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


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FreeBSD/Linux Kernel Cross Reference
sys/netinet6/icmp6.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: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
   30  */
   31 
   32 /*-
   33  * Copyright (c) 1982, 1986, 1988, 1993
   34  *      The Regents of the University of California.  All rights reserved.
   35  *
   36  * Redistribution and use in source and binary forms, with or without
   37  * modification, are permitted provided that the following conditions
   38  * are met:
   39  * 1. Redistributions of source code must retain the above copyright
   40  *    notice, this list of conditions and the following disclaimer.
   41  * 2. Redistributions in binary form must reproduce the above copyright
   42  *    notice, this list of conditions and the following disclaimer in the
   43  *    documentation and/or other materials provided with the distribution.
   44  * 4. Neither the name of the University nor the names of its contributors
   45  *    may be used to endorse or promote products derived from this software
   46  *    without specific prior written permission.
   47  *
   48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   58  * SUCH DAMAGE.
   59  *
   60  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
   61  */
   62 
   63 #include <sys/cdefs.h>
   64 __FBSDID("$FreeBSD$");
   65 
   66 #include "opt_inet.h"
   67 #include "opt_inet6.h"
   68 #include "opt_ipsec.h"
   69 
   70 #include <sys/param.h>
   71 #include <sys/domain.h>
   72 #include <sys/kernel.h>
   73 #include <sys/lock.h>
   74 #include <sys/malloc.h>
   75 #include <sys/mbuf.h>
   76 #include <sys/protosw.h>
   77 #include <sys/signalvar.h>
   78 #include <sys/socket.h>
   79 #include <sys/socketvar.h>
   80 #include <sys/sx.h>
   81 #include <sys/syslog.h>
   82 #include <sys/systm.h>
   83 #include <sys/time.h>
   84 
   85 #include <net/if.h>
   86 #include <net/if_dl.h>
   87 #include <net/if_types.h>
   88 #include <net/route.h>
   89 
   90 #include <netinet/in.h>
   91 #include <netinet/in_pcb.h>
   92 #include <netinet/in_var.h>
   93 #include <netinet/ip6.h>
   94 #include <netinet/icmp6.h>
   95 #include <netinet/tcp_var.h>
   96 #include <netinet6/in6_ifattach.h>
   97 #include <netinet6/in6_pcb.h>
   98 #include <netinet6/ip6protosw.h>
   99 #include <netinet6/ip6_var.h>
  100 #include <netinet6/scope6_var.h>
  101 #include <netinet6/mld6_var.h>
  102 #include <netinet6/nd6.h>
  103 
  104 #ifdef IPSEC
  105 #include <netipsec/ipsec.h>
  106 #include <netipsec/key.h>
  107 #endif
  108 
  109 extern struct domain inet6domain;
  110 
  111 struct icmp6stat icmp6stat;
  112 
  113 extern struct inpcbinfo ripcbinfo;
  114 extern struct inpcbhead ripcb;
  115 extern int icmp6errppslim;
  116 static int icmp6errpps_count = 0;
  117 static struct timeval icmp6errppslim_last;
  118 extern int icmp6_nodeinfo;
  119 
  120 static void icmp6_errcount(struct icmp6errstat *, int, int);
  121 static int icmp6_rip6_input(struct mbuf **, int);
  122 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
  123 static const char *icmp6_redirect_diag __P((struct in6_addr *,
  124         struct in6_addr *, struct in6_addr *));
  125 static struct mbuf *ni6_input(struct mbuf *, int);
  126 static struct mbuf *ni6_nametodns(const char *, int, int);
  127 static int ni6_dnsmatch(const char *, int, const char *, int);
  128 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
  129                           struct ifnet **, struct in6_addr *));
  130 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
  131                                 struct ifnet *, int));
  132 static int icmp6_notify_error(struct mbuf **, int, int, int);
  133 
  134 
  135 void
  136 icmp6_init(void)
  137 {
  138 
  139         mld6_init();
  140 }
  141 
  142 static void
  143 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
  144 {
  145         switch (type) {
  146         case ICMP6_DST_UNREACH:
  147                 switch (code) {
  148                 case ICMP6_DST_UNREACH_NOROUTE:
  149                         stat->icp6errs_dst_unreach_noroute++;
  150                         return;
  151                 case ICMP6_DST_UNREACH_ADMIN:
  152                         stat->icp6errs_dst_unreach_admin++;
  153                         return;
  154                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
  155                         stat->icp6errs_dst_unreach_beyondscope++;
  156                         return;
  157                 case ICMP6_DST_UNREACH_ADDR:
  158                         stat->icp6errs_dst_unreach_addr++;
  159                         return;
  160                 case ICMP6_DST_UNREACH_NOPORT:
  161                         stat->icp6errs_dst_unreach_noport++;
  162                         return;
  163                 }
  164                 break;
  165         case ICMP6_PACKET_TOO_BIG:
  166                 stat->icp6errs_packet_too_big++;
  167                 return;
  168         case ICMP6_TIME_EXCEEDED:
  169                 switch (code) {
  170                 case ICMP6_TIME_EXCEED_TRANSIT:
  171                         stat->icp6errs_time_exceed_transit++;
  172                         return;
  173                 case ICMP6_TIME_EXCEED_REASSEMBLY:
  174                         stat->icp6errs_time_exceed_reassembly++;
  175                         return;
  176                 }
  177                 break;
  178         case ICMP6_PARAM_PROB:
  179                 switch (code) {
  180                 case ICMP6_PARAMPROB_HEADER:
  181                         stat->icp6errs_paramprob_header++;
  182                         return;
  183                 case ICMP6_PARAMPROB_NEXTHEADER:
  184                         stat->icp6errs_paramprob_nextheader++;
  185                         return;
  186                 case ICMP6_PARAMPROB_OPTION:
  187                         stat->icp6errs_paramprob_option++;
  188                         return;
  189                 }
  190                 break;
  191         case ND_REDIRECT:
  192                 stat->icp6errs_redirect++;
  193                 return;
  194         }
  195         stat->icp6errs_unknown++;
  196 }
  197 
  198 /*
  199  * A wrapper function for icmp6_error() necessary when the erroneous packet
  200  * may not contain enough scope zone information.
  201  */
  202 void
  203 icmp6_error2(struct mbuf *m, int type, int code, int param,
  204     struct ifnet *ifp)
  205 {
  206         struct ip6_hdr *ip6;
  207 
  208         if (ifp == NULL)
  209                 return;
  210 
  211 #ifndef PULLDOWN_TEST
  212         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
  213 #else
  214         if (m->m_len < sizeof(struct ip6_hdr)) {
  215                 m = m_pullup(m, sizeof(struct ip6_hdr));
  216                 if (m == NULL)
  217                         return;
  218         }
  219 #endif
  220 
  221         ip6 = mtod(m, struct ip6_hdr *);
  222 
  223         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
  224                 return;
  225         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
  226                 return;
  227 
  228         icmp6_error(m, type, code, param);
  229 }
  230 
  231 /*
  232  * Generate an error packet of type error in response to bad IP6 packet.
  233  */
  234 void
  235 icmp6_error(struct mbuf *m, int type, int code, int param)
  236 {
  237         struct ip6_hdr *oip6, *nip6;
  238         struct icmp6_hdr *icmp6;
  239         u_int preplen;
  240         int off;
  241         int nxt;
  242 
  243         icmp6stat.icp6s_error++;
  244 
  245         /* count per-type-code statistics */
  246         icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
  247 
  248 #ifdef M_DECRYPTED      /*not openbsd*/
  249         if (m->m_flags & M_DECRYPTED) {
  250                 icmp6stat.icp6s_canterror++;
  251                 goto freeit;
  252         }
  253 #endif
  254 
  255 #ifndef PULLDOWN_TEST
  256         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
  257 #else
  258         if (m->m_len < sizeof(struct ip6_hdr)) {
  259                 m = m_pullup(m, sizeof(struct ip6_hdr));
  260                 if (m == NULL)
  261                         return;
  262         }
  263 #endif
  264         oip6 = mtod(m, struct ip6_hdr *);
  265 
  266         /*
  267          * If the destination address of the erroneous packet is a multicast
  268          * address, or the packet was sent using link-layer multicast,
  269          * we should basically suppress sending an error (RFC 2463, Section
  270          * 2.4).
  271          * We have two exceptions (the item e.2 in that section):
  272          * - the Packet Too Big message can be sent for path MTU discovery.
  273          * - the Parameter Problem Message that can be allowed an icmp6 error
  274          *   in the option type field.  This check has been done in
  275          *   ip6_unknown_opt(), so we can just check the type and code.
  276          */
  277         if ((m->m_flags & (M_BCAST|M_MCAST) ||
  278              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
  279             (type != ICMP6_PACKET_TOO_BIG &&
  280              (type != ICMP6_PARAM_PROB ||
  281               code != ICMP6_PARAMPROB_OPTION)))
  282                 goto freeit;
  283 
  284         /*
  285          * RFC 2463, 2.4 (e.5): source address check.
  286          * XXX: the case of anycast source?
  287          */
  288         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
  289             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
  290                 goto freeit;
  291 
  292         /*
  293          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
  294          * don't do it.
  295          */
  296         nxt = -1;
  297         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
  298         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
  299                 struct icmp6_hdr *icp;
  300 
  301 #ifndef PULLDOWN_TEST
  302                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
  303                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
  304 #else
  305                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
  306                         sizeof(*icp));
  307                 if (icp == NULL) {
  308                         icmp6stat.icp6s_tooshort++;
  309                         return;
  310                 }
  311 #endif
  312                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
  313                     icp->icmp6_type == ND_REDIRECT) {
  314                         /*
  315                          * ICMPv6 error
  316                          * Special case: for redirect (which is
  317                          * informational) we must not send icmp6 error.
  318                          */
  319                         icmp6stat.icp6s_canterror++;
  320                         goto freeit;
  321                 } else {
  322                         /* ICMPv6 informational - send the error */
  323                 }
  324         } else {
  325                 /* non-ICMPv6 - send the error */
  326         }
  327 
  328         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
  329 
  330         /* Finally, do rate limitation check. */
  331         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
  332                 icmp6stat.icp6s_toofreq++;
  333                 goto freeit;
  334         }
  335 
  336         /*
  337          * OK, ICMP6 can be generated.
  338          */
  339 
  340         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
  341                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
  342 
  343         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
  344         M_PREPEND(m, preplen, M_DONTWAIT);
  345         if (m && m->m_len < preplen)
  346                 m = m_pullup(m, preplen);
  347         if (m == NULL) {
  348                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
  349                 return;
  350         }
  351 
  352         nip6 = mtod(m, struct ip6_hdr *);
  353         nip6->ip6_src  = oip6->ip6_src;
  354         nip6->ip6_dst  = oip6->ip6_dst;
  355 
  356         in6_clearscope(&oip6->ip6_src);
  357         in6_clearscope(&oip6->ip6_dst);
  358 
  359         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
  360         icmp6->icmp6_type = type;
  361         icmp6->icmp6_code = code;
  362         icmp6->icmp6_pptr = htonl((u_int32_t)param);
  363 
  364         /*
  365          * icmp6_reflect() is designed to be in the input path.
  366          * icmp6_error() can be called from both input and output path,
  367          * and if we are in output path rcvif could contain bogus value.
  368          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
  369          * information in ip header (nip6).
  370          */
  371         m->m_pkthdr.rcvif = NULL;
  372 
  373         icmp6stat.icp6s_outhist[type]++;
  374         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
  375 
  376         return;
  377 
  378   freeit:
  379         /*
  380          * If we can't tell whether or not we can generate ICMP6, free it.
  381          */
  382         m_freem(m);
  383 }
  384 
  385 /*
  386  * Process a received ICMP6 message.
  387  */
  388 int
  389 icmp6_input(struct mbuf **mp, int *offp, int proto)
  390 {
  391         struct mbuf *m = *mp, *n;
  392         struct ip6_hdr *ip6, *nip6;
  393         struct icmp6_hdr *icmp6, *nicmp6;
  394         int off = *offp;
  395         int icmp6len = m->m_pkthdr.len - *offp;
  396         int code, sum, noff;
  397         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  398 
  399 #ifndef PULLDOWN_TEST
  400         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
  401         /* m might change if M_LOOP.  So, call mtod after this */
  402 #endif
  403 
  404         /*
  405          * Locate icmp6 structure in mbuf, and check
  406          * that not corrupted and of at least minimum length
  407          */
  408 
  409         ip6 = mtod(m, struct ip6_hdr *);
  410         if (icmp6len < sizeof(struct icmp6_hdr)) {
  411                 icmp6stat.icp6s_tooshort++;
  412                 goto freeit;
  413         }
  414 
  415         /*
  416          * calculate the checksum
  417          */
  418 #ifndef PULLDOWN_TEST
  419         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
  420 #else
  421         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
  422         if (icmp6 == NULL) {
  423                 icmp6stat.icp6s_tooshort++;
  424                 return IPPROTO_DONE;
  425         }
  426 #endif
  427         code = icmp6->icmp6_code;
  428 
  429         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
  430                 nd6log((LOG_ERR,
  431                     "ICMP6 checksum error(%d|%x) %s\n",
  432                     icmp6->icmp6_type, sum,
  433                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
  434                 icmp6stat.icp6s_checksum++;
  435                 goto freeit;
  436         }
  437 
  438         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
  439                 /*
  440                  * Deliver very specific ICMP6 type only.
  441                  * This is important to deliver TOOBIG.  Otherwise PMTUD
  442                  * will not work.
  443                  */
  444                 switch (icmp6->icmp6_type) {
  445                 case ICMP6_DST_UNREACH:
  446                 case ICMP6_PACKET_TOO_BIG:
  447                 case ICMP6_TIME_EXCEEDED:
  448                         break;
  449                 default:
  450                         goto freeit;
  451                 }
  452         }
  453 
  454         icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
  455         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
  456         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
  457                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
  458 
  459         switch (icmp6->icmp6_type) {
  460         case ICMP6_DST_UNREACH:
  461                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
  462                 switch (code) {
  463                 case ICMP6_DST_UNREACH_NOROUTE:
  464                         code = PRC_UNREACH_NET;
  465                         break;
  466                 case ICMP6_DST_UNREACH_ADMIN:
  467                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
  468                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
  469                         break;
  470                 case ICMP6_DST_UNREACH_ADDR:
  471                         code = PRC_HOSTDEAD;
  472                         break;
  473                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
  474                         /* I mean "source address was incorrect." */
  475                         code = PRC_PARAMPROB;
  476                         break;
  477                 case ICMP6_DST_UNREACH_NOPORT:
  478                         code = PRC_UNREACH_PORT;
  479                         break;
  480                 default:
  481                         goto badcode;
  482                 }
  483                 goto deliver;
  484                 break;
  485 
  486         case ICMP6_PACKET_TOO_BIG:
  487                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
  488 
  489                 /* validation is made in icmp6_mtudisc_update */
  490 
  491                 code = PRC_MSGSIZE;
  492 
  493                 /*
  494                  * Updating the path MTU will be done after examining
  495                  * intermediate extension headers.
  496                  */
  497                 goto deliver;
  498                 break;
  499 
  500         case ICMP6_TIME_EXCEEDED:
  501                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
  502                 switch (code) {
  503                 case ICMP6_TIME_EXCEED_TRANSIT:
  504                         code = PRC_TIMXCEED_INTRANS;
  505                         break;
  506                 case ICMP6_TIME_EXCEED_REASSEMBLY:
  507                         code = PRC_TIMXCEED_REASS;
  508                         break;
  509                 default:
  510                         goto badcode;
  511                 }
  512                 goto deliver;
  513                 break;
  514 
  515         case ICMP6_PARAM_PROB:
  516                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
  517                 switch (code) {
  518                 case ICMP6_PARAMPROB_NEXTHEADER:
  519                         code = PRC_UNREACH_PROTOCOL;
  520                         break;
  521                 case ICMP6_PARAMPROB_HEADER:
  522                 case ICMP6_PARAMPROB_OPTION:
  523                         code = PRC_PARAMPROB;
  524                         break;
  525                 default:
  526                         goto badcode;
  527                 }
  528                 goto deliver;
  529                 break;
  530 
  531         case ICMP6_ECHO_REQUEST:
  532                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
  533                 if (code != 0)
  534                         goto badcode;
  535                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
  536                         /* Give up remote */
  537                         break;
  538                 }
  539                 if ((n->m_flags & M_EXT) != 0
  540                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
  541                         struct mbuf *n0 = n;
  542                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
  543                         int n0len;
  544 
  545                         MGETHDR(n, M_DONTWAIT, n0->m_type);
  546                         n0len = n0->m_pkthdr.len;       /* save for use below */
  547                         if (n)
  548                                 M_MOVE_PKTHDR(n, n0);
  549                         if (n && maxlen >= MHLEN) {
  550                                 MCLGET(n, M_DONTWAIT);
  551                                 if ((n->m_flags & M_EXT) == 0) {
  552                                         m_free(n);
  553                                         n = NULL;
  554                                 }
  555                         }
  556                         if (n == NULL) {
  557                                 /* Give up remote */
  558                                 m_freem(n0);
  559                                 break;
  560                         }
  561                         /*
  562                          * Copy IPv6 and ICMPv6 only.
  563                          */
  564                         nip6 = mtod(n, struct ip6_hdr *);
  565                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
  566                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
  567                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
  568                         noff = sizeof(struct ip6_hdr);
  569                         /* new mbuf contains only ipv6+icmpv6 headers */
  570                         n->m_len = noff + sizeof(struct icmp6_hdr);
  571                         /*
  572                          * Adjust mbuf.  ip6_plen will be adjusted in
  573                          * ip6_output().
  574                          */
  575                         m_adj(n0, off + sizeof(struct icmp6_hdr));
  576                         /* recalculate complete packet size */
  577                         n->m_pkthdr.len = n0len + (noff - off);
  578                         n->m_next = n0;
  579                 } else {
  580                         nip6 = mtod(n, struct ip6_hdr *);
  581                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
  582                             sizeof(*nicmp6));
  583                         noff = off;
  584                 }
  585                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
  586                 nicmp6->icmp6_code = 0;
  587                 if (n) {
  588                         icmp6stat.icp6s_reflect++;
  589                         icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
  590                         icmp6_reflect(n, noff);
  591                 }
  592                 break;
  593 
  594         case ICMP6_ECHO_REPLY:
  595                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
  596                 if (code != 0)
  597                         goto badcode;
  598                 break;
  599 
  600         case MLD_LISTENER_QUERY:
  601         case MLD_LISTENER_REPORT:
  602                 if (icmp6len < sizeof(struct mld_hdr))
  603                         goto badlen;
  604                 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
  605                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
  606                 else
  607                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
  608                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
  609                         /* give up local */
  610                         mld6_input(m, off);
  611                         m = NULL;
  612                         goto freeit;
  613                 }
  614                 mld6_input(n, off);
  615                 /* m stays. */
  616                 break;
  617 
  618         case MLD_LISTENER_DONE:
  619                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
  620                 if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
  621                         goto badlen;
  622                 break;          /* nothing to be done in kernel */
  623 
  624         case MLD_MTRACE_RESP:
  625         case MLD_MTRACE:
  626                 /* XXX: these two are experimental.  not officially defined. */
  627                 /* XXX: per-interface statistics? */
  628                 break;          /* just pass it to applications */
  629 
  630         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
  631             {
  632                 enum { WRU, FQDN } mode;
  633 
  634                 if (!icmp6_nodeinfo)
  635                         break;
  636 
  637                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
  638                         mode = WRU;
  639                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
  640                         mode = FQDN;
  641                 else
  642                         goto badlen;
  643 
  644 #define hostnamelen     strlen(hostname)
  645                 if (mode == FQDN) {
  646 #ifndef PULLDOWN_TEST
  647                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
  648                             IPPROTO_DONE);
  649 #endif
  650                         n = m_copy(m, 0, M_COPYALL);
  651                         if (n)
  652                                 n = ni6_input(n, off);
  653                         /* XXX meaningless if n == NULL */
  654                         noff = sizeof(struct ip6_hdr);
  655                 } else {
  656                         u_char *p;
  657                         int maxlen, maxhlen;
  658 
  659                         /*
  660                          * XXX: this combination of flags is pointless,
  661                          * but should we keep this for compatibility?
  662                          */
  663                         if ((icmp6_nodeinfo & 5) != 5)
  664                                 break;
  665 
  666                         if (code != 0)
  667                                 goto badcode;
  668                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
  669                         if (maxlen >= MCLBYTES) {
  670                                 /* Give up remote */
  671                                 break;
  672                         }
  673                         MGETHDR(n, M_DONTWAIT, m->m_type);
  674                         if (n && maxlen > MHLEN) {
  675                                 MCLGET(n, M_DONTWAIT);
  676                                 if ((n->m_flags & M_EXT) == 0) {
  677                                         m_free(n);
  678                                         n = NULL;
  679                                 }
  680                         }
  681                         if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
  682                                 /*
  683                                  * Previous code did a blind M_COPY_PKTHDR
  684                                  * and said "just for rcvif".  If true, then
  685                                  * we could tolerate the dup failing (due to
  686                                  * the deep copy of the tag chain).  For now
  687                                  * be conservative and just fail.
  688                                  */
  689                                 m_free(n);
  690                                 n = NULL;
  691                         }
  692                         if (n == NULL) {
  693                                 /* Give up remote */
  694                                 break;
  695                         }
  696                         n->m_pkthdr.rcvif = NULL;
  697                         n->m_len = 0;
  698                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
  699                         if (maxhlen > hostnamelen)
  700                                 maxhlen = hostnamelen;
  701                         /*
  702                          * Copy IPv6 and ICMPv6 only.
  703                          */
  704                         nip6 = mtod(n, struct ip6_hdr *);
  705                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
  706                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
  707                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
  708                         p = (u_char *)(nicmp6 + 1);
  709                         bzero(p, 4);
  710                         bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
  711                         noff = sizeof(struct ip6_hdr);
  712                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
  713                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
  714                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
  715                         nicmp6->icmp6_code = 0;
  716                 }
  717 #undef hostnamelen
  718                 if (n) {
  719                         icmp6stat.icp6s_reflect++;
  720                         icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
  721                         icmp6_reflect(n, noff);
  722                 }
  723                 break;
  724             }
  725 
  726         case ICMP6_WRUREPLY:
  727                 if (code != 0)
  728                         goto badcode;
  729                 break;
  730 
  731         case ND_ROUTER_SOLICIT:
  732                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
  733                 if (code != 0)
  734                         goto badcode;
  735                 if (icmp6len < sizeof(struct nd_router_solicit))
  736                         goto badlen;
  737                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
  738                         /* give up local */
  739                         nd6_rs_input(m, off, icmp6len);
  740                         m = NULL;
  741                         goto freeit;
  742                 }
  743                 nd6_rs_input(n, off, icmp6len);
  744                 /* m stays. */
  745                 break;
  746 
  747         case ND_ROUTER_ADVERT:
  748                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
  749                 if (code != 0)
  750                         goto badcode;
  751                 if (icmp6len < sizeof(struct nd_router_advert))
  752                         goto badlen;
  753                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
  754                         /* give up local */
  755                         nd6_ra_input(m, off, icmp6len);
  756                         m = NULL;
  757                         goto freeit;
  758                 }
  759                 nd6_ra_input(n, off, icmp6len);
  760                 /* m stays. */
  761                 break;
  762 
  763         case ND_NEIGHBOR_SOLICIT:
  764                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
  765                 if (code != 0)
  766                         goto badcode;
  767                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
  768                         goto badlen;
  769                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
  770                         /* give up local */
  771                         nd6_ns_input(m, off, icmp6len);
  772                         m = NULL;
  773                         goto freeit;
  774                 }
  775                 nd6_ns_input(n, off, icmp6len);
  776                 /* m stays. */
  777                 break;
  778 
  779         case ND_NEIGHBOR_ADVERT:
  780                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
  781                 if (code != 0)
  782                         goto badcode;
  783                 if (icmp6len < sizeof(struct nd_neighbor_advert))
  784                         goto badlen;
  785                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
  786                         /* give up local */
  787                         nd6_na_input(m, off, icmp6len);
  788                         m = NULL;
  789                         goto freeit;
  790                 }
  791                 nd6_na_input(n, off, icmp6len);
  792                 /* m stays. */
  793                 break;
  794 
  795         case ND_REDIRECT:
  796                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
  797                 if (code != 0)
  798                         goto badcode;
  799                 if (icmp6len < sizeof(struct nd_redirect))
  800                         goto badlen;
  801                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
  802                         /* give up local */
  803                         icmp6_redirect_input(m, off);
  804                         m = NULL;
  805                         goto freeit;
  806                 }
  807                 icmp6_redirect_input(n, off);
  808                 /* m stays. */
  809                 break;
  810 
  811         case ICMP6_ROUTER_RENUMBERING:
  812                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
  813                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
  814                         goto badcode;
  815                 if (icmp6len < sizeof(struct icmp6_router_renum))
  816                         goto badlen;
  817                 break;
  818 
  819         default:
  820                 nd6log((LOG_DEBUG,
  821                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
  822                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  823                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
  824                     m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
  825                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
  826                         /* ICMPv6 error: MUST deliver it by spec... */
  827                         code = PRC_NCMDS;
  828                         /* deliver */
  829                 } else {
  830                         /* ICMPv6 informational: MUST not deliver */
  831                         break;
  832                 }
  833         deliver:
  834                 if (icmp6_notify_error(&m, off, icmp6len, code)) {
  835                         /* In this case, m should've been freed. */
  836                         return (IPPROTO_DONE);
  837                 }
  838                 break;
  839 
  840         badcode:
  841                 icmp6stat.icp6s_badcode++;
  842                 break;
  843 
  844         badlen:
  845                 icmp6stat.icp6s_badlen++;
  846                 break;
  847         }
  848 
  849         /* deliver the packet to appropriate sockets */
  850         icmp6_rip6_input(&m, *offp);
  851 
  852         return IPPROTO_DONE;
  853 
  854  freeit:
  855         m_freem(m);
  856         return IPPROTO_DONE;
  857 }
  858 
  859 static int
  860 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
  861 {
  862         struct mbuf *m = *mp;
  863         struct icmp6_hdr *icmp6;
  864         struct ip6_hdr *eip6;
  865         u_int32_t notifymtu;
  866         struct sockaddr_in6 icmp6src, icmp6dst;
  867 
  868         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
  869                 icmp6stat.icp6s_tooshort++;
  870                 goto freeit;
  871         }
  872 #ifndef PULLDOWN_TEST
  873         IP6_EXTHDR_CHECK(m, off,
  874             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
  875         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
  876 #else
  877         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
  878             sizeof(*icmp6) + sizeof(struct ip6_hdr));
  879         if (icmp6 == NULL) {
  880                 icmp6stat.icp6s_tooshort++;
  881                 return (-1);
  882         }
  883 #endif
  884         eip6 = (struct ip6_hdr *)(icmp6 + 1);
  885 
  886         /* Detect the upper level protocol */
  887         {
  888                 void (*ctlfunc)(int, struct sockaddr *, void *);
  889                 u_int8_t nxt = eip6->ip6_nxt;
  890                 int eoff = off + sizeof(struct icmp6_hdr) +
  891                     sizeof(struct ip6_hdr);
  892                 struct ip6ctlparam ip6cp;
  893                 struct in6_addr *finaldst = NULL;
  894                 int icmp6type = icmp6->icmp6_type;
  895                 struct ip6_frag *fh;
  896                 struct ip6_rthdr *rth;
  897                 struct ip6_rthdr0 *rth0;
  898                 int rthlen;
  899 
  900                 while (1) { /* XXX: should avoid infinite loop explicitly? */
  901                         struct ip6_ext *eh;
  902 
  903                         switch (nxt) {
  904                         case IPPROTO_HOPOPTS:
  905                         case IPPROTO_DSTOPTS:
  906                         case IPPROTO_AH:
  907 #ifndef PULLDOWN_TEST
  908                                 IP6_EXTHDR_CHECK(m, 0,
  909                                     eoff + sizeof(struct ip6_ext), -1);
  910                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
  911 #else
  912                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
  913                                     eoff, sizeof(*eh));
  914                                 if (eh == NULL) {
  915                                         icmp6stat.icp6s_tooshort++;
  916                                         return (-1);
  917                                 }
  918 #endif
  919 
  920                                 if (nxt == IPPROTO_AH)
  921                                         eoff += (eh->ip6e_len + 2) << 2;
  922                                 else
  923                                         eoff += (eh->ip6e_len + 1) << 3;
  924                                 nxt = eh->ip6e_nxt;
  925                                 break;
  926                         case IPPROTO_ROUTING:
  927                                 /*
  928                                  * When the erroneous packet contains a
  929                                  * routing header, we should examine the
  930                                  * header to determine the final destination.
  931                                  * Otherwise, we can't properly update
  932                                  * information that depends on the final
  933                                  * destination (e.g. path MTU).
  934                                  */
  935 #ifndef PULLDOWN_TEST
  936                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
  937                                 rth = (struct ip6_rthdr *)
  938                                     (mtod(m, caddr_t) + eoff);
  939 #else
  940                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
  941                                     eoff, sizeof(*rth));
  942                                 if (rth == NULL) {
  943                                         icmp6stat.icp6s_tooshort++;
  944                                         return (-1);
  945                                 }
  946 #endif
  947                                 rthlen = (rth->ip6r_len + 1) << 3;
  948                                 /*
  949                                  * XXX: currently there is no
  950                                  * officially defined type other
  951                                  * than type-0.
  952                                  * Note that if the segment left field
  953                                  * is 0, all intermediate hops must
  954                                  * have been passed.
  955                                  */
  956                                 if (rth->ip6r_segleft &&
  957                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
  958                                         int hops;
  959 
  960 #ifndef PULLDOWN_TEST
  961                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
  962                                         rth0 = (struct ip6_rthdr0 *)
  963                                             (mtod(m, caddr_t) + eoff);
  964 #else
  965                                         IP6_EXTHDR_GET(rth0,
  966                                             struct ip6_rthdr0 *, m,
  967                                             eoff, rthlen);
  968                                         if (rth0 == NULL) {
  969                                                 icmp6stat.icp6s_tooshort++;
  970                                                 return (-1);
  971                                         }
  972 #endif
  973                                         /* just ignore a bogus header */
  974                                         if ((rth0->ip6r0_len % 2) == 0 &&
  975                                             (hops = rth0->ip6r0_len/2))
  976                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
  977                                 }
  978                                 eoff += rthlen;
  979                                 nxt = rth->ip6r_nxt;
  980                                 break;
  981                         case IPPROTO_FRAGMENT:
  982 #ifndef PULLDOWN_TEST
  983                                 IP6_EXTHDR_CHECK(m, 0, eoff +
  984                                     sizeof(struct ip6_frag), -1);
  985                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
  986                                     eoff);
  987 #else
  988                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
  989                                     eoff, sizeof(*fh));
  990                                 if (fh == NULL) {
  991                                         icmp6stat.icp6s_tooshort++;
  992                                         return (-1);
  993                                 }
  994 #endif
  995                                 /*
  996                                  * Data after a fragment header is meaningless
  997                                  * unless it is the first fragment, but
  998                                  * we'll go to the notify label for path MTU
  999                                  * discovery.
 1000                                  */
 1001                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
 1002                                         goto notify;
 1003 
 1004                                 eoff += sizeof(struct ip6_frag);
 1005                                 nxt = fh->ip6f_nxt;
 1006                                 break;
 1007                         default:
 1008                                 /*
 1009                                  * This case includes ESP and the No Next
 1010                                  * Header.  In such cases going to the notify
 1011                                  * label does not have any meaning
 1012                                  * (i.e. ctlfunc will be NULL), but we go
 1013                                  * anyway since we might have to update
 1014                                  * path MTU information.
 1015                                  */
 1016                                 goto notify;
 1017                         }
 1018                 }
 1019           notify:
 1020 #ifndef PULLDOWN_TEST
 1021                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 1022 #else
 1023                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 1024                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
 1025                 if (icmp6 == NULL) {
 1026                         icmp6stat.icp6s_tooshort++;
 1027                         return (-1);
 1028                 }
 1029 #endif
 1030 
 1031                 /*
 1032                  * retrieve parameters from the inner IPv6 header, and convert
 1033                  * them into sockaddr structures.
 1034                  * XXX: there is no guarantee that the source or destination
 1035                  * addresses of the inner packet are in the same scope as
 1036                  * the addresses of the icmp packet.  But there is no other
 1037                  * way to determine the zone.
 1038                  */
 1039                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
 1040 
 1041                 bzero(&icmp6dst, sizeof(icmp6dst));
 1042                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
 1043                 icmp6dst.sin6_family = AF_INET6;
 1044                 if (finaldst == NULL)
 1045                         icmp6dst.sin6_addr = eip6->ip6_dst;
 1046                 else
 1047                         icmp6dst.sin6_addr = *finaldst;
 1048                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
 1049                         goto freeit;
 1050                 bzero(&icmp6src, sizeof(icmp6src));
 1051                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
 1052                 icmp6src.sin6_family = AF_INET6;
 1053                 icmp6src.sin6_addr = eip6->ip6_src;
 1054                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
 1055                         goto freeit;
 1056                 icmp6src.sin6_flowinfo =
 1057                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
 1058 
 1059                 if (finaldst == NULL)
 1060                         finaldst = &eip6->ip6_dst;
 1061                 ip6cp.ip6c_m = m;
 1062                 ip6cp.ip6c_icmp6 = icmp6;
 1063                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
 1064                 ip6cp.ip6c_off = eoff;
 1065                 ip6cp.ip6c_finaldst = finaldst;
 1066                 ip6cp.ip6c_src = &icmp6src;
 1067                 ip6cp.ip6c_nxt = nxt;
 1068 
 1069                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
 1070                         notifymtu = ntohl(icmp6->icmp6_mtu);
 1071                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
 1072                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
 1073                 }
 1074 
 1075                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
 1076                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
 1077                 if (ctlfunc) {
 1078                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
 1079                             &ip6cp);
 1080                 }
 1081         }
 1082         *mp = m;
 1083         return (0);
 1084 
 1085   freeit:
 1086         m_freem(m);
 1087         return (-1);
 1088 }
 1089 
 1090 void
 1091 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
 1092 {
 1093         struct in6_addr *dst = ip6cp->ip6c_finaldst;
 1094         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
 1095         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
 1096         u_int mtu = ntohl(icmp6->icmp6_mtu);
 1097         struct in_conninfo inc;
 1098 
 1099 #if 0
 1100         /*
 1101          * RFC2460 section 5, last paragraph.
 1102          * even though minimum link MTU for IPv6 is IPV6_MMTU,
 1103          * we may see ICMPv6 too big with mtu < IPV6_MMTU
 1104          * due to packet translator in the middle.
 1105          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
 1106          * special handling.
 1107          */
 1108         if (mtu < IPV6_MMTU)
 1109                 return;
 1110 #endif
 1111 
 1112         /*
 1113          * we reject ICMPv6 too big with abnormally small value.
 1114          * XXX what is the good definition of "abnormally small"?
 1115          */
 1116         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
 1117                 return;
 1118 
 1119         if (!validated)
 1120                 return;
 1121 
 1122         /*
 1123          * In case the suggested mtu is less than IPV6_MMTU, we
 1124          * only need to remember that it was for above mentioned
 1125          * "alwaysfrag" case.
 1126          * Try to be as close to the spec as possible.
 1127          */
 1128         if (mtu < IPV6_MMTU)
 1129                 mtu = IPV6_MMTU - 8;
 1130 
 1131         bzero(&inc, sizeof(inc));
 1132         inc.inc_flags |= INC_ISIPV6;
 1133         inc.inc6_faddr = *dst;
 1134         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
 1135                 return;
 1136 
 1137         if (mtu < tcp_maxmtu6(&inc, NULL)) {
 1138                 tcp_hc_updatemtu(&inc, mtu);
 1139                 icmp6stat.icp6s_pmtuchg++;
 1140         }
 1141 }
 1142 
 1143 /*
 1144  * Process a Node Information Query packet, based on
 1145  * draft-ietf-ipngwg-icmp-name-lookups-07.
 1146  *
 1147  * Spec incompatibilities:
 1148  * - IPv6 Subject address handling
 1149  * - IPv4 Subject address handling support missing
 1150  * - Proxy reply (answer even if it's not for me)
 1151  * - joins NI group address at in6_ifattach() time only, does not cope
 1152  *   with hostname changes by sethostname(3)
 1153  */
 1154 #define hostnamelen     strlen(hostname)
 1155 static struct mbuf *
 1156 ni6_input(struct mbuf *m, int off)
 1157 {
 1158         struct icmp6_nodeinfo *ni6, *nni6;
 1159         struct mbuf *n = NULL;
 1160         u_int16_t qtype;
 1161         int subjlen;
 1162         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
 1163         struct ni_reply_fqdn *fqdn;
 1164         int addrs;              /* for NI_QTYPE_NODEADDR */
 1165         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
 1166         struct in6_addr in6_subj; /* subject address */
 1167         struct ip6_hdr *ip6;
 1168         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
 1169         char *subj = NULL;
 1170         struct in6_ifaddr *ia6 = NULL;
 1171 
 1172         ip6 = mtod(m, struct ip6_hdr *);
 1173 #ifndef PULLDOWN_TEST
 1174         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
 1175 #else
 1176         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
 1177         if (ni6 == NULL) {
 1178                 /* m is already reclaimed */
 1179                 return (NULL);
 1180         }
 1181 #endif
 1182 
 1183         /*
 1184          * Validate IPv6 source address.
 1185          * The default configuration MUST be to refuse answering queries from
 1186          * global-scope addresses according to RFC4602.
 1187          * Notes:
 1188          *  - it's not very clear what "refuse" means; this implementation
 1189          *    simply drops it.
 1190          *  - it's not very easy to identify global-scope (unicast) addresses
 1191          *    since there are many prefixes for them.  It should be safer
 1192          *    and in practice sufficient to check "all" but loopback and
 1193          *    link-local (note that site-local unicast was deprecated and
 1194          *    ULA is defined as global scope-wise)
 1195          */
 1196         if ((icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
 1197             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
 1198             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
 1199                 goto bad;
 1200 
 1201         /*
 1202          * Validate IPv6 destination address.
 1203          *
 1204          * The Responder must discard the Query without further processing
 1205          * unless it is one of the Responder's unicast or anycast addresses, or
 1206          * a link-local scope multicast address which the Responder has joined.
 1207          * [RFC4602, Section 5.]
 1208          */
 1209         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 1210                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
 1211                         goto bad;
 1212                 /* else it's a link-local multicast, fine */
 1213         } else {                /* unicast or anycast */
 1214                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
 1215                         goto bad; /* XXX impossible */
 1216 
 1217                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
 1218                     !(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
 1219                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
 1220                                 "a temporary address in %s:%d",
 1221                                __FILE__, __LINE__));
 1222                         goto bad;
 1223                 }
 1224         }
 1225 
 1226         /* validate query Subject field. */
 1227         qtype = ntohs(ni6->ni_qtype);
 1228         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
 1229         switch (qtype) {
 1230         case NI_QTYPE_NOOP:
 1231         case NI_QTYPE_SUPTYPES:
 1232                 /* 07 draft */
 1233                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
 1234                         break;
 1235                 /* FALLTHROUGH */
 1236         case NI_QTYPE_FQDN:
 1237         case NI_QTYPE_NODEADDR:
 1238         case NI_QTYPE_IPV4ADDR:
 1239                 switch (ni6->ni_code) {
 1240                 case ICMP6_NI_SUBJ_IPV6:
 1241 #if ICMP6_NI_SUBJ_IPV6 != 0
 1242                 case 0:
 1243 #endif
 1244                         /*
 1245                          * backward compatibility - try to accept 03 draft
 1246                          * format, where no Subject is present.
 1247                          */
 1248                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
 1249                             subjlen == 0) {
 1250                                 oldfqdn++;
 1251                                 break;
 1252                         }
 1253 #if ICMP6_NI_SUBJ_IPV6 != 0
 1254                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
 1255                                 goto bad;
 1256 #endif
 1257 
 1258                         if (subjlen != sizeof(struct in6_addr))
 1259                                 goto bad;
 1260 
 1261                         /*
 1262                          * Validate Subject address.
 1263                          *
 1264                          * Not sure what exactly "address belongs to the node"
 1265                          * means in the spec, is it just unicast, or what?
 1266                          *
 1267                          * At this moment we consider Subject address as
 1268                          * "belong to the node" if the Subject address equals
 1269                          * to the IPv6 destination address; validation for
 1270                          * IPv6 destination address should have done enough
 1271                          * check for us.
 1272                          *
 1273                          * We do not do proxy at this moment.
 1274                          */
 1275                         /* m_pulldown instead of copy? */
 1276                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
 1277                             subjlen, (caddr_t)&in6_subj);
 1278                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
 1279                                 goto bad;
 1280 
 1281                         subj = (char *)&in6_subj;
 1282                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
 1283                                 break;
 1284 
 1285                         /*
 1286                          * XXX if we are to allow other cases, we should really
 1287                          * be careful about scope here.
 1288                          * basically, we should disallow queries toward IPv6
 1289                          * destination X with subject Y,
 1290                          * if scope(X) > scope(Y).
 1291                          * if we allow scope(X) > scope(Y), it will result in
 1292                          * information leakage across scope boundary.
 1293                          */
 1294                         goto bad;
 1295 
 1296                 case ICMP6_NI_SUBJ_FQDN:
 1297                         /*
 1298                          * Validate Subject name with gethostname(3).
 1299                          *
 1300                          * The behavior may need some debate, since:
 1301                          * - we are not sure if the node has FQDN as
 1302                          *   hostname (returned by gethostname(3)).
 1303                          * - the code does wildcard match for truncated names.
 1304                          *   however, we are not sure if we want to perform
 1305                          *   wildcard match, if gethostname(3) side has
 1306                          *   truncated hostname.
 1307                          */
 1308                         n = ni6_nametodns(hostname, hostnamelen, 0);
 1309                         if (!n || n->m_next || n->m_len == 0)
 1310                                 goto bad;
 1311                         IP6_EXTHDR_GET(subj, char *, m,
 1312                             off + sizeof(struct icmp6_nodeinfo), subjlen);
 1313                         if (subj == NULL)
 1314                                 goto bad;
 1315                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
 1316                             n->m_len)) {
 1317                                 goto bad;
 1318                         }
 1319                         m_freem(n);
 1320                         n = NULL;
 1321                         break;
 1322 
 1323                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
 1324                 default:
 1325                         goto bad;
 1326                 }
 1327                 break;
 1328         }
 1329 
 1330         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
 1331         switch (qtype) {
 1332         case NI_QTYPE_FQDN:
 1333                 if ((icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
 1334                         goto bad;
 1335                 break;
 1336         case NI_QTYPE_NODEADDR:
 1337         case NI_QTYPE_IPV4ADDR:
 1338                 if ((icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
 1339                         goto bad;
 1340                 break;
 1341         }
 1342 
 1343         /* guess reply length */
 1344         switch (qtype) {
 1345         case NI_QTYPE_NOOP:
 1346                 break;          /* no reply data */
 1347         case NI_QTYPE_SUPTYPES:
 1348                 replylen += sizeof(u_int32_t);
 1349                 break;
 1350         case NI_QTYPE_FQDN:
 1351                 /* XXX will append an mbuf */
 1352                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
 1353                 break;
 1354         case NI_QTYPE_NODEADDR:
 1355                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
 1356                 if ((replylen += addrs * (sizeof(struct in6_addr) +
 1357                     sizeof(u_int32_t))) > MCLBYTES)
 1358                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
 1359                 break;
 1360         case NI_QTYPE_IPV4ADDR:
 1361                 /* unsupported - should respond with unknown Qtype? */
 1362                 break;
 1363         default:
 1364                 /*
 1365                  * XXX: We must return a reply with the ICMP6 code
 1366                  * `unknown Qtype' in this case.  However we regard the case
 1367                  * as an FQDN query for backward compatibility.
 1368                  * Older versions set a random value to this field,
 1369                  * so it rarely varies in the defined qtypes.
 1370                  * But the mechanism is not reliable...
 1371                  * maybe we should obsolete older versions.
 1372                  */
 1373                 qtype = NI_QTYPE_FQDN;
 1374                 /* XXX will append an mbuf */
 1375                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
 1376                 oldfqdn++;
 1377                 break;
 1378         }
 1379 
 1380         /* allocate an mbuf to reply. */
 1381         MGETHDR(n, M_DONTWAIT, m->m_type);
 1382         if (n == NULL) {
 1383                 m_freem(m);
 1384                 return (NULL);
 1385         }
 1386         M_MOVE_PKTHDR(n, m); /* just for recvif */
 1387         if (replylen > MHLEN) {
 1388                 if (replylen > MCLBYTES) {
 1389                         /*
 1390                          * XXX: should we try to allocate more? But MCLBYTES
 1391                          * is probably much larger than IPV6_MMTU...
 1392                          */
 1393                         goto bad;
 1394                 }
 1395                 MCLGET(n, M_DONTWAIT);
 1396                 if ((n->m_flags & M_EXT) == 0) {
 1397                         goto bad;
 1398                 }
 1399         }
 1400         n->m_pkthdr.len = n->m_len = replylen;
 1401 
 1402         /* copy mbuf header and IPv6 + Node Information base headers */
 1403         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
 1404         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
 1405         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
 1406 
 1407         /* qtype dependent procedure */
 1408         switch (qtype) {
 1409         case NI_QTYPE_NOOP:
 1410                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1411                 nni6->ni_flags = 0;
 1412                 break;
 1413         case NI_QTYPE_SUPTYPES:
 1414         {
 1415                 u_int32_t v;
 1416                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1417                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
 1418                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
 1419                 v = (u_int32_t)htonl(0x0000000f);
 1420                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
 1421                 break;
 1422         }
 1423         case NI_QTYPE_FQDN:
 1424                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1425                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
 1426                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
 1427                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
 1428                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
 1429                 /*
 1430                  * XXX do we really have FQDN in variable "hostname"?
 1431                  */
 1432                 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
 1433                 if (n->m_next == NULL)
 1434                         goto bad;
 1435                 /* XXX we assume that n->m_next is not a chain */
 1436                 if (n->m_next->m_next != NULL)
 1437                         goto bad;
 1438                 n->m_pkthdr.len += n->m_next->m_len;
 1439                 break;
 1440         case NI_QTYPE_NODEADDR:
 1441         {
 1442                 int lenlim, copied;
 1443 
 1444                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1445                 n->m_pkthdr.len = n->m_len =
 1446                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
 1447                 lenlim = M_TRAILINGSPACE(n);
 1448                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
 1449                 /* XXX: reset mbuf length */
 1450                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 1451                     sizeof(struct icmp6_nodeinfo) + copied;
 1452                 break;
 1453         }
 1454         default:
 1455                 break;          /* XXX impossible! */
 1456         }
 1457 
 1458         nni6->ni_type = ICMP6_NI_REPLY;
 1459         m_freem(m);
 1460         return (n);
 1461 
 1462   bad:
 1463         m_freem(m);
 1464         if (n)
 1465                 m_freem(n);
 1466         return (NULL);
 1467 }
 1468 #undef hostnamelen
 1469 
 1470 /*
 1471  * make a mbuf with DNS-encoded string.  no compression support.
 1472  *
 1473  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
 1474  * treated as truncated name (two \0 at the end).  this is a wild guess.
 1475  *
 1476  * old - return pascal string if non-zero
 1477  */
 1478 static struct mbuf *
 1479 ni6_nametodns(const char *name, int namelen, int old)
 1480 {
 1481         struct mbuf *m;
 1482         char *cp, *ep;
 1483         const char *p, *q;
 1484         int i, len, nterm;
 1485 
 1486         if (old)
 1487                 len = namelen + 1;
 1488         else
 1489                 len = MCLBYTES;
 1490 
 1491         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
 1492         MGET(m, M_DONTWAIT, MT_DATA);
 1493         if (m && len > MLEN) {
 1494                 MCLGET(m, M_DONTWAIT);
 1495                 if ((m->m_flags & M_EXT) == 0)
 1496                         goto fail;
 1497         }
 1498         if (!m)
 1499                 goto fail;
 1500         m->m_next = NULL;
 1501 
 1502         if (old) {
 1503                 m->m_len = len;
 1504                 *mtod(m, char *) = namelen;
 1505                 bcopy(name, mtod(m, char *) + 1, namelen);
 1506                 return m;
 1507         } else {
 1508                 m->m_len = 0;
 1509                 cp = mtod(m, char *);
 1510                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
 1511 
 1512                 /* if not certain about my name, return empty buffer */
 1513                 if (namelen == 0)
 1514                         return m;
 1515 
 1516                 /*
 1517                  * guess if it looks like shortened hostname, or FQDN.
 1518                  * shortened hostname needs two trailing "\0".
 1519                  */
 1520                 i = 0;
 1521                 for (p = name; p < name + namelen; p++) {
 1522                         if (*p && *p == '.')
 1523                                 i++;
 1524                 }
 1525                 if (i < 2)
 1526                         nterm = 2;
 1527                 else
 1528                         nterm = 1;
 1529 
 1530                 p = name;
 1531                 while (cp < ep && p < name + namelen) {
 1532                         i = 0;
 1533                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
 1534                                 i++;
 1535                         /* result does not fit into mbuf */
 1536                         if (cp + i + 1 >= ep)
 1537                                 goto fail;
 1538                         /*
 1539                          * DNS label length restriction, RFC1035 page 8.
 1540                          * "i == 0" case is included here to avoid returning
 1541                          * 0-length label on "foo..bar".
 1542                          */
 1543                         if (i <= 0 || i >= 64)
 1544                                 goto fail;
 1545                         *cp++ = i;
 1546                         bcopy(p, cp, i);
 1547                         cp += i;
 1548                         p = q;
 1549                         if (p < name + namelen && *p == '.')
 1550                                 p++;
 1551                 }
 1552                 /* termination */
 1553                 if (cp + nterm >= ep)
 1554                         goto fail;
 1555                 while (nterm-- > 0)
 1556                         *cp++ = '\0';
 1557                 m->m_len = cp - mtod(m, char *);
 1558                 return m;
 1559         }
 1560 
 1561         panic("should not reach here");
 1562         /* NOTREACHED */
 1563 
 1564  fail:
 1565         if (m)
 1566                 m_freem(m);
 1567         return NULL;
 1568 }
 1569 
 1570 /*
 1571  * check if two DNS-encoded string matches.  takes care of truncated
 1572  * form (with \0\0 at the end).  no compression support.
 1573  * XXX upper/lowercase match (see RFC2065)
 1574  */
 1575 static int
 1576 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
 1577 {
 1578         const char *a0, *b0;
 1579         int l;
 1580 
 1581         /* simplest case - need validation? */
 1582         if (alen == blen && bcmp(a, b, alen) == 0)
 1583                 return 1;
 1584 
 1585         a0 = a;
 1586         b0 = b;
 1587 
 1588         /* termination is mandatory */
 1589         if (alen < 2 || blen < 2)
 1590                 return 0;
 1591         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
 1592                 return 0;
 1593         alen--;
 1594         blen--;
 1595 
 1596         while (a - a0 < alen && b - b0 < blen) {
 1597                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
 1598                         return 0;
 1599 
 1600                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
 1601                         return 0;
 1602                 /* we don't support compression yet */
 1603                 if (a[0] >= 64 || b[0] >= 64)
 1604                         return 0;
 1605 
 1606                 /* truncated case */
 1607                 if (a[0] == 0 && a - a0 == alen - 1)
 1608                         return 1;
 1609                 if (b[0] == 0 && b - b0 == blen - 1)
 1610                         return 1;
 1611                 if (a[0] == 0 || b[0] == 0)
 1612                         return 0;
 1613 
 1614                 if (a[0] != b[0])
 1615                         return 0;
 1616                 l = a[0];
 1617                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
 1618                         return 0;
 1619                 if (bcmp(a + 1, b + 1, l) != 0)
 1620                         return 0;
 1621 
 1622                 a += 1 + l;
 1623                 b += 1 + l;
 1624         }
 1625 
 1626         if (a - a0 == alen && b - b0 == blen)
 1627                 return 1;
 1628         else
 1629                 return 0;
 1630 }
 1631 
 1632 /*
 1633  * calculate the number of addresses to be returned in the node info reply.
 1634  */
 1635 static int
 1636 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
 1637     struct in6_addr *subj)
 1638 {
 1639         struct ifnet *ifp;
 1640         struct in6_ifaddr *ifa6;
 1641         struct ifaddr *ifa;
 1642         int addrs = 0, addrsofif, iffound = 0;
 1643         int niflags = ni6->ni_flags;
 1644 
 1645         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
 1646                 switch (ni6->ni_code) {
 1647                 case ICMP6_NI_SUBJ_IPV6:
 1648                         if (subj == NULL) /* must be impossible... */
 1649                                 return (0);
 1650                         break;
 1651                 default:
 1652                         /*
 1653                          * XXX: we only support IPv6 subject address for
 1654                          * this Qtype.
 1655                          */
 1656                         return (0);
 1657                 }
 1658         }
 1659 
 1660         IFNET_RLOCK();
 1661         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
 1662                 addrsofif = 0;
 1663                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
 1664                         if (ifa->ifa_addr->sa_family != AF_INET6)
 1665                                 continue;
 1666                         ifa6 = (struct in6_ifaddr *)ifa;
 1667 
 1668                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
 1669                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
 1670                                 iffound = 1;
 1671 
 1672                         /*
 1673                          * IPv4-mapped addresses can only be returned by a
 1674                          * Node Information proxy, since they represent
 1675                          * addresses of IPv4-only nodes, which perforce do
 1676                          * not implement this protocol.
 1677                          * [icmp-name-lookups-07, Section 5.4]
 1678                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
 1679                          * this function at this moment.
 1680                          */
 1681 
 1682                         /* What do we have to do about ::1? */
 1683                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
 1684                         case IPV6_ADDR_SCOPE_LINKLOCAL:
 1685                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
 1686                                         continue;
 1687                                 break;
 1688                         case IPV6_ADDR_SCOPE_SITELOCAL:
 1689                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
 1690                                         continue;
 1691                                 break;
 1692                         case IPV6_ADDR_SCOPE_GLOBAL:
 1693                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
 1694                                         continue;
 1695                                 break;
 1696                         default:
 1697                                 continue;
 1698                         }
 1699 
 1700                         /*
 1701                          * check if anycast is okay.
 1702                          * XXX: just experimental.  not in the spec.
 1703                          */
 1704                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
 1705                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
 1706                                 continue; /* we need only unicast addresses */
 1707                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
 1708                             (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
 1709                                 continue;
 1710                         }
 1711                         addrsofif++; /* count the address */
 1712                 }
 1713                 if (iffound) {
 1714                         *ifpp = ifp;
 1715                         IFNET_RUNLOCK();
 1716                         return (addrsofif);
 1717                 }
 1718 
 1719                 addrs += addrsofif;
 1720         }
 1721         IFNET_RUNLOCK();
 1722 
 1723         return (addrs);
 1724 }
 1725 
 1726 static int
 1727 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
 1728     struct ifnet *ifp0, int resid)
 1729 {
 1730         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
 1731         struct in6_ifaddr *ifa6;
 1732         struct ifaddr *ifa;
 1733         struct ifnet *ifp_dep = NULL;
 1734         int copied = 0, allow_deprecated = 0;
 1735         u_char *cp = (u_char *)(nni6 + 1);
 1736         int niflags = ni6->ni_flags;
 1737         u_int32_t ltime;
 1738 
 1739         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
 1740                 return (0);     /* needless to copy */
 1741 
 1742         IFNET_RLOCK();
 1743   again:
 1744 
 1745         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
 1746                 for (ifa = ifp->if_addrlist.tqh_first; ifa;
 1747                      ifa = ifa->ifa_list.tqe_next) {
 1748                         if (ifa->ifa_addr->sa_family != AF_INET6)
 1749                                 continue;
 1750                         ifa6 = (struct in6_ifaddr *)ifa;
 1751 
 1752                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
 1753                             allow_deprecated == 0) {
 1754                                 /*
 1755                                  * prefererred address should be put before
 1756                                  * deprecated addresses.
 1757                                  */
 1758 
 1759                                 /* record the interface for later search */
 1760                                 if (ifp_dep == NULL)
 1761                                         ifp_dep = ifp;
 1762 
 1763                                 continue;
 1764                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
 1765                             allow_deprecated != 0)
 1766                                 continue; /* we now collect deprecated addrs */
 1767 
 1768                         /* What do we have to do about ::1? */
 1769                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
 1770                         case IPV6_ADDR_SCOPE_LINKLOCAL:
 1771                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
 1772                                         continue;
 1773                                 break;
 1774                         case IPV6_ADDR_SCOPE_SITELOCAL:
 1775                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
 1776                                         continue;
 1777                                 break;
 1778                         case IPV6_ADDR_SCOPE_GLOBAL:
 1779                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
 1780                                         continue;
 1781                                 break;
 1782                         default:
 1783                                 continue;
 1784                         }
 1785 
 1786                         /*
 1787                          * check if anycast is okay.
 1788                          * XXX: just experimental.  not in the spec.
 1789                          */
 1790                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
 1791                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
 1792                                 continue;
 1793                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
 1794                             (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
 1795                                 continue;
 1796                         }
 1797 
 1798                         /* now we can copy the address */
 1799                         if (resid < sizeof(struct in6_addr) +
 1800                             sizeof(u_int32_t)) {
 1801                                 /*
 1802                                  * We give up much more copy.
 1803                                  * Set the truncate flag and return.
 1804                                  */
 1805                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
 1806                                 IFNET_RUNLOCK();
 1807                                 return (copied);
 1808                         }
 1809 
 1810                         /*
 1811                          * Set the TTL of the address.
 1812                          * The TTL value should be one of the following
 1813                          * according to the specification:
 1814                          *
 1815                          * 1. The remaining lifetime of a DHCP lease on the
 1816                          *    address, or
 1817                          * 2. The remaining Valid Lifetime of a prefix from
 1818                          *    which the address was derived through Stateless
 1819                          *    Autoconfiguration.
 1820                          *
 1821                          * Note that we currently do not support stateful
 1822                          * address configuration by DHCPv6, so the former
 1823                          * case can't happen.
 1824                          */
 1825                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
 1826                                 ltime = ND6_INFINITE_LIFETIME;
 1827                         else {
 1828                                 if (ifa6->ia6_lifetime.ia6t_expire >
 1829                                     time_second)
 1830                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
 1831                                 else
 1832                                         ltime = 0;
 1833                         }
 1834 
 1835                         bcopy(&ltime, cp, sizeof(u_int32_t));
 1836                         cp += sizeof(u_int32_t);
 1837 
 1838                         /* copy the address itself */
 1839                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
 1840                             sizeof(struct in6_addr));
 1841                         in6_clearscope((struct in6_addr *)cp); /* XXX */
 1842                         cp += sizeof(struct in6_addr);
 1843 
 1844                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
 1845                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
 1846                 }
 1847                 if (ifp0)       /* we need search only on the specified IF */
 1848                         break;
 1849         }
 1850 
 1851         if (allow_deprecated == 0 && ifp_dep != NULL) {
 1852                 ifp = ifp_dep;
 1853                 allow_deprecated = 1;
 1854 
 1855                 goto again;
 1856         }
 1857 
 1858         IFNET_RUNLOCK();
 1859 
 1860         return (copied);
 1861 }
 1862 
 1863 /*
 1864  * XXX almost dup'ed code with rip6_input.
 1865  */
 1866 static int
 1867 icmp6_rip6_input(struct mbuf **mp, int off)
 1868 {
 1869         struct mbuf *m = *mp;
 1870         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 1871         struct inpcb *in6p;
 1872         struct inpcb *last = NULL;
 1873         struct sockaddr_in6 fromsa;
 1874         struct icmp6_hdr *icmp6;
 1875         struct mbuf *opts = NULL;
 1876 
 1877 #ifndef PULLDOWN_TEST
 1878         /* this is assumed to be safe. */
 1879         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 1880 #else
 1881         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 1882         if (icmp6 == NULL) {
 1883                 /* m is already reclaimed */
 1884                 return (IPPROTO_DONE);
 1885         }
 1886 #endif
 1887 
 1888         /*
 1889          * XXX: the address may have embedded scope zone ID, which should be
 1890          * hidden from applications.
 1891          */
 1892         bzero(&fromsa, sizeof(fromsa));
 1893         fromsa.sin6_family = AF_INET6;
 1894         fromsa.sin6_len = sizeof(struct sockaddr_in6);
 1895         fromsa.sin6_addr = ip6->ip6_src;
 1896         if (sa6_recoverscope(&fromsa)) {
 1897                 m_freem(m);
 1898                 return (IPPROTO_DONE);
 1899         }
 1900 
 1901         INP_INFO_RLOCK(&ripcbinfo);
 1902         LIST_FOREACH(in6p, &ripcb, inp_list) {
 1903                 if ((in6p->inp_vflag & INP_IPV6) == 0)
 1904                         continue;
 1905                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
 1906                         continue;
 1907                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
 1908                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
 1909                         continue;
 1910                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
 1911                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
 1912                         continue;
 1913                 INP_RLOCK(in6p);
 1914                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
 1915                     in6p->in6p_icmp6filt)) {
 1916                         INP_RUNLOCK(in6p);
 1917                         continue;
 1918                 }
 1919                 if (last) {
 1920                         struct  mbuf *n = NULL;
 1921 
 1922                         /*
 1923                          * Recent network drivers tend to allocate a single
 1924                          * mbuf cluster, rather than to make a couple of
 1925                          * mbufs without clusters.  Also, since the IPv6 code
 1926                          * path tries to avoid m_pullup(), it is highly
 1927                          * probable that we still have an mbuf cluster here
 1928                          * even though the necessary length can be stored in an
 1929                          * mbuf's internal buffer.
 1930                          * Meanwhile, the default size of the receive socket
 1931                          * buffer for raw sockets is not so large.  This means
 1932                          * the possibility of packet loss is relatively higher
 1933                          * than before.  To avoid this scenario, we copy the
 1934                          * received data to a separate mbuf that does not use
 1935                          * a cluster, if possible.
 1936                          * XXX: it is better to copy the data after stripping
 1937                          * intermediate headers.
 1938                          */
 1939                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
 1940                             m->m_len <= MHLEN) {
 1941                                 MGET(n, M_DONTWAIT, m->m_type);
 1942                                 if (n != NULL) {
 1943                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
 1944                                                 bcopy(m->m_data, n->m_data,
 1945                                                       m->m_len);
 1946                                                 n->m_len = m->m_len;
 1947                                         } else {
 1948                                                 m_free(n);
 1949                                                 n = NULL;
 1950                                         }
 1951                                 }
 1952                         }
 1953                         if (n != NULL ||
 1954                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
 1955                                 if (last->inp_flags & INP_CONTROLOPTS)
 1956                                         ip6_savecontrol(last, n, &opts);
 1957                                 /* strip intermediate headers */
 1958                                 m_adj(n, off);
 1959                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
 1960                                 if (sbappendaddr_locked(
 1961                                     &last->inp_socket->so_rcv,
 1962                                     (struct sockaddr *)&fromsa, n, opts)
 1963                                     == 0) {
 1964                                         /* should notify about lost packet */
 1965                                         m_freem(n);
 1966                                         if (opts) {
 1967                                                 m_freem(opts);
 1968                                         }
 1969                                         SOCKBUF_UNLOCK(
 1970                                             &last->inp_socket->so_rcv);
 1971                                 } else
 1972                                         sorwakeup_locked(last->inp_socket);
 1973                                 opts = NULL;
 1974                         }
 1975                         INP_RUNLOCK(last);
 1976                 }
 1977                 last = in6p;
 1978         }
 1979         INP_INFO_RUNLOCK(&ripcbinfo);
 1980         if (last) {
 1981                 if (last->inp_flags & INP_CONTROLOPTS)
 1982                         ip6_savecontrol(last, m, &opts);
 1983                 /* strip intermediate headers */
 1984                 m_adj(m, off);
 1985 
 1986                 /* avoid using mbuf clusters if possible (see above) */
 1987                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
 1988                     m->m_len <= MHLEN) {
 1989                         struct mbuf *n;
 1990 
 1991                         MGET(n, M_DONTWAIT, m->m_type);
 1992                         if (n != NULL) {
 1993                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
 1994                                         bcopy(m->m_data, n->m_data, m->m_len);
 1995                                         n->m_len = m->m_len;
 1996 
 1997                                         m_freem(m);
 1998                                         m = n;
 1999                                 } else {
 2000                                         m_freem(n);
 2001                                         n = NULL;
 2002                                 }
 2003                         }
 2004                 }
 2005                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
 2006                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
 2007                     (struct sockaddr *)&fromsa, m, opts) == 0) {
 2008                         m_freem(m);
 2009                         if (opts)
 2010                                 m_freem(opts);
 2011                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
 2012                 } else
 2013                         sorwakeup_locked(last->inp_socket);
 2014                 INP_RUNLOCK(last);
 2015         } else {
 2016                 m_freem(m);
 2017                 ip6stat.ip6s_delivered--;
 2018         }
 2019         return IPPROTO_DONE;
 2020 }
 2021 
 2022 /*
 2023  * Reflect the ip6 packet back to the source.
 2024  * OFF points to the icmp6 header, counted from the top of the mbuf.
 2025  */
 2026 void
 2027 icmp6_reflect(struct mbuf *m, size_t off)
 2028 {
 2029         struct ip6_hdr *ip6;
 2030         struct icmp6_hdr *icmp6;
 2031         struct in6_ifaddr *ia;
 2032         int plen;
 2033         int type, code;
 2034         struct ifnet *outif = NULL;
 2035         struct in6_addr origdst, src, *srcp = NULL;
 2036 
 2037         /* too short to reflect */
 2038         if (off < sizeof(struct ip6_hdr)) {
 2039                 nd6log((LOG_DEBUG,
 2040                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
 2041                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
 2042                     __FILE__, __LINE__));
 2043                 goto bad;
 2044         }
 2045 
 2046         /*
 2047          * If there are extra headers between IPv6 and ICMPv6, strip
 2048          * off that header first.
 2049          */
 2050 #ifdef DIAGNOSTIC
 2051         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
 2052                 panic("assumption failed in icmp6_reflect");
 2053 #endif
 2054         if (off > sizeof(struct ip6_hdr)) {
 2055                 size_t l;
 2056                 struct ip6_hdr nip6;
 2057 
 2058                 l = off - sizeof(struct ip6_hdr);
 2059                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
 2060                 m_adj(m, l);
 2061                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 2062                 if (m->m_len < l) {
 2063                         if ((m = m_pullup(m, l)) == NULL)
 2064                                 return;
 2065                 }
 2066                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
 2067         } else /* off == sizeof(struct ip6_hdr) */ {
 2068                 size_t l;
 2069                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 2070                 if (m->m_len < l) {
 2071                         if ((m = m_pullup(m, l)) == NULL)
 2072                                 return;
 2073                 }
 2074         }
 2075         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
 2076         ip6 = mtod(m, struct ip6_hdr *);
 2077         ip6->ip6_nxt = IPPROTO_ICMPV6;
 2078         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
 2079         type = icmp6->icmp6_type; /* keep type for statistics */
 2080         code = icmp6->icmp6_code; /* ditto. */
 2081 
 2082         origdst = ip6->ip6_dst;
 2083         /*
 2084          * ip6_input() drops a packet if its src is multicast.
 2085          * So, the src is never multicast.
 2086          */
 2087         ip6->ip6_dst = ip6->ip6_src;
 2088 
 2089         /*
 2090          * If the incoming packet was addressed directly to us (i.e. unicast),
 2091          * use dst as the src for the reply.
 2092          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
 2093          * (for example) when we encounter an error while forwarding procedure
 2094          * destined to a duplicated address of ours.
 2095          * Note that ip6_getdstifaddr() may fail if we are in an error handling
 2096          * procedure of an outgoing packet of our own, in which case we need
 2097          * to search in the ifaddr list.
 2098          */
 2099         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
 2100                 if ((ia = ip6_getdstifaddr(m))) {
 2101                         if (!(ia->ia6_flags &
 2102                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
 2103                                 srcp = &ia->ia_addr.sin6_addr;
 2104                 } else {
 2105                         struct sockaddr_in6 d;
 2106 
 2107                         bzero(&d, sizeof(d));
 2108                         d.sin6_family = AF_INET6;
 2109                         d.sin6_len = sizeof(d);
 2110                         d.sin6_addr = origdst;
 2111                         ia = (struct in6_ifaddr *)
 2112                             ifa_ifwithaddr((struct sockaddr *)&d);
 2113                         if (ia &&
 2114                             !(ia->ia6_flags &
 2115                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
 2116                                 srcp = &ia->ia_addr.sin6_addr;
 2117                         }
 2118                 }
 2119         }
 2120 
 2121         if (srcp == NULL) {
 2122                 int e;
 2123                 struct sockaddr_in6 sin6;
 2124                 struct route_in6 ro;
 2125 
 2126                 /*
 2127                  * This case matches to multicasts, our anycast, or unicasts
 2128                  * that we do not own.  Select a source address based on the
 2129                  * source address of the erroneous packet.
 2130                  */
 2131                 bzero(&sin6, sizeof(sin6));
 2132                 sin6.sin6_family = AF_INET6;
 2133                 sin6.sin6_len = sizeof(sin6);
 2134                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
 2135 
 2136                 bzero(&ro, sizeof(ro));
 2137                 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
 2138                 if (ro.ro_rt)
 2139                         RTFREE(ro.ro_rt); /* XXX: we could use this */
 2140                 if (e) {
 2141                         char ip6buf[INET6_ADDRSTRLEN];
 2142                         nd6log((LOG_DEBUG,
 2143                             "icmp6_reflect: source can't be determined: "
 2144                             "dst=%s, error=%d\n",
 2145                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
 2146                         goto bad;
 2147                 }
 2148                 srcp = &src;
 2149         }
 2150 
 2151         ip6->ip6_src = *srcp;
 2152         ip6->ip6_flow = 0;
 2153         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 2154         ip6->ip6_vfc |= IPV6_VERSION;
 2155         ip6->ip6_nxt = IPPROTO_ICMPV6;
 2156         if (outif)
 2157                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
 2158         else if (m->m_pkthdr.rcvif) {
 2159                 /* XXX: This may not be the outgoing interface */
 2160                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
 2161         } else
 2162                 ip6->ip6_hlim = ip6_defhlim;
 2163 
 2164         icmp6->icmp6_cksum = 0;
 2165         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
 2166             sizeof(struct ip6_hdr), plen);
 2167 
 2168         /*
 2169          * XXX option handling
 2170          */
 2171 
 2172         m->m_flags &= ~(M_BCAST|M_MCAST);
 2173 
 2174         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
 2175         if (outif)
 2176                 icmp6_ifoutstat_inc(outif, type, code);
 2177 
 2178         return;
 2179 
 2180  bad:
 2181         m_freem(m);
 2182         return;
 2183 }
 2184 
 2185 void
 2186 icmp6_fasttimo(void)
 2187 {
 2188 
 2189         return;
 2190 }
 2191 
 2192 static const char *
 2193 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
 2194     struct in6_addr *tgt6)
 2195 {
 2196         static char buf[1024];
 2197         char ip6bufs[INET6_ADDRSTRLEN];
 2198         char ip6bufd[INET6_ADDRSTRLEN];
 2199         char ip6buft[INET6_ADDRSTRLEN];
 2200         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
 2201             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
 2202             ip6_sprintf(ip6buft, tgt6));
 2203         return buf;
 2204 }
 2205 
 2206 void
 2207 icmp6_redirect_input(struct mbuf *m, int off)
 2208 {
 2209         struct ifnet *ifp;
 2210         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 2211         struct nd_redirect *nd_rd;
 2212         int icmp6len = ntohs(ip6->ip6_plen);
 2213         char *lladdr = NULL;
 2214         int lladdrlen = 0;
 2215         struct rtentry *rt = NULL;
 2216         int is_router;
 2217         int is_onlink;
 2218         struct in6_addr src6 = ip6->ip6_src;
 2219         struct in6_addr redtgt6;
 2220         struct in6_addr reddst6;
 2221         union nd_opts ndopts;
 2222         char ip6buf[INET6_ADDRSTRLEN];
 2223 
 2224         if (!m)
 2225                 return;
 2226 
 2227         ifp = m->m_pkthdr.rcvif;
 2228 
 2229         if (!ifp)
 2230                 return;
 2231 
 2232         /* XXX if we are router, we don't update route by icmp6 redirect */
 2233         if (ip6_forwarding)
 2234                 goto freeit;
 2235         if (!icmp6_rediraccept)
 2236                 goto freeit;
 2237 
 2238 #ifndef PULLDOWN_TEST
 2239         IP6_EXTHDR_CHECK(m, off, icmp6len,);
 2240         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
 2241 #else
 2242         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
 2243         if (nd_rd == NULL) {
 2244                 icmp6stat.icp6s_tooshort++;
 2245                 return;
 2246         }
 2247 #endif
 2248         redtgt6 = nd_rd->nd_rd_target;
 2249         reddst6 = nd_rd->nd_rd_dst;
 2250 
 2251         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
 2252             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
 2253                 goto freeit;
 2254         }
 2255 
 2256         /* validation */
 2257         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
 2258                 nd6log((LOG_ERR,
 2259                     "ICMP6 redirect sent from %s rejected; "
 2260                     "must be from linklocal\n",
 2261                     ip6_sprintf(ip6buf, &src6)));
 2262                 goto bad;
 2263         }
 2264         if (ip6->ip6_hlim != 255) {
 2265                 nd6log((LOG_ERR,
 2266                     "ICMP6 redirect sent from %s rejected; "
 2267                     "hlim=%d (must be 255)\n",
 2268                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
 2269                 goto bad;
 2270         }
 2271     {
 2272         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
 2273         struct sockaddr_in6 sin6;
 2274         struct in6_addr *gw6;
 2275 
 2276         bzero(&sin6, sizeof(sin6));
 2277         sin6.sin6_family = AF_INET6;
 2278         sin6.sin6_len = sizeof(struct sockaddr_in6);
 2279         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
 2280         rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
 2281         if (rt) {
 2282                 if (rt->rt_gateway == NULL ||
 2283                     rt->rt_gateway->sa_family != AF_INET6) {
 2284                         nd6log((LOG_ERR,
 2285                             "ICMP6 redirect rejected; no route "
 2286                             "with inet6 gateway found for redirect dst: %s\n",
 2287                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2288                         RTFREE_LOCKED(rt);
 2289                         goto bad;
 2290                 }
 2291 
 2292                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
 2293                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
 2294                         nd6log((LOG_ERR,
 2295                             "ICMP6 redirect rejected; "
 2296                             "not equal to gw-for-src=%s (must be same): "
 2297                             "%s\n",
 2298                             ip6_sprintf(ip6buf, gw6),
 2299                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2300                         RTFREE_LOCKED(rt);
 2301                         goto bad;
 2302                 }
 2303         } else {
 2304                 nd6log((LOG_ERR,
 2305                     "ICMP6 redirect rejected; "
 2306                     "no route found for redirect dst: %s\n",
 2307                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2308                 goto bad;
 2309         }
 2310         RTFREE_LOCKED(rt);
 2311         rt = NULL;
 2312     }
 2313         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
 2314                 nd6log((LOG_ERR,
 2315                     "ICMP6 redirect rejected; "
 2316                     "redirect dst must be unicast: %s\n",
 2317                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2318                 goto bad;
 2319         }
 2320 
 2321         is_router = is_onlink = 0;
 2322         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
 2323                 is_router = 1;  /* router case */
 2324         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
 2325                 is_onlink = 1;  /* on-link destination case */
 2326         if (!is_router && !is_onlink) {
 2327                 nd6log((LOG_ERR,
 2328                     "ICMP6 redirect rejected; "
 2329                     "neither router case nor onlink case: %s\n",
 2330                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2331                 goto bad;
 2332         }
 2333         /* validation passed */
 2334 
 2335         icmp6len -= sizeof(*nd_rd);
 2336         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
 2337         if (nd6_options(&ndopts) < 0) {
 2338                 nd6log((LOG_INFO, "icmp6_redirect_input: "
 2339                     "invalid ND option, rejected: %s\n",
 2340                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2341                 /* nd6_options have incremented stats */
 2342                 goto freeit;
 2343         }
 2344 
 2345         if (ndopts.nd_opts_tgt_lladdr) {
 2346                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
 2347                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
 2348         }
 2349 
 2350         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
 2351                 nd6log((LOG_INFO,
 2352                     "icmp6_redirect_input: lladdrlen mismatch for %s "
 2353                     "(if %d, icmp6 packet %d): %s\n",
 2354                     ip6_sprintf(ip6buf, &redtgt6),
 2355                     ifp->if_addrlen, lladdrlen - 2,
 2356                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2357                 goto bad;
 2358         }
 2359 
 2360         /* RFC 2461 8.3 */
 2361         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
 2362             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
 2363 
 2364         if (!is_onlink) {       /* better router case.  perform rtredirect. */
 2365                 /* perform rtredirect */
 2366                 struct sockaddr_in6 sdst;
 2367                 struct sockaddr_in6 sgw;
 2368                 struct sockaddr_in6 ssrc;
 2369 
 2370                 bzero(&sdst, sizeof(sdst));
 2371                 bzero(&sgw, sizeof(sgw));
 2372                 bzero(&ssrc, sizeof(ssrc));
 2373                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
 2374                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
 2375                         sizeof(struct sockaddr_in6);
 2376                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
 2377                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
 2378                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
 2379                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
 2380                     (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
 2381                     (struct sockaddr *)&ssrc);
 2382         }
 2383         /* finally update cached route in each socket via pfctlinput */
 2384     {
 2385         struct sockaddr_in6 sdst;
 2386 
 2387         bzero(&sdst, sizeof(sdst));
 2388         sdst.sin6_family = AF_INET6;
 2389         sdst.sin6_len = sizeof(struct sockaddr_in6);
 2390         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
 2391         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
 2392 #ifdef IPSEC
 2393         key_sa_routechange((struct sockaddr *)&sdst);
 2394 #endif /* IPSEC */
 2395     }
 2396 
 2397  freeit:
 2398         m_freem(m);
 2399         return;
 2400 
 2401  bad:
 2402         icmp6stat.icp6s_badredirect++;
 2403         m_freem(m);
 2404 }
 2405 
 2406 void
 2407 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
 2408 {
 2409         struct ifnet *ifp;      /* my outgoing interface */
 2410         struct in6_addr *ifp_ll6;
 2411         struct in6_addr *router_ll6;
 2412         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
 2413         struct mbuf *m = NULL;  /* newly allocated one */
 2414         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
 2415         struct nd_redirect *nd_rd;
 2416         size_t maxlen;
 2417         u_char *p;
 2418         struct ifnet *outif = NULL;
 2419         struct sockaddr_in6 src_sa;
 2420 
 2421         icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
 2422 
 2423         /* if we are not router, we don't send icmp6 redirect */
 2424         if (!ip6_forwarding)
 2425                 goto fail;
 2426 
 2427         /* sanity check */
 2428         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
 2429                 goto fail;
 2430 
 2431         /*
 2432          * Address check:
 2433          *  the source address must identify a neighbor, and
 2434          *  the destination address must not be a multicast address
 2435          *  [RFC 2461, sec 8.2]
 2436          */
 2437         sip6 = mtod(m0, struct ip6_hdr *);
 2438         bzero(&src_sa, sizeof(src_sa));
 2439         src_sa.sin6_family = AF_INET6;
 2440         src_sa.sin6_len = sizeof(src_sa);
 2441         src_sa.sin6_addr = sip6->ip6_src;
 2442         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
 2443                 goto fail;
 2444         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
 2445                 goto fail;      /* what should we do here? */
 2446 
 2447         /* rate limit */
 2448         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
 2449                 goto fail;
 2450 
 2451         /*
 2452          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
 2453          * we almost always ask for an mbuf cluster for simplicity.
 2454          * (MHLEN < IPV6_MMTU is almost always true)
 2455          */
 2456 #if IPV6_MMTU >= MCLBYTES
 2457 # error assumption failed about IPV6_MMTU and MCLBYTES
 2458 #endif
 2459         MGETHDR(m, M_DONTWAIT, MT_HEADER);
 2460         if (m && IPV6_MMTU >= MHLEN)
 2461                 MCLGET(m, M_DONTWAIT);
 2462         if (!m)
 2463                 goto fail;
 2464         m->m_pkthdr.rcvif = NULL;
 2465         m->m_len = 0;
 2466         maxlen = M_TRAILINGSPACE(m);
 2467         maxlen = min(IPV6_MMTU, maxlen);
 2468         /* just for safety */
 2469         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
 2470             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
 2471                 goto fail;
 2472         }
 2473 
 2474         {
 2475                 /* get ip6 linklocal address for ifp(my outgoing interface). */
 2476                 struct in6_ifaddr *ia;
 2477                 if ((ia = in6ifa_ifpforlinklocal(ifp,
 2478                                                  IN6_IFF_NOTREADY|
 2479                                                  IN6_IFF_ANYCAST)) == NULL)
 2480                         goto fail;
 2481                 ifp_ll6 = &ia->ia_addr.sin6_addr;
 2482         }
 2483 
 2484         /* get ip6 linklocal address for the router. */
 2485         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
 2486                 struct sockaddr_in6 *sin6;
 2487                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
 2488                 router_ll6 = &sin6->sin6_addr;
 2489                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
 2490                         router_ll6 = (struct in6_addr *)NULL;
 2491         } else
 2492                 router_ll6 = (struct in6_addr *)NULL;
 2493 
 2494         /* ip6 */
 2495         ip6 = mtod(m, struct ip6_hdr *);
 2496         ip6->ip6_flow = 0;
 2497         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 2498         ip6->ip6_vfc |= IPV6_VERSION;
 2499         /* ip6->ip6_plen will be set later */
 2500         ip6->ip6_nxt = IPPROTO_ICMPV6;
 2501         ip6->ip6_hlim = 255;
 2502         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
 2503         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
 2504         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
 2505 
 2506         /* ND Redirect */
 2507         nd_rd = (struct nd_redirect *)(ip6 + 1);
 2508         nd_rd->nd_rd_type = ND_REDIRECT;
 2509         nd_rd->nd_rd_code = 0;
 2510         nd_rd->nd_rd_reserved = 0;
 2511         if (rt->rt_flags & RTF_GATEWAY) {
 2512                 /*
 2513                  * nd_rd->nd_rd_target must be a link-local address in
 2514                  * better router cases.
 2515                  */
 2516                 if (!router_ll6)
 2517                         goto fail;
 2518                 bcopy(router_ll6, &nd_rd->nd_rd_target,
 2519                     sizeof(nd_rd->nd_rd_target));
 2520                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
 2521                     sizeof(nd_rd->nd_rd_dst));
 2522         } else {
 2523                 /* make sure redtgt == reddst */
 2524                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
 2525                     sizeof(nd_rd->nd_rd_target));
 2526                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
 2527                     sizeof(nd_rd->nd_rd_dst));
 2528         }
 2529 
 2530         p = (u_char *)(nd_rd + 1);
 2531 
 2532         if (!router_ll6)
 2533                 goto nolladdropt;
 2534 
 2535         {
 2536                 /* target lladdr option */
 2537                 struct rtentry *rt_router = NULL;
 2538                 int len;
 2539                 struct sockaddr_dl *sdl;
 2540                 struct nd_opt_hdr *nd_opt;
 2541                 char *lladdr;
 2542 
 2543                 rt_router = nd6_lookup(router_ll6, 0, ifp);
 2544                 if (!rt_router)
 2545                         goto nolladdropt;
 2546                 len = sizeof(*nd_opt) + ifp->if_addrlen;
 2547                 len = (len + 7) & ~7;   /* round by 8 */
 2548                 /* safety check */
 2549                 if (len + (p - (u_char *)ip6) > maxlen)
 2550                         goto nolladdropt;
 2551                 if (!(rt_router->rt_flags & RTF_GATEWAY) &&
 2552                     (rt_router->rt_flags & RTF_LLINFO) &&
 2553                     (rt_router->rt_gateway->sa_family == AF_LINK) &&
 2554                     (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
 2555                     sdl->sdl_alen) {
 2556                         nd_opt = (struct nd_opt_hdr *)p;
 2557                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
 2558                         nd_opt->nd_opt_len = len >> 3;
 2559                         lladdr = (char *)(nd_opt + 1);
 2560                         bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
 2561                         p += len;
 2562                 }
 2563         }
 2564 nolladdropt:;
 2565 
 2566         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
 2567 
 2568         /* just to be safe */
 2569 #ifdef M_DECRYPTED      /*not openbsd*/
 2570         if (m0->m_flags & M_DECRYPTED)
 2571                 goto noredhdropt;
 2572 #endif
 2573         if (p - (u_char *)ip6 > maxlen)
 2574                 goto noredhdropt;
 2575 
 2576         {
 2577                 /* redirected header option */
 2578                 int len;
 2579                 struct nd_opt_rd_hdr *nd_opt_rh;
 2580 
 2581                 /*
 2582                  * compute the maximum size for icmp6 redirect header option.
 2583                  * XXX room for auth header?
 2584                  */
 2585                 len = maxlen - (p - (u_char *)ip6);
 2586                 len &= ~7;
 2587 
 2588                 /* This is just for simplicity. */
 2589                 if (m0->m_pkthdr.len != m0->m_len) {
 2590                         if (m0->m_next) {
 2591                                 m_freem(m0->m_next);
 2592                                 m0->m_next = NULL;
 2593                         }
 2594                         m0->m_pkthdr.len = m0->m_len;
 2595                 }
 2596 
 2597                 /*
 2598                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
 2599                  * about padding/truncate rule for the original IP packet.
 2600                  * From the discussion on IPv6imp in Feb 1999,
 2601                  * the consensus was:
 2602                  * - "attach as much as possible" is the goal
 2603                  * - pad if not aligned (original size can be guessed by
 2604                  *   original ip6 header)
 2605                  * Following code adds the padding if it is simple enough,
 2606                  * and truncates if not.
 2607                  */
 2608                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
 2609                         panic("assumption failed in %s:%d", __FILE__,
 2610                             __LINE__);
 2611 
 2612                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
 2613                         /* not enough room, truncate */
 2614                         m0->m_pkthdr.len = m0->m_len = len -
 2615                             sizeof(*nd_opt_rh);
 2616                 } else {
 2617                         /* enough room, pad or truncate */
 2618                         size_t extra;
 2619 
 2620                         extra = m0->m_pkthdr.len % 8;
 2621                         if (extra) {
 2622                                 /* pad if easy enough, truncate if not */
 2623                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
 2624                                         /* pad */
 2625                                         m0->m_len += (8 - extra);
 2626                                         m0->m_pkthdr.len += (8 - extra);
 2627                                 } else {
 2628                                         /* truncate */
 2629                                         m0->m_pkthdr.len -= extra;
 2630                                         m0->m_len -= extra;
 2631                                 }
 2632                         }
 2633                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
 2634                         m0->m_pkthdr.len = m0->m_len = len -
 2635                             sizeof(*nd_opt_rh);
 2636                 }
 2637 
 2638                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
 2639                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
 2640                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
 2641                 nd_opt_rh->nd_opt_rh_len = len >> 3;
 2642                 p += sizeof(*nd_opt_rh);
 2643                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
 2644 
 2645                 /* connect m0 to m */
 2646                 m_tag_delete_chain(m0, NULL);
 2647                 m0->m_flags &= ~M_PKTHDR;
 2648                 m->m_next = m0;
 2649                 m->m_pkthdr.len = m->m_len + m0->m_len;
 2650                 m0 = NULL;
 2651         }
 2652 noredhdropt:;
 2653         if (m0) {
 2654                 m_freem(m0);
 2655                 m0 = NULL;
 2656         }
 2657 
 2658         /* XXX: clear embedded link IDs in the inner header */
 2659         in6_clearscope(&sip6->ip6_src);
 2660         in6_clearscope(&sip6->ip6_dst);
 2661         in6_clearscope(&nd_rd->nd_rd_target);
 2662         in6_clearscope(&nd_rd->nd_rd_dst);
 2663 
 2664         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
 2665 
 2666         nd_rd->nd_rd_cksum = 0;
 2667         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
 2668             sizeof(*ip6), ntohs(ip6->ip6_plen));
 2669 
 2670         /* send the packet to outside... */
 2671         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
 2672         if (outif) {
 2673                 icmp6_ifstat_inc(outif, ifs6_out_msg);
 2674                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
 2675         }
 2676         icmp6stat.icp6s_outhist[ND_REDIRECT]++;
 2677 
 2678         return;
 2679 
 2680 fail:
 2681         if (m)
 2682                 m_freem(m);
 2683         if (m0)
 2684                 m_freem(m0);
 2685 }
 2686 
 2687 /*
 2688  * ICMPv6 socket option processing.
 2689  */
 2690 int
 2691 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
 2692 {
 2693         int error = 0;
 2694         int optlen;
 2695         struct inpcb *inp = sotoinpcb(so);
 2696         int level, op, optname;
 2697 
 2698         if (sopt) {
 2699                 level = sopt->sopt_level;
 2700                 op = sopt->sopt_dir;
 2701                 optname = sopt->sopt_name;
 2702                 optlen = sopt->sopt_valsize;
 2703         } else
 2704                 level = op = optname = optlen = 0;
 2705 
 2706         if (level != IPPROTO_ICMPV6) {
 2707                 return EINVAL;
 2708         }
 2709 
 2710         switch (op) {
 2711         case PRCO_SETOPT:
 2712                 switch (optname) {
 2713                 case ICMP6_FILTER:
 2714                     {
 2715                         struct icmp6_filter ic6f;
 2716 
 2717                         if (optlen != sizeof(ic6f)) {
 2718                                 error = EMSGSIZE;
 2719                                 break;
 2720                         }
 2721                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
 2722                         if (error == 0) {
 2723                                 INP_WLOCK(inp);
 2724                                 *inp->in6p_icmp6filt = ic6f;
 2725                                 INP_WUNLOCK(inp);
 2726                         }
 2727                         break;
 2728                     }
 2729 
 2730                 default:
 2731                         error = ENOPROTOOPT;
 2732                         break;
 2733                 }
 2734                 break;
 2735 
 2736         case PRCO_GETOPT:
 2737                 switch (optname) {
 2738                 case ICMP6_FILTER:
 2739                     {
 2740                         struct icmp6_filter ic6f;
 2741 
 2742                         INP_RLOCK(inp);
 2743                         ic6f = *inp->in6p_icmp6filt;
 2744                         INP_RUNLOCK(inp);
 2745                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
 2746                         break;
 2747                     }
 2748 
 2749                 default:
 2750                         error = ENOPROTOOPT;
 2751                         break;
 2752                 }
 2753                 break;
 2754         }
 2755 
 2756         return (error);
 2757 }
 2758 
 2759 /*
 2760  * Perform rate limit check.
 2761  * Returns 0 if it is okay to send the icmp6 packet.
 2762  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
 2763  * limitation.
 2764  *
 2765  * XXX per-destination/type check necessary?
 2766  *
 2767  * dst - not used at this moment
 2768  * type - not used at this moment
 2769  * code - not used at this moment
 2770  */
 2771 static int
 2772 icmp6_ratelimit(const struct in6_addr *dst, const int type,
 2773     const int code)
 2774 {
 2775         int ret;
 2776 
 2777         ret = 0;        /* okay to send */
 2778 
 2779         /* PPS limit */
 2780         if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
 2781             icmp6errppslim)) {
 2782                 /* The packet is subject to rate limit */
 2783                 ret++;
 2784         }
 2785 
 2786         return ret;
 2787 }

Cache object: 977fd497de22677ace8964a5b2e0de76


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