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 1.192 2002-12-19 09:27:57 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 int infodelay;
 101 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 dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 113 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 114
 115 #ifdef SIGINFO
 116 RETSIGTYPE requestinfo(int);
 117 #endif
 118
 119 /* Length of saved portion of packet. */
 120 int snaplen = DEFAULT_SNAPLEN;
 121
 122 struct printer {
 123         pcap_handler f;
 124         int type;
 125 };
 126
 127 static struct printer printers[] = {
 128         { arcnet_if_print,      DLT_ARCNET },
 129         { ether_if_print,       DLT_EN10MB },
 130         { token_if_print,       DLT_IEEE802 },
 131 #ifdef DLT_LANE8023
 132         { lane_if_print,        DLT_LANE8023 },
 133 #endif
 134 #ifdef DLT_CIP
 135         { cip_if_print,         DLT_CIP },
 136 #endif
 137 #ifdef DLT_ATM_CLIP
 138         { cip_if_print,         DLT_ATM_CLIP },
 139 #endif
 140         { sl_if_print,          DLT_SLIP },
 141         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 142         { ppp_if_print,         DLT_PPP },
 143         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 144         { fddi_if_print,        DLT_FDDI },
 145         { null_if_print,        DLT_NULL },
 146 #ifdef DLT_LOOP
 147         { null_if_print,        DLT_LOOP },
 148 #endif
 149         { raw_if_print,         DLT_RAW },
 150         { atm_if_print,         DLT_ATM_RFC1483 },
 151 #ifdef DLT_C_HDLC
 152         { chdlc_if_print,       DLT_C_HDLC },
 153 #endif
 154 #ifdef DLT_HDLC
 155         { chdlc_if_print,       DLT_HDLC },
 156 #endif
 157 #ifdef DLT_PPP_SERIAL
 158         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 159 #endif
 160 #ifdef DLT_PPP_ETHER
 161         { pppoe_if_print,       DLT_PPP_ETHER },
 162 #endif
 163 #ifdef DLT_LINUX_SLL
 164         { sll_if_print,         DLT_LINUX_SLL },
 165 #endif
 166 #ifdef DLT_IEEE802_11
 167         { ieee802_11_if_print,  DLT_IEEE802_11},
 168 #endif
 169 #ifdef DLT_LTALK
 170         { ltalk_if_print,       DLT_LTALK },
 171 #endif
 172 #ifdef DLT_PFLOG
 173         { pflog_if_print,       DLT_PFLOG },
 174 #endif
 175 #ifdef DLT_FR
 176         { fr_if_print,          DLT_FR },
 177 #endif
 178 #ifdef DLT_FRELAY
 179         { fr_if_print,          DLT_FRELAY },
 180 #endif
 181 #ifdef DLT_SUNATM
 182         { sunatm_if_print,      DLT_SUNATM },
 183 #endif
 184 #ifdef DLT_IP_OVER_FC
 185         { ipfc_if_print,        DLT_IP_OVER_FC },
 186 #endif
 187 #ifdef DLT_PRISM_HEADER
 188         { prism_if_print,       DLT_PRISM_HEADER },
 189 #endif
 190 #ifdef DLT_IEEE802_11_RADIO
 191         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 192 #endif
 193         { NULL,                 0 },
 194 };
 195
 196 static pcap_handler
 197 lookup_printer(int type)
 198 {
 199         struct printer *p;
 200
 201         for (p = printers; p->f; ++p)
 202                 if (type == p->type)
 203                         return p->f;
 204
 205         return NULL;
 206         /* NOTREACHED */
 207 }
 208
 209 static pcap_t *pd;
 210
 211 extern int optind;
 212 extern int opterr;
 213 extern char *optarg;
 214
 215 struct dump_info {
 216         char    *WFileName;
 217         pcap_t  *pd;
 218         pcap_dumper_t *p;
 219 };
 220
 221 static void
 222 show_dlts_and_exit(pcap_t *pd)
 223 {
 224         int n_dlts;
 225         int *dlts = 0;
 226         const char *dlt_name;
 227
 228         n_dlts = pcap_list_datalinks(pd, &dlts);
 229         if (n_dlts < 0)
 230                 error("%s", pcap_geterr(pd));
 231         else if (n_dlts == 0 || !dlts)
 232                 error("No data link types.");
 233
 234         (void) fprintf(stderr, "Data link types (use option -y to set):\n");
 235
 236         while (--n_dlts >= 0) {
 237                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 238                 if (dlt_name != NULL) {
 239                         (void) fprintf(stderr, "  %s", dlt_name);
 240
 241                         /*
 242                          * OK, does tcpdump handle that type?
 243                          */
 244                         if (lookup_printer(dlts[n_dlts]) == NULL)
 245                                 (void) fprintf(stderr, " (not supported)");
 246                         putchar('\n');
 247                 } else {
 248                         (void) fprintf(stderr, "  DLT %d (not supported)\n",
 249                             dlts[n_dlts]);
 250                 }
 251         }
 252         free(dlts);
 253         exit(0);
 254 }
 255
 256 int
 257 main(int argc, char **argv)
 258 {
 259         register int cnt, op, i;
 260         bpf_u_int32 localnet, netmask;
 261         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 262         int type;
 263         pcap_handler printer;
 264         struct bpf_program fcode;
 265 #ifndef WIN32
 266         RETSIGTYPE (*oldhandler)(int);
 267 #endif
 268         struct dump_info dumpinfo;
 269         u_char *pcap_userdata;
 270         char ebuf[PCAP_ERRBUF_SIZE];
 271 #ifdef HAVE_PCAP_FINDALLDEVS
 272         pcap_if_t *devpointer;
 273         int devnum;
 274 #endif
 275 #ifdef WIN32
 276         DWORD dwVersion;
 277         DWORD dwWindowsMajorVersion;
 278         u_int UserBufferSize=1000000;
 279 #endif
 280
 281 #ifdef WIN32
 282         dwVersion=GetVersion();         /* get the OS version */
 283         dwWindowsMajorVersion =  (DWORD)(LOBYTE(LOWORD(dwVersion)));
 284         if(wsockinit()!=0) return 1;
 285 #endif /* WIN32 */
 286
 287         cnt = -1;
 288         device = NULL;
 289         infile = NULL;
 290         RFileName = NULL;
 291         WFileName = NULL;
 292         if ((cp = strrchr(argv[0], '/')) != NULL)
 293                 program_name = cp + 1;
 294         else
 295                 program_name = argv[0];
 296
 297         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 298                 error("%s", ebuf);
 299
 300 #ifdef LIBSMI
 301         smiInit("tcpdump");
 302 #endif
 303
 304         opterr = 0;
 305         while (
 306 #ifdef WIN32
 307             (op = getopt(argc, argv, "aAB:c:C:dDeE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 308 #else /* WIN32 */
 309 #ifdef HAVE_PCAP_FINDALLDEVS
 310             (op = getopt(argc, argv, "aAc:C:dDeE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 311 #else /* HAVE_PCAP_FINDALLDEVS */
 312             (op = getopt(argc, argv, "aAc:C:deE:fF:i:lLm:nNOpqr:Rs:StT:uvw:xXy:Y")) != -1)
 313 #endif /* HAVE_PCAP_FINDALLDEVS */
 314 #endif /* WIN32 */
 315                 switch (op) {
 316
 317                 case 'a':
 318                         ++aflag;
 319                         break;
 320
 321                 case 'A':
 322                         ++xflag;
 323                         ++Xflag;
 324                         ++Aflag;
 325                         break;
 326
 327 #ifdef WIN32
 328                 case 'B':
 329                         UserBufferSize = atoi(optarg)*1024;
 330                         if (UserBufferSize < 0)
 331                                 error("invalid packet buffer size %s", optarg);
 332                         break;
 333 #endif /* WIN32 */
 334
 335                 case 'c':
 336                         cnt = atoi(optarg);
 337                         if (cnt <= 0)
 338                                 error("invalid packet count %s", optarg);
 339                         break;
 340
 341                 case 'C':
 342                         Cflag = atoi(optarg) * 1000000;
 343                         if (Cflag < 0)
 344                                 error("invalid file size %s", optarg);
 345                         break;
 346
 347                 case 'd':
 348                         ++dflag;
 349                         break;
 350
 351 #ifdef HAVE_PCAP_FINDALLDEVS
 352                 case 'D':
 353                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 354                                 error("%s", ebuf);
 355                         else {
 356                                 for (i = 0; devpointer != 0; i++) {
 357                                         printf("%d.%s", i+1, devpointer->name);
 358                                         if (devpointer->description != NULL)
 359                                                 printf(" (%s)", devpointer->description);
 360                                         printf("\n");
 361                                         devpointer = devpointer->next;
 362                                 }
 363                         }
 364                         return 0;
 365 #endif /* HAVE_PCAP_FINDALLDEVS */
 366
 367                 case 'L':
 368                         Lflag++;
 369                         break;
 370
 371                 case 'e':
 372                         ++eflag;
 373                         break;
 374
 375                 case 'E':
 376 #ifndef HAVE_LIBCRYPTO
 377                         warning("crypto code not compiled in");
 378 #endif
 379                         espsecret = optarg;
 380                         break;
 381
 382                 case 'f':
 383                         ++fflag;
 384                         break;
 385
 386                 case 'F':
 387                         infile = optarg;
 388                         break;
 389
 390                 case 'i':
 391                         if (optarg[0] == '0' && optarg[1] == 0)
 392                                 error("Invalid adapter index");
 393
 394 #ifdef HAVE_PCAP_FINDALLDEVS
 395                         /*
 396                          * If the argument is a number, treat it as
 397                          * an index into the list of adapters, as
 398                          * printed by "tcpdump -D".
 399                          *
 400                          * This should be OK on UNIX systems, as interfaces
 401                          * shouldn't have names that begin with digits.
 402                          * It can be useful on Windows, where more than
 403                          * one interface can have the same name.
 404                          */
 405                         if ((devnum = atoi(optarg)) != 0) {
 406                                 if (devnum < 0)
 407                                         error("Invalid adapter index");
 408
 409                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 410                                         error("%s", ebuf);
 411                                 else {
 412                                         for (i = 0; i < devnum-1; i++){
 413                                                 devpointer = devpointer->next;
 414                                                 if (devpointer == NULL)
 415                                                         error("Invalid adapter index");
 416                                         }
 417                                 }
 418                                 device = devpointer->name;
 419                                 break;
 420                         }
 421 #endif /* HAVE_PCAP_FINDALLDEVS */
 422                         device = optarg;
 423                         break;
 424
 425                 case 'l':
 426 #ifdef HAVE_SETLINEBUF
 427                         setlinebuf(stdout);
 428 #else
 429                         setvbuf(stdout, NULL, _IOLBF, 0);
 430 #endif
 431                         break;
 432
 433                 case 'n':
 434                         ++nflag;
 435                         break;
 436
 437                 case 'N':
 438                         ++Nflag;
 439                         break;
 440
 441                 case 'm':
 442 #ifdef LIBSMI
 443                         if (smiLoadModule(optarg) == 0) {
 444                                 error("could not load MIB module %s", optarg);
 445                         }
 446                         sflag = 1;
 447 #else
 448                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 449                                       program_name, optarg);
 450                         (void)fprintf(stderr, "(no libsmi support)\n");
 451 #endif
 452
 453                 case 'O':
 454                         Oflag = 0;
 455                         break;
 456
 457                 case 'p':
 458                         ++pflag;
 459                         break;
 460
 461                 case 'q':
 462                         ++qflag;
 463                         break;
 464
 465                 case 'r':
 466                         RFileName = optarg;
 467                         break;
 468
 469                 case 'R':
 470                         Rflag = 0;
 471                         break;
 472
 473                 case 's': {
 474                         char *end;
 475
 476                         snaplen = strtol(optarg, &end, 0);
 477                         if (optarg == end || *end != '\0'
 478                             || snaplen < 0 || snaplen > 65535)
 479                                 error("invalid snaplen %s", optarg);
 480                         else if (snaplen == 0)
 481                                 snaplen = 65535;
 482                         break;
 483                 }
 484
 485                 case 'S':
 486                         ++Sflag;
 487                         break;
 488
 489                 case 't':
 490                         --tflag;
 491                         break;
 492
 493                 case 'T':
 494                         if (strcasecmp(optarg, "vat") == 0)
 495                                 packettype = PT_VAT;
 496                         else if (strcasecmp(optarg, "wb") == 0)
 497                                 packettype = PT_WB;
 498                         else if (strcasecmp(optarg, "rpc") == 0)
 499                                 packettype = PT_RPC;
 500                         else if (strcasecmp(optarg, "rtp") == 0)
 501                                 packettype = PT_RTP;
 502                         else if (strcasecmp(optarg, "rtcp") == 0)
 503                                 packettype = PT_RTCP;
 504                         else if (strcasecmp(optarg, "snmp") == 0)
 505                                 packettype = PT_SNMP;
 506                         else if (strcasecmp(optarg, "cnfp") == 0)
 507                                 packettype = PT_CNFP;
 508                         else
 509                                 error("unknown packet type `%s'", optarg);
 510                         break;
 511
 512                 case 'u':
 513                         ++uflag;
 514                         break;
 515
 516                 case 'v':
 517                         ++vflag;
 518                         break;
 519
 520                 case 'w':
 521                         WFileName = optarg;
 522                         break;
 523
 524                 case 'x':
 525                         ++xflag;
 526                         break;
 527
 528                 case 'X':
 529                         ++xflag;
 530                         ++Xflag;
 531                         break;
 532
 533                 case 'y':
 534                         dlt_name = optarg;
 535                         dlt = pcap_datalink_name_to_val(dlt_name);
 536                         if (dlt < 0)
 537                                 error("invalid data link type %s", dlt_name);
 538                         break;
 539
 540 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 541                 case 'Y':
 542                         {
 543                         /* Undocumented flag */
 544 #ifdef HAVE_PCAP_DEBUG
 545                         extern int pcap_debug;
 546                         pcap_debug = 1;
 547 #else
 548                         extern int yydebug;
 549                         yydebug = 1;
 550 #endif
 551                         }
 552                         break;
 553 #endif
 554                 default:
 555                         usage();
 556                         /* NOTREACHED */
 557                 }
 558
 559         if (aflag && nflag)
 560                 error("-a and -n options are incompatible");
 561
 562         if (tflag > 0)
 563                 thiszone = gmt2local(0);
 564
 565         if (RFileName != NULL) {
 566                 /*
 567                  * We don't need network access, so set it back to the user id.
 568                  * Also, this prevents the user from reading anyone's
 569                  * trace file.
 570                  */
 571 #ifndef WIN32
 572                 setuid(getuid());
 573 #endif /* WIN32 */
 574
 575                 pd = pcap_open_offline(RFileName, ebuf);
 576                 if (pd == NULL)
 577                         error("%s", ebuf);
 578                 localnet = 0;
 579                 netmask = 0;
 580                 if (fflag != 0)
 581                         error("-f and -r options are incompatible");
 582         } else {
 583                 if (device == NULL) {
 584                         device = pcap_lookupdev(ebuf);
 585                         if (device == NULL)
 586                                 error("%s", ebuf);
 587                 }
 588 #ifdef WIN32
 589                 PrintCapBegins(program_name,device);
 590 #endif /* WIN32 */
 591                 *ebuf = '\0';
 592                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
 593                 if (pd == NULL)
 594                         error("%s", ebuf);
 595                 else if (*ebuf)
 596                         warning("%s", ebuf);
 597 #ifdef WIN32
 598                 if(UserBufferSize != 1000000)
 599                         if(pcap_setbuff(pd, UserBufferSize)==-1){
 600                                 error("%s", pcap_geterr(pd));
 601                         }
 602 #endif /* WIN32 */
 603                 if (Lflag)
 604                         show_dlts_and_exit(pd);
 605                 if (dlt >= 0) {
 606 #ifdef HAVE_PCAP_SET_DATALINK
 607                         if (pcap_set_datalink(pd, dlt) < 0)
 608                                 error("%s", pcap_geterr(pd));
 609 #else
 610                         /*
 611                          * We don't actually support changing the
 612                          * data link type, so we only let them
 613                          * set it to what it already is.
 614                          */
 615                         if (dlt != pcap_datalink(pd)) {
 616                                 error("%s is not one of the DLTs supported by this device\n",
 617                                     dlt_name);
 618                         }
 619 #endif
 620                         (void)fprintf(stderr, "%s: data link type %s\n",
 621                                       program_name, dlt_name);
 622                         (void)fflush(stderr);
 623                 }
 624                 i = pcap_snapshot(pd);
 625                 if (snaplen < i) {
 626                         warning("snaplen raised from %d to %d", snaplen, i);
 627                         snaplen = i;
 628                 }
 629                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 630                         localnet = 0;
 631                         netmask = 0;
 632                         warning("%s", ebuf);
 633                 }
 634                 /*
 635                  * Let user own process after socket has been opened.
 636                  */
 637 #ifndef WIN32
 638                 setuid(getuid());
 639 #endif /* WIN32 */
 640         }
 641         if (infile)
 642                 cmdbuf = read_infile(infile);
 643         else
 644                 cmdbuf = copy_argv(&argv[optind]);
 645
 646         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 647                 error("%s", pcap_geterr(pd));
 648         if (dflag) {
 649                 bpf_dump(&fcode, dflag);
 650                 pcap_close(pd);
 651                 exit(0);
 652         }
 653         init_addrtoname(localnet, netmask);
 654
 655         (void)setsignal(SIGTERM, cleanup);
 656         (void)setsignal(SIGINT, cleanup);
 657         /* Cooperate with nohup(1) */
 658 #ifndef WIN32
 659         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
 660                 (void)setsignal(SIGHUP, oldhandler);
 661 #endif /* WIN32 */
 662
 663         if (pcap_setfilter(pd, &fcode) < 0)
 664                 error("%s", pcap_geterr(pd));
 665         if (WFileName) {
 666                 pcap_dumper_t *p = pcap_dump_open(pd, WFileName);
 667                 if (p == NULL)
 668                         error("%s", pcap_geterr(pd));
 669                 if (Cflag != 0) {
 670                         printer = dump_packet_and_trunc;
 671                         dumpinfo.WFileName = WFileName;
 672                         dumpinfo.pd = pd;
 673                         dumpinfo.p = p;
 674                         pcap_userdata = (u_char *)&dumpinfo;
 675                 } else {
 676                         printer = dump_packet;
 677                         pcap_userdata = (u_char *)p;
 678                 }
 679         } else {
 680                 type = pcap_datalink(pd);
 681                 printer = lookup_printer(type);
 682                 if (printer == NULL) {
 683                         dlt_name = pcap_datalink_val_to_name(type);
 684                         if (dlt_name != NULL)
 685                                 error("unsupported data link type %s", dlt_name);
 686                         else
 687                                 error("unsupported data link type %d", type);
 688                 }
 689                 pcap_userdata = 0;
 690         }
 691 #ifdef SIGINFO
 692         (void)setsignal(SIGINFO, requestinfo);
 693 #endif
 694 #ifndef WIN32
 695         if (RFileName == NULL) {
 696                 (void)fprintf(stderr, "%s: listening on %s\n",
 697                     program_name, device);
 698                 (void)fflush(stderr);
 699         }
 700 #endif /* WIN32 */
 701         if (pcap_loop(pd, cnt, printer, pcap_userdata) < 0) {
 702                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
 703                     program_name, pcap_geterr(pd));
 704                 cleanup(0);
 705                 pcap_close(pd);
 706                 exit(1);
 707         }
 708         if (RFileName == NULL)
 709                 info(1);
 710         pcap_close(pd);
 711         exit(0);
 712 }
 713
 714 /* make a clean exit on interrupts */
 715 static RETSIGTYPE
 716 cleanup(int signo)
 717 {
 718
 719         /* Can't print the summary if reading from a savefile */
 720         if (pd != NULL && pcap_file(pd) == NULL) {
 721                 (void)fflush(stdout);
 722                 putc('\n', stderr);
 723                 info(1);
 724         }
 725         if (signo)
 726                 exit(0);
 727 }
 728
 729 void
 730 info(register int verbose)
 731 {
 732         struct pcap_stat stat;
 733
 734         if (pcap_stats(pd, &stat) < 0) {
 735                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
 736                 return;
 737         }
 738
 739         if (!verbose)
 740                 fprintf(stderr, "%s: ", program_name);
 741
 742         (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
 743         if (!verbose)
 744                 fputs(", ", stderr);
 745         else
 746                 putc('\n', stderr);
 747         (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
 748         infoprint = 0;
 749 }
 750
 751 static void
 752 reverse(char *s)
 753 {
 754         int i, j, c;
 755
 756         for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
 757                 c = s[i];
 758                 s[i] = s[j];
 759                 s[j] = c;
 760         }
 761 }
 762
 763
 764 static void
 765 swebitoa(unsigned int n, char *s)
 766 {
 767         unsigned int i;
 768
 769         i = 0;
 770         do {
 771                 s[i++] = n % 10 + '0';
 772         } while ((n /= 10) > 0);
 773
 774         s[i] = '\0';
 775         reverse(s);
 776 }
 777
 778 static void
 779 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 780 {
 781         struct dump_info *dump_info;
 782         static uint cnt = 2;
 783         char *name;
 784
 785         ++infodelay;
 786
 787         dump_info = (struct dump_info *)user;
 788
 789         /*
 790          * XXX - this won't prevent capture files from getting
 791          * larger than Cflag - the last packet written to the
 792          * file could put it over Cflag.
 793          */
 794         if (ftell((FILE *)dump_info->p) > Cflag) {
 795                 name = (char *) malloc(strlen(dump_info->WFileName) + 4);
 796                 if (name == NULL)
 797                         error("dump_packet_and_trunc: malloc");
 798                 strcpy(name, dump_info->WFileName);
 799                 swebitoa(cnt, name + strlen(dump_info->WFileName));
 800                 cnt++;
 801                 pcap_dump_close(dump_info->p);
 802                 dump_info->p = pcap_dump_open(dump_info->pd, name);
 803                 free(name);
 804                 if (dump_info->p == NULL)
 805                         error("%s", pcap_geterr(pd));
 806         }
 807
 808         pcap_dump((u_char *)dump_info->p, h, sp);
 809
 810         --infodelay;
 811         if (infoprint)
 812                 info(0);
 813 }
 814
 815 static void
 816 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
 817 {
 818         ++infodelay;
 819
 820         pcap_dump(user, h, sp);
 821
 822         --infodelay;
 823         if (infoprint)
 824                 info(0);
 825 }
 826
 827 /* Like default_print() but data need not be aligned */
 828 void
 829 default_print_unaligned(register const u_char *cp, register u_int length)
 830 {
 831         register u_int i, s;
 832         register int nshorts;
 833
 834         if (Xflag) {
 835                 ascii_print(cp, length);
 836                 return;
 837         }
 838         nshorts = (u_int) length / sizeof(u_short);
 839         i = 0;
 840         while (--nshorts >= 0) {
 841                 if ((i++ % 8) == 0)
 842                         (void)printf("\n\t\t\t");
 843                 s = *cp++;
 844                 (void)printf(" %02x%02x", s, *cp++);
 845         }
 846         if (length & 1) {
 847                 if ((i % 8) == 0)
 848                         (void)printf("\n\t\t\t");
 849                 (void)printf(" %02x", *cp);
 850         }
 851 }
 852
 853 #ifdef WIN32
 854         /*
 855          * XXX - there should really be libpcap calls to get the version
 856          * number as a string (the string would be generated from #defines
 857          * at run time, so that it's not generated from string constants
 858          * in the library, as, on many UNIX systems, those constants would
 859          * be statically linked into the application executable image, and
 860          * would thus reflect the version of libpcap on the system on
 861          * which the application was *linked*, not the system on which it's
 862          * *running*.
 863          *
 864          * That routine should be documented, unlike the "version[]"
 865          * string, so that UNIX vendors providing their own libpcaps
 866          * don't omit it (as a couple of vendors have...).
 867          *
 868          * Packet.dll should perhaps also export a routine to return the
 869          * version number of the Packet.dll code, to supply the
 870          * "Wpcap_version" information on Windows.
 871          */
 872         char WDversion[]="current-cvs.tcpdump.org";
 873         char version[]="current-cvs.tcpdump.org";
 874         char pcap_version[]="current-cvs.tcpdump.org";
 875         char Wpcap_version[]="3.0 alpha";
 876 #endif
 877
 878 /*
 879  * By default, print the specified data out in hex.
 880  */
 881 void
 882 default_print(register const u_char *bp, register u_int length)
 883 {
 884         default_print_unaligned(bp, length);
 885 }
 886
 887 /*
 888  * By default, print the packet out in hex; if eflag is set, print
 889  * everything, otherwise print everything except for the link-layer
 890  * header.
 891  */
 892 void
 893 default_print_packet(register const u_char *bp, register u_int length,
 894     u_int hdr_length)
 895 {
 896         if (xflag > 1) {
 897                 /*
 898                  * Include the link-layer header.
 899                  */
 900                 default_print_unaligned(bp, length);
 901         } else {
 902                 /*
 903                  * Don't include the link-layer header - and if we have
 904                  * nothing past the link-layer header, print nothing.
 905                  */
 906                 if (length > hdr_length)
 907                         default_print_unaligned(bp + hdr_length,
 908                             length - hdr_length);
 909         }
 910 }
 911
 912 #ifdef SIGINFO
 913 RETSIGTYPE requestinfo(int signo _U_)
 914 {
 915         if (infodelay)
 916                 ++infoprint;
 917         else
 918                 info(0);
 919 }
 920 #endif
 921
 922 static void
 923 usage(void)
 924 {
 925         extern char version[];
 926 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
 927         extern char pcap_version[];
 928 #else
 929         static char pcap_version[] = "unknown";
 930 #endif
 931
 932 #ifdef WIN32
 933         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
 934         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
 935 #else
 936         (void)fprintf(stderr, "%s version %s\n", program_name, version);
 937         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
 938 #endif /* WIN32 */
 939         (void)fprintf(stderr,
 940 #ifdef WIN32
 941 "Usage: %s [-aAdDeflLnNOpqRStuvxX] [-B size] [-c count] [ -C file_size ]\n", program_name);
 942 #else /* WIN32 */
 943 #ifdef HAVE_PCAP_FINDALLDEVS
 944 "Usage: %s [-aAdDeflLnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
 945 #else /* HAVE_PCAP_FINDALLDEVS */
 946 "Usage: %s [-aAdeflLnNOpqRStuvxX] [-c count] [ -C file_size ]\n", program_name);
 947 #endif /* HAVE_PCAP_FINDALLDEVS */
 948 #endif /* WIN32 */
 949         (void)fprintf(stderr,
 950 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n");
 951         (void)fprintf(stderr,
 952 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ]\n");
 953         (void)fprintf(stderr,
 954 "\t\t[ expression ]\n");
 955         exit(1);
 956 }