/*      $OpenBSD: rde.c,v 1.120 2026/07/28 11:48:14 claudio Exp $ */

/*
 * Copyright (c) 2004, 2005 Claudio Jeker <claudio@openbsd.org>
 * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
 * Copyright (c) 2003, 2004 Henning Brauer <henning@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 <sys/queue.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <err.h>
#include <errno.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <pwd.h>
#include <unistd.h>
#include <event.h>

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

void             rde_sig_handler(int sig, short, void *);
__dead void      rde_shutdown(void);
void             rde_dispatch_imsg(int, short, void *);
void             rde_dispatch_parent(int, short, void *);
void             rde_dump_area(struct area *, int, pid_t);

void             rde_send_summary(pid_t);
void             rde_send_summary_area(struct area *, pid_t);
void             rde_nbr_init(u_int32_t);
void             rde_nbr_free(void);
struct rde_nbr  *rde_nbr_find(u_int32_t);
struct rde_nbr  *rde_nbr_new(u_int32_t, struct rde_nbr *);
void             rde_nbr_del(struct rde_nbr *);

void             rde_req_list_add(struct rde_nbr *, struct lsa_hdr *);
int              rde_req_list_exists(struct rde_nbr *, struct lsa_hdr *);
void             rde_req_list_del(struct rde_nbr *, struct lsa_hdr *);
void             rde_req_list_free(struct rde_nbr *);

struct iface    *rde_asext_lookup(u_int32_t, int);
void             rde_asext_get(struct kroute *);
void             rde_asext_put(struct kroute *);
void             rde_asext_free(void);
struct lsa      *orig_asext_lsa(struct kroute *, u_int32_t, u_int16_t);
struct lsa      *orig_sum_lsa(struct rt_node *, struct area *, u_int8_t, int);

struct ospfd_conf       *rdeconf = NULL, *nconf = NULL;
static struct imsgev    *iev_ospfe;
static struct imsgev    *iev_main;
struct rde_nbr          *nbrself;
struct lsa_tree          asext_tree;

void
rde_sig_handler(int sig, short event, void *arg)
{
        /*
         * signal handler rules don't apply, libevent decouples for us
         */

        switch (sig) {
        case SIGINT:
        case SIGTERM:
                rde_shutdown();
                /* NOTREACHED */
        default:
                fatalx("unexpected signal");
        }
}

/* route decision engine */
pid_t
rde(struct ospfd_conf *xconf, int pipe_parent2rde[2], int pipe_ospfe2rde[2],
    int pipe_parent2ospfe[2])
{
        struct event             ev_sigint, ev_sigterm;
        struct timeval           now;
        struct area             *area;
        struct iface            *iface;
        struct passwd           *pw;
        pid_t                    pid;

        switch (pid = fork()) {
        case -1:
                fatal("cannot fork");
                /* NOTREACHED */
        case 0:
                break;
        default:
                return (pid);
        }

        /* cleanup a bit */
        kif_clear();

        rdeconf = xconf;

        if ((pw = getpwnam(OSPFD_USER)) == NULL)
                fatal("getpwnam");

        if (chroot(pw->pw_dir) == -1)
                fatal("chroot");
        if (chdir("/") == -1)
                fatal("chdir(\"/\")");

        setproctitle("route decision engine");
        /*
         * XXX needed with fork+exec
         * log_init(debug, LOG_DAEMON);
         * log_setverbose(verbose);
         */

        ospfd_process = PROC_RDE_ENGINE;
        log_procinit(log_procnames[ospfd_process]);

        if (setgroups(1, &pw->pw_gid) ||
            setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
            setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
                fatal("can't drop privileges");

        if (pledge("stdio", NULL) == -1)
                fatal("pledge");

        event_init();
        rde_nbr_init(NBR_HASHSIZE);
        lsa_init(&asext_tree);

        /* setup signal handler */
        signal_set(&ev_sigint, SIGINT, rde_sig_handler, NULL);
        signal_set(&ev_sigterm, SIGTERM, rde_sig_handler, NULL);
        signal_add(&ev_sigint, NULL);
        signal_add(&ev_sigterm, NULL);
        signal(SIGPIPE, SIG_IGN);
        signal(SIGHUP, SIG_IGN);

        /* setup pipes */
        close(pipe_ospfe2rde[0]);
        close(pipe_parent2rde[0]);
        close(pipe_parent2ospfe[0]);
        close(pipe_parent2ospfe[1]);

        if ((iev_ospfe = malloc(sizeof(struct imsgev))) == NULL ||
            (iev_main = malloc(sizeof(struct imsgev))) == NULL)
                fatal(NULL);
        if (imsgbuf_init(&iev_ospfe->ibuf, pipe_ospfe2rde[1]) == -1)
                fatal(NULL);
        iev_ospfe->handler = rde_dispatch_imsg;
        if (imsgbuf_init(&iev_main->ibuf, pipe_parent2rde[1]) == -1)
                fatal(NULL);
        iev_main->handler = rde_dispatch_parent;

        /* setup event handler */
        iev_ospfe->events = EV_READ;
        event_set(&iev_ospfe->ev, iev_ospfe->ibuf.fd, iev_ospfe->events,
            iev_ospfe->handler, iev_ospfe);
        event_add(&iev_ospfe->ev, NULL);

        iev_main->events = EV_READ;
        event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events,
            iev_main->handler, iev_main);
        event_add(&iev_main->ev, NULL);

        evtimer_set(&rdeconf->ev, spf_timer, rdeconf);
        cand_list_init();
        rt_init();

        /* remove unneeded stuff from config */
        LIST_FOREACH(area, &rdeconf->area_list, entry)
                LIST_FOREACH(iface, &area->iface_list, entry)
                        md_list_clr(&iface->auth_md_list);

        conf_clear_redist_list(&rdeconf->redist_list);

        gettimeofday(&now, NULL);
        rdeconf->uptime = now.tv_sec;

        event_dispatch();

        rde_shutdown();
        /* NOTREACHED */

        return (0);
}

__dead void
rde_shutdown(void)
{
        struct area     *a;
        struct vertex   *v, *nv;

        /* close pipes */
        imsgbuf_clear(&iev_ospfe->ibuf);
        close(iev_ospfe->ibuf.fd);
        imsgbuf_clear(&iev_main->ibuf);
        close(iev_main->ibuf.fd);

        stop_spf_timer(rdeconf);
        cand_list_clr();
        rt_clear();

        while ((a = LIST_FIRST(&rdeconf->area_list)) != NULL) {
                LIST_REMOVE(a, entry);
                area_del(a);
        }
        for (v = RB_MIN(lsa_tree, &asext_tree); v != NULL; v = nv) {
                nv = RB_NEXT(lsa_tree, &asext_tree, v);
                vertex_free(v);
        }
        rde_asext_free();
        rde_nbr_free();

        free(iev_ospfe);
        free(iev_main);
        free(rdeconf);

        log_info("route decision engine exiting");
        _exit(0);
}

int
rde_imsg_compose_ospfe(int type, u_int32_t peerid, pid_t pid, void *data,
    u_int16_t datalen)
{
        return (imsg_compose_event(iev_ospfe, type, peerid, pid, -1,
            data, datalen));
}

void
rde_dispatch_imsg(int fd, short event, void *bula)
{
        struct imsgev           *iev = bula;
        struct imsgbuf          *ibuf;
        struct imsg              imsg;
        struct in_addr           aid;
        struct ls_req_hdr        req_hdr;
        struct lsa_hdr           lsa_hdr, *db_hdr;
        struct rde_nbr           rn, *nbr;
        struct timespec          tp;
        struct lsa              *lsa;
        struct area             *area;
        struct in_addr           addr;
        struct vertex           *v;
        char                    *buf;
        ssize_t                  n;
        time_t                   now;
        int                      r, state, self, error, shut = 0, verbose;
        u_int16_t                l;

        ibuf = &iev->ibuf;

        if (event & EV_READ) {
                if ((n = imsgbuf_read(ibuf)) == -1)
                        fatal("imsgbuf_read error");
                if (n == 0)     /* connection closed */
                        shut = 1;
        }
        if (event & EV_WRITE) {
                if (imsgbuf_write(ibuf) == -1) {
                        if (errno == EPIPE)     /* connection closed */
                                shut = 1;
                        else
                                fatal("imsgbuf_write");
                }
        }

        clock_gettime(CLOCK_MONOTONIC, &tp);
        now = tp.tv_sec;

        for (;;) {
                if ((n = imsgbuf_get(ibuf, &imsg)) == -1)
                        fatal("rde_dispatch_imsg: imsgbuf_get error");
                if (n == 0)
                        break;

                switch (imsg.hdr.type) {
                case IMSG_NEIGHBOR_UP:
                        if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(rn))
                                fatalx("invalid size of OE request");
                        memcpy(&rn, imsg.data, sizeof(rn));

                        if (rde_nbr_new(imsg.hdr.peerid, &rn) == NULL)
                                fatalx("rde_dispatch_imsg: "
                                    "neighbor already exists");
                        break;
                case IMSG_NEIGHBOR_DOWN:
                        rde_nbr_del(rde_nbr_find(imsg.hdr.peerid));
                        break;
                case IMSG_NEIGHBOR_ADDR:
                        if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(addr))
                                fatalx("invalid size of OE request");
                        memcpy(&addr, imsg.data, sizeof(addr));

                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;

                        nbr->addr.s_addr = addr.s_addr;
                        break;
                case IMSG_NEIGHBOR_CHANGE:
                        if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(state))
                                fatalx("invalid size of OE request");
                        memcpy(&state, imsg.data, sizeof(state));

                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;

                        nbr->state = state;
                        if (nbr->state & NBR_STA_FULL)
                                rde_req_list_free(nbr);
                        break;
                case IMSG_NEIGHBOR_CAPA:
                        if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(u_int8_t))
                                fatalx("invalid size of OE request");
                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;
                        nbr->capa_options = *(u_int8_t *)imsg.data;
                        break;
                case IMSG_AREA_CHANGE:
                        if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(state))
                                fatalx("invalid size of OE request");

                        LIST_FOREACH(area, &rdeconf->area_list, entry) {
                                if (area->id.s_addr == imsg.hdr.peerid)
                                        break;
                        }
                        if (area == NULL)
                                break;
                        memcpy(&state, imsg.data, sizeof(state));
                        area->active = state;
                        break;
                case IMSG_DB_SNAPSHOT:
                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;

                        lsa_snap(nbr);

                        imsg_compose_event(iev_ospfe, IMSG_DB_END, imsg.hdr.peerid,
                            0, -1, NULL, 0);
                        break;
                case IMSG_DD:
                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;

                        buf = imsg.data;
                        error = 0;
                        for (l = imsg.hdr.len - IMSG_HEADER_SIZE;
                            l >= sizeof(lsa_hdr); l -= sizeof(lsa_hdr)) {
                                memcpy(&lsa_hdr, buf, sizeof(lsa_hdr));
                                buf += sizeof(lsa_hdr);

                                if (lsa_hdr.type == LSA_TYPE_EXTERNAL &&
                                    nbr->area->stub) {
                                        error = 1;
                                        break;
                                }
                                v = lsa_find(nbr->iface, lsa_hdr.type,
                                    lsa_hdr.ls_id, lsa_hdr.adv_rtr);
                                if (v == NULL)
                                        db_hdr = NULL;
                                else
                                        db_hdr = &v->lsa->hdr;

                                if (lsa_newer(&lsa_hdr, db_hdr) > 0) {
                                        /*
                                         * only request LSAs that are
                                         * newer or missing
                                         */
                                        rde_req_list_add(nbr, &lsa_hdr);
                                        imsg_compose_event(iev_ospfe, IMSG_DD,
                                            imsg.hdr.peerid, 0, -1, &lsa_hdr,
                                            sizeof(lsa_hdr));
                                }
                        }
                        if (l != 0 && !error)
                                log_warnx("rde_dispatch_imsg: peerid %u, "
                                    "trailing garbage in Database Description "
                                    "packet", imsg.hdr.peerid);

                        if (!error)
                                imsg_compose_event(iev_ospfe, IMSG_DD_END,
                                    imsg.hdr.peerid, 0, -1, NULL, 0);
                        else
                                imsg_compose_event(iev_ospfe, IMSG_DD_BADLSA,
                                    imsg.hdr.peerid, 0, -1, NULL, 0);
                        break;
                case IMSG_LS_REQ:
                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;

                        buf = imsg.data;
                        for (l = imsg.hdr.len - IMSG_HEADER_SIZE;
                            l >= sizeof(req_hdr); l -= sizeof(req_hdr)) {
                                memcpy(&req_hdr, buf, sizeof(req_hdr));
                                buf += sizeof(req_hdr);

                                if ((v = lsa_find(nbr->iface,
                                    ntohl(req_hdr.type), req_hdr.ls_id,
                                    req_hdr.adv_rtr)) == NULL) {
                                        log_debug("rde_dispatch_imsg: "
                                            "requested LSA not found");
                                        imsg_compose_event(iev_ospfe,
                                            IMSG_LS_BADREQ, imsg.hdr.peerid,
                                            0, -1, NULL, 0);
                                        continue;
                                }
                                imsg_compose_event(iev_ospfe, IMSG_LS_UPD,
                                    imsg.hdr.peerid, 0, -1, v->lsa,
                                    ntohs(v->lsa->hdr.len));
                        }
                        if (l != 0)
                                log_warnx("rde_dispatch_imsg: peerid %u, "
                                    "trailing garbage in LS Request "
                                    "packet", imsg.hdr.peerid);
                        break;
                case IMSG_LS_UPD:
                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;

                        lsa = malloc(imsg.hdr.len - IMSG_HEADER_SIZE);
                        if (lsa == NULL)
                                fatal(NULL);
                        memcpy(lsa, imsg.data, imsg.hdr.len - IMSG_HEADER_SIZE);

                        if (!lsa_check(nbr, lsa,
                            imsg.hdr.len - IMSG_HEADER_SIZE)) {
                                free(lsa);
                                break;
                        }

                        v = lsa_find(nbr->iface, lsa->hdr.type, lsa->hdr.ls_id,
                            lsa->hdr.adv_rtr);
                        if (v == NULL)
                                db_hdr = NULL;
                        else
                                db_hdr = &v->lsa->hdr;

                        if (nbr->self) {
                                lsa_merge(nbr, lsa, v);
                                /* lsa_merge frees the right lsa */
                                break;
                        }

                        r = lsa_newer(&lsa->hdr, db_hdr);
                        if (r > 0) {
                                /* new LSA newer than DB */
                                if (v && v->flooded &&
                                    v->changed + MIN_LS_ARRIVAL >= now) {
                                        free(lsa);
                                        break;
                                }

                                rde_req_list_del(nbr, &lsa->hdr);

                                if (!(self = lsa_self(nbr, lsa, v)))
                                        if (lsa_add(nbr, lsa))
                                                /* delayed lsa */
                                                break;

                                /* flood and perhaps ack LSA */
                                imsg_compose_event(iev_ospfe, IMSG_LS_FLOOD,
                                    imsg.hdr.peerid, 0, -1, lsa,
                                    ntohs(lsa->hdr.len));

                                /* reflood self originated LSA */
                                if (self && v)
                                        imsg_compose_event(iev_ospfe,
                                            IMSG_LS_FLOOD, v->peerid, 0, -1,
                                            v->lsa, ntohs(v->lsa->hdr.len));
                                /* new LSA was not added so free it */
                                if (self)
                                        free(lsa);
                        } else if (r < 0) {
                                /*
                                 * point 6 of "The Flooding Procedure"
                                 * We are violating the RFC here because
                                 * it does not make sense to reset a session
                                 * because an equal LSA is already in the table.
                                 * Only if the LSA sent is older than the one
                                 * in the table we should reset the session.
                                 */
                                if (rde_req_list_exists(nbr, &lsa->hdr)) {
                                        imsg_compose_event(iev_ospfe,
                                            IMSG_LS_BADREQ, imsg.hdr.peerid,
                                            0, -1, NULL, 0);
                                        free(lsa);
                                        break;
                                }

                                /* lsa no longer needed */
                                free(lsa);

                                /* new LSA older than DB */
                                if (ntohl(db_hdr->seq_num) == MAX_SEQ_NUM &&
                                    ntohs(db_hdr->age) == MAX_AGE)
                                        /* seq-num wrap */
                                        break;

                                if (v->changed + MIN_LS_ARRIVAL >= now)
                                        break;

                                /* directly send current LSA, no ack */
                                imsg_compose_event(iev_ospfe, IMSG_LS_UPD,
                                    imsg.hdr.peerid, 0, -1, v->lsa,
                                    ntohs(v->lsa->hdr.len));
                        } else {
                                /* LSA equal send direct ack */
                                imsg_compose_event(iev_ospfe, IMSG_LS_ACK,
                                    imsg.hdr.peerid, 0, -1, &lsa->hdr,
                                    sizeof(lsa->hdr));
                                free(lsa);
                        }
                        break;
                case IMSG_LS_MAXAGE:
                        nbr = rde_nbr_find(imsg.hdr.peerid);
                        if (nbr == NULL)
                                break;

                        if (imsg.hdr.len != IMSG_HEADER_SIZE +
                            sizeof(struct lsa_hdr))
                                fatalx("invalid size of OE request");
                        memcpy(&lsa_hdr, imsg.data, sizeof(lsa_hdr));

                        if (rde_nbr_loading(nbr->area))
                                break;

                        v = lsa_find(nbr->iface, lsa_hdr.type, lsa_hdr.ls_id,
                            lsa_hdr.adv_rtr);
                        if (v == NULL)
                                db_hdr = NULL;
                        else
                                db_hdr = &v->lsa->hdr;

                        /*
                         * only delete LSA if the one in the db is not newer
                         */
                        if (lsa_newer(db_hdr, &lsa_hdr) <= 0)
                                lsa_del(nbr, &lsa_hdr);
                        break;
                case IMSG_CTL_SHOW_DATABASE:
                case IMSG_CTL_SHOW_DB_EXT:
                case IMSG_CTL_SHOW_DB_NET:
                case IMSG_CTL_SHOW_DB_RTR:
                case IMSG_CTL_SHOW_DB_SELF:
                case IMSG_CTL_SHOW_DB_SUM:
                case IMSG_CTL_SHOW_DB_ASBR:
                case IMSG_CTL_SHOW_DB_OPAQ:
                        if (imsg.hdr.len != IMSG_HEADER_SIZE &&
                            imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(aid)) {
                                log_warnx("rde_dispatch_imsg: wrong imsg len");
                                break;
                        }
                        if (imsg.hdr.len == IMSG_HEADER_SIZE) {
                                LIST_FOREACH(area, &rdeconf->area_list, entry) {
                                        rde_dump_area(area, imsg.hdr.type,
                                            imsg.hdr.pid);
                                }
                                lsa_dump(&asext_tree, imsg.hdr.type,
                                    imsg.hdr.pid);
                        } else {
                                memcpy(&aid, imsg.data, sizeof(aid));
                                if ((area = area_find(rdeconf, aid)) != NULL) {
                                        rde_dump_area(area, imsg.hdr.type,
                                            imsg.hdr.pid);
                                        if (!area->stub)
                                                lsa_dump(&asext_tree,
                                                    imsg.hdr.type,
                                                    imsg.hdr.pid);
                                }
                        }
                        imsg_compose_event(iev_ospfe, IMSG_CTL_END, 0,
                            imsg.hdr.pid, -1, NULL, 0);
                        break;
                case IMSG_CTL_SHOW_RIB:
                        LIST_FOREACH(area, &rdeconf->area_list, entry) {
                                imsg_compose_event(iev_ospfe, IMSG_CTL_AREA,
                                    0, imsg.hdr.pid, -1,
                                    area_txsan(area), sizeof(*area));

                                rt_dump(area->id, imsg.hdr.pid, RIB_RTR);
                                rt_dump(area->id, imsg.hdr.pid, RIB_NET);
                        }
                        aid.s_addr = 0;
                        rt_dump(aid, imsg.hdr.pid, RIB_EXT);

                        imsg_compose_event(iev_ospfe, IMSG_CTL_END, 0,
                            imsg.hdr.pid, -1, NULL, 0);
                        break;
                case IMSG_CTL_SHOW_SUM:
                        rde_send_summary(imsg.hdr.pid);
                        LIST_FOREACH(area, &rdeconf->area_list, entry)
                                rde_send_summary_area(area, imsg.hdr.pid);
                        imsg_compose_event(iev_ospfe, IMSG_CTL_END, 0,
                            imsg.hdr.pid, -1, NULL, 0);
                        break;
                case IMSG_CTL_LOG_VERBOSE:
                        /* already checked by ospfe */
                        memcpy(&verbose, imsg.data, sizeof(verbose));
                        log_setverbose(verbose);
                        break;
                default:
                        log_debug("rde_dispatch_imsg: unexpected imsg %d",
                            imsg.hdr.type);
                        break;
                }
                imsg_free(&imsg);
        }
        if (!shut)
                imsg_event_add(iev);
        else {
                /* this pipe is dead, so remove the event handler */
                event_del(&iev->ev);
                event_loopexit(NULL);
        }
}

void
rde_dispatch_parent(int fd, short event, void *bula)
{
        static struct area      *narea;
        struct iface            *niface;
        struct imsg              imsg;
        struct kroute            rr;
        struct imsgev           *iev = bula;
        struct imsgbuf          *ibuf;
        struct redistribute     *nred;
        ssize_t                  n;
        int                      shut = 0;

        ibuf = &iev->ibuf;

        if (event & EV_READ) {
                if ((n = imsgbuf_read(ibuf)) == -1)
                        fatal("imsgbuf_read error");
                if (n == 0)     /* connection closed */
                        shut = 1;
        }
        if (event & EV_WRITE) {
                if (imsgbuf_write(ibuf) == -1) {
                        if (errno == EPIPE)     /* connection closed */
                                shut = 1;
                        else
                                fatal("imsgbuf_write");
                }
        }

        for (;;) {
                if ((n = imsgbuf_get(ibuf, &imsg)) == -1)
                        fatal("rde_dispatch_parent: imsgbuf_get error");
                if (n == 0)
                        break;

                switch (imsg.hdr.type) {
                case IMSG_NETWORK_ADD:
                        if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(rr)) {
                                log_warnx("rde_dispatch_parent: "
                                    "wrong imsg len");
                                break;
                        }
                        memcpy(&rr, imsg.data, sizeof(rr));
                        rde_asext_get(&rr);
                        break;
                case IMSG_NETWORK_DEL:
                        if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(rr)) {
                                log_warnx("rde_dispatch_parent: "
                                    "wrong imsg len");
                                break;
                        }
                        memcpy(&rr, imsg.data, sizeof(rr));
                        rde_asext_put(&rr);
                        break;
                case IMSG_RECONF_CONF:
                        if ((nconf = malloc(sizeof(struct ospfd_conf))) ==
                            NULL)
                                fatal(NULL);
                        memcpy(nconf, imsg.data, sizeof(struct ospfd_conf));

                        LIST_INIT(&nconf->area_list);
                        LIST_INIT(&nconf->cand_list);
                        break;
                case IMSG_RECONF_AREA:
                        if ((narea = area_new()) == NULL)
                                fatal(NULL);
                        memcpy(narea, imsg.data, sizeof(struct area));

                        LIST_INIT(&narea->iface_list);
                        LIST_INIT(&narea->nbr_list);
                        RB_INIT(&narea->lsa_tree);
                        SIMPLEQ_INIT(&narea->redist_list);

                        LIST_INSERT_HEAD(&nconf->area_list, narea, entry);
                        break;
                case IMSG_RECONF_REDIST:
                        if ((nred= malloc(sizeof(struct redistribute))) == NULL)
                                fatal(NULL);
                        memcpy(nred, imsg.data, sizeof(struct redistribute));

                        SIMPLEQ_INSERT_TAIL(&narea->redist_list, nred, entry);
                        break;
                case IMSG_RECONF_IFACE:
                        if ((niface = malloc(sizeof(struct iface))) == NULL)
                                fatal(NULL);
                        memcpy(niface, imsg.data, sizeof(struct iface));

                        LIST_INIT(&niface->nbr_list);
                        TAILQ_INIT(&niface->ls_ack_list);
                        TAILQ_INIT(&niface->auth_md_list);
                        RB_INIT(&niface->lsa_tree);

                        niface->area = narea;
                        LIST_INSERT_HEAD(&narea->iface_list, niface, entry);

                        break;
                case IMSG_RECONF_END:
                        merge_config(rdeconf, nconf);
                        nconf = NULL;
                        break;
                default:
                        log_debug("rde_dispatch_parent: unexpected imsg %d",
                            imsg.hdr.type);
                        break;
                }
                imsg_free(&imsg);
        }
        if (!shut)
                imsg_event_add(iev);
        else {
                /* this pipe is dead, so remove the event handler */
                event_del(&iev->ev);
                event_loopexit(NULL);
        }
}

void
rde_dump_area(struct area *area, int imsg_type, pid_t pid)
{
        struct iface    *iface;

        imsg_compose_event(iev_ospfe, IMSG_CTL_AREA, 0, pid, -1, &area->id,
            sizeof(area->id));

        /* dump link local lsa */
        LIST_FOREACH(iface, &area->iface_list, entry) {
                imsg_compose_event(iev_ospfe, IMSG_CTL_IFACE,
                    0, pid, -1, iface->name, sizeof(iface->name));
                lsa_dump(&iface->lsa_tree, imsg_type, pid);
        }

        /* dump area lsa */
        lsa_dump(&area->lsa_tree, imsg_type, pid);
}

u_int32_t
rde_router_id(void)
{
        return (rdeconf->rtr_id.s_addr);
}

struct area *
rde_backbone_area(void)
{
        struct in_addr  id;

        id.s_addr = INADDR_ANY;

        return (area_find(rdeconf, id));
}

void
rde_send_change_kroute(struct rt_node *r)
{
        int                      krcount = 0;
        struct kroute            kr;
        struct rt_nexthop       *rn;
        struct ibuf             *wbuf;

        if ((wbuf = imsg_create(&iev_main->ibuf, IMSG_KROUTE_CHANGE, 0, 0,
            sizeof(kr))) == NULL) {
                return;
        }

        TAILQ_FOREACH(rn, &r->nexthop, entry) {
                if (rn->invalid)
                        continue;
                if (rn->connected)
                        /* skip self-originated routes */
                        continue;
                krcount++;

                bzero(&kr, sizeof(kr));
                kr.prefix.s_addr = r->prefix.s_addr;
                kr.nexthop.s_addr = rn->nexthop.s_addr;
                kr.prefixlen = r->prefixlen;
                kr.ext_tag = r->ext_tag;
                imsg_add(wbuf, &kr, sizeof(kr));
        }
        if (krcount == 0) {
                /* no valid nexthop or self originated, so remove */
                ibuf_free(wbuf);
                rde_send_delete_kroute(r);
                return;
        }
        imsg_close(&iev_main->ibuf, wbuf);
        imsg_event_add(iev_main);
}

void
rde_send_delete_kroute(struct rt_node *r)
{
        struct kroute    kr;

        bzero(&kr, sizeof(kr));
        kr.prefix.s_addr = r->prefix.s_addr;
        kr.prefixlen = r->prefixlen;

        imsg_compose_event(iev_main, IMSG_KROUTE_DELETE, 0, 0, -1,
            &kr, sizeof(kr));
}

void
rde_send_summary(pid_t pid)
{
        static struct ctl_sum    sumctl;
        struct timeval           now;
        struct area             *area;
        struct vertex           *v;

        bzero(&sumctl, sizeof(struct ctl_sum));

        sumctl.rtr_id.s_addr = rde_router_id();
        sumctl.spf_delay = rdeconf->spf_delay;
        sumctl.spf_hold_time = rdeconf->spf_hold_time;

        LIST_FOREACH(area, &rdeconf->area_list, entry)
                sumctl.num_area++;

        RB_FOREACH(v, lsa_tree, &asext_tree) {
                sumctl.num_ext_lsa++;
                sumctl.ext_lsa_cksum += ntohs(v->lsa->hdr.ls_chksum);
        }

        gettimeofday(&now, NULL);
        if (rdeconf->uptime < now.tv_sec)
                sumctl.uptime = now.tv_sec - rdeconf->uptime;
        else
                sumctl.uptime = 0;

        sumctl.rfc1583compat = rdeconf->rfc1583compat;

        rde_imsg_compose_ospfe(IMSG_CTL_SHOW_SUM, 0, pid, &sumctl,
            sizeof(sumctl));
}

void
rde_send_summary_area(struct area *area, pid_t pid)
{
        static struct ctl_sum_area       sumareactl;
        struct iface                    *iface;
        struct rde_nbr                  *nbr;
        struct lsa_tree                 *tree = &area->lsa_tree;
        struct vertex                   *v;

        bzero(&sumareactl, sizeof(struct ctl_sum_area));

        sumareactl.area.s_addr = area->id.s_addr;
        sumareactl.num_spf_calc = area->num_spf_calc;

        LIST_FOREACH(iface, &area->iface_list, entry)
                sumareactl.num_iface++;

        LIST_FOREACH(nbr, &area->nbr_list, entry)
                if (nbr->state == NBR_STA_FULL && !nbr->self)
                        sumareactl.num_adj_nbr++;

        RB_FOREACH(v, lsa_tree, tree) {
                sumareactl.num_lsa++;
                sumareactl.lsa_cksum += ntohs(v->lsa->hdr.ls_chksum);
        }

        rde_imsg_compose_ospfe(IMSG_CTL_SHOW_SUM_AREA, 0, pid, &sumareactl,
            sizeof(sumareactl));
}

LIST_HEAD(rde_nbr_head, rde_nbr);

struct nbr_table {
        struct rde_nbr_head     *hashtbl;
        u_int32_t                hashmask;
} rdenbrtable;

#define RDE_NBR_HASH(x)         \
        &rdenbrtable.hashtbl[(x) & rdenbrtable.hashmask]

void
rde_nbr_init(u_int32_t hashsize)
{
        struct rde_nbr_head     *head;
        u_int32_t                hs, i;

        for (hs = 1; hs < hashsize; hs <<= 1)
                ;
        rdenbrtable.hashtbl = calloc(hs, sizeof(struct rde_nbr_head));
        if (rdenbrtable.hashtbl == NULL)
                fatal("rde_nbr_init");

        for (i = 0; i < hs; i++)
                LIST_INIT(&rdenbrtable.hashtbl[i]);

        rdenbrtable.hashmask = hs - 1;

        if ((nbrself = calloc(1, sizeof(*nbrself))) == NULL)
                fatal("rde_nbr_init");

        nbrself->id.s_addr = rde_router_id();
        nbrself->peerid = NBR_IDSELF;
        nbrself->state = NBR_STA_DOWN;
        nbrself->self = 1;
        head = RDE_NBR_HASH(NBR_IDSELF);
        LIST_INSERT_HEAD(head, nbrself, hash);
}

void
rde_nbr_free(void)
{
        free(nbrself);
        free(rdenbrtable.hashtbl);
}

struct rde_nbr *
rde_nbr_find(u_int32_t peerid)
{
        struct rde_nbr_head     *head;
        struct rde_nbr          *nbr;

        head = RDE_NBR_HASH(peerid);

        LIST_FOREACH(nbr, head, hash) {
                if (nbr->peerid == peerid)
                        return (nbr);
        }

        return (NULL);
}

struct rde_nbr *
rde_nbr_new(u_int32_t peerid, struct rde_nbr *new)
{
        struct rde_nbr_head     *head;
        struct rde_nbr          *nbr;
        struct area             *area;
        struct iface            *iface;

        if (rde_nbr_find(peerid))
                return (NULL);
        if ((area = area_find(rdeconf, new->area_id)) == NULL)
                fatalx("rde_nbr_new: unknown area");

        LIST_FOREACH(iface, &area->iface_list, entry) {
                if (iface->ifindex == new->ifindex)
                        break;
        }
        if (iface == NULL)
                fatalx("rde_nbr_new: unknown interface");

        if ((nbr = calloc(1, sizeof(*nbr))) == NULL)
                fatal("rde_nbr_new");

        memcpy(nbr, new, sizeof(*nbr));
        nbr->peerid = peerid;
        nbr->area = area;
        nbr->iface = iface;

        TAILQ_INIT(&nbr->req_list);

        head = RDE_NBR_HASH(peerid);
        LIST_INSERT_HEAD(head, nbr, hash);
        LIST_INSERT_HEAD(&area->nbr_list, nbr, entry);

        return (nbr);
}

void
rde_nbr_iface_del(struct iface *iface)
{
        struct rde_nbr_head     *head;
        struct rde_nbr          *nbr, *xnbr;
        u_int32_t                i;

        for (i = 0; i <= rdenbrtable.hashmask; i++) {
                head = &rdenbrtable.hashtbl[i];
                LIST_FOREACH_SAFE(nbr, head, hash, xnbr) {
                        if (nbr->iface == iface)
                                rde_nbr_del(nbr);
                }
        }
}

void
rde_nbr_del(struct rde_nbr *nbr)
{
        if (nbr == NULL)
                return;

        rde_req_list_free(nbr);

        LIST_REMOVE(nbr, entry);
        LIST_REMOVE(nbr, hash);

        free(nbr);
}

int
rde_nbr_loading(struct area *area)
{
        struct rde_nbr          *nbr;
        int                      checkall = 0;

        if (area == NULL) {
                area = LIST_FIRST(&rdeconf->area_list);
                checkall = 1;
        }

        while (area != NULL) {
                LIST_FOREACH(nbr, &area->nbr_list, entry) {
                        if (nbr->self)
                                continue;
                        if (nbr->state & NBR_STA_XCHNG ||
                            nbr->state & NBR_STA_LOAD)
                                return (1);
                }
                if (!checkall)
                        break;
                area = LIST_NEXT(area, entry);
        }

        return (0);
}

struct rde_nbr *
rde_nbr_self(struct area *area)
{
        struct rde_nbr          *nbr;

        LIST_FOREACH(nbr, &area->nbr_list, entry)
                if (nbr->self)
                        return (nbr);

        /* this may not happen */
        fatalx("rde_nbr_self: area without self");
        return (NULL);
}

/*
 * LSA req list
 */
void
rde_req_list_add(struct rde_nbr *nbr, struct lsa_hdr *lsa)
{
        struct rde_req_entry    *le;

        if ((le = calloc(1, sizeof(*le))) == NULL)
                fatal("rde_req_list_add");

        TAILQ_INSERT_TAIL(&nbr->req_list, le, entry);
        le->type = lsa->type;
        le->ls_id = lsa->ls_id;
        le->adv_rtr = lsa->adv_rtr;
}

int
rde_req_list_exists(struct rde_nbr *nbr, struct lsa_hdr *lsa_hdr)
{
        struct rde_req_entry    *le;

        TAILQ_FOREACH(le, &nbr->req_list, entry) {
                if ((lsa_hdr->type == le->type) &&
                    (lsa_hdr->ls_id == le->ls_id) &&
                    (lsa_hdr->adv_rtr == le->adv_rtr))
                        return (1);
        }
        return (0);
}

void
rde_req_list_del(struct rde_nbr *nbr, struct lsa_hdr *lsa_hdr)
{
        struct rde_req_entry    *le;

        TAILQ_FOREACH(le, &nbr->req_list, entry) {
                if ((lsa_hdr->type == le->type) &&
                    (lsa_hdr->ls_id == le->ls_id) &&
                    (lsa_hdr->adv_rtr == le->adv_rtr)) {
                        TAILQ_REMOVE(&nbr->req_list, le, entry);
                        free(le);
                        return;
                }
        }
}

void
rde_req_list_free(struct rde_nbr *nbr)
{
        struct rde_req_entry    *le;

        while ((le = TAILQ_FIRST(&nbr->req_list)) != NULL) {
                TAILQ_REMOVE(&nbr->req_list, le, entry);
                free(le);
        }
}

/*
 * as-external LSA handling
 */
struct asext_node {
        RB_ENTRY(asext_node)    entry;
        struct kroute           r;
        u_int32_t               ls_id;
};

static __inline int     asext_compare(struct asext_node *, struct asext_node *);
struct asext_node       *asext_find(u_int32_t, u_int8_t);

RB_HEAD(asext_tree, asext_node)         ast;
RB_PROTOTYPE(asext_tree, asext_node, entry, asext_compare)
RB_GENERATE(asext_tree, asext_node, entry, asext_compare)

static __inline int
asext_compare(struct asext_node *a, struct asext_node *b)
{
        if (ntohl(a->r.prefix.s_addr) < ntohl(b->r.prefix.s_addr))
                return (-1);
        if (ntohl(a->r.prefix.s_addr) > ntohl(b->r.prefix.s_addr))
                return (1);
        if (a->r.prefixlen < b->r.prefixlen)
                return (-1);
        if (a->r.prefixlen > b->r.prefixlen)
                return (1);
        return (0);
}

struct asext_node *
asext_find(u_int32_t addr, u_int8_t prefixlen)
{
        struct asext_node       a;

        a.r.prefix.s_addr = addr;
        a.r.prefixlen = prefixlen;

        return (RB_FIND(asext_tree, &ast, &a));
}

struct iface *
rde_asext_lookup(u_int32_t prefix, int plen)
{
        struct area     *area;
        struct iface    *iface;

        LIST_FOREACH(area, &rdeconf->area_list, entry) {
                LIST_FOREACH(iface, &area->iface_list, entry) {
                        if ((iface->addr.s_addr & iface->mask.s_addr) ==
                            (prefix & iface->mask.s_addr) && (plen == -1 ||
                            iface->mask.s_addr == prefixlen2mask(plen)))
                                return (iface);
                }
        }
        return (NULL);
}

void
rde_asext_get(struct kroute *kr)
{
        struct asext_node       *an, *oan;
        struct vertex           *v;
        struct lsa              *lsa;
        u_int32_t                mask;

        if (rde_asext_lookup(kr->prefix.s_addr, kr->prefixlen)) {
                /* already announced as (stub) net LSA */
                log_debug("rde_asext_get: %s/%d is net LSA",
                    inet_ntoa(kr->prefix), kr->prefixlen);
                return;
        }

        an = asext_find(kr->prefix.s_addr, kr->prefixlen);
        if (an == NULL) {
                if ((an = calloc(1, sizeof(*an))) == NULL)
                        fatal("rde_asext_get");
                bcopy(kr, &an->r, sizeof(*kr));
                an->ls_id = kr->prefix.s_addr;
                RB_INSERT(asext_tree, &ast, an);
        } else {
                /* the bcopy does not change the lookup key so it is save */
                bcopy(kr, &an->r, sizeof(*kr));
        }

        /*
         * ls_id must be unique, for overlapping routes this may
         * not be true. In this case a unique ls_id needs to be found.
         * The algorithm will change the ls_id of the less specific
         * route. E.g. in the case of 10.0.0.0/16 and 10.0.0.0/24
         * 10.0.0.0/24 will get the 10.0.0.0 ls_id and 10.0.0.0/16
         * will change the ls_id to 10.0.255.255 and see if that is unique.
         */
        oan = an;
        mask = prefixlen2mask(oan->r.prefixlen);
        v = lsa_find(NULL, LSA_TYPE_EXTERNAL, oan->ls_id,
            rdeconf->rtr_id.s_addr);
        while (v && v->lsa->data.asext.mask != mask) {
                /* conflict needs to be resolved. change less specific lsa */
                if (ntohl(v->lsa->data.asext.mask) < ntohl(mask)) {
                        /* lsa to insert is more specific, fix other lsa */
                        mask = v->lsa->data.asext.mask;
                        oan = asext_find(v->lsa->hdr.ls_id & mask,
                           mask2prefixlen(mask));
                        if (oan == NULL)
                                fatalx("as-ext LSA DB corrupted");
                }
                /* oan is less specific and needs new ls_id */
                if (oan->ls_id == oan->r.prefix.s_addr)
                        oan->ls_id |= ~mask;
                else {
                        u_int32_t       tmp = ntohl(oan->ls_id);
                        oan->ls_id = htonl(tmp - 1);
                        if (oan->ls_id == oan->r.prefix.s_addr) {
                                log_warnx("prefix %s/%d can not be "
                                    "redistributed, no unique ls_id found.",
                                    inet_ntoa(kr->prefix), kr->prefixlen);
                                RB_REMOVE(asext_tree, &ast, an);
                                free(an);
                                return;
                        }
                }
                mask = prefixlen2mask(oan->r.prefixlen);
                v = lsa_find(NULL, LSA_TYPE_EXTERNAL, oan->ls_id,
                    rdeconf->rtr_id.s_addr);
        }

        v = lsa_find(NULL, LSA_TYPE_EXTERNAL, an->ls_id,
            rdeconf->rtr_id.s_addr);
        lsa = orig_asext_lsa(kr, an->ls_id, DEFAULT_AGE);
        lsa_merge(nbrself, lsa, v);

        if (oan != an) {
                v = lsa_find(NULL, LSA_TYPE_EXTERNAL, oan->ls_id,
                    rdeconf->rtr_id.s_addr);
                lsa = orig_asext_lsa(&oan->r, oan->ls_id, DEFAULT_AGE);
                lsa_merge(nbrself, lsa, v);
        }
}

void
rde_asext_put(struct kroute *kr)
{
        struct asext_node       *an;
        struct vertex           *v;
        struct lsa              *lsa;

        /*
         * just try to remove the LSA. If the prefix is announced as
         * stub net LSA asext_find() will fail and nothing will happen.
         */
        an = asext_find(kr->prefix.s_addr, kr->prefixlen);
        if (an == NULL) {
                log_debug("rde_asext_put: NO SUCH LSA %s/%d",
                    inet_ntoa(kr->prefix), kr->prefixlen);
                return;
        }

        /* inherit metric and ext_tag from the current LSA,
         * some routers don't like to get withdraws that are
         * different from what they have in their table.
         */
        v = lsa_find(NULL, LSA_TYPE_EXTERNAL, an->ls_id,
            rdeconf->rtr_id.s_addr);
        if (v != NULL) {
                kr->metric = ntohl(v->lsa->data.asext.metric);
                kr->ext_tag = ntohl(v->lsa->data.asext.ext_tag);
        }

        /* remove by reflooding with MAX_AGE */
        lsa = orig_asext_lsa(kr, an->ls_id, MAX_AGE);
        lsa_merge(nbrself, lsa, v);

        RB_REMOVE(asext_tree, &ast, an);
        free(an);
}

void
rde_asext_free(void)
{
        struct asext_node       *an, *nan;

        for (an = RB_MIN(asext_tree, &ast); an != NULL; an = nan) {
                nan = RB_NEXT(asext_tree, &ast, an);
                RB_REMOVE(asext_tree, &ast, an);
                free(an);
        }
}

struct lsa *
orig_asext_lsa(struct kroute *kr, u_int32_t ls_id, u_int16_t age)
{
        struct lsa      *lsa;
        struct iface    *iface;
        u_int16_t        len;

        len = sizeof(struct lsa_hdr) + sizeof(struct lsa_asext);
        if ((lsa = calloc(1, len)) == NULL)
                fatal("orig_asext_lsa");

        log_debug("orig_asext_lsa: %s/%d age %d",
            inet_ntoa(kr->prefix), kr->prefixlen, age);

        /* LSA header */
        lsa->hdr.age = htons(age);
        lsa->hdr.opts = area_ospf_options(NULL);
        lsa->hdr.type = LSA_TYPE_EXTERNAL;
        lsa->hdr.adv_rtr = rdeconf->rtr_id.s_addr;
        /* update of seqnum is done by lsa_merge */
        lsa->hdr.seq_num = htonl(INIT_SEQ_NUM);
        lsa->hdr.len = htons(len);

        /* prefix and mask */
        lsa->hdr.ls_id = ls_id;
        lsa->data.asext.mask = prefixlen2mask(kr->prefixlen);

        /*
         * nexthop -- on connected routes we are the nexthop,
         * in other cases we may announce the true nexthop if the
         * nexthop is reachable via an OSPF enabled interface but only
         * broadcast & NBMA interfaces are considered in that case.
         * It does not make sense to announce the nexthop of a point-to-point
         * link since the traffic has to go through this box anyway.
         * Some implementations actually check that there are multiple
         * neighbors on the particular segment, we skip that check.
         */
        iface = rde_asext_lookup(kr->nexthop.s_addr, -1);
        if (kr->flags & F_CONNECTED)
                lsa->data.asext.fw_addr = 0;
        else if (iface && (iface->type == IF_TYPE_BROADCAST ||
            iface->type == IF_TYPE_NBMA))
                lsa->data.asext.fw_addr = kr->nexthop.s_addr;
        else
                lsa->data.asext.fw_addr = 0;

        lsa->data.asext.metric = htonl(kr->metric);
        lsa->data.asext.ext_tag = htonl(kr->ext_tag);

        lsa->hdr.ls_chksum = 0;
        lsa->hdr.ls_chksum = htons(iso_cksum(lsa, len, LS_CKSUM_OFFSET));

        return (lsa);
}

/*
 * summary LSA stuff
 */
void
rde_summary_update(struct rt_node *rte, struct area *area)
{
        struct rt_nexthop       *rn;
        struct rt_node          *nr;
        struct vertex           *v = NULL;
        struct lsa              *lsa;
        u_int8_t                 type = 0;

        /* first check if we actually need to announce this route */
        if (!(rte->d_type == DT_NET || rte->flags & OSPF_RTR_E))
                return;
        /* route is invalid, lsa_remove_invalid_sums() will do the cleanup */
        if (rte->cost >= LS_INFINITY)
                return;
        /* never create summaries for as-ext LSA */
        if (rte->p_type == PT_TYPE1_EXT || rte->p_type == PT_TYPE2_EXT)
                return;
        /* no need for summary LSA in the originating area */
        if (rte->area.s_addr == area->id.s_addr)
                return;
        /* no need to originate inter-area routes to the backbone */
        if (rte->p_type == PT_INTER_AREA && area->id.s_addr == INADDR_ANY)
                return;
        /* nexthop check, nexthop part of area -> no summary */
        TAILQ_FOREACH(rn, &rte->nexthop, entry) {
                if (rn->invalid)
                        continue;
                nr = rt_lookup(DT_NET, rn->nexthop.s_addr);
                if (nr && nr->area.s_addr == area->id.s_addr)
                        continue;
                break;
        }
        if (rn == NULL)
                /* all nexthops belong to this area or are invalid */
                return;

        /* TODO AS border router specific checks */
        /* TODO inter-area network route stuff */
        /* TODO intra-area stuff -- condense LSA ??? */

        if (rte->d_type == DT_NET) {
                type = LSA_TYPE_SUM_NETWORK;
        } else if (rte->d_type == DT_RTR) {
                if (area->stub)
                        /* do not redistribute type 4 LSA into stub areas */
                        return;
                type = LSA_TYPE_SUM_ROUTER;
        } else
                fatalx("rde_summary_update: unknown route type");

        /* update lsa but only if it was changed */
        v = lsa_find_area(area, type, rte->prefix.s_addr, rde_router_id());
        lsa = orig_sum_lsa(rte, area, type, rte->invalid);
        lsa_merge(rde_nbr_self(area), lsa, v);

        if (v == NULL)
                v = lsa_find_area(area, type, rte->prefix.s_addr,
                    rde_router_id());

        /* suppressed/deleted routes are not found in the second lsa_find */
        if (v)
                v->cost = rte->cost;
}

struct lsa *
orig_sum_lsa(struct rt_node *rte, struct area *area, u_int8_t type, int invalid)
{
        struct lsa      *lsa;
        u_int16_t        len;

        len = sizeof(struct lsa_hdr) + sizeof(struct lsa_sum);
        if ((lsa = calloc(1, len)) == NULL)
                fatal("orig_sum_lsa");

        /* LSA header */
        lsa->hdr.age = htons(invalid ? MAX_AGE : DEFAULT_AGE);
        lsa->hdr.opts = area_ospf_options(area);
        lsa->hdr.type = type;
        lsa->hdr.adv_rtr = rdeconf->rtr_id.s_addr;
        lsa->hdr.seq_num = htonl(INIT_SEQ_NUM);
        lsa->hdr.len = htons(len);

        /* prefix and mask */
        /*
         * TODO ls_id must be unique, for overlapping routes this may
         * not be true. In this case a hack needs to be done to
         * make the ls_id unique.
         */
        lsa->hdr.ls_id = rte->prefix.s_addr;
        if (type == LSA_TYPE_SUM_NETWORK)
                lsa->data.sum.mask = prefixlen2mask(rte->prefixlen);
        else
                lsa->data.sum.mask = 0; /* must be zero per RFC */

        lsa->data.sum.metric = htonl(rte->cost & LSA_METRIC_MASK);

        lsa->hdr.ls_chksum = 0;
        lsa->hdr.ls_chksum =
            htons(iso_cksum(lsa, len, LS_CKSUM_OFFSET));

        return (lsa);
}