Merge pull request #2777 from qlyoung/fix-checkpatch-sh-greps

[mirror_frr.git] / ospfd / ospfd.c

/* OSPF version 2 daemon program.
 * Copyright (C) 1999, 2000 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 "vty.h"
#include "command.h"
#include "linklist.h"
#include "prefix.h"
#include "table.h"
#include "if.h"
#include "memory.h"
#include "stream.h"
#include "log.h"
#include "sockunion.h" /* for inet_aton () */
#include "zclient.h"
#include "routemap.h"
#include "plist.h"
#include "sockopt.h"
#include "bfd.h"
#include "libfrr.h"
#include "defaults.h"

#include "ospfd/ospfd.h"
#include "ospfd/ospf_network.h"
#include "ospfd/ospf_interface.h"
#include "ospfd/ospf_ism.h"
#include "ospfd/ospf_asbr.h"
#include "ospfd/ospf_lsa.h"
#include "ospfd/ospf_lsdb.h"
#include "ospfd/ospf_neighbor.h"
#include "ospfd/ospf_nsm.h"
#include "ospfd/ospf_spf.h"
#include "ospfd/ospf_packet.h"
#include "ospfd/ospf_dump.h"
#include "ospfd/ospf_zebra.h"
#include "ospfd/ospf_abr.h"
#include "ospfd/ospf_flood.h"
#include "ospfd/ospf_route.h"
#include "ospfd/ospf_ase.h"


DEFINE_QOBJ_TYPE(ospf)

/* OSPF process wide configuration. */
static struct ospf_master ospf_master;

/* OSPF process wide configuration pointer to export. */
struct ospf_master *om;

extern struct zclient *zclient;


static void ospf_remove_vls_through_area(struct ospf *, struct ospf_area *);
static void ospf_network_free(struct ospf *, struct ospf_network *);
static void ospf_area_free(struct ospf_area *);
static void ospf_network_run(struct prefix *, struct ospf_area *);
static void ospf_network_run_interface(struct ospf *, struct interface *,
                                       struct prefix *, struct ospf_area *);
static void ospf_network_run_subnet(struct ospf *, struct connected *,
                                    struct prefix *, struct ospf_area *);
static int ospf_network_match_iface(const struct connected *,
                                    const struct prefix *);
static void ospf_finish_final(struct ospf *);

#define OSPF_EXTERNAL_LSA_ORIGINATE_DELAY 1

void ospf_router_id_update(struct ospf *ospf)
{
        struct vrf *vrf = vrf_lookup_by_id(ospf->vrf_id);
        struct in_addr router_id, router_id_old;
        struct ospf_interface *oi;
        struct interface *ifp;
        struct listnode *node;
        int type;

        if (!ospf->oi_running) {
                if (IS_DEBUG_OSPF_EVENT)
                        zlog_debug(
                                "Router ospf not configured -- Router-ID update postponed");
                return;
        }

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("Router-ID[OLD:%s]: Update",
                           inet_ntoa(ospf->router_id));

        router_id_old = ospf->router_id;

        /* Select the router ID based on these priorities:
             1. Statically assigned router ID is always the first choice.
             2. If there is no statically assigned router ID, then try to stick
                with the most recent value, since changing router ID's is very
                disruptive.
             3. Last choice: just go with whatever the zebra daemon recommends.
        */
        if (ospf->router_id_static.s_addr != 0)
                router_id = ospf->router_id_static;
        else if (ospf->router_id.s_addr != 0)
                router_id = ospf->router_id;
        else
                router_id = ospf->router_id_zebra;

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("Router-ID[OLD:%s]: Update to %s",
                           inet_ntoa(ospf->router_id), inet_ntoa(router_id));

        if (!IPV4_ADDR_SAME(&router_id_old, &router_id)) {

                for (ALL_LIST_ELEMENTS_RO(ospf->oiflist, node, oi)) {
                        /* Some nbrs are identified by router_id, these needs
                         * to be rebuilt. Possible optimization would be to do
                         * oi->nbr_self->router_id = router_id for
                         * !(virtual | ptop) links
                         */
                        ospf_nbr_self_reset(oi, router_id);
                }

                /* If AS-external-LSA is queued, then flush those LSAs. */
                if (router_id_old.s_addr == 0 && ospf->external_origin) {
                        /* Originate each redistributed external route. */
                        for (type = 0; type < ZEBRA_ROUTE_MAX; type++)
                                if (ospf->external_origin & (1 << type))
                                        thread_add_event(
                                                master,
                                                ospf_external_lsa_originate_timer,
                                                ospf, type, NULL);
                        /* Originate Deafult. */
                        if (ospf->external_origin & (1 << ZEBRA_ROUTE_MAX))
                                thread_add_event(master,
                                                 ospf_default_originate_timer,
                                                 ospf, 0, NULL);

                        ospf->external_origin = 0;
                }

                /* Flush (inline) all external LSAs based on the OSPF_LSA_SELF
                 * flag */
                if (ospf->lsdb) {
                        struct route_node *rn;
                        struct ospf_lsa *lsa;

                        LSDB_LOOP (EXTERNAL_LSDB(ospf), rn, lsa)
                                if (IS_LSA_SELF(lsa))
                                        ospf_lsa_flush_schedule(ospf, lsa);
                }

                ospf->router_id = router_id;
                if (IS_DEBUG_OSPF_EVENT)
                        zlog_debug("Router-ID[NEW:%s]: Update",
                                   inet_ntoa(ospf->router_id));

                /* Flush (inline) all external LSAs which now match the new
                   router-id,
                   need to adjust the OSPF_LSA_SELF flag, so the flush doesnt
                   hit
                   asserts in ospf_refresher_unregister_lsa(). This step is
                   needed
                   because the current quagga code does look-up for
                   self-originated LSAs
                   based on the self router-id alone but expects OSPF_LSA_SELF
                   to be
                   properly set */
                if (ospf->lsdb) {
                        struct route_node *rn;
                        struct ospf_lsa *lsa;

                        LSDB_LOOP (EXTERNAL_LSDB(ospf), rn, lsa) {
                                /* AdvRouter and Router ID is the same. */
                                if (IPV4_ADDR_SAME(&lsa->data->adv_router,
                                                   &ospf->router_id)) {
                                        SET_FLAG(lsa->flags,
                                                 OSPF_LSA_SELF_CHECKED);
                                        SET_FLAG(lsa->flags, OSPF_LSA_SELF);
                                        ospf_lsa_flush_schedule(ospf, lsa);
                                }
                        }
                }

                /* Originate each redistributed external route. */
                for (type = 0; type < ZEBRA_ROUTE_MAX; type++)
                        thread_add_event(master,
                                         ospf_external_lsa_originate_timer,
                                         ospf, type, NULL);
                thread_add_event(master, ospf_default_originate_timer, ospf, 0,
                                 NULL);

                /* update router-lsa's for each area */
                ospf_router_lsa_update(ospf);

                /* update ospf_interface's */
                FOR_ALL_INTERFACES (vrf, ifp)
                        ospf_if_update(ospf, ifp);
        }
}

/* For OSPF area sort by area id. */
static int ospf_area_id_cmp(struct ospf_area *a1, struct ospf_area *a2)
{
        if (ntohl(a1->area_id.s_addr) > ntohl(a2->area_id.s_addr))
                return 1;
        if (ntohl(a1->area_id.s_addr) < ntohl(a2->area_id.s_addr))
                return -1;
        return 0;
}

/* Allocate new ospf structure. */
static struct ospf *ospf_new(unsigned short instance, const char *name)
{
        int i;
        struct vrf *vrf = NULL;

        struct ospf *new = XCALLOC(MTYPE_OSPF_TOP, sizeof(struct ospf));

        new->instance = instance;
        new->router_id.s_addr = htonl(0);
        new->router_id_static.s_addr = htonl(0);

        if (name) {
                new->vrf_id = VRF_UNKNOWN;
                /* Freed in ospf_finish_final */
                new->name = XSTRDUP(MTYPE_OSPF_TOP, name);
                vrf = vrf_lookup_by_name(new->name);
                if (IS_DEBUG_OSPF_EVENT)
                        zlog_debug(
                                "%s: Create new ospf instance with vrf_name %s vrf_id %u",
                                __PRETTY_FUNCTION__, name, new->vrf_id);
        } else {
                new->vrf_id = VRF_DEFAULT;
                vrf = vrf_lookup_by_id(VRF_DEFAULT);
        }

        if (vrf)
                ospf_vrf_link(new, vrf);

        ospf_zebra_vrf_register(new);

        new->abr_type = OSPF_ABR_DEFAULT;
        new->oiflist = list_new();
        new->vlinks = list_new();
        new->areas = list_new();
        new->areas->cmp = (int (*)(void *, void *))ospf_area_id_cmp;
        new->networks = route_table_init();
        new->nbr_nbma = route_table_init();

        new->lsdb = ospf_lsdb_new();

        new->default_originate = DEFAULT_ORIGINATE_NONE;

        new->passive_interface_default = OSPF_IF_ACTIVE;

        new->new_external_route = route_table_init();
        new->old_external_route = route_table_init();
        new->external_lsas = route_table_init();

        new->stub_router_startup_time = OSPF_STUB_ROUTER_UNCONFIGURED;
        new->stub_router_shutdown_time = OSPF_STUB_ROUTER_UNCONFIGURED;
        new->stub_router_admin_set = OSPF_STUB_ROUTER_ADMINISTRATIVE_UNSET;

        /* Distribute parameter init. */
        for (i = 0; i <= ZEBRA_ROUTE_MAX; i++) {
                new->dtag[i] = 0;
        }
        new->default_metric = -1;
        new->ref_bandwidth = OSPF_DEFAULT_REF_BANDWIDTH;

        /* LSA timers */
        new->min_ls_interval = OSPF_MIN_LS_INTERVAL;
        new->min_ls_arrival = OSPF_MIN_LS_ARRIVAL;

        /* SPF timer value init. */
        new->spf_delay = OSPF_SPF_DELAY_DEFAULT;
        new->spf_holdtime = OSPF_SPF_HOLDTIME_DEFAULT;
        new->spf_max_holdtime = OSPF_SPF_MAX_HOLDTIME_DEFAULT;
        new->spf_hold_multiplier = 1;

        /* MaxAge init. */
        new->maxage_delay = OSPF_LSA_MAXAGE_REMOVE_DELAY_DEFAULT;
        new->maxage_lsa = route_table_init();
        new->t_maxage_walker = NULL;
        thread_add_timer(master, ospf_lsa_maxage_walker, new,
                         OSPF_LSA_MAXAGE_CHECK_INTERVAL, &new->t_maxage_walker);

        /* Distance table init. */
        new->distance_table = route_table_init();

        new->lsa_refresh_queue.index = 0;
        new->lsa_refresh_interval = OSPF_LSA_REFRESH_INTERVAL_DEFAULT;
        new->t_lsa_refresher = NULL;
        thread_add_timer(master, ospf_lsa_refresh_walker, new,
                         new->lsa_refresh_interval, &new->t_lsa_refresher);
        new->lsa_refresher_started = monotime(NULL);

        if ((new->ibuf = stream_new(OSPF_MAX_PACKET_SIZE + 1)) == NULL) {
                zlog_err(
                        "ospf_new: fatal error: stream_new(%u) failed allocating ibuf",
                        OSPF_MAX_PACKET_SIZE + 1);
                exit(1);
        }
        new->t_read = NULL;
        new->oi_write_q = list_new();
        new->write_oi_count = OSPF_WRITE_INTERFACE_COUNT_DEFAULT;

/* Enable "log-adjacency-changes" */
#if DFLT_OSPF_LOG_ADJACENCY_CHANGES
        SET_FLAG(new->config, OSPF_LOG_ADJACENCY_CHANGES);
#endif

        QOBJ_REG(new, ospf);

        new->fd = -1;
        if ((ospf_sock_init(new)) < 0) {
                if (new->vrf_id != VRF_UNKNOWN)
                        zlog_warn(
                                "%s: ospf_sock_init is unable to open a socket",
                                __func__);
                return new;
        }
        thread_add_read(master, ospf_read, new, new->fd, &new->t_read);

        return new;
}

struct ospf *ospf_lookup_instance(unsigned short instance)
{
        struct ospf *ospf;
        struct listnode *node, *nnode;

        if (listcount(om->ospf) == 0)
                return NULL;

        for (ALL_LIST_ELEMENTS(om->ospf, node, nnode, ospf))
                if ((ospf->instance == 0 && instance == 0)
                    || (ospf->instance && instance
                        && ospf->instance == instance))
                        return ospf;

        return NULL;
}

static int ospf_is_ready(struct ospf *ospf)
{
        /* OSPF must be on and Router-ID must be configured. */
        if (!ospf || ospf->router_id.s_addr == 0)
                return 0;

        return 1;
}

static void ospf_add(struct ospf *ospf)
{
        listnode_add(om->ospf, ospf);
}

static void ospf_delete(struct ospf *ospf)
{
        listnode_delete(om->ospf, ospf);
}

struct ospf *ospf_lookup_by_inst_name(unsigned short instance, const char *name)
{
        struct ospf *ospf = NULL;
        struct listnode *node, *nnode;

        for (ALL_LIST_ELEMENTS(om->ospf, node, nnode, ospf)) {
                if ((ospf->instance == instance)
                    && ((ospf->name == NULL && name == NULL)
                        || (ospf->name && name
                            && strcmp(ospf->name, name) == 0)))
                        return ospf;
        }
        return NULL;
}

struct ospf *ospf_get(unsigned short instance, const char *name)
{
        struct ospf *ospf;

        /* vrf name provided call inst and name based api
         * in case of no name pass default ospf instance */
        if (name)
                ospf = ospf_lookup_by_inst_name(instance, name);
        else
                ospf = ospf_lookup_by_vrf_id(VRF_DEFAULT);

        if (ospf == NULL) {
                ospf = ospf_new(instance, name);
                ospf_add(ospf);

                if (ospf->router_id_static.s_addr == 0)
                        ospf_router_id_update(ospf);

                ospf_opaque_type11_lsa_init(ospf);
        }

        return ospf;
}

struct ospf *ospf_get_instance(unsigned short instance)
{
        struct ospf *ospf;

        ospf = ospf_lookup_instance(instance);
        if (ospf == NULL) {
                ospf = ospf_new(instance, NULL /* VRF_DEFAULT*/);
                ospf_add(ospf);

                if (ospf->router_id_static.s_addr == 0) {
                        if (vrf_lookup_by_id(ospf->vrf_id))
                                ospf_router_id_update(ospf);
                        else {
                                if (IS_DEBUG_OSPF_EVENT)
                                        zlog_debug(
                                                "%s: ospf VRF (id %d) is not active yet, skip router id update",
                                                __PRETTY_FUNCTION__,
                                                ospf->vrf_id);
                        }
                        ospf_router_id_update(ospf);
                }

                ospf_opaque_type11_lsa_init(ospf);
        }

        return ospf;
}

struct ospf *ospf_lookup_by_vrf_id(vrf_id_t vrf_id)
{
        struct vrf *vrf = NULL;

        vrf = vrf_lookup_by_id(vrf_id);
        if (!vrf)
                return NULL;
        return (vrf->info) ? (struct ospf *)vrf->info : NULL;
}

/* It should only be used when processing incoming info update from zebra.
 * Other situations, it is not sufficient to lookup the ospf instance by
 * vrf_name only without using the instance number.
 */
static struct ospf *ospf_lookup_by_name(const char *vrf_name)
{
        struct ospf *ospf = NULL;
        struct listnode *node, *nnode;

        for (ALL_LIST_ELEMENTS(om->ospf, node, nnode, ospf))
                if ((ospf->name == NULL && vrf_name == NULL)
                    || (ospf->name && vrf_name
                        && strcmp(ospf->name, vrf_name) == 0))
                        return ospf;
        return NULL;
}

/* Handle the second half of deferred shutdown. This is called either
 * from the deferred-shutdown timer thread, or directly through
 * ospf_deferred_shutdown_check.
 *
 * Function is to cleanup G-R state, if required then call ospf_finish_final
 * to complete shutdown of this ospf instance. Possibly exit if the
 * whole process is being shutdown and this was the last OSPF instance.
 */
static void ospf_deferred_shutdown_finish(struct ospf *ospf)
{
        ospf->stub_router_shutdown_time = OSPF_STUB_ROUTER_UNCONFIGURED;
        OSPF_TIMER_OFF(ospf->t_deferred_shutdown);

        ospf_finish_final(ospf);

        /* *ospf is now invalid */

        /* ospfd being shut-down? If so, was this the last ospf instance? */
        if (CHECK_FLAG(om->options, OSPF_MASTER_SHUTDOWN)
            && (listcount(om->ospf) == 0)) {
                exit(0);
        }

        return;
}

/* Timer thread for G-R */
static int ospf_deferred_shutdown_timer(struct thread *t)
{
        struct ospf *ospf = THREAD_ARG(t);

        ospf_deferred_shutdown_finish(ospf);

        return 0;
}

/* Check whether deferred-shutdown must be scheduled, otherwise call
 * down directly into second-half of instance shutdown.
 */
static void ospf_deferred_shutdown_check(struct ospf *ospf)
{
        unsigned long timeout;
        struct listnode *ln;
        struct ospf_area *area;

        /* deferred shutdown already running? */
        if (ospf->t_deferred_shutdown)
                return;

        /* Should we try push out max-metric LSAs? */
        if (ospf->stub_router_shutdown_time != OSPF_STUB_ROUTER_UNCONFIGURED) {
                for (ALL_LIST_ELEMENTS_RO(ospf->areas, ln, area)) {
                        SET_FLAG(area->stub_router_state,
                                 OSPF_AREA_ADMIN_STUB_ROUTED);

                        if (!CHECK_FLAG(area->stub_router_state,
                                        OSPF_AREA_IS_STUB_ROUTED))
                                ospf_router_lsa_update_area(area);
                }
                timeout = ospf->stub_router_shutdown_time;
        } else {
                /* No timer needed */
                ospf_deferred_shutdown_finish(ospf);
                return;
        }

        OSPF_TIMER_ON(ospf->t_deferred_shutdown, ospf_deferred_shutdown_timer,
                      timeout);
        return;
}

/* Shut down the entire process */
void ospf_terminate(void)
{
        struct ospf *ospf;
        struct listnode *node, *nnode;

        /* shutdown already in progress */
        if (CHECK_FLAG(om->options, OSPF_MASTER_SHUTDOWN))
                return;

        SET_FLAG(om->options, OSPF_MASTER_SHUTDOWN);

        /* exit immediately if OSPF not actually running */
        if (listcount(om->ospf) == 0)
                exit(0);

        bfd_gbl_exit();
        for (ALL_LIST_ELEMENTS(om->ospf, node, nnode, ospf))
                ospf_finish(ospf);

        /* Cleanup route maps */
        route_map_finish();

        /* reverse prefix_list_init */
        prefix_list_add_hook(NULL);
        prefix_list_delete_hook(NULL);
        prefix_list_reset();

        /* Cleanup vrf info */
        ospf_vrf_terminate();

        /* Deliberately go back up, hopefully to thread scheduler, as
         * One or more ospf_finish()'s may have deferred shutdown to a timer
         * thread
         */
        zclient_stop(zclient);
        zclient_free(zclient);

        frr_fini();
}

void ospf_finish(struct ospf *ospf)
{
        /* let deferred shutdown decide */
        ospf_deferred_shutdown_check(ospf);

        /* if ospf_deferred_shutdown returns, then ospf_finish_final is
         * deferred to expiry of G-S timer thread. Return back up, hopefully
         * to thread scheduler.
         */
        return;
}

/* Final cleanup of ospf instance */
static void ospf_finish_final(struct ospf *ospf)
{
        struct vrf *vrf = vrf_lookup_by_id(ospf->vrf_id);
        struct route_node *rn;
        struct ospf_nbr_nbma *nbr_nbma;
        struct ospf_lsa *lsa;
        struct interface *ifp;
        struct ospf_interface *oi;
        struct ospf_area *area;
        struct ospf_vl_data *vl_data;
        struct listnode *node, *nnode;
        int i;
        unsigned short instance = 0;

        QOBJ_UNREG(ospf);

        ospf_opaque_type11_lsa_term(ospf);

        ospf_opaque_finish();

        ospf_flush_self_originated_lsas_now(ospf);

        /* Unregister redistribution */
        for (i = 0; i < ZEBRA_ROUTE_MAX; i++) {
                struct list *red_list;
                struct ospf_redist *red;

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

                for (ALL_LIST_ELEMENTS(red_list, node, nnode, red))
                        ospf_redistribute_unset(ospf, i, red->instance);
        }
        ospf_redistribute_default_unset(ospf);

        for (ALL_LIST_ELEMENTS(ospf->areas, node, nnode, area))
                ospf_remove_vls_through_area(ospf, area);

        for (ALL_LIST_ELEMENTS(ospf->vlinks, node, nnode, vl_data))
                ospf_vl_delete(ospf, vl_data);

        list_delete_and_null(&ospf->vlinks);

        /* Remove any ospf interface config params */
        FOR_ALL_INTERFACES (vrf, ifp) {
                struct ospf_if_params *params;

                params = IF_DEF_PARAMS(ifp);
                if (OSPF_IF_PARAM_CONFIGURED(params, if_area))
                        UNSET_IF_PARAM(params, if_area);
        }

        /* Reset interface. */
        for (ALL_LIST_ELEMENTS(ospf->oiflist, node, nnode, oi))
                ospf_if_free(oi);
        list_delete_and_null(&ospf->oiflist);

        /* De-Register VRF */
        ospf_zebra_vrf_deregister(ospf);

        /* Clear static neighbors */
        for (rn = route_top(ospf->nbr_nbma); rn; rn = route_next(rn))
                if ((nbr_nbma = rn->info)) {
                        OSPF_POLL_TIMER_OFF(nbr_nbma->t_poll);

                        if (nbr_nbma->nbr) {
                                nbr_nbma->nbr->nbr_nbma = NULL;
                                nbr_nbma->nbr = NULL;
                        }

                        if (nbr_nbma->oi) {
                                listnode_delete(nbr_nbma->oi->nbr_nbma,
                                                nbr_nbma);
                                nbr_nbma->oi = NULL;
                        }

                        XFREE(MTYPE_OSPF_NEIGHBOR_STATIC, nbr_nbma);
                }

        route_table_finish(ospf->nbr_nbma);

        /* Clear networks and Areas. */
        for (rn = route_top(ospf->networks); rn; rn = route_next(rn)) {
                struct ospf_network *network;

                if ((network = rn->info) != NULL) {
                        ospf_network_free(ospf, network);
                        rn->info = NULL;
                        route_unlock_node(rn);
                }
        }
        route_table_finish(ospf->networks);

        for (ALL_LIST_ELEMENTS(ospf->areas, node, nnode, area)) {
                listnode_delete(ospf->areas, area);
                ospf_area_free(area);
        }

        /* Cancel all timers. */
        OSPF_TIMER_OFF(ospf->t_external_lsa);
        OSPF_TIMER_OFF(ospf->t_spf_calc);
        OSPF_TIMER_OFF(ospf->t_ase_calc);
        OSPF_TIMER_OFF(ospf->t_maxage);
        OSPF_TIMER_OFF(ospf->t_maxage_walker);
        OSPF_TIMER_OFF(ospf->t_abr_task);
        OSPF_TIMER_OFF(ospf->t_asbr_check);
        OSPF_TIMER_OFF(ospf->t_distribute_update);
        OSPF_TIMER_OFF(ospf->t_lsa_refresher);
        OSPF_TIMER_OFF(ospf->t_read);
        OSPF_TIMER_OFF(ospf->t_write);
        OSPF_TIMER_OFF(ospf->t_opaque_lsa_self);
        OSPF_TIMER_OFF(ospf->t_sr_update);

        close(ospf->fd);
        stream_free(ospf->ibuf);

        LSDB_LOOP (OPAQUE_AS_LSDB(ospf), rn, lsa)
                ospf_discard_from_db(ospf, ospf->lsdb, lsa);
        LSDB_LOOP (EXTERNAL_LSDB(ospf), rn, lsa)
                ospf_discard_from_db(ospf, ospf->lsdb, lsa);

        ospf_lsdb_delete_all(ospf->lsdb);
        ospf_lsdb_free(ospf->lsdb);

        for (rn = route_top(ospf->maxage_lsa); rn; rn = route_next(rn)) {
                struct ospf_lsa *lsa;

                if ((lsa = rn->info) != NULL) {
                        ospf_lsa_unlock(&lsa);
                        rn->info = NULL;
                }
                route_unlock_node(rn);
        }
        route_table_finish(ospf->maxage_lsa);

        if (ospf->old_table)
                ospf_route_table_free(ospf->old_table);
        if (ospf->new_table) {
                ospf_route_delete(ospf, ospf->new_table);
                ospf_route_table_free(ospf->new_table);
        }
        if (ospf->old_rtrs)
                ospf_rtrs_free(ospf->old_rtrs);
        if (ospf->new_rtrs)
                ospf_rtrs_free(ospf->new_rtrs);
        if (ospf->new_external_route) {
                ospf_route_delete(ospf, ospf->new_external_route);
                ospf_route_table_free(ospf->new_external_route);
        }
        if (ospf->old_external_route) {
                ospf_route_delete(ospf, ospf->old_external_route);
                ospf_route_table_free(ospf->old_external_route);
        }
        if (ospf->external_lsas) {
                ospf_ase_external_lsas_finish(ospf->external_lsas);
        }

        list_delete_and_null(&ospf->areas);
        list_delete_and_null(&ospf->oi_write_q);

        for (i = ZEBRA_ROUTE_SYSTEM; i <= ZEBRA_ROUTE_MAX; i++) {
                struct list *ext_list;
                struct listnode *node;
                struct ospf_external *ext;

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

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

                                        XFREE(MTYPE_OSPF_EXTERNAL_INFO,
                                              rn->info);
                                        rn->info = NULL;
                                        route_unlock_node(rn);
                                }
                }
        }

        ospf_distance_reset(ospf);
        route_table_finish(ospf->distance_table);

        if (!CHECK_FLAG(om->options, OSPF_MASTER_SHUTDOWN))
                instance = ospf->instance;

        ospf_delete(ospf);

        if (ospf->name) {
                vrf = vrf_lookup_by_name(ospf->name);
                if (vrf)
                        ospf_vrf_unlink(ospf, vrf);
                XFREE(MTYPE_OSPF_TOP, ospf->name);
        } else {
                vrf = vrf_lookup_by_id(VRF_DEFAULT);
                if (vrf)
                        ospf_vrf_unlink(ospf, vrf);
        }

        XFREE(MTYPE_OSPF_TOP, ospf);

        if (!CHECK_FLAG(om->options, OSPF_MASTER_SHUTDOWN))
                ospf_get_instance(instance);
}


/* allocate new OSPF Area object */
static struct ospf_area *ospf_area_new(struct ospf *ospf,
                                       struct in_addr area_id)
{
        struct ospf_area *new;

        /* Allocate new config_network. */
        new = XCALLOC(MTYPE_OSPF_AREA, sizeof(struct ospf_area));

        new->ospf = ospf;

        new->area_id = area_id;
        new->area_id_fmt = OSPF_AREA_ID_FMT_DOTTEDQUAD;

        new->external_routing = OSPF_AREA_DEFAULT;
        new->default_cost = 1;
        new->auth_type = OSPF_AUTH_NULL;

        /* New LSDB init. */
        new->lsdb = ospf_lsdb_new();

        /* Self-originated LSAs initialize. */
        new->router_lsa_self = NULL;

        ospf_opaque_type10_lsa_init(new);

        new->oiflist = list_new();
        new->ranges = route_table_init();

        if (area_id.s_addr == OSPF_AREA_BACKBONE)
                ospf->backbone = new;

        return new;
}

static void ospf_area_free(struct ospf_area *area)
{
        struct route_node *rn;
        struct ospf_lsa *lsa;

        ospf_opaque_type10_lsa_term(area);

        /* Free LSDBs. */
        LSDB_LOOP (ROUTER_LSDB(area), rn, lsa)
                ospf_discard_from_db(area->ospf, area->lsdb, lsa);
        LSDB_LOOP (NETWORK_LSDB(area), rn, lsa)
                ospf_discard_from_db(area->ospf, area->lsdb, lsa);
        LSDB_LOOP (SUMMARY_LSDB(area), rn, lsa)
                ospf_discard_from_db(area->ospf, area->lsdb, lsa);
        LSDB_LOOP (ASBR_SUMMARY_LSDB(area), rn, lsa)
                ospf_discard_from_db(area->ospf, area->lsdb, lsa);

        LSDB_LOOP (NSSA_LSDB(area), rn, lsa)
                ospf_discard_from_db(area->ospf, area->lsdb, lsa);
        LSDB_LOOP (OPAQUE_AREA_LSDB(area), rn, lsa)
                ospf_discard_from_db(area->ospf, area->lsdb, lsa);
        LSDB_LOOP (OPAQUE_LINK_LSDB(area), rn, lsa)
                ospf_discard_from_db(area->ospf, area->lsdb, lsa);

        ospf_lsdb_delete_all(area->lsdb);
        ospf_lsdb_free(area->lsdb);

        ospf_lsa_unlock(&area->router_lsa_self);

        route_table_finish(area->ranges);
        list_delete_and_null(&area->oiflist);

        if (EXPORT_NAME(area))
                free(EXPORT_NAME(area));

        if (IMPORT_NAME(area))
                free(IMPORT_NAME(area));

        /* Cancel timer. */
        OSPF_TIMER_OFF(area->t_stub_router);
        OSPF_TIMER_OFF(area->t_opaque_lsa_self);

        if (OSPF_IS_AREA_BACKBONE(area))
                area->ospf->backbone = NULL;

        XFREE(MTYPE_OSPF_AREA, area);
}

void ospf_area_check_free(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_lookup_by_area_id(ospf, area_id);
        if (area && listcount(area->oiflist) == 0 && area->ranges->top == NULL
            && area->shortcut_configured == OSPF_SHORTCUT_DEFAULT
            && area->external_routing == OSPF_AREA_DEFAULT
            && area->no_summary == 0 && area->default_cost == 1
            && EXPORT_NAME(area) == NULL && IMPORT_NAME(area) == NULL
            && area->auth_type == OSPF_AUTH_NULL) {
                listnode_delete(ospf->areas, area);
                ospf_area_free(area);
        }
}

struct ospf_area *ospf_area_get(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_lookup_by_area_id(ospf, area_id);
        if (!area) {
                area = ospf_area_new(ospf, area_id);
                listnode_add_sort(ospf->areas, area);
                ospf_check_abr_status(ospf);
                if (ospf->stub_router_admin_set
                    == OSPF_STUB_ROUTER_ADMINISTRATIVE_SET) {
                        SET_FLAG(area->stub_router_state,
                                 OSPF_AREA_ADMIN_STUB_ROUTED);
                }
        }

        return area;
}

struct ospf_area *ospf_area_lookup_by_area_id(struct ospf *ospf,
                                              struct in_addr area_id)
{
        struct ospf_area *area;
        struct listnode *node;

        for (ALL_LIST_ELEMENTS_RO(ospf->areas, node, area))
                if (IPV4_ADDR_SAME(&area->area_id, &area_id))
                        return area;

        return NULL;
}

void ospf_area_add_if(struct ospf_area *area, struct ospf_interface *oi)
{
        listnode_add(area->oiflist, oi);
}

void ospf_area_del_if(struct ospf_area *area, struct ospf_interface *oi)
{
        listnode_delete(area->oiflist, oi);
}


static void add_ospf_interface(struct connected *co, struct ospf_area *area)
{
        struct ospf_interface *oi;

        oi = ospf_if_new(area->ospf, co->ifp, co->address);
        oi->connected = co;

        oi->area = area;

        oi->params = ospf_lookup_if_params(co->ifp, oi->address->u.prefix4);
        oi->output_cost = ospf_if_get_output_cost(oi);

        /* Relate ospf interface to ospf instance. */
        oi->ospf = area->ospf;

        /* update network type as interface flag */
        /* If network type is specified previously,
           skip network type setting. */
        oi->type = IF_DEF_PARAMS(co->ifp)->type;

        /* Add pseudo neighbor. */
        ospf_nbr_self_reset(oi, oi->ospf->router_id);

        ospf_area_add_if(oi->area, oi);

        /*
         * if router_id is not configured, dont bring up
         * interfaces.
         * ospf_router_id_update() will call ospf_if_update
         * whenever r-id is configured instead.
         */
        if ((area->ospf->router_id.s_addr != 0) && if_is_operative(co->ifp))
                ospf_if_up(oi);
}

static void update_redistributed(struct ospf *ospf, int add_to_ospf)
{
        struct route_node *rn;
        struct external_info *ei;
        struct ospf_external *ext;

        if (ospf_is_type_redistributed(ospf, ZEBRA_ROUTE_CONNECT, 0)) {
                ext = ospf_external_lookup(ospf, ZEBRA_ROUTE_CONNECT, 0);
                if ((ext) && EXTERNAL_INFO(ext)) {
                        for (rn = route_top(EXTERNAL_INFO(ext)); rn;
                             rn = route_next(rn)) {
                                ei = rn->info;
                                if (ei == NULL)
                                        continue;

                                if (add_to_ospf) {
                                        if (ospf_external_info_find_lsa(ospf,
                                                                        &ei->p))
                                                if (!ospf_distribute_check_connected(
                                                            ospf, ei))
                                                        ospf_external_lsa_flush(
                                                                ospf, ei->type,
                                                                &ei->p,
                                                                ei->ifindex /*, ei->nexthop */);
                                } else {
                                        if (!ospf_external_info_find_lsa(
                                                    ospf, &ei->p))
                                                if (ospf_distribute_check_connected(
                                                            ospf, ei))
                                                        ospf_external_lsa_originate(
                                                                ospf, ei);
                                }
                        }
                }
        }
}

/* Config network statement related functions. */
static struct ospf_network *ospf_network_new(struct in_addr area_id)
{
        struct ospf_network *new;
        new = XCALLOC(MTYPE_OSPF_NETWORK, sizeof(struct ospf_network));

        new->area_id = area_id;
        new->area_id_fmt = OSPF_AREA_ID_FMT_DOTTEDQUAD;

        return new;
}

static void ospf_network_free(struct ospf *ospf, struct ospf_network *network)
{
        ospf_area_check_free(ospf, network->area_id);
        ospf_schedule_abr_task(ospf);
        XFREE(MTYPE_OSPF_NETWORK, network);
}

int ospf_network_set(struct ospf *ospf, struct prefix_ipv4 *p,
                     struct in_addr area_id, int df)
{
        struct ospf_network *network;
        struct ospf_area *area;
        struct route_node *rn;

        rn = route_node_get(ospf->networks, (struct prefix *)p);
        if (rn->info) {
                network = rn->info;
                route_unlock_node(rn);

                if (IPV4_ADDR_SAME(&area_id, &network->area_id)) {
                        return 1;
                } else {
                        /* There is already same network statement. */
                        return 0;
                }
        }

        rn->info = network = ospf_network_new(area_id);
        network->area_id_fmt = df;
        area = ospf_area_get(ospf, area_id);
        ospf_area_display_format_set(ospf, area, df);

        /* Run network config now. */
        ospf_network_run((struct prefix *)p, area);

        /* Update connected redistribute. */
        update_redistributed(ospf, 1); /* interfaces possibly added */

        ospf_area_check_free(ospf, area_id);

        return 1;
}

int ospf_network_unset(struct ospf *ospf, struct prefix_ipv4 *p,
                       struct in_addr area_id)
{
        struct route_node *rn;
        struct ospf_network *network;
        struct listnode *node, *nnode;
        struct ospf_interface *oi;

        rn = route_node_lookup(ospf->networks, (struct prefix *)p);
        if (rn == NULL)
                return 0;

        network = rn->info;
        route_unlock_node(rn);
        if (!IPV4_ADDR_SAME(&area_id, &network->area_id))
                return 0;

        ospf_network_free(ospf, rn->info);
        rn->info = NULL;
        route_unlock_node(rn); /* initial reference */

        /* Find interfaces that are not configured already.  */
        for (ALL_LIST_ELEMENTS(ospf->oiflist, node, nnode, oi)) {

                if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
                        continue;

                ospf_network_run_subnet(ospf, oi->connected, NULL, NULL);
        }

        /* Update connected redistribute. */
        update_redistributed(ospf, 0); /* interfaces possibly removed */
        ospf_area_check_free(ospf, area_id);

        return 1;
}

/* Ensure there's an OSPF instance, as "ip ospf area" enabled OSPF means
 * there might not be any 'router ospf' config.
 *
 * Otherwise, doesn't do anything different to ospf_if_update for now
 */
void ospf_interface_area_set(struct ospf *ospf, struct interface *ifp)
{
        if (!ospf)
                return;

        ospf_if_update(ospf, ifp);
        /* if_update does a update_redistributed */

        return;
}

void ospf_interface_area_unset(struct ospf *ospf, struct interface *ifp)
{
        struct route_node *rn_oi;

        if (!ospf)
                return; /* Ospf not ready yet */

        /* Find interfaces that may need to be removed. */
        for (rn_oi = route_top(IF_OIFS(ifp)); rn_oi;
             rn_oi = route_next(rn_oi)) {
                struct ospf_interface *oi = NULL;

                if ((oi = rn_oi->info) == NULL)
                        continue;

                if (oi->type == OSPF_IFTYPE_VIRTUALLINK)
                        continue;

                ospf_network_run_subnet(ospf, oi->connected, NULL, NULL);
        }

        /* Update connected redistribute. */
        update_redistributed(ospf, 0); /* interfaces possibly removed */
}

/* Check whether interface matches given network
 * returns: 1, true. 0, false
 */
static int ospf_network_match_iface(const struct connected *co,
                                    const struct prefix *net)
{
        /* new approach: more elegant and conceptually clean */
        return prefix_match_network_statement(net, CONNECTED_PREFIX(co));
}

static void ospf_update_interface_area(struct connected *co,
                                       struct ospf_area *area)
{
        struct ospf_interface *oi = ospf_if_table_lookup(co->ifp, co->address);

        /* nothing to be done case */
        if (oi && oi->area == area) {
                return;
        }

        if (oi)
                ospf_if_free(oi);

        add_ospf_interface(co, area);
}

/* Run OSPF for the given subnet, taking into account the following
 * possible sources of area configuration, in the given order of preference:
 *
 * - Whether there is interface+address specific area configuration
 * - Whether there is a default area for the interface
 * - Whether there is an area given as a parameter.
 * - If no specific network prefix/area is supplied, whether there's
 *   a matching network configured.
 */
static void ospf_network_run_subnet(struct ospf *ospf, struct connected *co,
                                    struct prefix *p,
                                    struct ospf_area *given_area)
{
        struct ospf_interface *oi;
        struct ospf_if_params *params;
        struct ospf_area *area = NULL;
        struct route_node *rn;
        int configed = 0;

        if (CHECK_FLAG(co->flags, ZEBRA_IFA_SECONDARY))
                return;

        if (co->address->family != AF_INET)
                return;

        /* Try determine the appropriate area for this interface + address
         * Start by checking interface config
         */
        params = ospf_lookup_if_params(co->ifp, co->address->u.prefix4);
        if (params && OSPF_IF_PARAM_CONFIGURED(params, if_area))
                area = ospf_area_get(ospf, params->if_area);
        else {
                params = IF_DEF_PARAMS(co->ifp);
                if (OSPF_IF_PARAM_CONFIGURED(params, if_area))
                        area = ospf_area_get(ospf, params->if_area);
        }

        /* If we've found an interface and/or addr specific area, then we're
         * done
         */
        if (area) {
                ospf_update_interface_area(co, area);
                return;
        }

        /* Otherwise, only remaining possibility is a matching network statement
         */
        if (p) {
                assert(given_area != NULL);

                /* Which either was supplied as a parameter.. (e.g. cause a new
                 * network/area was just added)..
                 */
                if (p->family == co->address->family
                    && ospf_network_match_iface(co, p))
                        ospf_update_interface_area(co, given_area);

                return;
        }

        /* Else we have to search the existing network/area config to see
         * if any match..
         */
        for (rn = route_top(ospf->networks); rn; rn = route_next(rn))
                if (rn->info != NULL && ospf_network_match_iface(co, &rn->p)) {
                        struct ospf_network *network =
                                (struct ospf_network *)rn->info;
                        area = ospf_area_get(ospf, network->area_id);
                        ospf_update_interface_area(co, area);
                        configed = 1;
                }

        /* If the subnet isn't in any area, deconfigure */
        if (!configed && (oi = ospf_if_table_lookup(co->ifp, co->address)))
                ospf_if_free(oi);
}

static void ospf_network_run_interface(struct ospf *ospf, struct interface *ifp,
                                       struct prefix *p,
                                       struct ospf_area *given_area)
{
        struct listnode *cnode;
        struct connected *co;

        if (memcmp(ifp->name, "VLINK", 5) == 0)
                return;

        /* Network prefix without area is nonsensical */
        if (p)
                assert(given_area != NULL);

        /* if interface prefix is match specified prefix,
           then create socket and join multicast group. */
        for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, co))
                ospf_network_run_subnet(ospf, co, p, given_area);
}

static void ospf_network_run(struct prefix *p, struct ospf_area *area)
{
        struct vrf *vrf = vrf_lookup_by_id(area->ospf->vrf_id);
        struct interface *ifp;

        /* Schedule Router ID Update. */
        if (area->ospf->router_id.s_addr == 0)
                ospf_router_id_update(area->ospf);

        /* Get target interface. */
        FOR_ALL_INTERFACES (vrf, ifp)
                ospf_network_run_interface(area->ospf, ifp, p, area);
}

void ospf_ls_upd_queue_empty(struct ospf_interface *oi)
{
        struct route_node *rn;
        struct listnode *node, *nnode;
        struct list *lst;
        struct ospf_lsa *lsa;

        /* empty ls update queue */
        for (rn = route_top(oi->ls_upd_queue); rn; rn = route_next(rn))
                if ((lst = (struct list *)rn->info)) {
                        for (ALL_LIST_ELEMENTS(lst, node, nnode, lsa))
                                ospf_lsa_unlock(&lsa); /* oi->ls_upd_queue */
                        list_delete_and_null(&lst);
                        rn->info = NULL;
                }

        /* remove update event */
        if (oi->t_ls_upd_event) {
                thread_cancel(oi->t_ls_upd_event);
                oi->t_ls_upd_event = NULL;
        }
}

void ospf_if_update(struct ospf *ospf, struct interface *ifp)
{

        if (!ospf)
                return;

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug(
                        "%s: interface %s ifp->vrf_id %u ospf vrf %s vrf_id %u router_id %s",
                        __PRETTY_FUNCTION__, ifp->name, ifp->vrf_id,
                        ospf_vrf_id_to_name(ospf->vrf_id), ospf->vrf_id,
                        inet_ntoa(ospf->router_id));

        /* OSPF must be ready. */
        if (!ospf_is_ready(ospf))
                return;

        ospf_network_run_interface(ospf, ifp, NULL, NULL);

        /* Update connected redistribute. */
        update_redistributed(ospf, 1);
}

void ospf_remove_vls_through_area(struct ospf *ospf, struct ospf_area *area)
{
        struct listnode *node, *nnode;
        struct ospf_vl_data *vl_data;

        for (ALL_LIST_ELEMENTS(ospf->vlinks, node, nnode, vl_data))
                if (IPV4_ADDR_SAME(&vl_data->vl_area_id, &area->area_id))
                        ospf_vl_delete(ospf, vl_data);
}


static const struct message ospf_area_type_msg[] = {
        {OSPF_AREA_DEFAULT, "Default"},
        {OSPF_AREA_STUB, "Stub"},
        {OSPF_AREA_NSSA, "NSSA"},
        {0}};

static void ospf_area_type_set(struct ospf_area *area, int type)
{
        struct listnode *node;
        struct ospf_interface *oi;

        if (area->external_routing == type) {
                if (IS_DEBUG_OSPF_EVENT)
                        zlog_debug("Area[%s]: Types are the same, ignored.",
                                   inet_ntoa(area->area_id));
                return;
        }

        area->external_routing = type;

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("Area[%s]: Configured as %s",
                           inet_ntoa(area->area_id),
                           lookup_msg(ospf_area_type_msg, type, NULL));

        switch (area->external_routing) {
        case OSPF_AREA_DEFAULT:
                for (ALL_LIST_ELEMENTS_RO(area->oiflist, node, oi))
                        if (oi->nbr_self != NULL) {
                                UNSET_FLAG(oi->nbr_self->options,
                                           OSPF_OPTION_NP);
                                SET_FLAG(oi->nbr_self->options, OSPF_OPTION_E);
                        }
                break;
        case OSPF_AREA_STUB:
                for (ALL_LIST_ELEMENTS_RO(area->oiflist, node, oi))
                        if (oi->nbr_self != NULL) {
                                if (IS_DEBUG_OSPF_EVENT)
                                        zlog_debug(
                                                "setting options on %s accordingly",
                                                IF_NAME(oi));
                                UNSET_FLAG(oi->nbr_self->options,
                                           OSPF_OPTION_NP);
                                UNSET_FLAG(oi->nbr_self->options,
                                           OSPF_OPTION_E);
                                if (IS_DEBUG_OSPF_EVENT)
                                        zlog_debug("options set on %s: %x",
                                                   IF_NAME(oi), OPTIONS(oi));
                        }
                break;
        case OSPF_AREA_NSSA:
                for (ALL_LIST_ELEMENTS_RO(area->oiflist, node, oi))
                        if (oi->nbr_self != NULL) {
                                zlog_debug(
                                        "setting nssa options on %s accordingly",
                                        IF_NAME(oi));
                                UNSET_FLAG(oi->nbr_self->options,
                                           OSPF_OPTION_E);
                                SET_FLAG(oi->nbr_self->options, OSPF_OPTION_NP);
                                zlog_debug("options set on %s: %x", IF_NAME(oi),
                                           OPTIONS(oi));
                        }
                break;
        default:
                break;
        }

        ospf_router_lsa_update_area(area);
        ospf_schedule_abr_task(area->ospf);
}

int ospf_area_shortcut_set(struct ospf *ospf, struct ospf_area *area, int mode)
{
        if (area->shortcut_configured == mode)
                return 0;

        area->shortcut_configured = mode;
        ospf_router_lsa_update_area(area);
        ospf_schedule_abr_task(ospf);

        ospf_area_check_free(ospf, area->area_id);

        return 1;
}

int ospf_area_shortcut_unset(struct ospf *ospf, struct ospf_area *area)
{
        area->shortcut_configured = OSPF_SHORTCUT_DEFAULT;
        ospf_router_lsa_update_area(area);
        ospf_area_check_free(ospf, area->area_id);
        ospf_schedule_abr_task(ospf);

        return 1;
}

static int ospf_area_vlink_count(struct ospf *ospf, struct ospf_area *area)
{
        struct ospf_vl_data *vl;
        struct listnode *node;
        int count = 0;

        for (ALL_LIST_ELEMENTS_RO(ospf->vlinks, node, vl))
                if (IPV4_ADDR_SAME(&vl->vl_area_id, &area->area_id))
                        count++;

        return count;
}

int ospf_area_display_format_set(struct ospf *ospf, struct ospf_area *area,
                                 int df)
{
        area->area_id_fmt = df;

        return 1;
}

int ospf_area_stub_set(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_get(ospf, area_id);
        if (ospf_area_vlink_count(ospf, area))
                return 0;

        if (area->external_routing != OSPF_AREA_STUB)
                ospf_area_type_set(area, OSPF_AREA_STUB);

        return 1;
}

int ospf_area_stub_unset(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_lookup_by_area_id(ospf, area_id);
        if (area == NULL)
                return 1;

        if (area->external_routing == OSPF_AREA_STUB)
                ospf_area_type_set(area, OSPF_AREA_DEFAULT);

        ospf_area_check_free(ospf, area_id);

        return 1;
}

int ospf_area_no_summary_set(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_get(ospf, area_id);
        area->no_summary = 1;

        return 1;
}

int ospf_area_no_summary_unset(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_lookup_by_area_id(ospf, area_id);
        if (area == NULL)
                return 0;

        area->no_summary = 0;
        ospf_area_check_free(ospf, area_id);

        return 1;
}

int ospf_area_nssa_no_summary_set(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_get(ospf, area_id);
        if (ospf_area_vlink_count(ospf, area))
                return 0;

        if (area->external_routing != OSPF_AREA_NSSA) {
                ospf_area_type_set(area, OSPF_AREA_NSSA);
                ospf->anyNSSA++;
                area->NSSATranslatorRole = OSPF_NSSA_ROLE_CANDIDATE;
        }

        ospf_area_no_summary_set(ospf, area_id);

        return 1;
}

int ospf_area_nssa_set(struct ospf *ospf, struct in_addr area_id)
{
        struct ospf_area *area;

        area = ospf_area_get(ospf, area_id);
        if (ospf_area_vlink_count(ospf, area))
                return 0;

        if (area->external_routing != OSPF_AREA_NSSA) {
                ospf_area_type_set(area, OSPF_AREA_NSSA);
                ospf->anyNSSA++;

                /* set NSSA area defaults */
                area->no_summary = 0;
                area->NSSATranslatorRole = OSPF_NSSA_ROLE_CANDIDATE;
                area->NSSATranslatorState = OSPF_NSSA_TRANSLATE_DISABLED;
                area->NSSATranslatorStabilityInterval =
                        OSPF_NSSA_TRANS_STABLE_DEFAULT;
        }
        return 1;
}

int ospf_area_nssa_unset(struct ospf *ospf, struct in_addr area_id, int argc)
{
        struct ospf_area *area;

        area = ospf_area_lookup_by_area_id(ospf, area_id);
        if (area == NULL)
                return 0;

        /* argc < 5 -> 'no area x nssa' */
        if (argc < 5 && area->external_routing == OSPF_AREA_NSSA) {
                ospf->anyNSSA--;
                /* set NSSA area defaults */
                area->no_summary = 0;
                area->NSSATranslatorRole = OSPF_NSSA_ROLE_CANDIDATE;
                area->NSSATranslatorState = OSPF_NSSA_TRANSLATE_DISABLED;
                area->NSSATranslatorStabilityInterval =
                        OSPF_NSSA_TRANS_STABLE_DEFAULT;
                ospf_area_type_set(area, OSPF_AREA_DEFAULT);
        } else {
                area->NSSATranslatorRole = OSPF_NSSA_ROLE_CANDIDATE;
        }

        ospf_area_check_free(ospf, area_id);

        return 1;
}

int ospf_area_nssa_translator_role_set(struct ospf *ospf,
                                       struct in_addr area_id, int role)
{
        struct ospf_area *area;

        area = ospf_area_lookup_by_area_id(ospf, area_id);
        if (area == NULL)
                return 0;

        area->NSSATranslatorRole = role;

        return 1;
}

#if 0
/* XXX: unused? Leave for symmetry? */
static int
ospf_area_nssa_translator_role_unset (struct ospf *ospf,
                                      struct in_addr area_id)
{
  struct ospf_area *area;

  area = ospf_area_lookup_by_area_id (ospf, area_id);
  if (area == NULL)
    return 0;

  area->NSSATranslatorRole = OSPF_NSSA_ROLE_CANDIDATE;

  ospf_area_check_free (ospf, area_id);

  return 1;
}
#endif

int ospf_area_export_list_set(struct ospf *ospf, struct ospf_area *area,
                              const char *list_name)
{
        struct access_list *list;
        list = access_list_lookup(AFI_IP, list_name);

        EXPORT_LIST(area) = list;

        if (EXPORT_NAME(area))
                free(EXPORT_NAME(area));

        EXPORT_NAME(area) = strdup(list_name);
        ospf_schedule_abr_task(ospf);

        return 1;
}

int ospf_area_export_list_unset(struct ospf *ospf, struct ospf_area *area)
{

        EXPORT_LIST(area) = 0;

        if (EXPORT_NAME(area))
                free(EXPORT_NAME(area));

        EXPORT_NAME(area) = NULL;

        ospf_area_check_free(ospf, area->area_id);

        ospf_schedule_abr_task(ospf);

        return 1;
}

int ospf_area_import_list_set(struct ospf *ospf, struct ospf_area *area,
                              const char *name)
{
        struct access_list *list;
        list = access_list_lookup(AFI_IP, name);

        IMPORT_LIST(area) = list;

        if (IMPORT_NAME(area))
                free(IMPORT_NAME(area));

        IMPORT_NAME(area) = strdup(name);
        ospf_schedule_abr_task(ospf);

        return 1;
}

int ospf_area_import_list_unset(struct ospf *ospf, struct ospf_area *area)
{
        IMPORT_LIST(area) = 0;

        if (IMPORT_NAME(area))
                free(IMPORT_NAME(area));

        IMPORT_NAME(area) = NULL;
        ospf_area_check_free(ospf, area->area_id);

        ospf_schedule_abr_task(ospf);

        return 1;
}

int ospf_timers_refresh_set(struct ospf *ospf, int interval)
{
        int time_left;

        if (ospf->lsa_refresh_interval == interval)
                return 1;

        time_left = ospf->lsa_refresh_interval
                    - (monotime(NULL) - ospf->lsa_refresher_started);

        if (time_left > interval) {
                OSPF_TIMER_OFF(ospf->t_lsa_refresher);
                thread_add_timer(master, ospf_lsa_refresh_walker, ospf,
                                 interval, &ospf->t_lsa_refresher);
        }
        ospf->lsa_refresh_interval = interval;

        return 1;
}

int ospf_timers_refresh_unset(struct ospf *ospf)
{
        int time_left;

        time_left = ospf->lsa_refresh_interval
                    - (monotime(NULL) - ospf->lsa_refresher_started);

        if (time_left > OSPF_LSA_REFRESH_INTERVAL_DEFAULT) {
                OSPF_TIMER_OFF(ospf->t_lsa_refresher);
                ospf->t_lsa_refresher = NULL;
                thread_add_timer(master, ospf_lsa_refresh_walker, ospf,
                                 OSPF_LSA_REFRESH_INTERVAL_DEFAULT,
                                 &ospf->t_lsa_refresher);
        }

        ospf->lsa_refresh_interval = OSPF_LSA_REFRESH_INTERVAL_DEFAULT;

        return 1;
}


static struct ospf_nbr_nbma *ospf_nbr_nbma_new(void)
{
        struct ospf_nbr_nbma *nbr_nbma;

        nbr_nbma = XCALLOC(MTYPE_OSPF_NEIGHBOR_STATIC,
                           sizeof(struct ospf_nbr_nbma));

        nbr_nbma->priority = OSPF_NEIGHBOR_PRIORITY_DEFAULT;
        nbr_nbma->v_poll = OSPF_POLL_INTERVAL_DEFAULT;

        return nbr_nbma;
}

static void ospf_nbr_nbma_free(struct ospf_nbr_nbma *nbr_nbma)
{
        XFREE(MTYPE_OSPF_NEIGHBOR_STATIC, nbr_nbma);
}

static void ospf_nbr_nbma_delete(struct ospf *ospf,
                                 struct ospf_nbr_nbma *nbr_nbma)
{
        struct route_node *rn;
        struct prefix_ipv4 p;

        p.family = AF_INET;
        p.prefix = nbr_nbma->addr;
        p.prefixlen = IPV4_MAX_BITLEN;

        rn = route_node_lookup(ospf->nbr_nbma, (struct prefix *)&p);
        if (rn) {
                ospf_nbr_nbma_free(rn->info);
                rn->info = NULL;
                route_unlock_node(rn);
                route_unlock_node(rn);
        }
}

static void ospf_nbr_nbma_down(struct ospf_nbr_nbma *nbr_nbma)
{
        OSPF_TIMER_OFF(nbr_nbma->t_poll);

        if (nbr_nbma->nbr) {
                nbr_nbma->nbr->nbr_nbma = NULL;
                OSPF_NSM_EVENT_EXECUTE(nbr_nbma->nbr, NSM_KillNbr);
        }

        if (nbr_nbma->oi)
                listnode_delete(nbr_nbma->oi->nbr_nbma, nbr_nbma);
}

static void ospf_nbr_nbma_add(struct ospf_nbr_nbma *nbr_nbma,
                              struct ospf_interface *oi)
{
        struct ospf_neighbor *nbr;
        struct route_node *rn;
        struct prefix p;

        if (oi->type != OSPF_IFTYPE_NBMA)
                return;

        if (nbr_nbma->nbr != NULL)
                return;

        if (IPV4_ADDR_SAME(&oi->nbr_self->address.u.prefix4, &nbr_nbma->addr))
                return;

        nbr_nbma->oi = oi;
        listnode_add(oi->nbr_nbma, nbr_nbma);

        /* Get neighbor information from table. */
        p.family = AF_INET;
        p.prefixlen = IPV4_MAX_BITLEN;
        p.u.prefix4 = nbr_nbma->addr;

        rn = route_node_get(oi->nbrs, (struct prefix *)&p);
        if (rn->info) {
                nbr = rn->info;
                nbr->nbr_nbma = nbr_nbma;
                nbr_nbma->nbr = nbr;

                route_unlock_node(rn);
        } else {
                nbr = rn->info = ospf_nbr_new(oi);
                nbr->state = NSM_Down;
                nbr->src = nbr_nbma->addr;
                nbr->nbr_nbma = nbr_nbma;
                nbr->priority = nbr_nbma->priority;
                nbr->address = p;

                nbr_nbma->nbr = nbr;

                OSPF_NSM_EVENT_EXECUTE(nbr, NSM_Start);
        }
}

void ospf_nbr_nbma_if_update(struct ospf *ospf, struct ospf_interface *oi)
{
        struct ospf_nbr_nbma *nbr_nbma;
        struct route_node *rn;
        struct prefix_ipv4 p;

        if (oi->type != OSPF_IFTYPE_NBMA)
                return;

        for (rn = route_top(ospf->nbr_nbma); rn; rn = route_next(rn))
                if ((nbr_nbma = rn->info))
                        if (nbr_nbma->oi == NULL && nbr_nbma->nbr == NULL) {
                                p.family = AF_INET;
                                p.prefix = nbr_nbma->addr;
                                p.prefixlen = IPV4_MAX_BITLEN;

                                if (prefix_match(oi->address,
                                                 (struct prefix *)&p))
                                        ospf_nbr_nbma_add(nbr_nbma, oi);
                        }
}

struct ospf_nbr_nbma *ospf_nbr_nbma_lookup(struct ospf *ospf,
                                           struct in_addr nbr_addr)
{
        struct route_node *rn;
        struct prefix_ipv4 p;

        p.family = AF_INET;
        p.prefix = nbr_addr;
        p.prefixlen = IPV4_MAX_BITLEN;

        rn = route_node_lookup(ospf->nbr_nbma, (struct prefix *)&p);
        if (rn) {
                route_unlock_node(rn);
                return rn->info;
        }
        return NULL;
}

struct ospf_nbr_nbma *ospf_nbr_nbma_lookup_next(struct ospf *ospf,
                                                struct in_addr *addr, int first)
{
#if 0
  struct ospf_nbr_nbma *nbr_nbma;
  struct listnode *node;
#endif

        if (ospf == NULL)
                return NULL;

#if 0
  for (ALL_LIST_ELEMENTS_RO (ospf->nbr_nbma, node, nbr_nbma))
    {
      if (first)
        {
          *addr = nbr_nbma->addr;
          return nbr_nbma;
        }
      else if (ntohl (nbr_nbma->addr.s_addr) > ntohl (addr->s_addr))
        {
          *addr = nbr_nbma->addr;
          return nbr_nbma;
        }
    }
#endif
        return NULL;
}

int ospf_nbr_nbma_set(struct ospf *ospf, struct in_addr nbr_addr)
{
        struct ospf_nbr_nbma *nbr_nbma;
        struct ospf_interface *oi;
        struct prefix_ipv4 p;
        struct route_node *rn;
        struct listnode *node;

        nbr_nbma = ospf_nbr_nbma_lookup(ospf, nbr_addr);
        if (nbr_nbma)
                return 0;

        nbr_nbma = ospf_nbr_nbma_new();
        nbr_nbma->addr = nbr_addr;

        p.family = AF_INET;
        p.prefix = nbr_addr;
        p.prefixlen = IPV4_MAX_BITLEN;

        rn = route_node_get(ospf->nbr_nbma, (struct prefix *)&p);
        if (rn->info)
                route_unlock_node(rn);
        rn->info = nbr_nbma;

        for (ALL_LIST_ELEMENTS_RO(ospf->oiflist, node, oi)) {
                if (oi->type == OSPF_IFTYPE_NBMA)
                        if (prefix_match(oi->address, (struct prefix *)&p)) {
                                ospf_nbr_nbma_add(nbr_nbma, oi);
                                break;
                        }
        }

        return 1;
}

int ospf_nbr_nbma_unset(struct ospf *ospf, struct in_addr nbr_addr)
{
        struct ospf_nbr_nbma *nbr_nbma;

        nbr_nbma = ospf_nbr_nbma_lookup(ospf, nbr_addr);
        if (nbr_nbma == NULL)
                return 0;

        ospf_nbr_nbma_down(nbr_nbma);
        ospf_nbr_nbma_delete(ospf, nbr_nbma);

        return 1;
}

int ospf_nbr_nbma_priority_set(struct ospf *ospf, struct in_addr nbr_addr,
                               uint8_t priority)
{
        struct ospf_nbr_nbma *nbr_nbma;

        nbr_nbma = ospf_nbr_nbma_lookup(ospf, nbr_addr);
        if (nbr_nbma == NULL)
                return 0;

        if (nbr_nbma->priority != priority)
                nbr_nbma->priority = priority;

        return 1;
}

int ospf_nbr_nbma_priority_unset(struct ospf *ospf, struct in_addr nbr_addr)
{
        struct ospf_nbr_nbma *nbr_nbma;

        nbr_nbma = ospf_nbr_nbma_lookup(ospf, nbr_addr);
        if (nbr_nbma == NULL)
                return 0;

        if (nbr_nbma != OSPF_NEIGHBOR_PRIORITY_DEFAULT)
                nbr_nbma->priority = OSPF_NEIGHBOR_PRIORITY_DEFAULT;

        return 1;
}

int ospf_nbr_nbma_poll_interval_set(struct ospf *ospf, struct in_addr nbr_addr,
                                    unsigned int interval)
{
        struct ospf_nbr_nbma *nbr_nbma;

        nbr_nbma = ospf_nbr_nbma_lookup(ospf, nbr_addr);
        if (nbr_nbma == NULL)
                return 0;

        if (nbr_nbma->v_poll != interval) {
                nbr_nbma->v_poll = interval;
                if (nbr_nbma->oi && ospf_if_is_up(nbr_nbma->oi)) {
                        OSPF_TIMER_OFF(nbr_nbma->t_poll);
                        OSPF_POLL_TIMER_ON(nbr_nbma->t_poll, ospf_poll_timer,
                                           nbr_nbma->v_poll);
                }
        }

        return 1;
}

int ospf_nbr_nbma_poll_interval_unset(struct ospf *ospf, struct in_addr addr)
{
        struct ospf_nbr_nbma *nbr_nbma;

        nbr_nbma = ospf_nbr_nbma_lookup(ospf, addr);
        if (nbr_nbma == NULL)
                return 0;

        if (nbr_nbma->v_poll != OSPF_POLL_INTERVAL_DEFAULT)
                nbr_nbma->v_poll = OSPF_POLL_INTERVAL_DEFAULT;

        return 1;
}

void ospf_master_init(struct thread_master *master)
{
        memset(&ospf_master, 0, sizeof(struct ospf_master));

        om = &ospf_master;
        om->ospf = list_new();
        om->master = master;
}

/* Link OSPF instance to VRF. */
void ospf_vrf_link(struct ospf *ospf, struct vrf *vrf)
{
        ospf->vrf_id = vrf->vrf_id;
        if (vrf->info != (void *)ospf)
                vrf->info = (void *)ospf;
}

/* Unlink OSPF instance from VRF. */
void ospf_vrf_unlink(struct ospf *ospf, struct vrf *vrf)
{
        if (vrf->info == (void *)ospf)
                vrf->info = NULL;
        ospf->vrf_id = VRF_UNKNOWN;
}

/* This is hook function for vrf create called as part of vrf_init */
static int ospf_vrf_new(struct vrf *vrf)
{
        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("%s: VRF Created: %s(%u)", __PRETTY_FUNCTION__,
                           vrf->name, vrf->vrf_id);

        return 0;
}

/* This is hook function for vrf delete call as part of vrf_init */
static int ospf_vrf_delete(struct vrf *vrf)
{
        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("%s: VRF Deletion: %s(%u)", __PRETTY_FUNCTION__,
                           vrf->name, vrf->vrf_id);

        return 0;
}

static void ospf_set_redist_vrf_bitmaps(struct ospf *ospf)
{
        int type;
        struct list *red_list;

        for (type = 0; type < ZEBRA_ROUTE_MAX; type++) {
                red_list = ospf->redist[type];
                if (!red_list)
                        continue;
                if (IS_DEBUG_OSPF_EVENT)
                        zlog_debug(
                                "%s: setting redist vrf %d bitmap for type %d",
                                __func__, ospf->vrf_id, type);
                vrf_bitmap_set(zclient->redist[AFI_IP][type], ospf->vrf_id);
        }
}

/* Enable OSPF VRF instance */
static int ospf_vrf_enable(struct vrf *vrf)
{
        struct ospf *ospf = NULL;
        vrf_id_t old_vrf_id;
        int ret = 0;

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("%s: VRF %s id %u enabled", __PRETTY_FUNCTION__,
                           vrf->name, vrf->vrf_id);

        ospf = ospf_lookup_by_name(vrf->name);
        if (ospf) {
                old_vrf_id = ospf->vrf_id;
                /* We have instance configured, link to VRF and make it "up". */
                ospf_vrf_link(ospf, vrf);
                if (IS_DEBUG_OSPF_EVENT)
                        zlog_debug(
                                "%s: ospf linked to vrf %s vrf_id %u (old id %u)",
                                __PRETTY_FUNCTION__, vrf->name, ospf->vrf_id,
                                old_vrf_id);

                if (old_vrf_id != ospf->vrf_id) {
                        if (ospfd_privs.change(ZPRIVS_RAISE)) {
                                zlog_err(
                                        "ospf_sock_init: could not raise privs, %s",
                                        safe_strerror(errno));
                        }

                        /* stop zebra redist to us for old vrf */
                        zclient_send_dereg_requests(zclient, old_vrf_id);

                        ospf_set_redist_vrf_bitmaps(ospf);

                        /* start zebra redist to us for new vrf */
                        ospf_zebra_vrf_register(ospf);

                        ret = ospf_sock_init(ospf);
                        if (ospfd_privs.change(ZPRIVS_LOWER)) {
                                zlog_err(
                                        "ospf_sock_init: could not lower privs, %s",
                                        safe_strerror(errno));
                        }
                        if (ret < 0 || ospf->fd <= 0)
                                return 0;
                        thread_add_read(master, ospf_read, ospf, ospf->fd,
                                        &ospf->t_read);
                        ospf->oi_running = 1;
                        ospf_router_id_update(ospf);
                }
        }

        return 0;
}

/* Disable OSPF VRF instance */
static int ospf_vrf_disable(struct vrf *vrf)
{
        struct ospf *ospf = NULL;
        vrf_id_t old_vrf_id = VRF_UNKNOWN;

        if (vrf->vrf_id == VRF_DEFAULT)
                return 0;

        if (IS_DEBUG_OSPF_EVENT)
                zlog_debug("%s: VRF %s id %d disabled.", __PRETTY_FUNCTION__,
                           vrf->name, vrf->vrf_id);

        ospf = ospf_lookup_by_name(vrf->name);
        if (ospf) {
                old_vrf_id = ospf->vrf_id;

                /* We have instance configured, unlink
                 * from VRF and make it "down".
                 */
                ospf_vrf_unlink(ospf, vrf);
                ospf->oi_running = 0;
                if (IS_DEBUG_OSPF_EVENT)
                        zlog_debug("%s: ospf old_vrf_id %d unlinked",
                                   __PRETTY_FUNCTION__, old_vrf_id);
                thread_cancel(ospf->t_read);
                close(ospf->fd);
                ospf->fd = -1;
        }

        /* Note: This is a callback, the VRF will be deleted by the caller. */
        return 0;
}

void ospf_vrf_init(void)
{
        vrf_init(ospf_vrf_new, ospf_vrf_enable, ospf_vrf_disable,
                 ospf_vrf_delete);
}

void ospf_vrf_terminate(void)
{
        vrf_terminate();
}

const char *ospf_vrf_id_to_name(vrf_id_t vrf_id)
{
        struct vrf *vrf = vrf_lookup_by_id(vrf_id);

        return vrf ? vrf->name : "NIL";
}