Add an option to col_fill_in() to allow us to disable column expression processing...

[obnox/wireshark/wip.git] / tshark.c

/* tshark.c
 *
 * Text-mode variant of Wireshark, along the lines of tcpdump and snoop,
 * by Gilbert Ramirez <gram@alumni.rice.edu> and Guy Harris <guy@alum.mit.edu>.
 *
 * $Id$
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * 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_SYS_STAT_H
# include <sys/stat.h>
#endif

#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 <wsutil/privileges.h>

#include "globals.h"
#include <epan/timestamp.h>
#include <epan/packet.h>
#include "file.h"
#include "disabled_protos.h"
#include <epan/prefs.h>
#include <epan/column.h>
#include "print.h"
#include <epan/addr_resolv.h>
#include "util.h"
#include "clopts_common.h"
#include "cmdarg_err.h"
#include "version_info.h"
#include <epan/plugins.h>
#include "register.h"
#include <epan/epan_dissect.h>
#include <epan/tap.h>
#include <epan/stat_cmd_args.h>
#include <epan/timestamp.h>
#include <epan/ex-opt.h>

#ifdef HAVE_LIBPCAP
#include "capture_ui_utils.h"
#include <pcap.h>
#include "capture-pcap-util.h"
#ifdef _WIN32
#include "capture-wpcap.h"
#include "capture_errs.h"
#endif /* _WIN32 */
#include "capture_sync.h"
#endif /* HAVE_LIBPCAP */
#include "log.h"
#include <epan/funnel.h>


/*
 * This is the template for the decode as option; it is shared between the
 * various functions that output the usage for this parameter.
 */
static const gchar decode_as_arg_template[] = "<layer_type>==<selector>,<decode_as_protocol>";

static nstime_t first_ts;
static nstime_t prev_dis_ts;
static nstime_t prev_cap_ts;
static GString *comp_info_str, *runtime_info_str;

static gboolean print_packet_info;      /* TRUE if we're to print packet information */
/*
 * The way the packet decode is to be written.
 */
typedef enum {
        WRITE_TEXT,     /* summary or detail text */
        WRITE_XML,      /* PDML or PSML */
        WRITE_FIELDS    /* User defined list of fields */
        /* Add CSV and the like here */
} output_action_e;
static output_action_e output_action;
static gboolean do_dissection;  /* TRUE if we have to dissect each packet */
static gboolean verbose;
static gboolean print_hex;
static gboolean line_buffered;
static guint32 cum_bytes = 0;
static print_format_e print_format = PR_FMT_TEXT;
static print_stream_t *print_stream;

static output_fields_t* output_fields  = NULL;

/*
 * Standard secondary message for unexpected errors.
 */
static const char please_report[] =
    "Please report this to the Wireshark developers";

#ifdef HAVE_LIBPCAP
/*
 * TRUE if we're to print packet counts to keep track of captured packets.
 */
static gboolean print_packet_counts;


static capture_options global_capture_opts;

#ifdef SIGINFO
static gboolean infodelay;      /* if TRUE, don't print capture info in SIGINFO handler */
static gboolean infoprint;      /* if TRUE, print capture info after clearing infodelay */
#endif /* SIGINFO */

static int capture(void);
static void report_counts(void);
#ifdef _WIN32
static BOOL WINAPI capture_cleanup(DWORD);
#else /* _WIN32 */
static void capture_cleanup(int);
#ifdef SIGINFO
static void report_counts_siginfo(int);
#endif /* SIGINFO */
#endif /* _WIN32 */
#endif /* HAVE_LIBPCAP */

static int load_cap_file(capture_file *, char *, int, int, gint64);
static gboolean process_packet(capture_file *cf, gint64 offset,
    const struct wtap_pkthdr *whdr, union wtap_pseudo_header *pseudo_header,
    const guchar *pd, gboolean filtering_tap_listeners, guint tap_flags);
static void show_capture_file_io_error(const char *, int, gboolean);
static void show_print_file_io_error(int err);
static gboolean write_preamble(capture_file *cf);
static gboolean print_packet(capture_file *cf, epan_dissect_t *edt);
static gboolean write_finale(void);
static const char *cf_open_error_message(int err, gchar *err_info,
    gboolean for_writing, int file_type);

static void open_failure_message(const char *filename, int err,
    gboolean for_writing);
static void failure_message(const char *msg_format, va_list ap);
static void read_failure_message(const char *filename, int err);
static void write_failure_message(const char *filename, int err);

capture_file cfile;

/*
 * Mark a particular frame.
 * Copied from file.c
 */
void
cf_mark_frame(capture_file *cf, frame_data *frame)
{
  if (! frame->flags.marked) {
    frame->flags.marked = TRUE;
    if (cf->count > cf->marked_count)
      cf->marked_count++;
  }
}

/*
 * Unmark a particular frame.
 * Copied from file.c
 */
void
cf_unmark_frame(capture_file *cf, frame_data *frame)
{
  if (frame->flags.marked) {
    frame->flags.marked = FALSE;
    if (cf->marked_count > 0)
      cf->marked_count--;
  }
}


static void list_capture_types(void) {
    int i;

    fprintf(stderr, "editcap: The available capture file types for \"F\":\n");
    for (i = 0; i < WTAP_NUM_FILE_TYPES; i++) {
      if (wtap_dump_can_open(i))
        fprintf(stderr, "    %s - %s\n",
          wtap_file_type_short_string(i), wtap_file_type_string(i));
    }
}

static void
print_usage(gboolean print_ver)
{
  FILE *output;

  if (print_ver) {
    output = stdout;
    fprintf(output,
        "TShark " VERSION "%s\n"
        "Dump and analyze network traffic.\n"
        "See http://www.wireshark.org for more information.\n"
        "\n"
        "%s",
        wireshark_svnversion, get_copyright_info());
  } else {
    output = stderr;
  }
  fprintf(output, "\n");
  fprintf(output, "Usage: tshark [options] ...\n");
  fprintf(output, "\n");

#ifdef HAVE_LIBPCAP
  fprintf(output, "Capture interface:\n");
  fprintf(output, "  -i <interface>           name or idx of interface (def: first non-loopback)\n");
  fprintf(output, "  -f <capture filter>      packet filter in libpcap filter syntax\n");
  fprintf(output, "  -s <snaplen>             packet snapshot length (def: 65535)\n");
  fprintf(output, "  -p                       don't capture in promiscuous mode\n");
#ifdef _WIN32
  fprintf(output, "  -B <buffer size>         size of kernel buffer (def: 1MB)\n");
#endif
  fprintf(output, "  -y <link type>           link layer type (def: first appropriate)\n");
  fprintf(output, "  -D                       print list of interfaces and exit\n");
  fprintf(output, "  -L                       print list of link-layer types of iface and exit\n");
  fprintf(output, "\n");
  fprintf(output, "Capture stop conditions:\n");
  fprintf(output, "  -c <packet count>        stop after n packets (def: infinite)\n");
  fprintf(output, "  -a <autostop cond.> ...  duration:NUM - stop after NUM seconds\n");
  fprintf(output, "                           filesize:NUM - stop this file after NUM KB\n");
  fprintf(output, "                              files:NUM - stop after NUM files\n");
  /*fprintf(output, "\n");*/
  fprintf(output, "Capture output:\n");
  fprintf(output, "  -b <ringbuffer opt.> ... duration:NUM - switch to next file after NUM secs\n");
  fprintf(output, "                           filesize:NUM - switch to next file after NUM KB\n");
  fprintf(output, "                              files:NUM - ringbuffer: replace after NUM files\n");
#endif  /* HAVE_LIBPCAP */

  /*fprintf(output, "\n");*/
  fprintf(output, "Input file:\n");
  fprintf(output, "  -r <infile>              set the filename to read from (no pipes or stdin!)\n");

  fprintf(output, "\n");
  fprintf(output, "Processing:\n");
  fprintf(output, "  -R <read filter>         packet filter in Wireshark display filter syntax\n");
  fprintf(output, "  -n                       disable all name resolutions (def: all enabled)\n");
  fprintf(output, "  -N <name resolve flags>  enable specific name resolution(s): \"mntC\"\n");
  fprintf(output, "  -d %s ...\n", decode_as_arg_template);
  fprintf(output, "                           \"Decode As\", see the man page for details\n");
  fprintf(output, "                           Example: tcp.port==8888,http\n");

  /*fprintf(output, "\n");*/
  fprintf(output, "Output:\n");
  fprintf(output, "  -w <outfile|->           write packets to a pcap-format file named \"outfile\"\n");
  fprintf(output, "                           (or to the standard output for \"-\")\n");
  fprintf(output, "  -C <config profile>      start with specified configuration profile\n");
  fprintf(output, "  -F <output file type>    set the output file type, default is libpcap\n");
  fprintf(output, "                           an empty \"-F\" option will list the file types\n");
  fprintf(output, "  -V                       add output of packet tree        (Packet Details)\n");
  fprintf(output, "  -S                       display packets even when writing to a file\n");
  fprintf(output, "  -x                       add output of hex and ASCII dump (Packet Bytes)\n");
  fprintf(output, "  -T pdml|ps|psml|text|fields\n");
  fprintf(output, "                           format of text output (def: text)\n");
  fprintf(output, "  -e <field>               field to print if -Tfields selected (e.g. tcp.port);\n");
  fprintf(output, "                           this option can be repeated to print multiple fields\n");
  fprintf(output, "  -E<fieldsoption>=<value> set options for output when -Tfields selected:\n");
  fprintf(output, "     header=y|n            switch headers on and off\n");
  fprintf(output, "     separator=/t|/s|<char> select tab, space, printable character as separator\n");
  fprintf(output, "     quote=d|s|n           select double, single, no quotes for values\n");
  fprintf(output, "  -t ad|a|r|d|dd|e         output format of time stamps (def: r: rel. to first)\n");
  fprintf(output, "  -l                       flush standard output after each packet\n");
  fprintf(output, "  -q                       be more quiet on stdout (e.g. when using statistics)\n");
  fprintf(output, "  -X <key>:<value>         eXtension options, see the man page for details\n");
  fprintf(output, "  -z <statistics>          various statistics, see the man page for details\n");

  fprintf(output, "\n");
  fprintf(output, "Miscellaneous:\n");
  fprintf(output, "  -h                       display this help and exit\n");
  fprintf(output, "  -v                       display version info and exit\n");
  fprintf(output, "  -o <name>:<value> ...    override preference setting\n");
  fprintf(output, "  -K <keytab>              keytab file to use for kerberos decryption\n");
}

/*
 * For a dissector table, print on the stream described by output,
 * its short name (which is what's used in the "-d" option) and its
 * descriptive name.
 */
static void
display_dissector_table_names(const char *table_name, const char *ui_name,
                              gpointer output)
{
  fprintf((FILE *)output, "\t%s (%s)\n", table_name, ui_name);
}

/*
 * For a dissector handle, print on the stream described by output,
 * the filter name (which is what's used in the "-d" option) and the full
 * name for the protocol that corresponds to this handle.
 */
static void
display_dissector_names(const gchar *table _U_, gpointer handle, gpointer output)
{
  int                proto_id;
  const gchar*       proto_filter_name;
  const gchar*       proto_ui_name;

  proto_id = dissector_handle_get_protocol_index((dissector_handle_t)handle);

  if (proto_id != -1) {
    proto_filter_name = proto_get_protocol_filter_name(proto_id);
    proto_ui_name =  proto_get_protocol_name(proto_id);
    g_assert(proto_filter_name != NULL);
    g_assert(proto_ui_name != NULL);

    fprintf((FILE *)output, "\t%s (%s)\n",
            proto_filter_name,
            proto_ui_name);
  }
}

/*
 * The protocol_name_search structure is used by find_protocol_name_func()
 * to pass parameters and store results
 */
struct protocol_name_search{
  gchar              *searched_name;  /* Protocol filter name we are looking for */
  dissector_handle_t  matched_handle; /* Handle for a dissector whose protocol has the specified filter name */
  guint               nb_match;       /* How many dissectors matched searched_name */
};
typedef struct protocol_name_search *protocol_name_search_t;

/*
 * This function parses all dissectors associated with a table to find the
 * one whose protocol has the specified filter name.  It is called
 * as a reference function in a call to dissector_table_foreach_handle.
 * The name we are looking for, as well as the results, are stored in the
 * protocol_name_search struct pointed to by user_data.
 * If called using dissector_table_foreach_handle, we actually parse the
 * whole list of dissectors.
 */
static void
find_protocol_name_func(const gchar *table _U_, gpointer handle, gpointer user_data)

{
  int                         proto_id;
  const gchar                *protocol_filter_name;
  protocol_name_search_t      search_info;

  g_assert(handle);

  search_info = (protocol_name_search_t)user_data;

  proto_id = dissector_handle_get_protocol_index((dissector_handle_t)handle);
  if (proto_id != -1) {
    protocol_filter_name = proto_get_protocol_filter_name(proto_id);
    g_assert(protocol_filter_name != NULL);
    if (strcmp(protocol_filter_name, search_info->searched_name) == 0) {
      /* Found a match */
      if (search_info->nb_match == 0) {
        /* Record this handle only if this is the first match */
        search_info->matched_handle = (dissector_handle_t)handle; /* Record the handle for this matching dissector */
      }
      search_info->nb_match++;
    }
  }
}

/*
 * Print all layer type names supported.
 * We send the output to the stream described by the handle output.
 */

static void
fprint_all_layer_types(FILE *output)

{
  dissector_all_tables_foreach_table(display_dissector_table_names, (gpointer)output);
}

/*
 * Print all protocol names supported for a specific layer type.
 * table_name contains the layer type name in which the search is performed.
 * We send the output to the stream described by the handle output.
 */

static void
fprint_all_protocols_for_layer_types(FILE *output, gchar *table_name)

{
  dissector_table_foreach_handle(table_name,
                                 display_dissector_names,
                                 (gpointer)output);
}

/*
 * The function below parses the command-line parameters for the decode as
 * feature (a string pointer by cl_param).
 * It checks the format of the command-line, searches for a matching table
 * and dissector.  If a table/dissector match is not found, we display a
 * summary of the available tables/dissectors (on stderr) and return FALSE.
 * If everything is fine, we get the "Decode as" preference activated,
 * then we return TRUE.
 */
static gboolean
add_decode_as(const gchar *cl_param)
{
  gchar                        *table_name;
  guint32                       selector;
  gchar                        *decoded_param;
  gchar                        *remaining_param;
  gchar                        *selector_str;
  gchar                        *dissector_str;
  dissector_handle_t            dissector_matching;
  dissector_table_t             table_matching;
  ftenum_t                      dissector_table_selector_type;
  struct protocol_name_search   user_protocol_name;

  /* The following code will allocate and copy the command-line options in a string pointed by decoded_param */

  g_assert(cl_param);
  decoded_param = g_strdup(cl_param);
  g_assert(decoded_param);


  /* The lines below will parse this string (modifying it) to extract all
    necessary information.  Note that decoded_param is still needed since
    strings are not copied - we just save pointers. */

  /* This section extracts a layer type (table_name) from decoded_param */
  table_name = decoded_param; /* Layer type string starts from beginning */

  remaining_param = strchr(table_name, '=');
  if (remaining_param == NULL) {
    cmdarg_err("Parameter \"%s\" doesn't follow the template \"%s\"", cl_param, decode_as_arg_template);
    /* If the argument does not follow the template, carry on anyway to check
       if the table name is at least correct.  If remaining_param is NULL,
       we'll exit anyway further down */
  }
  else {
    *remaining_param = '\0'; /* Terminate the layer type string (table_name) where '=' was detected */
  }

  /* Remove leading and trailing spaces from the table name */
  while ( table_name[0] == ' ' )
    table_name++;
  while ( table_name[strlen(table_name) - 1] == ' ' )
    table_name[strlen(table_name) - 1] = '\0'; /* Note: if empty string, while loop will eventually exit */

/* The following part searches a table matching with the layer type specified */
  table_matching = NULL;

/* Look for the requested table */
  if ( !(*(table_name)) ) { /* Is the table name empty, if so, don't even search for anything, display a message */
    cmdarg_err("No layer type specified"); /* Note, we don't exit here, but table_matching will remain NULL, so we exit below */
  }
  else {
    table_matching = find_dissector_table(table_name);
    if (!table_matching) {
      cmdarg_err("Unknown layer type -- %s", table_name); /* Note, we don't exit here, but table_matching will remain NULL, so we exit below */
    }
  }

  if (!table_matching) {
    /* Display a list of supported layer types to help the user, if the
       specified layer type was not found */
    cmdarg_err("Valid layer types are:");
    fprint_all_layer_types(stderr);
  }
  if (remaining_param == NULL || !table_matching) {
    /* Exit if the layer type was not found, or if no '=' separator was found
       (see above) */
    g_free(decoded_param);
    return FALSE;
  }

  if (*(remaining_param + 1) != '=') { /* Check for "==" and not only '=' */
    cmdarg_err("WARNING: -d requires \"==\" instead of \"=\". Option will be treated as \"%s==%s\"", table_name, remaining_param + 1);
  }
  else {
    remaining_param++; /* Move to the second '=' */
    *remaining_param = '\0'; /* Remove the second '=' */
  }
  remaining_param++; /* Position after the layer type string */

  /* This section extracts a selector value (selector_str) from decoded_param */

  selector_str = remaining_param; /* Next part starts with the selector number */

  remaining_param = strchr(selector_str, ',');
  if (remaining_param == NULL) {
    cmdarg_err("Parameter \"%s\" doesn't follow the template \"%s\"", cl_param, decode_as_arg_template);
    /* If the argument does not follow the template, carry on anyway to check
       if the selector value is at least correct.  If remaining_param is NULL,
       we'll exit anyway further down */
  }
  else {
    *remaining_param = '\0'; /* Terminate the selector number string (selector_str) where ',' was detected */
  }

  dissector_table_selector_type = get_dissector_table_selector_type(table_name);

  switch (dissector_table_selector_type) {

  case FT_UINT8:
  case FT_UINT16:
  case FT_UINT24:
  case FT_UINT32:
    /* The selector for this table is an unsigned number.  Parse it as such.
       There's no need to remove leading and trailing spaces from the
       selector number string, because sscanf will do that for us. */
    if ( sscanf(selector_str, "%u", &selector) != 1 ) {
      cmdarg_err("Invalid selector number \"%s\"", selector_str);
      g_free(decoded_param);
      return FALSE;
    }
    break;

  case FT_STRING:
  case FT_STRINGZ:
  case FT_EBCDIC:
    /* The selector for this table is a string. */
    break;

  default:
    /* There are currently no dissector tables with any types other
       than the ones listed above. */
    g_assert_not_reached();
  }

  if (remaining_param == NULL) {
    /* Exit if no ',' separator was found (see above) */
    cmdarg_err("Valid protocols for layer type \"%s\" are:", table_name);
    fprint_all_protocols_for_layer_types(stderr, table_name);
    g_free(decoded_param);
    return FALSE;
  }

  remaining_param++; /* Position after the selector number string */

  /* This section extracts a protocol filter name (dissector_str) from decoded_param */

  dissector_str = remaining_param; /* All the rest of the string is the dissector (decode as protocol) name */

  /* Remove leading and trailing spaces from the dissector name */
  while ( dissector_str[0] == ' ' )
    dissector_str++;
  while ( dissector_str[strlen(dissector_str) - 1] == ' ' )
    dissector_str[strlen(dissector_str) - 1] = '\0'; /* Note: if empty string, while loop will eventually exit */

  dissector_matching = NULL;

  /* We now have a pointer to the handle for the requested table inside the variable table_matching */
  if ( ! (*dissector_str) ) { /* Is the dissector name empty, if so, don't even search for a matching dissector and display all dissectors found for the selected table */
    cmdarg_err("No protocol name specified"); /* Note, we don't exit here, but dissector_matching will remain NULL, so we exit below */
  }
  else {
    user_protocol_name.nb_match = 0;
    user_protocol_name.searched_name = dissector_str;
    user_protocol_name.matched_handle = NULL;

    dissector_table_foreach_handle(table_name, find_protocol_name_func, &user_protocol_name); /* Go and perform the search for this dissector in the this table's dissectors' names and shortnames */

    if (user_protocol_name.nb_match != 0) {
      dissector_matching = user_protocol_name.matched_handle;
      if (user_protocol_name.nb_match > 1) {
        cmdarg_err("WARNING: Protocol \"%s\" matched %u dissectors, first one will be used", dissector_str, user_protocol_name.nb_match);
      }
    }
    else {
      /* OK, check whether the problem is that there isn't any such
         protocol, or that there is but it's not specified as a protocol
         that's valid for that dissector table.
         Note, we don't exit here, but dissector_matching will remain NULL,
         so we exit below */
      if (proto_get_id_by_filter_name(dissector_str) == -1) {
        /* No such protocol */
        cmdarg_err("Unknown protocol -- \"%s\"", dissector_str);
      } else {
        cmdarg_err("Protocol \"%s\" isn't valid for layer type \"%s\"",
                dissector_str, table_name);
      }
    }
  }

  if (!dissector_matching) {
    cmdarg_err("Valid protocols for layer type \"%s\" are:", table_name);
    fprint_all_protocols_for_layer_types(stderr, table_name);
    g_free(decoded_param);
    return FALSE;
  }

/* This is the end of the code that parses the command-line options.
   All information is now stored in the variables:
   table_name
   selector
   dissector_matching
   The above variables that are strings are still pointing to areas within
   decoded_parm.  decoded_parm thus still needs to be kept allocated in
   until we stop needing these variables
   decoded_param will be deallocated at each exit point of this function */


  /* We now have a pointer to the handle for the requested dissector
     (requested protocol) inside the variable dissector_matching */
  switch (dissector_table_selector_type) {

  case FT_UINT8:
  case FT_UINT16:
  case FT_UINT24:
  case FT_UINT32:
    /* The selector for this table is an unsigned number. */
    dissector_change(table_name, selector, dissector_matching);
    break;

  case FT_STRING:
  case FT_STRINGZ:
  case FT_EBCDIC:
    /* The selector for this table is a string. */
    dissector_change_string(table_name, selector_str, dissector_matching);
    break;

  default:
    /* There are currently no dissector tables with any types other
       than the ones listed above. */
    g_assert_not_reached();
  }
  g_free(decoded_param); /* "Decode As" rule has been succesfully added */
  return TRUE;
}

static void
tshark_log_handler (const gchar *log_domain, GLogLevelFlags log_level,
    const gchar *message, gpointer user_data)
{
  /* ignore log message, if log_level isn't interesting based
     upon the console log preferences.
     If the preferences haven't been loaded loaded yet, display the
     message anyway.

     The default console_log_level preference value is such that only
       ERROR, CRITICAL and WARNING level messages are processed;
       MESSAGE, INFO and DEBUG level messages are ignored.

     XXX: Aug 07, 2009: Prior tshark g_log code was hardwired to process only
           ERROR and CRITICAL level messages so the current code is a behavioral
           change.  The current behavior is the same as in Wireshark.
  */
  if((log_level & G_LOG_LEVEL_MASK & prefs.console_log_level) == 0 &&
     prefs.console_log_level != 0) {
    return;
  }

  g_log_default_handler(log_domain, log_level, message, user_data);

}

static char *
output_file_description(const char *fname)
{
  char *save_file_string;

  /* Get a string that describes what we're writing to */
  if (strcmp(fname, "-") == 0) {
    /* We're writing to the standard output */
    save_file_string = g_strdup("standard output");
  } else {
    /* We're writing to a file with the name in save_file */
    save_file_string = g_strdup_printf("file \"%s\"", fname);
  }
  return save_file_string;
}

static void
print_current_user(void) {
  gchar *cur_user, *cur_group;
  if (started_with_special_privs()) {
    cur_user = get_cur_username();
    cur_group = get_cur_groupname();
    fprintf(stderr, "Running as user \"%s\" and group \"%s\".",
      cur_user, cur_group);
    g_free(cur_user);
    g_free(cur_group);
    if (running_with_special_privs()) {
      fprintf(stderr, " This could be dangerous.");
    }
    fprintf(stderr, "\n");
  }
}

static void
check_capture_privs(void) {
#ifdef _WIN32
  load_wpcap();
  /* Warn the user if npf.sys isn't loaded. */
  if (!npf_sys_is_running() && get_os_major_version() >= 6) {
    fprintf(stderr, "The NPF driver isn't running.  You may have trouble "
      "capturing or\nlisting interfaces.\n");
  }
#endif
}



int
main(int argc, char *argv[])
{
  char                *init_progfile_dir_error;
  int                  opt;
  extern char         *optarg;
  gboolean             arg_error = FALSE;

#ifdef _WIN32
  WSADATA               wsaData;
#endif  /* _WIN32 */

  char                *gpf_path, *pf_path;
  char                *gdp_path, *dp_path;
  int                  gpf_open_errno, gpf_read_errno;
  int                  pf_open_errno, pf_read_errno;
  int                  gdp_open_errno, gdp_read_errno;
  int                  dp_open_errno, dp_read_errno;
  int                  err;
#ifdef HAVE_LIBPCAP
  gboolean             list_link_layer_types = FALSE;
  gboolean             start_capture = FALSE;
  int                  status;
#else
  gboolean             capture_option_specified = FALSE;
#endif
  gboolean             quiet = FALSE;
  int                  out_file_type = WTAP_FILE_PCAP;
  gchar               *cf_name = NULL, *rfilter = NULL;
#ifdef HAVE_PCAP_OPEN_DEAD
  struct bpf_program   fcode;
#endif
  dfilter_t           *rfcode = NULL;
  e_prefs             *prefs;
  char                 badopt;
  GLogLevelFlags       log_flags;
  int                  optind_initial;

#define OPTSTRING_INIT "a:b:c:C:d:De:E:f:F:G:hi:K:lLnN:o:pqr:R:s:St:T:vVw:xX:y:z:"
#ifdef HAVE_LIBPCAP
#ifdef _WIN32
#define OPTSTRING_WIN32 "B:"
#else
#define OPTSTRING_WIN32 ""
#endif  /* _WIN32 */
#else
#define OPTSTRING_WIN32 ""
#endif  /* HAVE_LIBPCAP */

  static const char    optstring[] = OPTSTRING_INIT OPTSTRING_WIN32;

  /*
   * Get credential information for later use.
   */
  get_credential_info();

  /*
   * Attempt to get the pathname of the executable file.
   */
  init_progfile_dir_error = init_progfile_dir(argv[0], main);
  if (init_progfile_dir_error != NULL) {
    fprintf(stderr, "tshark: Can't get pathname of tshark program: %s.\n",
            init_progfile_dir_error);
  }

  /*
   * In order to have the -X opts assigned before the wslua machine starts
   * we need to call getopts before epan_init() gets called.
   */
  opterr = 0;
  optind_initial = optind;

  while ((opt = getopt(argc, argv, optstring)) != -1) {
          switch (opt) {
                  case 'C':        /* Configuration Profile */
                          if (profile_exists (optarg)) {
                                  set_profile_name (optarg);
                          } else {
                                  cmdarg_err("Configuration Profile \"%s\" does not exist", optarg);
                                  exit(1);
                          }
                          break;
                  case 'X':
                          ex_opt_add(optarg);
                          break;
                  default:
                          break;
          }
  }

  optind = optind_initial;
  opterr = 1;



/** Send All g_log messages to our own handler **/

  log_flags =
                    G_LOG_LEVEL_ERROR|
                    G_LOG_LEVEL_CRITICAL|
                    G_LOG_LEVEL_WARNING|
                    G_LOG_LEVEL_MESSAGE|
                    G_LOG_LEVEL_INFO|
                    G_LOG_LEVEL_DEBUG|
                    G_LOG_FLAG_FATAL|G_LOG_FLAG_RECURSION;

  g_log_set_handler(NULL,
                    log_flags,
                    tshark_log_handler, NULL /* user_data */);
  g_log_set_handler(LOG_DOMAIN_MAIN,
                    log_flags,
                    tshark_log_handler, NULL /* user_data */);

#ifdef HAVE_LIBPCAP
  g_log_set_handler(LOG_DOMAIN_CAPTURE,
                    log_flags,
                    tshark_log_handler, NULL /* user_data */);
  g_log_set_handler(LOG_DOMAIN_CAPTURE_CHILD,
                    log_flags,
                    tshark_log_handler, NULL /* user_data */);
#endif

  initialize_funnel_ops();

#ifdef HAVE_LIBPCAP
  capture_opts_init(&global_capture_opts, &cfile);
#endif

  timestamp_set_type(TS_RELATIVE);
  timestamp_set_precision(TS_PREC_AUTO);

  /* 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(register_all_protocols, register_all_protocol_handoffs, NULL, NULL,
            failure_message, open_failure_message, read_failure_message,
            write_failure_message);

  /* Register all tap listeners; we do this before we parse the arguments,
     as the "-z" argument can specify a registered tap. */

  /* we register the plugin taps before the other taps because
     stats_tree taps plugins will be registered as tap listeners
     by stats_tree_stat.c and need to registered before that */
#ifdef HAVE_PLUGINS
  register_all_plugin_tap_listeners();
#endif
  register_all_tap_listeners();

  /* 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.

     XXX - we do this here, for now, to support "-G" with no arguments.
     If none of our build or other processes uses "-G" with no arguments,
     we can just process it with the other arguments. */
  if (argc >= 2 && strcmp(argv[1], "-G") == 0) {
          proto_initialize_all_prefixes();

    if (argc == 2)
      proto_registrar_dump_fields(1);
    else {
      if (strcmp(argv[2], "fields") == 0)
        proto_registrar_dump_fields(1);
      else if (strcmp(argv[2], "fields2") == 0)
        proto_registrar_dump_fields(2);
      else if (strcmp(argv[2], "fields3") == 0)
        proto_registrar_dump_fields(3);
      else if (strcmp(argv[2], "protocols") == 0)
        proto_registrar_dump_protocols();
      else if (strcmp(argv[2], "values") == 0)
        proto_registrar_dump_values();
      else if (strcmp(argv[2], "decodes") == 0)
        dissector_dump_decodes();
      else if (strcmp(argv[2], "defaultprefs") == 0)
        write_prefs(NULL);
      else if (strcmp(argv[2], "currentprefs") == 0) {
        read_prefs(&gpf_open_errno, &gpf_read_errno, &gpf_path,
            &pf_open_errno, &pf_read_errno, &pf_path);
        write_prefs(NULL);
      } else {
        cmdarg_err("Invalid \"%s\" option for -G flag", 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_read_errno, &gpf_path,
                     &pf_open_errno, &pf_read_errno, &pf_path);
  if (gpf_path != NULL) {
    if (gpf_open_errno != 0) {
      cmdarg_err("Can't open global preferences file \"%s\": %s.",
              pf_path, strerror(gpf_open_errno));
    }
    if (gpf_read_errno != 0) {
      cmdarg_err("I/O error reading global preferences file \"%s\": %s.",
              pf_path, strerror(gpf_read_errno));
    }
  }
  if (pf_path != NULL) {
    if (pf_open_errno != 0) {
      cmdarg_err("Can't open your preferences file \"%s\": %s.", pf_path,
              strerror(pf_open_errno));
    }
    if (pf_read_errno != 0) {
      cmdarg_err("I/O error reading your preferences file \"%s\": %s.",
              pf_path, strerror(pf_read_errno));
    }
    g_free(pf_path);
    pf_path = NULL;
  }

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

  /* Read the disabled protocols file. */
  read_disabled_protos_list(&gdp_path, &gdp_open_errno, &gdp_read_errno,
                            &dp_path, &dp_open_errno, &dp_read_errno);
  if (gdp_path != NULL) {
    if (gdp_open_errno != 0) {
      cmdarg_err("Could not open global disabled protocols file\n\"%s\": %s.",
                 gdp_path, strerror(gdp_open_errno));
    }
    if (gdp_read_errno != 0) {
      cmdarg_err("I/O error reading global disabled protocols file\n\"%s\": %s.",
                 gdp_path, strerror(gdp_read_errno));
    }
    g_free(gdp_path);
  }
  if (dp_path != NULL) {
    if (dp_open_errno != 0) {
      cmdarg_err(
        "Could not open your disabled protocols file\n\"%s\": %s.", dp_path,
        strerror(dp_open_errno));
    }
    if (dp_read_errno != 0) {
      cmdarg_err(
        "I/O error reading your disabled protocols file\n\"%s\": %s.", dp_path,
        strerror(dp_read_errno));
    }
    g_free(dp_path);
  }

  check_capture_privs();

  init_cap_file(&cfile);

  /* Assemble the compile-time version information string */
  comp_info_str = g_string_new("Compiled ");
  get_compiled_version_info(comp_info_str, get_epan_compiled_version_info);

  /* Assemble the run-time version information string */
  runtime_info_str = g_string_new("Running ");
  get_runtime_version_info(runtime_info_str, NULL);

  /* Print format defaults to this. */
  print_format = PR_FMT_TEXT;

  output_fields = output_fields_new();

  /* Now get our args */
  while ((opt = getopt(argc, argv, optstring)) != -1) {
    switch (opt) {
      case 'a':        /* autostop criteria */
      case 'b':        /* Ringbuffer option */
      case 'c':        /* Capture x packets */
      case 'f':        /* capture filter */
      case 'i':        /* Use interface x */
      case 'p':        /* Don't capture in promiscuous mode */
      case 's':        /* Set the snapshot (capture) length */
      case 'w':        /* Write to capture file x */
      case 'y':        /* Set the pcap data link type */
#ifdef _WIN32
      case 'B':        /* Buffer size */
#endif /* _WIN32 */
#ifdef HAVE_LIBPCAP
        status = capture_opts_add_opt(&global_capture_opts, opt, optarg, &start_capture);
        if(status != 0) {
            exit(status);
        }
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 'C':
        /* Configuration profile settings were already processed just ignore them this time*/
        break;
      case 'd':        /* Decode as rule */
        if (!add_decode_as(optarg))
          exit(1);
        break;
#if defined(HAVE_HEIMDAL_KERBEROS) || defined(HAVE_MIT_KERBEROS)
      case 'K':        /* Kerberos keytab file */
        read_keytab_file(optarg);
        break;
#endif
      case 'D':        /* Print a list of capture devices and exit */
#ifdef HAVE_LIBPCAP
        status = capture_opts_list_interfaces(FALSE);
        exit(status);
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        break;
      case 'e':
        /* Field entry */
        output_fields_add(output_fields, optarg);
        break;
      case 'E':
        /* Field option */
        if(!output_fields_set_option(output_fields, optarg)) {
          cmdarg_err("\"%s\" is not a valid field output option=value pair.", optarg);
          output_fields_list_options(stderr);
          exit(1);
        }
        break;
      case 'F':
        out_file_type = wtap_short_string_to_file_type(optarg);
        if (out_file_type < 0) {
          cmdarg_err("\"%s\" isn't a valid capture file type", optarg);
          list_capture_types();
          exit(1);
        }
        break;
      case 'h':        /* Print help and exit */
        print_usage(TRUE);
        exit(0);
        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 (and
           is probably actually better for "-V", as it does fewer
           writes).

           See the comment in "process_packet()" 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 'L':        /* Print list of link-layer types and exit */
#ifdef HAVE_LIBPCAP
        list_link_layer_types = TRUE;
#else
        capture_option_specified = TRUE;
        arg_error = TRUE;
#endif
        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') {
          cmdarg_err("-N specifies unknown resolving option '%c';",
                     badopt);
          cmdarg_err_cont( "           Valid options are 'm', 'n', 't', and 'C'");
          exit(1);
        }
        break;
      case 'o':        /* Override preference from command line */
        switch (prefs_set_pref(optarg)) {

        case PREFS_SET_OK:
          break;

        case PREFS_SET_SYNTAX_ERR:
          cmdarg_err("Invalid -o flag \"%s\"", optarg);
          exit(1);
          break;

        case PREFS_SET_NO_SUCH_PREF:
        case PREFS_SET_OBSOLETE:
          cmdarg_err("-o flag \"%s\" specifies unknown preference", optarg);
          exit(1);
          break;
        }
        break;
      case 'q':        /* Quiet */
        quiet = TRUE;
        break;
      case 'r':        /* Read capture file x */
        cf_name = g_strdup(optarg);
        break;
      case 'R':        /* Read file filter */
        rfilter = optarg;
        break;
      case 'S':        /* show packets in real time */
        print_packet_info = TRUE;
        break;
      case 't':        /* Time stamp type */
        if (strcmp(optarg, "r") == 0)
          timestamp_set_type(TS_RELATIVE);
        else if (strcmp(optarg, "a") == 0)
          timestamp_set_type(TS_ABSOLUTE);
        else if (strcmp(optarg, "ad") == 0)
          timestamp_set_type(TS_ABSOLUTE_WITH_DATE);
        else if (strcmp(optarg, "d") == 0)
          timestamp_set_type(TS_DELTA);
        else if (strcmp(optarg, "dd") == 0)
          timestamp_set_type(TS_DELTA_DIS);
        else if (strcmp(optarg, "e") == 0)
          timestamp_set_type(TS_EPOCH);
        else {
          cmdarg_err("Invalid time stamp type \"%s\"",
            optarg);
          cmdarg_err_cont("It must be \"r\" for relative, \"a\" for absolute,");
          cmdarg_err_cont("\"ad\" for absolute with date, or \"d\" for delta.");
          exit(1);
        }
        break;
      case 'T':        /* printing Type */
        if (strcmp(optarg, "text") == 0) {
          output_action = WRITE_TEXT;
          print_format = PR_FMT_TEXT;
        } else if (strcmp(optarg, "ps") == 0) {
          output_action = WRITE_TEXT;
          print_format = PR_FMT_PS;
        } else if (strcmp(optarg, "pdml") == 0) {
          output_action = WRITE_XML;
          verbose = TRUE;
        } else if (strcmp(optarg, "psml") == 0) {
          output_action = WRITE_XML;
          verbose = FALSE;
        } else if(strcmp(optarg, "fields") == 0) {
          output_action = WRITE_FIELDS;
          verbose = TRUE; /* Need full tree info */
        } else {
          cmdarg_err("Invalid -T parameter.");
          cmdarg_err_cont("It must be \"ps\", \"text\", \"pdml\", \"psml\" or \"fields\".");
          exit(1);
        }
        break;
      case 'v':        /* Show version and exit */
        printf("TShark " VERSION "%s\n"
               "\n"
               "%s"
               "\n"
               "%s"
               "\n"
               "%s",
               wireshark_svnversion, get_copyright_info(), comp_info_str->str,
               runtime_info_str->str);
        exit(0);
        break;
      case 'V':        /* Verbose */
        verbose = TRUE;
        break;
      case 'x':        /* Print packet data in hex (and ASCII) */
          print_hex = TRUE;
          break;
      case 'X':
          break;
      case 'z':
        /* We won't call the init function for the stat this soon
           as it would disallow MATE's fields (which are registered
           by the preferences set callback) from being used as
           part of a tap filter.  Instead, we just add the argument
           to a list of stat arguments. */
        if (!process_stat_cmd_arg(optarg)) {
          cmdarg_err("invalid -z argument.");
          cmdarg_err_cont("  -z argument must be one of :");
          list_stat_cmd_args();
          exit(1);
        }
        break;
      default:
      case '?':        /* Bad flag - print usage message */
        switch(optopt) {
        case 'F':
          list_capture_types();
          break;
        default:
          print_usage(TRUE);
        }
        exit(1);
        break;
    }
  }

  /* If we specified output fields, but not the output field type... */
  if(WRITE_FIELDS != output_action && 0 != output_fields_num_fields(output_fields)) {
        cmdarg_err("Output fields were specified with \"-e\", "
            "but \"-Tfields\" was not specified.");
        exit(1);
  } else if(WRITE_FIELDS == output_action && 0 == output_fields_num_fields(output_fields)) {
        cmdarg_err("\"-Tfields\" was specified, but no fields were "
                    "specified with \"-e\".");

        exit(1);
  }

  /* 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) {
        cmdarg_err("Read filters were specified both with \"-R\" "
            "and with additional command-line arguments");
        exit(1);
      }
      rfilter = get_args_as_string(argc, argv, optind);
    } else {
#ifdef HAVE_LIBPCAP
      if (global_capture_opts.has_cfilter) {
        cmdarg_err("Capture filters were specified both with \"-f\""
            " and with additional command-line arguments");
        exit(1);
      }
      global_capture_opts.has_cfilter = TRUE;
      global_capture_opts.cfilter = get_args_as_string(argc, argv, optind);
#else
      capture_option_specified = TRUE;
#endif
    }
  }

#ifdef HAVE_LIBPCAP
  if (!global_capture_opts.saving_to_file) {
    /* We're not saving the capture to a file; if "-q" wasn't specified,
       we should print packet information */
    if (!quiet)
      print_packet_info = TRUE;
  } else {
    /* We're saving to a file; if we're writing to the standard output.
       and we'll also be writing dissected packets to the standard
       output, reject the request.  At best, we could redirect that
       to the standard error; we *can't* write both to the standard
       output and have either of them be useful. */
    if (strcmp(global_capture_opts.save_file, "-") == 0 && print_packet_info) {
      cmdarg_err("You can't write both raw packet data and dissected packets"
          " to the standard output.");
      exit(1);
    }
  }
#else
  /* We're not saving the capture to a file; if "-q" wasn't specified,
     we should print packet information */
  if (!quiet)
    print_packet_info = TRUE;
#endif

#ifndef HAVE_LIBPCAP
  if (capture_option_specified)
    cmdarg_err("This version of TShark was not built with support for capturing packets.");
#endif
  if (arg_error) {
    print_usage(FALSE);
    exit(1);
  }

  /* We don't support capture filters when reading from a capture file
     (the BPF compiler doesn't support all link-layer types that we
     support in capture files we read). */
#ifdef HAVE_LIBPCAP
  if (cf_name != NULL) {
    if (global_capture_opts.has_cfilter) {
      cmdarg_err("Only read filters, not capture filters, "
          "can be specified when reading a capture file.");
      exit(1);
    }
  }
#endif

  if (print_hex) {
    if (output_action != WRITE_TEXT) {
      cmdarg_err("Raw packet hex data can only be printed as text or PostScript");
      exit(1);
    }
  }

#ifdef HAVE_LIBPCAP
  if (list_link_layer_types) {
    /* We're supposed to list the link-layer types for an interface;
       did the user also specify a capture file to be read? */
    if (cf_name) {
      /* Yes - that's bogus. */
      cmdarg_err("You can't specify -L and a capture file to be read.");
      exit(1);
    }
    /* No - did they specify a ring buffer option? */
    if (global_capture_opts.multi_files_on) {
      cmdarg_err("Ring buffer requested, but a capture isn't being done.");
      exit(1);
    }
  } else {
    if (cf_name) {
      /*
       * "-r" was specified, so we're reading a capture file.
       * Capture options don't apply here.
       */
      if (global_capture_opts.multi_files_on) {
        cmdarg_err("Multiple capture files requested, but "
                   "a capture isn't being done.");
        exit(1);
      }
      if (global_capture_opts.has_file_duration) {
        cmdarg_err("Switching capture files after a time interval was specified, but "
                   "a capture isn't being done.");
        exit(1);
      }
      if (global_capture_opts.has_ring_num_files) {
        cmdarg_err("A ring buffer of capture files was specified, but "
          "a capture isn't being done.");
        exit(1);
      }
      if (global_capture_opts.has_autostop_files) {
        cmdarg_err("A maximum number of capture files was specified, but "
          "a capture isn't being done.");
        exit(1);
      }

      /* Note: TShark now allows the restriction of a _read_ file by packet count
       * and byte count as well as a write file. Other autostop options remain valid
       * only for a write file.
       */
      if (global_capture_opts.has_autostop_duration) {
        cmdarg_err("A maximum capture time was specified, but "
          "a capture isn't being done.");
        exit(1);
      }
    } else {
      /*
       * "-r" wasn't specified, so we're doing a live capture.
       */
      if (global_capture_opts.saving_to_file) {
        /* They specified a "-w" flag, so we'll be saving to a capture file. */

        /* When capturing, we only support writing libpcap format. */
        if (out_file_type != WTAP_FILE_PCAP) {
          cmdarg_err("Live captures can only be saved in libpcap format.");
          exit(1);
        }
        if (global_capture_opts.multi_files_on) {
          /* Multiple-file mode doesn't work under certain conditions:
             a) it doesn't work if you're writing to the standard output;
             b) it doesn't work if you're writing to a pipe;
          */
          if (strcmp(global_capture_opts.save_file, "-") == 0) {
            cmdarg_err("Multiple capture files requested, but "
              "the capture is being written to the standard output.");
            exit(1);
          }
          if (global_capture_opts.output_to_pipe) {
            cmdarg_err("Multiple capture files requested, but "
              "the capture file is a pipe.");
            exit(1);
          }
          if (!global_capture_opts.has_autostop_filesize &&
              !global_capture_opts.has_file_duration) {
            cmdarg_err("Multiple capture files requested, but "
              "no maximum capture file size or duration was specified.");
            exit(1);
          }
        }
      } else {
        /* They didn't specify a "-w" flag, so we won't be saving to a
           capture file.  Check for options that only make sense if
           we're saving to a file. */
        if (global_capture_opts.has_autostop_filesize) {
          cmdarg_err("Maximum capture file size specified, but "
           "capture isn't being saved to a file.");
          exit(1);
        }
        if (global_capture_opts.multi_files_on) {
          cmdarg_err("Multiple capture files requested, but "
            "the capture isn't being saved to a file.");
          exit(1);
        }
      }
    }
  }
#endif

#ifdef _WIN32
  /* Start windows sockets */
  WSAStartup( MAKEWORD( 1, 1 ), &wsaData );
#endif /* _WIN32 */

  /* 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();

  /* At this point MATE will have registered its field array so we can
     have a tap filter with one of MATE's late-registered fields as part
     of the filter.  We can now process all the "-z" arguments. */
  start_requested_stats();

  /* disabled protocols as per configuration file */
  if (gdp_path == NULL && dp_path == NULL) {
    set_disabled_protos_list();
  }

  /* Build the column format array */
  build_column_format_array(&cfile.cinfo, prefs->num_cols, TRUE);

#ifdef HAVE_LIBPCAP
  capture_opts_trim_snaplen(&global_capture_opts, MIN_PACKET_SIZE);
  capture_opts_trim_ring_num_files(&global_capture_opts);
#endif

  if (rfilter != NULL) {
    if (!dfilter_compile(rfilter, &rfcode)) {
      cmdarg_err("%s", dfilter_error_msg);
      epan_cleanup();
#ifdef HAVE_PCAP_OPEN_DEAD
      {
        pcap_t *pc;

        pc = pcap_open_dead(DLT_EN10MB, MIN_PACKET_SIZE);
        if (pc != NULL) {
          if (pcap_compile(pc, &fcode, rfilter, 0, 0) != -1) {
            cmdarg_err_cont(
              "  Note: That display filter code looks like a valid capture filter;");
            cmdarg_err_cont(
              "        maybe you mixed them up?");
          }
          pcap_close(pc);
        }
      }
#endif
      exit(2);
    }
  }
  cfile.rfcode = rfcode;

  if (print_packet_info) {
    /* If we're printing as text or PostScript, we have
       to create a print stream. */
    if (output_action == WRITE_TEXT) {
      switch (print_format) {

      case PR_FMT_TEXT:
        print_stream = print_stream_text_stdio_new(stdout);
        break;

      case PR_FMT_PS:
        print_stream = print_stream_ps_stdio_new(stdout);
        break;

      default:
        g_assert_not_reached();
      }
    }
  }

  /* We have to dissect each packet if:

        we're printing information about each packet;

        we're using a read filter on the packets;

        we're using any taps. */
  do_dissection = print_packet_info || rfcode || have_tap_listeners();

  if (cf_name) {
    /*
     * We're reading a capture file.
     */

    /*
     * Immediately relinquish any special privileges we have; we must not
     * be allowed to read any capture files the user running TShark
     * can't open.
     */
    relinquish_special_privs_perm();
    print_current_user();

    if (cf_open(&cfile, cf_name, FALSE, &err) != CF_OK) {
      epan_cleanup();
      exit(2);
    }

    /* Set timestamp precision; there should arguably be a command-line
       option to let the user set this. */
    switch(wtap_file_tsprecision(cfile.wth)) {
    case(WTAP_FILE_TSPREC_SEC):
      timestamp_set_precision(TS_PREC_AUTO_SEC);
      break;
    case(WTAP_FILE_TSPREC_DSEC):
      timestamp_set_precision(TS_PREC_AUTO_DSEC);
      break;
    case(WTAP_FILE_TSPREC_CSEC):
      timestamp_set_precision(TS_PREC_AUTO_CSEC);
      break;
    case(WTAP_FILE_TSPREC_MSEC):
      timestamp_set_precision(TS_PREC_AUTO_MSEC);
      break;
    case(WTAP_FILE_TSPREC_USEC):
      timestamp_set_precision(TS_PREC_AUTO_USEC);
      break;
    case(WTAP_FILE_TSPREC_NSEC):
      timestamp_set_precision(TS_PREC_AUTO_NSEC);
      break;
    default:
      g_assert_not_reached();
    }

    /* Process the packets in the file */
#ifdef HAVE_LIBPCAP
    err = load_cap_file(&cfile, global_capture_opts.save_file, out_file_type,
        global_capture_opts.has_autostop_packets ? global_capture_opts.autostop_packets : 0,
        global_capture_opts.has_autostop_filesize ? global_capture_opts.autostop_filesize : 0);
#else
    err = load_cap_file(&cfile, NULL, out_file_type, 0, 0);
#endif
    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
       (or get a list of link-layer types for a live capture device);
       do we have support for live captures? */
#ifdef HAVE_LIBPCAP

#ifdef _WIN32
    if (!has_wpcap) {
      char *detailed_err;

      cmdarg_err("WinPcap couldn't be found.");
      detailed_err = cant_load_winpcap_err("TShark");
      cmdarg_err_cont("%s", detailed_err);
      g_free(detailed_err);
      exit(2);
    }
#endif

    /* trim the interface name and exit if that failed */
    if (!capture_opts_trim_iface(&global_capture_opts,
        (prefs->capture_device) ? get_if_name(prefs->capture_device) : NULL)) {
        exit(2);
    }

    /* if requested, list the link layer types and exit */
    if (list_link_layer_types) {
        status = capture_opts_list_link_layer_types(&global_capture_opts, FALSE);
        exit(status);
    }

    if (print_packet_info) {
      if (!write_preamble(NULL)) {
        err = errno;
        show_print_file_io_error(err);
        return err;
      }
    } else if (!quiet) {
      /*
       * We're not printing information for each packet, and the user
       * didn't ask us not to print a count of packets as they arrive,
       * so print that count so the user knows that packets are arriving.
       *
       * XXX - what if the user wants to do a live capture, doesn't want
       * to save it to a file, doesn't want information printed for each
       * packet, does want some "-z" statistic, and wants packet counts
       * so they know whether they're seeing any packets?
       */
      print_packet_counts = TRUE;
    }

    /* For now, assume libpcap gives microsecond precision. */
    timestamp_set_precision(TS_PREC_AUTO_USEC);

    capture();

    if (print_packet_info) {
      if (!write_finale()) {
        err = errno;
        show_print_file_io_error(err);
      }
    }
#else
    /* No - complain. */
    cmdarg_err("This version of TShark was not built with support for capturing packets.");
    exit(2);
#endif
  }

  draw_tap_listeners(TRUE);
  funnel_dump_all_text_windows();
  epan_cleanup();

  output_fields_free(output_fields);
  output_fields = NULL;

  return 0;
}

/*#define USE_BROKEN_G_MAIN_LOOP*/

#ifdef USE_BROKEN_G_MAIN_LOOP
  GMainLoop *loop;
#else
  gboolean loop_running = FALSE;
#endif
  guint32 packet_count = 0;


/* XXX - move to the right position / file */
/* read from a pipe (callback) */
typedef gboolean (*pipe_input_cb_t) (gint source, gpointer user_data);

typedef struct pipe_input_tag {
    gint                source;
    gpointer            user_data;
    int                 *child_process;
    pipe_input_cb_t     input_cb;
    guint               pipe_input_id;
#ifdef _WIN32
    GStaticMutex                callback_running;
#endif
} pipe_input_t;

static pipe_input_t pipe_input;

#ifdef _WIN32
/* The timer has expired, see if there's stuff to read from the pipe,
   if so, do the callback */
static gint
pipe_timer_cb(gpointer data)
{
  HANDLE handle;
  DWORD avail = 0;
  gboolean result, result1;
  DWORD childstatus;
  pipe_input_t *pipe_input = data;
  gint iterations = 0;


  g_static_mutex_lock (&pipe_input->callback_running);

  /* try to read data from the pipe only 5 times, to avoid blocking */
  while(iterations < 5) {
          /*g_log(NULL, G_LOG_LEVEL_DEBUG, "pipe_timer_cb: new iteration");*/

          /* Oddly enough although Named pipes don't work on win9x,
                 PeekNamedPipe does !!! */
          handle = (HANDLE) _get_osfhandle (pipe_input->source);
          result = PeekNamedPipe(handle, NULL, 0, NULL, &avail, NULL);

          /* Get the child process exit status */
          result1 = GetExitCodeProcess((HANDLE)*(pipe_input->child_process),
                                                                   &childstatus);

          /* If the Peek returned an error, or there are bytes to be read
                 or the childwatcher thread has terminated then call the normal
                 callback */
          if (!result || avail > 0 || childstatus != STILL_ACTIVE) {

                /*g_log(NULL, G_LOG_LEVEL_DEBUG, "pipe_timer_cb: data avail");*/

                /* And call the real handler */
                if (!pipe_input->input_cb(pipe_input->source, pipe_input->user_data)) {
                        g_log(NULL, G_LOG_LEVEL_DEBUG, "pipe_timer_cb: input pipe closed, iterations: %u", iterations);
                        /* pipe closed, return false so that the timer is stopped */
                        g_static_mutex_unlock (&pipe_input->callback_running);
                        return FALSE;
                }
          }
          else {
                /*g_log(NULL, G_LOG_LEVEL_DEBUG, "pipe_timer_cb: no data avail");*/
                /* No data, stop now */
                break;
          }

          iterations++;
  }

        /*g_log(NULL, G_LOG_LEVEL_DEBUG, "pipe_timer_cb: finished with iterations: %u, new timer", iterations);*/

        g_static_mutex_unlock (&pipe_input->callback_running);

        /* we didn't stopped the timer, so let it run */
        return TRUE;
}
#endif


void
pipe_input_set_handler(gint source, gpointer user_data, int *child_process, pipe_input_cb_t input_cb)
{

    pipe_input.source                   = source;
    pipe_input.child_process            = child_process;
    pipe_input.user_data                = user_data;
    pipe_input.input_cb                 = input_cb;

#ifdef _WIN32
    g_static_mutex_init(&pipe_input.callback_running);
    /* Tricky to use pipes in win9x, as no concept of wait.  NT can
       do this but that doesn't cover all win32 platforms.  GTK can do
       this but doesn't seem to work over processes.  Attempt to do
       something similar here, start a timer and check for data on every
       timeout. */
        /*g_log(NULL, G_LOG_LEVEL_DEBUG, "pipe_input_set_handler: new");*/
    pipe_input.pipe_input_id = g_timeout_add(200, pipe_timer_cb, &pipe_input);
#endif
}


#ifdef HAVE_LIBPCAP
static int
capture(void)
{
  gboolean ret;
#ifdef USE_TSHARK_SELECT
  fd_set readfds;
#endif
#ifndef _WIN32
  struct sigaction action, oldaction;
#endif

  /*
   * XXX - dropping privileges is still required, until code cleanup is done
   *
   * remove all dependencies to pcap specific code and using only dumpcap is almost done.
   * when it's done, we don't need special privileges to run tshark at all,
   * therefore we don't need to drop these privileges
   * The only thing we might want to keep is a warning if tshark is run as root,
   * as it's no longer necessary and potentially dangerous.
   *
   * THE FOLLOWING IS THE FORMER COMMENT WHICH IS NO LONGER REALLY VALID:
   * We've opened the capture device, so we shouldn't need any special
   * privileges any more; relinquish those privileges.
   *
   * XXX - if we have saved set-user-ID support, we should give up those
   * privileges immediately, and then reclaim them long enough to get
   * a list of network interfaces and to open one, and then give them
   * up again, so that stuff we do while processing the argument list,
   * reading the user's preferences, loading and starting plugins
   * (especially *user* plugins), etc. is done with the user's privileges,
   * not special privileges.
   */
  relinquish_special_privs_perm();
  print_current_user();

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

#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. */
  action.sa_handler = capture_cleanup;
  action.sa_flags = 0;
  sigemptyset(&action.sa_mask);
  sigaction(SIGTERM, &action, NULL);
  sigaction(SIGINT, &action, NULL);
  sigaction(SIGHUP, NULL, &oldaction);
  if (oldaction.sa_handler == SIG_DFL)
    sigaction(SIGHUP, &action, NULL);

#ifdef SIGINFO
  /* Catch SIGINFO and, if we get it and we're capturing to a file in
     quiet mode, report the number of packets we've captured. */
  action.sa_handler = report_counts_siginfo;
  action.sa_flags = 0;
  sigemptyset(&action.sa_mask);
  sigaction(SIGINFO, &action, NULL);
#endif /* SIGINFO */
#endif /* _WIN32 */

  global_capture_opts.state = CAPTURE_PREPARING;

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

  ret = sync_pipe_start(&global_capture_opts);

  if (!ret)
    return FALSE;

    /* the actual capture loop
     *
     * XXX - glib doesn't seem to provide any event based loop handling.
     *
     * XXX - for whatever reason,
     * calling g_main_loop_new() ends up in 100% cpu load.
     *
     * But that doesn't matter: in UNIX we can use select() to find an input
     * source with something to do.
     *
     * But that doesn't matter because we're in a CLI (that doesn't need to
     * update a GUI or something at the same time) so it's OK if we block
     * trying to read from the pipe.
     *
     * So all the stuff in USE_TSHARK_SELECT could be removed unless I'm
     * wrong (but I leave it there in case I am...).
     */

#ifdef USE_TSHARK_SELECT
  FD_ZERO(&readfds);
  FD_SET(pipe_input.source, &readfds);
#endif

  loop_running = TRUE;

  while (loop_running)
  {
#ifdef USE_TSHARK_SELECT
    ret = select(pipe_input.source+1, &readfds, NULL, NULL, NULL);

    if (ret == -1)
    {
      perror("select()");
      return TRUE;
    } else if (ret == 1) {
#endif
      /* Call the real handler */
      if (!pipe_input.input_cb(pipe_input.source, pipe_input.user_data)) {
        g_log(NULL, G_LOG_LEVEL_DEBUG, "input pipe closed");
        return FALSE;
      }
#ifdef USE_TSHARK_SELECT
    }
#endif
  }

  return TRUE;
}


/* XXX - move the call to main_window_update() out of capture_sync.c */
/* dummy for capture_sync.c to make linker happy */
void main_window_update(void)
{
}

/* capture child detected an error */
void
capture_input_error_message(capture_options *capture_opts _U_, char *error_msg, char *secondary_error_msg)
{
        cmdarg_err("%s", error_msg);
        cmdarg_err_cont("%s", secondary_error_msg);
}


/* capture child detected an capture filter related error */
void
capture_input_cfilter_error_message(capture_options *capture_opts, char *error_message)
{
    dfilter_t   *rfcode = NULL;


    if (dfilter_compile(capture_opts->cfilter, &rfcode) && rfcode != NULL) {
      cmdarg_err(
        "Invalid capture filter: \"%s\"!\n"
        "\n"
        "That string looks like a valid display filter; however, it isn't a valid\n"
        "capture filter (%s).\n"
        "\n"
        "Note that display filters and capture filters don't have the same syntax,\n"
        "so you can't use most display filter expressions as capture filters.\n"
        "\n"
        "See the User's Guide for a description of the capture filter syntax.",
        capture_opts->cfilter, error_message);
      dfilter_free(rfcode);
    } else {
      cmdarg_err(
        "Invalid capture filter: \"%s\"!\n"
        "\n"
        "That string isn't a valid capture filter (%s).\n"
        "See the User's Guide for a description of the capture filter syntax.",
        capture_opts->cfilter, error_message);
    }
}


/* capture child tells us we have a new (or the first) capture file */
gboolean
capture_input_new_file(capture_options *capture_opts, gchar *new_file)
{
  gboolean is_tempfile;
  int  err;


  if(capture_opts->state == CAPTURE_PREPARING) {
    g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "Capture started!");
  }
  g_log(LOG_DOMAIN_CAPTURE, G_LOG_LEVEL_MESSAGE, "File: \"%s\"", new_file);

  g_assert(capture_opts->state == CAPTURE_PREPARING || capture_opts->state == CAPTURE_RUNNING);

  /* free the old filename */
  if (capture_opts->save_file != NULL) {

    /* we start a new capture file, close the old one (if we had one before) */
    if( ((capture_file *) capture_opts->cf)->state != FILE_CLOSED) {
      if ( ((capture_file *) capture_opts->cf)->wth != NULL) {
        wtap_close(((capture_file *) capture_opts->cf)->wth);
      }
      ((capture_file *) capture_opts->cf)->state = FILE_CLOSED;
    }

    g_free(capture_opts->save_file);
    is_tempfile = FALSE;
  } else {
    /* we didn't had a save_file before, must be a tempfile */
    is_tempfile = TRUE;
  }

  /* save the new filename */
  capture_opts->save_file = g_strdup(new_file);

  /* if we are in real-time mode, open the new file now */
  if(do_dissection) {
    /* Attempt to open the capture file and set up to read from it. */
    switch(cf_open(capture_opts->cf, capture_opts->save_file, is_tempfile, &err)) {
    case CF_OK:
      break;
    case CF_ERROR:
      /* Don't unlink (delete) the save file - leave it around,
         for debugging purposes. */
      g_free(capture_opts->save_file);
      capture_opts->save_file = NULL;
      return FALSE;
    }
  }

  capture_opts->state = CAPTURE_RUNNING;

  return TRUE;
}


/* capture child tells us we have new packets to read */
void
capture_input_new_packets(capture_options *capture_opts, int to_read)
{
  gboolean     ret;
  int          err;
  gchar        *err_info;
  gint64       data_offset;
  capture_file *cf = capture_opts->cf;
  gboolean filtering_tap_listeners;
  guint tap_flags;

#ifdef SIGINFO
  /*
   * Prevent a SIGINFO handler from writing to stdout while we're
   * doing so; instead, have it just set a flag telling us to print
   * that information when we're done.
   */
  infodelay = TRUE;
#endif /* SIGINFO */

  /* Do we have any tap listeners with filters? */
  filtering_tap_listeners = have_filtering_tap_listeners();

  /* Get the union of the flags for all tap listeners. */
  tap_flags = union_of_tap_listener_flags();

  if(do_dissection) {
    while (to_read-- && cf->wth) {
      ret = wtap_read(cf->wth, &err, &err_info, &data_offset);
      if(ret == FALSE) {
        /* read from file failed, tell the capture child to stop */
        sync_pipe_stop(capture_opts);
        wtap_close(cf->wth);
        cf->wth = NULL;
      } else {
        ret = process_packet(cf, data_offset, wtap_phdr(cf->wth),
                             wtap_pseudoheader(cf->wth), wtap_buf_ptr(cf->wth),
                             filtering_tap_listeners, tap_flags);
      }
      if (ret != FALSE) {
        /* packet sucessfully read and gone through the "Read Filter" */
        packet_count++;
      }
    }
  } else {
    /*
     * Dumpcap's doing all the work; we're not doing any dissection.
     * Count all the packets it wrote.
     */
    packet_count += to_read;
  }

  if (print_packet_counts) {
      /* We're printing packet counts. */
      if (packet_count != 0) {
        fprintf(stderr, "\r%u ", packet_count);
        /* stderr could be line buffered */
        fflush(stderr);
      }
  }

#ifdef SIGINFO
  /*
   * Allow SIGINFO handlers to write.
   */
  infodelay = FALSE;

  /*
   * If a SIGINFO handler asked us to write out capture counts, do so.
   */
  if (infoprint)
    report_counts();
#endif /* SIGINFO */
}

static void
report_counts(void)
{
  if (!print_packet_counts) {
    /* Report the count only if we aren't printing a packet count
       as packets arrive. */
    fprintf(stderr, "%u packet%s captured\n", packet_count,
            plurality(packet_count, "", "s"));
  }
#ifdef SIGINFO
  infoprint = FALSE; /* we just reported it */
#endif /* SIGINFO */
}

#ifdef SIGINFO
static void
report_counts_siginfo(int signum _U_)
{
  int sav_errno = errno;
  /* If we've been told to delay printing, just set a flag asking
     that we print counts (if we're supposed to), otherwise print
     the count of packets captured (if we're supposed to). */
  if (infodelay)
    infoprint = TRUE;
  else
    report_counts();
  errno = sav_errno;
}
#endif /* SIGINFO */


/* capture child detected any packet drops? */
void
capture_input_drops(capture_options *capture_opts _U_, guint32 dropped)
{
  if (print_packet_counts) {
    /* We're printing packet counts to stderr.
       Send a newline so that we move to the line after the packet count. */
    fprintf(stderr, "\n");
  }

  if (dropped != 0) {
    /* We're printing packet counts to stderr.
       Send a newline so that we move to the line after the packet count. */
    fprintf(stderr, "%u packet%s dropped\n", dropped, plurality(dropped, "", "s"));
  }
}


/* capture child closed its side of the pipe, do the required cleanup */
void
capture_input_closed(capture_options *capture_opts)
{
  report_counts();

  if(capture_opts->cf != NULL && ((capture_file *) capture_opts->cf)->wth != NULL) {
    wtap_close(((capture_file *) capture_opts->cf)->wth);
  }
#ifdef USE_BROKEN_G_MAIN_LOOP
  /*g_main_loop_quit(loop);*/
  g_main_quit(loop);
#else
  loop_running = FALSE;
#endif
}




#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 TShark, if you run this in
     a Cygwin console window in at least some versions of Cygwin,
     causes TShark 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 TShark is not built with Cygwin - for all I know,
     building it with Cygwin may make the problem go away). */

  /* tell the capture child to stop */
  sync_pipe_stop(&global_capture_opts);

  /* don't stop our own loop already here, otherwise status messages and
   * cleanup wouldn't be done properly. The child will indicate the stop of
   * everything by calling capture_input_closed() later */

  return TRUE;
}
#else
static void
capture_cleanup(int signum _U_)
{
  /* tell the capture child to stop */
  sync_pipe_stop(&global_capture_opts);
}
#endif /* _WIN32 */
#endif /* HAVE_LIBPCAP */

static int
load_cap_file(capture_file *cf, char *save_file, int out_file_type,
    int max_packet_count, gint64 max_byte_count)
{
  gint         linktype;
  int          snapshot_length;
  wtap_dumper *pdh;
  int          err;
  gchar        *err_info;
  gint64       data_offset;
  char         *save_file_string = NULL;
  gboolean     filtering_tap_listeners;
  guint        tap_flags;

  linktype = wtap_file_encap(cf->wth);
  if (save_file != NULL) {
    /* Get a string that describes what we're writing to */
    save_file_string = output_file_description(save_file);

    /* 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(save_file, out_file_type, linktype, snapshot_length,
                         FALSE /* compressed */, &err);

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

      case WTAP_ERR_UNSUPPORTED_FILE_TYPE:
        cmdarg_err("Capture files can't be written in that format.");
        break;

      case WTAP_ERR_UNSUPPORTED_ENCAP:
      case WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED:
        cmdarg_err("The capture file being read can't be written in "
          "that format.");
        break;

      case WTAP_ERR_CANT_OPEN:
        cmdarg_err("The %s couldn't be created for some "
          "unknown reason.", save_file_string);
        break;

      case WTAP_ERR_SHORT_WRITE:
        cmdarg_err("A full header couldn't be written to the %s.",
                   save_file_string);
        break;

      default:
        cmdarg_err("The %s could not be created: %s.", save_file_string,
                   wtap_strerror(err));
        break;
      }
      goto out;
    }
  } else {
    if (print_packet_info) {
      if (!write_preamble(cf)) {
        err = errno;
        show_print_file_io_error(err);
        goto out;
      }
    }
    pdh = NULL;
  }

  /* Do we have any tap listeners with filters? */
  filtering_tap_listeners = have_filtering_tap_listeners();

  /* Get the union of the flags for all tap listeners. */
  tap_flags = union_of_tap_listener_flags();

  while (wtap_read(cf->wth, &err, &err_info, &data_offset)) {
    if (process_packet(cf, data_offset, wtap_phdr(cf->wth),
                       wtap_pseudoheader(cf->wth), wtap_buf_ptr(cf->wth),
                       filtering_tap_listeners, tap_flags)) {
      /* Either there's no read filtering or this packet passed the
         filter, so, if we're writing to a capture file, write
         this packet out. */
      if (pdh != NULL) {
        if (!wtap_dump(pdh, wtap_phdr(cf->wth),
                       wtap_pseudoheader(cf->wth), wtap_buf_ptr(cf->wth),
                       &err)) {
          /* Error writing to a capture file */
          show_capture_file_io_error(save_file, err, FALSE);
          wtap_dump_close(pdh, &err);
          exit(2);
        }
      }
      /* Stop reading if we have the maximum number of packets;
       * When the -c option has not been used, max_packet_count
       * starts at 0, which practically means, never stop reading.
       * (unless we roll over max_packet_count ?)
       */
      if( (--max_packet_count == 0) || (max_byte_count != 0 && data_offset >= max_byte_count)) {
        err = 0; /* This is not an error */
        break;
      }
    }
  }
  if (err != 0) {
    /* Print a message noting that the read failed somewhere along the line. */
    switch (err) {

    case WTAP_ERR_UNSUPPORTED_ENCAP:
      cmdarg_err("\"%s\" has a packet with a network type that TShark doesn't support.\n(%s)",
                 cf->filename, err_info);
      g_free(err_info);
      break;

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

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

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

    default:
      cmdarg_err("An error occurred while reading \"%s\": %s.",
                 cf->filename, wtap_strerror(err));
      break;
    }
    if (save_file != NULL) {
      /* Now close the capture file. */
      if (!wtap_dump_close(pdh, &err))
        show_capture_file_io_error(save_file, err, TRUE);
    }
  } else {
    if (save_file != NULL) {
      /* Now close the capture file. */
      if (!wtap_dump_close(pdh, &err))
        show_capture_file_io_error(save_file, err, TRUE);
    } else {
      if (print_packet_info) {
        if (!write_finale()) {
          err = errno;
          show_print_file_io_error(err);
        }
      }
    }
  }

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

  g_free(save_file_string);

  return err;
}

static void
fill_in_fdata(frame_data *fdata, capture_file *cf,
              const struct wtap_pkthdr *phdr, gint64 offset)
{
  fdata->next = NULL;
  fdata->prev = NULL;
  fdata->pfd = NULL;
  fdata->num = cf->count;
  fdata->pkt_len = phdr->len;
  cum_bytes += phdr->len;
  fdata->cum_bytes  = cum_bytes;
  fdata->cap_len = phdr->caplen;
  fdata->file_off = offset;
  /* To save some memory, we coarcese it into a gint8 */
  g_assert(phdr->pkt_encap <= G_MAXINT8);
  fdata->lnk_t = (gint8) phdr->pkt_encap;
  fdata->abs_ts.secs = phdr->ts.secs;
  fdata->abs_ts.nsecs = phdr->ts.nsecs;
  fdata->flags.passed_dfilter = 0;
  fdata->flags.encoding = CHAR_ASCII;
  fdata->flags.visited = 0;
  fdata->flags.marked = 0;
  fdata->flags.ref_time = 0;
  fdata->color_filter = NULL;

  /* 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 (nstime_is_unset(&first_ts)) {
    first_ts = fdata->abs_ts;
  }

  /* If we don't have the time stamp of the previous captured packet,
     it's because this is the first packet.  Save the time
     stamp of this packet as the time stamp of the previous captured
     packet. */
  if (nstime_is_unset(&prev_cap_ts)) {
    prev_cap_ts = fdata->abs_ts;
  }

  /* Get the time elapsed between the first packet and this packet. */
  nstime_delta(&fdata->rel_ts, &fdata->abs_ts, &first_ts);

  /* 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->elapsed_time.secs < fdata->rel_ts.secs
        || ((gint32)cf->elapsed_time.secs == fdata->rel_ts.secs && (gint32)cf->elapsed_time.nsecs < fdata->rel_ts.nsecs)) {
    cf->elapsed_time = fdata->rel_ts;
  }

  /* If we don't have the time stamp of the previous displayed packet,
     it's because this is the first packet that's being displayed.  Save the time
     stamp of this packet as the time stamp of the previous displayed
     packet. */
  if (nstime_is_unset(&prev_dis_ts))
    prev_dis_ts = fdata->abs_ts;

  /* Get the time elapsed between the previous displayed packet and
     this packet. */
  nstime_delta(&fdata->del_dis_ts, &fdata->abs_ts, &prev_dis_ts);

  /* Get the time elapsed between the previous captured packet and
     this packet. */
  nstime_delta(&fdata->del_cap_ts, &fdata->abs_ts, &prev_cap_ts);
  prev_cap_ts = fdata->abs_ts;
}

/* 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 gboolean
process_packet(capture_file *cf, gint64 offset, const struct wtap_pkthdr *whdr,
               union wtap_pseudo_header *pseudo_header, const guchar *pd,
               gboolean filtering_tap_listeners, guint tap_flags)
{
  frame_data fdata;
  gboolean create_proto_tree;
  column_info *cinfo;
  epan_dissect_t edt;
  gboolean passed;

  /* Count this packet. */
  cf->count++;

  /* If we're going to print packet information, or we're going to
     run a read filter, or we're going to process taps, set up to
     do a dissection and do so. */
  if (do_dissection) {
    fill_in_fdata(&fdata, cf, whdr, offset);

    if (print_packet_info) {
      /* Grab any resolved addresses */

      if (g_resolv_flags) {
        host_name_lookup_process(NULL);
      }
    }

    passed = TRUE;
    if (cf->rfcode || verbose || filtering_tap_listeners ||
        (tap_flags & TL_REQUIRES_PROTO_TREE) || have_custom_cols(&cf->cinfo))
      create_proto_tree = TRUE;
    else
      create_proto_tree = FALSE;
    /* The protocol tree will be "visible", i.e., printed, only if we're
       printing packet details, which is true if we're printing stuff
       ("print_packet_info" is true) and we're in verbose mode ("verbose"
       is true). */
    epan_dissect_init(&edt, create_proto_tree, print_packet_info && verbose);

    /* If we're running a read filter, prime the epan_dissect_t with that
       filter. */
    if (cf->rfcode)
      epan_dissect_prime_dfilter(&edt, cf->rfcode);

    col_custom_prime_edt(&edt, &cf->cinfo);

    tap_queue_init(&edt);

    /* We only need the columns if either

         1) some tap needs the columns

       or

         2) we're printing packet info but we're *not* verbose; in verbose
            mode, we print the protocol tree, not the protocol summary. */
    if ((tap_flags & TL_REQUIRES_COLUMNS) || (print_packet_info && !verbose))
      cinfo = &cf->cinfo;
    else
      cinfo = NULL;
    epan_dissect_run(&edt, pseudo_header, pd, &fdata, cinfo);

    tap_push_tapped_queue(&edt);

    /* Run the read filter if we have one. */
    if (cf->rfcode)
      passed = dfilter_apply_edt(cf->rfcode, &edt);
    else
      passed = TRUE;
  } else {
    /* We're not running a display filter and we're not printing any
       packet information, so we don't need to do a dissection, and all
       packets are processed. */
    passed = TRUE;
  }

  if (passed) {
    /* Keep the time of the current packet if the packet passed
       the read filter so that the delta time since last displayed
       packet can be calculated */
    prev_dis_ts = fdata.abs_ts;

    /* Process this packet. */
    if (print_packet_info) {
      /* We're printing packet information; print the information for
         this packet. */
      if (do_dissection)
        print_packet(cf, &edt);
      else
        print_packet(cf, NULL);

      /* 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 TShark 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);

      if (ferror(stdout)) {
        show_print_file_io_error(errno);
        exit(2);
      }
    }
  }

  if (do_dissection) {
    epan_dissect_cleanup(&edt);
    clear_fdata(&fdata);
  }
  return passed;
}

static void
show_capture_file_io_error(const char *fname, int err, gboolean is_close)
{
  char *save_file_string;

  save_file_string = output_file_description(fname);

  switch (err) {

  case ENOSPC:
    cmdarg_err("Not all the packets could be written to the %s because there is "
               "no space left on the file system.",
               save_file_string);
    break;

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

  case WTAP_ERR_CANT_CLOSE:
    cmdarg_err("The %s couldn't be closed for some unknown reason.",
               save_file_string);
    break;

  case WTAP_ERR_SHORT_WRITE:
    cmdarg_err("Not all the packets could be written to the %s.",
               save_file_string);
    break;

  default:
    if (is_close) {
      cmdarg_err("The %s could not be closed: %s.", save_file_string,
                 wtap_strerror(err));
    } else {
      cmdarg_err("An error occurred while writing to the %s: %s.",
                 save_file_string, wtap_strerror(err));
    }
    break;
  }
  g_free(save_file_string);
}

static gboolean
write_preamble(capture_file *cf)
{
  switch (output_action) {

  case WRITE_TEXT:
    return print_preamble(print_stream, cf ? cf->filename : NULL);

  case WRITE_XML:
    if (verbose)
      write_pdml_preamble(stdout);
    else
      write_psml_preamble(stdout);
    return !ferror(stdout);

  case WRITE_FIELDS:
    write_fields_preamble(output_fields, stdout);
    return !ferror(stdout);

  default:
    g_assert_not_reached();
    return FALSE;
  }
}

static char *
get_line_buf(size_t len)
{
  static char *line_bufp = NULL;
  static size_t line_buf_len = 256;
  size_t new_line_buf_len;

  for (new_line_buf_len = line_buf_len; len > new_line_buf_len;
       new_line_buf_len *= 2)
    ;
  if (line_bufp == NULL) {
    line_buf_len = new_line_buf_len;
    line_bufp = g_malloc(line_buf_len + 1);
  } else {
    if (new_line_buf_len > line_buf_len) {
      line_buf_len = new_line_buf_len;
      line_bufp = g_realloc(line_bufp, line_buf_len + 1);
    }
  }
  return line_bufp;
}

static gboolean
print_columns(capture_file *cf)
{
  char *line_bufp;
  int i;
  size_t buf_offset;
  size_t column_len;

  line_bufp = get_line_buf(256);
  buf_offset = 0;
  *line_bufp = '\0';
  for (i = 0; i < cf->cinfo.num_cols; i++) {
    switch (cf->cinfo.col_fmt[i]) {
    case COL_NUMBER:
#ifdef HAVE_LIBPCAP
      /*
       * 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 Wireshark.)
       */
      if (global_capture_opts.iface != NULL)
        continue;
#endif
      column_len = strlen(cf->cinfo.col_data[i]);
      if (column_len < 3)
        column_len = 3;
      line_bufp = get_line_buf(buf_offset + column_len);
      sprintf(line_bufp + buf_offset, "%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 */
      column_len = strlen(cf->cinfo.col_data[i]);
      if (column_len < 10)
        column_len = 10;
      line_bufp = get_line_buf(buf_offset + column_len);
      sprintf(line_bufp + buf_offset, "%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:
      column_len = strlen(cf->cinfo.col_data[i]);
      if (column_len < 12)
        column_len = 12;
      line_bufp = get_line_buf(buf_offset + column_len);
      sprintf(line_bufp + buf_offset, "%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:
      column_len = strlen(cf->cinfo.col_data[i]);
      if (column_len < 12)
        column_len = 12;
      line_bufp = get_line_buf(buf_offset + column_len);
      sprintf(line_bufp + buf_offset, "%-12s", cf->cinfo.col_data[i]);
      break;

    default:
      column_len = strlen(cf->cinfo.col_data[i]);
      line_bufp = get_line_buf(buf_offset + column_len);
      strcat(line_bufp + buf_offset, cf->cinfo.col_data[i]);
      break;
    }
    buf_offset += column_len;
    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.
       *
       * We add enough space to the buffer for " <- " or " -> ",
       * even if we're only adding " ".
       */
      line_bufp = get_line_buf(buf_offset + 4);
      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:
          strcat(line_bufp + buf_offset, " -> ");
          buf_offset += 4;
          break;

        default:
          strcat(line_bufp + buf_offset, " ");
          buf_offset += 1;
          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:
          strcat(line_bufp + buf_offset, " -> ");
          buf_offset += 4;
          break;

        default:
          strcat(line_bufp + buf_offset, " ");
          buf_offset += 1;
          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:
          strcat(line_bufp + buf_offset, " -> ");
          buf_offset += 4;
          break;

        default:
          strcat(line_bufp + buf_offset, " ");
          buf_offset += 1;
          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:
          strcat(line_bufp + buf_offset, " <- ");
          buf_offset += 4;
          break;

        default:
          strcat(line_bufp + buf_offset, " ");
          buf_offset += 1;
          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:
          strcat(line_bufp + buf_offset, " <- ");
          buf_offset += 4;
          break;

        default:
          strcat(line_bufp + buf_offset, " ");
          buf_offset += 1;
          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:
          strcat(line_bufp + buf_offset, " <- ");
          buf_offset += 4;
          break;

        default:
          strcat(line_bufp + buf_offset, " ");
          buf_offset += 1;
          break;
        }
        break;

      default:
        strcat(line_bufp + buf_offset, " ");
        buf_offset += 1;
        break;
      }
    }
  }
  return print_line(print_stream, 0, line_bufp);
}

static gboolean
print_packet(capture_file *cf, epan_dissect_t *edt)
{
  print_args_t  print_args;

  if (verbose) {
    /* Print the information in the protocol tree. */
    switch (output_action) {

    case WRITE_TEXT:
      print_args.to_file = TRUE;
      print_args.format = print_format;
      print_args.print_summary = !verbose;
      print_args.print_hex = verbose && print_hex;
      print_args.print_formfeed = FALSE;
      print_args.print_dissections = verbose ? print_dissections_expanded : print_dissections_none;

      /* init the packet range */
      packet_range_init(&print_args.range);

      if (!proto_tree_print(&print_args, edt, print_stream))
        return FALSE;
      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. */
        if (!print_line(print_stream, 0, ""))
          return FALSE;
      }
      break;

    case WRITE_XML:
      proto_tree_write_pdml(edt, stdout);
      printf("\n");
      return !ferror(stdout);
    case WRITE_FIELDS:
      proto_tree_write_fields(output_fields, edt, stdout);
      printf("\n");
      return !ferror(stdout);
    }
  } else {
    /* Just fill in the columns. */
    epan_dissect_fill_in_columns(edt, FALSE, TRUE);

    /* Now print them. */
    switch (output_action) {

    case WRITE_TEXT:
        if (!print_columns(cf))
          return FALSE;
        break;

    case WRITE_XML:
        proto_tree_write_psml(edt, stdout);
        return !ferror(stdout);
    case WRITE_FIELDS: /*No non-verbose "fields" format */
        g_assert_not_reached();
        break;
    }
  }
  if (print_hex) {
    if (!print_hex_data(print_stream, edt))
      return FALSE;
    if (!print_line(print_stream, 0, ""))
      return FALSE;
  }
  return TRUE;
}

static gboolean
write_finale(void)
{
  switch (output_action) {

  case WRITE_TEXT:
    return print_finale(print_stream);

  case WRITE_XML:
    if (verbose)
      write_pdml_finale(stdout);
    else
      write_psml_finale(stdout);
    return !ferror(stdout);

  case WRITE_FIELDS:
    write_fields_finale(output_fields, stdout);
    return !ferror(stdout);

  default:
    g_assert_not_reached();
    return FALSE;
  }
}

static void
show_print_file_io_error(int err)
{
  switch (err) {

  case ENOSPC:
    cmdarg_err("Not all the packets could be printed because there is "
"no space left on the file system.");
    break;

#ifdef EDQUOT
  case EDQUOT:
    cmdarg_err("Not all the packets could be printed because you are "
"too close to, or over your disk quota.");
  break;
#endif

  default:
    cmdarg_err("An error occurred while printing packets: %s.",
      strerror(err));
    break;
  }
}

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

  if (err < 0) {
    /* Wiretap error. */
    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:
      /* Seen only when opening a capture file for reading. */
      errmsg = "The file \"%s\" isn't a capture file in a format TShark understands.";
      break;

    case WTAP_ERR_UNSUPPORTED:
      /* Seen only when opening a capture file for reading. */
      g_snprintf(errmsg_errno, sizeof(errmsg_errno),
               "The file \"%%s\" isn't a capture file in a format TShark understands.\n"
               "(%s)", err_info);
      g_free(err_info);
      errmsg = errmsg_errno;
      break;

    case WTAP_ERR_CANT_WRITE_TO_PIPE:
      /* Seen only when opening a capture file for writing. */
      g_snprintf(errmsg_errno, sizeof(errmsg_errno),
                 "The file \"%%s\" is a pipe, and %s capture files can't 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 = "TShark doesn't support writing capture files in that format.";
      break;

    case WTAP_ERR_UNSUPPORTED_ENCAP:
      if (for_writing)
        errmsg = "TShark can't save this capture in that format.";
      else {
        g_snprintf(errmsg_errno, sizeof(errmsg_errno),
                 "The file \"%%s\" is a capture for a network type that TShark doesn't support.\n"
                 "(%s)", err_info);
        g_free(err_info);
        errmsg = errmsg_errno;
      }
      break;

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

    case WTAP_ERR_BAD_RECORD:
      /* Seen only when opening a capture file for reading. */
      g_snprintf(errmsg_errno, sizeof(errmsg_errno),
               "The file \"%%s\" appears to be damaged or corrupt.\n"
               "(%s)", err_info);
      g_free(err_info);
      errmsg = errmsg_errno;
      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;

    default:
      g_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;
    }
  } else
    errmsg = file_open_error_message(err, for_writing);
  return errmsg;
}

/*
 * Open/create errors are reported with an console message in TShark.
 */
static void
open_failure_message(const char *filename, int err, gboolean for_writing)
{
  fprintf(stderr, "tshark: ");
  fprintf(stderr, file_open_error_message(err, for_writing), filename);
  fprintf(stderr, "\n");
}

cf_status_t
cf_open(capture_file *cf, const char *fname, gboolean is_tempfile, int *err)
{
  wtap       *wth;
  gchar       *err_info;
  char        err_msg[2048+1];

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

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

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

  cf->wth = wth;
  cf->f_datalen = 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->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;
  nstime_set_zero(&cf->elapsed_time);
  nstime_set_unset(&first_ts);
  nstime_set_unset(&prev_dis_ts);
  nstime_set_unset(&prev_cap_ts);

  cf->state = FILE_READ_IN_PROGRESS;

  return CF_OK;

fail:
  g_snprintf(err_msg, sizeof err_msg,
             cf_open_error_message(*err, err_info, FALSE, cf->cd_t), fname);
  cmdarg_err("%s", err_msg);
  return CF_ERROR;
}


/*
 * General errors are reported with an console message in TShark.
 */
static void
failure_message(const char *msg_format, va_list ap)
{
  fprintf(stderr, "tshark: ");
  vfprintf(stderr, msg_format, ap);
  fprintf(stderr, "\n");
}

/*
 * Read errors are reported with an console message in TShark.
 */
static void
read_failure_message(const char *filename, int err)
{
  cmdarg_err("An error occurred while reading from the file \"%s\": %s.",
          filename, strerror(err));
}

/*
 * Write errors are reported with an console message in TShark.
 */
static void
write_failure_message(const char *filename, int err)
{
  cmdarg_err("An error occurred while writing to the file \"%s\": %s.",
          filename, strerror(err));
}

/*
 * Report an error in command-line arguments.
 */
void
cmdarg_err(const char *fmt, ...)
{
  va_list ap;

  va_start(ap, fmt);
  failure_message(fmt, ap);
  va_end(ap);
}

/*
 * Report additional information for an error in command-line arguments.
 */
void
cmdarg_err_cont(const char *fmt, ...)
{
  va_list ap;

  va_start(ap, fmt);
  vfprintf(stderr, fmt, ap);
  fprintf(stderr, "\n");
  va_end(ap);
}