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  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the project nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      $KAME: nd6.c,v 1.144 2001/05/24 07:44:00 itojun Exp $
   32  */
   33 
   34 #include <sys/cdefs.h>
   35 __FBSDID("$FreeBSD: stable/12/sys/netinet6/nd6.c 346434 2019-04-20 11:01:47Z markj $");
   36 
   37 #include "opt_inet.h"
   38 #include "opt_inet6.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/callout.h>
   43 #include <sys/lock.h>
   44 #include <sys/malloc.h>
   45 #include <sys/mbuf.h>
   46 #include <sys/mutex.h>
   47 #include <sys/socket.h>
   48 #include <sys/sockio.h>
   49 #include <sys/time.h>
   50 #include <sys/kernel.h>
   51 #include <sys/protosw.h>
   52 #include <sys/errno.h>
   53 #include <sys/syslog.h>
   54 #include <sys/rwlock.h>
   55 #include <sys/queue.h>
   56 #include <sys/sdt.h>
   57 #include <sys/sysctl.h>
   58 
   59 #include <net/if.h>
   60 #include <net/if_var.h>
   61 #include <net/if_dl.h>
   62 #include <net/if_types.h>
   63 #include <net/route.h>
   64 #include <net/vnet.h>
   65 
   66 #include <netinet/in.h>
   67 #include <netinet/in_kdtrace.h>
   68 #include <net/if_llatbl.h>
   69 #include <netinet/if_ether.h>
   70 #include <netinet6/in6_var.h>
   71 #include <netinet/ip6.h>
   72 #include <netinet6/ip6_var.h>
   73 #include <netinet6/scope6_var.h>
   74 #include <netinet6/nd6.h>
   75 #include <netinet6/in6_ifattach.h>
   76 #include <netinet/icmp6.h>
   77 #include <netinet6/send.h>
   78 
   79 #include <sys/limits.h>
   80 
   81 #include <security/mac/mac_framework.h>
   82 
   83 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
   84 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
   85 
   86 #define SIN6(s) ((const struct sockaddr_in6 *)(s))
   87 
   88 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
   89 
   90 /* timer values */
   91 VNET_DEFINE(int, nd6_prune)     = 1;    /* walk list every 1 seconds */
   92 VNET_DEFINE(int, nd6_delay)     = 5;    /* delay first probe time 5 second */
   93 VNET_DEFINE(int, nd6_umaxtries) = 3;    /* maximum unicast query */
   94 VNET_DEFINE(int, nd6_mmaxtries) = 3;    /* maximum multicast query */
   95 VNET_DEFINE(int, nd6_useloopback) = 1;  /* use loopback interface for
   96                                          * local traffic */
   97 VNET_DEFINE(int, nd6_gctimer)   = (60 * 60 * 24); /* 1 day: garbage
   98                                          * collection timer */
   99 
  100 /* preventing too many loops in ND option parsing */
  101 VNET_DEFINE_STATIC(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
  102 
  103 VNET_DEFINE(int, nd6_maxnudhint) = 0;   /* max # of subsequent upper
  104                                          * layer hints */
  105 VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 1; /* max pkts cached in unresolved
  106                                          * ND entries */
  107 #define V_nd6_maxndopt                  VNET(nd6_maxndopt)
  108 #define V_nd6_maxqueuelen               VNET(nd6_maxqueuelen)
  109 
  110 #ifdef ND6_DEBUG
  111 VNET_DEFINE(int, nd6_debug) = 1;
  112 #else
  113 VNET_DEFINE(int, nd6_debug) = 0;
  114 #endif
  115 
  116 static eventhandler_tag lle_event_eh, iflladdr_event_eh;
  117 
  118 VNET_DEFINE(struct nd_drhead, nd_defrouter);
  119 VNET_DEFINE(struct nd_prhead, nd_prefix);
  120 VNET_DEFINE(struct rwlock, nd6_lock);
  121 VNET_DEFINE(uint64_t, nd6_list_genid);
  122 VNET_DEFINE(struct mtx, nd6_onlink_mtx);
  123 
  124 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
  125 #define V_nd6_recalc_reachtm_interval   VNET(nd6_recalc_reachtm_interval)
  126 
  127 int     (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
  128 
  129 static int nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
  130         struct ifnet *);
  131 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
  132 static void nd6_slowtimo(void *);
  133 static int regen_tmpaddr(struct in6_ifaddr *);
  134 static void nd6_free(struct llentry **, int);
  135 static void nd6_free_redirect(const struct llentry *);
  136 static void nd6_llinfo_timer(void *);
  137 static void nd6_llinfo_settimer_locked(struct llentry *, long);
  138 static void clear_llinfo_pqueue(struct llentry *);
  139 static void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
  140 static int nd6_resolve_slow(struct ifnet *, int, struct mbuf *,
  141     const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
  142 static int nd6_need_cache(struct ifnet *);
  143  
  144 
  145 VNET_DEFINE_STATIC(struct callout, nd6_slowtimo_ch);
  146 #define V_nd6_slowtimo_ch               VNET(nd6_slowtimo_ch)
  147 
  148 VNET_DEFINE(struct callout, nd6_timer_ch);
  149 #define V_nd6_timer_ch                  VNET(nd6_timer_ch)
  150 
  151 static void
  152 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
  153 {
  154         struct rt_addrinfo rtinfo;
  155         struct sockaddr_in6 dst;
  156         struct sockaddr_dl gw;
  157         struct ifnet *ifp;
  158         int type;
  159         int fibnum;
  160 
  161         LLE_WLOCK_ASSERT(lle);
  162 
  163         if (lltable_get_af(lle->lle_tbl) != AF_INET6)
  164                 return;
  165 
  166         switch (evt) {
  167         case LLENTRY_RESOLVED:
  168                 type = RTM_ADD;
  169                 KASSERT(lle->la_flags & LLE_VALID,
  170                     ("%s: %p resolved but not valid?", __func__, lle));
  171                 break;
  172         case LLENTRY_EXPIRED:
  173                 type = RTM_DELETE;
  174                 break;
  175         default:
  176                 return;
  177         }
  178 
  179         ifp = lltable_get_ifp(lle->lle_tbl);
  180 
  181         bzero(&dst, sizeof(dst));
  182         bzero(&gw, sizeof(gw));
  183         bzero(&rtinfo, sizeof(rtinfo));
  184         lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
  185         dst.sin6_scope_id = in6_getscopezone(ifp,
  186             in6_addrscope(&dst.sin6_addr));
  187         gw.sdl_len = sizeof(struct sockaddr_dl);
  188         gw.sdl_family = AF_LINK;
  189         gw.sdl_alen = ifp->if_addrlen;
  190         gw.sdl_index = ifp->if_index;
  191         gw.sdl_type = ifp->if_type;
  192         if (evt == LLENTRY_RESOLVED)
  193                 bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
  194         rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
  195         rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
  196         rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
  197         fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib;
  198         rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
  199             type == RTM_ADD ? RTF_UP: 0), 0, fibnum);
  200 }
  201 
  202 /*
  203  * A handler for interface link layer address change event.
  204  */
  205 static void
  206 nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
  207 {
  208 
  209         lltable_update_ifaddr(LLTABLE6(ifp));
  210 }
  211 
  212 void
  213 nd6_init(void)
  214 {
  215 
  216         mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF);
  217         rw_init(&V_nd6_lock, "nd6 list");
  218 
  219         LIST_INIT(&V_nd_prefix);
  220         TAILQ_INIT(&V_nd_defrouter);
  221 
  222         /* Start timers. */
  223         callout_init(&V_nd6_slowtimo_ch, 0);
  224         callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
  225             nd6_slowtimo, curvnet);
  226 
  227         callout_init(&V_nd6_timer_ch, 0);
  228         callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
  229 
  230         nd6_dad_init();
  231         if (IS_DEFAULT_VNET(curvnet)) {
  232                 lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
  233                     NULL, EVENTHANDLER_PRI_ANY);
  234                 iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
  235                     nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
  236         }
  237 }
  238 
  239 #ifdef VIMAGE
  240 void
  241 nd6_destroy()
  242 {
  243 
  244         callout_drain(&V_nd6_slowtimo_ch);
  245         callout_drain(&V_nd6_timer_ch);
  246         if (IS_DEFAULT_VNET(curvnet)) {
  247                 EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
  248                 EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
  249         }
  250         rw_destroy(&V_nd6_lock);
  251         mtx_destroy(&V_nd6_onlink_mtx);
  252 }
  253 #endif
  254 
  255 struct nd_ifinfo *
  256 nd6_ifattach(struct ifnet *ifp)
  257 {
  258         struct nd_ifinfo *nd;
  259 
  260         nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
  261         nd->initialized = 1;
  262 
  263         nd->chlim = IPV6_DEFHLIM;
  264         nd->basereachable = REACHABLE_TIME;
  265         nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
  266         nd->retrans = RETRANS_TIMER;
  267 
  268         nd->flags = ND6_IFF_PERFORMNUD;
  269 
  270         /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
  271          * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
  272          * default regardless of the V_ip6_auto_linklocal configuration to
  273          * give a reasonable default behavior.
  274          */
  275         if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
  276             (ifp->if_flags & IFF_LOOPBACK))
  277                 nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
  278         /*
  279          * A loopback interface does not need to accept RTADV.
  280          * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
  281          * default regardless of the V_ip6_accept_rtadv configuration to
  282          * prevent the interface from accepting RA messages arrived
  283          * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
  284          */
  285         if (V_ip6_accept_rtadv &&
  286             !(ifp->if_flags & IFF_LOOPBACK) &&
  287             (ifp->if_type != IFT_BRIDGE))
  288                         nd->flags |= ND6_IFF_ACCEPT_RTADV;
  289         if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
  290                 nd->flags |= ND6_IFF_NO_RADR;
  291 
  292         /* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
  293         nd6_setmtu0(ifp, nd);
  294 
  295         return nd;
  296 }
  297 
  298 void
  299 nd6_ifdetach(struct ifnet *ifp, struct nd_ifinfo *nd)
  300 {
  301         struct ifaddr *ifa, *next;
  302 
  303         IF_ADDR_RLOCK(ifp);
  304         CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
  305                 if (ifa->ifa_addr->sa_family != AF_INET6)
  306                         continue;
  307 
  308                 /* stop DAD processing */
  309                 nd6_dad_stop(ifa);
  310         }
  311         IF_ADDR_RUNLOCK(ifp);
  312 
  313         free(nd, M_IP6NDP);
  314 }
  315 
  316 /*
  317  * Reset ND level link MTU. This function is called when the physical MTU
  318  * changes, which means we might have to adjust the ND level MTU.
  319  */
  320 void
  321 nd6_setmtu(struct ifnet *ifp)
  322 {
  323         if (ifp->if_afdata[AF_INET6] == NULL)
  324                 return;
  325 
  326         nd6_setmtu0(ifp, ND_IFINFO(ifp));
  327 }
  328 
  329 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
  330 void
  331 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
  332 {
  333         u_int32_t omaxmtu;
  334 
  335         omaxmtu = ndi->maxmtu;
  336         ndi->maxmtu = ifp->if_mtu;
  337 
  338         /*
  339          * Decreasing the interface MTU under IPV6 minimum MTU may cause
  340          * undesirable situation.  We thus notify the operator of the change
  341          * explicitly.  The check for omaxmtu is necessary to restrict the
  342          * log to the case of changing the MTU, not initializing it.
  343          */
  344         if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
  345                 log(LOG_NOTICE, "nd6_setmtu0: "
  346                     "new link MTU on %s (%lu) is too small for IPv6\n",
  347                     if_name(ifp), (unsigned long)ndi->maxmtu);
  348         }
  349 
  350         if (ndi->maxmtu > V_in6_maxmtu)
  351                 in6_setmaxmtu(); /* check all interfaces just in case */
  352 
  353 }
  354 
  355 void
  356 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
  357 {
  358 
  359         bzero(ndopts, sizeof(*ndopts));
  360         ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
  361         ndopts->nd_opts_last
  362                 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
  363 
  364         if (icmp6len == 0) {
  365                 ndopts->nd_opts_done = 1;
  366                 ndopts->nd_opts_search = NULL;
  367         }
  368 }
  369 
  370 /*
  371  * Take one ND option.
  372  */
  373 struct nd_opt_hdr *
  374 nd6_option(union nd_opts *ndopts)
  375 {
  376         struct nd_opt_hdr *nd_opt;
  377         int olen;
  378 
  379         KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
  380         KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
  381             __func__));
  382         if (ndopts->nd_opts_search == NULL)
  383                 return NULL;
  384         if (ndopts->nd_opts_done)
  385                 return NULL;
  386 
  387         nd_opt = ndopts->nd_opts_search;
  388 
  389         /* make sure nd_opt_len is inside the buffer */
  390         if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
  391                 bzero(ndopts, sizeof(*ndopts));
  392                 return NULL;
  393         }
  394 
  395         olen = nd_opt->nd_opt_len << 3;
  396         if (olen == 0) {
  397                 /*
  398                  * Message validation requires that all included
  399                  * options have a length that is greater than zero.
  400                  */
  401                 bzero(ndopts, sizeof(*ndopts));
  402                 return NULL;
  403         }
  404 
  405         ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
  406         if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
  407                 /* option overruns the end of buffer, invalid */
  408                 bzero(ndopts, sizeof(*ndopts));
  409                 return NULL;
  410         } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
  411                 /* reached the end of options chain */
  412                 ndopts->nd_opts_done = 1;
  413                 ndopts->nd_opts_search = NULL;
  414         }
  415         return nd_opt;
  416 }
  417 
  418 /*
  419  * Parse multiple ND options.
  420  * This function is much easier to use, for ND routines that do not need
  421  * multiple options of the same type.
  422  */
  423 int
  424 nd6_options(union nd_opts *ndopts)
  425 {
  426         struct nd_opt_hdr *nd_opt;
  427         int i = 0;
  428 
  429         KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
  430         KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
  431             __func__));
  432         if (ndopts->nd_opts_search == NULL)
  433                 return 0;
  434 
  435         while (1) {
  436                 nd_opt = nd6_option(ndopts);
  437                 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
  438                         /*
  439                          * Message validation requires that all included
  440                          * options have a length that is greater than zero.
  441                          */
  442                         ICMP6STAT_INC(icp6s_nd_badopt);
  443                         bzero(ndopts, sizeof(*ndopts));
  444                         return -1;
  445                 }
  446 
  447                 if (nd_opt == NULL)
  448                         goto skip1;
  449 
  450                 switch (nd_opt->nd_opt_type) {
  451                 case ND_OPT_SOURCE_LINKADDR:
  452                 case ND_OPT_TARGET_LINKADDR:
  453                 case ND_OPT_MTU:
  454                 case ND_OPT_REDIRECTED_HEADER:
  455                 case ND_OPT_NONCE:
  456                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
  457                                 nd6log((LOG_INFO,
  458                                     "duplicated ND6 option found (type=%d)\n",
  459                                     nd_opt->nd_opt_type));
  460                                 /* XXX bark? */
  461                         } else {
  462                                 ndopts->nd_opt_array[nd_opt->nd_opt_type]
  463                                         = nd_opt;
  464                         }
  465                         break;
  466                 case ND_OPT_PREFIX_INFORMATION:
  467                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
  468                                 ndopts->nd_opt_array[nd_opt->nd_opt_type]
  469                                         = nd_opt;
  470                         }
  471                         ndopts->nd_opts_pi_end =
  472                                 (struct nd_opt_prefix_info *)nd_opt;
  473                         break;
  474                 /* What about ND_OPT_ROUTE_INFO? RFC 4191 */
  475                 case ND_OPT_RDNSS:      /* RFC 6106 */
  476                 case ND_OPT_DNSSL:      /* RFC 6106 */
  477                         /*
  478                          * Silently ignore options we know and do not care about
  479                          * in the kernel.
  480                          */
  481                         break;
  482                 default:
  483                         /*
  484                          * Unknown options must be silently ignored,
  485                          * to accommodate future extension to the protocol.
  486                          */
  487                         nd6log((LOG_DEBUG,
  488                             "nd6_options: unsupported option %d - "
  489                             "option ignored\n", nd_opt->nd_opt_type));
  490                 }
  491 
  492 skip1:
  493                 i++;
  494                 if (i > V_nd6_maxndopt) {
  495                         ICMP6STAT_INC(icp6s_nd_toomanyopt);
  496                         nd6log((LOG_INFO, "too many loop in nd opt\n"));
  497                         break;
  498                 }
  499 
  500                 if (ndopts->nd_opts_done)
  501                         break;
  502         }
  503 
  504         return 0;
  505 }
  506 
  507 /*
  508  * ND6 timer routine to handle ND6 entries
  509  */
  510 static void
  511 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
  512 {
  513         int canceled;
  514 
  515         LLE_WLOCK_ASSERT(ln);
  516 
  517         if (tick < 0) {
  518                 ln->la_expire = 0;
  519                 ln->ln_ntick = 0;
  520                 canceled = callout_stop(&ln->lle_timer);
  521         } else {
  522                 ln->la_expire = time_uptime + tick / hz;
  523                 LLE_ADDREF(ln);
  524                 if (tick > INT_MAX) {
  525                         ln->ln_ntick = tick - INT_MAX;
  526                         canceled = callout_reset(&ln->lle_timer, INT_MAX,
  527                             nd6_llinfo_timer, ln);
  528                 } else {
  529                         ln->ln_ntick = 0;
  530                         canceled = callout_reset(&ln->lle_timer, tick,
  531                             nd6_llinfo_timer, ln);
  532                 }
  533         }
  534         if (canceled > 0)
  535                 LLE_REMREF(ln);
  536 }
  537 
  538 /*
  539  * Gets source address of the first packet in hold queue
  540  * and stores it in @src.
  541  * Returns pointer to @src (if hold queue is not empty) or NULL.
  542  *
  543  * Set noinline to be dtrace-friendly
  544  */
  545 static __noinline struct in6_addr *
  546 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
  547 {
  548         struct ip6_hdr hdr;
  549         struct mbuf *m;
  550 
  551         if (ln->la_hold == NULL)
  552                 return (NULL);
  553 
  554         /*
  555          * assume every packet in la_hold has the same IP header
  556          */
  557         m = ln->la_hold;
  558         if (sizeof(hdr) > m->m_len)
  559                 return (NULL);
  560 
  561         m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
  562         *src = hdr.ip6_src;
  563 
  564         return (src);
  565 }
  566 
  567 /*
  568  * Checks if we need to switch from STALE state.
  569  *
  570  * RFC 4861 requires switching from STALE to DELAY state
  571  * on first packet matching entry, waiting V_nd6_delay and
  572  * transition to PROBE state (if upper layer confirmation was
  573  * not received).
  574  *
  575  * This code performs a bit differently:
  576  * On packet hit we don't change state (but desired state
  577  * can be guessed by control plane). However, after V_nd6_delay
  578  * seconds code will transition to PROBE state (so DELAY state
  579  * is kinda skipped in most situations).
  580  *
  581  * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
  582  * we perform the following upon entering STALE state:
  583  *
  584  * 1) Arm timer to run each V_nd6_delay seconds to make sure that
  585  * if packet was transmitted at the start of given interval, we
  586  * would be able to switch to PROBE state in V_nd6_delay seconds
  587  * as user expects.
  588  *
  589  * 2) Reschedule timer until original V_nd6_gctimer expires keeping
  590  * lle in STALE state (remaining timer value stored in lle_remtime).
  591  *
  592  * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
  593  * seconds ago.
  594  *
  595  * Returns non-zero value if the entry is still STALE (storing
  596  * the next timer interval in @pdelay).
  597  *
  598  * Returns zero value if original timer expired or we need to switch to
  599  * PROBE (store that in @do_switch variable).
  600  */
  601 static int
  602 nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
  603 {
  604         int nd_delay, nd_gctimer, r_skip_req;
  605         time_t lle_hittime;
  606         long delay;
  607 
  608         *do_switch = 0;
  609         nd_gctimer = V_nd6_gctimer;
  610         nd_delay = V_nd6_delay;
  611 
  612         LLE_REQ_LOCK(lle);
  613         r_skip_req = lle->r_skip_req;
  614         lle_hittime = lle->lle_hittime;
  615         LLE_REQ_UNLOCK(lle);
  616 
  617         if (r_skip_req > 0) {
  618 
  619                 /*
  620                  * Nonzero r_skip_req value was set upon entering
  621                  * STALE state. Since value was not changed, no
  622                  * packets were passed using this lle. Ask for
  623                  * timer reschedule and keep STALE state.
  624                  */
  625                 delay = (long)(MIN(nd_gctimer, nd_delay));
  626                 delay *= hz;
  627                 if (lle->lle_remtime > delay)
  628                         lle->lle_remtime -= delay;
  629                 else {
  630                         delay = lle->lle_remtime;
  631                         lle->lle_remtime = 0;
  632                 }
  633 
  634                 if (delay == 0) {
  635 
  636                         /*
  637                          * The original ng6_gctime timeout ended,
  638                          * no more rescheduling.
  639                          */
  640                         return (0);
  641                 }
  642 
  643                 *pdelay = delay;
  644                 return (1);
  645         }
  646 
  647         /*
  648          * Packet received. Verify timestamp
  649          */
  650         delay = (long)(time_uptime - lle_hittime);
  651         if (delay < nd_delay) {
  652 
  653                 /*
  654                  * V_nd6_delay still not passed since the first
  655                  * hit in STALE state.
  656                  * Reshedule timer and return.
  657                  */
  658                 *pdelay = (long)(nd_delay - delay) * hz;
  659                 return (1);
  660         }
  661 
  662         /* Request switching to probe */
  663         *do_switch = 1;
  664         return (0);
  665 }
  666 
  667 
  668 /*
  669  * Switch @lle state to new state optionally arming timers.
  670  *
  671  * Set noinline to be dtrace-friendly
  672  */
  673 __noinline void
  674 nd6_llinfo_setstate(struct llentry *lle, int newstate)
  675 {
  676         struct ifnet *ifp;
  677         int nd_gctimer, nd_delay;
  678         long delay, remtime;
  679 
  680         delay = 0;
  681         remtime = 0;
  682 
  683         switch (newstate) {
  684         case ND6_LLINFO_INCOMPLETE:
  685                 ifp = lle->lle_tbl->llt_ifp;
  686                 delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000;
  687                 break;
  688         case ND6_LLINFO_REACHABLE:
  689                 if (!ND6_LLINFO_PERMANENT(lle)) {
  690                         ifp = lle->lle_tbl->llt_ifp;
  691                         delay = (long)ND_IFINFO(ifp)->reachable * hz;
  692                 }
  693                 break;
  694         case ND6_LLINFO_STALE:
  695 
  696                 /*
  697                  * Notify fast path that we want to know if any packet
  698                  * is transmitted by setting r_skip_req.
  699                  */
  700                 LLE_REQ_LOCK(lle);
  701                 lle->r_skip_req = 1;
  702                 LLE_REQ_UNLOCK(lle);
  703                 nd_delay = V_nd6_delay;
  704                 nd_gctimer = V_nd6_gctimer;
  705 
  706                 delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
  707                 remtime = (long)nd_gctimer * hz - delay;
  708                 break;
  709         case ND6_LLINFO_DELAY:
  710                 lle->la_asked = 0;
  711                 delay = (long)V_nd6_delay * hz;
  712                 break;
  713         }
  714 
  715         if (delay > 0)
  716                 nd6_llinfo_settimer_locked(lle, delay);
  717 
  718         lle->lle_remtime = remtime;
  719         lle->ln_state = newstate;
  720 }
  721 
  722 /*
  723  * Timer-dependent part of nd state machine.
  724  *
  725  * Set noinline to be dtrace-friendly
  726  */
  727 static __noinline void
  728 nd6_llinfo_timer(void *arg)
  729 {
  730         struct llentry *ln;
  731         struct in6_addr *dst, *pdst, *psrc, src;
  732         struct ifnet *ifp;
  733         struct nd_ifinfo *ndi;
  734         int do_switch, send_ns;
  735         long delay;
  736 
  737         KASSERT(arg != NULL, ("%s: arg NULL", __func__));
  738         ln = (struct llentry *)arg;
  739         ifp = lltable_get_ifp(ln->lle_tbl);
  740         CURVNET_SET(ifp->if_vnet);
  741 
  742         ND6_RLOCK();
  743         LLE_WLOCK(ln);
  744         if (callout_pending(&ln->lle_timer)) {
  745                 /*
  746                  * Here we are a bit odd here in the treatment of 
  747                  * active/pending. If the pending bit is set, it got
  748                  * rescheduled before I ran. The active
  749                  * bit we ignore, since if it was stopped
  750                  * in ll_tablefree() and was currently running
  751                  * it would have return 0 so the code would
  752                  * not have deleted it since the callout could
  753                  * not be stopped so we want to go through
  754                  * with the delete here now. If the callout
  755                  * was restarted, the pending bit will be back on and
  756                  * we just want to bail since the callout_reset would
  757                  * return 1 and our reference would have been removed
  758                  * by nd6_llinfo_settimer_locked above since canceled
  759                  * would have been 1.
  760                  */
  761                 LLE_WUNLOCK(ln);
  762                 ND6_RUNLOCK();
  763                 CURVNET_RESTORE();
  764                 return;
  765         }
  766         ndi = ND_IFINFO(ifp);
  767         send_ns = 0;
  768         dst = &ln->r_l3addr.addr6;
  769         pdst = dst;
  770 
  771         if (ln->ln_ntick > 0) {
  772                 if (ln->ln_ntick > INT_MAX) {
  773                         ln->ln_ntick -= INT_MAX;
  774                         nd6_llinfo_settimer_locked(ln, INT_MAX);
  775                 } else {
  776                         ln->ln_ntick = 0;
  777                         nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
  778                 }
  779                 goto done;
  780         }
  781 
  782         if (ln->la_flags & LLE_STATIC) {
  783                 goto done;
  784         }
  785 
  786         if (ln->la_flags & LLE_DELETED) {
  787                 nd6_free(&ln, 0);
  788                 goto done;
  789         }
  790 
  791         switch (ln->ln_state) {
  792         case ND6_LLINFO_INCOMPLETE:
  793                 if (ln->la_asked < V_nd6_mmaxtries) {
  794                         ln->la_asked++;
  795                         send_ns = 1;
  796                         /* Send NS to multicast address */
  797                         pdst = NULL;
  798                 } else {
  799                         struct mbuf *m = ln->la_hold;
  800                         if (m) {
  801                                 struct mbuf *m0;
  802 
  803                                 /*
  804                                  * assuming every packet in la_hold has the
  805                                  * same IP header.  Send error after unlock.
  806                                  */
  807                                 m0 = m->m_nextpkt;
  808                                 m->m_nextpkt = NULL;
  809                                 ln->la_hold = m0;
  810                                 clear_llinfo_pqueue(ln);
  811                         }
  812                         nd6_free(&ln, 0);
  813                         if (m != NULL)
  814                                 icmp6_error2(m, ICMP6_DST_UNREACH,
  815                                     ICMP6_DST_UNREACH_ADDR, 0, ifp);
  816                 }
  817                 break;
  818         case ND6_LLINFO_REACHABLE:
  819                 if (!ND6_LLINFO_PERMANENT(ln))
  820                         nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
  821                 break;
  822 
  823         case ND6_LLINFO_STALE:
  824                 if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
  825 
  826                         /*
  827                          * No packet has used this entry and GC timeout
  828                          * has not been passed. Reshedule timer and
  829                          * return.
  830                          */
  831                         nd6_llinfo_settimer_locked(ln, delay);
  832                         break;
  833                 }
  834 
  835                 if (do_switch == 0) {
  836 
  837                         /*
  838                          * GC timer has ended and entry hasn't been used.
  839                          * Run Garbage collector (RFC 4861, 5.3)
  840                          */
  841                         if (!ND6_LLINFO_PERMANENT(ln))
  842                                 nd6_free(&ln, 1);
  843                         break;
  844                 }
  845 
  846                 /* Entry has been used AND delay timer has ended. */
  847 
  848                 /* FALLTHROUGH */
  849 
  850         case ND6_LLINFO_DELAY:
  851                 if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
  852                         /* We need NUD */
  853                         ln->la_asked = 1;
  854                         nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
  855                         send_ns = 1;
  856                 } else
  857                         nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
  858                 break;
  859         case ND6_LLINFO_PROBE:
  860                 if (ln->la_asked < V_nd6_umaxtries) {
  861                         ln->la_asked++;
  862                         send_ns = 1;
  863                 } else {
  864                         nd6_free(&ln, 0);
  865                 }
  866                 break;
  867         default:
  868                 panic("%s: paths in a dark night can be confusing: %d",
  869                     __func__, ln->ln_state);
  870         }
  871 done:
  872         if (ln != NULL)
  873                 ND6_RUNLOCK();
  874         if (send_ns != 0) {
  875                 nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
  876                 psrc = nd6_llinfo_get_holdsrc(ln, &src);
  877                 LLE_FREE_LOCKED(ln);
  878                 ln = NULL;
  879                 nd6_ns_output(ifp, psrc, pdst, dst, NULL);
  880         }
  881 
  882         if (ln != NULL)
  883                 LLE_FREE_LOCKED(ln);
  884         CURVNET_RESTORE();
  885 }
  886 
  887 
  888 /*
  889  * ND6 timer routine to expire default route list and prefix list
  890  */
  891 void
  892 nd6_timer(void *arg)
  893 {
  894         CURVNET_SET((struct vnet *) arg);
  895         struct nd_drhead drq;
  896         struct nd_prhead prl;
  897         struct nd_defrouter *dr, *ndr;
  898         struct nd_prefix *pr, *npr;
  899         struct ifnet *ifp;
  900         struct in6_ifaddr *ia6, *nia6;
  901         uint64_t genid;
  902 
  903         TAILQ_INIT(&drq);
  904         LIST_INIT(&prl);
  905 
  906         ND6_WLOCK();
  907         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr)
  908                 if (dr->expire && dr->expire < time_uptime)
  909                         defrouter_unlink(dr, &drq);
  910         ND6_WUNLOCK();
  911 
  912         while ((dr = TAILQ_FIRST(&drq)) != NULL) {
  913                 TAILQ_REMOVE(&drq, dr, dr_entry);
  914                 defrouter_del(dr);
  915         }
  916 
  917         /*
  918          * expire interface addresses.
  919          * in the past the loop was inside prefix expiry processing.
  920          * However, from a stricter speci-confrmance standpoint, we should
  921          * rather separate address lifetimes and prefix lifetimes.
  922          *
  923          * XXXRW: in6_ifaddrhead locking.
  924          */
  925   addrloop:
  926         CK_STAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
  927                 /* check address lifetime */
  928                 if (IFA6_IS_INVALID(ia6)) {
  929                         int regen = 0;
  930 
  931                         /*
  932                          * If the expiring address is temporary, try
  933                          * regenerating a new one.  This would be useful when
  934                          * we suspended a laptop PC, then turned it on after a
  935                          * period that could invalidate all temporary
  936                          * addresses.  Although we may have to restart the
  937                          * loop (see below), it must be after purging the
  938                          * address.  Otherwise, we'd see an infinite loop of
  939                          * regeneration.
  940                          */
  941                         if (V_ip6_use_tempaddr &&
  942                             (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
  943                                 if (regen_tmpaddr(ia6) == 0)
  944                                         regen = 1;
  945                         }
  946 
  947                         in6_purgeaddr(&ia6->ia_ifa);
  948 
  949                         if (regen)
  950                                 goto addrloop; /* XXX: see below */
  951                 } else if (IFA6_IS_DEPRECATED(ia6)) {
  952                         int oldflags = ia6->ia6_flags;
  953 
  954                         ia6->ia6_flags |= IN6_IFF_DEPRECATED;
  955 
  956                         /*
  957                          * If a temporary address has just become deprecated,
  958                          * regenerate a new one if possible.
  959                          */
  960                         if (V_ip6_use_tempaddr &&
  961                             (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
  962                             (oldflags & IN6_IFF_DEPRECATED) == 0) {
  963 
  964                                 if (regen_tmpaddr(ia6) == 0) {
  965                                         /*
  966                                          * A new temporary address is
  967                                          * generated.
  968                                          * XXX: this means the address chain
  969                                          * has changed while we are still in
  970                                          * the loop.  Although the change
  971                                          * would not cause disaster (because
  972                                          * it's not a deletion, but an
  973                                          * addition,) we'd rather restart the
  974                                          * loop just for safety.  Or does this
  975                                          * significantly reduce performance??
  976                                          */
  977                                         goto addrloop;
  978                                 }
  979                         }
  980                 } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
  981                         /*
  982                          * Schedule DAD for a tentative address.  This happens
  983                          * if the interface was down or not running
  984                          * when the address was configured.
  985                          */
  986                         int delay;
  987 
  988                         delay = arc4random() %
  989                             (MAX_RTR_SOLICITATION_DELAY * hz);
  990                         nd6_dad_start((struct ifaddr *)ia6, delay);
  991                 } else {
  992                         /*
  993                          * Check status of the interface.  If it is down,
  994                          * mark the address as tentative for future DAD.
  995                          */
  996                         ifp = ia6->ia_ifp;
  997                         if ((ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0 &&
  998                             ((ifp->if_flags & IFF_UP) == 0 ||
  999                             (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
 1000                             (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0)){
 1001                                 ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
 1002                                 ia6->ia6_flags |= IN6_IFF_TENTATIVE;
 1003                         }
 1004 
 1005                         /*
 1006                          * A new RA might have made a deprecated address
 1007                          * preferred.
 1008                          */
 1009                         ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
 1010                 }
 1011         }
 1012 
 1013         ND6_WLOCK();
 1014 restart:
 1015         LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
 1016                 /*
 1017                  * Expire prefixes. Since the pltime is only used for
 1018                  * autoconfigured addresses, pltime processing for prefixes is
 1019                  * not necessary.
 1020                  *
 1021                  * Only unlink after all derived addresses have expired. This
 1022                  * may not occur until two hours after the prefix has expired
 1023                  * per RFC 4862. If the prefix expires before its derived
 1024                  * addresses, mark it off-link. This will be done automatically
 1025                  * after unlinking if no address references remain.
 1026                  */
 1027                 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME ||
 1028                     time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime)
 1029                         continue;
 1030 
 1031                 if (pr->ndpr_addrcnt == 0) {
 1032                         nd6_prefix_unlink(pr, &prl);
 1033                         continue;
 1034                 }
 1035                 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
 1036                         genid = V_nd6_list_genid;
 1037                         nd6_prefix_ref(pr);
 1038                         ND6_WUNLOCK();
 1039                         ND6_ONLINK_LOCK();
 1040                         (void)nd6_prefix_offlink(pr);
 1041                         ND6_ONLINK_UNLOCK();
 1042                         ND6_WLOCK();
 1043                         nd6_prefix_rele(pr);
 1044                         if (genid != V_nd6_list_genid)
 1045                                 goto restart;
 1046                 }
 1047         }
 1048         ND6_WUNLOCK();
 1049 
 1050         while ((pr = LIST_FIRST(&prl)) != NULL) {
 1051                 LIST_REMOVE(pr, ndpr_entry);
 1052                 nd6_prefix_del(pr);
 1053         }
 1054 
 1055         callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
 1056             nd6_timer, curvnet);
 1057 
 1058         CURVNET_RESTORE();
 1059 }
 1060 
 1061 /*
 1062  * ia6 - deprecated/invalidated temporary address
 1063  */
 1064 static int
 1065 regen_tmpaddr(struct in6_ifaddr *ia6)
 1066 {
 1067         struct ifaddr *ifa;
 1068         struct ifnet *ifp;
 1069         struct in6_ifaddr *public_ifa6 = NULL;
 1070 
 1071         ifp = ia6->ia_ifa.ifa_ifp;
 1072         IF_ADDR_RLOCK(ifp);
 1073         CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1074                 struct in6_ifaddr *it6;
 1075 
 1076                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1077                         continue;
 1078 
 1079                 it6 = (struct in6_ifaddr *)ifa;
 1080 
 1081                 /* ignore no autoconf addresses. */
 1082                 if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1083                         continue;
 1084 
 1085                 /* ignore autoconf addresses with different prefixes. */
 1086                 if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
 1087                         continue;
 1088 
 1089                 /*
 1090                  * Now we are looking at an autoconf address with the same
 1091                  * prefix as ours.  If the address is temporary and is still
 1092                  * preferred, do not create another one.  It would be rare, but
 1093                  * could happen, for example, when we resume a laptop PC after
 1094                  * a long period.
 1095                  */
 1096                 if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
 1097                     !IFA6_IS_DEPRECATED(it6)) {
 1098                         public_ifa6 = NULL;
 1099                         break;
 1100                 }
 1101 
 1102                 /*
 1103                  * This is a public autoconf address that has the same prefix
 1104                  * as ours.  If it is preferred, keep it.  We can't break the
 1105                  * loop here, because there may be a still-preferred temporary
 1106                  * address with the prefix.
 1107                  */
 1108                 if (!IFA6_IS_DEPRECATED(it6))
 1109                         public_ifa6 = it6;
 1110         }
 1111         if (public_ifa6 != NULL)
 1112                 ifa_ref(&public_ifa6->ia_ifa);
 1113         IF_ADDR_RUNLOCK(ifp);
 1114 
 1115         if (public_ifa6 != NULL) {
 1116                 int e;
 1117 
 1118                 if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
 1119                         ifa_free(&public_ifa6->ia_ifa);
 1120                         log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
 1121                             " tmp addr,errno=%d\n", e);
 1122                         return (-1);
 1123                 }
 1124                 ifa_free(&public_ifa6->ia_ifa);
 1125                 return (0);
 1126         }
 1127 
 1128         return (-1);
 1129 }
 1130 
 1131 /*
 1132  * Remove prefix and default router list entries corresponding to ifp. Neighbor
 1133  * cache entries are freed in in6_domifdetach().
 1134  */
 1135 void
 1136 nd6_purge(struct ifnet *ifp)
 1137 {
 1138         struct nd_drhead drq;
 1139         struct nd_prhead prl;
 1140         struct nd_defrouter *dr, *ndr;
 1141         struct nd_prefix *pr, *npr;
 1142 
 1143         TAILQ_INIT(&drq);
 1144         LIST_INIT(&prl);
 1145 
 1146         /*
 1147          * Nuke default router list entries toward ifp.
 1148          * We defer removal of default router list entries that is installed
 1149          * in the routing table, in order to keep additional side effects as
 1150          * small as possible.
 1151          */
 1152         ND6_WLOCK();
 1153         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
 1154                 if (dr->installed)
 1155                         continue;
 1156                 if (dr->ifp == ifp)
 1157                         defrouter_unlink(dr, &drq);
 1158         }
 1159         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
 1160                 if (!dr->installed)
 1161                         continue;
 1162                 if (dr->ifp == ifp)
 1163                         defrouter_unlink(dr, &drq);
 1164         }
 1165 
 1166         /*
 1167          * Remove prefixes on ifp. We should have already removed addresses on
 1168          * this interface, so no addresses should be referencing these prefixes.
 1169          */
 1170         LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
 1171                 if (pr->ndpr_ifp == ifp)
 1172                         nd6_prefix_unlink(pr, &prl);
 1173         }
 1174         ND6_WUNLOCK();
 1175 
 1176         /* Delete the unlinked router and prefix objects. */
 1177         while ((dr = TAILQ_FIRST(&drq)) != NULL) {
 1178                 TAILQ_REMOVE(&drq, dr, dr_entry);
 1179                 defrouter_del(dr);
 1180         }
 1181         while ((pr = LIST_FIRST(&prl)) != NULL) {
 1182                 LIST_REMOVE(pr, ndpr_entry);
 1183                 nd6_prefix_del(pr);
 1184         }
 1185 
 1186         /* cancel default outgoing interface setting */
 1187         if (V_nd6_defifindex == ifp->if_index)
 1188                 nd6_setdefaultiface(0);
 1189 
 1190         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 1191                 /* Refresh default router list. */
 1192                 defrouter_select_fib(ifp->if_fib);
 1193         }
 1194 }
 1195 
 1196 /* 
 1197  * the caller acquires and releases the lock on the lltbls
 1198  * Returns the llentry locked
 1199  */
 1200 struct llentry *
 1201 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
 1202 {
 1203         struct sockaddr_in6 sin6;
 1204         struct llentry *ln;
 1205         
 1206         bzero(&sin6, sizeof(sin6));
 1207         sin6.sin6_len = sizeof(struct sockaddr_in6);
 1208         sin6.sin6_family = AF_INET6;
 1209         sin6.sin6_addr = *addr6;
 1210 
 1211         IF_AFDATA_LOCK_ASSERT(ifp);
 1212 
 1213         ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
 1214 
 1215         return (ln);
 1216 }
 1217 
 1218 struct llentry *
 1219 nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
 1220 {
 1221         struct sockaddr_in6 sin6;
 1222         struct llentry *ln;
 1223 
 1224         bzero(&sin6, sizeof(sin6));
 1225         sin6.sin6_len = sizeof(struct sockaddr_in6);
 1226         sin6.sin6_family = AF_INET6;
 1227         sin6.sin6_addr = *addr6;
 1228 
 1229         ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
 1230         if (ln != NULL)
 1231                 ln->ln_state = ND6_LLINFO_NOSTATE;
 1232 
 1233         return (ln);
 1234 }
 1235 
 1236 /*
 1237  * Test whether a given IPv6 address is a neighbor or not, ignoring
 1238  * the actual neighbor cache.  The neighbor cache is ignored in order
 1239  * to not reenter the routing code from within itself.
 1240  */
 1241 static int
 1242 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
 1243 {
 1244         struct nd_prefix *pr;
 1245         struct ifaddr *ifa;
 1246         struct rt_addrinfo info;
 1247         struct sockaddr_in6 rt_key;
 1248         const struct sockaddr *dst6;
 1249         uint64_t genid;
 1250         int error, fibnum;
 1251 
 1252         /*
 1253          * A link-local address is always a neighbor.
 1254          * XXX: a link does not necessarily specify a single interface.
 1255          */
 1256         if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
 1257                 struct sockaddr_in6 sin6_copy;
 1258                 u_int32_t zone;
 1259 
 1260                 /*
 1261                  * We need sin6_copy since sa6_recoverscope() may modify the
 1262                  * content (XXX).
 1263                  */
 1264                 sin6_copy = *addr;
 1265                 if (sa6_recoverscope(&sin6_copy))
 1266                         return (0); /* XXX: should be impossible */
 1267                 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
 1268                         return (0);
 1269                 if (sin6_copy.sin6_scope_id == zone)
 1270                         return (1);
 1271                 else
 1272                         return (0);
 1273         }
 1274 
 1275         bzero(&rt_key, sizeof(rt_key));
 1276         bzero(&info, sizeof(info));
 1277         info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key;
 1278 
 1279         /*
 1280          * If the address matches one of our addresses,
 1281          * it should be a neighbor.
 1282          * If the address matches one of our on-link prefixes, it should be a
 1283          * neighbor.
 1284          */
 1285         ND6_RLOCK();
 1286 restart:
 1287         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 1288                 if (pr->ndpr_ifp != ifp)
 1289                         continue;
 1290 
 1291                 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
 1292                         dst6 = (const struct sockaddr *)&pr->ndpr_prefix;
 1293 
 1294                         /*
 1295                          * We only need to check all FIBs if add_addr_allfibs
 1296                          * is unset. If set, checking any FIB will suffice.
 1297                          */
 1298                         fibnum = V_rt_add_addr_allfibs ? rt_numfibs - 1 : 0;
 1299                         for (; fibnum < rt_numfibs; fibnum++) {
 1300                                 genid = V_nd6_list_genid;
 1301                                 ND6_RUNLOCK();
 1302 
 1303                                 /*
 1304                                  * Restore length field before
 1305                                  * retrying lookup
 1306                                  */
 1307                                 rt_key.sin6_len = sizeof(rt_key);
 1308                                 error = rib_lookup_info(fibnum, dst6, 0, 0,
 1309                                                         &info);
 1310 
 1311                                 ND6_RLOCK();
 1312                                 if (genid != V_nd6_list_genid)
 1313                                         goto restart;
 1314                                 if (error == 0)
 1315                                         break;
 1316                         }
 1317                         if (error != 0)
 1318                                 continue;
 1319 
 1320                         /*
 1321                          * This is the case where multiple interfaces
 1322                          * have the same prefix, but only one is installed 
 1323                          * into the routing table and that prefix entry
 1324                          * is not the one being examined here. In the case
 1325                          * where RADIX_MPATH is enabled, multiple route
 1326                          * entries (of the same rt_key value) will be 
 1327                          * installed because the interface addresses all
 1328                          * differ.
 1329                          */
 1330                         if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
 1331                             &rt_key.sin6_addr))
 1332                                 continue;
 1333                 }
 1334 
 1335                 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
 1336                     &addr->sin6_addr, &pr->ndpr_mask)) {
 1337                         ND6_RUNLOCK();
 1338                         return (1);
 1339                 }
 1340         }
 1341         ND6_RUNLOCK();
 1342 
 1343         /*
 1344          * If the address is assigned on the node of the other side of
 1345          * a p2p interface, the address should be a neighbor.
 1346          */
 1347         if (ifp->if_flags & IFF_POINTOPOINT) {
 1348                 IF_ADDR_RLOCK(ifp);
 1349                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1350                         if (ifa->ifa_addr->sa_family != addr->sin6_family)
 1351                                 continue;
 1352                         if (ifa->ifa_dstaddr != NULL &&
 1353                             sa_equal(addr, ifa->ifa_dstaddr)) {
 1354                                 IF_ADDR_RUNLOCK(ifp);
 1355                                 return 1;
 1356                         }
 1357                 }
 1358                 IF_ADDR_RUNLOCK(ifp);
 1359         }
 1360 
 1361         /*
 1362          * If the default router list is empty, all addresses are regarded
 1363          * as on-link, and thus, as a neighbor.
 1364          */
 1365         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
 1366             TAILQ_EMPTY(&V_nd_defrouter) &&
 1367             V_nd6_defifindex == ifp->if_index) {
 1368                 return (1);
 1369         }
 1370 
 1371         return (0);
 1372 }
 1373 
 1374 
 1375 /*
 1376  * Detect if a given IPv6 address identifies a neighbor on a given link.
 1377  * XXX: should take care of the destination of a p2p link?
 1378  */
 1379 int
 1380 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
 1381 {
 1382         struct llentry *lle;
 1383         int rc = 0;
 1384 
 1385         IF_AFDATA_UNLOCK_ASSERT(ifp);
 1386         if (nd6_is_new_addr_neighbor(addr, ifp))
 1387                 return (1);
 1388 
 1389         /*
 1390          * Even if the address matches none of our addresses, it might be
 1391          * in the neighbor cache.
 1392          */
 1393         IF_AFDATA_RLOCK(ifp);
 1394         if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
 1395                 LLE_RUNLOCK(lle);
 1396                 rc = 1;
 1397         }
 1398         IF_AFDATA_RUNLOCK(ifp);
 1399         return (rc);
 1400 }
 1401 
 1402 /*
 1403  * Free an nd6 llinfo entry.
 1404  * Since the function would cause significant changes in the kernel, DO NOT
 1405  * make it global, unless you have a strong reason for the change, and are sure
 1406  * that the change is safe.
 1407  *
 1408  * Set noinline to be dtrace-friendly
 1409  */
 1410 static __noinline void
 1411 nd6_free(struct llentry **lnp, int gc)
 1412 {
 1413         struct ifnet *ifp;
 1414         struct llentry *ln;
 1415         struct nd_defrouter *dr;
 1416 
 1417         ln = *lnp;
 1418         *lnp = NULL;
 1419 
 1420         LLE_WLOCK_ASSERT(ln);
 1421         ND6_RLOCK_ASSERT();
 1422 
 1423         ifp = lltable_get_ifp(ln->lle_tbl);
 1424         if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0)
 1425                 dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
 1426         else
 1427                 dr = NULL;
 1428         ND6_RUNLOCK();
 1429 
 1430         if ((ln->la_flags & LLE_DELETED) == 0)
 1431                 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
 1432 
 1433         /*
 1434          * we used to have pfctlinput(PRC_HOSTDEAD) here.
 1435          * even though it is not harmful, it was not really necessary.
 1436          */
 1437 
 1438         /* cancel timer */
 1439         nd6_llinfo_settimer_locked(ln, -1);
 1440 
 1441         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 1442                 if (dr != NULL && dr->expire &&
 1443                     ln->ln_state == ND6_LLINFO_STALE && gc) {
 1444                         /*
 1445                          * If the reason for the deletion is just garbage
 1446                          * collection, and the neighbor is an active default
 1447                          * router, do not delete it.  Instead, reset the GC
 1448                          * timer using the router's lifetime.
 1449                          * Simply deleting the entry would affect default
 1450                          * router selection, which is not necessarily a good
 1451                          * thing, especially when we're using router preference
 1452                          * values.
 1453                          * XXX: the check for ln_state would be redundant,
 1454                          *      but we intentionally keep it just in case.
 1455                          */
 1456                         if (dr->expire > time_uptime)
 1457                                 nd6_llinfo_settimer_locked(ln,
 1458                                     (dr->expire - time_uptime) * hz);
 1459                         else
 1460                                 nd6_llinfo_settimer_locked(ln,
 1461                                     (long)V_nd6_gctimer * hz);
 1462 
 1463                         LLE_REMREF(ln);
 1464                         LLE_WUNLOCK(ln);
 1465                         defrouter_rele(dr);
 1466                         return;
 1467                 }
 1468 
 1469                 if (dr) {
 1470                         /*
 1471                          * Unreachablity of a router might affect the default
 1472                          * router selection and on-link detection of advertised
 1473                          * prefixes.
 1474                          */
 1475 
 1476                         /*
 1477                          * Temporarily fake the state to choose a new default
 1478                          * router and to perform on-link determination of
 1479                          * prefixes correctly.
 1480                          * Below the state will be set correctly,
 1481                          * or the entry itself will be deleted.
 1482                          */
 1483                         ln->ln_state = ND6_LLINFO_INCOMPLETE;
 1484                 }
 1485 
 1486                 if (ln->ln_router || dr) {
 1487 
 1488                         /*
 1489                          * We need to unlock to avoid a LOR with rt6_flush() with the
 1490                          * rnh and for the calls to pfxlist_onlink_check() and
 1491                          * defrouter_select_fib() in the block further down for calls
 1492                          * into nd6_lookup().  We still hold a ref.
 1493                          */
 1494                         LLE_WUNLOCK(ln);
 1495 
 1496                         /*
 1497                          * rt6_flush must be called whether or not the neighbor
 1498                          * is in the Default Router List.
 1499                          * See a corresponding comment in nd6_na_input().
 1500                          */
 1501                         rt6_flush(&ln->r_l3addr.addr6, ifp);
 1502                 }
 1503 
 1504                 if (dr) {
 1505                         /*
 1506                          * Since defrouter_select_fib() does not affect the
 1507                          * on-link determination and MIP6 needs the check
 1508                          * before the default router selection, we perform
 1509                          * the check now.
 1510                          */
 1511                         pfxlist_onlink_check();
 1512 
 1513                         /*
 1514                          * Refresh default router list.
 1515                          */
 1516                         defrouter_select_fib(dr->ifp->if_fib);
 1517                 }
 1518 
 1519                 /*
 1520                  * If this entry was added by an on-link redirect, remove the
 1521                  * corresponding host route.
 1522                  */
 1523                 if (ln->la_flags & LLE_REDIRECT)
 1524                         nd6_free_redirect(ln);
 1525 
 1526                 if (ln->ln_router || dr)
 1527                         LLE_WLOCK(ln);
 1528         }
 1529 
 1530         /*
 1531          * Save to unlock. We still hold an extra reference and will not
 1532          * free(9) in llentry_free() if someone else holds one as well.
 1533          */
 1534         LLE_WUNLOCK(ln);
 1535         IF_AFDATA_LOCK(ifp);
 1536         LLE_WLOCK(ln);
 1537         /* Guard against race with other llentry_free(). */
 1538         if (ln->la_flags & LLE_LINKED) {
 1539                 /* Remove callout reference */
 1540                 LLE_REMREF(ln);
 1541                 lltable_unlink_entry(ln->lle_tbl, ln);
 1542         }
 1543         IF_AFDATA_UNLOCK(ifp);
 1544 
 1545         llentry_free(ln);
 1546         if (dr != NULL)
 1547                 defrouter_rele(dr);
 1548 }
 1549 
 1550 static int
 1551 nd6_isdynrte(const struct rtentry *rt, void *xap)
 1552 {
 1553 
 1554         if (rt->rt_flags == (RTF_UP | RTF_HOST | RTF_DYNAMIC))
 1555                 return (1);
 1556 
 1557         return (0);
 1558 }
 1559 /*
 1560  * Remove the rtentry for the given llentry,
 1561  * both of which were installed by a redirect.
 1562  */
 1563 static void
 1564 nd6_free_redirect(const struct llentry *ln)
 1565 {
 1566         int fibnum;
 1567         struct sockaddr_in6 sin6;
 1568         struct rt_addrinfo info;
 1569 
 1570         lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
 1571         memset(&info, 0, sizeof(info));
 1572         info.rti_info[RTAX_DST] = (struct sockaddr *)&sin6;
 1573         info.rti_filter = nd6_isdynrte;
 1574 
 1575         for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
 1576                 rtrequest1_fib(RTM_DELETE, &info, NULL, fibnum);
 1577 }
 1578 
 1579 /*
 1580  * Rejuvenate this function for routing operations related
 1581  * processing.
 1582  */
 1583 void
 1584 nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
 1585 {
 1586         struct sockaddr_in6 *gateway;
 1587         struct nd_defrouter *dr;
 1588         struct ifnet *ifp;
 1589 
 1590         gateway = (struct sockaddr_in6 *)rt->rt_gateway;
 1591         ifp = rt->rt_ifp;
 1592 
 1593         switch (req) {
 1594         case RTM_ADD:
 1595                 break;
 1596 
 1597         case RTM_DELETE:
 1598                 if (!ifp)
 1599                         return;
 1600                 /*
 1601                  * Only indirect routes are interesting.
 1602                  */
 1603                 if ((rt->rt_flags & RTF_GATEWAY) == 0)
 1604                         return;
 1605                 /*
 1606                  * check for default route
 1607                  */
 1608                 if (IN6_ARE_ADDR_EQUAL(&in6addr_any,
 1609                     &SIN6(rt_key(rt))->sin6_addr)) {
 1610                         dr = defrouter_lookup(&gateway->sin6_addr, ifp);
 1611                         if (dr != NULL) {
 1612                                 dr->installed = 0;
 1613                                 defrouter_rele(dr);
 1614                         }
 1615                 }
 1616                 break;
 1617         }
 1618 }
 1619 
 1620 
 1621 int
 1622 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
 1623 {
 1624         struct in6_ndireq *ndi = (struct in6_ndireq *)data;
 1625         struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
 1626         struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
 1627         int error = 0;
 1628 
 1629         if (ifp->if_afdata[AF_INET6] == NULL)
 1630                 return (EPFNOSUPPORT);
 1631         switch (cmd) {
 1632         case OSIOCGIFINFO_IN6:
 1633 #define ND      ndi->ndi
 1634                 /* XXX: old ndp(8) assumes a positive value for linkmtu. */
 1635                 bzero(&ND, sizeof(ND));
 1636                 ND.linkmtu = IN6_LINKMTU(ifp);
 1637                 ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
 1638                 ND.basereachable = ND_IFINFO(ifp)->basereachable;
 1639                 ND.reachable = ND_IFINFO(ifp)->reachable;
 1640                 ND.retrans = ND_IFINFO(ifp)->retrans;
 1641                 ND.flags = ND_IFINFO(ifp)->flags;
 1642                 ND.recalctm = ND_IFINFO(ifp)->recalctm;
 1643                 ND.chlim = ND_IFINFO(ifp)->chlim;
 1644                 break;
 1645         case SIOCGIFINFO_IN6:
 1646                 ND = *ND_IFINFO(ifp);
 1647                 break;
 1648         case SIOCSIFINFO_IN6:
 1649                 /*
 1650                  * used to change host variables from userland.
 1651                  * intended for a use on router to reflect RA configurations.
 1652                  */
 1653                 /* 0 means 'unspecified' */
 1654                 if (ND.linkmtu != 0) {
 1655                         if (ND.linkmtu < IPV6_MMTU ||
 1656                             ND.linkmtu > IN6_LINKMTU(ifp)) {
 1657                                 error = EINVAL;
 1658                                 break;
 1659                         }
 1660                         ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
 1661                 }
 1662 
 1663                 if (ND.basereachable != 0) {
 1664                         int obasereachable = ND_IFINFO(ifp)->basereachable;
 1665 
 1666                         ND_IFINFO(ifp)->basereachable = ND.basereachable;
 1667                         if (ND.basereachable != obasereachable)
 1668                                 ND_IFINFO(ifp)->reachable =
 1669                                     ND_COMPUTE_RTIME(ND.basereachable);
 1670                 }
 1671                 if (ND.retrans != 0)
 1672                         ND_IFINFO(ifp)->retrans = ND.retrans;
 1673                 if (ND.chlim != 0)
 1674                         ND_IFINFO(ifp)->chlim = ND.chlim;
 1675                 /* FALLTHROUGH */
 1676         case SIOCSIFINFO_FLAGS:
 1677         {
 1678                 struct ifaddr *ifa;
 1679                 struct in6_ifaddr *ia;
 1680 
 1681                 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
 1682                     !(ND.flags & ND6_IFF_IFDISABLED)) {
 1683                         /* ifdisabled 1->0 transision */
 1684 
 1685                         /*
 1686                          * If the interface is marked as ND6_IFF_IFDISABLED and
 1687                          * has an link-local address with IN6_IFF_DUPLICATED,
 1688                          * do not clear ND6_IFF_IFDISABLED.
 1689                          * See RFC 4862, Section 5.4.5.
 1690                          */
 1691                         IF_ADDR_RLOCK(ifp);
 1692                         CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1693                                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1694                                         continue;
 1695                                 ia = (struct in6_ifaddr *)ifa;
 1696                                 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
 1697                                     IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
 1698                                         break;
 1699                         }
 1700                         IF_ADDR_RUNLOCK(ifp);
 1701 
 1702                         if (ifa != NULL) {
 1703                                 /* LLA is duplicated. */
 1704                                 ND.flags |= ND6_IFF_IFDISABLED;
 1705                                 log(LOG_ERR, "Cannot enable an interface"
 1706                                     " with a link-local address marked"
 1707                                     " duplicate.\n");
 1708                         } else {
 1709                                 ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
 1710                                 if (ifp->if_flags & IFF_UP)
 1711                                         in6_if_up(ifp);
 1712                         }
 1713                 } else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
 1714                             (ND.flags & ND6_IFF_IFDISABLED)) {
 1715                         /* ifdisabled 0->1 transision */
 1716                         /* Mark all IPv6 address as tentative. */
 1717 
 1718                         ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
 1719                         if (V_ip6_dad_count > 0 &&
 1720                             (ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
 1721                                 IF_ADDR_RLOCK(ifp);
 1722                                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
 1723                                     ifa_link) {
 1724                                         if (ifa->ifa_addr->sa_family !=
 1725                                             AF_INET6)
 1726                                                 continue;
 1727                                         ia = (struct in6_ifaddr *)ifa;
 1728                                         ia->ia6_flags |= IN6_IFF_TENTATIVE;
 1729                                 }
 1730                                 IF_ADDR_RUNLOCK(ifp);
 1731                         }
 1732                 }
 1733 
 1734                 if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
 1735                         if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
 1736                                 /* auto_linklocal 0->1 transision */
 1737 
 1738                                 /* If no link-local address on ifp, configure */
 1739                                 ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
 1740                                 in6_ifattach(ifp, NULL);
 1741                         } else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
 1742                             ifp->if_flags & IFF_UP) {
 1743                                 /*
 1744                                  * When the IF already has
 1745                                  * ND6_IFF_AUTO_LINKLOCAL, no link-local
 1746                                  * address is assigned, and IFF_UP, try to
 1747                                  * assign one.
 1748                                  */
 1749                                 IF_ADDR_RLOCK(ifp);
 1750                                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
 1751                                     ifa_link) {
 1752                                         if (ifa->ifa_addr->sa_family !=
 1753                                             AF_INET6)
 1754                                                 continue;
 1755                                         ia = (struct in6_ifaddr *)ifa;
 1756                                         if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
 1757                                                 break;
 1758                                 }
 1759                                 IF_ADDR_RUNLOCK(ifp);
 1760                                 if (ifa != NULL)
 1761                                         /* No LLA is configured. */
 1762                                         in6_ifattach(ifp, NULL);
 1763                         }
 1764                 }
 1765         }
 1766                 ND_IFINFO(ifp)->flags = ND.flags;
 1767                 break;
 1768 #undef ND
 1769         case SIOCSNDFLUSH_IN6:  /* XXX: the ioctl name is confusing... */
 1770                 /* sync kernel routing table with the default router list */
 1771                 defrouter_reset();
 1772                 defrouter_select();
 1773                 break;
 1774         case SIOCSPFXFLUSH_IN6:
 1775         {
 1776                 /* flush all the prefix advertised by routers */
 1777                 struct in6_ifaddr *ia, *ia_next;
 1778                 struct nd_prefix *pr, *next;
 1779                 struct nd_prhead prl;
 1780 
 1781                 LIST_INIT(&prl);
 1782 
 1783                 ND6_WLOCK();
 1784                 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
 1785                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1786                                 continue; /* XXX */
 1787                         nd6_prefix_unlink(pr, &prl);
 1788                 }
 1789                 ND6_WUNLOCK();
 1790 
 1791                 while ((pr = LIST_FIRST(&prl)) != NULL) {
 1792                         LIST_REMOVE(pr, ndpr_entry);
 1793                         /* XXXRW: in6_ifaddrhead locking. */
 1794                         CK_STAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
 1795                             ia_next) {
 1796                                 if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1797                                         continue;
 1798 
 1799                                 if (ia->ia6_ndpr == pr)
 1800                                         in6_purgeaddr(&ia->ia_ifa);
 1801                         }
 1802                         nd6_prefix_del(pr);
 1803                 }
 1804                 break;
 1805         }
 1806         case SIOCSRTRFLUSH_IN6:
 1807         {
 1808                 /* flush all the default routers */
 1809                 struct nd_drhead drq;
 1810                 struct nd_defrouter *dr;
 1811 
 1812                 TAILQ_INIT(&drq);
 1813 
 1814                 defrouter_reset();
 1815 
 1816                 ND6_WLOCK();
 1817                 while ((dr = TAILQ_FIRST(&V_nd_defrouter)) != NULL)
 1818                         defrouter_unlink(dr, &drq);
 1819                 ND6_WUNLOCK();
 1820                 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
 1821                         TAILQ_REMOVE(&drq, dr, dr_entry);
 1822                         defrouter_del(dr);
 1823                 }
 1824 
 1825                 defrouter_select();
 1826                 break;
 1827         }
 1828         case SIOCGNBRINFO_IN6:
 1829         {
 1830                 struct llentry *ln;
 1831                 struct in6_addr nb_addr = nbi->addr; /* make local for safety */
 1832 
 1833                 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
 1834                         return (error);
 1835 
 1836                 IF_AFDATA_RLOCK(ifp);
 1837                 ln = nd6_lookup(&nb_addr, 0, ifp);
 1838                 IF_AFDATA_RUNLOCK(ifp);
 1839 
 1840                 if (ln == NULL) {
 1841                         error = EINVAL;
 1842                         break;
 1843                 }
 1844                 nbi->state = ln->ln_state;
 1845                 nbi->asked = ln->la_asked;
 1846                 nbi->isrouter = ln->ln_router;
 1847                 if (ln->la_expire == 0)
 1848                         nbi->expire = 0;
 1849                 else
 1850                         nbi->expire = ln->la_expire + ln->lle_remtime / hz +
 1851                             (time_second - time_uptime);
 1852                 LLE_RUNLOCK(ln);
 1853                 break;
 1854         }
 1855         case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
 1856                 ndif->ifindex = V_nd6_defifindex;
 1857                 break;
 1858         case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
 1859                 return (nd6_setdefaultiface(ndif->ifindex));
 1860         }
 1861         return (error);
 1862 }
 1863 
 1864 /*
 1865  * Calculates new isRouter value based on provided parameters and
 1866  * returns it.
 1867  */
 1868 static int
 1869 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
 1870     int ln_router)
 1871 {
 1872 
 1873         /*
 1874          * ICMP6 type dependent behavior.
 1875          *
 1876          * NS: clear IsRouter if new entry
 1877          * RS: clear IsRouter
 1878          * RA: set IsRouter if there's lladdr
 1879          * redir: clear IsRouter if new entry
 1880          *
 1881          * RA case, (1):
 1882          * The spec says that we must set IsRouter in the following cases:
 1883          * - If lladdr exist, set IsRouter.  This means (1-5).
 1884          * - If it is old entry (!newentry), set IsRouter.  This means (7).
 1885          * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
 1886          * A quetion arises for (1) case.  (1) case has no lladdr in the
 1887          * neighbor cache, this is similar to (6).
 1888          * This case is rare but we figured that we MUST NOT set IsRouter.
 1889          *
 1890          *   is_new  old_addr new_addr      NS  RS  RA  redir
 1891          *                                                      D R
 1892          *      0       n       n       (1)     c   ?     s
 1893          *      0       y       n       (2)     c   s     s
 1894          *      0       n       y       (3)     c   s     s
 1895          *      0       y       y       (4)     c   s     s
 1896          *      0       y       y       (5)     c   s     s
 1897          *      1       --      n       (6) c   c       c s
 1898          *      1       --      y       (7) c   c   s   c s
 1899          *
 1900          *                                      (c=clear s=set)
 1901          */
 1902         switch (type & 0xff) {
 1903         case ND_NEIGHBOR_SOLICIT:
 1904                 /*
 1905                  * New entry must have is_router flag cleared.
 1906                  */
 1907                 if (is_new)                                     /* (6-7) */
 1908                         ln_router = 0;
 1909                 break;
 1910         case ND_REDIRECT:
 1911                 /*
 1912                  * If the icmp is a redirect to a better router, always set the
 1913                  * is_router flag.  Otherwise, if the entry is newly created,
 1914                  * clear the flag.  [RFC 2461, sec 8.3]
 1915                  */
 1916                 if (code == ND_REDIRECT_ROUTER)
 1917                         ln_router = 1;
 1918                 else {
 1919                         if (is_new)                             /* (6-7) */
 1920                                 ln_router = 0;
 1921                 }
 1922                 break;
 1923         case ND_ROUTER_SOLICIT:
 1924                 /*
 1925                  * is_router flag must always be cleared.
 1926                  */
 1927                 ln_router = 0;
 1928                 break;
 1929         case ND_ROUTER_ADVERT:
 1930                 /*
 1931                  * Mark an entry with lladdr as a router.
 1932                  */
 1933                 if ((!is_new && (old_addr || new_addr)) ||      /* (2-5) */
 1934                     (is_new && new_addr)) {                     /* (7) */
 1935                         ln_router = 1;
 1936                 }
 1937                 break;
 1938         }
 1939 
 1940         return (ln_router);
 1941 }
 1942 
 1943 /*
 1944  * Create neighbor cache entry and cache link-layer address,
 1945  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
 1946  *
 1947  * type - ICMP6 type
 1948  * code - type dependent information
 1949  *
 1950  */
 1951 void
 1952 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
 1953     int lladdrlen, int type, int code)
 1954 {
 1955         struct llentry *ln = NULL, *ln_tmp;
 1956         int is_newentry;
 1957         int do_update;
 1958         int olladdr;
 1959         int llchange;
 1960         int flags;
 1961         uint16_t router = 0;
 1962         struct sockaddr_in6 sin6;
 1963         struct mbuf *chain = NULL;
 1964         u_char linkhdr[LLE_MAX_LINKHDR];
 1965         size_t linkhdrsize;
 1966         int lladdr_off;
 1967 
 1968         IF_AFDATA_UNLOCK_ASSERT(ifp);
 1969 
 1970         KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
 1971         KASSERT(from != NULL, ("%s: from == NULL", __func__));
 1972 
 1973         /* nothing must be updated for unspecified address */
 1974         if (IN6_IS_ADDR_UNSPECIFIED(from))
 1975                 return;
 1976 
 1977         /*
 1978          * Validation about ifp->if_addrlen and lladdrlen must be done in
 1979          * the caller.
 1980          *
 1981          * XXX If the link does not have link-layer adderss, what should
 1982          * we do? (ifp->if_addrlen == 0)
 1983          * Spec says nothing in sections for RA, RS and NA.  There's small
 1984          * description on it in NS section (RFC 2461 7.2.3).
 1985          */
 1986         flags = lladdr ? LLE_EXCLUSIVE : 0;
 1987         IF_AFDATA_RLOCK(ifp);
 1988         ln = nd6_lookup(from, flags, ifp);
 1989         IF_AFDATA_RUNLOCK(ifp);
 1990         is_newentry = 0;
 1991         if (ln == NULL) {
 1992                 flags |= LLE_EXCLUSIVE;
 1993                 ln = nd6_alloc(from, 0, ifp);
 1994                 if (ln == NULL)
 1995                         return;
 1996 
 1997                 /*
 1998                  * Since we already know all the data for the new entry,
 1999                  * fill it before insertion.
 2000                  */
 2001                 if (lladdr != NULL) {
 2002                         linkhdrsize = sizeof(linkhdr);
 2003                         if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
 2004                             linkhdr, &linkhdrsize, &lladdr_off) != 0)
 2005                                 return;
 2006                         lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
 2007                             lladdr_off);
 2008                 }
 2009 
 2010                 IF_AFDATA_WLOCK(ifp);
 2011                 LLE_WLOCK(ln);
 2012                 /* Prefer any existing lle over newly-created one */
 2013                 ln_tmp = nd6_lookup(from, LLE_EXCLUSIVE, ifp);
 2014                 if (ln_tmp == NULL)
 2015                         lltable_link_entry(LLTABLE6(ifp), ln);
 2016                 IF_AFDATA_WUNLOCK(ifp);
 2017                 if (ln_tmp == NULL) {
 2018                         /* No existing lle, mark as new entry (6,7) */
 2019                         is_newentry = 1;
 2020                         if (lladdr != NULL) {   /* (7) */
 2021                                 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
 2022                                 EVENTHANDLER_INVOKE(lle_event, ln,
 2023                                     LLENTRY_RESOLVED);
 2024                         }
 2025                 } else {
 2026                         lltable_free_entry(LLTABLE6(ifp), ln);
 2027                         ln = ln_tmp;
 2028                         ln_tmp = NULL;
 2029                 }
 2030         } 
 2031         /* do nothing if static ndp is set */
 2032         if ((ln->la_flags & LLE_STATIC)) {
 2033                 if (flags & LLE_EXCLUSIVE)
 2034                         LLE_WUNLOCK(ln);
 2035                 else
 2036                         LLE_RUNLOCK(ln);
 2037                 return;
 2038         }
 2039 
 2040         olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
 2041         if (olladdr && lladdr) {
 2042                 llchange = bcmp(lladdr, ln->ll_addr,
 2043                     ifp->if_addrlen);
 2044         } else if (!olladdr && lladdr)
 2045                 llchange = 1;
 2046         else
 2047                 llchange = 0;
 2048 
 2049         /*
 2050          * newentry olladdr  lladdr  llchange   (*=record)
 2051          *      0       n       n       --      (1)
 2052          *      0       y       n       --      (2)
 2053          *      0       n       y       y       (3) * STALE
 2054          *      0       y       y       n       (4) *
 2055          *      0       y       y       y       (5) * STALE
 2056          *      1       --      n       --      (6)   NOSTATE(= PASSIVE)
 2057          *      1       --      y       --      (7) * STALE
 2058          */
 2059 
 2060         do_update = 0;
 2061         if (is_newentry == 0 && llchange != 0) {
 2062                 do_update = 1;  /* (3,5) */
 2063 
 2064                 /*
 2065                  * Record source link-layer address
 2066                  * XXX is it dependent to ifp->if_type?
 2067                  */
 2068                 linkhdrsize = sizeof(linkhdr);
 2069                 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
 2070                     linkhdr, &linkhdrsize, &lladdr_off) != 0)
 2071                         return;
 2072 
 2073                 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
 2074                     lladdr_off) == 0) {
 2075                         /* Entry was deleted */
 2076                         return;
 2077                 }
 2078 
 2079                 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
 2080 
 2081                 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
 2082 
 2083                 if (ln->la_hold != NULL)
 2084                         nd6_grab_holdchain(ln, &chain, &sin6);
 2085         }
 2086 
 2087         /* Calculates new router status */
 2088         router = nd6_is_router(type, code, is_newentry, olladdr,
 2089             lladdr != NULL ? 1 : 0, ln->ln_router);
 2090 
 2091         ln->ln_router = router;
 2092         /* Mark non-router redirects with special flag */
 2093         if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
 2094                 ln->la_flags |= LLE_REDIRECT;
 2095 
 2096         if (flags & LLE_EXCLUSIVE)
 2097                 LLE_WUNLOCK(ln);
 2098         else
 2099                 LLE_RUNLOCK(ln);
 2100 
 2101         if (chain != NULL)
 2102                 nd6_flush_holdchain(ifp, chain, &sin6);
 2103         
 2104         /*
 2105          * When the link-layer address of a router changes, select the
 2106          * best router again.  In particular, when the neighbor entry is newly
 2107          * created, it might affect the selection policy.
 2108          * Question: can we restrict the first condition to the "is_newentry"
 2109          * case?
 2110          * XXX: when we hear an RA from a new router with the link-layer
 2111          * address option, defrouter_select_fib() is called twice, since
 2112          * defrtrlist_update called the function as well.  However, I believe
 2113          * we can compromise the overhead, since it only happens the first
 2114          * time.
 2115          * XXX: although defrouter_select_fib() should not have a bad effect
 2116          * for those are not autoconfigured hosts, we explicitly avoid such
 2117          * cases for safety.
 2118          */
 2119         if ((do_update || is_newentry) && router &&
 2120             ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 2121                 /*
 2122                  * guaranteed recursion
 2123                  */
 2124                 defrouter_select_fib(ifp->if_fib);
 2125         }
 2126 }
 2127 
 2128 static void
 2129 nd6_slowtimo(void *arg)
 2130 {
 2131         CURVNET_SET((struct vnet *) arg);
 2132         struct nd_ifinfo *nd6if;
 2133         struct ifnet *ifp;
 2134 
 2135         callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
 2136             nd6_slowtimo, curvnet);
 2137         IFNET_RLOCK_NOSLEEP();
 2138         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 2139                 if (ifp->if_afdata[AF_INET6] == NULL)
 2140                         continue;
 2141                 nd6if = ND_IFINFO(ifp);
 2142                 if (nd6if->basereachable && /* already initialized */
 2143                     (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
 2144                         /*
 2145                          * Since reachable time rarely changes by router
 2146                          * advertisements, we SHOULD insure that a new random
 2147                          * value gets recomputed at least once every few hours.
 2148                          * (RFC 2461, 6.3.4)
 2149                          */
 2150                         nd6if->recalctm = V_nd6_recalc_reachtm_interval;
 2151                         nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
 2152                 }
 2153         }
 2154         IFNET_RUNLOCK_NOSLEEP();
 2155         CURVNET_RESTORE();
 2156 }
 2157 
 2158 void
 2159 nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
 2160     struct sockaddr_in6 *sin6)
 2161 {
 2162 
 2163         LLE_WLOCK_ASSERT(ln);
 2164 
 2165         *chain = ln->la_hold;
 2166         ln->la_hold = NULL;
 2167         lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
 2168 
 2169         if (ln->ln_state == ND6_LLINFO_STALE) {
 2170 
 2171                 /*
 2172                  * The first time we send a packet to a
 2173                  * neighbor whose entry is STALE, we have
 2174                  * to change the state to DELAY and a sets
 2175                  * a timer to expire in DELAY_FIRST_PROBE_TIME
 2176                  * seconds to ensure do neighbor unreachability
 2177                  * detection on expiration.
 2178                  * (RFC 2461 7.3.3)
 2179                  */
 2180                 nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
 2181         }
 2182 }
 2183 
 2184 int
 2185 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
 2186     struct sockaddr_in6 *dst, struct route *ro)
 2187 {
 2188         int error;
 2189         int ip6len;
 2190         struct ip6_hdr *ip6;
 2191         struct m_tag *mtag;
 2192 
 2193 #ifdef MAC
 2194         mac_netinet6_nd6_send(ifp, m);
 2195 #endif
 2196 
 2197         /*
 2198          * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
 2199          * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
 2200          * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
 2201          * to be diverted to user space.  When re-injected into the kernel,
 2202          * send_output() will directly dispatch them to the outgoing interface.
 2203          */
 2204         if (send_sendso_input_hook != NULL) {
 2205                 mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
 2206                 if (mtag != NULL) {
 2207                         ip6 = mtod(m, struct ip6_hdr *);
 2208                         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 2209                         /* Use the SEND socket */
 2210                         error = send_sendso_input_hook(m, ifp, SND_OUT,
 2211                             ip6len);
 2212                         /* -1 == no app on SEND socket */
 2213                         if (error == 0 || error != -1)
 2214                             return (error);
 2215                 }
 2216         }
 2217 
 2218         m_clrprotoflags(m);     /* Avoid confusing lower layers. */
 2219         IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
 2220             mtod(m, struct ip6_hdr *));
 2221 
 2222         if ((ifp->if_flags & IFF_LOOPBACK) == 0)
 2223                 origifp = ifp;
 2224 
 2225         error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
 2226         return (error);
 2227 }
 2228 
 2229 /*
 2230  * Lookup link headerfor @sa_dst address. Stores found
 2231  * data in @desten buffer. Copy of lle ln_flags can be also
 2232  * saved in @pflags if @pflags is non-NULL.
 2233  *
 2234  * If destination LLE does not exists or lle state modification
 2235  * is required, call "slow" version.
 2236  *
 2237  * Return values:
 2238  * - 0 on success (address copied to buffer).
 2239  * - EWOULDBLOCK (no local error, but address is still unresolved)
 2240  * - other errors (alloc failure, etc)
 2241  */
 2242 int
 2243 nd6_resolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
 2244     const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
 2245     struct llentry **plle)
 2246 {
 2247         struct llentry *ln = NULL;
 2248         const struct sockaddr_in6 *dst6;
 2249 
 2250         if (pflags != NULL)
 2251                 *pflags = 0;
 2252 
 2253         dst6 = (const struct sockaddr_in6 *)sa_dst;
 2254 
 2255         /* discard the packet if IPv6 operation is disabled on the interface */
 2256         if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
 2257                 m_freem(m);
 2258                 return (ENETDOWN); /* better error? */
 2259         }
 2260 
 2261         if (m != NULL && m->m_flags & M_MCAST) {
 2262                 switch (ifp->if_type) {
 2263                 case IFT_ETHER:
 2264                 case IFT_L2VLAN:
 2265                 case IFT_BRIDGE:
 2266                         ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
 2267                                                  desten);
 2268                         return (0);
 2269                 default:
 2270                         m_freem(m);
 2271                         return (EAFNOSUPPORT);
 2272                 }
 2273         }
 2274 
 2275         IF_AFDATA_RLOCK(ifp);
 2276         ln = nd6_lookup(&dst6->sin6_addr, plle ? LLE_EXCLUSIVE : LLE_UNLOCKED,
 2277             ifp);
 2278         if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
 2279                 /* Entry found, let's copy lle info */
 2280                 bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
 2281                 if (pflags != NULL)
 2282                         *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
 2283                 /* Check if we have feedback request from nd6 timer */
 2284                 if (ln->r_skip_req != 0) {
 2285                         LLE_REQ_LOCK(ln);
 2286                         ln->r_skip_req = 0; /* Notify that entry was used */
 2287                         ln->lle_hittime = time_uptime;
 2288                         LLE_REQ_UNLOCK(ln);
 2289                 }
 2290                 if (plle) {
 2291                         LLE_ADDREF(ln);
 2292                         *plle = ln;
 2293                         LLE_WUNLOCK(ln);
 2294                 }
 2295                 IF_AFDATA_RUNLOCK(ifp);
 2296                 return (0);
 2297         } else if (plle && ln)
 2298                 LLE_WUNLOCK(ln);
 2299         IF_AFDATA_RUNLOCK(ifp);
 2300 
 2301         return (nd6_resolve_slow(ifp, 0, m, dst6, desten, pflags, plle));
 2302 }
 2303 
 2304 
 2305 /*
 2306  * Do L2 address resolution for @sa_dst address. Stores found
 2307  * address in @desten buffer. Copy of lle ln_flags can be also
 2308  * saved in @pflags if @pflags is non-NULL.
 2309  *
 2310  * Heavy version.
 2311  * Function assume that destination LLE does not exist,
 2312  * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
 2313  *
 2314  * Set noinline to be dtrace-friendly
 2315  */
 2316 static __noinline int
 2317 nd6_resolve_slow(struct ifnet *ifp, int flags, struct mbuf *m,
 2318     const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
 2319     struct llentry **plle)
 2320 {
 2321         struct llentry *lle = NULL, *lle_tmp;
 2322         struct in6_addr *psrc, src;
 2323         int send_ns, ll_len;
 2324         char *lladdr;
 2325 
 2326         /*
 2327          * Address resolution or Neighbor Unreachability Detection
 2328          * for the next hop.
 2329          * At this point, the destination of the packet must be a unicast
 2330          * or an anycast address(i.e. not a multicast).
 2331          */
 2332         if (lle == NULL) {
 2333                 IF_AFDATA_RLOCK(ifp);
 2334                 lle = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
 2335                 IF_AFDATA_RUNLOCK(ifp);
 2336                 if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp))  {
 2337                         /*
 2338                          * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
 2339                          * the condition below is not very efficient.  But we believe
 2340                          * it is tolerable, because this should be a rare case.
 2341                          */
 2342                         lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
 2343                         if (lle == NULL) {
 2344                                 char ip6buf[INET6_ADDRSTRLEN];
 2345                                 log(LOG_DEBUG,
 2346                                     "nd6_output: can't allocate llinfo for %s "
 2347                                     "(ln=%p)\n",
 2348                                     ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
 2349                                 m_freem(m);
 2350                                 return (ENOBUFS);
 2351                         }
 2352 
 2353                         IF_AFDATA_WLOCK(ifp);
 2354                         LLE_WLOCK(lle);
 2355                         /* Prefer any existing entry over newly-created one */
 2356                         lle_tmp = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
 2357                         if (lle_tmp == NULL)
 2358                                 lltable_link_entry(LLTABLE6(ifp), lle);
 2359                         IF_AFDATA_WUNLOCK(ifp);
 2360                         if (lle_tmp != NULL) {
 2361                                 lltable_free_entry(LLTABLE6(ifp), lle);
 2362                                 lle = lle_tmp;
 2363                                 lle_tmp = NULL;
 2364                         }
 2365                 }
 2366         } 
 2367         if (lle == NULL) {
 2368                 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
 2369                         m_freem(m);
 2370                         return (ENOBUFS);
 2371                 }
 2372 
 2373                 if (m != NULL)
 2374                         m_freem(m);
 2375                 return (ENOBUFS);
 2376         }
 2377 
 2378         LLE_WLOCK_ASSERT(lle);
 2379 
 2380         /*
 2381          * The first time we send a packet to a neighbor whose entry is
 2382          * STALE, we have to change the state to DELAY and a sets a timer to
 2383          * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
 2384          * neighbor unreachability detection on expiration.
 2385          * (RFC 2461 7.3.3)
 2386          */
 2387         if (lle->ln_state == ND6_LLINFO_STALE)
 2388                 nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
 2389 
 2390         /*
 2391          * If the neighbor cache entry has a state other than INCOMPLETE
 2392          * (i.e. its link-layer address is already resolved), just
 2393          * send the packet.
 2394          */
 2395         if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
 2396                 if (flags & LLE_ADDRONLY) {
 2397                         lladdr = lle->ll_addr;
 2398                         ll_len = ifp->if_addrlen;
 2399                 } else {
 2400                         lladdr = lle->r_linkdata;
 2401                         ll_len = lle->r_hdrlen;
 2402                 }
 2403                 bcopy(lladdr, desten, ll_len);
 2404                 if (pflags != NULL)
 2405                         *pflags = lle->la_flags;
 2406                 if (plle) {
 2407                         LLE_ADDREF(lle);
 2408                         *plle = lle;
 2409                 }
 2410                 LLE_WUNLOCK(lle);
 2411                 return (0);
 2412         }
 2413 
 2414         /*
 2415          * There is a neighbor cache entry, but no ethernet address
 2416          * response yet.  Append this latest packet to the end of the
 2417          * packet queue in the mbuf.  When it exceeds nd6_maxqueuelen,
 2418          * the oldest packet in the queue will be removed.
 2419          */
 2420 
 2421         if (lle->la_hold != NULL) {
 2422                 struct mbuf *m_hold;
 2423                 int i;
 2424                 
 2425                 i = 0;
 2426                 for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){
 2427                         i++;
 2428                         if (m_hold->m_nextpkt == NULL) {
 2429                                 m_hold->m_nextpkt = m;
 2430                                 break;
 2431                         }
 2432                 }
 2433                 while (i >= V_nd6_maxqueuelen) {
 2434                         m_hold = lle->la_hold;
 2435                         lle->la_hold = lle->la_hold->m_nextpkt;
 2436                         m_freem(m_hold);
 2437                         i--;
 2438                 }
 2439         } else {
 2440                 lle->la_hold = m;
 2441         }
 2442 
 2443         /*
 2444          * If there has been no NS for the neighbor after entering the
 2445          * INCOMPLETE state, send the first solicitation.
 2446          * Note that for newly-created lle la_asked will be 0,
 2447          * so we will transition from ND6_LLINFO_NOSTATE to
 2448          * ND6_LLINFO_INCOMPLETE state here.
 2449          */
 2450         psrc = NULL;
 2451         send_ns = 0;
 2452         if (lle->la_asked == 0) {
 2453                 lle->la_asked++;
 2454                 send_ns = 1;
 2455                 psrc = nd6_llinfo_get_holdsrc(lle, &src);
 2456 
 2457                 nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
 2458         }
 2459         LLE_WUNLOCK(lle);
 2460         if (send_ns != 0)
 2461                 nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
 2462 
 2463         return (EWOULDBLOCK);
 2464 }
 2465 
 2466 /*
 2467  * Do L2 address resolution for @sa_dst address. Stores found
 2468  * address in @desten buffer. Copy of lle ln_flags can be also
 2469  * saved in @pflags if @pflags is non-NULL.
 2470  *
 2471  * Return values:
 2472  * - 0 on success (address copied to buffer).
 2473  * - EWOULDBLOCK (no local error, but address is still unresolved)
 2474  * - other errors (alloc failure, etc)
 2475  */
 2476 int
 2477 nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
 2478     char *desten, uint32_t *pflags)
 2479 {
 2480         int error;
 2481 
 2482         flags |= LLE_ADDRONLY;
 2483         error = nd6_resolve_slow(ifp, flags, NULL,
 2484             (const struct sockaddr_in6 *)dst, desten, pflags, NULL);
 2485         return (error);
 2486 }
 2487 
 2488 int
 2489 nd6_flush_holdchain(struct ifnet *ifp, struct mbuf *chain,
 2490     struct sockaddr_in6 *dst)
 2491 {
 2492         struct mbuf *m, *m_head;
 2493         int error = 0;
 2494 
 2495         m_head = chain;
 2496 
 2497         while (m_head) {
 2498                 m = m_head;
 2499                 m_head = m_head->m_nextpkt;
 2500                 error = nd6_output_ifp(ifp, ifp, m, dst, NULL);
 2501         }
 2502 
 2503         /*
 2504          * XXX
 2505          * note that intermediate errors are blindly ignored
 2506          */
 2507         return (error);
 2508 }
 2509 
 2510 static int
 2511 nd6_need_cache(struct ifnet *ifp)
 2512 {
 2513         /*
 2514          * XXX: we currently do not make neighbor cache on any interface
 2515          * other than Ethernet and GIF.
 2516          *
 2517          * RFC2893 says:
 2518          * - unidirectional tunnels needs no ND
 2519          */
 2520         switch (ifp->if_type) {
 2521         case IFT_ETHER:
 2522         case IFT_IEEE1394:
 2523         case IFT_L2VLAN:
 2524         case IFT_INFINIBAND:
 2525         case IFT_BRIDGE:
 2526         case IFT_PROPVIRTUAL:
 2527                 return (1);
 2528         default:
 2529                 return (0);
 2530         }
 2531 }
 2532 
 2533 /*
 2534  * Add pernament ND6 link-layer record for given
 2535  * interface address.
 2536  *
 2537  * Very similar to IPv4 arp_ifinit(), but:
 2538  * 1) IPv6 DAD is performed in different place
 2539  * 2) It is called by IPv6 protocol stack in contrast to
 2540  * arp_ifinit() which is typically called in SIOCSIFADDR
 2541  * driver ioctl handler.
 2542  *
 2543  */
 2544 int
 2545 nd6_add_ifa_lle(struct in6_ifaddr *ia)
 2546 {
 2547         struct ifnet *ifp;
 2548         struct llentry *ln, *ln_tmp;
 2549         struct sockaddr *dst;
 2550 
 2551         ifp = ia->ia_ifa.ifa_ifp;
 2552         if (nd6_need_cache(ifp) == 0)
 2553                 return (0);
 2554 
 2555         ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
 2556         dst = (struct sockaddr *)&ia->ia_addr;
 2557         ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
 2558         if (ln == NULL)
 2559                 return (ENOBUFS);
 2560 
 2561         IF_AFDATA_WLOCK(ifp);
 2562         LLE_WLOCK(ln);
 2563         /* Unlink any entry if exists */
 2564         ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
 2565         if (ln_tmp != NULL)
 2566                 lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
 2567         lltable_link_entry(LLTABLE6(ifp), ln);
 2568         IF_AFDATA_WUNLOCK(ifp);
 2569 
 2570         if (ln_tmp != NULL)
 2571                 EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
 2572         EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
 2573 
 2574         LLE_WUNLOCK(ln);
 2575         if (ln_tmp != NULL)
 2576                 llentry_free(ln_tmp);
 2577 
 2578         return (0);
 2579 }
 2580 
 2581 /*
 2582  * Removes either all lle entries for given @ia, or lle
 2583  * corresponding to @ia address.
 2584  */
 2585 void
 2586 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
 2587 {
 2588         struct sockaddr_in6 mask, addr;
 2589         struct sockaddr *saddr, *smask;
 2590         struct ifnet *ifp;
 2591 
 2592         ifp = ia->ia_ifa.ifa_ifp;
 2593         memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
 2594         memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
 2595         saddr = (struct sockaddr *)&addr;
 2596         smask = (struct sockaddr *)&mask;
 2597 
 2598         if (all != 0)
 2599                 lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
 2600         else
 2601                 lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
 2602 }
 2603 
 2604 static void 
 2605 clear_llinfo_pqueue(struct llentry *ln)
 2606 {
 2607         struct mbuf *m_hold, *m_hold_next;
 2608 
 2609         for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
 2610                 m_hold_next = m_hold->m_nextpkt;
 2611                 m_freem(m_hold);
 2612         }
 2613 
 2614         ln->la_hold = NULL;
 2615 }
 2616 
 2617 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
 2618 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
 2619 
 2620 SYSCTL_DECL(_net_inet6_icmp6);
 2621 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
 2622         CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
 2623         NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
 2624         "NDP default router list");
 2625 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
 2626         CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
 2627         NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
 2628         "NDP prefix list");
 2629 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
 2630         CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
 2631 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
 2632         CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
 2633 
 2634 static int
 2635 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
 2636 {
 2637         struct in6_defrouter d;
 2638         struct nd_defrouter *dr;
 2639         int error;
 2640 
 2641         if (req->newptr != NULL)
 2642                 return (EPERM);
 2643 
 2644         error = sysctl_wire_old_buffer(req, 0);
 2645         if (error != 0)
 2646                 return (error);
 2647 
 2648         bzero(&d, sizeof(d));
 2649         d.rtaddr.sin6_family = AF_INET6;
 2650         d.rtaddr.sin6_len = sizeof(d.rtaddr);
 2651 
 2652         ND6_RLOCK();
 2653         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
 2654                 d.rtaddr.sin6_addr = dr->rtaddr;
 2655                 error = sa6_recoverscope(&d.rtaddr);
 2656                 if (error != 0)
 2657                         break;
 2658                 d.flags = dr->raflags;
 2659                 d.rtlifetime = dr->rtlifetime;
 2660                 d.expire = dr->expire + (time_second - time_uptime);
 2661                 d.if_index = dr->ifp->if_index;
 2662                 error = SYSCTL_OUT(req, &d, sizeof(d));
 2663                 if (error != 0)
 2664                         break;
 2665         }
 2666         ND6_RUNLOCK();
 2667         return (error);
 2668 }
 2669 
 2670 static int
 2671 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
 2672 {
 2673         struct in6_prefix p;
 2674         struct sockaddr_in6 s6;
 2675         struct nd_prefix *pr;
 2676         struct nd_pfxrouter *pfr;
 2677         time_t maxexpire;
 2678         int error;
 2679         char ip6buf[INET6_ADDRSTRLEN];
 2680 
 2681         if (req->newptr)
 2682                 return (EPERM);
 2683 
 2684         error = sysctl_wire_old_buffer(req, 0);
 2685         if (error != 0)
 2686                 return (error);
 2687 
 2688         bzero(&p, sizeof(p));
 2689         p.origin = PR_ORIG_RA;
 2690         bzero(&s6, sizeof(s6));
 2691         s6.sin6_family = AF_INET6;
 2692         s6.sin6_len = sizeof(s6);
 2693 
 2694         ND6_RLOCK();
 2695         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 2696                 p.prefix = pr->ndpr_prefix;
 2697                 if (sa6_recoverscope(&p.prefix)) {
 2698                         log(LOG_ERR, "scope error in prefix list (%s)\n",
 2699                             ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
 2700                         /* XXX: press on... */
 2701                 }
 2702                 p.raflags = pr->ndpr_raf;
 2703                 p.prefixlen = pr->ndpr_plen;
 2704                 p.vltime = pr->ndpr_vltime;
 2705                 p.pltime = pr->ndpr_pltime;
 2706                 p.if_index = pr->ndpr_ifp->if_index;
 2707                 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
 2708                         p.expire = 0;
 2709                 else {
 2710                         /* XXX: we assume time_t is signed. */
 2711                         maxexpire = (-1) &
 2712                             ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
 2713                         if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
 2714                                 p.expire = pr->ndpr_lastupdate +
 2715                                     pr->ndpr_vltime +
 2716                                     (time_second - time_uptime);
 2717                         else
 2718                                 p.expire = maxexpire;
 2719                 }
 2720                 p.refcnt = pr->ndpr_addrcnt;
 2721                 p.flags = pr->ndpr_stateflags;
 2722                 p.advrtrs = 0;
 2723                 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
 2724                         p.advrtrs++;
 2725                 error = SYSCTL_OUT(req, &p, sizeof(p));
 2726                 if (error != 0)
 2727                         break;
 2728                 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
 2729                         s6.sin6_addr = pfr->router->rtaddr;
 2730                         if (sa6_recoverscope(&s6))
 2731                                 log(LOG_ERR,
 2732                                     "scope error in prefix list (%s)\n",
 2733                                     ip6_sprintf(ip6buf, &pfr->router->rtaddr));
 2734                         error = SYSCTL_OUT(req, &s6, sizeof(s6));
 2735                         if (error != 0)
 2736                                 goto out;
 2737                 }
 2738         }
 2739 out:
 2740         ND6_RUNLOCK();
 2741         return (error);
 2742 }

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