The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/nd6.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.c,v 1.144 2001/05/24 07:44:00 itojun Exp $
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD: releng/11.2/sys/netinet6/nd6.c 331722 2018-03-29 02:50:57Z eadler $");
   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/callout.h>
   41 #include <sys/lock.h>
   42 #include <sys/malloc.h>
   43 #include <sys/mbuf.h>
   44 #include <sys/mutex.h>
   45 #include <sys/socket.h>
   46 #include <sys/sockio.h>
   47 #include <sys/time.h>
   48 #include <sys/kernel.h>
   49 #include <sys/protosw.h>
   50 #include <sys/errno.h>
   51 #include <sys/syslog.h>
   52 #include <sys/rwlock.h>
   53 #include <sys/queue.h>
   54 #include <sys/sdt.h>
   55 #include <sys/sysctl.h>
   56 
   57 #include <net/if.h>
   58 #include <net/if_var.h>
   59 #include <net/if_arc.h>
   60 #include <net/if_dl.h>
   61 #include <net/if_types.h>
   62 #include <net/iso88025.h>
   63 #include <net/fddi.h>
   64 #include <net/route.h>
   65 #include <net/vnet.h>
   66 
   67 #include <netinet/in.h>
   68 #include <netinet/in_kdtrace.h>
   69 #include <net/if_llatbl.h>
   70 #include <netinet/if_ether.h>
   71 #include <netinet6/in6_var.h>
   72 #include <netinet/ip6.h>
   73 #include <netinet6/ip6_var.h>
   74 #include <netinet6/scope6_var.h>
   75 #include <netinet6/nd6.h>
   76 #include <netinet6/in6_ifattach.h>
   77 #include <netinet/icmp6.h>
   78 #include <netinet6/send.h>
   79 
   80 #include <sys/limits.h>
   81 
   82 #include <security/mac/mac_framework.h>
   83 
   84 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
   85 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
   86 
   87 #define SIN6(s) ((const struct sockaddr_in6 *)(s))
   88 
   89 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
   90 
   91 /* timer values */
   92 VNET_DEFINE(int, nd6_prune)     = 1;    /* walk list every 1 seconds */
   93 VNET_DEFINE(int, nd6_delay)     = 5;    /* delay first probe time 5 second */
   94 VNET_DEFINE(int, nd6_umaxtries) = 3;    /* maximum unicast query */
   95 VNET_DEFINE(int, nd6_mmaxtries) = 3;    /* maximum multicast query */
   96 VNET_DEFINE(int, nd6_useloopback) = 1;  /* use loopback interface for
   97                                          * local traffic */
   98 VNET_DEFINE(int, nd6_gctimer)   = (60 * 60 * 24); /* 1 day: garbage
   99                                          * collection timer */
  100 
  101 /* preventing too many loops in ND option parsing */
  102 static VNET_DEFINE(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
  103 
  104 VNET_DEFINE(int, nd6_maxnudhint) = 0;   /* max # of subsequent upper
  105                                          * layer hints */
  106 static VNET_DEFINE(int, nd6_maxqueuelen) = 1; /* max pkts cached in unresolved
  107                                          * ND entries */
  108 #define V_nd6_maxndopt                  VNET(nd6_maxndopt)
  109 #define V_nd6_maxqueuelen               VNET(nd6_maxqueuelen)
  110 
  111 #ifdef ND6_DEBUG
  112 VNET_DEFINE(int, nd6_debug) = 1;
  113 #else
  114 VNET_DEFINE(int, nd6_debug) = 0;
  115 #endif
  116 
  117 static eventhandler_tag lle_event_eh, iflladdr_event_eh;
  118 
  119 VNET_DEFINE(struct nd_drhead, nd_defrouter);
  120 VNET_DEFINE(struct nd_prhead, nd_prefix);
  121 VNET_DEFINE(struct rwlock, nd6_lock);
  122 VNET_DEFINE(uint64_t, nd6_list_genid);
  123 VNET_DEFINE(struct mtx, nd6_onlink_mtx);
  124 
  125 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
  126 #define V_nd6_recalc_reachtm_interval   VNET(nd6_recalc_reachtm_interval)
  127 
  128 int     (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
  129 
  130 static int nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
  131         struct ifnet *);
  132 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
  133 static void nd6_slowtimo(void *);
  134 static int regen_tmpaddr(struct in6_ifaddr *);
  135 static void nd6_free(struct llentry **, int);
  136 static void nd6_free_redirect(const struct llentry *);
  137 static void nd6_llinfo_timer(void *);
  138 static void nd6_llinfo_settimer_locked(struct llentry *, long);
  139 static void clear_llinfo_pqueue(struct llentry *);
  140 static void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
  141 static int nd6_resolve_slow(struct ifnet *, int, struct mbuf *,
  142     const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
  143 static int nd6_need_cache(struct ifnet *);
  144  
  145 
  146 static VNET_DEFINE(struct callout, nd6_slowtimo_ch);
  147 #define V_nd6_slowtimo_ch               VNET(nd6_slowtimo_ch)
  148 
  149 VNET_DEFINE(struct callout, nd6_timer_ch);
  150 #define V_nd6_timer_ch                  VNET(nd6_timer_ch)
  151 
  152 static void
  153 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
  154 {
  155         struct rt_addrinfo rtinfo;
  156         struct sockaddr_in6 dst;
  157         struct sockaddr_dl gw;
  158         struct ifnet *ifp;
  159         int type;
  160         int fibnum;
  161 
  162         LLE_WLOCK_ASSERT(lle);
  163 
  164         if (lltable_get_af(lle->lle_tbl) != AF_INET6)
  165                 return;
  166 
  167         switch (evt) {
  168         case LLENTRY_RESOLVED:
  169                 type = RTM_ADD;
  170                 KASSERT(lle->la_flags & LLE_VALID,
  171                     ("%s: %p resolved but not valid?", __func__, lle));
  172                 break;
  173         case LLENTRY_EXPIRED:
  174                 type = RTM_DELETE;
  175                 break;
  176         default:
  177                 return;
  178         }
  179 
  180         ifp = lltable_get_ifp(lle->lle_tbl);
  181 
  182         bzero(&dst, sizeof(dst));
  183         bzero(&gw, sizeof(gw));
  184         bzero(&rtinfo, sizeof(rtinfo));
  185         lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
  186         dst.sin6_scope_id = in6_getscopezone(ifp,
  187             in6_addrscope(&dst.sin6_addr));
  188         gw.sdl_len = sizeof(struct sockaddr_dl);
  189         gw.sdl_family = AF_LINK;
  190         gw.sdl_alen = ifp->if_addrlen;
  191         gw.sdl_index = ifp->if_index;
  192         gw.sdl_type = ifp->if_type;
  193         if (evt == LLENTRY_RESOLVED)
  194                 bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
  195         rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
  196         rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
  197         rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
  198         fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib;
  199         rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
  200             type == RTM_ADD ? RTF_UP: 0), 0, fibnum);
  201 }
  202 
  203 /*
  204  * A handler for interface link layer address change event.
  205  */
  206 static void
  207 nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
  208 {
  209 
  210         lltable_update_ifaddr(LLTABLE6(ifp));
  211 }
  212 
  213 void
  214 nd6_init(void)
  215 {
  216 
  217         mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF);
  218         rw_init(&V_nd6_lock, "nd6 list");
  219 
  220         LIST_INIT(&V_nd_prefix);
  221         TAILQ_INIT(&V_nd_defrouter);
  222 
  223         /* Start timers. */
  224         callout_init(&V_nd6_slowtimo_ch, 0);
  225         callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
  226             nd6_slowtimo, curvnet);
  227 
  228         callout_init(&V_nd6_timer_ch, 0);
  229         callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
  230 
  231         nd6_dad_init();
  232         if (IS_DEFAULT_VNET(curvnet)) {
  233                 lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
  234                     NULL, EVENTHANDLER_PRI_ANY);
  235                 iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
  236                     nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
  237         }
  238 }
  239 
  240 #ifdef VIMAGE
  241 void
  242 nd6_destroy()
  243 {
  244 
  245         callout_drain(&V_nd6_slowtimo_ch);
  246         callout_drain(&V_nd6_timer_ch);
  247         if (IS_DEFAULT_VNET(curvnet)) {
  248                 EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
  249                 EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
  250         }
  251         rw_destroy(&V_nd6_lock);
  252         mtx_destroy(&V_nd6_onlink_mtx);
  253 }
  254 #endif
  255 
  256 struct nd_ifinfo *
  257 nd6_ifattach(struct ifnet *ifp)
  258 {
  259         struct nd_ifinfo *nd;
  260 
  261         nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
  262         nd->initialized = 1;
  263 
  264         nd->chlim = IPV6_DEFHLIM;
  265         nd->basereachable = REACHABLE_TIME;
  266         nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
  267         nd->retrans = RETRANS_TIMER;
  268 
  269         nd->flags = ND6_IFF_PERFORMNUD;
  270 
  271         /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
  272          * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
  273          * default regardless of the V_ip6_auto_linklocal configuration to
  274          * give a reasonable default behavior.
  275          */
  276         if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
  277             (ifp->if_flags & IFF_LOOPBACK))
  278                 nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
  279         /*
  280          * A loopback interface does not need to accept RTADV.
  281          * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
  282          * default regardless of the V_ip6_accept_rtadv configuration to
  283          * prevent the interface from accepting RA messages arrived
  284          * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
  285          */
  286         if (V_ip6_accept_rtadv &&
  287             !(ifp->if_flags & IFF_LOOPBACK) &&
  288             (ifp->if_type != IFT_BRIDGE))
  289                         nd->flags |= ND6_IFF_ACCEPT_RTADV;
  290         if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
  291                 nd->flags |= ND6_IFF_NO_RADR;
  292 
  293         /* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
  294         nd6_setmtu0(ifp, nd);
  295 
  296         return nd;
  297 }
  298 
  299 void
  300 nd6_ifdetach(struct ifnet *ifp, struct nd_ifinfo *nd)
  301 {
  302         struct ifaddr *ifa, *next;
  303 
  304         IF_ADDR_RLOCK(ifp);
  305         TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
  306                 if (ifa->ifa_addr->sa_family != AF_INET6)
  307                         continue;
  308 
  309                 /* stop DAD processing */
  310                 nd6_dad_stop(ifa);
  311         }
  312         IF_ADDR_RUNLOCK(ifp);
  313 
  314         free(nd, M_IP6NDP);
  315 }
  316 
  317 /*
  318  * Reset ND level link MTU. This function is called when the physical MTU
  319  * changes, which means we might have to adjust the ND level MTU.
  320  */
  321 void
  322 nd6_setmtu(struct ifnet *ifp)
  323 {
  324         if (ifp->if_afdata[AF_INET6] == NULL)
  325                 return;
  326 
  327         nd6_setmtu0(ifp, ND_IFINFO(ifp));
  328 }
  329 
  330 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
  331 void
  332 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
  333 {
  334         u_int32_t omaxmtu;
  335 
  336         omaxmtu = ndi->maxmtu;
  337 
  338         switch (ifp->if_type) {
  339         case IFT_ARCNET:
  340                 ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
  341                 break;
  342         case IFT_FDDI:
  343                 ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu); /* RFC2467 */
  344                 break;
  345         case IFT_ISO88025:
  346                  ndi->maxmtu = MIN(ISO88025_MAX_MTU, ifp->if_mtu);
  347                  break;
  348         default:
  349                 ndi->maxmtu = ifp->if_mtu;
  350                 break;
  351         }
  352 
  353         /*
  354          * Decreasing the interface MTU under IPV6 minimum MTU may cause
  355          * undesirable situation.  We thus notify the operator of the change
  356          * explicitly.  The check for omaxmtu is necessary to restrict the
  357          * log to the case of changing the MTU, not initializing it.
  358          */
  359         if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
  360                 log(LOG_NOTICE, "nd6_setmtu0: "
  361                     "new link MTU on %s (%lu) is too small for IPv6\n",
  362                     if_name(ifp), (unsigned long)ndi->maxmtu);
  363         }
  364 
  365         if (ndi->maxmtu > V_in6_maxmtu)
  366                 in6_setmaxmtu(); /* check all interfaces just in case */
  367 
  368 }
  369 
  370 void
  371 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
  372 {
  373 
  374         bzero(ndopts, sizeof(*ndopts));
  375         ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
  376         ndopts->nd_opts_last
  377                 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
  378 
  379         if (icmp6len == 0) {
  380                 ndopts->nd_opts_done = 1;
  381                 ndopts->nd_opts_search = NULL;
  382         }
  383 }
  384 
  385 /*
  386  * Take one ND option.
  387  */
  388 struct nd_opt_hdr *
  389 nd6_option(union nd_opts *ndopts)
  390 {
  391         struct nd_opt_hdr *nd_opt;
  392         int olen;
  393 
  394         KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
  395         KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
  396             __func__));
  397         if (ndopts->nd_opts_search == NULL)
  398                 return NULL;
  399         if (ndopts->nd_opts_done)
  400                 return NULL;
  401 
  402         nd_opt = ndopts->nd_opts_search;
  403 
  404         /* make sure nd_opt_len is inside the buffer */
  405         if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
  406                 bzero(ndopts, sizeof(*ndopts));
  407                 return NULL;
  408         }
  409 
  410         olen = nd_opt->nd_opt_len << 3;
  411         if (olen == 0) {
  412                 /*
  413                  * Message validation requires that all included
  414                  * options have a length that is greater than zero.
  415                  */
  416                 bzero(ndopts, sizeof(*ndopts));
  417                 return NULL;
  418         }
  419 
  420         ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
  421         if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
  422                 /* option overruns the end of buffer, invalid */
  423                 bzero(ndopts, sizeof(*ndopts));
  424                 return NULL;
  425         } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
  426                 /* reached the end of options chain */
  427                 ndopts->nd_opts_done = 1;
  428                 ndopts->nd_opts_search = NULL;
  429         }
  430         return nd_opt;
  431 }
  432 
  433 /*
  434  * Parse multiple ND options.
  435  * This function is much easier to use, for ND routines that do not need
  436  * multiple options of the same type.
  437  */
  438 int
  439 nd6_options(union nd_opts *ndopts)
  440 {
  441         struct nd_opt_hdr *nd_opt;
  442         int i = 0;
  443 
  444         KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
  445         KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
  446             __func__));
  447         if (ndopts->nd_opts_search == NULL)
  448                 return 0;
  449 
  450         while (1) {
  451                 nd_opt = nd6_option(ndopts);
  452                 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
  453                         /*
  454                          * Message validation requires that all included
  455                          * options have a length that is greater than zero.
  456                          */
  457                         ICMP6STAT_INC(icp6s_nd_badopt);
  458                         bzero(ndopts, sizeof(*ndopts));
  459                         return -1;
  460                 }
  461 
  462                 if (nd_opt == NULL)
  463                         goto skip1;
  464 
  465                 switch (nd_opt->nd_opt_type) {
  466                 case ND_OPT_SOURCE_LINKADDR:
  467                 case ND_OPT_TARGET_LINKADDR:
  468                 case ND_OPT_MTU:
  469                 case ND_OPT_REDIRECTED_HEADER:
  470                 case ND_OPT_NONCE:
  471                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
  472                                 nd6log((LOG_INFO,
  473                                     "duplicated ND6 option found (type=%d)\n",
  474                                     nd_opt->nd_opt_type));
  475                                 /* XXX bark? */
  476                         } else {
  477                                 ndopts->nd_opt_array[nd_opt->nd_opt_type]
  478                                         = nd_opt;
  479                         }
  480                         break;
  481                 case ND_OPT_PREFIX_INFORMATION:
  482                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
  483                                 ndopts->nd_opt_array[nd_opt->nd_opt_type]
  484                                         = nd_opt;
  485                         }
  486                         ndopts->nd_opts_pi_end =
  487                                 (struct nd_opt_prefix_info *)nd_opt;
  488                         break;
  489                 /* What about ND_OPT_ROUTE_INFO? RFC 4191 */
  490                 case ND_OPT_RDNSS:      /* RFC 6106 */
  491                 case ND_OPT_DNSSL:      /* RFC 6106 */
  492                         /*
  493                          * Silently ignore options we know and do not care about
  494                          * in the kernel.
  495                          */
  496                         break;
  497                 default:
  498                         /*
  499                          * Unknown options must be silently ignored,
  500                          * to accommodate future extension to the protocol.
  501                          */
  502                         nd6log((LOG_DEBUG,
  503                             "nd6_options: unsupported option %d - "
  504                             "option ignored\n", nd_opt->nd_opt_type));
  505                 }
  506 
  507 skip1:
  508                 i++;
  509                 if (i > V_nd6_maxndopt) {
  510                         ICMP6STAT_INC(icp6s_nd_toomanyopt);
  511                         nd6log((LOG_INFO, "too many loop in nd opt\n"));
  512                         break;
  513                 }
  514 
  515                 if (ndopts->nd_opts_done)
  516                         break;
  517         }
  518 
  519         return 0;
  520 }
  521 
  522 /*
  523  * ND6 timer routine to handle ND6 entries
  524  */
  525 static void
  526 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
  527 {
  528         int canceled;
  529 
  530         LLE_WLOCK_ASSERT(ln);
  531 
  532         if (tick < 0) {
  533                 ln->la_expire = 0;
  534                 ln->ln_ntick = 0;
  535                 canceled = callout_stop(&ln->lle_timer);
  536         } else {
  537                 ln->la_expire = time_uptime + tick / hz;
  538                 LLE_ADDREF(ln);
  539                 if (tick > INT_MAX) {
  540                         ln->ln_ntick = tick - INT_MAX;
  541                         canceled = callout_reset(&ln->lle_timer, INT_MAX,
  542                             nd6_llinfo_timer, ln);
  543                 } else {
  544                         ln->ln_ntick = 0;
  545                         canceled = callout_reset(&ln->lle_timer, tick,
  546                             nd6_llinfo_timer, ln);
  547                 }
  548         }
  549         if (canceled > 0)
  550                 LLE_REMREF(ln);
  551 }
  552 
  553 /*
  554  * Gets source address of the first packet in hold queue
  555  * and stores it in @src.
  556  * Returns pointer to @src (if hold queue is not empty) or NULL.
  557  *
  558  * Set noinline to be dtrace-friendly
  559  */
  560 static __noinline struct in6_addr *
  561 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
  562 {
  563         struct ip6_hdr hdr;
  564         struct mbuf *m;
  565 
  566         if (ln->la_hold == NULL)
  567                 return (NULL);
  568 
  569         /*
  570          * assume every packet in la_hold has the same IP header
  571          */
  572         m = ln->la_hold;
  573         if (sizeof(hdr) > m->m_len)
  574                 return (NULL);
  575 
  576         m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
  577         *src = hdr.ip6_src;
  578 
  579         return (src);
  580 }
  581 
  582 /*
  583  * Checks if we need to switch from STALE state.
  584  *
  585  * RFC 4861 requires switching from STALE to DELAY state
  586  * on first packet matching entry, waiting V_nd6_delay and
  587  * transition to PROBE state (if upper layer confirmation was
  588  * not received).
  589  *
  590  * This code performs a bit differently:
  591  * On packet hit we don't change state (but desired state
  592  * can be guessed by control plane). However, after V_nd6_delay
  593  * seconds code will transition to PROBE state (so DELAY state
  594  * is kinda skipped in most situations).
  595  *
  596  * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
  597  * we perform the following upon entering STALE state:
  598  *
  599  * 1) Arm timer to run each V_nd6_delay seconds to make sure that
  600  * if packet was transmitted at the start of given interval, we
  601  * would be able to switch to PROBE state in V_nd6_delay seconds
  602  * as user expects.
  603  *
  604  * 2) Reschedule timer until original V_nd6_gctimer expires keeping
  605  * lle in STALE state (remaining timer value stored in lle_remtime).
  606  *
  607  * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
  608  * seconds ago.
  609  *
  610  * Returns non-zero value if the entry is still STALE (storing
  611  * the next timer interval in @pdelay).
  612  *
  613  * Returns zero value if original timer expired or we need to switch to
  614  * PROBE (store that in @do_switch variable).
  615  */
  616 static int
  617 nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
  618 {
  619         int nd_delay, nd_gctimer, r_skip_req;
  620         time_t lle_hittime;
  621         long delay;
  622 
  623         *do_switch = 0;
  624         nd_gctimer = V_nd6_gctimer;
  625         nd_delay = V_nd6_delay;
  626 
  627         LLE_REQ_LOCK(lle);
  628         r_skip_req = lle->r_skip_req;
  629         lle_hittime = lle->lle_hittime;
  630         LLE_REQ_UNLOCK(lle);
  631 
  632         if (r_skip_req > 0) {
  633 
  634                 /*
  635                  * Nonzero r_skip_req value was set upon entering
  636                  * STALE state. Since value was not changed, no
  637                  * packets were passed using this lle. Ask for
  638                  * timer reschedule and keep STALE state.
  639                  */
  640                 delay = (long)(MIN(nd_gctimer, nd_delay));
  641                 delay *= hz;
  642                 if (lle->lle_remtime > delay)
  643                         lle->lle_remtime -= delay;
  644                 else {
  645                         delay = lle->lle_remtime;
  646                         lle->lle_remtime = 0;
  647                 }
  648 
  649                 if (delay == 0) {
  650 
  651                         /*
  652                          * The original ng6_gctime timeout ended,
  653                          * no more rescheduling.
  654                          */
  655                         return (0);
  656                 }
  657 
  658                 *pdelay = delay;
  659                 return (1);
  660         }
  661 
  662         /*
  663          * Packet received. Verify timestamp
  664          */
  665         delay = (long)(time_uptime - lle_hittime);
  666         if (delay < nd_delay) {
  667 
  668                 /*
  669                  * V_nd6_delay still not passed since the first
  670                  * hit in STALE state.
  671                  * Reshedule timer and return.
  672                  */
  673                 *pdelay = (long)(nd_delay - delay) * hz;
  674                 return (1);
  675         }
  676 
  677         /* Request switching to probe */
  678         *do_switch = 1;
  679         return (0);
  680 }
  681 
  682 
  683 /*
  684  * Switch @lle state to new state optionally arming timers.
  685  *
  686  * Set noinline to be dtrace-friendly
  687  */
  688 __noinline void
  689 nd6_llinfo_setstate(struct llentry *lle, int newstate)
  690 {
  691         struct ifnet *ifp;
  692         int nd_gctimer, nd_delay;
  693         long delay, remtime;
  694 
  695         delay = 0;
  696         remtime = 0;
  697 
  698         switch (newstate) {
  699         case ND6_LLINFO_INCOMPLETE:
  700                 ifp = lle->lle_tbl->llt_ifp;
  701                 delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000;
  702                 break;
  703         case ND6_LLINFO_REACHABLE:
  704                 if (!ND6_LLINFO_PERMANENT(lle)) {
  705                         ifp = lle->lle_tbl->llt_ifp;
  706                         delay = (long)ND_IFINFO(ifp)->reachable * hz;
  707                 }
  708                 break;
  709         case ND6_LLINFO_STALE:
  710 
  711                 /*
  712                  * Notify fast path that we want to know if any packet
  713                  * is transmitted by setting r_skip_req.
  714                  */
  715                 LLE_REQ_LOCK(lle);
  716                 lle->r_skip_req = 1;
  717                 LLE_REQ_UNLOCK(lle);
  718                 nd_delay = V_nd6_delay;
  719                 nd_gctimer = V_nd6_gctimer;
  720 
  721                 delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
  722                 remtime = (long)nd_gctimer * hz - delay;
  723                 break;
  724         case ND6_LLINFO_DELAY:
  725                 lle->la_asked = 0;
  726                 delay = (long)V_nd6_delay * hz;
  727                 break;
  728         }
  729 
  730         if (delay > 0)
  731                 nd6_llinfo_settimer_locked(lle, delay);
  732 
  733         lle->lle_remtime = remtime;
  734         lle->ln_state = newstate;
  735 }
  736 
  737 /*
  738  * Timer-dependent part of nd state machine.
  739  *
  740  * Set noinline to be dtrace-friendly
  741  */
  742 static __noinline void
  743 nd6_llinfo_timer(void *arg)
  744 {
  745         struct llentry *ln;
  746         struct in6_addr *dst, *pdst, *psrc, src;
  747         struct ifnet *ifp;
  748         struct nd_ifinfo *ndi;
  749         int do_switch, send_ns;
  750         long delay;
  751 
  752         KASSERT(arg != NULL, ("%s: arg NULL", __func__));
  753         ln = (struct llentry *)arg;
  754         ifp = lltable_get_ifp(ln->lle_tbl);
  755         CURVNET_SET(ifp->if_vnet);
  756 
  757         ND6_RLOCK();
  758         LLE_WLOCK(ln);
  759         if (callout_pending(&ln->lle_timer)) {
  760                 /*
  761                  * Here we are a bit odd here in the treatment of 
  762                  * active/pending. If the pending bit is set, it got
  763                  * rescheduled before I ran. The active
  764                  * bit we ignore, since if it was stopped
  765                  * in ll_tablefree() and was currently running
  766                  * it would have return 0 so the code would
  767                  * not have deleted it since the callout could
  768                  * not be stopped so we want to go through
  769                  * with the delete here now. If the callout
  770                  * was restarted, the pending bit will be back on and
  771                  * we just want to bail since the callout_reset would
  772                  * return 1 and our reference would have been removed
  773                  * by nd6_llinfo_settimer_locked above since canceled
  774                  * would have been 1.
  775                  */
  776                 LLE_WUNLOCK(ln);
  777                 ND6_RUNLOCK();
  778                 CURVNET_RESTORE();
  779                 return;
  780         }
  781         ndi = ND_IFINFO(ifp);
  782         send_ns = 0;
  783         dst = &ln->r_l3addr.addr6;
  784         pdst = dst;
  785 
  786         if (ln->ln_ntick > 0) {
  787                 if (ln->ln_ntick > INT_MAX) {
  788                         ln->ln_ntick -= INT_MAX;
  789                         nd6_llinfo_settimer_locked(ln, INT_MAX);
  790                 } else {
  791                         ln->ln_ntick = 0;
  792                         nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
  793                 }
  794                 goto done;
  795         }
  796 
  797         if (ln->la_flags & LLE_STATIC) {
  798                 goto done;
  799         }
  800 
  801         if (ln->la_flags & LLE_DELETED) {
  802                 nd6_free(&ln, 0);
  803                 goto done;
  804         }
  805 
  806         switch (ln->ln_state) {
  807         case ND6_LLINFO_INCOMPLETE:
  808                 if (ln->la_asked < V_nd6_mmaxtries) {
  809                         ln->la_asked++;
  810                         send_ns = 1;
  811                         /* Send NS to multicast address */
  812                         pdst = NULL;
  813                 } else {
  814                         struct mbuf *m = ln->la_hold;
  815                         if (m) {
  816                                 struct mbuf *m0;
  817 
  818                                 /*
  819                                  * assuming every packet in la_hold has the
  820                                  * same IP header.  Send error after unlock.
  821                                  */
  822                                 m0 = m->m_nextpkt;
  823                                 m->m_nextpkt = NULL;
  824                                 ln->la_hold = m0;
  825                                 clear_llinfo_pqueue(ln);
  826                         }
  827                         nd6_free(&ln, 0);
  828                         if (m != NULL)
  829                                 icmp6_error2(m, ICMP6_DST_UNREACH,
  830                                     ICMP6_DST_UNREACH_ADDR, 0, ifp);
  831                 }
  832                 break;
  833         case ND6_LLINFO_REACHABLE:
  834                 if (!ND6_LLINFO_PERMANENT(ln))
  835                         nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
  836                 break;
  837 
  838         case ND6_LLINFO_STALE:
  839                 if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
  840 
  841                         /*
  842                          * No packet has used this entry and GC timeout
  843                          * has not been passed. Reshedule timer and
  844                          * return.
  845                          */
  846                         nd6_llinfo_settimer_locked(ln, delay);
  847                         break;
  848                 }
  849 
  850                 if (do_switch == 0) {
  851 
  852                         /*
  853                          * GC timer has ended and entry hasn't been used.
  854                          * Run Garbage collector (RFC 4861, 5.3)
  855                          */
  856                         if (!ND6_LLINFO_PERMANENT(ln))
  857                                 nd6_free(&ln, 1);
  858                         break;
  859                 }
  860 
  861                 /* Entry has been used AND delay timer has ended. */
  862 
  863                 /* FALLTHROUGH */
  864 
  865         case ND6_LLINFO_DELAY:
  866                 if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
  867                         /* We need NUD */
  868                         ln->la_asked = 1;
  869                         nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
  870                         send_ns = 1;
  871                 } else
  872                         nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
  873                 break;
  874         case ND6_LLINFO_PROBE:
  875                 if (ln->la_asked < V_nd6_umaxtries) {
  876                         ln->la_asked++;
  877                         send_ns = 1;
  878                 } else {
  879                         nd6_free(&ln, 0);
  880                 }
  881                 break;
  882         default:
  883                 panic("%s: paths in a dark night can be confusing: %d",
  884                     __func__, ln->ln_state);
  885         }
  886 done:
  887         if (ln != NULL)
  888                 ND6_RUNLOCK();
  889         if (send_ns != 0) {
  890                 nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
  891                 psrc = nd6_llinfo_get_holdsrc(ln, &src);
  892                 LLE_FREE_LOCKED(ln);
  893                 ln = NULL;
  894                 nd6_ns_output(ifp, psrc, pdst, dst, NULL);
  895         }
  896 
  897         if (ln != NULL)
  898                 LLE_FREE_LOCKED(ln);
  899         CURVNET_RESTORE();
  900 }
  901 
  902 
  903 /*
  904  * ND6 timer routine to expire default route list and prefix list
  905  */
  906 void
  907 nd6_timer(void *arg)
  908 {
  909         CURVNET_SET((struct vnet *) arg);
  910         struct nd_drhead drq;
  911         struct nd_prhead prl;
  912         struct nd_defrouter *dr, *ndr;
  913         struct nd_prefix *pr, *npr;
  914         struct in6_ifaddr *ia6, *nia6;
  915         uint64_t genid;
  916 
  917         TAILQ_INIT(&drq);
  918         LIST_INIT(&prl);
  919 
  920         ND6_WLOCK();
  921         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr)
  922                 if (dr->expire && dr->expire < time_uptime)
  923                         defrouter_unlink(dr, &drq);
  924         ND6_WUNLOCK();
  925 
  926         while ((dr = TAILQ_FIRST(&drq)) != NULL) {
  927                 TAILQ_REMOVE(&drq, dr, dr_entry);
  928                 defrouter_del(dr);
  929         }
  930 
  931         /*
  932          * expire interface addresses.
  933          * in the past the loop was inside prefix expiry processing.
  934          * However, from a stricter speci-confrmance standpoint, we should
  935          * rather separate address lifetimes and prefix lifetimes.
  936          *
  937          * XXXRW: in6_ifaddrhead locking.
  938          */
  939   addrloop:
  940         TAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
  941                 /* check address lifetime */
  942                 if (IFA6_IS_INVALID(ia6)) {
  943                         int regen = 0;
  944 
  945                         /*
  946                          * If the expiring address is temporary, try
  947                          * regenerating a new one.  This would be useful when
  948                          * we suspended a laptop PC, then turned it on after a
  949                          * period that could invalidate all temporary
  950                          * addresses.  Although we may have to restart the
  951                          * loop (see below), it must be after purging the
  952                          * address.  Otherwise, we'd see an infinite loop of
  953                          * regeneration.
  954                          */
  955                         if (V_ip6_use_tempaddr &&
  956                             (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
  957                                 if (regen_tmpaddr(ia6) == 0)
  958                                         regen = 1;
  959                         }
  960 
  961                         in6_purgeaddr(&ia6->ia_ifa);
  962 
  963                         if (regen)
  964                                 goto addrloop; /* XXX: see below */
  965                 } else if (IFA6_IS_DEPRECATED(ia6)) {
  966                         int oldflags = ia6->ia6_flags;
  967 
  968                         ia6->ia6_flags |= IN6_IFF_DEPRECATED;
  969 
  970                         /*
  971                          * If a temporary address has just become deprecated,
  972                          * regenerate a new one if possible.
  973                          */
  974                         if (V_ip6_use_tempaddr &&
  975                             (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
  976                             (oldflags & IN6_IFF_DEPRECATED) == 0) {
  977 
  978                                 if (regen_tmpaddr(ia6) == 0) {
  979                                         /*
  980                                          * A new temporary address is
  981                                          * generated.
  982                                          * XXX: this means the address chain
  983                                          * has changed while we are still in
  984                                          * the loop.  Although the change
  985                                          * would not cause disaster (because
  986                                          * it's not a deletion, but an
  987                                          * addition,) we'd rather restart the
  988                                          * loop just for safety.  Or does this
  989                                          * significantly reduce performance??
  990                                          */
  991                                         goto addrloop;
  992                                 }
  993                         }
  994                 } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
  995                         /*
  996                          * Schedule DAD for a tentative address.  This happens
  997                          * if the interface was down or not running
  998                          * when the address was configured.
  999                          */
 1000                         int delay;
 1001 
 1002                         delay = arc4random() %
 1003                             (MAX_RTR_SOLICITATION_DELAY * hz);
 1004                         nd6_dad_start((struct ifaddr *)ia6, delay);
 1005                 } else {
 1006                         /*
 1007                          * Check status of the interface.  If it is down,
 1008                          * mark the address as tentative for future DAD.
 1009                          */
 1010                         if ((ia6->ia_ifp->if_flags & IFF_UP) == 0 ||
 1011                             (ia6->ia_ifp->if_drv_flags & IFF_DRV_RUNNING)
 1012                                 == 0 ||
 1013                             (ND_IFINFO(ia6->ia_ifp)->flags &
 1014                                 ND6_IFF_IFDISABLED) != 0) {
 1015                                 ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
 1016                                 ia6->ia6_flags |= IN6_IFF_TENTATIVE;
 1017                         }
 1018                         /*
 1019                          * A new RA might have made a deprecated address
 1020                          * preferred.
 1021                          */
 1022                         ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
 1023                 }
 1024         }
 1025 
 1026         ND6_WLOCK();
 1027 restart:
 1028         LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
 1029                 /*
 1030                  * Expire prefixes. Since the pltime is only used for
 1031                  * autoconfigured addresses, pltime processing for prefixes is
 1032                  * not necessary.
 1033                  *
 1034                  * Only unlink after all derived addresses have expired. This
 1035                  * may not occur until two hours after the prefix has expired
 1036                  * per RFC 4862. If the prefix expires before its derived
 1037                  * addresses, mark it off-link. This will be done automatically
 1038                  * after unlinking if no address references remain.
 1039                  */
 1040                 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME ||
 1041                     time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime)
 1042                         continue;
 1043 
 1044                 if (pr->ndpr_addrcnt == 0) {
 1045                         nd6_prefix_unlink(pr, &prl);
 1046                         continue;
 1047                 }
 1048                 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 1049                         genid = V_nd6_list_genid;
 1050                         nd6_prefix_ref(pr);
 1051                         ND6_WUNLOCK();
 1052                         ND6_ONLINK_LOCK();
 1053                         (void)nd6_prefix_offlink(pr);
 1054                         ND6_ONLINK_UNLOCK();
 1055                         ND6_WLOCK();
 1056                         nd6_prefix_rele(pr);
 1057                         if (genid != V_nd6_list_genid)
 1058                                 goto restart;
 1059                 }
 1060         }
 1061         ND6_WUNLOCK();
 1062 
 1063         while ((pr = LIST_FIRST(&prl)) != NULL) {
 1064                 LIST_REMOVE(pr, ndpr_entry);
 1065                 nd6_prefix_del(pr);
 1066         }
 1067 
 1068         callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
 1069             nd6_timer, curvnet);
 1070 
 1071         CURVNET_RESTORE();
 1072 }
 1073 
 1074 /*
 1075  * ia6 - deprecated/invalidated temporary address
 1076  */
 1077 static int
 1078 regen_tmpaddr(struct in6_ifaddr *ia6)
 1079 {
 1080         struct ifaddr *ifa;
 1081         struct ifnet *ifp;
 1082         struct in6_ifaddr *public_ifa6 = NULL;
 1083 
 1084         ifp = ia6->ia_ifa.ifa_ifp;
 1085         IF_ADDR_RLOCK(ifp);
 1086         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1087                 struct in6_ifaddr *it6;
 1088 
 1089                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1090                         continue;
 1091 
 1092                 it6 = (struct in6_ifaddr *)ifa;
 1093 
 1094                 /* ignore no autoconf addresses. */
 1095                 if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1096                         continue;
 1097 
 1098                 /* ignore autoconf addresses with different prefixes. */
 1099                 if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
 1100                         continue;
 1101 
 1102                 /*
 1103                  * Now we are looking at an autoconf address with the same
 1104                  * prefix as ours.  If the address is temporary and is still
 1105                  * preferred, do not create another one.  It would be rare, but
 1106                  * could happen, for example, when we resume a laptop PC after
 1107                  * a long period.
 1108                  */
 1109                 if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
 1110                     !IFA6_IS_DEPRECATED(it6)) {
 1111                         public_ifa6 = NULL;
 1112                         break;
 1113                 }
 1114 
 1115                 /*
 1116                  * This is a public autoconf address that has the same prefix
 1117                  * as ours.  If it is preferred, keep it.  We can't break the
 1118                  * loop here, because there may be a still-preferred temporary
 1119                  * address with the prefix.
 1120                  */
 1121                 if (!IFA6_IS_DEPRECATED(it6))
 1122                         public_ifa6 = it6;
 1123         }
 1124         if (public_ifa6 != NULL)
 1125                 ifa_ref(&public_ifa6->ia_ifa);
 1126         IF_ADDR_RUNLOCK(ifp);
 1127 
 1128         if (public_ifa6 != NULL) {
 1129                 int e;
 1130 
 1131                 if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
 1132                         ifa_free(&public_ifa6->ia_ifa);
 1133                         log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
 1134                             " tmp addr,errno=%d\n", e);
 1135                         return (-1);
 1136                 }
 1137                 ifa_free(&public_ifa6->ia_ifa);
 1138                 return (0);
 1139         }
 1140 
 1141         return (-1);
 1142 }
 1143 
 1144 /*
 1145  * Remove prefix and default router list entries corresponding to ifp. Neighbor
 1146  * cache entries are freed in in6_domifdetach().
 1147  */
 1148 void
 1149 nd6_purge(struct ifnet *ifp)
 1150 {
 1151         struct nd_drhead drq;
 1152         struct nd_prhead prl;
 1153         struct nd_defrouter *dr, *ndr;
 1154         struct nd_prefix *pr, *npr;
 1155 
 1156         TAILQ_INIT(&drq);
 1157         LIST_INIT(&prl);
 1158 
 1159         /*
 1160          * Nuke default router list entries toward ifp.
 1161          * We defer removal of default router list entries that is installed
 1162          * in the routing table, in order to keep additional side effects as
 1163          * small as possible.
 1164          */
 1165         ND6_WLOCK();
 1166         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
 1167                 if (dr->installed)
 1168                         continue;
 1169                 if (dr->ifp == ifp)
 1170                         defrouter_unlink(dr, &drq);
 1171         }
 1172         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
 1173                 if (!dr->installed)
 1174                         continue;
 1175                 if (dr->ifp == ifp)
 1176                         defrouter_unlink(dr, &drq);
 1177         }
 1178 
 1179         /*
 1180          * Remove prefixes on ifp. We should have already removed addresses on
 1181          * this interface, so no addresses should be referencing these prefixes.
 1182          */
 1183         LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
 1184                 if (pr->ndpr_ifp == ifp)
 1185                         nd6_prefix_unlink(pr, &prl);
 1186         }
 1187         ND6_WUNLOCK();
 1188 
 1189         /* Delete the unlinked router and prefix objects. */
 1190         while ((dr = TAILQ_FIRST(&drq)) != NULL) {
 1191                 TAILQ_REMOVE(&drq, dr, dr_entry);
 1192                 defrouter_del(dr);
 1193         }
 1194         while ((pr = LIST_FIRST(&prl)) != NULL) {
 1195                 LIST_REMOVE(pr, ndpr_entry);
 1196                 nd6_prefix_del(pr);
 1197         }
 1198 
 1199         /* cancel default outgoing interface setting */
 1200         if (V_nd6_defifindex == ifp->if_index)
 1201                 nd6_setdefaultiface(0);
 1202 
 1203         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 1204                 /* Refresh default router list. */
 1205                 defrouter_select_fib(ifp->if_fib);
 1206         }
 1207 }
 1208 
 1209 /* 
 1210  * the caller acquires and releases the lock on the lltbls
 1211  * Returns the llentry locked
 1212  */
 1213 struct llentry *
 1214 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
 1215 {
 1216         struct sockaddr_in6 sin6;
 1217         struct llentry *ln;
 1218         
 1219         bzero(&sin6, sizeof(sin6));
 1220         sin6.sin6_len = sizeof(struct sockaddr_in6);
 1221         sin6.sin6_family = AF_INET6;
 1222         sin6.sin6_addr = *addr6;
 1223 
 1224         IF_AFDATA_LOCK_ASSERT(ifp);
 1225 
 1226         ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
 1227 
 1228         return (ln);
 1229 }
 1230 
 1231 struct llentry *
 1232 nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
 1233 {
 1234         struct sockaddr_in6 sin6;
 1235         struct llentry *ln;
 1236 
 1237         bzero(&sin6, sizeof(sin6));
 1238         sin6.sin6_len = sizeof(struct sockaddr_in6);
 1239         sin6.sin6_family = AF_INET6;
 1240         sin6.sin6_addr = *addr6;
 1241 
 1242         ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
 1243         if (ln != NULL)
 1244                 ln->ln_state = ND6_LLINFO_NOSTATE;
 1245 
 1246         return (ln);
 1247 }
 1248 
 1249 /*
 1250  * Test whether a given IPv6 address is a neighbor or not, ignoring
 1251  * the actual neighbor cache.  The neighbor cache is ignored in order
 1252  * to not reenter the routing code from within itself.
 1253  */
 1254 static int
 1255 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
 1256 {
 1257         struct nd_prefix *pr;
 1258         struct ifaddr *ifa;
 1259         struct rt_addrinfo info;
 1260         struct sockaddr_in6 rt_key;
 1261         const struct sockaddr *dst6;
 1262         uint64_t genid;
 1263         int error, fibnum;
 1264 
 1265         /*
 1266          * A link-local address is always a neighbor.
 1267          * XXX: a link does not necessarily specify a single interface.
 1268          */
 1269         if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
 1270                 struct sockaddr_in6 sin6_copy;
 1271                 u_int32_t zone;
 1272 
 1273                 /*
 1274                  * We need sin6_copy since sa6_recoverscope() may modify the
 1275                  * content (XXX).
 1276                  */
 1277                 sin6_copy = *addr;
 1278                 if (sa6_recoverscope(&sin6_copy))
 1279                         return (0); /* XXX: should be impossible */
 1280                 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
 1281                         return (0);
 1282                 if (sin6_copy.sin6_scope_id == zone)
 1283                         return (1);
 1284                 else
 1285                         return (0);
 1286         }
 1287 
 1288         bzero(&rt_key, sizeof(rt_key));
 1289         bzero(&info, sizeof(info));
 1290         info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key;
 1291 
 1292         /*
 1293          * If the address matches one of our addresses,
 1294          * it should be a neighbor.
 1295          * If the address matches one of our on-link prefixes, it should be a
 1296          * neighbor.
 1297          */
 1298         ND6_RLOCK();
 1299 restart:
 1300         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 1301                 if (pr->ndpr_ifp != ifp)
 1302                         continue;
 1303 
 1304                 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
 1305                         dst6 = (const struct sockaddr *)&pr->ndpr_prefix;
 1306 
 1307                         /*
 1308                          * We only need to check all FIBs if add_addr_allfibs
 1309                          * is unset. If set, checking any FIB will suffice.
 1310                          */
 1311                         fibnum = V_rt_add_addr_allfibs ? rt_numfibs - 1 : 0;
 1312                         for (; fibnum < rt_numfibs; fibnum++) {
 1313                                 genid = V_nd6_list_genid;
 1314                                 ND6_RUNLOCK();
 1315 
 1316                                 /*
 1317                                  * Restore length field before
 1318                                  * retrying lookup
 1319                                  */
 1320                                 rt_key.sin6_len = sizeof(rt_key);
 1321                                 error = rib_lookup_info(fibnum, dst6, 0, 0,
 1322                                                         &info);
 1323 
 1324                                 ND6_RLOCK();
 1325                                 if (genid != V_nd6_list_genid)
 1326                                         goto restart;
 1327                                 if (error == 0)
 1328                                         break;
 1329                         }
 1330                         if (error != 0)
 1331                                 continue;
 1332 
 1333                         /*
 1334                          * This is the case where multiple interfaces
 1335                          * have the same prefix, but only one is installed 
 1336                          * into the routing table and that prefix entry
 1337                          * is not the one being examined here. In the case
 1338                          * where RADIX_MPATH is enabled, multiple route
 1339                          * entries (of the same rt_key value) will be 
 1340                          * installed because the interface addresses all
 1341                          * differ.
 1342                          */
 1343                         if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
 1344                             &rt_key.sin6_addr))
 1345                                 continue;
 1346                 }
 1347 
 1348                 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
 1349                     &addr->sin6_addr, &pr->ndpr_mask)) {
 1350                         ND6_RUNLOCK();
 1351                         return (1);
 1352                 }
 1353         }
 1354         ND6_RUNLOCK();
 1355 
 1356         /*
 1357          * If the address is assigned on the node of the other side of
 1358          * a p2p interface, the address should be a neighbor.
 1359          */
 1360         if (ifp->if_flags & IFF_POINTOPOINT) {
 1361                 IF_ADDR_RLOCK(ifp);
 1362                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1363                         if (ifa->ifa_addr->sa_family != addr->sin6_family)
 1364                                 continue;
 1365                         if (ifa->ifa_dstaddr != NULL &&
 1366                             sa_equal(addr, ifa->ifa_dstaddr)) {
 1367                                 IF_ADDR_RUNLOCK(ifp);
 1368                                 return 1;
 1369                         }
 1370                 }
 1371                 IF_ADDR_RUNLOCK(ifp);
 1372         }
 1373 
 1374         /*
 1375          * If the default router list is empty, all addresses are regarded
 1376          * as on-link, and thus, as a neighbor.
 1377          */
 1378         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
 1379             TAILQ_EMPTY(&V_nd_defrouter) &&
 1380             V_nd6_defifindex == ifp->if_index) {
 1381                 return (1);
 1382         }
 1383 
 1384         return (0);
 1385 }
 1386 
 1387 
 1388 /*
 1389  * Detect if a given IPv6 address identifies a neighbor on a given link.
 1390  * XXX: should take care of the destination of a p2p link?
 1391  */
 1392 int
 1393 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
 1394 {
 1395         struct llentry *lle;
 1396         int rc = 0;
 1397 
 1398         IF_AFDATA_UNLOCK_ASSERT(ifp);
 1399         if (nd6_is_new_addr_neighbor(addr, ifp))
 1400                 return (1);
 1401 
 1402         /*
 1403          * Even if the address matches none of our addresses, it might be
 1404          * in the neighbor cache.
 1405          */
 1406         IF_AFDATA_RLOCK(ifp);
 1407         if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
 1408                 LLE_RUNLOCK(lle);
 1409                 rc = 1;
 1410         }
 1411         IF_AFDATA_RUNLOCK(ifp);
 1412         return (rc);
 1413 }
 1414 
 1415 /*
 1416  * Free an nd6 llinfo entry.
 1417  * Since the function would cause significant changes in the kernel, DO NOT
 1418  * make it global, unless you have a strong reason for the change, and are sure
 1419  * that the change is safe.
 1420  *
 1421  * Set noinline to be dtrace-friendly
 1422  */
 1423 static __noinline void
 1424 nd6_free(struct llentry **lnp, int gc)
 1425 {
 1426         struct ifnet *ifp;
 1427         struct llentry *ln;
 1428         struct nd_defrouter *dr;
 1429 
 1430         ln = *lnp;
 1431         *lnp = NULL;
 1432 
 1433         LLE_WLOCK_ASSERT(ln);
 1434         ND6_RLOCK_ASSERT();
 1435 
 1436         ifp = lltable_get_ifp(ln->lle_tbl);
 1437         if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0)
 1438                 dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
 1439         else
 1440                 dr = NULL;
 1441         ND6_RUNLOCK();
 1442 
 1443         if ((ln->la_flags & LLE_DELETED) == 0)
 1444                 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
 1445 
 1446         /*
 1447          * we used to have pfctlinput(PRC_HOSTDEAD) here.
 1448          * even though it is not harmful, it was not really necessary.
 1449          */
 1450 
 1451         /* cancel timer */
 1452         nd6_llinfo_settimer_locked(ln, -1);
 1453 
 1454         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 1455                 if (dr != NULL && dr->expire &&
 1456                     ln->ln_state == ND6_LLINFO_STALE && gc) {
 1457                         /*
 1458                          * If the reason for the deletion is just garbage
 1459                          * collection, and the neighbor is an active default
 1460                          * router, do not delete it.  Instead, reset the GC
 1461                          * timer using the router's lifetime.
 1462                          * Simply deleting the entry would affect default
 1463                          * router selection, which is not necessarily a good
 1464                          * thing, especially when we're using router preference
 1465                          * values.
 1466                          * XXX: the check for ln_state would be redundant,
 1467                          *      but we intentionally keep it just in case.
 1468                          */
 1469                         if (dr->expire > time_uptime)
 1470                                 nd6_llinfo_settimer_locked(ln,
 1471                                     (dr->expire - time_uptime) * hz);
 1472                         else
 1473                                 nd6_llinfo_settimer_locked(ln,
 1474                                     (long)V_nd6_gctimer * hz);
 1475 
 1476                         LLE_REMREF(ln);
 1477                         LLE_WUNLOCK(ln);
 1478                         defrouter_rele(dr);
 1479                         return;
 1480                 }
 1481 
 1482                 if (dr) {
 1483                         /*
 1484                          * Unreachablity of a router might affect the default
 1485                          * router selection and on-link detection of advertised
 1486                          * prefixes.
 1487                          */
 1488 
 1489                         /*
 1490                          * Temporarily fake the state to choose a new default
 1491                          * router and to perform on-link determination of
 1492                          * prefixes correctly.
 1493                          * Below the state will be set correctly,
 1494                          * or the entry itself will be deleted.
 1495                          */
 1496                         ln->ln_state = ND6_LLINFO_INCOMPLETE;
 1497                 }
 1498 
 1499                 if (ln->ln_router || dr) {
 1500 
 1501                         /*
 1502                          * We need to unlock to avoid a LOR with rt6_flush() with the
 1503                          * rnh and for the calls to pfxlist_onlink_check() and
 1504                          * defrouter_select_fib() in the block further down for calls
 1505                          * into nd6_lookup().  We still hold a ref.
 1506                          */
 1507                         LLE_WUNLOCK(ln);
 1508 
 1509                         /*
 1510                          * rt6_flush must be called whether or not the neighbor
 1511                          * is in the Default Router List.
 1512                          * See a corresponding comment in nd6_na_input().
 1513                          */
 1514                         rt6_flush(&ln->r_l3addr.addr6, ifp);
 1515                 }
 1516 
 1517                 if (dr) {
 1518                         /*
 1519                          * Since defrouter_select_fib() does not affect the
 1520                          * on-link determination and MIP6 needs the check
 1521                          * before the default router selection, we perform
 1522                          * the check now.
 1523                          */
 1524                         pfxlist_onlink_check();
 1525 
 1526                         /*
 1527                          * Refresh default router list.
 1528                          */
 1529                         defrouter_select_fib(dr->ifp->if_fib);
 1530                 }
 1531 
 1532                 /*
 1533                  * If this entry was added by an on-link redirect, remove the
 1534                  * corresponding host route.
 1535                  */
 1536                 if (ln->la_flags & LLE_REDIRECT)
 1537                         nd6_free_redirect(ln);
 1538 
 1539                 if (ln->ln_router || dr)
 1540                         LLE_WLOCK(ln);
 1541         }
 1542 
 1543         /*
 1544          * Save to unlock. We still hold an extra reference and will not
 1545          * free(9) in llentry_free() if someone else holds one as well.
 1546          */
 1547         LLE_WUNLOCK(ln);
 1548         IF_AFDATA_LOCK(ifp);
 1549         LLE_WLOCK(ln);
 1550         /* Guard against race with other llentry_free(). */
 1551         if (ln->la_flags & LLE_LINKED) {
 1552                 /* Remove callout reference */
 1553                 LLE_REMREF(ln);
 1554                 lltable_unlink_entry(ln->lle_tbl, ln);
 1555         }
 1556         IF_AFDATA_UNLOCK(ifp);
 1557 
 1558         llentry_free(ln);
 1559         if (dr != NULL)
 1560                 defrouter_rele(dr);
 1561 }
 1562 
 1563 static int
 1564 nd6_isdynrte(const struct rtentry *rt, void *xap)
 1565 {
 1566 
 1567         if (rt->rt_flags == (RTF_UP | RTF_HOST | RTF_DYNAMIC))
 1568                 return (1);
 1569 
 1570         return (0);
 1571 }
 1572 /*
 1573  * Remove the rtentry for the given llentry,
 1574  * both of which were installed by a redirect.
 1575  */
 1576 static void
 1577 nd6_free_redirect(const struct llentry *ln)
 1578 {
 1579         int fibnum;
 1580         struct sockaddr_in6 sin6;
 1581         struct rt_addrinfo info;
 1582 
 1583         lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
 1584         memset(&info, 0, sizeof(info));
 1585         info.rti_info[RTAX_DST] = (struct sockaddr *)&sin6;
 1586         info.rti_filter = nd6_isdynrte;
 1587 
 1588         for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
 1589                 rtrequest1_fib(RTM_DELETE, &info, NULL, fibnum);
 1590 }
 1591 
 1592 /*
 1593  * Rejuvenate this function for routing operations related
 1594  * processing.
 1595  */
 1596 void
 1597 nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
 1598 {
 1599         struct sockaddr_in6 *gateway;
 1600         struct nd_defrouter *dr;
 1601         struct ifnet *ifp;
 1602 
 1603         gateway = (struct sockaddr_in6 *)rt->rt_gateway;
 1604         ifp = rt->rt_ifp;
 1605 
 1606         switch (req) {
 1607         case RTM_ADD:
 1608                 break;
 1609 
 1610         case RTM_DELETE:
 1611                 if (!ifp)
 1612                         return;
 1613                 /*
 1614                  * Only indirect routes are interesting.
 1615                  */
 1616                 if ((rt->rt_flags & RTF_GATEWAY) == 0)
 1617                         return;
 1618                 /*
 1619                  * check for default route
 1620                  */
 1621                 if (IN6_ARE_ADDR_EQUAL(&in6addr_any,
 1622                     &SIN6(rt_key(rt))->sin6_addr)) {
 1623                         dr = defrouter_lookup(&gateway->sin6_addr, ifp);
 1624                         if (dr != NULL) {
 1625                                 dr->installed = 0;
 1626                                 defrouter_rele(dr);
 1627                         }
 1628                 }
 1629                 break;
 1630         }
 1631 }
 1632 
 1633 
 1634 int
 1635 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
 1636 {
 1637         struct in6_ndireq *ndi = (struct in6_ndireq *)data;
 1638         struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
 1639         struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
 1640         int error = 0;
 1641 
 1642         if (ifp->if_afdata[AF_INET6] == NULL)
 1643                 return (EPFNOSUPPORT);
 1644         switch (cmd) {
 1645         case OSIOCGIFINFO_IN6:
 1646 #define ND      ndi->ndi
 1647                 /* XXX: old ndp(8) assumes a positive value for linkmtu. */
 1648                 bzero(&ND, sizeof(ND));
 1649                 ND.linkmtu = IN6_LINKMTU(ifp);
 1650                 ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
 1651                 ND.basereachable = ND_IFINFO(ifp)->basereachable;
 1652                 ND.reachable = ND_IFINFO(ifp)->reachable;
 1653                 ND.retrans = ND_IFINFO(ifp)->retrans;
 1654                 ND.flags = ND_IFINFO(ifp)->flags;
 1655                 ND.recalctm = ND_IFINFO(ifp)->recalctm;
 1656                 ND.chlim = ND_IFINFO(ifp)->chlim;
 1657                 break;
 1658         case SIOCGIFINFO_IN6:
 1659                 ND = *ND_IFINFO(ifp);
 1660                 break;
 1661         case SIOCSIFINFO_IN6:
 1662                 /*
 1663                  * used to change host variables from userland.
 1664                  * intended for a use on router to reflect RA configurations.
 1665                  */
 1666                 /* 0 means 'unspecified' */
 1667                 if (ND.linkmtu != 0) {
 1668                         if (ND.linkmtu < IPV6_MMTU ||
 1669                             ND.linkmtu > IN6_LINKMTU(ifp)) {
 1670                                 error = EINVAL;
 1671                                 break;
 1672                         }
 1673                         ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
 1674                 }
 1675 
 1676                 if (ND.basereachable != 0) {
 1677                         int obasereachable = ND_IFINFO(ifp)->basereachable;
 1678 
 1679                         ND_IFINFO(ifp)->basereachable = ND.basereachable;
 1680                         if (ND.basereachable != obasereachable)
 1681                                 ND_IFINFO(ifp)->reachable =
 1682                                     ND_COMPUTE_RTIME(ND.basereachable);
 1683                 }
 1684                 if (ND.retrans != 0)
 1685                         ND_IFINFO(ifp)->retrans = ND.retrans;
 1686                 if (ND.chlim != 0)
 1687                         ND_IFINFO(ifp)->chlim = ND.chlim;
 1688                 /* FALLTHROUGH */
 1689         case SIOCSIFINFO_FLAGS:
 1690         {
 1691                 struct ifaddr *ifa;
 1692                 struct in6_ifaddr *ia;
 1693 
 1694                 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
 1695                     !(ND.flags & ND6_IFF_IFDISABLED)) {
 1696                         /* ifdisabled 1->0 transision */
 1697 
 1698                         /*
 1699                          * If the interface is marked as ND6_IFF_IFDISABLED and
 1700                          * has an link-local address with IN6_IFF_DUPLICATED,
 1701                          * do not clear ND6_IFF_IFDISABLED.
 1702                          * See RFC 4862, Section 5.4.5.
 1703                          */
 1704                         IF_ADDR_RLOCK(ifp);
 1705                         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1706                                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1707                                         continue;
 1708                                 ia = (struct in6_ifaddr *)ifa;
 1709                                 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
 1710                                     IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
 1711                                         break;
 1712                         }
 1713                         IF_ADDR_RUNLOCK(ifp);
 1714 
 1715                         if (ifa != NULL) {
 1716                                 /* LLA is duplicated. */
 1717                                 ND.flags |= ND6_IFF_IFDISABLED;
 1718                                 log(LOG_ERR, "Cannot enable an interface"
 1719                                     " with a link-local address marked"
 1720                                     " duplicate.\n");
 1721                         } else {
 1722                                 ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
 1723                                 if (ifp->if_flags & IFF_UP)
 1724                                         in6_if_up(ifp);
 1725                         }
 1726                 } else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
 1727                             (ND.flags & ND6_IFF_IFDISABLED)) {
 1728                         /* ifdisabled 0->1 transision */
 1729                         /* Mark all IPv6 address as tentative. */
 1730 
 1731                         ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
 1732                         if (V_ip6_dad_count > 0 &&
 1733                             (ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
 1734                                 IF_ADDR_RLOCK(ifp);
 1735                                 TAILQ_FOREACH(ifa, &ifp->if_addrhead,
 1736                                     ifa_link) {
 1737                                         if (ifa->ifa_addr->sa_family !=
 1738                                             AF_INET6)
 1739                                                 continue;
 1740                                         ia = (struct in6_ifaddr *)ifa;
 1741                                         ia->ia6_flags |= IN6_IFF_TENTATIVE;
 1742                                 }
 1743                                 IF_ADDR_RUNLOCK(ifp);
 1744                         }
 1745                 }
 1746 
 1747                 if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
 1748                         if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
 1749                                 /* auto_linklocal 0->1 transision */
 1750 
 1751                                 /* If no link-local address on ifp, configure */
 1752                                 ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
 1753                                 in6_ifattach(ifp, NULL);
 1754                         } else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
 1755                             ifp->if_flags & IFF_UP) {
 1756                                 /*
 1757                                  * When the IF already has
 1758                                  * ND6_IFF_AUTO_LINKLOCAL, no link-local
 1759                                  * address is assigned, and IFF_UP, try to
 1760                                  * assign one.
 1761                                  */
 1762                                 IF_ADDR_RLOCK(ifp);
 1763                                 TAILQ_FOREACH(ifa, &ifp->if_addrhead,
 1764                                     ifa_link) {
 1765                                         if (ifa->ifa_addr->sa_family !=
 1766                                             AF_INET6)
 1767                                                 continue;
 1768                                         ia = (struct in6_ifaddr *)ifa;
 1769                                         if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
 1770                                                 break;
 1771                                 }
 1772                                 IF_ADDR_RUNLOCK(ifp);
 1773                                 if (ifa != NULL)
 1774                                         /* No LLA is configured. */
 1775                                         in6_ifattach(ifp, NULL);
 1776                         }
 1777                 }
 1778         }
 1779                 ND_IFINFO(ifp)->flags = ND.flags;
 1780                 break;
 1781 #undef ND
 1782         case SIOCSNDFLUSH_IN6:  /* XXX: the ioctl name is confusing... */
 1783                 /* sync kernel routing table with the default router list */
 1784                 defrouter_reset();
 1785                 defrouter_select();
 1786                 break;
 1787         case SIOCSPFXFLUSH_IN6:
 1788         {
 1789                 /* flush all the prefix advertised by routers */
 1790                 struct in6_ifaddr *ia, *ia_next;
 1791                 struct nd_prefix *pr, *next;
 1792                 struct nd_prhead prl;
 1793 
 1794                 LIST_INIT(&prl);
 1795 
 1796                 ND6_WLOCK();
 1797                 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
 1798                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1799                                 continue; /* XXX */
 1800                         nd6_prefix_unlink(pr, &prl);
 1801                 }
 1802                 ND6_WUNLOCK();
 1803 
 1804                 while ((pr = LIST_FIRST(&prl)) != NULL) {
 1805                         LIST_REMOVE(pr, ndpr_entry);
 1806                         /* XXXRW: in6_ifaddrhead locking. */
 1807                         TAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
 1808                             ia_next) {
 1809                                 if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1810                                         continue;
 1811 
 1812                                 if (ia->ia6_ndpr == pr)
 1813                                         in6_purgeaddr(&ia->ia_ifa);
 1814                         }
 1815                         nd6_prefix_del(pr);
 1816                 }
 1817                 break;
 1818         }
 1819         case SIOCSRTRFLUSH_IN6:
 1820         {
 1821                 /* flush all the default routers */
 1822                 struct nd_drhead drq;
 1823                 struct nd_defrouter *dr;
 1824 
 1825                 TAILQ_INIT(&drq);
 1826 
 1827                 defrouter_reset();
 1828 
 1829                 ND6_WLOCK();
 1830                 while ((dr = TAILQ_FIRST(&V_nd_defrouter)) != NULL)
 1831                         defrouter_unlink(dr, &drq);
 1832                 ND6_WUNLOCK();
 1833                 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
 1834                         TAILQ_REMOVE(&drq, dr, dr_entry);
 1835                         defrouter_del(dr);
 1836                 }
 1837 
 1838                 defrouter_select();
 1839                 break;
 1840         }
 1841         case SIOCGNBRINFO_IN6:
 1842         {
 1843                 struct llentry *ln;
 1844                 struct in6_addr nb_addr = nbi->addr; /* make local for safety */
 1845 
 1846                 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
 1847                         return (error);
 1848 
 1849                 IF_AFDATA_RLOCK(ifp);
 1850                 ln = nd6_lookup(&nb_addr, 0, ifp);
 1851                 IF_AFDATA_RUNLOCK(ifp);
 1852 
 1853                 if (ln == NULL) {
 1854                         error = EINVAL;
 1855                         break;
 1856                 }
 1857                 nbi->state = ln->ln_state;
 1858                 nbi->asked = ln->la_asked;
 1859                 nbi->isrouter = ln->ln_router;
 1860                 if (ln->la_expire == 0)
 1861                         nbi->expire = 0;
 1862                 else
 1863                         nbi->expire = ln->la_expire + ln->lle_remtime / hz +
 1864                             (time_second - time_uptime);
 1865                 LLE_RUNLOCK(ln);
 1866                 break;
 1867         }
 1868         case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
 1869                 ndif->ifindex = V_nd6_defifindex;
 1870                 break;
 1871         case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
 1872                 return (nd6_setdefaultiface(ndif->ifindex));
 1873         }
 1874         return (error);
 1875 }
 1876 
 1877 /*
 1878  * Calculates new isRouter value based on provided parameters and
 1879  * returns it.
 1880  */
 1881 static int
 1882 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
 1883     int ln_router)
 1884 {
 1885 
 1886         /*
 1887          * ICMP6 type dependent behavior.
 1888          *
 1889          * NS: clear IsRouter if new entry
 1890          * RS: clear IsRouter
 1891          * RA: set IsRouter if there's lladdr
 1892          * redir: clear IsRouter if new entry
 1893          *
 1894          * RA case, (1):
 1895          * The spec says that we must set IsRouter in the following cases:
 1896          * - If lladdr exist, set IsRouter.  This means (1-5).
 1897          * - If it is old entry (!newentry), set IsRouter.  This means (7).
 1898          * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
 1899          * A quetion arises for (1) case.  (1) case has no lladdr in the
 1900          * neighbor cache, this is similar to (6).
 1901          * This case is rare but we figured that we MUST NOT set IsRouter.
 1902          *
 1903          *   is_new  old_addr new_addr      NS  RS  RA  redir
 1904          *                                                      D R
 1905          *      0       n       n       (1)     c   ?     s
 1906          *      0       y       n       (2)     c   s     s
 1907          *      0       n       y       (3)     c   s     s
 1908          *      0       y       y       (4)     c   s     s
 1909          *      0       y       y       (5)     c   s     s
 1910          *      1       --      n       (6) c   c       c s
 1911          *      1       --      y       (7) c   c   s   c s
 1912          *
 1913          *                                      (c=clear s=set)
 1914          */
 1915         switch (type & 0xff) {
 1916         case ND_NEIGHBOR_SOLICIT:
 1917                 /*
 1918                  * New entry must have is_router flag cleared.
 1919                  */
 1920                 if (is_new)                                     /* (6-7) */
 1921                         ln_router = 0;
 1922                 break;
 1923         case ND_REDIRECT:
 1924                 /*
 1925                  * If the icmp is a redirect to a better router, always set the
 1926                  * is_router flag.  Otherwise, if the entry is newly created,
 1927                  * clear the flag.  [RFC 2461, sec 8.3]
 1928                  */
 1929                 if (code == ND_REDIRECT_ROUTER)
 1930                         ln_router = 1;
 1931                 else {
 1932                         if (is_new)                             /* (6-7) */
 1933                                 ln_router = 0;
 1934                 }
 1935                 break;
 1936         case ND_ROUTER_SOLICIT:
 1937                 /*
 1938                  * is_router flag must always be cleared.
 1939                  */
 1940                 ln_router = 0;
 1941                 break;
 1942         case ND_ROUTER_ADVERT:
 1943                 /*
 1944                  * Mark an entry with lladdr as a router.
 1945                  */
 1946                 if ((!is_new && (old_addr || new_addr)) ||      /* (2-5) */
 1947                     (is_new && new_addr)) {                     /* (7) */
 1948                         ln_router = 1;
 1949                 }
 1950                 break;
 1951         }
 1952 
 1953         return (ln_router);
 1954 }
 1955 
 1956 /*
 1957  * Create neighbor cache entry and cache link-layer address,
 1958  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
 1959  *
 1960  * type - ICMP6 type
 1961  * code - type dependent information
 1962  *
 1963  */
 1964 void
 1965 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
 1966     int lladdrlen, int type, int code)
 1967 {
 1968         struct llentry *ln = NULL, *ln_tmp;
 1969         int is_newentry;
 1970         int do_update;
 1971         int olladdr;
 1972         int llchange;
 1973         int flags;
 1974         uint16_t router = 0;
 1975         struct sockaddr_in6 sin6;
 1976         struct mbuf *chain = NULL;
 1977         u_char linkhdr[LLE_MAX_LINKHDR];
 1978         size_t linkhdrsize;
 1979         int lladdr_off;
 1980 
 1981         IF_AFDATA_UNLOCK_ASSERT(ifp);
 1982 
 1983         KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
 1984         KASSERT(from != NULL, ("%s: from == NULL", __func__));
 1985 
 1986         /* nothing must be updated for unspecified address */
 1987         if (IN6_IS_ADDR_UNSPECIFIED(from))
 1988                 return;
 1989 
 1990         /*
 1991          * Validation about ifp->if_addrlen and lladdrlen must be done in
 1992          * the caller.
 1993          *
 1994          * XXX If the link does not have link-layer adderss, what should
 1995          * we do? (ifp->if_addrlen == 0)
 1996          * Spec says nothing in sections for RA, RS and NA.  There's small
 1997          * description on it in NS section (RFC 2461 7.2.3).
 1998          */
 1999         flags = lladdr ? LLE_EXCLUSIVE : 0;
 2000         IF_AFDATA_RLOCK(ifp);
 2001         ln = nd6_lookup(from, flags, ifp);
 2002         IF_AFDATA_RUNLOCK(ifp);
 2003         is_newentry = 0;
 2004         if (ln == NULL) {
 2005                 flags |= LLE_EXCLUSIVE;
 2006                 ln = nd6_alloc(from, 0, ifp);
 2007                 if (ln == NULL)
 2008                         return;
 2009 
 2010                 /*
 2011                  * Since we already know all the data for the new entry,
 2012                  * fill it before insertion.
 2013                  */
 2014                 if (lladdr != NULL) {
 2015                         linkhdrsize = sizeof(linkhdr);
 2016                         if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
 2017                             linkhdr, &linkhdrsize, &lladdr_off) != 0)
 2018                                 return;
 2019                         lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
 2020                             lladdr_off);
 2021                 }
 2022 
 2023                 IF_AFDATA_WLOCK(ifp);
 2024                 LLE_WLOCK(ln);
 2025                 /* Prefer any existing lle over newly-created one */
 2026                 ln_tmp = nd6_lookup(from, LLE_EXCLUSIVE, ifp);
 2027                 if (ln_tmp == NULL)
 2028                         lltable_link_entry(LLTABLE6(ifp), ln);
 2029                 IF_AFDATA_WUNLOCK(ifp);
 2030                 if (ln_tmp == NULL) {
 2031                         /* No existing lle, mark as new entry (6,7) */
 2032                         is_newentry = 1;
 2033                         if (lladdr != NULL) {   /* (7) */
 2034                                 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
 2035                                 EVENTHANDLER_INVOKE(lle_event, ln,
 2036                                     LLENTRY_RESOLVED);
 2037                         }
 2038                 } else {
 2039                         lltable_free_entry(LLTABLE6(ifp), ln);
 2040                         ln = ln_tmp;
 2041                         ln_tmp = NULL;
 2042                 }
 2043         } 
 2044         /* do nothing if static ndp is set */
 2045         if ((ln->la_flags & LLE_STATIC)) {
 2046                 if (flags & LLE_EXCLUSIVE)
 2047                         LLE_WUNLOCK(ln);
 2048                 else
 2049                         LLE_RUNLOCK(ln);
 2050                 return;
 2051         }
 2052 
 2053         olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
 2054         if (olladdr && lladdr) {
 2055                 llchange = bcmp(lladdr, ln->ll_addr,
 2056                     ifp->if_addrlen);
 2057         } else if (!olladdr && lladdr)
 2058                 llchange = 1;
 2059         else
 2060                 llchange = 0;
 2061 
 2062         /*
 2063          * newentry olladdr  lladdr  llchange   (*=record)
 2064          *      0       n       n       --      (1)
 2065          *      0       y       n       --      (2)
 2066          *      0       n       y       y       (3) * STALE
 2067          *      0       y       y       n       (4) *
 2068          *      0       y       y       y       (5) * STALE
 2069          *      1       --      n       --      (6)   NOSTATE(= PASSIVE)
 2070          *      1       --      y       --      (7) * STALE
 2071          */
 2072 
 2073         do_update = 0;
 2074         if (is_newentry == 0 && llchange != 0) {
 2075                 do_update = 1;  /* (3,5) */
 2076 
 2077                 /*
 2078                  * Record source link-layer address
 2079                  * XXX is it dependent to ifp->if_type?
 2080                  */
 2081                 linkhdrsize = sizeof(linkhdr);
 2082                 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
 2083                     linkhdr, &linkhdrsize, &lladdr_off) != 0)
 2084                         return;
 2085 
 2086                 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
 2087                     lladdr_off) == 0) {
 2088                         /* Entry was deleted */
 2089                         return;
 2090                 }
 2091 
 2092                 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
 2093 
 2094                 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
 2095 
 2096                 if (ln->la_hold != NULL)
 2097                         nd6_grab_holdchain(ln, &chain, &sin6);
 2098         }
 2099 
 2100         /* Calculates new router status */
 2101         router = nd6_is_router(type, code, is_newentry, olladdr,
 2102             lladdr != NULL ? 1 : 0, ln->ln_router);
 2103 
 2104         ln->ln_router = router;
 2105         /* Mark non-router redirects with special flag */
 2106         if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
 2107                 ln->la_flags |= LLE_REDIRECT;
 2108 
 2109         if (flags & LLE_EXCLUSIVE)
 2110                 LLE_WUNLOCK(ln);
 2111         else
 2112                 LLE_RUNLOCK(ln);
 2113 
 2114         if (chain != NULL)
 2115                 nd6_flush_holdchain(ifp, ifp, chain, &sin6);
 2116         
 2117         /*
 2118          * When the link-layer address of a router changes, select the
 2119          * best router again.  In particular, when the neighbor entry is newly
 2120          * created, it might affect the selection policy.
 2121          * Question: can we restrict the first condition to the "is_newentry"
 2122          * case?
 2123          * XXX: when we hear an RA from a new router with the link-layer
 2124          * address option, defrouter_select_fib() is called twice, since
 2125          * defrtrlist_update called the function as well.  However, I believe
 2126          * we can compromise the overhead, since it only happens the first
 2127          * time.
 2128          * XXX: although defrouter_select_fib() should not have a bad effect
 2129          * for those are not autoconfigured hosts, we explicitly avoid such
 2130          * cases for safety.
 2131          */
 2132         if ((do_update || is_newentry) && router &&
 2133             ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 2134                 /*
 2135                  * guaranteed recursion
 2136                  */
 2137                 defrouter_select_fib(ifp->if_fib);
 2138         }
 2139 }
 2140 
 2141 static void
 2142 nd6_slowtimo(void *arg)
 2143 {
 2144         CURVNET_SET((struct vnet *) arg);
 2145         struct nd_ifinfo *nd6if;
 2146         struct ifnet *ifp;
 2147 
 2148         callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
 2149             nd6_slowtimo, curvnet);
 2150         IFNET_RLOCK_NOSLEEP();
 2151         TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 2152                 if (ifp->if_afdata[AF_INET6] == NULL)
 2153                         continue;
 2154                 nd6if = ND_IFINFO(ifp);
 2155                 if (nd6if->basereachable && /* already initialized */
 2156                     (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
 2157                         /*
 2158                          * Since reachable time rarely changes by router
 2159                          * advertisements, we SHOULD insure that a new random
 2160                          * value gets recomputed at least once every few hours.
 2161                          * (RFC 2461, 6.3.4)
 2162                          */
 2163                         nd6if->recalctm = V_nd6_recalc_reachtm_interval;
 2164                         nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
 2165                 }
 2166         }
 2167         IFNET_RUNLOCK_NOSLEEP();
 2168         CURVNET_RESTORE();
 2169 }
 2170 
 2171 void
 2172 nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
 2173     struct sockaddr_in6 *sin6)
 2174 {
 2175 
 2176         LLE_WLOCK_ASSERT(ln);
 2177 
 2178         *chain = ln->la_hold;
 2179         ln->la_hold = NULL;
 2180         lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
 2181 
 2182         if (ln->ln_state == ND6_LLINFO_STALE) {
 2183 
 2184                 /*
 2185                  * The first time we send a packet to a
 2186                  * neighbor whose entry is STALE, we have
 2187                  * to change the state to DELAY and a sets
 2188                  * a timer to expire in DELAY_FIRST_PROBE_TIME
 2189                  * seconds to ensure do neighbor unreachability
 2190                  * detection on expiration.
 2191                  * (RFC 2461 7.3.3)
 2192                  */
 2193                 nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
 2194         }
 2195 }
 2196 
 2197 int
 2198 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
 2199     struct sockaddr_in6 *dst, struct route *ro)
 2200 {
 2201         int error;
 2202         int ip6len;
 2203         struct ip6_hdr *ip6;
 2204         struct m_tag *mtag;
 2205 
 2206 #ifdef MAC
 2207         mac_netinet6_nd6_send(ifp, m);
 2208 #endif
 2209 
 2210         /*
 2211          * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
 2212          * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
 2213          * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
 2214          * to be diverted to user space.  When re-injected into the kernel,
 2215          * send_output() will directly dispatch them to the outgoing interface.
 2216          */
 2217         if (send_sendso_input_hook != NULL) {
 2218                 mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
 2219                 if (mtag != NULL) {
 2220                         ip6 = mtod(m, struct ip6_hdr *);
 2221                         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 2222                         /* Use the SEND socket */
 2223                         error = send_sendso_input_hook(m, ifp, SND_OUT,
 2224                             ip6len);
 2225                         /* -1 == no app on SEND socket */
 2226                         if (error == 0 || error != -1)
 2227                             return (error);
 2228                 }
 2229         }
 2230 
 2231         m_clrprotoflags(m);     /* Avoid confusing lower layers. */
 2232         IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
 2233             mtod(m, struct ip6_hdr *));
 2234 
 2235         if ((ifp->if_flags & IFF_LOOPBACK) == 0)
 2236                 origifp = ifp;
 2237 
 2238         error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
 2239         return (error);
 2240 }
 2241 
 2242 /*
 2243  * Lookup link headerfor @sa_dst address. Stores found
 2244  * data in @desten buffer. Copy of lle ln_flags can be also
 2245  * saved in @pflags if @pflags is non-NULL.
 2246  *
 2247  * If destination LLE does not exists or lle state modification
 2248  * is required, call "slow" version.
 2249  *
 2250  * Return values:
 2251  * - 0 on success (address copied to buffer).
 2252  * - EWOULDBLOCK (no local error, but address is still unresolved)
 2253  * - other errors (alloc failure, etc)
 2254  */
 2255 int
 2256 nd6_resolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
 2257     const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
 2258     struct llentry **plle)
 2259 {
 2260         struct llentry *ln = NULL;
 2261         const struct sockaddr_in6 *dst6;
 2262 
 2263         if (pflags != NULL)
 2264                 *pflags = 0;
 2265 
 2266         dst6 = (const struct sockaddr_in6 *)sa_dst;
 2267 
 2268         /* discard the packet if IPv6 operation is disabled on the interface */
 2269         if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
 2270                 m_freem(m);
 2271                 return (ENETDOWN); /* better error? */
 2272         }
 2273 
 2274         if (m != NULL && m->m_flags & M_MCAST) {
 2275                 switch (ifp->if_type) {
 2276                 case IFT_ETHER:
 2277                 case IFT_FDDI:
 2278                 case IFT_L2VLAN:
 2279                 case IFT_IEEE80211:
 2280                 case IFT_BRIDGE:
 2281                 case IFT_ISO88025:
 2282                         ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
 2283                                                  desten);
 2284                         return (0);
 2285                 default:
 2286                         m_freem(m);
 2287                         return (EAFNOSUPPORT);
 2288                 }
 2289         }
 2290 
 2291         IF_AFDATA_RLOCK(ifp);
 2292         ln = nd6_lookup(&dst6->sin6_addr, plle ? LLE_EXCLUSIVE : LLE_UNLOCKED,
 2293             ifp);
 2294         if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
 2295                 /* Entry found, let's copy lle info */
 2296                 bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
 2297                 if (pflags != NULL)
 2298                         *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
 2299                 /* Check if we have feedback request from nd6 timer */
 2300                 if (ln->r_skip_req != 0) {
 2301                         LLE_REQ_LOCK(ln);
 2302                         ln->r_skip_req = 0; /* Notify that entry was used */
 2303                         ln->lle_hittime = time_uptime;
 2304                         LLE_REQ_UNLOCK(ln);
 2305                 }
 2306                 if (plle) {
 2307                         LLE_ADDREF(ln);
 2308                         *plle = ln;
 2309                         LLE_WUNLOCK(ln);
 2310                 }
 2311                 IF_AFDATA_RUNLOCK(ifp);
 2312                 return (0);
 2313         } else if (plle && ln)
 2314                 LLE_WUNLOCK(ln);
 2315         IF_AFDATA_RUNLOCK(ifp);
 2316 
 2317         return (nd6_resolve_slow(ifp, 0, m, dst6, desten, pflags, plle));
 2318 }
 2319 
 2320 
 2321 /*
 2322  * Do L2 address resolution for @sa_dst address. Stores found
 2323  * address in @desten buffer. Copy of lle ln_flags can be also
 2324  * saved in @pflags if @pflags is non-NULL.
 2325  *
 2326  * Heavy version.
 2327  * Function assume that destination LLE does not exist,
 2328  * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
 2329  *
 2330  * Set noinline to be dtrace-friendly
 2331  */
 2332 static __noinline int
 2333 nd6_resolve_slow(struct ifnet *ifp, int flags, struct mbuf *m,
 2334     const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
 2335     struct llentry **plle)
 2336 {
 2337         struct llentry *lle = NULL, *lle_tmp;
 2338         struct in6_addr *psrc, src;
 2339         int send_ns, ll_len;
 2340         char *lladdr;
 2341 
 2342         /*
 2343          * Address resolution or Neighbor Unreachability Detection
 2344          * for the next hop.
 2345          * At this point, the destination of the packet must be a unicast
 2346          * or an anycast address(i.e. not a multicast).
 2347          */
 2348         if (lle == NULL) {
 2349                 IF_AFDATA_RLOCK(ifp);
 2350                 lle = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
 2351                 IF_AFDATA_RUNLOCK(ifp);
 2352                 if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp))  {
 2353                         /*
 2354                          * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
 2355                          * the condition below is not very efficient.  But we believe
 2356                          * it is tolerable, because this should be a rare case.
 2357                          */
 2358                         lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
 2359                         if (lle == NULL) {
 2360                                 char ip6buf[INET6_ADDRSTRLEN];
 2361                                 log(LOG_DEBUG,
 2362                                     "nd6_output: can't allocate llinfo for %s "
 2363                                     "(ln=%p)\n",
 2364                                     ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
 2365                                 m_freem(m);
 2366                                 return (ENOBUFS);
 2367                         }
 2368 
 2369                         IF_AFDATA_WLOCK(ifp);
 2370                         LLE_WLOCK(lle);
 2371                         /* Prefer any existing entry over newly-created one */
 2372                         lle_tmp = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
 2373                         if (lle_tmp == NULL)
 2374                                 lltable_link_entry(LLTABLE6(ifp), lle);
 2375                         IF_AFDATA_WUNLOCK(ifp);
 2376                         if (lle_tmp != NULL) {
 2377                                 lltable_free_entry(LLTABLE6(ifp), lle);
 2378                                 lle = lle_tmp;
 2379                                 lle_tmp = NULL;
 2380                         }
 2381                 }
 2382         } 
 2383         if (lle == NULL) {
 2384                 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
 2385                         m_freem(m);
 2386                         return (ENOBUFS);
 2387                 }
 2388 
 2389                 if (m != NULL)
 2390                         m_freem(m);
 2391                 return (ENOBUFS);
 2392         }
 2393 
 2394         LLE_WLOCK_ASSERT(lle);
 2395 
 2396         /*
 2397          * The first time we send a packet to a neighbor whose entry is
 2398          * STALE, we have to change the state to DELAY and a sets a timer to
 2399          * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
 2400          * neighbor unreachability detection on expiration.
 2401          * (RFC 2461 7.3.3)
 2402          */
 2403         if (lle->ln_state == ND6_LLINFO_STALE)
 2404                 nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
 2405 
 2406         /*
 2407          * If the neighbor cache entry has a state other than INCOMPLETE
 2408          * (i.e. its link-layer address is already resolved), just
 2409          * send the packet.
 2410          */
 2411         if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
 2412                 if (flags & LLE_ADDRONLY) {
 2413                         lladdr = lle->ll_addr;
 2414                         ll_len = ifp->if_addrlen;
 2415                 } else {
 2416                         lladdr = lle->r_linkdata;
 2417                         ll_len = lle->r_hdrlen;
 2418                 }
 2419                 bcopy(lladdr, desten, ll_len);
 2420                 if (pflags != NULL)
 2421                         *pflags = lle->la_flags;
 2422                 if (plle) {
 2423                         LLE_ADDREF(lle);
 2424                         *plle = lle;
 2425                 }
 2426                 LLE_WUNLOCK(lle);
 2427                 return (0);
 2428         }
 2429 
 2430         /*
 2431          * There is a neighbor cache entry, but no ethernet address
 2432          * response yet.  Append this latest packet to the end of the
 2433          * packet queue in the mbuf.  When it exceeds nd6_maxqueuelen,
 2434          * the oldest packet in the queue will be removed.
 2435          */
 2436 
 2437         if (lle->la_hold != NULL) {
 2438                 struct mbuf *m_hold;
 2439                 int i;
 2440                 
 2441                 i = 0;
 2442                 for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){
 2443                         i++;
 2444                         if (m_hold->m_nextpkt == NULL) {
 2445                                 m_hold->m_nextpkt = m;
 2446                                 break;
 2447                         }
 2448                 }
 2449                 while (i >= V_nd6_maxqueuelen) {
 2450                         m_hold = lle->la_hold;
 2451                         lle->la_hold = lle->la_hold->m_nextpkt;
 2452                         m_freem(m_hold);
 2453                         i--;
 2454                 }
 2455         } else {
 2456                 lle->la_hold = m;
 2457         }
 2458 
 2459         /*
 2460          * If there has been no NS for the neighbor after entering the
 2461          * INCOMPLETE state, send the first solicitation.
 2462          * Note that for newly-created lle la_asked will be 0,
 2463          * so we will transition from ND6_LLINFO_NOSTATE to
 2464          * ND6_LLINFO_INCOMPLETE state here.
 2465          */
 2466         psrc = NULL;
 2467         send_ns = 0;
 2468         if (lle->la_asked == 0) {
 2469                 lle->la_asked++;
 2470                 send_ns = 1;
 2471                 psrc = nd6_llinfo_get_holdsrc(lle, &src);
 2472 
 2473                 nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
 2474         }
 2475         LLE_WUNLOCK(lle);
 2476         if (send_ns != 0)
 2477                 nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
 2478 
 2479         return (EWOULDBLOCK);
 2480 }
 2481 
 2482 /*
 2483  * Do L2 address resolution for @sa_dst address. Stores found
 2484  * address in @desten buffer. Copy of lle ln_flags can be also
 2485  * saved in @pflags if @pflags is non-NULL.
 2486  *
 2487  * Return values:
 2488  * - 0 on success (address copied to buffer).
 2489  * - EWOULDBLOCK (no local error, but address is still unresolved)
 2490  * - other errors (alloc failure, etc)
 2491  */
 2492 int
 2493 nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
 2494     char *desten, uint32_t *pflags)
 2495 {
 2496         int error;
 2497 
 2498         flags |= LLE_ADDRONLY;
 2499         error = nd6_resolve_slow(ifp, flags, NULL,
 2500             (const struct sockaddr_in6 *)dst, desten, pflags, NULL);
 2501         return (error);
 2502 }
 2503 
 2504 int
 2505 nd6_flush_holdchain(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
 2506     struct sockaddr_in6 *dst)
 2507 {
 2508         struct mbuf *m, *m_head;
 2509         struct ifnet *outifp;
 2510         int error = 0;
 2511 
 2512         m_head = chain;
 2513         if ((ifp->if_flags & IFF_LOOPBACK) != 0)
 2514                 outifp = origifp;
 2515         else
 2516                 outifp = ifp;
 2517         
 2518         while (m_head) {
 2519                 m = m_head;
 2520                 m_head = m_head->m_nextpkt;
 2521                 error = nd6_output_ifp(ifp, origifp, m, dst, NULL);
 2522         }
 2523 
 2524         /*
 2525          * XXX
 2526          * note that intermediate errors are blindly ignored
 2527          */
 2528         return (error);
 2529 }       
 2530 
 2531 static int
 2532 nd6_need_cache(struct ifnet *ifp)
 2533 {
 2534         /*
 2535          * XXX: we currently do not make neighbor cache on any interface
 2536          * other than ARCnet, Ethernet, FDDI and GIF.
 2537          *
 2538          * RFC2893 says:
 2539          * - unidirectional tunnels needs no ND
 2540          */
 2541         switch (ifp->if_type) {
 2542         case IFT_ARCNET:
 2543         case IFT_ETHER:
 2544         case IFT_FDDI:
 2545         case IFT_IEEE1394:
 2546         case IFT_L2VLAN:
 2547         case IFT_IEEE80211:
 2548         case IFT_INFINIBAND:
 2549         case IFT_BRIDGE:
 2550         case IFT_PROPVIRTUAL:
 2551                 return (1);
 2552         default:
 2553                 return (0);
 2554         }
 2555 }
 2556 
 2557 /*
 2558  * Add pernament ND6 link-layer record for given
 2559  * interface address.
 2560  *
 2561  * Very similar to IPv4 arp_ifinit(), but:
 2562  * 1) IPv6 DAD is performed in different place
 2563  * 2) It is called by IPv6 protocol stack in contrast to
 2564  * arp_ifinit() which is typically called in SIOCSIFADDR
 2565  * driver ioctl handler.
 2566  *
 2567  */
 2568 int
 2569 nd6_add_ifa_lle(struct in6_ifaddr *ia)
 2570 {
 2571         struct ifnet *ifp;
 2572         struct llentry *ln, *ln_tmp;
 2573         struct sockaddr *dst;
 2574 
 2575         ifp = ia->ia_ifa.ifa_ifp;
 2576         if (nd6_need_cache(ifp) == 0)
 2577                 return (0);
 2578 
 2579         ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
 2580         dst = (struct sockaddr *)&ia->ia_addr;
 2581         ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
 2582         if (ln == NULL)
 2583                 return (ENOBUFS);
 2584 
 2585         IF_AFDATA_WLOCK(ifp);
 2586         LLE_WLOCK(ln);
 2587         /* Unlink any entry if exists */
 2588         ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
 2589         if (ln_tmp != NULL)
 2590                 lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
 2591         lltable_link_entry(LLTABLE6(ifp), ln);
 2592         IF_AFDATA_WUNLOCK(ifp);
 2593 
 2594         if (ln_tmp != NULL)
 2595                 EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
 2596         EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
 2597 
 2598         LLE_WUNLOCK(ln);
 2599         if (ln_tmp != NULL)
 2600                 llentry_free(ln_tmp);
 2601 
 2602         return (0);
 2603 }
 2604 
 2605 /*
 2606  * Removes either all lle entries for given @ia, or lle
 2607  * corresponding to @ia address.
 2608  */
 2609 void
 2610 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
 2611 {
 2612         struct sockaddr_in6 mask, addr;
 2613         struct sockaddr *saddr, *smask;
 2614         struct ifnet *ifp;
 2615 
 2616         ifp = ia->ia_ifa.ifa_ifp;
 2617         memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
 2618         memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
 2619         saddr = (struct sockaddr *)&addr;
 2620         smask = (struct sockaddr *)&mask;
 2621 
 2622         if (all != 0)
 2623                 lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
 2624         else
 2625                 lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
 2626 }
 2627 
 2628 static void 
 2629 clear_llinfo_pqueue(struct llentry *ln)
 2630 {
 2631         struct mbuf *m_hold, *m_hold_next;
 2632 
 2633         for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
 2634                 m_hold_next = m_hold->m_nextpkt;
 2635                 m_freem(m_hold);
 2636         }
 2637 
 2638         ln->la_hold = NULL;
 2639 }
 2640 
 2641 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
 2642 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
 2643 
 2644 SYSCTL_DECL(_net_inet6_icmp6);
 2645 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
 2646         CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
 2647         NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
 2648         "NDP default router list");
 2649 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
 2650         CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
 2651         NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
 2652         "NDP prefix list");
 2653 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
 2654         CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
 2655 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
 2656         CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
 2657 
 2658 static int
 2659 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
 2660 {
 2661         struct in6_defrouter d;
 2662         struct nd_defrouter *dr;
 2663         int error;
 2664 
 2665         if (req->newptr != NULL)
 2666                 return (EPERM);
 2667 
 2668         error = sysctl_wire_old_buffer(req, 0);
 2669         if (error != 0)
 2670                 return (error);
 2671 
 2672         bzero(&d, sizeof(d));
 2673         d.rtaddr.sin6_family = AF_INET6;
 2674         d.rtaddr.sin6_len = sizeof(d.rtaddr);
 2675 
 2676         ND6_RLOCK();
 2677         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
 2678                 d.rtaddr.sin6_addr = dr->rtaddr;
 2679                 error = sa6_recoverscope(&d.rtaddr);
 2680                 if (error != 0)
 2681                         break;
 2682                 d.flags = dr->raflags;
 2683                 d.rtlifetime = dr->rtlifetime;
 2684                 d.expire = dr->expire + (time_second - time_uptime);
 2685                 d.if_index = dr->ifp->if_index;
 2686                 error = SYSCTL_OUT(req, &d, sizeof(d));
 2687                 if (error != 0)
 2688                         break;
 2689         }
 2690         ND6_RUNLOCK();
 2691         return (error);
 2692 }
 2693 
 2694 static int
 2695 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
 2696 {
 2697         struct in6_prefix p;
 2698         struct sockaddr_in6 s6;
 2699         struct nd_prefix *pr;
 2700         struct nd_pfxrouter *pfr;
 2701         time_t maxexpire;
 2702         int error;
 2703         char ip6buf[INET6_ADDRSTRLEN];
 2704 
 2705         if (req->newptr)
 2706                 return (EPERM);
 2707 
 2708         error = sysctl_wire_old_buffer(req, 0);
 2709         if (error != 0)
 2710                 return (error);
 2711 
 2712         bzero(&p, sizeof(p));
 2713         p.origin = PR_ORIG_RA;
 2714         bzero(&s6, sizeof(s6));
 2715         s6.sin6_family = AF_INET6;
 2716         s6.sin6_len = sizeof(s6);
 2717 
 2718         ND6_RLOCK();
 2719         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 2720                 p.prefix = pr->ndpr_prefix;
 2721                 if (sa6_recoverscope(&p.prefix)) {
 2722                         log(LOG_ERR, "scope error in prefix list (%s)\n",
 2723                             ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
 2724                         /* XXX: press on... */
 2725                 }
 2726                 p.raflags = pr->ndpr_raf;
 2727                 p.prefixlen = pr->ndpr_plen;
 2728                 p.vltime = pr->ndpr_vltime;
 2729                 p.pltime = pr->ndpr_pltime;
 2730                 p.if_index = pr->ndpr_ifp->if_index;
 2731                 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
 2732                         p.expire = 0;
 2733                 else {
 2734                         /* XXX: we assume time_t is signed. */
 2735                         maxexpire = (-1) &
 2736                             ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
 2737                         if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
 2738                                 p.expire = pr->ndpr_lastupdate +
 2739                                     pr->ndpr_vltime +
 2740                                     (time_second - time_uptime);
 2741                         else
 2742                                 p.expire = maxexpire;
 2743                 }
 2744                 p.refcnt = pr->ndpr_addrcnt;
 2745                 p.flags = pr->ndpr_stateflags;
 2746                 p.advrtrs = 0;
 2747                 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
 2748                         p.advrtrs++;
 2749                 error = SYSCTL_OUT(req, &p, sizeof(p));
 2750                 if (error != 0)
 2751                         break;
 2752                 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
 2753                         s6.sin6_addr = pfr->router->rtaddr;
 2754                         if (sa6_recoverscope(&s6))
 2755                                 log(LOG_ERR,
 2756                                     "scope error in prefix list (%s)\n",
 2757                                     ip6_sprintf(ip6buf, &pfr->router->rtaddr));
 2758                         error = SYSCTL_OUT(req, &s6, sizeof(s6));
 2759                         if (error != 0)
 2760                                 goto out;
 2761                 }
 2762         }
 2763 out:
 2764         ND6_RUNLOCK();
 2765         return (error);
 2766 }

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