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 static const char copyright[] _U_ =
30 "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
31 The Regents of the University of California. All rights reserved.\n";
32 static const char rcsid[] _U_ =
33 "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.216.2.10 2004/03/17 19:47:48 guy Exp $ (LBL)";
37 * tcpdump - monitor tcp/ip traffic on an ethernet.
39 * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
40 * Mercilessly hacked and occasionally improved since then via the
41 * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
48 #include <tcpdump-stdinc.h>
53 extern int strcasecmp (const char *__s1, const char *__s2);
65 #include "interface.h"
66 #include "addrtoname.h"
68 #include "setsignal.h"
69 #include "gmt2local.h"
70 #include "pcap-missing.h"
72 int dflag; /* print filter code */
73 int eflag; /* print ethernet header */
74 int fflag; /* don't translate "foreign" IP address */
75 int Lflag; /* list available data link types and exit */
76 int nflag; /* leave addresses as numbers */
77 int Nflag; /* remove domains from printed host names */
78 int Oflag = 1; /* run filter code optimizer */
79 int pflag; /* don't go promiscuous */
80 int qflag; /* quick (shorter) output */
81 int Rflag = 1; /* print sequence # field in AH/ESP*/
82 int sflag = 0; /* use the libsmi to translate OIDs */
83 int Sflag; /* print raw TCP sequence numbers */
84 int tflag = 1; /* print packet arrival time */
85 int Uflag = 0; /* "unbuffered" output of dump files */
86 int uflag = 0; /* Print undecoded NFS handles */
87 int vflag; /* verbose */
88 int xflag; /* print packet in hex */
89 int Xflag; /* print packet in ascii as well as hex */
90 off_t Cflag = 0; /* rotate dump files after this many bytes */
91 int Aflag = 0; /* print packet only in ascii observing LF, CR, TAB, SPACE */
92 int dlt = -1; /* if != -1, ask libpcap for the DLT it names */
94 const char *dlt_name = NULL;
96 char *espsecret = NULL; /* ESP secret key */
100 static int infodelay;
101 static int infoprint;
105 int32_t thiszone; /* seconds offset from gmt to local time */
108 static RETSIGTYPE cleanup(int);
109 static void usage(void) __attribute__((noreturn));
110 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
112 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
113 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
114 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
117 RETSIGTYPE requestinfo(int);
120 static void info(int);
121 static u_int packets_captured;
123 /* Length of saved portion of packet. */
124 int snaplen = DEFAULT_SNAPLEN;
126 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
133 static struct printer printers[] = {
134 { arcnet_if_print, DLT_ARCNET },
135 #ifdef DLT_ARCNET_LINUX
136 { arcnet_linux_if_print, DLT_ARCNET_LINUX },
138 { ether_if_print, DLT_EN10MB },
139 { token_if_print, DLT_IEEE802 },
141 { lane_if_print, DLT_LANE8023 },
144 { cip_if_print, DLT_CIP },
147 { cip_if_print, DLT_ATM_CLIP },
149 { sl_if_print, DLT_SLIP },
150 #ifdef DLT_SLIP_BSDOS
151 { sl_bsdos_if_print, DLT_SLIP_BSDOS },
153 { ppp_if_print, DLT_PPP },
155 { ppp_bsdos_if_print, DLT_PPP_BSDOS },
157 { fddi_if_print, DLT_FDDI },
158 { null_if_print, DLT_NULL },
160 { null_if_print, DLT_LOOP },
162 { raw_if_print, DLT_RAW },
163 { atm_if_print, DLT_ATM_RFC1483 },
165 { chdlc_if_print, DLT_C_HDLC },
168 { chdlc_if_print, DLT_HDLC },
170 #ifdef DLT_PPP_SERIAL
171 { ppp_hdlc_if_print, DLT_PPP_SERIAL },
174 { pppoe_if_print, DLT_PPP_ETHER },
177 { sll_if_print, DLT_LINUX_SLL },
179 #ifdef DLT_IEEE802_11
180 { ieee802_11_if_print, DLT_IEEE802_11},
183 { ltalk_if_print, DLT_LTALK },
186 { pflog_if_print, DLT_PFLOG },
189 { fr_if_print, DLT_FR },
192 { fr_if_print, DLT_FRELAY },
195 { sunatm_if_print, DLT_SUNATM },
197 #ifdef DLT_IP_OVER_FC
198 { ipfc_if_print, DLT_IP_OVER_FC },
200 #ifdef DLT_PRISM_HEADER
201 { prism_if_print, DLT_PRISM_HEADER },
203 #ifdef DLT_IEEE802_11_RADIO
204 { ieee802_11_radio_if_print, DLT_IEEE802_11_RADIO },
207 { enc_if_print, DLT_ENC },
209 #ifdef DLT_APPLE_IP_OVER_IEEE1394
210 { ap1394_if_print, DLT_APPLE_IP_OVER_IEEE1394 },
216 lookup_printer(int type)
220 for (p = printers; p->f; ++p)
245 show_dlts_and_exit(pcap_t *pd)
249 const char *dlt_name;
251 n_dlts = pcap_list_datalinks(pd, &dlts);
253 error("%s", pcap_geterr(pd));
254 else if (n_dlts == 0 || !dlts)
255 error("No data link types.");
257 (void) fprintf(stderr, "Data link types (use option -y to set):\n");
259 while (--n_dlts >= 0) {
260 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
261 if (dlt_name != NULL) {
262 (void) fprintf(stderr, " %s (%s)", dlt_name,
263 pcap_datalink_val_to_description(dlts[n_dlts]));
266 * OK, does tcpdump handle that type?
268 if (lookup_printer(dlts[n_dlts]) == NULL)
269 (void) fprintf(stderr, " (not supported)");
272 (void) fprintf(stderr, " DLT %d (not supported)\n",
281 * Set up flags that might or might not be supported depending on the
282 * version of libpcap we're using.
286 #define B_FLAG_USAGE " [ -B size ]"
292 #ifdef HAVE_PCAP_FINDALLDEVS
298 #ifdef HAVE_PCAP_DUMP_FLUSH
305 main(int argc, char **argv)
307 register int cnt, op, i;
308 bpf_u_int32 localnet, netmask;
309 register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
310 pcap_handler callback;
312 struct bpf_program fcode;
314 RETSIGTYPE (*oldhandler)(int);
316 struct print_info printinfo;
317 struct dump_info dumpinfo;
318 u_char *pcap_userdata;
319 char ebuf[PCAP_ERRBUF_SIZE];
320 #ifdef HAVE_PCAP_FINDALLDEVS
321 pcap_if_t *devpointer;
326 u_int UserBufferSize = 1000000;
327 if(wsockinit() != 0) return 1;
335 if ((cp = strrchr(argv[0], '/')) != NULL)
336 program_name = cp + 1;
338 program_name = argv[0];
340 if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
349 (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:nNOpqr:Rs:StT:u" U_FLAG "vw:xXy:Y")) != -1)
353 /* compatibility for old -a */
364 UserBufferSize = atoi(optarg)*1024;
365 if (UserBufferSize < 0)
366 error("invalid packet buffer size %s", optarg);
373 error("invalid packet count %s", optarg);
377 Cflag = atoi(optarg) * 1000000;
379 error("invalid file size %s", optarg);
386 #ifdef HAVE_PCAP_FINDALLDEVS
388 if (pcap_findalldevs(&devpointer, ebuf) < 0)
391 for (i = 0; devpointer != 0; i++) {
392 printf("%d.%s", i+1, devpointer->name);
393 if (devpointer->description != NULL)
394 printf(" (%s)", devpointer->description);
396 devpointer = devpointer->next;
400 #endif /* HAVE_PCAP_FINDALLDEVS */
411 #ifndef HAVE_LIBCRYPTO
412 warning("crypto code not compiled in");
426 if (optarg[0] == '0' && optarg[1] == 0)
427 error("Invalid adapter index");
429 #ifdef HAVE_PCAP_FINDALLDEVS
431 * If the argument is a number, treat it as
432 * an index into the list of adapters, as
433 * printed by "tcpdump -D".
435 * This should be OK on UNIX systems, as interfaces
436 * shouldn't have names that begin with digits.
437 * It can be useful on Windows, where more than
438 * one interface can have the same name.
440 if ((devnum = atoi(optarg)) != 0) {
442 error("Invalid adapter index");
444 if (pcap_findalldevs(&devpointer, ebuf) < 0)
447 for (i = 0; i < devnum-1; i++){
448 devpointer = devpointer->next;
449 if (devpointer == NULL)
450 error("Invalid adapter index");
453 device = devpointer->name;
456 #endif /* HAVE_PCAP_FINDALLDEVS */
463 * _IOLBF is the same as _IOFBF in Microsoft's C
464 * libraries; the only alternative they offer
467 * XXX - this should really be checking for MSVC++,
468 * not WIN32, if, for example, MinGW has its own
469 * C library that is more UNIX-compatible.
471 setvbuf(stdout, NULL, _IONBF, 0);
473 #ifdef HAVE_SETLINEBUF
476 setvbuf(stdout, NULL, _IOLBF, 0);
491 if (smiLoadModule(optarg) == 0) {
492 error("could not load MIB module %s", optarg);
496 (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
497 program_name, optarg);
498 (void)fprintf(stderr, "(no libsmi support)\n");
525 snaplen = strtol(optarg, &end, 0);
526 if (optarg == end || *end != '\0'
527 || snaplen < 0 || snaplen > 65535)
528 error("invalid snaplen %s", optarg);
529 else if (snaplen == 0)
543 if (strcasecmp(optarg, "vat") == 0)
545 else if (strcasecmp(optarg, "wb") == 0)
547 else if (strcasecmp(optarg, "rpc") == 0)
549 else if (strcasecmp(optarg, "rtp") == 0)
551 else if (strcasecmp(optarg, "rtcp") == 0)
552 packettype = PT_RTCP;
553 else if (strcasecmp(optarg, "snmp") == 0)
554 packettype = PT_SNMP;
555 else if (strcasecmp(optarg, "cnfp") == 0)
556 packettype = PT_CNFP;
557 else if (strcasecmp(optarg, "tftp") == 0)
558 packettype = PT_TFTP;
559 else if (strcasecmp(optarg, "aodv") == 0)
560 packettype = PT_AODV;
562 error("unknown packet type `%s'", optarg);
569 #ifdef HAVE_PCAP_DUMP_FLUSH
594 dlt = pcap_datalink_name_to_val(dlt_name);
596 error("invalid data link type %s", dlt_name);
599 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
602 /* Undocumented flag */
603 #ifdef HAVE_PCAP_DEBUG
604 extern int pcap_debug;
619 thiszone = gmt2local(0);
621 if (RFileName != NULL) {
623 const char *dlt_name;
627 * We don't need network access, so relinquish any set-UID
628 * or set-GID privileges we have (if any).
630 * We do *not* want set-UID privileges when opening a
631 * trace file, as that might let the user read other
632 * people's trace files (especially if we're set-UID
637 pd = pcap_open_offline(RFileName, ebuf);
640 dlt = pcap_datalink(pd);
641 dlt_name = pcap_datalink_val_to_name(dlt);
642 if (dlt_name == NULL) {
643 fprintf(stderr, "reading from file %s, link-type %u\n",
647 "reading from file %s, link-type %s (%s)\n",
649 pcap_datalink_val_to_description(dlt));
654 error("-f and -r options are incompatible");
656 if (device == NULL) {
657 device = pcap_lookupdev(ebuf);
662 if(IsTextUnicode(device,
663 wcslen((short*)device), // Device always ends with a double \0, so this way to determine its
664 // length should be always valid
667 fprintf(stderr, "%s: listening on %ws\n", program_name, device);
671 fprintf(stderr, "%s: listening on %s\n", program_name, device);
677 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
683 if(UserBufferSize != 1000000)
684 if(pcap_setbuff(pd, UserBufferSize)==-1){
685 error("%s", pcap_geterr(pd));
689 show_dlts_and_exit(pd);
691 #ifdef HAVE_PCAP_SET_DATALINK
692 if (pcap_set_datalink(pd, dlt) < 0)
693 error("%s", pcap_geterr(pd));
696 * We don't actually support changing the
697 * data link type, so we only let them
698 * set it to what it already is.
700 if (dlt != pcap_datalink(pd)) {
701 error("%s is not one of the DLTs supported by this device\n",
705 (void)fprintf(stderr, "%s: data link type %s\n",
706 program_name, dlt_name);
707 (void)fflush(stderr);
709 i = pcap_snapshot(pd);
711 warning("snaplen raised from %d to %d", snaplen, i);
714 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
720 * Let user own process after socket has been opened.
727 cmdbuf = read_infile(infile);
729 cmdbuf = copy_argv(&argv[optind]);
731 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
732 error("%s", pcap_geterr(pd));
734 bpf_dump(&fcode, dflag);
738 init_addrtoname(localnet, netmask);
741 (void)setsignal(SIGPIPE, cleanup);
743 (void)setsignal(SIGTERM, cleanup);
744 (void)setsignal(SIGINT, cleanup);
745 /* Cooperate with nohup(1) */
747 if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
748 (void)setsignal(SIGHUP, oldhandler);
751 if (pcap_setfilter(pd, &fcode) < 0)
752 error("%s", pcap_geterr(pd));
754 pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
756 error("%s", pcap_geterr(pd));
758 callback = dump_packet_and_trunc;
759 dumpinfo.WFileName = WFileName;
762 pcap_userdata = (u_char *)&dumpinfo;
764 callback = dump_packet;
765 pcap_userdata = (u_char *)p;
768 type = pcap_datalink(pd);
769 printinfo.printer = lookup_printer(type);
770 if (printinfo.printer == NULL) {
771 dlt_name = pcap_datalink_val_to_name(type);
772 if (dlt_name != NULL)
773 error("unsupported data link type %s", dlt_name);
775 error("unsupported data link type %d", type);
777 callback = print_packet;
778 pcap_userdata = (u_char *)&printinfo;
781 (void)setsignal(SIGINFO, requestinfo);
784 if (RFileName == NULL) {
786 const char *dlt_name;
788 if (!vflag && !WFileName) {
789 (void)fprintf(stderr,
790 "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
793 (void)fprintf(stderr, "%s: ", program_name);
794 dlt = pcap_datalink(pd);
795 dlt_name = pcap_datalink_val_to_name(dlt);
796 if (dlt_name == NULL) {
797 (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
798 device, dlt, snaplen);
800 (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
802 pcap_datalink_val_to_description(dlt), snaplen);
804 (void)fflush(stderr);
807 status = pcap_loop(pd, cnt, callback, pcap_userdata);
808 if (WFileName == NULL) {
810 * We're printing packets. Flush the printed output,
811 * so it doesn't get intermingled with error output.
815 * We got interrupted, so perhaps we didn't
816 * manage to finish a line we were printing.
817 * Print an extra newline, just in case.
821 (void)fflush(stdout);
827 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
828 program_name, pcap_geterr(pd));
830 if (RFileName == NULL) {
832 * We're doing a live capture. Report the capture
838 exit(status == -1 ? 1 : 0);
841 /* make a clean exit on interrupts */
843 cleanup(int signo _U_)
845 #ifdef HAVE_PCAP_BREAKLOOP
847 * We have "pcap_breakloop()"; use it, so that we do as little
848 * as possible in the signal handler (it's probably not safe
849 * to do anything with standard I/O streams in a signal handler -
850 * the ANSI C standard doesn't say it is).
855 * We don't have "pcap_breakloop()"; this isn't safe, but
856 * it's the best we can do. Print the summary if we're
857 * not reading from a savefile - i.e., if we're doing a
858 * live capture - and exit.
860 if (pd != NULL && pcap_file(pd) == NULL) {
862 * We got interrupted, so perhaps we didn't
863 * manage to finish a line we were printing.
864 * Print an extra newline, just in case.
867 (void)fflush(stdout);
875 info(register int verbose)
877 struct pcap_stat stat;
879 if (pcap_stats(pd, &stat) < 0) {
880 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
885 fprintf(stderr, "%s: ", program_name);
887 (void)fprintf(stderr, "%u packets captured", packets_captured);
892 (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
897 (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
906 for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
915 swebitoa(unsigned int n, char *s)
921 s[i++] = n % 10 + '0';
922 } while ((n /= 10) > 0);
929 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
931 struct dump_info *dump_info;
939 dump_info = (struct dump_info *)user;
942 * XXX - this won't prevent capture files from getting
943 * larger than Cflag - the last packet written to the
944 * file could put it over Cflag.
946 if (ftell((FILE *)dump_info->p) > Cflag) {
948 * Close the current file and open a new one.
950 pcap_dump_close(dump_info->p);
952 error("too many output files");
953 name = (char *) malloc(strlen(dump_info->WFileName) + 4);
955 error("dump_packet_and_trunc: malloc");
956 strcpy(name, dump_info->WFileName);
957 swebitoa(cnt, name + strlen(dump_info->WFileName));
959 dump_info->p = pcap_dump_open(dump_info->pd, name);
961 if (dump_info->p == NULL)
962 error("%s", pcap_geterr(pd));
965 pcap_dump((u_char *)dump_info->p, h, sp);
966 #ifdef HAVE_PCAP_DUMP_FLUSH
968 pcap_dump_flush(dump_info->p);
977 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
983 pcap_dump(user, h, sp);
984 #ifdef HAVE_PCAP_DUMP_FLUSH
986 pcap_dump_flush((pcap_dumper_t *)user);
995 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
997 struct print_info *print_info;
1005 print_info = (struct print_info *)user;
1008 * Some printers want to check that they're not walking off the
1009 * end of the packet.
1010 * Rather than pass it all the way down, we set this global.
1012 snapend = sp + h->caplen;
1014 hdrlen = (*print_info->printer)(h, sp);
1017 * Print the raw packet data.
1021 * Include the link-layer header.
1023 default_print(sp, h->caplen);
1026 * Don't include the link-layer header - and if
1027 * we have nothing past the link-layer header,
1030 if (h->caplen > hdrlen)
1031 default_print(sp + hdrlen,
1032 h->caplen - hdrlen);
1045 * XXX - there should really be libpcap calls to get the version
1046 * number as a string (the string would be generated from #defines
1047 * at run time, so that it's not generated from string constants
1048 * in the library, as, on many UNIX systems, those constants would
1049 * be statically linked into the application executable image, and
1050 * would thus reflect the version of libpcap on the system on
1051 * which the application was *linked*, not the system on which it's
1054 * That routine should be documented, unlike the "version[]"
1055 * string, so that UNIX vendors providing their own libpcaps
1056 * don't omit it (as a couple of vendors have...).
1058 * Packet.dll should perhaps also export a routine to return the
1059 * version number of the Packet.dll code, to supply the
1060 * "Wpcap_version" information on Windows.
1062 char WDversion[]="current-cvs.tcpdump.org";
1063 char version[]="current-cvs.tcpdump.org";
1064 char pcap_version[]="current-cvs.tcpdump.org";
1065 char Wpcap_version[]="3.0 alpha";
1069 * By default, print the specified data out in hex.
1072 default_print(register const u_char *bp, register u_int length)
1074 ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1078 RETSIGTYPE requestinfo(int signo _U_)
1090 extern char version[];
1091 #ifndef HAVE_PCAP_LIB_VERSION
1092 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1093 extern char pcap_version[];
1094 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1095 static char pcap_version[] = "unknown";
1096 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1097 #endif /* HAVE_PCAP_LIB_VERSION */
1099 #ifdef HAVE_PCAP_LIB_VERSION
1100 (void)fprintf(stderr, "%s version %s\n", program_name, version);
1101 (void)fprintf(stderr, "%s\n", pcap_lib_version());
1102 #else /* HAVE_PCAP_LIB_VERSION */
1104 (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1105 (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1107 (void)fprintf(stderr, "%s version %s\n", program_name, version);
1108 (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1110 #endif /* HAVE_PCAP_LIB_VERSION */
1111 (void)fprintf(stderr,
1112 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
1113 (void)fprintf(stderr,
1114 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
1115 (void)fprintf(stderr,
1116 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n");
1117 (void)fprintf(stderr,
1118 "\t\t[ expression ]\n");