/* tethereal.c
 *
 * $Id: tethereal.c,v 1.151 2002/08/02 23:36:07 jmayer Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 1998 Gerald Combs
 *
 * Text-mode variant, by Gilbert Ramirez <gram@alumni.rice.edu>
 * and Guy Harris <guy@alum.mit.edu>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <locale.h>
#include <limits.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include <errno.h>

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif

#include <signal.h>

#ifdef HAVE_LIBPCAP
#include <pcap.h>
#include <setjmp.h>
#endif

#ifdef HAVE_LIBZ
#include <zlib.h>	/* to get the libz version number */
#endif

#ifdef NEED_SNPRINTF_H
# include "snprintf.h"
#endif

#ifdef HAVE_UCD_SNMP_VERSION_H
#include <ucd-snmp/version.h>
#endif /* HAVE_UCD_SNMP_VERSION_H */

#ifdef NEED_STRERROR_H
#include "strerror.h"
#endif

#ifdef NEED_GETOPT_H
#include "getopt.h"
#endif

#include <glib.h>
#include <epan/epan.h>
#include <epan/filesystem.h>

#include "globals.h"
#include <epan/timestamp.h>
#include <epan/packet.h>
#include "file.h"
#include "prefs.h"
#include "column.h"
#include "print.h"
#include <epan/resolv.h>
#include "util.h"
#ifdef HAVE_LIBPCAP
#include "pcap-util.h"
#endif
#include <epan/conversation.h>
#include <epan/plugins.h>
#include "register.h"
#include "conditions.h"
#include "capture_stop_conditions.h"
#include "ringbuffer.h"
#include <epan/epan_dissect.h>

#ifdef HAVE_LIBPCAP
#include <wiretap/wtap-capture.h>
#endif

#ifdef WIN32
#include "capture-wpcap.h"
#endif

static guint32 firstsec, firstusec;
static guint32 prevsec, prevusec;
static GString *comp_info_str;
static gboolean quiet;
static gboolean verbose;
static gboolean print_hex;
static gboolean line_buffered;

#ifdef HAVE_LIBPCAP
typedef struct _loop_data {
  gboolean       go;           /* TRUE as long as we're supposed to keep capturing */
  gint           linktype;
  pcap_t        *pch;
  wtap_dumper   *pdh;
  jmp_buf        stopenv;
  gboolean       output_to_pipe;
  int            packet_count;
} loop_data;

static loop_data ld;

static int capture(int);
static void capture_pcap_cb(guchar *, const struct pcap_pkthdr *,
  const guchar *);
#ifdef _WIN32
static BOOL WINAPI capture_cleanup(DWORD);
#else /* _WIN32 */
static void capture_cleanup(int);
#endif /* _WIN32 */
#endif /* HAVE_LIBPCAP */

typedef struct {
  capture_file *cf;
  wtap_dumper *pdh;
} cb_args_t;

static int load_cap_file(capture_file *, int);
static void wtap_dispatch_cb_write(guchar *, const struct wtap_pkthdr *, long,
    union wtap_pseudo_header *, const guchar *);
static void show_capture_file_io_error(const char *, int, gboolean);
static void wtap_dispatch_cb_print(guchar *, const struct wtap_pkthdr *, long,
    union wtap_pseudo_header *, const guchar *);

capture_file cfile;
ts_type timestamp_type = RELATIVE;
#ifdef HAVE_LIBPCAP
typedef struct {
	int snaplen;			/* Maximum captured packet length */
	int promisc_mode;		/* Capture in promiscuous mode */
	int autostop_count;		/* Maximum packet count */
	gboolean has_autostop_duration;	/* TRUE if maximum capture duration
					   is specified */
	gint32 autostop_duration;	/* Maximum capture duration */
	gboolean has_autostop_filesize;	/* TRUE if maximum capture file size
					   is specified */
	gint32 autostop_filesize;	/* Maximum capture file size */
	gboolean ringbuffer_on;		/* TRUE if ring buffer in use */
	guint32 ringbuffer_num_files;	/* Number of ring buffer files */
} capture_options;

static capture_options capture_opts = {
	WTAP_MAX_PACKET_SIZE,		/* snapshot length - default is
					   infinite, in effect */
	TRUE,				/* promiscuous mode is the default */
	0,				/* max packet count - default is 0,
					   meaning infinite */
	FALSE,				/* maximum capture duration not
					   specified by default */
	0,				/* maximum capture duration */
	FALSE,				/* maximum capture file size not
					   specified by default */
	0,				/* maximum capture file size */
	FALSE,				/* ring buffer off by default */
	RINGBUFFER_MIN_NUM_FILES	/* default number of ring buffer
					   files */
};
#endif

static void 
print_usage(gboolean print_ver)
{
  int i;

  if (print_ver) {
    fprintf(stderr, "This is GNU t%s %s, compiled %s\n", PACKAGE, VERSION,
	comp_info_str->str);
  }
#ifdef HAVE_LIBPCAP
  fprintf(stderr, "\nt%s [ -DvVhqlp ] [ -a <capture autostop condition> ] ...\n",
	  PACKAGE);
  fprintf(stderr, "\t[ -b <number of ring buffer files> ] [ -c <count> ]\n");
  fprintf(stderr, "\t[ -f <capture filter> ] [ -F <output file type> ]\n");
  fprintf(stderr, "\t[ -i <interface> ] [ -n ] [ -N <resolving> ]\n");
  fprintf(stderr, "\t[ -o <preference setting> ] ... [ -r <infile> ] [ -R <read filter> ]\n");
  fprintf(stderr, "\t[ -s <snaplen> ] [ -t <time stamp format> ] [ -w <savefile> ] [ -x ]\n");
#else
  fprintf(stderr, "\nt%s [ -vVhl ] [ -F <output file type> ] [ -n ] [ -N <resolving> ]\n", PACKAGE);
  fprintf(stderr, "\t[ -o <preference setting> ] ... [ -r <infile> ] [ -R <read filter> ]\n");
  fprintf(stderr, "\t[ -t <time stamp format> ] [ -w <savefile> ] [ -x ]\n");
#endif
  fprintf(stderr, "Valid file type arguments to the \"-F\" flag:\n");
  for (i = 0; i < WTAP_NUM_FILE_TYPES; i++) {
    if (wtap_dump_can_open(i))
      fprintf(stderr, "\t%s - %s\n",
        wtap_file_type_short_string(i), wtap_file_type_string(i));
  }
  fprintf(stderr, "\tdefault is libpcap\n");
}

#ifdef HAVE_LIBPCAP
static int
get_positive_int(const char *string, const char *name)
{
  long number;
  char *p;

  number = strtol(string, &p, 10);
  if (p == string || *p != '\0') {
    fprintf(stderr, "tethereal: The specified %s \"%s\" is not a decimal number\n",
	    name, string);
    exit(1);
  }
  if (number < 0) {
    fprintf(stderr, "tethereal: The specified %s is a negative number\n",
	    name);
    exit(1);
  }
  if (number == 0) {
    fprintf(stderr, "tethereal: The specified %s is zero\n",
	    name);
    exit(1);
  }
  if (number > INT_MAX) {
    fprintf(stderr, "tethereal: The specified %s is too large (greater than %d)\n",
	    name, INT_MAX);
    exit(1);
  }
  return number;
}

/*
 * Given a string of the form "<autostop criterion>:<value>", as might appear
 * as an argument to a "-a" option, parse it and set the criterion in
 * question.  Return an indication of whether it succeeded or failed
 * in some fashion.
 */
static gboolean
set_autostop_criterion(const char *autostoparg)
{
  guchar *p, *colonp;

  colonp = strchr(autostoparg, ':');
  if (colonp == NULL)
    return FALSE;

  p = colonp;
  *p++ = '\0';

  /*
   * Skip over any white space (there probably won't be any, but
   * as we allow it in the preferences file, we might as well
   * allow it here).
   */
  while (isspace(*p))
    p++;
  if (*p == '\0') {
    /*
     * Put the colon back, so if our caller uses, in an
     * error message, the string they passed us, the message
     * looks correct.
     */
    *colonp = ':';
    return FALSE;
  }
  if (strcmp(autostoparg,"duration") == 0) {
    capture_opts.has_autostop_duration = TRUE;
    capture_opts.autostop_duration = get_positive_int(p,"autostop duration");
  } else if (strcmp(autostoparg,"filesize") == 0) {
    capture_opts.has_autostop_filesize = TRUE;
    capture_opts.autostop_filesize = get_positive_int(p,"autostop filesize");
  } else {
    return FALSE;
  }
  *colonp = ':';	/* put the colon back */
  return TRUE;
}
#endif

int
main(int argc, char *argv[])
{
  int                  opt, i;
  extern char         *optarg;
  gboolean             arg_error = FALSE;
#ifdef HAVE_LIBPCAP
#ifdef HAVE_PCAP_VERSION
  extern char          pcap_version[];
#endif /* HAVE_PCAP_VERSION */
#endif /* HAVE_LIBPCAP */

#ifdef WIN32
  WSADATA		wsaData;
#endif

  char                *gpf_path;
  char                *pf_path;
  int                  gpf_open_errno, pf_open_errno;
  int                  err;
#ifdef HAVE_LIBPCAP
  gboolean             capture_filter_specified = FALSE;
  GList               *if_list, *if_entry;
  gchar                err_str[PCAP_ERRBUF_SIZE];
#else
  gboolean             capture_option_specified = FALSE;
#endif
  int                  out_file_type = WTAP_FILE_PCAP;
  gchar               *cf_name = NULL, *rfilter = NULL;
#ifdef HAVE_LIBPCAP
  gchar               *if_text;
#endif
  dfilter_t           *rfcode = NULL;
  e_prefs             *prefs;
  char                 badopt;

  /* Register all dissectors; we must do this before checking for the
     "-G" flag, as the "-G" flag dumps information registered by the
     dissectors, and we must do it before we read the preferences, in
     case any dissectors register preferences. */
  epan_init(PLUGIN_DIR,register_all_protocols,register_all_protocol_handoffs);

  /* Now register the preferences for any non-dissector modules.
     We must do that before we read the preferences as well. */
  prefs_register_modules();

  /* If invoked with the "-G" flag, we dump out information based on
     the argument to the "-G" flag; if no argument is specified,
     for backwards compatibility we dump out a glossary of display
     filter symbols.

     We do this here to mirror what happens in the GTK+ version, although
     it's not necessary here. */
  if (argc >= 2 && strcmp(argv[1], "-G") == 0) {
    if (argc == 2)
      proto_registrar_dump_fields();
    else {
      if (strcmp(argv[2], "fields") == 0)
        proto_registrar_dump_fields();
      else if (strcmp(argv[2], "protocols") == 0)
        proto_registrar_dump_protocols();
      else {
        fprintf(stderr, "tethereal: Invalid \"%s\" option for -G flag\n",
                argv[2]);
        exit(1);
      }
    }
    exit(0);
  }

  /* Set the C-language locale to the native environment. */
  setlocale(LC_ALL, "");

  prefs = read_prefs(&gpf_open_errno, &gpf_path, &pf_open_errno, &pf_path);
  if (gpf_path != NULL) {
    fprintf(stderr, "Can't open global preferences file \"%s\": %s.\n", pf_path,
        strerror(gpf_open_errno));
  }
  if (pf_path != NULL) {
    fprintf(stderr, "Can't open your preferences file \"%s\": %s.\n", pf_path,
        strerror(pf_open_errno));
    g_free(pf_path);
    pf_path = NULL;
  }

  /* Set the name resolution code's flags from the preferences. */
  g_resolv_flags = prefs->name_resolve;

#ifdef WIN32
  /* Load Wpcap, if possible */
  load_wpcap();
#endif
    
  /* Initialize the capture file struct */
  cfile.plist		= NULL;
  cfile.plist_end	= NULL;
  cfile.wth		= NULL;
  cfile.filename	= NULL;
  cfile.user_saved	= FALSE;
  cfile.is_tempfile	= FALSE;
  cfile.rfcode		= NULL;
  cfile.dfilter		= NULL;
  cfile.dfcode		= NULL;
#ifdef HAVE_LIBPCAP
  cfile.cfilter		= g_strdup("");
#endif
  cfile.iface		= NULL;
  cfile.save_file	= NULL;
  cfile.save_file_fd	= -1;
  cfile.has_snap	= FALSE;
  cfile.snap		= WTAP_MAX_PACKET_SIZE;
  cfile.count		= 0;

  /* Assemble the compile-time options */
  comp_info_str = g_string_new("");

  g_string_append(comp_info_str, "with ");
  g_string_sprintfa(comp_info_str,
#ifdef GLIB_MAJOR_VERSION
    "GLib %d.%d.%d", GLIB_MAJOR_VERSION, GLIB_MINOR_VERSION,
    GLIB_MICRO_VERSION);
#else
    "GLib (version unknown)");
#endif

#ifdef HAVE_LIBPCAP
  g_string_append(comp_info_str, ", with libpcap ");
#ifdef HAVE_PCAP_VERSION
  g_string_append(comp_info_str, pcap_version);
#else /* HAVE_PCAP_VERSION */
  g_string_append(comp_info_str, "(version unknown)");
#endif /* HAVE_PCAP_VERSION */
#else /* HAVE_LIBPCAP */
  g_string_append(comp_info_str, ", without libpcap");
#endif /* HAVE_LIBPCAP */

#ifdef HAVE_LIBZ
  g_string_append(comp_info_str, ", with libz ");
#ifdef ZLIB_VERSION
  g_string_append(comp_info_str, ZLIB_VERSION);
#else /* ZLIB_VERSION */
  g_string_append(comp_info_str, "(version unknown)");
#endif /* ZLIB_VERSION */
#else /* HAVE_LIBZ */
  g_string_append(comp_info_str, ", without libz");
#endif /* HAVE_LIBZ */

/* Oh, this is pretty */
#ifdef HAVE_UCD_SNMP
  g_string_append(comp_info_str, ", with UCD SNMP ");
#ifdef HAVE_UCD_SNMP_VERSION_H
  g_string_append(comp_info_str, VersionInfo);
#else /* HAVE_UCD_SNMP_VERSION_H */
  g_string_append(comp_info_str, "(version unknown)");
#endif /* HAVE_UCD_SNMP_VERSION_H */
#else /* no SNMP library */
  g_string_append(comp_info_str, ", without UCD SNMP");
#endif
    
  /* Now get our args */
  while ((opt = getopt(argc, argv, "a:b:c:Df:F:hi:lnN:o:pqr:R:s:t:vw:Vx")) != -1) {
    switch (opt) {
      case 'a':        /* autostop criteria */
#ifdef HAVE_LIBPCAP
        if (set_autostop_criterion(optarg) == FALSE) {
          fprintf(stderr, "ethereal: Invalid or unknown -a flag \"%s\"\n", optarg);
          exit(1);          
        }
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 'b':        /* Ringbuffer option */
#ifdef HAVE_LIBPCAP
        capture_opts.ringbuffer_on = TRUE;
        capture_opts.ringbuffer_num_files =
            get_positive_int(optarg, "number of ring buffer files");
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 'c':        /* Capture xxx packets */
#ifdef HAVE_LIBPCAP
        capture_opts.autostop_count =
            get_positive_int(optarg, "packet count");
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 'D':        /* Print a list of capture devices */
#ifdef HAVE_LIBPCAP
        if_list = get_interface_list(&err, err_str);
        if (if_list == NULL) {
            switch (err) {

            case CANT_GET_INTERFACE_LIST:
                fprintf(stderr, "tethereal: Can't get list of interfaces: %s\n",
			err_str);
                break;

            case NO_INTERFACES_FOUND:
                fprintf(stderr, "tethereal: There are no interfaces on which a capture can be done\n");
                break;
            }
            exit(2);
        }
        for (if_entry = g_list_first(if_list); if_entry != NULL;
		if_entry = g_list_next(if_entry))
          printf("%s\n", (char *)if_entry->data);
        free_interface_list(if_list);
        exit(0);
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 'f':
#ifdef HAVE_LIBPCAP
        capture_filter_specified = TRUE;
	if (cfile.cfilter)
		g_free(cfile.cfilter);
	cfile.cfilter = g_strdup(optarg);
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
	break;
      case 'F':
        out_file_type = wtap_short_string_to_file_type(optarg);
        if (out_file_type < 0) {
          fprintf(stderr, "tethereal: \"%s\" is not a valid capture file type\n",
			optarg);
          exit(1);
        }
        break;
      case 'h':        /* Print help and exit */
	print_usage(TRUE);
	exit(0);
        break;
      case 'i':        /* Use interface xxx */
#ifdef HAVE_LIBPCAP
        cfile.iface = g_strdup(optarg);
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 'l':        /* "Line-buffer" standard output */
	/* This isn't line-buffering, strictly speaking, it's just
	   flushing the standard output after the information for
	   each packet is printed; however, that should be good
	   enough for all the purposes to which "-l" is put.

	   See the comment in "wtap_dispatch_cb_print()" for an
	   explanation of why we do that, and why we don't just
	   use "setvbuf()" to make the standard output line-buffered
	   (short version: in Windows, "line-buffered" is the same
	   as "fully-buffered", and the output buffer is only flushed
	   when it fills up). */
	line_buffered = TRUE;
	break;
      case 'n':        /* No name resolution */
        g_resolv_flags = RESOLV_NONE;
        break;
      case 'N':        /* Select what types of addresses/port #s to resolve */
        if (g_resolv_flags == RESOLV_ALL)
          g_resolv_flags = RESOLV_NONE;
        badopt = string_to_name_resolve(optarg, &g_resolv_flags);
        if (badopt != '\0') {
          fprintf(stderr, "tethereal: -N specifies unknown resolving option '%c'; valid options are 'm', 'n', and 't'\n",
			badopt);
          exit(1);
        }
        break;
      case 'o':        /* Override preference from command line */
        switch (prefs_set_pref(optarg)) {

	case PREFS_SET_SYNTAX_ERR:
          fprintf(stderr, "tethereal: Invalid -o flag \"%s\"\n", optarg);
          exit(1);
          break;

        case PREFS_SET_NO_SUCH_PREF:
        case PREFS_SET_OBSOLETE:
          fprintf(stderr, "tethereal: -o flag \"%s\" specifies unknown preference\n",
			optarg);
          exit(1);
          break;
        }
        break;
      case 'p':        /* Don't capture in promiscuous mode */
#ifdef HAVE_LIBPCAP
	capture_opts.promisc_mode = FALSE;
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
	break;
      case 'q':        /* Quiet */
        quiet = TRUE;
        break;
      case 'r':        /* Read capture file xxx */
        cf_name = g_strdup(optarg);
        break;
      case 'R':        /* Read file filter */
        rfilter = optarg;
        break;
      case 's':        /* Set the snapshot (capture) length */
#ifdef HAVE_LIBPCAP
        capture_opts.snaplen = get_positive_int(optarg, "snapshot length");
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 't':        /* Time stamp type */
        if (strcmp(optarg, "r") == 0)
          timestamp_type = RELATIVE;
        else if (strcmp(optarg, "a") == 0)
          timestamp_type = ABSOLUTE;
        else if (strcmp(optarg, "ad") == 0)
          timestamp_type = ABSOLUTE_WITH_DATE;
        else if (strcmp(optarg, "d") == 0)
          timestamp_type = DELTA;
        else {
          fprintf(stderr, "tethereal: Invalid time stamp type \"%s\"\n",
            optarg);
          fprintf(stderr, "It must be \"r\" for relative, \"a\" for absolute,\n");
          fprintf(stderr, "\"ad\" for absolute with date, or \"d\" for delta.\n");
          exit(1);
        }
        break;
      case 'v':        /* Show version and exit */
        printf("t%s %s, %s\n", PACKAGE, VERSION, comp_info_str->str);
        exit(0);
        break;
      case 'w':        /* Write to capture file xxx */
        cfile.save_file = g_strdup(optarg);
	break;
      case 'V':        /* Verbose */
        verbose = TRUE;
        break;
      case 'x':        /* Print packet data in hex (and ASCII) */
        print_hex = TRUE;
        break;
      default:
      case '?':        /* Bad flag - print usage message */
        arg_error = TRUE;
        break;
    }
  }
  
  /* If no capture filter or read filter has been specified, and there are
     still command-line arguments, treat them as the tokens of a capture
     filter (if no "-r" flag was specified) or a read filter (if a "-r"
     flag was specified. */
  if (optind < argc) {
    if (cf_name != NULL) {
      if (rfilter != NULL) {
        fprintf(stderr,
"tethereal: Read filters were specified both with \"-R\" and with additional command-line arguments\n");
        exit(2);
      }
      rfilter = get_args_as_string(argc, argv, optind);
    } else {
#ifdef HAVE_LIBPCAP
      if (capture_filter_specified) {
        fprintf(stderr,
"tethereal: Capture filters were specified both with \"-f\" and with additional command-line arguments\n");
        exit(2);
      }
      cfile.cfilter = get_args_as_string(argc, argv, optind);
#else
      capture_option_specified = TRUE;
#endif
    }
  }

  /* See if we're writing a capture file and the file is a pipe */
#ifdef HAVE_LIBPCAP
  ld.output_to_pipe = FALSE;
#endif
  if (cfile.save_file != NULL) {
    if (!strcmp(cfile.save_file, "-")) {
      /* stdout */
      g_free(cfile.save_file);
      cfile.save_file = g_strdup("");
#ifdef HAVE_LIBPCAP
      ld.output_to_pipe = TRUE;
#endif
    }
#ifdef HAVE_LIBPCAP
    else {
      err = test_for_fifo(cfile.save_file);
      switch (err) {
  
      case ENOENT:	/* it doesn't exist, so we'll be creating it,
      			   and it won't be a FIFO */
      case 0:		/* found it, but it's not a FIFO */
        break;
  
      case ESPIPE:	/* it is a FIFO */
        ld.output_to_pipe = TRUE;
        break;
  
      default:		/* couldn't stat it */
        fprintf(stderr,
                "tethereal: Error testing whether capture file is a pipe: %s\n",
                strerror(errno));
        exit(2);
      }
    }
#endif
  }

#ifdef HAVE_LIBPCAP
  /* If they didn't specify a "-w" flag, but specified a maximum capture
     file size, tell them that this doesn't work, and exit. */
  if (capture_opts.has_autostop_filesize && cfile.save_file == NULL) {
    fprintf(stderr, "tethereal: Maximum capture file size specified, but "
      "capture isn't being saved to a file.\n");
    exit(2);
  }

  if (capture_opts.ringbuffer_on) {
    /* Ring buffer works only under certain conditions:
       a) ring buffer does not work if you're not saving the capture to
          a file;
       b) ring buffer only works if you're saving in libpcap format;
       c) it makes no sense to enable the ring buffer if the maximum
          file size is set to "infinite";
       d) file must not be a pipe. */
    if (cfile.save_file == NULL) {
      fprintf(stderr, "tethereal: Ring buffer requested, but "
        "capture isn't being saved to a file.\n");
      exit(2);
    }
    if (out_file_type != WTAP_FILE_PCAP) {
      fprintf(stderr, "tethereal: Ring buffer requested, but "
        "capture isn't being saved in libpcap format.\n");
      exit(2);
    }
    if (!capture_opts.has_autostop_filesize) {
      fprintf(stderr, "tethereal: Ring buffer requested, but "
        "no maximum capture file size was specified.\n");
      exit(2);
    }
    if (ld.output_to_pipe) {
      fprintf(stderr, "tethereal: Ring buffer requested, but "
        "capture file is a pipe.\n");
      exit(2);
    }
  }
#endif

#ifdef WIN32
  /* Start windows sockets */
  WSAStartup( MAKEWORD( 1, 1 ), &wsaData );
#endif

  /* Notify all registered modules that have had any of their preferences
     changed either from one of the preferences file or from the command
     line that their preferences have changed. */
  prefs_apply_all();

#ifndef HAVE_LIBPCAP
  if (capture_option_specified)
    fprintf(stderr, "This version of Tethereal was not built with support for capturing packets.\n");
#endif
  if (arg_error) {
    print_usage(FALSE);
    exit(1);
  }

  /* Build the column format array */  
  col_init(&cfile.cinfo, prefs->num_cols);
  for (i = 0; i < cfile.cinfo.num_cols; i++) {
    cfile.cinfo.col_fmt[i] = get_column_format(i);
    cfile.cinfo.col_title[i] = g_strdup(get_column_title(i));
    cfile.cinfo.fmt_matx[i] = (gboolean *) g_malloc0(sizeof(gboolean) *
      NUM_COL_FMTS);
    get_column_format_matches(cfile.cinfo.fmt_matx[i], cfile.cinfo.col_fmt[i]);
    cfile.cinfo.col_data[i] = NULL;
    if (cfile.cinfo.col_fmt[i] == COL_INFO)
      cfile.cinfo.col_buf[i] = (gchar *) g_malloc(sizeof(gchar) * COL_MAX_INFO_LEN);
    else
      cfile.cinfo.col_buf[i] = (gchar *) g_malloc(sizeof(gchar) * COL_MAX_LEN);

    cfile.cinfo.col_expr[i] = (gchar *) g_malloc(sizeof(gchar) * COL_MAX_LEN);
    cfile.cinfo.col_expr_val[i] = (gchar *) g_malloc(sizeof(gchar) * COL_MAX_LEN);
  }

#ifdef HAVE_LIBPCAP
  if (capture_opts.snaplen < 1)
    capture_opts.snaplen = WTAP_MAX_PACKET_SIZE;
  else if (capture_opts.snaplen < MIN_PACKET_SIZE)
    capture_opts.snaplen = MIN_PACKET_SIZE;
  
  /* Check the value range of the ringbuffer_num_files parameter */
  if (capture_opts.ringbuffer_num_files < RINGBUFFER_MIN_NUM_FILES)
    capture_opts.ringbuffer_num_files = RINGBUFFER_MIN_NUM_FILES;
  else if (capture_opts.ringbuffer_num_files > RINGBUFFER_MAX_NUM_FILES)
    capture_opts.ringbuffer_num_files = RINGBUFFER_MAX_NUM_FILES;
#endif
  
  if (rfilter != NULL) {
    if (!dfilter_compile(rfilter, &rfcode)) {
      fprintf(stderr, "tethereal: %s\n", dfilter_error_msg);
      epan_cleanup();
      exit(2);
    }
  }
  cfile.rfcode = rfcode;
  if (cf_name) {
    err = open_cap_file(cf_name, FALSE, &cfile);
    if (err != 0) {
      epan_cleanup();
      exit(2);
    }
    err = load_cap_file(&cfile, out_file_type);
    if (err != 0) {
      epan_cleanup();
      exit(2);
    }
    cf_name[0] = '\0';
  } else {
    /* No capture file specified, so we're supposed to do a live capture;
       do we have support for live captures? */
#ifdef HAVE_LIBPCAP

#ifdef _WIN32
    if (!has_wpcap) {
	fprintf(stderr, "tethereal: Could not load wpcap.dll.\n");
	exit(2);
    }
#endif

    /* Yes; did the user specify an interface to use? */
    if (cfile.iface == NULL) {
        /* No - is a default specified in the preferences file? */
        if (prefs->capture_device != NULL) {
            /* Yes - use it. */
	    if_text = strrchr(prefs->capture_device, ' ');
	    if (if_text == NULL) {
            	cfile.iface = g_strdup(prefs->capture_device);
	    } else {
            	cfile.iface = g_strdup(if_text + 1); /* Skip over space */
	    }
        } else {
            /* No - pick the first one from the list of interfaces. */
            if_list = get_interface_list(&err, err_str);
            if (if_list == NULL) {
                switch (err) {

                case CANT_GET_INTERFACE_LIST:
                    fprintf(stderr, "tethereal: Can't get list of interfaces: %s\n",
			    err_str);
                    break;

                case NO_INTERFACES_FOUND:
                    fprintf(stderr, "tethereal: There are no interfaces on which a capture can be done\n");
                    break;
                }
                exit(2);
            }
	    if_text = strrchr(if_list->data, ' ');	/* first interface */
	    if (if_text == NULL) {
            	cfile.iface = g_strdup(if_list->data);
	    } else {
            	cfile.iface = g_strdup(if_text + 1); /* Skip over space */
	    }
            free_interface_list(if_list);
        }
    }
    capture(out_file_type);

    if (capture_opts.ringbuffer_on) {
      ringbuf_free();
    }
#else
    /* No - complain. */
    fprintf(stderr, "This version of Tethereal was not built with support for capturing packets.\n");
    exit(2);
#endif
  }

  epan_cleanup();

  return 0;
}

#ifdef HAVE_LIBPCAP
/* Do the low-level work of a capture.
   Returns TRUE if it succeeds, FALSE otherwise. */
static int
capture(int out_file_type)
{
  gchar       open_err_str[PCAP_ERRBUF_SIZE];
  gchar       lookup_net_err_str[PCAP_ERRBUF_SIZE];
  bpf_u_int32 netnum, netmask;
  struct bpf_program fcode;
  void        (*oldhandler)(int);
  int         err = 0;
  int         volatile volatile_err = 0;
  int         volatile inpkts = 0;
  int         pcap_cnt;
  char        errmsg[1024+1];
  condition  *volatile cnd_stop_capturesize = NULL;
  condition  *volatile cnd_stop_timeout = NULL;
#ifndef _WIN32
  static const char ppamsg[] = "can't find PPA for ";
  char       *libpcap_warn;
#endif
  struct pcap_stat stats;
  gboolean    write_err;
  gboolean    dump_ok;

  /* Initialize all data structures used for dissection. */
  init_dissection();

  ld.linktype       = WTAP_ENCAP_UNKNOWN;
  ld.pdh            = NULL;

  /* Open the network interface to capture from it.
     Some versions of libpcap may put warnings into the error buffer
     if they succeed; to tell if that's happened, we have to clear
     the error buffer, and check if it's still a null string.  */
  open_err_str[0] = '\0';
  ld.pch = pcap_open_live(cfile.iface, capture_opts.snaplen,
			  capture_opts.promisc_mode, 1000, open_err_str);

  if (ld.pch == NULL) {
    /* Well, we couldn't start the capture. */
#ifdef _WIN32
    /* On Win32 OSes, the capture devices are probably available to all
       users; don't warn about permissions problems.

       Do, however, warn that Token Ring and PPP devices aren't supported. */
    snprintf(errmsg, sizeof errmsg,
	"The capture session could not be initiated (%s).\n"
	"Please check that you have the proper interface specified.\n"
	"\n"
	"Note that the driver Tethereal uses for packet capture on Windows\n"
	"doesn't support capturing on Token Ring interfaces, and doesn't\n"
	"support capturing on PPP/WAN interfaces in Windows NT/2000.\n",
	open_err_str);
#else
      /* If we got a "can't find PPA for XXX" message, warn the user (who
         is running Ethereal on HP-UX) that they don't have a version
	 of libpcap that properly handles HP-UX (libpcap 0.6.x and later
	 versions, which properly handle HP-UX, say "can't find /dev/dlpi
	 PPA for XXX" rather than "can't find PPA for XXX"). */
      if (strncmp(open_err_str, ppamsg, sizeof ppamsg - 1) == 0)
	libpcap_warn =
	  "\n\n"
	  "You are running Tethereal with a version of the libpcap library\n"
	  "that doesn't handle HP-UX network devices well; this means that\n"
	  "Tethereal may not be able to capture packets.\n"
	  "\n"
	  "To fix this, you should install libpcap 0.6.2, or a later version\n"
	  "of libpcap, rather than libpcap 0.4 or 0.5.x.  It is available in\n"
	  "packaged binary form from the Software Porting And Archive Centre\n"
	  "for HP-UX; the Centre is at http://hpux.connect.org.uk/ - the page\n"
	  "at the URL lists a number of mirror sites.";
      else
	libpcap_warn = "";
    snprintf(errmsg, sizeof errmsg,
      "The capture session could not be initiated (%s).\n"
      "Please check to make sure you have sufficient permissions, and that\n"
      "you have the proper interface specified.%s", open_err_str, libpcap_warn);
#endif
    goto error;
  }

  if (cfile.cfilter) {
    /* A capture filter was specified; set it up. */
    if (pcap_lookupnet(cfile.iface, &netnum, &netmask, lookup_net_err_str) < 0) {
      /*
       * Well, we can't get the netmask for this interface; it's used
       * only for filters that check for broadcast IP addresses, so
       * we just warn the user, and punt and use 0.
       */
      fprintf(stderr, 
        "Warning:  Couldn't obtain netmask info (%s).\n", lookup_net_err_str);
      netmask = 0;
    }
    if (pcap_compile(ld.pch, &fcode, cfile.cfilter, 1, netmask) < 0) {
      snprintf(errmsg, sizeof errmsg, "Unable to parse filter string (%s).",
	pcap_geterr(ld.pch));
      goto error;
    }
    if (pcap_setfilter(ld.pch, &fcode) < 0) {
      snprintf(errmsg, sizeof errmsg, "Can't install filter (%s).",
	pcap_geterr(ld.pch));
      goto error;
    }
  }

  ld.linktype = wtap_pcap_encap_to_wtap_encap(get_pcap_linktype(ld.pch,
	cfile.iface));
  if (cfile.save_file != NULL) {
    /* Set up to write to the capture file. */
    if (ld.linktype == WTAP_ENCAP_UNKNOWN) {
      strcpy(errmsg, "The network you're capturing from is of a type"
               " that Tethereal doesn't support.");
      goto error;
    }
    if (capture_opts.ringbuffer_on) {
      cfile.save_file_fd = ringbuf_init(cfile.save_file,
        capture_opts.ringbuffer_num_files);
      if (cfile.save_file_fd != -1) {
        ld.pdh = ringbuf_init_wtap_dump_fdopen(out_file_type, ld.linktype,
          pcap_snapshot(ld.pch), &err);
      } else {
      	err = errno;	/* "ringbuf_init()" failed */
        ld.pdh = NULL;
      }
    } else {
      ld.pdh = wtap_dump_open(cfile.save_file, out_file_type,
		 ld.linktype, pcap_snapshot(ld.pch), &err);
    }

    if (ld.pdh == NULL) {
      snprintf(errmsg, sizeof errmsg,
	       file_open_error_message(err, TRUE, out_file_type),
	       *cfile.save_file == '\0' ? "stdout" : cfile.save_file);
      goto error;
    }
  }

  /* Does "open_err_str" contain a non-empty string?  If so, "pcap_open_live()"
     returned a warning; print it, but keep capturing. */
  if (open_err_str[0] != '\0')
    fprintf(stderr, "tethereal: WARNING: %s.\n", open_err_str);

#ifdef _WIN32
  /* Catch a CTRL+C event and, if we get it, clean up and exit. */
  SetConsoleCtrlHandler(capture_cleanup, TRUE);
#else /* _WIN32 */
  /* Catch SIGINT and SIGTERM and, if we get either of them, clean up
     and exit.
     XXX - deal with signal semantics on various UNIX platforms.  Or just
     use "sigaction()" and be done with it? */
  signal(SIGTERM, capture_cleanup);
  signal(SIGINT, capture_cleanup);
  if ((oldhandler = signal(SIGHUP, capture_cleanup)) != SIG_DFL)
    signal(SIGHUP, oldhandler);
#endif /* _WIN32 */

  /* Let the user know what interface was chosen. */
  fprintf(stderr, "Capturing on %s\n", cfile.iface);

  /* initialize capture stop conditions */ 
  init_capture_stop_conditions();
  /* create stop conditions */
  if (capture_opts.has_autostop_filesize)
    cnd_stop_capturesize = cnd_new((char*)CND_CLASS_CAPTURESIZE,
                                   (long)capture_opts.autostop_filesize * 1000);
  if (capture_opts.has_autostop_duration)
    cnd_stop_timeout = cnd_new((char*)CND_CLASS_TIMEOUT,
                               (gint32)capture_opts.autostop_duration);

  if (!setjmp(ld.stopenv))
    ld.go = TRUE;
  else
    ld.go = FALSE;
  ld.packet_count = 0;
  while (ld.go) {
    /* We need to be careful with automatic variables defined in the
       outer scope which are changed inside the loop.  Most compilers
       don't try to roll them back to their original values after the
       longjmp which causes the loop to finish, but all that the
       standards say is that their values are indeterminate.  If we
       don't want them to be rolled back, we should define them with the
       volatile attribute (paraphrasing W. Richard Stevens, Advanced
       Programming in the UNIX Environment, p. 178).

       The "err" variable causes a particular problem.  If we give it
       the volatile attribute, then when we pass a reference to it (as
       in "&err") to a function, GCC warns: "passing arg <n> of
       <function> discards qualifiers from pointer target type".
       Therefore within the loop and just beyond we don't use "err".
       Within the loop we define "loop_err", and assign its value to
       "volatile_err", which is in the outer scope and is checked when
       the loop finishes.

       We also define "packet_count_prev" here to keep things tidy,
       since it's used only inside the loop.  If it were defined in the
       outer scope, GCC would give a warning (unnecessary in this case)
       that it might be clobbered, and we'd need to give it the volatile
       attribute to suppress the warning. */

    int loop_err = 0;
    int packet_count_prev = 0;

    if (cnd_stop_capturesize == NULL && cnd_stop_timeout == NULL) {
      /* We're not stopping at a particular capture file size, and we're
         not stopping after some particular amount of time has expired,
         so either we have no stop condition or the only stop condition
         is a maximum packet count.

         If there's no maximum packet count, pass it -1, meaning "until
         you run out of packets in the bufferful you read".  Otherwise,
         pass it the number of packets we have left to capture.

         We don't call "pcap_loop()" as, if we're saving to a file that's
         a FIFO, we want to flush the FIFO after we're done processing
         this libpcap bufferful of packets, so that the program
         reading the FIFO sees the packets immediately and doesn't get
         any partial packet, forcing it to block in the middle of reading
         that packet. */
      if (capture_opts.autostop_count == 0)
        pcap_cnt = -1;
      else {
        if (ld.packet_count >= capture_opts.autostop_count) {
          /* XXX do we need this test here? */
          /* It appears there's nothing more to capture. */
          break;
        }
        pcap_cnt = capture_opts.autostop_count - ld.packet_count;
      }
    } else {
      /* We need to check the capture file size or the timeout after
         each packet. */
      pcap_cnt = 1;
    }
    inpkts = pcap_dispatch(ld.pch, pcap_cnt, capture_pcap_cb, (guchar *) &ld);
    if (inpkts < 0) {
      /* Error from "pcap_dispatch()". */
      ld.go = FALSE;
    } else if (cnd_stop_timeout != NULL && cnd_eval(cnd_stop_timeout)) {
      /* The specified capture time has elapsed; stop the capture. */
      ld.go = FALSE;
    } else if (inpkts > 0) {
      if (capture_opts.autostop_count != 0 &&
                 ld.packet_count >= capture_opts.autostop_count) {
        /* The specified number of packets have been captured and have
           passed both any capture filter in effect and any read filter
           in effect. */
        ld.go = FALSE;
      } else if (cnd_stop_capturesize != NULL &&
                    cnd_eval(cnd_stop_capturesize, 
                              (guint32)wtap_get_bytes_dumped(ld.pdh))) {
        /* We're saving the capture to a file, and the capture file reached
           its maximum size. */
        if (capture_opts.ringbuffer_on) {
          /* Switch to the next ringbuffer file */
          if (ringbuf_switch_file(&cfile, &ld.pdh, &loop_err)) {
            /* File switch succeeded: reset the condition */
            cnd_reset(cnd_stop_capturesize);
          } else {
            /* File switch failed: stop here */
            volatile_err = loop_err;
            ld.go = FALSE;
          }
        } else {
          /* No ringbuffer - just stop. */
          ld.go = FALSE;
        }
      }
      if (ld.output_to_pipe) {
        if (ld.packet_count > packet_count_prev) {
          if (fflush(wtap_dump_file(ld.pdh))) {
            volatile_err = errno;
            ld.go = FALSE;
          }
          packet_count_prev = ld.packet_count;
        }
      }
    } /* inpkts > 0 */
  } /* while (ld.go) */
  
  /* delete stop conditions */
  if (cnd_stop_capturesize != NULL)
    cnd_delete(cnd_stop_capturesize);
  if (cnd_stop_timeout != NULL)
    cnd_delete(cnd_stop_timeout);

  if ((cfile.save_file != NULL) && !quiet) {
    /* We're saving to a file, which means we're printing packet counts
       to stderr if we are not running silent and deep.
       Send a newline so that we move to the line after the packet count. */
    fprintf(stderr, "\n");
  }

  /* If we got an error while capturing, report it. */
  if (inpkts < 0) {
    fprintf(stderr, "tethereal: Error while capturing packets: %s\n",
	pcap_geterr(ld.pch));
  }

  if (volatile_err == 0)
    write_err = FALSE;
  else {
    show_capture_file_io_error(cfile.save_file, volatile_err, FALSE);
    write_err = TRUE;
  }

  if (cfile.save_file != NULL) {
    /* We're saving to a file or files; close all files. */
    if (capture_opts.ringbuffer_on) {
      dump_ok = ringbuf_wtap_dump_close(&cfile, &err);
    } else {
      dump_ok = wtap_dump_close(ld.pdh, &err);
    }
    /* If we've displayed a message about a write error, there's no point
       in displaying another message about an error on close. */
    if (!dump_ok && !write_err)
      show_capture_file_io_error(cfile.save_file, err, TRUE);
  }

  /* Get the capture statistics, and, if any packets were dropped, report
     that. */
  if (pcap_stats(ld.pch, &stats) >= 0) {
    if (stats.ps_drop != 0) {
      fprintf(stderr, "%u packets dropped\n", stats.ps_drop);
    }
  } else {
    fprintf(stderr, "tethereal: Can't get packet-drop statistics: %s\n",
	pcap_geterr(ld.pch));
  }
  /* Report the number of captured packets if not reported during capture
     and we are saving to a file. */
  if (quiet && (cfile.save_file != NULL)) {
    fprintf(stderr, "%u packets captured\n", ld.packet_count);
  }

  pcap_close(ld.pch);

  return TRUE;

error:
  if (capture_opts.ringbuffer_on) {
    ringbuf_error_cleanup();
  }
  g_free(cfile.save_file);
  cfile.save_file = NULL;
  fprintf(stderr, "tethereal: %s\n", errmsg);
  if (ld.pch != NULL)
    pcap_close(ld.pch);

  return FALSE;
}

static void
capture_pcap_cb(guchar *user, const struct pcap_pkthdr *phdr,
  const guchar *pd)
{
  struct wtap_pkthdr whdr;
  union wtap_pseudo_header pseudo_header;
  loop_data *ld = (loop_data *) user;
  cb_args_t args;
  int err;

  /* Convert from libpcap to Wiretap format.
     If that fails, ignore the packet (wtap_process_pcap_packet has
     written an error message). */
  pd = wtap_process_pcap_packet(ld->linktype, phdr, pd, &pseudo_header,
				&whdr, &err);
  if (pd == NULL) {
    return;
  }

  args.cf = &cfile;
  args.pdh = ld->pdh;
  if (ld->pdh) {
    wtap_dispatch_cb_write((guchar *)&args, &whdr, 0, &pseudo_header, pd);
    /* Report packet capture count if not quiet */
    if (!quiet) {
      if (ld->packet_count != 0) {
        fprintf(stderr, "\r%u ", ld->packet_count);
        /* stderr could be line buffered */
        fflush(stderr);
      }
    }
  } else {
    wtap_dispatch_cb_print((guchar *)&args, &whdr, 0, &pseudo_header, pd);
  }
}

#ifdef _WIN32
static BOOL WINAPI
capture_cleanup(DWORD ctrltype _U_)
{
  /* CTRL_C_EVENT is sort of like SIGINT, CTRL_BREAK_EVENT is unique to
     Windows, CTRL_CLOSE_EVENT is sort of like SIGHUP, CTRL_LOGOFF_EVENT
     is also sort of like SIGHUP, and CTRL_SHUTDOWN_EVENT is sort of
     like SIGTERM at least when the machine's shutting down.

     For now, we handle them all as indications that we should clean up
     and quit, just as we handle SIGINT, SIGHUP, and SIGTERM in that
     way on UNIX.

     However, as handlers run in a new thread, we can't just longjmp
     out; we have to set "ld.go" to FALSE, and must return TRUE so that
     no other handler - such as one that would terminate the process -
     gets called.

     XXX - for some reason, typing ^C to Tethereal, if you run this in
     a Cygwin console window in at least some versions of Cygwin,
     causes Tethereal to terminate immediately; this routine gets
     called, but the main loop doesn't get a chance to run and
     exit cleanly, at least if this is compiled with Microsoft Visual
     C++ (i.e., it's a property of the Cygwin console window or Bash;
     it happens if Tethereal is not built with Cygwin - for all I know,
     building it with Cygwin may make the problem go away). */
  ld.go = FALSE;
  return TRUE;
}
#else
static void
capture_cleanup(int signum _U_)
{
  /* Longjmp back to the starting point; "pcap_dispatch()", on many
     UNIX platforms, just keeps looping if it gets EINTR, so if we set
     "ld.go" to FALSE and return, we won't break out of it and quit
     capturing. */
  longjmp(ld.stopenv, 1);
}
#endif /* _WIN32 */
#endif /* HAVE_LIBPCAP */

static int
load_cap_file(capture_file *cf, int out_file_type)
{
  gint         linktype;
  int          snapshot_length;
  wtap_dumper *pdh;
  int          err;
  int          success;
  cb_args_t    args;

  linktype = wtap_file_encap(cf->wth);
  if (cf->save_file != NULL) {
    /* Set up to write to the capture file. */
    snapshot_length = wtap_snapshot_length(cf->wth);
    if (snapshot_length == 0) {
      /* Snapshot length of input file not known. */
      snapshot_length = WTAP_MAX_PACKET_SIZE;
    }
    pdh = wtap_dump_open(cf->save_file, out_file_type,
		linktype, snapshot_length, &err);

    if (pdh == NULL) {
      /* We couldn't set up to write to the capture file. */
      switch (err) {

      case WTAP_ERR_UNSUPPORTED_FILE_TYPE:
        fprintf(stderr,
		"tethereal: Capture files can't be written in that format.\n");
        break;

      case WTAP_ERR_UNSUPPORTED_ENCAP:
      case WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED:
        fprintf(stderr,
          "tethereal: The capture file being read cannot be written in "
          "that format.\n");
        break;

      case WTAP_ERR_CANT_OPEN:
        fprintf(stderr,
          "tethereal: The file \"%s\" couldn't be created for some "
          "unknown reason.\n",
            *cf->save_file == '\0' ? "stdout" : cf->save_file);
        break;

      case WTAP_ERR_SHORT_WRITE:
        fprintf(stderr,
          "tethereal: A full header couldn't be written to the file \"%s\".\n",
		*cf->save_file == '\0' ? "stdout" : cf->save_file);
        break;

      default:
        fprintf(stderr,
          "tethereal: The file \"%s\" could not be created: %s\n.",
 		*cf->save_file == '\0' ? "stdout" : cf->save_file,
		wtap_strerror(err));
        break;
      }
      goto out;
    }
    args.cf = cf;
    args.pdh = pdh;
    success = wtap_loop(cf->wth, 0, wtap_dispatch_cb_write, (guchar *) &args,
 			&err);

    /* Now close the capture file. */
    if (!wtap_dump_close(pdh, &err))
      show_capture_file_io_error(cfile.save_file, err, TRUE);
  } else {
    args.cf = cf;
    args.pdh = NULL;
    success = wtap_loop(cf->wth, 0, wtap_dispatch_cb_print, (guchar *) &args,
 			&err);
  }
  if (!success) {
    /* Print up a message box noting that the read failed somewhere along
       the line. */
    switch (err) {

    case WTAP_ERR_UNSUPPORTED_ENCAP:
      fprintf(stderr,
"tethereal: \"%s\" is a capture file is for a network type that Tethereal doesn't support.\n",
	cf->filename);
      break;

    case WTAP_ERR_CANT_READ:
      fprintf(stderr,
"tethereal: An attempt to read from \"%s\" failed for some unknown reason.\n",
	cf->filename);
      break;

    case WTAP_ERR_SHORT_READ:
      fprintf(stderr,
"tethereal: \"%s\" appears to have been cut short in the middle of a packet.\n",
	cf->filename);
      break;

    case WTAP_ERR_BAD_RECORD:
      fprintf(stderr,
"tethereal: \"%s\" appears to be damaged or corrupt.\n",
	cf->filename);
      break;

    default:
      fprintf(stderr,
"tethereal: An error occurred while reading \"%s\": %s.\n",
	cf->filename, wtap_strerror(err));
      break;
    }
  }

out:
  wtap_close(cf->wth);
  cf->wth = NULL;

  return err;
}

static void
fill_in_fdata(frame_data *fdata, capture_file *cf,
	const struct wtap_pkthdr *phdr, long offset)
{
  fdata->next = NULL;
  fdata->prev = NULL;
  fdata->pfd = NULL;
  fdata->num = cf->count;
  fdata->pkt_len = phdr->len;
  fdata->cap_len = phdr->caplen;
  fdata->file_off = offset;
  fdata->lnk_t = phdr->pkt_encap;
  fdata->abs_secs  = phdr->ts.tv_sec;
  fdata->abs_usecs = phdr->ts.tv_usec;
  fdata->flags.passed_dfilter = 0;
  fdata->flags.encoding = CHAR_ASCII;
  fdata->flags.visited = 0;
  fdata->flags.marked = 0;

  /* If we don't have the time stamp of the first packet in the
     capture, it's because this is the first packet.  Save the time
     stamp of this packet as the time stamp of the first packet. */
  if (!firstsec && !firstusec) {
    firstsec  = fdata->abs_secs;
    firstusec = fdata->abs_usecs;
  }

  /* If we don't have the time stamp of the previous displayed packet,
     it's because this is the first displayed packet.  Save the time
     stamp of this packet as the time stamp of the previous displayed
     packet. */
  if (!prevsec && !prevusec) {
    prevsec  = fdata->abs_secs;
    prevusec = fdata->abs_usecs;
  }

  /* Get the time elapsed between the first packet and this packet. */
  compute_timestamp_diff(&fdata->rel_secs, &fdata->rel_usecs,
		fdata->abs_secs, fdata->abs_usecs, firstsec, firstusec);

  /* If it's greater than the current elapsed time, set the elapsed time
     to it (we check for "greater than" so as not to be confused by
     time moving backwards). */
  if ((gint32)cf->esec < fdata->rel_secs
	|| ((gint32)cf->esec == fdata->rel_secs && (gint32)cf->eusec < fdata->rel_usecs)) {
    cf->esec = fdata->rel_secs;
    cf->eusec = fdata->rel_usecs;
  }
  
  /* Get the time elapsed between the previous displayed packet and
     this packet. */
  compute_timestamp_diff(&fdata->del_secs, &fdata->del_usecs,
		fdata->abs_secs, fdata->abs_usecs, prevsec, prevusec);
  prevsec = fdata->abs_secs;
  prevusec = fdata->abs_usecs;
}

/* Free up all data attached to a "frame_data" structure. */
static void
clear_fdata(frame_data *fdata)
{
  if (fdata->pfd)
    g_slist_free(fdata->pfd);
}

static void
wtap_dispatch_cb_write(guchar *user, const struct wtap_pkthdr *phdr,
  long offset, union wtap_pseudo_header *pseudo_header, const guchar *buf)
{
  cb_args_t    *args = (cb_args_t *) user;
  capture_file *cf = args->cf;
  wtap_dumper  *pdh = args->pdh;
  frame_data    fdata;
  int           err;
  gboolean      passed;
  epan_dissect_t *edt;

  cf->count++;
  if (cf->rfcode) {
    fill_in_fdata(&fdata, cf, phdr, offset);
    edt = epan_dissect_new(TRUE, FALSE);
    epan_dissect_prime_dfilter(edt, cf->rfcode);
    epan_dissect_run(edt, pseudo_header, buf, &fdata, NULL);
    passed = dfilter_apply_edt(cf->rfcode, edt);
  } else {
    passed = TRUE;
    edt = NULL;
  }
  if (passed) {
    /* The packet passed the read filter. */
#ifdef HAVE_LIBPCAP
    ld.packet_count++;
#endif
    if (!wtap_dump(pdh, phdr, pseudo_header, buf, &err)) {
#ifdef HAVE_LIBPCAP
      if (ld.pch != NULL && !quiet) {
      	/* We're capturing packets, so (if -q not specified) we're printing
           a count of packets captured; move to the line after the count. */
        fprintf(stderr, "\n");
      }
#endif
      show_capture_file_io_error(cf->save_file, err, FALSE);
#ifdef HAVE_LIBPCAP
      if (ld.pch != NULL)
        pcap_close(ld.pch);
#endif
      wtap_dump_close(pdh, &err);
      exit(2);
    }
  }
  if (edt != NULL)
    epan_dissect_free(edt);
  if (cf->rfcode)
    clear_fdata(&fdata);
}

static void
show_capture_file_io_error(const char *fname, int err, gboolean is_close)
{
  if (*fname == '\0')
    fname = "stdout";

  switch (err) {

  case ENOSPC:
    fprintf(stderr,
"tethereal: Not all the packets could be written to \"%s\" because there is "
"no space left on the file system.\n",
	fname);
    break;

#ifdef EDQUOT
  case EDQUOT:
    fprintf(stderr,
"tethereal: Not all the packets could be written to \"%s\" because you are "
"too close to, or over your disk quota.\n",
	fname);
  break;
#endif

  case WTAP_ERR_CANT_CLOSE:
    fprintf(stderr,
"tethereal: \"%s\" couldn't be closed for some unknown reason.\n",
	fname);
    break;

  case WTAP_ERR_SHORT_WRITE:
    fprintf(stderr,
"tethereal: Not all the packets could be written to \"%s\".\n",
	fname);
    break;

  default:
    if (is_close) {
      fprintf(stderr,
"tethereal: \"%s\" could not be closed: %s.\n",
	fname, wtap_strerror(err));
    } else {
      fprintf(stderr,
"tethereal: An error occurred while writing to \"%s\": %s.\n",
	fname, wtap_strerror(err));
    }
    break;
  }
}

static void
wtap_dispatch_cb_print(guchar *user, const struct wtap_pkthdr *phdr,
  long offset, union wtap_pseudo_header *pseudo_header, const guchar *buf)
{
  cb_args_t    *args = (cb_args_t *) user;
  capture_file *cf = args->cf;
  frame_data    fdata;
  gboolean      passed;
  print_args_t  print_args;
  epan_dissect_t *edt;
  gboolean      create_proto_tree;
  int           i;

  cf->count++;

  fill_in_fdata(&fdata, cf, phdr, offset);

  passed = TRUE;
  if (cf->rfcode || verbose)
    create_proto_tree = TRUE;
  else
    create_proto_tree = FALSE;
  /* The protocol tree will be "visible", i.e., printed, only if we're
     not printing a summary.

     We only need the columns if we're *not* verbose; in verbose mode,
     we print the protocol tree, not the protocol summary. */
  edt = epan_dissect_new(create_proto_tree, verbose);
  if (cf->rfcode) {
    epan_dissect_prime_dfilter(edt, cf->rfcode);
  }
  epan_dissect_run(edt, pseudo_header, buf, &fdata, verbose ? NULL : &cf->cinfo);
  if (cf->rfcode) {
    passed = dfilter_apply_edt(cf->rfcode, edt);
  }
  if (passed) {
    /* The packet passed the read filter. */
#ifdef HAVE_LIBPCAP
    ld.packet_count++;
#endif
    if (verbose) {
      /* Print the information in the protocol tree. */
      print_args.to_file = TRUE;
      print_args.format = PR_FMT_TEXT;
      print_args.print_summary = FALSE;
      print_args.print_hex = print_hex;
      print_args.expand_all = TRUE;
      print_args.suppress_unmarked = FALSE;
      proto_tree_print(&print_args, edt, stdout);
      if (!print_hex) {
        /* "print_hex_data()" will put out a leading blank line, as well
	   as a trailing one; print one here, to separate the packets,
	   only if "print_hex_data()" won't be called. */
        printf("\n");
      }
    } else {
      /* Just fill in the columns. */
      epan_dissect_fill_in_columns(edt);

      /* Now print them. */
      for (i = 0; i < cf->cinfo.num_cols; i++) {
        switch (cf->cinfo.col_fmt[i]) {
	case COL_NUMBER:
	  /*
	   * Don't print this if we're doing a live capture from a network
	   * interface - if we're doing a live capture, you won't be
	   * able to look at the capture in the future (it's not being
	   * saved anywhere), so the frame numbers are unlikely to be
	   * useful.
	   *
	   * (XXX - it might be nice to be able to save and print at
	   * the same time, sort of like an "Update list of packets
	   * in real time" capture in Ethereal.)
	   */
          if (cf->iface != NULL)
            continue;
          printf("%3s", cf->cinfo.col_data[i]);
          break;

        case COL_CLS_TIME:
        case COL_REL_TIME:
        case COL_ABS_TIME:
        case COL_ABS_DATE_TIME:	/* XXX - wider */
          printf("%10s", cf->cinfo.col_data[i]);
          break;

        case COL_DEF_SRC:
        case COL_RES_SRC:
        case COL_UNRES_SRC:
        case COL_DEF_DL_SRC:
        case COL_RES_DL_SRC:
        case COL_UNRES_DL_SRC:
        case COL_DEF_NET_SRC:
        case COL_RES_NET_SRC:
        case COL_UNRES_NET_SRC:
          printf("%12s", cf->cinfo.col_data[i]);
          break;

        case COL_DEF_DST:
        case COL_RES_DST:
        case COL_UNRES_DST:
        case COL_DEF_DL_DST:
        case COL_RES_DL_DST:
        case COL_UNRES_DL_DST:
        case COL_DEF_NET_DST:
        case COL_RES_NET_DST:
        case COL_UNRES_NET_DST:
          printf("%-12s", cf->cinfo.col_data[i]);
          break;

        default:
          printf("%s", cf->cinfo.col_data[i]);
          break;
        }
        if (i != cf->cinfo.num_cols - 1) {
          /*
	   * This isn't the last column, so we need to print a
	   * separator between this column and the next.
	   *
	   * If we printed a network source and are printing a
	   * network destination of the same type next, separate
	   * them with "->"; if we printed a network destination
	   * and are printing a network source of the same type
	   * next, separate them with "<-"; otherwise separate them
	   * with a space.
	   */
	  switch (cf->cinfo.col_fmt[i]) {

	  case COL_DEF_SRC:
	  case COL_RES_SRC:
	  case COL_UNRES_SRC:
	    switch (cf->cinfo.col_fmt[i + 1]) {

	    case COL_DEF_DST:
	    case COL_RES_DST:
	    case COL_UNRES_DST:
	      printf(" -> ");
	      break;

	    default:
	      putchar(' ');
	      break;
	    }
	    break;

	  case COL_DEF_DL_SRC:
	  case COL_RES_DL_SRC:
	  case COL_UNRES_DL_SRC:
	    switch (cf->cinfo.col_fmt[i + 1]) {

	    case COL_DEF_DL_DST:
	    case COL_RES_DL_DST:
	    case COL_UNRES_DL_DST:
	      printf(" -> ");
	      break;

	    default:
	      putchar(' ');
	      break;
	    }
	    break;

	  case COL_DEF_NET_SRC:
	  case COL_RES_NET_SRC:
	  case COL_UNRES_NET_SRC:
	    switch (cf->cinfo.col_fmt[i + 1]) {

	    case COL_DEF_NET_DST:
	    case COL_RES_NET_DST:
	    case COL_UNRES_NET_DST:
	      printf(" -> ");
	      break;

	    default:
	      putchar(' ');
	      break;
	    }
	    break;

	  case COL_DEF_DST:
	  case COL_RES_DST:
	  case COL_UNRES_DST:
	    switch (cf->cinfo.col_fmt[i + 1]) {

	    case COL_DEF_SRC:
	    case COL_RES_SRC:
	    case COL_UNRES_SRC:
	      printf(" <- ");
	      break;

	    default:
	      putchar(' ');
	      break;
	    }
	    break;

	  case COL_DEF_DL_DST:
	  case COL_RES_DL_DST:
	  case COL_UNRES_DL_DST:
	    switch (cf->cinfo.col_fmt[i + 1]) {

	    case COL_DEF_DL_SRC:
	    case COL_RES_DL_SRC:
	    case COL_UNRES_DL_SRC:
	      printf(" <- ");
	      break;

	    default:
	      putchar(' ');
	      break;
	    }
	    break;

	  case COL_DEF_NET_DST:
	  case COL_RES_NET_DST:
	  case COL_UNRES_NET_DST:
	    switch (cf->cinfo.col_fmt[i + 1]) {

	    case COL_DEF_NET_SRC:
	    case COL_RES_NET_SRC:
	    case COL_UNRES_NET_SRC:
	      printf(" <- ");
	      break;

	    default:
	      putchar(' ');
	      break;
	    }
	    break;

	  default:
	    putchar(' ');
	    break;
	  }
	}
      }
      putchar('\n');
    }
    if (print_hex) {
      print_hex_data(stdout, print_args.format, edt);
      putchar('\n');
    }
  }

  /* The ANSI C standard does not appear to *require* that a line-buffered
     stream be flushed to the host environment whenever a newline is
     written, it just says that, on such a stream, characters "are
     intended to be transmitted to or from the host environment as a
     block when a new-line character is encountered".

     The Visual C++ 6.0 C implementation doesn't do what is intended;
     even if you set a stream to be line-buffered, it still doesn't
     flush the buffer at the end of every line.

     So, if the "-l" flag was specified, we flush the standard output
     at the end of a packet.  This will do the right thing if we're
     printing packet summary lines, and, as we print the entire protocol
     tree for a single packet without waiting for anything to happen,
     it should be as good as line-buffered mode if we're printing
     protocol trees.  (The whole reason for the "-l" flag in either
     tcpdump or Tethereal is to allow the output of a live capture to
     be piped to a program or script and to have that script see the
     information for the packet as soon as it's printed, rather than
     having to wait until a standard I/O buffer fills up. */
  if (line_buffered)
    fflush(stdout);

  epan_dissect_free(edt);

  clear_fdata(&fdata);
}

char *
file_open_error_message(int err, gboolean for_writing, int file_type)
{
  char *errmsg;
  static char errmsg_errno[1024+1];

  switch (err) {

  case WTAP_ERR_NOT_REGULAR_FILE:
    errmsg = "The file \"%s\" is a \"special file\" or socket or other non-regular file.";
    break;

  case WTAP_ERR_FILE_UNKNOWN_FORMAT:
  case WTAP_ERR_UNSUPPORTED:
    /* Seen only when opening a capture file for reading. */
    errmsg = "The file \"%s\" is not a capture file in a format Tethereal understands.";
    break;

  case WTAP_ERR_CANT_WRITE_TO_PIPE:
    /* Seen only when opening a capture file for writing. */
    snprintf(errmsg_errno, sizeof(errmsg_errno),
	     "The file \"%%s\" is a pipe, and %s capture files cannot be "
	     "written to a pipe.", wtap_file_type_string(file_type));
    errmsg = errmsg_errno;
    break;

  case WTAP_ERR_UNSUPPORTED_FILE_TYPE:
    /* Seen only when opening a capture file for writing. */
    errmsg = "Tethereal does not support writing capture files in that format.";
    break;

  case WTAP_ERR_UNSUPPORTED_ENCAP:
  case WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED:
    if (for_writing)
      errmsg = "Tethereal cannot save this capture in that format.";
    else
      errmsg = "The file \"%s\" is a capture for a network type that Tethereal doesn't support.";
    break;

  case WTAP_ERR_BAD_RECORD:
    errmsg = "The file \"%s\" appears to be damaged or corrupt.";
    break;

  case WTAP_ERR_CANT_OPEN:
    if (for_writing)
      errmsg = "The file \"%s\" could not be created for some unknown reason.";
    else
      errmsg = "The file \"%s\" could not be opened for some unknown reason.";
    break;

  case WTAP_ERR_SHORT_READ:
    errmsg = "The file \"%s\" appears to have been cut short"
             " in the middle of a packet or other data.";
    break;

  case WTAP_ERR_SHORT_WRITE:
    errmsg = "A full header couldn't be written to the file \"%s\".";
    break;

  case ENOENT:
    if (for_writing)
      errmsg = "The path to the file \"%s\" does not exist.";
    else
      errmsg = "The file \"%s\" does not exist.";
    break;

  case EACCES:
    if (for_writing)
      errmsg = "You do not have permission to create or write to the file \"%s\".";
    else
      errmsg = "You do not have permission to read the file \"%s\".";
    break;

  case EISDIR:
    errmsg = "\"%s\" is a directory (folder), not a file.";
    break;

  default:
    snprintf(errmsg_errno, sizeof(errmsg_errno),
	     "The file \"%%s\" could not be %s: %s.",
	     for_writing ? "created" : "opened",
	     wtap_strerror(err));
    errmsg = errmsg_errno;
    break;
  }
  return errmsg;
}

int
open_cap_file(char *fname, gboolean is_tempfile, capture_file *cf)
{
  wtap       *wth;
  int         err;
  char        err_msg[2048+1];

  wth = wtap_open_offline(fname, &err, FALSE);
  if (wth == NULL)
    goto fail;

  /* The open succeeded.  Fill in the information for this file. */

  /* Initialize all data structures used for dissection. */
  init_dissection();

  cf->wth = wth;
  cf->filed = -1;	/* not used, but set it anyway */
  cf->f_len = 0;	/* not used, but set it anyway */

  /* Set the file name because we need it to set the follow stream filter.
     XXX - is that still true?  We need it for other reasons, though,
     in any case. */
  cf->filename = g_strdup(fname);

  /* Indicate whether it's a permanent or temporary file. */
  cf->is_tempfile = is_tempfile;

  /* If it's a temporary capture buffer file, mark it as not saved. */
  cf->user_saved = !is_tempfile;

  cf->cd_t      = wtap_file_type(cf->wth);
  cf->count     = 0;
  cf->drops_known = FALSE;
  cf->drops     = 0;
  cf->esec      = 0;
  cf->eusec     = 0;
  cf->snap      = wtap_snapshot_length(cf->wth);
  if (cf->snap == 0) {
    /* Snapshot length not known. */
    cf->has_snap = FALSE;
    cf->snap = WTAP_MAX_PACKET_SIZE;
  } else
    cf->has_snap = TRUE;
  cf->progbar_quantum = 0;
  cf->progbar_nextstep = 0;
  firstsec = 0, firstusec = 0;
  prevsec = 0, prevusec = 0;
 
  return (0);

fail:
  snprintf(err_msg, sizeof err_msg, file_open_error_message(err, FALSE, 0),
	   fname);
  fprintf(stderr, "tethereal: %s\n", err_msg);
  return (err);
}