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 1.207 2003-05-22 16:33:07 hannes 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                 /*
 612                  * We don't need network access, so set it back to the user id.
 613                  * Also, this prevents the user from reading anyone's
 614                  * trace file.
 615                  */
 616 #ifndef WIN32
 617                 setuid(getuid());
 618 #endif /* WIN32 */
 619
 620                 pd = pcap_open_offline(RFileName, ebuf);
 621                 printf("reading from file %s, link-type %u\n",
 622                        RFileName,
 623                        pcap_datalink(pd));
 624                 if (pd == NULL)
 625                         error("%s", ebuf);
 626                 localnet = 0;
 627                 netmask = 0;
 628                 if (fflag != 0)
 629                         error("-f and -r options are incompatible");
 630         } else {
 631                 if (device == NULL) {
 632                         device = pcap_lookupdev(ebuf);
 633                         if (device == NULL)
 634                                 error("%s", ebuf);
 635                 }
 636 #ifdef WIN32
 637                 PrintCapBegins(program_name,device);
 638 #endif /* WIN32 */
 639                 *ebuf = '\0';
 640                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
 641                 if (pd == NULL)
 642                         error("%s", ebuf);
 643                 else if (*ebuf)
 644                         warning("%s", ebuf);
 645 #ifdef WIN32
 646                 if(UserBufferSize != 1000000)
 647                         if(pcap_setbuff(pd, UserBufferSize)==-1){
 648                                 error("%s", pcap_geterr(pd));
 649                         }
 650 #endif /* WIN32 */
 651                 if (Lflag)
 652                         show_dlts_and_exit(pd);
 653                 if (dlt >= 0) {
 654 #ifdef HAVE_PCAP_SET_DATALINK
 655                         if (pcap_set_datalink(pd, dlt) < 0)
 656                                 error("%s", pcap_geterr(pd));
 657 #else
 658                         /*
 659                          * We don't actually support changing the
 660                          * data link type, so we only let them
 661                          * set it to what it already is.
 662                          */
 663                         if (dlt != pcap_datalink(pd)) {
 664                                 error("%s is not one of the DLTs supported by this device\n",
 665                                     dlt_name);
 666                         }
 667 #endif
 668                         (void)fprintf(stderr, "%s: data link type %s\n",
 669                                       program_name, dlt_name);
 670                         (void)fflush(stderr);
 671                 }
 672                 i = pcap_snapshot(pd);
 673                 if (snaplen < i) {
 674                         warning("snaplen raised from %d to %d", snaplen, i);
 675                         snaplen = i;
 676                 }
 677                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 678                         localnet = 0;
 679                         netmask = 0;
 680                         warning("%s", ebuf);
 681                 }
 682                 /*
 683                  * Let user own process after socket has been opened.
 684                  */
 685 #ifndef WIN32
 686                 setuid(getuid());
 687 #endif /* WIN32 */
 688         }
 689         if (infile)
 690                 cmdbuf = read_infile(infile);
 691         else
 692                 cmdbuf = copy_argv(&argv[optind]);
 693
 694         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 695                 error("%s", pcap_geterr(pd));
 696         if (dflag) {
 697                 bpf_dump(&fcode, dflag);
 698                 pcap_close(pd);
 699                 exit(0);
 700         }
 701         init_addrtoname(localnet, netmask);
 702
 703         (void)setsignal(SIGTERM, cleanup);
 704         (void)setsignal(SIGINT, cleanup);
 705         /* Cooperate with nohup(1) */
 706 #ifndef WIN32
 707         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
 708                 (void)setsignal(SIGHUP, oldhandler);
 709 #endif /* WIN32 */
 710
 711         if (pcap_setfilter(pd, &fcode) < 0)
 712                 error("%s", pcap_geterr(pd));
 713         if (WFileName) {
 714                 pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
 715                 if (p == NULL)
 716                         error("%s", pcap_geterr(pd));
 717                 if (Cflag != 0) {
 718                         callback = dump_packet_and_trunc;
 719                         dumpinfo.WFileName = WFileName;
 720                         dumpinfo.pd = pd;
 721                         dumpinfo.p = p;
 722                         pcap_userdata = (u_char *)&dumpinfo;
 723                 } else {
 724                         callback = dump_packet;
 725                         pcap_userdata = (u_char *)p;
 726                 }
 727         } else {
 728                 type = pcap_datalink(pd);
 729                 printinfo.printer = lookup_printer(type);
 730                 if (printinfo.printer == NULL) {
 731                         dlt_name = pcap_datalink_val_to_name(type);
 732                         if (dlt_name != NULL)
 733                                 error("unsupported data link type %s", dlt_name);
 734                         else
 735                                 error("unsupported data link type %d", type);
 736                 }
 737                 callback = print_packet;
 738                 pcap_userdata = (u_char *)&printinfo;
 739         }
 740 #ifdef SIGINFO
 741         (void)setsignal(SIGINFO, requestinfo);
 742 #endif
 743 #ifndef WIN32
 744         if (RFileName == NULL) {
 745                 if (!vflag && !WFileName) {
 746                         (void)fprintf(stderr,
 747                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
 748                             program_name);
 749                 } else
 750                         (void)fprintf(stderr, "%s: ", program_name);
 751                 (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
 752                     device, type, snaplen);
 753                 (void)fflush(stderr);
 754         }
 755 #endif /* WIN32 */
 756         if (pcap_loop(pd, cnt, callback, pcap_userdata) < 0) {
 757                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 758                     program_name, pcap_geterr(pd));
 759                 cleanup(0);
 760                 pcap_close(pd);
 761                 exit(1);
 762         }
 763         if (RFileName == NULL)
 764                 info(1);
 765         pcap_close(pd);
 766         exit(0);
 767 }
 768
 769 /* make a clean exit on interrupts */
 770 static RETSIGTYPE
 771 cleanup(int signo)
 772 {
 773
 774         /* Can't print the summary if reading from a savefile */
 775         if (pd != NULL && pcap_file(pd) == NULL) {
 776                 (void)fflush(stdout);
 777                 putc('\n', stderr);
 778                 info(1);
 779         }
 780         if (signo)
 781                 exit(0);
 782 }
 783
 784 static void
 785 info(register int verbose)
 786 {
 787         struct pcap_stat stat;
 788
 789         if (pcap_stats(pd, &stat) < 0) {
 790                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
 791                 return;
 792         }
 793
 794         if (!verbose)
 795                 fprintf(stderr, "%s: ", program_name);
 796
 797         (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
 798         if (!verbose)
 799                 fputs(", ", stderr);
 800         else
 801                 putc('\n', stderr);
 802         (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
 803         infoprint = 0;
 804 }
 805
 806 static void
 807 reverse(char *s)
 808 {
 809         int i, j, c;
 810
 811         for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
 812                 c = s[i];
 813                 s[i] = s[j];
 814                 s[j] = c;
 815         }
 816 }
 817
 818
 819 static void
 820 swebitoa(unsigned int n, char *s)
 821 {
 822         unsigned int i;
 823
 824         i = 0;
 825         do {
 826                 s[i++] = n % 10 + '0';
 827         } while ((n /= 10) > 0);
 828
 829         s[i] = '\0';
 830         reverse(s);
 831 }
 832
 833 static void
 834 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 835 {
 836         struct dump_info *dump_info;
 837         static uint cnt = 2;
 838         char *name;
 839
 840         ++infodelay;
 841
 842         dump_info = (struct dump_info *)user;
 843
 844         /*
 845          * XXX - this won't prevent capture files from getting
 846          * larger than Cflag - the last packet written to the
 847          * file could put it over Cflag.
 848          */
 849         if (ftell((FILE *)dump_info->p) > Cflag) {
 850                 name = (char *) malloc(strlen(dump_info->WFileName) + 4);
 851                 if (name == NULL)
 852                         error("dump_packet_and_trunc: malloc");
 853                 strcpy(name, dump_info->WFileName);
 854                 swebitoa(cnt, name + strlen(dump_info->WFileName));
 855                 cnt++;
 856                 pcap_dump_close(dump_info->p);
 857                 dump_info->p = pcap_dump_open(dump_info->pd, name);
 858                 free(name);
 859                 if (dump_info->p == NULL)
 860                         error("%s", pcap_geterr(pd));
 861         }
 862
 863         pcap_dump((u_char *)dump_info->p, h, sp);
 864 #ifdef HAVE_PCAP_DUMP_FLUSH
 865         if (Uflag)
 866                 pcap_dump_flush(dump_info->p);
 867 #endif
 868
 869         --infodelay;
 870         if (infoprint)
 871                 info(0);
 872 }
 873
 874 static void
 875 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 876 {
 877         ++infodelay;
 878
 879         pcap_dump(user, h, sp);
 880 #ifdef HAVE_PCAP_DUMP_FLUSH
 881         if (Uflag)
 882                 pcap_dump_flush((pcap_dumper_t *)user);
 883 #endif
 884
 885         --infodelay;
 886         if (infoprint)
 887                 info(0);
 888 }
 889
 890 static void
 891 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 892 {
 893         struct print_info *print_info;
 894         u_int hdrlen;
 895
 896         ++infodelay;
 897         ts_print(&h->ts);
 898
 899         print_info = (struct print_info *)user;
 900
 901         /*
 902          * Some printers want to check that they're not walking off the
 903          * end of the packet.
 904          * Rather than pass it all the way down, we set this global.
 905          */
 906         snapend = sp + h->caplen;
 907
 908         hdrlen = (*print_info->printer)(h, sp);
 909         if (xflag) {
 910                 /*
 911                  * Print the raw packet data.
 912                  */
 913                 if (xflag > 1) {
 914                         /*
 915                          * Include the link-layer header.
 916                          */
 917                         default_print_unaligned(sp, h->caplen);
 918                 } else {
 919                         /*
 920                          * Don't include the link-layer header - and if
 921                          * we have nothing past the link-layer header,
 922                          * print nothing.
 923                          */
 924                         if (h->caplen > hdrlen)
 925                                 default_print_unaligned(sp + hdrlen,
 926                                     h->caplen - hdrlen);
 927                 }
 928         }
 929
 930         putchar('\n');
 931
 932         --infodelay;
 933         if (infoprint)
 934                 info(0);
 935 }
 936
 937 /* Like default_print() but data need not be aligned */
 938 void
 939 default_print_unaligned(register const u_char *cp, register u_int length)
 940 {
 941         register u_int i, s;
 942         register int nshorts;
 943
 944         if (Xflag) {
 945                 ascii_print(cp, length);
 946                 return;
 947         }
 948         nshorts = (u_int) length / sizeof(u_short);
 949         i = 0;
 950         while (--nshorts >= 0) {
 951                 if ((i++ % 8) == 0)
 952                         (void)printf("\n\t\t\t");
 953                 s = *cp++;
 954                 (void)printf(" %02x%02x", s, *cp++);
 955         }
 956         if (length & 1) {
 957                 if ((i % 8) == 0)
 958                         (void)printf("\n\t\t\t");
 959                 (void)printf(" %02x", *cp);
 960         }
 961 }
 962
 963 #ifdef WIN32
 964         /*
 965          * XXX - there should really be libpcap calls to get the version
 966          * number as a string (the string would be generated from #defines
 967          * at run time, so that it's not generated from string constants
 968          * in the library, as, on many UNIX systems, those constants would
 969          * be statically linked into the application executable image, and
 970          * would thus reflect the version of libpcap on the system on
 971          * which the application was *linked*, not the system on which it's
 972          * *running*.
 973          *
 974          * That routine should be documented, unlike the "version[]"
 975          * string, so that UNIX vendors providing their own libpcaps
 976          * don't omit it (as a couple of vendors have...).
 977          *
 978          * Packet.dll should perhaps also export a routine to return the
 979          * version number of the Packet.dll code, to supply the
 980          * "Wpcap_version" information on Windows.
 981          */
 982         char WDversion[]="current-cvs.tcpdump.org";
 983         char version[]="current-cvs.tcpdump.org";
 984         char pcap_version[]="current-cvs.tcpdump.org";
 985         char Wpcap_version[]="3.0 alpha";
 986 #endif
 987
 988 /*
 989  * By default, print the specified data out in hex.
 990  */
 991 void
 992 default_print(register const u_char *bp, register u_int length)
 993 {
 994         default_print_unaligned(bp, length);
 995 }
 996
 997 #ifdef SIGINFO
 998 RETSIGTYPE requestinfo(int signo _U_)
 999 {
1000         if (infodelay)
1001                 ++infoprint;
1002         else
1003                 info(0);
1004 }
1005 #endif
1006
1007 static void
1008 usage(void)
1009 {
1010         extern char version[];
1011 #ifndef HAVE_PCAP_LIB_VERSION
1012 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1013         extern char pcap_version[];
1014 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1015         static char pcap_version[] = "unknown";
1016 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1017 #endif /* HAVE_PCAP_LIB_VERSION */
1018
1019 #ifdef HAVE_PCAP_LIB_VERSION
1020         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1021         (void)fprintf(stderr, "%s\n", pcap_lib_version());
1022 #else /* HAVE_PCAP_LIB_VERSION */
1023 #ifdef WIN32
1024         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1025         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1026 #else /* WIN32 */
1027         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1028         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1029 #endif /* WIN32 */
1030 #endif /* HAVE_PCAP_LIB_VERSION */
1031         (void)fprintf(stderr,
1032 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
1033         (void)fprintf(stderr,
1034 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
1035         (void)fprintf(stderr,
1036 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n");
1037         (void)fprintf(stderr,
1038 "\t\t[ expression ]\n");
1039         exit(1);
1040 }