contrib/tcpdump/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 1.283 2008-09-25 21:45:50 guy Exp $ (LBL)";
  34 #endif
  35
  36 /* $FreeBSD$ */
  37
  38 /*
  39  * tcpdump - monitor tcp/ip traffic on an ethernet.
  40  *
  41  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
  42  * Mercilessly hacked and occasionally improved since then via the
  43  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
  44  */
  45
  46 #ifdef HAVE_CONFIG_H
  47 #include "config.h"
  48 #endif
  49
  50 #include <tcpdump-stdinc.h>
  51
  52 #ifdef WIN32
  53 #include "getopt.h"
  54 #include "w32_fzs.h"
  55 extern int strcasecmp (const char *__s1, const char *__s2);
  56 extern int SIZE_BUF;
  57 #define off_t long
  58 #define uint UINT
  59 #endif /* WIN32 */
  60
  61 #ifdef HAVE_SMI_H
  62 #include <smi.h>
  63 #endif
  64
  65 #include <pcap.h>
  66 #include <signal.h>
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70 #include <limits.h>
  71 #ifndef WIN32
  72 #include <sys/wait.h>
  73 #include <sys/resource.h>
  74 #include <pwd.h>
  75 #include <grp.h>
  76 #include <errno.h>
  77 #endif /* WIN32 */
  78
  79
  80 #include "netdissect.h"
  81 #include "interface.h"
  82 #include "addrtoname.h"
  83 #include "machdep.h"
  84 #include "setsignal.h"
  85 #include "gmt2local.h"
  86 #include "pcap-missing.h"
  87
  88 #ifndef NAME_MAX
  89 #define NAME_MAX 255
  90 #endif
  91
  92 netdissect_options Gndo;
  93 netdissect_options *gndo = &Gndo;
  94
  95 static int dflag;                       /* print filter code */
  96 static int Lflag;                       /* list available data link types and exit */
  97 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
  98 static int Jflag;                       /* list available time stamp types */
  99 #endif
 100 static char *zflag = NULL;              /* compress each savefile using a specified command (like gzip or bzip2) */
 101
 102 static int infodelay;
 103 static int infoprint;
 104
 105 char *program_name;
 106
 107 int32_t thiszone;               /* seconds offset from gmt to local time */
 108
 109 /* Forwards */
 110 static RETSIGTYPE cleanup(int);
 111 static RETSIGTYPE child_cleanup(int);
 112 static void usage(void) __attribute__((noreturn));
 113 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
 114
 115 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 116 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
 117 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 118 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 119 static void droproot(const char *, const char *);
 120 static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
 121      __attribute__ ((noreturn, format (printf, 2, 3)));
 122 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 123
 124 #ifdef SIGINFO
 125 RETSIGTYPE requestinfo(int);
 126 #endif
 127
 128 #if defined(USE_WIN32_MM_TIMER)
 129   #include <MMsystem.h>
 130   static UINT timer_id;
 131   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
 132 #elif defined(HAVE_ALARM)
 133   static void verbose_stats_dump(int sig);
 134 #endif
 135
 136 static void info(int);
 137 static u_int packets_captured;
 138
 139 struct printer {
 140         if_printer f;
 141         int type;
 142 };
 143
 144
 145 struct ndo_printer {
 146         if_ndo_printer f;
 147         int type;
 148 };
 149
 150
 151 static struct printer printers[] = {
 152         { arcnet_if_print,      DLT_ARCNET },
 153 #ifdef DLT_ARCNET_LINUX
 154         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 155 #endif
 156         { token_if_print,       DLT_IEEE802 },
 157 #ifdef DLT_LANE8023
 158         { lane_if_print,        DLT_LANE8023 },
 159 #endif
 160 #ifdef DLT_CIP
 161         { cip_if_print,         DLT_CIP },
 162 #endif
 163 #ifdef DLT_ATM_CLIP
 164         { cip_if_print,         DLT_ATM_CLIP },
 165 #endif
 166         { sl_if_print,          DLT_SLIP },
 167 #ifdef DLT_SLIP_BSDOS
 168         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 169 #endif
 170         { ppp_if_print,         DLT_PPP },
 171 #ifdef DLT_PPP_WITHDIRECTION
 172         { ppp_if_print,         DLT_PPP_WITHDIRECTION },
 173 #endif
 174 #ifdef DLT_PPP_BSDOS
 175         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 176 #endif
 177         { fddi_if_print,        DLT_FDDI },
 178         { null_if_print,        DLT_NULL },
 179 #ifdef DLT_LOOP
 180         { null_if_print,        DLT_LOOP },
 181 #endif
 182         { raw_if_print,         DLT_RAW },
 183         { atm_if_print,         DLT_ATM_RFC1483 },
 184 #ifdef DLT_C_HDLC
 185         { chdlc_if_print,       DLT_C_HDLC },
 186 #endif
 187 #ifdef DLT_HDLC
 188         { chdlc_if_print,       DLT_HDLC },
 189 #endif
 190 #ifdef DLT_PPP_SERIAL
 191         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 192 #endif
 193 #ifdef DLT_PPP_ETHER
 194         { pppoe_if_print,       DLT_PPP_ETHER },
 195 #endif
 196 #ifdef DLT_LINUX_SLL
 197         { sll_if_print,         DLT_LINUX_SLL },
 198 #endif
 199 #ifdef DLT_IEEE802_11
 200         { ieee802_11_if_print,  DLT_IEEE802_11},
 201 #endif
 202 #ifdef DLT_LTALK
 203         { ltalk_if_print,       DLT_LTALK },
 204 #endif
 205 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
 206         { pflog_if_print,       DLT_PFLOG },
 207 #endif
 208 #ifdef DLT_FR
 209         { fr_if_print,          DLT_FR },
 210 #endif
 211 #ifdef DLT_FRELAY
 212         { fr_if_print,          DLT_FRELAY },
 213 #endif
 214 #ifdef DLT_SUNATM
 215         { sunatm_if_print,      DLT_SUNATM },
 216 #endif
 217 #ifdef DLT_IP_OVER_FC
 218         { ipfc_if_print,        DLT_IP_OVER_FC },
 219 #endif
 220 #ifdef DLT_PRISM_HEADER
 221         { prism_if_print,       DLT_PRISM_HEADER },
 222 #endif
 223 #ifdef DLT_IEEE802_11_RADIO
 224         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 225 #endif
 226 #ifdef DLT_ENC
 227         { enc_if_print,         DLT_ENC },
 228 #endif
 229 #ifdef DLT_SYMANTEC_FIREWALL
 230         { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
 231 #endif
 232 #ifdef DLT_APPLE_IP_OVER_IEEE1394
 233         { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
 234 #endif
 235 #ifdef DLT_IEEE802_11_RADIO_AVS
 236         { ieee802_11_radio_avs_if_print,        DLT_IEEE802_11_RADIO_AVS },
 237 #endif
 238 #ifdef DLT_JUNIPER_ATM1
 239         { juniper_atm1_print,   DLT_JUNIPER_ATM1 },
 240 #endif
 241 #ifdef DLT_JUNIPER_ATM2
 242         { juniper_atm2_print,   DLT_JUNIPER_ATM2 },
 243 #endif
 244 #ifdef DLT_JUNIPER_MFR
 245         { juniper_mfr_print,    DLT_JUNIPER_MFR },
 246 #endif
 247 #ifdef DLT_JUNIPER_MLFR
 248         { juniper_mlfr_print,   DLT_JUNIPER_MLFR },
 249 #endif
 250 #ifdef DLT_JUNIPER_MLPPP
 251         { juniper_mlppp_print,  DLT_JUNIPER_MLPPP },
 252 #endif
 253 #ifdef DLT_JUNIPER_PPPOE
 254         { juniper_pppoe_print,  DLT_JUNIPER_PPPOE },
 255 #endif
 256 #ifdef DLT_JUNIPER_PPPOE_ATM
 257         { juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
 258 #endif
 259 #ifdef DLT_JUNIPER_GGSN
 260         { juniper_ggsn_print,   DLT_JUNIPER_GGSN },
 261 #endif
 262 #ifdef DLT_JUNIPER_ES
 263         { juniper_es_print,     DLT_JUNIPER_ES },
 264 #endif
 265 #ifdef DLT_JUNIPER_MONITOR
 266         { juniper_monitor_print, DLT_JUNIPER_MONITOR },
 267 #endif
 268 #ifdef DLT_JUNIPER_SERVICES
 269         { juniper_services_print, DLT_JUNIPER_SERVICES },
 270 #endif
 271 #ifdef DLT_JUNIPER_ETHER
 272         { juniper_ether_print,  DLT_JUNIPER_ETHER },
 273 #endif
 274 #ifdef DLT_JUNIPER_PPP
 275         { juniper_ppp_print,    DLT_JUNIPER_PPP },
 276 #endif
 277 #ifdef DLT_JUNIPER_FRELAY
 278         { juniper_frelay_print, DLT_JUNIPER_FRELAY },
 279 #endif
 280 #ifdef DLT_JUNIPER_CHDLC
 281         { juniper_chdlc_print,  DLT_JUNIPER_CHDLC },
 282 #endif
 283 #ifdef DLT_MFR
 284         { mfr_if_print,         DLT_MFR },
 285 #endif
 286 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
 287         { bt_if_print,          DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
 288 #endif
 289 #ifdef HAVE_PCAP_USB_H
 290 #ifdef DLT_USB_LINUX
 291         { usb_linux_48_byte_print, DLT_USB_LINUX},
 292 #endif /* DLT_USB_LINUX */
 293 #ifdef DLT_USB_LINUX_MMAPPED
 294         { usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
 295 #endif /* DLT_USB_LINUX_MMAPPED */
 296 #endif /* HAVE_PCAP_USB_H */
 297 #ifdef DLT_IPV4
 298         { raw_if_print,         DLT_IPV4 },
 299 #endif
 300 #ifdef DLT_IPV6
 301         { raw_if_print,         DLT_IPV6 },
 302 #endif
 303         { NULL,                 0 },
 304 };
 305
 306 static struct ndo_printer ndo_printers[] = {
 307         { ether_if_print,       DLT_EN10MB },
 308 #ifdef DLT_IPNET
 309         { ipnet_if_print,       DLT_IPNET },
 310 #endif
 311 #ifdef DLT_IEEE802_15_4
 312         { ieee802_15_4_if_print, DLT_IEEE802_15_4 },
 313 #endif
 314 #ifdef DLT_IEEE802_15_4_NOFCS
 315         { ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
 316 #endif
 317 #ifdef DLT_PPI
 318         { ppi_if_print,         DLT_PPI },
 319 #endif
 320 #ifdef DLT_NETANALYZER
 321         { netanalyzer_if_print, DLT_NETANALYZER },
 322 #endif
 323 #ifdef DLT_NETANALYZER_TRANSPARENT
 324         { netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
 325 #endif
 326         { NULL,                 0 },
 327 };
 328
 329 if_printer
 330 lookup_printer(int type)
 331 {
 332         struct printer *p;
 333
 334         for (p = printers; p->f; ++p)
 335                 if (type == p->type)
 336                         return p->f;
 337
 338         return NULL;
 339         /* NOTREACHED */
 340 }
 341
 342 if_ndo_printer
 343 lookup_ndo_printer(int type)
 344 {
 345         struct ndo_printer *p;
 346
 347         for (p = ndo_printers; p->f; ++p)
 348                 if (type == p->type)
 349                         return p->f;
 350
 351         return NULL;
 352         /* NOTREACHED */
 353 }
 354
 355 static pcap_t *pd;
 356
 357 static int supports_monitor_mode;
 358
 359 extern int optind;
 360 extern int opterr;
 361 extern char *optarg;
 362
 363 struct print_info {
 364         netdissect_options *ndo;
 365         union {
 366                 if_printer     printer;
 367                 if_ndo_printer ndo_printer;
 368         } p;
 369         int ndo_type;
 370 };
 371
 372 struct dump_info {
 373         char    *WFileName;
 374         char    *CurrentFileName;
 375         pcap_t  *pd;
 376         pcap_dumper_t *p;
 377 };
 378
 379 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 380 static void
 381 show_tstamp_types_and_exit(const char *device, pcap_t *pd)
 382 {
 383         int n_tstamp_types;
 384         int *tstamp_types = 0;
 385         const char *tstamp_type_name;
 386         int i;
 387
 388         n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
 389         if (n_tstamp_types < 0)
 390                 error("%s", pcap_geterr(pd));
 391
 392         if (n_tstamp_types == 0) {
 393                 fprintf(stderr, "Time stamp type cannot be set for %s\n",
 394                     device);
 395                 exit(0);
 396         }
 397         fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
 398             device);
 399         for (i = 0; i < n_tstamp_types; i++) {
 400                 tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
 401                 if (tstamp_type_name != NULL) {
 402                         (void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
 403                             pcap_tstamp_type_val_to_description(tstamp_types[i]));
 404                 } else {
 405                         (void) fprintf(stderr, "  %d\n", tstamp_types[i]);
 406                 }
 407         }
 408         pcap_free_tstamp_types(tstamp_types);
 409         exit(0);
 410 }
 411 #endif
 412
 413 static void
 414 show_dlts_and_exit(const char *device, pcap_t *pd)
 415 {
 416         int n_dlts;
 417         int *dlts = 0;
 418         const char *dlt_name;
 419
 420         n_dlts = pcap_list_datalinks(pd, &dlts);
 421         if (n_dlts < 0)
 422                 error("%s", pcap_geterr(pd));
 423         else if (n_dlts == 0 || !dlts)
 424                 error("No data link types.");
 425
 426         /*
 427          * If the interface is known to support monitor mode, indicate
 428          * whether these are the data link types available when not in
 429          * monitor mode, if -I wasn't specified, or when in monitor mode,
 430          * when -I was specified (the link-layer types available in
 431          * monitor mode might be different from the ones available when
 432          * not in monitor mode).
 433          */
 434         if (supports_monitor_mode)
 435                 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
 436                     device,
 437                     Iflag ? "when in monitor mode" : "when not in monitor mode");
 438         else
 439                 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
 440                     device);
 441
 442         while (--n_dlts >= 0) {
 443                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 444                 if (dlt_name != NULL) {
 445                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 446                             pcap_datalink_val_to_description(dlts[n_dlts]));
 447
 448                         /*
 449                          * OK, does tcpdump handle that type?
 450                          */
 451                         if (lookup_printer(dlts[n_dlts]) == NULL
 452                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
 453                                 (void) fprintf(stderr, " (printing not supported)");
 454                         fprintf(stderr, "\n");
 455                 } else {
 456                         (void) fprintf(stderr, "  DLT %d (printing not supported)\n",
 457                             dlts[n_dlts]);
 458                 }
 459         }
 460         pcap_free_datalinks(dlts);
 461         exit(0);
 462 }
 463
 464 /*
 465  * Set up flags that might or might not be supported depending on the
 466  * version of libpcap we're using.
 467  */
 468 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 469 #define B_FLAG          "B:"
 470 #define B_FLAG_USAGE    " [ -B size ]"
 471 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 472 #define B_FLAG
 473 #define B_FLAG_USAGE
 474 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 475
 476 #ifdef HAVE_PCAP_CREATE
 477 #define I_FLAG          "I"
 478 #else /* HAVE_PCAP_CREATE */
 479 #define I_FLAG
 480 #endif /* HAVE_PCAP_CREATE */
 481
 482 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 483 #define j_FLAG          "j:"
 484 #define j_FLAG_USAGE    " [ -j tstamptype ]"
 485 #define J_FLAG          "J"
 486 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 487 #define j_FLAG
 488 #define j_FLAG_USAGE
 489 #define J_FLAG
 490 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 491
 492 #ifdef HAVE_PCAP_FINDALLDEVS
 493 #ifndef HAVE_PCAP_IF_T
 494 #undef HAVE_PCAP_FINDALLDEVS
 495 #endif
 496 #endif
 497
 498 #ifdef HAVE_PCAP_FINDALLDEVS
 499 #define D_FLAG  "D"
 500 #else
 501 #define D_FLAG
 502 #endif
 503
 504 #ifdef HAVE_PCAP_DUMP_FLUSH
 505 #define U_FLAG  "U"
 506 #else
 507 #define U_FLAG
 508 #endif
 509
 510 #ifndef WIN32
 511 /* Drop root privileges and chroot if necessary */
 512 static void
 513 droproot(const char *username, const char *chroot_dir)
 514 {
 515         struct passwd *pw = NULL;
 516
 517         if (chroot_dir && !username) {
 518                 fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
 519                 exit(1);
 520         }
 521
 522         pw = getpwnam(username);
 523         if (pw) {
 524                 if (chroot_dir) {
 525                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
 526                                 fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
 527                                     chroot_dir, pcap_strerror(errno));
 528                                 exit(1);
 529                         }
 530                 }
 531                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 532                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
 533                         fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
 534                             username,
 535                             (unsigned long)pw->pw_uid,
 536                             (unsigned long)pw->pw_gid,
 537                             pcap_strerror(errno));
 538                         exit(1);
 539                 }
 540         }
 541         else {
 542                 fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
 543                     username);
 544                 exit(1);
 545         }
 546 }
 547 #endif /* WIN32 */
 548
 549 static int
 550 getWflagChars(int x)
 551 {
 552         int c = 0;
 553
 554         x -= 1;
 555         while (x > 0) {
 556                 c += 1;
 557                 x /= 10;
 558         }
 559
 560         return c;
 561 }
 562
 563
 564 static void
 565 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 566 {
 567         char *filename = malloc(NAME_MAX + 1);
 568
 569         /* Process with strftime if Gflag is set. */
 570         if (Gflag != 0) {
 571           struct tm *local_tm;
 572
 573           /* Convert Gflag_time to a usable format */
 574           if ((local_tm = localtime(&Gflag_time)) == NULL) {
 575                   error("MakeTimedFilename: localtime");
 576           }
 577
 578           /* There's no good way to detect an error in strftime since a return
 579            * value of 0 isn't necessarily failure.
 580            */
 581           strftime(filename, NAME_MAX, orig_name, local_tm);
 582         } else {
 583           strncpy(filename, orig_name, NAME_MAX);
 584         }
 585
 586         if (cnt == 0 && max_chars == 0)
 587                 strncpy(buffer, filename, NAME_MAX + 1);
 588         else
 589                 if (snprintf(buffer, NAME_MAX + 1, "%s%0*d", filename, max_chars, cnt) > NAME_MAX)
 590                   /* Report an error if the filename is too large */
 591                   error("too many output files or filename is too long (> %d)", NAME_MAX);
 592         free(filename);
 593 }
 594
 595 static int tcpdump_printf(netdissect_options *ndo _U_,
 596                           const char *fmt, ...)
 597 {
 598
 599   va_list args;
 600   int ret;
 601
 602   va_start(args, fmt);
 603   ret=vfprintf(stdout, fmt, args);
 604   va_end(args);
 605
 606   return ret;
 607 }
 608
 609 int
 610 main(int argc, char **argv)
 611 {
 612         register int cnt, op, i;
 613         bpf_u_int32 localnet, netmask;
 614         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 615         pcap_handler callback;
 616         int type;
 617         struct bpf_program fcode;
 618 #ifndef WIN32
 619         RETSIGTYPE (*oldhandler)(int);
 620 #endif
 621         struct print_info printinfo;
 622         struct dump_info dumpinfo;
 623         u_char *pcap_userdata;
 624         char ebuf[PCAP_ERRBUF_SIZE];
 625         char *username = NULL;
 626         char *chroot_dir = NULL;
 627 #ifdef HAVE_PCAP_FINDALLDEVS
 628         pcap_if_t *devpointer;
 629         int devnum;
 630 #endif
 631         int status;
 632 #ifdef WIN32
 633         if(wsockinit() != 0) return 1;
 634 #endif /* WIN32 */
 635
 636         jflag=-1;       /* not set */
 637         gndo->ndo_Oflag=1;
 638         gndo->ndo_Rflag=1;
 639         gndo->ndo_dlt=-1;
 640         gndo->ndo_default_print=ndo_default_print;
 641         gndo->ndo_printf=tcpdump_printf;
 642         gndo->ndo_error=ndo_error;
 643         gndo->ndo_warning=ndo_warning;
 644         gndo->ndo_snaplen = DEFAULT_SNAPLEN;
 645
 646         cnt = -1;
 647         device = NULL;
 648         infile = NULL;
 649         RFileName = NULL;
 650         WFileName = NULL;
 651         if ((cp = strrchr(argv[0], '/')) != NULL)
 652                 program_name = cp + 1;
 653         else
 654                 program_name = argv[0];
 655
 656         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 657                 error("%s", ebuf);
 658
 659 #ifdef LIBSMI
 660         smiInit("tcpdump");
 661 #endif
 662
 663         while (
 664             (op = getopt(argc, argv, "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:Yz:Z:")) != -1)
 665                 switch (op) {
 666
 667                 case 'a':
 668                         /* compatibility for old -a */
 669                         break;
 670
 671                 case 'A':
 672                         ++Aflag;
 673                         break;
 674
 675                 case 'b':
 676                         ++bflag;
 677                         break;
 678
 679 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 680                 case 'B':
 681                         Bflag = atoi(optarg)*1024;
 682                         if (Bflag <= 0)
 683                                 error("invalid packet buffer size %s", optarg);
 684                         break;
 685 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 686
 687                 case 'c':
 688                         cnt = atoi(optarg);
 689                         if (cnt <= 0)
 690                                 error("invalid packet count %s", optarg);
 691                         break;
 692
 693                 case 'C':
 694                         Cflag = atoi(optarg) * 1000000;
 695                         if (Cflag < 0)
 696                                 error("invalid file size %s", optarg);
 697                         break;
 698
 699                 case 'd':
 700                         ++dflag;
 701                         break;
 702
 703 #ifdef HAVE_PCAP_FINDALLDEVS
 704                 case 'D':
 705                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 706                                 error("%s", ebuf);
 707                         else {
 708                                 for (i = 0; devpointer != 0; i++) {
 709                                         printf("%d.%s", i+1, devpointer->name);
 710                                         if (devpointer->description != NULL)
 711                                                 printf(" (%s)", devpointer->description);
 712                                         printf("\n");
 713                                         devpointer = devpointer->next;
 714                                 }
 715                         }
 716                         return 0;
 717 #endif /* HAVE_PCAP_FINDALLDEVS */
 718
 719                 case 'L':
 720                         Lflag++;
 721                         break;
 722
 723                 case 'e':
 724                         ++eflag;
 725                         break;
 726
 727                 case 'E':
 728 #ifndef HAVE_LIBCRYPTO
 729                         warning("crypto code not compiled in");
 730 #endif
 731                         gndo->ndo_espsecret = optarg;
 732                         break;
 733
 734                 case 'f':
 735                         ++fflag;
 736                         break;
 737
 738                 case 'F':
 739                         infile = optarg;
 740                         break;
 741
 742                 case 'G':
 743                         Gflag = atoi(optarg);
 744                         if (Gflag < 0)
 745                                 error("invalid number of seconds %s", optarg);
 746
 747                         /* We will create one file initially. */
 748                         Gflag_count = 0;
 749
 750                         /* Grab the current time for rotation use. */
 751                         if ((Gflag_time = time(NULL)) == (time_t)-1) {
 752                                 error("main: can't get current time: %s",
 753                                     pcap_strerror(errno));
 754                         }
 755                         break;
 756
 757                 case 'h':
 758                         usage();
 759                         break;
 760
 761                 case 'H':
 762                         ++Hflag;
 763                         break;
 764
 765                 case 'i':
 766                         if (optarg[0] == '0' && optarg[1] == 0)
 767                                 error("Invalid adapter index");
 768
 769 #ifdef HAVE_PCAP_FINDALLDEVS
 770                         /*
 771                          * If the argument is a number, treat it as
 772                          * an index into the list of adapters, as
 773                          * printed by "tcpdump -D".
 774                          *
 775                          * This should be OK on UNIX systems, as interfaces
 776                          * shouldn't have names that begin with digits.
 777                          * It can be useful on Windows, where more than
 778                          * one interface can have the same name.
 779                          */
 780                         if ((devnum = atoi(optarg)) != 0) {
 781                                 if (devnum < 0)
 782                                         error("Invalid adapter index");
 783
 784                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 785                                         error("%s", ebuf);
 786                                 else {
 787                                         /*
 788                                          * Look for the devnum-th entry
 789                                          * in the list of devices
 790                                          * (1-based).
 791                                          */
 792                                         for (i = 0;
 793                                             i < devnum-1 && devpointer != NULL;
 794                                             i++, devpointer = devpointer->next)
 795                                                 ;
 796                                         if (devpointer == NULL)
 797                                                 error("Invalid adapter index");
 798                                 }
 799                                 device = devpointer->name;
 800                                 break;
 801                         }
 802 #endif /* HAVE_PCAP_FINDALLDEVS */
 803                         device = optarg;
 804                         break;
 805
 806 #ifdef HAVE_PCAP_CREATE
 807                 case 'I':
 808                         ++Iflag;
 809                         break;
 810 #endif /* HAVE_PCAP_CREATE */
 811
 812 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 813                 case 'j':
 814                         jflag = pcap_tstamp_type_name_to_val(optarg);
 815                         if (jflag < 0)
 816                                 error("invalid time stamp type %s", optarg);
 817                         break;
 818
 819                 case 'J':
 820                         Jflag++;
 821                         break;
 822 #endif
 823
 824                 case 'l':
 825 #ifdef WIN32
 826                         /*
 827                          * _IOLBF is the same as _IOFBF in Microsoft's C
 828                          * libraries; the only alternative they offer
 829                          * is _IONBF.
 830                          *
 831                          * XXX - this should really be checking for MSVC++,
 832                          * not WIN32, if, for example, MinGW has its own
 833                          * C library that is more UNIX-compatible.
 834                          */
 835                         setvbuf(stdout, NULL, _IONBF, 0);
 836 #else /* WIN32 */
 837 #ifdef HAVE_SETLINEBUF
 838                         setlinebuf(stdout);
 839 #else
 840                         setvbuf(stdout, NULL, _IOLBF, 0);
 841 #endif
 842 #endif /* WIN32 */
 843                         break;
 844
 845                 case 'K':
 846                         ++Kflag;
 847                         break;
 848
 849                 case 'm':
 850 #ifdef LIBSMI
 851                         if (smiLoadModule(optarg) == 0) {
 852                                 error("could not load MIB module %s", optarg);
 853                         }
 854                         sflag = 1;
 855 #else
 856                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 857                                       program_name, optarg);
 858                         (void)fprintf(stderr, "(no libsmi support)\n");
 859 #endif
 860                         break;
 861
 862                 case 'M':
 863                         /* TCP-MD5 shared secret */
 864 #ifndef HAVE_LIBCRYPTO
 865                         warning("crypto code not compiled in");
 866 #endif
 867                         sigsecret = optarg;
 868                         break;
 869
 870                 case 'n':
 871                         ++nflag;
 872                         break;
 873
 874                 case 'N':
 875                         ++Nflag;
 876                         break;
 877
 878                 case 'O':
 879                         Oflag = 0;
 880                         break;
 881
 882                 case 'p':
 883                         ++pflag;
 884                         break;
 885
 886                 case 'q':
 887                         ++qflag;
 888                         ++suppress_default_print;
 889                         break;
 890
 891                 case 'r':
 892                         RFileName = optarg;
 893                         break;
 894
 895                 case 'R':
 896                         Rflag = 0;
 897                         break;
 898
 899                 case 's': {
 900                         char *end;
 901
 902                         snaplen = strtol(optarg, &end, 0);
 903                         if (optarg == end || *end != '\0'
 904                             || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
 905                                 error("invalid snaplen %s", optarg);
 906                         else if (snaplen == 0)
 907                                 snaplen = MAXIMUM_SNAPLEN;
 908                         break;
 909                 }
 910
 911                 case 'S':
 912                         ++Sflag;
 913                         break;
 914
 915                 case 't':
 916                         ++tflag;
 917                         break;
 918
 919                 case 'T':
 920                         if (strcasecmp(optarg, "vat") == 0)
 921                                 packettype = PT_VAT;
 922                         else if (strcasecmp(optarg, "wb") == 0)
 923                                 packettype = PT_WB;
 924                         else if (strcasecmp(optarg, "rpc") == 0)
 925                                 packettype = PT_RPC;
 926                         else if (strcasecmp(optarg, "rtp") == 0)
 927                                 packettype = PT_RTP;
 928                         else if (strcasecmp(optarg, "rtcp") == 0)
 929                                 packettype = PT_RTCP;
 930                         else if (strcasecmp(optarg, "snmp") == 0)
 931                                 packettype = PT_SNMP;
 932                         else if (strcasecmp(optarg, "cnfp") == 0)
 933                                 packettype = PT_CNFP;
 934                         else if (strcasecmp(optarg, "tftp") == 0)
 935                                 packettype = PT_TFTP;
 936                         else if (strcasecmp(optarg, "aodv") == 0)
 937                                 packettype = PT_AODV;
 938                         else if (strcasecmp(optarg, "carp") == 0)
 939                                 packettype = PT_CARP;
 940                         else
 941                                 error("unknown packet type `%s'", optarg);
 942                         break;
 943
 944                 case 'u':
 945                         ++uflag;
 946                         break;
 947
 948 #ifdef HAVE_PCAP_DUMP_FLUSH
 949                 case 'U':
 950                         ++Uflag;
 951                         break;
 952 #endif
 953
 954                 case 'v':
 955                         ++vflag;
 956                         break;
 957
 958                 case 'w':
 959                         WFileName = optarg;
 960                         break;
 961
 962                 case 'W':
 963                         Wflag = atoi(optarg);
 964                         if (Wflag < 0)
 965                                 error("invalid number of output files %s", optarg);
 966                         WflagChars = getWflagChars(Wflag);
 967                         break;
 968
 969                 case 'x':
 970                         ++xflag;
 971                         ++suppress_default_print;
 972                         break;
 973
 974                 case 'X':
 975                         ++Xflag;
 976                         ++suppress_default_print;
 977                         break;
 978
 979                 case 'y':
 980                         gndo->ndo_dltname = optarg;
 981                         gndo->ndo_dlt =
 982                           pcap_datalink_name_to_val(gndo->ndo_dltname);
 983                         if (gndo->ndo_dlt < 0)
 984                                 error("invalid data link type %s", gndo->ndo_dltname);
 985                         break;
 986
 987 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 988                 case 'Y':
 989                         {
 990                         /* Undocumented flag */
 991 #ifdef HAVE_PCAP_DEBUG
 992                         extern int pcap_debug;
 993                         pcap_debug = 1;
 994 #else
 995                         extern int yydebug;
 996                         yydebug = 1;
 997 #endif
 998                         }
 999                         break;
1000 #endif
1001                 case 'z':
1002                         if (optarg) {
1003                                 zflag = strdup(optarg);
1004                         } else {
1005                                 usage();
1006                                 /* NOTREACHED */
1007                         }
1008                         break;
1009
1010                 case 'Z':
1011                         if (optarg) {
1012                                 username = strdup(optarg);
1013                         }
1014                         else {
1015                                 usage();
1016                                 /* NOTREACHED */
1017                         }
1018                         break;
1019
1020                 default:
1021                         usage();
1022                         /* NOTREACHED */
1023                 }
1024
1025         switch (tflag) {
1026
1027         case 0: /* Default */
1028         case 4: /* Default + Date*/
1029                 thiszone = gmt2local(0);
1030                 break;
1031
1032         case 1: /* No time stamp */
1033         case 2: /* Unix timeval style */
1034         case 3: /* Microseconds since previous packet */
1035         case 5: /* Microseconds since first packet */
1036                 break;
1037
1038         default: /* Not supported */
1039                 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1040                 break;
1041         }
1042
1043 #ifdef WITH_CHROOT
1044         /* if run as root, prepare for chrooting */
1045         if (getuid() == 0 || geteuid() == 0) {
1046                 /* future extensibility for cmd-line arguments */
1047                 if (!chroot_dir)
1048                         chroot_dir = WITH_CHROOT;
1049         }
1050 #endif
1051
1052 #ifdef WITH_USER
1053         /* if run as root, prepare for dropping root privileges */
1054         if (getuid() == 0 || geteuid() == 0) {
1055                 /* Run with '-Z root' to restore old behaviour */
1056                 if (!username)
1057                         username = WITH_USER;
1058         }
1059 #endif
1060
1061         if (RFileName != NULL) {
1062                 int dlt;
1063                 const char *dlt_name;
1064
1065 #ifndef WIN32
1066                 /*
1067                  * We don't need network access, so relinquish any set-UID
1068                  * or set-GID privileges we have (if any).
1069                  *
1070                  * We do *not* want set-UID privileges when opening a
1071                  * trace file, as that might let the user read other
1072                  * people's trace files (especially if we're set-UID
1073                  * root).
1074                  */
1075                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1076                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1077 #endif /* WIN32 */
1078                 pd = pcap_open_offline(RFileName, ebuf);
1079                 if (pd == NULL)
1080                         error("%s", ebuf);
1081                 dlt = pcap_datalink(pd);
1082                 dlt_name = pcap_datalink_val_to_name(dlt);
1083                 if (dlt_name == NULL) {
1084                         fprintf(stderr, "reading from file %s, link-type %u\n",
1085                             RFileName, dlt);
1086                 } else {
1087                         fprintf(stderr,
1088                             "reading from file %s, link-type %s (%s)\n",
1089                             RFileName, dlt_name,
1090                             pcap_datalink_val_to_description(dlt));
1091                 }
1092                 localnet = 0;
1093                 netmask = 0;
1094                 if (fflag != 0)
1095                         error("-f and -r options are incompatible");
1096         } else {
1097                 if (device == NULL) {
1098                         device = pcap_lookupdev(ebuf);
1099                         if (device == NULL)
1100                                 error("%s", ebuf);
1101                 }
1102 #ifdef WIN32
1103                 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
1104                 {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
1105                         fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1106                 }
1107                 else
1108                 {
1109                         fprintf(stderr, "%s: listening on %s\n", program_name, device);
1110                 }
1111
1112                 fflush(stderr);
1113 #endif /* WIN32 */
1114 #ifdef HAVE_PCAP_CREATE
1115                 pd = pcap_create(device, ebuf);
1116                 if (pd == NULL)
1117                         error("%s", ebuf);
1118 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1119                 if (Jflag)
1120                         show_tstamp_types_and_exit(device, pd);
1121 #endif
1122                 /*
1123                  * Is this an interface that supports monitor mode?
1124                  */
1125                 if (pcap_can_set_rfmon(pd) == 1)
1126                         supports_monitor_mode = 1;
1127                 else
1128                         supports_monitor_mode = 0;
1129                 status = pcap_set_snaplen(pd, snaplen);
1130                 if (status != 0)
1131                         error("%s: Can't set snapshot length: %s",
1132                             device, pcap_statustostr(status));
1133                 status = pcap_set_promisc(pd, !pflag);
1134                 if (status != 0)
1135                         error("%s: Can't set promiscuous mode: %s",
1136                             device, pcap_statustostr(status));
1137                 if (Iflag) {
1138                         status = pcap_set_rfmon(pd, 1);
1139                         if (status != 0)
1140                                 error("%s: Can't set monitor mode: %s",
1141                                     device, pcap_statustostr(status));
1142                 }
1143                 status = pcap_set_timeout(pd, 1000);
1144                 if (status != 0)
1145                         error("%s: pcap_set_timeout failed: %s",
1146                             device, pcap_statustostr(status));
1147                 if (Bflag != 0) {
1148                         status = pcap_set_buffer_size(pd, Bflag);
1149                         if (status != 0)
1150                                 error("%s: Can't set buffer size: %s",
1151                                     device, pcap_statustostr(status));
1152                 }
1153 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1154                 if (jflag != -1) {
1155                         status = pcap_set_tstamp_type(pd, jflag);
1156                         if (status < 0)
1157                                 error("%s: Can't set time stamp type: %s",
1158                                     device, pcap_statustostr(status));
1159                 }
1160 #endif
1161                 status = pcap_activate(pd);
1162                 if (status < 0) {
1163                         /*
1164                          * pcap_activate() failed.
1165                          */
1166                         cp = pcap_geterr(pd);
1167                         if (status == PCAP_ERROR)
1168                                 error("%s", cp);
1169                         else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1170                                   status == PCAP_ERROR_PERM_DENIED) &&
1171                                  *cp != '\0')
1172                                 error("%s: %s\n(%s)", device,
1173                                     pcap_statustostr(status), cp);
1174                         else
1175                                 error("%s: %s", device,
1176                                     pcap_statustostr(status));
1177                 } else if (status > 0) {
1178                         /*
1179                          * pcap_activate() succeeded, but it's warning us
1180                          * of a problem it had.
1181                          */
1182                         cp = pcap_geterr(pd);
1183                         if (status == PCAP_WARNING)
1184                                 warning("%s", cp);
1185                         else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1186                                  *cp != '\0')
1187                                 warning("%s: %s\n(%s)", device,
1188                                     pcap_statustostr(status), cp);
1189                         else
1190                                 warning("%s: %s", device,
1191                                     pcap_statustostr(status));
1192                 }
1193 #else
1194                 *ebuf = '\0';
1195                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1196                 if (pd == NULL)
1197                         error("%s", ebuf);
1198                 else if (*ebuf)
1199                         warning("%s", ebuf);
1200 #endif /* HAVE_PCAP_CREATE */
1201                 /*
1202                  * Let user own process after socket has been opened.
1203                  */
1204 #ifndef WIN32
1205                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1206                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1207 #endif /* WIN32 */
1208 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1209                 if(Bflag != 0)
1210                         if(pcap_setbuff(pd, Bflag)==-1){
1211                                 error("%s", pcap_geterr(pd));
1212                         }
1213 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1214                 if (Lflag)
1215                         show_dlts_and_exit(device, pd);
1216                 if (gndo->ndo_dlt >= 0) {
1217 #ifdef HAVE_PCAP_SET_DATALINK
1218                         if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1219                                 error("%s", pcap_geterr(pd));
1220 #else
1221                         /*
1222                          * We don't actually support changing the
1223                          * data link type, so we only let them
1224                          * set it to what it already is.
1225                          */
1226                         if (gndo->ndo_dlt != pcap_datalink(pd)) {
1227                                 error("%s is not one of the DLTs supported by this device\n",
1228                                       gndo->ndo_dltname);
1229                         }
1230 #endif
1231                         (void)fprintf(stderr, "%s: data link type %s\n",
1232                                       program_name, gndo->ndo_dltname);
1233                         (void)fflush(stderr);
1234                 }
1235                 i = pcap_snapshot(pd);
1236                 if (snaplen < i) {
1237                         warning("snaplen raised from %d to %d", snaplen, i);
1238                         snaplen = i;
1239                 }
1240                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1241                         localnet = 0;
1242                         netmask = 0;
1243                         warning("%s", ebuf);
1244                 }
1245         }
1246         if (infile)
1247                 cmdbuf = read_infile(infile);
1248         else
1249                 cmdbuf = copy_argv(&argv[optind]);
1250
1251         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1252                 error("%s", pcap_geterr(pd));
1253         free(cmdbuf);
1254         if (dflag) {
1255                 bpf_dump(&fcode, dflag);
1256                 pcap_close(pd);
1257                 exit(0);
1258         }
1259         init_addrtoname(localnet, netmask);
1260         init_checksum();
1261
1262 #ifndef WIN32
1263         (void)setsignal(SIGPIPE, cleanup);
1264         (void)setsignal(SIGTERM, cleanup);
1265         (void)setsignal(SIGINT, cleanup);
1266 #endif /* WIN32 */
1267 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1268         (void)setsignal(SIGCHLD, child_cleanup);
1269 #endif
1270         /* Cooperate with nohup(1) */
1271 #ifndef WIN32
1272         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1273                 (void)setsignal(SIGHUP, oldhandler);
1274 #endif /* WIN32 */
1275
1276 #ifndef WIN32
1277         /*
1278          * If a user name was specified with "-Z", attempt to switch to
1279          * that user's UID.  This would probably be used with sudo,
1280          * to allow tcpdump to be run in a special restricted
1281          * account (if you just want to allow users to open capture
1282          * devices, and can't just give users that permission,
1283          * you'd make tcpdump set-UID or set-GID).
1284          *
1285          * Tcpdump doesn't necessarily write only to one savefile;
1286          * the general only way to allow a -Z instance to write to
1287          * savefiles as the user under whose UID it's run, rather
1288          * than as the user specified with -Z, would thus be to switch
1289          * to the original user ID before opening a capture file and
1290          * then switch back to the -Z user ID after opening the savefile.
1291          * Switching to the -Z user ID only after opening the first
1292          * savefile doesn't handle the general case.
1293          */
1294         if (getuid() == 0 || geteuid() == 0) {
1295                 if (username || chroot_dir)
1296                         droproot(username, chroot_dir);
1297         }
1298 #endif /* WIN32 */
1299
1300         if (pcap_setfilter(pd, &fcode) < 0)
1301                 error("%s", pcap_geterr(pd));
1302         if (WFileName) {
1303                 pcap_dumper_t *p;
1304                 /* Do not exceed the default NAME_MAX for files. */
1305                 dumpinfo.CurrentFileName = (char *)malloc(NAME_MAX + 1);
1306
1307                 if (dumpinfo.CurrentFileName == NULL)
1308                         error("malloc of dumpinfo.CurrentFileName");
1309
1310                 /* We do not need numbering for dumpfiles if Cflag isn't set. */
1311                 if (Cflag != 0)
1312                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1313                 else
1314                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1315
1316                 p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1317                 if (p == NULL)
1318                         error("%s", pcap_geterr(pd));
1319                 if (Cflag != 0 || Gflag != 0) {
1320                         callback = dump_packet_and_trunc;
1321                         dumpinfo.WFileName = WFileName;
1322                         dumpinfo.pd = pd;
1323                         dumpinfo.p = p;
1324                         pcap_userdata = (u_char *)&dumpinfo;
1325                 } else {
1326                         callback = dump_packet;
1327                         pcap_userdata = (u_char *)p;
1328                 }
1329 #ifdef HAVE_PCAP_DUMP_FLUSH
1330                 if (Uflag)
1331                         pcap_dump_flush(p);
1332 #endif
1333         } else {
1334                 type = pcap_datalink(pd);
1335                 printinfo.ndo_type = 1;
1336                 printinfo.ndo = gndo;
1337                 printinfo.p.ndo_printer = lookup_ndo_printer(type);
1338                 if (printinfo.p.ndo_printer == NULL) {
1339                         printinfo.p.printer = lookup_printer(type);
1340                         printinfo.ndo_type = 0;
1341                         if (printinfo.p.printer == NULL) {
1342                                 gndo->ndo_dltname = pcap_datalink_val_to_name(type);
1343                                 if (gndo->ndo_dltname != NULL)
1344                                         error("packet printing is not supported for link type %s: use -w",
1345                                               gndo->ndo_dltname);
1346                                 else
1347                                         error("packet printing is not supported for link type %d: use -w", type);
1348                         }
1349                 }
1350                 callback = print_packet;
1351                 pcap_userdata = (u_char *)&printinfo;
1352         }
1353
1354 #ifdef SIGINFO
1355         /*
1356          * We can't get statistics when reading from a file rather
1357          * than capturing from a device.
1358          */
1359         if (RFileName == NULL)
1360                 (void)setsignal(SIGINFO, requestinfo);
1361 #endif
1362
1363         if (vflag > 0 && WFileName) {
1364                 /*
1365                  * When capturing to a file, "-v" means tcpdump should,
1366                  * every 10 secodns, "v"erbosely report the number of
1367                  * packets captured.
1368                  */
1369 #ifdef USE_WIN32_MM_TIMER
1370                 /* call verbose_stats_dump() each 1000 +/-100msec */
1371                 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1372                 setvbuf(stderr, NULL, _IONBF, 0);
1373 #elif defined(HAVE_ALARM)
1374                 (void)setsignal(SIGALRM, verbose_stats_dump);
1375                 alarm(1);
1376 #endif
1377         }
1378
1379 #ifndef WIN32
1380         if (RFileName == NULL) {
1381                 int dlt;
1382                 const char *dlt_name;
1383
1384                 if (!vflag && !WFileName) {
1385                         (void)fprintf(stderr,
1386                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1387                             program_name);
1388                 } else
1389                         (void)fprintf(stderr, "%s: ", program_name);
1390                 dlt = pcap_datalink(pd);
1391                 dlt_name = pcap_datalink_val_to_name(dlt);
1392                 if (dlt_name == NULL) {
1393                         (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1394                             device, dlt, snaplen);
1395                 } else {
1396                         (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1397                             device, dlt_name,
1398                             pcap_datalink_val_to_description(dlt), snaplen);
1399                 }
1400                 (void)fflush(stderr);
1401         }
1402 #endif /* WIN32 */
1403         status = pcap_loop(pd, cnt, callback, pcap_userdata);
1404         if (WFileName == NULL) {
1405                 /*
1406                  * We're printing packets.  Flush the printed output,
1407                  * so it doesn't get intermingled with error output.
1408                  */
1409                 if (status == -2) {
1410                         /*
1411                          * We got interrupted, so perhaps we didn't
1412                          * manage to finish a line we were printing.
1413                          * Print an extra newline, just in case.
1414                          */
1415                         putchar('\n');
1416                 }
1417                 (void)fflush(stdout);
1418         }
1419         if (status == -1) {
1420                 /*
1421                  * Error.  Report it.
1422                  */
1423                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
1424                     program_name, pcap_geterr(pd));
1425         }
1426         if (RFileName == NULL) {
1427                 /*
1428                  * We're doing a live capture.  Report the capture
1429                  * statistics.
1430                  */
1431                 info(1);
1432         }
1433         pcap_close(pd);
1434         exit(status == -1 ? 1 : 0);
1435 }
1436
1437 /* make a clean exit on interrupts */
1438 static RETSIGTYPE
1439 cleanup(int signo _U_)
1440 {
1441 #ifdef USE_WIN32_MM_TIMER
1442         if (timer_id)
1443                 timeKillEvent(timer_id);
1444         timer_id = 0;
1445 #elif defined(HAVE_ALARM)
1446         alarm(0);
1447 #endif
1448
1449 #ifdef HAVE_PCAP_BREAKLOOP
1450         /*
1451          * We have "pcap_breakloop()"; use it, so that we do as little
1452          * as possible in the signal handler (it's probably not safe
1453          * to do anything with standard I/O streams in a signal handler -
1454          * the ANSI C standard doesn't say it is).
1455          */
1456         pcap_breakloop(pd);
1457 #else
1458         /*
1459          * We don't have "pcap_breakloop()"; this isn't safe, but
1460          * it's the best we can do.  Print the summary if we're
1461          * not reading from a savefile - i.e., if we're doing a
1462          * live capture - and exit.
1463          */
1464         if (pd != NULL && pcap_file(pd) == NULL) {
1465                 /*
1466                  * We got interrupted, so perhaps we didn't
1467                  * manage to finish a line we were printing.
1468                  * Print an extra newline, just in case.
1469                  */
1470                 putchar('\n');
1471                 (void)fflush(stdout);
1472                 info(1);
1473         }
1474         exit(0);
1475 #endif
1476 }
1477
1478 /*
1479   On windows, we do not use a fork, so we do not care less about
1480   waiting a child processes to die
1481  */
1482 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1483 static RETSIGTYPE
1484 child_cleanup(int signo _U_)
1485 {
1486   wait(NULL);
1487 }
1488 #endif /* HAVE_FORK && HAVE_VFORK */
1489
1490 static void
1491 info(register int verbose)
1492 {
1493         struct pcap_stat stat;
1494
1495         /*
1496          * Older versions of libpcap didn't set ps_ifdrop on some
1497          * platforms; initialize it to 0 to handle that.
1498          */
1499         stat.ps_ifdrop = 0;
1500         if (pcap_stats(pd, &stat) < 0) {
1501                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1502                 infoprint = 0;
1503                 return;
1504         }
1505
1506         if (!verbose)
1507                 fprintf(stderr, "%s: ", program_name);
1508
1509         (void)fprintf(stderr, "%u packet%s captured", packets_captured,
1510             PLURAL_SUFFIX(packets_captured));
1511         if (!verbose)
1512                 fputs(", ", stderr);
1513         else
1514                 putc('\n', stderr);
1515         (void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
1516             PLURAL_SUFFIX(stat.ps_recv));
1517         if (!verbose)
1518                 fputs(", ", stderr);
1519         else
1520                 putc('\n', stderr);
1521         (void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
1522             PLURAL_SUFFIX(stat.ps_drop));
1523         if (stat.ps_ifdrop != 0) {
1524                 if (!verbose)
1525                         fputs(", ", stderr);
1526                 else
1527                         putc('\n', stderr);
1528                 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
1529                     stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
1530         } else
1531                 putc('\n', stderr);
1532         infoprint = 0;
1533 }
1534
1535 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1536 static void
1537 compress_savefile(const char *filename)
1538 {
1539 # ifdef HAVE_FORK
1540         if (fork())
1541 # else
1542         if (vfork())
1543 # endif
1544                 return;
1545         /*
1546          * Set to lowest priority so that this doesn't disturb the capture
1547          */
1548 #ifdef NZERO
1549         setpriority(PRIO_PROCESS, 0, NZERO - 1);
1550 #else
1551         setpriority(PRIO_PROCESS, 0, 19);
1552 #endif
1553         if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
1554                 fprintf(stderr,
1555                         "compress_savefile:execlp(%s, %s): %s\n",
1556                         zflag,
1557                         filename,
1558                         strerror(errno));
1559 # ifdef HAVE_FORK
1560         exit(1);
1561 # else
1562         _exit(1);
1563 # endif
1564 }
1565 #else  /* HAVE_FORK && HAVE_VFORK */
1566 static void
1567 compress_savefile(const char *filename)
1568 {
1569         fprintf(stderr,
1570                 "compress_savefile failed. Functionality not implemented under your system\n");
1571 }
1572 #endif /* HAVE_FORK && HAVE_VFORK */
1573
1574 static void
1575 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1576 {
1577         struct dump_info *dump_info;
1578
1579         ++packets_captured;
1580
1581         ++infodelay;
1582
1583         dump_info = (struct dump_info *)user;
1584
1585         /*
1586          * XXX - this won't force the file to rotate on the specified time
1587          * boundary, but it will rotate on the first packet received after the
1588          * specified Gflag number of seconds. Note: if a Gflag time boundary
1589          * and a Cflag size boundary coincide, the time rotation will occur
1590          * first thereby cancelling the Cflag boundary (since the file should
1591          * be 0).
1592          */
1593         if (Gflag != 0) {
1594                 /* Check if it is time to rotate */
1595                 time_t t;
1596
1597                 /* Get the current time */
1598                 if ((t = time(NULL)) == (time_t)-1) {
1599                         error("dump_and_trunc_packet: can't get current_time: %s",
1600                             pcap_strerror(errno));
1601                 }
1602
1603
1604                 /* If the time is greater than the specified window, rotate */
1605                 if (t - Gflag_time >= Gflag) {
1606                         /* Update the Gflag_time */
1607                         Gflag_time = t;
1608                         /* Update Gflag_count */
1609                         Gflag_count++;
1610                         /*
1611                          * Close the current file and open a new one.
1612                          */
1613                         pcap_dump_close(dump_info->p);
1614
1615                         /*
1616                          * Compress the file we just closed, if the user asked for it
1617                          */
1618                         if (zflag != NULL)
1619                                 compress_savefile(dump_info->CurrentFileName);
1620
1621                         /*
1622                          * Check to see if we've exceeded the Wflag (when
1623                          * not using Cflag).
1624                          */
1625                         if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
1626                                 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
1627                                     Wflag);
1628                                 exit(0);
1629                                 /* NOTREACHED */
1630                         }
1631                         if (dump_info->CurrentFileName != NULL)
1632                                 free(dump_info->CurrentFileName);
1633                         /* Allocate space for max filename + \0. */
1634                         dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1635                         if (dump_info->CurrentFileName == NULL)
1636                                 error("dump_packet_and_trunc: malloc");
1637                         /*
1638                          * This is always the first file in the Cflag
1639                          * rotation: e.g. 0
1640                          * We also don't need numbering if Cflag is not set.
1641                          */
1642                         if (Cflag != 0)
1643                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
1644                                     WflagChars);
1645                         else
1646                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
1647
1648                         dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1649                         if (dump_info->p == NULL)
1650                                 error("%s", pcap_geterr(pd));
1651                 }
1652         }
1653
1654         /*
1655          * XXX - this won't prevent capture files from getting
1656          * larger than Cflag - the last packet written to the
1657          * file could put it over Cflag.
1658          */
1659         if (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) {
1660                 /*
1661                  * Close the current file and open a new one.
1662                  */
1663                 pcap_dump_close(dump_info->p);
1664
1665                 /*
1666                  * Compress the file we just closed, if the user asked for it
1667                  */
1668                 if (zflag != NULL)
1669                         compress_savefile(dump_info->CurrentFileName);
1670
1671                 Cflag_count++;
1672                 if (Wflag > 0) {
1673                         if (Cflag_count >= Wflag)
1674                                 Cflag_count = 0;
1675                 }
1676                 if (dump_info->CurrentFileName != NULL)
1677                         free(dump_info->CurrentFileName);
1678                 dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1679                 if (dump_info->CurrentFileName == NULL)
1680                         error("dump_packet_and_trunc: malloc");
1681                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
1682                 dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1683                 if (dump_info->p == NULL)
1684                         error("%s", pcap_geterr(pd));
1685         }
1686
1687         pcap_dump((u_char *)dump_info->p, h, sp);
1688 #ifdef HAVE_PCAP_DUMP_FLUSH
1689         if (Uflag)
1690                 pcap_dump_flush(dump_info->p);
1691 #endif
1692
1693         --infodelay;
1694         if (infoprint)
1695                 info(0);
1696 }
1697
1698 static void
1699 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1700 {
1701         ++packets_captured;
1702
1703         ++infodelay;
1704
1705         pcap_dump(user, h, sp);
1706 #ifdef HAVE_PCAP_DUMP_FLUSH
1707         if (Uflag)
1708                 pcap_dump_flush((pcap_dumper_t *)user);
1709 #endif
1710
1711         --infodelay;
1712         if (infoprint)
1713                 info(0);
1714 }
1715
1716 static void
1717 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1718 {
1719         struct print_info *print_info;
1720         u_int hdrlen;
1721
1722         ++packets_captured;
1723
1724         ++infodelay;
1725         ts_print(&h->ts);
1726
1727         print_info = (struct print_info *)user;
1728
1729         /*
1730          * Some printers want to check that they're not walking off the
1731          * end of the packet.
1732          * Rather than pass it all the way down, we set this global.
1733          */
1734         snapend = sp + h->caplen;
1735
1736         if(print_info->ndo_type) {
1737                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
1738         } else {
1739                 hdrlen = (*print_info->p.printer)(h, sp);
1740         }
1741
1742         if (Xflag) {
1743                 /*
1744                  * Print the raw packet data in hex and ASCII.
1745                  */
1746                 if (Xflag > 1) {
1747                         /*
1748                          * Include the link-layer header.
1749                          */
1750                         hex_and_ascii_print("\n\t", sp, h->caplen);
1751                 } else {
1752                         /*
1753                          * Don't include the link-layer header - and if
1754                          * we have nothing past the link-layer header,
1755                          * print nothing.
1756                          */
1757                         if (h->caplen > hdrlen)
1758                                 hex_and_ascii_print("\n\t", sp + hdrlen,
1759                                     h->caplen - hdrlen);
1760                 }
1761         } else if (xflag) {
1762                 /*
1763                  * Print the raw packet data in hex.
1764                  */
1765                 if (xflag > 1) {
1766                         /*
1767                          * Include the link-layer header.
1768                          */
1769                         hex_print("\n\t", sp, h->caplen);
1770                 } else {
1771                         /*
1772                          * Don't include the link-layer header - and if
1773                          * we have nothing past the link-layer header,
1774                          * print nothing.
1775                          */
1776                         if (h->caplen > hdrlen)
1777                                 hex_print("\n\t", sp + hdrlen,
1778                                     h->caplen - hdrlen);
1779                 }
1780         } else if (Aflag) {
1781                 /*
1782                  * Print the raw packet data in ASCII.
1783                  */
1784                 if (Aflag > 1) {
1785                         /*
1786                          * Include the link-layer header.
1787                          */
1788                         ascii_print(sp, h->caplen);
1789                 } else {
1790                         /*
1791                          * Don't include the link-layer header - and if
1792                          * we have nothing past the link-layer header,
1793                          * print nothing.
1794                          */
1795                         if (h->caplen > hdrlen)
1796                                 ascii_print(sp + hdrlen, h->caplen - hdrlen);
1797                 }
1798         }
1799
1800         putchar('\n');
1801
1802         --infodelay;
1803         if (infoprint)
1804                 info(0);
1805 }
1806
1807 #ifdef WIN32
1808         /*
1809          * XXX - there should really be libpcap calls to get the version
1810          * number as a string (the string would be generated from #defines
1811          * at run time, so that it's not generated from string constants
1812          * in the library, as, on many UNIX systems, those constants would
1813          * be statically linked into the application executable image, and
1814          * would thus reflect the version of libpcap on the system on
1815          * which the application was *linked*, not the system on which it's
1816          * *running*.
1817          *
1818          * That routine should be documented, unlike the "version[]"
1819          * string, so that UNIX vendors providing their own libpcaps
1820          * don't omit it (as a couple of vendors have...).
1821          *
1822          * Packet.dll should perhaps also export a routine to return the
1823          * version number of the Packet.dll code, to supply the
1824          * "Wpcap_version" information on Windows.
1825          */
1826         char WDversion[]="current-cvs.tcpdump.org";
1827 #if !defined(HAVE_GENERATED_VERSION)
1828         char version[]="current-cvs.tcpdump.org";
1829 #endif
1830         char pcap_version[]="current-cvs.tcpdump.org";
1831         char Wpcap_version[]="3.1";
1832 #endif
1833
1834 /*
1835  * By default, print the specified data out in hex and ASCII.
1836  */
1837 static void
1838 ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
1839 {
1840         hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1841 }
1842
1843 void
1844 default_print(const u_char *bp, u_int length)
1845 {
1846         ndo_default_print(gndo, bp, length);
1847 }
1848
1849 #ifdef SIGINFO
1850 RETSIGTYPE requestinfo(int signo _U_)
1851 {
1852         if (infodelay)
1853                 ++infoprint;
1854         else
1855                 info(0);
1856 }
1857 #endif
1858
1859 /*
1860  * Called once each second in verbose mode while dumping to file
1861  */
1862 #ifdef USE_WIN32_MM_TIMER
1863 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
1864                                   DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
1865 {
1866         struct pcap_stat stat;
1867
1868         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1869                 fprintf(stderr, "Got %u\r", packets_captured);
1870 }
1871 #elif defined(HAVE_ALARM)
1872 static void verbose_stats_dump(int sig _U_)
1873 {
1874         struct pcap_stat stat;
1875
1876         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1877                 fprintf(stderr, "Got %u\r", packets_captured);
1878         alarm(1);
1879 }
1880 #endif
1881
1882 static void
1883 usage(void)
1884 {
1885         extern char version[];
1886 #ifndef HAVE_PCAP_LIB_VERSION
1887 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1888         extern char pcap_version[];
1889 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1890         static char pcap_version[] = "unknown";
1891 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1892 #endif /* HAVE_PCAP_LIB_VERSION */
1893
1894 #ifdef HAVE_PCAP_LIB_VERSION
1895 #ifdef WIN32
1896         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1897 #else /* WIN32 */
1898         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1899 #endif /* WIN32 */
1900         (void)fprintf(stderr, "%s\n",pcap_lib_version());
1901 #else /* HAVE_PCAP_LIB_VERSION */
1902 #ifdef WIN32
1903         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1904         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1905 #else /* WIN32 */
1906         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1907         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1908 #endif /* WIN32 */
1909 #endif /* HAVE_PCAP_LIB_VERSION */
1910         (void)fprintf(stderr,
1911 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
1912         (void)fprintf(stderr,
1913 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
1914         (void)fprintf(stderr,
1915 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ]\n");
1916         (void)fprintf(stderr,
1917 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ]\n");
1918         (void)fprintf(stderr,
1919 "\t\t[ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
1920         (void)fprintf(stderr,
1921 "\t\t[ -Z user ] [ expression ]\n");
1922         exit(1);
1923 }
1924
1925
1926
1927 /* VARARGS */
1928 static void
1929 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
1930 {
1931         va_list ap;
1932
1933         (void)fprintf(stderr, "%s: ", program_name);
1934         va_start(ap, fmt);
1935         (void)vfprintf(stderr, fmt, ap);
1936         va_end(ap);
1937         if (*fmt) {
1938                 fmt += strlen(fmt);
1939                 if (fmt[-1] != '\n')
1940                         (void)fputc('\n', stderr);
1941         }
1942         exit(1);
1943         /* NOTREACHED */
1944 }
1945
1946 /* VARARGS */
1947 static void
1948 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
1949 {
1950         va_list ap;
1951
1952         (void)fprintf(stderr, "%s: WARNING: ", program_name);
1953         va_start(ap, fmt);
1954         (void)vfprintf(stderr, fmt, ap);
1955         va_end(ap);
1956         if (*fmt) {
1957                 fmt += strlen(fmt);
1958                 if (fmt[-1] != '\n')
1959                         (void)fputc('\n', stderr);
1960         }
1961 }