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: releng/10.4/sys/netinet6/icmp6.c 303459 2016-07-28 20:11:34Z sbruno $");
   65 
   66 #include "opt_inet.h"
   67 #include "opt_inet6.h"
   68 
   69 #include <sys/param.h>
   70 #include <sys/domain.h>
   71 #include <sys/jail.h>
   72 #include <sys/kernel.h>
   73 #include <sys/lock.h>
   74 #include <sys/malloc.h>
   75 #include <sys/mbuf.h>
   76 #include <sys/proc.h>
   77 #include <sys/protosw.h>
   78 #include <sys/signalvar.h>
   79 #include <sys/socket.h>
   80 #include <sys/socketvar.h>
   81 #include <sys/sx.h>
   82 #include <sys/syslog.h>
   83 #include <sys/systm.h>
   84 #include <sys/time.h>
   85 
   86 #include <net/if.h>
   87 #include <net/if_dl.h>
   88 #include <net/if_llatbl.h>
   89 #include <net/if_types.h>
   90 #include <net/route.h>
   91 #include <net/vnet.h>
   92 
   93 #include <netinet/in.h>
   94 #include <netinet/in_pcb.h>
   95 #include <netinet/in_var.h>
   96 #include <netinet/ip6.h>
   97 #include <netinet/icmp6.h>
   98 #include <netinet/tcp_var.h>
   99 
  100 #include <netinet6/in6_ifattach.h>
  101 #include <netinet6/in6_pcb.h>
  102 #include <netinet6/ip6protosw.h>
  103 #include <netinet6/ip6_var.h>
  104 #include <netinet6/scope6_var.h>
  105 #include <netinet6/mld6_var.h>
  106 #include <netinet6/nd6.h>
  107 #include <netinet6/send.h>
  108 
  109 extern struct domain inet6domain;
  110 
  111 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
  112 VNET_PCPUSTAT_SYSINIT(icmp6stat);
  113 
  114 #ifdef VIMAGE
  115 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
  116 #endif /* VIMAGE */
  117 
  118 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
  119 VNET_DECLARE(struct inpcbhead, ripcb);
  120 VNET_DECLARE(int, icmp6errppslim);
  121 static VNET_DEFINE(int, icmp6errpps_count) = 0;
  122 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
  123 VNET_DECLARE(int, icmp6_nodeinfo);
  124 
  125 #define V_ripcbinfo                     VNET(ripcbinfo)
  126 #define V_ripcb                         VNET(ripcb)
  127 #define V_icmp6errppslim                VNET(icmp6errppslim)
  128 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
  129 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
  130 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
  131 
  132 static void icmp6_errcount(int, int);
  133 static int icmp6_rip6_input(struct mbuf **, int);
  134 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
  135 static const char *icmp6_redirect_diag(struct in6_addr *,
  136         struct in6_addr *, struct in6_addr *);
  137 static struct mbuf *ni6_input(struct mbuf *, int);
  138 static struct mbuf *ni6_nametodns(const char *, int, int);
  139 static int ni6_dnsmatch(const char *, int, const char *, int);
  140 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
  141                           struct ifnet **, struct in6_addr *);
  142 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
  143                                 struct ifnet *, int);
  144 static int icmp6_notify_error(struct mbuf **, int, int, int);
  145 
  146 /*
  147  * Kernel module interface for updating icmp6stat.  The argument is an index
  148  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
  149  * general layout of icmp6stat into the caller, it doesn't encode its
  150  * location, so that future changes to add, for example, per-CPU stats
  151  * support won't cause binary compatibility problems for kernel modules.
  152  */
  153 void
  154 kmod_icmp6stat_inc(int statnum)
  155 {
  156 
  157         counter_u64_add(VNET(icmp6stat)[statnum], 1);
  158 }
  159 
  160 static void
  161 icmp6_errcount(int type, int code)
  162 {
  163         switch (type) {
  164         case ICMP6_DST_UNREACH:
  165                 switch (code) {
  166                 case ICMP6_DST_UNREACH_NOROUTE:
  167                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
  168                         return;
  169                 case ICMP6_DST_UNREACH_ADMIN:
  170                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
  171                         return;
  172                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
  173                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
  174                         return;
  175                 case ICMP6_DST_UNREACH_ADDR:
  176                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
  177                         return;
  178                 case ICMP6_DST_UNREACH_NOPORT:
  179                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
  180                         return;
  181                 }
  182                 break;
  183         case ICMP6_PACKET_TOO_BIG:
  184                 ICMP6STAT_INC(icp6s_opacket_too_big);
  185                 return;
  186         case ICMP6_TIME_EXCEEDED:
  187                 switch (code) {
  188                 case ICMP6_TIME_EXCEED_TRANSIT:
  189                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
  190                         return;
  191                 case ICMP6_TIME_EXCEED_REASSEMBLY:
  192                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
  193                         return;
  194                 }
  195                 break;
  196         case ICMP6_PARAM_PROB:
  197                 switch (code) {
  198                 case ICMP6_PARAMPROB_HEADER:
  199                         ICMP6STAT_INC(icp6s_oparamprob_header);
  200                         return;
  201                 case ICMP6_PARAMPROB_NEXTHEADER:
  202                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
  203                         return;
  204                 case ICMP6_PARAMPROB_OPTION:
  205                         ICMP6STAT_INC(icp6s_oparamprob_option);
  206                         return;
  207                 }
  208                 break;
  209         case ND_REDIRECT:
  210                 ICMP6STAT_INC(icp6s_oredirect);
  211                 return;
  212         }
  213         ICMP6STAT_INC(icp6s_ounknown);
  214 }
  215 
  216 /*
  217  * A wrapper function for icmp6_error() necessary when the erroneous packet
  218  * may not contain enough scope zone information.
  219  */
  220 void
  221 icmp6_error2(struct mbuf *m, int type, int code, int param,
  222     struct ifnet *ifp)
  223 {
  224         struct ip6_hdr *ip6;
  225 
  226         if (ifp == NULL)
  227                 return;
  228 
  229 #ifndef PULLDOWN_TEST
  230         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
  231 #else
  232         if (m->m_len < sizeof(struct ip6_hdr)) {
  233                 m = m_pullup(m, sizeof(struct ip6_hdr));
  234                 if (m == NULL)
  235                         return;
  236         }
  237 #endif
  238 
  239         ip6 = mtod(m, struct ip6_hdr *);
  240 
  241         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
  242                 return;
  243         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
  244                 return;
  245 
  246         icmp6_error(m, type, code, param);
  247 }
  248 
  249 /*
  250  * Generate an error packet of type error in response to bad IP6 packet.
  251  */
  252 void
  253 icmp6_error(struct mbuf *m, int type, int code, int param)
  254 {
  255         struct ip6_hdr *oip6, *nip6;
  256         struct icmp6_hdr *icmp6;
  257         u_int preplen;
  258         int off;
  259         int nxt;
  260 
  261         ICMP6STAT_INC(icp6s_error);
  262 
  263         /* count per-type-code statistics */
  264         icmp6_errcount(type, code);
  265 
  266 #ifdef M_DECRYPTED      /*not openbsd*/
  267         if (m->m_flags & M_DECRYPTED) {
  268                 ICMP6STAT_INC(icp6s_canterror);
  269                 goto freeit;
  270         }
  271 #endif
  272 
  273 #ifndef PULLDOWN_TEST
  274         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
  275 #else
  276         if (m->m_len < sizeof(struct ip6_hdr)) {
  277                 m = m_pullup(m, sizeof(struct ip6_hdr));
  278                 if (m == NULL)
  279                         return;
  280         }
  281 #endif
  282         oip6 = mtod(m, struct ip6_hdr *);
  283 
  284         /*
  285          * If the destination address of the erroneous packet is a multicast
  286          * address, or the packet was sent using link-layer multicast,
  287          * we should basically suppress sending an error (RFC 2463, Section
  288          * 2.4).
  289          * We have two exceptions (the item e.2 in that section):
  290          * - the Packet Too Big message can be sent for path MTU discovery.
  291          * - the Parameter Problem Message that can be allowed an icmp6 error
  292          *   in the option type field.  This check has been done in
  293          *   ip6_unknown_opt(), so we can just check the type and code.
  294          */
  295         if ((m->m_flags & (M_BCAST|M_MCAST) ||
  296              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
  297             (type != ICMP6_PACKET_TOO_BIG &&
  298              (type != ICMP6_PARAM_PROB ||
  299               code != ICMP6_PARAMPROB_OPTION)))
  300                 goto freeit;
  301 
  302         /*
  303          * RFC 2463, 2.4 (e.5): source address check.
  304          * XXX: the case of anycast source?
  305          */
  306         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
  307             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
  308                 goto freeit;
  309 
  310         /*
  311          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
  312          * don't do it.
  313          */
  314         nxt = -1;
  315         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
  316         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
  317                 struct icmp6_hdr *icp;
  318 
  319 #ifndef PULLDOWN_TEST
  320                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
  321                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
  322 #else
  323                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
  324                         sizeof(*icp));
  325                 if (icp == NULL) {
  326                         ICMP6STAT_INC(icp6s_tooshort);
  327                         return;
  328                 }
  329 #endif
  330                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
  331                     icp->icmp6_type == ND_REDIRECT) {
  332                         /*
  333                          * ICMPv6 error
  334                          * Special case: for redirect (which is
  335                          * informational) we must not send icmp6 error.
  336                          */
  337                         ICMP6STAT_INC(icp6s_canterror);
  338                         goto freeit;
  339                 } else {
  340                         /* ICMPv6 informational - send the error */
  341                 }
  342         } else {
  343                 /* non-ICMPv6 - send the error */
  344         }
  345 
  346         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
  347 
  348         /* Finally, do rate limitation check. */
  349         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
  350                 ICMP6STAT_INC(icp6s_toofreq);
  351                 goto freeit;
  352         }
  353 
  354         /*
  355          * OK, ICMP6 can be generated.
  356          */
  357 
  358         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
  359                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
  360 
  361         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
  362         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
  363         if (m == NULL) {
  364                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
  365                 return;
  366         }
  367 
  368         nip6 = mtod(m, struct ip6_hdr *);
  369         nip6->ip6_src  = oip6->ip6_src;
  370         nip6->ip6_dst  = oip6->ip6_dst;
  371 
  372         in6_clearscope(&oip6->ip6_src);
  373         in6_clearscope(&oip6->ip6_dst);
  374 
  375         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
  376         icmp6->icmp6_type = type;
  377         icmp6->icmp6_code = code;
  378         icmp6->icmp6_pptr = htonl((u_int32_t)param);
  379 
  380         /*
  381          * icmp6_reflect() is designed to be in the input path.
  382          * icmp6_error() can be called from both input and output path,
  383          * and if we are in output path rcvif could contain bogus value.
  384          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
  385          * information in ip header (nip6).
  386          */
  387         m->m_pkthdr.rcvif = NULL;
  388 
  389         ICMP6STAT_INC(icp6s_outhist[type]);
  390         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
  391 
  392         return;
  393 
  394   freeit:
  395         /*
  396          * If we can't tell whether or not we can generate ICMP6, free it.
  397          */
  398         m_freem(m);
  399 }
  400 
  401 /*
  402  * Process a received ICMP6 message.
  403  */
  404 int
  405 icmp6_input(struct mbuf **mp, int *offp, int proto)
  406 {
  407         struct mbuf *m = *mp, *n;
  408         struct ifnet *ifp;
  409         struct ip6_hdr *ip6, *nip6;
  410         struct icmp6_hdr *icmp6, *nicmp6;
  411         int off = *offp;
  412         int icmp6len = m->m_pkthdr.len - *offp;
  413         int code, sum, noff;
  414         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
  415         int ip6len, error;
  416 
  417         ifp = m->m_pkthdr.rcvif;
  418 
  419 #ifndef PULLDOWN_TEST
  420         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
  421         /* m might change if M_LOOP.  So, call mtod after this */
  422 #endif
  423 
  424         /*
  425          * Locate icmp6 structure in mbuf, and check
  426          * that not corrupted and of at least minimum length
  427          */
  428 
  429         ip6 = mtod(m, struct ip6_hdr *);
  430         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
  431         if (icmp6len < sizeof(struct icmp6_hdr)) {
  432                 ICMP6STAT_INC(icp6s_tooshort);
  433                 goto freeit;
  434         }
  435 
  436         /*
  437          * Check multicast group membership.
  438          * Note: SSM filters are not applied for ICMPv6 traffic.
  439          */
  440         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
  441                 struct in6_multi        *inm;
  442 
  443                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
  444                 if (inm == NULL) {
  445                         IP6STAT_INC(ip6s_notmember);
  446                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
  447                         goto freeit;
  448                 }
  449         }
  450 
  451         /*
  452          * calculate the checksum
  453          */
  454 #ifndef PULLDOWN_TEST
  455         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
  456 #else
  457         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
  458         if (icmp6 == NULL) {
  459                 ICMP6STAT_INC(icp6s_tooshort);
  460                 return IPPROTO_DONE;
  461         }
  462 #endif
  463         code = icmp6->icmp6_code;
  464 
  465         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
  466                 nd6log((LOG_ERR,
  467                     "ICMP6 checksum error(%d|%x) %s\n",
  468                     icmp6->icmp6_type, sum,
  469                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
  470                 ICMP6STAT_INC(icp6s_checksum);
  471                 goto freeit;
  472         }
  473 
  474         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
  475                 /*
  476                  * Deliver very specific ICMP6 type only.
  477                  * This is important to deliver TOOBIG.  Otherwise PMTUD
  478                  * will not work.
  479                  */
  480                 switch (icmp6->icmp6_type) {
  481                 case ICMP6_DST_UNREACH:
  482                 case ICMP6_PACKET_TOO_BIG:
  483                 case ICMP6_TIME_EXCEEDED:
  484                         break;
  485                 default:
  486                         goto freeit;
  487                 }
  488         }
  489 
  490         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
  491         icmp6_ifstat_inc(ifp, ifs6_in_msg);
  492         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
  493                 icmp6_ifstat_inc(ifp, ifs6_in_error);
  494 
  495         switch (icmp6->icmp6_type) {
  496         case ICMP6_DST_UNREACH:
  497                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
  498                 switch (code) {
  499                 case ICMP6_DST_UNREACH_NOROUTE:
  500                         code = PRC_UNREACH_NET;
  501                         break;
  502                 case ICMP6_DST_UNREACH_ADMIN:
  503                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
  504                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
  505                         break;
  506                 case ICMP6_DST_UNREACH_ADDR:
  507                         code = PRC_HOSTDEAD;
  508                         break;
  509                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
  510                         /* I mean "source address was incorrect." */
  511                         code = PRC_PARAMPROB;
  512                         break;
  513                 case ICMP6_DST_UNREACH_NOPORT:
  514                         code = PRC_UNREACH_PORT;
  515                         break;
  516                 default:
  517                         goto badcode;
  518                 }
  519                 goto deliver;
  520                 break;
  521 
  522         case ICMP6_PACKET_TOO_BIG:
  523                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
  524 
  525                 /* validation is made in icmp6_mtudisc_update */
  526 
  527                 code = PRC_MSGSIZE;
  528 
  529                 /*
  530                  * Updating the path MTU will be done after examining
  531                  * intermediate extension headers.
  532                  */
  533                 goto deliver;
  534                 break;
  535 
  536         case ICMP6_TIME_EXCEEDED:
  537                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
  538                 switch (code) {
  539                 case ICMP6_TIME_EXCEED_TRANSIT:
  540                         code = PRC_TIMXCEED_INTRANS;
  541                         break;
  542                 case ICMP6_TIME_EXCEED_REASSEMBLY:
  543                         code = PRC_TIMXCEED_REASS;
  544                         break;
  545                 default:
  546                         goto badcode;
  547                 }
  548                 goto deliver;
  549                 break;
  550 
  551         case ICMP6_PARAM_PROB:
  552                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
  553                 switch (code) {
  554                 case ICMP6_PARAMPROB_NEXTHEADER:
  555                         code = PRC_UNREACH_PROTOCOL;
  556                         break;
  557                 case ICMP6_PARAMPROB_HEADER:
  558                 case ICMP6_PARAMPROB_OPTION:
  559                         code = PRC_PARAMPROB;
  560                         break;
  561                 default:
  562                         goto badcode;
  563                 }
  564                 goto deliver;
  565                 break;
  566 
  567         case ICMP6_ECHO_REQUEST:
  568                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
  569                 if (code != 0)
  570                         goto badcode;
  571                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
  572                         /* Give up remote */
  573                         break;
  574                 }
  575                 if ((n->m_flags & M_EXT) != 0
  576                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
  577                         struct mbuf *n0 = n;
  578                         int n0len;
  579 
  580                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
  581                         n = m_gethdr(M_NOWAIT, n0->m_type);
  582                         if (n == NULL) {
  583                                 /* Give up remote */
  584                                 m_freem(n0);
  585                                 break;
  586                         }
  587 
  588                         m_move_pkthdr(n, n0);   /* FIB copied. */
  589                         n0len = n0->m_pkthdr.len;       /* save for use below */
  590                         /*
  591                          * Copy IPv6 and ICMPv6 only.
  592                          */
  593                         nip6 = mtod(n, struct ip6_hdr *);
  594                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
  595                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
  596                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
  597                         noff = sizeof(struct ip6_hdr);
  598                         /* new mbuf contains only ipv6+icmpv6 headers */
  599                         n->m_len = noff + sizeof(struct icmp6_hdr);
  600                         /*
  601                          * Adjust mbuf.  ip6_plen will be adjusted in
  602                          * ip6_output().
  603                          */
  604                         m_adj(n0, off + sizeof(struct icmp6_hdr));
  605                         /* recalculate complete packet size */
  606                         n->m_pkthdr.len = n0len + (noff - off);
  607                         n->m_next = n0;
  608                 } else {
  609                         nip6 = mtod(n, struct ip6_hdr *);
  610                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
  611                             sizeof(*nicmp6));
  612                         noff = off;
  613                 }
  614                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
  615                 nicmp6->icmp6_code = 0;
  616                 if (n) {
  617                         ICMP6STAT_INC(icp6s_reflect);
  618                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
  619                         icmp6_reflect(n, noff);
  620                 }
  621                 break;
  622 
  623         case ICMP6_ECHO_REPLY:
  624                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
  625                 if (code != 0)
  626                         goto badcode;
  627                 break;
  628 
  629         case MLD_LISTENER_QUERY:
  630         case MLD_LISTENER_REPORT:
  631         case MLD_LISTENER_DONE:
  632         case MLDV2_LISTENER_REPORT:
  633                 /*
  634                  * Drop MLD traffic which is not link-local, has a hop limit
  635                  * of greater than 1 hop, or which does not have the
  636                  * IPv6 HBH Router Alert option.
  637                  * As IPv6 HBH options are stripped in ip6_input() we must
  638                  * check an mbuf header flag.
  639                  * XXX Should we also sanity check that these messages
  640                  * were directed to a link-local multicast prefix?
  641                  */
  642                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
  643                         goto freeit;
  644                 if (mld_input(m, off, icmp6len) != 0)
  645                         return (IPPROTO_DONE);
  646                 /* m stays. */
  647                 break;
  648 
  649         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
  650             {
  651                 enum { WRU, FQDN } mode;
  652 
  653                 if (!V_icmp6_nodeinfo)
  654                         break;
  655 
  656                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
  657                         mode = WRU;
  658                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
  659                         mode = FQDN;
  660                 else
  661                         goto badlen;
  662 
  663                 if (mode == FQDN) {
  664 #ifndef PULLDOWN_TEST
  665                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
  666                             IPPROTO_DONE);
  667 #endif
  668                         n = m_copy(m, 0, M_COPYALL);
  669                         if (n)
  670                                 n = ni6_input(n, off);
  671                         /* XXX meaningless if n == NULL */
  672                         noff = sizeof(struct ip6_hdr);
  673                 } else {
  674                         struct prison *pr;
  675                         u_char *p;
  676                         int maxhlen, hlen;
  677 
  678                         /*
  679                          * XXX: this combination of flags is pointless,
  680                          * but should we keep this for compatibility?
  681                          */
  682                         if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
  683                             ICMP6_NODEINFO_TMPADDROK)) !=
  684                             (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
  685                                 break;
  686 
  687                         if (code != 0)
  688                                 goto badcode;
  689 
  690                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
  691                         n = m_gethdr(M_NOWAIT, m->m_type);
  692                         if (n == NULL) {
  693                                 /* Give up remote */
  694                                 break;
  695                         }
  696                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
  697                                 /*
  698                                  * Previous code did a blind M_COPY_PKTHDR
  699                                  * and said "just for rcvif".  If true, then
  700                                  * we could tolerate the dup failing (due to
  701                                  * the deep copy of the tag chain).  For now
  702                                  * be conservative and just fail.
  703                                  */
  704                                 m_free(n);
  705                                 n = NULL;
  706                         }
  707                         maxhlen = M_TRAILINGSPACE(n) -
  708                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
  709                         pr = curthread->td_ucred->cr_prison;
  710                         mtx_lock(&pr->pr_mtx);
  711                         hlen = strlen(pr->pr_hostname);
  712                         if (maxhlen > hlen)
  713                                 maxhlen = hlen;
  714                         /*
  715                          * Copy IPv6 and ICMPv6 only.
  716                          */
  717                         nip6 = mtod(n, struct ip6_hdr *);
  718                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
  719                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
  720                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
  721                         p = (u_char *)(nicmp6 + 1);
  722                         bzero(p, 4);
  723                         /* meaningless TTL */
  724                         bcopy(pr->pr_hostname, p + 4, maxhlen);
  725                         mtx_unlock(&pr->pr_mtx);
  726                         noff = sizeof(struct ip6_hdr);
  727                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
  728                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
  729                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
  730                         nicmp6->icmp6_code = 0;
  731                 }
  732                 if (n) {
  733                         ICMP6STAT_INC(icp6s_reflect);
  734                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
  735                         icmp6_reflect(n, noff);
  736                 }
  737                 break;
  738             }
  739 
  740         case ICMP6_WRUREPLY:
  741                 if (code != 0)
  742                         goto badcode;
  743                 break;
  744 
  745         case ND_ROUTER_SOLICIT:
  746                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
  747                 if (code != 0)
  748                         goto badcode;
  749                 if (icmp6len < sizeof(struct nd_router_solicit))
  750                         goto badlen;
  751                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
  752                         /* give up local */
  753 
  754                         /* Send incoming SeND packet to user space. */
  755                         if (send_sendso_input_hook != NULL) {
  756                                 IP6_EXTHDR_CHECK(m, off,
  757                                     icmp6len, IPPROTO_DONE);
  758                                 error = send_sendso_input_hook(m, ifp,
  759                                     SND_IN, ip6len);
  760                                 /* -1 == no app on SEND socket */
  761                                 if (error == 0)
  762                                         return (IPPROTO_DONE);
  763                                 nd6_rs_input(m, off, icmp6len);
  764                         } else
  765                                 nd6_rs_input(m, off, icmp6len);
  766                         m = NULL;
  767                         goto freeit;
  768                 }
  769                 if (send_sendso_input_hook != NULL) {
  770                         IP6_EXTHDR_CHECK(n, off,
  771                             icmp6len, IPPROTO_DONE);
  772                         error = send_sendso_input_hook(n, ifp,
  773                             SND_IN, ip6len);
  774                         if (error == 0)
  775                                 goto freeit;
  776                         /* -1 == no app on SEND socket */
  777                         nd6_rs_input(n, off, icmp6len);
  778                 } else
  779                         nd6_rs_input(n, off, icmp6len);
  780                 /* m stays. */
  781                 break;
  782 
  783         case ND_ROUTER_ADVERT:
  784                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
  785                 if (code != 0)
  786                         goto badcode;
  787                 if (icmp6len < sizeof(struct nd_router_advert))
  788                         goto badlen;
  789                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
  790 
  791                         /* Send incoming SeND-protected/ND packet to user space. */
  792                         if (send_sendso_input_hook != NULL) {
  793                                 error = send_sendso_input_hook(m, ifp,
  794                                     SND_IN, ip6len);
  795                                 if (error == 0)
  796                                         return (IPPROTO_DONE);
  797                                 nd6_ra_input(m, off, icmp6len);
  798                         } else
  799                                 nd6_ra_input(m, off, icmp6len);
  800                         m = NULL;
  801                         goto freeit;
  802                 }
  803                 if (send_sendso_input_hook != NULL) {
  804                         error = send_sendso_input_hook(n, ifp,
  805                             SND_IN, ip6len);
  806                         if (error == 0)
  807                                 goto freeit;
  808                         nd6_ra_input(n, off, icmp6len);
  809                 } else
  810                         nd6_ra_input(n, off, icmp6len);
  811                 /* m stays. */
  812                 break;
  813 
  814         case ND_NEIGHBOR_SOLICIT:
  815                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
  816                 if (code != 0)
  817                         goto badcode;
  818                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
  819                         goto badlen;
  820                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
  821                         if (send_sendso_input_hook != NULL) {
  822                                 error = send_sendso_input_hook(m, ifp,
  823                                     SND_IN, ip6len);
  824                                 if (error == 0)
  825                                         return (IPPROTO_DONE);
  826                                 nd6_ns_input(m, off, icmp6len);
  827                         } else
  828                                 nd6_ns_input(m, off, icmp6len);
  829                         m = NULL;
  830                         goto freeit;
  831                 }
  832                 if (send_sendso_input_hook != NULL) {
  833                         error = send_sendso_input_hook(n, ifp,
  834                             SND_IN, ip6len);
  835                         if (error == 0)
  836                                 goto freeit;
  837                         nd6_ns_input(n, off, icmp6len);
  838                 } else
  839                         nd6_ns_input(n, off, icmp6len);
  840                 /* m stays. */
  841                 break;
  842 
  843         case ND_NEIGHBOR_ADVERT:
  844                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
  845                 if (code != 0)
  846                         goto badcode;
  847                 if (icmp6len < sizeof(struct nd_neighbor_advert))
  848                         goto badlen;
  849                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
  850 
  851                         /* Send incoming SeND-protected/ND packet to user space. */
  852                         if (send_sendso_input_hook != NULL) {
  853                                 error = send_sendso_input_hook(m, ifp,
  854                                     SND_IN, ip6len);
  855                                 if (error == 0)
  856                                         return (IPPROTO_DONE);
  857                                 nd6_na_input(m, off, icmp6len);
  858                         } else
  859                                 nd6_na_input(m, off, icmp6len);
  860                         m = NULL;
  861                         goto freeit;
  862                 }
  863                 if (send_sendso_input_hook != NULL) {
  864                         error = send_sendso_input_hook(n, ifp,
  865                             SND_IN, ip6len);
  866                         if (error == 0)
  867                                 goto freeit;
  868                         nd6_na_input(n, off, icmp6len);
  869                 } else
  870                         nd6_na_input(n, off, icmp6len);
  871                 /* m stays. */
  872                 break;
  873 
  874         case ND_REDIRECT:
  875                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
  876                 if (code != 0)
  877                         goto badcode;
  878                 if (icmp6len < sizeof(struct nd_redirect))
  879                         goto badlen;
  880                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
  881                         if (send_sendso_input_hook != NULL) {
  882                                 error = send_sendso_input_hook(m, ifp,
  883                                     SND_IN, ip6len);
  884                                 if (error == 0)
  885                                         return (IPPROTO_DONE);
  886                             icmp6_redirect_input(m, off);
  887                         } else
  888                                 icmp6_redirect_input(m, off);
  889                         m = NULL;
  890                         goto freeit;
  891                 }
  892                 if (send_sendso_input_hook != NULL) {
  893                         error = send_sendso_input_hook(n, ifp,
  894                             SND_IN, ip6len);
  895                         if (error == 0)
  896                                 goto freeit;
  897                         icmp6_redirect_input(n, off);
  898                 } else
  899                         icmp6_redirect_input(n, off);
  900                 /* m stays. */
  901                 break;
  902 
  903         case ICMP6_ROUTER_RENUMBERING:
  904                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
  905                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
  906                         goto badcode;
  907                 if (icmp6len < sizeof(struct icmp6_router_renum))
  908                         goto badlen;
  909                 break;
  910 
  911         default:
  912                 nd6log((LOG_DEBUG,
  913                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
  914                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
  915                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
  916                     ifp ? ifp->if_index : 0));
  917                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
  918                         /* ICMPv6 error: MUST deliver it by spec... */
  919                         code = PRC_NCMDS;
  920                         /* deliver */
  921                 } else {
  922                         /* ICMPv6 informational: MUST not deliver */
  923                         break;
  924                 }
  925         deliver:
  926                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
  927                         /* In this case, m should've been freed. */
  928                         return (IPPROTO_DONE);
  929                 }
  930                 break;
  931 
  932         badcode:
  933                 ICMP6STAT_INC(icp6s_badcode);
  934                 break;
  935 
  936         badlen:
  937                 ICMP6STAT_INC(icp6s_badlen);
  938                 break;
  939         }
  940 
  941         /* deliver the packet to appropriate sockets */
  942         icmp6_rip6_input(&m, *offp);
  943 
  944         return IPPROTO_DONE;
  945 
  946  freeit:
  947         m_freem(m);
  948         return IPPROTO_DONE;
  949 }
  950 
  951 static int
  952 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
  953 {
  954         struct mbuf *m = *mp;
  955         struct icmp6_hdr *icmp6;
  956         struct ip6_hdr *eip6;
  957         u_int32_t notifymtu;
  958         struct sockaddr_in6 icmp6src, icmp6dst;
  959 
  960         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
  961                 ICMP6STAT_INC(icp6s_tooshort);
  962                 goto freeit;
  963         }
  964 #ifndef PULLDOWN_TEST
  965         IP6_EXTHDR_CHECK(m, off,
  966             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
  967         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
  968 #else
  969         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
  970             sizeof(*icmp6) + sizeof(struct ip6_hdr));
  971         if (icmp6 == NULL) {
  972                 ICMP6STAT_INC(icp6s_tooshort);
  973                 return (-1);
  974         }
  975 #endif
  976         eip6 = (struct ip6_hdr *)(icmp6 + 1);
  977 
  978         /* Detect the upper level protocol */
  979         {
  980                 void (*ctlfunc)(int, struct sockaddr *, void *);
  981                 u_int8_t nxt = eip6->ip6_nxt;
  982                 int eoff = off + sizeof(struct icmp6_hdr) +
  983                     sizeof(struct ip6_hdr);
  984                 struct ip6ctlparam ip6cp;
  985                 struct in6_addr *finaldst = NULL;
  986                 int icmp6type = icmp6->icmp6_type;
  987                 struct ip6_frag *fh;
  988                 struct ip6_rthdr *rth;
  989                 struct ip6_rthdr0 *rth0;
  990                 int rthlen;
  991 
  992                 while (1) { /* XXX: should avoid infinite loop explicitly? */
  993                         struct ip6_ext *eh;
  994 
  995                         switch (nxt) {
  996                         case IPPROTO_HOPOPTS:
  997                         case IPPROTO_DSTOPTS:
  998                         case IPPROTO_AH:
  999 #ifndef PULLDOWN_TEST
 1000                                 IP6_EXTHDR_CHECK(m, 0,
 1001                                     eoff + sizeof(struct ip6_ext), -1);
 1002                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 1003 #else
 1004                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 1005                                     eoff, sizeof(*eh));
 1006                                 if (eh == NULL) {
 1007                                         ICMP6STAT_INC(icp6s_tooshort);
 1008                                         return (-1);
 1009                                 }
 1010 #endif
 1011 
 1012                                 if (nxt == IPPROTO_AH)
 1013                                         eoff += (eh->ip6e_len + 2) << 2;
 1014                                 else
 1015                                         eoff += (eh->ip6e_len + 1) << 3;
 1016                                 nxt = eh->ip6e_nxt;
 1017                                 break;
 1018                         case IPPROTO_ROUTING:
 1019                                 /*
 1020                                  * When the erroneous packet contains a
 1021                                  * routing header, we should examine the
 1022                                  * header to determine the final destination.
 1023                                  * Otherwise, we can't properly update
 1024                                  * information that depends on the final
 1025                                  * destination (e.g. path MTU).
 1026                                  */
 1027 #ifndef PULLDOWN_TEST
 1028                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 1029                                 rth = (struct ip6_rthdr *)
 1030                                     (mtod(m, caddr_t) + eoff);
 1031 #else
 1032                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 1033                                     eoff, sizeof(*rth));
 1034                                 if (rth == NULL) {
 1035                                         ICMP6STAT_INC(icp6s_tooshort);
 1036                                         return (-1);
 1037                                 }
 1038 #endif
 1039                                 rthlen = (rth->ip6r_len + 1) << 3;
 1040                                 /*
 1041                                  * XXX: currently there is no
 1042                                  * officially defined type other
 1043                                  * than type-0.
 1044                                  * Note that if the segment left field
 1045                                  * is 0, all intermediate hops must
 1046                                  * have been passed.
 1047                                  */
 1048                                 if (rth->ip6r_segleft &&
 1049                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 1050                                         int hops;
 1051 
 1052 #ifndef PULLDOWN_TEST
 1053                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 1054                                         rth0 = (struct ip6_rthdr0 *)
 1055                                             (mtod(m, caddr_t) + eoff);
 1056 #else
 1057                                         IP6_EXTHDR_GET(rth0,
 1058                                             struct ip6_rthdr0 *, m,
 1059                                             eoff, rthlen);
 1060                                         if (rth0 == NULL) {
 1061                                                 ICMP6STAT_INC(icp6s_tooshort);
 1062                                                 return (-1);
 1063                                         }
 1064 #endif
 1065                                         /* just ignore a bogus header */
 1066                                         if ((rth0->ip6r0_len % 2) == 0 &&
 1067                                             (hops = rth0->ip6r0_len/2))
 1068                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 1069                                 }
 1070                                 eoff += rthlen;
 1071                                 nxt = rth->ip6r_nxt;
 1072                                 break;
 1073                         case IPPROTO_FRAGMENT:
 1074 #ifndef PULLDOWN_TEST
 1075                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 1076                                     sizeof(struct ip6_frag), -1);
 1077                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
 1078                                     eoff);
 1079 #else
 1080                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
 1081                                     eoff, sizeof(*fh));
 1082                                 if (fh == NULL) {
 1083                                         ICMP6STAT_INC(icp6s_tooshort);
 1084                                         return (-1);
 1085                                 }
 1086 #endif
 1087                                 /*
 1088                                  * Data after a fragment header is meaningless
 1089                                  * unless it is the first fragment, but
 1090                                  * we'll go to the notify label for path MTU
 1091                                  * discovery.
 1092                                  */
 1093                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
 1094                                         goto notify;
 1095 
 1096                                 eoff += sizeof(struct ip6_frag);
 1097                                 nxt = fh->ip6f_nxt;
 1098                                 break;
 1099                         default:
 1100                                 /*
 1101                                  * This case includes ESP and the No Next
 1102                                  * Header.  In such cases going to the notify
 1103                                  * label does not have any meaning
 1104                                  * (i.e. ctlfunc will be NULL), but we go
 1105                                  * anyway since we might have to update
 1106                                  * path MTU information.
 1107                                  */
 1108                                 goto notify;
 1109                         }
 1110                 }
 1111           notify:
 1112 #ifndef PULLDOWN_TEST
 1113                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 1114 #else
 1115                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 1116                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
 1117                 if (icmp6 == NULL) {
 1118                         ICMP6STAT_INC(icp6s_tooshort);
 1119                         return (-1);
 1120                 }
 1121 #endif
 1122 
 1123                 /*
 1124                  * retrieve parameters from the inner IPv6 header, and convert
 1125                  * them into sockaddr structures.
 1126                  * XXX: there is no guarantee that the source or destination
 1127                  * addresses of the inner packet are in the same scope as
 1128                  * the addresses of the icmp packet.  But there is no other
 1129                  * way to determine the zone.
 1130                  */
 1131                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
 1132 
 1133                 bzero(&icmp6dst, sizeof(icmp6dst));
 1134                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
 1135                 icmp6dst.sin6_family = AF_INET6;
 1136                 if (finaldst == NULL)
 1137                         icmp6dst.sin6_addr = eip6->ip6_dst;
 1138                 else
 1139                         icmp6dst.sin6_addr = *finaldst;
 1140                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
 1141                         goto freeit;
 1142                 bzero(&icmp6src, sizeof(icmp6src));
 1143                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
 1144                 icmp6src.sin6_family = AF_INET6;
 1145                 icmp6src.sin6_addr = eip6->ip6_src;
 1146                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
 1147                         goto freeit;
 1148                 icmp6src.sin6_flowinfo =
 1149                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
 1150 
 1151                 if (finaldst == NULL)
 1152                         finaldst = &eip6->ip6_dst;
 1153                 ip6cp.ip6c_m = m;
 1154                 ip6cp.ip6c_icmp6 = icmp6;
 1155                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
 1156                 ip6cp.ip6c_off = eoff;
 1157                 ip6cp.ip6c_finaldst = finaldst;
 1158                 ip6cp.ip6c_src = &icmp6src;
 1159                 ip6cp.ip6c_nxt = nxt;
 1160 
 1161                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
 1162                         notifymtu = ntohl(icmp6->icmp6_mtu);
 1163                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
 1164                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
 1165                 }
 1166 
 1167                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
 1168                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
 1169                 if (ctlfunc) {
 1170                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
 1171                             &ip6cp);
 1172                 }
 1173         }
 1174         *mp = m;
 1175         return (0);
 1176 
 1177   freeit:
 1178         m_freem(m);
 1179         return (-1);
 1180 }
 1181 
 1182 void
 1183 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
 1184 {
 1185         struct in6_addr *dst = ip6cp->ip6c_finaldst;
 1186         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
 1187         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
 1188         u_int mtu = ntohl(icmp6->icmp6_mtu);
 1189         struct in_conninfo inc;
 1190 
 1191 #if 0
 1192         /*
 1193          * RFC2460 section 5, last paragraph.
 1194          * even though minimum link MTU for IPv6 is IPV6_MMTU,
 1195          * we may see ICMPv6 too big with mtu < IPV6_MMTU
 1196          * due to packet translator in the middle.
 1197          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
 1198          * special handling.
 1199          */
 1200         if (mtu < IPV6_MMTU)
 1201                 return;
 1202 #endif
 1203 
 1204         /*
 1205          * we reject ICMPv6 too big with abnormally small value.
 1206          * XXX what is the good definition of "abnormally small"?
 1207          */
 1208         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
 1209                 return;
 1210 
 1211         if (!validated)
 1212                 return;
 1213 
 1214         /*
 1215          * In case the suggested mtu is less than IPV6_MMTU, we
 1216          * only need to remember that it was for above mentioned
 1217          * "alwaysfrag" case.
 1218          * Try to be as close to the spec as possible.
 1219          */
 1220         if (mtu < IPV6_MMTU)
 1221                 mtu = IPV6_MMTU - 8;
 1222 
 1223         bzero(&inc, sizeof(inc));
 1224         inc.inc_fibnum = M_GETFIB(m);
 1225         inc.inc_flags |= INC_ISIPV6;
 1226         inc.inc6_faddr = *dst;
 1227         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
 1228                 return;
 1229 
 1230         if (mtu < tcp_maxmtu6(&inc, NULL)) {
 1231                 tcp_hc_updatemtu(&inc, mtu);
 1232                 ICMP6STAT_INC(icp6s_pmtuchg);
 1233         }
 1234 }
 1235 
 1236 /*
 1237  * Process a Node Information Query packet, based on
 1238  * draft-ietf-ipngwg-icmp-name-lookups-07.
 1239  *
 1240  * Spec incompatibilities:
 1241  * - IPv6 Subject address handling
 1242  * - IPv4 Subject address handling support missing
 1243  * - Proxy reply (answer even if it's not for me)
 1244  * - joins NI group address at in6_ifattach() time only, does not cope
 1245  *   with hostname changes by sethostname(3)
 1246  */
 1247 static struct mbuf *
 1248 ni6_input(struct mbuf *m, int off)
 1249 {
 1250         struct icmp6_nodeinfo *ni6, *nni6;
 1251         struct mbuf *n = NULL;
 1252         struct prison *pr;
 1253         u_int16_t qtype;
 1254         int subjlen;
 1255         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
 1256         struct ni_reply_fqdn *fqdn;
 1257         int addrs;              /* for NI_QTYPE_NODEADDR */
 1258         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
 1259         struct in6_addr in6_subj; /* subject address */
 1260         struct ip6_hdr *ip6;
 1261         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
 1262         char *subj = NULL;
 1263         struct in6_ifaddr *ia6 = NULL;
 1264 
 1265         ip6 = mtod(m, struct ip6_hdr *);
 1266 #ifndef PULLDOWN_TEST
 1267         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
 1268 #else
 1269         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
 1270         if (ni6 == NULL) {
 1271                 /* m is already reclaimed */
 1272                 return (NULL);
 1273         }
 1274 #endif
 1275 
 1276         /*
 1277          * Validate IPv6 source address.
 1278          * The default configuration MUST be to refuse answering queries from
 1279          * global-scope addresses according to RFC4602.
 1280          * Notes:
 1281          *  - it's not very clear what "refuse" means; this implementation
 1282          *    simply drops it.
 1283          *  - it's not very easy to identify global-scope (unicast) addresses
 1284          *    since there are many prefixes for them.  It should be safer
 1285          *    and in practice sufficient to check "all" but loopback and
 1286          *    link-local (note that site-local unicast was deprecated and
 1287          *    ULA is defined as global scope-wise)
 1288          */
 1289         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
 1290             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
 1291             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
 1292                 goto bad;
 1293 
 1294         /*
 1295          * Validate IPv6 destination address.
 1296          *
 1297          * The Responder must discard the Query without further processing
 1298          * unless it is one of the Responder's unicast or anycast addresses, or
 1299          * a link-local scope multicast address which the Responder has joined.
 1300          * [RFC4602, Section 5.]
 1301          */
 1302         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 1303                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
 1304                         goto bad;
 1305                 /* else it's a link-local multicast, fine */
 1306         } else {                /* unicast or anycast */
 1307                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
 1308                         goto bad; /* XXX impossible */
 1309 
 1310                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
 1311                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
 1312                         ifa_free(&ia6->ia_ifa);
 1313                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
 1314                                 "a temporary address in %s:%d",
 1315                                __FILE__, __LINE__));
 1316                         goto bad;
 1317                 }
 1318                 ifa_free(&ia6->ia_ifa);
 1319         }
 1320 
 1321         /* validate query Subject field. */
 1322         qtype = ntohs(ni6->ni_qtype);
 1323         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
 1324         switch (qtype) {
 1325         case NI_QTYPE_NOOP:
 1326         case NI_QTYPE_SUPTYPES:
 1327                 /* 07 draft */
 1328                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
 1329                         break;
 1330                 /* FALLTHROUGH */
 1331         case NI_QTYPE_FQDN:
 1332         case NI_QTYPE_NODEADDR:
 1333         case NI_QTYPE_IPV4ADDR:
 1334                 switch (ni6->ni_code) {
 1335                 case ICMP6_NI_SUBJ_IPV6:
 1336 #if ICMP6_NI_SUBJ_IPV6 != 0
 1337                 case 0:
 1338 #endif
 1339                         /*
 1340                          * backward compatibility - try to accept 03 draft
 1341                          * format, where no Subject is present.
 1342                          */
 1343                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
 1344                             subjlen == 0) {
 1345                                 oldfqdn++;
 1346                                 break;
 1347                         }
 1348 #if ICMP6_NI_SUBJ_IPV6 != 0
 1349                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
 1350                                 goto bad;
 1351 #endif
 1352 
 1353                         if (subjlen != sizeof(struct in6_addr))
 1354                                 goto bad;
 1355 
 1356                         /*
 1357                          * Validate Subject address.
 1358                          *
 1359                          * Not sure what exactly "address belongs to the node"
 1360                          * means in the spec, is it just unicast, or what?
 1361                          *
 1362                          * At this moment we consider Subject address as
 1363                          * "belong to the node" if the Subject address equals
 1364                          * to the IPv6 destination address; validation for
 1365                          * IPv6 destination address should have done enough
 1366                          * check for us.
 1367                          *
 1368                          * We do not do proxy at this moment.
 1369                          */
 1370                         /* m_pulldown instead of copy? */
 1371                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
 1372                             subjlen, (caddr_t)&in6_subj);
 1373                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
 1374                                 goto bad;
 1375 
 1376                         subj = (char *)&in6_subj;
 1377                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
 1378                                 break;
 1379 
 1380                         /*
 1381                          * XXX if we are to allow other cases, we should really
 1382                          * be careful about scope here.
 1383                          * basically, we should disallow queries toward IPv6
 1384                          * destination X with subject Y,
 1385                          * if scope(X) > scope(Y).
 1386                          * if we allow scope(X) > scope(Y), it will result in
 1387                          * information leakage across scope boundary.
 1388                          */
 1389                         goto bad;
 1390 
 1391                 case ICMP6_NI_SUBJ_FQDN:
 1392                         /*
 1393                          * Validate Subject name with gethostname(3).
 1394                          *
 1395                          * The behavior may need some debate, since:
 1396                          * - we are not sure if the node has FQDN as
 1397                          *   hostname (returned by gethostname(3)).
 1398                          * - the code does wildcard match for truncated names.
 1399                          *   however, we are not sure if we want to perform
 1400                          *   wildcard match, if gethostname(3) side has
 1401                          *   truncated hostname.
 1402                          */
 1403                         pr = curthread->td_ucred->cr_prison;
 1404                         mtx_lock(&pr->pr_mtx);
 1405                         n = ni6_nametodns(pr->pr_hostname,
 1406                             strlen(pr->pr_hostname), 0);
 1407                         mtx_unlock(&pr->pr_mtx);
 1408                         if (!n || n->m_next || n->m_len == 0)
 1409                                 goto bad;
 1410                         IP6_EXTHDR_GET(subj, char *, m,
 1411                             off + sizeof(struct icmp6_nodeinfo), subjlen);
 1412                         if (subj == NULL)
 1413                                 goto bad;
 1414                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
 1415                             n->m_len)) {
 1416                                 goto bad;
 1417                         }
 1418                         m_freem(n);
 1419                         n = NULL;
 1420                         break;
 1421 
 1422                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
 1423                 default:
 1424                         goto bad;
 1425                 }
 1426                 break;
 1427         }
 1428 
 1429         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
 1430         switch (qtype) {
 1431         case NI_QTYPE_FQDN:
 1432                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
 1433                         goto bad;
 1434                 break;
 1435         case NI_QTYPE_NODEADDR:
 1436         case NI_QTYPE_IPV4ADDR:
 1437                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
 1438                         goto bad;
 1439                 break;
 1440         }
 1441 
 1442         /* guess reply length */
 1443         switch (qtype) {
 1444         case NI_QTYPE_NOOP:
 1445                 break;          /* no reply data */
 1446         case NI_QTYPE_SUPTYPES:
 1447                 replylen += sizeof(u_int32_t);
 1448                 break;
 1449         case NI_QTYPE_FQDN:
 1450                 /* XXX will append an mbuf */
 1451                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
 1452                 break;
 1453         case NI_QTYPE_NODEADDR:
 1454                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
 1455                 if ((replylen += addrs * (sizeof(struct in6_addr) +
 1456                     sizeof(u_int32_t))) > MCLBYTES)
 1457                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
 1458                 break;
 1459         case NI_QTYPE_IPV4ADDR:
 1460                 /* unsupported - should respond with unknown Qtype? */
 1461                 break;
 1462         default:
 1463                 /*
 1464                  * XXX: We must return a reply with the ICMP6 code
 1465                  * `unknown Qtype' in this case.  However we regard the case
 1466                  * as an FQDN query for backward compatibility.
 1467                  * Older versions set a random value to this field,
 1468                  * so it rarely varies in the defined qtypes.
 1469                  * But the mechanism is not reliable...
 1470                  * maybe we should obsolete older versions.
 1471                  */
 1472                 qtype = NI_QTYPE_FQDN;
 1473                 /* XXX will append an mbuf */
 1474                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
 1475                 oldfqdn++;
 1476                 break;
 1477         }
 1478 
 1479         /* Allocate an mbuf to reply. */
 1480         if (replylen > MCLBYTES) {
 1481                 /*
 1482                  * XXX: should we try to allocate more? But MCLBYTES
 1483                  * is probably much larger than IPV6_MMTU...
 1484                  */
 1485                 goto bad;
 1486         }
 1487         if (replylen > MHLEN)
 1488                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
 1489         else
 1490                 n = m_gethdr(M_NOWAIT, m->m_type);
 1491         if (n == NULL) {
 1492                 m_freem(m);
 1493                 return (NULL);
 1494         }
 1495         m_move_pkthdr(n, m); /* just for recvif and FIB */
 1496         n->m_pkthdr.len = n->m_len = replylen;
 1497 
 1498         /* copy mbuf header and IPv6 + Node Information base headers */
 1499         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
 1500         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
 1501         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
 1502 
 1503         /* qtype dependent procedure */
 1504         switch (qtype) {
 1505         case NI_QTYPE_NOOP:
 1506                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1507                 nni6->ni_flags = 0;
 1508                 break;
 1509         case NI_QTYPE_SUPTYPES:
 1510         {
 1511                 u_int32_t v;
 1512                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1513                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
 1514                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
 1515                 v = (u_int32_t)htonl(0x0000000f);
 1516                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
 1517                 break;
 1518         }
 1519         case NI_QTYPE_FQDN:
 1520                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1521                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
 1522                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
 1523                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
 1524                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
 1525                 /*
 1526                  * XXX do we really have FQDN in hostname?
 1527                  */
 1528                 pr = curthread->td_ucred->cr_prison;
 1529                 mtx_lock(&pr->pr_mtx);
 1530                 n->m_next = ni6_nametodns(pr->pr_hostname,
 1531                     strlen(pr->pr_hostname), oldfqdn);
 1532                 mtx_unlock(&pr->pr_mtx);
 1533                 if (n->m_next == NULL)
 1534                         goto bad;
 1535                 /* XXX we assume that n->m_next is not a chain */
 1536                 if (n->m_next->m_next != NULL)
 1537                         goto bad;
 1538                 n->m_pkthdr.len += n->m_next->m_len;
 1539                 break;
 1540         case NI_QTYPE_NODEADDR:
 1541         {
 1542                 int lenlim, copied;
 1543 
 1544                 nni6->ni_code = ICMP6_NI_SUCCESS;
 1545                 n->m_pkthdr.len = n->m_len =
 1546                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
 1547                 lenlim = M_TRAILINGSPACE(n);
 1548                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
 1549                 /* XXX: reset mbuf length */
 1550                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 1551                     sizeof(struct icmp6_nodeinfo) + copied;
 1552                 break;
 1553         }
 1554         default:
 1555                 break;          /* XXX impossible! */
 1556         }
 1557 
 1558         nni6->ni_type = ICMP6_NI_REPLY;
 1559         m_freem(m);
 1560         return (n);
 1561 
 1562   bad:
 1563         m_freem(m);
 1564         if (n)
 1565                 m_freem(n);
 1566         return (NULL);
 1567 }
 1568 
 1569 /*
 1570  * make a mbuf with DNS-encoded string.  no compression support.
 1571  *
 1572  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
 1573  * treated as truncated name (two \0 at the end).  this is a wild guess.
 1574  *
 1575  * old - return pascal string if non-zero
 1576  */
 1577 static struct mbuf *
 1578 ni6_nametodns(const char *name, int namelen, int old)
 1579 {
 1580         struct mbuf *m;
 1581         char *cp, *ep;
 1582         const char *p, *q;
 1583         int i, len, nterm;
 1584 
 1585         if (old)
 1586                 len = namelen + 1;
 1587         else
 1588                 len = MCLBYTES;
 1589 
 1590         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
 1591         if (len > MLEN)
 1592                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
 1593         else
 1594                 m = m_get(M_NOWAIT, MT_DATA);
 1595         if (m == NULL)
 1596                 goto fail;
 1597 
 1598         if (old) {
 1599                 m->m_len = len;
 1600                 *mtod(m, char *) = namelen;
 1601                 bcopy(name, mtod(m, char *) + 1, namelen);
 1602                 return m;
 1603         } else {
 1604                 m->m_len = 0;
 1605                 cp = mtod(m, char *);
 1606                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
 1607 
 1608                 /* if not certain about my name, return empty buffer */
 1609                 if (namelen == 0)
 1610                         return m;
 1611 
 1612                 /*
 1613                  * guess if it looks like shortened hostname, or FQDN.
 1614                  * shortened hostname needs two trailing "\0".
 1615                  */
 1616                 i = 0;
 1617                 for (p = name; p < name + namelen; p++) {
 1618                         if (*p && *p == '.')
 1619                                 i++;
 1620                 }
 1621                 if (i < 2)
 1622                         nterm = 2;
 1623                 else
 1624                         nterm = 1;
 1625 
 1626                 p = name;
 1627                 while (cp < ep && p < name + namelen) {
 1628                         i = 0;
 1629                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
 1630                                 i++;
 1631                         /* result does not fit into mbuf */
 1632                         if (cp + i + 1 >= ep)
 1633                                 goto fail;
 1634                         /*
 1635                          * DNS label length restriction, RFC1035 page 8.
 1636                          * "i == 0" case is included here to avoid returning
 1637                          * 0-length label on "foo..bar".
 1638                          */
 1639                         if (i <= 0 || i >= 64)
 1640                                 goto fail;
 1641                         *cp++ = i;
 1642                         bcopy(p, cp, i);
 1643                         cp += i;
 1644                         p = q;
 1645                         if (p < name + namelen && *p == '.')
 1646                                 p++;
 1647                 }
 1648                 /* termination */
 1649                 if (cp + nterm >= ep)
 1650                         goto fail;
 1651                 while (nterm-- > 0)
 1652                         *cp++ = '\0';
 1653                 m->m_len = cp - mtod(m, char *);
 1654                 return m;
 1655         }
 1656 
 1657         panic("should not reach here");
 1658         /* NOTREACHED */
 1659 
 1660  fail:
 1661         if (m)
 1662                 m_freem(m);
 1663         return NULL;
 1664 }
 1665 
 1666 /*
 1667  * check if two DNS-encoded string matches.  takes care of truncated
 1668  * form (with \0\0 at the end).  no compression support.
 1669  * XXX upper/lowercase match (see RFC2065)
 1670  */
 1671 static int
 1672 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
 1673 {
 1674         const char *a0, *b0;
 1675         int l;
 1676 
 1677         /* simplest case - need validation? */
 1678         if (alen == blen && bcmp(a, b, alen) == 0)
 1679                 return 1;
 1680 
 1681         a0 = a;
 1682         b0 = b;
 1683 
 1684         /* termination is mandatory */
 1685         if (alen < 2 || blen < 2)
 1686                 return 0;
 1687         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
 1688                 return 0;
 1689         alen--;
 1690         blen--;
 1691 
 1692         while (a - a0 < alen && b - b0 < blen) {
 1693                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
 1694                         return 0;
 1695 
 1696                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
 1697                         return 0;
 1698                 /* we don't support compression yet */
 1699                 if (a[0] >= 64 || b[0] >= 64)
 1700                         return 0;
 1701 
 1702                 /* truncated case */
 1703                 if (a[0] == 0 && a - a0 == alen - 1)
 1704                         return 1;
 1705                 if (b[0] == 0 && b - b0 == blen - 1)
 1706                         return 1;
 1707                 if (a[0] == 0 || b[0] == 0)
 1708                         return 0;
 1709 
 1710                 if (a[0] != b[0])
 1711                         return 0;
 1712                 l = a[0];
 1713                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
 1714                         return 0;
 1715                 if (bcmp(a + 1, b + 1, l) != 0)
 1716                         return 0;
 1717 
 1718                 a += 1 + l;
 1719                 b += 1 + l;
 1720         }
 1721 
 1722         if (a - a0 == alen && b - b0 == blen)
 1723                 return 1;
 1724         else
 1725                 return 0;
 1726 }
 1727 
 1728 /*
 1729  * calculate the number of addresses to be returned in the node info reply.
 1730  */
 1731 static int
 1732 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
 1733     struct in6_addr *subj)
 1734 {
 1735         struct ifnet *ifp;
 1736         struct in6_ifaddr *ifa6;
 1737         struct ifaddr *ifa;
 1738         int addrs = 0, addrsofif, iffound = 0;
 1739         int niflags = ni6->ni_flags;
 1740 
 1741         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
 1742                 switch (ni6->ni_code) {
 1743                 case ICMP6_NI_SUBJ_IPV6:
 1744                         if (subj == NULL) /* must be impossible... */
 1745                                 return (0);
 1746                         break;
 1747                 default:
 1748                         /*
 1749                          * XXX: we only support IPv6 subject address for
 1750                          * this Qtype.
 1751                          */
 1752                         return (0);
 1753                 }
 1754         }
 1755 
 1756         IFNET_RLOCK_NOSLEEP();
 1757         TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
 1758                 addrsofif = 0;
 1759                 IF_ADDR_RLOCK(ifp);
 1760                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1761                         if (ifa->ifa_addr->sa_family != AF_INET6)
 1762                                 continue;
 1763                         ifa6 = (struct in6_ifaddr *)ifa;
 1764 
 1765                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
 1766                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
 1767                                 iffound = 1;
 1768 
 1769                         /*
 1770                          * IPv4-mapped addresses can only be returned by a
 1771                          * Node Information proxy, since they represent
 1772                          * addresses of IPv4-only nodes, which perforce do
 1773                          * not implement this protocol.
 1774                          * [icmp-name-lookups-07, Section 5.4]
 1775                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
 1776                          * this function at this moment.
 1777                          */
 1778 
 1779                         /* What do we have to do about ::1? */
 1780                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
 1781                         case IPV6_ADDR_SCOPE_LINKLOCAL:
 1782                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
 1783                                         continue;
 1784                                 break;
 1785                         case IPV6_ADDR_SCOPE_SITELOCAL:
 1786                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
 1787                                         continue;
 1788                                 break;
 1789                         case IPV6_ADDR_SCOPE_GLOBAL:
 1790                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
 1791                                         continue;
 1792                                 break;
 1793                         default:
 1794                                 continue;
 1795                         }
 1796 
 1797                         /*
 1798                          * check if anycast is okay.
 1799                          * XXX: just experimental.  not in the spec.
 1800                          */
 1801                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
 1802                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
 1803                                 continue; /* we need only unicast addresses */
 1804                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
 1805                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
 1806                                 continue;
 1807                         }
 1808                         addrsofif++; /* count the address */
 1809                 }
 1810                 IF_ADDR_RUNLOCK(ifp);
 1811                 if (iffound) {
 1812                         *ifpp = ifp;
 1813                         IFNET_RUNLOCK_NOSLEEP();
 1814                         return (addrsofif);
 1815                 }
 1816 
 1817                 addrs += addrsofif;
 1818         }
 1819         IFNET_RUNLOCK_NOSLEEP();
 1820 
 1821         return (addrs);
 1822 }
 1823 
 1824 static int
 1825 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
 1826     struct ifnet *ifp0, int resid)
 1827 {
 1828         struct ifnet *ifp;
 1829         struct in6_ifaddr *ifa6;
 1830         struct ifaddr *ifa;
 1831         struct ifnet *ifp_dep = NULL;
 1832         int copied = 0, allow_deprecated = 0;
 1833         u_char *cp = (u_char *)(nni6 + 1);
 1834         int niflags = ni6->ni_flags;
 1835         u_int32_t ltime;
 1836 
 1837         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
 1838                 return (0);     /* needless to copy */
 1839 
 1840         IFNET_RLOCK_NOSLEEP();
 1841         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
 1842   again:
 1843 
 1844         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
 1845                 IF_ADDR_RLOCK(ifp);
 1846                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 1847                         if (ifa->ifa_addr->sa_family != AF_INET6)
 1848                                 continue;
 1849                         ifa6 = (struct in6_ifaddr *)ifa;
 1850 
 1851                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
 1852                             allow_deprecated == 0) {
 1853                                 /*
 1854                                  * prefererred address should be put before
 1855                                  * deprecated addresses.
 1856                                  */
 1857 
 1858                                 /* record the interface for later search */
 1859                                 if (ifp_dep == NULL)
 1860                                         ifp_dep = ifp;
 1861 
 1862                                 continue;
 1863                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
 1864                             allow_deprecated != 0)
 1865                                 continue; /* we now collect deprecated addrs */
 1866 
 1867                         /* What do we have to do about ::1? */
 1868                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
 1869                         case IPV6_ADDR_SCOPE_LINKLOCAL:
 1870                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
 1871                                         continue;
 1872                                 break;
 1873                         case IPV6_ADDR_SCOPE_SITELOCAL:
 1874                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
 1875                                         continue;
 1876                                 break;
 1877                         case IPV6_ADDR_SCOPE_GLOBAL:
 1878                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
 1879                                         continue;
 1880                                 break;
 1881                         default:
 1882                                 continue;
 1883                         }
 1884 
 1885                         /*
 1886                          * check if anycast is okay.
 1887                          * XXX: just experimental.  not in the spec.
 1888                          */
 1889                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
 1890                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
 1891                                 continue;
 1892                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
 1893                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
 1894                                 continue;
 1895                         }
 1896 
 1897                         /* now we can copy the address */
 1898                         if (resid < sizeof(struct in6_addr) +
 1899                             sizeof(u_int32_t)) {
 1900                                 IF_ADDR_RUNLOCK(ifp);
 1901                                 /*
 1902                                  * We give up much more copy.
 1903                                  * Set the truncate flag and return.
 1904                                  */
 1905                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
 1906                                 IFNET_RUNLOCK_NOSLEEP();
 1907                                 return (copied);
 1908                         }
 1909 
 1910                         /*
 1911                          * Set the TTL of the address.
 1912                          * The TTL value should be one of the following
 1913                          * according to the specification:
 1914                          *
 1915                          * 1. The remaining lifetime of a DHCP lease on the
 1916                          *    address, or
 1917                          * 2. The remaining Valid Lifetime of a prefix from
 1918                          *    which the address was derived through Stateless
 1919                          *    Autoconfiguration.
 1920                          *
 1921                          * Note that we currently do not support stateful
 1922                          * address configuration by DHCPv6, so the former
 1923                          * case can't happen.
 1924                          */
 1925                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
 1926                                 ltime = ND6_INFINITE_LIFETIME;
 1927                         else {
 1928                                 if (ifa6->ia6_lifetime.ia6t_expire >
 1929                                     time_uptime)
 1930                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
 1931                                 else
 1932                                         ltime = 0;
 1933                         }
 1934 
 1935                         bcopy(&ltime, cp, sizeof(u_int32_t));
 1936                         cp += sizeof(u_int32_t);
 1937 
 1938                         /* copy the address itself */
 1939                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
 1940                             sizeof(struct in6_addr));
 1941                         in6_clearscope((struct in6_addr *)cp); /* XXX */
 1942                         cp += sizeof(struct in6_addr);
 1943 
 1944                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
 1945                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
 1946                 }
 1947                 IF_ADDR_RUNLOCK(ifp);
 1948                 if (ifp0)       /* we need search only on the specified IF */
 1949                         break;
 1950         }
 1951 
 1952         if (allow_deprecated == 0 && ifp_dep != NULL) {
 1953                 ifp = ifp_dep;
 1954                 allow_deprecated = 1;
 1955 
 1956                 goto again;
 1957         }
 1958 
 1959         IFNET_RUNLOCK_NOSLEEP();
 1960 
 1961         return (copied);
 1962 }
 1963 
 1964 /*
 1965  * XXX almost dup'ed code with rip6_input.
 1966  */
 1967 static int
 1968 icmp6_rip6_input(struct mbuf **mp, int off)
 1969 {
 1970         struct mbuf *m = *mp;
 1971         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 1972         struct inpcb *in6p;
 1973         struct inpcb *last = NULL;
 1974         struct sockaddr_in6 fromsa;
 1975         struct icmp6_hdr *icmp6;
 1976         struct mbuf *opts = NULL;
 1977 
 1978 #ifndef PULLDOWN_TEST
 1979         /* this is assumed to be safe. */
 1980         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 1981 #else
 1982         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 1983         if (icmp6 == NULL) {
 1984                 /* m is already reclaimed */
 1985                 return (IPPROTO_DONE);
 1986         }
 1987 #endif
 1988 
 1989         /*
 1990          * XXX: the address may have embedded scope zone ID, which should be
 1991          * hidden from applications.
 1992          */
 1993         bzero(&fromsa, sizeof(fromsa));
 1994         fromsa.sin6_family = AF_INET6;
 1995         fromsa.sin6_len = sizeof(struct sockaddr_in6);
 1996         fromsa.sin6_addr = ip6->ip6_src;
 1997         if (sa6_recoverscope(&fromsa)) {
 1998                 m_freem(m);
 1999                 return (IPPROTO_DONE);
 2000         }
 2001 
 2002         INP_INFO_RLOCK(&V_ripcbinfo);
 2003         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
 2004                 if ((in6p->inp_vflag & INP_IPV6) == 0)
 2005                         continue;
 2006                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
 2007                         continue;
 2008                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
 2009                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
 2010                         continue;
 2011                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
 2012                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
 2013                         continue;
 2014                 INP_RLOCK(in6p);
 2015                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
 2016                     in6p->in6p_icmp6filt)) {
 2017                         INP_RUNLOCK(in6p);
 2018                         continue;
 2019                 }
 2020                 if (last != NULL) {
 2021                         struct  mbuf *n = NULL;
 2022 
 2023                         /*
 2024                          * Recent network drivers tend to allocate a single
 2025                          * mbuf cluster, rather than to make a couple of
 2026                          * mbufs without clusters.  Also, since the IPv6 code
 2027                          * path tries to avoid m_pullup(), it is highly
 2028                          * probable that we still have an mbuf cluster here
 2029                          * even though the necessary length can be stored in an
 2030                          * mbuf's internal buffer.
 2031                          * Meanwhile, the default size of the receive socket
 2032                          * buffer for raw sockets is not so large.  This means
 2033                          * the possibility of packet loss is relatively higher
 2034                          * than before.  To avoid this scenario, we copy the
 2035                          * received data to a separate mbuf that does not use
 2036                          * a cluster, if possible.
 2037                          * XXX: it is better to copy the data after stripping
 2038                          * intermediate headers.
 2039                          */
 2040                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
 2041                             m->m_len <= MHLEN) {
 2042                                 n = m_get(M_NOWAIT, m->m_type);
 2043                                 if (n != NULL) {
 2044                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
 2045                                                 bcopy(m->m_data, n->m_data,
 2046                                                       m->m_len);
 2047                                                 n->m_len = m->m_len;
 2048                                         } else {
 2049                                                 m_free(n);
 2050                                                 n = NULL;
 2051                                         }
 2052                                 }
 2053                         }
 2054                         if (n != NULL ||
 2055                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
 2056                                 if (last->inp_flags & INP_CONTROLOPTS)
 2057                                         ip6_savecontrol(last, n, &opts);
 2058                                 /* strip intermediate headers */
 2059                                 m_adj(n, off);
 2060                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
 2061                                 if (sbappendaddr_locked(
 2062                                     &last->inp_socket->so_rcv,
 2063                                     (struct sockaddr *)&fromsa, n, opts)
 2064                                     == 0) {
 2065                                         /* should notify about lost packet */
 2066                                         m_freem(n);
 2067                                         if (opts) {
 2068                                                 m_freem(opts);
 2069                                         }
 2070                                         SOCKBUF_UNLOCK(
 2071                                             &last->inp_socket->so_rcv);
 2072                                 } else
 2073                                         sorwakeup_locked(last->inp_socket);
 2074                                 opts = NULL;
 2075                         }
 2076                         INP_RUNLOCK(last);
 2077                 }
 2078                 last = in6p;
 2079         }
 2080         INP_INFO_RUNLOCK(&V_ripcbinfo);
 2081         if (last != NULL) {
 2082                 if (last->inp_flags & INP_CONTROLOPTS)
 2083                         ip6_savecontrol(last, m, &opts);
 2084                 /* strip intermediate headers */
 2085                 m_adj(m, off);
 2086 
 2087                 /* avoid using mbuf clusters if possible (see above) */
 2088                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
 2089                     m->m_len <= MHLEN) {
 2090                         struct mbuf *n;
 2091 
 2092                         n = m_get(M_NOWAIT, m->m_type);
 2093                         if (n != NULL) {
 2094                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
 2095                                         bcopy(m->m_data, n->m_data, m->m_len);
 2096                                         n->m_len = m->m_len;
 2097 
 2098                                         m_freem(m);
 2099                                         m = n;
 2100                                 } else {
 2101                                         m_freem(n);
 2102                                         n = NULL;
 2103                                 }
 2104                         }
 2105                 }
 2106                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
 2107                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
 2108                     (struct sockaddr *)&fromsa, m, opts) == 0) {
 2109                         m_freem(m);
 2110                         if (opts)
 2111                                 m_freem(opts);
 2112                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
 2113                 } else
 2114                         sorwakeup_locked(last->inp_socket);
 2115                 INP_RUNLOCK(last);
 2116         } else {
 2117                 m_freem(m);
 2118                 IP6STAT_DEC(ip6s_delivered);
 2119         }
 2120         return IPPROTO_DONE;
 2121 }
 2122 
 2123 /*
 2124  * Reflect the ip6 packet back to the source.
 2125  * OFF points to the icmp6 header, counted from the top of the mbuf.
 2126  */
 2127 void
 2128 icmp6_reflect(struct mbuf *m, size_t off)
 2129 {
 2130         struct ip6_hdr *ip6;
 2131         struct icmp6_hdr *icmp6;
 2132         struct in6_ifaddr *ia = NULL;
 2133         int plen;
 2134         int type, code;
 2135         struct ifnet *outif = NULL;
 2136         struct in6_addr origdst, src, *srcp = NULL;
 2137 
 2138         /* too short to reflect */
 2139         if (off < sizeof(struct ip6_hdr)) {
 2140                 nd6log((LOG_DEBUG,
 2141                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
 2142                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
 2143                     __FILE__, __LINE__));
 2144                 goto bad;
 2145         }
 2146 
 2147         /*
 2148          * If there are extra headers between IPv6 and ICMPv6, strip
 2149          * off that header first.
 2150          */
 2151 #ifdef DIAGNOSTIC
 2152         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
 2153                 panic("assumption failed in icmp6_reflect");
 2154 #endif
 2155         if (off > sizeof(struct ip6_hdr)) {
 2156                 size_t l;
 2157                 struct ip6_hdr nip6;
 2158 
 2159                 l = off - sizeof(struct ip6_hdr);
 2160                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
 2161                 m_adj(m, l);
 2162                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 2163                 if (m->m_len < l) {
 2164                         if ((m = m_pullup(m, l)) == NULL)
 2165                                 return;
 2166                 }
 2167                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
 2168         } else /* off == sizeof(struct ip6_hdr) */ {
 2169                 size_t l;
 2170                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 2171                 if (m->m_len < l) {
 2172                         if ((m = m_pullup(m, l)) == NULL)
 2173                                 return;
 2174                 }
 2175         }
 2176         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
 2177         ip6 = mtod(m, struct ip6_hdr *);
 2178         ip6->ip6_nxt = IPPROTO_ICMPV6;
 2179         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
 2180         type = icmp6->icmp6_type; /* keep type for statistics */
 2181         code = icmp6->icmp6_code; /* ditto. */
 2182 
 2183         origdst = ip6->ip6_dst;
 2184         /*
 2185          * ip6_input() drops a packet if its src is multicast.
 2186          * So, the src is never multicast.
 2187          */
 2188         ip6->ip6_dst = ip6->ip6_src;
 2189 
 2190         /*
 2191          * If the incoming packet was addressed directly to us (i.e. unicast),
 2192          * use dst as the src for the reply.
 2193          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
 2194          * (for example) when we encounter an error while forwarding procedure
 2195          * destined to a duplicated address of ours.
 2196          * Note that ip6_getdstifaddr() may fail if we are in an error handling
 2197          * procedure of an outgoing packet of our own, in which case we need
 2198          * to search in the ifaddr list.
 2199          */
 2200         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
 2201                 if ((ia = ip6_getdstifaddr(m))) {
 2202                         if (!(ia->ia6_flags &
 2203                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
 2204                                 srcp = &ia->ia_addr.sin6_addr;
 2205                 } else {
 2206                         struct sockaddr_in6 d;
 2207 
 2208                         bzero(&d, sizeof(d));
 2209                         d.sin6_family = AF_INET6;
 2210                         d.sin6_len = sizeof(d);
 2211                         d.sin6_addr = origdst;
 2212                         ia = (struct in6_ifaddr *)
 2213                             ifa_ifwithaddr((struct sockaddr *)&d);
 2214                         if (ia &&
 2215                             !(ia->ia6_flags &
 2216                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
 2217                                 srcp = &ia->ia_addr.sin6_addr;
 2218                         }
 2219                 }
 2220         }
 2221 
 2222         if (srcp == NULL) {
 2223                 int e;
 2224                 struct sockaddr_in6 sin6;
 2225                 struct route_in6 ro;
 2226 
 2227                 /*
 2228                  * This case matches to multicasts, our anycast, or unicasts
 2229                  * that we do not own.  Select a source address based on the
 2230                  * source address of the erroneous packet.
 2231                  */
 2232                 bzero(&sin6, sizeof(sin6));
 2233                 sin6.sin6_family = AF_INET6;
 2234                 sin6.sin6_len = sizeof(sin6);
 2235                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
 2236 
 2237                 bzero(&ro, sizeof(ro));
 2238                 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
 2239                 if (ro.ro_rt)
 2240                         RTFREE(ro.ro_rt); /* XXX: we could use this */
 2241                 if (e) {
 2242                         char ip6buf[INET6_ADDRSTRLEN];
 2243                         nd6log((LOG_DEBUG,
 2244                             "icmp6_reflect: source can't be determined: "
 2245                             "dst=%s, error=%d\n",
 2246                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
 2247                         goto bad;
 2248                 }
 2249                 srcp = &src;
 2250         }
 2251 
 2252         ip6->ip6_src = *srcp;
 2253         ip6->ip6_flow = 0;
 2254         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 2255         ip6->ip6_vfc |= IPV6_VERSION;
 2256         ip6->ip6_nxt = IPPROTO_ICMPV6;
 2257         if (outif)
 2258                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
 2259         else if (m->m_pkthdr.rcvif) {
 2260                 /* XXX: This may not be the outgoing interface */
 2261                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
 2262         } else
 2263                 ip6->ip6_hlim = V_ip6_defhlim;
 2264 
 2265         icmp6->icmp6_cksum = 0;
 2266         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
 2267             sizeof(struct ip6_hdr), plen);
 2268 
 2269         /*
 2270          * XXX option handling
 2271          */
 2272 
 2273         m->m_flags &= ~(M_BCAST|M_MCAST);
 2274 
 2275         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
 2276         if (outif)
 2277                 icmp6_ifoutstat_inc(outif, type, code);
 2278 
 2279         if (ia != NULL)
 2280                 ifa_free(&ia->ia_ifa);
 2281         return;
 2282 
 2283  bad:
 2284         if (ia != NULL)
 2285                 ifa_free(&ia->ia_ifa);
 2286         m_freem(m);
 2287         return;
 2288 }
 2289 
 2290 void
 2291 icmp6_fasttimo(void)
 2292 {
 2293 
 2294         mld_fasttimo();
 2295 }
 2296 
 2297 void
 2298 icmp6_slowtimo(void)
 2299 {
 2300 
 2301         mld_slowtimo();
 2302 }
 2303 
 2304 static const char *
 2305 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
 2306     struct in6_addr *tgt6)
 2307 {
 2308         static char buf[1024];
 2309         char ip6bufs[INET6_ADDRSTRLEN];
 2310         char ip6bufd[INET6_ADDRSTRLEN];
 2311         char ip6buft[INET6_ADDRSTRLEN];
 2312         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
 2313             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
 2314             ip6_sprintf(ip6buft, tgt6));
 2315         return buf;
 2316 }
 2317 
 2318 void
 2319 icmp6_redirect_input(struct mbuf *m, int off)
 2320 {
 2321         struct ifnet *ifp;
 2322         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
 2323         struct nd_redirect *nd_rd;
 2324         int icmp6len = ntohs(ip6->ip6_plen);
 2325         char *lladdr = NULL;
 2326         int lladdrlen = 0;
 2327         struct rtentry *rt = NULL;
 2328         int is_router;
 2329         int is_onlink;
 2330         struct in6_addr src6 = ip6->ip6_src;
 2331         struct in6_addr redtgt6;
 2332         struct in6_addr reddst6;
 2333         union nd_opts ndopts;
 2334         char ip6buf[INET6_ADDRSTRLEN];
 2335 
 2336         M_ASSERTPKTHDR(m);
 2337         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
 2338 
 2339         ifp = m->m_pkthdr.rcvif;
 2340 
 2341         /* XXX if we are router, we don't update route by icmp6 redirect */
 2342         if (V_ip6_forwarding)
 2343                 goto freeit;
 2344         if (!V_icmp6_rediraccept)
 2345                 goto freeit;
 2346 
 2347 #ifndef PULLDOWN_TEST
 2348         IP6_EXTHDR_CHECK(m, off, icmp6len,);
 2349         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
 2350 #else
 2351         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
 2352         if (nd_rd == NULL) {
 2353                 ICMP6STAT_INC(icp6s_tooshort);
 2354                 return;
 2355         }
 2356 #endif
 2357         redtgt6 = nd_rd->nd_rd_target;
 2358         reddst6 = nd_rd->nd_rd_dst;
 2359 
 2360         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
 2361             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
 2362                 goto freeit;
 2363         }
 2364 
 2365         /* validation */
 2366         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
 2367                 nd6log((LOG_ERR,
 2368                     "ICMP6 redirect sent from %s rejected; "
 2369                     "must be from linklocal\n",
 2370                     ip6_sprintf(ip6buf, &src6)));
 2371                 goto bad;
 2372         }
 2373         if (ip6->ip6_hlim != 255) {
 2374                 nd6log((LOG_ERR,
 2375                     "ICMP6 redirect sent from %s rejected; "
 2376                     "hlim=%d (must be 255)\n",
 2377                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
 2378                 goto bad;
 2379         }
 2380     {
 2381         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
 2382         struct sockaddr_in6 sin6;
 2383         struct in6_addr *gw6;
 2384 
 2385         bzero(&sin6, sizeof(sin6));
 2386         sin6.sin6_family = AF_INET6;
 2387         sin6.sin6_len = sizeof(struct sockaddr_in6);
 2388         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
 2389         rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB);
 2390         if (rt) {
 2391                 if (rt->rt_gateway == NULL ||
 2392                     rt->rt_gateway->sa_family != AF_INET6) {
 2393                         RTFREE_LOCKED(rt);
 2394                         nd6log((LOG_ERR,
 2395                             "ICMP6 redirect rejected; no route "
 2396                             "with inet6 gateway found for redirect dst: %s\n",
 2397                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2398                         goto bad;
 2399                 }
 2400 
 2401                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
 2402                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
 2403                         RTFREE_LOCKED(rt);
 2404                         nd6log((LOG_ERR,
 2405                             "ICMP6 redirect rejected; "
 2406                             "not equal to gw-for-src=%s (must be same): "
 2407                             "%s\n",
 2408                             ip6_sprintf(ip6buf, gw6),
 2409                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2410                         goto bad;
 2411                 }
 2412         } else {
 2413                 nd6log((LOG_ERR,
 2414                     "ICMP6 redirect rejected; "
 2415                     "no route found for redirect dst: %s\n",
 2416                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2417                 goto bad;
 2418         }
 2419         RTFREE_LOCKED(rt);
 2420         rt = NULL;
 2421     }
 2422         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
 2423                 nd6log((LOG_ERR,
 2424                     "ICMP6 redirect rejected; "
 2425                     "redirect dst must be unicast: %s\n",
 2426                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2427                 goto bad;
 2428         }
 2429 
 2430         is_router = is_onlink = 0;
 2431         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
 2432                 is_router = 1;  /* router case */
 2433         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
 2434                 is_onlink = 1;  /* on-link destination case */
 2435         if (!is_router && !is_onlink) {
 2436                 nd6log((LOG_ERR,
 2437                     "ICMP6 redirect rejected; "
 2438                     "neither router case nor onlink case: %s\n",
 2439                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2440                 goto bad;
 2441         }
 2442         /* validation passed */
 2443 
 2444         icmp6len -= sizeof(*nd_rd);
 2445         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
 2446         if (nd6_options(&ndopts) < 0) {
 2447                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
 2448                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2449                 /* nd6_options have incremented stats */
 2450                 goto freeit;
 2451         }
 2452 
 2453         if (ndopts.nd_opts_tgt_lladdr) {
 2454                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
 2455                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
 2456         }
 2457 
 2458         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
 2459                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
 2460                     "(if %d, icmp6 packet %d): %s\n",
 2461                     __func__, ip6_sprintf(ip6buf, &redtgt6),
 2462                     ifp->if_addrlen, lladdrlen - 2,
 2463                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
 2464                 goto bad;
 2465         }
 2466 
 2467         /* RFC 2461 8.3 */
 2468         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
 2469             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
 2470 
 2471         if (!is_onlink) {       /* better router case.  perform rtredirect. */
 2472                 /* perform rtredirect */
 2473                 struct sockaddr_in6 sdst;
 2474                 struct sockaddr_in6 sgw;
 2475                 struct sockaddr_in6 ssrc;
 2476                 u_int fibnum;
 2477 
 2478                 bzero(&sdst, sizeof(sdst));
 2479                 bzero(&sgw, sizeof(sgw));
 2480                 bzero(&ssrc, sizeof(ssrc));
 2481                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
 2482                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
 2483                         sizeof(struct sockaddr_in6);
 2484                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
 2485                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
 2486                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
 2487                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
 2488                         in6_rtredirect((struct sockaddr *)&sdst,
 2489                             (struct sockaddr *)&sgw, (struct sockaddr *)NULL,
 2490                             RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc,
 2491                             fibnum);
 2492         }
 2493         /* finally update cached route in each socket via pfctlinput */
 2494     {
 2495         struct sockaddr_in6 sdst;
 2496 
 2497         bzero(&sdst, sizeof(sdst));
 2498         sdst.sin6_family = AF_INET6;
 2499         sdst.sin6_len = sizeof(struct sockaddr_in6);
 2500         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
 2501         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
 2502     }
 2503 
 2504  freeit:
 2505         m_freem(m);
 2506         return;
 2507 
 2508  bad:
 2509         ICMP6STAT_INC(icp6s_badredirect);
 2510         m_freem(m);
 2511 }
 2512 
 2513 void
 2514 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
 2515 {
 2516         struct ifnet *ifp;      /* my outgoing interface */
 2517         struct in6_addr *ifp_ll6;
 2518         struct in6_addr *router_ll6;
 2519         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
 2520         struct mbuf *m = NULL;  /* newly allocated one */
 2521         struct m_tag *mtag;
 2522         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
 2523         struct nd_redirect *nd_rd;
 2524         struct llentry *ln = NULL;
 2525         size_t maxlen;
 2526         u_char *p;
 2527         struct ifnet *outif = NULL;
 2528         struct sockaddr_in6 src_sa;
 2529 
 2530         icmp6_errcount(ND_REDIRECT, 0);
 2531 
 2532         /* if we are not router, we don't send icmp6 redirect */
 2533         if (!V_ip6_forwarding)
 2534                 goto fail;
 2535 
 2536         /* sanity check */
 2537         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
 2538                 goto fail;
 2539 
 2540         /*
 2541          * Address check:
 2542          *  the source address must identify a neighbor, and
 2543          *  the destination address must not be a multicast address
 2544          *  [RFC 2461, sec 8.2]
 2545          */
 2546         sip6 = mtod(m0, struct ip6_hdr *);
 2547         bzero(&src_sa, sizeof(src_sa));
 2548         src_sa.sin6_family = AF_INET6;
 2549         src_sa.sin6_len = sizeof(src_sa);
 2550         src_sa.sin6_addr = sip6->ip6_src;
 2551         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
 2552                 goto fail;
 2553         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
 2554                 goto fail;      /* what should we do here? */
 2555 
 2556         /* rate limit */
 2557         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
 2558                 goto fail;
 2559 
 2560         /*
 2561          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
 2562          * we almost always ask for an mbuf cluster for simplicity.
 2563          * (MHLEN < IPV6_MMTU is almost always true)
 2564          */
 2565 #if IPV6_MMTU >= MCLBYTES
 2566 # error assumption failed about IPV6_MMTU and MCLBYTES
 2567 #endif
 2568         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
 2569         if (m == NULL)
 2570                 goto fail;
 2571         M_SETFIB(m, rt->rt_fibnum);
 2572         maxlen = M_TRAILINGSPACE(m);
 2573         maxlen = min(IPV6_MMTU, maxlen);
 2574         /* just for safety */
 2575         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
 2576             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
 2577                 goto fail;
 2578         }
 2579 
 2580         {
 2581                 /* get ip6 linklocal address for ifp(my outgoing interface). */
 2582                 struct in6_ifaddr *ia;
 2583                 if ((ia = in6ifa_ifpforlinklocal(ifp,
 2584                                                  IN6_IFF_NOTREADY|
 2585                                                  IN6_IFF_ANYCAST)) == NULL)
 2586                         goto fail;
 2587                 ifp_ll6 = &ia->ia_addr.sin6_addr;
 2588                 /* XXXRW: reference released prematurely. */
 2589                 ifa_free(&ia->ia_ifa);
 2590         }
 2591 
 2592         /* get ip6 linklocal address for the router. */
 2593         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
 2594                 struct sockaddr_in6 *sin6;
 2595                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
 2596                 router_ll6 = &sin6->sin6_addr;
 2597                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
 2598                         router_ll6 = (struct in6_addr *)NULL;
 2599         } else
 2600                 router_ll6 = (struct in6_addr *)NULL;
 2601 
 2602         /* ip6 */
 2603         ip6 = mtod(m, struct ip6_hdr *);
 2604         ip6->ip6_flow = 0;
 2605         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
 2606         ip6->ip6_vfc |= IPV6_VERSION;
 2607         /* ip6->ip6_plen will be set later */
 2608         ip6->ip6_nxt = IPPROTO_ICMPV6;
 2609         ip6->ip6_hlim = 255;
 2610         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
 2611         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
 2612         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
 2613 
 2614         /* ND Redirect */
 2615         nd_rd = (struct nd_redirect *)(ip6 + 1);
 2616         nd_rd->nd_rd_type = ND_REDIRECT;
 2617         nd_rd->nd_rd_code = 0;
 2618         nd_rd->nd_rd_reserved = 0;
 2619         if (rt->rt_flags & RTF_GATEWAY) {
 2620                 /*
 2621                  * nd_rd->nd_rd_target must be a link-local address in
 2622                  * better router cases.
 2623                  */
 2624                 if (!router_ll6)
 2625                         goto fail;
 2626                 bcopy(router_ll6, &nd_rd->nd_rd_target,
 2627                     sizeof(nd_rd->nd_rd_target));
 2628                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
 2629                     sizeof(nd_rd->nd_rd_dst));
 2630         } else {
 2631                 /* make sure redtgt == reddst */
 2632                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
 2633                     sizeof(nd_rd->nd_rd_target));
 2634                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
 2635                     sizeof(nd_rd->nd_rd_dst));
 2636         }
 2637 
 2638         p = (u_char *)(nd_rd + 1);
 2639 
 2640         if (!router_ll6)
 2641                 goto nolladdropt;
 2642 
 2643         {
 2644                 /* target lladdr option */
 2645                 int len;
 2646                 struct nd_opt_hdr *nd_opt;
 2647                 char *lladdr;
 2648 
 2649                 IF_AFDATA_RLOCK(ifp);
 2650                 ln = nd6_lookup(router_ll6, 0, ifp);
 2651                 IF_AFDATA_RUNLOCK(ifp);
 2652                 if (ln == NULL)
 2653                         goto nolladdropt;
 2654 
 2655                 len = sizeof(*nd_opt) + ifp->if_addrlen;
 2656                 len = (len + 7) & ~7;   /* round by 8 */
 2657                 /* safety check */
 2658                 if (len + (p - (u_char *)ip6) > maxlen)                         
 2659                         goto nolladdropt;
 2660 
 2661                 if (ln->la_flags & LLE_VALID) {
 2662                         nd_opt = (struct nd_opt_hdr *)p;
 2663                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
 2664                         nd_opt->nd_opt_len = len >> 3;
 2665                         lladdr = (char *)(nd_opt + 1);
 2666                         bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
 2667                         p += len;
 2668                 }
 2669         }
 2670 nolladdropt:
 2671         if (ln != NULL)
 2672                 LLE_RUNLOCK(ln);
 2673                 
 2674         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
 2675 
 2676         /* just to be safe */
 2677 #ifdef M_DECRYPTED      /*not openbsd*/
 2678         if (m0->m_flags & M_DECRYPTED)
 2679                 goto noredhdropt;
 2680 #endif
 2681         if (p - (u_char *)ip6 > maxlen)
 2682                 goto noredhdropt;
 2683 
 2684         {
 2685                 /* redirected header option */
 2686                 int len;
 2687                 struct nd_opt_rd_hdr *nd_opt_rh;
 2688 
 2689                 /*
 2690                  * compute the maximum size for icmp6 redirect header option.
 2691                  * XXX room for auth header?
 2692                  */
 2693                 len = maxlen - (p - (u_char *)ip6);
 2694                 len &= ~7;
 2695 
 2696                 /* This is just for simplicity. */
 2697                 if (m0->m_pkthdr.len != m0->m_len) {
 2698                         if (m0->m_next) {
 2699                                 m_freem(m0->m_next);
 2700                                 m0->m_next = NULL;
 2701                         }
 2702                         m0->m_pkthdr.len = m0->m_len;
 2703                 }
 2704 
 2705                 /*
 2706                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
 2707                  * about padding/truncate rule for the original IP packet.
 2708                  * From the discussion on IPv6imp in Feb 1999,
 2709                  * the consensus was:
 2710                  * - "attach as much as possible" is the goal
 2711                  * - pad if not aligned (original size can be guessed by
 2712                  *   original ip6 header)
 2713                  * Following code adds the padding if it is simple enough,
 2714                  * and truncates if not.
 2715                  */
 2716                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
 2717                         panic("assumption failed in %s:%d", __FILE__,
 2718                             __LINE__);
 2719 
 2720                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
 2721                         /* not enough room, truncate */
 2722                         m0->m_pkthdr.len = m0->m_len = len -
 2723                             sizeof(*nd_opt_rh);
 2724                 } else {
 2725                         /* enough room, pad or truncate */
 2726                         size_t extra;
 2727 
 2728                         extra = m0->m_pkthdr.len % 8;
 2729                         if (extra) {
 2730                                 /* pad if easy enough, truncate if not */
 2731                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
 2732                                         /* pad */
 2733                                         m0->m_len += (8 - extra);
 2734                                         m0->m_pkthdr.len += (8 - extra);
 2735                                 } else {
 2736                                         /* truncate */
 2737                                         m0->m_pkthdr.len -= extra;
 2738                                         m0->m_len -= extra;
 2739                                 }
 2740                         }
 2741                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
 2742                         m0->m_pkthdr.len = m0->m_len = len -
 2743                             sizeof(*nd_opt_rh);
 2744                 }
 2745 
 2746                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
 2747                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
 2748                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
 2749                 nd_opt_rh->nd_opt_rh_len = len >> 3;
 2750                 p += sizeof(*nd_opt_rh);
 2751                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
 2752 
 2753                 /* connect m0 to m */
 2754                 m_tag_delete_chain(m0, NULL);
 2755                 m0->m_flags &= ~M_PKTHDR;
 2756                 m->m_next = m0;
 2757                 m->m_pkthdr.len = m->m_len + m0->m_len;
 2758                 m0 = NULL;
 2759         }
 2760 noredhdropt:;
 2761         if (m0) {
 2762                 m_freem(m0);
 2763                 m0 = NULL;
 2764         }
 2765 
 2766         /* XXX: clear embedded link IDs in the inner header */
 2767         in6_clearscope(&sip6->ip6_src);
 2768         in6_clearscope(&sip6->ip6_dst);
 2769         in6_clearscope(&nd_rd->nd_rd_target);
 2770         in6_clearscope(&nd_rd->nd_rd_dst);
 2771 
 2772         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
 2773 
 2774         nd_rd->nd_rd_cksum = 0;
 2775         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
 2776             sizeof(*ip6), ntohs(ip6->ip6_plen));
 2777 
 2778         if (send_sendso_input_hook != NULL) {
 2779                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
 2780                         M_NOWAIT);
 2781                 if (mtag == NULL)
 2782                         goto fail;
 2783                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
 2784                 m_tag_prepend(m, mtag);
 2785         }
 2786 
 2787         /* send the packet to outside... */
 2788         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
 2789         if (outif) {
 2790                 icmp6_ifstat_inc(outif, ifs6_out_msg);
 2791                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
 2792         }
 2793         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
 2794 
 2795         return;
 2796 
 2797 fail:
 2798         if (m)
 2799                 m_freem(m);
 2800         if (m0)
 2801                 m_freem(m0);
 2802 }
 2803 
 2804 /*
 2805  * ICMPv6 socket option processing.
 2806  */
 2807 int
 2808 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
 2809 {
 2810         int error = 0;
 2811         int optlen;
 2812         struct inpcb *inp = sotoinpcb(so);
 2813         int level, op, optname;
 2814 
 2815         if (sopt) {
 2816                 level = sopt->sopt_level;
 2817                 op = sopt->sopt_dir;
 2818                 optname = sopt->sopt_name;
 2819                 optlen = sopt->sopt_valsize;
 2820         } else
 2821                 level = op = optname = optlen = 0;
 2822 
 2823         if (level != IPPROTO_ICMPV6) {
 2824                 return EINVAL;
 2825         }
 2826 
 2827         switch (op) {
 2828         case PRCO_SETOPT:
 2829                 switch (optname) {
 2830                 case ICMP6_FILTER:
 2831                     {
 2832                         struct icmp6_filter ic6f;
 2833 
 2834                         if (optlen != sizeof(ic6f)) {
 2835                                 error = EMSGSIZE;
 2836                                 break;
 2837                         }
 2838                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
 2839                         if (error == 0) {
 2840                                 INP_WLOCK(inp);
 2841                                 *inp->in6p_icmp6filt = ic6f;
 2842                                 INP_WUNLOCK(inp);
 2843                         }
 2844                         break;
 2845                     }
 2846 
 2847                 default:
 2848                         error = ENOPROTOOPT;
 2849                         break;
 2850                 }
 2851                 break;
 2852 
 2853         case PRCO_GETOPT:
 2854                 switch (optname) {
 2855                 case ICMP6_FILTER:
 2856                     {
 2857                         struct icmp6_filter ic6f;
 2858 
 2859                         INP_RLOCK(inp);
 2860                         ic6f = *inp->in6p_icmp6filt;
 2861                         INP_RUNLOCK(inp);
 2862                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
 2863                         break;
 2864                     }
 2865 
 2866                 default:
 2867                         error = ENOPROTOOPT;
 2868                         break;
 2869                 }
 2870                 break;
 2871         }
 2872 
 2873         return (error);
 2874 }
 2875 
 2876 /*
 2877  * Perform rate limit check.
 2878  * Returns 0 if it is okay to send the icmp6 packet.
 2879  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
 2880  * limitation.
 2881  *
 2882  * XXX per-destination/type check necessary?
 2883  *
 2884  * dst - not used at this moment
 2885  * type - not used at this moment
 2886  * code - not used at this moment
 2887  */
 2888 static int
 2889 icmp6_ratelimit(const struct in6_addr *dst, const int type,
 2890     const int code)
 2891 {
 2892         int ret;
 2893 
 2894         ret = 0;        /* okay to send */
 2895 
 2896         /* PPS limit */
 2897         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
 2898             V_icmp6errppslim)) {
 2899                 /* The packet is subject to rate limit */
 2900                 ret++;
 2901         }
 2902 
 2903         return ret;
 2904 }

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