contrib/tcpdump/tcpdump.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  *
  21  * Support for splitting captures into multiple files with a maximum
  22  * file size:
  23  *
  24  * Copyright (c) 2001
  25  *      Seth Webster <swebster@sst.ll.mit.edu>
  26  */
  27
  28 #ifndef lint
  29 static const char copyright[] _U_ =
  30     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  31 The Regents of the University of California.  All rights reserved.\n";
  32 static const char rcsid[] _U_ =
  33     "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.283 2008-09-25 21:45:50 guy Exp $ (LBL)";
  34 #endif
  35
  36 /* $FreeBSD$ */
  37
  38 /*
  39  * tcpdump - monitor tcp/ip traffic on an ethernet.
  40  *
  41  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
  42  * Mercilessly hacked and occasionally improved since then via the
  43  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
  44  */
  45
  46 #ifdef HAVE_CONFIG_H
  47 #include "config.h"
  48 #endif
  49
  50 #include <tcpdump-stdinc.h>
  51
  52 #ifdef WIN32
  53 #include "getopt.h"
  54 #include "w32_fzs.h"
  55 extern int strcasecmp (const char *__s1, const char *__s2);
  56 extern int SIZE_BUF;
  57 #define off_t long
  58 #define uint UINT
  59 #endif /* WIN32 */
  60
  61 #ifdef HAVE_SMI_H
  62 #include <smi.h>
  63 #endif
  64
  65 #include <pcap.h>
  66 #include <signal.h>
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70 #include <limits.h>
  71 #ifndef WIN32
  72 #include <sys/wait.h>
  73 #include <sys/resource.h>
  74 #include <pwd.h>
  75 #include <grp.h>
  76 #include <errno.h>
  77 #endif /* WIN32 */
  78
  79
  80 #include "netdissect.h"
  81 #include "interface.h"
  82 #include "addrtoname.h"
  83 #include "machdep.h"
  84 #include "setsignal.h"
  85 #include "gmt2local.h"
  86 #include "pcap-missing.h"
  87
  88 #ifndef NAME_MAX
  89 #define NAME_MAX 255
  90 #endif
  91
  92 netdissect_options Gndo;
  93 netdissect_options *gndo = &Gndo;
  94
  95 static int dflag;                       /* print filter code */
  96 static int Lflag;                       /* list available data link types and exit */
  97 static char *zflag = NULL;              /* compress each savefile using a specified command (like gzip or bzip2) */
  98
  99 static int infodelay;
 100 static int infoprint;
 101
 102 char *program_name;
 103
 104 int32_t thiszone;               /* seconds offset from gmt to local time */
 105
 106 /* Forwards */
 107 static RETSIGTYPE cleanup(int);
 108 static RETSIGTYPE child_cleanup(int);
 109 static void usage(void) __attribute__((noreturn));
 110 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
 111
 112 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 113 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
 114 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 115 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 116 static void droproot(const char *, const char *);
 117 static void ndo_error(netdissect_options *ndo, const char *fmt, ...);
 118 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 119
 120 #ifdef SIGINFO
 121 RETSIGTYPE requestinfo(int);
 122 #endif
 123
 124 #if defined(USE_WIN32_MM_TIMER)
 125   #include <MMsystem.h>
 126   static UINT timer_id;
 127   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
 128 #elif defined(HAVE_ALARM)
 129   static void verbose_stats_dump(int sig);
 130 #endif
 131
 132 static void info(int);
 133 static u_int packets_captured;
 134
 135 typedef u_int (*if_printer)(const struct pcap_pkthdr *, const u_char *);
 136 typedef u_int (*if_ndo_printer)(struct netdissect_options *ndo,
 137                                 const struct pcap_pkthdr *, const u_char *);
 138
 139 struct printer {
 140         if_printer f;
 141         int type;
 142 };
 143
 144
 145 struct ndo_printer {
 146         if_ndo_printer f;
 147         int type;
 148 };
 149
 150
 151 static struct printer printers[] = {
 152         { arcnet_if_print,      DLT_ARCNET },
 153 #ifdef DLT_ARCNET_LINUX
 154         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 155 #endif
 156         { ether_if_print,       DLT_EN10MB },
 157         { token_if_print,       DLT_IEEE802 },
 158 #ifdef DLT_LANE8023
 159         { lane_if_print,        DLT_LANE8023 },
 160 #endif
 161 #ifdef DLT_CIP
 162         { cip_if_print,         DLT_CIP },
 163 #endif
 164 #ifdef DLT_ATM_CLIP
 165         { cip_if_print,         DLT_ATM_CLIP },
 166 #endif
 167         { sl_if_print,          DLT_SLIP },
 168 #ifdef DLT_SLIP_BSDOS
 169         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 170 #endif
 171         { ppp_if_print,         DLT_PPP },
 172 #ifdef DLT_PPP_WITHDIRECTION
 173         { ppp_if_print,         DLT_PPP_WITHDIRECTION },
 174 #endif
 175 #ifdef DLT_PPP_BSDOS
 176         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 177 #endif
 178         { fddi_if_print,        DLT_FDDI },
 179         { null_if_print,        DLT_NULL },
 180 #ifdef DLT_LOOP
 181         { null_if_print,        DLT_LOOP },
 182 #endif
 183         { raw_if_print,         DLT_RAW },
 184         { atm_if_print,         DLT_ATM_RFC1483 },
 185 #ifdef DLT_C_HDLC
 186         { chdlc_if_print,       DLT_C_HDLC },
 187 #endif
 188 #ifdef DLT_HDLC
 189         { chdlc_if_print,       DLT_HDLC },
 190 #endif
 191 #ifdef DLT_PPP_SERIAL
 192         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 193 #endif
 194 #ifdef DLT_PPP_ETHER
 195         { pppoe_if_print,       DLT_PPP_ETHER },
 196 #endif
 197 #ifdef DLT_LINUX_SLL
 198         { sll_if_print,         DLT_LINUX_SLL },
 199 #endif
 200 #ifdef DLT_IEEE802_11
 201         { ieee802_11_if_print,  DLT_IEEE802_11},
 202 #endif
 203 #ifdef DLT_LTALK
 204         { ltalk_if_print,       DLT_LTALK },
 205 #endif
 206 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
 207         { pflog_if_print,       DLT_PFLOG },
 208 #endif
 209 #ifdef DLT_FR
 210         { fr_if_print,          DLT_FR },
 211 #endif
 212 #ifdef DLT_FRELAY
 213         { fr_if_print,          DLT_FRELAY },
 214 #endif
 215 #ifdef DLT_SUNATM
 216         { sunatm_if_print,      DLT_SUNATM },
 217 #endif
 218 #ifdef DLT_IP_OVER_FC
 219         { ipfc_if_print,        DLT_IP_OVER_FC },
 220 #endif
 221 #ifdef DLT_PRISM_HEADER
 222         { prism_if_print,       DLT_PRISM_HEADER },
 223 #endif
 224 #ifdef DLT_IEEE802_11_RADIO
 225         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 226 #endif
 227 #ifdef DLT_ENC
 228         { enc_if_print,         DLT_ENC },
 229 #endif
 230 #ifdef DLT_SYMANTEC_FIREWALL
 231         { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
 232 #endif
 233 #ifdef DLT_APPLE_IP_OVER_IEEE1394
 234         { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
 235 #endif
 236 #ifdef DLT_IEEE802_11_RADIO_AVS
 237         { ieee802_11_radio_avs_if_print,        DLT_IEEE802_11_RADIO_AVS },
 238 #endif
 239 #ifdef DLT_JUNIPER_ATM1
 240         { juniper_atm1_print,   DLT_JUNIPER_ATM1 },
 241 #endif
 242 #ifdef DLT_JUNIPER_ATM2
 243         { juniper_atm2_print,   DLT_JUNIPER_ATM2 },
 244 #endif
 245 #ifdef DLT_JUNIPER_MFR
 246         { juniper_mfr_print,    DLT_JUNIPER_MFR },
 247 #endif
 248 #ifdef DLT_JUNIPER_MLFR
 249         { juniper_mlfr_print,   DLT_JUNIPER_MLFR },
 250 #endif
 251 #ifdef DLT_JUNIPER_MLPPP
 252         { juniper_mlppp_print,  DLT_JUNIPER_MLPPP },
 253 #endif
 254 #ifdef DLT_JUNIPER_PPPOE
 255         { juniper_pppoe_print,  DLT_JUNIPER_PPPOE },
 256 #endif
 257 #ifdef DLT_JUNIPER_PPPOE_ATM
 258         { juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
 259 #endif
 260 #ifdef DLT_JUNIPER_GGSN
 261         { juniper_ggsn_print,   DLT_JUNIPER_GGSN },
 262 #endif
 263 #ifdef DLT_JUNIPER_ES
 264         { juniper_es_print,     DLT_JUNIPER_ES },
 265 #endif
 266 #ifdef DLT_JUNIPER_MONITOR
 267         { juniper_monitor_print, DLT_JUNIPER_MONITOR },
 268 #endif
 269 #ifdef DLT_JUNIPER_SERVICES
 270         { juniper_services_print, DLT_JUNIPER_SERVICES },
 271 #endif
 272 #ifdef DLT_JUNIPER_ETHER
 273         { juniper_ether_print,  DLT_JUNIPER_ETHER },
 274 #endif
 275 #ifdef DLT_JUNIPER_PPP
 276         { juniper_ppp_print,    DLT_JUNIPER_PPP },
 277 #endif
 278 #ifdef DLT_JUNIPER_FRELAY
 279         { juniper_frelay_print, DLT_JUNIPER_FRELAY },
 280 #endif
 281 #ifdef DLT_JUNIPER_CHDLC
 282         { juniper_chdlc_print,  DLT_JUNIPER_CHDLC },
 283 #endif
 284 #ifdef DLT_MFR
 285         { mfr_if_print,         DLT_MFR },
 286 #endif
 287 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
 288         { bt_if_print,          DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
 289 #endif
 290 #ifdef HAVE_PCAP_USB_H
 291 #ifdef DLT_USB_LINUX
 292         { usb_linux_48_byte_print, DLT_USB_LINUX},
 293 #endif /* DLT_USB_LINUX */
 294 #ifdef DLT_USB_LINUX_MMAPPED
 295         { usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
 296 #endif /* DLT_USB_LINUX_MMAPPED */
 297 #endif /* HAVE_PCAP_USB_H */
 298 #ifdef DLT_IPV4
 299         { raw_if_print,         DLT_IPV4 },
 300 #endif
 301 #ifdef DLT_IPV6
 302         { raw_if_print,         DLT_IPV6 },
 303 #endif
 304         { NULL,                 0 },
 305 };
 306
 307 static struct ndo_printer ndo_printers[] = {
 308 #ifdef DLT_IPNET
 309         { ipnet_if_print,       DLT_IPNET },
 310 #endif
 311         { NULL,                 0 },
 312 };
 313
 314 static if_printer
 315 lookup_printer(int type)
 316 {
 317         struct printer *p;
 318
 319         for (p = printers; p->f; ++p)
 320                 if (type == p->type)
 321                         return p->f;
 322
 323         return NULL;
 324         /* NOTREACHED */
 325 }
 326
 327 static if_ndo_printer
 328 lookup_ndo_printer(int type)
 329 {
 330         struct ndo_printer *p;
 331
 332         for (p = ndo_printers; p->f; ++p)
 333                 if (type == p->type)
 334                         return p->f;
 335
 336         return NULL;
 337         /* NOTREACHED */
 338 }
 339
 340 static pcap_t *pd;
 341
 342 static int supports_monitor_mode;
 343
 344 extern int optind;
 345 extern int opterr;
 346 extern char *optarg;
 347
 348 struct print_info {
 349         netdissect_options *ndo;
 350         union {
 351                 if_printer     printer;
 352                 if_ndo_printer ndo_printer;
 353         } p;
 354         int ndo_type;
 355 };
 356
 357 struct dump_info {
 358         char    *WFileName;
 359         char    *CurrentFileName;
 360         pcap_t  *pd;
 361         pcap_dumper_t *p;
 362 };
 363
 364 static void
 365 show_dlts_and_exit(const char *device, pcap_t *pd)
 366 {
 367         int n_dlts;
 368         int *dlts = 0;
 369         const char *dlt_name;
 370
 371         n_dlts = pcap_list_datalinks(pd, &dlts);
 372         if (n_dlts < 0)
 373                 error("%s", pcap_geterr(pd));
 374         else if (n_dlts == 0 || !dlts)
 375                 error("No data link types.");
 376
 377         /*
 378          * If the interface is known to support monitor mode, indicate
 379          * whether these are the data link types available when not in
 380          * monitor mode, if -I wasn't specified, or when in monitor mode,
 381          * when -I was specified (the link-layer types available in
 382          * monitor mode might be different from the ones available when
 383          * not in monitor mode).
 384          */
 385         if (supports_monitor_mode)
 386                 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
 387                     device,
 388                     Iflag ? "when in monitor mode" : "when not in monitor mode");
 389         else
 390                 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
 391                     device);
 392
 393         while (--n_dlts >= 0) {
 394                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 395                 if (dlt_name != NULL) {
 396                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 397                             pcap_datalink_val_to_description(dlts[n_dlts]));
 398
 399                         /*
 400                          * OK, does tcpdump handle that type?
 401                          */
 402                         if (lookup_printer(dlts[n_dlts]) == NULL
 403                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
 404                                 (void) fprintf(stderr, " (printing not supported)");
 405                         putchar('\n');
 406                 } else {
 407                         (void) fprintf(stderr, "  DLT %d (printing not supported)\n",
 408                             dlts[n_dlts]);
 409                 }
 410         }
 411         free(dlts);
 412         exit(0);
 413 }
 414
 415 /*
 416  * Set up flags that might or might not be supported depending on the
 417  * version of libpcap we're using.
 418  */
 419 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 420 #define B_FLAG          "B:"
 421 #define B_FLAG_USAGE    " [ -B size ]"
 422 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 423 #define B_FLAG
 424 #define B_FLAG_USAGE
 425 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 426
 427 #ifdef HAVE_PCAP_CREATE
 428 #define I_FLAG          "I"
 429 #else /* HAVE_PCAP_CREATE */
 430 #define I_FLAG
 431 #endif /* HAVE_PCAP_CREATE */
 432
 433 #ifdef HAVE_PCAP_FINDALLDEVS
 434 #ifndef HAVE_PCAP_IF_T
 435 #undef HAVE_PCAP_FINDALLDEVS
 436 #endif
 437 #endif
 438
 439 #ifdef HAVE_PCAP_FINDALLDEVS
 440 #define D_FLAG  "D"
 441 #else
 442 #define D_FLAG
 443 #endif
 444
 445 #ifdef HAVE_PCAP_DUMP_FLUSH
 446 #define U_FLAG  "U"
 447 #else
 448 #define U_FLAG
 449 #endif
 450
 451 #ifndef WIN32
 452 /* Drop root privileges and chroot if necessary */
 453 static void
 454 droproot(const char *username, const char *chroot_dir)
 455 {
 456         struct passwd *pw = NULL;
 457
 458         if (chroot_dir && !username) {
 459                 fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
 460                 exit(1);
 461         }
 462
 463         pw = getpwnam(username);
 464         if (pw) {
 465                 if (chroot_dir) {
 466                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
 467                                 fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
 468                                     chroot_dir, pcap_strerror(errno));
 469                                 exit(1);
 470                         }
 471                 }
 472                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 473                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
 474                         fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
 475                             username,
 476                             (unsigned long)pw->pw_uid,
 477                             (unsigned long)pw->pw_gid,
 478                             pcap_strerror(errno));
 479                         exit(1);
 480                 }
 481         }
 482         else {
 483                 fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
 484                     username);
 485                 exit(1);
 486         }
 487 }
 488 #endif /* WIN32 */
 489
 490 static int
 491 getWflagChars(int x)
 492 {
 493         int c = 0;
 494
 495         x -= 1;
 496         while (x > 0) {
 497                 c += 1;
 498                 x /= 10;
 499         }
 500
 501         return c;
 502 }
 503
 504
 505 static void
 506 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 507 {
 508         char *filename = malloc(NAME_MAX + 1);
 509
 510         /* Process with strftime if Gflag is set. */
 511         if (Gflag != 0) {
 512           struct tm *local_tm;
 513
 514           /* Convert Gflag_time to a usable format */
 515           if ((local_tm = localtime(&Gflag_time)) == NULL) {
 516                   error("MakeTimedFilename: localtime");
 517           }
 518
 519           /* There's no good way to detect an error in strftime since a return
 520            * value of 0 isn't necessarily failure.
 521            */
 522           strftime(filename, NAME_MAX, orig_name, local_tm);
 523         } else {
 524           strncpy(filename, orig_name, NAME_MAX);
 525         }
 526
 527         if (cnt == 0 && max_chars == 0)
 528                 strncpy(buffer, filename, NAME_MAX + 1);
 529         else
 530                 if (snprintf(buffer, NAME_MAX + 1, "%s%0*d", filename, max_chars, cnt) > NAME_MAX)
 531                   /* Report an error if the filename is too large */
 532                   error("too many output files or filename is too long (> %d)", NAME_MAX);
 533         free(filename);
 534 }
 535
 536 static int tcpdump_printf(netdissect_options *ndo _U_,
 537                           const char *fmt, ...)
 538 {
 539
 540   va_list args;
 541   int ret;
 542
 543   va_start(args, fmt);
 544   ret=vfprintf(stdout, fmt, args);
 545   va_end(args);
 546
 547   return ret;
 548 }
 549
 550 int
 551 main(int argc, char **argv)
 552 {
 553         register int cnt, op, i;
 554         bpf_u_int32 localnet, netmask;
 555         register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName;
 556         pcap_handler callback;
 557         int type;
 558         struct bpf_program fcode;
 559 #ifndef WIN32
 560         RETSIGTYPE (*oldhandler)(int);
 561 #endif
 562         struct print_info printinfo;
 563         struct dump_info dumpinfo;
 564         u_char *pcap_userdata;
 565         char ebuf[PCAP_ERRBUF_SIZE];
 566         char *username = NULL;
 567         char *chroot_dir = NULL;
 568 #ifdef HAVE_PCAP_FINDALLDEVS
 569         pcap_if_t *devpointer;
 570         int devnum;
 571 #endif
 572         int status;
 573 #ifdef WIN32
 574         if(wsockinit() != 0) return 1;
 575 #endif /* WIN32 */
 576
 577         gndo->ndo_Oflag=1;
 578         gndo->ndo_Rflag=1;
 579         gndo->ndo_dlt=-1;
 580         gndo->ndo_default_print=ndo_default_print;
 581         gndo->ndo_printf=tcpdump_printf;
 582         gndo->ndo_error=ndo_error;
 583         gndo->ndo_warning=ndo_warning;
 584         gndo->ndo_snaplen = DEFAULT_SNAPLEN;
 585
 586         cnt = -1;
 587         device = NULL;
 588         infile = NULL;
 589         RFileName = NULL;
 590         WFileName = NULL;
 591         if ((cp = strrchr(argv[0], '/')) != NULL)
 592                 program_name = cp + 1;
 593         else
 594                 program_name = argv[0];
 595
 596         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 597                 error("%s", ebuf);
 598
 599 #ifdef LIBSMI
 600         smiInit("tcpdump");
 601 #endif
 602
 603         opterr = 0;
 604         while (
 605             (op = getopt(argc, argv, "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:i:" I_FLAG "KlLm:M:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:Yz:Z:")) != -1)
 606                 switch (op) {
 607
 608                 case 'a':
 609                         /* compatibility for old -a */
 610                         break;
 611
 612                 case 'A':
 613                         ++Aflag;
 614                         break;
 615
 616                 case 'b':
 617                         ++bflag;
 618                         break;
 619
 620 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 621                 case 'B':
 622                         Bflag = atoi(optarg)*1024;
 623                         if (Bflag <= 0)
 624                                 error("invalid packet buffer size %s", optarg);
 625                         break;
 626 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 627
 628                 case 'c':
 629                         cnt = atoi(optarg);
 630                         if (cnt <= 0)
 631                                 error("invalid packet count %s", optarg);
 632                         break;
 633
 634                 case 'C':
 635                         Cflag = atoi(optarg) * 1000000;
 636                         if (Cflag < 0)
 637                                 error("invalid file size %s", optarg);
 638                         break;
 639
 640                 case 'd':
 641                         ++dflag;
 642                         break;
 643
 644 #ifdef HAVE_PCAP_FINDALLDEVS
 645                 case 'D':
 646                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 647                                 error("%s", ebuf);
 648                         else {
 649                                 for (i = 0; devpointer != 0; i++) {
 650                                         printf("%d.%s", i+1, devpointer->name);
 651                                         if (devpointer->description != NULL)
 652                                                 printf(" (%s)", devpointer->description);
 653                                         printf("\n");
 654                                         devpointer = devpointer->next;
 655                                 }
 656                         }
 657                         return 0;
 658 #endif /* HAVE_PCAP_FINDALLDEVS */
 659
 660                 case 'L':
 661                         Lflag++;
 662                         break;
 663
 664                 case 'e':
 665                         ++eflag;
 666                         break;
 667
 668                 case 'E':
 669 #ifndef HAVE_LIBCRYPTO
 670                         warning("crypto code not compiled in");
 671 #endif
 672                         gndo->ndo_espsecret = optarg;
 673                         break;
 674
 675                 case 'f':
 676                         ++fflag;
 677                         break;
 678
 679                 case 'F':
 680                         infile = optarg;
 681                         break;
 682
 683                 case 'G':
 684                         Gflag = atoi(optarg);
 685                         if (Gflag < 0)
 686                                 error("invalid number of seconds %s", optarg);
 687
 688                         /* We will create one file initially. */
 689                         Gflag_count = 0;
 690
 691                         /* Grab the current time for rotation use. */
 692                         if ((Gflag_time = time(NULL)) == (time_t)-1) {
 693                                 error("main: can't get current time: %s",
 694                                     pcap_strerror(errno));
 695                         }
 696                         break;
 697
 698                 case 'i':
 699                         if (optarg[0] == '0' && optarg[1] == 0)
 700                                 error("Invalid adapter index");
 701
 702 #ifdef HAVE_PCAP_FINDALLDEVS
 703                         /*
 704                          * If the argument is a number, treat it as
 705                          * an index into the list of adapters, as
 706                          * printed by "tcpdump -D".
 707                          *
 708                          * This should be OK on UNIX systems, as interfaces
 709                          * shouldn't have names that begin with digits.
 710                          * It can be useful on Windows, where more than
 711                          * one interface can have the same name.
 712                          */
 713                         if ((devnum = atoi(optarg)) != 0) {
 714                                 if (devnum < 0)
 715                                         error("Invalid adapter index");
 716
 717                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 718                                         error("%s", ebuf);
 719                                 else {
 720                                         /*
 721                                          * Look for the devnum-th entry
 722                                          * in the list of devices
 723                                          * (1-based).
 724                                          */
 725                                         for (i = 0;
 726                                             i < devnum-1 && devpointer != NULL;
 727                                             i++, devpointer = devpointer->next)
 728                                                 ;
 729                                         if (devpointer == NULL)
 730                                                 error("Invalid adapter index");
 731                                 }
 732                                 device = devpointer->name;
 733                                 break;
 734                         }
 735 #endif /* HAVE_PCAP_FINDALLDEVS */
 736                         device = optarg;
 737                         break;
 738
 739 #ifdef HAVE_PCAP_CREATE
 740                 case 'I':
 741                         ++Iflag;
 742                         break;
 743 #endif /* HAVE_PCAP_CREATE */
 744
 745                 case 'l':
 746 #ifdef WIN32
 747                         /*
 748                          * _IOLBF is the same as _IOFBF in Microsoft's C
 749                          * libraries; the only alternative they offer
 750                          * is _IONBF.
 751                          *
 752                          * XXX - this should really be checking for MSVC++,
 753                          * not WIN32, if, for example, MinGW has its own
 754                          * C library that is more UNIX-compatible.
 755                          */
 756                         setvbuf(stdout, NULL, _IONBF, 0);
 757 #else /* WIN32 */
 758 #ifdef HAVE_SETLINEBUF
 759                         setlinebuf(stdout);
 760 #else
 761                         setvbuf(stdout, NULL, _IOLBF, 0);
 762 #endif
 763 #endif /* WIN32 */
 764                         break;
 765
 766                 case 'K':
 767                         ++Kflag;
 768                         break;
 769
 770                 case 'm':
 771 #ifdef LIBSMI
 772                         if (smiLoadModule(optarg) == 0) {
 773                                 error("could not load MIB module %s", optarg);
 774                         }
 775                         sflag = 1;
 776 #else
 777                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
 778                                       program_name, optarg);
 779                         (void)fprintf(stderr, "(no libsmi support)\n");
 780 #endif
 781                         break;
 782
 783                 case 'M':
 784                         /* TCP-MD5 shared secret */
 785 #ifndef HAVE_LIBCRYPTO
 786                         warning("crypto code not compiled in");
 787 #endif
 788                         sigsecret = optarg;
 789                         break;
 790
 791                 case 'n':
 792                         ++nflag;
 793                         break;
 794
 795                 case 'N':
 796                         ++Nflag;
 797                         break;
 798
 799                 case 'O':
 800                         Oflag = 0;
 801                         break;
 802
 803                 case 'p':
 804                         ++pflag;
 805                         break;
 806
 807                 case 'q':
 808                         ++qflag;
 809                         ++suppress_default_print;
 810                         break;
 811
 812                 case 'r':
 813                         RFileName = optarg;
 814                         break;
 815
 816                 case 'R':
 817                         Rflag = 0;
 818                         break;
 819
 820                 case 's': {
 821                         char *end;
 822
 823                         snaplen = strtol(optarg, &end, 0);
 824                         if (optarg == end || *end != '\0'
 825                             || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
 826                                 error("invalid snaplen %s", optarg);
 827                         else if (snaplen == 0)
 828                                 snaplen = MAXIMUM_SNAPLEN;
 829                         break;
 830                 }
 831
 832                 case 'S':
 833                         ++Sflag;
 834                         break;
 835
 836                 case 't':
 837                         ++tflag;
 838                         break;
 839
 840                 case 'T':
 841                         if (strcasecmp(optarg, "vat") == 0)
 842                                 packettype = PT_VAT;
 843                         else if (strcasecmp(optarg, "wb") == 0)
 844                                 packettype = PT_WB;
 845                         else if (strcasecmp(optarg, "rpc") == 0)
 846                                 packettype = PT_RPC;
 847                         else if (strcasecmp(optarg, "rtp") == 0)
 848                                 packettype = PT_RTP;
 849                         else if (strcasecmp(optarg, "rtcp") == 0)
 850                                 packettype = PT_RTCP;
 851                         else if (strcasecmp(optarg, "snmp") == 0)
 852                                 packettype = PT_SNMP;
 853                         else if (strcasecmp(optarg, "cnfp") == 0)
 854                                 packettype = PT_CNFP;
 855                         else if (strcasecmp(optarg, "tftp") == 0)
 856                                 packettype = PT_TFTP;
 857                         else if (strcasecmp(optarg, "aodv") == 0)
 858                                 packettype = PT_AODV;
 859                         else
 860                                 error("unknown packet type `%s'", optarg);
 861                         break;
 862
 863                 case 'u':
 864                         ++uflag;
 865                         break;
 866
 867 #ifdef HAVE_PCAP_DUMP_FLUSH
 868                 case 'U':
 869                         ++Uflag;
 870                         break;
 871 #endif
 872
 873                 case 'v':
 874                         ++vflag;
 875                         break;
 876
 877                 case 'w':
 878                         WFileName = optarg;
 879                         break;
 880
 881                 case 'W':
 882                         Wflag = atoi(optarg);
 883                         if (Wflag < 0)
 884                                 error("invalid number of output files %s", optarg);
 885                         WflagChars = getWflagChars(Wflag);
 886                         break;
 887
 888                 case 'x':
 889                         ++xflag;
 890                         ++suppress_default_print;
 891                         break;
 892
 893                 case 'X':
 894                         ++Xflag;
 895                         ++suppress_default_print;
 896                         break;
 897
 898                 case 'y':
 899                         gndo->ndo_dltname = optarg;
 900                         gndo->ndo_dlt =
 901                           pcap_datalink_name_to_val(gndo->ndo_dltname);
 902                         if (gndo->ndo_dlt < 0)
 903                                 error("invalid data link type %s", gndo->ndo_dltname);
 904                         break;
 905
 906 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 907                 case 'Y':
 908                         {
 909                         /* Undocumented flag */
 910 #ifdef HAVE_PCAP_DEBUG
 911                         extern int pcap_debug;
 912                         pcap_debug = 1;
 913 #else
 914                         extern int yydebug;
 915                         yydebug = 1;
 916 #endif
 917                         }
 918                         break;
 919 #endif
 920                 case 'z':
 921                         if (optarg) {
 922                                 zflag = strdup(optarg);
 923                         } else {
 924                                 usage();
 925                                 /* NOTREACHED */
 926                         }
 927                         break;
 928
 929                 case 'Z':
 930                         if (optarg) {
 931                                 username = strdup(optarg);
 932                         }
 933                         else {
 934                                 usage();
 935                                 /* NOTREACHED */
 936                         }
 937                         break;
 938
 939                 default:
 940                         usage();
 941                         /* NOTREACHED */
 942                 }
 943
 944         switch (tflag) {
 945
 946         case 0: /* Default */
 947         case 4: /* Default + Date*/
 948                 thiszone = gmt2local(0);
 949                 break;
 950
 951         case 1: /* No time stamp */
 952         case 2: /* Unix timeval style */
 953         case 3: /* Microseconds since previous packet */
 954         case 5: /* Microseconds since first packet */
 955                 break;
 956
 957         default: /* Not supported */
 958                 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
 959                 break;
 960         }
 961
 962 #ifdef WITH_CHROOT
 963         /* if run as root, prepare for chrooting */
 964         if (getuid() == 0 || geteuid() == 0) {
 965                 /* future extensibility for cmd-line arguments */
 966                 if (!chroot_dir)
 967                         chroot_dir = WITH_CHROOT;
 968         }
 969 #endif
 970
 971 #ifdef WITH_USER
 972         /* if run as root, prepare for dropping root privileges */
 973         if (getuid() == 0 || geteuid() == 0) {
 974                 /* Run with '-Z root' to restore old behaviour */
 975                 if (!username)
 976                         username = WITH_USER;
 977         }
 978 #endif
 979
 980         if (RFileName != NULL) {
 981                 int dlt;
 982                 const char *dlt_name;
 983
 984 #ifndef WIN32
 985                 /*
 986                  * We don't need network access, so relinquish any set-UID
 987                  * or set-GID privileges we have (if any).
 988                  *
 989                  * We do *not* want set-UID privileges when opening a
 990                  * trace file, as that might let the user read other
 991                  * people's trace files (especially if we're set-UID
 992                  * root).
 993                  */
 994                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
 995                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
 996 #endif /* WIN32 */
 997                 pd = pcap_open_offline(RFileName, ebuf);
 998                 if (pd == NULL)
 999                         error("%s", ebuf);
1000                 dlt = pcap_datalink(pd);
1001                 dlt_name = pcap_datalink_val_to_name(dlt);
1002                 if (dlt_name == NULL) {
1003                         fprintf(stderr, "reading from file %s, link-type %u\n",
1004                             RFileName, dlt);
1005                 } else {
1006                         fprintf(stderr,
1007                             "reading from file %s, link-type %s (%s)\n",
1008                             RFileName, dlt_name,
1009                             pcap_datalink_val_to_description(dlt));
1010                 }
1011                 localnet = 0;
1012                 netmask = 0;
1013                 if (fflag != 0)
1014                         error("-f and -r options are incompatible");
1015         } else {
1016                 if (device == NULL) {
1017                         device = pcap_lookupdev(ebuf);
1018                         if (device == NULL)
1019                                 error("%s", ebuf);
1020                 }
1021 #ifdef WIN32
1022                 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
1023                 {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
1024                         fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1025                 }
1026                 else
1027                 {
1028                         fprintf(stderr, "%s: listening on %s\n", program_name, device);
1029                 }
1030
1031                 fflush(stderr);
1032 #endif /* WIN32 */
1033 #ifdef HAVE_PCAP_CREATE
1034                 pd = pcap_create(device, ebuf);
1035                 if (pd == NULL)
1036                         error("%s", ebuf);
1037                 /*
1038                  * Is this an interface that supports monitor mode?
1039                  */
1040                 if (pcap_can_set_rfmon(pd) == 1)
1041                         supports_monitor_mode = 1;
1042                 else
1043                         supports_monitor_mode = 0;
1044                 status = pcap_set_snaplen(pd, snaplen);
1045                 if (status != 0)
1046                         error("%s: pcap_set_snaplen failed: %s",
1047                             device, pcap_statustostr(status));
1048                 status = pcap_set_promisc(pd, !pflag);
1049                 if (status != 0)
1050                         error("%s: pcap_set_promisc failed: %s",
1051                             device, pcap_statustostr(status));
1052                 if (Iflag) {
1053                         status = pcap_set_rfmon(pd, 1);
1054                         if (status != 0)
1055                                 error("%s: pcap_set_rfmon failed: %s",
1056                                     device, pcap_statustostr(status));
1057                 }
1058                 status = pcap_set_timeout(pd, 1000);
1059                 if (status != 0)
1060                         error("%s: pcap_set_timeout failed: %s",
1061                             device, pcap_statustostr(status));
1062                 if (Bflag != 0) {
1063                         status = pcap_set_buffer_size(pd, Bflag);
1064                         if (status != 0)
1065                                 error("%s: pcap_set_buffer_size failed: %s",
1066                                     device, pcap_statustostr(status));
1067                 }
1068                 status = pcap_activate(pd);
1069                 if (status < 0) {
1070                         /*
1071                          * pcap_activate() failed.
1072                          */
1073                         cp = pcap_geterr(pd);
1074                         if (status == PCAP_ERROR)
1075                                 error("%s", cp);
1076                         else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1077                                   status == PCAP_ERROR_PERM_DENIED) &&
1078                                  *cp != '\0')
1079                                 error("%s: %s\n(%s)", device,
1080                                     pcap_statustostr(status), cp);
1081                         else
1082                                 error("%s: %s", device,
1083                                     pcap_statustostr(status));
1084                 } else if (status > 0) {
1085                         /*
1086                          * pcap_activate() succeeded, but it's warning us
1087                          * of a problem it had.
1088                          */
1089                         cp = pcap_geterr(pd);
1090                         if (status == PCAP_WARNING)
1091                                 warning("%s", cp);
1092                         else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1093                                  *cp != '\0')
1094                                 warning("%s: %s\n(%s)", device,
1095                                     pcap_statustostr(status), cp);
1096                         else
1097                                 warning("%s: %s", device,
1098                                     pcap_statustostr(status));
1099                 }
1100 #else
1101                 *ebuf = '\0';
1102                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1103                 if (pd == NULL)
1104                         error("%s", ebuf);
1105                 else if (*ebuf)
1106                         warning("%s", ebuf);
1107 #endif /* HAVE_PCAP_CREATE */
1108                 /*
1109                  * Let user own process after socket has been opened.
1110                  */
1111 #ifndef WIN32
1112                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1113                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1114 #endif /* WIN32 */
1115 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1116                 if(Bflag != 0)
1117                         if(pcap_setbuff(pd, Bflag)==-1){
1118                                 error("%s", pcap_geterr(pd));
1119                         }
1120 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1121                 if (Lflag)
1122                         show_dlts_and_exit(device, pd);
1123                 if (gndo->ndo_dlt >= 0) {
1124 #ifdef HAVE_PCAP_SET_DATALINK
1125                         if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1126                                 error("%s", pcap_geterr(pd));
1127 #else
1128                         /*
1129                          * We don't actually support changing the
1130                          * data link type, so we only let them
1131                          * set it to what it already is.
1132                          */
1133                         if (gndo->ndo_dlt != pcap_datalink(pd)) {
1134                                 error("%s is not one of the DLTs supported by this device\n",
1135                                       gndo->ndo_dltname);
1136                         }
1137 #endif
1138                         (void)fprintf(stderr, "%s: data link type %s\n",
1139                                       program_name, gndo->ndo_dltname);
1140                         (void)fflush(stderr);
1141                 }
1142                 i = pcap_snapshot(pd);
1143                 if (snaplen < i) {
1144                         warning("snaplen raised from %d to %d", snaplen, i);
1145                         snaplen = i;
1146                 }
1147                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1148                         localnet = 0;
1149                         netmask = 0;
1150                         warning("%s", ebuf);
1151                 }
1152         }
1153         if (infile)
1154                 cmdbuf = read_infile(infile);
1155         else
1156                 cmdbuf = copy_argv(&argv[optind]);
1157
1158         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1159                 error("%s", pcap_geterr(pd));
1160         free(cmdbuf);
1161         if (dflag) {
1162                 bpf_dump(&fcode, dflag);
1163                 pcap_close(pd);
1164                 exit(0);
1165         }
1166         init_addrtoname(localnet, netmask);
1167         init_checksum();
1168
1169 #ifndef WIN32
1170         (void)setsignal(SIGPIPE, cleanup);
1171         (void)setsignal(SIGTERM, cleanup);
1172         (void)setsignal(SIGINT, cleanup);
1173         (void)setsignal(SIGCHLD, child_cleanup);
1174 #endif /* WIN32 */
1175         /* Cooperate with nohup(1) */
1176 #ifndef WIN32
1177         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1178                 (void)setsignal(SIGHUP, oldhandler);
1179 #endif /* WIN32 */
1180
1181         if (pcap_setfilter(pd, &fcode) < 0)
1182                 error("%s", pcap_geterr(pd));
1183         if (WFileName) {
1184                 pcap_dumper_t *p;
1185                 /* Do not exceed the default NAME_MAX for files. */
1186                 dumpinfo.CurrentFileName = (char *)malloc(NAME_MAX + 1);
1187
1188                 if (dumpinfo.CurrentFileName == NULL)
1189                         error("malloc of dumpinfo.CurrentFileName");
1190
1191                 /* We do not need numbering for dumpfiles if Cflag isn't set. */
1192                 if (Cflag != 0)
1193                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1194                 else
1195                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1196
1197                 p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1198                 if (p == NULL)
1199                         error("%s", pcap_geterr(pd));
1200                 if (Cflag != 0 || Gflag != 0) {
1201                         callback = dump_packet_and_trunc;
1202                         dumpinfo.WFileName = WFileName;
1203                         dumpinfo.pd = pd;
1204                         dumpinfo.p = p;
1205                         pcap_userdata = (u_char *)&dumpinfo;
1206                 } else {
1207                         callback = dump_packet;
1208                         pcap_userdata = (u_char *)p;
1209                 }
1210         } else {
1211                 type = pcap_datalink(pd);
1212                 printinfo.ndo_type = 1;
1213                 printinfo.ndo = gndo;
1214                 printinfo.p.ndo_printer = lookup_ndo_printer(type);
1215                 if (printinfo.p.ndo_printer == NULL) {
1216                         printinfo.p.printer = lookup_printer(type);
1217                         printinfo.ndo_type = 0;
1218                         if (printinfo.p.printer == NULL) {
1219                                 gndo->ndo_dltname = pcap_datalink_val_to_name(type);
1220                                 if (gndo->ndo_dltname != NULL)
1221                                         error("packet printing is not supported for link type %s: use -w",
1222                                               gndo->ndo_dltname);
1223                                 else
1224                                         error("packet printing is not supported for link type %d: use -w", type);
1225                         }
1226                 }
1227                 callback = print_packet;
1228                 pcap_userdata = (u_char *)&printinfo;
1229         }
1230 #ifndef WIN32
1231         /*
1232          * We cannot do this earlier, because we want to be able to open
1233          * the file (if done) for writing before giving up permissions.
1234          */
1235         if (getuid() == 0 || geteuid() == 0) {
1236                 if (username || chroot_dir)
1237                         droproot(username, chroot_dir);
1238         }
1239 #endif /* WIN32 */
1240 #ifdef SIGINFO
1241         /*
1242          * We can't get statistics when reading from a file rather
1243          * than capturing from a device.
1244          */
1245         if (RFileName == NULL)
1246                 (void)setsignal(SIGINFO, requestinfo);
1247 #endif
1248
1249         if (vflag > 0 && WFileName) {
1250                 /*
1251                  * When capturing to a file, "-v" means tcpdump should,
1252                  * every 10 secodns, "v"erbosely report the number of
1253                  * packets captured.
1254                  */
1255 #ifdef USE_WIN32_MM_TIMER
1256                 /* call verbose_stats_dump() each 1000 +/-100msec */
1257                 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1258                 setvbuf(stderr, NULL, _IONBF, 0);
1259 #elif defined(HAVE_ALARM)
1260                 (void)setsignal(SIGALRM, verbose_stats_dump);
1261                 alarm(1);
1262 #endif
1263         }
1264
1265 #ifndef WIN32
1266         if (RFileName == NULL) {
1267                 int dlt;
1268                 const char *dlt_name;
1269
1270                 if (!vflag && !WFileName) {
1271                         (void)fprintf(stderr,
1272                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1273                             program_name);
1274                 } else
1275                         (void)fprintf(stderr, "%s: ", program_name);
1276                 dlt = pcap_datalink(pd);
1277                 dlt_name = pcap_datalink_val_to_name(dlt);
1278                 if (dlt_name == NULL) {
1279                         (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1280                             device, dlt, snaplen);
1281                 } else {
1282                         (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1283                             device, dlt_name,
1284                             pcap_datalink_val_to_description(dlt), snaplen);
1285                 }
1286                 (void)fflush(stderr);
1287         }
1288 #endif /* WIN32 */
1289         status = pcap_loop(pd, cnt, callback, pcap_userdata);
1290         if (WFileName == NULL) {
1291                 /*
1292                  * We're printing packets.  Flush the printed output,
1293                  * so it doesn't get intermingled with error output.
1294                  */
1295                 if (status == -2) {
1296                         /*
1297                          * We got interrupted, so perhaps we didn't
1298                          * manage to finish a line we were printing.
1299                          * Print an extra newline, just in case.
1300                          */
1301                         putchar('\n');
1302                 }
1303                 (void)fflush(stdout);
1304         }
1305         if (status == -1) {
1306                 /*
1307                  * Error.  Report it.
1308                  */
1309                 (void)fprintf(stderr, "%s: pcap_loop: %s\n",
1310                     program_name, pcap_geterr(pd));
1311         }
1312         if (RFileName == NULL) {
1313                 /*
1314                  * We're doing a live capture.  Report the capture
1315                  * statistics.
1316                  */
1317                 info(1);
1318         }
1319         pcap_close(pd);
1320         exit(status == -1 ? 1 : 0);
1321 }
1322
1323 /* make a clean exit on interrupts */
1324 static RETSIGTYPE
1325 cleanup(int signo _U_)
1326 {
1327 #ifdef USE_WIN32_MM_TIMER
1328         if (timer_id)
1329                 timeKillEvent(timer_id);
1330         timer_id = 0;
1331 #elif defined(HAVE_ALARM)
1332         alarm(0);
1333 #endif
1334
1335 #ifdef HAVE_PCAP_BREAKLOOP
1336         /*
1337          * We have "pcap_breakloop()"; use it, so that we do as little
1338          * as possible in the signal handler (it's probably not safe
1339          * to do anything with standard I/O streams in a signal handler -
1340          * the ANSI C standard doesn't say it is).
1341          */
1342         pcap_breakloop(pd);
1343 #else
1344         /*
1345          * We don't have "pcap_breakloop()"; this isn't safe, but
1346          * it's the best we can do.  Print the summary if we're
1347          * not reading from a savefile - i.e., if we're doing a
1348          * live capture - and exit.
1349          */
1350         if (pd != NULL && pcap_file(pd) == NULL) {
1351                 /*
1352                  * We got interrupted, so perhaps we didn't
1353                  * manage to finish a line we were printing.
1354                  * Print an extra newline, just in case.
1355                  */
1356                 putchar('\n');
1357                 (void)fflush(stdout);
1358                 info(1);
1359         }
1360         exit(0);
1361 #endif
1362 }
1363
1364 /*
1365   On windows, we do not use a fork, so we do not care less about
1366   waiting a child processes to die
1367  */
1368 #ifndef WIN32
1369 static RETSIGTYPE
1370 child_cleanup(int signo _U_)
1371 {
1372   wait(NULL);
1373 }
1374 #endif /* WIN32 */
1375
1376 static void
1377 info(register int verbose)
1378 {
1379         struct pcap_stat stat;
1380
1381         /*
1382          * Older versions of libpcap didn't set ps_ifdrop on some
1383          * platforms; initialize it to 0 to handle that.
1384          */
1385         stat.ps_ifdrop = 0;
1386         if (pcap_stats(pd, &stat) < 0) {
1387                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1388                 infoprint = 0;
1389                 return;
1390         }
1391
1392         if (!verbose)
1393                 fprintf(stderr, "%s: ", program_name);
1394
1395         (void)fprintf(stderr, "%u packets captured", packets_captured);
1396         if (!verbose)
1397                 fputs(", ", stderr);
1398         else
1399                 putc('\n', stderr);
1400         (void)fprintf(stderr, "%u packets received by filter", stat.ps_recv);
1401         if (!verbose)
1402                 fputs(", ", stderr);
1403         else
1404                 putc('\n', stderr);
1405         (void)fprintf(stderr, "%u packets dropped by kernel", stat.ps_drop);
1406         if (stat.ps_ifdrop != 0) {
1407                 if (!verbose)
1408                         fputs(", ", stderr);
1409                 else
1410                         putc('\n', stderr);
1411                 (void)fprintf(stderr, "%u packets dropped by interface\n",
1412                     stat.ps_ifdrop);
1413         } else
1414                 putc('\n', stderr);
1415         infoprint = 0;
1416 }
1417
1418 #ifndef WIN32
1419 static void
1420 compress_savefile(const char *filename)
1421 {
1422         if (fork())
1423                 return;
1424         /*
1425          * Set to lowest priority so that this doesn't disturb the capture
1426          */
1427 #ifdef NZERO
1428         setpriority(PRIO_PROCESS, 0, NZERO - 1);
1429 #else
1430         setpriority(PRIO_PROCESS, 0, 19);
1431 #endif
1432         if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
1433                 fprintf(stderr,
1434                         "compress_savefile:execlp(%s, %s): %s\n",
1435                         zflag,
1436                         filename,
1437                         strerror(errno));
1438 }
1439 #else  /* WIN32 */
1440 static void
1441 compress_savefile(const char *filename)
1442 {
1443         fprintf(stderr,
1444                 "compress_savefile failed. Functionality not implemented under windows\n");
1445 }
1446 #endif /* WIN32 */
1447
1448 static void
1449 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1450 {
1451         struct dump_info *dump_info;
1452
1453         ++packets_captured;
1454
1455         ++infodelay;
1456
1457         dump_info = (struct dump_info *)user;
1458
1459         /*
1460          * XXX - this won't force the file to rotate on the specified time
1461          * boundary, but it will rotate on the first packet received after the
1462          * specified Gflag number of seconds. Note: if a Gflag time boundary
1463          * and a Cflag size boundary coincide, the time rotation will occur
1464          * first thereby cancelling the Cflag boundary (since the file should
1465          * be 0).
1466          */
1467         if (Gflag != 0) {
1468                 /* Check if it is time to rotate */
1469                 time_t t;
1470
1471                 /* Get the current time */
1472                 if ((t = time(NULL)) == (time_t)-1) {
1473                         error("dump_and_trunc_packet: can't get current_time: %s",
1474                             pcap_strerror(errno));
1475                 }
1476
1477
1478                 /* If the time is greater than the specified window, rotate */
1479                 if (t - Gflag_time >= Gflag) {
1480                         /* Update the Gflag_time */
1481                         Gflag_time = t;
1482                         /* Update Gflag_count */
1483                         Gflag_count++;
1484                         /*
1485                          * Close the current file and open a new one.
1486                          */
1487                         pcap_dump_close(dump_info->p);
1488
1489                         /*
1490                          * Compress the file we just closed, if the user asked for it
1491                          */
1492                         if (zflag != NULL)
1493                                 compress_savefile(dump_info->CurrentFileName);
1494
1495                         /*
1496                          * Check to see if we've exceeded the Wflag (when
1497                          * not using Cflag).
1498                          */
1499                         if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
1500                                 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
1501                                     Wflag);
1502                                 exit(0);
1503                                 /* NOTREACHED */
1504                         }
1505                         if (dump_info->CurrentFileName != NULL)
1506                                 free(dump_info->CurrentFileName);
1507                         /* Allocate space for max filename + \0. */
1508                         dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1509                         if (dump_info->CurrentFileName == NULL)
1510                                 error("dump_packet_and_trunc: malloc");
1511                         /*
1512                          * This is always the first file in the Cflag
1513                          * rotation: e.g. 0
1514                          * We also don't need numbering if Cflag is not set.
1515                          */
1516                         if (Cflag != 0)
1517                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
1518                                     WflagChars);
1519                         else
1520                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
1521
1522                         dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1523                         if (dump_info->p == NULL)
1524                                 error("%s", pcap_geterr(pd));
1525                 }
1526         }
1527
1528         /*
1529          * XXX - this won't prevent capture files from getting
1530          * larger than Cflag - the last packet written to the
1531          * file could put it over Cflag.
1532          */
1533         if (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) {
1534                 /*
1535                  * Close the current file and open a new one.
1536                  */
1537                 pcap_dump_close(dump_info->p);
1538
1539                 /*
1540                  * Compress the file we just closed, if the user asked for it
1541                  */
1542                 if (zflag != NULL)
1543                         compress_savefile(dump_info->CurrentFileName);
1544
1545                 Cflag_count++;
1546                 if (Wflag > 0) {
1547                         if (Cflag_count >= Wflag)
1548                                 Cflag_count = 0;
1549                 }
1550                 if (dump_info->CurrentFileName != NULL)
1551                         free(dump_info->CurrentFileName);
1552                 dump_info->CurrentFileName = (char *)malloc(NAME_MAX + 1);
1553                 if (dump_info->CurrentFileName == NULL)
1554                         error("dump_packet_and_trunc: malloc");
1555                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
1556                 dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
1557                 if (dump_info->p == NULL)
1558                         error("%s", pcap_geterr(pd));
1559         }
1560
1561         pcap_dump((u_char *)dump_info->p, h, sp);
1562 #ifdef HAVE_PCAP_DUMP_FLUSH
1563         if (Uflag)
1564                 pcap_dump_flush(dump_info->p);
1565 #endif
1566
1567         --infodelay;
1568         if (infoprint)
1569                 info(0);
1570 }
1571
1572 static void
1573 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1574 {
1575         ++packets_captured;
1576
1577         ++infodelay;
1578
1579         pcap_dump(user, h, sp);
1580 #ifdef HAVE_PCAP_DUMP_FLUSH
1581         if (Uflag)
1582                 pcap_dump_flush((pcap_dumper_t *)user);
1583 #endif
1584
1585         --infodelay;
1586         if (infoprint)
1587                 info(0);
1588 }
1589
1590 static void
1591 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1592 {
1593         struct print_info *print_info;
1594         u_int hdrlen;
1595
1596         ++packets_captured;
1597
1598         ++infodelay;
1599         ts_print(&h->ts);
1600
1601         print_info = (struct print_info *)user;
1602
1603         /*
1604          * Some printers want to check that they're not walking off the
1605          * end of the packet.
1606          * Rather than pass it all the way down, we set this global.
1607          */
1608         snapend = sp + h->caplen;
1609
1610         if(print_info->ndo_type) {
1611                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
1612         } else {
1613                 hdrlen = (*print_info->p.printer)(h, sp);
1614         }
1615
1616         if (Xflag) {
1617                 /*
1618                  * Print the raw packet data in hex and ASCII.
1619                  */
1620                 if (Xflag > 1) {
1621                         /*
1622                          * Include the link-layer header.
1623                          */
1624                         hex_and_ascii_print("\n\t", sp, h->caplen);
1625                 } else {
1626                         /*
1627                          * Don't include the link-layer header - and if
1628                          * we have nothing past the link-layer header,
1629                          * print nothing.
1630                          */
1631                         if (h->caplen > hdrlen)
1632                                 hex_and_ascii_print("\n\t", sp + hdrlen,
1633                                     h->caplen - hdrlen);
1634                 }
1635         } else if (xflag) {
1636                 /*
1637                  * Print the raw packet data in hex.
1638                  */
1639                 if (xflag > 1) {
1640                         /*
1641                          * Include the link-layer header.
1642                          */
1643                         hex_print("\n\t", sp, h->caplen);
1644                 } else {
1645                         /*
1646                          * Don't include the link-layer header - and if
1647                          * we have nothing past the link-layer header,
1648                          * print nothing.
1649                          */
1650                         if (h->caplen > hdrlen)
1651                                 hex_print("\n\t", sp + hdrlen,
1652                                     h->caplen - hdrlen);
1653                 }
1654         } else if (Aflag) {
1655                 /*
1656                  * Print the raw packet data in ASCII.
1657                  */
1658                 if (Aflag > 1) {
1659                         /*
1660                          * Include the link-layer header.
1661                          */
1662                         ascii_print(sp, h->caplen);
1663                 } else {
1664                         /*
1665                          * Don't include the link-layer header - and if
1666                          * we have nothing past the link-layer header,
1667                          * print nothing.
1668                          */
1669                         if (h->caplen > hdrlen)
1670                                 ascii_print(sp + hdrlen, h->caplen - hdrlen);
1671                 }
1672         }
1673
1674         putchar('\n');
1675
1676         --infodelay;
1677         if (infoprint)
1678                 info(0);
1679 }
1680
1681 #ifdef WIN32
1682         /*
1683          * XXX - there should really be libpcap calls to get the version
1684          * number as a string (the string would be generated from #defines
1685          * at run time, so that it's not generated from string constants
1686          * in the library, as, on many UNIX systems, those constants would
1687          * be statically linked into the application executable image, and
1688          * would thus reflect the version of libpcap on the system on
1689          * which the application was *linked*, not the system on which it's
1690          * *running*.
1691          *
1692          * That routine should be documented, unlike the "version[]"
1693          * string, so that UNIX vendors providing their own libpcaps
1694          * don't omit it (as a couple of vendors have...).
1695          *
1696          * Packet.dll should perhaps also export a routine to return the
1697          * version number of the Packet.dll code, to supply the
1698          * "Wpcap_version" information on Windows.
1699          */
1700         char WDversion[]="current-cvs.tcpdump.org";
1701 #if !defined(HAVE_GENERATED_VERSION)
1702         char version[]="current-cvs.tcpdump.org";
1703 #endif
1704         char pcap_version[]="current-cvs.tcpdump.org";
1705         char Wpcap_version[]="3.1";
1706 #endif
1707
1708 /*
1709  * By default, print the specified data out in hex and ASCII.
1710  */
1711 static void
1712 ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
1713 {
1714         hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */
1715 }
1716
1717 void
1718 default_print(const u_char *bp, u_int length)
1719 {
1720         ndo_default_print(gndo, bp, length);
1721 }
1722
1723 #ifdef SIGINFO
1724 RETSIGTYPE requestinfo(int signo _U_)
1725 {
1726         if (infodelay)
1727                 ++infoprint;
1728         else
1729                 info(0);
1730 }
1731 #endif
1732
1733 /*
1734  * Called once each second in verbose mode while dumping to file
1735  */
1736 #ifdef USE_WIN32_MM_TIMER
1737 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
1738                                   DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
1739 {
1740         struct pcap_stat stat;
1741
1742         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1743                 fprintf(stderr, "Got %u\r", packets_captured);
1744 }
1745 #elif defined(HAVE_ALARM)
1746 static void verbose_stats_dump(int sig _U_)
1747 {
1748         struct pcap_stat stat;
1749
1750         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
1751                 fprintf(stderr, "Got %u\r", packets_captured);
1752         alarm(1);
1753 }
1754 #endif
1755
1756 static void
1757 usage(void)
1758 {
1759         extern char version[];
1760 #ifndef HAVE_PCAP_LIB_VERSION
1761 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
1762         extern char pcap_version[];
1763 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1764         static char pcap_version[] = "unknown";
1765 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
1766 #endif /* HAVE_PCAP_LIB_VERSION */
1767
1768 #ifdef HAVE_PCAP_LIB_VERSION
1769 #ifdef WIN32
1770         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1771 #else /* WIN32 */
1772         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1773 #endif /* WIN32 */
1774         (void)fprintf(stderr, "%s\n",pcap_lib_version());
1775 #else /* HAVE_PCAP_LIB_VERSION */
1776 #ifdef WIN32
1777         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
1778         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
1779 #else /* WIN32 */
1780         (void)fprintf(stderr, "%s version %s\n", program_name, version);
1781         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
1782 #endif /* WIN32 */
1783 #endif /* HAVE_PCAP_LIB_VERSION */
1784         (void)fprintf(stderr,
1785 "Usage: %s [-aAbd" D_FLAG "ef" I_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
1786         (void)fprintf(stderr,
1787 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
1788         (void)fprintf(stderr,
1789 "\t\t[ -i interface ] [ -M secret ] [ -r file ]\n");
1790         (void)fprintf(stderr,
1791 "\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ]\n");
1792         (void)fprintf(stderr,
1793 "\t\t[ -y datalinktype ] [ -z command ] [ -Z user ]\n");
1794         (void)fprintf(stderr,
1795 "\t\t[ expression ]\n");
1796         exit(1);
1797 }
1798
1799
1800
1801 /* VARARGS */
1802 static void
1803 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
1804 {
1805         va_list ap;
1806
1807         (void)fprintf(stderr, "%s: ", program_name);
1808         va_start(ap, fmt);
1809         (void)vfprintf(stderr, fmt, ap);
1810         va_end(ap);
1811         if (*fmt) {
1812                 fmt += strlen(fmt);
1813                 if (fmt[-1] != '\n')
1814                         (void)fputc('\n', stderr);
1815         }
1816         exit(1);
1817         /* NOTREACHED */
1818 }
1819
1820 /* VARARGS */
1821 static void
1822 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
1823 {
1824         va_list ap;
1825
1826         (void)fprintf(stderr, "%s: WARNING: ", program_name);
1827         va_start(ap, fmt);
1828         (void)vfprintf(stderr, fmt, ap);
1829         va_end(ap);
1830         if (*fmt) {
1831                 fmt += strlen(fmt);
1832                 if (fmt[-1] != '\n')
1833                         (void)fputc('\n', stderr);
1834         }
1835 }