1 /*
2 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that: (1) source code distributions
7 * retain the above copyright notice and this paragraph in its entirety, (2)
8 * distributions including binary code include the above copyright notice and
9 * this paragraph in its entirety in the documentation or other materials
10 * provided with the distribution, and (3) all advertising materials mentioning
11 * features or use of this software display the following acknowledgement:
12 * ``This product includes software developed by the University of California,
13 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14 * the University nor the names of its contributors may be used to endorse
15 * or promote products derived from this software without specific prior
16 * written permission.
17 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20 *
21 * Support for splitting captures into multiple files with a maximum
22 * file size:
23 *
24 * Copyright (c) 2001
25 * Seth Webster <swebster@sst.ll.mit.edu>
26 */
27
28 #ifndef lint
29 static const char copyright[] _U_ =
30 "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
31 The Regents of the University of California. All rights reserved.\n";
32 #endif
33
34 /*
35 * tcpdump - dump traffic on a network
36 *
37 * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
38 * Mercilessly hacked and occasionally improved since then via the
39 * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
40 */
41
42 #ifdef HAVE_CONFIG_H
43 #include "config.h"
44 #endif
45
46 /*
47 * Mac OS X may ship pcap.h from libpcap 0.6 with a libpcap based on
48 * 0.8. That means it has pcap_findalldevs() but the header doesn't
49 * define pcap_if_t, meaning that we can't actually *use* pcap_findalldevs().
50 */
51 #ifdef HAVE_PCAP_FINDALLDEVS
52 #ifndef HAVE_PCAP_IF_T
53 #undef HAVE_PCAP_FINDALLDEVS
54 #endif
55 #endif
56
57 #include <netdissect-stdinc.h>
58
59 #include <sys/stat.h>
60
61 #ifdef HAVE_FCNTL_H
62 #include <fcntl.h>
63 #endif
64
65 #ifdef HAVE_LIBCRYPTO
66 #include <openssl/crypto.h>
67 #endif
68
69 #ifdef HAVE_GETOPT_LONG
70 #include <getopt.h>
71 #else
72 #include "getopt_long.h"
73 #endif
74 /* Capsicum-specific code requires macros from <net/bpf.h>, which will fail
75 * to compile if <pcap.h> has already been included; including the headers
76 * in the opposite order works fine.
77 */
78 #ifdef HAVE_CAPSICUM
79 #include <sys/capability.h>
80 #include <sys/ioccom.h>
81 #include <net/bpf.h>
82 #include <libgen.h>
83 #endif /* HAVE_CAPSICUM */
84 #include <pcap.h>
85 #include <signal.h>
86 #include <stdio.h>
87 #include <stdarg.h>
88 #include <stdlib.h>
89 #include <string.h>
90 #include <limits.h>
91 #ifndef _WIN32
92 #include <sys/wait.h>
93 #include <sys/resource.h>
94 #include <pwd.h>
95 #include <grp.h>
96 #endif /* _WIN32 */
97
98 /* capabilities convenience library */
99 /* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
100 * If HAVE_CAP_NG_H is not defined, undefine HAVE_LIBCAP_NG.
101 * Thus, the later tests are done only on HAVE_LIBCAP_NG.
102 */
103 #ifdef HAVE_LIBCAP_NG
104 #ifdef HAVE_CAP_NG_H
105 #include <cap-ng.h>
106 #else
107 #undef HAVE_LIBCAP_NG
108 #endif /* HAVE_CAP_NG_H */
109 #endif /* HAVE_LIBCAP_NG */
110
111 #include "netdissect.h"
112 #include "interface.h"
113 #include "addrtoname.h"
114 #include "machdep.h"
115 #include "setsignal.h"
116 #include "gmt2local.h"
117 #include "pcap-missing.h"
118 #include "ascii_strcasecmp.h"
119
120 #include "print.h"
121
122 #ifndef PATH_MAX
123 #define PATH_MAX 1024
124 #endif
125
126 #ifdef SIGINFO
127 #define SIGNAL_REQ_INFO SIGINFO
128 #elif SIGUSR1
129 #define SIGNAL_REQ_INFO SIGUSR1
130 #endif
131
132 static int Bflag; /* buffer size */
133 static long Cflag; /* rotate dump files after this many bytes */
134 static int Cflag_count; /* Keep track of which file number we're writing */
135 static int Dflag; /* list available devices and exit */
136 /*
137 * This is exported because, in some versions of libpcap, if libpcap
138 * is built with optimizer debugging code (which is *NOT* the default
139 * configuration!), the library *imports*(!) a variable named dflag,
140 * under the expectation that tcpdump is exporting it, to govern
141 * how much debugging information to print when optimizing
142 * the generated BPF code.
143 *
144 * This is a horrible hack; newer versions of libpcap don't import
145 * dflag but, instead, *if* built with optimizer debugging code,
146 * *export* a routine to set that flag.
147 */
148 int dflag; /* print filter code */
149 static int Gflag; /* rotate dump files after this many seconds */
150 static int Gflag_count; /* number of files created with Gflag rotation */
151 static time_t Gflag_time; /* The last time_t the dump file was rotated. */
152 static int Lflag; /* list available data link types and exit */
153 static int Iflag; /* rfmon (monitor) mode */
154 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
155 static int Jflag; /* list available time stamp types */
156 #endif
157 static int jflag = -1; /* packet time stamp source */
158 static int pflag; /* don't go promiscuous */
159 #ifdef HAVE_PCAP_SETDIRECTION
160 static int Qflag = -1; /* restrict captured packet by send/receive direction */
161 #endif
162 static int Uflag; /* "unbuffered" output of dump files */
163 static int Wflag; /* recycle output files after this number of files */
164 static int WflagChars;
165 static char *zflag = NULL; /* compress each savefile using a specified command (like gzip or bzip2) */
166 static int immediate_mode;
167
168 static int infodelay;
169 static int infoprint;
170
171 char *program_name;
172
173 /* Forwards */
174 static void error(FORMAT_STRING(const char *), ...) NORETURN PRINTFLIKE(1, 2);
175 static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
176 static void exit_tcpdump(int) NORETURN;
177 static RETSIGTYPE cleanup(int);
178 static RETSIGTYPE child_cleanup(int);
179 static void print_version(void);
180 static void print_usage(void);
181 static void show_tstamp_types_and_exit(pcap_t *, const char *device) NORETURN;
182 static void show_dlts_and_exit(pcap_t *, const char *device) NORETURN;
183 #ifdef HAVE_PCAP_FINDALLDEVS
184 static void show_devices_and_exit (void) NORETURN;
185 #endif
186
187 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
188 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
189 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
190 static void droproot(const char *, const char *);
191
192 #ifdef SIGNAL_REQ_INFO
193 RETSIGTYPE requestinfo(int);
194 #endif
195
196 #if defined(USE_WIN32_MM_TIMER)
197 #include <MMsystem.h>
198 static UINT timer_id;
199 static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
200 #elif defined(HAVE_ALARM)
201 static void verbose_stats_dump(int sig);
202 #endif
203
204 static void info(int);
205 static u_int packets_captured;
206
207 #ifdef HAVE_PCAP_FINDALLDEVS
208 static const struct tok status_flags[] = {
209 #ifdef PCAP_IF_UP
210 { PCAP_IF_UP, "Up" },
211 #endif
212 #ifdef PCAP_IF_RUNNING
213 { PCAP_IF_RUNNING, "Running" },
214 #endif
215 { PCAP_IF_LOOPBACK, "Loopback" },
216 { 0, NULL }
217 };
218 #endif
219
220 static pcap_t *pd;
221
222 static int supports_monitor_mode;
223
224 extern int optind;
225 extern int opterr;
226 extern char *optarg;
227
228 struct dump_info {
229 char *WFileName;
230 char *CurrentFileName;
231 pcap_t *pd;
232 pcap_dumper_t *p;
233 #ifdef HAVE_CAPSICUM
234 int dirfd;
235 #endif
236 };
237
238 #if defined(HAVE_PCAP_SET_PARSER_DEBUG)
239 /*
240 * We have pcap_set_parser_debug() in libpcap; declare it (it's not declared
241 * by any libpcap header, because it's a special hack, only available if
242 * libpcap was configured to include it, and only intended for use by
243 * libpcap developers trying to debug the parser for filter expressions).
244 */
245 #ifdef _WIN32
246 __declspec(dllimport)
247 #else /* _WIN32 */
248 extern
249 #endif /* _WIN32 */
250 void pcap_set_parser_debug(int);
251 #elif defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
252 /*
253 * We don't have pcap_set_parser_debug() in libpcap, but we do have
254 * pcap_debug or yydebug. Make a local version of pcap_set_parser_debug()
255 * to set the flag, and define HAVE_PCAP_SET_PARSER_DEBUG.
256 */
257 static void
pcap_set_parser_debug(int value)258 pcap_set_parser_debug(int value)
259 {
260 #ifdef HAVE_PCAP_DEBUG
261 extern int pcap_debug;
262
263 pcap_debug = value;
264 #else /* HAVE_PCAP_DEBUG */
265 extern int yydebug;
266
267 yydebug = value;
268 #endif /* HAVE_PCAP_DEBUG */
269 }
270
271 #define HAVE_PCAP_SET_PARSER_DEBUG
272 #endif
273
274 #if defined(HAVE_PCAP_SET_OPTIMIZER_DEBUG)
275 /*
276 * We have pcap_set_optimizer_debug() in libpcap; declare it (it's not declared
277 * by any libpcap header, because it's a special hack, only available if
278 * libpcap was configured to include it, and only intended for use by
279 * libpcap developers trying to debug the optimizer for filter expressions).
280 */
281 #ifdef _WIN32
282 __declspec(dllimport)
283 #else /* _WIN32 */
284 extern
285 #endif /* _WIN32 */
286 void pcap_set_optimizer_debug(int);
287 #endif
288
289 /* VARARGS */
290 static void
error(const char * fmt,...)291 error(const char *fmt, ...)
292 {
293 va_list ap;
294
295 (void)fprintf(stderr, "%s: ", program_name);
296 va_start(ap, fmt);
297 (void)vfprintf(stderr, fmt, ap);
298 va_end(ap);
299 if (*fmt) {
300 fmt += strlen(fmt);
301 if (fmt[-1] != '\n')
302 (void)fputc('\n', stderr);
303 }
304 exit_tcpdump(1);
305 /* NOTREACHED */
306 }
307
308 /* VARARGS */
309 static void
warning(const char * fmt,...)310 warning(const char *fmt, ...)
311 {
312 va_list ap;
313
314 (void)fprintf(stderr, "%s: WARNING: ", program_name);
315 va_start(ap, fmt);
316 (void)vfprintf(stderr, fmt, ap);
317 va_end(ap);
318 if (*fmt) {
319 fmt += strlen(fmt);
320 if (fmt[-1] != '\n')
321 (void)fputc('\n', stderr);
322 }
323 }
324
325 static void
exit_tcpdump(int status)326 exit_tcpdump(int status)
327 {
328 nd_cleanup();
329 exit(status);
330 }
331
332 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
333 static void
show_tstamp_types_and_exit(pcap_t * pc,const char * device)334 show_tstamp_types_and_exit(pcap_t *pc, const char *device)
335 {
336 int n_tstamp_types;
337 int *tstamp_types = 0;
338 const char *tstamp_type_name;
339 int i;
340
341 n_tstamp_types = pcap_list_tstamp_types(pc, &tstamp_types);
342 if (n_tstamp_types < 0)
343 error("%s", pcap_geterr(pc));
344
345 if (n_tstamp_types == 0) {
346 fprintf(stderr, "Time stamp type cannot be set for %s\n",
347 device);
348 exit_tcpdump(0);
349 }
350 fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
351 device);
352 for (i = 0; i < n_tstamp_types; i++) {
353 tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
354 if (tstamp_type_name != NULL) {
355 (void) fprintf(stderr, " %s (%s)\n", tstamp_type_name,
356 pcap_tstamp_type_val_to_description(tstamp_types[i]));
357 } else {
358 (void) fprintf(stderr, " %d\n", tstamp_types[i]);
359 }
360 }
361 pcap_free_tstamp_types(tstamp_types);
362 exit_tcpdump(0);
363 }
364 #endif
365
366 static void
show_dlts_and_exit(pcap_t * pc,const char * device)367 show_dlts_and_exit(pcap_t *pc, const char *device)
368 {
369 int n_dlts, i;
370 int *dlts = 0;
371 const char *dlt_name;
372
373 n_dlts = pcap_list_datalinks(pc, &dlts);
374 if (n_dlts < 0)
375 error("%s", pcap_geterr(pc));
376 else if (n_dlts == 0 || !dlts)
377 error("No data link types.");
378
379 /*
380 * If the interface is known to support monitor mode, indicate
381 * whether these are the data link types available when not in
382 * monitor mode, if -I wasn't specified, or when in monitor mode,
383 * when -I was specified (the link-layer types available in
384 * monitor mode might be different from the ones available when
385 * not in monitor mode).
386 */
387 if (supports_monitor_mode)
388 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
389 device,
390 Iflag ? "when in monitor mode" : "when not in monitor mode");
391 else
392 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
393 device);
394
395 for (i = 0; i < n_dlts; i++) {
396 dlt_name = pcap_datalink_val_to_name(dlts[i]);
397 if (dlt_name != NULL) {
398 (void) fprintf(stderr, " %s (%s)", dlt_name,
399 pcap_datalink_val_to_description(dlts[i]));
400
401 /*
402 * OK, does tcpdump handle that type?
403 */
404 if (!has_printer(dlts[i]))
405 (void) fprintf(stderr, " (printing not supported)");
406 fprintf(stderr, "\n");
407 } else {
408 (void) fprintf(stderr, " DLT %d (printing not supported)\n",
409 dlts[i]);
410 }
411 }
412 #ifdef HAVE_PCAP_FREE_DATALINKS
413 pcap_free_datalinks(dlts);
414 #endif
415 exit_tcpdump(0);
416 }
417
418 #ifdef HAVE_PCAP_FINDALLDEVS
419 static void
show_devices_and_exit(void)420 show_devices_and_exit (void)
421 {
422 pcap_if_t *dev, *devlist;
423 char ebuf[PCAP_ERRBUF_SIZE];
424 int i;
425
426 if (pcap_findalldevs(&devlist, ebuf) < 0)
427 error("%s", ebuf);
428 for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
429 printf("%d.%s", i+1, dev->name);
430 if (dev->description != NULL)
431 printf(" (%s)", dev->description);
432 if (dev->flags != 0)
433 printf(" [%s]", bittok2str(status_flags, "none", dev->flags));
434 printf("\n");
435 }
436 pcap_freealldevs(devlist);
437 exit_tcpdump(0);
438 }
439 #endif /* HAVE_PCAP_FINDALLDEVS */
440
441 /*
442 * Short options.
443 *
444 * Note that there we use all letters for short options except for g, k,
445 * o, and P, and those are used by other versions of tcpdump, and we should
446 * only use them for the same purposes that the other versions of tcpdump
447 * use them:
448 *
449 * OS X tcpdump uses -g to force non--v output for IP to be on one
450 * line, making it more "g"repable;
451 *
452 * OS X tcpdump uses -k to specify that packet comments in pcap-ng files
453 * should be printed;
454 *
455 * OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
456 * for hosts sending TCP SYN packets;
457 *
458 * OS X tcpdump uses -P to indicate that -w should write pcap-ng rather
459 * than pcap files.
460 *
461 * OS X tcpdump also uses -Q to specify expressions that match packet
462 * metadata, including but not limited to the packet direction.
463 * The expression syntax is different from a simple "in|out|inout",
464 * and those expressions aren't accepted by OS X tcpdump, but the
465 * equivalents would be "in" = "dir=in", "out" = "dir=out", and
466 * "inout" = "dir=in or dir=out", and the parser could conceivably
467 * special-case "in", "out", and "inout" as expressions for backwards
468 * compatibility, so all is not (yet) lost.
469 */
470
471 /*
472 * Set up flags that might or might not be supported depending on the
473 * version of libpcap we're using.
474 */
475 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
476 #define B_FLAG "B:"
477 #define B_FLAG_USAGE " [ -B size ]"
478 #else /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
479 #define B_FLAG
480 #define B_FLAG_USAGE
481 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
482
483 #ifdef HAVE_PCAP_CREATE
484 #define I_FLAG "I"
485 #else /* HAVE_PCAP_CREATE */
486 #define I_FLAG
487 #endif /* HAVE_PCAP_CREATE */
488
489 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
490 #define j_FLAG "j:"
491 #define j_FLAG_USAGE " [ -j tstamptype ]"
492 #define J_FLAG "J"
493 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
494 #define j_FLAG
495 #define j_FLAG_USAGE
496 #define J_FLAG
497 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
498
499 #ifdef HAVE_PCAP_FINDALLDEVS
500 #define D_FLAG "D"
501 #else
502 #define D_FLAG
503 #endif
504
505 #ifdef HAVE_PCAP_DUMP_FLUSH
506 #define U_FLAG "U"
507 #else
508 #define U_FLAG
509 #endif
510
511 #ifdef HAVE_PCAP_SETDIRECTION
512 #define Q_FLAG "Q:"
513 #else
514 #define Q_FLAG
515 #endif
516
517 #define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:s:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
518
519 /*
520 * Long options.
521 *
522 * We do not currently have long options corresponding to all short
523 * options; we should probably pick appropriate option names for them.
524 *
525 * However, the short options where the number of times the option is
526 * specified matters, such as -v and -d and -t, should probably not
527 * just map to a long option, as saying
528 *
529 * tcpdump --verbose --verbose
530 *
531 * doesn't make sense; it should be --verbosity={N} or something such
532 * as that.
533 *
534 * For long options with no corresponding short options, we define values
535 * outside the range of ASCII graphic characters, make that the last
536 * component of the entry for the long option, and have a case for that
537 * option in the switch statement.
538 */
539 #define OPTION_VERSION 128
540 #define OPTION_TSTAMP_PRECISION 129
541 #define OPTION_IMMEDIATE_MODE 130
542
543 static const struct option longopts[] = {
544 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
545 { "buffer-size", required_argument, NULL, 'B' },
546 #endif
547 { "list-interfaces", no_argument, NULL, 'D' },
548 { "help", no_argument, NULL, 'h' },
549 { "interface", required_argument, NULL, 'i' },
550 #ifdef HAVE_PCAP_CREATE
551 { "monitor-mode", no_argument, NULL, 'I' },
552 #endif
553 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
554 { "time-stamp-type", required_argument, NULL, 'j' },
555 { "list-time-stamp-types", no_argument, NULL, 'J' },
556 #endif
557 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
558 { "time-stamp-precision", required_argument, NULL, OPTION_TSTAMP_PRECISION},
559 #endif
560 { "dont-verify-checksums", no_argument, NULL, 'K' },
561 { "list-data-link-types", no_argument, NULL, 'L' },
562 { "no-optimize", no_argument, NULL, 'O' },
563 { "no-promiscuous-mode", no_argument, NULL, 'p' },
564 #ifdef HAVE_PCAP_SETDIRECTION
565 { "direction", required_argument, NULL, 'Q' },
566 #endif
567 { "snapshot-length", required_argument, NULL, 's' },
568 { "absolute-tcp-sequence-numbers", no_argument, NULL, 'S' },
569 #ifdef HAVE_PCAP_DUMP_FLUSH
570 { "packet-buffered", no_argument, NULL, 'U' },
571 #endif
572 { "linktype", required_argument, NULL, 'y' },
573 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
574 { "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
575 #endif
576 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
577 { "debug-filter-parser", no_argument, NULL, 'Y' },
578 #endif
579 { "relinquish-privileges", required_argument, NULL, 'Z' },
580 { "number", no_argument, NULL, '#' },
581 { "version", no_argument, NULL, OPTION_VERSION },
582 { NULL, 0, NULL, 0 }
583 };
584
585 #ifndef _WIN32
586 /* Drop root privileges and chroot if necessary */
587 static void
droproot(const char * username,const char * chroot_dir)588 droproot(const char *username, const char *chroot_dir)
589 {
590 struct passwd *pw = NULL;
591
592 if (chroot_dir && !username) {
593 fprintf(stderr, "%s: Chroot without dropping root is insecure\n",
594 program_name);
595 exit_tcpdump(1);
596 }
597
598 pw = getpwnam(username);
599 if (pw) {
600 if (chroot_dir) {
601 if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
602 fprintf(stderr, "%s: Couldn't chroot/chdir to '%.64s': %s\n",
603 program_name, chroot_dir, pcap_strerror(errno));
604 exit_tcpdump(1);
605 }
606 }
607 #ifdef HAVE_LIBCAP_NG
608 {
609 int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
610 if (ret < 0) {
611 fprintf(stderr, "error : ret %d\n", ret);
612 } else {
613 fprintf(stderr, "dropped privs to %s\n", username);
614 }
615 }
616 #else
617 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
618 setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
619 fprintf(stderr, "%s: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
620 program_name, username,
621 (unsigned long)pw->pw_uid,
622 (unsigned long)pw->pw_gid,
623 pcap_strerror(errno));
624 exit_tcpdump(1);
625 }
626 else {
627 fprintf(stderr, "dropped privs to %s\n", username);
628 }
629 #endif /* HAVE_LIBCAP_NG */
630 }
631 else {
632 fprintf(stderr, "%s: Couldn't find user '%.32s'\n",
633 program_name, username);
634 exit_tcpdump(1);
635 }
636 #ifdef HAVE_LIBCAP_NG
637 /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
638 capng_updatev(
639 CAPNG_DROP,
640 CAPNG_EFFECTIVE | CAPNG_PERMITTED,
641 CAP_SETUID,
642 CAP_SETGID,
643 CAP_SYS_CHROOT,
644 -1);
645 capng_apply(CAPNG_SELECT_BOTH);
646 #endif /* HAVE_LIBCAP_NG */
647
648 }
649 #endif /* _WIN32 */
650
651 static int
getWflagChars(int x)652 getWflagChars(int x)
653 {
654 int c = 0;
655
656 x -= 1;
657 while (x > 0) {
658 c += 1;
659 x /= 10;
660 }
661
662 return c;
663 }
664
665
666 static void
MakeFilename(char * buffer,char * orig_name,int cnt,int max_chars)667 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
668 {
669 char *filename = malloc(PATH_MAX + 1);
670 if (filename == NULL)
671 error("Makefilename: malloc");
672
673 /* Process with strftime if Gflag is set. */
674 if (Gflag != 0) {
675 struct tm *local_tm;
676
677 /* Convert Gflag_time to a usable format */
678 if ((local_tm = localtime(&Gflag_time)) == NULL) {
679 error("MakeTimedFilename: localtime");
680 }
681
682 /* There's no good way to detect an error in strftime since a return
683 * value of 0 isn't necessarily failure.
684 */
685 strftime(filename, PATH_MAX, orig_name, local_tm);
686 } else {
687 strncpy(filename, orig_name, PATH_MAX);
688 }
689
690 if (cnt == 0 && max_chars == 0)
691 strncpy(buffer, filename, PATH_MAX + 1);
692 else
693 if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
694 /* Report an error if the filename is too large */
695 error("too many output files or filename is too long (> %d)", PATH_MAX);
696 free(filename);
697 }
698
699 static char *
get_next_file(FILE * VFile,char * ptr)700 get_next_file(FILE *VFile, char *ptr)
701 {
702 char *ret;
703
704 ret = fgets(ptr, PATH_MAX, VFile);
705 if (!ret)
706 return NULL;
707
708 if (ptr[strlen(ptr) - 1] == '\n')
709 ptr[strlen(ptr) - 1] = '\0';
710
711 return ret;
712 }
713
714 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
715 static int
tstamp_precision_from_string(const char * precision)716 tstamp_precision_from_string(const char *precision)
717 {
718 if (strncmp(precision, "nano", strlen("nano")) == 0)
719 return PCAP_TSTAMP_PRECISION_NANO;
720
721 if (strncmp(precision, "micro", strlen("micro")) == 0)
722 return PCAP_TSTAMP_PRECISION_MICRO;
723
724 return -EINVAL;
725 }
726
727 static const char *
tstamp_precision_to_string(int precision)728 tstamp_precision_to_string(int precision)
729 {
730 switch (precision) {
731
732 case PCAP_TSTAMP_PRECISION_MICRO:
733 return "micro";
734
735 case PCAP_TSTAMP_PRECISION_NANO:
736 return "nano";
737
738 default:
739 return "unknown";
740 }
741 }
742 #endif
743
744 #ifdef HAVE_CAPSICUM
745 /*
746 * Ensure that, on a dump file's descriptor, we have all the rights
747 * necessary to make the standard I/O library work with an fdopen()ed
748 * FILE * from that descriptor.
749 *
750 * A long time ago, in a galaxy far far away, AT&T decided that, instead
751 * of providing separate APIs for getting and setting the FD_ flags on a
752 * descriptor, getting and setting the O_ flags on a descriptor, and
753 * locking files, they'd throw them all into a kitchen-sink fcntl() call
754 * along the lines of ioctl(), the fact that ioctl() operations are
755 * largely specific to particular character devices but fcntl() operations
756 * are either generic to all descriptors or generic to all descriptors for
757 * regular files nonwithstanding.
758 *
759 * The Capsicum people decided that fine-grained control of descriptor
760 * operations was required, so that you need to grant permission for
761 * reading, writing, seeking, and fcntl-ing. The latter, courtesy of
762 * AT&T's decision, means that "fcntl-ing" isn't a thing, but a motley
763 * collection of things, so there are *individual* fcntls for which
764 * permission needs to be granted.
765 *
766 * The FreeBSD standard I/O people implemented some optimizations that
767 * requires that the standard I/O routines be able to determine whether
768 * the descriptor for the FILE * is open append-only or not; as that
769 * descriptor could have come from an open() rather than an fopen(),
770 * that requires that it be able to do an F_GETFL fcntl() to read
771 * the O_ flags.
772 *
773 * Tcpdump uses ftell() to determine how much data has been written
774 * to a file in order to, when used with -C, determine when it's time
775 * to rotate capture files. ftell() therefore needs to do an lseek()
776 * to find out the file offset and must, thanks to the aforementioned
777 * optimization, also know whether the descriptor is open append-only
778 * or not.
779 *
780 * The net result of all the above is that we need to grant CAP_SEEK,
781 * CAP_WRITE, and CAP_FCNTL with the CAP_FCNTL_GETFL subcapability.
782 *
783 * Perhaps this is the universe's way of saying that either
784 *
785 * 1) there needs to be an fopenat() call and a pcap_dump_openat() call
786 * using it, so that Capsicum-capable tcpdump wouldn't need to do
787 * an fdopen()
788 *
789 * or
790 *
791 * 2) there needs to be a cap_fdopen() call in the FreeBSD standard
792 * I/O library that knows what rights are needed by the standard
793 * I/O library, based on the open mode, and assigns them, perhaps
794 * with an additional argument indicating, for example, whether
795 * seeking should be allowed, so that tcpdump doesn't need to know
796 * what the standard I/O library happens to require this week.
797 */
798 static void
set_dumper_capsicum_rights(pcap_dumper_t * p)799 set_dumper_capsicum_rights(pcap_dumper_t *p)
800 {
801 int fd = fileno(pcap_dump_file(p));
802 cap_rights_t rights;
803
804 cap_rights_init(&rights, CAP_SEEK, CAP_WRITE, CAP_FCNTL);
805 if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
806 error("unable to limit dump descriptor");
807 }
808 if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS) {
809 error("unable to limit dump descriptor fcntls");
810 }
811 }
812 #endif
813
814 /*
815 * Copy arg vector into a new buffer, concatenating arguments with spaces.
816 */
817 static char *
copy_argv(register char ** argv)818 copy_argv(register char **argv)
819 {
820 register char **p;
821 register u_int len = 0;
822 char *buf;
823 char *src, *dst;
824
825 p = argv;
826 if (*p == NULL)
827 return 0;
828
829 while (*p)
830 len += strlen(*p++) + 1;
831
832 buf = (char *)malloc(len);
833 if (buf == NULL)
834 error("copy_argv: malloc");
835
836 p = argv;
837 dst = buf;
838 while ((src = *p++) != NULL) {
839 while ((*dst++ = *src++) != '\0')
840 ;
841 dst[-1] = ' ';
842 }
843 dst[-1] = '\0';
844
845 return buf;
846 }
847
848 /*
849 * On Windows, we need to open the file in binary mode, so that
850 * we get all the bytes specified by the size we get from "fstat()".
851 * On UNIX, that's not necessary. O_BINARY is defined on Windows;
852 * we define it as 0 if it's not defined, so it does nothing.
853 */
854 #ifndef O_BINARY
855 #define O_BINARY 0
856 #endif
857
858 static char *
read_infile(char * fname)859 read_infile(char *fname)
860 {
861 register int i, fd, cc;
862 register char *cp;
863 struct stat buf;
864
865 fd = open(fname, O_RDONLY|O_BINARY);
866 if (fd < 0)
867 error("can't open %s: %s", fname, pcap_strerror(errno));
868
869 if (fstat(fd, &buf) < 0)
870 error("can't stat %s: %s", fname, pcap_strerror(errno));
871
872 cp = malloc((u_int)buf.st_size + 1);
873 if (cp == NULL)
874 error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
875 fname, pcap_strerror(errno));
876 cc = read(fd, cp, (u_int)buf.st_size);
877 if (cc < 0)
878 error("read %s: %s", fname, pcap_strerror(errno));
879 if (cc != buf.st_size)
880 error("short read %s (%d != %d)", fname, cc, (int)buf.st_size);
881
882 close(fd);
883 /* replace "# comment" with spaces */
884 for (i = 0; i < cc; i++) {
885 if (cp[i] == '#')
886 while (i < cc && cp[i] != '\n')
887 cp[i++] = ' ';
888 }
889 cp[cc] = '\0';
890 return (cp);
891 }
892
893 #ifdef HAVE_PCAP_FINDALLDEVS
894 static long
parse_interface_number(const char * device)895 parse_interface_number(const char *device)
896 {
897 long devnum;
898 char *end;
899
900 devnum = strtol(device, &end, 10);
901 if (device != end && *end == '\0') {
902 /*
903 * It's all-numeric, but is it a valid number?
904 */
905 if (devnum <= 0) {
906 /*
907 * No, it's not an ordinal.
908 */
909 error("Invalid adapter index");
910 }
911 return (devnum);
912 } else {
913 /*
914 * It's not all-numeric; return -1, so our caller
915 * knows that.
916 */
917 return (-1);
918 }
919 }
920
921 static char *
find_interface_by_number(long devnum)922 find_interface_by_number(long devnum)
923 {
924 pcap_if_t *dev, *devlist;
925 long i;
926 char ebuf[PCAP_ERRBUF_SIZE];
927 char *device;
928
929 if (pcap_findalldevs(&devlist, ebuf) < 0)
930 error("%s", ebuf);
931 /*
932 * Look for the devnum-th entry in the list of devices (1-based).
933 */
934 for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
935 i++, dev = dev->next)
936 ;
937 if (dev == NULL)
938 error("Invalid adapter index");
939 device = strdup(dev->name);
940 pcap_freealldevs(devlist);
941 return (device);
942 }
943 #endif
944
945 static pcap_t *
open_interface(const char * device,netdissect_options * ndo,char * ebuf)946 open_interface(const char *device, netdissect_options *ndo, char *ebuf)
947 {
948 pcap_t *pc;
949 #ifdef HAVE_PCAP_CREATE
950 int status;
951 char *cp;
952 #endif
953
954 #ifdef HAVE_PCAP_CREATE
955 pc = pcap_create(device, ebuf);
956 if (pc == NULL) {
957 /*
958 * If this failed with "No such device", that means
959 * the interface doesn't exist; return NULL, so that
960 * the caller can see whether the device name is
961 * actually an interface index.
962 */
963 if (strstr(ebuf, "No such device") != NULL)
964 return (NULL);
965 error("%s", ebuf);
966 }
967 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
968 if (Jflag)
969 show_tstamp_types_and_exit(pc, device);
970 #endif
971 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
972 status = pcap_set_tstamp_precision(pc, ndo->ndo_tstamp_precision);
973 if (status != 0)
974 error("%s: Can't set %ssecond time stamp precision: %s",
975 device,
976 tstamp_precision_to_string(ndo->ndo_tstamp_precision),
977 pcap_statustostr(status));
978 #endif
979
980 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
981 if (immediate_mode) {
982 status = pcap_set_immediate_mode(pc, 1);
983 if (status != 0)
984 error("%s: Can't set immediate mode: %s",
985 device,
986 pcap_statustostr(status));
987 }
988 #endif
989 /*
990 * Is this an interface that supports monitor mode?
991 */
992 if (pcap_can_set_rfmon(pc) == 1)
993 supports_monitor_mode = 1;
994 else
995 supports_monitor_mode = 0;
996 status = pcap_set_snaplen(pc, ndo->ndo_snaplen);
997 if (status != 0)
998 error("%s: Can't set snapshot length: %s",
999 device, pcap_statustostr(status));
1000 status = pcap_set_promisc(pc, !pflag);
1001 if (status != 0)
1002 error("%s: Can't set promiscuous mode: %s",
1003 device, pcap_statustostr(status));
1004 if (Iflag) {
1005 status = pcap_set_rfmon(pc, 1);
1006 if (status != 0)
1007 error("%s: Can't set monitor mode: %s",
1008 device, pcap_statustostr(status));
1009 }
1010 status = pcap_set_timeout(pc, 1000);
1011 if (status != 0)
1012 error("%s: pcap_set_timeout failed: %s",
1013 device, pcap_statustostr(status));
1014 if (Bflag != 0) {
1015 status = pcap_set_buffer_size(pc, Bflag);
1016 if (status != 0)
1017 error("%s: Can't set buffer size: %s",
1018 device, pcap_statustostr(status));
1019 }
1020 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1021 if (jflag != -1) {
1022 status = pcap_set_tstamp_type(pc, jflag);
1023 if (status < 0)
1024 error("%s: Can't set time stamp type: %s",
1025 device, pcap_statustostr(status));
1026 }
1027 #endif
1028 status = pcap_activate(pc);
1029 if (status < 0) {
1030 /*
1031 * pcap_activate() failed.
1032 */
1033 cp = pcap_geterr(pc);
1034 if (status == PCAP_ERROR)
1035 error("%s", cp);
1036 else if (status == PCAP_ERROR_NO_SUCH_DEVICE) {
1037 /*
1038 * Return an error for our caller to handle.
1039 */
1040 snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
1041 device, pcap_statustostr(status), cp);
1042 pcap_close(pc);
1043 return (NULL);
1044 } else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
1045 error("%s: %s\n(%s)", device,
1046 pcap_statustostr(status), cp);
1047 else
1048 error("%s: %s", device,
1049 pcap_statustostr(status));
1050 } else if (status > 0) {
1051 /*
1052 * pcap_activate() succeeded, but it's warning us
1053 * of a problem it had.
1054 */
1055 cp = pcap_geterr(pc);
1056 if (status == PCAP_WARNING)
1057 warning("%s", cp);
1058 else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1059 *cp != '\0')
1060 warning("%s: %s\n(%s)", device,
1061 pcap_statustostr(status), cp);
1062 else
1063 warning("%s: %s", device,
1064 pcap_statustostr(status));
1065 }
1066 #ifdef HAVE_PCAP_SETDIRECTION
1067 if (Qflag != -1) {
1068 status = pcap_setdirection(pc, Qflag);
1069 if (status != 0)
1070 error("%s: pcap_setdirection() failed: %s",
1071 device, pcap_geterr(pc));
1072 }
1073 #endif /* HAVE_PCAP_SETDIRECTION */
1074 #else /* HAVE_PCAP_CREATE */
1075 *ebuf = '\0';
1076 pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, 1000, ebuf);
1077 if (pc == NULL) {
1078 /*
1079 * If this failed with "No such device", that means
1080 * the interface doesn't exist; return NULL, so that
1081 * the caller can see whether the device name is
1082 * actually an interface index.
1083 */
1084 if (strstr(ebuf, "No such device") != NULL)
1085 return (NULL);
1086 error("%s", ebuf);
1087 }
1088 if (*ebuf)
1089 warning("%s", ebuf);
1090 #endif /* HAVE_PCAP_CREATE */
1091
1092 return (pc);
1093 }
1094
1095 int
main(int argc,char ** argv)1096 main(int argc, char **argv)
1097 {
1098 register int cnt, op, i;
1099 bpf_u_int32 localnet =0 , netmask = 0;
1100 int timezone_offset = 0;
1101 register char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
1102 pcap_handler callback;
1103 int dlt;
1104 const char *dlt_name;
1105 struct bpf_program fcode;
1106 #ifndef _WIN32
1107 RETSIGTYPE (*oldhandler)(int);
1108 #endif
1109 struct dump_info dumpinfo;
1110 u_char *pcap_userdata;
1111 char ebuf[PCAP_ERRBUF_SIZE];
1112 char VFileLine[PATH_MAX + 1];
1113 char *username = NULL;
1114 char *chroot_dir = NULL;
1115 char *ret = NULL;
1116 char *end;
1117 #ifdef HAVE_PCAP_FINDALLDEVS
1118 pcap_if_t *devlist;
1119 long devnum;
1120 #endif
1121 int status;
1122 FILE *VFile;
1123 #ifdef HAVE_CAPSICUM
1124 cap_rights_t rights;
1125 int cansandbox;
1126 #endif /* HAVE_CAPSICUM */
1127 int Oflag = 1; /* run filter code optimizer */
1128 int yflag_dlt = -1;
1129 const char *yflag_dlt_name = NULL;
1130
1131 netdissect_options Ndo;
1132 netdissect_options *ndo = &Ndo;
1133
1134 /*
1135 * Initialize the netdissect code.
1136 */
1137 if (nd_init(ebuf, sizeof ebuf) == -1)
1138 error("%s", ebuf);
1139
1140 memset(ndo, 0, sizeof(*ndo));
1141 ndo_set_function_pointers(ndo);
1142 ndo->ndo_snaplen = DEFAULT_SNAPLEN;
1143
1144 cnt = -1;
1145 device = NULL;
1146 infile = NULL;
1147 RFileName = NULL;
1148 VFileName = NULL;
1149 VFile = NULL;
1150 WFileName = NULL;
1151 dlt = -1;
1152 if ((cp = strrchr(argv[0], '/')) != NULL)
1153 ndo->program_name = program_name = cp + 1;
1154 else
1155 ndo->program_name = program_name = argv[0];
1156
1157 #ifdef _WIN32
1158 if (pcap_wsockinit() != 0)
1159 error("Attempting to initialize Winsock failed");
1160 #endif /* _WIN32 */
1161
1162 /*
1163 * On platforms where the CPU doesn't support unaligned loads,
1164 * force unaligned accesses to abort with SIGBUS, rather than
1165 * being fixed up (slowly) by the OS kernel; on those platforms,
1166 * misaligned accesses are bugs, and we want tcpdump to crash so
1167 * that the bugs are reported.
1168 */
1169 if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
1170 error("%s", ebuf);
1171
1172 while (
1173 (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
1174 switch (op) {
1175
1176 case 'a':
1177 /* compatibility for old -a */
1178 break;
1179
1180 case 'A':
1181 ++ndo->ndo_Aflag;
1182 break;
1183
1184 case 'b':
1185 ++ndo->ndo_bflag;
1186 break;
1187
1188 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
1189 case 'B':
1190 Bflag = atoi(optarg)*1024;
1191 if (Bflag <= 0)
1192 error("invalid packet buffer size %s", optarg);
1193 break;
1194 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
1195
1196 case 'c':
1197 cnt = atoi(optarg);
1198 if (cnt <= 0)
1199 error("invalid packet count %s", optarg);
1200 break;
1201
1202 case 'C':
1203 Cflag = atoi(optarg) * 1000000;
1204 if (Cflag <= 0)
1205 error("invalid file size %s", optarg);
1206 break;
1207
1208 case 'd':
1209 ++dflag;
1210 break;
1211
1212 case 'D':
1213 Dflag++;
1214 break;
1215
1216 case 'L':
1217 Lflag++;
1218 break;
1219
1220 case 'e':
1221 ++ndo->ndo_eflag;
1222 break;
1223
1224 case 'E':
1225 #ifndef HAVE_LIBCRYPTO
1226 warning("crypto code not compiled in");
1227 #endif
1228 ndo->ndo_espsecret = optarg;
1229 break;
1230
1231 case 'f':
1232 ++ndo->ndo_fflag;
1233 break;
1234
1235 case 'F':
1236 infile = optarg;
1237 break;
1238
1239 case 'G':
1240 Gflag = atoi(optarg);
1241 if (Gflag < 0)
1242 error("invalid number of seconds %s", optarg);
1243
1244 /* We will create one file initially. */
1245 Gflag_count = 0;
1246
1247 /* Grab the current time for rotation use. */
1248 if ((Gflag_time = time(NULL)) == (time_t)-1) {
1249 error("main: can't get current time: %s",
1250 pcap_strerror(errno));
1251 }
1252 break;
1253
1254 case 'h':
1255 print_usage();
1256 exit_tcpdump(0);
1257 break;
1258
1259 case 'H':
1260 ++ndo->ndo_Hflag;
1261 break;
1262
1263 case 'i':
1264 device = optarg;
1265 break;
1266
1267 #ifdef HAVE_PCAP_CREATE
1268 case 'I':
1269 ++Iflag;
1270 break;
1271 #endif /* HAVE_PCAP_CREATE */
1272
1273 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1274 case 'j':
1275 jflag = pcap_tstamp_type_name_to_val(optarg);
1276 if (jflag < 0)
1277 error("invalid time stamp type %s", optarg);
1278 break;
1279
1280 case 'J':
1281 Jflag++;
1282 break;
1283 #endif
1284
1285 case 'l':
1286 #ifdef _WIN32
1287 /*
1288 * _IOLBF is the same as _IOFBF in Microsoft's C
1289 * libraries; the only alternative they offer
1290 * is _IONBF.
1291 *
1292 * XXX - this should really be checking for MSVC++,
1293 * not _WIN32, if, for example, MinGW has its own
1294 * C library that is more UNIX-compatible.
1295 */
1296 setvbuf(stdout, NULL, _IONBF, 0);
1297 #else /* _WIN32 */
1298 #ifdef HAVE_SETLINEBUF
1299 setlinebuf(stdout);
1300 #else
1301 setvbuf(stdout, NULL, _IOLBF, 0);
1302 #endif
1303 #endif /* _WIN32 */
1304 break;
1305
1306 case 'K':
1307 ++ndo->ndo_Kflag;
1308 break;
1309
1310 case 'm':
1311 if (nd_have_smi_support()) {
1312 if (nd_load_smi_module(optarg, ebuf, sizeof ebuf) == -1)
1313 error("%s", ebuf);
1314 } else {
1315 (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
1316 program_name, optarg);
1317 (void)fprintf(stderr, "(no libsmi support)\n");
1318 }
1319 break;
1320
1321 case 'M':
1322 /* TCP-MD5 shared secret */
1323 #ifndef HAVE_LIBCRYPTO
1324 warning("crypto code not compiled in");
1325 #endif
1326 ndo->ndo_sigsecret = optarg;
1327 break;
1328
1329 case 'n':
1330 ++ndo->ndo_nflag;
1331 break;
1332
1333 case 'N':
1334 ++ndo->ndo_Nflag;
1335 break;
1336
1337 case 'O':
1338 Oflag = 0;
1339 break;
1340
1341 case 'p':
1342 ++pflag;
1343 break;
1344
1345 case 'q':
1346 ++ndo->ndo_qflag;
1347 ++ndo->ndo_suppress_default_print;
1348 break;
1349
1350 #ifdef HAVE_PCAP_SETDIRECTION
1351 case 'Q':
1352 if (ascii_strcasecmp(optarg, "in") == 0)
1353 Qflag = PCAP_D_IN;
1354 else if (ascii_strcasecmp(optarg, "out") == 0)
1355 Qflag = PCAP_D_OUT;
1356 else if (ascii_strcasecmp(optarg, "inout") == 0)
1357 Qflag = PCAP_D_INOUT;
1358 else
1359 error("unknown capture direction `%s'", optarg);
1360 break;
1361 #endif /* HAVE_PCAP_SETDIRECTION */
1362
1363 case 'r':
1364 RFileName = optarg;
1365 break;
1366
1367 case 's':
1368 ndo->ndo_snaplen = strtol(optarg, &end, 0);
1369 if (optarg == end || *end != '\0'
1370 || ndo->ndo_snaplen < 0 || ndo->ndo_snaplen > MAXIMUM_SNAPLEN)
1371 error("invalid snaplen %s", optarg);
1372 else if (ndo->ndo_snaplen == 0)
1373 ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
1374 break;
1375
1376 case 'S':
1377 ++ndo->ndo_Sflag;
1378 break;
1379
1380 case 't':
1381 ++ndo->ndo_tflag;
1382 break;
1383
1384 case 'T':
1385 if (ascii_strcasecmp(optarg, "vat") == 0)
1386 ndo->ndo_packettype = PT_VAT;
1387 else if (ascii_strcasecmp(optarg, "wb") == 0)
1388 ndo->ndo_packettype = PT_WB;
1389 else if (ascii_strcasecmp(optarg, "rpc") == 0)
1390 ndo->ndo_packettype = PT_RPC;
1391 else if (ascii_strcasecmp(optarg, "rtp") == 0)
1392 ndo->ndo_packettype = PT_RTP;
1393 else if (ascii_strcasecmp(optarg, "rtcp") == 0)
1394 ndo->ndo_packettype = PT_RTCP;
1395 else if (ascii_strcasecmp(optarg, "snmp") == 0)
1396 ndo->ndo_packettype = PT_SNMP;
1397 else if (ascii_strcasecmp(optarg, "cnfp") == 0)
1398 ndo->ndo_packettype = PT_CNFP;
1399 else if (ascii_strcasecmp(optarg, "tftp") == 0)
1400 ndo->ndo_packettype = PT_TFTP;
1401 else if (ascii_strcasecmp(optarg, "aodv") == 0)
1402 ndo->ndo_packettype = PT_AODV;
1403 else if (ascii_strcasecmp(optarg, "carp") == 0)
1404 ndo->ndo_packettype = PT_CARP;
1405 else if (ascii_strcasecmp(optarg, "radius") == 0)
1406 ndo->ndo_packettype = PT_RADIUS;
1407 else if (ascii_strcasecmp(optarg, "zmtp1") == 0)
1408 ndo->ndo_packettype = PT_ZMTP1;
1409 else if (ascii_strcasecmp(optarg, "vxlan") == 0)
1410 ndo->ndo_packettype = PT_VXLAN;
1411 else if (ascii_strcasecmp(optarg, "pgm") == 0)
1412 ndo->ndo_packettype = PT_PGM;
1413 else if (ascii_strcasecmp(optarg, "pgm_zmtp1") == 0)
1414 ndo->ndo_packettype = PT_PGM_ZMTP1;
1415 else if (ascii_strcasecmp(optarg, "lmp") == 0)
1416 ndo->ndo_packettype = PT_LMP;
1417 else if (ascii_strcasecmp(optarg, "resp") == 0)
1418 ndo->ndo_packettype = PT_RESP;
1419 else
1420 error("unknown packet type `%s'", optarg);
1421 break;
1422
1423 case 'u':
1424 ++ndo->ndo_uflag;
1425 break;
1426
1427 #ifdef HAVE_PCAP_DUMP_FLUSH
1428 case 'U':
1429 ++Uflag;
1430 break;
1431 #endif
1432
1433 case 'v':
1434 ++ndo->ndo_vflag;
1435 break;
1436
1437 case 'V':
1438 VFileName = optarg;
1439 break;
1440
1441 case 'w':
1442 WFileName = optarg;
1443 break;
1444
1445 case 'W':
1446 Wflag = atoi(optarg);
1447 if (Wflag <= 0)
1448 error("invalid number of output files %s", optarg);
1449 WflagChars = getWflagChars(Wflag);
1450 break;
1451
1452 case 'x':
1453 ++ndo->ndo_xflag;
1454 ++ndo->ndo_suppress_default_print;
1455 break;
1456
1457 case 'X':
1458 ++ndo->ndo_Xflag;
1459 ++ndo->ndo_suppress_default_print;
1460 break;
1461
1462 case 'y':
1463 yflag_dlt_name = optarg;
1464 yflag_dlt =
1465 pcap_datalink_name_to_val(yflag_dlt_name);
1466 if (yflag_dlt < 0)
1467 error("invalid data link type %s", yflag_dlt_name);
1468 break;
1469
1470 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
1471 case 'Y':
1472 {
1473 /* Undocumented flag */
1474 pcap_set_parser_debug(1);
1475 }
1476 break;
1477 #endif
1478 case 'z':
1479 zflag = optarg;
1480 break;
1481
1482 case 'Z':
1483 username = optarg;
1484 break;
1485
1486 case '#':
1487 ndo->ndo_packet_number = 1;
1488 break;
1489
1490 case OPTION_VERSION:
1491 print_version();
1492 exit_tcpdump(0);
1493 break;
1494
1495 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1496 case OPTION_TSTAMP_PRECISION:
1497 ndo->ndo_tstamp_precision = tstamp_precision_from_string(optarg);
1498 if (ndo->ndo_tstamp_precision < 0)
1499 error("unsupported time stamp precision");
1500 break;
1501 #endif
1502
1503 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1504 case OPTION_IMMEDIATE_MODE:
1505 immediate_mode = 1;
1506 break;
1507 #endif
1508
1509 default:
1510 print_usage();
1511 exit_tcpdump(1);
1512 /* NOTREACHED */
1513 }
1514
1515 #ifdef HAVE_PCAP_FINDALLDEVS
1516 if (Dflag)
1517 show_devices_and_exit();
1518 #endif
1519
1520 switch (ndo->ndo_tflag) {
1521
1522 case 0: /* Default */
1523 case 4: /* Default + Date*/
1524 timezone_offset = gmt2local(0);
1525 break;
1526
1527 case 1: /* No time stamp */
1528 case 2: /* Unix timeval style */
1529 case 3: /* Microseconds since previous packet */
1530 case 5: /* Microseconds since first packet */
1531 break;
1532
1533 default: /* Not supported */
1534 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1535 break;
1536 }
1537
1538 if (ndo->ndo_fflag != 0 && (VFileName != NULL || RFileName != NULL))
1539 error("-f can not be used with -V or -r");
1540
1541 if (VFileName != NULL && RFileName != NULL)
1542 error("-V and -r are mutually exclusive.");
1543
1544 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1545 /*
1546 * If we're printing dissected packets to the standard output
1547 * rather than saving raw packets to a file, and the standard
1548 * output is a terminal, use immediate mode, as the user's
1549 * probably expecting to see packets pop up immediately.
1550 */
1551 if (WFileName == NULL && isatty(1))
1552 immediate_mode = 1;
1553 #endif
1554
1555 #ifdef WITH_CHROOT
1556 /* if run as root, prepare for chrooting */
1557 if (getuid() == 0 || geteuid() == 0) {
1558 /* future extensibility for cmd-line arguments */
1559 if (!chroot_dir)
1560 chroot_dir = WITH_CHROOT;
1561 }
1562 #endif
1563
1564 #ifdef WITH_USER
1565 /* if run as root, prepare for dropping root privileges */
1566 if (getuid() == 0 || geteuid() == 0) {
1567 /* Run with '-Z root' to restore old behaviour */
1568 if (!username)
1569 username = WITH_USER;
1570 }
1571 #endif
1572
1573 if (RFileName != NULL || VFileName != NULL) {
1574 /*
1575 * If RFileName is non-null, it's the pathname of a
1576 * savefile to read. If VFileName is non-null, it's
1577 * the pathname of a file containing a list of pathnames
1578 * (one per line) of savefiles to read.
1579 *
1580 * In either case, we're reading a savefile, not doing
1581 * a live capture.
1582 */
1583 #ifndef _WIN32
1584 /*
1585 * We don't need network access, so relinquish any set-UID
1586 * or set-GID privileges we have (if any).
1587 *
1588 * We do *not* want set-UID privileges when opening a
1589 * trace file, as that might let the user read other
1590 * people's trace files (especially if we're set-UID
1591 * root).
1592 */
1593 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1594 fprintf(stderr, "Warning: setgid/setuid failed !\n");
1595 #endif /* _WIN32 */
1596 if (VFileName != NULL) {
1597 if (VFileName[0] == '-' && VFileName[1] == '\0')
1598 VFile = stdin;
1599 else
1600 VFile = fopen(VFileName, "r");
1601
1602 if (VFile == NULL)
1603 error("Unable to open file: %s\n", pcap_strerror(errno));
1604
1605 ret = get_next_file(VFile, VFileLine);
1606 if (!ret)
1607 error("Nothing in %s\n", VFileName);
1608 RFileName = VFileLine;
1609 }
1610
1611 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1612 pd = pcap_open_offline_with_tstamp_precision(RFileName,
1613 ndo->ndo_tstamp_precision, ebuf);
1614 #else
1615 pd = pcap_open_offline(RFileName, ebuf);
1616 #endif
1617
1618 if (pd == NULL)
1619 error("%s", ebuf);
1620 #ifdef HAVE_CAPSICUM
1621 cap_rights_init(&rights, CAP_READ);
1622 if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
1623 errno != ENOSYS) {
1624 error("unable to limit pcap descriptor");
1625 }
1626 #endif
1627 dlt = pcap_datalink(pd);
1628 dlt_name = pcap_datalink_val_to_name(dlt);
1629 if (dlt_name == NULL) {
1630 fprintf(stderr, "reading from file %s, link-type %u\n",
1631 RFileName, dlt);
1632 } else {
1633 fprintf(stderr,
1634 "reading from file %s, link-type %s (%s)\n",
1635 RFileName, dlt_name,
1636 pcap_datalink_val_to_description(dlt));
1637 }
1638 } else {
1639 /*
1640 * We're doing a live capture.
1641 */
1642 if (device == NULL) {
1643 /*
1644 * No interface was specified. Pick one.
1645 */
1646 #ifdef HAVE_PCAP_FINDALLDEVS
1647 /*
1648 * Find the list of interfaces, and pick
1649 * the first interface.
1650 */
1651 if (pcap_findalldevs(&devlist, ebuf) >= 0 &&
1652 devlist != NULL) {
1653 device = strdup(devlist->name);
1654 pcap_freealldevs(devlist);
1655 }
1656 #else /* HAVE_PCAP_FINDALLDEVS */
1657 /*
1658 * Use whatever interface pcap_lookupdev()
1659 * chooses.
1660 */
1661 device = pcap_lookupdev(ebuf);
1662 #endif
1663 if (device == NULL)
1664 error("%s", ebuf);
1665 }
1666
1667 /*
1668 * Try to open the interface with the specified name.
1669 */
1670 pd = open_interface(device, ndo, ebuf);
1671 if (pd == NULL) {
1672 /*
1673 * That failed. If we can get a list of
1674 * interfaces, and the interface name
1675 * is purely numeric, try to use it as
1676 * a 1-based index in the list of
1677 * interfaces.
1678 */
1679 #ifdef HAVE_PCAP_FINDALLDEVS
1680 devnum = parse_interface_number(device);
1681 if (devnum == -1) {
1682 /*
1683 * It's not a number; just report
1684 * the open error and fail.
1685 */
1686 error("%s", ebuf);
1687 }
1688
1689 /*
1690 * OK, it's a number; try to find the
1691 * interface with that index, and try
1692 * to open it.
1693 *
1694 * find_interface_by_number() exits if it
1695 * couldn't be found.
1696 */
1697 device = find_interface_by_number(devnum);
1698 pd = open_interface(device, ndo, ebuf);
1699 if (pd == NULL)
1700 error("%s", ebuf);
1701 #else /* HAVE_PCAP_FINDALLDEVS */
1702 /*
1703 * We can't get a list of interfaces; just
1704 * fail.
1705 */
1706 error("%s", ebuf);
1707 #endif /* HAVE_PCAP_FINDALLDEVS */
1708 }
1709
1710 /*
1711 * Let user own process after socket has been opened.
1712 */
1713 #ifndef _WIN32
1714 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1715 fprintf(stderr, "Warning: setgid/setuid failed !\n");
1716 #endif /* _WIN32 */
1717 #if !defined(HAVE_PCAP_CREATE) && defined(_WIN32)
1718 if(Bflag != 0)
1719 if(pcap_setbuff(pd, Bflag)==-1){
1720 error("%s", pcap_geterr(pd));
1721 }
1722 #endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
1723 if (Lflag)
1724 show_dlts_and_exit(pd, device);
1725 if (yflag_dlt >= 0) {
1726 #ifdef HAVE_PCAP_SET_DATALINK
1727 if (pcap_set_datalink(pd, yflag_dlt) < 0)
1728 error("%s", pcap_geterr(pd));
1729 #else
1730 /*
1731 * We don't actually support changing the
1732 * data link type, so we only let them
1733 * set it to what it already is.
1734 */
1735 if (yflag_dlt != pcap_datalink(pd)) {
1736 error("%s is not one of the DLTs supported by this device\n",
1737 yflag_dlt_name);
1738 }
1739 #endif
1740 (void)fprintf(stderr, "%s: data link type %s\n",
1741 program_name, yflag_dlt_name);
1742 (void)fflush(stderr);
1743 }
1744 i = pcap_snapshot(pd);
1745 if (ndo->ndo_snaplen < i) {
1746 warning("snaplen raised from %d to %d", ndo->ndo_snaplen, i);
1747 ndo->ndo_snaplen = i;
1748 }
1749 if(ndo->ndo_fflag != 0) {
1750 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1751 warning("foreign (-f) flag used but: %s", ebuf);
1752 }
1753 }
1754
1755 }
1756 if (infile)
1757 cmdbuf = read_infile(infile);
1758 else
1759 cmdbuf = copy_argv(&argv[optind]);
1760
1761 #ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
1762 pcap_set_optimizer_debug(dflag);
1763 #endif
1764 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1765 error("%s", pcap_geterr(pd));
1766 if (dflag) {
1767 bpf_dump(&fcode, dflag);
1768 pcap_close(pd);
1769 free(cmdbuf);
1770 pcap_freecode(&fcode);
1771 exit_tcpdump(0);
1772 }
1773 init_print(ndo, localnet, netmask, timezone_offset);
1774
1775 #ifndef _WIN32
1776 (void)setsignal(SIGPIPE, cleanup);
1777 (void)setsignal(SIGTERM, cleanup);
1778 (void)setsignal(SIGINT, cleanup);
1779 #endif /* _WIN32 */
1780 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1781 (void)setsignal(SIGCHLD, child_cleanup);
1782 #endif
1783 /* Cooperate with nohup(1) */
1784 #ifndef _WIN32
1785 if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1786 (void)setsignal(SIGHUP, oldhandler);
1787 #endif /* _WIN32 */
1788
1789 #ifndef _WIN32
1790 /*
1791 * If a user name was specified with "-Z", attempt to switch to
1792 * that user's UID. This would probably be used with sudo,
1793 * to allow tcpdump to be run in a special restricted
1794 * account (if you just want to allow users to open capture
1795 * devices, and can't just give users that permission,
1796 * you'd make tcpdump set-UID or set-GID).
1797 *
1798 * Tcpdump doesn't necessarily write only to one savefile;
1799 * the general only way to allow a -Z instance to write to
1800 * savefiles as the user under whose UID it's run, rather
1801 * than as the user specified with -Z, would thus be to switch
1802 * to the original user ID before opening a capture file and
1803 * then switch back to the -Z user ID after opening the savefile.
1804 * Switching to the -Z user ID only after opening the first
1805 * savefile doesn't handle the general case.
1806 */
1807
1808 if (getuid() == 0 || geteuid() == 0) {
1809 #ifdef HAVE_LIBCAP_NG
1810 /* Initialize capng */
1811 capng_clear(CAPNG_SELECT_BOTH);
1812 if (username) {
1813 capng_updatev(
1814 CAPNG_ADD,
1815 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
1816 CAP_SETUID,
1817 CAP_SETGID,
1818 -1);
1819 }
1820 if (chroot_dir) {
1821 capng_update(
1822 CAPNG_ADD,
1823 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
1824 CAP_SYS_CHROOT
1825 );
1826 }
1827
1828 if (WFileName) {
1829 capng_update(
1830 CAPNG_ADD,
1831 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
1832 CAP_DAC_OVERRIDE
1833 );
1834 }
1835 capng_apply(CAPNG_SELECT_BOTH);
1836 #endif /* HAVE_LIBCAP_NG */
1837 if (username || chroot_dir)
1838 droproot(username, chroot_dir);
1839
1840 }
1841 #endif /* _WIN32 */
1842
1843 if (pcap_setfilter(pd, &fcode) < 0)
1844 error("%s", pcap_geterr(pd));
1845 #ifdef HAVE_CAPSICUM
1846 if (RFileName == NULL && VFileName == NULL) {
1847 static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
1848
1849 /*
1850 * The various libpcap devices use a combination of
1851 * read (bpf), ioctl (bpf, netmap), poll (netmap)
1852 * so we add the relevant access rights.
1853 */
1854 cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
1855 if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
1856 errno != ENOSYS) {
1857 error("unable to limit pcap descriptor");
1858 }
1859 if (cap_ioctls_limit(pcap_fileno(pd), cmds,
1860 sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
1861 error("unable to limit ioctls on pcap descriptor");
1862 }
1863 }
1864 #endif
1865 if (WFileName) {
1866 pcap_dumper_t *p;
1867 /* Do not exceed the default PATH_MAX for files. */
1868 dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
1869
1870 if (dumpinfo.CurrentFileName == NULL)
1871 error("malloc of dumpinfo.CurrentFileName");
1872
1873 /* We do not need numbering for dumpfiles if Cflag isn't set. */
1874 if (Cflag != 0)
1875 MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1876 else
1877 MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1878
1879 p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1880 #ifdef HAVE_LIBCAP_NG
1881 /* Give up CAP_DAC_OVERRIDE capability.
1882 * Only allow it to be restored if the -C or -G flag have been
1883 * set since we may need to create more files later on.
1884 */
1885 capng_update(
1886 CAPNG_DROP,
1887 (Cflag || Gflag ? 0 : CAPNG_PERMITTED)
1888 | CAPNG_EFFECTIVE,
1889 CAP_DAC_OVERRIDE
1890 );
1891 capng_apply(CAPNG_SELECT_BOTH);
1892 #endif /* HAVE_LIBCAP_NG */
1893 if (p == NULL)
1894 error("%s", pcap_geterr(pd));
1895 #ifdef HAVE_CAPSICUM
1896 set_dumper_capsicum_rights(p);
1897 #endif
1898 if (Cflag != 0 || Gflag != 0) {
1899 #ifdef HAVE_CAPSICUM
1900 dumpinfo.WFileName = strdup(basename(WFileName));
1901 if (dumpinfo.WFileName == NULL) {
1902 error("Unable to allocate memory for file %s",
1903 WFileName);
1904 }
1905 dumpinfo.dirfd = open(dirname(WFileName),
1906 O_DIRECTORY | O_RDONLY);
1907 if (dumpinfo.dirfd < 0) {
1908 error("unable to open directory %s",
1909 dirname(WFileName));
1910 }
1911 cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
1912 CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
1913 if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
1914 errno != ENOSYS) {
1915 error("unable to limit directory rights");
1916 }
1917 if (cap_fcntls_limit(dumpinfo.dirfd, CAP_FCNTL_GETFL) < 0 &&
1918 errno != ENOSYS) {
1919 error("unable to limit dump descriptor fcntls");
1920 }
1921 #else /* !HAVE_CAPSICUM */
1922 dumpinfo.WFileName = WFileName;
1923 #endif
1924 callback = dump_packet_and_trunc;
1925 dumpinfo.pd = pd;
1926 dumpinfo.p = p;
1927 pcap_userdata = (u_char *)&dumpinfo;
1928 } else {
1929 callback = dump_packet;
1930 pcap_userdata = (u_char *)p;
1931 }
1932 #ifdef HAVE_PCAP_DUMP_FLUSH
1933 if (Uflag)
1934 pcap_dump_flush(p);
1935 #endif
1936 } else {
1937 dlt = pcap_datalink(pd);
1938 ndo->ndo_if_printer = get_if_printer(ndo, dlt);
1939 callback = print_packet;
1940 pcap_userdata = (u_char *)ndo;
1941 }
1942
1943 #ifdef SIGNAL_REQ_INFO
1944 /*
1945 * We can't get statistics when reading from a file rather
1946 * than capturing from a device.
1947 */
1948 if (RFileName == NULL)
1949 (void)setsignal(SIGNAL_REQ_INFO, requestinfo);
1950 #endif
1951
1952 if (ndo->ndo_vflag > 0 && WFileName) {
1953 /*
1954 * When capturing to a file, "-v" means tcpdump should,
1955 * every 10 seconds, "v"erbosely report the number of
1956 * packets captured.
1957 */
1958 #ifdef USE_WIN32_MM_TIMER
1959 /* call verbose_stats_dump() each 1000 +/-100msec */
1960 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1961 setvbuf(stderr, NULL, _IONBF, 0);
1962 #elif defined(HAVE_ALARM)
1963 (void)setsignal(SIGALRM, verbose_stats_dump);
1964 alarm(1);
1965 #endif
1966 }
1967
1968 if (RFileName == NULL) {
1969 /*
1970 * Live capture (if -V was specified, we set RFileName
1971 * to a file from the -V file). Print a message to
1972 * the standard error on UN*X.
1973 */
1974 if (!ndo->ndo_vflag && !WFileName) {
1975 (void)fprintf(stderr,
1976 "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1977 program_name);
1978 } else
1979 (void)fprintf(stderr, "%s: ", program_name);
1980 dlt = pcap_datalink(pd);
1981 dlt_name = pcap_datalink_val_to_name(dlt);
1982 if (dlt_name == NULL) {
1983 (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1984 device, dlt, ndo->ndo_snaplen);
1985 } else {
1986 (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1987 device, dlt_name,
1988 pcap_datalink_val_to_description(dlt), ndo->ndo_snaplen);
1989 }
1990 (void)fflush(stderr);
1991 }
1992
1993 #ifdef HAVE_CAPSICUM
1994 cansandbox = (ndo->ndo_nflag && VFileName == NULL && zflag == NULL);
1995 if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
1996 error("unable to enter the capability mode");
1997 #endif /* HAVE_CAPSICUM */
1998
1999 do {
2000 status = pcap_loop(pd, cnt, callback, pcap_userdata);
2001 if (WFileName == NULL) {
2002 /*
2003 * We're printing packets. Flush the printed output,
2004 * so it doesn't get intermingled with error output.
2005 */
2006 if (status == -2) {
2007 /*
2008 * We got interrupted, so perhaps we didn't
2009 * manage to finish a line we were printing.
2010 * Print an extra newline, just in case.
2011 */
2012 putchar('\n');
2013 }
2014 (void)fflush(stdout);
2015 }
2016 if (status == -2) {
2017 /*
2018 * We got interrupted. If we are reading multiple
2019 * files (via -V) set these so that we stop.
2020 */
2021 VFileName = NULL;
2022 ret = NULL;
2023 }
2024 if (status == -1) {
2025 /*
2026 * Error. Report it.
2027 */
2028 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
2029 program_name, pcap_geterr(pd));
2030 }
2031 if (RFileName == NULL) {
2032 /*
2033 * We're doing a live capture. Report the capture
2034 * statistics.
2035 */
2036 info(1);
2037 }
2038 pcap_close(pd);
2039 if (VFileName != NULL) {
2040 ret = get_next_file(VFile, VFileLine);
2041 if (ret) {
2042 int new_dlt;
2043
2044 RFileName = VFileLine;
2045 pd = pcap_open_offline(RFileName, ebuf);
2046 if (pd == NULL)
2047 error("%s", ebuf);
2048 #ifdef HAVE_CAPSICUM
2049 cap_rights_init(&rights, CAP_READ);
2050 if (cap_rights_limit(fileno(pcap_file(pd)),
2051 &rights) < 0 && errno != ENOSYS) {
2052 error("unable to limit pcap descriptor");
2053 }
2054 #endif
2055 new_dlt = pcap_datalink(pd);
2056 if (new_dlt != dlt) {
2057 /*
2058 * The new file has a different
2059 * link-layer header type from the
2060 * previous one.
2061 */
2062 if (WFileName != NULL) {
2063 /*
2064 * We're writing raw packets
2065 * that match the filter to
2066 * a pcap file. pcap files
2067 * don't support multiple
2068 * different link-layer
2069 * header types, so we fail
2070 * here.
2071 */
2072 error("%s: new dlt does not match original", RFileName);
2073 }
2074
2075 /*
2076 * We're printing the decoded packets;
2077 * switch to the new DLT.
2078 *
2079 * To do that, we need to change
2080 * the printer, change the DLT name,
2081 * and recompile the filter with
2082 * the new DLT.
2083 */
2084 dlt = new_dlt;
2085 ndo->ndo_if_printer = get_if_printer(ndo, dlt);
2086 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2087 error("%s", pcap_geterr(pd));
2088 }
2089
2090 /*
2091 * Set the filter on the new file.
2092 */
2093 if (pcap_setfilter(pd, &fcode) < 0)
2094 error("%s", pcap_geterr(pd));
2095
2096 /*
2097 * Report the new file.
2098 */
2099 dlt_name = pcap_datalink_val_to_name(dlt);
2100 if (dlt_name == NULL) {
2101 fprintf(stderr, "reading from file %s, link-type %u\n",
2102 RFileName, dlt);
2103 } else {
2104 fprintf(stderr,
2105 "reading from file %s, link-type %s (%s)\n",
2106 RFileName, dlt_name,
2107 pcap_datalink_val_to_description(dlt));
2108 }
2109 }
2110 }
2111 }
2112 while (ret != NULL);
2113
2114 free(cmdbuf);
2115 pcap_freecode(&fcode);
2116 exit_tcpdump(status == -1 ? 1 : 0);
2117 }
2118
2119 /* make a clean exit on interrupts */
2120 static RETSIGTYPE
cleanup(int signo _U_)2121 cleanup(int signo _U_)
2122 {
2123 #ifdef USE_WIN32_MM_TIMER
2124 if (timer_id)
2125 timeKillEvent(timer_id);
2126 timer_id = 0;
2127 #elif defined(HAVE_ALARM)
2128 alarm(0);
2129 #endif
2130
2131 #ifdef HAVE_PCAP_BREAKLOOP
2132 /*
2133 * We have "pcap_breakloop()"; use it, so that we do as little
2134 * as possible in the signal handler (it's probably not safe
2135 * to do anything with standard I/O streams in a signal handler -
2136 * the ANSI C standard doesn't say it is).
2137 */
2138 pcap_breakloop(pd);
2139 #else
2140 /*
2141 * We don't have "pcap_breakloop()"; this isn't safe, but
2142 * it's the best we can do. Print the summary if we're
2143 * not reading from a savefile - i.e., if we're doing a
2144 * live capture - and exit.
2145 */
2146 if (pd != NULL && pcap_file(pd) == NULL) {
2147 /*
2148 * We got interrupted, so perhaps we didn't
2149 * manage to finish a line we were printing.
2150 * Print an extra newline, just in case.
2151 */
2152 putchar('\n');
2153 (void)fflush(stdout);
2154 info(1);
2155 }
2156 exit_tcpdump(0);
2157 #endif
2158 }
2159
2160 /*
2161 On windows, we do not use a fork, so we do not care less about
2162 waiting a child processes to die
2163 */
2164 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2165 static RETSIGTYPE
child_cleanup(int signo _U_)2166 child_cleanup(int signo _U_)
2167 {
2168 wait(NULL);
2169 }
2170 #endif /* HAVE_FORK && HAVE_VFORK */
2171
2172 static void
info(register int verbose)2173 info(register int verbose)
2174 {
2175 struct pcap_stat stats;
2176
2177 /*
2178 * Older versions of libpcap didn't set ps_ifdrop on some
2179 * platforms; initialize it to 0 to handle that.
2180 */
2181 stats.ps_ifdrop = 0;
2182 if (pcap_stats(pd, &stats) < 0) {
2183 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
2184 infoprint = 0;
2185 return;
2186 }
2187
2188 if (!verbose)
2189 fprintf(stderr, "%s: ", program_name);
2190
2191 (void)fprintf(stderr, "%u packet%s captured", packets_captured,
2192 PLURAL_SUFFIX(packets_captured));
2193 if (!verbose)
2194 fputs(", ", stderr);
2195 else
2196 putc('\n', stderr);
2197 (void)fprintf(stderr, "%u packet%s received by filter", stats.ps_recv,
2198 PLURAL_SUFFIX(stats.ps_recv));
2199 if (!verbose)
2200 fputs(", ", stderr);
2201 else
2202 putc('\n', stderr);
2203 (void)fprintf(stderr, "%u packet%s dropped by kernel", stats.ps_drop,
2204 PLURAL_SUFFIX(stats.ps_drop));
2205 if (stats.ps_ifdrop != 0) {
2206 if (!verbose)
2207 fputs(", ", stderr);
2208 else
2209 putc('\n', stderr);
2210 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
2211 stats.ps_ifdrop, PLURAL_SUFFIX(stats.ps_ifdrop));
2212 } else
2213 putc('\n', stderr);
2214 infoprint = 0;
2215 }
2216
2217 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2218 #ifdef HAVE_FORK
2219 #define fork_subprocess() fork()
2220 #else
2221 #define fork_subprocess() vfork()
2222 #endif
2223 static void
compress_savefile(const char * filename)2224 compress_savefile(const char *filename)
2225 {
2226 pid_t child;
2227
2228 child = fork_subprocess();
2229 if (child == -1) {
2230 fprintf(stderr,
2231 "compress_savefile: fork failed: %s\n",
2232 pcap_strerror(errno));
2233 return;
2234 }
2235 if (child != 0) {
2236 /* Parent process. */
2237 return;
2238 }
2239
2240 /*
2241 * Child process.
2242 * Set to lowest priority so that this doesn't disturb the capture.
2243 */
2244 #ifdef NZERO
2245 setpriority(PRIO_PROCESS, 0, NZERO - 1);
2246 #else
2247 setpriority(PRIO_PROCESS, 0, 19);
2248 #endif
2249 if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
2250 fprintf(stderr,
2251 "compress_savefile: execlp(%s, %s) failed: %s\n",
2252 zflag,
2253 filename,
2254 pcap_strerror(errno));
2255 #ifdef HAVE_FORK
2256 exit(1);
2257 #else
2258 _exit(1);
2259 #endif
2260 }
2261 #else /* HAVE_FORK && HAVE_VFORK */
2262 static void
compress_savefile(const char * filename)2263 compress_savefile(const char *filename)
2264 {
2265 fprintf(stderr,
2266 "compress_savefile failed. Functionality not implemented under your system\n");
2267 }
2268 #endif /* HAVE_FORK && HAVE_VFORK */
2269
2270 static void
dump_packet_and_trunc(u_char * user,const struct pcap_pkthdr * h,const u_char * sp)2271 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2272 {
2273 struct dump_info *dump_info;
2274
2275 ++packets_captured;
2276
2277 ++infodelay;
2278
2279 dump_info = (struct dump_info *)user;
2280
2281 /*
2282 * XXX - this won't force the file to rotate on the specified time
2283 * boundary, but it will rotate on the first packet received after the
2284 * specified Gflag number of seconds. Note: if a Gflag time boundary
2285 * and a Cflag size boundary coincide, the time rotation will occur
2286 * first thereby cancelling the Cflag boundary (since the file should
2287 * be 0).
2288 */
2289 if (Gflag != 0) {
2290 /* Check if it is time to rotate */
2291 time_t t;
2292
2293 /* Get the current time */
2294 if ((t = time(NULL)) == (time_t)-1) {
2295 error("dump_and_trunc_packet: can't get current_time: %s",
2296 pcap_strerror(errno));
2297 }
2298
2299
2300 /* If the time is greater than the specified window, rotate */
2301 if (t - Gflag_time >= Gflag) {
2302 #ifdef HAVE_CAPSICUM
2303 FILE *fp;
2304 int fd;
2305 #endif
2306
2307 /* Update the Gflag_time */
2308 Gflag_time = t;
2309 /* Update Gflag_count */
2310 Gflag_count++;
2311 /*
2312 * Close the current file and open a new one.
2313 */
2314 pcap_dump_close(dump_info->p);
2315
2316 /*
2317 * Compress the file we just closed, if the user asked for it
2318 */
2319 if (zflag != NULL)
2320 compress_savefile(dump_info->CurrentFileName);
2321
2322 /*
2323 * Check to see if we've exceeded the Wflag (when
2324 * not using Cflag).
2325 */
2326 if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
2327 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
2328 Wflag);
2329 info(1);
2330 exit_tcpdump(0);
2331 /* NOTREACHED */
2332 }
2333 if (dump_info->CurrentFileName != NULL)
2334 free(dump_info->CurrentFileName);
2335 /* Allocate space for max filename + \0. */
2336 dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2337 if (dump_info->CurrentFileName == NULL)
2338 error("dump_packet_and_trunc: malloc");
2339 /*
2340 * Gflag was set otherwise we wouldn't be here. Reset the count
2341 * so multiple files would end with 1,2,3 in the filename.
2342 * The counting is handled with the -C flow after this.
2343 */
2344 Cflag_count = 0;
2345
2346 /*
2347 * This is always the first file in the Cflag
2348 * rotation: e.g. 0
2349 * We also don't need numbering if Cflag is not set.
2350 */
2351 if (Cflag != 0)
2352 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
2353 WflagChars);
2354 else
2355 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
2356
2357 #ifdef HAVE_LIBCAP_NG
2358 capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2359 capng_apply(CAPNG_SELECT_BOTH);
2360 #endif /* HAVE_LIBCAP_NG */
2361 #ifdef HAVE_CAPSICUM
2362 fd = openat(dump_info->dirfd,
2363 dump_info->CurrentFileName,
2364 O_CREAT | O_WRONLY | O_TRUNC, 0644);
2365 if (fd < 0) {
2366 error("unable to open file %s",
2367 dump_info->CurrentFileName);
2368 }
2369 fp = fdopen(fd, "w");
2370 if (fp == NULL) {
2371 error("unable to fdopen file %s",
2372 dump_info->CurrentFileName);
2373 }
2374 dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2375 #else /* !HAVE_CAPSICUM */
2376 dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2377 #endif
2378 #ifdef HAVE_LIBCAP_NG
2379 capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2380 capng_apply(CAPNG_SELECT_BOTH);
2381 #endif /* HAVE_LIBCAP_NG */
2382 if (dump_info->p == NULL)
2383 error("%s", pcap_geterr(pd));
2384 #ifdef HAVE_CAPSICUM
2385 set_dumper_capsicum_rights(dump_info->p);
2386 #endif
2387 }
2388 }
2389
2390 /*
2391 * XXX - this won't prevent capture files from getting
2392 * larger than Cflag - the last packet written to the
2393 * file could put it over Cflag.
2394 */
2395 if (Cflag != 0) {
2396 long size = pcap_dump_ftell(dump_info->p);
2397
2398 if (size == -1)
2399 error("ftell fails on output file");
2400 if (size > Cflag) {
2401 #ifdef HAVE_CAPSICUM
2402 FILE *fp;
2403 int fd;
2404 #endif
2405
2406 /*
2407 * Close the current file and open a new one.
2408 */
2409 pcap_dump_close(dump_info->p);
2410
2411 /*
2412 * Compress the file we just closed, if the user
2413 * asked for it.
2414 */
2415 if (zflag != NULL)
2416 compress_savefile(dump_info->CurrentFileName);
2417
2418 Cflag_count++;
2419 if (Wflag > 0) {
2420 if (Cflag_count >= Wflag)
2421 Cflag_count = 0;
2422 }
2423 if (dump_info->CurrentFileName != NULL)
2424 free(dump_info->CurrentFileName);
2425 dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2426 if (dump_info->CurrentFileName == NULL)
2427 error("dump_packet_and_trunc: malloc");
2428 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
2429 #ifdef HAVE_LIBCAP_NG
2430 capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2431 capng_apply(CAPNG_SELECT_BOTH);
2432 #endif /* HAVE_LIBCAP_NG */
2433 #ifdef HAVE_CAPSICUM
2434 fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
2435 O_CREAT | O_WRONLY | O_TRUNC, 0644);
2436 if (fd < 0) {
2437 error("unable to open file %s",
2438 dump_info->CurrentFileName);
2439 }
2440 fp = fdopen(fd, "w");
2441 if (fp == NULL) {
2442 error("unable to fdopen file %s",
2443 dump_info->CurrentFileName);
2444 }
2445 dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2446 #else /* !HAVE_CAPSICUM */
2447 dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2448 #endif
2449 #ifdef HAVE_LIBCAP_NG
2450 capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2451 capng_apply(CAPNG_SELECT_BOTH);
2452 #endif /* HAVE_LIBCAP_NG */
2453 if (dump_info->p == NULL)
2454 error("%s", pcap_geterr(pd));
2455 #ifdef HAVE_CAPSICUM
2456 set_dumper_capsicum_rights(dump_info->p);
2457 #endif
2458 }
2459 }
2460
2461 pcap_dump((u_char *)dump_info->p, h, sp);
2462 #ifdef HAVE_PCAP_DUMP_FLUSH
2463 if (Uflag)
2464 pcap_dump_flush(dump_info->p);
2465 #endif
2466
2467 --infodelay;
2468 if (infoprint)
2469 info(0);
2470 }
2471
2472 static void
dump_packet(u_char * user,const struct pcap_pkthdr * h,const u_char * sp)2473 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2474 {
2475 ++packets_captured;
2476
2477 ++infodelay;
2478
2479 pcap_dump(user, h, sp);
2480 #ifdef HAVE_PCAP_DUMP_FLUSH
2481 if (Uflag)
2482 pcap_dump_flush((pcap_dumper_t *)user);
2483 #endif
2484
2485 --infodelay;
2486 if (infoprint)
2487 info(0);
2488 }
2489
2490 static void
print_packet(u_char * user,const struct pcap_pkthdr * h,const u_char * sp)2491 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2492 {
2493 ++packets_captured;
2494
2495 ++infodelay;
2496
2497 pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
2498
2499 --infodelay;
2500 if (infoprint)
2501 info(0);
2502 }
2503
2504 #ifdef _WIN32
2505 /*
2506 * XXX - there should really be libpcap calls to get the version
2507 * number as a string (the string would be generated from #defines
2508 * at run time, so that it's not generated from string constants
2509 * in the library, as, on many UNIX systems, those constants would
2510 * be statically linked into the application executable image, and
2511 * would thus reflect the version of libpcap on the system on
2512 * which the application was *linked*, not the system on which it's
2513 * *running*.
2514 *
2515 * That routine should be documented, unlike the "version[]"
2516 * string, so that UNIX vendors providing their own libpcaps
2517 * don't omit it (as a couple of vendors have...).
2518 *
2519 * Packet.dll should perhaps also export a routine to return the
2520 * version number of the Packet.dll code, to supply the
2521 * "Wpcap_version" information on Windows.
2522 */
2523 char WDversion[]="current-git.tcpdump.org";
2524 #if !defined(HAVE_GENERATED_VERSION)
2525 char version[]="current-git.tcpdump.org";
2526 #endif
2527 char pcap_version[]="current-git.tcpdump.org";
2528 char Wpcap_version[]="3.1";
2529 #endif
2530
2531 #ifdef SIGNAL_REQ_INFO
requestinfo(int signo _U_)2532 RETSIGTYPE requestinfo(int signo _U_)
2533 {
2534 if (infodelay)
2535 ++infoprint;
2536 else
2537 info(0);
2538 }
2539 #endif
2540
2541 /*
2542 * Called once each second in verbose mode while dumping to file
2543 */
2544 #ifdef USE_WIN32_MM_TIMER
verbose_stats_dump(UINT timer_id _U_,UINT msg _U_,DWORD_PTR arg _U_,DWORD_PTR dw1 _U_,DWORD_PTR dw2 _U_)2545 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
2546 DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
2547 {
2548 if (infodelay == 0)
2549 fprintf(stderr, "Got %u\r", packets_captured);
2550 }
2551 #elif defined(HAVE_ALARM)
verbose_stats_dump(int sig _U_)2552 static void verbose_stats_dump(int sig _U_)
2553 {
2554 if (infodelay == 0)
2555 fprintf(stderr, "Got %u\r", packets_captured);
2556 alarm(1);
2557 }
2558 #endif
2559
2560 USES_APPLE_DEPRECATED_API
2561 static void
print_version(void)2562 print_version(void)
2563 {
2564 extern char version[];
2565 #ifndef HAVE_PCAP_LIB_VERSION
2566 #if defined(_WIN32) || defined(HAVE_PCAP_VERSION)
2567 extern char pcap_version[];
2568 #else /* defined(_WIN32) || defined(HAVE_PCAP_VERSION) */
2569 static char pcap_version[] = "unknown";
2570 #endif /* defined(_WIN32) || defined(HAVE_PCAP_VERSION) */
2571 #endif /* HAVE_PCAP_LIB_VERSION */
2572 const char *smi_version_string;
2573
2574 #ifdef HAVE_PCAP_LIB_VERSION
2575 #ifdef _WIN32
2576 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2577 #else /* _WIN32 */
2578 (void)fprintf(stderr, "%s version %s\n", program_name, version);
2579 #endif /* _WIN32 */
2580 (void)fprintf(stderr, "%s\n",pcap_lib_version());
2581 #else /* HAVE_PCAP_LIB_VERSION */
2582 #ifdef _WIN32
2583 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2584 (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
2585 #else /* _WIN32 */
2586 (void)fprintf(stderr, "%s version %s\n", program_name, version);
2587 (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
2588 #endif /* _WIN32 */
2589 #endif /* HAVE_PCAP_LIB_VERSION */
2590
2591 #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
2592 (void)fprintf (stderr, "%s\n", SSLeay_version(SSLEAY_VERSION));
2593 #endif
2594
2595 smi_version_string = nd_smi_version_string();
2596 if (smi_version_string != NULL)
2597 (void)fprintf (stderr, "SMI-library: %s\n", smi_version_string);
2598
2599 #if defined(__SANITIZE_ADDRESS__)
2600 (void)fprintf (stderr, "Compiled with AddressSanitizer/GCC.\n");
2601 #elif defined(__has_feature)
2602 # if __has_feature(address_sanitizer)
2603 (void)fprintf (stderr, "Compiled with AddressSanitizer/CLang.\n");
2604 # endif
2605 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
2606 }
2607 USES_APPLE_RST
2608
2609 static void
print_usage(void)2610 print_usage(void)
2611 {
2612 print_version();
2613 (void)fprintf(stderr,
2614 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ]\n", program_name);
2615 (void)fprintf(stderr,
2616 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
2617 (void)fprintf(stderr,
2618 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ] [ --number ]\n");
2619 #ifdef HAVE_PCAP_SETDIRECTION
2620 (void)fprintf(stderr,
2621 "\t\t[ -Q in|out|inout ]\n");
2622 #endif
2623 (void)fprintf(stderr,
2624 "\t\t[ -r file ] [ -s snaplen ] ");
2625 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
2626 (void)fprintf(stderr, "[ --time-stamp-precision precision ]\n");
2627 (void)fprintf(stderr,
2628 "\t\t");
2629 #endif
2630 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
2631 (void)fprintf(stderr, "[ --immediate-mode ] ");
2632 #endif
2633 (void)fprintf(stderr, "[ -T type ] [ --version ] [ -V file ]\n");
2634 (void)fprintf(stderr,
2635 "\t\t[ -w file ] [ -W filecount ] [ -y datalinktype ] [ -z postrotate-command ]\n");
2636 (void)fprintf(stderr,
2637 "\t\t[ -Z user ] [ expression ]\n");
2638 }
2639 /*
2640 * Local Variables:
2641 * c-style: whitesmith
2642 * c-basic-offset: 8
2643 * End:
2644 */
2645