The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/nd6.c

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    1 /*-
    2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 3. Neither the name of the project nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      $KAME: nd6.c,v 1.144 2001/05/24 07:44:00 itojun Exp $
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD: releng/11.0/sys/netinet6/nd6.c 303698 2016-08-03 06:32:44Z karels $");
   34 
   35 #include "opt_inet.h"
   36 #include "opt_inet6.h"
   37 
   38 #include <sys/param.h>
   39 #include <sys/systm.h>
   40 #include <sys/callout.h>
   41 #include <sys/malloc.h>
   42 #include <sys/mbuf.h>
   43 #include <sys/socket.h>
   44 #include <sys/sockio.h>
   45 #include <sys/time.h>
   46 #include <sys/kernel.h>
   47 #include <sys/protosw.h>
   48 #include <sys/errno.h>
   49 #include <sys/syslog.h>
   50 #include <sys/lock.h>
   51 #include <sys/rwlock.h>
   52 #include <sys/queue.h>
   53 #include <sys/sdt.h>
   54 #include <sys/sysctl.h>
   55 
   56 #include <net/if.h>
   57 #include <net/if_var.h>
   58 #include <net/if_arc.h>
   59 #include <net/if_dl.h>
   60 #include <net/if_types.h>
   61 #include <net/iso88025.h>
   62 #include <net/fddi.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 static VNET_DEFINE(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 static VNET_DEFINE(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 
  122 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
  123 #define V_nd6_recalc_reachtm_interval   VNET(nd6_recalc_reachtm_interval)
  124 
  125 int     (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
  126 
  127 static int nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
  128         struct ifnet *);
  129 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
  130 static void nd6_slowtimo(void *);
  131 static int regen_tmpaddr(struct in6_ifaddr *);
  132 static void nd6_free(struct llentry **, int);
  133 static void nd6_free_redirect(const struct llentry *);
  134 static void nd6_llinfo_timer(void *);
  135 static void nd6_llinfo_settimer_locked(struct llentry *, long);
  136 static void clear_llinfo_pqueue(struct llentry *);
  137 static void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
  138 static int nd6_resolve_slow(struct ifnet *, int, struct mbuf *,
  139     const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
  140 static int nd6_need_cache(struct ifnet *);
  141  
  142 
  143 static VNET_DEFINE(struct callout, nd6_slowtimo_ch);
  144 #define V_nd6_slowtimo_ch               VNET(nd6_slowtimo_ch)
  145 
  146 VNET_DEFINE(struct callout, nd6_timer_ch);
  147 #define V_nd6_timer_ch                  VNET(nd6_timer_ch)
  148 
  149 static void
  150 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
  151 {
  152         struct rt_addrinfo rtinfo;
  153         struct sockaddr_in6 dst;
  154         struct sockaddr_dl gw;
  155         struct ifnet *ifp;
  156         int type;
  157 
  158         LLE_WLOCK_ASSERT(lle);
  159 
  160         if (lltable_get_af(lle->lle_tbl) != AF_INET6)
  161                 return;
  162 
  163         switch (evt) {
  164         case LLENTRY_RESOLVED:
  165                 type = RTM_ADD;
  166                 KASSERT(lle->la_flags & LLE_VALID,
  167                     ("%s: %p resolved but not valid?", __func__, lle));
  168                 break;
  169         case LLENTRY_EXPIRED:
  170                 type = RTM_DELETE;
  171                 break;
  172         default:
  173                 return;
  174         }
  175 
  176         ifp = lltable_get_ifp(lle->lle_tbl);
  177 
  178         bzero(&dst, sizeof(dst));
  179         bzero(&gw, sizeof(gw));
  180         bzero(&rtinfo, sizeof(rtinfo));
  181         lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
  182         dst.sin6_scope_id = in6_getscopezone(ifp,
  183             in6_addrscope(&dst.sin6_addr));
  184         gw.sdl_len = sizeof(struct sockaddr_dl);
  185         gw.sdl_family = AF_LINK;
  186         gw.sdl_alen = ifp->if_addrlen;
  187         gw.sdl_index = ifp->if_index;
  188         gw.sdl_type = ifp->if_type;
  189         if (evt == LLENTRY_RESOLVED)
  190                 bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
  191         rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
  192         rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
  193         rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
  194         rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
  195             type == RTM_ADD ? RTF_UP: 0), 0, RT_DEFAULT_FIB);
  196 }
  197 
  198 /*
  199  * A handler for interface link layer address change event.
  200  */
  201 static void
  202 nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
  203 {
  204 
  205         lltable_update_ifaddr(LLTABLE6(ifp));
  206 }
  207 
  208 void
  209 nd6_init(void)
  210 {
  211 
  212         rw_init(&V_nd6_lock, "nd6");
  213 
  214         LIST_INIT(&V_nd_prefix);
  215 
  216         /* initialization of the default router list */
  217         TAILQ_INIT(&V_nd_defrouter);
  218 
  219         /* Start timers. */
  220         callout_init(&V_nd6_slowtimo_ch, 0);
  221         callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
  222             nd6_slowtimo, curvnet);
  223 
  224         callout_init(&V_nd6_timer_ch, 0);
  225         callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
  226 
  227         nd6_dad_init();
  228         if (IS_DEFAULT_VNET(curvnet)) {
  229                 lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
  230                     NULL, EVENTHANDLER_PRI_ANY);
  231                 iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
  232                     nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
  233         }
  234 }
  235 
  236 #ifdef VIMAGE
  237 void
  238 nd6_destroy()
  239 {
  240 
  241         callout_drain(&V_nd6_slowtimo_ch);
  242         callout_drain(&V_nd6_timer_ch);
  243         if (IS_DEFAULT_VNET(curvnet)) {
  244                 EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
  245                 EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
  246         }
  247         rw_destroy(&V_nd6_lock);
  248 }
  249 #endif
  250 
  251 struct nd_ifinfo *
  252 nd6_ifattach(struct ifnet *ifp)
  253 {
  254         struct nd_ifinfo *nd;
  255 
  256         nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
  257         nd->initialized = 1;
  258 
  259         nd->chlim = IPV6_DEFHLIM;
  260         nd->basereachable = REACHABLE_TIME;
  261         nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
  262         nd->retrans = RETRANS_TIMER;
  263 
  264         nd->flags = ND6_IFF_PERFORMNUD;
  265 
  266         /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
  267          * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
  268          * default regardless of the V_ip6_auto_linklocal configuration to
  269          * give a reasonable default behavior.
  270          */
  271         if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
  272             (ifp->if_flags & IFF_LOOPBACK))
  273                 nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
  274         /*
  275          * A loopback interface does not need to accept RTADV.
  276          * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
  277          * default regardless of the V_ip6_accept_rtadv configuration to
  278          * prevent the interface from accepting RA messages arrived
  279          * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
  280          */
  281         if (V_ip6_accept_rtadv &&
  282             !(ifp->if_flags & IFF_LOOPBACK) &&
  283             (ifp->if_type != IFT_BRIDGE))
  284                         nd->flags |= ND6_IFF_ACCEPT_RTADV;
  285         if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
  286                 nd->flags |= ND6_IFF_NO_RADR;
  287 
  288         /* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
  289         nd6_setmtu0(ifp, nd);
  290 
  291         return nd;
  292 }
  293 
  294 void
  295 nd6_ifdetach(struct ifnet *ifp, struct nd_ifinfo *nd)
  296 {
  297         struct ifaddr *ifa, *next;
  298 
  299         IF_ADDR_RLOCK(ifp);
  300         TAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
  301                 if (ifa->ifa_addr->sa_family != AF_INET6)
  302                         continue;
  303 
  304                 /* stop DAD processing */
  305                 nd6_dad_stop(ifa);
  306         }
  307         IF_ADDR_RUNLOCK(ifp);
  308 
  309         free(nd, M_IP6NDP);
  310 }
  311 
  312 /*
  313  * Reset ND level link MTU. This function is called when the physical MTU
  314  * changes, which means we might have to adjust the ND level MTU.
  315  */
  316 void
  317 nd6_setmtu(struct ifnet *ifp)
  318 {
  319         if (ifp->if_afdata[AF_INET6] == NULL)
  320                 return;
  321 
  322         nd6_setmtu0(ifp, ND_IFINFO(ifp));
  323 }
  324 
  325 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
  326 void
  327 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
  328 {
  329         u_int32_t omaxmtu;
  330 
  331         omaxmtu = ndi->maxmtu;
  332 
  333         switch (ifp->if_type) {
  334         case IFT_ARCNET:
  335                 ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
  336                 break;
  337         case IFT_FDDI:
  338                 ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu); /* RFC2467 */
  339                 break;
  340         case IFT_ISO88025:
  341                  ndi->maxmtu = MIN(ISO88025_MAX_MTU, ifp->if_mtu);
  342                  break;
  343         default:
  344                 ndi->maxmtu = ifp->if_mtu;
  345                 break;
  346         }
  347 
  348         /*
  349          * Decreasing the interface MTU under IPV6 minimum MTU may cause
  350          * undesirable situation.  We thus notify the operator of the change
  351          * explicitly.  The check for omaxmtu is necessary to restrict the
  352          * log to the case of changing the MTU, not initializing it.
  353          */
  354         if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
  355                 log(LOG_NOTICE, "nd6_setmtu0: "
  356                     "new link MTU on %s (%lu) is too small for IPv6\n",
  357                     if_name(ifp), (unsigned long)ndi->maxmtu);
  358         }
  359 
  360         if (ndi->maxmtu > V_in6_maxmtu)
  361                 in6_setmaxmtu(); /* check all interfaces just in case */
  362 
  363 }
  364 
  365 void
  366 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
  367 {
  368 
  369         bzero(ndopts, sizeof(*ndopts));
  370         ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
  371         ndopts->nd_opts_last
  372                 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
  373 
  374         if (icmp6len == 0) {
  375                 ndopts->nd_opts_done = 1;
  376                 ndopts->nd_opts_search = NULL;
  377         }
  378 }
  379 
  380 /*
  381  * Take one ND option.
  382  */
  383 struct nd_opt_hdr *
  384 nd6_option(union nd_opts *ndopts)
  385 {
  386         struct nd_opt_hdr *nd_opt;
  387         int olen;
  388 
  389         KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
  390         KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
  391             __func__));
  392         if (ndopts->nd_opts_search == NULL)
  393                 return NULL;
  394         if (ndopts->nd_opts_done)
  395                 return NULL;
  396 
  397         nd_opt = ndopts->nd_opts_search;
  398 
  399         /* make sure nd_opt_len is inside the buffer */
  400         if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
  401                 bzero(ndopts, sizeof(*ndopts));
  402                 return NULL;
  403         }
  404 
  405         olen = nd_opt->nd_opt_len << 3;
  406         if (olen == 0) {
  407                 /*
  408                  * Message validation requires that all included
  409                  * options have a length that is greater than zero.
  410                  */
  411                 bzero(ndopts, sizeof(*ndopts));
  412                 return NULL;
  413         }
  414 
  415         ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
  416         if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
  417                 /* option overruns the end of buffer, invalid */
  418                 bzero(ndopts, sizeof(*ndopts));
  419                 return NULL;
  420         } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
  421                 /* reached the end of options chain */
  422                 ndopts->nd_opts_done = 1;
  423                 ndopts->nd_opts_search = NULL;
  424         }
  425         return nd_opt;
  426 }
  427 
  428 /*
  429  * Parse multiple ND options.
  430  * This function is much easier to use, for ND routines that do not need
  431  * multiple options of the same type.
  432  */
  433 int
  434 nd6_options(union nd_opts *ndopts)
  435 {
  436         struct nd_opt_hdr *nd_opt;
  437         int i = 0;
  438 
  439         KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
  440         KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
  441             __func__));
  442         if (ndopts->nd_opts_search == NULL)
  443                 return 0;
  444 
  445         while (1) {
  446                 nd_opt = nd6_option(ndopts);
  447                 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
  448                         /*
  449                          * Message validation requires that all included
  450                          * options have a length that is greater than zero.
  451                          */
  452                         ICMP6STAT_INC(icp6s_nd_badopt);
  453                         bzero(ndopts, sizeof(*ndopts));
  454                         return -1;
  455                 }
  456 
  457                 if (nd_opt == NULL)
  458                         goto skip1;
  459 
  460                 switch (nd_opt->nd_opt_type) {
  461                 case ND_OPT_SOURCE_LINKADDR:
  462                 case ND_OPT_TARGET_LINKADDR:
  463                 case ND_OPT_MTU:
  464                 case ND_OPT_REDIRECTED_HEADER:
  465                 case ND_OPT_NONCE:
  466                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
  467                                 nd6log((LOG_INFO,
  468                                     "duplicated ND6 option found (type=%d)\n",
  469                                     nd_opt->nd_opt_type));
  470                                 /* XXX bark? */
  471                         } else {
  472                                 ndopts->nd_opt_array[nd_opt->nd_opt_type]
  473                                         = nd_opt;
  474                         }
  475                         break;
  476                 case ND_OPT_PREFIX_INFORMATION:
  477                         if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
  478                                 ndopts->nd_opt_array[nd_opt->nd_opt_type]
  479                                         = nd_opt;
  480                         }
  481                         ndopts->nd_opts_pi_end =
  482                                 (struct nd_opt_prefix_info *)nd_opt;
  483                         break;
  484                 /* What about ND_OPT_ROUTE_INFO? RFC 4191 */
  485                 case ND_OPT_RDNSS:      /* RFC 6106 */
  486                 case ND_OPT_DNSSL:      /* RFC 6106 */
  487                         /*
  488                          * Silently ignore options we know and do not care about
  489                          * in the kernel.
  490                          */
  491                         break;
  492                 default:
  493                         /*
  494                          * Unknown options must be silently ignored,
  495                          * to accommodate future extension to the protocol.
  496                          */
  497                         nd6log((LOG_DEBUG,
  498                             "nd6_options: unsupported option %d - "
  499                             "option ignored\n", nd_opt->nd_opt_type));
  500                 }
  501 
  502 skip1:
  503                 i++;
  504                 if (i > V_nd6_maxndopt) {
  505                         ICMP6STAT_INC(icp6s_nd_toomanyopt);
  506                         nd6log((LOG_INFO, "too many loop in nd opt\n"));
  507                         break;
  508                 }
  509 
  510                 if (ndopts->nd_opts_done)
  511                         break;
  512         }
  513 
  514         return 0;
  515 }
  516 
  517 /*
  518  * ND6 timer routine to handle ND6 entries
  519  */
  520 static void
  521 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
  522 {
  523         int canceled;
  524 
  525         LLE_WLOCK_ASSERT(ln);
  526 
  527         if (tick < 0) {
  528                 ln->la_expire = 0;
  529                 ln->ln_ntick = 0;
  530                 canceled = callout_stop(&ln->lle_timer);
  531         } else {
  532                 ln->la_expire = time_uptime + tick / hz;
  533                 LLE_ADDREF(ln);
  534                 if (tick > INT_MAX) {
  535                         ln->ln_ntick = tick - INT_MAX;
  536                         canceled = callout_reset(&ln->lle_timer, INT_MAX,
  537                             nd6_llinfo_timer, ln);
  538                 } else {
  539                         ln->ln_ntick = 0;
  540                         canceled = callout_reset(&ln->lle_timer, tick,
  541                             nd6_llinfo_timer, ln);
  542                 }
  543         }
  544         if (canceled > 0)
  545                 LLE_REMREF(ln);
  546 }
  547 
  548 /*
  549  * Gets source address of the first packet in hold queue
  550  * and stores it in @src.
  551  * Returns pointer to @src (if hold queue is not empty) or NULL.
  552  *
  553  * Set noinline to be dtrace-friendly
  554  */
  555 static __noinline struct in6_addr *
  556 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
  557 {
  558         struct ip6_hdr hdr;
  559         struct mbuf *m;
  560 
  561         if (ln->la_hold == NULL)
  562                 return (NULL);
  563 
  564         /*
  565          * assume every packet in la_hold has the same IP header
  566          */
  567         m = ln->la_hold;
  568         if (sizeof(hdr) > m->m_len)
  569                 return (NULL);
  570 
  571         m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
  572         *src = hdr.ip6_src;
  573 
  574         return (src);
  575 }
  576 
  577 /*
  578  * Checks if we need to switch from STALE state.
  579  *
  580  * RFC 4861 requires switching from STALE to DELAY state
  581  * on first packet matching entry, waiting V_nd6_delay and
  582  * transition to PROBE state (if upper layer confirmation was
  583  * not received).
  584  *
  585  * This code performs a bit differently:
  586  * On packet hit we don't change state (but desired state
  587  * can be guessed by control plane). However, after V_nd6_delay
  588  * seconds code will transition to PROBE state (so DELAY state
  589  * is kinda skipped in most situations).
  590  *
  591  * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
  592  * we perform the following upon entering STALE state:
  593  *
  594  * 1) Arm timer to run each V_nd6_delay seconds to make sure that
  595  * if packet was transmitted at the start of given interval, we
  596  * would be able to switch to PROBE state in V_nd6_delay seconds
  597  * as user expects.
  598  *
  599  * 2) Reschedule timer until original V_nd6_gctimer expires keeping
  600  * lle in STALE state (remaining timer value stored in lle_remtime).
  601  *
  602  * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
  603  * seconds ago.
  604  *
  605  * Returns non-zero value if the entry is still STALE (storing
  606  * the next timer interval in @pdelay).
  607  *
  608  * Returns zero value if original timer expired or we need to switch to
  609  * PROBE (store that in @do_switch variable).
  610  */
  611 static int
  612 nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
  613 {
  614         int nd_delay, nd_gctimer, r_skip_req;
  615         time_t lle_hittime;
  616         long delay;
  617 
  618         *do_switch = 0;
  619         nd_gctimer = V_nd6_gctimer;
  620         nd_delay = V_nd6_delay;
  621 
  622         LLE_REQ_LOCK(lle);
  623         r_skip_req = lle->r_skip_req;
  624         lle_hittime = lle->lle_hittime;
  625         LLE_REQ_UNLOCK(lle);
  626 
  627         if (r_skip_req > 0) {
  628 
  629                 /*
  630                  * Nonzero r_skip_req value was set upon entering
  631                  * STALE state. Since value was not changed, no
  632                  * packets were passed using this lle. Ask for
  633                  * timer reschedule and keep STALE state.
  634                  */
  635                 delay = (long)(MIN(nd_gctimer, nd_delay));
  636                 delay *= hz;
  637                 if (lle->lle_remtime > delay)
  638                         lle->lle_remtime -= delay;
  639                 else {
  640                         delay = lle->lle_remtime;
  641                         lle->lle_remtime = 0;
  642                 }
  643 
  644                 if (delay == 0) {
  645 
  646                         /*
  647                          * The original ng6_gctime timeout ended,
  648                          * no more rescheduling.
  649                          */
  650                         return (0);
  651                 }
  652 
  653                 *pdelay = delay;
  654                 return (1);
  655         }
  656 
  657         /*
  658          * Packet received. Verify timestamp
  659          */
  660         delay = (long)(time_uptime - lle_hittime);
  661         if (delay < nd_delay) {
  662 
  663                 /*
  664                  * V_nd6_delay still not passed since the first
  665                  * hit in STALE state.
  666                  * Reshedule timer and return.
  667                  */
  668                 *pdelay = (long)(nd_delay - delay) * hz;
  669                 return (1);
  670         }
  671 
  672         /* Request switching to probe */
  673         *do_switch = 1;
  674         return (0);
  675 }
  676 
  677 
  678 /*
  679  * Switch @lle state to new state optionally arming timers.
  680  *
  681  * Set noinline to be dtrace-friendly
  682  */
  683 __noinline void
  684 nd6_llinfo_setstate(struct llentry *lle, int newstate)
  685 {
  686         struct ifnet *ifp;
  687         int nd_gctimer, nd_delay;
  688         long delay, remtime;
  689 
  690         delay = 0;
  691         remtime = 0;
  692 
  693         switch (newstate) {
  694         case ND6_LLINFO_INCOMPLETE:
  695                 ifp = lle->lle_tbl->llt_ifp;
  696                 delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000;
  697                 break;
  698         case ND6_LLINFO_REACHABLE:
  699                 if (!ND6_LLINFO_PERMANENT(lle)) {
  700                         ifp = lle->lle_tbl->llt_ifp;
  701                         delay = (long)ND_IFINFO(ifp)->reachable * hz;
  702                 }
  703                 break;
  704         case ND6_LLINFO_STALE:
  705 
  706                 /*
  707                  * Notify fast path that we want to know if any packet
  708                  * is transmitted by setting r_skip_req.
  709                  */
  710                 LLE_REQ_LOCK(lle);
  711                 lle->r_skip_req = 1;
  712                 LLE_REQ_UNLOCK(lle);
  713                 nd_delay = V_nd6_delay;
  714                 nd_gctimer = V_nd6_gctimer;
  715 
  716                 delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
  717                 remtime = (long)nd_gctimer * hz - delay;
  718                 break;
  719         case ND6_LLINFO_DELAY:
  720                 lle->la_asked = 0;
  721                 delay = (long)V_nd6_delay * hz;
  722                 break;
  723         }
  724 
  725         if (delay > 0)
  726                 nd6_llinfo_settimer_locked(lle, delay);
  727 
  728         lle->lle_remtime = remtime;
  729         lle->ln_state = newstate;
  730 }
  731 
  732 /*
  733  * Timer-dependent part of nd state machine.
  734  *
  735  * Set noinline to be dtrace-friendly
  736  */
  737 static __noinline void
  738 nd6_llinfo_timer(void *arg)
  739 {
  740         struct llentry *ln;
  741         struct in6_addr *dst, *pdst, *psrc, src;
  742         struct ifnet *ifp;
  743         struct nd_ifinfo *ndi;
  744         int do_switch, send_ns;
  745         long delay;
  746 
  747         KASSERT(arg != NULL, ("%s: arg NULL", __func__));
  748         ln = (struct llentry *)arg;
  749         ifp = lltable_get_ifp(ln->lle_tbl);
  750         CURVNET_SET(ifp->if_vnet);
  751 
  752         ND6_RLOCK();
  753         LLE_WLOCK(ln);
  754         if (callout_pending(&ln->lle_timer)) {
  755                 /*
  756                  * Here we are a bit odd here in the treatment of 
  757                  * active/pending. If the pending bit is set, it got
  758                  * rescheduled before I ran. The active
  759                  * bit we ignore, since if it was stopped
  760                  * in ll_tablefree() and was currently running
  761                  * it would have return 0 so the code would
  762                  * not have deleted it since the callout could
  763                  * not be stopped so we want to go through
  764                  * with the delete here now. If the callout
  765                  * was restarted, the pending bit will be back on and
  766                  * we just want to bail since the callout_reset would
  767                  * return 1 and our reference would have been removed
  768                  * by nd6_llinfo_settimer_locked above since canceled
  769                  * would have been 1.
  770                  */
  771                 LLE_WUNLOCK(ln);
  772                 ND6_RUNLOCK();
  773                 CURVNET_RESTORE();
  774                 return;
  775         }
  776         ndi = ND_IFINFO(ifp);
  777         send_ns = 0;
  778         dst = &ln->r_l3addr.addr6;
  779         pdst = dst;
  780 
  781         if (ln->ln_ntick > 0) {
  782                 if (ln->ln_ntick > INT_MAX) {
  783                         ln->ln_ntick -= INT_MAX;
  784                         nd6_llinfo_settimer_locked(ln, INT_MAX);
  785                 } else {
  786                         ln->ln_ntick = 0;
  787                         nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
  788                 }
  789                 goto done;
  790         }
  791 
  792         if (ln->la_flags & LLE_STATIC) {
  793                 goto done;
  794         }
  795 
  796         if (ln->la_flags & LLE_DELETED) {
  797                 nd6_free(&ln, 0);
  798                 goto done;
  799         }
  800 
  801         switch (ln->ln_state) {
  802         case ND6_LLINFO_INCOMPLETE:
  803                 if (ln->la_asked < V_nd6_mmaxtries) {
  804                         ln->la_asked++;
  805                         send_ns = 1;
  806                         /* Send NS to multicast address */
  807                         pdst = NULL;
  808                 } else {
  809                         struct mbuf *m = ln->la_hold;
  810                         if (m) {
  811                                 struct mbuf *m0;
  812 
  813                                 /*
  814                                  * assuming every packet in la_hold has the
  815                                  * same IP header.  Send error after unlock.
  816                                  */
  817                                 m0 = m->m_nextpkt;
  818                                 m->m_nextpkt = NULL;
  819                                 ln->la_hold = m0;
  820                                 clear_llinfo_pqueue(ln);
  821                         }
  822                         nd6_free(&ln, 0);
  823                         if (m != NULL)
  824                                 icmp6_error2(m, ICMP6_DST_UNREACH,
  825                                     ICMP6_DST_UNREACH_ADDR, 0, ifp);
  826                 }
  827                 break;
  828         case ND6_LLINFO_REACHABLE:
  829                 if (!ND6_LLINFO_PERMANENT(ln))
  830                         nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
  831                 break;
  832 
  833         case ND6_LLINFO_STALE:
  834                 if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
  835 
  836                         /*
  837                          * No packet has used this entry and GC timeout
  838                          * has not been passed. Reshedule timer and
  839                          * return.
  840                          */
  841                         nd6_llinfo_settimer_locked(ln, delay);
  842                         break;
  843                 }
  844 
  845                 if (do_switch == 0) {
  846 
  847                         /*
  848                          * GC timer has ended and entry hasn't been used.
  849                          * Run Garbage collector (RFC 4861, 5.3)
  850                          */
  851                         if (!ND6_LLINFO_PERMANENT(ln))
  852                                 nd6_free(&ln, 1);
  853                         break;
  854                 }
  855 
  856                 /* Entry has been used AND delay timer has ended. */
  857 
  858                 /* FALLTHROUGH */
  859 
  860         case ND6_LLINFO_DELAY:
  861                 if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
  862                         /* We need NUD */
  863                         ln->la_asked = 1;
  864                         nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
  865                         send_ns = 1;
  866                 } else
  867                         nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
  868                 break;
  869         case ND6_LLINFO_PROBE:
  870                 if (ln->la_asked < V_nd6_umaxtries) {
  871                         ln->la_asked++;
  872                         send_ns = 1;
  873                 } else {
  874                         nd6_free(&ln, 0);
  875                 }
  876                 break;
  877         default:
  878                 panic("%s: paths in a dark night can be confusing: %d",
  879                     __func__, ln->ln_state);
  880         }
  881 done:
  882         if (ln != NULL)
  883                 ND6_RUNLOCK();
  884         if (send_ns != 0) {
  885                 nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
  886                 psrc = nd6_llinfo_get_holdsrc(ln, &src);
  887                 LLE_FREE_LOCKED(ln);
  888                 ln = NULL;
  889                 nd6_ns_output(ifp, psrc, pdst, dst, NULL);
  890         }
  891 
  892         if (ln != NULL)
  893                 LLE_FREE_LOCKED(ln);
  894         CURVNET_RESTORE();
  895 }
  896 
  897 
  898 /*
  899  * ND6 timer routine to expire default route list and prefix list
  900  */
  901 void
  902 nd6_timer(void *arg)
  903 {
  904         CURVNET_SET((struct vnet *) arg);
  905         struct nd_drhead drq;
  906         struct nd_defrouter *dr, *ndr;
  907         struct nd_prefix *pr, *npr;
  908         struct in6_ifaddr *ia6, *nia6;
  909 
  910         TAILQ_INIT(&drq);
  911 
  912         /* expire default router list */
  913         ND6_WLOCK();
  914         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr)
  915                 if (dr->expire && dr->expire < time_uptime)
  916                         defrouter_unlink(dr, &drq);
  917         ND6_WUNLOCK();
  918 
  919         while ((dr = TAILQ_FIRST(&drq)) != NULL) {
  920                 TAILQ_REMOVE(&drq, dr, dr_entry);
  921                 defrouter_del(dr);
  922         }
  923 
  924         /*
  925          * expire interface addresses.
  926          * in the past the loop was inside prefix expiry processing.
  927          * However, from a stricter speci-confrmance standpoint, we should
  928          * rather separate address lifetimes and prefix lifetimes.
  929          *
  930          * XXXRW: in6_ifaddrhead locking.
  931          */
  932   addrloop:
  933         TAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
  934                 /* check address lifetime */
  935                 if (IFA6_IS_INVALID(ia6)) {
  936                         int regen = 0;
  937 
  938                         /*
  939                          * If the expiring address is temporary, try
  940                          * regenerating a new one.  This would be useful when
  941                          * we suspended a laptop PC, then turned it on after a
  942                          * period that could invalidate all temporary
  943                          * addresses.  Although we may have to restart the
  944                          * loop (see below), it must be after purging the
  945                          * address.  Otherwise, we'd see an infinite loop of
  946                          * regeneration.
  947                          */
  948                         if (V_ip6_use_tempaddr &&
  949                             (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
  950                                 if (regen_tmpaddr(ia6) == 0)
  951                                         regen = 1;
  952                         }
  953 
  954                         in6_purgeaddr(&ia6->ia_ifa);
  955 
  956                         if (regen)
  957                                 goto addrloop; /* XXX: see below */
  958                 } else if (IFA6_IS_DEPRECATED(ia6)) {
  959                         int oldflags = ia6->ia6_flags;
  960 
  961                         ia6->ia6_flags |= IN6_IFF_DEPRECATED;
  962 
  963                         /*
  964                          * If a temporary address has just become deprecated,
  965                          * regenerate a new one if possible.
  966                          */
  967                         if (V_ip6_use_tempaddr &&
  968                             (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
  969                             (oldflags & IN6_IFF_DEPRECATED) == 0) {
  970 
  971                                 if (regen_tmpaddr(ia6) == 0) {
  972                                         /*
  973                                          * A new temporary address is
  974                                          * generated.
  975                                          * XXX: this means the address chain
  976                                          * has changed while we are still in
  977                                          * the loop.  Although the change
  978                                          * would not cause disaster (because
  979                                          * it's not a deletion, but an
  980                                          * addition,) we'd rather restart the
  981                                          * loop just for safety.  Or does this
  982                                          * significantly reduce performance??
  983                                          */
  984                                         goto addrloop;
  985                                 }
  986                         }
  987                 } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
  988                         /*
  989                          * Schedule DAD for a tentative address.  This happens
  990                          * if the interface was down or not running
  991                          * when the address was configured.
  992                          */
  993                         int delay;
  994 
  995                         delay = arc4random() %
  996                             (MAX_RTR_SOLICITATION_DELAY * hz);
  997                         nd6_dad_start((struct ifaddr *)ia6, delay);
  998                 } else {
  999                         /*
 1000                          * Check status of the interface.  If it is down,
 1001                          * mark the address as tentative for future DAD.
 1002                          */
 1003                         if ((ia6->ia_ifp->if_flags & IFF_UP) == 0 ||
 1004                             (ia6->ia_ifp->if_drv_flags & IFF_DRV_RUNNING)
 1005                                 == 0 ||
 1006                             (ND_IFINFO(ia6->ia_ifp)->flags &
 1007                                 ND6_IFF_IFDISABLED) != 0) {
 1008                                 ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
 1009                                 ia6->ia6_flags |= IN6_IFF_TENTATIVE;
 1010                         }
 1011                         /*
 1012                          * A new RA might have made a deprecated address
 1013                          * preferred.
 1014                          */
 1015                         ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
 1016                 }
 1017         }
 1018 
 1019         /* expire prefix list */
 1020         LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
 1021                 /*
 1022                  * check prefix lifetime.
 1023                  * since pltime is just for autoconf, pltime processing for
 1024                  * prefix is not necessary.
 1025                  */
 1026                 if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
 1027                     time_uptime - pr->ndpr_lastupdate > pr->ndpr_vltime) {
 1028 
 1029                         /*
 1030                          * address expiration and prefix expiration are
 1031                          * separate.  NEVER perform in6_purgeaddr here.
 1032                          */
 1033                         prelist_remove(pr);
 1034                 }
 1035         }
 1036 
 1037         callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
 1038             nd6_timer, curvnet);
 1039 
 1040         CURVNET_RESTORE();
 1041 }
 1042 
 1043 /*
 1044  * ia6 - deprecated/invalidated temporary address
 1045  */
 1046 static int
 1047 regen_tmpaddr(struct in6_ifaddr *ia6)
 1048 {
 1049         struct ifaddr *ifa;
 1050         struct ifnet *ifp;
 1051         struct in6_ifaddr *public_ifa6 = NULL;
 1052 
 1053         ifp = ia6->ia_ifa.ifa_ifp;
 1054         IF_ADDR_RLOCK(ifp);
 1055         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1056                 struct in6_ifaddr *it6;
 1057 
 1058                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1059                         continue;
 1060 
 1061                 it6 = (struct in6_ifaddr *)ifa;
 1062 
 1063                 /* ignore no autoconf addresses. */
 1064                 if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1065                         continue;
 1066 
 1067                 /* ignore autoconf addresses with different prefixes. */
 1068                 if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
 1069                         continue;
 1070 
 1071                 /*
 1072                  * Now we are looking at an autoconf address with the same
 1073                  * prefix as ours.  If the address is temporary and is still
 1074                  * preferred, do not create another one.  It would be rare, but
 1075                  * could happen, for example, when we resume a laptop PC after
 1076                  * a long period.
 1077                  */
 1078                 if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
 1079                     !IFA6_IS_DEPRECATED(it6)) {
 1080                         public_ifa6 = NULL;
 1081                         break;
 1082                 }
 1083 
 1084                 /*
 1085                  * This is a public autoconf address that has the same prefix
 1086                  * as ours.  If it is preferred, keep it.  We can't break the
 1087                  * loop here, because there may be a still-preferred temporary
 1088                  * address with the prefix.
 1089                  */
 1090                 if (!IFA6_IS_DEPRECATED(it6))
 1091                         public_ifa6 = it6;
 1092         }
 1093         if (public_ifa6 != NULL)
 1094                 ifa_ref(&public_ifa6->ia_ifa);
 1095         IF_ADDR_RUNLOCK(ifp);
 1096 
 1097         if (public_ifa6 != NULL) {
 1098                 int e;
 1099 
 1100                 if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
 1101                         ifa_free(&public_ifa6->ia_ifa);
 1102                         log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
 1103                             " tmp addr,errno=%d\n", e);
 1104                         return (-1);
 1105                 }
 1106                 ifa_free(&public_ifa6->ia_ifa);
 1107                 return (0);
 1108         }
 1109 
 1110         return (-1);
 1111 }
 1112 
 1113 /*
 1114  * Remove prefix and default router list entries corresponding to ifp. Neighbor
 1115  * cache entries are freed in in6_domifdetach().
 1116  */
 1117 void
 1118 nd6_purge(struct ifnet *ifp)
 1119 {
 1120         struct nd_drhead drq;
 1121         struct nd_defrouter *dr, *ndr;
 1122         struct nd_prefix *pr, *npr;
 1123 
 1124         TAILQ_INIT(&drq);
 1125 
 1126         /*
 1127          * Nuke default router list entries toward ifp.
 1128          * We defer removal of default router list entries that is installed
 1129          * in the routing table, in order to keep additional side effects as
 1130          * small as possible.
 1131          */
 1132         ND6_WLOCK();
 1133         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
 1134                 if (dr->installed)
 1135                         continue;
 1136                 if (dr->ifp == ifp)
 1137                         defrouter_unlink(dr, &drq);
 1138         }
 1139 
 1140         TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
 1141                 if (!dr->installed)
 1142                         continue;
 1143                 if (dr->ifp == ifp)
 1144                         defrouter_unlink(dr, &drq);
 1145         }
 1146         ND6_WUNLOCK();
 1147 
 1148         while ((dr = TAILQ_FIRST(&drq)) != NULL) {
 1149                 TAILQ_REMOVE(&drq, dr, dr_entry);
 1150                 defrouter_del(dr);
 1151         }
 1152 
 1153         /* Nuke prefix list entries toward ifp */
 1154         LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
 1155                 if (pr->ndpr_ifp == ifp) {
 1156                         /*
 1157                          * Because if_detach() does *not* release prefixes
 1158                          * while purging addresses the reference count will
 1159                          * still be above zero. We therefore reset it to
 1160                          * make sure that the prefix really gets purged.
 1161                          */
 1162                         pr->ndpr_refcnt = 0;
 1163 
 1164                         prelist_remove(pr);
 1165                 }
 1166         }
 1167 
 1168         /* cancel default outgoing interface setting */
 1169         if (V_nd6_defifindex == ifp->if_index)
 1170                 nd6_setdefaultiface(0);
 1171 
 1172         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 1173                 /* Refresh default router list. */
 1174                 defrouter_select();
 1175         }
 1176 }
 1177 
 1178 /* 
 1179  * the caller acquires and releases the lock on the lltbls
 1180  * Returns the llentry locked
 1181  */
 1182 struct llentry *
 1183 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
 1184 {
 1185         struct sockaddr_in6 sin6;
 1186         struct llentry *ln;
 1187         
 1188         bzero(&sin6, sizeof(sin6));
 1189         sin6.sin6_len = sizeof(struct sockaddr_in6);
 1190         sin6.sin6_family = AF_INET6;
 1191         sin6.sin6_addr = *addr6;
 1192 
 1193         IF_AFDATA_LOCK_ASSERT(ifp);
 1194 
 1195         ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
 1196 
 1197         return (ln);
 1198 }
 1199 
 1200 struct llentry *
 1201 nd6_alloc(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         ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
 1212         if (ln != NULL)
 1213                 ln->ln_state = ND6_LLINFO_NOSTATE;
 1214 
 1215         return (ln);
 1216 }
 1217 
 1218 /*
 1219  * Test whether a given IPv6 address is a neighbor or not, ignoring
 1220  * the actual neighbor cache.  The neighbor cache is ignored in order
 1221  * to not reenter the routing code from within itself.
 1222  */
 1223 static int
 1224 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
 1225 {
 1226         struct nd_prefix *pr;
 1227         struct ifaddr *dstaddr;
 1228         struct rt_addrinfo info;
 1229         struct sockaddr_in6 rt_key;
 1230         struct sockaddr *dst6;
 1231         int fibnum;
 1232 
 1233         /*
 1234          * A link-local address is always a neighbor.
 1235          * XXX: a link does not necessarily specify a single interface.
 1236          */
 1237         if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
 1238                 struct sockaddr_in6 sin6_copy;
 1239                 u_int32_t zone;
 1240 
 1241                 /*
 1242                  * We need sin6_copy since sa6_recoverscope() may modify the
 1243                  * content (XXX).
 1244                  */
 1245                 sin6_copy = *addr;
 1246                 if (sa6_recoverscope(&sin6_copy))
 1247                         return (0); /* XXX: should be impossible */
 1248                 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
 1249                         return (0);
 1250                 if (sin6_copy.sin6_scope_id == zone)
 1251                         return (1);
 1252                 else
 1253                         return (0);
 1254         }
 1255 
 1256         bzero(&rt_key, sizeof(rt_key));
 1257         bzero(&info, sizeof(info));
 1258         info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key;
 1259 
 1260         /* Always use the default FIB here. XXME - why? */
 1261         fibnum = RT_DEFAULT_FIB;
 1262 
 1263         /*
 1264          * If the address matches one of our addresses,
 1265          * it should be a neighbor.
 1266          * If the address matches one of our on-link prefixes, it should be a
 1267          * neighbor.
 1268          */
 1269         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 1270                 if (pr->ndpr_ifp != ifp)
 1271                         continue;
 1272 
 1273                 if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) {
 1274 
 1275                         /* Always use the default FIB here. */
 1276                         dst6 = (struct sockaddr *)&pr->ndpr_prefix;
 1277 
 1278                         /* Restore length field before retrying lookup */
 1279                         rt_key.sin6_len = sizeof(rt_key);
 1280                         if (rib_lookup_info(fibnum, dst6, 0, 0, &info) != 0)
 1281                                 continue;
 1282                         /*
 1283                          * This is the case where multiple interfaces
 1284                          * have the same prefix, but only one is installed 
 1285                          * into the routing table and that prefix entry
 1286                          * is not the one being examined here. In the case
 1287                          * where RADIX_MPATH is enabled, multiple route
 1288                          * entries (of the same rt_key value) will be 
 1289                          * installed because the interface addresses all
 1290                          * differ.
 1291                          */
 1292                         if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
 1293                                &rt_key.sin6_addr))
 1294                                 continue;
 1295                 }
 1296 
 1297                 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
 1298                     &addr->sin6_addr, &pr->ndpr_mask))
 1299                         return (1);
 1300         }
 1301 
 1302         /*
 1303          * If the address is assigned on the node of the other side of
 1304          * a p2p interface, the address should be a neighbor.
 1305          */
 1306         dstaddr = ifa_ifwithdstaddr((const struct sockaddr *)addr, RT_ALL_FIBS);
 1307         if (dstaddr != NULL) {
 1308                 if (dstaddr->ifa_ifp == ifp) {
 1309                         ifa_free(dstaddr);
 1310                         return (1);
 1311                 }
 1312                 ifa_free(dstaddr);
 1313         }
 1314 
 1315         /*
 1316          * If the default router list is empty, all addresses are regarded
 1317          * as on-link, and thus, as a neighbor.
 1318          */
 1319         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
 1320             TAILQ_EMPTY(&V_nd_defrouter) &&
 1321             V_nd6_defifindex == ifp->if_index) {
 1322                 return (1);
 1323         }
 1324 
 1325         return (0);
 1326 }
 1327 
 1328 
 1329 /*
 1330  * Detect if a given IPv6 address identifies a neighbor on a given link.
 1331  * XXX: should take care of the destination of a p2p link?
 1332  */
 1333 int
 1334 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
 1335 {
 1336         struct llentry *lle;
 1337         int rc = 0;
 1338 
 1339         IF_AFDATA_UNLOCK_ASSERT(ifp);
 1340         if (nd6_is_new_addr_neighbor(addr, ifp))
 1341                 return (1);
 1342 
 1343         /*
 1344          * Even if the address matches none of our addresses, it might be
 1345          * in the neighbor cache.
 1346          */
 1347         IF_AFDATA_RLOCK(ifp);
 1348         if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
 1349                 LLE_RUNLOCK(lle);
 1350                 rc = 1;
 1351         }
 1352         IF_AFDATA_RUNLOCK(ifp);
 1353         return (rc);
 1354 }
 1355 
 1356 /*
 1357  * Free an nd6 llinfo entry.
 1358  * Since the function would cause significant changes in the kernel, DO NOT
 1359  * make it global, unless you have a strong reason for the change, and are sure
 1360  * that the change is safe.
 1361  *
 1362  * Set noinline to be dtrace-friendly
 1363  */
 1364 static __noinline void
 1365 nd6_free(struct llentry **lnp, int gc)
 1366 {
 1367         struct ifnet *ifp;
 1368         struct llentry *ln;
 1369         struct nd_defrouter *dr;
 1370 
 1371         ln = *lnp;
 1372         *lnp = NULL;
 1373 
 1374         LLE_WLOCK_ASSERT(ln);
 1375         ND6_RLOCK_ASSERT();
 1376 
 1377         ifp = lltable_get_ifp(ln->lle_tbl);
 1378         if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0)
 1379                 dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
 1380         else
 1381                 dr = NULL;
 1382         ND6_RUNLOCK();
 1383 
 1384         if ((ln->la_flags & LLE_DELETED) == 0)
 1385                 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
 1386 
 1387         /*
 1388          * we used to have pfctlinput(PRC_HOSTDEAD) here.
 1389          * even though it is not harmful, it was not really necessary.
 1390          */
 1391 
 1392         /* cancel timer */
 1393         nd6_llinfo_settimer_locked(ln, -1);
 1394 
 1395         if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 1396                 if (dr != NULL && dr->expire &&
 1397                     ln->ln_state == ND6_LLINFO_STALE && gc) {
 1398                         /*
 1399                          * If the reason for the deletion is just garbage
 1400                          * collection, and the neighbor is an active default
 1401                          * router, do not delete it.  Instead, reset the GC
 1402                          * timer using the router's lifetime.
 1403                          * Simply deleting the entry would affect default
 1404                          * router selection, which is not necessarily a good
 1405                          * thing, especially when we're using router preference
 1406                          * values.
 1407                          * XXX: the check for ln_state would be redundant,
 1408                          *      but we intentionally keep it just in case.
 1409                          */
 1410                         if (dr->expire > time_uptime)
 1411                                 nd6_llinfo_settimer_locked(ln,
 1412                                     (dr->expire - time_uptime) * hz);
 1413                         else
 1414                                 nd6_llinfo_settimer_locked(ln,
 1415                                     (long)V_nd6_gctimer * hz);
 1416 
 1417                         LLE_REMREF(ln);
 1418                         LLE_WUNLOCK(ln);
 1419                         defrouter_rele(dr);
 1420                         return;
 1421                 }
 1422 
 1423                 if (dr) {
 1424                         /*
 1425                          * Unreachablity of a router might affect the default
 1426                          * router selection and on-link detection of advertised
 1427                          * prefixes.
 1428                          */
 1429 
 1430                         /*
 1431                          * Temporarily fake the state to choose a new default
 1432                          * router and to perform on-link determination of
 1433                          * prefixes correctly.
 1434                          * Below the state will be set correctly,
 1435                          * or the entry itself will be deleted.
 1436                          */
 1437                         ln->ln_state = ND6_LLINFO_INCOMPLETE;
 1438                 }
 1439 
 1440                 if (ln->ln_router || dr) {
 1441 
 1442                         /*
 1443                          * We need to unlock to avoid a LOR with rt6_flush() with the
 1444                          * rnh and for the calls to pfxlist_onlink_check() and
 1445                          * defrouter_select() in the block further down for calls
 1446                          * into nd6_lookup().  We still hold a ref.
 1447                          */
 1448                         LLE_WUNLOCK(ln);
 1449 
 1450                         /*
 1451                          * rt6_flush must be called whether or not the neighbor
 1452                          * is in the Default Router List.
 1453                          * See a corresponding comment in nd6_na_input().
 1454                          */
 1455                         rt6_flush(&ln->r_l3addr.addr6, ifp);
 1456                 }
 1457 
 1458                 if (dr) {
 1459                         /*
 1460                          * Since defrouter_select() does not affect the
 1461                          * on-link determination and MIP6 needs the check
 1462                          * before the default router selection, we perform
 1463                          * the check now.
 1464                          */
 1465                         pfxlist_onlink_check();
 1466 
 1467                         /*
 1468                          * Refresh default router list.
 1469                          */
 1470                         defrouter_select();
 1471                 }
 1472 
 1473                 /*
 1474                  * If this entry was added by an on-link redirect, remove the
 1475                  * corresponding host route.
 1476                  */
 1477                 if (ln->la_flags & LLE_REDIRECT)
 1478                         nd6_free_redirect(ln);
 1479 
 1480                 if (ln->ln_router || dr)
 1481                         LLE_WLOCK(ln);
 1482         }
 1483 
 1484         /*
 1485          * Save to unlock. We still hold an extra reference and will not
 1486          * free(9) in llentry_free() if someone else holds one as well.
 1487          */
 1488         LLE_WUNLOCK(ln);
 1489         IF_AFDATA_LOCK(ifp);
 1490         LLE_WLOCK(ln);
 1491         /* Guard against race with other llentry_free(). */
 1492         if (ln->la_flags & LLE_LINKED) {
 1493                 /* Remove callout reference */
 1494                 LLE_REMREF(ln);
 1495                 lltable_unlink_entry(ln->lle_tbl, ln);
 1496         }
 1497         IF_AFDATA_UNLOCK(ifp);
 1498 
 1499         llentry_free(ln);
 1500         if (dr != NULL)
 1501                 defrouter_rele(dr);
 1502 }
 1503 
 1504 static int
 1505 nd6_isdynrte(const struct rtentry *rt, void *xap)
 1506 {
 1507 
 1508         if (rt->rt_flags == (RTF_UP | RTF_HOST | RTF_DYNAMIC))
 1509                 return (1);
 1510 
 1511         return (0);
 1512 }
 1513 /*
 1514  * Remove the rtentry for the given llentry,
 1515  * both of which were installed by a redirect.
 1516  */
 1517 static void
 1518 nd6_free_redirect(const struct llentry *ln)
 1519 {
 1520         int fibnum;
 1521         struct sockaddr_in6 sin6;
 1522         struct rt_addrinfo info;
 1523 
 1524         lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
 1525         memset(&info, 0, sizeof(info));
 1526         info.rti_info[RTAX_DST] = (struct sockaddr *)&sin6;
 1527         info.rti_filter = nd6_isdynrte;
 1528 
 1529         for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
 1530                 rtrequest1_fib(RTM_DELETE, &info, NULL, fibnum);
 1531 }
 1532 
 1533 /*
 1534  * Rejuvenate this function for routing operations related
 1535  * processing.
 1536  */
 1537 void
 1538 nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
 1539 {
 1540         struct sockaddr_in6 *gateway;
 1541         struct nd_defrouter *dr;
 1542         struct ifnet *ifp;
 1543 
 1544         gateway = (struct sockaddr_in6 *)rt->rt_gateway;
 1545         ifp = rt->rt_ifp;
 1546 
 1547         switch (req) {
 1548         case RTM_ADD:
 1549                 break;
 1550 
 1551         case RTM_DELETE:
 1552                 if (!ifp)
 1553                         return;
 1554                 /*
 1555                  * Only indirect routes are interesting.
 1556                  */
 1557                 if ((rt->rt_flags & RTF_GATEWAY) == 0)
 1558                         return;
 1559                 /*
 1560                  * check for default route
 1561                  */
 1562                 if (IN6_ARE_ADDR_EQUAL(&in6addr_any,
 1563                     &SIN6(rt_key(rt))->sin6_addr)) {
 1564                         dr = defrouter_lookup(&gateway->sin6_addr, ifp);
 1565                         if (dr != NULL) {
 1566                                 dr->installed = 0;
 1567                                 defrouter_rele(dr);
 1568                         }
 1569                 }
 1570                 break;
 1571         }
 1572 }
 1573 
 1574 
 1575 int
 1576 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
 1577 {
 1578         struct in6_ndireq *ndi = (struct in6_ndireq *)data;
 1579         struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
 1580         struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
 1581         int error = 0;
 1582 
 1583         if (ifp->if_afdata[AF_INET6] == NULL)
 1584                 return (EPFNOSUPPORT);
 1585         switch (cmd) {
 1586         case OSIOCGIFINFO_IN6:
 1587 #define ND      ndi->ndi
 1588                 /* XXX: old ndp(8) assumes a positive value for linkmtu. */
 1589                 bzero(&ND, sizeof(ND));
 1590                 ND.linkmtu = IN6_LINKMTU(ifp);
 1591                 ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
 1592                 ND.basereachable = ND_IFINFO(ifp)->basereachable;
 1593                 ND.reachable = ND_IFINFO(ifp)->reachable;
 1594                 ND.retrans = ND_IFINFO(ifp)->retrans;
 1595                 ND.flags = ND_IFINFO(ifp)->flags;
 1596                 ND.recalctm = ND_IFINFO(ifp)->recalctm;
 1597                 ND.chlim = ND_IFINFO(ifp)->chlim;
 1598                 break;
 1599         case SIOCGIFINFO_IN6:
 1600                 ND = *ND_IFINFO(ifp);
 1601                 break;
 1602         case SIOCSIFINFO_IN6:
 1603                 /*
 1604                  * used to change host variables from userland.
 1605                  * intended for a use on router to reflect RA configurations.
 1606                  */
 1607                 /* 0 means 'unspecified' */
 1608                 if (ND.linkmtu != 0) {
 1609                         if (ND.linkmtu < IPV6_MMTU ||
 1610                             ND.linkmtu > IN6_LINKMTU(ifp)) {
 1611                                 error = EINVAL;
 1612                                 break;
 1613                         }
 1614                         ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
 1615                 }
 1616 
 1617                 if (ND.basereachable != 0) {
 1618                         int obasereachable = ND_IFINFO(ifp)->basereachable;
 1619 
 1620                         ND_IFINFO(ifp)->basereachable = ND.basereachable;
 1621                         if (ND.basereachable != obasereachable)
 1622                                 ND_IFINFO(ifp)->reachable =
 1623                                     ND_COMPUTE_RTIME(ND.basereachable);
 1624                 }
 1625                 if (ND.retrans != 0)
 1626                         ND_IFINFO(ifp)->retrans = ND.retrans;
 1627                 if (ND.chlim != 0)
 1628                         ND_IFINFO(ifp)->chlim = ND.chlim;
 1629                 /* FALLTHROUGH */
 1630         case SIOCSIFINFO_FLAGS:
 1631         {
 1632                 struct ifaddr *ifa;
 1633                 struct in6_ifaddr *ia;
 1634 
 1635                 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
 1636                     !(ND.flags & ND6_IFF_IFDISABLED)) {
 1637                         /* ifdisabled 1->0 transision */
 1638 
 1639                         /*
 1640                          * If the interface is marked as ND6_IFF_IFDISABLED and
 1641                          * has an link-local address with IN6_IFF_DUPLICATED,
 1642                          * do not clear ND6_IFF_IFDISABLED.
 1643                          * See RFC 4862, Section 5.4.5.
 1644                          */
 1645                         IF_ADDR_RLOCK(ifp);
 1646                         TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1647                                 if (ifa->ifa_addr->sa_family != AF_INET6)
 1648                                         continue;
 1649                                 ia = (struct in6_ifaddr *)ifa;
 1650                                 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
 1651                                     IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
 1652                                         break;
 1653                         }
 1654                         IF_ADDR_RUNLOCK(ifp);
 1655 
 1656                         if (ifa != NULL) {
 1657                                 /* LLA is duplicated. */
 1658                                 ND.flags |= ND6_IFF_IFDISABLED;
 1659                                 log(LOG_ERR, "Cannot enable an interface"
 1660                                     " with a link-local address marked"
 1661                                     " duplicate.\n");
 1662                         } else {
 1663                                 ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
 1664                                 if (ifp->if_flags & IFF_UP)
 1665                                         in6_if_up(ifp);
 1666                         }
 1667                 } else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
 1668                             (ND.flags & ND6_IFF_IFDISABLED)) {
 1669                         /* ifdisabled 0->1 transision */
 1670                         /* Mark all IPv6 address as tentative. */
 1671 
 1672                         ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
 1673                         if (V_ip6_dad_count > 0 &&
 1674                             (ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
 1675                                 IF_ADDR_RLOCK(ifp);
 1676                                 TAILQ_FOREACH(ifa, &ifp->if_addrhead,
 1677                                     ifa_link) {
 1678                                         if (ifa->ifa_addr->sa_family !=
 1679                                             AF_INET6)
 1680                                                 continue;
 1681                                         ia = (struct in6_ifaddr *)ifa;
 1682                                         ia->ia6_flags |= IN6_IFF_TENTATIVE;
 1683                                 }
 1684                                 IF_ADDR_RUNLOCK(ifp);
 1685                         }
 1686                 }
 1687 
 1688                 if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
 1689                         if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
 1690                                 /* auto_linklocal 0->1 transision */
 1691 
 1692                                 /* If no link-local address on ifp, configure */
 1693                                 ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
 1694                                 in6_ifattach(ifp, NULL);
 1695                         } else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
 1696                             ifp->if_flags & IFF_UP) {
 1697                                 /*
 1698                                  * When the IF already has
 1699                                  * ND6_IFF_AUTO_LINKLOCAL, no link-local
 1700                                  * address is assigned, and IFF_UP, try to
 1701                                  * assign one.
 1702                                  */
 1703                                 IF_ADDR_RLOCK(ifp);
 1704                                 TAILQ_FOREACH(ifa, &ifp->if_addrhead,
 1705                                     ifa_link) {
 1706                                         if (ifa->ifa_addr->sa_family !=
 1707                                             AF_INET6)
 1708                                                 continue;
 1709                                         ia = (struct in6_ifaddr *)ifa;
 1710                                         if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
 1711                                                 break;
 1712                                 }
 1713                                 IF_ADDR_RUNLOCK(ifp);
 1714                                 if (ifa != NULL)
 1715                                         /* No LLA is configured. */
 1716                                         in6_ifattach(ifp, NULL);
 1717                         }
 1718                 }
 1719         }
 1720                 ND_IFINFO(ifp)->flags = ND.flags;
 1721                 break;
 1722 #undef ND
 1723         case SIOCSNDFLUSH_IN6:  /* XXX: the ioctl name is confusing... */
 1724                 /* sync kernel routing table with the default router list */
 1725                 defrouter_reset();
 1726                 defrouter_select();
 1727                 break;
 1728         case SIOCSPFXFLUSH_IN6:
 1729         {
 1730                 /* flush all the prefix advertised by routers */
 1731                 struct nd_prefix *pr, *next;
 1732 
 1733                 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
 1734                         struct in6_ifaddr *ia, *ia_next;
 1735 
 1736                         if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
 1737                                 continue; /* XXX */
 1738 
 1739                         /* do we really have to remove addresses as well? */
 1740                         /* XXXRW: in6_ifaddrhead locking. */
 1741                         TAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
 1742                             ia_next) {
 1743                                 if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
 1744                                         continue;
 1745 
 1746                                 if (ia->ia6_ndpr == pr)
 1747                                         in6_purgeaddr(&ia->ia_ifa);
 1748                         }
 1749                         prelist_remove(pr);
 1750                 }
 1751                 break;
 1752         }
 1753         case SIOCSRTRFLUSH_IN6:
 1754         {
 1755                 /* flush all the default routers */
 1756                 struct nd_drhead drq;
 1757                 struct nd_defrouter *dr;
 1758 
 1759                 TAILQ_INIT(&drq);
 1760 
 1761                 defrouter_reset();
 1762 
 1763                 ND6_WLOCK();
 1764                 while ((dr = TAILQ_FIRST(&V_nd_defrouter)) != NULL)
 1765                         defrouter_unlink(dr, &drq);
 1766                 ND6_WUNLOCK();
 1767                 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
 1768                         TAILQ_REMOVE(&drq, dr, dr_entry);
 1769                         defrouter_del(dr);
 1770                 }
 1771 
 1772                 defrouter_select();
 1773                 break;
 1774         }
 1775         case SIOCGNBRINFO_IN6:
 1776         {
 1777                 struct llentry *ln;
 1778                 struct in6_addr nb_addr = nbi->addr; /* make local for safety */
 1779 
 1780                 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
 1781                         return (error);
 1782 
 1783                 IF_AFDATA_RLOCK(ifp);
 1784                 ln = nd6_lookup(&nb_addr, 0, ifp);
 1785                 IF_AFDATA_RUNLOCK(ifp);
 1786 
 1787                 if (ln == NULL) {
 1788                         error = EINVAL;
 1789                         break;
 1790                 }
 1791                 nbi->state = ln->ln_state;
 1792                 nbi->asked = ln->la_asked;
 1793                 nbi->isrouter = ln->ln_router;
 1794                 if (ln->la_expire == 0)
 1795                         nbi->expire = 0;
 1796                 else
 1797                         nbi->expire = ln->la_expire + ln->lle_remtime / hz +
 1798                             (time_second - time_uptime);
 1799                 LLE_RUNLOCK(ln);
 1800                 break;
 1801         }
 1802         case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
 1803                 ndif->ifindex = V_nd6_defifindex;
 1804                 break;
 1805         case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
 1806                 return (nd6_setdefaultiface(ndif->ifindex));
 1807         }
 1808         return (error);
 1809 }
 1810 
 1811 /*
 1812  * Calculates new isRouter value based on provided parameters and
 1813  * returns it.
 1814  */
 1815 static int
 1816 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
 1817     int ln_router)
 1818 {
 1819 
 1820         /*
 1821          * ICMP6 type dependent behavior.
 1822          *
 1823          * NS: clear IsRouter if new entry
 1824          * RS: clear IsRouter
 1825          * RA: set IsRouter if there's lladdr
 1826          * redir: clear IsRouter if new entry
 1827          *
 1828          * RA case, (1):
 1829          * The spec says that we must set IsRouter in the following cases:
 1830          * - If lladdr exist, set IsRouter.  This means (1-5).
 1831          * - If it is old entry (!newentry), set IsRouter.  This means (7).
 1832          * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
 1833          * A quetion arises for (1) case.  (1) case has no lladdr in the
 1834          * neighbor cache, this is similar to (6).
 1835          * This case is rare but we figured that we MUST NOT set IsRouter.
 1836          *
 1837          *   is_new  old_addr new_addr      NS  RS  RA  redir
 1838          *                                                      D R
 1839          *      0       n       n       (1)     c   ?     s
 1840          *      0       y       n       (2)     c   s     s
 1841          *      0       n       y       (3)     c   s     s
 1842          *      0       y       y       (4)     c   s     s
 1843          *      0       y       y       (5)     c   s     s
 1844          *      1       --      n       (6) c   c       c s
 1845          *      1       --      y       (7) c   c   s   c s
 1846          *
 1847          *                                      (c=clear s=set)
 1848          */
 1849         switch (type & 0xff) {
 1850         case ND_NEIGHBOR_SOLICIT:
 1851                 /*
 1852                  * New entry must have is_router flag cleared.
 1853                  */
 1854                 if (is_new)                                     /* (6-7) */
 1855                         ln_router = 0;
 1856                 break;
 1857         case ND_REDIRECT:
 1858                 /*
 1859                  * If the icmp is a redirect to a better router, always set the
 1860                  * is_router flag.  Otherwise, if the entry is newly created,
 1861                  * clear the flag.  [RFC 2461, sec 8.3]
 1862                  */
 1863                 if (code == ND_REDIRECT_ROUTER)
 1864                         ln_router = 1;
 1865                 else {
 1866                         if (is_new)                             /* (6-7) */
 1867                                 ln_router = 0;
 1868                 }
 1869                 break;
 1870         case ND_ROUTER_SOLICIT:
 1871                 /*
 1872                  * is_router flag must always be cleared.
 1873                  */
 1874                 ln_router = 0;
 1875                 break;
 1876         case ND_ROUTER_ADVERT:
 1877                 /*
 1878                  * Mark an entry with lladdr as a router.
 1879                  */
 1880                 if ((!is_new && (old_addr || new_addr)) ||      /* (2-5) */
 1881                     (is_new && new_addr)) {                     /* (7) */
 1882                         ln_router = 1;
 1883                 }
 1884                 break;
 1885         }
 1886 
 1887         return (ln_router);
 1888 }
 1889 
 1890 /*
 1891  * Create neighbor cache entry and cache link-layer address,
 1892  * on reception of inbound ND6 packets.  (RS/RA/NS/redirect)
 1893  *
 1894  * type - ICMP6 type
 1895  * code - type dependent information
 1896  *
 1897  */
 1898 void
 1899 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
 1900     int lladdrlen, int type, int code)
 1901 {
 1902         struct llentry *ln = NULL, *ln_tmp;
 1903         int is_newentry;
 1904         int do_update;
 1905         int olladdr;
 1906         int llchange;
 1907         int flags;
 1908         uint16_t router = 0;
 1909         struct sockaddr_in6 sin6;
 1910         struct mbuf *chain = NULL;
 1911         u_char linkhdr[LLE_MAX_LINKHDR];
 1912         size_t linkhdrsize;
 1913         int lladdr_off;
 1914 
 1915         IF_AFDATA_UNLOCK_ASSERT(ifp);
 1916 
 1917         KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
 1918         KASSERT(from != NULL, ("%s: from == NULL", __func__));
 1919 
 1920         /* nothing must be updated for unspecified address */
 1921         if (IN6_IS_ADDR_UNSPECIFIED(from))
 1922                 return;
 1923 
 1924         /*
 1925          * Validation about ifp->if_addrlen and lladdrlen must be done in
 1926          * the caller.
 1927          *
 1928          * XXX If the link does not have link-layer adderss, what should
 1929          * we do? (ifp->if_addrlen == 0)
 1930          * Spec says nothing in sections for RA, RS and NA.  There's small
 1931          * description on it in NS section (RFC 2461 7.2.3).
 1932          */
 1933         flags = lladdr ? LLE_EXCLUSIVE : 0;
 1934         IF_AFDATA_RLOCK(ifp);
 1935         ln = nd6_lookup(from, flags, ifp);
 1936         IF_AFDATA_RUNLOCK(ifp);
 1937         is_newentry = 0;
 1938         if (ln == NULL) {
 1939                 flags |= LLE_EXCLUSIVE;
 1940                 ln = nd6_alloc(from, 0, ifp);
 1941                 if (ln == NULL)
 1942                         return;
 1943 
 1944                 /*
 1945                  * Since we already know all the data for the new entry,
 1946                  * fill it before insertion.
 1947                  */
 1948                 if (lladdr != NULL) {
 1949                         linkhdrsize = sizeof(linkhdr);
 1950                         if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
 1951                             linkhdr, &linkhdrsize, &lladdr_off) != 0)
 1952                                 return;
 1953                         lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
 1954                             lladdr_off);
 1955                 }
 1956 
 1957                 IF_AFDATA_WLOCK(ifp);
 1958                 LLE_WLOCK(ln);
 1959                 /* Prefer any existing lle over newly-created one */
 1960                 ln_tmp = nd6_lookup(from, LLE_EXCLUSIVE, ifp);
 1961                 if (ln_tmp == NULL)
 1962                         lltable_link_entry(LLTABLE6(ifp), ln);
 1963                 IF_AFDATA_WUNLOCK(ifp);
 1964                 if (ln_tmp == NULL) {
 1965                         /* No existing lle, mark as new entry (6,7) */
 1966                         is_newentry = 1;
 1967                         nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
 1968                         if (lladdr != NULL)     /* (7) */
 1969                                 EVENTHANDLER_INVOKE(lle_event, ln,
 1970                                     LLENTRY_RESOLVED);
 1971                 } else {
 1972                         lltable_free_entry(LLTABLE6(ifp), ln);
 1973                         ln = ln_tmp;
 1974                         ln_tmp = NULL;
 1975                 }
 1976         } 
 1977         /* do nothing if static ndp is set */
 1978         if ((ln->la_flags & LLE_STATIC)) {
 1979                 if (flags & LLE_EXCLUSIVE)
 1980                         LLE_WUNLOCK(ln);
 1981                 else
 1982                         LLE_RUNLOCK(ln);
 1983                 return;
 1984         }
 1985 
 1986         olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
 1987         if (olladdr && lladdr) {
 1988                 llchange = bcmp(lladdr, ln->ll_addr,
 1989                     ifp->if_addrlen);
 1990         } else if (!olladdr && lladdr)
 1991                 llchange = 1;
 1992         else
 1993                 llchange = 0;
 1994 
 1995         /*
 1996          * newentry olladdr  lladdr  llchange   (*=record)
 1997          *      0       n       n       --      (1)
 1998          *      0       y       n       --      (2)
 1999          *      0       n       y       y       (3) * STALE
 2000          *      0       y       y       n       (4) *
 2001          *      0       y       y       y       (5) * STALE
 2002          *      1       --      n       --      (6)   NOSTATE(= PASSIVE)
 2003          *      1       --      y       --      (7) * STALE
 2004          */
 2005 
 2006         do_update = 0;
 2007         if (is_newentry == 0 && llchange != 0) {
 2008                 do_update = 1;  /* (3,5) */
 2009 
 2010                 /*
 2011                  * Record source link-layer address
 2012                  * XXX is it dependent to ifp->if_type?
 2013                  */
 2014                 linkhdrsize = sizeof(linkhdr);
 2015                 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
 2016                     linkhdr, &linkhdrsize, &lladdr_off) != 0)
 2017                         return;
 2018 
 2019                 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
 2020                     lladdr_off) == 0) {
 2021                         /* Entry was deleted */
 2022                         return;
 2023                 }
 2024 
 2025                 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
 2026 
 2027                 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
 2028 
 2029                 if (ln->la_hold != NULL)
 2030                         nd6_grab_holdchain(ln, &chain, &sin6);
 2031         }
 2032 
 2033         /* Calculates new router status */
 2034         router = nd6_is_router(type, code, is_newentry, olladdr,
 2035             lladdr != NULL ? 1 : 0, ln->ln_router);
 2036 
 2037         ln->ln_router = router;
 2038         /* Mark non-router redirects with special flag */
 2039         if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
 2040                 ln->la_flags |= LLE_REDIRECT;
 2041 
 2042         if (flags & LLE_EXCLUSIVE)
 2043                 LLE_WUNLOCK(ln);
 2044         else
 2045                 LLE_RUNLOCK(ln);
 2046 
 2047         if (chain != NULL)
 2048                 nd6_flush_holdchain(ifp, ifp, chain, &sin6);
 2049         
 2050         /*
 2051          * When the link-layer address of a router changes, select the
 2052          * best router again.  In particular, when the neighbor entry is newly
 2053          * created, it might affect the selection policy.
 2054          * Question: can we restrict the first condition to the "is_newentry"
 2055          * case?
 2056          * XXX: when we hear an RA from a new router with the link-layer
 2057          * address option, defrouter_select() is called twice, since
 2058          * defrtrlist_update called the function as well.  However, I believe
 2059          * we can compromise the overhead, since it only happens the first
 2060          * time.
 2061          * XXX: although defrouter_select() should not have a bad effect
 2062          * for those are not autoconfigured hosts, we explicitly avoid such
 2063          * cases for safety.
 2064          */
 2065         if ((do_update || is_newentry) && router &&
 2066             ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
 2067                 /*
 2068                  * guaranteed recursion
 2069                  */
 2070                 defrouter_select();
 2071         }
 2072 }
 2073 
 2074 static void
 2075 nd6_slowtimo(void *arg)
 2076 {
 2077         CURVNET_SET((struct vnet *) arg);
 2078         struct nd_ifinfo *nd6if;
 2079         struct ifnet *ifp;
 2080 
 2081         callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
 2082             nd6_slowtimo, curvnet);
 2083         IFNET_RLOCK_NOSLEEP();
 2084         TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 2085                 if (ifp->if_afdata[AF_INET6] == NULL)
 2086                         continue;
 2087                 nd6if = ND_IFINFO(ifp);
 2088                 if (nd6if->basereachable && /* already initialized */
 2089                     (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
 2090                         /*
 2091                          * Since reachable time rarely changes by router
 2092                          * advertisements, we SHOULD insure that a new random
 2093                          * value gets recomputed at least once every few hours.
 2094                          * (RFC 2461, 6.3.4)
 2095                          */
 2096                         nd6if->recalctm = V_nd6_recalc_reachtm_interval;
 2097                         nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
 2098                 }
 2099         }
 2100         IFNET_RUNLOCK_NOSLEEP();
 2101         CURVNET_RESTORE();
 2102 }
 2103 
 2104 void
 2105 nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
 2106     struct sockaddr_in6 *sin6)
 2107 {
 2108 
 2109         LLE_WLOCK_ASSERT(ln);
 2110 
 2111         *chain = ln->la_hold;
 2112         ln->la_hold = NULL;
 2113         lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
 2114 
 2115         if (ln->ln_state == ND6_LLINFO_STALE) {
 2116 
 2117                 /*
 2118                  * The first time we send a packet to a
 2119                  * neighbor whose entry is STALE, we have
 2120                  * to change the state to DELAY and a sets
 2121                  * a timer to expire in DELAY_FIRST_PROBE_TIME
 2122                  * seconds to ensure do neighbor unreachability
 2123                  * detection on expiration.
 2124                  * (RFC 2461 7.3.3)
 2125                  */
 2126                 nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
 2127         }
 2128 }
 2129 
 2130 int
 2131 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
 2132     struct sockaddr_in6 *dst, struct route *ro)
 2133 {
 2134         int error;
 2135         int ip6len;
 2136         struct ip6_hdr *ip6;
 2137         struct m_tag *mtag;
 2138 
 2139 #ifdef MAC
 2140         mac_netinet6_nd6_send(ifp, m);
 2141 #endif
 2142 
 2143         /*
 2144          * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
 2145          * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
 2146          * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
 2147          * to be diverted to user space.  When re-injected into the kernel,
 2148          * send_output() will directly dispatch them to the outgoing interface.
 2149          */
 2150         if (send_sendso_input_hook != NULL) {
 2151                 mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
 2152                 if (mtag != NULL) {
 2153                         ip6 = mtod(m, struct ip6_hdr *);
 2154                         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 2155                         /* Use the SEND socket */
 2156                         error = send_sendso_input_hook(m, ifp, SND_OUT,
 2157                             ip6len);
 2158                         /* -1 == no app on SEND socket */
 2159                         if (error == 0 || error != -1)
 2160                             return (error);
 2161                 }
 2162         }
 2163 
 2164         m_clrprotoflags(m);     /* Avoid confusing lower layers. */
 2165         IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
 2166             mtod(m, struct ip6_hdr *));
 2167 
 2168         if ((ifp->if_flags & IFF_LOOPBACK) == 0)
 2169                 origifp = ifp;
 2170 
 2171         error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
 2172         return (error);
 2173 }
 2174 
 2175 /*
 2176  * Lookup link headerfor @sa_dst address. Stores found
 2177  * data in @desten buffer. Copy of lle ln_flags can be also
 2178  * saved in @pflags if @pflags is non-NULL.
 2179  *
 2180  * If destination LLE does not exists or lle state modification
 2181  * is required, call "slow" version.
 2182  *
 2183  * Return values:
 2184  * - 0 on success (address copied to buffer).
 2185  * - EWOULDBLOCK (no local error, but address is still unresolved)
 2186  * - other errors (alloc failure, etc)
 2187  */
 2188 int
 2189 nd6_resolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
 2190     const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
 2191     struct llentry **plle)
 2192 {
 2193         struct llentry *ln = NULL;
 2194         const struct sockaddr_in6 *dst6;
 2195 
 2196         if (pflags != NULL)
 2197                 *pflags = 0;
 2198 
 2199         dst6 = (const struct sockaddr_in6 *)sa_dst;
 2200 
 2201         /* discard the packet if IPv6 operation is disabled on the interface */
 2202         if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
 2203                 m_freem(m);
 2204                 return (ENETDOWN); /* better error? */
 2205         }
 2206 
 2207         if (m != NULL && m->m_flags & M_MCAST) {
 2208                 switch (ifp->if_type) {
 2209                 case IFT_ETHER:
 2210                 case IFT_FDDI:
 2211                 case IFT_L2VLAN:
 2212                 case IFT_IEEE80211:
 2213                 case IFT_BRIDGE:
 2214                 case IFT_ISO88025:
 2215                         ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
 2216                                                  desten);
 2217                         return (0);
 2218                 default:
 2219                         m_freem(m);
 2220                         return (EAFNOSUPPORT);
 2221                 }
 2222         }
 2223 
 2224         IF_AFDATA_RLOCK(ifp);
 2225         ln = nd6_lookup(&dst6->sin6_addr, plle ? LLE_EXCLUSIVE : LLE_UNLOCKED,
 2226             ifp);
 2227         if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
 2228                 /* Entry found, let's copy lle info */
 2229                 bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
 2230                 if (pflags != NULL)
 2231                         *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
 2232                 /* Check if we have feedback request from nd6 timer */
 2233                 if (ln->r_skip_req != 0) {
 2234                         LLE_REQ_LOCK(ln);
 2235                         ln->r_skip_req = 0; /* Notify that entry was used */
 2236                         ln->lle_hittime = time_uptime;
 2237                         LLE_REQ_UNLOCK(ln);
 2238                 }
 2239                 if (plle) {
 2240                         LLE_ADDREF(ln);
 2241                         *plle = ln;
 2242                         LLE_WUNLOCK(ln);
 2243                 }
 2244                 IF_AFDATA_RUNLOCK(ifp);
 2245                 return (0);
 2246         } else if (plle && ln)
 2247                 LLE_WUNLOCK(ln);
 2248         IF_AFDATA_RUNLOCK(ifp);
 2249 
 2250         return (nd6_resolve_slow(ifp, 0, m, dst6, desten, pflags, plle));
 2251 }
 2252 
 2253 
 2254 /*
 2255  * Do L2 address resolution for @sa_dst address. Stores found
 2256  * address in @desten buffer. Copy of lle ln_flags can be also
 2257  * saved in @pflags if @pflags is non-NULL.
 2258  *
 2259  * Heavy version.
 2260  * Function assume that destination LLE does not exist,
 2261  * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
 2262  *
 2263  * Set noinline to be dtrace-friendly
 2264  */
 2265 static __noinline int
 2266 nd6_resolve_slow(struct ifnet *ifp, int flags, struct mbuf *m,
 2267     const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
 2268     struct llentry **plle)
 2269 {
 2270         struct llentry *lle = NULL, *lle_tmp;
 2271         struct in6_addr *psrc, src;
 2272         int send_ns, ll_len;
 2273         char *lladdr;
 2274 
 2275         /*
 2276          * Address resolution or Neighbor Unreachability Detection
 2277          * for the next hop.
 2278          * At this point, the destination of the packet must be a unicast
 2279          * or an anycast address(i.e. not a multicast).
 2280          */
 2281         if (lle == NULL) {
 2282                 IF_AFDATA_RLOCK(ifp);
 2283                 lle = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
 2284                 IF_AFDATA_RUNLOCK(ifp);
 2285                 if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp))  {
 2286                         /*
 2287                          * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
 2288                          * the condition below is not very efficient.  But we believe
 2289                          * it is tolerable, because this should be a rare case.
 2290                          */
 2291                         lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
 2292                         if (lle == NULL) {
 2293                                 char ip6buf[INET6_ADDRSTRLEN];
 2294                                 log(LOG_DEBUG,
 2295                                     "nd6_output: can't allocate llinfo for %s "
 2296                                     "(ln=%p)\n",
 2297                                     ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
 2298                                 m_freem(m);
 2299                                 return (ENOBUFS);
 2300                         }
 2301 
 2302                         IF_AFDATA_WLOCK(ifp);
 2303                         LLE_WLOCK(lle);
 2304                         /* Prefer any existing entry over newly-created one */
 2305                         lle_tmp = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
 2306                         if (lle_tmp == NULL)
 2307                                 lltable_link_entry(LLTABLE6(ifp), lle);
 2308                         IF_AFDATA_WUNLOCK(ifp);
 2309                         if (lle_tmp != NULL) {
 2310                                 lltable_free_entry(LLTABLE6(ifp), lle);
 2311                                 lle = lle_tmp;
 2312                                 lle_tmp = NULL;
 2313                         }
 2314                 }
 2315         } 
 2316         if (lle == NULL) {
 2317                 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
 2318                         m_freem(m);
 2319                         return (ENOBUFS);
 2320                 }
 2321 
 2322                 if (m != NULL)
 2323                         m_freem(m);
 2324                 return (ENOBUFS);
 2325         }
 2326 
 2327         LLE_WLOCK_ASSERT(lle);
 2328 
 2329         /*
 2330          * The first time we send a packet to a neighbor whose entry is
 2331          * STALE, we have to change the state to DELAY and a sets a timer to
 2332          * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
 2333          * neighbor unreachability detection on expiration.
 2334          * (RFC 2461 7.3.3)
 2335          */
 2336         if (lle->ln_state == ND6_LLINFO_STALE)
 2337                 nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
 2338 
 2339         /*
 2340          * If the neighbor cache entry has a state other than INCOMPLETE
 2341          * (i.e. its link-layer address is already resolved), just
 2342          * send the packet.
 2343          */
 2344         if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
 2345                 if (flags & LLE_ADDRONLY) {
 2346                         lladdr = lle->ll_addr;
 2347                         ll_len = ifp->if_addrlen;
 2348                 } else {
 2349                         lladdr = lle->r_linkdata;
 2350                         ll_len = lle->r_hdrlen;
 2351                 }
 2352                 bcopy(lladdr, desten, ll_len);
 2353                 if (pflags != NULL)
 2354                         *pflags = lle->la_flags;
 2355                 if (plle) {
 2356                         LLE_ADDREF(lle);
 2357                         *plle = lle;
 2358                 }
 2359                 LLE_WUNLOCK(lle);
 2360                 return (0);
 2361         }
 2362 
 2363         /*
 2364          * There is a neighbor cache entry, but no ethernet address
 2365          * response yet.  Append this latest packet to the end of the
 2366          * packet queue in the mbuf.  When it exceeds nd6_maxqueuelen,
 2367          * the oldest packet in the queue will be removed.
 2368          */
 2369 
 2370         if (lle->la_hold != NULL) {
 2371                 struct mbuf *m_hold;
 2372                 int i;
 2373                 
 2374                 i = 0;
 2375                 for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){
 2376                         i++;
 2377                         if (m_hold->m_nextpkt == NULL) {
 2378                                 m_hold->m_nextpkt = m;
 2379                                 break;
 2380                         }
 2381                 }
 2382                 while (i >= V_nd6_maxqueuelen) {
 2383                         m_hold = lle->la_hold;
 2384                         lle->la_hold = lle->la_hold->m_nextpkt;
 2385                         m_freem(m_hold);
 2386                         i--;
 2387                 }
 2388         } else {
 2389                 lle->la_hold = m;
 2390         }
 2391 
 2392         /*
 2393          * If there has been no NS for the neighbor after entering the
 2394          * INCOMPLETE state, send the first solicitation.
 2395          * Note that for newly-created lle la_asked will be 0,
 2396          * so we will transition from ND6_LLINFO_NOSTATE to
 2397          * ND6_LLINFO_INCOMPLETE state here.
 2398          */
 2399         psrc = NULL;
 2400         send_ns = 0;
 2401         if (lle->la_asked == 0) {
 2402                 lle->la_asked++;
 2403                 send_ns = 1;
 2404                 psrc = nd6_llinfo_get_holdsrc(lle, &src);
 2405 
 2406                 nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
 2407         }
 2408         LLE_WUNLOCK(lle);
 2409         if (send_ns != 0)
 2410                 nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
 2411 
 2412         return (EWOULDBLOCK);
 2413 }
 2414 
 2415 /*
 2416  * Do L2 address resolution for @sa_dst address. Stores found
 2417  * address in @desten buffer. Copy of lle ln_flags can be also
 2418  * saved in @pflags if @pflags is non-NULL.
 2419  *
 2420  * Return values:
 2421  * - 0 on success (address copied to buffer).
 2422  * - EWOULDBLOCK (no local error, but address is still unresolved)
 2423  * - other errors (alloc failure, etc)
 2424  */
 2425 int
 2426 nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
 2427     char *desten, uint32_t *pflags)
 2428 {
 2429         int error;
 2430 
 2431         flags |= LLE_ADDRONLY;
 2432         error = nd6_resolve_slow(ifp, flags, NULL,
 2433             (const struct sockaddr_in6 *)dst, desten, pflags, NULL);
 2434         return (error);
 2435 }
 2436 
 2437 int
 2438 nd6_flush_holdchain(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
 2439     struct sockaddr_in6 *dst)
 2440 {
 2441         struct mbuf *m, *m_head;
 2442         struct ifnet *outifp;
 2443         int error = 0;
 2444 
 2445         m_head = chain;
 2446         if ((ifp->if_flags & IFF_LOOPBACK) != 0)
 2447                 outifp = origifp;
 2448         else
 2449                 outifp = ifp;
 2450         
 2451         while (m_head) {
 2452                 m = m_head;
 2453                 m_head = m_head->m_nextpkt;
 2454                 error = nd6_output_ifp(ifp, origifp, m, dst, NULL);
 2455         }
 2456 
 2457         /*
 2458          * XXX
 2459          * note that intermediate errors are blindly ignored
 2460          */
 2461         return (error);
 2462 }       
 2463 
 2464 static int
 2465 nd6_need_cache(struct ifnet *ifp)
 2466 {
 2467         /*
 2468          * XXX: we currently do not make neighbor cache on any interface
 2469          * other than ARCnet, Ethernet, FDDI and GIF.
 2470          *
 2471          * RFC2893 says:
 2472          * - unidirectional tunnels needs no ND
 2473          */
 2474         switch (ifp->if_type) {
 2475         case IFT_ARCNET:
 2476         case IFT_ETHER:
 2477         case IFT_FDDI:
 2478         case IFT_IEEE1394:
 2479         case IFT_L2VLAN:
 2480         case IFT_IEEE80211:
 2481         case IFT_INFINIBAND:
 2482         case IFT_BRIDGE:
 2483         case IFT_PROPVIRTUAL:
 2484                 return (1);
 2485         default:
 2486                 return (0);
 2487         }
 2488 }
 2489 
 2490 /*
 2491  * Add pernament ND6 link-layer record for given
 2492  * interface address.
 2493  *
 2494  * Very similar to IPv4 arp_ifinit(), but:
 2495  * 1) IPv6 DAD is performed in different place
 2496  * 2) It is called by IPv6 protocol stack in contrast to
 2497  * arp_ifinit() which is typically called in SIOCSIFADDR
 2498  * driver ioctl handler.
 2499  *
 2500  */
 2501 int
 2502 nd6_add_ifa_lle(struct in6_ifaddr *ia)
 2503 {
 2504         struct ifnet *ifp;
 2505         struct llentry *ln, *ln_tmp;
 2506         struct sockaddr *dst;
 2507 
 2508         ifp = ia->ia_ifa.ifa_ifp;
 2509         if (nd6_need_cache(ifp) == 0)
 2510                 return (0);
 2511 
 2512         ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
 2513         dst = (struct sockaddr *)&ia->ia_addr;
 2514         ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
 2515         if (ln == NULL)
 2516                 return (ENOBUFS);
 2517 
 2518         IF_AFDATA_WLOCK(ifp);
 2519         LLE_WLOCK(ln);
 2520         /* Unlink any entry if exists */
 2521         ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
 2522         if (ln_tmp != NULL)
 2523                 lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
 2524         lltable_link_entry(LLTABLE6(ifp), ln);
 2525         IF_AFDATA_WUNLOCK(ifp);
 2526 
 2527         if (ln_tmp != NULL)
 2528                 EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
 2529         EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
 2530 
 2531         LLE_WUNLOCK(ln);
 2532         if (ln_tmp != NULL)
 2533                 llentry_free(ln_tmp);
 2534 
 2535         return (0);
 2536 }
 2537 
 2538 /*
 2539  * Removes either all lle entries for given @ia, or lle
 2540  * corresponding to @ia address.
 2541  */
 2542 void
 2543 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
 2544 {
 2545         struct sockaddr_in6 mask, addr;
 2546         struct sockaddr *saddr, *smask;
 2547         struct ifnet *ifp;
 2548 
 2549         ifp = ia->ia_ifa.ifa_ifp;
 2550         memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
 2551         memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
 2552         saddr = (struct sockaddr *)&addr;
 2553         smask = (struct sockaddr *)&mask;
 2554 
 2555         if (all != 0)
 2556                 lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
 2557         else
 2558                 lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
 2559 }
 2560 
 2561 static void 
 2562 clear_llinfo_pqueue(struct llentry *ln)
 2563 {
 2564         struct mbuf *m_hold, *m_hold_next;
 2565 
 2566         for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
 2567                 m_hold_next = m_hold->m_nextpkt;
 2568                 m_freem(m_hold);
 2569         }
 2570 
 2571         ln->la_hold = NULL;
 2572 }
 2573 
 2574 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
 2575 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
 2576 
 2577 SYSCTL_DECL(_net_inet6_icmp6);
 2578 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
 2579         CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
 2580         NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
 2581         "NDP default router list");
 2582 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
 2583         CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
 2584         NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
 2585         "NDP prefix list");
 2586 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
 2587         CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
 2588 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
 2589         CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
 2590 
 2591 static int
 2592 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
 2593 {
 2594         struct in6_defrouter d;
 2595         struct nd_defrouter *dr;
 2596         int error;
 2597 
 2598         if (req->newptr != NULL)
 2599                 return (EPERM);
 2600 
 2601         error = sysctl_wire_old_buffer(req, 0);
 2602         if (error != 0)
 2603                 return (error);
 2604 
 2605         bzero(&d, sizeof(d));
 2606         d.rtaddr.sin6_family = AF_INET6;
 2607         d.rtaddr.sin6_len = sizeof(d.rtaddr);
 2608 
 2609         ND6_RLOCK();
 2610         TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
 2611                 d.rtaddr.sin6_addr = dr->rtaddr;
 2612                 error = sa6_recoverscope(&d.rtaddr);
 2613                 if (error != 0)
 2614                         break;
 2615                 d.flags = dr->raflags;
 2616                 d.rtlifetime = dr->rtlifetime;
 2617                 d.expire = dr->expire + (time_second - time_uptime);
 2618                 d.if_index = dr->ifp->if_index;
 2619                 error = SYSCTL_OUT(req, &d, sizeof(d));
 2620                 if (error != 0)
 2621                         break;
 2622         }
 2623         ND6_RUNLOCK();
 2624         return (error);
 2625 }
 2626 
 2627 static int
 2628 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
 2629 {
 2630         struct in6_prefix p;
 2631         struct sockaddr_in6 s6;
 2632         struct nd_prefix *pr;
 2633         struct nd_pfxrouter *pfr;
 2634         time_t maxexpire;
 2635         int error;
 2636         char ip6buf[INET6_ADDRSTRLEN];
 2637 
 2638         if (req->newptr)
 2639                 return (EPERM);
 2640 
 2641         error = sysctl_wire_old_buffer(req, 0);
 2642         if (error != 0)
 2643                 return (error);
 2644 
 2645         bzero(&p, sizeof(p));
 2646         p.origin = PR_ORIG_RA;
 2647         bzero(&s6, sizeof(s6));
 2648         s6.sin6_family = AF_INET6;
 2649         s6.sin6_len = sizeof(s6);
 2650 
 2651         ND6_RLOCK();
 2652         LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
 2653                 p.prefix = pr->ndpr_prefix;
 2654                 if (sa6_recoverscope(&p.prefix)) {
 2655                         log(LOG_ERR, "scope error in prefix list (%s)\n",
 2656                             ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
 2657                         /* XXX: press on... */
 2658                 }
 2659                 p.raflags = pr->ndpr_raf;
 2660                 p.prefixlen = pr->ndpr_plen;
 2661                 p.vltime = pr->ndpr_vltime;
 2662                 p.pltime = pr->ndpr_pltime;
 2663                 p.if_index = pr->ndpr_ifp->if_index;
 2664                 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
 2665                         p.expire = 0;
 2666                 else {
 2667                         /* XXX: we assume time_t is signed. */
 2668                         maxexpire = (-1) &
 2669                             ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
 2670                         if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
 2671                                 p.expire = pr->ndpr_lastupdate +
 2672                                     pr->ndpr_vltime +
 2673                                     (time_second - time_uptime);
 2674                         else
 2675                                 p.expire = maxexpire;
 2676                 }
 2677                 p.refcnt = pr->ndpr_refcnt;
 2678                 p.flags = pr->ndpr_stateflags;
 2679                 p.advrtrs = 0;
 2680                 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
 2681                         p.advrtrs++;
 2682                 error = SYSCTL_OUT(req, &p, sizeof(p));
 2683                 if (error != 0)
 2684                         break;
 2685                 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
 2686                         s6.sin6_addr = pfr->router->rtaddr;
 2687                         if (sa6_recoverscope(&s6))
 2688                                 log(LOG_ERR,
 2689                                     "scope error in prefix list (%s)\n",
 2690                                     ip6_sprintf(ip6buf, &pfr->router->rtaddr));
 2691                         error = SYSCTL_OUT(req, &s6, sizeof(s6));
 2692                         if (error != 0)
 2693                                 break;
 2694                 }
 2695         }
 2696         ND6_RUNLOCK();
 2697         return (error);
 2698 }

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