sort saved preference settings by appearance in dialog

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

/* file.c
 * File I/O routines
 *
 * $Id: file.c,v 1.384 2004/05/27 21:48:10 ulfl Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * 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.
 */

/* With MSVC and a libethereal.dll this file needs to import some variables 
   in a special way. Therefore _NEED_VAR_IMPORT_ is defined. */
#define _NEED_VAR_IMPORT_

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

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

#include <time.h>

#ifdef HAVE_IO_H
#include <io.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif

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

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

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

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

#include "color.h"
#include "column.h"
#include <epan/packet.h>
#include "range.h"
#include "print.h"
#include "file.h"
#include "menu.h"
#include "util.h"
#include "alert_box.h"
#include "simple_dialog.h"
#include "progress_dlg.h"
#include "ui_util.h"
#include "statusbar.h"
#include "prefs.h"
#include <epan/dfilter/dfilter.h>
#include <epan/conversation.h>
#include "globals.h"
#include <epan/epan_dissect.h>
#include "tap.h"
#include "tap_dfilter_dlg.h"
#include "packet-data.h"

#ifdef HAVE_LIBPCAP
gboolean auto_scroll_live;
#endif

static guint32 firstsec, firstusec;
static guint32 prevsec, prevusec;
static guint32 cum_bytes = 0;

static void read_packet(capture_file *cf, long offset);

static void rescan_packets(capture_file *cf, const char *action, const char *action_item,
        gboolean refilter, gboolean redissect);

static gboolean match_protocol_tree(capture_file *cf, frame_data *fdata,
        void *criterion);
static void match_subtree_text(proto_node *node, gpointer data);
static gboolean match_summary_line(capture_file *cf, frame_data *fdata,
        void *criterion);
static gboolean match_ascii_and_unicode(capture_file *cf, frame_data *fdata,
        void *criterion);
static gboolean match_ascii(capture_file *cf, frame_data *fdata,
        void *criterion);
static gboolean match_unicode(capture_file *cf, frame_data *fdata,
        void *criterion);
static gboolean match_binary(capture_file *cf, frame_data *fdata,
        void *criterion);
static gboolean match_dfilter(capture_file *cf, frame_data *fdata,
        void *criterion);
static gboolean find_packet(capture_file *cf,
        gboolean (*match_function)(capture_file *, frame_data *, void *),
        void *criterion);

static void cf_open_failure_alert_box(const char *filename, int err,
                                      gchar *err_info, gboolean for_writing,
                                      int file_type);
static char *file_rename_error_message(int err);
static void cf_write_failure_alert_box(const char *filename, int err);
static void cf_close_failure_alert_box(const char *filename, int err);
static   gboolean copy_binary_file(char *from_filename, char *to_filename);

/* Update the progress bar this many times when reading a file. */
#define N_PROGBAR_UPDATES       100

/* Number of "frame_data" structures per memory chunk.
   XXX - is this the right number? */
#define FRAME_DATA_CHUNK_SIZE   1024


int
cf_open(char *fname, gboolean is_tempfile, capture_file *cf)
{
  wtap       *wth;
  int         err;
  gchar       *err_info;
  int         fd;
  struct stat cf_stat;

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

  /* Find the size of the file. */
  fd = wtap_fd(wth);
  if (fstat(fd, &cf_stat) < 0) {
    err = errno;
    wtap_close(wth);
    goto fail;
  }

  /* The open succeeded.  Close whatever capture file we had open,
     and fill in the information for this file. */
  cf_close(cf);

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

  /* We're about to start reading the file. */
  cf->state = FILE_READ_IN_PROGRESS;

  cf->wth = wth;
  cf->filed = fd;
  cf->f_len = cf_stat.st_size;

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

  cf->plist_chunk = g_mem_chunk_new("frame_data_chunk",
        sizeof(frame_data),
        FRAME_DATA_CHUNK_SIZE * sizeof(frame_data),
        G_ALLOC_AND_FREE);
  g_assert(cf->plist_chunk);

  return (0);

fail:
  cf_open_failure_alert_box(fname, err, err_info, FALSE, 0);
  return (err);
}

/* Reset everything to a pristine state */
void
cf_close(capture_file *cf)
{
  /* Die if we're in the middle of reading a file. */
  g_assert(cf->state != FILE_READ_IN_PROGRESS);

  /* Destroy all windows, which refer to the
     capture file we're closing. */
  destroy_cfile_wins();

  if (cf->wth) {
    wtap_close(cf->wth);
    cf->wth = NULL;
  }
  /* We have no file open... */
  if (cf->filename != NULL) {
    /* If it's a temporary file, remove it. */
    if (cf->is_tempfile)
      unlink(cf->filename);
    g_free(cf->filename);
    cf->filename = NULL;
  }
  /* ...which means we have nothing to save. */
  cf->user_saved = FALSE;

  if (cf->plist_chunk != NULL) {
    g_mem_chunk_destroy(cf->plist_chunk);
    cf->plist_chunk = NULL;
  }
  if (cf->rfcode != NULL) {
    dfilter_free(cf->rfcode);
    cf->rfcode = NULL;
  }
  cf->plist = NULL;
  cf->plist_end = NULL;
  unselect_packet(cf);  /* nothing to select */
  cf->first_displayed = NULL;
  cf->last_displayed = NULL;

  /* No frame selected, no field in that frame selected. */
  cf->current_frame = NULL;
  cf->finfo_selected = NULL;

  /* Clear the packet list. */
  packet_list_freeze();
  packet_list_clear();
  packet_list_thaw();

  cf->f_len = 0;
  cf->count = 0;
  cf->esec  = 0;
  cf->eusec = 0;

  /* Clear any file-related status bar messages.
     XXX - should be "clear *ALL* file-related status bar messages;
     will there ever be more than one on the stack? */
  statusbar_pop_file_msg();

  /* Restore the standard title bar message. */
  set_main_window_name("The Ethereal Network Analyzer");

  /* Disable all menu items that make sense only if you have a capture. */
  set_menus_for_capture_file(FALSE);
  set_menus_for_unsaved_capture_file(FALSE);
  set_menus_for_captured_packets(FALSE);
  set_menus_for_selected_packet(cf);
  set_menus_for_capture_in_progress(FALSE);
  set_menus_for_selected_tree_row(cf);

  reset_tap_listeners();

  /* We have no file open. */
  cf->state = FILE_CLOSED;
}

/* Set the file name in the status line, in the name for the main window,
   and in the name for the main window's icon. */
static void
set_display_filename(capture_file *cf)
{
  gchar  *name_ptr;
  size_t  msg_len;
  static const gchar done_fmt_nodrops[] = " File: %s %s %02u:%02u:%02u";
  static const gchar done_fmt_drops[] = " File: %s %s %02u:%02u:%02u Drops: %u";
  gchar  *done_msg;
  gchar  *win_name_fmt = "%s - Ethereal";
  gchar  *win_name;
  gchar  *size_str;

  name_ptr = cf_get_display_name(cf);
        
  if (!cf->is_tempfile) {
    /* Add this filename to the list of recent files in the "Recent Files" submenu */
    add_menu_recent_capture_file(cf->filename);
  }

  if (cf->f_len/1024/1024 > 10) {
    size_str = g_strdup_printf("%ld MB", cf->f_len/1024/1024);
  } else if (cf->f_len/1024 > 10) {
    size_str = g_strdup_printf("%ld KB", cf->f_len/1024);
  } else {
    size_str = g_strdup_printf("%ld bytes", cf->f_len);
  }

  if (cf->drops_known) {
    done_msg = g_strdup_printf(done_fmt_drops, name_ptr, size_str, 
        cf->esec/3600, cf->esec%3600/60, cf->esec%60, cf->drops);
  } else {
    done_msg = g_strdup_printf(done_fmt_nodrops, name_ptr, size_str,
        cf->esec/3600, cf->esec%3600/60, cf->esec%60);
  }
  statusbar_push_file_msg(done_msg);
  g_free(done_msg);

  msg_len = strlen(name_ptr) + strlen(win_name_fmt) + 1;
  win_name = g_malloc(msg_len);
  snprintf(win_name, msg_len, win_name_fmt, name_ptr);
  set_main_window_name(win_name);
  g_free(win_name);
}

read_status_t
cf_read(capture_file *cf)
{
  int        err;
  gchar      *err_info;
  gchar      *name_ptr, *load_msg, *load_fmt = "%s";
  char       *errmsg;
  char        errmsg_errno[1024+1];
  gchar       err_str[2048+1];
  long        data_offset;
  progdlg_t  *progbar = NULL;
  gboolean    stop_flag;
  /*
   * XXX - should be "off_t", but Wiretap would need more work to handle
   * the full size of "off_t" on platforms where it's more than a "long"
   * as well.
   */
  long        file_pos;
  float       prog_val;
  int         fd;
  struct stat cf_stat;
  GTimeVal    start_time;
  gchar       status_str[100];
  int         progbar_nextstep;
  int         progbar_quantum;

  cum_bytes=0;
  reset_tap_listeners();
  tap_dfilter_dlg_update();
  name_ptr = get_basename(cf->filename);

  load_msg = g_strdup_printf(" Loading: %s", name_ptr);
  statusbar_push_file_msg(load_msg);
  g_free(load_msg);

  load_msg = g_strdup_printf(load_fmt, name_ptr);

  /* Update the progress bar when it gets to this value. */
  progbar_nextstep = 0;
  /* When we reach the value that triggers a progress bar update,
     bump that value by this amount. */
  progbar_quantum = cf->f_len/N_PROGBAR_UPDATES;

#ifndef O_BINARY
#define O_BINARY        0
#endif

  packet_list_freeze();

  stop_flag = FALSE;
  g_get_current_time(&start_time);

  while ((wtap_read(cf->wth, &err, &err_info, &data_offset))) {
    /* Update the progress bar, but do it only N_PROGBAR_UPDATES times;
       when we update it, we have to run the GTK+ main loop to get it
       to repaint what's pending, and doing so may involve an "ioctl()"
       to see if there's any pending input from an X server, and doing
       that for every packet can be costly, especially on a big file. */
    if (data_offset >= progbar_nextstep) {
        file_pos = lseek(cf->filed, 0, SEEK_CUR);
        prog_val = (gfloat) file_pos / (gfloat) cf->f_len;
        if (prog_val > 1.0) {
          /* The file probably grew while we were reading it.
             Update "cf->f_len", and try again. */
          fd = wtap_fd(cf->wth);
          if (fstat(fd, &cf_stat) >= 0) {
            cf->f_len = cf_stat.st_size;
            prog_val = (gfloat) file_pos / (gfloat) cf->f_len;
          }
          /* If it's still > 1, either the "fstat()" failed (in which
             case there's not much we can do about it), or the file
             *shrank* (in which case there's not much we can do about
             it); just clip the progress value at 1.0. */
          if (prog_val > 1.0)
            prog_val = 1.0;
        }
        if (progbar == NULL) {
          /* Create the progress bar if necessary */
          progbar = delayed_create_progress_dlg("Loading", load_msg,
            &stop_flag, &start_time, prog_val);
          if (progbar != NULL)
            g_free(load_msg);
        }
        if (progbar != NULL) {
          g_snprintf(status_str, sizeof(status_str),
                     "%luKB of %luKB", file_pos / 1024, cf->f_len / 1024);
          update_progress_dlg(progbar, prog_val, status_str);
        }
        progbar_nextstep += progbar_quantum;
    }

    if (stop_flag) {
      /* Well, the user decided to abort the read.  Destroy the progress
         bar, close the capture file, and return READ_ABORTED so our caller
         can do whatever is appropriate when that happens. */
      destroy_progress_dlg(progbar);
      cf->state = FILE_READ_ABORTED;    /* so that we're allowed to close it */
      packet_list_thaw();               /* undo our freeze */
      cf_close(cf);
      return (READ_ABORTED);
    }
    read_packet(cf, data_offset);
  }

  /* We're done reading the file; destroy the progress bar if it was created. */
  if (progbar == NULL)
    g_free(load_msg);
  else
    destroy_progress_dlg(progbar);

  /* We're done reading sequentially through the file. */
  cf->state = FILE_READ_DONE;

  /* Close the sequential I/O side, to free up memory it requires. */
  wtap_sequential_close(cf->wth);

  /* Allow the protocol dissectors to free up memory that they
   * don't need after the sequential run-through of the packets. */
  postseq_cleanup_all_protocols();

  /* Set the file encapsulation type now; we don't know what it is until
     we've looked at all the packets, as we don't know until then whether
     there's more than one type (and thus whether it's
     WTAP_ENCAP_PER_PACKET). */
  cf->lnk_t = wtap_file_encap(cf->wth);

  cf->current_frame = cf->first_displayed;
  packet_list_thaw();

  statusbar_pop_file_msg();
  set_display_filename(cf);

  /* Enable menu items that make sense if you have a capture file you've
     finished reading. */
  set_menus_for_capture_file(TRUE);
  set_menus_for_unsaved_capture_file(!cf->user_saved);

  /* Enable menu items that make sense if you have some captured packets. */
  set_menus_for_captured_packets(TRUE);

  /* If we have any displayed packets to select, select the first of those
     packets by making the first row the selected row. */
  if (cf->first_displayed != NULL)
    packet_list_select_row(0);

  if (err != 0) {
    /* Put up a message box noting that the read failed somewhere along
       the line.  Don't throw out the stuff we managed to read, though,
       if any. */
    switch (err) {

    case WTAP_ERR_UNSUPPORTED_ENCAP:
      errmsg = "The capture file is for a network type that Ethereal doesn't support.";
      break;

    case WTAP_ERR_CANT_READ:
      errmsg = "An attempt to read from the file failed for"
               " some unknown reason.";
      break;

    case WTAP_ERR_SHORT_READ:
      errmsg = "The capture file appears to have been cut short"
               " in the middle of a packet.";
      break;

    case WTAP_ERR_BAD_RECORD:
      snprintf(errmsg_errno, sizeof(errmsg_errno),
               "The capture file appears to be damaged or corrupt.\n(%s)",
               err_info);
      errmsg = errmsg_errno;
      break;

    default:
      snprintf(errmsg_errno, sizeof(errmsg_errno),
               "An error occurred while reading the"
               " capture file: %s.", wtap_strerror(err));
      errmsg = errmsg_errno;
      break;
    }
    snprintf(err_str, sizeof err_str, errmsg);
    simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK, err_str);
    return (READ_ERROR);
  } else
    return (READ_SUCCESS);
}

#ifdef HAVE_LIBPCAP
int
cf_start_tail(char *fname, gboolean is_tempfile, capture_file *cf)
{
  int     err;
  gchar *capture_msg;

  err = cf_open(fname, is_tempfile, cf);
  if (err == 0) {
    /* Disable menu items that make no sense if you're currently running
       a capture. */
    set_menus_for_capture_in_progress(TRUE);

    /* Enable menu items that make sense if you have some captured
       packets (yes, I know, we don't have any *yet*). */
    set_menus_for_captured_packets(TRUE);

    capture_msg = g_strdup_printf(" %s: <live capture in progress>", cf->iface);

    statusbar_push_file_msg(capture_msg);

    g_free(capture_msg);
  }
  return err;
}

read_status_t
cf_continue_tail(capture_file *cf, int to_read, int *err)
{
  long data_offset = 0;
  gchar *err_info;

  *err = 0;

  packet_list_freeze();

  while (to_read != 0 && (wtap_read(cf->wth, err, &err_info, &data_offset))) {
    if (cf->state == FILE_READ_ABORTED) {
      /* Well, the user decided to exit Ethereal.  Break out of the
         loop, and let the code below (which is called even if there
         aren't any packets left to read) exit. */
      break;
    }
    read_packet(cf, data_offset);
    to_read--;
  }

  packet_list_thaw();

  /* XXX - this cheats and looks inside the packet list to find the final
     row number. */
  if (auto_scroll_live && cf->plist_end != NULL)
    packet_list_moveto_end();

  if (cf->state == FILE_READ_ABORTED) {
    /* Well, the user decided to exit Ethereal.  Return READ_ABORTED
       so that our caller can kill off the capture child process;
       this will cause an EOF on the pipe from the child, so
       "cf_finish_tail()" will be called, and it will clean up
       and exit. */
    return READ_ABORTED;
  } else if (*err != 0) {
    /* We got an error reading the capture file.
       XXX - pop up a dialog box? */
    return (READ_ERROR);
  } else
    return (READ_SUCCESS);
}

read_status_t
cf_finish_tail(capture_file *cf, int *err)
{
  gchar *err_info;
  long data_offset;
  int         fd;
  struct stat cf_stat;

  packet_list_freeze();

  while ((wtap_read(cf->wth, err, &err_info, &data_offset))) {
    if (cf->state == FILE_READ_ABORTED) {
      /* Well, the user decided to abort the read.  Break out of the
         loop, and let the code below (which is called even if there
         aren't any packets left to read) exit. */
      break;
    }
    read_packet(cf, data_offset);
  }

  if (cf->state == FILE_READ_ABORTED) {
    /* Well, the user decided to abort the read.  We're only called
       when the child capture process closes the pipe to us (meaning
       it's probably exited), so we can just close the capture
       file; we return READ_ABORTED so our caller can do whatever
       is appropriate when that happens. */
    cf_close(cf);
    return READ_ABORTED;
  }

  packet_list_thaw();
  if (auto_scroll_live && cf->plist_end != NULL)
    /* XXX - this cheats and looks inside the packet list to find the final
       row number. */
    packet_list_moveto_end();

  /* We're done reading sequentially through the file. */
  cf->state = FILE_READ_DONE;

  /* we have to update the f_len field */
  /* Find the size of the file. */
  fd = wtap_fd(cf->wth);
  if (fstat(fd, &cf_stat) >= 0) {
      cf->f_len = cf_stat.st_size;
  }

  /* We're done reading sequentially through the file; close the
     sequential I/O side, to free up memory it requires. */
  wtap_sequential_close(cf->wth);

  /* Allow the protocol dissectors to free up memory that they
   * don't need after the sequential run-through of the packets. */
  postseq_cleanup_all_protocols();

  /* Set the file encapsulation type now; we don't know what it is until
     we've looked at all the packets, as we don't know until then whether
     there's more than one type (and thus whether it's
     WTAP_ENCAP_PER_PACKET). */
  cf->lnk_t = wtap_file_encap(cf->wth);

  /* Pop the "<live capture in progress>" message off the status bar. */
  statusbar_pop_file_msg();

  set_display_filename(cf);

  /* Enable menu items that make sense if you're not currently running
     a capture. */
  set_menus_for_capture_in_progress(FALSE);

  /* Enable menu items that make sense if you have a capture file
     you've finished reading. */
  set_menus_for_capture_file(TRUE);
  set_menus_for_unsaved_capture_file(!cf->user_saved);

  if (*err != 0) {
    /* We got an error reading the capture file.
       XXX - pop up a dialog box? */
    return (READ_ERROR);
  } else {
    return (READ_SUCCESS);
  }
}
#endif /* HAVE_LIBPCAP */

gchar *
cf_get_display_name(capture_file *cf)
{
  gchar *displayname;

  /* Return a name to use in displays */
  if (!cf->is_tempfile) {
    /* Get the last component of the file name, and use that. */
    if (cf->filename){
      displayname = get_basename(cf->filename);
      
      /* Add this filename to the list of recent files in the "Recent Files" submenu */
      add_menu_recent_capture_file(cf->filename);
    } else {
      displayname="(No file)";
    }
  } else {
    /* The file we read is a temporary file from a live capture;
       we don't mention its name. */
    displayname = "(Untitled)";
  }
  return displayname;
}

typedef struct {
  color_filter_t *colorf;
  epan_dissect_t *edt;
} apply_color_filter_args;

/*
 * If no color filter has been applied, apply this one.
 * (The "if no color filter has been applied" is to handle the case where
 * more than one color filter matches the packet.)
 */
static void
apply_color_filter(gpointer filter_arg, gpointer argp)
{
  color_filter_t *colorf = filter_arg;
  apply_color_filter_args *args = argp;

  if (colorf->c_colorfilter != NULL && args->colorf == NULL) {
    if (dfilter_apply_edt(colorf->c_colorfilter, args->edt))
      args->colorf = colorf;
  }
}

static int
add_packet_to_packet_list(frame_data *fdata, capture_file *cf,
        union wtap_pseudo_header *pseudo_header, const guchar *buf,
        gboolean refilter)
{
  apply_color_filter_args args;
  gint          row;
  gboolean      create_proto_tree = FALSE;
  epan_dissect_t *edt;

  /* just add some value here until we know if it is being displayed or not */
  fdata->cum_bytes  = cum_bytes + fdata->pkt_len;

  /* We don't yet have a color filter to apply. */
  args.colorf = 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 (!firstsec && !firstusec) {
    firstsec  = fdata->abs_secs;
    firstusec = fdata->abs_usecs;
  }
  /* if this frames is marked as a reference time frame, reset
     firstsec and firstusec to this frame */
  if(fdata->flags.ref_time){
    firstsec  = fdata->abs_secs;
    firstusec = fdata->abs_usecs;
  }

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

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

  /* If it's greater than the current elapsed time, set the elapsed time
     to it (we check for "greater than" so as not to be confused by
     time moving backwards). */
  if ((gint32)cf->esec < fdata->rel_secs
  || ((gint32)cf->esec == fdata->rel_secs && (gint32)cf->eusec < fdata->rel_usecs)) {
    cf->esec = fdata->rel_secs;
    cf->eusec = fdata->rel_usecs;
  }

  /* Get the time elapsed between the previous displayed packet and
     this packet. */
  compute_timestamp_diff(&fdata->del_secs, &fdata->del_usecs,
        fdata->abs_secs, fdata->abs_usecs, prevsec, prevusec);

  /* If either

        we have a display filter and are re-applying it;

        we have a list of color filters;

        we have tap listeners;

     allocate a protocol tree root node, so that we'll construct
     a protocol tree against which a filter expression can be
     evaluated. */
  if ((cf->dfcode != NULL && refilter) || filter_list != NULL
        || num_tap_filters != 0)
          create_proto_tree = TRUE;

  /* Dissect the frame. */
  edt = epan_dissect_new(create_proto_tree, FALSE);

  if (cf->dfcode != NULL && refilter) {
      epan_dissect_prime_dfilter(edt, cf->dfcode);
  }
  if (filter_list) {
      filter_list_prime_edt(edt);
  }
  tap_queue_init(edt);
  epan_dissect_run(edt, pseudo_header, buf, fdata, &cf->cinfo);
  tap_push_tapped_queue(edt);

  /* If we have a display filter, apply it if we're refiltering, otherwise
     leave the "passed_dfilter" flag alone.

     If we don't have a display filter, set "passed_dfilter" to 1. */
  if (cf->dfcode != NULL) {
    if (refilter) {
      if (cf->dfcode != NULL)
        fdata->flags.passed_dfilter = dfilter_apply_edt(cf->dfcode, edt) ? 1 : 0;
      else
        fdata->flags.passed_dfilter = 1;
    }
  } else
    fdata->flags.passed_dfilter = 1;

  /* If we have color filters, and the frame is to be displayed, apply
     the color filters. */
  if (fdata->flags.passed_dfilter) {
    if (filter_list != NULL) {
      args.edt = edt;
      g_slist_foreach(filter_list, apply_color_filter, &args);
    }
  }


  if( (fdata->flags.passed_dfilter) 
   || (edt->pi.fd->flags.ref_time) ){
    /* This frame either passed the display filter list or is marked as
       a time reference frame.  All time reference frames are displayed
       even if they dont pass the display filter */
    /* if this was a TIME REF frame we should reset the cul bytes field */
    if(edt->pi.fd->flags.ref_time){
      cum_bytes = fdata->pkt_len;
      fdata->cum_bytes  = cum_bytes;
    }

    /* increase cum_bytes with this packets length */
    cum_bytes += fdata->pkt_len;

    epan_dissect_fill_in_columns(edt);

    /* If we haven't yet seen the first frame, this is it.

       XXX - we must do this before we add the row to the display,
       as, if the display's GtkCList's selection mode is
       GTK_SELECTION_BROWSE, when the first entry is added to it,
       "select_packet()" will be called, and it will fetch the row
       data for the 0th row, and will get a null pointer rather than
       "fdata", as "gtk_clist_append()" won't yet have returned and
       thus "gtk_clist_set_row_data()" won't yet have been called.

       We thus need to leave behind bread crumbs so that
       "select_packet()" can find this frame.  See the comment
       in "select_packet()". */
    if (cf->first_displayed == NULL)
      cf->first_displayed = fdata;

    /* This is the last frame we've seen so far. */
    cf->last_displayed = fdata;

    row = packet_list_append(cf->cinfo.col_data, fdata);

    /* If the packet matches a color filter,
     * store matching color_filter_t object in frame data. */
    if (filter_list != NULL && (args.colorf != NULL)) {
      /* add the matching colorfilter to the frame data */
      fdata->color_filter = args.colorf;
      /* If packet is marked, use colors from preferences */
      if (fdata->flags.marked) {
          packet_list_set_colors(row, &prefs.gui_marked_fg, &prefs.gui_marked_bg);
      } else /* if (filter_list != NULL && (args.colorf != NULL)) */ {
          packet_list_set_colors(row, &(args.colorf->fg_color),
              &(args.colorf->bg_color));
      }
    } else {
      /* No color filter match */
      fdata->color_filter = NULL;
      if (fdata->flags.marked) {
          packet_list_set_colors(row, &prefs.gui_marked_fg, &prefs.gui_marked_bg);
      }
    }

    /* Set the time of the previous displayed frame to the time of this
       frame. */
    prevsec = fdata->abs_secs;
    prevusec = fdata->abs_usecs;

    cf->displayed_count++;
  } else {
    /* This frame didn't pass the display filter, so it's not being added
       to the clist, and thus has no row. */
    row = -1;
  }
  epan_dissect_free(edt);
  return row;
}

static void
read_packet(capture_file *cf, long offset)
{
  const struct wtap_pkthdr *phdr = wtap_phdr(cf->wth);
  union wtap_pseudo_header *pseudo_header = wtap_pseudoheader(cf->wth);
  const guchar *buf = wtap_buf_ptr(cf->wth);
  frame_data   *fdata;
  int           passed;
  frame_data   *plist_end;
  epan_dissect_t *edt;

  /* Allocate the next list entry, and add it to the list. */
  fdata = g_mem_chunk_alloc(cf->plist_chunk);

  fdata->next = NULL;
  fdata->prev = NULL;
  fdata->pfd  = NULL;
  fdata->pkt_len  = phdr->len;
  fdata->cap_len  = phdr->caplen;
  fdata->file_off = offset;
  fdata->lnk_t = phdr->pkt_encap;
  fdata->abs_secs  = phdr->ts.tv_sec;
  fdata->abs_usecs = phdr->ts.tv_usec;
  fdata->flags.encoding = CHAR_ASCII;
  fdata->flags.visited = 0;
  fdata->flags.marked = 0;
  fdata->flags.ref_time = 0;

  passed = TRUE;
  if (cf->rfcode) {
    edt = epan_dissect_new(TRUE, FALSE);
    epan_dissect_prime_dfilter(edt, cf->rfcode);
    epan_dissect_run(edt, pseudo_header, buf, fdata, NULL);
    passed = dfilter_apply_edt(cf->rfcode, edt);
    epan_dissect_free(edt);
  }
  if (passed) {
    plist_end = cf->plist_end;
    fdata->prev = plist_end;
    if (plist_end != NULL)
      plist_end->next = fdata;
    else
      cf->plist = fdata;
    cf->plist_end = fdata;

    cf->count++;
    fdata->num = cf->count;
    add_packet_to_packet_list(fdata, cf, pseudo_header, buf, TRUE);
  } else {
    /* XXX - if we didn't have read filters, or if we could avoid
       allocating the "frame_data" structure until we knew whether
       the frame passed the read filter, we could use a G_ALLOC_ONLY
       memory chunk...

       ...but, at least in one test I did, where I just made the chunk
       a G_ALLOC_ONLY chunk and read in a huge capture file, it didn't
       seem to save a noticeable amount of time or space. */
    g_mem_chunk_free(cf->plist_chunk, fdata);
  }
}

gboolean
filter_packets(capture_file *cf, gchar *dftext, gboolean force)
{
  dfilter_t *dfcode;
  char      *filter_new = dftext ? dftext : "";
  char      *filter_old = cf->dfilter ? cf->dfilter : "";

  /* if new filter equals old one, do nothing unless told to do so */
  if (!force && strcmp(filter_new, filter_old) == 0) {
    return TRUE;
  }

  if (dftext == NULL) {
    /* The new filter is an empty filter (i.e., display all packets). */
    dfcode = NULL;
  } else {
    /*
     * We have a filter; make a copy of it (as we'll be saving it),
     * and try to compile it.
     */
    dftext = g_strdup(dftext);
    if (!dfilter_compile(dftext, &dfcode)) {
      /* The attempt failed; report an error. */
      gchar *safe_dftext = simple_dialog_format_message(dftext);
      gchar *safe_dfilter_error_msg = simple_dialog_format_message(
          dfilter_error_msg);
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK, 
          "%s%s%s\n"
          "\n"
          "The following display filter is not a valid display filter:\n%s\n"
          "See the help for a description of the display filter syntax.",
          simple_dialog_primary_start(), safe_dfilter_error_msg,
          simple_dialog_primary_end(), safe_dftext);
      g_free(safe_dfilter_error_msg);
      g_free(safe_dftext);
      g_free(dftext);
      return FALSE;
    }

    /* Was it empty? */
    if (dfcode == NULL) {
      /* Yes - free the filter text, and set it to null. */
      g_free(dftext);
      dftext = NULL;
    }
  }

  /* We have a valid filter.  Replace the current filter. */
  if (cf->dfilter != NULL)
    g_free(cf->dfilter);
  cf->dfilter = dftext;
  if (cf->dfcode != NULL)
    dfilter_free(cf->dfcode);
  cf->dfcode = dfcode;

  /* Now rescan the packet list, applying the new filter, but not
     throwing away information constructed on a previous pass. */
  if (dftext == NULL) {
    rescan_packets(cf, "Resetting", "Filter", TRUE, FALSE);
  } else {
    rescan_packets(cf, "Filtering", dftext, TRUE, FALSE);
  }
  return TRUE;
}

void
colorize_packets(capture_file *cf)
{
  rescan_packets(cf, "Colorizing", "all packets", FALSE, FALSE);
}

void
reftime_packets(capture_file *cf)
{
  rescan_packets(cf, "Updating Reftime", "all packets", FALSE, FALSE);
}

void
redissect_packets(capture_file *cf)
{
  rescan_packets(cf, "Reprocessing", "all packets", TRUE, TRUE);
}

/* Rescan the list of packets, reconstructing the CList.

   "action" describes why we're doing this; it's used in the progress
   dialog box.

   "action_item" describes what we're doing; it's used in the progress
   dialog box.

   "refilter" is TRUE if we need to re-evaluate the filter expression.

   "redissect" is TRUE if we need to make the dissectors reconstruct
   any state information they have (because a preference that affects
   some dissector has changed, meaning some dissector might construct
   its state differently from the way it was constructed the last time). */
static void
rescan_packets(capture_file *cf, const char *action, const char *action_item,
                gboolean refilter, gboolean redissect)
{
  frame_data *fdata;
  progdlg_t  *progbar = NULL;
  gboolean    stop_flag;
  int         count;
  int         err;
  gchar      *err_info;
  frame_data *selected_frame, *preceding_frame, *following_frame, *prev_frame;
  int         selected_row, prev_row, preceding_row, following_row;
  gboolean    selected_frame_seen;
  int         row;
  float       prog_val;
  GTimeVal    start_time;
  gchar       status_str[100];
  int         progbar_nextstep;
  int         progbar_quantum;

  cum_bytes=0;
  reset_tap_listeners();
  /* Which frame, if any, is the currently selected frame?
     XXX - should the selected frame or the focus frame be the "current"
     frame, that frame being the one from which "Find Frame" searches
     start? */
  selected_frame = cf->current_frame;

  /* We don't yet know what row that frame will be on, if any, after we
     rebuild the clist, however. */
  selected_row = -1;

  if (redissect) {
    /* We need to re-initialize all the state information that protocols
       keep, because some preference that controls a dissector has changed,
       which might cause the state information to be constructed differently
       by that dissector. */

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

  /* Freeze the packet list while we redo it, so we don't get any
     screen updates while it happens. */
  packet_list_freeze();

  /* Clear it out. */
  packet_list_clear();

  /* We don't yet know which will be the first and last frames displayed. */
  cf->first_displayed = NULL;
  cf->last_displayed = NULL;

  /* We currently don't display any packets */
  cf->displayed_count = 0;

  /* Iterate through the list of frames.  Call a routine for each frame
     to check whether it should be displayed and, if so, add it to
     the display list. */
  firstsec = 0;
  firstusec = 0;
  prevsec = 0;
  prevusec = 0;

  /* Update the progress bar when it gets to this value. */
  progbar_nextstep = 0;
  /* When we reach the value that triggers a progress bar update,
     bump that value by this amount. */
  progbar_quantum = cf->count/N_PROGBAR_UPDATES;
  /* Count of packets at which we've looked. */
  count = 0;

  stop_flag = FALSE;
  g_get_current_time(&start_time);

  row = -1;             /* no previous row yet */
  prev_row = -1;
  prev_frame = NULL;

  preceding_row = -1;
  preceding_frame = NULL;
  following_row = -1;
  following_frame = NULL;

  selected_frame_seen = FALSE;

  for (fdata = cf->plist; fdata != NULL; fdata = fdata->next) {
    /* Update the progress bar, but do it only N_PROGBAR_UPDATES times;
       when we update it, we have to run the GTK+ main loop to get it
       to repaint what's pending, and doing so may involve an "ioctl()"
       to see if there's any pending input from an X server, and doing
       that for every packet can be costly, especially on a big file. */
    if (count >= progbar_nextstep) {
      /* let's not divide by zero. I should never be started
       * with count == 0, so let's assert that
       */
      g_assert(cf->count > 0);
      prog_val = (gfloat) count / cf->count;

      if (progbar == NULL)
        /* Create the progress bar if necessary */
        progbar = delayed_create_progress_dlg(action, action_item, &stop_flag,
          &start_time, prog_val);

      if (progbar != NULL) {
        g_snprintf(status_str, sizeof(status_str),
                  "%4u of %u frames", count, cf->count);
        update_progress_dlg(progbar, prog_val, status_str);
      }

      progbar_nextstep += progbar_quantum;
    }

    if (stop_flag) {
      /* Well, the user decided to abort the filtering.  Just stop.

         XXX - go back to the previous filter?  Users probably just
         want not to wait for a filtering operation to finish;
         unless we cancel by having no filter, reverting to the
         previous filter will probably be even more expensive than
         continuing the filtering, as it involves going back to the
         beginning and filtering, and even with no filter we currently
         have to re-generate the entire clist, which is also expensive.

         I'm not sure what Network Monitor does, but it doesn't appear
         to give you an unfiltered display if you cancel. */
      break;
    }

    count++;

    if (redissect) {
      /* Since all state for the frame was destroyed, mark the frame
       * as not visited, free the GSList referring to the state
       * data (the per-frame data itself was freed by
       * "init_dissection()"), and null out the GSList pointer. */
      fdata->flags.visited = 0;
      if (fdata->pfd) {
        g_slist_free(fdata->pfd);
        fdata->pfd = NULL;
      }
    }

    if (!wtap_seek_read (cf->wth, fdata->file_off, &cf->pseudo_header,
        cf->pd, fdata->cap_len, &err, &err_info)) {
        simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                      cf_read_error_message(err, err_info), cf->filename);
        break;
    }

    /* If the previous frame is displayed, and we haven't yet seen the
       selected frame, remember that frame - it's the closest one we've
       yet seen before the selected frame. */
    if (prev_row != -1 && !selected_frame_seen) {
      preceding_row = prev_row;
      preceding_frame = prev_frame;
    }
    row = add_packet_to_packet_list(fdata, cf, &cf->pseudo_header, cf->pd,
                                        refilter);

    /* If this frame is displayed, and this is the first frame we've
       seen displayed after the selected frame, remember this frame -
       it's the closest one we've yet seen at or after the selected
       frame. */
    if (row != -1 && selected_frame_seen && following_row == -1) {
      following_row = row;
      following_frame = fdata;
    }
    if (fdata == selected_frame) {
      selected_row = row;
      selected_frame_seen = TRUE;
    }

    /* Remember this row/frame - it'll be the previous row/frame
       on the next pass through the loop. */
    prev_row = row;
    prev_frame = fdata;
  }

  if (redissect) {
    /* Clear out what remains of the visited flags and per-frame data
       pointers.

       XXX - that may cause various forms of bogosity when dissecting
       these frames, as they won't have been seen by this sequential
       pass, but the only alternative I see is to keep scanning them
       even though the user requested that the scan stop, and that
       would leave the user stuck with an Ethereal grinding on
       until it finishes.  Should we just stick them with that? */
    for (; fdata != NULL; fdata = fdata->next) {
      fdata->flags.visited = 0;
      if (fdata->pfd) {
        g_slist_free(fdata->pfd);
        fdata->pfd = NULL;
      }
    }
  }

  /* We're done filtering the packets; destroy the progress bar if it
     was created. */
  if (progbar != NULL)
    destroy_progress_dlg(progbar);

  /* Unfreeze the packet list. */
  packet_list_thaw();

  if (selected_row == -1) {
    /* The selected frame didn't pass the filter. */
    if (selected_frame == NULL) {
      /* That's because there *was* no selected frame.  Make the first
         displayed frame the current frame. */
      selected_row = 0;
    } else {
      /* Find the nearest displayed frame to the selected frame (whether
         it's before or after that frame) and make that the current frame.
         If the next and previous displayed frames are equidistant from the
         selected frame, choose the next one. */
      g_assert(following_frame == NULL ||
               following_frame->num >= selected_frame->num);
      g_assert(preceding_frame == NULL ||
               preceding_frame->num <= selected_frame->num);
      if (following_frame == NULL) {
        /* No frame after the selected frame passed the filter, so we
           have to select the last displayed frame before the selected
           frame. */
        selected_row = preceding_row;
      } else if (preceding_frame == NULL) {
        /* No frame before the selected frame passed the filter, so we
           have to select the first displayed frame after the selected
           frame. */
        selected_row = following_row;
      } else {
        /* Choose the closer of the last displayed frame before the
           selected frame and the first displayed frame after the
           selected frame; in case of a tie, choose the first displayed
           frame after the selected frame. */
        if (following_frame->num - selected_frame->num <=
            selected_frame->num - preceding_frame->num) {
          selected_row = following_row;
        } else {
          /* The previous frame is closer to the selected frame than the
             next frame. */
          selected_row = preceding_row;
        }
      }
    }
  }

  if (selected_row == -1) {
    /* There are no frames displayed at all. */
    unselect_packet(cf);
  } else {
    /* Either the frame that was selected passed the filter, or we've
       found the nearest displayed frame to that frame.  Select it, make
       it the focus row, and make it visible. */
    packet_list_set_selected_row(selected_row);
  }
}

typedef enum {
  PSP_FINISHED,
  PSP_STOPPED,
  PSP_FAILED
} psp_return_t;

psp_return_t
process_specified_packets(capture_file *cf, packet_range_t *range,
    const char *string1, const char *string2,
    gboolean (*callback)(capture_file *, frame_data *,
                         union wtap_pseudo_header *, const guint8 *, void *),
    void *callback_args)
{
  frame_data *fdata;
  int         err;
  gchar      *err_info;
  union wtap_pseudo_header pseudo_header;
  guint8      pd[WTAP_MAX_PACKET_SIZE+1];
  psp_return_t ret = PSP_FINISHED;

  progdlg_t  *progbar = NULL;
  int         progbar_count;
  float       progbar_val;
  gboolean    progbar_stop_flag;
  GTimeVal    progbar_start_time;
  gchar       progbar_status_str[100];
  int         progbar_nextstep;
  int         progbar_quantum;
  range_process_e process_this;

  /* Update the progress bar when it gets to this value. */
  progbar_nextstep = 0;
  /* When we reach the value that triggers a progress bar update,
     bump that value by this amount. */
  progbar_quantum = cf->count/N_PROGBAR_UPDATES;
  /* Count of packets at which we've looked. */
  progbar_count = 0;

  progbar_stop_flag = FALSE;
  g_get_current_time(&progbar_start_time);

  packet_range_process_init(range);

  /* Iterate through the list of packets, printing the packets that
     were selected by the current display filter.  */
  for (fdata = cf->plist; fdata != NULL; fdata = fdata->next) {
    /* Update the progress bar, but do it only N_PROGBAR_UPDATES times;
       when we update it, we have to run the GTK+ main loop to get it
       to repaint what's pending, and doing so may involve an "ioctl()"
       to see if there's any pending input from an X server, and doing
       that for every packet can be costly, especially on a big file. */
    if (progbar_count >= progbar_nextstep) {
      /* let's not divide by zero. I should never be started
       * with count == 0, so let's assert that
       */
      g_assert(cf->count > 0);
      progbar_val = (gfloat) progbar_count / cf->count;

      if (progbar == NULL)
        /* Create the progress bar if necessary */
        progbar = delayed_create_progress_dlg(string1, string2,
                                              &progbar_stop_flag,
                                              &progbar_start_time,
                                              progbar_val);

      if (progbar != NULL) {
        g_snprintf(progbar_status_str, sizeof(progbar_status_str),
                   "%4u of %u packets", progbar_count, cf->count);
        update_progress_dlg(progbar, progbar_val, progbar_status_str);
      }

      progbar_nextstep += progbar_quantum;
    }

    if (progbar_stop_flag) {
      /* Well, the user decided to abort the operation.  Just stop,
         and arrange to return TRUE to our caller, so they know it
         was stopped explicitly. */
      ret = PSP_STOPPED;
      break;
    }

    progbar_count++;

    /* do we have to process this packet? */
    process_this = packet_range_process_packet(range, fdata);
    if (process_this == range_process_next) {
        /* this packet uninteresting, continue with next one */
        continue;
    } else if (process_this == range_processing_finished) {
        /* all interesting packets processed, stop the loop */
        break;
    }

    /* Get the packet */
    if (!wtap_seek_read(cf->wth, fdata->file_off, &pseudo_header,
                        pd, fdata->cap_len, &err, &err_info)) {
      /* Attempt to get the packet failed. */
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    cf_read_error_message(err, err_info), cf->filename);
      ret = PSP_FAILED;
      break;
    }
    /* Process the packet */
    if (!callback(cf, fdata, &pseudo_header, pd, callback_args)) {
      /* Callback failed.  We assume it reported the error appropriately. */
      ret = PSP_FAILED;
      break;
    }
  }

  /* We're done printing the packets; destroy the progress bar if
     it was created. */
  if (progbar != NULL)
    destroy_progress_dlg(progbar);

  return ret;
}

static gboolean
retap_packet(capture_file *cf _U_, frame_data *fdata,
             union wtap_pseudo_header *pseudo_header, const guint8 *pd,
             void *argsp _U_)
{
  epan_dissect_t *edt;

  /* If we have tap listeners, allocate a protocol tree root node, so that
     we'll construct a protocol tree against which a filter expression can
     be evaluated. */
  edt = epan_dissect_new(num_tap_filters != 0, FALSE);
  tap_queue_init(edt);
  epan_dissect_run(edt, pseudo_header, pd, fdata, NULL);
  tap_push_tapped_queue(edt);
  epan_dissect_free(edt);

  return TRUE;
}

int
retap_packets(capture_file *cf)
{
  packet_range_t range;

  /* Reset the tap listeners. */
  reset_tap_listeners();

  /* Iterate through the list of packets, dissecting all packets and
     re-running the taps. */
  packet_range_init(&range);
  packet_range_process_init(&range);
  switch (process_specified_packets(cf, &range, "Refiltering statistics on",
                                    "all packets", retap_packet,
                                    NULL)) {
  case PSP_FINISHED:
    /* Completed successfully. */
    break;

  case PSP_STOPPED:
    /* Well, the user decided to abort the refiltering.
       Return FALSE so our caller knows they did that. */
    return FALSE;

  case PSP_FAILED:
    /* Error while retapping. */
    return FALSE;
  }

  return TRUE;
}

typedef struct {
  print_args_t *print_args;
  FILE         *print_fh;
  gboolean      print_header_line;
  char         *header_line_buf;
  int           header_line_buf_len;
  gboolean      print_formfeed;
  gboolean      print_separator;
  char         *line_buf;
  int           line_buf_len;
  gint         *col_widths;
} print_callback_args_t;

static gboolean
print_packet(capture_file *cf, frame_data *fdata,
             union wtap_pseudo_header *pseudo_header, const guint8 *pd,
             void *argsp)
{
  print_callback_args_t *args = argsp;
  epan_dissect_t *edt;
  int             i;
  char           *cp;
  int             line_len;
  int             column_len;
  int             cp_off;
  gboolean        proto_tree_needed;

  proto_tree_needed = 
      args->print_args->print_dissections != print_dissections_none || args->print_args->print_hex;

  /* Fill in the column information, but don't bother creating
     the logical protocol tree. */
  edt = epan_dissect_new(proto_tree_needed, proto_tree_needed);
  epan_dissect_run(edt, pseudo_header, pd, fdata, &cf->cinfo);
  epan_dissect_fill_in_columns(edt);

  if (args->print_formfeed) {
    print_formfeed(args->print_fh, args->print_args->format);
  } else {
      if (args->print_separator)
        print_line(args->print_fh, 0, args->print_args->format, "");
  }

  if (args->print_args->print_summary || args->print_args->format == PR_FMT_PS) {
    if (args->print_header_line) {
      print_line(args->print_fh, 0, args->print_args->format,
                 args->header_line_buf);
      args->print_header_line = FALSE;  /* we might not need to print any more */
    }
    cp = &args->line_buf[0];
    line_len = 0;
    for (i = 0; i < cf->cinfo.num_cols; i++) {
      /* Find the length of the string for this column. */
      column_len = strlen(cf->cinfo.col_data[i]);
      if (args->col_widths[i] > column_len)
         column_len = args->col_widths[i];

      /* Make sure there's room in the line buffer for the column; if not,
         double its length. */
      line_len += column_len + 1;       /* "+1" for space */
      if (line_len > args->line_buf_len) {
        cp_off = cp - args->line_buf;
        args->line_buf_len = 2 * line_len;
        args->line_buf = g_realloc(args->line_buf, args->line_buf_len + 1);
        cp = args->line_buf + cp_off;
      }

      /* Right-justify the packet number column. */
      if (cf->cinfo.col_fmt[i] == COL_NUMBER)
        sprintf(cp, "%*s", args->col_widths[i], cf->cinfo.col_data[i]);
      else
        sprintf(cp, "%-*s", args->col_widths[i], cf->cinfo.col_data[i]);
      cp += column_len;
      if (i != cf->cinfo.num_cols - 1)
        *cp++ = ' ';
    }
    *cp = '\0';

    print_packet_header(args->print_fh, args->print_args->format, fdata->num, args->line_buf);

    if (args->print_args->print_summary) {
        print_line(args->print_fh, 0, args->print_args->format, args->line_buf);
    }
  } /* if (print_summary) */
  
  if (args->print_args->print_dissections != print_dissections_none) {
    if (args->print_args->print_summary) {
      /* Separate the summary line from the tree with a blank line. */
      print_line(args->print_fh, 0, args->print_args->format, "");
    }

    /* Print the information in that tree. */
    proto_tree_print(args->print_args, edt, args->print_fh);

    /* Print a blank line if we print anything after this (aka more than one packet). */
    args->print_separator = TRUE;

    /* Print a header line if we print any more packet summaries */
    args->print_header_line = TRUE;
  }

  if (args->print_args->print_hex) {
    /* Print the full packet data as hex. */
    print_hex_data(args->print_fh, args->print_args->format, edt);

    /* Print a blank line if we print anything after this (aka more than one packet). */
    args->print_separator = TRUE;

    /* Print a header line if we print any more packet summaries */
    args->print_header_line = TRUE;
  } /* if (print_summary) */

  epan_dissect_free(edt);

  /* do we want to have a formfeed between each packet from now on? */
  if(args->print_args->print_formfeed) {
    args->print_formfeed = TRUE;
  }

  return !ferror(args->print_fh);
}

pp_return_t
print_packets(capture_file *cf, print_args_t *print_args)
{
  int         i;
  print_callback_args_t callback_args;
  gint        data_width;
  char        *cp;
  int         cp_off;
  int         column_len;
  int         line_len;
  psp_return_t ret;

  if(print_args->to_file) {
      callback_args.print_fh = open_print_dest(print_args->to_file,
                                               print_args->file);
  } else {
      callback_args.print_fh = open_print_dest(print_args->to_file,
                                               print_args->cmd);
  }
  if (callback_args.print_fh == NULL)
    return PP_OPEN_ERROR;       /* attempt to open destination failed */

  print_preamble(callback_args.print_fh, print_args->format, cf->filename);
  if (ferror(callback_args.print_fh)) {
    close_print_dest(print_args->to_file, callback_args.print_fh);
    return PP_WRITE_ERROR;
  }

  callback_args.print_args = print_args;
  callback_args.print_header_line = TRUE;
  callback_args.header_line_buf = NULL;
  callback_args.header_line_buf_len = 256;
  callback_args.print_formfeed = FALSE;
  callback_args.print_separator = FALSE;
  callback_args.line_buf = NULL;
  callback_args.line_buf_len = 256;
  callback_args.col_widths = NULL;
  if (print_args->print_summary || print_args->format == PR_FMT_PS) {
    /* We're printing packet summaries.  Allocate the header line buffer
       and get the column widths. */
    callback_args.header_line_buf = g_malloc(callback_args.header_line_buf_len + 1);

    /* Find the widths for each of the columns - maximum of the
       width of the title and the width of the data - and construct
       a buffer with a line containing the column titles. */
    callback_args.col_widths = (gint *) g_malloc(sizeof(gint) * cf->cinfo.num_cols);
    cp = &callback_args.header_line_buf[0];
    line_len = 0;
    for (i = 0; i < cf->cinfo.num_cols; i++) {
      /* Don't pad the last column. */
      if (i == cf->cinfo.num_cols - 1)
        callback_args.col_widths[i] = 0;
      else {
        callback_args.col_widths[i] = strlen(cf->cinfo.col_title[i]);
        data_width = get_column_char_width(get_column_format(i));
        if (data_width > callback_args.col_widths[i])
          callback_args.col_widths[i] = data_width;
      }

      /* Find the length of the string for this column. */
      column_len = strlen(cf->cinfo.col_title[i]);
      if (callback_args.col_widths[i] > column_len)
        column_len = callback_args.col_widths[i];

      /* Make sure there's room in the line buffer for the column; if not,
         double its length. */
      line_len += column_len + 1;       /* "+1" for space */
      if (line_len > callback_args.header_line_buf_len) {
        cp_off = cp - callback_args.header_line_buf;
        callback_args.header_line_buf_len = 2 * line_len;
        callback_args.header_line_buf = g_realloc(callback_args.header_line_buf,
                                                  callback_args.header_line_buf_len + 1);
        cp = callback_args.header_line_buf + cp_off;
      }

      /* Right-justify the packet number column. */
/*      if (cf->cinfo.col_fmt[i] == COL_NUMBER)
        sprintf(cp, "%*s", callback_args.col_widths[i], cf->cinfo.col_title[i]);
      else*/
        sprintf(cp, "%-*s", callback_args.col_widths[i], cf->cinfo.col_title[i]);
      cp += column_len;
      if (i != cf->cinfo.num_cols - 1)
        *cp++ = ' ';
    }
    *cp = '\0';

    /* Now start out the main line buffer with the same length as the
       header line buffer. */
    callback_args.line_buf_len = callback_args.header_line_buf_len;
    callback_args.line_buf = g_malloc(callback_args.line_buf_len + 1);
  } /* if (print_summary) */

  /* Iterate through the list of packets, printing the packets we were
     told to print. */
  ret = process_specified_packets(cf, &print_args->range, "Printing",
                                  "selected packets", print_packet,
                                  &callback_args);

  if (callback_args.header_line_buf != NULL)
    g_free(callback_args.header_line_buf);
  if (callback_args.line_buf != NULL)
    g_free(callback_args.line_buf);
  if (callback_args.col_widths != NULL)
    g_free(callback_args.col_widths);

  switch (ret) {

  case PSP_FINISHED:
    /* Completed successfully. */
    break;

  case PSP_STOPPED:
    /* Well, the user decided to abort the printing.

       XXX - note that what got generated before they did that
       will get printed if we're piping to a print program; we'd
       have to write to a file and then hand that to the print
       program to make it actually not print anything. */
    break;

  case PSP_FAILED:
    /* Error while printing.

       XXX - note that what got generated before they did that
       will get printed if we're piping to a print program; we'd
       have to write to a file and then hand that to the print
       program to make it actually not print anything. */
    close_print_dest(print_args->to_file, callback_args.print_fh);
    return PP_WRITE_ERROR;
  }

  print_finale(callback_args.print_fh, print_args->format);
  if (ferror(callback_args.print_fh)) {
    close_print_dest(print_args->to_file, callback_args.print_fh);
    return PP_WRITE_ERROR;
  }

  close_print_dest(print_args->to_file, callback_args.print_fh);

  return PP_OK;
}

/* Scan through the packet list and change all columns that use the
   "command-line-specified" time stamp format to use the current
   value of that format. */
void
change_time_formats(capture_file *cf)
{
  frame_data *fdata;
  progdlg_t  *progbar = NULL;
  gboolean    stop_flag;
  int         count;
  int         row;
  int         i;
  float       prog_val;
  GTimeVal    start_time;
  gchar       status_str[100];
  int         progbar_nextstep;
  int         progbar_quantum;
  int         first, last;
  gboolean    sorted_by_frame_column;

  /* Are there any columns with time stamps in the "command-line-specified"
     format?

     XXX - we have to force the "column is writable" flag on, as it
     might be off from the last frame that was dissected. */
  col_set_writable(&cf->cinfo, TRUE);
  if (!check_col(&cf->cinfo, COL_CLS_TIME)) {
    /* No, there aren't any columns in that format, so we have no work
       to do. */
    return;
  }
  first = cf->cinfo.col_first[COL_CLS_TIME];
  g_assert(first >= 0);
  last = cf->cinfo.col_last[COL_CLS_TIME];

  /* Freeze the packet list while we redo it, so we don't get any
     screen updates while it happens. */
  packet_list_freeze();

  /* Update the progress bar when it gets to this value. */
  progbar_nextstep = 0;
  /* When we reach the value that triggers a progress bar update,
     bump that value by this amount. */
  progbar_quantum = cf->count/N_PROGBAR_UPDATES;
  /* Count of packets at which we've looked. */
  count = 0;

  /*  If the rows are currently sorted by the frame column then we know
   *  the row number of each packet: it's the row number of the previously
   *  displayed packet + 1.
   *
   *  Otherwise, if the display is sorted by a different column then we have
   *  to use the O(N) packet_list_find_row_from_data() (thus making the job
   *  of changing the time display format O(N**2)).
   *
   *  (XXX - In fact it's still O(N**2) because gtk_clist_set_text() takes
   *  the row number and walks that many elements down the clist to find
   *  the appropriate element.)
   */
  sorted_by_frame_column = FALSE;
  for (i = 0; i < cf->cinfo.num_cols; i++) {
    if (cf->cinfo.col_fmt[i] == COL_NUMBER)
    {
      sorted_by_frame_column = (i == packet_list_get_sort_column());
      break;
    }
  }

  stop_flag = FALSE;
  g_get_current_time(&start_time);

  /* Iterate through the list of packets, checking whether the packet
     is in a row of the summary list and, if so, whether there are
     any columns that show the time in the "command-line-specified"
     format and, if so, update that row. */
  for (fdata = cf->plist, row = -1; fdata != NULL; fdata = fdata->next) {
    /* Update the progress bar, but do it only N_PROGBAR_UPDATES times;
       when we update it, we have to run the GTK+ main loop to get it
       to repaint what's pending, and doing so may involve an "ioctl()"
       to see if there's any pending input from an X server, and doing
       that for every packet can be costly, especially on a big file. */
    if (count >= progbar_nextstep) {
      /* let's not divide by zero. I should never be started
       * with count == 0, so let's assert that
       */
      g_assert(cf->count > 0);

      prog_val = (gfloat) count / cf->count;

      if (progbar == NULL)
        /* Create the progress bar if necessary */
        progbar = delayed_create_progress_dlg("Changing", "time display", 
          &stop_flag, &start_time, prog_val);

      if (progbar != NULL) {
        g_snprintf(status_str, sizeof(status_str),
                   "%4u of %u packets", count, cf->count);
        update_progress_dlg(progbar, prog_val, status_str);
      }

      progbar_nextstep += progbar_quantum;
    }

    if (stop_flag) {
      /* Well, the user decided to abort the redisplay.  Just stop.

         XXX - this leaves the time field in the old format in
         frames we haven't yet processed.  So it goes; should we
         simply not offer them the option of stopping? */
      break;
    }

    count++;

    /* Find what row this packet is in. */
    if (!sorted_by_frame_column) {
      /* This function is O(N), so we try to avoid using it... */
      row = packet_list_find_row_from_data(fdata);
    } else {
      /* ...which we do by maintaining a count of packets that are
         being displayed (i.e., that have passed the display filter),
         and using the current value of that count as the row number
         (which is why we can only do it when the display is sorted
         by the frame number). */
      if (fdata->flags.passed_dfilter)
        row++;
      else
        continue;
    }

    if (row != -1) {
      /* This packet is in the summary list, on row "row". */

      for (i = first; i <= last; i++) {
        if (cf->cinfo.fmt_matx[i][COL_CLS_TIME]) {
          /* This is one of the columns that shows the time in
             "command-line-specified" format; update it. */
          cf->cinfo.col_buf[i][0] = '\0';
          col_set_cls_time(fdata, &cf->cinfo, i);
          packet_list_set_text(row, i, cf->cinfo.col_data[i]);
        }
      }
    }
  }

  /* We're done redisplaying the packets; destroy the progress bar if it
     was created. */
  if (progbar != NULL)
    destroy_progress_dlg(progbar);

  /* Set the column widths of those columns that show the time in
     "command-line-specified" format. */
  for (i = first; i <= last; i++) {
    if (cf->cinfo.fmt_matx[i][COL_CLS_TIME]) {
      packet_list_set_cls_time_width(i);
    }
  }

  /* Unfreeze the packet list. */
  packet_list_thaw();
}

typedef struct {
        const char      *string;
        size_t          string_len;
        capture_file    *cf;
        gboolean        frame_matched;
} match_data;

gboolean
find_packet_protocol_tree(capture_file *cf, const char *string)
{
  match_data            mdata;

  mdata.string = string;
  mdata.string_len = strlen(string);
  return find_packet(cf, match_protocol_tree, &mdata);
}

static gboolean
match_protocol_tree(capture_file *cf, frame_data *fdata, void *criterion)
{
  match_data            *mdata = criterion;
  epan_dissect_t        *edt;

  /* Construct the protocol tree, including the displayed text */
  edt = epan_dissect_new(TRUE, TRUE);
  /* We don't need the column information */
  epan_dissect_run(edt, &cf->pseudo_header, cf->pd, fdata, NULL);

  /* Iterate through all the nodes, seeing if they have text that matches. */
  mdata->cf = cf;
  mdata->frame_matched = FALSE;
  proto_tree_children_foreach(edt->tree, match_subtree_text, mdata);
  epan_dissect_free(edt);
  return mdata->frame_matched;
}

static void
match_subtree_text(proto_node *node, gpointer data)
{
  match_data    *mdata = (match_data*) data;
  const gchar   *string = mdata->string;
  size_t        string_len = mdata->string_len;
  capture_file  *cf = mdata->cf;
  field_info    *fi = PITEM_FINFO(node);
  gchar         label_str[ITEM_LABEL_LENGTH];
  gchar         *label_ptr;
  size_t        label_len;
  guint32       i;
  guint8        c_char;
  size_t        c_match = 0;

  if (mdata->frame_matched) {
    /* We already had a match; don't bother doing any more work. */
    return;
  }

  /* Don't match invisible entries. */
  if (PROTO_ITEM_IS_HIDDEN(node))
    return;

  /* was a free format label produced? */
  if (fi->rep) {
    label_ptr = fi->rep->representation;
  } else {
    /* no, make a generic label */
    label_ptr = label_str;
    proto_item_fill_label(fi, label_str);
  }
    
  /* Does that label match? */
  label_len = strlen(label_ptr);
  for (i = 0; i < label_len; i++) {
    c_char = label_ptr[i];
    if (cf->case_type)
      c_char = toupper(c_char);
    if (c_char == string[c_match]) {
      c_match++;
      if (c_match == string_len) {
        /* No need to look further; we have a match */
        mdata->frame_matched = TRUE;
        return;
      }
    } else
      c_match = 0;
  }
  
  /* Recurse into the subtree, if it exists */
  if (node->first_child != NULL)
    proto_tree_children_foreach(node, match_subtree_text, mdata);
}

gboolean
find_packet_summary_line(capture_file *cf, const char *string)
{
  match_data            mdata;

  mdata.string = string;
  mdata.string_len = strlen(string);
  return find_packet(cf, match_summary_line, &mdata);
}

static gboolean
match_summary_line(capture_file *cf, frame_data *fdata, void *criterion)
{
  match_data            *mdata = criterion;
  const gchar           *string = mdata->string;
  size_t                string_len = mdata->string_len;
  epan_dissect_t        *edt;
  const char            *info_column;
  size_t                info_column_len;
  gboolean              frame_matched = FALSE;
  gint                  colx;
  guint32               i;
  guint8                c_char;
  size_t                c_match = 0;

  /* Don't bother constructing the protocol tree */
  edt = epan_dissect_new(FALSE, FALSE);
  /* Get the column information */
  epan_dissect_run(edt, &cf->pseudo_header, cf->pd, fdata, &cf->cinfo);

  /* Find the Info column */
  for (colx = 0; colx < cf->cinfo.num_cols; colx++) {
    if (cf->cinfo.fmt_matx[colx][COL_INFO]) {
      /* Found it.  See if we match. */
      info_column = edt->pi.cinfo->col_data[colx];
      info_column_len = strlen(info_column);
      for (i = 0; i < info_column_len; i++) {
        c_char = info_column[i];
        if (cf->case_type)
          c_char = toupper(c_char);
        if (c_char == string[c_match]) {
          c_match++;
          if (c_match == string_len) {
            frame_matched = TRUE;
            break;
          }
        } else
          c_match = 0;
      }
      break;
    }
  }
  epan_dissect_free(edt);
  return frame_matched;
}

typedef struct {
        const guint8 *data;
        size_t data_len;
} cbs_t;        /* "Counted byte string" */

gboolean
find_packet_data(capture_file *cf, const guint8 *string, size_t string_size)
{
  cbs_t info;

  info.data = string;
  info.data_len = string_size;

  /* String or hex search? */
  if (cf->string) {
    /* String search - what type of string? */
    switch (cf->scs_type) {

    case SCS_ASCII_AND_UNICODE:
      return find_packet(cf, match_ascii_and_unicode, &info);

    case SCS_ASCII:
      return find_packet(cf, match_ascii, &info);

    case SCS_UNICODE:
      return find_packet(cf, match_unicode, &info);

    default:
      g_assert_not_reached();
      return FALSE;
    }
  } else
    return find_packet(cf, match_binary, &info);
}

static gboolean
match_ascii_and_unicode(capture_file *cf, frame_data *fdata, void *criterion)
{
  cbs_t         *info = criterion;
  const char    *ascii_text = info->data;
  size_t        textlen = info->data_len;
  gboolean      frame_matched;
  guint32       buf_len;
  guint32       i;
  guint8        c_char;
  size_t        c_match = 0;

  frame_matched = FALSE;
  buf_len = fdata->pkt_len;
  for (i = 0; i < buf_len; i++) {
    c_char = cf->pd[i];
    if (cf->case_type)
      c_char = toupper(c_char);
    if (c_char != 0) {
      if (c_char == ascii_text[c_match]) {
        c_match++;
        if (c_match == textlen) {
          frame_matched = TRUE;
          break;
        }
      } else
        c_match = 0;
    }
  }
  return frame_matched;
}

static gboolean
match_ascii(capture_file *cf, frame_data *fdata, void *criterion)
{
  cbs_t         *info = criterion;
  const char    *ascii_text = info->data;
  size_t        textlen = info->data_len;
  gboolean      frame_matched;
  guint32       buf_len;
  guint32       i;
  guint8        c_char;
  size_t        c_match = 0;

  frame_matched = FALSE;
  buf_len = fdata->pkt_len;
  for (i = 0; i < buf_len; i++) {
    c_char = cf->pd[i];
    if (cf->case_type)
      c_char = toupper(c_char);
    if (c_char == ascii_text[c_match]) {
      c_match++;
      if (c_match == textlen) {
        frame_matched = TRUE;
        break;
      }
    } else
      c_match = 0;
  }
  return frame_matched;
}

static gboolean
match_unicode(capture_file *cf, frame_data *fdata, void *criterion)
{
  cbs_t         *info = criterion;
  const char    *ascii_text = info->data;
  size_t        textlen = info->data_len;
  gboolean      frame_matched;
  guint32       buf_len;
  guint32       i;
  guint8        c_char;
  size_t        c_match = 0;

  frame_matched = FALSE;
  buf_len = fdata->pkt_len;
  for (i = 0; i < buf_len; i++) {
    c_char = cf->pd[i];
    if (cf->case_type)
      c_char = toupper(c_char);
    if (c_char == ascii_text[c_match]) {
      c_match++;
      i++;
      if (c_match == textlen) {
        frame_matched = TRUE;
        break;
      }
    } else
      c_match = 0;
  }
  return frame_matched;
}

static gboolean
match_binary(capture_file *cf, frame_data *fdata, void *criterion)
{
  cbs_t         *info = criterion;
  const guint8  *binary_data = info->data;
  size_t        datalen = info->data_len;
  gboolean      frame_matched;
  guint32       buf_len;
  guint32       i;
  size_t        c_match = 0;

  frame_matched = FALSE;
  buf_len = fdata->pkt_len;
  for (i = 0; i < buf_len; i++) {
    if (cf->pd[i] == binary_data[c_match]) {
      c_match++;
      if (c_match == datalen) {
        frame_matched = TRUE;
        break;
      }
    } else
      c_match = 0;
  }
  return frame_matched;
}

gboolean
find_packet_dfilter(capture_file *cf, dfilter_t *sfcode)
{
  return find_packet(cf, match_dfilter, sfcode);
}

static gboolean
match_dfilter(capture_file *cf, frame_data *fdata, void *criterion)
{
  dfilter_t             *sfcode = criterion;
  epan_dissect_t        *edt;
  gboolean              frame_matched;

  edt = epan_dissect_new(TRUE, FALSE);
  epan_dissect_prime_dfilter(edt, sfcode);
  epan_dissect_run(edt, &cf->pseudo_header, cf->pd, fdata, NULL);
  frame_matched = dfilter_apply_edt(sfcode, edt);
  epan_dissect_free(edt);
  return frame_matched;
}

static gboolean
find_packet(capture_file *cf,
            gboolean (*match_function)(capture_file *, frame_data *, void *),
            void *criterion)
{
  frame_data *start_fd;
  frame_data *fdata;
  frame_data *new_fd = NULL;
  progdlg_t  *progbar = NULL;
  gboolean    stop_flag;
  int         count;
  int         err;
  gchar      *err_info;
  int         row;
  float       prog_val;
  GTimeVal    start_time;
  gchar       status_str[100];
  int         progbar_nextstep;
  int         progbar_quantum;

  start_fd = cf->current_frame;
  if (start_fd != NULL)  {
    /* Iterate through the list of packets, starting at the packet we've
       picked, calling a routine to run the filter on the packet, see if
       it matches, and stop if so.  */
    count = 0;
    fdata = start_fd;

    progbar_nextstep = 0;
    /* When we reach the value that triggers a progress bar update,
       bump that value by this amount. */
    progbar_quantum = cf->count/N_PROGBAR_UPDATES;

    stop_flag = FALSE;
    g_get_current_time(&start_time);

    fdata = start_fd;
    for (;;) {
      /* Update the progress bar, but do it only N_PROGBAR_UPDATES times;
         when we update it, we have to run the GTK+ main loop to get it
         to repaint what's pending, and doing so may involve an "ioctl()"
         to see if there's any pending input from an X server, and doing
         that for every packet can be costly, especially on a big file. */
      if (count >= progbar_nextstep) {
        /* let's not divide by zero. I should never be started
         * with count == 0, so let's assert that
         */
        g_assert(cf->count > 0);

        prog_val = (gfloat) count / cf->count;

        /* Create the progress bar if necessary */
        if (progbar == NULL)
           progbar = delayed_create_progress_dlg("Searching", cf->sfilter, 
             &stop_flag, &start_time, prog_val);

        if (progbar != NULL) {
          g_snprintf(status_str, sizeof(status_str),
                     "%4u of %u packets", count, cf->count);
          update_progress_dlg(progbar, prog_val, status_str);
        }

        progbar_nextstep += progbar_quantum;
      }

      if (stop_flag) {
        /* Well, the user decided to abort the search.  Go back to the
           frame where we started. */
        new_fd = start_fd;
        break;
      }

      /* Go past the current frame. */
      if (cf->sbackward) {
        /* Go on to the previous frame. */
        fdata = fdata->prev;
        if (fdata == NULL) {
          /*
           * XXX - other apps have a bit more of a detailed message
           * for this, and instead of offering "OK" and "Cancel",
           * they offer things such as "Continue" and "Cancel";
           * we need an API for popping up alert boxes with
           * {Verb} and "Cancel".
           */
          simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
                        "%sBeginning of capture exceeded!%s\n\n"
                        "Search is continued from the end of the capture.",
                        simple_dialog_primary_start(), simple_dialog_primary_end());
          fdata = cf->plist_end;        /* wrap around */
        }
      } else {
        /* Go on to the next frame. */
        fdata = fdata->next;
        if (fdata == NULL) {
          simple_dialog(ESD_TYPE_INFO, ESD_BTN_OK,
                        "%sEnd of capture exceeded!%s\n\n"
                        "Search is continued from the start of the capture.",
                        simple_dialog_primary_start(), simple_dialog_primary_end());
          fdata = cf->plist;    /* wrap around */
        }
      }

      count++;

      /* Is this packet in the display? */
      if (fdata->flags.passed_dfilter) {
        /* Yes.  Load its data. */
        if (!wtap_seek_read(cf->wth, fdata->file_off, &cf->pseudo_header,
                        cf->pd, fdata->cap_len, &err, &err_info)) {
          /* Read error.  Report the error, and go back to the frame
             where we started. */
          simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                        cf_read_error_message(err, err_info), cf->filename);
          new_fd = start_fd;
          break;
        }

        /* Does it match the search criterion? */
        if ((*match_function)(cf, fdata, criterion)) {
          new_fd = fdata;
          break;        /* found it! */
        }
      }

      if (fdata == start_fd) {
        /* We're back to the frame we were on originally, and that frame
           doesn't match the search filter.  The search failed. */
        break;
      }
    }

    /* We're done scanning the packets; destroy the progress bar if it
       was created. */
    if (progbar != NULL)
      destroy_progress_dlg(progbar);
  }

  if (new_fd != NULL) {
    /* We found a frame.  Find what row it's in. */
    row = packet_list_find_row_from_data(new_fd);
    g_assert(row != -1);

    /* Select that row, make it the focus row, and make it visible. */
    packet_list_set_selected_row(row);
    return TRUE;        /* success */
  } else
    return FALSE;       /* failure */
}

gboolean
goto_frame(capture_file *cf, guint fnumber)
{
  frame_data *fdata;
  int row;

  for (fdata = cf->plist; fdata != NULL && fdata->num < fnumber; fdata = fdata->next)
    ;

  if (fdata == NULL) {
    /* we didn't find a packet with that packet number */
    simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                  "There is no packet with that packet number.");
    return FALSE;       /* we failed to go to that packet */
  }
  if (!fdata->flags.passed_dfilter) {
    /* that packet currently isn't displayed */
    /* XXX - add it to the set of displayed packets? */
    simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                  "That packet is not currently being displayed.");
    return FALSE;       /* we failed to go to that packet */
  }

  /* We found that packet, and it's currently being displayed.
     Find what row it's in. */
  row = packet_list_find_row_from_data(fdata);
  g_assert(row != -1);

  /* Select that row, make it the focus row, and make it visible. */
  packet_list_set_selected_row(row);
  return TRUE;  /* we got to that packet */
}

gboolean
goto_top_frame(capture_file *cf)
{
  frame_data *fdata;
  int row;
  frame_data *lowest_fdata = NULL;

  for (fdata = cf->plist; fdata != NULL; fdata = fdata->next) {
    if (fdata->flags.passed_dfilter) {
        lowest_fdata = fdata;
        break;
    }
  }

  if (lowest_fdata == NULL) {
      return FALSE;
  }

  /* We found that packet, and it's currently being displayed.
     Find what row it's in. */
  row = packet_list_find_row_from_data(lowest_fdata);
  g_assert(row != -1);

  /* Select that row, make it the focus row, and make it visible. */
  packet_list_set_selected_row(row);
  return TRUE;  /* we got to that packet */
}

gboolean
goto_bottom_frame(capture_file *cf)
{
  frame_data *fdata;
  int row;
  frame_data *highest_fdata = NULL;

  for (fdata = cf->plist; fdata != NULL; fdata = fdata->next) {
    if (fdata->flags.passed_dfilter) {
        highest_fdata = fdata;
    }
  }

  if (highest_fdata == NULL) {
      return FALSE;
  }

  /* We found that packet, and it's currently being displayed.
     Find what row it's in. */
  row = packet_list_find_row_from_data(highest_fdata);
  g_assert(row != -1);

  /* Select that row, make it the focus row, and make it visible. */
  packet_list_set_selected_row(row);
  return TRUE;  /* we got to that packet */
}

/* Select the packet on a given row. */
void
select_packet(capture_file *cf, int row)
{
  frame_data *fdata;
  int err;
  gchar *err_info;

  /* Get the frame data struct pointer for this frame */
  fdata = (frame_data *)packet_list_get_row_data(row);

  if (fdata == NULL) {
    /* XXX - if a GtkCList's selection mode is GTK_SELECTION_BROWSE, when
       the first entry is added to it by "real_insert_row()", that row
       is selected (see "real_insert_row()", in "gtk/gtkclist.c", in both
       our version and the vanilla GTK+ version).

       This means that a "select-row" signal is emitted; this causes
       "packet_list_select_cb()" to be called, which causes "select_packet()"
       to be called.

       "select_packet()" fetches, above, the data associated with the
       row that was selected; however, as "gtk_clist_append()", which
       called "real_insert_row()", hasn't yet returned, we haven't yet
       associated any data with that row, so we get back a null pointer.

       We can't assume that there's only one frame in the frame list,
       either, as we may be filtering the display.

       We therefore assume that, if "row" is 0, i.e. the first row
       is being selected, and "cf->first_displayed" equals
       "cf->last_displayed", i.e. there's only one frame being
       displayed, that frame is the frame we want.

       This means we have to set "cf->first_displayed" and
       "cf->last_displayed" before adding the row to the
       GtkCList; see the comment in "add_packet_to_packet_list()". */

       if (row == 0 && cf->first_displayed == cf->last_displayed)
         fdata = cf->first_displayed;
  }

  /* Get the data in that frame. */
  if (!wtap_seek_read (cf->wth, fdata->file_off, &cf->pseudo_header,
                       cf->pd, fdata->cap_len, &err, &err_info)) {
    simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                  cf_read_error_message(err, err_info), cf->filename);
    return;
  }

  /* Record that this frame is the current frame. */
  cf->current_frame = fdata;

  /* Create the logical protocol tree. */
  if (cf->edt != NULL) {
    epan_dissect_free(cf->edt);
    cf->edt = NULL;
  }
  /* We don't need the columns here. */
  cf->edt = epan_dissect_new(TRUE, TRUE);
  epan_dissect_run(cf->edt, &cf->pseudo_header, cf->pd, cf->current_frame,
          NULL);

  /* Display the GUI protocol tree and hex dump.
     XXX - why do we dump core if we call "proto_tree_draw()"
     before calling "add_byte_views()"? */
  add_main_byte_views(cf->edt);
  main_proto_tree_draw(cf->edt->tree);

  /* A packet is selected. */
  set_menus_for_selected_packet(cf);
}

/* Unselect the selected packet, if any. */
void
unselect_packet(capture_file *cf)
{
  /* Destroy the epan_dissect_t for the unselected packet. */
  if (cf->edt != NULL) {
    epan_dissect_free(cf->edt);
    cf->edt = NULL;
  }

  /* Clear out the display of that packet. */
  clear_tree_and_hex_views();

  /* No packet is selected. */
  cf->current_frame = NULL;
  set_menus_for_selected_packet(cf);

  /* No protocol tree means no selected field. */
  unselect_field(cf);
}

/* Unset the selected protocol tree field, if any. */
void
unselect_field(capture_file *cf)
{
  statusbar_pop_field_msg();
  cf->finfo_selected = NULL;
  set_menus_for_selected_tree_row(cf);
}

/*
 * Mark a particular frame.
 */
void
mark_frame(capture_file *cf, frame_data *frame)
{
  frame->flags.marked = TRUE;
  cf->marked_count++;
}

/*
 * Unmark a particular frame.
 */
void
unmark_frame(capture_file *cf, frame_data *frame)
{
  frame->flags.marked = FALSE;
  cf->marked_count--;
}

typedef struct {
  wtap_dumper *pdh;
  const char  *fname;
} save_callback_args_t;

/*
 * Save a capture to a file, in a particular format, saving either
 * all packets, all currently-displayed packets, or all marked packets.
 *
 * Returns TRUE if it succeeds, FALSE otherwise; if it fails, it pops
 * up a message box for the failure.
 */
static gboolean
save_packet(capture_file *cf _U_, frame_data *fdata,
            union wtap_pseudo_header *pseudo_header, const guint8 *pd,
            void *argsp)
{
  save_callback_args_t *args = argsp;
  struct wtap_pkthdr hdr;
  int           err;

  /* init the wtap header for saving */
  hdr.ts.tv_sec  = fdata->abs_secs;
  hdr.ts.tv_usec = fdata->abs_usecs;
  hdr.caplen     = fdata->cap_len;
  hdr.len        = fdata->pkt_len;
  hdr.pkt_encap  = fdata->lnk_t;

  /* and save the packet */
  if (!wtap_dump(args->pdh, &hdr, pseudo_header, pd, &err)) {
    cf_write_failure_alert_box(args->fname, err);
    return FALSE;
  }
  return TRUE;
}

gboolean
cf_save(char *fname, capture_file *cf, packet_range_t *range, guint save_format)
{
  gchar        *from_filename;
  gchar        *name_ptr, *save_msg, *save_fmt = " Saving: %s...";
  size_t        msg_len;
  int           err;
  gboolean      do_copy;
  wtap_dumper  *pdh;
  struct stat   infile, outfile;
  save_callback_args_t callback_args;

  name_ptr = get_basename(fname);
  msg_len = strlen(name_ptr) + strlen(save_fmt) + 2;
  save_msg = g_malloc(msg_len);
  snprintf(save_msg, msg_len, save_fmt, name_ptr);
  statusbar_push_file_msg(save_msg);
  g_free(save_msg);

  /*
   * Check that the from file is not the same as to file
   * We do it here so we catch all cases ...
   * Unfortunately, the file requester gives us an absolute file
   * name and the read file name may be relative (if supplied on
   * the command line). From Joerg Mayer.
   *
   * This is a bit tricky on win32. The st_ino field is documented as:
   * "The inode, and therefore st_ino, has no meaning in the FAT, ..."
   * but it *is* set to zero if stat() returns without an error,
   * so this is working, but maybe not quite the way expected. ULFL
   */
   infile.st_ino = 1;   /* These prevent us from getting equality         */
   outfile.st_ino = 2;  /* If one or other of the files is not accessible */
   stat(cf->filename, &infile);
   stat(fname, &outfile);
   if (infile.st_ino == outfile.st_ino) {
    simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
      "%sCapture file: \"%s\" already exists!%s\n\n"
      "Please choose a different filename.",
      simple_dialog_primary_start(), fname, simple_dialog_primary_end());
    goto fail;
  }

  packet_range_process_init(range);

  /* Used to be :
   * if (!save_filtered && !save_marked && !save_manual_range && 
   *     !save_marked_range && !save_curr && save_format == cf->cd_t) {
   */ 
        
  if (packet_range_process_all(range) && save_format == cf->cd_t) {
    /* We're not filtering packets, and we're saving it in the format
       it's already in, so we can just move or copy the raw data. */

    if (cf->is_tempfile) {
      /* The file being saved is a temporary file from a live
         capture, so it doesn't need to stay around under that name;
         first, try renaming the capture buffer file to the new name. */
#ifndef WIN32
      if (rename(cf->filename, fname) == 0) {
        /* That succeeded - there's no need to copy the source file. */
        from_filename = NULL;
        do_copy = FALSE;
      } else {
        if (errno == EXDEV) {
          /* They're on different file systems, so we have to copy the
             file. */
          do_copy = TRUE;
          from_filename = cf->filename;
        } else {
          /* The rename failed, but not because they're on different
             file systems - put up an error message.  (Or should we
             just punt and try to copy?  The only reason why I'd
             expect the rename to fail and the copy to succeed would
             be if we didn't have permission to remove the file from
             the temporary directory, and that might be fixable - but
             is it worth requiring the user to go off and fix it?) */
          simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                                file_rename_error_message(errno), fname);
          goto fail;
        }
      }
#else
      do_copy = TRUE;
      from_filename = cf->filename;
#endif
    } else {
      /* It's a permanent file, so we should copy it, and not remove the
         original. */
      do_copy = TRUE;
      from_filename = cf->filename;
    }

    if (do_copy) {
      /* Copy the file, if we haven't moved it. */
      if (!copy_binary_file(from_filename, fname))
        goto fail;
    }
  } else {
    /* Either we're filtering packets, or we're saving in a different
       format; we can't do that by copying or moving the capture file,
       we have to do it by writing the packets out in Wiretap. */
    pdh = wtap_dump_open(fname, save_format, cf->lnk_t, cf->snap, &err);
    if (pdh == NULL) {
      cf_open_failure_alert_box(fname, err, NULL, TRUE, save_format);
      goto fail;
    }

    /* XXX - we let the user save a subset of the packets.

       If we do that, should we make that file the current file?  If so,
       it means we can no longer get at the other packets.  What does
       NetMon do? */

    /* Iterate through the list of packets, processing the packets we were
       told to process.

       XXX - we've already called "packet_range_process_init(range)", but
       "process_specified_packets()" will do it again.  Fortunately,
       that's harmless in this case, as we haven't done anything to
       "range" since we initialized it. */
    callback_args.pdh = pdh;
    callback_args.fname = fname;
    switch (process_specified_packets(cf, range, "Saving",
                                      "selected packets", save_packet,
                                      &callback_args)) {

    case PSP_FINISHED:
      /* Completed successfully. */
      break;

    case PSP_STOPPED:
      /* The user decided to abort the saving.
         XXX - remove the output file? */
      break;

    case PSP_FAILED:
      /* Error while saving. */
      wtap_dump_close(pdh, &err);
      goto fail;
    }

    if (!wtap_dump_close(pdh, &err)) {
      cf_close_failure_alert_box(fname, err);
      goto fail;
    }
  }

  /* Pop the "Saving:" message off the status bar. */
  statusbar_pop_file_msg();

  if (packet_range_process_all(range)) {
    /* We saved the entire capture, not just some packets from it.
       Open and read the file we saved it to.

       XXX - this is somewhat of a waste; we already have the
       packets, all this gets us is updated file type information
       (which we could just stuff into "cf"), and having the new
       file be the one we have opened and from which we're reading
       the data, and it means we have to spend time opening and
       reading the file, which could be a significant amount of
       time if the file is large. */
    cf->user_saved = TRUE;

    if ((err = cf_open(fname, FALSE, cf)) == 0) {
      /* XXX - report errors if this fails?
         What should we return if it fails or is aborted? */
      switch (cf_read(cf)) {

      case READ_SUCCESS:
      case READ_ERROR:
        /* Just because we got an error, that doesn't mean we were unable
           to read any of the file; we handle what we could get from the
           file. */
        break;

      case READ_ABORTED:
        /* The user bailed out of re-reading the capture file; the
           capture file has been closed - just return (without
           changing any menu settings; "cf_close()" set them
           correctly for the "no capture file open" state). */
        break;
      }
      set_menus_for_unsaved_capture_file(FALSE);
    }
  }
  return TRUE;

fail:
  /* Pop the "Saving:" message off the status bar. */
  statusbar_pop_file_msg();
  return FALSE;
}

static void
cf_open_failure_alert_box(const char *filename, int err, gchar *err_info,
                          gboolean for_writing, int file_type)
{
  if (err < 0) {
    /* Wiretap error. */
    switch (err) {

    case WTAP_ERR_NOT_REGULAR_FILE:
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" is a \"special file\" or socket or other non-regular file.",
                    filename);
      break;

    case WTAP_ERR_RANDOM_OPEN_PIPE:
      /* Seen only when opening a capture file for reading. */
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" is a pipe or FIFO; Ethereal cannot read pipe or FIFO files.",
                    filename);
      break;

    case WTAP_ERR_FILE_UNKNOWN_FORMAT:
      /* Seen only when opening a capture file for reading. */
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" is not a capture file in a format Ethereal understands.",
                    filename);
      break;

    case WTAP_ERR_UNSUPPORTED:
      /* Seen only when opening a capture file for reading. */
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" is not a capture file in a format Ethereal understands.\n"
                    "(%s)",
                    filename, err_info);
      g_free(err_info);
      break;

    case WTAP_ERR_CANT_WRITE_TO_PIPE:
      /* Seen only when opening a capture file for writing. */
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" is a pipe, and %s capture files cannot be "
                    "written to a pipe.",
                    filename, wtap_file_type_string(file_type));
      break;

    case WTAP_ERR_UNSUPPORTED_FILE_TYPE:
      /* Seen only when opening a capture file for writing. */
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "Ethereal does not support writing capture files in that format.");
      break;

    case WTAP_ERR_UNSUPPORTED_ENCAP:
      if (for_writing) {
        simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                      "Ethereal cannot save this capture in that format.");
      } else {
        simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                      "The file \"%s\" is a capture for a network type that Ethereal doesn't support.\n"
                      "(%s)",
                      filename, err_info);
        g_free(err_info);
      }
      break;

    case WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED:
      if (for_writing) {
        simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                      "Ethereal cannot save this capture in that format.");
      } else {
        simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                      "The file \"%s\" is a capture for a network type that Ethereal doesn't support.",
                      filename);
      }
      break;

    case WTAP_ERR_BAD_RECORD:
      /* Seen only when opening a capture file for reading. */
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" appears to be damaged or corrupt.\n"
                    "(%s)",
                    filename, err_info);
      g_free(err_info);
      break;

    case WTAP_ERR_CANT_OPEN:
      if (for_writing) {
        simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                      "The file \"%s\" could not be created for some unknown reason.",
                      filename);
      } else {
        simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                      "The file \"%s\" could not be opened for some unknown reason.",
                      filename);
      }
      break;

    case WTAP_ERR_SHORT_READ:
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" appears to have been cut short"
                    " in the middle of a packet or other data.",
                    filename);
      break;

    case WTAP_ERR_SHORT_WRITE:
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "A full header couldn't be written to the file \"%s\".",
                    filename);
      break;

    default:
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" could not be %s: %s.",
                    filename,
                    for_writing ? "created" : "opened",
                    wtap_strerror(err));
      break;
    }
  } else {
    /* OS error. */
    open_failure_alert_box(filename, err, for_writing);
  }
}

static char *
file_rename_error_message(int err)
{
  char *errmsg;
  static char errmsg_errno[1024+1];

  switch (err) {

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

  case EACCES:
    errmsg = "You do not have permission to move the capture file to \"%s\".";
    break;

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

char *
cf_read_error_message(int err, gchar *err_info)
{
  static char errmsg_errno[1024+1];

  switch (err) {

  case WTAP_ERR_UNSUPPORTED:
  case WTAP_ERR_UNSUPPORTED_ENCAP:
  case WTAP_ERR_BAD_RECORD:
    snprintf(errmsg_errno, sizeof(errmsg_errno),
             "An error occurred while reading from the file \"%%s\": %s.\n(%s)",
             wtap_strerror(err), err_info);
    break;

  default:
    snprintf(errmsg_errno, sizeof(errmsg_errno),
             "An error occurred while reading from the file \"%%s\": %s.",
             wtap_strerror(err));
    break;
  }
  return errmsg_errno;
}

static void
cf_write_failure_alert_box(const char *filename, int err)
{
  if (err < 0) {
    /* Wiretap error. */
    simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                  "An error occurred while writing to the file \"%s\": %s.",
                  filename, wtap_strerror(err));
  } else {
    /* OS error. */
    write_failure_alert_box(filename, err);
  }
}

/* Check for write errors - if the file is being written to an NFS server,
   a write error may not show up until the file is closed, as NFS clients
   might not send writes to the server until the "write()" call finishes,
   so that the write may fail on the server but the "write()" may succeed. */
static void
cf_close_failure_alert_box(const char *filename, int err)
{
  if (err < 0) {
    /* Wiretap error. */
    switch (err) {

    case WTAP_ERR_CANT_CLOSE:
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "The file \"%s\" couldn't be closed for some unknown reason.",
                    filename);
      break;

    case WTAP_ERR_SHORT_WRITE:
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "Not all the packets could be written to the file \"%s\".",
                    filename);
      break;

    default:
      simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                    "An error occurred while closing the file \"%s\": %s.",
                    filename, wtap_strerror(err));
      break;
    }
  } else {
    /* OS error.
       We assume that a close error from the OS is really a write error. */
    write_failure_alert_box(filename, err);
  }
}


/* Copies a file in binary mode, for those operating systems that care about
 * such things.
 * Returns TRUE on success, FALSE on failure. If a failure, it also
 * displays a simple dialog window with the error message.
 */
static gboolean
copy_binary_file(char *from_filename, char *to_filename)
{
  int           from_fd, to_fd, nread, nwritten, err;
  guint8        pd[65536];

  /* Copy the raw bytes of the file. */
  from_fd = open(from_filename, O_RDONLY | O_BINARY);
  if (from_fd < 0) {
    open_failure_alert_box(from_filename, errno, FALSE);
    goto done;
  }

  /* Use open() instead of creat() so that we can pass the O_BINARY
     flag, which is relevant on Win32; it appears that "creat()"
     may open the file in text mode, not binary mode, but we want
     to copy the raw bytes of the file, so we need the output file
     to be open in binary mode. */
  to_fd = open(to_filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
  if (to_fd < 0) {
    open_failure_alert_box(to_filename, errno, TRUE);
    close(from_fd);
    goto done;
  }

  while ((nread = read(from_fd, pd, sizeof pd)) > 0) {
    nwritten = write(to_fd, pd, nread);
    if (nwritten < nread) {
      if (nwritten < 0)
        err = errno;
      else
        err = WTAP_ERR_SHORT_WRITE;
      write_failure_alert_box(to_filename, err);
      close(from_fd);
      close(to_fd);
      goto done;
    }
  }
  if (nread < 0) {
    err = errno;
    simple_dialog(ESD_TYPE_ERROR, ESD_BTN_OK,
                  "An error occurred while reading from the file \"%s\": %s.",
                  from_filename, strerror(err));
    close(from_fd);
    close(to_fd);
    goto done;
  }
  close(from_fd);
  if (close(to_fd) < 0) {
    write_failure_alert_box(to_filename, errno);
    goto done;
  }

  return TRUE;

done:
  return FALSE;
}