/* BGP-4 Finite State Machine
 * From RFC1771 [A Border Gateway Protocol 4 (BGP-4)]
 * Copyright (C) 1998 Kunihiro Ishiguro
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra 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, or (at your option) any
 * later version.
 *
 * GNU Zebra 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; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef _QUAGGA_BGP_FSM_H
#define _QUAGGA_BGP_FSM_H

/* Macro for BGP read, write and timer thread.  */
#define BGP_TIMER_ON(T, F, V)                                                  \
	do {                                                                   \
		if ((peer->status != Deleted))                                 \
			thread_add_timer(bm->master, (F), peer, (V), &(T));    \
	} while (0)

#define BGP_EVENT_ADD(P, E)                                                    \
	do {                                                                   \
		if ((P)->status != Deleted)                                    \
			thread_add_event(bm->master, bgp_event, (P), (E),      \
					 NULL);                                \
	} while (0)

#define BGP_EVENT_FLUSH(P)                                                     \
	do {                                                                   \
		assert(peer);                                                  \
		thread_cancel_event_ready(bm->master, (P));                    \
	} while (0)

#define BGP_UPDATE_GROUP_TIMER_ON(T, F)					       \
	do {								       \
		if (BGP_SUPPRESS_FIB_ENABLED(peer->bgp) &&		       \
		    PEER_ROUTE_ADV_DELAY(peer))				       \
			thread_add_timer_msec(bm->master, (F), peer,	       \
				(BGP_DEFAULT_UPDATE_ADVERTISEMENT_TIME * 1000),\
				(T));					       \
		else							       \
			thread_add_timer_msec(bm->master, (F), peer,	       \
					      0, (T));			       \
	} while (0)							       \

#define BGP_MSEC_JITTER 10

/* Status codes for bgp_event_update() */
#define FSM_PEER_NOOP           0
#define FSM_PEER_STOPPED        1
#define FSM_PEER_TRANSFERRED    2
#define FSM_PEER_TRANSITIONED   3

#define BGP_PEER_GR_HELPER_ENABLE(peer)	\
	do {		\
		UNSET_FLAG( \
			peer->peer_gr_new_status_flag,		\
			PEER_GRACEFUL_RESTART_NEW_STATE_RESTART);	\
		SET_FLAG( \
			peer->peer_gr_new_status_flag,	\
			PEER_GRACEFUL_RESTART_NEW_STATE_HELPER);\
	} while (0)

#define BGP_PEER_GR_ENABLE(peer)\
	do {				\
		SET_FLAG(   \
			peer->peer_gr_new_status_flag,	\
			PEER_GRACEFUL_RESTART_NEW_STATE_RESTART); \
		UNSET_FLAG( \
			peer->peer_gr_new_status_flag,	\
			PEER_GRACEFUL_RESTART_NEW_STATE_HELPER);\
	} while (0)

#define BGP_PEER_GR_DISABLE(peer)\
	do {				\
		UNSET_FLAG( \
			peer->peer_gr_new_status_flag,	\
			PEER_GRACEFUL_RESTART_NEW_STATE_RESTART);\
		UNSET_FLAG(\
			peer->peer_gr_new_status_flag, \
			PEER_GRACEFUL_RESTART_NEW_STATE_HELPER);\
	} while (0)

#define BGP_PEER_GR_GLOBAL_INHERIT_SET(peer) \
			SET_FLAG(peer->peer_gr_new_status_flag,	\
				PEER_GRACEFUL_RESTART_NEW_STATE_INHERIT)

#define BGP_PEER_GR_GLOBAL_INHERIT_UNSET(peer)	\
			UNSET_FLAG(peer->peer_gr_new_status_flag, \
				PEER_GRACEFUL_RESTART_NEW_STATE_INHERIT)

#define BGP_PEER_GRACEFUL_RESTART_CAPABLE(peer)                                \
	(CHECK_FLAG(peer->cap, PEER_CAP_RESTART_ADV)                           \
	 && CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV))

#define BGP_PEER_RESTARTING_MODE(peer)                                         \
	(CHECK_FLAG(peer->flags, PEER_FLAG_GRACEFUL_RESTART) &&                \
	 CHECK_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_ADV) &&         \
	 !CHECK_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_RCV))

#define BGP_PEER_HELPER_MODE(peer)                                             \
	(CHECK_FLAG(peer->flags, PEER_FLAG_GRACEFUL_RESTART_HELPER) &&         \
	 CHECK_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_RCV) &&         \
	 !CHECK_FLAG(peer->cap, PEER_CAP_GRACEFUL_RESTART_R_BIT_ADV))

/* Prototypes. */

/*
 * Update FSM for peer based on whether we have valid nexthops or not.
 */
extern void bgp_fsm_nht_update(struct peer *peer, bool has_valid_nexthops);
extern void bgp_event(struct thread *);
extern int bgp_event_update(struct peer *, enum bgp_fsm_events event);
extern int bgp_stop(struct peer *peer);
extern void bgp_timer_set(struct peer *);
extern void bgp_routeadv_timer(struct thread *);
extern void bgp_fsm_change_status(struct peer *peer, int status);
extern const char *const peer_down_str[];
extern void bgp_update_delay_end(struct bgp *);
extern void bgp_maxmed_update(struct bgp *);
extern bool bgp_maxmed_onstartup_configured(struct bgp *);
extern bool bgp_maxmed_onstartup_active(struct bgp *);
extern int bgp_fsm_error_subcode(int status);

/**
 * Start the route advertisement timer (that honors MRAI) for all the
 * peers. Typically called at the end of initial convergence, coming
 * out of read-only mode.
 */
extern void bgp_start_routeadv(struct bgp *);

/**
 * See if the route advertisement timer needs to be adjusted for a
 * peer. For example, if the last update was written to the peer a
 * long while back, we don't need to wait for the periodic advertisement
 * timer to expire to send the new set of prefixes. It should fire
 * instantly and updates should go out sooner.
 */
extern void bgp_adjust_routeadv(struct peer *);

#include "hook.h"
DECLARE_HOOK(peer_backward_transition, (struct peer *peer), (peer));
DECLARE_HOOK(peer_established, (struct peer *peer), (peer));

int bgp_gr_update_all(struct bgp *bgp, int global_gr_cmd);
int bgp_neighbor_graceful_restart(struct peer *peer, int peer_gr_cmd);
unsigned int bgp_peer_gr_action(struct peer *peer,
		int old_peer_state, int new_peer_state);
void bgp_peer_move_to_gr_mode(struct peer *peer, int new_state);
unsigned int bgp_peer_gr_helper_enable(struct peer *peer);
unsigned int bgp_peer_gr_enable(struct peer *peer);
unsigned int bgp_peer_gr_global_inherit(struct peer *peer);
unsigned int bgp_peer_gr_disable(struct peer *peer);
enum peer_mode bgp_peer_gr_mode_get(struct peer *peer);
enum global_mode bgp_global_gr_mode_get(struct bgp *bgp);
enum peer_mode bgp_get_peer_gr_mode_from_flags(struct peer *peer);
unsigned int bgp_peer_gr_global_inherit_unset(struct peer *peer);
int bgp_gr_lookup_n_update_all_peer(struct bgp *bgp,
		enum global_mode global_new_state,
		enum global_mode global_old_state);
void bgp_peer_gr_flags_update(struct peer *peer);
const char *print_peer_gr_mode(enum peer_mode pr_mode);
const char *print_peer_gr_cmd(enum peer_gr_command pr_gr_cmd);
const char *print_global_gr_mode(enum global_mode gl_mode);
const char *print_global_gr_cmd(enum global_gr_command gl_gr_cmd);
int bgp_peer_reg_with_nht(struct peer *peer);
#endif /* _QUAGGA_BGP_FSM_H */
