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 #ifdef SIGINFO
  93 #define SIGNAL_REQ_INFO SIGINFO
  94 #elif SIGUSR1
  95 #define SIGNAL_REQ_INFO SIGUSR1
  96 #endif
  97
  98 netdissect_options Gndo;
  99 netdissect_options *gndo = &Gndo;
 100
 101 static int dflag;                       /* print filter code */
 102 static int Lflag;                       /* list available data link types and exit */
 103 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 104 static int Jflag;                       /* list available time stamp types */
 105 #endif
 106 static char *zflag = NULL;              /* compress each savefile using a specified command (like gzip or bzip2) */
 107
 108 static int infodelay;
 109 static int infoprint;
 110
 111 char *program_name;
 112
 113 int32_t thiszone;               /* seconds offset from gmt to local time */
 114
 115 /* Forwards */
 116 static RETSIGTYPE cleanup(int);
 117 static RETSIGTYPE child_cleanup(int);
 118 static void usage(void) __attribute__((noreturn));
 119 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
 120
 121 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 122 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
 123 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 124 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 125 static void droproot(const char *, const char *);
 126 static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
 127      __attribute__ ((noreturn, format (printf, 2, 3)));
 128 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 129
 130 #ifdef SIGNAL_REQ_INFO
 131 RETSIGTYPE requestinfo(int);
 132 #endif
 133
 134 #if defined(USE_WIN32_MM_TIMER)
 135   #include <MMsystem.h>
 136   static UINT timer_id;
 137   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
 138 #elif defined(HAVE_ALARM)
 139   static void verbose_stats_dump(int sig);
 140 #endif
 141
 142 static void info(int);
 143 static u_int packets_captured;
 144
 145 struct printer {
 146         if_printer f;
 147         int type;
 148 };
 149
 150
 151 struct ndo_printer {
 152         if_ndo_printer f;
 153         int type;
 154 };
 155
 156
 157 static struct printer printers[] = {
 158         { arcnet_if_print,      DLT_ARCNET },
 159 #ifdef DLT_ARCNET_LINUX
 160         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 161 #endif
 162         { token_if_print,       DLT_IEEE802 },
 163 #ifdef DLT_LANE8023
 164         { lane_if_print,        DLT_LANE8023 },
 165 #endif
 166 #ifdef DLT_CIP
 167         { cip_if_print,         DLT_CIP },
 168 #endif
 169 #ifdef DLT_ATM_CLIP
 170         { cip_if_print,         DLT_ATM_CLIP },
 171 #endif
 172         { sl_if_print,          DLT_SLIP },
 173 #ifdef DLT_SLIP_BSDOS
 174         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 175 #endif
 176         { ppp_if_print,         DLT_PPP },
 177 #ifdef DLT_PPP_WITHDIRECTION
 178         { ppp_if_print,         DLT_PPP_WITHDIRECTION },
 179 #endif
 180 #ifdef DLT_PPP_BSDOS
 181         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 182 #endif
 183         { fddi_if_print,        DLT_FDDI },
 184         { null_if_print,        DLT_NULL },
 185 #ifdef DLT_LOOP
 186         { null_if_print,        DLT_LOOP },
 187 #endif
 188         { raw_if_print,         DLT_RAW },
 189         { atm_if_print,         DLT_ATM_RFC1483 },
 190 #ifdef DLT_C_HDLC
 191         { chdlc_if_print,       DLT_C_HDLC },
 192 #endif
 193 #ifdef DLT_HDLC
 194         { chdlc_if_print,       DLT_HDLC },
 195 #endif
 196 #ifdef DLT_PPP_SERIAL
 197         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 198 #endif
 199 #ifdef DLT_PPP_ETHER
 200         { pppoe_if_print,       DLT_PPP_ETHER },
 201 #endif
 202 #ifdef DLT_LINUX_SLL
 203         { sll_if_print,         DLT_LINUX_SLL },
 204 #endif
 205 #ifdef DLT_IEEE802_11
 206         { ieee802_11_if_print,  DLT_IEEE802_11},
 207 #endif
 208 #ifdef DLT_LTALK
 209         { ltalk_if_print,       DLT_LTALK },
 210 #endif
 211 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
 212         { pflog_if_print,       DLT_PFLOG },
 213 #endif
 214 #ifdef DLT_FR
 215         { fr_if_print,          DLT_FR },
 216 #endif
 217 #ifdef DLT_FRELAY
 218         { fr_if_print,          DLT_FRELAY },
 219 #endif
 220 #ifdef DLT_SUNATM
 221         { sunatm_if_print,      DLT_SUNATM },
 222 #endif
 223 #ifdef DLT_IP_OVER_FC
 224         { ipfc_if_print,        DLT_IP_OVER_FC },
 225 #endif
 226 #ifdef DLT_PRISM_HEADER
 227         { prism_if_print,       DLT_PRISM_HEADER },
 228 #endif
 229 #ifdef DLT_IEEE802_11_RADIO
 230         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 231 #endif
 232 #ifdef DLT_ENC
 233         { enc_if_print,         DLT_ENC },
 234 #endif
 235 #ifdef DLT_SYMANTEC_FIREWALL
 236         { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
 237 #endif
 238 #ifdef DLT_APPLE_IP_OVER_IEEE1394
 239         { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
 240 #endif
 241 #ifdef DLT_IEEE802_11_RADIO_AVS
 242         { ieee802_11_radio_avs_if_print,        DLT_IEEE802_11_RADIO_AVS },
 243 #endif
 244 #ifdef DLT_JUNIPER_ATM1
 245         { juniper_atm1_print,   DLT_JUNIPER_ATM1 },
 246 #endif
 247 #ifdef DLT_JUNIPER_ATM2
 248         { juniper_atm2_print,   DLT_JUNIPER_ATM2 },
 249 #endif
 250 #ifdef DLT_JUNIPER_MFR
 251         { juniper_mfr_print,    DLT_JUNIPER_MFR },
 252 #endif
 253 #ifdef DLT_JUNIPER_MLFR
 254         { juniper_mlfr_print,   DLT_JUNIPER_MLFR },
 255 #endif
 256 #ifdef DLT_JUNIPER_MLPPP
 257         { juniper_mlppp_print,  DLT_JUNIPER_MLPPP },
 258 #endif
 259 #ifdef DLT_JUNIPER_PPPOE
 260         { juniper_pppoe_print,  DLT_JUNIPER_PPPOE },
 261 #endif
 262 #ifdef DLT_JUNIPER_PPPOE_ATM
 263         { juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
 264 #endif
 265 #ifdef DLT_JUNIPER_GGSN
 266         { juniper_ggsn_print,   DLT_JUNIPER_GGSN },
 267 #endif
 268 #ifdef DLT_JUNIPER_ES
 269         { juniper_es_print,     DLT_JUNIPER_ES },
 270 #endif
 271 #ifdef DLT_JUNIPER_MONITOR
 272         { juniper_monitor_print, DLT_JUNIPER_MONITOR },
 273 #endif
 274 #ifdef DLT_JUNIPER_SERVICES
 275         { juniper_services_print, DLT_JUNIPER_SERVICES },
 276 #endif
 277 #ifdef DLT_JUNIPER_ETHER
 278         { juniper_ether_print,  DLT_JUNIPER_ETHER },
 279 #endif
 280 #ifdef DLT_JUNIPER_PPP
 281         { juniper_ppp_print,    DLT_JUNIPER_PPP },
 282 #endif
 283 #ifdef DLT_JUNIPER_FRELAY
 284         { juniper_frelay_print, DLT_JUNIPER_FRELAY },
 285 #endif
 286 #ifdef DLT_JUNIPER_CHDLC
 287         { juniper_chdlc_print,  DLT_JUNIPER_CHDLC },
 288 #endif
 289 #ifdef DLT_MFR
 290         { mfr_if_print,         DLT_MFR },
 291 #endif
 292 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
 293         { bt_if_print,          DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
 294 #endif
 295 #ifdef HAVE_PCAP_USB_H
 296 #ifdef DLT_USB_LINUX
 297         { usb_linux_48_byte_print, DLT_USB_LINUX},
 298 #endif /* DLT_USB_LINUX */
 299 #ifdef DLT_USB_LINUX_MMAPPED
 300         { usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
 301 #endif /* DLT_USB_LINUX_MMAPPED */
 302 #endif /* HAVE_PCAP_USB_H */
 303 #ifdef DLT_IPV4
 304         { raw_if_print,         DLT_IPV4 },
 305 #endif
 306 #ifdef DLT_IPV6
 307         { raw_if_print,         DLT_IPV6 },
 308 #endif
 309         { NULL,                 0 },
 310 };
 311
 312 static struct ndo_printer ndo_printers[] = {
 313         { ether_if_print,       DLT_EN10MB },
 314 #ifdef DLT_IPNET
 315         { ipnet_if_print,       DLT_IPNET },
 316 #endif
 317 #ifdef DLT_IEEE802_15_4
 318         { ieee802_15_4_if_print, DLT_IEEE802_15_4 },
 319 #endif
 320 #ifdef DLT_IEEE802_15_4_NOFCS
 321         { ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
 322 #endif
 323 #ifdef DLT_PPI
 324         { ppi_if_print,         DLT_PPI },
 325 #endif
 326 #ifdef DLT_NETANALYZER
 327         { netanalyzer_if_print, DLT_NETANALYZER },
 328 #endif
 329 #ifdef DLT_NETANALYZER_TRANSPARENT
 330         { netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
 331 #endif
 332         { NULL,                 0 },
 333 };
 334
 335 if_printer
 336 lookup_printer(int type)
 337 {
 338         struct printer *p;
 339
 340         for (p = printers; p->f; ++p)
 341                 if (type == p->type)
 342                         return p->f;
 343
 344         return NULL;
 345         /* NOTREACHED */
 346 }
 347
 348 if_ndo_printer
 349 lookup_ndo_printer(int type)
 350 {
 351         struct ndo_printer *p;
 352
 353         for (p = ndo_printers; p->f; ++p)
 354                 if (type == p->type)
 355                         return p->f;
 356
 357         return NULL;
 358         /* NOTREACHED */
 359 }
 360
 361 static pcap_t *pd;
 362
 363 static int supports_monitor_mode;
 364
 365 extern int optind;
 366 extern int opterr;
 367 extern char *optarg;
 368
 369 struct print_info {
 370         netdissect_options *ndo;
 371         union {
 372                 if_printer     printer;
 373                 if_ndo_printer ndo_printer;
 374         } p;
 375         int ndo_type;
 376 };
 377
 378 struct dump_info {
 379         char    *WFileName;
 380         char    *CurrentFileName;
 381         pcap_t  *pd;
 382         pcap_dumper_t *p;
 383 };
 384
 385 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 386 static void
 387 show_tstamp_types_and_exit(const char *device, pcap_t *pd)
 388 {
 389         int n_tstamp_types;
 390         int *tstamp_types = 0;
 391         const char *tstamp_type_name;
 392         int i;
 393
 394         n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
 395         if (n_tstamp_types < 0)
 396                 error("%s", pcap_geterr(pd));
 397
 398         if (n_tstamp_types == 0) {
 399                 fprintf(stderr, "Time stamp type cannot be set for %s\n",
 400                     device);
 401                 exit(0);
 402         }
 403         fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
 404             device);
 405         for (i = 0; i < n_tstamp_types; i++) {
 406                 tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
 407                 if (tstamp_type_name != NULL) {
 408                         (void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
 409                             pcap_tstamp_type_val_to_description(tstamp_types[i]));
 410                 } else {
 411                         (void) fprintf(stderr, "  %d\n", tstamp_types[i]);
 412                 }
 413         }
 414         pcap_free_tstamp_types(tstamp_types);
 415         exit(0);
 416 }
 417 #endif
 418
 419 static void
 420 show_dlts_and_exit(const char *device, pcap_t *pd)
 421 {
 422         int n_dlts;
 423         int *dlts = 0;
 424         const char *dlt_name;
 425
 426         n_dlts = pcap_list_datalinks(pd, &dlts);
 427         if (n_dlts < 0)
 428                 error("%s", pcap_geterr(pd));
 429         else if (n_dlts == 0 || !dlts)
 430                 error("No data link types.");
 431
 432         /*
 433          * If the interface is known to support monitor mode, indicate
 434          * whether these are the data link types available when not in
 435          * monitor mode, if -I wasn't specified, or when in monitor mode,
 436          * when -I was specified (the link-layer types available in
 437          * monitor mode might be different from the ones available when
 438          * not in monitor mode).
 439          */
 440         if (supports_monitor_mode)
 441                 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
 442                     device,
 443                     Iflag ? "when in monitor mode" : "when not in monitor mode");
 444         else
 445                 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
 446                     device);
 447
 448         while (--n_dlts >= 0) {
 449                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 450                 if (dlt_name != NULL) {
 451                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 452                             pcap_datalink_val_to_description(dlts[n_dlts]));
 453
 454                         /*
 455                          * OK, does tcpdump handle that type?
 456                          */
 457                         if (lookup_printer(dlts[n_dlts]) == NULL
 458                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
 459                                 (void) fprintf(stderr, " (printing not supported)");
 460                         fprintf(stderr, "\n");
 461                 } else {
 462                         (void) fprintf(stderr, "  DLT %d (printing not supported)\n",
 463                             dlts[n_dlts]);
 464                 }
 465         }
 466         pcap_free_datalinks(dlts);
 467         exit(0);
 468 }
 469
 470 /*
 471  * Set up flags that might or might not be supported depending on the
 472  * version of libpcap we're using.
 473  */
 474 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 475 #define B_FLAG          "B:"
 476 #define B_FLAG_USAGE    " [ -B size ]"
 477 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 478 #define B_FLAG
 479 #define B_FLAG_USAGE
 480 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 481
 482 #ifdef HAVE_PCAP_CREATE
 483 #define I_FLAG          "I"
 484 #else /* HAVE_PCAP_CREATE */
 485 #define I_FLAG
 486 #endif /* HAVE_PCAP_CREATE */
 487
 488 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 489 #define j_FLAG          "j:"
 490 #define j_FLAG_USAGE    " [ -j tstamptype ]"
 491 #define J_FLAG          "J"
 492 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 493 #define j_FLAG
 494 #define j_FLAG_USAGE
 495 #define J_FLAG
 496 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 497
 498 #ifdef HAVE_PCAP_FINDALLDEVS
 499 #ifndef HAVE_PCAP_IF_T
 500 #undef HAVE_PCAP_FINDALLDEVS
 501 #endif
 502 #endif
 503
 504 #ifdef HAVE_PCAP_FINDALLDEVS
 505 #define D_FLAG  "D"
 506 #else
 507 #define D_FLAG
 508 #endif
 509
 510 #ifdef HAVE_PCAP_DUMP_FLUSH
 511 #define U_FLAG  "U"
 512 #else
 513 #define U_FLAG
 514 #endif
 515
 516 #ifndef WIN32
 517 /* Drop root privileges and chroot if necessary */
 518 static void
 519 droproot(const char *username, const char *chroot_dir)
 520 {
 521         struct passwd *pw = NULL;
 522
 523         if (chroot_dir && !username) {
 524                 fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
 525                 exit(1);
 526         }
 527
 528         pw = getpwnam(username);
 529         if (pw) {
 530                 if (chroot_dir) {
 531                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
 532                                 fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
 533                                     chroot_dir, pcap_strerror(errno));
 534                                 exit(1);
 535                         }
 536                 }
 537                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 538                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
 539                         fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
 540                             username,
 541                             (unsigned long)pw->pw_uid,
 542                             (unsigned long)pw->pw_gid,
 543                             pcap_strerror(errno));
 544                         exit(1);
 545                 }
 546         }
 547         else {
 548                 fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
 549                     username);
 550                 exit(1);
 551         }
 552 }
 553 #endif /* WIN32 */
 554
 555 static int
 556 getWflagChars(int x)
 557 {
 558         int c = 0;
 559
 560         x -= 1;
 561         while (x > 0) {
 562                 c += 1;
 563                 x /= 10;
 564         }
 565
 566         return c;
 567 }
 568
 569
 570 static void
 571 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 572 {
 573         char *filename = malloc(NAME_MAX + 1);
 574
 575         /* Process with strftime if Gflag is set. */
 576         if (Gflag != 0) {
 577           struct tm *local_tm;
 578
 579           /* Convert Gflag_time to a usable format */
 580           if ((local_tm = localtime(&Gflag_time)) == NULL) {
 581                   error("MakeTimedFilename: localtime");
 582           }
 583
 584           /* There's no good way to detect an error in strftime since a return
 585            * value of 0 isn't necessarily failure.
 586            */
 587           strftime(filename, NAME_MAX, orig_name, local_tm);
 588         } else {
 589           strncpy(filename, orig_name, NAME_MAX);
 590         }
 591
 592         if (cnt == 0 && max_chars == 0)
 593                 strncpy(buffer, filename, NAME_MAX + 1);
 594         else
 595                 if (snprintf(buffer, NAME_MAX + 1, "%s%0*d", filename, max_chars, cnt) > NAME_MAX)
 596                   /* Report an error if the filename is too large */
 597                   error("too many output files or filename is too long (> %d)", NAME_MAX);
 598         free(filename);
 599 }
 600
 601 static int tcpdump_printf(netdissect_options *ndo _U_,
 602                           const char *fmt, ...)
 603 {
 604
 605   va_list args;
 606   int ret;
 607
 608   va_start(args, fmt);
 609   ret=vfprintf(stdout, fmt, args);
 610   va_end(args);
 611
 612   return ret;
 613 }
 614
 615 int
 616 main(int argc, char **argv)
 617 {
 618         register int cnt, op, i;
 619         bpf_u_int32 localnet, netmask;
 620         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 621         pcap_handler callback;
 622         int type;
 623         struct bpf_program fcode;
 624 #ifndef WIN32
 625         RETSIGTYPE (*oldhandler)(int);
 626 #endif
 627         struct print_info printinfo;
 628         struct dump_info dumpinfo;
 629         u_char *pcap_userdata;
 630         char ebuf[PCAP_ERRBUF_SIZE];
 631         char *username = NULL;
 632         char *chroot_dir = NULL;
 633 #ifdef HAVE_PCAP_FINDALLDEVS
 634         pcap_if_t *devpointer;
 635         int devnum;
 636 #endif
 637         int status;
 638 #ifdef WIN32
 639         if(wsockinit() != 0) return 1;
 640 #endif /* WIN32 */
 641
 642         jflag=-1;       /* not set */
 643         gndo->ndo_Oflag=1;
 644         gndo->ndo_Rflag=1;
 645         gndo->ndo_dlt=-1;
 646         gndo->ndo_default_print=ndo_default_print;
 647         gndo->ndo_printf=tcpdump_printf;
 648         gndo->ndo_error=ndo_error;
 649         gndo->ndo_warning=ndo_warning;
 650         gndo->ndo_snaplen = DEFAULT_SNAPLEN;
 651
 652         cnt = -1;
 653         device = NULL;
 654         infile = NULL;
 655         RFileName = NULL;
 656         WFileName = NULL;
 657         if ((cp = strrchr(argv[0], '/')) != NULL)
 658                 program_name = cp + 1;
 659         else
 660                 program_name = argv[0];
 661
 662         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 663                 error("%s", ebuf);
 664
 665 #ifdef LIBSMI
 666         smiInit("tcpdump");
 667 #endif
 668
 669         while (
 670             (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)
 671                 switch (op) {
 672
 673                 case 'a':
 674                         /* compatibility for old -a */
 675                         break;
 676
 677                 case 'A':
 678                         ++Aflag;
 679                         break;
 680
 681                 case 'b':
 682                         ++bflag;
 683                         break;
 684
 685 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 686                 case 'B':
 687                         Bflag = atoi(optarg)*1024;
 688                         if (Bflag <= 0)
 689                                 error("invalid packet buffer size %s", optarg);
 690                         break;
 691 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 692
 693                 case 'c':
 694                         cnt = atoi(optarg);
 695                         if (cnt <= 0)
 696                                 error("invalid packet count %s", optarg);
 697                         break;
 698
 699                 case 'C':
 700                         Cflag = atoi(optarg) * 1000000;
 701                         if (Cflag < 0)
 702                                 error("invalid file size %s", optarg);
 703                         break;
 704
 705                 case 'd':
 706                         ++dflag;
 707                         break;
 708
 709 #ifdef HAVE_PCAP_FINDALLDEVS
 710                 case 'D':
 711                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 712                                 error("%s", ebuf);
 713                         else {
 714                                 for (i = 0; devpointer != 0; i++) {
 715                                         printf("%d.%s", i+1, devpointer->name);
 716                                         if (devpointer->description != NULL)
 717                                                 printf(" (%s)", devpointer->description);
 718                                         printf("\n");
 719                                         devpointer = devpointer->next;
 720                                 }
 721                         }
 722                         return 0;
 723 #endif /* HAVE_PCAP_FINDALLDEVS */
 724
 725                 case 'L':
 726                         Lflag++;
 727                         break;
 728
 729                 case 'e':
 730                         ++eflag;
 731                         break;
 732
 733                 case 'E':
 734 #ifndef HAVE_LIBCRYPTO
 735                         warning("crypto code not compiled in");
 736 #endif
 737                         gndo->ndo_espsecret = optarg;
 738                         break;
 739
 740                 case 'f':
 741                         ++fflag;
 742                         break;
 743
 744                 case 'F':
 745                         infile = optarg;
 746                         break;
 747
 748                 case 'G':
 749                         Gflag = atoi(optarg);
 750                         if (Gflag < 0)
 751                                 error("invalid number of seconds %s", optarg);
 752
 753                         /* We will create one file initially. */
 754                         Gflag_count = 0;
 755
 756                         /* Grab the current time for rotation use. */
 757                         if ((Gflag_time = time(NULL)) == (time_t)-1) {
 758                                 error("main: can't get current time: %s",
 759                                     pcap_strerror(errno));
 760                         }
 761                         break;
 762
 763                 case 'h':
 764                         usage();
 765                         break;
 766
 767                 case 'H':
 768                         ++Hflag;
 769                         break;
 770
 771                 case 'i':
 772                         if (optarg[0] == '0' && optarg[1] == 0)
 773                                 error("Invalid adapter index");
 774
 775 #ifdef HAVE_PCAP_FINDALLDEVS
 776                         /*
 777                          * If the argument is a number, treat it as
 778                          * an index into the list of adapters, as
 779                          * printed by "tcpdump -D".
 780                          *
 781                          * This should be OK on UNIX systems, as interfaces
 782                          * shouldn't have names that begin with digits.
 783                          * It can be useful on Windows, where more than
 784                          * one interface can have the same name.
 785                          */
 786                         if ((devnum = atoi(optarg)) != 0) {
 787                                 if (devnum < 0)
 788                                         error("Invalid adapter index");
 789
 790                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 791                                         error("%s", ebuf);
 792                                 else {
 793                                         /*
 794                                          * Look for the devnum-th entry
 795                                          * in the list of devices
 796                                          * (1-based).
 797                                          */
 798                                         for (i = 0;
 799                                             i < devnum-1 && devpointer != NULL;
 800                                             i++, devpointer = devpointer->next)
 801                                                 ;
 802                                         if (devpointer == NULL)
 803                                                 error("Invalid adapter index");
 804                                 }
 805                                 device = devpointer->name;
 806                                 break;
 807                         }
 808 #endif /* HAVE_PCAP_FINDALLDEVS */
 809                         device = optarg;
 810                         break;
 811
 812 #ifdef HAVE_PCAP_CREATE
 813                 case 'I':
 814                         ++Iflag;
 815                         break;
 816 #endif /* HAVE_PCAP_CREATE */
 817
 818 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 819                 case 'j':
 820                         jflag = pcap_tstamp_type_name_to_val(optarg);
 821                         if (jflag < 0)
 822                                 error("invalid time stamp type %s", optarg);
 823                         break;
 824
 825                 case 'J':
 826                         Jflag++;
 827                         break;
 828 #endif
 829
 830                 case 'l':
 831 #ifdef WIN32
 832                         /*
 833                          * _IOLBF is the same as _IOFBF in Microsoft's C
 834                          * libraries; the only alternative they offer
 835                          * is _IONBF.
 836                          *
 837                          * XXX - this should really be checking for MSVC++,
 838                          * not WIN32, if, for example, MinGW has its own
 839                          * C library that is more UNIX-compatible.
 840                          */
 841                         setvbuf(stdout, NULL, _IONBF, 0);
 842 #else /* WIN32 */
 843 #ifdef HAVE_SETLINEBUF
 844                         setlinebuf(stdout);
 845 #else
 846                         setvbuf(stdout, NULL, _IOLBF, 0);
 847 #endif
 848 #endif /* WIN32 */
 849                         break;
 850
 851                 case 'K':
 852                         ++Kflag;
 853                         break;
 854
 855                 case 'm':
 856 #ifdef LIBSMI
 857                         if (smiLoadModule(optarg) == 0) {
 858                                 error("could not load MIB module %s", optarg);
 859                         }
 860                         sflag = 1;
 861 #else
 862                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 863                                       program_name, optarg);
 864                         (void)fprintf(stderr, "(no libsmi support)\n");
 865 #endif
 866                         break;
 867
 868                 case 'M':
 869                         /* TCP-MD5 shared secret */
 870 #ifndef HAVE_LIBCRYPTO
 871                         warning("crypto code not compiled in");
 872 #endif
 873                         sigsecret = optarg;
 874                         break;
 875
 876                 case 'n':
 877                         ++nflag;
 878                         break;
 879
 880                 case 'N':
 881                         ++Nflag;
 882                         break;
 883
 884                 case 'O':
 885                         Oflag = 0;
 886                         break;
 887
 888                 case 'p':
 889                         ++pflag;
 890                         break;
 891
 892                 case 'q':
 893                         ++qflag;
 894                         ++suppress_default_print;
 895                         break;
 896
 897                 case 'r':
 898                         RFileName = optarg;
 899                         break;
 900
 901                 case 'R':
 902                         Rflag = 0;
 903                         break;
 904
 905                 case 's': {
 906                         char *end;
 907
 908                         snaplen = strtol(optarg, &end, 0);
 909                         if (optarg == end || *end != '\0'
 910                             || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
 911                                 error("invalid snaplen %s", optarg);
 912                         else if (snaplen == 0)
 913                                 snaplen = MAXIMUM_SNAPLEN;
 914                         break;
 915                 }
 916
 917                 case 'S':
 918                         ++Sflag;
 919                         break;
 920
 921                 case 't':
 922                         ++tflag;
 923                         break;
 924
 925                 case 'T':
 926                         if (strcasecmp(optarg, "vat") == 0)
 927                                 packettype = PT_VAT;
 928                         else if (strcasecmp(optarg, "wb") == 0)
 929                                 packettype = PT_WB;
 930                         else if (strcasecmp(optarg, "rpc") == 0)
 931                                 packettype = PT_RPC;
 932                         else if (strcasecmp(optarg, "rtp") == 0)
 933                                 packettype = PT_RTP;
 934                         else if (strcasecmp(optarg, "rtcp") == 0)
 935                                 packettype = PT_RTCP;
 936                         else if (strcasecmp(optarg, "snmp") == 0)
 937                                 packettype = PT_SNMP;
 938                         else if (strcasecmp(optarg, "cnfp") == 0)
 939                                 packettype = PT_CNFP;
 940                         else if (strcasecmp(optarg, "tftp") == 0)
 941                                 packettype = PT_TFTP;
 942                         else if (strcasecmp(optarg, "aodv") == 0)
 943                                 packettype = PT_AODV;
 944                         else if (strcasecmp(optarg, "carp") == 0)
 945                                 packettype = PT_CARP;
 946                         else
 947                                 error("unknown packet type `%s'", optarg);
 948                         break;
 949
 950                 case 'u':
 951                         ++uflag;
 952                         break;
 953
 954 #ifdef HAVE_PCAP_DUMP_FLUSH
 955                 case 'U':
 956                         ++Uflag;
 957                         break;
 958 #endif
 959
 960                 case 'v':
 961                         ++vflag;
 962                         break;
 963
 964                 case 'w':
 965                         WFileName = optarg;
 966                         break;
 967
 968                 case 'W':
 969                         Wflag = atoi(optarg);
 970                         if (Wflag < 0)
 971                                 error("invalid number of output files %s", optarg);
 972                         WflagChars = getWflagChars(Wflag);
 973                         break;
 974
 975                 case 'x':
 976                         ++xflag;
 977                         ++suppress_default_print;
 978                         break;
 979
 980                 case 'X':
 981                         ++Xflag;
 982                         ++suppress_default_print;
 983                         break;
 984
 985                 case 'y':
 986                         gndo->ndo_dltname = optarg;
 987                         gndo->ndo_dlt =
 988                           pcap_datalink_name_to_val(gndo->ndo_dltname);
 989                         if (gndo->ndo_dlt < 0)
 990                                 error("invalid data link type %s", gndo->ndo_dltname);
 991                         break;
 992
 993 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 994                 case 'Y':
 995                         {
 996                         /* Undocumented flag */
 997 #ifdef HAVE_PCAP_DEBUG
 998                         extern int pcap_debug;
 999                         pcap_debug = 1;
1000 #else
1001                         extern int yydebug;
1002                         yydebug = 1;
1003 #endif
1004                         }
1005                         break;
1006 #endif
1007                 case 'z':
1008                         if (optarg) {
1009                                 zflag = strdup(optarg);
1010                         } else {
1011                                 usage();
1012                                 /* NOTREACHED */
1013                         }
1014                         break;
1015
1016                 case 'Z':
1017                         if (optarg) {
1018                                 username = strdup(optarg);
1019                         }
1020                         else {
1021                                 usage();
1022                                 /* NOTREACHED */
1023                         }
1024                         break;
1025
1026                 default:
1027                         usage();
1028                         /* NOTREACHED */
1029                 }
1030
1031         switch (tflag) {
1032
1033         case 0: /* Default */
1034         case 4: /* Default + Date*/
1035                 thiszone = gmt2local(0);
1036                 break;
1037
1038         case 1: /* No time stamp */
1039         case 2: /* Unix timeval style */
1040         case 3: /* Microseconds since previous packet */
1041         case 5: /* Microseconds since first packet */
1042                 break;
1043
1044         default: /* Not supported */
1045                 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1046                 break;
1047         }
1048
1049 #ifdef WITH_CHROOT
1050         /* if run as root, prepare for chrooting */
1051         if (getuid() == 0 || geteuid() == 0) {
1052                 /* future extensibility for cmd-line arguments */
1053                 if (!chroot_dir)
1054                         chroot_dir = WITH_CHROOT;
1055         }
1056 #endif
1057
1058 #ifdef WITH_USER
1059         /* if run as root, prepare for dropping root privileges */
1060         if (getuid() == 0 || geteuid() == 0) {
1061                 /* Run with '-Z root' to restore old behaviour */
1062                 if (!username)
1063                         username = WITH_USER;
1064         }
1065 #endif
1066
1067         if (RFileName != NULL) {
1068                 int dlt;
1069                 const char *dlt_name;
1070
1071 #ifndef WIN32
1072                 /*
1073                  * We don't need network access, so relinquish any set-UID
1074                  * or set-GID privileges we have (if any).
1075                  *
1076                  * We do *not* want set-UID privileges when opening a
1077                  * trace file, as that might let the user read other
1078                  * people's trace files (especially if we're set-UID
1079                  * root).
1080                  */
1081                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1082                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1083 #endif /* WIN32 */
1084                 pd = pcap_open_offline(RFileName, ebuf);
1085                 if (pd == NULL)
1086                         error("%s", ebuf);
1087                 dlt = pcap_datalink(pd);
1088                 dlt_name = pcap_datalink_val_to_name(dlt);
1089                 if (dlt_name == NULL) {
1090                         fprintf(stderr, "reading from file %s, link-type %u\n",
1091                             RFileName, dlt);
1092                 } else {
1093                         fprintf(stderr,
1094                             "reading from file %s, link-type %s (%s)\n",
1095                             RFileName, dlt_name,
1096                             pcap_datalink_val_to_description(dlt));
1097                 }
1098                 localnet = 0;
1099                 netmask = 0;
1100                 if (fflag != 0)
1101                         error("-f and -r options are incompatible");
1102         } else {
1103                 if (device == NULL) {
1104                         device = pcap_lookupdev(ebuf);
1105                         if (device == NULL)
1106                                 error("%s", ebuf);
1107                 }
1108 #ifdef WIN32
1109                 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
1110                 {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
1111                         fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1112                 }
1113                 else
1114                 {
1115                         fprintf(stderr, "%s: listening on %s\n", program_name, device);
1116                 }
1117
1118                 fflush(stderr);
1119 #endif /* WIN32 */
1120 #ifdef HAVE_PCAP_CREATE
1121                 pd = pcap_create(device, ebuf);
1122                 if (pd == NULL)
1123                         error("%s", ebuf);
1124 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1125                 if (Jflag)
1126                         show_tstamp_types_and_exit(device, pd);
1127 #endif
1128                 /*
1129                  * Is this an interface that supports monitor mode?
1130                  */
1131                 if (pcap_can_set_rfmon(pd) == 1)
1132                         supports_monitor_mode = 1;
1133                 else
1134                         supports_monitor_mode = 0;
1135                 status = pcap_set_snaplen(pd, snaplen);
1136                 if (status != 0)
1137                         error("%s: Can't set snapshot length: %s",
1138                             device, pcap_statustostr(status));
1139                 status = pcap_set_promisc(pd, !pflag);
1140                 if (status != 0)
1141                         error("%s: Can't set promiscuous mode: %s",
1142                             device, pcap_statustostr(status));
1143                 if (Iflag) {
1144                         status = pcap_set_rfmon(pd, 1);
1145                         if (status != 0)
1146                                 error("%s: Can't set monitor mode: %s",
1147                                     device, pcap_statustostr(status));
1148                 }
1149                 status = pcap_set_timeout(pd, 1000);
1150                 if (status != 0)
1151                         error("%s: pcap_set_timeout failed: %s",
1152                             device, pcap_statustostr(status));
1153                 if (Bflag != 0) {
1154                         status = pcap_set_buffer_size(pd, Bflag);
1155                         if (status != 0)
1156                                 error("%s: Can't set buffer size: %s",
1157                                     device, pcap_statustostr(status));
1158                 }
1159 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1160                 if (jflag != -1) {
1161                         status = pcap_set_tstamp_type(pd, jflag);
1162                         if (status < 0)
1163                                 error("%s: Can't set time stamp type: %s",
1164                                     device, pcap_statustostr(status));
1165                 }
1166 #endif
1167                 status = pcap_activate(pd);
1168                 if (status < 0) {
1169                         /*
1170                          * pcap_activate() failed.
1171                          */
1172                         cp = pcap_geterr(pd);
1173                         if (status == PCAP_ERROR)
1174                                 error("%s", cp);
1175                         else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1176                                   status == PCAP_ERROR_PERM_DENIED) &&
1177                                  *cp != '\0')
1178                                 error("%s: %s\n(%s)", device,
1179                                     pcap_statustostr(status), cp);
1180                         else
1181                                 error("%s: %s", device,
1182                                     pcap_statustostr(status));
1183                 } else if (status > 0) {
1184                         /*
1185                          * pcap_activate() succeeded, but it's warning us
1186                          * of a problem it had.
1187                          */
1188                         cp = pcap_geterr(pd);
1189                         if (status == PCAP_WARNING)
1190                                 warning("%s", cp);
1191                         else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1192                                  *cp != '\0')
1193                                 warning("%s: %s\n(%s)", device,
1194                                     pcap_statustostr(status), cp);
1195                         else
1196                                 warning("%s: %s", device,
1197                                     pcap_statustostr(status));
1198                 }
1199 #else
1200                 *ebuf = '\0';
1201                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1202                 if (pd == NULL)
1203                         error("%s", ebuf);
1204                 else if (*ebuf)
1205                         warning("%s", ebuf);
1206 #endif /* HAVE_PCAP_CREATE */
1207                 /*
1208                  * Let user own process after socket has been opened.
1209                  */
1210 #ifndef WIN32
1211                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1212                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1213 #endif /* WIN32 */
1214 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1215                 if(Bflag != 0)
1216                         if(pcap_setbuff(pd, Bflag)==-1){
1217                                 error("%s", pcap_geterr(pd));
1218                         }
1219 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1220                 if (Lflag)
1221                         show_dlts_and_exit(device, pd);
1222                 if (gndo->ndo_dlt >= 0) {
1223 #ifdef HAVE_PCAP_SET_DATALINK
1224                         if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1225                                 error("%s", pcap_geterr(pd));
1226 #else
1227                         /*
1228                          * We don't actually support changing the
1229                          * data link type, so we only let them
1230                          * set it to what it already is.
1231                          */
1232                         if (gndo->ndo_dlt != pcap_datalink(pd)) {
1233                                 error("%s is not one of the DLTs supported by this device\n",
1234                                       gndo->ndo_dltname);
1235                         }
1236 #endif
1237                         (void)fprintf(stderr, "%s: data link type %s\n",
1238                                       program_name, gndo->ndo_dltname);
1239                         (void)fflush(stderr);
1240                 }
1241                 i = pcap_snapshot(pd);
1242                 if (snaplen < i) {
1243                         warning("snaplen raised from %d to %d", snaplen, i);
1244                         snaplen = i;
1245                 }
1246                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1247                         localnet = 0;
1248                         netmask = 0;
1249                         warning("%s", ebuf);
1250                 }
1251         }
1252         if (infile)
1253                 cmdbuf = read_infile(infile);
1254         else
1255                 cmdbuf = copy_argv(&argv[optind]);
1256
1257         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1258                 error("%s", pcap_geterr(pd));
1259         free(cmdbuf);
1260         if (dflag) {
1261                 bpf_dump(&fcode, dflag);
1262                 pcap_close(pd);
1263                 exit(0);
1264         }
1265         init_addrtoname(localnet, netmask);
1266         init_checksum();
1267
1268 #ifndef WIN32
1269         (void)setsignal(SIGPIPE, cleanup);
1270         (void)setsignal(SIGTERM, cleanup);
1271         (void)setsignal(SIGINT, cleanup);
1272 #endif /* WIN32 */
1273 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1274         (void)setsignal(SIGCHLD, child_cleanup);
1275 #endif
1276         /* Cooperate with nohup(1) */
1277 #ifndef WIN32
1278         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1279                 (void)setsignal(SIGHUP, oldhandler);
1280 #endif /* WIN32 */
1281
1282 #ifndef WIN32
1283         /*
1284          * If a user name was specified with "-Z", attempt to switch to
1285          * that user's UID.  This would probably be used with sudo,
1286          * to allow tcpdump to be run in a special restricted
1287          * account (if you just want to allow users to open capture
1288          * devices, and can't just give users that permission,
1289          * you'd make tcpdump set-UID or set-GID).
1290          *
1291          * Tcpdump doesn't necessarily write only to one savefile;
1292          * the general only way to allow a -Z instance to write to
1293          * savefiles as the user under whose UID it's run, rather
1294          * than as the user specified with -Z, would thus be to switch
1295          * to the original user ID before opening a capture file and
1296          * then switch back to the -Z user ID after opening the savefile.
1297          * Switching to the -Z user ID only after opening the first
1298          * savefile doesn't handle the general case.
1299          */
1300         if (getuid() == 0 || geteuid() == 0) {
1301                 if (username || chroot_dir)
1302                         droproot(username, chroot_dir);
1303         }
1304 #endif /* WIN32 */
1305
1306         if (pcap_setfilter(pd, &fcode) < 0)
1307                 error("%s", pcap_geterr(pd));
1308         if (WFileName) {
1309                 pcap_dumper_t *p;
1310                 /* Do not exceed the default NAME_MAX for files. */
1311                 dumpinfo.CurrentFileName = (char *)malloc(NAME_MAX + 1);
1312
1313                 if (dumpinfo.CurrentFileName == NULL)
1314                         error("malloc of dumpinfo.CurrentFileName");
1315
1316                 /* We do not need numbering for dumpfiles if Cflag isn't set. */
1317                 if (Cflag != 0)
1318                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1319                 else
1320                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1321
1322                 p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1323                 if (p == NULL)
1324                         error("%s", pcap_geterr(pd));
1325                 if (Cflag != 0 || Gflag != 0) {
1326                         callback = dump_packet_and_trunc;
1327                         dumpinfo.WFileName = WFileName;
1328                         dumpinfo.pd = pd;
1329                         dumpinfo.p = p;
1330                         pcap_userdata = (u_char *)&dumpinfo;
1331                 } else {
1332                         callback = dump_packet;
1333                         pcap_userdata = (u_char *)p;
1334                 }
1335 #ifdef HAVE_PCAP_DUMP_FLUSH
1336                 if (Uflag)
1337                         pcap_dump_flush(p);
1338 #endif
1339         } else {
1340                 type = pcap_datalink(pd);
1341                 printinfo.ndo_type = 1;
1342                 printinfo.ndo = gndo;
1343                 printinfo.p.ndo_printer = lookup_ndo_printer(type);
1344                 if (printinfo.p.ndo_printer == NULL) {
1345                         printinfo.p.printer = lookup_printer(type);
1346                         printinfo.ndo_type = 0;
1347                         if (printinfo.p.printer == NULL) {
1348                                 gndo->ndo_dltname = pcap_datalink_val_to_name(type);
1349                                 if (gndo->ndo_dltname != NULL)
1350                                         error("packet printing is not supported for link type %s: use -w",
1351                                               gndo->ndo_dltname);
1352                                 else
1353                                         error("packet printing is not supported for link type %d: use -w", type);
1354                         }
1355                 }
1356                 callback = print_packet;
1357                 pcap_userdata = (u_char *)&printinfo;
1358         }
1359
1360 #ifdef SIGNAL_REQ_INFO
1361         /*
1362          * We can't get statistics when reading from a file rather
1363          * than capturing from a device.
1364          */
1365         if (RFileName == NULL)
1366                 (void)setsignal(SIGNAL_REQ_INFO, requestinfo);
1367 #endif
1368
1369         if (vflag > 0 && WFileName) {
1370                 /*
1371                  * When capturing to a file, "-v" means tcpdump should,
1372                  * every 10 secodns, "v"erbosely report the number of
1373                  * packets captured.
1374                  */
1375 #ifdef USE_WIN32_MM_TIMER
1376                 /* call verbose_stats_dump() each 1000 +/-100msec */
1377                 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1378                 setvbuf(stderr, NULL, _IONBF, 0);
1379 #elif defined(HAVE_ALARM)
1380                 (void)setsignal(SIGALRM, verbose_stats_dump);
1381                 alarm(1);
1382 #endif
1383         }
1384
1385 #ifndef WIN32
1386         if (RFileName == NULL) {
1387                 int dlt;
1388                 const char *dlt_name;
1389
1390                 if (!vflag && !WFileName) {
1391                         (void)fprintf(stderr,
1392                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1393                             program_name);
1394                 } else
1395                         (void)fprintf(stderr, "%s: ", program_name);
1396                 dlt = pcap_datalink(pd);
1397                 dlt_name = pcap_datalink_val_to_name(dlt);
1398                 if (dlt_name == NULL) {
1399                         (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1400                             device, dlt, snaplen);
1401                 } else {
1402                         (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1403                             device, dlt_name,
1404                             pcap_datalink_val_to_description(dlt), snaplen);
1405                 }
1406                 (void)fflush(stderr);
1407         }
1408 #endif /* WIN32 */
1409         status = pcap_loop(pd, cnt, callback, pcap_userdata);
1410         if (WFileName == NULL) {
1411                 /*
1412                  * We're printing packets.  Flush the printed output,
1413                  * so it doesn't get intermingled with error output.
1414                  */
1415                 if (status == -2) {
1416                         /*
1417                          * We got interrupted, so perhaps we didn't
1418                          * manage to finish a line we were printing.
1419                          * Print an extra newline, just in case.
1420                          */
1421                         putchar('\n');
1422                 }
1423                 (void)fflush(stdout);
1424         }
1425         if (status == -1) {
1426                 /*
1427                  * Error.  Report it.
1428                  */
1429                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
1430                     program_name, pcap_geterr(pd));
1431         }
1432         if (RFileName == NULL) {
1433                 /*
1434                  * We're doing a live capture.  Report the capture
1435                  * statistics.
1436                  */
1437                 info(1);
1438         }
1439         pcap_close(pd);
1440         exit(status == -1 ? 1 : 0);
1441 }
1442
1443 /* make a clean exit on interrupts */
1444 static RETSIGTYPE
1445 cleanup(int signo _U_)
1446 {
1447 #ifdef USE_WIN32_MM_TIMER
1448         if (timer_id)
1449                 timeKillEvent(timer_id);
1450         timer_id = 0;
1451 #elif defined(HAVE_ALARM)
1452         alarm(0);
1453 #endif
1454
1455 #ifdef HAVE_PCAP_BREAKLOOP
1456         /*
1457          * We have "pcap_breakloop()"; use it, so that we do as little
1458          * as possible in the signal handler (it's probably not safe
1459          * to do anything with standard I/O streams in a signal handler -
1460          * the ANSI C standard doesn't say it is).
1461          */
1462         pcap_breakloop(pd);
1463 #else
1464         /*
1465          * We don't have "pcap_breakloop()"; this isn't safe, but
1466          * it's the best we can do.  Print the summary if we're
1467          * not reading from a savefile - i.e., if we're doing a
1468          * live capture - and exit.
1469          */
1470         if (pd != NULL && pcap_file(pd) == NULL) {
1471                 /*
1472                  * We got interrupted, so perhaps we didn't
1473                  * manage to finish a line we were printing.
1474                  * Print an extra newline, just in case.
1475                  */
1476                 putchar('\n');
1477                 (void)fflush(stdout);
1478                 info(1);
1479         }
1480         exit(0);
1481 #endif
1482 }
1483
1484 /*
1485   On windows, we do not use a fork, so we do not care less about
1486   waiting a child processes to die
1487  */
1488 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1489 static RETSIGTYPE
1490 child_cleanup(int signo _U_)
1491 {
1492   wait(NULL);
1493 }
1494 #endif /* HAVE_FORK && HAVE_VFORK */
1495
1496 static void
1497 info(register int verbose)
1498 {
1499         struct pcap_stat stat;
1500
1501         /*
1502          * Older versions of libpcap didn't set ps_ifdrop on some
1503          * platforms; initialize it to 0 to handle that.
1504          */
1505         stat.ps_ifdrop = 0;
1506         if (pcap_stats(pd, &stat) < 0) {
1507                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1508                 infoprint = 0;
1509                 return;
1510         }
1511
1512         if (!verbose)
1513                 fprintf(stderr, "%s: ", program_name);
1514
1515         (void)fprintf(stderr, "%u packet%s captured", packets_captured,
1516             PLURAL_SUFFIX(packets_captured));
1517         if (!verbose)
1518                 fputs(", ", stderr);
1519         else
1520                 putc('\n', stderr);
1521         (void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
1522             PLURAL_SUFFIX(stat.ps_recv));
1523         if (!verbose)
1524                 fputs(", ", stderr);
1525         else
1526                 putc('\n', stderr);
1527         (void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
1528             PLURAL_SUFFIX(stat.ps_drop));
1529         if (stat.ps_ifdrop != 0) {
1530                 if (!verbose)
1531                         fputs(", ", stderr);
1532                 else
1533                         putc('\n', stderr);
1534                 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
1535                     stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
1536         } else
1537                 putc('\n', stderr);
1538         infoprint = 0;
1539 }
1540
1541 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1542 static void
1543 compress_savefile(const char *filename)
1544 {
1545 # ifdef HAVE_FORK
1546         if (fork())
1547 # else
1548         if (vfork())
1549 # endif
1550                 return;
1551         /*
1552          * Set to lowest priority so that this doesn't disturb the capture
1553          */
1554 #ifdef NZERO
1555         setpriority(PRIO_PROCESS, 0, NZERO - 1);
1556 #else
1557         setpriority(PRIO_PROCESS, 0, 19);
1558 #endif
1559         if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
1560                 fprintf(stderr,
1561                         "compress_savefile:execlp(%s, %s): %s\n",
1562                         zflag,
1563                         filename,
1564                         strerror(errno));
1565 # ifdef HAVE_FORK
1566         exit(1);
1567 # else
1568         _exit(1);
1569 # endif
1570 }
1571 #else  /* HAVE_FORK && HAVE_VFORK */
1572 static void
1573 compress_savefile(const char *filename)
1574 {
1575         fprintf(stderr,
1576                 "compress_savefile failed. Functionality not implemented under your system\n");
1577 }
1578 #endif /* HAVE_FORK && HAVE_VFORK */
1579
1580 static void
1581 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1582 {
1583         struct dump_info *dump_info;
1584
1585         ++packets_captured;
1586
1587         ++infodelay;
1588
1589         dump_info = (struct dump_info *)user;
1590
1591         /*
1592          * XXX - this won't force the file to rotate on the specified time
1593          * boundary, but it will rotate on the first packet received after the
1594          * specified Gflag number of seconds. Note: if a Gflag time boundary
1595          * and a Cflag size boundary coincide, the time rotation will occur
1596          * first thereby cancelling the Cflag boundary (since the file should
1597          * be 0).
1598          */
1599         if (Gflag != 0) {
1600                 /* Check if it is time to rotate */
1601                 time_t t;
1602
1603                 /* Get the current time */
1604                 if ((t = time(NULL)) == (time_t)-1) {
1605                         error("dump_and_trunc_packet: can't get current_time: %s",
1606                             pcap_strerror(errno));
1607                 }
1608
1609
1610                 /* If the time is greater than the specified window, rotate */
1611                 if (t - Gflag_time >= Gflag) {
1612                         /* Update the Gflag_time */
1613                         Gflag_time = t;
1614                         /* Update Gflag_count */
1615                         Gflag_count++;
1616                         /*
1617                          * Close the current file and open a new one.
1618                          */
1619                         pcap_dump_close(dump_info->p);
1620
1621                         /*
1622                          * Compress the file we just closed, if the user asked for it
1623                          */
1624                         if (zflag != NULL)
1625                                 compress_savefile(dump_info->CurrentFileName);
1626
1627                         /*
1628                          * Check to see if we've exceeded the Wflag (when
1629                          * not using Cflag).
1630                          */
1631                         if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
1632                                 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
1633                                     Wflag);
1634                                 exit(0);
1635                                 /* NOTREACHED */
1636                         }
1637                         if (dump_info->CurrentFileName != NULL)
1638                                 free(dump_info->CurrentFileName);
1639                         /* Allocate space for max filename + \0. */
1640                         dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1641                         if (dump_info->CurrentFileName == NULL)
1642                                 error("dump_packet_and_trunc: malloc");
1643                         /*
1644                          * This is always the first file in the Cflag
1645                          * rotation: e.g. 0
1646                          * We also don't need numbering if Cflag is not set.
1647                          */
1648                         if (Cflag != 0)
1649                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
1650                                     WflagChars);
1651                         else
1652                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
1653
1654                         dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1655                         if (dump_info->p == NULL)
1656                                 error("%s", pcap_geterr(pd));
1657                 }
1658         }
1659
1660         /*
1661          * XXX - this won't prevent capture files from getting
1662          * larger than Cflag - the last packet written to the
1663          * file could put it over Cflag.
1664          */
1665         if (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) {
1666                 /*
1667                  * Close the current file and open a new one.
1668                  */
1669                 pcap_dump_close(dump_info->p);
1670
1671                 /*
1672                  * Compress the file we just closed, if the user asked for it
1673                  */
1674                 if (zflag != NULL)
1675                         compress_savefile(dump_info->CurrentFileName);
1676
1677                 Cflag_count++;
1678                 if (Wflag > 0) {
1679                         if (Cflag_count >= Wflag)
1680                                 Cflag_count = 0;
1681                 }
1682                 if (dump_info->CurrentFileName != NULL)
1683                         free(dump_info->CurrentFileName);
1684                 dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1685                 if (dump_info->CurrentFileName == NULL)
1686                         error("dump_packet_and_trunc: malloc");
1687                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
1688                 dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1689                 if (dump_info->p == NULL)
1690                         error("%s", pcap_geterr(pd));
1691         }
1692
1693         pcap_dump((u_char *)dump_info->p, h, sp);
1694 #ifdef HAVE_PCAP_DUMP_FLUSH
1695         if (Uflag)
1696                 pcap_dump_flush(dump_info->p);
1697 #endif
1698
1699         --infodelay;
1700         if (infoprint)
1701                 info(0);
1702 }
1703
1704 static void
1705 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1706 {
1707         ++packets_captured;
1708
1709         ++infodelay;
1710
1711         pcap_dump(user, h, sp);
1712 #ifdef HAVE_PCAP_DUMP_FLUSH
1713         if (Uflag)
1714                 pcap_dump_flush((pcap_dumper_t *)user);
1715 #endif
1716
1717         --infodelay;
1718         if (infoprint)
1719                 info(0);
1720 }
1721
1722 static void
1723 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1724 {
1725         struct print_info *print_info;
1726         u_int hdrlen;
1727
1728         ++packets_captured;
1729
1730         ++infodelay;
1731         ts_print(&h->ts);
1732
1733         print_info = (struct print_info *)user;
1734
1735         /*
1736          * Some printers want to check that they're not walking off the
1737          * end of the packet.
1738          * Rather than pass it all the way down, we set this global.
1739          */
1740         snapend = sp + h->caplen;
1741
1742         if(print_info->ndo_type) {
1743                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
1744         } else {
1745                 hdrlen = (*print_info->p.printer)(h, sp);
1746         }
1747
1748         if (Xflag) {
1749                 /*
1750                  * Print the raw packet data in hex and ASCII.
1751                  */
1752                 if (Xflag > 1) {
1753                         /*
1754                          * Include the link-layer header.
1755                          */
1756                         hex_and_ascii_print("\n\t", sp, h->caplen);
1757                 } else {
1758                         /*
1759                          * Don't include the link-layer header - and if
1760                          * we have nothing past the link-layer header,
1761                          * print nothing.
1762                          */
1763                         if (h->caplen > hdrlen)
1764                                 hex_and_ascii_print("\n\t", sp + hdrlen,
1765                                     h->caplen - hdrlen);
1766                 }
1767         } else if (xflag) {
1768                 /*
1769                  * Print the raw packet data in hex.
1770                  */
1771                 if (xflag > 1) {
1772                         /*
1773                          * Include the link-layer header.
1774                          */
1775                         hex_print("\n\t", sp, h->caplen);
1776                 } else {
1777                         /*
1778                          * Don't include the link-layer header - and if
1779                          * we have nothing past the link-layer header,
1780                          * print nothing.
1781                          */
1782                         if (h->caplen > hdrlen)
1783                                 hex_print("\n\t", sp + hdrlen,
1784                                     h->caplen - hdrlen);
1785                 }
1786         } else if (Aflag) {
1787                 /*
1788                  * Print the raw packet data in ASCII.
1789                  */
1790                 if (Aflag > 1) {
1791                         /*
1792                          * Include the link-layer header.
1793                          */
1794                         ascii_print(sp, h->caplen);
1795                 } else {
1796                         /*
1797                          * Don't include the link-layer header - and if
1798                          * we have nothing past the link-layer header,
1799                          * print nothing.
1800                          */
1801                         if (h->caplen > hdrlen)
1802                                 ascii_print(sp + hdrlen, h->caplen - hdrlen);
1803                 }
1804         }
1805
1806         putchar('\n');
1807
1808         --infodelay;
1809         if (infoprint)
1810                 info(0);
1811 }
1812
1813 #ifdef WIN32
1814         /*
1815          * XXX - there should really be libpcap calls to get the version
1816          * number as a string (the string would be generated from #defines
1817          * at run time, so that it's not generated from string constants
1818          * in the library, as, on many UNIX systems, those constants would
1819          * be statically linked into the application executable image, and
1820          * would thus reflect the version of libpcap on the system on
1821          * which the application was *linked*, not the system on which it's
1822          * *running*.
1823          *
1824          * That routine should be documented, unlike the "version[]"
1825          * string, so that UNIX vendors providing their own libpcaps
1826          * don't omit it (as a couple of vendors have...).
1827          *
1828          * Packet.dll should perhaps also export a routine to return the
1829          * version number of the Packet.dll code, to supply the
1830          * "Wpcap_version" information on Windows.
1831          */
1832         char WDversion[]="current-cvs.tcpdump.org";
1833 #if !defined(HAVE_GENERATED_VERSION)
1834         char version[]="current-cvs.tcpdump.org";
1835 #endif
1836         char pcap_version[]="current-cvs.tcpdump.org";
1837         char Wpcap_version[]="3.1";
1838 #endif
1839
1840 /*
1841  * By default, print the specified data out in hex and ASCII.
1842  */
1843 static void
1844 ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
1845 {
1846         hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1847 }
1848
1849 void
1850 default_print(const u_char *bp, u_int length)
1851 {
1852         ndo_default_print(gndo, bp, length);
1853 }
1854
1855 #ifdef SIGNAL_REQ_INFO
1856 RETSIGTYPE requestinfo(int signo _U_)
1857 {
1858         if (infodelay)
1859                 ++infoprint;
1860         else
1861                 info(0);
1862 }
1863 #endif
1864
1865 /*
1866  * Called once each second in verbose mode while dumping to file
1867  */
1868 #ifdef USE_WIN32_MM_TIMER
1869 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
1870                                   DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
1871 {
1872         struct pcap_stat stat;
1873
1874         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1875                 fprintf(stderr, "Got %u\r", packets_captured);
1876 }
1877 #elif defined(HAVE_ALARM)
1878 static void verbose_stats_dump(int sig _U_)
1879 {
1880         struct pcap_stat stat;
1881
1882         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1883                 fprintf(stderr, "Got %u\r", packets_captured);
1884         alarm(1);
1885 }
1886 #endif
1887
1888 static void
1889 usage(void)
1890 {
1891         extern char version[];
1892 #ifndef HAVE_PCAP_LIB_VERSION
1893 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1894         extern char pcap_version[];
1895 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1896         static char pcap_version[] = "unknown";
1897 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1898 #endif /* HAVE_PCAP_LIB_VERSION */
1899
1900 #ifdef HAVE_PCAP_LIB_VERSION
1901 #ifdef WIN32
1902         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1903 #else /* WIN32 */
1904         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1905 #endif /* WIN32 */
1906         (void)fprintf(stderr, "%s\n",pcap_lib_version());
1907 #else /* HAVE_PCAP_LIB_VERSION */
1908 #ifdef WIN32
1909         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1910         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1911 #else /* WIN32 */
1912         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1913         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1914 #endif /* WIN32 */
1915 #endif /* HAVE_PCAP_LIB_VERSION */
1916         (void)fprintf(stderr,
1917 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
1918         (void)fprintf(stderr,
1919 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
1920         (void)fprintf(stderr,
1921 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ]\n");
1922         (void)fprintf(stderr,
1923 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -w file ]\n");
1924         (void)fprintf(stderr,
1925 "\t\t[ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
1926         (void)fprintf(stderr,
1927 "\t\t[ -Z user ] [ expression ]\n");
1928         exit(1);
1929 }
1930
1931
1932
1933 /* VARARGS */
1934 static void
1935 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
1936 {
1937         va_list ap;
1938
1939         (void)fprintf(stderr, "%s: ", program_name);
1940         va_start(ap, fmt);
1941         (void)vfprintf(stderr, fmt, ap);
1942         va_end(ap);
1943         if (*fmt) {
1944                 fmt += strlen(fmt);
1945                 if (fmt[-1] != '\n')
1946                         (void)fputc('\n', stderr);
1947         }
1948         exit(1);
1949         /* NOTREACHED */
1950 }
1951
1952 /* VARARGS */
1953 static void
1954 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
1955 {
1956         va_list ap;
1957
1958         (void)fprintf(stderr, "%s: WARNING: ", program_name);
1959         va_start(ap, fmt);
1960         (void)vfprintf(stderr, fmt, ap);
1961         va_end(ap);
1962         if (*fmt) {
1963                 fmt += strlen(fmt);
1964                 if (fmt[-1] != '\n')
1965                         (void)fputc('\n', stderr);
1966         }
1967 }