The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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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: releng/7.4/sys/netinet6/nd6_rtr.c 182632 2008-09-01 19:23:04Z obrien $");
   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 #define SDL(s)  ((struct sockaddr_dl *)s)
   66 
   67 static int rtpref(struct nd_defrouter *);
   68 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
   69 static int prelist_update __P((struct nd_prefixctl *, struct nd_defrouter *,
   70     struct mbuf *, int));
   71 static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *,      int);
   72 static struct nd_pfxrouter *pfxrtr_lookup __P((struct nd_prefix *,
   73         struct nd_defrouter *));
   74 static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
   75 static void pfxrtr_del(struct nd_pfxrouter *);
   76 static struct nd_pfxrouter *find_pfxlist_reachable_router
   77 (struct nd_prefix *);
   78 static void defrouter_delreq(struct nd_defrouter *);
   79 static void nd6_rtmsg(int, struct rtentry *);
   80 
   81 static int in6_init_prefix_ltimes(struct nd_prefix *);
   82 static void in6_init_address_ltimes __P((struct nd_prefix *,
   83         struct in6_addrlifetime *));
   84 
   85 static int rt6_deleteroute(struct radix_node *, void *);
   86 
   87 extern int nd6_recalc_reachtm_interval;
   88 
   89 static struct ifnet *nd6_defifp;
   90 int nd6_defifindex;
   91 
   92 int ip6_use_tempaddr = 0;
   93 
   94 int ip6_desync_factor;
   95 u_int32_t ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
   96 u_int32_t ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
   97 /*
   98  * shorter lifetimes for debugging purposes.
   99 int ip6_temp_preferred_lifetime = 800;
  100 static int ip6_temp_valid_lifetime = 1800;
  101 */
  102 int ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
  103 
  104 /* RTPREF_MEDIUM has to be 0! */
  105 #define RTPREF_HIGH     1
  106 #define RTPREF_MEDIUM   0
  107 #define RTPREF_LOW      (-1)
  108 #define RTPREF_RESERVED (-2)
  109 #define RTPREF_INVALID  (-3)    /* internal */
  110 
  111 /*
  112  * Receive Router Solicitation Message - just for routers.
  113  * Router solicitation/advertisement is mostly managed by userland program
  114  * (rtadvd) so here we have no function like nd6_ra_output().
  115  *
  116  * Based on RFC 2461
  117  */
  118 void
  119 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
  120 {
  121         struct ifnet *ifp = m->m_pkthdr.rcvif;
  122         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  123         struct nd_router_solicit *nd_rs;
  124         struct in6_addr saddr6 = ip6->ip6_src;
  125         char *lladdr = NULL;
  126         int lladdrlen = 0;
  127         union nd_opts ndopts;
  128         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  129 
  130         /* If I'm not a router, ignore it. */
  131         if (ip6_accept_rtadv != 0 || ip6_forwarding != 1)
  132                 goto freeit;
  133 
  134         /* Sanity checks */
  135         if (ip6->ip6_hlim != 255) {
  136                 nd6log((LOG_ERR,
  137                     "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
  138                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  139                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  140                 goto bad;
  141         }
  142 
  143         /*
  144          * Don't update the neighbor cache, if src = ::.
  145          * This indicates that the src has no IP address assigned yet.
  146          */
  147         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
  148                 goto freeit;
  149 
  150 #ifndef PULLDOWN_TEST
  151         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  152         nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
  153 #else
  154         IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
  155         if (nd_rs == NULL) {
  156                 icmp6stat.icp6s_tooshort++;
  157                 return;
  158         }
  159 #endif
  160 
  161         icmp6len -= sizeof(*nd_rs);
  162         nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
  163         if (nd6_options(&ndopts) < 0) {
  164                 nd6log((LOG_INFO,
  165                     "nd6_rs_input: invalid ND option, ignored\n"));
  166                 /* nd6_options have incremented stats */
  167                 goto freeit;
  168         }
  169 
  170         if (ndopts.nd_opts_src_lladdr) {
  171                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  172                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  173         }
  174 
  175         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  176                 nd6log((LOG_INFO,
  177                     "nd6_rs_input: lladdrlen mismatch for %s "
  178                     "(if %d, RS packet %d)\n",
  179                     ip6_sprintf(ip6bufs, &saddr6),
  180                     ifp->if_addrlen, lladdrlen - 2));
  181                 goto bad;
  182         }
  183 
  184         nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
  185 
  186  freeit:
  187         m_freem(m);
  188         return;
  189 
  190  bad:
  191         icmp6stat.icp6s_badrs++;
  192         m_freem(m);
  193 }
  194 
  195 /*
  196  * Receive Router Advertisement Message.
  197  *
  198  * Based on RFC 2461
  199  * TODO: on-link bit on prefix information
  200  * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
  201  */
  202 void
  203 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
  204 {
  205         struct ifnet *ifp = m->m_pkthdr.rcvif;
  206         struct nd_ifinfo *ndi = ND_IFINFO(ifp);
  207         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  208         struct nd_router_advert *nd_ra;
  209         struct in6_addr saddr6 = ip6->ip6_src;
  210         int mcast = 0;
  211         union nd_opts ndopts;
  212         struct nd_defrouter *dr;
  213         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  214 
  215         /*
  216          * We only accept RAs only when
  217          * the system-wide variable allows the acceptance, and
  218          * per-interface variable allows RAs on the receiving interface.
  219          */
  220         if (ip6_accept_rtadv == 0)
  221                 goto freeit;
  222         if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
  223                 goto freeit;
  224 
  225         if (ip6->ip6_hlim != 255) {
  226                 nd6log((LOG_ERR,
  227                     "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
  228                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  229                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  230                 goto bad;
  231         }
  232 
  233         if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
  234                 nd6log((LOG_ERR,
  235                     "nd6_ra_input: src %s is not link-local\n",
  236                     ip6_sprintf(ip6bufs, &saddr6)));
  237                 goto bad;
  238         }
  239 
  240 #ifndef PULLDOWN_TEST
  241         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  242         nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
  243 #else
  244         IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
  245         if (nd_ra == NULL) {
  246                 icmp6stat.icp6s_tooshort++;
  247                 return;
  248         }
  249 #endif
  250 
  251         icmp6len -= sizeof(*nd_ra);
  252         nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
  253         if (nd6_options(&ndopts) < 0) {
  254                 nd6log((LOG_INFO,
  255                     "nd6_ra_input: invalid ND option, ignored\n"));
  256                 /* nd6_options have incremented stats */
  257                 goto freeit;
  258         }
  259 
  260     {
  261         struct nd_defrouter dr0;
  262         u_int32_t advreachable = nd_ra->nd_ra_reachable;
  263 
  264         /* remember if this is a multicasted advertisement */
  265         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
  266                 mcast = 1;
  267 
  268         bzero(&dr0, sizeof(dr0));
  269         dr0.rtaddr = saddr6;
  270         dr0.flags  = nd_ra->nd_ra_flags_reserved;
  271         dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
  272         dr0.expire = time_second + dr0.rtlifetime;
  273         dr0.ifp = ifp;
  274         /* unspecified or not? (RFC 2461 6.3.4) */
  275         if (advreachable) {
  276                 advreachable = ntohl(advreachable);
  277                 if (advreachable <= MAX_REACHABLE_TIME &&
  278                     ndi->basereachable != advreachable) {
  279                         ndi->basereachable = advreachable;
  280                         ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
  281                         ndi->recalctm = nd6_recalc_reachtm_interval; /* reset */
  282                 }
  283         }
  284         if (nd_ra->nd_ra_retransmit)
  285                 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
  286         if (nd_ra->nd_ra_curhoplimit)
  287                 ndi->chlim = nd_ra->nd_ra_curhoplimit;
  288         dr = defrtrlist_update(&dr0);
  289     }
  290 
  291         /*
  292          * prefix
  293          */
  294         if (ndopts.nd_opts_pi) {
  295                 struct nd_opt_hdr *pt;
  296                 struct nd_opt_prefix_info *pi = NULL;
  297                 struct nd_prefixctl pr;
  298 
  299                 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
  300                      pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
  301                      pt = (struct nd_opt_hdr *)((caddr_t)pt +
  302                                                 (pt->nd_opt_len << 3))) {
  303                         if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
  304                                 continue;
  305                         pi = (struct nd_opt_prefix_info *)pt;
  306 
  307                         if (pi->nd_opt_pi_len != 4) {
  308                                 nd6log((LOG_INFO,
  309                                     "nd6_ra_input: invalid option "
  310                                     "len %d for prefix information option, "
  311                                     "ignored\n", pi->nd_opt_pi_len));
  312                                 continue;
  313                         }
  314 
  315                         if (128 < pi->nd_opt_pi_prefix_len) {
  316                                 nd6log((LOG_INFO,
  317                                     "nd6_ra_input: invalid prefix "
  318                                     "len %d for prefix information option, "
  319                                     "ignored\n", pi->nd_opt_pi_prefix_len));
  320                                 continue;
  321                         }
  322 
  323                         if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
  324                          || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
  325                                 nd6log((LOG_INFO,
  326                                     "nd6_ra_input: invalid prefix "
  327                                     "%s, ignored\n",
  328                                     ip6_sprintf(ip6bufs,
  329                                         &pi->nd_opt_pi_prefix)));
  330                                 continue;
  331                         }
  332 
  333                         bzero(&pr, sizeof(pr));
  334                         pr.ndpr_prefix.sin6_family = AF_INET6;
  335                         pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
  336                         pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
  337                         pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
  338 
  339                         pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
  340                             ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
  341                         pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
  342                             ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
  343                         pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
  344                         pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
  345                         pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
  346                         (void)prelist_update(&pr, dr, m, mcast);
  347                 }
  348         }
  349 
  350         /*
  351          * MTU
  352          */
  353         if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
  354                 u_long mtu;
  355                 u_long maxmtu;
  356 
  357                 mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
  358 
  359                 /* lower bound */
  360                 if (mtu < IPV6_MMTU) {
  361                         nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
  362                             "mtu=%lu sent from %s, ignoring\n",
  363                             mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src)));
  364                         goto skip;
  365                 }
  366 
  367                 /* upper bound */
  368                 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
  369                     ? ndi->maxmtu : ifp->if_mtu;
  370                 if (mtu <= maxmtu) {
  371                         int change = (ndi->linkmtu != mtu);
  372 
  373                         ndi->linkmtu = mtu;
  374                         if (change) /* in6_maxmtu may change */
  375                                 in6_setmaxmtu();
  376                 } else {
  377                         nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
  378                             "mtu=%lu sent from %s; "
  379                             "exceeds maxmtu %lu, ignoring\n",
  380                             mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu));
  381                 }
  382         }
  383 
  384  skip:
  385 
  386         /*
  387          * Source link layer address
  388          */
  389     {
  390         char *lladdr = NULL;
  391         int lladdrlen = 0;
  392 
  393         if (ndopts.nd_opts_src_lladdr) {
  394                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  395                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  396         }
  397 
  398         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  399                 nd6log((LOG_INFO,
  400                     "nd6_ra_input: lladdrlen mismatch for %s "
  401                     "(if %d, RA packet %d)\n", ip6_sprintf(ip6bufs, &saddr6),
  402                     ifp->if_addrlen, lladdrlen - 2));
  403                 goto bad;
  404         }
  405 
  406         nd6_cache_lladdr(ifp, &saddr6, lladdr,
  407             lladdrlen, ND_ROUTER_ADVERT, 0);
  408 
  409         /*
  410          * Installing a link-layer address might change the state of the
  411          * router's neighbor cache, which might also affect our on-link
  412          * detection of adveritsed prefixes.
  413          */
  414         pfxlist_onlink_check();
  415     }
  416 
  417  freeit:
  418         m_freem(m);
  419         return;
  420 
  421  bad:
  422         icmp6stat.icp6s_badra++;
  423         m_freem(m);
  424 }
  425 
  426 /*
  427  * default router list proccessing sub routines
  428  */
  429 
  430 /* tell the change to user processes watching the routing socket. */
  431 static void
  432 nd6_rtmsg(int cmd, struct rtentry *rt)
  433 {
  434         struct rt_addrinfo info;
  435 
  436         bzero((caddr_t)&info, sizeof(info));
  437         info.rti_info[RTAX_DST] = rt_key(rt);
  438         info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
  439         info.rti_info[RTAX_NETMASK] = rt_mask(rt);
  440         if (rt->rt_ifp) {
  441                 info.rti_info[RTAX_IFP] =
  442                     TAILQ_FIRST(&rt->rt_ifp->if_addrlist)->ifa_addr;
  443                 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
  444         }
  445 
  446         rt_missmsg(cmd, &info, rt->rt_flags, 0);
  447 }
  448 
  449 void
  450 defrouter_addreq(struct nd_defrouter *new)
  451 {
  452         struct sockaddr_in6 def, mask, gate;
  453         struct rtentry *newrt = NULL;
  454         int s;
  455         int error;
  456 
  457         bzero(&def, sizeof(def));
  458         bzero(&mask, sizeof(mask));
  459         bzero(&gate, sizeof(gate));
  460 
  461         def.sin6_len = mask.sin6_len = gate.sin6_len =
  462             sizeof(struct sockaddr_in6);
  463         def.sin6_family = gate.sin6_family = AF_INET6;
  464         gate.sin6_addr = new->rtaddr;
  465 
  466         s = splnet();
  467         error = rtrequest(RTM_ADD, (struct sockaddr *)&def,
  468             (struct sockaddr *)&gate, (struct sockaddr *)&mask,
  469             RTF_GATEWAY, &newrt);
  470         if (newrt) {
  471                 RT_LOCK(newrt);
  472                 nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
  473                 RT_REMREF(newrt);
  474                 RT_UNLOCK(newrt);
  475         }
  476         if (error == 0)
  477                 new->installed = 1;
  478         splx(s);
  479         return;
  480 }
  481 
  482 struct nd_defrouter *
  483 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
  484 {
  485         struct nd_defrouter *dr;
  486 
  487         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  488              dr = TAILQ_NEXT(dr, dr_entry)) {
  489                 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr))
  490                         return (dr);
  491         }
  492 
  493         return (NULL);          /* search failed */
  494 }
  495 
  496 /*
  497  * Remove the default route for a given router.
  498  * This is just a subroutine function for defrouter_select(), and should
  499  * not be called from anywhere else.
  500  */
  501 static void
  502 defrouter_delreq(struct nd_defrouter *dr)
  503 {
  504         struct sockaddr_in6 def, mask, gate;
  505         struct rtentry *oldrt = NULL;
  506 
  507         bzero(&def, sizeof(def));
  508         bzero(&mask, sizeof(mask));
  509         bzero(&gate, sizeof(gate));
  510 
  511         def.sin6_len = mask.sin6_len = gate.sin6_len =
  512             sizeof(struct sockaddr_in6);
  513         def.sin6_family = gate.sin6_family = AF_INET6;
  514         gate.sin6_addr = dr->rtaddr;
  515 
  516         rtrequest(RTM_DELETE, (struct sockaddr *)&def,
  517             (struct sockaddr *)&gate,
  518             (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt);
  519         if (oldrt) {
  520                 nd6_rtmsg(RTM_DELETE, oldrt);
  521                 RTFREE(oldrt);
  522         }
  523 
  524         dr->installed = 0;
  525 }
  526 
  527 /*
  528  * remove all default routes from default router list
  529  */
  530 void
  531 defrouter_reset(void)
  532 {
  533         struct nd_defrouter *dr;
  534 
  535         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  536              dr = TAILQ_NEXT(dr, dr_entry))
  537                 defrouter_delreq(dr);
  538 
  539         /*
  540          * XXX should we also nuke any default routers in the kernel, by
  541          * going through them by rtalloc1()?
  542          */
  543 }
  544 
  545 void
  546 defrtrlist_del(struct nd_defrouter *dr)
  547 {
  548         struct nd_defrouter *deldr = NULL;
  549         struct nd_prefix *pr;
  550 
  551         /*
  552          * Flush all the routing table entries that use the router
  553          * as a next hop.
  554          */
  555         if (!ip6_forwarding && ip6_accept_rtadv) /* XXX: better condition? */
  556                 rt6_flush(&dr->rtaddr, dr->ifp);
  557 
  558         if (dr->installed) {
  559                 deldr = dr;
  560                 defrouter_delreq(dr);
  561         }
  562         TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
  563 
  564         /*
  565          * Also delete all the pointers to the router in each prefix lists.
  566          */
  567         for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
  568                 struct nd_pfxrouter *pfxrtr;
  569                 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
  570                         pfxrtr_del(pfxrtr);
  571         }
  572         pfxlist_onlink_check();
  573 
  574         /*
  575          * If the router is the primary one, choose a new one.
  576          * Note that defrouter_select() will remove the current gateway
  577          * from the routing table.
  578          */
  579         if (deldr)
  580                 defrouter_select();
  581 
  582         free(dr, M_IP6NDP);
  583 }
  584 
  585 /*
  586  * Default Router Selection according to Section 6.3.6 of RFC 2461 and
  587  * draft-ietf-ipngwg-router-selection:
  588  * 1) Routers that are reachable or probably reachable should be preferred.
  589  *    If we have more than one (probably) reachable router, prefer ones
  590  *    with the highest router preference.
  591  * 2) When no routers on the list are known to be reachable or
  592  *    probably reachable, routers SHOULD be selected in a round-robin
  593  *    fashion, regardless of router preference values.
  594  * 3) If the Default Router List is empty, assume that all
  595  *    destinations are on-link.
  596  *
  597  * We assume nd_defrouter is sorted by router preference value.
  598  * Since the code below covers both with and without router preference cases,
  599  * we do not need to classify the cases by ifdef.
  600  *
  601  * At this moment, we do not try to install more than one default router,
  602  * even when the multipath routing is available, because we're not sure about
  603  * the benefits for stub hosts comparing to the risk of making the code
  604  * complicated and the possibility of introducing bugs.
  605  */
  606 void
  607 defrouter_select(void)
  608 {
  609         int s = splnet();
  610         struct nd_defrouter *dr, *selected_dr = NULL, *installed_dr = NULL;
  611         struct rtentry *rt = NULL;
  612         struct llinfo_nd6 *ln = NULL;
  613 
  614         /*
  615          * This function should be called only when acting as an autoconfigured
  616          * host.  Although the remaining part of this function is not effective
  617          * if the node is not an autoconfigured host, we explicitly exclude
  618          * such cases here for safety.
  619          */
  620         if (ip6_forwarding || !ip6_accept_rtadv) {
  621                 nd6log((LOG_WARNING,
  622                     "defrouter_select: called unexpectedly (forwarding=%d, "
  623                     "accept_rtadv=%d)\n", ip6_forwarding, ip6_accept_rtadv));
  624                 splx(s);
  625                 return;
  626         }
  627 
  628         /*
  629          * Let's handle easy case (3) first:
  630          * If default router list is empty, there's nothing to be done.
  631          */
  632         if (!TAILQ_FIRST(&nd_defrouter)) {
  633                 splx(s);
  634                 return;
  635         }
  636 
  637         /*
  638          * Search for a (probably) reachable router from the list.
  639          * We just pick up the first reachable one (if any), assuming that
  640          * the ordering rule of the list described in defrtrlist_update().
  641          */
  642         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  643              dr = TAILQ_NEXT(dr, dr_entry)) {
  644                 if (selected_dr == NULL &&
  645                     (rt = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
  646                     (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
  647                     ND6_IS_LLINFO_PROBREACH(ln)) {
  648                         selected_dr = dr;
  649                 }
  650 
  651                 if (dr->installed && installed_dr == NULL)
  652                         installed_dr = dr;
  653                 else if (dr->installed && installed_dr) {
  654                         /* this should not happen.  warn for diagnosis. */
  655                         log(LOG_ERR, "defrouter_select: more than one router"
  656                             " is installed\n");
  657                 }
  658         }
  659         /*
  660          * If none of the default routers was found to be reachable,
  661          * round-robin the list regardless of preference.
  662          * Otherwise, if we have an installed router, check if the selected
  663          * (reachable) router should really be preferred to the installed one.
  664          * We only prefer the new router when the old one is not reachable
  665          * or when the new one has a really higher preference value.
  666          */
  667         if (selected_dr == NULL) {
  668                 if (installed_dr == NULL || !TAILQ_NEXT(installed_dr, dr_entry))
  669                         selected_dr = TAILQ_FIRST(&nd_defrouter);
  670                 else
  671                         selected_dr = TAILQ_NEXT(installed_dr, dr_entry);
  672         } else if (installed_dr &&
  673             (rt = nd6_lookup(&installed_dr->rtaddr, 0, installed_dr->ifp)) &&
  674             (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
  675             ND6_IS_LLINFO_PROBREACH(ln) &&
  676             rtpref(selected_dr) <= rtpref(installed_dr)) {
  677                 selected_dr = installed_dr;
  678         }
  679 
  680         /*
  681          * If the selected router is different than the installed one,
  682          * remove the installed router and install the selected one.
  683          * Note that the selected router is never NULL here.
  684          */
  685         if (installed_dr != selected_dr) {
  686                 if (installed_dr)
  687                         defrouter_delreq(installed_dr);
  688                 defrouter_addreq(selected_dr);
  689         }
  690 
  691         splx(s);
  692         return;
  693 }
  694 
  695 /*
  696  * for default router selection
  697  * regards router-preference field as a 2-bit signed integer
  698  */
  699 static int
  700 rtpref(struct nd_defrouter *dr)
  701 {
  702         switch (dr->flags & ND_RA_FLAG_RTPREF_MASK) {
  703         case ND_RA_FLAG_RTPREF_HIGH:
  704                 return (RTPREF_HIGH);
  705         case ND_RA_FLAG_RTPREF_MEDIUM:
  706         case ND_RA_FLAG_RTPREF_RSV:
  707                 return (RTPREF_MEDIUM);
  708         case ND_RA_FLAG_RTPREF_LOW:
  709                 return (RTPREF_LOW);
  710         default:
  711                 /*
  712                  * This case should never happen.  If it did, it would mean a
  713                  * serious bug of kernel internal.  We thus always bark here.
  714                  * Or, can we even panic?
  715                  */
  716                 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->flags);
  717                 return (RTPREF_INVALID);
  718         }
  719         /* NOTREACHED */
  720 }
  721 
  722 static struct nd_defrouter *
  723 defrtrlist_update(struct nd_defrouter *new)
  724 {
  725         struct nd_defrouter *dr, *n;
  726         int s = splnet();
  727 
  728         if ((dr = defrouter_lookup(&new->rtaddr, new->ifp)) != NULL) {
  729                 /* entry exists */
  730                 if (new->rtlifetime == 0) {
  731                         defrtrlist_del(dr);
  732                         dr = NULL;
  733                 } else {
  734                         int oldpref = rtpref(dr);
  735 
  736                         /* override */
  737                         dr->flags = new->flags; /* xxx flag check */
  738                         dr->rtlifetime = new->rtlifetime;
  739                         dr->expire = new->expire;
  740 
  741                         /*
  742                          * If the preference does not change, there's no need
  743                          * to sort the entries.
  744                          */
  745                         if (rtpref(new) == oldpref) {
  746                                 splx(s);
  747                                 return (dr);
  748                         }
  749 
  750                         /*
  751                          * preferred router may be changed, so relocate
  752                          * this router.
  753                          * XXX: calling TAILQ_REMOVE directly is a bad manner.
  754                          * However, since defrtrlist_del() has many side
  755                          * effects, we intentionally do so here.
  756                          * defrouter_select() below will handle routing
  757                          * changes later.
  758                          */
  759                         TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
  760                         n = dr;
  761                         goto insert;
  762                 }
  763                 splx(s);
  764                 return (dr);
  765         }
  766 
  767         /* entry does not exist */
  768         if (new->rtlifetime == 0) {
  769                 splx(s);
  770                 return (NULL);
  771         }
  772 
  773         n = (struct nd_defrouter *)malloc(sizeof(*n), M_IP6NDP, M_NOWAIT);
  774         if (n == NULL) {
  775                 splx(s);
  776                 return (NULL);
  777         }
  778         bzero(n, sizeof(*n));
  779         *n = *new;
  780 
  781 insert:
  782         /*
  783          * Insert the new router in the Default Router List;
  784          * The Default Router List should be in the descending order
  785          * of router-preferece.  Routers with the same preference are
  786          * sorted in the arriving time order.
  787          */
  788 
  789         /* insert at the end of the group */
  790         for (dr = TAILQ_FIRST(&nd_defrouter); dr;
  791              dr = TAILQ_NEXT(dr, dr_entry)) {
  792                 if (rtpref(n) > rtpref(dr))
  793                         break;
  794         }
  795         if (dr)
  796                 TAILQ_INSERT_BEFORE(dr, n, dr_entry);
  797         else
  798                 TAILQ_INSERT_TAIL(&nd_defrouter, n, dr_entry);
  799 
  800         defrouter_select();
  801 
  802         splx(s);
  803 
  804         return (n);
  805 }
  806 
  807 static struct nd_pfxrouter *
  808 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
  809 {
  810         struct nd_pfxrouter *search;
  811 
  812         for (search = pr->ndpr_advrtrs.lh_first; search; search = search->pfr_next) {
  813                 if (search->router == dr)
  814                         break;
  815         }
  816 
  817         return (search);
  818 }
  819 
  820 static void
  821 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
  822 {
  823         struct nd_pfxrouter *new;
  824 
  825         new = (struct nd_pfxrouter *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
  826         if (new == NULL)
  827                 return;
  828         bzero(new, sizeof(*new));
  829         new->router = dr;
  830 
  831         LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
  832 
  833         pfxlist_onlink_check();
  834 }
  835 
  836 static void
  837 pfxrtr_del(struct nd_pfxrouter *pfr)
  838 {
  839         LIST_REMOVE(pfr, pfr_entry);
  840         free(pfr, M_IP6NDP);
  841 }
  842 
  843 struct nd_prefix *
  844 nd6_prefix_lookup(struct nd_prefixctl *key)
  845 {
  846         struct nd_prefix *search;
  847 
  848         for (search = nd_prefix.lh_first; search; search = search->ndpr_next) {
  849                 if (key->ndpr_ifp == search->ndpr_ifp &&
  850                     key->ndpr_plen == search->ndpr_plen &&
  851                     in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
  852                     &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
  853                         break;
  854                 }
  855         }
  856 
  857         return (search);
  858 }
  859 
  860 int
  861 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
  862     struct nd_prefix **newp)
  863 {
  864         struct nd_prefix *new = NULL;
  865         int error = 0;
  866         int i, s;
  867         char ip6buf[INET6_ADDRSTRLEN];
  868 
  869         new = (struct nd_prefix *)malloc(sizeof(*new), M_IP6NDP, M_NOWAIT);
  870         if (new == NULL)
  871                 return(ENOMEM);
  872         bzero(new, sizeof(*new));
  873         new->ndpr_ifp = pr->ndpr_ifp;
  874         new->ndpr_prefix = pr->ndpr_prefix;
  875         new->ndpr_plen = pr->ndpr_plen;
  876         new->ndpr_vltime = pr->ndpr_vltime;
  877         new->ndpr_pltime = pr->ndpr_pltime;
  878         new->ndpr_flags = pr->ndpr_flags;
  879         if ((error = in6_init_prefix_ltimes(new)) != 0) {
  880                 free(new, M_IP6NDP);
  881                 return(error);
  882         }
  883         new->ndpr_lastupdate = time_second;
  884         if (newp != NULL)
  885                 *newp = new;
  886 
  887         /* initialization */
  888         LIST_INIT(&new->ndpr_advrtrs);
  889         in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
  890         /* make prefix in the canonical form */
  891         for (i = 0; i < 4; i++)
  892                 new->ndpr_prefix.sin6_addr.s6_addr32[i] &=
  893                     new->ndpr_mask.s6_addr32[i];
  894 
  895         s = splnet();
  896         /* link ndpr_entry to nd_prefix list */
  897         LIST_INSERT_HEAD(&nd_prefix, new, ndpr_entry);
  898         splx(s);
  899 
  900         /* ND_OPT_PI_FLAG_ONLINK processing */
  901         if (new->ndpr_raf_onlink) {
  902                 int e;
  903 
  904                 if ((e = nd6_prefix_onlink(new)) != 0) {
  905                         nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
  906                             "the prefix %s/%d on-link on %s (errno=%d)\n",
  907                             ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
  908                             pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
  909                         /* proceed anyway. XXX: is it correct? */
  910                 }
  911         }
  912 
  913         if (dr)
  914                 pfxrtr_add(new, dr);
  915 
  916         return 0;
  917 }
  918 
  919 void
  920 prelist_remove(struct nd_prefix *pr)
  921 {
  922         struct nd_pfxrouter *pfr, *next;
  923         int e, s;
  924         char ip6buf[INET6_ADDRSTRLEN];
  925 
  926         /* make sure to invalidate the prefix until it is really freed. */
  927         pr->ndpr_vltime = 0;
  928         pr->ndpr_pltime = 0;
  929 
  930         /*
  931          * Though these flags are now meaningless, we'd rather keep the value
  932          * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
  933          * when executing "ndp -p".
  934          */
  935 
  936         if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0 &&
  937             (e = nd6_prefix_offlink(pr)) != 0) {
  938                 nd6log((LOG_ERR, "prelist_remove: failed to make %s/%d offlink "
  939                     "on %s, errno=%d\n",
  940                     ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
  941                     pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
  942                 /* what should we do? */
  943         }
  944 
  945         if (pr->ndpr_refcnt > 0)
  946                 return;         /* notice here? */
  947 
  948         s = splnet();
  949 
  950         /* unlink ndpr_entry from nd_prefix list */
  951         LIST_REMOVE(pr, ndpr_entry);
  952 
  953         /* free list of routers that adversed the prefix */
  954         for (pfr = pr->ndpr_advrtrs.lh_first; pfr; pfr = next) {
  955                 next = pfr->pfr_next;
  956 
  957                 free(pfr, M_IP6NDP);
  958         }
  959         splx(s);
  960 
  961         free(pr, M_IP6NDP);
  962 
  963         pfxlist_onlink_check();
  964 }
  965 
  966 /*
  967  * dr - may be NULL
  968  */
  969 
  970 static int
  971 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
  972     struct mbuf *m, int mcast)
  973 {
  974         struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
  975         struct ifaddr *ifa;
  976         struct ifnet *ifp = new->ndpr_ifp;
  977         struct nd_prefix *pr;
  978         int s = splnet();
  979         int error = 0;
  980         int newprefix = 0;
  981         int auth;
  982         struct in6_addrlifetime lt6_tmp;
  983         char ip6buf[INET6_ADDRSTRLEN];
  984 
  985         auth = 0;
  986         if (m) {
  987                 /*
  988                  * Authenticity for NA consists authentication for
  989                  * both IP header and IP datagrams, doesn't it ?
  990                  */
  991 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
  992                 auth = ((m->m_flags & M_AUTHIPHDR) &&
  993                     (m->m_flags & M_AUTHIPDGM));
  994 #endif
  995         }
  996 
  997         if ((pr = nd6_prefix_lookup(new)) != NULL) {
  998                 /*
  999                  * nd6_prefix_lookup() ensures that pr and new have the same
 1000                  * prefix on a same interface.
 1001                  */
 1002 
 1003                 /*
 1004                  * Update prefix information.  Note that the on-link (L) bit
 1005                  * and the autonomous (A) bit should NOT be changed from 1
 1006                  * to 0.
 1007                  */
 1008                 if (new->ndpr_raf_onlink == 1)
 1009                         pr->ndpr_raf_onlink = 1;
 1010                 if (new->ndpr_raf_auto == 1)
 1011                         pr->ndpr_raf_auto = 1;
 1012                 if (new->ndpr_raf_onlink) {
 1013                         pr->ndpr_vltime = new->ndpr_vltime;
 1014                         pr->ndpr_pltime = new->ndpr_pltime;
 1015                         (void)in6_init_prefix_ltimes(pr); /* XXX error case? */
 1016                         pr->ndpr_lastupdate = time_second;
 1017                 }
 1018 
 1019                 if (new->ndpr_raf_onlink &&
 1020                     (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
 1021                         int e;
 1022 
 1023                         if ((e = nd6_prefix_onlink(pr)) != 0) {
 1024                                 nd6log((LOG_ERR,
 1025                                     "prelist_update: failed to make "
 1026                                     "the prefix %s/%d on-link on %s "
 1027                                     "(errno=%d)\n",
 1028                                     ip6_sprintf(ip6buf,
 1029                                             &pr->ndpr_prefix.sin6_addr),
 1030                                     pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
 1031                                 /* proceed anyway. XXX: is it correct? */
 1032                         }
 1033                 }
 1034 
 1035                 if (dr && pfxrtr_lookup(pr, dr) == NULL)
 1036                         pfxrtr_add(pr, dr);
 1037         } else {
 1038                 struct nd_prefix *newpr = NULL;
 1039 
 1040                 newprefix = 1;
 1041 
 1042                 if (new->ndpr_vltime == 0)
 1043                         goto end;
 1044                 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
 1045                         goto end;
 1046 
 1047                 error = nd6_prelist_add(new, dr, &newpr);
 1048                 if (error != 0 || newpr == NULL) {
 1049                         nd6log((LOG_NOTICE, "prelist_update: "
 1050                             "nd6_prelist_add failed for %s/%d on %s "
 1051                             "errno=%d, returnpr=%p\n",
 1052                             ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
 1053                             new->ndpr_plen, if_name(new->ndpr_ifp),
 1054                             error, newpr));
 1055                         goto end; /* we should just give up in this case. */
 1056                 }
 1057 
 1058                 /*
 1059                  * XXX: from the ND point of view, we can ignore a prefix
 1060                  * with the on-link bit being zero.  However, we need a
 1061                  * prefix structure for references from autoconfigured
 1062                  * addresses.  Thus, we explicitly make sure that the prefix
 1063                  * itself expires now.
 1064                  */
 1065                 if (newpr->ndpr_raf_onlink == 0) {
 1066                         newpr->ndpr_vltime = 0;
 1067                         newpr->ndpr_pltime = 0;
 1068                         in6_init_prefix_ltimes(newpr);
 1069                 }
 1070 
 1071                 pr = newpr;
 1072         }
 1073 
 1074         /*
 1075          * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
 1076          * Note that pr must be non NULL at this point.
 1077          */
 1078 
 1079         /* 5.5.3 (a). Ignore the prefix without the A bit set. */
 1080         if (!new->ndpr_raf_auto)
 1081                 goto end;
 1082 
 1083         /*
 1084          * 5.5.3 (b). the link-local prefix should have been ignored in
 1085          * nd6_ra_input.
 1086          */
 1087 
 1088         /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
 1089         if (new->ndpr_pltime > new->ndpr_vltime) {
 1090                 error = EINVAL; /* XXX: won't be used */
 1091                 goto end;
 1092         }
 1093 
 1094         /*
 1095          * 5.5.3 (d).  If the prefix advertised is not equal to the prefix of
 1096          * an address configured by stateless autoconfiguration already in the
 1097          * list of addresses associated with the interface, and the Valid
 1098          * Lifetime is not 0, form an address.  We first check if we have
 1099          * a matching prefix.
 1100          * Note: we apply a clarification in rfc2462bis-02 here.  We only
 1101          * consider autoconfigured addresses while RFC2462 simply said
 1102          * "address".
 1103          */
 1104         TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
 1105                 struct in6_ifaddr *ifa6;
 1106                 u_int32_t remaininglifetime;
 1107 
 1108                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1109                         continue;
 1110 
 1111                 ifa6 = (struct in6_ifaddr *)ifa;
 1112 
 1113                 /*
 1114                  * We only consider autoconfigured addresses as per rfc2462bis.
 1115                  */
 1116                 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
 1117                         continue;
 1118 
 1119                 /*
 1120                  * Spec is not clear here, but I believe we should concentrate
 1121                  * on unicast (i.e. not anycast) addresses.
 1122                  * XXX: other ia6_flags? detached or duplicated?
 1123                  */
 1124                 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
 1125                         continue;
 1126 
 1127                 /*
 1128                  * Ignore the address if it is not associated with a prefix
 1129                  * or is associated with a prefix that is different from this
 1130                  * one.  (pr is never NULL here)
 1131                  */
 1132                 if (ifa6->ia6_ndpr != pr)
 1133                         continue;
 1134 
 1135                 if (ia6_match == NULL) /* remember the first one */
 1136                         ia6_match = ifa6;
 1137 
 1138                 /*
 1139                  * An already autoconfigured address matched.  Now that we
 1140                  * are sure there is at least one matched address, we can
 1141                  * proceed to 5.5.3. (e): update the lifetimes according to the
 1142                  * "two hours" rule and the privacy extension.
 1143                  * We apply some clarifications in rfc2462bis:
 1144                  * - use remaininglifetime instead of storedlifetime as a
 1145                  *   variable name
 1146                  * - remove the dead code in the "two-hour" rule
 1147                  */
 1148 #define TWOHOUR         (120*60)
 1149                 lt6_tmp = ifa6->ia6_lifetime;
 1150 
 1151                 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
 1152                         remaininglifetime = ND6_INFINITE_LIFETIME;
 1153                 else if (time_second - ifa6->ia6_updatetime >
 1154                          lt6_tmp.ia6t_vltime) {
 1155                         /*
 1156                          * The case of "invalid" address.  We should usually
 1157                          * not see this case.
 1158                          */
 1159                         remaininglifetime = 0;
 1160                 } else
 1161                         remaininglifetime = lt6_tmp.ia6t_vltime -
 1162                             (time_second - ifa6->ia6_updatetime);
 1163 
 1164                 /* when not updating, keep the current stored lifetime. */
 1165                 lt6_tmp.ia6t_vltime = remaininglifetime;
 1166 
 1167                 if (TWOHOUR < new->ndpr_vltime ||
 1168                     remaininglifetime < new->ndpr_vltime) {
 1169                         lt6_tmp.ia6t_vltime = new->ndpr_vltime;
 1170                 } else if (remaininglifetime <= TWOHOUR) {
 1171                         if (auth) {
 1172                                 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
 1173                         }
 1174                 } else {
 1175                         /*
 1176                          * new->ndpr_vltime <= TWOHOUR &&
 1177                          * TWOHOUR < remaininglifetime
 1178                          */
 1179                         lt6_tmp.ia6t_vltime = TWOHOUR;
 1180                 }
 1181 
 1182                 /* The 2 hour rule is not imposed for preferred lifetime. */
 1183                 lt6_tmp.ia6t_pltime = new->ndpr_pltime;
 1184 
 1185                 in6_init_address_ltimes(pr, &lt6_tmp);
 1186 
 1187                 /*
 1188                  * We need to treat lifetimes for temporary addresses
 1189                  * differently, according to
 1190                  * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
 1191                  * we only update the lifetimes when they are in the maximum
 1192                  * intervals.
 1193                  */
 1194                 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
 1195                         u_int32_t maxvltime, maxpltime;
 1196 
 1197                         if (ip6_temp_valid_lifetime >
 1198                             (u_int32_t)((time_second - ifa6->ia6_createtime) +
 1199                             ip6_desync_factor)) {
 1200                                 maxvltime = ip6_temp_valid_lifetime -
 1201                                     (time_second - ifa6->ia6_createtime) -
 1202                                     ip6_desync_factor;
 1203                         } else
 1204                                 maxvltime = 0;
 1205                         if (ip6_temp_preferred_lifetime >
 1206                             (u_int32_t)((time_second - ifa6->ia6_createtime) +
 1207                             ip6_desync_factor)) {
 1208                                 maxpltime = ip6_temp_preferred_lifetime -
 1209                                     (time_second - ifa6->ia6_createtime) -
 1210                                     ip6_desync_factor;
 1211                         } else
 1212                                 maxpltime = 0;
 1213 
 1214                         if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
 1215                             lt6_tmp.ia6t_vltime > maxvltime) {
 1216                                 lt6_tmp.ia6t_vltime = maxvltime;
 1217                         }
 1218                         if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
 1219                             lt6_tmp.ia6t_pltime > maxpltime) {
 1220                                 lt6_tmp.ia6t_pltime = maxpltime;
 1221                         }
 1222                 }
 1223                 ifa6->ia6_lifetime = lt6_tmp;
 1224                 ifa6->ia6_updatetime = time_second;
 1225         }
 1226         if (ia6_match == NULL && new->ndpr_vltime) {
 1227                 int ifidlen;
 1228 
 1229                 /*
 1230                  * 5.5.3 (d) (continued)
 1231                  * No address matched and the valid lifetime is non-zero.
 1232                  * Create a new address.
 1233                  */
 1234 
 1235                 /*
 1236                  * Prefix Length check:
 1237                  * If the sum of the prefix length and interface identifier
 1238                  * length does not equal 128 bits, the Prefix Information
 1239                  * option MUST be ignored.  The length of the interface
 1240                  * identifier is defined in a separate link-type specific
 1241                  * document.
 1242                  */
 1243                 ifidlen = in6_if2idlen(ifp);
 1244                 if (ifidlen < 0) {
 1245                         /* this should not happen, so we always log it. */
 1246                         log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
 1247                             if_name(ifp));
 1248                         goto end;
 1249                 }
 1250                 if (ifidlen + pr->ndpr_plen != 128) {
 1251                         nd6log((LOG_INFO,
 1252                             "prelist_update: invalid prefixlen "
 1253                             "%d for %s, ignored\n",
 1254                             pr->ndpr_plen, if_name(ifp)));
 1255                         goto end;
 1256                 }
 1257 
 1258                 if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
 1259                         /*
 1260                          * note that we should use pr (not new) for reference.
 1261                          */
 1262                         pr->ndpr_refcnt++;
 1263                         ia6->ia6_ndpr = pr;
 1264 
 1265                         /*
 1266                          * RFC 3041 3.3 (2).
 1267                          * When a new public address is created as described
 1268                          * in RFC2462, also create a new temporary address.
 1269                          *
 1270                          * RFC 3041 3.5.
 1271                          * When an interface connects to a new link, a new
 1272                          * randomized interface identifier should be generated
 1273                          * immediately together with a new set of temporary
 1274                          * addresses.  Thus, we specifiy 1 as the 2nd arg of
 1275                          * in6_tmpifadd().
 1276                          */
 1277                         if (ip6_use_tempaddr) {
 1278                                 int e;
 1279                                 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
 1280                                         nd6log((LOG_NOTICE, "prelist_update: "
 1281                                             "failed to create a temporary "
 1282                                             "address, errno=%d\n",
 1283                                             e));
 1284                                 }
 1285                         }
 1286 
 1287                         /*
 1288                          * A newly added address might affect the status
 1289                          * of other addresses, so we check and update it.
 1290                          * XXX: what if address duplication happens?
 1291                          */
 1292                         pfxlist_onlink_check();
 1293                 } else {
 1294                         /* just set an error. do not bark here. */
 1295                         error = EADDRNOTAVAIL; /* XXX: might be unused. */
 1296                 }
 1297         }
 1298 
 1299  end:
 1300         splx(s);
 1301         return error;
 1302 }
 1303 
 1304 /*
 1305  * A supplement function used in the on-link detection below;
 1306  * detect if a given prefix has a (probably) reachable advertising router.
 1307  * XXX: lengthy function name...
 1308  */
 1309 static struct nd_pfxrouter *
 1310 find_pfxlist_reachable_router(struct nd_prefix *pr)
 1311 {
 1312         struct nd_pfxrouter *pfxrtr;
 1313         struct rtentry *rt;
 1314         struct llinfo_nd6 *ln;
 1315 
 1316         for (pfxrtr = LIST_FIRST(&pr->ndpr_advrtrs); pfxrtr;
 1317              pfxrtr = LIST_NEXT(pfxrtr, pfr_entry)) {
 1318                 if ((rt = nd6_lookup(&pfxrtr->router->rtaddr, 0,
 1319                     pfxrtr->router->ifp)) &&
 1320                     (ln = (struct llinfo_nd6 *)rt->rt_llinfo) &&
 1321                     ND6_IS_LLINFO_PROBREACH(ln))
 1322                         break;  /* found */
 1323         }
 1324 
 1325         return (pfxrtr);
 1326 }
 1327 
 1328 /*
 1329  * Check if each prefix in the prefix list has at least one available router
 1330  * that advertised the prefix (a router is "available" if its neighbor cache
 1331  * entry is reachable or probably reachable).
 1332  * If the check fails, the prefix may be off-link, because, for example,
 1333  * we have moved from the network but the lifetime of the prefix has not
 1334  * expired yet.  So we should not use the prefix if there is another prefix
 1335  * that has an available router.
 1336  * But, if there is no prefix that has an available router, we still regards
 1337  * all the prefixes as on-link.  This is because we can't tell if all the
 1338  * routers are simply dead or if we really moved from the network and there
 1339  * is no router around us.
 1340  */
 1341 void
 1342 pfxlist_onlink_check()
 1343 {
 1344         struct nd_prefix *pr;
 1345         struct in6_ifaddr *ifa;
 1346         struct nd_defrouter *dr;
 1347         struct nd_pfxrouter *pfxrtr = NULL;
 1348 
 1349         /*
 1350          * Check if there is a prefix that has a reachable advertising
 1351          * router.
 1352          */
 1353         for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1354                 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
 1355                         break;
 1356         }
 1357 
 1358         /*
 1359          * If we have no such prefix, check whether we still have a router
 1360          * that does not advertise any prefixes.
 1361          */
 1362         if (pr == NULL) {
 1363                 for (dr = TAILQ_FIRST(&nd_defrouter); dr;
 1364                     dr = TAILQ_NEXT(dr, dr_entry)) {
 1365                         struct nd_prefix *pr0;
 1366 
 1367                         for (pr0 = nd_prefix.lh_first; pr0;
 1368                             pr0 = pr0->ndpr_next) {
 1369                                 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
 1370                                         break;
 1371                         }
 1372                         if (pfxrtr != NULL)
 1373                                 break;
 1374                 }
 1375         }
 1376         if (pr != NULL || (TAILQ_FIRST(&nd_defrouter) && pfxrtr == NULL)) {
 1377                 /*
 1378                  * There is at least one prefix that has a reachable router,
 1379                  * or at least a router which probably does not advertise
 1380                  * any prefixes.  The latter would be the case when we move
 1381                  * to a new link where we have a router that does not provide
 1382                  * prefixes and we configure an address by hand.
 1383                  * Detach prefixes which have no reachable advertising
 1384                  * router, and attach other prefixes.
 1385                  */
 1386                 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1387                         /* XXX: a link-local prefix should never be detached */
 1388                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1389                                 continue;
 1390 
 1391                         /*
 1392                          * we aren't interested in prefixes without the L bit
 1393                          * set.
 1394                          */
 1395                         if (pr->ndpr_raf_onlink == 0)
 1396                                 continue;
 1397 
 1398                         if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
 1399                             find_pfxlist_reachable_router(pr) == NULL)
 1400                                 pr->ndpr_stateflags |= NDPRF_DETACHED;
 1401                         if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
 1402                             find_pfxlist_reachable_router(pr) != 0)
 1403                                 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
 1404                 }
 1405         } else {
 1406                 /* there is no prefix that has a reachable router */
 1407                 for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1408                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1409                                 continue;
 1410 
 1411                         if (pr->ndpr_raf_onlink == 0)
 1412                                 continue;
 1413 
 1414                         if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0)
 1415                                 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
 1416                 }
 1417         }
 1418 
 1419         /*
 1420          * Remove each interface route associated with a (just) detached
 1421          * prefix, and reinstall the interface route for a (just) attached
 1422          * prefix.  Note that all attempt of reinstallation does not
 1423          * necessarily success, when a same prefix is shared among multiple
 1424          * interfaces.  Such cases will be handled in nd6_prefix_onlink,
 1425          * so we don't have to care about them.
 1426          */
 1427         for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
 1428                 int e;
 1429                 char ip6buf[INET6_ADDRSTRLEN];
 1430 
 1431                 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1432                         continue;
 1433 
 1434                 if (pr->ndpr_raf_onlink == 0)
 1435                         continue;
 1436 
 1437                 if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
 1438                     (pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 1439                         if ((e = nd6_prefix_offlink(pr)) != 0) {
 1440                                 nd6log((LOG_ERR,
 1441                                     "pfxlist_onlink_check: failed to "
 1442                                     "make %s/%d offlink, errno=%d\n",
 1443                                     ip6_sprintf(ip6buf,
 1444                                             &pr->ndpr_prefix.sin6_addr),
 1445                                             pr->ndpr_plen, e));
 1446                         }
 1447                 }
 1448                 if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
 1449                     (pr->ndpr_stateflags & NDPRF_ONLINK) == 0 &&
 1450                     pr->ndpr_raf_onlink) {
 1451                         if ((e = nd6_prefix_onlink(pr)) != 0) {
 1452                                 nd6log((LOG_ERR,
 1453                                     "pfxlist_onlink_check: failed to "
 1454                                     "make %s/%d onlink, errno=%d\n",
 1455                                     ip6_sprintf(ip6buf,
 1456                                             &pr->ndpr_prefix.sin6_addr),
 1457                                             pr->ndpr_plen, e));
 1458                         }
 1459                 }
 1460         }
 1461 
 1462         /*
 1463          * Changes on the prefix status might affect address status as well.
 1464          * Make sure that all addresses derived from an attached prefix are
 1465          * attached, and that all addresses derived from a detached prefix are
 1466          * detached.  Note, however, that a manually configured address should
 1467          * always be attached.
 1468          * The precise detection logic is same as the one for prefixes.
 1469          */
 1470         for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
 1471                 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
 1472                         continue;
 1473 
 1474                 if (ifa->ia6_ndpr == NULL) {
 1475                         /*
 1476                          * This can happen when we first configure the address
 1477                          * (i.e. the address exists, but the prefix does not).
 1478                          * XXX: complicated relationships...
 1479                          */
 1480                         continue;
 1481                 }
 1482 
 1483                 if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
 1484                         break;
 1485         }
 1486         if (ifa) {
 1487                 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
 1488                         if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1489                                 continue;
 1490 
 1491                         if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
 1492                                 continue;
 1493 
 1494                         if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
 1495                                 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
 1496                                         ifa->ia6_flags &= ~IN6_IFF_DETACHED;
 1497                                         ifa->ia6_flags |= IN6_IFF_TENTATIVE;
 1498                                         nd6_dad_start((struct ifaddr *)ifa, 0);
 1499                                 }
 1500                         } else {
 1501                                 ifa->ia6_flags |= IN6_IFF_DETACHED;
 1502                         }
 1503                 }
 1504         }
 1505         else {
 1506                 for (ifa = in6_ifaddr; ifa; ifa = ifa->ia_next) {
 1507                         if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1508                                 continue;
 1509 
 1510                         if (ifa->ia6_flags & IN6_IFF_DETACHED) {
 1511                                 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
 1512                                 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
 1513                                 /* Do we need a delay in this case? */
 1514                                 nd6_dad_start((struct ifaddr *)ifa, 0);
 1515                         }
 1516                 }
 1517         }
 1518 }
 1519 
 1520 int
 1521 nd6_prefix_onlink(struct nd_prefix *pr)
 1522 {
 1523         struct ifaddr *ifa;
 1524         struct ifnet *ifp = pr->ndpr_ifp;
 1525         struct sockaddr_in6 mask6;
 1526         struct nd_prefix *opr;
 1527         u_long rtflags;
 1528         int error = 0;
 1529         struct rtentry *rt = NULL;
 1530         char ip6buf[INET6_ADDRSTRLEN];
 1531 
 1532         /* sanity check */
 1533         if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 1534                 nd6log((LOG_ERR,
 1535                     "nd6_prefix_onlink: %s/%d is already on-link\n",
 1536                     ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1537                     pr->ndpr_plen));
 1538                 return (EEXIST);
 1539         }
 1540 
 1541         /*
 1542          * Add the interface route associated with the prefix.  Before
 1543          * installing the route, check if there's the same prefix on another
 1544          * interface, and the prefix has already installed the interface route.
 1545          * Although such a configuration is expected to be rare, we explicitly
 1546          * allow it.
 1547          */
 1548         for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
 1549                 if (opr == pr)
 1550                         continue;
 1551 
 1552                 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
 1553                         continue;
 1554 
 1555                 if (opr->ndpr_plen == pr->ndpr_plen &&
 1556                     in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
 1557                     &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen))
 1558                         return (0);
 1559         }
 1560 
 1561         /*
 1562          * We prefer link-local addresses as the associated interface address.
 1563          */
 1564         /* search for a link-local addr */
 1565         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
 1566             IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
 1567         if (ifa == NULL) {
 1568                 /* XXX: freebsd does not have ifa_ifwithaf */
 1569                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
 1570                         if (ifa->ifa_addr->sa_family == AF_INET6)
 1571                                 break;
 1572                 }
 1573                 /* should we care about ia6_flags? */
 1574         }
 1575         if (ifa == NULL) {
 1576                 /*
 1577                  * This can still happen, when, for example, we receive an RA
 1578                  * containing a prefix with the L bit set and the A bit clear,
 1579                  * after removing all IPv6 addresses on the receiving
 1580                  * interface.  This should, of course, be rare though.
 1581                  */
 1582                 nd6log((LOG_NOTICE,
 1583                     "nd6_prefix_onlink: failed to find any ifaddr"
 1584                     " to add route for a prefix(%s/%d) on %s\n",
 1585                     ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1586                     pr->ndpr_plen, if_name(ifp)));
 1587                 return (0);
 1588         }
 1589 
 1590         /*
 1591          * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
 1592          * ifa->ifa_rtrequest = nd6_rtrequest;
 1593          */
 1594         bzero(&mask6, sizeof(mask6));
 1595         mask6.sin6_len = sizeof(mask6);
 1596         mask6.sin6_addr = pr->ndpr_mask;
 1597         rtflags = ifa->ifa_flags | RTF_CLONING | RTF_UP;
 1598         if (nd6_need_cache(ifp)) {
 1599                 /* explicitly set in case ifa_flags does not set the flag. */
 1600                 rtflags |= RTF_CLONING;
 1601         } else {
 1602                 /*
 1603                  * explicitly clear the cloning bit in case ifa_flags sets it.
 1604                  */
 1605                 rtflags &= ~RTF_CLONING;
 1606         }
 1607         error = rtrequest(RTM_ADD, (struct sockaddr *)&pr->ndpr_prefix,
 1608             ifa->ifa_addr, (struct sockaddr *)&mask6, rtflags, &rt);
 1609         if (error == 0) {
 1610                 if (rt != NULL) /* this should be non NULL, though */
 1611                         nd6_rtmsg(RTM_ADD, rt);
 1612                 pr->ndpr_stateflags |= NDPRF_ONLINK;
 1613         } else {
 1614                 char ip6bufg[INET6_ADDRSTRLEN], ip6bufm[INET6_ADDRSTRLEN];
 1615                 nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add route for a"
 1616                     " prefix (%s/%d) on %s, gw=%s, mask=%s, flags=%lx "
 1617                     "errno = %d\n",
 1618                     ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1619                     pr->ndpr_plen, if_name(ifp),
 1620                     ip6_sprintf(ip6bufg, &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr),
 1621                     ip6_sprintf(ip6bufm, &mask6.sin6_addr), rtflags, error));
 1622         }
 1623 
 1624         if (rt != NULL) {
 1625                 RT_LOCK(rt);
 1626                 RT_REMREF(rt);
 1627                 RT_UNLOCK(rt);
 1628         }
 1629 
 1630         return (error);
 1631 }
 1632 
 1633 int
 1634 nd6_prefix_offlink(struct nd_prefix *pr)
 1635 {
 1636         int error = 0;
 1637         struct ifnet *ifp = pr->ndpr_ifp;
 1638         struct nd_prefix *opr;
 1639         struct sockaddr_in6 sa6, mask6;
 1640         struct rtentry *rt = NULL;
 1641         char ip6buf[INET6_ADDRSTRLEN];
 1642 
 1643         /* sanity check */
 1644         if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
 1645                 nd6log((LOG_ERR,
 1646                     "nd6_prefix_offlink: %s/%d is already off-link\n",
 1647                     ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1648                     pr->ndpr_plen));
 1649                 return (EEXIST);
 1650         }
 1651 
 1652         bzero(&sa6, sizeof(sa6));
 1653         sa6.sin6_family = AF_INET6;
 1654         sa6.sin6_len = sizeof(sa6);
 1655         bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
 1656             sizeof(struct in6_addr));
 1657         bzero(&mask6, sizeof(mask6));
 1658         mask6.sin6_family = AF_INET6;
 1659         mask6.sin6_len = sizeof(sa6);
 1660         bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
 1661         error = rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
 1662             (struct sockaddr *)&mask6, 0, &rt);
 1663         if (error == 0) {
 1664                 pr->ndpr_stateflags &= ~NDPRF_ONLINK;
 1665 
 1666                 /* report the route deletion to the routing socket. */
 1667                 if (rt != NULL)
 1668                         nd6_rtmsg(RTM_DELETE, rt);
 1669 
 1670                 /*
 1671                  * There might be the same prefix on another interface,
 1672                  * the prefix which could not be on-link just because we have
 1673                  * the interface route (see comments in nd6_prefix_onlink).
 1674                  * If there's one, try to make the prefix on-link on the
 1675                  * interface.
 1676                  */
 1677                 for (opr = nd_prefix.lh_first; opr; opr = opr->ndpr_next) {
 1678                         if (opr == pr)
 1679                                 continue;
 1680 
 1681                         if ((opr->ndpr_stateflags & NDPRF_ONLINK) != 0)
 1682                                 continue;
 1683 
 1684                         /*
 1685                          * KAME specific: detached prefixes should not be
 1686                          * on-link.
 1687                          */
 1688                         if ((opr->ndpr_stateflags & NDPRF_DETACHED) != 0)
 1689                                 continue;
 1690 
 1691                         if (opr->ndpr_plen == pr->ndpr_plen &&
 1692                             in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
 1693                             &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
 1694                                 int e;
 1695 
 1696                                 if ((e = nd6_prefix_onlink(opr)) != 0) {
 1697                                         nd6log((LOG_ERR,
 1698                                             "nd6_prefix_offlink: failed to "
 1699                                             "recover a prefix %s/%d from %s "
 1700                                             "to %s (errno = %d)\n",
 1701                                             ip6_sprintf(ip6buf,
 1702                                                 &opr->ndpr_prefix.sin6_addr),
 1703                                             opr->ndpr_plen, if_name(ifp),
 1704                                             if_name(opr->ndpr_ifp), e));
 1705                                 }
 1706                         }
 1707                 }
 1708         } else {
 1709                 /* XXX: can we still set the NDPRF_ONLINK flag? */
 1710                 nd6log((LOG_ERR,
 1711                     "nd6_prefix_offlink: failed to delete route: "
 1712                     "%s/%d on %s (errno = %d)\n",
 1713                     ip6_sprintf(ip6buf, &sa6.sin6_addr), pr->ndpr_plen,
 1714                     if_name(ifp), error));
 1715         }
 1716 
 1717         if (rt != NULL) {
 1718                 RTFREE(rt);
 1719         }
 1720 
 1721         return (error);
 1722 }
 1723 
 1724 static struct in6_ifaddr *
 1725 in6_ifadd(struct nd_prefixctl *pr, int mcast)
 1726 {
 1727         struct ifnet *ifp = pr->ndpr_ifp;
 1728         struct ifaddr *ifa;
 1729         struct in6_aliasreq ifra;
 1730         struct in6_ifaddr *ia, *ib;
 1731         int error, plen0;
 1732         struct in6_addr mask;
 1733         int prefixlen = pr->ndpr_plen;
 1734         int updateflags;
 1735         char ip6buf[INET6_ADDRSTRLEN];
 1736 
 1737         in6_prefixlen2mask(&mask, prefixlen);
 1738 
 1739         /*
 1740          * find a link-local address (will be interface ID).
 1741          * Is it really mandatory? Theoretically, a global or a site-local
 1742          * address can be configured without a link-local address, if we
 1743          * have a unique interface identifier...
 1744          *
 1745          * it is not mandatory to have a link-local address, we can generate
 1746          * interface identifier on the fly.  we do this because:
 1747          * (1) it should be the easiest way to find interface identifier.
 1748          * (2) RFC2462 5.4 suggesting the use of the same interface identifier
 1749          * for multiple addresses on a single interface, and possible shortcut
 1750          * of DAD.  we omitted DAD for this reason in the past.
 1751          * (3) a user can prevent autoconfiguration of global address
 1752          * by removing link-local address by hand (this is partly because we
 1753          * don't have other way to control the use of IPv6 on an interface.
 1754          * this has been our design choice - cf. NRL's "ifconfig auto").
 1755          * (4) it is easier to manage when an interface has addresses
 1756          * with the same interface identifier, than to have multiple addresses
 1757          * with different interface identifiers.
 1758          */
 1759         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
 1760         if (ifa)
 1761                 ib = (struct in6_ifaddr *)ifa;
 1762         else
 1763                 return NULL;
 1764 
 1765         /* prefixlen + ifidlen must be equal to 128 */
 1766         plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
 1767         if (prefixlen != plen0) {
 1768                 nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
 1769                     "(prefix=%d ifid=%d)\n",
 1770                     if_name(ifp), prefixlen, 128 - plen0));
 1771                 return NULL;
 1772         }
 1773 
 1774         /* make ifaddr */
 1775 
 1776         bzero(&ifra, sizeof(ifra));
 1777         /*
 1778          * in6_update_ifa() does not use ifra_name, but we accurately set it
 1779          * for safety.
 1780          */
 1781         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
 1782         ifra.ifra_addr.sin6_family = AF_INET6;
 1783         ifra.ifra_addr.sin6_len = sizeof(struct sockaddr_in6);
 1784         /* prefix */
 1785         ifra.ifra_addr.sin6_addr = pr->ndpr_prefix.sin6_addr;
 1786         ifra.ifra_addr.sin6_addr.s6_addr32[0] &= mask.s6_addr32[0];
 1787         ifra.ifra_addr.sin6_addr.s6_addr32[1] &= mask.s6_addr32[1];
 1788         ifra.ifra_addr.sin6_addr.s6_addr32[2] &= mask.s6_addr32[2];
 1789         ifra.ifra_addr.sin6_addr.s6_addr32[3] &= mask.s6_addr32[3];
 1790 
 1791         /* interface ID */
 1792         ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
 1793             (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
 1794         ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
 1795             (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
 1796         ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
 1797             (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
 1798         ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
 1799             (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
 1800 
 1801         /* new prefix mask. */
 1802         ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
 1803         ifra.ifra_prefixmask.sin6_family = AF_INET6;
 1804         bcopy(&mask, &ifra.ifra_prefixmask.sin6_addr,
 1805             sizeof(ifra.ifra_prefixmask.sin6_addr));
 1806 
 1807         /* lifetimes. */
 1808         ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
 1809         ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
 1810 
 1811         /* XXX: scope zone ID? */
 1812 
 1813         ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
 1814 
 1815         /*
 1816          * Make sure that we do not have this address already.  This should
 1817          * usually not happen, but we can still see this case, e.g., if we
 1818          * have manually configured the exact address to be configured.
 1819          */
 1820         if (in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr) != NULL) {
 1821                 /* this should be rare enough to make an explicit log */
 1822                 log(LOG_INFO, "in6_ifadd: %s is already configured\n",
 1823                     ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
 1824                 return (NULL);
 1825         }
 1826 
 1827         /*
 1828          * Allocate ifaddr structure, link into chain, etc.
 1829          * If we are going to create a new address upon receiving a multicasted
 1830          * RA, we need to impose a random delay before starting DAD.
 1831          * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
 1832          */
 1833         updateflags = 0;
 1834         if (mcast)
 1835                 updateflags |= IN6_IFAUPDATE_DADDELAY;
 1836         if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
 1837                 nd6log((LOG_ERR,
 1838                     "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
 1839                     ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr),
 1840                     if_name(ifp), error));
 1841                 return (NULL);  /* ifaddr must not have been allocated. */
 1842         }
 1843 
 1844         ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
 1845 
 1846         return (ia);            /* this is always non-NULL */
 1847 }
 1848 
 1849 /*
 1850  * ia0 - corresponding public address
 1851  */
 1852 int
 1853 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
 1854 {
 1855         struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
 1856         struct in6_ifaddr *newia, *ia;
 1857         struct in6_aliasreq ifra;
 1858         int i, error;
 1859         int trylimit = 3;       /* XXX: adhoc value */
 1860         int updateflags;
 1861         u_int32_t randid[2];
 1862         time_t vltime0, pltime0;
 1863 
 1864         bzero(&ifra, sizeof(ifra));
 1865         strncpy(ifra.ifra_name, if_name(ifp), sizeof(ifra.ifra_name));
 1866         ifra.ifra_addr = ia0->ia_addr;
 1867         /* copy prefix mask */
 1868         ifra.ifra_prefixmask = ia0->ia_prefixmask;
 1869         /* clear the old IFID */
 1870         for (i = 0; i < 4; i++) {
 1871                 ifra.ifra_addr.sin6_addr.s6_addr32[i] &=
 1872                     ifra.ifra_prefixmask.sin6_addr.s6_addr32[i];
 1873         }
 1874 
 1875   again:
 1876         if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
 1877             (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
 1878                 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
 1879                     "random IFID\n"));
 1880                 return (EINVAL);
 1881         }
 1882         ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
 1883             (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
 1884         ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
 1885             (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
 1886 
 1887         /*
 1888          * in6_get_tmpifid() quite likely provided a unique interface ID.
 1889          * However, we may still have a chance to see collision, because
 1890          * there may be a time lag between generation of the ID and generation
 1891          * of the address.  So, we'll do one more sanity check.
 1892          */
 1893         for (ia = in6_ifaddr; ia; ia = ia->ia_next) {
 1894                 if (IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
 1895                     &ifra.ifra_addr.sin6_addr)) {
 1896                         if (trylimit-- == 0) {
 1897                                 /*
 1898                                  * Give up.  Something strange should have
 1899                                  * happened.
 1900                                  */
 1901                                 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
 1902                                     "find a unique random IFID\n"));
 1903                                 return (EEXIST);
 1904                         }
 1905                         forcegen = 1;
 1906                         goto again;
 1907                 }
 1908         }
 1909 
 1910         /*
 1911          * The Valid Lifetime is the lower of the Valid Lifetime of the
 1912          * public address or TEMP_VALID_LIFETIME.
 1913          * The Preferred Lifetime is the lower of the Preferred Lifetime
 1914          * of the public address or TEMP_PREFERRED_LIFETIME -
 1915          * DESYNC_FACTOR.
 1916          */
 1917         if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
 1918                 vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
 1919                     (ia0->ia6_lifetime.ia6t_vltime -
 1920                     (time_second - ia0->ia6_updatetime));
 1921                 if (vltime0 > ip6_temp_valid_lifetime)
 1922                         vltime0 = ip6_temp_valid_lifetime;
 1923         } else
 1924                 vltime0 = ip6_temp_valid_lifetime;
 1925         if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
 1926                 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
 1927                     (ia0->ia6_lifetime.ia6t_pltime -
 1928                     (time_second - ia0->ia6_updatetime));
 1929                 if (pltime0 > ip6_temp_preferred_lifetime - ip6_desync_factor){
 1930                         pltime0 = ip6_temp_preferred_lifetime -
 1931                             ip6_desync_factor;
 1932                 }
 1933         } else
 1934                 pltime0 = ip6_temp_preferred_lifetime - ip6_desync_factor;
 1935         ifra.ifra_lifetime.ia6t_vltime = vltime0;
 1936         ifra.ifra_lifetime.ia6t_pltime = pltime0;
 1937 
 1938         /*
 1939          * A temporary address is created only if this calculated Preferred
 1940          * Lifetime is greater than REGEN_ADVANCE time units.
 1941          */
 1942         if (ifra.ifra_lifetime.ia6t_pltime <= ip6_temp_regen_advance)
 1943                 return (0);
 1944 
 1945         /* XXX: scope zone ID? */
 1946 
 1947         ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
 1948 
 1949         /* allocate ifaddr structure, link into chain, etc. */
 1950         updateflags = 0;
 1951         if (delay)
 1952                 updateflags |= IN6_IFAUPDATE_DADDELAY;
 1953         if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
 1954                 return (error);
 1955 
 1956         newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
 1957         if (newia == NULL) {    /* XXX: can it happen? */
 1958                 nd6log((LOG_ERR,
 1959                     "in6_tmpifadd: ifa update succeeded, but we got "
 1960                     "no ifaddr\n"));
 1961                 return (EINVAL); /* XXX */
 1962         }
 1963         newia->ia6_ndpr = ia0->ia6_ndpr;
 1964         newia->ia6_ndpr->ndpr_refcnt++;
 1965 
 1966         /*
 1967          * A newly added address might affect the status of other addresses.
 1968          * XXX: when the temporary address is generated with a new public
 1969          * address, the onlink check is redundant.  However, it would be safe
 1970          * to do the check explicitly everywhere a new address is generated,
 1971          * and, in fact, we surely need the check when we create a new
 1972          * temporary address due to deprecation of an old temporary address.
 1973          */
 1974         pfxlist_onlink_check();
 1975 
 1976         return (0);
 1977 }
 1978 
 1979 static int
 1980 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
 1981 {
 1982         if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
 1983                 ndpr->ndpr_preferred = 0;
 1984         else
 1985                 ndpr->ndpr_preferred = time_second + ndpr->ndpr_pltime;
 1986         if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
 1987                 ndpr->ndpr_expire = 0;
 1988         else
 1989                 ndpr->ndpr_expire = time_second + ndpr->ndpr_vltime;
 1990 
 1991         return 0;
 1992 }
 1993 
 1994 static void
 1995 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
 1996 {
 1997         /* init ia6t_expire */
 1998         if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
 1999                 lt6->ia6t_expire = 0;
 2000         else {
 2001                 lt6->ia6t_expire = time_second;
 2002                 lt6->ia6t_expire += lt6->ia6t_vltime;
 2003         }
 2004 
 2005         /* init ia6t_preferred */
 2006         if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
 2007                 lt6->ia6t_preferred = 0;
 2008         else {
 2009                 lt6->ia6t_preferred = time_second;
 2010                 lt6->ia6t_preferred += lt6->ia6t_pltime;
 2011         }
 2012 }
 2013 
 2014 /*
 2015  * Delete all the routing table entries that use the specified gateway.
 2016  * XXX: this function causes search through all entries of routing table, so
 2017  * it shouldn't be called when acting as a router.
 2018  */
 2019 void
 2020 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
 2021 {
 2022 
 2023         struct radix_node_head *rnh = rt_tables[0][AF_INET6];
 2024         int s = splnet();
 2025 
 2026         /* We'll care only link-local addresses */
 2027         if (!IN6_IS_ADDR_LINKLOCAL(gateway)) {
 2028                 splx(s);
 2029                 return;
 2030         }
 2031 
 2032         RADIX_NODE_HEAD_LOCK(rnh);
 2033         rnh->rnh_walktree(rnh, rt6_deleteroute, (void *)gateway);
 2034         RADIX_NODE_HEAD_UNLOCK(rnh);
 2035         splx(s);
 2036 }
 2037 
 2038 static int
 2039 rt6_deleteroute(struct radix_node *rn, void *arg)
 2040 {
 2041 #define SIN6(s) ((struct sockaddr_in6 *)s)
 2042         struct rtentry *rt = (struct rtentry *)rn;
 2043         struct in6_addr *gate = (struct in6_addr *)arg;
 2044 
 2045         if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
 2046                 return (0);
 2047 
 2048         if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) {
 2049                 return (0);
 2050         }
 2051 
 2052         /*
 2053          * Do not delete a static route.
 2054          * XXX: this seems to be a bit ad-hoc. Should we consider the
 2055          * 'cloned' bit instead?
 2056          */
 2057         if ((rt->rt_flags & RTF_STATIC) != 0)
 2058                 return (0);
 2059 
 2060         /*
 2061          * We delete only host route. This means, in particular, we don't
 2062          * delete default route.
 2063          */
 2064         if ((rt->rt_flags & RTF_HOST) == 0)
 2065                 return (0);
 2066 
 2067         return (rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
 2068             rt_mask(rt), rt->rt_flags, 0));
 2069 #undef SIN6
 2070 }
 2071 
 2072 int
 2073 nd6_setdefaultiface(int ifindex)
 2074 {
 2075         int error = 0;
 2076 
 2077         if (ifindex < 0 || if_index < ifindex)
 2078                 return (EINVAL);
 2079         if (ifindex != 0 && !ifnet_byindex(ifindex))
 2080                 return (EINVAL);
 2081 
 2082         if (nd6_defifindex != ifindex) {
 2083                 nd6_defifindex = ifindex;
 2084                 if (nd6_defifindex > 0)
 2085                         nd6_defifp = ifnet_byindex(nd6_defifindex);
 2086                 else
 2087                         nd6_defifp = NULL;
 2088 
 2089                 /*
 2090                  * Our current implementation assumes one-to-one maping between
 2091                  * interfaces and links, so it would be natural to use the
 2092                  * default interface as the default link.
 2093                  */
 2094                 scope6_setdefault(nd6_defifp);
 2095         }
 2096 
 2097         return (error);
 2098 }

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