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from Pekka Savola <[email protected]>:
[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 static const char rcsid[] _U_ =
33 "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.233 2004-02-26 08:47:27 hannes 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 <pwd.h>
69 #include <grp.h>
70
71 #include "interface.h"
72 #include "addrtoname.h"
73 #include "machdep.h"
74 #include "setsignal.h"
75 #include "gmt2local.h"
76 #include "pcap-missing.h"
77
78 int dflag; /* print filter code */
79 int eflag; /* print ethernet header */
80 int fflag; /* don't translate "foreign" IP address */
81 static int Lflag; /* list available data link types and exit */
82 int nflag; /* leave addresses as numbers */
83 int Nflag; /* remove domains from printed host names */
84 static int Oflag = 1; /* run filter code optimizer */
85 static int pflag; /* don't go promiscuous */
86 int qflag; /* quick (shorter) output */
87 int Rflag = 1; /* print sequence # field in AH/ESP*/
88 int sflag = 0; /* use the libsmi to translate OIDs */
89 int Sflag; /* print raw TCP sequence numbers */
90 int tflag = 1; /* print packet arrival time */
91 int Uflag = 0; /* "unbuffered" output of dump files */
92 int uflag = 0; /* Print undecoded NFS handles */
93 int vflag; /* verbose */
94 int xflag; /* print packet in hex */
95 int Xflag; /* print packet in ascii as well as hex */
96 static off_t Cflag = 0; /* rotate dump files after this many bytes */
97 int Aflag = 0; /* print packet only in ascii observing LF, CR, TAB, SPACE */
98 static int dlt = -1; /* if != -1, ask libpcap for the DLT it names */
99 static int Cflag_count = 0; /* Keep track of which file number we're writing */
100 static int Wflag = 0; /* recycle output files after this number of files */
101 static int WflagChars = 0;
102
103 /*
104 * Define the maximum number of files for the -C flag, and how many
105 * characters can be added to a filename for the -C flag (which
106 * should be enough to handle MAX_CFLAG - 1).
107 */
108 #define MAX_CFLAG 1000000
109 #define MAX_CFLAG_CHARS 6
110
111 const char *dlt_name = NULL;
112
113 char *espsecret = NULL; /* ESP secret key */
114
115 int packettype;
116
117 static int infodelay;
118 static int infoprint;
119
120 char *program_name;
121
122 int32_t thiszone; /* seconds offset from gmt to local time */
123
124 /* Forwards */
125 static RETSIGTYPE cleanup(int);
126 static void usage(void) __attribute__((noreturn));
127 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
128
129 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
130 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
131 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
132 static void droproot(const char *, const char *);
133
134 #ifdef SIGINFO
135 RETSIGTYPE requestinfo(int);
136 #endif
137
138 #if defined(USE_WIN32_MM_TIMER)
139 #include <MMsystem.h>
140 static UINT timer_id;
141 static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
142 #elif defined(HAVE_ALARM)
143 static void verbose_stats_dump(int sig);
144 #endif
145
146 static void info(int);
147 static u_int packets_captured;
148
149 /* Length of saved portion of packet. */
150 int snaplen = DEFAULT_SNAPLEN;
151
152 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
153
154 struct printer {
155 if_printer f;
156 int type;
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 { ether_if_print, DLT_EN10MB },
165 { token_if_print, DLT_IEEE802 },
166 #ifdef DLT_LANE8023
167 { lane_if_print, DLT_LANE8023 },
168 #endif
169 #ifdef DLT_CIP
170 { cip_if_print, DLT_CIP },
171 #endif
172 #ifdef DLT_ATM_CLIP
173 { cip_if_print, DLT_ATM_CLIP },
174 #endif
175 { sl_if_print, DLT_SLIP },
176 #ifdef DLT_SLIP_BSDOS
177 { sl_bsdos_if_print, DLT_SLIP_BSDOS },
178 #endif
179 { ppp_if_print, DLT_PPP },
180 #ifdef DLT_PPP_BSDOS
181 { ppp_bsdos_if_print, DLT_PPP_BSDOS },
182 #endif
183 { fddi_if_print, DLT_FDDI },
184 { null_if_print, DLT_NULL },
185 #ifdef DLT_LOOP
186 { null_if_print, DLT_LOOP },
187 #endif
188 { raw_if_print, DLT_RAW },
189 { atm_if_print, DLT_ATM_RFC1483 },
190 #ifdef DLT_C_HDLC
191 { chdlc_if_print, DLT_C_HDLC },
192 #endif
193 #ifdef DLT_HDLC
194 { chdlc_if_print, DLT_HDLC },
195 #endif
196 #ifdef DLT_PPP_SERIAL
197 { ppp_hdlc_if_print, DLT_PPP_SERIAL },
198 #endif
199 #ifdef DLT_PPP_ETHER
200 { pppoe_if_print, DLT_PPP_ETHER },
201 #endif
202 #ifdef DLT_LINUX_SLL
203 { sll_if_print, DLT_LINUX_SLL },
204 #endif
205 #ifdef DLT_IEEE802_11
206 { ieee802_11_if_print, DLT_IEEE802_11},
207 #endif
208 #ifdef DLT_LTALK
209 { ltalk_if_print, DLT_LTALK },
210 #endif
211 #ifdef DLT_PFLOG
212 { pflog_if_print, DLT_PFLOG },
213 #endif
214 #ifdef DLT_FR
215 { fr_if_print, DLT_FR },
216 #endif
217 #ifdef DLT_FRELAY
218 { fr_if_print, DLT_FRELAY },
219 #endif
220 #ifdef DLT_SUNATM
221 { sunatm_if_print, DLT_SUNATM },
222 #endif
223 #ifdef DLT_IP_OVER_FC
224 { ipfc_if_print, DLT_IP_OVER_FC },
225 #endif
226 #ifdef DLT_PRISM_HEADER
227 { prism_if_print, DLT_PRISM_HEADER },
228 #endif
229 #ifdef DLT_IEEE802_11_RADIO
230 { ieee802_11_radio_if_print, DLT_IEEE802_11_RADIO },
231 #endif
232 #ifdef DLT_ENC
233 { enc_if_print, DLT_ENC },
234 #endif
235 { NULL, 0 },
236 };
237
238 static if_printer
239 lookup_printer(int type)
240 {
241 struct printer *p;
242
243 for (p = printers; p->f; ++p)
244 if (type == p->type)
245 return p->f;
246
247 return NULL;
248 /* NOTREACHED */
249 }
250
251 static pcap_t *pd;
252
253 extern int optind;
254 extern int opterr;
255 extern char *optarg;
256
257 struct print_info {
258 if_printer printer;
259 };
260
261 struct dump_info {
262 char *WFileName;
263 pcap_t *pd;
264 pcap_dumper_t *p;
265 };
266
267 static void
268 show_dlts_and_exit(pcap_t *pd)
269 {
270 int n_dlts;
271 int *dlts = 0;
272 const char *dlt_name;
273
274 n_dlts = pcap_list_datalinks(pd, &dlts);
275 if (n_dlts < 0)
276 error("%s", pcap_geterr(pd));
277 else if (n_dlts == 0 || !dlts)
278 error("No data link types.");
279
280 (void) fprintf(stderr, "Data link types (use option -y to set):\n");
281
282 while (--n_dlts >= 0) {
283 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
284 if (dlt_name != NULL) {
285 (void) fprintf(stderr, " %s (%s)", dlt_name,
286 pcap_datalink_val_to_description(dlts[n_dlts]));
287
288 /*
289 * OK, does tcpdump handle that type?
290 */
291 if (lookup_printer(dlts[n_dlts]) == NULL)
292 (void) fprintf(stderr, " (not supported)");
293 putchar('\n');
294 } else {
295 (void) fprintf(stderr, " DLT %d (not supported)\n",
296 dlts[n_dlts]);
297 }
298 }
299 free(dlts);
300 exit(0);
301 }
302
303 /*
304 * Set up flags that might or might not be supported depending on the
305 * version of libpcap we're using.
306 */
307 #ifdef WIN32
308 #define B_FLAG "B:"
309 #define B_FLAG_USAGE " [ -B size ]"
310 #else /* WIN32 */
311 #define B_FLAG
312 #define B_FLAG_USAGE
313 #endif /* WIN32 */
314
315 #ifdef HAVE_PCAP_FINDALLDEVS
316 #define D_FLAG "D"
317 #else
318 #define D_FLAG
319 #endif
320
321 #ifdef HAVE_PCAP_DUMP_FLUSH
322 #define U_FLAG "U"
323 #else
324 #define U_FLAG
325 #endif
326
327 /* Drop root privileges and chroot if necessary */
328 static void
329 droproot(const char *username, const char *chroot_dir)
330 {
331 struct passwd *pw = NULL;
332
333 if (chroot_dir && !username) {
334 fprintf(stderr, "Chroot without dropping root is insecure\n");
335 exit(1);
336 }
337
338 pw = getpwnam(username);
339 if (pw) {
340 if (chroot_dir) {
341 if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
342 fprintf(stderr, "Couldn't chroot/chdir to '%.64s'\n", chroot_dir);
343 exit(1);
344 }
345 }
346 if (initgroups(pw->pw_name, pw->pw_gid) != 0 || setgid(pw->pw_gid) != 0 ||
347 setuid(pw->pw_uid) != 0) {
348 fprintf(stderr, "Couldn't change to '%.32s' uid=%d gid=%d\n", username,
349 pw->pw_uid, pw->pw_gid);
350 exit(1);
351 }
352 }
353 else {
354 fprintf(stderr, "Couldn't find user '%.32s'\n", username);
355 exit(1);
356 }
357 }
358
359 static int
360 getWflagChars(int x)
361 {
362 int c = 0;
363
364 x -= 1;
365 while (x > 0) {
366 c += 1;
367 x /= 10;
368 }
369
370 return c;
371 }
372
373
374 static void
375 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
376 {
377 if (cnt == 0 && max_chars == 0)
378 strcpy(buffer, orig_name);
379 else
380 sprintf(buffer, "%s%0*d", orig_name, max_chars, cnt);
381 }
382
383 int
384 main(int argc, char **argv)
385 {
386 register int cnt, op, i;
387 bpf_u_int32 localnet, netmask;
388 register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName, *WFileNameAlt;
389 pcap_handler callback;
390 int type;
391 struct bpf_program fcode;
392 #ifndef WIN32
393 RETSIGTYPE (*oldhandler)(int);
394 #endif
395 struct print_info printinfo;
396 struct dump_info dumpinfo;
397 u_char *pcap_userdata;
398 char ebuf[PCAP_ERRBUF_SIZE];
399 char *username = NULL;
400 char *chroot_dir = NULL;
401 #ifdef HAVE_PCAP_FINDALLDEVS
402 pcap_if_t *devpointer;
403 int devnum;
404 #endif
405 int status;
406 #ifdef WIN32
407 u_int UserBufferSize = 1000000;
408 if(wsockinit() != 0) return 1;
409 #endif /* WIN32 */
410
411 cnt = -1;
412 device = NULL;
413 infile = NULL;
414 RFileName = NULL;
415 WFileName = NULL;
416 if ((cp = strrchr(argv[0], '/')) != NULL)
417 program_name = cp + 1;
418 else
419 program_name = argv[0];
420
421 if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
422 error("%s", ebuf);
423
424 #ifdef LIBSMI
425 smiInit("tcpdump");
426 #endif
427
428 opterr = 0;
429 while (
430 (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:YZ:")) != -1)
431 switch (op) {
432
433 case 'a':
434 /* compatibility for old -a */
435 break;
436
437 case 'A':
438 ++xflag;
439 ++Xflag;
440 ++Aflag;
441 break;
442
443 #ifdef WIN32
444 case 'B':
445 UserBufferSize = atoi(optarg)*1024;
446 if (UserBufferSize < 0)
447 error("invalid packet buffer size %s", optarg);
448 break;
449 #endif /* WIN32 */
450
451 case 'c':
452 cnt = atoi(optarg);
453 if (cnt <= 0)
454 error("invalid packet count %s", optarg);
455 break;
456
457 case 'C':
458 Cflag = atoi(optarg) * 1000000;
459 if (Cflag < 0)
460 error("invalid file size %s", optarg);
461 break;
462
463 case 'd':
464 ++dflag;
465 break;
466
467 #ifdef HAVE_PCAP_FINDALLDEVS
468 case 'D':
469 if (pcap_findalldevs(&devpointer, ebuf) < 0)
470 error("%s", ebuf);
471 else {
472 for (i = 0; devpointer != 0; i++) {
473 printf("%d.%s", i+1, devpointer->name);
474 if (devpointer->description != NULL)
475 printf(" (%s)", devpointer->description);
476 printf("\n");
477 devpointer = devpointer->next;
478 }
479 }
480 return 0;
481 #endif /* HAVE_PCAP_FINDALLDEVS */
482
483 case 'L':
484 Lflag++;
485 break;
486
487 case 'e':
488 ++eflag;
489 break;
490
491 case 'E':
492 #ifndef HAVE_LIBCRYPTO
493 warning("crypto code not compiled in");
494 #endif
495 espsecret = optarg;
496 break;
497
498 case 'f':
499 ++fflag;
500 break;
501
502 case 'F':
503 infile = optarg;
504 break;
505
506 case 'i':
507 if (optarg[0] == '0' && optarg[1] == 0)
508 error("Invalid adapter index");
509
510 #ifdef HAVE_PCAP_FINDALLDEVS
511 /*
512 * If the argument is a number, treat it as
513 * an index into the list of adapters, as
514 * printed by "tcpdump -D".
515 *
516 * This should be OK on UNIX systems, as interfaces
517 * shouldn't have names that begin with digits.
518 * It can be useful on Windows, where more than
519 * one interface can have the same name.
520 */
521 if ((devnum = atoi(optarg)) != 0) {
522 if (devnum < 0)
523 error("Invalid adapter index");
524
525 if (pcap_findalldevs(&devpointer, ebuf) < 0)
526 error("%s", ebuf);
527 else {
528 for (i = 0; i < devnum-1; i++){
529 devpointer = devpointer->next;
530 if (devpointer == NULL)
531 error("Invalid adapter index");
532 }
533 }
534 device = devpointer->name;
535 break;
536 }
537 #endif /* HAVE_PCAP_FINDALLDEVS */
538 device = optarg;
539 break;
540
541 case 'l':
542 #ifdef WIN32
543 /*
544 * _IOLBF is the same as _IOFBF in Microsoft's C
545 * libraries; the only alternative they offer
546 * is _IONBF.
547 *
548 * XXX - this should really be checking for MSVC++,
549 * not WIN32, if, for example, MinGW has its own
550 * C library that is more UNIX-compatible.
551 */
552 setvbuf(stdout, NULL, _IONBF, 0);
553 #else /* WIN32 */
554 #ifdef HAVE_SETLINEBUF
555 setlinebuf(stdout);
556 #else
557 setvbuf(stdout, NULL, _IOLBF, 0);
558 #endif
559 #endif /* WIN32 */
560 break;
561
562 case 'n':
563 ++nflag;
564 break;
565
566 case 'N':
567 ++Nflag;
568 break;
569
570 case 'm':
571 #ifdef LIBSMI
572 if (smiLoadModule(optarg) == 0) {
573 error("could not load MIB module %s", optarg);
574 }
575 sflag = 1;
576 #else
577 (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
578 program_name, optarg);
579 (void)fprintf(stderr, "(no libsmi support)\n");
580 #endif
581 break;
582
583 case 'O':
584 Oflag = 0;
585 break;
586
587 case 'p':
588 ++pflag;
589 break;
590
591 case 'q':
592 ++qflag;
593 break;
594
595 case 'r':
596 RFileName = optarg;
597 break;
598
599 case 'R':
600 Rflag = 0;
601 break;
602
603 case 's': {
604 char *end;
605
606 snaplen = strtol(optarg, &end, 0);
607 if (optarg == end || *end != '\0'
608 || snaplen < 0 || snaplen > 65535)
609 error("invalid snaplen %s", optarg);
610 else if (snaplen == 0)
611 snaplen = 65535;
612 break;
613 }
614
615 case 'S':
616 ++Sflag;
617 break;
618
619 case 't':
620 --tflag;
621 break;
622
623 case 'T':
624 if (strcasecmp(optarg, "vat") == 0)
625 packettype = PT_VAT;
626 else if (strcasecmp(optarg, "wb") == 0)
627 packettype = PT_WB;
628 else if (strcasecmp(optarg, "rpc") == 0)
629 packettype = PT_RPC;
630 else if (strcasecmp(optarg, "rtp") == 0)
631 packettype = PT_RTP;
632 else if (strcasecmp(optarg, "rtcp") == 0)
633 packettype = PT_RTCP;
634 else if (strcasecmp(optarg, "snmp") == 0)
635 packettype = PT_SNMP;
636 else if (strcasecmp(optarg, "cnfp") == 0)
637 packettype = PT_CNFP;
638 else if (strcasecmp(optarg, "tftp") == 0)
639 packettype = PT_TFTP;
640 else if (strcasecmp(optarg, "aodv") == 0)
641 packettype = PT_AODV;
642 else
643 error("unknown packet type `%s'", optarg);
644 break;
645
646 case 'u':
647 ++uflag;
648 break;
649
650 #ifdef HAVE_PCAP_DUMP_FLUSH
651 case 'U':
652 ++Uflag;
653 break;
654 #endif
655
656 case 'v':
657 ++vflag;
658 break;
659
660 case 'w':
661 WFileName = optarg;
662 break;
663
664 case 'W':
665 Wflag = atoi(optarg);
666 if (Wflag < 0)
667 error("invalid number of output files %s", optarg);
668 WflagChars = getWflagChars(Wflag);
669 break;
670
671 case 'x':
672 ++xflag;
673 break;
674
675 case 'X':
676 ++xflag;
677 ++Xflag;
678 break;
679
680 case 'y':
681 dlt_name = optarg;
682 dlt = pcap_datalink_name_to_val(dlt_name);
683 if (dlt < 0)
684 error("invalid data link type %s", dlt_name);
685 break;
686
687 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
688 case 'Y':
689 {
690 /* Undocumented flag */
691 #ifdef HAVE_PCAP_DEBUG
692 extern int pcap_debug;
693 pcap_debug = 1;
694 #else
695 extern int yydebug;
696 yydebug = 1;
697 #endif
698 }
699 break;
700 #endif
701 case 'Z':
702 if (optarg) {
703 username = strdup(optarg);
704 }
705 else {
706 usage();
707 /* NOTREACHED */
708 }
709 break;
710
711 default:
712 usage();
713 /* NOTREACHED */
714 }
715
716 if (tflag > 0)
717 thiszone = gmt2local(0);
718
719 #ifdef WITH_CHROOT
720 /* if run as root, prepare for chrooting */
721 if (getuid() == 0 || geteuid() == 0) {
722 /* future extensibility for cmd-line arguments */
723 if (!chroot_dir)
724 chroot_dir = WITH_CHROOT;
725 }
726 #endif
727
728 #ifdef WITH_USER
729 /* if run as root, prepare for dropping root privileges */
730 if (getuid() == 0 || geteuid() == 0) {
731 /* Run with '-Z root' to restore old behaviour */
732 if (!username)
733 username = WITH_USER;
734 }
735 #endif
736
737 if (RFileName != NULL) {
738 int dlt;
739 const char *dlt_name;
740
741 #ifndef WIN32
742 /*
743 * We don't need network access, so relinquish any set-UID
744 * or set-GID privileges we have (if any).
745 *
746 * We do *not* want set-UID privileges when opening a
747 * trace file, as that might let the user read other
748 * people's trace files (especially if we're set-UID
749 * root).
750 */
751 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
752 fprintf(stderr, "Warning: setgid/setuid failed !\n");
753 #endif /* WIN32 */
754 pd = pcap_open_offline(RFileName, ebuf);
755 if (pd == NULL)
756 error("%s", ebuf);
757 dlt = pcap_datalink(pd);
758 dlt_name = pcap_datalink_val_to_name(dlt);
759 if (dlt_name == NULL) {
760 fprintf(stderr, "reading from file %s, link-type %u\n",
761 RFileName, dlt);
762 } else {
763 fprintf(stderr,
764 "reading from file %s, link-type %s (%s)\n",
765 RFileName, dlt_name,
766 pcap_datalink_val_to_description(dlt));
767 }
768 localnet = 0;
769 netmask = 0;
770 if (fflag != 0)
771 error("-f and -r options are incompatible");
772 } else {
773 if (device == NULL) {
774 device = pcap_lookupdev(ebuf);
775 if (device == NULL)
776 error("%s", ebuf);
777 }
778 #ifdef WIN32
779 if(IsTextUnicode(device,
780 wcslen((short*)device), // Device always ends with a double \0, so this way to determine its
781 // length should be always valid
782 NULL))
783 {
784 fprintf(stderr, "%s: listening on %ws\n", program_name, device);
785 }
786 else
787 {
788 fprintf(stderr, "%s: listening on %s\n", program_name, device);
789 }
790
791 fflush(stderr);
792 #endif /* WIN32 */
793 *ebuf = '\0';
794 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
795 if (pd == NULL)
796 error("%s", ebuf);
797 else if (*ebuf)
798 warning("%s", ebuf);
799 /*
800 * Let user own process after socket has been opened.
801 */
802 #ifndef WIN32
803 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
804 fprintf(stderr, "Warning: setgid/setuid failed !\n");
805 #endif /* WIN32 */
806 #ifdef WIN32
807 if(UserBufferSize != 1000000)
808 if(pcap_setbuff(pd, UserBufferSize)==-1){
809 error("%s", pcap_geterr(pd));
810 }
811 #endif /* WIN32 */
812 if (Lflag)
813 show_dlts_and_exit(pd);
814 if (dlt >= 0) {
815 #ifdef HAVE_PCAP_SET_DATALINK
816 if (pcap_set_datalink(pd, dlt) < 0)
817 error("%s", pcap_geterr(pd));
818 #else
819 /*
820 * We don't actually support changing the
821 * data link type, so we only let them
822 * set it to what it already is.
823 */
824 if (dlt != pcap_datalink(pd)) {
825 error("%s is not one of the DLTs supported by this device\n",
826 dlt_name);
827 }
828 #endif
829 (void)fprintf(stderr, "%s: data link type %s\n",
830 program_name, dlt_name);
831 (void)fflush(stderr);
832 }
833 i = pcap_snapshot(pd);
834 if (snaplen < i) {
835 warning("snaplen raised from %d to %d", snaplen, i);
836 snaplen = i;
837 }
838 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
839 localnet = 0;
840 netmask = 0;
841 warning("%s", ebuf);
842 }
843 }
844 if (infile)
845 cmdbuf = read_infile(infile);
846 else
847 cmdbuf = copy_argv(&argv[optind]);
848
849 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
850 error("%s", pcap_geterr(pd));
851 if (dflag) {
852 bpf_dump(&fcode, dflag);
853 pcap_close(pd);
854 exit(0);
855 }
856 init_addrtoname(localnet, netmask);
857
858 #ifndef WIN32
859 (void)setsignal(SIGPIPE, cleanup);
860 #endif /* WIN32 */
861 (void)setsignal(SIGTERM, cleanup);
862 (void)setsignal(SIGINT, cleanup);
863 /* Cooperate with nohup(1) */
864 #ifndef WIN32
865 if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
866 (void)setsignal(SIGHUP, oldhandler);
867 #endif /* WIN32 */
868
869 if (pcap_setfilter(pd, &fcode) < 0)
870 error("%s", pcap_geterr(pd));
871 if (WFileName) {
872 pcap_dumper_t *p;
873
874 WFileNameAlt = (char *)malloc(strlen(WFileName) + MAX_CFLAG_CHARS + 1);
875 if (WFileNameAlt == NULL)
876 error("malloc of WFileNameAlt");
877 MakeFilename(WFileNameAlt, WFileName, 0, WflagChars);
878 p = pcap_dump_open(pd, WFileNameAlt);
879 if (p == NULL)
880 error("%s", pcap_geterr(pd));
881 if (Cflag != 0) {
882 callback = dump_packet_and_trunc;
883 dumpinfo.WFileName = WFileName;
884 dumpinfo.pd = pd;
885 dumpinfo.p = p;
886 pcap_userdata = (u_char *)&dumpinfo;
887 } else {
888 callback = dump_packet;
889 pcap_userdata = (u_char *)p;
890 }
891 } else {
892 type = pcap_datalink(pd);
893 printinfo.printer = lookup_printer(type);
894 if (printinfo.printer == NULL) {
895 dlt_name = pcap_datalink_val_to_name(type);
896 if (dlt_name != NULL)
897 error("unsupported data link type %s", dlt_name);
898 else
899 error("unsupported data link type %d", type);
900 }
901 callback = print_packet;
902 pcap_userdata = (u_char *)&printinfo;
903 }
904 #ifndef WIN32
905 /*
906 * We cannot do this earlier, because we want to be able to open
907 * the file (if done) for writing before giving up permissions.
908 */
909 if (getuid() == 0 || geteuid() == 0) {
910 if (username || chroot_dir)
911 droproot(username, chroot_dir);
912 }
913 #endif /* WIN32 */
914 #ifdef SIGINFO
915 (void)setsignal(SIGINFO, requestinfo);
916 #endif
917
918 if (vflag > 0 && WFileName) {
919 /*
920 * When capturing to a file, "-v" means tcpdump should,
921 * every 10 secodns, "v"erbosely report the number of
922 * packets captured.
923 */
924 #ifdef USE_WIN32_MM_TIMER
925 /* call verbose_stats_dump() each 1000 +/-100msec */
926 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
927 setvbuf(stderr, NULL, _IONBF, 0);
928 #elif defined(HAVE_ALARM)
929 (void)setsignal(SIGALRM, verbose_stats_dump);
930 alarm(1);
931 #endif
932 }
933
934 #ifndef WIN32
935 if (RFileName == NULL) {
936 int dlt;
937 const char *dlt_name;
938
939 if (!vflag && !WFileName) {
940 (void)fprintf(stderr,
941 "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
942 program_name);
943 } else
944 (void)fprintf(stderr, "%s: ", program_name);
945 dlt = pcap_datalink(pd);
946 dlt_name = pcap_datalink_val_to_name(dlt);
947 if (dlt_name == NULL) {
948 (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
949 device, dlt, snaplen);
950 } else {
951 (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
952 device, dlt_name,
953 pcap_datalink_val_to_description(dlt), snaplen);
954 }
955 (void)fflush(stderr);
956 }
957 #endif /* WIN32 */
958 status = pcap_loop(pd, cnt, callback, pcap_userdata);
959 if (WFileName == NULL) {
960 /*
961 * We're printing packets. Flush the printed output,
962 * so it doesn't get intermingled with error output.
963 */
964 if (status == -2) {
965 /*
966 * We got interrupted, so perhaps we didn't
967 * manage to finish a line we were printing.
968 * Print an extra newline, just in case.
969 */
970 putchar('\n');
971 }
972 (void)fflush(stdout);
973 }
974 if (status == -1) {
975 /*
976 * Error. Report it.
977 */
978 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
979 program_name, pcap_geterr(pd));
980 }
981 if (RFileName == NULL) {
982 /*
983 * We're doing a live capture. Report the capture
984 * statistics.
985 */
986 info(1);
987 }
988 pcap_close(pd);
989 exit(status == -1 ? 1 : 0);
990 }
991
992 /* make a clean exit on interrupts */
993 static RETSIGTYPE
994 cleanup(int signo _U_)
995 {
996 #ifdef USE_WIN32_MM_TIMER
997 if (timer_id)
998 timeKillEvent(timer_id);
999 timer_id = 0;
1000 #elif defined(HAVE_ALARM)
1001 alarm(0);
1002 #endif
1003
1004 #ifdef HAVE_PCAP_BREAKLOOP
1005 /*
1006 * We have "pcap_breakloop()"; use it, so that we do as little
1007 * as possible in the signal handler (it's probably not safe
1008 * to do anything with standard I/O streams in a signal handler -
1009 * the ANSI C standard doesn't say it is).
1010 */
1011 pcap_breakloop(pd);
1012 #else
1013 /*
1014 * We don't have "pcap_breakloop()"; this isn't safe, but
1015 * it's the best we can do. Print the summary if we're
1016 * not reading from a savefile - i.e., if we're doing a
1017 * live capture - and exit.
1018 */
1019 if (pd != NULL && pcap_file(pd) == NULL) {
1020 /*
1021 * We got interrupted, so perhaps we didn't
1022 * manage to finish a line we were printing.
1023 * Print an extra newline, just in case.
1024 */
1025 putchar('\n');
1026 (void)fflush(stdout);
1027 info(1);
1028 }
1029 exit(0);
1030 #endif
1031 }
1032
1033 static void
1034 info(register int verbose)
1035 {
1036 struct pcap_stat stat;
1037
1038 if (pcap_stats(pd, &stat) < 0) {
1039 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1040 return;
1041 }
1042
1043 if (!verbose)
1044 fprintf(stderr, "%s: ", program_name);
1045
1046 (void)fprintf(stderr, "%u packets captured", packets_captured);
1047 if (!verbose)
1048 fputs(", ", stderr);
1049 else
1050 putc('\n', stderr);
1051 (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
1052 if (!verbose)
1053 fputs(", ", stderr);
1054 else
1055 putc('\n', stderr);
1056 (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
1057 infoprint = 0;
1058 }
1059
1060 static void
1061 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1062 {
1063 struct dump_info *dump_info;
1064 char *name;
1065
1066 ++packets_captured;
1067
1068 ++infodelay;
1069
1070 dump_info = (struct dump_info *)user;
1071
1072 /*
1073 * XXX - this won't prevent capture files from getting
1074 * larger than Cflag - the last packet written to the
1075 * file could put it over Cflag.
1076 */
1077 if (ftell((FILE *)dump_info->p) > Cflag) {
1078 /*
1079 * Close the current file and open a new one.
1080 */
1081 pcap_dump_close(dump_info->p);
1082 Cflag_count++;
1083 if (Wflag > 0) {
1084 if (Cflag_count >= Wflag)
1085 Cflag_count = 0;
1086 } else {
1087 if (Cflag_count >= MAX_CFLAG)
1088 error("too many output files");
1089 }
1090 name = (char *)malloc(strlen(dump_info->WFileName) + MAX_CFLAG_CHARS + 1);
1091 if (name == NULL)
1092 error("dump_packet_and_trunc: malloc");
1093 MakeFilename(name, dump_info->WFileName, Cflag_count, WflagChars);
1094 dump_info->p = pcap_dump_open(dump_info->pd, name);
1095 free(name);
1096 if (dump_info->p == NULL)
1097 error("%s", pcap_geterr(pd));
1098 }
1099
1100 pcap_dump((u_char *)dump_info->p, h, sp);
1101 #ifdef HAVE_PCAP_DUMP_FLUSH
1102 if (Uflag)
1103 pcap_dump_flush(dump_info->p);
1104 #endif
1105
1106 --infodelay;
1107 if (infoprint)
1108 info(0);
1109 }
1110
1111 static void
1112 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1113 {
1114 ++packets_captured;
1115
1116 ++infodelay;
1117
1118 pcap_dump(user, h, sp);
1119 #ifdef HAVE_PCAP_DUMP_FLUSH
1120 if (Uflag)
1121 pcap_dump_flush((pcap_dumper_t *)user);
1122 #endif
1123
1124 --infodelay;
1125 if (infoprint)
1126 info(0);
1127 }
1128
1129 static void
1130 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1131 {
1132 struct print_info *print_info;
1133 u_int hdrlen;
1134
1135 ++packets_captured;
1136
1137 ++infodelay;
1138 ts_print(&h->ts);
1139
1140 print_info = (struct print_info *)user;
1141
1142 /*
1143 * Some printers want to check that they're not walking off the
1144 * end of the packet.
1145 * Rather than pass it all the way down, we set this global.
1146 */
1147 snapend = sp + h->caplen;
1148
1149 hdrlen = (*print_info->printer)(h, sp);
1150 if (xflag) {
1151 /*
1152 * Print the raw packet data.
1153 */
1154 if (xflag > 1) {
1155 /*
1156 * Include the link-layer header.
1157 */
1158 default_print(sp, h->caplen);
1159 } else {
1160 /*
1161 * Don't include the link-layer header - and if
1162 * we have nothing past the link-layer header,
1163 * print nothing.
1164 */
1165 if (h->caplen > hdrlen)
1166 default_print(sp + hdrlen,
1167 h->caplen - hdrlen);
1168 }
1169 }
1170
1171 putchar('\n');
1172
1173 --infodelay;
1174 if (infoprint)
1175 info(0);
1176 }
1177
1178 #ifdef WIN32
1179 /*
1180 * XXX - there should really be libpcap calls to get the version
1181 * number as a string (the string would be generated from #defines
1182 * at run time, so that it's not generated from string constants
1183 * in the library, as, on many UNIX systems, those constants would
1184 * be statically linked into the application executable image, and
1185 * would thus reflect the version of libpcap on the system on
1186 * which the application was *linked*, not the system on which it's
1187 * *running*.
1188 *
1189 * That routine should be documented, unlike the "version[]"
1190 * string, so that UNIX vendors providing their own libpcaps
1191 * don't omit it (as a couple of vendors have...).
1192 *
1193 * Packet.dll should perhaps also export a routine to return the
1194 * version number of the Packet.dll code, to supply the
1195 * "Wpcap_version" information on Windows.
1196 */
1197 char WDversion[]="current-cvs.tcpdump.org";
1198 #if !defined(HAVE_GENERATED_VERSION)
1199 char version[]="current-cvs.tcpdump.org";
1200 #endif
1201 char pcap_version[]="current-cvs.tcpdump.org";
1202 char Wpcap_version[]="3.0 alpha";
1203 #endif
1204
1205 /*
1206 * By default, print the specified data out in hex.
1207 */
1208 void
1209 default_print(register const u_char *bp, register u_int length)
1210 {
1211 ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1212 }
1213
1214 #ifdef SIGINFO
1215 RETSIGTYPE requestinfo(int signo _U_)
1216 {
1217 if (infodelay)
1218 ++infoprint;
1219 else
1220 info(0);
1221 }
1222 #endif
1223
1224 /*
1225 * Called once each second in verbose mode while dumping to file
1226 */
1227 #ifdef USE_WIN32_MM_TIMER
1228 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
1229 DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
1230 {
1231 struct pcap_stat stat;
1232
1233 if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1234 fprintf(stderr, "Got %u\r", packets_captured);
1235 }
1236 #elif defined(HAVE_ALARM)
1237 static void verbose_stats_dump(int sig _U_)
1238 {
1239 struct pcap_stat stat;
1240
1241 if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1242 fprintf(stderr, "Got %u\r", packets_captured);
1243 alarm(1);
1244 }
1245 #endif
1246
1247 static void
1248 usage(void)
1249 {
1250 extern char version[];
1251 #ifndef HAVE_PCAP_LIB_VERSION
1252 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1253 extern char pcap_version[];
1254 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1255 static char pcap_version[] = "unknown";
1256 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1257 #endif /* HAVE_PCAP_LIB_VERSION */
1258
1259 #ifdef HAVE_PCAP_LIB_VERSION
1260 (void)fprintf(stderr, "%s version %s\n", program_name, version);
1261 (void)fprintf(stderr, "%s\n", pcap_lib_version());
1262 #else /* HAVE_PCAP_LIB_VERSION */
1263 #ifdef WIN32
1264 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1265 (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1266 #else /* WIN32 */
1267 (void)fprintf(stderr, "%s version %s\n", program_name, version);
1268 (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1269 #endif /* WIN32 */
1270 #endif /* HAVE_PCAP_LIB_VERSION */
1271 (void)fprintf(stderr,
1272 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
1273 (void)fprintf(stderr,
1274 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
1275 (void)fprintf(stderr,
1276 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ]\n");
1277 (void)fprintf(stderr,
1278 "\t\t[ -y datalinktype ] [ -Z user ]\n");
1279 (void)fprintf(stderr,
1280 "\t\t[ expression ]\n");
1281 exit(1);
1282 }
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