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 /*
  29  * tcpdump - dump traffic on a network
  30  *
  31  * First written in 1987 by Van Jacobson, Lawrence Berkeley Laboratory.
  32  * Mercilessly hacked and occasionally improved since then via the
  33  * combined efforts of Van, Steve McCanne and Craig Leres of LBL.
  34  */
  35
  36 #ifdef HAVE_CONFIG_H
  37 #include <config.h>
  38 #endif
  39
  40 /*
  41  * Some older versions of Mac OS X may ship pcap.h from libpcap 0.6 with a
  42  * libpcap based on 0.8.  That means it has pcap_findalldevs() but the
  43  * header doesn't define pcap_if_t, meaning that we can't actually *use*
  44  * pcap_findalldevs().
  45  */
  46 #ifdef HAVE_PCAP_FINDALLDEVS
  47 #ifndef HAVE_PCAP_IF_T
  48 #undef HAVE_PCAP_FINDALLDEVS
  49 #endif
  50 #endif
  51
  52 #include "netdissect-stdinc.h"
  53
  54 /*
  55  * This must appear after including netdissect-stdinc.h, so that _U_ is
  56  * defined.
  57  */
  58 #ifndef lint
  59 static const char copyright[] _U_ =
  60     "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\
  61 The Regents of the University of California.  All rights reserved.\n";
  62 #endif
  63
  64 #include <sys/stat.h>
  65
  66 #ifdef HAVE_FCNTL_H
  67 #include <fcntl.h>
  68 #endif
  69
  70 #ifdef HAVE_LIBCRYPTO
  71 #include <openssl/crypto.h>
  72 #endif
  73
  74 #ifdef HAVE_GETOPT_LONG
  75 #include <getopt.h>
  76 #else
  77 #include "missing/getopt_long.h"
  78 #endif
  79 /* Capsicum-specific code requires macros from <net/bpf.h>, which will fail
  80  * to compile if <pcap.h> has already been included; including the headers
  81  * in the opposite order works fine. For the most part anyway, because in
  82  * FreeBSD <pcap/pcap.h> declares bpf_dump() instead of <net/bpf.h>. Thus
  83  * interface.h takes care of it later to avoid a compiler warning.
  84  */
  85 #ifdef HAVE_CAPSICUM
  86 #include <sys/capsicum.h>
  87 #include <sys/ioccom.h>
  88 #include <net/bpf.h>
  89 #include <libgen.h>
  90 #ifdef HAVE_CASPER
  91 #include <libcasper.h>
  92 #include <casper/cap_dns.h>
  93 #include <sys/nv.h>
  94 #endif  /* HAVE_CASPER */
  95 #endif  /* HAVE_CAPSICUM */
  96 #ifdef HAVE_PCAP_OPEN
  97 /*
  98  * We found pcap_open() in the capture library, so we'll be using
  99  * the remote capture APIs; define PCAP_REMOTE before we include pcap.h,
 100  * so we get those APIs declared, and the types and #defines that they
 101  * use defined.
 102  *
 103  * WinPcap's headers require that PCAP_REMOTE be defined in order to get
 104  * remote-capture APIs declared and types and #defines that they use
 105  * defined.
 106  *
 107  * (Versions of libpcap with those APIs, and thus Npcap, which is based on
 108  * those versions of libpcap, don't require it.)
 109  */
 110 #define HAVE_REMOTE
 111 #endif
 112 #include <pcap.h>
 113 #include <signal.h>
 114 #include <stdio.h>
 115 #include <stdarg.h>
 116 #include <stdlib.h>
 117 #include <string.h>
 118 #include <limits.h>
 119 #ifdef _WIN32
 120 #include <windows.h>
 121 #else
 122 #include <sys/time.h>
 123 #include <sys/wait.h>
 124 #include <sys/resource.h>
 125 #include <pwd.h>
 126 #include <grp.h>
 127 #endif /* _WIN32 */
 128
 129 /*
 130  * Pathname separator.
 131  * Use this in pathnames, but do *not* use it in URLs.
 132  */
 133 #ifdef _WIN32
 134 #define PATH_SEPARATOR  '\\'
 135 #else
 136 #define PATH_SEPARATOR  '/'
 137 #endif
 138
 139 /* capabilities convenience library */
 140 /* If a code depends on HAVE_LIBCAP_NG, it depends also on HAVE_CAP_NG_H.
 141  * If HAVE_CAP_NG_H is not defined, undefine HAVE_LIBCAP_NG.
 142  * Thus, the later tests are done only on HAVE_LIBCAP_NG.
 143  */
 144 #ifdef HAVE_LIBCAP_NG
 145 #ifdef HAVE_CAP_NG_H
 146 #include <cap-ng.h>
 147 #else
 148 #undef HAVE_LIBCAP_NG
 149 #endif /* HAVE_CAP_NG_H */
 150 #endif /* HAVE_LIBCAP_NG */
 151
 152 #ifdef __FreeBSD__
 153 #include <sys/sysctl.h>
 154 #endif /* __FreeBSD__ */
 155
 156 #include "netdissect-stdinc.h"
 157 #include "netdissect.h"
 158 #include "interface.h"
 159 #include "addrtoname.h"
 160 #include "machdep.h"
 161 #include "pcap-missing.h"
 162 #include "ascii_strcasecmp.h"
 163
 164 #include "print.h"
 165
 166 #include "diag-control.h"
 167
 168 #include "fptype.h"
 169
 170 #ifndef PATH_MAX
 171 #define PATH_MAX 1024
 172 #endif
 173
 174 #if defined(SIGINFO)
 175 #define SIGNAL_REQ_INFO SIGINFO
 176 #elif defined(SIGUSR1)
 177 #define SIGNAL_REQ_INFO SIGUSR1
 178 #endif
 179
 180 #if defined(HAVE_PCAP_DUMP_FLUSH) && defined(SIGUSR2)
 181 #define SIGNAL_FLUSH_PCAP SIGUSR2
 182 #endif
 183
 184 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
 185 static int Bflag;                       /* buffer size */
 186 #endif
 187 #ifdef HAVE_PCAP_DUMP_FTELL64
 188 static int64_t Cflag;                   /* rotate dump files after this many bytes */
 189 #else
 190 static long Cflag;                      /* rotate dump files after this many bytes */
 191 #endif
 192 static int Cflag_count;                 /* Keep track of which file number we're writing */
 193 #ifdef HAVE_PCAP_FINDALLDEVS
 194 static int Dflag;                       /* list available devices and exit */
 195 #endif
 196 #ifdef HAVE_PCAP_FINDALLDEVS_EX
 197 static char *remote_interfaces_source;  /* list available devices from this source and exit */
 198 #endif
 199
 200 /*
 201  * This is exported because, in some versions of libpcap, if libpcap
 202  * is built with optimizer debugging code (which is *NOT* the default
 203  * configuration!), the library *imports*(!) a variable named dflag,
 204  * under the expectation that tcpdump is exporting it, to govern
 205  * how much debugging information to print when optimizing
 206  * the generated BPF code.
 207  *
 208  * This is a horrible hack; newer versions of libpcap don't import
 209  * dflag but, instead, *if* built with optimizer debugging code,
 210  * *export* a routine to set that flag.
 211  */
 212 extern int dflag;
 213 int dflag;                              /* print filter code */
 214 static int Gflag;                       /* rotate dump files after this many seconds */
 215 static int Gflag_count;                 /* number of files created with Gflag rotation */
 216 static time_t Gflag_time;               /* The last time_t the dump file was rotated. */
 217 static int Lflag;                       /* list available data link types and exit */
 218 static int Iflag;                       /* rfmon (monitor) mode */
 219 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 220 static int Jflag;                       /* list available time stamp types */
 221 static int jflag = -1;                  /* packet time stamp source */
 222 #endif
 223 static int lflag;                       /* line-buffered output */
 224 static int pflag;                       /* don't go promiscuous */
 225 #ifdef HAVE_PCAP_SETDIRECTION
 226 static int Qflag = -1;                  /* restrict captured packet by send/receive direction */
 227 #endif
 228 #ifdef HAVE_PCAP_DUMP_FLUSH
 229 static int Uflag;                       /* "unbuffered" output of dump files */
 230 #endif
 231 static int Wflag;                       /* recycle output files after this number of files */
 232 static int WflagChars;
 233 static char *zflag = NULL;              /* compress each savefile using a specified command (like gzip or bzip2) */
 234 static int timeout = 1000;              /* default timeout = 1000 ms = 1 s */
 235 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
 236 static int immediate_mode;
 237 #endif
 238 static int count_mode;
 239
 240 static int infodelay;
 241 static int infoprint;
 242
 243 char *program_name;
 244
 245 /*
 246  * #ifdef HAVE_CASPER
 247  * cap_channel_t *capdns;
 248  * #endif
 249  */
 250
 251 /* Forwards */
 252 static NORETURN void error(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
 253 static void warning(FORMAT_STRING(const char *), ...) PRINTFLIKE(1, 2);
 254 static NORETURN void exit_tcpdump(int);
 255 static void (*setsignal (int sig, void (*func)(int)))(int);
 256 static void cleanup(int);
 257 static void child_cleanup(int);
 258 static void print_version(FILE *);
 259 static void print_usage(FILE *);
 260 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 261 static NORETURN void show_tstamp_types_and_exit(pcap_t *, const char *device);
 262 #endif
 263 static NORETURN void show_dlts_and_exit(pcap_t *, const char *device);
 264 #ifdef HAVE_PCAP_FINDALLDEVS
 265 static NORETURN void show_devices_and_exit(void);
 266 #endif
 267 #ifdef HAVE_PCAP_FINDALLDEVS_EX
 268 static NORETURN void show_remote_devices_and_exit(void);
 269 #endif
 270
 271 static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 272 static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *);
 273 static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *);
 274 static void droproot(const char *, const char *);
 275
 276 #ifdef SIGNAL_REQ_INFO
 277 static void requestinfo(int);
 278 #endif
 279
 280 #ifdef SIGNAL_FLUSH_PCAP
 281 static void flushpcap(int);
 282 #endif
 283
 284 #ifdef _WIN32
 285     static HANDLE timer_handle = INVALID_HANDLE_VALUE;
 286     static void CALLBACK verbose_stats_dump(PVOID param, BOOLEAN timer_fired);
 287 #else /* _WIN32 */
 288   static void verbose_stats_dump(int sig);
 289 #endif /* _WIN32 */
 290
 291 static void info(int);
 292 static u_int packets_captured;
 293
 294 #ifdef HAVE_PCAP_FINDALLDEVS
 295 static const struct tok status_flags[] = {
 296 #ifdef PCAP_IF_UP
 297         { PCAP_IF_UP,       "Up"       },
 298 #endif
 299 #ifdef PCAP_IF_RUNNING
 300         { PCAP_IF_RUNNING,  "Running"  },
 301 #endif
 302         { PCAP_IF_LOOPBACK, "Loopback" },
 303 #ifdef PCAP_IF_WIRELESS
 304         { PCAP_IF_WIRELESS, "Wireless" },
 305 #endif
 306         { 0, NULL }
 307 };
 308 #endif
 309
 310 static pcap_t *pd;
 311 static pcap_dumper_t *pdd = NULL;
 312
 313 static int supports_monitor_mode;
 314
 315 extern int optind;
 316 extern int opterr;
 317 extern char *optarg;
 318
 319 struct dump_info {
 320         char    *WFileName;
 321         char    *CurrentFileName;
 322         pcap_t  *pd;
 323         pcap_dumper_t *pdd;
 324         netdissect_options *ndo;
 325 #ifdef HAVE_CAPSICUM
 326         int     dirfd;
 327 #endif
 328 };
 329
 330 #if defined(HAVE_PCAP_SET_PARSER_DEBUG)
 331 /*
 332  * We have pcap_set_parser_debug() in libpcap; declare it (it's not declared
 333  * by any libpcap header, because it's a special hack, only available if
 334  * libpcap was configured to include it, and only intended for use by
 335  * libpcap developers trying to debug the parser for filter expressions).
 336  */
 337 #ifdef _WIN32
 338 __declspec(dllimport)
 339 #else /* _WIN32 */
 340 extern
 341 #endif /* _WIN32 */
 342 void pcap_set_parser_debug(int);
 343 #elif defined(HAVE_PCAP_DEBUG) || defined(HAVE_YYDEBUG)
 344 /*
 345  * We don't have pcap_set_parser_debug() in libpcap, but we do have
 346  * pcap_debug or yydebug.  Make a local version of pcap_set_parser_debug()
 347  * to set the flag, and define HAVE_PCAP_SET_PARSER_DEBUG.
 348  */
 349 static void
 350 pcap_set_parser_debug(int value)
 351 {
 352 #ifdef HAVE_PCAP_DEBUG
 353         extern int pcap_debug;
 354
 355         pcap_debug = value;
 356 #else /* HAVE_PCAP_DEBUG */
 357         extern int yydebug;
 358
 359         yydebug = value;
 360 #endif /* HAVE_PCAP_DEBUG */
 361 }
 362
 363 #define HAVE_PCAP_SET_PARSER_DEBUG
 364 #endif
 365
 366 #if defined(HAVE_PCAP_SET_OPTIMIZER_DEBUG)
 367 /*
 368  * We have pcap_set_optimizer_debug() in libpcap; declare it (it's not declared
 369  * by any libpcap header, because it's a special hack, only available if
 370  * libpcap was configured to include it, and only intended for use by
 371  * libpcap developers trying to debug the optimizer for filter expressions).
 372  */
 373 #ifdef _WIN32
 374 __declspec(dllimport)
 375 #else /* _WIN32 */
 376 extern
 377 #endif /* _WIN32 */
 378 void pcap_set_optimizer_debug(int);
 379 #endif
 380
 381 /* VARARGS */
 382 static void
 383 error(const char *fmt, ...)
 384 {
 385         va_list ap;
 386
 387         (void)fprintf(stderr, "%s: ", program_name);
 388         va_start(ap, fmt);
 389         (void)vfprintf(stderr, fmt, ap);
 390         va_end(ap);
 391         if (*fmt) {
 392                 fmt += strlen(fmt);
 393                 if (fmt[-1] != '\n')
 394                         (void)fputc('\n', stderr);
 395         }
 396         exit_tcpdump(S_ERR_HOST_PROGRAM);
 397         /* NOTREACHED */
 398 }
 399
 400 /* VARARGS */
 401 static void
 402 warning(const char *fmt, ...)
 403 {
 404         va_list ap;
 405
 406         (void)fprintf(stderr, "%s: WARNING: ", program_name);
 407         va_start(ap, fmt);
 408         (void)vfprintf(stderr, fmt, ap);
 409         va_end(ap);
 410         if (*fmt) {
 411                 fmt += strlen(fmt);
 412                 if (fmt[-1] != '\n')
 413                         (void)fputc('\n', stderr);
 414         }
 415 }
 416
 417 static void
 418 exit_tcpdump(int status)
 419 {
 420         nd_cleanup();
 421         exit(status);
 422 }
 423
 424 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 425 static void
 426 show_tstamp_types_and_exit(pcap_t *pc, const char *device)
 427 {
 428         int n_tstamp_types;
 429         int *tstamp_types = 0;
 430         const char *tstamp_type_name;
 431         int i;
 432
 433         n_tstamp_types = pcap_list_tstamp_types(pc, &tstamp_types);
 434         if (n_tstamp_types < 0)
 435                 error("%s", pcap_geterr(pc));
 436
 437         if (n_tstamp_types == 0) {
 438                 fprintf(stderr, "Time stamp type cannot be set for %s\n",
 439                     device);
 440                 exit_tcpdump(S_SUCCESS);
 441         }
 442         fprintf(stderr, "Time stamp types for %s (use option -j to set):\n",
 443             device);
 444         for (i = 0; i < n_tstamp_types; i++) {
 445                 tstamp_type_name = pcap_tstamp_type_val_to_name(tstamp_types[i]);
 446                 if (tstamp_type_name != NULL) {
 447                         (void) fprintf(stderr, "  %s (%s)\n", tstamp_type_name,
 448                             pcap_tstamp_type_val_to_description(tstamp_types[i]));
 449                 } else {
 450                         (void) fprintf(stderr, "  %d\n", tstamp_types[i]);
 451                 }
 452         }
 453         pcap_free_tstamp_types(tstamp_types);
 454         exit_tcpdump(S_SUCCESS);
 455 }
 456 #endif
 457
 458 static void
 459 show_dlts_and_exit(pcap_t *pc, const char *device)
 460 {
 461         int n_dlts, i;
 462         int *dlts = 0;
 463         const char *dlt_name;
 464
 465         n_dlts = pcap_list_datalinks(pc, &dlts);
 466         if (n_dlts < 0)
 467                 error("%s", pcap_geterr(pc));
 468         else if (n_dlts == 0 || !dlts)
 469                 error("No data link types.");
 470
 471         /*
 472          * If the interface is known to support monitor mode, indicate
 473          * whether these are the data link types available when not in
 474          * monitor mode, if -I wasn't specified, or when in monitor mode,
 475          * when -I was specified (the link-layer types available in
 476          * monitor mode might be different from the ones available when
 477          * not in monitor mode).
 478          */
 479         if (supports_monitor_mode)
 480                 (void) fprintf(stderr, "Data link types for %s %s (use option -y to set):\n",
 481                     device,
 482                     Iflag ? "when in monitor mode" : "when not in monitor mode");
 483         else
 484                 (void) fprintf(stderr, "Data link types for %s (use option -y to set):\n",
 485                     device);
 486
 487         for (i = 0; i < n_dlts; i++) {
 488                 dlt_name = pcap_datalink_val_to_name(dlts[i]);
 489                 if (dlt_name != NULL) {
 490                         (void) fprintf(stderr, "  %s (%s)", dlt_name,
 491                             pcap_datalink_val_to_description(dlts[i]));
 492
 493                         /*
 494                          * OK, does tcpdump handle that type?
 495                          */
 496                         if (!has_printer(dlts[i]))
 497                                 (void) fprintf(stderr, " (printing not supported)");
 498                         fprintf(stderr, "\n");
 499                 } else {
 500                         (void) fprintf(stderr, "  DLT %d (printing not supported)\n",
 501                             dlts[i]);
 502                 }
 503         }
 504 #ifdef HAVE_PCAP_FREE_DATALINKS
 505         pcap_free_datalinks(dlts);
 506 #endif
 507         exit_tcpdump(S_SUCCESS);
 508 }
 509
 510 #ifdef HAVE_PCAP_FINDALLDEVS
 511 static void
 512 show_devices_and_exit(void)
 513 {
 514         pcap_if_t *dev, *devlist;
 515         char ebuf[PCAP_ERRBUF_SIZE];
 516         int i;
 517
 518         if (pcap_findalldevs(&devlist, ebuf) < 0)
 519                 error("%s", ebuf);
 520         for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
 521                 printf("%d.%s", i+1, dev->name);
 522                 if (dev->description != NULL)
 523                         printf(" (%s)", dev->description);
 524                 if (dev->flags != 0) {
 525                         printf(" [");
 526                         printf("%s", bittok2str(status_flags, "none", dev->flags));
 527 #ifdef PCAP_IF_WIRELESS
 528                         if (dev->flags & PCAP_IF_WIRELESS) {
 529                                 switch (dev->flags & PCAP_IF_CONNECTION_STATUS) {
 530
 531                                 case PCAP_IF_CONNECTION_STATUS_UNKNOWN:
 532                                         printf(", Association status unknown");
 533                                         break;
 534
 535                                 case PCAP_IF_CONNECTION_STATUS_CONNECTED:
 536                                         printf(", Associated");
 537                                         break;
 538
 539                                 case PCAP_IF_CONNECTION_STATUS_DISCONNECTED:
 540                                         printf(", Not associated");
 541                                         break;
 542
 543                                 case PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE:
 544                                         break;
 545                                 }
 546                         } else {
 547                                 switch (dev->flags & PCAP_IF_CONNECTION_STATUS) {
 548
 549                                 case PCAP_IF_CONNECTION_STATUS_UNKNOWN:
 550                                         printf(", Connection status unknown");
 551                                         break;
 552
 553                                 case PCAP_IF_CONNECTION_STATUS_CONNECTED:
 554                                         printf(", Connected");
 555                                         break;
 556
 557                                 case PCAP_IF_CONNECTION_STATUS_DISCONNECTED:
 558                                         printf(", Disconnected");
 559                                         break;
 560
 561                                 case PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE:
 562                                         break;
 563                                 }
 564                         }
 565 #endif
 566                         printf("]");
 567                 }
 568                 printf("\n");
 569         }
 570         pcap_freealldevs(devlist);
 571         exit_tcpdump(S_SUCCESS);
 572 }
 573 #endif /* HAVE_PCAP_FINDALLDEVS */
 574
 575 #ifdef HAVE_PCAP_FINDALLDEVS_EX
 576 static void
 577 show_remote_devices_and_exit(void)
 578 {
 579         pcap_if_t *dev, *devlist;
 580         char ebuf[PCAP_ERRBUF_SIZE];
 581         int i;
 582
 583         if (pcap_findalldevs_ex(remote_interfaces_source, NULL, &devlist,
 584             ebuf) < 0)
 585                 error("%s", ebuf);
 586         for (i = 0, dev = devlist; dev != NULL; i++, dev = dev->next) {
 587                 printf("%d.%s", i+1, dev->name);
 588                 if (dev->description != NULL)
 589                         printf(" (%s)", dev->description);
 590                 if (dev->flags != 0)
 591                         printf(" [%s]", bittok2str(status_flags, "none", dev->flags));
 592                 printf("\n");
 593         }
 594         pcap_freealldevs(devlist);
 595         exit_tcpdump(S_SUCCESS);
 596 }
 597 #endif /* HAVE_PCAP_FINDALLDEVS */
 598
 599 /*
 600  * Short options.
 601  *
 602  * Note that there we use all letters for short options except for g, k,
 603  * o, and P, and those are used by other versions of tcpdump, and we should
 604  * only use them for the same purposes that the other versions of tcpdump
 605  * use them:
 606  *
 607  * macOS tcpdump uses -g to force non--v output for IP to be on one
 608  * line, making it more "g"repable;
 609  *
 610  * macOS tcpdump uses -k to specify that packet comments in pcapng files
 611  * should be printed;
 612  *
 613  * OpenBSD tcpdump uses -o to indicate that OS fingerprinting should be done
 614  * for hosts sending TCP SYN packets;
 615  *
 616  * macOS tcpdump uses -P to indicate that -w should write pcapng rather
 617  * than pcap files.
 618  *
 619  * macOS tcpdump also uses -Q to specify expressions that match packet
 620  * metadata, including but not limited to the packet direction.
 621  * The expression syntax is different from a simple "in|out|inout",
 622  * and those expressions aren't accepted by macOS tcpdump, but the
 623  * equivalents would be "in" = "dir=in", "out" = "dir=out", and
 624  * "inout" = "dir=in or dir=out", and the parser could conceivably
 625  * special-case "in", "out", and "inout" as expressions for backwards
 626  * compatibility, so all is not (yet) lost.
 627  */
 628
 629 /*
 630  * Set up flags that might or might not be supported depending on the
 631  * version of libpcap we're using.
 632  */
 633 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
 634 #define B_FLAG          "B:"
 635 #define B_FLAG_USAGE    " [ -B size ]"
 636 #else /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
 637 #define B_FLAG
 638 #define B_FLAG_USAGE
 639 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
 640
 641 #ifdef HAVE_PCAP_FINDALLDEVS
 642 #define D_FLAG  "D"
 643 #else
 644 #define D_FLAG
 645 #endif
 646
 647 #ifdef HAVE_PCAP_CREATE
 648 #define I_FLAG          "I"
 649 #else /* HAVE_PCAP_CREATE */
 650 #define I_FLAG
 651 #endif /* HAVE_PCAP_CREATE */
 652
 653 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 654 #define j_FLAG          "j:"
 655 #define j_FLAG_USAGE    " [ -j tstamptype ]"
 656 #define J_FLAG          "J"
 657 #else /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 658 #define j_FLAG
 659 #define j_FLAG_USAGE
 660 #define J_FLAG
 661 #endif /* PCAP_ERROR_TSTAMP_TYPE_NOTSUP */
 662
 663 #ifdef USE_LIBSMI
 664 #define m_FLAG_USAGE "[ -m module ] ..."
 665 #endif
 666
 667 #ifdef HAVE_PCAP_SETDIRECTION
 668 #define Q_FLAG "Q:"
 669 #define Q_FLAG_USAGE " [ -Q in|out|inout ]"
 670 #else
 671 #define Q_FLAG
 672 #define Q_FLAG_USAGE
 673 #endif
 674
 675 #ifdef HAVE_PCAP_DUMP_FLUSH
 676 #define U_FLAG  "U"
 677 #else
 678 #define U_FLAG
 679 #endif
 680
 681 #define SHORTOPTS "aAb" B_FLAG "c:C:d" D_FLAG "eE:fF:G:hHi:" I_FLAG j_FLAG J_FLAG "KlLm:M:nNOpq" Q_FLAG "r:s:StT:u" U_FLAG "vV:w:W:xXy:Yz:Z:#"
 682
 683 /*
 684  * Long options.
 685  *
 686  * We do not currently have long options corresponding to all short
 687  * options; we should probably pick appropriate option names for them.
 688  *
 689  * However, the short options where the number of times the option is
 690  * specified matters, such as -v and -d and -t, should probably not
 691  * just map to a long option, as saying
 692  *
 693  *  tcpdump --verbose --verbose
 694  *
 695  * doesn't make sense; it should be --verbosity={N} or something such
 696  * as that.
 697  *
 698  * For long options with no corresponding short options, we define values
 699  * outside the range of ASCII graphic characters, make that the last
 700  * component of the entry for the long option, and have a case for that
 701  * option in the switch statement.
 702  */
 703 #define OPTION_VERSION                  128
 704 #define OPTION_TSTAMP_PRECISION         129
 705 #define OPTION_IMMEDIATE_MODE           130
 706 #define OPTION_PRINT                    131
 707 #define OPTION_LIST_REMOTE_INTERFACES   132
 708 #define OPTION_TSTAMP_MICRO             133
 709 #define OPTION_TSTAMP_NANO              134
 710 #define OPTION_FP_TYPE                  135
 711 #define OPTION_COUNT                    136
 712
 713 static const struct option longopts[] = {
 714 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
 715         { "buffer-size", required_argument, NULL, 'B' },
 716 #endif
 717         { "list-interfaces", no_argument, NULL, 'D' },
 718 #ifdef HAVE_PCAP_FINDALLDEVS_EX
 719         { "list-remote-interfaces", required_argument, NULL, OPTION_LIST_REMOTE_INTERFACES },
 720 #endif
 721         { "help", no_argument, NULL, 'h' },
 722         { "interface", required_argument, NULL, 'i' },
 723 #ifdef HAVE_PCAP_CREATE
 724         { "monitor-mode", no_argument, NULL, 'I' },
 725 #endif
 726 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
 727         { "time-stamp-type", required_argument, NULL, 'j' },
 728         { "list-time-stamp-types", no_argument, NULL, 'J' },
 729 #endif
 730 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
 731         { "micro", no_argument, NULL, OPTION_TSTAMP_MICRO},
 732         { "nano", no_argument, NULL, OPTION_TSTAMP_NANO},
 733         { "time-stamp-precision", required_argument, NULL, OPTION_TSTAMP_PRECISION},
 734 #endif
 735         { "dont-verify-checksums", no_argument, NULL, 'K' },
 736         { "list-data-link-types", no_argument, NULL, 'L' },
 737         { "no-optimize", no_argument, NULL, 'O' },
 738         { "no-promiscuous-mode", no_argument, NULL, 'p' },
 739 #ifdef HAVE_PCAP_SETDIRECTION
 740         { "direction", required_argument, NULL, 'Q' },
 741 #endif
 742         { "snapshot-length", required_argument, NULL, 's' },
 743         { "absolute-tcp-sequence-numbers", no_argument, NULL, 'S' },
 744 #ifdef HAVE_PCAP_DUMP_FLUSH
 745         { "packet-buffered", no_argument, NULL, 'U' },
 746 #endif
 747         { "linktype", required_argument, NULL, 'y' },
 748 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
 749         { "immediate-mode", no_argument, NULL, OPTION_IMMEDIATE_MODE },
 750 #endif
 751 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
 752         { "debug-filter-parser", no_argument, NULL, 'Y' },
 753 #endif
 754         { "relinquish-privileges", required_argument, NULL, 'Z' },
 755         { "count", no_argument, NULL, OPTION_COUNT },
 756         { "fp-type", no_argument, NULL, OPTION_FP_TYPE },
 757         { "number", no_argument, NULL, '#' },
 758         { "print", no_argument, NULL, OPTION_PRINT },
 759         { "version", no_argument, NULL, OPTION_VERSION },
 760         { NULL, 0, NULL, 0 }
 761 };
 762
 763 #ifdef HAVE_PCAP_FINDALLDEVS_EX
 764 #define LIST_REMOTE_INTERFACES_USAGE "[ --list-remote-interfaces remote-source ]"
 765 #else
 766 #define LIST_REMOTE_INTERFACES_USAGE
 767 #endif
 768
 769 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
 770 #define IMMEDIATE_MODE_USAGE " [ --immediate-mode ]"
 771 #else
 772 #define IMMEDIATE_MODE_USAGE ""
 773 #endif
 774
 775 #ifndef _WIN32
 776 /* Drop root privileges and chroot if necessary */
 777 static void
 778 droproot(const char *username, const char *chroot_dir)
 779 {
 780         struct passwd *pw = NULL;
 781
 782         if (chroot_dir && !username)
 783                 error("Chroot without dropping root is insecure");
 784
 785         pw = getpwnam(username);
 786         if (pw) {
 787                 if (chroot_dir) {
 788                         if (chroot(chroot_dir) != 0 || chdir ("/") != 0)
 789                                 error("Couldn't chroot/chdir to '%.64s': %s",
 790                                       chroot_dir, pcap_strerror(errno));
 791                 }
 792 #ifdef HAVE_LIBCAP_NG
 793                 {
 794                         int ret = capng_change_id(pw->pw_uid, pw->pw_gid, CAPNG_NO_FLAG);
 795                         if (ret < 0)
 796                                 error("capng_change_id(): return %d\n", ret);
 797                         else
 798                                 fprintf(stderr, "dropped privs to %s\n", username);
 799                 }
 800 #else
 801                 if (initgroups(pw->pw_name, pw->pw_gid) != 0 ||
 802                     setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0)
 803                         error("Couldn't change to '%.32s' uid=%lu gid=%lu: %s",
 804                                 username,
 805                                 (unsigned long)pw->pw_uid,
 806                                 (unsigned long)pw->pw_gid,
 807                                 pcap_strerror(errno));
 808                 else {
 809                         fprintf(stderr, "dropped privs to %s\n", username);
 810                 }
 811 #endif /* HAVE_LIBCAP_NG */
 812         } else
 813                 error("Couldn't find user '%.32s'", username);
 814 #ifdef HAVE_LIBCAP_NG
 815         /* We don't need CAP_SETUID, CAP_SETGID and CAP_SYS_CHROOT any more. */
 816 DIAG_OFF_ASSIGN_ENUM
 817         capng_updatev(
 818                 CAPNG_DROP,
 819                 CAPNG_EFFECTIVE | CAPNG_PERMITTED,
 820                 CAP_SETUID,
 821                 CAP_SETGID,
 822                 CAP_SYS_CHROOT,
 823                 -1);
 824 DIAG_ON_ASSIGN_ENUM
 825         capng_apply(CAPNG_SELECT_BOTH);
 826 #endif /* HAVE_LIBCAP_NG */
 827
 828 }
 829 #endif /* _WIN32 */
 830
 831 static int
 832 getWflagChars(int x)
 833 {
 834         int c = 0;
 835
 836         x -= 1;
 837         while (x > 0) {
 838                 c += 1;
 839                 x /= 10;
 840         }
 841
 842         return c;
 843 }
 844
 845
 846 static void
 847 MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars)
 848 {
 849         char *filename = malloc(PATH_MAX + 1);
 850         if (filename == NULL)
 851             error("%s: malloc", __func__);
 852         if (strlen(orig_name) == 0)
 853             error("an empty string is not a valid file name");
 854
 855         /* Process with strftime if Gflag is set. */
 856         if (Gflag != 0) {
 857           struct tm *local_tm;
 858
 859           /* Convert Gflag_time to a usable format */
 860           if ((local_tm = localtime(&Gflag_time)) == NULL) {
 861                   error("%s: localtime", __func__);
 862           }
 863
 864           /* There's no good way to detect an error in strftime since a return
 865            * value of 0 isn't necessarily failure; if orig_name is an empty
 866            * string, the formatted string will be empty.
 867            *
 868            * However, the C90 standard says that, if there *is* a
 869            * buffer overflow, the content of the buffer is undefined,
 870            * so we must check for a buffer overflow.
 871            *
 872            * So we check above for an empty orig_name, and only call
 873            * strftime() if it's non-empty, in which case the return
 874            * value will only be 0 if the formatted date doesn't fit
 875            * in the buffer.
 876            *
 877            * (We check above because, even if we don't use -G, we
 878            * want a better error message than "tcpdump: : No such
 879            * file or directory" for this case.)
 880            */
 881           if (strftime(filename, PATH_MAX, orig_name, local_tm) == 0) {
 882             error("%s: strftime", __func__);
 883           }
 884         } else {
 885           strncpy(filename, orig_name, PATH_MAX);
 886         }
 887
 888         if (cnt == 0 && max_chars == 0)
 889                 strncpy(buffer, filename, PATH_MAX + 1);
 890         else
 891                 if (snprintf(buffer, PATH_MAX + 1, "%s%0*d", filename, max_chars, cnt) > PATH_MAX)
 892                   /* Report an error if the filename is too large */
 893                   error("too many output files or filename is too long (> %d)", PATH_MAX);
 894         free(filename);
 895 }
 896
 897 static char *
 898 get_next_file(FILE *VFile, char *ptr)
 899 {
 900         char *ret;
 901         size_t len;
 902
 903         ret = fgets(ptr, PATH_MAX, VFile);
 904         if (!ret)
 905                 return NULL;
 906
 907         len = strlen (ptr);
 908         if (len > 0 && ptr[len - 1] == '\n')
 909                 ptr[len - 1] = '\0';
 910
 911         return ret;
 912 }
 913
 914 #ifdef HAVE_CASPER
 915 static cap_channel_t *
 916 capdns_setup(void)
 917 {
 918         cap_channel_t *capcas, *capdnsloc;
 919         const char *types[1];
 920         int families[2];
 921
 922         capcas = cap_init();
 923         if (capcas == NULL)
 924                 error("unable to create casper process");
 925         capdnsloc = cap_service_open(capcas, "system.dns");
 926         /* Casper capability no longer needed. */
 927         cap_close(capcas);
 928         if (capdnsloc == NULL)
 929                 error("unable to open system.dns service");
 930         /* Limit system.dns to reverse DNS lookups. */
 931         types[0] = "ADDR2NAME";
 932         if (cap_dns_type_limit(capdnsloc, types, 1) < 0)
 933                 error("unable to limit access to system.dns service");
 934         families[0] = AF_INET;
 935         families[1] = AF_INET6;
 936         if (cap_dns_family_limit(capdnsloc, families, 2) < 0)
 937                 error("unable to limit access to system.dns service");
 938
 939         return (capdnsloc);
 940 }
 941 #endif  /* HAVE_CASPER */
 942
 943 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
 944 static int
 945 tstamp_precision_from_string(const char *precision)
 946 {
 947         if (strncmp(precision, "nano", strlen("nano")) == 0)
 948                 return PCAP_TSTAMP_PRECISION_NANO;
 949
 950         if (strncmp(precision, "micro", strlen("micro")) == 0)
 951                 return PCAP_TSTAMP_PRECISION_MICRO;
 952
 953         return -EINVAL;
 954 }
 955
 956 static const char *
 957 tstamp_precision_to_string(int precision)
 958 {
 959         switch (precision) {
 960
 961         case PCAP_TSTAMP_PRECISION_MICRO:
 962                 return "micro";
 963
 964         case PCAP_TSTAMP_PRECISION_NANO:
 965                 return "nano";
 966
 967         default:
 968                 return "unknown";
 969         }
 970 }
 971 #endif
 972
 973 #ifdef HAVE_CAPSICUM
 974 /*
 975  * Ensure that, on a dump file's descriptor, we have all the rights
 976  * necessary to make the standard I/O library work with an fdopen()ed
 977  * FILE * from that descriptor.
 978  *
 979  * A long time ago in a galaxy far, far away, AT&T decided that, instead
 980  * of providing separate APIs for getting and setting the FD_ flags on a
 981  * descriptor, getting and setting the O_ flags on a descriptor, and
 982  * locking files, they'd throw them all into a kitchen-sink fcntl() call
 983  * along the lines of ioctl(), the fact that ioctl() operations are
 984  * largely specific to particular character devices but fcntl() operations
 985  * are either generic to all descriptors or generic to all descriptors for
 986  * regular files nonwithstanding.
 987  *
 988  * The Capsicum people decided that fine-grained control of descriptor
 989  * operations was required, so that you need to grant permission for
 990  * reading, writing, seeking, and fcntl-ing.  The latter, courtesy of
 991  * AT&T's decision, means that "fcntl-ing" isn't a thing, but a motley
 992  * collection of things, so there are *individual* fcntls for which
 993  * permission needs to be granted.
 994  *
 995  * The FreeBSD standard I/O people implemented some optimizations that
 996  * requires that the standard I/O routines be able to determine whether
 997  * the descriptor for the FILE * is open append-only or not; as that
 998  * descriptor could have come from an open() rather than an fopen(),
 999  * that requires that it be able to do an F_GETFL fcntl() to read
1000  * the O_ flags.
1001  *
1002  * Tcpdump uses ftell() to determine how much data has been written
1003  * to a file in order to, when used with -C, determine when it's time
1004  * to rotate capture files.  ftell() therefore needs to do an lseek()
1005  * to find out the file offset and must, thanks to the aforementioned
1006  * optimization, also know whether the descriptor is open append-only
1007  * or not.
1008  *
1009  * The net result of all the above is that we need to grant CAP_SEEK,
1010  * CAP_WRITE, and CAP_FCNTL with the CAP_FCNTL_GETFL subcapability.
1011  *
1012  * Perhaps this is the universe's way of saying that either
1013  *
1014  *      1) there needs to be an fopenat() call and a pcap_dump_openat() call
1015  *         using it, so that Capsicum-capable tcpdump wouldn't need to do
1016  *         an fdopen()
1017  *
1018  * or
1019  *
1020  *      2) there needs to be a cap_fdopen() call in the FreeBSD standard
1021  *         I/O library that knows what rights are needed by the standard
1022  *         I/O library, based on the open mode, and assigns them, perhaps
1023  *         with an additional argument indicating, for example, whether
1024  *         seeking should be allowed, so that tcpdump doesn't need to know
1025  *         what the standard I/O library happens to require this week.
1026  */
1027 static void
1028 set_dumper_capsicum_rights(pcap_dumper_t *p)
1029 {
1030         int fd = fileno(pcap_dump_file(p));
1031         cap_rights_t rights;
1032
1033         cap_rights_init(&rights, CAP_SEEK, CAP_WRITE, CAP_FCNTL);
1034         if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
1035                 error("unable to limit dump descriptor");
1036         }
1037         if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS) {
1038                 error("unable to limit dump descriptor fcntls");
1039         }
1040 }
1041 #endif
1042
1043 /*
1044  * Copy arg vector into a new buffer, concatenating arguments with spaces.
1045  */
1046 static char *
1047 copy_argv(char **argv)
1048 {
1049         char **p;
1050         size_t len = 0;
1051         char *buf;
1052         char *src, *dst;
1053
1054         p = argv;
1055         if (*p == NULL)
1056                 return 0;
1057
1058         while (*p)
1059                 len += strlen(*p++) + 1;
1060
1061         buf = (char *)malloc(len);
1062         if (buf == NULL)
1063                 error("%s: malloc", __func__);
1064
1065         p = argv;
1066         dst = buf;
1067         while ((src = *p++) != NULL) {
1068                 while ((*dst++ = *src++) != '\0')
1069                         ;
1070                 dst[-1] = ' ';
1071         }
1072         dst[-1] = '\0';
1073
1074         return buf;
1075 }
1076
1077 /*
1078  * On Windows, we need to open the file in binary mode, so that
1079  * we get all the bytes specified by the size we get from "fstat()".
1080  * On UNIX, that's not necessary.  O_BINARY is defined on Windows;
1081  * we define it as 0 if it's not defined, so it does nothing.
1082  */
1083 #ifndef O_BINARY
1084 #define O_BINARY        0
1085 #endif
1086
1087 static char *
1088 read_infile(char *fname)
1089 {
1090         int i, fd;
1091         ssize_t cc;
1092         char *cp;
1093         our_statb buf;
1094
1095         fd = open(fname, O_RDONLY|O_BINARY);
1096         if (fd < 0)
1097                 error("can't open %s: %s", fname, pcap_strerror(errno));
1098
1099         if (our_fstat(fd, &buf) < 0)
1100                 error("can't stat %s: %s", fname, pcap_strerror(errno));
1101
1102         /*
1103          * Reject files whose size doesn't fit into an int; a filter
1104          * *that* large will probably be too big.
1105          */
1106         if (buf.st_size > INT_MAX)
1107                 error("%s is too large", fname);
1108
1109         cp = malloc((u_int)buf.st_size + 1);
1110         if (cp == NULL)
1111                 error("malloc(%d) for %s: %s", (u_int)buf.st_size + 1,
1112                         fname, pcap_strerror(errno));
1113         cc = read(fd, cp, (u_int)buf.st_size);
1114         if (cc < 0)
1115                 error("read %s: %s", fname, pcap_strerror(errno));
1116         if (cc != buf.st_size)
1117                 error("short read %s (%d != %d)", fname, (int) cc,
1118                     (int)buf.st_size);
1119
1120         close(fd);
1121         /* replace "# comment" with spaces */
1122         for (i = 0; i < cc; i++) {
1123                 if (cp[i] == '#')
1124                         while (i < cc && cp[i] != '\n')
1125                                 cp[i++] = ' ';
1126         }
1127         cp[cc] = '\0';
1128         return (cp);
1129 }
1130
1131 #ifdef HAVE_PCAP_FINDALLDEVS
1132 static long
1133 parse_interface_number(const char *device)
1134 {
1135         const char *p;
1136         long devnum;
1137         char *end;
1138
1139         /*
1140          * Search for a colon, terminating any scheme at the beginning
1141          * of the device.
1142          */
1143         p = strchr(device, ':');
1144         if (p != NULL) {
1145                 /*
1146                  * We found it.  Is it followed by "//"?
1147                  */
1148                 p++;    /* skip the : */
1149                 if (strncmp(p, "//", 2) == 0) {
1150                         /*
1151                          * Yes.  Search for the next /, at the end of the
1152                          * authority part of the URL.
1153                          */
1154                         p += 2; /* skip the // */
1155                         p = strchr(p, '/');
1156                         if (p != NULL) {
1157                                 /*
1158                                  * OK, past the / is the path.
1159                                  */
1160                                 device = p + 1;
1161                         }
1162                 }
1163         }
1164         devnum = strtol(device, &end, 10);
1165         if (device != end && *end == '\0') {
1166                 /*
1167                  * It's all-numeric, but is it a valid number?
1168                  */
1169                 if (devnum <= 0) {
1170                         /*
1171                          * No, it's not an ordinal.
1172                          */
1173                         error("Invalid adapter index");
1174                 }
1175                 return (devnum);
1176         } else {
1177                 /*
1178                  * It's not all-numeric; return -1, so our caller
1179                  * knows that.
1180                  */
1181                 return (-1);
1182         }
1183 }
1184
1185 static char *
1186 find_interface_by_number(const char *url
1187 #ifndef HAVE_PCAP_FINDALLDEVS_EX
1188 _U_
1189 #endif
1190 , long devnum)
1191 {
1192         pcap_if_t *dev, *devlist;
1193         long i;
1194         char ebuf[PCAP_ERRBUF_SIZE];
1195         char *device;
1196 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1197         const char *endp;
1198         char *host_url;
1199 #endif
1200         int status;
1201
1202 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1203         /*
1204          * Search for a colon, terminating any scheme at the beginning
1205          * of the URL.
1206          */
1207         endp = strchr(url, ':');
1208         if (endp != NULL) {
1209                 /*
1210                  * We found it.  Is it followed by "//"?
1211                  */
1212                 endp++; /* skip the : */
1213                 if (strncmp(endp, "//", 2) == 0) {
1214                         /*
1215                          * Yes.  Search for the next /, at the end of the
1216                          * authority part of the URL.
1217                          */
1218                         endp += 2;      /* skip the // */
1219                         endp = strchr(endp, '/');
1220                 } else
1221                         endp = NULL;
1222         }
1223         if (endp != NULL) {
1224                 /*
1225                  * OK, everything from device to endp is a URL to hand
1226                  * to pcap_findalldevs_ex().
1227                  */
1228                 endp++; /* Include the trailing / in the URL; pcap_findalldevs_ex() requires it */
1229                 host_url = malloc(endp - url + 1);
1230                 if (host_url == NULL && (endp - url + 1) > 0)
1231                         error("Invalid allocation for host");
1232
1233                 memcpy(host_url, url, endp - url);
1234                 host_url[endp - url] = '\0';
1235                 status = pcap_findalldevs_ex(host_url, NULL, &devlist, ebuf);
1236                 free(host_url);
1237         } else
1238 #endif
1239         status = pcap_findalldevs(&devlist, ebuf);
1240         if (status < 0)
1241                 error("%s", ebuf);
1242         /*
1243          * Look for the devnum-th entry in the list of devices (1-based).
1244          */
1245         for (i = 0, dev = devlist; i < devnum-1 && dev != NULL;
1246             i++, dev = dev->next)
1247                 ;
1248         if (dev == NULL)
1249                 error("Invalid adapter index");
1250         device = strdup(dev->name);
1251         pcap_freealldevs(devlist);
1252         return (device);
1253 }
1254 #endif
1255
1256 #ifdef HAVE_PCAP_OPEN
1257 /*
1258  * Prefixes for rpcap URLs.
1259  */
1260 static char rpcap_prefix[] = "rpcap://";
1261 static char rpcap_ssl_prefix[] = "rpcaps://";
1262 #endif
1263
1264 static pcap_t *
1265 open_interface(const char *device, netdissect_options *ndo, char *ebuf)
1266 {
1267         pcap_t *pc;
1268 #ifdef HAVE_PCAP_CREATE
1269         int status;
1270         char *cp;
1271 #endif
1272
1273 #ifdef HAVE_PCAP_OPEN
1274         /*
1275          * Is this an rpcap URL?
1276          */
1277         if (strncmp(device, rpcap_prefix, sizeof(rpcap_prefix) - 1) == 0 ||
1278             strncmp(device, rpcap_ssl_prefix, sizeof(rpcap_ssl_prefix) - 1) == 0) {
1279                 /*
1280                  * Yes.  Open it with pcap_open().
1281                  */
1282                 *ebuf = '\0';
1283                 pc = pcap_open(device, ndo->ndo_snaplen,
1284                     pflag ? 0 : PCAP_OPENFLAG_PROMISCUOUS, timeout, NULL,
1285                     ebuf);
1286                 if (pc == NULL) {
1287                         /*
1288                          * If this failed with "No such device" or "The system
1289                          * cannot find the device specified", that means
1290                          * the interface doesn't exist; return NULL, so that
1291                          * the caller can see whether the device name is
1292                          * actually an interface index.
1293                          */
1294                         if (strstr(ebuf, "No such device") != NULL ||
1295                             strstr(ebuf, "The system cannot find the device specified") != NULL)
1296                                 return (NULL);
1297                         error("%s", ebuf);
1298                 }
1299                 if (*ebuf)
1300                         warning("%s", ebuf);
1301                 return (pc);
1302         }
1303 #endif /* HAVE_PCAP_OPEN */
1304
1305 #ifdef HAVE_PCAP_CREATE
1306         pc = pcap_create(device, ebuf);
1307         if (pc == NULL) {
1308                 /*
1309                  * If this failed with "No such device", that means
1310                  * the interface doesn't exist; return NULL, so that
1311                  * the caller can see whether the device name is
1312                  * actually an interface index.
1313                  */
1314                 if (strstr(ebuf, "No such device") != NULL)
1315                         return (NULL);
1316                 error("%s", ebuf);
1317         }
1318 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1319         if (Jflag)
1320                 show_tstamp_types_and_exit(pc, device);
1321 #endif
1322 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1323         status = pcap_set_tstamp_precision(pc, ndo->ndo_tstamp_precision);
1324         if (status != 0)
1325                 error("%s: Can't set %ssecond time stamp precision: %s",
1326                     device,
1327                     tstamp_precision_to_string(ndo->ndo_tstamp_precision),
1328                     pcap_statustostr(status));
1329 #endif
1330
1331 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1332         if (immediate_mode) {
1333                 status = pcap_set_immediate_mode(pc, 1);
1334                 if (status != 0)
1335                         error("%s: Can't set immediate mode: %s",
1336                             device, pcap_statustostr(status));
1337         }
1338 #endif
1339         /*
1340          * Is this an interface that supports monitor mode?
1341          */
1342         if (pcap_can_set_rfmon(pc) == 1)
1343                 supports_monitor_mode = 1;
1344         else
1345                 supports_monitor_mode = 0;
1346         if (ndo->ndo_snaplen != 0) {
1347                 /*
1348                  * A snapshot length was explicitly specified;
1349                  * use it.
1350                  */
1351                 status = pcap_set_snaplen(pc, ndo->ndo_snaplen);
1352                 if (status != 0)
1353                         error("%s: Can't set snapshot length: %s",
1354                             device, pcap_statustostr(status));
1355         }
1356         status = pcap_set_promisc(pc, !pflag);
1357         if (status != 0)
1358                 error("%s: Can't set promiscuous mode: %s",
1359                     device, pcap_statustostr(status));
1360         if (Iflag) {
1361                 status = pcap_set_rfmon(pc, 1);
1362                 if (status != 0)
1363                         error("%s: Can't set monitor mode: %s",
1364                             device, pcap_statustostr(status));
1365         }
1366         status = pcap_set_timeout(pc, timeout);
1367         if (status != 0)
1368                 error("%s: pcap_set_timeout failed: %s",
1369                     device, pcap_statustostr(status));
1370         if (Bflag != 0) {
1371                 status = pcap_set_buffer_size(pc, Bflag);
1372                 if (status != 0)
1373                         error("%s: Can't set buffer size: %s",
1374                             device, pcap_statustostr(status));
1375         }
1376 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1377         if (jflag != -1) {
1378                 status = pcap_set_tstamp_type(pc, jflag);
1379                 if (status < 0)
1380                         error("%s: Can't set time stamp type: %s",
1381                             device, pcap_statustostr(status));
1382                 else if (status > 0)
1383                         warning("When trying to set timestamp type '%s' on %s: %s",
1384                             pcap_tstamp_type_val_to_name(jflag), device,
1385                             pcap_statustostr(status));
1386         }
1387 #endif
1388         status = pcap_activate(pc);
1389         if (status < 0) {
1390                 /*
1391                  * pcap_activate() failed.
1392                  */
1393                 cp = pcap_geterr(pc);
1394                 if (status == PCAP_ERROR)
1395                         error("%s", cp);
1396                 else if (status == PCAP_ERROR_NO_SUCH_DEVICE) {
1397                         /*
1398                          * Return an error for our caller to handle.
1399                          */
1400                         snprintf(ebuf, PCAP_ERRBUF_SIZE, "%s: %s\n(%s)",
1401                             device, pcap_statustostr(status), cp);
1402                 } else if (status == PCAP_ERROR_PERM_DENIED && *cp != '\0')
1403                         error("%s: %s\n(%s)", device,
1404                             pcap_statustostr(status), cp);
1405 #ifdef __FreeBSD__
1406                 else if (status == PCAP_ERROR_RFMON_NOTSUP &&
1407                     strncmp(device, "wlan", 4) == 0) {
1408                         char parent[8], newdev[8];
1409                         char sysctl[32];
1410                         size_t s = sizeof(parent);
1411
1412                         snprintf(sysctl, sizeof(sysctl),
1413                             "net.wlan.%d.%%parent", atoi(device + 4));
1414                         sysctlbyname(sysctl, parent, &s, NULL, 0);
1415                         strlcpy(newdev, device, sizeof(newdev));
1416                         /* Suggest a new wlan device. */
1417                         /* FIXME: incrementing the index this way is not going to work well
1418                          * when the index is 9 or greater but the only consequence in this
1419                          * specific case would be an error message that looks a bit odd.
1420                          */
1421                         newdev[strlen(newdev)-1]++;
1422                         error("%s is not a monitor mode VAP\n"
1423                             "To create a new monitor mode VAP use:\n"
1424                             "  ifconfig %s create wlandev %s wlanmode monitor\n"
1425                             "and use %s as the tcpdump interface",
1426                             device, newdev, parent, newdev);
1427                 }
1428 #endif
1429                 else
1430                         error("%s: %s", device,
1431                             pcap_statustostr(status));
1432                 pcap_close(pc);
1433                 return (NULL);
1434         } else if (status > 0) {
1435                 /*
1436                  * pcap_activate() succeeded, but it's warning us
1437                  * of a problem it had.
1438                  */
1439                 cp = pcap_geterr(pc);
1440                 if (status == PCAP_WARNING)
1441                         warning("%s", cp);
1442                 else if (status == PCAP_WARNING_PROMISC_NOTSUP &&
1443                          *cp != '\0')
1444                         warning("%s: %s\n(%s)", device,
1445                             pcap_statustostr(status), cp);
1446                 else
1447                         warning("%s: %s", device,
1448                             pcap_statustostr(status));
1449         }
1450 #ifdef HAVE_PCAP_SETDIRECTION
1451         if (Qflag != -1) {
1452                 status = pcap_setdirection(pc, Qflag);
1453                 if (status != 0)
1454                         error("%s: pcap_setdirection() failed: %s",
1455                               device,  pcap_geterr(pc));
1456                 }
1457 #endif /* HAVE_PCAP_SETDIRECTION */
1458 #else /* HAVE_PCAP_CREATE */
1459         *ebuf = '\0';
1460         /*
1461          * If no snapshot length was specified, or a length of 0 was
1462          * specified, default to 256KB.
1463          */
1464         if (ndo->ndo_snaplen == 0)
1465                 ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
1466         pc = pcap_open_live(device, ndo->ndo_snaplen, !pflag, timeout, ebuf);
1467         if (pc == NULL) {
1468                 /*
1469                  * If this failed with "No such device", that means
1470                  * the interface doesn't exist; return NULL, so that
1471                  * the caller can see whether the device name is
1472                  * actually an interface index.
1473                  */
1474                 if (strstr(ebuf, "No such device") != NULL)
1475                         return (NULL);
1476                 error("%s", ebuf);
1477         }
1478         if (*ebuf)
1479                 warning("%s", ebuf);
1480 #endif /* HAVE_PCAP_CREATE */
1481
1482         return (pc);
1483 }
1484
1485 int
1486 main(int argc, char **argv)
1487 {
1488         int cnt, op, i;
1489         bpf_u_int32 localnet = 0, netmask = 0;
1490         char *cp, *infile, *cmdbuf, *device, *RFileName, *VFileName, *WFileName;
1491         char *endp;
1492         pcap_handler callback;
1493         int dlt;
1494         const char *dlt_name;
1495         struct bpf_program fcode;
1496 #ifndef _WIN32
1497         void (*oldhandler)(int);
1498 #endif
1499         struct dump_info dumpinfo;
1500         u_char *pcap_userdata;
1501         char ebuf[PCAP_ERRBUF_SIZE];
1502         char VFileLine[PATH_MAX + 1];
1503         const char *username = NULL;
1504 #ifndef _WIN32
1505         const char *chroot_dir = NULL;
1506 #endif
1507         char *ret = NULL;
1508         char *end;
1509 #ifdef HAVE_PCAP_FINDALLDEVS
1510         pcap_if_t *devlist;
1511         long devnum;
1512 #endif
1513         int status;
1514         FILE *VFile;
1515 #ifdef HAVE_CAPSICUM
1516         cap_rights_t rights;
1517         int cansandbox;
1518 #endif  /* HAVE_CAPSICUM */
1519         int Oflag = 1;                  /* run filter code optimizer */
1520         int yflag_dlt = -1;
1521         const char *yflag_dlt_name = NULL;
1522         int print = 0;
1523
1524         netdissect_options Ndo;
1525         netdissect_options *ndo = &Ndo;
1526
1527         /*
1528          * Initialize the netdissect code.
1529          */
1530         if (nd_init(ebuf, sizeof(ebuf)) == -1)
1531                 error("%s", ebuf);
1532
1533         memset(ndo, 0, sizeof(*ndo));
1534         ndo_set_function_pointers(ndo);
1535
1536         cnt = -1;
1537         device = NULL;
1538         infile = NULL;
1539         RFileName = NULL;
1540         VFileName = NULL;
1541         VFile = NULL;
1542         WFileName = NULL;
1543         dlt = -1;
1544         if ((cp = strrchr(argv[0], PATH_SEPARATOR)) != NULL)
1545                 ndo->program_name = program_name = cp + 1;
1546         else
1547                 ndo->program_name = program_name = argv[0];
1548
1549 #if defined(HAVE_PCAP_WSOCKINIT)
1550         if (pcap_wsockinit() != 0)
1551                 error("Attempting to initialize Winsock failed");
1552 #elif defined(HAVE_WSOCKINIT)
1553         if (wsockinit() != 0)
1554                 error("Attempting to initialize Winsock failed");
1555 #endif
1556
1557         /*
1558          * On platforms where the CPU doesn't support unaligned loads,
1559          * force unaligned accesses to abort with SIGBUS, rather than
1560          * being fixed up (slowly) by the OS kernel; on those platforms,
1561          * misaligned accesses are bugs, and we want tcpdump to crash so
1562          * that the bugs are reported.
1563          */
1564         if (abort_on_misalignment(ebuf, sizeof(ebuf)) < 0)
1565                 error("%s", ebuf);
1566
1567         while (
1568             (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
1569                 switch (op) {
1570
1571                 case 'a':
1572                         /* compatibility for old -a */
1573                         break;
1574
1575                 case 'A':
1576                         ++ndo->ndo_Aflag;
1577                         break;
1578
1579                 case 'b':
1580                         ++ndo->ndo_bflag;
1581                         break;
1582
1583 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
1584                 case 'B':
1585                         Bflag = atoi(optarg)*1024;
1586                         if (Bflag <= 0)
1587                                 error("invalid packet buffer size %s", optarg);
1588                         break;
1589 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
1590
1591                 case 'c':
1592                         cnt = atoi(optarg);
1593                         if (cnt <= 0)
1594                                 error("invalid packet count %s", optarg);
1595                         break;
1596
1597                 case 'C':
1598                         errno = 0;
1599 #ifdef HAVE_PCAP_DUMP_FTELL64
1600                         Cflag = strtoint64_t(optarg, &endp, 10);
1601 #else
1602                         Cflag = strtol(optarg, &endp, 10);
1603 #endif
1604                         if (endp == optarg || *endp != '\0' || errno != 0
1605                             || Cflag <= 0)
1606                                 error("invalid file size %s", optarg);
1607                         /*
1608                          * Will multiplying it by 1000000 overflow?
1609                          */
1610 #ifdef HAVE_PCAP_DUMP_FTELL64
1611                         if (Cflag > INT64_T_CONSTANT(0x7fffffffffffffff) / 1000000)
1612 #else
1613                         if (Cflag > LONG_MAX / 1000000)
1614 #endif
1615                                 error("file size %s is too large", optarg);
1616                         Cflag *= 1000000;
1617                         break;
1618
1619                 case 'd':
1620                         ++dflag;
1621                         break;
1622
1623 #ifdef HAVE_PCAP_FINDALLDEVS
1624                 case 'D':
1625                         Dflag++;
1626                         break;
1627 #endif
1628
1629 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1630                 case OPTION_LIST_REMOTE_INTERFACES:
1631                         remote_interfaces_source = optarg;
1632                         break;
1633 #endif
1634
1635                 case 'L':
1636                         Lflag++;
1637                         break;
1638
1639                 case 'e':
1640                         ++ndo->ndo_eflag;
1641                         break;
1642
1643                 case 'E':
1644 #ifndef HAVE_LIBCRYPTO
1645                         warning("crypto code not compiled in");
1646 #endif
1647                         ndo->ndo_espsecret = optarg;
1648                         break;
1649
1650                 case 'f':
1651                         ++ndo->ndo_fflag;
1652                         break;
1653
1654                 case 'F':
1655                         infile = optarg;
1656                         break;
1657
1658                 case 'G':
1659                         Gflag = atoi(optarg);
1660                         if (Gflag < 0)
1661                                 error("invalid number of seconds %s", optarg);
1662
1663                         /* We will create one file initially. */
1664                         Gflag_count = 0;
1665
1666                         /* Grab the current time for rotation use. */
1667                         if ((Gflag_time = time(NULL)) == (time_t)-1) {
1668                                 error("%s: can't get current time: %s",
1669                                     __func__, pcap_strerror(errno));
1670                         }
1671                         break;
1672
1673                 case 'h':
1674                         print_usage(stdout);
1675                         exit_tcpdump(S_SUCCESS);
1676                         break;
1677
1678                 case 'H':
1679                         ++ndo->ndo_Hflag;
1680                         break;
1681
1682                 case 'i':
1683                         device = optarg;
1684                         break;
1685
1686 #ifdef HAVE_PCAP_CREATE
1687                 case 'I':
1688                         ++Iflag;
1689                         break;
1690 #endif /* HAVE_PCAP_CREATE */
1691
1692 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1693                 case 'j':
1694                         jflag = pcap_tstamp_type_name_to_val(optarg);
1695                         if (jflag < 0)
1696                                 error("invalid time stamp type %s", optarg);
1697                         break;
1698
1699                 case 'J':
1700                         Jflag++;
1701                         break;
1702 #endif
1703
1704                 case 'l':
1705 #ifdef _WIN32
1706                         /*
1707                          * _IOLBF is the same as _IOFBF in Microsoft's C
1708                          * libraries; the only alternative they offer
1709                          * is _IONBF.
1710                          *
1711                          * XXX - this should really be checking for MSVC++,
1712                          * not _WIN32, if, for example, MinGW has its own
1713                          * C library that is more UNIX-compatible.
1714                          */
1715                         setvbuf(stdout, NULL, _IONBF, 0);
1716 #else /* _WIN32 */
1717 #ifdef HAVE_SETLINEBUF
1718                         setlinebuf(stdout);
1719 #else
1720                         setvbuf(stdout, NULL, _IOLBF, 0);
1721 #endif
1722 #endif /* _WIN32 */
1723                         lflag = 1;
1724                         break;
1725
1726                 case 'K':
1727                         ++ndo->ndo_Kflag;
1728                         break;
1729
1730                 case 'm':
1731                         if (nd_have_smi_support()) {
1732                                 if (nd_load_smi_module(optarg, ebuf, sizeof(ebuf)) == -1)
1733                                         error("%s", ebuf);
1734                         } else {
1735                                 (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
1736                                               program_name, optarg);
1737                                 (void)fprintf(stderr, "(no libsmi support)\n");
1738                         }
1739                         break;
1740
1741                 case 'M':
1742                         /* TCP-MD5 shared secret */
1743 #ifndef HAVE_LIBCRYPTO
1744                         warning("crypto code not compiled in");
1745 #endif
1746                         ndo->ndo_sigsecret = optarg;
1747                         break;
1748
1749                 case 'n':
1750                         ++ndo->ndo_nflag;
1751                         break;
1752
1753                 case 'N':
1754                         ++ndo->ndo_Nflag;
1755                         break;
1756
1757                 case 'O':
1758                         Oflag = 0;
1759                         break;
1760
1761                 case 'p':
1762                         ++pflag;
1763                         break;
1764
1765                 case 'q':
1766                         ++ndo->ndo_qflag;
1767                         ++ndo->ndo_suppress_default_print;
1768                         break;
1769
1770 #ifdef HAVE_PCAP_SETDIRECTION
1771                 case 'Q':
1772                         if (ascii_strcasecmp(optarg, "in") == 0)
1773                                 Qflag = PCAP_D_IN;
1774                         else if (ascii_strcasecmp(optarg, "out") == 0)
1775                                 Qflag = PCAP_D_OUT;
1776                         else if (ascii_strcasecmp(optarg, "inout") == 0)
1777                                 Qflag = PCAP_D_INOUT;
1778                         else
1779                                 error("unknown capture direction `%s'", optarg);
1780                         break;
1781 #endif /* HAVE_PCAP_SETDIRECTION */
1782
1783                 case 'r':
1784                         RFileName = optarg;
1785                         break;
1786
1787                 case 's':
1788                         ndo->ndo_snaplen = (int)strtol(optarg, &end, 0);
1789                         if (optarg == end || *end != '\0'
1790                             || ndo->ndo_snaplen < 0 || ndo->ndo_snaplen > MAXIMUM_SNAPLEN)
1791                                 error("invalid snaplen %s (must be >= 0 and <= %d)",
1792                                       optarg, MAXIMUM_SNAPLEN);
1793                         break;
1794
1795                 case 'S':
1796                         ++ndo->ndo_Sflag;
1797                         break;
1798
1799                 case 't':
1800                         ++ndo->ndo_tflag;
1801                         break;
1802
1803                 case 'T':
1804                         if (ascii_strcasecmp(optarg, "vat") == 0)
1805                                 ndo->ndo_packettype = PT_VAT;
1806                         else if (ascii_strcasecmp(optarg, "wb") == 0)
1807                                 ndo->ndo_packettype = PT_WB;
1808                         else if (ascii_strcasecmp(optarg, "rpc") == 0)
1809                                 ndo->ndo_packettype = PT_RPC;
1810                         else if (ascii_strcasecmp(optarg, "rtp") == 0)
1811                                 ndo->ndo_packettype = PT_RTP;
1812                         else if (ascii_strcasecmp(optarg, "rtcp") == 0)
1813                                 ndo->ndo_packettype = PT_RTCP;
1814                         else if (ascii_strcasecmp(optarg, "snmp") == 0)
1815                                 ndo->ndo_packettype = PT_SNMP;
1816                         else if (ascii_strcasecmp(optarg, "cnfp") == 0)
1817                                 ndo->ndo_packettype = PT_CNFP;
1818                         else if (ascii_strcasecmp(optarg, "tftp") == 0)
1819                                 ndo->ndo_packettype = PT_TFTP;
1820                         else if (ascii_strcasecmp(optarg, "aodv") == 0)
1821                                 ndo->ndo_packettype = PT_AODV;
1822                         else if (ascii_strcasecmp(optarg, "carp") == 0)
1823                                 ndo->ndo_packettype = PT_CARP;
1824                         else if (ascii_strcasecmp(optarg, "radius") == 0)
1825                                 ndo->ndo_packettype = PT_RADIUS;
1826                         else if (ascii_strcasecmp(optarg, "zmtp1") == 0)
1827                                 ndo->ndo_packettype = PT_ZMTP1;
1828                         else if (ascii_strcasecmp(optarg, "vxlan") == 0)
1829                                 ndo->ndo_packettype = PT_VXLAN;
1830                         else if (ascii_strcasecmp(optarg, "pgm") == 0)
1831                                 ndo->ndo_packettype = PT_PGM;
1832                         else if (ascii_strcasecmp(optarg, "pgm_zmtp1") == 0)
1833                                 ndo->ndo_packettype = PT_PGM_ZMTP1;
1834                         else if (ascii_strcasecmp(optarg, "lmp") == 0)
1835                                 ndo->ndo_packettype = PT_LMP;
1836                         else if (ascii_strcasecmp(optarg, "resp") == 0)
1837                                 ndo->ndo_packettype = PT_RESP;
1838                         else if (ascii_strcasecmp(optarg, "ptp") == 0)
1839                                 ndo->ndo_packettype = PT_PTP;
1840                         else if (ascii_strcasecmp(optarg, "someip") == 0)
1841                                 ndo->ndo_packettype = PT_SOMEIP;
1842                         else if (ascii_strcasecmp(optarg, "domain") == 0)
1843                                 ndo->ndo_packettype = PT_DOMAIN;
1844                         else
1845                                 error("unknown packet type `%s'", optarg);
1846                         break;
1847
1848                 case 'u':
1849                         ++ndo->ndo_uflag;
1850                         break;
1851
1852 #ifdef HAVE_PCAP_DUMP_FLUSH
1853                 case 'U':
1854                         ++Uflag;
1855                         break;
1856 #endif
1857
1858                 case 'v':
1859                         ++ndo->ndo_vflag;
1860                         break;
1861
1862                 case 'V':
1863                         VFileName = optarg;
1864                         break;
1865
1866                 case 'w':
1867                         WFileName = optarg;
1868                         break;
1869
1870                 case 'W':
1871                         Wflag = atoi(optarg);
1872                         if (Wflag <= 0)
1873                                 error("invalid number of output files %s", optarg);
1874                         WflagChars = getWflagChars(Wflag);
1875                         break;
1876
1877                 case 'x':
1878                         ++ndo->ndo_xflag;
1879                         ++ndo->ndo_suppress_default_print;
1880                         break;
1881
1882                 case 'X':
1883                         ++ndo->ndo_Xflag;
1884                         ++ndo->ndo_suppress_default_print;
1885                         break;
1886
1887                 case 'y':
1888                         yflag_dlt_name = optarg;
1889                         yflag_dlt =
1890                                 pcap_datalink_name_to_val(yflag_dlt_name);
1891                         if (yflag_dlt < 0)
1892                                 error("invalid data link type %s", yflag_dlt_name);
1893                         break;
1894
1895 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
1896                 case 'Y':
1897                         {
1898                         /* Undocumented flag */
1899                         pcap_set_parser_debug(1);
1900                         }
1901                         break;
1902 #endif
1903                 case 'z':
1904                         zflag = optarg;
1905                         break;
1906
1907                 case 'Z':
1908                         username = optarg;
1909                         break;
1910
1911                 case '#':
1912                         ndo->ndo_packet_number = 1;
1913                         break;
1914
1915                 case OPTION_VERSION:
1916                         print_version(stdout);
1917                         exit_tcpdump(S_SUCCESS);
1918                         break;
1919
1920 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1921                 case OPTION_TSTAMP_PRECISION:
1922                         ndo->ndo_tstamp_precision = tstamp_precision_from_string(optarg);
1923                         if (ndo->ndo_tstamp_precision < 0)
1924                                 error("unsupported time stamp precision");
1925                         break;
1926 #endif
1927
1928 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1929                 case OPTION_IMMEDIATE_MODE:
1930                         immediate_mode = 1;
1931                         break;
1932 #endif
1933
1934                 case OPTION_PRINT:
1935                         print = 1;
1936                         break;
1937
1938 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1939                 case OPTION_TSTAMP_MICRO:
1940                         ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
1941                         break;
1942
1943                 case OPTION_TSTAMP_NANO:
1944                         ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_NANO;
1945                         break;
1946 #endif
1947
1948                 case OPTION_FP_TYPE:
1949                         /*
1950                          * Print out the type of floating-point arithmetic
1951                          * we're doing; it's probably IEEE, unless somebody
1952                          * tries to run this on a VAX, but the precision
1953                          * may differ (e.g., it might be 32-bit, 64-bit,
1954                          * or 80-bit).
1955                          */
1956                         float_type_check(0x4e93312d);
1957                         return 0;
1958
1959                 case OPTION_COUNT:
1960                         count_mode = 1;
1961                         break;
1962
1963                 default:
1964                         print_usage(stderr);
1965                         exit_tcpdump(S_ERR_HOST_PROGRAM);
1966                         /* NOTREACHED */
1967                 }
1968
1969 #ifdef HAVE_PCAP_FINDALLDEVS
1970         if (Dflag)
1971                 show_devices_and_exit();
1972 #endif
1973 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1974         if (remote_interfaces_source != NULL)
1975                 show_remote_devices_and_exit();
1976 #endif
1977
1978 #if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK)
1979 /* Set default linktype DLT_LINUX_SLL2 when capturing on the "any" device */
1980                 if (device != NULL &&
1981                     strncmp (device, "any", strlen("any")) == 0
1982                     && yflag_dlt == -1)
1983                         yflag_dlt = DLT_LINUX_SLL2;
1984 #endif
1985
1986         switch (ndo->ndo_tflag) {
1987
1988         case 0: /* Default */
1989         case 1: /* No time stamp */
1990         case 2: /* Unix timeval style */
1991         case 3: /* Microseconds/nanoseconds since previous packet */
1992         case 4: /* Date + Default */
1993         case 5: /* Microseconds/nanoseconds since first packet */
1994                 break;
1995
1996         default: /* Not supported */
1997                 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
1998                 break;
1999         }
2000
2001         if (ndo->ndo_fflag != 0 && (VFileName != NULL || RFileName != NULL))
2002                 error("-f can not be used with -V or -r");
2003
2004         if (VFileName != NULL && RFileName != NULL)
2005                 error("-V and -r are mutually exclusive.");
2006
2007         /*
2008          * If we're printing dissected packets to the standard output,
2009          * and either the standard output is a terminal or we're doing
2010          * "line" buffering, set the capture timeout to .1 second rather
2011          * than 1 second, as the user's probably expecting to see packets
2012          * pop up immediately shortly after they arrive.
2013          *
2014          * XXX - would there be some value appropriate for all cases,
2015          * based on, say, the buffer size and packet input rate?
2016          */
2017         if ((WFileName == NULL || print) && (isatty(1) || lflag))
2018                 timeout = 100;
2019
2020 #ifdef WITH_CHROOT
2021         /* if run as root, prepare for chrooting */
2022         if (getuid() == 0 || geteuid() == 0) {
2023                 /* future extensibility for cmd-line arguments */
2024                 if (!chroot_dir)
2025                         chroot_dir = WITH_CHROOT;
2026         }
2027 #endif
2028
2029 #ifdef WITH_USER
2030         /* if run as root, prepare for dropping root privileges */
2031         if (getuid() == 0 || geteuid() == 0) {
2032                 /* Run with '-Z root' to restore old behaviour */
2033                 if (!username)
2034                         username = WITH_USER;
2035         }
2036 #endif
2037
2038         if (RFileName != NULL || VFileName != NULL) {
2039                 /*
2040                  * If RFileName is non-null, it's the pathname of a
2041                  * savefile to read.  If VFileName is non-null, it's
2042                  * the pathname of a file containing a list of pathnames
2043                  * (one per line) of savefiles to read.
2044                  *
2045                  * In either case, we're reading a savefile, not doing
2046                  * a live capture.
2047                  */
2048 #ifndef _WIN32
2049                 /*
2050                  * We don't need network access, so relinquish any set-UID
2051                  * or set-GID privileges we have (if any).
2052                  *
2053                  * We do *not* want set-UID privileges when opening a
2054                  * trace file, as that might let the user read other
2055                  * people's trace files (especially if we're set-UID
2056                  * root).
2057                  */
2058                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
2059                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
2060 #endif /* _WIN32 */
2061                 if (VFileName != NULL) {
2062                         if (VFileName[0] == '-' && VFileName[1] == '\0')
2063                                 VFile = stdin;
2064                         else
2065                                 VFile = fopen(VFileName, "r");
2066
2067                         if (VFile == NULL)
2068                                 error("Unable to open file: %s\n", pcap_strerror(errno));
2069
2070                         ret = get_next_file(VFile, VFileLine);
2071                         if (!ret)
2072                                 error("Nothing in %s\n", VFileName);
2073                         RFileName = VFileLine;
2074                 }
2075
2076 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
2077                 pd = pcap_open_offline_with_tstamp_precision(RFileName,
2078                     ndo->ndo_tstamp_precision, ebuf);
2079 #else
2080                 pd = pcap_open_offline(RFileName, ebuf);
2081 #endif
2082
2083                 if (pd == NULL)
2084                         error("%s", ebuf);
2085 #ifdef HAVE_CAPSICUM
2086                 cap_rights_init(&rights, CAP_READ);
2087                 if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
2088                     errno != ENOSYS) {
2089                         error("unable to limit pcap descriptor");
2090                 }
2091 #endif
2092                 dlt = pcap_datalink(pd);
2093                 dlt_name = pcap_datalink_val_to_name(dlt);
2094                 fprintf(stderr, "reading from file %s", RFileName);
2095                 if (dlt_name == NULL) {
2096                         fprintf(stderr, ", link-type %u", dlt);
2097                 } else {
2098                         fprintf(stderr, ", link-type %s (%s)", dlt_name,
2099                                 pcap_datalink_val_to_description(dlt));
2100                 }
2101                 fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2102 #ifdef DLT_LINUX_SLL2
2103                 if (dlt == DLT_LINUX_SLL2)
2104                         fprintf(stderr, "Warning: interface names might be incorrect\n");
2105 #endif
2106         } else if (dflag && !device) {
2107                 int dump_dlt = DLT_EN10MB;
2108                 /*
2109                  * We're dumping the compiled code without an explicit
2110                  * device specification.  (If a device is specified, we
2111                  * definitely want to open it to use the DLT of that device.)
2112                  * Either default to DLT_EN10MB with a warning, or use
2113                  * the user-specified value if supplied.
2114                  */
2115                 /*
2116                  * If no snapshot length was specified, or a length of 0 was
2117                  * specified, default to 256KB.
2118                  */
2119                 if (ndo->ndo_snaplen == 0)
2120                         ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
2121                 /*
2122                  * If a DLT was specified with the -y flag, use that instead.
2123                  */
2124                 if (yflag_dlt != -1)
2125                         dump_dlt = yflag_dlt;
2126                 else
2127                         fprintf(stderr, "Warning: assuming Ethernet\n");
2128                 pd = pcap_open_dead(dump_dlt, ndo->ndo_snaplen);
2129         } else {
2130                 /*
2131                  * We're doing a live capture.
2132                  */
2133                 if (device == NULL) {
2134                         /*
2135                          * No interface was specified.  Pick one.
2136                          */
2137 #ifdef HAVE_PCAP_FINDALLDEVS
2138                         /*
2139                          * Find the list of interfaces, and pick
2140                          * the first interface.
2141                          */
2142                         if (pcap_findalldevs(&devlist, ebuf) == -1)
2143                                 error("%s", ebuf);
2144                         if (devlist == NULL)
2145                                 error("no interfaces available for capture");
2146                         device = strdup(devlist->name);
2147                         pcap_freealldevs(devlist);
2148 #else /* HAVE_PCAP_FINDALLDEVS */
2149                         /*
2150                          * Use whatever interface pcap_lookupdev()
2151                          * chooses.
2152                          */
2153                         device = pcap_lookupdev(ebuf);
2154                         if (device == NULL)
2155                                 error("%s", ebuf);
2156 #endif
2157                 }
2158
2159                 /*
2160                  * Try to open the interface with the specified name.
2161                  */
2162                 pd = open_interface(device, ndo, ebuf);
2163                 if (pd == NULL) {
2164                         /*
2165                          * That failed.  If we can get a list of
2166                          * interfaces, and the interface name
2167                          * is purely numeric, try to use it as
2168                          * a 1-based index in the list of
2169                          * interfaces.
2170                          */
2171 #ifdef HAVE_PCAP_FINDALLDEVS
2172                         devnum = parse_interface_number(device);
2173                         if (devnum == -1) {
2174                                 /*
2175                                  * It's not a number; just report
2176                                  * the open error and fail.
2177                                  */
2178                                 error("%s", ebuf);
2179                         }
2180
2181                         /*
2182                          * OK, it's a number; try to find the
2183                          * interface with that index, and try
2184                          * to open it.
2185                          *
2186                          * find_interface_by_number() exits if it
2187                          * couldn't be found.
2188                          */
2189                         device = find_interface_by_number(device, devnum);
2190                         pd = open_interface(device, ndo, ebuf);
2191                         if (pd == NULL)
2192                                 error("%s", ebuf);
2193 #else /* HAVE_PCAP_FINDALLDEVS */
2194                         /*
2195                          * We can't get a list of interfaces; just
2196                          * fail.
2197                          */
2198                         error("%s", ebuf);
2199 #endif /* HAVE_PCAP_FINDALLDEVS */
2200                 }
2201
2202                 /*
2203                  * Let user own process after capture device has
2204                  * been opened.
2205                  */
2206 #ifndef _WIN32
2207                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
2208                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
2209 #endif /* _WIN32 */
2210 #if !defined(HAVE_PCAP_CREATE) && defined(_WIN32)
2211                 if(Bflag != 0)
2212                         if(pcap_setbuff(pd, Bflag)==-1){
2213                                 error("%s", pcap_geterr(pd));
2214                         }
2215 #endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
2216                 if (Lflag)
2217                         show_dlts_and_exit(pd, device);
2218                 if (yflag_dlt >= 0) {
2219 #ifdef HAVE_PCAP_SET_DATALINK
2220                         if (pcap_set_datalink(pd, yflag_dlt) < 0)
2221                                 error("%s", pcap_geterr(pd));
2222 #else
2223                         /*
2224                          * We don't actually support changing the
2225                          * data link type, so we only let them
2226                          * set it to what it already is.
2227                          */
2228                         if (yflag_dlt != pcap_datalink(pd)) {
2229                                 error("%s is not one of the DLTs supported by this device\n",
2230                                       yflag_dlt_name);
2231                         }
2232 #endif
2233                         (void)fprintf(stderr, "%s: data link type %s\n",
2234                                       program_name,
2235                                       pcap_datalink_val_to_name(yflag_dlt));
2236                         (void)fflush(stderr);
2237                 }
2238                 i = pcap_snapshot(pd);
2239                 if (ndo->ndo_snaplen < i) {
2240                         if (ndo->ndo_snaplen != 0)
2241                                 warning("snaplen raised from %d to %d", ndo->ndo_snaplen, i);
2242                         ndo->ndo_snaplen = i;
2243                 } else if (ndo->ndo_snaplen > i) {
2244                         warning("snaplen lowered from %d to %d", ndo->ndo_snaplen, i);
2245                         ndo->ndo_snaplen = i;
2246                 }
2247                 if(ndo->ndo_fflag != 0) {
2248                         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
2249                                 warning("foreign (-f) flag used but: %s", ebuf);
2250                         }
2251                 }
2252
2253         }
2254         if (infile)
2255                 cmdbuf = read_infile(infile);
2256         else
2257                 cmdbuf = copy_argv(&argv[optind]);
2258
2259 #ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
2260         pcap_set_optimizer_debug(dflag);
2261 #endif
2262         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2263                 error("%s", pcap_geterr(pd));
2264         if (dflag) {
2265                 bpf_dump(&fcode, dflag);
2266                 pcap_close(pd);
2267                 free(cmdbuf);
2268                 pcap_freecode(&fcode);
2269                 exit_tcpdump(S_SUCCESS);
2270         }
2271
2272 #ifdef HAVE_CASPER
2273         if (!ndo->ndo_nflag)
2274                 capdns = capdns_setup();
2275 #endif  /* HAVE_CASPER */
2276
2277         init_print(ndo, localnet, netmask);
2278
2279 #ifndef _WIN32
2280         (void)setsignal(SIGPIPE, cleanup);
2281         (void)setsignal(SIGTERM, cleanup);
2282 #endif /* _WIN32 */
2283         (void)setsignal(SIGINT, cleanup);
2284 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2285         (void)setsignal(SIGCHLD, child_cleanup);
2286 #endif
2287         /* Cooperate with nohup(1) */
2288 #ifndef _WIN32
2289         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
2290                 (void)setsignal(SIGHUP, oldhandler);
2291 #endif /* _WIN32 */
2292
2293 #ifndef _WIN32
2294         /*
2295          * If a user name was specified with "-Z", attempt to switch to
2296          * that user's UID.  This would probably be used with sudo,
2297          * to allow tcpdump to be run in a special restricted
2298          * account (if you just want to allow users to open capture
2299          * devices, and can't just give users that permission,
2300          * you'd make tcpdump set-UID or set-GID).
2301          *
2302          * Tcpdump doesn't necessarily write only to one savefile;
2303          * the general only way to allow a -Z instance to write to
2304          * savefiles as the user under whose UID it's run, rather
2305          * than as the user specified with -Z, would thus be to switch
2306          * to the original user ID before opening a capture file and
2307          * then switch back to the -Z user ID after opening the savefile.
2308          * Switching to the -Z user ID only after opening the first
2309          * savefile doesn't handle the general case.
2310          */
2311
2312         if (getuid() == 0 || geteuid() == 0) {
2313 #ifdef HAVE_LIBCAP_NG
2314                 /* Initialize capng */
2315                 capng_clear(CAPNG_SELECT_BOTH);
2316                 if (username) {
2317 DIAG_OFF_ASSIGN_ENUM
2318                         capng_updatev(
2319                                 CAPNG_ADD,
2320                                 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2321                                 CAP_SETUID,
2322                                 CAP_SETGID,
2323                                 -1);
2324 DIAG_ON_ASSIGN_ENUM
2325                 }
2326                 if (chroot_dir) {
2327 DIAG_OFF_ASSIGN_ENUM
2328                         capng_update(
2329                                 CAPNG_ADD,
2330                                 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2331                                 CAP_SYS_CHROOT
2332                                 );
2333 DIAG_ON_ASSIGN_ENUM
2334                 }
2335
2336                 if (WFileName) {
2337 DIAG_OFF_ASSIGN_ENUM
2338                         capng_update(
2339                                 CAPNG_ADD,
2340                                 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2341                                 CAP_DAC_OVERRIDE
2342                                 );
2343 DIAG_ON_ASSIGN_ENUM
2344                 }
2345                 capng_apply(CAPNG_SELECT_BOTH);
2346 #endif /* HAVE_LIBCAP_NG */
2347                 if (username || chroot_dir)
2348                         droproot(username, chroot_dir);
2349
2350         }
2351 #endif /* _WIN32 */
2352
2353         if (pcap_setfilter(pd, &fcode) < 0)
2354                 error("%s", pcap_geterr(pd));
2355 #ifdef HAVE_CAPSICUM
2356         if (RFileName == NULL && VFileName == NULL && pcap_fileno(pd) != -1) {
2357                 static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
2358
2359                 /*
2360                  * The various libpcap devices use a combination of
2361                  * read (bpf), ioctl (bpf, netmap), poll (netmap)
2362                  * so we add the relevant access rights.
2363                  */
2364                 cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
2365                 if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
2366                     errno != ENOSYS) {
2367                         error("unable to limit pcap descriptor");
2368                 }
2369                 if (cap_ioctls_limit(pcap_fileno(pd), cmds,
2370                     sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
2371                         error("unable to limit ioctls on pcap descriptor");
2372                 }
2373         }
2374 #endif
2375         if (WFileName) {
2376                 /* Do not exceed the default PATH_MAX for files. */
2377                 dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
2378
2379                 if (dumpinfo.CurrentFileName == NULL)
2380                         error("malloc of dumpinfo.CurrentFileName");
2381
2382                 /* We do not need numbering for dumpfiles if Cflag isn't set. */
2383                 if (Cflag != 0)
2384                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
2385                 else
2386                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
2387
2388                 pdd = pcap_dump_open(pd, dumpinfo.CurrentFileName);
2389 #ifdef HAVE_LIBCAP_NG
2390                 /* Give up CAP_DAC_OVERRIDE capability.
2391                  * Only allow it to be restored if the -C or -G flag have been
2392                  * set since we may need to create more files later on.
2393                  */
2394                 capng_update(
2395                         CAPNG_DROP,
2396                         (Cflag || Gflag ? 0 : CAPNG_PERMITTED)
2397                                 | CAPNG_EFFECTIVE,
2398                         CAP_DAC_OVERRIDE
2399                         );
2400                 capng_apply(CAPNG_SELECT_BOTH);
2401 #endif /* HAVE_LIBCAP_NG */
2402                 if (pdd == NULL)
2403                         error("%s", pcap_geterr(pd));
2404 #ifdef HAVE_CAPSICUM
2405                 set_dumper_capsicum_rights(pdd);
2406 #endif
2407                 if (Cflag != 0 || Gflag != 0) {
2408 #ifdef HAVE_CAPSICUM
2409                         /*
2410                          * basename() and dirname() may modify their input buffer
2411                          * and they do since FreeBSD 12.0, but they didn't before.
2412                          * Hence use the return value only, but always assume the
2413                          * input buffer has been modified and would need to be
2414                          * reset before the next use.
2415                          */
2416                         char *WFileName_copy;
2417
2418                         if ((WFileName_copy = strdup(WFileName)) == NULL) {
2419                                 error("Unable to allocate memory for file %s",
2420                                     WFileName);
2421                         }
2422                         DIAG_OFF_C11_EXTENSIONS
2423                         dumpinfo.WFileName = strdup(basename(WFileName_copy));
2424                         DIAG_ON_C11_EXTENSIONS
2425                         if (dumpinfo.WFileName == NULL) {
2426                                 error("Unable to allocate memory for file %s",
2427                                     WFileName);
2428                         }
2429                         free(WFileName_copy);
2430
2431                         if ((WFileName_copy = strdup(WFileName)) == NULL) {
2432                                 error("Unable to allocate memory for file %s",
2433                                     WFileName);
2434                         }
2435                         DIAG_OFF_C11_EXTENSIONS
2436                         char *WFileName_dirname = dirname(WFileName_copy);
2437                         DIAG_ON_C11_EXTENSIONS
2438                         dumpinfo.dirfd = open(WFileName_dirname,
2439                             O_DIRECTORY | O_RDONLY);
2440                         if (dumpinfo.dirfd < 0) {
2441                                 error("unable to open directory %s",
2442                                     WFileName_dirname);
2443                         }
2444                         free(WFileName_dirname);
2445                         free(WFileName_copy);
2446
2447                         cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
2448                             CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
2449                         if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
2450                             errno != ENOSYS) {
2451                                 error("unable to limit directory rights");
2452                         }
2453                         if (cap_fcntls_limit(dumpinfo.dirfd, CAP_FCNTL_GETFL) < 0 &&
2454                             errno != ENOSYS) {
2455                                 error("unable to limit dump descriptor fcntls");
2456                         }
2457 #else   /* !HAVE_CAPSICUM */
2458                         dumpinfo.WFileName = WFileName;
2459 #endif
2460                         callback = dump_packet_and_trunc;
2461                         dumpinfo.pd = pd;
2462                         dumpinfo.pdd = pdd;
2463                         pcap_userdata = (u_char *)&dumpinfo;
2464                 } else {
2465                         callback = dump_packet;
2466                         dumpinfo.WFileName = WFileName;
2467                         dumpinfo.pd = pd;
2468                         dumpinfo.pdd = pdd;
2469                         pcap_userdata = (u_char *)&dumpinfo;
2470                 }
2471                 if (print) {
2472                         dlt = pcap_datalink(pd);
2473                         ndo->ndo_if_printer = get_if_printer(dlt);
2474                         dumpinfo.ndo = ndo;
2475                 } else
2476                         dumpinfo.ndo = NULL;
2477
2478 #ifdef HAVE_PCAP_DUMP_FLUSH
2479                 if (Uflag)
2480                         pcap_dump_flush(pdd);
2481 #endif
2482         } else {
2483                 dlt = pcap_datalink(pd);
2484                 ndo->ndo_if_printer = get_if_printer(dlt);
2485                 callback = print_packet;
2486                 pcap_userdata = (u_char *)ndo;
2487         }
2488
2489 #ifdef SIGNAL_REQ_INFO
2490         /*
2491          * We can't get statistics when reading from a file rather
2492          * than capturing from a device.
2493          */
2494         if (RFileName == NULL)
2495                 (void)setsignal(SIGNAL_REQ_INFO, requestinfo);
2496 #endif
2497 #ifdef SIGNAL_FLUSH_PCAP
2498         (void)setsignal(SIGNAL_FLUSH_PCAP, flushpcap);
2499 #endif
2500
2501         if (ndo->ndo_vflag > 0 && WFileName && RFileName == NULL && !print) {
2502                 /*
2503                  * When capturing to a file, if "--print" wasn't specified,
2504                  *"-v" means tcpdump should, once per second,
2505                  * "v"erbosely report the number of packets captured.
2506                  * Except when reading from a file, because -r, -w and -v
2507                  * together used to make a corner case, in which pcap_loop()
2508                  * errored due to EINTR (see GH #155 for details).
2509                  */
2510 #ifdef _WIN32
2511                 /*
2512                  * https://blogs.msdn.microsoft.com/oldnewthing/20151230-00/?p=92741
2513                  *
2514                  * suggests that this dates back to W2K.
2515                  *
2516                  * I don't know what a "long wait" is, but we'll assume
2517                  * that printing the stats could be a "long wait".
2518                  */
2519                 CreateTimerQueueTimer(&timer_handle, NULL,
2520                     verbose_stats_dump, NULL, 1000, 1000,
2521                     WT_EXECUTEDEFAULT|WT_EXECUTELONGFUNCTION);
2522                 setvbuf(stderr, NULL, _IONBF, 0);
2523 #else /* _WIN32 */
2524                 /*
2525                  * Assume this is UN*X, and that it has setitimer(); that
2526                  * dates back to UNIX 95.
2527                  */
2528                 struct itimerval timer;
2529                 (void)setsignal(SIGALRM, verbose_stats_dump);
2530                 timer.it_interval.tv_sec = 1;
2531                 timer.it_interval.tv_usec = 0;
2532                 timer.it_value.tv_sec = 1;
2533                 timer.it_value.tv_usec = 1;
2534                 setitimer(ITIMER_REAL, &timer, NULL);
2535 #endif /* _WIN32 */
2536         }
2537
2538         if (RFileName == NULL) {
2539                 /*
2540                  * Live capture (if -V was specified, we set RFileName
2541                  * to a file from the -V file).  Print a message to
2542                  * the standard error on UN*X.
2543                  */
2544                 if (!ndo->ndo_vflag && !WFileName) {
2545                         (void)fprintf(stderr,
2546                             "%s: verbose output suppressed, use -v[v]... for full protocol decode\n",
2547                             program_name);
2548                 } else
2549                         (void)fprintf(stderr, "%s: ", program_name);
2550                 dlt = pcap_datalink(pd);
2551                 dlt_name = pcap_datalink_val_to_name(dlt);
2552                 (void)fprintf(stderr, "listening on %s", device);
2553                 if (dlt_name == NULL) {
2554                         (void)fprintf(stderr, ", link-type %u", dlt);
2555                 } else {
2556                         (void)fprintf(stderr, ", link-type %s (%s)", dlt_name,
2557                                       pcap_datalink_val_to_description(dlt));
2558                 }
2559                 (void)fprintf(stderr, ", snapshot length %d bytes\n", ndo->ndo_snaplen);
2560                 (void)fflush(stderr);
2561         }
2562
2563 #ifdef HAVE_CAPSICUM
2564         cansandbox = (VFileName == NULL && zflag == NULL &&
2565             ndo->ndo_espsecret == NULL);
2566 #ifdef HAVE_CASPER
2567         cansandbox = (cansandbox && (ndo->ndo_nflag || capdns != NULL));
2568 #else
2569         cansandbox = (cansandbox && ndo->ndo_nflag);
2570 #endif  /* HAVE_CASPER */
2571         cansandbox = (cansandbox && (pcap_fileno(pd) != -1 ||
2572             RFileName != NULL));
2573
2574         if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
2575                 error("unable to enter the capability mode");
2576 #endif  /* HAVE_CAPSICUM */
2577
2578         do {
2579                 status = pcap_loop(pd, cnt, callback, pcap_userdata);
2580                 if (WFileName == NULL) {
2581                         /*
2582                          * We're printing packets.  Flush the printed output,
2583                          * so it doesn't get intermingled with error output.
2584                          */
2585                         if (status == -2) {
2586                                 /*
2587                                  * We got interrupted, so perhaps we didn't
2588                                  * manage to finish a line we were printing.
2589                                  * Print an extra newline, just in case.
2590                                  */
2591                                 putchar('\n');
2592                         }
2593                         (void)fflush(stdout);
2594                 }
2595                 if (status == -2) {
2596                         /*
2597                          * We got interrupted. If we are reading multiple
2598                          * files (via -V) set these so that we stop.
2599                          */
2600                         VFileName = NULL;
2601                         ret = NULL;
2602                 }
2603                 if (status == -1) {
2604                         /*
2605                          * Error.  Report it.
2606                          */
2607                         (void)fprintf(stderr, "%s: pcap_loop: %s\n",
2608                             program_name, pcap_geterr(pd));
2609                 }
2610                 if (RFileName == NULL) {
2611                         /*
2612                          * We're doing a live capture.  Report the capture
2613                          * statistics.
2614                          */
2615                         info(1);
2616                 }
2617                 pcap_close(pd);
2618                 if (VFileName != NULL) {
2619                         ret = get_next_file(VFile, VFileLine);
2620                         if (ret) {
2621                                 int new_dlt;
2622
2623                                 RFileName = VFileLine;
2624                                 pd = pcap_open_offline(RFileName, ebuf);
2625                                 if (pd == NULL)
2626                                         error("%s", ebuf);
2627 #ifdef HAVE_CAPSICUM
2628                                 cap_rights_init(&rights, CAP_READ);
2629                                 if (cap_rights_limit(fileno(pcap_file(pd)),
2630                                     &rights) < 0 && errno != ENOSYS) {
2631                                         error("unable to limit pcap descriptor");
2632                                 }
2633 #endif
2634                                 new_dlt = pcap_datalink(pd);
2635                                 if (new_dlt != dlt) {
2636                                         /*
2637                                          * The new file has a different
2638                                          * link-layer header type from the
2639                                          * previous one.
2640                                          */
2641                                         if (WFileName != NULL) {
2642                                                 /*
2643                                                  * We're writing raw packets
2644                                                  * that match the filter to
2645                                                  * a pcap file.  pcap files
2646                                                  * don't support multiple
2647                                                  * different link-layer
2648                                                  * header types, so we fail
2649                                                  * here.
2650                                                  */
2651                                                 error("%s: new dlt does not match original", RFileName);
2652                                         }
2653
2654                                         /*
2655                                          * We're printing the decoded packets;
2656                                          * switch to the new DLT.
2657                                          *
2658                                          * To do that, we need to change
2659                                          * the printer, change the DLT name,
2660                                          * and recompile the filter with
2661                                          * the new DLT.
2662                                          */
2663                                         dlt = new_dlt;
2664                                         ndo->ndo_if_printer = get_if_printer(dlt);
2665                                         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2666                                                 error("%s", pcap_geterr(pd));
2667                                 }
2668
2669                                 /*
2670                                  * Set the filter on the new file.
2671                                  */
2672                                 if (pcap_setfilter(pd, &fcode) < 0)
2673                                         error("%s", pcap_geterr(pd));
2674
2675                                 /*
2676                                  * Report the new file.
2677                                  */
2678                                 dlt_name = pcap_datalink_val_to_name(dlt);
2679                                 fprintf(stderr, "reading from file %s", RFileName);
2680                                 if (dlt_name == NULL) {
2681                                         fprintf(stderr, ", link-type %u", dlt);
2682                                 } else {
2683                                         fprintf(stderr, ", link-type %s (%s)",
2684                                                 dlt_name,
2685                                                 pcap_datalink_val_to_description(dlt));
2686                                 }
2687                                 fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2688                         }
2689                 }
2690         }
2691         while (ret != NULL);
2692
2693         if (count_mode && RFileName != NULL)
2694                 fprintf(stdout, "%u packet%s\n", packets_captured,
2695                         PLURAL_SUFFIX(packets_captured));
2696
2697         free(cmdbuf);
2698         pcap_freecode(&fcode);
2699         exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS);
2700 }
2701
2702 /*
2703  * Catch a signal.
2704  */
2705 static void
2706 (*setsignal (int sig, void (*func)(int)))(int)
2707 {
2708 #ifdef _WIN32
2709         return (signal(sig, func));
2710 #else
2711         struct sigaction old, new;
2712
2713         memset(&new, 0, sizeof(new));
2714         new.sa_handler = func;
2715         if ((sig == SIGCHLD)
2716 # ifdef SIGNAL_REQ_INFO
2717                 || (sig == SIGNAL_REQ_INFO)
2718 # endif
2719 # ifdef SIGNAL_FLUSH_PCAP
2720                 || (sig == SIGNAL_FLUSH_PCAP)
2721 # endif
2722                 )
2723                 new.sa_flags = SA_RESTART;
2724         if (sigaction(sig, &new, &old) < 0)
2725                 return (SIG_ERR);
2726         return (old.sa_handler);
2727 #endif
2728 }
2729
2730 /* make a clean exit on interrupts */
2731 static void
2732 cleanup(int signo _U_)
2733 {
2734 #ifdef _WIN32
2735         if (timer_handle != INVALID_HANDLE_VALUE) {
2736                 DeleteTimerQueueTimer(NULL, timer_handle, NULL);
2737                 CloseHandle(timer_handle);
2738                 timer_handle = INVALID_HANDLE_VALUE;
2739         }
2740 #else /* _WIN32 */
2741         struct itimerval timer;
2742
2743         timer.it_interval.tv_sec = 0;
2744         timer.it_interval.tv_usec = 0;
2745         timer.it_value.tv_sec = 0;
2746         timer.it_value.tv_usec = 0;
2747         setitimer(ITIMER_REAL, &timer, NULL);
2748 #endif /* _WIN32 */
2749
2750 #ifdef HAVE_PCAP_BREAKLOOP
2751         /*
2752          * We have "pcap_breakloop()"; use it, so that we do as little
2753          * as possible in the signal handler (it's probably not safe
2754          * to do anything with standard I/O streams in a signal handler -
2755          * the ANSI C standard doesn't say it is).
2756          */
2757         pcap_breakloop(pd);
2758 #else
2759         /*
2760          * We don't have "pcap_breakloop()"; this isn't safe, but
2761          * it's the best we can do.  Print the summary if we're
2762          * not reading from a savefile - i.e., if we're doing a
2763          * live capture - and exit.
2764          */
2765         if (pd != NULL && pcap_file(pd) == NULL) {
2766                 /*
2767                  * We got interrupted, so perhaps we didn't
2768                  * manage to finish a line we were printing.
2769                  * Print an extra newline, just in case.
2770                  */
2771                 putchar('\n');
2772                 (void)fflush(stdout);
2773                 info(1);
2774         }
2775         exit_tcpdump(S_SUCCESS);
2776 #endif
2777 }
2778
2779 /*
2780   On windows, we do not use a fork, so we do not care less about
2781   waiting a child processes to die
2782  */
2783 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2784 static void
2785 child_cleanup(int signo _U_)
2786 {
2787   wait(NULL);
2788 }
2789 #endif /* HAVE_FORK && HAVE_VFORK */
2790
2791 static void
2792 info(int verbose)
2793 {
2794         struct pcap_stat stats;
2795
2796         /*
2797          * Older versions of libpcap didn't set ps_ifdrop on some
2798          * platforms; initialize it to 0 to handle that.
2799          */
2800         stats.ps_ifdrop = 0;
2801         if (pcap_stats(pd, &stats) < 0) {
2802                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
2803                 infoprint = 0;
2804                 return;
2805         }
2806
2807         if (!verbose)
2808                 fprintf(stderr, "%s: ", program_name);
2809
2810         (void)fprintf(stderr, "%u packet%s captured", packets_captured,
2811             PLURAL_SUFFIX(packets_captured));
2812         if (!verbose)
2813                 fputs(", ", stderr);
2814         else
2815                 putc('\n', stderr);
2816         (void)fprintf(stderr, "%u packet%s received by filter", stats.ps_recv,
2817             PLURAL_SUFFIX(stats.ps_recv));
2818         if (!verbose)
2819                 fputs(", ", stderr);
2820         else
2821                 putc('\n', stderr);
2822         (void)fprintf(stderr, "%u packet%s dropped by kernel", stats.ps_drop,
2823             PLURAL_SUFFIX(stats.ps_drop));
2824         if (stats.ps_ifdrop != 0) {
2825                 if (!verbose)
2826                         fputs(", ", stderr);
2827                 else
2828                         putc('\n', stderr);
2829                 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
2830                     stats.ps_ifdrop, PLURAL_SUFFIX(stats.ps_ifdrop));
2831         } else
2832                 putc('\n', stderr);
2833         infoprint = 0;
2834 }
2835
2836 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2837 #ifdef HAVE_FORK
2838 #define fork_subprocess() fork()
2839 #else
2840 #define fork_subprocess() vfork()
2841 #endif
2842 static void
2843 compress_savefile(const char *filename)
2844 {
2845         pid_t child;
2846
2847         child = fork_subprocess();
2848         if (child == -1) {
2849                 fprintf(stderr,
2850                         "compress_savefile: fork failed: %s\n",
2851                         pcap_strerror(errno));
2852                 return;
2853         }
2854         if (child != 0) {
2855                 /* Parent process. */
2856                 return;
2857         }
2858
2859         /*
2860          * Child process.
2861          * Set to lowest priority so that this doesn't disturb the capture.
2862          */
2863 #ifdef NZERO
2864         setpriority(PRIO_PROCESS, 0, NZERO - 1);
2865 #else
2866         setpriority(PRIO_PROCESS, 0, 19);
2867 #endif
2868         if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
2869                 fprintf(stderr,
2870                         "compress_savefile: execlp(%s, %s) failed: %s\n",
2871                         zflag,
2872                         filename,
2873                         pcap_strerror(errno));
2874 #ifdef HAVE_FORK
2875         exit(S_ERR_HOST_PROGRAM);
2876 #else
2877         _exit(S_ERR_HOST_PROGRAM);
2878 #endif
2879 }
2880 #else  /* HAVE_FORK && HAVE_VFORK */
2881 static void
2882 compress_savefile(const char *filename)
2883 {
2884         fprintf(stderr,
2885                 "compress_savefile failed. Functionality not implemented under your system\n");
2886 }
2887 #endif /* HAVE_FORK && HAVE_VFORK */
2888
2889 static void
2890 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2891 {
2892         struct dump_info *dump_info;
2893
2894         ++packets_captured;
2895
2896         ++infodelay;
2897
2898         dump_info = (struct dump_info *)user;
2899
2900         /*
2901          * XXX - this won't force the file to rotate on the specified time
2902          * boundary, but it will rotate on the first packet received after the
2903          * specified Gflag number of seconds. Note: if a Gflag time boundary
2904          * and a Cflag size boundary coincide, the time rotation will occur
2905          * first thereby cancelling the Cflag boundary (since the file should
2906          * be 0).
2907          */
2908         if (Gflag != 0) {
2909                 /* Check if it is time to rotate */
2910                 time_t t;
2911
2912                 /* Get the current time */
2913                 if ((t = time(NULL)) == (time_t)-1) {
2914                         error("%s: can't get current_time: %s",
2915                             __func__, pcap_strerror(errno));
2916                 }
2917
2918
2919                 /* If the time is greater than the specified window, rotate */
2920                 if (t - Gflag_time >= Gflag) {
2921 #ifdef HAVE_CAPSICUM
2922                         FILE *fp;
2923                         int fd;
2924 #endif
2925
2926                         /* Update the Gflag_time */
2927                         Gflag_time = t;
2928                         /* Update Gflag_count */
2929                         Gflag_count++;
2930                         /*
2931                          * Close the current file and open a new one.
2932                          */
2933                         pcap_dump_close(dump_info->pdd);
2934
2935                         /*
2936                          * Compress the file we just closed, if the user asked for it
2937                          */
2938                         if (zflag != NULL)
2939                                 compress_savefile(dump_info->CurrentFileName);
2940
2941                         /*
2942                          * Check to see if we've exceeded the Wflag (when
2943                          * not using Cflag).
2944                          */
2945                         if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
2946                                 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
2947                                     Wflag);
2948                                 info(1);
2949                                 exit_tcpdump(S_SUCCESS);
2950                                 /* NOTREACHED */
2951                         }
2952                         if (dump_info->CurrentFileName != NULL)
2953                                 free(dump_info->CurrentFileName);
2954                         /* Allocate space for max filename + \0. */
2955                         dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2956                         if (dump_info->CurrentFileName == NULL)
2957                                 error("dump_packet_and_trunc: malloc");
2958                         /*
2959                          * Gflag was set otherwise we wouldn't be here. Reset the count
2960                          * so multiple files would end with 1,2,3 in the filename.
2961                          * The counting is handled with the -C flow after this.
2962                          */
2963                         Cflag_count = 0;
2964
2965                         /*
2966                          * This is always the first file in the Cflag
2967                          * rotation: e.g. 0
2968                          * We also don't need numbering if Cflag is not set.
2969                          */
2970                         if (Cflag != 0)
2971                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
2972                                     WflagChars);
2973                         else
2974                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
2975
2976 #ifdef HAVE_LIBCAP_NG
2977                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2978                         capng_apply(CAPNG_SELECT_BOTH);
2979 #endif /* HAVE_LIBCAP_NG */
2980 #ifdef HAVE_CAPSICUM
2981                         fd = openat(dump_info->dirfd,
2982                             dump_info->CurrentFileName,
2983                             O_CREAT | O_WRONLY | O_TRUNC, 0644);
2984                         if (fd < 0) {
2985                                 error("unable to open file %s",
2986                                     dump_info->CurrentFileName);
2987                         }
2988                         fp = fdopen(fd, "w");
2989                         if (fp == NULL) {
2990                                 error("unable to fdopen file %s",
2991                                     dump_info->CurrentFileName);
2992                         }
2993                         dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
2994 #else   /* !HAVE_CAPSICUM */
2995                         dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2996 #endif
2997 #ifdef HAVE_LIBCAP_NG
2998                         capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2999                         capng_apply(CAPNG_SELECT_BOTH);
3000 #endif /* HAVE_LIBCAP_NG */
3001                         if (dump_info->pdd == NULL)
3002                                 error("%s", pcap_geterr(pd));
3003 #ifdef HAVE_CAPSICUM
3004                         set_dumper_capsicum_rights(dump_info->pdd);
3005 #endif
3006                 }
3007         }
3008
3009         /*
3010          * XXX - this won't prevent capture files from getting
3011          * larger than Cflag - the last packet written to the
3012          * file could put it over Cflag.
3013          */
3014         if (Cflag != 0) {
3015 #ifdef HAVE_PCAP_DUMP_FTELL64
3016                 int64_t size = pcap_dump_ftell64(dump_info->pdd);
3017 #else
3018                 /*
3019                  * XXX - this only handles a Cflag value > 2^31-1 on
3020                  * LP64 platforms; to handle ILP32 (32-bit UN*X and
3021                  * Windows) or LLP64 (64-bit Windows) would require
3022                  * a version of libpcap with pcap_dump_ftell64().
3023                  */
3024                 long size = pcap_dump_ftell(dump_info->pdd);
3025 #endif
3026
3027                 if (size == -1)
3028                         error("ftell fails on output file");
3029                 if (size > Cflag) {
3030 #ifdef HAVE_CAPSICUM
3031                         FILE *fp;
3032                         int fd;
3033 #endif
3034
3035                         /*
3036                          * Close the current file and open a new one.
3037                          */
3038                         pcap_dump_close(dump_info->pdd);
3039
3040                         /*
3041                          * Compress the file we just closed, if the user
3042                          * asked for it.
3043                          */
3044                         if (zflag != NULL)
3045                                 compress_savefile(dump_info->CurrentFileName);
3046
3047                         Cflag_count++;
3048                         if (Wflag > 0) {
3049                                 if (Cflag_count >= Wflag)
3050                                         Cflag_count = 0;
3051                         }
3052                         if (dump_info->CurrentFileName != NULL)
3053                                 free(dump_info->CurrentFileName);
3054                         dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
3055                         if (dump_info->CurrentFileName == NULL)
3056                                 error("%s: malloc", __func__);
3057                         MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
3058 #ifdef HAVE_LIBCAP_NG
3059                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3060                         capng_apply(CAPNG_SELECT_BOTH);
3061 #endif /* HAVE_LIBCAP_NG */
3062 #ifdef HAVE_CAPSICUM
3063                         fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
3064                             O_CREAT | O_WRONLY | O_TRUNC, 0644);
3065                         if (fd < 0) {
3066                                 error("unable to open file %s",
3067                                     dump_info->CurrentFileName);
3068                         }
3069                         fp = fdopen(fd, "w");
3070                         if (fp == NULL) {
3071                                 error("unable to fdopen file %s",
3072                                     dump_info->CurrentFileName);
3073                         }
3074                         dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
3075 #else   /* !HAVE_CAPSICUM */
3076                         dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
3077 #endif
3078 #ifdef HAVE_LIBCAP_NG
3079                         capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3080                         capng_apply(CAPNG_SELECT_BOTH);
3081 #endif /* HAVE_LIBCAP_NG */
3082                         if (dump_info->pdd == NULL)
3083                                 error("%s", pcap_geterr(pd));
3084 #ifdef HAVE_CAPSICUM
3085                         set_dumper_capsicum_rights(dump_info->pdd);
3086 #endif
3087                 }
3088         }
3089
3090         pcap_dump((u_char *)dump_info->pdd, h, sp);
3091 #ifdef HAVE_PCAP_DUMP_FLUSH
3092         if (Uflag)
3093                 pcap_dump_flush(dump_info->pdd);
3094 #endif
3095
3096         if (dump_info->ndo != NULL)
3097                 pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3098
3099         --infodelay;
3100         if (infoprint)
3101                 info(0);
3102 }
3103
3104 static void
3105 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3106 {
3107         struct dump_info *dump_info;
3108
3109         ++packets_captured;
3110
3111         ++infodelay;
3112
3113         dump_info = (struct dump_info *)user;
3114
3115         pcap_dump((u_char *)dump_info->pdd, h, sp);
3116 #ifdef HAVE_PCAP_DUMP_FLUSH
3117         if (Uflag)
3118                 pcap_dump_flush(dump_info->pdd);
3119 #endif
3120
3121         if (dump_info->ndo != NULL)
3122                 pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3123
3124         --infodelay;
3125         if (infoprint)
3126                 info(0);
3127 }
3128
3129 static void
3130 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3131 {
3132         ++packets_captured;
3133
3134         ++infodelay;
3135
3136         if (!count_mode)
3137                 pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
3138
3139         --infodelay;
3140         if (infoprint)
3141                 info(0);
3142 }
3143
3144 #ifdef SIGNAL_REQ_INFO
3145 static void
3146 requestinfo(int signo _U_)
3147 {
3148         if (infodelay)
3149                 ++infoprint;
3150         else
3151                 info(0);
3152 }
3153 #endif
3154
3155 #ifdef SIGNAL_FLUSH_PCAP
3156 static void
3157 flushpcap(int signo _U_)
3158 {
3159         if (pdd != NULL)
3160                 pcap_dump_flush(pdd);
3161 }
3162 #endif
3163
3164 static void
3165 print_packets_captured (void)
3166 {
3167         static u_int prev_packets_captured, first = 1;
3168
3169         if (infodelay == 0 && (first || packets_captured != prev_packets_captured)) {
3170                 fprintf(stderr, "Got %u\r", packets_captured);
3171                 first = 0;
3172                 prev_packets_captured = packets_captured;
3173         }
3174 }
3175
3176 /*
3177  * Called once each second in verbose mode while dumping to file
3178  */
3179 #ifdef _WIN32
3180 static void CALLBACK verbose_stats_dump(PVOID param _U_,
3181     BOOLEAN timer_fired _U_)
3182 {
3183         print_packets_captured();
3184 }
3185 #else /* _WIN32 */
3186 static void verbose_stats_dump(int sig _U_)
3187 {
3188         print_packets_captured();
3189 }
3190 #endif /* _WIN32 */
3191
3192 DIAG_OFF_DEPRECATION
3193 static void
3194 print_version(FILE *f)
3195 {
3196 #ifndef HAVE_PCAP_LIB_VERSION
3197   #ifdef HAVE_PCAP_VERSION
3198         extern char pcap_version[];
3199   #else /* HAVE_PCAP_VERSION */
3200         static char pcap_version[] = "unknown";
3201   #endif /* HAVE_PCAP_VERSION */
3202 #endif /* HAVE_PCAP_LIB_VERSION */
3203         const char *smi_version_string;
3204
3205         (void)fprintf(f, "%s version " PACKAGE_VERSION "\n", program_name);
3206 #ifdef HAVE_PCAP_LIB_VERSION
3207         (void)fprintf(f, "%s\n", pcap_lib_version());
3208 #else /* HAVE_PCAP_LIB_VERSION */
3209         (void)fprintf(f, "libpcap version %s\n", pcap_version);
3210 #endif /* HAVE_PCAP_LIB_VERSION */
3211
3212 #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
3213         (void)fprintf (f, "%s\n", SSLeay_version(SSLEAY_VERSION));
3214 #endif
3215
3216         smi_version_string = nd_smi_version_string();
3217         if (smi_version_string != NULL)
3218                 (void)fprintf (f, "SMI-library: %s\n", smi_version_string);
3219
3220 #if defined(__SANITIZE_ADDRESS__)
3221         (void)fprintf (f, "Compiled with AddressSanitizer/GCC.\n");
3222 #elif defined(__has_feature)
3223 #  if __has_feature(address_sanitizer)
3224         (void)fprintf (f, "Compiled with AddressSanitizer/Clang.\n");
3225 #  elif __has_feature(memory_sanitizer)
3226         (void)fprintf (f, "Compiled with MemorySanitizer/Clang.\n");
3227 #  endif
3228 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
3229 }
3230 DIAG_ON_DEPRECATION
3231
3232 static void
3233 print_usage(FILE *f)
3234 {
3235         print_version(f);
3236         (void)fprintf(f,
3237 "Usage: %s [-Abd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ] [--count]\n", program_name);
3238         (void)fprintf(f,
3239 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
3240         (void)fprintf(f,
3241 "\t\t[ -i interface ]" IMMEDIATE_MODE_USAGE j_FLAG_USAGE "\n");
3242 #ifdef HAVE_PCAP_FINDALLDEVS_EX
3243         (void)fprintf(f,
3244 "\t\t" LIST_REMOTE_INTERFACES_USAGE "\n");
3245 #endif
3246 #ifdef USE_LIBSMI
3247         (void)fprintf(f,
3248 "\t\t" m_FLAG_USAGE "\n");
3249 #endif
3250         (void)fprintf(f,
3251 "\t\t[ -M secret ] [ --number ] [ --print ]" Q_FLAG_USAGE "\n");
3252         (void)fprintf(f,
3253 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ --version ]\n");
3254         (void)fprintf(f,
3255 "\t\t[ -V file ] [ -w file ] [ -W filecount ] [ -y datalinktype ]\n");
3256 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
3257         (void)fprintf(f,
3258 "\t\t[ --time-stamp-precision precision ] [ --micro ] [ --nano ]\n");
3259 #endif
3260         (void)fprintf(f,
3261 "\t\t[ -z postrotate-command ] [ -Z user ] [ expression ]\n");
3262 }