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