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         tzset();
1568
1569         while (
1570             (op = getopt_long(argc, argv, SHORTOPTS, longopts, NULL)) != -1)
1571                 switch (op) {
1572
1573                 case 'a':
1574                         /* compatibility for old -a */
1575                         break;
1576
1577                 case 'A':
1578                         ++ndo->ndo_Aflag;
1579                         break;
1580
1581                 case 'b':
1582                         ++ndo->ndo_bflag;
1583                         break;
1584
1585 #if defined(HAVE_PCAP_CREATE) || defined(_WIN32)
1586                 case 'B':
1587                         Bflag = atoi(optarg)*1024;
1588                         if (Bflag <= 0)
1589                                 error("invalid packet buffer size %s", optarg);
1590                         break;
1591 #endif /* defined(HAVE_PCAP_CREATE) || defined(_WIN32) */
1592
1593                 case 'c':
1594                         cnt = atoi(optarg);
1595                         if (cnt <= 0)
1596                                 error("invalid packet count %s", optarg);
1597                         break;
1598
1599                 case 'C':
1600                         errno = 0;
1601 #ifdef HAVE_PCAP_DUMP_FTELL64
1602                         Cflag = strtoint64_t(optarg, &endp, 10);
1603 #else
1604                         Cflag = strtol(optarg, &endp, 10);
1605 #endif
1606                         if (endp == optarg || *endp != '\0' || errno != 0
1607                             || Cflag <= 0)
1608                                 error("invalid file size %s", optarg);
1609                         /*
1610                          * Will multiplying it by 1000000 overflow?
1611                          */
1612 #ifdef HAVE_PCAP_DUMP_FTELL64
1613                         if (Cflag > INT64_T_CONSTANT(0x7fffffffffffffff) / 1000000)
1614 #else
1615                         if (Cflag > LONG_MAX / 1000000)
1616 #endif
1617                                 error("file size %s is too large", optarg);
1618                         Cflag *= 1000000;
1619                         break;
1620
1621                 case 'd':
1622                         ++dflag;
1623                         break;
1624
1625 #ifdef HAVE_PCAP_FINDALLDEVS
1626                 case 'D':
1627                         Dflag++;
1628                         break;
1629 #endif
1630
1631 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1632                 case OPTION_LIST_REMOTE_INTERFACES:
1633                         remote_interfaces_source = optarg;
1634                         break;
1635 #endif
1636
1637                 case 'L':
1638                         Lflag++;
1639                         break;
1640
1641                 case 'e':
1642                         ++ndo->ndo_eflag;
1643                         break;
1644
1645                 case 'E':
1646 #ifndef HAVE_LIBCRYPTO
1647                         warning("crypto code not compiled in");
1648 #endif
1649                         ndo->ndo_espsecret = optarg;
1650                         break;
1651
1652                 case 'f':
1653                         ++ndo->ndo_fflag;
1654                         break;
1655
1656                 case 'F':
1657                         infile = optarg;
1658                         break;
1659
1660                 case 'G':
1661                         Gflag = atoi(optarg);
1662                         if (Gflag < 0)
1663                                 error("invalid number of seconds %s", optarg);
1664
1665                         /* We will create one file initially. */
1666                         Gflag_count = 0;
1667
1668                         /* Grab the current time for rotation use. */
1669                         if ((Gflag_time = time(NULL)) == (time_t)-1) {
1670                                 error("%s: can't get current time: %s",
1671                                     __func__, pcap_strerror(errno));
1672                         }
1673                         break;
1674
1675                 case 'h':
1676                         print_usage(stdout);
1677                         exit_tcpdump(S_SUCCESS);
1678                         break;
1679
1680                 case 'H':
1681                         ++ndo->ndo_Hflag;
1682                         break;
1683
1684                 case 'i':
1685                         device = optarg;
1686                         break;
1687
1688 #ifdef HAVE_PCAP_CREATE
1689                 case 'I':
1690                         ++Iflag;
1691                         break;
1692 #endif /* HAVE_PCAP_CREATE */
1693
1694 #ifdef HAVE_PCAP_SET_TSTAMP_TYPE
1695                 case 'j':
1696                         jflag = pcap_tstamp_type_name_to_val(optarg);
1697                         if (jflag < 0)
1698                                 error("invalid time stamp type %s", optarg);
1699                         break;
1700
1701                 case 'J':
1702                         Jflag++;
1703                         break;
1704 #endif
1705
1706                 case 'l':
1707 #ifdef _WIN32
1708                         /*
1709                          * _IOLBF is the same as _IOFBF in Microsoft's C
1710                          * libraries; the only alternative they offer
1711                          * is _IONBF.
1712                          *
1713                          * XXX - this should really be checking for MSVC++,
1714                          * not _WIN32, if, for example, MinGW has its own
1715                          * C library that is more UNIX-compatible.
1716                          */
1717                         setvbuf(stdout, NULL, _IONBF, 0);
1718 #else /* _WIN32 */
1719 #ifdef HAVE_SETLINEBUF
1720                         setlinebuf(stdout);
1721 #else
1722                         setvbuf(stdout, NULL, _IOLBF, 0);
1723 #endif
1724 #endif /* _WIN32 */
1725                         lflag = 1;
1726                         break;
1727
1728                 case 'K':
1729                         ++ndo->ndo_Kflag;
1730                         break;
1731
1732                 case 'm':
1733                         if (nd_have_smi_support()) {
1734                                 if (nd_load_smi_module(optarg, ebuf, sizeof(ebuf)) == -1)
1735                                         error("%s", ebuf);
1736                         } else {
1737                                 (void)fprintf(stderr, "%s: ignoring option `-m %s' ",
1738                                               program_name, optarg);
1739                                 (void)fprintf(stderr, "(no libsmi support)\n");
1740                         }
1741                         break;
1742
1743                 case 'M':
1744                         /* TCP-MD5 shared secret */
1745 #ifndef HAVE_LIBCRYPTO
1746                         warning("crypto code not compiled in");
1747 #endif
1748                         ndo->ndo_sigsecret = optarg;
1749                         break;
1750
1751                 case 'n':
1752                         ++ndo->ndo_nflag;
1753                         break;
1754
1755                 case 'N':
1756                         ++ndo->ndo_Nflag;
1757                         break;
1758
1759                 case 'O':
1760                         Oflag = 0;
1761                         break;
1762
1763                 case 'p':
1764                         ++pflag;
1765                         break;
1766
1767                 case 'q':
1768                         ++ndo->ndo_qflag;
1769                         ++ndo->ndo_suppress_default_print;
1770                         break;
1771
1772 #ifdef HAVE_PCAP_SETDIRECTION
1773                 case 'Q':
1774                         if (ascii_strcasecmp(optarg, "in") == 0)
1775                                 Qflag = PCAP_D_IN;
1776                         else if (ascii_strcasecmp(optarg, "out") == 0)
1777                                 Qflag = PCAP_D_OUT;
1778                         else if (ascii_strcasecmp(optarg, "inout") == 0)
1779                                 Qflag = PCAP_D_INOUT;
1780                         else
1781                                 error("unknown capture direction `%s'", optarg);
1782                         break;
1783 #endif /* HAVE_PCAP_SETDIRECTION */
1784
1785                 case 'r':
1786                         RFileName = optarg;
1787                         break;
1788
1789                 case 's':
1790                         ndo->ndo_snaplen = (int)strtol(optarg, &end, 0);
1791                         if (optarg == end || *end != '\0'
1792                             || ndo->ndo_snaplen < 0 || ndo->ndo_snaplen > MAXIMUM_SNAPLEN)
1793                                 error("invalid snaplen %s (must be >= 0 and <= %d)",
1794                                       optarg, MAXIMUM_SNAPLEN);
1795                         break;
1796
1797                 case 'S':
1798                         ++ndo->ndo_Sflag;
1799                         break;
1800
1801                 case 't':
1802                         ++ndo->ndo_tflag;
1803                         break;
1804
1805                 case 'T':
1806                         if (ascii_strcasecmp(optarg, "vat") == 0)
1807                                 ndo->ndo_packettype = PT_VAT;
1808                         else if (ascii_strcasecmp(optarg, "wb") == 0)
1809                                 ndo->ndo_packettype = PT_WB;
1810                         else if (ascii_strcasecmp(optarg, "rpc") == 0)
1811                                 ndo->ndo_packettype = PT_RPC;
1812                         else if (ascii_strcasecmp(optarg, "rtp") == 0)
1813                                 ndo->ndo_packettype = PT_RTP;
1814                         else if (ascii_strcasecmp(optarg, "rtcp") == 0)
1815                                 ndo->ndo_packettype = PT_RTCP;
1816                         else if (ascii_strcasecmp(optarg, "snmp") == 0)
1817                                 ndo->ndo_packettype = PT_SNMP;
1818                         else if (ascii_strcasecmp(optarg, "cnfp") == 0)
1819                                 ndo->ndo_packettype = PT_CNFP;
1820                         else if (ascii_strcasecmp(optarg, "tftp") == 0)
1821                                 ndo->ndo_packettype = PT_TFTP;
1822                         else if (ascii_strcasecmp(optarg, "aodv") == 0)
1823                                 ndo->ndo_packettype = PT_AODV;
1824                         else if (ascii_strcasecmp(optarg, "carp") == 0)
1825                                 ndo->ndo_packettype = PT_CARP;
1826                         else if (ascii_strcasecmp(optarg, "radius") == 0)
1827                                 ndo->ndo_packettype = PT_RADIUS;
1828                         else if (ascii_strcasecmp(optarg, "zmtp1") == 0)
1829                                 ndo->ndo_packettype = PT_ZMTP1;
1830                         else if (ascii_strcasecmp(optarg, "vxlan") == 0)
1831                                 ndo->ndo_packettype = PT_VXLAN;
1832                         else if (ascii_strcasecmp(optarg, "pgm") == 0)
1833                                 ndo->ndo_packettype = PT_PGM;
1834                         else if (ascii_strcasecmp(optarg, "pgm_zmtp1") == 0)
1835                                 ndo->ndo_packettype = PT_PGM_ZMTP1;
1836                         else if (ascii_strcasecmp(optarg, "lmp") == 0)
1837                                 ndo->ndo_packettype = PT_LMP;
1838                         else if (ascii_strcasecmp(optarg, "resp") == 0)
1839                                 ndo->ndo_packettype = PT_RESP;
1840                         else if (ascii_strcasecmp(optarg, "ptp") == 0)
1841                                 ndo->ndo_packettype = PT_PTP;
1842                         else if (ascii_strcasecmp(optarg, "someip") == 0)
1843                                 ndo->ndo_packettype = PT_SOMEIP;
1844                         else if (ascii_strcasecmp(optarg, "domain") == 0)
1845                                 ndo->ndo_packettype = PT_DOMAIN;
1846                         else
1847                                 error("unknown packet type `%s'", optarg);
1848                         break;
1849
1850                 case 'u':
1851                         ++ndo->ndo_uflag;
1852                         break;
1853
1854 #ifdef HAVE_PCAP_DUMP_FLUSH
1855                 case 'U':
1856                         ++Uflag;
1857                         break;
1858 #endif
1859
1860                 case 'v':
1861                         ++ndo->ndo_vflag;
1862                         break;
1863
1864                 case 'V':
1865                         VFileName = optarg;
1866                         break;
1867
1868                 case 'w':
1869                         WFileName = optarg;
1870                         break;
1871
1872                 case 'W':
1873                         Wflag = atoi(optarg);
1874                         if (Wflag <= 0)
1875                                 error("invalid number of output files %s", optarg);
1876                         WflagChars = getWflagChars(Wflag);
1877                         break;
1878
1879                 case 'x':
1880                         ++ndo->ndo_xflag;
1881                         ++ndo->ndo_suppress_default_print;
1882                         break;
1883
1884                 case 'X':
1885                         ++ndo->ndo_Xflag;
1886                         ++ndo->ndo_suppress_default_print;
1887                         break;
1888
1889                 case 'y':
1890                         yflag_dlt_name = optarg;
1891                         yflag_dlt =
1892                                 pcap_datalink_name_to_val(yflag_dlt_name);
1893                         if (yflag_dlt < 0)
1894                                 error("invalid data link type %s", yflag_dlt_name);
1895                         break;
1896
1897 #ifdef HAVE_PCAP_SET_PARSER_DEBUG
1898                 case 'Y':
1899                         {
1900                         /* Undocumented flag */
1901                         pcap_set_parser_debug(1);
1902                         }
1903                         break;
1904 #endif
1905                 case 'z':
1906                         zflag = optarg;
1907                         break;
1908
1909                 case 'Z':
1910                         username = optarg;
1911                         break;
1912
1913                 case '#':
1914                         ndo->ndo_packet_number = 1;
1915                         break;
1916
1917                 case OPTION_VERSION:
1918                         print_version(stdout);
1919                         exit_tcpdump(S_SUCCESS);
1920                         break;
1921
1922 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1923                 case OPTION_TSTAMP_PRECISION:
1924                         ndo->ndo_tstamp_precision = tstamp_precision_from_string(optarg);
1925                         if (ndo->ndo_tstamp_precision < 0)
1926                                 error("unsupported time stamp precision");
1927                         break;
1928 #endif
1929
1930 #ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
1931                 case OPTION_IMMEDIATE_MODE:
1932                         immediate_mode = 1;
1933                         break;
1934 #endif
1935
1936                 case OPTION_PRINT:
1937                         print = 1;
1938                         break;
1939
1940 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
1941                 case OPTION_TSTAMP_MICRO:
1942                         ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
1943                         break;
1944
1945                 case OPTION_TSTAMP_NANO:
1946                         ndo->ndo_tstamp_precision = PCAP_TSTAMP_PRECISION_NANO;
1947                         break;
1948 #endif
1949
1950                 case OPTION_FP_TYPE:
1951                         /*
1952                          * Print out the type of floating-point arithmetic
1953                          * we're doing; it's probably IEEE, unless somebody
1954                          * tries to run this on a VAX, but the precision
1955                          * may differ (e.g., it might be 32-bit, 64-bit,
1956                          * or 80-bit).
1957                          */
1958                         float_type_check(0x4e93312d);
1959                         return 0;
1960
1961                 case OPTION_COUNT:
1962                         count_mode = 1;
1963                         break;
1964
1965                 default:
1966                         print_usage(stderr);
1967                         exit_tcpdump(S_ERR_HOST_PROGRAM);
1968                         /* NOTREACHED */
1969                 }
1970
1971 #ifdef HAVE_PCAP_FINDALLDEVS
1972         if (Dflag)
1973                 show_devices_and_exit();
1974 #endif
1975 #ifdef HAVE_PCAP_FINDALLDEVS_EX
1976         if (remote_interfaces_source != NULL)
1977                 show_remote_devices_and_exit();
1978 #endif
1979
1980 #if defined(DLT_LINUX_SLL2) && defined(HAVE_PCAP_SET_DATALINK)
1981 /* Set default linktype DLT_LINUX_SLL2 when capturing on the "any" device */
1982                 if (device != NULL &&
1983                     strncmp (device, "any", strlen("any")) == 0
1984                     && yflag_dlt == -1)
1985                         yflag_dlt = DLT_LINUX_SLL2;
1986 #endif
1987
1988         switch (ndo->ndo_tflag) {
1989
1990         case 0: /* Default */
1991         case 1: /* No time stamp */
1992         case 2: /* Unix timeval style */
1993         case 3: /* Microseconds/nanoseconds since previous packet */
1994         case 4: /* Date + Default */
1995         case 5: /* Microseconds/nanoseconds since first packet */
1996                 break;
1997
1998         default: /* Not supported */
1999                 error("only -t, -tt, -ttt, -tttt and -ttttt are supported");
2000                 break;
2001         }
2002
2003         if (ndo->ndo_fflag != 0 && (VFileName != NULL || RFileName != NULL))
2004                 error("-f can not be used with -V or -r");
2005
2006         if (VFileName != NULL && RFileName != NULL)
2007                 error("-V and -r are mutually exclusive.");
2008
2009         /*
2010          * If we're printing dissected packets to the standard output,
2011          * and either the standard output is a terminal or we're doing
2012          * "line" buffering, set the capture timeout to .1 second rather
2013          * than 1 second, as the user's probably expecting to see packets
2014          * pop up immediately shortly after they arrive.
2015          *
2016          * XXX - would there be some value appropriate for all cases,
2017          * based on, say, the buffer size and packet input rate?
2018          */
2019         if ((WFileName == NULL || print) && (isatty(1) || lflag))
2020                 timeout = 100;
2021
2022 #ifdef WITH_CHROOT
2023         /* if run as root, prepare for chrooting */
2024         if (getuid() == 0 || geteuid() == 0) {
2025                 /* future extensibility for cmd-line arguments */
2026                 if (!chroot_dir)
2027                         chroot_dir = WITH_CHROOT;
2028         }
2029 #endif
2030
2031 #ifdef WITH_USER
2032         /* if run as root, prepare for dropping root privileges */
2033         if (getuid() == 0 || geteuid() == 0) {
2034                 /* Run with '-Z root' to restore old behaviour */
2035                 if (!username)
2036                         username = WITH_USER;
2037         }
2038 #endif
2039
2040         if (RFileName != NULL || VFileName != NULL) {
2041                 /*
2042                  * If RFileName is non-null, it's the pathname of a
2043                  * savefile to read.  If VFileName is non-null, it's
2044                  * the pathname of a file containing a list of pathnames
2045                  * (one per line) of savefiles to read.
2046                  *
2047                  * In either case, we're reading a savefile, not doing
2048                  * a live capture.
2049                  */
2050 #ifndef _WIN32
2051                 /*
2052                  * We don't need network access, so relinquish any set-UID
2053                  * or set-GID privileges we have (if any).
2054                  *
2055                  * We do *not* want set-UID privileges when opening a
2056                  * trace file, as that might let the user read other
2057                  * people's trace files (especially if we're set-UID
2058                  * root).
2059                  */
2060                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0 )
2061                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
2062 #endif /* _WIN32 */
2063                 if (VFileName != NULL) {
2064                         if (VFileName[0] == '-' && VFileName[1] == '\0')
2065                                 VFile = stdin;
2066                         else
2067                                 VFile = fopen(VFileName, "r");
2068
2069                         if (VFile == NULL)
2070                                 error("Unable to open file: %s\n", pcap_strerror(errno));
2071
2072                         ret = get_next_file(VFile, VFileLine);
2073                         if (!ret)
2074                                 error("Nothing in %s\n", VFileName);
2075                         RFileName = VFileLine;
2076                 }
2077
2078 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
2079                 pd = pcap_open_offline_with_tstamp_precision(RFileName,
2080                     ndo->ndo_tstamp_precision, ebuf);
2081 #else
2082                 pd = pcap_open_offline(RFileName, ebuf);
2083 #endif
2084
2085                 if (pd == NULL)
2086                         error("%s", ebuf);
2087 #ifdef HAVE_CAPSICUM
2088                 cap_rights_init(&rights, CAP_READ);
2089                 if (cap_rights_limit(fileno(pcap_file(pd)), &rights) < 0 &&
2090                     errno != ENOSYS) {
2091                         error("unable to limit pcap descriptor");
2092                 }
2093 #endif
2094                 dlt = pcap_datalink(pd);
2095                 dlt_name = pcap_datalink_val_to_name(dlt);
2096                 fprintf(stderr, "reading from file %s", RFileName);
2097                 if (dlt_name == NULL) {
2098                         fprintf(stderr, ", link-type %u", dlt);
2099                 } else {
2100                         fprintf(stderr, ", link-type %s (%s)", dlt_name,
2101                                 pcap_datalink_val_to_description(dlt));
2102                 }
2103                 fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2104 #ifdef DLT_LINUX_SLL2
2105                 if (dlt == DLT_LINUX_SLL2)
2106                         fprintf(stderr, "Warning: interface names might be incorrect\n");
2107 #endif
2108         } else if (dflag && !device) {
2109                 int dump_dlt = DLT_EN10MB;
2110                 /*
2111                  * We're dumping the compiled code without an explicit
2112                  * device specification.  (If a device is specified, we
2113                  * definitely want to open it to use the DLT of that device.)
2114                  * Either default to DLT_EN10MB with a warning, or use
2115                  * the user-specified value if supplied.
2116                  */
2117                 /*
2118                  * If no snapshot length was specified, or a length of 0 was
2119                  * specified, default to 256KB.
2120                  */
2121                 if (ndo->ndo_snaplen == 0)
2122                         ndo->ndo_snaplen = MAXIMUM_SNAPLEN;
2123                 /*
2124                  * If a DLT was specified with the -y flag, use that instead.
2125                  */
2126                 if (yflag_dlt != -1)
2127                         dump_dlt = yflag_dlt;
2128                 else
2129                         fprintf(stderr, "Warning: assuming Ethernet\n");
2130                 pd = pcap_open_dead(dump_dlt, ndo->ndo_snaplen);
2131         } else {
2132                 /*
2133                  * We're doing a live capture.
2134                  */
2135                 if (device == NULL) {
2136                         /*
2137                          * No interface was specified.  Pick one.
2138                          */
2139 #ifdef HAVE_PCAP_FINDALLDEVS
2140                         /*
2141                          * Find the list of interfaces, and pick
2142                          * the first interface.
2143                          */
2144                         if (pcap_findalldevs(&devlist, ebuf) == -1)
2145                                 error("%s", ebuf);
2146                         if (devlist == NULL)
2147                                 error("no interfaces available for capture");
2148                         device = strdup(devlist->name);
2149                         pcap_freealldevs(devlist);
2150 #else /* HAVE_PCAP_FINDALLDEVS */
2151                         /*
2152                          * Use whatever interface pcap_lookupdev()
2153                          * chooses.
2154                          */
2155                         device = pcap_lookupdev(ebuf);
2156                         if (device == NULL)
2157                                 error("%s", ebuf);
2158 #endif
2159                 }
2160
2161                 /*
2162                  * Try to open the interface with the specified name.
2163                  */
2164                 pd = open_interface(device, ndo, ebuf);
2165                 if (pd == NULL) {
2166                         /*
2167                          * That failed.  If we can get a list of
2168                          * interfaces, and the interface name
2169                          * is purely numeric, try to use it as
2170                          * a 1-based index in the list of
2171                          * interfaces.
2172                          */
2173 #ifdef HAVE_PCAP_FINDALLDEVS
2174                         devnum = parse_interface_number(device);
2175                         if (devnum == -1) {
2176                                 /*
2177                                  * It's not a number; just report
2178                                  * the open error and fail.
2179                                  */
2180                                 error("%s", ebuf);
2181                         }
2182
2183                         /*
2184                          * OK, it's a number; try to find the
2185                          * interface with that index, and try
2186                          * to open it.
2187                          *
2188                          * find_interface_by_number() exits if it
2189                          * couldn't be found.
2190                          */
2191                         device = find_interface_by_number(device, devnum);
2192                         pd = open_interface(device, ndo, ebuf);
2193                         if (pd == NULL)
2194                                 error("%s", ebuf);
2195 #else /* HAVE_PCAP_FINDALLDEVS */
2196                         /*
2197                          * We can't get a list of interfaces; just
2198                          * fail.
2199                          */
2200                         error("%s", ebuf);
2201 #endif /* HAVE_PCAP_FINDALLDEVS */
2202                 }
2203
2204                 /*
2205                  * Let user own process after capture device has
2206                  * been opened.
2207                  */
2208 #ifndef _WIN32
2209                 if (setgid(getgid()) != 0 || setuid(getuid()) != 0)
2210                         fprintf(stderr, "Warning: setgid/setuid failed !\n");
2211 #endif /* _WIN32 */
2212 #if !defined(HAVE_PCAP_CREATE) && defined(_WIN32)
2213                 if(Bflag != 0)
2214                         if(pcap_setbuff(pd, Bflag)==-1){
2215                                 error("%s", pcap_geterr(pd));
2216                         }
2217 #endif /* !defined(HAVE_PCAP_CREATE) && defined(_WIN32) */
2218                 if (Lflag)
2219                         show_dlts_and_exit(pd, device);
2220                 if (yflag_dlt >= 0) {
2221 #ifdef HAVE_PCAP_SET_DATALINK
2222                         if (pcap_set_datalink(pd, yflag_dlt) < 0)
2223                                 error("%s", pcap_geterr(pd));
2224 #else
2225                         /*
2226                          * We don't actually support changing the
2227                          * data link type, so we only let them
2228                          * set it to what it already is.
2229                          */
2230                         if (yflag_dlt != pcap_datalink(pd)) {
2231                                 error("%s is not one of the DLTs supported by this device\n",
2232                                       yflag_dlt_name);
2233                         }
2234 #endif
2235                         (void)fprintf(stderr, "%s: data link type %s\n",
2236                                       program_name,
2237                                       pcap_datalink_val_to_name(yflag_dlt));
2238                         (void)fflush(stderr);
2239                 }
2240                 i = pcap_snapshot(pd);
2241                 if (ndo->ndo_snaplen < i) {
2242                         if (ndo->ndo_snaplen != 0)
2243                                 warning("snaplen raised from %d to %d", ndo->ndo_snaplen, i);
2244                         ndo->ndo_snaplen = i;
2245                 } else if (ndo->ndo_snaplen > i) {
2246                         warning("snaplen lowered from %d to %d", ndo->ndo_snaplen, i);
2247                         ndo->ndo_snaplen = i;
2248                 }
2249                 if(ndo->ndo_fflag != 0) {
2250                         if (pcap_lookupnet(device, &localnet, &netmask, ebuf) < 0) {
2251                                 warning("foreign (-f) flag used but: %s", ebuf);
2252                         }
2253                 }
2254
2255         }
2256         if (infile)
2257                 cmdbuf = read_infile(infile);
2258         else
2259                 cmdbuf = copy_argv(&argv[optind]);
2260
2261 #ifdef HAVE_PCAP_SET_OPTIMIZER_DEBUG
2262         pcap_set_optimizer_debug(dflag);
2263 #endif
2264         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2265                 error("%s", pcap_geterr(pd));
2266         if (dflag) {
2267                 bpf_dump(&fcode, dflag);
2268                 pcap_close(pd);
2269                 free(cmdbuf);
2270                 pcap_freecode(&fcode);
2271                 exit_tcpdump(S_SUCCESS);
2272         }
2273
2274 #ifdef HAVE_CASPER
2275         if (!ndo->ndo_nflag)
2276                 capdns = capdns_setup();
2277 #endif  /* HAVE_CASPER */
2278
2279         init_print(ndo, localnet, netmask);
2280
2281 #ifndef _WIN32
2282         (void)setsignal(SIGPIPE, cleanup);
2283         (void)setsignal(SIGTERM, cleanup);
2284 #endif /* _WIN32 */
2285         (void)setsignal(SIGINT, cleanup);
2286 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2287         (void)setsignal(SIGCHLD, child_cleanup);
2288 #endif
2289         /* Cooperate with nohup(1) */
2290 #ifndef _WIN32
2291         if ((oldhandler = setsignal(SIGHUP, cleanup)) != SIG_DFL)
2292                 (void)setsignal(SIGHUP, oldhandler);
2293 #endif /* _WIN32 */
2294
2295 #ifndef _WIN32
2296         /*
2297          * If a user name was specified with "-Z", attempt to switch to
2298          * that user's UID.  This would probably be used with sudo,
2299          * to allow tcpdump to be run in a special restricted
2300          * account (if you just want to allow users to open capture
2301          * devices, and can't just give users that permission,
2302          * you'd make tcpdump set-UID or set-GID).
2303          *
2304          * Tcpdump doesn't necessarily write only to one savefile;
2305          * the general only way to allow a -Z instance to write to
2306          * savefiles as the user under whose UID it's run, rather
2307          * than as the user specified with -Z, would thus be to switch
2308          * to the original user ID before opening a capture file and
2309          * then switch back to the -Z user ID after opening the savefile.
2310          * Switching to the -Z user ID only after opening the first
2311          * savefile doesn't handle the general case.
2312          */
2313
2314         if (getuid() == 0 || geteuid() == 0) {
2315 #ifdef HAVE_LIBCAP_NG
2316                 /* Initialize capng */
2317                 capng_clear(CAPNG_SELECT_BOTH);
2318                 if (username) {
2319 DIAG_OFF_ASSIGN_ENUM
2320                         capng_updatev(
2321                                 CAPNG_ADD,
2322                                 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2323                                 CAP_SETUID,
2324                                 CAP_SETGID,
2325                                 -1);
2326 DIAG_ON_ASSIGN_ENUM
2327                 }
2328                 if (chroot_dir) {
2329 DIAG_OFF_ASSIGN_ENUM
2330                         capng_update(
2331                                 CAPNG_ADD,
2332                                 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2333                                 CAP_SYS_CHROOT
2334                                 );
2335 DIAG_ON_ASSIGN_ENUM
2336                 }
2337
2338                 if (WFileName) {
2339 DIAG_OFF_ASSIGN_ENUM
2340                         capng_update(
2341                                 CAPNG_ADD,
2342                                 CAPNG_PERMITTED | CAPNG_EFFECTIVE,
2343                                 CAP_DAC_OVERRIDE
2344                                 );
2345 DIAG_ON_ASSIGN_ENUM
2346                 }
2347                 capng_apply(CAPNG_SELECT_BOTH);
2348 #endif /* HAVE_LIBCAP_NG */
2349                 if (username || chroot_dir)
2350                         droproot(username, chroot_dir);
2351
2352         }
2353 #endif /* _WIN32 */
2354
2355         if (pcap_setfilter(pd, &fcode) < 0)
2356                 error("%s", pcap_geterr(pd));
2357 #ifdef HAVE_CAPSICUM
2358         if (RFileName == NULL && VFileName == NULL && pcap_fileno(pd) != -1) {
2359                 static const unsigned long cmds[] = { BIOCGSTATS, BIOCROTZBUF };
2360
2361                 /*
2362                  * The various libpcap devices use a combination of
2363                  * read (bpf), ioctl (bpf, netmap), poll (netmap)
2364                  * so we add the relevant access rights.
2365                  */
2366                 cap_rights_init(&rights, CAP_IOCTL, CAP_READ, CAP_EVENT);
2367                 if (cap_rights_limit(pcap_fileno(pd), &rights) < 0 &&
2368                     errno != ENOSYS) {
2369                         error("unable to limit pcap descriptor");
2370                 }
2371                 if (cap_ioctls_limit(pcap_fileno(pd), cmds,
2372                     sizeof(cmds) / sizeof(cmds[0])) < 0 && errno != ENOSYS) {
2373                         error("unable to limit ioctls on pcap descriptor");
2374                 }
2375         }
2376 #endif
2377         if (WFileName) {
2378                 /* Do not exceed the default PATH_MAX for files. */
2379                 dumpinfo.CurrentFileName = (char *)malloc(PATH_MAX + 1);
2380
2381                 if (dumpinfo.CurrentFileName == NULL)
2382                         error("malloc of dumpinfo.CurrentFileName");
2383
2384                 /* We do not need numbering for dumpfiles if Cflag isn't set. */
2385                 if (Cflag != 0)
2386                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, WflagChars);
2387                 else
2388                   MakeFilename(dumpinfo.CurrentFileName, WFileName, 0, 0);
2389
2390                 pdd = pcap_dump_open(pd, dumpinfo.CurrentFileName);
2391 #ifdef HAVE_LIBCAP_NG
2392                 /* Give up CAP_DAC_OVERRIDE capability.
2393                  * Only allow it to be restored if the -C or -G flag have been
2394                  * set since we may need to create more files later on.
2395                  */
2396                 capng_update(
2397                         CAPNG_DROP,
2398                         (Cflag || Gflag ? 0 : CAPNG_PERMITTED)
2399                                 | CAPNG_EFFECTIVE,
2400                         CAP_DAC_OVERRIDE
2401                         );
2402                 capng_apply(CAPNG_SELECT_BOTH);
2403 #endif /* HAVE_LIBCAP_NG */
2404                 if (pdd == NULL)
2405                         error("%s", pcap_geterr(pd));
2406 #ifdef HAVE_CAPSICUM
2407                 set_dumper_capsicum_rights(pdd);
2408 #endif
2409                 if (Cflag != 0 || Gflag != 0) {
2410 #ifdef HAVE_CAPSICUM
2411                         /*
2412                          * basename() and dirname() may modify their input buffer
2413                          * and they do since FreeBSD 12.0, but they didn't before.
2414                          * Hence use the return value only, but always assume the
2415                          * input buffer has been modified and would need to be
2416                          * reset before the next use.
2417                          */
2418                         char *WFileName_copy;
2419
2420                         if ((WFileName_copy = strdup(WFileName)) == NULL) {
2421                                 error("Unable to allocate memory for file %s",
2422                                     WFileName);
2423                         }
2424                         DIAG_OFF_C11_EXTENSIONS
2425                         dumpinfo.WFileName = strdup(basename(WFileName_copy));
2426                         DIAG_ON_C11_EXTENSIONS
2427                         if (dumpinfo.WFileName == NULL) {
2428                                 error("Unable to allocate memory for file %s",
2429                                     WFileName);
2430                         }
2431                         free(WFileName_copy);
2432
2433                         if ((WFileName_copy = strdup(WFileName)) == NULL) {
2434                                 error("Unable to allocate memory for file %s",
2435                                     WFileName);
2436                         }
2437                         DIAG_OFF_C11_EXTENSIONS
2438                         char *WFileName_dirname = dirname(WFileName_copy);
2439                         DIAG_ON_C11_EXTENSIONS
2440                         dumpinfo.dirfd = open(WFileName_dirname,
2441                             O_DIRECTORY | O_RDONLY);
2442                         if (dumpinfo.dirfd < 0) {
2443                                 error("unable to open directory %s",
2444                                     WFileName_dirname);
2445                         }
2446                         free(WFileName_dirname);
2447                         free(WFileName_copy);
2448
2449                         cap_rights_init(&rights, CAP_CREATE, CAP_FCNTL,
2450                             CAP_FTRUNCATE, CAP_LOOKUP, CAP_SEEK, CAP_WRITE);
2451                         if (cap_rights_limit(dumpinfo.dirfd, &rights) < 0 &&
2452                             errno != ENOSYS) {
2453                                 error("unable to limit directory rights");
2454                         }
2455                         if (cap_fcntls_limit(dumpinfo.dirfd, CAP_FCNTL_GETFL) < 0 &&
2456                             errno != ENOSYS) {
2457                                 error("unable to limit dump descriptor fcntls");
2458                         }
2459 #else   /* !HAVE_CAPSICUM */
2460                         dumpinfo.WFileName = WFileName;
2461 #endif
2462                         callback = dump_packet_and_trunc;
2463                         dumpinfo.pd = pd;
2464                         dumpinfo.pdd = pdd;
2465                         pcap_userdata = (u_char *)&dumpinfo;
2466                 } else {
2467                         callback = dump_packet;
2468                         dumpinfo.WFileName = WFileName;
2469                         dumpinfo.pd = pd;
2470                         dumpinfo.pdd = pdd;
2471                         pcap_userdata = (u_char *)&dumpinfo;
2472                 }
2473                 if (print) {
2474                         dlt = pcap_datalink(pd);
2475                         ndo->ndo_if_printer = get_if_printer(dlt);
2476                         dumpinfo.ndo = ndo;
2477                 } else
2478                         dumpinfo.ndo = NULL;
2479
2480 #ifdef HAVE_PCAP_DUMP_FLUSH
2481                 if (Uflag)
2482                         pcap_dump_flush(pdd);
2483 #endif
2484         } else {
2485                 dlt = pcap_datalink(pd);
2486                 ndo->ndo_if_printer = get_if_printer(dlt);
2487                 callback = print_packet;
2488                 pcap_userdata = (u_char *)ndo;
2489         }
2490
2491 #ifdef SIGNAL_REQ_INFO
2492         /*
2493          * We can't get statistics when reading from a file rather
2494          * than capturing from a device.
2495          */
2496         if (RFileName == NULL)
2497                 (void)setsignal(SIGNAL_REQ_INFO, requestinfo);
2498 #endif
2499 #ifdef SIGNAL_FLUSH_PCAP
2500         (void)setsignal(SIGNAL_FLUSH_PCAP, flushpcap);
2501 #endif
2502
2503         if (ndo->ndo_vflag > 0 && WFileName && RFileName == NULL && !print) {
2504                 /*
2505                  * When capturing to a file, if "--print" wasn't specified,
2506                  *"-v" means tcpdump should, once per second,
2507                  * "v"erbosely report the number of packets captured.
2508                  * Except when reading from a file, because -r, -w and -v
2509                  * together used to make a corner case, in which pcap_loop()
2510                  * errored due to EINTR (see GH #155 for details).
2511                  */
2512 #ifdef _WIN32
2513                 /*
2514                  * https://blogs.msdn.microsoft.com/oldnewthing/20151230-00/?p=92741
2515                  *
2516                  * suggests that this dates back to W2K.
2517                  *
2518                  * I don't know what a "long wait" is, but we'll assume
2519                  * that printing the stats could be a "long wait".
2520                  */
2521                 CreateTimerQueueTimer(&timer_handle, NULL,
2522                     verbose_stats_dump, NULL, 1000, 1000,
2523                     WT_EXECUTEDEFAULT|WT_EXECUTELONGFUNCTION);
2524                 setvbuf(stderr, NULL, _IONBF, 0);
2525 #else /* _WIN32 */
2526                 /*
2527                  * Assume this is UN*X, and that it has setitimer(); that
2528                  * dates back to UNIX 95.
2529                  */
2530                 struct itimerval timer;
2531                 (void)setsignal(SIGALRM, verbose_stats_dump);
2532                 timer.it_interval.tv_sec = 1;
2533                 timer.it_interval.tv_usec = 0;
2534                 timer.it_value.tv_sec = 1;
2535                 timer.it_value.tv_usec = 1;
2536                 setitimer(ITIMER_REAL, &timer, NULL);
2537 #endif /* _WIN32 */
2538         }
2539
2540         if (RFileName == NULL) {
2541                 /*
2542                  * Live capture (if -V was specified, we set RFileName
2543                  * to a file from the -V file).  Print a message to
2544                  * the standard error on UN*X.
2545                  */
2546                 if (!ndo->ndo_vflag && !WFileName) {
2547                         (void)fprintf(stderr,
2548                             "%s: verbose output suppressed, use -v[v]... for full protocol decode\n",
2549                             program_name);
2550                 } else
2551                         (void)fprintf(stderr, "%s: ", program_name);
2552                 dlt = pcap_datalink(pd);
2553                 dlt_name = pcap_datalink_val_to_name(dlt);
2554                 (void)fprintf(stderr, "listening on %s", device);
2555                 if (dlt_name == NULL) {
2556                         (void)fprintf(stderr, ", link-type %u", dlt);
2557                 } else {
2558                         (void)fprintf(stderr, ", link-type %s (%s)", dlt_name,
2559                                       pcap_datalink_val_to_description(dlt));
2560                 }
2561                 (void)fprintf(stderr, ", snapshot length %d bytes\n", ndo->ndo_snaplen);
2562                 (void)fflush(stderr);
2563         }
2564
2565 #ifdef HAVE_CAPSICUM
2566         cansandbox = (VFileName == NULL && zflag == NULL &&
2567             ndo->ndo_espsecret == NULL);
2568 #ifdef HAVE_CASPER
2569         cansandbox = (cansandbox && (ndo->ndo_nflag || capdns != NULL));
2570 #else
2571         cansandbox = (cansandbox && ndo->ndo_nflag);
2572 #endif  /* HAVE_CASPER */
2573         cansandbox = (cansandbox && (pcap_fileno(pd) != -1 ||
2574             RFileName != NULL));
2575
2576         if (cansandbox && cap_enter() < 0 && errno != ENOSYS)
2577                 error("unable to enter the capability mode");
2578 #endif  /* HAVE_CAPSICUM */
2579
2580         do {
2581                 status = pcap_loop(pd, cnt, callback, pcap_userdata);
2582                 if (WFileName == NULL) {
2583                         /*
2584                          * We're printing packets.  Flush the printed output,
2585                          * so it doesn't get intermingled with error output.
2586                          */
2587                         if (status == -2) {
2588                                 /*
2589                                  * We got interrupted, so perhaps we didn't
2590                                  * manage to finish a line we were printing.
2591                                  * Print an extra newline, just in case.
2592                                  */
2593                                 putchar('\n');
2594                         }
2595                         (void)fflush(stdout);
2596                 }
2597                 if (status == -2) {
2598                         /*
2599                          * We got interrupted. If we are reading multiple
2600                          * files (via -V) set these so that we stop.
2601                          */
2602                         VFileName = NULL;
2603                         ret = NULL;
2604                 }
2605                 if (status == -1) {
2606                         /*
2607                          * Error.  Report it.
2608                          */
2609                         (void)fprintf(stderr, "%s: pcap_loop: %s\n",
2610                             program_name, pcap_geterr(pd));
2611                 }
2612                 if (RFileName == NULL) {
2613                         /*
2614                          * We're doing a live capture.  Report the capture
2615                          * statistics.
2616                          */
2617                         info(1);
2618                 }
2619                 pcap_close(pd);
2620                 if (VFileName != NULL) {
2621                         ret = get_next_file(VFile, VFileLine);
2622                         if (ret) {
2623                                 int new_dlt;
2624
2625                                 RFileName = VFileLine;
2626                                 pd = pcap_open_offline(RFileName, ebuf);
2627                                 if (pd == NULL)
2628                                         error("%s", ebuf);
2629 #ifdef HAVE_CAPSICUM
2630                                 cap_rights_init(&rights, CAP_READ);
2631                                 if (cap_rights_limit(fileno(pcap_file(pd)),
2632                                     &rights) < 0 && errno != ENOSYS) {
2633                                         error("unable to limit pcap descriptor");
2634                                 }
2635 #endif
2636                                 new_dlt = pcap_datalink(pd);
2637                                 if (new_dlt != dlt) {
2638                                         /*
2639                                          * The new file has a different
2640                                          * link-layer header type from the
2641                                          * previous one.
2642                                          */
2643                                         if (WFileName != NULL) {
2644                                                 /*
2645                                                  * We're writing raw packets
2646                                                  * that match the filter to
2647                                                  * a pcap file.  pcap files
2648                                                  * don't support multiple
2649                                                  * different link-layer
2650                                                  * header types, so we fail
2651                                                  * here.
2652                                                  */
2653                                                 error("%s: new dlt does not match original", RFileName);
2654                                         }
2655
2656                                         /*
2657                                          * We're printing the decoded packets;
2658                                          * switch to the new DLT.
2659                                          *
2660                                          * To do that, we need to change
2661                                          * the printer, change the DLT name,
2662                                          * and recompile the filter with
2663                                          * the new DLT.
2664                                          */
2665                                         dlt = new_dlt;
2666                                         ndo->ndo_if_printer = get_if_printer(dlt);
2667                                         if (pcap_compile(pd, &fcode, cmdbuf, Oflag, netmask) < 0)
2668                                                 error("%s", pcap_geterr(pd));
2669                                 }
2670
2671                                 /*
2672                                  * Set the filter on the new file.
2673                                  */
2674                                 if (pcap_setfilter(pd, &fcode) < 0)
2675                                         error("%s", pcap_geterr(pd));
2676
2677                                 /*
2678                                  * Report the new file.
2679                                  */
2680                                 dlt_name = pcap_datalink_val_to_name(dlt);
2681                                 fprintf(stderr, "reading from file %s", RFileName);
2682                                 if (dlt_name == NULL) {
2683                                         fprintf(stderr, ", link-type %u", dlt);
2684                                 } else {
2685                                         fprintf(stderr, ", link-type %s (%s)",
2686                                                 dlt_name,
2687                                                 pcap_datalink_val_to_description(dlt));
2688                                 }
2689                                 fprintf(stderr, ", snapshot length %d\n", pcap_snapshot(pd));
2690                         }
2691                 }
2692         }
2693         while (ret != NULL);
2694
2695         if (count_mode && RFileName != NULL)
2696                 fprintf(stdout, "%u packet%s\n", packets_captured,
2697                         PLURAL_SUFFIX(packets_captured));
2698
2699         free(cmdbuf);
2700         pcap_freecode(&fcode);
2701         exit_tcpdump(status == -1 ? S_ERR_HOST_PROGRAM : S_SUCCESS);
2702 }
2703
2704 /*
2705  * Catch a signal.
2706  */
2707 static void
2708 (*setsignal (int sig, void (*func)(int)))(int)
2709 {
2710 #ifdef _WIN32
2711         return (signal(sig, func));
2712 #else
2713         struct sigaction old, new;
2714
2715         memset(&new, 0, sizeof(new));
2716         new.sa_handler = func;
2717         if ((sig == SIGCHLD)
2718 # ifdef SIGNAL_REQ_INFO
2719                 || (sig == SIGNAL_REQ_INFO)
2720 # endif
2721 # ifdef SIGNAL_FLUSH_PCAP
2722                 || (sig == SIGNAL_FLUSH_PCAP)
2723 # endif
2724                 )
2725                 new.sa_flags = SA_RESTART;
2726         if (sigaction(sig, &new, &old) < 0)
2727                 return (SIG_ERR);
2728         return (old.sa_handler);
2729 #endif
2730 }
2731
2732 /* make a clean exit on interrupts */
2733 static void
2734 cleanup(int signo _U_)
2735 {
2736 #ifdef _WIN32
2737         if (timer_handle != INVALID_HANDLE_VALUE) {
2738                 DeleteTimerQueueTimer(NULL, timer_handle, NULL);
2739                 CloseHandle(timer_handle);
2740                 timer_handle = INVALID_HANDLE_VALUE;
2741         }
2742 #else /* _WIN32 */
2743         struct itimerval timer;
2744
2745         timer.it_interval.tv_sec = 0;
2746         timer.it_interval.tv_usec = 0;
2747         timer.it_value.tv_sec = 0;
2748         timer.it_value.tv_usec = 0;
2749         setitimer(ITIMER_REAL, &timer, NULL);
2750 #endif /* _WIN32 */
2751
2752 #ifdef HAVE_PCAP_BREAKLOOP
2753         /*
2754          * We have "pcap_breakloop()"; use it, so that we do as little
2755          * as possible in the signal handler (it's probably not safe
2756          * to do anything with standard I/O streams in a signal handler -
2757          * the ANSI C standard doesn't say it is).
2758          */
2759         pcap_breakloop(pd);
2760 #else
2761         /*
2762          * We don't have "pcap_breakloop()"; this isn't safe, but
2763          * it's the best we can do.  Print the summary if we're
2764          * not reading from a savefile - i.e., if we're doing a
2765          * live capture - and exit.
2766          */
2767         if (pd != NULL && pcap_file(pd) == NULL) {
2768                 /*
2769                  * We got interrupted, so perhaps we didn't
2770                  * manage to finish a line we were printing.
2771                  * Print an extra newline, just in case.
2772                  */
2773                 putchar('\n');
2774                 (void)fflush(stdout);
2775                 info(1);
2776         }
2777         exit_tcpdump(S_SUCCESS);
2778 #endif
2779 }
2780
2781 /*
2782   On windows, we do not use a fork, so we do not care less about
2783   waiting a child processes to die
2784  */
2785 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2786 static void
2787 child_cleanup(int signo _U_)
2788 {
2789   wait(NULL);
2790 }
2791 #endif /* HAVE_FORK && HAVE_VFORK */
2792
2793 static void
2794 info(int verbose)
2795 {
2796         struct pcap_stat stats;
2797
2798         /*
2799          * Older versions of libpcap didn't set ps_ifdrop on some
2800          * platforms; initialize it to 0 to handle that.
2801          */
2802         stats.ps_ifdrop = 0;
2803         if (pcap_stats(pd, &stats) < 0) {
2804                 (void)fprintf(stderr, "pcap_stats: %s\n", pcap_geterr(pd));
2805                 infoprint = 0;
2806                 return;
2807         }
2808
2809         if (!verbose)
2810                 fprintf(stderr, "%s: ", program_name);
2811
2812         (void)fprintf(stderr, "%u packet%s captured", packets_captured,
2813             PLURAL_SUFFIX(packets_captured));
2814         if (!verbose)
2815                 fputs(", ", stderr);
2816         else
2817                 putc('\n', stderr);
2818         (void)fprintf(stderr, "%u packet%s received by filter", stats.ps_recv,
2819             PLURAL_SUFFIX(stats.ps_recv));
2820         if (!verbose)
2821                 fputs(", ", stderr);
2822         else
2823                 putc('\n', stderr);
2824         (void)fprintf(stderr, "%u packet%s dropped by kernel", stats.ps_drop,
2825             PLURAL_SUFFIX(stats.ps_drop));
2826         if (stats.ps_ifdrop != 0) {
2827                 if (!verbose)
2828                         fputs(", ", stderr);
2829                 else
2830                         putc('\n', stderr);
2831                 (void)fprintf(stderr, "%u packet%s dropped by interface\n",
2832                     stats.ps_ifdrop, PLURAL_SUFFIX(stats.ps_ifdrop));
2833         } else
2834                 putc('\n', stderr);
2835         infoprint = 0;
2836 }
2837
2838 #if defined(HAVE_FORK) || defined(HAVE_VFORK)
2839 #ifdef HAVE_FORK
2840 #define fork_subprocess() fork()
2841 #else
2842 #define fork_subprocess() vfork()
2843 #endif
2844 static void
2845 compress_savefile(const char *filename)
2846 {
2847         pid_t child;
2848
2849         child = fork_subprocess();
2850         if (child == -1) {
2851                 fprintf(stderr,
2852                         "compress_savefile: fork failed: %s\n",
2853                         pcap_strerror(errno));
2854                 return;
2855         }
2856         if (child != 0) {
2857                 /* Parent process. */
2858                 return;
2859         }
2860
2861         /*
2862          * Child process.
2863          * Set to lowest priority so that this doesn't disturb the capture.
2864          */
2865 #ifdef NZERO
2866         setpriority(PRIO_PROCESS, 0, NZERO - 1);
2867 #else
2868         setpriority(PRIO_PROCESS, 0, 19);
2869 #endif
2870         if (execlp(zflag, zflag, filename, (char *)NULL) == -1)
2871                 fprintf(stderr,
2872                         "compress_savefile: execlp(%s, %s) failed: %s\n",
2873                         zflag,
2874                         filename,
2875                         pcap_strerror(errno));
2876 #ifdef HAVE_FORK
2877         exit(S_ERR_HOST_PROGRAM);
2878 #else
2879         _exit(S_ERR_HOST_PROGRAM);
2880 #endif
2881 }
2882 #else  /* HAVE_FORK && HAVE_VFORK */
2883 static void
2884 compress_savefile(const char *filename)
2885 {
2886         fprintf(stderr,
2887                 "compress_savefile failed. Functionality not implemented under your system\n");
2888 }
2889 #endif /* HAVE_FORK && HAVE_VFORK */
2890
2891 static void
2892 dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
2893 {
2894         struct dump_info *dump_info;
2895
2896         ++packets_captured;
2897
2898         ++infodelay;
2899
2900         dump_info = (struct dump_info *)user;
2901
2902         /*
2903          * XXX - this won't force the file to rotate on the specified time
2904          * boundary, but it will rotate on the first packet received after the
2905          * specified Gflag number of seconds. Note: if a Gflag time boundary
2906          * and a Cflag size boundary coincide, the time rotation will occur
2907          * first thereby cancelling the Cflag boundary (since the file should
2908          * be 0).
2909          */
2910         if (Gflag != 0) {
2911                 /* Check if it is time to rotate */
2912                 time_t t;
2913
2914                 /* Get the current time */
2915                 if ((t = time(NULL)) == (time_t)-1) {
2916                         error("%s: can't get current_time: %s",
2917                             __func__, pcap_strerror(errno));
2918                 }
2919
2920
2921                 /* If the time is greater than the specified window, rotate */
2922                 if (t - Gflag_time >= Gflag) {
2923 #ifdef HAVE_CAPSICUM
2924                         FILE *fp;
2925                         int fd;
2926 #endif
2927
2928                         /* Update the Gflag_time */
2929                         Gflag_time = t;
2930                         /* Update Gflag_count */
2931                         Gflag_count++;
2932                         /*
2933                          * Close the current file and open a new one.
2934                          */
2935                         pcap_dump_close(dump_info->pdd);
2936
2937                         /*
2938                          * Compress the file we just closed, if the user asked for it
2939                          */
2940                         if (zflag != NULL)
2941                                 compress_savefile(dump_info->CurrentFileName);
2942
2943                         /*
2944                          * Check to see if we've exceeded the Wflag (when
2945                          * not using Cflag).
2946                          */
2947                         if (Cflag == 0 && Wflag > 0 && Gflag_count >= Wflag) {
2948                                 (void)fprintf(stderr, "Maximum file limit reached: %d\n",
2949                                     Wflag);
2950                                 info(1);
2951                                 exit_tcpdump(S_SUCCESS);
2952                                 /* NOTREACHED */
2953                         }
2954                         if (dump_info->CurrentFileName != NULL)
2955                                 free(dump_info->CurrentFileName);
2956                         /* Allocate space for max filename + \0. */
2957                         dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
2958                         if (dump_info->CurrentFileName == NULL)
2959                                 error("dump_packet_and_trunc: malloc");
2960                         /*
2961                          * Gflag was set otherwise we wouldn't be here. Reset the count
2962                          * so multiple files would end with 1,2,3 in the filename.
2963                          * The counting is handled with the -C flow after this.
2964                          */
2965                         Cflag_count = 0;
2966
2967                         /*
2968                          * This is always the first file in the Cflag
2969                          * rotation: e.g. 0
2970                          * We also don't need numbering if Cflag is not set.
2971                          */
2972                         if (Cflag != 0)
2973                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0,
2974                                     WflagChars);
2975                         else
2976                                 MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, 0, 0);
2977
2978 #ifdef HAVE_LIBCAP_NG
2979                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
2980                         capng_apply(CAPNG_SELECT_BOTH);
2981 #endif /* HAVE_LIBCAP_NG */
2982 #ifdef HAVE_CAPSICUM
2983                         fd = openat(dump_info->dirfd,
2984                             dump_info->CurrentFileName,
2985                             O_CREAT | O_WRONLY | O_TRUNC, 0644);
2986                         if (fd < 0) {
2987                                 error("unable to open file %s",
2988                                     dump_info->CurrentFileName);
2989                         }
2990                         fp = fdopen(fd, "w");
2991                         if (fp == NULL) {
2992                                 error("unable to fdopen file %s",
2993                                     dump_info->CurrentFileName);
2994                         }
2995                         dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
2996 #else   /* !HAVE_CAPSICUM */
2997                         dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
2998 #endif
2999 #ifdef HAVE_LIBCAP_NG
3000                         capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3001                         capng_apply(CAPNG_SELECT_BOTH);
3002 #endif /* HAVE_LIBCAP_NG */
3003                         if (dump_info->pdd == NULL)
3004                                 error("%s", pcap_geterr(pd));
3005 #ifdef HAVE_CAPSICUM
3006                         set_dumper_capsicum_rights(dump_info->pdd);
3007 #endif
3008                 }
3009         }
3010
3011         /*
3012          * XXX - this won't prevent capture files from getting
3013          * larger than Cflag - the last packet written to the
3014          * file could put it over Cflag.
3015          */
3016         if (Cflag != 0) {
3017 #ifdef HAVE_PCAP_DUMP_FTELL64
3018                 int64_t size = pcap_dump_ftell64(dump_info->pdd);
3019 #else
3020                 /*
3021                  * XXX - this only handles a Cflag value > 2^31-1 on
3022                  * LP64 platforms; to handle ILP32 (32-bit UN*X and
3023                  * Windows) or LLP64 (64-bit Windows) would require
3024                  * a version of libpcap with pcap_dump_ftell64().
3025                  */
3026                 long size = pcap_dump_ftell(dump_info->pdd);
3027 #endif
3028
3029                 if (size == -1)
3030                         error("ftell fails on output file");
3031                 if (size > Cflag) {
3032 #ifdef HAVE_CAPSICUM
3033                         FILE *fp;
3034                         int fd;
3035 #endif
3036
3037                         /*
3038                          * Close the current file and open a new one.
3039                          */
3040                         pcap_dump_close(dump_info->pdd);
3041
3042                         /*
3043                          * Compress the file we just closed, if the user
3044                          * asked for it.
3045                          */
3046                         if (zflag != NULL)
3047                                 compress_savefile(dump_info->CurrentFileName);
3048
3049                         Cflag_count++;
3050                         if (Wflag > 0) {
3051                                 if (Cflag_count >= Wflag)
3052                                         Cflag_count = 0;
3053                         }
3054                         if (dump_info->CurrentFileName != NULL)
3055                                 free(dump_info->CurrentFileName);
3056                         dump_info->CurrentFileName = (char *)malloc(PATH_MAX + 1);
3057                         if (dump_info->CurrentFileName == NULL)
3058                                 error("%s: malloc", __func__);
3059                         MakeFilename(dump_info->CurrentFileName, dump_info->WFileName, Cflag_count, WflagChars);
3060 #ifdef HAVE_LIBCAP_NG
3061                         capng_update(CAPNG_ADD, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3062                         capng_apply(CAPNG_SELECT_BOTH);
3063 #endif /* HAVE_LIBCAP_NG */
3064 #ifdef HAVE_CAPSICUM
3065                         fd = openat(dump_info->dirfd, dump_info->CurrentFileName,
3066                             O_CREAT | O_WRONLY | O_TRUNC, 0644);
3067                         if (fd < 0) {
3068                                 error("unable to open file %s",
3069                                     dump_info->CurrentFileName);
3070                         }
3071                         fp = fdopen(fd, "w");
3072                         if (fp == NULL) {
3073                                 error("unable to fdopen file %s",
3074                                     dump_info->CurrentFileName);
3075                         }
3076                         dump_info->pdd = pcap_dump_fopen(dump_info->pd, fp);
3077 #else   /* !HAVE_CAPSICUM */
3078                         dump_info->pdd = pcap_dump_open(dump_info->pd, dump_info->CurrentFileName);
3079 #endif
3080 #ifdef HAVE_LIBCAP_NG
3081                         capng_update(CAPNG_DROP, CAPNG_EFFECTIVE, CAP_DAC_OVERRIDE);
3082                         capng_apply(CAPNG_SELECT_BOTH);
3083 #endif /* HAVE_LIBCAP_NG */
3084                         if (dump_info->pdd == NULL)
3085                                 error("%s", pcap_geterr(pd));
3086 #ifdef HAVE_CAPSICUM
3087                         set_dumper_capsicum_rights(dump_info->pdd);
3088 #endif
3089                 }
3090         }
3091
3092         pcap_dump((u_char *)dump_info->pdd, h, sp);
3093 #ifdef HAVE_PCAP_DUMP_FLUSH
3094         if (Uflag)
3095                 pcap_dump_flush(dump_info->pdd);
3096 #endif
3097
3098         if (dump_info->ndo != NULL)
3099                 pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3100
3101         --infodelay;
3102         if (infoprint)
3103                 info(0);
3104 }
3105
3106 static void
3107 dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3108 {
3109         struct dump_info *dump_info;
3110
3111         ++packets_captured;
3112
3113         ++infodelay;
3114
3115         dump_info = (struct dump_info *)user;
3116
3117         pcap_dump((u_char *)dump_info->pdd, h, sp);
3118 #ifdef HAVE_PCAP_DUMP_FLUSH
3119         if (Uflag)
3120                 pcap_dump_flush(dump_info->pdd);
3121 #endif
3122
3123         if (dump_info->ndo != NULL)
3124                 pretty_print_packet(dump_info->ndo, h, sp, packets_captured);
3125
3126         --infodelay;
3127         if (infoprint)
3128                 info(0);
3129 }
3130
3131 static void
3132 print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
3133 {
3134         ++packets_captured;
3135
3136         ++infodelay;
3137
3138         if (!count_mode)
3139                 pretty_print_packet((netdissect_options *)user, h, sp, packets_captured);
3140
3141         --infodelay;
3142         if (infoprint)
3143                 info(0);
3144 }
3145
3146 #ifdef SIGNAL_REQ_INFO
3147 static void
3148 requestinfo(int signo _U_)
3149 {
3150         if (infodelay)
3151                 ++infoprint;
3152         else
3153                 info(0);
3154 }
3155 #endif
3156
3157 #ifdef SIGNAL_FLUSH_PCAP
3158 static void
3159 flushpcap(int signo _U_)
3160 {
3161         if (pdd != NULL)
3162                 pcap_dump_flush(pdd);
3163 }
3164 #endif
3165
3166 static void
3167 print_packets_captured (void)
3168 {
3169         static u_int prev_packets_captured, first = 1;
3170
3171         if (infodelay == 0 && (first || packets_captured != prev_packets_captured)) {
3172                 fprintf(stderr, "Got %u\r", packets_captured);
3173                 first = 0;
3174                 prev_packets_captured = packets_captured;
3175         }
3176 }
3177
3178 /*
3179  * Called once each second in verbose mode while dumping to file
3180  */
3181 #ifdef _WIN32
3182 static void CALLBACK verbose_stats_dump(PVOID param _U_,
3183     BOOLEAN timer_fired _U_)
3184 {
3185         print_packets_captured();
3186 }
3187 #else /* _WIN32 */
3188 static void verbose_stats_dump(int sig _U_)
3189 {
3190         print_packets_captured();
3191 }
3192 #endif /* _WIN32 */
3193
3194 DIAG_OFF_DEPRECATION
3195 static void
3196 print_version(FILE *f)
3197 {
3198 #ifndef HAVE_PCAP_LIB_VERSION
3199   #ifdef HAVE_PCAP_VERSION
3200         extern char pcap_version[];
3201   #else /* HAVE_PCAP_VERSION */
3202         static char pcap_version[] = "unknown";
3203   #endif /* HAVE_PCAP_VERSION */
3204 #endif /* HAVE_PCAP_LIB_VERSION */
3205         const char *smi_version_string;
3206
3207         (void)fprintf(f, "%s version " PACKAGE_VERSION "\n", program_name);
3208 #ifdef HAVE_PCAP_LIB_VERSION
3209         (void)fprintf(f, "%s\n", pcap_lib_version());
3210 #else /* HAVE_PCAP_LIB_VERSION */
3211         (void)fprintf(f, "libpcap version %s\n", pcap_version);
3212 #endif /* HAVE_PCAP_LIB_VERSION */
3213
3214 #if defined(HAVE_LIBCRYPTO) && defined(SSLEAY_VERSION)
3215         (void)fprintf (f, "%s\n", SSLeay_version(SSLEAY_VERSION));
3216 #endif
3217
3218         smi_version_string = nd_smi_version_string();
3219         if (smi_version_string != NULL)
3220                 (void)fprintf (f, "SMI-library: %s\n", smi_version_string);
3221
3222 #if defined(__SANITIZE_ADDRESS__)
3223         (void)fprintf (f, "Compiled with AddressSanitizer/GCC.\n");
3224 #elif defined(__has_feature)
3225 #  if __has_feature(address_sanitizer)
3226         (void)fprintf (f, "Compiled with AddressSanitizer/Clang.\n");
3227 #  elif __has_feature(memory_sanitizer)
3228         (void)fprintf (f, "Compiled with MemorySanitizer/Clang.\n");
3229 #  endif
3230 #endif /* __SANITIZE_ADDRESS__ or __has_feature */
3231 }
3232 DIAG_ON_DEPRECATION
3233
3234 static void
3235 print_usage(FILE *f)
3236 {
3237         print_version(f);
3238         (void)fprintf(f,
3239 "Usage: %s [-Abd" D_FLAG "efhH" I_FLAG J_FLAG "KlLnNOpqStu" U_FLAG "vxX#]" B_FLAG_USAGE " [ -c count ] [--count]\n", program_name);
3240         (void)fprintf(f,
3241 "\t\t[ -C file_size ] [ -E algo:secret ] [ -F file ] [ -G seconds ]\n");
3242         (void)fprintf(f,
3243 "\t\t[ -i interface ]" IMMEDIATE_MODE_USAGE j_FLAG_USAGE "\n");
3244 #ifdef HAVE_PCAP_FINDALLDEVS_EX
3245         (void)fprintf(f,
3246 "\t\t" LIST_REMOTE_INTERFACES_USAGE "\n");
3247 #endif
3248 #ifdef USE_LIBSMI
3249         (void)fprintf(f,
3250 "\t\t" m_FLAG_USAGE "\n");
3251 #endif
3252         (void)fprintf(f,
3253 "\t\t[ -M secret ] [ --number ] [ --print ]" Q_FLAG_USAGE "\n");
3254         (void)fprintf(f,
3255 "\t\t[ -r file ] [ -s snaplen ] [ -T type ] [ --version ]\n");
3256         (void)fprintf(f,
3257 "\t\t[ -V file ] [ -w file ] [ -W filecount ] [ -y datalinktype ]\n");
3258 #ifdef HAVE_PCAP_SET_TSTAMP_PRECISION
3259         (void)fprintf(f,
3260 "\t\t[ --time-stamp-precision precision ] [ --micro ] [ --nano ]\n");
3261 #endif
3262         (void)fprintf(f,
3263 "\t\t[ -z postrotate-command ] [ -Z user ] [ expression ]\n");
3264 }