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