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