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.
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
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.
21 * Support for splitting captures into multiple files with a maximum
25 * Seth Webster <swebster@sst.ll.mit.edu>
29 * tcpdump - dump traffic on a network
31 * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
32 * Mercilessly hacked and occasionally improved since then via the
33 * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
41 * Some older versions of Mac OS X may ship pcap.h from libpcap 0.6 with a
42 * libpcap based on 0.8. That means it has pcap_findalldevs() but the
43 * header doesn't define pcap_if_t, meaning that we can't actually *use*
46 #ifdef HAVE_PCAP_FINDALLDEVS
47 #ifndef HAVE_PCAP_IF_T
48 #undef HAVE_PCAP_FINDALLDEVS
52 #include "netdissect-stdinc.h"
55 * This must appear after including netdissect-stdinc.h, so that _U_ is
59 static const char copyright[] _U_ =
60 "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
61 The Regents of the University of California. All rights reserved.\n";
71 #include <openssl/crypto.h>
74 #ifdef HAVE_GETOPT_LONG
77 #include "missing/getopt_long.h"
79 /* Capsicum-specific code requires macros from <net/bpf.h>, which will fail
80 * to compile if <pcap.h> has already been included; including the headers
81 * in the opposite order works fine. For the most part anyway, because in
82 * FreeBSD <pcap/pcap.h> declares bpf_dump() instead of <net/bpf.h>. Thus
83 * interface.h takes care of it later to avoid a compiler warning.
86 #include <sys/capsicum.h>
87 #include <sys/ioccom.h>
91 #include <libcasper.h>
92 #include <casper/cap_dns.h>
94 #endif /* HAVE_CASPER */
95 #endif /* HAVE_CAPSICUM */
98 * We found pcap_open() in the capture library, so we'll be using
99 * the remote capture APIs; define PCAP_REMOTE before we include pcap.h,
100 * so we get those APIs declared, and the types and #defines that they
103 * WinPcap's headers require that PCAP_REMOTE be defined in order to get
104 * remote-capture APIs declared and types and #defines that they use
107 * (Versions of libpcap with those APIs, and thus Npcap, which is based on
108 * those versions of libpcap, don't require it.)
122 #include <sys/time.h>
123 #include <sys/wait.h>
124 #include <sys/resource.h>
130 * Pathname separator.
131 * Use this in pathnames, but do *not* use it in URLs.
134 #define PATH_SEPARATOR '\\'
136 #define PATH_SEPARATOR '/'
139 /* capabilities convenience library */
140 /* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
141 * If HAVE_CAP_NG_H is not defined, undefine HAVE_LIBCAP_NG.
142 * Thus, the later tests are done only on HAVE_LIBCAP_NG.
144 #ifdef HAVE_LIBCAP_NG
148 #undef HAVE_LIBCAP_NG
149 #endif /* HAVE_CAP_NG_H */
150 #endif /* HAVE_LIBCAP_NG */
153 #include <sys/sysctl.h>
154 #endif /* __FreeBSD__ */
156 #include "netdissect-stdinc.h"
157 #include "netdissect.h"
158 #include "interface.h"
159 #include "addrtoname.h"
161 #include "pcap-missing.h"
162 #include "ascii_strcasecmp.h"
166 #include "diag-control.h"
171 #define PATH_MAX 1024
175 #define SIGNAL_REQ_INFO SIGINFO
176 #elif defined(SIGUSR1)
177 #define SIGNAL_REQ_INFO SIGUSR1
180 #if defined(HAVE_PCAP_DUMP_FLUSH) && defined(SIGUSR2)
181 #define SIGNAL_FLUSH_PCAP SIGUSR2
184 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
185 static int Bflag; /* buffer size */
187 #ifdef HAVE_PCAP_DUMP_FTELL64
188 static int64_t Cflag; /* rotate dump files after this many bytes */
190 static long Cflag; /* rotate dump files after this many bytes */
192 static int Cflag_count; /* Keep track of which file number we're writing */
193 #ifdef HAVE_PCAP_FINDALLDEVS
194 static int Dflag; /* list available devices and exit */
196 #ifdef HAVE_PCAP_FINDALLDEVS_EX
197 static char *remote_interfaces_source; /* list available devices from this source and exit */
201 * This is exported because, in some versions of libpcap, if libpcap
202 * is built with optimizer debugging code (which is *NOT* the default
203 * configuration!), the library *imports*(!) a variable named dflag,
204 * under the expectation that tcpdump is exporting it, to govern
205 * how much debugging information to print when optimizing
206 * the generated BPF code.
208 * This is a horrible hack; newer versions of libpcap don't import
209 * dflag but, instead, *if* built with optimizer debugging code,
210 * *export* a routine to set that flag.
213 int dflag; /* print filter code */
214 static int Gflag; /* rotate dump files after this many seconds */
215 static int Gflag_count; /* number of files created with Gflag rotation */
216 static time_t Gflag_time; /* The last time_t the dump file was rotated. */
217 static int Lflag; /* list available data link types and exit */
218 static int Iflag; /* rfmon (monitor) mode */
219 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
220 static int Jflag; /* list available time stamp types */
221 static int jflag = -1; /* packet time stamp source */
223 static int lflag; /* line-buffered output */
224 static int pflag; /* don't go promiscuous */
225 #ifdef HAVE_PCAP_SETDIRECTION
226 static int Qflag = -1; /* restrict captured packet by send/receive direction */
228 #ifdef HAVE_PCAP_DUMP_FLUSH
229 static int Uflag; /* "unbuffered" output of dump files */
231 static int Wflag; /* recycle output files after this number of files */
232 static int WflagChars;
233 static char *zflag = NULL; /* compress each savefile using a specified command (like gzip or bzip2) */
234 static int timeout = 1000; /* default timeout = 1000 ms = 1 s */
235 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
236 static int immediate_mode;
238 static int count_mode;
240 static int infodelay;
241 static int infoprint;
247 * cap_channel_t *capdns;
252 static NORETURN void error(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
253 static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
254 static NORETURN void exit_tcpdump(int);
255 static void (*setsignal (int sig, void (*func)(int)))(int);
256 static void cleanup(int);
257 static void child_cleanup(int);
258 static void print_version(FILE *);
259 static void print_usage(FILE *);
260 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
261 static NORETURN void show_tstamp_types_and_exit(pcap_t *, const char *device);
263 static NORETURN void show_dlts_and_exit(pcap_t *, const char *device);
264 #ifdef HAVE_PCAP_FINDALLDEVS
265 static NORETURN void show_devices_and_exit(void);
267 #ifdef HAVE_PCAP_FINDALLDEVS_EX
268 static NORETURN void show_remote_devices_and_exit(void);
271 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
272 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
273 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
274 static void droproot(const char *, const char *);
276 #ifdef SIGNAL_REQ_INFO
277 static void requestinfo(int);
280 #ifdef SIGNAL_FLUSH_PCAP
281 static void flushpcap(int);
285 static HANDLE timer_handle = INVALID_HANDLE_VALUE;
286 static void CALLBACK verbose_stats_dump(PVOID param, BOOLEAN timer_fired);
288 static void verbose_stats_dump(int sig);
291 static void info(int);
292 static u_int packets_captured;
294 #ifdef HAVE_PCAP_FINDALLDEVS
295 static const struct tok status_flags[] = {
297 { PCAP_IF_UP, "Up" },
299 #ifdef PCAP_IF_RUNNING
300 { PCAP_IF_RUNNING, "Running" },
302 { PCAP_IF_LOOPBACK, "Loopback" },
303 #ifdef PCAP_IF_WIRELESS
304 { PCAP_IF_WIRELESS, "Wireless" },
311 static pcap_dumper_t *pdd = NULL;
313 static int supports_monitor_mode;
321 char *CurrentFileName;
324 netdissect_options *ndo;
330 #if defined(HAVE_PCAP_SET_PARSER_DEBUG)
332 * We have pcap_set_parser_debug() in libpcap; declare it (it's not declared
333 * by any libpcap header, because it's a special hack, only available if
334 * libpcap was configured to include it, and only intended for use by
335 * libpcap developers trying to debug the parser for filter expressions).
338 __declspec(dllimport)
342 void pcap_set_parser_debug(int);
343 #elif defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
345 * We don't have pcap_set_parser_debug() in libpcap, but we do have
346 * pcap_debug or yydebug. Make a local version of pcap_set_parser_debug()
347 * to set the flag, and define HAVE_PCAP_SET_PARSER_DEBUG.
350 pcap_set_parser_debug(int value)
352 #ifdef HAVE_PCAP_DEBUG
353 extern int pcap_debug;
356 #else /* HAVE_PCAP_DEBUG */
360 #endif /* HAVE_PCAP_DEBUG */
363 #define HAVE_PCAP_SET_PARSER_DEBUG
366 #if defined(HAVE_PCAP_SET_OPTIMIZER_DEBUG)
368 * We have pcap_set_optimizer_debug() in libpcap; declare it (it's not declared
369 * by any libpcap header, because it's a special hack, only available if
370 * libpcap was configured to include it, and only intended for use by
371 * libpcap developers trying to debug the optimizer for filter expressions).
374 __declspec(dllimport)
378 void pcap_set_optimizer_debug(int);
383 error(const char *fmt, ...)
387 (void)fprintf(stderr, "%s: ", program_name);
389 (void)vfprintf(stderr, fmt, ap);
394 (void)fputc('\n', stderr);
396 exit_tcpdump(S_ERR_HOST_PROGRAM);
402 warning(const char *fmt, ...)
406 (void)fprintf(stderr, "%s: WARNING: ", program_name);
408 (void)vfprintf(stderr, fmt, ap);
413 (void)fputc('\n', stderr);
418 exit_tcpdump(int status)
424 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
426 show_tstamp_types_and_exit(pcap_t *pc, const char *device)
429 int *tstamp_types = 0;
430 const char *tstamp_type_name;
433 n_tstamp_types = pcap_list_tstamp_types(pc, &tstamp_types);
434 if (n_tstamp_types < 0)
435 error("%s", pcap_geterr(pc));
437 if (n_tstamp_types == 0) {
438 fprintf(stderr, "Time stamp type cannot be set for %s\n",
440 exit_tcpdump(S_SUCCESS);
442 fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
444 for (i = 0; i < n_tstamp_types; i++) {
445 tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
446 if (tstamp_type_name != NULL) {
447 (void) fprintf(stderr, " %s (%s)\n", tstamp_type_name,
448 pcap_tstamp_type_val_to_description(tstamp_types[i]));
450 (void) fprintf(stderr, " %d\n", tstamp_types[i]);
453 pcap_free_tstamp_types(tstamp_types);
454 exit_tcpdump(S_SUCCESS);
459 show_dlts_and_exit(pcap_t *pc, const char *device)
463 const char *dlt_name;
465 n_dlts = pcap_list_datalinks(pc, &dlts);
467 error("%s", pcap_geterr(pc));
468 else if (n_dlts == 0 || !dlts)
469 error("No data link types.");
472 * If the interface is known to support monitor mode, indicate
473 * whether these are the data link types available when not in
474 * monitor mode, if -I wasn't specified, or when in monitor mode,
475 * when -I was specified (the link-layer types available in
476 * monitor mode might be different from the ones available when
477 * not in monitor mode).
479 if (supports_monitor_mode)
480 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
482 Iflag ? "when in monitor mode" : "when not in monitor mode");
484 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
487 for (i = 0; i < n_dlts; i++) {
488 dlt_name = pcap_datalink_val_to_name(dlts[i]);
489 if (dlt_name != NULL) {
490 (void) fprintf(stderr, " %s (%s)", dlt_name,
491 pcap_datalink_val_to_description(dlts[i]));
494 * OK, does tcpdump handle that type?
496 if (!has_printer(dlts[i]))
497 (void) fprintf(stderr, " (printing not supported)");
498 fprintf(stderr, "\n");
500 (void) fprintf(stderr, " DLT %d (printing not supported)\n",
504 #ifdef HAVE_PCAP_FREE_DATALINKS
505 pcap_free_datalinks(dlts);
507 exit_tcpdump(S_SUCCESS);
510 #ifdef HAVE_PCAP_FINDALLDEVS
512 show_devices_and_exit(void)
514 pcap_if_t *dev, *devlist;
515 char ebuf[PCAP_ERRBUF_SIZE];
518 if (pcap_findalldevs(&devlist, ebuf) < 0)
520 for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
521 printf("%d.%s", i+1, dev->name);
522 if (dev->description != NULL)
523 printf(" (%s)", dev->description);
524 if (dev->flags != 0) {
526 printf("%s", bittok2str(status_flags, "none", dev->flags));
527 #ifdef PCAP_IF_WIRELESS
528 if (dev->flags & PCAP_IF_WIRELESS) {
529 switch (dev->flags & PCAP_IF_CONNECTION_STATUS) {
531 case PCAP_IF_CONNECTION_STATUS_UNKNOWN:
532 printf(", Association status unknown");
535 case PCAP_IF_CONNECTION_STATUS_CONNECTED:
536 printf(", Associated");
539 case PCAP_IF_CONNECTION_STATUS_DISCONNECTED:
540 printf(", Not associated");
543 case PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE:
547 switch (dev->flags & PCAP_IF_CONNECTION_STATUS) {
549 case PCAP_IF_CONNECTION_STATUS_UNKNOWN:
550 printf(", Connection status unknown");
553 case PCAP_IF_CONNECTION_STATUS_CONNECTED:
554 printf(", Connected");
557 case PCAP_IF_CONNECTION_STATUS_DISCONNECTED:
558 printf(", Disconnected");
561 case PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE:
570 pcap_freealldevs(devlist);
571 exit_tcpdump(S_SUCCESS);
573 #endif /* HAVE_PCAP_FINDALLDEVS */
575 #ifdef HAVE_PCAP_FINDALLDEVS_EX
577 show_remote_devices_and_exit(void)
579 pcap_if_t *dev, *devlist;
580 char ebuf[PCAP_ERRBUF_SIZE];
583 if (pcap_findalldevs_ex(remote_interfaces_source, NULL, &devlist,
586 for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
587 printf("%d.%s", i+1, dev->name);
588 if (dev->description != NULL)
589 printf(" (%s)", dev->description);
591 printf(" [%s]", bittok2str(status_flags, "none", dev->flags));
594 pcap_freealldevs(devlist);
595 exit_tcpdump(S_SUCCESS);
597 #endif /* HAVE_PCAP_FINDALLDEVS */
602 * Note that there we use all letters for short options except for g, k,
603 * o, and P, and those are used by other versions of tcpdump, and we should
604 * only use them for the same purposes that the other versions of tcpdump
607 * macOS tcpdump uses -g to force non--v output for IP to be on one
608 * line, making it more "g"repable;
610 * macOS tcpdump uses -k to specify that packet comments in pcapng files
613 * OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
614 * for hosts sending TCP SYN packets;
616 * macOS tcpdump uses -P to indicate that -w should write pcapng rather
619 * macOS tcpdump also uses -Q to specify expressions that match packet
620 * metadata, including but not limited to the packet direction.
621 * The expression syntax is different from a simple "in|out|inout",
622 * and those expressions aren't accepted by macOS tcpdump, but the
623 * equivalents would be "in" = "dir=in", "out" = "dir=out", and
624 * "inout" = "dir=in or dir=out", and the parser could conceivably
625 * special-case "in", "out", and "inout" as expressions for backwards
626 * compatibility, so all is not (yet) lost.
630 * Set up flags that might or might not be supported depending on the
631 * version of libpcap we're using.
633 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
635 #define B_FLAG_USAGE " [ -B size ]"
636 #else /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
639 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
641 #ifdef HAVE_PCAP_FINDALLDEVS
647 #ifdef HAVE_PCAP_CREATE
649 #else /* HAVE_PCAP_CREATE */
651 #endif /* HAVE_PCAP_CREATE */
653 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
655 #define j_FLAG_USAGE " [ -j tstamptype ]"
657 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
661 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
664 #define m_FLAG_USAGE "[ -m module ] ..."
667 #ifdef HAVE_PCAP_SETDIRECTION
669 #define Q_FLAG_USAGE " [ -Q in|out|inout ]"
675 #ifdef HAVE_PCAP_DUMP_FLUSH
681 #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:#"
686 * We do not currently have long options corresponding to all short
687 * options; we should probably pick appropriate option names for them.
689 * However, the short options where the number of times the option is
690 * specified matters, such as -v and -d and -t, should probably not
691 * just map to a long option, as saying
693 * tcpdump --verbose --verbose
695 * doesn't make sense; it should be --verbosity={N} or something such
698 * For long options with no corresponding short options, we define values
699 * outside the range of ASCII graphic characters, make that the last
700 * component of the entry for the long option, and have a case for that
701 * option in the switch statement.
703 #define OPTION_VERSION 128
704 #define OPTION_TSTAMP_PRECISION 129
705 #define OPTION_IMMEDIATE_MODE 130
706 #define OPTION_PRINT 131
707 #define OPTION_LIST_REMOTE_INTERFACES 132
708 #define OPTION_TSTAMP_MICRO 133
709 #define OPTION_TSTAMP_NANO 134
710 #define OPTION_FP_TYPE 135
711 #define OPTION_COUNT 136
713 static const struct option longopts[] = {
714 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
715 { "buffer-size", required_argument, NULL, 'B' },
717 { "list-interfaces", no_argument, NULL, 'D' },
718 #ifdef HAVE_PCAP_FINDALLDEVS_EX
719 { "list-remote-interfaces", required_argument, NULL, OPTION_LIST_REMOTE_INTERFACES },
721 { "help", no_argument, NULL, 'h' },
722 { "interface", required_argument, NULL, 'i' },
723 #ifdef HAVE_PCAP_CREATE
724 { "monitor-mode", no_argument, NULL, 'I' },
726 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
727 { "time-stamp-type", required_argument, NULL, 'j' },
728 { "list-time-stamp-types", no_argument, NULL, 'J' },
730 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
731 { "micro", no_argument, NULL, OPTION_TSTAMP_MICRO},
732 { "nano", no_argument, NULL, OPTION_TSTAMP_NANO},
733 { "time-stamp-precision", required_argument, NULL, OPTION_TSTAMP_PRECISION},
735 { "dont-verify-checksums", no_argument, NULL, 'K' },
736 { "list-data-link-types", no_argument, NULL, 'L' },
737 { "no-optimize", no_argument, NULL, 'O' },
738 { "no-promiscuous-mode", no_argument, NULL, 'p' },
739 #ifdef HAVE_PCAP_SETDIRECTION
740 { "direction", required_argument, NULL, 'Q' },
742 { "snapshot-length", required_argument, NULL, 's' },
743 { "absolute-tcp-sequence-numbers", no_argument, NULL, 'S' },
744 #ifdef HAVE_PCAP_DUMP_FLUSH
745 { "packet-buffered", no_argument, NULL, 'U' },
747 { "linktype", required_argument, NULL, 'y' },
748 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
749 { "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
751 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
752 { "debug-filter-parser", no_argument, NULL, 'Y' },
754 { "relinquish-privileges", required_argument, NULL, 'Z' },
755 { "count", no_argument, NULL, OPTION_COUNT },
756 { "fp-type", no_argument, NULL, OPTION_FP_TYPE },
757 { "number", no_argument, NULL, '#' },
758 { "print", no_argument, NULL, OPTION_PRINT },
759 { "version", no_argument, NULL, OPTION_VERSION },
763 #ifdef HAVE_PCAP_FINDALLDEVS_EX
764 #define LIST_REMOTE_INTERFACES_USAGE "[ --list-remote-interfaces remote-source ]"
766 #define LIST_REMOTE_INTERFACES_USAGE
769 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
770 #define IMMEDIATE_MODE_USAGE " [ --immediate-mode ]"
772 #define IMMEDIATE_MODE_USAGE ""
776 /* Drop root privileges and chroot if necessary */
778 droproot(const char *username, const char *chroot_dir)
780 struct passwd *pw = NULL;
782 if (chroot_dir && !username)
783 error("Chroot without dropping root is insecure");
785 pw = getpwnam(username);
788 if (chroot(chroot_dir) != 0 || chdir ("/") != 0)
789 error("Couldn't chroot/chdir to '%.64s': %s",
790 chroot_dir, pcap_strerror(errno));
792 #ifdef HAVE_LIBCAP_NG
794 int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
796 error("capng_change_id(): return %d\n", ret);
798 fprintf(stderr, "dropped privs to %s\n", username);
801 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
802 setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0)
803 error("Couldn't change to '%.32s' uid=%lu gid=%lu: %s",
805 (unsigned long)pw->pw_uid,
806 (unsigned long)pw->pw_gid,
807 pcap_strerror(errno));
809 fprintf(stderr, "dropped privs to %s\n", username);
811 #endif /* HAVE_LIBCAP_NG */
813 error("Couldn't find user '%.32s'", username);
814 #ifdef HAVE_LIBCAP_NG
815 /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
819 CAPNG_EFFECTIVE | CAPNG_PERMITTED,
825 capng_apply(CAPNG_SELECT_BOTH);
826 #endif /* HAVE_LIBCAP_NG */
847 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
849 char *filename = malloc(PATH_MAX + 1);
850 if (filename == NULL)
851 error("%s: malloc", __func__);
852 if (strlen(orig_name) == 0)
853 error("an empty string is not a valid file name");
855 /* Process with strftime if Gflag is set. */
859 /* Convert Gflag_time to a usable format */
860 if ((local_tm = localtime(&Gflag_time)) == NULL) {
861 error("%s: localtime", __func__);
864 /* There's no good way to detect an error in strftime since a return
865 * value of 0 isn't necessarily failure; if orig_name is an empty
866 * string, the formatted string will be empty.
868 * However, the C90 standard says that, if there *is* a
869 * buffer overflow, the content of the buffer is undefined,
870 * so we must check for a buffer overflow.
872 * So we check above for an empty orig_name, and only call
873 * strftime() if it's non-empty, in which case the return
874 * value will only be 0 if the formatted date doesn't fit
877 * (We check above because, even if we don't use -G, we
878 * want a better error message than "tcpdump: : No such
879 * file or directory" for this case.)
881 if (strftime(filename, PATH_MAX, orig_name, local_tm) == 0) {
882 error("%s: strftime", __func__);
885 strncpy(filename, orig_name, PATH_MAX);
888 if (cnt == 0 && max_chars == 0)
889 strncpy(buffer, filename, PATH_MAX + 1);
891 if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
892 /* Report an error if the filename is too large */
893 error("too many output files or filename is too long (> %d)", PATH_MAX);
898 get_next_file(FILE *VFile, char *ptr)
903 ret = fgets(ptr, PATH_MAX, VFile);
908 if (len > 0 && ptr[len - 1] == '\n')
915 static cap_channel_t *
918 cap_channel_t *capcas, *capdnsloc;
919 const char *types[1];
924 error("unable to create casper process");
925 capdnsloc = cap_service_open(capcas, "system.dns");
926 /* Casper capability no longer needed. */
928 if (capdnsloc == NULL)
929 error("unable to open system.dns service");
930 /* Limit system.dns to reverse DNS lookups. */
931 types[0] = "ADDR2NAME";
932 if (cap_dns_type_limit(capdnsloc, types, 1) < 0)
933 error("unable to limit access to system.dns service");
934 families[0] = AF_INET;
935 families[1] = AF_INET6;
936 if (cap_dns_family_limit(capdnsloc, families, 2) < 0)
937 error("unable to limit access to system.dns service");
941 #endif /* HAVE_CASPER */
943 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
945 tstamp_precision_from_string(const char *precision)
947 if (strncmp(precision, "nano", strlen("nano")) == 0)
948 return PCAP_TSTAMP_PRECISION_NANO;
950 if (strncmp(precision, "micro", strlen("micro")) == 0)
951 return PCAP_TSTAMP_PRECISION_MICRO;
957 tstamp_precision_to_string(int precision)
961 case PCAP_TSTAMP_PRECISION_MICRO:
964 case PCAP_TSTAMP_PRECISION_NANO:
975 * Ensure that, on a dump file's descriptor, we have all the rights
976 * necessary to make the standard I/O library work with an fdopen()ed
977 * FILE * from that descriptor.
979 * A long time ago in a galaxy far, far away, AT&T decided that, instead
980 * of providing separate APIs for getting and setting the FD_ flags on a
981 * descriptor, getting and setting the O_ flags on a descriptor, and
982 * locking files, they'd throw them all into a kitchen-sink fcntl() call
983 * along the lines of ioctl(), the fact that ioctl() operations are
984 * largely specific to particular character devices but fcntl() operations
985 * are either generic to all descriptors or generic to all descriptors for
986 * regular files nonwithstanding.
988 * The Capsicum people decided that fine-grained control of descriptor
989 * operations was required, so that you need to grant permission for
990 * reading, writing, seeking, and fcntl-ing. The latter, courtesy of
991 * AT&T's decision, means that "fcntl-ing" isn't a thing, but a motley
992 * collection of things, so there are *individual* fcntls for which
993 * permission needs to be granted.
995 * The FreeBSD standard I/O people implemented some optimizations that
996 * requires that the standard I/O routines be able to determine whether
997 * the descriptor for the FILE * is open append-only or not; as that
998 * descriptor could have come from an open() rather than an fopen(),
999 * that requires that it be able to do an F_GETFL fcntl() to read
1002 * Tcpdump uses ftell() to determine how much data has been written
1003 * to a file in order to, when used with -C, determine when it's time
1004 * to rotate capture files. ftell() therefore needs to do an lseek()
1005 * to find out the file offset and must, thanks to the aforementioned
1006 * optimization, also know whether the descriptor is open append-only
1009 * The net result of all the above is that we need to grant CAP_SEEK,
1010 * CAP_WRITE, and CAP_FCNTL with the CAP_FCNTL_GETFL subcapability.
1012 * Perhaps this is the universe's way of saying that either
1014 * 1) there needs to be an fopenat() call and a pcap_dump_openat() call
1015 * using it, so that Capsicum-capable tcpdump wouldn't need to do
1020 * 2) there needs to be a cap_fdopen() call in the FreeBSD standard
1021 * I/O library that knows what rights are needed by the standard
1022 * I/O library, based on the open mode, and assigns them, perhaps
1023 * with an additional argument indicating, for example, whether
1024 * seeking should be allowed, so that tcpdump doesn't need to know
1025 * what the standard I/O library happens to require this week.
1028 set_dumper_capsicum_rights(pcap_dumper_t *p)
1030 int fd = fileno(pcap_dump_file(p));
1031 cap_rights_t rights;
1033 cap_rights_init(&rights, CAP_SEEK, CAP_WRITE, CAP_FCNTL);
1034 if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
1035 error("unable to limit dump descriptor");
1037 if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS) {
1038 error("unable to limit dump descriptor fcntls");
1044 * Copy arg vector into a new buffer, concatenating arguments with spaces.
1047 copy_argv(char **argv)
1059 len += strlen(*p++) + 1;
1061 buf = (char *)malloc(len);
1063 error("%s: malloc", __func__);
1067 while ((src = *p++) != NULL) {
1068 while ((*dst++ = *src++) != '\0')
1078 * On Windows, we need to open the file in binary mode, so that
1079 * we get all the bytes specified by the size we get from "fstat()".
1080 * On UNIX, that's not necessary. O_BINARY is defined on Windows;
1081 * we define it as 0 if it's not defined, so it does nothing.
1088 read_infile(char *fname)
1095 fd = open(fname, O_RDONLY|O_BINARY);
1097 error("can't open %s: %s", fname, pcap_strerror(errno));
1099 if (our_fstat(fd, &buf) < 0)
1100 error("can't stat %s: %s", fname, pcap_strerror(errno));
1103 * Reject files whose size doesn't fit into an int; a filter
1104 * *that* large will probably be too big.
1106 if (buf.st_size > INT_MAX)
1107 error("%s is too large", fname);
1109 cp = malloc((u_int)buf.st_size + 1);
1111 error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
1112 fname, pcap_strerror(errno));
1113 cc = read(fd, cp, (u_int)buf.st_size);
1115 error("read %s: %s", fname, pcap_strerror(errno));
1116 if (cc != buf.st_size)
1117 error("short read %s (%d != %d)", fname, (int) cc,
1121 /* replace "# comment" with spaces */
1122 for (i = 0; i < cc; i++) {
1124 while (i < cc && cp[i] != '\n')
1131 #ifdef HAVE_PCAP_FINDALLDEVS
1133 parse_interface_number(const char *device)
1140 * Search for a colon, terminating any scheme at the beginning
1143 p = strchr(device, ':');
1146 * We found it. Is it followed by "//"?
1148 p++; /* skip the : */
1149 if (strncmp(p, "//", 2) == 0) {
1151 * Yes. Search for the next /, at the end of the
1152 * authority part of the URL.
1154 p += 2; /* skip the // */
1158 * OK, past the / is the path.
1164 devnum = strtol(device, &end, 10);
1165 if (device != end && *end == '\0') {
1167 * It's all-numeric, but is it a valid number?
1171 * No, it's not an ordinal.
1173 error("Invalid adapter index");
1178 * It's not all-numeric; return -1, so our caller
1186 find_interface_by_number(const char *url
1187 #ifndef HAVE_PCAP_FINDALLDEVS_EX
1192 pcap_if_t *dev, *devlist;
1194 char ebuf[PCAP_ERRBUF_SIZE];
1196 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1202 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1204 * Search for a colon, terminating any scheme at the beginning
1207 endp = strchr(url, ':');
1210 * We found it. Is it followed by "//"?
1212 endp++; /* skip the : */
1213 if (strncmp(endp, "//", 2) == 0) {
1215 * Yes. Search for the next /, at the end of the
1216 * authority part of the URL.
1218 endp += 2; /* skip the // */
1219 endp = strchr(endp, '/');
1225 * OK, everything from device to endp is a URL to hand
1226 * to pcap_findalldevs_ex().
1228 endp++; /* Include the trailing / in the URL; pcap_findalldevs_ex() requires it */
1229 host_url = malloc(endp - url + 1);
1230 if (host_url == NULL && (endp - url + 1) > 0)
1231 error("Invalid allocation for host");
1233 memcpy(host_url, url, endp - url);
1234 host_url[endp - url] = '\0';
1235 status = pcap_findalldevs_ex(host_url, NULL, &devlist, ebuf);
1239 status = pcap_findalldevs(&devlist, ebuf);
1243 * Look for the devnum-th entry in the list of devices (1-based).
1245 for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
1246 i++, dev = dev->next)
1249 error("Invalid adapter index");
1250 device = strdup(dev->name);
1251 pcap_freealldevs(devlist);
1256 #ifdef HAVE_PCAP_OPEN
1258 * Prefixes for rpcap URLs.
1260 static char rpcap_prefix[] = "rpcap://";
1261 static char rpcap_ssl_prefix[] = "rpcaps://";
1265 open_interface(const char *device, netdissect_options *ndo, char *ebuf)
1268 #ifdef HAVE_PCAP_CREATE
1273 #ifdef HAVE_PCAP_OPEN
1275 * Is this an rpcap URL?
1277 if (strncmp(device, rpcap_prefix, sizeof(rpcap_prefix) - 1) == 0 ||
1278 strncmp(device, rpcap_ssl_prefix, sizeof(rpcap_ssl_prefix) - 1) == 0) {
1280 * Yes. Open it with pcap_open().
1283 pc = pcap_open(device, ndo->ndo_snaplen,
1284 pflag ? 0 : PCAP_OPENFLAG_PROMISCUOUS, timeout, NULL,
1288 * If this failed with "No such device" or "The system
1289 * cannot find the device specified", that means
1290 * the interface doesn't exist; return NULL, so that
1291 * the caller can see whether the device name is
1292 * actually an interface index.
1294 if (strstr(ebuf, "No such device") != NULL ||
1295 strstr(ebuf, "The system cannot find the device specified") != NULL)
1300 warning("%s", ebuf);
1303 #endif /* HAVE_PCAP_OPEN */
1305 #ifdef HAVE_PCAP_CREATE
1306 pc = pcap_create(device, ebuf);
1309 * If this failed with "No such device", that means
1310 * the interface doesn't exist; return NULL, so that
1311 * the caller can see whether the device name is
1312 * actually an interface index.
1314 if (strstr(ebuf, "No such device") != NULL)
1318 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1320 show_tstamp_types_and_exit(pc, device);
1322 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1323 status = pcap_set_tstamp_precision(pc, ndo->ndo_tstamp_precision);
1325 error("%s: Can't set %ssecond time stamp precision: %s",
1327 tstamp_precision_to_string(ndo->ndo_tstamp_precision),
1328 pcap_statustostr(status));
1331 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1332 if (immediate_mode) {
1333 status = pcap_set_immediate_mode(pc, 1);
1335 error("%s: Can't set immediate mode: %s",
1336 device, pcap_statustostr(status));
1340 * Is this an interface that supports monitor mode?
1342 if (pcap_can_set_rfmon(pc) == 1)
1343 supports_monitor_mode = 1;
1345 supports_monitor_mode = 0;
1346 if (ndo->ndo_snaplen != 0) {
1348 * A snapshot length was explicitly specified;
1351 status = pcap_set_snaplen(pc, ndo->ndo_snaplen);
1353 error("%s: Can't set snapshot length: %s",
1354 device, pcap_statustostr(status));
1356 status = pcap_set_promisc(pc, !pflag);
1358 error("%s: Can't set promiscuous mode: %s",
1359 device, pcap_statustostr(status));
1361 status = pcap_set_rfmon(pc, 1);
1363 error("%s: Can't set monitor mode: %s",
1364 device, pcap_statustostr(status));
1366 status = pcap_set_timeout(pc, timeout);
1368 error("%s: pcap_set_timeout failed: %s",
1369 device, pcap_statustostr(status));
1371 status = pcap_set_buffer_size(pc, Bflag);
1373 error("%s: Can't set buffer size: %s",
1374 device, pcap_statustostr(status));
1376 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1378 status = pcap_set_tstamp_type(pc, jflag);
1380 error("%s: Can't set time stamp type: %s",
1381 device, pcap_statustostr(status));
1382 else if (status > 0)
1383 warning("When trying to set timestamp type '%s' on %s: %s",
1384 pcap_tstamp_type_val_to_name(jflag), device,
1385 pcap_statustostr(status));
1388 status = pcap_activate(pc);
1391 * pcap_activate() failed.
1393 cp = pcap_geterr(pc);
1394 if (status == PCAP_ERROR)
1396 else if (status == PCAP_ERROR_NO_SUCH_DEVICE) {
1398 * Return an error for our caller to handle.
1400 snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
1401 device, pcap_statustostr(status), cp);
1402 } else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
1403 error("%s: %s\n(%s)", device,
1404 pcap_statustostr(status), cp);
1406 else if (status == PCAP_ERROR_RFMON_NOTSUP &&
1407 strncmp(device, "wlan", 4) == 0) {
1408 char parent[8], newdev[8];
1410 size_t s = sizeof(parent);
1412 snprintf(sysctl, sizeof(sysctl),
1413 "net.wlan.%d.%%parent", atoi(device + 4));
1414 sysctlbyname(sysctl, parent, &s, NULL, 0);
1415 strlcpy(newdev, device, sizeof(newdev));
1416 /* Suggest a new wlan device. */
1417 /* FIXME: incrementing the index this way is not going to work well
1418 * when the index is 9 or greater but the only consequence in this
1419 * specific case would be an error message that looks a bit odd.
1421 newdev[strlen(newdev)-1]++;
1422 error("%s is not a monitor mode VAP\n"
1423 "To create a new monitor mode VAP use:\n"
1424 " ifconfig %s create wlandev %s wlanmode monitor\n"
1425 "and use %s as the tcpdump interface",
1426 device, newdev, parent, newdev);
1430 error("%s: %s", device,
1431 pcap_statustostr(status));
1434 } else if (status > 0) {
1436 * pcap_activate() succeeded, but it's warning us
1437 * of a problem it had.
1439 cp = pcap_geterr(pc);
1440 if (status == PCAP_WARNING)
1442 else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1444 warning("%s: %s\n(%s)", device,
1445 pcap_statustostr(status), cp);
1447 warning("%s: %s", device,
1448 pcap_statustostr(status));
1450 #ifdef HAVE_PCAP_SETDIRECTION
1452 status = pcap_setdirection(pc, Qflag);
1454 error("%s: pcap_setdirection() failed: %s",
1455 device, pcap_geterr(pc));
1457 #endif /* HAVE_PCAP_SETDIRECTION */
1458 #else /* HAVE_PCAP_CREATE */
1461 * If no snapshot length was specified, or a length of 0 was
1462 * specified, default to 256KB.
1464 if (ndo->ndo_snaplen == 0)
1465 ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
1466 pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, timeout, ebuf);
1469 * If this failed with "No such device", that means
1470 * the interface doesn't exist; return NULL, so that
1471 * the caller can see whether the device name is
1472 * actually an interface index.
1474 if (strstr(ebuf, "No such device") != NULL)
1479 warning("%s", ebuf);
1480 #endif /* HAVE_PCAP_CREATE */
1486 main(int argc, char **argv)
1489 bpf_u_int32 localnet = 0, netmask = 0;
1490 char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
1492 pcap_handler callback;
1494 const char *dlt_name;
1495 struct bpf_program fcode;
1497 void (*oldhandler)(int);
1499 struct dump_info dumpinfo;
1500 u_char *pcap_userdata;
1501 char ebuf[PCAP_ERRBUF_SIZE];
1502 char VFileLine[PATH_MAX + 1];
1503 const char *username = NULL;
1505 const char *chroot_dir = NULL;
1509 #ifdef HAVE_PCAP_FINDALLDEVS
1515 #ifdef HAVE_CAPSICUM
1516 cap_rights_t rights;
1518 #endif /* HAVE_CAPSICUM */
1519 int Oflag = 1; /* run filter code optimizer */
1521 const char *yflag_dlt_name = NULL;
1524 netdissect_options Ndo;
1525 netdissect_options *ndo = &Ndo;
1528 * Initialize the netdissect code.
1530 if (nd_init(ebuf, sizeof(ebuf)) == -1)
1533 memset(ndo, 0, sizeof(*ndo));
1534 ndo_set_function_pointers(ndo);
1544 if ((cp = strrchr(argv[0], PATH_SEPARATOR)) != NULL)
1545 ndo->program_name = program_name = cp + 1;
1547 ndo->program_name = program_name = argv[0];
1549 #if defined(HAVE_PCAP_WSOCKINIT)
1550 if (pcap_wsockinit() != 0)
1551 error("Attempting to initialize Winsock failed");
1552 #elif defined(HAVE_WSOCKINIT)
1553 if (wsockinit() != 0)
1554 error("Attempting to initialize Winsock failed");
1558 * On platforms where the CPU doesn't support unaligned loads,
1559 * force unaligned accesses to abort with SIGBUS, rather than
1560 * being fixed up (slowly) by the OS kernel; on those platforms,
1561 * misaligned accesses are bugs, and we want tcpdump to crash so
1562 * that the bugs are reported.
1564 if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
1568 (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
1572 /* compatibility for old -a */
1583 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
1585 Bflag = atoi(optarg)*1024;
1587 error("invalid packet buffer size %s", optarg);
1589 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
1594 error("invalid packet count %s", optarg);
1599 #ifdef HAVE_PCAP_DUMP_FTELL64
1600 Cflag = strtoint64_t(optarg, &endp, 10);
1602 Cflag = strtol(optarg, &endp, 10);
1604 if (endp == optarg || *endp != '\0' || errno != 0
1606 error("invalid file size %s", optarg);
1608 * Will multiplying it by 1000000 overflow?
1610 #ifdef HAVE_PCAP_DUMP_FTELL64
1611 if (Cflag > INT64_T_CONSTANT(0x7fffffffffffffff) / 1000000)
1613 if (Cflag > LONG_MAX / 1000000)
1615 error("file size %s is too large", optarg);
1623 #ifdef HAVE_PCAP_FINDALLDEVS
1629 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1630 case OPTION_LIST_REMOTE_INTERFACES:
1631 remote_interfaces_source = optarg;
1644 #ifndef HAVE_LIBCRYPTO
1645 warning("crypto code not compiled in");
1647 ndo->ndo_espsecret = optarg;
1659 Gflag = atoi(optarg);
1661 error("invalid number of seconds %s", optarg);
1663 /* We will create one file initially. */
1666 /* Grab the current time for rotation use. */
1667 if ((Gflag_time = time(NULL)) == (time_t)-1) {
1668 error("%s: can't get current time: %s",
1669 __func__, pcap_strerror(errno));
1674 print_usage(stdout);
1675 exit_tcpdump(S_SUCCESS);
1686 #ifdef HAVE_PCAP_CREATE
1690 #endif /* HAVE_PCAP_CREATE */
1692 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1694 jflag = pcap_tstamp_type_name_to_val(optarg);
1696 error("invalid time stamp type %s", optarg);
1707 * _IOLBF is the same as _IOFBF in Microsoft's C
1708 * libraries; the only alternative they offer
1711 * XXX - this should really be checking for MSVC++,
1712 * not _WIN32, if, for example, MinGW has its own
1713 * C library that is more UNIX-compatible.
1715 setvbuf(stdout, NULL, _IONBF, 0);
1717 #ifdef HAVE_SETLINEBUF
1720 setvbuf(stdout, NULL, _IOLBF, 0);
1731 if (nd_have_smi_support()) {
1732 if (nd_load_smi_module(optarg, ebuf, sizeof(ebuf)) == -1)
1735 (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
1736 program_name, optarg);
1737 (void)fprintf(stderr, "(no libsmi support)\n");
1742 /* TCP-MD5 shared secret */
1743 #ifndef HAVE_LIBCRYPTO
1744 warning("crypto code not compiled in");
1746 ndo->ndo_sigsecret = optarg;
1767 ++ndo->ndo_suppress_default_print;
1770 #ifdef HAVE_PCAP_SETDIRECTION
1772 if (ascii_strcasecmp(optarg, "in") == 0)
1774 else if (ascii_strcasecmp(optarg, "out") == 0)
1776 else if (ascii_strcasecmp(optarg, "inout") == 0)
1777 Qflag = PCAP_D_INOUT;
1779 error("unknown capture direction `%s'", optarg);
1781 #endif /* HAVE_PCAP_SETDIRECTION */
1788 ndo->ndo_snaplen = (int)strtol(optarg, &end, 0);
1789 if (optarg == end || *end != '\0'
1790 || ndo->ndo_snaplen < 0 || ndo->ndo_snaplen > MAXIMUM_SNAPLEN)
1791 error("invalid snaplen %s (must be >= 0 and <= %d)",
1792 optarg, MAXIMUM_SNAPLEN);
1804 if (ascii_strcasecmp(optarg, "vat") == 0)
1805 ndo->ndo_packettype = PT_VAT;
1806 else if (ascii_strcasecmp(optarg, "wb") == 0)
1807 ndo->ndo_packettype = PT_WB;
1808 else if (ascii_strcasecmp(optarg, "rpc") == 0)
1809 ndo->ndo_packettype = PT_RPC;
1810 else if (ascii_strcasecmp(optarg, "rtp") == 0)
1811 ndo->ndo_packettype = PT_RTP;
1812 else if (ascii_strcasecmp(optarg, "rtcp") == 0)
1813 ndo->ndo_packettype = PT_RTCP;
1814 else if (ascii_strcasecmp(optarg, "snmp") == 0)
1815 ndo->ndo_packettype = PT_SNMP;
1816 else if (ascii_strcasecmp(optarg, "cnfp") == 0)
1817 ndo->ndo_packettype = PT_CNFP;
1818 else if (ascii_strcasecmp(optarg, "tftp") == 0)
1819 ndo->ndo_packettype = PT_TFTP;
1820 else if (ascii_strcasecmp(optarg, "aodv") == 0)
1821 ndo->ndo_packettype = PT_AODV;
1822 else if (ascii_strcasecmp(optarg, "carp") == 0)
1823 ndo->ndo_packettype = PT_CARP;
1824 else if (ascii_strcasecmp(optarg, "radius") == 0)
1825 ndo->ndo_packettype = PT_RADIUS;
1826 else if (ascii_strcasecmp(optarg, "zmtp1") == 0)
1827 ndo->ndo_packettype = PT_ZMTP1;
1828 else if (ascii_strcasecmp(optarg, "vxlan") == 0)
1829 ndo->ndo_packettype = PT_VXLAN;
1830 else if (ascii_strcasecmp(optarg, "pgm") == 0)
1831 ndo->ndo_packettype = PT_PGM;
1832 else if (ascii_strcasecmp(optarg, "pgm_zmtp1") == 0)
1833 ndo->ndo_packettype = PT_PGM_ZMTP1;
1834 else if (ascii_strcasecmp(optarg, "lmp") == 0)
1835 ndo->ndo_packettype = PT_LMP;
1836 else if (ascii_strcasecmp(optarg, "resp") == 0)
1837 ndo->ndo_packettype = PT_RESP;
1838 else if (ascii_strcasecmp(optarg, "ptp") == 0)
1839 ndo->ndo_packettype = PT_PTP;
1840 else if (ascii_strcasecmp(optarg, "someip") == 0)
1841 ndo->ndo_packettype = PT_SOMEIP;
1842 else if (ascii_strcasecmp(optarg, "domain") == 0)
1843 ndo->ndo_packettype = PT_DOMAIN;
1845 error("unknown packet type `%s'", optarg);
1852 #ifdef HAVE_PCAP_DUMP_FLUSH
1871 Wflag = atoi(optarg);
1873 error("invalid number of output files %s", optarg);
1874 WflagChars = getWflagChars(Wflag);
1879 ++ndo->ndo_suppress_default_print;
1884 ++ndo->ndo_suppress_default_print;
1888 yflag_dlt_name = optarg;
1890 pcap_datalink_name_to_val(yflag_dlt_name);
1892 error("invalid data link type %s", yflag_dlt_name);
1895 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
1898 /* Undocumented flag */
1899 pcap_set_parser_debug(1);
1912 ndo->ndo_packet_number = 1;
1915 case OPTION_VERSION:
1916 print_version(stdout);
1917 exit_tcpdump(S_SUCCESS);
1920 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1921 case OPTION_TSTAMP_PRECISION:
1922 ndo->ndo_tstamp_precision = tstamp_precision_from_string(optarg);
1923 if (ndo->ndo_tstamp_precision < 0)
1924 error("unsupported time stamp precision");
1928 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1929 case OPTION_IMMEDIATE_MODE:
1938 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1939 case OPTION_TSTAMP_MICRO:
1940 ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
1943 case OPTION_TSTAMP_NANO:
1944 ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_NANO;
1948 case OPTION_FP_TYPE:
1950 * Print out the type of floating-point arithmetic
1951 * we're doing; it's probably IEEE, unless somebody
1952 * tries to run this on a VAX, but the precision
1953 * may differ (e.g., it might be 32-bit, 64-bit,
1956 float_type_check(0x4e93312d);
1964 print_usage(stderr);
1965 exit_tcpdump(S_ERR_HOST_PROGRAM);
1969 #ifdef HAVE_PCAP_FINDALLDEVS
1971 show_devices_and_exit();
1973 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1974 if (remote_interfaces_source != NULL)
1975 show_remote_devices_and_exit();
1978 #if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK)
1979 /* Set default linktype DLT_LINUX_SLL2 when capturing on the "any" device */
1980 if (device != NULL &&
1981 strncmp (device, "any", strlen("any")) == 0
1983 yflag_dlt = DLT_LINUX_SLL2;
1986 switch (ndo->ndo_tflag) {
1988 case 0: /* Default */
1989 case 1: /* No time stamp */
1990 case 2: /* Unix timeval style */
1991 case 3: /* Microseconds/nanoseconds since previous packet */
1992 case 4: /* Date + Default */
1993 case 5: /* Microseconds/nanoseconds since first packet */
1996 default: /* Not supported */
1997 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
2001 if (ndo->ndo_fflag != 0 && (VFileName != NULL || RFileName != NULL))
2002 error("-f can not be used with -V or -r");
2004 if (VFileName != NULL && RFileName != NULL)
2005 error("-V and -r are mutually exclusive.");
2008 * If we're printing dissected packets to the standard output,
2009 * and either the standard output is a terminal or we're doing
2010 * "line" buffering, set the capture timeout to .1 second rather
2011 * than 1 second, as the user's probably expecting to see packets
2012 * pop up immediately shortly after they arrive.
2014 * XXX - would there be some value appropriate for all cases,
2015 * based on, say, the buffer size and packet input rate?
2017 if ((WFileName == NULL || print) && (isatty(1) || lflag))
2021 /* if run as root, prepare for chrooting */
2022 if (getuid() == 0 || geteuid() == 0) {
2023 /* future extensibility for cmd-line arguments */
2025 chroot_dir = WITH_CHROOT;
2030 /* if run as root, prepare for dropping root privileges */
2031 if (getuid() == 0 || geteuid() == 0) {
2032 /* Run with '-Z root' to restore old behaviour */
2034 username = WITH_USER;
2038 if (RFileName != NULL || VFileName != NULL) {
2040 * If RFileName is non-null, it's the pathname of a
2041 * savefile to read. If VFileName is non-null, it's
2042 * the pathname of a file containing a list of pathnames
2043 * (one per line) of savefiles to read.
2045 * In either case, we're reading a savefile, not doing
2050 * We don't need network access, so relinquish any set-UID
2051 * or set-GID privileges we have (if any).
2053 * We do *not* want set-UID privileges when opening a
2054 * trace file, as that might let the user read other
2055 * people's trace files (especially if we're set-UID
2058 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
2059 fprintf(stderr, "Warning: setgid/setuid failed !\n");
2061 if (VFileName != NULL) {
2062 if (VFileName[0] == '-' && VFileName[1] == '\0')
2065 VFile = fopen(VFileName, "r");
2068 error("Unable to open file: %s\n", pcap_strerror(errno));
2070 ret = get_next_file(VFile, VFileLine);
2072 error("Nothing in %s\n", VFileName);
2073 RFileName = VFileLine;
2076 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
2077 pd = pcap_open_offline_with_tstamp_precision(RFileName,
2078 ndo->ndo_tstamp_precision, ebuf);
2080 pd = pcap_open_offline(RFileName, ebuf);
2085 #ifdef HAVE_CAPSICUM
2086 cap_rights_init(&rights, CAP_READ);
2087 if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
2089 error("unable to limit pcap descriptor");
2092 dlt = pcap_datalink(pd);
2093 dlt_name = pcap_datalink_val_to_name(dlt);
2094 fprintf(stderr, "reading from file %s", RFileName);
2095 if (dlt_name == NULL) {
2096 fprintf(stderr, ", link-type %u", dlt);
2098 fprintf(stderr, ", link-type %s (%s)", dlt_name,
2099 pcap_datalink_val_to_description(dlt));
2101 fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2102 #ifdef DLT_LINUX_SLL2
2103 if (dlt == DLT_LINUX_SLL2)
2104 fprintf(stderr, "Warning: interface names might be incorrect\n");
2106 } else if (dflag && !device) {
2107 int dump_dlt = DLT_EN10MB;
2109 * We're dumping the compiled code without an explicit
2110 * device specification. (If a device is specified, we
2111 * definitely want to open it to use the DLT of that device.)
2112 * Either default to DLT_EN10MB with a warning, or use
2113 * the user-specified value if supplied.
2116 * If no snapshot length was specified, or a length of 0 was
2117 * specified, default to 256KB.
2119 if (ndo->ndo_snaplen == 0)
2120 ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
2122 * If a DLT was specified with the -y flag, use that instead.
2124 if (yflag_dlt != -1)
2125 dump_dlt = yflag_dlt;
2127 fprintf(stderr, "Warning: assuming Ethernet\n");
2128 pd = pcap_open_dead(dump_dlt, ndo->ndo_snaplen);
2131 * We're doing a live capture.
2133 if (device == NULL) {
2135 * No interface was specified. Pick one.
2137 #ifdef HAVE_PCAP_FINDALLDEVS
2139 * Find the list of interfaces, and pick
2140 * the first interface.
2142 if (pcap_findalldevs(&devlist, ebuf) == -1)
2144 if (devlist == NULL)
2145 error("no interfaces available for capture");
2146 device = strdup(devlist->name);
2147 pcap_freealldevs(devlist);
2148 #else /* HAVE_PCAP_FINDALLDEVS */
2150 * Use whatever interface pcap_lookupdev()
2153 device = pcap_lookupdev(ebuf);
2160 * Try to open the interface with the specified name.
2162 pd = open_interface(device, ndo, ebuf);
2165 * That failed. If we can get a list of
2166 * interfaces, and the interface name
2167 * is purely numeric, try to use it as
2168 * a 1-based index in the list of
2171 #ifdef HAVE_PCAP_FINDALLDEVS
2172 devnum = parse_interface_number(device);
2175 * It's not a number; just report
2176 * the open error and fail.
2182 * OK, it's a number; try to find the
2183 * interface with that index, and try
2186 * find_interface_by_number() exits if it
2187 * couldn't be found.
2189 device = find_interface_by_number(device, devnum);
2190 pd = open_interface(device, ndo, ebuf);
2193 #else /* HAVE_PCAP_FINDALLDEVS */
2195 * We can't get a list of interfaces; just
2199 #endif /* HAVE_PCAP_FINDALLDEVS */
2203 * Let user own process after capture device has
2207 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
2208 fprintf(stderr, "Warning: setgid/setuid failed !\n");
2210 #if !defined(HAVE_PCAP_CREATE) && defined(_WIN32)
2212 if(pcap_setbuff(pd, Bflag)==-1){
2213 error("%s", pcap_geterr(pd));
2215 #endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
2217 show_dlts_and_exit(pd, device);
2218 if (yflag_dlt >= 0) {
2219 #ifdef HAVE_PCAP_SET_DATALINK
2220 if (pcap_set_datalink(pd, yflag_dlt) < 0)
2221 error("%s", pcap_geterr(pd));
2224 * We don't actually support changing the
2225 * data link type, so we only let them
2226 * set it to what it already is.
2228 if (yflag_dlt != pcap_datalink(pd)) {
2229 error("%s is not one of the DLTs supported by this device\n",
2233 (void)fprintf(stderr, "%s: data link type %s\n",
2235 pcap_datalink_val_to_name(yflag_dlt));
2236 (void)fflush(stderr);
2238 i = pcap_snapshot(pd);
2239 if (ndo->ndo_snaplen < i) {
2240 if (ndo->ndo_snaplen != 0)
2241 warning("snaplen raised from %d to %d", ndo->ndo_snaplen, i);
2242 ndo->ndo_snaplen = i;
2243 } else if (ndo->ndo_snaplen > i) {
2244 warning("snaplen lowered from %d to %d", ndo->ndo_snaplen, i);
2245 ndo->ndo_snaplen = i;
2247 if(ndo->ndo_fflag != 0) {
2248 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
2249 warning("foreign (-f) flag used but: %s", ebuf);
2255 cmdbuf = read_infile(infile);
2257 cmdbuf = copy_argv(&argv[optind]);
2259 #ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
2260 pcap_set_optimizer_debug(dflag);
2262 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2263 error("%s", pcap_geterr(pd));
2265 bpf_dump(&fcode, dflag);
2268 pcap_freecode(&fcode);
2269 exit_tcpdump(S_SUCCESS);
2273 if (!ndo->ndo_nflag)
2274 capdns = capdns_setup();
2275 #endif /* HAVE_CASPER */
2277 init_print(ndo, localnet, netmask);
2280 (void)setsignal(SIGPIPE, cleanup);
2281 (void)setsignal(SIGTERM, cleanup);
2283 (void)setsignal(SIGINT, cleanup);
2284 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2285 (void)setsignal(SIGCHLD, child_cleanup);
2287 /* Cooperate with nohup(1) */
2289 if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
2290 (void)setsignal(SIGHUP, oldhandler);
2295 * If a user name was specified with "-Z", attempt to switch to
2296 * that user's UID. This would probably be used with sudo,
2297 * to allow tcpdump to be run in a special restricted
2298 * account (if you just want to allow users to open capture
2299 * devices, and can't just give users that permission,
2300 * you'd make tcpdump set-UID or set-GID).
2302 * Tcpdump doesn't necessarily write only to one savefile;
2303 * the general only way to allow a -Z instance to write to
2304 * savefiles as the user under whose UID it's run, rather
2305 * than as the user specified with -Z, would thus be to switch
2306 * to the original user ID before opening a capture file and
2307 * then switch back to the -Z user ID after opening the savefile.
2308 * Switching to the -Z user ID only after opening the first
2309 * savefile doesn't handle the general case.
2312 if (getuid() == 0 || geteuid() == 0) {
2313 #ifdef HAVE_LIBCAP_NG
2314 /* Initialize capng */
2315 capng_clear(CAPNG_SELECT_BOTH);
2317 DIAG_OFF_ASSIGN_ENUM
2320 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2327 DIAG_OFF_ASSIGN_ENUM
2330 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2337 DIAG_OFF_ASSIGN_ENUM
2340 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2345 capng_apply(CAPNG_SELECT_BOTH);
2346 #endif /* HAVE_LIBCAP_NG */
2347 if (username || chroot_dir)
2348 droproot(username, chroot_dir);
2353 if (pcap_setfilter(pd, &fcode) < 0)
2354 error("%s", pcap_geterr(pd));
2355 #ifdef HAVE_CAPSICUM
2356 if (RFileName == NULL && VFileName == NULL && pcap_fileno(pd) != -1) {
2357 static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
2360 * The various libpcap devices use a combination of
2361 * read (bpf), ioctl (bpf, netmap), poll (netmap)
2362 * so we add the relevant access rights.
2364 cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
2365 if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
2367 error("unable to limit pcap descriptor");
2369 if (cap_ioctls_limit(pcap_fileno(pd), cmds,
2370 sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
2371 error("unable to limit ioctls on pcap descriptor");
2376 /* Do not exceed the default PATH_MAX for files. */
2377 dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
2379 if (dumpinfo.CurrentFileName == NULL)
2380 error("malloc of dumpinfo.CurrentFileName");
2382 /* We do not need numbering for dumpfiles if Cflag isn't set. */
2384 MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
2386 MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
2388 pdd = pcap_dump_open(pd, dumpinfo.CurrentFileName);
2389 #ifdef HAVE_LIBCAP_NG
2390 /* Give up CAP_DAC_OVERRIDE capability.
2391 * Only allow it to be restored if the -C or -G flag have been
2392 * set since we may need to create more files later on.
2396 (Cflag || Gflag ? 0 : CAPNG_PERMITTED)
2400 capng_apply(CAPNG_SELECT_BOTH);
2401 #endif /* HAVE_LIBCAP_NG */
2403 error("%s", pcap_geterr(pd));
2404 #ifdef HAVE_CAPSICUM
2405 set_dumper_capsicum_rights(pdd);
2407 if (Cflag != 0 || Gflag != 0) {
2408 #ifdef HAVE_CAPSICUM
2410 * basename() and dirname() may modify their input buffer
2411 * and they do since FreeBSD 12.0, but they didn't before.
2412 * Hence use the return value only, but always assume the
2413 * input buffer has been modified and would need to be
2414 * reset before the next use.
2416 char *WFileName_copy;
2418 if ((WFileName_copy = strdup(WFileName)) == NULL) {
2419 error("Unable to allocate memory for file %s",
2422 DIAG_OFF_C11_EXTENSIONS
2423 dumpinfo.WFileName = strdup(basename(WFileName_copy));
2424 DIAG_ON_C11_EXTENSIONS
2425 if (dumpinfo.WFileName == NULL) {
2426 error("Unable to allocate memory for file %s",
2429 free(WFileName_copy);
2431 if ((WFileName_copy = strdup(WFileName)) == NULL) {
2432 error("Unable to allocate memory for file %s",
2435 DIAG_OFF_C11_EXTENSIONS
2436 char *WFileName_dirname = dirname(WFileName_copy);
2437 DIAG_ON_C11_EXTENSIONS
2438 dumpinfo.dirfd = open(WFileName_dirname,
2439 O_DIRECTORY | O_RDONLY);
2440 if (dumpinfo.dirfd < 0) {
2441 error("unable to open directory %s",
2444 free(WFileName_dirname);
2445 free(WFileName_copy);
2447 cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
2448 CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
2449 if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
2451 error("unable to limit directory rights");
2453 if (cap_fcntls_limit(dumpinfo.dirfd, CAP_FCNTL_GETFL) < 0 &&
2455 error("unable to limit dump descriptor fcntls");
2457 #else /* !HAVE_CAPSICUM */
2458 dumpinfo.WFileName = WFileName;
2460 callback = dump_packet_and_trunc;
2463 pcap_userdata = (u_char *)&dumpinfo;
2465 callback = dump_packet;
2466 dumpinfo.WFileName = WFileName;
2469 pcap_userdata = (u_char *)&dumpinfo;
2472 dlt = pcap_datalink(pd);
2473 ndo->ndo_if_printer = get_if_printer(dlt);
2476 dumpinfo.ndo = NULL;
2478 #ifdef HAVE_PCAP_DUMP_FLUSH
2480 pcap_dump_flush(pdd);
2483 dlt = pcap_datalink(pd);
2484 ndo->ndo_if_printer = get_if_printer(dlt);
2485 callback = print_packet;
2486 pcap_userdata = (u_char *)ndo;
2489 #ifdef SIGNAL_REQ_INFO
2491 * We can't get statistics when reading from a file rather
2492 * than capturing from a device.
2494 if (RFileName == NULL)
2495 (void)setsignal(SIGNAL_REQ_INFO, requestinfo);
2497 #ifdef SIGNAL_FLUSH_PCAP
2498 (void)setsignal(SIGNAL_FLUSH_PCAP, flushpcap);
2501 if (ndo->ndo_vflag > 0 && WFileName && RFileName == NULL && !print) {
2503 * When capturing to a file, if "--print" wasn't specified,
2504 *"-v" means tcpdump should, once per second,
2505 * "v"erbosely report the number of packets captured.
2506 * Except when reading from a file, because -r, -w and -v
2507 * together used to make a corner case, in which pcap_loop()
2508 * errored due to EINTR (see GH #155 for details).
2512 * https://blogs.msdn.microsoft.com/oldnewthing/20151230-00/?p=92741
2514 * suggests that this dates back to W2K.
2516 * I don't know what a "long wait" is, but we'll assume
2517 * that printing the stats could be a "long wait".
2519 CreateTimerQueueTimer(&timer_handle, NULL,
2520 verbose_stats_dump, NULL, 1000, 1000,
2521 WT_EXECUTEDEFAULT|WT_EXECUTELONGFUNCTION);
2522 setvbuf(stderr, NULL, _IONBF, 0);
2525 * Assume this is UN*X, and that it has setitimer(); that
2526 * dates back to UNIX 95.
2528 struct itimerval timer;
2529 (void)setsignal(SIGALRM, verbose_stats_dump);
2530 timer.it_interval.tv_sec = 1;
2531 timer.it_interval.tv_usec = 0;
2532 timer.it_value.tv_sec = 1;
2533 timer.it_value.tv_usec = 1;
2534 setitimer(ITIMER_REAL, &timer, NULL);
2538 if (RFileName == NULL) {
2540 * Live capture (if -V was specified, we set RFileName
2541 * to a file from the -V file). Print a message to
2542 * the standard error on UN*X.
2544 if (!ndo->ndo_vflag && !WFileName) {
2545 (void)fprintf(stderr,
2546 "%s: verbose output suppressed, use -v[v]... for full protocol decode\n",
2549 (void)fprintf(stderr, "%s: ", program_name);
2550 dlt = pcap_datalink(pd);
2551 dlt_name = pcap_datalink_val_to_name(dlt);
2552 (void)fprintf(stderr, "listening on %s", device);
2553 if (dlt_name == NULL) {
2554 (void)fprintf(stderr, ", link-type %u", dlt);
2556 (void)fprintf(stderr, ", link-type %s (%s)", dlt_name,
2557 pcap_datalink_val_to_description(dlt));
2559 (void)fprintf(stderr, ", snapshot length %d bytes\n", ndo->ndo_snaplen);
2560 (void)fflush(stderr);
2563 #ifdef HAVE_CAPSICUM
2564 cansandbox = (VFileName == NULL && zflag == NULL &&
2565 ndo->ndo_espsecret == NULL);
2567 cansandbox = (cansandbox && (ndo->ndo_nflag || capdns != NULL));
2569 cansandbox = (cansandbox && ndo->ndo_nflag);
2570 #endif /* HAVE_CASPER */
2571 cansandbox = (cansandbox && (pcap_fileno(pd) != -1 ||
2572 RFileName != NULL));
2574 if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
2575 error("unable to enter the capability mode");
2576 #endif /* HAVE_CAPSICUM */
2579 status = pcap_loop(pd, cnt, callback, pcap_userdata);
2580 if (WFileName == NULL) {
2582 * We're printing packets. Flush the printed output,
2583 * so it doesn't get intermingled with error output.
2587 * We got interrupted, so perhaps we didn't
2588 * manage to finish a line we were printing.
2589 * Print an extra newline, just in case.
2593 (void)fflush(stdout);
2597 * We got interrupted. If we are reading multiple
2598 * files (via -V) set these so that we stop.
2607 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
2608 program_name, pcap_geterr(pd));
2610 if (RFileName == NULL) {
2612 * We're doing a live capture. Report the capture
2618 if (VFileName != NULL) {
2619 ret = get_next_file(VFile, VFileLine);
2623 RFileName = VFileLine;
2624 pd = pcap_open_offline(RFileName, ebuf);
2627 #ifdef HAVE_CAPSICUM
2628 cap_rights_init(&rights, CAP_READ);
2629 if (cap_rights_limit(fileno(pcap_file(pd)),
2630 &rights) < 0 && errno != ENOSYS) {
2631 error("unable to limit pcap descriptor");
2634 new_dlt = pcap_datalink(pd);
2635 if (new_dlt != dlt) {
2637 * The new file has a different
2638 * link-layer header type from the
2641 if (WFileName != NULL) {
2643 * We're writing raw packets
2644 * that match the filter to
2645 * a pcap file. pcap files
2646 * don't support multiple
2647 * different link-layer
2648 * header types, so we fail
2651 error("%s: new dlt does not match original", RFileName);
2655 * We're printing the decoded packets;
2656 * switch to the new DLT.
2658 * To do that, we need to change
2659 * the printer, change the DLT name,
2660 * and recompile the filter with
2664 ndo->ndo_if_printer = get_if_printer(dlt);
2665 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2666 error("%s", pcap_geterr(pd));
2670 * Set the filter on the new file.
2672 if (pcap_setfilter(pd, &fcode) < 0)
2673 error("%s", pcap_geterr(pd));
2676 * Report the new file.
2678 dlt_name = pcap_datalink_val_to_name(dlt);
2679 fprintf(stderr, "reading from file %s", RFileName);
2680 if (dlt_name == NULL) {
2681 fprintf(stderr, ", link-type %u", dlt);
2683 fprintf(stderr, ", link-type %s (%s)",
2685 pcap_datalink_val_to_description(dlt));
2687 fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2691 while (ret != NULL);
2693 if (count_mode && RFileName != NULL)
2694 fprintf(stdout, "%u packet%s\n", packets_captured,
2695 PLURAL_SUFFIX(packets_captured));
2698 pcap_freecode(&fcode);
2699 exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS);
2706 (*setsignal (int sig, void (*func)(int)))(int)
2709 return (signal(sig, func));
2711 struct sigaction old, new;
2713 memset(&new, 0, sizeof(new));
2714 new.sa_handler = func;
2715 if ((sig == SIGCHLD)
2716 # ifdef SIGNAL_REQ_INFO
2717 || (sig == SIGNAL_REQ_INFO)
2719 # ifdef SIGNAL_FLUSH_PCAP
2720 || (sig == SIGNAL_FLUSH_PCAP)
2723 new.sa_flags = SA_RESTART;
2724 if (sigaction(sig, &new, &old) < 0)
2726 return (old.sa_handler);
2730 /* make a clean exit on interrupts */
2732 cleanup(int signo _U_)
2735 if (timer_handle != INVALID_HANDLE_VALUE) {
2736 DeleteTimerQueueTimer(NULL, timer_handle, NULL);
2737 CloseHandle(timer_handle);
2738 timer_handle = INVALID_HANDLE_VALUE;
2741 struct itimerval timer;
2743 timer.it_interval.tv_sec = 0;
2744 timer.it_interval.tv_usec = 0;
2745 timer.it_value.tv_sec = 0;
2746 timer.it_value.tv_usec = 0;
2747 setitimer(ITIMER_REAL, &timer, NULL);
2750 #ifdef HAVE_PCAP_BREAKLOOP
2752 * We have "pcap_breakloop()"; use it, so that we do as little
2753 * as possible in the signal handler (it's probably not safe
2754 * to do anything with standard I/O streams in a signal handler -
2755 * the ANSI C standard doesn't say it is).
2760 * We don't have "pcap_breakloop()"; this isn't safe, but
2761 * it's the best we can do. Print the summary if we're
2762 * not reading from a savefile - i.e., if we're doing a
2763 * live capture - and exit.
2765 if (pd != NULL && pcap_file(pd) == NULL) {
2767 * We got interrupted, so perhaps we didn't
2768 * manage to finish a line we were printing.
2769 * Print an extra newline, just in case.
2772 (void)fflush(stdout);
2775 exit_tcpdump(S_SUCCESS);
2780 On windows, we do not use a fork, so we do not care less about
2781 waiting a child processes to die
2783 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2785 child_cleanup(int signo _U_)
2789 #endif /* HAVE_FORK && HAVE_VFORK */
2794 struct pcap_stat stats;
2797 * Older versions of libpcap didn't set ps_ifdrop on some
2798 * platforms; initialize it to 0 to handle that.
2800 stats.ps_ifdrop = 0;
2801 if (pcap_stats(pd, &stats) < 0) {
2802 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
2808 fprintf(stderr, "%s: ", program_name);
2810 (void)fprintf(stderr, "%u packet%s captured", packets_captured,
2811 PLURAL_SUFFIX(packets_captured));
2813 fputs(", ", stderr);
2816 (void)fprintf(stderr, "%u packet%s received by filter", stats.ps_recv,
2817 PLURAL_SUFFIX(stats.ps_recv));
2819 fputs(", ", stderr);
2822 (void)fprintf(stderr, "%u packet%s dropped by kernel", stats.ps_drop,
2823 PLURAL_SUFFIX(stats.ps_drop));
2824 if (stats.ps_ifdrop != 0) {
2826 fputs(", ", stderr);
2829 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
2830 stats.ps_ifdrop, PLURAL_SUFFIX(stats.ps_ifdrop));
2836 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2838 #define fork_subprocess() fork()
2840 #define fork_subprocess() vfork()
2843 compress_savefile(const char *filename)
2847 child = fork_subprocess();
2850 "compress_savefile: fork failed: %s\n",
2851 pcap_strerror(errno));
2855 /* Parent process. */
2861 * Set to lowest priority so that this doesn't disturb the capture.
2864 setpriority(PRIO_PROCESS, 0, NZERO - 1);
2866 setpriority(PRIO_PROCESS, 0, 19);
2868 if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
2870 "compress_savefile: execlp(%s, %s) failed: %s\n",
2873 pcap_strerror(errno));
2875 exit(S_ERR_HOST_PROGRAM);
2877 _exit(S_ERR_HOST_PROGRAM);
2880 #else /* HAVE_FORK && HAVE_VFORK */
2882 compress_savefile(const char *filename)
2885 "compress_savefile failed. Functionality not implemented under your system\n");
2887 #endif /* HAVE_FORK && HAVE_VFORK */
2890 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2892 struct dump_info *dump_info;
2898 dump_info = (struct dump_info *)user;
2901 * XXX - this won't force the file to rotate on the specified time
2902 * boundary, but it will rotate on the first packet received after the
2903 * specified Gflag number of seconds. Note: if a Gflag time boundary
2904 * and a Cflag size boundary coincide, the time rotation will occur
2905 * first thereby cancelling the Cflag boundary (since the file should
2909 /* Check if it is time to rotate */
2912 /* Get the current time */
2913 if ((t = time(NULL)) == (time_t)-1) {
2914 error("%s: can't get current_time: %s",
2915 __func__, pcap_strerror(errno));
2919 /* If the time is greater than the specified window, rotate */
2920 if (t - Gflag_time >= Gflag) {
2921 #ifdef HAVE_CAPSICUM
2926 /* Update the Gflag_time */
2928 /* Update Gflag_count */
2931 * Close the current file and open a new one.
2933 pcap_dump_close(dump_info->pdd);
2936 * Compress the file we just closed, if the user asked for it
2939 compress_savefile(dump_info->CurrentFileName);
2942 * Check to see if we've exceeded the Wflag (when
2945 if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
2946 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
2949 exit_tcpdump(S_SUCCESS);
2952 if (dump_info->CurrentFileName != NULL)
2953 free(dump_info->CurrentFileName);
2954 /* Allocate space for max filename + \0. */
2955 dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2956 if (dump_info->CurrentFileName == NULL)
2957 error("dump_packet_and_trunc: malloc");
2959 * Gflag was set otherwise we wouldn't be here. Reset the count
2960 * so multiple files would end with 1,2,3 in the filename.
2961 * The counting is handled with the -C flow after this.
2966 * This is always the first file in the Cflag
2968 * We also don't need numbering if Cflag is not set.
2971 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
2974 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
2976 #ifdef HAVE_LIBCAP_NG
2977 capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2978 capng_apply(CAPNG_SELECT_BOTH);
2979 #endif /* HAVE_LIBCAP_NG */
2980 #ifdef HAVE_CAPSICUM
2981 fd = openat(dump_info->dirfd,
2982 dump_info->CurrentFileName,
2983 O_CREAT | O_WRONLY | O_TRUNC, 0644);
2985 error("unable to open file %s",
2986 dump_info->CurrentFileName);
2988 fp = fdopen(fd, "w");
2990 error("unable to fdopen file %s",
2991 dump_info->CurrentFileName);
2993 dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
2994 #else /* !HAVE_CAPSICUM */
2995 dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2997 #ifdef HAVE_LIBCAP_NG
2998 capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2999 capng_apply(CAPNG_SELECT_BOTH);
3000 #endif /* HAVE_LIBCAP_NG */
3001 if (dump_info->pdd == NULL)
3002 error("%s", pcap_geterr(pd));
3003 #ifdef HAVE_CAPSICUM
3004 set_dumper_capsicum_rights(dump_info->pdd);
3010 * XXX - this won't prevent capture files from getting
3011 * larger than Cflag - the last packet written to the
3012 * file could put it over Cflag.
3015 #ifdef HAVE_PCAP_DUMP_FTELL64
3016 int64_t size = pcap_dump_ftell64(dump_info->pdd);
3019 * XXX - this only handles a Cflag value > 2^31-1 on
3020 * LP64 platforms; to handle ILP32 (32-bit UN*X and
3021 * Windows) or LLP64 (64-bit Windows) would require
3022 * a version of libpcap with pcap_dump_ftell64().
3024 long size = pcap_dump_ftell(dump_info->pdd);
3028 error("ftell fails on output file");
3030 #ifdef HAVE_CAPSICUM
3036 * Close the current file and open a new one.
3038 pcap_dump_close(dump_info->pdd);
3041 * Compress the file we just closed, if the user
3045 compress_savefile(dump_info->CurrentFileName);
3049 if (Cflag_count >= Wflag)
3052 if (dump_info->CurrentFileName != NULL)
3053 free(dump_info->CurrentFileName);
3054 dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
3055 if (dump_info->CurrentFileName == NULL)
3056 error("%s: malloc", __func__);
3057 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
3058 #ifdef HAVE_LIBCAP_NG
3059 capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3060 capng_apply(CAPNG_SELECT_BOTH);
3061 #endif /* HAVE_LIBCAP_NG */
3062 #ifdef HAVE_CAPSICUM
3063 fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
3064 O_CREAT | O_WRONLY | O_TRUNC, 0644);
3066 error("unable to open file %s",
3067 dump_info->CurrentFileName);
3069 fp = fdopen(fd, "w");
3071 error("unable to fdopen file %s",
3072 dump_info->CurrentFileName);
3074 dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
3075 #else /* !HAVE_CAPSICUM */
3076 dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
3078 #ifdef HAVE_LIBCAP_NG
3079 capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3080 capng_apply(CAPNG_SELECT_BOTH);
3081 #endif /* HAVE_LIBCAP_NG */
3082 if (dump_info->pdd == NULL)
3083 error("%s", pcap_geterr(pd));
3084 #ifdef HAVE_CAPSICUM
3085 set_dumper_capsicum_rights(dump_info->pdd);
3090 pcap_dump((u_char *)dump_info->pdd, h, sp);
3091 #ifdef HAVE_PCAP_DUMP_FLUSH
3093 pcap_dump_flush(dump_info->pdd);
3096 if (dump_info->ndo != NULL)
3097 pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3105 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3107 struct dump_info *dump_info;
3113 dump_info = (struct dump_info *)user;
3115 pcap_dump((u_char *)dump_info->pdd, h, sp);
3116 #ifdef HAVE_PCAP_DUMP_FLUSH
3118 pcap_dump_flush(dump_info->pdd);
3121 if (dump_info->ndo != NULL)
3122 pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3130 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3137 pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
3144 #ifdef SIGNAL_REQ_INFO
3146 requestinfo(int signo _U_)
3155 #ifdef SIGNAL_FLUSH_PCAP
3157 flushpcap(int signo _U_)
3160 pcap_dump_flush(pdd);
3165 print_packets_captured (void)
3167 static u_int prev_packets_captured, first = 1;
3169 if (infodelay == 0 && (first || packets_captured != prev_packets_captured)) {
3170 fprintf(stderr, "Got %u\r", packets_captured);
3172 prev_packets_captured = packets_captured;
3177 * Called once each second in verbose mode while dumping to file
3180 static void CALLBACK verbose_stats_dump(PVOID param _U_,
3181 BOOLEAN timer_fired _U_)
3183 print_packets_captured();
3186 static void verbose_stats_dump(int sig _U_)
3188 print_packets_captured();
3192 DIAG_OFF_DEPRECATION
3194 print_version(FILE *f)
3196 #ifndef HAVE_PCAP_LIB_VERSION
3197 #ifdef HAVE_PCAP_VERSION
3198 extern char pcap_version[];
3199 #else /* HAVE_PCAP_VERSION */
3200 static char pcap_version[] = "unknown";
3201 #endif /* HAVE_PCAP_VERSION */
3202 #endif /* HAVE_PCAP_LIB_VERSION */
3203 const char *smi_version_string;
3205 (void)fprintf(f, "%s version " PACKAGE_VERSION "\n", program_name);
3206 #ifdef HAVE_PCAP_LIB_VERSION
3207 (void)fprintf(f, "%s\n", pcap_lib_version());
3208 #else /* HAVE_PCAP_LIB_VERSION */
3209 (void)fprintf(f, "libpcap version %s\n", pcap_version);
3210 #endif /* HAVE_PCAP_LIB_VERSION */
3212 #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
3213 (void)fprintf (f, "%s\n", SSLeay_version(SSLEAY_VERSION));
3216 smi_version_string = nd_smi_version_string();
3217 if (smi_version_string != NULL)
3218 (void)fprintf (f, "SMI-library: %s\n", smi_version_string);
3220 #if defined(__SANITIZE_ADDRESS__)
3221 (void)fprintf (f, "Compiled with AddressSanitizer/GCC.\n");
3222 #elif defined(__has_feature)
3223 # if __has_feature(address_sanitizer)
3224 (void)fprintf (f, "Compiled with AddressSanitizer/Clang.\n");
3225 # elif __has_feature(memory_sanitizer)
3226 (void)fprintf (f, "Compiled with MemorySanitizer/Clang.\n");
3228 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
3233 print_usage(FILE *f)
3237 "Usage: %s [-Abd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ] [--count]\n", program_name);
3239 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
3241 "\t\t[ -i interface ]" IMMEDIATE_MODE_USAGE j_FLAG_USAGE "\n");
3242 #ifdef HAVE_PCAP_FINDALLDEVS_EX
3244 "\t\t" LIST_REMOTE_INTERFACES_USAGE "\n");
3248 "\t\t" m_FLAG_USAGE "\n");
3251 "\t\t[ -M secret ] [ --number ] [ --print ]" Q_FLAG_USAGE "\n");
3253 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ --version ]\n");
3255 "\t\t[ -V file ] [ -w file ] [ -W filecount ] [ -y datalinktype ]\n");
3256 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
3258 "\t\t[ --time-stamp-precision precision ] [ --micro ] [ --nano ]\n");
3261 "\t\t[ -z postrotate-command ] [ -Z user ] [ expression ]\n");