The Tcpdump Group git mirrors - tcpdump/blob - tcpdump.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * Support for splitting captures into multiple files with a maximum
  22  * file size:
  23  *
  24  * Copyright (c) 2001
  25  *      Seth Webster <swebster@sst.ll.mit.edu>
  26  */
  27
  28 #ifndef lint
  29 static const char copyright[] _U_ =
  30     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  31 The Regents of the University of California.  All rights reserved.\n";
  32 static const char rcsid[] _U_ =
  33     "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.242 2004-04-07 08:14:10 guy Exp $ (LBL)";
  34 #endif
  35
  36 /*
  37  * tcpdump - monitor tcp/ip traffic on an ethernet.
  38  *
  39  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
  40  * Mercilessly hacked and occasionally improved since then via the
  41  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
  42  */
  43
  44 #ifdef HAVE_CONFIG_H
  45 #include "config.h"
  46 #endif
  47
  48 #include <tcpdump-stdinc.h>
  49
  50 #ifdef WIN32
  51 #include "getopt.h"
  52 #include "w32_fzs.h"
  53 extern int strcasecmp (const char *__s1, const char *__s2);
  54 extern int SIZE_BUF;
  55 #define off_t long
  56 #define uint UINT
  57 #endif /* WIN32 */
  58
  59 #ifdef HAVE_SMI_H
  60 #include <smi.h>
  61 #endif
  62
  63 #include <pcap.h>
  64 #include <signal.h>
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #ifndef WIN32
  69 #include <pwd.h>
  70 #include <grp.h>
  71 #include <errno.h>
  72 #endif /* WIN32 */
  73
  74 #include "netdissect.h"
  75 #include "interface.h"
  76 #include "addrtoname.h"
  77 #include "machdep.h"
  78 #include "setsignal.h"
  79 #include "gmt2local.h"
  80 #include "pcap-missing.h"
  81
  82 netdissect_options Gndo;
  83 netdissect_options *gndo = &Gndo;
  84
  85 /*
  86  * Define the maximum number of files for the -C flag, and how many
  87  * characters can be added to a filename for the -C flag (which
  88  * should be enough to handle MAX_CFLAG - 1).
  89  */
  90 #define MAX_CFLAG       1000000
  91 #define MAX_CFLAG_CHARS 6
  92
  93 int Lflag;          /* list available data link types and exit */
  94
  95 static int infodelay;
  96 static int infoprint;
  97
  98 char *program_name;
  99
 100 int32_t thiszone;               /* seconds offset from gmt to local time */
 101
 102 /* Forwards */
 103 static RETSIGTYPE cleanup(int);
 104 static void usage(void) __attribute__((noreturn));
 105 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
 106
 107 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 108 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 109 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 110 static void droproot(const char *, const char *);
 111 static void ndo_error(netdissect_options *ndo, const char *fmt, ...);
 112 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 113
 114 #ifdef SIGINFO
 115 RETSIGTYPE requestinfo(int);
 116 #endif
 117
 118 #if defined(USE_WIN32_MM_TIMER)
 119   #include <MMsystem.h>
 120   static UINT timer_id;
 121   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
 122 #elif defined(HAVE_ALARM)
 123   static void verbose_stats_dump(int sig);
 124 #endif
 125
 126 static void info(int);
 127 static u_int packets_captured;
 128
 129 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
 130
 131 struct printer {
 132         if_printer f;
 133         int type;
 134 };
 135
 136 static struct printer printers[] = {
 137         { arcnet_if_print,      DLT_ARCNET },
 138 #ifdef DLT_ARCNET_LINUX
 139         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 140 #endif
 141         { ether_if_print,       DLT_EN10MB },
 142         { token_if_print,       DLT_IEEE802 },
 143 #ifdef DLT_LANE8023
 144         { lane_if_print,        DLT_LANE8023 },
 145 #endif
 146 #ifdef DLT_CIP
 147         { cip_if_print,         DLT_CIP },
 148 #endif
 149 #ifdef DLT_ATM_CLIP
 150         { cip_if_print,         DLT_ATM_CLIP },
 151 #endif
 152         { sl_if_print,          DLT_SLIP },
 153 #ifdef DLT_SLIP_BSDOS
 154         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 155 #endif
 156         { ppp_if_print,         DLT_PPP },
 157 #ifdef DLT_PPP_BSDOS
 158         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 159 #endif
 160         { fddi_if_print,        DLT_FDDI },
 161         { null_if_print,        DLT_NULL },
 162 #ifdef DLT_LOOP
 163         { null_if_print,        DLT_LOOP },
 164 #endif
 165         { raw_if_print,         DLT_RAW },
 166         { atm_if_print,         DLT_ATM_RFC1483 },
 167 #ifdef DLT_C_HDLC
 168         { chdlc_if_print,       DLT_C_HDLC },
 169 #endif
 170 #ifdef DLT_HDLC
 171         { chdlc_if_print,       DLT_HDLC },
 172 #endif
 173 #ifdef DLT_PPP_SERIAL
 174         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 175 #endif
 176 #ifdef DLT_PPP_ETHER
 177         { pppoe_if_print,       DLT_PPP_ETHER },
 178 #endif
 179 #ifdef DLT_LINUX_SLL
 180         { sll_if_print,         DLT_LINUX_SLL },
 181 #endif
 182 #ifdef DLT_IEEE802_11
 183         { ieee802_11_if_print,  DLT_IEEE802_11},
 184 #endif
 185 #ifdef DLT_LTALK
 186         { ltalk_if_print,       DLT_LTALK },
 187 #endif
 188 #ifdef DLT_PFLOG
 189         { pflog_if_print,       DLT_PFLOG },
 190 #endif
 191 #ifdef DLT_FR
 192         { fr_if_print,          DLT_FR },
 193 #endif
 194 #ifdef DLT_FRELAY
 195         { fr_if_print,          DLT_FRELAY },
 196 #endif
 197 #ifdef DLT_SUNATM
 198         { sunatm_if_print,      DLT_SUNATM },
 199 #endif
 200 #ifdef DLT_IP_OVER_FC
 201         { ipfc_if_print,        DLT_IP_OVER_FC },
 202 #endif
 203 #ifdef DLT_PRISM_HEADER
 204         { prism_if_print,       DLT_PRISM_HEADER },
 205 #endif
 206 #ifdef DLT_IEEE802_11_RADIO
 207         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 208 #endif
 209 #ifdef DLT_ENC
 210         { enc_if_print,         DLT_ENC },
 211 #endif
 212 #ifdef DLT_SYMANTEC_FIREWALL
 213         { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
 214 #endif
 215 #ifdef DLT_APPLE_IP_OVER_IEEE1394
 216         { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
 217 #endif
 218         { NULL,                 0 },
 219 };
 220
 221 static if_printer
 222 lookup_printer(int type)
 223 {
 224         struct printer *p;
 225
 226         for (p = printers; p->f; ++p)
 227                 if (type == p->type)
 228                         return p->f;
 229
 230         return NULL;
 231         /* NOTREACHED */
 232 }
 233
 234 static pcap_t *pd;
 235
 236 extern int optind;
 237 extern int opterr;
 238 extern char *optarg;
 239
 240 struct print_info {
 241         if_printer printer;
 242 };
 243
 244 struct dump_info {
 245         char    *WFileName;
 246         pcap_t  *pd;
 247         pcap_dumper_t *p;
 248 };
 249
 250 static void
 251 show_dlts_and_exit(pcap_t *pd)
 252 {
 253         int n_dlts;
 254         int *dlts = 0;
 255         const char *dlt_name;
 256
 257         n_dlts = pcap_list_datalinks(pd, &dlts);
 258         if (n_dlts < 0)
 259                 error("%s", pcap_geterr(pd));
 260         else if (n_dlts == 0 || !dlts)
 261                 error("No data link types.");
 262
 263         (void) fprintf(stderr, "Data link types (use option -y to set):\n");
 264
 265         while (--n_dlts >= 0) {
 266                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 267                 if (dlt_name != NULL) {
 268                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 269                             pcap_datalink_val_to_description(dlts[n_dlts]));
 270
 271                         /*
 272                          * OK, does tcpdump handle that type?
 273                          */
 274                         if (lookup_printer(dlts[n_dlts]) == NULL)
 275                                 (void) fprintf(stderr, " (not supported)");
 276                         putchar('\n');
 277                 } else {
 278                         (void) fprintf(stderr, "  DLT %d (not supported)\n",
 279                             dlts[n_dlts]);
 280                 }
 281         }
 282         free(dlts);
 283         exit(0);
 284 }
 285
 286 /*
 287  * Set up flags that might or might not be supported depending on the
 288  * version of libpcap we're using.
 289  */
 290 #ifdef WIN32
 291 #define B_FLAG          "B:"
 292 #define B_FLAG_USAGE    " [ -B size ]"
 293 #else /* WIN32 */
 294 #define B_FLAG
 295 #define B_FLAG_USAGE
 296 #endif /* WIN32 */
 297
 298 #ifdef HAVE_PCAP_FINDALLDEVS
 299 #ifndef HAVE_PCAP_IF_T
 300 #undef HAVE_PCAP_FINDALLDEVS
 301 #endif
 302 #endif
 303
 304 #ifdef HAVE_PCAP_FINDALLDEVS
 305 #define D_FLAG  "D"
 306 #else
 307 #define D_FLAG
 308 #endif
 309
 310 #ifdef HAVE_PCAP_DUMP_FLUSH
 311 #define U_FLAG  "U"
 312 #else
 313 #define U_FLAG
 314 #endif
 315
 316 #ifndef WIN32
 317 /* Drop root privileges and chroot if necessary */
 318 static void
 319 droproot(const char *username, const char *chroot_dir)
 320 {
 321         struct passwd *pw = NULL;
 322
 323         if (chroot_dir && !username) {
 324                 fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
 325                 exit(1);
 326         }
 327
 328         pw = getpwnam(username);
 329         if (pw) {
 330                 if (chroot_dir) {
 331                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
 332                                 fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
 333                                     chroot_dir, pcap_strerror(errno));
 334                                 exit(1);
 335                         }
 336                 }
 337                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 338                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
 339                         fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
 340                             username,
 341                             (unsigned long)pw->pw_uid,
 342                             (unsigned long)pw->pw_gid,
 343                             pcap_strerror(errno));
 344                         exit(1);
 345                 }
 346         }
 347         else {
 348                 fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
 349                     username);
 350                 exit(1);
 351         }
 352 }
 353 #endif /* WIN32 */
 354
 355 static int
 356 getWflagChars(int x)
 357 {
 358         int c = 0;
 359
 360         x -= 1;
 361         while (x > 0) {
 362                 c += 1;
 363                 x /= 10;
 364         }
 365
 366         return c;
 367 }
 368
 369
 370 static void
 371 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 372 {
 373         if (cnt == 0 && max_chars == 0)
 374                 strcpy(buffer, orig_name);
 375         else
 376                 sprintf(buffer, "%s%0*d", orig_name, max_chars, cnt);
 377 }
 378
 379 static int tcpdump_printf(netdissect_options *ndo _U_,
 380                           const char *fmt, ...)
 381 {
 382
 383   va_list args;
 384   int ret;
 385
 386   va_start(args, fmt);
 387   ret=vfprintf(stdout, fmt, args);
 388   va_end(args);
 389
 390   return ret;
 391 };
 392
 393 int
 394 main(int argc, char **argv)
 395 {
 396         register int cnt, op, i;
 397         bpf_u_int32 localnet, netmask;
 398         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName, *WFileNameAlt;
 399         pcap_handler callback;
 400         int type;
 401         struct bpf_program fcode;
 402 #ifndef WIN32
 403         RETSIGTYPE (*oldhandler)(int);
 404 #endif
 405         struct print_info printinfo;
 406         struct dump_info dumpinfo;
 407         u_char *pcap_userdata;
 408         char ebuf[PCAP_ERRBUF_SIZE];
 409         char *username = NULL;
 410         char *chroot_dir = NULL;
 411 #ifdef HAVE_PCAP_FINDALLDEVS
 412         pcap_if_t *devpointer;
 413         int devnum;
 414 #endif
 415         int status;
 416 #ifdef WIN32
 417         u_int UserBufferSize = 1000000;
 418         if(wsockinit() != 0) return 1;
 419 #endif /* WIN32 */
 420
 421         gndo->ndo_Oflag=1;
 422         gndo->ndo_Rflag=1;
 423         gndo->ndo_tflag=1;
 424         gndo->ndo_dlt=-1;
 425         gndo->ndo_printf=tcpdump_printf;
 426         gndo->ndo_error=ndo_error;
 427         gndo->ndo_warning=ndo_warning;
 428         gndo->ndo_snaplen = DEFAULT_SNAPLEN;
 429
 430         cnt = -1;
 431         device = NULL;
 432         infile = NULL;
 433         RFileName = NULL;
 434         WFileName = NULL;
 435         if ((cp = strrchr(argv[0], '/')) != NULL)
 436                 program_name = cp + 1;
 437         else
 438                 program_name = argv[0];
 439
 440         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 441                 error("%s", ebuf);
 442
 443 #ifdef LIBSMI
 444         smiInit("tcpdump");
 445 #endif
 446
 447         opterr = 0;
 448         while (
 449             (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:YZ:")) != -1)
 450                 switch (op) {
 451
 452                 case 'a':
 453                         /* compatibility for old -a */
 454                         break;
 455
 456                 case 'A':
 457                         ++xflag;
 458                         ++Xflag;
 459                         ++Aflag;
 460                         break;
 461
 462 #ifdef WIN32
 463                 case 'B':
 464                         UserBufferSize = atoi(optarg)*1024;
 465                         if (UserBufferSize < 0)
 466                                 error("invalid packet buffer size %s", optarg);
 467                         break;
 468 #endif /* WIN32 */
 469
 470                 case 'c':
 471                         cnt = atoi(optarg);
 472                         if (cnt <= 0)
 473                                 error("invalid packet count %s", optarg);
 474                         break;
 475
 476                 case 'C':
 477                         Cflag = atoi(optarg) * 1000000;
 478                         if (Cflag < 0)
 479                                 error("invalid file size %s", optarg);
 480                         break;
 481
 482                 case 'd':
 483                         ++dflag;
 484                         break;
 485
 486 #ifdef HAVE_PCAP_FINDALLDEVS
 487                 case 'D':
 488                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 489                                 error("%s", ebuf);
 490                         else {
 491                                 for (i = 0; devpointer != 0; i++) {
 492                                         printf("%d.%s", i+1, devpointer->name);
 493                                         if (devpointer->description != NULL)
 494                                                 printf(" (%s)", devpointer->description);
 495                                         printf("\n");
 496                                         devpointer = devpointer->next;
 497                                 }
 498                         }
 499                         return 0;
 500 #endif /* HAVE_PCAP_FINDALLDEVS */
 501
 502                 case 'L':
 503                         Lflag++;
 504                         break;
 505
 506                 case 'e':
 507                         ++eflag;
 508                         break;
 509
 510                 case 'E':
 511 #ifndef HAVE_LIBCRYPTO
 512                         warning("crypto code not compiled in");
 513 #endif
 514                         gndo->ndo_espsecret = optarg;
 515                         break;
 516
 517                 case 'f':
 518                         ++fflag;
 519                         break;
 520
 521                 case 'F':
 522                         infile = optarg;
 523                         break;
 524
 525                 case 'i':
 526                         if (optarg[0] == '0' && optarg[1] == 0)
 527                                 error("Invalid adapter index");
 528
 529 #ifdef HAVE_PCAP_FINDALLDEVS
 530                         /*
 531                          * If the argument is a number, treat it as
 532                          * an index into the list of adapters, as
 533                          * printed by "tcpdump -D".
 534                          *
 535                          * This should be OK on UNIX systems, as interfaces
 536                          * shouldn't have names that begin with digits.
 537                          * It can be useful on Windows, where more than
 538                          * one interface can have the same name.
 539                          */
 540                         if ((devnum = atoi(optarg)) != 0) {
 541                                 if (devnum < 0)
 542                                         error("Invalid adapter index");
 543
 544                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 545                                         error("%s", ebuf);
 546                                 else {
 547                                         for (i = 0; i < devnum-1; i++){
 548                                                 devpointer = devpointer->next;
 549                                                 if (devpointer == NULL)
 550                                                         error("Invalid adapter index");
 551                                         }
 552                                 }
 553                                 device = devpointer->name;
 554                                 break;
 555                         }
 556 #endif /* HAVE_PCAP_FINDALLDEVS */
 557                         device = optarg;
 558                         break;
 559
 560                 case 'l':
 561 #ifdef WIN32
 562                         /*
 563                          * _IOLBF is the same as _IOFBF in Microsoft's C
 564                          * libraries; the only alternative they offer
 565                          * is _IONBF.
 566                          *
 567                          * XXX - this should really be checking for MSVC++,
 568                          * not WIN32, if, for example, MinGW has its own
 569                          * C library that is more UNIX-compatible.
 570                          */
 571                         setvbuf(stdout, NULL, _IONBF, 0);
 572 #else /* WIN32 */
 573 #ifdef HAVE_SETLINEBUF
 574                         setlinebuf(stdout);
 575 #else
 576                         setvbuf(stdout, NULL, _IOLBF, 0);
 577 #endif
 578 #endif /* WIN32 */
 579                         break;
 580
 581                 case 'n':
 582                         ++nflag;
 583                         break;
 584
 585                 case 'N':
 586                         ++Nflag;
 587                         break;
 588
 589                 case 'm':
 590 #ifdef LIBSMI
 591                         if (smiLoadModule(optarg) == 0) {
 592                                 error("could not load MIB module %s", optarg);
 593                         }
 594                         sflag = 1;
 595 #else
 596                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 597                                       program_name, optarg);
 598                         (void)fprintf(stderr, "(no libsmi support)\n");
 599 #endif
 600                         break;
 601
 602                 case 'M':
 603                         /* TCP-MD5 shared secret */
 604 #ifndef HAVE_LIBCRYPTO
 605                         warning("crypto code not compiled in");
 606 #endif
 607                         tcpmd5secret = optarg;
 608                         break;
 609
 610                 case 'O':
 611                         Oflag = 0;
 612                         break;
 613
 614                 case 'p':
 615                         ++pflag;
 616                         break;
 617
 618                 case 'q':
 619                         ++qflag;
 620                         break;
 621
 622                 case 'r':
 623                         RFileName = optarg;
 624                         break;
 625
 626                 case 'R':
 627                         Rflag = 0;
 628                         break;
 629
 630                 case 's': {
 631                         char *end;
 632
 633                         snaplen = strtol(optarg, &end, 0);
 634                         if (optarg == end || *end != '\0'
 635                             || snaplen < 0 || snaplen > 65535)
 636                                 error("invalid snaplen %s", optarg);
 637                         else if (snaplen == 0)
 638                                 snaplen = 65535;
 639                         break;
 640                 }
 641
 642                 case 'S':
 643                         ++Sflag;
 644                         break;
 645
 646                 case 't':
 647                         --tflag;
 648                         break;
 649
 650                 case 'T':
 651                         if (strcasecmp(optarg, "vat") == 0)
 652                                 packettype = PT_VAT;
 653                         else if (strcasecmp(optarg, "wb") == 0)
 654                                 packettype = PT_WB;
 655                         else if (strcasecmp(optarg, "rpc") == 0)
 656                                 packettype = PT_RPC;
 657                         else if (strcasecmp(optarg, "rtp") == 0)
 658                                 packettype = PT_RTP;
 659                         else if (strcasecmp(optarg, "rtcp") == 0)
 660                                 packettype = PT_RTCP;
 661                         else if (strcasecmp(optarg, "snmp") == 0)
 662                                 packettype = PT_SNMP;
 663                         else if (strcasecmp(optarg, "cnfp") == 0)
 664                                 packettype = PT_CNFP;
 665                         else if (strcasecmp(optarg, "tftp") == 0)
 666                                 packettype = PT_TFTP;
 667                         else if (strcasecmp(optarg, "aodv") == 0)
 668                                 packettype = PT_AODV;
 669                         else
 670                                 error("unknown packet type `%s'", optarg);
 671                         break;
 672
 673                 case 'u':
 674                         ++uflag;
 675                         break;
 676
 677 #ifdef HAVE_PCAP_DUMP_FLUSH
 678                 case 'U':
 679                         ++Uflag;
 680                         break;
 681 #endif
 682
 683                 case 'v':
 684                         ++vflag;
 685                         break;
 686
 687                 case 'w':
 688                         WFileName = optarg;
 689                         break;
 690
 691                 case 'W':
 692                         Wflag = atoi(optarg);
 693                         if (Wflag < 0)
 694                                 error("invalid number of output files %s", optarg);
 695                         WflagChars = getWflagChars(Wflag);
 696                         break;
 697
 698                 case 'x':
 699                         ++xflag;
 700                         break;
 701
 702                 case 'X':
 703                         ++xflag;
 704                         ++Xflag;
 705                         break;
 706
 707                 case 'y':
 708                         gndo->ndo_dltname = optarg;
 709                         gndo->ndo_dlt =
 710                           pcap_datalink_name_to_val(gndo->ndo_dltname);
 711                         if (gndo->ndo_dlt < 0)
 712                                 error("invalid data link type %s", gndo->ndo_dltname);
 713                         break;
 714
 715 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 716                 case 'Y':
 717                         {
 718                         /* Undocumented flag */
 719 #ifdef HAVE_PCAP_DEBUG
 720                         extern int pcap_debug;
 721                         pcap_debug = 1;
 722 #else
 723                         extern int yydebug;
 724                         yydebug = 1;
 725 #endif
 726                         }
 727                         break;
 728 #endif
 729                 case 'Z':
 730                         if (optarg) {
 731                                 username = strdup(optarg);
 732                         }
 733                         else {
 734                                 usage();
 735                                 /* NOTREACHED */
 736                         }
 737                         break;
 738
 739                 default:
 740                         usage();
 741                         /* NOTREACHED */
 742                 }
 743
 744         if (tflag > 0)
 745                 thiszone = gmt2local(0);
 746
 747 #ifdef WITH_CHROOT
 748         /* if run as root, prepare for chrooting */
 749         if (getuid() == 0 || geteuid() == 0) {
 750                 /* future extensibility for cmd-line arguments */
 751                 if (!chroot_dir)
 752                         chroot_dir = WITH_CHROOT;
 753         }
 754 #endif
 755
 756 #ifdef WITH_USER
 757         /* if run as root, prepare for dropping root privileges */
 758         if (getuid() == 0 || geteuid() == 0) {
 759                 /* Run with '-Z root' to restore old behaviour */
 760                 if (!username)
 761                         username = WITH_USER;
 762         }
 763 #endif
 764
 765         if (RFileName != NULL) {
 766                 int dlt;
 767                 const char *dlt_name;
 768
 769 #ifndef WIN32
 770                 /*
 771                  * We don't need network access, so relinquish any set-UID
 772                  * or set-GID privileges we have (if any).
 773                  *
 774                  * We do *not* want set-UID privileges when opening a
 775                  * trace file, as that might let the user read other
 776                  * people's trace files (especially if we're set-UID
 777                  * root).
 778                  */
 779                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
 780                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
 781 #endif /* WIN32 */
 782                 pd = pcap_open_offline(RFileName, ebuf);
 783                 if (pd == NULL)
 784                         error("%s", ebuf);
 785                 dlt = pcap_datalink(pd);
 786                 dlt_name = pcap_datalink_val_to_name(dlt);
 787                 if (dlt_name == NULL) {
 788                         fprintf(stderr, "reading from file %s, link-type %u\n",
 789                             RFileName, dlt);
 790                 } else {
 791                         fprintf(stderr,
 792                             "reading from file %s, link-type %s (%s)\n",
 793                             RFileName, dlt_name,
 794                             pcap_datalink_val_to_description(dlt));
 795                 }
 796                 localnet = 0;
 797                 netmask = 0;
 798                 if (fflag != 0)
 799                         error("-f and -r options are incompatible");
 800         } else {
 801                 if (device == NULL) {
 802                         device = pcap_lookupdev(ebuf);
 803                         if (device == NULL)
 804                                 error("%s", ebuf);
 805                 }
 806 #ifdef WIN32
 807                 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
 808                 {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
 809                         fprintf(stderr, "%s: listening on %ws\n", program_name, device);
 810                 }
 811                 else
 812                 {
 813                         fprintf(stderr, "%s: listening on %s\n", program_name, device);
 814                 }
 815
 816                 fflush(stderr);
 817 #endif /* WIN32 */
 818                 *ebuf = '\0';
 819                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
 820                 if (pd == NULL)
 821                         error("%s", ebuf);
 822                 else if (*ebuf)
 823                         warning("%s", ebuf);
 824                 /*
 825                  * Let user own process after socket has been opened.
 826                  */
 827 #ifndef WIN32
 828                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
 829                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
 830 #endif /* WIN32 */
 831 #ifdef WIN32
 832                 if(UserBufferSize != 1000000)
 833                         if(pcap_setbuff(pd, UserBufferSize)==-1){
 834                                 error("%s", pcap_geterr(pd));
 835                         }
 836 #endif /* WIN32 */
 837                 if (Lflag)
 838                         show_dlts_and_exit(pd);
 839                 if (gndo->ndo_dlt >= 0) {
 840 #ifdef HAVE_PCAP_SET_DATALINK
 841                         if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
 842                                 error("%s", pcap_geterr(pd));
 843 #else
 844                         /*
 845                          * We don't actually support changing the
 846                          * data link type, so we only let them
 847                          * set it to what it already is.
 848                          */
 849                         if (gndo->ndo_dlt != pcap_datalink(pd)) {
 850                                 error("%s is not one of the DLTs supported by this device\n",
 851                                       gndo->ndo_dltname);
 852                         }
 853 #endif
 854                         (void)fprintf(stderr, "%s: data link type %s\n",
 855                                       program_name, gndo->ndo_dltname);
 856                         (void)fflush(stderr);
 857                 }
 858                 i = pcap_snapshot(pd);
 859                 if (snaplen < i) {
 860                         warning("snaplen raised from %d to %d", snaplen, i);
 861                         snaplen = i;
 862                 }
 863                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 864                         localnet = 0;
 865                         netmask = 0;
 866                         warning("%s", ebuf);
 867                 }
 868         }
 869         if (infile)
 870                 cmdbuf = read_infile(infile);
 871         else
 872                 cmdbuf = copy_argv(&argv[optind]);
 873
 874         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 875                 error("%s", pcap_geterr(pd));
 876         if (dflag) {
 877                 bpf_dump(&fcode, dflag);
 878                 pcap_close(pd);
 879                 exit(0);
 880         }
 881         init_addrtoname(localnet, netmask);
 882
 883 #ifndef WIN32
 884         (void)setsignal(SIGPIPE, cleanup);
 885 #endif /* WIN32 */
 886         (void)setsignal(SIGTERM, cleanup);
 887         (void)setsignal(SIGINT, cleanup);
 888         /* Cooperate with nohup(1) */
 889 #ifndef WIN32
 890         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
 891                 (void)setsignal(SIGHUP, oldhandler);
 892 #endif /* WIN32 */
 893
 894         if (pcap_setfilter(pd, &fcode) < 0)
 895                 error("%s", pcap_geterr(pd));
 896         if (WFileName) {
 897                 pcap_dumper_t *p;
 898
 899                 WFileNameAlt = (char *)malloc(strlen(WFileName) + MAX_CFLAG_CHARS + 1);
 900                 if (WFileNameAlt == NULL)
 901                         error("malloc of WFileNameAlt");
 902                 MakeFilename(WFileNameAlt, WFileName, 0, WflagChars);
 903                 p = pcap_dump_open(pd, WFileNameAlt);
 904                 if (p == NULL)
 905                         error("%s", pcap_geterr(pd));
 906                 if (Cflag != 0) {
 907                         callback = dump_packet_and_trunc;
 908                         dumpinfo.WFileName = WFileName;
 909                         dumpinfo.pd = pd;
 910                         dumpinfo.p = p;
 911                         pcap_userdata = (u_char *)&dumpinfo;
 912                 } else {
 913                         callback = dump_packet;
 914                         pcap_userdata = (u_char *)p;
 915                 }
 916         } else {
 917                 type = pcap_datalink(pd);
 918                 printinfo.printer = lookup_printer(type);
 919                 if (printinfo.printer == NULL) {
 920                         gndo->ndo_dltname = pcap_datalink_val_to_name(type);
 921                         if (gndo->ndo_dltname != NULL)
 922                                 error("unsupported data link type %s",
 923                                       gndo->ndo_dltname);
 924                         else
 925                                 error("unsupported data link type %d", type);
 926                 }
 927                 callback = print_packet;
 928                 pcap_userdata = (u_char *)&printinfo;
 929         }
 930 #ifndef WIN32
 931         /*
 932          * We cannot do this earlier, because we want to be able to open
 933          * the file (if done) for writing before giving up permissions.
 934          */
 935         if (getuid() == 0 || geteuid() == 0) {
 936                 if (username || chroot_dir)
 937                         droproot(username, chroot_dir);
 938         }
 939 #endif /* WIN32 */
 940 #ifdef SIGINFO
 941         (void)setsignal(SIGINFO, requestinfo);
 942 #endif
 943
 944         if (vflag > 0 && WFileName) {
 945                 /*
 946                  * When capturing to a file, "-v" means tcpdump should,
 947                  * every 10 secodns, "v"erbosely report the number of
 948                  * packets captured.
 949                  */
 950 #ifdef USE_WIN32_MM_TIMER
 951                 /* call verbose_stats_dump() each 1000 +/-100msec */
 952                 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
 953                 setvbuf(stderr, NULL, _IONBF, 0);
 954 #elif defined(HAVE_ALARM)
 955                 (void)setsignal(SIGALRM, verbose_stats_dump);
 956                 alarm(1);
 957 #endif
 958         }
 959
 960 #ifndef WIN32
 961         if (RFileName == NULL) {
 962                 int dlt;
 963                 const char *dlt_name;
 964
 965                 if (!vflag && !WFileName) {
 966                         (void)fprintf(stderr,
 967                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
 968                             program_name);
 969                 } else
 970                         (void)fprintf(stderr, "%s: ", program_name);
 971                 dlt = pcap_datalink(pd);
 972                 dlt_name = pcap_datalink_val_to_name(dlt);
 973                 if (dlt_name == NULL) {
 974                         (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
 975                             device, dlt, snaplen);
 976                 } else {
 977                         (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
 978                             device, dlt_name,
 979                             pcap_datalink_val_to_description(dlt), snaplen);
 980                 }
 981                 (void)fflush(stderr);
 982         }
 983 #endif /* WIN32 */
 984         status = pcap_loop(pd, cnt, callback, pcap_userdata);
 985         if (WFileName == NULL) {
 986                 /*
 987                  * We're printing packets.  Flush the printed output,
 988                  * so it doesn't get intermingled with error output.
 989                  */
 990                 if (status == -2) {
 991                         /*
 992                          * We got interrupted, so perhaps we didn't
 993                          * manage to finish a line we were printing.
 994                          * Print an extra newline, just in case.
 995                          */
 996                         putchar('\n');
 997                 }
 998                 (void)fflush(stdout);
 999         }
1000         if (status == -1) {
1001                 /*
1002                  * Error.  Report it.
1003                  */
1004                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
1005                     program_name, pcap_geterr(pd));
1006         }
1007         if (RFileName == NULL) {
1008                 /*
1009                  * We're doing a live capture.  Report the capture
1010                  * statistics.
1011                  */
1012                 info(1);
1013         }
1014         pcap_close(pd);
1015         exit(status == -1 ? 1 : 0);
1016 }
1017
1018 /* make a clean exit on interrupts */
1019 static RETSIGTYPE
1020 cleanup(int signo _U_)
1021 {
1022 #ifdef USE_WIN32_MM_TIMER
1023         if (timer_id)
1024                 timeKillEvent(timer_id);
1025         timer_id = 0;
1026 #elif defined(HAVE_ALARM)
1027         alarm(0);
1028 #endif
1029
1030 #ifdef HAVE_PCAP_BREAKLOOP
1031         /*
1032          * We have "pcap_breakloop()"; use it, so that we do as little
1033          * as possible in the signal handler (it's probably not safe
1034          * to do anything with standard I/O streams in a signal handler -
1035          * the ANSI C standard doesn't say it is).
1036          */
1037         pcap_breakloop(pd);
1038 #else
1039         /*
1040          * We don't have "pcap_breakloop()"; this isn't safe, but
1041          * it's the best we can do.  Print the summary if we're
1042          * not reading from a savefile - i.e., if we're doing a
1043          * live capture - and exit.
1044          */
1045         if (pd != NULL && pcap_file(pd) == NULL) {
1046                 /*
1047                  * We got interrupted, so perhaps we didn't
1048                  * manage to finish a line we were printing.
1049                  * Print an extra newline, just in case.
1050                  */
1051                 putchar('\n');
1052                 (void)fflush(stdout);
1053                 info(1);
1054         }
1055         exit(0);
1056 #endif
1057 }
1058
1059 static void
1060 info(register int verbose)
1061 {
1062         struct pcap_stat stat;
1063
1064         if (pcap_stats(pd, &stat) < 0) {
1065                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1066                 return;
1067         }
1068
1069         if (!verbose)
1070                 fprintf(stderr, "%s: ", program_name);
1071
1072         (void)fprintf(stderr, "%u packets captured", packets_captured);
1073         if (!verbose)
1074                 fputs(", ", stderr);
1075         else
1076                 putc('\n', stderr);
1077         (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
1078         if (!verbose)
1079                 fputs(", ", stderr);
1080         else
1081                 putc('\n', stderr);
1082         (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
1083         infoprint = 0;
1084 }
1085
1086 static void
1087 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1088 {
1089         struct dump_info *dump_info;
1090         char *name;
1091
1092         ++packets_captured;
1093
1094         ++infodelay;
1095
1096         dump_info = (struct dump_info *)user;
1097
1098         /*
1099          * XXX - this won't prevent capture files from getting
1100          * larger than Cflag - the last packet written to the
1101          * file could put it over Cflag.
1102          */
1103         if (ftell((FILE *)dump_info->p) > Cflag) {
1104                 /*
1105                  * Close the current file and open a new one.
1106                  */
1107                 pcap_dump_close(dump_info->p);
1108                 Cflag_count++;
1109                 if (Wflag > 0) {
1110                         if (Cflag_count >= Wflag)
1111                                 Cflag_count = 0;
1112                 } else {
1113                         if (Cflag_count >= MAX_CFLAG)
1114                                 error("too many output files");
1115                 }
1116                 name = (char *)malloc(strlen(dump_info->WFileName) + MAX_CFLAG_CHARS + 1);
1117                 if (name == NULL)
1118                         error("dump_packet_and_trunc: malloc");
1119                 MakeFilename(name, dump_info->WFileName, Cflag_count, WflagChars);
1120                 dump_info->p = pcap_dump_open(dump_info->pd, name);
1121                 free(name);
1122                 if (dump_info->p == NULL)
1123                         error("%s", pcap_geterr(pd));
1124         }
1125
1126         pcap_dump((u_char *)dump_info->p, h, sp);
1127 #ifdef HAVE_PCAP_DUMP_FLUSH
1128         if (Uflag)
1129                 pcap_dump_flush(dump_info->p);
1130 #endif
1131
1132         --infodelay;
1133         if (infoprint)
1134                 info(0);
1135 }
1136
1137 static void
1138 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1139 {
1140         ++packets_captured;
1141
1142         ++infodelay;
1143
1144         pcap_dump(user, h, sp);
1145 #ifdef HAVE_PCAP_DUMP_FLUSH
1146         if (Uflag)
1147                 pcap_dump_flush((pcap_dumper_t *)user);
1148 #endif
1149
1150         --infodelay;
1151         if (infoprint)
1152                 info(0);
1153 }
1154
1155 static void
1156 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1157 {
1158         struct print_info *print_info;
1159         u_int hdrlen;
1160
1161         ++packets_captured;
1162
1163         ++infodelay;
1164         ts_print(&h->ts);
1165
1166         print_info = (struct print_info *)user;
1167
1168         /*
1169          * Some printers want to check that they're not walking off the
1170          * end of the packet.
1171          * Rather than pass it all the way down, we set this global.
1172          */
1173         snapend = sp + h->caplen;
1174
1175         hdrlen = (*print_info->printer)(h, sp);
1176         if (xflag) {
1177                 /*
1178                  * Print the raw packet data.
1179                  */
1180                 if (xflag > 1) {
1181                         /*
1182                          * Include the link-layer header.
1183                          */
1184                         default_print(sp, h->caplen);
1185                 } else {
1186                         /*
1187                          * Don't include the link-layer header - and if
1188                          * we have nothing past the link-layer header,
1189                          * print nothing.
1190                          */
1191                         if (h->caplen > hdrlen)
1192                                 default_print(sp + hdrlen,
1193                                     h->caplen - hdrlen);
1194                 }
1195         }
1196
1197         putchar('\n');
1198
1199         --infodelay;
1200         if (infoprint)
1201                 info(0);
1202 }
1203
1204 #ifdef WIN32
1205         /*
1206          * XXX - there should really be libpcap calls to get the version
1207          * number as a string (the string would be generated from #defines
1208          * at run time, so that it's not generated from string constants
1209          * in the library, as, on many UNIX systems, those constants would
1210          * be statically linked into the application executable image, and
1211          * would thus reflect the version of libpcap on the system on
1212          * which the application was *linked*, not the system on which it's
1213          * *running*.
1214          *
1215          * That routine should be documented, unlike the "version[]"
1216          * string, so that UNIX vendors providing their own libpcaps
1217          * don't omit it (as a couple of vendors have...).
1218          *
1219          * Packet.dll should perhaps also export a routine to return the
1220          * version number of the Packet.dll code, to supply the
1221          * "Wpcap_version" information on Windows.
1222          */
1223         char WDversion[]="current-cvs.tcpdump.org";
1224 #if !defined(HAVE_GENERATED_VERSION)
1225         char version[]="current-cvs.tcpdump.org";
1226 #endif
1227         char pcap_version[]="current-cvs.tcpdump.org";
1228         char Wpcap_version[]="3.1";
1229 #endif
1230
1231 /*
1232  * By default, print the specified data out in hex.
1233  */
1234 void
1235 default_print(register const u_char *bp, register u_int length)
1236 {
1237     ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1238 }
1239
1240 #ifdef SIGINFO
1241 RETSIGTYPE requestinfo(int signo _U_)
1242 {
1243         if (infodelay)
1244                 ++infoprint;
1245         else
1246                 info(0);
1247 }
1248 #endif
1249
1250 /*
1251  * Called once each second in verbose mode while dumping to file
1252  */
1253 #ifdef USE_WIN32_MM_TIMER
1254 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
1255                                   DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
1256 {
1257         struct pcap_stat stat;
1258
1259         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1260                 fprintf(stderr, "Got %u\r", packets_captured);
1261 }
1262 #elif defined(HAVE_ALARM)
1263 static void verbose_stats_dump(int sig _U_)
1264 {
1265         struct pcap_stat stat;
1266
1267         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1268                 fprintf(stderr, "Got %u\r", packets_captured);
1269         alarm(1);
1270 }
1271 #endif
1272
1273 static void
1274 usage(void)
1275 {
1276         extern char version[];
1277 #ifndef HAVE_PCAP_LIB_VERSION
1278 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1279         extern char pcap_version[];
1280 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1281         static char pcap_version[] = "unknown";
1282 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1283 #endif /* HAVE_PCAP_LIB_VERSION */
1284
1285 #ifdef HAVE_PCAP_LIB_VERSION
1286 #ifdef WIN32
1287         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1288 #else /* WIN32 */
1289         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1290 #endif /* WIN32 */
1291         (void)fprintf(stderr, "%s\n",pcap_lib_version());
1292 #else /* HAVE_PCAP_LIB_VERSION */
1293 #ifdef WIN32
1294         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1295         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1296 #else /* WIN32 */
1297         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1298         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1299 #endif /* WIN32 */
1300 #endif /* HAVE_PCAP_LIB_VERSION */
1301         (void)fprintf(stderr,
1302 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
1303         (void)fprintf(stderr,
1304 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -M secret ]\n");
1305         (void)fprintf(stderr,
1306 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ]\n");
1307         (void)fprintf(stderr,
1308 "\t\t[ -y datalinktype ] [ -Z user ]\n");
1309         (void)fprintf(stderr,
1310 "\t\t[ expression ]\n");
1311         exit(1);
1312 }
1313
1314
1315
1316 /* VARARGS */
1317 void
1318 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
1319 {
1320         va_list ap;
1321
1322         (void)fprintf(stderr, "%s: ", program_name);
1323         va_start(ap, fmt);
1324         (void)vfprintf(stderr, fmt, ap);
1325         va_end(ap);
1326         if (*fmt) {
1327                 fmt += strlen(fmt);
1328                 if (fmt[-1] != '\n')
1329                         (void)fputc('\n', stderr);
1330         }
1331         exit(1);
1332         /* NOTREACHED */
1333 }
1334
1335 /* VARARGS */
1336 void
1337 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
1338 {
1339         va_list ap;
1340
1341         (void)fprintf(stderr, "%s: WARNING: ", program_name);
1342         va_start(ap, fmt);
1343         (void)vfprintf(stderr, fmt, ap);
1344         va_end(ap);
1345         if (*fmt) {
1346                 fmt += strlen(fmt);
1347                 if (fmt[-1] != '\n')
1348                         (void)fputc('\n', stderr);
1349         }
1350 }
1351