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/11.1/sys/netinet6/nd6_rtr.c 317067 2017-04-17 20:13:20Z asomers $");
   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/refcount.h>
   43 #include <sys/socket.h>
   44 #include <sys/sockio.h>
   45 #include <sys/time.h>
   46 #include <sys/kernel.h>
   47 #include <sys/lock.h>
   48 #include <sys/errno.h>
   49 #include <sys/rmlock.h>
   50 #include <sys/rwlock.h>
   51 #include <sys/syslog.h>
   52 #include <sys/queue.h>
   53 
   54 #include <net/if.h>
   55 #include <net/if_var.h>
   56 #include <net/if_types.h>
   57 #include <net/if_dl.h>
   58 #include <net/route.h>
   59 #include <net/route_var.h>
   60 #include <net/radix.h>
   61 #include <net/vnet.h>
   62 
   63 #include <netinet/in.h>
   64 #include <net/if_llatbl.h>
   65 #include <netinet6/in6_var.h>
   66 #include <netinet6/in6_ifattach.h>
   67 #include <netinet/ip6.h>
   68 #include <netinet6/ip6_var.h>
   69 #include <netinet6/nd6.h>
   70 #include <netinet/icmp6.h>
   71 #include <netinet6/scope6_var.h>
   72 
   73 static int rtpref(struct nd_defrouter *);
   74 static struct nd_defrouter *defrtrlist_update(struct nd_defrouter *);
   75 static int prelist_update(struct nd_prefixctl *, struct nd_defrouter *,
   76     struct mbuf *, int);
   77 static struct in6_ifaddr *in6_ifadd(struct nd_prefixctl *, int);
   78 static struct nd_pfxrouter *pfxrtr_lookup(struct nd_prefix *,
   79     struct nd_defrouter *);
   80 static void pfxrtr_add(struct nd_prefix *, struct nd_defrouter *);
   81 static void pfxrtr_del(struct nd_pfxrouter *);
   82 static struct nd_pfxrouter *find_pfxlist_reachable_router(struct nd_prefix *);
   83 static void defrouter_delreq(struct nd_defrouter *);
   84 static void nd6_rtmsg(int, struct rtentry *);
   85 
   86 static int in6_init_prefix_ltimes(struct nd_prefix *);
   87 static void in6_init_address_ltimes(struct nd_prefix *,
   88     struct in6_addrlifetime *);
   89 
   90 static int rt6_deleteroute(const struct rtentry *, void *);
   91 
   92 VNET_DECLARE(int, nd6_recalc_reachtm_interval);
   93 #define V_nd6_recalc_reachtm_interval   VNET(nd6_recalc_reachtm_interval)
   94 
   95 static VNET_DEFINE(struct ifnet *, nd6_defifp);
   96 VNET_DEFINE(int, nd6_defifindex);
   97 #define V_nd6_defifp                    VNET(nd6_defifp)
   98 
   99 VNET_DEFINE(int, ip6_use_tempaddr) = 0;
  100 
  101 VNET_DEFINE(int, ip6_desync_factor);
  102 VNET_DEFINE(u_int32_t, ip6_temp_preferred_lifetime) = DEF_TEMP_PREFERRED_LIFETIME;
  103 VNET_DEFINE(u_int32_t, ip6_temp_valid_lifetime) = DEF_TEMP_VALID_LIFETIME;
  104 
  105 VNET_DEFINE(int, ip6_temp_regen_advance) = TEMPADDR_REGEN_ADVANCE;
  106 
  107 /* RTPREF_MEDIUM has to be 0! */
  108 #define RTPREF_HIGH     1
  109 #define RTPREF_MEDIUM   0
  110 #define RTPREF_LOW      (-1)
  111 #define RTPREF_RESERVED (-2)
  112 #define RTPREF_INVALID  (-3)    /* internal */
  113 
  114 /*
  115  * Receive Router Solicitation Message - just for routers.
  116  * Router solicitation/advertisement is mostly managed by userland program
  117  * (rtadvd) so here we have no function like nd6_ra_output().
  118  *
  119  * Based on RFC 2461
  120  */
  121 void
  122 nd6_rs_input(struct mbuf *m, int off, int icmp6len)
  123 {
  124         struct ifnet *ifp = m->m_pkthdr.rcvif;
  125         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  126         struct nd_router_solicit *nd_rs;
  127         struct in6_addr saddr6 = ip6->ip6_src;
  128         char *lladdr = NULL;
  129         int lladdrlen = 0;
  130         union nd_opts ndopts;
  131         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  132 
  133         /*
  134          * Accept RS only when V_ip6_forwarding=1 and the interface has
  135          * no ND6_IFF_ACCEPT_RTADV.
  136          */
  137         if (!V_ip6_forwarding || ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV)
  138                 goto freeit;
  139 
  140         /* Sanity checks */
  141         if (ip6->ip6_hlim != 255) {
  142                 nd6log((LOG_ERR,
  143                     "nd6_rs_input: invalid hlim (%d) from %s to %s on %s\n",
  144                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  145                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  146                 goto bad;
  147         }
  148 
  149         /*
  150          * Don't update the neighbor cache, if src = ::.
  151          * This indicates that the src has no IP address assigned yet.
  152          */
  153         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
  154                 goto freeit;
  155 
  156 #ifndef PULLDOWN_TEST
  157         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  158         nd_rs = (struct nd_router_solicit *)((caddr_t)ip6 + off);
  159 #else
  160         IP6_EXTHDR_GET(nd_rs, struct nd_router_solicit *, m, off, icmp6len);
  161         if (nd_rs == NULL) {
  162                 ICMP6STAT_INC(icp6s_tooshort);
  163                 return;
  164         }
  165 #endif
  166 
  167         icmp6len -= sizeof(*nd_rs);
  168         nd6_option_init(nd_rs + 1, icmp6len, &ndopts);
  169         if (nd6_options(&ndopts) < 0) {
  170                 nd6log((LOG_INFO,
  171                     "nd6_rs_input: invalid ND option, ignored\n"));
  172                 /* nd6_options have incremented stats */
  173                 goto freeit;
  174         }
  175 
  176         if (ndopts.nd_opts_src_lladdr) {
  177                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  178                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  179         }
  180 
  181         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  182                 nd6log((LOG_INFO,
  183                     "nd6_rs_input: lladdrlen mismatch for %s "
  184                     "(if %d, RS packet %d)\n",
  185                     ip6_sprintf(ip6bufs, &saddr6),
  186                     ifp->if_addrlen, lladdrlen - 2));
  187                 goto bad;
  188         }
  189 
  190         nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_ROUTER_SOLICIT, 0);
  191 
  192  freeit:
  193         m_freem(m);
  194         return;
  195 
  196  bad:
  197         ICMP6STAT_INC(icp6s_badrs);
  198         m_freem(m);
  199 }
  200 
  201 /*
  202  * Receive Router Advertisement Message.
  203  *
  204  * Based on RFC 2461
  205  * TODO: on-link bit on prefix information
  206  * TODO: ND_RA_FLAG_{OTHER,MANAGED} processing
  207  */
  208 void
  209 nd6_ra_input(struct mbuf *m, int off, int icmp6len)
  210 {
  211         struct ifnet *ifp = m->m_pkthdr.rcvif;
  212         struct nd_ifinfo *ndi = ND_IFINFO(ifp);
  213         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  214         struct nd_router_advert *nd_ra;
  215         struct in6_addr saddr6 = ip6->ip6_src;
  216         int mcast = 0;
  217         union nd_opts ndopts;
  218         struct nd_defrouter *dr;
  219         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  220 
  221         dr = NULL;
  222 
  223         /*
  224          * We only accept RAs only when the per-interface flag
  225          * ND6_IFF_ACCEPT_RTADV is on the receiving interface.
  226          */
  227         if (!(ndi->flags & ND6_IFF_ACCEPT_RTADV))
  228                 goto freeit;
  229 
  230         if (ip6->ip6_hlim != 255) {
  231                 nd6log((LOG_ERR,
  232                     "nd6_ra_input: invalid hlim (%d) from %s to %s on %s\n",
  233                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  234                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  235                 goto bad;
  236         }
  237 
  238         if (!IN6_IS_ADDR_LINKLOCAL(&saddr6)) {
  239                 nd6log((LOG_ERR,
  240                     "nd6_ra_input: src %s is not link-local\n",
  241                     ip6_sprintf(ip6bufs, &saddr6)));
  242                 goto bad;
  243         }
  244 
  245 #ifndef PULLDOWN_TEST
  246         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  247         nd_ra = (struct nd_router_advert *)((caddr_t)ip6 + off);
  248 #else
  249         IP6_EXTHDR_GET(nd_ra, struct nd_router_advert *, m, off, icmp6len);
  250         if (nd_ra == NULL) {
  251                 ICMP6STAT_INC(icp6s_tooshort);
  252                 return;
  253         }
  254 #endif
  255 
  256         icmp6len -= sizeof(*nd_ra);
  257         nd6_option_init(nd_ra + 1, icmp6len, &ndopts);
  258         if (nd6_options(&ndopts) < 0) {
  259                 nd6log((LOG_INFO,
  260                     "nd6_ra_input: invalid ND option, ignored\n"));
  261                 /* nd6_options have incremented stats */
  262                 goto freeit;
  263         }
  264 
  265     {
  266         struct nd_defrouter dr0;
  267         u_int32_t advreachable = nd_ra->nd_ra_reachable;
  268 
  269         /* remember if this is a multicasted advertisement */
  270         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
  271                 mcast = 1;
  272 
  273         bzero(&dr0, sizeof(dr0));
  274         dr0.rtaddr = saddr6;
  275         dr0.raflags = nd_ra->nd_ra_flags_reserved;
  276         /*
  277          * Effectively-disable routes from RA messages when
  278          * ND6_IFF_NO_RADR enabled on the receiving interface or
  279          * (ip6.forwarding == 1 && ip6.rfc6204w3 != 1).
  280          */
  281         if (ndi->flags & ND6_IFF_NO_RADR)
  282                 dr0.rtlifetime = 0;
  283         else if (V_ip6_forwarding && !V_ip6_rfc6204w3)
  284                 dr0.rtlifetime = 0;
  285         else
  286                 dr0.rtlifetime = ntohs(nd_ra->nd_ra_router_lifetime);
  287         dr0.expire = time_uptime + dr0.rtlifetime;
  288         dr0.ifp = ifp;
  289         /* unspecified or not? (RFC 2461 6.3.4) */
  290         if (advreachable) {
  291                 advreachable = ntohl(advreachable);
  292                 if (advreachable <= MAX_REACHABLE_TIME &&
  293                     ndi->basereachable != advreachable) {
  294                         ndi->basereachable = advreachable;
  295                         ndi->reachable = ND_COMPUTE_RTIME(ndi->basereachable);
  296                         ndi->recalctm = V_nd6_recalc_reachtm_interval; /* reset */
  297                 }
  298         }
  299         if (nd_ra->nd_ra_retransmit)
  300                 ndi->retrans = ntohl(nd_ra->nd_ra_retransmit);
  301         if (nd_ra->nd_ra_curhoplimit) {
  302                 if (ndi->chlim < nd_ra->nd_ra_curhoplimit)
  303                         ndi->chlim = nd_ra->nd_ra_curhoplimit;
  304                 else if (ndi->chlim != nd_ra->nd_ra_curhoplimit) {
  305                         log(LOG_ERR, "RA with a lower CurHopLimit sent from "
  306                             "%s on %s (current = %d, received = %d). "
  307                             "Ignored.\n", ip6_sprintf(ip6bufs, &ip6->ip6_src),
  308                             if_name(ifp), ndi->chlim, nd_ra->nd_ra_curhoplimit);
  309                 }
  310         }
  311         dr = defrtrlist_update(&dr0);
  312     }
  313 
  314         /*
  315          * prefix
  316          */
  317         if (ndopts.nd_opts_pi) {
  318                 struct nd_opt_hdr *pt;
  319                 struct nd_opt_prefix_info *pi = NULL;
  320                 struct nd_prefixctl pr;
  321 
  322                 for (pt = (struct nd_opt_hdr *)ndopts.nd_opts_pi;
  323                      pt <= (struct nd_opt_hdr *)ndopts.nd_opts_pi_end;
  324                      pt = (struct nd_opt_hdr *)((caddr_t)pt +
  325                                                 (pt->nd_opt_len << 3))) {
  326                         if (pt->nd_opt_type != ND_OPT_PREFIX_INFORMATION)
  327                                 continue;
  328                         pi = (struct nd_opt_prefix_info *)pt;
  329 
  330                         if (pi->nd_opt_pi_len != 4) {
  331                                 nd6log((LOG_INFO,
  332                                     "nd6_ra_input: invalid option "
  333                                     "len %d for prefix information option, "
  334                                     "ignored\n", pi->nd_opt_pi_len));
  335                                 continue;
  336                         }
  337 
  338                         if (128 < pi->nd_opt_pi_prefix_len) {
  339                                 nd6log((LOG_INFO,
  340                                     "nd6_ra_input: invalid prefix "
  341                                     "len %d for prefix information option, "
  342                                     "ignored\n", pi->nd_opt_pi_prefix_len));
  343                                 continue;
  344                         }
  345 
  346                         if (IN6_IS_ADDR_MULTICAST(&pi->nd_opt_pi_prefix)
  347                          || IN6_IS_ADDR_LINKLOCAL(&pi->nd_opt_pi_prefix)) {
  348                                 nd6log((LOG_INFO,
  349                                     "nd6_ra_input: invalid prefix "
  350                                     "%s, ignored\n",
  351                                     ip6_sprintf(ip6bufs,
  352                                         &pi->nd_opt_pi_prefix)));
  353                                 continue;
  354                         }
  355 
  356                         bzero(&pr, sizeof(pr));
  357                         pr.ndpr_prefix.sin6_family = AF_INET6;
  358                         pr.ndpr_prefix.sin6_len = sizeof(pr.ndpr_prefix);
  359                         pr.ndpr_prefix.sin6_addr = pi->nd_opt_pi_prefix;
  360                         pr.ndpr_ifp = (struct ifnet *)m->m_pkthdr.rcvif;
  361 
  362                         pr.ndpr_raf_onlink = (pi->nd_opt_pi_flags_reserved &
  363                             ND_OPT_PI_FLAG_ONLINK) ? 1 : 0;
  364                         pr.ndpr_raf_auto = (pi->nd_opt_pi_flags_reserved &
  365                             ND_OPT_PI_FLAG_AUTO) ? 1 : 0;
  366                         pr.ndpr_plen = pi->nd_opt_pi_prefix_len;
  367                         pr.ndpr_vltime = ntohl(pi->nd_opt_pi_valid_time);
  368                         pr.ndpr_pltime = ntohl(pi->nd_opt_pi_preferred_time);
  369                         (void)prelist_update(&pr, dr, m, mcast);
  370                 }
  371         }
  372         if (dr != NULL) {
  373                 defrouter_rele(dr);
  374                 dr = NULL;
  375         }
  376 
  377         /*
  378          * MTU
  379          */
  380         if (ndopts.nd_opts_mtu && ndopts.nd_opts_mtu->nd_opt_mtu_len == 1) {
  381                 u_long mtu;
  382                 u_long maxmtu;
  383 
  384                 mtu = (u_long)ntohl(ndopts.nd_opts_mtu->nd_opt_mtu_mtu);
  385 
  386                 /* lower bound */
  387                 if (mtu < IPV6_MMTU) {
  388                         nd6log((LOG_INFO, "nd6_ra_input: bogus mtu option "
  389                             "mtu=%lu sent from %s, ignoring\n",
  390                             mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src)));
  391                         goto skip;
  392                 }
  393 
  394                 /* upper bound */
  395                 maxmtu = (ndi->maxmtu && ndi->maxmtu < ifp->if_mtu)
  396                     ? ndi->maxmtu : ifp->if_mtu;
  397                 if (mtu <= maxmtu) {
  398                         int change = (ndi->linkmtu != mtu);
  399 
  400                         ndi->linkmtu = mtu;
  401                         if (change) /* in6_maxmtu may change */
  402                                 in6_setmaxmtu();
  403                 } else {
  404                         nd6log((LOG_INFO, "nd6_ra_input: bogus mtu "
  405                             "mtu=%lu sent from %s; "
  406                             "exceeds maxmtu %lu, ignoring\n",
  407                             mtu, ip6_sprintf(ip6bufs, &ip6->ip6_src), maxmtu));
  408                 }
  409         }
  410 
  411  skip:
  412 
  413         /*
  414          * Source link layer address
  415          */
  416     {
  417         char *lladdr = NULL;
  418         int lladdrlen = 0;
  419 
  420         if (ndopts.nd_opts_src_lladdr) {
  421                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  422                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  423         }
  424 
  425         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  426                 nd6log((LOG_INFO,
  427                     "nd6_ra_input: lladdrlen mismatch for %s "
  428                     "(if %d, RA packet %d)\n", ip6_sprintf(ip6bufs, &saddr6),
  429                     ifp->if_addrlen, lladdrlen - 2));
  430                 goto bad;
  431         }
  432 
  433         nd6_cache_lladdr(ifp, &saddr6, lladdr,
  434             lladdrlen, ND_ROUTER_ADVERT, 0);
  435 
  436         /*
  437          * Installing a link-layer address might change the state of the
  438          * router's neighbor cache, which might also affect our on-link
  439          * detection of adveritsed prefixes.
  440          */
  441         pfxlist_onlink_check();
  442     }
  443 
  444  freeit:
  445         m_freem(m);
  446         return;
  447 
  448  bad:
  449         ICMP6STAT_INC(icp6s_badra);
  450         m_freem(m);
  451 }
  452 
  453 /* tell the change to user processes watching the routing socket. */
  454 static void
  455 nd6_rtmsg(int cmd, struct rtentry *rt)
  456 {
  457         struct rt_addrinfo info;
  458         struct ifnet *ifp;
  459         struct ifaddr *ifa;
  460 
  461         bzero((caddr_t)&info, sizeof(info));
  462         info.rti_info[RTAX_DST] = rt_key(rt);
  463         info.rti_info[RTAX_GATEWAY] = rt->rt_gateway;
  464         info.rti_info[RTAX_NETMASK] = rt_mask(rt);
  465         ifp = rt->rt_ifp;
  466         if (ifp != NULL) {
  467                 IF_ADDR_RLOCK(ifp);
  468                 ifa = TAILQ_FIRST(&ifp->if_addrhead);
  469                 info.rti_info[RTAX_IFP] = ifa->ifa_addr;
  470                 ifa_ref(ifa);
  471                 IF_ADDR_RUNLOCK(ifp);
  472                 info.rti_info[RTAX_IFA] = rt->rt_ifa->ifa_addr;
  473         } else
  474                 ifa = NULL;
  475 
  476         rt_missmsg_fib(cmd, &info, rt->rt_flags, 0, rt->rt_fibnum);
  477         if (ifa != NULL)
  478                 ifa_free(ifa);
  479 }
  480 
  481 /*
  482  * default router list processing sub routines
  483  */
  484 
  485 static void
  486 defrouter_addreq(struct nd_defrouter *new)
  487 {
  488         struct sockaddr_in6 def, mask, gate;
  489         struct rtentry *newrt = NULL;
  490         int error;
  491 
  492         bzero(&def, sizeof(def));
  493         bzero(&mask, sizeof(mask));
  494         bzero(&gate, sizeof(gate));
  495 
  496         def.sin6_len = mask.sin6_len = gate.sin6_len =
  497             sizeof(struct sockaddr_in6);
  498         def.sin6_family = gate.sin6_family = AF_INET6;
  499         gate.sin6_addr = new->rtaddr;
  500 
  501         error = in6_rtrequest(RTM_ADD, (struct sockaddr *)&def,
  502             (struct sockaddr *)&gate, (struct sockaddr *)&mask,
  503             RTF_GATEWAY, &newrt, new->ifp->if_fib);
  504         if (newrt) {
  505                 nd6_rtmsg(RTM_ADD, newrt); /* tell user process */
  506                 RTFREE(newrt);
  507         }
  508         if (error == 0)
  509                 new->installed = 1;
  510 }
  511 
  512 struct nd_defrouter *
  513 defrouter_lookup_locked(struct in6_addr *addr, struct ifnet *ifp)
  514 {
  515         struct nd_defrouter *dr;
  516 
  517         ND6_LOCK_ASSERT();
  518         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry)
  519                 if (dr->ifp == ifp && IN6_ARE_ADDR_EQUAL(addr, &dr->rtaddr)) {
  520                         defrouter_ref(dr);
  521                         return (dr);
  522                 }
  523         return (NULL);
  524 }
  525 
  526 struct nd_defrouter *
  527 defrouter_lookup(struct in6_addr *addr, struct ifnet *ifp)
  528 {
  529         struct nd_defrouter *dr;
  530 
  531         ND6_RLOCK();
  532         dr = defrouter_lookup_locked(addr, ifp);
  533         ND6_RUNLOCK();
  534         return (dr);
  535 }
  536 
  537 void
  538 defrouter_ref(struct nd_defrouter *dr)
  539 {
  540 
  541         refcount_acquire(&dr->refcnt);
  542 }
  543 
  544 void
  545 defrouter_rele(struct nd_defrouter *dr)
  546 {
  547 
  548         if (refcount_release(&dr->refcnt))
  549                 free(dr, M_IP6NDP);
  550 }
  551 
  552 /*
  553  * Remove the default route for a given router.
  554  * This is just a subroutine function for defrouter_select_fib(), and
  555  * should not be called from anywhere else.
  556  */
  557 static void
  558 defrouter_delreq(struct nd_defrouter *dr)
  559 {
  560         struct sockaddr_in6 def, mask, gate;
  561         struct rtentry *oldrt = NULL;
  562 
  563         bzero(&def, sizeof(def));
  564         bzero(&mask, sizeof(mask));
  565         bzero(&gate, sizeof(gate));
  566 
  567         def.sin6_len = mask.sin6_len = gate.sin6_len =
  568             sizeof(struct sockaddr_in6);
  569         def.sin6_family = gate.sin6_family = AF_INET6;
  570         gate.sin6_addr = dr->rtaddr;
  571 
  572         in6_rtrequest(RTM_DELETE, (struct sockaddr *)&def,
  573             (struct sockaddr *)&gate,
  574             (struct sockaddr *)&mask, RTF_GATEWAY, &oldrt, dr->ifp->if_fib);
  575         if (oldrt) {
  576                 nd6_rtmsg(RTM_DELETE, oldrt);
  577                 RTFREE(oldrt);
  578         }
  579 
  580         dr->installed = 0;
  581 }
  582 
  583 /*
  584  * Remove all default routes from default router list.
  585  */
  586 void
  587 defrouter_reset(void)
  588 {
  589         struct nd_defrouter *dr, **dra;
  590         int count, i;
  591 
  592         count = i = 0;
  593 
  594         /*
  595          * We can't delete routes with the ND lock held, so make a copy of the
  596          * current default router list and use that when deleting routes.
  597          */
  598         ND6_RLOCK();
  599         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry)
  600                 count++;
  601         ND6_RUNLOCK();
  602 
  603         dra = malloc(count * sizeof(*dra), M_TEMP, M_WAITOK | M_ZERO);
  604 
  605         ND6_RLOCK();
  606         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
  607                 if (i == count)
  608                         break;
  609                 defrouter_ref(dr);
  610                 dra[i++] = dr;
  611         }
  612         ND6_RUNLOCK();
  613 
  614         for (i = 0; i < count && dra[i] != NULL; i++) {
  615                 defrouter_delreq(dra[i]);
  616                 defrouter_rele(dra[i]);
  617         }
  618         free(dra, M_TEMP);
  619 
  620         /*
  621          * XXX should we also nuke any default routers in the kernel, by
  622          * going through them by rtalloc1()?
  623          */
  624 }
  625 
  626 /*
  627  * Look up a matching default router list entry and remove it. Returns true if a
  628  * matching entry was found, false otherwise.
  629  */
  630 bool
  631 defrouter_remove(struct in6_addr *addr, struct ifnet *ifp)
  632 {
  633         struct nd_defrouter *dr;
  634 
  635         ND6_WLOCK();
  636         dr = defrouter_lookup_locked(addr, ifp);
  637         if (dr == NULL) {
  638                 ND6_WUNLOCK();
  639                 return (false);
  640         }
  641 
  642         defrouter_unlink(dr, NULL);
  643         ND6_WUNLOCK();
  644         defrouter_del(dr);
  645         defrouter_rele(dr);
  646         return (true);
  647 }
  648 
  649 /*
  650  * Remove a router from the global list and optionally stash it in a
  651  * caller-supplied queue.
  652  *
  653  * The ND lock must be held.
  654  */
  655 void
  656 defrouter_unlink(struct nd_defrouter *dr, struct nd_drhead *drq)
  657 {
  658 
  659         ND6_WLOCK_ASSERT();
  660         TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
  661         V_nd6_list_genid++;
  662         if (drq != NULL)
  663                 TAILQ_INSERT_TAIL(drq, dr, dr_entry);
  664 }
  665 
  666 void
  667 defrouter_del(struct nd_defrouter *dr)
  668 {
  669         struct nd_defrouter *deldr = NULL;
  670         struct nd_prefix *pr;
  671         struct nd_pfxrouter *pfxrtr;
  672 
  673         ND6_UNLOCK_ASSERT();
  674 
  675         /*
  676          * Flush all the routing table entries that use the router
  677          * as a next hop.
  678          */
  679         if (ND_IFINFO(dr->ifp)->flags & ND6_IFF_ACCEPT_RTADV)
  680                 rt6_flush(&dr->rtaddr, dr->ifp);
  681 
  682         if (dr->installed) {
  683                 deldr = dr;
  684                 defrouter_delreq(dr);
  685         }
  686 
  687         /*
  688          * Also delete all the pointers to the router in each prefix lists.
  689          */
  690         ND6_WLOCK();
  691         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
  692                 if ((pfxrtr = pfxrtr_lookup(pr, dr)) != NULL)
  693                         pfxrtr_del(pfxrtr);
  694         }
  695         ND6_WUNLOCK();
  696 
  697         pfxlist_onlink_check();
  698 
  699         /*
  700          * If the router is the primary one, choose a new one.
  701          * Note that defrouter_select_fib() will remove the current
  702          * gateway from the routing table.
  703          */
  704         if (deldr)
  705                 defrouter_select_fib(deldr->ifp->if_fib);
  706 
  707         /*
  708          * Release the list reference.
  709          */
  710         defrouter_rele(dr);
  711 }
  712 
  713 /*
  714  * Default Router Selection according to Section 6.3.6 of RFC 2461 and
  715  * draft-ietf-ipngwg-router-selection:
  716  * 1) Routers that are reachable or probably reachable should be preferred.
  717  *    If we have more than one (probably) reachable router, prefer ones
  718  *    with the highest router preference.
  719  * 2) When no routers on the list are known to be reachable or
  720  *    probably reachable, routers SHOULD be selected in a round-robin
  721  *    fashion, regardless of router preference values.
  722  * 3) If the Default Router List is empty, assume that all
  723  *    destinations are on-link.
  724  *
  725  * We assume nd_defrouter is sorted by router preference value.
  726  * Since the code below covers both with and without router preference cases,
  727  * we do not need to classify the cases by ifdef.
  728  *
  729  * At this moment, we do not try to install more than one default router,
  730  * even when the multipath routing is available, because we're not sure about
  731  * the benefits for stub hosts comparing to the risk of making the code
  732  * complicated and the possibility of introducing bugs.
  733  *
  734  * We maintain a single list of routers for multiple FIBs, only considering one
  735  * at a time based on the receiving interface's FIB. If @fibnum is RT_ALL_FIBS,
  736  * we do the whole thing multiple times.
  737  */
  738 void
  739 defrouter_select_fib(int fibnum)
  740 {
  741         struct nd_defrouter *dr, *selected_dr, *installed_dr;
  742         struct llentry *ln = NULL;
  743 
  744         if (fibnum == RT_ALL_FIBS) {
  745                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
  746                         defrouter_select_fib(fibnum);
  747                 }
  748         }
  749 
  750         ND6_RLOCK();
  751         /*
  752          * Let's handle easy case (3) first:
  753          * If default router list is empty, there's nothing to be done.
  754          */
  755         if (TAILQ_EMPTY(&V_nd_defrouter)) {
  756                 ND6_RUNLOCK();
  757                 return;
  758         }
  759 
  760         /*
  761          * Search for a (probably) reachable router from the list.
  762          * We just pick up the first reachable one (if any), assuming that
  763          * the ordering rule of the list described in defrtrlist_update().
  764          */
  765         selected_dr = installed_dr = NULL;
  766         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
  767                 IF_AFDATA_RLOCK(dr->ifp);
  768                 if (selected_dr == NULL && dr->ifp->if_fib == fibnum &&
  769                     (ln = nd6_lookup(&dr->rtaddr, 0, dr->ifp)) &&
  770                     ND6_IS_LLINFO_PROBREACH(ln)) {
  771                         selected_dr = dr;
  772                         defrouter_ref(selected_dr);
  773                 }
  774                 IF_AFDATA_RUNLOCK(dr->ifp);
  775                 if (ln != NULL) {
  776                         LLE_RUNLOCK(ln);
  777                         ln = NULL;
  778                 }
  779 
  780                 if (dr->installed && dr->ifp->if_fib == fibnum) {
  781                         if (installed_dr == NULL) {
  782                                 installed_dr = dr;
  783                                 defrouter_ref(installed_dr);
  784                         } else {
  785                                 /*
  786                                  * this should not happen.
  787                                  * warn for diagnosis.
  788                                  */
  789                                 log(LOG_ERR, "defrouter_select_fib: more than "
  790                                              "one router is installed\n");
  791                         }
  792                 }
  793         }
  794         /*
  795          * If none of the default routers was found to be reachable,
  796          * round-robin the list regardless of preference.
  797          * Otherwise, if we have an installed router, check if the selected
  798          * (reachable) router should really be preferred to the installed one.
  799          * We only prefer the new router when the old one is not reachable
  800          * or when the new one has a really higher preference value.
  801          */
  802         if (selected_dr == NULL) {
  803                 if (installed_dr == NULL ||
  804                     TAILQ_NEXT(installed_dr, dr_entry) == NULL)
  805                         dr = TAILQ_FIRST(&V_nd_defrouter);
  806                 else
  807                         dr = TAILQ_NEXT(installed_dr, dr_entry);
  808 
  809                 /* Ensure we select a router for this FIB. */
  810                 TAILQ_FOREACH_FROM(dr, &V_nd_defrouter, dr_entry) {
  811                         if (dr->ifp->if_fib == fibnum) {
  812                                 selected_dr = dr;
  813                                 defrouter_ref(selected_dr);
  814                                 break;
  815                         }
  816                 }
  817         } else if (installed_dr != NULL) {
  818                 IF_AFDATA_RLOCK(installed_dr->ifp);
  819                 if ((ln = nd6_lookup(&installed_dr->rtaddr, 0,
  820                                      installed_dr->ifp)) &&
  821                     ND6_IS_LLINFO_PROBREACH(ln) &&
  822                     installed_dr->ifp->if_fib == fibnum &&
  823                     rtpref(selected_dr) <= rtpref(installed_dr)) {
  824                         defrouter_rele(selected_dr);
  825                         selected_dr = installed_dr;
  826                 }
  827                 IF_AFDATA_RUNLOCK(installed_dr->ifp);
  828                 if (ln != NULL)
  829                         LLE_RUNLOCK(ln);
  830         }
  831         ND6_RUNLOCK();
  832 
  833         /*
  834          * If we selected a router for this FIB and it's different
  835          * than the installed one, remove the installed router and
  836          * install the selected one in its place.
  837          */
  838         if (installed_dr != selected_dr) {
  839                 if (installed_dr != NULL) {
  840                         defrouter_delreq(installed_dr);
  841                         defrouter_rele(installed_dr);
  842                 }
  843                 if (selected_dr != NULL)
  844                         defrouter_addreq(selected_dr);
  845         }
  846         if (selected_dr != NULL)
  847                 defrouter_rele(selected_dr);
  848 }
  849 
  850 /*
  851  * Maintain old KPI for default router selection.
  852  * If unspecified, we can re-select routers for all FIBs.
  853  */
  854 void
  855 defrouter_select(void)
  856 {
  857         defrouter_select_fib(RT_ALL_FIBS);
  858 }
  859 
  860 /*
  861  * for default router selection
  862  * regards router-preference field as a 2-bit signed integer
  863  */
  864 static int
  865 rtpref(struct nd_defrouter *dr)
  866 {
  867         switch (dr->raflags & ND_RA_FLAG_RTPREF_MASK) {
  868         case ND_RA_FLAG_RTPREF_HIGH:
  869                 return (RTPREF_HIGH);
  870         case ND_RA_FLAG_RTPREF_MEDIUM:
  871         case ND_RA_FLAG_RTPREF_RSV:
  872                 return (RTPREF_MEDIUM);
  873         case ND_RA_FLAG_RTPREF_LOW:
  874                 return (RTPREF_LOW);
  875         default:
  876                 /*
  877                  * This case should never happen.  If it did, it would mean a
  878                  * serious bug of kernel internal.  We thus always bark here.
  879                  * Or, can we even panic?
  880                  */
  881                 log(LOG_ERR, "rtpref: impossible RA flag %x\n", dr->raflags);
  882                 return (RTPREF_INVALID);
  883         }
  884         /* NOTREACHED */
  885 }
  886 
  887 static struct nd_defrouter *
  888 defrtrlist_update(struct nd_defrouter *new)
  889 {
  890         struct nd_defrouter *dr, *n;
  891         uint64_t genid;
  892         int oldpref;
  893         bool writelocked;
  894 
  895         if (new->rtlifetime == 0) {
  896                 defrouter_remove(&new->rtaddr, new->ifp);
  897                 return (NULL);
  898         }
  899 
  900         ND6_RLOCK();
  901         writelocked = false;
  902 restart:
  903         dr = defrouter_lookup_locked(&new->rtaddr, new->ifp);
  904         if (dr != NULL) {
  905                 oldpref = rtpref(dr);
  906 
  907                 /* override */
  908                 dr->raflags = new->raflags; /* XXX flag check */
  909                 dr->rtlifetime = new->rtlifetime;
  910                 dr->expire = new->expire;
  911 
  912                 /*
  913                  * If the preference does not change, there's no need
  914                  * to sort the entries. Also make sure the selected
  915                  * router is still installed in the kernel.
  916                  */
  917                 if (dr->installed && rtpref(new) == oldpref) {
  918                         if (writelocked)
  919                                 ND6_WUNLOCK();
  920                         else
  921                                 ND6_RUNLOCK();
  922                         return (dr);
  923                 }
  924         }
  925 
  926         /*
  927          * The router needs to be reinserted into the default router
  928          * list, so upgrade to a write lock. If that fails and the list
  929          * has potentially changed while the lock was dropped, we'll
  930          * redo the lookup with the write lock held.
  931          */
  932         if (!writelocked) {
  933                 writelocked = true;
  934                 if (!ND6_TRY_UPGRADE()) {
  935                         genid = V_nd6_list_genid;
  936                         ND6_RUNLOCK();
  937                         ND6_WLOCK();
  938                         if (genid != V_nd6_list_genid)
  939                                 goto restart;
  940                 }
  941         }
  942 
  943         if (dr != NULL) {
  944                 /*
  945                  * The preferred router may have changed, so relocate this
  946                  * router.
  947                  */
  948                 TAILQ_REMOVE(&V_nd_defrouter, dr, dr_entry);
  949                 n = dr;
  950         } else {
  951                 n = malloc(sizeof(*n), M_IP6NDP, M_NOWAIT | M_ZERO);
  952                 if (n == NULL) {
  953                         ND6_WUNLOCK();
  954                         return (NULL);
  955                 }
  956                 memcpy(n, new, sizeof(*n));
  957                 /* Initialize with an extra reference for the caller. */
  958                 refcount_init(&n->refcnt, 2);
  959         }
  960 
  961         /*
  962          * Insert the new router in the Default Router List;
  963          * The Default Router List should be in the descending order
  964          * of router-preferece.  Routers with the same preference are
  965          * sorted in the arriving time order.
  966          */
  967 
  968         /* insert at the end of the group */
  969         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
  970                 if (rtpref(n) > rtpref(dr))
  971                         break;
  972         }
  973         if (dr != NULL)
  974                 TAILQ_INSERT_BEFORE(dr, n, dr_entry);
  975         else
  976                 TAILQ_INSERT_TAIL(&V_nd_defrouter, n, dr_entry);
  977         V_nd6_list_genid++;
  978         ND6_WUNLOCK();
  979 
  980         defrouter_select_fib(new->ifp->if_fib);
  981 
  982         return (n);
  983 }
  984 
  985 static struct nd_pfxrouter *
  986 pfxrtr_lookup(struct nd_prefix *pr, struct nd_defrouter *dr)
  987 {
  988         struct nd_pfxrouter *search;
  989 
  990         ND6_LOCK_ASSERT();
  991 
  992         LIST_FOREACH(search, &pr->ndpr_advrtrs, pfr_entry) {
  993                 if (search->router == dr)
  994                         break;
  995         }
  996         return (search);
  997 }
  998 
  999 static void
 1000 pfxrtr_add(struct nd_prefix *pr, struct nd_defrouter *dr)
 1001 {
 1002         struct nd_pfxrouter *new;
 1003         bool update;
 1004 
 1005         ND6_UNLOCK_ASSERT();
 1006 
 1007         ND6_RLOCK();
 1008         if (pfxrtr_lookup(pr, dr) != NULL) {
 1009                 ND6_RUNLOCK();
 1010                 return;
 1011         }
 1012         ND6_RUNLOCK();
 1013 
 1014         new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
 1015         if (new == NULL)
 1016                 return;
 1017         defrouter_ref(dr);
 1018         new->router = dr;
 1019 
 1020         ND6_WLOCK();
 1021         if (pfxrtr_lookup(pr, dr) == NULL) {
 1022                 LIST_INSERT_HEAD(&pr->ndpr_advrtrs, new, pfr_entry);
 1023                 update = true;
 1024         } else {
 1025                 /* We lost a race to add the reference. */
 1026                 defrouter_rele(dr);
 1027                 free(new, M_IP6NDP);
 1028                 update = false;
 1029         }
 1030         ND6_WUNLOCK();
 1031 
 1032         if (update)
 1033                 pfxlist_onlink_check();
 1034 }
 1035 
 1036 static void
 1037 pfxrtr_del(struct nd_pfxrouter *pfr)
 1038 {
 1039 
 1040         ND6_WLOCK_ASSERT();
 1041 
 1042         LIST_REMOVE(pfr, pfr_entry);
 1043         defrouter_rele(pfr->router);
 1044         free(pfr, M_IP6NDP);
 1045 }
 1046 
 1047 static struct nd_prefix *
 1048 nd6_prefix_lookup_locked(struct nd_prefixctl *key)
 1049 {
 1050         struct nd_prefix *search;
 1051 
 1052         ND6_LOCK_ASSERT();
 1053 
 1054         LIST_FOREACH(search, &V_nd_prefix, ndpr_entry) {
 1055                 if (key->ndpr_ifp == search->ndpr_ifp &&
 1056                     key->ndpr_plen == search->ndpr_plen &&
 1057                     in6_are_prefix_equal(&key->ndpr_prefix.sin6_addr,
 1058                     &search->ndpr_prefix.sin6_addr, key->ndpr_plen)) {
 1059                         nd6_prefix_ref(search);
 1060                         break;
 1061                 }
 1062         }
 1063         return (search);
 1064 }
 1065 
 1066 struct nd_prefix *
 1067 nd6_prefix_lookup(struct nd_prefixctl *key)
 1068 {
 1069         struct nd_prefix *search;
 1070 
 1071         ND6_RLOCK();
 1072         search = nd6_prefix_lookup_locked(key);
 1073         ND6_RUNLOCK();
 1074         return (search);
 1075 }
 1076 
 1077 void
 1078 nd6_prefix_ref(struct nd_prefix *pr)
 1079 {
 1080 
 1081         refcount_acquire(&pr->ndpr_refcnt);
 1082 }
 1083 
 1084 void
 1085 nd6_prefix_rele(struct nd_prefix *pr)
 1086 {
 1087 
 1088         if (refcount_release(&pr->ndpr_refcnt)) {
 1089                 KASSERT(LIST_EMPTY(&pr->ndpr_advrtrs),
 1090                     ("prefix %p has advertising routers", pr));
 1091                 free(pr, M_IP6NDP);
 1092         }
 1093 }
 1094 
 1095 int
 1096 nd6_prelist_add(struct nd_prefixctl *pr, struct nd_defrouter *dr,
 1097     struct nd_prefix **newp)
 1098 {
 1099         struct nd_prefix *new;
 1100         char ip6buf[INET6_ADDRSTRLEN];
 1101         int error;
 1102 
 1103         new = malloc(sizeof(*new), M_IP6NDP, M_NOWAIT | M_ZERO);
 1104         if (new == NULL)
 1105                 return (ENOMEM);
 1106         refcount_init(&new->ndpr_refcnt, newp != NULL ? 2 : 1);
 1107         new->ndpr_ifp = pr->ndpr_ifp;
 1108         new->ndpr_prefix = pr->ndpr_prefix;
 1109         new->ndpr_plen = pr->ndpr_plen;
 1110         new->ndpr_vltime = pr->ndpr_vltime;
 1111         new->ndpr_pltime = pr->ndpr_pltime;
 1112         new->ndpr_flags = pr->ndpr_flags;
 1113         if ((error = in6_init_prefix_ltimes(new)) != 0) {
 1114                 free(new, M_IP6NDP);
 1115                 return (error);
 1116         }
 1117         new->ndpr_lastupdate = time_uptime;
 1118 
 1119         /* initialization */
 1120         LIST_INIT(&new->ndpr_advrtrs);
 1121         in6_prefixlen2mask(&new->ndpr_mask, new->ndpr_plen);
 1122         /* make prefix in the canonical form */
 1123         IN6_MASK_ADDR(&new->ndpr_prefix.sin6_addr, &new->ndpr_mask);
 1124 
 1125         ND6_WLOCK();
 1126         LIST_INSERT_HEAD(&V_nd_prefix, new, ndpr_entry);
 1127         V_nd6_list_genid++;
 1128         ND6_WUNLOCK();
 1129 
 1130         /* ND_OPT_PI_FLAG_ONLINK processing */
 1131         if (new->ndpr_raf_onlink) {
 1132                 ND6_ONLINK_LOCK();
 1133                 if ((error = nd6_prefix_onlink(new)) != 0) {
 1134                         nd6log((LOG_ERR, "nd6_prelist_add: failed to make "
 1135                             "the prefix %s/%d on-link on %s (errno=%d)\n",
 1136                             ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1137                             pr->ndpr_plen, if_name(pr->ndpr_ifp), error));
 1138                         /* proceed anyway. XXX: is it correct? */
 1139                 }
 1140                 ND6_ONLINK_UNLOCK();
 1141         }
 1142 
 1143         if (dr != NULL)
 1144                 pfxrtr_add(new, dr);
 1145         if (newp != NULL)
 1146                 *newp = new;
 1147         return (0);
 1148 }
 1149 
 1150 /*
 1151  * Remove a prefix from the prefix list and optionally stash it in a
 1152  * caller-provided list.
 1153  *
 1154  * The ND6 lock must be held.
 1155  */
 1156 void
 1157 nd6_prefix_unlink(struct nd_prefix *pr, struct nd_prhead *list)
 1158 {
 1159 
 1160         ND6_WLOCK_ASSERT();
 1161 
 1162         LIST_REMOVE(pr, ndpr_entry);
 1163         V_nd6_list_genid++;
 1164         if (list != NULL)
 1165                 LIST_INSERT_HEAD(list, pr, ndpr_entry);
 1166 }
 1167 
 1168 /*
 1169  * Free an unlinked prefix, first marking it off-link if necessary.
 1170  */
 1171 void
 1172 nd6_prefix_del(struct nd_prefix *pr)
 1173 {
 1174         struct nd_pfxrouter *pfr, *next;
 1175         int e;
 1176         char ip6buf[INET6_ADDRSTRLEN];
 1177 
 1178         KASSERT(pr->ndpr_addrcnt == 0,
 1179             ("prefix %p has referencing addresses", pr));
 1180         ND6_UNLOCK_ASSERT();
 1181 
 1182         /*
 1183          * Though these flags are now meaningless, we'd rather keep the value
 1184          * of pr->ndpr_raf_onlink and pr->ndpr_raf_auto not to confuse users
 1185          * when executing "ndp -p".
 1186          */
 1187         if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 1188                 ND6_ONLINK_LOCK();
 1189                 if ((e = nd6_prefix_offlink(pr)) != 0) {
 1190                         nd6log((LOG_ERR,
 1191                             "nd6_prefix_del: failed to make %s/%d offlink "
 1192                             "on %s, errno=%d\n",
 1193                             ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1194                             pr->ndpr_plen, if_name(pr->ndpr_ifp), e));
 1195                         /* what should we do? */
 1196                 }
 1197                 ND6_ONLINK_UNLOCK();
 1198         }
 1199 
 1200         /* Release references to routers that have advertised this prefix. */
 1201         ND6_WLOCK();
 1202         LIST_FOREACH_SAFE(pfr, &pr->ndpr_advrtrs, pfr_entry, next)
 1203                 pfxrtr_del(pfr);
 1204         ND6_WUNLOCK();
 1205 
 1206         nd6_prefix_rele(pr);
 1207 
 1208         pfxlist_onlink_check();
 1209 }
 1210 
 1211 static int
 1212 prelist_update(struct nd_prefixctl *new, struct nd_defrouter *dr,
 1213     struct mbuf *m, int mcast)
 1214 {
 1215         struct in6_ifaddr *ia6 = NULL, *ia6_match = NULL;
 1216         struct ifaddr *ifa;
 1217         struct ifnet *ifp = new->ndpr_ifp;
 1218         struct nd_prefix *pr;
 1219         int error = 0;
 1220         int auth;
 1221         struct in6_addrlifetime lt6_tmp;
 1222         char ip6buf[INET6_ADDRSTRLEN];
 1223 
 1224         auth = 0;
 1225         if (m) {
 1226                 /*
 1227                  * Authenticity for NA consists authentication for
 1228                  * both IP header and IP datagrams, doesn't it ?
 1229                  */
 1230 #if defined(M_AUTHIPHDR) && defined(M_AUTHIPDGM)
 1231                 auth = ((m->m_flags & M_AUTHIPHDR) &&
 1232                     (m->m_flags & M_AUTHIPDGM));
 1233 #endif
 1234         }
 1235 
 1236         if ((pr = nd6_prefix_lookup(new)) != NULL) {
 1237                 /*
 1238                  * nd6_prefix_lookup() ensures that pr and new have the same
 1239                  * prefix on a same interface.
 1240                  */
 1241 
 1242                 /*
 1243                  * Update prefix information.  Note that the on-link (L) bit
 1244                  * and the autonomous (A) bit should NOT be changed from 1
 1245                  * to 0.
 1246                  */
 1247                 if (new->ndpr_raf_onlink == 1)
 1248                         pr->ndpr_raf_onlink = 1;
 1249                 if (new->ndpr_raf_auto == 1)
 1250                         pr->ndpr_raf_auto = 1;
 1251                 if (new->ndpr_raf_onlink) {
 1252                         pr->ndpr_vltime = new->ndpr_vltime;
 1253                         pr->ndpr_pltime = new->ndpr_pltime;
 1254                         (void)in6_init_prefix_ltimes(pr); /* XXX error case? */
 1255                         pr->ndpr_lastupdate = time_uptime;
 1256                 }
 1257 
 1258                 if (new->ndpr_raf_onlink &&
 1259                     (pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
 1260                         ND6_ONLINK_LOCK();
 1261                         if ((error = nd6_prefix_onlink(pr)) != 0) {
 1262                                 nd6log((LOG_ERR,
 1263                                     "prelist_update: failed to make "
 1264                                     "the prefix %s/%d on-link on %s "
 1265                                     "(errno=%d)\n",
 1266                                     ip6_sprintf(ip6buf,
 1267                                         &pr->ndpr_prefix.sin6_addr),
 1268                                     pr->ndpr_plen, if_name(pr->ndpr_ifp),
 1269                                     error));
 1270                                 /* proceed anyway. XXX: is it correct? */
 1271                         }
 1272                         ND6_ONLINK_UNLOCK();
 1273                 }
 1274 
 1275                 if (dr != NULL)
 1276                         pfxrtr_add(pr, dr);
 1277         } else {
 1278                 if (new->ndpr_vltime == 0)
 1279                         goto end;
 1280                 if (new->ndpr_raf_onlink == 0 && new->ndpr_raf_auto == 0)
 1281                         goto end;
 1282 
 1283                 error = nd6_prelist_add(new, dr, &pr);
 1284                 if (error != 0) {
 1285                         nd6log((LOG_NOTICE, "prelist_update: "
 1286                             "nd6_prelist_add failed for %s/%d on %s errno=%d\n",
 1287                             ip6_sprintf(ip6buf, &new->ndpr_prefix.sin6_addr),
 1288                             new->ndpr_plen, if_name(new->ndpr_ifp), error));
 1289                         goto end; /* we should just give up in this case. */
 1290                 }
 1291 
 1292                 /*
 1293                  * XXX: from the ND point of view, we can ignore a prefix
 1294                  * with the on-link bit being zero.  However, we need a
 1295                  * prefix structure for references from autoconfigured
 1296                  * addresses.  Thus, we explicitly make sure that the prefix
 1297                  * itself expires now.
 1298                  */
 1299                 if (pr->ndpr_raf_onlink == 0) {
 1300                         pr->ndpr_vltime = 0;
 1301                         pr->ndpr_pltime = 0;
 1302                         in6_init_prefix_ltimes(pr);
 1303                 }
 1304         }
 1305 
 1306         /*
 1307          * Address autoconfiguration based on Section 5.5.3 of RFC 2462.
 1308          * Note that pr must be non NULL at this point.
 1309          */
 1310 
 1311         /* 5.5.3 (a). Ignore the prefix without the A bit set. */
 1312         if (!new->ndpr_raf_auto)
 1313                 goto end;
 1314 
 1315         /*
 1316          * 5.5.3 (b). the link-local prefix should have been ignored in
 1317          * nd6_ra_input.
 1318          */
 1319 
 1320         /* 5.5.3 (c). Consistency check on lifetimes: pltime <= vltime. */
 1321         if (new->ndpr_pltime > new->ndpr_vltime) {
 1322                 error = EINVAL; /* XXX: won't be used */
 1323                 goto end;
 1324         }
 1325 
 1326         /*
 1327          * 5.5.3 (d).  If the prefix advertised is not equal to the prefix of
 1328          * an address configured by stateless autoconfiguration already in the
 1329          * list of addresses associated with the interface, and the Valid
 1330          * Lifetime is not 0, form an address.  We first check if we have
 1331          * a matching prefix.
 1332          * Note: we apply a clarification in rfc2462bis-02 here.  We only
 1333          * consider autoconfigured addresses while RFC2462 simply said
 1334          * "address".
 1335          */
 1336         IF_ADDR_RLOCK(ifp);
 1337         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1338                 struct in6_ifaddr *ifa6;
 1339                 u_int32_t remaininglifetime;
 1340 
 1341                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1342                         continue;
 1343 
 1344                 ifa6 = (struct in6_ifaddr *)ifa;
 1345 
 1346                 /*
 1347                  * We only consider autoconfigured addresses as per rfc2462bis.
 1348                  */
 1349                 if (!(ifa6->ia6_flags & IN6_IFF_AUTOCONF))
 1350                         continue;
 1351 
 1352                 /*
 1353                  * Spec is not clear here, but I believe we should concentrate
 1354                  * on unicast (i.e. not anycast) addresses.
 1355                  * XXX: other ia6_flags? detached or duplicated?
 1356                  */
 1357                 if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0)
 1358                         continue;
 1359 
 1360                 /*
 1361                  * Ignore the address if it is not associated with a prefix
 1362                  * or is associated with a prefix that is different from this
 1363                  * one.  (pr is never NULL here)
 1364                  */
 1365                 if (ifa6->ia6_ndpr != pr)
 1366                         continue;
 1367 
 1368                 if (ia6_match == NULL) /* remember the first one */
 1369                         ia6_match = ifa6;
 1370 
 1371                 /*
 1372                  * An already autoconfigured address matched.  Now that we
 1373                  * are sure there is at least one matched address, we can
 1374                  * proceed to 5.5.3. (e): update the lifetimes according to the
 1375                  * "two hours" rule and the privacy extension.
 1376                  * We apply some clarifications in rfc2462bis:
 1377                  * - use remaininglifetime instead of storedlifetime as a
 1378                  *   variable name
 1379                  * - remove the dead code in the "two-hour" rule
 1380                  */
 1381 #define TWOHOUR         (120*60)
 1382                 lt6_tmp = ifa6->ia6_lifetime;
 1383 
 1384                 if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME)
 1385                         remaininglifetime = ND6_INFINITE_LIFETIME;
 1386                 else if (time_uptime - ifa6->ia6_updatetime >
 1387                          lt6_tmp.ia6t_vltime) {
 1388                         /*
 1389                          * The case of "invalid" address.  We should usually
 1390                          * not see this case.
 1391                          */
 1392                         remaininglifetime = 0;
 1393                 } else
 1394                         remaininglifetime = lt6_tmp.ia6t_vltime -
 1395                             (time_uptime - ifa6->ia6_updatetime);
 1396 
 1397                 /* when not updating, keep the current stored lifetime. */
 1398                 lt6_tmp.ia6t_vltime = remaininglifetime;
 1399 
 1400                 if (TWOHOUR < new->ndpr_vltime ||
 1401                     remaininglifetime < new->ndpr_vltime) {
 1402                         lt6_tmp.ia6t_vltime = new->ndpr_vltime;
 1403                 } else if (remaininglifetime <= TWOHOUR) {
 1404                         if (auth) {
 1405                                 lt6_tmp.ia6t_vltime = new->ndpr_vltime;
 1406                         }
 1407                 } else {
 1408                         /*
 1409                          * new->ndpr_vltime <= TWOHOUR &&
 1410                          * TWOHOUR < remaininglifetime
 1411                          */
 1412                         lt6_tmp.ia6t_vltime = TWOHOUR;
 1413                 }
 1414 
 1415                 /* The 2 hour rule is not imposed for preferred lifetime. */
 1416                 lt6_tmp.ia6t_pltime = new->ndpr_pltime;
 1417 
 1418                 in6_init_address_ltimes(pr, &lt6_tmp);
 1419 
 1420                 /*
 1421                  * We need to treat lifetimes for temporary addresses
 1422                  * differently, according to
 1423                  * draft-ietf-ipv6-privacy-addrs-v2-01.txt 3.3 (1);
 1424                  * we only update the lifetimes when they are in the maximum
 1425                  * intervals.
 1426                  */
 1427                 if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
 1428                         u_int32_t maxvltime, maxpltime;
 1429 
 1430                         if (V_ip6_temp_valid_lifetime >
 1431                             (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
 1432                             V_ip6_desync_factor)) {
 1433                                 maxvltime = V_ip6_temp_valid_lifetime -
 1434                                     (time_uptime - ifa6->ia6_createtime) -
 1435                                     V_ip6_desync_factor;
 1436                         } else
 1437                                 maxvltime = 0;
 1438                         if (V_ip6_temp_preferred_lifetime >
 1439                             (u_int32_t)((time_uptime - ifa6->ia6_createtime) +
 1440                             V_ip6_desync_factor)) {
 1441                                 maxpltime = V_ip6_temp_preferred_lifetime -
 1442                                     (time_uptime - ifa6->ia6_createtime) -
 1443                                     V_ip6_desync_factor;
 1444                         } else
 1445                                 maxpltime = 0;
 1446 
 1447                         if (lt6_tmp.ia6t_vltime == ND6_INFINITE_LIFETIME ||
 1448                             lt6_tmp.ia6t_vltime > maxvltime) {
 1449                                 lt6_tmp.ia6t_vltime = maxvltime;
 1450                         }
 1451                         if (lt6_tmp.ia6t_pltime == ND6_INFINITE_LIFETIME ||
 1452                             lt6_tmp.ia6t_pltime > maxpltime) {
 1453                                 lt6_tmp.ia6t_pltime = maxpltime;
 1454                         }
 1455                 }
 1456                 ifa6->ia6_lifetime = lt6_tmp;
 1457                 ifa6->ia6_updatetime = time_uptime;
 1458         }
 1459         IF_ADDR_RUNLOCK(ifp);
 1460         if (ia6_match == NULL && new->ndpr_vltime) {
 1461                 int ifidlen;
 1462 
 1463                 /*
 1464                  * 5.5.3 (d) (continued)
 1465                  * No address matched and the valid lifetime is non-zero.
 1466                  * Create a new address.
 1467                  */
 1468 
 1469                 /*
 1470                  * Prefix Length check:
 1471                  * If the sum of the prefix length and interface identifier
 1472                  * length does not equal 128 bits, the Prefix Information
 1473                  * option MUST be ignored.  The length of the interface
 1474                  * identifier is defined in a separate link-type specific
 1475                  * document.
 1476                  */
 1477                 ifidlen = in6_if2idlen(ifp);
 1478                 if (ifidlen < 0) {
 1479                         /* this should not happen, so we always log it. */
 1480                         log(LOG_ERR, "prelist_update: IFID undefined (%s)\n",
 1481                             if_name(ifp));
 1482                         goto end;
 1483                 }
 1484                 if (ifidlen + pr->ndpr_plen != 128) {
 1485                         nd6log((LOG_INFO,
 1486                             "prelist_update: invalid prefixlen "
 1487                             "%d for %s, ignored\n",
 1488                             pr->ndpr_plen, if_name(ifp)));
 1489                         goto end;
 1490                 }
 1491 
 1492                 if ((ia6 = in6_ifadd(new, mcast)) != NULL) {
 1493                         /*
 1494                          * note that we should use pr (not new) for reference.
 1495                          */
 1496                         pr->ndpr_addrcnt++;
 1497                         ia6->ia6_ndpr = pr;
 1498 
 1499                         /*
 1500                          * RFC 3041 3.3 (2).
 1501                          * When a new public address is created as described
 1502                          * in RFC2462, also create a new temporary address.
 1503                          *
 1504                          * RFC 3041 3.5.
 1505                          * When an interface connects to a new link, a new
 1506                          * randomized interface identifier should be generated
 1507                          * immediately together with a new set of temporary
 1508                          * addresses.  Thus, we specifiy 1 as the 2nd arg of
 1509                          * in6_tmpifadd().
 1510                          */
 1511                         if (V_ip6_use_tempaddr) {
 1512                                 int e;
 1513                                 if ((e = in6_tmpifadd(ia6, 1, 1)) != 0) {
 1514                                         nd6log((LOG_NOTICE, "prelist_update: "
 1515                                             "failed to create a temporary "
 1516                                             "address, errno=%d\n",
 1517                                             e));
 1518                                 }
 1519                         }
 1520                         ifa_free(&ia6->ia_ifa);
 1521 
 1522                         /*
 1523                          * A newly added address might affect the status
 1524                          * of other addresses, so we check and update it.
 1525                          * XXX: what if address duplication happens?
 1526                          */
 1527                         pfxlist_onlink_check();
 1528                 } else {
 1529                         /* just set an error. do not bark here. */
 1530                         error = EADDRNOTAVAIL; /* XXX: might be unused. */
 1531                 }
 1532         }
 1533 
 1534 end:
 1535         if (pr != NULL)
 1536                 nd6_prefix_rele(pr);
 1537         return (error);
 1538 }
 1539 
 1540 /*
 1541  * A supplement function used in the on-link detection below;
 1542  * detect if a given prefix has a (probably) reachable advertising router.
 1543  * XXX: lengthy function name...
 1544  */
 1545 static struct nd_pfxrouter *
 1546 find_pfxlist_reachable_router(struct nd_prefix *pr)
 1547 {
 1548         struct nd_pfxrouter *pfxrtr;
 1549         struct llentry *ln;
 1550         int canreach;
 1551 
 1552         ND6_LOCK_ASSERT();
 1553 
 1554         LIST_FOREACH(pfxrtr, &pr->ndpr_advrtrs, pfr_entry) {
 1555                 IF_AFDATA_RLOCK(pfxrtr->router->ifp);
 1556                 ln = nd6_lookup(&pfxrtr->router->rtaddr, 0, pfxrtr->router->ifp);
 1557                 IF_AFDATA_RUNLOCK(pfxrtr->router->ifp);
 1558                 if (ln == NULL)
 1559                         continue;
 1560                 canreach = ND6_IS_LLINFO_PROBREACH(ln);
 1561                 LLE_RUNLOCK(ln);
 1562                 if (canreach)
 1563                         break;
 1564         }
 1565         return (pfxrtr);
 1566 }
 1567 
 1568 /*
 1569  * Check if each prefix in the prefix list has at least one available router
 1570  * that advertised the prefix (a router is "available" if its neighbor cache
 1571  * entry is reachable or probably reachable).
 1572  * If the check fails, the prefix may be off-link, because, for example,
 1573  * we have moved from the network but the lifetime of the prefix has not
 1574  * expired yet.  So we should not use the prefix if there is another prefix
 1575  * that has an available router.
 1576  * But, if there is no prefix that has an available router, we still regard
 1577  * all the prefixes as on-link.  This is because we can't tell if all the
 1578  * routers are simply dead or if we really moved from the network and there
 1579  * is no router around us.
 1580  */
 1581 void
 1582 pfxlist_onlink_check(void)
 1583 {
 1584         struct nd_prefix *pr;
 1585         struct in6_ifaddr *ifa;
 1586         struct nd_defrouter *dr;
 1587         struct nd_pfxrouter *pfxrtr = NULL;
 1588         struct rm_priotracker in6_ifa_tracker;
 1589         uint64_t genid;
 1590         uint32_t flags;
 1591 
 1592         ND6_ONLINK_LOCK();
 1593         ND6_RLOCK();
 1594 
 1595         /*
 1596          * Check if there is a prefix that has a reachable advertising
 1597          * router.
 1598          */
 1599         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 1600                 if (pr->ndpr_raf_onlink && find_pfxlist_reachable_router(pr))
 1601                         break;
 1602         }
 1603 
 1604         /*
 1605          * If we have no such prefix, check whether we still have a router
 1606          * that does not advertise any prefixes.
 1607          */
 1608         if (pr == NULL) {
 1609                 TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
 1610                         struct nd_prefix *pr0;
 1611 
 1612                         LIST_FOREACH(pr0, &V_nd_prefix, ndpr_entry) {
 1613                                 if ((pfxrtr = pfxrtr_lookup(pr0, dr)) != NULL)
 1614                                         break;
 1615                         }
 1616                         if (pfxrtr != NULL)
 1617                                 break;
 1618                 }
 1619         }
 1620         if (pr != NULL || (!TAILQ_EMPTY(&V_nd_defrouter) && pfxrtr == NULL)) {
 1621                 /*
 1622                  * There is at least one prefix that has a reachable router,
 1623                  * or at least a router which probably does not advertise
 1624                  * any prefixes.  The latter would be the case when we move
 1625                  * to a new link where we have a router that does not provide
 1626                  * prefixes and we configure an address by hand.
 1627                  * Detach prefixes which have no reachable advertising
 1628                  * router, and attach other prefixes.
 1629                  */
 1630                 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 1631                         /* XXX: a link-local prefix should never be detached */
 1632                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
 1633                             pr->ndpr_raf_onlink == 0 ||
 1634                             pr->ndpr_raf_auto == 0)
 1635                                 continue;
 1636 
 1637                         if ((pr->ndpr_stateflags & NDPRF_DETACHED) == 0 &&
 1638                             find_pfxlist_reachable_router(pr) == NULL)
 1639                                 pr->ndpr_stateflags |= NDPRF_DETACHED;
 1640                         else if ((pr->ndpr_stateflags & NDPRF_DETACHED) != 0 &&
 1641                             find_pfxlist_reachable_router(pr) != NULL)
 1642                                 pr->ndpr_stateflags &= ~NDPRF_DETACHED;
 1643                 }
 1644         } else {
 1645                 /* there is no prefix that has a reachable router */
 1646                 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 1647                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
 1648                             pr->ndpr_raf_onlink == 0 ||
 1649                             pr->ndpr_raf_auto == 0)
 1650                                 continue;
 1651                         pr->ndpr_stateflags &= ~NDPRF_DETACHED;
 1652                 }
 1653         }
 1654 
 1655         /*
 1656          * Remove each interface route associated with a (just) detached
 1657          * prefix, and reinstall the interface route for a (just) attached
 1658          * prefix.  Note that all attempt of reinstallation does not
 1659          * necessarily success, when a same prefix is shared among multiple
 1660          * interfaces.  Such cases will be handled in nd6_prefix_onlink,
 1661          * so we don't have to care about them.
 1662          */
 1663 restart:
 1664         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 1665                 char ip6buf[INET6_ADDRSTRLEN];
 1666                 int e;
 1667 
 1668                 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr) ||
 1669                     pr->ndpr_raf_onlink == 0 ||
 1670                     pr->ndpr_raf_auto == 0)
 1671                         continue;
 1672 
 1673                 flags = pr->ndpr_stateflags & (NDPRF_DETACHED | NDPRF_ONLINK);
 1674                 if (flags == 0 || flags == (NDPRF_DETACHED | NDPRF_ONLINK)) {
 1675                         genid = V_nd6_list_genid;
 1676                         ND6_RUNLOCK();
 1677                         if ((flags & NDPRF_ONLINK) != 0 &&
 1678                             (e = nd6_prefix_offlink(pr)) != 0) {
 1679                                 nd6log((LOG_ERR,
 1680                                     "pfxlist_onlink_check: failed to "
 1681                                     "make %s/%d offlink, errno=%d\n",
 1682                                     ip6_sprintf(ip6buf,
 1683                                             &pr->ndpr_prefix.sin6_addr),
 1684                                             pr->ndpr_plen, e));
 1685                         } else if ((flags & NDPRF_ONLINK) == 0 &&
 1686                             (e = nd6_prefix_onlink(pr)) != 0) {
 1687                                 nd6log((LOG_ERR,
 1688                                     "pfxlist_onlink_check: failed to "
 1689                                     "make %s/%d onlink, errno=%d\n",
 1690                                     ip6_sprintf(ip6buf,
 1691                                             &pr->ndpr_prefix.sin6_addr),
 1692                                             pr->ndpr_plen, e));
 1693                         }
 1694                         ND6_RLOCK();
 1695                         if (genid != V_nd6_list_genid)
 1696                                 goto restart;
 1697                 }
 1698         }
 1699 
 1700         /*
 1701          * Changes on the prefix status might affect address status as well.
 1702          * Make sure that all addresses derived from an attached prefix are
 1703          * attached, and that all addresses derived from a detached prefix are
 1704          * detached.  Note, however, that a manually configured address should
 1705          * always be attached.
 1706          * The precise detection logic is same as the one for prefixes.
 1707          */
 1708         IN6_IFADDR_RLOCK(&in6_ifa_tracker);
 1709         TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
 1710                 if (!(ifa->ia6_flags & IN6_IFF_AUTOCONF))
 1711                         continue;
 1712 
 1713                 if (ifa->ia6_ndpr == NULL) {
 1714                         /*
 1715                          * This can happen when we first configure the address
 1716                          * (i.e. the address exists, but the prefix does not).
 1717                          * XXX: complicated relationships...
 1718                          */
 1719                         continue;
 1720                 }
 1721 
 1722                 if (find_pfxlist_reachable_router(ifa->ia6_ndpr))
 1723                         break;
 1724         }
 1725         if (ifa) {
 1726                 TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
 1727                         if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1728                                 continue;
 1729 
 1730                         if (ifa->ia6_ndpr == NULL) /* XXX: see above. */
 1731                                 continue;
 1732 
 1733                         if (find_pfxlist_reachable_router(ifa->ia6_ndpr)) {
 1734                                 if (ifa->ia6_flags & IN6_IFF_DETACHED) {
 1735                                         ifa->ia6_flags &= ~IN6_IFF_DETACHED;
 1736                                         ifa->ia6_flags |= IN6_IFF_TENTATIVE;
 1737                                         nd6_dad_start((struct ifaddr *)ifa, 0);
 1738                                 }
 1739                         } else {
 1740                                 ifa->ia6_flags |= IN6_IFF_DETACHED;
 1741                         }
 1742                 }
 1743         } else {
 1744                 TAILQ_FOREACH(ifa, &V_in6_ifaddrhead, ia_link) {
 1745                         if ((ifa->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1746                                 continue;
 1747 
 1748                         if (ifa->ia6_flags & IN6_IFF_DETACHED) {
 1749                                 ifa->ia6_flags &= ~IN6_IFF_DETACHED;
 1750                                 ifa->ia6_flags |= IN6_IFF_TENTATIVE;
 1751                                 /* Do we need a delay in this case? */
 1752                                 nd6_dad_start((struct ifaddr *)ifa, 0);
 1753                         }
 1754                 }
 1755         }
 1756         IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
 1757         ND6_RUNLOCK();
 1758         ND6_ONLINK_UNLOCK();
 1759 }
 1760 
 1761 static int
 1762 nd6_prefix_onlink_rtrequest(struct nd_prefix *pr, struct ifaddr *ifa)
 1763 {
 1764         static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
 1765         struct rib_head *rnh;
 1766         struct rtentry *rt;
 1767         struct sockaddr_in6 mask6;
 1768         u_long rtflags;
 1769         int error, a_failure, fibnum, maxfib;
 1770 
 1771         /*
 1772          * in6_ifinit() sets nd6_rtrequest to ifa_rtrequest for all ifaddrs.
 1773          * ifa->ifa_rtrequest = nd6_rtrequest;
 1774          */
 1775         bzero(&mask6, sizeof(mask6));
 1776         mask6.sin6_len = sizeof(mask6);
 1777         mask6.sin6_addr = pr->ndpr_mask;
 1778         rtflags = (ifa->ifa_flags & ~IFA_RTSELF) | RTF_UP;
 1779 
 1780         if(V_rt_add_addr_allfibs) {
 1781                 fibnum = 0;
 1782                 maxfib = rt_numfibs;
 1783         } else {
 1784                 fibnum = ifa->ifa_ifp->if_fib;
 1785                 maxfib = fibnum + 1;
 1786         }
 1787         a_failure = 0;
 1788         for (; fibnum < maxfib; fibnum++) {
 1789 
 1790                 rt = NULL;
 1791                 error = in6_rtrequest(RTM_ADD,
 1792                     (struct sockaddr *)&pr->ndpr_prefix, ifa->ifa_addr,
 1793                     (struct sockaddr *)&mask6, rtflags, &rt, fibnum);
 1794                 if (error == 0) {
 1795                         KASSERT(rt != NULL, ("%s: in6_rtrequest return no "
 1796                             "error(%d) but rt is NULL, pr=%p, ifa=%p", __func__,
 1797                             error, pr, ifa));
 1798 
 1799                         rnh = rt_tables_get_rnh(rt->rt_fibnum, AF_INET6);
 1800                         /* XXX what if rhn == NULL? */
 1801                         RIB_WLOCK(rnh);
 1802                         RT_LOCK(rt);
 1803                         if (rt_setgate(rt, rt_key(rt),
 1804                             (struct sockaddr *)&null_sdl) == 0) {
 1805                                 struct sockaddr_dl *dl;
 1806 
 1807                                 dl = (struct sockaddr_dl *)rt->rt_gateway;
 1808                                 dl->sdl_type = rt->rt_ifp->if_type;
 1809                                 dl->sdl_index = rt->rt_ifp->if_index;
 1810                         }
 1811                         RIB_WUNLOCK(rnh);
 1812                         nd6_rtmsg(RTM_ADD, rt);
 1813                         RT_UNLOCK(rt);
 1814                         pr->ndpr_stateflags |= NDPRF_ONLINK;
 1815                 } else {
 1816                         char ip6buf[INET6_ADDRSTRLEN];
 1817                         char ip6bufg[INET6_ADDRSTRLEN];
 1818                         char ip6bufm[INET6_ADDRSTRLEN];
 1819                         struct sockaddr_in6 *sin6;
 1820 
 1821                         sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 1822                         nd6log((LOG_ERR, "nd6_prefix_onlink: failed to add "
 1823                             "route for a prefix (%s/%d) on %s, gw=%s, mask=%s, "
 1824                             "flags=%lx errno = %d\n",
 1825                             ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1826                             pr->ndpr_plen, if_name(pr->ndpr_ifp),
 1827                             ip6_sprintf(ip6bufg, &sin6->sin6_addr),
 1828                             ip6_sprintf(ip6bufm, &mask6.sin6_addr),
 1829                             rtflags, error));
 1830 
 1831                         /* Save last error to return, see rtinit(). */
 1832                         a_failure = error;
 1833                 }
 1834 
 1835                 if (rt != NULL) {
 1836                         RT_LOCK(rt);
 1837                         RT_REMREF(rt);
 1838                         RT_UNLOCK(rt);
 1839                 }
 1840         }
 1841 
 1842         /* Return the last error we got. */
 1843         return (a_failure);
 1844 }
 1845 
 1846 int
 1847 nd6_prefix_onlink(struct nd_prefix *pr)
 1848 {
 1849         struct ifaddr *ifa;
 1850         struct ifnet *ifp = pr->ndpr_ifp;
 1851         struct nd_prefix *opr;
 1852         char ip6buf[INET6_ADDRSTRLEN];
 1853         int error;
 1854 
 1855         ND6_ONLINK_LOCK_ASSERT();
 1856         ND6_UNLOCK_ASSERT();
 1857 
 1858         if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0)
 1859                 return (EEXIST);
 1860 
 1861         /*
 1862          * Add the interface route associated with the prefix.  Before
 1863          * installing the route, check if there's the same prefix on another
 1864          * interface, and the prefix has already installed the interface route.
 1865          * Although such a configuration is expected to be rare, we explicitly
 1866          * allow it.
 1867          */
 1868         ND6_RLOCK();
 1869         LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
 1870                 if (opr == pr)
 1871                         continue;
 1872 
 1873                 if ((opr->ndpr_stateflags & NDPRF_ONLINK) == 0)
 1874                         continue;
 1875 
 1876                 if (!V_rt_add_addr_allfibs &&
 1877                     opr->ndpr_ifp->if_fib != pr->ndpr_ifp->if_fib)
 1878                         continue;
 1879 
 1880                 if (opr->ndpr_plen == pr->ndpr_plen &&
 1881                     in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
 1882                     &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
 1883                         ND6_RUNLOCK();
 1884                         return (0);
 1885                 }
 1886         }
 1887         ND6_RUNLOCK();
 1888 
 1889         /*
 1890          * We prefer link-local addresses as the associated interface address.
 1891          */
 1892         /* search for a link-local addr */
 1893         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
 1894             IN6_IFF_NOTREADY | IN6_IFF_ANYCAST);
 1895         if (ifa == NULL) {
 1896                 /* XXX: freebsd does not have ifa_ifwithaf */
 1897                 IF_ADDR_RLOCK(ifp);
 1898                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1899                         if (ifa->ifa_addr->sa_family == AF_INET6) {
 1900                                 ifa_ref(ifa);
 1901                                 break;
 1902                         }
 1903                 }
 1904                 IF_ADDR_RUNLOCK(ifp);
 1905                 /* should we care about ia6_flags? */
 1906         }
 1907         if (ifa == NULL) {
 1908                 /*
 1909                  * This can still happen, when, for example, we receive an RA
 1910                  * containing a prefix with the L bit set and the A bit clear,
 1911                  * after removing all IPv6 addresses on the receiving
 1912                  * interface.  This should, of course, be rare though.
 1913                  */
 1914                 nd6log((LOG_NOTICE,
 1915                     "nd6_prefix_onlink: failed to find any ifaddr"
 1916                     " to add route for a prefix(%s/%d) on %s\n",
 1917                     ip6_sprintf(ip6buf, &pr->ndpr_prefix.sin6_addr),
 1918                     pr->ndpr_plen, if_name(ifp)));
 1919                 return (0);
 1920         }
 1921 
 1922         error = nd6_prefix_onlink_rtrequest(pr, ifa);
 1923 
 1924         if (ifa != NULL)
 1925                 ifa_free(ifa);
 1926 
 1927         return (error);
 1928 }
 1929 
 1930 int
 1931 nd6_prefix_offlink(struct nd_prefix *pr)
 1932 {
 1933         int error = 0;
 1934         struct ifnet *ifp = pr->ndpr_ifp;
 1935         struct nd_prefix *opr;
 1936         struct sockaddr_in6 sa6, mask6;
 1937         struct rtentry *rt;
 1938         char ip6buf[INET6_ADDRSTRLEN];
 1939         uint64_t genid;
 1940         int fibnum, maxfib, a_failure;
 1941 
 1942         ND6_ONLINK_LOCK_ASSERT();
 1943         ND6_UNLOCK_ASSERT();
 1944 
 1945         if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
 1946                 return (EEXIST);
 1947 
 1948         bzero(&sa6, sizeof(sa6));
 1949         sa6.sin6_family = AF_INET6;
 1950         sa6.sin6_len = sizeof(sa6);
 1951         bcopy(&pr->ndpr_prefix.sin6_addr, &sa6.sin6_addr,
 1952             sizeof(struct in6_addr));
 1953         bzero(&mask6, sizeof(mask6));
 1954         mask6.sin6_family = AF_INET6;
 1955         mask6.sin6_len = sizeof(sa6);
 1956         bcopy(&pr->ndpr_mask, &mask6.sin6_addr, sizeof(struct in6_addr));
 1957 
 1958         if (V_rt_add_addr_allfibs) {
 1959                 fibnum = 0;
 1960                 maxfib = rt_numfibs;
 1961         } else {
 1962                 fibnum = ifp->if_fib;
 1963                 maxfib = fibnum + 1;
 1964         }
 1965 
 1966         a_failure = 0;
 1967         for (; fibnum < maxfib; fibnum++) {
 1968                 rt = NULL;
 1969                 error = in6_rtrequest(RTM_DELETE, (struct sockaddr *)&sa6, NULL,
 1970                     (struct sockaddr *)&mask6, 0, &rt, fibnum);
 1971                 if (error == 0) {
 1972                         /* report the route deletion to the routing socket. */
 1973                         if (rt != NULL)
 1974                                 nd6_rtmsg(RTM_DELETE, rt);
 1975                 } else {
 1976                         /* Save last error to return, see rtinit(). */
 1977                         a_failure = error;
 1978                 }
 1979                 if (rt != NULL) {
 1980                         RTFREE(rt);
 1981                 }
 1982         }
 1983         error = a_failure;
 1984         a_failure = 1;
 1985         if (error == 0) {
 1986                 pr->ndpr_stateflags &= ~NDPRF_ONLINK;
 1987 
 1988                 /*
 1989                  * There might be the same prefix on another interface,
 1990                  * the prefix which could not be on-link just because we have
 1991                  * the interface route (see comments in nd6_prefix_onlink).
 1992                  * If there's one, try to make the prefix on-link on the
 1993                  * interface.
 1994                  */
 1995                 ND6_RLOCK();
 1996 restart:
 1997                 LIST_FOREACH(opr, &V_nd_prefix, ndpr_entry) {
 1998                         /*
 1999                          * KAME specific: detached prefixes should not be
 2000                          * on-link.
 2001                          */
 2002                         if (opr == pr || (opr->ndpr_stateflags &
 2003                             (NDPRF_ONLINK | NDPRF_DETACHED)) != 0)
 2004                                 continue;
 2005 
 2006                         if (opr->ndpr_plen == pr->ndpr_plen &&
 2007                             in6_are_prefix_equal(&pr->ndpr_prefix.sin6_addr,
 2008                             &opr->ndpr_prefix.sin6_addr, pr->ndpr_plen)) {
 2009                                 int e;
 2010 
 2011                                 genid = V_nd6_list_genid;
 2012                                 ND6_RUNLOCK();
 2013                                 if ((e = nd6_prefix_onlink(opr)) != 0) {
 2014                                         nd6log((LOG_ERR,
 2015                                             "nd6_prefix_offlink: failed to "
 2016                                             "recover a prefix %s/%d from %s "
 2017                                             "to %s (errno = %d)\n",
 2018                                             ip6_sprintf(ip6buf,
 2019                                                 &opr->ndpr_prefix.sin6_addr),
 2020                                             opr->ndpr_plen, if_name(ifp),
 2021                                             if_name(opr->ndpr_ifp), e));
 2022                                 } else
 2023                                         a_failure = 0;
 2024                                 ND6_RLOCK();
 2025                                 if (genid != V_nd6_list_genid)
 2026                                         goto restart;
 2027                         }
 2028                 }
 2029                 ND6_RUNLOCK();
 2030         } else {
 2031                 /* XXX: can we still set the NDPRF_ONLINK flag? */
 2032                 nd6log((LOG_ERR,
 2033                     "nd6_prefix_offlink: failed to delete route: "
 2034                     "%s/%d on %s (errno = %d)\n",
 2035                     ip6_sprintf(ip6buf, &sa6.sin6_addr), pr->ndpr_plen,
 2036                     if_name(ifp), error));
 2037         }
 2038 
 2039         if (a_failure)
 2040                 lltable_prefix_free(AF_INET6, (struct sockaddr *)&sa6,
 2041                     (struct sockaddr *)&mask6, LLE_STATIC);
 2042 
 2043         return (error);
 2044 }
 2045 
 2046 static struct in6_ifaddr *
 2047 in6_ifadd(struct nd_prefixctl *pr, int mcast)
 2048 {
 2049         struct ifnet *ifp = pr->ndpr_ifp;
 2050         struct ifaddr *ifa;
 2051         struct in6_aliasreq ifra;
 2052         struct in6_ifaddr *ia, *ib;
 2053         int error, plen0;
 2054         struct in6_addr mask;
 2055         int prefixlen = pr->ndpr_plen;
 2056         int updateflags;
 2057         char ip6buf[INET6_ADDRSTRLEN];
 2058 
 2059         in6_prefixlen2mask(&mask, prefixlen);
 2060 
 2061         /*
 2062          * find a link-local address (will be interface ID).
 2063          * Is it really mandatory? Theoretically, a global or a site-local
 2064          * address can be configured without a link-local address, if we
 2065          * have a unique interface identifier...
 2066          *
 2067          * it is not mandatory to have a link-local address, we can generate
 2068          * interface identifier on the fly.  we do this because:
 2069          * (1) it should be the easiest way to find interface identifier.
 2070          * (2) RFC2462 5.4 suggesting the use of the same interface identifier
 2071          * for multiple addresses on a single interface, and possible shortcut
 2072          * of DAD.  we omitted DAD for this reason in the past.
 2073          * (3) a user can prevent autoconfiguration of global address
 2074          * by removing link-local address by hand (this is partly because we
 2075          * don't have other way to control the use of IPv6 on an interface.
 2076          * this has been our design choice - cf. NRL's "ifconfig auto").
 2077          * (4) it is easier to manage when an interface has addresses
 2078          * with the same interface identifier, than to have multiple addresses
 2079          * with different interface identifiers.
 2080          */
 2081         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp, 0); /* 0 is OK? */
 2082         if (ifa)
 2083                 ib = (struct in6_ifaddr *)ifa;
 2084         else
 2085                 return NULL;
 2086 
 2087         /* prefixlen + ifidlen must be equal to 128 */
 2088         plen0 = in6_mask2len(&ib->ia_prefixmask.sin6_addr, NULL);
 2089         if (prefixlen != plen0) {
 2090                 ifa_free(ifa);
 2091                 nd6log((LOG_INFO, "in6_ifadd: wrong prefixlen for %s "
 2092                     "(prefix=%d ifid=%d)\n",
 2093                     if_name(ifp), prefixlen, 128 - plen0));
 2094                 return NULL;
 2095         }
 2096 
 2097         /* make ifaddr */
 2098         in6_prepare_ifra(&ifra, &pr->ndpr_prefix.sin6_addr, &mask);
 2099 
 2100         IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr, &mask);
 2101         /* interface ID */
 2102         ifra.ifra_addr.sin6_addr.s6_addr32[0] |=
 2103             (ib->ia_addr.sin6_addr.s6_addr32[0] & ~mask.s6_addr32[0]);
 2104         ifra.ifra_addr.sin6_addr.s6_addr32[1] |=
 2105             (ib->ia_addr.sin6_addr.s6_addr32[1] & ~mask.s6_addr32[1]);
 2106         ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
 2107             (ib->ia_addr.sin6_addr.s6_addr32[2] & ~mask.s6_addr32[2]);
 2108         ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
 2109             (ib->ia_addr.sin6_addr.s6_addr32[3] & ~mask.s6_addr32[3]);
 2110         ifa_free(ifa);
 2111 
 2112         /* lifetimes. */
 2113         ifra.ifra_lifetime.ia6t_vltime = pr->ndpr_vltime;
 2114         ifra.ifra_lifetime.ia6t_pltime = pr->ndpr_pltime;
 2115 
 2116         /* XXX: scope zone ID? */
 2117 
 2118         ifra.ifra_flags |= IN6_IFF_AUTOCONF; /* obey autoconf */
 2119 
 2120         /*
 2121          * Make sure that we do not have this address already.  This should
 2122          * usually not happen, but we can still see this case, e.g., if we
 2123          * have manually configured the exact address to be configured.
 2124          */
 2125         ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
 2126             &ifra.ifra_addr.sin6_addr);
 2127         if (ifa != NULL) {
 2128                 ifa_free(ifa);
 2129                 /* this should be rare enough to make an explicit log */
 2130                 log(LOG_INFO, "in6_ifadd: %s is already configured\n",
 2131                     ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr));
 2132                 return (NULL);
 2133         }
 2134 
 2135         /*
 2136          * Allocate ifaddr structure, link into chain, etc.
 2137          * If we are going to create a new address upon receiving a multicasted
 2138          * RA, we need to impose a random delay before starting DAD.
 2139          * [draft-ietf-ipv6-rfc2462bis-02.txt, Section 5.4.2]
 2140          */
 2141         updateflags = 0;
 2142         if (mcast)
 2143                 updateflags |= IN6_IFAUPDATE_DADDELAY;
 2144         if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0) {
 2145                 nd6log((LOG_ERR,
 2146                     "in6_ifadd: failed to make ifaddr %s on %s (errno=%d)\n",
 2147                     ip6_sprintf(ip6buf, &ifra.ifra_addr.sin6_addr),
 2148                     if_name(ifp), error));
 2149                 return (NULL);  /* ifaddr must not have been allocated. */
 2150         }
 2151 
 2152         ia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
 2153         /*
 2154          * XXXRW: Assumption of non-NULLness here might not be true with
 2155          * fine-grained locking -- should we validate it?  Or just return
 2156          * earlier ifa rather than looking it up again?
 2157          */
 2158         return (ia);            /* this is always non-NULL  and referenced. */
 2159 }
 2160 
 2161 /*
 2162  * ia0 - corresponding public address
 2163  */
 2164 int
 2165 in6_tmpifadd(const struct in6_ifaddr *ia0, int forcegen, int delay)
 2166 {
 2167         struct ifnet *ifp = ia0->ia_ifa.ifa_ifp;
 2168         struct in6_ifaddr *newia;
 2169         struct in6_aliasreq ifra;
 2170         int error;
 2171         int trylimit = 3;       /* XXX: adhoc value */
 2172         int updateflags;
 2173         u_int32_t randid[2];
 2174         time_t vltime0, pltime0;
 2175 
 2176         in6_prepare_ifra(&ifra, &ia0->ia_addr.sin6_addr,
 2177             &ia0->ia_prefixmask.sin6_addr);
 2178 
 2179         ifra.ifra_addr = ia0->ia_addr;  /* XXX: do we need this ? */
 2180         /* clear the old IFID */
 2181         IN6_MASK_ADDR(&ifra.ifra_addr.sin6_addr,
 2182             &ifra.ifra_prefixmask.sin6_addr);
 2183 
 2184   again:
 2185         if (in6_get_tmpifid(ifp, (u_int8_t *)randid,
 2186             (const u_int8_t *)&ia0->ia_addr.sin6_addr.s6_addr[8], forcegen)) {
 2187                 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to find a good "
 2188                     "random IFID\n"));
 2189                 return (EINVAL);
 2190         }
 2191         ifra.ifra_addr.sin6_addr.s6_addr32[2] |=
 2192             (randid[0] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[2]));
 2193         ifra.ifra_addr.sin6_addr.s6_addr32[3] |=
 2194             (randid[1] & ~(ifra.ifra_prefixmask.sin6_addr.s6_addr32[3]));
 2195 
 2196         /*
 2197          * in6_get_tmpifid() quite likely provided a unique interface ID.
 2198          * However, we may still have a chance to see collision, because
 2199          * there may be a time lag between generation of the ID and generation
 2200          * of the address.  So, we'll do one more sanity check.
 2201          */
 2202 
 2203         if (in6_localip(&ifra.ifra_addr.sin6_addr) != 0) {
 2204                 if (trylimit-- > 0) {
 2205                         forcegen = 1;
 2206                         goto again;
 2207                 }
 2208 
 2209                 /* Give up.  Something strange should have happened.  */
 2210                 nd6log((LOG_NOTICE, "in6_tmpifadd: failed to "
 2211                     "find a unique random IFID\n"));
 2212                 return (EEXIST);
 2213         }
 2214 
 2215         /*
 2216          * The Valid Lifetime is the lower of the Valid Lifetime of the
 2217          * public address or TEMP_VALID_LIFETIME.
 2218          * The Preferred Lifetime is the lower of the Preferred Lifetime
 2219          * of the public address or TEMP_PREFERRED_LIFETIME -
 2220          * DESYNC_FACTOR.
 2221          */
 2222         if (ia0->ia6_lifetime.ia6t_vltime != ND6_INFINITE_LIFETIME) {
 2223                 vltime0 = IFA6_IS_INVALID(ia0) ? 0 :
 2224                     (ia0->ia6_lifetime.ia6t_vltime -
 2225                     (time_uptime - ia0->ia6_updatetime));
 2226                 if (vltime0 > V_ip6_temp_valid_lifetime)
 2227                         vltime0 = V_ip6_temp_valid_lifetime;
 2228         } else
 2229                 vltime0 = V_ip6_temp_valid_lifetime;
 2230         if (ia0->ia6_lifetime.ia6t_pltime != ND6_INFINITE_LIFETIME) {
 2231                 pltime0 = IFA6_IS_DEPRECATED(ia0) ? 0 :
 2232                     (ia0->ia6_lifetime.ia6t_pltime -
 2233                     (time_uptime - ia0->ia6_updatetime));
 2234                 if (pltime0 > V_ip6_temp_preferred_lifetime - V_ip6_desync_factor){
 2235                         pltime0 = V_ip6_temp_preferred_lifetime -
 2236                             V_ip6_desync_factor;
 2237                 }
 2238         } else
 2239                 pltime0 = V_ip6_temp_preferred_lifetime - V_ip6_desync_factor;
 2240         ifra.ifra_lifetime.ia6t_vltime = vltime0;
 2241         ifra.ifra_lifetime.ia6t_pltime = pltime0;
 2242 
 2243         /*
 2244          * A temporary address is created only if this calculated Preferred
 2245          * Lifetime is greater than REGEN_ADVANCE time units.
 2246          */
 2247         if (ifra.ifra_lifetime.ia6t_pltime <= V_ip6_temp_regen_advance)
 2248                 return (0);
 2249 
 2250         /* XXX: scope zone ID? */
 2251 
 2252         ifra.ifra_flags |= (IN6_IFF_AUTOCONF|IN6_IFF_TEMPORARY);
 2253 
 2254         /* allocate ifaddr structure, link into chain, etc. */
 2255         updateflags = 0;
 2256         if (delay)
 2257                 updateflags |= IN6_IFAUPDATE_DADDELAY;
 2258         if ((error = in6_update_ifa(ifp, &ifra, NULL, updateflags)) != 0)
 2259                 return (error);
 2260 
 2261         newia = in6ifa_ifpwithaddr(ifp, &ifra.ifra_addr.sin6_addr);
 2262         if (newia == NULL) {    /* XXX: can it happen? */
 2263                 nd6log((LOG_ERR,
 2264                     "in6_tmpifadd: ifa update succeeded, but we got "
 2265                     "no ifaddr\n"));
 2266                 return (EINVAL); /* XXX */
 2267         }
 2268         newia->ia6_ndpr = ia0->ia6_ndpr;
 2269         newia->ia6_ndpr->ndpr_addrcnt++;
 2270         ifa_free(&newia->ia_ifa);
 2271 
 2272         /*
 2273          * A newly added address might affect the status of other addresses.
 2274          * XXX: when the temporary address is generated with a new public
 2275          * address, the onlink check is redundant.  However, it would be safe
 2276          * to do the check explicitly everywhere a new address is generated,
 2277          * and, in fact, we surely need the check when we create a new
 2278          * temporary address due to deprecation of an old temporary address.
 2279          */
 2280         pfxlist_onlink_check();
 2281 
 2282         return (0);
 2283 }
 2284 
 2285 static int
 2286 in6_init_prefix_ltimes(struct nd_prefix *ndpr)
 2287 {
 2288         if (ndpr->ndpr_pltime == ND6_INFINITE_LIFETIME)
 2289                 ndpr->ndpr_preferred = 0;
 2290         else
 2291                 ndpr->ndpr_preferred = time_uptime + ndpr->ndpr_pltime;
 2292         if (ndpr->ndpr_vltime == ND6_INFINITE_LIFETIME)
 2293                 ndpr->ndpr_expire = 0;
 2294         else
 2295                 ndpr->ndpr_expire = time_uptime + ndpr->ndpr_vltime;
 2296 
 2297         return 0;
 2298 }
 2299 
 2300 static void
 2301 in6_init_address_ltimes(struct nd_prefix *new, struct in6_addrlifetime *lt6)
 2302 {
 2303         /* init ia6t_expire */
 2304         if (lt6->ia6t_vltime == ND6_INFINITE_LIFETIME)
 2305                 lt6->ia6t_expire = 0;
 2306         else {
 2307                 lt6->ia6t_expire = time_uptime;
 2308                 lt6->ia6t_expire += lt6->ia6t_vltime;
 2309         }
 2310 
 2311         /* init ia6t_preferred */
 2312         if (lt6->ia6t_pltime == ND6_INFINITE_LIFETIME)
 2313                 lt6->ia6t_preferred = 0;
 2314         else {
 2315                 lt6->ia6t_preferred = time_uptime;
 2316                 lt6->ia6t_preferred += lt6->ia6t_pltime;
 2317         }
 2318 }
 2319 
 2320 /*
 2321  * Delete all the routing table entries that use the specified gateway.
 2322  * XXX: this function causes search through all entries of routing table, so
 2323  * it shouldn't be called when acting as a router.
 2324  */
 2325 void
 2326 rt6_flush(struct in6_addr *gateway, struct ifnet *ifp)
 2327 {
 2328 
 2329         /* We'll care only link-local addresses */
 2330         if (!IN6_IS_ADDR_LINKLOCAL(gateway))
 2331                 return;
 2332 
 2333         /* XXX Do we really need to walk any but the default FIB? */
 2334         rt_foreach_fib_walk_del(AF_INET6, rt6_deleteroute, (void *)gateway);
 2335 }
 2336 
 2337 static int
 2338 rt6_deleteroute(const struct rtentry *rt, void *arg)
 2339 {
 2340 #define SIN6(s) ((struct sockaddr_in6 *)s)
 2341         struct in6_addr *gate = (struct in6_addr *)arg;
 2342 
 2343         if (rt->rt_gateway == NULL || rt->rt_gateway->sa_family != AF_INET6)
 2344                 return (0);
 2345 
 2346         if (!IN6_ARE_ADDR_EQUAL(gate, &SIN6(rt->rt_gateway)->sin6_addr)) {
 2347                 return (0);
 2348         }
 2349 
 2350         /*
 2351          * Do not delete a static route.
 2352          * XXX: this seems to be a bit ad-hoc. Should we consider the
 2353          * 'cloned' bit instead?
 2354          */
 2355         if ((rt->rt_flags & RTF_STATIC) != 0)
 2356                 return (0);
 2357 
 2358         /*
 2359          * We delete only host route. This means, in particular, we don't
 2360          * delete default route.
 2361          */
 2362         if ((rt->rt_flags & RTF_HOST) == 0)
 2363                 return (0);
 2364 
 2365         return (1);
 2366 #undef SIN6
 2367 }
 2368 
 2369 int
 2370 nd6_setdefaultiface(int ifindex)
 2371 {
 2372         int error = 0;
 2373 
 2374         if (ifindex < 0 || V_if_index < ifindex)
 2375                 return (EINVAL);
 2376         if (ifindex != 0 && !ifnet_byindex(ifindex))
 2377                 return (EINVAL);
 2378 
 2379         if (V_nd6_defifindex != ifindex) {
 2380                 V_nd6_defifindex = ifindex;
 2381                 if (V_nd6_defifindex > 0)
 2382                         V_nd6_defifp = ifnet_byindex(V_nd6_defifindex);
 2383                 else
 2384                         V_nd6_defifp = NULL;
 2385 
 2386                 /*
 2387                  * Our current implementation assumes one-to-one maping between
 2388                  * interfaces and links, so it would be natural to use the
 2389                  * default interface as the default link.
 2390                  */
 2391                 scope6_setdefault(V_nd6_defifp);
 2392         }
 2393 
 2394         return (error);
 2395 }

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