/*
 * Zebra connect library for OSPFd
 * Copyright (C) 1997, 98, 99, 2000 Kunihiro Ishiguro, Toshiaki Takada
 *
 * 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 "thread.h"
#include "command.h"
#include "network.h"
#include "prefix.h"
#include "routemap.h"
#include "table.h"
#include "stream.h"
#include "memory.h"
#include "zclient.h"
#include "filter.h"
#include "plist.h"
#include "log.h"
#include "route_opaque.h"
#include "lib/bfd.h"
#include "nexthop.h"

#include "ospfd/ospfd.h"
#include "ospfd/ospf_interface.h"
#include "ospfd/ospf_ism.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_abr.h"
#include "ospfd/ospf_lsa.h"
#include "ospfd/ospf_dump.h"
#include "ospfd/ospf_route.h"
#include "ospfd/ospf_lsdb.h"
#include "ospfd/ospf_neighbor.h"
#include "ospfd/ospf_nsm.h"
#include "ospfd/ospf_zebra.h"
#include "ospfd/ospf_te.h"
#include "ospfd/ospf_sr.h"
#include "ospfd/ospf_ldp_sync.h"
#include "ospfd/ospf_orr.h"

DEFINE_MTYPE_STATIC(OSPFD, OSPF_EXTERNAL, "OSPF External route table");
DEFINE_MTYPE_STATIC(OSPFD, OSPF_REDISTRIBUTE, "OSPF Redistriute");


/* Zebra structure to hold current status. */
struct zclient *zclient = NULL;
/* and for the Synchronous connection to the Label Manager */
static struct zclient *zclient_sync;

/* For registering threads. */
extern struct thread_master *master;

/* Router-id update message from zebra. */
static int ospf_router_id_update_zebra(ZAPI_CALLBACK_ARGS)
{
	struct ospf *ospf = NULL;
	struct prefix router_id;
	zebra_router_id_update_read(zclient->ibuf, &router_id);

	if (IS_DEBUG_OSPF(zebra, ZEBRA_INTERFACE))
		zlog_debug("Zebra rcvd: router id update %pFX vrf %s id %u",
			   &router_id, ospf_vrf_id_to_name(vrf_id), vrf_id);

	ospf = ospf_lookup_by_vrf_id(vrf_id);

	if (ospf != NULL) {
		ospf->router_id_zebra = router_id.u.prefix4;
		ospf_router_id_update(ospf);
	} else {
		if (IS_DEBUG_OSPF_EVENT)
			zlog_debug(
				"%s: ospf instance not found for vrf %s id %u router_id %pFX",
				__func__, ospf_vrf_id_to_name(vrf_id), vrf_id,
				&router_id);
	}
	return 0;
}

static int ospf_interface_address_add(ZAPI_CALLBACK_ARGS)
{
	struct connected *c;
	struct ospf *ospf = NULL;


	c = zebra_interface_address_read(cmd, zclient->ibuf, vrf_id);

	if (c == NULL)
		return 0;

	if (IS_DEBUG_OSPF(zebra, ZEBRA_INTERFACE))
		zlog_debug("Zebra: interface %s address add %pFX vrf %s id %u",
			   c->ifp->name, c->address,
			   ospf_vrf_id_to_name(vrf_id), vrf_id);

	ospf = ospf_lookup_by_vrf_id(vrf_id);
	if (!ospf)
		return 0;

	ospf_if_update(ospf, c->ifp);

	ospf_if_interface(c->ifp);

	return 0;
}

static int ospf_interface_address_delete(ZAPI_CALLBACK_ARGS)
{
	struct connected *c;
	struct interface *ifp;
	struct ospf_interface *oi;
	struct route_node *rn;
	struct prefix p;

	c = zebra_interface_address_read(cmd, zclient->ibuf, vrf_id);

	if (c == NULL)
		return 0;

	if (IS_DEBUG_OSPF(zebra, ZEBRA_INTERFACE))
		zlog_debug("Zebra: interface %s address delete %pFX",
			   c->ifp->name, c->address);

	ifp = c->ifp;
	p = *c->address;
	p.prefixlen = IPV4_MAX_BITLEN;

	rn = route_node_lookup(IF_OIFS(ifp), &p);
	if (!rn) {
		connected_free(&c);
		return 0;
	}

	assert(rn->info);
	oi = rn->info;
	route_unlock_node(rn);

	/* Call interface hook functions to clean up */
	ospf_if_free(oi);

	ospf_if_interface(c->ifp);

	connected_free(&c);

	return 0;
}

static int ospf_interface_link_params(ZAPI_CALLBACK_ARGS)
{
	struct interface *ifp;
	bool changed = false;

	ifp = zebra_interface_link_params_read(zclient->ibuf, vrf_id, &changed);

	if (ifp == NULL || !changed)
		return 0;

	/* Update TE TLV */
	ospf_mpls_te_update_if(ifp);

	return 0;
}

/* VRF update for an interface. */
static int ospf_interface_vrf_update(ZAPI_CALLBACK_ARGS)
{
	struct interface *ifp = NULL;
	vrf_id_t new_vrf_id;

	ifp = zebra_interface_vrf_update_read(zclient->ibuf, vrf_id,
					      &new_vrf_id);
	if (!ifp)
		return 0;

	if (IS_DEBUG_OSPF_EVENT)
		zlog_debug(
			"%s: Rx Interface %s VRF change vrf_id %u New vrf %s id %u",
			__func__, ifp->name, vrf_id,
			ospf_vrf_id_to_name(new_vrf_id), new_vrf_id);

	/*if_update(ifp, ifp->name, strlen(ifp->name), new_vrf_id);*/
	if_update_to_new_vrf(ifp, new_vrf_id);

	return 0;
}

/* Nexthop, ifindex, distance and metric information. */
static void ospf_zebra_add_nexthop(struct ospf *ospf, struct ospf_path *path,
				   struct zapi_route *api)
{
	struct zapi_nexthop *api_nh;
	struct zapi_nexthop *api_nh_backup;

	/* TI-LFA backup path label stack comes first, if present */
	if (path->srni.backup_label_stack) {
		api_nh_backup = &api->backup_nexthops[api->backup_nexthop_num];
		api_nh_backup->vrf_id = ospf->vrf_id;

		api_nh_backup->type = NEXTHOP_TYPE_IPV4;
		api_nh_backup->gate.ipv4 = path->srni.backup_nexthop;

		api_nh_backup->label_num =
			path->srni.backup_label_stack->num_labels;
		memcpy(api_nh_backup->labels,
		       path->srni.backup_label_stack->label,
		       sizeof(mpls_label_t) * api_nh_backup->label_num);

		api->backup_nexthop_num++;
	}

	/* And here comes the primary nexthop */
	api_nh = &api->nexthops[api->nexthop_num];
#ifdef HAVE_NETLINK
	if (path->unnumbered
	    || (path->nexthop.s_addr != INADDR_ANY && path->ifindex != 0)) {
#else  /* HAVE_NETLINK */
	if (path->nexthop.s_addr != INADDR_ANY && path->ifindex != 0) {
#endif /* HAVE_NETLINK */
		api_nh->gate.ipv4 = path->nexthop;
		api_nh->ifindex = path->ifindex;
		api_nh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
	} else if (path->nexthop.s_addr != INADDR_ANY) {
		api_nh->gate.ipv4 = path->nexthop;
		api_nh->type = NEXTHOP_TYPE_IPV4;
	} else {
		api_nh->ifindex = path->ifindex;
		api_nh->type = NEXTHOP_TYPE_IFINDEX;
	}
	api_nh->vrf_id = ospf->vrf_id;

	/* Set TI-LFA backup nexthop info if present */
	if (path->srni.backup_label_stack) {
		SET_FLAG(api->message, ZAPI_MESSAGE_BACKUP_NEXTHOPS);
		SET_FLAG(api_nh->flags, ZAPI_NEXTHOP_FLAG_HAS_BACKUP);

		/* Just care about a single TI-LFA backup path for now */
		api_nh->backup_num = 1;
		api_nh->backup_idx[0] = api->backup_nexthop_num - 1;
	}

	api->nexthop_num++;
}

static void ospf_zebra_append_opaque_attr(struct ospf_route *or,
					  struct zapi_route *api)
{
	struct ospf_zebra_opaque ospf_opaque = {};

	/* OSPF path type */
	snprintf(ospf_opaque.path_type, sizeof(ospf_opaque.path_type), "%s",
		 ospf_path_type_name(or->path_type));

	switch (or->path_type) {
	case OSPF_PATH_INTRA_AREA:
	case OSPF_PATH_INTER_AREA:
		/* OSPF area ID */
		(void)inet_ntop(AF_INET, &or->u.std.area_id,
				ospf_opaque.area_id,
				sizeof(ospf_opaque.area_id));
		break;
	case OSPF_PATH_TYPE1_EXTERNAL:
	case OSPF_PATH_TYPE2_EXTERNAL:
		/* OSPF route tag */
		snprintf(ospf_opaque.tag, sizeof(ospf_opaque.tag), "%u",
			 or->u.ext.tag);
		break;
	default:
		break;
	}

	SET_FLAG(api->message, ZAPI_MESSAGE_OPAQUE);
	api->opaque.length = sizeof(struct ospf_zebra_opaque);
	memcpy(api->opaque.data, &ospf_opaque, api->opaque.length);
}

void ospf_zebra_add(struct ospf *ospf, struct prefix_ipv4 *p,
		    struct ospf_route * or)
{
	struct zapi_route api;
	uint8_t distance;
	struct ospf_path *path;
	struct listnode *node;

	if (ospf->gr_info.restart_in_progress) {
		if (IS_DEBUG_OSPF_GR)
			zlog_debug(
				"Zebra: Graceful Restart in progress -- not installing %pFX",
				p);
		return;
	}

	memset(&api, 0, sizeof(api));
	api.vrf_id = ospf->vrf_id;
	api.type = ZEBRA_ROUTE_OSPF;
	api.instance = ospf->instance;
	api.safi = SAFI_UNICAST;

	memcpy(&api.prefix, p, sizeof(*p));
	SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);

	/* Metric value. */
	SET_FLAG(api.message, ZAPI_MESSAGE_METRIC);
	if (or->path_type == OSPF_PATH_TYPE1_EXTERNAL)
		api.metric = or->cost + or->u.ext.type2_cost;
	else if (or->path_type == OSPF_PATH_TYPE2_EXTERNAL)
		api.metric = or->u.ext.type2_cost;
	else
		api.metric = or->cost;

	/* Check if path type is ASE */
	if (((or->path_type == OSPF_PATH_TYPE1_EXTERNAL)
	     || (or->path_type == OSPF_PATH_TYPE2_EXTERNAL))
	    && (or->u.ext.tag > 0) && (or->u.ext.tag <= ROUTE_TAG_MAX)) {
		SET_FLAG(api.message, ZAPI_MESSAGE_TAG);
		api.tag = or->u.ext.tag;
	}

	/* Distance value. */
	distance = ospf_distance_apply(ospf, p, or);
	if (distance) {
		SET_FLAG(api.message, ZAPI_MESSAGE_DISTANCE);
		api.distance = distance;
	}

	for (ALL_LIST_ELEMENTS_RO(or->paths, node, path)) {
		if (api.nexthop_num >= ospf->max_multipath)
			break;

		ospf_zebra_add_nexthop(ospf, path, &api);

		if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE)) {
			struct interface *ifp;

			ifp = if_lookup_by_index(path->ifindex, ospf->vrf_id);

			zlog_debug(
				"Zebra: Route add %pFX nexthop %pI4, ifindex=%d %s",
				p, &path->nexthop, path->ifindex,
				ifp ? ifp->name : " ");
		}
	}

	if (CHECK_FLAG(ospf->config, OSPF_SEND_EXTRA_DATA_TO_ZEBRA))
		ospf_zebra_append_opaque_attr(or, &api);

	zclient_route_send(ZEBRA_ROUTE_ADD, zclient, &api);
}

void ospf_zebra_delete(struct ospf *ospf, struct prefix_ipv4 *p,
		       struct ospf_route * or)
{
	struct zapi_route api;

	if (ospf->gr_info.restart_in_progress) {
		if (IS_DEBUG_OSPF_GR)
			zlog_debug(
				"Zebra: Graceful Restart in progress -- not uninstalling %pFX",
				p);
		return;
	}

	memset(&api, 0, sizeof(api));
	api.vrf_id = ospf->vrf_id;
	api.type = ZEBRA_ROUTE_OSPF;
	api.instance = ospf->instance;
	api.safi = SAFI_UNICAST;
	memcpy(&api.prefix, p, sizeof(*p));

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug("Zebra: Route delete %pFX", p);

	zclient_route_send(ZEBRA_ROUTE_DELETE, zclient, &api);
}

void ospf_zebra_add_discard(struct ospf *ospf, struct prefix_ipv4 *p)
{
	struct zapi_route api;

	if (ospf->gr_info.restart_in_progress) {
		if (IS_DEBUG_OSPF_GR)
			zlog_debug(
				"Zebra: Graceful Restart in progress -- not installing %pFX",
				p);
		return;
	}

	memset(&api, 0, sizeof(api));
	api.vrf_id = ospf->vrf_id;
	api.type = ZEBRA_ROUTE_OSPF;
	api.instance = ospf->instance;
	api.safi = SAFI_UNICAST;
	memcpy(&api.prefix, p, sizeof(*p));
	zapi_route_set_blackhole(&api, BLACKHOLE_NULL);

	zclient_route_send(ZEBRA_ROUTE_ADD, zclient, &api);

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug("Zebra: Route add discard %pFX", p);
}

void ospf_zebra_delete_discard(struct ospf *ospf, struct prefix_ipv4 *p)
{
	struct zapi_route api;

	if (ospf->gr_info.restart_in_progress) {
		if (IS_DEBUG_OSPF_GR)
			zlog_debug(
				"Zebra: Graceful Restart in progress -- not uninstalling %pFX",
				p);
		return;
	}

	memset(&api, 0, sizeof(api));
	api.vrf_id = ospf->vrf_id;
	api.type = ZEBRA_ROUTE_OSPF;
	api.instance = ospf->instance;
	api.safi = SAFI_UNICAST;
	memcpy(&api.prefix, p, sizeof(*p));
	zapi_route_set_blackhole(&api, BLACKHOLE_NULL);

	zclient_route_send(ZEBRA_ROUTE_DELETE, zclient, &api);

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug("Zebra: Route delete discard %pFX", p);
}

struct ospf_external *ospf_external_lookup(struct ospf *ospf, uint8_t type,
					   unsigned short instance)
{
	struct list *ext_list;
	struct listnode *node;
	struct ospf_external *ext;

	ext_list = ospf->external[type];
	if (!ext_list)
		return (NULL);

	for (ALL_LIST_ELEMENTS_RO(ext_list, node, ext))
		if (ext->instance == instance)
			return ext;

	return NULL;
}

struct ospf_external *ospf_external_add(struct ospf *ospf, uint8_t type,
					unsigned short instance)
{
	struct list *ext_list;
	struct ospf_external *ext;

	ext = ospf_external_lookup(ospf, type, instance);
	if (ext)
		return ext;

	if (!ospf->external[type])
		ospf->external[type] = list_new();

	ext_list = ospf->external[type];
	ext = XCALLOC(MTYPE_OSPF_EXTERNAL, sizeof(struct ospf_external));
	ext->instance = instance;
	EXTERNAL_INFO(ext) = route_table_init();

	listnode_add(ext_list, ext);

	return ext;
}

/*
 * Walk all the ei received from zebra for a route type and apply
 * default route-map.
 */
bool ospf_external_default_routemap_apply_walk(struct ospf *ospf,
					       struct list *ext_list,
					       struct external_info *default_ei)
{
	struct listnode *node;
	struct ospf_external *ext;
	struct route_node *rn;
	struct external_info *ei = NULL;
	int ret = 0;

	for (ALL_LIST_ELEMENTS_RO(ext_list, node, ext)) {
		if (!ext->external_info)
			continue;

		for (rn = route_top(ext->external_info); rn;
		     rn = route_next(rn)) {
			ei = rn->info;
			if (!ei)
				continue;
			ret = ospf_external_info_apply_default_routemap(
				ospf, ei, default_ei);
			if (ret)
				break;
		}
	}

	if (ret && ei) {
		if (IS_DEBUG_OSPF_DEFAULT_INFO)
			zlog_debug("Default originate routemap permit ei: %pI4",
				   &ei->p.prefix);
		return true;
	}

	return false;
}

/*
 * Function to originate or flush default after applying
 * route-map on all ei.
 */
static void ospf_external_lsa_default_routemap_timer(struct thread *thread)
{
	struct list *ext_list;
	struct ospf *ospf = THREAD_ARG(thread);
	struct prefix_ipv4 p;
	int type;
	int ret = 0;
	struct ospf_lsa *lsa;
	struct external_info *default_ei;

	p.family = AF_INET;
	p.prefixlen = 0;
	p.prefix.s_addr = INADDR_ANY;

	/* Get the default extenal info. */
	default_ei = ospf_external_info_lookup(ospf, DEFAULT_ROUTE,
					       ospf->instance, &p);
	if (!default_ei) {
		/* Nothing to be done here. */
		if (IS_DEBUG_OSPF_DEFAULT_INFO)
			zlog_debug("Default originate info not present");
		return;
	}

	/* For all the ei apply route-map */
	for (type = 0; type <= ZEBRA_ROUTE_MAX; type++) {
		ext_list = ospf->external[type];
		if (!ext_list || type == ZEBRA_ROUTE_OSPF)
			continue;

		ret = ospf_external_default_routemap_apply_walk(ospf, ext_list,
								default_ei);
		if (ret)
			break;
	}

	/* Get the default LSA. */
	lsa = ospf_external_info_find_lsa(ospf, &p);

	/* If permit then originate default. */
	if (ret && !lsa)
		ospf_external_lsa_originate(ospf, default_ei);
	else if (ret && lsa && IS_LSA_MAXAGE(lsa))
		ospf_external_lsa_refresh(ospf, lsa, default_ei, true, false);
	else if (!ret && lsa)
		ospf_external_lsa_flush(ospf, DEFAULT_ROUTE, &default_ei->p, 0);
}


void ospf_external_del(struct ospf *ospf, uint8_t type, unsigned short instance)
{
	struct ospf_external *ext;

	ext = ospf_external_lookup(ospf, type, instance);

	if (ext) {
		if (EXTERNAL_INFO(ext))
			route_table_finish(EXTERNAL_INFO(ext));

		listnode_delete(ospf->external[type], ext);

		if (!ospf->external[type]->count)
			list_delete(&ospf->external[type]);

		XFREE(MTYPE_OSPF_EXTERNAL, ext);
	}

	/*
	 * Check if default needs to be flushed too.
	 */
	thread_add_event(master, ospf_external_lsa_default_routemap_timer, ospf,
			 0, &ospf->t_default_routemap_timer);
}

/* Update NHLFE for Prefix SID */
void ospf_zebra_update_prefix_sid(const struct sr_prefix *srp)
{
	struct zapi_labels zl;
	struct zapi_nexthop *znh;
	struct zapi_nexthop *znh_backup;
	struct listnode *node;
	struct ospf_path *path;

	/* Prepare message. */
	memset(&zl, 0, sizeof(zl));
	zl.type = ZEBRA_LSP_OSPF_SR;
	zl.local_label = srp->label_in;

	switch (srp->type) {
	case LOCAL_SID:
		/* Set Label for local Prefix */
		znh = &zl.nexthops[zl.nexthop_num++];
		znh->type = NEXTHOP_TYPE_IFINDEX;
		znh->ifindex = srp->nhlfe.ifindex;
		znh->label_num = 1;
		znh->labels[0] = srp->nhlfe.label_out;

		osr_debug("SR (%s): Configure Prefix %pFX with labels %u/%u",
			  __func__, (struct prefix *)&srp->prefv4,
			  srp->label_in, srp->nhlfe.label_out);

		break;

	case PREF_SID:
		/* Update route in the RIB too. */
		SET_FLAG(zl.message, ZAPI_LABELS_FTN);
		zl.route.prefix.u.prefix4 = srp->prefv4.prefix;
		zl.route.prefix.prefixlen = srp->prefv4.prefixlen;
		zl.route.prefix.family = srp->prefv4.family;
		zl.route.type = ZEBRA_ROUTE_OSPF;
		zl.route.instance = 0;

		/* Check that SRP contains at least one valid path */
		if (srp->route == NULL) {
			return;
		}

		osr_debug("SR (%s): Configure Prefix %pFX with",
			  __func__, (struct prefix *)&srp->prefv4);

		for (ALL_LIST_ELEMENTS_RO(srp->route->paths, node, path)) {
			if (path->srni.label_out == MPLS_INVALID_LABEL)
				continue;

			if (zl.nexthop_num >= MULTIPATH_NUM)
				break;

			/*
			 * TI-LFA backup path label stack comes first, if
			 * present.
			 */
			if (path->srni.backup_label_stack) {
				znh_backup = &zl.backup_nexthops
						      [zl.backup_nexthop_num++];
				znh_backup->type = NEXTHOP_TYPE_IPV4;
				znh_backup->gate.ipv4 =
					path->srni.backup_nexthop;

				memcpy(znh_backup->labels,
				       path->srni.backup_label_stack->label,
				       sizeof(mpls_label_t)
					       * path->srni.backup_label_stack
							 ->num_labels);

				znh_backup->label_num =
					path->srni.backup_label_stack
						->num_labels;
				if (path->srni.label_out
					    != MPLS_LABEL_IPV4_EXPLICIT_NULL
				    && path->srni.label_out
					       != MPLS_LABEL_IMPLICIT_NULL)
					znh_backup->labels
						[znh_backup->label_num++] =
						path->srni.label_out;
			}

			znh = &zl.nexthops[zl.nexthop_num++];
			znh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
			znh->gate.ipv4 = path->nexthop;
			znh->ifindex = path->ifindex;
			znh->label_num = 1;
			znh->labels[0] = path->srni.label_out;

			osr_debug("  |- labels %u/%u", srp->label_in,
				  path->srni.label_out);

			/* Set TI-LFA backup nexthop info if present */
			if (path->srni.backup_label_stack) {
				SET_FLAG(zl.message, ZAPI_LABELS_HAS_BACKUPS);
				SET_FLAG(znh->flags,
					 ZAPI_NEXTHOP_FLAG_HAS_BACKUP);

				/* Just care about a single TI-LFA backup path
				 * for now */
				znh->backup_num = 1;
				znh->backup_idx[0] = zl.backup_nexthop_num - 1;
			}
		}
		break;
	case ADJ_SID:
	case LAN_ADJ_SID:
		return;
	}

	/* Finally, send message to zebra. */
	(void)zebra_send_mpls_labels(zclient, ZEBRA_MPLS_LABELS_REPLACE, &zl);
}

/* Remove NHLFE for Prefix-SID */
void ospf_zebra_delete_prefix_sid(const struct sr_prefix *srp)
{
	struct zapi_labels zl;

	osr_debug("SR (%s): Delete Labels %u for Prefix %pFX", __func__,
		  srp->label_in, (struct prefix *)&srp->prefv4);

	/* Prepare message. */
	memset(&zl, 0, sizeof(zl));
	zl.type = ZEBRA_LSP_OSPF_SR;
	zl.local_label = srp->label_in;

	if (srp->type == PREF_SID) {
		/* Update route in the RIB too */
		SET_FLAG(zl.message, ZAPI_LABELS_FTN);
		zl.route.prefix.u.prefix4 = srp->prefv4.prefix;
		zl.route.prefix.prefixlen = srp->prefv4.prefixlen;
		zl.route.prefix.family = srp->prefv4.family;
		zl.route.type = ZEBRA_ROUTE_OSPF;
		zl.route.instance = 0;
	}

	/* Send message to zebra. */
	(void)zebra_send_mpls_labels(zclient, ZEBRA_MPLS_LABELS_DELETE, &zl);
}

/* Send MPLS Label entry to Zebra for installation or deletion */
void ospf_zebra_send_adjacency_sid(int cmd, struct sr_nhlfe nhlfe)
{
	struct zapi_labels zl;
	struct zapi_nexthop *znh;

	osr_debug("SR (%s): %s Labels %u/%u for Adjacency via %u", __func__,
		  cmd == ZEBRA_MPLS_LABELS_ADD ? "Add" : "Delete",
		  nhlfe.label_in, nhlfe.label_out, nhlfe.ifindex);

	memset(&zl, 0, sizeof(zl));
	zl.type = ZEBRA_LSP_OSPF_SR;
	zl.local_label = nhlfe.label_in;
	zl.nexthop_num = 1;
	znh = &zl.nexthops[0];
	znh->type = NEXTHOP_TYPE_IPV4_IFINDEX;
	znh->gate.ipv4 = nhlfe.nexthop;
	znh->ifindex = nhlfe.ifindex;
	znh->label_num = 1;
	znh->labels[0] = nhlfe.label_out;

	(void)zebra_send_mpls_labels(zclient, cmd, &zl);
}

struct ospf_redist *ospf_redist_lookup(struct ospf *ospf, uint8_t type,
				       unsigned short instance)
{
	struct list *red_list;
	struct listnode *node;
	struct ospf_redist *red;

	red_list = ospf->redist[type];
	if (!red_list)
		return (NULL);

	for (ALL_LIST_ELEMENTS_RO(red_list, node, red))
		if (red->instance == instance)
			return red;

	return NULL;
}

struct ospf_redist *ospf_redist_add(struct ospf *ospf, uint8_t type,
				    unsigned short instance)
{
	struct list *red_list;
	struct ospf_redist *red;

	red = ospf_redist_lookup(ospf, type, instance);
	if (red)
		return red;

	if (!ospf->redist[type])
		ospf->redist[type] = list_new();

	red_list = ospf->redist[type];
	red = XCALLOC(MTYPE_OSPF_REDISTRIBUTE, sizeof(struct ospf_redist));
	red->instance = instance;
	red->dmetric.type = -1;
	red->dmetric.value = -1;
	ROUTEMAP_NAME(red) = NULL;
	ROUTEMAP(red) = NULL;

	listnode_add(red_list, red);

	return red;
}

void ospf_redist_del(struct ospf *ospf, uint8_t type, unsigned short instance)
{
	struct ospf_redist *red;

	red = ospf_redist_lookup(ospf, type, instance);

	if (red) {
		listnode_delete(ospf->redist[type], red);
		if (!ospf->redist[type]->count) {
			list_delete(&ospf->redist[type]);
		}
		ospf_routemap_unset(red);
		XFREE(MTYPE_OSPF_REDISTRIBUTE, red);
	}
}


int ospf_is_type_redistributed(struct ospf *ospf, int type,
			       unsigned short instance)
{
	return (DEFAULT_ROUTE_TYPE(type)
			? vrf_bitmap_check(zclient->default_information[AFI_IP],
					   ospf->vrf_id)
			: ((instance
			    && redist_check_instance(
				    &zclient->mi_redist[AFI_IP][type],
				    instance))
			   || (!instance
			       && vrf_bitmap_check(
				       zclient->redist[AFI_IP][type],
				       ospf->vrf_id))));
}

int ospf_redistribute_update(struct ospf *ospf, struct ospf_redist *red,
			     int type, unsigned short instance, int mtype,
			     int mvalue)
{
	int force = 0;

	if (mtype != red->dmetric.type) {
		red->dmetric.type = mtype;
		force = LSA_REFRESH_FORCE;
	}
	if (mvalue != red->dmetric.value) {
		red->dmetric.value = mvalue;
		force = LSA_REFRESH_FORCE;
	}

	ospf_external_lsa_refresh_type(ospf, type, instance, force);

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug(
			"Redistribute[%s][%d]: Refresh  Type[%d], Metric[%d]",
			ospf_redist_string(type), instance,
			metric_type(ospf, type, instance),
			metric_value(ospf, type, instance));

	return CMD_SUCCESS;
}

int ospf_redistribute_set(struct ospf *ospf, struct ospf_redist *red, int type,
			  unsigned short instance, int mtype, int mvalue)
{
	red->dmetric.type = mtype;
	red->dmetric.value = mvalue;

	ospf_external_add(ospf, type, instance);

	zclient_redistribute(ZEBRA_REDISTRIBUTE_ADD, zclient, AFI_IP, type,
			     instance, ospf->vrf_id);

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug(
			"Redistribute[%s][%d] vrf id %u: Start  Type[%d], Metric[%d]",
			ospf_redist_string(type), instance, ospf->vrf_id,
			metric_type(ospf, type, instance),
			metric_value(ospf, type, instance));

	ospf_asbr_status_update(ospf, ++ospf->redistribute);

	return CMD_SUCCESS;
}

int ospf_redistribute_unset(struct ospf *ospf, int type,
			    unsigned short instance)
{
	if (type == zclient->redist_default && instance == zclient->instance)
		return CMD_SUCCESS;

	zclient_redistribute(ZEBRA_REDISTRIBUTE_DELETE, zclient, AFI_IP, type,
			     instance, ospf->vrf_id);

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug("Redistribute[%s][%d] vrf id %u: Stop",
			   ospf_redist_string(type), instance, ospf->vrf_id);

	/* Remove the routes from OSPF table. */
	ospf_redistribute_withdraw(ospf, type, instance);

	ospf_external_del(ospf, type, instance);

	ospf_asbr_status_update(ospf, --ospf->redistribute);

	return CMD_SUCCESS;
}

int ospf_redistribute_default_set(struct ospf *ospf, int originate, int mtype,
				  int mvalue)
{
	struct prefix_ipv4 p;
	struct in_addr nexthop;
	int cur_originate = ospf->default_originate;
	const char *type_str = NULL;

	nexthop.s_addr = INADDR_ANY;
	p.family = AF_INET;
	p.prefix.s_addr = INADDR_ANY;
	p.prefixlen = 0;

	ospf->default_originate = originate;

	if (cur_originate == originate) {
		/* Refresh the lsa since metric might different */
		if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
			zlog_debug(
				"Redistribute[%s]: Refresh  Type[%d], Metric[%d]",
				ospf_redist_string(DEFAULT_ROUTE),
				metric_type(ospf, DEFAULT_ROUTE, 0),
				metric_value(ospf, DEFAULT_ROUTE, 0));

		ospf_external_lsa_refresh_default(ospf);
		return CMD_SUCCESS;
	}

	switch (cur_originate) {
	case DEFAULT_ORIGINATE_NONE:
		break;
	case DEFAULT_ORIGINATE_ZEBRA:
		zclient_redistribute_default(ZEBRA_REDISTRIBUTE_DEFAULT_DELETE,
				 zclient, AFI_IP, ospf->vrf_id);
		ospf->redistribute--;
		break;
	case DEFAULT_ORIGINATE_ALWAYS:
		ospf_external_info_delete(ospf, DEFAULT_ROUTE, 0, p);
		ospf_external_del(ospf, DEFAULT_ROUTE, 0);
		ospf->redistribute--;
		break;
	}

	switch (originate) {
	case DEFAULT_ORIGINATE_NONE:
		type_str = "none";
		break;
	case DEFAULT_ORIGINATE_ZEBRA:
		type_str = "normal";
		ospf->redistribute++;
		zclient_redistribute_default(ZEBRA_REDISTRIBUTE_DEFAULT_ADD,
					     zclient, AFI_IP, ospf->vrf_id);
		break;
	case DEFAULT_ORIGINATE_ALWAYS:
		type_str = "always";
		ospf->redistribute++;
		ospf_external_add(ospf, DEFAULT_ROUTE, 0);
		ospf_external_info_add(ospf, DEFAULT_ROUTE, 0, p, 0, nexthop,
				       0);
		break;
	}

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug("Redistribute[DEFAULT]: %s Type[%d], Metric[%d]",
		type_str,
		metric_type(ospf, DEFAULT_ROUTE, 0),
		metric_value(ospf, DEFAULT_ROUTE, 0));

	ospf_external_lsa_refresh_default(ospf);
	ospf_asbr_status_update(ospf, ospf->redistribute);
	return CMD_SUCCESS;
}

static int ospf_external_lsa_originate_check(struct ospf *ospf,
					     struct external_info *ei)
{
	/* If prefix is multicast, then do not originate LSA. */
	if (IN_MULTICAST(htonl(ei->p.prefix.s_addr))) {
		zlog_info(
			"LSA[Type5:%pI4]: Not originate AS-external-LSA, Prefix belongs multicast",
			&ei->p.prefix);
		return 0;
	}

	/* Take care of default-originate. */
	if (is_default_prefix4(&ei->p))
		if (ospf->default_originate == DEFAULT_ORIGINATE_NONE) {
			zlog_info(
				"LSA[Type5:0.0.0.0]: Not originate AS-external-LSA for default");
			return 0;
		}

	return 1;
}

/* If connected prefix is OSPF enable interface, then do not announce. */
int ospf_distribute_check_connected(struct ospf *ospf, struct external_info *ei)
{
	struct listnode *node;
	struct ospf_interface *oi;


	for (ALL_LIST_ELEMENTS_RO(ospf->oiflist, node, oi))
		if (prefix_match(oi->address, (struct prefix *)&ei->p))
			return 0;
	return 1;
}


/* Apply default route-map on ei received. */
int ospf_external_info_apply_default_routemap(struct ospf *ospf,
					      struct external_info *ei,
					      struct external_info *default_ei)
{
	struct ospf_redist *red;
	int type = default_ei->type;
	struct prefix_ipv4 *p = &ei->p;
	struct route_map_set_values save_values;


	if (!ospf_external_lsa_originate_check(ospf, default_ei))
		return 0;

	save_values = default_ei->route_map_set;
	ospf_reset_route_map_set_values(&default_ei->route_map_set);

	/* apply route-map if needed */
	red = ospf_redist_lookup(ospf, type, ospf->instance);
	if (red && ROUTEMAP_NAME(red)) {
		route_map_result_t ret;

		ret = route_map_apply(ROUTEMAP(red), (struct prefix *)p, ei);

		if (ret == RMAP_DENYMATCH) {
			ei->route_map_set = save_values;
			return 0;
		}
	}

	return 1;
}


/*
 * Default originated is based on route-map condition then
 * apply route-map on received external info. Originate or
 * flush based on route-map condition.
 */
static bool ospf_external_lsa_default_routemap_apply(struct ospf *ospf,
						     struct external_info *ei,
						     int cmd)
{
	struct external_info *default_ei;
	struct prefix_ipv4 p;
	struct ospf_lsa *lsa;
	int ret;

	p.family = AF_INET;
	p.prefixlen = 0;
	p.prefix.s_addr = INADDR_ANY;


	/* Get the default extenal info. */
	default_ei = ospf_external_info_lookup(ospf, DEFAULT_ROUTE,
					       ospf->instance, &p);
	if (!default_ei) {
		/* Nothing to be done here. */
		return false;
	}

	if (IS_DEBUG_OSPF_DEFAULT_INFO)
		zlog_debug("Apply default originate routemap on ei: %pI4 cmd: %d",
			   &ei->p.prefix, cmd);

	ret = ospf_external_info_apply_default_routemap(ospf, ei, default_ei);

	/* If deny then nothing to be done both in add and del case. */
	if (!ret) {
		if (IS_DEBUG_OSPF_DEFAULT_INFO)
			zlog_debug("Default originte routemap deny for ei: %pI4",
				   &ei->p.prefix);
		return false;
	}

	/* Get the default LSA. */
	lsa = ospf_external_info_find_lsa(ospf, &p);

	/* If this is add route and permit then ooriginate default. */
	if (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD) {
		/* If permit and default already advertise then return. */
		if (lsa && !IS_LSA_MAXAGE(lsa)) {
			if (IS_DEBUG_OSPF_DEFAULT_INFO)
				zlog_debug("Default lsa already originated");
			return true;
		}

		if (IS_DEBUG_OSPF_DEFAULT_INFO)
			zlog_debug("Originating/Refreshing default lsa");

		if (lsa && IS_LSA_MAXAGE(lsa))
			/* Refresh lsa.*/
			ospf_external_lsa_refresh(ospf, lsa, default_ei, true,
						  false);
		else
			/* If permit and default not advertised then advertise.
			 */
			ospf_external_lsa_originate(ospf, default_ei);

	} else if (cmd == ZEBRA_REDISTRIBUTE_ROUTE_DEL) {
		/* If deny and lsa is not originated then nothing to be done.*/
		if (!lsa) {
			if (IS_DEBUG_OSPF_DEFAULT_INFO)
				zlog_debug(
					"Default lsa not originated, not flushing");
			return true;
		}

		if (IS_DEBUG_OSPF_DEFAULT_INFO)
			zlog_debug(
				"Running default route-map again as ei: %pI4 deleted",
				&ei->p.prefix);
		/*
		 * if this route delete was permitted then we need to check
		 * there are any other external info which can still trigger
		 * default route origination else flush it.
		 */
		thread_add_event(master,
				 ospf_external_lsa_default_routemap_timer, ospf,
				 0, &ospf->t_default_routemap_timer);
	}

	return true;
}

/* return 1 if external LSA must be originated, 0 otherwise */
int ospf_redistribute_check(struct ospf *ospf, struct external_info *ei,
			    int *changed)
{
	struct route_map_set_values save_values;
	struct prefix_ipv4 *p = &ei->p;
	struct ospf_redist *red;
	uint8_t type = is_default_prefix4(&ei->p) ? DEFAULT_ROUTE : ei->type;
	unsigned short instance = is_default_prefix4(&ei->p) ? 0 : ei->instance;
	route_tag_t saved_tag = 0;

	/* Default is handled differently. */
	if (type == DEFAULT_ROUTE)
		return 1;

	if (changed)
		*changed = 0;

	if (!ospf_external_lsa_originate_check(ospf, ei))
		return 0;

	/* Take care connected route. */
	if (type == ZEBRA_ROUTE_CONNECT
	    && !ospf_distribute_check_connected(ospf, ei))
		return 0;

	if (!DEFAULT_ROUTE_TYPE(type) && DISTRIBUTE_NAME(ospf, type))
		/* distirbute-list exists, but access-list may not? */
		if (DISTRIBUTE_LIST(ospf, type))
			if (access_list_apply(DISTRIBUTE_LIST(ospf, type), p)
			    == FILTER_DENY) {
				if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
					zlog_debug(
						"Redistribute[%s]: %pFX filtered by distribute-list.",
						ospf_redist_string(type), p);
				return 0;
			}

	save_values = ei->route_map_set;
	ospf_reset_route_map_set_values(&ei->route_map_set);

	saved_tag = ei->tag;
	/* Resetting with original route tag */
	ei->tag = ei->orig_tag;

	/* apply route-map if needed */
	red = ospf_redist_lookup(ospf, type, instance);
	if (red && ROUTEMAP_NAME(red)) {
		route_map_result_t ret;

		ret = route_map_apply(ROUTEMAP(red), (struct prefix *)p, ei);

		if (ret == RMAP_DENYMATCH) {
			ei->route_map_set = save_values;
			if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
				zlog_debug(
					"Redistribute[%s]: %pFX filtered by route-map.",
					ospf_redist_string(type), p);
			return 0;
		}

		/* check if 'route-map set' changed something */
		if (changed) {
			*changed = !ospf_route_map_set_compare(
				&ei->route_map_set, &save_values);

			/* check if tag is modified */
			*changed |= (saved_tag != ei->tag);
		}
	}

	return 1;
}

/* OSPF route-map set for redistribution */
void ospf_routemap_set(struct ospf_redist *red, const char *name)
{
	if (ROUTEMAP_NAME(red)) {
		route_map_counter_decrement(ROUTEMAP(red));
		free(ROUTEMAP_NAME(red));
	}

	ROUTEMAP_NAME(red) = strdup(name);
	ROUTEMAP(red) = route_map_lookup_by_name(name);
	route_map_counter_increment(ROUTEMAP(red));
}

void ospf_routemap_unset(struct ospf_redist *red)
{
	if (ROUTEMAP_NAME(red)) {
		route_map_counter_decrement(ROUTEMAP(red));
		free(ROUTEMAP_NAME(red));
	}

	ROUTEMAP_NAME(red) = NULL;
	ROUTEMAP(red) = NULL;
}

static int ospf_zebra_gr_update(struct ospf *ospf, int command,
				uint32_t stale_time)
{
	struct zapi_cap api;

	if (!zclient || zclient->sock < 0 || !ospf)
		return 1;

	memset(&api, 0, sizeof(api));
	api.cap = command;
	api.stale_removal_time = stale_time;
	api.vrf_id = ospf->vrf_id;

	(void)zclient_capabilities_send(ZEBRA_CLIENT_CAPABILITIES, zclient,
					&api);

	return 0;
}

int ospf_zebra_gr_enable(struct ospf *ospf, uint32_t stale_time)
{
	return ospf_zebra_gr_update(ospf, ZEBRA_CLIENT_GR_CAPABILITIES,
				    stale_time);
}

int ospf_zebra_gr_disable(struct ospf *ospf)
{
	return ospf_zebra_gr_update(ospf, ZEBRA_CLIENT_GR_DISABLE, 0);
}

/* Zebra route add and delete treatment. */
static int ospf_zebra_read_route(ZAPI_CALLBACK_ARGS)
{
	struct zapi_route api;
	struct prefix_ipv4 p;
	struct prefix pgen;
	unsigned long ifindex;
	struct in_addr nexthop;
	struct external_info *ei;
	struct ospf *ospf;
	int i;
	uint8_t rt_type;

	ospf = ospf_lookup_by_vrf_id(vrf_id);
	if (ospf == NULL)
		return 0;

	if (zapi_route_decode(zclient->ibuf, &api) < 0)
		return -1;

	ifindex = api.nexthops[0].ifindex;
	nexthop = api.nexthops[0].gate.ipv4;
	rt_type = api.type;

	memcpy(&p, &api.prefix, sizeof(p));
	if (IPV4_NET127(ntohl(p.prefix.s_addr)))
		return 0;

	pgen.family = p.family;
	pgen.prefixlen = p.prefixlen;
	pgen.u.prefix4 = p.prefix;

	/* Re-destributed route is default route.
	 * Here, route type is used as 'ZEBRA_ROUTE_KERNEL' for
	 * updating ex-info. But in resetting (no default-info
	 * originate)ZEBRA_ROUTE_MAX is used to delete the ex-info.
	 * Resolved this inconsistency by maintaining same route type.
	 */
	if ((is_default_prefix(&pgen)) && (api.type != ZEBRA_ROUTE_OSPF))
		rt_type = DEFAULT_ROUTE;

	if (IS_DEBUG_OSPF(zebra, ZEBRA_REDISTRIBUTE))
		zlog_debug("%s: cmd %s from client %s: vrf_id %d, p %pFX",
			   __func__, zserv_command_string(cmd),
			   zebra_route_string(api.type), vrf_id, &api.prefix);

	if (cmd == ZEBRA_REDISTRIBUTE_ROUTE_ADD) {
		/* XXX|HACK|TODO|FIXME:
		 * Maybe we should ignore reject/blackhole routes? Testing
		 * shows that there is no problems though and this is only way
		 * to "summarize" routes in ASBR at the moment. Maybe we need
		 * just a better generalised solution for these types?
		 */

		/* Protocol tag overwrites all other tag value sent by zebra */
		if (ospf->dtag[rt_type] > 0)
			api.tag = ospf->dtag[rt_type];

		/*
		 * Given zebra sends update for a prefix via ADD message, it
		 * should
		 * be considered as an implicit DEL for that prefix with other
		 * source
		 * types.
		 */
		for (i = 0; i <= ZEBRA_ROUTE_MAX; i++)
			if (i != rt_type)
				ospf_external_info_delete(ospf, i, api.instance,
							  p);

		ei = ospf_external_info_add(ospf, rt_type, api.instance, p,
					    ifindex, nexthop, api.tag);
		if (ei == NULL) {
			/* Nothing has changed, so nothing to do; return */
			return 0;
		}
		if (ospf->router_id.s_addr != INADDR_ANY) {
			if (is_default_prefix4(&p))
				ospf_external_lsa_refresh_default(ospf);
			else {
				struct ospf_external_aggr_rt *aggr;
				struct as_external_lsa *al;
				struct ospf_lsa *lsa = NULL;
				struct in_addr mask;

				aggr = ospf_external_aggr_match(ospf, &ei->p);

				if (aggr) {
					/* Check the AS-external-LSA
					 * should be originated.
					 */
					if (!ospf_redistribute_check(ospf, ei,
								     NULL))
						return 0;

					if (IS_DEBUG_OSPF(lsa, EXTNL_LSA_AGGR))
						zlog_debug(
							"%s: Send Aggreate LSA (%pI4/%d)",
							__func__,
							&aggr->p.prefix,
							aggr->p.prefixlen);

					ospf_originate_summary_lsa(ospf, aggr,
								   ei);

					/* Handling the case where the
					 * external route prefix
					 * and aggegate prefix is same
					 * If same don't flush the
					 * originated
					 * external LSA.
					 */
					if (prefix_same(
						    (struct prefix *)&aggr->p,
						    (struct prefix *)&ei->p))
						return 0;

					lsa = ospf_external_info_find_lsa(
						ospf, &ei->p);

					if (lsa) {
						al = (struct as_external_lsa *)
							     lsa->data;
						masklen2ip(ei->p.prefixlen,
							   &mask);

						if (mask.s_addr
						    != al->mask.s_addr)
							return 0;

						ospf_external_lsa_flush(
							ospf, ei->type, &ei->p,
							0);
					}
				} else {
					struct ospf_lsa *current;

					current = ospf_external_info_find_lsa(
						ospf, &ei->p);
					if (!current) {
						/* Check the
						 * AS-external-LSA
						 * should be
						 * originated.
						 */
						if (!ospf_redistribute_check(
							    ospf, ei, NULL))
							return 0;

						ospf_external_lsa_originate(
							ospf, ei);
					} else {
						if (IS_DEBUG_OSPF(
							    zebra,
							    ZEBRA_REDISTRIBUTE))
							zlog_debug(
								"%s: %pI4 refreshing LSA",
								__func__,
								&p.prefix);
						ospf_external_lsa_refresh(
							ospf, current, ei,
							LSA_REFRESH_FORCE,
							false);
					}
				}
			}
		}

		/*
		 * Check if default-information originate is
		 * with some routemap prefix/access list match.
		 */
		ospf_external_lsa_default_routemap_apply(ospf, ei, cmd);

	} else { /* if (cmd == ZEBRA_REDISTRIBUTE_ROUTE_DEL) */
		struct ospf_external_aggr_rt *aggr;

		ei = ospf_external_info_lookup(ospf, rt_type, api.instance, &p);
		if (ei == NULL)
			return 0;

		/*
		 * Check if default-information originate i
		 * with some routemap prefix/access list match.
		 * Apply before ei is deleted.
		 */
		ospf_external_lsa_default_routemap_apply(ospf, ei, cmd);

		aggr = ospf_external_aggr_match(ospf, &ei->p);

		if (aggr && (ei->aggr_route == aggr)) {
			ospf_unlink_ei_from_aggr(ospf, aggr, ei);

			ospf_external_info_delete(ospf, rt_type, api.instance,
						  p);
		} else {
			ospf_external_info_delete(ospf, rt_type, api.instance,
						  p);

			if (is_default_prefix4(&p))
				ospf_external_lsa_refresh_default(ospf);
			else
				ospf_external_lsa_flush(ospf, rt_type, &p,
							ifindex /*, nexthop */);
		}
	}

	return 0;
}


int ospf_distribute_list_out_set(struct ospf *ospf, int type, const char *name)
{
	/* Lookup access-list for distribute-list. */
	DISTRIBUTE_LIST(ospf, type) = access_list_lookup(AFI_IP, name);

	/* Clear previous distribute-name. */
	if (DISTRIBUTE_NAME(ospf, type))
		free(DISTRIBUTE_NAME(ospf, type));

	/* Set distribute-name. */
	DISTRIBUTE_NAME(ospf, type) = strdup(name);

	/* If access-list have been set, schedule update timer. */
	if (DISTRIBUTE_LIST(ospf, type))
		ospf_distribute_list_update(ospf, type, 0);

	return CMD_SUCCESS;
}

int ospf_distribute_list_out_unset(struct ospf *ospf, int type,
				   const char *name)
{
	/* Schedule update timer. */
	if (DISTRIBUTE_LIST(ospf, type))
		ospf_distribute_list_update(ospf, type, 0);

	/* Unset distribute-list. */
	DISTRIBUTE_LIST(ospf, type) = NULL;

	/* Clear distribute-name. */
	if (DISTRIBUTE_NAME(ospf, type))
		free(DISTRIBUTE_NAME(ospf, type));

	DISTRIBUTE_NAME(ospf, type) = NULL;

	return CMD_SUCCESS;
}

/* distribute-list update timer. */
static void ospf_distribute_list_update_timer(struct thread *thread)
{
	struct route_node *rn;
	struct external_info *ei;
	struct route_table *rt;
	struct ospf_lsa *lsa;
	int type, default_refresh = 0;
	struct ospf *ospf = THREAD_ARG(thread);

	if (ospf == NULL)
		return;

	ospf->t_distribute_update = NULL;

	zlog_info("Zebra[Redistribute]: distribute-list update timer fired!");

	if (IS_DEBUG_OSPF_EVENT) {
		zlog_debug("%s: ospf distribute-list update vrf %s id %d",
			   __func__, ospf_vrf_id_to_name(ospf->vrf_id),
			   ospf->vrf_id);
	}

	/* foreach all external info. */
	for (type = 0; type <= ZEBRA_ROUTE_MAX; type++) {
		struct list *ext_list;
		struct listnode *node;
		struct ospf_external *ext;

		ext_list = ospf->external[type];
		if (!ext_list)
			continue;

		for (ALL_LIST_ELEMENTS_RO(ext_list, node, ext)) {
			rt = ext->external_info;
			if (!rt)
				continue;
			for (rn = route_top(rt); rn; rn = route_next(rn)) {
				ei = rn->info;
				if (!ei)
					continue;

				if (is_default_prefix4(&ei->p))
					default_refresh = 1;
				else {
					struct ospf_external_aggr_rt *aggr;

					aggr = ospf_external_aggr_match(ospf,
									&ei->p);
					if (aggr) {
						/* Check the
						 * AS-external-LSA
						 * should be originated.
						 */
						if (!ospf_redistribute_check(
							    ospf, ei, NULL)) {

							ospf_unlink_ei_from_aggr(
								ospf, aggr, ei);
							continue;
						}

						if (IS_DEBUG_OSPF(
							    lsa,
							    EXTNL_LSA_AGGR))
							zlog_debug(
								"%s: Send Aggregate LSA (%pI4/%d)",
								__func__,
								&aggr->p.prefix,
								aggr->p.prefixlen);

						/* Originate Aggregate
						 * LSA
						 */
						ospf_originate_summary_lsa(
							ospf, aggr, ei);
					} else if (
						(lsa = ospf_external_info_find_lsa(
							 ospf, &ei->p))) {
						int force =
							LSA_REFRESH_IF_CHANGED;
						/* If this is a MaxAge
						 * LSA, we need to
						 * force refresh it
						 * because distribute
						 * settings might have
						 * changed and now,
						 * this LSA needs to be
						 * originated, not be
						 * removed.
						 * If we don't force
						 * refresh it, it will
						 * remain a MaxAge LSA
						 * because it will look
						 * like it hasn't
						 * changed. Neighbors
						 * will not receive
						 * updates for this LSA.
						 */
						if (IS_LSA_MAXAGE(lsa))
							force = LSA_REFRESH_FORCE;

						ospf_external_lsa_refresh(
							ospf, lsa, ei, force,
							false);
					} else {
						if (!ospf_redistribute_check(
							    ospf, ei, NULL))
							continue;
						ospf_external_lsa_originate(
							ospf, ei);
					}
				}
			}
		}
	}
	if (default_refresh)
		ospf_external_lsa_refresh_default(ospf);
}

/* Update distribute-list and set timer to apply access-list. */
void ospf_distribute_list_update(struct ospf *ospf, int type,
				 unsigned short instance)
{
	struct ospf_external *ext;

	/* External info does not exist. */
	ext = ospf_external_lookup(ospf, type, instance);
	if (!ext || !EXTERNAL_INFO(ext))
		return;

	/* Set timer. If timer is already started, this call does nothing. */
	thread_add_timer_msec(master, ospf_distribute_list_update_timer, ospf,
			      ospf->min_ls_interval,
			      &ospf->t_distribute_update);
}

/* If access-list is updated, apply some check. */
static void ospf_filter_update(struct access_list *access)
{
	struct ospf *ospf;
	int type;
	int abr_inv = 0;
	struct ospf_area *area;
	struct listnode *node, *n1;

	/* If OSPF instance does not exist, return right now. */
	if (listcount(om->ospf) == 0)
		return;

	/* Iterate all ospf [VRF] instances */
	for (ALL_LIST_ELEMENTS_RO(om->ospf, n1, ospf)) {
		/* Update distribute-list, and apply filter. */
		for (type = 0; type <= ZEBRA_ROUTE_MAX; type++) {
			struct list *red_list;
			struct ospf_redist *red;

			red_list = ospf->redist[type];
			if (red_list)
				for (ALL_LIST_ELEMENTS_RO(red_list, node,
							  red)) {
					if (ROUTEMAP(red)) {
						/* if route-map is not NULL it
						 * may be
						 * using this access list */
						ospf_distribute_list_update(
							ospf, type,
							red->instance);
					}
				}

			/* There is place for route-map for default-information
			 * (ZEBRA_ROUTE_MAX),
			 * but no distribute list. */
			if (type == ZEBRA_ROUTE_MAX)
				break;

			if (DISTRIBUTE_NAME(ospf, type)) {
				/* Keep old access-list for distribute-list. */
				struct access_list *old =
					DISTRIBUTE_LIST(ospf, type);

				/* Update access-list for distribute-list. */
				DISTRIBUTE_LIST(ospf, type) =
					access_list_lookup(
						AFI_IP,
						DISTRIBUTE_NAME(ospf, type));

				/* No update for this distribute type. */
				if (old == NULL
				    && DISTRIBUTE_LIST(ospf, type) == NULL)
					continue;

				/* Schedule distribute-list update timer. */
				if (DISTRIBUTE_LIST(ospf, type) == NULL
				    || strcmp(DISTRIBUTE_NAME(ospf, type),
					      access->name)
					       == 0)
					ospf_distribute_list_update(ospf, type,
								    0);
			}
		}

		/* Update Area access-list. */
		for (ALL_LIST_ELEMENTS_RO(ospf->areas, node, area)) {
			if (EXPORT_NAME(area)) {
				EXPORT_LIST(area) = NULL;
				abr_inv++;
			}

			if (IMPORT_NAME(area)) {
				IMPORT_LIST(area) = NULL;
				abr_inv++;
			}
		}

		/* Schedule ABR tasks -- this will be changed -- takada. */
		if (IS_OSPF_ABR(ospf) && abr_inv)
			ospf_schedule_abr_task(ospf);
	}
}

/* If prefix-list is updated, do some updates. */
static void ospf_prefix_list_update(struct prefix_list *plist)
{
	struct ospf *ospf = NULL;
	int type;
	int abr_inv = 0;
	struct ospf_area *area;
	struct listnode *node, *n1;

	/* If OSPF instatnce does not exist, return right now. */
	if (listcount(om->ospf) == 0)
		return;

	/* Iterate all ospf [VRF] instances */
	for (ALL_LIST_ELEMENTS_RO(om->ospf, n1, ospf)) {

		/* Update all route-maps which are used
		 * as redistribution filters.
		 * They might use prefix-list.
		 */
		for (type = 0; type <= ZEBRA_ROUTE_MAX; type++) {
			struct list *red_list;
			struct ospf_redist *red;

			red_list = ospf->redist[type];
			if (!red_list)
				continue;

			for (ALL_LIST_ELEMENTS_RO(red_list, node, red)) {
				if (ROUTEMAP(red)) {
					/* if route-map is not NULL
					 * it may be using
					 * this prefix list */
					ospf_distribute_list_update(
						ospf, type, red->instance);
				}
			}
		}

		/* Update area filter-lists. */
		for (ALL_LIST_ELEMENTS_RO(ospf->areas, node, area)) {
			/* Update filter-list in. */
			if (PREFIX_NAME_IN(area)
			    && strcmp(PREFIX_NAME_IN(area),
				      prefix_list_name(plist))
				       == 0) {
				PREFIX_LIST_IN(area) = prefix_list_lookup(
					AFI_IP, PREFIX_NAME_IN(area));
				abr_inv++;
			}

			/* Update filter-list out. */
			if (PREFIX_NAME_OUT(area)
			    && strcmp(PREFIX_NAME_OUT(area),
				      prefix_list_name(plist))
				       == 0) {
				PREFIX_LIST_IN(area) = prefix_list_lookup(
					AFI_IP, PREFIX_NAME_OUT(area));
				abr_inv++;
			}
		}

		/* Schedule ABR task. */
		if (IS_OSPF_ABR(ospf) && abr_inv)
			ospf_schedule_abr_task(ospf);
	}
}

static struct ospf_distance *ospf_distance_new(void)
{
	return XCALLOC(MTYPE_OSPF_DISTANCE, sizeof(struct ospf_distance));
}

static void ospf_distance_free(struct ospf_distance *odistance)
{
	XFREE(MTYPE_OSPF_DISTANCE, odistance);
}

int ospf_distance_set(struct vty *vty, struct ospf *ospf,
		      const char *distance_str, const char *ip_str,
		      const char *access_list_str)
{
	int ret;
	struct prefix_ipv4 p;
	uint8_t distance;
	struct route_node *rn;
	struct ospf_distance *odistance;

	ret = str2prefix_ipv4(ip_str, &p);
	if (ret == 0) {
		vty_out(vty, "Malformed prefix\n");
		return CMD_WARNING_CONFIG_FAILED;
	}

	distance = atoi(distance_str);

	/* Get OSPF distance node. */
	rn = route_node_get(ospf->distance_table, (struct prefix *)&p);
	if (rn->info) {
		odistance = rn->info;
		route_unlock_node(rn);
	} else {
		odistance = ospf_distance_new();
		rn->info = odistance;
	}

	/* Set distance value. */
	odistance->distance = distance;

	/* Reset access-list configuration. */
	if (odistance->access_list) {
		free(odistance->access_list);
		odistance->access_list = NULL;
	}
	if (access_list_str)
		odistance->access_list = strdup(access_list_str);

	return CMD_SUCCESS;
}

int ospf_distance_unset(struct vty *vty, struct ospf *ospf,
			const char *distance_str, const char *ip_str,
			char const *access_list_str)
{
	int ret;
	struct prefix_ipv4 p;
	struct route_node *rn;
	struct ospf_distance *odistance;

	ret = str2prefix_ipv4(ip_str, &p);
	if (ret == 0) {
		vty_out(vty, "Malformed prefix\n");
		return CMD_WARNING_CONFIG_FAILED;
	}

	rn = route_node_lookup(ospf->distance_table, (struct prefix *)&p);
	if (!rn) {
		vty_out(vty, "Can't find specified prefix\n");
		return CMD_WARNING_CONFIG_FAILED;
	}

	odistance = rn->info;

	if (odistance->access_list)
		free(odistance->access_list);
	ospf_distance_free(odistance);

	rn->info = NULL;
	route_unlock_node(rn);
	route_unlock_node(rn);

	return CMD_SUCCESS;
}

void ospf_distance_reset(struct ospf *ospf)
{
	struct route_node *rn;
	struct ospf_distance *odistance;

	for (rn = route_top(ospf->distance_table); rn; rn = route_next(rn)) {
		odistance = rn->info;
		if (!odistance)
			continue;

		if (odistance->access_list)
			free(odistance->access_list);
		ospf_distance_free(odistance);
		rn->info = NULL;
		route_unlock_node(rn);
	}
}

uint8_t ospf_distance_apply(struct ospf *ospf, struct prefix_ipv4 *p,
			    struct ospf_route * or)
{

	if (ospf == NULL)
		return 0;

	if (ospf->distance_intra && or->path_type == OSPF_PATH_INTRA_AREA)
		return ospf->distance_intra;

	if (ospf->distance_inter && or->path_type == OSPF_PATH_INTER_AREA)
		return ospf->distance_inter;

	if (ospf->distance_external
	    && (or->path_type == OSPF_PATH_TYPE1_EXTERNAL ||
		or->path_type == OSPF_PATH_TYPE2_EXTERNAL))
		return ospf->distance_external;

	if (ospf->distance_all)
		return ospf->distance_all;

	return 0;
}

void ospf_zebra_vrf_register(struct ospf *ospf)
{
	if (!zclient || zclient->sock < 0 || !ospf)
		return;

	if (ospf->vrf_id != VRF_UNKNOWN) {
		if (IS_DEBUG_OSPF_EVENT)
			zlog_debug("%s: Register VRF %s id %u", __func__,
				   ospf_vrf_id_to_name(ospf->vrf_id),
				   ospf->vrf_id);
		zclient_send_reg_requests(zclient, ospf->vrf_id);
	}
}

void ospf_zebra_vrf_deregister(struct ospf *ospf)
{
	if (!zclient || zclient->sock < 0 || !ospf)
		return;

	if (ospf->vrf_id != VRF_DEFAULT && ospf->vrf_id != VRF_UNKNOWN) {
		if (IS_DEBUG_OSPF_EVENT)
			zlog_debug("%s: De-Register VRF %s id %u to Zebra.",
				   __func__, ospf_vrf_id_to_name(ospf->vrf_id),
				   ospf->vrf_id);
		/* Deregister for router-id, interfaces,
		 * redistributed routes. */
		zclient_send_dereg_requests(zclient, ospf->vrf_id);
	}
}

/* Label Manager Functions */

/**
 * Check if Label Manager is Ready or not.
 *
 * @return	True if Label Manager is ready, False otherwise
 */
bool ospf_zebra_label_manager_ready(void)
{
	return (zclient_sync->sock > 0);
}

/**
 * Request Label Range to the Label Manager.
 *
 * @param base		base label of the label range to request
 * @param chunk_size	size of the label range to request
 *
 * @return 	0 on success, -1 on failure
 */
int ospf_zebra_request_label_range(uint32_t base, uint32_t chunk_size)
{
	int ret;
	uint32_t start, end;

	if (zclient_sync->sock < 0)
		return -1;

	ret = lm_get_label_chunk(zclient_sync, 0, base, chunk_size, &start,
				 &end);
	if (ret < 0) {
		zlog_warn("%s: error getting label range!", __func__);
		return -1;
	}

	return 0;
}

/**
 * Release Label Range to the Label Manager.
 *
 * @param start		start of label range to release
 * @param end		end of label range to release
 *
 * @return		0 on success, -1 otherwise
 */
int ospf_zebra_release_label_range(uint32_t start, uint32_t end)
{
	int ret;

	if (zclient_sync->sock < 0)
		return -1;

	ret = lm_release_label_chunk(zclient_sync, start, end);
	if (ret < 0) {
		zlog_warn("%s: error releasing label range!", __func__);
		return -1;
	}

	return 0;
}

/**
 * Connect to the Label Manager.
 *
 * @return	0 on success, -1 otherwise
 */
int ospf_zebra_label_manager_connect(void)
{
	/* Connect to label manager. */
	if (zclient_socket_connect(zclient_sync) < 0) {
		zlog_warn("%s: failed connecting synchronous zclient!",
			  __func__);
		return -1;
	}
	/* make socket non-blocking */
	set_nonblocking(zclient_sync->sock);

	/* Send hello to notify zebra this is a synchronous client */
	if (zclient_send_hello(zclient_sync) == ZCLIENT_SEND_FAILURE) {
		zlog_warn("%s: failed sending hello for synchronous zclient!",
			  __func__);
		close(zclient_sync->sock);
		zclient_sync->sock = -1;
		return -1;
	}

	/* Connect to label manager */
	if (lm_label_manager_connect(zclient_sync, 0) != 0) {
		zlog_warn("%s: failed connecting to label manager!", __func__);
		if (zclient_sync->sock > 0) {
			close(zclient_sync->sock);
			zclient_sync->sock = -1;
		}
		return -1;
	}

	osr_debug("SR (%s): Successfully connected to the Label Manager",
		  __func__);

	return 0;
}

static void ospf_zebra_connected(struct zclient *zclient)
{
	/* Send the client registration */
	bfd_client_sendmsg(zclient, ZEBRA_BFD_CLIENT_REGISTER, VRF_DEFAULT);

	zclient_send_reg_requests(zclient, VRF_DEFAULT);
	zclient_register_opaque(zclient, ORR_IGP_METRIC_REGISTER);
}

/*
 * opaque messages between processes
 */
static int ospf_opaque_msg_handler(ZAPI_CALLBACK_ARGS)
{
	struct stream *s;
	struct zapi_opaque_msg info;
	struct ldp_igp_sync_if_state state;
	struct ldp_igp_sync_announce announce;
	struct zapi_opaque_reg_info dst;
	struct orr_igp_metric_reg orr_reg;
	int ret = 0;

	s = zclient->ibuf;

	if (zclient_opaque_decode(s, &info) != 0)
		return -1;

	switch (info.type) {
	case LINK_STATE_SYNC:
		STREAM_GETC(s, dst.proto);
		STREAM_GETW(s, dst.instance);
		STREAM_GETL(s, dst.session_id);
		dst.type = LINK_STATE_SYNC;
		ret = ospf_te_sync_ted(dst);
		break;
	case LDP_IGP_SYNC_IF_STATE_UPDATE:
		STREAM_GET(&state, s, sizeof(state));
		ret = ospf_ldp_sync_state_update(state);
		break;
	case LDP_IGP_SYNC_ANNOUNCE_UPDATE:
		STREAM_GET(&announce, s, sizeof(announce));
		ret = ospf_ldp_sync_announce_update(announce);
		break;
	case ORR_IGP_METRIC_REGISTER:
		STREAM_GET(&orr_reg, s, sizeof(orr_reg));
		ret = ospf_orr_igp_metric_register(orr_reg);
		break;
	default:
		break;
	}

stream_failure:

	return ret;
}

static int ospf_zebra_client_close_notify(ZAPI_CALLBACK_ARGS)
{
	int ret = 0;

	struct zapi_client_close_info info;

	if (zapi_client_close_notify_decode(zclient->ibuf, &info) < 0)
		return -1;

	ospf_ldp_sync_handle_client_close(&info);

	return ret;
}

static zclient_handler *const ospf_handlers[] = {
	[ZEBRA_ROUTER_ID_UPDATE] = ospf_router_id_update_zebra,
	[ZEBRA_INTERFACE_ADDRESS_ADD] = ospf_interface_address_add,
	[ZEBRA_INTERFACE_ADDRESS_DELETE] = ospf_interface_address_delete,
	[ZEBRA_INTERFACE_LINK_PARAMS] = ospf_interface_link_params,
	[ZEBRA_INTERFACE_VRF_UPDATE] = ospf_interface_vrf_update,

	[ZEBRA_REDISTRIBUTE_ROUTE_ADD] = ospf_zebra_read_route,
	[ZEBRA_REDISTRIBUTE_ROUTE_DEL] = ospf_zebra_read_route,

	[ZEBRA_OPAQUE_MESSAGE] = ospf_opaque_msg_handler,

	[ZEBRA_CLIENT_CLOSE_NOTIFY] = ospf_zebra_client_close_notify,
};

void ospf_zebra_init(struct thread_master *master, unsigned short instance)
{
	/* Allocate zebra structure. */
	zclient = zclient_new(master, &zclient_options_default, ospf_handlers,
			      array_size(ospf_handlers));
	zclient_init(zclient, ZEBRA_ROUTE_OSPF, instance, &ospfd_privs);
	zclient->zebra_connected = ospf_zebra_connected;

	/* Initialize special zclient for synchronous message exchanges. */
	struct zclient_options options = zclient_options_default;
	options.synchronous = true;
	zclient_sync = zclient_new(master, &options, NULL, 0);
	zclient_sync->sock = -1;
	zclient_sync->redist_default = ZEBRA_ROUTE_OSPF;
	zclient_sync->instance = instance;
	/*
	 * session_id must be different from default value (0) to distinguish
	 * the asynchronous socket from the synchronous one
	 */
	zclient_sync->session_id = 1;
	zclient_sync->privs = &ospfd_privs;

	access_list_add_hook(ospf_filter_update);
	access_list_delete_hook(ospf_filter_update);
	prefix_list_add_hook(ospf_prefix_list_update);
	prefix_list_delete_hook(ospf_prefix_list_update);
}

void ospf_zebra_send_arp(const struct interface *ifp, const struct prefix *p)
{
	zclient_send_neigh_discovery_req(zclient, ifp, p);
}