/*      $OpenBSD: kroute.c,v 1.70 2025/01/02 06:35:57 anton Exp $ */

/*
 * 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/sysctl.h>
#include <sys/tree.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

#include "ospf6d.h"
#include "ospfe.h"
#include "log.h"

struct {
        u_int32_t               rtseq;
        pid_t                   pid;
        int                     fib_sync;
        int                     fib_serial;
        u_int8_t                fib_prio;
        int                     fd;
        struct event            ev;
        struct event            reload;
        u_int                   rdomain;
#define KR_RELOAD_IDLE 0
#define KR_RELOAD_FETCH        1
#define KR_RELOAD_HOLD 2
        int                     reload_state;
} kr_state;

struct kroute_node {
        RB_ENTRY(kroute_node)    entry;
        struct kroute_node      *next;
        struct kroute            r;
        int                      serial;
};

void    kr_redist_remove(struct kroute_node *, struct kroute_node *);
int     kr_redist_eval(struct kroute *, struct kroute *);
void    kr_redistribute(struct kroute_node *);
int     kroute_compare(struct kroute_node *, struct kroute_node *);
int     kr_change_fib(struct kroute_node *, struct kroute *, int, int);
int     kr_delete_fib(struct kroute_node *);

struct kroute_node      *kroute_find(const struct in6_addr *, u_int8_t,
                            u_int8_t);
struct kroute_node      *kroute_matchgw(struct kroute_node *,
                            struct in6_addr *, unsigned int);
int                      kroute_insert(struct kroute_node *);
int                      kroute_remove(struct kroute_node *);
void                     kroute_clear(void);

struct iface            *kif_update(u_short, int, struct if_data *,
                           struct sockaddr_dl *);
int                      kif_validate(u_short);

struct kroute_node      *kroute_match(struct in6_addr *);

int             protect_lo(void);
void            get_rtaddrs(int, struct sockaddr *, struct sockaddr **);
void            if_change(u_short, int, struct if_data *, struct sockaddr_dl *);
void            if_newaddr(u_short, struct sockaddr_in6 *,
                    struct sockaddr_in6 *, struct sockaddr_in6 *);
void            if_deladdr(u_short, struct sockaddr_in6 *,
                    struct sockaddr_in6 *, struct sockaddr_in6 *);
void            if_announce(void *);

int             send_rtmsg(int, int, struct kroute *);
int             dispatch_rtmsg(void);
int             fetchtable(void);
int             rtmsg_process(char *, size_t);
void            kr_fib_reload_timer(int, short, void *);
void            kr_fib_reload_arm_timer(int);

RB_HEAD(kroute_tree, kroute_node)       krt;
RB_PROTOTYPE(kroute_tree, kroute_node, entry, kroute_compare)
RB_GENERATE(kroute_tree, kroute_node, entry, kroute_compare)

int
kr_init(int fs, u_int rdomain, int redis_label_or_prefix, u_int8_t fib_prio)
{
        int             opt = 0, rcvbuf, default_rcvbuf;
        socklen_t       optlen;
        int             filter_prio = fib_prio;
        int             filter_flags = RTF_LLINFO | RTF_BROADCAST;

        kr_state.fib_sync = fs;
        kr_state.rdomain = rdomain;
        kr_state.fib_prio = fib_prio;

        if ((kr_state.fd = socket(AF_ROUTE,
            SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, AF_INET6)) == -1) {
                log_warn("kr_init: socket");
                return (-1);
        }

        /* not interested in my own messages */
        if (setsockopt(kr_state.fd, SOL_SOCKET, SO_USELOOPBACK,
            &opt, sizeof(opt)) == -1)
                log_warn("kr_init: setsockopt");        /* not fatal */

        if (redis_label_or_prefix) {
                filter_prio = 0;
                log_info("%s: priority filter disabled", __func__);
        } else
                log_debug("%s: priority filter enabled", __func__);

        if (setsockopt(kr_state.fd, AF_ROUTE, ROUTE_PRIOFILTER, &filter_prio,
            sizeof(filter_prio)) == -1) {
                log_warn("%s: setsockopt AF_ROUTE ROUTE_PRIOFILTER", __func__);
                /* not fatal */
        }

        if (setsockopt(kr_state.fd, AF_ROUTE, ROUTE_FLAGFILTER, &filter_flags,
            sizeof(filter_flags)) == -1) {
                log_warn("%s: setsockopt AF_ROUTE ROUTE_FLAGFILTER", __func__);
                /* not fatal */
        }

        /* grow receive buffer, don't wanna miss messages */
        optlen = sizeof(default_rcvbuf);
        if (getsockopt(kr_state.fd, SOL_SOCKET, SO_RCVBUF,
            &default_rcvbuf, &optlen) == -1)
                log_warn("kr_init getsockopt SOL_SOCKET SO_RCVBUF");
        else
                for (rcvbuf = MAX_RTSOCK_BUF;
                    rcvbuf > default_rcvbuf &&
                    setsockopt(kr_state.fd, SOL_SOCKET, SO_RCVBUF,
                    &rcvbuf, sizeof(rcvbuf)) == -1 && errno == ENOBUFS;
                    rcvbuf /= 2)
                        ;       /* nothing */

        kr_state.pid = getpid();
        kr_state.rtseq = 1;

        RB_INIT(&krt);

        if (fetchtable() == -1)
                return (-1);

        if (protect_lo() == -1)
                return (-1);

        event_set(&kr_state.ev, kr_state.fd, EV_READ | EV_PERSIST,
            kr_dispatch_msg, NULL);
        event_add(&kr_state.ev, NULL);

        kr_state.reload_state = KR_RELOAD_IDLE;
        evtimer_set(&kr_state.reload, kr_fib_reload_timer, NULL);

        return (0);
}

int
kr_change_fib(struct kroute_node *kr, struct kroute *kroute, int krcount,
    int action)
{
        int                      i;
        struct kroute_node      *kn, *nkn;

        if (action == RTM_ADD) {
                /*
                 * First remove all stale multipath routes.
                 * This step must be skipped when the action is RTM_CHANGE
                 * because it is already a single path route that will be
                 * changed.
                 */
                for (kn = kr; kn != NULL; kn = nkn) {
                        for (i = 0; i < krcount; i++) {
                                if (kn->r.scope == kroute[i].scope &&
                                    IN6_ARE_ADDR_EQUAL(&kn->r.nexthop,
                                    &kroute[i].nexthop))
                                        break;
                        }
                        nkn = kn->next;
                        if (i == krcount) {
                                /* stale route */
                                if (kr_delete_fib(kn) == -1)
                                        log_warnx("kr_delete_fib failed");
                                /*
                                 * if head element was removed we need to adjust
                                 * the head
                                 */
                                if (kr == kn)
                                        kr = nkn;
                        }
                }
        }

        /*
         * now add or change the route
         */
        for (i = 0; i < krcount; i++) {
                /* nexthop ::1 -> ignore silently */
                if (IN6_IS_ADDR_LOOPBACK(&kroute[i].nexthop))
                        continue;

                if (action == RTM_ADD && kr) {
                        for (kn = kr; kn != NULL; kn = kn->next) {
                                if (kn->r.scope == kroute[i].scope &&
                                    IN6_ARE_ADDR_EQUAL(&kn->r.nexthop,
                                    &kroute[i].nexthop))
                                        break;
                        }

                        if (kn != NULL)
                                /* nexthop already present, skip it */
                                continue;
                } else
                        /* modify first entry */
                        kn = kr;

                /* send update */
                if (send_rtmsg(kr_state.fd, action, &kroute[i]) == -1)
                        return (-1);

                /* create new entry unless we are changing the first entry */
                if (action == RTM_ADD)
                        if ((kn = calloc(1, sizeof(*kn))) == NULL)
                                fatal(NULL);

                kn->r.prefix = kroute[i].prefix;
                kn->r.prefixlen = kroute[i].prefixlen;
                kn->r.nexthop = kroute[i].nexthop;
                kn->r.scope = kroute[i].scope;
                kn->r.flags = kroute[i].flags | F_OSPFD_INSERTED;
                kn->r.priority = kr_state.fib_prio;
                kn->r.ext_tag = kroute[i].ext_tag;
                rtlabel_unref(kn->r.rtlabel);   /* for RTM_CHANGE */
                kn->r.rtlabel = kroute[i].rtlabel;

                if (action == RTM_ADD)
                        if (kroute_insert(kn) == -1) {
                                log_debug("kr_update_fib: cannot insert %s",
                                    log_in6addr(&kn->r.nexthop));
                                free(kn);
                        }
                action = RTM_ADD;
        }
        return  (0);
}

int
kr_change(struct kroute *kroute, int krcount)
{
        struct kroute_node      *kr;
        int                      action = RTM_ADD;

        kroute->rtlabel = rtlabel_tag2id(kroute->ext_tag);

        kr = kroute_find(&kroute->prefix, kroute->prefixlen, kr_state.fib_prio);
        if (kr != NULL && kr->next == NULL && krcount == 1) {
                /*
                 * single path OSPF route.
                 * The kernel does not allow to change a gateway route to a
                 * cloning route or contrary. In this case remove and add the
                 * route, otherwise change the existing one.
                 */
                if ((IN6_IS_ADDR_UNSPECIFIED(&kroute->nexthop) &&
                    !IN6_IS_ADDR_UNSPECIFIED(&kr->r.nexthop)) ||
                    (!IN6_IS_ADDR_UNSPECIFIED(&kroute->nexthop) &&
                    IN6_IS_ADDR_UNSPECIFIED(&kr->r.nexthop))) {
                        if (kr_delete_fib(kr) == 0)
                                kr = NULL;
                        else {
                                log_warn("kr_change: failed to remove route: "
                                    "%s/%d", log_in6addr(&kr->r.prefix),
                                    kr->r.prefixlen);
                                return (-1);
                        }
                } else
                        action = RTM_CHANGE;
        }

        return (kr_change_fib(kr, kroute, krcount, action));
}

int
kr_delete_fib(struct kroute_node *kr)
{
        if (kr->r.priority != kr_state.fib_prio)
                log_warn("kr_delete_fib: %s/%d has wrong priority %d",
                    log_in6addr(&kr->r.prefix), kr->r.prefixlen,
                    kr->r.priority);

        if (send_rtmsg(kr_state.fd, RTM_DELETE, &kr->r) == -1)
                return (-1);

        if (kroute_remove(kr) == -1)
                return (-1);

        return (0);
}

int
kr_delete(struct kroute *kroute)
{
        struct kroute_node      *kr, *nkr;

        if ((kr = kroute_find(&kroute->prefix, kroute->prefixlen,
            kr_state.fib_prio)) == NULL)
                return (0);

        while (kr != NULL) {
                nkr = kr->next;
                if (kr_delete_fib(kr) == -1)
                        return (-1);
                kr = nkr;
        }

        return (0);
}

void
kr_shutdown(void)
{
        kr_fib_decouple();
        kroute_clear();
}

void
kr_fib_couple(void)
{
        struct kroute_node      *kr;
        struct kroute_node      *kn;

        if (kr_state.fib_sync == 1)     /* already coupled */
                return;

        kr_state.fib_sync = 1;

        RB_FOREACH(kr, kroute_tree, &krt)
                if (kr->r.priority == kr_state.fib_prio)
                        for (kn = kr; kn != NULL; kn = kn->next)
                                send_rtmsg(kr_state.fd, RTM_ADD, &kn->r);

        log_info("kernel routing table coupled");
}

void
kr_fib_decouple(void)
{
        struct kroute_node      *kr;
        struct kroute_node      *kn;

        if (kr_state.fib_sync == 0)     /* already decoupled */
                return;

        RB_FOREACH(kr, kroute_tree, &krt)
                if (kr->r.priority == kr_state.fib_prio)
                        for (kn = kr; kn != NULL; kn = kn->next)
                                send_rtmsg(kr_state.fd, RTM_DELETE, &kn->r);

        kr_state.fib_sync = 0;

        log_info("kernel routing table decoupled");
}

void
kr_fib_reload_timer(int fd, short event, void *bula)
{
        if (kr_state.reload_state == KR_RELOAD_FETCH) {
                kr_fib_reload();
                kr_state.reload_state = KR_RELOAD_HOLD;
                kr_fib_reload_arm_timer(KR_RELOAD_HOLD_TIMER);
        } else {
                kr_state.reload_state = KR_RELOAD_IDLE;
        }
}

void
kr_fib_reload_arm_timer(int delay)
{
        struct timeval          tv;

        timerclear(&tv);
        tv.tv_sec = delay / 1000;
        tv.tv_usec = (delay % 1000) * 1000;

        if (evtimer_add(&kr_state.reload, &tv) == -1)
                fatal("add_reload_timer");
}

void
kr_fib_reload(void)
{
        struct kroute_node      *krn, *kr, *kn;

        log_info("reloading interface list and routing table");

        kr_state.fib_serial++;

        if (fetchifs(0) != 0 || fetchtable() != 0)
                return;

        for (kr = RB_MIN(kroute_tree, &krt); kr != NULL; kr = krn) {
                krn = RB_NEXT(kroute_tree, &krt, kr);

                do {
                        kn = kr->next;

                        if (kr->serial != kr_state.fib_serial) {

                                if (kr->r.priority == kr_state.fib_prio) {
                                        kr->serial = kr_state.fib_serial;
                                        if (send_rtmsg(kr_state.fd,
                                            RTM_ADD, &kr->r) != 0)
                                                break;
                                } else
                                        kroute_remove(kr);
                        }

                } while ((kr = kn) != NULL);
        }
}

void
kr_fib_update_prio(u_int8_t fib_prio)
{
        struct kroute_node      *kr;

        RB_FOREACH(kr, kroute_tree, &krt)
                if ((kr->r.flags & F_OSPFD_INSERTED))
                        kr->r.priority = fib_prio;

        log_info("fib priority changed from %hhu to %hhu", kr_state.fib_prio,
            fib_prio);

        kr_state.fib_prio = fib_prio;
}

void
kr_dispatch_msg(int fd, short event, void *bula)
{
        /* XXX this is stupid */
        dispatch_rtmsg();
}

void
kr_show_route(struct imsg *imsg)
{
        struct kroute_node      *kr;
        struct kroute_node      *kn;
        int                      flags;
        struct in6_addr          addr;

        switch (imsg->hdr.type) {
        case IMSG_CTL_KROUTE:
                if (imsg->hdr.len != IMSG_HEADER_SIZE + sizeof(flags)) {
                        log_warnx("kr_show_route: wrong imsg len");
                        return;
                }
                memcpy(&flags, imsg->data, sizeof(flags));
                RB_FOREACH(kr, kroute_tree, &krt)
                        if (!flags || kr->r.flags & flags) {
                                kn = kr;
                                do {
                                        main_imsg_compose_ospfe(IMSG_CTL_KROUTE,
                                            imsg->hdr.pid,
                                            &kn->r, sizeof(kn->r));
                                } while ((kn = kn->next) != NULL);
                        }
                break;
        case IMSG_CTL_KROUTE_ADDR:
                if (imsg->hdr.len != IMSG_HEADER_SIZE +
                    sizeof(struct in6_addr)) {
                        log_warnx("kr_show_route: wrong imsg len");
                        return;
                }
                memcpy(&addr, imsg->data, sizeof(addr));
                kr = kroute_match(&addr);
                if (kr != NULL)
                        main_imsg_compose_ospfe(IMSG_CTL_KROUTE, imsg->hdr.pid,
                            &kr->r, sizeof(kr->r));
                break;
        default:
                log_debug("kr_show_route: error handling imsg");
                break;
        }

        main_imsg_compose_ospfe(IMSG_CTL_END, imsg->hdr.pid, NULL, 0);
}

void
kr_redist_remove(struct kroute_node *kh, struct kroute_node *kn)
{
        struct kroute    *kr;

        /* was the route redistributed? */
        if ((kn->r.flags & F_REDISTRIBUTED) == 0)
                return;

        /* remove redistributed flag */
        kn->r.flags &= ~F_REDISTRIBUTED;
        kr = &kn->r;

        /* probably inform the RDE (check if no other path is redistributed) */
        for (kn = kh; kn; kn = kn->next)
                if (kn->r.flags & F_REDISTRIBUTED)
                        break;

        if (kn == NULL)
                main_imsg_compose_rde(IMSG_NETWORK_DEL, 0, kr,
                    sizeof(struct kroute));
}

int
kr_redist_eval(struct kroute *kr, struct kroute *new_kr)
{
        u_int32_t        metric = 0;

        /* Only non-ospfd routes are considered for redistribution. */
        if (!(kr->flags & F_KERNEL))
                goto dont_redistribute;

        /* Dynamic routes are not redistributable. */
        if (kr->flags & F_DYNAMIC)
                goto dont_redistribute;

        /* interface is not up and running so don't announce */
        if (kr->flags & F_DOWN)
                goto dont_redistribute;

        /*
         * We consider loopback, multicast, link- and site-local,
         * IPv4 mapped and IPv4 compatible addresses as not redistributable.
         */
        if (IN6_IS_ADDR_LOOPBACK(&kr->prefix) ||
            IN6_IS_ADDR_MULTICAST(&kr->prefix) ||
            IN6_IS_ADDR_LINKLOCAL(&kr->prefix) ||
            IN6_IS_ADDR_SITELOCAL(&kr->prefix) ||
            IN6_IS_ADDR_V4MAPPED(&kr->prefix) ||
            IN6_IS_ADDR_V4COMPAT(&kr->prefix))
                goto dont_redistribute;
        /*
         * Consider networks with nexthop loopback as not redistributable
         * unless it is a reject or blackhole route.
         */
        if (IN6_IS_ADDR_LOOPBACK(&kr->nexthop) &&
            !(kr->flags & (F_BLACKHOLE|F_REJECT)))
                goto dont_redistribute;

        /* Should we redistribute this route? */
        if (!ospf_redistribute(kr, &metric))
                goto dont_redistribute;

        /* prefix should be redistributed */
        kr->flags |= F_REDISTRIBUTED;
        /*
         * only one of all multipath routes can be redistributed so
         * redistribute the best one.
         */
        if (new_kr->metric > metric) {
                *new_kr = *kr;
                new_kr->metric = metric;
        }

        return (1);

dont_redistribute:
        /* was the route redistributed? */
        if ((kr->flags & F_REDISTRIBUTED) == 0)
                return (0);

        kr->flags &= ~F_REDISTRIBUTED;
        return (1);
}

void
kr_redistribute(struct kroute_node *kh)
{
        struct kroute_node      *kn;
        struct kroute            kr;
        int                      redistribute = 0;

        /* only the highest prio route can be redistributed */
        if (kroute_find(&kh->r.prefix, kh->r.prefixlen, RTP_ANY) != kh)
                return;

        bzero(&kr, sizeof(kr));
        kr.metric = UINT_MAX;
        for (kn = kh; kn; kn = kn->next)
                if (kr_redist_eval(&kn->r, &kr))
                        redistribute = 1;

        if (!redistribute)
                return;

        if (kr.flags & F_REDISTRIBUTED) {
                main_imsg_compose_rde(IMSG_NETWORK_ADD, 0, &kr,
                    sizeof(struct kroute));
        } else {
                kr = kh->r;
                main_imsg_compose_rde(IMSG_NETWORK_DEL, 0, &kr,
                    sizeof(struct kroute));
        }
}

void
kr_reload(int redis_label_or_prefix)
{
        struct kroute_node      *kr, *kn;
        u_int32_t                dummy;
        int                      r;
        int                      filter_prio = kr_state.fib_prio;

        /* update the priority filter */
        if (redis_label_or_prefix) {
                filter_prio = 0;
                log_info("%s: priority filter disabled", __func__);
        } else
                log_debug("%s: priority filter enabled", __func__);

        if (setsockopt(kr_state.fd, AF_ROUTE, ROUTE_PRIOFILTER, &filter_prio,
            sizeof(filter_prio)) == -1) {
                log_warn("%s: setsockopt AF_ROUTE ROUTE_PRIOFILTER", __func__);
                /* not fatal */
        }

        RB_FOREACH(kr, kroute_tree, &krt) {
                for (kn = kr; kn; kn = kn->next) {
                        r = ospf_redistribute(&kn->r, &dummy);
                        /*
                         * if it is redistributed, redistribute again metric
                         * may have changed.
                         */
                        if ((kn->r.flags & F_REDISTRIBUTED && !r) || r)
                                break;
                }
                if (kn) {
                        /*
                         * kr_redistribute copes with removes and RDE with
                         * duplicates
                         */
                        kr_redistribute(kr);
                }
        }
}

/* rb-tree compare */
int
kroute_compare(struct kroute_node *a, struct kroute_node *b)
{
        int     i;

        /* XXX maybe switch a & b */
        i = memcmp(&a->r.prefix, &b->r.prefix, sizeof(a->r.prefix));
        if (i)
                return (i);
        if (a->r.prefixlen < b->r.prefixlen)
                return (-1);
        if (a->r.prefixlen > b->r.prefixlen)
                return (1);

        /* if the priority is RTP_ANY finish on the first address hit */
        if (a->r.priority == RTP_ANY || b->r.priority == RTP_ANY)
                return (0);
        if (a->r.priority < b->r.priority)
                return (-1);
        if (a->r.priority > b->r.priority)
                return (1);
        return (0);
}

/* tree management */
struct kroute_node *
kroute_find(const struct in6_addr *prefix, u_int8_t prefixlen, u_int8_t prio)
{
        struct kroute_node      s;
        struct kroute_node      *kn, *tmp;

        s.r.prefix = *prefix;
        s.r.prefixlen = prefixlen;
        s.r.priority = prio;

        kn = RB_FIND(kroute_tree, &krt, &s);
        if (kn && prio == RTP_ANY) {
                tmp = RB_PREV(kroute_tree, &krt, kn);
                while (tmp) {
                        if (kroute_compare(&s, tmp) == 0)
                                kn = tmp;
                        else
                                break;
                        tmp = RB_PREV(kroute_tree, &krt, kn);
                }
        }
        return (kn);
}

struct kroute_node *
kroute_matchgw(struct kroute_node *kr, struct in6_addr *nh, unsigned int scope)
{
        while (kr) {
                if (scope == kr->r.scope &&
                    IN6_ARE_ADDR_EQUAL(&kr->r.nexthop, nh))
                        return (kr);
                kr = kr->next;
        }

        return (NULL);
}

int
kroute_insert(struct kroute_node *kr)
{
        struct kroute_node      *krm, *krh;

        kr->serial = kr_state.fib_serial;

        if ((krh = RB_INSERT(kroute_tree, &krt, kr)) != NULL) {
                /*
                 * Multipath route, add at end of list.
                 */
                krm = krh;
                while (krm->next != NULL)
                        krm = krm->next;
                krm->next = kr;
                kr->next = NULL; /* to be sure */
        } else
                krh = kr;

        if (!(kr->r.flags & F_KERNEL)) {
                /* don't validate or redistribute ospf route */
                kr->r.flags &= ~F_DOWN;
                return (0);
        }

        if (kif_validate(kr->r.ifindex))
                kr->r.flags &= ~F_DOWN;
        else
                kr->r.flags |= F_DOWN;

        kr_redistribute(krh);
        return (0);
}

int
kroute_remove(struct kroute_node *kr)
{
        struct kroute_node      *krm;

        if ((krm = RB_FIND(kroute_tree, &krt, kr)) == NULL) {
                log_warnx("kroute_remove failed to find %s/%u",
                    log_in6addr(&kr->r.prefix), kr->r.prefixlen);
                return (-1);
        }

        if (krm == kr) {
                /* head element */
                if (RB_REMOVE(kroute_tree, &krt, kr) == NULL) {
                        log_warnx("kroute_remove failed for %s/%u",
                            log_in6addr(&kr->r.prefix), kr->r.prefixlen);
                        return (-1);
                }
                if (kr->next != NULL) {
                        if (RB_INSERT(kroute_tree, &krt, kr->next) != NULL) {
                                log_warnx("kroute_remove failed to add %s/%u",
                                    log_in6addr(&kr->r.prefix),
                                    kr->r.prefixlen);
                                return (-1);
                        }
                }
        } else {
                /* somewhere in the list */
                while (krm->next != kr && krm->next != NULL)
                        krm = krm->next;
                if (krm->next == NULL) {
                        log_warnx("kroute_remove multipath list corrupted "
                            "for %s/%u", log_in6addr(&kr->r.prefix),
                            kr->r.prefixlen);
                        return (-1);
                }
                krm->next = kr->next;
        }

        kr_redist_remove(krm, kr);
        rtlabel_unref(kr->r.rtlabel);

        free(kr);
        return (0);
}

void
kroute_clear(void)
{
        struct kroute_node      *kr;

        while ((kr = RB_MIN(kroute_tree, &krt)) != NULL)
                kroute_remove(kr);
}

struct iface *
kif_update(u_short ifindex, int flags, struct if_data *ifd,
    struct sockaddr_dl *sdl)
{
        struct iface    *iface;
        char             ifname[IF_NAMESIZE];

        if ((iface = if_find(ifindex)) == NULL) {
                bzero(ifname, sizeof(ifname));
                if (sdl && sdl->sdl_family == AF_LINK) {
                        if (sdl->sdl_nlen >= sizeof(ifname))
                                memcpy(ifname, sdl->sdl_data,
                                    sizeof(ifname) - 1);
                        else if (sdl->sdl_nlen > 0)
                                memcpy(ifname, sdl->sdl_data, sdl->sdl_nlen);
                        else
                                return (NULL);
                } else
                        return (NULL);
                if ((iface = if_new(ifindex, ifname)) == NULL)
                        return (NULL);
        }

        if_update(iface, ifd->ifi_mtu, flags, ifd->ifi_type,
            ifd->ifi_link_state, ifd->ifi_baudrate, ifd->ifi_rdomain);

        return (iface);
}

int
kif_validate(u_short ifindex)
{
        struct iface    *iface;

        if ((iface = if_find(ifindex)) == NULL) {
                log_warnx("interface with index %u not found", ifindex);
                return (-1);
        }

        return ((iface->flags & IFF_UP) && LINK_STATE_IS_UP(iface->linkstate));
}

struct kroute_node *
kroute_match(struct in6_addr *key)
{
        int                      i;
        struct kroute_node      *kr;
        struct in6_addr          ina;

        /* we will never match the default route */
        for (i = 128; i > 0; i--) {
                inet6applymask(&ina, key, i);
                if ((kr = kroute_find(&ina, i, RTP_ANY)) != NULL)
                        return (kr);
        }

        /* if we don't have a match yet, try to find a default route */
        if ((kr = kroute_find(&in6addr_any, 0, RTP_ANY)) != NULL)
                        return (kr);

        return (NULL);
}

/* misc */
int
protect_lo(void)
{
        struct kroute_node      *kr;

        /* special protection for loopback */
        if ((kr = calloc(1, sizeof(struct kroute_node))) == NULL) {
                log_warn("protect_lo");
                return (-1);
        }
        memcpy(&kr->r.prefix, &in6addr_loopback, sizeof(kr->r.prefix));
        kr->r.prefixlen = 128;
        kr->r.flags = F_KERNEL|F_CONNECTED;

        if (RB_INSERT(kroute_tree, &krt, kr) != NULL)
                free(kr);       /* kernel route already there, no problem */

        return (0);
}

#define ROUNDUP(a) \
        ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))

void
get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
{
        int     i;

        for (i = 0; i < RTAX_MAX; i++) {
                if (addrs & (1 << i)) {
                        rti_info[i] = sa;
                        sa = (struct sockaddr *)((char *)(sa) +
                            ROUNDUP(sa->sa_len));
                } else
                        rti_info[i] = NULL;
        }
}

void
if_change(u_short ifindex, int flags, struct if_data *ifd,
    struct sockaddr_dl *sdl)
{
        struct kroute_node      *kr, *tkr;
        struct iface            *iface;
        u_int8_t                 wasvalid, isvalid;

        wasvalid = kif_validate(ifindex);

        if ((iface = kif_update(ifindex, flags, ifd, sdl)) == NULL) {
                log_warn("if_change: kif_update(%u)", ifindex);
                return;
        }

        /* inform engine and rde about state change */
        main_imsg_compose_rde(IMSG_IFINFO, 0, iface, sizeof(struct iface));
        main_imsg_compose_ospfe(IMSG_IFINFO, 0, iface, sizeof(struct iface));

        isvalid = (iface->flags & IFF_UP) &&
            LINK_STATE_IS_UP(iface->linkstate);

        if (wasvalid == isvalid)
                return;         /* nothing changed wrt validity */

        /* update redistribute list */
        RB_FOREACH(kr, kroute_tree, &krt) {
                for (tkr = kr; tkr != NULL; tkr = tkr->next) {
                        if (tkr->r.ifindex == ifindex) {
                                if (isvalid)
                                        tkr->r.flags &= ~F_DOWN;
                                else
                                        tkr->r.flags |= F_DOWN;

                        }
                }
                kr_redistribute(kr);
        }
}

void
if_newaddr(u_short ifindex, struct sockaddr_in6 *ifa, struct sockaddr_in6 *mask,
    struct sockaddr_in6 *brd)
{
        struct iface            *iface;
        struct iface_addr       *ia;
        struct ifaddrchange      ifc;

        if (ifa == NULL || ifa->sin6_family != AF_INET6)
                return;
        if ((iface = if_find(ifindex)) == NULL) {
                log_warnx("if_newaddr: corresponding if %d not found", ifindex);
                return;
        }

        /* We only care about link-local and global-scope. */
        if (IN6_IS_ADDR_UNSPECIFIED(&ifa->sin6_addr) ||
            IN6_IS_ADDR_LOOPBACK(&ifa->sin6_addr) ||
            IN6_IS_ADDR_MULTICAST(&ifa->sin6_addr) ||
            IN6_IS_ADDR_SITELOCAL(&ifa->sin6_addr) ||
            IN6_IS_ADDR_V4MAPPED(&ifa->sin6_addr) ||
            IN6_IS_ADDR_V4COMPAT(&ifa->sin6_addr))
                return;

        clearscope(&ifa->sin6_addr);

        if (IN6_IS_ADDR_LINKLOCAL(&ifa->sin6_addr) ||
            iface->flags & IFF_LOOPBACK)
                iface->addr = ifa->sin6_addr;

        if ((ia = calloc(1, sizeof(struct iface_addr))) == NULL)
                fatal("if_newaddr");

        ia->addr = ifa->sin6_addr;

        if (mask)
                ia->prefixlen = mask2prefixlen(mask);
        else
                ia->prefixlen = 0;
        if (brd && brd->sin6_family == AF_INET6)
                ia->dstbrd = brd->sin6_addr;
        else
                bzero(&ia->dstbrd, sizeof(ia->dstbrd));

        switch (iface->type) {
        case IF_TYPE_BROADCAST:
        case IF_TYPE_NBMA:
                log_debug("if_newaddr: ifindex %u, addr %s/%d",
                    ifindex, log_in6addr(&ia->addr), ia->prefixlen);
                break;
        case IF_TYPE_VIRTUALLINK:       /* FIXME */
                break;
        case IF_TYPE_POINTOPOINT:
        case IF_TYPE_POINTOMULTIPOINT:
                log_debug("if_newaddr: ifindex %u, addr %s/%d, "
                    "dest %s", ifindex, log_in6addr(&ia->addr),
                    ia->prefixlen, log_in6addr(&ia->dstbrd));
                break;
        default:
                fatalx("if_newaddr: unknown interface type");
        }

        TAILQ_INSERT_TAIL(&iface->ifa_list, ia, entry);
        /* inform engine and rde if interface is used */
        if (iface->cflags & F_IFACE_CONFIGURED) {
                ifc.addr = ia->addr;
                ifc.dstbrd = ia->dstbrd;
                ifc.prefixlen = ia->prefixlen;
                ifc.ifindex = ifindex;
                main_imsg_compose_ospfe(IMSG_IFADDRNEW, 0, &ifc, sizeof(ifc));
                main_imsg_compose_rde(IMSG_IFADDRNEW, 0, &ifc, sizeof(ifc));
        }
}

void
if_deladdr(u_short ifindex, struct sockaddr_in6 *ifa, struct sockaddr_in6 *mask,
    struct sockaddr_in6 *brd)
{
        struct iface            *iface;
        struct iface_addr       *ia, *nia;
        struct ifaddrchange      ifc;

        if (ifa == NULL || ifa->sin6_family != AF_INET6)
                return;
        if ((iface = if_find(ifindex)) == NULL) {
                log_warnx("if_deladdr: corresponding if %d not found", ifindex);
                return;
        }

        /* We only care about link-local and global-scope. */
        if (IN6_IS_ADDR_UNSPECIFIED(&ifa->sin6_addr) ||
            IN6_IS_ADDR_LOOPBACK(&ifa->sin6_addr) ||
            IN6_IS_ADDR_MULTICAST(&ifa->sin6_addr) ||
            IN6_IS_ADDR_SITELOCAL(&ifa->sin6_addr) ||
            IN6_IS_ADDR_V4MAPPED(&ifa->sin6_addr) ||
            IN6_IS_ADDR_V4COMPAT(&ifa->sin6_addr))
                return;

        clearscope(&ifa->sin6_addr);

        for (ia = TAILQ_FIRST(&iface->ifa_list); ia != NULL; ia = nia) {
                nia = TAILQ_NEXT(ia, entry);

                if (IN6_ARE_ADDR_EQUAL(&ia->addr, &ifa->sin6_addr)) {
                        log_debug("if_deladdr: ifindex %u, addr %s/%d",
                            ifindex, log_in6addr(&ia->addr), ia->prefixlen);
                        TAILQ_REMOVE(&iface->ifa_list, ia, entry);
                        /* inform engine and rde if interface is used */
                        if (iface->cflags & F_IFACE_CONFIGURED) {
                                ifc.addr = ia->addr;
                                ifc.dstbrd = ia->dstbrd;
                                ifc.prefixlen = ia->prefixlen;
                                ifc.ifindex = ifindex;
                                main_imsg_compose_ospfe(IMSG_IFADDRDEL, 0, &ifc,
                                    sizeof(ifc));
                                main_imsg_compose_rde(IMSG_IFADDRDEL, 0, &ifc,
                                    sizeof(ifc));
                        }
                        free(ia);
                        return;
                }
        }
}

void
if_announce(void *msg)
{
        struct if_announcemsghdr        *ifan;
        struct iface                    *iface;

        ifan = msg;

        switch (ifan->ifan_what) {
        case IFAN_ARRIVAL:
                if ((iface = if_new(ifan->ifan_index, ifan->ifan_name)) == NULL)
                        fatal("if_announce failed");
                break;
        case IFAN_DEPARTURE:
                iface = if_find(ifan->ifan_index);
                if (iface != NULL)
                        if_del(iface);
                break;
        }
}

/* rtsock */
int
send_rtmsg(int fd, int action, struct kroute *kroute)
{
        struct iovec            iov[5];
        struct rt_msghdr        hdr;
        struct pad {
                struct sockaddr_in6     addr;
                char                    pad[sizeof(long)]; /* thank you IPv6 */
        } prefix, nexthop, mask;
        struct {
                struct sockaddr_dl      addr;
                char                    pad[sizeof(long)];
        } ifp;
        struct sockaddr_rtlabel sa_rl;
        int                     iovcnt = 0;
        const char              *label;

        if (kr_state.fib_sync == 0)
                return (0);

        /* initialize header */
        bzero(&hdr, sizeof(hdr));
        hdr.rtm_version = RTM_VERSION;
        hdr.rtm_type = action;
        hdr.rtm_priority = kr_state.fib_prio;
        hdr.rtm_tableid = kr_state.rdomain;     /* rtableid */
        if (action == RTM_CHANGE)
                hdr.rtm_fmask = RTF_REJECT|RTF_BLACKHOLE;
        else
                hdr.rtm_flags = RTF_MPATH;
        hdr.rtm_seq = kr_state.rtseq++; /* overflow doesn't matter */
        hdr.rtm_hdrlen = sizeof(hdr);
        hdr.rtm_msglen = sizeof(hdr);
        /* adjust iovec */
        iov[iovcnt].iov_base = &hdr;
        iov[iovcnt++].iov_len = sizeof(hdr);

        bzero(&prefix, sizeof(prefix));
        prefix.addr.sin6_len = sizeof(struct sockaddr_in6);
        prefix.addr.sin6_family = AF_INET6;
        prefix.addr.sin6_addr = kroute->prefix;
        /* adjust header */
        hdr.rtm_addrs |= RTA_DST;
        hdr.rtm_msglen += ROUNDUP(sizeof(struct sockaddr_in6));
        /* adjust iovec */
        iov[iovcnt].iov_base = &prefix;
        iov[iovcnt++].iov_len = ROUNDUP(sizeof(struct sockaddr_in6));

        if (!IN6_IS_ADDR_UNSPECIFIED(&kroute->nexthop)) {
                bzero(&nexthop, sizeof(nexthop));
                nexthop.addr.sin6_len = sizeof(struct sockaddr_in6);
                nexthop.addr.sin6_family = AF_INET6;
                nexthop.addr.sin6_addr = kroute->nexthop;
                nexthop.addr.sin6_scope_id = kroute->scope;
                /*
                 * XXX we should set the sin6_scope_id but the kernel
                 * XXX does not expect it that way. It must be fiddled
                 * XXX into the sin6_addr. Welcome to the typical
                 * XXX IPv6 insanity and all without wine bottles.
                 */
                embedscope(&nexthop.addr);

                /* adjust header */
                hdr.rtm_flags |= RTF_GATEWAY;
                hdr.rtm_addrs |= RTA_GATEWAY;
                hdr.rtm_msglen += ROUNDUP(sizeof(struct sockaddr_in6));
                /* adjust iovec */
                iov[iovcnt].iov_base = &nexthop;
                iov[iovcnt++].iov_len = ROUNDUP(sizeof(struct sockaddr_in6));
        } else if (kroute->ifindex) {
                /*
                 * We don't have an interface address in that network,
                 * so we install a cloning route.  The kernel will then
                 * do neighbor discovery.
                 */
                bzero(&ifp, sizeof(ifp));
                ifp.addr.sdl_len = sizeof(struct sockaddr_dl);
                ifp.addr.sdl_family = AF_LINK;

                ifp.addr.sdl_index  = kroute->ifindex;
                /* adjust header */
                hdr.rtm_flags |= RTF_CLONING;
                hdr.rtm_addrs |= RTA_GATEWAY;
                hdr.rtm_msglen += ROUNDUP(sizeof(struct sockaddr_dl));
                /* adjust iovec */
                iov[iovcnt].iov_base = &ifp;
                iov[iovcnt++].iov_len = ROUNDUP(sizeof(struct sockaddr_dl));
        }

        bzero(&mask, sizeof(mask));
        mask.addr.sin6_len = sizeof(struct sockaddr_in6);
        mask.addr.sin6_family = AF_INET6;
        mask.addr.sin6_addr = *prefixlen2mask(kroute->prefixlen);
        /* adjust header */
        if (kroute->prefixlen == 128)
                hdr.rtm_flags |= RTF_HOST;
        hdr.rtm_addrs |= RTA_NETMASK;
        hdr.rtm_msglen += ROUNDUP(sizeof(struct sockaddr_in6));
        /* adjust iovec */
        iov[iovcnt].iov_base = &mask;
        iov[iovcnt++].iov_len = ROUNDUP(sizeof(struct sockaddr_in6));

        if (kroute->rtlabel != 0) {
                sa_rl.sr_len = sizeof(sa_rl);
                sa_rl.sr_family = AF_UNSPEC;
                label = rtlabel_id2name(kroute->rtlabel);
                if (strlcpy(sa_rl.sr_label, label,
                    sizeof(sa_rl.sr_label)) >= sizeof(sa_rl.sr_label)) {
                        log_warnx("send_rtmsg: invalid rtlabel");
                        return (-1);
                }
                /* adjust header */
                hdr.rtm_addrs |= RTA_LABEL;
                hdr.rtm_msglen += sizeof(sa_rl);
                /* adjust iovec */
                iov[iovcnt].iov_base = &sa_rl;
                iov[iovcnt++].iov_len = sizeof(sa_rl);
        }

retry:
        if (writev(fd, iov, iovcnt) == -1) {
                if (errno == ESRCH) {
                        if (hdr.rtm_type == RTM_CHANGE) {
                                hdr.rtm_type = RTM_ADD;
                                goto retry;
                        } else if (hdr.rtm_type == RTM_DELETE) {
                                log_info("route %s/%u vanished before delete",
                                    log_sockaddr(&prefix), kroute->prefixlen);
                                return (0);
                        }
                }
                log_warn("send_rtmsg: action %u, prefix %s/%u", hdr.rtm_type,
                    log_sockaddr(&prefix), kroute->prefixlen);
                return (0);
        }

        return (0);
}

int
fetchtable(void)
{
        size_t                   len;
        int                      mib[7];
        char                    *buf;
        int                      rv;

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = AF_INET6;
        mib[4] = NET_RT_DUMP;
        mib[5] = 0;
        mib[6] = kr_state.rdomain;      /* rtableid */

        if (sysctl(mib, 7, NULL, &len, NULL, 0) == -1) {
                log_warn("sysctl");
                return (-1);
        }
        if ((buf = malloc(len)) == NULL) {
                log_warn("fetchtable");
                return (-1);
        }
        if (sysctl(mib, 7, buf, &len, NULL, 0) == -1) {
                log_warn("sysctl");
                free(buf);
                return (-1);
        }

        rv = rtmsg_process(buf, len);
        free(buf);

        return (rv);
}

int
fetchifs(u_short ifindex)
{
        size_t                   len;
        int                      mib[6];
        char                    *buf;
        int                      rv;

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = AF_INET6;
        mib[4] = NET_RT_IFLIST;
        mib[5] = ifindex;

        if (sysctl(mib, 6, NULL, &len, NULL, 0) == -1) {
                log_warn("sysctl");
                return (-1);
        }
        if ((buf = malloc(len)) == NULL) {
                log_warn("fetchifs");
                return (-1);
        }
        if (sysctl(mib, 6, buf, &len, NULL, 0) == -1) {
                log_warn("sysctl");
                free(buf);
                return (-1);
        }

        rv = rtmsg_process(buf, len);
        free(buf);

        return (rv);
}

int
dispatch_rtmsg(void)
{
        char                     buf[RT_BUF_SIZE];
        ssize_t                  n;

        if ((n = read(kr_state.fd, &buf, sizeof(buf))) == -1) {
                if (errno == EAGAIN || errno == EINTR)
                        return (0);
                log_warn("dispatch_rtmsg: read error");
                return (-1);
        }

        if (n == 0) {
                log_warnx("routing socket closed");
                return (-1);
        }

        return (rtmsg_process(buf, n));
}

int
rtmsg_process(char *buf, size_t len)
{
        struct rt_msghdr        *rtm;
        struct if_msghdr         ifm;
        struct ifa_msghdr       *ifam;
        struct sockaddr         *sa, *rti_info[RTAX_MAX];
        struct sockaddr_in6     *sa_in6;
        struct sockaddr_rtlabel *label;
        struct kroute_node      *kr, *okr;
        struct in6_addr          prefix, nexthop;
        u_int8_t                 prefixlen, prio;
        int                      flags, mpath;
        unsigned int             scope;
        u_short                  ifindex = 0;
        int                      rv, delay;
        size_t                   offset;
        char                    *next;

        for (offset = 0; offset < len; offset += rtm->rtm_msglen) {
                next = buf + offset;
                rtm = (struct rt_msghdr *)next;
                if (len < offset + sizeof(u_short) ||
                    len < offset + rtm->rtm_msglen)
                        fatalx("rtmsg_process: partial rtm in buffer");
                if (rtm->rtm_version != RTM_VERSION)
                        continue;

                bzero(&prefix, sizeof(prefix));
                bzero(&nexthop, sizeof(nexthop));
                scope = 0;
                prefixlen = 0;
                flags = F_KERNEL;
                mpath = 0;
                prio = 0;

                sa = (struct sockaddr *)(next + rtm->rtm_hdrlen);
                get_rtaddrs(rtm->rtm_addrs, sa, rti_info);

                switch (rtm->rtm_type) {
                case RTM_ADD:
                case RTM_GET:
                case RTM_CHANGE:
                case RTM_DELETE:
                        if (rtm->rtm_errno)             /* failed attempts... */
                                continue;

                        if (rtm->rtm_tableid != kr_state.rdomain)
                                continue;

                        if (rtm->rtm_type == RTM_GET &&
                            rtm->rtm_pid != kr_state.pid) /* caused by us */
                                continue;

                        if ((sa = rti_info[RTAX_DST]) == NULL)
                                continue;

                        /* Skip ARP/ND cache and broadcast routes. */
                        if (rtm->rtm_flags & (RTF_LLINFO|RTF_BROADCAST))
                                continue;

                        if (rtm->rtm_flags & RTF_MPATH)
                                mpath = 1;
                        prio = rtm->rtm_priority;
                        flags = (prio == kr_state.fib_prio) ?
                            F_OSPFD_INSERTED : F_KERNEL;

                        switch (sa->sa_family) {
                        case AF_INET6:
                                prefix =
                                    ((struct sockaddr_in6 *)sa)->sin6_addr;
                                sa_in6 = (struct sockaddr_in6 *)
                                    rti_info[RTAX_NETMASK];
                                if (sa_in6 != NULL) {
                                        if (sa_in6->sin6_len != 0)
                                                prefixlen = mask2prefixlen(
                                                    sa_in6);
                                } else if (rtm->rtm_flags & RTF_HOST)
                                        prefixlen = 128;
                                else
                                        fatalx("classful IPv6 address?!!");
                                if (rtm->rtm_flags & RTF_STATIC)
                                        flags |= F_STATIC;
                                if (rtm->rtm_flags & RTF_BLACKHOLE)
                                        flags |= F_BLACKHOLE;
                                if (rtm->rtm_flags & RTF_REJECT)
                                        flags |= F_REJECT;
                                if (rtm->rtm_flags & RTF_DYNAMIC)
                                        flags |= F_DYNAMIC;
                                break;
                        default:
                                continue;
                        }

                        ifindex = rtm->rtm_index;
                        if ((sa = rti_info[RTAX_GATEWAY]) != NULL) {
                                switch (sa->sa_family) {
                                case AF_INET6:
                                        if (rtm->rtm_flags & RTF_CONNECTED)
                                                flags |= F_CONNECTED;

                                        sa_in6 = (struct sockaddr_in6 *)sa;
                                        /*
                                         * XXX The kernel provides the scope
                                         * XXX via the kame hack instead of
                                         * XXX the scope_id field.
                                         */
                                        recoverscope(sa_in6);
                                        nexthop = sa_in6->sin6_addr;
                                        scope = sa_in6->sin6_scope_id;
                                        break;
                                case AF_LINK:
                                        flags |= F_CONNECTED;
                                        break;
                                }
                        }
                }

                switch (rtm->rtm_type) {
                case RTM_ADD:
                case RTM_GET:
                case RTM_CHANGE:
                        if (IN6_IS_ADDR_UNSPECIFIED(&nexthop) &&
                            !(flags & F_CONNECTED)) {
                                log_warnx("rtmsg_process no nexthop for %s/%u",
                                    log_in6addr(&prefix), prefixlen);
                                continue;
                        }

                        if ((okr = kroute_find(&prefix, prefixlen, prio))
                            != NULL) {
                                kr = okr;
                                if ((mpath || prio == kr_state.fib_prio) &&
                                    (kr = kroute_matchgw(okr, &nexthop, scope)) ==
                                    NULL) {
                                        log_warnx("rtmsg_process: mpath route"
                                            " not found");
                                        /* add routes we missed out earlier */
                                        goto add;
                                }

                                if (kr->r.flags & F_REDISTRIBUTED)
                                        flags |= F_REDISTRIBUTED;
                                kr->r.nexthop = nexthop;
                                kr->r.scope = scope;
                                kr->r.flags = flags;
                                kr->r.ifindex = ifindex;

                                rtlabel_unref(kr->r.rtlabel);
                                kr->r.rtlabel = 0;
                                kr->r.ext_tag = 0;
                                if ((label = (struct sockaddr_rtlabel *)
                                    rti_info[RTAX_LABEL]) != NULL) {
                                        kr->r.rtlabel =
                                            rtlabel_name2id(label->sr_label);
                                        kr->r.ext_tag =
                                            rtlabel_id2tag(kr->r.rtlabel);
                                }

                                if (kif_validate(kr->r.ifindex))
                                        kr->r.flags &= ~F_DOWN;
                                else
                                        kr->r.flags |= F_DOWN;

                                /* just readd, the RDE will care */
                                kr->serial = kr_state.fib_serial;
                                kr_redistribute(kr);
                        } else {
add:
                                if ((kr = calloc(1,
                                    sizeof(struct kroute_node))) == NULL) {
                                        log_warn("rtmsg_process calloc");
                                        return (-1);
                                }
                                kr->r.prefix = prefix;
                                kr->r.prefixlen = prefixlen;
                                kr->r.nexthop = nexthop;
                                kr->r.scope = scope;
                                kr->r.flags = flags;
                                kr->r.ifindex = ifindex;
                                kr->r.priority = prio;

                                if (rtm->rtm_priority == kr_state.fib_prio) {
                                        log_warnx("alien OSPF route %s/%d",
                                            log_in6addr(&prefix), prefixlen);
                                        rv = send_rtmsg(kr_state.fd,
                                            RTM_DELETE, &kr->r);
                                        free(kr);
                                        if (rv == -1)
                                                return (-1);
                                } else {
                                        if ((label = (struct sockaddr_rtlabel *)
                                            rti_info[RTAX_LABEL]) != NULL) {
                                                kr->r.rtlabel =
                                                    rtlabel_name2id(
                                                    label->sr_label);
                                                kr->r.ext_tag =
                                                    rtlabel_id2tag(
                                                    kr->r.rtlabel);
                                        }

                                        kroute_insert(kr);
                                }
                        }
                        break;
                case RTM_DELETE:
                        if ((kr = kroute_find(&prefix, prefixlen, prio)) ==
                            NULL)
                                continue;
                        if (!(kr->r.flags & F_KERNEL))
                                continue;
                        /* get the correct route */
                        okr = kr;
                        if (mpath && (kr = kroute_matchgw(kr, &nexthop,
                            scope)) == NULL) {
                                log_warnx("rtmsg_process mpath route"
                                    " not found");
                                return (-1);
                        }
                        if (kroute_remove(kr) == -1)
                                return (-1);
                        break;
                case RTM_IFINFO:
                        memcpy(&ifm, next, sizeof(ifm));
                        if_change(ifm.ifm_index, ifm.ifm_flags, &ifm.ifm_data,
                            (struct sockaddr_dl *)rti_info[RTAX_IFP]);
                        break;
                case RTM_NEWADDR:
                        ifam = (struct ifa_msghdr *)rtm;
                        if ((ifam->ifam_addrs & (RTA_NETMASK | RTA_IFA |
                            RTA_BRD)) == 0)
                                break;

                        if_newaddr(ifam->ifam_index,
                            (struct sockaddr_in6 *)rti_info[RTAX_IFA],
                            (struct sockaddr_in6 *)rti_info[RTAX_NETMASK],
                            (struct sockaddr_in6 *)rti_info[RTAX_BRD]);
                        break;
                case RTM_DELADDR:
                        ifam = (struct ifa_msghdr *)rtm;
                        if ((ifam->ifam_addrs & (RTA_NETMASK | RTA_IFA |
                            RTA_BRD)) == 0)
                                break;

                        if_deladdr(ifam->ifam_index,
                            (struct sockaddr_in6 *)rti_info[RTAX_IFA],
                            (struct sockaddr_in6 *)rti_info[RTAX_NETMASK],
                            (struct sockaddr_in6 *)rti_info[RTAX_BRD]);
                        break;
                case RTM_IFANNOUNCE:
                        if_announce(next);
                        break;
                case RTM_DESYNC:
                        /*
                         * We lost some routing packets. Schedule a reload
                         * of the kernel route/interface information.
                         */
                        if (kr_state.reload_state == KR_RELOAD_IDLE) {
                                delay = KR_RELOAD_TIMER;
                                log_info("desync; scheduling fib reload");
                        } else {
                                delay = KR_RELOAD_HOLD_TIMER;
                                log_debug("desync during KR_RELOAD_%s",
                                    kr_state.reload_state ==
                                    KR_RELOAD_FETCH ? "FETCH" : "HOLD");
                        }
                        kr_state.reload_state = KR_RELOAD_FETCH;
                        kr_fib_reload_arm_timer(delay);
                        break;
                default:
                        /* ignore for now */
                        break;
                }
        }
        return (offset);
}