/*	$OpenBSD: adjacency.c,v 1.27 2019/12/12 00:10:29 yasuoka Exp $ */

/*
 * Copyright (c) 2013, 2015 Renato Westphal <renato@openbsd.org>
 * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
 * Copyright (c) 2004, 2005, 2008 Esben Norby <norby@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <string.h>

#include "ldpd.h"
#include "ldpe.h"
#include "log.h"

static void	 adj_del_single(struct adj *);
static void	 adj_itimer(int, short, void *);
static void	 tnbr_del(struct tnbr *);
static void	 tnbr_hello_timer(int, short, void *);
static void	 tnbr_start_hello_timer(struct tnbr *);
static void	 tnbr_stop_hello_timer(struct tnbr *);

struct adj *
adj_new(struct in_addr lsr_id, struct hello_source *source,
    union ldpd_addr *addr)
{
	struct adj	*adj;

	log_debug("%s: lsr-id %s, %s", __func__, inet_ntoa(lsr_id),
	    log_hello_src(source));

	if ((adj = calloc(1, sizeof(*adj))) == NULL)
		fatal(__func__);

	adj->lsr_id = lsr_id;
	adj->nbr = NULL;
	adj->source = *source;
	adj->trans_addr = *addr;

	evtimer_set(&adj->inactivity_timer, adj_itimer, adj);

	LIST_INSERT_HEAD(&global.adj_list, adj, global_entry);

	switch (source->type) {
	case HELLO_LINK:
		LIST_INSERT_HEAD(&source->link.ia->adj_list, adj, ia_entry);
		break;
	case HELLO_TARGETED:
		source->target->adj = adj;
		break;
	}

	return (adj);
}

static void
adj_del_single(struct adj *adj)
{
	log_debug("%s: lsr-id %s, %s (%s)", __func__, inet_ntoa(adj->lsr_id),
	    log_hello_src(&adj->source), af_name(adj_get_af(adj)));

	adj_stop_itimer(adj);

	LIST_REMOVE(adj, global_entry);
	if (adj->nbr)
		LIST_REMOVE(adj, nbr_entry);
	switch (adj->source.type) {
	case HELLO_LINK:
		LIST_REMOVE(adj, ia_entry);
		break;
	case HELLO_TARGETED:
		adj->source.target->adj = NULL;
		break;
	}

	free(adj);
}

void
adj_del(struct adj *adj, uint32_t notif_status)
{
	struct nbr	*nbr = adj->nbr;
	struct adj	*atmp;

	adj_del_single(adj);

	/*
	 * If the neighbor still exists but none of its remaining
	 * adjacencies (if any) are from the preferred address-family,
	 * then delete it.
	 */
	if (nbr && nbr_adj_count(nbr, nbr->af) == 0) {
		LIST_FOREACH_SAFE(adj, &nbr->adj_list, nbr_entry, atmp)
			adj_del_single(adj);
		session_shutdown(nbr, notif_status, 0, 0);
		nbr_del(nbr);
	}
}

struct adj *
adj_find(struct hello_source *source)
{
	struct adj *adj;

	LIST_FOREACH(adj, &global.adj_list, global_entry) {
		if (adj->source.type != source->type)
			continue;

		if (adj->lsr_id.s_addr != source->lsr_id.s_addr)
			continue;

		switch (source->type) {
		case HELLO_LINK:
			if (ldp_addrcmp(source->link.ia->af,
			    &adj->source.link.src_addr,
			    &source->link.src_addr) == 0)
				return (adj);
			break;
		case HELLO_TARGETED:
			if (adj->source.target == source->target)
				return (adj);
			break;
		}
	}

	return (NULL);
}

int
adj_get_af(struct adj *adj)
{
	switch (adj->source.type) {
	case HELLO_LINK:
		return (adj->source.link.ia->af);
	case HELLO_TARGETED:
		return (adj->source.target->af);
	default:
		fatalx("adj_get_af: unknown hello type");
	}
}

/* adjacency timers */

/* ARGSUSED */
static void
adj_itimer(int fd, short event, void *arg)
{
	struct adj *adj = arg;

	log_debug("%s: lsr-id %s", __func__, inet_ntoa(adj->lsr_id));

	if (adj->source.type == HELLO_TARGETED) {
		if (!(adj->source.target->flags & F_TNBR_CONFIGURED) &&
		    adj->source.target->pw_count == 0) {
			/* remove dynamic targeted neighbor */
			tnbr_del(adj->source.target);
			return;
		}
		adj->source.target->adj = NULL;
	}

	adj_del(adj, S_HOLDTIME_EXP);
}

void
adj_start_itimer(struct adj *adj)
{
	struct timeval	tv;

	timerclear(&tv);
	tv.tv_sec = adj->holdtime;
	if (evtimer_add(&adj->inactivity_timer, &tv) == -1)
		fatal(__func__);
}

void
adj_stop_itimer(struct adj *adj)
{
	if (evtimer_pending(&adj->inactivity_timer, NULL) &&
	    evtimer_del(&adj->inactivity_timer) == -1)
		fatal(__func__);
}

/* targeted neighbors */

struct tnbr *
tnbr_new(struct ldpd_conf *xconf, int af, union ldpd_addr *addr)
{
	struct tnbr		*tnbr;

	if ((tnbr = calloc(1, sizeof(*tnbr))) == NULL)
		fatal(__func__);

	tnbr->af = af;
	tnbr->addr = *addr;
	tnbr->state = TNBR_STA_DOWN;
	tnbr->hello_holdtime = (ldp_af_conf_get(xconf, af))->thello_holdtime;
	tnbr->hello_interval = (ldp_af_conf_get(xconf, af))->thello_interval;

	return (tnbr);
}

static void
tnbr_del(struct tnbr *tnbr)
{
	tnbr_stop_hello_timer(tnbr);
	if (tnbr->adj)
		adj_del(tnbr->adj, S_SHUTDOWN);
	LIST_REMOVE(tnbr, entry);
	free(tnbr);
}

struct tnbr *
tnbr_find(struct ldpd_conf *xconf, int af, union ldpd_addr *addr)
{
	struct tnbr *tnbr;

	LIST_FOREACH(tnbr, &xconf->tnbr_list, entry)
		if (af == tnbr->af &&
		    ldp_addrcmp(af, addr, &tnbr->addr) == 0)
			return (tnbr);

	return (NULL);
}

struct tnbr *
tnbr_check(struct tnbr *tnbr)
{
	if (!(tnbr->flags & (F_TNBR_CONFIGURED|F_TNBR_DYNAMIC)) &&
	    tnbr->pw_count == 0) {
		tnbr_del(tnbr);
		return (NULL);
	}

	return (tnbr);
}

void
tnbr_update(struct tnbr *tnbr)
{
	int			 socket_ok, rtr_id_ok;

	if ((ldp_af_global_get(&global, tnbr->af))->ldp_edisc_socket != -1)
		socket_ok = 1;
	else
		socket_ok = 0;

	if (leconf->rtr_id.s_addr != INADDR_ANY)
		rtr_id_ok = 1;
	else
		rtr_id_ok = 0;

	if (tnbr->state == TNBR_STA_DOWN) {
		if (!socket_ok || !rtr_id_ok)
			return;

		tnbr->state = TNBR_STA_ACTIVE;
		send_hello(HELLO_TARGETED, NULL, tnbr);

		evtimer_set(&tnbr->hello_timer, tnbr_hello_timer, tnbr);
		tnbr_start_hello_timer(tnbr);
	} else if (tnbr->state == TNBR_STA_ACTIVE) {
		if (socket_ok && rtr_id_ok)
			return;

		tnbr->state = TNBR_STA_DOWN;
		tnbr_stop_hello_timer(tnbr);
	}
}

void
tnbr_update_all(int af)
{
	struct tnbr		*tnbr;

	/* update targeted neighbors */
	LIST_FOREACH(tnbr, &leconf->tnbr_list, entry)
		if (tnbr->af == af || af == AF_UNSPEC)
			tnbr_update(tnbr);
}

/* target neighbors timers */

/* ARGSUSED */
static void
tnbr_hello_timer(int fd, short event, void *arg)
{
	struct tnbr	*tnbr = arg;

	send_hello(HELLO_TARGETED, NULL, tnbr);
	tnbr_start_hello_timer(tnbr);
}

static void
tnbr_start_hello_timer(struct tnbr *tnbr)
{
	struct timeval	 tv;

	timerclear(&tv);
	tv.tv_sec = tnbr->hello_interval;
	if (evtimer_add(&tnbr->hello_timer, &tv) == -1)
		fatal(__func__);
}

static void
tnbr_stop_hello_timer(struct tnbr *tnbr)
{
	if (evtimer_pending(&tnbr->hello_timer, NULL) &&
	    evtimer_del(&tnbr->hello_timer) == -1)
		fatal(__func__);
}

struct ctl_adj *
adj_to_ctl(struct adj *adj)
{
	static struct ctl_adj	 actl;

	actl.af = adj_get_af(adj);
	actl.id = adj->lsr_id;
	actl.type = adj->source.type;
	switch (adj->source.type) {
	case HELLO_LINK:
		memcpy(actl.ifname, adj->source.link.ia->iface->name,
		    sizeof(actl.ifname));
		break;
	case HELLO_TARGETED:
		actl.src_addr = adj->source.target->addr;
		break;
	}
	actl.holdtime = adj->holdtime;
	actl.trans_addr = adj->trans_addr;

	return (&actl);
}