/*      $OpenBSD: ospfd.c,v 1.124 2024/11/21 13:38:14 claudio Exp $ */

/*
 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
 * Copyright (c) 2004 Esben Norby <norby@openbsd.org>
 * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/queue.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/sysctl.h>
#include <syslog.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if_types.h>

#include <event.h>
#include <err.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>

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

void            main_sig_handler(int, short, void *);
__dead void     usage(void);
__dead void     ospfd_shutdown(void);

void    main_dispatch_ospfe(int, short, void *);
void    main_dispatch_rde(int, short, void *);

int     ospf_reload(void);
int     ospf_sendboth(enum imsg_type, void *, u_int16_t);
int     merge_interfaces(struct area *, struct area *);
struct iface *iface_lookup(struct area *, struct iface *);

int     pipe_parent2ospfe[2];
int     pipe_parent2rde[2];
int     pipe_ospfe2rde[2];

enum ospfd_process       ospfd_process;
struct ospfd_conf       *ospfd_conf = NULL;
static struct imsgev    *iev_ospfe;
static struct imsgev    *iev_rde;
char                    *conffile;

pid_t                    ospfe_pid = 0;
pid_t                    rde_pid = 0;

void
main_sig_handler(int sig, short event, void *arg)
{
        /* signal handler rules don't apply, libevent decouples for us */
        switch (sig) {
        case SIGTERM:
        case SIGINT:
                ospfd_shutdown();
                /* NOTREACHED */
        case SIGHUP:
                if (ospf_reload() == -1)
                        log_warnx("configuration reload failed");
                else
                        log_debug("configuration reloaded");
                break;
        default:
                fatalx("unexpected signal");
                /* NOTREACHED */
        }
}

__dead void
usage(void)
{
        extern char *__progname;

        fprintf(stderr, "usage: %s [-cdnv] [-D macro=value]"
            " [-f file] [-s socket]\n",
            __progname);
        exit(1);
}

int
main(int argc, char *argv[])
{
        struct event             ev_sigint, ev_sigterm, ev_sighup;
        struct area             *a;
        int                      ch, opts = 0;
        int                      debug = 0;
        int                      ipforwarding;
        int                      mib[4];
        size_t                   len;
        char                    *sockname = NULL;
        int                      control_fd;

        conffile = CONF_FILE;
        ospfd_process = PROC_MAIN;

        log_init(1, LOG_DAEMON);        /* log to stderr until daemonized */
        log_procinit(log_procnames[ospfd_process]);

        while ((ch = getopt(argc, argv, "cdD:f:ns:v")) != -1) {
                switch (ch) {
                case 'c':
                        opts |= OSPFD_OPT_FORCE_DEMOTE;
                        break;
                case 'd':
                        debug = 1;
                        break;
                case 'D':
                        if (cmdline_symset(optarg) < 0)
                                log_warnx("could not parse macro definition %s",
                                    optarg);
                        break;
                case 'f':
                        conffile = optarg;
                        break;
                case 'n':
                        opts |= OSPFD_OPT_NOACTION;
                        break;
                case 's':
                        sockname = optarg;
                        break;
                case 'v':
                        if (opts & OSPFD_OPT_VERBOSE)
                                opts |= OSPFD_OPT_VERBOSE2;
                        opts |= OSPFD_OPT_VERBOSE;
                        log_setverbose(1);
                        break;
                default:
                        usage();
                        /* NOTREACHED */
                }
        }

        argc -= optind;
        argv += optind;
        if (argc > 0)
                usage();

        mib[0] = CTL_NET;
        mib[1] = PF_INET;
        mib[2] = IPPROTO_IP;
        mib[3] = IPCTL_FORWARDING;
        len = sizeof(ipforwarding);
        if (sysctl(mib, 4, &ipforwarding, &len, NULL, 0) == -1)
                err(1, "sysctl");

        if (ipforwarding != 1) {
                log_warnx("WARNING: IP forwarding NOT enabled, "
                    "running as stub router");
                opts |= OSPFD_OPT_STUB_ROUTER;
        }

        /* fetch interfaces early */
        kif_init();

        /* parse config file */
        if ((ospfd_conf = parse_config(conffile, opts)) == NULL) {
                kif_clear();
                exit(1);
        }
        if (ospfd_conf->rtr_id.s_addr == 0)
                ospfd_conf->rtr_id.s_addr = get_rtr_id();

        if (sockname == NULL) {
                if (asprintf(&sockname, "%s.%d", OSPFD_SOCKET,
                    ospfd_conf->rdomain) == -1)
                        err(1, "asprintf");
        }

        ospfd_conf->csock = sockname;

        if (ospfd_conf->opts & OSPFD_OPT_NOACTION) {
                if (ospfd_conf->opts & OSPFD_OPT_VERBOSE)
                        print_config(ospfd_conf);
                else
                        fprintf(stderr, "configuration OK\n");
                kif_clear();
                exit(0);
        }

        /* check for root privileges  */
        if (geteuid())
                errx(1, "need root privileges");

        /* check for ospfd user */
        if (getpwnam(OSPFD_USER) == NULL)
                errx(1, "unknown user %s", OSPFD_USER);

        log_init(debug, LOG_DAEMON);
        log_setverbose(ospfd_conf->opts & OSPFD_OPT_VERBOSE);

        if ((control_check(ospfd_conf->csock)) == -1)
                fatalx("ospfd already running");

        if (!debug)
                daemon(1, 0);

        log_info("startup");

        if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
            PF_UNSPEC, pipe_parent2ospfe) == -1)
                fatal("socketpair");
        if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
            PF_UNSPEC, pipe_parent2rde) == -1)
                fatal("socketpair");
        if (socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
            PF_UNSPEC, pipe_ospfe2rde) == -1)
                fatal("socketpair");

        /* start children */
        rde_pid = rde(ospfd_conf, pipe_parent2rde, pipe_ospfe2rde,
            pipe_parent2ospfe);
        ospfe_pid = ospfe(ospfd_conf, pipe_parent2ospfe, pipe_ospfe2rde,
            pipe_parent2rde);

        event_init();

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

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

        if ((iev_ospfe = malloc(sizeof(struct imsgev))) == NULL ||
            (iev_rde = malloc(sizeof(struct imsgev))) == NULL)
                fatal(NULL);
        if (imsgbuf_init(&iev_ospfe->ibuf, pipe_parent2ospfe[0]) == -1)
                fatal(NULL);
        imsgbuf_allow_fdpass(&iev_ospfe->ibuf);
        iev_ospfe->handler = main_dispatch_ospfe;
        if (imsgbuf_init(&iev_rde->ibuf, pipe_parent2rde[0]) == -1)
                fatal(NULL);
        iev_rde->handler = main_dispatch_rde;

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

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

        if ((control_fd = control_init(ospfd_conf->csock)) == -1)
                fatalx("control socket setup failed");
        main_imsg_compose_ospfe_fd(IMSG_CONTROLFD, 0, control_fd);

        if (unveil("/", "r") == -1)
                fatal("unveil /");
        if (unveil(NULL, NULL) == -1)
                fatal("unveil");

        if (kr_init(!(ospfd_conf->flags & OSPFD_FLAG_NO_FIB_UPDATE),
            ospfd_conf->rdomain, ospfd_conf->redist_label_or_prefix,
            ospfd_conf->fib_priority) == -1)
                fatalx("kr_init failed");

        /* remove unneeded stuff from config */
        while ((a = LIST_FIRST(&ospfd_conf->area_list)) != NULL) {
                LIST_REMOVE(a, entry);
                area_del(a);
        }

        event_dispatch();

        ospfd_shutdown();
        /* NOTREACHED */
        return (0);
}

__dead void
ospfd_shutdown(void)
{
        pid_t                    pid;
        int                      status;
        struct redistribute     *r;

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

        control_cleanup();
        while ((r = SIMPLEQ_FIRST(&ospfd_conf->redist_list)) != NULL) {
                SIMPLEQ_REMOVE_HEAD(&ospfd_conf->redist_list, entry);
                free(r);
        }
        kr_shutdown();
        carp_demote_shutdown();

        log_debug("waiting for children to terminate");
        do {
                pid = wait(&status);
                if (pid == -1) {
                        if (errno != EINTR && errno != ECHILD)
                                fatal("wait");
                } else if (WIFSIGNALED(status))
                        log_warnx("%s terminated; signal %d",
                            (pid == rde_pid) ? "route decision engine" :
                            "ospf engine", WTERMSIG(status));
        } while (pid != -1 || (pid == -1 && errno == EINTR));

        free(iev_ospfe);
        free(iev_rde);
        free(ospfd_conf);

        log_info("terminating");
        exit(0);
}

/* imsg handling */
void
main_dispatch_ospfe(int fd, short event, void *bula)
{
        struct imsgev           *iev = bula;
        struct imsgbuf          *ibuf;
        struct imsg              imsg;
        struct demote_msg        dmsg;
        ssize_t                  n;
        int                      shut = 0, verbose;

        ibuf = &iev->ibuf;

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

        for (;;) {
                if ((n = imsg_get(ibuf, &imsg)) == -1)
                        fatal("imsg_get");

                if (n == 0)
                        break;

                switch (imsg.hdr.type) {
                case IMSG_CTL_RELOAD:
                        if (ospf_reload() == -1)
                                log_warnx("configuration reload failed");
                        else
                                log_debug("configuration reloaded");
                        break;
                case IMSG_CTL_FIB_COUPLE:
                        kr_fib_couple();
                        break;
                case IMSG_CTL_FIB_DECOUPLE:
                        kr_fib_decouple();
                        break;
                case IMSG_CTL_FIB_RELOAD:
                        kr_fib_reload();
                        break;
                case IMSG_CTL_KROUTE:
                case IMSG_CTL_KROUTE_ADDR:
                        kr_show_route(&imsg);
                        break;
                case IMSG_CTL_IFINFO:
                        if (imsg.hdr.len == IMSG_HEADER_SIZE)
                                kr_ifinfo(NULL, imsg.hdr.pid);
                        else if (imsg.hdr.len == IMSG_HEADER_SIZE + IFNAMSIZ)
                                kr_ifinfo(imsg.data, imsg.hdr.pid);
                        else
                                log_warnx("IFINFO request with wrong len");
                        break;
                case IMSG_DEMOTE:
                        if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(dmsg))
                                fatalx("invalid size of OE request");
                        memcpy(&dmsg, imsg.data, sizeof(dmsg));
                        carp_demote_set(dmsg.demote_group, dmsg.level);
                        break;
                case IMSG_CTL_LOG_VERBOSE:
                        /* already checked by ospfe */
                        memcpy(&verbose, imsg.data, sizeof(verbose));
                        log_setverbose(verbose);
                        break;
                default:
                        log_debug("main_dispatch_ospfe: error handling imsg %d",
                            imsg.hdr.type);
                        break;
                }
                imsg_free(&imsg);
        }
        if (!shut)
                imsg_event_add(iev);
        else {
                /* this pipe is dead, so remove the event handler */
                event_del(&iev->ev);
                event_loopexit(NULL);
        }
}

void
main_dispatch_rde(int fd, short event, void *bula)
{
        struct imsgev   *iev = bula;
        struct imsgbuf  *ibuf;
        struct imsg      imsg;
        ssize_t          n;
        int              count, shut = 0;

        ibuf = &iev->ibuf;

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

        for (;;) {
                if ((n = imsg_get(ibuf, &imsg)) == -1)
                        fatal("imsg_get");

                if (n == 0)
                        break;

                switch (imsg.hdr.type) {
                case IMSG_KROUTE_CHANGE:
                        count = (imsg.hdr.len - IMSG_HEADER_SIZE) /
                            sizeof(struct kroute);
                        if (kr_change(imsg.data, count))
                                log_warn("main_dispatch_rde: error changing "
                                    "route");
                        break;
                case IMSG_KROUTE_DELETE:
                        if (kr_delete(imsg.data))
                                log_warn("main_dispatch_rde: error deleting "
                                    "route");
                        break;
                default:
                        log_debug("main_dispatch_rde: error handling imsg %d",
                            imsg.hdr.type);
                        break;
                }
                imsg_free(&imsg);
        }
        if (!shut)
                imsg_event_add(iev);
        else {
                /* this pipe is dead, so remove the event handler */
                event_del(&iev->ev);
                event_loopexit(NULL);
        }
}

void
main_imsg_compose_ospfe(int type, pid_t pid, void *data, u_int16_t datalen)
{
        if (iev_ospfe)
                imsg_compose_event(iev_ospfe, type, 0, pid, -1, data, datalen);
}

void
main_imsg_compose_ospfe_fd(int type, pid_t pid, int fd)
{
        if (iev_ospfe)
                imsg_compose_event(iev_ospfe, type, 0, pid, fd, NULL, 0);
}

void
main_imsg_compose_rde(int type, pid_t pid, void *data, u_int16_t datalen)
{
        if (iev_rde)
                imsg_compose_event(iev_rde, type, 0, pid, -1, data, datalen);
}

void
imsg_event_add(struct imsgev *iev)
{
        iev->events = EV_READ;
        if (imsgbuf_queuelen(&iev->ibuf) > 0)
                iev->events |= EV_WRITE;

        event_del(&iev->ev);
        event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev);
        event_add(&iev->ev, NULL);
}

int
imsg_compose_event(struct imsgev *iev, u_int16_t type, u_int32_t peerid,
    pid_t pid, int fd, void *data, u_int16_t datalen)
{
        int     ret;

        if ((ret = imsg_compose(&iev->ibuf, type, peerid,
            pid, fd, data, datalen)) != -1)
                imsg_event_add(iev);
        return (ret);
}

int
ospf_redistribute(struct kroute *kr, u_int32_t *metric)
{
        struct in_addr           addr;
        struct kif              *kif;
        struct redistribute     *r;
        int                      is_default, depend_ok;

        bzero(&addr, sizeof(addr));

        /* only allow 0.0.0.0/0 via REDIST_DEFAULT */
        is_default = (kr->prefix.s_addr == INADDR_ANY && kr->prefixlen == 0);

        SIMPLEQ_FOREACH(r, &ospfd_conf->redist_list, entry) {
                if (r->dependon[0] != '\0') {
                        if ((kif = kif_findname(r->dependon, addr, NULL)))
                                depend_ok = ifstate_is_up(kif);
                        else
                                depend_ok = 0;
                } else
                        depend_ok = 1;

                switch (r->type & ~REDIST_NO) {
                case REDIST_LABEL:
                        if (kr->rtlabel == r->label) {
                                *metric = depend_ok ? r->metric :
                                    r->metric | MAX_METRIC;
                                return (r->type & REDIST_NO ? 0 : 1);
                        }
                        break;
                case REDIST_STATIC:
                        /*
                         * Dynamic routes are not redistributable. Placed here
                         * so that link local addresses can be redistributed
                         * via a rtlabel.
                         */
                        if (is_default)
                                continue;
                        if (kr->flags & F_DYNAMIC)
                                continue;
                        if (kr->flags & F_STATIC) {
                                *metric = depend_ok ? r->metric :
                                    r->metric | MAX_METRIC;
                                return (r->type & REDIST_NO ? 0 : 1);
                        }
                        break;
                case REDIST_CONNECTED:
                        if (is_default)
                                continue;
                        if (kr->flags & F_DYNAMIC)
                                continue;
                        if (kr->flags & F_CONNECTED) {
                                *metric = depend_ok ? r->metric :
                                    r->metric | MAX_METRIC;
                                return (r->type & REDIST_NO ? 0 : 1);
                        }
                        break;
                case REDIST_ADDR:
                        if (kr->flags & F_DYNAMIC)
                                continue;

                        if (r->addr.s_addr == INADDR_ANY &&
                            r->mask.s_addr == INADDR_ANY) {
                                if (is_default) {
                                        *metric = depend_ok ? r->metric :
                                            r->metric | MAX_METRIC;
                                        return (r->type & REDIST_NO ? 0 : 1);
                                } else
                                        return (0);
                        }

                        if ((kr->prefix.s_addr & r->mask.s_addr) ==
                            (r->addr.s_addr & r->mask.s_addr) &&
                            kr->prefixlen >= mask2prefixlen(r->mask.s_addr)) {
                                *metric = depend_ok ? r->metric :
                                    r->metric | MAX_METRIC;
                                return (r->type & REDIST_NO ? 0 : 1);
                        }
                        break;
                case REDIST_DEFAULT:
                        if (is_default) {
                                *metric = depend_ok ? r->metric :
                                    r->metric | MAX_METRIC;
                                return (r->type & REDIST_NO ? 0 : 1);
                        }
                        break;
                }
        }

        return (0);
}

int
ospf_reload(void)
{
        struct area             *area;
        struct iface            *iface;
        struct ospfd_conf       *xconf;
        struct redistribute     *r;

        if ((xconf = parse_config(conffile, ospfd_conf->opts)) == NULL)
                return (-1);

        /* No router-id was specified, keep existing value */
        if (xconf->rtr_id.s_addr == 0)
                xconf->rtr_id.s_addr = ospfd_conf->rtr_id.s_addr;

        /* Abort the reload if rtr_id changed */
        if (ospfd_conf->rtr_id.s_addr != xconf->rtr_id.s_addr) {
                log_warnx("router-id changed: restart required");
                return (-1);
        }

        /* send config to childs */
        if (ospf_sendboth(IMSG_RECONF_CONF, xconf, sizeof(*xconf)) == -1)
                return (-1);

        /* send interfaces */
        LIST_FOREACH(area, &xconf->area_list, entry) {
                if (ospf_sendboth(IMSG_RECONF_AREA, area, sizeof(*area)) == -1)
                        return (-1);

                SIMPLEQ_FOREACH(r, &area->redist_list, entry) {
                        main_imsg_compose_rde(IMSG_RECONF_REDIST, 0, r,
                            sizeof(*r));
                }
                LIST_FOREACH(iface, &area->iface_list, entry) {
                        if (ospf_sendboth(IMSG_RECONF_IFACE, iface,
                            sizeof(*iface)) == -1)
                                return (-1);
                        if (iface->auth_type == AUTH_CRYPT)
                                if (md_list_send(&iface->auth_md_list,
                                    iev_ospfe) == -1)
                                        return (-1);
                }
        }

        if (ospf_sendboth(IMSG_RECONF_END, NULL, 0) == -1)
                return (-1);

        merge_config(ospfd_conf, xconf);
        /* update redistribute lists */
        kr_reload(ospfd_conf->redist_label_or_prefix);
        return (0);
}

int
ospf_sendboth(enum imsg_type type, void *buf, u_int16_t len)
{
        if (imsg_compose_event(iev_ospfe, type, 0, 0, -1, buf, len) == -1)
                return (-1);
        if (imsg_compose_event(iev_rde, type, 0, 0, -1, buf, len) == -1)
                return (-1);
        return (0);
}

void
merge_config(struct ospfd_conf *conf, struct ospfd_conf *xconf)
{
        struct area             *a, *xa, *na;
        struct iface            *iface;
        struct redistribute     *r;
        int                      rchange = 0;

        conf->flags = xconf->flags;
        conf->spf_delay = xconf->spf_delay;
        conf->spf_hold_time = xconf->spf_hold_time;
        if (SIMPLEQ_EMPTY(&conf->redist_list) !=
            SIMPLEQ_EMPTY(&xconf->redist_list))
                rchange = 1;
        conf->rfc1583compat = xconf->rfc1583compat;
        conf->redist_label_or_prefix = xconf->redist_label_or_prefix;

        if (ospfd_process == PROC_MAIN) {
                /* main process does neither use areas nor interfaces */
                while ((r = SIMPLEQ_FIRST(&conf->redist_list)) != NULL) {
                        SIMPLEQ_REMOVE_HEAD(&conf->redist_list, entry);
                        free(r);
                }
                SIMPLEQ_CONCAT(&conf->redist_list, &xconf->redist_list);

                /* adjust FIB priority if changed */
                if (conf->fib_priority != xconf->fib_priority) {
                        kr_fib_decouple();
                        kr_fib_update_prio(xconf->fib_priority);
                        conf->fib_priority = xconf->fib_priority;
                        kr_fib_couple();
                }

                goto done;
        }

        /* merge areas and interfaces */
        for (a = LIST_FIRST(&conf->area_list); a != NULL; a = na) {
                na = LIST_NEXT(a, entry);
                /* find deleted areas */
                if ((xa = area_find(xconf, a->id)) == NULL) {
                        if (ospfd_process == PROC_OSPF_ENGINE) {
                                LIST_FOREACH(iface, &a->iface_list, entry)
                                        if_fsm(iface, IF_EVT_DOWN);
                        }
                        LIST_REMOVE(a, entry);
                        area_del(a);
                }
        }

        for (xa = LIST_FIRST(&xconf->area_list); xa != NULL; xa = na) {
                na = LIST_NEXT(xa, entry);
                if ((a = area_find(conf, xa->id)) == NULL) {
                        LIST_REMOVE(xa, entry);
                        LIST_INSERT_HEAD(&conf->area_list, xa, entry);
                        if (ospfd_process == PROC_OSPF_ENGINE) {
                                /* start interfaces */
                                ospfe_demote_area(xa, 0);
                                LIST_FOREACH(iface, &xa->iface_list, entry) {
                                        if_init(conf, iface);
                                        if (if_fsm(iface, IF_EVT_UP)) {
                                                log_debug("error starting "
                                                    "interface %s",
                                                    iface->name);
                                        }
                                }
                        }
                        /* no need to merge interfaces */
                        continue;
                }
                /*
                 * stub is not yet used but switching between stub and normal
                 * will be another painful job.
                 */
                if (a->stub != xa->stub && ospfd_process == PROC_OSPF_ENGINE)
                        a->dirty = 1; /* force rtr LSA update */
                if (xa->stub && ospfd_process == PROC_RDE_ENGINE) {
                        while ((r = SIMPLEQ_FIRST(&a->redist_list)) != NULL) {
                                SIMPLEQ_REMOVE_HEAD(&a->redist_list, entry);
                                free(r);
                        }

                        SIMPLEQ_CONCAT(&a->redist_list, &xa->redist_list);
                }

                a->stub = xa->stub;
                a->stub_default_cost = xa->stub_default_cost;
                if (ospfd_process == PROC_RDE_ENGINE)
                        a->dirty = 1; /* force SPF tree recalculation */

                /* merge interfaces */
                if (merge_interfaces(a, xa) &&
                    ospfd_process == PROC_OSPF_ENGINE)
                        a->dirty = 1; /* force rtr LSA update */
        }

        if (ospfd_process == PROC_OSPF_ENGINE) {
                LIST_FOREACH(a, &conf->area_list, entry) {
                        LIST_FOREACH(iface, &a->iface_list, entry) {
                                if (iface->state == IF_STA_NEW) {
                                        iface->state = IF_STA_DOWN;
                                        if_init(conf, iface);
                                        if (if_fsm(iface, IF_EVT_UP)) {
                                                log_debug("error starting "
                                                    "interface %s",
                                                    iface->name);
                                        }
                                }
                        }
                        if (a->dirty || rchange) {
                                a->dirty = 0;
                                orig_rtr_lsa(a);
                        }
                }
        }
        if (ospfd_process == PROC_RDE_ENGINE) {
                LIST_FOREACH(a, &conf->area_list, entry) {
                        if (a->dirty) {
                                start_spf_timer();
                                break;
                        }
                }
        }

done:
        while ((a = LIST_FIRST(&xconf->area_list)) != NULL) {
                LIST_REMOVE(a, entry);
                area_del(a);
        }
        free(xconf);
}

int
merge_interfaces(struct area *a, struct area *xa)
{
        struct iface    *i, *xi, *ni;
        int              dirty = 0;

        /* problems:
         * - new interfaces (easy)
         * - deleted interfaces
         * - changing passive (painful?)
         */
        for (i = LIST_FIRST(&a->iface_list); i != NULL; i = ni) {
                ni = LIST_NEXT(i, entry);
                if (iface_lookup(xa, i) == NULL) {
                        log_debug("merge_interfaces: proc %d area %s removing "
                            "interface %s", ospfd_process, inet_ntoa(a->id),
                            i->name);
                        if (ospfd_process == PROC_OSPF_ENGINE)
                                if_fsm(i, IF_EVT_DOWN);
                        else if (ospfd_process == PROC_RDE_ENGINE)
                                rde_nbr_iface_del(i);
                        LIST_REMOVE(i, entry);
                        if_del(i);
                        dirty = 1; /* force rtr LSA update */
                }
        }

        for (xi = LIST_FIRST(&xa->iface_list); xi != NULL; xi = ni) {
                ni = LIST_NEXT(xi, entry);
                if ((i = iface_lookup(a, xi)) == NULL) {
                        /* new interface but delay initialisation */
                        log_debug("merge_interfaces: proc %d area %s adding "
                            "interface %s", ospfd_process, inet_ntoa(a->id),
                            xi->name);
                        LIST_REMOVE(xi, entry);
                        LIST_INSERT_HEAD(&a->iface_list, xi, entry);
                        xi->area = a;
                        if (ospfd_process == PROC_OSPF_ENGINE)
                                xi->state = IF_STA_NEW;
                        continue;
                }
                log_debug("merge_interfaces: proc %d area %s merging "
                    "interface %s", ospfd_process, inet_ntoa(a->id), i->name);
                i->dst = xi->dst;
                i->abr_id = xi->abr_id;
                i->baudrate = xi->baudrate;
                i->dead_interval = xi->dead_interval;
                i->mtu = xi->mtu;
                i->transmit_delay = xi->transmit_delay;
                i->hello_interval = xi->hello_interval;
                i->rxmt_interval = xi->rxmt_interval;
                if (i->metric != xi->metric)
                        dirty = 1;
                i->metric = xi->metric;
                i->priority = xi->priority;
                if (i->self)
                        i->self->priority = i->priority;
                i->flags = xi->flags; /* needed? */
                i->if_type = xi->if_type; /* needed? */
                i->linkstate = xi->linkstate; /* needed? */

                i->auth_type = xi->auth_type;
                strncpy(i->auth_key, xi->auth_key, MAX_SIMPLE_AUTH_LEN);
                md_list_clr(&i->auth_md_list);
                md_list_copy(&i->auth_md_list, &xi->auth_md_list);

                strlcpy(i->dependon, xi->dependon,
                        sizeof(i->dependon));
                i->depend_ok = xi->depend_ok;

                if (i->passive != xi->passive) {
                        /* need to restart interface to cope with this change */
                        if (ospfd_process == PROC_OSPF_ENGINE)
                                if_fsm(i, IF_EVT_DOWN);
                        i->passive = xi->passive;
                        if (ospfd_process == PROC_OSPF_ENGINE)
                                if_fsm(i, IF_EVT_UP);
                }

                if (i->type != xi->type) {
                        /* restart interface to enable or disable DR election */
                        if (ospfd_process == PROC_OSPF_ENGINE)
                                if_fsm(i, IF_EVT_DOWN);
                        i->type = xi->type;
                        if (ospfd_process == PROC_OSPF_ENGINE)
                                if_fsm(i, IF_EVT_UP);
                }
        }
        return (dirty);
}

struct iface *
iface_lookup(struct area *area, struct iface *iface)
{
        struct iface    *i;

        LIST_FOREACH(i, &area->iface_list, entry)
                if (i->ifindex == iface->ifindex &&
                    i->addr.s_addr == iface->addr.s_addr &&
                    i->mask.s_addr == iface->mask.s_addr)
                        return (i);
        return (NULL);
}

int
ifstate_is_up(struct kif *kif)
{
        if (!(kif->flags & IFF_UP))
                return (0);
        if (kif->if_type == IFT_CARP &&
            kif->link_state == LINK_STATE_UNKNOWN)
                return (0);
        return LINK_STATE_IS_UP(kif->link_state);
}