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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/nd6_rtr.c

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    1 /*-
    2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. Neither the name of the project nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      $KAME: nd6_rtr.c,v 1.111 2001/04/27 01:37:15 jinmei Exp $
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD$");
   34 
   35 #include "opt_inet.h"
   36 #include "opt_inet6.h"
   37 
   38 #include <sys/param.h>
   39 #include <sys/systm.h>
   40 #include <sys/malloc.h>
   41 #include <sys/mbuf.h>
   42 #include <sys/socket.h>
   43 #include <sys/sockio.h>
   44 #include <sys/time.h>
   45 #include <sys/kernel.h>
   46 #include <sys/errno.h>
   47 #include <sys/syslog.h>
   48 #include <sys/queue.h>
   49 
   50 #include <net/if.h>
   51 #include <net/if_types.h>
   52 #include <net/if_dl.h>
   53 #include <net/route.h>
   54 #include <net/radix.h>
   55 
   56 #include <netinet/in.h>
   57 #include <netinet6/in6_var.h>
   58 #include <netinet6/in6_ifattach.h>
   59 #include <netinet/ip6.h>
   60 #include <netinet6/ip6_var.h>
   61 #include <netinet6/nd6.h>
   62 #include <netinet/icmp6.h>
   63 #include <netinet6/scope6_var.h>
   64 
   65 #include <net/net_osdep.h>
   66 
   67 #define SDL(s)  ((struct sockaddr_dl *)s)
   68 
   69 static int rtpref(struct nd_defrouter *);
   70 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
   71 static int prelist_update __P((struct nd_prefixctl *, struct nd_defrouter *,
   72     struct mbuf *, int));
   73 static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *,      int);
   74 static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *,
   75         struct nd_defrouter *));
   76 static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
   77 static void pfxrtr_del(struct nd_pfxrouter *);
   78 static struct nd_pfxrouter *find_pfxlist_reachable_router
   79 (struct nd_prefix *);
   80 static void defrouter_delreq(struct nd_defrouter *);
   81 static void nd6_rtmsg(int, struct rtentry *);
   82 
   83 static int in6_init_prefix_ltimes(struct nd_prefix *);
   84 static void in6_init_address_ltimes __P((struct nd_prefix *,
   85         struct in6_addrlifetime *));
   86 
   87 static int rt6_deleteroute(struct radix_node *, void *);
   88 
   89 extern int nd6_recalc_reachtm_interval;
   90 
   91 static struct ifnet *nd6_defifp;
   92 int nd6_defifindex;
   93 
   94 int ip6_use_tempaddr = 0;
   95 
   96 int ip6_desync_factor;
   97 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
   98 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
   99 /*
  100  * shorter lifetimes for debugging purposes.
  101 int ip6_temp_preferred_lifetime = 800;
  102 static int ip6_temp_valid_lifetime = 1800;
  103 */
  104 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
  105 
  106 /* RTPREF_MEDIUM has to be 0! */
  107 #define RTPREF_HIGH     1
  108 #define RTPREF_MEDIUM   0
  109 #define RTPREF_LOW      (-1)
  110 #define RTPREF_RESERVED (-2)
  111 #define RTPREF_INVALID  (-3)    /* internal */
  112 
  113 /*
  114  * Receive Router Solicitation Message - just for routers.
  115  * Router solicitation/advertisement is mostly managed by userland program
  116  * (rtadvd) so here we have no function like nd6_ra_output().
  117  *
  118  * Based on RFC 2461
  119  */
  120 void
  121 nd6_rs_input(m, off, icmp6len)
  122         struct  mbuf *m;
  123         int off, icmp6len;
  124 {
  125         struct ifnet *ifp = m->m_pkthdr.rcvif;
  126         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  127         struct nd_router_solicit *nd_rs;
  128         struct in6_addr saddr6 = ip6->ip6_src;
  129         char *lladdr = NULL;
  130         int lladdrlen = 0;
  131         union nd_opts ndopts;
  132 
  133         /* If I'm not a router, ignore it. */
  134         if (ip6_accept_rtadv != 0 || ip6_forwarding != 1)
  135                 goto freeit;
  136 
  137         /* Sanity checks */
  138         if (ip6->ip6_hlim != 255) {
  139                 nd6log((LOG_ERR,
  140                     "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
  141                     ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
  142                     ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
  143                 goto bad;
  144         }
  145 
  146         /*
  147          * Don't update the neighbor cache, if src = ::.
  148          * This indicates that the src has no IP address assigned yet.
  149          */
  150         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
  151                 goto freeit;
  152 
  153 #ifndef PULLDOWN_TEST
  154         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  155         nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
  156 #else
  157         IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
  158         if (nd_rs == NULL) {
  159                 icmp6stat.icp6s_tooshort++;
  160                 return;
  161         }
  162 #endif
  163 
  164         icmp6len -= sizeof(*nd_rs);
  165         nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
  166         if (nd6_options(&ndopts) < 0) {
  167                 nd6log((LOG_INFO,
  168                     "nd6_rs_input: invalid ND option, ignored\n"));
  169                 /* nd6_options have incremented stats */
  170                 goto freeit;
  171         }
  172 
  173         if (ndopts.nd_opts_src_lladdr) {
  174                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  175                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  176         }
  177 
  178         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  179                 nd6log((LOG_INFO,
  180                     "nd6_rs_input: lladdrlen mismatch for %s "
  181                     "(if %d, RS packet %d)\n",
  182                     ip6_sprintf(&saddr6),
  183                     ifp->if_addrlen, lladdrlen - 2));
  184                 goto bad;
  185         }
  186 
  187         nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
  188 
  189  freeit:
  190         m_freem(m);
  191         return;
  192 
  193  bad:
  194         icmp6stat.icp6s_badrs++;
  195         m_freem(m);
  196 }
  197 
  198 /*
  199  * Receive Router Advertisement Message.
  200  *
  201  * Based on RFC 2461
  202  * TODO: on-link bit on prefix information
  203  * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
  204  */
  205 void
  206 nd6_ra_input(m, off, icmp6len)
  207         struct  mbuf *m;
  208         int off, icmp6len;
  209 {
  210         struct ifnet *ifp = m->m_pkthdr.rcvif;
  211         struct nd_ifinfo *ndi = ND_IFINFO(ifp);
  212         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  213         struct nd_router_advert *nd_ra;
  214         struct in6_addr saddr6 = ip6->ip6_src;
  215         int mcast = 0;
  216         union nd_opts ndopts;
  217         struct nd_defrouter *dr;
  218 
  219         /*
  220          * We only accept RAs only when
  221          * the system-wide variable allows the acceptance, and
  222          * per-interface variable allows RAs on the receiving interface.
  223          */
  224         if (ip6_accept_rtadv == 0)
  225                 goto freeit;
  226         if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
  227                 goto freeit;
  228 
  229         if (ip6->ip6_hlim != 255) {
  230                 nd6log((LOG_ERR,
  231                     "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
  232                     ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
  233                     ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
  234                 goto bad;
  235         }
  236 
  237         if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
  238                 nd6log((LOG_ERR,
  239                     "nd6_ra_input: src %s is not link-local\n",
  240                     ip6_sprintf(&saddr6)));
  241                 goto bad;
  242         }
  243 
  244 #ifndef PULLDOWN_TEST
  245         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  246         nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
  247 #else
  248         IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
  249         if (nd_ra == NULL) {
  250                 icmp6stat.icp6s_tooshort++;
  251                 return;
  252         }
  253 #endif
  254 
  255         icmp6len -= sizeof(*nd_ra);
  256         nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
  257         if (nd6_options(&ndopts) < 0) {
  258                 nd6log((LOG_INFO,
  259                     "nd6_ra_input: invalid ND option, ignored\n"));
  260                 /* nd6_options have incremented stats */
  261                 goto freeit;
  262         }
  263 
  264     {
  265         struct nd_defrouter dr0;
  266         u_int32_t advreachable = nd_ra->nd_ra_reachable;
  267 
  268         /* remember if this is a multicasted advertisement */
  269         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
  270                 mcast = 1;
  271 
  272         bzero(&dr0, sizeof(dr0));
  273         dr0.rtaddr = saddr6;
  274         dr0.flags  = nd_ra->nd_ra_flags_reserved;
  275         dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
  276         dr0.expire = time_second + dr0.rtlifetime;
  277         dr0.ifp = ifp;
  278         /* unspecified or not? (RFC 2461 6.3.4) */
  279         if (advreachable) {
  280                 advreachable = ntohl(advreachable);
  281                 if (advreachable <= MAX_REACHABLE_TIME &&
  282                     ndi->basereachable != advreachable) {
  283                         ndi->basereachable = advreachable;
  284                         ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
  285                         ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
  286                 }
  287         }
  288         if (nd_ra->nd_ra_retransmit)
  289                 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
  290         if (nd_ra->nd_ra_curhoplimit)
  291                 ndi->chlim = nd_ra->nd_ra_curhoplimit;
  292         dr = defrtrlist_update(&dr0);
  293     }
  294 
  295         /*
  296          * prefix
  297          */
  298         if (ndopts.nd_opts_pi) {
  299                 struct nd_opt_hdr *pt;
  300                 struct nd_opt_prefix_info *pi = NULL;
  301                 struct nd_prefixctl pr;
  302 
  303                 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
  304                      pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
  305                      pt = (struct nd_opt_hdr *)((caddr_t)pt +
  306                                                 (pt->nd_opt_len << 3))) {
  307                         if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
  308                                 continue;
  309                         pi = (struct nd_opt_prefix_info *)pt;
  310 
  311                         if (pi->nd_opt_pi_len != 4) {
  312                                 nd6log((LOG_INFO,
  313                                     "nd6_ra_input: invalid option "
  314                                     "len %d for prefix information option, "
  315                                     "ignored\n", pi->nd_opt_pi_len));
  316                                 continue;
  317                         }
  318 
  319                         if (128 < pi->nd_opt_pi_prefix_len) {
  320                                 nd6log((LOG_INFO,
  321                                     "nd6_ra_input: invalid prefix "
  322                                     "len %d for prefix information option, "
  323                                     "ignored\n", pi->nd_opt_pi_prefix_len));
  324                                 continue;
  325                         }
  326 
  327                         if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
  328                          || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
  329                                 nd6log((LOG_INFO,
  330                                     "nd6_ra_input: invalid prefix "
  331                                     "%s, ignored\n",
  332                                     ip6_sprintf(&pi->nd_opt_pi_prefix)));
  333                                 continue;
  334                         }
  335 
  336                         bzero(&pr, sizeof(pr));
  337                         pr.ndpr_prefix.sin6_family = AF_INET6;
  338                         pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
  339                         pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
  340                         pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
  341 
  342                         pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
  343                             ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
  344                         pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
  345                             ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
  346                         pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
  347                         pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
  348                         pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
  349                         (void)prelist_update(&pr, dr, m, mcast);
  350                 }
  351         }
  352 
  353         /*
  354          * MTU
  355          */
  356         if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
  357                 u_long mtu;
  358                 u_long maxmtu;
  359 
  360                 mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
  361 
  362                 /* lower bound */
  363                 if (mtu < IPV6_MMTU) {
  364                         nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
  365                             "mtu=%lu sent from %s, ignoring\n",
  366                             mtu, ip6_sprintf(&ip6->ip6_src)));
  367                         goto skip;
  368                 }
  369 
  370                 /* upper bound */
  371                 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
  372                     ? ndi->maxmtu : ifp->if_mtu;
  373                 if (mtu <= maxmtu) {
  374                         int change = (ndi->linkmtu != mtu);
  375 
  376                         ndi->linkmtu = mtu;
  377                         if (change) /* in6_maxmtu may change */
  378                                 in6_setmaxmtu();
  379                 } else {
  380                         nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
  381                             "mtu=%lu sent from %s; "
  382                             "exceeds maxmtu %lu, ignoring\n",
  383                             mtu, ip6_sprintf(&ip6->ip6_src), maxmtu));
  384                 }
  385         }
  386 
  387  skip:
  388 
  389         /*
  390          * Source link layer address
  391          */
  392     {
  393         char *lladdr = NULL;
  394         int lladdrlen = 0;
  395 
  396         if (ndopts.nd_opts_src_lladdr) {
  397                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  398                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  399         }
  400 
  401         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  402                 nd6log((LOG_INFO,
  403                     "nd6_ra_input: lladdrlen mismatch for %s "
  404                     "(if %d, RA packet %d)\n", ip6_sprintf(&saddr6),
  405                     ifp->if_addrlen, lladdrlen - 2));
  406                 goto bad;
  407         }
  408 
  409         nd6_cache_lladdr(ifp, &saddr6, lladdr,
  410             lladdrlen, ND_ROUTER_ADVERT, 0);
  411 
  412         /*
  413          * Installing a link-layer address might change the state of the
  414          * router's neighbor cache, which might also affect our on-link
  415          * detection of adveritsed prefixes.
  416          */
  417         pfxlist_onlink_check();
  418     }
  419 
  420  freeit:
  421         m_freem(m);
  422         return;
  423 
  424  bad:
  425         icmp6stat.icp6s_badra++;
  426         m_freem(m);
  427 }
  428 
  429 /*
  430  * default router list proccessing sub routines
  431  */
  432 
  433 /* tell the change to user processes watching the routing socket. */
  434 static void
  435 nd6_rtmsg(cmd, rt)
  436         int cmd;
  437         struct rtentry *rt;
  438 {
  439         struct rt_addrinfo info;
  440 
  441         bzero((caddr_t)&info, sizeof(info));
  442         info.rti_info[RTAX_DST] = rt_key(rt);
  443         info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
  444         info.rti_info[RTAX_NETMASK] = rt_mask(rt);
  445         if (rt->rt_ifp) {
  446                 info.rti_info[RTAX_IFP] =
  447                     TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr;
  448                 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
  449         }
  450 
  451         rt_missmsg(cmd, &info, rt->rt_flags, 0);
  452 }
  453 
  454 void
  455 defrouter_addreq(new)
  456         struct nd_defrouter *new;
  457 {
  458         struct sockaddr_in6 def, mask, gate;
  459         struct rtentry *newrt = NULL;
  460         int s;
  461         int error;
  462 
  463         bzero(&def, sizeof(def));
  464         bzero(&mask, sizeof(mask));
  465         bzero(&gate, sizeof(gate));
  466 
  467         def.sin6_len = mask.sin6_len = gate.sin6_len =
  468             sizeof(struct sockaddr_in6);
  469         def.sin6_family = gate.sin6_family = AF_INET6;
  470         gate.sin6_addr = new->rtaddr;
  471 
  472         s = splnet();
  473         error = rtrequest(RTM_ADD, (struct sockaddr *)&def,
  474             (struct sockaddr *)&gate, (struct sockaddr *)&mask,
  475             RTF_GATEWAY, &newrt);
  476         if (newrt) {
  477                 RT_LOCK(newrt);
  478                 nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
  479                 RT_REMREF(newrt);
  480                 RT_UNLOCK(newrt);
  481         }
  482         if (error == 0)
  483                 new->installed = 1;
  484         splx(s);
  485         return;
  486 }
  487 
  488 struct nd_defrouter *
  489 defrouter_lookup(addr, ifp)
  490         struct in6_addr *addr;
  491         struct ifnet *ifp;
  492 {
  493         struct nd_defrouter *dr;
  494 
  495         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  496              dr = TAILQ_NEXT(dr, dr_entry)) {
  497                 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
  498                         return (dr);
  499         }
  500 
  501         return (NULL);          /* search failed */
  502 }
  503 
  504 /*
  505  * Remove the default route for a given router.
  506  * This is just a subroutine function for defrouter_select(), and should
  507  * not be called from anywhere else.
  508  */
  509 static void
  510 defrouter_delreq(dr)
  511         struct nd_defrouter *dr;
  512 {
  513         struct sockaddr_in6 def, mask, gate;
  514         struct rtentry *oldrt = NULL;
  515 
  516         bzero(&def, sizeof(def));
  517         bzero(&mask, sizeof(mask));
  518         bzero(&gate, sizeof(gate));
  519 
  520         def.sin6_len = mask.sin6_len = gate.sin6_len =
  521             sizeof(struct sockaddr_in6);
  522         def.sin6_family = gate.sin6_family = AF_INET6;
  523         gate.sin6_addr = dr->rtaddr;
  524 
  525         rtrequest(RTM_DELETE, (struct sockaddr *)&def,
  526             (struct sockaddr *)&gate,
  527             (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt);
  528         if (oldrt) {
  529                 nd6_rtmsg(RTM_DELETE, oldrt);
  530                 RTFREE(oldrt);
  531         }
  532 
  533         dr->installed = 0;
  534 }
  535 
  536 /*
  537  * remove all default routes from default router list
  538  */
  539 void
  540 defrouter_reset()
  541 {
  542         struct nd_defrouter *dr;
  543 
  544         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  545              dr = TAILQ_NEXT(dr, dr_entry))
  546                 defrouter_delreq(dr);
  547 
  548         /*
  549          * XXX should we also nuke any default routers in the kernel, by
  550          * going through them by rtalloc1()?
  551          */
  552 }
  553 
  554 void
  555 defrtrlist_del(dr)
  556         struct nd_defrouter *dr;
  557 {
  558         struct nd_defrouter *deldr = NULL;
  559         struct nd_prefix *pr;
  560 
  561         /*
  562          * Flush all the routing table entries that use the router
  563          * as a next hop.
  564          */
  565         if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */
  566                 rt6_flush(&dr->rtaddr, dr->ifp);
  567 
  568         if (dr->installed) {
  569                 deldr = dr;
  570                 defrouter_delreq(dr);
  571         }
  572         TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
  573 
  574         /*
  575          * Also delete all the pointers to the router in each prefix lists.
  576          */
  577         for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
  578                 struct nd_pfxrouter *pfxrtr;
  579                 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
  580                         pfxrtr_del(pfxrtr);
  581         }
  582         pfxlist_onlink_check();
  583 
  584         /*
  585          * If the router is the primary one, choose a new one.
  586          * Note that defrouter_select() will remove the current gateway
  587          * from the routing table.
  588          */
  589         if (deldr)
  590                 defrouter_select();
  591 
  592         free(dr, M_IP6NDP);
  593 }
  594 
  595 /*
  596  * Default Router Selection according to Section 6.3.6 of RFC 2461 and
  597  * draft-ietf-ipngwg-router-selection:
  598  * 1) Routers that are reachable or probably reachable should be preferred.
  599  *    If we have more than one (probably) reachable router, prefer ones
  600  *    with the highest router preference.
  601  * 2) When no routers on the list are known to be reachable or
  602  *    probably reachable, routers SHOULD be selected in a round-robin
  603  *    fashion, regardless of router preference values.
  604  * 3) If the Default Router List is empty, assume that all
  605  *    destinations are on-link.
  606  *
  607  * We assume nd_defrouter is sorted by router preference value.
  608  * Since the code below covers both with and without router preference cases,
  609  * we do not need to classify the cases by ifdef.
  610  *
  611  * At this moment, we do not try to install more than one default router,
  612  * even when the multipath routing is available, because we're not sure about
  613  * the benefits for stub hosts comparing to the risk of making the code
  614  * complicated and the possibility of introducing bugs.
  615  */
  616 void
  617 defrouter_select()
  618 {
  619         int s = splnet();
  620         struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL;
  621         struct rtentry *rt = NULL;
  622         struct llinfo_nd6 *ln = NULL;
  623 
  624         /*
  625          * This function should be called only when acting as an autoconfigured
  626          * host.  Although the remaining part of this function is not effective
  627          * if the node is not an autoconfigured host, we explicitly exclude
  628          * such cases here for safety.
  629          */
  630         if (ip6_forwarding || !ip6_accept_rtadv) {
  631                 nd6log((LOG_WARNING,
  632                     "defrouter_select: called unexpectedly (forwarding=%d, "
  633                     "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv));
  634                 splx(s);
  635                 return;
  636         }
  637 
  638         /*
  639          * Let's handle easy case (3) first:
  640          * If default router list is empty, there's nothing to be done.
  641          */
  642         if (!TAILQ_FIRST(&nd_defrouter)) {
  643                 splx(s);
  644                 return;
  645         }
  646 
  647         /*
  648          * Search for a (probably) reachable router from the list.
  649          * We just pick up the first reachable one (if any), assuming that
  650          * the ordering rule of the list described in defrtrlist_update().
  651          */
  652         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  653              dr = TAILQ_NEXT(dr, dr_entry)) {
  654                 if (selected_dr == NULL &&
  655                     (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
  656                     (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
  657                     ND6_IS_LLINFO_PROBREACH(ln)) {
  658                         selected_dr = dr;
  659                 }
  660 
  661                 if (dr->installed && installed_dr == NULL)
  662                         installed_dr = dr;
  663                 else if (dr->installed && installed_dr) {
  664                         /* this should not happen.  warn for diagnosis. */
  665                         log(LOG_ERR, "defrouter_select: more than one router"
  666                             " is installed\n");
  667                 }
  668         }
  669         /*
  670          * If none of the default routers was found to be reachable,
  671          * round-robin the list regardless of preference.
  672          * Otherwise, if we have an installed router, check if the selected
  673          * (reachable) router should really be preferred to the installed one.
  674          * We only prefer the new router when the old one is not reachable
  675          * or when the new one has a really higher preference value.
  676          */
  677         if (selected_dr == NULL) {
  678                 if (installed_dr == NULL || !TAILQ_NEXT(installed_dr, dr_entry))
  679                         selected_dr = TAILQ_FIRST(&nd_defrouter);
  680                 else
  681                         selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
  682         } else if (installed_dr &&
  683             (rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
  684             (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
  685             ND6_IS_LLINFO_PROBREACH(ln) &&
  686             rtpref(selected_dr) <= rtpref(installed_dr)) {
  687                 selected_dr = installed_dr;
  688         }
  689 
  690         /*
  691          * If the selected router is different than the installed one,
  692          * remove the installed router and install the selected one.
  693          * Note that the selected router is never NULL here.
  694          */
  695         if (installed_dr != selected_dr) {
  696                 if (installed_dr)
  697                         defrouter_delreq(installed_dr);
  698                 defrouter_addreq(selected_dr);
  699         }
  700 
  701         splx(s);
  702         return;
  703 }
  704 
  705 /*
  706  * for default router selection
  707  * regards router-preference field as a 2-bit signed integer
  708  */
  709 static int
  710 rtpref(struct nd_defrouter *dr)
  711 {
  712         switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) {
  713         case ND_RA_FLAG_RTPREF_HIGH:
  714                 return (RTPREF_HIGH);
  715         case ND_RA_FLAG_RTPREF_MEDIUM:
  716         case ND_RA_FLAG_RTPREF_RSV:
  717                 return (RTPREF_MEDIUM);
  718         case ND_RA_FLAG_RTPREF_LOW:
  719                 return (RTPREF_LOW);
  720         default:
  721                 /*
  722                  * This case should never happen.  If it did, it would mean a
  723                  * serious bug of kernel internal.  We thus always bark here.
  724                  * Or, can we even panic?
  725                  */
  726                 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags);
  727                 return (RTPREF_INVALID);
  728         }
  729         /* NOTREACHED */
  730 }
  731 
  732 static struct nd_defrouter *
  733 defrtrlist_update(new)
  734         struct nd_defrouter *new;
  735 {
  736         struct nd_defrouter *dr, *n;
  737         int s = splnet();
  738 
  739         if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
  740                 /* entry exists */
  741                 if (new->rtlifetime == 0) {
  742                         defrtrlist_del(dr);
  743                         dr = NULL;
  744                 } else {
  745                         int oldpref = rtpref(dr);
  746 
  747                         /* override */
  748                         dr->flags = new->flags; /* xxx flag check */
  749                         dr->rtlifetime = new->rtlifetime;
  750                         dr->expire = new->expire;
  751 
  752                         /*
  753                          * If the preference does not change, there's no need
  754                          * to sort the entries.
  755                          */
  756                         if (rtpref(new) == oldpref) {
  757                                 splx(s);
  758                                 return (dr);
  759                         }
  760 
  761                         /*
  762                          * preferred router may be changed, so relocate
  763                          * this router.
  764                          * XXX: calling TAILQ_REMOVE directly is a bad manner.
  765                          * However, since defrtrlist_del() has many side
  766                          * effects, we intentionally do so here.
  767                          * defrouter_select() below will handle routing
  768                          * changes later.
  769                          */
  770                         TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
  771                         n = dr;
  772                         goto insert;
  773                 }
  774                 splx(s);
  775                 return (dr);
  776         }
  777 
  778         /* entry does not exist */
  779         if (new->rtlifetime == 0) {
  780                 splx(s);
  781                 return (NULL);
  782         }
  783 
  784         n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
  785         if (n == NULL) {
  786                 splx(s);
  787                 return (NULL);
  788         }
  789         bzero(n, sizeof(*n));
  790         *n = *new;
  791 
  792 insert:
  793         /*
  794          * Insert the new router in the Default Router List;
  795          * The Default Router List should be in the descending order
  796          * of router-preferece.  Routers with the same preference are
  797          * sorted in the arriving time order.
  798          */
  799 
  800         /* insert at the end of the group */
  801         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  802              dr = TAILQ_NEXT(dr, dr_entry)) {
  803                 if (rtpref(n) > rtpref(dr))
  804                         break;
  805         }
  806         if (dr)
  807                 TAILQ_INSERT_BEFORE(dr, n, dr_entry);
  808         else
  809                 TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
  810 
  811         defrouter_select();
  812 
  813         splx(s);
  814 
  815         return (n);
  816 }
  817 
  818 static struct nd_pfxrouter *
  819 pfxrtr_lookup(pr, dr)
  820         struct nd_prefix *pr;
  821         struct nd_defrouter *dr;
  822 {
  823         struct nd_pfxrouter *search;
  824 
  825         for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
  826                 if (search->router == dr)
  827                         break;
  828         }
  829 
  830         return (search);
  831 }
  832 
  833 static void
  834 pfxrtr_add(pr, dr)
  835         struct nd_prefix *pr;
  836         struct nd_defrouter *dr;
  837 {
  838         struct nd_pfxrouter *new;
  839 
  840         new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
  841         if (new == NULL)
  842                 return;
  843         bzero(new, sizeof(*new));
  844         new->router = dr;
  845 
  846         LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
  847 
  848         pfxlist_onlink_check();
  849 }
  850 
  851 static void
  852 pfxrtr_del(pfr)
  853         struct nd_pfxrouter *pfr;
  854 {
  855         LIST_REMOVE(pfr, pfr_entry);
  856         free(pfr, M_IP6NDP);
  857 }
  858 
  859 struct nd_prefix *
  860 nd6_prefix_lookup(key)
  861         struct nd_prefixctl *key;
  862 {
  863         struct nd_prefix *search;
  864 
  865         for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
  866                 if (key->ndpr_ifp == search->ndpr_ifp &&
  867                     key->ndpr_plen == search->ndpr_plen &&
  868                     in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
  869                     &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
  870                         break;
  871                 }
  872         }
  873 
  874         return (search);
  875 }
  876 
  877 int
  878 nd6_prelist_add(pr, dr, newp)
  879         struct nd_prefixctl *pr;
  880         struct nd_prefix **newp;
  881         struct nd_defrouter *dr;
  882 {
  883         struct nd_prefix *new = NULL;
  884         int error = 0;
  885         int i, s;
  886 
  887         new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
  888         if (new == NULL)
  889                 return(ENOMEM);
  890         bzero(new, sizeof(*new));
  891         new->ndpr_ifp = pr->ndpr_ifp;
  892         new->ndpr_prefix = pr->ndpr_prefix;
  893         new->ndpr_plen = pr->ndpr_plen;
  894         new->ndpr_vltime = pr->ndpr_vltime;
  895         new->ndpr_pltime = pr->ndpr_pltime;
  896         new->ndpr_flags = pr->ndpr_flags;
  897         if ((error = in6_init_prefix_ltimes(new)) != 0) {
  898                 free(new, M_IP6NDP);
  899                 return(error);
  900         }
  901         new->ndpr_lastupdate = time_second;
  902         if (newp != NULL)
  903                 *newp = new;
  904 
  905         /* initialization */
  906         LIST_INIT(&new->ndpr_advrtrs);
  907         in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
  908         /* make prefix in the canonical form */
  909         for (i = 0; i < 4; i++)
  910                 new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
  911                     new->ndpr_mask.s6_addr32[i];
  912 
  913         s = splnet();
  914         /* link ndpr_entry to nd_prefix list */
  915         LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
  916         splx(s);
  917 
  918         /* ND_OPT_PI_FLAG_ONLINK processing */
  919         if (new->ndpr_raf_onlink) {
  920                 int e;
  921 
  922                 if ((e = nd6_prefix_onlink(new)) != 0) {
  923                         nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
  924                             "the prefix %s/%d on-link on %s (errno=%d)\n",
  925                             ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
  926                             pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
  927                         /* proceed anyway. XXX: is it correct? */
  928                 }
  929         }
  930 
  931         if (dr)
  932                 pfxrtr_add(new, dr);
  933 
  934         return 0;
  935 }
  936 
  937 void
  938 prelist_remove(pr)
  939         struct nd_prefix *pr;
  940 {
  941         struct nd_pfxrouter *pfr, *next;
  942         int e, s;
  943 
  944         /* make sure to invalidate the prefix until it is really freed. */
  945         pr->ndpr_vltime = 0;
  946         pr->ndpr_pltime = 0;
  947 
  948         /*
  949          * Though these flags are now meaningless, we'd rather keep the value
  950          * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
  951          * when executing "ndp -p".
  952          */
  953 
  954         if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
  955             (e = nd6_prefix_offlink(pr)) != 0) {
  956                 nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
  957                     "on %s, errno=%d\n",
  958                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
  959                     pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
  960                 /* what should we do? */
  961         }
  962 
  963         if (pr->ndpr_refcnt > 0)
  964                 return;         /* notice here? */
  965 
  966         s = splnet();
  967 
  968         /* unlink ndpr_entry from nd_prefix list */
  969         LIST_REMOVE(pr, ndpr_entry);
  970 
  971         /* free list of routers that adversed the prefix */
  972         for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
  973                 next = pfr->pfr_next;
  974 
  975                 free(pfr, M_IP6NDP);
  976         }
  977         splx(s);
  978 
  979         free(pr, M_IP6NDP);
  980 
  981         pfxlist_onlink_check();
  982 }
  983 
  984 static int
  985 prelist_update(new, dr, m, mcast)
  986         struct nd_prefixctl *new;
  987         struct nd_defrouter *dr; /* may be NULL */
  988         struct mbuf *m;
  989         int mcast;
  990 {
  991         struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
  992         struct ifaddr *ifa;
  993         struct ifnet *ifp = new->ndpr_ifp;
  994         struct nd_prefix *pr;
  995         int s = splnet();
  996         int error = 0;
  997         int newprefix = 0;
  998         int auth;
  999         struct in6_addrlifetime lt6_tmp;
 1000 
 1001         auth = 0;
 1002         if (m) {
 1003                 /*
 1004                  * Authenticity for NA consists authentication for
 1005                  * both IP header and IP datagrams, doesn't it ?
 1006                  */
 1007 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
 1008                 auth = ((m->m_flags & M_AUTHIPHDR) &&
 1009                     (m->m_flags & M_AUTHIPDGM));
 1010 #endif
 1011         }
 1012 
 1013         if ((pr = nd6_prefix_lookup(new)) != NULL) {
 1014                 /*
 1015                  * nd6_prefix_lookup() ensures that pr and new have the same
 1016                  * prefix on a same interface.
 1017                  */
 1018 
 1019                 /*
 1020                  * Update prefix information.  Note that the on-link (L) bit
 1021                  * and the autonomous (A) bit should NOT be changed from 1
 1022                  * to 0.
 1023                  */
 1024                 if (new->ndpr_raf_onlink == 1)
 1025                         pr->ndpr_raf_onlink = 1;
 1026                 if (new->ndpr_raf_auto == 1)
 1027                         pr->ndpr_raf_auto = 1;
 1028                 if (new->ndpr_raf_onlink) {
 1029                         pr->ndpr_vltime = new->ndpr_vltime;
 1030                         pr->ndpr_pltime = new->ndpr_pltime;
 1031                         (void)in6_init_prefix_ltimes(pr); /* XXX error case? */
 1032                         pr->ndpr_lastupdate = time_second;
 1033                 }
 1034 
 1035                 if (new->ndpr_raf_onlink &&
 1036                     (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
 1037                         int e;
 1038 
 1039                         if ((e = nd6_prefix_onlink(pr)) != 0) {
 1040                                 nd6log((LOG_ERR,
 1041                                     "prelist_update: failed to make "
 1042                                     "the prefix %s/%d on-link on %s "
 1043                                     "(errno=%d)\n",
 1044                                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
 1045                                     pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
 1046                                 /* proceed anyway. XXX: is it correct? */
 1047                         }
 1048                 }
 1049 
 1050                 if (dr && pfxrtr_lookup(pr, dr) == NULL)
 1051                         pfxrtr_add(pr, dr);
 1052         } else {
 1053                 struct nd_prefix *newpr = NULL;
 1054 
 1055                 newprefix = 1;
 1056 
 1057                 if (new->ndpr_vltime == 0)
 1058                         goto end;
 1059                 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
 1060                         goto end;
 1061 
 1062                 error = nd6_prelist_add(new, dr, &newpr);
 1063                 if (error != 0 || newpr == NULL) {
 1064                         nd6log((LOG_NOTICE, "prelist_update: "
 1065                             "nd6_prelist_add failed for %s/%d on %s "
 1066                             "errno=%d, returnpr=%p\n",
 1067                             ip6_sprintf(&new->ndpr_prefix.sin6_addr),
 1068                             new->ndpr_plen, if_name(new->ndpr_ifp),
 1069                             error, newpr));
 1070                         goto end; /* we should just give up in this case. */
 1071                 }
 1072 
 1073                 /*
 1074                  * XXX: from the ND point of view, we can ignore a prefix
 1075                  * with the on-link bit being zero.  However, we need a
 1076                  * prefix structure for references from autoconfigured
 1077                  * addresses.  Thus, we explicitly make sure that the prefix
 1078                  * itself expires now.
 1079                  */
 1080                 if (newpr->ndpr_raf_onlink == 0) {
 1081                         newpr->ndpr_vltime = 0;
 1082                         newpr->ndpr_pltime = 0;
 1083                         in6_init_prefix_ltimes(newpr);
 1084                 }
 1085 
 1086                 pr = newpr;
 1087         }
 1088 
 1089         /*
 1090          * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
 1091          * Note that pr must be non NULL at this point.
 1092          */
 1093 
 1094         /* 5.5.3 (a). Ignore the prefix without the A bit set. */
 1095         if (!new->ndpr_raf_auto)
 1096                 goto end;
 1097 
 1098         /*
 1099          * 5.5.3 (b). the link-local prefix should have been ignored in
 1100          * nd6_ra_input.
 1101          */
 1102 
 1103         /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
 1104         if (new->ndpr_pltime > new->ndpr_vltime) {
 1105                 error = EINVAL; /* XXX: won't be used */
 1106                 goto end;
 1107         }
 1108 
 1109         /*
 1110          * 5.5.3 (d).  If the prefix advertised is not equal to the prefix of
 1111          * an address configured by stateless autoconfiguration already in the
 1112          * list of addresses associated with the interface, and the Valid
 1113          * Lifetime is not 0, form an address.  We first check if we have
 1114          * a matching prefix.
 1115          * Note: we apply a clarification in rfc2462bis-02 here.  We only
 1116          * consider autoconfigured addresses while RFC2462 simply said
 1117          * "address".
 1118          */
 1119         TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
 1120                 struct in6_ifaddr *ifa6;
 1121                 u_int32_t remaininglifetime;
 1122 
 1123                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1124                         continue;
 1125 
 1126                 ifa6 = (struct in6_ifaddr *)ifa;
 1127 
 1128                 /*
 1129                  * We only consider autoconfigured addresses as per rfc2462bis.
 1130                  */
 1131                 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
 1132                         continue;
 1133 
 1134                 /*
 1135                  * Spec is not clear here, but I believe we should concentrate
 1136                  * on unicast (i.e. not anycast) addresses.
 1137                  * XXX: other ia6_flags? detached or duplicated?
 1138                  */
 1139                 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
 1140                         continue;
 1141 
 1142                 /*
 1143                  * Ignore the address if it is not associated with a prefix
 1144                  * or is associated with a prefix that is different from this
 1145                  * one.  (pr is never NULL here)
 1146                  */
 1147                 if (ifa6->ia6_ndpr != pr)
 1148                         continue;
 1149 
 1150                 if (ia6_match == NULL) /* remember the first one */
 1151                         ia6_match = ifa6;
 1152 
 1153                 /*
 1154                  * An already autoconfigured address matched.  Now that we
 1155                  * are sure there is at least one matched address, we can
 1156                  * proceed to 5.5.3. (e): update the lifetimes according to the
 1157                  * "two hours" rule and the privacy extension.
 1158                  * We apply some clarifications in rfc2462bis:
 1159                  * - use remaininglifetime instead of storedlifetime as a
 1160                  *   variable name
 1161                  * - remove the dead code in the "two-hour" rule
 1162                  */
 1163 #define TWOHOUR         (120*60)
 1164                 lt6_tmp = ifa6->ia6_lifetime;
 1165 
 1166                 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
 1167                         remaininglifetime = ND6_INFINITE_LIFETIME;
 1168                 else if (time_second - ifa6->ia6_updatetime >
 1169                          lt6_tmp.ia6t_vltime) {
 1170                         /*
 1171                          * The case of "invalid" address.  We should usually
 1172                          * not see this case.
 1173                          */
 1174                         remaininglifetime = 0;
 1175                 } else
 1176                         remaininglifetime = lt6_tmp.ia6t_vltime -
 1177                             (time_second - ifa6->ia6_updatetime);
 1178 
 1179                 /* when not updating, keep the current stored lifetime. */
 1180                 lt6_tmp.ia6t_vltime = remaininglifetime;
 1181 
 1182                 if (TWOHOUR < new->ndpr_vltime ||
 1183                     remaininglifetime < new->ndpr_vltime) {
 1184                         lt6_tmp.ia6t_vltime = new->ndpr_vltime;
 1185                 } else if (remaininglifetime <= TWOHOUR) {
 1186                         if (auth) {
 1187                                 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
 1188                         }
 1189                 } else {
 1190                         /*
 1191                          * new->ndpr_vltime <= TWOHOUR &&
 1192                          * TWOHOUR < remaininglifetime
 1193                          */
 1194                         lt6_tmp.ia6t_vltime = TWOHOUR;
 1195                 }
 1196 
 1197                 /* The 2 hour rule is not imposed for preferred lifetime. */
 1198                 lt6_tmp.ia6t_pltime = new->ndpr_pltime;
 1199 
 1200                 in6_init_address_ltimes(pr, &lt6_tmp);
 1201 
 1202                 /*
 1203                  * We need to treat lifetimes for temporary addresses
 1204                  * differently, according to
 1205                  * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
 1206                  * we only update the lifetimes when they are in the maximum
 1207                  * intervals.
 1208                  */
 1209                 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
 1210                         u_int32_t maxvltime, maxpltime;
 1211 
 1212                         if (ip6_temp_valid_lifetime >
 1213                             (u_int32_t)((time_second - ifa6->ia6_createtime) +
 1214                             ip6_desync_factor)) {
 1215                                 maxvltime = ip6_temp_valid_lifetime -
 1216                                     (time_second - ifa6->ia6_createtime) -
 1217                                     ip6_desync_factor;
 1218                         } else
 1219                                 maxvltime = 0;
 1220                         if (ip6_temp_preferred_lifetime >
 1221                             (u_int32_t)((time_second - ifa6->ia6_createtime) +
 1222                             ip6_desync_factor)) {
 1223                                 maxpltime = ip6_temp_preferred_lifetime -
 1224                                     (time_second - ifa6->ia6_createtime) -
 1225                                     ip6_desync_factor;
 1226                         } else
 1227                                 maxpltime = 0;
 1228 
 1229                         if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
 1230                             lt6_tmp.ia6t_vltime > maxvltime) {
 1231                                 lt6_tmp.ia6t_vltime = maxvltime;
 1232                         }
 1233                         if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
 1234                             lt6_tmp.ia6t_pltime > maxpltime) {
 1235                                 lt6_tmp.ia6t_pltime = maxpltime;
 1236                         }
 1237                 }
 1238                 ifa6->ia6_lifetime = lt6_tmp;
 1239                 ifa6->ia6_updatetime = time_second;
 1240         }
 1241         if (ia6_match == NULL && new->ndpr_vltime) {
 1242                 int ifidlen;
 1243 
 1244                 /*
 1245                  * 5.5.3 (d) (continued)
 1246                  * No address matched and the valid lifetime is non-zero.
 1247                  * Create a new address.
 1248                  */
 1249 
 1250                 /*
 1251                  * Prefix Length check:
 1252                  * If the sum of the prefix length and interface identifier
 1253                  * length does not equal 128 bits, the Prefix Information
 1254                  * option MUST be ignored.  The length of the interface
 1255                  * identifier is defined in a separate link-type specific
 1256                  * document.
 1257                  */
 1258                 ifidlen = in6_if2idlen(ifp);
 1259                 if (ifidlen < 0) {
 1260                         /* this should not happen, so we always log it. */
 1261                         log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
 1262                             if_name(ifp));
 1263                         goto end;
 1264                 }
 1265                 if (ifidlen + pr->ndpr_plen != 128) {
 1266                         nd6log((LOG_INFO,
 1267                             "prelist_update: invalid prefixlen "
 1268                             "%d for %s, ignored\n",
 1269                             pr->ndpr_plen, if_name(ifp)));
 1270                         goto end;
 1271                 }
 1272 
 1273                 if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
 1274                         /*
 1275                          * note that we should use pr (not new) for reference.
 1276                          */
 1277                         pr->ndpr_refcnt++;
 1278                         ia6->ia6_ndpr = pr;
 1279 
 1280                         /*
 1281                          * RFC 3041 3.3 (2).
 1282                          * When a new public address is created as described
 1283                          * in RFC2462, also create a new temporary address.
 1284                          *
 1285                          * RFC 3041 3.5.
 1286                          * When an interface connects to a new link, a new
 1287                          * randomized interface identifier should be generated
 1288                          * immediately together with a new set of temporary
 1289                          * addresses.  Thus, we specifiy 1 as the 2nd arg of
 1290                          * in6_tmpifadd().
 1291                          */
 1292                         if (ip6_use_tempaddr) {
 1293                                 int e;
 1294                                 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
 1295                                         nd6log((LOG_NOTICE, "prelist_update: "
 1296                                             "failed to create a temporary "
 1297                                             "address, errno=%d\n",
 1298                                             e));
 1299                                 }
 1300                         }
 1301 
 1302                         /*
 1303                          * A newly added address might affect the status
 1304                          * of other addresses, so we check and update it.
 1305                          * XXX: what if address duplication happens?
 1306                          */
 1307                         pfxlist_onlink_check();
 1308                 } else {
 1309                         /* just set an error. do not bark here. */
 1310                         error = EADDRNOTAVAIL; /* XXX: might be unused. */
 1311                 }
 1312         }
 1313 
 1314  end:
 1315         splx(s);
 1316         return error;
 1317 }
 1318 
 1319 /*
 1320  * A supplement function used in the on-link detection below;
 1321  * detect if a given prefix has a (probably) reachable advertising router.
 1322  * XXX: lengthy function name...
 1323  */
 1324 static struct nd_pfxrouter *
 1325 find_pfxlist_reachable_router(pr)
 1326         struct nd_prefix *pr;
 1327 {
 1328         struct nd_pfxrouter *pfxrtr;
 1329         struct rtentry *rt;
 1330         struct llinfo_nd6 *ln;
 1331 
 1332         for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
 1333              pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
 1334                 if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
 1335                     pfxrtr->router->ifp)) &&
 1336                     (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
 1337                     ND6_IS_LLINFO_PROBREACH(ln))
 1338                         break;  /* found */
 1339         }
 1340 
 1341         return (pfxrtr);
 1342 }
 1343 
 1344 /*
 1345  * Check if each prefix in the prefix list has at least one available router
 1346  * that advertised the prefix (a router is "available" if its neighbor cache
 1347  * entry is reachable or probably reachable).
 1348  * If the check fails, the prefix may be off-link, because, for example,
 1349  * we have moved from the network but the lifetime of the prefix has not
 1350  * expired yet.  So we should not use the prefix if there is another prefix
 1351  * that has an available router.
 1352  * But, if there is no prefix that has an available router, we still regards
 1353  * all the prefixes as on-link.  This is because we can't tell if all the
 1354  * routers are simply dead or if we really moved from the network and there
 1355  * is no router around us.
 1356  */
 1357 void
 1358 pfxlist_onlink_check()
 1359 {
 1360         struct nd_prefix *pr;
 1361         struct in6_ifaddr *ifa;
 1362         struct nd_defrouter *dr;
 1363         struct nd_pfxrouter *pfxrtr = NULL;
 1364 
 1365         /*
 1366          * Check if there is a prefix that has a reachable advertising
 1367          * router.
 1368          */
 1369         for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1370                 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
 1371                         break;
 1372         }
 1373 
 1374         /*
 1375          * If we have no such prefix, check whether we still have a router
 1376          * that does not advertise any prefixes.
 1377          */
 1378         if (pr == NULL) {
 1379                 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
 1380                     dr = TAILQ_NEXT(dr, dr_entry)) {
 1381                         struct nd_prefix *pr0;
 1382 
 1383                         for (pr0 = nd_prefix.lh_first; pr0;
 1384                             pr0 = pr0->ndpr_next) {
 1385                                 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
 1386                                         break;
 1387                         }
 1388                         if (pfxrtr != NULL)
 1389                                 break;
 1390                 }
 1391         }
 1392         if (pr != NULL || (TAILQ_FIRST(&nd_defrouter) && pfxrtr == NULL)) {
 1393                 /*
 1394                  * There is at least one prefix that has a reachable router,
 1395                  * or at least a router which probably does not advertise
 1396                  * any prefixes.  The latter would be the case when we move
 1397                  * to a new link where we have a router that does not provide
 1398                  * prefixes and we configure an address by hand.
 1399                  * Detach prefixes which have no reachable advertising
 1400                  * router, and attach other prefixes.
 1401                  */
 1402                 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1403                         /* XXX: a link-local prefix should never be detached */
 1404                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1405                                 continue;
 1406 
 1407                         /*
 1408                          * we aren't interested in prefixes without the L bit
 1409                          * set.
 1410                          */
 1411                         if (pr->ndpr_raf_onlink == 0)
 1412                                 continue;
 1413 
 1414                         if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
 1415                             find_pfxlist_reachable_router(pr) == NULL)
 1416                                 pr->ndpr_stateflags |= NDPRF_DETACHED;
 1417                         if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
 1418                             find_pfxlist_reachable_router(pr) != 0)
 1419                                 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
 1420                 }
 1421         } else {
 1422                 /* there is no prefix that has a reachable router */
 1423                 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1424                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1425                                 continue;
 1426 
 1427                         if (pr->ndpr_raf_onlink == 0)
 1428                                 continue;
 1429 
 1430                         if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
 1431                                 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
 1432                 }
 1433         }
 1434 
 1435         /*
 1436          * Remove each interface route associated with a (just) detached
 1437          * prefix, and reinstall the interface route for a (just) attached
 1438          * prefix.  Note that all attempt of reinstallation does not
 1439          * necessarily success, when a same prefix is shared among multiple
 1440          * interfaces.  Such cases will be handled in nd6_prefix_onlink,
 1441          * so we don't have to care about them.
 1442          */
 1443         for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1444                 int e;
 1445 
 1446                 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1447                         continue;
 1448 
 1449                 if (pr->ndpr_raf_onlink == 0)
 1450                         continue;
 1451 
 1452                 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
 1453                     (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 1454                         if ((e = nd6_prefix_offlink(pr)) != 0) {
 1455                                 nd6log((LOG_ERR,
 1456                                     "pfxlist_onlink_check: failed to "
 1457                                     "make %s/%d offlink, errno=%d\n",
 1458                                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
 1459                                     pr->ndpr_plen, e));
 1460                         }
 1461                 }
 1462                 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
 1463                     (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
 1464                     pr->ndpr_raf_onlink) {
 1465                         if ((e = nd6_prefix_onlink(pr)) != 0) {
 1466                                 nd6log((LOG_ERR,
 1467                                     "pfxlist_onlink_check: failed to "
 1468                                     "make %s/%d onlink, errno=%d\n",
 1469                                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
 1470                                     pr->ndpr_plen, e));
 1471                         }
 1472                 }
 1473         }
 1474 
 1475         /*
 1476          * Changes on the prefix status might affect address status as well.
 1477          * Make sure that all addresses derived from an attached prefix are
 1478          * attached, and that all addresses derived from a detached prefix are
 1479          * detached.  Note, however, that a manually configured address should
 1480          * always be attached.
 1481          * The precise detection logic is same as the one for prefixes.
 1482          */
 1483         for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
 1484                 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
 1485                         continue;
 1486 
 1487                 if (ifa->ia6_ndpr == NULL) {
 1488                         /*
 1489                          * This can happen when we first configure the address
 1490                          * (i.e. the address exists, but the prefix does not).
 1491                          * XXX: complicated relationships...
 1492                          */
 1493                         continue;
 1494                 }
 1495 
 1496                 if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
 1497                         break;
 1498         }
 1499         if (ifa) {
 1500                 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
 1501                         if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1502                                 continue;
 1503 
 1504                         if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
 1505                                 continue;
 1506 
 1507                         if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
 1508                                 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
 1509                                         ifa->ia6_flags &= ~IN6_IFF_DETACHED;
 1510                                         ifa->ia6_flags |= IN6_IFF_TENTATIVE;
 1511                                         nd6_dad_start((struct ifaddr *)ifa, 0);
 1512                                 }
 1513                         } else {
 1514                                 ifa->ia6_flags |= IN6_IFF_DETACHED;
 1515                         }
 1516                 }
 1517         }
 1518         else {
 1519                 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
 1520                         if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1521                                 continue;
 1522 
 1523                         if (ifa->ia6_flags & IN6_IFF_DETACHED) {
 1524                                 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
 1525                                 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
 1526                                 /* Do we need a delay in this case? */
 1527                                 nd6_dad_start((struct ifaddr *)ifa, 0);
 1528                         }
 1529                 }
 1530         }
 1531 }
 1532 
 1533 int
 1534 nd6_prefix_onlink(pr)
 1535         struct nd_prefix *pr;
 1536 {
 1537         struct ifaddr *ifa;
 1538         struct ifnet *ifp = pr->ndpr_ifp;
 1539         struct sockaddr_in6 mask6;
 1540         struct nd_prefix *opr;
 1541         u_long rtflags;
 1542         int error = 0;
 1543         struct rtentry *rt = NULL;
 1544 
 1545         /* sanity check */
 1546         if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 1547                 nd6log((LOG_ERR,
 1548                     "nd6_prefix_onlink: %s/%d is already on-link\n",
 1549                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
 1550                 return (EEXIST);
 1551         }
 1552 
 1553         /*
 1554          * Add the interface route associated with the prefix.  Before
 1555          * installing the route, check if there's the same prefix on another
 1556          * interface, and the prefix has already installed the interface route.
 1557          * Although such a configuration is expected to be rare, we explicitly
 1558          * allow it.
 1559          */
 1560         for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
 1561                 if (opr == pr)
 1562                         continue;
 1563 
 1564                 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
 1565                         continue;
 1566 
 1567                 if (opr->ndpr_plen == pr->ndpr_plen &&
 1568                     in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
 1569                     &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
 1570                         return (0);
 1571         }
 1572 
 1573         /*
 1574          * We prefer link-local addresses as the associated interface address.
 1575          */
 1576         /* search for a link-local addr */
 1577         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
 1578             IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
 1579         if (ifa == NULL) {
 1580                 /* XXX: freebsd does not have ifa_ifwithaf */
 1581                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
 1582                         if (ifa->ifa_addr->sa_family == AF_INET6)
 1583                                 break;
 1584                 }
 1585                 /* should we care about ia6_flags? */
 1586         }
 1587         if (ifa == NULL) {
 1588                 /*
 1589                  * This can still happen, when, for example, we receive an RA
 1590                  * containing a prefix with the L bit set and the A bit clear,
 1591                  * after removing all IPv6 addresses on the receiving
 1592                  * interface.  This should, of course, be rare though.
 1593                  */
 1594                 nd6log((LOG_NOTICE,
 1595                     "nd6_prefix_onlink: failed to find any ifaddr"
 1596                     " to add route for a prefix(%s/%d) on %s\n",
 1597                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
 1598                     pr->ndpr_plen, if_name(ifp)));
 1599                 return (0);
 1600         }
 1601 
 1602         /*
 1603          * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
 1604          * ifa->ifa_rtrequest = nd6_rtrequest;
 1605          */
 1606         bzero(&mask6, sizeof(mask6));
 1607         mask6.sin6_len = sizeof(mask6);
 1608         mask6.sin6_addr = pr->ndpr_mask;
 1609         rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP;
 1610         if (nd6_need_cache(ifp)) {
 1611                 /* explicitly set in case ifa_flags does not set the flag. */
 1612                 rtflags |= RTF_CLONING;
 1613         } else {
 1614                 /*
 1615                  * explicitly clear the cloning bit in case ifa_flags sets it.
 1616                  */
 1617                 rtflags &= ~RTF_CLONING;
 1618         }
 1619         error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
 1620             ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt);
 1621         if (error == 0) {
 1622                 if (rt != NULL) /* this should be non NULL, though */
 1623                         nd6_rtmsg(RTM_ADD, rt);
 1624                 pr->ndpr_stateflags |= NDPRF_ONLINK;
 1625         } else {
 1626                 nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
 1627                     " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
 1628                     "errno = %d\n",
 1629                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr),
 1630                     pr->ndpr_plen, if_name(ifp),
 1631                     ip6_sprintf(&((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
 1632                     ip6_sprintf(&mask6.sin6_addr), rtflags, error));
 1633         }
 1634 
 1635         if (rt != NULL) {
 1636                 RT_LOCK(rt);
 1637                 RT_REMREF(rt);
 1638                 RT_UNLOCK(rt);
 1639         }
 1640 
 1641         return (error);
 1642 }
 1643 
 1644 int
 1645 nd6_prefix_offlink(pr)
 1646         struct nd_prefix *pr;
 1647 {
 1648         int error = 0;
 1649         struct ifnet *ifp = pr->ndpr_ifp;
 1650         struct nd_prefix *opr;
 1651         struct sockaddr_in6 sa6, mask6;
 1652         struct rtentry *rt = NULL;
 1653 
 1654         /* sanity check */
 1655         if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
 1656                 nd6log((LOG_ERR,
 1657                     "nd6_prefix_offlink: %s/%d is already off-link\n",
 1658                     ip6_sprintf(&pr->ndpr_prefix.sin6_addr), pr->ndpr_plen));
 1659                 return (EEXIST);
 1660         }
 1661 
 1662         bzero(&sa6, sizeof(sa6));
 1663         sa6.sin6_family = AF_INET6;
 1664         sa6.sin6_len = sizeof(sa6);
 1665         bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
 1666             sizeof(struct in6_addr));
 1667         bzero(&mask6, sizeof(mask6));
 1668         mask6.sin6_family = AF_INET6;
 1669         mask6.sin6_len = sizeof(sa6);
 1670         bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
 1671         error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
 1672             (struct sockaddr *)&mask6, 0, &rt);
 1673         if (error == 0) {
 1674                 pr->ndpr_stateflags &= ~NDPRF_ONLINK;
 1675 
 1676                 /* report the route deletion to the routing socket. */
 1677                 if (rt != NULL)
 1678                         nd6_rtmsg(RTM_DELETE, rt);
 1679 
 1680                 /*
 1681                  * There might be the same prefix on another interface,
 1682                  * the prefix which could not be on-link just because we have
 1683                  * the interface route (see comments in nd6_prefix_onlink).
 1684                  * If there's one, try to make the prefix on-link on the
 1685                  * interface.
 1686                  */
 1687                 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
 1688                         if (opr == pr)
 1689                                 continue;
 1690 
 1691                         if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
 1692                                 continue;
 1693 
 1694                         /*
 1695                          * KAME specific: detached prefixes should not be
 1696                          * on-link.
 1697                          */
 1698                         if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
 1699                                 continue;
 1700 
 1701                         if (opr->ndpr_plen == pr->ndpr_plen &&
 1702                             in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
 1703                             &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
 1704                                 int e;
 1705 
 1706                                 if ((e = nd6_prefix_onlink(opr)) != 0) {
 1707                                         nd6log((LOG_ERR,
 1708                                             "nd6_prefix_offlink: failed to "
 1709                                             "recover a prefix %s/%d from %s "
 1710                                             "to %s (errno = %d)\n",
 1711                                             ip6_sprintf(&opr->ndpr_prefix.sin6_addr),
 1712                                             opr->ndpr_plen, if_name(ifp),
 1713                                             if_name(opr->ndpr_ifp), e));
 1714                                 }
 1715                         }
 1716                 }
 1717         } else {
 1718                 /* XXX: can we still set the NDPRF_ONLINK flag? */
 1719                 nd6log((LOG_ERR,
 1720                     "nd6_prefix_offlink: failed to delete route: "
 1721                     "%s/%d on %s (errno = %d)\n",
 1722                     ip6_sprintf(&sa6.sin6_addr), pr->ndpr_plen, if_name(ifp),
 1723                     error));
 1724         }
 1725 
 1726         if (rt != NULL) {
 1727                 RTFREE(rt);
 1728         }
 1729 
 1730         return (error);
 1731 }
 1732 
 1733 static struct in6_ifaddr *
 1734 in6_ifadd(pr, mcast)
 1735         struct nd_prefixctl *pr;
 1736         int mcast;
 1737 {
 1738         struct ifnet *ifp = pr->ndpr_ifp;
 1739         struct ifaddr *ifa;
 1740         struct in6_aliasreq ifra;
 1741         struct in6_ifaddr *ia, *ib;
 1742         int error, plen0;
 1743         struct in6_addr mask;
 1744         int prefixlen = pr->ndpr_plen;
 1745         int updateflags;
 1746 
 1747         in6_prefixlen2mask(&mask, prefixlen);
 1748 
 1749         /*
 1750          * find a link-local address (will be interface ID).
 1751          * Is it really mandatory? Theoretically, a global or a site-local
 1752          * address can be configured without a link-local address, if we
 1753          * have a unique interface identifier...
 1754          *
 1755          * it is not mandatory to have a link-local address, we can generate
 1756          * interface identifier on the fly.  we do this because:
 1757          * (1) it should be the easiest way to find interface identifier.
 1758          * (2) RFC2462 5.4 suggesting the use of the same interface identifier
 1759          * for multiple addresses on a single interface, and possible shortcut
 1760          * of DAD.  we omitted DAD for this reason in the past.
 1761          * (3) a user can prevent autoconfiguration of global address
 1762          * by removing link-local address by hand (this is partly because we
 1763          * don't have other way to control the use of IPv6 on an interface.
 1764          * this has been our design choice - cf. NRL's "ifconfig auto").
 1765          * (4) it is easier to manage when an interface has addresses
 1766          * with the same interface identifier, than to have multiple addresses
 1767          * with different interface identifiers.
 1768          */
 1769         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
 1770         if (ifa)
 1771                 ib = (struct in6_ifaddr *)ifa;
 1772         else
 1773                 return NULL;
 1774 
 1775         /* prefixlen + ifidlen must be equal to 128 */
 1776         plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
 1777         if (prefixlen != plen0) {
 1778                 nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
 1779                     "(prefix=%d ifid=%d)\n",
 1780                     if_name(ifp), prefixlen, 128 - plen0));
 1781                 return NULL;
 1782         }
 1783 
 1784         /* make ifaddr */
 1785 
 1786         bzero(&ifra, sizeof(ifra));
 1787         /*
 1788          * in6_update_ifa() does not use ifra_name, but we accurately set it
 1789          * for safety.
 1790          */
 1791         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
 1792         ifra.ifra_addr.sin6_family = AF_INET6;
 1793         ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
 1794         /* prefix */
 1795         ifra.ifra_addr.sin6_addr = pr->ndpr_prefix.sin6_addr;
 1796         ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
 1797         ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
 1798         ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
 1799         ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
 1800 
 1801         /* interface ID */
 1802         ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
 1803             (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
 1804         ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
 1805             (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
 1806         ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
 1807             (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
 1808         ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
 1809             (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
 1810 
 1811         /* new prefix mask. */
 1812         ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
 1813         ifra.ifra_prefixmask.sin6_family = AF_INET6;
 1814         bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
 1815             sizeof(ifra.ifra_prefixmask.sin6_addr));
 1816 
 1817         /* lifetimes. */
 1818         ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
 1819         ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
 1820 
 1821         /* XXX: scope zone ID? */
 1822 
 1823         ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
 1824 
 1825         /*
 1826          * Make sure that we do not have this address already.  This should
 1827          * usually not happen, but we can still see this case, e.g., if we
 1828          * have manually configured the exact address to be configured.
 1829          */
 1830         if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
 1831                 /* this should be rare enough to make an explicit log */
 1832                 log(LOG_INFO, "in6_ifadd: %s is already configured\n",
 1833                     ip6_sprintf(&ifra.ifra_addr.sin6_addr));
 1834                 return (NULL);
 1835         }
 1836 
 1837         /*
 1838          * Allocate ifaddr structure, link into chain, etc.
 1839          * If we are going to create a new address upon receiving a multicasted
 1840          * RA, we need to impose a random delay before starting DAD.
 1841          * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
 1842          */
 1843         updateflags = 0;
 1844         if (mcast)
 1845                 updateflags |= IN6_IFAUPDATE_DADDELAY;
 1846         if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
 1847                 nd6log((LOG_ERR,
 1848                     "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
 1849                     ip6_sprintf(&ifra.ifra_addr.sin6_addr), if_name(ifp),
 1850                     error));
 1851                 return (NULL);  /* ifaddr must not have been allocated. */
 1852         }
 1853 
 1854         ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
 1855 
 1856         return (ia);            /* this is always non-NULL */
 1857 }
 1858 
 1859 int
 1860 in6_tmpifadd(ia0, forcegen, delay)
 1861         const struct in6_ifaddr *ia0; /* corresponding public address */
 1862         int forcegen, delay;
 1863 {
 1864         struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
 1865         struct in6_ifaddr *newia, *ia;
 1866         struct in6_aliasreq ifra;
 1867         int i, error;
 1868         int trylimit = 3;       /* XXX: adhoc value */
 1869         int updateflags;
 1870         u_int32_t randid[2];
 1871         time_t vltime0, pltime0;
 1872 
 1873         bzero(&ifra, sizeof(ifra));
 1874         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
 1875         ifra.ifra_addr = ia0->ia_addr;
 1876         /* copy prefix mask */
 1877         ifra.ifra_prefixmask = ia0->ia_prefixmask;
 1878         /* clear the old IFID */
 1879         for (i = 0; i < 4; i++) {
 1880                 ifra.ifra_addr.sin6_addr.s6_addr32[i] &=
 1881                     ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
 1882         }
 1883 
 1884   again:
 1885         if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
 1886             (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
 1887                 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
 1888                     "random IFID\n"));
 1889                 return (EINVAL);
 1890         }
 1891         ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
 1892             (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
 1893         ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
 1894             (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
 1895 
 1896         /*
 1897          * in6_get_tmpifid() quite likely provided a unique interface ID.
 1898          * However, we may still have a chance to see collision, because
 1899          * there may be a time lag between generation of the ID and generation
 1900          * of the address.  So, we'll do one more sanity check.
 1901          */
 1902         for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
 1903                 if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
 1904                     &ifra.ifra_addr.sin6_addr)) {
 1905                         if (trylimit-- == 0) {
 1906                                 /*
 1907                                  * Give up.  Something strange should have
 1908                                  * happened.
 1909                                  */
 1910                                 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
 1911                                     "find a unique random IFID\n"));
 1912                                 return (EEXIST);
 1913                         }
 1914                         forcegen = 1;
 1915                         goto again;
 1916                 }
 1917         }
 1918 
 1919         /*
 1920          * The Valid Lifetime is the lower of the Valid Lifetime of the
 1921          * public address or TEMP_VALID_LIFETIME.
 1922          * The Preferred Lifetime is the lower of the Preferred Lifetime
 1923          * of the public address or TEMP_PREFERRED_LIFETIME -
 1924          * DESYNC_FACTOR.
 1925          */
 1926         if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
 1927                 vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
 1928                     (ia0->ia6_lifetime.ia6t_vltime -
 1929                     (time_second - ia0->ia6_updatetime));
 1930                 if (vltime0 > ip6_temp_valid_lifetime)
 1931                         vltime0 = ip6_temp_valid_lifetime;
 1932         } else
 1933                 vltime0 = ip6_temp_valid_lifetime;
 1934         if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
 1935                 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
 1936                     (ia0->ia6_lifetime.ia6t_pltime -
 1937                     (time_second - ia0->ia6_updatetime));
 1938                 if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){
 1939                         pltime0 = ip6_temp_preferred_lifetime -
 1940                             ip6_desync_factor;
 1941                 }
 1942         } else
 1943                 pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
 1944         ifra.ifra_lifetime.ia6t_vltime = vltime0;
 1945         ifra.ifra_lifetime.ia6t_pltime = pltime0;
 1946 
 1947         /*
 1948          * A temporary address is created only if this calculated Preferred
 1949          * Lifetime is greater than REGEN_ADVANCE time units.
 1950          */
 1951         if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
 1952                 return (0);
 1953 
 1954         /* XXX: scope zone ID? */
 1955 
 1956         ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
 1957 
 1958         /* allocate ifaddr structure, link into chain, etc. */
 1959         updateflags = 0;
 1960         if (delay)
 1961                 updateflags |= IN6_IFAUPDATE_DADDELAY;
 1962         if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
 1963                 return (error);
 1964 
 1965         newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
 1966         if (newia == NULL) {    /* XXX: can it happen? */
 1967                 nd6log((LOG_ERR,
 1968                     "in6_tmpifadd: ifa update succeeded, but we got "
 1969                     "no ifaddr\n"));
 1970                 return (EINVAL); /* XXX */
 1971         }
 1972         newia->ia6_ndpr = ia0->ia6_ndpr;
 1973         newia->ia6_ndpr->ndpr_refcnt++;
 1974 
 1975         /*
 1976          * A newly added address might affect the status of other addresses.
 1977          * XXX: when the temporary address is generated with a new public
 1978          * address, the onlink check is redundant.  However, it would be safe
 1979          * to do the check explicitly everywhere a new address is generated,
 1980          * and, in fact, we surely need the check when we create a new
 1981          * temporary address due to deprecation of an old temporary address.
 1982          */
 1983         pfxlist_onlink_check();
 1984 
 1985         return (0);
 1986 }
 1987 
 1988 static int
 1989 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
 1990 {
 1991         if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
 1992                 ndpr->ndpr_preferred = 0;
 1993         else
 1994                 ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
 1995         if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
 1996                 ndpr->ndpr_expire = 0;
 1997         else
 1998                 ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
 1999 
 2000         return 0;
 2001 }
 2002 
 2003 static void
 2004 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
 2005 {
 2006         /* init ia6t_expire */
 2007         if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
 2008                 lt6->ia6t_expire = 0;
 2009         else {
 2010                 lt6->ia6t_expire = time_second;
 2011                 lt6->ia6t_expire += lt6->ia6t_vltime;
 2012         }
 2013 
 2014         /* init ia6t_preferred */
 2015         if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
 2016                 lt6->ia6t_preferred = 0;
 2017         else {
 2018                 lt6->ia6t_preferred = time_second;
 2019                 lt6->ia6t_preferred += lt6->ia6t_pltime;
 2020         }
 2021 }
 2022 
 2023 /*
 2024  * Delete all the routing table entries that use the specified gateway.
 2025  * XXX: this function causes search through all entries of routing table, so
 2026  * it shouldn't be called when acting as a router.
 2027  */
 2028 void
 2029 rt6_flush(gateway, ifp)
 2030         struct in6_addr *gateway;
 2031         struct ifnet *ifp;
 2032 {
 2033         struct radix_node_head *rnh = rt_tables[AF_INET6];
 2034         int s = splnet();
 2035 
 2036         /* We'll care only link-local addresses */
 2037         if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
 2038                 splx(s);
 2039                 return;
 2040         }
 2041 
 2042         RADIX_NODE_HEAD_LOCK(rnh);
 2043         rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
 2044         RADIX_NODE_HEAD_UNLOCK(rnh);
 2045         splx(s);
 2046 }
 2047 
 2048 static int
 2049 rt6_deleteroute(rn, arg)
 2050         struct radix_node *rn;
 2051         void *arg;
 2052 {
 2053 #define SIN6(s) ((struct sockaddr_in6 *)s)
 2054         struct rtentry *rt = (struct rtentry *)rn;
 2055         struct in6_addr *gate = (struct in6_addr *)arg;
 2056 
 2057         if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
 2058                 return (0);
 2059 
 2060         if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) {
 2061                 return (0);
 2062         }
 2063 
 2064         /*
 2065          * Do not delete a static route.
 2066          * XXX: this seems to be a bit ad-hoc. Should we consider the
 2067          * 'cloned' bit instead?
 2068          */
 2069         if ((rt->rt_flags & RTF_STATIC) != 0)
 2070                 return (0);
 2071 
 2072         /*
 2073          * We delete only host route. This means, in particular, we don't
 2074          * delete default route.
 2075          */
 2076         if ((rt->rt_flags & RTF_HOST) == 0)
 2077                 return (0);
 2078 
 2079         return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
 2080             rt_mask(rt), rt->rt_flags, 0));
 2081 #undef SIN6
 2082 }
 2083 
 2084 int
 2085 nd6_setdefaultiface(ifindex)
 2086         int ifindex;
 2087 {
 2088         int error = 0;
 2089 
 2090         if (ifindex < 0 || if_index < ifindex)
 2091                 return (EINVAL);
 2092         if (ifindex != 0 && !ifnet_byindex(ifindex))
 2093                 return (EINVAL);
 2094 
 2095         if (nd6_defifindex != ifindex) {
 2096                 nd6_defifindex = ifindex;
 2097                 if (nd6_defifindex > 0)
 2098                         nd6_defifp = ifnet_byindex(nd6_defifindex);
 2099                 else
 2100                         nd6_defifp = NULL;
 2101 
 2102                 /*
 2103                  * Our current implementation assumes one-to-one maping between
 2104                  * interfaces and links, so it would be natural to use the
 2105                  * default interface as the default link.
 2106                  */
 2107                 scope6_setdefault(nd6_defifp);
 2108         }
 2109 
 2110         return (error);
 2111 }

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