	return c;
823 }
824 
825 
826 static void
827 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
828 {
829         char *filename = malloc(PATH_MAX + 1);
830         if (filename == NULL)
831             error("Makefilename: malloc");
832 
833         /* Process with strftime if Gflag is set. */
834         if (Gflag != 0) {
835           struct tm *local_tm;
836 
837           /* Convert Gflag_time to a usable format */
838           if ((local_tm = localtime(&Gflag_time)) == NULL) {
839                   error("MakeTimedFilename: localtime");
840           }
841 
842           /* There's no good way to detect an error in strftime since a return
843            * value of 0 isn't necessarily failure.
844            */
845           strftime(filename, PATH_MAX, orig_name, local_tm);
846         } else {
847           strncpy(filename, orig_name, PATH_MAX);
848         }
849 
850 	if (cnt == 0 && max_chars == 0)
851 		strncpy(buffer, filename, PATH_MAX + 1);
852 	else
853 		if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
854                   /* Report an error if the filename is too large */
855                   error("too many output files or filename is too long (> %d)", PATH_MAX);
856         free(filename);
857 }
858 
859 static int tcpdump_printf(netdissect_options *ndo _U_,
860 			  const char *fmt, ...)
861 {
862 
863   va_list args;
864   int ret;
865 
866   va_start(args, fmt);
867   ret=vfprintf(stdout, fmt, args);
868   va_end(args);
869 
870   return ret;
871 }
872 
873 static struct print_info
874 get_print_info(int type)
875 {
876 	struct print_info printinfo;
877 
878 	printinfo.ndo_type = 1;
879 	printinfo.ndo = gndo;
880 	printinfo.p.ndo_printer = lookup_ndo_printer(type);
881 	if (printinfo.p.ndo_printer == NULL) {
882 		printinfo.p.printer = lookup_printer(type);
883 		printinfo.ndo_type = 0;
884 		if (printinfo.p.printer == NULL) {
885 			gndo->ndo_dltname = pcap_datalink_val_to_name(type);
886 			if (gndo->ndo_dltname != NULL)
887 				error("packet printing is not supported for link type %s: use -w",
888 				      gndo->ndo_dltname);
889 			else
890 				error("packet printing is not supported for link type %d: use -w", type);
891 		}
892 	}
893 	return (printinfo);
894 }
895 
896 static char *
897 get_next_file(FILE *VFile, char *ptr)
898 {
899 	char *ret;
900 
901 	ret = fgets(ptr, PATH_MAX, VFile);
902 	if (!ret)
903 		return NULL;
904 
905 	if (ptr[strlen(ptr) - 1] == '\n')
906 		ptr[strlen(ptr) - 1] = '\0';
907 
908 	return ret;
909 }
910 
911 #ifdef HAVE_CASPER
912 static cap_channel_t *
913 capdns_setup(void)
914 {
915 	cap_channel_t *capcas, *capdnsloc;
916 	const char *types[1];
917 	int families[2];
918 
919 	capcas = cap_init();
920 	if (capcas == NULL)
921 		error("unable to create casper process");
922 	capdnsloc = cap_service_open(capcas, "system.dns");
923 	/* Casper capability no longer needed. */
924 	cap_close(capcas);
925 	if (capdnsloc == NULL)
926 		error("unable to open system.dns service");
927 	/* Limit system.dns to reverse DNS lookups. */
928 	types[0] = "ADDR";
929 	if (cap_dns_type_limit(capdnsloc, types, 1) < 0)
930 		error("unable to limit access to system.dns service");
931 	families[0] = AF_INET;
932 	families[1] = AF_INET6;
933 	if (cap_dns_family_limit(capdnsloc, families, 2) < 0)
934 		error("unable to limit access to system.dns service");
935 
936 	return (capdnsloc);
937 }
938 #endif	/* HAVE_CASPER */
939 
940 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
941 static int
942 tstamp_precision_from_string(const char *precision)
943 {
944 	if (strncmp(precision, "nano", strlen("nano")) == 0)
945 		return PCAP_TSTAMP_PRECISION_NANO;
946 
947 	if (strncmp(precision, "micro", strlen("micro")) == 0)
948 		return PCAP_TSTAMP_PRECISION_MICRO;
949 
950 	return -EINVAL;
951 }
952 
953 static const char *
954 tstamp_precision_to_string(int precision)
955 {
956 	switch (precision) {
957 
958 	case PCAP_TSTAMP_PRECISION_MICRO:
959 		return "micro";
960 
961 	case PCAP_TSTAMP_PRECISION_NANO:
962 		return "nano";
963 
964 	default:
965 		return "unknown";
966 	}
967 }
968 #endif
969 
970 #ifdef __FreeBSD__
971 /*
972  * Ensure that, on a dump file's descriptor, we have all the rights
973  * necessary to make the standard I/O library work with an fdopen()ed
974  * FILE * from that descriptor.
975  *
976  * A long time ago, in a galaxy far far away, AT&T decided that, instead
977  * of providing separate APIs for getting and setting the FD_ flags on a
978  * descriptor, getting and setting the O_ flags on a descriptor, and
979  * locking files, they'd throw them all into a kitchen-sink fcntl() call
980  * along the lines of ioctl(), the fact that ioctl() operations are
981  * largely specific to particular character devices but fcntl() operations
982  * are either generic to all descriptors or generic to all descriptors for
983  * regular files nonwithstanding.
984  *
985  * The Capsicum people decided that fine-grained control of descriptor
986  * operations was required, so that you need to grant permission for
987  * reading, writing, seeking, and fcntl-ing.  The latter, courtesy of
988  * AT&T's decision, means that "fcntl-ing" isn't a thing, but a motley
989  * collection of things, so there are *individual* fcntls for which
990  * permission needs to be granted.
991  *
992  * The FreeBSD standard I/O people implemented some optimizations that
993  * requires that the standard I/O routines be able to determine whether
994  * the descriptor for the FILE * is open append-only or not; as that
995  * descriptor could have come from an open() rather than an fopen(),
996  * that requires that it be able to do an F_GETFL fcntl() to read
997  * the O_ flags.
998  *
999  * Tcpdump uses ftell() to determine how much data has been written
1000  * to a file in order to, when used with -C, determine when it's time
1001  * to rotate capture files.  ftell() therefore needs to do an lseek()
1002  * to find out the file offset and must, thanks to the aforementioned
1003  * optimization, also know whether the descriptor is open append-only
1004  * or not.
1005  *
1006  * The net result of all the above is that we need to grant CAP_SEEK,
1007  * CAP_WRITE, and CAP_FCNTL with the CAP_FCNTL_GETFL subcapability.
1008  *
1009  * Perhaps this is the universe's way of saying that either
1010  *
1011  *	1) there needs to be an fopenat() call and a pcap_dump_openat() call
1012  *	   using it, so that Capsicum-capable tcpdump wouldn't need to do
1013  *	   an fdopen()
1014  *
1015  * or
1016  *
1017  *	2) there needs to be a cap_fdopen() call in the FreeBSD standard
1018  *	   I/O library that knows what rights are needed by the standard
1019  *	   I/O library, based on the open mode, and assigns them, perhaps
1020  *	   with an additional argument indicating, for example, whether
1021  *	   seeking should be allowed, so that tcpdump doesn't need to know
1022  *	   what the standard I/O library happens to require this week.
1023  */
1024 static void
1025 set_dumper_capsicum_rights(pcap_dumper_t *p)
1026 {
1027 	int fd = fileno(pcap_dump_file(p));
1028 	cap_rights_t rights;
1029 
1030 	cap_rights_init(&rights, CAP_SEEK, CAP_WRITE, CAP_FCNTL);
1031 	if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
1032 		error("unable to limit dump descriptor");
1033 	}
1034 	if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS) {
1035 		error("unable to limit dump descriptor fcntls");
1036 	}
1037 }
1038 #endif
1039 
1040 int
1041 main(int argc, char **argv)
1042 {
1043 	register int cnt, op, i;
1044 	bpf_u_int32 localnet =0 , netmask = 0;
1045 	register char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
1046 	pcap_handler callback;
1047 	int type;
1048 	int dlt;
1049 	int new_dlt;
1050 	const char *dlt_name;
1051 	struct bpf_program fcode;
1052 #ifndef WIN32
1053 	RETSIGTYPE (*oldhandler)(int);
1054 #endif
1055 	struct print_info printinfo;
1056 	struct dump_info dumpinfo;
1057 	u_char *pcap_userdata;
1058 	char ebuf[PCAP_ERRBUF_SIZE];
1059 	char VFileLine[PATH_MAX + 1];
1060 	char *username = NULL;
1061 	char *chroot_dir = NULL;
1062 	char *ret = NULL;
1063 	char *end;
1064 #ifdef HAVE_PCAP_FINDALLDEVS
1065 	pcap_if_t *devpointer;
1066 	int devnum;
1067 #endif
1068 	int status;
1069 	FILE *VFile;
1070 #ifdef __FreeBSD__
1071 	cap_rights_t rights;
1072 #endif	/* !__FreeBSD__ */
1073 	int cansandbox;
1074 
1075 #ifdef WIN32
1076 	if(wsockinit() != 0) return 1;
1077 #endif /* WIN32 */
1078 
1079 	jflag=-1;	/* not set */
1080         gndo->ndo_Oflag=1;
1081 	gndo->ndo_Rflag=1;
1082 	gndo->ndo_dlt=-1;
1083 	gndo->ndo_default_print=ndo_default_print;
1084 	gndo->ndo_printf=tcpdump_printf;
1085 	gndo->ndo_error=ndo_error;
1086 	gndo->ndo_warning=ndo_warning;
1087 	gndo->ndo_snaplen = DEFAULT_SNAPLEN;
1088 	gndo->ndo_immediate = 0;
1089 
1090 	cnt = -1;
1091 	device = NULL;
1092 	infile = NULL;
1093 	RFileName = NULL;
1094 	VFileName = NULL;
1095 	VFile = NULL;
1096 	WFileName = NULL;
1097 	dlt = -1;
1098 	if ((cp = strrchr(argv[0], '/')) != NULL)
1099 		program_name = cp + 1;
1100 	else
1101 		program_name = argv[0];
1102 
1103 	/*
1104 	 * On platforms where the CPU doesn't support unaligned loads,
1105 	 * force unaligned accesses to abort with SIGBUS, rather than
1106 	 * being fixed up (slowly) by the OS kernel; on those platforms,
1107 	 * misaligned accesses are bugs, and we want tcpdump to crash so
1108 	 * that the bugs are reported.
1109 	 */
1110 	if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
1111 		error("%s", ebuf);
1112 
1113 #ifdef USE_LIBSMI
1114 	smiInit("tcpdump");
1115 #endif
1116 
1117 	while (
1118 	    (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
1119 		switch (op) {
1120 
1121 		case 'a':
1122 			/* compatibility for old -a */
1123 			break;
1124 
1125 		case 'A':
1126 			++Aflag;
1127 			break;
1128 
1129 		case 'b':
1130 			++bflag;
1131 			break;
1132 
1133 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
1134 		case 'B':
1135 			Bflag = atoi(optarg)*1024;
1136 			if (Bflag <= 0)
1137 				error("invalid packet buffer size %s", optarg);
1138 			break;
1139 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
1140 
1141 		case 'c':
1142 			cnt = atoi(optarg);
1143 			if (cnt <= 0)
1144 				error("invalid packet count %s", optarg);
1145 			break;
1146 
1147 		case 'C':
1148 			Cflag = atoi(optarg) * 1000000;
1149 			if (Cflag < 0)
1150 				error("invalid file size %s", optarg);
1151 			break;
1152 
1153 		case 'd':
1154 			++dflag;
1155 			break;
1156 
1157 		case 'D':
1158 			Dflag++;
1159 			break;
1160 
1161 		case 'L':
1162 			Lflag++;
1163 			break;
1164 
1165 		case 'e':
1166 			++eflag;
1167 			break;
1168 
1169 		case 'E':
1170 #ifndef HAVE_LIBCRYPTO
1171 			warning("crypto code not compiled in");
1172 #endif
1173 			gndo->ndo_espsecret = optarg;
1174 			break;
1175 
1176 		case 'f':
1177 			++fflag;
1178 			break;
1179 
1180 		case 'F':
1181 			infile = optarg;
1182 			break;
1183 
1184 		case 'G':
1185 			Gflag = atoi(optarg);
1186 			if (Gflag < 0)
1187 				error("invalid number of seconds %s", optarg);
1188 
1189                         /* We will create one file initially. */
1190                         Gflag_count = 0;
1191 
1192 			/* Grab the current time for rotation use. */
1193 			if ((Gflag_time = time(NULL)) == (time_t)-1) {
1194 				error("main: can't get current time: %s",
1195 				    pcap_strerror(errno));
1196 			}
1197 			break;
1198 
1199 		case 'h':
1200 			print_usage();
1201 			exit(0);
1202 			break;
1203 
1204 		case 'H':
1205 			++Hflag;
1206 			break;
1207 
1208 		case 'i':
1209 			if (optarg[0] == '0' && optarg[1] == 0)
1210 				error("Invalid adapter index");
1211 
1212 #ifdef HAVE_PCAP_FINDALLDEVS
1213 			/*
1214 			 * If the argument is a number, treat it as
1215 			 * an index into the list of adapters, as
1216 			 * printed by "tcpdump -D".
1217 			 *
1218 			 * This should be OK on UNIX systems, as interfaces
1219 			 * shouldn't have names that begin with digits.
1220 			 * It can be useful on Windows, where more than
1221 			 * one interface can have the same name.
1222 			 */
1223 			devnum = strtol(optarg, &end, 10);
1224 			if (optarg != end && *end == '\0') {
1225 				if (devnum < 0)
1226 					error("Invalid adapter index");
1227 
1228 				if (pcap_findalldevs(&devpointer, ebuf) < 0)
1229 					error("%s", ebuf);
1230 				else {
1231 					/*
1232 					 * Look for the devnum-th entry
1233 					 * in the list of devices
1234 					 * (1-based).
1235 					 */
1236 					for (i = 0;
1237 					    i < devnum-1 && devpointer != NULL;
1238 					    i++, devpointer = devpointer->next)
1239 						;
1240 					if (devpointer == NULL)
1241 						error("Invalid adapter index");
1242 				}
1243 				device = devpointer->name;
1244 				break;
1245 			}
1246 #endif /* HAVE_PCAP_FINDALLDEVS */
1247 			device = optarg;
1248 			break;
1249 
1250 #ifdef HAVE_PCAP_CREATE
1251 		case 'I':
1252 			++Iflag;
1253 			break;
1254 #endif /* HAVE_PCAP_CREATE */
1255 
1256 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1257 		case 'j':
1258 			jflag = pcap_tstamp_type_name_to_val(optarg);
1259 			if (jflag < 0)
1260 				error("invalid time stamp type %s", optarg);
1261 			break;
1262 
1263 		case 'J':
1264 			Jflag++;
1265 			break;
1266 #endif
1267 
1268 		case 'l':
1269 #ifdef WIN32
1270 			/*
1271 			 * _IOLBF is the same as _IOFBF in Microsoft's C
1272 			 * libraries; the only alternative they offer
1273 			 * is _IONBF.
1274 			 *
1275 			 * XXX - this should really be checking for MSVC++,
1276 			 * not WIN32, if, for example, MinGW has its own
1277 			 * C library that is more UNIX-compatible.
1278 			 */
1279 			setvbuf(stdout, NULL, _IONBF, 0);
1280 #else /* WIN32 */
1281 #ifdef HAVE_SETLINEBUF
1282 			setlinebuf(stdout);
1283 #else
1284 			setvbuf(stdout, NULL, _IOLBF, 0);
1285 #endif
1286 #endif /* WIN32 */
1287 			break;
1288 
1289 		case 'K':
1290 			++Kflag;
1291 			break;
1292 
1293 		case 'm':
1294 #ifdef USE_LIBSMI
1295 			if (smiLoadModule(optarg) == 0) {
1296 				error("could not load MIB module %s", optarg);
1297 			}
1298 			sflag = 1;
1299 #else
1300 			(void)fprintf(stderr, "%s: ignoring option `-m %s' ",
1301 				      program_name, optarg);
1302 			(void)fprintf(stderr, "(no libsmi support)\n");
1303 #endif
1304 			break;
1305 
1306 		case 'M':
1307 			/* TCP-MD5 shared secret */
1308 #ifndef HAVE_LIBCRYPTO
1309 			warning("crypto code not compiled in");
1310 #endif
1311 			sigsecret = optarg;
1312 			break;
1313 
1314 		case 'n':
1315 			++nflag;
1316 			break;
1317 
1318 		case 'N':
1319 			++Nflag;
1320 			break;
1321 
1322 		case 'O':
1323 			Oflag = 0;
1324 			break;
1325 
1326 		case 'p':
1327 			++pflag;
1328 			break;
1329 
1330 		case 'q':
1331 			++qflag;
1332 			++suppress_default_print;
1333 			break;
1334 
1335 #ifdef HAVE_PCAP_SETDIRECTION
1336 		case 'Q':
1337 			if (strcasecmp(optarg, "in") == 0)
1338 				Qflag = PCAP_D_IN;
1339 			else if (strcasecmp(optarg, "out") == 0)
1340 				Qflag = PCAP_D_OUT;
1341 			else if (strcasecmp(optarg, "inout") == 0)
1342 				Qflag = PCAP_D_INOUT;
1343 			else
1344 				error("unknown capture direction `%s'", optarg);
1345 			break;
1346 #endif /* HAVE_PCAP_SETDIRECTION */
1347 
1348 		case 'r':
1349 			RFileName = optarg;
1350 			break;
1351 
1352 		case 'R':
1353 			Rflag = 0;
1354 			break;
1355 
1356 		case 's':
1357 			snaplen = strtol(optarg, &end, 0);
1358 			if (optarg == end || *end != '\0'
1359 			    || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
1360 				error("invalid snaplen %s", optarg);
1361 			else if (snaplen == 0)
1362 				snaplen = MAXIMUM_SNAPLEN;
1363 			break;
1364 
1365 		case 'S':
1366 			++Sflag;
1367 			break;
1368 
1369 		case 't':
1370 			++tflag;
1371 			break;
1372 
1373 		case 'T':
1374 			if (strcasecmp(optarg, "vat") == 0)
1375 				packettype = PT_VAT;
1376 			else if (strcasecmp(optarg, "wb") == 0)
1377 				packettype = PT_WB;
1378 			else if (strcasecmp(optarg, "rpc") == 0)
1379 				packettype = PT_RPC;
1380 			else if (strcasecmp(optarg, "rtp") == 0)
1381 				packettype = PT_RTP;
1382 			else if (strcasecmp(optarg, "rtcp") == 0)
1383 				packettype = PT_RTCP;
1384 			else if (strcasecmp(optarg, "snmp") == 0)
1385 				packettype = PT_SNMP;
1386 			else if (strcasecmp(optarg, "cnfp") == 0)
1387 				packettype = PT_CNFP;
1388 			else if (strcasecmp(optarg, "tftp") == 0)
1389 				packettype = PT_TFTP;
1390 			else if (strcasecmp(optarg, "aodv") == 0)
1391 				packettype = PT_AODV;
1392 			else if (strcasecmp(optarg, "carp") == 0)
1393 				packettype = PT_CARP;
1394 			else if (strcasecmp(optarg, "radius") == 0)
1395 				packettype = PT_RADIUS;
1396 			else if (strcasecmp(optarg, "zmtp1") == 0)
1397 				packettype = PT_ZMTP1;
1398 			else if (strcasecmp(optarg, "vxlan") == 0)
1399 				packettype = PT_VXLAN;
1400 			else if (strcasecmp(optarg, "pgm") == 0)
1401 				packettype = PT_PGM;
1402 			else if (strcasecmp(optarg, "pgm_zmtp1") == 0)
1403 				packettype = PT_PGM_ZMTP1;
1404 			else if (strcasecmp(optarg, "lmp") == 0)
1405 				packettype = PT_LMP;
1406 			else
1407 				error("unknown packet type `%s'", optarg);
1408 			break;
1409 
1410 		case 'u':
1411 			++uflag;
1412 			break;
1413 
1414 #ifdef HAVE_PCAP_DUMP_FLUSH
1415 		case 'U':
1416 			++Uflag;
1417 			break;
1418 #endif
1419 
1420 		case 'v':
1421 			++vflag;
1422 			break;
1423 
1424 		case 'V':
1425 			VFileName = optarg;
1426 			break;
1427 
1428 		case 'w':
1429 			WFileName = optarg;
1430 			break;
1431 
1432 		case 'W':
1433 			Wflag = atoi(optarg);
1434 			if (Wflag < 0)
1435 				error("invalid number of output files %s", optarg);
1436 			WflagChars = getWflagChars(Wflag);
1437 			break;
1438 
1439 		case 'x':
1440 			++xflag;
1441 			++suppress_default_print;
1442 			break;
1443 
1444 		case 'X':
1445 			++Xflag;
1446 			++suppress_default_print;
1447 			break;
1448 
1449 		case 'y':
1450 			gndo->ndo_dltname = optarg;
1451 			gndo->ndo_dlt =
1452 			  pcap_datalink_name_to_val(gndo->ndo_dltname);
1453 			if (gndo->ndo_dlt < 0)
1454 				error("invalid data link type %s", gndo->ndo_dltname);
1455 			break;
1456 
1457 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
1458 		case 'Y':
1459 			{
1460 			/* Undocumented flag */
1461 #ifdef HAVE_PCAP_DEBUG
1462 			extern int pcap_debug;
1463 			pcap_debug = 1;
1464 #else
1465 			extern int yydebug;
1466 			yydebug = 1;
1467 #endif
1468 			}
1469 			break;
1470 #endif
1471 		case 'z':
1472 			zflag = strdup(optarg);
1473 			break;
1474 
1475 		case 'Z':
1476 			username = strdup(optarg);
1477 			break;
1478 
1479 		case '#':
1480 			gndo->ndo_packet_number = 1;
1481 			break;
1482 
1483 		case OPTION_VERSION:
1484 			print_version();
1485 			exit(0);
1486 			break;
1487 
1488 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1489 		case OPTION_TSTAMP_PRECISION:
1490 			gndo->ndo_tstamp_precision = tstamp_precision_from_string(optarg);
1491 			if (gndo->ndo_tstamp_precision < 0)
1492 				error("unsupported time stamp precision");
1493 			break;
1494 #endif
1495 
1496 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1497 		case OPTION_IMMEDIATE_MODE:
1498 			gndo->ndo_immediate = 1;
1499 			break;
1500 #endif
1501 
1502 		default:
1503 			print_usage();
1504 			exit(1);
1505 			/* NOTREACHED */
1506 		}
1507 
1508 #ifdef HAVE_PCAP_FINDALLDEVS
1509 	if (Dflag)
1510 		show_devices_and_exit();
1511 #endif
1512 
1513 	switch (tflag) {
1514 
1515 	case 0: /* Default */
1516 	case 4: /* Default + Date*/
1517 		thiszone = gmt2local(0);
1518 		break;
1519 
1520 	case 1: /* No time stamp */
1521 	case 2: /* Unix timeval style */
1522 	case 3: /* Microseconds since previous packet */
1523         case 5: /* Microseconds since first packet */
1524 		break;
1525 
1526 	default: /* Not supported */
1527 		error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1528 		break;
1529 	}
1530 
1531 	if (fflag != 0 && (VFileName != NULL || RFileName != NULL))
1532 		error("-f can not be used with -V or -r");
1533 
1534 	if (VFileName != NULL && RFileName != NULL)
1535 		error("-V and -r are mutually exclusive.");
1536 
1537 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1538 	/*
1539 	 * If we're printing dissected packets to the standard output
1540 	 * rather than saving raw packets to a file, and the standard
1541 	 * output is a terminal, use immediate mode, as the user's
1542 	 * probably expecting to see packets pop up immediately.
1543 	 */
1544 	if (WFileName == NULL && isatty(1))
1545 		gndo->ndo_immediate = 1;
1546 #endif
1547 
1548 #ifdef WITH_CHROOT
1549 	/* if run as root, prepare for chrooting */
1550 	if (getuid() == 0 || geteuid() == 0) {
1551 		/* future extensibility for cmd-line arguments */
1552 		if (!chroot_dir)
1553 			chroot_dir = WITH_CHROOT;
1554 	}
1555 #endif
1556 
1557 #ifdef WITH_USER
1558 	/* if run as root, prepare for dropping root privileges */
1559 	if (getuid() == 0 || geteuid() == 0) {
1560 		/* Run with '-Z root' to restore old behaviour */
1561 		if (!username)
1562 			username = WITH_USER;
1563 	}
1564 #endif
1565 
1566 	if (RFileName != NULL || VFileName != NULL) {
1567 		/*
1568 		 * If RFileName is non-null, it's the pathname of a
1569 		 * savefile to read.  If VFileName is non-null, it's
1570 		 * the pathname of a file containing a list of pathnames
1571 		 * (one per line) of savefiles to read.
1572 		 *
1573 		 * In either case, we're reading a savefile, not doing
1574 		 * a live capture.
1575 		 */
1576 #ifndef WIN32
1577 		/*
1578 		 * We don't need network access, so relinquish any set-UID
1579 		 * or set-GID privileges we have (if any).
1580 		 *
1581 		 * We do *not* want set-UID privileges when opening a
1582 		 * trace file, as that might let the user read other
1583 		 * people's trace files (especially if we're set-UID
1584 		 * root).
1585 		 */
1586 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1587 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
1588 #endif /* WIN32 */
1589 		if (VFileName != NULL) {
1590 			if (VFileName[0] == '-' && VFileName[1] == '\0')
1591 				VFile = stdin;
1592 			else
1593 				VFile = fopen(VFileName, "r");
1594 
1595 			if (VFile == NULL)
1596 				error("Unable to open file: %s\n", strerror(errno));
1597 
1598 			ret = get_next_file(VFile, VFileLine);
1599 			if (!ret)
1600 				error("Nothing in %s\n", VFileName);
1601 			RFileName = VFileLine;
1602 		}
1603 
1604 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1605 		pd = pcap_open_offline_with_tstamp_precision(RFileName,
1606 		    gndo->ndo_tstamp_precision, ebuf);
1607 #else
1608 		pd = pcap_open_offline(RFileName, ebuf);
1609 #endif
1610 
1611 		if (pd == NULL)
1612 			error("%s", ebuf);
1613 #ifdef HAVE_CASPER
1614 		cap_rights_init(&rights, CAP_READ);
1615 		if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
1616 		    errno != ENOSYS) {
1617 			error("unable to limit pcap descriptor");
1618 		}
1619 #endif
1620 		dlt = pcap_datalink(pd);
1621 		dlt_name = pcap_datalink_val_to_name(dlt);
1622 		if (dlt_name == NULL) {
1623 			fprintf(stderr, "reading from file %s, link-type %u\n",
1624 			    RFileName, dlt);
1625 		} else {
1626 			fprintf(stderr,
1627 			    "reading from file %s, link-type %s (%s)\n",
1628 			    RFileName, dlt_name,
1629 			    pcap_datalink_val_to_description(dlt));
1630 		}
1631 	} else {
1632 		/*
1633 		 * We're doing a live capture.
1634 		 */
1635 		if (device == NULL) {
1636 			device = pcap_lookupdev(ebuf);
1637 			if (device == NULL)
1638 				error("%s", ebuf);
1639 		}
1640 #ifdef WIN32
1641 		/*
1642 		 * Print a message to the standard error on Windows.
1643 		 * XXX - why do it here, with a different message?
1644 		 */
1645 		if(strlen(device) == 1)	/* we assume that an ASCII string is always longer than 1 char */
1646 		{						/* a Unicode string has a \0 as second byte (so strlen() is 1) */
1647 			fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1648 		}
1649 		else
1650 		{
1651 			fprintf(stderr, "%s: listening on %s\n", program_name, device);
1652 		}
1653 
1654 		fflush(stderr);
1655 #endif /* WIN32 */
1656 #ifdef HAVE_PCAP_CREATE
1657 		pd = pcap_create(device, ebuf);
1658 		if (pd == NULL)
1659 			error("%s", ebuf);
1660 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1661 		if (Jflag)
1662 			show_tstamp_types_and_exit(device, pd);
1663 #endif
1664 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1665 		status = pcap_set_tstamp_precision(pd, gndo->ndo_tstamp_precision);
1666 		if (status != 0)
1667 			error("%s: Can't set %ssecond time stamp precision: %s",
1668 				device,
1669 				tstamp_precision_to_string(gndo->ndo_tstamp_precision),
1670 				pcap_statustostr(status));
1671 #endif
1672 
1673 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1674 		if (gndo->ndo_immediate) {
1675 			status = pcap_set_immediate_mode(pd, 1);
1676 			if (status != 0)
1677 				error("%s: Can't set immediate mode: %s",
1678 				device,
1679 				pcap_statustostr(status));
1680 		}
1681 #endif
1682 		/*
1683 		 * Is this an interface that supports monitor mode?
1684 		 */
1685 		if (pcap_can_set_rfmon(pd) == 1)
1686 			supports_monitor_mode = 1;
1687 		else
1688 			supports_monitor_mode = 0;
1689 		status = pcap_set_snaplen(pd, snaplen);
1690 		if (status != 0)
1691 			error("%s: Can't set snapshot length: %s",
1692 			    device, pcap_statustostr(status));
1693 		status = pcap_set_promisc(pd, !pflag);
1694 		if (status != 0)
1695 			error("%s: Can't set promiscuous mode: %s",
1696 			    device, pcap_statustostr(status));
1697 		if (Iflag) {
1698 			status = pcap_set_rfmon(pd, 1);
1699 			if (status != 0)
1700 				error("%s: Can't set monitor mode: %s",
1701 				    device, pcap_statustostr(status));
1702 		}
1703 		status = pcap_set_timeout(pd, 1000);
1704 		if (status != 0)
1705 			error("%s: pcap_set_timeout failed: %s",
1706 			    device, pcap_statustostr(status));
1707 		if (Bflag != 0) {
1708 			status = pcap_set_buffer_size(pd, Bflag);
1709 			if (status != 0)
1710 				error("%s: Can't set buffer size: %s",
1711 				    device, pcap_statustostr(status));
1712 		}
1713 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1714                 if (jflag != -1) {
1715 			status = pcap_set_tstamp_type(pd, jflag);
1716 			if (status < 0)
1717 				error("%s: Can't set time stamp type: %s",
1718 			              device, pcap_statustostr(status));
1719 		}
1720 #endif
1721 		status = pcap_activate(pd);
1722 		if (status < 0) {
1723 			/*
1724 			 * pcap_activate() failed.
1725 			 */
1726 			cp = pcap_geterr(pd);
1727 			if (status == PCAP_ERROR)
1728 				error("%s", cp);
1729 			else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1730 			          status == PCAP_ERROR_PERM_DENIED) &&
1731 			         *cp != '\0')
1732 				error("%s: %s\n(%s)", device,
1733 				    pcap_statustostr(status), cp);
1734 #ifdef __FreeBSD__
1735 			else if (status == PCAP_ERROR_RFMON_NOTSUP &&
1736 			    strncmp(device, "wlan", 4) == 0) {
1737 				char parent[8], newdev[8];
1738 				char sysctl[32];
1739 				size_t s = sizeof(parent);
1740 
1741 				snprintf(sysctl, sizeof(sysctl),
1742 				    "net.wlan.%d.%%parent", atoi(device + 4));
1743 				sysctlbyname(sysctl, parent, &s, NULL, 0);
1744 				strlcpy(newdev, device, sizeof(newdev));
1745 				/* Suggest a new wlan device. */
1746 				newdev[strlen(newdev)-1]++;
1747 				error("%s is not a monitor mode VAP\n"
1748 				    "To create a new monitor mode VAP use:\n"
1749 				    "  ifconfig %s create wlandev %s wlanmode "
1750 				    "monitor\nand use %s as the tcpdump "
1751 				    "interface", device, newdev, parent,
1752 				    newdev);
1753 			}
1754 #endif
1755 			else
1756 				error("%s: %s", device,
1757 				    pcap_statustostr(status));
1758 		} else if (status > 0) {
1759 			/*
1760 			 * pcap_activate() succeeded, but it's warning us
1761 			 * of a problem it had.
1762 			 */
1763 			cp = pcap_geterr(pd);
1764 			if (status == PCAP_WARNING)
1765 				warning("%s", cp);
1766 			else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1767 			         *cp != '\0')
1768 				warning("%s: %s\n(%s)", device,
1769 				    pcap_statustostr(status), cp);
1770 			else
1771 				warning("%s: %s", device,
1772 				    pcap_statustostr(status));
1773 		}
1774 #ifdef HAVE_PCAP_SETDIRECTION
1775 		if (Qflag != -1) {
1776 			status = pcap_setdirection(pd, Qflag);
1777 			if (status != 0)
1778 				error("%s: pcap_setdirection() failed: %s",
1779 				      device,  pcap_geterr(pd));
1780 		}
1781 #endif /* HAVE_PCAP_SETDIRECTION */
1782 #else
1783 		*ebuf = '\0';
1784 		pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1785 		if (pd == NULL)
1786 			error("%s", ebuf);
1787 		else if (*ebuf)
1788 			warning("%s", ebuf);
1789 #endif /* HAVE_PCAP_CREATE */
1790 		/*
1791 		 * Let user own process after socket has been opened.
1792 		 */
1793 #ifndef WIN32
1794 		if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1795 			fprintf(stderr, "Warning: setgid/setuid failed !\n");
1796 #endif /* WIN32 */
1797 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1798 		if(Bflag != 0)
1799 			if(pcap_setbuff(pd, Bflag)==-1){
1800 				error("%s", pcap_geterr(pd));
1801 			}
1802 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1803 		if (Lflag)
1804 			show_dlts_and_exit(device, pd);
1805 		if (gndo->ndo_dlt >= 0) {
1806 #ifdef HAVE_PCAP_SET_DATALINK
1807 			if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1808 				error("%s", pcap_geterr(pd));
1809 #else
1810 			/*
1811 			 * We don't actually support changing the
1812 			 * data link type, so we only let them
1813 			 * set it to what it already is.
1814 			 */
1815 			if (gndo->ndo_dlt != pcap_datalink(pd)) {
1816 				error("%s is not one of the DLTs supported by this device\n",
1817 				      gndo->ndo_dltname);
1818 			}
1819 #endif
1820 			(void)fprintf(stderr, "%s: data link type %s\n",
1821 				      program_name, gndo->ndo_dltname);
1822 			(void)fflush(stderr);
1823 		}
1824 		i = pcap_snapshot(pd);
1825 		if (snaplen < i) {
1826 			warning("snaplen raised from %d to %d", snaplen, i);
1827 			snaplen = i;
1828 		}
1829                 if(fflag != 0) {
1830                         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1831                                 warning("foreign (-f) flag used but: %s", ebuf);
1832                         }
1833                 }
1834 
1835 	}
1836 	if (infile)
1837 		cmdbuf = read_infile(infile);
1838 	else
1839 		cmdbuf = copy_argv(&argv[optind]);
1840 
1841 	if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1842 		error("%s", pcap_geterr(pd));
1843 	if (dflag) {
1844 		bpf_dump(&fcode, dflag);
1845 		pcap_close(pd);
1846 		free(cmdbuf);
1847 		exit(0);
1848 	}
1849 
1850 #ifdef HAVE_CASPER
1851 	if (!nflag)
1852 		capdns = capdns_setup();
1853 #endif	/* HAVE_CASPER */
1854 
1855 	init_addrtoname(gndo, localnet, netmask);
1856         init_checksum();
1857 
1858 #ifndef WIN32
1859 	(void)setsignal(SIGPIPE, cleanup);
1860 	(void)setsignal(SIGTERM, cleanup);
1861 	(void)setsignal(SIGINT, cleanup);
1862 #endif /* WIN32 */
1863 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1864 	(void)setsignal(SIGCHLD, child_cleanup);
1865 #endif
1866 	/* Cooperate with nohup(1) */
1867 #ifndef WIN32
1868 	if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1869 		(void)setsignal(SIGHUP, oldhandler);
1870 #endif /* WIN32 */
1871 
1872 #ifndef WIN32
1873 	/*
1874 	 * If a user name was specified with "-Z", attempt to switch to
1875 	 * that user's UID.  This would probably be used with sudo,
1876 	 * to allow tcpdump to be run in a special restricted
1877 	 * account (if you just want to allow users to open capture
1878 	 * devices, and can't just give users that permission,
1879 	 * you'd make tcpdump set-UID or set-GID).
1880 	 *
1881 	 * Tcpdump doesn't necessarily write only to one savefile;
1882 	 * the general only way to allow a -Z instance to write to
1883 	 * savefiles as the user under whose UID it's run, rather
1884 	 * than as the user specified with -Z, would thus be to switch
1885 	 * to the original user ID before opening a capture file and
1886 	 * then switch back to the -Z user ID after opening the savefile.
1887 	 * Switching to the -Z user ID only after opening the first
1888 	 * savefile doesn't handle the general case.
1889 	 */
1890 
1891 	if (getuid() == 0 || geteuid() == 0) {
1892 #ifdef HAVE_LIBCAP_NG
1893 		/* Initialize capng */
1894 		capng_clear(CAPNG_SELECT_BOTH);
1895 		if (username) {
1896 			capng_updatev(
1897 				CAPNG_ADD,
1898 				CAPNG_PERMITTED | CAPNG_EFFECTIVE,
1899 				CAP_SETUID,
1900 				CAP_SETGID,
1901 				-1);
1902 		}
1903 
1904 		if (WFileName) {
1905 			capng_update(
1906 				CAPNG_ADD,
1907 				CAPNG_PERMITTED | CAPNG_EFFECTIVE,
1908 				CAP_DAC_OVERRIDE
1909 				);
1910 		}
1911 		capng_apply(CAPNG_SELECT_BOTH);
1912 #endif /* HAVE_LIBCAP_NG */
1913 		if (username || chroot_dir)
1914 			droproot(username, chroot_dir);
1915 
1916 	}
1917 #endif /* WIN32 */
1918 
1919 	if (pcap_setfilter(pd, &fcode) < 0)
1920 		error("%s", pcap_geterr(pd));
1921 #ifdef HAVE_CASPER
1922 	if (RFileName == NULL && VFileName == NULL) {
1923 		static const unsigned long cmds[] = { BIOCGSTATS };
1924 
1925 		/*
1926 		 * The various libpcap devices use a combination of
1927 		 * read (bpf), ioctl (bpf, netmap), poll (netmap).
1928 		 * Grant the relevant access rights, sorted by name.
1929 		 */
1930 		cap_rights_init(&rights, CAP_EVENT, CAP_IOCTL, CAP_READ);
1931 		if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
1932 		    errno != ENOSYS) {
1933 			error("unable to limit pcap descriptor");
1934 		}
1935 		if (cap_ioctls_limit(pcap_fileno(pd), cmds,
1936 		    sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
1937 			error("unable to limit ioctls on pcap descriptor");
1938 		}
1939 	}
1940 #endif
1941 	if (WFileName) {
1942 		pcap_dumper_t *p;
1943 		/* Do not exceed the default PATH_MAX for files. */
1944 		dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
1945 
1946 		if (dumpinfo.CurrentFileName == NULL)
1947 			error("malloc of dumpinfo.CurrentFileName");
1948 
1949 		/* We do not need numbering for dumpfiles if Cflag isn't set. */
1950 		if (Cflag != 0)
1951 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1952 		else
1953 		  MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1954 
1955 		p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1956 #ifdef HAVE_LIBCAP_NG
1957 		/* Give up CAP_DAC_OVERRIDE capability.
1958 		 * Only allow it to be restored if the -C or -G flag have been
1959 		 * set since we may need to create more files later on.
1960 		 */
1961 		capng_update(
1962 			CAPNG_DROP,
1963 			(Cflag || Gflag ? 0 : CAPNG_PERMITTED)
1964 				| CAPNG_EFFECTIVE,
1965 			CAP_DAC_OVERRIDE
1966 			);
1967 		capng_apply(CAPNG_SELECT_BOTH);
1968 #endif /* HAVE_LIBCAP_NG */
1969 		if (p == NULL)
1970 			error("%s", pcap_geterr(pd));
1971 #ifdef __FreeBSD__
1972 		set_dumper_capsicum_rights(p);
1973 #endif
1974 		if (Cflag != 0 || Gflag != 0) {
1975 #ifdef __FreeBSD__
1976 			dumpinfo.WFileName = strdup(basename(WFileName));
1977 			dumpinfo.dirfd = open(dirname(WFileName),
1978 			    O_DIRECTORY | O_RDONLY);
1979 			if (dumpinfo.dirfd < 0) {
1980 				error("unable to open directory %s",
1981 				    dirname(WFileName));
1982 			}
1983 			cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
1984 			    CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
1985 			if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
1986 			    errno != ENOSYS) {
1987 				error("unable to limit directory rights");
1988 			}
1989 			if (cap_fcntls_limit(dumpinfo.dirfd, CAP_FCNTL_GETFL) < 0 &&
1990 			    errno != ENOSYS) {
1991 				error("unable to limit dump descriptor fcntls");
1992 			}
1993 #else	/* !__FreeBSD__ */
1994 			dumpinfo.WFileName = WFileName;
1995 #endif
1996 			callback = dump_packet_and_trunc;
1997 			dumpinfo.pd = pd;
1998 			dumpinfo.p = p;
1999 			pcap_userdata = (u_char *)&dumpinfo;
2000 		} else {
2001 			callback = dump_packet;
2002 			pcap_userdata = (u_char *)p;
2003 		}
2004 #ifdef HAVE_PCAP_DUMP_FLUSH
2005 		if (Uflag)
2006 			pcap_dump_flush(p);
2007 #endif
2008 	} else {
2009 		type = pcap_datalink(pd);
2010 		printinfo = get_print_info(type);
2011 		callback = print_packet;
2012 		pcap_userdata = (u_char *)&printinfo;
2013 	}
2014 
2015 #ifdef SIGNAL_REQ_INFO
2016 	/*
2017 	 * We can't get statistics when reading from a file rather
2018 	 * than capturing from a device.
2019 	 */
2020 	if (RFileName == NULL)
2021 		(void)setsignal(SIGNAL_REQ_INFO, requestinfo);
2022 #endif
2023 
2024 	if (vflag > 0 && WFileName) {
2025 		/*
2026 		 * When capturing to a file, "-v" means tcpdump should,
2027 		 * every 10 secodns, "v"erbosely report the number of
2028 		 * packets captured.
2029 		 */
2030 #ifdef USE_WIN32_MM_TIMER
2031 		/* call verbose_stats_dump() each 1000 +/-100msec */
2032 		timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
2033 		setvbuf(stderr, NULL, _IONBF, 0);
2034 #elif defined(HAVE_ALARM)
2035 		(void)setsignal(SIGALRM, verbose_stats_dump);
2036 		alarm(1);
2037 #endif
2038 	}
2039 
2040 #ifndef WIN32
2041 	if (RFileName == NULL) {
2042 		/*
2043 		 * Live capture (if -V was specified, we set RFileName
2044 		 * to a file from the -V file).  Print a message to
2045 		 * the standard error on UN*X.
2046 		 */
2047 		if (!vflag && !WFileName) {
2048 			(void)fprintf(stderr,
2049 			    "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
2050 			    program_name);
2051 		} else
2052 			(void)fprintf(stderr, "%s: ", program_name);
2053 		dlt = pcap_datalink(pd);
2054 		dlt_name = pcap_datalink_val_to_name(dlt);
2055 		if (dlt_name == NULL) {
2056 			(void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
2057 			    device, dlt, snaplen);
2058 		} else {
2059 			(void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
2060 			    device, dlt_name,
2061 			    pcap_datalink_val_to_description(dlt), snaplen);
2062 		}
2063 		(void)fflush(stderr);
2064 	}
2065 #endif /* WIN32 */
2066 
2067 #ifdef __FreeBSD__
2068 	cansandbox = (VFileName == NULL && zflag == NULL);
2069 #ifdef HAVE_CASPER
2070 	cansandbox = (cansandbox && (nflag || capdns != NULL));
2071 #else
2072 	cansandbox = (cansandbox && nflag);
2073 #endif
2074 	if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
2075 		error("unable to enter the capability mode");
2076 #endif	/* __FreeBSD__ */
2077 
2078 	do {
2079 		status = pcap_loop(pd, cnt, callback, pcap_userdata);
2080 		if (WFileName == NULL) {
2081 			/*
2082 			 * We're printing packets.  Flush the printed output,
2083 			 * so it doesn't get intermingled with error output.
2084 			 */
2085 			if (status == -2) {
2086 				/*
2087 				 * We got interrupted, so perhaps we didn't
2088 				 * manage to finish a line we were printing.
2089 				 * Print an extra newline, just in case.
2090 				 */
2091 				putchar('\n');
2092 			}
2093 			(void)fflush(stdout);
2094 		}
2095                 if (status == -2) {
2096 			/*
2097 			 * We got interrupted. If we are reading multiple
2098 			 * files (via -V) set these so that we stop.
2099 			 */
2100 			VFileName = NULL;
2101 			ret = NULL;
2102 		}
2103 		if (status == -1) {
2104 			/*
2105 			 * Error.  Report it.
2106 			 */
2107 			(void)fprintf(stderr, "%s: pcap_loop: %s\n",
2108 			    program_name, pcap_geterr(pd));
2109 		}
2110 		if (RFileName == NULL) {
2111 			/*
2112 			 * We're doing a live capture.  Report the capture
2113 			 * statistics.
2114 			 */
2115 			info(1);
2116 		}
2117 		pcap_close(pd);
2118 		if (VFileName != NULL) {
2119 			ret = get_next_file(VFile, VFileLine);
2120 			if (ret) {
2121 				RFileName = VFileLine;
2122 				pd = pcap_open_offline(RFileName, ebuf);
2123 				if (pd == NULL)
2124 					error("%s", ebuf);
2125 #ifdef HAVE_CASPER
2126 				cap_rights_init(&rights, CAP_READ);
2127 				if (cap_rights_limit(fileno(pcap_file(pd)),
2128 				    &rights) < 0 && errno != ENOSYS) {
2129 					error("unable to limit pcap descriptor");
2130 				}
2131 #endif
2132 				new_dlt = pcap_datalink(pd);
2133 				if (WFileName && new_dlt != dlt)
2134 					error("%s: new dlt does not match original", RFileName);
2135 				printinfo = get_print_info(new_dlt);
2136 				dlt_name = pcap_datalink_val_to_name(new_dlt);
2137 				if (dlt_name == NULL) {
2138 					fprintf(stderr, "reading from file %s, link-type %u\n",
2139 					RFileName, new_dlt);
2140 				} else {
2141 					fprintf(stderr,
2142 					"reading from file %s, link-type %s (%s)\n",
2143 					RFileName, dlt_name,
2144 					pcap_datalink_val_to_description(new_dlt));
2145 				}
2146 				if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2147 					error("%s", pcap_geterr(pd));
2148 				if (pcap_setfilter(pd, &fcode) < 0)
2149 					error("%s", pcap_geterr(pd));
2150 			}
2151 		}
2152 	}
2153 	while (ret != NULL);
2154 
2155 	free(cmdbuf);
2156 	exit(status == -1 ? 1 : 0);
2157 }
2158 
2159 /* make a clean exit on interrupts */
2160 static RETSIGTYPE
2161 cleanup(int signo _U_)
2162 {
2163 #ifdef USE_WIN32_MM_TIMER
2164 	if (timer_id)
2165 		timeKillEvent(timer_id);
2166 	timer_id = 0;
2167 #elif defined(HAVE_ALARM)
2168 	alarm(0);
2169 #endif
2170 
2171 #ifdef HAVE_PCAP_BREAKLOOP
2172 	/*
2173 	 * We have "pcap_breakloop()"; use it, so that we do as little
2174 	 * as possible in the signal handler (it's probably not safe
2175 	 * to do anything with standard I/O streams in a signal handler -
2176 	 * the ANSI C standard doesn't say it is).
2177 	 */
2178 	pcap_breakloop(pd);
2179 #else
2180 	/*
2181 	 * We don't have "pcap_breakloop()"; this isn't safe, but
2182 	 * it's the best we can do.  Print the summary if we're
2183 	 * not reading from a savefile - i.e., if we're doing a
2184 	 * live capture - and exit.
2185 	 */
2186 	if (pd != NULL && pcap_file(pd) == NULL) {
2187 		/*
2188 		 * We got interrupted, so perhaps we didn't
2189 		 * manage to finish a line we were printing.
2190 		 * Print an extra newline, just in case.
2191 		 */
2192 		putchar('\n');
2193 		(void)fflush(stdout);
2194 		info(1);
2195 	}
2196 	exit(0);
2197 #endif
2198 }
2199 
2200 /*
2201   On windows, we do not use a fork, so we do not care less about
2202   waiting a child processes to die
2203  */
2204 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2205 static RETSIGTYPE
2206 child_cleanup(int signo _U_)
2207 {
2208   wait(NULL);
2209 }
2210 #endif /* HAVE_FORK && HAVE_VFORK */
2211 
2212 static void
2213 info(register int verbose)
2214 {
2215 	struct pcap_stat stat;
2216 
2217 	/*
2218 	 * Older versions of libpcap didn't set ps_ifdrop on some
2219 	 * platforms; initialize it to 0 to handle that.
2220 	 */
2221 	stat.ps_ifdrop = 0;
2222 	if (pcap_stats(pd, &stat) < 0) {
2223 		(void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
2224 		infoprint = 0;
2225 		return;
2226 	}
2227 
2228 	if (!verbose)
2229 		fprintf(stderr, "%s: ", program_name);
2230 
2231 	(void)fprintf(stderr, "%u packet%s captured", packets_captured,
2232 	    PLURAL_SUFFIX(packets_captured));
2233 	if (!verbose)
2234 		fputs(", ", stderr);
2235 	else
2236 		putc('\n', stderr);
2237 	(void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
2238 	    PLURAL_SUFFIX(stat.ps_recv));
2239 	if (!verbose)
2240 		fputs(", ", stderr);
2241 	else
2242 		putc('\n', stderr);
2243 	(void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
2244 	    PLURAL_SUFFIX(stat.ps_drop));
2245 	if (stat.ps_ifdrop != 0) {
2246 		if (!verbose)
2247 			fputs(", ", stderr);
2248 		else
2249 			putc('\n', stderr);
2250 		(void)fprintf(stderr, "%u packet%s dropped by interface\n",
2251 		    stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
2252 	} else
2253 		putc('\n', stderr);
2254 	infoprint = 0;
2255 }
2256 
2257 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2258 static void
2259 compress_savefile(const char *filename)
2260 {
2261 # ifdef HAVE_FORK
2262 	if (fork())
2263 # else
2264 	if (vfork())
2265 # endif
2266 		return;
2267 	/*
2268 	 * Set to lowest priority so that this doesn't disturb the capture
2269 	 */
2270 #ifdef NZERO
2271 	setpriority(PRIO_PROCESS, 0, NZERO - 1);
2272 #else
2273 	setpriority(PRIO_PROCESS, 0, 19);
2274 #endif
2275 	if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
2276 		fprintf(stderr,
2277 			"compress_savefile:execlp(%s, %s): %s\n",
2278 			zflag,
2279 			filename,
2280 			strerror(errno));
2281 # ifdef HAVE_FORK
2282 	exit(1);
2283 # else
2284 	_exit(1);
2285 # endif
2286 }
2287 #else  /* HAVE_FORK && HAVE_VFORK */
2288 static void
2289 compress_savefile(const char *filename)
2290 {
2291 	fprintf(stderr,
2292 		"compress_savefile failed. Functionality not implemented under your system\n");
2293 }
2294 #endif /* HAVE_FORK && HAVE_VFORK */
2295 
2296 static void
2297 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2298 {
2299 	struct dump_info *dump_info;
2300 
2301 	++packets_captured;
2302 
2303 	++infodelay;
2304 
2305 	dump_info = (struct dump_info *)user;
2306 
2307 	/*
2308 	 * XXX - this won't force the file to rotate on the specified time
2309 	 * boundary, but it will rotate on the first packet received after the
2310 	 * specified Gflag number of seconds. Note: if a Gflag time boundary
2311 	 * and a Cflag size boundary coincide, the time rotation will occur
2312 	 * first thereby cancelling the Cflag boundary (since the file should
2313 	 * be 0).
2314 	 */
2315 	if (Gflag != 0) {
2316 		/* Check if it is time to rotate */
2317 		time_t t;
2318 
2319 		/* Get the current time */
2320 		if ((t = time(NULL)) == (time_t)-1) {
2321 			error("dump_and_trunc_packet: can't get current_time: %s",
2322 			    pcap_strerror(errno));
2323 		}
2324 
2325 
2326 		/* If the time is greater than the specified window, rotate */
2327 		if (t - Gflag_time >= Gflag) {
2328 #ifdef __FreeBSD__
2329 			FILE *fp;
2330 			int fd;
2331 #endif
2332 
2333 			/* Update the Gflag_time */
2334 			Gflag_time = t;
2335 			/* Update Gflag_count */
2336 			Gflag_count++;
2337 			/*
2338 			 * Close the current file and open a new one.
2339 			 */
2340 			pcap_dump_close(dump_info->p);
2341 
2342 			/*
2343 			 * Compress the file we just closed, if the user asked for it
2344 			 */
2345 			if (zflag != NULL)
2346 				compress_savefile(dump_info->CurrentFileName);
2347 
2348 			/*
2349 			 * Check to see if we've exceeded the Wflag (when
2350 			 * not using Cflag).
2351 			 */
2352 			if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
2353 				(void)fprintf(stderr, "Maximum file limit reached: %d\n",
2354 				    Wflag);
2355 				exit(0);
2356 				/* NOTREACHED */
2357 			}
2358 			if (dump_info->CurrentFileName != NULL)
2359 				free(dump_info->CurrentFileName);
2360 			/* Allocate space for max filename + \0. */
2361 			dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2362 			if (dump_info->CurrentFileName == NULL)
2363 				error("dump_packet_and_trunc: malloc");
2364 			/*
2365 			 * Gflag was set otherwise we wouldn't be here. Reset the count
2366 			 * so multiple files would end with 1,2,3 in the filename.
2367 			 * The counting is handled with the -C flow after this.
2368 			 */
2369 			Cflag_count = 0;
2370 
2371 			/*
2372 			 * This is always the first file in the Cflag
2373 			 * rotation: e.g. 0
2374 			 * We also don't need numbering if Cflag is not set.
2375 			 */
2376 			if (Cflag != 0)
2377 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
2378 				    WflagChars);
2379 			else
2380 				MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
2381 
2382 #ifdef HAVE_LIBCAP_NG
2383 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2384 			capng_apply(CAPNG_SELECT_BOTH);
2385 #endif /* HAVE_LIBCAP_NG */
2386 #ifdef __FreeBSD__
2387 			fd = openat(dump_info->dirfd,
2388 			    dump_info->CurrentFileName,
2389 			    O_CREAT | O_WRONLY | O_TRUNC, 0644);
2390 			if (fd < 0) {
2391 				error("unable to open file %s",
2392 				    dump_info->CurrentFileName);
2393 			}
2394 			fp = fdopen(fd, "w");
2395 			if (fp == NULL) {
2396 				error("unable to fdopen file %s",
2397 				    dump_info->CurrentFileName);
2398 			}
2399 			dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2400 #else	/* !__FreeBSD__ */
2401 			dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2402 #endif
2403 #ifdef HAVE_LIBCAP_NG
2404 			capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2405 			capng_apply(CAPNG_SELECT_BOTH);
2406 #endif /* HAVE_LIBCAP_NG */
2407 			if (dump_info->p == NULL)
2408 				error("%s", pcap_geterr(pd));
2409 #ifdef __FreeBSD__
2410 			set_dumper_capsicum_rights(dump_info->p);
2411 #endif
2412 		}
2413 	}
2414 
2415 	/*
2416 	 * XXX - this won't prevent capture files from getting
2417 	 * larger than Cflag - the last packet written to the
2418 	 * file could put it over Cflag.
2419 	 */
2420 	if (Cflag != 0) {
2421 		long size = pcap_dump_ftell(dump_info->p);
2422 
2423 		if (size == -1)
2424 			error("ftell fails on output file");
2425 		if (size > Cflag) {
2426 #ifdef __FreeBSD__
2427 			FILE *fp;
2428 			int fd;
2429 #endif
2430 
2431 			/*
2432 			 * Close the current file and open a new one.
2433 			 */
2434 			pcap_dump_close(dump_info->p);
2435 
2436 			/*
2437 			 * Compress the file we just closed, if the user
2438 			 * asked for it.
2439 			 */
2440 			if (zflag != NULL)
2441 				compress_savefile(dump_info->CurrentFileName);
2442 
2443 			Cflag_count++;
2444 			if (Wflag > 0) {
2445 				if (Cflag_count >= Wflag)
2446 					Cflag_count = 0;
2447 			}
2448 			if (dump_info->CurrentFileName != NULL)
2449 				free(dump_info->CurrentFileName);
2450 			dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2451 			if (dump_info->CurrentFileName == NULL)
2452 				error("dump_packet_and_trunc: malloc");
2453 			MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
2454 #ifdef HAVE_LIBCAP_NG
2455 			capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2456 			capng_apply(CAPNG_SELECT_BOTH);
2457 #endif /* HAVE_LIBCAP_NG */
2458 #ifdef __FreeBSD__
2459 			fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
2460 			    O_CREAT | O_WRONLY | O_TRUNC, 0644);
2461 			if (fd < 0) {
2462 				error("unable to open file %s",
2463 				    dump_info->CurrentFileName);
2464 			}
2465 			fp = fdopen(fd, "w");
2466 			if (fp == NULL) {
2467 				error("unable to fdopen file %s",
2468 				    dump_info->CurrentFileName);
2469 			}
2470 			dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2471 #else	/* !__FreeBSD__ */
2472 			dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2473 #endif
2474 #ifdef HAVE_LIBCAP_NG
2475 			capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2476 			capng_apply(CAPNG_SELECT_BOTH);
2477 #endif /* HAVE_LIBCAP_NG */
2478 			if (dump_info->p == NULL)
2479 				error("%s", pcap_geterr(pd));
2480 #ifdef __FreeBSD__
2481 			set_dumper_capsicum_rights(dump_info->p);
2482 #endif
2483 		}
2484 	}
2485 
2486 	pcap_dump((u_char *)dump_info->p, h, sp);
2487 #ifdef HAVE_PCAP_DUMP_FLUSH
2488 	if (Uflag)
2489 		pcap_dump_flush(dump_info->p);
2490 #endif
2491 
2492 	--infodelay;
2493 	if (infoprint)
2494 		info(0);
2495 }
2496 
2497 static void
2498 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2499 {
2500 	++packets_captured;
2501 
2502 	++infodelay;
2503 
2504 	pcap_dump(user, h, sp);
2505 #ifdef HAVE_PCAP_DUMP_FLUSH
2506 	if (Uflag)
2507 		pcap_dump_flush((pcap_dumper_t *)user);
2508 #endif
2509 
2510 	--infodelay;
2511 	if (infoprint)
2512 		info(0);
2513 }
2514 
2515 static void
2516 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2517 {
2518 	struct print_info *print_info;
2519 	u_int hdrlen;
2520         netdissect_options *ndo;
2521 
2522 	++packets_captured;
2523 
2524 	++infodelay;
2525 
2526 	print_info = (struct print_info *)user;
2527         ndo = print_info->ndo;
2528 
2529 	if(ndo->ndo_packet_number)
2530 		ND_PRINT((ndo, "%5u  ", packets_captured));
2531 
2532 	ts_print(ndo, &h->ts);
2533 
2534 	/*
2535 	 * Some printers want to check that they're not walking off the
2536 	 * end of the packet.
2537 	 * Rather than pass it all the way down, we set this member
2538 	 * of the netdissect_options structure.
2539 	 */
2540 	ndo->ndo_snapend = sp + h->caplen;
2541 
2542         if(print_info->ndo_type) {
2543                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
2544         } else {
2545                 hdrlen = (*print_info->p.printer)(h, sp);
2546         }
2547 
2548 	/*
2549 	 * Restore the original snapend, as a printer might have
2550 	 * changed it.
2551 	 */
2552 	ndo->ndo_snapend = sp + h->caplen;
2553 	if (ndo->ndo_Xflag) {
2554 		/*
2555 		 * Print the raw packet data in hex and ASCII.
2556 		 */
2557 		if (ndo->ndo_Xflag > 1) {
2558 			/*
2559 			 * Include the link-layer header.
2560 			 */
2561 			hex_and_ascii_print(ndo, "\n\t", sp, h->caplen);
2562 		} else {
2563 			/*
2564 			 * Don't include the link-layer header - and if
2565 			 * we have nothing past the link-layer header,
2566 			 * print nothing.
2567 			 */
2568 			if (h->caplen > hdrlen)
2569 				hex_and_ascii_print(ndo, "\n\t", sp + hdrlen,
2570 				    h->caplen - hdrlen);
2571 		}
2572 	} else if (ndo->ndo_xflag) {
2573 		/*
2574 		 * Print the raw packet data in hex.
2575 		 */
2576 		if (ndo->ndo_xflag > 1) {
2577 			/*
2578 			 * Include the link-layer header.
2579 			 */
2580                         hex_print(ndo, "\n\t", sp, h->caplen);
2581 		} else {
2582 			/*
2583 			 * Don't include the link-layer header - and if
2584 			 * we have nothing past the link-layer header,
2585 			 * print nothing.
2586 			 */
2587 			if (h->caplen > hdrlen)
2588 				hex_print(ndo, "\n\t", sp + hdrlen,
2589                                           h->caplen - hdrlen);
2590 		}
2591 	} else if (ndo->ndo_Aflag) {
2592 		/*
2593 		 * Print the raw packet data in ASCII.
2594 		 */
2595 		if (ndo->ndo_Aflag > 1) {
2596 			/*
2597 			 * Include the link-layer header.
2598 			 */
2599 			ascii_print(ndo, sp, h->caplen);
2600 		} else {
2601 			/*
2602 			 * Don't include the link-layer header - and if
2603 			 * we have nothing past the link-layer header,
2604 			 * print nothing.
2605 			 */
2606 			if (h->caplen > hdrlen)
2607 				ascii_print(ndo, sp + hdrlen, h->caplen - hdrlen);
2608 		}
2609 	}
2610 
2611 	putchar('\n');
2612 
2613 	--infodelay;
2614 	if (infoprint)
2615 		info(0);
2616 }
2617 
2618 #ifdef WIN32
2619 	/*
2620 	 * XXX - there should really be libpcap calls to get the version
2621 	 * number as a string (the string would be generated from #defines
2622 	 * at run time, so that it's not generated from string constants
2623 	 * in the library, as, on many UNIX systems, those constants would
2624 	 * be statically linked into the application executable image, and
2625 	 * would thus reflect the version of libpcap on the system on
2626 	 * which the application was *linked*, not the system on which it's
2627 	 * *running*.
2628 	 *
2629 	 * That routine should be documented, unlike the "version[]"
2630 	 * string, so that UNIX vendors providing their own libpcaps
2631 	 * don't omit it (as a couple of vendors have...).
2632 	 *
2633 	 * Packet.dll should perhaps also export a routine to return the
2634 	 * version number of the Packet.dll code, to supply the
2635 	 * "Wpcap_version" information on Windows.
2636 	 */
2637 	char WDversion[]="current-git.tcpdump.org";
2638 #if !defined(HAVE_GENERATED_VERSION)
2639 	char version[]="current-git.tcpdump.org";
2640 #endif
2641 	char pcap_version[]="current-git.tcpdump.org";
2642 	char Wpcap_version[]="3.1";
2643 #endif
2644 
2645 /*
2646  * By default, print the specified data out in hex and ASCII.
2647  */
2648 static void
2649 ndo_default_print(netdissect_options *ndo, const u_char *bp, u_int length)
2650 {
2651 	hex_and_ascii_print(ndo, "\n\t", bp, length); /* pass on lf and indentation string */
2652 }
2653 
2654 void
2655 default_print(const u_char *bp, u_int length)
2656 {
2657 	ndo_default_print(gndo, bp, length);
2658 }
2659 
2660 #ifdef SIGNAL_REQ_INFO
2661 RETSIGTYPE requestinfo(int signo _U_)
2662 {
2663 	if (infodelay)
2664 		++infoprint;
2665 	else
2666 		info(0);
2667 }
2668 #endif
2669 
2670 /*
2671  * Called once each second in verbose mode while dumping to file
2672  */
2673 #ifdef USE_WIN32_MM_TIMER
2674 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
2675 				  DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
2676 {
2677 	struct pcap_stat stat;
2678 
2679 	if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2680 		fprintf(stderr, "Got %u\r", packets_captured);
2681 }
2682 #elif defined(HAVE_ALARM)
2683 static void verbose_stats_dump(int sig _U_)
2684 {
2685 	struct pcap_stat stat;
2686 
2687 	if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2688 		fprintf(stderr, "Got %u\r", packets_captured);
2689 	alarm(1);
2690 }
2691 #endif
2692 
2693 USES_APPLE_DEPRECATED_API
2694 static void
2695 print_version(void)
2696 {
2697 	extern char version[];
2698 #ifndef HAVE_PCAP_LIB_VERSION
2699 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
2700 	extern char pcap_version[];
2701 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2702 	static char pcap_version[] = "unknown";
2703 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2704 #endif /* HAVE_PCAP_LIB_VERSION */
2705 
2706 #ifdef HAVE_PCAP_LIB_VERSION
2707 #ifdef WIN32
2708 	(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2709 #else /* WIN32 */
2710 	(void)fprintf(stderr, "%s version %s\n", program_name, version);
2711 #endif /* WIN32 */
2712 	(void)fprintf(stderr, "%s\n",pcap_lib_version());
2713 #else /* HAVE_PCAP_LIB_VERSION */
2714 #ifdef WIN32
2715 	(void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2716 	(void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
2717 #else /* WIN32 */
2718 	(void)fprintf(stderr, "%s version %s\n", program_name, version);
2719 	(void)fprintf(stderr, "libpcap version %s\n", pcap_version);
2720 #endif /* WIN32 */
2721 #endif /* HAVE_PCAP_LIB_VERSION */
2722 
2723 #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
2724 	(void)fprintf (stderr, "%s\n", SSLeay_version(SSLEAY_VERSION));
2725 #endif
2726 
2727 #ifdef USE_LIBSMI
2728 	(void)fprintf (stderr, "SMI-library: %s\n", smi_version_string);
2729 #endif
2730 }
2731 USES_APPLE_RST
2732 
2733 static void
2734 print_usage(void)
2735 {
2736 	print_version();
2737 	(void)fprintf(stderr,
2738 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ]\n", program_name);
2739 	(void)fprintf(stderr,
2740 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
2741 	(void)fprintf(stderr,
2742 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ] [ --number ]\n");
2743 #ifdef HAVE_PCAP_SETDIRECTION
2744 	(void)fprintf(stderr,
2745 "\t\t[ -Q in|out|inout ]\n");
2746 #endif
2747 	(void)fprintf(stderr,
2748 "\t\t[ -r file ] [ -s snaplen ] ");
2749 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
2750 	(void)fprintf(stderr, "[ --time-stamp-precision precision ]\n");
2751 	(void)fprintf(stderr,
2752 "\t\t");
2753 #endif
2754 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
2755 	(void)fprintf(stderr, "[ --immediate-mode ] ");
2756 #endif
2757 	(void)fprintf(stderr, "[ -T type ] [ --version ] [ -V file ]\n");
2758 	(void)fprintf(stderr,
2759 "\t\t[ -w file ] [ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
2760 	(void)fprintf(stderr,
2761 "\t\t[ -Z user ] [ expression ]\n");
2762 }
2763 
2764 
2765 
2766 /* VARARGS */
2767 static void
2768 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
2769 {
2770 	va_list ap;
2771 
2772 	(void)fprintf(stderr, "%s: ", program_name);
2773 	va_start(ap, fmt);
2774 	(void)vfprintf(stderr, fmt, ap);
2775 	va_end(ap);
2776 	if (*fmt) {
2777 		fmt += strlen(fmt);
2778 		if (fmt[-1] != '\n')
2779 			(void)fputc('\n', stderr);
2780 	}
2781 	exit(1);
2782 	/* NOTREACHED */
2783 }
2784 
2785 /* VARARGS */
2786 static void
2787 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
2788 {
2789 	va_list ap;
2790 
2791 	(void)fprintf(stderr, "%s: WARNING: ", program_name);
2792 	va_start(ap, fmt);
2793 	(void)vfprintf(stderr, fmt, ap);
2794 	va_end(ap);
2795 	if (*fmt) {
2796 		fmt += strlen(fmt);
2797 		if (fmt[-1] != '\n')
2798 			(void)fputc('\n', stderr);
2799 	}
2800 }
2801 /*
2802  * Local Variables:
2803  * c-style: whitesmith
2804  * c-basic-offset: 8
2805  * End:
2806  */
2807