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

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * Support for splitting captures into multiple files with a maximum
  22  * file size:
  23  *
  24  * Copyright (c) 2001
  25  *      Seth Webster <swebster@sst.ll.mit.edu>
  26  */
  27
  28 #ifndef lint
  29 static const char copyright[] _U_ =
  30     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  31 The Regents of the University of California.  All rights reserved.\n";
  32 static const char rcsid[] _U_ =
  33     "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.249 2004-10-19 15:59:40 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 #ifdef HAVE_SMI_H
  60 #include <smi.h>
  61 #endif
  62
  63 #include <pcap.h>
  64 #include <signal.h>
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #ifndef WIN32
  69 #include <pwd.h>
  70 #include <grp.h>
  71 #include <errno.h>
  72 #endif /* WIN32 */
  73
  74 #include "netdissect.h"
  75 #include "interface.h"
  76 #include "addrtoname.h"
  77 #include "machdep.h"
  78 #include "setsignal.h"
  79 #include "gmt2local.h"
  80 #include "pcap-missing.h"
  81
  82 netdissect_options Gndo;
  83 netdissect_options *gndo = &Gndo;
  84
  85 /*
  86  * Define the maximum number of files for the -C flag, and how many
  87  * characters can be added to a filename for the -C flag (which
  88  * should be enough to handle MAX_CFLAG - 1).
  89  */
  90 #define MAX_CFLAG       1000000
  91 #define MAX_CFLAG_CHARS 6
  92
  93 int Lflag;          /* list available data link types and exit */
  94
  95 static int infodelay;
  96 static int infoprint;
  97
  98 char *program_name;
  99
 100 int32_t thiszone;               /* seconds offset from gmt to local time */
 101
 102 /* Forwards */
 103 static RETSIGTYPE cleanup(int);
 104 static void usage(void) __attribute__((noreturn));
 105 static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn));
 106
 107 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 108 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 109 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 110 static void droproot(const char *, const char *);
 111 static void ndo_error(netdissect_options *ndo, const char *fmt, ...);
 112 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 113
 114 #ifdef SIGINFO
 115 RETSIGTYPE requestinfo(int);
 116 #endif
 117
 118 #if defined(USE_WIN32_MM_TIMER)
 119   #include <MMsystem.h>
 120   static UINT timer_id;
 121   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
 122 #elif defined(HAVE_ALARM)
 123   static void verbose_stats_dump(int sig);
 124 #endif
 125
 126 static void info(int);
 127 static u_int packets_captured;
 128
 129 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
 130
 131 struct printer {
 132         if_printer f;
 133         int type;
 134 };
 135
 136 static struct printer printers[] = {
 137         { arcnet_if_print,      DLT_ARCNET },
 138 #ifdef DLT_ARCNET_LINUX
 139         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 140 #endif
 141         { ether_if_print,       DLT_EN10MB },
 142         { token_if_print,       DLT_IEEE802 },
 143 #ifdef DLT_LANE8023
 144         { lane_if_print,        DLT_LANE8023 },
 145 #endif
 146 #ifdef DLT_CIP
 147         { cip_if_print,         DLT_CIP },
 148 #endif
 149 #ifdef DLT_ATM_CLIP
 150         { cip_if_print,         DLT_ATM_CLIP },
 151 #endif
 152         { sl_if_print,          DLT_SLIP },
 153 #ifdef DLT_SLIP_BSDOS
 154         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 155 #endif
 156         { ppp_if_print,         DLT_PPP },
 157 #ifdef DLT_PPP_WITHDIRECTION
 158         { ppp_if_print,         DLT_PPP_WITHDIRECTION },
 159 #endif
 160 #ifdef DLT_PPP_BSDOS
 161         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 162 #endif
 163         { fddi_if_print,        DLT_FDDI },
 164         { null_if_print,        DLT_NULL },
 165 #ifdef DLT_LOOP
 166         { null_if_print,        DLT_LOOP },
 167 #endif
 168         { raw_if_print,         DLT_RAW },
 169         { atm_if_print,         DLT_ATM_RFC1483 },
 170 #ifdef DLT_C_HDLC
 171         { chdlc_if_print,       DLT_C_HDLC },
 172 #endif
 173 #ifdef DLT_HDLC
 174         { chdlc_if_print,       DLT_HDLC },
 175 #endif
 176 #ifdef DLT_PPP_SERIAL
 177         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 178 #endif
 179 #ifdef DLT_PPP_ETHER
 180         { pppoe_if_print,       DLT_PPP_ETHER },
 181 #endif
 182 #ifdef DLT_LINUX_SLL
 183         { sll_if_print,         DLT_LINUX_SLL },
 184 #endif
 185 #ifdef DLT_IEEE802_11
 186         { ieee802_11_if_print,  DLT_IEEE802_11},
 187 #endif
 188 #ifdef DLT_LTALK
 189         { ltalk_if_print,       DLT_LTALK },
 190 #endif
 191 #ifdef DLT_PFLOG
 192         { pflog_if_print,       DLT_PFLOG },
 193 #endif
 194 #ifdef DLT_FR
 195         { fr_if_print,          DLT_FR },
 196 #endif
 197 #ifdef DLT_FRELAY
 198         { fr_if_print,          DLT_FRELAY },
 199 #endif
 200 #ifdef DLT_SUNATM
 201         { sunatm_if_print,      DLT_SUNATM },
 202 #endif
 203 #ifdef DLT_IP_OVER_FC
 204         { ipfc_if_print,        DLT_IP_OVER_FC },
 205 #endif
 206 #ifdef DLT_PRISM_HEADER
 207         { prism_if_print,       DLT_PRISM_HEADER },
 208 #endif
 209 #ifdef DLT_IEEE802_11_RADIO
 210         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 211 #endif
 212 #ifdef DLT_ENC
 213         { enc_if_print,         DLT_ENC },
 214 #endif
 215 #ifdef DLT_SYMANTEC_FIREWALL
 216         { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
 217 #endif
 218 #ifdef DLT_APPLE_IP_OVER_IEEE1394
 219         { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
 220 #endif
 221 #ifdef DLT_JUNIPER_ATM1
 222         { juniper_atm1_print,   DLT_JUNIPER_ATM1 },
 223 #endif
 224 #ifdef DLT_JUNIPER_ATM2
 225         { juniper_atm2_print,   DLT_JUNIPER_ATM2 },
 226 #endif
 227         { NULL,                 0 },
 228 };
 229
 230 static if_printer
 231 lookup_printer(int type)
 232 {
 233         struct printer *p;
 234
 235         for (p = printers; p->f; ++p)
 236                 if (type == p->type)
 237                         return p->f;
 238
 239         return NULL;
 240         /* NOTREACHED */
 241 }
 242
 243 static pcap_t *pd;
 244
 245 extern int optind;
 246 extern int opterr;
 247 extern char *optarg;
 248
 249 struct print_info {
 250         if_printer printer;
 251 };
 252
 253 struct dump_info {
 254         char    *WFileName;
 255         pcap_t  *pd;
 256         pcap_dumper_t *p;
 257 };
 258
 259 static void
 260 show_dlts_and_exit(pcap_t *pd)
 261 {
 262         int n_dlts;
 263         int *dlts = 0;
 264         const char *dlt_name;
 265
 266         n_dlts = pcap_list_datalinks(pd, &dlts);
 267         if (n_dlts < 0)
 268                 error("%s", pcap_geterr(pd));
 269         else if (n_dlts == 0 || !dlts)
 270                 error("No data link types.");
 271
 272         (void) fprintf(stderr, "Data link types (use option -y to set):\n");
 273
 274         while (--n_dlts >= 0) {
 275                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 276                 if (dlt_name != NULL) {
 277                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 278                             pcap_datalink_val_to_description(dlts[n_dlts]));
 279
 280                         /*
 281                          * OK, does tcpdump handle that type?
 282                          */
 283                         if (lookup_printer(dlts[n_dlts]) == NULL)
 284                                 (void) fprintf(stderr, " (not supported)");
 285                         putchar('\n');
 286                 } else {
 287                         (void) fprintf(stderr, "  DLT %d (not supported)\n",
 288                             dlts[n_dlts]);
 289                 }
 290         }
 291         free(dlts);
 292         exit(0);
 293 }
 294
 295 /*
 296  * Set up flags that might or might not be supported depending on the
 297  * version of libpcap we're using.
 298  */
 299 #ifdef WIN32
 300 #define B_FLAG          "B:"
 301 #define B_FLAG_USAGE    " [ -B size ]"
 302 #else /* WIN32 */
 303 #define B_FLAG
 304 #define B_FLAG_USAGE
 305 #endif /* WIN32 */
 306
 307 #ifdef HAVE_PCAP_FINDALLDEVS
 308 #ifndef HAVE_PCAP_IF_T
 309 #undef HAVE_PCAP_FINDALLDEVS
 310 #endif
 311 #endif
 312
 313 #ifdef HAVE_PCAP_FINDALLDEVS
 314 #define D_FLAG  "D"
 315 #else
 316 #define D_FLAG
 317 #endif
 318
 319 #ifdef HAVE_PCAP_DUMP_FLUSH
 320 #define U_FLAG  "U"
 321 #else
 322 #define U_FLAG
 323 #endif
 324
 325 #ifndef WIN32
 326 /* Drop root privileges and chroot if necessary */
 327 static void
 328 droproot(const char *username, const char *chroot_dir)
 329 {
 330         struct passwd *pw = NULL;
 331
 332         if (chroot_dir && !username) {
 333                 fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
 334                 exit(1);
 335         }
 336
 337         pw = getpwnam(username);
 338         if (pw) {
 339                 if (chroot_dir) {
 340                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
 341                                 fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
 342                                     chroot_dir, pcap_strerror(errno));
 343                                 exit(1);
 344                         }
 345                 }
 346                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 347                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
 348                         fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
 349                             username,
 350                             (unsigned long)pw->pw_uid,
 351                             (unsigned long)pw->pw_gid,
 352                             pcap_strerror(errno));
 353                         exit(1);
 354                 }
 355         }
 356         else {
 357                 fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
 358                     username);
 359                 exit(1);
 360         }
 361 }
 362 #endif /* WIN32 */
 363
 364 static int
 365 getWflagChars(int x)
 366 {
 367         int c = 0;
 368
 369         x -= 1;
 370         while (x > 0) {
 371                 c += 1;
 372                 x /= 10;
 373         }
 374
 375         return c;
 376 }
 377
 378
 379 static void
 380 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 381 {
 382         if (cnt == 0 && max_chars == 0)
 383                 strcpy(buffer, orig_name);
 384         else
 385                 sprintf(buffer, "%s%0*d", orig_name, max_chars, cnt);
 386 }
 387
 388 static int tcpdump_printf(netdissect_options *ndo _U_,
 389                           const char *fmt, ...)
 390 {
 391
 392   va_list args;
 393   int ret;
 394
 395   va_start(args, fmt);
 396   ret=vfprintf(stdout, fmt, args);
 397   va_end(args);
 398
 399   return ret;
 400 }
 401
 402 int
 403 main(int argc, char **argv)
 404 {
 405         register int cnt, op, i;
 406         bpf_u_int32 localnet, netmask;
 407         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName, *WFileNameAlt;
 408         pcap_handler callback;
 409         int type;
 410         struct bpf_program fcode;
 411 #ifndef WIN32
 412         RETSIGTYPE (*oldhandler)(int);
 413 #endif
 414         struct print_info printinfo;
 415         struct dump_info dumpinfo;
 416         u_char *pcap_userdata;
 417         char ebuf[PCAP_ERRBUF_SIZE];
 418         char *username = NULL;
 419         char *chroot_dir = NULL;
 420 #ifdef HAVE_PCAP_FINDALLDEVS
 421         pcap_if_t *devpointer;
 422         int devnum;
 423 #endif
 424         int status;
 425 #ifdef WIN32
 426         u_int UserBufferSize = 1000000;
 427         if(wsockinit() != 0) return 1;
 428 #endif /* WIN32 */
 429
 430         gndo->ndo_Oflag=1;
 431         gndo->ndo_Rflag=1;
 432         gndo->ndo_dlt=-1;
 433         gndo->ndo_printf=tcpdump_printf;
 434         gndo->ndo_error=ndo_error;
 435         gndo->ndo_warning=ndo_warning;
 436         gndo->ndo_snaplen = DEFAULT_SNAPLEN;
 437
 438         cnt = -1;
 439         device = NULL;
 440         infile = NULL;
 441         RFileName = NULL;
 442         WFileName = NULL;
 443         if ((cp = strrchr(argv[0], '/')) != NULL)
 444                 program_name = cp + 1;
 445         else
 446                 program_name = argv[0];
 447
 448         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 449                 error("%s", ebuf);
 450
 451 #ifdef LIBSMI
 452         smiInit("tcpdump");
 453 #endif
 454
 455         opterr = 0;
 456         while (
 457             (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:YZ:")) != -1)
 458                 switch (op) {
 459
 460                 case 'a':
 461                         /* compatibility for old -a */
 462                         break;
 463
 464                 case 'A':
 465                         ++xflag;
 466                         ++Xflag;
 467                         ++Aflag;
 468                         break;
 469
 470 #ifdef WIN32
 471                 case 'B':
 472                         UserBufferSize = atoi(optarg)*1024;
 473                         if (UserBufferSize < 0)
 474                                 error("invalid packet buffer size %s", optarg);
 475                         break;
 476 #endif /* WIN32 */
 477
 478                 case 'c':
 479                         cnt = atoi(optarg);
 480                         if (cnt <= 0)
 481                                 error("invalid packet count %s", optarg);
 482                         break;
 483
 484                 case 'C':
 485                         Cflag = atoi(optarg) * 1000000;
 486                         if (Cflag < 0)
 487                                 error("invalid file size %s", optarg);
 488                         break;
 489
 490                 case 'd':
 491                         ++dflag;
 492                         break;
 493
 494 #ifdef HAVE_PCAP_FINDALLDEVS
 495                 case 'D':
 496                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 497                                 error("%s", ebuf);
 498                         else {
 499                                 for (i = 0; devpointer != 0; i++) {
 500                                         printf("%d.%s", i+1, devpointer->name);
 501                                         if (devpointer->description != NULL)
 502                                                 printf(" (%s)", devpointer->description);
 503                                         printf("\n");
 504                                         devpointer = devpointer->next;
 505                                 }
 506                         }
 507                         return 0;
 508 #endif /* HAVE_PCAP_FINDALLDEVS */
 509
 510                 case 'L':
 511                         Lflag++;
 512                         break;
 513
 514                 case 'e':
 515                         ++eflag;
 516                         break;
 517
 518                 case 'E':
 519 #ifndef HAVE_LIBCRYPTO
 520                         warning("crypto code not compiled in");
 521 #endif
 522                         gndo->ndo_espsecret = optarg;
 523                         break;
 524
 525                 case 'f':
 526                         ++fflag;
 527                         break;
 528
 529                 case 'F':
 530                         infile = optarg;
 531                         break;
 532
 533                 case 'i':
 534                         if (optarg[0] == '0' && optarg[1] == 0)
 535                                 error("Invalid adapter index");
 536
 537 #ifdef HAVE_PCAP_FINDALLDEVS
 538                         /*
 539                          * If the argument is a number, treat it as
 540                          * an index into the list of adapters, as
 541                          * printed by "tcpdump -D".
 542                          *
 543                          * This should be OK on UNIX systems, as interfaces
 544                          * shouldn't have names that begin with digits.
 545                          * It can be useful on Windows, where more than
 546                          * one interface can have the same name.
 547                          */
 548                         if ((devnum = atoi(optarg)) != 0) {
 549                                 if (devnum < 0)
 550                                         error("Invalid adapter index");
 551
 552                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 553                                         error("%s", ebuf);
 554                                 else {
 555                                         for (i = 0; i < devnum-1; i++){
 556                                                 devpointer = devpointer->next;
 557                                                 if (devpointer == NULL)
 558                                                         error("Invalid adapter index");
 559                                         }
 560                                 }
 561                                 device = devpointer->name;
 562                                 break;
 563                         }
 564 #endif /* HAVE_PCAP_FINDALLDEVS */
 565                         device = optarg;
 566                         break;
 567
 568                 case 'l':
 569 #ifdef WIN32
 570                         /*
 571                          * _IOLBF is the same as _IOFBF in Microsoft's C
 572                          * libraries; the only alternative they offer
 573                          * is _IONBF.
 574                          *
 575                          * XXX - this should really be checking for MSVC++,
 576                          * not WIN32, if, for example, MinGW has its own
 577                          * C library that is more UNIX-compatible.
 578                          */
 579                         setvbuf(stdout, NULL, _IONBF, 0);
 580 #else /* WIN32 */
 581 #ifdef HAVE_SETLINEBUF
 582                         setlinebuf(stdout);
 583 #else
 584                         setvbuf(stdout, NULL, _IOLBF, 0);
 585 #endif
 586 #endif /* WIN32 */
 587                         break;
 588
 589                 case 'n':
 590                         ++nflag;
 591                         break;
 592
 593                 case 'N':
 594                         ++Nflag;
 595                         break;
 596
 597                 case 'm':
 598 #ifdef LIBSMI
 599                         if (smiLoadModule(optarg) == 0) {
 600                                 error("could not load MIB module %s", optarg);
 601                         }
 602                         sflag = 1;
 603 #else
 604                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 605                                       program_name, optarg);
 606                         (void)fprintf(stderr, "(no libsmi support)\n");
 607 #endif
 608                         break;
 609
 610                 case 'M':
 611                         /* TCP-MD5 shared secret */
 612 #ifndef HAVE_LIBCRYPTO
 613                         warning("crypto code not compiled in");
 614 #endif
 615                         tcpmd5secret = optarg;
 616                         break;
 617
 618                 case 'O':
 619                         Oflag = 0;
 620                         break;
 621
 622                 case 'p':
 623                         ++pflag;
 624                         break;
 625
 626                 case 'q':
 627                         ++qflag;
 628                         break;
 629
 630                 case 'r':
 631                         RFileName = optarg;
 632                         break;
 633
 634                 case 'R':
 635                         Rflag = 0;
 636                         break;
 637
 638                 case 's': {
 639                         char *end;
 640
 641                         snaplen = strtol(optarg, &end, 0);
 642                         if (optarg == end || *end != '\0'
 643                             || snaplen < 0 || snaplen > 65535)
 644                                 error("invalid snaplen %s", optarg);
 645                         else if (snaplen == 0)
 646                                 snaplen = 65535;
 647                         break;
 648                 }
 649
 650                 case 'S':
 651                         ++Sflag;
 652                         break;
 653
 654                 case 't':
 655                         ++tflag;
 656                         break;
 657
 658                 case 'T':
 659                         if (strcasecmp(optarg, "vat") == 0)
 660                                 packettype = PT_VAT;
 661                         else if (strcasecmp(optarg, "wb") == 0)
 662                                 packettype = PT_WB;
 663                         else if (strcasecmp(optarg, "rpc") == 0)
 664                                 packettype = PT_RPC;
 665                         else if (strcasecmp(optarg, "rtp") == 0)
 666                                 packettype = PT_RTP;
 667                         else if (strcasecmp(optarg, "rtcp") == 0)
 668                                 packettype = PT_RTCP;
 669                         else if (strcasecmp(optarg, "snmp") == 0)
 670                                 packettype = PT_SNMP;
 671                         else if (strcasecmp(optarg, "cnfp") == 0)
 672                                 packettype = PT_CNFP;
 673                         else if (strcasecmp(optarg, "tftp") == 0)
 674                                 packettype = PT_TFTP;
 675                         else if (strcasecmp(optarg, "aodv") == 0)
 676                                 packettype = PT_AODV;
 677                         else
 678                                 error("unknown packet type `%s'", optarg);
 679                         break;
 680
 681                 case 'u':
 682                         ++uflag;
 683                         break;
 684
 685 #ifdef HAVE_PCAP_DUMP_FLUSH
 686                 case 'U':
 687                         ++Uflag;
 688                         break;
 689 #endif
 690
 691                 case 'v':
 692                         ++vflag;
 693                         break;
 694
 695                 case 'w':
 696                         WFileName = optarg;
 697                         break;
 698
 699                 case 'W':
 700                         Wflag = atoi(optarg);
 701                         if (Wflag < 0)
 702                                 error("invalid number of output files %s", optarg);
 703                         WflagChars = getWflagChars(Wflag);
 704                         break;
 705
 706                 case 'x':
 707                         ++xflag;
 708                         break;
 709
 710                 case 'X':
 711                         ++Xflag;
 712                         break;
 713
 714                 case 'y':
 715                         gndo->ndo_dltname = optarg;
 716                         gndo->ndo_dlt =
 717                           pcap_datalink_name_to_val(gndo->ndo_dltname);
 718                         if (gndo->ndo_dlt < 0)
 719                                 error("invalid data link type %s", gndo->ndo_dltname);
 720                         break;
 721
 722 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 723                 case 'Y':
 724                         {
 725                         /* Undocumented flag */
 726 #ifdef HAVE_PCAP_DEBUG
 727                         extern int pcap_debug;
 728                         pcap_debug = 1;
 729 #else
 730                         extern int yydebug;
 731                         yydebug = 1;
 732 #endif
 733                         }
 734                         break;
 735 #endif
 736                 case 'Z':
 737                         if (optarg) {
 738                                 username = strdup(optarg);
 739                         }
 740                         else {
 741                                 usage();
 742                                 /* NOTREACHED */
 743                         }
 744                         break;
 745
 746                 default:
 747                         usage();
 748                         /* NOTREACHED */
 749                 }
 750
 751         switch (tflag) {
 752
 753         case 0: /* Default */
 754         case 4: /* Default + Date*/
 755                 thiszone = gmt2local(0);
 756                 break;
 757
 758         case 1: /* No time stamp */
 759         case 2: /* Unix timeval style */
 760         case 3: /* Microseconds since previous packet */
 761                 break;
 762
 763         default: /* Not supported */
 764                 error("only -t, -tt, -ttt, and -tttt are supported");
 765                 break;
 766         }
 767
 768 #ifdef WITH_CHROOT
 769         /* if run as root, prepare for chrooting */
 770         if (getuid() == 0 || geteuid() == 0) {
 771                 /* future extensibility for cmd-line arguments */
 772                 if (!chroot_dir)
 773                         chroot_dir = WITH_CHROOT;
 774         }
 775 #endif
 776
 777 #ifdef WITH_USER
 778         /* if run as root, prepare for dropping root privileges */
 779         if (getuid() == 0 || geteuid() == 0) {
 780                 /* Run with '-Z root' to restore old behaviour */
 781                 if (!username)
 782                         username = WITH_USER;
 783         }
 784 #endif
 785
 786         if (RFileName != NULL) {
 787                 int dlt;
 788                 const char *dlt_name;
 789
 790 #ifndef WIN32
 791                 /*
 792                  * We don't need network access, so relinquish any set-UID
 793                  * or set-GID privileges we have (if any).
 794                  *
 795                  * We do *not* want set-UID privileges when opening a
 796                  * trace file, as that might let the user read other
 797                  * people's trace files (especially if we're set-UID
 798                  * root).
 799                  */
 800                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
 801                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
 802 #endif /* WIN32 */
 803                 pd = pcap_open_offline(RFileName, ebuf);
 804                 if (pd == NULL)
 805                         error("%s", ebuf);
 806                 dlt = pcap_datalink(pd);
 807                 dlt_name = pcap_datalink_val_to_name(dlt);
 808                 if (dlt_name == NULL) {
 809                         fprintf(stderr, "reading from file %s, link-type %u\n",
 810                             RFileName, dlt);
 811                 } else {
 812                         fprintf(stderr,
 813                             "reading from file %s, link-type %s (%s)\n",
 814                             RFileName, dlt_name,
 815                             pcap_datalink_val_to_description(dlt));
 816                 }
 817                 localnet = 0;
 818                 netmask = 0;
 819                 if (fflag != 0)
 820                         error("-f and -r options are incompatible");
 821         } else {
 822                 if (device == NULL) {
 823                         device = pcap_lookupdev(ebuf);
 824                         if (device == NULL)
 825                                 error("%s", ebuf);
 826                 }
 827 #ifdef WIN32
 828                 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
 829                 {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
 830                         fprintf(stderr, "%s: listening on %ws\n", program_name, device);
 831                 }
 832                 else
 833                 {
 834                         fprintf(stderr, "%s: listening on %s\n", program_name, device);
 835                 }
 836
 837                 fflush(stderr);
 838 #endif /* WIN32 */
 839                 *ebuf = '\0';
 840                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
 841                 if (pd == NULL)
 842                         error("%s", ebuf);
 843                 else if (*ebuf)
 844                         warning("%s", ebuf);
 845                 /*
 846                  * Let user own process after socket has been opened.
 847                  */
 848 #ifndef WIN32
 849                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
 850                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
 851 #endif /* WIN32 */
 852 #ifdef WIN32
 853                 if(UserBufferSize != 1000000)
 854                         if(pcap_setbuff(pd, UserBufferSize)==-1){
 855                                 error("%s", pcap_geterr(pd));
 856                         }
 857 #endif /* WIN32 */
 858                 if (Lflag)
 859                         show_dlts_and_exit(pd);
 860                 if (gndo->ndo_dlt >= 0) {
 861 #ifdef HAVE_PCAP_SET_DATALINK
 862                         if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
 863                                 error("%s", pcap_geterr(pd));
 864 #else
 865                         /*
 866                          * We don't actually support changing the
 867                          * data link type, so we only let them
 868                          * set it to what it already is.
 869                          */
 870                         if (gndo->ndo_dlt != pcap_datalink(pd)) {
 871                                 error("%s is not one of the DLTs supported by this device\n",
 872                                       gndo->ndo_dltname);
 873                         }
 874 #endif
 875                         (void)fprintf(stderr, "%s: data link type %s\n",
 876                                       program_name, gndo->ndo_dltname);
 877                         (void)fflush(stderr);
 878                 }
 879                 i = pcap_snapshot(pd);
 880                 if (snaplen < i) {
 881                         warning("snaplen raised from %d to %d", snaplen, i);
 882                         snaplen = i;
 883                 }
 884                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
 885                         localnet = 0;
 886                         netmask = 0;
 887                         warning("%s", ebuf);
 888                 }
 889         }
 890         if (infile)
 891                 cmdbuf = read_infile(infile);
 892         else
 893                 cmdbuf = copy_argv(&argv[optind]);
 894
 895         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
 896                 error("%s", pcap_geterr(pd));
 897         if (dflag) {
 898                 bpf_dump(&fcode, dflag);
 899                 pcap_close(pd);
 900                 exit(0);
 901         }
 902         init_addrtoname(localnet, netmask);
 903
 904 #ifndef WIN32
 905         (void)setsignal(SIGPIPE, cleanup);
 906 #endif /* WIN32 */
 907         (void)setsignal(SIGTERM, cleanup);
 908         (void)setsignal(SIGINT, cleanup);
 909         /* Cooperate with nohup(1) */
 910 #ifndef WIN32
 911         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
 912                 (void)setsignal(SIGHUP, oldhandler);
 913 #endif /* WIN32 */
 914
 915         if (pcap_setfilter(pd, &fcode) < 0)
 916                 error("%s", pcap_geterr(pd));
 917         if (WFileName) {
 918                 pcap_dumper_t *p;
 919
 920                 WFileNameAlt = (char *)malloc(strlen(WFileName) + MAX_CFLAG_CHARS + 1);
 921                 if (WFileNameAlt == NULL)
 922                         error("malloc of WFileNameAlt");
 923                 MakeFilename(WFileNameAlt, WFileName, 0, WflagChars);
 924                 p = pcap_dump_open(pd, WFileNameAlt);
 925                 if (p == NULL)
 926                         error("%s", pcap_geterr(pd));
 927                 if (Cflag != 0) {
 928                         callback = dump_packet_and_trunc;
 929                         dumpinfo.WFileName = WFileName;
 930                         dumpinfo.pd = pd;
 931                         dumpinfo.p = p;
 932                         pcap_userdata = (u_char *)&dumpinfo;
 933                 } else {
 934                         callback = dump_packet;
 935                         pcap_userdata = (u_char *)p;
 936                 }
 937         } else {
 938                 type = pcap_datalink(pd);
 939                 printinfo.printer = lookup_printer(type);
 940                 if (printinfo.printer == NULL) {
 941                         gndo->ndo_dltname = pcap_datalink_val_to_name(type);
 942                         if (gndo->ndo_dltname != NULL)
 943                                 error("unsupported data link type %s",
 944                                       gndo->ndo_dltname);
 945                         else
 946                                 error("unsupported data link type %d", type);
 947                 }
 948                 callback = print_packet;
 949                 pcap_userdata = (u_char *)&printinfo;
 950         }
 951 #ifndef WIN32
 952         /*
 953          * We cannot do this earlier, because we want to be able to open
 954          * the file (if done) for writing before giving up permissions.
 955          */
 956         if (getuid() == 0 || geteuid() == 0) {
 957                 if (username || chroot_dir)
 958                         droproot(username, chroot_dir);
 959         }
 960 #endif /* WIN32 */
 961 #ifdef SIGINFO
 962         (void)setsignal(SIGINFO, requestinfo);
 963 #endif
 964
 965         if (vflag > 0 && WFileName) {
 966                 /*
 967                  * When capturing to a file, "-v" means tcpdump should,
 968                  * every 10 secodns, "v"erbosely report the number of
 969                  * packets captured.
 970                  */
 971 #ifdef USE_WIN32_MM_TIMER
 972                 /* call verbose_stats_dump() each 1000 +/-100msec */
 973                 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
 974                 setvbuf(stderr, NULL, _IONBF, 0);
 975 #elif defined(HAVE_ALARM)
 976                 (void)setsignal(SIGALRM, verbose_stats_dump);
 977                 alarm(1);
 978 #endif
 979         }
 980
 981 #ifndef WIN32
 982         if (RFileName == NULL) {
 983                 int dlt;
 984                 const char *dlt_name;
 985
 986                 if (!vflag && !WFileName) {
 987                         (void)fprintf(stderr,
 988                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
 989                             program_name);
 990                 } else
 991                         (void)fprintf(stderr, "%s: ", program_name);
 992                 dlt = pcap_datalink(pd);
 993                 dlt_name = pcap_datalink_val_to_name(dlt);
 994                 if (dlt_name == NULL) {
 995                         (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
 996                             device, dlt, snaplen);
 997                 } else {
 998                         (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
 999                             device, dlt_name,
1000                             pcap_datalink_val_to_description(dlt), snaplen);
1001                 }
1002                 (void)fflush(stderr);
1003         }
1004 #endif /* WIN32 */
1005         status = pcap_loop(pd, cnt, callback, pcap_userdata);
1006         if (WFileName == NULL) {
1007                 /*
1008                  * We're printing packets.  Flush the printed output,
1009                  * so it doesn't get intermingled with error output.
1010                  */
1011                 if (status == -2) {
1012                         /*
1013                          * We got interrupted, so perhaps we didn't
1014                          * manage to finish a line we were printing.
1015                          * Print an extra newline, just in case.
1016                          */
1017                         putchar('\n');
1018                 }
1019                 (void)fflush(stdout);
1020         }
1021         if (status == -1) {
1022                 /*
1023                  * Error.  Report it.
1024                  */
1025                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
1026                     program_name, pcap_geterr(pd));
1027         }
1028         if (RFileName == NULL) {
1029                 /*
1030                  * We're doing a live capture.  Report the capture
1031                  * statistics.
1032                  */
1033                 info(1);
1034         }
1035         pcap_close(pd);
1036         exit(status == -1 ? 1 : 0);
1037 }
1038
1039 /* make a clean exit on interrupts */
1040 static RETSIGTYPE
1041 cleanup(int signo _U_)
1042 {
1043 #ifdef USE_WIN32_MM_TIMER
1044         if (timer_id)
1045                 timeKillEvent(timer_id);
1046         timer_id = 0;
1047 #elif defined(HAVE_ALARM)
1048         alarm(0);
1049 #endif
1050
1051 #ifdef HAVE_PCAP_BREAKLOOP
1052         /*
1053          * We have "pcap_breakloop()"; use it, so that we do as little
1054          * as possible in the signal handler (it's probably not safe
1055          * to do anything with standard I/O streams in a signal handler -
1056          * the ANSI C standard doesn't say it is).
1057          */
1058         pcap_breakloop(pd);
1059 #else
1060         /*
1061          * We don't have "pcap_breakloop()"; this isn't safe, but
1062          * it's the best we can do.  Print the summary if we're
1063          * not reading from a savefile - i.e., if we're doing a
1064          * live capture - and exit.
1065          */
1066         if (pd != NULL && pcap_file(pd) == NULL) {
1067                 /*
1068                  * We got interrupted, so perhaps we didn't
1069                  * manage to finish a line we were printing.
1070                  * Print an extra newline, just in case.
1071                  */
1072                 putchar('\n');
1073                 (void)fflush(stdout);
1074                 info(1);
1075         }
1076         exit(0);
1077 #endif
1078 }
1079
1080 static void
1081 info(register int verbose)
1082 {
1083         struct pcap_stat stat;
1084
1085         if (pcap_stats(pd, &stat) < 0) {
1086                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1087                 return;
1088         }
1089
1090         if (!verbose)
1091                 fprintf(stderr, "%s: ", program_name);
1092
1093         (void)fprintf(stderr, "%u packets captured", packets_captured);
1094         if (!verbose)
1095                 fputs(", ", stderr);
1096         else
1097                 putc('\n', stderr);
1098         (void)fprintf(stderr, "%d packets received by filter", stat.ps_recv);
1099         if (!verbose)
1100                 fputs(", ", stderr);
1101         else
1102                 putc('\n', stderr);
1103         (void)fprintf(stderr, "%d packets dropped by kernel\n", stat.ps_drop);
1104         infoprint = 0;
1105 }
1106
1107 static void
1108 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1109 {
1110         struct dump_info *dump_info;
1111         char *name;
1112
1113         ++packets_captured;
1114
1115         ++infodelay;
1116
1117         dump_info = (struct dump_info *)user;
1118
1119         /*
1120          * XXX - this won't prevent capture files from getting
1121          * larger than Cflag - the last packet written to the
1122          * file could put it over Cflag.
1123          */
1124         if (ftell((FILE *)dump_info->p) > Cflag) {
1125                 /*
1126                  * Close the current file and open a new one.
1127                  */
1128                 pcap_dump_close(dump_info->p);
1129                 Cflag_count++;
1130                 if (Wflag > 0) {
1131                         if (Cflag_count >= Wflag)
1132                                 Cflag_count = 0;
1133                 } else {
1134                         if (Cflag_count >= MAX_CFLAG)
1135                                 error("too many output files");
1136                 }
1137                 name = (char *)malloc(strlen(dump_info->WFileName) + MAX_CFLAG_CHARS + 1);
1138                 if (name == NULL)
1139                         error("dump_packet_and_trunc: malloc");
1140                 MakeFilename(name, dump_info->WFileName, Cflag_count, WflagChars);
1141                 dump_info->p = pcap_dump_open(dump_info->pd, name);
1142                 free(name);
1143                 if (dump_info->p == NULL)
1144                         error("%s", pcap_geterr(pd));
1145         }
1146
1147         pcap_dump((u_char *)dump_info->p, h, sp);
1148 #ifdef HAVE_PCAP_DUMP_FLUSH
1149         if (Uflag)
1150                 pcap_dump_flush(dump_info->p);
1151 #endif
1152
1153         --infodelay;
1154         if (infoprint)
1155                 info(0);
1156 }
1157
1158 static void
1159 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1160 {
1161         ++packets_captured;
1162
1163         ++infodelay;
1164
1165         pcap_dump(user, h, sp);
1166 #ifdef HAVE_PCAP_DUMP_FLUSH
1167         if (Uflag)
1168                 pcap_dump_flush((pcap_dumper_t *)user);
1169 #endif
1170
1171         --infodelay;
1172         if (infoprint)
1173                 info(0);
1174 }
1175
1176 static void
1177 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1178 {
1179         struct print_info *print_info;
1180         u_int hdrlen;
1181
1182         ++packets_captured;
1183
1184         ++infodelay;
1185         ts_print(&h->ts);
1186
1187         print_info = (struct print_info *)user;
1188
1189         /*
1190          * Some printers want to check that they're not walking off the
1191          * end of the packet.
1192          * Rather than pass it all the way down, we set this global.
1193          */
1194         snapend = sp + h->caplen;
1195
1196         hdrlen = (*print_info->printer)(h, sp);
1197         if (xflag) {
1198                 /*
1199                  * Print the raw packet data.
1200                  */
1201                 if (xflag > 1) {
1202                         /*
1203                          * Include the link-layer header.
1204                          */
1205                         hex_print("\n\t", sp, h->caplen);
1206                 } else {
1207                         /*
1208                          * Don't include the link-layer header - and if
1209                          * we have nothing past the link-layer header,
1210                          * print nothing.
1211                          */
1212                         if (h->caplen > hdrlen)
1213                                 hex_print("\n\t", sp + hdrlen,
1214                                     h->caplen - hdrlen);
1215                 }
1216        } else if (Xflag) {
1217                 /*
1218                  * Print the raw packet data.
1219                  */
1220                 if (Xflag > 1) {
1221                         /*
1222                          * Include the link-layer header.
1223                          */
1224                         ascii_print("\n\t", sp, h->caplen);
1225                 } else {
1226                         /*
1227                          * Don't include the link-layer header - and if
1228                          * we have nothing past the link-layer header,
1229                          * print nothing.
1230                          */
1231                         if (h->caplen > hdrlen)
1232                                 ascii_print("\n\t", sp + hdrlen,
1233                                     h->caplen - hdrlen);
1234                 }
1235         }
1236
1237         putchar('\n');
1238
1239         --infodelay;
1240         if (infoprint)
1241                 info(0);
1242 }
1243
1244 #ifdef WIN32
1245         /*
1246          * XXX - there should really be libpcap calls to get the version
1247          * number as a string (the string would be generated from #defines
1248          * at run time, so that it's not generated from string constants
1249          * in the library, as, on many UNIX systems, those constants would
1250          * be statically linked into the application executable image, and
1251          * would thus reflect the version of libpcap on the system on
1252          * which the application was *linked*, not the system on which it's
1253          * *running*.
1254          *
1255          * That routine should be documented, unlike the "version[]"
1256          * string, so that UNIX vendors providing their own libpcaps
1257          * don't omit it (as a couple of vendors have...).
1258          *
1259          * Packet.dll should perhaps also export a routine to return the
1260          * version number of the Packet.dll code, to supply the
1261          * "Wpcap_version" information on Windows.
1262          */
1263         char WDversion[]="current-cvs.tcpdump.org";
1264 #if !defined(HAVE_GENERATED_VERSION)
1265         char version[]="current-cvs.tcpdump.org";
1266 #endif
1267         char pcap_version[]="current-cvs.tcpdump.org";
1268         char Wpcap_version[]="3.1";
1269 #endif
1270
1271 /*
1272  * By default, print the specified data out in hex.
1273  */
1274 void
1275 default_print(register const u_char *bp, register u_int length)
1276 {
1277         ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1278 }
1279
1280 #ifdef SIGINFO
1281 RETSIGTYPE requestinfo(int signo _U_)
1282 {
1283         if (infodelay)
1284                 ++infoprint;
1285         else
1286                 info(0);
1287 }
1288 #endif
1289
1290 /*
1291  * Called once each second in verbose mode while dumping to file
1292  */
1293 #ifdef USE_WIN32_MM_TIMER
1294 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
1295                                   DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
1296 {
1297         struct pcap_stat stat;
1298
1299         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1300                 fprintf(stderr, "Got %u\r", packets_captured);
1301 }
1302 #elif defined(HAVE_ALARM)
1303 static void verbose_stats_dump(int sig _U_)
1304 {
1305         struct pcap_stat stat;
1306
1307         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1308                 fprintf(stderr, "Got %u\r", packets_captured);
1309         alarm(1);
1310 }
1311 #endif
1312
1313 static void
1314 usage(void)
1315 {
1316         extern char version[];
1317 #ifndef HAVE_PCAP_LIB_VERSION
1318 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1319         extern char pcap_version[];
1320 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1321         static char pcap_version[] = "unknown";
1322 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1323 #endif /* HAVE_PCAP_LIB_VERSION */
1324
1325 #ifdef HAVE_PCAP_LIB_VERSION
1326 #ifdef WIN32
1327         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1328 #else /* WIN32 */
1329         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1330 #endif /* WIN32 */
1331         (void)fprintf(stderr, "%s\n",pcap_lib_version());
1332 #else /* HAVE_PCAP_LIB_VERSION */
1333 #ifdef WIN32
1334         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1335         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1336 #else /* WIN32 */
1337         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1338         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1339 #endif /* WIN32 */
1340 #endif /* HAVE_PCAP_LIB_VERSION */
1341         (void)fprintf(stderr,
1342 "Usage: %s [-aAd" D_FLAG "eflLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [-c count] [ -C file_size ]\n", program_name);
1343         (void)fprintf(stderr,
1344 "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -M secret ]\n");
1345         (void)fprintf(stderr,
1346 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ]\n");
1347         (void)fprintf(stderr,
1348 "\t\t[ -W filecount ] [ -y datalinktype ] [ -Z user ]\n");
1349         (void)fprintf(stderr,
1350 "\t\t[ expression ]\n");
1351         exit(1);
1352 }
1353
1354
1355
1356 /* VARARGS */
1357 static void
1358 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
1359 {
1360         va_list ap;
1361
1362         (void)fprintf(stderr, "%s: ", program_name);
1363         va_start(ap, fmt);
1364         (void)vfprintf(stderr, fmt, ap);
1365         va_end(ap);
1366         if (*fmt) {
1367                 fmt += strlen(fmt);
1368                 if (fmt[-1] != '\n')
1369                         (void)fputc('\n', stderr);
1370         }
1371         exit(1);
1372         /* NOTREACHED */
1373 }
1374
1375 /* VARARGS */
1376 static void
1377 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
1378 {
1379         va_list ap;
1380
1381         (void)fprintf(stderr, "%s: WARNING: ", program_name);
1382         va_start(ap, fmt);
1383         (void)vfprintf(stderr, fmt, ap);
1384         va_end(ap);
1385         if (*fmt) {
1386                 fmt += strlen(fmt);
1387                 if (fmt[-1] != '\n')
1388                         (void)fputc('\n', stderr);
1389         }
1390 }
1391