The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/nd6_nbr.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_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
   30  */
   31 
   32 #include <sys/cdefs.h>
   33 __FBSDID("$FreeBSD: releng/8.4/sys/netinet6/nd6_nbr.c 233047 2012-03-16 21:28:29Z jhb $");
   34 
   35 #include "opt_inet.h"
   36 #include "opt_inet6.h"
   37 #include "opt_ipsec.h"
   38 #include "opt_mpath.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/malloc.h>
   43 #include <sys/lock.h>
   44 #include <sys/rwlock.h>
   45 #include <sys/mbuf.h>
   46 #include <sys/socket.h>
   47 #include <sys/sockio.h>
   48 #include <sys/time.h>
   49 #include <sys/kernel.h>
   50 #include <sys/errno.h>
   51 #include <sys/syslog.h>
   52 #include <sys/queue.h>
   53 #include <sys/callout.h>
   54 
   55 #include <net/if.h>
   56 #include <net/if_types.h>
   57 #include <net/if_dl.h>
   58 #include <net/if_var.h>
   59 #include <net/route.h>
   60 #ifdef RADIX_MPATH
   61 #include <net/radix_mpath.h>
   62 #endif
   63 
   64 #include <netinet/in.h>
   65 #include <netinet/in_var.h>
   66 #include <net/if_llatbl.h>
   67 #define L3_ADDR_SIN6(le)        ((struct sockaddr_in6 *) L3_ADDR(le))
   68 #include <netinet6/in6_var.h>
   69 #include <netinet6/in6_ifattach.h>
   70 #include <netinet/ip6.h>
   71 #include <netinet6/ip6_var.h>
   72 #include <netinet6/scope6_var.h>
   73 #include <netinet6/nd6.h>
   74 #include <netinet/icmp6.h>
   75 #include <netinet/ip_carp.h>
   76 
   77 #define SDL(s) ((struct sockaddr_dl *)s)
   78 
   79 struct dadq;
   80 static struct dadq *nd6_dad_find(struct ifaddr *);
   81 static void nd6_dad_starttimer(struct dadq *, int);
   82 static void nd6_dad_stoptimer(struct dadq *);
   83 static void nd6_dad_timer(struct dadq *);
   84 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
   85 static void nd6_dad_ns_input(struct ifaddr *);
   86 static void nd6_dad_na_input(struct ifaddr *);
   87 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
   88     const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
   89 
   90 VNET_DEFINE(int, dad_ignore_ns) = 0;    /* ignore NS in DAD - specwise incorrect*/
   91 VNET_DEFINE(int, dad_maxtry) = 15;      /* max # of *tries* to transmit DAD packet */
   92 #define V_dad_ignore_ns                 VNET(dad_ignore_ns)
   93 #define V_dad_maxtry                    VNET(dad_maxtry)
   94 
   95 /*
   96  * Input a Neighbor Solicitation Message.
   97  *
   98  * Based on RFC 2461
   99  * Based on RFC 2462 (duplicate address detection)
  100  */
  101 void
  102 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
  103 {
  104         struct ifnet *ifp = m->m_pkthdr.rcvif;
  105         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  106         struct nd_neighbor_solicit *nd_ns;
  107         struct in6_addr saddr6 = ip6->ip6_src;
  108         struct in6_addr daddr6 = ip6->ip6_dst;
  109         struct in6_addr taddr6;
  110         struct in6_addr myaddr6;
  111         char *lladdr = NULL;
  112         struct ifaddr *ifa = NULL;
  113         int lladdrlen = 0;
  114         int anycast = 0, proxy = 0, tentative = 0;
  115         int tlladdr;
  116         union nd_opts ndopts;
  117         struct sockaddr_dl proxydl;
  118         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  119 
  120 #ifndef PULLDOWN_TEST
  121         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  122         nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
  123 #else
  124         IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
  125         if (nd_ns == NULL) {
  126                 ICMP6STAT_INC(icp6s_tooshort);
  127                 return;
  128         }
  129 #endif
  130         ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
  131         taddr6 = nd_ns->nd_ns_target;
  132         if (in6_setscope(&taddr6, ifp, NULL) != 0)
  133                 goto bad;
  134 
  135         if (ip6->ip6_hlim != 255) {
  136                 nd6log((LOG_ERR,
  137                     "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
  138                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  139                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  140                 goto bad;
  141         }
  142 
  143         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
  144                 /* dst has to be a solicited node multicast address. */
  145                 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
  146                     /* don't check ifindex portion */
  147                     daddr6.s6_addr32[1] == 0 &&
  148                     daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
  149                     daddr6.s6_addr8[12] == 0xff) {
  150                         ; /* good */
  151                 } else {
  152                         nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
  153                             "(wrong ip6 dst)\n"));
  154                         goto bad;
  155                 }
  156         } else if (!V_nd6_onlink_ns_rfc4861) {
  157                 struct sockaddr_in6 src_sa6;
  158 
  159                 /*
  160                  * According to recent IETF discussions, it is not a good idea
  161                  * to accept a NS from an address which would not be deemed
  162                  * to be a neighbor otherwise.  This point is expected to be
  163                  * clarified in future revisions of the specification.
  164                  */
  165                 bzero(&src_sa6, sizeof(src_sa6));
  166                 src_sa6.sin6_family = AF_INET6;
  167                 src_sa6.sin6_len = sizeof(src_sa6);
  168                 src_sa6.sin6_addr = saddr6;
  169                 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
  170                         nd6log((LOG_INFO, "nd6_ns_input: "
  171                                 "NS packet from non-neighbor\n"));
  172                         goto bad;
  173                 }
  174         }
  175 
  176         if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
  177                 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
  178                 goto bad;
  179         }
  180 
  181         icmp6len -= sizeof(*nd_ns);
  182         nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
  183         if (nd6_options(&ndopts) < 0) {
  184                 nd6log((LOG_INFO,
  185                     "nd6_ns_input: invalid ND option, ignored\n"));
  186                 /* nd6_options have incremented stats */
  187                 goto freeit;
  188         }
  189 
  190         if (ndopts.nd_opts_src_lladdr) {
  191                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  192                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  193         }
  194 
  195         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
  196                 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
  197                     "(link-layer address option)\n"));
  198                 goto bad;
  199         }
  200 
  201         /*
  202          * Attaching target link-layer address to the NA?
  203          * (RFC 2461 7.2.4)
  204          *
  205          * NS IP dst is unicast/anycast                 MUST NOT add
  206          * NS IP dst is solicited-node multicast        MUST add
  207          *
  208          * In implementation, we add target link-layer address by default.
  209          * We do not add one in MUST NOT cases.
  210          */
  211         if (!IN6_IS_ADDR_MULTICAST(&daddr6))
  212                 tlladdr = 0;
  213         else
  214                 tlladdr = 1;
  215 
  216         /*
  217          * Target address (taddr6) must be either:
  218          * (1) Valid unicast/anycast address for my receiving interface,
  219          * (2) Unicast address for which I'm offering proxy service, or
  220          * (3) "tentative" address on which DAD is being performed.
  221          */
  222         /* (1) and (3) check. */
  223         if (ifp->if_carp)
  224                 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
  225         if (ifa == NULL)
  226                 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
  227 
  228         /* (2) check. */
  229         if (ifa == NULL) {
  230                 struct rtentry *rt;
  231                 struct sockaddr_in6 tsin6;
  232                 int need_proxy;
  233 #ifdef RADIX_MPATH
  234                 struct route_in6 ro;
  235 #endif
  236 
  237                 bzero(&tsin6, sizeof tsin6);
  238                 tsin6.sin6_len = sizeof(struct sockaddr_in6);
  239                 tsin6.sin6_family = AF_INET6;
  240                 tsin6.sin6_addr = taddr6;
  241 
  242                 /* Always use the default FIB. */
  243 #ifdef RADIX_MPATH
  244                 bzero(&ro, sizeof(ro));
  245                 ro.ro_dst = tsin6;
  246                 rtalloc_mpath_fib((struct route *)&ro, RTF_ANNOUNCE,
  247                     RT_DEFAULT_FIB);
  248                 rt = ro.ro_rt;
  249 #else
  250                 rt = in6_rtalloc1((struct sockaddr *)&tsin6, 0, 0,
  251                     RT_DEFAULT_FIB);
  252 #endif
  253                 need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
  254                     rt->rt_gateway->sa_family == AF_LINK);
  255                 if (rt != NULL) {
  256                         /*
  257                          * Make a copy while we can be sure that rt_gateway
  258                          * is still stable before unlocking to avoid lock
  259                          * order problems.  proxydl will only be used if
  260                          * proxy will be set in the next block.
  261                          */
  262                         if (need_proxy)
  263                                 proxydl = *SDL(rt->rt_gateway);
  264                         RTFREE_LOCKED(rt);
  265                 }
  266                 if (need_proxy) {
  267                         /*
  268                          * proxy NDP for single entry
  269                          */
  270                         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
  271                                 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
  272                         if (ifa)
  273                                 proxy = 1;
  274                 }
  275         }
  276         if (ifa == NULL) {
  277                 /*
  278                  * We've got an NS packet, and we don't have that adddress
  279                  * assigned for us.  We MUST silently ignore it.
  280                  * See RFC2461 7.2.3.
  281                  */
  282                 goto freeit;
  283         }
  284         myaddr6 = *IFA_IN6(ifa);
  285         anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
  286         tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
  287         if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
  288                 goto freeit;
  289 
  290         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  291                 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
  292                     "(if %d, NS packet %d)\n",
  293                     ip6_sprintf(ip6bufs, &taddr6),
  294                     ifp->if_addrlen, lladdrlen - 2));
  295                 goto bad;
  296         }
  297 
  298         if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
  299                 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
  300                     ip6_sprintf(ip6bufs, &saddr6)));
  301                 goto freeit;
  302         }
  303 
  304         /*
  305          * We have neighbor solicitation packet, with target address equals to
  306          * one of my tentative address.
  307          *
  308          * src addr     how to process?
  309          * ---          ---
  310          * multicast    of course, invalid (rejected in ip6_input)
  311          * unicast      somebody is doing address resolution -> ignore
  312          * unspec       dup address detection
  313          *
  314          * The processing is defined in RFC 2462.
  315          */
  316         if (tentative) {
  317                 /*
  318                  * If source address is unspecified address, it is for
  319                  * duplicate address detection.
  320                  *
  321                  * If not, the packet is for addess resolution;
  322                  * silently ignore it.
  323                  */
  324                 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
  325                         nd6_dad_ns_input(ifa);
  326 
  327                 goto freeit;
  328         }
  329 
  330         /*
  331          * If the source address is unspecified address, entries must not
  332          * be created or updated.
  333          * It looks that sender is performing DAD.  Output NA toward
  334          * all-node multicast address, to tell the sender that I'm using
  335          * the address.
  336          * S bit ("solicited") must be zero.
  337          */
  338         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
  339                 struct in6_addr in6_all;
  340 
  341                 in6_all = in6addr_linklocal_allnodes;
  342                 if (in6_setscope(&in6_all, ifp, NULL) != 0)
  343                         goto bad;
  344                 nd6_na_output_fib(ifp, &in6_all, &taddr6,
  345                     ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  346                     (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0),
  347                     tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
  348                     M_GETFIB(m));
  349                 goto freeit;
  350         }
  351 
  352         nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
  353             ND_NEIGHBOR_SOLICIT, 0);
  354 
  355         nd6_na_output_fib(ifp, &saddr6, &taddr6,
  356             ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  357             (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
  358             tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
  359  freeit:
  360         if (ifa != NULL)
  361                 ifa_free(ifa);
  362         m_freem(m);
  363         return;
  364 
  365  bad:
  366         nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
  367                 ip6_sprintf(ip6bufs, &saddr6)));
  368         nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
  369                 ip6_sprintf(ip6bufs, &daddr6)));
  370         nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
  371                 ip6_sprintf(ip6bufs, &taddr6)));
  372         ICMP6STAT_INC(icp6s_badns);
  373         if (ifa != NULL)
  374                 ifa_free(ifa);
  375         m_freem(m);
  376 }
  377 
  378 /*
  379  * Output a Neighbor Solicitation Message. Caller specifies:
  380  *      - ICMP6 header source IP6 address
  381  *      - ND6 header target IP6 address
  382  *      - ND6 header source datalink address
  383  *
  384  * Based on RFC 2461
  385  * Based on RFC 2462 (duplicate address detection)
  386  *
  387  *   ln - for source address determination
  388  *  dad - duplicate address detection
  389  */
  390 void
  391 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 
  392     const struct in6_addr *taddr6, struct llentry *ln, int dad)
  393 {
  394         struct mbuf *m;
  395         struct ip6_hdr *ip6;
  396         struct nd_neighbor_solicit *nd_ns;
  397         struct ip6_moptions im6o;
  398         int icmp6len;
  399         int maxlen;
  400         caddr_t mac;
  401         struct route_in6 ro;
  402 
  403         if (IN6_IS_ADDR_MULTICAST(taddr6))
  404                 return;
  405 
  406         /* estimate the size of message */
  407         maxlen = sizeof(*ip6) + sizeof(*nd_ns);
  408         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  409         if (max_linkhdr + maxlen >= MCLBYTES) {
  410 #ifdef DIAGNOSTIC
  411                 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
  412                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  413 #endif
  414                 return;
  415         }
  416 
  417         MGETHDR(m, M_DONTWAIT, MT_DATA);
  418         if (m && max_linkhdr + maxlen >= MHLEN) {
  419                 MCLGET(m, M_DONTWAIT);
  420                 if ((m->m_flags & M_EXT) == 0) {
  421                         m_free(m);
  422                         m = NULL;
  423                 }
  424         }
  425         if (m == NULL)
  426                 return;
  427         m->m_pkthdr.rcvif = NULL;
  428 
  429         bzero(&ro, sizeof(ro));
  430 
  431         if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
  432                 m->m_flags |= M_MCAST;
  433                 im6o.im6o_multicast_ifp = ifp;
  434                 im6o.im6o_multicast_hlim = 255;
  435                 im6o.im6o_multicast_loop = 0;
  436         }
  437 
  438         icmp6len = sizeof(*nd_ns);
  439         m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
  440         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  441 
  442         /* fill neighbor solicitation packet */
  443         ip6 = mtod(m, struct ip6_hdr *);
  444         ip6->ip6_flow = 0;
  445         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  446         ip6->ip6_vfc |= IPV6_VERSION;
  447         /* ip6->ip6_plen will be set later */
  448         ip6->ip6_nxt = IPPROTO_ICMPV6;
  449         ip6->ip6_hlim = 255;
  450         if (daddr6)
  451                 ip6->ip6_dst = *daddr6;
  452         else {
  453                 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  454                 ip6->ip6_dst.s6_addr16[1] = 0;
  455                 ip6->ip6_dst.s6_addr32[1] = 0;
  456                 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
  457                 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
  458                 ip6->ip6_dst.s6_addr8[12] = 0xff;
  459                 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
  460                         goto bad;
  461         }
  462         if (!dad) {
  463                 struct ifaddr *ifa;
  464 
  465                 /*
  466                  * RFC2461 7.2.2:
  467                  * "If the source address of the packet prompting the
  468                  * solicitation is the same as one of the addresses assigned
  469                  * to the outgoing interface, that address SHOULD be placed
  470                  * in the IP Source Address of the outgoing solicitation.
  471                  * Otherwise, any one of the addresses assigned to the
  472                  * interface should be used."
  473                  *
  474                  * We use the source address for the prompting packet
  475                  * (saddr6), if:
  476                  * - saddr6 is given from the caller (by giving "ln"), and
  477                  * - saddr6 belongs to the outgoing interface.
  478                  * Otherwise, we perform the source address selection as usual.
  479                  */
  480                 struct in6_addr *hsrc;
  481 
  482                 hsrc = NULL;
  483                 if (ln != NULL) {
  484                         LLE_RLOCK(ln);
  485                         if (ln->la_hold != NULL) {
  486                                 struct ip6_hdr *hip6;           /* hold ip6 */
  487 
  488                                 /*
  489                                  * assuming every packet in la_hold has the same IP
  490                                  * header
  491                                  */
  492                                 hip6 = mtod(ln->la_hold, struct ip6_hdr *);
  493                                 /* XXX pullup? */
  494                                 if (sizeof(*hip6) < ln->la_hold->m_len) {
  495                                         ip6->ip6_src = hip6->ip6_src;
  496                                         hsrc = &hip6->ip6_src;
  497                                 }
  498                         }
  499                         LLE_RUNLOCK(ln);
  500                 }
  501                 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
  502                     hsrc)) != NULL) {
  503                         /* ip6_src set already. */
  504                         ifa_free(ifa);
  505                 } else {
  506                         int error;
  507                         struct sockaddr_in6 dst_sa;
  508                         struct in6_addr src_in;
  509                         struct ifnet *oifp;
  510 
  511                         bzero(&dst_sa, sizeof(dst_sa));
  512                         dst_sa.sin6_family = AF_INET6;
  513                         dst_sa.sin6_len = sizeof(dst_sa);
  514                         dst_sa.sin6_addr = ip6->ip6_dst;
  515 
  516                         oifp = ifp;
  517                         error = in6_selectsrc(&dst_sa, NULL,
  518                             NULL, &ro, NULL, &oifp, &src_in);
  519                         if (error) {
  520                                 char ip6buf[INET6_ADDRSTRLEN];
  521                                 nd6log((LOG_DEBUG,
  522                                     "nd6_ns_output: source can't be "
  523                                     "determined: dst=%s, error=%d\n",
  524                                     ip6_sprintf(ip6buf, &dst_sa.sin6_addr),
  525                                     error));
  526                                 goto bad;
  527                         }
  528                         ip6->ip6_src = src_in;
  529                 }
  530         } else {
  531                 /*
  532                  * Source address for DAD packet must always be IPv6
  533                  * unspecified address. (0::0)
  534                  * We actually don't have to 0-clear the address (we did it
  535                  * above), but we do so here explicitly to make the intention
  536                  * clearer.
  537                  */
  538                 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
  539         }
  540         nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
  541         nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
  542         nd_ns->nd_ns_code = 0;
  543         nd_ns->nd_ns_reserved = 0;
  544         nd_ns->nd_ns_target = *taddr6;
  545         in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
  546 
  547         /*
  548          * Add source link-layer address option.
  549          *
  550          *                              spec            implementation
  551          *                              ---             ---
  552          * DAD packet                   MUST NOT        do not add the option
  553          * there's no link layer address:
  554          *                              impossible      do not add the option
  555          * there's link layer address:
  556          *      Multicast NS            MUST add one    add the option
  557          *      Unicast NS              SHOULD add one  add the option
  558          */
  559         if (!dad && (mac = nd6_ifptomac(ifp))) {
  560                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
  561                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
  562                 /* 8 byte alignments... */
  563                 optlen = (optlen + 7) & ~7;
  564 
  565                 m->m_pkthdr.len += optlen;
  566                 m->m_len += optlen;
  567                 icmp6len += optlen;
  568                 bzero((caddr_t)nd_opt, optlen);
  569                 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
  570                 nd_opt->nd_opt_len = optlen >> 3;
  571                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
  572         }
  573 
  574         ip6->ip6_plen = htons((u_short)icmp6len);
  575         nd_ns->nd_ns_cksum = 0;
  576         nd_ns->nd_ns_cksum =
  577             in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
  578 
  579         ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
  580         icmp6_ifstat_inc(ifp, ifs6_out_msg);
  581         icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
  582         ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
  583 
  584         if (ro.ro_rt) {         /* we don't cache this route. */
  585                 RTFREE(ro.ro_rt);
  586         }
  587         return;
  588 
  589   bad:
  590         if (ro.ro_rt) {
  591                 RTFREE(ro.ro_rt);
  592         }
  593         m_freem(m);
  594         return;
  595 }
  596 
  597 /*
  598  * Neighbor advertisement input handling.
  599  *
  600  * Based on RFC 2461
  601  * Based on RFC 2462 (duplicate address detection)
  602  *
  603  * the following items are not implemented yet:
  604  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  605  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  606  */
  607 void
  608 nd6_na_input(struct mbuf *m, int off, int icmp6len)
  609 {
  610         struct ifnet *ifp = m->m_pkthdr.rcvif;
  611         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  612         struct nd_neighbor_advert *nd_na;
  613         struct in6_addr daddr6 = ip6->ip6_dst;
  614         struct in6_addr taddr6;
  615         int flags;
  616         int is_router;
  617         int is_solicited;
  618         int is_override;
  619         char *lladdr = NULL;
  620         int lladdrlen = 0;
  621         int checklink = 0;
  622         struct ifaddr *ifa;
  623         struct llentry *ln = NULL;
  624         union nd_opts ndopts;
  625         struct mbuf *chain = NULL;
  626         struct sockaddr_in6 sin6;
  627         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  628 
  629         if (ip6->ip6_hlim != 255) {
  630                 nd6log((LOG_ERR,
  631                     "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
  632                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  633                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  634                 goto bad;
  635         }
  636 
  637 #ifndef PULLDOWN_TEST
  638         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  639         nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
  640 #else
  641         IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
  642         if (nd_na == NULL) {
  643                 ICMP6STAT_INC(icp6s_tooshort);
  644                 return;
  645         }
  646 #endif
  647 
  648         flags = nd_na->nd_na_flags_reserved;
  649         is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
  650         is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
  651         is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
  652 
  653         taddr6 = nd_na->nd_na_target;
  654         if (in6_setscope(&taddr6, ifp, NULL))
  655                 goto bad;       /* XXX: impossible */
  656 
  657         if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
  658                 nd6log((LOG_ERR,
  659                     "nd6_na_input: invalid target address %s\n",
  660                     ip6_sprintf(ip6bufs, &taddr6)));
  661                 goto bad;
  662         }
  663         if (IN6_IS_ADDR_MULTICAST(&daddr6))
  664                 if (is_solicited) {
  665                         nd6log((LOG_ERR,
  666                             "nd6_na_input: a solicited adv is multicasted\n"));
  667                         goto bad;
  668                 }
  669 
  670         icmp6len -= sizeof(*nd_na);
  671         nd6_option_init(nd_na + 1, icmp6len, &ndopts);
  672         if (nd6_options(&ndopts) < 0) {
  673                 nd6log((LOG_INFO,
  674                     "nd6_na_input: invalid ND option, ignored\n"));
  675                 /* nd6_options have incremented stats */
  676                 goto freeit;
  677         }
  678 
  679         if (ndopts.nd_opts_tgt_lladdr) {
  680                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
  681                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
  682         }
  683 
  684         ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
  685 
  686         /*
  687          * Target address matches one of my interface address.
  688          *
  689          * If my address is tentative, this means that there's somebody
  690          * already using the same address as mine.  This indicates DAD failure.
  691          * This is defined in RFC 2462.
  692          *
  693          * Otherwise, process as defined in RFC 2461.
  694          */
  695         if (ifa
  696          && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
  697                 ifa_free(ifa);
  698                 nd6_dad_na_input(ifa);
  699                 goto freeit;
  700         }
  701 
  702         /* Just for safety, maybe unnecessary. */
  703         if (ifa) {
  704                 ifa_free(ifa);
  705                 log(LOG_ERR,
  706                     "nd6_na_input: duplicate IP6 address %s\n",
  707                     ip6_sprintf(ip6bufs, &taddr6));
  708                 goto freeit;
  709         }
  710 
  711         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  712                 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
  713                     "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
  714                     ifp->if_addrlen, lladdrlen - 2));
  715                 goto bad;
  716         }
  717 
  718         /*
  719          * If no neighbor cache entry is found, NA SHOULD silently be
  720          * discarded.
  721          */
  722         IF_AFDATA_LOCK(ifp);
  723         ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
  724         IF_AFDATA_UNLOCK(ifp);
  725         if (ln == NULL) {
  726                 goto freeit;
  727         }
  728 
  729         if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
  730                 /*
  731                  * If the link-layer has address, and no lladdr option came,
  732                  * discard the packet.
  733                  */
  734                 if (ifp->if_addrlen && lladdr == NULL) {
  735                         goto freeit;
  736                 }
  737 
  738                 /*
  739                  * Record link-layer address, and update the state.
  740                  */
  741                 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
  742                 ln->la_flags |= LLE_VALID;
  743                 if (is_solicited) {
  744                         ln->ln_state = ND6_LLINFO_REACHABLE;
  745                         ln->ln_byhint = 0;
  746                         if (!ND6_LLINFO_PERMANENT(ln)) {
  747                                 nd6_llinfo_settimer_locked(ln,
  748                                     (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz);
  749                         }
  750                 } else {
  751                         ln->ln_state = ND6_LLINFO_STALE;
  752                         nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
  753                 }
  754                 if ((ln->ln_router = is_router) != 0) {
  755                         /*
  756                          * This means a router's state has changed from
  757                          * non-reachable to probably reachable, and might
  758                          * affect the status of associated prefixes..
  759                          */
  760                         checklink = 1;
  761                 }
  762         } else {
  763                 int llchange;
  764 
  765                 /*
  766                  * Check if the link-layer address has changed or not.
  767                  */
  768                 if (lladdr == NULL)
  769                         llchange = 0;
  770                 else {
  771                         if (ln->la_flags & LLE_VALID) {
  772                                 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen))
  773                                         llchange = 1;
  774                                 else
  775                                         llchange = 0;
  776                         } else
  777                                 llchange = 1;
  778                 }
  779 
  780                 /*
  781                  * This is VERY complex.  Look at it with care.
  782                  *
  783                  * override solicit lladdr llchange     action
  784                  *                                      (L: record lladdr)
  785                  *
  786                  *      0       0       n       --      (2c)
  787                  *      0       0       y       n       (2b) L
  788                  *      0       0       y       y       (1)    REACHABLE->STALE
  789                  *      0       1       n       --      (2c)   *->REACHABLE
  790                  *      0       1       y       n       (2b) L *->REACHABLE
  791                  *      0       1       y       y       (1)    REACHABLE->STALE
  792                  *      1       0       n       --      (2a)
  793                  *      1       0       y       n       (2a) L
  794                  *      1       0       y       y       (2a) L *->STALE
  795                  *      1       1       n       --      (2a)   *->REACHABLE
  796                  *      1       1       y       n       (2a) L *->REACHABLE
  797                  *      1       1       y       y       (2a) L *->REACHABLE
  798                  */
  799                 if (!is_override && (lladdr != NULL && llchange)) {  /* (1) */
  800                         /*
  801                          * If state is REACHABLE, make it STALE.
  802                          * no other updates should be done.
  803                          */
  804                         if (ln->ln_state == ND6_LLINFO_REACHABLE) {
  805                                 ln->ln_state = ND6_LLINFO_STALE;
  806                                 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
  807                         }
  808                         goto freeit;
  809                 } else if (is_override                             /* (2a) */
  810                         || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
  811                         || lladdr == NULL) {                       /* (2c) */
  812                         /*
  813                          * Update link-local address, if any.
  814                          */
  815                         if (lladdr != NULL) {
  816                                 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
  817                                 ln->la_flags |= LLE_VALID;
  818                         }
  819 
  820                         /*
  821                          * If solicited, make the state REACHABLE.
  822                          * If not solicited and the link-layer address was
  823                          * changed, make it STALE.
  824                          */
  825                         if (is_solicited) {
  826                                 ln->ln_state = ND6_LLINFO_REACHABLE;
  827                                 ln->ln_byhint = 0;
  828                                 if (!ND6_LLINFO_PERMANENT(ln)) {
  829                                         nd6_llinfo_settimer_locked(ln,
  830                                             (long)ND_IFINFO(ifp)->reachable * hz);
  831                                 }
  832                         } else {
  833                                 if (lladdr != NULL && llchange) {
  834                                         ln->ln_state = ND6_LLINFO_STALE;
  835                                         nd6_llinfo_settimer_locked(ln,
  836                                             (long)V_nd6_gctimer * hz);
  837                                 }
  838                         }
  839                 }
  840 
  841                 if (ln->ln_router && !is_router) {
  842                         /*
  843                          * The peer dropped the router flag.
  844                          * Remove the sender from the Default Router List and
  845                          * update the Destination Cache entries.
  846                          */
  847                         struct nd_defrouter *dr;
  848                         struct in6_addr *in6;
  849 
  850                         in6 = &L3_ADDR_SIN6(ln)->sin6_addr;
  851 
  852                         /*
  853                          * Lock to protect the default router list.
  854                          * XXX: this might be unnecessary, since this function
  855                          * is only called under the network software interrupt
  856                          * context.  However, we keep it just for safety.
  857                          */
  858                         dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp);
  859                         if (dr)
  860                                 defrtrlist_del(dr);
  861                         else if (!V_ip6_forwarding) {
  862                                 /*
  863                                  * Even if the neighbor is not in the default
  864                                  * router list, the neighbor may be used
  865                                  * as a next hop for some destinations
  866                                  * (e.g. redirect case). So we must
  867                                  * call rt6_flush explicitly.
  868                                  */
  869                                 rt6_flush(&ip6->ip6_src, ifp);
  870                         }
  871                 }
  872                 ln->ln_router = is_router;
  873         }
  874         /* XXX - QL
  875          *  Does this matter?
  876          *  rt->rt_flags &= ~RTF_REJECT;
  877          */
  878         ln->la_asked = 0;
  879         if (ln->la_hold) {
  880                 struct mbuf *m_hold, *m_hold_next;
  881 
  882                 /*
  883                  * reset the la_hold in advance, to explicitly
  884                  * prevent a la_hold lookup in nd6_output()
  885                  * (wouldn't happen, though...)
  886                  */
  887                 for (m_hold = ln->la_hold, ln->la_hold = NULL;
  888                     m_hold; m_hold = m_hold_next) {
  889                         m_hold_next = m_hold->m_nextpkt;
  890                         m_hold->m_nextpkt = NULL;
  891                         /*
  892                          * we assume ifp is not a loopback here, so just set
  893                          * the 2nd argument as the 1st one.
  894                          */
  895                         nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
  896                 }
  897         }
  898  freeit:
  899         if (ln != NULL) {
  900                 if (chain)
  901                         memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
  902                 LLE_WUNLOCK(ln);
  903 
  904                 if (chain)
  905                         nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
  906         }
  907         if (checklink)
  908                 pfxlist_onlink_check();
  909 
  910         m_freem(m);
  911         return;
  912 
  913  bad:
  914         if (ln != NULL)
  915                 LLE_WUNLOCK(ln);
  916 
  917         ICMP6STAT_INC(icp6s_badna);
  918         m_freem(m);
  919 }
  920 
  921 /*
  922  * Neighbor advertisement output handling.
  923  *
  924  * Based on RFC 2461
  925  *
  926  * the following items are not implemented yet:
  927  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  928  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  929  *
  930  * tlladdr - 1 if include target link-layer address
  931  * sdl0 - sockaddr_dl (= proxy NA) or NULL
  932  */
  933 static void
  934 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
  935     const struct in6_addr *taddr6, u_long flags, int tlladdr,
  936     struct sockaddr *sdl0, u_int fibnum)
  937 {
  938         struct mbuf *m;
  939         struct ifnet *oifp;
  940         struct ip6_hdr *ip6;
  941         struct nd_neighbor_advert *nd_na;
  942         struct ip6_moptions im6o;
  943         struct in6_addr src, daddr6;
  944         struct sockaddr_in6 dst_sa;
  945         int icmp6len, maxlen, error;
  946         caddr_t mac = NULL;
  947         struct route_in6 ro;
  948 
  949         bzero(&ro, sizeof(ro));
  950 
  951         daddr6 = *daddr6_0;     /* make a local copy for modification */
  952 
  953         /* estimate the size of message */
  954         maxlen = sizeof(*ip6) + sizeof(*nd_na);
  955         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  956         if (max_linkhdr + maxlen >= MCLBYTES) {
  957 #ifdef DIAGNOSTIC
  958                 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
  959                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  960 #endif
  961                 return;
  962         }
  963 
  964         MGETHDR(m, M_DONTWAIT, MT_DATA);
  965         if (m && max_linkhdr + maxlen >= MHLEN) {
  966                 MCLGET(m, M_DONTWAIT);
  967                 if ((m->m_flags & M_EXT) == 0) {
  968                         m_free(m);
  969                         m = NULL;
  970                 }
  971         }
  972         if (m == NULL)
  973                 return;
  974         m->m_pkthdr.rcvif = NULL;
  975         M_SETFIB(m, fibnum);
  976 
  977         if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
  978                 m->m_flags |= M_MCAST;
  979                 im6o.im6o_multicast_ifp = ifp;
  980                 im6o.im6o_multicast_hlim = 255;
  981                 im6o.im6o_multicast_loop = 0;
  982         }
  983 
  984         icmp6len = sizeof(*nd_na);
  985         m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
  986         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  987 
  988         /* fill neighbor advertisement packet */
  989         ip6 = mtod(m, struct ip6_hdr *);
  990         ip6->ip6_flow = 0;
  991         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  992         ip6->ip6_vfc |= IPV6_VERSION;
  993         ip6->ip6_nxt = IPPROTO_ICMPV6;
  994         ip6->ip6_hlim = 255;
  995         if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
  996                 /* reply to DAD */
  997                 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  998                 daddr6.s6_addr16[1] = 0;
  999                 daddr6.s6_addr32[1] = 0;
 1000                 daddr6.s6_addr32[2] = 0;
 1001                 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
 1002                 if (in6_setscope(&daddr6, ifp, NULL))
 1003                         goto bad;
 1004 
 1005                 flags &= ~ND_NA_FLAG_SOLICITED;
 1006         }
 1007         ip6->ip6_dst = daddr6;
 1008         bzero(&dst_sa, sizeof(struct sockaddr_in6));
 1009         dst_sa.sin6_family = AF_INET6;
 1010         dst_sa.sin6_len = sizeof(struct sockaddr_in6);
 1011         dst_sa.sin6_addr = daddr6;
 1012 
 1013         /*
 1014          * Select a source whose scope is the same as that of the dest.
 1015          */
 1016         bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
 1017         oifp = ifp;
 1018         error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &src);
 1019         if (error) {
 1020                 char ip6buf[INET6_ADDRSTRLEN];
 1021                 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
 1022                     "determined: dst=%s, error=%d\n",
 1023                     ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error));
 1024                 goto bad;
 1025         }
 1026         ip6->ip6_src = src;
 1027         nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
 1028         nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
 1029         nd_na->nd_na_code = 0;
 1030         nd_na->nd_na_target = *taddr6;
 1031         in6_clearscope(&nd_na->nd_na_target); /* XXX */
 1032 
 1033         /*
 1034          * "tlladdr" indicates NS's condition for adding tlladdr or not.
 1035          * see nd6_ns_input() for details.
 1036          * Basically, if NS packet is sent to unicast/anycast addr,
 1037          * target lladdr option SHOULD NOT be included.
 1038          */
 1039         if (tlladdr) {
 1040                 /*
 1041                  * sdl0 != NULL indicates proxy NA.  If we do proxy, use
 1042                  * lladdr in sdl0.  If we are not proxying (sending NA for
 1043                  * my address) use lladdr configured for the interface.
 1044                  */
 1045                 if (sdl0 == NULL) {
 1046                         if (ifp->if_carp)
 1047                                 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
 1048                         if (mac == NULL)
 1049                                 mac = nd6_ifptomac(ifp);
 1050                 } else if (sdl0->sa_family == AF_LINK) {
 1051                         struct sockaddr_dl *sdl;
 1052                         sdl = (struct sockaddr_dl *)sdl0;
 1053                         if (sdl->sdl_alen == ifp->if_addrlen)
 1054                                 mac = LLADDR(sdl);
 1055                 }
 1056         }
 1057         if (tlladdr && mac) {
 1058                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
 1059                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
 1060 
 1061                 /* roundup to 8 bytes alignment! */
 1062                 optlen = (optlen + 7) & ~7;
 1063 
 1064                 m->m_pkthdr.len += optlen;
 1065                 m->m_len += optlen;
 1066                 icmp6len += optlen;
 1067                 bzero((caddr_t)nd_opt, optlen);
 1068                 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
 1069                 nd_opt->nd_opt_len = optlen >> 3;
 1070                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
 1071         } else
 1072                 flags &= ~ND_NA_FLAG_OVERRIDE;
 1073 
 1074         ip6->ip6_plen = htons((u_short)icmp6len);
 1075         nd_na->nd_na_flags_reserved = flags;
 1076         nd_na->nd_na_cksum = 0;
 1077         nd_na->nd_na_cksum =
 1078             in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
 1079 
 1080         ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL);
 1081         icmp6_ifstat_inc(ifp, ifs6_out_msg);
 1082         icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
 1083         ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
 1084 
 1085         if (ro.ro_rt) {         /* we don't cache this route. */
 1086                 RTFREE(ro.ro_rt);
 1087         }
 1088         return;
 1089 
 1090   bad:
 1091         if (ro.ro_rt) {
 1092                 RTFREE(ro.ro_rt);
 1093         }
 1094         m_freem(m);
 1095         return;
 1096 }
 1097 
 1098 #ifndef BURN_BRIDGES
 1099 void
 1100 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
 1101     const struct in6_addr *taddr6, u_long flags, int tlladdr,
 1102     struct sockaddr *sdl0)
 1103 {
 1104 
 1105         nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
 1106             RT_DEFAULT_FIB);
 1107 }
 1108 #endif
 1109 
 1110 caddr_t
 1111 nd6_ifptomac(struct ifnet *ifp)
 1112 {
 1113         switch (ifp->if_type) {
 1114         case IFT_ARCNET:
 1115         case IFT_ETHER:
 1116         case IFT_FDDI:
 1117         case IFT_IEEE1394:
 1118 #ifdef IFT_L2VLAN
 1119         case IFT_L2VLAN:
 1120 #endif
 1121 #ifdef IFT_IEEE80211
 1122         case IFT_IEEE80211:
 1123 #endif
 1124 #ifdef IFT_CARP
 1125         case IFT_CARP:
 1126 #endif
 1127         case IFT_BRIDGE:
 1128         case IFT_ISO88025:
 1129                 return IF_LLADDR(ifp);
 1130         default:
 1131                 return NULL;
 1132         }
 1133 }
 1134 
 1135 struct dadq {
 1136         TAILQ_ENTRY(dadq) dad_list;
 1137         struct ifaddr *dad_ifa;
 1138         int dad_count;          /* max NS to send */
 1139         int dad_ns_tcount;      /* # of trials to send NS */
 1140         int dad_ns_ocount;      /* NS sent so far */
 1141         int dad_ns_icount;
 1142         int dad_na_icount;
 1143         struct callout dad_timer_ch;
 1144         struct vnet *dad_vnet;
 1145 };
 1146 
 1147 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
 1148 VNET_DEFINE(int, dad_init) = 0;
 1149 #define V_dadq                          VNET(dadq)
 1150 #define V_dad_init                      VNET(dad_init)
 1151 
 1152 static struct dadq *
 1153 nd6_dad_find(struct ifaddr *ifa)
 1154 {
 1155         struct dadq *dp;
 1156 
 1157         TAILQ_FOREACH(dp, &V_dadq, dad_list)
 1158                 if (dp->dad_ifa == ifa)
 1159                         return (dp);
 1160 
 1161         return (NULL);
 1162 }
 1163 
 1164 static void
 1165 nd6_dad_starttimer(struct dadq *dp, int ticks)
 1166 {
 1167 
 1168         callout_reset(&dp->dad_timer_ch, ticks,
 1169             (void (*)(void *))nd6_dad_timer, (void *)dp);
 1170 }
 1171 
 1172 static void
 1173 nd6_dad_stoptimer(struct dadq *dp)
 1174 {
 1175 
 1176         callout_stop(&dp->dad_timer_ch);
 1177 }
 1178 
 1179 /*
 1180  * Start Duplicate Address Detection (DAD) for specified interface address.
 1181  */
 1182 void
 1183 nd6_dad_start(struct ifaddr *ifa, int delay)
 1184 {
 1185         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1186         struct dadq *dp;
 1187         char ip6buf[INET6_ADDRSTRLEN];
 1188 
 1189         if (!V_dad_init) {
 1190                 TAILQ_INIT(&V_dadq);
 1191                 V_dad_init++;
 1192         }
 1193 
 1194         /*
 1195          * If we don't need DAD, don't do it.
 1196          * There are several cases:
 1197          * - DAD is disabled (ip6_dad_count == 0)
 1198          * - the interface address is anycast
 1199          */
 1200         if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
 1201                 log(LOG_DEBUG,
 1202                         "nd6_dad_start: called with non-tentative address "
 1203                         "%s(%s)\n",
 1204                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1205                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1206                 return;
 1207         }
 1208         if (ia->ia6_flags & IN6_IFF_ANYCAST) {
 1209                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1210                 return;
 1211         }
 1212         if (!V_ip6_dad_count) {
 1213                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1214                 return;
 1215         }
 1216         if (ifa->ifa_ifp == NULL)
 1217                 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
 1218         if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
 1219                 return;
 1220         }
 1221         if (nd6_dad_find(ifa) != NULL) {
 1222                 /* DAD already in progress */
 1223                 return;
 1224         }
 1225 
 1226         dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
 1227         if (dp == NULL) {
 1228                 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
 1229                         "%s(%s)\n",
 1230                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1231                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1232                 return;
 1233         }
 1234         bzero(dp, sizeof(*dp));
 1235         callout_init(&dp->dad_timer_ch, 0);
 1236 #ifdef VIMAGE
 1237         dp->dad_vnet = curvnet;
 1238 #endif
 1239         TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list);
 1240 
 1241         nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
 1242             ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
 1243 
 1244         /*
 1245          * Send NS packet for DAD, ip6_dad_count times.
 1246          * Note that we must delay the first transmission, if this is the
 1247          * first packet to be sent from the interface after interface
 1248          * (re)initialization.
 1249          */
 1250         dp->dad_ifa = ifa;
 1251         ifa_ref(ifa);   /* just for safety */
 1252         dp->dad_count = V_ip6_dad_count;
 1253         dp->dad_ns_icount = dp->dad_na_icount = 0;
 1254         dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
 1255         if (delay == 0) {
 1256                 nd6_dad_ns_output(dp, ifa);
 1257                 nd6_dad_starttimer(dp,
 1258                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1259         } else {
 1260                 nd6_dad_starttimer(dp, delay);
 1261         }
 1262 }
 1263 
 1264 /*
 1265  * terminate DAD unconditionally.  used for address removals.
 1266  */
 1267 void
 1268 nd6_dad_stop(struct ifaddr *ifa)
 1269 {
 1270         struct dadq *dp;
 1271 
 1272         if (!V_dad_init)
 1273                 return;
 1274         dp = nd6_dad_find(ifa);
 1275         if (!dp) {
 1276                 /* DAD wasn't started yet */
 1277                 return;
 1278         }
 1279 
 1280         nd6_dad_stoptimer(dp);
 1281 
 1282         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1283         free(dp, M_IP6NDP);
 1284         dp = NULL;
 1285         ifa_free(ifa);
 1286 }
 1287 
 1288 static void
 1289 nd6_dad_timer(struct dadq *dp)
 1290 {
 1291         CURVNET_SET(dp->dad_vnet);
 1292         int s;
 1293         struct ifaddr *ifa = dp->dad_ifa;
 1294         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1295         char ip6buf[INET6_ADDRSTRLEN];
 1296 
 1297         s = splnet();           /* XXX */
 1298 
 1299         /* Sanity check */
 1300         if (ia == NULL) {
 1301                 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
 1302                 goto done;
 1303         }
 1304         if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
 1305                 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
 1306                         "%s(%s)\n",
 1307                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1308                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1309                 goto done;
 1310         }
 1311         if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
 1312                 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
 1313                         "%s(%s)\n",
 1314                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1315                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1316                 goto done;
 1317         }
 1318 
 1319         /* timeouted with IFF_{RUNNING,UP} check */
 1320         if (dp->dad_ns_tcount > V_dad_maxtry) {
 1321                 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
 1322                     if_name(ifa->ifa_ifp)));
 1323 
 1324                 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1325                 free(dp, M_IP6NDP);
 1326                 dp = NULL;
 1327                 ifa_free(ifa);
 1328                 goto done;
 1329         }
 1330 
 1331         /* Need more checks? */
 1332         if (dp->dad_ns_ocount < dp->dad_count) {
 1333                 /*
 1334                  * We have more NS to go.  Send NS packet for DAD.
 1335                  */
 1336                 nd6_dad_ns_output(dp, ifa);
 1337                 nd6_dad_starttimer(dp,
 1338                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1339         } else {
 1340                 /*
 1341                  * We have transmitted sufficient number of DAD packets.
 1342                  * See what we've got.
 1343                  */
 1344                 int duplicate;
 1345 
 1346                 duplicate = 0;
 1347 
 1348                 if (dp->dad_na_icount) {
 1349                         /*
 1350                          * the check is in nd6_dad_na_input(),
 1351                          * but just in case
 1352                          */
 1353                         duplicate++;
 1354                 }
 1355 
 1356                 if (dp->dad_ns_icount) {
 1357                         /* We've seen NS, means DAD has failed. */
 1358                         duplicate++;
 1359                 }
 1360 
 1361                 if (duplicate) {
 1362                         /* (*dp) will be freed in nd6_dad_duplicated() */
 1363                         dp = NULL;
 1364                         nd6_dad_duplicated(ifa);
 1365                 } else {
 1366                         /*
 1367                          * We are done with DAD.  No NA came, no NS came.
 1368                          * No duplicate address found.
 1369                          */
 1370                         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1371 
 1372                         nd6log((LOG_DEBUG,
 1373                             "%s: DAD complete for %s - no duplicates found\n",
 1374                             if_name(ifa->ifa_ifp),
 1375                             ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
 1376 
 1377                         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1378                         free(dp, M_IP6NDP);
 1379                         dp = NULL;
 1380                         ifa_free(ifa);
 1381                 }
 1382         }
 1383 
 1384 done:
 1385         splx(s);
 1386         CURVNET_RESTORE();
 1387 }
 1388 
 1389 void
 1390 nd6_dad_duplicated(struct ifaddr *ifa)
 1391 {
 1392         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1393         struct ifnet *ifp;
 1394         struct dadq *dp;
 1395         char ip6buf[INET6_ADDRSTRLEN];
 1396 
 1397         dp = nd6_dad_find(ifa);
 1398         if (dp == NULL) {
 1399                 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
 1400                 return;
 1401         }
 1402 
 1403         log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
 1404             "NS in/out=%d/%d, NA in=%d\n",
 1405             if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1406             dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
 1407 
 1408         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1409         ia->ia6_flags |= IN6_IFF_DUPLICATED;
 1410 
 1411         /* We are done with DAD, with duplicate address found. (failure) */
 1412         nd6_dad_stoptimer(dp);
 1413 
 1414         ifp = ifa->ifa_ifp;
 1415         log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
 1416             if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
 1417         log(LOG_ERR, "%s: manual intervention required\n",
 1418             if_name(ifp));
 1419 
 1420         /*
 1421          * If the address is a link-local address formed from an interface
 1422          * identifier based on the hardware address which is supposed to be
 1423          * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
 1424          * operation on the interface SHOULD be disabled.
 1425          * [rfc2462bis-03 Section 5.4.5]
 1426          */
 1427         if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
 1428                 struct in6_addr in6;
 1429 
 1430                 /*
 1431                  * To avoid over-reaction, we only apply this logic when we are
 1432                  * very sure that hardware addresses are supposed to be unique.
 1433                  */
 1434                 switch (ifp->if_type) {
 1435                 case IFT_ETHER:
 1436                 case IFT_FDDI:
 1437                 case IFT_ATM:
 1438                 case IFT_IEEE1394:
 1439 #ifdef IFT_IEEE80211
 1440                 case IFT_IEEE80211:
 1441 #endif
 1442                         in6 = ia->ia_addr.sin6_addr;
 1443                         if (in6_get_hw_ifid(ifp, &in6) == 0 &&
 1444                             IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
 1445                                 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
 1446                                 log(LOG_ERR, "%s: possible hardware address "
 1447                                     "duplication detected, disable IPv6\n",
 1448                                     if_name(ifp));
 1449                         }
 1450                         break;
 1451                 }
 1452         }
 1453 
 1454         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1455         free(dp, M_IP6NDP);
 1456         dp = NULL;
 1457         ifa_free(ifa);
 1458 }
 1459 
 1460 static void
 1461 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
 1462 {
 1463         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1464         struct ifnet *ifp = ifa->ifa_ifp;
 1465 
 1466         dp->dad_ns_tcount++;
 1467         if ((ifp->if_flags & IFF_UP) == 0) {
 1468                 return;
 1469         }
 1470         if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
 1471                 return;
 1472         }
 1473 
 1474         dp->dad_ns_ocount++;
 1475         nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
 1476 }
 1477 
 1478 static void
 1479 nd6_dad_ns_input(struct ifaddr *ifa)
 1480 {
 1481         struct in6_ifaddr *ia;
 1482         struct ifnet *ifp;
 1483         const struct in6_addr *taddr6;
 1484         struct dadq *dp;
 1485         int duplicate;
 1486 
 1487         if (ifa == NULL)
 1488                 panic("ifa == NULL in nd6_dad_ns_input");
 1489 
 1490         ia = (struct in6_ifaddr *)ifa;
 1491         ifp = ifa->ifa_ifp;
 1492         taddr6 = &ia->ia_addr.sin6_addr;
 1493         duplicate = 0;
 1494         dp = nd6_dad_find(ifa);
 1495 
 1496         /* Quickhack - completely ignore DAD NS packets */
 1497         if (V_dad_ignore_ns) {
 1498                 char ip6buf[INET6_ADDRSTRLEN];
 1499                 nd6log((LOG_INFO,
 1500                     "nd6_dad_ns_input: ignoring DAD NS packet for "
 1501                     "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6),
 1502                     if_name(ifa->ifa_ifp)));
 1503                 return;
 1504         }
 1505 
 1506         /*
 1507          * if I'm yet to start DAD, someone else started using this address
 1508          * first.  I have a duplicate and you win.
 1509          */
 1510         if (dp == NULL || dp->dad_ns_ocount == 0)
 1511                 duplicate++;
 1512 
 1513         /* XXX more checks for loopback situation - see nd6_dad_timer too */
 1514 
 1515         if (duplicate) {
 1516                 dp = NULL;      /* will be freed in nd6_dad_duplicated() */
 1517                 nd6_dad_duplicated(ifa);
 1518         } else {
 1519                 /*
 1520                  * not sure if I got a duplicate.
 1521                  * increment ns count and see what happens.
 1522                  */
 1523                 if (dp)
 1524                         dp->dad_ns_icount++;
 1525         }
 1526 }
 1527 
 1528 static void
 1529 nd6_dad_na_input(struct ifaddr *ifa)
 1530 {
 1531         struct dadq *dp;
 1532 
 1533         if (ifa == NULL)
 1534                 panic("ifa == NULL in nd6_dad_na_input");
 1535 
 1536         dp = nd6_dad_find(ifa);
 1537         if (dp)
 1538                 dp->dad_na_icount++;
 1539 
 1540         /* remove the address. */
 1541         nd6_dad_duplicated(ifa);
 1542 }

Cache object: 630d1363c494f65be79cf044b7a4abe8


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