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/8.2/sys/netinet6/nd6_nbr.c 216118 2010-12-02 10:39:44Z 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 = NULL;
  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)
  251                         RTFREE_LOCKED(rt);
  252                 if (need_proxy) {
  253                         /*
  254                          * proxy NDP for single entry
  255                          */
  256                         ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
  257                                 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
  258                         if (ifa) {
  259                                 proxy = 1;
  260                                 proxydl = SDL(rt->rt_gateway);
  261                         }
  262                 }
  263         }
  264         if (ifa == NULL) {
  265                 /*
  266                  * We've got an NS packet, and we don't have that adddress
  267                  * assigned for us.  We MUST silently ignore it.
  268                  * See RFC2461 7.2.3.
  269                  */
  270                 goto freeit;
  271         }
  272         myaddr6 = *IFA_IN6(ifa);
  273         anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
  274         tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
  275         if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
  276                 goto freeit;
  277 
  278         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  279                 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
  280                     "(if %d, NS packet %d)\n",
  281                     ip6_sprintf(ip6bufs, &taddr6),
  282                     ifp->if_addrlen, lladdrlen - 2));
  283                 goto bad;
  284         }
  285 
  286         if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
  287                 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
  288                     ip6_sprintf(ip6bufs, &saddr6)));
  289                 goto freeit;
  290         }
  291 
  292         /*
  293          * We have neighbor solicitation packet, with target address equals to
  294          * one of my tentative address.
  295          *
  296          * src addr     how to process?
  297          * ---          ---
  298          * multicast    of course, invalid (rejected in ip6_input)
  299          * unicast      somebody is doing address resolution -> ignore
  300          * unspec       dup address detection
  301          *
  302          * The processing is defined in RFC 2462.
  303          */
  304         if (tentative) {
  305                 /*
  306                  * If source address is unspecified address, it is for
  307                  * duplicate address detection.
  308                  *
  309                  * If not, the packet is for addess resolution;
  310                  * silently ignore it.
  311                  */
  312                 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
  313                         nd6_dad_ns_input(ifa);
  314 
  315                 goto freeit;
  316         }
  317 
  318         /*
  319          * If the source address is unspecified address, entries must not
  320          * be created or updated.
  321          * It looks that sender is performing DAD.  Output NA toward
  322          * all-node multicast address, to tell the sender that I'm using
  323          * the address.
  324          * S bit ("solicited") must be zero.
  325          */
  326         if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
  327                 struct in6_addr in6_all;
  328 
  329                 in6_all = in6addr_linklocal_allnodes;
  330                 if (in6_setscope(&in6_all, ifp, NULL) != 0)
  331                         goto bad;
  332                 nd6_na_output(ifp, &in6_all, &taddr6,
  333                     ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  334                     (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0),
  335                     tlladdr, (struct sockaddr *)proxydl);
  336                 goto freeit;
  337         }
  338 
  339         nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
  340             ND_NEIGHBOR_SOLICIT, 0);
  341 
  342         nd6_na_output(ifp, &saddr6, &taddr6,
  343             ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
  344             (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
  345             tlladdr, (struct sockaddr *)proxydl);
  346  freeit:
  347         if (ifa != NULL)
  348                 ifa_free(ifa);
  349         m_freem(m);
  350         return;
  351 
  352  bad:
  353         nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
  354                 ip6_sprintf(ip6bufs, &saddr6)));
  355         nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
  356                 ip6_sprintf(ip6bufs, &daddr6)));
  357         nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
  358                 ip6_sprintf(ip6bufs, &taddr6)));
  359         ICMP6STAT_INC(icp6s_badns);
  360         if (ifa != NULL)
  361                 ifa_free(ifa);
  362         m_freem(m);
  363 }
  364 
  365 /*
  366  * Output a Neighbor Solicitation Message. Caller specifies:
  367  *      - ICMP6 header source IP6 address
  368  *      - ND6 header target IP6 address
  369  *      - ND6 header source datalink address
  370  *
  371  * Based on RFC 2461
  372  * Based on RFC 2462 (duplicate address detection)
  373  *
  374  *   ln - for source address determination
  375  *  dad - duplicate address detection
  376  */
  377 void
  378 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 
  379     const struct in6_addr *taddr6, struct llentry *ln, int dad)
  380 {
  381         struct mbuf *m;
  382         struct ip6_hdr *ip6;
  383         struct nd_neighbor_solicit *nd_ns;
  384         struct ip6_moptions im6o;
  385         int icmp6len;
  386         int maxlen;
  387         caddr_t mac;
  388         struct route_in6 ro;
  389 
  390         if (IN6_IS_ADDR_MULTICAST(taddr6))
  391                 return;
  392 
  393         /* estimate the size of message */
  394         maxlen = sizeof(*ip6) + sizeof(*nd_ns);
  395         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  396         if (max_linkhdr + maxlen >= MCLBYTES) {
  397 #ifdef DIAGNOSTIC
  398                 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
  399                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  400 #endif
  401                 return;
  402         }
  403 
  404         MGETHDR(m, M_DONTWAIT, MT_DATA);
  405         if (m && max_linkhdr + maxlen >= MHLEN) {
  406                 MCLGET(m, M_DONTWAIT);
  407                 if ((m->m_flags & M_EXT) == 0) {
  408                         m_free(m);
  409                         m = NULL;
  410                 }
  411         }
  412         if (m == NULL)
  413                 return;
  414         m->m_pkthdr.rcvif = NULL;
  415 
  416         bzero(&ro, sizeof(ro));
  417 
  418         if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
  419                 m->m_flags |= M_MCAST;
  420                 im6o.im6o_multicast_ifp = ifp;
  421                 im6o.im6o_multicast_hlim = 255;
  422                 im6o.im6o_multicast_loop = 0;
  423         }
  424 
  425         icmp6len = sizeof(*nd_ns);
  426         m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
  427         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  428 
  429         /* fill neighbor solicitation packet */
  430         ip6 = mtod(m, struct ip6_hdr *);
  431         ip6->ip6_flow = 0;
  432         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  433         ip6->ip6_vfc |= IPV6_VERSION;
  434         /* ip6->ip6_plen will be set later */
  435         ip6->ip6_nxt = IPPROTO_ICMPV6;
  436         ip6->ip6_hlim = 255;
  437         if (daddr6)
  438                 ip6->ip6_dst = *daddr6;
  439         else {
  440                 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  441                 ip6->ip6_dst.s6_addr16[1] = 0;
  442                 ip6->ip6_dst.s6_addr32[1] = 0;
  443                 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
  444                 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
  445                 ip6->ip6_dst.s6_addr8[12] = 0xff;
  446                 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
  447                         goto bad;
  448         }
  449         if (!dad) {
  450                 struct ifaddr *ifa;
  451 
  452                 /*
  453                  * RFC2461 7.2.2:
  454                  * "If the source address of the packet prompting the
  455                  * solicitation is the same as one of the addresses assigned
  456                  * to the outgoing interface, that address SHOULD be placed
  457                  * in the IP Source Address of the outgoing solicitation.
  458                  * Otherwise, any one of the addresses assigned to the
  459                  * interface should be used."
  460                  *
  461                  * We use the source address for the prompting packet
  462                  * (saddr6), if:
  463                  * - saddr6 is given from the caller (by giving "ln"), and
  464                  * - saddr6 belongs to the outgoing interface.
  465                  * Otherwise, we perform the source address selection as usual.
  466                  */
  467                 struct in6_addr *hsrc;
  468 
  469                 hsrc = NULL;
  470                 if (ln != NULL) {
  471                         LLE_RLOCK(ln);
  472                         if (ln->la_hold != NULL) {
  473                                 struct ip6_hdr *hip6;           /* hold ip6 */
  474 
  475                                 /*
  476                                  * assuming every packet in la_hold has the same IP
  477                                  * header
  478                                  */
  479                                 hip6 = mtod(ln->la_hold, struct ip6_hdr *);
  480                                 /* XXX pullup? */
  481                                 if (sizeof(*hip6) < ln->la_hold->m_len) {
  482                                         ip6->ip6_src = hip6->ip6_src;
  483                                         hsrc = &hip6->ip6_src;
  484                                 }
  485                         }
  486                         LLE_RUNLOCK(ln);
  487                 }
  488                 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
  489                     hsrc)) != NULL) {
  490                         /* ip6_src set already. */
  491                         ifa_free(ifa);
  492                 } else {
  493                         int error;
  494                         struct sockaddr_in6 dst_sa;
  495                         struct in6_addr src_in;
  496 
  497                         bzero(&dst_sa, sizeof(dst_sa));
  498                         dst_sa.sin6_family = AF_INET6;
  499                         dst_sa.sin6_len = sizeof(dst_sa);
  500                         dst_sa.sin6_addr = ip6->ip6_dst;
  501 
  502                         error = in6_selectsrc(&dst_sa, NULL,
  503                             NULL, &ro, NULL, NULL, &src_in);
  504                         if (error) {
  505                                 char ip6buf[INET6_ADDRSTRLEN];
  506                                 nd6log((LOG_DEBUG,
  507                                     "nd6_ns_output: source can't be "
  508                                     "determined: dst=%s, error=%d\n",
  509                                     ip6_sprintf(ip6buf, &dst_sa.sin6_addr),
  510                                     error));
  511                                 goto bad;
  512                         }
  513                         ip6->ip6_src = src_in;
  514                 }
  515         } else {
  516                 /*
  517                  * Source address for DAD packet must always be IPv6
  518                  * unspecified address. (0::0)
  519                  * We actually don't have to 0-clear the address (we did it
  520                  * above), but we do so here explicitly to make the intention
  521                  * clearer.
  522                  */
  523                 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
  524         }
  525         nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
  526         nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
  527         nd_ns->nd_ns_code = 0;
  528         nd_ns->nd_ns_reserved = 0;
  529         nd_ns->nd_ns_target = *taddr6;
  530         in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
  531 
  532         /*
  533          * Add source link-layer address option.
  534          *
  535          *                              spec            implementation
  536          *                              ---             ---
  537          * DAD packet                   MUST NOT        do not add the option
  538          * there's no link layer address:
  539          *                              impossible      do not add the option
  540          * there's link layer address:
  541          *      Multicast NS            MUST add one    add the option
  542          *      Unicast NS              SHOULD add one  add the option
  543          */
  544         if (!dad && (mac = nd6_ifptomac(ifp))) {
  545                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
  546                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
  547                 /* 8 byte alignments... */
  548                 optlen = (optlen + 7) & ~7;
  549 
  550                 m->m_pkthdr.len += optlen;
  551                 m->m_len += optlen;
  552                 icmp6len += optlen;
  553                 bzero((caddr_t)nd_opt, optlen);
  554                 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
  555                 nd_opt->nd_opt_len = optlen >> 3;
  556                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
  557         }
  558 
  559         ip6->ip6_plen = htons((u_short)icmp6len);
  560         nd_ns->nd_ns_cksum = 0;
  561         nd_ns->nd_ns_cksum =
  562             in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
  563 
  564         ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
  565         icmp6_ifstat_inc(ifp, ifs6_out_msg);
  566         icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
  567         ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
  568 
  569         if (ro.ro_rt) {         /* we don't cache this route. */
  570                 RTFREE(ro.ro_rt);
  571         }
  572         return;
  573 
  574   bad:
  575         if (ro.ro_rt) {
  576                 RTFREE(ro.ro_rt);
  577         }
  578         m_freem(m);
  579         return;
  580 }
  581 
  582 /*
  583  * Neighbor advertisement input handling.
  584  *
  585  * Based on RFC 2461
  586  * Based on RFC 2462 (duplicate address detection)
  587  *
  588  * the following items are not implemented yet:
  589  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  590  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  591  */
  592 void
  593 nd6_na_input(struct mbuf *m, int off, int icmp6len)
  594 {
  595         struct ifnet *ifp = m->m_pkthdr.rcvif;
  596         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
  597         struct nd_neighbor_advert *nd_na;
  598         struct in6_addr daddr6 = ip6->ip6_dst;
  599         struct in6_addr taddr6;
  600         int flags;
  601         int is_router;
  602         int is_solicited;
  603         int is_override;
  604         char *lladdr = NULL;
  605         int lladdrlen = 0;
  606         int checklink = 0;
  607         struct ifaddr *ifa;
  608         struct llentry *ln = NULL;
  609         union nd_opts ndopts;
  610         struct mbuf *chain = NULL;
  611         struct sockaddr_in6 sin6;
  612         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  613 
  614         if (ip6->ip6_hlim != 255) {
  615                 nd6log((LOG_ERR,
  616                     "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
  617                     ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  618                     ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
  619                 goto bad;
  620         }
  621 
  622 #ifndef PULLDOWN_TEST
  623         IP6_EXTHDR_CHECK(m, off, icmp6len,);
  624         nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
  625 #else
  626         IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
  627         if (nd_na == NULL) {
  628                 ICMP6STAT_INC(icp6s_tooshort);
  629                 return;
  630         }
  631 #endif
  632 
  633         flags = nd_na->nd_na_flags_reserved;
  634         is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
  635         is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
  636         is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
  637 
  638         taddr6 = nd_na->nd_na_target;
  639         if (in6_setscope(&taddr6, ifp, NULL))
  640                 goto bad;       /* XXX: impossible */
  641 
  642         if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
  643                 nd6log((LOG_ERR,
  644                     "nd6_na_input: invalid target address %s\n",
  645                     ip6_sprintf(ip6bufs, &taddr6)));
  646                 goto bad;
  647         }
  648         if (IN6_IS_ADDR_MULTICAST(&daddr6))
  649                 if (is_solicited) {
  650                         nd6log((LOG_ERR,
  651                             "nd6_na_input: a solicited adv is multicasted\n"));
  652                         goto bad;
  653                 }
  654 
  655         icmp6len -= sizeof(*nd_na);
  656         nd6_option_init(nd_na + 1, icmp6len, &ndopts);
  657         if (nd6_options(&ndopts) < 0) {
  658                 nd6log((LOG_INFO,
  659                     "nd6_na_input: invalid ND option, ignored\n"));
  660                 /* nd6_options have incremented stats */
  661                 goto freeit;
  662         }
  663 
  664         if (ndopts.nd_opts_tgt_lladdr) {
  665                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
  666                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
  667         }
  668 
  669         ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
  670 
  671         /*
  672          * Target address matches one of my interface address.
  673          *
  674          * If my address is tentative, this means that there's somebody
  675          * already using the same address as mine.  This indicates DAD failure.
  676          * This is defined in RFC 2462.
  677          *
  678          * Otherwise, process as defined in RFC 2461.
  679          */
  680         if (ifa
  681          && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
  682                 ifa_free(ifa);
  683                 nd6_dad_na_input(ifa);
  684                 goto freeit;
  685         }
  686 
  687         /* Just for safety, maybe unnecessary. */
  688         if (ifa) {
  689                 ifa_free(ifa);
  690                 log(LOG_ERR,
  691                     "nd6_na_input: duplicate IP6 address %s\n",
  692                     ip6_sprintf(ip6bufs, &taddr6));
  693                 goto freeit;
  694         }
  695 
  696         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
  697                 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
  698                     "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
  699                     ifp->if_addrlen, lladdrlen - 2));
  700                 goto bad;
  701         }
  702 
  703         /*
  704          * If no neighbor cache entry is found, NA SHOULD silently be
  705          * discarded.
  706          */
  707         IF_AFDATA_LOCK(ifp);
  708         ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
  709         IF_AFDATA_UNLOCK(ifp);
  710         if (ln == NULL) {
  711                 goto freeit;
  712         }
  713 
  714         if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
  715                 /*
  716                  * If the link-layer has address, and no lladdr option came,
  717                  * discard the packet.
  718                  */
  719                 if (ifp->if_addrlen && lladdr == NULL) {
  720                         goto freeit;
  721                 }
  722 
  723                 /*
  724                  * Record link-layer address, and update the state.
  725                  */
  726                 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
  727                 ln->la_flags |= LLE_VALID;
  728                 if (is_solicited) {
  729                         ln->ln_state = ND6_LLINFO_REACHABLE;
  730                         ln->ln_byhint = 0;
  731                         if (!ND6_LLINFO_PERMANENT(ln)) {
  732                                 nd6_llinfo_settimer_locked(ln,
  733                                     (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz);
  734                         }
  735                 } else {
  736                         ln->ln_state = ND6_LLINFO_STALE;
  737                         nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
  738                 }
  739                 if ((ln->ln_router = is_router) != 0) {
  740                         /*
  741                          * This means a router's state has changed from
  742                          * non-reachable to probably reachable, and might
  743                          * affect the status of associated prefixes..
  744                          */
  745                         checklink = 1;
  746                 }
  747         } else {
  748                 int llchange;
  749 
  750                 /*
  751                  * Check if the link-layer address has changed or not.
  752                  */
  753                 if (lladdr == NULL)
  754                         llchange = 0;
  755                 else {
  756                         if (ln->la_flags & LLE_VALID) {
  757                                 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen))
  758                                         llchange = 1;
  759                                 else
  760                                         llchange = 0;
  761                         } else
  762                                 llchange = 1;
  763                 }
  764 
  765                 /*
  766                  * This is VERY complex.  Look at it with care.
  767                  *
  768                  * override solicit lladdr llchange     action
  769                  *                                      (L: record lladdr)
  770                  *
  771                  *      0       0       n       --      (2c)
  772                  *      0       0       y       n       (2b) L
  773                  *      0       0       y       y       (1)    REACHABLE->STALE
  774                  *      0       1       n       --      (2c)   *->REACHABLE
  775                  *      0       1       y       n       (2b) L *->REACHABLE
  776                  *      0       1       y       y       (1)    REACHABLE->STALE
  777                  *      1       0       n       --      (2a)
  778                  *      1       0       y       n       (2a) L
  779                  *      1       0       y       y       (2a) L *->STALE
  780                  *      1       1       n       --      (2a)   *->REACHABLE
  781                  *      1       1       y       n       (2a) L *->REACHABLE
  782                  *      1       1       y       y       (2a) L *->REACHABLE
  783                  */
  784                 if (!is_override && (lladdr != NULL && llchange)) {  /* (1) */
  785                         /*
  786                          * If state is REACHABLE, make it STALE.
  787                          * no other updates should be done.
  788                          */
  789                         if (ln->ln_state == ND6_LLINFO_REACHABLE) {
  790                                 ln->ln_state = ND6_LLINFO_STALE;
  791                                 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
  792                         }
  793                         goto freeit;
  794                 } else if (is_override                             /* (2a) */
  795                         || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
  796                         || lladdr == NULL) {                       /* (2c) */
  797                         /*
  798                          * Update link-local address, if any.
  799                          */
  800                         if (lladdr != NULL) {
  801                                 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
  802                                 ln->la_flags |= LLE_VALID;
  803                         }
  804 
  805                         /*
  806                          * If solicited, make the state REACHABLE.
  807                          * If not solicited and the link-layer address was
  808                          * changed, make it STALE.
  809                          */
  810                         if (is_solicited) {
  811                                 ln->ln_state = ND6_LLINFO_REACHABLE;
  812                                 ln->ln_byhint = 0;
  813                                 if (!ND6_LLINFO_PERMANENT(ln)) {
  814                                         nd6_llinfo_settimer_locked(ln,
  815                                             (long)ND_IFINFO(ifp)->reachable * hz);
  816                                 }
  817                         } else {
  818                                 if (lladdr != NULL && llchange) {
  819                                         ln->ln_state = ND6_LLINFO_STALE;
  820                                         nd6_llinfo_settimer_locked(ln,
  821                                             (long)V_nd6_gctimer * hz);
  822                                 }
  823                         }
  824                 }
  825 
  826                 if (ln->ln_router && !is_router) {
  827                         /*
  828                          * The peer dropped the router flag.
  829                          * Remove the sender from the Default Router List and
  830                          * update the Destination Cache entries.
  831                          */
  832                         struct nd_defrouter *dr;
  833                         struct in6_addr *in6;
  834 
  835                         in6 = &L3_ADDR_SIN6(ln)->sin6_addr;
  836 
  837                         /*
  838                          * Lock to protect the default router list.
  839                          * XXX: this might be unnecessary, since this function
  840                          * is only called under the network software interrupt
  841                          * context.  However, we keep it just for safety.
  842                          */
  843                         dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp);
  844                         if (dr)
  845                                 defrtrlist_del(dr);
  846                         else if (!V_ip6_forwarding) {
  847                                 /*
  848                                  * Even if the neighbor is not in the default
  849                                  * router list, the neighbor may be used
  850                                  * as a next hop for some destinations
  851                                  * (e.g. redirect case). So we must
  852                                  * call rt6_flush explicitly.
  853                                  */
  854                                 rt6_flush(&ip6->ip6_src, ifp);
  855                         }
  856                 }
  857                 ln->ln_router = is_router;
  858         }
  859         /* XXX - QL
  860          *  Does this matter?
  861          *  rt->rt_flags &= ~RTF_REJECT;
  862          */
  863         ln->la_asked = 0;
  864         if (ln->la_hold) {
  865                 struct mbuf *m_hold, *m_hold_next;
  866 
  867                 /*
  868                  * reset the la_hold in advance, to explicitly
  869                  * prevent a la_hold lookup in nd6_output()
  870                  * (wouldn't happen, though...)
  871                  */
  872                 for (m_hold = ln->la_hold, ln->la_hold = NULL;
  873                     m_hold; m_hold = m_hold_next) {
  874                         m_hold_next = m_hold->m_nextpkt;
  875                         m_hold->m_nextpkt = NULL;
  876                         /*
  877                          * we assume ifp is not a loopback here, so just set
  878                          * the 2nd argument as the 1st one.
  879                          */
  880                         nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
  881                 }
  882         }
  883  freeit:
  884         if (ln != NULL) {
  885                 if (chain)
  886                         memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
  887                 LLE_WUNLOCK(ln);
  888 
  889                 if (chain)
  890                         nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
  891         }
  892         if (checklink)
  893                 pfxlist_onlink_check();
  894 
  895         m_freem(m);
  896         return;
  897 
  898  bad:
  899         if (ln != NULL)
  900                 LLE_WUNLOCK(ln);
  901 
  902         ICMP6STAT_INC(icp6s_badna);
  903         m_freem(m);
  904 }
  905 
  906 /*
  907  * Neighbor advertisement output handling.
  908  *
  909  * Based on RFC 2461
  910  *
  911  * the following items are not implemented yet:
  912  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
  913  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
  914  *
  915  * tlladdr - 1 if include target link-layer address
  916  * sdl0 - sockaddr_dl (= proxy NA) or NULL
  917  */
  918 void
  919 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
  920     const struct in6_addr *taddr6, u_long flags, int tlladdr,
  921     struct sockaddr *sdl0)
  922 {
  923         struct mbuf *m;
  924         struct ip6_hdr *ip6;
  925         struct nd_neighbor_advert *nd_na;
  926         struct ip6_moptions im6o;
  927         struct in6_addr src, daddr6;
  928         struct sockaddr_in6 dst_sa;
  929         int icmp6len, maxlen, error;
  930         caddr_t mac = NULL;
  931         struct route_in6 ro;
  932 
  933         bzero(&ro, sizeof(ro));
  934 
  935         daddr6 = *daddr6_0;     /* make a local copy for modification */
  936 
  937         /* estimate the size of message */
  938         maxlen = sizeof(*ip6) + sizeof(*nd_na);
  939         maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
  940         if (max_linkhdr + maxlen >= MCLBYTES) {
  941 #ifdef DIAGNOSTIC
  942                 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
  943                     "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
  944 #endif
  945                 return;
  946         }
  947 
  948         MGETHDR(m, M_DONTWAIT, MT_DATA);
  949         if (m && max_linkhdr + maxlen >= MHLEN) {
  950                 MCLGET(m, M_DONTWAIT);
  951                 if ((m->m_flags & M_EXT) == 0) {
  952                         m_free(m);
  953                         m = NULL;
  954                 }
  955         }
  956         if (m == NULL)
  957                 return;
  958         m->m_pkthdr.rcvif = NULL;
  959 
  960         if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
  961                 m->m_flags |= M_MCAST;
  962                 im6o.im6o_multicast_ifp = ifp;
  963                 im6o.im6o_multicast_hlim = 255;
  964                 im6o.im6o_multicast_loop = 0;
  965         }
  966 
  967         icmp6len = sizeof(*nd_na);
  968         m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
  969         m->m_data += max_linkhdr;       /* or MH_ALIGN() equivalent? */
  970 
  971         /* fill neighbor advertisement packet */
  972         ip6 = mtod(m, struct ip6_hdr *);
  973         ip6->ip6_flow = 0;
  974         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
  975         ip6->ip6_vfc |= IPV6_VERSION;
  976         ip6->ip6_nxt = IPPROTO_ICMPV6;
  977         ip6->ip6_hlim = 255;
  978         if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
  979                 /* reply to DAD */
  980                 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
  981                 daddr6.s6_addr16[1] = 0;
  982                 daddr6.s6_addr32[1] = 0;
  983                 daddr6.s6_addr32[2] = 0;
  984                 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
  985                 if (in6_setscope(&daddr6, ifp, NULL))
  986                         goto bad;
  987 
  988                 flags &= ~ND_NA_FLAG_SOLICITED;
  989         }
  990         ip6->ip6_dst = daddr6;
  991         bzero(&dst_sa, sizeof(struct sockaddr_in6));
  992         dst_sa.sin6_family = AF_INET6;
  993         dst_sa.sin6_len = sizeof(struct sockaddr_in6);
  994         dst_sa.sin6_addr = daddr6;
  995 
  996         /*
  997          * Select a source whose scope is the same as that of the dest.
  998          */
  999         bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
 1000         error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, NULL, &src);
 1001         if (error) {
 1002                 char ip6buf[INET6_ADDRSTRLEN];
 1003                 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
 1004                     "determined: dst=%s, error=%d\n",
 1005                     ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error));
 1006                 goto bad;
 1007         }
 1008         ip6->ip6_src = src;
 1009         nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
 1010         nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
 1011         nd_na->nd_na_code = 0;
 1012         nd_na->nd_na_target = *taddr6;
 1013         in6_clearscope(&nd_na->nd_na_target); /* XXX */
 1014 
 1015         /*
 1016          * "tlladdr" indicates NS's condition for adding tlladdr or not.
 1017          * see nd6_ns_input() for details.
 1018          * Basically, if NS packet is sent to unicast/anycast addr,
 1019          * target lladdr option SHOULD NOT be included.
 1020          */
 1021         if (tlladdr) {
 1022                 /*
 1023                  * sdl0 != NULL indicates proxy NA.  If we do proxy, use
 1024                  * lladdr in sdl0.  If we are not proxying (sending NA for
 1025                  * my address) use lladdr configured for the interface.
 1026                  */
 1027                 if (sdl0 == NULL) {
 1028                         if (ifp->if_carp)
 1029                                 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
 1030                         if (mac == NULL)
 1031                                 mac = nd6_ifptomac(ifp);
 1032                 } else if (sdl0->sa_family == AF_LINK) {
 1033                         struct sockaddr_dl *sdl;
 1034                         sdl = (struct sockaddr_dl *)sdl0;
 1035                         if (sdl->sdl_alen == ifp->if_addrlen)
 1036                                 mac = LLADDR(sdl);
 1037                 }
 1038         }
 1039         if (tlladdr && mac) {
 1040                 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
 1041                 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
 1042 
 1043                 /* roundup to 8 bytes alignment! */
 1044                 optlen = (optlen + 7) & ~7;
 1045 
 1046                 m->m_pkthdr.len += optlen;
 1047                 m->m_len += optlen;
 1048                 icmp6len += optlen;
 1049                 bzero((caddr_t)nd_opt, optlen);
 1050                 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
 1051                 nd_opt->nd_opt_len = optlen >> 3;
 1052                 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
 1053         } else
 1054                 flags &= ~ND_NA_FLAG_OVERRIDE;
 1055 
 1056         ip6->ip6_plen = htons((u_short)icmp6len);
 1057         nd_na->nd_na_flags_reserved = flags;
 1058         nd_na->nd_na_cksum = 0;
 1059         nd_na->nd_na_cksum =
 1060             in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
 1061 
 1062         ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL);
 1063         icmp6_ifstat_inc(ifp, ifs6_out_msg);
 1064         icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
 1065         ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
 1066 
 1067         if (ro.ro_rt) {         /* we don't cache this route. */
 1068                 RTFREE(ro.ro_rt);
 1069         }
 1070         return;
 1071 
 1072   bad:
 1073         if (ro.ro_rt) {
 1074                 RTFREE(ro.ro_rt);
 1075         }
 1076         m_freem(m);
 1077         return;
 1078 }
 1079 
 1080 caddr_t
 1081 nd6_ifptomac(struct ifnet *ifp)
 1082 {
 1083         switch (ifp->if_type) {
 1084         case IFT_ARCNET:
 1085         case IFT_ETHER:
 1086         case IFT_FDDI:
 1087         case IFT_IEEE1394:
 1088 #ifdef IFT_L2VLAN
 1089         case IFT_L2VLAN:
 1090 #endif
 1091 #ifdef IFT_IEEE80211
 1092         case IFT_IEEE80211:
 1093 #endif
 1094 #ifdef IFT_CARP
 1095         case IFT_CARP:
 1096 #endif
 1097         case IFT_BRIDGE:
 1098         case IFT_ISO88025:
 1099                 return IF_LLADDR(ifp);
 1100         default:
 1101                 return NULL;
 1102         }
 1103 }
 1104 
 1105 struct dadq {
 1106         TAILQ_ENTRY(dadq) dad_list;
 1107         struct ifaddr *dad_ifa;
 1108         int dad_count;          /* max NS to send */
 1109         int dad_ns_tcount;      /* # of trials to send NS */
 1110         int dad_ns_ocount;      /* NS sent so far */
 1111         int dad_ns_icount;
 1112         int dad_na_icount;
 1113         struct callout dad_timer_ch;
 1114         struct vnet *dad_vnet;
 1115 };
 1116 
 1117 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
 1118 VNET_DEFINE(int, dad_init) = 0;
 1119 #define V_dadq                          VNET(dadq)
 1120 #define V_dad_init                      VNET(dad_init)
 1121 
 1122 static struct dadq *
 1123 nd6_dad_find(struct ifaddr *ifa)
 1124 {
 1125         struct dadq *dp;
 1126 
 1127         for (dp = V_dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
 1128                 if (dp->dad_ifa == ifa)
 1129                         return dp;
 1130         }
 1131         return NULL;
 1132 }
 1133 
 1134 static void
 1135 nd6_dad_starttimer(struct dadq *dp, int ticks)
 1136 {
 1137 
 1138         callout_reset(&dp->dad_timer_ch, ticks,
 1139             (void (*)(void *))nd6_dad_timer, (void *)dp);
 1140 }
 1141 
 1142 static void
 1143 nd6_dad_stoptimer(struct dadq *dp)
 1144 {
 1145 
 1146         callout_stop(&dp->dad_timer_ch);
 1147 }
 1148 
 1149 /*
 1150  * Start Duplicate Address Detection (DAD) for specified interface address.
 1151  */
 1152 void
 1153 nd6_dad_start(struct ifaddr *ifa, int delay)
 1154 {
 1155         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1156         struct dadq *dp;
 1157         char ip6buf[INET6_ADDRSTRLEN];
 1158 
 1159         if (!V_dad_init) {
 1160                 TAILQ_INIT(&V_dadq);
 1161                 V_dad_init++;
 1162         }
 1163 
 1164         /*
 1165          * If we don't need DAD, don't do it.
 1166          * There are several cases:
 1167          * - DAD is disabled (ip6_dad_count == 0)
 1168          * - the interface address is anycast
 1169          */
 1170         if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
 1171                 log(LOG_DEBUG,
 1172                         "nd6_dad_start: called with non-tentative address "
 1173                         "%s(%s)\n",
 1174                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1175                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1176                 return;
 1177         }
 1178         if (ia->ia6_flags & IN6_IFF_ANYCAST) {
 1179                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1180                 return;
 1181         }
 1182         if (!V_ip6_dad_count) {
 1183                 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1184                 return;
 1185         }
 1186         if (ifa->ifa_ifp == NULL)
 1187                 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
 1188         if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
 1189                 return;
 1190         }
 1191         if (nd6_dad_find(ifa) != NULL) {
 1192                 /* DAD already in progress */
 1193                 return;
 1194         }
 1195 
 1196         dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
 1197         if (dp == NULL) {
 1198                 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
 1199                         "%s(%s)\n",
 1200                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1201                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1202                 return;
 1203         }
 1204         bzero(dp, sizeof(*dp));
 1205         callout_init(&dp->dad_timer_ch, 0);
 1206 #ifdef VIMAGE
 1207         dp->dad_vnet = curvnet;
 1208 #endif
 1209         TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list);
 1210 
 1211         nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
 1212             ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
 1213 
 1214         /*
 1215          * Send NS packet for DAD, ip6_dad_count times.
 1216          * Note that we must delay the first transmission, if this is the
 1217          * first packet to be sent from the interface after interface
 1218          * (re)initialization.
 1219          */
 1220         dp->dad_ifa = ifa;
 1221         ifa_ref(ifa);   /* just for safety */
 1222         dp->dad_count = V_ip6_dad_count;
 1223         dp->dad_ns_icount = dp->dad_na_icount = 0;
 1224         dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
 1225         if (delay == 0) {
 1226                 nd6_dad_ns_output(dp, ifa);
 1227                 nd6_dad_starttimer(dp,
 1228                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1229         } else {
 1230                 nd6_dad_starttimer(dp, delay);
 1231         }
 1232 }
 1233 
 1234 /*
 1235  * terminate DAD unconditionally.  used for address removals.
 1236  */
 1237 void
 1238 nd6_dad_stop(struct ifaddr *ifa)
 1239 {
 1240         struct dadq *dp;
 1241 
 1242         if (!V_dad_init)
 1243                 return;
 1244         dp = nd6_dad_find(ifa);
 1245         if (!dp) {
 1246                 /* DAD wasn't started yet */
 1247                 return;
 1248         }
 1249 
 1250         nd6_dad_stoptimer(dp);
 1251 
 1252         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1253         free(dp, M_IP6NDP);
 1254         dp = NULL;
 1255         ifa_free(ifa);
 1256 }
 1257 
 1258 static void
 1259 nd6_dad_timer(struct dadq *dp)
 1260 {
 1261         CURVNET_SET(dp->dad_vnet);
 1262         int s;
 1263         struct ifaddr *ifa = dp->dad_ifa;
 1264         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1265         char ip6buf[INET6_ADDRSTRLEN];
 1266 
 1267         s = splnet();           /* XXX */
 1268 
 1269         /* Sanity check */
 1270         if (ia == NULL) {
 1271                 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
 1272                 goto done;
 1273         }
 1274         if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
 1275                 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
 1276                         "%s(%s)\n",
 1277                         ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1278                         ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
 1279                 goto done;
 1280         }
 1281         if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
 1282                 log(LOG_ERR, "nd6_dad_timer: called with non-tentative 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 
 1289         /* timeouted with IFF_{RUNNING,UP} check */
 1290         if (dp->dad_ns_tcount > V_dad_maxtry) {
 1291                 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
 1292                     if_name(ifa->ifa_ifp)));
 1293 
 1294                 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1295                 free(dp, M_IP6NDP);
 1296                 dp = NULL;
 1297                 ifa_free(ifa);
 1298                 goto done;
 1299         }
 1300 
 1301         /* Need more checks? */
 1302         if (dp->dad_ns_ocount < dp->dad_count) {
 1303                 /*
 1304                  * We have more NS to go.  Send NS packet for DAD.
 1305                  */
 1306                 nd6_dad_ns_output(dp, ifa);
 1307                 nd6_dad_starttimer(dp,
 1308                     (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
 1309         } else {
 1310                 /*
 1311                  * We have transmitted sufficient number of DAD packets.
 1312                  * See what we've got.
 1313                  */
 1314                 int duplicate;
 1315 
 1316                 duplicate = 0;
 1317 
 1318                 if (dp->dad_na_icount) {
 1319                         /*
 1320                          * the check is in nd6_dad_na_input(),
 1321                          * but just in case
 1322                          */
 1323                         duplicate++;
 1324                 }
 1325 
 1326                 if (dp->dad_ns_icount) {
 1327                         /* We've seen NS, means DAD has failed. */
 1328                         duplicate++;
 1329                 }
 1330 
 1331                 if (duplicate) {
 1332                         /* (*dp) will be freed in nd6_dad_duplicated() */
 1333                         dp = NULL;
 1334                         nd6_dad_duplicated(ifa);
 1335                 } else {
 1336                         /*
 1337                          * We are done with DAD.  No NA came, no NS came.
 1338                          * No duplicate address found.
 1339                          */
 1340                         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1341 
 1342                         nd6log((LOG_DEBUG,
 1343                             "%s: DAD complete for %s - no duplicates found\n",
 1344                             if_name(ifa->ifa_ifp),
 1345                             ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
 1346 
 1347                         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1348                         free(dp, M_IP6NDP);
 1349                         dp = NULL;
 1350                         ifa_free(ifa);
 1351                 }
 1352         }
 1353 
 1354 done:
 1355         splx(s);
 1356         CURVNET_RESTORE();
 1357 }
 1358 
 1359 void
 1360 nd6_dad_duplicated(struct ifaddr *ifa)
 1361 {
 1362         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1363         struct ifnet *ifp;
 1364         struct dadq *dp;
 1365         char ip6buf[INET6_ADDRSTRLEN];
 1366 
 1367         dp = nd6_dad_find(ifa);
 1368         if (dp == NULL) {
 1369                 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
 1370                 return;
 1371         }
 1372 
 1373         log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
 1374             "NS in/out=%d/%d, NA in=%d\n",
 1375             if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
 1376             dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
 1377 
 1378         ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
 1379         ia->ia6_flags |= IN6_IFF_DUPLICATED;
 1380 
 1381         /* We are done with DAD, with duplicate address found. (failure) */
 1382         nd6_dad_stoptimer(dp);
 1383 
 1384         ifp = ifa->ifa_ifp;
 1385         log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
 1386             if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
 1387         log(LOG_ERR, "%s: manual intervention required\n",
 1388             if_name(ifp));
 1389 
 1390         /*
 1391          * If the address is a link-local address formed from an interface
 1392          * identifier based on the hardware address which is supposed to be
 1393          * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
 1394          * operation on the interface SHOULD be disabled.
 1395          * [rfc2462bis-03 Section 5.4.5]
 1396          */
 1397         if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
 1398                 struct in6_addr in6;
 1399 
 1400                 /*
 1401                  * To avoid over-reaction, we only apply this logic when we are
 1402                  * very sure that hardware addresses are supposed to be unique.
 1403                  */
 1404                 switch (ifp->if_type) {
 1405                 case IFT_ETHER:
 1406                 case IFT_FDDI:
 1407                 case IFT_ATM:
 1408                 case IFT_IEEE1394:
 1409 #ifdef IFT_IEEE80211
 1410                 case IFT_IEEE80211:
 1411 #endif
 1412                         in6 = ia->ia_addr.sin6_addr;
 1413                         if (in6_get_hw_ifid(ifp, &in6) == 0 &&
 1414                             IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
 1415                                 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
 1416                                 log(LOG_ERR, "%s: possible hardware address "
 1417                                     "duplication detected, disable IPv6\n",
 1418                                     if_name(ifp));
 1419                         }
 1420                         break;
 1421                 }
 1422         }
 1423 
 1424         TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
 1425         free(dp, M_IP6NDP);
 1426         dp = NULL;
 1427         ifa_free(ifa);
 1428 }
 1429 
 1430 static void
 1431 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
 1432 {
 1433         struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
 1434         struct ifnet *ifp = ifa->ifa_ifp;
 1435 
 1436         dp->dad_ns_tcount++;
 1437         if ((ifp->if_flags & IFF_UP) == 0) {
 1438                 return;
 1439         }
 1440         if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
 1441                 return;
 1442         }
 1443 
 1444         dp->dad_ns_ocount++;
 1445         nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
 1446 }
 1447 
 1448 static void
 1449 nd6_dad_ns_input(struct ifaddr *ifa)
 1450 {
 1451         struct in6_ifaddr *ia;
 1452         struct ifnet *ifp;
 1453         const struct in6_addr *taddr6;
 1454         struct dadq *dp;
 1455         int duplicate;
 1456 
 1457         if (ifa == NULL)
 1458                 panic("ifa == NULL in nd6_dad_ns_input");
 1459 
 1460         ia = (struct in6_ifaddr *)ifa;
 1461         ifp = ifa->ifa_ifp;
 1462         taddr6 = &ia->ia_addr.sin6_addr;
 1463         duplicate = 0;
 1464         dp = nd6_dad_find(ifa);
 1465 
 1466         /* Quickhack - completely ignore DAD NS packets */
 1467         if (V_dad_ignore_ns) {
 1468                 char ip6buf[INET6_ADDRSTRLEN];
 1469                 nd6log((LOG_INFO,
 1470                     "nd6_dad_ns_input: ignoring DAD NS packet for "
 1471                     "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6),
 1472                     if_name(ifa->ifa_ifp)));
 1473                 return;
 1474         }
 1475 
 1476         /*
 1477          * if I'm yet to start DAD, someone else started using this address
 1478          * first.  I have a duplicate and you win.
 1479          */
 1480         if (dp == NULL || dp->dad_ns_ocount == 0)
 1481                 duplicate++;
 1482 
 1483         /* XXX more checks for loopback situation - see nd6_dad_timer too */
 1484 
 1485         if (duplicate) {
 1486                 dp = NULL;      /* will be freed in nd6_dad_duplicated() */
 1487                 nd6_dad_duplicated(ifa);
 1488         } else {
 1489                 /*
 1490                  * not sure if I got a duplicate.
 1491                  * increment ns count and see what happens.
 1492                  */
 1493                 if (dp)
 1494                         dp->dad_ns_icount++;
 1495         }
 1496 }
 1497 
 1498 static void
 1499 nd6_dad_na_input(struct ifaddr *ifa)
 1500 {
 1501         struct dadq *dp;
 1502 
 1503         if (ifa == NULL)
 1504                 panic("ifa == NULL in nd6_dad_na_input");
 1505 
 1506         dp = nd6_dad_find(ifa);
 1507         if (dp)
 1508                 dp->dad_na_icount++;
 1509 
 1510         /* remove the address. */
 1511         nd6_dad_duplicated(ifa);
 1512 }

Cache object: 7bffc69af837e386a4cf8441779feb07


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