/*      $OpenBSD: rde_spf.c,v 1.79 2023/03/08 04:43:14 guenther Exp $ */

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

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <stdlib.h>
#include <string.h>

#include "ospfd.h"
#include "ospf.h"
#include "log.h"
#include "rde.h"

extern struct ospfd_conf        *rdeconf;
TAILQ_HEAD(, vertex)             cand_list;
RB_HEAD(rt_tree, rt_node)        rt;
RB_PROTOTYPE(rt_tree, rt_node, entry, rt_compare)
RB_GENERATE(rt_tree, rt_node, entry, rt_compare)
struct vertex                   *spf_root = NULL;

void     calc_nexthop(struct vertex *, struct vertex *,
             struct area *, struct lsa_rtr_link *);
void     rt_nexthop_clear(struct rt_node *);
void     rt_nexthop_add(struct rt_node *, struct v_nexthead *, u_int8_t,
             struct in_addr);
void     rt_update(struct in_addr, u_int8_t, struct v_nexthead *, u_int8_t,
             u_int32_t, u_int32_t, struct in_addr, struct in_addr,
             enum path_type, enum dst_type, u_int8_t, u_int32_t);
void     rt_invalidate(struct area *);
struct lsa_rtr_link     *get_rtr_link(struct vertex *, int);
struct lsa_net_link     *get_net_link(struct vertex *, int);
int      linked(struct vertex *, struct vertex *);

void
spf_calc(struct area *area)
{
        struct vertex           *v, *w;
        struct lsa_rtr_link     *rtr_link = NULL;
        struct lsa_net_link     *net_link;
        u_int32_t                d;
        int                      i;
        struct in_addr           addr;

        /* clear SPF tree */
        spf_tree_clr(area);
        cand_list_clr();

        /* initialize SPF tree */
        if ((v = spf_root = lsa_find_area(area, LSA_TYPE_ROUTER,
            rde_router_id(), rde_router_id())) == NULL) {
                /* empty area because no interface is active */
                return;
        }

        area->transit = 0;
        spf_root->cost = 0;
        w = NULL;

        /* make sure the spf root has a nexthop */
        vertex_nexthop_clear(spf_root);
        vertex_nexthop_add(spf_root, spf_root, 0);

        /* calculate SPF tree */
        do {
                /* loop links */
                for (i = 0; i < lsa_num_links(v); i++) {
                        switch (v->type) {
                        case LSA_TYPE_ROUTER:
                                rtr_link = get_rtr_link(v, i);
                                switch (rtr_link->type) {
                                case LINK_TYPE_STUB_NET:
                                        /* skip */
                                        continue;
                                case LINK_TYPE_POINTTOPOINT:
                                case LINK_TYPE_VIRTUAL:
                                        /* find router LSA */
                                        w = lsa_find_area(area, LSA_TYPE_ROUTER,
                                            rtr_link->id, rtr_link->id);
                                        break;
                                case LINK_TYPE_TRANSIT_NET:
                                        /* find network LSA */
                                        w = lsa_find_net(area, rtr_link->id);
                                        break;
                                default:
                                        fatalx("spf_calc: invalid link type");
                                }
                                break;
                        case LSA_TYPE_NETWORK:
                                net_link = get_net_link(v, i);
                                /* find router LSA */
                                w = lsa_find_area(area, LSA_TYPE_ROUTER,
                                    net_link->att_rtr, net_link->att_rtr);
                                break;
                        default:
                                fatalx("spf_calc: invalid LSA type");
                        }

                        if (w == NULL)
                                continue;

                        if (w->lsa->hdr.age == MAX_AGE)
                                continue;

                        if (!linked(w, v)) {
                                addr.s_addr = htonl(w->ls_id);
                                log_debug("spf_calc: w id %s type %d has ",
                                    inet_ntoa(addr), w->type);
                                addr.s_addr = htonl(v->ls_id);
                                log_debug("    no link to v id %s type %d",
                                    inet_ntoa(addr), v->type);
                                continue;
                        }

                        if (v->type == LSA_TYPE_ROUTER)
                                d = v->cost + ntohs(rtr_link->metric);
                        else
                                d = v->cost;

                        if (cand_list_present(w)) {
                                if (d > w->cost)
                                        continue;
                                if (d < w->cost) {
                                        w->cost = d;
                                        vertex_nexthop_clear(w);
                                        calc_nexthop(w, v, area, rtr_link);
                                        /*
                                         * need to readd to candidate list
                                         * because the list is sorted
                                         */
                                        TAILQ_REMOVE(&cand_list, w, cand);
                                        cand_list_add(w);
                                } else
                                        /* equal cost path */
                                        calc_nexthop(w, v, area, rtr_link);
                        } else if (w->cost == LS_INFINITY && d < LS_INFINITY) {
                                w->cost = d;

                                vertex_nexthop_clear(w);
                                calc_nexthop(w, v, area, rtr_link);
                                cand_list_add(w);
                        }
                }

                /* get next vertex */
                v = cand_list_pop();
                w = NULL;
        } while (v != NULL);

        /* spf_dump(area); */
        log_debug("spf_calc: area %s calculated", inet_ntoa(area->id));

        area->num_spf_calc++;
        start_spf_timer();
}

void
rt_calc(struct vertex *v, struct area *area, struct ospfd_conf *conf)
{
        struct vertex           *w;
        struct v_nexthop        *vn;
        struct lsa_rtr_link     *rtr_link = NULL;
        int                      i;
        struct in_addr           addr, adv_rtr;

        lsa_age(v);
        if (ntohs(v->lsa->hdr.age) == MAX_AGE)
                return;

        switch (v->type) {
        case LSA_TYPE_ROUTER:
                /* stub networks */
                if (v->cost >= LS_INFINITY)
                        return;

                for (i = 0; i < lsa_num_links(v); i++) {
                        rtr_link = get_rtr_link(v, i);
                        if (rtr_link->type != LINK_TYPE_STUB_NET)
                                continue;

                        addr.s_addr = rtr_link->id & rtr_link->data;
                        adv_rtr.s_addr = htonl(v->adv_rtr);

                        rt_update(addr, mask2prefixlen(rtr_link->data),
                            &v->nexthop, v->type,
                            v->cost + ntohs(rtr_link->metric), 0,
                            area->id, adv_rtr, PT_INTRA_AREA, DT_NET,
                            v->lsa->data.rtr.flags, 0);
                }

                /* router, only add border and as-external routers */
                if ((v->lsa->data.rtr.flags & (OSPF_RTR_B | OSPF_RTR_E)) == 0)
                        return;

                addr.s_addr = htonl(v->ls_id);
                adv_rtr.s_addr = htonl(v->adv_rtr);

                rt_update(addr, 32, &v->nexthop, v->type, v->cost, 0, area->id,
                    adv_rtr, PT_INTRA_AREA, DT_RTR, v->lsa->data.rtr.flags, 0);
                break;
        case LSA_TYPE_NETWORK:
                if (v->cost >= LS_INFINITY)
                        return;

                addr.s_addr = htonl(v->ls_id) & v->lsa->data.net.mask;
                adv_rtr.s_addr = htonl(v->adv_rtr);
                rt_update(addr, mask2prefixlen(v->lsa->data.net.mask),
                    &v->nexthop, v->type, v->cost, 0, area->id, adv_rtr,
                    PT_INTRA_AREA, DT_NET, 0, 0);
                break;
        case LSA_TYPE_SUM_NETWORK:
        case LSA_TYPE_SUM_ROUTER:
                /* if ABR only look at area 0.0.0.0 LSA */
                if (area_border_router(conf) && area->id.s_addr != INADDR_ANY)
                        return;

                /* ignore self-originated stuff */
                if (v->self)
                        return;

                /* TODO type 3 area address range check */

                if ((w = lsa_find_area(area, LSA_TYPE_ROUTER,
                    htonl(v->adv_rtr),
                    htonl(v->adv_rtr))) == NULL)
                        return;

                /* copy nexthops */
                vertex_nexthop_clear(v);        /* XXX needed ??? */
                TAILQ_FOREACH(vn, &w->nexthop, entry)
                        vertex_nexthop_add(v, w, vn->nexthop.s_addr);

                v->cost = w->cost +
                    (ntohl(v->lsa->data.sum.metric) & LSA_METRIC_MASK);

                if (v->cost >= LS_INFINITY)
                        return;

                adv_rtr.s_addr = htonl(v->adv_rtr);
                if (v->type == LSA_TYPE_SUM_NETWORK) {
                        addr.s_addr = htonl(v->ls_id) & v->lsa->data.sum.mask;
                        rt_update(addr, mask2prefixlen(v->lsa->data.sum.mask),
                            &v->nexthop, v->type, v->cost, 0, area->id, adv_rtr,
                            PT_INTER_AREA, DT_NET, 0, 0);
                } else {
                        addr.s_addr = htonl(v->ls_id);
                        rt_update(addr, 32, &v->nexthop, v->type, v->cost, 0,
                            area->id, adv_rtr, PT_INTER_AREA, DT_RTR,
                            v->lsa->data.rtr.flags, 0);
                }

                break;
        case LSA_TYPE_AREA_OPAQ:
                /* nothing to calculate */
                break;
        default:
                /* as-external LSA are stored in a different tree */
                fatalx("rt_calc: invalid LSA type");
        }
}

void
asext_calc(struct vertex *v)
{
        struct rt_node          *r;
        struct rt_nexthop       *rn;
        u_int32_t                cost2;
        struct in_addr           addr, adv_rtr, a;
        enum path_type           type;

        lsa_age(v);
        if (ntohs(v->lsa->hdr.age) == MAX_AGE ||
            (ntohl(v->lsa->data.asext.metric) & LSA_METRIC_MASK) >=
            LS_INFINITY)
                return;

        switch (v->type) {
        case LSA_TYPE_EXTERNAL:
                /* ignore self-originated stuff */
                if (v->self)
                        return;

                if ((r = rt_lookup(DT_RTR, htonl(v->adv_rtr))) == NULL)
                        return;

                /* XXX RFC1583Compatibility */
                if (v->lsa->data.asext.fw_addr != 0 &&
                    (r = rt_lookup(DT_NET, v->lsa->data.asext.fw_addr)) == NULL)
                        return;

                if (v->lsa->data.asext.fw_addr != 0 &&
                    r->p_type != PT_INTRA_AREA &&
                    r->p_type != PT_INTER_AREA)
                        return;

                if (ntohl(v->lsa->data.asext.metric) & LSA_ASEXT_E_FLAG) {
                        v->cost = r->cost;
                        cost2 = ntohl(v->lsa->data.asext.metric) &
                            LSA_METRIC_MASK;
                        type = PT_TYPE2_EXT;
                } else {
                        v->cost = r->cost + (ntohl(v->lsa->data.asext.metric) &
                             LSA_METRIC_MASK);
                        cost2 = 0;
                        type = PT_TYPE1_EXT;
                }

                a.s_addr = 0;
                adv_rtr.s_addr = htonl(v->adv_rtr);
                addr.s_addr = htonl(v->ls_id) & v->lsa->data.asext.mask;

                vertex_nexthop_clear(v);
                TAILQ_FOREACH(rn, &r->nexthop, entry) {
                        if (rn->invalid)
                                continue;

                        /*
                         * if a fw_addr is specified and the nexthop
                         * is directly connected then it is possible to
                         * send traffic directly to fw_addr.
                         */
                        if (v->lsa->data.asext.fw_addr != 0 && rn->connected)
                                vertex_nexthop_add(v, NULL,
                                    v->lsa->data.asext.fw_addr);
                        else
                                vertex_nexthop_add(v, NULL, rn->nexthop.s_addr);
                }

                rt_update(addr, mask2prefixlen(v->lsa->data.asext.mask),
                    &v->nexthop, v->type, v->cost, cost2, a, adv_rtr, type,
                    DT_NET, 0, ntohl(v->lsa->data.asext.ext_tag));
                break;
        case LSA_TYPE_AS_OPAQ:
                /* nothing to calculate */
                break;
        default:
                fatalx("asext_calc: invalid LSA type");
        }
}

void
spf_tree_clr(struct area *area)
{
        struct lsa_tree *tree = &area->lsa_tree;
        struct vertex   *v;

        RB_FOREACH(v, lsa_tree, tree) {
                v->cost = LS_INFINITY;
                vertex_nexthop_clear(v);
        }
}

void
calc_nexthop(struct vertex *dst, struct vertex *parent,
    struct area *area, struct lsa_rtr_link *rtr_link)
{
        struct v_nexthop        *vn;
        struct iface            *iface;
        struct rde_nbr          *nbr;
        int                      i;

        /* case 1 */
        if (parent == spf_root) {
                switch (dst->type) {
                case LSA_TYPE_ROUTER:
                        if (rtr_link->type != LINK_TYPE_POINTTOPOINT)
                                fatalx("inconsistent SPF tree");
                        LIST_FOREACH(iface, &area->iface_list, entry) {
                                if (rtr_link->data != iface->addr.s_addr)
                                        continue;
                                LIST_FOREACH(nbr, &area->nbr_list, entry) {
                                        if (nbr->ifindex == iface->ifindex) {
                                                vertex_nexthop_add(dst, parent,
                                                    nbr->addr.s_addr);
                                                return;
                                        }
                                }
                        }
                        fatalx("no interface found for interface");
                case LSA_TYPE_NETWORK:
                        switch (rtr_link->type) {
                        case LINK_TYPE_POINTTOPOINT:
                        case LINK_TYPE_STUB_NET:
                                /* ignore */
                                break;
                        case LINK_TYPE_TRANSIT_NET:
                                if ((htonl(dst->ls_id) &
                                    dst->lsa->data.net.mask) ==
                                    (rtr_link->data &
                                     dst->lsa->data.net.mask)) {
                                        vertex_nexthop_add(dst, parent,
                                            rtr_link->data);
                                }
                                break;
                        default:
                                fatalx("calc_nexthop: invalid link "
                                    "type");
                        }
                        return;
                default:
                        fatalx("calc_nexthop: invalid dst type");
                }
                return;
        }

        /* case 2 */
        if (parent->type == LSA_TYPE_NETWORK && dst->type == LSA_TYPE_ROUTER) {
                TAILQ_FOREACH(vn, &parent->nexthop, entry) {
                        if (vn->prev == spf_root) {
                                for (i = 0; i < lsa_num_links(dst); i++) {
                                        rtr_link = get_rtr_link(dst, i);
                                        if ((rtr_link->type ==
                                            LINK_TYPE_TRANSIT_NET) &&
                                            (rtr_link->data &
                                            parent->lsa->data.net.mask) ==
                                            (htonl(parent->ls_id) &
                                            parent->lsa->data.net.mask))
                                                vertex_nexthop_add(dst, parent,
                                                    rtr_link->data);
                                }
                        } else {
                                vertex_nexthop_add(dst, parent,
                                    vn->nexthop.s_addr);
                        }
                }
                return;
        }

        /* case 3 */
        TAILQ_FOREACH(vn, &parent->nexthop, entry)
                vertex_nexthop_add(dst, parent, vn->nexthop.s_addr);
}

/* candidate list */
void
cand_list_init(void)
{
        TAILQ_INIT(&cand_list);
}

void
cand_list_add(struct vertex *v)
{
        struct vertex   *c = NULL;

        TAILQ_FOREACH(c, &cand_list, cand) {
                if (c->cost > v->cost) {
                        TAILQ_INSERT_BEFORE(c, v, cand);
                        return;
                } else if (c->cost == v->cost && c->type == LSA_TYPE_ROUTER &&
                    v->type == LSA_TYPE_NETWORK) {
                        TAILQ_INSERT_BEFORE(c, v, cand);
                        return;
                }
        }
        TAILQ_INSERT_TAIL(&cand_list, v, cand);
}

struct vertex *
cand_list_pop(void)
{
        struct vertex   *c;

        if ((c = TAILQ_FIRST(&cand_list)) != NULL) {
                TAILQ_REMOVE(&cand_list, c, cand);
        }

        return (c);
}

int
cand_list_present(struct vertex *v)
{
        struct vertex   *c;

        TAILQ_FOREACH(c, &cand_list, cand) {
                if (c == v)
                        return (1);
        }

        return (0);
}

void
cand_list_clr(void)
{
        struct vertex *c;

        while ((c = TAILQ_FIRST(&cand_list)) != NULL) {
                TAILQ_REMOVE(&cand_list, c, cand);
        }
}

/* timers */
void
spf_timer(int fd, short event, void *arg)
{
        struct vertex           *v;
        struct ospfd_conf       *conf = arg;
        struct area             *area;
        struct rt_node          *r;

        switch (conf->spf_state) {
        case SPF_IDLE:
                fatalx("spf_timer: invalid state IDLE");
        case SPF_HOLDQUEUE:
                conf->spf_state = SPF_DELAY;
                /* FALLTHROUGH */
        case SPF_DELAY:
                LIST_FOREACH(area, &conf->area_list, entry) {
                        if (area->dirty) {
                                /* invalidate RIB entries of this area */
                                rt_invalidate(area);

                                /* calculate SPF tree */
                                spf_calc(area);

                                /* calculate route table */
                                RB_FOREACH(v, lsa_tree, &area->lsa_tree) {
                                        rt_calc(v, area, conf);
                                }

                                area->dirty = 0;
                        }
                }

                /* calculate as-external routes, first invalidate them */
                rt_invalidate(NULL);
                RB_FOREACH(v, lsa_tree, &asext_tree) {
                        asext_calc(v);
                }

                RB_FOREACH(r, rt_tree, &rt) {
                        LIST_FOREACH(area, &conf->area_list, entry)
                                rde_summary_update(r, area);

                        if (r->d_type != DT_NET)
                                continue;

                        if (r->invalid)
                                rde_send_delete_kroute(r);
                        else
                                rde_send_change_kroute(r);
                }

                LIST_FOREACH(area, &conf->area_list, entry) {
                        lsa_generate_stub_sums(area);
                        lsa_remove_invalid_sums(area);
                }

                start_spf_holdtimer(conf);
                break;
        case SPF_HOLD:
                conf->spf_state = SPF_IDLE;
                break;
        default:
                fatalx("spf_timer: unknown state");
        }
}

void
start_spf_timer(void)
{
        struct timeval  tv;

        switch (rdeconf->spf_state) {
        case SPF_IDLE:
                timerclear(&tv);
                tv.tv_sec = rdeconf->spf_delay / 1000;
                tv.tv_usec = (rdeconf->spf_delay % 1000) * 1000;
                rdeconf->spf_state = SPF_DELAY;
                if (evtimer_add(&rdeconf->ev, &tv) == -1)
                        fatal("start_spf_timer");
                break;
        case SPF_DELAY:
                /* ignore */
                break;
        case SPF_HOLD:
                rdeconf->spf_state = SPF_HOLDQUEUE;
                break;
        case SPF_HOLDQUEUE:
                /* ignore */
                break;
        default:
                fatalx("start_spf_timer: invalid spf_state");
        }
}

void
stop_spf_timer(struct ospfd_conf *conf)
{
        if (evtimer_del(&conf->ev) == -1)
                fatal("stop_spf_timer");
}

void
start_spf_holdtimer(struct ospfd_conf *conf)
{
        struct timeval  tv;

        switch (conf->spf_state) {
        case SPF_DELAY:
                timerclear(&tv);
                tv.tv_sec = rdeconf->spf_hold_time / 1000;
                tv.tv_usec = (rdeconf->spf_hold_time % 1000) * 1000;
                conf->spf_state = SPF_HOLD;
                if (evtimer_add(&conf->ev, &tv) == -1)
                        fatal("start_spf_holdtimer");
                break;
        case SPF_IDLE:
        case SPF_HOLD:
        case SPF_HOLDQUEUE:
                fatalx("start_spf_holdtimer: invalid state");
        default:
                fatalx("start_spf_holdtimer: unknown state");
        }
}

/* route table */
void
rt_init(void)
{
        RB_INIT(&rt);
}

int
rt_compare(struct rt_node *a, struct rt_node *b)
{
        if (ntohl(a->prefix.s_addr) < ntohl(b->prefix.s_addr))
                return (-1);
        if (ntohl(a->prefix.s_addr) > ntohl(b->prefix.s_addr))
                return (1);
        if (a->prefixlen < b->prefixlen)
                return (-1);
        if (a->prefixlen > b->prefixlen)
                return (1);
        if (a->d_type > b->d_type)
                return (-1);
        if (a->d_type < b->d_type)
                return (1);
        return (0);
}

struct rt_node *
rt_find(in_addr_t prefix, u_int8_t prefixlen, enum dst_type d_type)
{
        struct rt_node  s;

        s.prefix.s_addr = prefix;
        s.prefixlen = prefixlen;
        s.d_type = d_type;

        return (RB_FIND(rt_tree, &rt, &s));
}

int
rt_insert(struct rt_node *r)
{
        if (RB_INSERT(rt_tree, &rt, r) != NULL) {
                log_warnx("rt_insert failed for %s/%u",
                    inet_ntoa(r->prefix), r->prefixlen);
                free(r);
                return (-1);
        }

        return (0);
}

int
rt_remove(struct rt_node *r)
{
        if (RB_REMOVE(rt_tree, &rt, r) == NULL) {
                log_warnx("rt_remove failed for %s/%u",
                    inet_ntoa(r->prefix), r->prefixlen);
                return (-1);
        }

        rt_nexthop_clear(r);
        free(r);
        return (0);
}

void
rt_invalidate(struct area *area)
{
        struct rt_node          *r, *nr;
        struct rt_nexthop       *rn, *nrn;

        for (r = RB_MIN(rt_tree, &rt); r != NULL; r = nr) {
                nr = RB_NEXT(rt_tree, &rt, r);
                if (area == NULL) {
                        /* look only at as_ext routes */
                        if (r->p_type != PT_TYPE1_EXT &&
                            r->p_type != PT_TYPE2_EXT)
                                continue;
                } else {
                        /* ignore all as_ext routes */
                        if (r->p_type == PT_TYPE1_EXT ||
                            r->p_type == PT_TYPE2_EXT)
                                continue;

                        /* look only at routes matching the area */
                        if (r->area.s_addr != area->id.s_addr)
                                continue;
                }
                r->invalid = 1;
                for (rn = TAILQ_FIRST(&r->nexthop); rn != NULL; rn = nrn) {
                        nrn = TAILQ_NEXT(rn, entry);
                        if (rn->invalid) {
                                TAILQ_REMOVE(&r->nexthop, rn, entry);
                                free(rn);
                        } else
                                rn->invalid = 1;
                }
                if (TAILQ_EMPTY(&r->nexthop))
                        rt_remove(r);
        }
}

void
rt_nexthop_clear(struct rt_node *r)
{
        struct rt_nexthop       *rn;

        while ((rn = TAILQ_FIRST(&r->nexthop)) != NULL) {
                TAILQ_REMOVE(&r->nexthop, rn, entry);
                free(rn);
        }
}

void
rt_nexthop_add(struct rt_node *r, struct v_nexthead *vnh, u_int8_t type,
    struct in_addr adv_rtr)
{
        struct v_nexthop        *vn;
        struct rt_nexthop       *rn;
        struct timespec          now;

        TAILQ_FOREACH(vn, vnh, entry) {
                TAILQ_FOREACH(rn, &r->nexthop, entry) {
                        if (rn->nexthop.s_addr != vn->nexthop.s_addr)
                                continue;

                        rn->adv_rtr.s_addr = adv_rtr.s_addr;
                        rn->connected = (type == LSA_TYPE_NETWORK &&
                            vn->prev == spf_root) || (vn->nexthop.s_addr == 0);
                        rn->invalid = 0;

                        r->invalid = 0;
                        break;
                }
                if (rn)
                        continue;

                if ((rn = calloc(1, sizeof(struct rt_nexthop))) == NULL)
                        fatal("rt_nexthop_add");

                clock_gettime(CLOCK_MONOTONIC, &now);
                rn->nexthop.s_addr = vn->nexthop.s_addr;
                rn->adv_rtr.s_addr = adv_rtr.s_addr;
                rn->uptime = now.tv_sec;
                rn->connected = (type == LSA_TYPE_NETWORK &&
                    vn->prev == spf_root) || (vn->nexthop.s_addr == 0);
                rn->invalid = 0;

                r->invalid = 0;
                TAILQ_INSERT_TAIL(&r->nexthop, rn, entry);
        }
}

void
rt_clear(void)
{
        struct rt_node  *r;

        while ((r = RB_MIN(rt_tree, &rt)) != NULL)
                rt_remove(r);
}

void
rt_dump(struct in_addr area, pid_t pid, u_int8_t r_type)
{
        static struct ctl_rt     rtctl;
        struct timespec          now;
        struct rt_node          *r;
        struct rt_nexthop       *rn;

        clock_gettime(CLOCK_MONOTONIC, &now);

        RB_FOREACH(r, rt_tree, &rt) {
                if (r->invalid)
                        continue;

                if (r->area.s_addr != area.s_addr)
                        continue;

                switch (r_type) {
                case RIB_RTR:
                        if (r->d_type != DT_RTR)
                                continue;
                        break;
                case RIB_NET:
                        if (r->d_type != DT_NET)
                                continue;
                        if (r->p_type == PT_TYPE1_EXT ||
                            r->p_type == PT_TYPE2_EXT)
                                continue;
                        break;
                case RIB_EXT:
                        if (r->p_type != PT_TYPE1_EXT &&
                            r->p_type != PT_TYPE2_EXT)
                                continue;
                        break;
                default:
                        fatalx("rt_dump: invalid RIB type");
                }

                bzero(&rtctl, sizeof(rtctl));
                rtctl.prefix.s_addr = r->prefix.s_addr;
                rtctl.area.s_addr = r->area.s_addr;
                rtctl.cost = r->cost;
                rtctl.cost2 = r->cost2;
                rtctl.p_type = r->p_type;
                rtctl.d_type = r->d_type;
                rtctl.flags = r->flags;
                rtctl.prefixlen = r->prefixlen;

                TAILQ_FOREACH(rn, &r->nexthop, entry) {
                        if (rn->invalid)
                                continue;

                        rtctl.connected = rn->connected;
                        rtctl.nexthop.s_addr = rn->nexthop.s_addr;
                        rtctl.adv_rtr.s_addr = rn->adv_rtr.s_addr;
                        rtctl.uptime = now.tv_sec - rn->uptime;

                        rde_imsg_compose_ospfe(IMSG_CTL_SHOW_RIB, 0, pid,
                            &rtctl, sizeof(rtctl));
                }
        }
}

void
rt_update(struct in_addr prefix, u_int8_t prefixlen, struct v_nexthead *vnh,
     u_int8_t v_type, u_int32_t cost, u_int32_t cost2, struct in_addr area,
     struct in_addr adv_rtr, enum path_type p_type, enum dst_type d_type,
     u_int8_t flags, u_int32_t tag)
{
        struct rt_node          *rte;
        struct rt_nexthop       *rn;
        int                      better = 0, equal = 0;

        if ((rte = rt_find(prefix.s_addr, prefixlen, d_type)) == NULL) {
                if ((rte = calloc(1, sizeof(struct rt_node))) == NULL)
                        fatal("rt_update");

                TAILQ_INIT(&rte->nexthop);
                rte->prefix.s_addr = prefix.s_addr;
                rte->prefixlen = prefixlen;
                rte->cost = cost;
                rte->cost2 = cost2;
                rte->area = area;
                rte->p_type = p_type;
                rte->d_type = d_type;
                rte->flags = flags;
                rte->ext_tag = tag;

                rt_nexthop_add(rte, vnh, v_type, adv_rtr);

                rt_insert(rte);
        } else {
                /* order:
                 * 1. intra-area
                 * 2. inter-area
                 * 3. type 1 as ext
                 * 4. type 2 as ext
                 */
                if (rte->invalid)       /* everything is better than invalid */
                        better = 1;
                else if (p_type < rte->p_type)
                        better = 1;
                else if (p_type == rte->p_type)
                        switch (p_type) {
                        case PT_INTRA_AREA:
                        case PT_INTER_AREA:
                                if (cost < rte->cost)
                                        better = 1;
                                else if (cost == rte->cost &&
                                    rte->area.s_addr == area.s_addr)
                                        equal = 1;
                                break;
                        case PT_TYPE1_EXT:
                                /* XXX rfc1583 compat */
                                if (cost < rte->cost)
                                        better = 1;
                                else if (cost == rte->cost)
                                        equal = 1;
                                break;
                        case PT_TYPE2_EXT:
                                if (cost2 < rte->cost2)
                                        better = 1;
                                /* XXX rfc1583 compat */
                                else if (cost2 == rte->cost2 &&
                                    cost < rte->cost)
                                        better = 1;
                                else if (cost2 == rte->cost2 &&
                                    cost == rte->cost)
                                        equal = 1;
                                break;
                        }

                if (better) {
                        TAILQ_FOREACH(rn, &rte->nexthop, entry)
                                rn->invalid = 1;

                        rte->area = area;
                        rte->cost = cost;
                        rte->cost2 = cost2;
                        rte->p_type = p_type;
                        rte->flags = flags;
                        rte->ext_tag = tag;
                }

                if (equal || better)
                        rt_nexthop_add(rte, vnh, v_type, adv_rtr);
        }
}

struct rt_node *
rt_lookup(enum dst_type type, in_addr_t addr)
{
        struct rt_node  *rn;
        u_int8_t         i = 32;

        if (type == DT_RTR) {
                rn = rt_find(addr, 32, type);
                if (rn && rn->invalid == 0)
                        return (rn);
                return (NULL);
        }

        /* type == DT_NET */
        do {
                if ((rn = rt_find(addr & prefixlen2mask(i), i, type)) &&
                    rn->invalid == 0)
                        return (rn);
        } while (i-- != 0);

        return (NULL);
}

/* router LSA links */
struct lsa_rtr_link *
get_rtr_link(struct vertex *v, int idx)
{
        struct lsa_rtr_link     *rtr_link = NULL;
        char                    *buf = (char *)v->lsa;
        u_int16_t                i, off, nlinks;

        if (v->type != LSA_TYPE_ROUTER)
                fatalx("get_rtr_link: invalid LSA type");

        off = sizeof(v->lsa->hdr) + sizeof(struct lsa_rtr);

        /* nlinks validated earlier by lsa_check() */
        nlinks = lsa_num_links(v);
        for (i = 0; i < nlinks; i++) {
                rtr_link = (struct lsa_rtr_link *)(buf + off);
                if (i == idx)
                        return (rtr_link);

                off += sizeof(struct lsa_rtr_link) +
                    rtr_link->num_tos * sizeof(u_int32_t);
        }

        fatalx("get_rtr_link: index not found");
}

/* network LSA links */
struct lsa_net_link *
get_net_link(struct vertex *v, int idx)
{
        struct lsa_net_link     *net_link = NULL;
        char                    *buf = (char *)v->lsa;
        u_int16_t                i, off, nlinks;

        if (v->type != LSA_TYPE_NETWORK)
                fatalx("get_net_link: invalid LSA type");

        off = sizeof(v->lsa->hdr) + sizeof(u_int32_t);

        /* nlinks validated earlier by lsa_check() */
        nlinks = lsa_num_links(v);
        for (i = 0; i < nlinks; i++) {
                net_link = (struct lsa_net_link *)(buf + off);
                if (i == idx)
                        return (net_link);

                off += sizeof(struct lsa_net_link);
        }

        fatalx("get_net_link: index not found");
}

/* misc */
int
linked(struct vertex *w, struct vertex *v)
{
        struct lsa_rtr_link     *rtr_link = NULL;
        struct lsa_net_link     *net_link = NULL;
        int                      i;

        switch (w->type) {
        case LSA_TYPE_ROUTER:
                for (i = 0; i < lsa_num_links(w); i++) {
                        rtr_link = get_rtr_link(w, i);
                        switch (v->type) {
                        case LSA_TYPE_ROUTER:
                                if (rtr_link->type == LINK_TYPE_POINTTOPOINT &&
                                    rtr_link->id == htonl(v->ls_id))
                                        return (1);
                                break;
                        case LSA_TYPE_NETWORK:
                                if (rtr_link->id == htonl(v->ls_id))
                                        return (1);
                                break;
                        default:
                                fatalx("linked: invalid type");
                        }
                }
                return (0);
        case LSA_TYPE_NETWORK:
                for (i = 0; i < lsa_num_links(w); i++) {
                        net_link = get_net_link(w, i);
                        switch (v->type) {
                        case LSA_TYPE_ROUTER:
                                if (net_link->att_rtr == htonl(v->ls_id))
                                        return (1);
                                break;
                        default:
                                fatalx("linked: invalid type");
                        }
                }
                return (0);
        default:
                fatalx("linked: invalid LSA type");
        }

        return (0);
}