The Design and Implementation of the FreeBSD Operating System, Second Edition
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sys/netinet6/nd6_nbr.c

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    1 /*      $NetBSD: nd6_nbr.c,v 1.53 2004/02/10 20:57:20 itojun Exp $      */
    2 /*      $KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 jinmei Exp $        */
    3 
    4 /*
    5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 3. Neither the name of the project nor the names of its contributors
   17  *    may be used to endorse or promote products derived from this software
   18  *    without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   30  * SUCH DAMAGE.
   31  */
   32 
   33 #include <sys/cdefs.h>
   34 __KERNEL_RCSID(0, "$NetBSD: nd6_nbr.c,v 1.53 2004/02/10 20:57:20 itojun Exp $");
   35 
   36 #include "opt_inet.h"
   37 #include "opt_ipsec.h"
   38 
   39 #include <sys/param.h>
   40 #include <sys/systm.h>
   41 #include <sys/malloc.h>
   42 #include <sys/mbuf.h>
   43 #include <sys/socket.h>
   44 #include <sys/sockio.h>
   45 #include <sys/time.h>
   46 #include <sys/kernel.h>
   47 #include <sys/errno.h>
   48 #include <sys/ioctl.h>
   49 #include <sys/syslog.h>
   50 #include <sys/queue.h>
   51 #include <sys/callout.h>
   52 
   53 #include <net/if.h>
   54 #include <net/if_types.h>
   55 #include <net/if_dl.h>
   56 #include <net/route.h>
   57 
   58 #include <netinet/in.h>
   59 #include <netinet/in_var.h>
   60 #include <netinet6/in6_var.h>
   61 #include <netinet/ip6.h>
   62 #include <netinet6/ip6_var.h>
   63 #include <netinet6/nd6.h>
   64 #include <netinet/icmp6.h>
   65 
   66 #ifdef IPSEC
   67 #include <netinet6/ipsec.h>
   68 #endif
   69 
   70 #include <net/net_osdep.h>
   71 
   72 #define SDL(s) ((struct sockaddr_dl *)s)
   73 
   74 struct dadq;
   75 static struct dadq *nd6_dad_find __P((struct ifaddr *));
   76 static void nd6_dad_starttimer __P((struct dadq *, int));
   77 static void nd6_dad_stoptimer __P((struct dadq *));
   78 static void nd6_dad_timer __P((struct ifaddr *));
   79 static void nd6_dad_ns_output __P((struct dadq *, struct ifaddr *));
   80 static void nd6_dad_ns_input __P((struct ifaddr *));
   81 static void nd6_dad_na_input __P((struct ifaddr *));
   82 
   83 static int dad_ignore_ns = 0;   /* ignore NS in DAD - specwise incorrect*/
   84 static int dad_maxtry = 15;     /* max # of *tries* to transmit DAD packet */
   85 
   86 /*
   87  * Input an Neighbor Solicitation Message.
   88  *
   89  * Based on RFC 2461
   90  * Based on RFC 2462 (duplicated address detection)
   91  */
   92 void
   93 nd6_ns_input(m, off, icmp6len)
   94         struct mbuf *m;
   95         int off, icmp6len;
   96 {
   97         struct ifnet *ifp = m->m_pkthdr.rcvif;
   98         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   99         struct nd_neighbor_solicit *nd_ns;
  100         struct in6_addr saddr6 = ip6->ip6_src;
  101         struct in6_addr daddr6 = ip6->ip6_dst;
  102         struct in6_addr taddr6;
  103         struct in6_addr myaddr6;
  104         char *lladdr = NULL;
  105         struct ifaddr *ifa;
  106         int lladdrlen = 0;
  107         int anycast = 0, proxy = 0, tentative = 0;
  108         int router = ip6_forwarding;
  109         int tlladdr;
  110         union nd_opts ndopts;
  111         struct sockaddr_dl *proxydl = NULL;
  112 
  113         IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
  114         if (nd_ns == NULL) {
  115                 icmp6stat.icp6s_tooshort++;
  116                 return;
  117         }
  118         ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
  119         taddr6 = nd_ns->nd_ns_target;
  120 
  121         if (ip6->ip6_hlim != 255) {
  122                 nd6log((LOG_ERR,
  123                     "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
  124                     ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
  125                     ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
  126                 goto bad;
  127         }
  128 
  129         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
  130                 /* dst has to be solicited node multicast address. */
  131                 /* don't check ifindex portion */
  132                 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
  133                     daddr6.s6_addr32[1] == 0 &&
  134                     daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
  135                     daddr6.s6_addr8[12] == 0xff) {
  136                         ; /* good */
  137                 } else {
  138                         nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
  139                             "(wrong ip6 dst)\n"));
  140                         goto bad;
  141                 }
  142         }
  143 
  144         if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
  145                 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
  146                 goto bad;
  147         }
  148 
  149         if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
  150                 taddr6.s6_addr16[1] = htons(ifp->if_index);
  151 
  152         icmp6len -= sizeof(*nd_ns);
  153         nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
  154         if (nd6_options(&ndopts) < 0) {
  155                 nd6log((LOG_INFO,
  156                     "nd6_ns_input: invalid ND option, ignored\n"));
  157                 /* nd6_options have incremented stats */
  158                 goto freeit;
  159         }
  160 
  161         if (ndopts.nd_opts_src_lladdr) {
  162                 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
  163                 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
  164         }
  165 
  166         if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
  167                 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
  168                     "(link-layer address option)\n"));
  169                 goto bad;
  170         }
  171 
  172         /*
  173          * Attaching target link-layer address to the NA?
  174          * (RFC 2461 7.2.4)
  175          *
  176          * NS IP dst is unicast/anycast                 MUST NOT add
  177          * NS IP dst is solicited-node multicast        MUST add
  178          *
  179          * In implementation, we add target link-layer address by default.
  180          * We do not add one in MUST NOT cases.
  181          */
  182 #if 0 /* too much! */
  183         ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6);
  184         if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST))
  185                 tlladdr = 0;
  186         else
  187 #endif
  188         if (!IN6_IS_ADDR_MULTICAST(&daddr6))
  189                 tlladdr = 0;
  190         else
  191                 tlladdr = 1;
  192 
  193         /*
  194          * Target address (taddr6) must be either:
  195          * (1) Valid unicast/anycast address for my receiving interface,
  196          * (2) Unicast address for which I'm offering proxy service, or
  197          * (3) "tentative" address on which DAD is being performed.
  198          */
  199         /* (1) and (3) check. */
  200         ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
  201 
  202         /* (2) check. */
  203         if (!ifa) {
  204                 struct rtentry *rt;
  205                 struct sockaddr_in6 tsin6;
  206 
  207                 bzero(&tsin6, sizeof tsin6);
  208                 tsin6.sin6_len = sizeof(struct sockaddr_in6);
  209                 tsin6.sin6_family = AF_INET6;
  210                 tsin6.sin6_addr = taddr6;
  211 
  212                 rt = rtalloc1((struct sockaddr *)&tsin6, 0);
  213                 if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
  214                     rt->rt_gateway->sa_family == AF_LINK) {
  215                         /*
  216                          * proxy NDP for single entry
  217                          */
  218                         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
  219                                 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
  220                         if (ifa) {
  221                                 proxy = 1;
  222                                 proxydl = SDL(rt->rt_gateway);
  223                                 router = 0;     /* XXX */
  224                         }
  225                 }
  226                 if (rt)
  227                         rtfree(rt);
  228         }
  229         if (!ifa) {
  230                 /*
  231                  * We've got an NS packet, and we don't have that adddress
  232                  * assigned for us.  We MUST silently ignore it.
  233                  * See RFC2461 7.2.3.
  234                  */
  235                 goto freeit;
  236         }
  237         myaddr6 = *IFA_IN6(ifa);
  238         anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
  239         tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
  240         if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
  241                 goto freeit;
  242 
  243         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  244                 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
  245                     "(if %d, NS packet %d)\n",
  246                     ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2));
  247                 goto bad;
  248         }
  249 
  250         if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
  251                 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
  252                     ip6_sprintf(&saddr6)));
  253                 goto freeit;
  254         }
  255 
  256         /*
  257          * We have neighbor solicitation packet, with target address equals to
  258          * one of my tentative address.
  259          *
  260          * src addr     how to process?
  261          * ---          ---
  262          * multicast    of course, invalid (rejected in ip6_input)
  263          * unicast      somebody is doing address resolution -> ignore
  264          * unspec       dup address detection
  265          *
  266          * The processing is defined in RFC 2462.
  267          */
  268         if (tentative) {
  269                 /*
  270                  * If source address is unspecified address, it is for
  271                  * duplicated address detection.
  272                  *
  273                  * If not, the packet is for addess resolution;
  274                  * silently ignore it.
  275                  */
  276                 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
  277                         nd6_dad_ns_input(ifa);
  278 
  279                 goto freeit;
  280         }
  281 
  282         /*
  283          * If the source address is unspecified address, entries must not
  284          * be created or updated.
  285          * It looks that sender is performing DAD.  Output NA toward
  286          * all-node multicast address, to tell the sender that I'm using
  287          * the address.
  288          * S bit ("solicited") must be zero.
  289          */
  290         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
  291                 saddr6 = in6addr_linklocal_allnodes;
  292                 saddr6.s6_addr16[1] = htons(ifp->if_index);
  293                 nd6_na_output(ifp, &saddr6, &taddr6,
  294                     ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  295                     (router ? ND_NA_FLAG_ROUTER : 0),
  296                     tlladdr, (struct sockaddr *)proxydl);
  297                 goto freeit;
  298         }
  299 
  300         nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0);
  301 
  302         nd6_na_output(ifp, &saddr6, &taddr6,
  303             ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  304             (router ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
  305             tlladdr, (struct sockaddr *)proxydl);
  306  freeit:
  307         m_freem(m);
  308         return;
  309 
  310  bad:
  311         nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)));
  312         nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)));
  313         nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)));
  314         icmp6stat.icp6s_badns++;
  315         m_freem(m);
  316 }
  317 
  318 /*
  319  * Output an Neighbor Solicitation Message. Caller specifies:
  320  *      - ICMP6 header source IP6 address
  321  *      - ND6 header target IP6 address
  322  *      - ND6 header source datalink address
  323  *
  324  * Based on RFC 2461
  325  * Based on RFC 2462 (duplicated address detection)
  326  */
  327 void
  328 nd6_ns_output(ifp, daddr6, taddr6, ln, dad)
  329         struct ifnet *ifp;
  330         const struct in6_addr *daddr6, *taddr6;
  331         struct llinfo_nd6 *ln;  /* for source address determination */
  332         int dad;        /* duplicated address detection */
  333 {
  334         struct mbuf *m;
  335         struct ip6_hdr *ip6;
  336         struct nd_neighbor_solicit *nd_ns;
  337         struct sockaddr_in6 src_sa, dst_sa;
  338         struct ip6_moptions im6o;
  339         int icmp6len;
  340         int maxlen;
  341         caddr_t mac;
  342         struct route_in6 ro;
  343 
  344         bzero(&ro, sizeof(ro));
  345 
  346         if (IN6_IS_ADDR_MULTICAST(taddr6))
  347                 return;
  348 
  349         /* estimate the size of message */
  350         maxlen = sizeof(*ip6) + sizeof(*nd_ns);
  351         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  352 #ifdef DIAGNOSTIC
  353         if (max_linkhdr + maxlen >= MCLBYTES) {
  354                 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
  355                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  356                 panic("nd6_ns_output: insufficient MCLBYTES");
  357                 /* NOTREACHED */
  358         }
  359 #endif
  360 
  361         MGETHDR(m, M_DONTWAIT, MT_DATA);
  362         if (m && max_linkhdr + maxlen >= MHLEN) {
  363                 MCLGET(m, M_DONTWAIT);
  364                 if ((m->m_flags & M_EXT) == 0) {
  365                         m_free(m);
  366                         m = NULL;
  367                 }
  368         }
  369         if (m == NULL)
  370                 return;
  371         m->m_pkthdr.rcvif = NULL;
  372 
  373         if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
  374                 m->m_flags |= M_MCAST;
  375                 im6o.im6o_multicast_ifp = ifp;
  376                 im6o.im6o_multicast_hlim = 255;
  377                 im6o.im6o_multicast_loop = 0;
  378         }
  379 
  380         icmp6len = sizeof(*nd_ns);
  381         m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
  382         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  383 
  384         /* fill neighbor solicitation packet */
  385         ip6 = mtod(m, struct ip6_hdr *);
  386         ip6->ip6_flow = 0;
  387         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  388         ip6->ip6_vfc |= IPV6_VERSION;
  389         /* ip6->ip6_plen will be set later */
  390         ip6->ip6_nxt = IPPROTO_ICMPV6;
  391         ip6->ip6_hlim = 255;
  392         /* determine the source and destination addresses */
  393         bzero(&src_sa, sizeof(src_sa));
  394         bzero(&dst_sa, sizeof(dst_sa));
  395         src_sa.sin6_family = dst_sa.sin6_family = AF_INET6;
  396         src_sa.sin6_len = dst_sa.sin6_len = sizeof(struct sockaddr_in6);
  397         if (daddr6)
  398                 dst_sa.sin6_addr = *daddr6;
  399         else {
  400                 dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  401                 dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
  402                 dst_sa.sin6_addr.s6_addr32[1] = 0;
  403                 dst_sa.sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
  404                 dst_sa.sin6_addr.s6_addr32[3] = taddr6->s6_addr32[3];
  405                 dst_sa.sin6_addr.s6_addr8[12] = 0xff;
  406         }
  407         ip6->ip6_dst = dst_sa.sin6_addr;
  408         if (!dad) {
  409                 /*
  410                  * RFC2461 7.2.2:
  411                  * "If the source address of the packet prompting the
  412                  * solicitation is the same as one of the addresses assigned
  413                  * to the outgoing interface, that address SHOULD be placed
  414                  * in the IP Source Address of the outgoing solicitation.
  415                  * Otherwise, any one of the addresses assigned to the
  416                  * interface should be used."
  417                  *
  418                  * We use the source address for the prompting packet
  419                  * (saddr6), if:
  420                  * - saddr6 is given from the caller (by giving "ln"), and
  421                  * - saddr6 belongs to the outgoing interface.
  422                  * Otherwise, we perform the source address selection as usual.
  423                  */
  424                 struct ip6_hdr *hip6;           /* hold ip6 */
  425                 struct in6_addr *saddr6;
  426 
  427                 if (ln && ln->ln_hold) {
  428                         hip6 = mtod(ln->ln_hold, struct ip6_hdr *);
  429                         /* XXX pullup? */
  430                         if (sizeof(*hip6) < ln->ln_hold->m_len)
  431                                 saddr6 = &hip6->ip6_src;
  432                         else
  433                                 saddr6 = NULL;
  434                 } else
  435                         saddr6 = NULL;
  436                 if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6))
  437                         src_sa.sin6_addr = *saddr6;
  438                 else {
  439                         struct in6_addr *src0;
  440                         int error;
  441 
  442                         bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
  443                         src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL,
  444                             &error);
  445                         if (src0 == NULL) {
  446                                 nd6log((LOG_DEBUG,
  447                                     "nd6_ns_output: source can't be "
  448                                     "determined: dst=%s, error=%d\n",
  449                                     ip6_sprintf(&dst_sa.sin6_addr), error));
  450                                 goto bad;
  451                         }
  452                         src_sa.sin6_addr = *src0;
  453                 }
  454         } else {
  455                 /*
  456                  * Source address for DAD packet must always be IPv6
  457                  * unspecified address. (0::0)
  458                  * We actually don't have to 0-clear the address (we did it
  459                  * above), but we do so here explicitly to make the intention
  460                  * clearer.
  461                  */
  462                 bzero(&src_sa.sin6_addr, sizeof(src_sa.sin6_addr));
  463         }
  464         ip6->ip6_src = src_sa.sin6_addr;
  465         nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
  466         nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
  467         nd_ns->nd_ns_code = 0;
  468         nd_ns->nd_ns_reserved = 0;
  469         nd_ns->nd_ns_target = *taddr6;
  470 
  471         if (IN6_IS_SCOPE_LINKLOCAL(&nd_ns->nd_ns_target))
  472                 nd_ns->nd_ns_target.s6_addr16[1] = 0;
  473 
  474         /*
  475          * Add source link-layer address option.
  476          *
  477          *                              spec            implementation
  478          *                              ---             ---
  479          * DAD packet                   MUST NOT        do not add the option
  480          * there's no link layer address:
  481          *                              impossible      do not add the option
  482          * there's link layer address:
  483          *      Multicast NS            MUST add one    add the option
  484          *      Unicast NS              SHOULD add one  add the option
  485          */
  486         if (!dad && (mac = nd6_ifptomac(ifp))) {
  487                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
  488                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
  489                 /* 8 byte alignments... */
  490                 optlen = (optlen + 7) & ~7;
  491 
  492                 m->m_pkthdr.len += optlen;
  493                 m->m_len += optlen;
  494                 icmp6len += optlen;
  495                 bzero((caddr_t)nd_opt, optlen);
  496                 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
  497                 nd_opt->nd_opt_len = optlen >> 3;
  498                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
  499         }
  500 
  501         ip6->ip6_plen = htons((u_int16_t)icmp6len);
  502         nd_ns->nd_ns_cksum = 0;
  503         nd_ns->nd_ns_cksum =
  504             in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
  505 
  506         ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, 
  507             &im6o, (struct socket *)NULL, NULL);
  508         icmp6_ifstat_inc(ifp, ifs6_out_msg);
  509         icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
  510         icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++;
  511 
  512         if (ro.ro_rt) {         /* we don't cache this route. */
  513                 RTFREE(ro.ro_rt);
  514         }
  515         return;
  516 
  517   bad:
  518         if (ro.ro_rt) {
  519                 RTFREE(ro.ro_rt);
  520         }
  521         m_freem(m);
  522         return;
  523 }
  524 
  525 /*
  526  * Neighbor advertisement input handling.
  527  *
  528  * Based on RFC 2461
  529  * Based on RFC 2462 (duplicated address detection)
  530  *
  531  * the following items are not implemented yet:
  532  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  533  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  534  */
  535 void
  536 nd6_na_input(m, off, icmp6len)
  537         struct mbuf *m;
  538         int off, icmp6len;
  539 {
  540         struct ifnet *ifp = m->m_pkthdr.rcvif;
  541         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  542         struct nd_neighbor_advert *nd_na;
  543 #if 0
  544         struct in6_addr saddr6 = ip6->ip6_src;
  545 #endif
  546         struct in6_addr daddr6 = ip6->ip6_dst;
  547         struct in6_addr taddr6;
  548         int flags;
  549         int is_router;
  550         int is_solicited;
  551         int is_override;
  552         char *lladdr = NULL;
  553         int lladdrlen = 0;
  554         struct ifaddr *ifa;
  555         struct llinfo_nd6 *ln;
  556         struct rtentry *rt;
  557         struct sockaddr_dl *sdl;
  558         union nd_opts ndopts;
  559 
  560         if (ip6->ip6_hlim != 255) {
  561                 nd6log((LOG_ERR,
  562                     "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
  563                     ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
  564                     ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
  565                 goto bad;
  566         }
  567 
  568         IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
  569         if (nd_na == NULL) {
  570                 icmp6stat.icp6s_tooshort++;
  571                 return;
  572         }
  573         taddr6 = nd_na->nd_na_target;
  574         flags = nd_na->nd_na_flags_reserved;
  575         is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
  576         is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
  577         is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
  578 
  579         if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
  580                 taddr6.s6_addr16[1] = htons(ifp->if_index);
  581 
  582         if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
  583                 nd6log((LOG_ERR,
  584                     "nd6_na_input: invalid target address %s\n",
  585                     ip6_sprintf(&taddr6)));
  586                 goto bad;
  587         }
  588         if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) {
  589                 nd6log((LOG_ERR,
  590                     "nd6_na_input: a solicited adv is multicasted\n"));
  591                 goto bad;
  592         }
  593 
  594         icmp6len -= sizeof(*nd_na);
  595         nd6_option_init(nd_na + 1, icmp6len, &ndopts);
  596         if (nd6_options(&ndopts) < 0) {
  597                 nd6log((LOG_INFO,
  598                     "nd6_na_input: invalid ND option, ignored\n"));
  599                 /* nd6_options have incremented stats */
  600                 goto freeit;
  601         }
  602 
  603         if (ndopts.nd_opts_tgt_lladdr) {
  604                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
  605                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
  606         }
  607 
  608         ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
  609 
  610         /*
  611          * Target address matches one of my interface address.
  612          *
  613          * If my address is tentative, this means that there's somebody
  614          * already using the same address as mine.  This indicates DAD failure.
  615          * This is defined in RFC 2462.
  616          *
  617          * Otherwise, process as defined in RFC 2461.
  618          */
  619         if (ifa
  620          && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
  621                 nd6_dad_na_input(ifa);
  622                 goto freeit;
  623         }
  624 
  625         /* Just for safety, maybe unnecessary. */
  626         if (ifa) {
  627                 log(LOG_ERR,
  628                     "nd6_na_input: duplicate IP6 address %s\n",
  629                     ip6_sprintf(&taddr6));
  630                 goto freeit;
  631         }
  632 
  633         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  634                 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
  635                     "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6),
  636                     ifp->if_addrlen, lladdrlen - 2));
  637                 goto bad;
  638         }
  639 
  640         /*
  641          * If no neighbor cache entry is found, NA SHOULD silently be
  642          * discarded.
  643          */
  644         rt = nd6_lookup(&taddr6, 0, ifp);
  645         if ((rt == NULL) ||
  646            ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) ||
  647            ((sdl = SDL(rt->rt_gateway)) == NULL))
  648                 goto freeit;
  649 
  650         if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
  651                 /*
  652                  * If the link-layer has address, and no lladdr option came,
  653                  * discard the packet.
  654                  */
  655                 if (ifp->if_addrlen && !lladdr)
  656                         goto freeit;
  657 
  658                 /*
  659                  * Record link-layer address, and update the state.
  660                  */
  661                 sdl->sdl_alen = ifp->if_addrlen;
  662                 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
  663                 if (is_solicited) {
  664                         ln->ln_state = ND6_LLINFO_REACHABLE;
  665                         ln->ln_byhint = 0;
  666                         if (!ND6_LLINFO_PERMANENT(ln)) {
  667                                 nd6_llinfo_settimer(ln,
  668                                     (long)ND_IFINFO(rt->rt_ifp)->reachable * hz);
  669                         }
  670                 } else {
  671                         ln->ln_state = ND6_LLINFO_STALE;
  672                         nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
  673                 }
  674                 if ((ln->ln_router = is_router) != 0) {
  675                         /*
  676                          * This means a router's state has changed from
  677                          * non-reachable to probably reachable, and might
  678                          * affect the status of associated prefixes..
  679                          */
  680                         pfxlist_onlink_check();
  681                 }
  682         } else {
  683                 int llchange;
  684 
  685                 /*
  686                  * Check if the link-layer address has changed or not.
  687                  */
  688                 if (!lladdr)
  689                         llchange = 0;
  690                 else {
  691                         if (sdl->sdl_alen) {
  692                                 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
  693                                         llchange = 1;
  694                                 else
  695                                         llchange = 0;
  696                         } else
  697                                 llchange = 1;
  698                 }
  699 
  700                 /*
  701                  * This is VERY complex.  Look at it with care.
  702                  *
  703                  * override solicit lladdr llchange     action
  704                  *                                      (L: record lladdr)
  705                  *
  706                  *      0       0       n       --      (2c)
  707                  *      0       0       y       n       (2b) L
  708                  *      0       0       y       y       (1)    REACHABLE->STALE
  709                  *      0       1       n       --      (2c)   *->REACHABLE
  710                  *      0       1       y       n       (2b) L *->REACHABLE
  711                  *      0       1       y       y       (1)    REACHABLE->STALE
  712                  *      1       0       n       --      (2a)
  713                  *      1       0       y       n       (2a) L
  714                  *      1       0       y       y       (2a) L *->STALE
  715                  *      1       1       n       --      (2a)   *->REACHABLE
  716                  *      1       1       y       n       (2a) L *->REACHABLE
  717                  *      1       1       y       y       (2a) L *->REACHABLE
  718                  */
  719                 if (!is_override && (lladdr && llchange)) {        /* (1) */
  720                         /*
  721                          * If state is REACHABLE, make it STALE.
  722                          * no other updates should be done.
  723                          */
  724                         if (ln->ln_state == ND6_LLINFO_REACHABLE) {
  725                                 ln->ln_state = ND6_LLINFO_STALE;
  726                                 nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
  727                         }
  728                         goto freeit;
  729                 } else if (is_override                             /* (2a) */
  730                         || (!is_override && (lladdr && !llchange)) /* (2b) */
  731                         || !lladdr) {                              /* (2c) */
  732                         /*
  733                          * Update link-local address, if any.
  734                          */
  735                         if (lladdr) {
  736                                 sdl->sdl_alen = ifp->if_addrlen;
  737                                 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
  738                         }
  739 
  740                         /*
  741                          * If solicited, make the state REACHABLE.
  742                          * If not solicited and the link-layer address was
  743                          * changed, make it STALE.
  744                          */
  745                         if (is_solicited) {
  746                                 ln->ln_state = ND6_LLINFO_REACHABLE;
  747                                 ln->ln_byhint = 0;
  748                                 if (!ND6_LLINFO_PERMANENT(ln)) {
  749                                         nd6_llinfo_settimer(ln,
  750                                             (long)ND_IFINFO(ifp)->reachable * hz);
  751                                 }
  752                         } else {
  753                                 if (lladdr && llchange) {
  754                                         ln->ln_state = ND6_LLINFO_STALE;
  755                                         nd6_llinfo_settimer(ln,
  756                                             (long)nd6_gctimer * hz);
  757                                 }
  758                         }
  759                 }
  760 
  761                 if (ln->ln_router && !is_router) {
  762                         /*
  763                          * The peer dropped the router flag.
  764                          * Remove the sender from the Default Router List and
  765                          * update the Destination Cache entries.
  766                          */
  767                         struct nd_defrouter *dr;
  768                         struct in6_addr *in6;
  769                         int s;
  770 
  771                         in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
  772 
  773                         /*
  774                          * Lock to protect the default router list.
  775                          * XXX: this might be unnecessary, since this function
  776                          * is only called under the network software interrupt
  777                          * context.  However, we keep it just for safety.
  778                          */
  779                         s = splsoftnet();
  780                         dr = defrouter_lookup(in6, rt->rt_ifp);
  781                         if (dr)
  782                                 defrtrlist_del(dr);
  783                         else if (!ip6_forwarding) {
  784                                 /*
  785                                  * Even if the neighbor is not in the default
  786                                  * router list, the neighbor may be used
  787                                  * as a next hop for some destinations
  788                                  * (e.g. redirect case). So we must
  789                                  * call rt6_flush explicitly.
  790                                  */
  791                                 rt6_flush(&ip6->ip6_src, rt->rt_ifp);
  792                         }
  793                         splx(s);
  794                 }
  795                 ln->ln_router = is_router;
  796         }
  797         rt->rt_flags &= ~RTF_REJECT;
  798         ln->ln_asked = 0;
  799         if (ln->ln_hold) {
  800                 /*
  801                  * we assume ifp is not a loopback here, so just set the 2nd
  802                  * argument as the 1st one.
  803                  */
  804                 nd6_output(ifp, ifp, ln->ln_hold,
  805                     (struct sockaddr_in6 *)rt_key(rt), rt);
  806                 ln->ln_hold = NULL;
  807         }
  808 
  809  freeit:
  810         m_freem(m);
  811         return;
  812 
  813  bad:
  814         icmp6stat.icp6s_badna++;
  815         m_freem(m);
  816 }
  817 
  818 /*
  819  * Neighbor advertisement output handling.
  820  *
  821  * Based on RFC 2461
  822  *
  823  * the following items are not implemented yet:
  824  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  825  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  826  */
  827 void
  828 nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr, sdl0)
  829         struct ifnet *ifp;
  830         const struct in6_addr *daddr6, *taddr6;
  831         u_long flags;
  832         int tlladdr;            /* 1 if include target link-layer address */
  833         struct sockaddr *sdl0;  /* sockaddr_dl (= proxy NA) or NULL */
  834 {
  835         struct mbuf *m;
  836         struct ip6_hdr *ip6;
  837         struct nd_neighbor_advert *nd_na;
  838         struct ip6_moptions im6o;
  839         struct sockaddr_in6 dst_sa;
  840         struct in6_addr *src0;
  841         int icmp6len, maxlen, error;
  842         caddr_t mac;
  843         struct route_in6 ro;
  844 
  845         mac = NULL;
  846         bzero(&ro, sizeof(ro));
  847 
  848         /* estimate the size of message */
  849         maxlen = sizeof(*ip6) + sizeof(*nd_na);
  850         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  851 #ifdef DIAGNOSTIC
  852         if (max_linkhdr + maxlen >= MCLBYTES) {
  853                 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
  854                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  855                 panic("nd6_na_output: insufficient MCLBYTES");
  856                 /* NOTREACHED */
  857         }
  858 #endif
  859 
  860         MGETHDR(m, M_DONTWAIT, MT_DATA);
  861         if (m && max_linkhdr + maxlen >= MHLEN) {
  862                 MCLGET(m, M_DONTWAIT);
  863                 if ((m->m_flags & M_EXT) == 0) {
  864                         m_free(m);
  865                         m = NULL;
  866                 }
  867         }
  868         if (m == NULL)
  869                 return;
  870         m->m_pkthdr.rcvif = NULL;
  871 
  872         if (IN6_IS_ADDR_MULTICAST(daddr6)) {
  873                 m->m_flags |= M_MCAST;
  874                 im6o.im6o_multicast_ifp = ifp;
  875                 im6o.im6o_multicast_hlim = 255;
  876                 im6o.im6o_multicast_loop = 0;
  877         }
  878 
  879         icmp6len = sizeof(*nd_na);
  880         m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
  881         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  882 
  883         /* fill neighbor advertisement packet */
  884         ip6 = mtod(m, struct ip6_hdr *);
  885         ip6->ip6_flow = 0;
  886         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  887         ip6->ip6_vfc |= IPV6_VERSION;
  888         ip6->ip6_nxt = IPPROTO_ICMPV6;
  889         ip6->ip6_hlim = 255;
  890         bzero(&dst_sa, sizeof(dst_sa));
  891         dst_sa.sin6_len = sizeof(struct sockaddr_in6);
  892         dst_sa.sin6_family = AF_INET6;
  893         dst_sa.sin6_addr = *daddr6;
  894         if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) {
  895                 /* reply to DAD */
  896                 dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  897                 dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
  898                 dst_sa.sin6_addr.s6_addr32[1] = 0;
  899                 dst_sa.sin6_addr.s6_addr32[2] = 0;
  900                 dst_sa.sin6_addr.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
  901 
  902                 flags &= ~ND_NA_FLAG_SOLICITED;
  903         }
  904         ip6->ip6_dst = dst_sa.sin6_addr;
  905 
  906         /*
  907          * Select a source whose scope is the same as that of the dest.
  908          */
  909         bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
  910         src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &error);
  911         if (src0 == NULL) {
  912                 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
  913                     "determined: dst=%s, error=%d\n",
  914                     ip6_sprintf(&dst_sa.sin6_addr), error));
  915                 goto bad;
  916         }
  917         ip6->ip6_src = *src0;
  918         nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
  919         nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
  920         nd_na->nd_na_code = 0;
  921         nd_na->nd_na_target = *taddr6;
  922         if (IN6_IS_SCOPE_LINKLOCAL(&nd_na->nd_na_target))
  923                 nd_na->nd_na_target.s6_addr16[1] = 0;
  924 
  925         /*
  926          * "tlladdr" indicates NS's condition for adding tlladdr or not.
  927          * see nd6_ns_input() for details.
  928          * Basically, if NS packet is sent to unicast/anycast addr,
  929          * target lladdr option SHOULD NOT be included.
  930          */
  931         if (tlladdr) {
  932                 /*
  933                  * sdl0 != NULL indicates proxy NA.  If we do proxy, use
  934                  * lladdr in sdl0.  If we are not proxying (sending NA for
  935                  * my address) use lladdr configured for the interface.
  936                  */
  937                 if (sdl0 == NULL)
  938                         mac = nd6_ifptomac(ifp);
  939                 else if (sdl0->sa_family == AF_LINK) {
  940                         struct sockaddr_dl *sdl;
  941                         sdl = (struct sockaddr_dl *)sdl0;
  942                         if (sdl->sdl_alen == ifp->if_addrlen)
  943                                 mac = LLADDR(sdl);
  944                 }
  945         }
  946         if (tlladdr && mac) {
  947                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
  948                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
  949 
  950                 /* roundup to 8 bytes alignment! */
  951                 optlen = (optlen + 7) & ~7;
  952 
  953                 m->m_pkthdr.len += optlen;
  954                 m->m_len += optlen;
  955                 icmp6len += optlen;
  956                 bzero((caddr_t)nd_opt, optlen);
  957                 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
  958                 nd_opt->nd_opt_len = optlen >> 3;
  959                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
  960         } else
  961                 flags &= ~ND_NA_FLAG_OVERRIDE;
  962 
  963         ip6->ip6_plen = htons((u_int16_t)icmp6len);
  964         nd_na->nd_na_flags_reserved = flags;
  965         nd_na->nd_na_cksum = 0;
  966         nd_na->nd_na_cksum =
  967             in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
  968 
  969         ip6_output(m, NULL, NULL, 0, &im6o, (struct socket *)NULL, NULL);
  970 
  971         icmp6_ifstat_inc(ifp, ifs6_out_msg);
  972         icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
  973         icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++;
  974 
  975         if (ro.ro_rt) {         /* we don't cache this route. */
  976                 RTFREE(ro.ro_rt);
  977         }
  978         return;
  979 
  980   bad:
  981         if (ro.ro_rt) {
  982                 RTFREE(ro.ro_rt);
  983         }
  984         m_freem(m);
  985         return;
  986 }
  987 
  988 caddr_t
  989 nd6_ifptomac(ifp)
  990         struct ifnet *ifp;
  991 {
  992         switch (ifp->if_type) {
  993         case IFT_ARCNET:
  994         case IFT_ETHER:
  995         case IFT_FDDI:
  996         case IFT_IEEE1394:
  997         case IFT_PROPVIRTUAL:
  998         case IFT_L2VLAN:
  999         case IFT_IEEE80211:
 1000                 return LLADDR(ifp->if_sadl);
 1001         default:
 1002                 return NULL;
 1003         }
 1004 }
 1005 
 1006 TAILQ_HEAD(dadq_head, dadq);
 1007 struct dadq {
 1008         TAILQ_ENTRY(dadq) dad_list;
 1009         struct ifaddr *dad_ifa;
 1010         int dad_count;          /* max NS to send */
 1011         int dad_ns_tcount;      /* # of trials to send NS */
 1012         int dad_ns_ocount;      /* NS sent so far */
 1013         int dad_ns_icount;
 1014         int dad_na_icount;
 1015         struct callout dad_timer_ch;
 1016 };
 1017 
 1018 static struct dadq_head dadq;
 1019 static int dad_init = 0;
 1020 
 1021 static struct dadq *
 1022 nd6_dad_find(ifa)
 1023         struct ifaddr *ifa;
 1024 {
 1025         struct dadq *dp;
 1026 
 1027         for (dp = dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
 1028                 if (dp->dad_ifa == ifa)
 1029                         return dp;
 1030         }
 1031         return NULL;
 1032 }
 1033 
 1034 static void
 1035 nd6_dad_starttimer(dp, ticks)
 1036         struct dadq *dp;
 1037         int ticks;
 1038 {
 1039 
 1040         callout_reset(&dp->dad_timer_ch, ticks,
 1041             (void (*) __P((void *)))nd6_dad_timer, (void *)dp->dad_ifa);
 1042 }
 1043 
 1044 static void
 1045 nd6_dad_stoptimer(dp)
 1046         struct dadq *dp;
 1047 {
 1048 
 1049         callout_stop(&dp->dad_timer_ch);
 1050 }
 1051 
 1052 /*
 1053  * Start Duplicated Address Detection (DAD) for specified interface address.
 1054  */
 1055 void
 1056 nd6_dad_start(ifa, tick)
 1057         struct ifaddr *ifa;
 1058         int *tick;      /* minimum delay ticks for IFF_UP event */
 1059 {
 1060         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1061         struct dadq *dp;
 1062 
 1063         if (!dad_init) {
 1064                 TAILQ_INIT(&dadq);
 1065                 dad_init++;
 1066         }
 1067 
 1068         /*
 1069          * If we don't need DAD, don't do it.
 1070          * There are several cases:
 1071          * - DAD is disabled (ip6_dad_count == 0)
 1072          * - the interface address is anycast
 1073          */
 1074         if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
 1075                 log(LOG_DEBUG,
 1076                         "nd6_dad_start: called with non-tentative address "
 1077                         "%s(%s)\n",
 1078                         ip6_sprintf(&ia->ia_addr.sin6_addr),
 1079                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1080                 return;
 1081         }
 1082         if (ia->ia6_flags & IN6_IFF_ANYCAST) {
 1083                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1084                 return;
 1085         }
 1086         if (!ip6_dad_count) {
 1087                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1088                 return;
 1089         }
 1090         if (!ifa->ifa_ifp)
 1091                 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
 1092         if (!(ifa->ifa_ifp->if_flags & IFF_UP))
 1093                 return;
 1094         if (nd6_dad_find(ifa) != NULL) {
 1095                 /* DAD already in progress */
 1096                 return;
 1097         }
 1098 
 1099         dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
 1100         if (dp == NULL) {
 1101                 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
 1102                         "%s(%s)\n",
 1103                         ip6_sprintf(&ia->ia_addr.sin6_addr),
 1104                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1105                 return;
 1106         }
 1107         bzero(dp, sizeof(*dp));
 1108         callout_init(&dp->dad_timer_ch);
 1109         TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list);
 1110 
 1111         nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
 1112             ip6_sprintf(&ia->ia_addr.sin6_addr)));
 1113 
 1114         /*
 1115          * Send NS packet for DAD, ip6_dad_count times.
 1116          * Note that we must delay the first transmission, if this is the
 1117          * first packet to be sent from the interface after interface
 1118          * (re)initialization.
 1119          */
 1120         dp->dad_ifa = ifa;
 1121         IFAREF(ifa);    /* just for safety */
 1122         dp->dad_count = ip6_dad_count;
 1123         dp->dad_ns_icount = dp->dad_na_icount = 0;
 1124         dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
 1125         if (tick == NULL) {
 1126                 nd6_dad_ns_output(dp, ifa);
 1127                 nd6_dad_starttimer(dp,
 1128                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1129         } else {
 1130                 int ntick;
 1131 
 1132                 if (*tick == 0)
 1133                         ntick = arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz);
 1134                 else
 1135                         ntick = *tick + arc4random() % (hz / 2);
 1136                 *tick = ntick;
 1137                 nd6_dad_starttimer(dp, ntick);
 1138         }
 1139 }
 1140 
 1141 /*
 1142  * terminate DAD unconditionally.  used for address removals.
 1143  */
 1144 void
 1145 nd6_dad_stop(ifa)
 1146         struct ifaddr *ifa;
 1147 {
 1148         struct dadq *dp;
 1149 
 1150         if (!dad_init)
 1151                 return;
 1152         dp = nd6_dad_find(ifa);
 1153         if (!dp) {
 1154                 /* DAD wasn't started yet */
 1155                 return;
 1156         }
 1157 
 1158         nd6_dad_stoptimer(dp);
 1159 
 1160         TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
 1161         free(dp, M_IP6NDP);
 1162         dp = NULL;
 1163         IFAFREE(ifa);
 1164 }
 1165 
 1166 static void
 1167 nd6_dad_timer(ifa)
 1168         struct ifaddr *ifa;
 1169 {
 1170         int s;
 1171         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1172         struct dadq *dp;
 1173 
 1174         s = splsoftnet();       /* XXX */
 1175 
 1176         /* Sanity check */
 1177         if (ia == NULL) {
 1178                 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
 1179                 goto done;
 1180         }
 1181         dp = nd6_dad_find(ifa);
 1182         if (dp == NULL) {
 1183                 log(LOG_ERR, "nd6_dad_timer: DAD structure not found\n");
 1184                 goto done;
 1185         }
 1186         if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
 1187                 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
 1188                         "%s(%s)\n",
 1189                         ip6_sprintf(&ia->ia_addr.sin6_addr),
 1190                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1191                 goto done;
 1192         }
 1193         if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
 1194                 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
 1195                         "%s(%s)\n",
 1196                         ip6_sprintf(&ia->ia_addr.sin6_addr),
 1197                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1198                 goto done;
 1199         }
 1200 
 1201         /* timeouted with IFF_{RUNNING,UP} check */
 1202         if (dp->dad_ns_tcount > dad_maxtry) {
 1203                 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
 1204                         if_name(ifa->ifa_ifp)));
 1205 
 1206                 TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
 1207                 free(dp, M_IP6NDP);
 1208                 dp = NULL;
 1209                 IFAFREE(ifa);
 1210                 goto done;
 1211         }
 1212 
 1213         /* Need more checks? */
 1214         if (dp->dad_ns_ocount < dp->dad_count) {
 1215                 /*
 1216                  * We have more NS to go.  Send NS packet for DAD.
 1217                  */
 1218                 nd6_dad_ns_output(dp, ifa);
 1219                 nd6_dad_starttimer(dp,
 1220                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1221         } else {
 1222                 /*
 1223                  * We have transmitted sufficient number of DAD packets.
 1224                  * See what we've got.
 1225                  */
 1226                 int duplicate;
 1227 
 1228                 duplicate = 0;
 1229 
 1230                 if (dp->dad_na_icount) {
 1231                         /*
 1232                          * the check is in nd6_dad_na_input(),
 1233                          * but just in case
 1234                          */
 1235                         duplicate++;
 1236                 }
 1237 
 1238                 if (dp->dad_ns_icount) {
 1239 #if 0 /* heuristics */
 1240                         /*
 1241                          * if
 1242                          * - we have sent many(?) DAD NS, and
 1243                          * - the number of NS we sent equals to the
 1244                          *   number of NS we've got, and
 1245                          * - we've got no NA
 1246                          * we may have a faulty network card/driver which
 1247                          * loops back multicasts to myself.
 1248                          */
 1249                         if (3 < dp->dad_count
 1250                          && dp->dad_ns_icount == dp->dad_count
 1251                          && dp->dad_na_icount == 0) {
 1252                                 log(LOG_INFO, "DAD questionable for %s(%s): "
 1253                                     "network card loops back multicast?\n",
 1254                                     ip6_sprintf(&ia->ia_addr.sin6_addr),
 1255                                     if_name(ifa->ifa_ifp));
 1256                                 /* XXX consider it a duplicate or not? */
 1257                                 /* duplicate++; */
 1258                         } else {
 1259                                 /* We've seen NS, means DAD has failed. */
 1260                                 duplicate++;
 1261                         }
 1262 #else
 1263                         /* We've seen NS, means DAD has failed. */
 1264                         duplicate++;
 1265 #endif
 1266                 }
 1267 
 1268                 if (duplicate) {
 1269                         /* (*dp) will be freed in nd6_dad_duplicated() */
 1270                         dp = NULL;
 1271                         nd6_dad_duplicated(ifa);
 1272                 } else {
 1273                         /*
 1274                          * We are done with DAD.  No NA came, no NS came.
 1275                          * duplicated address found.
 1276                          */
 1277                         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1278 
 1279                         nd6log((LOG_DEBUG,
 1280                             "%s: DAD complete for %s - no duplicates found\n",
 1281                             if_name(ifa->ifa_ifp),
 1282                             ip6_sprintf(&ia->ia_addr.sin6_addr)));
 1283 
 1284                         TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
 1285                         free(dp, M_IP6NDP);
 1286                         dp = NULL;
 1287                         IFAFREE(ifa);
 1288                 }
 1289         }
 1290 
 1291 done:
 1292         splx(s);
 1293 }
 1294 
 1295 void
 1296 nd6_dad_duplicated(ifa)
 1297         struct ifaddr *ifa;
 1298 {
 1299         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1300         struct dadq *dp;
 1301 
 1302         dp = nd6_dad_find(ifa);
 1303         if (dp == NULL) {
 1304                 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
 1305                 return;
 1306         }
 1307 
 1308         log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
 1309             "NS in/out=%d/%d, NA in=%d\n",
 1310             if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr),
 1311             dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
 1312 
 1313         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1314         ia->ia6_flags |= IN6_IFF_DUPLICATED;
 1315 
 1316         /* We are done with DAD, with duplicated address found. (failure) */
 1317         nd6_dad_stoptimer(dp);
 1318 
 1319         log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
 1320             if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr));
 1321         log(LOG_ERR, "%s: manual intervention required\n",
 1322             if_name(ifa->ifa_ifp));
 1323 
 1324         TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
 1325         free(dp, M_IP6NDP);
 1326         dp = NULL;
 1327         IFAFREE(ifa);
 1328 }
 1329 
 1330 static void
 1331 nd6_dad_ns_output(dp, ifa)
 1332         struct dadq *dp;
 1333         struct ifaddr *ifa;
 1334 {
 1335         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1336         struct ifnet *ifp = ifa->ifa_ifp;
 1337 
 1338         dp->dad_ns_tcount++;
 1339         if ((ifp->if_flags & IFF_UP) == 0) {
 1340 #if 0
 1341                 printf("%s: interface down?\n", if_name(ifp));
 1342 #endif
 1343                 return;
 1344         }
 1345         if ((ifp->if_flags & IFF_RUNNING) == 0) {
 1346 #if 0
 1347                 printf("%s: interface not running?\n", if_name(ifp));
 1348 #endif
 1349                 return;
 1350         }
 1351 
 1352         dp->dad_ns_ocount++;
 1353         nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
 1354 }
 1355 
 1356 static void
 1357 nd6_dad_ns_input(ifa)
 1358         struct ifaddr *ifa;
 1359 {
 1360         struct in6_ifaddr *ia;
 1361         const struct in6_addr *taddr6;
 1362         struct dadq *dp;
 1363         int duplicate;
 1364 
 1365         if (!ifa)
 1366                 panic("ifa == NULL in nd6_dad_ns_input");
 1367 
 1368         ia = (struct in6_ifaddr *)ifa;
 1369         taddr6 = &ia->ia_addr.sin6_addr;
 1370         duplicate = 0;
 1371         dp = nd6_dad_find(ifa);
 1372 
 1373         /* Quickhack - completely ignore DAD NS packets */
 1374         if (dad_ignore_ns) {
 1375                 nd6log((LOG_INFO,
 1376                     "nd6_dad_ns_input: ignoring DAD NS packet for "
 1377                     "address %s(%s)\n", ip6_sprintf(taddr6),
 1378                     if_name(ifa->ifa_ifp)));
 1379                 return;
 1380         }
 1381 
 1382         /*
 1383          * if I'm yet to start DAD, someone else started using this address
 1384          * first.  I have a duplicate and you win.
 1385          */
 1386         if (!dp || dp->dad_ns_ocount == 0)
 1387                 duplicate++;
 1388 
 1389         /* XXX more checks for loopback situation - see nd6_dad_timer too */
 1390 
 1391         if (duplicate) {
 1392                 dp = NULL;      /* will be freed in nd6_dad_duplicated() */
 1393                 nd6_dad_duplicated(ifa);
 1394         } else {
 1395                 /*
 1396                  * not sure if I got a duplicate.
 1397                  * increment ns count and see what happens.
 1398                  */
 1399                 if (dp)
 1400                         dp->dad_ns_icount++;
 1401         }
 1402 }
 1403 
 1404 static void
 1405 nd6_dad_na_input(ifa)
 1406         struct ifaddr *ifa;
 1407 {
 1408         struct dadq *dp;
 1409 
 1410         if (!ifa)
 1411                 panic("ifa == NULL in nd6_dad_na_input");
 1412 
 1413         dp = nd6_dad_find(ifa);
 1414         if (dp)
 1415                 dp->dad_na_icount++;
 1416 
 1417         /* remove the address. */
 1418         nd6_dad_duplicated(ifa);
 1419 }

Cache object: 2fb90eb0d53f38fb8971327f89e57a92


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