/**

 * @file p2p_tc.c

 * @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.

 */

#include <errno.h>

#include "port.h"

#include "port_private.h"

#include "print.h"

#include "rtnl.h"

#include "tc.h"

static int p2p_delay_request(struct port *p)

{

	switch (p->state) {

	case PS_INITIALIZING:

	case PS_FAULTY:

	case PS_DISABLED:

		return 0;

	case PS_LISTENING:

	case PS_PRE_MASTER:

	case PS_MASTER:

	case PS_PASSIVE:

	case PS_UNCALIBRATED:

	case PS_SLAVE:

	case PS_GRAND_MASTER:

		break;

	}

	return port_delay_request(p);

}

void p2p_dispatch(struct port *p, enum fsm_event event, int mdiff)

{

	if (!port_state_update(p, event, mdiff)) {

		return;

	}

	if (!portnum(p)) {

		/* UDS needs no timers. */

		return;

	}

	port_clr_tmo(p->fda.fd[FD_ANNOUNCE_TIMER]);

	port_clr_tmo(p->fda.fd[FD_SYNC_RX_TIMER]);

	/* Leave FD_DELAY_TIMER running. */

	port_clr_tmo(p->fda.fd[FD_QUALIFICATION_TIMER]);

	port_clr_tmo(p->fda.fd[FD_MANNO_TIMER]);

	port_clr_tmo(p->fda.fd[FD_SYNC_TX_TIMER]);

	/*

	 * Handle the side effects of the state transition.

	 */

	switch (p->state) {

	case PS_INITIALIZING:

		break;

	case PS_FAULTY:

	case PS_DISABLED:

		port_disable(p);

		break;

	case PS_LISTENING:

		port_set_announce_tmo(p);

		port_set_delay_tmo(p);

		break;

	case PS_PRE_MASTER:

		port_set_qualification_tmo(p);

		break;

	case PS_MASTER:

	case PS_GRAND_MASTER:

		break;

	case PS_PASSIVE:

		port_set_announce_tmo(p);

		break;

	case PS_UNCALIBRATED:

	case PS_SLAVE:

		port_set_announce_tmo(p);

		break;

	};

}

enum fsm_event p2p_event(struct port *p, int fd_index)

{

	int cnt, fd = p->fda.fd[fd_index];

	enum fsm_event event = EV_NONE;

	struct ptp_message *msg, *dup;

	switch (fd_index) {

	case FD_ANNOUNCE_TIMER:

	case FD_SYNC_RX_TIMER:

		pr_debug("port %hu: %s timeout", portnum(p),

			 fd_index == FD_SYNC_RX_TIMER ? "rx sync" : "announce");

		if (p->best) {

			fc_clear(p->best);

		}

		port_set_announce_tmo(p);

		return EV_ANNOUNCE_RECEIPT_TIMEOUT_EXPIRES;

	case FD_DELAY_TIMER:

		pr_debug("port %hu: delay timeout", portnum(p));

		port_set_delay_tmo(p);

		tc_prune(p);

		return p2p_delay_request(p) ? EV_FAULT_DETECTED : EV_NONE;

	case FD_QUALIFICATION_TIMER:

		pr_debug("port %hu: qualification timeout", portnum(p));

		return EV_QUALIFICATION_TIMEOUT_EXPIRES;

	case FD_MANNO_TIMER:

	case FD_SYNC_TX_TIMER:

	case FD_UNICAST_REQ_TIMER:

	case FD_UNICAST_SRV_TIMER:

		pr_err("unexpected timer expiration");

		return EV_NONE;

	case FD_RTNL:

		pr_debug("port %hu: received link status notification", portnum(p));

		rtnl_link_status(fd, p->name, port_link_status, p);

		if (p->link_status == (LINK_UP|LINK_STATE_CHANGED)) {

			return EV_FAULT_CLEARED;

		} else if ((p->link_status == (LINK_DOWN|LINK_STATE_CHANGED)) ||

			   (p->link_status & TS_LABEL_CHANGED)) {

			return EV_FAULT_DETECTED;

		} else {

			return EV_NONE;

		}

	}

	msg = msg_allocate();

	if (!msg) {

		return EV_FAULT_DETECTED;

	}

	msg->hwts.type = p->timestamping;

	cnt = transport_recv(p->trp, fd, msg);

	if (cnt <= 0) {

		pr_err("port %hu: recv message failed", portnum(p));

		msg_put(msg);

		return EV_FAULT_DETECTED;

	}

	if (msg_sots_valid(msg)) {

		ts_add(&msg->hwts.ts, -p->rx_timestamp_offset);

	}

	if (msg_unicast(msg)) {

		pl_warning(600, "cannot switch unicast messages!");

		msg_put(msg);

		return EV_NONE;

	}

	dup = msg_duplicate(msg, cnt);

	if (!dup) {

		msg_put(msg);

		return EV_NONE;

	}

	if (tc_ignore(p, dup)) {

		msg_put(dup);

		dup = NULL;

	}

	switch (msg_type(msg)) {

	case SYNC:

		if (tc_fwd_sync(p, msg)) {

			event = EV_FAULT_DETECTED;

			break;

		}

		if (dup) {

			process_sync(p, dup);

		}

		break;

	case DELAY_REQ:

		break;

	case PDELAY_REQ:

		if (dup && process_pdelay_req(p, dup)) {

			event = EV_FAULT_DETECTED;

		}

		break;

	case PDELAY_RESP:

		if (dup && process_pdelay_resp(p, dup)) {

			event = EV_FAULT_DETECTED;

		}

		break;

	case FOLLOW_UP:

		if (tc_fwd_folup(p, msg)) {

			event = EV_FAULT_DETECTED;

			break;

		}

		if (dup) {

			process_follow_up(p, dup);

		}

		break;

	case DELAY_RESP:

		break;

	case PDELAY_RESP_FOLLOW_UP:

		if (dup) {

			process_pdelay_resp_fup(p, dup);

		}

		break;

	case ANNOUNCE:

		if (tc_forward(p, msg)) {

			event = EV_FAULT_DETECTED;

			break;

		}

		if (dup && process_announce(p, dup)) {

			event = EV_STATE_DECISION_EVENT;

		}

		break;

	case SIGNALING:

	case MANAGEMENT:

		if (tc_forward(p, msg)) {

			event = EV_FAULT_DETECTED;

		}

		break;

	}

	msg_put(msg);

	if (dup) {

		msg_put(dup);

	}

	return event;

}