sys/netinet6/icmp6.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */
   3
   4 /*-
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*-
  34  * Copyright (c) 1982, 1986, 1988, 1993
  35  *      The Regents of the University of California.  All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  62  */
  63
  64 #include "opt_inet.h"
  65 #include "opt_inet6.h"
  66 #include "opt_ipsec.h"
  67
  68 #include <sys/param.h>
  69 #include <sys/domain.h>
  70 #include <sys/kernel.h>
  71 #include <sys/lock.h>
  72 #include <sys/malloc.h>
  73 #include <sys/mbuf.h>
  74 #include <sys/protosw.h>
  75 #include <sys/signalvar.h>
  76 #include <sys/socket.h>
  77 #include <sys/socketvar.h>
  78 #include <sys/sx.h>
  79 #include <sys/syslog.h>
  80 #include <sys/systm.h>
  81 #include <sys/time.h>
  82
  83 #include <net/if.h>
  84 #include <net/if_dl.h>
  85 #include <net/if_types.h>
  86 #include <net/route.h>
  87
  88 #include <netinet/in.h>
  89 #include <netinet/in_pcb.h>
  90 #include <netinet/in_var.h>
  91 #include <netinet/ip6.h>
  92 #include <netinet/icmp6.h>
  93 #include <netinet/tcp_var.h>
  94 #include <netinet6/in6_ifattach.h>
  95 #include <netinet6/in6_pcb.h>
  96 #include <netinet6/ip6protosw.h>
  97 #include <netinet6/ip6_var.h>
  98 #include <netinet6/scope6_var.h>
  99 #include <netinet6/mld6_var.h>
 100 #include <netinet6/nd6.h>
 101
 102 #ifdef IPSEC
 103 #include <netinet6/ipsec.h>
 104 #include <netkey/key.h>
 105 #endif
 106
 107 #ifdef FAST_IPSEC
 108 #include <netipsec/ipsec.h>
 109 #include <netipsec/key.h>
 110 #endif
 111
 112 extern struct domain inet6domain;
 113
 114 struct icmp6stat icmp6stat;
 115
 116 extern struct inpcbinfo ripcbinfo;
 117 extern struct inpcbhead ripcb;
 118 extern int icmp6errppslim;
 119 static int icmp6errpps_count = 0;
 120 static struct timeval icmp6errppslim_last;
 121 extern int icmp6_nodeinfo;
 122
 123 static void icmp6_errcount __P((struct icmp6errstat *, int, int));
 124 static int icmp6_rip6_input __P((struct mbuf **, int));
 125 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
 126 static const char *icmp6_redirect_diag __P((struct in6_addr *,
 127         struct in6_addr *, struct in6_addr *));
 128 static struct mbuf *ni6_input __P((struct mbuf *, int));
 129 static struct mbuf *ni6_nametodns __P((const char *, int, int));
 130 static int ni6_dnsmatch __P((const char *, int, const char *, int));
 131 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
 132                           struct ifnet **, struct in6_addr *));
 133 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 134                                 struct ifnet *, int));
 135 static int icmp6_notify_error __P((struct mbuf **, int, int, int));
 136
 137
 138 void
 139 icmp6_init()
 140 {
 141         mld6_init();
 142 }
 143
 144 static void
 145 icmp6_errcount(stat, type, code)
 146         struct icmp6errstat *stat;
 147         int type, code;
 148 {
 149         switch (type) {
 150         case ICMP6_DST_UNREACH:
 151                 switch (code) {
 152                 case ICMP6_DST_UNREACH_NOROUTE:
 153                         stat->icp6errs_dst_unreach_noroute++;
 154                         return;
 155                 case ICMP6_DST_UNREACH_ADMIN:
 156                         stat->icp6errs_dst_unreach_admin++;
 157                         return;
 158                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 159                         stat->icp6errs_dst_unreach_beyondscope++;
 160                         return;
 161                 case ICMP6_DST_UNREACH_ADDR:
 162                         stat->icp6errs_dst_unreach_addr++;
 163                         return;
 164                 case ICMP6_DST_UNREACH_NOPORT:
 165                         stat->icp6errs_dst_unreach_noport++;
 166                         return;
 167                 }
 168                 break;
 169         case ICMP6_PACKET_TOO_BIG:
 170                 stat->icp6errs_packet_too_big++;
 171                 return;
 172         case ICMP6_TIME_EXCEEDED:
 173                 switch (code) {
 174                 case ICMP6_TIME_EXCEED_TRANSIT:
 175                         stat->icp6errs_time_exceed_transit++;
 176                         return;
 177                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 178                         stat->icp6errs_time_exceed_reassembly++;
 179                         return;
 180                 }
 181                 break;
 182         case ICMP6_PARAM_PROB:
 183                 switch (code) {
 184                 case ICMP6_PARAMPROB_HEADER:
 185                         stat->icp6errs_paramprob_header++;
 186                         return;
 187                 case ICMP6_PARAMPROB_NEXTHEADER:
 188                         stat->icp6errs_paramprob_nextheader++;
 189                         return;
 190                 case ICMP6_PARAMPROB_OPTION:
 191                         stat->icp6errs_paramprob_option++;
 192                         return;
 193                 }
 194                 break;
 195         case ND_REDIRECT:
 196                 stat->icp6errs_redirect++;
 197                 return;
 198         }
 199         stat->icp6errs_unknown++;
 200 }
 201
 202 /*
 203  * A wrapper function for icmp6_error() necessary when the erroneous packet
 204  * may not contain enough scope zone information.
 205  */
 206 void
 207 icmp6_error2(m, type, code, param, ifp)
 208         struct mbuf *m;
 209         int type, code, param;
 210         struct ifnet *ifp;
 211 {
 212         struct ip6_hdr *ip6;
 213
 214         if (ifp == NULL)
 215                 return;
 216
 217 #ifndef PULLDOWN_TEST
 218         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 219 #else
 220         if (m->m_len < sizeof(struct ip6_hdr)) {
 221                 m = m_pullup(m, sizeof(struct ip6_hdr));
 222                 if (m == NULL)
 223                         return;
 224         }
 225 #endif
 226
 227         ip6 = mtod(m, struct ip6_hdr *);
 228
 229         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 230                 return;
 231         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 232                 return;
 233
 234         icmp6_error(m, type, code, param);
 235 }
 236
 237 /*
 238  * Generate an error packet of type error in response to bad IP6 packet.
 239  */
 240 void
 241 icmp6_error(m, type, code, param)
 242         struct mbuf *m;
 243         int type, code, param;
 244 {
 245         struct ip6_hdr *oip6, *nip6;
 246         struct icmp6_hdr *icmp6;
 247         u_int preplen;
 248         int off;
 249         int nxt;
 250
 251         icmp6stat.icp6s_error++;
 252
 253         /* count per-type-code statistics */
 254         icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
 255
 256 #ifdef M_DECRYPTED      /*not openbsd*/
 257         if (m->m_flags & M_DECRYPTED) {
 258                 icmp6stat.icp6s_canterror++;
 259                 goto freeit;
 260         }
 261 #endif
 262
 263 #ifndef PULLDOWN_TEST
 264         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 265 #else
 266         if (m->m_len < sizeof(struct ip6_hdr)) {
 267                 m = m_pullup(m, sizeof(struct ip6_hdr));
 268                 if (m == NULL)
 269                         return;
 270         }
 271 #endif
 272         oip6 = mtod(m, struct ip6_hdr *);
 273
 274         /*
 275          * If the destination address of the erroneous packet is a multicast
 276          * address, or the packet was sent using link-layer multicast,
 277          * we should basically suppress sending an error (RFC 2463, Section
 278          * 2.4).
 279          * We have two exceptions (the item e.2 in that section):
 280          * - the Pakcet Too Big message can be sent for path MTU discovery.
 281          * - the Parameter Problem Message that can be allowed an icmp6 error
 282          *   in the option type field.  This check has been done in
 283          *   ip6_unknown_opt(), so we can just check the type and code.
 284          */
 285         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 286              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 287             (type != ICMP6_PACKET_TOO_BIG &&
 288              (type != ICMP6_PARAM_PROB ||
 289               code != ICMP6_PARAMPROB_OPTION)))
 290                 goto freeit;
 291
 292         /*
 293          * RFC 2463, 2.4 (e.5): source address check.
 294          * XXX: the case of anycast source?
 295          */
 296         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 297             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 298                 goto freeit;
 299
 300         /*
 301          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 302          * don't do it.
 303          */
 304         nxt = -1;
 305         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 306         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 307                 struct icmp6_hdr *icp;
 308
 309 #ifndef PULLDOWN_TEST
 310                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 311                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 312 #else
 313                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 314                         sizeof(*icp));
 315                 if (icp == NULL) {
 316                         icmp6stat.icp6s_tooshort++;
 317                         return;
 318                 }
 319 #endif
 320                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 321                     icp->icmp6_type == ND_REDIRECT) {
 322                         /*
 323                          * ICMPv6 error
 324                          * Special case: for redirect (which is
 325                          * informational) we must not send icmp6 error.
 326                          */
 327                         icmp6stat.icp6s_canterror++;
 328                         goto freeit;
 329                 } else {
 330                         /* ICMPv6 informational - send the error */
 331                 }
 332         } else {
 333                 /* non-ICMPv6 - send the error */
 334         }
 335
 336         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 337
 338         /* Finally, do rate limitation check. */
 339         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 340                 icmp6stat.icp6s_toofreq++;
 341                 goto freeit;
 342         }
 343
 344         /*
 345          * OK, ICMP6 can be generated.
 346          */
 347
 348         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 349                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 350
 351         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 352         M_PREPEND(m, preplen, M_DONTWAIT);
 353         if (m && m->m_len < preplen)
 354                 m = m_pullup(m, preplen);
 355         if (m == NULL) {
 356                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 357                 return;
 358         }
 359
 360         nip6 = mtod(m, struct ip6_hdr *);
 361         nip6->ip6_src  = oip6->ip6_src;
 362         nip6->ip6_dst  = oip6->ip6_dst;
 363
 364         in6_clearscope(&oip6->ip6_src);
 365         in6_clearscope(&oip6->ip6_dst);
 366
 367         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 368         icmp6->icmp6_type = type;
 369         icmp6->icmp6_code = code;
 370         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 371
 372         /*
 373          * icmp6_reflect() is designed to be in the input path.
 374          * icmp6_error() can be called from both input and output path,
 375          * and if we are in output path rcvif could contain bogus value.
 376          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 377          * information in ip header (nip6).
 378          */
 379         m->m_pkthdr.rcvif = NULL;
 380
 381         icmp6stat.icp6s_outhist[type]++;
 382         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 383
 384         return;
 385
 386   freeit:
 387         /*
 388          * If we can't tell whether or not we can generate ICMP6, free it.
 389          */
 390         m_freem(m);
 391 }
 392
 393 /*
 394  * Process a received ICMP6 message.
 395  */
 396 int
 397 icmp6_input(mp, offp, proto)
 398         struct mbuf **mp;
 399         int *offp, proto;
 400 {
 401         struct mbuf *m = *mp, *n;
 402         struct ip6_hdr *ip6, *nip6;
 403         struct icmp6_hdr *icmp6, *nicmp6;
 404         int off = *offp;
 405         int icmp6len = m->m_pkthdr.len - *offp;
 406         int code, sum, noff;
 407         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 408
 409 #ifndef PULLDOWN_TEST
 410         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 411         /* m might change if M_LOOP.  So, call mtod after this */
 412 #endif
 413
 414         /*
 415          * Locate icmp6 structure in mbuf, and check
 416          * that not corrupted and of at least minimum length
 417          */
 418
 419         ip6 = mtod(m, struct ip6_hdr *);
 420         if (icmp6len < sizeof(struct icmp6_hdr)) {
 421                 icmp6stat.icp6s_tooshort++;
 422                 goto freeit;
 423         }
 424
 425         /*
 426          * calculate the checksum
 427          */
 428 #ifndef PULLDOWN_TEST
 429         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 430 #else
 431         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 432         if (icmp6 == NULL) {
 433                 icmp6stat.icp6s_tooshort++;
 434                 return IPPROTO_DONE;
 435         }
 436 #endif
 437         code = icmp6->icmp6_code;
 438
 439         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 440                 nd6log((LOG_ERR,
 441                     "ICMP6 checksum error(%d|%x) %s\n",
 442                     icmp6->icmp6_type, sum,
 443                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 444                 icmp6stat.icp6s_checksum++;
 445                 goto freeit;
 446         }
 447
 448         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 449                 /*
 450                  * Deliver very specific ICMP6 type only.
 451                  * This is important to deliver TOOBIG.  Otherwise PMTUD
 452                  * will not work.
 453                  */
 454                 switch (icmp6->icmp6_type) {
 455                 case ICMP6_DST_UNREACH:
 456                 case ICMP6_PACKET_TOO_BIG:
 457                 case ICMP6_TIME_EXCEEDED:
 458                         break;
 459                 default:
 460                         goto freeit;
 461                 }
 462         }
 463
 464         icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
 465         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
 466         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 467                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
 468
 469         switch (icmp6->icmp6_type) {
 470         case ICMP6_DST_UNREACH:
 471                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
 472                 switch (code) {
 473                 case ICMP6_DST_UNREACH_NOROUTE:
 474                         code = PRC_UNREACH_NET;
 475                         break;
 476                 case ICMP6_DST_UNREACH_ADMIN:
 477                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
 478                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 479                         break;
 480                 case ICMP6_DST_UNREACH_ADDR:
 481                         code = PRC_HOSTDEAD;
 482                         break;
 483                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 484                         /* I mean "source address was incorrect." */
 485                         code = PRC_PARAMPROB;
 486                         break;
 487                 case ICMP6_DST_UNREACH_NOPORT:
 488                         code = PRC_UNREACH_PORT;
 489                         break;
 490                 default:
 491                         goto badcode;
 492                 }
 493                 goto deliver;
 494                 break;
 495
 496         case ICMP6_PACKET_TOO_BIG:
 497                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
 498
 499                 /* validation is made in icmp6_mtudisc_update */
 500
 501                 code = PRC_MSGSIZE;
 502
 503                 /*
 504                  * Updating the path MTU will be done after examining
 505                  * intermediate extension headers.
 506                  */
 507                 goto deliver;
 508                 break;
 509
 510         case ICMP6_TIME_EXCEEDED:
 511                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
 512                 switch (code) {
 513                 case ICMP6_TIME_EXCEED_TRANSIT:
 514                         code = PRC_TIMXCEED_INTRANS;
 515                         break;
 516                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 517                         code = PRC_TIMXCEED_REASS;
 518                         break;
 519                 default:
 520                         goto badcode;
 521                 }
 522                 goto deliver;
 523                 break;
 524
 525         case ICMP6_PARAM_PROB:
 526                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
 527                 switch (code) {
 528                 case ICMP6_PARAMPROB_NEXTHEADER:
 529                         code = PRC_UNREACH_PROTOCOL;
 530                         break;
 531                 case ICMP6_PARAMPROB_HEADER:
 532                 case ICMP6_PARAMPROB_OPTION:
 533                         code = PRC_PARAMPROB;
 534                         break;
 535                 default:
 536                         goto badcode;
 537                 }
 538                 goto deliver;
 539                 break;
 540
 541         case ICMP6_ECHO_REQUEST:
 542                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
 543                 if (code != 0)
 544                         goto badcode;
 545                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 546                         /* Give up remote */
 547                         break;
 548                 }
 549                 if ((n->m_flags & M_EXT) != 0
 550                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 551                         struct mbuf *n0 = n;
 552                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 553                         int n0len;
 554
 555                         MGETHDR(n, M_DONTWAIT, n0->m_type);
 556                         n0len = n0->m_pkthdr.len;       /* save for use below */
 557                         if (n)
 558                                 M_MOVE_PKTHDR(n, n0);
 559                         if (n && maxlen >= MHLEN) {
 560                                 MCLGET(n, M_DONTWAIT);
 561                                 if ((n->m_flags & M_EXT) == 0) {
 562                                         m_free(n);
 563                                         n = NULL;
 564                                 }
 565                         }
 566                         if (n == NULL) {
 567                                 /* Give up remote */
 568                                 m_freem(n0);
 569                                 break;
 570                         }
 571                         /*
 572                          * Copy IPv6 and ICMPv6 only.
 573                          */
 574                         nip6 = mtod(n, struct ip6_hdr *);
 575                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 576                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 577                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 578                         noff = sizeof(struct ip6_hdr);
 579                         /* new mbuf contains only ipv6+icmpv6 headers */
 580                         n->m_len = noff + sizeof(struct icmp6_hdr);
 581                         /*
 582                          * Adjust mbuf.  ip6_plen will be adjusted in
 583                          * ip6_output().
 584                          */
 585                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 586                         /* recalculate complete packet size */
 587                         n->m_pkthdr.len = n0len + (noff - off);
 588                         n->m_next = n0;
 589                 } else {
 590                         nip6 = mtod(n, struct ip6_hdr *);
 591                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 592                             sizeof(*nicmp6));
 593                         noff = off;
 594                 }
 595                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 596                 nicmp6->icmp6_code = 0;
 597                 if (n) {
 598                         icmp6stat.icp6s_reflect++;
 599                         icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
 600                         icmp6_reflect(n, noff);
 601                 }
 602                 break;
 603
 604         case ICMP6_ECHO_REPLY:
 605                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
 606                 if (code != 0)
 607                         goto badcode;
 608                 break;
 609
 610         case MLD_LISTENER_QUERY:
 611         case MLD_LISTENER_REPORT:
 612                 if (icmp6len < sizeof(struct mld_hdr))
 613                         goto badlen;
 614                 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
 615                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
 616                 else
 617                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
 618                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 619                         /* give up local */
 620                         mld6_input(m, off);
 621                         m = NULL;
 622                         goto freeit;
 623                 }
 624                 mld6_input(n, off);
 625                 /* m stays. */
 626                 break;
 627
 628         case MLD_LISTENER_DONE:
 629                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
 630                 if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
 631                         goto badlen;
 632                 break;          /* nothing to be done in kernel */
 633
 634         case MLD_MTRACE_RESP:
 635         case MLD_MTRACE:
 636                 /* XXX: these two are experimental.  not officially defined. */
 637                 /* XXX: per-interface statistics? */
 638                 break;          /* just pass it to applications */
 639
 640         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 641             {
 642                 enum { WRU, FQDN } mode;
 643
 644                 if (!icmp6_nodeinfo)
 645                         break;
 646
 647                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 648                         mode = WRU;
 649                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 650                         mode = FQDN;
 651                 else
 652                         goto badlen;
 653
 654 #define hostnamelen     strlen(hostname)
 655                 if (mode == FQDN) {
 656 #ifndef PULLDOWN_TEST
 657                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 658                             IPPROTO_DONE);
 659 #endif
 660                         n = m_copy(m, 0, M_COPYALL);
 661                         if (n)
 662                                 n = ni6_input(n, off);
 663                         /* XXX meaningless if n == NULL */
 664                         noff = sizeof(struct ip6_hdr);
 665                 } else {
 666                         u_char *p;
 667                         int maxlen, maxhlen;
 668
 669                         /*
 670                          * XXX: this combination of flags is pointless,
 671                          * but should we keep this for compatibility?
 672                          */
 673                         if ((icmp6_nodeinfo & 5) != 5)
 674                                 break;
 675
 676                         if (code != 0)
 677                                 goto badcode;
 678                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 679                         if (maxlen >= MCLBYTES) {
 680                                 /* Give up remote */
 681                                 break;
 682                         }
 683                         MGETHDR(n, M_DONTWAIT, m->m_type);
 684                         if (n && maxlen > MHLEN) {
 685                                 MCLGET(n, M_DONTWAIT);
 686                                 if ((n->m_flags & M_EXT) == 0) {
 687                                         m_free(n);
 688                                         n = NULL;
 689                                 }
 690                         }
 691                         if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
 692                                 /*
 693                                  * Previous code did a blind M_COPY_PKTHDR
 694                                  * and said "just for rcvif".  If true, then
 695                                  * we could tolerate the dup failing (due to
 696                                  * the deep copy of the tag chain).  For now
 697                                  * be conservative and just fail.
 698                                  */
 699                                 m_free(n);
 700                                 n = NULL;
 701                         }
 702                         if (n == NULL) {
 703                                 /* Give up remote */
 704                                 break;
 705                         }
 706                         n->m_pkthdr.rcvif = NULL;
 707                         n->m_len = 0;
 708                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 709                         if (maxhlen > hostnamelen)
 710                                 maxhlen = hostnamelen;
 711                         /*
 712                          * Copy IPv6 and ICMPv6 only.
 713                          */
 714                         nip6 = mtod(n, struct ip6_hdr *);
 715                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 716                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 717                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 718                         p = (u_char *)(nicmp6 + 1);
 719                         bzero(p, 4);
 720                         bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
 721                         noff = sizeof(struct ip6_hdr);
 722                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 723                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 724                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 725                         nicmp6->icmp6_code = 0;
 726                 }
 727 #undef hostnamelen
 728                 if (n) {
 729                         icmp6stat.icp6s_reflect++;
 730                         icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
 731                         icmp6_reflect(n, noff);
 732                 }
 733                 break;
 734             }
 735
 736         case ICMP6_WRUREPLY:
 737                 if (code != 0)
 738                         goto badcode;
 739                 break;
 740
 741         case ND_ROUTER_SOLICIT:
 742                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
 743                 if (code != 0)
 744                         goto badcode;
 745                 if (icmp6len < sizeof(struct nd_router_solicit))
 746                         goto badlen;
 747                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 748                         /* give up local */
 749                         nd6_rs_input(m, off, icmp6len);
 750                         m = NULL;
 751                         goto freeit;
 752                 }
 753                 nd6_rs_input(n, off, icmp6len);
 754                 /* m stays. */
 755                 break;
 756
 757         case ND_ROUTER_ADVERT:
 758                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
 759                 if (code != 0)
 760                         goto badcode;
 761                 if (icmp6len < sizeof(struct nd_router_advert))
 762                         goto badlen;
 763                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 764                         /* give up local */
 765                         nd6_ra_input(m, off, icmp6len);
 766                         m = NULL;
 767                         goto freeit;
 768                 }
 769                 nd6_ra_input(n, off, icmp6len);
 770                 /* m stays. */
 771                 break;
 772
 773         case ND_NEIGHBOR_SOLICIT:
 774                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
 775                 if (code != 0)
 776                         goto badcode;
 777                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 778                         goto badlen;
 779                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 780                         /* give up local */
 781                         nd6_ns_input(m, off, icmp6len);
 782                         m = NULL;
 783                         goto freeit;
 784                 }
 785                 nd6_ns_input(n, off, icmp6len);
 786                 /* m stays. */
 787                 break;
 788
 789         case ND_NEIGHBOR_ADVERT:
 790                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
 791                 if (code != 0)
 792                         goto badcode;
 793                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 794                         goto badlen;
 795                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 796                         /* give up local */
 797                         nd6_na_input(m, off, icmp6len);
 798                         m = NULL;
 799                         goto freeit;
 800                 }
 801                 nd6_na_input(n, off, icmp6len);
 802                 /* m stays. */
 803                 break;
 804
 805         case ND_REDIRECT:
 806                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
 807                 if (code != 0)
 808                         goto badcode;
 809                 if (icmp6len < sizeof(struct nd_redirect))
 810                         goto badlen;
 811                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 812                         /* give up local */
 813                         icmp6_redirect_input(m, off);
 814                         m = NULL;
 815                         goto freeit;
 816                 }
 817                 icmp6_redirect_input(n, off);
 818                 /* m stays. */
 819                 break;
 820
 821         case ICMP6_ROUTER_RENUMBERING:
 822                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 823                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 824                         goto badcode;
 825                 if (icmp6len < sizeof(struct icmp6_router_renum))
 826                         goto badlen;
 827                 break;
 828
 829         default:
 830                 nd6log((LOG_DEBUG,
 831                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 832                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 833                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 834                     m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
 835                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 836                         /* ICMPv6 error: MUST deliver it by spec... */
 837                         code = PRC_NCMDS;
 838                         /* deliver */
 839                 } else {
 840                         /* ICMPv6 informational: MUST not deliver */
 841                         break;
 842                 }
 843         deliver:
 844                 if (icmp6_notify_error(&m, off, icmp6len, code)) {
 845                         /* In this case, m should've been freed. */
 846                         return (IPPROTO_DONE);
 847                 }
 848                 break;
 849
 850         badcode:
 851                 icmp6stat.icp6s_badcode++;
 852                 break;
 853
 854         badlen:
 855                 icmp6stat.icp6s_badlen++;
 856                 break;
 857         }
 858
 859         /* deliver the packet to appropriate sockets */
 860         icmp6_rip6_input(&m, *offp);
 861
 862         return IPPROTO_DONE;
 863
 864  freeit:
 865         m_freem(m);
 866         return IPPROTO_DONE;
 867 }
 868
 869 static int
 870 icmp6_notify_error(mp, off, icmp6len, code)
 871         struct mbuf **mp;
 872         int off, icmp6len, code;
 873 {
 874         struct mbuf *m = *mp;
 875         struct icmp6_hdr *icmp6;
 876         struct ip6_hdr *eip6;
 877         u_int32_t notifymtu;
 878         struct sockaddr_in6 icmp6src, icmp6dst;
 879
 880         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 881                 icmp6stat.icp6s_tooshort++;
 882                 goto freeit;
 883         }
 884 #ifndef PULLDOWN_TEST
 885         IP6_EXTHDR_CHECK(m, off,
 886             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 887         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 888 #else
 889         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 890             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 891         if (icmp6 == NULL) {
 892                 icmp6stat.icp6s_tooshort++;
 893                 return (-1);
 894         }
 895 #endif
 896         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 897
 898         /* Detect the upper level protocol */
 899         {
 900                 void (*ctlfunc) __P((int, struct sockaddr *, void *));
 901                 u_int8_t nxt = eip6->ip6_nxt;
 902                 int eoff = off + sizeof(struct icmp6_hdr) +
 903                     sizeof(struct ip6_hdr);
 904                 struct ip6ctlparam ip6cp;
 905                 struct in6_addr *finaldst = NULL;
 906                 int icmp6type = icmp6->icmp6_type;
 907                 struct ip6_frag *fh;
 908                 struct ip6_rthdr *rth;
 909                 struct ip6_rthdr0 *rth0;
 910                 int rthlen;
 911
 912                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 913                         struct ip6_ext *eh;
 914
 915                         switch (nxt) {
 916                         case IPPROTO_HOPOPTS:
 917                         case IPPROTO_DSTOPTS:
 918                         case IPPROTO_AH:
 919 #ifndef PULLDOWN_TEST
 920                                 IP6_EXTHDR_CHECK(m, 0,
 921                                     eoff + sizeof(struct ip6_ext), -1);
 922                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 923 #else
 924                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 925                                     eoff, sizeof(*eh));
 926                                 if (eh == NULL) {
 927                                         icmp6stat.icp6s_tooshort++;
 928                                         return (-1);
 929                                 }
 930 #endif
 931
 932                                 if (nxt == IPPROTO_AH)
 933                                         eoff += (eh->ip6e_len + 2) << 2;
 934                                 else
 935                                         eoff += (eh->ip6e_len + 1) << 3;
 936                                 nxt = eh->ip6e_nxt;
 937                                 break;
 938                         case IPPROTO_ROUTING:
 939                                 /*
 940                                  * When the erroneous packet contains a
 941                                  * routing header, we should examine the
 942                                  * header to determine the final destination.
 943                                  * Otherwise, we can't properly update
 944                                  * information that depends on the final
 945                                  * destination (e.g. path MTU).
 946                                  */
 947 #ifndef PULLDOWN_TEST
 948                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 949                                 rth = (struct ip6_rthdr *)
 950                                     (mtod(m, caddr_t) + eoff);
 951 #else
 952                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 953                                     eoff, sizeof(*rth));
 954                                 if (rth == NULL) {
 955                                         icmp6stat.icp6s_tooshort++;
 956                                         return (-1);
 957                                 }
 958 #endif
 959                                 rthlen = (rth->ip6r_len + 1) << 3;
 960                                 /*
 961                                  * XXX: currently there is no
 962                                  * officially defined type other
 963                                  * than type-0.
 964                                  * Note that if the segment left field
 965                                  * is 0, all intermediate hops must
 966                                  * have been passed.
 967                                  */
 968                                 if (rth->ip6r_segleft &&
 969                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 970                                         int hops;
 971
 972 #ifndef PULLDOWN_TEST
 973                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 974                                         rth0 = (struct ip6_rthdr0 *)
 975                                             (mtod(m, caddr_t) + eoff);
 976 #else
 977                                         IP6_EXTHDR_GET(rth0,
 978                                             struct ip6_rthdr0 *, m,
 979                                             eoff, rthlen);
 980                                         if (rth0 == NULL) {
 981                                                 icmp6stat.icp6s_tooshort++;
 982                                                 return (-1);
 983                                         }
 984 #endif
 985                                         /* just ignore a bogus header */
 986                                         if ((rth0->ip6r0_len % 2) == 0 &&
 987                                             (hops = rth0->ip6r0_len/2))
 988                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 989                                 }
 990                                 eoff += rthlen;
 991                                 nxt = rth->ip6r_nxt;
 992                                 break;
 993                         case IPPROTO_FRAGMENT:
 994 #ifndef PULLDOWN_TEST
 995                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 996                                     sizeof(struct ip6_frag), -1);
 997                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
 998                                     eoff);
 999 #else
1000                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1001                                     eoff, sizeof(*fh));
1002                                 if (fh == NULL) {
1003                                         icmp6stat.icp6s_tooshort++;
1004                                         return (-1);
1005                                 }
1006 #endif
1007                                 /*
1008                                  * Data after a fragment header is meaningless
1009                                  * unless it is the first fragment, but
1010                                  * we'll go to the notify label for path MTU
1011                                  * discovery.
1012                                  */
1013                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1014                                         goto notify;
1015
1016                                 eoff += sizeof(struct ip6_frag);
1017                                 nxt = fh->ip6f_nxt;
1018                                 break;
1019                         default:
1020                                 /*
1021                                  * This case includes ESP and the No Next
1022                                  * Header.  In such cases going to the notify
1023                                  * label does not have any meaning
1024                                  * (i.e. ctlfunc will be NULL), but we go
1025                                  * anyway since we might have to update
1026                                  * path MTU information.
1027                                  */
1028                                 goto notify;
1029                         }
1030                 }
1031           notify:
1032 #ifndef PULLDOWN_TEST
1033                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1034 #else
1035                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1036                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1037                 if (icmp6 == NULL) {
1038                         icmp6stat.icp6s_tooshort++;
1039                         return (-1);
1040                 }
1041 #endif
1042
1043                 /*
1044                  * retrieve parameters from the inner IPv6 header, and convert
1045                  * them into sockaddr structures.
1046                  * XXX: there is no guarantee that the source or destination
1047                  * addresses of the inner packet are in the same scope as
1048                  * the addresses of the icmp packet.  But there is no other
1049                  * way to determine the zone.
1050                  */
1051                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1052
1053                 bzero(&icmp6dst, sizeof(icmp6dst));
1054                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1055                 icmp6dst.sin6_family = AF_INET6;
1056                 if (finaldst == NULL)
1057                         icmp6dst.sin6_addr = eip6->ip6_dst;
1058                 else
1059                         icmp6dst.sin6_addr = *finaldst;
1060                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1061                         goto freeit;
1062                 bzero(&icmp6src, sizeof(icmp6src));
1063                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1064                 icmp6src.sin6_family = AF_INET6;
1065                 icmp6src.sin6_addr = eip6->ip6_src;
1066                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1067                         goto freeit;
1068                 icmp6src.sin6_flowinfo =
1069                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1070
1071                 if (finaldst == NULL)
1072                         finaldst = &eip6->ip6_dst;
1073                 ip6cp.ip6c_m = m;
1074                 ip6cp.ip6c_icmp6 = icmp6;
1075                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1076                 ip6cp.ip6c_off = eoff;
1077                 ip6cp.ip6c_finaldst = finaldst;
1078                 ip6cp.ip6c_src = &icmp6src;
1079                 ip6cp.ip6c_nxt = nxt;
1080
1081                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1082                         notifymtu = ntohl(icmp6->icmp6_mtu);
1083                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1084                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1085                 }
1086
1087                 ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1088                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1089                 if (ctlfunc) {
1090                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1091                             &ip6cp);
1092                 }
1093         }
1094         *mp = m;
1095         return (0);
1096
1097   freeit:
1098         m_freem(m);
1099         return (-1);
1100 }
1101
1102 void
1103 icmp6_mtudisc_update(ip6cp, validated)
1104         struct ip6ctlparam *ip6cp;
1105         int validated;
1106 {
1107         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1108         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1109         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1110         u_int mtu = ntohl(icmp6->icmp6_mtu);
1111         struct in_conninfo inc;
1112
1113 #if 0
1114         /*
1115          * RFC2460 section 5, last paragraph.
1116          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1117          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1118          * due to packet translator in the middle.
1119          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1120          * special handling.
1121          */
1122         if (mtu < IPV6_MMTU)
1123                 return;
1124 #endif
1125
1126         /*
1127          * we reject ICMPv6 too big with abnormally small value.
1128          * XXX what is the good definition of "abnormally small"?
1129          */
1130         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1131                 return;
1132
1133         if (!validated)
1134                 return;
1135
1136         bzero(&inc, sizeof(inc));
1137         inc.inc_flags = 1; /* IPv6 */
1138         inc.inc6_faddr = *dst;
1139         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1140                 return;
1141
1142         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1143                 tcp_hc_updatemtu(&inc, mtu);
1144                 icmp6stat.icp6s_pmtuchg++;
1145         }
1146 }
1147
1148 /*
1149  * Process a Node Information Query packet, based on
1150  * draft-ietf-ipngwg-icmp-name-lookups-07.
1151  *
1152  * Spec incompatibilities:
1153  * - IPv6 Subject address handling
1154  * - IPv4 Subject address handling support missing
1155  * - Proxy reply (answer even if it's not for me)
1156  * - joins NI group address at in6_ifattach() time only, does not cope
1157  *   with hostname changes by sethostname(3)
1158  */
1159 #define hostnamelen     strlen(hostname)
1160 static struct mbuf *
1161 ni6_input(m, off)
1162         struct mbuf *m;
1163         int off;
1164 {
1165         struct icmp6_nodeinfo *ni6, *nni6;
1166         struct mbuf *n = NULL;
1167         u_int16_t qtype;
1168         int subjlen;
1169         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1170         struct ni_reply_fqdn *fqdn;
1171         int addrs;              /* for NI_QTYPE_NODEADDR */
1172         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1173         struct in6_addr in6_subj; /* subject address */
1174         struct ip6_hdr *ip6;
1175         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1176         char *subj = NULL;
1177         struct in6_ifaddr *ia6 = NULL;
1178
1179         ip6 = mtod(m, struct ip6_hdr *);
1180 #ifndef PULLDOWN_TEST
1181         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1182 #else
1183         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1184         if (ni6 == NULL) {
1185                 /* m is already reclaimed */
1186                 return (NULL);
1187         }
1188 #endif
1189
1190         /*
1191          * Validate IPv6 source address.
1192          * The default configuration MUST be to refuse answering queries from
1193          * global-scope addresses according to RFC4602.
1194          * Notes:
1195          *  - it's not very clear what "refuse" means; this implementation
1196          *    simply drops it.
1197          *  - it's not very easy to identify global-scope (unicast) addresses
1198          *    since there are many prefixes for them.  It should be safer
1199          *    and in practice sufficient to check "all" but loopback and
1200          *    link-local (note that site-local unicast was deprecated and
1201          *    ULA is defined as global scope-wise)
1202          */
1203         if ((icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1204             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1205             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1206                 goto bad;
1207
1208         /*
1209          * Validate IPv6 destination address.
1210          *
1211          * The Responder must discard the Query without further processing
1212          * unless it is one of the Responder's unicast or anycast addresses, or
1213          * a link-local scope multicast address which the Responder has joined.
1214          * [RFC4602, Section 5.]
1215          */
1216         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1217                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1218                         goto bad;
1219                 /* else it's a link-local multicast, fine */
1220         } else {                /* unicast or anycast */
1221                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1222                         goto bad; /* XXX impossible */
1223
1224                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1225                     !(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1226                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1227                                 "a temporary address in %s:%d",
1228                                __FILE__, __LINE__));
1229                         goto bad;
1230                 }
1231         }
1232
1233         /* validate query Subject field. */
1234         qtype = ntohs(ni6->ni_qtype);
1235         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1236         switch (qtype) {
1237         case NI_QTYPE_NOOP:
1238         case NI_QTYPE_SUPTYPES:
1239                 /* 07 draft */
1240                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1241                         break;
1242                 /* FALLTHROUGH */
1243         case NI_QTYPE_FQDN:
1244         case NI_QTYPE_NODEADDR:
1245         case NI_QTYPE_IPV4ADDR:
1246                 switch (ni6->ni_code) {
1247                 case ICMP6_NI_SUBJ_IPV6:
1248 #if ICMP6_NI_SUBJ_IPV6 != 0
1249                 case 0:
1250 #endif
1251                         /*
1252                          * backward compatibility - try to accept 03 draft
1253                          * format, where no Subject is present.
1254                          */
1255                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1256                             subjlen == 0) {
1257                                 oldfqdn++;
1258                                 break;
1259                         }
1260 #if ICMP6_NI_SUBJ_IPV6 != 0
1261                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1262                                 goto bad;
1263 #endif
1264
1265                         if (subjlen != sizeof(struct in6_addr))
1266                                 goto bad;
1267
1268                         /*
1269                          * Validate Subject address.
1270                          *
1271                          * Not sure what exactly "address belongs to the node"
1272                          * means in the spec, is it just unicast, or what?
1273                          *
1274                          * At this moment we consider Subject address as
1275                          * "belong to the node" if the Subject address equals
1276                          * to the IPv6 destination address; validation for
1277                          * IPv6 destination address should have done enough
1278                          * check for us.
1279                          *
1280                          * We do not do proxy at this moment.
1281                          */
1282                         /* m_pulldown instead of copy? */
1283                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1284                             subjlen, (caddr_t)&in6_subj);
1285                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1286                                 goto bad;
1287
1288                         subj = (char *)&in6_subj;
1289                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1290                                 break;
1291
1292                         /*
1293                          * XXX if we are to allow other cases, we should really
1294                          * be careful about scope here.
1295                          * basically, we should disallow queries toward IPv6
1296                          * destination X with subject Y,
1297                          * if scope(X) > scope(Y).
1298                          * if we allow scope(X) > scope(Y), it will result in
1299                          * information leakage across scope boundary.
1300                          */
1301                         goto bad;
1302
1303                 case ICMP6_NI_SUBJ_FQDN:
1304                         /*
1305                          * Validate Subject name with gethostname(3).
1306                          *
1307                          * The behavior may need some debate, since:
1308                          * - we are not sure if the node has FQDN as
1309                          *   hostname (returned by gethostname(3)).
1310                          * - the code does wildcard match for truncated names.
1311                          *   however, we are not sure if we want to perform
1312                          *   wildcard match, if gethostname(3) side has
1313                          *   truncated hostname.
1314                          */
1315                         n = ni6_nametodns(hostname, hostnamelen, 0);
1316                         if (!n || n->m_next || n->m_len == 0)
1317                                 goto bad;
1318                         IP6_EXTHDR_GET(subj, char *, m,
1319                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1320                         if (subj == NULL)
1321                                 goto bad;
1322                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1323                             n->m_len)) {
1324                                 goto bad;
1325                         }
1326                         m_freem(n);
1327                         n = NULL;
1328                         break;
1329
1330                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1331                 default:
1332                         goto bad;
1333                 }
1334                 break;
1335         }
1336
1337         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1338         switch (qtype) {
1339         case NI_QTYPE_FQDN:
1340                 if ((icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1341                         goto bad;
1342                 break;
1343         case NI_QTYPE_NODEADDR:
1344         case NI_QTYPE_IPV4ADDR:
1345                 if ((icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1346                         goto bad;
1347                 break;
1348         }
1349
1350         /* guess reply length */
1351         switch (qtype) {
1352         case NI_QTYPE_NOOP:
1353                 break;          /* no reply data */
1354         case NI_QTYPE_SUPTYPES:
1355                 replylen += sizeof(u_int32_t);
1356                 break;
1357         case NI_QTYPE_FQDN:
1358                 /* XXX will append an mbuf */
1359                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1360                 break;
1361         case NI_QTYPE_NODEADDR:
1362                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1363                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1364                     sizeof(u_int32_t))) > MCLBYTES)
1365                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1366                 break;
1367         case NI_QTYPE_IPV4ADDR:
1368                 /* unsupported - should respond with unknown Qtype? */
1369                 break;
1370         default:
1371                 /*
1372                  * XXX: We must return a reply with the ICMP6 code
1373                  * `unknown Qtype' in this case.  However we regard the case
1374                  * as an FQDN query for backward compatibility.
1375                  * Older versions set a random value to this field,
1376                  * so it rarely varies in the defined qtypes.
1377                  * But the mechanism is not reliable...
1378                  * maybe we should obsolete older versions.
1379                  */
1380                 qtype = NI_QTYPE_FQDN;
1381                 /* XXX will append an mbuf */
1382                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1383                 oldfqdn++;
1384                 break;
1385         }
1386
1387         /* allocate an mbuf to reply. */
1388         MGETHDR(n, M_DONTWAIT, m->m_type);
1389         if (n == NULL) {
1390                 m_freem(m);
1391                 return (NULL);
1392         }
1393         M_MOVE_PKTHDR(n, m); /* just for recvif */
1394         if (replylen > MHLEN) {
1395                 if (replylen > MCLBYTES) {
1396                         /*
1397                          * XXX: should we try to allocate more? But MCLBYTES
1398                          * is probably much larger than IPV6_MMTU...
1399                          */
1400                         goto bad;
1401                 }
1402                 MCLGET(n, M_DONTWAIT);
1403                 if ((n->m_flags & M_EXT) == 0) {
1404                         goto bad;
1405                 }
1406         }
1407         n->m_pkthdr.len = n->m_len = replylen;
1408
1409         /* copy mbuf header and IPv6 + Node Information base headers */
1410         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1411         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1412         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1413
1414         /* qtype dependent procedure */
1415         switch (qtype) {
1416         case NI_QTYPE_NOOP:
1417                 nni6->ni_code = ICMP6_NI_SUCCESS;
1418                 nni6->ni_flags = 0;
1419                 break;
1420         case NI_QTYPE_SUPTYPES:
1421         {
1422                 u_int32_t v;
1423                 nni6->ni_code = ICMP6_NI_SUCCESS;
1424                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1425                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1426                 v = (u_int32_t)htonl(0x0000000f);
1427                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1428                 break;
1429         }
1430         case NI_QTYPE_FQDN:
1431                 nni6->ni_code = ICMP6_NI_SUCCESS;
1432                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1433                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1434                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1435                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1436                 /*
1437                  * XXX do we really have FQDN in variable "hostname"?
1438                  */
1439                 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1440                 if (n->m_next == NULL)
1441                         goto bad;
1442                 /* XXX we assume that n->m_next is not a chain */
1443                 if (n->m_next->m_next != NULL)
1444                         goto bad;
1445                 n->m_pkthdr.len += n->m_next->m_len;
1446                 break;
1447         case NI_QTYPE_NODEADDR:
1448         {
1449                 int lenlim, copied;
1450
1451                 nni6->ni_code = ICMP6_NI_SUCCESS;
1452                 n->m_pkthdr.len = n->m_len =
1453                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1454                 lenlim = M_TRAILINGSPACE(n);
1455                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1456                 /* XXX: reset mbuf length */
1457                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1458                     sizeof(struct icmp6_nodeinfo) + copied;
1459                 break;
1460         }
1461         default:
1462                 break;          /* XXX impossible! */
1463         }
1464
1465         nni6->ni_type = ICMP6_NI_REPLY;
1466         m_freem(m);
1467         return (n);
1468
1469   bad:
1470         m_freem(m);
1471         if (n)
1472                 m_freem(n);
1473         return (NULL);
1474 }
1475 #undef hostnamelen
1476
1477 /*
1478  * make a mbuf with DNS-encoded string.  no compression support.
1479  *
1480  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1481  * treated as truncated name (two \0 at the end).  this is a wild guess.
1482  */
1483 static struct mbuf *
1484 ni6_nametodns(name, namelen, old)
1485         const char *name;
1486         int namelen;
1487         int old;        /* return pascal string if non-zero */
1488 {
1489         struct mbuf *m;
1490         char *cp, *ep;
1491         const char *p, *q;
1492         int i, len, nterm;
1493
1494         if (old)
1495                 len = namelen + 1;
1496         else
1497                 len = MCLBYTES;
1498
1499         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1500         MGET(m, M_DONTWAIT, MT_DATA);
1501         if (m && len > MLEN) {
1502                 MCLGET(m, M_DONTWAIT);
1503                 if ((m->m_flags & M_EXT) == 0)
1504                         goto fail;
1505         }
1506         if (!m)
1507                 goto fail;
1508         m->m_next = NULL;
1509
1510         if (old) {
1511                 m->m_len = len;
1512                 *mtod(m, char *) = namelen;
1513                 bcopy(name, mtod(m, char *) + 1, namelen);
1514                 return m;
1515         } else {
1516                 m->m_len = 0;
1517                 cp = mtod(m, char *);
1518                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1519
1520                 /* if not certain about my name, return empty buffer */
1521                 if (namelen == 0)
1522                         return m;
1523
1524                 /*
1525                  * guess if it looks like shortened hostname, or FQDN.
1526                  * shortened hostname needs two trailing "\0".
1527                  */
1528                 i = 0;
1529                 for (p = name; p < name + namelen; p++) {
1530                         if (*p && *p == '.')
1531                                 i++;
1532                 }
1533                 if (i < 2)
1534                         nterm = 2;
1535                 else
1536                         nterm = 1;
1537
1538                 p = name;
1539                 while (cp < ep && p < name + namelen) {
1540                         i = 0;
1541                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1542                                 i++;
1543                         /* result does not fit into mbuf */
1544                         if (cp + i + 1 >= ep)
1545                                 goto fail;
1546                         /*
1547                          * DNS label length restriction, RFC1035 page 8.
1548                          * "i == 0" case is included here to avoid returning
1549                          * 0-length label on "foo..bar".
1550                          */
1551                         if (i <= 0 || i >= 64)
1552                                 goto fail;
1553                         *cp++ = i;
1554                         bcopy(p, cp, i);
1555                         cp += i;
1556                         p = q;
1557                         if (p < name + namelen && *p == '.')
1558                                 p++;
1559                 }
1560                 /* termination */
1561                 if (cp + nterm >= ep)
1562                         goto fail;
1563                 while (nterm-- > 0)
1564                         *cp++ = '\0';
1565                 m->m_len = cp - mtod(m, char *);
1566                 return m;
1567         }
1568
1569         panic("should not reach here");
1570         /* NOTREACHED */
1571
1572  fail:
1573         if (m)
1574                 m_freem(m);
1575         return NULL;
1576 }
1577
1578 /*
1579  * check if two DNS-encoded string matches.  takes care of truncated
1580  * form (with \0\0 at the end).  no compression support.
1581  * XXX upper/lowercase match (see RFC2065)
1582  */
1583 static int
1584 ni6_dnsmatch(a, alen, b, blen)
1585         const char *a;
1586         int alen;
1587         const char *b;
1588         int blen;
1589 {
1590         const char *a0, *b0;
1591         int l;
1592
1593         /* simplest case - need validation? */
1594         if (alen == blen && bcmp(a, b, alen) == 0)
1595                 return 1;
1596
1597         a0 = a;
1598         b0 = b;
1599
1600         /* termination is mandatory */
1601         if (alen < 2 || blen < 2)
1602                 return 0;
1603         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1604                 return 0;
1605         alen--;
1606         blen--;
1607
1608         while (a - a0 < alen && b - b0 < blen) {
1609                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1610                         return 0;
1611
1612                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1613                         return 0;
1614                 /* we don't support compression yet */
1615                 if (a[0] >= 64 || b[0] >= 64)
1616                         return 0;
1617
1618                 /* truncated case */
1619                 if (a[0] == 0 && a - a0 == alen - 1)
1620                         return 1;
1621                 if (b[0] == 0 && b - b0 == blen - 1)
1622                         return 1;
1623                 if (a[0] == 0 || b[0] == 0)
1624                         return 0;
1625
1626                 if (a[0] != b[0])
1627                         return 0;
1628                 l = a[0];
1629                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1630                         return 0;
1631                 if (bcmp(a + 1, b + 1, l) != 0)
1632                         return 0;
1633
1634                 a += 1 + l;
1635                 b += 1 + l;
1636         }
1637
1638         if (a - a0 == alen && b - b0 == blen)
1639                 return 1;
1640         else
1641                 return 0;
1642 }
1643
1644 /*
1645  * calculate the number of addresses to be returned in the node info reply.
1646  */
1647 static int
1648 ni6_addrs(ni6, m, ifpp, subj)
1649         struct icmp6_nodeinfo *ni6;
1650         struct mbuf *m;
1651         struct ifnet **ifpp;
1652         struct in6_addr *subj;
1653 {
1654         struct ifnet *ifp;
1655         struct in6_ifaddr *ifa6;
1656         struct ifaddr *ifa;
1657         int addrs = 0, addrsofif, iffound = 0;
1658         int niflags = ni6->ni_flags;
1659
1660         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1661                 switch (ni6->ni_code) {
1662                 case ICMP6_NI_SUBJ_IPV6:
1663                         if (subj == NULL) /* must be impossible... */
1664                                 return (0);
1665                         break;
1666                 default:
1667                         /*
1668                          * XXX: we only support IPv6 subject address for
1669                          * this Qtype.
1670                          */
1671                         return (0);
1672                 }
1673         }
1674
1675         IFNET_RLOCK();
1676         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1677                 addrsofif = 0;
1678                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1679                         if (ifa->ifa_addr->sa_family != AF_INET6)
1680                                 continue;
1681                         ifa6 = (struct in6_ifaddr *)ifa;
1682
1683                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1684                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1685                                 iffound = 1;
1686
1687                         /*
1688                          * IPv4-mapped addresses can only be returned by a
1689                          * Node Information proxy, since they represent
1690                          * addresses of IPv4-only nodes, which perforce do
1691                          * not implement this protocol.
1692                          * [icmp-name-lookups-07, Section 5.4]
1693                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1694                          * this function at this moment.
1695                          */
1696
1697                         /* What do we have to do about ::1? */
1698                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1699                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1700                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1701                                         continue;
1702                                 break;
1703                         case IPV6_ADDR_SCOPE_SITELOCAL:
1704                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1705                                         continue;
1706                                 break;
1707                         case IPV6_ADDR_SCOPE_GLOBAL:
1708                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1709                                         continue;
1710                                 break;
1711                         default:
1712                                 continue;
1713                         }
1714
1715                         /*
1716                          * check if anycast is okay.
1717                          * XXX: just experimental.  not in the spec.
1718                          */
1719                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1720                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1721                                 continue; /* we need only unicast addresses */
1722                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1723                             (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1724                                 continue;
1725                         }
1726                         addrsofif++; /* count the address */
1727                 }
1728                 if (iffound) {
1729                         *ifpp = ifp;
1730                         IFNET_RUNLOCK();
1731                         return (addrsofif);
1732                 }
1733
1734                 addrs += addrsofif;
1735         }
1736         IFNET_RUNLOCK();
1737
1738         return (addrs);
1739 }
1740
1741 static int
1742 ni6_store_addrs(ni6, nni6, ifp0, resid)
1743         struct icmp6_nodeinfo *ni6, *nni6;
1744         struct ifnet *ifp0;
1745         int resid;
1746 {
1747         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1748         struct in6_ifaddr *ifa6;
1749         struct ifaddr *ifa;
1750         struct ifnet *ifp_dep = NULL;
1751         int copied = 0, allow_deprecated = 0;
1752         u_char *cp = (u_char *)(nni6 + 1);
1753         int niflags = ni6->ni_flags;
1754         u_int32_t ltime;
1755
1756         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1757                 return (0);     /* needless to copy */
1758
1759         IFNET_RLOCK();
1760   again:
1761
1762         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1763                 for (ifa = ifp->if_addrlist.tqh_first; ifa;
1764                      ifa = ifa->ifa_list.tqe_next) {
1765                         if (ifa->ifa_addr->sa_family != AF_INET6)
1766                                 continue;
1767                         ifa6 = (struct in6_ifaddr *)ifa;
1768
1769                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1770                             allow_deprecated == 0) {
1771                                 /*
1772                                  * prefererred address should be put before
1773                                  * deprecated addresses.
1774                                  */
1775
1776                                 /* record the interface for later search */
1777                                 if (ifp_dep == NULL)
1778                                         ifp_dep = ifp;
1779
1780                                 continue;
1781                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1782                             allow_deprecated != 0)
1783                                 continue; /* we now collect deprecated addrs */
1784
1785                         /* What do we have to do about ::1? */
1786                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1787                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1788                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1789                                         continue;
1790                                 break;
1791                         case IPV6_ADDR_SCOPE_SITELOCAL:
1792                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1793                                         continue;
1794                                 break;
1795                         case IPV6_ADDR_SCOPE_GLOBAL:
1796                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1797                                         continue;
1798                                 break;
1799                         default:
1800                                 continue;
1801                         }
1802
1803                         /*
1804                          * check if anycast is okay.
1805                          * XXX: just experimental.  not in the spec.
1806                          */
1807                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1808                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1809                                 continue;
1810                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1811                             (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1812                                 continue;
1813                         }
1814
1815                         /* now we can copy the address */
1816                         if (resid < sizeof(struct in6_addr) +
1817                             sizeof(u_int32_t)) {
1818                                 /*
1819                                  * We give up much more copy.
1820                                  * Set the truncate flag and return.
1821                                  */
1822                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1823                                 IFNET_RUNLOCK();
1824                                 return (copied);
1825                         }
1826
1827                         /*
1828                          * Set the TTL of the address.
1829                          * The TTL value should be one of the following
1830                          * according to the specification:
1831                          *
1832                          * 1. The remaining lifetime of a DHCP lease on the
1833                          *    address, or
1834                          * 2. The remaining Valid Lifetime of a prefix from
1835                          *    which the address was derived through Stateless
1836                          *    Autoconfiguration.
1837                          *
1838                          * Note that we currently do not support stateful
1839                          * address configuration by DHCPv6, so the former
1840                          * case can't happen.
1841                          */
1842                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1843                                 ltime = ND6_INFINITE_LIFETIME;
1844                         else {
1845                                 if (ifa6->ia6_lifetime.ia6t_expire >
1846                                     time_second)
1847                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1848                                 else
1849                                         ltime = 0;
1850                         }
1851
1852                         bcopy(&ltime, cp, sizeof(u_int32_t));
1853                         cp += sizeof(u_int32_t);
1854
1855                         /* copy the address itself */
1856                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1857                             sizeof(struct in6_addr));
1858                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1859                         cp += sizeof(struct in6_addr);
1860
1861                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1862                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1863                 }
1864                 if (ifp0)       /* we need search only on the specified IF */
1865                         break;
1866         }
1867
1868         if (allow_deprecated == 0 && ifp_dep != NULL) {
1869                 ifp = ifp_dep;
1870                 allow_deprecated = 1;
1871
1872                 goto again;
1873         }
1874
1875         IFNET_RUNLOCK();
1876
1877         return (copied);
1878 }
1879
1880 /*
1881  * XXX almost dup'ed code with rip6_input.
1882  */
1883 static int
1884 icmp6_rip6_input(mp, off)
1885         struct  mbuf **mp;
1886         int     off;
1887 {
1888         struct mbuf *m = *mp;
1889         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1890         struct in6pcb *in6p;
1891         struct in6pcb *last = NULL;
1892         struct sockaddr_in6 fromsa;
1893         struct icmp6_hdr *icmp6;
1894         struct mbuf *opts = NULL;
1895
1896 #ifndef PULLDOWN_TEST
1897         /* this is assumed to be safe. */
1898         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1899 #else
1900         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1901         if (icmp6 == NULL) {
1902                 /* m is already reclaimed */
1903                 return (IPPROTO_DONE);
1904         }
1905 #endif
1906
1907         /*
1908          * XXX: the address may have embedded scope zone ID, which should be
1909          * hidden from applications.
1910          */
1911         bzero(&fromsa, sizeof(fromsa));
1912         fromsa.sin6_family = AF_INET6;
1913         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1914         fromsa.sin6_addr = ip6->ip6_src;
1915         if (sa6_recoverscope(&fromsa)) {
1916                 m_freem(m);
1917                 return (IPPROTO_DONE);
1918         }
1919
1920         INP_INFO_RLOCK(&ripcbinfo);
1921         LIST_FOREACH(in6p, &ripcb, inp_list) {
1922                 INP_LOCK(in6p);
1923                 if ((in6p->inp_vflag & INP_IPV6) == 0) {
1924         docontinue:
1925                         INP_UNLOCK(in6p);
1926                         continue;
1927                 }
1928                 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1929                         goto docontinue;
1930                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1931                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1932                         goto docontinue;
1933                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1934                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1935                         goto docontinue;
1936                 if (in6p->in6p_icmp6filt
1937                     && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1938                                  in6p->in6p_icmp6filt))
1939                         goto docontinue;
1940                 if (last) {
1941                         struct  mbuf *n = NULL;
1942
1943                         /*
1944                          * Recent network drivers tend to allocate a single
1945                          * mbuf cluster, rather than to make a couple of
1946                          * mbufs without clusters.  Also, since the IPv6 code
1947                          * path tries to avoid m_pullup(), it is highly
1948                          * probable that we still have an mbuf cluster here
1949                          * even though the necessary length can be stored in an
1950                          * mbuf's internal buffer.
1951                          * Meanwhile, the default size of the receive socket
1952                          * buffer for raw sockets is not so large.  This means
1953                          * the possibility of packet loss is relatively higher
1954                          * than before.  To avoid this scenario, we copy the
1955                          * received data to a separate mbuf that does not use
1956                          * a cluster, if possible.
1957                          * XXX: it is better to copy the data after stripping
1958                          * intermediate headers.
1959                          */
1960                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1961                             m->m_len <= MHLEN) {
1962                                 MGET(n, M_DONTWAIT, m->m_type);
1963                                 if (n != NULL) {
1964                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1965                                                 bcopy(m->m_data, n->m_data,
1966                                                       m->m_len);
1967                                                 n->m_len = m->m_len;
1968                                         } else {
1969                                                 m_free(n);
1970                                                 n = NULL;
1971                                         }
1972                                 }
1973                         }
1974                         if (n != NULL ||
1975                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1976                                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1977                                         ip6_savecontrol(last, n, &opts);
1978                                 /* strip intermediate headers */
1979                                 m_adj(n, off);
1980                                 SOCKBUF_LOCK(&last->in6p_socket->so_rcv);
1981                                 if (sbappendaddr_locked(
1982                                     &last->in6p_socket->so_rcv,
1983                                     (struct sockaddr *)&fromsa, n, opts)
1984                                     == 0) {
1985                                         /* should notify about lost packet */
1986                                         m_freem(n);
1987                                         if (opts) {
1988                                                 m_freem(opts);
1989                                         }
1990                                         SOCKBUF_UNLOCK(
1991                                             &last->in6p_socket->so_rcv);
1992                                 } else
1993                                         sorwakeup_locked(last->in6p_socket);
1994                                 opts = NULL;
1995                         }
1996                         INP_UNLOCK(last);
1997                 }
1998                 last = in6p;
1999         }
2000         if (last) {
2001                 if (last->in6p_flags & IN6P_CONTROLOPTS)
2002                         ip6_savecontrol(last, m, &opts);
2003                 /* strip intermediate headers */
2004                 m_adj(m, off);
2005
2006                 /* avoid using mbuf clusters if possible (see above) */
2007                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2008                     m->m_len <= MHLEN) {
2009                         struct mbuf *n;
2010
2011                         MGET(n, M_DONTWAIT, m->m_type);
2012                         if (n != NULL) {
2013                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2014                                         bcopy(m->m_data, n->m_data, m->m_len);
2015                                         n->m_len = m->m_len;
2016
2017                                         m_freem(m);
2018                                         m = n;
2019                                 } else {
2020                                         m_freem(n);
2021                                         n = NULL;
2022                                 }
2023                         }
2024                 }
2025                 SOCKBUF_LOCK(&last->in6p_socket->so_rcv);
2026                 if (sbappendaddr_locked(&last->in6p_socket->so_rcv,
2027                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2028                         m_freem(m);
2029                         if (opts)
2030                                 m_freem(opts);
2031                         SOCKBUF_UNLOCK(&last->in6p_socket->so_rcv);
2032                 } else
2033                         sorwakeup_locked(last->in6p_socket);
2034                 INP_UNLOCK(last);
2035         } else {
2036                 m_freem(m);
2037                 ip6stat.ip6s_delivered--;
2038         }
2039         INP_INFO_RUNLOCK(&ripcbinfo);
2040         return IPPROTO_DONE;
2041 }
2042
2043 /*
2044  * Reflect the ip6 packet back to the source.
2045  * OFF points to the icmp6 header, counted from the top of the mbuf.
2046  */
2047 void
2048 icmp6_reflect(m, off)
2049         struct  mbuf *m;
2050         size_t off;
2051 {
2052         struct ip6_hdr *ip6;
2053         struct icmp6_hdr *icmp6;
2054         struct in6_ifaddr *ia;
2055         int plen;
2056         int type, code;
2057         struct ifnet *outif = NULL;
2058         struct in6_addr origdst, *src = NULL;
2059
2060         /* too short to reflect */
2061         if (off < sizeof(struct ip6_hdr)) {
2062                 nd6log((LOG_DEBUG,
2063                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2064                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2065                     __FILE__, __LINE__));
2066                 goto bad;
2067         }
2068
2069         /*
2070          * If there are extra headers between IPv6 and ICMPv6, strip
2071          * off that header first.
2072          */
2073 #ifdef DIAGNOSTIC
2074         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2075                 panic("assumption failed in icmp6_reflect");
2076 #endif
2077         if (off > sizeof(struct ip6_hdr)) {
2078                 size_t l;
2079                 struct ip6_hdr nip6;
2080
2081                 l = off - sizeof(struct ip6_hdr);
2082                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2083                 m_adj(m, l);
2084                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2085                 if (m->m_len < l) {
2086                         if ((m = m_pullup(m, l)) == NULL)
2087                                 return;
2088                 }
2089                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2090         } else /* off == sizeof(struct ip6_hdr) */ {
2091                 size_t l;
2092                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2093                 if (m->m_len < l) {
2094                         if ((m = m_pullup(m, l)) == NULL)
2095                                 return;
2096                 }
2097         }
2098         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2099         ip6 = mtod(m, struct ip6_hdr *);
2100         ip6->ip6_nxt = IPPROTO_ICMPV6;
2101         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2102         type = icmp6->icmp6_type; /* keep type for statistics */
2103         code = icmp6->icmp6_code; /* ditto. */
2104
2105         origdst = ip6->ip6_dst;
2106         /*
2107          * ip6_input() drops a packet if its src is multicast.
2108          * So, the src is never multicast.
2109          */
2110         ip6->ip6_dst = ip6->ip6_src;
2111
2112         /*
2113          * If the incoming packet was addressed directly to us (i.e. unicast),
2114          * use dst as the src for the reply.
2115          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2116          * (for example) when we encounter an error while forwarding procedure
2117          * destined to a duplicated address of ours.
2118          * Note that ip6_getdstifaddr() may fail if we are in an error handling
2119          * procedure of an outgoing packet of our own, in which case we need
2120          * to search in the ifaddr list.
2121          */
2122         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2123                 if ((ia = ip6_getdstifaddr(m))) {
2124                         if (!(ia->ia6_flags &
2125                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2126                                 src = &ia->ia_addr.sin6_addr;
2127                 } else {
2128                         struct sockaddr_in6 d;
2129
2130                         bzero(&d, sizeof(d));
2131                         d.sin6_family = AF_INET6;
2132                         d.sin6_len = sizeof(d);
2133                         d.sin6_addr = origdst;
2134                         ia = (struct in6_ifaddr *)
2135                             ifa_ifwithaddr((struct sockaddr *)&d);
2136                         if (ia &&
2137                             !(ia->ia6_flags &
2138                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2139                                 src = &ia->ia_addr.sin6_addr;
2140                         }
2141                 }
2142         }
2143
2144         if (src == NULL) {
2145                 int e;
2146                 struct sockaddr_in6 sin6;
2147                 struct route_in6 ro;
2148
2149                 /*
2150                  * This case matches to multicasts, our anycast, or unicasts
2151                  * that we do not own.  Select a source address based on the
2152                  * source address of the erroneous packet.
2153                  */
2154                 bzero(&sin6, sizeof(sin6));
2155                 sin6.sin6_family = AF_INET6;
2156                 sin6.sin6_len = sizeof(sin6);
2157                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2158
2159                 bzero(&ro, sizeof(ro));
2160                 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e);
2161                 if (ro.ro_rt)
2162                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2163                 if (src == NULL) {
2164                         char ip6buf[INET6_ADDRSTRLEN];
2165                         nd6log((LOG_DEBUG,
2166                             "icmp6_reflect: source can't be determined: "
2167                             "dst=%s, error=%d\n",
2168                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2169                         goto bad;
2170                 }
2171         }
2172
2173         ip6->ip6_src = *src;
2174         ip6->ip6_flow = 0;
2175         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2176         ip6->ip6_vfc |= IPV6_VERSION;
2177         ip6->ip6_nxt = IPPROTO_ICMPV6;
2178         if (outif)
2179                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2180         else if (m->m_pkthdr.rcvif) {
2181                 /* XXX: This may not be the outgoing interface */
2182                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2183         } else
2184                 ip6->ip6_hlim = ip6_defhlim;
2185
2186         icmp6->icmp6_cksum = 0;
2187         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2188             sizeof(struct ip6_hdr), plen);
2189
2190         /*
2191          * XXX option handling
2192          */
2193
2194         m->m_flags &= ~(M_BCAST|M_MCAST);
2195
2196         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2197         if (outif)
2198                 icmp6_ifoutstat_inc(outif, type, code);
2199
2200         return;
2201
2202  bad:
2203         m_freem(m);
2204         return;
2205 }
2206
2207 void
2208 icmp6_fasttimo()
2209 {
2210
2211         return;
2212 }
2213
2214 static const char *
2215 icmp6_redirect_diag(src6, dst6, tgt6)
2216         struct in6_addr *src6;
2217         struct in6_addr *dst6;
2218         struct in6_addr *tgt6;
2219 {
2220         static char buf[1024];
2221         char ip6bufs[INET6_ADDRSTRLEN];
2222         char ip6bufd[INET6_ADDRSTRLEN];
2223         char ip6buft[INET6_ADDRSTRLEN];
2224         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2225             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2226             ip6_sprintf(ip6buft, tgt6));
2227         return buf;
2228 }
2229
2230 void
2231 icmp6_redirect_input(m, off)
2232         struct mbuf *m;
2233         int off;
2234 {
2235         struct ifnet *ifp = m->m_pkthdr.rcvif;
2236         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2237         struct nd_redirect *nd_rd;
2238         int icmp6len = ntohs(ip6->ip6_plen);
2239         char *lladdr = NULL;
2240         int lladdrlen = 0;
2241         u_char *redirhdr = NULL;
2242         int redirhdrlen = 0;
2243         struct rtentry *rt = NULL;
2244         int is_router;
2245         int is_onlink;
2246         struct in6_addr src6 = ip6->ip6_src;
2247         struct in6_addr redtgt6;
2248         struct in6_addr reddst6;
2249         union nd_opts ndopts;
2250         char ip6buf[INET6_ADDRSTRLEN];
2251
2252         if (!m || !ifp)
2253                 return;
2254
2255         /* XXX if we are router, we don't update route by icmp6 redirect */
2256         if (ip6_forwarding)
2257                 goto freeit;
2258         if (!icmp6_rediraccept)
2259                 goto freeit;
2260
2261 #ifndef PULLDOWN_TEST
2262         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2263         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2264 #else
2265         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2266         if (nd_rd == NULL) {
2267                 icmp6stat.icp6s_tooshort++;
2268                 return;
2269         }
2270 #endif
2271         redtgt6 = nd_rd->nd_rd_target;
2272         reddst6 = nd_rd->nd_rd_dst;
2273
2274         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2275             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2276                 goto freeit;
2277         }
2278
2279         /* validation */
2280         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2281                 nd6log((LOG_ERR,
2282                     "ICMP6 redirect sent from %s rejected; "
2283                     "must be from linklocal\n",
2284                     ip6_sprintf(ip6buf, &src6)));
2285                 goto bad;
2286         }
2287         if (ip6->ip6_hlim != 255) {
2288                 nd6log((LOG_ERR,
2289                     "ICMP6 redirect sent from %s rejected; "
2290                     "hlim=%d (must be 255)\n",
2291                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2292                 goto bad;
2293         }
2294     {
2295         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2296         struct sockaddr_in6 sin6;
2297         struct in6_addr *gw6;
2298
2299         bzero(&sin6, sizeof(sin6));
2300         sin6.sin6_family = AF_INET6;
2301         sin6.sin6_len = sizeof(struct sockaddr_in6);
2302         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2303         rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2304         if (rt) {
2305                 if (rt->rt_gateway == NULL ||
2306                     rt->rt_gateway->sa_family != AF_INET6) {
2307                         nd6log((LOG_ERR,
2308                             "ICMP6 redirect rejected; no route "
2309                             "with inet6 gateway found for redirect dst: %s\n",
2310                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2311                         RTFREE_LOCKED(rt);
2312                         goto bad;
2313                 }
2314
2315                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2316                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2317                         nd6log((LOG_ERR,
2318                             "ICMP6 redirect rejected; "
2319                             "not equal to gw-for-src=%s (must be same): "
2320                             "%s\n",
2321                             ip6_sprintf(ip6buf, gw6),
2322                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2323                         RTFREE_LOCKED(rt);
2324                         goto bad;
2325                 }
2326         } else {
2327                 nd6log((LOG_ERR,
2328                     "ICMP6 redirect rejected; "
2329                     "no route found for redirect dst: %s\n",
2330                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2331                 goto bad;
2332         }
2333         RTFREE_LOCKED(rt);
2334         rt = NULL;
2335     }
2336         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2337                 nd6log((LOG_ERR,
2338                     "ICMP6 redirect rejected; "
2339                     "redirect dst must be unicast: %s\n",
2340                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2341                 goto bad;
2342         }
2343
2344         is_router = is_onlink = 0;
2345         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2346                 is_router = 1;  /* router case */
2347         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2348                 is_onlink = 1;  /* on-link destination case */
2349         if (!is_router && !is_onlink) {
2350                 nd6log((LOG_ERR,
2351                     "ICMP6 redirect rejected; "
2352                     "neither router case nor onlink case: %s\n",
2353                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2354                 goto bad;
2355         }
2356         /* validation passed */
2357
2358         icmp6len -= sizeof(*nd_rd);
2359         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2360         if (nd6_options(&ndopts) < 0) {
2361                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2362                     "invalid ND option, rejected: %s\n",
2363                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2364                 /* nd6_options have incremented stats */
2365                 goto freeit;
2366         }
2367
2368         if (ndopts.nd_opts_tgt_lladdr) {
2369                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2370                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2371         }
2372
2373         if (ndopts.nd_opts_rh) {
2374                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2375                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2376         }
2377
2378         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2379                 nd6log((LOG_INFO,
2380                     "icmp6_redirect_input: lladdrlen mismatch for %s "
2381                     "(if %d, icmp6 packet %d): %s\n",
2382                     ip6_sprintf(ip6buf, &redtgt6),
2383                     ifp->if_addrlen, lladdrlen - 2,
2384                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2385                 goto bad;
2386         }
2387
2388         /* RFC 2461 8.3 */
2389         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2390             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2391
2392         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2393                 /* perform rtredirect */
2394                 struct sockaddr_in6 sdst;
2395                 struct sockaddr_in6 sgw;
2396                 struct sockaddr_in6 ssrc;
2397
2398                 bzero(&sdst, sizeof(sdst));
2399                 bzero(&sgw, sizeof(sgw));
2400                 bzero(&ssrc, sizeof(ssrc));
2401                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2402                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2403                         sizeof(struct sockaddr_in6);
2404                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2405                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2406                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2407                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2408                     (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2409                     (struct sockaddr *)&ssrc);
2410         }
2411         /* finally update cached route in each socket via pfctlinput */
2412     {
2413         struct sockaddr_in6 sdst;
2414
2415         bzero(&sdst, sizeof(sdst));
2416         sdst.sin6_family = AF_INET6;
2417         sdst.sin6_len = sizeof(struct sockaddr_in6);
2418         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2419         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2420 #if defined(IPSEC) || defined(FAST_IPSEC)
2421         key_sa_routechange((struct sockaddr *)&sdst);
2422 #endif
2423     }
2424
2425  freeit:
2426         m_freem(m);
2427         return;
2428
2429  bad:
2430         icmp6stat.icp6s_badredirect++;
2431         m_freem(m);
2432 }
2433
2434 void
2435 icmp6_redirect_output(m0, rt)
2436         struct mbuf *m0;
2437         struct rtentry *rt;
2438 {
2439         struct ifnet *ifp;      /* my outgoing interface */
2440         struct in6_addr *ifp_ll6;
2441         struct in6_addr *router_ll6;
2442         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2443         struct mbuf *m = NULL;  /* newly allocated one */
2444         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2445         struct nd_redirect *nd_rd;
2446         size_t maxlen;
2447         u_char *p;
2448         struct ifnet *outif = NULL;
2449         struct sockaddr_in6 src_sa;
2450
2451         icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2452
2453         /* if we are not router, we don't send icmp6 redirect */
2454         if (!ip6_forwarding)
2455                 goto fail;
2456
2457         /* sanity check */
2458         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2459                 goto fail;
2460
2461         /*
2462          * Address check:
2463          *  the source address must identify a neighbor, and
2464          *  the destination address must not be a multicast address
2465          *  [RFC 2461, sec 8.2]
2466          */
2467         sip6 = mtod(m0, struct ip6_hdr *);
2468         bzero(&src_sa, sizeof(src_sa));
2469         src_sa.sin6_family = AF_INET6;
2470         src_sa.sin6_len = sizeof(src_sa);
2471         src_sa.sin6_addr = sip6->ip6_src;
2472         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2473                 goto fail;
2474         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2475                 goto fail;      /* what should we do here? */
2476
2477         /* rate limit */
2478         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2479                 goto fail;
2480
2481         /*
2482          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2483          * we almost always ask for an mbuf cluster for simplicity.
2484          * (MHLEN < IPV6_MMTU is almost always true)
2485          */
2486 #if IPV6_MMTU >= MCLBYTES
2487 # error assumption failed about IPV6_MMTU and MCLBYTES
2488 #endif
2489         MGETHDR(m, M_DONTWAIT, MT_HEADER);
2490         if (m && IPV6_MMTU >= MHLEN)
2491                 MCLGET(m, M_DONTWAIT);
2492         if (!m)
2493                 goto fail;
2494         m->m_pkthdr.rcvif = NULL;
2495         m->m_len = 0;
2496         maxlen = M_TRAILINGSPACE(m);
2497         maxlen = min(IPV6_MMTU, maxlen);
2498         /* just for safety */
2499         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2500             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2501                 goto fail;
2502         }
2503
2504         {
2505                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2506                 struct in6_ifaddr *ia;
2507                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2508                                                  IN6_IFF_NOTREADY|
2509                                                  IN6_IFF_ANYCAST)) == NULL)
2510                         goto fail;
2511                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2512         }
2513
2514         /* get ip6 linklocal address for the router. */
2515         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2516                 struct sockaddr_in6 *sin6;
2517                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2518                 router_ll6 = &sin6->sin6_addr;
2519                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2520                         router_ll6 = (struct in6_addr *)NULL;
2521         } else
2522                 router_ll6 = (struct in6_addr *)NULL;
2523
2524         /* ip6 */
2525         ip6 = mtod(m, struct ip6_hdr *);
2526         ip6->ip6_flow = 0;
2527         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2528         ip6->ip6_vfc |= IPV6_VERSION;
2529         /* ip6->ip6_plen will be set later */
2530         ip6->ip6_nxt = IPPROTO_ICMPV6;
2531         ip6->ip6_hlim = 255;
2532         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2533         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2534         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2535
2536         /* ND Redirect */
2537         nd_rd = (struct nd_redirect *)(ip6 + 1);
2538         nd_rd->nd_rd_type = ND_REDIRECT;
2539         nd_rd->nd_rd_code = 0;
2540         nd_rd->nd_rd_reserved = 0;
2541         if (rt->rt_flags & RTF_GATEWAY) {
2542                 /*
2543                  * nd_rd->nd_rd_target must be a link-local address in
2544                  * better router cases.
2545                  */
2546                 if (!router_ll6)
2547                         goto fail;
2548                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2549                     sizeof(nd_rd->nd_rd_target));
2550                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2551                     sizeof(nd_rd->nd_rd_dst));
2552         } else {
2553                 /* make sure redtgt == reddst */
2554                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2555                     sizeof(nd_rd->nd_rd_target));
2556                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2557                     sizeof(nd_rd->nd_rd_dst));
2558         }
2559
2560         p = (u_char *)(nd_rd + 1);
2561
2562         if (!router_ll6)
2563                 goto nolladdropt;
2564
2565         {
2566                 /* target lladdr option */
2567                 struct rtentry *rt_router = NULL;
2568                 int len;
2569                 struct sockaddr_dl *sdl;
2570                 struct nd_opt_hdr *nd_opt;
2571                 char *lladdr;
2572
2573                 rt_router = nd6_lookup(router_ll6, 0, ifp);
2574                 if (!rt_router)
2575                         goto nolladdropt;
2576                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2577                 len = (len + 7) & ~7;   /* round by 8 */
2578                 /* safety check */
2579                 if (len + (p - (u_char *)ip6) > maxlen)
2580                         goto nolladdropt;
2581                 if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2582                     (rt_router->rt_flags & RTF_LLINFO) &&
2583                     (rt_router->rt_gateway->sa_family == AF_LINK) &&
2584                     (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2585                     sdl->sdl_alen) {
2586                         nd_opt = (struct nd_opt_hdr *)p;
2587                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2588                         nd_opt->nd_opt_len = len >> 3;
2589                         lladdr = (char *)(nd_opt + 1);
2590                         bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2591                         p += len;
2592                 }
2593         }
2594 nolladdropt:;
2595
2596         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2597
2598         /* just to be safe */
2599 #ifdef M_DECRYPTED      /*not openbsd*/
2600         if (m0->m_flags & M_DECRYPTED)
2601                 goto noredhdropt;
2602 #endif
2603         if (p - (u_char *)ip6 > maxlen)
2604                 goto noredhdropt;
2605
2606         {
2607                 /* redirected header option */
2608                 int len;
2609                 struct nd_opt_rd_hdr *nd_opt_rh;
2610
2611                 /*
2612                  * compute the maximum size for icmp6 redirect header option.
2613                  * XXX room for auth header?
2614                  */
2615                 len = maxlen - (p - (u_char *)ip6);
2616                 len &= ~7;
2617
2618                 /* This is just for simplicity. */
2619                 if (m0->m_pkthdr.len != m0->m_len) {
2620                         if (m0->m_next) {
2621                                 m_freem(m0->m_next);
2622                                 m0->m_next = NULL;
2623                         }
2624                         m0->m_pkthdr.len = m0->m_len;
2625                 }
2626
2627                 /*
2628                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2629                  * about padding/truncate rule for the original IP packet.
2630                  * From the discussion on IPv6imp in Feb 1999,
2631                  * the consensus was:
2632                  * - "attach as much as possible" is the goal
2633                  * - pad if not aligned (original size can be guessed by
2634                  *   original ip6 header)
2635                  * Following code adds the padding if it is simple enough,
2636                  * and truncates if not.
2637                  */
2638                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2639                         panic("assumption failed in %s:%d", __FILE__,
2640                             __LINE__);
2641
2642                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2643                         /* not enough room, truncate */
2644                         m0->m_pkthdr.len = m0->m_len = len -
2645                             sizeof(*nd_opt_rh);
2646                 } else {
2647                         /* enough room, pad or truncate */
2648                         size_t extra;
2649
2650                         extra = m0->m_pkthdr.len % 8;
2651                         if (extra) {
2652                                 /* pad if easy enough, truncate if not */
2653                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2654                                         /* pad */
2655                                         m0->m_len += (8 - extra);
2656                                         m0->m_pkthdr.len += (8 - extra);
2657                                 } else {
2658                                         /* truncate */
2659                                         m0->m_pkthdr.len -= extra;
2660                                         m0->m_len -= extra;
2661                                 }
2662                         }
2663                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2664                         m0->m_pkthdr.len = m0->m_len = len -
2665                             sizeof(*nd_opt_rh);
2666                 }
2667
2668                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2669                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2670                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2671                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2672                 p += sizeof(*nd_opt_rh);
2673                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2674
2675                 /* connect m0 to m */
2676                 m_tag_delete_chain(m0, NULL);
2677                 m0->m_flags &= ~M_PKTHDR;
2678                 m->m_next = m0;
2679                 m->m_pkthdr.len = m->m_len + m0->m_len;
2680                 m0 = NULL;
2681         }
2682 noredhdropt:;
2683         if (m0) {
2684                 m_freem(m0);
2685                 m0 = NULL;
2686         }
2687
2688         /* XXX: clear embedded link IDs in the inner header */
2689         in6_clearscope(&sip6->ip6_src);
2690         in6_clearscope(&sip6->ip6_dst);
2691         in6_clearscope(&nd_rd->nd_rd_target);
2692         in6_clearscope(&nd_rd->nd_rd_dst);
2693
2694         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2695
2696         nd_rd->nd_rd_cksum = 0;
2697         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2698             sizeof(*ip6), ntohs(ip6->ip6_plen));
2699
2700         /* send the packet to outside... */
2701         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2702         if (outif) {
2703                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2704                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2705         }
2706         icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2707
2708         return;
2709
2710 fail:
2711         if (m)
2712                 m_freem(m);
2713         if (m0)
2714                 m_freem(m0);
2715 }
2716
2717 /*
2718  * ICMPv6 socket option processing.
2719  */
2720 int
2721 icmp6_ctloutput(so, sopt)
2722         struct socket *so;
2723         struct sockopt *sopt;
2724 {
2725         int error = 0;
2726         int optlen;
2727         struct inpcb *inp = sotoinpcb(so);
2728         int level, op, optname;
2729
2730         if (sopt) {
2731                 level = sopt->sopt_level;
2732                 op = sopt->sopt_dir;
2733                 optname = sopt->sopt_name;
2734                 optlen = sopt->sopt_valsize;
2735         } else
2736                 level = op = optname = optlen = 0;
2737
2738         if (level != IPPROTO_ICMPV6) {
2739                 return EINVAL;
2740         }
2741
2742         switch (op) {
2743         case PRCO_SETOPT:
2744                 switch (optname) {
2745                 case ICMP6_FILTER:
2746                     {
2747                         struct icmp6_filter *p;
2748
2749                         if (optlen != sizeof(*p)) {
2750                                 error = EMSGSIZE;
2751                                 break;
2752                         }
2753                         if (inp->in6p_icmp6filt == NULL) {
2754                                 error = EINVAL;
2755                                 break;
2756                         }
2757                         error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
2758                                 optlen);
2759                         break;
2760                     }
2761
2762                 default:
2763                         error = ENOPROTOOPT;
2764                         break;
2765                 }
2766                 break;
2767
2768         case PRCO_GETOPT:
2769                 switch (optname) {
2770                 case ICMP6_FILTER:
2771                     {
2772                         if (inp->in6p_icmp6filt == NULL) {
2773                                 error = EINVAL;
2774                                 break;
2775                         }
2776                         error = sooptcopyout(sopt, inp->in6p_icmp6filt,
2777                                 sizeof(struct icmp6_filter));
2778                         break;
2779                     }
2780
2781                 default:
2782                         error = ENOPROTOOPT;
2783                         break;
2784                 }
2785                 break;
2786         }
2787
2788         return (error);
2789 }
2790
2791 /*
2792  * Perform rate limit check.
2793  * Returns 0 if it is okay to send the icmp6 packet.
2794  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2795  * limitation.
2796  *
2797  * XXX per-destination/type check necessary?
2798  */
2799 static int
2800 icmp6_ratelimit(dst, type, code)
2801         const struct in6_addr *dst;     /* not used at this moment */
2802         const int type;                 /* not used at this moment */
2803         const int code;                 /* not used at this moment */
2804 {
2805         int ret;
2806
2807         ret = 0;        /* okay to send */
2808
2809         /* PPS limit */
2810         if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2811             icmp6errppslim)) {
2812                 /* The packet is subject to rate limit */
2813                 ret++;
2814         }
2815
2816         return ret;
2817 }