/* capture_sync.h
 * Synchronisation between Ethereal capture parent and child instances
 *
 * $Id$
 *
 * 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.
 */


/** @file
 *  
 *  Sync mode capture (internal interface).
 *
 *  Will start a new Ethereal child instance which will do the actual capture 
 *  work.
 */

#ifndef __CAPTURE_SYNC_H__
#define __CAPTURE_SYNC_H__


/*
 * Maximum length of sync pipe message data.  Must be < 2^24, as the
 * message length is 3 bytes.
 * XXX - this must be large enough to handle a Really Big Filter
 * Expression, as the error message for an incorrect filter expression
 * is a bit larger than the filter expression.
 */
#define SP_MAX_MSG_LEN	4096


/* Size of buffer to hold decimal representation of
   signed/unsigned 64-bit int */
#define SP_DECISIZE 20

/*
 * Indications sent out on the sync pipe (from child to parent).
 */
#define SP_FILE         'F'     /* the name of the recently opened file */
#define SP_ERROR_MSG    'E'     /* error message */
#define SP_BAD_FILTER   'B'     /* error message for bad capture filter */
#define SP_PACKET_COUNT 'P'     /* count of packets captured since last message */
#define SP_DROPS        'D'     /* count of packets dropped in capture */
/*
 * Win32 only: Indications sent out on the signal pipe (from parent to child)
 * (UNIX-like sends signals for this)
 */
#define SP_QUIT         'Q'     /* "gracefully" capture quit message (SIGUSR1) */



/** 
 * Start a new capture session.
 *  Create a capture child which is doing the real capture work.
 *  The various capture_input_... functions will be called, if something had 
 *  happened.
 *
 *  Most of the parameters are passed through the global capture_opts.
 *
 *  @param capture_opts the options
 *  @return             TRUE if a capture could be started, FALSE if not
 */
extern gboolean 
sync_pipe_start(capture_options *capture_opts);

/** User wants to stop capturing, gracefully close the capture child */
extern void
sync_pipe_stop(capture_options *capture_opts);

/** User wants to stop the program, just kill the child as soon as possible */
extern void
sync_pipe_kill(capture_options *capture_opts);


/** the child has opened a new capture file, notify the parent */
extern void
sync_pipe_filename_to_parent(const char *filename);

/** the child captured some new packets, notify the parent */
extern void
sync_pipe_packet_count_to_parent(int packet_count);

/** the child stopped capturing, notify the parent */
extern void
sync_pipe_drops_to_parent(int drops);

/** the child encountered an error with a capture filter, notify the parent */
extern void
sync_pipe_cfilter_error_to_parent(const char *cfilter, const char *errmsg);

/** the child encountered an error, notify the parent */
extern void 
sync_pipe_errmsg_to_parent(const char *error_msg,
                           const char *secondary_error_msg);


/** does the parent signalled the child to stop */
#ifdef _WIN32
extern gboolean
signal_pipe_check_running(void);
#endif

#endif /* capture_sync.h */