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 1.193 2002-12-19 09:39:17 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;                  /* Print undecoded NFS handles */
  87 int vflag;                      /* verbose */
  88 int xflag;                      /* print packet in hex */
  89 int Xflag;                      /* print packet in ascii as well as hex */
  90 off_t Cflag = 0;                /* rotate dump files after this many bytes */
  91 int Aflag = 0;                  /* print packet only in ascii observing LF, CR, TAB, SPACE */
  92 int dlt = -1;           /* if != -1, ask libpcap for the DLT it names */
  93
  94 const char *dlt_name = NULL;
  95
  96 char *espsecret = NULL;         /* ESP secret key */
  97
  98 int packettype;
  99
 100 static int infodelay;
 101 static int infoprint;
 102
 103 char *program_name;
 104
 105 int32_t thiszone;               /* seconds offset from gmt to local time */
 106
 107 /* Forwards */
 108 static RETSIGTYPE cleanup(int);
 109 static void usage(void) __attribute__((noreturn));
 110 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
 111
 112 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 113 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 114 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 115
 116 #ifdef SIGINFO
 117 RETSIGTYPE requestinfo(int);
 118 #endif
 119
 120 static void info(int);
 121
 122 /* Length of saved portion of packet. */
 123 int snaplen = DEFAULT_SNAPLEN;
 124
 125 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
 126
 127 struct printer {
 128         if_printer f;
 129         int type;
 130 };
 131
 132 static struct printer printers[] = {
 133         { arcnet_if_print,      DLT_ARCNET },
 134         { ether_if_print,       DLT_EN10MB },
 135         { token_if_print,       DLT_IEEE802 },
 136 #ifdef DLT_LANE8023
 137         { lane_if_print,        DLT_LANE8023 },
 138 #endif
 139 #ifdef DLT_CIP
 140         { cip_if_print,         DLT_CIP },
 141 #endif
 142 #ifdef DLT_ATM_CLIP
 143         { cip_if_print,         DLT_ATM_CLIP },
 144 #endif
 145         { sl_if_print,          DLT_SLIP },
 146         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 147         { ppp_if_print,         DLT_PPP },
 148         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 149         { fddi_if_print,        DLT_FDDI },
 150         { null_if_print,        DLT_NULL },
 151 #ifdef DLT_LOOP
 152         { null_if_print,        DLT_LOOP },
 153 #endif
 154         { raw_if_print,         DLT_RAW },
 155         { atm_if_print,         DLT_ATM_RFC1483 },
 156 #ifdef DLT_C_HDLC
 157         { chdlc_if_print,       DLT_C_HDLC },
 158 #endif
 159 #ifdef DLT_HDLC
 160         { chdlc_if_print,       DLT_HDLC },
 161 #endif
 162 #ifdef DLT_PPP_SERIAL
 163         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 164 #endif
 165 #ifdef DLT_PPP_ETHER
 166         { pppoe_if_print,       DLT_PPP_ETHER },
 167 #endif
 168 #ifdef DLT_LINUX_SLL
 169         { sll_if_print,         DLT_LINUX_SLL },
 170 #endif
 171 #ifdef DLT_IEEE802_11
 172         { ieee802_11_if_print,  DLT_IEEE802_11},
 173 #endif
 174 #ifdef DLT_LTALK
 175         { ltalk_if_print,       DLT_LTALK },
 176 #endif
 177 #ifdef DLT_PFLOG
 178         { pflog_if_print,       DLT_PFLOG },
 179 #endif
 180 #ifdef DLT_FR
 181         { fr_if_print,          DLT_FR },
 182 #endif
 183 #ifdef DLT_FRELAY
 184         { fr_if_print,          DLT_FRELAY },
 185 #endif
 186 #ifdef DLT_SUNATM
 187         { sunatm_if_print,      DLT_SUNATM },
 188 #endif
 189 #ifdef DLT_IP_OVER_FC
 190         { ipfc_if_print,        DLT_IP_OVER_FC },
 191 #endif
 192 #ifdef DLT_PRISM_HEADER
 193         { prism_if_print,       DLT_PRISM_HEADER },
 194 #endif
 195 #ifdef DLT_IEEE802_11_RADIO
 196         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 197 #endif
 198         { NULL,                 0 },
 199 };
 200
 201 static if_printer
 202 lookup_printer(int type)
 203 {
 204         struct printer *p;
 205
 206         for (p = printers; p->f; ++p)
 207                 if (type == p->type)
 208                         return p->f;
 209
 210         return NULL;
 211         /* NOTREACHED */
 212 }
 213
 214 static pcap_t *pd;
 215
 216 extern int optind;
 217 extern int opterr;
 218 extern char *optarg;
 219
 220 struct print_info {
 221         if_printer printer;
 222 };
 223
 224 struct dump_info {
 225         char    *WFileName;
 226         pcap_t  *pd;
 227         pcap_dumper_t *p;
 228 };
 229
 230 static void
 231 show_dlts_and_exit(pcap_t *pd)
 232 {
 233         int n_dlts;
 234         int *dlts = 0;
 235         const char *dlt_name;
 236
 237         n_dlts = pcap_list_datalinks(pd, &dlts);
 238         if (n_dlts < 0)
 239                 error("%s", pcap_geterr(pd));
 240         else if (n_dlts == 0 || !dlts)
 241                 error("No data link types.");
 242
 243         (void) fprintf(stderr, "Data link types (use option -y to set):\n");
 244
 245         while (--n_dlts >= 0) {
 246                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 247                 if (dlt_name != NULL) {
 248                         (void) fprintf(stderr, "  %s", dlt_name);
 249
 250                         /*
 251                          * OK, does tcpdump handle that type?
 252                          */
 253                         if (lookup_printer(dlts[n_dlts]) == NULL)
 254                                 (void) fprintf(stderr, " (not supported)");
 255                         putchar('\n');
 256                 } else {
 257                         (void) fprintf(stderr, "  DLT %d (not supported)\n",
 258                             dlts[n_dlts]);
 259                 }
 260         }
 261         free(dlts);
 262         exit(0);
 263 }
 264
 265 int
 266 main(int argc, char **argv)
 267 {
 268         register int cnt, op, i;
 269         bpf_u_int32 localnet, netmask;
 270         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 271         pcap_handler callback;
 272         int type;
 273         struct bpf_program fcode;
 274 #ifndef WIN32
 275         RETSIGTYPE (*oldhandler)(int);
 276 #endif
 277         struct print_info printinfo;
 278         struct dump_info dumpinfo;
 279         u_char *pcap_userdata;
 280         char ebuf[PCAP_ERRBUF_SIZE];
 281 #ifdef HAVE_PCAP_FINDALLDEVS
 282         pcap_if_t *devpointer;
 283         int devnum;
 284 #endif
 285 #ifdef WIN32
 286         DWORD dwVersion;
 287         DWORD dwWindowsMajorVersion;
 288         u_int UserBufferSize=1000000;
 289 #endif
 290
 291 #ifdef WIN32
 292         dwVersion=GetVersion();         /* get the OS version */
 293         dwWindowsMajorVersion =  (DWORD)(LOBYTE(LOWORD(dwVersion)));
 294         if(wsockinit()!=0) return 1;
 295 #endif /* WIN32 */
 296
 297         cnt = -1;
 298         device = NULL;
 299         infile = NULL;
 300         RFileName = NULL;
 301         WFileName = NULL;
 302         if ((cp = strrchr(argv[0], '/')) != NULL)
 303                 program_name = cp + 1;
 304         else
 305                 program_name = argv[0];
 306
 307         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 308                 error("%s", ebuf);
 309
 310 #ifdef LIBSMI
 311         smiInit("tcpdump");
 312 #endif
 313
 314         opterr = 0;
 315         while (
 316 #ifdef WIN32
 317             (op = getopt(argc, argv, "aAB:c:C:dDeE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 318 #else /* WIN32 */
 319 #ifdef HAVE_PCAP_FINDALLDEVS
 320             (op = getopt(argc, argv, "aAc:C:dDeE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 321 #else /* HAVE_PCAP_FINDALLDEVS */
 322             (op = getopt(argc, argv, "aAc:C:deE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 323 #endif /* HAVE_PCAP_FINDALLDEVS */
 324 #endif /* WIN32 */
 325                 switch (op) {
 326
 327                 case 'a':
 328                         ++aflag;
 329                         break;
 330
 331                 case 'A':
 332                         ++xflag;
 333                         ++Xflag;
 334                         ++Aflag;
 335                         break;
 336
 337 #ifdef WIN32
 338                 case 'B':
 339                         UserBufferSize = atoi(optarg)*1024;
 340                         if (UserBufferSize < 0)
 341                                 error("invalid packet buffer size %s", optarg);
 342                         break;
 343 #endif /* WIN32 */
 344
 345                 case 'c':
 346                         cnt = atoi(optarg);
 347                         if (cnt <= 0)
 348                                 error("invalid packet count %s", optarg);
 349                         break;
 350
 351                 case 'C':
 352                         Cflag = atoi(optarg) * 1000000;
 353                         if (Cflag < 0)
 354                                 error("invalid file size %s", optarg);
 355                         break;
 356
 357                 case 'd':
 358                         ++dflag;
 359                         break;
 360
 361 #ifdef HAVE_PCAP_FINDALLDEVS
 362                 case 'D':
 363                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 364                                 error("%s", ebuf);
 365                         else {
 366                                 for (i = 0; devpointer != 0; i++) {
 367                                         printf("%d.%s", i+1, devpointer->name);
 368                                         if (devpointer->description != NULL)
 369                                                 printf(" (%s)", devpointer->description);
 370                                         printf("\n");
 371                                         devpointer = devpointer->next;
 372                                 }
 373                         }
 374                         return 0;
 375 #endif /* HAVE_PCAP_FINDALLDEVS */
 376
 377                 case 'L':
 378                         Lflag++;
 379                         break;
 380
 381                 case 'e':
 382                         ++eflag;
 383                         break;
 384
 385                 case 'E':
 386 #ifndef HAVE_LIBCRYPTO
 387                         warning("crypto code not compiled in");
 388 #endif
 389                         espsecret = optarg;
 390                         break;
 391
 392                 case 'f':
 393                         ++fflag;
 394                         break;
 395
 396                 case 'F':
 397                         infile = optarg;
 398                         break;
 399
 400                 case 'i':
 401                         if (optarg[0] == '0' && optarg[1] == 0)
 402                                 error("Invalid adapter index");
 403
 404 #ifdef HAVE_PCAP_FINDALLDEVS
 405                         /*
 406                          * If the argument is a number, treat it as
 407                          * an index into the list of adapters, as
 408                          * printed by "tcpdump -D".
 409                          *
 410                          * This should be OK on UNIX systems, as interfaces
 411                          * shouldn't have names that begin with digits.
 412                          * It can be useful on Windows, where more than
 413                          * one interface can have the same name.
 414                          */
 415                         if ((devnum = atoi(optarg)) != 0) {
 416                                 if (devnum < 0)
 417                                         error("Invalid adapter index");
 418
 419                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 420                                         error("%s", ebuf);
 421                                 else {
 422                                         for (i = 0; i < devnum-1; i++){
 423                                                 devpointer = devpointer->next;
 424                                                 if (devpointer == NULL)
 425                                                         error("Invalid adapter index");
 426                                         }
 427                                 }
 428                                 device = devpointer->name;
 429                                 break;
 430                         }
 431 #endif /* HAVE_PCAP_FINDALLDEVS */
 432                         device = optarg;
 433                         break;
 434
 435                 case 'l':
 436 #ifdef HAVE_SETLINEBUF
 437                         setlinebuf(stdout);
 438 #else
 439                         setvbuf(stdout, NULL, _IOLBF, 0);
 440 #endif
 441                         break;
 442
 443                 case 'n':
 444                         ++nflag;
 445                         break;
 446
 447                 case 'N':
 448                         ++Nflag;
 449                         break;
 450
 451                 case 'm':
 452 #ifdef LIBSMI
 453                         if (smiLoadModule(optarg) == 0) {
 454                                 error("could not load MIB module %s", optarg);
 455                         }
 456                         sflag = 1;
 457 #else
 458                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 459                                       program_name, optarg);
 460                         (void)fprintf(stderr, "(no libsmi support)\n");
 461 #endif
 462
 463                 case 'O':
 464                         Oflag = 0;
 465                         break;
 466
 467                 case 'p':
 468                         ++pflag;
 469                         break;
 470
 471                 case 'q':
 472                         ++qflag;
 473                         break;
 474
 475                 case 'r':
 476                         RFileName = optarg;
 477                         break;
 478
 479                 case 'R':
 480                         Rflag = 0;
 481                         break;
 482
 483                 case 's': {
 484                         char *end;
 485
 486                         snaplen = strtol(optarg, &end, 0);
 487                         if (optarg == end || *end != '\0'
 488                             || snaplen < 0 || snaplen > 65535)
 489                                 error("invalid snaplen %s", optarg);
 490                         else if (snaplen == 0)
 491                                 snaplen = 65535;
 492                         break;
 493                 }
 494
 495                 case 'S':
 496                         ++Sflag;
 497                         break;
 498
 499                 case 't':
 500                         --tflag;
 501                         break;
 502
 503                 case 'T':
 504                         if (strcasecmp(optarg, "vat") == 0)
 505                                 packettype = PT_VAT;
 506                         else if (strcasecmp(optarg, "wb") == 0)
 507                                 packettype = PT_WB;
 508                         else if (strcasecmp(optarg, "rpc") == 0)
 509                                 packettype = PT_RPC;
 510                         else if (strcasecmp(optarg, "rtp") == 0)
 511                                 packettype = PT_RTP;
 512                         else if (strcasecmp(optarg, "rtcp") == 0)
 513                                 packettype = PT_RTCP;
 514                         else if (strcasecmp(optarg, "snmp") == 0)
 515                                 packettype = PT_SNMP;
 516                         else if (strcasecmp(optarg, "cnfp") == 0)
 517                                 packettype = PT_CNFP;
 518                         else
 519                                 error("unknown packet type `%s'", optarg);
 520                         break;
 521
 522                 case 'u':
 523                         ++uflag;
 524                         break;
 525
 526                 case 'v':
 527                         ++vflag;
 528                         break;
 529
 530                 case 'w':
 531                         WFileName = optarg;
 532                         break;
 533
 534                 case 'x':
 535                         ++xflag;
 536                         break;
 537
 538                 case 'X':
 539                         ++xflag;
 540                         ++Xflag;
 541                         break;
 542
 543                 case 'y':
 544                         dlt_name = optarg;
 545                         dlt = pcap_datalink_name_to_val(dlt_name);
 546                         if (dlt < 0)
 547                                 error("invalid data link type %s", dlt_name);
 548                         break;
 549
 550 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 551                 case 'Y':
 552                         {
 553                         /* Undocumented flag */
 554 #ifdef HAVE_PCAP_DEBUG
 555                         extern int pcap_debug;
 556                         pcap_debug = 1;
 557 #else
 558                         extern int yydebug;
 559                         yydebug = 1;
 560 #endif
 561                         }
 562                         break;
 563 #endif
 564                 default:
 565                         usage();
 566                         /* NOTREACHED */
 567                 }
 568
 569         if (aflag && nflag)
 570                 error("-a and -n options are incompatible");
 571
 572         if (tflag > 0)
 573                 thiszone = gmt2local(0);
 574
 575         if (RFileName != NULL) {
 576                 /*
 577                  * We don't need network access, so set it back to the user id.
 578                  * Also, this prevents the user from reading anyone's
 579                  * trace file.
 580                  */
 581 #ifndef WIN32
 582                 setuid(getuid());
 583 #endif /* WIN32 */
 584
 585                 pd = pcap_open_offline(RFileName, ebuf);
 586                 if (pd == NULL)
 587                         error("%s", ebuf);
 588                 localnet = 0;
 589                 netmask = 0;
 590                 if (fflag != 0)
 591                         error("-f and -r options are incompatible");
 592         } else {
 593                 if (device == NULL) {
 594                         device = pcap_lookupdev(ebuf);
 595                         if (device == NULL)
 596                                 error("%s", ebuf);
 597                 }
 598 #ifdef WIN32
 599                 PrintCapBegins(program_name,device);
 600 #endif /* WIN32 */
 601                 *ebuf = '\0';
 602                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
 603                 if (pd == NULL)
 604                         error("%s", ebuf);
 605                 else if (*ebuf)
 606                         warning("%s", ebuf);
 607 #ifdef WIN32
 608                 if(UserBufferSize != 1000000)
 609                         if(pcap_setbuff(pd, UserBufferSize)==-1){
 610                                 error("%s", pcap_geterr(pd));
 611                         }
 612 #endif /* WIN32 */
 613                 if (Lflag)
 614                         show_dlts_and_exit(pd);
 615                 if (dlt >= 0) {
 616 #ifdef HAVE_PCAP_SET_DATALINK
 617                         if (pcap_set_datalink(pd, dlt) < 0)
 618                                 error("%s", pcap_geterr(pd));
 619 #else
 620                         /*
 621                          * We don't actually support changing the
 622                          * data link type, so we only let them
 623                          * set it to what it already is.
 624                          */
 625                         if (dlt != pcap_datalink(pd)) {
 626                                 error("%s is not one of the DLTs supported by this device\n",
 627                                     dlt_name);
 628                         }
 629 #endif
 630                         (void)fprintf(stderr, "%s: data link type %s\n",
 631                                       program_name, dlt_name);
 632                         (void)fflush(stderr);
 633                 }
 634                 i = pcap_snapshot(pd);
 635                 if (snaplen < i) {
 636                         warning("snaplen raised from %d to %d", snaplen, i);
 637                         snaplen = i;
 638                 }
 639                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 640                         localnet = 0;
 641                         netmask = 0;
 642                         warning("%s", ebuf);
 643                 }
 644                 /*
 645                  * Let user own process after socket has been opened.
 646                  */
 647 #ifndef WIN32
 648                 setuid(getuid());
 649 #endif /* WIN32 */
 650         }
 651         if (infile)
 652                 cmdbuf = read_infile(infile);
 653         else
 654                 cmdbuf = copy_argv(&argv[optind]);
 655
 656         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 657                 error("%s", pcap_geterr(pd));
 658         if (dflag) {
 659                 bpf_dump(&fcode, dflag);
 660                 pcap_close(pd);
 661                 exit(0);
 662         }
 663         init_addrtoname(localnet, netmask);
 664
 665         (void)setsignal(SIGTERM, cleanup);
 666         (void)setsignal(SIGINT, cleanup);
 667         /* Cooperate with nohup(1) */
 668 #ifndef WIN32
 669         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
 670                 (void)setsignal(SIGHUP, oldhandler);
 671 #endif /* WIN32 */
 672
 673         if (pcap_setfilter(pd, &fcode) < 0)
 674                 error("%s", pcap_geterr(pd));
 675         if (WFileName) {
 676                 pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
 677                 if (p == NULL)
 678                         error("%s", pcap_geterr(pd));
 679                 if (Cflag != 0) {
 680                         callback = dump_packet_and_trunc;
 681                         dumpinfo.WFileName = WFileName;
 682                         dumpinfo.pd = pd;
 683                         dumpinfo.p = p;
 684                         pcap_userdata = (u_char *)&dumpinfo;
 685                 } else {
 686                         callback = dump_packet;
 687                         pcap_userdata = (u_char *)p;
 688                 }
 689         } else {
 690                 type = pcap_datalink(pd);
 691                 printinfo.printer = lookup_printer(type);
 692                 if (printinfo.printer == NULL) {
 693                         dlt_name = pcap_datalink_val_to_name(type);
 694                         if (dlt_name != NULL)
 695                                 error("unsupported data link type %s", dlt_name);
 696                         else
 697                                 error("unsupported data link type %d", type);
 698                 }
 699                 callback = print_packet;
 700                 pcap_userdata = (u_char *)&printinfo;
 701         }
 702 #ifdef SIGINFO
 703         (void)setsignal(SIGINFO, requestinfo);
 704 #endif
 705 #ifndef WIN32
 706         if (RFileName == NULL) {
 707                 (void)fprintf(stderr, "%s: listening on %s\n",
 708                     program_name, device);
 709                 (void)fflush(stderr);
 710         }
 711 #endif /* WIN32 */
 712         if (pcap_loop(pd, cnt, callback, pcap_userdata) < 0) {
 713                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 714                     program_name, pcap_geterr(pd));
 715                 cleanup(0);
 716                 pcap_close(pd);
 717                 exit(1);
 718         }
 719         if (RFileName == NULL)
 720                 info(1);
 721         pcap_close(pd);
 722         exit(0);
 723 }
 724
 725 /* make a clean exit on interrupts */
 726 static RETSIGTYPE
 727 cleanup(int signo)
 728 {
 729
 730         /* Can't print the summary if reading from a savefile */
 731         if (pd != NULL && pcap_file(pd) == NULL) {
 732                 (void)fflush(stdout);
 733                 putc('\n', stderr);
 734                 info(1);
 735         }
 736         if (signo)
 737                 exit(0);
 738 }
 739
 740 static void
 741 info(register int verbose)
 742 {
 743         struct pcap_stat stat;
 744
 745         if (pcap_stats(pd, &stat) < 0) {
 746                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
 747                 return;
 748         }
 749
 750         if (!verbose)
 751                 fprintf(stderr, "%s: ", program_name);
 752
 753         (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
 754         if (!verbose)
 755                 fputs(", ", stderr);
 756         else
 757                 putc('\n', stderr);
 758         (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
 759         infoprint = 0;
 760 }
 761
 762 static void
 763 reverse(char *s)
 764 {
 765         int i, j, c;
 766
 767         for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
 768                 c = s[i];
 769                 s[i] = s[j];
 770                 s[j] = c;
 771         }
 772 }
 773
 774
 775 static void
 776 swebitoa(unsigned int n, char *s)
 777 {
 778         unsigned int i;
 779
 780         i = 0;
 781         do {
 782                 s[i++] = n % 10 + '0';
 783         } while ((n /= 10) > 0);
 784
 785         s[i] = '\0';
 786         reverse(s);
 787 }
 788
 789 static void
 790 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 791 {
 792         struct dump_info *dump_info;
 793         static uint cnt = 2;
 794         char *name;
 795
 796         ++infodelay;
 797
 798         dump_info = (struct dump_info *)user;
 799
 800         /*
 801          * XXX - this won't prevent capture files from getting
 802          * larger than Cflag - the last packet written to the
 803          * file could put it over Cflag.
 804          */
 805         if (ftell((FILE *)dump_info->p) > Cflag) {
 806                 name = (char *) malloc(strlen(dump_info->WFileName) + 4);
 807                 if (name == NULL)
 808                         error("dump_packet_and_trunc: malloc");
 809                 strcpy(name, dump_info->WFileName);
 810                 swebitoa(cnt, name + strlen(dump_info->WFileName));
 811                 cnt++;
 812                 pcap_dump_close(dump_info->p);
 813                 dump_info->p = pcap_dump_open(dump_info->pd, name);
 814                 free(name);
 815                 if (dump_info->p == NULL)
 816                         error("%s", pcap_geterr(pd));
 817         }
 818
 819         pcap_dump((u_char *)dump_info->p, h, sp);
 820
 821         --infodelay;
 822         if (infoprint)
 823                 info(0);
 824 }
 825
 826 static void
 827 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 828 {
 829         ++infodelay;
 830
 831         pcap_dump(user, h, sp);
 832
 833         --infodelay;
 834         if (infoprint)
 835                 info(0);
 836 }
 837
 838 static void
 839 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 840 {
 841         struct print_info *print_info;
 842         u_int hdrlen;
 843
 844         ++infodelay;
 845         ts_print(&h->ts);
 846
 847         print_info = (struct print_info *)user;
 848
 849         /*
 850          * Some printers want to check that they're not walking off the
 851          * end of the packet.
 852          * Rather than pass it all the way down, we set this global.
 853          */
 854         snapend = sp + h->caplen;
 855
 856         hdrlen = (*print_info->printer)(h, sp);
 857         if (xflag) {
 858                 /*
 859                  * Print the raw packet data.
 860                  */
 861                 if (xflag > 1) {
 862                         /*
 863                          * Include the link-layer header.
 864                          */
 865                         default_print_unaligned(sp, h->caplen);
 866                 } else {
 867                         /*
 868                          * Don't include the link-layer header - and if
 869                          * we have nothing past the link-layer header,
 870                          * print nothing.
 871                          */
 872                         if (h->caplen > hdrlen)
 873                                 default_print_unaligned(sp + hdrlen,
 874                                     h->caplen - hdrlen);
 875                 }
 876         }
 877
 878         putchar('\n');
 879
 880         --infodelay;
 881         if (infoprint)
 882                 info(0);
 883 }
 884
 885 /* Like default_print() but data need not be aligned */
 886 void
 887 default_print_unaligned(register const u_char *cp, register u_int length)
 888 {
 889         register u_int i, s;
 890         register int nshorts;
 891
 892         if (Xflag) {
 893                 ascii_print(cp, length);
 894                 return;
 895         }
 896         nshorts = (u_int) length / sizeof(u_short);
 897         i = 0;
 898         while (--nshorts >= 0) {
 899                 if ((i++ % 8) == 0)
 900                         (void)printf("\n\t\t\t");
 901                 s = *cp++;
 902                 (void)printf(" %02x%02x", s, *cp++);
 903         }
 904         if (length & 1) {
 905                 if ((i % 8) == 0)
 906                         (void)printf("\n\t\t\t");
 907                 (void)printf(" %02x", *cp);
 908         }
 909 }
 910
 911 #ifdef WIN32
 912         /*
 913          * XXX - there should really be libpcap calls to get the version
 914          * number as a string (the string would be generated from #defines
 915          * at run time, so that it's not generated from string constants
 916          * in the library, as, on many UNIX systems, those constants would
 917          * be statically linked into the application executable image, and
 918          * would thus reflect the version of libpcap on the system on
 919          * which the application was *linked*, not the system on which it's
 920          * *running*.
 921          *
 922          * That routine should be documented, unlike the "version[]"
 923          * string, so that UNIX vendors providing their own libpcaps
 924          * don't omit it (as a couple of vendors have...).
 925          *
 926          * Packet.dll should perhaps also export a routine to return the
 927          * version number of the Packet.dll code, to supply the
 928          * "Wpcap_version" information on Windows.
 929          */
 930         char WDversion[]="current-cvs.tcpdump.org";
 931         char version[]="current-cvs.tcpdump.org";
 932         char pcap_version[]="current-cvs.tcpdump.org";
 933         char Wpcap_version[]="3.0 alpha";
 934 #endif
 935
 936 /*
 937  * By default, print the specified data out in hex.
 938  */
 939 void
 940 default_print(register const u_char *bp, register u_int length)
 941 {
 942         default_print_unaligned(bp, length);
 943 }
 944
 945 #ifdef SIGINFO
 946 RETSIGTYPE requestinfo(int signo _U_)
 947 {
 948         if (infodelay)
 949                 ++infoprint;
 950         else
 951                 info(0);
 952 }
 953 #endif
 954
 955 static void
 956 usage(void)
 957 {
 958         extern char version[];
 959 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
 960         extern char pcap_version[];
 961 #else
 962         static char pcap_version[] = "unknown";
 963 #endif
 964
 965 #ifdef WIN32
 966         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
 967         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
 968 #else
 969         (void)fprintf(stderr, "%s version %s\n", program_name, version);
 970         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
 971 #endif /* WIN32 */
 972         (void)fprintf(stderr,
 973 #ifdef WIN32
 974 "Usage: %s [-aAdDeflLnNOpqRStuvxX] [-B size] [-c count] [ -C file_size ]\n", program_name);
 975 #else /* WIN32 */
 976 #ifdef HAVE_PCAP_FINDALLDEVS
 977 "Usage: %s [-aAdDeflLnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
 978 #else /* HAVE_PCAP_FINDALLDEVS */
 979 "Usage: %s [-aAdeflLnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
 980 #endif /* HAVE_PCAP_FINDALLDEVS */
 981 #endif /* WIN32 */
 982         (void)fprintf(stderr,
 983 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
 984         (void)fprintf(stderr,
 985 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n");
 986         (void)fprintf(stderr,
 987 "\t\t[ expression ]\n");
 988         exit(1);
 989 }