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 #ifdef __FreeBSD__
  72 #include <sys/capsicum.h>
  73 #include <sys/ioccom.h>
  74 #include <sys/types.h>
  75 #include <sys/sysctl.h>
  76 #include <net/bpf.h>
  77 #include <fcntl.h>
  78 #include <libgen.h>
  79 #endif  /* __FreeBSD__ */
  80 #ifndef WIN32
  81 #include <sys/wait.h>
  82 #include <sys/resource.h>
  83 #include <pwd.h>
  84 #include <grp.h>
  85 #include <errno.h>
  86 #endif /* WIN32 */
  87
  88 /* capabilities convinience library */
  89 #ifdef HAVE_CAP_NG_H
  90 #include <cap-ng.h>
  91 #endif /* HAVE_CAP_NG_H */
  92
  93 #include "netdissect.h"
  94 #include "interface.h"
  95 #include "addrtoname.h"
  96 #include "machdep.h"
  97 #include "setsignal.h"
  98 #include "gmt2local.h"
  99 #include "pcap-missing.h"
 100
 101 #ifndef PATH_MAX
 102 #define PATH_MAX 1024
 103 #endif
 104
 105 #ifdef SIGINFO
 106 #define SIGNAL_REQ_INFO SIGINFO
 107 #elif SIGUSR1
 108 #define SIGNAL_REQ_INFO SIGUSR1
 109 #endif
 110
 111 netdissect_options Gndo;
 112 netdissect_options *gndo = &Gndo;
 113
 114 static int dflag;                       /* print filter code */
 115 static int Lflag;                       /* list available data link types and exit */
 116 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 117 static int Jflag;                       /* list available time stamp types */
 118 #endif
 119 static char *zflag = NULL;              /* compress each savefile using a specified command (like gzip or bzip2) */
 120
 121 static int infodelay;
 122 static int infoprint;
 123
 124 char *program_name;
 125
 126 int32_t thiszone;               /* seconds offset from gmt to local time */
 127
 128 /* Forwards */
 129 static RETSIGTYPE cleanup(int);
 130 static RETSIGTYPE child_cleanup(int);
 131 static void usage(void) __attribute__((noreturn));
 132 static void show_dlts_and_exit(const char *device, pcap_t *pd) __attribute__((noreturn));
 133
 134 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 135 static void ndo_default_print(netdissect_options *, const u_char *, u_int);
 136 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 137 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 138 static void droproot(const char *, const char *);
 139 static void ndo_error(netdissect_options *ndo, const char *fmt, ...)
 140      __attribute__ ((noreturn, format (printf, 2, 3)));
 141 static void ndo_warning(netdissect_options *ndo, const char *fmt, ...);
 142
 143 #ifdef SIGNAL_REQ_INFO
 144 RETSIGTYPE requestinfo(int);
 145 #endif
 146
 147 #if defined(USE_WIN32_MM_TIMER)
 148   #include <MMsystem.h>
 149   static UINT timer_id;
 150   static void CALLBACK verbose_stats_dump(UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR);
 151 #elif defined(HAVE_ALARM)
 152   static void verbose_stats_dump(int sig);
 153 #endif
 154
 155 static void info(int);
 156 static u_int packets_captured;
 157
 158 struct printer {
 159         if_printer f;
 160         int type;
 161 };
 162
 163
 164 struct ndo_printer {
 165         if_ndo_printer f;
 166         int type;
 167 };
 168
 169
 170 static struct printer printers[] = {
 171         { arcnet_if_print,      DLT_ARCNET },
 172 #ifdef DLT_ARCNET_LINUX
 173         { arcnet_linux_if_print, DLT_ARCNET_LINUX },
 174 #endif
 175         { token_if_print,       DLT_IEEE802 },
 176 #ifdef DLT_LANE8023
 177         { lane_if_print,        DLT_LANE8023 },
 178 #endif
 179 #ifdef DLT_CIP
 180         { cip_if_print,         DLT_CIP },
 181 #endif
 182 #ifdef DLT_ATM_CLIP
 183         { cip_if_print,         DLT_ATM_CLIP },
 184 #endif
 185         { sl_if_print,          DLT_SLIP },
 186 #ifdef DLT_SLIP_BSDOS
 187         { sl_bsdos_if_print,    DLT_SLIP_BSDOS },
 188 #endif
 189         { ppp_if_print,         DLT_PPP },
 190 #ifdef DLT_PPP_WITHDIRECTION
 191         { ppp_if_print,         DLT_PPP_WITHDIRECTION },
 192 #endif
 193 #ifdef DLT_PPP_BSDOS
 194         { ppp_bsdos_if_print,   DLT_PPP_BSDOS },
 195 #endif
 196         { fddi_if_print,        DLT_FDDI },
 197         { null_if_print,        DLT_NULL },
 198 #ifdef DLT_LOOP
 199         { null_if_print,        DLT_LOOP },
 200 #endif
 201         { raw_if_print,         DLT_RAW },
 202         { atm_if_print,         DLT_ATM_RFC1483 },
 203 #ifdef DLT_C_HDLC
 204         { chdlc_if_print,       DLT_C_HDLC },
 205 #endif
 206 #ifdef DLT_HDLC
 207         { chdlc_if_print,       DLT_HDLC },
 208 #endif
 209 #ifdef DLT_PPP_SERIAL
 210         { ppp_hdlc_if_print,    DLT_PPP_SERIAL },
 211 #endif
 212 #ifdef DLT_PPP_ETHER
 213         { pppoe_if_print,       DLT_PPP_ETHER },
 214 #endif
 215 #ifdef DLT_LINUX_SLL
 216         { sll_if_print,         DLT_LINUX_SLL },
 217 #endif
 218 #ifdef DLT_IEEE802_11
 219         { ieee802_11_if_print,  DLT_IEEE802_11},
 220 #endif
 221 #ifdef DLT_LTALK
 222         { ltalk_if_print,       DLT_LTALK },
 223 #endif
 224 #if defined(DLT_PFLOG) && defined(HAVE_NET_PFVAR_H)
 225         { pflog_if_print,       DLT_PFLOG },
 226 #endif
 227 #ifdef DLT_FR
 228         { fr_if_print,          DLT_FR },
 229 #endif
 230 #ifdef DLT_FRELAY
 231         { fr_if_print,          DLT_FRELAY },
 232 #endif
 233 #ifdef DLT_SUNATM
 234         { sunatm_if_print,      DLT_SUNATM },
 235 #endif
 236 #ifdef DLT_IP_OVER_FC
 237         { ipfc_if_print,        DLT_IP_OVER_FC },
 238 #endif
 239 #ifdef DLT_PRISM_HEADER
 240         { prism_if_print,       DLT_PRISM_HEADER },
 241 #endif
 242 #ifdef DLT_IEEE802_11_RADIO
 243         { ieee802_11_radio_if_print,    DLT_IEEE802_11_RADIO },
 244 #endif
 245 #ifdef DLT_ENC
 246         { enc_if_print,         DLT_ENC },
 247 #endif
 248 #ifdef DLT_SYMANTEC_FIREWALL
 249         { symantec_if_print,    DLT_SYMANTEC_FIREWALL },
 250 #endif
 251 #ifdef DLT_APPLE_IP_OVER_IEEE1394
 252         { ap1394_if_print,      DLT_APPLE_IP_OVER_IEEE1394 },
 253 #endif
 254 #ifdef DLT_IEEE802_11_RADIO_AVS
 255         { ieee802_11_radio_avs_if_print,        DLT_IEEE802_11_RADIO_AVS },
 256 #endif
 257 #ifdef DLT_JUNIPER_ATM1
 258         { juniper_atm1_print,   DLT_JUNIPER_ATM1 },
 259 #endif
 260 #ifdef DLT_JUNIPER_ATM2
 261         { juniper_atm2_print,   DLT_JUNIPER_ATM2 },
 262 #endif
 263 #ifdef DLT_JUNIPER_MFR
 264         { juniper_mfr_print,    DLT_JUNIPER_MFR },
 265 #endif
 266 #ifdef DLT_JUNIPER_MLFR
 267         { juniper_mlfr_print,   DLT_JUNIPER_MLFR },
 268 #endif
 269 #ifdef DLT_JUNIPER_MLPPP
 270         { juniper_mlppp_print,  DLT_JUNIPER_MLPPP },
 271 #endif
 272 #ifdef DLT_JUNIPER_PPPOE
 273         { juniper_pppoe_print,  DLT_JUNIPER_PPPOE },
 274 #endif
 275 #ifdef DLT_JUNIPER_PPPOE_ATM
 276         { juniper_pppoe_atm_print, DLT_JUNIPER_PPPOE_ATM },
 277 #endif
 278 #ifdef DLT_JUNIPER_GGSN
 279         { juniper_ggsn_print,   DLT_JUNIPER_GGSN },
 280 #endif
 281 #ifdef DLT_JUNIPER_ES
 282         { juniper_es_print,     DLT_JUNIPER_ES },
 283 #endif
 284 #ifdef DLT_JUNIPER_MONITOR
 285         { juniper_monitor_print, DLT_JUNIPER_MONITOR },
 286 #endif
 287 #ifdef DLT_JUNIPER_SERVICES
 288         { juniper_services_print, DLT_JUNIPER_SERVICES },
 289 #endif
 290 #ifdef DLT_JUNIPER_ETHER
 291         { juniper_ether_print,  DLT_JUNIPER_ETHER },
 292 #endif
 293 #ifdef DLT_JUNIPER_PPP
 294         { juniper_ppp_print,    DLT_JUNIPER_PPP },
 295 #endif
 296 #ifdef DLT_JUNIPER_FRELAY
 297         { juniper_frelay_print, DLT_JUNIPER_FRELAY },
 298 #endif
 299 #ifdef DLT_JUNIPER_CHDLC
 300         { juniper_chdlc_print,  DLT_JUNIPER_CHDLC },
 301 #endif
 302 #ifdef DLT_MFR
 303         { mfr_if_print,         DLT_MFR },
 304 #endif
 305 #if defined(DLT_BLUETOOTH_HCI_H4_WITH_PHDR) && defined(HAVE_PCAP_BLUETOOTH_H)
 306         { bt_if_print,          DLT_BLUETOOTH_HCI_H4_WITH_PHDR},
 307 #endif
 308 #ifdef HAVE_PCAP_USB_H
 309 #ifdef DLT_USB_LINUX
 310         { usb_linux_48_byte_print, DLT_USB_LINUX},
 311 #endif /* DLT_USB_LINUX */
 312 #ifdef DLT_USB_LINUX_MMAPPED
 313         { usb_linux_64_byte_print, DLT_USB_LINUX_MMAPPED},
 314 #endif /* DLT_USB_LINUX_MMAPPED */
 315 #endif /* HAVE_PCAP_USB_H */
 316 #ifdef DLT_IPV4
 317         { raw_if_print,         DLT_IPV4 },
 318 #endif
 319 #ifdef DLT_IPV6
 320         { raw_if_print,         DLT_IPV6 },
 321 #endif
 322         { NULL,                 0 },
 323 };
 324
 325 static struct ndo_printer ndo_printers[] = {
 326         { ether_if_print,       DLT_EN10MB },
 327 #ifdef DLT_IPNET
 328         { ipnet_if_print,       DLT_IPNET },
 329 #endif
 330 #ifdef DLT_IEEE802_15_4
 331         { ieee802_15_4_if_print, DLT_IEEE802_15_4 },
 332 #endif
 333 #ifdef DLT_IEEE802_15_4_NOFCS
 334         { ieee802_15_4_if_print, DLT_IEEE802_15_4_NOFCS },
 335 #endif
 336 #ifdef DLT_PPI
 337         { ppi_if_print,         DLT_PPI },
 338 #endif
 339 #ifdef DLT_NETANALYZER
 340         { netanalyzer_if_print, DLT_NETANALYZER },
 341 #endif
 342 #ifdef DLT_NETANALYZER_TRANSPARENT
 343         { netanalyzer_transparent_if_print, DLT_NETANALYZER_TRANSPARENT },
 344 #endif
 345         { NULL,                 0 },
 346 };
 347
 348 if_printer
 349 lookup_printer(int type)
 350 {
 351         struct printer *p;
 352
 353         for (p = printers; p->f; ++p)
 354                 if (type == p->type)
 355                         return p->f;
 356
 357         return NULL;
 358         /* NOTREACHED */
 359 }
 360
 361 if_ndo_printer
 362 lookup_ndo_printer(int type)
 363 {
 364         struct ndo_printer *p;
 365
 366         for (p = ndo_printers; p->f; ++p)
 367                 if (type == p->type)
 368                         return p->f;
 369
 370         return NULL;
 371         /* NOTREACHED */
 372 }
 373
 374 static pcap_t *pd;
 375
 376 static int supports_monitor_mode;
 377
 378 extern int optind;
 379 extern int opterr;
 380 extern char *optarg;
 381
 382 struct print_info {
 383         netdissect_options *ndo;
 384         union {
 385                 if_printer     printer;
 386                 if_ndo_printer ndo_printer;
 387         } p;
 388         int ndo_type;
 389 };
 390
 391 struct dump_info {
 392         char    *WFileName;
 393         char    *CurrentFileName;
 394         pcap_t  *pd;
 395         pcap_dumper_t *p;
 396 #ifdef __FreeBSD__
 397         int     dirfd;
 398 #endif
 399 };
 400
 401 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 402 static void
 403 show_tstamp_types_and_exit(const char *device, pcap_t *pd)
 404 {
 405         int n_tstamp_types;
 406         int *tstamp_types = 0;
 407         const char *tstamp_type_name;
 408         int i;
 409
 410         n_tstamp_types = pcap_list_tstamp_types(pd, &tstamp_types);
 411         if (n_tstamp_types < 0)
 412                 error("%s", pcap_geterr(pd));
 413
 414         if (n_tstamp_types == 0) {
 415                 fprintf(stderr, "Time stamp type cannot be set for %s\n",
 416                     device);
 417                 exit(0);
 418         }
 419         fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
 420             device);
 421         for (i = 0; i < n_tstamp_types; i++) {
 422                 tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
 423                 if (tstamp_type_name != NULL) {
 424                         (void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
 425                             pcap_tstamp_type_val_to_description(tstamp_types[i]));
 426                 } else {
 427                         (void) fprintf(stderr, "  %d\n", tstamp_types[i]);
 428                 }
 429         }
 430         pcap_free_tstamp_types(tstamp_types);
 431         exit(0);
 432 }
 433 #endif
 434
 435 static void
 436 show_dlts_and_exit(const char *device, pcap_t *pd)
 437 {
 438         int n_dlts;
 439         int *dlts = 0;
 440         const char *dlt_name;
 441
 442         n_dlts = pcap_list_datalinks(pd, &dlts);
 443         if (n_dlts < 0)
 444                 error("%s", pcap_geterr(pd));
 445         else if (n_dlts == 0 || !dlts)
 446                 error("No data link types.");
 447
 448         /*
 449          * If the interface is known to support monitor mode, indicate
 450          * whether these are the data link types available when not in
 451          * monitor mode, if -I wasn't specified, or when in monitor mode,
 452          * when -I was specified (the link-layer types available in
 453          * monitor mode might be different from the ones available when
 454          * not in monitor mode).
 455          */
 456         if (supports_monitor_mode)
 457                 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
 458                     device,
 459                     Iflag ? "when in monitor mode" : "when not in monitor mode");
 460         else
 461                 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
 462                     device);
 463
 464         while (--n_dlts >= 0) {
 465                 dlt_name = pcap_datalink_val_to_name(dlts[n_dlts]);
 466                 if (dlt_name != NULL) {
 467                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 468                             pcap_datalink_val_to_description(dlts[n_dlts]));
 469
 470                         /*
 471                          * OK, does tcpdump handle that type?
 472                          */
 473                         if (lookup_printer(dlts[n_dlts]) == NULL
 474                             && lookup_ndo_printer(dlts[n_dlts]) == NULL)
 475                                 (void) fprintf(stderr, " (printing not supported)");
 476                         fprintf(stderr, "\n");
 477                 } else {
 478                         (void) fprintf(stderr, "  DLT %d (printing not supported)\n",
 479                             dlts[n_dlts]);
 480                 }
 481         }
 482 #ifdef HAVE_PCAP_FREE_DATALINKS
 483         pcap_free_datalinks(dlts);
 484 #endif
 485         exit(0);
 486 }
 487
 488 /*
 489  * Set up flags that might or might not be supported depending on the
 490  * version of libpcap we're using.
 491  */
 492 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 493 #define B_FLAG          "B:"
 494 #define B_FLAG_USAGE    " [ -B size ]"
 495 #else /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 496 #define B_FLAG
 497 #define B_FLAG_USAGE
 498 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 499
 500 #ifdef HAVE_PCAP_CREATE
 501 #define I_FLAG          "I"
 502 #else /* HAVE_PCAP_CREATE */
 503 #define I_FLAG
 504 #endif /* HAVE_PCAP_CREATE */
 505
 506 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 507 #define j_FLAG          "j:"
 508 #define j_FLAG_USAGE    " [ -j tstamptype ]"
 509 #define J_FLAG          "J"
 510 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 511 #define j_FLAG
 512 #define j_FLAG_USAGE
 513 #define J_FLAG
 514 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 515
 516 #ifdef HAVE_PCAP_FINDALLDEVS
 517 #ifndef HAVE_PCAP_IF_T
 518 #undef HAVE_PCAP_FINDALLDEVS
 519 #endif
 520 #endif
 521
 522 #ifdef HAVE_PCAP_FINDALLDEVS
 523 #define D_FLAG  "D"
 524 #else
 525 #define D_FLAG
 526 #endif
 527
 528 #ifdef HAVE_PCAP_DUMP_FLUSH
 529 #define U_FLAG  "U"
 530 #else
 531 #define U_FLAG
 532 #endif
 533
 534 #ifndef WIN32
 535 /* Drop root privileges and chroot if necessary */
 536 static void
 537 droproot(const char *username, const char *chroot_dir)
 538 {
 539         struct passwd *pw = NULL;
 540
 541         if (chroot_dir && !username) {
 542                 fprintf(stderr, "tcpdump: Chroot without dropping root is insecure\n");
 543                 exit(1);
 544         }
 545
 546         pw = getpwnam(username);
 547         if (pw) {
 548                 if (chroot_dir) {
 549                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0) {
 550                                 fprintf(stderr, "tcpdump: Couldn't chroot/chdir to '%.64s': %s\n",
 551                                     chroot_dir, pcap_strerror(errno));
 552                                 exit(1);
 553                         }
 554                 }
 555 #ifdef HAVE_CAP_NG_H
 556                 int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
 557                 if (ret < 0) {
 558                         printf("error : ret %d\n", ret);
 559                 }
 560                 /* We don't need CAP_SETUID and CAP_SETGID */
 561                 capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_SETUID);
 562                 capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_SETUID);
 563                 capng_update(CAPNG_DROP, CAPNG_PERMITTED, CAP_SETUID);
 564                 capng_update(CAPNG_DROP, CAPNG_PERMITTED, CAP_SETUID);
 565                 capng_apply(CAPNG_SELECT_BOTH);
 566
 567 #else
 568                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 569                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) {
 570                         fprintf(stderr, "tcpdump: Couldn't change to '%.32s' uid=%lu gid=%lu: %s\n",
 571                             username,
 572                             (unsigned long)pw->pw_uid,
 573                             (unsigned long)pw->pw_gid,
 574                             pcap_strerror(errno));
 575                         exit(1);
 576                 }
 577 #endif /* HAVE_CAP_NG_H */
 578         }
 579         else {
 580                 fprintf(stderr, "tcpdump: Couldn't find user '%.32s'\n",
 581                     username);
 582                 exit(1);
 583         }
 584 }
 585 #endif /* WIN32 */
 586
 587 static int
 588 getWflagChars(int x)
 589 {
 590         int c = 0;
 591
 592         x -= 1;
 593         while (x > 0) {
 594                 c += 1;
 595                 x /= 10;
 596         }
 597
 598         return c;
 599 }
 600
 601
 602 static void
 603 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 604 {
 605         char *filename = malloc(PATH_MAX + 1);
 606         if (filename == NULL)
 607             error("Makefilename: malloc");
 608
 609         /* Process with strftime if Gflag is set. */
 610         if (Gflag != 0) {
 611           struct tm *local_tm;
 612
 613           /* Convert Gflag_time to a usable format */
 614           if ((local_tm = localtime(&Gflag_time)) == NULL) {
 615                   error("MakeTimedFilename: localtime");
 616           }
 617
 618           /* There's no good way to detect an error in strftime since a return
 619            * value of 0 isn't necessarily failure.
 620            */
 621           strftime(filename, PATH_MAX, orig_name, local_tm);
 622         } else {
 623           strncpy(filename, orig_name, PATH_MAX);
 624         }
 625
 626         if (cnt == 0 && max_chars == 0)
 627                 strncpy(buffer, filename, PATH_MAX + 1);
 628         else
 629                 if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
 630                   /* Report an error if the filename is too large */
 631                   error("too many output files or filename is too long (> %d)", PATH_MAX);
 632         free(filename);
 633 }
 634
 635 static int tcpdump_printf(netdissect_options *ndo _U_,
 636                           const char *fmt, ...)
 637 {
 638
 639   va_list args;
 640   int ret;
 641
 642   va_start(args, fmt);
 643   ret=vfprintf(stdout, fmt, args);
 644   va_end(args);
 645
 646   return ret;
 647 }
 648
 649 static struct print_info
 650 get_print_info(int type)
 651 {
 652         struct print_info printinfo;
 653
 654         printinfo.ndo_type = 1;
 655         printinfo.ndo = gndo;
 656         printinfo.p.ndo_printer = lookup_ndo_printer(type);
 657         if (printinfo.p.ndo_printer == NULL) {
 658                 printinfo.p.printer = lookup_printer(type);
 659                 printinfo.ndo_type = 0;
 660                 if (printinfo.p.printer == NULL) {
 661                         gndo->ndo_dltname = pcap_datalink_val_to_name(type);
 662                         if (gndo->ndo_dltname != NULL)
 663                                 error("packet printing is not supported for link type %s: use -w",
 664                                       gndo->ndo_dltname);
 665                         else
 666                                 error("packet printing is not supported for link type %d: use -w", type);
 667                 }
 668         }
 669         return (printinfo);
 670 }
 671
 672 static char *
 673 get_next_file(FILE *VFile, char *ptr)
 674 {
 675         char *ret;
 676
 677         ret = fgets(ptr, PATH_MAX, VFile);
 678         if (!ret)
 679                 return NULL;
 680
 681         if (ptr[strlen(ptr) - 1] == '\n')
 682                 ptr[strlen(ptr) - 1] = '\0';
 683
 684         return ret;
 685 }
 686
 687 #ifdef __FreeBSD__
 688 /*
 689  * Ensure that, on a dump file's descriptor, we have all the rights
 690  * necessary to make the standard I/O library work with an fdopen()ed
 691  * FILE * from that descriptor.
 692  *
 693  * A long time ago, in a galaxy far far away, AT&T decided that, instead
 694  * of providing separate APIs for getting and setting the FD_ flags on a
 695  * descriptor, getting and setting the O_ flags on a descriptor, and
 696  * locking files, they'd throw them all into a kitchen-sink fcntl() call
 697  * along the lines of ioctl(), the fact that ioctl() operations are
 698  * largely specific to particular character devices but fcntl() operations
 699  * are either generic to all descriptors or generic to all descriptors for
 700  * regular files nonwithstanding.
 701  *
 702  * The Capsicum people decided that fine-grained control of descriptor
 703  * operations was required, so that you need to grant permission for
 704  * reading, writing, seeking, and fcntl-ing.  The latter, courtesy of
 705  * AT&T's decision, means that "fcntl-ing" isn't a thing, but a motley
 706  * collection of things, so there are *individual* fcntls for which
 707  * permission needs to be granted.
 708  *
 709  * The FreeBSD standard I/O people implemented some optimizations that
 710  * requires that the standard I/O routines be able to determine whether
 711  * the descriptor for the FILE * is open append-only or not; as that
 712  * descriptor could have come from an open() rather than an fopen(),
 713  * that requires that it be able to do an F_GETFL fcntl() to read
 714  * the O_ flags.
 715  *
 716  * Tcpdump uses ftell() to determine how much data has been written
 717  * to a file in order to, when used with -C, determine when it's time
 718  * to rotate capture files.  ftell() therefore needs to do an lseek()
 719  * to find out the file offset and must, thanks to the aforementioned
 720  * optimization, also know whether the descriptor is open append-only
 721  * or not.
 722  *
 723  * The net result of all the above is that we need to grant CAP_SEEK,
 724  * CAP_WRITE, and CAP_FCNTL with the CAP_FCNTL_GETFL subcapability.
 725  *
 726  * Perhaps this is the universe's way of saying that either
 727  *
 728  *      1) there needs to be an fopenat() call and a pcap_dump_openat() call
 729  *         using it, so that Capsicum-capable tcpdump wouldn't need to do
 730  *         an fdopen()
 731  *
 732  * or
 733  *
 734  *      2) there needs to be a cap_fdopen() call in the FreeBSD standard
 735  *         I/O library that knows what rights are needed by the standard
 736  *         I/O library, based on the open mode, and assigns them, perhaps
 737  *         with an additional argument indicating, for example, whether
 738  *         seeking should be allowed, so that tcpdump doesn't need to know
 739  *         what the standard I/O library happens to require this week.
 740  */
 741 static void
 742 set_dumper_capsicum_rights(pcap_dumper_t *p)
 743 {
 744         int fd = fileno(pcap_dump_file(p));
 745         cap_rights_t rights;
 746
 747         cap_rights_init(&rights, CAP_SEEK, CAP_WRITE, CAP_FCNTL);
 748         if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
 749                 error("unable to limit dump descriptor");
 750         }
 751         if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS) {
 752                 error("unable to limit dump descriptor fcntls");
 753         }
 754 }
 755 #endif
 756
 757 int
 758 main(int argc, char **argv)
 759 {
 760         register int cnt, op, i;
 761         bpf_u_int32 localnet, netmask;
 762         register char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
 763         pcap_handler callback;
 764         int type;
 765         int dlt;
 766         int new_dlt;
 767         const char *dlt_name;
 768         struct bpf_program fcode;
 769 #ifndef WIN32
 770         RETSIGTYPE (*oldhandler)(int);
 771 #endif
 772         struct print_info printinfo;
 773         struct dump_info dumpinfo;
 774         u_char *pcap_userdata;
 775         char ebuf[PCAP_ERRBUF_SIZE];
 776         char VFileLine[PATH_MAX + 1];
 777         char *username = NULL;
 778         char *chroot_dir = NULL;
 779         char *ret = NULL;
 780         char *end;
 781 #ifdef HAVE_PCAP_FINDALLDEVS
 782         pcap_if_t *devpointer;
 783         int devnum;
 784 #endif
 785         int status;
 786         FILE *VFile;
 787 #ifdef __FreeBSD__
 788         cap_rights_t rights;
 789         int cansandbox;
 790 #endif  /* __FreeBSD__ */
 791
 792 #ifdef WIN32
 793         if(wsockinit() != 0) return 1;
 794 #endif /* WIN32 */
 795
 796         jflag=-1;       /* not set */
 797         gndo->ndo_Oflag=1;
 798         gndo->ndo_Rflag=1;
 799         gndo->ndo_dlt=-1;
 800         gndo->ndo_default_print=ndo_default_print;
 801         gndo->ndo_printf=tcpdump_printf;
 802         gndo->ndo_error=ndo_error;
 803         gndo->ndo_warning=ndo_warning;
 804         gndo->ndo_snaplen = DEFAULT_SNAPLEN;
 805
 806         cnt = -1;
 807         device = NULL;
 808         infile = NULL;
 809         RFileName = NULL;
 810         VFileName = NULL;
 811         VFile = NULL;
 812         WFileName = NULL;
 813         dlt = -1;
 814         if ((cp = strrchr(argv[0], '/')) != NULL)
 815                 program_name = cp + 1;
 816         else
 817                 program_name = argv[0];
 818
 819         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
 820                 error("%s", ebuf);
 821
 822 #ifdef LIBSMI
 823         smiInit("tcpdump");
 824 #endif
 825
 826         while (
 827             (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 "V:vw:W:xXy:Yz:Z:")) != -1)
 828                 switch (op) {
 829
 830                 case 'a':
 831                         /* compatibility for old -a */
 832                         break;
 833
 834                 case 'A':
 835                         ++Aflag;
 836                         break;
 837
 838                 case 'b':
 839                         ++bflag;
 840                         break;
 841
 842 #if defined(HAVE_PCAP_CREATE) || defined(WIN32)
 843                 case 'B':
 844                         Bflag = atoi(optarg)*1024;
 845                         if (Bflag <= 0)
 846                                 error("invalid packet buffer size %s", optarg);
 847                         break;
 848 #endif /* defined(HAVE_PCAP_CREATE) || defined(WIN32) */
 849
 850                 case 'c':
 851                         cnt = atoi(optarg);
 852                         if (cnt <= 0)
 853                                 error("invalid packet count %s", optarg);
 854                         break;
 855
 856                 case 'C':
 857                         Cflag = atoi(optarg) * 1000000;
 858                         if (Cflag < 0)
 859                                 error("invalid file size %s", optarg);
 860                         break;
 861
 862                 case 'd':
 863                         ++dflag;
 864                         break;
 865
 866 #ifdef HAVE_PCAP_FINDALLDEVS
 867                 case 'D':
 868                         if (pcap_findalldevs(&devpointer, ebuf) < 0)
 869                                 error("%s", ebuf);
 870                         else {
 871                                 for (i = 0; devpointer != 0; i++) {
 872                                         printf("%d.%s", i+1, devpointer->name);
 873                                         if (devpointer->description != NULL)
 874                                                 printf(" (%s)", devpointer->description);
 875                                         printf("\n");
 876                                         devpointer = devpointer->next;
 877                                 }
 878                         }
 879                         return 0;
 880 #endif /* HAVE_PCAP_FINDALLDEVS */
 881
 882                 case 'L':
 883                         Lflag++;
 884                         break;
 885
 886                 case 'e':
 887                         ++eflag;
 888                         break;
 889
 890                 case 'E':
 891 #ifndef HAVE_LIBCRYPTO
 892                         warning("crypto code not compiled in");
 893 #endif
 894                         gndo->ndo_espsecret = optarg;
 895                         break;
 896
 897                 case 'f':
 898                         ++fflag;
 899                         break;
 900
 901                 case 'F':
 902                         infile = optarg;
 903                         break;
 904
 905                 case 'G':
 906                         Gflag = atoi(optarg);
 907                         if (Gflag < 0)
 908                                 error("invalid number of seconds %s", optarg);
 909
 910                         /* We will create one file initially. */
 911                         Gflag_count = 0;
 912
 913                         /* Grab the current time for rotation use. */
 914                         if ((Gflag_time = time(NULL)) == (time_t)-1) {
 915                                 error("main: can't get current time: %s",
 916                                     pcap_strerror(errno));
 917                         }
 918                         break;
 919
 920                 case 'h':
 921                         usage();
 922                         break;
 923
 924                 case 'H':
 925                         ++Hflag;
 926                         break;
 927
 928                 case 'i':
 929                         if (optarg[0] == '0' && optarg[1] == 0)
 930                                 error("Invalid adapter index");
 931
 932 #ifdef HAVE_PCAP_FINDALLDEVS
 933                         /*
 934                          * If the argument is a number, treat it as
 935                          * an index into the list of adapters, as
 936                          * printed by "tcpdump -D".
 937                          *
 938                          * This should be OK on UNIX systems, as interfaces
 939                          * shouldn't have names that begin with digits.
 940                          * It can be useful on Windows, where more than
 941                          * one interface can have the same name.
 942                          */
 943                         devnum = strtol(optarg, &end, 10);
 944                         if (optarg != end && *end == '\0') {
 945                                 if (devnum < 0)
 946                                         error("Invalid adapter index");
 947
 948                                 if (pcap_findalldevs(&devpointer, ebuf) < 0)
 949                                         error("%s", ebuf);
 950                                 else {
 951                                         /*
 952                                          * Look for the devnum-th entry
 953                                          * in the list of devices
 954                                          * (1-based).
 955                                          */
 956                                         for (i = 0;
 957                                             i < devnum-1 && devpointer != NULL;
 958                                             i++, devpointer = devpointer->next)
 959                                                 ;
 960                                         if (devpointer == NULL)
 961                                                 error("Invalid adapter index");
 962                                 }
 963                                 device = devpointer->name;
 964                                 break;
 965                         }
 966 #endif /* HAVE_PCAP_FINDALLDEVS */
 967                         device = optarg;
 968                         break;
 969
 970 #ifdef HAVE_PCAP_CREATE
 971                 case 'I':
 972                         ++Iflag;
 973                         break;
 974 #endif /* HAVE_PCAP_CREATE */
 975
 976 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 977                 case 'j':
 978                         jflag = pcap_tstamp_type_name_to_val(optarg);
 979                         if (jflag < 0)
 980                                 error("invalid time stamp type %s", optarg);
 981                         break;
 982
 983                 case 'J':
 984                         Jflag++;
 985                         break;
 986 #endif
 987
 988                 case 'l':
 989 #ifdef WIN32
 990                         /*
 991                          * _IOLBF is the same as _IOFBF in Microsoft's C
 992                          * libraries; the only alternative they offer
 993                          * is _IONBF.
 994                          *
 995                          * XXX - this should really be checking for MSVC++,
 996                          * not WIN32, if, for example, MinGW has its own
 997                          * C library that is more UNIX-compatible.
 998                          */
 999                         setvbuf(stdout, NULL, _IONBF, 0);
1000 #else /* WIN32 */
1001 #ifdef HAVE_SETLINEBUF
1002                         setlinebuf(stdout);
1003 #else
1004                         setvbuf(stdout, NULL, _IOLBF, 0);
1005 #endif
1006 #endif /* WIN32 */
1007                         break;
1008
1009                 case 'K':
1010                         ++Kflag;
1011                         break;
1012
1013                 case 'm':
1014 #ifdef LIBSMI
1015                         if (smiLoadModule(optarg) == 0) {
1016                                 error("could not load MIB module %s", optarg);
1017                         }
1018                         sflag = 1;
1019 #else
1020                         (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
1021                                       program_name, optarg);
1022                         (void)fprintf(stderr, "(no libsmi support)\n");
1023 #endif
1024                         break;
1025
1026                 case 'M':
1027                         /* TCP-MD5 shared secret */
1028 #ifndef HAVE_LIBCRYPTO
1029                         warning("crypto code not compiled in");
1030 #endif
1031                         sigsecret = optarg;
1032                         break;
1033
1034                 case 'n':
1035                         ++nflag;
1036                         break;
1037
1038                 case 'N':
1039                         ++Nflag;
1040                         break;
1041
1042                 case 'O':
1043                         Oflag = 0;
1044                         break;
1045
1046                 case 'p':
1047                         ++pflag;
1048                         break;
1049
1050                 case 'q':
1051                         ++qflag;
1052                         ++suppress_default_print;
1053                         break;
1054
1055                 case 'r':
1056                         RFileName = optarg;
1057                         break;
1058
1059                 case 'R':
1060                         Rflag = 0;
1061                         break;
1062
1063                 case 's':
1064                         snaplen = strtol(optarg, &end, 0);
1065                         if (optarg == end || *end != '\0'
1066                             || snaplen < 0 || snaplen > MAXIMUM_SNAPLEN)
1067                                 error("invalid snaplen %s", optarg);
1068                         else if (snaplen == 0)
1069                                 snaplen = MAXIMUM_SNAPLEN;
1070                         break;
1071
1072                 case 'S':
1073                         ++Sflag;
1074                         break;
1075
1076                 case 't':
1077                         ++tflag;
1078                         break;
1079
1080                 case 'T':
1081                         if (strcasecmp(optarg, "vat") == 0)
1082                                 packettype = PT_VAT;
1083                         else if (strcasecmp(optarg, "wb") == 0)
1084                                 packettype = PT_WB;
1085                         else if (strcasecmp(optarg, "rpc") == 0)
1086                                 packettype = PT_RPC;
1087                         else if (strcasecmp(optarg, "rtp") == 0)
1088                                 packettype = PT_RTP;
1089                         else if (strcasecmp(optarg, "rtcp") == 0)
1090                                 packettype = PT_RTCP;
1091                         else if (strcasecmp(optarg, "snmp") == 0)
1092                                 packettype = PT_SNMP;
1093                         else if (strcasecmp(optarg, "cnfp") == 0)
1094                                 packettype = PT_CNFP;
1095                         else if (strcasecmp(optarg, "tftp") == 0)
1096                                 packettype = PT_TFTP;
1097                         else if (strcasecmp(optarg, "aodv") == 0)
1098                                 packettype = PT_AODV;
1099                         else if (strcasecmp(optarg, "carp") == 0)
1100                                 packettype = PT_CARP;
1101                         else if (strcasecmp(optarg, "radius") == 0)
1102                                 packettype = PT_RADIUS;
1103                         else if (strcasecmp(optarg, "zmtp1") == 0)
1104                                 packettype = PT_ZMTP1;
1105                         else if (strcasecmp(optarg, "vxlan") == 0)
1106                                 packettype = PT_VXLAN;
1107                         else
1108                                 error("unknown packet type `%s'", optarg);
1109                         break;
1110
1111                 case 'u':
1112                         ++uflag;
1113                         break;
1114
1115 #ifdef HAVE_PCAP_DUMP_FLUSH
1116                 case 'U':
1117                         ++Uflag;
1118                         break;
1119 #endif
1120
1121                 case 'v':
1122                         ++vflag;
1123                         break;
1124
1125                 case 'V':
1126                         VFileName = optarg;
1127                         break;
1128
1129                 case 'w':
1130                         WFileName = optarg;
1131                         break;
1132
1133                 case 'W':
1134                         Wflag = atoi(optarg);
1135                         if (Wflag < 0)
1136                                 error("invalid number of output files %s", optarg);
1137                         WflagChars = getWflagChars(Wflag);
1138                         break;
1139
1140                 case 'x':
1141                         ++xflag;
1142                         ++suppress_default_print;
1143                         break;
1144
1145                 case 'X':
1146                         ++Xflag;
1147                         ++suppress_default_print;
1148                         break;
1149
1150                 case 'y':
1151                         gndo->ndo_dltname = optarg;
1152                         gndo->ndo_dlt =
1153                           pcap_datalink_name_to_val(gndo->ndo_dltname);
1154                         if (gndo->ndo_dlt < 0)
1155                                 error("invalid data link type %s", gndo->ndo_dltname);
1156                         break;
1157
1158 #if defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
1159                 case 'Y':
1160                         {
1161                         /* Undocumented flag */
1162 #ifdef HAVE_PCAP_DEBUG
1163                         extern int pcap_debug;
1164                         pcap_debug = 1;
1165 #else
1166                         extern int yydebug;
1167                         yydebug = 1;
1168 #endif
1169                         }
1170                         break;
1171 #endif
1172                 case 'z':
1173                         if (optarg) {
1174                                 zflag = strdup(optarg);
1175                         } else {
1176                                 usage();
1177                                 /* NOTREACHED */
1178                         }
1179                         break;
1180
1181                 case 'Z':
1182                         if (optarg) {
1183                                 username = strdup(optarg);
1184                         }
1185                         else {
1186                                 usage();
1187                                 /* NOTREACHED */
1188                         }
1189                         break;
1190
1191                 default:
1192                         usage();
1193                         /* NOTREACHED */
1194                 }
1195
1196         switch (tflag) {
1197
1198         case 0: /* Default */
1199         case 4: /* Default + Date*/
1200                 thiszone = gmt2local(0);
1201                 break;
1202
1203         case 1: /* No time stamp */
1204         case 2: /* Unix timeval style */
1205         case 3: /* Microseconds since previous packet */
1206         case 5: /* Microseconds since first packet */
1207                 break;
1208
1209         default: /* Not supported */
1210                 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1211                 break;
1212         }
1213
1214         if (fflag != 0 && (VFileName != NULL || RFileName != NULL))
1215                 error("-f can not be used with -V or -r");
1216
1217         if (VFileName != NULL && RFileName != NULL)
1218                 error("-V and -r are mutually exclusive.");
1219
1220 #ifdef WITH_CHROOT
1221         /* if run as root, prepare for chrooting */
1222         if (getuid() == 0 || geteuid() == 0) {
1223                 /* future extensibility for cmd-line arguments */
1224                 if (!chroot_dir)
1225                         chroot_dir = WITH_CHROOT;
1226         }
1227 #endif
1228
1229 #ifdef WITH_USER
1230         /* if run as root, prepare for dropping root privileges */
1231         if (getuid() == 0 || geteuid() == 0) {
1232                 /* Run with '-Z root' to restore old behaviour */
1233                 if (!username)
1234                         username = WITH_USER;
1235         }
1236 #endif
1237
1238         if (RFileName != NULL || VFileName != NULL) {
1239                 /*
1240                  * If RFileName is non-null, it's the pathname of a
1241                  * savefile to read.  If VFileName is non-null, it's
1242                  * the pathname of a file containing a list of pathnames
1243                  * (one per line) of savefiles to read.
1244                  *
1245                  * In either case, we're reading a savefile, not doing
1246                  * a live capture.
1247                  */
1248 #ifndef WIN32
1249                 /*
1250                  * We don't need network access, so relinquish any set-UID
1251                  * or set-GID privileges we have (if any).
1252                  *
1253                  * We do *not* want set-UID privileges when opening a
1254                  * trace file, as that might let the user read other
1255                  * people's trace files (especially if we're set-UID
1256                  * root).
1257                  */
1258                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
1259                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1260 #endif /* WIN32 */
1261                 if (VFileName != NULL) {
1262                         if (VFileName[0] == '-' && VFileName[1] == '\0')
1263                                 VFile = stdin;
1264                         else
1265                                 VFile = fopen(VFileName, "r");
1266
1267                         if (VFile == NULL)
1268                                 error("Unable to open file: %s\n", strerror(errno));
1269
1270                         ret = get_next_file(VFile, VFileLine);
1271                         if (!ret)
1272                                 error("Nothing in %s\n", VFileName);
1273                         RFileName = VFileLine;
1274                 }
1275
1276                 pd = pcap_open_offline(RFileName, ebuf);
1277                 if (pd == NULL)
1278                         error("%s", ebuf);
1279 #ifdef __FreeBSD__
1280                 cap_rights_init(&rights, CAP_READ);
1281                 if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
1282                     errno != ENOSYS) {
1283                         error("unable to limit pcap descriptor");
1284                 }
1285 #endif
1286                 dlt = pcap_datalink(pd);
1287                 dlt_name = pcap_datalink_val_to_name(dlt);
1288                 if (dlt_name == NULL) {
1289                         fprintf(stderr, "reading from file %s, link-type %u\n",
1290                             RFileName, dlt);
1291                 } else {
1292                         fprintf(stderr,
1293                             "reading from file %s, link-type %s (%s)\n",
1294                             RFileName, dlt_name,
1295                             pcap_datalink_val_to_description(dlt));
1296                 }
1297                 localnet = 0;
1298                 netmask = 0;
1299         } else {
1300                 /*
1301                  * We're doing a live capture.
1302                  */
1303                 if (device == NULL) {
1304                         device = pcap_lookupdev(ebuf);
1305                         if (device == NULL)
1306                                 error("%s", ebuf);
1307                 }
1308 #ifdef WIN32
1309                 /*
1310                  * Print a message to the standard error on Windows.
1311                  * XXX - why do it here, with a different message?
1312                  */
1313                 if(strlen(device) == 1) //we assume that an ASCII string is always longer than 1 char
1314                 {                                               //a Unicode string has a \0 as second byte (so strlen() is 1)
1315                         fprintf(stderr, "%s: listening on %ws\n", program_name, device);
1316                 }
1317                 else
1318                 {
1319                         fprintf(stderr, "%s: listening on %s\n", program_name, device);
1320                 }
1321
1322                 fflush(stderr);
1323 #endif /* WIN32 */
1324 #ifdef HAVE_PCAP_CREATE
1325                 pd = pcap_create(device, ebuf);
1326                 if (pd == NULL)
1327                         error("%s", ebuf);
1328 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1329                 if (Jflag)
1330                         show_tstamp_types_and_exit(device, pd);
1331 #endif
1332                 /*
1333                  * Is this an interface that supports monitor mode?
1334                  */
1335                 if (pcap_can_set_rfmon(pd) == 1)
1336                         supports_monitor_mode = 1;
1337                 else
1338                         supports_monitor_mode = 0;
1339                 status = pcap_set_snaplen(pd, snaplen);
1340                 if (status != 0)
1341                         error("%s: Can't set snapshot length: %s",
1342                             device, pcap_statustostr(status));
1343                 status = pcap_set_promisc(pd, !pflag);
1344                 if (status != 0)
1345                         error("%s: Can't set promiscuous mode: %s",
1346                             device, pcap_statustostr(status));
1347                 if (Iflag) {
1348                         status = pcap_set_rfmon(pd, 1);
1349                         if (status != 0)
1350                                 error("%s: Can't set monitor mode: %s",
1351                                     device, pcap_statustostr(status));
1352                 }
1353                 status = pcap_set_timeout(pd, 1000);
1354                 if (status != 0)
1355                         error("%s: pcap_set_timeout failed: %s",
1356                             device, pcap_statustostr(status));
1357                 if (Bflag != 0) {
1358                         status = pcap_set_buffer_size(pd, Bflag);
1359                         if (status != 0)
1360                                 error("%s: Can't set buffer size: %s",
1361                                     device, pcap_statustostr(status));
1362                 }
1363 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1364                 if (jflag != -1) {
1365                         status = pcap_set_tstamp_type(pd, jflag);
1366                         if (status < 0)
1367                                 error("%s: Can't set time stamp type: %s",
1368                                     device, pcap_statustostr(status));
1369                 }
1370 #endif
1371                 status = pcap_activate(pd);
1372                 if (status < 0) {
1373                         /*
1374                          * pcap_activate() failed.
1375                          */
1376                         cp = pcap_geterr(pd);
1377                         if (status == PCAP_ERROR)
1378                                 error("%s", cp);
1379                         else if ((status == PCAP_ERROR_NO_SUCH_DEVICE ||
1380                                   status == PCAP_ERROR_PERM_DENIED) &&
1381                                  *cp != '\0')
1382                                 error("%s: %s\n(%s)", device,
1383                                     pcap_statustostr(status), cp);
1384 #ifdef __FreeBSD__
1385                         else if (status == PCAP_ERROR_RFMON_NOTSUP &&
1386                             strncmp(device, "wlan", 4) == 0) {
1387                                 char parent[8], newdev[8];
1388                                 char sysctl[32];
1389                                 size_t s = sizeof(parent);
1390
1391                                 snprintf(sysctl, sizeof(sysctl),
1392                                     "net.wlan.%d.%%parent", atoi(device + 4));
1393                                 sysctlbyname(sysctl, parent, &s, NULL, 0);
1394                                 strlcpy(newdev, device, sizeof(newdev));
1395                                 /* Suggest a new wlan device. */
1396                                 newdev[strlen(newdev)-1]++;
1397                                 error("%s is not a monitor mode VAP\n"
1398                                     "To create a new monitor mode VAP use:\n"
1399                                     "  ifconfig %s create wlandev %s wlanmode "
1400                                     "monitor\nand use %s as the tcpdump "
1401                                     "interface", device, newdev, parent,
1402                                     newdev);
1403                         }
1404 #endif
1405                         else
1406                                 error("%s: %s", device,
1407                                     pcap_statustostr(status));
1408                 } else if (status > 0) {
1409                         /*
1410                          * pcap_activate() succeeded, but it's warning us
1411                          * of a problem it had.
1412                          */
1413                         cp = pcap_geterr(pd);
1414                         if (status == PCAP_WARNING)
1415                                 warning("%s", cp);
1416                         else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1417                                  *cp != '\0')
1418                                 warning("%s: %s\n(%s)", device,
1419                                     pcap_statustostr(status), cp);
1420                         else
1421                                 warning("%s: %s", device,
1422                                     pcap_statustostr(status));
1423                 }
1424 #else
1425                 *ebuf = '\0';
1426                 pd = pcap_open_live(device, snaplen, !pflag, 1000, ebuf);
1427                 if (pd == NULL)
1428                         error("%s", ebuf);
1429                 else if (*ebuf)
1430                         warning("%s", ebuf);
1431 #endif /* HAVE_PCAP_CREATE */
1432                 /*
1433                  * Let user own process after socket has been opened.
1434                  */
1435 #ifndef WIN32
1436                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
1437                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
1438 #endif /* WIN32 */
1439 #if !defined(HAVE_PCAP_CREATE) && defined(WIN32)
1440                 if(Bflag != 0)
1441                         if(pcap_setbuff(pd, Bflag)==-1){
1442                                 error("%s", pcap_geterr(pd));
1443                         }
1444 #endif /* !defined(HAVE_PCAP_CREATE) && defined(WIN32) */
1445                 if (Lflag)
1446                         show_dlts_and_exit(device, pd);
1447                 if (gndo->ndo_dlt >= 0) {
1448 #ifdef HAVE_PCAP_SET_DATALINK
1449                         if (pcap_set_datalink(pd, gndo->ndo_dlt) < 0)
1450                                 error("%s", pcap_geterr(pd));
1451 #else
1452                         /*
1453                          * We don't actually support changing the
1454                          * data link type, so we only let them
1455                          * set it to what it already is.
1456                          */
1457                         if (gndo->ndo_dlt != pcap_datalink(pd)) {
1458                                 error("%s is not one of the DLTs supported by this device\n",
1459                                       gndo->ndo_dltname);
1460                         }
1461 #endif
1462                         (void)fprintf(stderr, "%s: data link type %s\n",
1463                                       program_name, gndo->ndo_dltname);
1464                         (void)fflush(stderr);
1465                 }
1466                 i = pcap_snapshot(pd);
1467                 if (snaplen < i) {
1468                         warning("snaplen raised from %d to %d", snaplen, i);
1469                         snaplen = i;
1470                 }
1471                 if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
1472                         localnet = 0;
1473                         netmask = 0;
1474                         warning("%s", ebuf);
1475                 }
1476         }
1477         if (infile)
1478                 cmdbuf = read_infile(infile);
1479         else
1480                 cmdbuf = copy_argv(&argv[optind]);
1481
1482         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1483                 error("%s", pcap_geterr(pd));
1484         if (dflag) {
1485                 bpf_dump(&fcode, dflag);
1486                 pcap_close(pd);
1487                 free(cmdbuf);
1488                 exit(0);
1489         }
1490         init_addrtoname(localnet, netmask);
1491         init_checksum();
1492
1493 #ifndef WIN32
1494         (void)setsignal(SIGPIPE, cleanup);
1495         (void)setsignal(SIGTERM, cleanup);
1496         (void)setsignal(SIGINT, cleanup);
1497 #endif /* WIN32 */
1498 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1499         (void)setsignal(SIGCHLD, child_cleanup);
1500 #endif
1501         /* Cooperate with nohup(1) */
1502 #ifndef WIN32
1503         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
1504                 (void)setsignal(SIGHUP, oldhandler);
1505 #endif /* WIN32 */
1506
1507 #ifndef WIN32
1508         /*
1509          * If a user name was specified with "-Z", attempt to switch to
1510          * that user's UID.  This would probably be used with sudo,
1511          * to allow tcpdump to be run in a special restricted
1512          * account (if you just want to allow users to open capture
1513          * devices, and can't just give users that permission,
1514          * you'd make tcpdump set-UID or set-GID).
1515          *
1516          * Tcpdump doesn't necessarily write only to one savefile;
1517          * the general only way to allow a -Z instance to write to
1518          * savefiles as the user under whose UID it's run, rather
1519          * than as the user specified with -Z, would thus be to switch
1520          * to the original user ID before opening a capture file and
1521          * then switch back to the -Z user ID after opening the savefile.
1522          * Switching to the -Z user ID only after opening the first
1523          * savefile doesn't handle the general case.
1524          */
1525
1526 #ifdef HAVE_CAP_NG_H
1527         /* We are running as root and we will be writing to savefile */
1528         if ((getuid() == 0 || geteuid() == 0) && WFileName) {
1529                 if (username) {
1530                         /* Drop all capabilities from effective set */
1531                         capng_clear(CAPNG_EFFECTIVE);
1532                         /* Add capabilities we will need*/
1533                         capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_SETUID);
1534                         capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_SETGID);
1535                         capng_update(CAPNG_ADD, CAPNG_PERMITTED, CAP_DAC_OVERRIDE);
1536
1537                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_SETUID);
1538                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_SETGID);
1539                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
1540
1541                         capng_apply(CAPNG_SELECT_BOTH);
1542                 }
1543         }
1544 #endif /* HAVE_CAP_NG_H */
1545
1546         if (getuid() == 0 || geteuid() == 0) {
1547                 if (username || chroot_dir)
1548                         droproot(username, chroot_dir);
1549
1550         }
1551 #endif /* WIN32 */
1552
1553         if (pcap_setfilter(pd, &fcode) < 0)
1554                 error("%s", pcap_geterr(pd));
1555 #ifdef __FreeBSD__
1556         if (RFileName == NULL && VFileName == NULL) {
1557                 static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
1558
1559                 /*
1560                  * The various libpcap devices use a combination of
1561                  * read (bpf), ioctl (bpf, netmap), poll (netmap).
1562                  * Grant the relevant access rights, sorted by name.
1563                  */
1564                 cap_rights_init(&rights, CAP_EVENT, CAP_IOCTL, CAP_READ);
1565                 if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
1566                     errno != ENOSYS) {
1567                         error("unable to limit pcap descriptor");
1568                 }
1569                 if (cap_ioctls_limit(pcap_fileno(pd), cmds,
1570                     sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
1571                         error("unable to limit ioctls on pcap descriptor");
1572                 }
1573         }
1574 #endif
1575         if (WFileName) {
1576                 pcap_dumper_t *p;
1577                 /* Do not exceed the default PATH_MAX for files. */
1578                 dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
1579
1580                 if (dumpinfo.CurrentFileName == NULL)
1581                         error("malloc of dumpinfo.CurrentFileName");
1582
1583                 /* We do not need numbering for dumpfiles if Cflag isn't set. */
1584                 if (Cflag != 0)
1585                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
1586                 else
1587                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
1588
1589                 p = pcap_dump_open(pd, dumpinfo.CurrentFileName);
1590 #ifdef HAVE_CAP_NG_H
1591         /* Give up capabilities, clear Effective set */
1592         capng_clear(CAPNG_EFFECTIVE);
1593 #endif
1594                 if (p == NULL)
1595                         error("%s", pcap_geterr(pd));
1596 #ifdef __FreeBSD__
1597                 set_dumper_capsicum_rights(p);
1598 #endif
1599                 if (Cflag != 0 || Gflag != 0) {
1600 #ifdef __FreeBSD__
1601                         dumpinfo.WFileName = strdup(basename(WFileName));
1602                         dumpinfo.dirfd = open(dirname(WFileName),
1603                             O_DIRECTORY | O_RDONLY);
1604                         if (dumpinfo.dirfd < 0) {
1605                                 error("unable to open directory %s",
1606                                     dirname(WFileName));
1607                         }
1608                         cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
1609                             CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
1610                         if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
1611                             errno != ENOSYS) {
1612                                 error("unable to limit directory rights");
1613                         }
1614                         if (cap_fcntls_limit(fileno(pcap_dump_file(p)), CAP_FCNTL_GETFL) < 0 &&
1615                             errno != ENOSYS) {
1616                                 error("unable to limit dump descriptor fcntls");
1617                         }
1618 #else   /* !__FreeBSD__ */
1619                         dumpinfo.WFileName = WFileName;
1620 #endif
1621                         callback = dump_packet_and_trunc;
1622                         dumpinfo.pd = pd;
1623                         dumpinfo.p = p;
1624                         pcap_userdata = (u_char *)&dumpinfo;
1625                 } else {
1626                         callback = dump_packet;
1627                         pcap_userdata = (u_char *)p;
1628                 }
1629 #ifdef HAVE_PCAP_DUMP_FLUSH
1630                 if (Uflag)
1631                         pcap_dump_flush(p);
1632 #endif
1633         } else {
1634                 type = pcap_datalink(pd);
1635                 printinfo = get_print_info(type);
1636                 callback = print_packet;
1637                 pcap_userdata = (u_char *)&printinfo;
1638         }
1639
1640 #ifdef SIGNAL_REQ_INFO
1641         /*
1642          * We can't get statistics when reading from a file rather
1643          * than capturing from a device.
1644          */
1645         if (RFileName == NULL)
1646                 (void)setsignal(SIGNAL_REQ_INFO, requestinfo);
1647 #endif
1648
1649         if (vflag > 0 && WFileName) {
1650                 /*
1651                  * When capturing to a file, "-v" means tcpdump should,
1652                  * every 10 secodns, "v"erbosely report the number of
1653                  * packets captured.
1654                  */
1655 #ifdef USE_WIN32_MM_TIMER
1656                 /* call verbose_stats_dump() each 1000 +/-100msec */
1657                 timer_id = timeSetEvent(1000, 100, verbose_stats_dump, 0, TIME_PERIODIC);
1658                 setvbuf(stderr, NULL, _IONBF, 0);
1659 #elif defined(HAVE_ALARM)
1660                 (void)setsignal(SIGALRM, verbose_stats_dump);
1661                 alarm(1);
1662 #endif
1663         }
1664
1665 #ifndef WIN32
1666         if (RFileName == NULL) {
1667                 /*
1668                  * Live capture (if -V was specified, we set RFileName
1669                  * to a file from the -V file).  Print a message to
1670                  * the standard error on UN*X.
1671                  */
1672                 if (!vflag && !WFileName) {
1673                         (void)fprintf(stderr,
1674                             "%s: verbose output suppressed, use -v or -vv for full protocol decode\n",
1675                             program_name);
1676                 } else
1677                         (void)fprintf(stderr, "%s: ", program_name);
1678                 dlt = pcap_datalink(pd);
1679                 dlt_name = pcap_datalink_val_to_name(dlt);
1680                 if (dlt_name == NULL) {
1681                         (void)fprintf(stderr, "listening on %s, link-type %u, capture size %u bytes\n",
1682                             device, dlt, snaplen);
1683                 } else {
1684                         (void)fprintf(stderr, "listening on %s, link-type %s (%s), capture size %u bytes\n",
1685                             device, dlt_name,
1686                             pcap_datalink_val_to_description(dlt), snaplen);
1687                 }
1688                 (void)fflush(stderr);
1689         }
1690 #endif /* WIN32 */
1691
1692 #ifdef __FreeBSD__
1693         cansandbox = (nflag && VFileName == NULL && zflag == NULL);
1694         if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
1695                 error("unable to enter the capability mode");
1696 #endif  /* __FreeBSD__ */
1697
1698         do {
1699                 status = pcap_loop(pd, cnt, callback, pcap_userdata);
1700                 if (WFileName == NULL) {
1701                         /*
1702                          * We're printing packets.  Flush the printed output,
1703                          * so it doesn't get intermingled with error output.
1704                          */
1705                         if (status == -2) {
1706                                 /*
1707                                  * We got interrupted, so perhaps we didn't
1708                                  * manage to finish a line we were printing.
1709                                  * Print an extra newline, just in case.
1710                                  */
1711                                 putchar('\n');
1712                         }
1713                         (void)fflush(stdout);
1714                 }
1715                 if (status == -1) {
1716                         /*
1717                          * Error.  Report it.
1718                          */
1719                         (void)fprintf(stderr, "%s: pcap_loop: %s\n",
1720                             program_name, pcap_geterr(pd));
1721                 }
1722                 if (RFileName == NULL) {
1723                         /*
1724                          * We're doing a live capture.  Report the capture
1725                          * statistics.
1726                          */
1727                         info(1);
1728                 }
1729                 pcap_close(pd);
1730                 if (VFileName != NULL) {
1731                         ret = get_next_file(VFile, VFileLine);
1732                         if (ret) {
1733                                 RFileName = VFileLine;
1734                                 pd = pcap_open_offline(RFileName, ebuf);
1735                                 if (pd == NULL)
1736                                         error("%s", ebuf);
1737 #ifdef __FreeBSD__
1738                                 cap_rights_init(&rights, CAP_READ);
1739                                 if (cap_rights_limit(fileno(pcap_file(pd)),
1740                                     &rights) < 0 && errno != ENOSYS) {
1741                                         error("unable to limit pcap descriptor");
1742                                 }
1743 #endif
1744                                 new_dlt = pcap_datalink(pd);
1745                                 if (WFileName && new_dlt != dlt)
1746                                         error("%s: new dlt does not match original", RFileName);
1747                                 printinfo = get_print_info(new_dlt);
1748                                 dlt_name = pcap_datalink_val_to_name(new_dlt);
1749                                 if (dlt_name == NULL) {
1750                                         fprintf(stderr, "reading from file %s, link-type %u\n",
1751                                         RFileName, new_dlt);
1752                                 } else {
1753                                         fprintf(stderr,
1754                                         "reading from file %s, link-type %s (%s)\n",
1755                                         RFileName, dlt_name,
1756                                         pcap_datalink_val_to_description(new_dlt));
1757                                 }
1758                                 if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
1759                                         error("%s", pcap_geterr(pd));
1760                                 if (pcap_setfilter(pd, &fcode) < 0)
1761                                         error("%s", pcap_geterr(pd));
1762                         }
1763                 }
1764         }
1765         while (ret != NULL);
1766
1767         free(cmdbuf);
1768         exit(status == -1 ? 1 : 0);
1769 }
1770
1771 /* make a clean exit on interrupts */
1772 static RETSIGTYPE
1773 cleanup(int signo _U_)
1774 {
1775 #ifdef USE_WIN32_MM_TIMER
1776         if (timer_id)
1777                 timeKillEvent(timer_id);
1778         timer_id = 0;
1779 #elif defined(HAVE_ALARM)
1780         alarm(0);
1781 #endif
1782
1783 #ifdef HAVE_PCAP_BREAKLOOP
1784         /*
1785          * We have "pcap_breakloop()"; use it, so that we do as little
1786          * as possible in the signal handler (it's probably not safe
1787          * to do anything with standard I/O streams in a signal handler -
1788          * the ANSI C standard doesn't say it is).
1789          */
1790         pcap_breakloop(pd);
1791 #else
1792         /*
1793          * We don't have "pcap_breakloop()"; this isn't safe, but
1794          * it's the best we can do.  Print the summary if we're
1795          * not reading from a savefile - i.e., if we're doing a
1796          * live capture - and exit.
1797          */
1798         if (pd != NULL && pcap_file(pd) == NULL) {
1799                 /*
1800                  * We got interrupted, so perhaps we didn't
1801                  * manage to finish a line we were printing.
1802                  * Print an extra newline, just in case.
1803                  */
1804                 putchar('\n');
1805                 (void)fflush(stdout);
1806                 info(1);
1807         }
1808         exit(0);
1809 #endif
1810 }
1811
1812 /*
1813   On windows, we do not use a fork, so we do not care less about
1814   waiting a child processes to die
1815  */
1816 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1817 static RETSIGTYPE
1818 child_cleanup(int signo _U_)
1819 {
1820   wait(NULL);
1821 }
1822 #endif /* HAVE_FORK && HAVE_VFORK */
1823
1824 static void
1825 info(register int verbose)
1826 {
1827         struct pcap_stat stat;
1828
1829         /*
1830          * Older versions of libpcap didn't set ps_ifdrop on some
1831          * platforms; initialize it to 0 to handle that.
1832          */
1833         stat.ps_ifdrop = 0;
1834         if (pcap_stats(pd, &stat) < 0) {
1835                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
1836                 infoprint = 0;
1837                 return;
1838         }
1839
1840         if (!verbose)
1841                 fprintf(stderr, "%s: ", program_name);
1842
1843         (void)fprintf(stderr, "%u packet%s captured", packets_captured,
1844             PLURAL_SUFFIX(packets_captured));
1845         if (!verbose)
1846                 fputs(", ", stderr);
1847         else
1848                 putc('\n', stderr);
1849         (void)fprintf(stderr, "%u packet%s received by filter", stat.ps_recv,
1850             PLURAL_SUFFIX(stat.ps_recv));
1851         if (!verbose)
1852                 fputs(", ", stderr);
1853         else
1854                 putc('\n', stderr);
1855         (void)fprintf(stderr, "%u packet%s dropped by kernel", stat.ps_drop,
1856             PLURAL_SUFFIX(stat.ps_drop));
1857         if (stat.ps_ifdrop != 0) {
1858                 if (!verbose)
1859                         fputs(", ", stderr);
1860                 else
1861                         putc('\n', stderr);
1862                 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
1863                     stat.ps_ifdrop, PLURAL_SUFFIX(stat.ps_ifdrop));
1864         } else
1865                 putc('\n', stderr);
1866         infoprint = 0;
1867 }
1868
1869 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
1870 static void
1871 compress_savefile(const char *filename)
1872 {
1873 # ifdef HAVE_FORK
1874         if (fork())
1875 # else
1876         if (vfork())
1877 # endif
1878                 return;
1879         /*
1880          * Set to lowest priority so that this doesn't disturb the capture
1881          */
1882 #ifdef NZERO
1883         setpriority(PRIO_PROCESS, 0, NZERO - 1);
1884 #else
1885         setpriority(PRIO_PROCESS, 0, 19);
1886 #endif
1887         if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
1888                 fprintf(stderr,
1889                         "compress_savefile:execlp(%s, %s): %s\n",
1890                         zflag,
1891                         filename,
1892                         strerror(errno));
1893 # ifdef HAVE_FORK
1894         exit(1);
1895 # else
1896         _exit(1);
1897 # endif
1898 }
1899 #else  /* HAVE_FORK && HAVE_VFORK */
1900 static void
1901 compress_savefile(const char *filename)
1902 {
1903         fprintf(stderr,
1904                 "compress_savefile failed. Functionality not implemented under your system\n");
1905 }
1906 #endif /* HAVE_FORK && HAVE_VFORK */
1907
1908 static void
1909 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
1910 {
1911         struct dump_info *dump_info;
1912
1913         ++packets_captured;
1914
1915         ++infodelay;
1916
1917         dump_info = (struct dump_info *)user;
1918
1919         /*
1920          * XXX - this won't force the file to rotate on the specified time
1921          * boundary, but it will rotate on the first packet received after the
1922          * specified Gflag number of seconds. Note: if a Gflag time boundary
1923          * and a Cflag size boundary coincide, the time rotation will occur
1924          * first thereby cancelling the Cflag boundary (since the file should
1925          * be 0).
1926          */
1927         if (Gflag != 0) {
1928                 /* Check if it is time to rotate */
1929                 time_t t;
1930
1931                 /* Get the current time */
1932                 if ((t = time(NULL)) == (time_t)-1) {
1933                         error("dump_and_trunc_packet: can't get current_time: %s",
1934                             pcap_strerror(errno));
1935                 }
1936
1937
1938                 /* If the time is greater than the specified window, rotate */
1939                 if (t - Gflag_time >= Gflag) {
1940 #ifdef __FreeBSD__
1941                         FILE *fp;
1942                         int fd;
1943 #endif
1944
1945                         /* Update the Gflag_time */
1946                         Gflag_time = t;
1947                         /* Update Gflag_count */
1948                         Gflag_count++;
1949                         /*
1950                          * Close the current file and open a new one.
1951                          */
1952                         pcap_dump_close(dump_info->p);
1953
1954                         /*
1955                          * Compress the file we just closed, if the user asked for it
1956                          */
1957                         if (zflag != NULL)
1958                                 compress_savefile(dump_info->CurrentFileName);
1959
1960                         /*
1961                          * Check to see if we've exceeded the Wflag (when
1962                          * not using Cflag).
1963                          */
1964                         if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
1965                                 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
1966                                     Wflag);
1967                                 exit(0);
1968                                 /* NOTREACHED */
1969                         }
1970                         if (dump_info->CurrentFileName != NULL)
1971                                 free(dump_info->CurrentFileName);
1972                         /* Allocate space for max filename + \0. */
1973                         dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
1974                         if (dump_info->CurrentFileName == NULL)
1975                                 error("dump_packet_and_trunc: malloc");
1976                         /*
1977                          * This is always the first file in the Cflag
1978                          * rotation: e.g. 0
1979                          * We also don't need numbering if Cflag is not set.
1980                          */
1981                         if (Cflag != 0)
1982                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
1983                                     WflagChars);
1984                         else
1985                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
1986
1987 #ifdef HAVE_CAP_NG_H
1988                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
1989                         capng_apply(CAPNG_EFFECTIVE);
1990 #endif /* HAVE_CAP_NG_H */
1991 #ifdef __FreeBSD__
1992                         fd = openat(dump_info->dirfd,
1993                             dump_info->CurrentFileName,
1994                             O_CREAT | O_WRONLY | O_TRUNC, 0644);
1995                         if (fd < 0) {
1996                                 error("unable to open file %s",
1997                                     dump_info->CurrentFileName);
1998                         }
1999                         fp = fdopen(fd, "w");
2000                         if (fp == NULL) {
2001                                 error("unable to fdopen file %s",
2002                                     dump_info->CurrentFileName);
2003                         }
2004                         dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2005 #else   /* !__FreeBSD__ */
2006                         dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2007 #endif
2008 #ifdef HAVE_CAP_NG_H
2009                         capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2010                         capng_apply(CAPNG_EFFECTIVE);
2011 #endif /* HAVE_CAP_NG_H */
2012                         if (dump_info->p == NULL)
2013                                 error("%s", pcap_geterr(pd));
2014 #ifdef __FreeBSD__
2015                         set_dumper_capsicum_rights(dump_info->p);
2016 #endif
2017                 }
2018         }
2019
2020         /*
2021          * XXX - this won't prevent capture files from getting
2022          * larger than Cflag - the last packet written to the
2023          * file could put it over Cflag.
2024          */
2025         if (Cflag != 0 && pcap_dump_ftell(dump_info->p) > Cflag) {
2026 #ifdef __FreeBSD__
2027                 FILE *fp;
2028                 int fd;
2029 #endif
2030
2031                 /*
2032                  * Close the current file and open a new one.
2033                  */
2034                 pcap_dump_close(dump_info->p);
2035
2036                 /*
2037                  * Compress the file we just closed, if the user asked for it
2038                  */
2039                 if (zflag != NULL)
2040                         compress_savefile(dump_info->CurrentFileName);
2041
2042                 Cflag_count++;
2043                 if (Wflag > 0) {
2044                         if (Cflag_count >= Wflag)
2045                                 Cflag_count = 0;
2046                 }
2047                 if (dump_info->CurrentFileName != NULL)
2048                         free(dump_info->CurrentFileName);
2049                 dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2050                 if (dump_info->CurrentFileName == NULL)
2051                         error("dump_packet_and_trunc: malloc");
2052                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
2053 #ifdef __FreeBSD__
2054                 fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
2055                     O_CREAT | O_WRONLY | O_TRUNC, 0644);
2056                 if (fd < 0) {
2057                         error("unable to open file %s",
2058                             dump_info->CurrentFileName);
2059                 }
2060                 fp = fdopen(fd, "w");
2061                 if (fp == NULL) {
2062                         error("unable to fdopen file %s",
2063                             dump_info->CurrentFileName);
2064                 }
2065                 dump_info->p = pcap_dump_fopen(dump_info->pd, fp);
2066 #else   /* !__FreeBSD__ */
2067                 dump_info->p = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2068 #endif
2069                 if (dump_info->p == NULL)
2070                         error("%s", pcap_geterr(pd));
2071 #ifdef __FreeBSD__
2072                 set_dumper_capsicum_rights(dump_info->p);
2073 #endif
2074         }
2075
2076         pcap_dump((u_char *)dump_info->p, h, sp);
2077 #ifdef HAVE_PCAP_DUMP_FLUSH
2078         if (Uflag)
2079                 pcap_dump_flush(dump_info->p);
2080 #endif
2081
2082         --infodelay;
2083         if (infoprint)
2084                 info(0);
2085 }
2086
2087 static void
2088 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2089 {
2090         ++packets_captured;
2091
2092         ++infodelay;
2093
2094         pcap_dump(user, h, sp);
2095 #ifdef HAVE_PCAP_DUMP_FLUSH
2096         if (Uflag)
2097                 pcap_dump_flush((pcap_dumper_t *)user);
2098 #endif
2099
2100         --infodelay;
2101         if (infoprint)
2102                 info(0);
2103 }
2104
2105 static void
2106 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2107 {
2108         struct print_info *print_info;
2109         u_int hdrlen;
2110
2111         ++packets_captured;
2112
2113         ++infodelay;
2114         ts_print(&h->ts);
2115
2116         print_info = (struct print_info *)user;
2117
2118         /*
2119          * Some printers want to check that they're not walking off the
2120          * end of the packet.
2121          * Rather than pass it all the way down, we set this global.
2122          */
2123         snapend = sp + h->caplen;
2124
2125         if(print_info->ndo_type) {
2126                 hdrlen = (*print_info->p.ndo_printer)(print_info->ndo, h, sp);
2127         } else {
2128                 hdrlen = (*print_info->p.printer)(h, sp);
2129         }
2130
2131         if (Xflag) {
2132                 /*
2133                  * Print the raw packet data in hex and ASCII.
2134                  */
2135                 if (Xflag > 1) {
2136                         /*
2137                          * Include the link-layer header.
2138                          */
2139                         hex_and_ascii_print("\n\t", sp, h->caplen);
2140                 } else {
2141                         /*
2142                          * Don't include the link-layer header - and if
2143                          * we have nothing past the link-layer header,
2144                          * print nothing.
2145                          */
2146                         if (h->caplen > hdrlen)
2147                                 hex_and_ascii_print("\n\t", sp + hdrlen,
2148                                     h->caplen - hdrlen);
2149                 }
2150         } else if (xflag) {
2151                 /*
2152                  * Print the raw packet data in hex.
2153                  */
2154                 if (xflag > 1) {
2155                         /*
2156                          * Include the link-layer header.
2157                          */
2158                         hex_print("\n\t", sp, h->caplen);
2159                 } else {
2160                         /*
2161                          * Don't include the link-layer header - and if
2162                          * we have nothing past the link-layer header,
2163                          * print nothing.
2164                          */
2165                         if (h->caplen > hdrlen)
2166                                 hex_print("\n\t", sp + hdrlen,
2167                                     h->caplen - hdrlen);
2168                 }
2169         } else if (Aflag) {
2170                 /*
2171                  * Print the raw packet data in ASCII.
2172                  */
2173                 if (Aflag > 1) {
2174                         /*
2175                          * Include the link-layer header.
2176                          */
2177                         ascii_print(sp, h->caplen);
2178                 } else {
2179                         /*
2180                          * Don't include the link-layer header - and if
2181                          * we have nothing past the link-layer header,
2182                          * print nothing.
2183                          */
2184                         if (h->caplen > hdrlen)
2185                                 ascii_print(sp + hdrlen, h->caplen - hdrlen);
2186                 }
2187         }
2188
2189         putchar('\n');
2190
2191         --infodelay;
2192         if (infoprint)
2193                 info(0);
2194 }
2195
2196 #ifdef WIN32
2197         /*
2198          * XXX - there should really be libpcap calls to get the version
2199          * number as a string (the string would be generated from #defines
2200          * at run time, so that it's not generated from string constants
2201          * in the library, as, on many UNIX systems, those constants would
2202          * be statically linked into the application executable image, and
2203          * would thus reflect the version of libpcap on the system on
2204          * which the application was *linked*, not the system on which it's
2205          * *running*.
2206          *
2207          * That routine should be documented, unlike the "version[]"
2208          * string, so that UNIX vendors providing their own libpcaps
2209          * don't omit it (as a couple of vendors have...).
2210          *
2211          * Packet.dll should perhaps also export a routine to return the
2212          * version number of the Packet.dll code, to supply the
2213          * "Wpcap_version" information on Windows.
2214          */
2215         char WDversion[]="current-cvs.tcpdump.org";
2216 #if !defined(HAVE_GENERATED_VERSION)
2217         char version[]="current-cvs.tcpdump.org";
2218 #endif
2219         char pcap_version[]="current-cvs.tcpdump.org";
2220         char Wpcap_version[]="3.1";
2221 #endif
2222
2223 /*
2224  * By default, print the specified data out in hex and ASCII.
2225  */
2226 static void
2227 ndo_default_print(netdissect_options *ndo _U_, const u_char *bp, u_int length)
2228 {
2229         hex_and_ascii_print("\n\t", bp, length); /* pass on lf and identation string */
2230 }
2231
2232 void
2233 default_print(const u_char *bp, u_int length)
2234 {
2235         ndo_default_print(gndo, bp, length);
2236 }
2237
2238 #ifdef SIGNAL_REQ_INFO
2239 RETSIGTYPE requestinfo(int signo _U_)
2240 {
2241         if (infodelay)
2242                 ++infoprint;
2243         else
2244                 info(0);
2245 }
2246 #endif
2247
2248 /*
2249  * Called once each second in verbose mode while dumping to file
2250  */
2251 #ifdef USE_WIN32_MM_TIMER
2252 void CALLBACK verbose_stats_dump (UINT timer_id _U_, UINT msg _U_, DWORD_PTR arg _U_,
2253                                   DWORD_PTR dw1 _U_, DWORD_PTR dw2 _U_)
2254 {
2255         struct pcap_stat stat;
2256
2257         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2258                 fprintf(stderr, "Got %u\r", packets_captured);
2259 }
2260 #elif defined(HAVE_ALARM)
2261 static void verbose_stats_dump(int sig _U_)
2262 {
2263         struct pcap_stat stat;
2264
2265         if (infodelay == 0 && pcap_stats(pd, &stat) >= 0)
2266                 fprintf(stderr, "Got %u\r", packets_captured);
2267         alarm(1);
2268 }
2269 #endif
2270
2271 static void
2272 usage(void)
2273 {
2274         extern char version[];
2275 #ifndef HAVE_PCAP_LIB_VERSION
2276 #if defined(WIN32) || defined(HAVE_PCAP_VERSION)
2277         extern char pcap_version[];
2278 #else /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2279         static char pcap_version[] = "unknown";
2280 #endif /* defined(WIN32) || defined(HAVE_PCAP_VERSION) */
2281 #endif /* HAVE_PCAP_LIB_VERSION */
2282
2283 #ifdef HAVE_PCAP_LIB_VERSION
2284 #ifdef WIN32
2285         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2286 #else /* WIN32 */
2287         (void)fprintf(stderr, "%s version %s\n", program_name, version);
2288 #endif /* WIN32 */
2289         (void)fprintf(stderr, "%s\n",pcap_lib_version());
2290 #else /* HAVE_PCAP_LIB_VERSION */
2291 #ifdef WIN32
2292         (void)fprintf(stderr, "%s version %s, based on tcpdump version %s\n", program_name, WDversion, version);
2293         (void)fprintf(stderr, "WinPcap version %s, based on libpcap version %s\n",Wpcap_version, pcap_version);
2294 #else /* WIN32 */
2295         (void)fprintf(stderr, "%s version %s\n", program_name, version);
2296         (void)fprintf(stderr, "libpcap version %s\n", pcap_version);
2297 #endif /* WIN32 */
2298 #endif /* HAVE_PCAP_LIB_VERSION */
2299         (void)fprintf(stderr,
2300 "Usage: %s [-aAbd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqRStu" U_FLAG "vxX]" B_FLAG_USAGE " [ -c count ]\n", program_name);
2301         (void)fprintf(stderr,
2302 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
2303         (void)fprintf(stderr,
2304 "\t\t[ -i interface ]" j_FLAG_USAGE " [ -M secret ]\n");
2305         (void)fprintf(stderr,
2306 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ -V file ] [ -w file ]\n");
2307         (void)fprintf(stderr,
2308 "\t\t[ -W filecount ] [ -y datalinktype ] [ -z command ]\n");
2309         (void)fprintf(stderr,
2310 "\t\t[ -Z user ] [ expression ]\n");
2311         exit(1);
2312 }
2313
2314
2315
2316 /* VARARGS */
2317 static void
2318 ndo_error(netdissect_options *ndo _U_, const char *fmt, ...)
2319 {
2320         va_list ap;
2321
2322         (void)fprintf(stderr, "%s: ", program_name);
2323         va_start(ap, fmt);
2324         (void)vfprintf(stderr, fmt, ap);
2325         va_end(ap);
2326         if (*fmt) {
2327                 fmt += strlen(fmt);
2328                 if (fmt[-1] != '\n')
2329                         (void)fputc('\n', stderr);
2330         }
2331         exit(1);
2332         /* NOTREACHED */
2333 }
2334
2335 /* VARARGS */
2336 static void
2337 ndo_warning(netdissect_options *ndo _U_, const char *fmt, ...)
2338 {
2339         va_list ap;
2340
2341         (void)fprintf(stderr, "%s: WARNING: ", program_name);
2342         va_start(ap, fmt);
2343         (void)vfprintf(stderr, fmt, ap);
2344         va_end(ap);
2345         if (*fmt) {
2346                 fmt += strlen(fmt);
2347                 if (fmt[-1] != '\n')
2348                         (void)fputc('\n', stderr);
2349         }
2350 }