sys/netinet6/icmp6.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #define MBUF_PRIVATE    /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70
  71 #include <sys/param.h>
  72 #include <sys/domain.h>
  73 #include <sys/jail.h>
  74 #include <sys/kernel.h>
  75 #include <sys/lock.h>
  76 #include <sys/malloc.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/proc.h>
  79 #include <sys/protosw.h>
  80 #include <sys/signalvar.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #include <sys/sx.h>
  84 #include <sys/syslog.h>
  85 #include <sys/systm.h>
  86 #include <sys/time.h>
  87
  88 #include <net/if.h>
  89 #include <net/if_var.h>
  90 #include <net/if_dl.h>
  91 #include <net/if_llatbl.h>
  92 #include <net/if_types.h>
  93 #include <net/route.h>
  94 #include <net/vnet.h>
  95
  96 #include <netinet/in.h>
  97 #include <netinet/in_pcb.h>
  98 #include <netinet/in_var.h>
  99 #include <netinet/ip6.h>
 100 #include <netinet/icmp6.h>
 101 #include <netinet/tcp_var.h>
 102
 103 #include <netinet6/in6_fib.h>
 104 #include <netinet6/in6_ifattach.h>
 105 #include <netinet6/in6_pcb.h>
 106 #include <netinet6/ip6protosw.h>
 107 #include <netinet6/ip6_var.h>
 108 #include <netinet6/scope6_var.h>
 109 #include <netinet6/mld6_var.h>
 110 #include <netinet6/nd6.h>
 111 #include <netinet6/send.h>
 112
 113 extern struct domain inet6domain;
 114
 115 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
 116 VNET_PCPUSTAT_SYSINIT(icmp6stat);
 117
 118 #ifdef VIMAGE
 119 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
 120 #endif /* VIMAGE */
 121
 122 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 123 VNET_DECLARE(struct inpcbhead, ripcb);
 124 VNET_DECLARE(int, icmp6errppslim);
 125 static VNET_DEFINE(int, icmp6errpps_count) = 0;
 126 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 127 VNET_DECLARE(int, icmp6_nodeinfo);
 128
 129 #define V_ripcbinfo                     VNET(ripcbinfo)
 130 #define V_ripcb                         VNET(ripcb)
 131 #define V_icmp6errppslim                VNET(icmp6errppslim)
 132 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 133 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 134 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 135
 136 static void icmp6_errcount(int, int);
 137 static int icmp6_rip6_input(struct mbuf **, int);
 138 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 139 static const char *icmp6_redirect_diag(struct in6_addr *,
 140         struct in6_addr *, struct in6_addr *);
 141 static struct mbuf *ni6_input(struct mbuf *, int);
 142 static struct mbuf *ni6_nametodns(const char *, int, int);
 143 static int ni6_dnsmatch(const char *, int, const char *, int);
 144 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 145                           struct ifnet **, struct in6_addr *);
 146 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 147                                 struct ifnet *, int);
 148 static int icmp6_notify_error(struct mbuf **, int, int, int);
 149
 150 /*
 151  * Kernel module interface for updating icmp6stat.  The argument is an index
 152  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 153  * general layout of icmp6stat into the caller, it doesn't encode its
 154  * location, so that future changes to add, for example, per-CPU stats
 155  * support won't cause binary compatibility problems for kernel modules.
 156  */
 157 void
 158 kmod_icmp6stat_inc(int statnum)
 159 {
 160
 161         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 162 }
 163
 164 static void
 165 icmp6_errcount(int type, int code)
 166 {
 167         switch (type) {
 168         case ICMP6_DST_UNREACH:
 169                 switch (code) {
 170                 case ICMP6_DST_UNREACH_NOROUTE:
 171                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 172                         return;
 173                 case ICMP6_DST_UNREACH_ADMIN:
 174                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 175                         return;
 176                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 177                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 178                         return;
 179                 case ICMP6_DST_UNREACH_ADDR:
 180                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 181                         return;
 182                 case ICMP6_DST_UNREACH_NOPORT:
 183                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 184                         return;
 185                 }
 186                 break;
 187         case ICMP6_PACKET_TOO_BIG:
 188                 ICMP6STAT_INC(icp6s_opacket_too_big);
 189                 return;
 190         case ICMP6_TIME_EXCEEDED:
 191                 switch (code) {
 192                 case ICMP6_TIME_EXCEED_TRANSIT:
 193                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 194                         return;
 195                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 196                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 197                         return;
 198                 }
 199                 break;
 200         case ICMP6_PARAM_PROB:
 201                 switch (code) {
 202                 case ICMP6_PARAMPROB_HEADER:
 203                         ICMP6STAT_INC(icp6s_oparamprob_header);
 204                         return;
 205                 case ICMP6_PARAMPROB_NEXTHEADER:
 206                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 207                         return;
 208                 case ICMP6_PARAMPROB_OPTION:
 209                         ICMP6STAT_INC(icp6s_oparamprob_option);
 210                         return;
 211                 }
 212                 break;
 213         case ND_REDIRECT:
 214                 ICMP6STAT_INC(icp6s_oredirect);
 215                 return;
 216         }
 217         ICMP6STAT_INC(icp6s_ounknown);
 218 }
 219
 220 /*
 221  * A wrapper function for icmp6_error() necessary when the erroneous packet
 222  * may not contain enough scope zone information.
 223  */
 224 void
 225 icmp6_error2(struct mbuf *m, int type, int code, int param,
 226     struct ifnet *ifp)
 227 {
 228         struct ip6_hdr *ip6;
 229
 230         if (ifp == NULL)
 231                 return;
 232
 233 #ifndef PULLDOWN_TEST
 234         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 235 #else
 236         if (m->m_len < sizeof(struct ip6_hdr)) {
 237                 m = m_pullup(m, sizeof(struct ip6_hdr));
 238                 if (m == NULL)
 239                         return;
 240         }
 241 #endif
 242
 243         ip6 = mtod(m, struct ip6_hdr *);
 244
 245         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 246                 return;
 247         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 248                 return;
 249
 250         icmp6_error(m, type, code, param);
 251 }
 252
 253 /*
 254  * Generate an error packet of type error in response to bad IP6 packet.
 255  */
 256 void
 257 icmp6_error(struct mbuf *m, int type, int code, int param)
 258 {
 259         struct ip6_hdr *oip6, *nip6;
 260         struct icmp6_hdr *icmp6;
 261         u_int preplen;
 262         int off;
 263         int nxt;
 264
 265         ICMP6STAT_INC(icp6s_error);
 266
 267         /* count per-type-code statistics */
 268         icmp6_errcount(type, code);
 269
 270 #ifdef M_DECRYPTED      /*not openbsd*/
 271         if (m->m_flags & M_DECRYPTED) {
 272                 ICMP6STAT_INC(icp6s_canterror);
 273                 goto freeit;
 274         }
 275 #endif
 276
 277 #ifndef PULLDOWN_TEST
 278         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 279 #else
 280         if (m->m_len < sizeof(struct ip6_hdr)) {
 281                 m = m_pullup(m, sizeof(struct ip6_hdr));
 282                 if (m == NULL)
 283                         return;
 284         }
 285 #endif
 286         oip6 = mtod(m, struct ip6_hdr *);
 287
 288         /*
 289          * If the destination address of the erroneous packet is a multicast
 290          * address, or the packet was sent using link-layer multicast,
 291          * we should basically suppress sending an error (RFC 2463, Section
 292          * 2.4).
 293          * We have two exceptions (the item e.2 in that section):
 294          * - the Packet Too Big message can be sent for path MTU discovery.
 295          * - the Parameter Problem Message that can be allowed an icmp6 error
 296          *   in the option type field.  This check has been done in
 297          *   ip6_unknown_opt(), so we can just check the type and code.
 298          */
 299         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 300              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 301             (type != ICMP6_PACKET_TOO_BIG &&
 302              (type != ICMP6_PARAM_PROB ||
 303               code != ICMP6_PARAMPROB_OPTION)))
 304                 goto freeit;
 305
 306         /*
 307          * RFC 2463, 2.4 (e.5): source address check.
 308          * XXX: the case of anycast source?
 309          */
 310         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 311             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 312                 goto freeit;
 313
 314         /*
 315          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 316          * don't do it.
 317          */
 318         nxt = -1;
 319         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 320         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 321                 struct icmp6_hdr *icp;
 322
 323 #ifndef PULLDOWN_TEST
 324                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 325                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 326 #else
 327                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 328                         sizeof(*icp));
 329                 if (icp == NULL) {
 330                         ICMP6STAT_INC(icp6s_tooshort);
 331                         return;
 332                 }
 333 #endif
 334                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 335                     icp->icmp6_type == ND_REDIRECT) {
 336                         /*
 337                          * ICMPv6 error
 338                          * Special case: for redirect (which is
 339                          * informational) we must not send icmp6 error.
 340                          */
 341                         ICMP6STAT_INC(icp6s_canterror);
 342                         goto freeit;
 343                 } else {
 344                         /* ICMPv6 informational - send the error */
 345                 }
 346         } else {
 347                 /* non-ICMPv6 - send the error */
 348         }
 349
 350         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 351
 352         /* Finally, do rate limitation check. */
 353         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 354                 ICMP6STAT_INC(icp6s_toofreq);
 355                 goto freeit;
 356         }
 357
 358         /*
 359          * OK, ICMP6 can be generated.
 360          */
 361
 362         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 363                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 364
 365         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 366         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 367         if (m == NULL) {
 368                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 369                 return;
 370         }
 371
 372         nip6 = mtod(m, struct ip6_hdr *);
 373         nip6->ip6_src  = oip6->ip6_src;
 374         nip6->ip6_dst  = oip6->ip6_dst;
 375
 376         in6_clearscope(&oip6->ip6_src);
 377         in6_clearscope(&oip6->ip6_dst);
 378
 379         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 380         icmp6->icmp6_type = type;
 381         icmp6->icmp6_code = code;
 382         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 383
 384         /*
 385          * icmp6_reflect() is designed to be in the input path.
 386          * icmp6_error() can be called from both input and output path,
 387          * and if we are in output path rcvif could contain bogus value.
 388          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 389          * information in ip header (nip6).
 390          */
 391         m->m_pkthdr.rcvif = NULL;
 392
 393         ICMP6STAT_INC(icp6s_outhist[type]);
 394         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 395
 396         return;
 397
 398   freeit:
 399         /*
 400          * If we can't tell whether or not we can generate ICMP6, free it.
 401          */
 402         m_freem(m);
 403 }
 404
 405 /*
 406  * Process a received ICMP6 message.
 407  */
 408 int
 409 icmp6_input(struct mbuf **mp, int *offp, int proto)
 410 {
 411         struct mbuf *m = *mp, *n;
 412         struct ifnet *ifp;
 413         struct ip6_hdr *ip6, *nip6;
 414         struct icmp6_hdr *icmp6, *nicmp6;
 415         int off = *offp;
 416         int icmp6len = m->m_pkthdr.len - *offp;
 417         int code, sum, noff;
 418         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 419         int ip6len, error;
 420
 421         ifp = m->m_pkthdr.rcvif;
 422
 423 #ifndef PULLDOWN_TEST
 424         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 425         /* m might change if M_LOOP.  So, call mtod after this */
 426 #endif
 427
 428         /*
 429          * Locate icmp6 structure in mbuf, and check
 430          * that not corrupted and of at least minimum length
 431          */
 432
 433         ip6 = mtod(m, struct ip6_hdr *);
 434         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 435         if (icmp6len < sizeof(struct icmp6_hdr)) {
 436                 ICMP6STAT_INC(icp6s_tooshort);
 437                 goto freeit;
 438         }
 439
 440         /*
 441          * Check multicast group membership.
 442          * Note: SSM filters are not applied for ICMPv6 traffic.
 443          */
 444         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 445                 struct in6_multi        *inm;
 446
 447                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 448                 if (inm == NULL) {
 449                         IP6STAT_INC(ip6s_notmember);
 450                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 451                         goto freeit;
 452                 }
 453         }
 454
 455         /*
 456          * calculate the checksum
 457          */
 458 #ifndef PULLDOWN_TEST
 459         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 460 #else
 461         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 462         if (icmp6 == NULL) {
 463                 ICMP6STAT_INC(icp6s_tooshort);
 464                 return IPPROTO_DONE;
 465         }
 466 #endif
 467         code = icmp6->icmp6_code;
 468
 469         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 470                 nd6log((LOG_ERR,
 471                     "ICMP6 checksum error(%d|%x) %s\n",
 472                     icmp6->icmp6_type, sum,
 473                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 474                 ICMP6STAT_INC(icp6s_checksum);
 475                 goto freeit;
 476         }
 477
 478         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 479         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 480         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 481                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 482
 483         switch (icmp6->icmp6_type) {
 484         case ICMP6_DST_UNREACH:
 485                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 486                 switch (code) {
 487                 case ICMP6_DST_UNREACH_NOROUTE:
 488                         code = PRC_UNREACH_NET;
 489                         break;
 490                 case ICMP6_DST_UNREACH_ADMIN:
 491                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 492                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 493                         break;
 494                 case ICMP6_DST_UNREACH_ADDR:
 495                         code = PRC_HOSTDEAD;
 496                         break;
 497                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 498                         /* I mean "source address was incorrect." */
 499                         code = PRC_PARAMPROB;
 500                         break;
 501                 case ICMP6_DST_UNREACH_NOPORT:
 502                         code = PRC_UNREACH_PORT;
 503                         break;
 504                 default:
 505                         goto badcode;
 506                 }
 507                 goto deliver;
 508                 break;
 509
 510         case ICMP6_PACKET_TOO_BIG:
 511                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 512
 513                 /* validation is made in icmp6_mtudisc_update */
 514
 515                 code = PRC_MSGSIZE;
 516
 517                 /*
 518                  * Updating the path MTU will be done after examining
 519                  * intermediate extension headers.
 520                  */
 521                 goto deliver;
 522                 break;
 523
 524         case ICMP6_TIME_EXCEEDED:
 525                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 526                 switch (code) {
 527                 case ICMP6_TIME_EXCEED_TRANSIT:
 528                         code = PRC_TIMXCEED_INTRANS;
 529                         break;
 530                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 531                         code = PRC_TIMXCEED_REASS;
 532                         break;
 533                 default:
 534                         goto badcode;
 535                 }
 536                 goto deliver;
 537                 break;
 538
 539         case ICMP6_PARAM_PROB:
 540                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 541                 switch (code) {
 542                 case ICMP6_PARAMPROB_NEXTHEADER:
 543                         code = PRC_UNREACH_PROTOCOL;
 544                         break;
 545                 case ICMP6_PARAMPROB_HEADER:
 546                 case ICMP6_PARAMPROB_OPTION:
 547                         code = PRC_PARAMPROB;
 548                         break;
 549                 default:
 550                         goto badcode;
 551                 }
 552                 goto deliver;
 553                 break;
 554
 555         case ICMP6_ECHO_REQUEST:
 556                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 557                 if (code != 0)
 558                         goto badcode;
 559                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 560                         /* Give up remote */
 561                         break;
 562                 }
 563                 if (!M_WRITABLE(n)
 564                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 565                         struct mbuf *n0 = n;
 566                         int n0len;
 567
 568                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 569                         n = m_gethdr(M_NOWAIT, n0->m_type);
 570                         if (n == NULL) {
 571                                 /* Give up remote */
 572                                 m_freem(n0);
 573                                 break;
 574                         }
 575
 576                         m_move_pkthdr(n, n0);   /* FIB copied. */
 577                         n0len = n0->m_pkthdr.len;       /* save for use below */
 578                         /*
 579                          * Copy IPv6 and ICMPv6 only.
 580                          */
 581                         nip6 = mtod(n, struct ip6_hdr *);
 582                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 583                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 584                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 585                         noff = sizeof(struct ip6_hdr);
 586                         /* new mbuf contains only ipv6+icmpv6 headers */
 587                         n->m_len = noff + sizeof(struct icmp6_hdr);
 588                         /*
 589                          * Adjust mbuf.  ip6_plen will be adjusted in
 590                          * ip6_output().
 591                          */
 592                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 593                         /* recalculate complete packet size */
 594                         n->m_pkthdr.len = n0len + (noff - off);
 595                         n->m_next = n0;
 596                 } else {
 597                         nip6 = mtod(n, struct ip6_hdr *);
 598                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 599                             sizeof(*nicmp6));
 600                         noff = off;
 601                 }
 602                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 603                 nicmp6->icmp6_code = 0;
 604                 if (n) {
 605                         ICMP6STAT_INC(icp6s_reflect);
 606                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 607                         icmp6_reflect(n, noff);
 608                 }
 609                 break;
 610
 611         case ICMP6_ECHO_REPLY:
 612                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 613                 if (code != 0)
 614                         goto badcode;
 615                 break;
 616
 617         case MLD_LISTENER_QUERY:
 618         case MLD_LISTENER_REPORT:
 619         case MLD_LISTENER_DONE:
 620         case MLDV2_LISTENER_REPORT:
 621                 /*
 622                  * Drop MLD traffic which is not link-local, has a hop limit
 623                  * of greater than 1 hop, or which does not have the
 624                  * IPv6 HBH Router Alert option.
 625                  * As IPv6 HBH options are stripped in ip6_input() we must
 626                  * check an mbuf header flag.
 627                  * XXX Should we also sanity check that these messages
 628                  * were directed to a link-local multicast prefix?
 629                  */
 630                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 631                         goto freeit;
 632                 if (mld_input(m, off, icmp6len) != 0)
 633                         return (IPPROTO_DONE);
 634                 /* m stays. */
 635                 break;
 636
 637         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 638             {
 639                 enum { WRU, FQDN } mode;
 640
 641                 if (!V_icmp6_nodeinfo)
 642                         break;
 643
 644                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 645                         mode = WRU;
 646                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 647                         mode = FQDN;
 648                 else
 649                         goto badlen;
 650
 651                 if (mode == FQDN) {
 652 #ifndef PULLDOWN_TEST
 653                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 654                             IPPROTO_DONE);
 655 #endif
 656                         n = m_copy(m, 0, M_COPYALL);
 657                         if (n)
 658                                 n = ni6_input(n, off);
 659                         /* XXX meaningless if n == NULL */
 660                         noff = sizeof(struct ip6_hdr);
 661                 } else {
 662                         struct prison *pr;
 663                         u_char *p;
 664                         int maxhlen, hlen;
 665
 666                         /*
 667                          * XXX: this combination of flags is pointless,
 668                          * but should we keep this for compatibility?
 669                          */
 670                         if ((V_icmp6_nodeinfo & 5) != 5)
 671                                 break;
 672
 673                         if (code != 0)
 674                                 goto badcode;
 675
 676                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 677                         n = m_gethdr(M_NOWAIT, m->m_type);
 678                         if (n == NULL) {
 679                                 /* Give up remote */
 680                                 break;
 681                         }
 682                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 683                                 /*
 684                                  * Previous code did a blind M_COPY_PKTHDR
 685                                  * and said "just for rcvif".  If true, then
 686                                  * we could tolerate the dup failing (due to
 687                                  * the deep copy of the tag chain).  For now
 688                                  * be conservative and just fail.
 689                                  */
 690                                 m_free(n);
 691                                 n = NULL;
 692                         }
 693                         maxhlen = M_TRAILINGSPACE(n) -
 694                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 695                         pr = curthread->td_ucred->cr_prison;
 696                         mtx_lock(&pr->pr_mtx);
 697                         hlen = strlen(pr->pr_hostname);
 698                         if (maxhlen > hlen)
 699                                 maxhlen = hlen;
 700                         /*
 701                          * Copy IPv6 and ICMPv6 only.
 702                          */
 703                         nip6 = mtod(n, struct ip6_hdr *);
 704                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 705                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 706                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 707                         p = (u_char *)(nicmp6 + 1);
 708                         bzero(p, 4);
 709                         /* meaningless TTL */
 710                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 711                         mtx_unlock(&pr->pr_mtx);
 712                         noff = sizeof(struct ip6_hdr);
 713                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 714                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 715                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 716                         nicmp6->icmp6_code = 0;
 717                 }
 718                 if (n) {
 719                         ICMP6STAT_INC(icp6s_reflect);
 720                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 721                         icmp6_reflect(n, noff);
 722                 }
 723                 break;
 724             }
 725
 726         case ICMP6_WRUREPLY:
 727                 if (code != 0)
 728                         goto badcode;
 729                 break;
 730
 731         case ND_ROUTER_SOLICIT:
 732                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 733                 if (code != 0)
 734                         goto badcode;
 735                 if (icmp6len < sizeof(struct nd_router_solicit))
 736                         goto badlen;
 737                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 738                         /* give up local */
 739
 740                         /* Send incoming SeND packet to user space. */
 741                         if (send_sendso_input_hook != NULL) {
 742                                 IP6_EXTHDR_CHECK(m, off,
 743                                     icmp6len, IPPROTO_DONE);
 744                                 error = send_sendso_input_hook(m, ifp,
 745                                     SND_IN, ip6len);
 746                                 /* -1 == no app on SEND socket */
 747                                 if (error == 0)
 748                                         return (IPPROTO_DONE);
 749                                 nd6_rs_input(m, off, icmp6len);
 750                         } else
 751                                 nd6_rs_input(m, off, icmp6len);
 752                         m = NULL;
 753                         goto freeit;
 754                 }
 755                 if (send_sendso_input_hook != NULL) {
 756                         IP6_EXTHDR_CHECK(n, off,
 757                             icmp6len, IPPROTO_DONE);
 758                         error = send_sendso_input_hook(n, ifp,
 759                             SND_IN, ip6len);
 760                         if (error == 0)
 761                                 goto freeit;
 762                         /* -1 == no app on SEND socket */
 763                         nd6_rs_input(n, off, icmp6len);
 764                 } else
 765                         nd6_rs_input(n, off, icmp6len);
 766                 /* m stays. */
 767                 break;
 768
 769         case ND_ROUTER_ADVERT:
 770                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 771                 if (code != 0)
 772                         goto badcode;
 773                 if (icmp6len < sizeof(struct nd_router_advert))
 774                         goto badlen;
 775                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 776
 777                         /* Send incoming SeND-protected/ND packet to user space. */
 778                         if (send_sendso_input_hook != NULL) {
 779                                 error = send_sendso_input_hook(m, ifp,
 780                                     SND_IN, ip6len);
 781                                 if (error == 0)
 782                                         return (IPPROTO_DONE);
 783                                 nd6_ra_input(m, off, icmp6len);
 784                         } else
 785                                 nd6_ra_input(m, off, icmp6len);
 786                         m = NULL;
 787                         goto freeit;
 788                 }
 789                 if (send_sendso_input_hook != NULL) {
 790                         error = send_sendso_input_hook(n, ifp,
 791                             SND_IN, ip6len);
 792                         if (error == 0)
 793                                 goto freeit;
 794                         nd6_ra_input(n, off, icmp6len);
 795                 } else
 796                         nd6_ra_input(n, off, icmp6len);
 797                 /* m stays. */
 798                 break;
 799
 800         case ND_NEIGHBOR_SOLICIT:
 801                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 802                 if (code != 0)
 803                         goto badcode;
 804                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 805                         goto badlen;
 806                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 807                         if (send_sendso_input_hook != NULL) {
 808                                 error = send_sendso_input_hook(m, ifp,
 809                                     SND_IN, ip6len);
 810                                 if (error == 0)
 811                                         return (IPPROTO_DONE);
 812                                 nd6_ns_input(m, off, icmp6len);
 813                         } else
 814                                 nd6_ns_input(m, off, icmp6len);
 815                         m = NULL;
 816                         goto freeit;
 817                 }
 818                 if (send_sendso_input_hook != NULL) {
 819                         error = send_sendso_input_hook(n, ifp,
 820                             SND_IN, ip6len);
 821                         if (error == 0)
 822                                 goto freeit;
 823                         nd6_ns_input(n, off, icmp6len);
 824                 } else
 825                         nd6_ns_input(n, off, icmp6len);
 826                 /* m stays. */
 827                 break;
 828
 829         case ND_NEIGHBOR_ADVERT:
 830                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 831                 if (code != 0)
 832                         goto badcode;
 833                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 834                         goto badlen;
 835                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 836
 837                         /* Send incoming SeND-protected/ND packet to user space. */
 838                         if (send_sendso_input_hook != NULL) {
 839                                 error = send_sendso_input_hook(m, ifp,
 840                                     SND_IN, ip6len);
 841                                 if (error == 0)
 842                                         return (IPPROTO_DONE);
 843                                 nd6_na_input(m, off, icmp6len);
 844                         } else
 845                                 nd6_na_input(m, off, icmp6len);
 846                         m = NULL;
 847                         goto freeit;
 848                 }
 849                 if (send_sendso_input_hook != NULL) {
 850                         error = send_sendso_input_hook(n, ifp,
 851                             SND_IN, ip6len);
 852                         if (error == 0)
 853                                 goto freeit;
 854                         nd6_na_input(n, off, icmp6len);
 855                 } else
 856                         nd6_na_input(n, off, icmp6len);
 857                 /* m stays. */
 858                 break;
 859
 860         case ND_REDIRECT:
 861                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 862                 if (code != 0)
 863                         goto badcode;
 864                 if (icmp6len < sizeof(struct nd_redirect))
 865                         goto badlen;
 866                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 867                         if (send_sendso_input_hook != NULL) {
 868                                 error = send_sendso_input_hook(m, ifp,
 869                                     SND_IN, ip6len);
 870                                 if (error == 0)
 871                                         return (IPPROTO_DONE);
 872                             icmp6_redirect_input(m, off);
 873                         } else
 874                                 icmp6_redirect_input(m, off);
 875                         m = NULL;
 876                         goto freeit;
 877                 }
 878                 if (send_sendso_input_hook != NULL) {
 879                         error = send_sendso_input_hook(n, ifp,
 880                             SND_IN, ip6len);
 881                         if (error == 0)
 882                                 goto freeit;
 883                         icmp6_redirect_input(n, off);
 884                 } else
 885                         icmp6_redirect_input(n, off);
 886                 /* m stays. */
 887                 break;
 888
 889         case ICMP6_ROUTER_RENUMBERING:
 890                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 891                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 892                         goto badcode;
 893                 if (icmp6len < sizeof(struct icmp6_router_renum))
 894                         goto badlen;
 895                 break;
 896
 897         default:
 898                 nd6log((LOG_DEBUG,
 899                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 900                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 901                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 902                     ifp ? ifp->if_index : 0));
 903                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 904                         /* ICMPv6 error: MUST deliver it by spec... */
 905                         code = PRC_NCMDS;
 906                         /* deliver */
 907                 } else {
 908                         /* ICMPv6 informational: MUST not deliver */
 909                         break;
 910                 }
 911         deliver:
 912                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 913                         /* In this case, m should've been freed. */
 914                         return (IPPROTO_DONE);
 915                 }
 916                 break;
 917
 918         badcode:
 919                 ICMP6STAT_INC(icp6s_badcode);
 920                 break;
 921
 922         badlen:
 923                 ICMP6STAT_INC(icp6s_badlen);
 924                 break;
 925         }
 926
 927         /* deliver the packet to appropriate sockets */
 928         icmp6_rip6_input(&m, *offp);
 929
 930         return IPPROTO_DONE;
 931
 932  freeit:
 933         m_freem(m);
 934         return IPPROTO_DONE;
 935 }
 936
 937 static int
 938 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 939 {
 940         struct mbuf *m = *mp;
 941         struct icmp6_hdr *icmp6;
 942         struct ip6_hdr *eip6;
 943         u_int32_t notifymtu;
 944         struct sockaddr_in6 icmp6src, icmp6dst;
 945
 946         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 947                 ICMP6STAT_INC(icp6s_tooshort);
 948                 goto freeit;
 949         }
 950 #ifndef PULLDOWN_TEST
 951         IP6_EXTHDR_CHECK(m, off,
 952             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 953         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 954 #else
 955         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 956             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 957         if (icmp6 == NULL) {
 958                 ICMP6STAT_INC(icp6s_tooshort);
 959                 return (-1);
 960         }
 961 #endif
 962         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 963
 964         /* Detect the upper level protocol */
 965         {
 966                 void (*ctlfunc)(int, struct sockaddr *, void *);
 967                 u_int8_t nxt = eip6->ip6_nxt;
 968                 int eoff = off + sizeof(struct icmp6_hdr) +
 969                     sizeof(struct ip6_hdr);
 970                 struct ip6ctlparam ip6cp;
 971                 struct in6_addr *finaldst = NULL;
 972                 int icmp6type = icmp6->icmp6_type;
 973                 struct ip6_frag *fh;
 974                 struct ip6_rthdr *rth;
 975                 struct ip6_rthdr0 *rth0;
 976                 int rthlen;
 977
 978                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 979                         struct ip6_ext *eh;
 980
 981                         switch (nxt) {
 982                         case IPPROTO_HOPOPTS:
 983                         case IPPROTO_DSTOPTS:
 984                         case IPPROTO_AH:
 985 #ifndef PULLDOWN_TEST
 986                                 IP6_EXTHDR_CHECK(m, 0,
 987                                     eoff + sizeof(struct ip6_ext), -1);
 988                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 989 #else
 990                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 991                                     eoff, sizeof(*eh));
 992                                 if (eh == NULL) {
 993                                         ICMP6STAT_INC(icp6s_tooshort);
 994                                         return (-1);
 995                                 }
 996 #endif
 997
 998                                 if (nxt == IPPROTO_AH)
 999                                         eoff += (eh->ip6e_len + 2) << 2;
1000                                 else
1001                                         eoff += (eh->ip6e_len + 1) << 3;
1002                                 nxt = eh->ip6e_nxt;
1003                                 break;
1004                         case IPPROTO_ROUTING:
1005                                 /*
1006                                  * When the erroneous packet contains a
1007                                  * routing header, we should examine the
1008                                  * header to determine the final destination.
1009                                  * Otherwise, we can't properly update
1010                                  * information that depends on the final
1011                                  * destination (e.g. path MTU).
1012                                  */
1013 #ifndef PULLDOWN_TEST
1014                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1015                                 rth = (struct ip6_rthdr *)
1016                                     (mtod(m, caddr_t) + eoff);
1017 #else
1018                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1019                                     eoff, sizeof(*rth));
1020                                 if (rth == NULL) {
1021                                         ICMP6STAT_INC(icp6s_tooshort);
1022                                         return (-1);
1023                                 }
1024 #endif
1025                                 rthlen = (rth->ip6r_len + 1) << 3;
1026                                 /*
1027                                  * XXX: currently there is no
1028                                  * officially defined type other
1029                                  * than type-0.
1030                                  * Note that if the segment left field
1031                                  * is 0, all intermediate hops must
1032                                  * have been passed.
1033                                  */
1034                                 if (rth->ip6r_segleft &&
1035                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1036                                         int hops;
1037
1038 #ifndef PULLDOWN_TEST
1039                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1040                                         rth0 = (struct ip6_rthdr0 *)
1041                                             (mtod(m, caddr_t) + eoff);
1042 #else
1043                                         IP6_EXTHDR_GET(rth0,
1044                                             struct ip6_rthdr0 *, m,
1045                                             eoff, rthlen);
1046                                         if (rth0 == NULL) {
1047                                                 ICMP6STAT_INC(icp6s_tooshort);
1048                                                 return (-1);
1049                                         }
1050 #endif
1051                                         /* just ignore a bogus header */
1052                                         if ((rth0->ip6r0_len % 2) == 0 &&
1053                                             (hops = rth0->ip6r0_len/2))
1054                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1055                                 }
1056                                 eoff += rthlen;
1057                                 nxt = rth->ip6r_nxt;
1058                                 break;
1059                         case IPPROTO_FRAGMENT:
1060 #ifndef PULLDOWN_TEST
1061                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1062                                     sizeof(struct ip6_frag), -1);
1063                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1064                                     eoff);
1065 #else
1066                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1067                                     eoff, sizeof(*fh));
1068                                 if (fh == NULL) {
1069                                         ICMP6STAT_INC(icp6s_tooshort);
1070                                         return (-1);
1071                                 }
1072 #endif
1073                                 /*
1074                                  * Data after a fragment header is meaningless
1075                                  * unless it is the first fragment, but
1076                                  * we'll go to the notify label for path MTU
1077                                  * discovery.
1078                                  */
1079                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1080                                         goto notify;
1081
1082                                 eoff += sizeof(struct ip6_frag);
1083                                 nxt = fh->ip6f_nxt;
1084                                 break;
1085                         default:
1086                                 /*
1087                                  * This case includes ESP and the No Next
1088                                  * Header.  In such cases going to the notify
1089                                  * label does not have any meaning
1090                                  * (i.e. ctlfunc will be NULL), but we go
1091                                  * anyway since we might have to update
1092                                  * path MTU information.
1093                                  */
1094                                 goto notify;
1095                         }
1096                 }
1097           notify:
1098 #ifndef PULLDOWN_TEST
1099                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1100 #else
1101                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1102                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1103                 if (icmp6 == NULL) {
1104                         ICMP6STAT_INC(icp6s_tooshort);
1105                         return (-1);
1106                 }
1107 #endif
1108
1109                 /*
1110                  * retrieve parameters from the inner IPv6 header, and convert
1111                  * them into sockaddr structures.
1112                  * XXX: there is no guarantee that the source or destination
1113                  * addresses of the inner packet are in the same scope as
1114                  * the addresses of the icmp packet.  But there is no other
1115                  * way to determine the zone.
1116                  */
1117                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1118
1119                 bzero(&icmp6dst, sizeof(icmp6dst));
1120                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1121                 icmp6dst.sin6_family = AF_INET6;
1122                 if (finaldst == NULL)
1123                         icmp6dst.sin6_addr = eip6->ip6_dst;
1124                 else
1125                         icmp6dst.sin6_addr = *finaldst;
1126                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1127                         goto freeit;
1128                 bzero(&icmp6src, sizeof(icmp6src));
1129                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1130                 icmp6src.sin6_family = AF_INET6;
1131                 icmp6src.sin6_addr = eip6->ip6_src;
1132                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1133                         goto freeit;
1134                 icmp6src.sin6_flowinfo =
1135                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1136
1137                 if (finaldst == NULL)
1138                         finaldst = &eip6->ip6_dst;
1139                 ip6cp.ip6c_m = m;
1140                 ip6cp.ip6c_icmp6 = icmp6;
1141                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1142                 ip6cp.ip6c_off = eoff;
1143                 ip6cp.ip6c_finaldst = finaldst;
1144                 ip6cp.ip6c_src = &icmp6src;
1145                 ip6cp.ip6c_nxt = nxt;
1146
1147                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1148                         notifymtu = ntohl(icmp6->icmp6_mtu);
1149                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1150                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1151                 }
1152
1153                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1154                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1155                 if (ctlfunc) {
1156                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1157                             &ip6cp);
1158                 }
1159         }
1160         *mp = m;
1161         return (0);
1162
1163   freeit:
1164         m_freem(m);
1165         return (-1);
1166 }
1167
1168 void
1169 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1170 {
1171         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1172         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1173         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1174         u_int mtu = ntohl(icmp6->icmp6_mtu);
1175         struct in_conninfo inc;
1176
1177 #if 0
1178         /*
1179          * RFC2460 section 5, last paragraph.
1180          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1181          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1182          * due to packet translator in the middle.
1183          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1184          * special handling.
1185          */
1186         if (mtu < IPV6_MMTU)
1187                 return;
1188 #endif
1189
1190         /*
1191          * we reject ICMPv6 too big with abnormally small value.
1192          * XXX what is the good definition of "abnormally small"?
1193          */
1194         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1195                 return;
1196
1197         if (!validated)
1198                 return;
1199
1200         /*
1201          * In case the suggested mtu is less than IPV6_MMTU, we
1202          * only need to remember that it was for above mentioned
1203          * "alwaysfrag" case.
1204          * Try to be as close to the spec as possible.
1205          */
1206         if (mtu < IPV6_MMTU)
1207                 mtu = IPV6_MMTU - 8;
1208
1209         bzero(&inc, sizeof(inc));
1210         inc.inc_fibnum = M_GETFIB(m);
1211         inc.inc_flags |= INC_ISIPV6;
1212         inc.inc6_faddr = *dst;
1213         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1214                 return;
1215
1216         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1217                 tcp_hc_updatemtu(&inc, mtu);
1218                 ICMP6STAT_INC(icp6s_pmtuchg);
1219         }
1220 }
1221
1222 /*
1223  * Process a Node Information Query packet, based on
1224  * draft-ietf-ipngwg-icmp-name-lookups-07.
1225  *
1226  * Spec incompatibilities:
1227  * - IPv6 Subject address handling
1228  * - IPv4 Subject address handling support missing
1229  * - Proxy reply (answer even if it's not for me)
1230  * - joins NI group address at in6_ifattach() time only, does not cope
1231  *   with hostname changes by sethostname(3)
1232  */
1233 static struct mbuf *
1234 ni6_input(struct mbuf *m, int off)
1235 {
1236         struct icmp6_nodeinfo *ni6, *nni6;
1237         struct mbuf *n = NULL;
1238         struct prison *pr;
1239         u_int16_t qtype;
1240         int subjlen;
1241         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1242         struct ni_reply_fqdn *fqdn;
1243         int addrs;              /* for NI_QTYPE_NODEADDR */
1244         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1245         struct in6_addr in6_subj; /* subject address */
1246         struct ip6_hdr *ip6;
1247         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1248         char *subj = NULL;
1249         struct in6_ifaddr *ia6 = NULL;
1250
1251         ip6 = mtod(m, struct ip6_hdr *);
1252 #ifndef PULLDOWN_TEST
1253         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1254 #else
1255         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1256         if (ni6 == NULL) {
1257                 /* m is already reclaimed */
1258                 return (NULL);
1259         }
1260 #endif
1261
1262         /*
1263          * Validate IPv6 source address.
1264          * The default configuration MUST be to refuse answering queries from
1265          * global-scope addresses according to RFC4602.
1266          * Notes:
1267          *  - it's not very clear what "refuse" means; this implementation
1268          *    simply drops it.
1269          *  - it's not very easy to identify global-scope (unicast) addresses
1270          *    since there are many prefixes for them.  It should be safer
1271          *    and in practice sufficient to check "all" but loopback and
1272          *    link-local (note that site-local unicast was deprecated and
1273          *    ULA is defined as global scope-wise)
1274          */
1275         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1276             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1277             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1278                 goto bad;
1279
1280         /*
1281          * Validate IPv6 destination address.
1282          *
1283          * The Responder must discard the Query without further processing
1284          * unless it is one of the Responder's unicast or anycast addresses, or
1285          * a link-local scope multicast address which the Responder has joined.
1286          * [RFC4602, Section 5.]
1287          */
1288         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1289                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1290                         goto bad;
1291                 /* else it's a link-local multicast, fine */
1292         } else {                /* unicast or anycast */
1293                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1294                 if (ia6 == NULL)
1295                         goto bad; /* XXX impossible */
1296
1297                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1298                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1299                         ifa_free(&ia6->ia_ifa);
1300                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1301                                 "a temporary address in %s:%d",
1302                                __FILE__, __LINE__));
1303                         goto bad;
1304                 }
1305                 ifa_free(&ia6->ia_ifa);
1306         }
1307
1308         /* validate query Subject field. */
1309         qtype = ntohs(ni6->ni_qtype);
1310         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1311         switch (qtype) {
1312         case NI_QTYPE_NOOP:
1313         case NI_QTYPE_SUPTYPES:
1314                 /* 07 draft */
1315                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1316                         break;
1317                 /* FALLTHROUGH */
1318         case NI_QTYPE_FQDN:
1319         case NI_QTYPE_NODEADDR:
1320         case NI_QTYPE_IPV4ADDR:
1321                 switch (ni6->ni_code) {
1322                 case ICMP6_NI_SUBJ_IPV6:
1323 #if ICMP6_NI_SUBJ_IPV6 != 0
1324                 case 0:
1325 #endif
1326                         /*
1327                          * backward compatibility - try to accept 03 draft
1328                          * format, where no Subject is present.
1329                          */
1330                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1331                             subjlen == 0) {
1332                                 oldfqdn++;
1333                                 break;
1334                         }
1335 #if ICMP6_NI_SUBJ_IPV6 != 0
1336                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1337                                 goto bad;
1338 #endif
1339
1340                         if (subjlen != sizeof(struct in6_addr))
1341                                 goto bad;
1342
1343                         /*
1344                          * Validate Subject address.
1345                          *
1346                          * Not sure what exactly "address belongs to the node"
1347                          * means in the spec, is it just unicast, or what?
1348                          *
1349                          * At this moment we consider Subject address as
1350                          * "belong to the node" if the Subject address equals
1351                          * to the IPv6 destination address; validation for
1352                          * IPv6 destination address should have done enough
1353                          * check for us.
1354                          *
1355                          * We do not do proxy at this moment.
1356                          */
1357                         /* m_pulldown instead of copy? */
1358                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1359                             subjlen, (caddr_t)&in6_subj);
1360                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1361                                 goto bad;
1362
1363                         subj = (char *)&in6_subj;
1364                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1365                                 break;
1366
1367                         /*
1368                          * XXX if we are to allow other cases, we should really
1369                          * be careful about scope here.
1370                          * basically, we should disallow queries toward IPv6
1371                          * destination X with subject Y,
1372                          * if scope(X) > scope(Y).
1373                          * if we allow scope(X) > scope(Y), it will result in
1374                          * information leakage across scope boundary.
1375                          */
1376                         goto bad;
1377
1378                 case ICMP6_NI_SUBJ_FQDN:
1379                         /*
1380                          * Validate Subject name with gethostname(3).
1381                          *
1382                          * The behavior may need some debate, since:
1383                          * - we are not sure if the node has FQDN as
1384                          *   hostname (returned by gethostname(3)).
1385                          * - the code does wildcard match for truncated names.
1386                          *   however, we are not sure if we want to perform
1387                          *   wildcard match, if gethostname(3) side has
1388                          *   truncated hostname.
1389                          */
1390                         pr = curthread->td_ucred->cr_prison;
1391                         mtx_lock(&pr->pr_mtx);
1392                         n = ni6_nametodns(pr->pr_hostname,
1393                             strlen(pr->pr_hostname), 0);
1394                         mtx_unlock(&pr->pr_mtx);
1395                         if (!n || n->m_next || n->m_len == 0)
1396                                 goto bad;
1397                         IP6_EXTHDR_GET(subj, char *, m,
1398                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1399                         if (subj == NULL)
1400                                 goto bad;
1401                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1402                             n->m_len)) {
1403                                 goto bad;
1404                         }
1405                         m_freem(n);
1406                         n = NULL;
1407                         break;
1408
1409                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1410                 default:
1411                         goto bad;
1412                 }
1413                 break;
1414         }
1415
1416         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1417         switch (qtype) {
1418         case NI_QTYPE_FQDN:
1419                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1420                         goto bad;
1421                 break;
1422         case NI_QTYPE_NODEADDR:
1423         case NI_QTYPE_IPV4ADDR:
1424                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1425                         goto bad;
1426                 break;
1427         }
1428
1429         /* guess reply length */
1430         switch (qtype) {
1431         case NI_QTYPE_NOOP:
1432                 break;          /* no reply data */
1433         case NI_QTYPE_SUPTYPES:
1434                 replylen += sizeof(u_int32_t);
1435                 break;
1436         case NI_QTYPE_FQDN:
1437                 /* XXX will append an mbuf */
1438                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1439                 break;
1440         case NI_QTYPE_NODEADDR:
1441                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1442                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1443                     sizeof(u_int32_t))) > MCLBYTES)
1444                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1445                 break;
1446         case NI_QTYPE_IPV4ADDR:
1447                 /* unsupported - should respond with unknown Qtype? */
1448                 break;
1449         default:
1450                 /*
1451                  * XXX: We must return a reply with the ICMP6 code
1452                  * `unknown Qtype' in this case.  However we regard the case
1453                  * as an FQDN query for backward compatibility.
1454                  * Older versions set a random value to this field,
1455                  * so it rarely varies in the defined qtypes.
1456                  * But the mechanism is not reliable...
1457                  * maybe we should obsolete older versions.
1458                  */
1459                 qtype = NI_QTYPE_FQDN;
1460                 /* XXX will append an mbuf */
1461                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1462                 oldfqdn++;
1463                 break;
1464         }
1465
1466         /* Allocate an mbuf to reply. */
1467         if (replylen > MCLBYTES) {
1468                 /*
1469                  * XXX: should we try to allocate more? But MCLBYTES
1470                  * is probably much larger than IPV6_MMTU...
1471                  */
1472                 goto bad;
1473         }
1474         if (replylen > MHLEN)
1475                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1476         else
1477                 n = m_gethdr(M_NOWAIT, m->m_type);
1478         if (n == NULL) {
1479                 m_freem(m);
1480                 return (NULL);
1481         }
1482         m_move_pkthdr(n, m); /* just for recvif and FIB */
1483         n->m_pkthdr.len = n->m_len = replylen;
1484
1485         /* copy mbuf header and IPv6 + Node Information base headers */
1486         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1487         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1488         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1489
1490         /* qtype dependent procedure */
1491         switch (qtype) {
1492         case NI_QTYPE_NOOP:
1493                 nni6->ni_code = ICMP6_NI_SUCCESS;
1494                 nni6->ni_flags = 0;
1495                 break;
1496         case NI_QTYPE_SUPTYPES:
1497         {
1498                 u_int32_t v;
1499                 nni6->ni_code = ICMP6_NI_SUCCESS;
1500                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1501                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1502                 v = (u_int32_t)htonl(0x0000000f);
1503                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1504                 break;
1505         }
1506         case NI_QTYPE_FQDN:
1507                 nni6->ni_code = ICMP6_NI_SUCCESS;
1508                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1509                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1510                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1511                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1512                 /*
1513                  * XXX do we really have FQDN in hostname?
1514                  */
1515                 pr = curthread->td_ucred->cr_prison;
1516                 mtx_lock(&pr->pr_mtx);
1517                 n->m_next = ni6_nametodns(pr->pr_hostname,
1518                     strlen(pr->pr_hostname), oldfqdn);
1519                 mtx_unlock(&pr->pr_mtx);
1520                 if (n->m_next == NULL)
1521                         goto bad;
1522                 /* XXX we assume that n->m_next is not a chain */
1523                 if (n->m_next->m_next != NULL)
1524                         goto bad;
1525                 n->m_pkthdr.len += n->m_next->m_len;
1526                 break;
1527         case NI_QTYPE_NODEADDR:
1528         {
1529                 int lenlim, copied;
1530
1531                 nni6->ni_code = ICMP6_NI_SUCCESS;
1532                 n->m_pkthdr.len = n->m_len =
1533                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1534                 lenlim = M_TRAILINGSPACE(n);
1535                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1536                 /* XXX: reset mbuf length */
1537                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1538                     sizeof(struct icmp6_nodeinfo) + copied;
1539                 break;
1540         }
1541         default:
1542                 break;          /* XXX impossible! */
1543         }
1544
1545         nni6->ni_type = ICMP6_NI_REPLY;
1546         m_freem(m);
1547         return (n);
1548
1549   bad:
1550         m_freem(m);
1551         if (n)
1552                 m_freem(n);
1553         return (NULL);
1554 }
1555
1556 /*
1557  * make a mbuf with DNS-encoded string.  no compression support.
1558  *
1559  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1560  * treated as truncated name (two \0 at the end).  this is a wild guess.
1561  *
1562  * old - return pascal string if non-zero
1563  */
1564 static struct mbuf *
1565 ni6_nametodns(const char *name, int namelen, int old)
1566 {
1567         struct mbuf *m;
1568         char *cp, *ep;
1569         const char *p, *q;
1570         int i, len, nterm;
1571
1572         if (old)
1573                 len = namelen + 1;
1574         else
1575                 len = MCLBYTES;
1576
1577         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1578         if (len > MLEN)
1579                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1580         else
1581                 m = m_get(M_NOWAIT, MT_DATA);
1582         if (m == NULL)
1583                 goto fail;
1584
1585         if (old) {
1586                 m->m_len = len;
1587                 *mtod(m, char *) = namelen;
1588                 bcopy(name, mtod(m, char *) + 1, namelen);
1589                 return m;
1590         } else {
1591                 m->m_len = 0;
1592                 cp = mtod(m, char *);
1593                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1594
1595                 /* if not certain about my name, return empty buffer */
1596                 if (namelen == 0)
1597                         return m;
1598
1599                 /*
1600                  * guess if it looks like shortened hostname, or FQDN.
1601                  * shortened hostname needs two trailing "\0".
1602                  */
1603                 i = 0;
1604                 for (p = name; p < name + namelen; p++) {
1605                         if (*p && *p == '.')
1606                                 i++;
1607                 }
1608                 if (i < 2)
1609                         nterm = 2;
1610                 else
1611                         nterm = 1;
1612
1613                 p = name;
1614                 while (cp < ep && p < name + namelen) {
1615                         i = 0;
1616                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1617                                 i++;
1618                         /* result does not fit into mbuf */
1619                         if (cp + i + 1 >= ep)
1620                                 goto fail;
1621                         /*
1622                          * DNS label length restriction, RFC1035 page 8.
1623                          * "i == 0" case is included here to avoid returning
1624                          * 0-length label on "foo..bar".
1625                          */
1626                         if (i <= 0 || i >= 64)
1627                                 goto fail;
1628                         *cp++ = i;
1629                         bcopy(p, cp, i);
1630                         cp += i;
1631                         p = q;
1632                         if (p < name + namelen && *p == '.')
1633                                 p++;
1634                 }
1635                 /* termination */
1636                 if (cp + nterm >= ep)
1637                         goto fail;
1638                 while (nterm-- > 0)
1639                         *cp++ = '\0';
1640                 m->m_len = cp - mtod(m, char *);
1641                 return m;
1642         }
1643
1644         panic("should not reach here");
1645         /* NOTREACHED */
1646
1647  fail:
1648         if (m)
1649                 m_freem(m);
1650         return NULL;
1651 }
1652
1653 /*
1654  * check if two DNS-encoded string matches.  takes care of truncated
1655  * form (with \0\0 at the end).  no compression support.
1656  * XXX upper/lowercase match (see RFC2065)
1657  */
1658 static int
1659 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1660 {
1661         const char *a0, *b0;
1662         int l;
1663
1664         /* simplest case - need validation? */
1665         if (alen == blen && bcmp(a, b, alen) == 0)
1666                 return 1;
1667
1668         a0 = a;
1669         b0 = b;
1670
1671         /* termination is mandatory */
1672         if (alen < 2 || blen < 2)
1673                 return 0;
1674         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1675                 return 0;
1676         alen--;
1677         blen--;
1678
1679         while (a - a0 < alen && b - b0 < blen) {
1680                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1681                         return 0;
1682
1683                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1684                         return 0;
1685                 /* we don't support compression yet */
1686                 if (a[0] >= 64 || b[0] >= 64)
1687                         return 0;
1688
1689                 /* truncated case */
1690                 if (a[0] == 0 && a - a0 == alen - 1)
1691                         return 1;
1692                 if (b[0] == 0 && b - b0 == blen - 1)
1693                         return 1;
1694                 if (a[0] == 0 || b[0] == 0)
1695                         return 0;
1696
1697                 if (a[0] != b[0])
1698                         return 0;
1699                 l = a[0];
1700                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1701                         return 0;
1702                 if (bcmp(a + 1, b + 1, l) != 0)
1703                         return 0;
1704
1705                 a += 1 + l;
1706                 b += 1 + l;
1707         }
1708
1709         if (a - a0 == alen && b - b0 == blen)
1710                 return 1;
1711         else
1712                 return 0;
1713 }
1714
1715 /*
1716  * calculate the number of addresses to be returned in the node info reply.
1717  */
1718 static int
1719 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1720     struct in6_addr *subj)
1721 {
1722         struct ifnet *ifp;
1723         struct in6_ifaddr *ifa6;
1724         struct ifaddr *ifa;
1725         int addrs = 0, addrsofif, iffound = 0;
1726         int niflags = ni6->ni_flags;
1727
1728         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1729                 switch (ni6->ni_code) {
1730                 case ICMP6_NI_SUBJ_IPV6:
1731                         if (subj == NULL) /* must be impossible... */
1732                                 return (0);
1733                         break;
1734                 default:
1735                         /*
1736                          * XXX: we only support IPv6 subject address for
1737                          * this Qtype.
1738                          */
1739                         return (0);
1740                 }
1741         }
1742
1743         IFNET_RLOCK_NOSLEEP();
1744         TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1745                 addrsofif = 0;
1746                 IF_ADDR_RLOCK(ifp);
1747                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1748                         if (ifa->ifa_addr->sa_family != AF_INET6)
1749                                 continue;
1750                         ifa6 = (struct in6_ifaddr *)ifa;
1751
1752                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1753                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1754                                 iffound = 1;
1755
1756                         /*
1757                          * IPv4-mapped addresses can only be returned by a
1758                          * Node Information proxy, since they represent
1759                          * addresses of IPv4-only nodes, which perforce do
1760                          * not implement this protocol.
1761                          * [icmp-name-lookups-07, Section 5.4]
1762                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1763                          * this function at this moment.
1764                          */
1765
1766                         /* What do we have to do about ::1? */
1767                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1768                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1769                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1770                                         continue;
1771                                 break;
1772                         case IPV6_ADDR_SCOPE_SITELOCAL:
1773                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1774                                         continue;
1775                                 break;
1776                         case IPV6_ADDR_SCOPE_GLOBAL:
1777                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1778                                         continue;
1779                                 break;
1780                         default:
1781                                 continue;
1782                         }
1783
1784                         /*
1785                          * check if anycast is okay.
1786                          * XXX: just experimental.  not in the spec.
1787                          */
1788                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1789                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1790                                 continue; /* we need only unicast addresses */
1791                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1792                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1793                                 continue;
1794                         }
1795                         addrsofif++; /* count the address */
1796                 }
1797                 IF_ADDR_RUNLOCK(ifp);
1798                 if (iffound) {
1799                         *ifpp = ifp;
1800                         IFNET_RUNLOCK_NOSLEEP();
1801                         return (addrsofif);
1802                 }
1803
1804                 addrs += addrsofif;
1805         }
1806         IFNET_RUNLOCK_NOSLEEP();
1807
1808         return (addrs);
1809 }
1810
1811 static int
1812 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1813     struct ifnet *ifp0, int resid)
1814 {
1815         struct ifnet *ifp;
1816         struct in6_ifaddr *ifa6;
1817         struct ifaddr *ifa;
1818         struct ifnet *ifp_dep = NULL;
1819         int copied = 0, allow_deprecated = 0;
1820         u_char *cp = (u_char *)(nni6 + 1);
1821         int niflags = ni6->ni_flags;
1822         u_int32_t ltime;
1823
1824         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1825                 return (0);     /* needless to copy */
1826
1827         IFNET_RLOCK_NOSLEEP();
1828         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1829   again:
1830
1831         for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) {
1832                 IF_ADDR_RLOCK(ifp);
1833                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1834                         if (ifa->ifa_addr->sa_family != AF_INET6)
1835                                 continue;
1836                         ifa6 = (struct in6_ifaddr *)ifa;
1837
1838                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1839                             allow_deprecated == 0) {
1840                                 /*
1841                                  * prefererred address should be put before
1842                                  * deprecated addresses.
1843                                  */
1844
1845                                 /* record the interface for later search */
1846                                 if (ifp_dep == NULL)
1847                                         ifp_dep = ifp;
1848
1849                                 continue;
1850                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1851                             allow_deprecated != 0)
1852                                 continue; /* we now collect deprecated addrs */
1853
1854                         /* What do we have to do about ::1? */
1855                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1856                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1857                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1858                                         continue;
1859                                 break;
1860                         case IPV6_ADDR_SCOPE_SITELOCAL:
1861                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1862                                         continue;
1863                                 break;
1864                         case IPV6_ADDR_SCOPE_GLOBAL:
1865                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1866                                         continue;
1867                                 break;
1868                         default:
1869                                 continue;
1870                         }
1871
1872                         /*
1873                          * check if anycast is okay.
1874                          * XXX: just experimental.  not in the spec.
1875                          */
1876                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1877                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1878                                 continue;
1879                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1880                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1881                                 continue;
1882                         }
1883
1884                         /* now we can copy the address */
1885                         if (resid < sizeof(struct in6_addr) +
1886                             sizeof(u_int32_t)) {
1887                                 IF_ADDR_RUNLOCK(ifp);
1888                                 /*
1889                                  * We give up much more copy.
1890                                  * Set the truncate flag and return.
1891                                  */
1892                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1893                                 IFNET_RUNLOCK_NOSLEEP();
1894                                 return (copied);
1895                         }
1896
1897                         /*
1898                          * Set the TTL of the address.
1899                          * The TTL value should be one of the following
1900                          * according to the specification:
1901                          *
1902                          * 1. The remaining lifetime of a DHCP lease on the
1903                          *    address, or
1904                          * 2. The remaining Valid Lifetime of a prefix from
1905                          *    which the address was derived through Stateless
1906                          *    Autoconfiguration.
1907                          *
1908                          * Note that we currently do not support stateful
1909                          * address configuration by DHCPv6, so the former
1910                          * case can't happen.
1911                          */
1912                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1913                                 ltime = ND6_INFINITE_LIFETIME;
1914                         else {
1915                                 if (ifa6->ia6_lifetime.ia6t_expire >
1916                                     time_uptime)
1917                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1918                                 else
1919                                         ltime = 0;
1920                         }
1921
1922                         bcopy(&ltime, cp, sizeof(u_int32_t));
1923                         cp += sizeof(u_int32_t);
1924
1925                         /* copy the address itself */
1926                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1927                             sizeof(struct in6_addr));
1928                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1929                         cp += sizeof(struct in6_addr);
1930
1931                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1932                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1933                 }
1934                 IF_ADDR_RUNLOCK(ifp);
1935                 if (ifp0)       /* we need search only on the specified IF */
1936                         break;
1937         }
1938
1939         if (allow_deprecated == 0 && ifp_dep != NULL) {
1940                 ifp = ifp_dep;
1941                 allow_deprecated = 1;
1942
1943                 goto again;
1944         }
1945
1946         IFNET_RUNLOCK_NOSLEEP();
1947
1948         return (copied);
1949 }
1950
1951 /*
1952  * XXX almost dup'ed code with rip6_input.
1953  */
1954 static int
1955 icmp6_rip6_input(struct mbuf **mp, int off)
1956 {
1957         struct mbuf *m = *mp;
1958         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1959         struct inpcb *in6p;
1960         struct inpcb *last = NULL;
1961         struct sockaddr_in6 fromsa;
1962         struct icmp6_hdr *icmp6;
1963         struct mbuf *opts = NULL;
1964
1965 #ifndef PULLDOWN_TEST
1966         /* this is assumed to be safe. */
1967         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1968 #else
1969         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1970         if (icmp6 == NULL) {
1971                 /* m is already reclaimed */
1972                 return (IPPROTO_DONE);
1973         }
1974 #endif
1975
1976         /*
1977          * XXX: the address may have embedded scope zone ID, which should be
1978          * hidden from applications.
1979          */
1980         bzero(&fromsa, sizeof(fromsa));
1981         fromsa.sin6_family = AF_INET6;
1982         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1983         fromsa.sin6_addr = ip6->ip6_src;
1984         if (sa6_recoverscope(&fromsa)) {
1985                 m_freem(m);
1986                 return (IPPROTO_DONE);
1987         }
1988
1989         INP_INFO_RLOCK(&V_ripcbinfo);
1990         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1991                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1992                         continue;
1993                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1994                         continue;
1995                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1996                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1997                         continue;
1998                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1999                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
2000                         continue;
2001                 INP_RLOCK(in6p);
2002                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
2003                     in6p->in6p_icmp6filt)) {
2004                         INP_RUNLOCK(in6p);
2005                         continue;
2006                 }
2007                 if (last != NULL) {
2008                         struct  mbuf *n = NULL;
2009
2010                         /*
2011                          * Recent network drivers tend to allocate a single
2012                          * mbuf cluster, rather than to make a couple of
2013                          * mbufs without clusters.  Also, since the IPv6 code
2014                          * path tries to avoid m_pullup(), it is highly
2015                          * probable that we still have an mbuf cluster here
2016                          * even though the necessary length can be stored in an
2017                          * mbuf's internal buffer.
2018                          * Meanwhile, the default size of the receive socket
2019                          * buffer for raw sockets is not so large.  This means
2020                          * the possibility of packet loss is relatively higher
2021                          * than before.  To avoid this scenario, we copy the
2022                          * received data to a separate mbuf that does not use
2023                          * a cluster, if possible.
2024                          * XXX: it is better to copy the data after stripping
2025                          * intermediate headers.
2026                          */
2027                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2028                             m->m_len <= MHLEN) {
2029                                 n = m_get(M_NOWAIT, m->m_type);
2030                                 if (n != NULL) {
2031                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2032                                                 bcopy(m->m_data, n->m_data,
2033                                                       m->m_len);
2034                                                 n->m_len = m->m_len;
2035                                         } else {
2036                                                 m_free(n);
2037                                                 n = NULL;
2038                                         }
2039                                 }
2040                         }
2041                         if (n != NULL ||
2042                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2043                                 if (last->inp_flags & INP_CONTROLOPTS)
2044                                         ip6_savecontrol(last, n, &opts);
2045                                 /* strip intermediate headers */
2046                                 m_adj(n, off);
2047                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2048                                 if (sbappendaddr_locked(
2049                                     &last->inp_socket->so_rcv,
2050                                     (struct sockaddr *)&fromsa, n, opts)
2051                                     == 0) {
2052                                         /* should notify about lost packet */
2053                                         m_freem(n);
2054                                         if (opts) {
2055                                                 m_freem(opts);
2056                                         }
2057                                         SOCKBUF_UNLOCK(
2058                                             &last->inp_socket->so_rcv);
2059                                 } else
2060                                         sorwakeup_locked(last->inp_socket);
2061                                 opts = NULL;
2062                         }
2063                         INP_RUNLOCK(last);
2064                 }
2065                 last = in6p;
2066         }
2067         INP_INFO_RUNLOCK(&V_ripcbinfo);
2068         if (last != NULL) {
2069                 if (last->inp_flags & INP_CONTROLOPTS)
2070                         ip6_savecontrol(last, m, &opts);
2071                 /* strip intermediate headers */
2072                 m_adj(m, off);
2073
2074                 /* avoid using mbuf clusters if possible (see above) */
2075                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2076                     m->m_len <= MHLEN) {
2077                         struct mbuf *n;
2078
2079                         n = m_get(M_NOWAIT, m->m_type);
2080                         if (n != NULL) {
2081                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2082                                         bcopy(m->m_data, n->m_data, m->m_len);
2083                                         n->m_len = m->m_len;
2084
2085                                         m_freem(m);
2086                                         m = n;
2087                                 } else {
2088                                         m_freem(n);
2089                                         n = NULL;
2090                                 }
2091                         }
2092                 }
2093                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2094                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2095                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2096                         m_freem(m);
2097                         if (opts)
2098                                 m_freem(opts);
2099                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2100                 } else
2101                         sorwakeup_locked(last->inp_socket);
2102                 INP_RUNLOCK(last);
2103         } else {
2104                 m_freem(m);
2105                 IP6STAT_DEC(ip6s_delivered);
2106         }
2107         return IPPROTO_DONE;
2108 }
2109
2110 /*
2111  * Reflect the ip6 packet back to the source.
2112  * OFF points to the icmp6 header, counted from the top of the mbuf.
2113  */
2114 void
2115 icmp6_reflect(struct mbuf *m, size_t off)
2116 {
2117         struct in6_addr src6, *srcp;
2118         struct ip6_hdr *ip6;
2119         struct icmp6_hdr *icmp6;
2120         struct in6_ifaddr *ia = NULL;
2121         struct ifnet *outif = NULL;
2122         int plen;
2123         int type, code, hlim;
2124
2125         /* too short to reflect */
2126         if (off < sizeof(struct ip6_hdr)) {
2127                 nd6log((LOG_DEBUG,
2128                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2129                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2130                     __FILE__, __LINE__));
2131                 goto bad;
2132         }
2133
2134         /*
2135          * If there are extra headers between IPv6 and ICMPv6, strip
2136          * off that header first.
2137          */
2138 #ifdef DIAGNOSTIC
2139         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2140                 panic("assumption failed in icmp6_reflect");
2141 #endif
2142         if (off > sizeof(struct ip6_hdr)) {
2143                 size_t l;
2144                 struct ip6_hdr nip6;
2145
2146                 l = off - sizeof(struct ip6_hdr);
2147                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2148                 m_adj(m, l);
2149                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2150                 if (m->m_len < l) {
2151                         if ((m = m_pullup(m, l)) == NULL)
2152                                 return;
2153                 }
2154                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2155         } else /* off == sizeof(struct ip6_hdr) */ {
2156                 size_t l;
2157                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2158                 if (m->m_len < l) {
2159                         if ((m = m_pullup(m, l)) == NULL)
2160                                 return;
2161                 }
2162         }
2163         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2164         ip6 = mtod(m, struct ip6_hdr *);
2165         ip6->ip6_nxt = IPPROTO_ICMPV6;
2166         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2167         type = icmp6->icmp6_type; /* keep type for statistics */
2168         code = icmp6->icmp6_code; /* ditto. */
2169         hlim = 0;
2170         srcp = NULL;
2171
2172         /*
2173          * If the incoming packet was addressed directly to us (i.e. unicast),
2174          * use dst as the src for the reply.
2175          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2176          * (for example) when we encounter an error while forwarding procedure
2177          * destined to a duplicated address of ours.
2178          */
2179         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2180                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2181                 if (ia != NULL && !(ia->ia6_flags &
2182                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2183                         src6 = ia->ia_addr.sin6_addr;
2184                         srcp = &src6;
2185
2186                         if (m->m_pkthdr.rcvif != NULL) {
2187                                 /* XXX: This may not be the outgoing interface */
2188                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2189                         } else
2190                                 hlim = V_ip6_defhlim;
2191                 }
2192                 if (ia != NULL)
2193                         ifa_free(&ia->ia_ifa);
2194         }
2195
2196         if (srcp == NULL) {
2197                 int error;
2198                 struct in6_addr dst6;
2199                 uint32_t scopeid;
2200
2201                 /*
2202                  * This case matches to multicasts, our anycast, or unicasts
2203                  * that we do not own.  Select a source address based on the
2204                  * source address of the erroneous packet.
2205                  */
2206                 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
2207                 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6,
2208                     scopeid, NULL, &src6, &hlim);
2209
2210                 if (error) {
2211                         char ip6buf[INET6_ADDRSTRLEN];
2212                         nd6log((LOG_DEBUG,
2213                             "icmp6_reflect: source can't be determined: "
2214                             "dst=%s, error=%d\n",
2215                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2216                         goto bad;
2217                 }
2218                 srcp = &src6;
2219         }
2220         /*
2221          * ip6_input() drops a packet if its src is multicast.
2222          * So, the src is never multicast.
2223          */
2224         ip6->ip6_dst = ip6->ip6_src;
2225         ip6->ip6_src = *srcp;
2226         ip6->ip6_flow = 0;
2227         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2228         ip6->ip6_vfc |= IPV6_VERSION;
2229         ip6->ip6_nxt = IPPROTO_ICMPV6;
2230         ip6->ip6_hlim = hlim;
2231
2232         icmp6->icmp6_cksum = 0;
2233         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2234             sizeof(struct ip6_hdr), plen);
2235
2236         /*
2237          * XXX option handling
2238          */
2239
2240         m->m_flags &= ~(M_BCAST|M_MCAST);
2241
2242         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2243         if (outif)
2244                 icmp6_ifoutstat_inc(outif, type, code);
2245
2246         return;
2247
2248  bad:
2249         m_freem(m);
2250         return;
2251 }
2252
2253 void
2254 icmp6_fasttimo(void)
2255 {
2256
2257         mld_fasttimo();
2258 }
2259
2260 void
2261 icmp6_slowtimo(void)
2262 {
2263
2264         mld_slowtimo();
2265 }
2266
2267 static const char *
2268 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2269     struct in6_addr *tgt6)
2270 {
2271         static char buf[1024];
2272         char ip6bufs[INET6_ADDRSTRLEN];
2273         char ip6bufd[INET6_ADDRSTRLEN];
2274         char ip6buft[INET6_ADDRSTRLEN];
2275         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2276             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2277             ip6_sprintf(ip6buft, tgt6));
2278         return buf;
2279 }
2280
2281 void
2282 icmp6_redirect_input(struct mbuf *m, int off)
2283 {
2284         struct ifnet *ifp;
2285         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2286         struct nd_redirect *nd_rd;
2287         int icmp6len = ntohs(ip6->ip6_plen);
2288         char *lladdr = NULL;
2289         int lladdrlen = 0;
2290         int is_router;
2291         int is_onlink;
2292         struct in6_addr src6 = ip6->ip6_src;
2293         struct in6_addr redtgt6;
2294         struct in6_addr reddst6;
2295         union nd_opts ndopts;
2296         char ip6buf[INET6_ADDRSTRLEN];
2297
2298         M_ASSERTPKTHDR(m);
2299         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2300
2301         ifp = m->m_pkthdr.rcvif;
2302
2303         /* XXX if we are router, we don't update route by icmp6 redirect */
2304         if (V_ip6_forwarding)
2305                 goto freeit;
2306         if (!V_icmp6_rediraccept)
2307                 goto freeit;
2308
2309 #ifndef PULLDOWN_TEST
2310         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2311         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2312 #else
2313         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2314         if (nd_rd == NULL) {
2315                 ICMP6STAT_INC(icp6s_tooshort);
2316                 return;
2317         }
2318 #endif
2319         redtgt6 = nd_rd->nd_rd_target;
2320         reddst6 = nd_rd->nd_rd_dst;
2321
2322         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2323             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2324                 goto freeit;
2325         }
2326
2327         /* validation */
2328         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2329                 nd6log((LOG_ERR,
2330                     "ICMP6 redirect sent from %s rejected; "
2331                     "must be from linklocal\n",
2332                     ip6_sprintf(ip6buf, &src6)));
2333                 goto bad;
2334         }
2335         if (ip6->ip6_hlim != 255) {
2336                 nd6log((LOG_ERR,
2337                     "ICMP6 redirect sent from %s rejected; "
2338                     "hlim=%d (must be 255)\n",
2339                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2340                 goto bad;
2341         }
2342     {
2343         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2344         struct nhop6_basic nh6;
2345         struct in6_addr kdst;
2346         uint32_t scopeid;
2347
2348         in6_splitscope(&reddst6, &kdst, &scopeid);
2349         if (fib6_lookup_nh_basic(RT_DEFAULT_FIB, &kdst, scopeid, 0, 0,&nh6)==0){
2350                 if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
2351                         nd6log((LOG_ERR,
2352                             "ICMP6 redirect rejected; no route "
2353                             "with inet6 gateway found for redirect dst: %s\n",
2354                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2355                         goto bad;
2356                 }
2357
2358                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
2359                         nd6log((LOG_ERR,
2360                             "ICMP6 redirect rejected; "
2361                             "not equal to gw-for-src=%s (must be same): "
2362                             "%s\n",
2363                             ip6_sprintf(ip6buf, &nh6.nh_addr),
2364                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2365                         goto bad;
2366                 }
2367         } else {
2368                 nd6log((LOG_ERR,
2369                     "ICMP6 redirect rejected; "
2370                     "no route found for redirect dst: %s\n",
2371                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2372                 goto bad;
2373         }
2374     }
2375         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2376                 nd6log((LOG_ERR,
2377                     "ICMP6 redirect rejected; "
2378                     "redirect dst must be unicast: %s\n",
2379                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2380                 goto bad;
2381         }
2382
2383         is_router = is_onlink = 0;
2384         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2385                 is_router = 1;  /* router case */
2386         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2387                 is_onlink = 1;  /* on-link destination case */
2388         if (!is_router && !is_onlink) {
2389                 nd6log((LOG_ERR,
2390                     "ICMP6 redirect rejected; "
2391                     "neither router case nor onlink case: %s\n",
2392                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2393                 goto bad;
2394         }
2395
2396         icmp6len -= sizeof(*nd_rd);
2397         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2398         if (nd6_options(&ndopts) < 0) {
2399                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2400                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2401                 /* nd6_options have incremented stats */
2402                 goto freeit;
2403         }
2404
2405         if (ndopts.nd_opts_tgt_lladdr) {
2406                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2407                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2408         }
2409
2410         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2411                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2412                     "(if %d, icmp6 packet %d): %s\n",
2413                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2414                     ifp->if_addrlen, lladdrlen - 2,
2415                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2416                 goto bad;
2417         }
2418
2419         /* Validation passed. */
2420
2421         /* RFC 2461 8.3 */
2422         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2423             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2424
2425         /*
2426          * Install a gateway route in the better-router case or an interface
2427          * route in the on-link-destination case.
2428          */
2429         {
2430                 struct sockaddr_in6 sdst;
2431                 struct sockaddr_in6 sgw;
2432                 struct sockaddr_in6 ssrc;
2433                 struct sockaddr *gw;
2434                 int rt_flags;
2435                 u_int fibnum;
2436
2437                 bzero(&sdst, sizeof(sdst));
2438                 bzero(&ssrc, sizeof(ssrc));
2439                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2440                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2441                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2442                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2443                 rt_flags = RTF_HOST;
2444                 if (is_router) {
2445                         bzero(&sgw, sizeof(sgw));
2446                         sgw.sin6_family = AF_INET6;
2447                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2448                         bcopy(&redtgt6, &sgw.sin6_addr,
2449                                 sizeof(struct in6_addr));
2450                         gw = (struct sockaddr *)&sgw;
2451                         rt_flags |= RTF_GATEWAY;
2452                 } else
2453                         gw = ifp->if_addr->ifa_addr;
2454                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2455                         in6_rtredirect((struct sockaddr *)&sdst, gw,
2456                             (struct sockaddr *)NULL, rt_flags,
2457                             (struct sockaddr *)&ssrc, fibnum);
2458         }
2459         /* finally update cached route in each socket via pfctlinput */
2460     {
2461         struct sockaddr_in6 sdst;
2462
2463         bzero(&sdst, sizeof(sdst));
2464         sdst.sin6_family = AF_INET6;
2465         sdst.sin6_len = sizeof(struct sockaddr_in6);
2466         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2467         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2468     }
2469
2470  freeit:
2471         m_freem(m);
2472         return;
2473
2474  bad:
2475         ICMP6STAT_INC(icp6s_badredirect);
2476         m_freem(m);
2477 }
2478
2479 void
2480 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2481 {
2482         struct ifnet *ifp;      /* my outgoing interface */
2483         struct in6_addr *ifp_ll6;
2484         struct in6_addr *router_ll6;
2485         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2486         struct mbuf *m = NULL;  /* newly allocated one */
2487         struct m_tag *mtag;
2488         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2489         struct nd_redirect *nd_rd;
2490         struct llentry *ln = NULL;
2491         size_t maxlen;
2492         u_char *p;
2493         struct ifnet *outif = NULL;
2494         struct sockaddr_in6 src_sa;
2495
2496         icmp6_errcount(ND_REDIRECT, 0);
2497
2498         /* if we are not router, we don't send icmp6 redirect */
2499         if (!V_ip6_forwarding)
2500                 goto fail;
2501
2502         /* sanity check */
2503         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2504                 goto fail;
2505
2506         /*
2507          * Address check:
2508          *  the source address must identify a neighbor, and
2509          *  the destination address must not be a multicast address
2510          *  [RFC 2461, sec 8.2]
2511          */
2512         sip6 = mtod(m0, struct ip6_hdr *);
2513         bzero(&src_sa, sizeof(src_sa));
2514         src_sa.sin6_family = AF_INET6;
2515         src_sa.sin6_len = sizeof(src_sa);
2516         src_sa.sin6_addr = sip6->ip6_src;
2517         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2518                 goto fail;
2519         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2520                 goto fail;      /* what should we do here? */
2521
2522         /* rate limit */
2523         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2524                 goto fail;
2525
2526         /*
2527          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2528          * we almost always ask for an mbuf cluster for simplicity.
2529          * (MHLEN < IPV6_MMTU is almost always true)
2530          */
2531 #if IPV6_MMTU >= MCLBYTES
2532 # error assumption failed about IPV6_MMTU and MCLBYTES
2533 #endif
2534         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2535         if (m == NULL)
2536                 goto fail;
2537         M_SETFIB(m, rt->rt_fibnum);
2538         maxlen = M_TRAILINGSPACE(m);
2539         maxlen = min(IPV6_MMTU, maxlen);
2540         /* just for safety */
2541         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2542             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2543                 goto fail;
2544         }
2545
2546         {
2547                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2548                 struct in6_ifaddr *ia;
2549                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2550                                                  IN6_IFF_NOTREADY|
2551                                                  IN6_IFF_ANYCAST)) == NULL)
2552                         goto fail;
2553                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2554                 /* XXXRW: reference released prematurely. */
2555                 ifa_free(&ia->ia_ifa);
2556         }
2557
2558         /* get ip6 linklocal address for the router. */
2559         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2560                 struct sockaddr_in6 *sin6;
2561                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2562                 router_ll6 = &sin6->sin6_addr;
2563                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2564                         router_ll6 = (struct in6_addr *)NULL;
2565         } else
2566                 router_ll6 = (struct in6_addr *)NULL;
2567
2568         /* ip6 */
2569         ip6 = mtod(m, struct ip6_hdr *);
2570         ip6->ip6_flow = 0;
2571         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2572         ip6->ip6_vfc |= IPV6_VERSION;
2573         /* ip6->ip6_plen will be set later */
2574         ip6->ip6_nxt = IPPROTO_ICMPV6;
2575         ip6->ip6_hlim = 255;
2576         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2577         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2578         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2579
2580         /* ND Redirect */
2581         nd_rd = (struct nd_redirect *)(ip6 + 1);
2582         nd_rd->nd_rd_type = ND_REDIRECT;
2583         nd_rd->nd_rd_code = 0;
2584         nd_rd->nd_rd_reserved = 0;
2585         if (rt->rt_flags & RTF_GATEWAY) {
2586                 /*
2587                  * nd_rd->nd_rd_target must be a link-local address in
2588                  * better router cases.
2589                  */
2590                 if (!router_ll6)
2591                         goto fail;
2592                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2593                     sizeof(nd_rd->nd_rd_target));
2594                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2595                     sizeof(nd_rd->nd_rd_dst));
2596         } else {
2597                 /* make sure redtgt == reddst */
2598                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2599                     sizeof(nd_rd->nd_rd_target));
2600                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2601                     sizeof(nd_rd->nd_rd_dst));
2602         }
2603
2604         p = (u_char *)(nd_rd + 1);
2605
2606         if (!router_ll6)
2607                 goto nolladdropt;
2608
2609         {
2610                 /* target lladdr option */
2611                 int len;
2612                 struct nd_opt_hdr *nd_opt;
2613                 char *lladdr;
2614
2615                 IF_AFDATA_RLOCK(ifp);
2616                 ln = nd6_lookup(router_ll6, 0, ifp);
2617                 IF_AFDATA_RUNLOCK(ifp);
2618                 if (ln == NULL)
2619                         goto nolladdropt;
2620
2621                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2622                 len = (len + 7) & ~7;   /* round by 8 */
2623                 /* safety check */
2624                 if (len + (p - (u_char *)ip6) > maxlen)
2625                         goto nolladdropt;
2626
2627                 if (ln->la_flags & LLE_VALID) {
2628                         nd_opt = (struct nd_opt_hdr *)p;
2629                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2630                         nd_opt->nd_opt_len = len >> 3;
2631                         lladdr = (char *)(nd_opt + 1);
2632                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2633                         p += len;
2634                 }
2635         }
2636 nolladdropt:
2637         if (ln != NULL)
2638                 LLE_RUNLOCK(ln);
2639
2640         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2641
2642         /* just to be safe */
2643 #ifdef M_DECRYPTED      /*not openbsd*/
2644         if (m0->m_flags & M_DECRYPTED)
2645                 goto noredhdropt;
2646 #endif
2647         if (p - (u_char *)ip6 > maxlen)
2648                 goto noredhdropt;
2649
2650         {
2651                 /* redirected header option */
2652                 int len;
2653                 struct nd_opt_rd_hdr *nd_opt_rh;
2654
2655                 /*
2656                  * compute the maximum size for icmp6 redirect header option.
2657                  * XXX room for auth header?
2658                  */
2659                 len = maxlen - (p - (u_char *)ip6);
2660                 len &= ~7;
2661
2662                 /* This is just for simplicity. */
2663                 if (m0->m_pkthdr.len != m0->m_len) {
2664                         if (m0->m_next) {
2665                                 m_freem(m0->m_next);
2666                                 m0->m_next = NULL;
2667                         }
2668                         m0->m_pkthdr.len = m0->m_len;
2669                 }
2670
2671                 /*
2672                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2673                  * about padding/truncate rule for the original IP packet.
2674                  * From the discussion on IPv6imp in Feb 1999,
2675                  * the consensus was:
2676                  * - "attach as much as possible" is the goal
2677                  * - pad if not aligned (original size can be guessed by
2678                  *   original ip6 header)
2679                  * Following code adds the padding if it is simple enough,
2680                  * and truncates if not.
2681                  */
2682                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2683                         panic("assumption failed in %s:%d", __FILE__,
2684                             __LINE__);
2685
2686                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2687                         /* not enough room, truncate */
2688                         m0->m_pkthdr.len = m0->m_len = len -
2689                             sizeof(*nd_opt_rh);
2690                 } else {
2691                         /* enough room, pad or truncate */
2692                         size_t extra;
2693
2694                         extra = m0->m_pkthdr.len % 8;
2695                         if (extra) {
2696                                 /* pad if easy enough, truncate if not */
2697                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2698                                         /* pad */
2699                                         m0->m_len += (8 - extra);
2700                                         m0->m_pkthdr.len += (8 - extra);
2701                                 } else {
2702                                         /* truncate */
2703                                         m0->m_pkthdr.len -= extra;
2704                                         m0->m_len -= extra;
2705                                 }
2706                         }
2707                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2708                         m0->m_pkthdr.len = m0->m_len = len -
2709                             sizeof(*nd_opt_rh);
2710                 }
2711
2712                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2713                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2714                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2715                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2716                 p += sizeof(*nd_opt_rh);
2717                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2718
2719                 /* connect m0 to m */
2720                 m_tag_delete_chain(m0, NULL);
2721                 m0->m_flags &= ~M_PKTHDR;
2722                 m->m_next = m0;
2723                 m->m_pkthdr.len = m->m_len + m0->m_len;
2724                 m0 = NULL;
2725         }
2726 noredhdropt:;
2727         if (m0) {
2728                 m_freem(m0);
2729                 m0 = NULL;
2730         }
2731
2732         /* XXX: clear embedded link IDs in the inner header */
2733         in6_clearscope(&sip6->ip6_src);
2734         in6_clearscope(&sip6->ip6_dst);
2735         in6_clearscope(&nd_rd->nd_rd_target);
2736         in6_clearscope(&nd_rd->nd_rd_dst);
2737
2738         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2739
2740         nd_rd->nd_rd_cksum = 0;
2741         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2742             sizeof(*ip6), ntohs(ip6->ip6_plen));
2743
2744         if (send_sendso_input_hook != NULL) {
2745                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2746                         M_NOWAIT);
2747                 if (mtag == NULL)
2748                         goto fail;
2749                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2750                 m_tag_prepend(m, mtag);
2751         }
2752
2753         /* send the packet to outside... */
2754         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2755         if (outif) {
2756                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2757                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2758         }
2759         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2760
2761         return;
2762
2763 fail:
2764         if (m)
2765                 m_freem(m);
2766         if (m0)
2767                 m_freem(m0);
2768 }
2769
2770 /*
2771  * ICMPv6 socket option processing.
2772  */
2773 int
2774 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2775 {
2776         int error = 0;
2777         int optlen;
2778         struct inpcb *inp = sotoinpcb(so);
2779         int level, op, optname;
2780
2781         if (sopt) {
2782                 level = sopt->sopt_level;
2783                 op = sopt->sopt_dir;
2784                 optname = sopt->sopt_name;
2785                 optlen = sopt->sopt_valsize;
2786         } else
2787                 level = op = optname = optlen = 0;
2788
2789         if (level != IPPROTO_ICMPV6) {
2790                 return EINVAL;
2791         }
2792
2793         switch (op) {
2794         case PRCO_SETOPT:
2795                 switch (optname) {
2796                 case ICMP6_FILTER:
2797                     {
2798                         struct icmp6_filter ic6f;
2799
2800                         if (optlen != sizeof(ic6f)) {
2801                                 error = EMSGSIZE;
2802                                 break;
2803                         }
2804                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2805                         if (error == 0) {
2806                                 INP_WLOCK(inp);
2807                                 *inp->in6p_icmp6filt = ic6f;
2808                                 INP_WUNLOCK(inp);
2809                         }
2810                         break;
2811                     }
2812
2813                 default:
2814                         error = ENOPROTOOPT;
2815                         break;
2816                 }
2817                 break;
2818
2819         case PRCO_GETOPT:
2820                 switch (optname) {
2821                 case ICMP6_FILTER:
2822                     {
2823                         struct icmp6_filter ic6f;
2824
2825                         INP_RLOCK(inp);
2826                         ic6f = *inp->in6p_icmp6filt;
2827                         INP_RUNLOCK(inp);
2828                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2829                         break;
2830                     }
2831
2832                 default:
2833                         error = ENOPROTOOPT;
2834                         break;
2835                 }
2836                 break;
2837         }
2838
2839         return (error);
2840 }
2841
2842 /*
2843  * Perform rate limit check.
2844  * Returns 0 if it is okay to send the icmp6 packet.
2845  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2846  * limitation.
2847  *
2848  * XXX per-destination/type check necessary?
2849  *
2850  * dst - not used at this moment
2851  * type - not used at this moment
2852  * code - not used at this moment
2853  */
2854 static int
2855 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2856     const int code)
2857 {
2858         int ret;
2859
2860         ret = 0;        /* okay to send */
2861
2862         /* PPS limit */
2863         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2864             V_icmp6errppslim)) {
2865                 /* The packet is subject to rate limit */
2866                 ret++;
2867         }
2868
2869         return ret;
2870 }