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[] =
  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[] =
  33     "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.210 2003-07-30 05:51:40 guy Exp $ (LBL)";
  34 #endif
  35
  36 /*
  37  * tcpdump - monitor tcp/ip traffic on an ethernet.
  38  *
  39  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
  40  * Mercilessly hacked and occasionally improved since then via the
  41  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
  42  */
  43
  44 #ifdef HAVE_CONFIG_H
  45 #include "config.h"
  46 #endif
  47
  48 #include <tcpdump-stdinc.h>
  49
  50 #ifdef WIN32
  51 #include "getopt.h"
  52 #include "w32_fzs.h"
  53 extern int strcasecmp (const char *__s1, const char *__s2);
  54 extern int SIZE_BUF;
  55 #define off_t long
  56 #define uint UINT
  57 #endif /* WIN32 */
  58
  59 #include <pcap.h>
  60 #include <signal.h>
  61 #include <stdio.h>
  62 #include <stdlib.h>
  63 #include <string.h>
  64
  65 #include "interface.h"
  66 #include "addrtoname.h"
  67 #include "machdep.h"
  68 #include "setsignal.h"
  69 #include "gmt2local.h"
  70 #include "pcap-missing.h"
  71
  72 int aflag;                      /* translate network and broadcast addresses */
  73 int dflag;                      /* print filter code */
  74 int eflag;                      /* print ethernet header */
  75 int fflag;                      /* don't translate "foreign" IP address */
  76 int Lflag;                      /* list available data link types and exit */
  77 int nflag;                      /* leave addresses as numbers */
  78 int Nflag;                      /* remove domains from printed host names */
  79 int Oflag = 1;                  /* run filter code optimizer */
  80 int pflag;                      /* don't go promiscuous */
  81 int qflag;                      /* quick (shorter) output */
  82 int Rflag = 1;                  /* print sequence # field in AH/ESP*/
  83 int sflag = 0;                  /* use the libsmi to translate OIDs */
  84 int Sflag;                      /* print raw TCP sequence numbers */
  85 int tflag = 1;                  /* print packet arrival time */
  86 int Uflag = 0;                  /* "unbuffered" output of dump files */
  87 int uflag = 0;                  /* Print undecoded NFS handles */
  88 int vflag;                      /* verbose */
  89 int xflag;                      /* print packet in hex */
  90 int Xflag;                      /* print packet in ascii as well as hex */
  91 off_t Cflag = 0;                /* rotate dump files after this many bytes */
  92 int Aflag = 0;                  /* print packet only in ascii observing LF, CR, TAB, SPACE */
  93 int dlt = -1;           /* if != -1, ask libpcap for the DLT it names */
  94
  95 const char *dlt_name = NULL;
  96
  97 char *espsecret = NULL;         /* ESP secret key */
  98
  99 int packettype;
 100
 101 static int infodelay;
 102 static int infoprint;
 103
 104 char *program_name;
 105
 106 int32_t thiszone;               /* seconds offset from gmt to local time */
 107
 108 /* Forwards */
 109 static RETSIGTYPE cleanup(int);
 110 static void usage(void) __attribute__((noreturn));
 111 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
 112
 113 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 114 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 115 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 116
 117 #ifdef SIGINFO
 118 RETSIGTYPE requestinfo(int);
 119 #endif
 120
 121 static void info(int);
 122
 123 /* Length of saved portion of packet. */
 124 int snaplen = DEFAULT_SNAPLEN;
 125
 126 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
 127
 128 struct printer {
 129         if_printer f;
 130         int type;
 131 };
 132
 133 static struct printer printers[] = {
 134         { arcnet_if_print,      DLT_ARCNET },
 135 #ifdef DLT_ARCNET_LINUX
 136         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 137 #endif
 138         { ether_if_print,       DLT_EN10MB },
 139         { token_if_print,       DLT_IEEE802 },
 140 #ifdef DLT_LANE8023
 141         { lane_if_print,        DLT_LANE8023 },
 142 #endif
 143 #ifdef DLT_CIP
 144         { cip_if_print,         DLT_CIP },
 145 #endif
 146 #ifdef DLT_ATM_CLIP
 147         { cip_if_print,         DLT_ATM_CLIP },
 148 #endif
 149         { sl_if_print,          DLT_SLIP },
 150 #ifdef DLT_SLIP_BSDOS
 151         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 152 #endif
 153         { ppp_if_print,         DLT_PPP },
 154 #ifdef DLT_PPP_BSDOS
 155         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 156 #endif
 157         { fddi_if_print,        DLT_FDDI },
 158         { null_if_print,        DLT_NULL },
 159 #ifdef DLT_LOOP
 160         { null_if_print,        DLT_LOOP },
 161 #endif
 162         { raw_if_print,         DLT_RAW },
 163         { atm_if_print,         DLT_ATM_RFC1483 },
 164 #ifdef DLT_C_HDLC
 165         { chdlc_if_print,       DLT_C_HDLC },
 166 #endif
 167 #ifdef DLT_HDLC
 168         { chdlc_if_print,       DLT_HDLC },
 169 #endif
 170 #ifdef DLT_PPP_SERIAL
 171         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 172 #endif
 173 #ifdef DLT_PPP_ETHER
 174         { pppoe_if_print,       DLT_PPP_ETHER },
 175 #endif
 176 #ifdef DLT_LINUX_SLL
 177         { sll_if_print,         DLT_LINUX_SLL },
 178 #endif
 179 #ifdef DLT_IEEE802_11
 180         { ieee802_11_if_print,  DLT_IEEE802_11},
 181 #endif
 182 #ifdef DLT_LTALK
 183         { ltalk_if_print,       DLT_LTALK },
 184 #endif
 185 #ifdef DLT_PFLOG
 186         { pflog_if_print,       DLT_PFLOG },
 187 #endif
 188 #ifdef DLT_FR
 189         { fr_if_print,          DLT_FR },
 190 #endif
 191 #ifdef DLT_FRELAY
 192         { fr_if_print,          DLT_FRELAY },
 193 #endif
 194 #ifdef DLT_SUNATM
 195         { sunatm_if_print,      DLT_SUNATM },
 196 #endif
 197 #ifdef DLT_IP_OVER_FC
 198         { ipfc_if_print,        DLT_IP_OVER_FC },
 199 #endif
 200 #ifdef DLT_PRISM_HEADER
 201         { prism_if_print,       DLT_PRISM_HEADER },
 202 #endif
 203 #ifdef DLT_IEEE802_11_RADIO
 204         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 205 #endif
 206 #ifdef DLT_ENC
 207         { enc_if_print,         DLT_ENC },
 208 #endif
 209         { NULL,                 0 },
 210 };
 211
 212 static if_printer
 213 lookup_printer(int type)
 214 {
 215         struct printer *p;
 216
 217         for (p = printers; p->f; ++p)
 218                 if (type == p->type)
 219                         return p->f;
 220
 221         return NULL;
 222         /* NOTREACHED */
 223 }
 224
 225 static pcap_t *pd;
 226
 227 extern int optind;
 228 extern int opterr;
 229 extern char *optarg;
 230
 231 struct print_info {
 232         if_printer printer;
 233 };
 234
 235 struct dump_info {
 236         char    *WFileName;
 237         pcap_t  *pd;
 238         pcap_dumper_t *p;
 239 };
 240
 241 static void
 242 show_dlts_and_exit(pcap_t *pd)
 243 {
 244         int n_dlts;
 245         int *dlts = 0;
 246         const char *dlt_name;
 247
 248         n_dlts = pcap_list_datalinks(pd, &dlts);
 249         if (n_dlts < 0)
 250                 error("%s", pcap_geterr(pd));
 251         else if (n_dlts == 0 || !dlts)
 252                 error("No data link types.");
 253
 254         (void) fprintf(stderr, "Data link types (use option -y to set):\n");
 255
 256         while (--n_dlts >= 0) {
 257                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 258                 if (dlt_name != NULL) {
 259                         (void) fprintf(stderr, "  %s", dlt_name);
 260
 261                         /*
 262                          * OK, does tcpdump handle that type?
 263                          */
 264                         if (lookup_printer(dlts[n_dlts]) == NULL)
 265                                 (void) fprintf(stderr, " (not supported)");
 266                         putchar('\n');
 267                 } else {
 268                         (void) fprintf(stderr, "  DLT %d (not supported)\n",
 269                             dlts[n_dlts]);
 270                 }
 271         }
 272         free(dlts);
 273         exit(0);
 274 }
 275
 276 /*
 277  * Set up flags that might or might not be supported depending on the
 278  * version of libpcap we're using.
 279  */
 280 #ifdef WIN32
 281 #define B_FLAG          "B:"
 282 #define B_FLAG_USAGE    " [ -B size ]"
 283 #else /* WIN32 */
 284 #define B_FLAG
 285 #define B_FLAG_USAGE
 286 #endif /* WIN32 */
 287
 288 #ifdef HAVE_PCAP_FINDALLDEVS
 289 #define D_FLAG  "D"
 290 #else
 291 #define D_FLAG
 292 #endif
 293
 294 #ifdef HAVE_PCAP_DUMP_FLUSH
 295 #define U_FLAG  "U"
 296 #else
 297 #define U_FLAG
 298 #endif
 299
 300 int
 301 main(int argc, char **argv)
 302 {
 303         register int cnt, op, i;
 304         bpf_u_int32 localnet, netmask;
 305         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 306         pcap_handler callback;
 307         int type;
 308         struct bpf_program fcode;
 309 #ifndef WIN32
 310         RETSIGTYPE (*oldhandler)(int);
 311 #endif
 312         struct print_info printinfo;
 313         struct dump_info dumpinfo;
 314         u_char *pcap_userdata;
 315         char ebuf[PCAP_ERRBUF_SIZE];
 316 #ifdef HAVE_PCAP_FINDALLDEVS
 317         pcap_if_t *devpointer;
 318         int devnum;
 319 #endif
 320 #ifdef WIN32
 321         DWORD dwVersion;
 322         DWORD dwWindowsMajorVersion;
 323         u_int UserBufferSize=1000000;
 324 #endif
 325
 326 #ifdef WIN32
 327         dwVersion=GetVersion();         /* get the OS version */
 328         dwWindowsMajorVersion =  (DWORD)(LOBYTE(LOWORD(dwVersion)));
 329         if(wsockinit()!=0) return 1;
 330 #endif /* WIN32 */
 331
 332         cnt = -1;
 333         device = NULL;
 334         infile = NULL;
 335         RFileName = NULL;
 336         WFileName = NULL;
 337         if ((cp = strrchr(argv[0], '/')) != NULL)
 338                 program_name = cp + 1;
 339         else
 340                 program_name = argv[0];
 341
 342         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 343                 error("%s", ebuf);
 344
 345 #ifdef LIBSMI
 346         smiInit("tcpdump");
 347 #endif
 348
 349         opterr = 0;
 350         while (
 351             (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)
 352                 switch (op) {
 353
 354                 case 'a':
 355                         ++aflag;
 356                         break;
 357
 358                 case 'A':
 359                         ++xflag;
 360                         ++Xflag;
 361                         ++Aflag;
 362                         break;
 363
 364 #ifdef WIN32
 365                 case 'B':
 366                         UserBufferSize = atoi(optarg)*1024;
 367                         if (UserBufferSize < 0)
 368                                 error("invalid packet buffer size %s", optarg);
 369                         break;
 370 #endif /* WIN32 */
 371
 372                 case 'c':
 373                         cnt = atoi(optarg);
 374                         if (cnt <= 0)
 375                                 error("invalid packet count %s", optarg);
 376                         break;
 377
 378                 case 'C':
 379                         Cflag = atoi(optarg) * 1000000;
 380                         if (Cflag < 0)
 381                                 error("invalid file size %s", optarg);
 382                         break;
 383
 384                 case 'd':
 385                         ++dflag;
 386                         break;
 387
 388 #ifdef HAVE_PCAP_FINDALLDEVS
 389                 case 'D':
 390                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 391                                 error("%s", ebuf);
 392                         else {
 393                                 for (i = 0; devpointer != 0; i++) {
 394                                         printf("%d.%s", i+1, devpointer->name);
 395                                         if (devpointer->description != NULL)
 396                                                 printf(" (%s)", devpointer->description);
 397                                         printf("\n");
 398                                         devpointer = devpointer->next;
 399                                 }
 400                         }
 401                         return 0;
 402 #endif /* HAVE_PCAP_FINDALLDEVS */
 403
 404                 case 'L':
 405                         Lflag++;
 406                         break;
 407
 408                 case 'e':
 409                         ++eflag;
 410                         break;
 411
 412                 case 'E':
 413 #ifndef HAVE_LIBCRYPTO
 414                         warning("crypto code not compiled in");
 415 #endif
 416                         espsecret = optarg;
 417                         break;
 418
 419                 case 'f':
 420                         ++fflag;
 421                         break;
 422
 423                 case 'F':
 424                         infile = optarg;
 425                         break;
 426
 427                 case 'i':
 428                         if (optarg[0] == '0' && optarg[1] == 0)
 429                                 error("Invalid adapter index");
 430
 431 #ifdef HAVE_PCAP_FINDALLDEVS
 432                         /*
 433                          * If the argument is a number, treat it as
 434                          * an index into the list of adapters, as
 435                          * printed by "tcpdump -D".
 436                          *
 437                          * This should be OK on UNIX systems, as interfaces
 438                          * shouldn't have names that begin with digits.
 439                          * It can be useful on Windows, where more than
 440                          * one interface can have the same name.
 441                          */
 442                         if ((devnum = atoi(optarg)) != 0) {
 443                                 if (devnum < 0)
 444                                         error("Invalid adapter index");
 445
 446                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 447                                         error("%s", ebuf);
 448                                 else {
 449                                         for (i = 0; i < devnum-1; i++){
 450                                                 devpointer = devpointer->next;
 451                                                 if (devpointer == NULL)
 452                                                         error("Invalid adapter index");
 453                                         }
 454                                 }
 455                                 device = devpointer->name;
 456                                 break;
 457                         }
 458 #endif /* HAVE_PCAP_FINDALLDEVS */
 459                         device = optarg;
 460                         break;
 461
 462                 case 'l':
 463 #ifdef HAVE_SETLINEBUF
 464                         setlinebuf(stdout);
 465 #else
 466                         setvbuf(stdout, NULL, _IOLBF, 0);
 467 #endif
 468                         break;
 469
 470                 case 'n':
 471                         ++nflag;
 472                         break;
 473
 474                 case 'N':
 475                         ++Nflag;
 476                         break;
 477
 478                 case 'm':
 479 #ifdef LIBSMI
 480                         if (smiLoadModule(optarg) == 0) {
 481                                 error("could not load MIB module %s", optarg);
 482                         }
 483                         sflag = 1;
 484 #else
 485                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 486                                       program_name, optarg);
 487                         (void)fprintf(stderr, "(no libsmi support)\n");
 488 #endif
 489
 490                 case 'O':
 491                         Oflag = 0;
 492                         break;
 493
 494                 case 'p':
 495                         ++pflag;
 496                         break;
 497
 498                 case 'q':
 499                         ++qflag;
 500                         break;
 501
 502                 case 'r':
 503                         RFileName = optarg;
 504                         break;
 505
 506                 case 'R':
 507                         Rflag = 0;
 508                         break;
 509
 510                 case 's': {
 511                         char *end;
 512
 513                         snaplen = strtol(optarg, &end, 0);
 514                         if (optarg == end || *end != '\0'
 515                             || snaplen < 0 || snaplen > 65535)
 516                                 error("invalid snaplen %s", optarg);
 517                         else if (snaplen == 0)
 518                                 snaplen = 65535;
 519                         break;
 520                 }
 521
 522                 case 'S':
 523                         ++Sflag;
 524                         break;
 525
 526                 case 't':
 527                         --tflag;
 528                         break;
 529
 530                 case 'T':
 531                         if (strcasecmp(optarg, "vat") == 0)
 532                                 packettype = PT_VAT;
 533                         else if (strcasecmp(optarg, "wb") == 0)
 534                                 packettype = PT_WB;
 535                         else if (strcasecmp(optarg, "rpc") == 0)
 536                                 packettype = PT_RPC;
 537                         else if (strcasecmp(optarg, "rtp") == 0)
 538                                 packettype = PT_RTP;
 539                         else if (strcasecmp(optarg, "rtcp") == 0)
 540                                 packettype = PT_RTCP;
 541                         else if (strcasecmp(optarg, "snmp") == 0)
 542                                 packettype = PT_SNMP;
 543                         else if (strcasecmp(optarg, "cnfp") == 0)
 544                                 packettype = PT_CNFP;
 545                         else if (strcasecmp(optarg, "tftp") == 0)
 546                                 packettype = PT_TFTP;
 547                         else
 548                                 error("unknown packet type `%s'", optarg);
 549                         break;
 550
 551                 case 'u':
 552                         ++uflag;
 553                         break;
 554
 555 #ifdef HAVE_PCAP_DUMP_FLUSH
 556                 case 'U':
 557                         ++Uflag;
 558                         break;
 559 #endif
 560
 561                 case 'v':
 562                         ++vflag;
 563                         break;
 564
 565                 case 'w':
 566                         WFileName = optarg;
 567                         break;
 568
 569                 case 'x':
 570                         ++xflag;
 571                         break;
 572
 573                 case 'X':
 574                         ++xflag;
 575                         ++Xflag;
 576                         break;
 577
 578                 case 'y':
 579                         dlt_name = optarg;
 580                         dlt = pcap_datalink_name_to_val(dlt_name);
 581                         if (dlt < 0)
 582                                 error("invalid data link type %s", dlt_name);
 583                         break;
 584
 585 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 586                 case 'Y':
 587                         {
 588                         /* Undocumented flag */
 589 #ifdef HAVE_PCAP_DEBUG
 590                         extern int pcap_debug;
 591                         pcap_debug = 1;
 592 #else
 593                         extern int yydebug;
 594                         yydebug = 1;
 595 #endif
 596                         }
 597                         break;
 598 #endif
 599                 default:
 600                         usage();
 601                         /* NOTREACHED */
 602                 }
 603
 604         if (aflag && nflag)
 605                 error("-a and -n options are incompatible");
 606
 607         if (tflag > 0)
 608                 thiszone = gmt2local(0);
 609
 610         if (RFileName != NULL) {
 611 #ifndef WIN32
 612                 /*
 613                  * We don't need network access, so relinquish any set-UID
 614                  * or set-GID privileges we have (if any).
 615                  *
 616                  * We do *not* want set-UID privileges when opening a
 617                  * trace file, as that might let the user read other
 618                  * people's trace files (especially if we're set-UID
 619                  * root).
 620                  */
 621                 setuid(getuid());
 622 #endif /* WIN32 */
 623                 pd = pcap_open_offline(RFileName, ebuf);
 624                 if (pd == NULL)
 625                         error("%s", ebuf);
 626                 printf("reading from file %s, link-type %u\n",
 627                        RFileName,
 628                        pcap_datalink(pd));
 629                 localnet = 0;
 630                 netmask = 0;
 631                 if (fflag != 0)
 632                         error("-f and -r options are incompatible");
 633         } else {
 634                 if (device == NULL) {
 635                         device = pcap_lookupdev(ebuf);
 636                         if (device == NULL)
 637                                 error("%s", ebuf);
 638                 }
 639 #ifdef WIN32
 640                 PrintCapBegins(program_name,device);
 641 #endif /* WIN32 */
 642                 *ebuf = '\0';
 643                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
 644                 if (pd == NULL)
 645                         error("%s", ebuf);
 646                 else if (*ebuf)
 647                         warning("%s", ebuf);
 648 #ifdef WIN32
 649                 if(UserBufferSize != 1000000)
 650                         if(pcap_setbuff(pd, UserBufferSize)==-1){
 651                                 error("%s", pcap_geterr(pd));
 652                         }
 653 #endif /* WIN32 */
 654                 if (Lflag)
 655                         show_dlts_and_exit(pd);
 656                 if (dlt >= 0) {
 657 #ifdef HAVE_PCAP_SET_DATALINK
 658                         if (pcap_set_datalink(pd, dlt) < 0)
 659                                 error("%s", pcap_geterr(pd));
 660 #else
 661                         /*
 662                          * We don't actually support changing the
 663                          * data link type, so we only let them
 664                          * set it to what it already is.
 665                          */
 666                         if (dlt != pcap_datalink(pd)) {
 667                                 error("%s is not one of the DLTs supported by this device\n",
 668                                     dlt_name);
 669                         }
 670 #endif
 671                         (void)fprintf(stderr, "%s: data link type %s\n",
 672                                       program_name, dlt_name);
 673                         (void)fflush(stderr);
 674                 }
 675                 i = pcap_snapshot(pd);
 676                 if (snaplen < i) {
 677                         warning("snaplen raised from %d to %d", snaplen, i);
 678                         snaplen = i;
 679                 }
 680                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 681                         localnet = 0;
 682                         netmask = 0;
 683                         warning("%s", ebuf);
 684                 }
 685                 /*
 686                  * Let user own process after socket has been opened.
 687                  */
 688 #ifndef WIN32
 689                 setuid(getuid());
 690 #endif /* WIN32 */
 691         }
 692         if (infile)
 693                 cmdbuf = read_infile(infile);
 694         else
 695                 cmdbuf = copy_argv(&argv[optind]);
 696
 697         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 698                 error("%s", pcap_geterr(pd));
 699         if (dflag) {
 700                 bpf_dump(&fcode, dflag);
 701                 pcap_close(pd);
 702                 exit(0);
 703         }
 704         init_addrtoname(localnet, netmask);
 705
 706 #ifndef WIN32
 707         (void)setsignal(SIGPIPE, cleanup);
 708 #endif /* WIN32 */
 709         (void)setsignal(SIGTERM, cleanup);
 710         (void)setsignal(SIGINT, cleanup);
 711         /* Cooperate with nohup(1) */
 712 #ifndef WIN32
 713         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
 714                 (void)setsignal(SIGHUP, oldhandler);
 715 #endif /* WIN32 */
 716
 717         if (pcap_setfilter(pd, &fcode) < 0)
 718                 error("%s", pcap_geterr(pd));
 719         if (WFileName) {
 720                 pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
 721                 if (p == NULL)
 722                         error("%s", pcap_geterr(pd));
 723                 if (Cflag != 0) {
 724                         callback = dump_packet_and_trunc;
 725                         dumpinfo.WFileName = WFileName;
 726                         dumpinfo.pd = pd;
 727                         dumpinfo.p = p;
 728                         pcap_userdata = (u_char *)&dumpinfo;
 729                 } else {
 730                         callback = dump_packet;
 731                         pcap_userdata = (u_char *)p;
 732                 }
 733         } else {
 734                 type = pcap_datalink(pd);
 735                 printinfo.printer = lookup_printer(type);
 736                 if (printinfo.printer == NULL) {
 737                         dlt_name = pcap_datalink_val_to_name(type);
 738                         if (dlt_name != NULL)
 739                                 error("unsupported data link type %s", dlt_name);
 740                         else
 741                                 error("unsupported data link type %d", type);
 742                 }
 743                 callback = print_packet;
 744                 pcap_userdata = (u_char *)&printinfo;
 745         }
 746 #ifdef SIGINFO
 747         (void)setsignal(SIGINFO, requestinfo);
 748 #endif
 749 #ifndef WIN32
 750         if (RFileName == NULL) {
 751                 if (!vflag && !WFileName) {
 752                         (void)fprintf(stderr,
 753                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
 754                             program_name);
 755                 } else
 756                         (void)fprintf(stderr, "%s: ", program_name);
 757                 (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
 758                     device, pcap_datalink(pd), snaplen);
 759                 (void)fflush(stderr);
 760         }
 761 #endif /* WIN32 */
 762         if (pcap_loop(pd, cnt, callback, pcap_userdata) < 0) {
 763                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 764                     program_name, pcap_geterr(pd));
 765                 cleanup(0);
 766                 pcap_close(pd);
 767                 exit(1);
 768         }
 769         if (RFileName == NULL)
 770                 info(1);
 771         pcap_close(pd);
 772         exit(0);
 773 }
 774
 775 /* make a clean exit on interrupts */
 776 static RETSIGTYPE
 777 cleanup(int signo)
 778 {
 779
 780         /* Can't print the summary if reading from a savefile */
 781         if (pd != NULL && pcap_file(pd) == NULL) {
 782                 (void)fflush(stdout);
 783                 putc('\n', stderr);
 784                 info(1);
 785         }
 786         if (signo)
 787                 exit(0);
 788 }
 789
 790 static void
 791 info(register int verbose)
 792 {
 793         struct pcap_stat stat;
 794
 795         if (pcap_stats(pd, &stat) < 0) {
 796                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
 797                 return;
 798         }
 799
 800         if (!verbose)
 801                 fprintf(stderr, "%s: ", program_name);
 802
 803         (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
 804         if (!verbose)
 805                 fputs(", ", stderr);
 806         else
 807                 putc('\n', stderr);
 808         (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
 809         infoprint = 0;
 810 }
 811
 812 static void
 813 reverse(char *s)
 814 {
 815         int i, j, c;
 816
 817         for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
 818                 c = s[i];
 819                 s[i] = s[j];
 820                 s[j] = c;
 821         }
 822 }
 823
 824
 825 static void
 826 swebitoa(unsigned int n, char *s)
 827 {
 828         unsigned int i;
 829
 830         i = 0;
 831         do {
 832                 s[i++] = n % 10 + '0';
 833         } while ((n /= 10) > 0);
 834
 835         s[i] = '\0';
 836         reverse(s);
 837 }
 838
 839 static void
 840 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 841 {
 842         struct dump_info *dump_info;
 843         static uint cnt = 2;
 844         char *name;
 845
 846         ++infodelay;
 847
 848         dump_info = (struct dump_info *)user;
 849
 850         /*
 851          * XXX - this won't prevent capture files from getting
 852          * larger than Cflag - the last packet written to the
 853          * file could put it over Cflag.
 854          */
 855         if (ftell((FILE *)dump_info->p) > Cflag) {
 856                 name = (char *) malloc(strlen(dump_info->WFileName) + 4);
 857                 if (name == NULL)
 858                         error("dump_packet_and_trunc: malloc");
 859                 strcpy(name, dump_info->WFileName);
 860                 swebitoa(cnt, name + strlen(dump_info->WFileName));
 861                 cnt++;
 862                 pcap_dump_close(dump_info->p);
 863                 dump_info->p = pcap_dump_open(dump_info->pd, name);
 864                 free(name);
 865                 if (dump_info->p == NULL)
 866                         error("%s", pcap_geterr(pd));
 867         }
 868
 869         pcap_dump((u_char *)dump_info->p, h, sp);
 870 #ifdef HAVE_PCAP_DUMP_FLUSH
 871         if (Uflag)
 872                 pcap_dump_flush(dump_info->p);
 873 #endif
 874
 875         --infodelay;
 876         if (infoprint)
 877                 info(0);
 878 }
 879
 880 static void
 881 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 882 {
 883         ++infodelay;
 884
 885         pcap_dump(user, h, sp);
 886 #ifdef HAVE_PCAP_DUMP_FLUSH
 887         if (Uflag)
 888                 pcap_dump_flush((pcap_dumper_t *)user);
 889 #endif
 890
 891         --infodelay;
 892         if (infoprint)
 893                 info(0);
 894 }
 895
 896 static void
 897 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 898 {
 899         struct print_info *print_info;
 900         u_int hdrlen;
 901
 902         ++infodelay;
 903         ts_print(&h->ts);
 904
 905         print_info = (struct print_info *)user;
 906
 907         /*
 908          * Some printers want to check that they're not walking off the
 909          * end of the packet.
 910          * Rather than pass it all the way down, we set this global.
 911          */
 912         snapend = sp + h->caplen;
 913
 914         hdrlen = (*print_info->printer)(h, sp);
 915         if (xflag) {
 916                 /*
 917                  * Print the raw packet data.
 918                  */
 919                 if (xflag > 1) {
 920                         /*
 921                          * Include the link-layer header.
 922                          */
 923                         default_print_unaligned(sp, h->caplen);
 924                 } else {
 925                         /*
 926                          * Don't include the link-layer header - and if
 927                          * we have nothing past the link-layer header,
 928                          * print nothing.
 929                          */
 930                         if (h->caplen > hdrlen)
 931                                 default_print_unaligned(sp + hdrlen,
 932                                     h->caplen - hdrlen);
 933                 }
 934         }
 935
 936         putchar('\n');
 937
 938         --infodelay;
 939         if (infoprint)
 940                 info(0);
 941 }
 942
 943 /* Like default_print() but data need not be aligned */
 944 void
 945 default_print_unaligned(register const u_char *cp, register u_int length)
 946 {
 947         register u_int i, s;
 948         register int nshorts;
 949
 950         if (Xflag) {
 951                 ascii_print(cp, length);
 952                 return;
 953         }
 954         nshorts = (u_int) length / sizeof(u_short);
 955         i = 0;
 956         while (--nshorts >= 0) {
 957                 if ((i++ % 8) == 0)
 958                         (void)printf("\n\t\t\t");
 959                 s = *cp++;
 960                 (void)printf(" %02x%02x", s, *cp++);
 961         }
 962         if (length & 1) {
 963                 if ((i % 8) == 0)
 964                         (void)printf("\n\t\t\t");
 965                 (void)printf(" %02x", *cp);
 966         }
 967 }
 968
 969 #ifdef WIN32
 970         /*
 971          * XXX - there should really be libpcap calls to get the version
 972          * number as a string (the string would be generated from #defines
 973          * at run time, so that it's not generated from string constants
 974          * in the library, as, on many UNIX systems, those constants would
 975          * be statically linked into the application executable image, and
 976          * would thus reflect the version of libpcap on the system on
 977          * which the application was *linked*, not the system on which it's
 978          * *running*.
 979          *
 980          * That routine should be documented, unlike the "version[]"
 981          * string, so that UNIX vendors providing their own libpcaps
 982          * don't omit it (as a couple of vendors have...).
 983          *
 984          * Packet.dll should perhaps also export a routine to return the
 985          * version number of the Packet.dll code, to supply the
 986          * "Wpcap_version" information on Windows.
 987          */
 988         char WDversion[]="current-cvs.tcpdump.org";
 989         char version[]="current-cvs.tcpdump.org";
 990         char pcap_version[]="current-cvs.tcpdump.org";
 991         char Wpcap_version[]="3.0 alpha";
 992 #endif
 993
 994 /*
 995  * By default, print the specified data out in hex.
 996  */
 997 void
 998 default_print(register const u_char *bp, register u_int length)
 999 {
1000         default_print_unaligned(bp, length);
1001 }
1002
1003 #ifdef SIGINFO
1004 RETSIGTYPE requestinfo(int signo _U_)
1005 {
1006         if (infodelay)
1007                 ++infoprint;
1008         else
1009                 info(0);
1010 }
1011 #endif
1012
1013 static void
1014 usage(void)
1015 {
1016         extern char version[];
1017 #ifndef HAVE_PCAP_LIB_VERSION
1018 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1019         extern char pcap_version[];
1020 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1021         static char pcap_version[] = "unknown";
1022 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1023 #endif /* HAVE_PCAP_LIB_VERSION */
1024
1025 #ifdef HAVE_PCAP_LIB_VERSION
1026         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1027         (void)fprintf(stderr, "%s\n", pcap_lib_version());
1028 #else /* HAVE_PCAP_LIB_VERSION */
1029 #ifdef WIN32
1030         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1031         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1032 #else /* WIN32 */
1033         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1034         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1035 #endif /* WIN32 */
1036 #endif /* HAVE_PCAP_LIB_VERSION */
1037         (void)fprintf(stderr,
1038 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
1039         (void)fprintf(stderr,
1040 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
1041         (void)fprintf(stderr,
1042 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n");
1043         (void)fprintf(stderr,
1044 "\t\t[ expression ]\n");
1045         exit(1);
1046 }