]> The Tcpdump Group git mirrors - tcpdump/blob - tcpdump.c
projects / tcpdump / blob
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
check against min. TLV length / get if logic right
[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 1.216.2.13 2004-09-04 00:04:49 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 #include <pcap.h>
60 #include <signal.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64
65 #include "interface.h"
66 #include "addrtoname.h"
67 #include "machdep.h"
68 #include "setsignal.h"
69 #include "gmt2local.h"
70 #include "pcap-missing.h"
71
72 int dflag; /* print filter code */
73 int eflag; /* print ethernet header */
74 int fflag; /* don't translate "foreign" IP address */
75 int Lflag; /* list available data link types and exit */
76 int nflag; /* leave addresses as numbers */
77 int Nflag; /* remove domains from printed host names */
78 int Oflag = 1; /* run filter code optimizer */
79 int pflag; /* don't go promiscuous */
80 int qflag; /* quick (shorter) output */
81 int Rflag = 1; /* print sequence # field in AH/ESP*/
82 int sflag = 0; /* use the libsmi to translate OIDs */
83 int Sflag; /* print raw TCP sequence numbers */
84 int tflag = 1; /* print packet arrival time */
85 int Uflag = 0; /* "unbuffered" output of dump files */
86 int uflag = 0; /* Print undecoded NFS handles */
87 int vflag; /* verbose */
88 int xflag; /* print packet in hex */
89 int Xflag; /* print packet in ascii as well as hex */
90 off_t Cflag = 0; /* rotate dump files after this many bytes */
91 int Aflag = 0; /* print packet only in ascii observing LF, CR, TAB, SPACE */
92 int dlt = -1; /* if != -1, ask libpcap for the DLT it names */
93
94 const char *dlt_name = NULL;
95
96 char *espsecret = NULL; /* ESP secret key */
97
98 int packettype;
99
100 static int infodelay;
101 static int infoprint;
102
103 char *program_name;
104
105 int32_t thiszone; /* seconds offset from gmt to local time */
106
107 /* Forwards */
108 static RETSIGTYPE cleanup(int);
109 static void usage(void) __attribute__((noreturn));
110 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
111
112 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
113 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
114 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
115
116 #ifdef SIGINFO
117 RETSIGTYPE requestinfo(int);
118 #endif
119
120 static void info(int);
121 static u_int packets_captured;
122
123 /* Length of saved portion of packet. */
124 int snaplen = DEFAULT_SNAPLEN;
125
126 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
127
128 struct printer {
129 if_printer f;
130 int type;
131 };
132
133 static struct printer printers[] = {
134 { arcnet_if_print, DLT_ARCNET },
135 #ifdef DLT_ARCNET_LINUX
136 { arcnet_linux_if_print, DLT_ARCNET_LINUX },
137 #endif
138 { ether_if_print, DLT_EN10MB },
139 { token_if_print, DLT_IEEE802 },
140 #ifdef DLT_LANE8023
141 { lane_if_print, DLT_LANE8023 },
142 #endif
143 #ifdef DLT_CIP
144 { cip_if_print, DLT_CIP },
145 #endif
146 #ifdef DLT_ATM_CLIP
147 { cip_if_print, DLT_ATM_CLIP },
148 #endif
149 { sl_if_print, DLT_SLIP },
150 #ifdef DLT_SLIP_BSDOS
151 { sl_bsdos_if_print, DLT_SLIP_BSDOS },
152 #endif
153 { ppp_if_print, DLT_PPP },
154 #ifdef DLT_PPP_BSDOS
155 { ppp_bsdos_if_print, DLT_PPP_BSDOS },
156 #endif
157 { fddi_if_print, DLT_FDDI },
158 { null_if_print, DLT_NULL },
159 #ifdef DLT_LOOP
160 { null_if_print, DLT_LOOP },
161 #endif
162 { raw_if_print, DLT_RAW },
163 { atm_if_print, DLT_ATM_RFC1483 },
164 #ifdef DLT_C_HDLC
165 { chdlc_if_print, DLT_C_HDLC },
166 #endif
167 #ifdef DLT_HDLC
168 { chdlc_if_print, DLT_HDLC },
169 #endif
170 #ifdef DLT_PPP_SERIAL
171 { ppp_hdlc_if_print, DLT_PPP_SERIAL },
172 #endif
173 #ifdef DLT_PPP_ETHER
174 { pppoe_if_print, DLT_PPP_ETHER },
175 #endif
176 #ifdef DLT_LINUX_SLL
177 { sll_if_print, DLT_LINUX_SLL },
178 #endif
179 #ifdef DLT_IEEE802_11
180 { ieee802_11_if_print, DLT_IEEE802_11},
181 #endif
182 #ifdef DLT_LTALK
183 { ltalk_if_print, DLT_LTALK },
184 #endif
185 #ifdef DLT_PFLOG
186 { pflog_if_print, DLT_PFLOG },
187 #endif
188 #ifdef DLT_FR
189 { fr_if_print, DLT_FR },
190 #endif
191 #ifdef DLT_FRELAY
192 { fr_if_print, DLT_FRELAY },
193 #endif
194 #ifdef DLT_SUNATM
195 { sunatm_if_print, DLT_SUNATM },
196 #endif
197 #ifdef DLT_IP_OVER_FC
198 { ipfc_if_print, DLT_IP_OVER_FC },
199 #endif
200 #ifdef DLT_PRISM_HEADER
201 { prism_if_print, DLT_PRISM_HEADER },
202 #endif
203 #ifdef DLT_IEEE802_11_RADIO
204 { ieee802_11_radio_if_print, DLT_IEEE802_11_RADIO },
205 #endif
206 #ifdef DLT_ENC
207 { enc_if_print, DLT_ENC },
208 #endif
209 #ifdef DLT_APPLE_IP_OVER_IEEE1394
210 { ap1394_if_print, DLT_APPLE_IP_OVER_IEEE1394 },
211 #endif
212 { NULL, 0 },
213 };
214
215 static if_printer
216 lookup_printer(int type)
217 {
218 struct printer *p;
219
220 for (p = printers; p->f; ++p)
221 if (type == p->type)
222 return p->f;
223
224 return NULL;
225 /* NOTREACHED */
226 }
227
228 static pcap_t *pd;
229
230 extern int optind;
231 extern int opterr;
232 extern char *optarg;
233
234 struct print_info {
235 if_printer printer;
236 };
237
238 struct dump_info {
239 char *WFileName;
240 pcap_t *pd;
241 pcap_dumper_t *p;
242 };
243
244 static void
245 show_dlts_and_exit(pcap_t *pd)
246 {
247 int n_dlts;
248 int *dlts = 0;
249 const char *dlt_name;
250
251 n_dlts = pcap_list_datalinks(pd, &dlts);
252 if (n_dlts < 0)
253 error("%s", pcap_geterr(pd));
254 else if (n_dlts == 0 || !dlts)
255 error("No data link types.");
256
257 (void) fprintf(stderr, "Data link types (use option -y to set):\n");
258
259 while (--n_dlts >= 0) {
260 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
261 if (dlt_name != NULL) {
262 (void) fprintf(stderr, " %s (%s)", dlt_name,
263 pcap_datalink_val_to_description(dlts[n_dlts]));
264
265 /*
266 * OK, does tcpdump handle that type?
267 */
268 if (lookup_printer(dlts[n_dlts]) == NULL)
269 (void) fprintf(stderr, " (not supported)");
270 putchar('\n');
271 } else {
272 (void) fprintf(stderr, " DLT %d (not supported)\n",
273 dlts[n_dlts]);
274 }
275 }
276 free(dlts);
277 exit(0);
278 }
279
280 /*
281 * Set up flags that might or might not be supported depending on the
282 * version of libpcap we're using.
283 */
284 #ifdef WIN32
285 #define B_FLAG "B:"
286 #define B_FLAG_USAGE " [ -B size ]"
287 #else /* WIN32 */
288 #define B_FLAG
289 #define B_FLAG_USAGE
290 #endif /* WIN32 */
291
292 #ifdef HAVE_PCAP_FINDALLDEVS
293 #define D_FLAG "D"
294 #else
295 #define D_FLAG
296 #endif
297
298 #ifdef HAVE_PCAP_DUMP_FLUSH
299 #define U_FLAG "U"
300 #else
301 #define U_FLAG
302 #endif
303
304 int
305 main(int argc, char **argv)
306 {
307 register int cnt, op, i;
308 bpf_u_int32 localnet, netmask;
309 register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
310 pcap_handler callback;
311 int type;
312 struct bpf_program fcode;
313 #ifndef WIN32
314 RETSIGTYPE (*oldhandler)(int);
315 #endif
316 struct print_info printinfo;
317 struct dump_info dumpinfo;
318 u_char *pcap_userdata;
319 char ebuf[PCAP_ERRBUF_SIZE];
320 #ifdef HAVE_PCAP_FINDALLDEVS
321 pcap_if_t *devpointer;
322 int devnum;
323 #endif
324 int status;
325 #ifdef WIN32
326 u_int UserBufferSize = 1000000;
327 if(wsockinit() != 0) return 1;
328 #endif /* WIN32 */
329
330 cnt = -1;
331 device = NULL;
332 infile = NULL;
333 RFileName = NULL;
334 WFileName = NULL;
335 if ((cp = strrchr(argv[0], '/')) != NULL)
336 program_name = cp + 1;
337 else
338 program_name = argv[0];
339
340 if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
341 error("%s", ebuf);
342
343 #ifdef LIBSMI
344 smiInit("tcpdump");
345 #endif
346
347 opterr = 0;
348 while (
349 (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:nNOpqr:Rs:StT:u" U_FLAG "vw:xXy:Y")) != -1)
350 switch (op) {
351
352 case 'a':
353 /* compatibility for old -a */
354 break;
355
356 case 'A':
357 ++xflag;
358 ++Xflag;
359 ++Aflag;
360 break;
361
362 #ifdef WIN32
363 case 'B':
364 UserBufferSize = atoi(optarg)*1024;
365 if (UserBufferSize < 0)
366 error("invalid packet buffer size %s", optarg);
367 break;
368 #endif /* WIN32 */
369
370 case 'c':
371 cnt = atoi(optarg);
372 if (cnt <= 0)
373 error("invalid packet count %s", optarg);
374 break;
375
376 case 'C':
377 Cflag = atoi(optarg) * 1000000;
378 if (Cflag < 0)
379 error("invalid file size %s", optarg);
380 break;
381
382 case 'd':
383 ++dflag;
384 break;
385
386 #ifdef HAVE_PCAP_FINDALLDEVS
387 case 'D':
388 if (pcap_findalldevs(&devpointer, ebuf) < 0)
389 error("%s", ebuf);
390 else {
391 for (i = 0; devpointer != 0; i++) {
392 printf("%d.%s", i+1, devpointer->name);
393 if (devpointer->description != NULL)
394 printf(" (%s)", devpointer->description);
395 printf("\n");
396 devpointer = devpointer->next;
397 }
398 }
399 return 0;
400 #endif /* HAVE_PCAP_FINDALLDEVS */
401
402 case 'L':
403 Lflag++;
404 break;
405
406 case 'e':
407 ++eflag;
408 break;
409
410 case 'E':
411 #ifndef HAVE_LIBCRYPTO
412 warning("crypto code not compiled in");
413 #endif
414 espsecret = optarg;
415 break;
416
417 case 'f':
418 ++fflag;
419 break;
420
421 case 'F':
422 infile = optarg;
423 break;
424
425 case 'i':
426 if (optarg[0] == '0' && optarg[1] == 0)
427 error("Invalid adapter index");
428
429 #ifdef HAVE_PCAP_FINDALLDEVS
430 /*
431 * If the argument is a number, treat it as
432 * an index into the list of adapters, as
433 * printed by "tcpdump -D".
434 *
435 * This should be OK on UNIX systems, as interfaces
436 * shouldn't have names that begin with digits.
437 * It can be useful on Windows, where more than
438 * one interface can have the same name.
439 */
440 if ((devnum = atoi(optarg)) != 0) {
441 if (devnum < 0)
442 error("Invalid adapter index");
443
444 if (pcap_findalldevs(&devpointer, ebuf) < 0)
445 error("%s", ebuf);
446 else {
447 for (i = 0; i < devnum-1; i++){
448 devpointer = devpointer->next;
449 if (devpointer == NULL)
450 error("Invalid adapter index");
451 }
452 }
453 device = devpointer->name;
454 break;
455 }
456 #endif /* HAVE_PCAP_FINDALLDEVS */
457 device = optarg;
458 break;
459
460 case 'l':
461 #ifdef WIN32
462 /*
463 * _IOLBF is the same as _IOFBF in Microsoft's C
464 * libraries; the only alternative they offer
465 * is _IONBF.
466 *
467 * XXX - this should really be checking for MSVC++,
468 * not WIN32, if, for example, MinGW has its own
469 * C library that is more UNIX-compatible.
470 */
471 setvbuf(stdout, NULL, _IONBF, 0);
472 #else /* WIN32 */
473 #ifdef HAVE_SETLINEBUF
474 setlinebuf(stdout);
475 #else
476 setvbuf(stdout, NULL, _IOLBF, 0);
477 #endif
478 #endif /* WIN32 */
479 break;
480
481 case 'n':
482 ++nflag;
483 break;
484
485 case 'N':
486 ++Nflag;
487 break;
488
489 case 'm':
490 #ifdef LIBSMI
491 if (smiLoadModule(optarg) == 0) {
492 error("could not load MIB module %s", optarg);
493 }
494 sflag = 1;
495 #else
496 (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
497 program_name, optarg);
498 (void)fprintf(stderr, "(no libsmi support)\n");
499 #endif
500 break;
501
502 case 'O':
503 Oflag = 0;
504 break;
505
506 case 'p':
507 ++pflag;
508 break;
509
510 case 'q':
511 ++qflag;
512 break;
513
514 case 'r':
515 RFileName = optarg;
516 break;
517
518 case 'R':
519 Rflag = 0;
520 break;
521
522 case 's': {
523 char *end;
524
525 snaplen = strtol(optarg, &end, 0);
526 if (optarg == end || *end != '\0'
527 || snaplen < 0 || snaplen > 65535)
528 error("invalid snaplen %s", optarg);
529 else if (snaplen == 0)
530 snaplen = 65535;
531 break;
532 }
533
534 case 'S':
535 ++Sflag;
536 break;
537
538 case 't':
539 --tflag;
540 break;
541
542 case 'T':
543 if (strcasecmp(optarg, "vat") == 0)
544 packettype = PT_VAT;
545 else if (strcasecmp(optarg, "wb") == 0)
546 packettype = PT_WB;
547 else if (strcasecmp(optarg, "rpc") == 0)
548 packettype = PT_RPC;
549 else if (strcasecmp(optarg, "rtp") == 0)
550 packettype = PT_RTP;
551 else if (strcasecmp(optarg, "rtcp") == 0)
552 packettype = PT_RTCP;
553 else if (strcasecmp(optarg, "snmp") == 0)
554 packettype = PT_SNMP;
555 else if (strcasecmp(optarg, "cnfp") == 0)
556 packettype = PT_CNFP;
557 else if (strcasecmp(optarg, "tftp") == 0)
558 packettype = PT_TFTP;
559 else if (strcasecmp(optarg, "aodv") == 0)
560 packettype = PT_AODV;
561 else
562 error("unknown packet type `%s'", optarg);
563 break;
564
565 case 'u':
566 ++uflag;
567 break;
568
569 #ifdef HAVE_PCAP_DUMP_FLUSH
570 case 'U':
571 ++Uflag;
572 break;
573 #endif
574
575 case 'v':
576 ++vflag;
577 break;
578
579 case 'w':
580 WFileName = optarg;
581 break;
582
583 case 'x':
584 ++xflag;
585 break;
586
587 case 'X':
588 ++Xflag;
589 break;
590
591 case 'y':
592 dlt_name = optarg;
593 dlt = pcap_datalink_name_to_val(dlt_name);
594 if (dlt < 0)
595 error("invalid data link type %s", dlt_name);
596 break;
597
598 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
599 case 'Y':
600 {
601 /* Undocumented flag */
602 #ifdef HAVE_PCAP_DEBUG
603 extern int pcap_debug;
604 pcap_debug = 1;
605 #else
606 extern int yydebug;
607 yydebug = 1;
608 #endif
609 }
610 break;
611 #endif
612 default:
613 usage();
614 /* NOTREACHED */
615 }
616
617 if (tflag > 0 || tflag == -3)
618 thiszone = gmt2local(0);
619
620 if (RFileName != NULL) {
621 int dlt;
622 const char *dlt_name;
623
624 #ifndef WIN32
625 /*
626 * We don't need network access, so relinquish any set-UID
627 * or set-GID privileges we have (if any).
628 *
629 * We do *not* want set-UID privileges when opening a
630 * trace file, as that might let the user read other
631 * people's trace files (especially if we're set-UID
632 * root).
633 */
634 setuid(getuid());
635 #endif /* WIN32 */
636 pd = pcap_open_offline(RFileName, ebuf);
637 if (pd == NULL)
638 error("%s", ebuf);
639 dlt = pcap_datalink(pd);
640 dlt_name = pcap_datalink_val_to_name(dlt);
641 if (dlt_name == NULL) {
642 fprintf(stderr, "reading from file %s, link-type %u\n",
643 RFileName, dlt);
644 } else {
645 fprintf(stderr,
646 "reading from file %s, link-type %s (%s)\n",
647 RFileName, dlt_name,
648 pcap_datalink_val_to_description(dlt));
649 }
650 localnet = 0;
651 netmask = 0;
652 if (fflag != 0)
653 error("-f and -r options are incompatible");
654 } else {
655 if (device == NULL) {
656 device = pcap_lookupdev(ebuf);
657 if (device == NULL)
658 error("%s", ebuf);
659 }
660 #ifdef WIN32
661 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
662 { //a Unicode string has a \0 as second byte (so strlen() is 1)
663 fprintf(stderr, "%s: listening on %ws\n", program_name, device);
664 }
665 else
666 {
667 fprintf(stderr, "%s: listening on %s\n", program_name, device);
668 }
669
670 fflush(stderr);
671 #endif /* WIN32 */
672 *ebuf = '\0';
673 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
674 if (pd == NULL)
675 error("%s", ebuf);
676 else if (*ebuf)
677 warning("%s", ebuf);
678 #ifdef WIN32
679 if(UserBufferSize != 1000000)
680 if(pcap_setbuff(pd, UserBufferSize)==-1){
681 error("%s", pcap_geterr(pd));
682 }
683 #endif /* WIN32 */
684 if (Lflag)
685 show_dlts_and_exit(pd);
686 if (dlt >= 0) {
687 #ifdef HAVE_PCAP_SET_DATALINK
688 if (pcap_set_datalink(pd, dlt) < 0)
689 error("%s", pcap_geterr(pd));
690 #else
691 /*
692 * We don't actually support changing the
693 * data link type, so we only let them
694 * set it to what it already is.
695 */
696 if (dlt != pcap_datalink(pd)) {
697 error("%s is not one of the DLTs supported by this device\n",
698 dlt_name);
699 }
700 #endif
701 (void)fprintf(stderr, "%s: data link type %s\n",
702 program_name, dlt_name);
703 (void)fflush(stderr);
704 }
705 i = pcap_snapshot(pd);
706 if (snaplen < i) {
707 warning("snaplen raised from %d to %d", snaplen, i);
708 snaplen = i;
709 }
710 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
711 localnet = 0;
712 netmask = 0;
713 warning("%s", ebuf);
714 }
715 /*
716 * Let user own process after socket has been opened.
717 */
718 #ifndef WIN32
719 setuid(getuid());
720 #endif /* WIN32 */
721 }
722 if (infile)
723 cmdbuf = read_infile(infile);
724 else
725 cmdbuf = copy_argv(&argv[optind]);
726
727 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
728 error("%s", pcap_geterr(pd));
729 if (dflag) {
730 bpf_dump(&fcode, dflag);
731 pcap_close(pd);
732 exit(0);
733 }
734 init_addrtoname(localnet, netmask);
735
736 #ifndef WIN32
737 (void)setsignal(SIGPIPE, cleanup);
738 #endif /* WIN32 */
739 (void)setsignal(SIGTERM, cleanup);
740 (void)setsignal(SIGINT, cleanup);
741 /* Cooperate with nohup(1) */
742 #ifndef WIN32
743 if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
744 (void)setsignal(SIGHUP, oldhandler);
745 #endif /* WIN32 */
746
747 if (pcap_setfilter(pd, &fcode) < 0)
748 error("%s", pcap_geterr(pd));
749 if (WFileName) {
750 pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
751 if (p == NULL)
752 error("%s", pcap_geterr(pd));
753 if (Cflag != 0) {
754 callback = dump_packet_and_trunc;
755 dumpinfo.WFileName = WFileName;
756 dumpinfo.pd = pd;
757 dumpinfo.p = p;
758 pcap_userdata = (u_char *)&dumpinfo;
759 } else {
760 callback = dump_packet;
761 pcap_userdata = (u_char *)p;
762 }
763 } else {
764 type = pcap_datalink(pd);
765 printinfo.printer = lookup_printer(type);
766 if (printinfo.printer == NULL) {
767 dlt_name = pcap_datalink_val_to_name(type);
768 if (dlt_name != NULL)
769 error("unsupported data link type %s", dlt_name);
770 else
771 error("unsupported data link type %d", type);
772 }
773 callback = print_packet;
774 pcap_userdata = (u_char *)&printinfo;
775 }
776 #ifdef SIGINFO
777 (void)setsignal(SIGINFO, requestinfo);
778 #endif
779 #ifndef WIN32
780 if (RFileName == NULL) {
781 int dlt;
782 const char *dlt_name;
783
784 if (!vflag && !WFileName) {
785 (void)fprintf(stderr,
786 "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
787 program_name);
788 } else
789 (void)fprintf(stderr, "%s: ", program_name);
790 dlt = pcap_datalink(pd);
791 dlt_name = pcap_datalink_val_to_name(dlt);
792 if (dlt_name == NULL) {
793 (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
794 device, dlt, snaplen);
795 } else {
796 (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
797 device, dlt_name,
798 pcap_datalink_val_to_description(dlt), snaplen);
799 }
800 (void)fflush(stderr);
801 }
802 #endif /* WIN32 */
803 status = pcap_loop(pd, cnt, callback, pcap_userdata);
804 if (WFileName == NULL) {
805 /*
806 * We're printing packets. Flush the printed output,
807 * so it doesn't get intermingled with error output.
808 */
809 if (status == -2) {
810 /*
811 * We got interrupted, so perhaps we didn't
812 * manage to finish a line we were printing.
813 * Print an extra newline, just in case.
814 */
815 putchar('\n');
816 }
817 (void)fflush(stdout);
818 }
819 if (status == -1) {
820 /*
821 * Error. Report it.
822 */
823 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
824 program_name, pcap_geterr(pd));
825 }
826 if (RFileName == NULL) {
827 /*
828 * We're doing a live capture. Report the capture
829 * statistics.
830 */
831 info(1);
832 }
833 pcap_close(pd);
834 exit(status == -1 ? 1 : 0);
835 }
836
837 /* make a clean exit on interrupts */
838 static RETSIGTYPE
839 cleanup(int signo _U_)
840 {
841 #ifdef HAVE_PCAP_BREAKLOOP
842 /*
843 * We have "pcap_breakloop()"; use it, so that we do as little
844 * as possible in the signal handler (it's probably not safe
845 * to do anything with standard I/O streams in a signal handler -
846 * the ANSI C standard doesn't say it is).
847 */
848 pcap_breakloop(pd);
849 #else
850 /*
851 * We don't have "pcap_breakloop()"; this isn't safe, but
852 * it's the best we can do. Print the summary if we're
853 * not reading from a savefile - i.e., if we're doing a
854 * live capture - and exit.
855 */
856 if (pd != NULL && pcap_file(pd) == NULL) {
857 /*
858 * We got interrupted, so perhaps we didn't
859 * manage to finish a line we were printing.
860 * Print an extra newline, just in case.
861 */
862 putchar('\n');
863 (void)fflush(stdout);
864 info(1);
865 }
866 exit(0);
867 #endif
868 }
869
870 static void
871 info(register int verbose)
872 {
873 struct pcap_stat stat;
874
875 if (pcap_stats(pd, &stat) < 0) {
876 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
877 return;
878 }
879
880 if (!verbose)
881 fprintf(stderr, "%s: ", program_name);
882
883 (void)fprintf(stderr, "%u packets captured", packets_captured);
884 if (!verbose)
885 fputs(", ", stderr);
886 else
887 putc('\n', stderr);
888 (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
889 if (!verbose)
890 fputs(", ", stderr);
891 else
892 putc('\n', stderr);
893 (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
894 infoprint = 0;
895 }
896
897 static void
898 reverse(char *s)
899 {
900 int i, j, c;
901
902 for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
903 c = s[i];
904 s[i] = s[j];
905 s[j] = c;
906 }
907 }
908
909
910 static void
911 swebitoa(unsigned int n, char *s)
912 {
913 unsigned int i;
914
915 i = 0;
916 do {
917 s[i++] = n % 10 + '0';
918 } while ((n /= 10) > 0);
919
920 s[i] = '\0';
921 reverse(s);
922 }
923
924 static void
925 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
926 {
927 struct dump_info *dump_info;
928 static uint cnt = 2;
929 char *name;
930
931 ++packets_captured;
932
933 ++infodelay;
934
935 dump_info = (struct dump_info *)user;
936
937 /*
938 * XXX - this won't prevent capture files from getting
939 * larger than Cflag - the last packet written to the
940 * file could put it over Cflag.
941 */
942 if (ftell((FILE *)dump_info->p) > Cflag) {
943 /*
944 * Close the current file and open a new one.
945 */
946 pcap_dump_close(dump_info->p);
947 if (cnt >= 1000)
948 error("too many output files");
949 name = (char *) malloc(strlen(dump_info->WFileName) + 4);
950 if (name == NULL)
951 error("dump_packet_and_trunc: malloc");
952 strcpy(name, dump_info->WFileName);
953 swebitoa(cnt, name + strlen(dump_info->WFileName));
954 cnt++;
955 dump_info->p = pcap_dump_open(dump_info->pd, name);
956 free(name);
957 if (dump_info->p == NULL)
958 error("%s", pcap_geterr(pd));
959 }
960
961 pcap_dump((u_char *)dump_info->p, h, sp);
962 #ifdef HAVE_PCAP_DUMP_FLUSH
963 if (Uflag)
964 pcap_dump_flush(dump_info->p);
965 #endif
966
967 --infodelay;
968 if (infoprint)
969 info(0);
970 }
971
972 static void
973 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
974 {
975 ++packets_captured;
976
977 ++infodelay;
978
979 pcap_dump(user, h, sp);
980 #ifdef HAVE_PCAP_DUMP_FLUSH
981 if (Uflag)
982 pcap_dump_flush((pcap_dumper_t *)user);
983 #endif
984
985 --infodelay;
986 if (infoprint)
987 info(0);
988 }
989
990 static void
991 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
992 {
993 struct print_info *print_info;
994 u_int hdrlen;
995
996 ++packets_captured;
997
998 ++infodelay;
999 ts_print(&h->ts);
1000
1001 print_info = (struct print_info *)user;
1002
1003 /*
1004 * Some printers want to check that they're not walking off the
1005 * end of the packet.
1006 * Rather than pass it all the way down, we set this global.
1007 */
1008 snapend = sp + h->caplen;
1009
1010 hdrlen = (*print_info->printer)(h, sp);
1011 if (xflag) {
1012 /*
1013 * Print the raw packet data.
1014 */
1015 if (xflag > 1) {
1016 /*
1017 * Include the link-layer header.
1018 */
1019 hex_print("\n\t", sp, h->caplen);
1020 } else {
1021 /*
1022 * Don't include the link-layer header - and if
1023 * we have nothing past the link-layer header,
1024 * print nothing.
1025 */
1026 if (h->caplen > hdrlen)
1027 hex_print("\n\t", sp + hdrlen,
1028 h->caplen - hdrlen);
1029 }
1030 } else if (Xflag) {
1031 /*
1032 * Print the raw packet data.
1033 */
1034 if (Xflag > 1) {
1035 /*
1036 * Include the link-layer header.
1037 */
1038 ascii_print("\n\t", sp, h->caplen);
1039 } else {
1040 /*
1041 * Don't include the link-layer header - and if
1042 * we have nothing past the link-layer header,
1043 * print nothing.
1044 */
1045 if (h->caplen > hdrlen)
1046 ascii_print("\n\t", sp + hdrlen,
1047 h->caplen - hdrlen);
1048 }
1049 }
1050
1051 putchar('\n');
1052
1053 --infodelay;
1054 if (infoprint)
1055 info(0);
1056 }
1057
1058 #ifdef WIN32
1059 /*
1060 * XXX - there should really be libpcap calls to get the version
1061 * number as a string (the string would be generated from #defines
1062 * at run time, so that it's not generated from string constants
1063 * in the library, as, on many UNIX systems, those constants would
1064 * be statically linked into the application executable image, and
1065 * would thus reflect the version of libpcap on the system on
1066 * which the application was *linked*, not the system on which it's
1067 * *running*.
1068 *
1069 * That routine should be documented, unlike the "version[]"
1070 * string, so that UNIX vendors providing their own libpcaps
1071 * don't omit it (as a couple of vendors have...).
1072 *
1073 * Packet.dll should perhaps also export a routine to return the
1074 * version number of the Packet.dll code, to supply the
1075 * "Wpcap_version" information on Windows.
1076 */
1077 char WDversion[]="current-cvs.tcpdump.org";
1078 char version[]="current-cvs.tcpdump.org";
1079 char pcap_version[]="current-cvs.tcpdump.org";
1080 char Wpcap_version[]="3.1";
1081 #endif
1082
1083 /*
1084 * By default, print the specified data out in hex.
1085 */
1086 void
1087 default_print(register const u_char *bp, register u_int length)
1088 {
1089 ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1090 }
1091
1092 #ifdef SIGINFO
1093 RETSIGTYPE requestinfo(int signo _U_)
1094 {
1095 if (infodelay)
1096 ++infoprint;
1097 else
1098 info(0);
1099 }
1100 #endif
1101
1102 static void
1103 usage(void)
1104 {
1105 extern char version[];
1106 #ifndef HAVE_PCAP_LIB_VERSION
1107 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1108 extern char pcap_version[];
1109 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1110 static char pcap_version[] = "unknown";
1111 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1112 #endif /* HAVE_PCAP_LIB_VERSION */
1113
1114 #ifdef HAVE_PCAP_LIB_VERSION
1115 #ifdef WIN32
1116 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1117 #else /* WIN32 */
1118 (void)fprintf(stderr, "%s version %s\n", program_name, version);
1119 #endif /* WIN32 */
1120 (void)fprintf(stderr, "%s\n",pcap_lib_version());
1121 #else /* HAVE_PCAP_LIB_VERSION */
1122 #ifdef WIN32
1123 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1124 (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1125 #else /* WIN32 */
1126 (void)fprintf(stderr, "%s version %s\n", program_name, version);
1127 (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1128 #endif /* WIN32 */
1129 #endif /* HAVE_PCAP_LIB_VERSION */
1130 (void)fprintf(stderr,
1131 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
1132 (void)fprintf(stderr,
1133 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
1134 (void)fprintf(stderr,
1135 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n");
1136 (void)fprintf(stderr,
1137 "\t\t[ expression ]\n");
1138 exit(1);
1139 }
[mirror] the TCPdump network dissector