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 /*
  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 #include <limits.h>
  69 #ifndef WIN32
  70 #include <sys/wait.h>
  71 #include <sys/resource.h>
  72 #include <pwd.h>
  73 #include <grp.h>
  74 #include <errno.h>
  75 #endif /* WIN32 */
  76
  77
  78 #include "netdissect.h"
  79 #include "interface.h"
  80 #include "addrtoname.h"
  81 #include "machdep.h"
  82 #include "setsignal.h"
  83 #include "gmt2local.h"
  84 #include "pcap-missing.h"
  85
  86 #ifndef NAME_MAX
  87 #define NAME_MAX 255
  88 #endif
  89
  90 #ifdef SIGINFO
  91 #define SIGNAL_REQ_INFO SIGINFO
  92 #elif SIGUSR1
  93 #define SIGNAL_REQ_INFO SIGUSR1
  94 #endif
  95
  96 netdissect_options Gndo;
  97 netdissect_options *gndo = &Gndo;
  98
  99 static int dflag;                       /* print filter code */
 100 static int Lflag;                       /* list available data link types and exit */
 101 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 102 static int Jflag;                       /* list available time stamp types */
 103 #endif
 104 static char *zflag = NULL;              /* compress each savefile using a specified command (like gzip or bzip2) */
 105
 106 static int infodelay;
 107 static int infoprint;
 108
 109 char *program_name;
 110
 111 int32_t thiszone;               /* seconds offset from gmt to local time */
 112
 113 /* Forwards */
 114 static RETSIGTYPE cleanup(int);
 115 static RETSIGTYPE child_cleanup(int);
 116 static void usage(void) __attribute__((noreturn));
 117 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
 118
 119 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 120 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
 121 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 122 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 123 static void droproot(const char *, const char *);
 124 static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
 125      __attribute__ ((noreturn, format (printf, 2, 3)));
 126 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 127
 128 #ifdef SIGNAL_REQ_INFO
 129 RETSIGTYPE requestinfo(int);
 130 #endif
 131
 132 #if defined(USE_WIN32_MM_TIMER)
 133   #include <MMsystem.h>
 134   static UINT timer_id;
 135   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
 136 #elif defined(HAVE_ALARM)
 137   static void verbose_stats_dump(int sig);
 138 #endif
 139
 140 static void info(int);
 141 static u_int packets_captured;
 142
 143 struct printer {
 144         if_printer f;
 145         int type;
 146 };
 147
 148
 149 struct ndo_printer {
 150         if_ndo_printer f;
 151         int type;
 152 };
 153
 154
 155 static struct printer printers[] = {
 156         { arcnet_if_print,      DLT_ARCNET },
 157 #ifdef DLT_ARCNET_LINUX
 158         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 159 #endif
 160         { token_if_print,       DLT_IEEE802 },
 161 #ifdef DLT_LANE8023
 162         { lane_if_print,        DLT_LANE8023 },
 163 #endif
 164 #ifdef DLT_CIP
 165         { cip_if_print,         DLT_CIP },
 166 #endif
 167 #ifdef DLT_ATM_CLIP
 168         { cip_if_print,         DLT_ATM_CLIP },
 169 #endif
 170         { sl_if_print,          DLT_SLIP },
 171 #ifdef DLT_SLIP_BSDOS
 172         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 173 #endif
 174         { ppp_if_print,         DLT_PPP },
 175 #ifdef DLT_PPP_WITHDIRECTION
 176         { ppp_if_print,         DLT_PPP_WITHDIRECTION },
 177 #endif
 178 #ifdef DLT_PPP_BSDOS
 179         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 180 #endif
 181         { fddi_if_print,        DLT_FDDI },
 182         { null_if_print,        DLT_NULL },
 183 #ifdef DLT_LOOP
 184         { null_if_print,        DLT_LOOP },
 185 #endif
 186         { raw_if_print,         DLT_RAW },
 187         { atm_if_print,         DLT_ATM_RFC1483 },
 188 #ifdef DLT_C_HDLC
 189         { chdlc_if_print,       DLT_C_HDLC },
 190 #endif
 191 #ifdef DLT_HDLC
 192         { chdlc_if_print,       DLT_HDLC },
 193 #endif
 194 #ifdef DLT_PPP_SERIAL
 195         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 196 #endif
 197 #ifdef DLT_PPP_ETHER
 198         { pppoe_if_print,       DLT_PPP_ETHER },
 199 #endif
 200 #ifdef DLT_LINUX_SLL
 201         { sll_if_print,         DLT_LINUX_SLL },
 202 #endif
 203 #ifdef DLT_IEEE802_11
 204         { ieee802_11_if_print,  DLT_IEEE802_11},
 205 #endif
 206 #ifdef DLT_LTALK
 207         { ltalk_if_print,       DLT_LTALK },
 208 #endif
 209 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
 210         { pflog_if_print,       DLT_PFLOG },
 211 #endif
 212 #ifdef DLT_FR
 213         { fr_if_print,          DLT_FR },
 214 #endif
 215 #ifdef DLT_FRELAY
 216         { fr_if_print,          DLT_FRELAY },
 217 #endif
 218 #ifdef DLT_SUNATM
 219         { sunatm_if_print,      DLT_SUNATM },
 220 #endif
 221 #ifdef DLT_IP_OVER_FC
 222         { ipfc_if_print,        DLT_IP_OVER_FC },
 223 #endif
 224 #ifdef DLT_PRISM_HEADER
 225         { prism_if_print,       DLT_PRISM_HEADER },
 226 #endif
 227 #ifdef DLT_IEEE802_11_RADIO
 228         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 229 #endif
 230 #ifdef DLT_ENC
 231         { enc_if_print,         DLT_ENC },
 232 #endif
 233 #ifdef DLT_SYMANTEC_FIREWALL
 234         { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
 235 #endif
 236 #ifdef DLT_APPLE_IP_OVER_IEEE1394
 237         { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
 238 #endif
 239 #ifdef DLT_IEEE802_11_RADIO_AVS
 240         { ieee802_11_radio_avs_if_print,        DLT_IEEE802_11_RADIO_AVS },
 241 #endif
 242 #ifdef DLT_JUNIPER_ATM1
 243         { juniper_atm1_print,   DLT_JUNIPER_ATM1 },
 244 #endif
 245 #ifdef DLT_JUNIPER_ATM2
 246         { juniper_atm2_print,   DLT_JUNIPER_ATM2 },
 247 #endif
 248 #ifdef DLT_JUNIPER_MFR
 249         { juniper_mfr_print,    DLT_JUNIPER_MFR },
 250 #endif
 251 #ifdef DLT_JUNIPER_MLFR
 252         { juniper_mlfr_print,   DLT_JUNIPER_MLFR },
 253 #endif
 254 #ifdef DLT_JUNIPER_MLPPP
 255         { juniper_mlppp_print,  DLT_JUNIPER_MLPPP },
 256 #endif
 257 #ifdef DLT_JUNIPER_PPPOE
 258         { juniper_pppoe_print,  DLT_JUNIPER_PPPOE },
 259 #endif
 260 #ifdef DLT_JUNIPER_PPPOE_ATM
 261         { juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
 262 #endif
 263 #ifdef DLT_JUNIPER_GGSN
 264         { juniper_ggsn_print,   DLT_JUNIPER_GGSN },
 265 #endif
 266 #ifdef DLT_JUNIPER_ES
 267         { juniper_es_print,     DLT_JUNIPER_ES },
 268 #endif
 269 #ifdef DLT_JUNIPER_MONITOR
 270         { juniper_monitor_print, DLT_JUNIPER_MONITOR },
 271 #endif
 272 #ifdef DLT_JUNIPER_SERVICES
 273         { juniper_services_print, DLT_JUNIPER_SERVICES },
 274 #endif
 275 #ifdef DLT_JUNIPER_ETHER
 276         { juniper_ether_print,  DLT_JUNIPER_ETHER },
 277 #endif
 278 #ifdef DLT_JUNIPER_PPP
 279         { juniper_ppp_print,    DLT_JUNIPER_PPP },
 280 #endif
 281 #ifdef DLT_JUNIPER_FRELAY
 282         { juniper_frelay_print, DLT_JUNIPER_FRELAY },
 283 #endif
 284 #ifdef DLT_JUNIPER_CHDLC
 285         { juniper_chdlc_print,  DLT_JUNIPER_CHDLC },
 286 #endif
 287 #ifdef DLT_MFR
 288         { mfr_if_print,         DLT_MFR },
 289 #endif
 290 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
 291         { bt_if_print,          DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
 292 #endif
 293 #ifdef HAVE_PCAP_USB_H
 294 #ifdef DLT_USB_LINUX
 295         { usb_linux_48_byte_print, DLT_USB_LINUX},
 296 #endif /* DLT_USB_LINUX */
 297 #ifdef DLT_USB_LINUX_MMAPPED
 298         { usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
 299 #endif /* DLT_USB_LINUX_MMAPPED */
 300 #endif /* HAVE_PCAP_USB_H */
 301 #ifdef DLT_IPV4
 302         { raw_if_print,         DLT_IPV4 },
 303 #endif
 304 #ifdef DLT_IPV6
 305         { raw_if_print,         DLT_IPV6 },
 306 #endif
 307         { NULL,                 0 },
 308 };
 309
 310 static struct ndo_printer ndo_printers[] = {
 311         { ether_if_print,       DLT_EN10MB },
 312 #ifdef DLT_IPNET
 313         { ipnet_if_print,       DLT_IPNET },
 314 #endif
 315 #ifdef DLT_IEEE802_15_4
 316         { ieee802_15_4_if_print, DLT_IEEE802_15_4 },
 317 #endif
 318 #ifdef DLT_IEEE802_15_4_NOFCS
 319         { ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
 320 #endif
 321 #ifdef DLT_PPI
 322         { ppi_if_print,         DLT_PPI },
 323 #endif
 324 #ifdef DLT_NETANALYZER
 325         { netanalyzer_if_print, DLT_NETANALYZER },
 326 #endif
 327 #ifdef DLT_NETANALYZER_TRANSPARENT
 328         { netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
 329 #endif
 330         { NULL,                 0 },
 331 };
 332
 333 if_printer
 334 lookup_printer(int type)
 335 {
 336         struct printer *p;
 337
 338         for (p = printers; p->f; ++p)
 339                 if (type == p->type)
 340                         return p->f;
 341
 342         return NULL;
 343         /* NOTREACHED */
 344 }
 345
 346 if_ndo_printer
 347 lookup_ndo_printer(int type)
 348 {
 349         struct ndo_printer *p;
 350
 351         for (p = ndo_printers; p->f; ++p)
 352                 if (type == p->type)
 353                         return p->f;
 354
 355         return NULL;
 356         /* NOTREACHED */
 357 }
 358
 359 static pcap_t *pd;
 360
 361 static int supports_monitor_mode;
 362
 363 extern int optind;
 364 extern int opterr;
 365 extern char *optarg;
 366
 367 struct print_info {
 368         netdissect_options *ndo;
 369         union {
 370                 if_printer     printer;
 371                 if_ndo_printer ndo_printer;
 372         } p;
 373         int ndo_type;
 374 };
 375
 376 struct dump_info {
 377         char    *WFileName;
 378         char    *CurrentFileName;
 379         pcap_t  *pd;
 380         pcap_dumper_t *p;
 381 };
 382
 383 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 384 static void
 385 show_tstamp_types_and_exit(const char *device, pcap_t *pd)
 386 {
 387         int n_tstamp_types;
 388         int *tstamp_types = 0;
 389         const char *tstamp_type_name;
 390         int i;
 391
 392         n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
 393         if (n_tstamp_types < 0)
 394                 error("%s", pcap_geterr(pd));
 395
 396         if (n_tstamp_types == 0) {
 397                 fprintf(stderr, "Time stamp type cannot be set for %s\n",
 398                     device);
 399                 exit(0);
 400         }
 401         fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
 402             device);
 403         for (i = 0; i < n_tstamp_types; i++) {
 404                 tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
 405                 if (tstamp_type_name != NULL) {
 406                         (void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
 407                             pcap_tstamp_type_val_to_description(tstamp_types[i]));
 408                 } else {
 409                         (void) fprintf(stderr, "  %d\n", tstamp_types[i]);
 410                 }
 411         }
 412         pcap_free_tstamp_types(tstamp_types);
 413         exit(0);
 414 }
 415 #endif
 416
 417 static void
 418 show_dlts_and_exit(const char *device, pcap_t *pd)
 419 {
 420         int n_dlts;
 421         int *dlts = 0;
 422         const char *dlt_name;
 423
 424         n_dlts = pcap_list_datalinks(pd, &dlts);
 425         if (n_dlts < 0)
 426                 error("%s", pcap_geterr(pd));
 427         else if (n_dlts == 0 || !dlts)
 428                 error("No data link types.");
 429
 430         /*
 431          * If the interface is known to support monitor mode, indicate
 432          * whether these are the data link types available when not in
 433          * monitor mode, if -I wasn't specified, or when in monitor mode,
 434          * when -I was specified (the link-layer types available in
 435          * monitor mode might be different from the ones available when
 436          * not in monitor mode).
 437          */
 438         if (supports_monitor_mode)
 439                 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
 440                     device,
 441                     Iflag ? "when in monitor mode" : "when not in monitor mode");
 442         else
 443                 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
 444                     device);
 445
 446         while (--n_dlts >= 0) {
 447                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 448                 if (dlt_name != NULL) {
 449                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 450                             pcap_datalink_val_to_description(dlts[n_dlts]));
 451
 452                         /*
 453                          * OK, does tcpdump handle that type?
 454                          */
 455                         if (lookup_printer(dlts[n_dlts]) == NULL
 456                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
 457                                 (void) fprintf(stderr, " (printing not supported)");
 458                         fprintf(stderr, "\n");
 459                 } else {
 460                         (void) fprintf(stderr, "  DLT %d (printing not supported)\n",
 461                             dlts[n_dlts]);
 462                 }
 463         }
 464         pcap_free_datalinks(dlts);
 465         exit(0);
 466 }
 467
 468 /*
 469  * Set up flags that might or might not be supported depending on the
 470  * version of libpcap we're using.
 471  */
 472 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 473 #define B_FLAG          "B:"
 474 #define B_FLAG_USAGE    " [ -B size ]"
 475 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 476 #define B_FLAG
 477 #define B_FLAG_USAGE
 478 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 479
 480 #ifdef HAVE_PCAP_CREATE
 481 #define I_FLAG          "I"
 482 #else /* HAVE_PCAP_CREATE */
 483 #define I_FLAG
 484 #endif /* HAVE_PCAP_CREATE */
 485
 486 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 487 #define j_FLAG          "j:"
 488 #define j_FLAG_USAGE    " [ -j tstamptype ]"
 489 #define J_FLAG          "J"
 490 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 491 #define j_FLAG
 492 #define j_FLAG_USAGE
 493 #define J_FLAG
 494 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 495
 496 #ifdef HAVE_PCAP_FINDALLDEVS
 497 #ifndef HAVE_PCAP_IF_T
 498 #undef HAVE_PCAP_FINDALLDEVS
 499 #endif
 500 #endif
 501
 502 #ifdef HAVE_PCAP_FINDALLDEVS
 503 #define D_FLAG  "D"
 504 #else
 505 #define D_FLAG
 506 #endif
 507
 508 #ifdef HAVE_PCAP_DUMP_FLUSH
 509 #define U_FLAG  "U"
 510 #else
 511 #define U_FLAG
 512 #endif
 513
 514 #ifndef WIN32
 515 /* Drop root privileges and chroot if necessary */
 516 static void
 517 droproot(const char *username, const char *chroot_dir)
 518 {
 519         struct passwd *pw = NULL;
 520
 521         if (chroot_dir && !username) {
 522                 fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
 523                 exit(1);
 524         }
 525
 526         pw = getpwnam(username);
 527         if (pw) {
 528                 if (chroot_dir) {
 529                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
 530                                 fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
 531                                     chroot_dir, pcap_strerror(errno));
 532                                 exit(1);
 533                         }
 534                 }
 535                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 536                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
 537                         fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
 538                             username,
 539                             (unsigned long)pw->pw_uid,
 540                             (unsigned long)pw->pw_gid,
 541                             pcap_strerror(errno));
 542                         exit(1);
 543                 }
 544         }
 545         else {
 546                 fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
 547                     username);
 548                 exit(1);
 549         }
 550 }
 551 #endif /* WIN32 */
 552
 553 static int
 554 getWflagChars(int x)
 555 {
 556         int c = 0;
 557
 558         x -= 1;
 559         while (x > 0) {
 560                 c += 1;
 561                 x /= 10;
 562         }
 563
 564         return c;
 565 }
 566
 567
 568 static void
 569 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 570 {
 571         char *filename = malloc(NAME_MAX + 1);
 572
 573         /* Process with strftime if Gflag is set. */
 574         if (Gflag != 0) {
 575           struct tm *local_tm;
 576
 577           /* Convert Gflag_time to a usable format */
 578           if ((local_tm = localtime(&Gflag_time)) == NULL) {
 579                   error("MakeTimedFilename: localtime");
 580           }
 581
 582           /* There's no good way to detect an error in strftime since a return
 583            * value of 0 isn't necessarily failure.
 584            */
 585           strftime(filename, NAME_MAX, orig_name, local_tm);
 586         } else {
 587           strncpy(filename, orig_name, NAME_MAX);
 588         }
 589
 590         if (cnt == 0 && max_chars == 0)
 591                 strncpy(buffer, filename, NAME_MAX + 1);
 592         else
 593                 if (snprintf(buffer, NAME_MAX + 1, "%s%0*d", filename, max_chars, cnt) > NAME_MAX)
 594                   /* Report an error if the filename is too large */
 595                   error("too many output files or filename is too long (> %d)", NAME_MAX);
 596         free(filename);
 597 }
 598
 599 static int tcpdump_printf(netdissect_options *ndo _U_,
 600                           const char *fmt, ...)
 601 {
 602
 603   va_list args;
 604   int ret;
 605
 606   va_start(args, fmt);
 607   ret=vfprintf(stdout, fmt, args);
 608   va_end(args);
 609
 610   return ret;
 611 }
 612
 613 int
 614 main(int argc, char **argv)
 615 {
 616         register int cnt, op, i;
 617         bpf_u_int32 localnet, netmask;
 618         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 619         pcap_handler callback;
 620         int type;
 621         struct bpf_program fcode;
 622 #ifndef WIN32
 623         RETSIGTYPE (*oldhandler)(int);
 624 #endif
 625         struct print_info printinfo;
 626         struct dump_info dumpinfo;
 627         u_char *pcap_userdata;
 628         char ebuf[PCAP_ERRBUF_SIZE];
 629         char *username = NULL;
 630         char *chroot_dir = NULL;
 631 #ifdef HAVE_PCAP_FINDALLDEVS
 632         pcap_if_t *devpointer;
 633         int devnum;
 634 #endif
 635         int status;
 636 #ifdef WIN32
 637         if(wsockinit() != 0) return 1;
 638 #endif /* WIN32 */
 639
 640         jflag=-1;       /* not set */
 641         gndo->ndo_Oflag=1;
 642         gndo->ndo_Rflag=1;
 643         gndo->ndo_dlt=-1;
 644         gndo->ndo_default_print=ndo_default_print;
 645         gndo->ndo_printf=tcpdump_printf;
 646         gndo->ndo_error=ndo_error;
 647         gndo->ndo_warning=ndo_warning;
 648         gndo->ndo_snaplen = DEFAULT_SNAPLEN;
 649
 650         cnt = -1;
 651         device = NULL;
 652         infile = NULL;
 653         RFileName = NULL;
 654         WFileName = NULL;
 655         if ((cp = strrchr(argv[0], '/')) != NULL)
 656                 program_name = cp + 1;
 657         else
 658                 program_name = argv[0];
 659
 660         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 661                 error("%s", ebuf);
 662
 663 #ifdef LIBSMI
 664         smiInit("tcpdump");
 665 #endif
 666
 667         while (
 668             (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)
 669                 switch (op) {
 670
 671                 case 'a':
 672                         /* compatibility for old -a */
 673                         break;
 674
 675                 case 'A':
 676                         ++Aflag;
 677                         break;
 678
 679                 case 'b':
 680                         ++bflag;
 681                         break;
 682
 683 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 684                 case 'B':
 685                         Bflag = atoi(optarg)*1024;
 686                         if (Bflag <= 0)
 687                                 error("invalid packet buffer size %s", optarg);
 688                         break;
 689 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 690
 691                 case 'c':
 692                         cnt = atoi(optarg);
 693                         if (cnt <= 0)
 694                                 error("invalid packet count %s", optarg);
 695                         break;
 696
 697                 case 'C':
 698                         Cflag = atoi(optarg) * 1000000;
 699                         if (Cflag < 0)
 700                                 error("invalid file size %s", optarg);
 701                         break;
 702
 703                 case 'd':
 704                         ++dflag;
 705                         break;
 706
 707 #ifdef HAVE_PCAP_FINDALLDEVS
 708                 case 'D':
 709                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 710                                 error("%s", ebuf);
 711                         else {
 712                                 for (i = 0; devpointer != 0; i++) {
 713                                         printf("%d.%s", i+1, devpointer->name);
 714                                         if (devpointer->description != NULL)
 715                                                 printf(" (%s)", devpointer->description);
 716                                         printf("\n");
 717                                         devpointer = devpointer->next;
 718                                 }
 719                         }
 720                         return 0;
 721 #endif /* HAVE_PCAP_FINDALLDEVS */
 722
 723                 case 'L':
 724                         Lflag++;
 725                         break;
 726
 727                 case 'e':
 728                         ++eflag;
 729                         break;
 730
 731                 case 'E':
 732 #ifndef HAVE_LIBCRYPTO
 733                         warning("crypto code not compiled in");
 734 #endif
 735                         gndo->ndo_espsecret = optarg;
 736                         break;
 737
 738                 case 'f':
 739                         ++fflag;
 740                         break;
 741
 742                 case 'F':
 743                         infile = optarg;
 744                         break;
 745
 746                 case 'G':
 747                         Gflag = atoi(optarg);
 748                         if (Gflag < 0)
 749                                 error("invalid number of seconds %s", optarg);
 750
 751                         /* We will create one file initially. */
 752                         Gflag_count = 0;
 753
 754                         /* Grab the current time for rotation use. */
 755                         if ((Gflag_time = time(NULL)) == (time_t)-1) {
 756                                 error("main: can't get current time: %s",
 757                                     pcap_strerror(errno));
 758                         }
 759                         break;
 760
 761                 case 'h':
 762                         usage();
 763                         break;
 764
 765                 case 'H':
 766                         ++Hflag;
 767                         break;
 768
 769                 case 'i':
 770                         if (optarg[0] == '0' && optarg[1] == 0)
 771                                 error("Invalid adapter index");
 772
 773 #ifdef HAVE_PCAP_FINDALLDEVS
 774                         /*
 775                          * If the argument is a number, treat it as
 776                          * an index into the list of adapters, as
 777                          * printed by "tcpdump -D".
 778                          *
 779                          * This should be OK on UNIX systems, as interfaces
 780                          * shouldn't have names that begin with digits.
 781                          * It can be useful on Windows, where more than
 782                          * one interface can have the same name.
 783                          */
 784                         if ((devnum = atoi(optarg)) != 0) {
 785                                 if (devnum < 0)
 786                                         error("Invalid adapter index");
 787
 788                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 789                                         error("%s", ebuf);
 790                                 else {
 791                                         /*
 792                                          * Look for the devnum-th entry
 793                                          * in the list of devices
 794                                          * (1-based).
 795                                          */
 796                                         for (i = 0;
 797                                             i < devnum-1 && devpointer != NULL;
 798                                             i++, devpointer = devpointer->next)
 799                                                 ;
 800                                         if (devpointer == NULL)
 801                                                 error("Invalid adapter index");
 802                                 }
 803                                 device = devpointer->name;
 804                                 break;
 805                         }
 806 #endif /* HAVE_PCAP_FINDALLDEVS */
 807                         device = optarg;
 808                         break;
 809
 810 #ifdef HAVE_PCAP_CREATE
 811                 case 'I':
 812                         ++Iflag;
 813                         break;
 814 #endif /* HAVE_PCAP_CREATE */
 815
 816 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 817                 case 'j':
 818                         jflag = pcap_tstamp_type_name_to_val(optarg);
 819                         if (jflag < 0)
 820                                 error("invalid time stamp type %s", optarg);
 821                         break;
 822
 823                 case 'J':
 824                         Jflag++;
 825                         break;
 826 #endif
 827
 828                 case 'l':
 829 #ifdef WIN32
 830                         /*
 831                          * _IOLBF is the same as _IOFBF in Microsoft's C
 832                          * libraries; the only alternative they offer
 833                          * is _IONBF.
 834                          *
 835                          * XXX - this should really be checking for MSVC++,
 836                          * not WIN32, if, for example, MinGW has its own
 837                          * C library that is more UNIX-compatible.
 838                          */
 839                         setvbuf(stdout, NULL, _IONBF, 0);
 840 #else /* WIN32 */
 841 #ifdef HAVE_SETLINEBUF
 842                         setlinebuf(stdout);
 843 #else
 844                         setvbuf(stdout, NULL, _IOLBF, 0);
 845 #endif
 846 #endif /* WIN32 */
 847                         break;
 848
 849                 case 'K':
 850                         ++Kflag;
 851                         break;
 852
 853                 case 'm':
 854 #ifdef LIBSMI
 855                         if (smiLoadModule(optarg) == 0) {
 856                                 error("could not load MIB module %s", optarg);
 857                         }
 858                         sflag = 1;
 859 #else
 860                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 861                                       program_name, optarg);
 862                         (void)fprintf(stderr, "(no libsmi support)\n");
 863 #endif
 864                         break;
 865
 866                 case 'M':
 867                         /* TCP-MD5 shared secret */
 868 #ifndef HAVE_LIBCRYPTO
 869                         warning("crypto code not compiled in");
 870 #endif
 871                         sigsecret = optarg;
 872                         break;
 873
 874                 case 'n':
 875                         ++nflag;
 876                         break;
 877
 878                 case 'N':
 879                         ++Nflag;
 880                         break;
 881
 882                 case 'O':
 883                         Oflag = 0;
 884                         break;
 885
 886                 case 'p':
 887                         ++pflag;
 888                         break;
 889
 890                 case 'q':
 891                         ++qflag;
 892                         ++suppress_default_print;
 893                         break;
 894
 895                 case 'r':
 896                         RFileName = optarg;
 897                         break;
 898
 899                 case 'R':
 900                         Rflag = 0;
 901                         break;
 902
 903                 case 's': {
 904                         char *end;
 905
 906                         snaplen = strtol(optarg, &end, 0);
 907                         if (optarg == end || *end != '\0'
 908                             || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
 909                                 error("invalid snaplen %s", optarg);
 910                         else if (snaplen == 0)
 911                                 snaplen = MAXIMUM_SNAPLEN;
 912                         break;
 913                 }
 914
 915                 case 'S':
 916                         ++Sflag;
 917                         break;
 918
 919                 case 't':
 920                         ++tflag;
 921                         break;
 922
 923                 case 'T':
 924                         if (strcasecmp(optarg, "vat") == 0)
 925                                 packettype = PT_VAT;
 926                         else if (strcasecmp(optarg, "wb") == 0)
 927                                 packettype = PT_WB;
 928                         else if (strcasecmp(optarg, "rpc") == 0)
 929                                 packettype = PT_RPC;
 930                         else if (strcasecmp(optarg, "rtp") == 0)
 931                                 packettype = PT_RTP;
 932                         else if (strcasecmp(optarg, "rtcp") == 0)
 933                                 packettype = PT_RTCP;
 934                         else if (strcasecmp(optarg, "snmp") == 0)
 935                                 packettype = PT_SNMP;
 936                         else if (strcasecmp(optarg, "cnfp") == 0)
 937                                 packettype = PT_CNFP;
 938                         else if (strcasecmp(optarg, "tftp") == 0)
 939                                 packettype = PT_TFTP;
 940                         else if (strcasecmp(optarg, "aodv") == 0)
 941                                 packettype = PT_AODV;
 942                         else if (strcasecmp(optarg, "carp") == 0)
 943                                 packettype = PT_CARP;
 944                         else
 945                                 error("unknown packet type `%s'", optarg);
 946                         break;
 947
 948                 case 'u':
 949                         ++uflag;
 950                         break;
 951
 952 #ifdef HAVE_PCAP_DUMP_FLUSH
 953                 case 'U':
 954                         ++Uflag;
 955                         break;
 956 #endif
 957
 958                 case 'v':
 959                         ++vflag;
 960                         break;
 961
 962                 case 'w':
 963                         WFileName = optarg;
 964                         break;
 965
 966                 case 'W':
 967                         Wflag = atoi(optarg);
 968                         if (Wflag < 0)
 969                                 error("invalid number of output files %s", optarg);
 970                         WflagChars = getWflagChars(Wflag);
 971                         break;
 972
 973                 case 'x':
 974                         ++xflag;
 975                         ++suppress_default_print;
 976                         break;
 977
 978                 case 'X':
 979                         ++Xflag;
 980                         ++suppress_default_print;
 981                         break;
 982
 983                 case 'y':
 984                         gndo->ndo_dltname = optarg;
 985                         gndo->ndo_dlt =
 986                           pcap_datalink_name_to_val(gndo->ndo_dltname);
 987                         if (gndo->ndo_dlt < 0)
 988                                 error("invalid data link type %s", gndo->ndo_dltname);
 989                         break;
 990
 991 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 992                 case 'Y':
 993                         {
 994                         /* Undocumented flag */
 995 #ifdef HAVE_PCAP_DEBUG
 996                         extern int pcap_debug;
 997                         pcap_debug = 1;
 998 #else
 999                         extern int yydebug;
1000                         yydebug = 1;
1001 #endif
1002                         }
1003                         break;
1004 #endif
1005                 case 'z':
1006                         if (optarg) {
1007                                 zflag = strdup(optarg);
1008                         } else {
1009                                 usage();
1010                                 /* NOTREACHED */
1011                         }
1012                         break;
1013
1014                 case 'Z':
1015                         if (optarg) {
1016                                 username = strdup(optarg);
1017                         }
1018                         else {
1019                                 usage();
1020                                 /* NOTREACHED */
1021                         }
1022                         break;
1023
1024                 default:
1025                         usage();
1026                         /* NOTREACHED */
1027                 }
1028
1029         switch (tflag) {
1030
1031         case 0: /* Default */
1032         case 4: /* Default + Date*/
1033                 thiszone = gmt2local(0);
1034                 break;
1035
1036         case 1: /* No time stamp */
1037         case 2: /* Unix timeval style */
1038         case 3: /* Microseconds since previous packet */
1039         case 5: /* Microseconds since first packet */
1040                 break;
1041
1042         default: /* Not supported */
1043                 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1044                 break;
1045         }
1046
1047 #ifdef WITH_CHROOT
1048         /* if run as root, prepare for chrooting */
1049         if (getuid() == 0 || geteuid() == 0) {
1050                 /* future extensibility for cmd-line arguments */
1051                 if (!chroot_dir)
1052                         chroot_dir = WITH_CHROOT;
1053         }
1054 #endif
1055
1056 #ifdef WITH_USER
1057         /* if run as root, prepare for dropping root privileges */
1058         if (getuid() == 0 || geteuid() == 0) {
1059                 /* Run with '-Z root' to restore old behaviour */
1060                 if (!username)
1061                         username = WITH_USER;
1062         }
1063 #endif
1064
1065         if (RFileName != NULL) {
1066                 int dlt;
1067                 const char *dlt_name;
1068
1069 #ifndef WIN32
1070                 /*
1071                  * We don't need network access, so relinquish any set-UID
1072                  * or set-GID privileges we have (if any).
1073                  *
1074                  * We do *not* want set-UID privileges when opening a
1075                  * trace file, as that might let the user read other
1076                  * people's trace files (especially if we're set-UID
1077                  * root).
1078                  */
1079                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1080                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1081 #endif /* WIN32 */
1082                 pd = pcap_open_offline(RFileName, ebuf);
1083                 if (pd == NULL)
1084                         error("%s", ebuf);
1085                 dlt = pcap_datalink(pd);
1086                 dlt_name = pcap_datalink_val_to_name(dlt);
1087                 if (dlt_name == NULL) {
1088                         fprintf(stderr, "reading from file %s, link-type %u\n",
1089                             RFileName, dlt);
1090                 } else {
1091                         fprintf(stderr,
1092                             "reading from file %s, link-type %s (%s)\n",
1093                             RFileName, dlt_name,
1094                             pcap_datalink_val_to_description(dlt));
1095                 }
1096                 localnet = 0;
1097                 netmask = 0;
1098                 if (fflag != 0)
1099                         error("-f and -r options are incompatible");
1100         } else {
1101                 if (device == NULL) {
1102                         device = pcap_lookupdev(ebuf);
1103                         if (device == NULL)
1104                                 error("%s", ebuf);
1105                 }
1106 #ifdef WIN32
1107                 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
1108                 {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
1109                         fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1110                 }
1111                 else
1112                 {
1113                         fprintf(stderr, "%s: listening on %s\n", program_name, device);
1114                 }
1115
1116                 fflush(stderr);
1117 #endif /* WIN32 */
1118 #ifdef HAVE_PCAP_CREATE
1119                 pd = pcap_create(device, ebuf);
1120                 if (pd == NULL)
1121                         error("%s", ebuf);
1122 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1123                 if (Jflag)
1124                         show_tstamp_types_and_exit(device, pd);
1125 #endif
1126                 /*
1127                  * Is this an interface that supports monitor mode?
1128                  */
1129                 if (pcap_can_set_rfmon(pd) == 1)
1130                         supports_monitor_mode = 1;
1131                 else
1132                         supports_monitor_mode = 0;
1133                 status = pcap_set_snaplen(pd, snaplen);
1134                 if (status != 0)
1135                         error("%s: Can't set snapshot length: %s",
1136                             device, pcap_statustostr(status));
1137                 status = pcap_set_promisc(pd, !pflag);
1138                 if (status != 0)
1139                         error("%s: Can't set promiscuous mode: %s",
1140                             device, pcap_statustostr(status));
1141                 if (Iflag) {
1142                         status = pcap_set_rfmon(pd, 1);
1143                         if (status != 0)
1144                                 error("%s: Can't set monitor mode: %s",
1145                                     device, pcap_statustostr(status));
1146                 }
1147                 status = pcap_set_timeout(pd, 1000);
1148                 if (status != 0)
1149                         error("%s: pcap_set_timeout failed: %s",
1150                             device, pcap_statustostr(status));
1151                 if (Bflag != 0) {
1152                         status = pcap_set_buffer_size(pd, Bflag);
1153                         if (status != 0)
1154                                 error("%s: Can't set buffer size: %s",
1155                                     device, pcap_statustostr(status));
1156                 }
1157 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1158                 if (jflag != -1) {
1159                         status = pcap_set_tstamp_type(pd, jflag);
1160                         if (status < 0)
1161                                 error("%s: Can't set time stamp type: %s",
1162                                     device, pcap_statustostr(status));
1163                 }
1164 #endif
1165                 status = pcap_activate(pd);
1166                 if (status < 0) {
1167                         /*
1168                          * pcap_activate() failed.
1169                          */
1170                         cp = pcap_geterr(pd);
1171                         if (status == PCAP_ERROR)
1172                                 error("%s", cp);
1173                         else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1174                                   status == PCAP_ERROR_PERM_DENIED) &&
1175                                  *cp != '\0')
1176                                 error("%s: %s\n(%s)", device,
1177                                     pcap_statustostr(status), cp);
1178                         else
1179                                 error("%s: %s", device,
1180                                     pcap_statustostr(status));
1181                 } else if (status > 0) {
1182                         /*
1183                          * pcap_activate() succeeded, but it's warning us
1184                          * of a problem it had.
1185                          */
1186                         cp = pcap_geterr(pd);
1187                         if (status == PCAP_WARNING)
1188                                 warning("%s", cp);
1189                         else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1190                                  *cp != '\0')
1191                                 warning("%s: %s\n(%s)", device,
1192                                     pcap_statustostr(status), cp);
1193                         else
1194                                 warning("%s: %s", device,
1195                                     pcap_statustostr(status));
1196                 }
1197 #else
1198                 *ebuf = '\0';
1199                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1200                 if (pd == NULL)
1201                         error("%s", ebuf);
1202                 else if (*ebuf)
1203                         warning("%s", ebuf);
1204 #endif /* HAVE_PCAP_CREATE */
1205                 /*
1206                  * Let user own process after socket has been opened.
1207                  */
1208 #ifndef WIN32
1209                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1210                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1211 #endif /* WIN32 */
1212 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1213                 if(Bflag != 0)
1214                         if(pcap_setbuff(pd, Bflag)==-1){
1215                                 error("%s", pcap_geterr(pd));
1216                         }
1217 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1218                 if (Lflag)
1219                         show_dlts_and_exit(device, pd);
1220                 if (gndo->ndo_dlt >= 0) {
1221 #ifdef HAVE_PCAP_SET_DATALINK
1222                         if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1223                                 error("%s", pcap_geterr(pd));
1224 #else
1225                         /*
1226                          * We don't actually support changing the
1227                          * data link type, so we only let them
1228                          * set it to what it already is.
1229                          */
1230                         if (gndo->ndo_dlt != pcap_datalink(pd)) {
1231                                 error("%s is not one of the DLTs supported by this device\n",
1232                                       gndo->ndo_dltname);
1233                         }
1234 #endif
1235                         (void)fprintf(stderr, "%s: data link type %s\n",
1236                                       program_name, gndo->ndo_dltname);
1237                         (void)fflush(stderr);
1238                 }
1239                 i = pcap_snapshot(pd);
1240                 if (snaplen < i) {
1241                         warning("snaplen raised from %d to %d", snaplen, i);
1242                         snaplen = i;
1243                 }
1244                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1245                         localnet = 0;
1246                         netmask = 0;
1247                         warning("%s", ebuf);
1248                 }
1249         }
1250         if (infile)
1251                 cmdbuf = read_infile(infile);
1252         else
1253                 cmdbuf = copy_argv(&argv[optind]);
1254
1255         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1256                 error("%s", pcap_geterr(pd));
1257         free(cmdbuf);
1258         if (dflag) {
1259                 bpf_dump(&fcode, dflag);
1260                 pcap_close(pd);
1261                 exit(0);
1262         }
1263         init_addrtoname(localnet, netmask);
1264         init_checksum();
1265
1266 #ifndef WIN32
1267         (void)setsignal(SIGPIPE, cleanup);
1268         (void)setsignal(SIGTERM, cleanup);
1269         (void)setsignal(SIGINT, cleanup);
1270 #endif /* WIN32 */
1271 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1272         (void)setsignal(SIGCHLD, child_cleanup);
1273 #endif
1274         /* Cooperate with nohup(1) */
1275 #ifndef WIN32
1276         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1277                 (void)setsignal(SIGHUP, oldhandler);
1278 #endif /* WIN32 */
1279
1280 #ifndef WIN32
1281         /*
1282          * If a user name was specified with "-Z", attempt to switch to
1283          * that user's UID.  This would probably be used with sudo,
1284          * to allow tcpdump to be run in a special restricted
1285          * account (if you just want to allow users to open capture
1286          * devices, and can't just give users that permission,
1287          * you'd make tcpdump set-UID or set-GID).
1288          *
1289          * Tcpdump doesn't necessarily write only to one savefile;
1290          * the general only way to allow a -Z instance to write to
1291          * savefiles as the user under whose UID it's run, rather
1292          * than as the user specified with -Z, would thus be to switch
1293          * to the original user ID before opening a capture file and
1294          * then switch back to the -Z user ID after opening the savefile.
1295          * Switching to the -Z user ID only after opening the first
1296          * savefile doesn't handle the general case.
1297          */
1298         if (getuid() == 0 || geteuid() == 0) {
1299                 if (username || chroot_dir)
1300                         droproot(username, chroot_dir);
1301         }
1302 #endif /* WIN32 */
1303
1304         if (pcap_setfilter(pd, &fcode) < 0)
1305                 error("%s", pcap_geterr(pd));
1306         if (WFileName) {
1307                 pcap_dumper_t *p;
1308                 /* Do not exceed the default NAME_MAX for files. */
1309                 dumpinfo.CurrentFileName = (char *)malloc(NAME_MAX + 1);
1310
1311                 if (dumpinfo.CurrentFileName == NULL)
1312                         error("malloc of dumpinfo.CurrentFileName");
1313
1314                 /* We do not need numbering for dumpfiles if Cflag isn't set. */
1315                 if (Cflag != 0)
1316                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1317                 else
1318                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1319
1320                 p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1321                 if (p == NULL)
1322                         error("%s", pcap_geterr(pd));
1323                 if (Cflag != 0 || Gflag != 0) {
1324                         callback = dump_packet_and_trunc;
1325                         dumpinfo.WFileName = WFileName;
1326                         dumpinfo.pd = pd;
1327                         dumpinfo.p = p;
1328                         pcap_userdata = (u_char *)&dumpinfo;
1329                 } else {
1330                         callback = dump_packet;
1331                         pcap_userdata = (u_char *)p;
1332                 }
1333 #ifdef HAVE_PCAP_DUMP_FLUSH
1334                 if (Uflag)
1335                         pcap_dump_flush(p);
1336 #endif
1337         } else {
1338                 type = pcap_datalink(pd);
1339                 printinfo.ndo_type = 1;
1340                 printinfo.ndo = gndo;
1341                 printinfo.p.ndo_printer = lookup_ndo_printer(type);
1342                 if (printinfo.p.ndo_printer == NULL) {
1343                         printinfo.p.printer = lookup_printer(type);
1344                         printinfo.ndo_type = 0;
1345                         if (printinfo.p.printer == NULL) {
1346                                 gndo->ndo_dltname = pcap_datalink_val_to_name(type);
1347                                 if (gndo->ndo_dltname != NULL)
1348                                         error("packet printing is not supported for link type %s: use -w",
1349                                               gndo->ndo_dltname);
1350                                 else
1351                                         error("packet printing is not supported for link type %d: use -w", type);
1352                         }
1353                 }
1354                 callback = print_packet;
1355                 pcap_userdata = (u_char *)&printinfo;
1356         }
1357
1358 #ifdef SIGNAL_REQ_INFO
1359         /*
1360          * We can't get statistics when reading from a file rather
1361          * than capturing from a device.
1362          */
1363         if (RFileName == NULL)
1364                 (void)setsignal(SIGNAL_REQ_INFO, requestinfo);
1365 #endif
1366
1367         if (vflag > 0 && WFileName) {
1368                 /*
1369                  * When capturing to a file, "-v" means tcpdump should,
1370                  * every 10 secodns, "v"erbosely report the number of
1371                  * packets captured.
1372                  */
1373 #ifdef USE_WIN32_MM_TIMER
1374                 /* call verbose_stats_dump() each 1000 +/-100msec */
1375                 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1376                 setvbuf(stderr, NULL, _IONBF, 0);
1377 #elif defined(HAVE_ALARM)
1378                 (void)setsignal(SIGALRM, verbose_stats_dump);
1379                 alarm(1);
1380 #endif
1381         }
1382
1383 #ifndef WIN32
1384         if (RFileName == NULL) {
1385                 int dlt;
1386                 const char *dlt_name;
1387
1388                 if (!vflag && !WFileName) {
1389                         (void)fprintf(stderr,
1390                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1391                             program_name);
1392                 } else
1393                         (void)fprintf(stderr, "%s: ", program_name);
1394                 dlt = pcap_datalink(pd);
1395                 dlt_name = pcap_datalink_val_to_name(dlt);
1396                 if (dlt_name == NULL) {
1397                         (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1398                             device, dlt, snaplen);
1399                 } else {
1400                         (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1401                             device, dlt_name,
1402                             pcap_datalink_val_to_description(dlt), snaplen);
1403                 }
1404                 (void)fflush(stderr);
1405         }
1406 #endif /* WIN32 */
1407         status = pcap_loop(pd, cnt, callback, pcap_userdata);
1408         if (WFileName == NULL) {
1409                 /*
1410                  * We're printing packets.  Flush the printed output,
1411                  * so it doesn't get intermingled with error output.
1412                  */
1413                 if (status == -2) {
1414                         /*
1415                          * We got interrupted, so perhaps we didn't
1416                          * manage to finish a line we were printing.
1417                          * Print an extra newline, just in case.
1418                          */
1419                         putchar('\n');
1420                 }
1421                 (void)fflush(stdout);
1422         }
1423         if (status == -1) {
1424                 /*
1425                  * Error.  Report it.
1426                  */
1427                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
1428                     program_name, pcap_geterr(pd));
1429         }
1430         if (RFileName == NULL) {
1431                 /*
1432                  * We're doing a live capture.  Report the capture
1433                  * statistics.
1434                  */
1435                 info(1);
1436         }
1437         pcap_close(pd);
1438         exit(status == -1 ? 1 : 0);
1439 }
1440
1441 /* make a clean exit on interrupts */
1442 static RETSIGTYPE
1443 cleanup(int signo _U_)
1444 {
1445 #ifdef USE_WIN32_MM_TIMER
1446         if (timer_id)
1447                 timeKillEvent(timer_id);
1448         timer_id = 0;
1449 #elif defined(HAVE_ALARM)
1450         alarm(0);
1451 #endif
1452
1453 #ifdef HAVE_PCAP_BREAKLOOP
1454         /*
1455          * We have "pcap_breakloop()"; use it, so that we do as little
1456          * as possible in the signal handler (it's probably not safe
1457          * to do anything with standard I/O streams in a signal handler -
1458          * the ANSI C standard doesn't say it is).
1459          */
1460         pcap_breakloop(pd);
1461 #else
1462         /*
1463          * We don't have "pcap_breakloop()"; this isn't safe, but
1464          * it's the best we can do.  Print the summary if we're
1465          * not reading from a savefile - i.e., if we're doing a
1466          * live capture - and exit.
1467          */
1468         if (pd != NULL && pcap_file(pd) == NULL) {
1469                 /*
1470                  * We got interrupted, so perhaps we didn't
1471                  * manage to finish a line we were printing.
1472                  * Print an extra newline, just in case.
1473                  */
1474                 putchar('\n');
1475                 (void)fflush(stdout);
1476                 info(1);
1477         }
1478         exit(0);
1479 #endif
1480 }
1481
1482 /*
1483   On windows, we do not use a fork, so we do not care less about
1484   waiting a child processes to die
1485  */
1486 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1487 static RETSIGTYPE
1488 child_cleanup(int signo _U_)
1489 {
1490   wait(NULL);
1491 }
1492 #endif /* HAVE_FORK && HAVE_VFORK */
1493
1494 static void
1495 info(register int verbose)
1496 {
1497         struct pcap_stat stat;
1498
1499         /*
1500          * Older versions of libpcap didn't set ps_ifdrop on some
1501          * platforms; initialize it to 0 to handle that.
1502          */
1503         stat.ps_ifdrop = 0;
1504         if (pcap_stats(pd, &stat) < 0) {
1505                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1506                 infoprint = 0;
1507                 return;
1508         }
1509
1510         if (!verbose)
1511                 fprintf(stderr, "%s: ", program_name);
1512
1513         (void)fprintf(stderr, "%u packet%s captured", packets_captured,
1514             PLURAL_SUFFIX(packets_captured));
1515         if (!verbose)
1516                 fputs(", ", stderr);
1517         else
1518                 putc('\n', stderr);
1519         (void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
1520             PLURAL_SUFFIX(stat.ps_recv));
1521         if (!verbose)
1522                 fputs(", ", stderr);
1523         else
1524                 putc('\n', stderr);
1525         (void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
1526             PLURAL_SUFFIX(stat.ps_drop));
1527         if (stat.ps_ifdrop != 0) {
1528                 if (!verbose)
1529                         fputs(", ", stderr);
1530                 else
1531                         putc('\n', stderr);
1532                 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
1533                     stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
1534         } else
1535                 putc('\n', stderr);
1536         infoprint = 0;
1537 }
1538
1539 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1540 static void
1541 compress_savefile(const char *filename)
1542 {
1543 # ifdef HAVE_FORK
1544         if (fork())
1545 # else
1546         if (vfork())
1547 # endif
1548                 return;
1549         /*
1550          * Set to lowest priority so that this doesn't disturb the capture
1551          */
1552 #ifdef NZERO
1553         setpriority(PRIO_PROCESS, 0, NZERO - 1);
1554 #else
1555         setpriority(PRIO_PROCESS, 0, 19);
1556 #endif
1557         if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
1558                 fprintf(stderr,
1559                         "compress_savefile:execlp(%s, %s): %s\n",
1560                         zflag,
1561                         filename,
1562                         strerror(errno));
1563 # ifdef HAVE_FORK
1564         exit(1);
1565 # else
1566         _exit(1);
1567 # endif
1568 }
1569 #else  /* HAVE_FORK && HAVE_VFORK */
1570 static void
1571 compress_savefile(const char *filename)
1572 {
1573         fprintf(stderr,
1574                 "compress_savefile failed. Functionality not implemented under your system\n");
1575 }
1576 #endif /* HAVE_FORK && HAVE_VFORK */
1577
1578 static void
1579 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1580 {
1581         struct dump_info *dump_info;
1582
1583         ++packets_captured;
1584
1585         ++infodelay;
1586
1587         dump_info = (struct dump_info *)user;
1588
1589         /*
1590          * XXX - this won't force the file to rotate on the specified time
1591          * boundary, but it will rotate on the first packet received after the
1592          * specified Gflag number of seconds. Note: if a Gflag time boundary
1593          * and a Cflag size boundary coincide, the time rotation will occur
1594          * first thereby cancelling the Cflag boundary (since the file should
1595          * be 0).
1596          */
1597         if (Gflag != 0) {
1598                 /* Check if it is time to rotate */
1599                 time_t t;
1600
1601                 /* Get the current time */
1602                 if ((t = time(NULL)) == (time_t)-1) {
1603                         error("dump_and_trunc_packet: can't get current_time: %s",
1604                             pcap_strerror(errno));
1605                 }
1606
1607
1608                 /* If the time is greater than the specified window, rotate */
1609                 if (t - Gflag_time >= Gflag) {
1610                         /* Update the Gflag_time */
1611                         Gflag_time = t;
1612                         /* Update Gflag_count */
1613                         Gflag_count++;
1614                         /*
1615                          * Close the current file and open a new one.
1616                          */
1617                         pcap_dump_close(dump_info->p);
1618
1619                         /*
1620                          * Compress the file we just closed, if the user asked for it
1621                          */
1622                         if (zflag != NULL)
1623                                 compress_savefile(dump_info->CurrentFileName);
1624
1625                         /*
1626                          * Check to see if we've exceeded the Wflag (when
1627                          * not using Cflag).
1628                          */
1629                         if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
1630                                 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
1631                                     Wflag);
1632                                 exit(0);
1633                                 /* NOTREACHED */
1634                         }
1635                         if (dump_info->CurrentFileName != NULL)
1636                                 free(dump_info->CurrentFileName);
1637                         /* Allocate space for max filename + \0. */
1638                         dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1639                         if (dump_info->CurrentFileName == NULL)
1640                                 error("dump_packet_and_trunc: malloc");
1641                         /*
1642                          * This is always the first file in the Cflag
1643                          * rotation: e.g. 0
1644                          * We also don't need numbering if Cflag is not set.
1645                          */
1646                         if (Cflag != 0)
1647                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
1648                                     WflagChars);
1649                         else
1650                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
1651
1652                         dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1653                         if (dump_info->p == NULL)
1654                                 error("%s", pcap_geterr(pd));
1655                 }
1656         }
1657
1658         /*
1659          * XXX - this won't prevent capture files from getting
1660          * larger than Cflag - the last packet written to the
1661          * file could put it over Cflag.
1662          */
1663         if (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) {
1664                 /*
1665                  * Close the current file and open a new one.
1666                  */
1667                 pcap_dump_close(dump_info->p);
1668
1669                 /*
1670                  * Compress the file we just closed, if the user asked for it
1671                  */
1672                 if (zflag != NULL)
1673                         compress_savefile(dump_info->CurrentFileName);
1674
1675                 Cflag_count++;
1676                 if (Wflag > 0) {
1677                         if (Cflag_count >= Wflag)
1678                                 Cflag_count = 0;
1679                 }
1680                 if (dump_info->CurrentFileName != NULL)
1681                         free(dump_info->CurrentFileName);
1682                 dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1683                 if (dump_info->CurrentFileName == NULL)
1684                         error("dump_packet_and_trunc: malloc");
1685                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
1686                 dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1687                 if (dump_info->p == NULL)
1688                         error("%s", pcap_geterr(pd));
1689         }
1690
1691         pcap_dump((u_char *)dump_info->p, h, sp);
1692 #ifdef HAVE_PCAP_DUMP_FLUSH
1693         if (Uflag)
1694                 pcap_dump_flush(dump_info->p);
1695 #endif
1696
1697         --infodelay;
1698         if (infoprint)
1699                 info(0);
1700 }
1701
1702 static void
1703 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1704 {
1705         ++packets_captured;
1706
1707         ++infodelay;
1708
1709         pcap_dump(user, h, sp);
1710 #ifdef HAVE_PCAP_DUMP_FLUSH
1711         if (Uflag)
1712                 pcap_dump_flush((pcap_dumper_t *)user);
1713 #endif
1714
1715         --infodelay;
1716         if (infoprint)
1717                 info(0);
1718 }
1719
1720 static void
1721 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1722 {
1723         struct print_info *print_info;
1724         u_int hdrlen;
1725
1726         ++packets_captured;
1727
1728         ++infodelay;
1729         ts_print(&h->ts);
1730
1731         print_info = (struct print_info *)user;
1732
1733         /*
1734          * Some printers want to check that they're not walking off the
1735          * end of the packet.
1736          * Rather than pass it all the way down, we set this global.
1737          */
1738         snapend = sp + h->caplen;
1739
1740         if(print_info->ndo_type) {
1741                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
1742         } else {
1743                 hdrlen = (*print_info->p.printer)(h, sp);
1744         }
1745
1746         if (Xflag) {
1747                 /*
1748                  * Print the raw packet data in hex and ASCII.
1749                  */
1750                 if (Xflag > 1) {
1751                         /*
1752                          * Include the link-layer header.
1753                          */
1754                         hex_and_ascii_print("\n\t", sp, h->caplen);
1755                 } else {
1756                         /*
1757                          * Don't include the link-layer header - and if
1758                          * we have nothing past the link-layer header,
1759                          * print nothing.
1760                          */
1761                         if (h->caplen > hdrlen)
1762                                 hex_and_ascii_print("\n\t", sp + hdrlen,
1763                                     h->caplen - hdrlen);
1764                 }
1765         } else if (xflag) {
1766                 /*
1767                  * Print the raw packet data in hex.
1768                  */
1769                 if (xflag > 1) {
1770                         /*
1771                          * Include the link-layer header.
1772                          */
1773                         hex_print("\n\t", sp, h->caplen);
1774                 } else {
1775                         /*
1776                          * Don't include the link-layer header - and if
1777                          * we have nothing past the link-layer header,
1778                          * print nothing.
1779                          */
1780                         if (h->caplen > hdrlen)
1781                                 hex_print("\n\t", sp + hdrlen,
1782                                     h->caplen - hdrlen);
1783                 }
1784         } else if (Aflag) {
1785                 /*
1786                  * Print the raw packet data in ASCII.
1787                  */
1788                 if (Aflag > 1) {
1789                         /*
1790                          * Include the link-layer header.
1791                          */
1792                         ascii_print(sp, h->caplen);
1793                 } else {
1794                         /*
1795                          * Don't include the link-layer header - and if
1796                          * we have nothing past the link-layer header,
1797                          * print nothing.
1798                          */
1799                         if (h->caplen > hdrlen)
1800                                 ascii_print(sp + hdrlen, h->caplen - hdrlen);
1801                 }
1802         }
1803
1804         putchar('\n');
1805
1806         --infodelay;
1807         if (infoprint)
1808                 info(0);
1809 }
1810
1811 #ifdef WIN32
1812         /*
1813          * XXX - there should really be libpcap calls to get the version
1814          * number as a string (the string would be generated from #defines
1815          * at run time, so that it's not generated from string constants
1816          * in the library, as, on many UNIX systems, those constants would
1817          * be statically linked into the application executable image, and
1818          * would thus reflect the version of libpcap on the system on
1819          * which the application was *linked*, not the system on which it's
1820          * *running*.
1821          *
1822          * That routine should be documented, unlike the "version[]"
1823          * string, so that UNIX vendors providing their own libpcaps
1824          * don't omit it (as a couple of vendors have...).
1825          *
1826          * Packet.dll should perhaps also export a routine to return the
1827          * version number of the Packet.dll code, to supply the
1828          * "Wpcap_version" information on Windows.
1829          */
1830         char WDversion[]="current-cvs.tcpdump.org";
1831 #if !defined(HAVE_GENERATED_VERSION)
1832         char version[]="current-cvs.tcpdump.org";
1833 #endif
1834         char pcap_version[]="current-cvs.tcpdump.org";
1835         char Wpcap_version[]="3.1";
1836 #endif
1837
1838 /*
1839  * By default, print the specified data out in hex and ASCII.
1840  */
1841 static void
1842 ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
1843 {
1844         hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1845 }
1846
1847 void
1848 default_print(const u_char *bp, u_int length)
1849 {
1850         ndo_default_print(gndo, bp, length);
1851 }
1852
1853 #ifdef SIGNAL_REQ_INFO
1854 RETSIGTYPE requestinfo(int signo _U_)
1855 {
1856         if (infodelay)
1857                 ++infoprint;
1858         else
1859                 info(0);
1860 }
1861 #endif
1862
1863 /*
1864  * Called once each second in verbose mode while dumping to file
1865  */
1866 #ifdef USE_WIN32_MM_TIMER
1867 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
1868                                   DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
1869 {
1870         struct pcap_stat stat;
1871
1872         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1873                 fprintf(stderr, "Got %u\r", packets_captured);
1874 }
1875 #elif defined(HAVE_ALARM)
1876 static void verbose_stats_dump(int sig _U_)
1877 {
1878         struct pcap_stat stat;
1879
1880         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1881                 fprintf(stderr, "Got %u\r", packets_captured);
1882         alarm(1);
1883 }
1884 #endif
1885
1886 static void
1887 usage(void)
1888 {
1889         extern char version[];
1890 #ifndef HAVE_PCAP_LIB_VERSION
1891 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1892         extern char pcap_version[];
1893 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1894         static char pcap_version[] = "unknown";
1895 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1896 #endif /* HAVE_PCAP_LIB_VERSION */
1897
1898 #ifdef HAVE_PCAP_LIB_VERSION
1899 #ifdef WIN32
1900         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1901 #else /* WIN32 */
1902         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1903 #endif /* WIN32 */
1904         (void)fprintf(stderr, "%s\n",pcap_lib_version());
1905 #else /* HAVE_PCAP_LIB_VERSION */
1906 #ifdef WIN32
1907         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1908         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1909 #else /* WIN32 */
1910         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1911         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1912 #endif /* WIN32 */
1913 #endif /* HAVE_PCAP_LIB_VERSION */
1914         (void)fprintf(stderr,
1915 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
1916         (void)fprintf(stderr,
1917 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
1918         (void)fprintf(stderr,
1919 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ]\n");
1920         (void)fprintf(stderr,
1921 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ]\n");
1922         (void)fprintf(stderr,
1923 "\t\t[ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
1924         (void)fprintf(stderr,
1925 "\t\t[ -Z user ] [ expression ]\n");
1926         exit(1);
1927 }
1928
1929
1930
1931 /* VARARGS */
1932 static void
1933 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
1934 {
1935         va_list ap;
1936
1937         (void)fprintf(stderr, "%s: ", program_name);
1938         va_start(ap, fmt);
1939         (void)vfprintf(stderr, fmt, ap);
1940         va_end(ap);
1941         if (*fmt) {
1942                 fmt += strlen(fmt);
1943                 if (fmt[-1] != '\n')
1944                         (void)fputc('\n', stderr);
1945         }
1946         exit(1);
1947         /* NOTREACHED */
1948 }
1949
1950 /* VARARGS */
1951 static void
1952 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
1953 {
1954         va_list ap;
1955
1956         (void)fprintf(stderr, "%s: WARNING: ", program_name);
1957         va_start(ap, fmt);
1958         (void)vfprintf(stderr, fmt, ap);
1959         va_end(ap);
1960         if (*fmt) {
1961                 fmt += strlen(fmt);
1962                 if (fmt[-1] != '\n')
1963                         (void)fputc('\n', stderr);
1964         }
1965 }