/*
 * Copyright (C) 2003 Yasuhiro Ohara
 *
 * 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
 */

#include <zebra.h>

#include "log.h"
#include "memory.h"
#include "vty.h"
#include "linklist.h"
#include "prefix.h"
#include "table.h"
#include "thread.h"
#include "command.h"
#include "defaults.h"

#include "ospf6_proto.h"
#include "ospf6_message.h"
#include "ospf6_lsa.h"
#include "ospf6_lsdb.h"
#include "ospf6_route.h"
#include "ospf6_zebra.h"

#include "ospf6_top.h"
#include "ospf6_area.h"
#include "ospf6_interface.h"
#include "ospf6_neighbor.h"

#include "ospf6_flood.h"
#include "ospf6_asbr.h"
#include "ospf6_abr.h"
#include "ospf6_intra.h"
#include "ospf6_spf.h"
#include "ospf6d.h"

DEFINE_QOBJ_TYPE(ospf6)

FRR_CFG_DEFAULT_BOOL(OSPF6_LOG_ADJACENCY_CHANGES,
	{ .val_bool = true, .match_profile = "datacenter", },
	{ .val_bool = false },
)

/* global ospf6d variable */
struct ospf6 *ospf6;
static struct ospf6_master ospf6_master;
struct ospf6_master *om6;

static void ospf6_disable(struct ospf6 *o);

static void ospf6_top_lsdb_hook_add(struct ospf6_lsa *lsa)
{
	switch (ntohs(lsa->header->type)) {
	case OSPF6_LSTYPE_AS_EXTERNAL:
		ospf6_asbr_lsa_add(lsa);
		break;

	default:
		break;
	}
}

static void ospf6_top_lsdb_hook_remove(struct ospf6_lsa *lsa)
{
	switch (ntohs(lsa->header->type)) {
	case OSPF6_LSTYPE_AS_EXTERNAL:
		ospf6_asbr_lsa_remove(lsa, NULL);
		break;

	default:
		break;
	}
}

static void ospf6_top_route_hook_add(struct ospf6_route *route)
{
	ospf6_abr_originate_summary(route);
	ospf6_zebra_route_update_add(route);
}

static void ospf6_top_route_hook_remove(struct ospf6_route *route)
{
	route->flag |= OSPF6_ROUTE_REMOVE;
	ospf6_abr_originate_summary(route);
	ospf6_zebra_route_update_remove(route);
}

static void ospf6_top_brouter_hook_add(struct ospf6_route *route)
{
	if (IS_OSPF6_DEBUG_EXAMIN(AS_EXTERNAL) ||
	    IS_OSPF6_DEBUG_BROUTER) {
		uint32_t brouter_id;
		char brouter_name[16];

		brouter_id = ADV_ROUTER_IN_PREFIX(&route->prefix);
		inet_ntop(AF_INET, &brouter_id, brouter_name,
			  sizeof(brouter_name));
		zlog_debug("%s: brouter %s add with adv router %x nh count %u",
			   __func__, brouter_name,
			   route->path.origin.adv_router,
			   listcount(route->nh_list));
	}
	ospf6_abr_examin_brouter(ADV_ROUTER_IN_PREFIX(&route->prefix));
	ospf6_asbr_lsentry_add(route);
	ospf6_abr_originate_summary(route);
}

static void ospf6_top_brouter_hook_remove(struct ospf6_route *route)
{
	if (IS_OSPF6_DEBUG_EXAMIN(AS_EXTERNAL) ||
	    IS_OSPF6_DEBUG_BROUTER) {
		uint32_t brouter_id;
		char brouter_name[16];

		brouter_id = ADV_ROUTER_IN_PREFIX(&route->prefix);
		inet_ntop(AF_INET, &brouter_id, brouter_name,
			  sizeof(brouter_name));
		zlog_debug("%s: brouter %p %s del with adv router %x nh %u",
			   __func__, (void *)route, brouter_name,
			   route->path.origin.adv_router,
			   listcount(route->nh_list));
	}
	route->flag |= OSPF6_ROUTE_REMOVE;
	ospf6_abr_examin_brouter(ADV_ROUTER_IN_PREFIX(&route->prefix));
	ospf6_asbr_lsentry_remove(route);
	ospf6_abr_originate_summary(route);
}

static struct ospf6 *ospf6_create(vrf_id_t vrf_id)
{
	struct ospf6 *o;

	o = XCALLOC(MTYPE_OSPF6_TOP, sizeof(struct ospf6));

	/* initialize */
	monotime(&o->starttime);
	o->vrf_id = vrf_id;
	o->area_list = list_new();
	o->area_list->cmp = ospf6_area_cmp;
	o->lsdb = ospf6_lsdb_create(o);
	o->lsdb_self = ospf6_lsdb_create(o);
	o->lsdb->hook_add = ospf6_top_lsdb_hook_add;
	o->lsdb->hook_remove = ospf6_top_lsdb_hook_remove;

	o->spf_delay = OSPF_SPF_DELAY_DEFAULT;
	o->spf_holdtime = OSPF_SPF_HOLDTIME_DEFAULT;
	o->spf_max_holdtime = OSPF_SPF_MAX_HOLDTIME_DEFAULT;
	o->spf_hold_multiplier = 1;

	/* LSA timers value init */
	o->lsa_minarrival = OSPF_MIN_LS_ARRIVAL;

	o->route_table = OSPF6_ROUTE_TABLE_CREATE(GLOBAL, ROUTES);
	o->route_table->scope = o;
	o->route_table->hook_add = ospf6_top_route_hook_add;
	o->route_table->hook_remove = ospf6_top_route_hook_remove;

	o->brouter_table = OSPF6_ROUTE_TABLE_CREATE(GLOBAL, BORDER_ROUTERS);
	o->brouter_table->scope = o;
	o->brouter_table->hook_add = ospf6_top_brouter_hook_add;
	o->brouter_table->hook_remove = ospf6_top_brouter_hook_remove;

	o->external_table = OSPF6_ROUTE_TABLE_CREATE(GLOBAL, EXTERNAL_ROUTES);
	o->external_table->scope = o;

	o->external_id_table = route_table_init();

	o->ref_bandwidth = OSPF6_REFERENCE_BANDWIDTH;

	o->distance_table = route_table_init();

	QOBJ_REG(o, ospf6);

	return o;
}

void ospf6_delete(struct ospf6 *o)
{
	struct listnode *node, *nnode;
	struct ospf6_area *oa;

	QOBJ_UNREG(o);

	ospf6_flush_self_originated_lsas_now();
	ospf6_disable(ospf6);

	for (ALL_LIST_ELEMENTS(o->area_list, node, nnode, oa))
		ospf6_area_delete(oa);


	list_delete(&o->area_list);

	ospf6_lsdb_delete(o->lsdb);
	ospf6_lsdb_delete(o->lsdb_self);

	ospf6_route_table_delete(o->route_table);
	ospf6_route_table_delete(o->brouter_table);

	ospf6_route_table_delete(o->external_table);
	route_table_finish(o->external_id_table);

	ospf6_distance_reset(o);
	route_table_finish(o->distance_table);

	XFREE(MTYPE_OSPF6_TOP, o);
}

static void ospf6_disable(struct ospf6 *o)
{
	struct listnode *node, *nnode;
	struct ospf6_area *oa;

	if (!CHECK_FLAG(o->flag, OSPF6_DISABLED)) {
		SET_FLAG(o->flag, OSPF6_DISABLED);

		for (ALL_LIST_ELEMENTS(o->area_list, node, nnode, oa))
			ospf6_area_disable(oa);

		/* XXX: This also changes persistent settings */
		ospf6_asbr_redistribute_reset();

		ospf6_lsdb_remove_all(o->lsdb);
		ospf6_route_remove_all(o->route_table);
		ospf6_route_remove_all(o->brouter_table);

		THREAD_OFF(o->maxage_remover);
		THREAD_OFF(o->t_spf_calc);
		THREAD_OFF(o->t_ase_calc);
		THREAD_OFF(o->t_distribute_update);
	}
}

void ospf6_master_init(void)
{
	memset(&ospf6_master, 0, sizeof(struct ospf6_master));

	om6 = &ospf6_master;
}

static int ospf6_maxage_remover(struct thread *thread)
{
	struct ospf6 *o = (struct ospf6 *)THREAD_ARG(thread);
	struct ospf6_area *oa;
	struct ospf6_interface *oi;
	struct ospf6_neighbor *on;
	struct listnode *i, *j, *k;
	int reschedule = 0;

	o->maxage_remover = (struct thread *)NULL;

	for (ALL_LIST_ELEMENTS_RO(o->area_list, i, oa)) {
		for (ALL_LIST_ELEMENTS_RO(oa->if_list, j, oi)) {
			for (ALL_LIST_ELEMENTS_RO(oi->neighbor_list, k, on)) {
				if (on->state != OSPF6_NEIGHBOR_EXCHANGE
				    && on->state != OSPF6_NEIGHBOR_LOADING)
					continue;

				ospf6_maxage_remove(o);
				return 0;
			}
		}
	}

	for (ALL_LIST_ELEMENTS_RO(o->area_list, i, oa)) {
		for (ALL_LIST_ELEMENTS_RO(oa->if_list, j, oi)) {
			if (ospf6_lsdb_maxage_remover(oi->lsdb)) {
				reschedule = 1;
			}
		}

		if (ospf6_lsdb_maxage_remover(oa->lsdb)) {
			reschedule = 1;
		}
	}

	if (ospf6_lsdb_maxage_remover(o->lsdb)) {
		reschedule = 1;
	}

	if (reschedule) {
		ospf6_maxage_remove(o);
	}

	return 0;
}

void ospf6_maxage_remove(struct ospf6 *o)
{
	if (o)
		thread_add_timer(master, ospf6_maxage_remover, o,
				 OSPF_LSA_MAXAGE_REMOVE_DELAY_DEFAULT,
				 &o->maxage_remover);
}

void ospf6_router_id_update(void)
{
	if (!ospf6)
		return;

	if (ospf6->router_id_static != 0)
		ospf6->router_id = ospf6->router_id_static;
	else
		ospf6->router_id = om6->zebra_router_id;
}

/* start ospf6 */
DEFUN_NOSH (router_ospf6,
       router_ospf6_cmd,
       "router ospf6",
       ROUTER_STR
       OSPF6_STR)
{
	if (ospf6 == NULL) {
		ospf6 = ospf6_create(VRF_DEFAULT);
		if (DFLT_OSPF6_LOG_ADJACENCY_CHANGES)
			SET_FLAG(ospf6->config_flags,
				 OSPF6_LOG_ADJACENCY_CHANGES);
		if (ospf6->router_id == 0)
			ospf6_router_id_update();
	}
	/* set current ospf point. */
	VTY_PUSH_CONTEXT(OSPF6_NODE, ospf6);

	return CMD_SUCCESS;
}

/* stop ospf6 */
DEFUN (no_router_ospf6,
       no_router_ospf6_cmd,
       "no router ospf6",
       NO_STR
       ROUTER_STR
       OSPF6_STR)
{
	if (ospf6 == NULL)
		vty_out(vty, "OSPFv3 is not configured\n");
	else {
		ospf6_delete(ospf6);
		ospf6 = NULL;
	}

	/* return to config node . */
	VTY_PUSH_CONTEXT_NULL(CONFIG_NODE);

	return CMD_SUCCESS;
}

/* change Router_ID commands. */
DEFUN(ospf6_router_id,
      ospf6_router_id_cmd,
      "ospf6 router-id A.B.C.D",
      OSPF6_STR
      "Configure OSPF6 Router-ID\n"
      V4NOTATION_STR)
{
	VTY_DECLVAR_CONTEXT(ospf6, o);
	int idx = 0;
	int ret;
	const char *router_id_str;
	uint32_t router_id;
	struct ospf6_area *oa;
	struct listnode *node;

	argv_find(argv, argc, "A.B.C.D", &idx);
	router_id_str = argv[idx]->arg;

	ret = inet_pton(AF_INET, router_id_str, &router_id);
	if (ret == 0) {
		vty_out(vty, "malformed OSPF Router-ID: %s\n", router_id_str);
		return CMD_SUCCESS;
	}

	o->router_id_static = router_id;

	for (ALL_LIST_ELEMENTS_RO(o->area_list, node, oa)) {
		if (oa->full_nbrs) {
			vty_out(vty,
				"For this router-id change to take effect,"
				" save config and restart ospf6d\n");
			return CMD_SUCCESS;
		}
	}

	o->router_id = router_id;

	return CMD_SUCCESS;
}

DEFUN(no_ospf6_router_id,
      no_ospf6_router_id_cmd,
      "no ospf6 router-id [A.B.C.D]",
      NO_STR OSPF6_STR
      "Configure OSPF6 Router-ID\n"
      V4NOTATION_STR)
{
	VTY_DECLVAR_CONTEXT(ospf6, o);
	struct ospf6_area *oa;
	struct listnode *node;

	o->router_id_static = 0;

	for (ALL_LIST_ELEMENTS_RO(o->area_list, node, oa)) {
		if (oa->full_nbrs) {
			vty_out(vty,
				"For this router-id change to take effect,"
				" save config and restart ospf6d\n");
			return CMD_SUCCESS;
		}
	}
	o->router_id = 0;
	if (o->router_id_zebra.s_addr)
		o->router_id = (uint32_t)o->router_id_zebra.s_addr;

	return CMD_SUCCESS;
}

DEFUN (ospf6_log_adjacency_changes,
       ospf6_log_adjacency_changes_cmd,
       "log-adjacency-changes",
       "Log changes in adjacency state\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, ospf6);

	SET_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_CHANGES);
	UNSET_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_DETAIL);
	return CMD_SUCCESS;
}

DEFUN (ospf6_log_adjacency_changes_detail,
       ospf6_log_adjacency_changes_detail_cmd,
       "log-adjacency-changes detail",
       "Log changes in adjacency state\n"
       "Log all state changes\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, ospf6);

	SET_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_CHANGES);
	SET_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_DETAIL);
	return CMD_SUCCESS;
}

DEFUN (no_ospf6_log_adjacency_changes,
       no_ospf6_log_adjacency_changes_cmd,
       "no log-adjacency-changes",
       NO_STR
       "Log changes in adjacency state\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, ospf6);

	UNSET_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_DETAIL);
	UNSET_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_CHANGES);
	return CMD_SUCCESS;
}

DEFUN (no_ospf6_log_adjacency_changes_detail,
       no_ospf6_log_adjacency_changes_detail_cmd,
       "no log-adjacency-changes detail",
       NO_STR
       "Log changes in adjacency state\n"
       "Log all state changes\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, ospf6);

	UNSET_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_DETAIL);
	return CMD_SUCCESS;
}

DEFUN (ospf6_timers_lsa,
       ospf6_timers_lsa_cmd,
       "timers lsa min-arrival (0-600000)",
       "Adjust routing timers\n"
       "OSPF6 LSA timers\n"
       "Minimum delay in receiving new version of a LSA\n"
       "Delay in milliseconds\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, ospf);
	int idx_number = 3;
	unsigned int minarrival;

	minarrival = strtoul(argv[idx_number]->arg, NULL, 10);
	ospf->lsa_minarrival = minarrival;

	return CMD_SUCCESS;
}

DEFUN (no_ospf6_timers_lsa,
       no_ospf6_timers_lsa_cmd,
       "no timers lsa min-arrival [(0-600000)]",
       NO_STR
       "Adjust routing timers\n"
       "OSPF6 LSA timers\n"
       "Minimum delay in receiving new version of a LSA\n"
       "Delay in milliseconds\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, ospf);
	int idx_number = 4;
	unsigned int minarrival;

	if (argc == 5) {
		minarrival = strtoul(argv[idx_number]->arg, NULL, 10);

		if (ospf->lsa_minarrival != minarrival
		    || minarrival == OSPF_MIN_LS_ARRIVAL)
			return CMD_SUCCESS;
	}

	ospf->lsa_minarrival = OSPF_MIN_LS_ARRIVAL;

	return CMD_SUCCESS;
}


DEFUN (ospf6_distance,
       ospf6_distance_cmd,
       "distance (1-255)",
       "Administrative distance\n"
       "OSPF6 Administrative distance\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, o);

	o->distance_all = atoi(argv[1]->arg);

	return CMD_SUCCESS;
}

DEFUN (no_ospf6_distance,
       no_ospf6_distance_cmd,
       "no distance (1-255)",
       NO_STR
       "Administrative distance\n"
       "OSPF6 Administrative distance\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, o);

	o->distance_all = 0;

	return CMD_SUCCESS;
}

DEFUN (ospf6_distance_ospf6,
       ospf6_distance_ospf6_cmd,
       "distance ospf6 {intra-area (1-255)|inter-area (1-255)|external (1-255)}",
       "Administrative distance\n"
       "OSPF6 administrative distance\n"
       "Intra-area routes\n"
       "Distance for intra-area routes\n"
       "Inter-area routes\n"
       "Distance for inter-area routes\n"
       "External routes\n"
       "Distance for external routes\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, o);
	int idx = 0;

	o->distance_intra = 0;
	o->distance_inter = 0;
	o->distance_external = 0;

	if (argv_find(argv, argc, "intra-area", &idx))
		o->distance_intra = atoi(argv[idx + 1]->arg);
	idx = 0;
	if (argv_find(argv, argc, "inter-area", &idx))
		o->distance_inter = atoi(argv[idx + 1]->arg);
	idx = 0;
	if (argv_find(argv, argc, "external", &idx))
		o->distance_external = atoi(argv[idx + 1]->arg);

	return CMD_SUCCESS;
}

DEFUN (no_ospf6_distance_ospf6,
       no_ospf6_distance_ospf6_cmd,
       "no distance ospf6 [{intra-area [(1-255)]|inter-area [(1-255)]|external [(1-255)]}]",
       NO_STR
       "Administrative distance\n"
       "OSPF6 distance\n"
       "Intra-area routes\n"
       "Distance for intra-area routes\n"
       "Inter-area routes\n"
       "Distance for inter-area routes\n"
       "External routes\n"
       "Distance for external routes\n")
{
	VTY_DECLVAR_CONTEXT(ospf6, o);
	int idx = 0;

	if (argv_find(argv, argc, "intra-area", &idx) || argc == 3)
		idx = o->distance_intra = 0;
	if (argv_find(argv, argc, "inter-area", &idx) || argc == 3)
		idx = o->distance_inter = 0;
	if (argv_find(argv, argc, "external", &idx) || argc == 3)
		o->distance_external = 0;

	return CMD_SUCCESS;
}

#if 0
DEFUN (ospf6_distance_source,
       ospf6_distance_source_cmd,
       "distance (1-255) X:X::X:X/M [WORD]",
       "Administrative distance\n"
       "Distance value\n"
       "IP source prefix\n"
       "Access list name\n")
{
  VTY_DECLVAR_CONTEXT(ospf6, o);
  char *alname = (argc == 4) ? argv[3]->arg : NULL;
  ospf6_distance_set (vty, o, argv[1]->arg, argv[2]->arg, alname);

  return CMD_SUCCESS;
}

DEFUN (no_ospf6_distance_source,
       no_ospf6_distance_source_cmd,
       "no distance (1-255) X:X::X:X/M [WORD]",
       NO_STR
       "Administrative distance\n"
       "Distance value\n"
       "IP source prefix\n"
       "Access list name\n")
{
  VTY_DECLVAR_CONTEXT(ospf6, o);
  char *alname = (argc == 5) ? argv[4]->arg : NULL;
  ospf6_distance_unset (vty, o, argv[2]->arg, argv[3]->arg, alname);

  return CMD_SUCCESS;
}
#endif

DEFUN (ospf6_interface_area,
       ospf6_interface_area_cmd,
       "interface IFNAME area A.B.C.D",
       "Enable routing on an IPv6 interface\n"
       IFNAME_STR
       "Specify the OSPF6 area ID\n"
       "OSPF6 area ID in IPv4 address notation\n"
      )
{
	VTY_DECLVAR_CONTEXT(ospf6, o);
	int idx_ifname = 1;
	int idx_ipv4 = 3;
	struct ospf6_area *oa;
	struct ospf6_interface *oi;
	struct interface *ifp;
	uint32_t area_id;

	/* find/create ospf6 interface */
	ifp = if_get_by_name(argv[idx_ifname]->arg, VRF_DEFAULT);
	oi = (struct ospf6_interface *)ifp->info;
	if (oi == NULL)
		oi = ospf6_interface_create(ifp);
	if (oi->area) {
		vty_out(vty, "%s already attached to Area %s\n",
			oi->interface->name, oi->area->name);
		return CMD_SUCCESS;
	}

	/* parse Area-ID */
	if (inet_pton(AF_INET, argv[idx_ipv4]->arg, &area_id) != 1) {
		vty_out(vty, "Invalid Area-ID: %s\n", argv[idx_ipv4]->arg);
		return CMD_SUCCESS;
	}

	/* find/create ospf6 area */
	oa = ospf6_area_lookup(area_id, o);
	if (oa == NULL)
		oa = ospf6_area_create(area_id, o, OSPF6_AREA_FMT_DOTTEDQUAD);

	/* attach interface to area */
	listnode_add(oa->if_list, oi); /* sort ?? */
	oi->area = oa;

	SET_FLAG(oa->flag, OSPF6_AREA_ENABLE);

	/* ospf6 process is currently disabled, not much more to do */
	if (CHECK_FLAG(o->flag, OSPF6_DISABLED))
		return CMD_SUCCESS;

	/* start up */
	ospf6_interface_enable(oi);

	/* If the router is ABR, originate summary routes */
	if (ospf6_is_router_abr(o))
		ospf6_abr_enable_area(oa);

	return CMD_SUCCESS;
}

DEFUN (no_ospf6_interface_area,
       no_ospf6_interface_area_cmd,
       "no interface IFNAME area A.B.C.D",
       NO_STR
       "Disable routing on an IPv6 interface\n"
       IFNAME_STR
       "Specify the OSPF6 area ID\n"
       "OSPF6 area ID in IPv4 address notation\n"
       )
{
	int idx_ifname = 2;
	int idx_ipv4 = 4;
	struct ospf6_interface *oi;
	struct ospf6_area *oa;
	struct interface *ifp;
	uint32_t area_id;

	ifp = if_lookup_by_name(argv[idx_ifname]->arg, VRF_DEFAULT);
	if (ifp == NULL) {
		vty_out(vty, "No such interface %s\n", argv[idx_ifname]->arg);
		return CMD_SUCCESS;
	}

	oi = (struct ospf6_interface *)ifp->info;
	if (oi == NULL) {
		vty_out(vty, "Interface %s not enabled\n", ifp->name);
		return CMD_SUCCESS;
	}

	/* parse Area-ID */
	if (inet_pton(AF_INET, argv[idx_ipv4]->arg, &area_id) != 1) {
		vty_out(vty, "Invalid Area-ID: %s\n", argv[idx_ipv4]->arg);
		return CMD_SUCCESS;
	}

	/* Verify Area */
	if (oi->area == NULL) {
		vty_out(vty, "No such Area-ID: %s\n", argv[idx_ipv4]->arg);
		return CMD_SUCCESS;
	}

	if (oi->area->area_id != area_id) {
		vty_out(vty, "Wrong Area-ID: %s is attached to area %s\n",
			oi->interface->name, oi->area->name);
		return CMD_SUCCESS;
	}

	thread_execute(master, interface_down, oi, 0);

	oa = oi->area;
	listnode_delete(oi->area->if_list, oi);
	oi->area = (struct ospf6_area *)NULL;

	/* Withdraw inter-area routes from this area, if necessary */
	if (oa->if_list->count == 0) {
		UNSET_FLAG(oa->flag, OSPF6_AREA_ENABLE);
		ospf6_abr_disable_area(oa);
	}

	return CMD_SUCCESS;
}

DEFUN (ospf6_stub_router_admin,
       ospf6_stub_router_admin_cmd,
       "stub-router administrative",
       "Make router a stub router\n"
       "Administratively applied, for an indefinite period\n")
{
	struct listnode *node;
	struct ospf6_area *oa;

	if (!CHECK_FLAG(ospf6->flag, OSPF6_STUB_ROUTER)) {
		for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, node, oa)) {
			OSPF6_OPT_CLEAR(oa->options, OSPF6_OPT_V6);
			OSPF6_OPT_CLEAR(oa->options, OSPF6_OPT_R);
			OSPF6_ROUTER_LSA_SCHEDULE(oa);
		}
		SET_FLAG(ospf6->flag, OSPF6_STUB_ROUTER);
	}

	return CMD_SUCCESS;
}

DEFUN (no_ospf6_stub_router_admin,
       no_ospf6_stub_router_admin_cmd,
       "no stub-router administrative",
       NO_STR
       "Make router a stub router\n"
       "Administratively applied, for an indefinite period\n")
{
	struct listnode *node;
	struct ospf6_area *oa;

	if (CHECK_FLAG(ospf6->flag, OSPF6_STUB_ROUTER)) {
		for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, node, oa)) {
			OSPF6_OPT_SET(oa->options, OSPF6_OPT_V6);
			OSPF6_OPT_SET(oa->options, OSPF6_OPT_R);
			OSPF6_ROUTER_LSA_SCHEDULE(oa);
		}
		UNSET_FLAG(ospf6->flag, OSPF6_STUB_ROUTER);
	}

	return CMD_SUCCESS;
}

#if 0
DEFUN (ospf6_stub_router_startup,
       ospf6_stub_router_startup_cmd,
       "stub-router on-startup (5-86400)",
       "Make router a stub router\n"
       "Advertise inability to be a transit router\n"
       "Automatically advertise as stub-router on startup of OSPF6\n"
       "Time (seconds) to advertise self as stub-router\n")
{
  return CMD_SUCCESS;
}

DEFUN (no_ospf6_stub_router_startup,
       no_ospf6_stub_router_startup_cmd,
       "no stub-router on-startup",
       NO_STR
       "Make router a stub router\n"
       "Advertise inability to be a transit router\n"
       "Automatically advertise as stub-router on startup of OSPF6\n"
       "Time (seconds) to advertise self as stub-router\n")
{
  return CMD_SUCCESS;
}

DEFUN (ospf6_stub_router_shutdown,
       ospf6_stub_router_shutdown_cmd,
       "stub-router on-shutdown (5-86400)",
       "Make router a stub router\n"
       "Advertise inability to be a transit router\n"
       "Automatically advertise as stub-router before shutdown\n"
       "Time (seconds) to advertise self as stub-router\n")
{
  return CMD_SUCCESS;
}

DEFUN (no_ospf6_stub_router_shutdown,
       no_ospf6_stub_router_shutdown_cmd,
       "no stub-router on-shutdown",
       NO_STR
       "Make router a stub router\n"
       "Advertise inability to be a transit router\n"
       "Automatically advertise as stub-router before shutdown\n"
       "Time (seconds) to advertise self as stub-router\n")
{
  return CMD_SUCCESS;
}
#endif

static void ospf6_show(struct vty *vty, struct ospf6 *o)
{
	struct listnode *n;
	struct ospf6_area *oa;
	char router_id[16], duration[32];
	struct timeval now, running, result;
	char buf[32], rbuf[32];

	/* process id, router id */
	inet_ntop(AF_INET, &o->router_id, router_id, sizeof(router_id));
	vty_out(vty, " OSPFv3 Routing Process (0) with Router-ID %s\n",
		router_id);

	/* running time */
	monotime(&now);
	timersub(&now, &o->starttime, &running);
	timerstring(&running, duration, sizeof(duration));
	vty_out(vty, " Running %s\n", duration);

	/* Redistribute configuration */
	/* XXX */

	vty_out(vty, " LSA minimum arrival %d msecs\n", o->lsa_minarrival);

	/* Show SPF parameters */
	vty_out(vty,
		" Initial SPF scheduling delay %d millisec(s)\n"
		" Minimum hold time between consecutive SPFs %d millsecond(s)\n"
		" Maximum hold time between consecutive SPFs %d millsecond(s)\n"
		" Hold time multiplier is currently %d\n",
		o->spf_delay, o->spf_holdtime, o->spf_max_holdtime,
		o->spf_hold_multiplier);

	vty_out(vty, " SPF algorithm ");
	if (o->ts_spf.tv_sec || o->ts_spf.tv_usec) {
		timersub(&now, &o->ts_spf, &result);
		timerstring(&result, buf, sizeof(buf));
		ospf6_spf_reason_string(o->last_spf_reason, rbuf, sizeof(rbuf));
		vty_out(vty, "last executed %s ago, reason %s\n", buf, rbuf);
		vty_out(vty, " Last SPF duration %lld sec %lld usec\n",
			(long long)o->ts_spf_duration.tv_sec,
			(long long)o->ts_spf_duration.tv_usec);
	} else
		vty_out(vty, "has not been run\n");
	threadtimer_string(now, o->t_spf_calc, buf, sizeof(buf));
	vty_out(vty, " SPF timer %s%s\n", (o->t_spf_calc ? "due in " : "is "),
		buf);

	if (CHECK_FLAG(o->flag, OSPF6_STUB_ROUTER))
		vty_out(vty, " Router Is Stub Router\n");

	/* LSAs */
	vty_out(vty, " Number of AS scoped LSAs is %u\n", o->lsdb->count);

	/* Areas */
	vty_out(vty, " Number of areas in this router is %u\n",
		listcount(o->area_list));

	if (CHECK_FLAG(o->config_flags, OSPF6_LOG_ADJACENCY_CHANGES)) {
		if (CHECK_FLAG(o->config_flags, OSPF6_LOG_ADJACENCY_DETAIL))
			vty_out(vty, " All adjacency changes are logged\n");
		else
			vty_out(vty, " Adjacency changes are logged\n");
	}

	vty_out(vty, "\n");

	for (ALL_LIST_ELEMENTS_RO(o->area_list, n, oa))
		ospf6_area_show(vty, oa);
}

/* show top level structures */
DEFUN (show_ipv6_ospf6,
       show_ipv6_ospf6_cmd,
       "show ipv6 ospf6",
       SHOW_STR
       IP6_STR
       OSPF6_STR)
{
	OSPF6_CMD_CHECK_RUNNING();

	ospf6_show(vty, ospf6);
	return CMD_SUCCESS;
}

DEFUN (show_ipv6_ospf6_route,
       show_ipv6_ospf6_route_cmd,
       "show ipv6 ospf6 route [<intra-area|inter-area|external-1|external-2|X:X::X:X|X:X::X:X/M|detail|summary>]",
       SHOW_STR
       IP6_STR
       OSPF6_STR
       ROUTE_STR
       "Display Intra-Area routes\n"
       "Display Inter-Area routes\n"
       "Display Type-1 External routes\n"
       "Display Type-2 External routes\n"
       "Specify IPv6 address\n"
       "Specify IPv6 prefix\n"
       "Detailed information\n"
       "Summary of route table\n")
{
	OSPF6_CMD_CHECK_RUNNING();

	ospf6_route_table_show(vty, 4, argc, argv, ospf6->route_table);
	return CMD_SUCCESS;
}

DEFUN (show_ipv6_ospf6_route_match,
       show_ipv6_ospf6_route_match_cmd,
       "show ipv6 ospf6 route X:X::X:X/M <match|longer>",
       SHOW_STR
       IP6_STR
       OSPF6_STR
       ROUTE_STR
       "Specify IPv6 prefix\n"
       "Display routes which match the specified route\n"
       "Display routes longer than the specified route\n")
{
	OSPF6_CMD_CHECK_RUNNING();

	ospf6_route_table_show(vty, 4, argc, argv, ospf6->route_table);
	return CMD_SUCCESS;
}

DEFUN (show_ipv6_ospf6_route_match_detail,
       show_ipv6_ospf6_route_match_detail_cmd,
       "show ipv6 ospf6 route X:X::X:X/M match detail",
       SHOW_STR
       IP6_STR
       OSPF6_STR
       ROUTE_STR
       "Specify IPv6 prefix\n"
       "Display routes which match the specified route\n"
       "Detailed information\n"
       )
{
	OSPF6_CMD_CHECK_RUNNING();

	ospf6_route_table_show(vty, 4, argc, argv, ospf6->route_table);
	return CMD_SUCCESS;
}


DEFUN (show_ipv6_ospf6_route_type_detail,
       show_ipv6_ospf6_route_type_detail_cmd,
       "show ipv6 ospf6 route <intra-area|inter-area|external-1|external-2> detail",
       SHOW_STR
       IP6_STR
       OSPF6_STR
       ROUTE_STR
       "Display Intra-Area routes\n"
       "Display Inter-Area routes\n"
       "Display Type-1 External routes\n"
       "Display Type-2 External routes\n"
       "Detailed information\n"
       )
{
	OSPF6_CMD_CHECK_RUNNING();

	ospf6_route_table_show(vty, 4, argc, argv, ospf6->route_table);
	return CMD_SUCCESS;
}

static void ospf6_stub_router_config_write(struct vty *vty)
{
	if (CHECK_FLAG(ospf6->flag, OSPF6_STUB_ROUTER)) {
		vty_out(vty, " stub-router administrative\n");
	}
	return;
}

static int ospf6_distance_config_write(struct vty *vty)
{
	struct route_node *rn;
	struct ospf6_distance *odistance;

	if (ospf6->distance_all)
		vty_out(vty, " distance %u\n", ospf6->distance_all);

	if (ospf6->distance_intra || ospf6->distance_inter
	    || ospf6->distance_external) {
		vty_out(vty, " distance ospf6");

		if (ospf6->distance_intra)
			vty_out(vty, " intra-area %u", ospf6->distance_intra);
		if (ospf6->distance_inter)
			vty_out(vty, " inter-area %u", ospf6->distance_inter);
		if (ospf6->distance_external)
			vty_out(vty, " external %u", ospf6->distance_external);

		vty_out(vty, "\n");
	}

	for (rn = route_top(ospf6->distance_table); rn; rn = route_next(rn))
		if ((odistance = rn->info) != NULL) {
			char buf[PREFIX_STRLEN];

			vty_out(vty, " distance %u %s %s\n",
				odistance->distance,
				prefix2str(&rn->p, buf, sizeof(buf)),
				odistance->access_list ? odistance->access_list
						       : "");
		}
	return 0;
}

/* OSPF configuration write function. */
static int config_write_ospf6(struct vty *vty)
{
	char router_id[16];
	struct listnode *j, *k;
	struct ospf6_area *oa;
	struct ospf6_interface *oi;

	/* OSPFv3 configuration. */
	if (ospf6 == NULL)
		return CMD_SUCCESS;

	inet_ntop(AF_INET, &ospf6->router_id_static, router_id,
		  sizeof(router_id));
	vty_out(vty, "router ospf6\n");
	if (ospf6->router_id_static != 0)
		vty_out(vty, " ospf6 router-id %s\n", router_id);

	/* log-adjacency-changes flag print. */
	if (CHECK_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_CHANGES)) {
		if (CHECK_FLAG(ospf6->config_flags, OSPF6_LOG_ADJACENCY_DETAIL))
			vty_out(vty, " log-adjacency-changes detail\n");
		else if (!SAVE_OSPF6_LOG_ADJACENCY_CHANGES)
			vty_out(vty, " log-adjacency-changes\n");
	} else if (SAVE_OSPF6_LOG_ADJACENCY_CHANGES) {
		vty_out(vty, " no log-adjacency-changes\n");
	}

	if (ospf6->ref_bandwidth != OSPF6_REFERENCE_BANDWIDTH)
		vty_out(vty, " auto-cost reference-bandwidth %d\n",
			ospf6->ref_bandwidth);

	/* LSA timers print. */
	if (ospf6->lsa_minarrival != OSPF_MIN_LS_ARRIVAL)
		vty_out(vty, " timers lsa min-arrival %d\n",
			ospf6->lsa_minarrival);

	ospf6_stub_router_config_write(vty);
	ospf6_redistribute_config_write(vty);
	ospf6_area_config_write(vty);
	ospf6_spf_config_write(vty);
	ospf6_distance_config_write(vty);

	for (ALL_LIST_ELEMENTS_RO(ospf6->area_list, j, oa)) {
		for (ALL_LIST_ELEMENTS_RO(oa->if_list, k, oi))
			vty_out(vty, " interface %s area %s\n",
				oi->interface->name, oa->name);
	}
	vty_out(vty, "!\n");
	return 0;
}

static int config_write_ospf6(struct vty *vty);
/* OSPF6 node structure. */
static struct cmd_node ospf6_node = {
	.name = "ospf6",
	.node = OSPF6_NODE,
	.parent_node = CONFIG_NODE,
	.prompt = "%s(config-ospf6)# ",
	.config_write = config_write_ospf6,
};

/* Install ospf related commands. */
void ospf6_top_init(void)
{
	/* Install ospf6 top node. */
	install_node(&ospf6_node);

	install_element(VIEW_NODE, &show_ipv6_ospf6_cmd);
	install_element(CONFIG_NODE, &router_ospf6_cmd);
	install_element(CONFIG_NODE, &no_router_ospf6_cmd);

	install_element(VIEW_NODE, &show_ipv6_ospf6_route_cmd);
	install_element(VIEW_NODE, &show_ipv6_ospf6_route_match_cmd);
	install_element(VIEW_NODE, &show_ipv6_ospf6_route_match_detail_cmd);
	install_element(VIEW_NODE, &show_ipv6_ospf6_route_type_detail_cmd);

	install_default(OSPF6_NODE);
	install_element(OSPF6_NODE, &ospf6_router_id_cmd);
	install_element(OSPF6_NODE, &no_ospf6_router_id_cmd);
	install_element(OSPF6_NODE, &ospf6_log_adjacency_changes_cmd);
	install_element(OSPF6_NODE, &ospf6_log_adjacency_changes_detail_cmd);
	install_element(OSPF6_NODE, &no_ospf6_log_adjacency_changes_cmd);
	install_element(OSPF6_NODE, &no_ospf6_log_adjacency_changes_detail_cmd);

	/* LSA timers commands */
	install_element(OSPF6_NODE, &ospf6_timers_lsa_cmd);
	install_element(OSPF6_NODE, &no_ospf6_timers_lsa_cmd);

	install_element(OSPF6_NODE, &ospf6_interface_area_cmd);
	install_element(OSPF6_NODE, &no_ospf6_interface_area_cmd);
	install_element(OSPF6_NODE, &ospf6_stub_router_admin_cmd);
	install_element(OSPF6_NODE, &no_ospf6_stub_router_admin_cmd);
/* For a later time */
#if 0
  install_element (OSPF6_NODE, &ospf6_stub_router_startup_cmd);
  install_element (OSPF6_NODE, &no_ospf6_stub_router_startup_cmd);
  install_element (OSPF6_NODE, &ospf6_stub_router_shutdown_cmd);
  install_element (OSPF6_NODE, &no_ospf6_stub_router_shutdown_cmd);
#endif

	install_element(OSPF6_NODE, &ospf6_distance_cmd);
	install_element(OSPF6_NODE, &no_ospf6_distance_cmd);
	install_element(OSPF6_NODE, &ospf6_distance_ospf6_cmd);
	install_element(OSPF6_NODE, &no_ospf6_distance_ospf6_cmd);
#if 0
  install_element (OSPF6_NODE, &ospf6_distance_source_cmd);
  install_element (OSPF6_NODE, &no_ospf6_distance_source_cmd);
#endif
}