/**

 * @file tc.h

 * @brief Provides Transparent Clock logic.

 * @note Copyright (C) 2018 Richard Cochran <richardcochran@gmail.com>

 *

 * 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.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA.

 */

#ifndef HAVE_TC_H

#define HAVE_TC_H

#include "msg.h"

#include "port_private.h"

/**

 * Flushes the list of remembered residence times.

 * @param q    Port whose list should be flushed

 */

void tc_flush(struct port *q);

/**

 * Forwards a given general message out all other ports.

 * @param q    The ingress port

 * @param msg  The message to be sent

 * @return     Zero on success, non-zero otherwise.

 */

int tc_forward(struct port *q, struct ptp_message *msg);

/**

 * Forwards a given Follow-Up message out all other ports.

 *

 * This function adds the unique, per egress port residence time into

 * the correction field for the transmitted follow up message.

 *

 * @param q    The ingress port

 * @param msg  The message to be sent

 * @return     Zero on success, non-zero otherwise.

 */

int tc_fwd_folup(struct port *q, struct ptp_message *msg);

/**

 * Forwards a given delay request message out all other ports.

 *

 * This function computes the unique residence time for each egress

 * port, remembering it in that egress port.

 *

 * @param q    The ingress port

 * @param msg  The message to be sent

 * @return     Zero on success, non-zero otherwise.

 */

int tc_fwd_request(struct port *q, struct ptp_message *msg);

/**

 * Forwards a given response message out all other ports.

 *

 * This function adds the unique, per egress port residence time into

 * the correction field for the transmitted delay response message.

 *

 * @param q    The ingress port

 * @param msg  The message to be sent

 * @return     Zero on success, non-zero otherwise.

 */

int tc_fwd_response(struct port *q, struct ptp_message *msg);

/**

 * Forwards a given sync message out all other ports.

 *

 * This function computes the unique residence time for each egress

 * port, remembering it in that egress port.

 *

 * @param q    The ingress port

 * @param msg  The message to be sent

 * @return     Zero on success, non-zero otherwise.

 */

int tc_fwd_sync(struct port *q, struct ptp_message *msg);

/**

 * Determines whether the local clock should ignore a given message.

 *

 * @param q    The ingress port

 * @param msg  The message to test

 * @return     One if the message should be ignored, zero otherwise.

 */

int tc_ignore(struct port *q, struct ptp_message *m);

/**

 * Prunes stale entries from the list of remembered residence times.

 * @param q    Port whose list should be pruned.

 */

void tc_prune(struct port *q);

#endif