The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/nd6_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/8.3/sys/netinet6/nd6_nbr.c 220773 2011-04-18 12:18:27Z bz $");
   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 
   88 VNET_DEFINE(int, dad_ignore_ns) = 0;    /* ignore NS in DAD - specwise incorrect*/
   89 VNET_DEFINE(int, dad_maxtry) = 15;      /* max # of *tries* to transmit DAD packet */
   90 #define V_dad_ignore_ns                 VNET(dad_ignore_ns)
   91 #define V_dad_maxtry                    VNET(dad_maxtry)
   92 
   93 /*
   94  * Input a Neighbor Solicitation Message.
   95  *
   96  * Based on RFC 2461
   97  * Based on RFC 2462 (duplicate address detection)
   98  */
   99 void
  100 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
  101 {
  102         struct ifnet *ifp = m->m_pkthdr.rcvif;
  103         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  104         struct nd_neighbor_solicit *nd_ns;
  105         struct in6_addr saddr6 = ip6->ip6_src;
  106         struct in6_addr daddr6 = ip6->ip6_dst;
  107         struct in6_addr taddr6;
  108         struct in6_addr myaddr6;
  109         char *lladdr = NULL;
  110         struct ifaddr *ifa = NULL;
  111         int lladdrlen = 0;
  112         int anycast = 0, proxy = 0, tentative = 0;
  113         int tlladdr;
  114         union nd_opts ndopts;
  115         struct sockaddr_dl proxydl;
  116         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  117 
  118 #ifndef PULLDOWN_TEST
  119         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  120         nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
  121 #else
  122         IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
  123         if (nd_ns == NULL) {
  124                 ICMP6STAT_INC(icp6s_tooshort);
  125                 return;
  126         }
  127 #endif
  128         ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
  129         taddr6 = nd_ns->nd_ns_target;
  130         if (in6_setscope(&taddr6, ifp, NULL) != 0)
  131                 goto bad;
  132 
  133         if (ip6->ip6_hlim != 255) {
  134                 nd6log((LOG_ERR,
  135                     "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
  136                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  137                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  138                 goto bad;
  139         }
  140 
  141         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
  142                 /* dst has to be a solicited node multicast address. */
  143                 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
  144                     /* don't check ifindex portion */
  145                     daddr6.s6_addr32[1] == 0 &&
  146                     daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
  147                     daddr6.s6_addr8[12] == 0xff) {
  148                         ; /* good */
  149                 } else {
  150                         nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
  151                             "(wrong ip6 dst)\n"));
  152                         goto bad;
  153                 }
  154         } else if (!V_nd6_onlink_ns_rfc4861) {
  155                 struct sockaddr_in6 src_sa6;
  156 
  157                 /*
  158                  * According to recent IETF discussions, it is not a good idea
  159                  * to accept a NS from an address which would not be deemed
  160                  * to be a neighbor otherwise.  This point is expected to be
  161                  * clarified in future revisions of the specification.
  162                  */
  163                 bzero(&src_sa6, sizeof(src_sa6));
  164                 src_sa6.sin6_family = AF_INET6;
  165                 src_sa6.sin6_len = sizeof(src_sa6);
  166                 src_sa6.sin6_addr = saddr6;
  167                 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
  168                         nd6log((LOG_INFO, "nd6_ns_input: "
  169                                 "NS packet from non-neighbor\n"));
  170                         goto bad;
  171                 }
  172         }
  173 
  174         if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
  175                 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
  176                 goto bad;
  177         }
  178 
  179         icmp6len -= sizeof(*nd_ns);
  180         nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
  181         if (nd6_options(&ndopts) < 0) {
  182                 nd6log((LOG_INFO,
  183                     "nd6_ns_input: invalid ND option, ignored\n"));
  184                 /* nd6_options have incremented stats */
  185                 goto freeit;
  186         }
  187 
  188         if (ndopts.nd_opts_src_lladdr) {
  189                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  190                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  191         }
  192 
  193         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
  194                 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
  195                     "(link-layer address option)\n"));
  196                 goto bad;
  197         }
  198 
  199         /*
  200          * Attaching target link-layer address to the NA?
  201          * (RFC 2461 7.2.4)
  202          *
  203          * NS IP dst is unicast/anycast                 MUST NOT add
  204          * NS IP dst is solicited-node multicast        MUST add
  205          *
  206          * In implementation, we add target link-layer address by default.
  207          * We do not add one in MUST NOT cases.
  208          */
  209         if (!IN6_IS_ADDR_MULTICAST(&daddr6))
  210                 tlladdr = 0;
  211         else
  212                 tlladdr = 1;
  213 
  214         /*
  215          * Target address (taddr6) must be either:
  216          * (1) Valid unicast/anycast address for my receiving interface,
  217          * (2) Unicast address for which I'm offering proxy service, or
  218          * (3) "tentative" address on which DAD is being performed.
  219          */
  220         /* (1) and (3) check. */
  221         if (ifp->if_carp)
  222                 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
  223         if (ifa == NULL)
  224                 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
  225 
  226         /* (2) check. */
  227         if (ifa == NULL) {
  228                 struct rtentry *rt;
  229                 struct sockaddr_in6 tsin6;
  230                 int need_proxy;
  231 #ifdef RADIX_MPATH
  232                 struct route_in6 ro;
  233 #endif
  234 
  235                 bzero(&tsin6, sizeof tsin6);
  236                 tsin6.sin6_len = sizeof(struct sockaddr_in6);
  237                 tsin6.sin6_family = AF_INET6;
  238                 tsin6.sin6_addr = taddr6;
  239 
  240 #ifdef RADIX_MPATH
  241                 bzero(&ro, sizeof(ro));
  242                 ro.ro_dst = tsin6;
  243                 rtalloc_mpath((struct route *)&ro, RTF_ANNOUNCE);
  244                 rt = ro.ro_rt;
  245 #else
  246                 rt = rtalloc1((struct sockaddr *)&tsin6, 0, 0);
  247 #endif
  248                 need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
  249                     rt->rt_gateway->sa_family == AF_LINK);
  250                 if (rt != NULL) {
  251                         /*
  252                          * Make a copy while we can be sure that rt_gateway
  253                          * is still stable before unlocking to avoid lock
  254                          * order problems.  proxydl will only be used if
  255                          * proxy will be set in the next block.
  256                          */
  257                         if (need_proxy)
  258                                 proxydl = *SDL(rt->rt_gateway);
  259                         RTFREE_LOCKED(rt);
  260                 }
  261                 if (need_proxy) {
  262                         /*
  263                          * proxy NDP for single entry
  264                          */
  265                         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
  266                                 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
  267                         if (ifa)
  268                                 proxy = 1;
  269                 }
  270         }
  271         if (ifa == NULL) {
  272                 /*
  273                  * We've got an NS packet, and we don't have that adddress
  274                  * assigned for us.  We MUST silently ignore it.
  275                  * See RFC2461 7.2.3.
  276                  */
  277                 goto freeit;
  278         }
  279         myaddr6 = *IFA_IN6(ifa);
  280         anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
  281         tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
  282         if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
  283                 goto freeit;
  284 
  285         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  286                 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
  287                     "(if %d, NS packet %d)\n",
  288                     ip6_sprintf(ip6bufs, &taddr6),
  289                     ifp->if_addrlen, lladdrlen - 2));
  290                 goto bad;
  291         }
  292 
  293         if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
  294                 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
  295                     ip6_sprintf(ip6bufs, &saddr6)));
  296                 goto freeit;
  297         }
  298 
  299         /*
  300          * We have neighbor solicitation packet, with target address equals to
  301          * one of my tentative address.
  302          *
  303          * src addr     how to process?
  304          * ---          ---
  305          * multicast    of course, invalid (rejected in ip6_input)
  306          * unicast      somebody is doing address resolution -> ignore
  307          * unspec       dup address detection
  308          *
  309          * The processing is defined in RFC 2462.
  310          */
  311         if (tentative) {
  312                 /*
  313                  * If source address is unspecified address, it is for
  314                  * duplicate address detection.
  315                  *
  316                  * If not, the packet is for addess resolution;
  317                  * silently ignore it.
  318                  */
  319                 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
  320                         nd6_dad_ns_input(ifa);
  321 
  322                 goto freeit;
  323         }
  324 
  325         /*
  326          * If the source address is unspecified address, entries must not
  327          * be created or updated.
  328          * It looks that sender is performing DAD.  Output NA toward
  329          * all-node multicast address, to tell the sender that I'm using
  330          * the address.
  331          * S bit ("solicited") must be zero.
  332          */
  333         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
  334                 struct in6_addr in6_all;
  335 
  336                 in6_all = in6addr_linklocal_allnodes;
  337                 if (in6_setscope(&in6_all, ifp, NULL) != 0)
  338                         goto bad;
  339                 nd6_na_output(ifp, &in6_all, &taddr6,
  340                     ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  341                     (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0),
  342                     tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL);
  343                 goto freeit;
  344         }
  345 
  346         nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
  347             ND_NEIGHBOR_SOLICIT, 0);
  348 
  349         nd6_na_output(ifp, &saddr6, &taddr6,
  350             ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  351             (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
  352             tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL);
  353  freeit:
  354         if (ifa != NULL)
  355                 ifa_free(ifa);
  356         m_freem(m);
  357         return;
  358 
  359  bad:
  360         nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
  361                 ip6_sprintf(ip6bufs, &saddr6)));
  362         nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
  363                 ip6_sprintf(ip6bufs, &daddr6)));
  364         nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
  365                 ip6_sprintf(ip6bufs, &taddr6)));
  366         ICMP6STAT_INC(icp6s_badns);
  367         if (ifa != NULL)
  368                 ifa_free(ifa);
  369         m_freem(m);
  370 }
  371 
  372 /*
  373  * Output a Neighbor Solicitation Message. Caller specifies:
  374  *      - ICMP6 header source IP6 address
  375  *      - ND6 header target IP6 address
  376  *      - ND6 header source datalink address
  377  *
  378  * Based on RFC 2461
  379  * Based on RFC 2462 (duplicate address detection)
  380  *
  381  *   ln - for source address determination
  382  *  dad - duplicate address detection
  383  */
  384 void
  385 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 
  386     const struct in6_addr *taddr6, struct llentry *ln, int dad)
  387 {
  388         struct mbuf *m;
  389         struct ip6_hdr *ip6;
  390         struct nd_neighbor_solicit *nd_ns;
  391         struct ip6_moptions im6o;
  392         int icmp6len;
  393         int maxlen;
  394         caddr_t mac;
  395         struct route_in6 ro;
  396 
  397         if (IN6_IS_ADDR_MULTICAST(taddr6))
  398                 return;
  399 
  400         /* estimate the size of message */
  401         maxlen = sizeof(*ip6) + sizeof(*nd_ns);
  402         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  403         if (max_linkhdr + maxlen >= MCLBYTES) {
  404 #ifdef DIAGNOSTIC
  405                 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
  406                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  407 #endif
  408                 return;
  409         }
  410 
  411         MGETHDR(m, M_DONTWAIT, MT_DATA);
  412         if (m && max_linkhdr + maxlen >= MHLEN) {
  413                 MCLGET(m, M_DONTWAIT);
  414                 if ((m->m_flags & M_EXT) == 0) {
  415                         m_free(m);
  416                         m = NULL;
  417                 }
  418         }
  419         if (m == NULL)
  420                 return;
  421         m->m_pkthdr.rcvif = NULL;
  422 
  423         bzero(&ro, sizeof(ro));
  424 
  425         if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
  426                 m->m_flags |= M_MCAST;
  427                 im6o.im6o_multicast_ifp = ifp;
  428                 im6o.im6o_multicast_hlim = 255;
  429                 im6o.im6o_multicast_loop = 0;
  430         }
  431 
  432         icmp6len = sizeof(*nd_ns);
  433         m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
  434         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  435 
  436         /* fill neighbor solicitation packet */
  437         ip6 = mtod(m, struct ip6_hdr *);
  438         ip6->ip6_flow = 0;
  439         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  440         ip6->ip6_vfc |= IPV6_VERSION;
  441         /* ip6->ip6_plen will be set later */
  442         ip6->ip6_nxt = IPPROTO_ICMPV6;
  443         ip6->ip6_hlim = 255;
  444         if (daddr6)
  445                 ip6->ip6_dst = *daddr6;
  446         else {
  447                 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  448                 ip6->ip6_dst.s6_addr16[1] = 0;
  449                 ip6->ip6_dst.s6_addr32[1] = 0;
  450                 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
  451                 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
  452                 ip6->ip6_dst.s6_addr8[12] = 0xff;
  453                 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
  454                         goto bad;
  455         }
  456         if (!dad) {
  457                 struct ifaddr *ifa;
  458 
  459                 /*
  460                  * RFC2461 7.2.2:
  461                  * "If the source address of the packet prompting the
  462                  * solicitation is the same as one of the addresses assigned
  463                  * to the outgoing interface, that address SHOULD be placed
  464                  * in the IP Source Address of the outgoing solicitation.
  465                  * Otherwise, any one of the addresses assigned to the
  466                  * interface should be used."
  467                  *
  468                  * We use the source address for the prompting packet
  469                  * (saddr6), if:
  470                  * - saddr6 is given from the caller (by giving "ln"), and
  471                  * - saddr6 belongs to the outgoing interface.
  472                  * Otherwise, we perform the source address selection as usual.
  473                  */
  474                 struct in6_addr *hsrc;
  475 
  476                 hsrc = NULL;
  477                 if (ln != NULL) {
  478                         LLE_RLOCK(ln);
  479                         if (ln->la_hold != NULL) {
  480                                 struct ip6_hdr *hip6;           /* hold ip6 */
  481 
  482                                 /*
  483                                  * assuming every packet in la_hold has the same IP
  484                                  * header
  485                                  */
  486                                 hip6 = mtod(ln->la_hold, struct ip6_hdr *);
  487                                 /* XXX pullup? */
  488                                 if (sizeof(*hip6) < ln->la_hold->m_len) {
  489                                         ip6->ip6_src = hip6->ip6_src;
  490                                         hsrc = &hip6->ip6_src;
  491                                 }
  492                         }
  493                         LLE_RUNLOCK(ln);
  494                 }
  495                 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
  496                     hsrc)) != NULL) {
  497                         /* ip6_src set already. */
  498                         ifa_free(ifa);
  499                 } else {
  500                         int error;
  501                         struct sockaddr_in6 dst_sa;
  502                         struct in6_addr src_in;
  503 
  504                         bzero(&dst_sa, sizeof(dst_sa));
  505                         dst_sa.sin6_family = AF_INET6;
  506                         dst_sa.sin6_len = sizeof(dst_sa);
  507                         dst_sa.sin6_addr = ip6->ip6_dst;
  508 
  509                         error = in6_selectsrc(&dst_sa, NULL,
  510                             NULL, &ro, NULL, NULL, &src_in);
  511                         if (error) {
  512                                 char ip6buf[INET6_ADDRSTRLEN];
  513                                 nd6log((LOG_DEBUG,
  514                                     "nd6_ns_output: source can't be "
  515                                     "determined: dst=%s, error=%d\n",
  516                                     ip6_sprintf(ip6buf, &dst_sa.sin6_addr),
  517                                     error));
  518                                 goto bad;
  519                         }
  520                         ip6->ip6_src = src_in;
  521                 }
  522         } else {
  523                 /*
  524                  * Source address for DAD packet must always be IPv6
  525                  * unspecified address. (0::0)
  526                  * We actually don't have to 0-clear the address (we did it
  527                  * above), but we do so here explicitly to make the intention
  528                  * clearer.
  529                  */
  530                 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
  531         }
  532         nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
  533         nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
  534         nd_ns->nd_ns_code = 0;
  535         nd_ns->nd_ns_reserved = 0;
  536         nd_ns->nd_ns_target = *taddr6;
  537         in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
  538 
  539         /*
  540          * Add source link-layer address option.
  541          *
  542          *                              spec            implementation
  543          *                              ---             ---
  544          * DAD packet                   MUST NOT        do not add the option
  545          * there's no link layer address:
  546          *                              impossible      do not add the option
  547          * there's link layer address:
  548          *      Multicast NS            MUST add one    add the option
  549          *      Unicast NS              SHOULD add one  add the option
  550          */
  551         if (!dad && (mac = nd6_ifptomac(ifp))) {
  552                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
  553                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
  554                 /* 8 byte alignments... */
  555                 optlen = (optlen + 7) & ~7;
  556 
  557                 m->m_pkthdr.len += optlen;
  558                 m->m_len += optlen;
  559                 icmp6len += optlen;
  560                 bzero((caddr_t)nd_opt, optlen);
  561                 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
  562                 nd_opt->nd_opt_len = optlen >> 3;
  563                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
  564         }
  565 
  566         ip6->ip6_plen = htons((u_short)icmp6len);
  567         nd_ns->nd_ns_cksum = 0;
  568         nd_ns->nd_ns_cksum =
  569             in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
  570 
  571         ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
  572         icmp6_ifstat_inc(ifp, ifs6_out_msg);
  573         icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
  574         ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
  575 
  576         if (ro.ro_rt) {         /* we don't cache this route. */
  577                 RTFREE(ro.ro_rt);
  578         }
  579         return;
  580 
  581   bad:
  582         if (ro.ro_rt) {
  583                 RTFREE(ro.ro_rt);
  584         }
  585         m_freem(m);
  586         return;
  587 }
  588 
  589 /*
  590  * Neighbor advertisement input handling.
  591  *
  592  * Based on RFC 2461
  593  * Based on RFC 2462 (duplicate address detection)
  594  *
  595  * the following items are not implemented yet:
  596  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  597  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  598  */
  599 void
  600 nd6_na_input(struct mbuf *m, int off, int icmp6len)
  601 {
  602         struct ifnet *ifp = m->m_pkthdr.rcvif;
  603         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  604         struct nd_neighbor_advert *nd_na;
  605         struct in6_addr daddr6 = ip6->ip6_dst;
  606         struct in6_addr taddr6;
  607         int flags;
  608         int is_router;
  609         int is_solicited;
  610         int is_override;
  611         char *lladdr = NULL;
  612         int lladdrlen = 0;
  613         int checklink = 0;
  614         struct ifaddr *ifa;
  615         struct llentry *ln = NULL;
  616         union nd_opts ndopts;
  617         struct mbuf *chain = NULL;
  618         struct sockaddr_in6 sin6;
  619         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  620 
  621         if (ip6->ip6_hlim != 255) {
  622                 nd6log((LOG_ERR,
  623                     "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
  624                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  625                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  626                 goto bad;
  627         }
  628 
  629 #ifndef PULLDOWN_TEST
  630         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  631         nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
  632 #else
  633         IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
  634         if (nd_na == NULL) {
  635                 ICMP6STAT_INC(icp6s_tooshort);
  636                 return;
  637         }
  638 #endif
  639 
  640         flags = nd_na->nd_na_flags_reserved;
  641         is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
  642         is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
  643         is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
  644 
  645         taddr6 = nd_na->nd_na_target;
  646         if (in6_setscope(&taddr6, ifp, NULL))
  647                 goto bad;       /* XXX: impossible */
  648 
  649         if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
  650                 nd6log((LOG_ERR,
  651                     "nd6_na_input: invalid target address %s\n",
  652                     ip6_sprintf(ip6bufs, &taddr6)));
  653                 goto bad;
  654         }
  655         if (IN6_IS_ADDR_MULTICAST(&daddr6))
  656                 if (is_solicited) {
  657                         nd6log((LOG_ERR,
  658                             "nd6_na_input: a solicited adv is multicasted\n"));
  659                         goto bad;
  660                 }
  661 
  662         icmp6len -= sizeof(*nd_na);
  663         nd6_option_init(nd_na + 1, icmp6len, &ndopts);
  664         if (nd6_options(&ndopts) < 0) {
  665                 nd6log((LOG_INFO,
  666                     "nd6_na_input: invalid ND option, ignored\n"));
  667                 /* nd6_options have incremented stats */
  668                 goto freeit;
  669         }
  670 
  671         if (ndopts.nd_opts_tgt_lladdr) {
  672                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
  673                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
  674         }
  675 
  676         ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
  677 
  678         /*
  679          * Target address matches one of my interface address.
  680          *
  681          * If my address is tentative, this means that there's somebody
  682          * already using the same address as mine.  This indicates DAD failure.
  683          * This is defined in RFC 2462.
  684          *
  685          * Otherwise, process as defined in RFC 2461.
  686          */
  687         if (ifa
  688          && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
  689                 ifa_free(ifa);
  690                 nd6_dad_na_input(ifa);
  691                 goto freeit;
  692         }
  693 
  694         /* Just for safety, maybe unnecessary. */
  695         if (ifa) {
  696                 ifa_free(ifa);
  697                 log(LOG_ERR,
  698                     "nd6_na_input: duplicate IP6 address %s\n",
  699                     ip6_sprintf(ip6bufs, &taddr6));
  700                 goto freeit;
  701         }
  702 
  703         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  704                 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
  705                     "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
  706                     ifp->if_addrlen, lladdrlen - 2));
  707                 goto bad;
  708         }
  709 
  710         /*
  711          * If no neighbor cache entry is found, NA SHOULD silently be
  712          * discarded.
  713          */
  714         IF_AFDATA_LOCK(ifp);
  715         ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
  716         IF_AFDATA_UNLOCK(ifp);
  717         if (ln == NULL) {
  718                 goto freeit;
  719         }
  720 
  721         if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
  722                 /*
  723                  * If the link-layer has address, and no lladdr option came,
  724                  * discard the packet.
  725                  */
  726                 if (ifp->if_addrlen && lladdr == NULL) {
  727                         goto freeit;
  728                 }
  729 
  730                 /*
  731                  * Record link-layer address, and update the state.
  732                  */
  733                 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
  734                 ln->la_flags |= LLE_VALID;
  735                 if (is_solicited) {
  736                         ln->ln_state = ND6_LLINFO_REACHABLE;
  737                         ln->ln_byhint = 0;
  738                         if (!ND6_LLINFO_PERMANENT(ln)) {
  739                                 nd6_llinfo_settimer_locked(ln,
  740                                     (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz);
  741                         }
  742                 } else {
  743                         ln->ln_state = ND6_LLINFO_STALE;
  744                         nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
  745                 }
  746                 if ((ln->ln_router = is_router) != 0) {
  747                         /*
  748                          * This means a router's state has changed from
  749                          * non-reachable to probably reachable, and might
  750                          * affect the status of associated prefixes..
  751                          */
  752                         checklink = 1;
  753                 }
  754         } else {
  755                 int llchange;
  756 
  757                 /*
  758                  * Check if the link-layer address has changed or not.
  759                  */
  760                 if (lladdr == NULL)
  761                         llchange = 0;
  762                 else {
  763                         if (ln->la_flags & LLE_VALID) {
  764                                 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen))
  765                                         llchange = 1;
  766                                 else
  767                                         llchange = 0;
  768                         } else
  769                                 llchange = 1;
  770                 }
  771 
  772                 /*
  773                  * This is VERY complex.  Look at it with care.
  774                  *
  775                  * override solicit lladdr llchange     action
  776                  *                                      (L: record lladdr)
  777                  *
  778                  *      0       0       n       --      (2c)
  779                  *      0       0       y       n       (2b) L
  780                  *      0       0       y       y       (1)    REACHABLE->STALE
  781                  *      0       1       n       --      (2c)   *->REACHABLE
  782                  *      0       1       y       n       (2b) L *->REACHABLE
  783                  *      0       1       y       y       (1)    REACHABLE->STALE
  784                  *      1       0       n       --      (2a)
  785                  *      1       0       y       n       (2a) L
  786                  *      1       0       y       y       (2a) L *->STALE
  787                  *      1       1       n       --      (2a)   *->REACHABLE
  788                  *      1       1       y       n       (2a) L *->REACHABLE
  789                  *      1       1       y       y       (2a) L *->REACHABLE
  790                  */
  791                 if (!is_override && (lladdr != NULL && llchange)) {  /* (1) */
  792                         /*
  793                          * If state is REACHABLE, make it STALE.
  794                          * no other updates should be done.
  795                          */
  796                         if (ln->ln_state == ND6_LLINFO_REACHABLE) {
  797                                 ln->ln_state = ND6_LLINFO_STALE;
  798                                 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
  799                         }
  800                         goto freeit;
  801                 } else if (is_override                             /* (2a) */
  802                         || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
  803                         || lladdr == NULL) {                       /* (2c) */
  804                         /*
  805                          * Update link-local address, if any.
  806                          */
  807                         if (lladdr != NULL) {
  808                                 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
  809                                 ln->la_flags |= LLE_VALID;
  810                         }
  811 
  812                         /*
  813                          * If solicited, make the state REACHABLE.
  814                          * If not solicited and the link-layer address was
  815                          * changed, make it STALE.
  816                          */
  817                         if (is_solicited) {
  818                                 ln->ln_state = ND6_LLINFO_REACHABLE;
  819                                 ln->ln_byhint = 0;
  820                                 if (!ND6_LLINFO_PERMANENT(ln)) {
  821                                         nd6_llinfo_settimer_locked(ln,
  822                                             (long)ND_IFINFO(ifp)->reachable * hz);
  823                                 }
  824                         } else {
  825                                 if (lladdr != NULL && llchange) {
  826                                         ln->ln_state = ND6_LLINFO_STALE;
  827                                         nd6_llinfo_settimer_locked(ln,
  828                                             (long)V_nd6_gctimer * hz);
  829                                 }
  830                         }
  831                 }
  832 
  833                 if (ln->ln_router && !is_router) {
  834                         /*
  835                          * The peer dropped the router flag.
  836                          * Remove the sender from the Default Router List and
  837                          * update the Destination Cache entries.
  838                          */
  839                         struct nd_defrouter *dr;
  840                         struct in6_addr *in6;
  841 
  842                         in6 = &L3_ADDR_SIN6(ln)->sin6_addr;
  843 
  844                         /*
  845                          * Lock to protect the default router list.
  846                          * XXX: this might be unnecessary, since this function
  847                          * is only called under the network software interrupt
  848                          * context.  However, we keep it just for safety.
  849                          */
  850                         dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp);
  851                         if (dr)
  852                                 defrtrlist_del(dr);
  853                         else if (!V_ip6_forwarding) {
  854                                 /*
  855                                  * Even if the neighbor is not in the default
  856                                  * router list, the neighbor may be used
  857                                  * as a next hop for some destinations
  858                                  * (e.g. redirect case). So we must
  859                                  * call rt6_flush explicitly.
  860                                  */
  861                                 rt6_flush(&ip6->ip6_src, ifp);
  862                         }
  863                 }
  864                 ln->ln_router = is_router;
  865         }
  866         /* XXX - QL
  867          *  Does this matter?
  868          *  rt->rt_flags &= ~RTF_REJECT;
  869          */
  870         ln->la_asked = 0;
  871         if (ln->la_hold) {
  872                 struct mbuf *m_hold, *m_hold_next;
  873 
  874                 /*
  875                  * reset the la_hold in advance, to explicitly
  876                  * prevent a la_hold lookup in nd6_output()
  877                  * (wouldn't happen, though...)
  878                  */
  879                 for (m_hold = ln->la_hold, ln->la_hold = NULL;
  880                     m_hold; m_hold = m_hold_next) {
  881                         m_hold_next = m_hold->m_nextpkt;
  882                         m_hold->m_nextpkt = NULL;
  883                         /*
  884                          * we assume ifp is not a loopback here, so just set
  885                          * the 2nd argument as the 1st one.
  886                          */
  887                         nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
  888                 }
  889         }
  890  freeit:
  891         if (ln != NULL) {
  892                 if (chain)
  893                         memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
  894                 LLE_WUNLOCK(ln);
  895 
  896                 if (chain)
  897                         nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
  898         }
  899         if (checklink)
  900                 pfxlist_onlink_check();
  901 
  902         m_freem(m);
  903         return;
  904 
  905  bad:
  906         if (ln != NULL)
  907                 LLE_WUNLOCK(ln);
  908 
  909         ICMP6STAT_INC(icp6s_badna);
  910         m_freem(m);
  911 }
  912 
  913 /*
  914  * Neighbor advertisement output handling.
  915  *
  916  * Based on RFC 2461
  917  *
  918  * the following items are not implemented yet:
  919  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  920  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  921  *
  922  * tlladdr - 1 if include target link-layer address
  923  * sdl0 - sockaddr_dl (= proxy NA) or NULL
  924  */
  925 void
  926 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
  927     const struct in6_addr *taddr6, u_long flags, int tlladdr,
  928     struct sockaddr *sdl0)
  929 {
  930         struct mbuf *m;
  931         struct ip6_hdr *ip6;
  932         struct nd_neighbor_advert *nd_na;
  933         struct ip6_moptions im6o;
  934         struct in6_addr src, daddr6;
  935         struct sockaddr_in6 dst_sa;
  936         int icmp6len, maxlen, error;
  937         caddr_t mac = NULL;
  938         struct route_in6 ro;
  939 
  940         bzero(&ro, sizeof(ro));
  941 
  942         daddr6 = *daddr6_0;     /* make a local copy for modification */
  943 
  944         /* estimate the size of message */
  945         maxlen = sizeof(*ip6) + sizeof(*nd_na);
  946         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  947         if (max_linkhdr + maxlen >= MCLBYTES) {
  948 #ifdef DIAGNOSTIC
  949                 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
  950                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  951 #endif
  952                 return;
  953         }
  954 
  955         MGETHDR(m, M_DONTWAIT, MT_DATA);
  956         if (m && max_linkhdr + maxlen >= MHLEN) {
  957                 MCLGET(m, M_DONTWAIT);
  958                 if ((m->m_flags & M_EXT) == 0) {
  959                         m_free(m);
  960                         m = NULL;
  961                 }
  962         }
  963         if (m == NULL)
  964                 return;
  965         m->m_pkthdr.rcvif = NULL;
  966 
  967         if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
  968                 m->m_flags |= M_MCAST;
  969                 im6o.im6o_multicast_ifp = ifp;
  970                 im6o.im6o_multicast_hlim = 255;
  971                 im6o.im6o_multicast_loop = 0;
  972         }
  973 
  974         icmp6len = sizeof(*nd_na);
  975         m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
  976         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  977 
  978         /* fill neighbor advertisement packet */
  979         ip6 = mtod(m, struct ip6_hdr *);
  980         ip6->ip6_flow = 0;
  981         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  982         ip6->ip6_vfc |= IPV6_VERSION;
  983         ip6->ip6_nxt = IPPROTO_ICMPV6;
  984         ip6->ip6_hlim = 255;
  985         if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
  986                 /* reply to DAD */
  987                 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  988                 daddr6.s6_addr16[1] = 0;
  989                 daddr6.s6_addr32[1] = 0;
  990                 daddr6.s6_addr32[2] = 0;
  991                 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
  992                 if (in6_setscope(&daddr6, ifp, NULL))
  993                         goto bad;
  994 
  995                 flags &= ~ND_NA_FLAG_SOLICITED;
  996         }
  997         ip6->ip6_dst = daddr6;
  998         bzero(&dst_sa, sizeof(struct sockaddr_in6));
  999         dst_sa.sin6_family = AF_INET6;
 1000         dst_sa.sin6_len = sizeof(struct sockaddr_in6);
 1001         dst_sa.sin6_addr = daddr6;
 1002 
 1003         /*
 1004          * Select a source whose scope is the same as that of the dest.
 1005          */
 1006         bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
 1007         error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, NULL, &src);
 1008         if (error) {
 1009                 char ip6buf[INET6_ADDRSTRLEN];
 1010                 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
 1011                     "determined: dst=%s, error=%d\n",
 1012                     ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error));
 1013                 goto bad;
 1014         }
 1015         ip6->ip6_src = src;
 1016         nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
 1017         nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
 1018         nd_na->nd_na_code = 0;
 1019         nd_na->nd_na_target = *taddr6;
 1020         in6_clearscope(&nd_na->nd_na_target); /* XXX */
 1021 
 1022         /*
 1023          * "tlladdr" indicates NS's condition for adding tlladdr or not.
 1024          * see nd6_ns_input() for details.
 1025          * Basically, if NS packet is sent to unicast/anycast addr,
 1026          * target lladdr option SHOULD NOT be included.
 1027          */
 1028         if (tlladdr) {
 1029                 /*
 1030                  * sdl0 != NULL indicates proxy NA.  If we do proxy, use
 1031                  * lladdr in sdl0.  If we are not proxying (sending NA for
 1032                  * my address) use lladdr configured for the interface.
 1033                  */
 1034                 if (sdl0 == NULL) {
 1035                         if (ifp->if_carp)
 1036                                 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
 1037                         if (mac == NULL)
 1038                                 mac = nd6_ifptomac(ifp);
 1039                 } else if (sdl0->sa_family == AF_LINK) {
 1040                         struct sockaddr_dl *sdl;
 1041                         sdl = (struct sockaddr_dl *)sdl0;
 1042                         if (sdl->sdl_alen == ifp->if_addrlen)
 1043                                 mac = LLADDR(sdl);
 1044                 }
 1045         }
 1046         if (tlladdr && mac) {
 1047                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
 1048                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
 1049 
 1050                 /* roundup to 8 bytes alignment! */
 1051                 optlen = (optlen + 7) & ~7;
 1052 
 1053                 m->m_pkthdr.len += optlen;
 1054                 m->m_len += optlen;
 1055                 icmp6len += optlen;
 1056                 bzero((caddr_t)nd_opt, optlen);
 1057                 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
 1058                 nd_opt->nd_opt_len = optlen >> 3;
 1059                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
 1060         } else
 1061                 flags &= ~ND_NA_FLAG_OVERRIDE;
 1062 
 1063         ip6->ip6_plen = htons((u_short)icmp6len);
 1064         nd_na->nd_na_flags_reserved = flags;
 1065         nd_na->nd_na_cksum = 0;
 1066         nd_na->nd_na_cksum =
 1067             in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
 1068 
 1069         ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL);
 1070         icmp6_ifstat_inc(ifp, ifs6_out_msg);
 1071         icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
 1072         ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
 1073 
 1074         if (ro.ro_rt) {         /* we don't cache this route. */
 1075                 RTFREE(ro.ro_rt);
 1076         }
 1077         return;
 1078 
 1079   bad:
 1080         if (ro.ro_rt) {
 1081                 RTFREE(ro.ro_rt);
 1082         }
 1083         m_freem(m);
 1084         return;
 1085 }
 1086 
 1087 caddr_t
 1088 nd6_ifptomac(struct ifnet *ifp)
 1089 {
 1090         switch (ifp->if_type) {
 1091         case IFT_ARCNET:
 1092         case IFT_ETHER:
 1093         case IFT_FDDI:
 1094         case IFT_IEEE1394:
 1095 #ifdef IFT_L2VLAN
 1096         case IFT_L2VLAN:
 1097 #endif
 1098 #ifdef IFT_IEEE80211
 1099         case IFT_IEEE80211:
 1100 #endif
 1101 #ifdef IFT_CARP
 1102         case IFT_CARP:
 1103 #endif
 1104         case IFT_BRIDGE:
 1105         case IFT_ISO88025:
 1106                 return IF_LLADDR(ifp);
 1107         default:
 1108                 return NULL;
 1109         }
 1110 }
 1111 
 1112 struct dadq {
 1113         TAILQ_ENTRY(dadq) dad_list;
 1114         struct ifaddr *dad_ifa;
 1115         int dad_count;          /* max NS to send */
 1116         int dad_ns_tcount;      /* # of trials to send NS */
 1117         int dad_ns_ocount;      /* NS sent so far */
 1118         int dad_ns_icount;
 1119         int dad_na_icount;
 1120         struct callout dad_timer_ch;
 1121         struct vnet *dad_vnet;
 1122 };
 1123 
 1124 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
 1125 VNET_DEFINE(int, dad_init) = 0;
 1126 #define V_dadq                          VNET(dadq)
 1127 #define V_dad_init                      VNET(dad_init)
 1128 
 1129 static struct dadq *
 1130 nd6_dad_find(struct ifaddr *ifa)
 1131 {
 1132         struct dadq *dp;
 1133 
 1134         for (dp = V_dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
 1135                 if (dp->dad_ifa == ifa)
 1136                         return dp;
 1137         }
 1138         return NULL;
 1139 }
 1140 
 1141 static void
 1142 nd6_dad_starttimer(struct dadq *dp, int ticks)
 1143 {
 1144 
 1145         callout_reset(&dp->dad_timer_ch, ticks,
 1146             (void (*)(void *))nd6_dad_timer, (void *)dp);
 1147 }
 1148 
 1149 static void
 1150 nd6_dad_stoptimer(struct dadq *dp)
 1151 {
 1152 
 1153         callout_stop(&dp->dad_timer_ch);
 1154 }
 1155 
 1156 /*
 1157  * Start Duplicate Address Detection (DAD) for specified interface address.
 1158  */
 1159 void
 1160 nd6_dad_start(struct ifaddr *ifa, int delay)
 1161 {
 1162         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1163         struct dadq *dp;
 1164         char ip6buf[INET6_ADDRSTRLEN];
 1165 
 1166         if (!V_dad_init) {
 1167                 TAILQ_INIT(&V_dadq);
 1168                 V_dad_init++;
 1169         }
 1170 
 1171         /*
 1172          * If we don't need DAD, don't do it.
 1173          * There are several cases:
 1174          * - DAD is disabled (ip6_dad_count == 0)
 1175          * - the interface address is anycast
 1176          */
 1177         if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
 1178                 log(LOG_DEBUG,
 1179                         "nd6_dad_start: called with non-tentative address "
 1180                         "%s(%s)\n",
 1181                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1182                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1183                 return;
 1184         }
 1185         if (ia->ia6_flags & IN6_IFF_ANYCAST) {
 1186                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1187                 return;
 1188         }
 1189         if (!V_ip6_dad_count) {
 1190                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1191                 return;
 1192         }
 1193         if (ifa->ifa_ifp == NULL)
 1194                 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
 1195         if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
 1196                 return;
 1197         }
 1198         if (nd6_dad_find(ifa) != NULL) {
 1199                 /* DAD already in progress */
 1200                 return;
 1201         }
 1202 
 1203         dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
 1204         if (dp == NULL) {
 1205                 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
 1206                         "%s(%s)\n",
 1207                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1208                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1209                 return;
 1210         }
 1211         bzero(dp, sizeof(*dp));
 1212         callout_init(&dp->dad_timer_ch, 0);
 1213 #ifdef VIMAGE
 1214         dp->dad_vnet = curvnet;
 1215 #endif
 1216         TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list);
 1217 
 1218         nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
 1219             ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
 1220 
 1221         /*
 1222          * Send NS packet for DAD, ip6_dad_count times.
 1223          * Note that we must delay the first transmission, if this is the
 1224          * first packet to be sent from the interface after interface
 1225          * (re)initialization.
 1226          */
 1227         dp->dad_ifa = ifa;
 1228         ifa_ref(ifa);   /* just for safety */
 1229         dp->dad_count = V_ip6_dad_count;
 1230         dp->dad_ns_icount = dp->dad_na_icount = 0;
 1231         dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
 1232         if (delay == 0) {
 1233                 nd6_dad_ns_output(dp, ifa);
 1234                 nd6_dad_starttimer(dp,
 1235                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1236         } else {
 1237                 nd6_dad_starttimer(dp, delay);
 1238         }
 1239 }
 1240 
 1241 /*
 1242  * terminate DAD unconditionally.  used for address removals.
 1243  */
 1244 void
 1245 nd6_dad_stop(struct ifaddr *ifa)
 1246 {
 1247         struct dadq *dp;
 1248 
 1249         if (!V_dad_init)
 1250                 return;
 1251         dp = nd6_dad_find(ifa);
 1252         if (!dp) {
 1253                 /* DAD wasn't started yet */
 1254                 return;
 1255         }
 1256 
 1257         nd6_dad_stoptimer(dp);
 1258 
 1259         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1260         free(dp, M_IP6NDP);
 1261         dp = NULL;
 1262         ifa_free(ifa);
 1263 }
 1264 
 1265 static void
 1266 nd6_dad_timer(struct dadq *dp)
 1267 {
 1268         CURVNET_SET(dp->dad_vnet);
 1269         int s;
 1270         struct ifaddr *ifa = dp->dad_ifa;
 1271         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1272         char ip6buf[INET6_ADDRSTRLEN];
 1273 
 1274         s = splnet();           /* XXX */
 1275 
 1276         /* Sanity check */
 1277         if (ia == NULL) {
 1278                 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
 1279                 goto done;
 1280         }
 1281         if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
 1282                 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
 1283                         "%s(%s)\n",
 1284                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1285                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1286                 goto done;
 1287         }
 1288         if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
 1289                 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
 1290                         "%s(%s)\n",
 1291                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1292                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1293                 goto done;
 1294         }
 1295 
 1296         /* timeouted with IFF_{RUNNING,UP} check */
 1297         if (dp->dad_ns_tcount > V_dad_maxtry) {
 1298                 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
 1299                     if_name(ifa->ifa_ifp)));
 1300 
 1301                 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1302                 free(dp, M_IP6NDP);
 1303                 dp = NULL;
 1304                 ifa_free(ifa);
 1305                 goto done;
 1306         }
 1307 
 1308         /* Need more checks? */
 1309         if (dp->dad_ns_ocount < dp->dad_count) {
 1310                 /*
 1311                  * We have more NS to go.  Send NS packet for DAD.
 1312                  */
 1313                 nd6_dad_ns_output(dp, ifa);
 1314                 nd6_dad_starttimer(dp,
 1315                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1316         } else {
 1317                 /*
 1318                  * We have transmitted sufficient number of DAD packets.
 1319                  * See what we've got.
 1320                  */
 1321                 int duplicate;
 1322 
 1323                 duplicate = 0;
 1324 
 1325                 if (dp->dad_na_icount) {
 1326                         /*
 1327                          * the check is in nd6_dad_na_input(),
 1328                          * but just in case
 1329                          */
 1330                         duplicate++;
 1331                 }
 1332 
 1333                 if (dp->dad_ns_icount) {
 1334                         /* We've seen NS, means DAD has failed. */
 1335                         duplicate++;
 1336                 }
 1337 
 1338                 if (duplicate) {
 1339                         /* (*dp) will be freed in nd6_dad_duplicated() */
 1340                         dp = NULL;
 1341                         nd6_dad_duplicated(ifa);
 1342                 } else {
 1343                         /*
 1344                          * We are done with DAD.  No NA came, no NS came.
 1345                          * No duplicate address found.
 1346                          */
 1347                         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1348 
 1349                         nd6log((LOG_DEBUG,
 1350                             "%s: DAD complete for %s - no duplicates found\n",
 1351                             if_name(ifa->ifa_ifp),
 1352                             ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
 1353 
 1354                         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1355                         free(dp, M_IP6NDP);
 1356                         dp = NULL;
 1357                         ifa_free(ifa);
 1358                 }
 1359         }
 1360 
 1361 done:
 1362         splx(s);
 1363         CURVNET_RESTORE();
 1364 }
 1365 
 1366 void
 1367 nd6_dad_duplicated(struct ifaddr *ifa)
 1368 {
 1369         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1370         struct ifnet *ifp;
 1371         struct dadq *dp;
 1372         char ip6buf[INET6_ADDRSTRLEN];
 1373 
 1374         dp = nd6_dad_find(ifa);
 1375         if (dp == NULL) {
 1376                 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
 1377                 return;
 1378         }
 1379 
 1380         log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
 1381             "NS in/out=%d/%d, NA in=%d\n",
 1382             if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1383             dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
 1384 
 1385         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1386         ia->ia6_flags |= IN6_IFF_DUPLICATED;
 1387 
 1388         /* We are done with DAD, with duplicate address found. (failure) */
 1389         nd6_dad_stoptimer(dp);
 1390 
 1391         ifp = ifa->ifa_ifp;
 1392         log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
 1393             if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
 1394         log(LOG_ERR, "%s: manual intervention required\n",
 1395             if_name(ifp));
 1396 
 1397         /*
 1398          * If the address is a link-local address formed from an interface
 1399          * identifier based on the hardware address which is supposed to be
 1400          * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
 1401          * operation on the interface SHOULD be disabled.
 1402          * [rfc2462bis-03 Section 5.4.5]
 1403          */
 1404         if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
 1405                 struct in6_addr in6;
 1406 
 1407                 /*
 1408                  * To avoid over-reaction, we only apply this logic when we are
 1409                  * very sure that hardware addresses are supposed to be unique.
 1410                  */
 1411                 switch (ifp->if_type) {
 1412                 case IFT_ETHER:
 1413                 case IFT_FDDI:
 1414                 case IFT_ATM:
 1415                 case IFT_IEEE1394:
 1416 #ifdef IFT_IEEE80211
 1417                 case IFT_IEEE80211:
 1418 #endif
 1419                         in6 = ia->ia_addr.sin6_addr;
 1420                         if (in6_get_hw_ifid(ifp, &in6) == 0 &&
 1421                             IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
 1422                                 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
 1423                                 log(LOG_ERR, "%s: possible hardware address "
 1424                                     "duplication detected, disable IPv6\n",
 1425                                     if_name(ifp));
 1426                         }
 1427                         break;
 1428                 }
 1429         }
 1430 
 1431         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1432         free(dp, M_IP6NDP);
 1433         dp = NULL;
 1434         ifa_free(ifa);
 1435 }
 1436 
 1437 static void
 1438 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
 1439 {
 1440         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1441         struct ifnet *ifp = ifa->ifa_ifp;
 1442 
 1443         dp->dad_ns_tcount++;
 1444         if ((ifp->if_flags & IFF_UP) == 0) {
 1445                 return;
 1446         }
 1447         if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
 1448                 return;
 1449         }
 1450 
 1451         dp->dad_ns_ocount++;
 1452         nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
 1453 }
 1454 
 1455 static void
 1456 nd6_dad_ns_input(struct ifaddr *ifa)
 1457 {
 1458         struct in6_ifaddr *ia;
 1459         struct ifnet *ifp;
 1460         const struct in6_addr *taddr6;
 1461         struct dadq *dp;
 1462         int duplicate;
 1463 
 1464         if (ifa == NULL)
 1465                 panic("ifa == NULL in nd6_dad_ns_input");
 1466 
 1467         ia = (struct in6_ifaddr *)ifa;
 1468         ifp = ifa->ifa_ifp;
 1469         taddr6 = &ia->ia_addr.sin6_addr;
 1470         duplicate = 0;
 1471         dp = nd6_dad_find(ifa);
 1472 
 1473         /* Quickhack - completely ignore DAD NS packets */
 1474         if (V_dad_ignore_ns) {
 1475                 char ip6buf[INET6_ADDRSTRLEN];
 1476                 nd6log((LOG_INFO,
 1477                     "nd6_dad_ns_input: ignoring DAD NS packet for "
 1478                     "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6),
 1479                     if_name(ifa->ifa_ifp)));
 1480                 return;
 1481         }
 1482 
 1483         /*
 1484          * if I'm yet to start DAD, someone else started using this address
 1485          * first.  I have a duplicate and you win.
 1486          */
 1487         if (dp == NULL || dp->dad_ns_ocount == 0)
 1488                 duplicate++;
 1489 
 1490         /* XXX more checks for loopback situation - see nd6_dad_timer too */
 1491 
 1492         if (duplicate) {
 1493                 dp = NULL;      /* will be freed in nd6_dad_duplicated() */
 1494                 nd6_dad_duplicated(ifa);
 1495         } else {
 1496                 /*
 1497                  * not sure if I got a duplicate.
 1498                  * increment ns count and see what happens.
 1499                  */
 1500                 if (dp)
 1501                         dp->dad_ns_icount++;
 1502         }
 1503 }
 1504 
 1505 static void
 1506 nd6_dad_na_input(struct ifaddr *ifa)
 1507 {
 1508         struct dadq *dp;
 1509 
 1510         if (ifa == NULL)
 1511                 panic("ifa == NULL in nd6_dad_na_input");
 1512 
 1513         dp = nd6_dad_find(ifa);
 1514         if (dp)
 1515                 dp->dad_na_icount++;
 1516 
 1517         /* remove the address. */
 1518         nd6_dad_duplicated(ifa);
 1519 }

Cache object: 7f7748293bc8a72562912d4ba1dd61cc


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