/*      $OpenBSD: kroute.c,v 1.37 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 "rip.h"
#include "ripd.h"
#include "log.h"

struct {
        u_int32_t               rtseq;
        pid_t                   pid;
        int                     fib_sync;
        u_int8_t                fib_prio;
        int                     fd;
        struct event            ev;
        u_int                   rdomain;
} kr_state;

struct kroute_node {
        RB_ENTRY(kroute_node)    entry;
        struct kroute            r;
};

struct kif_node {
        RB_ENTRY(kif_node)       entry;
        struct kif               k;
};

void    kr_redistribute(int, struct kroute *);
int     kroute_compare(struct kroute_node *, struct kroute_node *);
int     kif_compare(struct kif_node *, struct kif_node *);
int     kr_change_fib(struct kroute_node *, struct kroute *, int);

struct kroute_node      *kroute_find(in_addr_t, in_addr_t, u_int8_t);
int                      kroute_insert(struct kroute_node *);
int                      kroute_remove(struct kroute_node *);
void                     kroute_clear(void);

struct kif_node         *kif_find(int);
int                      kif_insert(struct kif_node *);
int                      kif_remove(struct kif_node *);
void                     kif_clear(void);
int                      kif_validate(int);

struct kroute_node      *kroute_match(in_addr_t);

int             protect_lo(void);
u_int8_t        prefixlen_classful(in_addr_t);
void            get_rtaddrs(int, struct sockaddr *, struct sockaddr **);
void            if_change(u_short, int, struct if_data *);
void            if_announce(void *);

int             send_rtmsg(int, int, struct kroute *);
int             dispatch_rtmsg(void);
int             fetchtable(void);
int             fetchifs(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)

RB_HEAD(kif_tree, kif_node)             kit;
RB_PROTOTYPE(kif_tree, kif_node, entry, kif_compare)
RB_GENERATE(kif_tree, kif_node, entry, kif_compare)

int
kif_init(void)
{
        RB_INIT(&kit);

        if (fetchifs(0) == -1)
                return (-1);

        return (0);
}

int
kr_init(int fs, u_int rdomain, u_int8_t fib_prio)
{
        int             opt = 0, rcvbuf, default_rcvbuf;
        socklen_t       optlen;

        if ((kr_state.fd = socket(AF_ROUTE,
            SOCK_RAW | SOCK_CLOEXEC | SOCK_NONBLOCK, 0)) == -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 */

        /* 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;
        kr_state.fib_prio = fib_prio;

        RB_INIT(&krt);

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

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

        kr_state.fib_sync = fs; /* now set correct sync mode */
        kr_state.rdomain = rdomain;

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

        return (0);
}

int
kr_change_fib(struct kroute_node *kr, struct kroute *kroute, int action)
{
        /* nexthop within 127/8 -> ignore silently */
        if ((kroute->nexthop.s_addr & htonl(IN_CLASSA_NET)) ==
            htonl(INADDR_LOOPBACK & IN_CLASSA_NET))
                return (0);

        if (send_rtmsg(kr_state.fd, action, kroute) == -1)
                return (-1);

        if (action == RTM_ADD) {
                if ((kr = calloc(1, sizeof(struct kroute_node))) == NULL)
                        fatal("kr_change_fib");

                kr->r.prefix.s_addr = kroute->prefix.s_addr;
                kr->r.netmask.s_addr = kroute->netmask.s_addr;
                kr->r.nexthop.s_addr = kroute->nexthop.s_addr;
                kr->r.flags = kroute->flags |= F_RIPD_INSERTED;
                kr->r.priority = kr_state.fib_prio;

                if (kroute_insert(kr) == -1) {
                        log_debug("kr_update_fib: cannot insert %s",
                            inet_ntoa(kroute->nexthop));
                }
        } else
                kr->r.nexthop.s_addr = kroute->nexthop.s_addr;

        return (0);
}

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

        kr = kroute_find(kroute->prefix.s_addr, kroute->netmask.s_addr,
            kr_state.fib_prio);
        if (kr != NULL)
                action = RTM_CHANGE;

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

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

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

        if (kr->r.priority != kr_state.fib_prio)
                log_warn("kr_delete_fib: %s/%d has wrong priority %d",
                    inet_ntoa(kr->r.prefix), mask2prefixlen(kr->r.netmask.s_addr),
                    kr->r.priority);

        if (send_rtmsg(kr_state.fd, RTM_DELETE, kroute) == -1)
                return (-1);

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

        return (0);
}

void
kr_shutdown(void)
{
        kr_fib_decouple();

        kroute_clear();
        kif_clear();
}

void
kr_fib_couple(void)
{
        struct kroute_node      *kr;

        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)
                        send_rtmsg(kr_state.fd, RTM_ADD, &kr->r);

        log_info("kernel routing table coupled");
}

void
kr_fib_decouple(void)
{
        struct kroute_node      *kr;

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

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

        kr_state.fib_sync = 0;

        log_info("kernel routing table decoupled");
}

void
kr_dispatch_msg(int fd, short event, void *bula)
{
        dispatch_rtmsg();
}

void
kr_show_route(struct imsg *imsg)
{
        struct kroute_node      *kr;
        int                      flags;
        struct in_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) {
                                main_imsg_compose_ripe(IMSG_CTL_KROUTE,
                                    imsg->hdr.pid, &kr->r, sizeof(kr->r));
                        }
                break;
        case IMSG_CTL_KROUTE_ADDR:
                if (imsg->hdr.len != IMSG_HEADER_SIZE +
                    sizeof(struct in_addr)) {
                        log_warnx("kr_show_route: wrong imsg len");
                        return;
                }
                memcpy(&addr, imsg->data, sizeof(addr));
                kr = NULL;
                kr = kroute_match(addr.s_addr);
                if (kr != NULL)
                        main_imsg_compose_ripe(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_ripe(IMSG_CTL_END, imsg->hdr.pid, NULL, 0);
}

void
kr_ifinfo(char *ifname, pid_t pid)
{
        struct kif_node *kif;

        RB_FOREACH(kif, kif_tree, &kit)
                if (ifname == NULL || !strcmp(ifname, kif->k.ifname)) {
                        main_imsg_compose_ripe(IMSG_CTL_IFINFO,
                            pid, &kif->k, sizeof(kif->k));
                }

        main_imsg_compose_ripe(IMSG_CTL_END, pid, NULL, 0);
}

void
kr_redistribute(int type, struct kroute *kr)
{
        u_int32_t       a;


        if (type == IMSG_NETWORK_DEL) {
dont_redistribute:
                /* was the route redistributed? */
                if (kr->flags & F_REDISTRIBUTED) {
                        /* remove redistributed flag */
                        kr->flags &= ~F_REDISTRIBUTED;
                        main_imsg_compose_rde(type, 0, kr,
                            sizeof(struct kroute));
                }
                return;
        }

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

        /*
         * We consider the loopback net and multicast addresses
         * as not redistributable.
         */
        a = ntohl(kr->prefix.s_addr);
        if (IN_MULTICAST(a) || (a >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
                return;
        /*
         * Consider networks with nexthop loopback as not redistributable
         * unless it is a reject or blackhole route.
         */
        if (kr->nexthop.s_addr == htonl(INADDR_LOOPBACK) &&
            !(kr->flags & (F_BLACKHOLE|F_REJECT)))
                return;

        /* Should we redistribute this route? */
        if (!rip_redistribute(kr))
                goto dont_redistribute;

        /* Does not matter if we resend the kr, the RDE will cope. */
        kr->flags |= F_REDISTRIBUTED;
        main_imsg_compose_rde(type, 0, kr, sizeof(struct kroute));
}

/* rb-tree compare */
int
kroute_compare(struct kroute_node *a, struct kroute_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 (ntohl(a->r.netmask.s_addr) < ntohl(b->r.netmask.s_addr))
                return (-1);
        if (ntohl(a->r.netmask.s_addr) > ntohl(b->r.netmask.s_addr))
                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);
}

int
kif_compare(struct kif_node *a, struct kif_node *b)
{
        return (b->k.ifindex - a->k.ifindex);
}

/* tree management */
struct kroute_node *
kroute_find(in_addr_t prefix, in_addr_t netmask, u_int8_t prio)
{
        struct kroute_node      s, *kn, *tmp;

        s.r.prefix.s_addr = prefix;
        s.r.netmask.s_addr = netmask;
        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);
}

int
kroute_insert(struct kroute_node *kr)
{
        if (RB_INSERT(kroute_tree, &krt, kr) != NULL) {
                log_warnx("kroute_insert failed for %s/%u",
                    inet_ntoa(kr->r.prefix),
                    mask2prefixlen(kr->r.netmask.s_addr));
                free(kr);
                return (-1);
        }

        if (!(kr->r.flags & F_KERNEL)) {
                /* don't validate or redistribute rip 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(IMSG_NETWORK_ADD, &kr->r);

        return (0);
}

int
kroute_remove(struct kroute_node *kr)
{
        if (RB_REMOVE(kroute_tree, &krt, kr) == NULL) {
                log_warnx("kroute_remove failed for %s/%u",
                    inet_ntoa(kr->r.prefix),
                    mask2prefixlen(kr->r.netmask.s_addr));
                return (-1);
        }

        kr_redistribute(IMSG_NETWORK_DEL, &kr->r);
        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 kif_node *
kif_find(int ifindex)
{
        struct kif_node s;

        bzero(&s, sizeof(s));
        s.k.ifindex = ifindex;

        return (RB_FIND(kif_tree, &kit, &s));
}

struct kif *
kif_findname(char *ifname)
{
        struct kif_node *kif;

        RB_FOREACH(kif, kif_tree, &kit)
                if (!strcmp(ifname, kif->k.ifname))
                        return (&kif->k);

        return (NULL);
}

int
kif_insert(struct kif_node *kif)
{
        if (RB_INSERT(kif_tree, &kit, kif) != NULL) {
                log_warnx("RB_INSERT(kif_tree, &kit, kif)");
                free(kif);
                return (-1);
        }

        return (0);
}

int
kif_remove(struct kif_node *kif)
{
        if (RB_REMOVE(kif_tree, &kit, kif) == NULL) {
                log_warnx("RB_REMOVE(kif_tree, &kit, kif)");
                return (-1);
        }

        free(kif);
        return (0);
}

void
kif_clear(void)
{
        struct kif_node *kif;

        while ((kif = RB_MIN(kif_tree, &kit)) != NULL)
                kif_remove(kif);
}

int
kif_validate(int ifindex)
{
        struct kif_node         *kif;

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

        return (kif->k.nh_reachable);
}

struct kroute_node *
kroute_match(in_addr_t key)
{
        u_int8_t                 i;
        struct kroute_node      *kr;

        /* we will never match the default route */
        for (i = 32; i > 0; i--)
                if ((kr = kroute_find(key & prefixlen2mask(i),
                    prefixlen2mask(i), RTP_ANY)) != NULL)
                        return (kr);

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

        return (NULL);
}

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

        /* special protection for 127/8 */
        if ((kr = calloc(1, sizeof(struct kroute_node))) == NULL) {
                log_warn("protect_lo");
                return (-1);
        }
        kr->r.prefix.s_addr = htonl(INADDR_LOOPBACK);
        kr->r.netmask.s_addr = htonl(IN_CLASSA_NET);
        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);
}

u_int8_t
prefixlen_classful(in_addr_t ina)
{
        /* it hurt to write this. */

        if (ina >= 0xf0000000U)         /* class E */
                return (32);
        else if (ina >= 0xe0000000U)    /* class D */
                return (4);
        else if (ina >= 0xc0000000U)    /* class C */
                return (24);
        else if (ina >= 0x80000000U)    /* class B */
                return (16);
        else                            /* class A */
                return (8);
}

u_int8_t
mask2prefixlen(in_addr_t ina)
{
        if (ina == 0)
                return (0);
        else
                return (33 - ffs(ntohl(ina)));
}

in_addr_t
prefixlen2mask(u_int8_t prefixlen)
{
        if (prefixlen == 0)
                return (0);

        return (htonl(0xffffffff << (32 - prefixlen)));
}

#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 kif_node         *kif;
        struct kroute_node      *kr;
        int                      type;
        u_int8_t                 reachable;

        if ((kif = kif_find(ifindex)) == NULL) {
                log_warnx("interface with index %u not found", ifindex);
                return;
        }

        kif->k.flags = flags;
        kif->k.link_state = ifd->ifi_link_state;
        kif->k.if_type = ifd->ifi_type;
        kif->k.baudrate = ifd->ifi_baudrate;

        if ((reachable = (flags & IFF_UP) &&
            LINK_STATE_IS_UP(ifd->ifi_link_state)) == kif->k.nh_reachable)
                return;         /* nothing changed wrt nexthop validity */

        kif->k.nh_reachable = reachable;
        type = reachable ? IMSG_NETWORK_ADD : IMSG_NETWORK_DEL;

        /* notify ripe about interface link state */
        main_imsg_compose_ripe(IMSG_IFINFO, 0, &kif->k, sizeof(kif->k));

        /* update redistribute list */
        RB_FOREACH(kr, kroute_tree, &krt)
                if (kr->r.ifindex == ifindex) {
                        if (reachable)
                                kr->r.flags &= ~F_DOWN;
                        else
                                kr->r.flags |= F_DOWN;

                        kr_redistribute(type, &kr->r);
                }
}

void
if_announce(void *msg)
{
        struct if_announcemsghdr        *ifan;
        struct kif_node                 *kif;

        ifan = msg;

        switch (ifan->ifan_what) {
        case IFAN_ARRIVAL:
                if ((kif = calloc(1, sizeof(struct kif_node))) == NULL) {
                        log_warn("if_announce");
                        return;
                }

                kif->k.ifindex = ifan->ifan_index;
                strlcpy(kif->k.ifname, ifan->ifan_name, sizeof(kif->k.ifname));
                kif_insert(kif);
                break;
        case IFAN_DEPARTURE:
                kif = kif_find(ifan->ifan_index);
                if (kif != NULL)
                        kif_remove(kif);
                break;
        }
}

/* rtsock */
int
send_rtmsg(int fd, int action, struct kroute *kroute)
{
        struct iovec            iov[4];
        struct rt_msghdr        hdr;
        struct sockaddr_in      prefix;
        struct sockaddr_in      nexthop;
        struct sockaddr_in      mask;
        int                     iovcnt = 0;

        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;
        if (action == RTM_CHANGE)
                hdr.rtm_fmask = RTF_REJECT|RTF_BLACKHOLE;
        hdr.rtm_seq = kr_state.rtseq++; /* overflow doesn't matter */
        hdr.rtm_msglen = sizeof(hdr);
        /* adjust iovec */
        iov[iovcnt].iov_base = &hdr;
        iov[iovcnt++].iov_len = sizeof(hdr);

        bzero(&prefix, sizeof(prefix));
        prefix.sin_len = sizeof(prefix);
        prefix.sin_family = AF_INET;
        prefix.sin_addr.s_addr = kroute->prefix.s_addr;
        /* adjust header */
        hdr.rtm_addrs |= RTA_DST;
        hdr.rtm_msglen += sizeof(prefix);
        /* adjust iovec */
        iov[iovcnt].iov_base = &prefix;
        iov[iovcnt++].iov_len = sizeof(prefix);

        if (kroute->nexthop.s_addr != 0) {
                bzero(&nexthop, sizeof(nexthop));
                nexthop.sin_len = sizeof(nexthop);
                nexthop.sin_family = AF_INET;
                nexthop.sin_addr.s_addr = kroute->nexthop.s_addr;
                /* adjust header */
                hdr.rtm_flags |= RTF_GATEWAY;
                hdr.rtm_addrs |= RTA_GATEWAY;
                hdr.rtm_msglen += sizeof(nexthop);
                /* adjust iovec */
                iov[iovcnt].iov_base = &nexthop;
                iov[iovcnt++].iov_len = sizeof(nexthop);
        }

        bzero(&mask, sizeof(mask));
        mask.sin_len = sizeof(mask);
        mask.sin_family = AF_INET;
        mask.sin_addr.s_addr = kroute->netmask.s_addr;
        /* adjust header */
        hdr.rtm_addrs |= RTA_NETMASK;
        hdr.rtm_msglen += sizeof(mask);
        /* adjust iovec */
        iov[iovcnt].iov_base = &mask;
        iov[iovcnt++].iov_len = sizeof(mask);


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",
                                    inet_ntoa(kroute->prefix),
                                    mask2prefixlen(kroute->netmask.s_addr));
                                return (0);
                        }
                }
                log_warn("send_rtmsg: action %u, prefix %s/%u",
                    hdr.rtm_type, inet_ntoa(kroute->prefix),
                    mask2prefixlen(kroute->netmask.s_addr));
                return (0);
        }

        return (0);
}

int
fetchtable(void)
{
        size_t                   len;
        int                      mib[7];
        char                    *buf, *next, *lim;
        struct rt_msghdr        *rtm;
        struct sockaddr         *sa, *rti_info[RTAX_MAX];
        struct sockaddr_in      *sa_in;
        struct sockaddr_rtlabel *label;
        struct kroute_node      *kr;
        struct iface            *iface = NULL;

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = AF_INET;
        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);
        }

        lim = buf + len;
        for (next = buf; next < lim; next += rtm->rtm_msglen) {
                rtm = (struct rt_msghdr *)next;
                if (rtm->rtm_version != RTM_VERSION)
                        continue;
                sa = (struct sockaddr *)(next + rtm->rtm_hdrlen);
                get_rtaddrs(rtm->rtm_addrs, sa, rti_info);

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

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

#ifdef RTF_MPATH
                if (rtm->rtm_flags & RTF_MPATH)         /* multipath */
                        continue;
#endif

                if ((kr = calloc(1, sizeof(struct kroute_node))) == NULL) {
                        log_warn("fetchtable");
                        free(buf);
                        return (-1);
                }

                kr->r.flags = F_KERNEL;
                kr->r.priority = rtm->rtm_priority;

                switch (sa->sa_family) {
                case AF_INET:
                        kr->r.prefix.s_addr =
                            ((struct sockaddr_in *)sa)->sin_addr.s_addr;
                        sa_in = (struct sockaddr_in *)rti_info[RTAX_NETMASK];
                        if (rtm->rtm_flags & RTF_STATIC)
                                kr->r.flags |= F_STATIC;
                        if (rtm->rtm_flags & RTF_BLACKHOLE)
                                kr->r.flags |= F_BLACKHOLE;
                        if (rtm->rtm_flags & RTF_REJECT)
                                kr->r.flags |= F_REJECT;
                        if (rtm->rtm_flags & RTF_DYNAMIC)
                                kr->r.flags |= F_DYNAMIC;
                        if (sa_in != NULL) {
                                if (sa_in->sin_len == 0)
                                        break;
                                kr->r.netmask.s_addr =
                                    sa_in->sin_addr.s_addr;
                        } else if (rtm->rtm_flags & RTF_HOST)
                                kr->r.netmask.s_addr = prefixlen2mask(32);
                        else
                                kr->r.netmask.s_addr =
                                    prefixlen2mask(prefixlen_classful
                                        (kr->r.prefix.s_addr));
                        break;
                default:
                        free(kr);
                        continue;
                }

                kr->r.ifindex = rtm->rtm_index;

                iface = if_find_index(rtm->rtm_index);
                if (iface != NULL)
                        kr->r.metric = iface->cost;
                else
                        kr->r.metric = DEFAULT_COST;

                if ((sa = rti_info[RTAX_GATEWAY]) != NULL)
                        switch (sa->sa_family) {
                        case AF_INET:
                                if (rtm->rtm_flags & RTF_CONNECTED) {
                                        kr->r.flags |= F_CONNECTED;
                                        break;
                                }

                                kr->r.nexthop.s_addr =
                                    ((struct sockaddr_in *)sa)->sin_addr.s_addr;
                                break;
                        case AF_LINK:
                                /*
                                 * Traditional BSD connected routes have
                                 * a gateway of type AF_LINK.
                                 */
                                kr->r.flags |= F_CONNECTED;
                                break;
                        }

                if (rtm->rtm_priority == kr_state.fib_prio) {
                        send_rtmsg(kr_state.fd, RTM_DELETE, &kr->r);
                        free(kr);
                } else {
                        if ((label = (struct sockaddr_rtlabel *)
                            rti_info[RTAX_LABEL]) != NULL)
                                kr->r.rtlabel =
                                    rtlabel_name2id(label->sr_label);
                        kroute_insert(kr);
                }

        }
        free(buf);
        return (0);
}

int
fetchifs(int ifindex)
{
        size_t                   len;
        int                      mib[6];
        char                    *buf, *next, *lim;
        struct if_msghdr         ifm;
        struct kif_node         *kif;
        struct sockaddr         *sa, *rti_info[RTAX_MAX];
        struct sockaddr_dl      *sdl;

        mib[0] = CTL_NET;
        mib[1] = PF_ROUTE;
        mib[2] = 0;
        mib[3] = AF_INET;
        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("fetchif");
                return (-1);
        }
        if (sysctl(mib, 6, buf, &len, NULL, 0) == -1) {
                log_warn("sysctl");
                free(buf);
                return (-1);
        }

        lim = buf + len;
        for (next = buf; next < lim; next += ifm.ifm_msglen) {
                memcpy(&ifm, next, sizeof(ifm));
                if (ifm.ifm_version != RTM_VERSION)
                        continue;
                if (ifm.ifm_type != RTM_IFINFO)
                        continue;

                sa = (struct sockaddr *)(next + sizeof(ifm));
                get_rtaddrs(ifm.ifm_addrs, sa, rti_info);

                if ((kif = calloc(1, sizeof(struct kif_node))) == NULL) {
                        log_warn("fetchifs");
                        free(buf);
                        return (-1);
                }

                kif->k.ifindex = ifm.ifm_index;
                kif->k.flags = ifm.ifm_flags;
                kif->k.link_state = ifm.ifm_data.ifi_link_state;
                kif->k.if_type = ifm.ifm_data.ifi_type;
                kif->k.baudrate = ifm.ifm_data.ifi_baudrate;
                kif->k.mtu = ifm.ifm_data.ifi_mtu;
                kif->k.nh_reachable = (kif->k.flags & IFF_UP) &&
                    LINK_STATE_IS_UP(ifm.ifm_data.ifi_link_state);
                if ((sa = rti_info[RTAX_IFP]) != NULL)
                        if (sa->sa_family == AF_LINK) {
                                sdl = (struct sockaddr_dl *)sa;
                                if (sdl->sdl_nlen >= sizeof(kif->k.ifname))
                                        memcpy(kif->k.ifname, sdl->sdl_data,
                                            sizeof(kif->k.ifname) - 1);
                                else if (sdl->sdl_nlen > 0)
                                        memcpy(kif->k.ifname, sdl->sdl_data,
                                            sdl->sdl_nlen);
                                /* string already terminated via calloc() */
                        }

                kif_insert(kif);
        }
        free(buf);
        return (0);
}

int
dispatch_rtmsg(void)
{
        char                     buf[RT_BUF_SIZE];
        ssize_t                  n;
        char                    *next, *lim;
        struct rt_msghdr        *rtm;
        struct if_msghdr         ifm;
        struct sockaddr         *sa, *rti_info[RTAX_MAX];
        struct sockaddr_in      *sa_in;
        struct sockaddr_rtlabel *label;
        struct kroute_node      *kr;
        struct in_addr           prefix, nexthop, netmask;
        struct iface            *iface = NULL;
        int                      flags;
        u_short                  ifindex = 0;
        u_int8_t                 metric, prio;

        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);
        }

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

                prefix.s_addr = 0;
                netmask.s_addr = 0;
                flags = F_KERNEL;
                nexthop.s_addr = 0;
                prio = 0;

                if (rtm->rtm_type == RTM_ADD || rtm->rtm_type == RTM_CHANGE ||
                    rtm->rtm_type == RTM_DELETE) {
                        sa = (struct sockaddr *)(next + rtm->rtm_hdrlen);
                        get_rtaddrs(rtm->rtm_addrs, sa, rti_info);

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

                        if (rtm->rtm_pid == kr_state.pid)       /* cause by us */
                                continue;

                        if (rtm->rtm_errno)                     /* failed attempts... */
                                continue;

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

                        prio = rtm->rtm_priority;

                        switch (sa->sa_family) {
                        case AF_INET:
                                prefix.s_addr =
                                    ((struct sockaddr_in *)sa)->sin_addr.s_addr;
                                sa_in = (struct sockaddr_in *)
                                    rti_info[RTAX_NETMASK];
                                if (sa_in != NULL) {
                                        if (sa_in->sin_len != 0)
                                                netmask.s_addr =
                                                    sa_in->sin_addr.s_addr;
                                } else if (rtm->rtm_flags & RTF_HOST)
                                        netmask.s_addr = prefixlen2mask(32);
                                else
                                        netmask.s_addr =
                                            prefixlen2mask(prefixlen_classful(
                                                prefix.s_addr));
                                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_INET:
                                        nexthop.s_addr = ((struct
                                            sockaddr_in *)sa)->sin_addr.s_addr;
                                        break;
                                case AF_LINK:
                                        flags |= F_CONNECTED;
                                        break;
                                }
                        }
                }

                switch (rtm->rtm_type) {
                case RTM_ADD:
                case RTM_CHANGE:
                        if (nexthop.s_addr == 0 && !(flags & F_CONNECTED)) {
                                log_warnx("dispatch_rtmsg no nexthop for %s/%u",
                                    inet_ntoa(prefix),
                                    mask2prefixlen(netmask.s_addr));
                                continue;
                        }

                        if ((kr = kroute_find(prefix.s_addr, netmask.s_addr,
                            prio)) != NULL) {
                                if (kr->r.flags & F_REDISTRIBUTED)
                                        flags |= F_REDISTRIBUTED;
                                kr->r.nexthop.s_addr = nexthop.s_addr;
                                kr->r.flags = flags;
                                kr->r.ifindex = ifindex;
                                kr->r.priority = prio;

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

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

                                /* just readd, the RDE will care */
                                kr_redistribute(IMSG_NETWORK_ADD, &kr->r);
                        } else {
                                if ((kr = calloc(1,
                                    sizeof(struct kroute_node))) == NULL) {
                                        log_warn("dispatch_rtmsg");
                                        return (-1);
                                }

                                iface = if_find_index(rtm->rtm_index);
                                if (iface != NULL)
                                        metric = iface->cost;
                                else
                                        metric = DEFAULT_COST;

                                kr->r.prefix.s_addr = prefix.s_addr;
                                kr->r.netmask.s_addr = netmask.s_addr;
                                kr->r.nexthop.s_addr = nexthop.s_addr;
                                kr->r.metric = metric;
                                kr->r.flags = flags;
                                kr->r.ifindex = ifindex;

                                if ((label = (struct sockaddr_rtlabel *)
                                    rti_info[RTAX_LABEL]) != NULL)
                                        kr->r.rtlabel =
                                            rtlabel_name2id(label->sr_label);

                                kroute_insert(kr);
                        }
                        break;
                case RTM_DELETE:
                        if ((kr = kroute_find(prefix.s_addr, netmask.s_addr,
                            prio)) == NULL)
                                continue;
                        if (!(kr->r.flags & F_KERNEL))
                                continue;
                        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);
                        break;
                case RTM_IFANNOUNCE:
                        if_announce(next);
                        break;
                default:
                        /* ignore for now */
                        break;
                }
        }
        return (0);
}