localedef(1): eliminate need for "print" definition

[dragonfly.git] / usr.sbin / rtadvd / config.c

/*      $KAME: config.c,v 1.37 2001/05/25 07:34:00 itojun Exp $ */

/*
 * Copyright (C) 1998 WIDE Project.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: src/usr.sbin/rtadvd/config.c,v 1.3.2.5 2003/04/22 09:40:57 suz Exp $
 */

#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/sysctl.h>

#include <net/if.h>
#if defined(__DragonFly__) 
#include <net/if_var.h>
#endif /* __DragonFly__  */
#include <net/route.h>
#include <net/if_dl.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#ifdef MIP6
#include <netinet6/mip6.h>
#endif

#include <arpa/inet.h>

#include <stdio.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <search.h>
#include <unistd.h>
#include <ifaddrs.h>

#include "rtadvd.h"
#include "advcap.h"
#include "timer.h"
#include "if.h"
#include "config.h"

static time_t prefix_timo = (60 * 120); /* 2 hours.
                                         * XXX: should be configurable. */
extern struct rainfo *ralist;

static struct rtadvd_timer *prefix_timeout(void *);
static void makeentry(char *, size_t, int, char *, int);
static void get_prefix(struct rainfo *);
static int getinet6sysctl(int);

void
getconfig(char *intface)
{
        int stat, pfxs, i;
        char tbuf[BUFSIZ];
        struct rainfo *tmp;
        long val;
        long long val64;
        char buf[BUFSIZ];
        char *bp = buf;
        char *addr;
        static int forwarding = -1;

#define MUSTHAVE(var, cap)      \
    do {                                                                \
        int t;                                                          \
        if ((t = agetnum(cap)) < 0) {                                   \
                fprintf(stderr, "rtadvd: need %s for interface %s\n",   \
                        cap, intface);                                  \
                exit(1);                                                \
        }                                                               \
        var = t;                                                        \
     } while (0)
#define MAYHAVE(var, cap, def)  \
     do {                                                               \
        if ((var = agetnum(cap)) < 0)                                   \
                var = def;                                              \
     } while (0)

        if ((stat = agetent(tbuf, intface)) <= 0) {
                memset(tbuf, 0, sizeof(tbuf));
                syslog(LOG_INFO,
                       "<%s> %s isn't defined in the configuration file"
                       " or the configuration file doesn't exist."
                       " Treat it as default",
                        __func__, intface);
        }

        tmp = (struct rainfo *)malloc(sizeof(*ralist));
        memset(tmp, 0, sizeof(*tmp));
        tmp->prefix.next = tmp->prefix.prev = &tmp->prefix;
        tmp->route.next = tmp->route.prev = &tmp->route;

        /* check if we are allowed to forward packets (if not determined) */
        if (forwarding < 0) {
                if ((forwarding = getinet6sysctl(IPV6CTL_FORWARDING)) < 0)
                        exit(1);
        }

        /* get interface information */
        if (agetflag("nolladdr"))
                tmp->advlinkopt = 0;
        else
                tmp->advlinkopt = 1;
        if (tmp->advlinkopt) {
                if ((tmp->sdl = if_nametosdl(intface)) == NULL) {
                        syslog(LOG_ERR,
                               "<%s> can't get information of %s",
                               __func__, intface);
                        exit(1);
                }
                tmp->ifindex = tmp->sdl->sdl_index;
        } else
                tmp->ifindex = if_nametoindex(intface);
        strncpy(tmp->ifname, intface, sizeof(tmp->ifname));
        if ((tmp->phymtu = if_getmtu(intface)) == 0) {
                tmp->phymtu = IPV6_MMTU;
                syslog(LOG_WARNING,
                       "<%s> can't get interface mtu of %s. Treat as %d",
                       __func__, intface, IPV6_MMTU);
        }

        /*
         * set router configuration variables.
         */
        MAYHAVE(val, "maxinterval", DEF_MAXRTRADVINTERVAL);
        if (val < MIN_MAXINTERVAL || val > MAX_MAXINTERVAL) {
                syslog(LOG_ERR,
                       "<%s> maxinterval must be between %e and %u",
                       __func__, MIN_MAXINTERVAL, MAX_MAXINTERVAL);
                exit(1);
        }
        tmp->maxinterval = (u_int)val;
        MAYHAVE(val, "mininterval", tmp->maxinterval/3);
        if (val < MIN_MININTERVAL || val > (tmp->maxinterval * 3) / 4) {
                syslog(LOG_ERR,
                       "<%s> mininterval must be between %e and %d",
                       __func__,
                       MIN_MININTERVAL,
                       (tmp->maxinterval * 3) / 4);
                exit(1);
        }
        tmp->mininterval = (u_int)val;

        MAYHAVE(val, "chlim", DEF_ADVCURHOPLIMIT);
        tmp->hoplimit = val & 0xff;

        MAYHAVE(val, "raflags", 0);
        tmp->managedflg = val & ND_RA_FLAG_MANAGED;
        tmp->otherflg = val & ND_RA_FLAG_OTHER;
#ifdef MIP6
        if (mobileip6)
                tmp->haflg = val & ND_RA_FLAG_HA;
#endif
#ifndef ND_RA_FLAG_RTPREF_MASK
#define ND_RA_FLAG_RTPREF_MASK  0x18 /* 00011000 */
#define ND_RA_FLAG_RTPREF_RSV   0x10 /* 00010000 */
#endif
        tmp->rtpref = val & ND_RA_FLAG_RTPREF_MASK;
        if (tmp->rtpref == ND_RA_FLAG_RTPREF_RSV) {
                syslog(LOG_ERR, "<%s> invalid router preference on %s",
                       __func__, intface);
                exit(1);
        }

        MAYHAVE(val, "rltime", tmp->maxinterval * 3);
        if (val && (val < tmp->maxinterval || val > MAXROUTERLIFETIME)) {
                syslog(LOG_ERR,
                       "<%s> router lifetime on %s must be 0 or"
                       " between %d and %d",
                       __func__, intface,
                       tmp->maxinterval, MAXROUTERLIFETIME);
                exit(1);
        }
        /*
         * Basically, hosts MUST NOT send Router Advertisement messages at any
         * time (RFC 2461, Section 6.2.3). However, it would sometimes be
         * useful to allow hosts to advertise some parameters such as prefix
         * information and link MTU. Thus, we allow hosts to invoke rtadvd
         * only when router lifetime (on every advertising interface) is
         * explicitly set zero. (see also the above section)
         */
        if (val && forwarding == 0) {
                syslog(LOG_WARNING,
                       "<%s> non zero router lifetime is specified for %s, "
                       "which must not be allowed for hosts.",
                       __func__, intface);
                exit(1);
        }
        tmp->lifetime = val & 0xffff;

        MAYHAVE(val, "rtime", DEF_ADVREACHABLETIME);
        if (val > MAXREACHABLETIME) {
                syslog(LOG_ERR,
                       "<%s> reachable time must be no greater than %d",
                       __func__, MAXREACHABLETIME);
                exit(1);
        }
        tmp->reachabletime = (u_int32_t)val;

        MAYHAVE(val64, "retrans", DEF_ADVRETRANSTIMER);
        if (val64 < 0 || val64 > 0xffffffff) {
                syslog(LOG_ERR,
                       "<%s> retrans time out of range", __func__);
                exit(1);
        }
        tmp->retranstimer = (u_int32_t)val64;

#ifndef MIP6
        if (agetstr("hapref", &bp) || agetstr("hatime", &bp)) {
                syslog(LOG_ERR,
                       "<%s> mobile-ip6 configuration not supported",
                       __func__);
                exit(1);
        }
#else
        if (!mobileip6) {
                if (agetstr("hapref", &bp) || agetstr("hatime", &bp)) {
                        syslog(LOG_ERR,
                               "<%s> mobile-ip6 configuration without "
                               "proper command line option",
                               __func__);
                        exit(1);
                }
        } else {
                tmp->hapref = 0;
                if ((val = agetnum("hapref")) >= 0)
                        tmp->hapref = (int16_t)val;
                if (tmp->hapref != 0) {
                        tmp->hatime = 0;
                        MUSTHAVE(val, "hatime");
                        tmp->hatime = (u_int16_t)val;
                        if (tmp->hatime <= 0) {
                                syslog(LOG_ERR,
                                       "<%s> home agent lifetime must be greater than 0",
                                       __func__);
                                exit(1);
                        }
                }
        }
#endif

        /* prefix information */

        /*
         * This is an implementation specific parameter to consinder
         * link propagation delays and poorly synchronized clocks when
         * checking consistency of advertised lifetimes.
         */
        MAYHAVE(val, "clockskew", 0);
        tmp->clockskew = val;

        if ((pfxs = agetnum("addrs")) < 0) {
                /* auto configure prefix information */
                if (agetstr("addr", &bp) || agetstr("addr1", &bp)) {
                        syslog(LOG_ERR,
                               "<%s> conflicting prefix configuration for %s: "
                               "automatic and manual config at the same time",
                               __func__, intface);
                        exit(1);
                }
                get_prefix(tmp);
        }
        else {
                tmp->pfxs = pfxs;
                for (i = 0; i < pfxs; i++) {
                        struct prefix *pfx;
                        char entbuf[256];
                        int added = (pfxs > 1) ? 1 : 0;

                        /* allocate memory to store prefix information */
                        if ((pfx = malloc(sizeof(struct prefix))) == NULL) {
                                syslog(LOG_ERR,
                                       "<%s> can't allocate enough memory",
                                       __func__);
                                exit(1);
                        }
                        memset(pfx, 0, sizeof(*pfx));

                        /* link into chain */
                        insque(pfx, &tmp->prefix);
                        pfx->rainfo = tmp;

                        pfx->origin = PREFIX_FROM_CONFIG;

                        makeentry(entbuf, sizeof(entbuf), i, "prefixlen",
                            added);
                        MAYHAVE(val, entbuf, 64);
                        if (val < 0 || val > 128) {
                                syslog(LOG_ERR,
                                       "<%s> prefixlen out of range",
                                       __func__);
                                exit(1);
                        }
                        pfx->prefixlen = (int)val;

                        makeentry(entbuf, sizeof(entbuf), i, "pinfoflags",
                            added);
#ifdef MIP6
                        if (mobileip6)
                        {
                                MAYHAVE(val, entbuf,
                                    (ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO|
                                         ND_OPT_PI_FLAG_ROUTER));
                        } else
#endif
                        {
                                MAYHAVE(val, entbuf,
                                    (ND_OPT_PI_FLAG_ONLINK|ND_OPT_PI_FLAG_AUTO));
                        }
                        pfx->onlinkflg = val & ND_OPT_PI_FLAG_ONLINK;
                        pfx->autoconfflg = val & ND_OPT_PI_FLAG_AUTO;
#ifdef MIP6
                        pfx->routeraddr = val & ND_OPT_PI_FLAG_ROUTER;
#endif

                        makeentry(entbuf, sizeof(entbuf), i, "vltime", added);
                        MAYHAVE(val64, entbuf, DEF_ADVVALIDLIFETIME);
                        if (val64 < 0 || val64 > 0xffffffff) {
                                syslog(LOG_ERR,
                                       "<%s> vltime out of range",
                                       __func__);
                                exit(1);
                        }
                        pfx->validlifetime = (u_int32_t)val64;

                        makeentry(entbuf, sizeof(entbuf), i, "vltimedecr",
                            added);
                        if (agetflag(entbuf)) {
                                struct timeval now;
                                gettimeofday(&now, 0);
                                pfx->vltimeexpire =
                                        now.tv_sec + pfx->validlifetime;
                        }

                        makeentry(entbuf, sizeof(entbuf), i, "pltime", added);
                        MAYHAVE(val64, entbuf, DEF_ADVPREFERREDLIFETIME);
                        if (val64 < 0 || val64 > 0xffffffff) {
                                syslog(LOG_ERR,
                                       "<%s> pltime out of range",
                                       __func__);
                                exit(1);
                        }
                        pfx->preflifetime = (u_int32_t)val64;

                        makeentry(entbuf, sizeof(entbuf), i, "pltimedecr",
                            added);
                        if (agetflag(entbuf)) {
                                struct timeval now;
                                gettimeofday(&now, 0);
                                pfx->pltimeexpire =
                                        now.tv_sec + pfx->preflifetime;
                        }

                        makeentry(entbuf, sizeof(entbuf), i, "addr", added);
                        addr = (char *)agetstr(entbuf, &bp);
                        if (addr == NULL) {
                                syslog(LOG_ERR,
                                       "<%s> need %s as an prefix for "
                                       "interface %s",
                                       __func__, entbuf, intface);
                                exit(1);
                        }
                        if (inet_pton(AF_INET6, addr,
                                      &pfx->prefix) != 1) {
                                syslog(LOG_ERR,
                                       "<%s> inet_pton failed for %s",
                                       __func__, addr);
                                exit(1);
                        }
                        if (IN6_IS_ADDR_MULTICAST(&pfx->prefix)) {
                                syslog(LOG_ERR,
                                       "<%s> multicast prefix(%s) must "
                                       "not be advertised (IF=%s)",
                                       __func__, addr, intface);
                                exit(1);
                        }
                        if (IN6_IS_ADDR_LINKLOCAL(&pfx->prefix))
                                syslog(LOG_NOTICE,
                                       "<%s> link-local prefix(%s) will be"
                                       " advertised on %s",
                                       __func__, addr, intface);
                }
        }

        MAYHAVE(val, "mtu", 0);
        if (val < 0 || val > 0xffffffff) {
                syslog(LOG_ERR,
                       "<%s> mtu out of range", __func__);
                exit(1);
        }
        tmp->linkmtu = (u_int32_t)val;
        if (tmp->linkmtu == 0) {
                char *mtustr;

                if ((mtustr = (char *)agetstr("mtu", &bp)) &&
                    strcmp(mtustr, "auto") == 0)
                        tmp->linkmtu = tmp->phymtu;
        }
        else if (tmp->linkmtu < IPV6_MMTU || tmp->linkmtu > tmp->phymtu) {
                syslog(LOG_ERR,
                       "<%s> advertised link mtu must be between"
                       " least MTU and physical link MTU",
                       __func__);
                exit(1);
        }

        /* route information */

        MAYHAVE(val, "routes", 0);
        if (val < 0 || val > 0xffffffff) {
                syslog(LOG_ERR,
                       "<%s> number of route information improper", __func__);
                exit(1);
        }
        tmp->routes = val;
        for (i = 0; i < tmp->routes; i++) {
                struct rtinfo *rti;
                char entbuf[256];
                int added = (tmp->routes > 1) ? 1 : 0;

                /* allocate memory to store prefix information */
                if ((rti = malloc(sizeof(struct rtinfo))) == NULL) {
                        syslog(LOG_ERR,
                               "<%s> can't allocate enough memory",
                               __func__);
                        exit(1);
                }
                memset(rti, 0, sizeof(*rti));

                /* link into chain */
                insque(rti, &tmp->route);

                makeentry(entbuf, sizeof(entbuf), i, "rtrplen", added);
                MAYHAVE(val, entbuf, 64);
                if (val < 0 || val > 128) {
                        syslog(LOG_ERR,
                               "<%s> prefixlen out of range",
                               __func__);
                        exit(1);
                }
                rti->prefixlen = (int)val;

                makeentry(entbuf, sizeof(entbuf), i, "rtrflags", added);
                MAYHAVE(val, entbuf, 0);
                rti->rtpref = val & ND_RA_FLAG_RTPREF_MASK;
                if (rti->rtpref == ND_RA_FLAG_RTPREF_RSV) {
                        syslog(LOG_ERR, "<%s> invalid route preference",
                               __func__);
                        exit(1);
                }

                makeentry(entbuf, sizeof(entbuf), i, "rtrltime", added);
                /*
                 * XXX: since default value of route lifetime is not defined in
                 * draft-draves-route-selection-01.txt, I took the default 
                 * value of valid lifetime of prefix as its default.
                 * It need be much considered.
                 */
                MAYHAVE(val64, entbuf, DEF_ADVVALIDLIFETIME);
                if (val64 < 0 || val64 > 0xffffffff) {
                        syslog(LOG_ERR,
                               "<%s> rtrltime out of range",
                               __func__);
                        exit(1);
                }
                rti->ltime = (u_int32_t)val64;

                makeentry(entbuf, sizeof(entbuf), i, "rtrprefix", added);
                addr = (char *)agetstr(entbuf, &bp);
                if (addr == NULL) {
                        syslog(LOG_ERR,
                               "<%s> need %s as an route for "
                               "interface %s",
                               __func__, entbuf, intface);
                        exit(1);
                }
                if (inet_pton(AF_INET6, addr, &rti->prefix) != 1) {
                        syslog(LOG_ERR,
                               "<%s> inet_pton failed for %s",
                               __func__, addr);
                        exit(1);
                }
#if 0
                /*
                 * XXX: currently there's no restriction in route information
                 * prefix according to draft-draves-route-selection-01.txt,
                 * however I think the similar restriction be necessary.
                 */
                MAYHAVE(val64, entbuf, DEF_ADVVALIDLIFETIME);
                if (IN6_IS_ADDR_MULTICAST(&rti->prefix)) {
                        syslog(LOG_ERR,
                               "<%s> multicast route (%s) must "
                               "not be advertised (IF=%s)",
                               __func__, addr, intface);
                        exit(1);
                }
                if (IN6_IS_ADDR_LINKLOCAL(&rti->prefix)) {
                        syslog(LOG_NOTICE,
                               "<%s> link-local route (%s) must "
                               "not be advertised on %s",
                               __func__, addr, intface);
                        exit(1);
                }
#endif
        }

        /* okey */
        tmp->next = ralist;
        ralist = tmp;

        /* construct the sending packet */
        make_packet(tmp);

        /* set timer */
        tmp->timer = rtadvd_add_timer(ra_timeout, ra_timer_update,
                                      tmp, tmp);
        ra_timer_update((void *)tmp, &tmp->timer->tm);
        rtadvd_set_timer(&tmp->timer->tm, tmp->timer);
}

static void
get_prefix(struct rainfo *rai)
{
        struct ifaddrs *ifap, *ifa;
        struct prefix *pp;
        struct in6_addr *a;
        u_char *p, *ep, *m, *lim;
        u_char ntopbuf[INET6_ADDRSTRLEN];

        if (getifaddrs(&ifap) < 0) {
                syslog(LOG_ERR,
                       "<%s> can't get interface addresses",
                       __func__);
                exit(1);
        }
        for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
                int plen;

                if (strcmp(ifa->ifa_name, rai->ifname) != 0)
                        continue;
                if (ifa->ifa_addr->sa_family != AF_INET6)
                        continue;
                a = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
                if (IN6_IS_ADDR_LINKLOCAL(a))
                        continue;

                /* get prefix length */
                m = (u_char *)&((struct sockaddr_in6 *)ifa->ifa_netmask)->sin6_addr;
                lim = (u_char *)(ifa->ifa_netmask) + ifa->ifa_netmask->sa_len;
                plen = prefixlen(m, lim);
                if (plen < 0 || plen > 128) {
                        syslog(LOG_ERR, "<%s> failed to get prefixlen "
                               "or prefix is invalid",
                               __func__);
                        exit(1);
                }
                if (find_prefix(rai, a, plen)) {
                        /* ignore a duplicated prefix. */
                        continue;
                }

                /* allocate memory to store prefix info. */
                if ((pp = malloc(sizeof(*pp))) == NULL) {
                        syslog(LOG_ERR,
                               "<%s> can't get allocate buffer for prefix",
                               __func__);
                        exit(1);
                }
                memset(pp, 0, sizeof(*pp));

                /* set prefix, sweep bits outside of prefixlen */
                pp->prefixlen = plen;
                memcpy(&pp->prefix, a, sizeof(*a));
                p = (u_char *)&pp->prefix;
                ep = (u_char *)(&pp->prefix + 1);
                while (m < lim)
                        *p++ &= *m++;
                while (p < ep)
                        *p++ = 0x00;

                if (!inet_ntop(AF_INET6, &pp->prefix, ntopbuf,
                    sizeof(ntopbuf))) {
                        syslog(LOG_ERR, "<%s> inet_ntop failed", __func__);
                        exit(1);
                }
                syslog(LOG_DEBUG,
                       "<%s> add %s/%d to prefix list on %s",
                       __func__, ntopbuf, pp->prefixlen, rai->ifname);

                /* set other fields with protocol defaults */
                pp->validlifetime = DEF_ADVVALIDLIFETIME;
                pp->preflifetime = DEF_ADVPREFERREDLIFETIME;
                pp->onlinkflg = 1;
                pp->autoconfflg = 1;
                pp->origin = PREFIX_FROM_KERNEL;

                /* link into chain */
                insque(pp, &rai->prefix);

                /* counter increment */
                rai->pfxs++;
        }

        freeifaddrs(ifap);
}

static void
makeentry(char *buf, size_t len, int id, char *string, int add)
{
        char *ep = buf + len;

        strcpy(buf, string);
        if (add) {
                char *cp;

                cp = (char *)index(buf, '\0');
                snprintf(cp, ep - cp, "%d", id);
        }
}

/*
 * Add a prefix to the list of specified interface and reconstruct
 * the outgoing packet.
 * The prefix must not be in the list.
 * XXX: other parameter of the prefix(e.g. lifetime) shoule be
 * able to be specified.
 */
static void
add_prefix(struct rainfo *rai, struct in6_prefixreq *ipr)
{
        struct prefix *prefix;
        u_char ntopbuf[INET6_ADDRSTRLEN];

        if ((prefix = malloc(sizeof(*prefix))) == NULL) {
                syslog(LOG_ERR, "<%s> memory allocation failed",
                       __func__);
                return;         /* XXX: error or exit? */
        }
        memset(prefix, 0, sizeof(*prefix));
        prefix->prefix = ipr->ipr_prefix.sin6_addr;
        prefix->prefixlen = ipr->ipr_plen;
        prefix->validlifetime = ipr->ipr_vltime;
        prefix->preflifetime = ipr->ipr_pltime;
        prefix->onlinkflg = ipr->ipr_raf_onlink;
        prefix->autoconfflg = ipr->ipr_raf_auto;
        prefix->origin = PREFIX_FROM_DYNAMIC;

        insque(prefix, &rai->prefix);
        prefix->rainfo = rai;

        syslog(LOG_DEBUG, "<%s> new prefix %s/%d was added on %s",
               __func__, inet_ntop(AF_INET6, &ipr->ipr_prefix.sin6_addr,
                                       ntopbuf, INET6_ADDRSTRLEN),
               ipr->ipr_plen, rai->ifname);

        /* free the previous packet */
        free(rai->ra_data);
        rai->ra_data = NULL;

        /* reconstruct the packet */
        rai->pfxs++;
        make_packet(rai);

        /*
         * reset the timer so that the new prefix will be advertised quickly.
         */
        rai->initcounter = 0;
        ra_timer_update((void *)rai, &rai->timer->tm);
        rtadvd_set_timer(&rai->timer->tm, rai->timer);
}

/*
 * Delete a prefix to the list of specified interface and reconstruct
 * the outgoing packet.
 * The prefix must be in the list.
 */
void
delete_prefix(struct prefix *prefix)
{
        u_char ntopbuf[INET6_ADDRSTRLEN];
        struct rainfo *rai = prefix->rainfo;

        remque(prefix);
        syslog(LOG_DEBUG, "<%s> prefix %s/%d was deleted on %s",
               __func__, inet_ntop(AF_INET6, &prefix->prefix,
                                       ntopbuf, INET6_ADDRSTRLEN),
               prefix->prefixlen, rai->ifname);
        if (prefix->timer)
                rtadvd_remove_timer(&prefix->timer);
        free(prefix);
        rai->pfxs--;
}

void
invalidate_prefix(struct prefix *prefix)
{
        u_char ntopbuf[INET6_ADDRSTRLEN];
        struct timeval timo;
        struct rainfo *rai = prefix->rainfo;

        if (prefix->timer) {    /* sanity check */
                syslog(LOG_ERR,
                    "<%s> assumption failure: timer already exists",
                    __func__);
                exit(1);
        }

        syslog(LOG_DEBUG, "<%s> prefix %s/%d was invalidated on %s, "
            "will expire in %ld seconds", __func__,
            inet_ntop(AF_INET6, &prefix->prefix, ntopbuf, INET6_ADDRSTRLEN),
            prefix->prefixlen, rai->ifname, (long)prefix_timo);

        /* set the expiration timer */
        prefix->timer = rtadvd_add_timer(prefix_timeout, NULL, prefix, NULL);
        if (prefix->timer == NULL) {
                syslog(LOG_ERR, "<%s> failed to add a timer for a prefix. "
                    "remove the prefix", __func__);
                delete_prefix(prefix);
        }
        timo.tv_sec = prefix_timo;
        timo.tv_usec = 0;
        rtadvd_set_timer(&timo, prefix->timer);
}

static struct rtadvd_timer *
prefix_timeout(void *arg)
{
        struct prefix *prefix = (struct prefix *)arg;
        
        delete_prefix(prefix);

        return(NULL);
}

void
update_prefix(struct prefix * prefix)
{
        u_char ntopbuf[INET6_ADDRSTRLEN];
        struct rainfo *rai = prefix->rainfo;

        if (prefix->timer == NULL) { /* sanity check */
                syslog(LOG_ERR,
                    "<%s> assumption failure: timer does not exist",
                    __func__);
                exit(1);
        }

        syslog(LOG_DEBUG, "<%s> prefix %s/%d was re-enabled on %s",
            __func__, inet_ntop(AF_INET6, &prefix->prefix, ntopbuf,
            INET6_ADDRSTRLEN), prefix->prefixlen, rai->ifname);

        /* stop the expiration timer */
        rtadvd_remove_timer(&prefix->timer);
}

/*
 * Try to get an in6_prefixreq contents for a prefix which matches
 * ipr->ipr_prefix and ipr->ipr_plen and belongs to
 * the interface whose name is ipr->ipr_name[].
 */
static int
init_prefix(struct in6_prefixreq *ipr)
{
#if 0
        int s;

        if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
                syslog(LOG_ERR, "<%s> socket: %s", __func__,
                       strerror(errno));
                exit(1);
        }

        if (ioctl(s, SIOCGIFPREFIX_IN6, (caddr_t)ipr) < 0) {
                syslog(LOG_INFO, "<%s> ioctl:SIOCGIFPREFIX %s", __func__,
                       strerror(errno));

                ipr->ipr_vltime = DEF_ADVVALIDLIFETIME;
                ipr->ipr_pltime = DEF_ADVPREFERREDLIFETIME;
                ipr->ipr_raf_onlink = 1;
                ipr->ipr_raf_auto = 1;
                /* omit other field initialization */
        }
        else if (ipr->ipr_origin < PR_ORIG_RR) {
                u_char ntopbuf[INET6_ADDRSTRLEN];

                syslog(LOG_WARNING, "<%s> Added prefix(%s)'s origin %d is"
                       "lower than PR_ORIG_RR(router renumbering)."
                       "This should not happen if I am router", __func__,
                       inet_ntop(AF_INET6, &ipr->ipr_prefix.sin6_addr, ntopbuf,
                                 sizeof(ntopbuf)), ipr->ipr_origin);
                close(s);
                return 1;
        }

        close(s);
        return 0;
#else
        ipr->ipr_vltime = DEF_ADVVALIDLIFETIME;
        ipr->ipr_pltime = DEF_ADVPREFERREDLIFETIME;
        ipr->ipr_raf_onlink = 1;
        ipr->ipr_raf_auto = 1;
        return 0;
#endif
}

void
make_prefix(struct rainfo *rai, int ifindex, struct in6_addr *addr, int plen)
{
        struct in6_prefixreq ipr;

        memset(&ipr, 0, sizeof(ipr));
        if (if_indextoname(ifindex, ipr.ipr_name) == NULL) {
                syslog(LOG_ERR, "<%s> Prefix added interface No.%d doesn't"
                       "exist. This should not happen! %s", __func__,
                       ifindex, strerror(errno));
                exit(1);
        }
        ipr.ipr_prefix.sin6_len = sizeof(ipr.ipr_prefix);
        ipr.ipr_prefix.sin6_family = AF_INET6;
        ipr.ipr_prefix.sin6_addr = *addr;
        ipr.ipr_plen = plen;

        if (init_prefix(&ipr))
                return; /* init failed by some error */
        add_prefix(rai, &ipr);
}

void
make_packet(struct rainfo *rainfo)
{
        size_t packlen, lladdroptlen = 0;
        char *buf;
        struct nd_router_advert *ra;
        struct nd_opt_prefix_info *ndopt_pi;
        struct nd_opt_mtu *ndopt_mtu;
#ifdef MIP6
        struct nd_opt_advinterval *ndopt_advint;
        struct nd_opt_homeagent_info *ndopt_hai;
#endif
        struct nd_opt_route_info *ndopt_rti;
        struct prefix *pfx;
        struct rtinfo *rti;

        /* calculate total length */
        packlen = sizeof(struct nd_router_advert);
        if (rainfo->advlinkopt) {
                if ((lladdroptlen = lladdropt_length(rainfo->sdl)) == 0) {
                        syslog(LOG_INFO,
                               "<%s> link-layer address option has"
                               " null length on %s."
                               " Treat as not included.",
                               __func__, rainfo->ifname);
                        rainfo->advlinkopt = 0;
                }
                packlen += lladdroptlen;
        }
        if (rainfo->pfxs)
                packlen += sizeof(struct nd_opt_prefix_info) * rainfo->pfxs;
        if (rainfo->linkmtu)
                packlen += sizeof(struct nd_opt_mtu);
#ifdef MIP6
        if (mobileip6 && rainfo->maxinterval)
                packlen += sizeof(struct nd_opt_advinterval);
        if (mobileip6 && rainfo->hatime)
                packlen += sizeof(struct nd_opt_homeagent_info);
#endif
#ifdef ND_OPT_ROUTE_INFO
        for (rti = rainfo->route.next; rti != &rainfo->route; rti = rti->next)
                packlen += sizeof(struct nd_opt_route_info) + 
                           ((rti->prefixlen + 0x3f) >> 6) * 8;
#endif

        /* allocate memory for the packet */
        if ((buf = malloc(packlen)) == NULL) {
                syslog(LOG_ERR,
                       "<%s> can't get enough memory for an RA packet",
                       __func__);
                exit(1);
        }
        if (rainfo->ra_data) {
                /* free the previous packet */
                free(rainfo->ra_data);
                rainfo->ra_data = NULL;
        }
        rainfo->ra_data = buf;
        /* XXX: what if packlen > 576? */
        rainfo->ra_datalen = packlen;

        /*
         * construct the packet
         */
        ra = (struct nd_router_advert *)buf;
        ra->nd_ra_type = ND_ROUTER_ADVERT;
        ra->nd_ra_code = 0;
        ra->nd_ra_cksum = 0;
        ra->nd_ra_curhoplimit = (u_int8_t)(0xff & rainfo->hoplimit);
        ra->nd_ra_flags_reserved = 0; /* just in case */
        /*
         * XXX: the router preference field, which is a 2-bit field, should be
         * initialized before other fields.
         */
        ra->nd_ra_flags_reserved = 0xff & rainfo->rtpref;
        ra->nd_ra_flags_reserved |=
                rainfo->managedflg ? ND_RA_FLAG_MANAGED : 0;
        ra->nd_ra_flags_reserved |=
                rainfo->otherflg ? ND_RA_FLAG_OTHER : 0;
#ifdef MIP6
        ra->nd_ra_flags_reserved |=
                rainfo->haflg ? ND_RA_FLAG_HA : 0;
#endif
        ra->nd_ra_router_lifetime = htons(rainfo->lifetime);
        ra->nd_ra_reachable = htonl(rainfo->reachabletime);
        ra->nd_ra_retransmit = htonl(rainfo->retranstimer);
        buf += sizeof(*ra);

        if (rainfo->advlinkopt) {
                lladdropt_fill(rainfo->sdl, (struct nd_opt_hdr *)buf);
                buf += lladdroptlen;
        }

        if (rainfo->linkmtu) {
                ndopt_mtu = (struct nd_opt_mtu *)buf;
                ndopt_mtu->nd_opt_mtu_type = ND_OPT_MTU;
                ndopt_mtu->nd_opt_mtu_len = 1;
                ndopt_mtu->nd_opt_mtu_reserved = 0;
                ndopt_mtu->nd_opt_mtu_mtu = htonl(rainfo->linkmtu);
                buf += sizeof(struct nd_opt_mtu);
        }

#ifdef MIP6
        if (mobileip6 && rainfo->maxinterval) {
                ndopt_advint = (struct nd_opt_advinterval *)buf;
                ndopt_advint->nd_opt_adv_type = ND_OPT_ADVINTERVAL;
                ndopt_advint->nd_opt_adv_len = 1;
                ndopt_advint->nd_opt_adv_reserved = 0;
                ndopt_advint->nd_opt_adv_interval = htonl(rainfo->maxinterval *
                                                          1000);
                buf += sizeof(struct nd_opt_advinterval);
        }
#endif
        
#ifdef MIP6
        if (rainfo->hatime) {
                ndopt_hai = (struct nd_opt_homeagent_info *)buf;
                ndopt_hai->nd_opt_hai_type = ND_OPT_HOMEAGENT_INFO;
                ndopt_hai->nd_opt_hai_len = 1;
                ndopt_hai->nd_opt_hai_reserved = 0;
                ndopt_hai->nd_opt_hai_preference = htons(rainfo->hapref);
                ndopt_hai->nd_opt_hai_lifetime = htons(rainfo->hatime);
                buf += sizeof(struct nd_opt_homeagent_info);
        }
#endif
        
        for (pfx = rainfo->prefix.next;
             pfx != &rainfo->prefix; pfx = pfx->next) {
                u_int32_t vltime, pltime;
                struct timeval now;

                ndopt_pi = (struct nd_opt_prefix_info *)buf;
                ndopt_pi->nd_opt_pi_type = ND_OPT_PREFIX_INFORMATION;
                ndopt_pi->nd_opt_pi_len = 4;
                ndopt_pi->nd_opt_pi_prefix_len = pfx->prefixlen;
                ndopt_pi->nd_opt_pi_flags_reserved = 0;
                if (pfx->onlinkflg)
                        ndopt_pi->nd_opt_pi_flags_reserved |=
                                ND_OPT_PI_FLAG_ONLINK;
                if (pfx->autoconfflg)
                        ndopt_pi->nd_opt_pi_flags_reserved |=
                                ND_OPT_PI_FLAG_AUTO;
#ifdef MIP6
                if (pfx->routeraddr)
                        ndopt_pi->nd_opt_pi_flags_reserved |=
                                ND_OPT_PI_FLAG_ROUTER;
#endif
                if (pfx->timer)
                        vltime = 0;
                else {
                        if (pfx->vltimeexpire || pfx->pltimeexpire)
                                gettimeofday(&now, NULL);
                        if (pfx->vltimeexpire == 0)
                                vltime = pfx->validlifetime;
                        else
                                vltime = (pfx->vltimeexpire > now.tv_sec) ?
                                    pfx->vltimeexpire - now.tv_sec : 0;
                }
                if (pfx->timer)
                        pltime = 0;
                else {
                        if (pfx->pltimeexpire == 0)
                                pltime = pfx->preflifetime;
                        else
                                pltime = (pfx->pltimeexpire > now.tv_sec) ? 
                                    pfx->pltimeexpire - now.tv_sec : 0;
                }
                if (vltime < pltime) {
                        /*
                         * this can happen if vltime is decrement but pltime
                         * is not.
                         */
                        pltime = vltime;
                }
                ndopt_pi->nd_opt_pi_valid_time = htonl(vltime);
                ndopt_pi->nd_opt_pi_preferred_time = htonl(pltime);
                ndopt_pi->nd_opt_pi_reserved2 = 0;
                ndopt_pi->nd_opt_pi_prefix = pfx->prefix;

                buf += sizeof(struct nd_opt_prefix_info);
        }

#ifdef ND_OPT_ROUTE_INFO
        for (rti = rainfo->route.next; rti != &rainfo->route; rti = rti->next) {
                u_int8_t psize = (rti->prefixlen + 0x3f) >> 6;

                ndopt_rti = (struct nd_opt_route_info *)buf;
                ndopt_rti->nd_opt_rti_type = ND_OPT_ROUTE_INFO;
                ndopt_rti->nd_opt_rti_len = 1 + psize;
                ndopt_rti->nd_opt_rti_prefixlen = rti->prefixlen;
                ndopt_rti->nd_opt_rti_flags = 0xff & rti->rtpref;
                ndopt_rti->nd_opt_rti_lifetime = htonl(rti->ltime);
                memcpy(ndopt_rti + 1, &rti->prefix, psize * 8);
                buf += sizeof(struct nd_opt_route_info) + psize * 8;
        }
#endif

        return;
}

static int
getinet6sysctl(int code)
{
        int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, 0 };
        int value;
        size_t size;

        mib[3] = code;
        size = sizeof(value);
        if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), &value, &size, NULL, 0)
            < 0) {
                syslog(LOG_ERR, "<%s>: failed to get ip6 sysctl(%d): %s",
                       __func__, code,
                       strerror(errno));
                return(-1);
        }
        else
                return(value);
}