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/mld6_var.h>
  99 #include <netinet6/nd6.h>
 100
 101 #ifdef IPSEC
 102 #include <netinet6/ipsec.h>
 103 #include <netkey/key.h>
 104 #endif
 105
 106 #ifdef FAST_IPSEC
 107 #include <netipsec/ipsec.h>
 108 #include <netipsec/key.h>
 109 #endif
 110
 111 #include <net/net_osdep.h>
 112
 113 extern struct domain inet6domain;
 114
 115 struct icmp6stat icmp6stat;
 116
 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 **, char *));
 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 #ifdef COMPAT_RFC1885
 138 static struct route_in6 icmp6_reflect_rt;
 139 #endif
 140
 141
 142 void
 143 icmp6_init()
 144 {
 145         mld6_init();
 146 }
 147
 148 static void
 149 icmp6_errcount(stat, type, code)
 150         struct icmp6errstat *stat;
 151         int type, code;
 152 {
 153         switch (type) {
 154         case ICMP6_DST_UNREACH:
 155                 switch (code) {
 156                 case ICMP6_DST_UNREACH_NOROUTE:
 157                         stat->icp6errs_dst_unreach_noroute++;
 158                         return;
 159                 case ICMP6_DST_UNREACH_ADMIN:
 160                         stat->icp6errs_dst_unreach_admin++;
 161                         return;
 162                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 163                         stat->icp6errs_dst_unreach_beyondscope++;
 164                         return;
 165                 case ICMP6_DST_UNREACH_ADDR:
 166                         stat->icp6errs_dst_unreach_addr++;
 167                         return;
 168                 case ICMP6_DST_UNREACH_NOPORT:
 169                         stat->icp6errs_dst_unreach_noport++;
 170                         return;
 171                 }
 172                 break;
 173         case ICMP6_PACKET_TOO_BIG:
 174                 stat->icp6errs_packet_too_big++;
 175                 return;
 176         case ICMP6_TIME_EXCEEDED:
 177                 switch (code) {
 178                 case ICMP6_TIME_EXCEED_TRANSIT:
 179                         stat->icp6errs_time_exceed_transit++;
 180                         return;
 181                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 182                         stat->icp6errs_time_exceed_reassembly++;
 183                         return;
 184                 }
 185                 break;
 186         case ICMP6_PARAM_PROB:
 187                 switch (code) {
 188                 case ICMP6_PARAMPROB_HEADER:
 189                         stat->icp6errs_paramprob_header++;
 190                         return;
 191                 case ICMP6_PARAMPROB_NEXTHEADER:
 192                         stat->icp6errs_paramprob_nextheader++;
 193                         return;
 194                 case ICMP6_PARAMPROB_OPTION:
 195                         stat->icp6errs_paramprob_option++;
 196                         return;
 197                 }
 198                 break;
 199         case ND_REDIRECT:
 200                 stat->icp6errs_redirect++;
 201                 return;
 202         }
 203         stat->icp6errs_unknown++;
 204 }
 205
 206 /*
 207  * Generate an error packet of type error in response to bad IP6 packet.
 208  */
 209 void
 210 icmp6_error(m, type, code, param)
 211         struct mbuf *m;
 212         int type, code, param;
 213 {
 214         struct ip6_hdr *oip6, *nip6;
 215         struct icmp6_hdr *icmp6;
 216         u_int preplen;
 217         int off;
 218         int nxt;
 219
 220         icmp6stat.icp6s_error++;
 221
 222         /* count per-type-code statistics */
 223         icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
 224
 225 #ifdef M_DECRYPTED      /*not openbsd*/
 226         if (m->m_flags & M_DECRYPTED) {
 227                 icmp6stat.icp6s_canterror++;
 228                 goto freeit;
 229         }
 230 #endif
 231
 232 #ifndef PULLDOWN_TEST
 233         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 234 #else
 235         if (m->m_len < sizeof(struct ip6_hdr)) {
 236                 m = m_pullup(m, sizeof(struct ip6_hdr));
 237                 if (m == NULL)
 238                         return;
 239         }
 240 #endif
 241         oip6 = mtod(m, struct ip6_hdr *);
 242
 243         /*
 244          * If the destination address of the erroneous packet is a multicast
 245          * address, or the packet was sent using link-layer multicast,
 246          * we should basically suppress sending an error (RFC 2463, Section
 247          * 2.4).
 248          * We have two exceptions (the item e.2 in that section):
 249          * - the Pakcet Too Big message can be sent for path MTU discovery.
 250          * - the Parameter Problem Message that can be allowed an icmp6 error
 251          *   in the option type field.  This check has been done in
 252          *   ip6_unknown_opt(), so we can just check the type and code.
 253          */
 254         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 255              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 256             (type != ICMP6_PACKET_TOO_BIG &&
 257              (type != ICMP6_PARAM_PROB ||
 258               code != ICMP6_PARAMPROB_OPTION)))
 259                 goto freeit;
 260
 261         /*
 262          * RFC 2463, 2.4 (e.5): source address check.
 263          * XXX: the case of anycast source?
 264          */
 265         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 266             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 267                 goto freeit;
 268
 269         /*
 270          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 271          * don't do it.
 272          */
 273         nxt = -1;
 274         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 275         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 276                 struct icmp6_hdr *icp;
 277
 278 #ifndef PULLDOWN_TEST
 279                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 280                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 281 #else
 282                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 283                         sizeof(*icp));
 284                 if (icp == NULL) {
 285                         icmp6stat.icp6s_tooshort++;
 286                         return;
 287                 }
 288 #endif
 289                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 290                     icp->icmp6_type == ND_REDIRECT) {
 291                         /*
 292                          * ICMPv6 error
 293                          * Special case: for redirect (which is
 294                          * informational) we must not send icmp6 error.
 295                          */
 296                         icmp6stat.icp6s_canterror++;
 297                         goto freeit;
 298                 } else {
 299                         /* ICMPv6 informational - send the error */
 300                 }
 301         } else {
 302                 /* non-ICMPv6 - send the error */
 303         }
 304
 305         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 306
 307         /* Finally, do rate limitation check. */
 308         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 309                 icmp6stat.icp6s_toofreq++;
 310                 goto freeit;
 311         }
 312
 313         /*
 314          * OK, ICMP6 can be generated.
 315          */
 316
 317         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 318                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 319
 320         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 321         M_PREPEND(m, preplen, M_DONTWAIT);
 322         if (m && m->m_len < preplen)
 323                 m = m_pullup(m, preplen);
 324         if (m == NULL) {
 325                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 326                 return;
 327         }
 328
 329         nip6 = mtod(m, struct ip6_hdr *);
 330         nip6->ip6_src  = oip6->ip6_src;
 331         nip6->ip6_dst  = oip6->ip6_dst;
 332
 333         in6_clearscope(&oip6->ip6_src);
 334         in6_clearscope(&oip6->ip6_dst);
 335
 336         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 337         icmp6->icmp6_type = type;
 338         icmp6->icmp6_code = code;
 339         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 340
 341         /*
 342          * icmp6_reflect() is designed to be in the input path.
 343          * icmp6_error() can be called from both input and outut path,
 344          * and if we are in output path rcvif could contain bogus value.
 345          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 346          * information in ip header (nip6).
 347          */
 348         m->m_pkthdr.rcvif = NULL;
 349
 350         icmp6stat.icp6s_outhist[type]++;
 351         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 352
 353         return;
 354
 355   freeit:
 356         /*
 357          * If we can't tell wheter or not we can generate ICMP6, free it.
 358          */
 359         m_freem(m);
 360 }
 361
 362 /*
 363  * Process a received ICMP6 message.
 364  */
 365 int
 366 icmp6_input(mp, offp, proto)
 367         struct mbuf **mp;
 368         int *offp, proto;
 369 {
 370         struct mbuf *m = *mp, *n;
 371         struct ip6_hdr *ip6, *nip6;
 372         struct icmp6_hdr *icmp6, *nicmp6;
 373         int off = *offp;
 374         int icmp6len = m->m_pkthdr.len - *offp;
 375         int code, sum, noff;
 376
 377 #ifndef PULLDOWN_TEST
 378         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 379         /* m might change if M_LOOP.  So, call mtod after this */
 380 #endif
 381
 382         /*
 383          * Locate icmp6 structure in mbuf, and check
 384          * that not corrupted and of at least minimum length
 385          */
 386
 387         ip6 = mtod(m, struct ip6_hdr *);
 388         if (icmp6len < sizeof(struct icmp6_hdr)) {
 389                 icmp6stat.icp6s_tooshort++;
 390                 goto freeit;
 391         }
 392
 393         /*
 394          * calculate the checksum
 395          */
 396 #ifndef PULLDOWN_TEST
 397         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 398 #else
 399         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 400         if (icmp6 == NULL) {
 401                 icmp6stat.icp6s_tooshort++;
 402                 return IPPROTO_DONE;
 403         }
 404 #endif
 405         code = icmp6->icmp6_code;
 406
 407         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 408                 nd6log((LOG_ERR,
 409                     "ICMP6 checksum error(%d|%x) %s\n",
 410                     icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
 411                 icmp6stat.icp6s_checksum++;
 412                 goto freeit;
 413         }
 414
 415         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 416                 /*
 417                  * Deliver very specific ICMP6 type only.
 418                  * This is important to deilver TOOBIG.  Otherwise PMTUD
 419                  * will not work.
 420                  */
 421                 switch (icmp6->icmp6_type) {
 422                 case ICMP6_DST_UNREACH:
 423                 case ICMP6_PACKET_TOO_BIG:
 424                 case ICMP6_TIME_EXCEEDED:
 425                         break;
 426                 default:
 427                         goto freeit;
 428                 }
 429         }
 430
 431         icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
 432         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
 433         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 434                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
 435
 436         switch (icmp6->icmp6_type) {
 437         case ICMP6_DST_UNREACH:
 438                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
 439                 switch (code) {
 440                 case ICMP6_DST_UNREACH_NOROUTE:
 441                         code = PRC_UNREACH_NET;
 442                         break;
 443                 case ICMP6_DST_UNREACH_ADMIN:
 444                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
 445                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 446                         break;
 447                 case ICMP6_DST_UNREACH_ADDR:
 448                         code = PRC_HOSTDEAD;
 449                         break;
 450 #ifdef COMPAT_RFC1885
 451                 case ICMP6_DST_UNREACH_NOTNEIGHBOR:
 452                         code = PRC_UNREACH_SRCFAIL;
 453                         break;
 454 #else
 455                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 456                         /* I mean "source address was incorrect." */
 457                         code = PRC_PARAMPROB;
 458                         break;
 459 #endif
 460                 case ICMP6_DST_UNREACH_NOPORT:
 461                         code = PRC_UNREACH_PORT;
 462                         break;
 463                 default:
 464                         goto badcode;
 465                 }
 466                 goto deliver;
 467                 break;
 468
 469         case ICMP6_PACKET_TOO_BIG:
 470                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
 471                 if (code != 0)
 472                         goto badcode;
 473
 474                 /* validation is made in icmp6_mtudisc_update */
 475
 476                 code = PRC_MSGSIZE;
 477
 478                 /*
 479                  * Updating the path MTU will be done after examining
 480                  * intermediate extension headers.
 481                  */
 482                 goto deliver;
 483                 break;
 484
 485         case ICMP6_TIME_EXCEEDED:
 486                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
 487                 switch (code) {
 488                 case ICMP6_TIME_EXCEED_TRANSIT:
 489                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 490                         code += PRC_TIMXCEED_INTRANS;
 491                         break;
 492                 default:
 493                         goto badcode;
 494                 }
 495                 goto deliver;
 496                 break;
 497
 498         case ICMP6_PARAM_PROB:
 499                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
 500                 switch (code) {
 501                 case ICMP6_PARAMPROB_NEXTHEADER:
 502                         code = PRC_UNREACH_PROTOCOL;
 503                         break;
 504                 case ICMP6_PARAMPROB_HEADER:
 505                 case ICMP6_PARAMPROB_OPTION:
 506                         code = PRC_PARAMPROB;
 507                         break;
 508                 default:
 509                         goto badcode;
 510                 }
 511                 goto deliver;
 512                 break;
 513
 514         case ICMP6_ECHO_REQUEST:
 515                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
 516                 if (code != 0)
 517                         goto badcode;
 518                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 519                         /* Give up remote */
 520                         break;
 521                 }
 522                 if ((n->m_flags & M_EXT) != 0
 523                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 524                         struct mbuf *n0 = n;
 525                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 526                         int n0len;
 527
 528                         /*
 529                          * Prepare an internal mbuf.  m_pullup() doesn't
 530                          * always copy the length we specified.
 531                          */
 532                         if (maxlen >= MCLBYTES) {
 533                                 /* Give up remote */
 534                                 m_freem(n0);
 535                                 break;
 536                         }
 537                         MGETHDR(n, M_DONTWAIT, n0->m_type);
 538                         n0len = n0->m_pkthdr.len;       /* save for use below */
 539                         if (n)
 540                                 M_MOVE_PKTHDR(n, n0);
 541                         if (n && maxlen >= MHLEN) {
 542                                 MCLGET(n, M_DONTWAIT);
 543                                 if ((n->m_flags & M_EXT) == 0) {
 544                                         m_free(n);
 545                                         n = NULL;
 546                                 }
 547                         }
 548                         if (n == NULL) {
 549                                 /* Give up remote */
 550                                 m_freem(n0);
 551                                 break;
 552                         }
 553                         /*
 554                          * Copy IPv6 and ICMPv6 only.
 555                          */
 556                         nip6 = mtod(n, struct ip6_hdr *);
 557                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 558                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 559                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 560                         noff = sizeof(struct ip6_hdr);
 561                         /* new mbuf contains only ipv6+icmpv6 headers */
 562                         n->m_len = noff + sizeof(struct icmp6_hdr);
 563                         /*
 564                          * Adjust mbuf.  ip6_plen will be adjusted in
 565                          * ip6_output().
 566                          */
 567                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 568                         /* recalculate complete packet size */
 569                         n->m_pkthdr.len = n0len + (noff - off);
 570                         n->m_next = n0;
 571                 } else {
 572                         nip6 = mtod(n, struct ip6_hdr *);
 573                         nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
 574                         noff = off;
 575                 }
 576                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 577                 nicmp6->icmp6_code = 0;
 578                 if (n) {
 579                         icmp6stat.icp6s_reflect++;
 580                         icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
 581                         icmp6_reflect(n, noff);
 582                 }
 583                 break;
 584
 585         case ICMP6_ECHO_REPLY:
 586                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
 587                 if (code != 0)
 588                         goto badcode;
 589                 break;
 590
 591         case MLD_LISTENER_QUERY:
 592         case MLD_LISTENER_REPORT:
 593                 if (icmp6len < sizeof(struct mld_hdr))
 594                         goto badlen;
 595                 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
 596                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
 597                 else
 598                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
 599                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 600                         /* give up local */
 601                         mld6_input(m, off);
 602                         m = NULL;
 603                         goto freeit;
 604                 }
 605                 mld6_input(n, off);
 606                 /* m stays. */
 607                 break;
 608
 609         case MLD_LISTENER_DONE:
 610                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
 611                 if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
 612                         goto badlen;
 613                 break;          /* nothing to be done in kernel */
 614
 615         case MLD_MTRACE_RESP:
 616         case MLD_MTRACE:
 617                 /* XXX: these two are experimental.  not officially defined. */
 618                 /* XXX: per-interface statistics? */
 619                 break;          /* just pass it to applications */
 620
 621         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 622             {
 623                 enum { WRU, FQDN } mode;
 624
 625                 if (!icmp6_nodeinfo)
 626                         break;
 627
 628                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 629                         mode = WRU;
 630                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 631                         mode = FQDN;
 632                 else
 633                         goto badlen;
 634
 635 #define hostnamelen     strlen(hostname)
 636                 if (mode == FQDN) {
 637 #ifndef PULLDOWN_TEST
 638                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 639                             IPPROTO_DONE);
 640 #endif
 641                         n = m_copy(m, 0, M_COPYALL);
 642                         if (n)
 643                                 n = ni6_input(n, off);
 644                         /* XXX meaningless if n == NULL */
 645                         noff = sizeof(struct ip6_hdr);
 646                 } else {
 647                         u_char *p;
 648                         int maxlen, maxhlen;
 649
 650                         if ((icmp6_nodeinfo & 5) != 5)
 651                                 break;
 652
 653                         if (code != 0)
 654                                 goto badcode;
 655                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 656                         if (maxlen >= MCLBYTES) {
 657                                 /* Give up remote */
 658                                 break;
 659                         }
 660                         MGETHDR(n, M_DONTWAIT, m->m_type);
 661                         if (n && maxlen > MHLEN) {
 662                                 MCLGET(n, M_DONTWAIT);
 663                                 if ((n->m_flags & M_EXT) == 0) {
 664                                         m_free(n);
 665                                         n = NULL;
 666                                 }
 667                         }
 668                         if (!m_dup_pkthdr(n, m, M_DONTWAIT)) {
 669                                 /*
 670                                  * Previous code did a blind M_COPY_PKTHDR
 671                                  * and said "just for rcvif".  If true, then
 672                                  * we could tolerate the dup failing (due to
 673                                  * the deep copy of the tag chain).  For now
 674                                  * be conservative and just fail.
 675                                  */
 676                                 m_free(n);
 677                                 n = NULL;
 678                         }
 679                         if (n == NULL) {
 680                                 /* Give up remote */
 681                                 break;
 682                         }
 683                         n->m_pkthdr.rcvif = NULL;
 684                         n->m_len = 0;
 685                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 686                         if (maxhlen > hostnamelen)
 687                                 maxhlen = hostnamelen;
 688                         /*
 689                          * Copy IPv6 and ICMPv6 only.
 690                          */
 691                         nip6 = mtod(n, struct ip6_hdr *);
 692                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 693                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 694                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 695                         p = (u_char *)(nicmp6 + 1);
 696                         bzero(p, 4);
 697                         bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
 698                         noff = sizeof(struct ip6_hdr);
 699                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 700                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 701                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 702                         nicmp6->icmp6_code = 0;
 703                 }
 704 #undef hostnamelen
 705                 if (n) {
 706                         icmp6stat.icp6s_reflect++;
 707                         icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
 708                         icmp6_reflect(n, noff);
 709                 }
 710                 break;
 711             }
 712
 713         case ICMP6_WRUREPLY:
 714                 if (code != 0)
 715                         goto badcode;
 716                 break;
 717
 718         case ND_ROUTER_SOLICIT:
 719                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
 720                 if (code != 0)
 721                         goto badcode;
 722                 if (icmp6len < sizeof(struct nd_router_solicit))
 723                         goto badlen;
 724                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 725                         /* give up local */
 726                         nd6_rs_input(m, off, icmp6len);
 727                         m = NULL;
 728                         goto freeit;
 729                 }
 730                 nd6_rs_input(n, off, icmp6len);
 731                 /* m stays. */
 732                 break;
 733
 734         case ND_ROUTER_ADVERT:
 735                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
 736                 if (code != 0)
 737                         goto badcode;
 738                 if (icmp6len < sizeof(struct nd_router_advert))
 739                         goto badlen;
 740                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 741                         /* give up local */
 742                         nd6_ra_input(m, off, icmp6len);
 743                         m = NULL;
 744                         goto freeit;
 745                 }
 746                 nd6_ra_input(n, off, icmp6len);
 747                 /* m stays. */
 748                 break;
 749
 750         case ND_NEIGHBOR_SOLICIT:
 751                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
 752                 if (code != 0)
 753                         goto badcode;
 754                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 755                         goto badlen;
 756                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 757                         /* give up local */
 758                         nd6_ns_input(m, off, icmp6len);
 759                         m = NULL;
 760                         goto freeit;
 761                 }
 762                 nd6_ns_input(n, off, icmp6len);
 763                 /* m stays. */
 764                 break;
 765
 766         case ND_NEIGHBOR_ADVERT:
 767                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
 768                 if (code != 0)
 769                         goto badcode;
 770                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 771                         goto badlen;
 772                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 773                         /* give up local */
 774                         nd6_na_input(m, off, icmp6len);
 775                         m = NULL;
 776                         goto freeit;
 777                 }
 778                 nd6_na_input(n, off, icmp6len);
 779                 /* m stays. */
 780                 break;
 781
 782         case ND_REDIRECT:
 783                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
 784                 if (code != 0)
 785                         goto badcode;
 786                 if (icmp6len < sizeof(struct nd_redirect))
 787                         goto badlen;
 788                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 789                         /* give up local */
 790                         icmp6_redirect_input(m, off);
 791                         m = NULL;
 792                         goto freeit;
 793                 }
 794                 icmp6_redirect_input(n, off);
 795                 /* m stays. */
 796                 break;
 797
 798         case ICMP6_ROUTER_RENUMBERING:
 799                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 800                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 801                         goto badcode;
 802                 if (icmp6len < sizeof(struct icmp6_router_renum))
 803                         goto badlen;
 804                 break;
 805
 806         default:
 807                 nd6log((LOG_DEBUG,
 808                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 809                     icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
 810                     ip6_sprintf(&ip6->ip6_dst),
 811                     m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
 812                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 813                         /* ICMPv6 error: MUST deliver it by spec... */
 814                         code = PRC_NCMDS;
 815                         /* deliver */
 816                 } else {
 817                         /* ICMPv6 informational: MUST not deliver */
 818                         break;
 819                 }
 820         deliver:
 821                 if (icmp6_notify_error(m, off, icmp6len, code)) {
 822                         /* In this case, m should've been freed. */
 823                         return (IPPROTO_DONE);
 824                 }
 825                 break;
 826
 827         badcode:
 828                 icmp6stat.icp6s_badcode++;
 829                 break;
 830
 831         badlen:
 832                 icmp6stat.icp6s_badlen++;
 833                 break;
 834         }
 835
 836         /* deliver the packet to appropriate sockets */
 837         icmp6_rip6_input(&m, *offp);
 838
 839         return IPPROTO_DONE;
 840
 841  freeit:
 842         m_freem(m);
 843         return IPPROTO_DONE;
 844 }
 845
 846 static int
 847 icmp6_notify_error(m, off, icmp6len, code)
 848         struct mbuf *m;
 849         int off, icmp6len, code;
 850 {
 851         struct icmp6_hdr *icmp6;
 852         struct ip6_hdr *eip6;
 853         u_int32_t notifymtu;
 854         struct sockaddr_in6 icmp6src, icmp6dst;
 855
 856         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 857                 icmp6stat.icp6s_tooshort++;
 858                 goto freeit;
 859         }
 860 #ifndef PULLDOWN_TEST
 861         IP6_EXTHDR_CHECK(m, off,
 862             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 863         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 864 #else
 865         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 866             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 867         if (icmp6 == NULL) {
 868                 icmp6stat.icp6s_tooshort++;
 869                 return (-1);
 870         }
 871 #endif
 872         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 873
 874         /* Detect the upper level protocol */
 875         {
 876                 void (*ctlfunc) __P((int, struct sockaddr *, void *));
 877                 u_int8_t nxt = eip6->ip6_nxt;
 878                 int eoff = off + sizeof(struct icmp6_hdr) +
 879                     sizeof(struct ip6_hdr);
 880                 struct ip6ctlparam ip6cp;
 881                 struct in6_addr *finaldst = NULL;
 882                 int icmp6type = icmp6->icmp6_type;
 883                 struct ip6_frag *fh;
 884                 struct ip6_rthdr *rth;
 885                 struct ip6_rthdr0 *rth0;
 886                 int rthlen;
 887
 888                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 889                         struct ip6_ext *eh;
 890
 891                         switch (nxt) {
 892                         case IPPROTO_HOPOPTS:
 893                         case IPPROTO_DSTOPTS:
 894                         case IPPROTO_AH:
 895 #ifndef PULLDOWN_TEST
 896                                 IP6_EXTHDR_CHECK(m, 0,
 897                                     eoff + sizeof(struct ip6_ext), -1);
 898                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 899 #else
 900                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 901                                     eoff, sizeof(*eh));
 902                                 if (eh == NULL) {
 903                                         icmp6stat.icp6s_tooshort++;
 904                                         return (-1);
 905                                 }
 906 #endif
 907
 908                                 if (nxt == IPPROTO_AH)
 909                                         eoff += (eh->ip6e_len + 2) << 2;
 910                                 else
 911                                         eoff += (eh->ip6e_len + 1) << 3;
 912                                 nxt = eh->ip6e_nxt;
 913                                 break;
 914                         case IPPROTO_ROUTING:
 915                                 /*
 916                                  * When the erroneous packet contains a
 917                                  * routing header, we should examine the
 918                                  * header to determine the final destination.
 919                                  * Otherwise, we can't properly update
 920                                  * information that depends on the final
 921                                  * destination (e.g. path MTU).
 922                                  */
 923 #ifndef PULLDOWN_TEST
 924                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 925                                 rth = (struct ip6_rthdr *)
 926                                     (mtod(m, caddr_t) + eoff);
 927 #else
 928                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 929                                     eoff, sizeof(*rth));
 930                                 if (rth == NULL) {
 931                                         icmp6stat.icp6s_tooshort++;
 932                                         return (-1);
 933                                 }
 934 #endif
 935                                 rthlen = (rth->ip6r_len + 1) << 3;
 936                                 /*
 937                                  * XXX: currently there is no
 938                                  * officially defined type other
 939                                  * than type-0.
 940                                  * Note that if the segment left field
 941                                  * is 0, all intermediate hops must
 942                                  * have been passed.
 943                                  */
 944                                 if (rth->ip6r_segleft &&
 945                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 946                                         int hops;
 947
 948 #ifndef PULLDOWN_TEST
 949                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 950                                         rth0 = (struct ip6_rthdr0 *)
 951                                             (mtod(m, caddr_t) + eoff);
 952 #else
 953                                         IP6_EXTHDR_GET(rth0,
 954                                             struct ip6_rthdr0 *, m,
 955                                             eoff, rthlen);
 956                                         if (rth0 == NULL) {
 957                                                 icmp6stat.icp6s_tooshort++;
 958                                                 return (-1);
 959                                         }
 960 #endif
 961                                         /* just ignore a bogus header */
 962                                         if ((rth0->ip6r0_len % 2) == 0 &&
 963                                             (hops = rth0->ip6r0_len/2))
 964                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 965                                 }
 966                                 eoff += rthlen;
 967                                 nxt = rth->ip6r_nxt;
 968                                 break;
 969                         case IPPROTO_FRAGMENT:
 970 #ifndef PULLDOWN_TEST
 971                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 972                                     sizeof(struct ip6_frag), -1);
 973                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
 974                                     eoff);
 975 #else
 976                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
 977                                     eoff, sizeof(*fh));
 978                                 if (fh == NULL) {
 979                                         icmp6stat.icp6s_tooshort++;
 980                                         return (-1);
 981                                 }
 982 #endif
 983                                 /*
 984                                  * Data after a fragment header is meaningless
 985                                  * unless it is the first fragment, but
 986                                  * we'll go to the notify label for path MTU
 987                                  * discovery.
 988                                  */
 989                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
 990                                         goto notify;
 991
 992                                 eoff += sizeof(struct ip6_frag);
 993                                 nxt = fh->ip6f_nxt;
 994                                 break;
 995                         default:
 996                                 /*
 997                                  * This case includes ESP and the No Next
 998                                  * Header.  In such cases going to the notify
 999                                  * label does not have any meaning
1000                                  * (i.e. ctlfunc will be NULL), but we go
1001                                  * anyway since we might have to update
1002                                  * path MTU information.
1003                                  */
1004                                 goto notify;
1005                         }
1006                 }
1007           notify:
1008 #ifndef PULLDOWN_TEST
1009                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1010 #else
1011                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1012                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1013                 if (icmp6 == NULL) {
1014                         icmp6stat.icp6s_tooshort++;
1015                         return (-1);
1016                 }
1017 #endif
1018
1019                 /*
1020                  * retrieve parameters from the inner IPv6 header, and convert
1021                  * them into sockaddr structures.
1022                  * XXX: there is no guarantee that the source or destination
1023                  * addresses of the inner packet are in the same scope as
1024                  * the addresses of the icmp packet.  But there is no other
1025                  * way to determine the zone.
1026                  */
1027                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1028
1029                 bzero(&icmp6dst, sizeof(icmp6dst));
1030                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1031                 icmp6dst.sin6_family = AF_INET6;
1032                 if (finaldst == NULL)
1033                         icmp6dst.sin6_addr = eip6->ip6_dst;
1034                 else
1035                         icmp6dst.sin6_addr = *finaldst;
1036                 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6dst.sin6_addr,
1037                     &icmp6dst.sin6_scope_id))
1038                         goto freeit;
1039                 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1040                                    NULL, NULL)) {
1041                         /* should be impossbile */
1042                         nd6log((LOG_DEBUG,
1043                             "icmp6_notify_error: in6_embedscope failed\n"));
1044                         goto freeit;
1045                 }
1046
1047                 /*
1048                  * retrieve parameters from the inner IPv6 header, and convert
1049                  * them into sockaddr structures.
1050                  */
1051                 bzero(&icmp6src, sizeof(icmp6src));
1052                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1053                 icmp6src.sin6_family = AF_INET6;
1054                 icmp6src.sin6_addr = eip6->ip6_src;
1055                 if (in6_addr2zoneid(m->m_pkthdr.rcvif, &icmp6src.sin6_addr,
1056                     &icmp6src.sin6_scope_id)) {
1057                         goto freeit;
1058                 }
1059                 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1060                                    NULL, NULL)) {
1061                         /* should be impossbile */
1062                         nd6log((LOG_DEBUG,
1063                             "icmp6_notify_error: in6_embedscope failed\n"));
1064                         goto freeit;
1065                 }
1066                 icmp6src.sin6_flowinfo = (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1067
1068                 if (finaldst == NULL)
1069                         finaldst = &eip6->ip6_dst;
1070                 ip6cp.ip6c_m = m;
1071                 ip6cp.ip6c_icmp6 = icmp6;
1072                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1073                 ip6cp.ip6c_off = eoff;
1074                 ip6cp.ip6c_finaldst = finaldst;
1075                 ip6cp.ip6c_src = &icmp6src;
1076                 ip6cp.ip6c_nxt = nxt;
1077
1078                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1079                         notifymtu = ntohl(icmp6->icmp6_mtu);
1080                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1081                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1082                 }
1083
1084                 ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1085                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1086                 if (ctlfunc) {
1087                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1088                             &ip6cp);
1089                 }
1090         }
1091         return (0);
1092
1093   freeit:
1094         m_freem(m);
1095         return (-1);
1096 }
1097
1098 void
1099 icmp6_mtudisc_update(ip6cp, validated)
1100         struct ip6ctlparam *ip6cp;
1101         int validated;
1102 {
1103         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1104         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1105         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1106         u_int mtu = ntohl(icmp6->icmp6_mtu);
1107         struct in_conninfo inc;
1108
1109 #if 0
1110         /*
1111          * RFC2460 section 5, last paragraph.
1112          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1113          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1114          * due to packet translator in the middle.
1115          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1116          * special handling.
1117          */
1118         if (mtu < IPV6_MMTU)
1119                 return;
1120 #endif
1121
1122         /*
1123          * we reject ICMPv6 too big with abnormally small value.
1124          * XXX what is the good definition of "abnormally small"?
1125          */
1126         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1127                 return;
1128
1129         if (!validated)
1130                 return;
1131
1132         bzero(&inc, sizeof(inc));
1133         inc.inc_flags = 1; /* IPv6 */
1134         inc.inc6_faddr = *dst;
1135         /* XXX normally, this won't happen */
1136         if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1137                 inc.inc6_faddr.s6_addr16[1] =
1138                     htons(m->m_pkthdr.rcvif->if_index);
1139         }
1140
1141         if (mtu < tcp_maxmtu6(&inc)) {
1142                 tcp_hc_updatemtu(&inc, mtu);
1143                 icmp6stat.icp6s_pmtuchg++;
1144         }
1145 }
1146
1147 /*
1148  * Process a Node Information Query packet, based on
1149  * draft-ietf-ipngwg-icmp-name-lookups-07.
1150  *
1151  * Spec incompatibilities:
1152  * - IPv6 Subject address handling
1153  * - IPv4 Subject address handling support missing
1154  * - Proxy reply (answer even if it's not for me)
1155  * - joins NI group address at in6_ifattach() time only, does not cope
1156  *   with hostname changes by sethostname(3)
1157  */
1158 #define hostnamelen     strlen(hostname)
1159 static struct mbuf *
1160 ni6_input(m, off)
1161         struct mbuf *m;
1162         int off;
1163 {
1164         struct icmp6_nodeinfo *ni6, *nni6;
1165         struct mbuf *n = NULL;
1166         u_int16_t qtype;
1167         int subjlen;
1168         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1169         struct ni_reply_fqdn *fqdn;
1170         int addrs;              /* for NI_QTYPE_NODEADDR */
1171         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1172         struct sockaddr_in6 sin6_sbj; /* subject address */
1173         struct sockaddr_in6 sin6_d;
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         bzero(&sin6_d, sizeof(sin6_d));
1191         sin6_d.sin6_family = AF_INET6; /* not used, actually */
1192         sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
1193         sin6_d.sin6_addr = ip6->ip6_dst;
1194         if (in6_addr2zoneid(m->m_pkthdr.rcvif, &ip6->ip6_dst,
1195             &sin6_d.sin6_scope_id)) {
1196                 goto bad;
1197         }
1198         if (in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL))
1199                 goto bad; /* XXX should not happen */
1200
1201         /*
1202          * Validate IPv6 destination address.
1203          *
1204          * The Responder must discard the Query without further processing
1205          * unless it is one of the Responder's unicast or anycast addresses, or
1206          * a link-local scope multicast address which the Responder has joined.
1207          * [icmp-name-lookups-08, Section 4.]
1208          */
1209         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1210                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1211                         goto bad;
1212                 /* else it's a link-local multicast, fine */
1213         } else {                /* unicast or anycast */
1214                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1215                         goto bad; /* XXX impossible */
1216
1217                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1218                     !(icmp6_nodeinfo & 4)) {
1219                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1220                                 "a temporary address in %s:%d",
1221                                __FILE__, __LINE__));
1222                         goto bad;
1223                 }
1224         }
1225
1226         /* validate query Subject field. */
1227         qtype = ntohs(ni6->ni_qtype);
1228         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1229         switch (qtype) {
1230         case NI_QTYPE_NOOP:
1231         case NI_QTYPE_SUPTYPES:
1232                 /* 07 draft */
1233                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1234                         break;
1235                 /* FALLTHROUGH */
1236         case NI_QTYPE_FQDN:
1237         case NI_QTYPE_NODEADDR:
1238                 switch (ni6->ni_code) {
1239                 case ICMP6_NI_SUBJ_IPV6:
1240 #if ICMP6_NI_SUBJ_IPV6 != 0
1241                 case 0:
1242 #endif
1243                         /*
1244                          * backward compatibility - try to accept 03 draft
1245                          * format, where no Subject is present.
1246                          */
1247                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1248                             subjlen == 0) {
1249                                 oldfqdn++;
1250                                 break;
1251                         }
1252 #if ICMP6_NI_SUBJ_IPV6 != 0
1253                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1254                                 goto bad;
1255 #endif
1256
1257                         if (subjlen != sizeof(struct in6_addr))
1258                                 goto bad;
1259
1260                         /*
1261                          * Validate Subject address.
1262                          *
1263                          * Not sure what exactly "address belongs to the node"
1264                          * means in the spec, is it just unicast, or what?
1265                          *
1266                          * At this moment we consider Subject address as
1267                          * "belong to the node" if the Subject address equals
1268                          * to the IPv6 destination address; validation for
1269                          * IPv6 destination address should have done enough
1270                          * check for us.
1271                          *
1272                          * We do not do proxy at this moment.
1273                          */
1274                         /* m_pulldown instead of copy? */
1275                         bzero(&sin6_sbj, sizeof(sin6_sbj));
1276                         sin6_sbj.sin6_family = AF_INET6;
1277                         sin6_sbj.sin6_len = sizeof(sin6_sbj);
1278                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1279                             subjlen, (caddr_t)&sin6_sbj.sin6_addr);
1280                         if (in6_addr2zoneid(m->m_pkthdr.rcvif,
1281                             &sin6_sbj.sin6_addr, &sin6_sbj.sin6_scope_id)) {
1282                                 goto bad;
1283                         }
1284                         if (in6_embedscope(&sin6_sbj.sin6_addr, &sin6_sbj,
1285                             NULL, NULL))
1286                                 goto bad; /* XXX should not happen */
1287
1288                         subj = (char *)&sin6_sbj;
1289                         if (SA6_ARE_ADDR_EQUAL(&sin6_sbj, &sin6_d))
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 & 1) == 0)
1341                         goto bad;
1342                 break;
1343         case NI_QTYPE_NODEADDR:
1344                 if ((icmp6_nodeinfo & 2) == 0)
1345                         goto bad;
1346                 break;
1347         }
1348
1349         /* guess reply length */
1350         switch (qtype) {
1351         case NI_QTYPE_NOOP:
1352                 break;          /* no reply data */
1353         case NI_QTYPE_SUPTYPES:
1354                 replylen += sizeof(u_int32_t);
1355                 break;
1356         case NI_QTYPE_FQDN:
1357                 /* XXX will append an mbuf */
1358                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1359                 break;
1360         case NI_QTYPE_NODEADDR:
1361                 addrs = ni6_addrs(ni6, m, &ifp, subj);
1362                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1363                     sizeof(u_int32_t))) > MCLBYTES)
1364                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1365                 break;
1366         default:
1367                 /*
1368                  * XXX: We must return a reply with the ICMP6 code
1369                  * `unknown Qtype' in this case.  However we regard the case
1370                  * as an FQDN query for backward compatibility.
1371                  * Older versions set a random value to this field,
1372                  * so it rarely varies in the defined qtypes.
1373                  * But the mechanism is not reliable...
1374                  * maybe we should obsolete older versions.
1375                  */
1376                 qtype = NI_QTYPE_FQDN;
1377                 /* XXX will append an mbuf */
1378                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1379                 oldfqdn++;
1380                 break;
1381         }
1382
1383         /* allocate an mbuf to reply. */
1384         MGETHDR(n, M_DONTWAIT, m->m_type);
1385         if (n == NULL) {
1386                 m_freem(m);
1387                 return (NULL);
1388         }
1389         M_MOVE_PKTHDR(n, m); /* just for recvif */
1390         if (replylen > MHLEN) {
1391                 if (replylen > MCLBYTES) {
1392                         /*
1393                          * XXX: should we try to allocate more? But MCLBYTES
1394                          * is probably much larger than IPV6_MMTU...
1395                          */
1396                         goto bad;
1397                 }
1398                 MCLGET(n, M_DONTWAIT);
1399                 if ((n->m_flags & M_EXT) == 0) {
1400                         goto bad;
1401                 }
1402         }
1403         n->m_pkthdr.len = n->m_len = replylen;
1404
1405         /* copy mbuf header and IPv6 + Node Information base headers */
1406         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1407         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1408         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1409
1410         /* qtype dependent procedure */
1411         switch (qtype) {
1412         case NI_QTYPE_NOOP:
1413                 nni6->ni_code = ICMP6_NI_SUCCESS;
1414                 nni6->ni_flags = 0;
1415                 break;
1416         case NI_QTYPE_SUPTYPES:
1417         {
1418                 u_int32_t v;
1419                 nni6->ni_code = ICMP6_NI_SUCCESS;
1420                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1421                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1422                 v = (u_int32_t)htonl(0x0000000f);
1423                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1424                 break;
1425         }
1426         case NI_QTYPE_FQDN:
1427                 nni6->ni_code = ICMP6_NI_SUCCESS;
1428                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1429                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1430                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1431                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1432                 /*
1433                  * XXX do we really have FQDN in variable "hostname"?
1434                  */
1435                 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1436                 if (n->m_next == NULL)
1437                         goto bad;
1438                 /* XXX we assume that n->m_next is not a chain */
1439                 if (n->m_next->m_next != NULL)
1440                         goto bad;
1441                 n->m_pkthdr.len += n->m_next->m_len;
1442                 break;
1443         case NI_QTYPE_NODEADDR:
1444         {
1445                 int lenlim, copied;
1446
1447                 nni6->ni_code = ICMP6_NI_SUCCESS;
1448                 n->m_pkthdr.len = n->m_len =
1449                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1450                 lenlim = M_TRAILINGSPACE(n);
1451                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1452                 /* XXX: reset mbuf length */
1453                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1454                     sizeof(struct icmp6_nodeinfo) + copied;
1455                 break;
1456         }
1457         default:
1458                 break;          /* XXX impossible! */
1459         }
1460
1461         nni6->ni_type = ICMP6_NI_REPLY;
1462         m_freem(m);
1463         return (n);
1464
1465   bad:
1466         m_freem(m);
1467         if (n)
1468                 m_freem(n);
1469         return (NULL);
1470 }
1471 #undef hostnamelen
1472
1473 /*
1474  * make a mbuf with DNS-encoded string.  no compression support.
1475  *
1476  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1477  * treated as truncated name (two \0 at the end).  this is a wild guess.
1478  */
1479 static struct mbuf *
1480 ni6_nametodns(name, namelen, old)
1481         const char *name;
1482         int namelen;
1483         int old;        /* return pascal string if non-zero */
1484 {
1485         struct mbuf *m;
1486         char *cp, *ep;
1487         const char *p, *q;
1488         int i, len, nterm;
1489
1490         if (old)
1491                 len = namelen + 1;
1492         else
1493                 len = MCLBYTES;
1494
1495         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1496         MGET(m, M_DONTWAIT, MT_DATA);
1497         if (m && len > MLEN) {
1498                 MCLGET(m, M_DONTWAIT);
1499                 if ((m->m_flags & M_EXT) == 0)
1500                         goto fail;
1501         }
1502         if (!m)
1503                 goto fail;
1504         m->m_next = NULL;
1505
1506         if (old) {
1507                 m->m_len = len;
1508                 *mtod(m, char *) = namelen;
1509                 bcopy(name, mtod(m, char *) + 1, namelen);
1510                 return m;
1511         } else {
1512                 m->m_len = 0;
1513                 cp = mtod(m, char *);
1514                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1515
1516                 /* if not certain about my name, return empty buffer */
1517                 if (namelen == 0)
1518                         return m;
1519
1520                 /*
1521                  * guess if it looks like shortened hostname, or FQDN.
1522                  * shortened hostname needs two trailing "\0".
1523                  */
1524                 i = 0;
1525                 for (p = name; p < name + namelen; p++) {
1526                         if (*p && *p == '.')
1527                                 i++;
1528                 }
1529                 if (i < 2)
1530                         nterm = 2;
1531                 else
1532                         nterm = 1;
1533
1534                 p = name;
1535                 while (cp < ep && p < name + namelen) {
1536                         i = 0;
1537                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1538                                 i++;
1539                         /* result does not fit into mbuf */
1540                         if (cp + i + 1 >= ep)
1541                                 goto fail;
1542                         /*
1543                          * DNS label length restriction, RFC1035 page 8.
1544                          * "i == 0" case is included here to avoid returning
1545                          * 0-length label on "foo..bar".
1546                          */
1547                         if (i <= 0 || i >= 64)
1548                                 goto fail;
1549                         *cp++ = i;
1550                         bcopy(p, cp, i);
1551                         cp += i;
1552                         p = q;
1553                         if (p < name + namelen && *p == '.')
1554                                 p++;
1555                 }
1556                 /* termination */
1557                 if (cp + nterm >= ep)
1558                         goto fail;
1559                 while (nterm-- > 0)
1560                         *cp++ = '\0';
1561                 m->m_len = cp - mtod(m, char *);
1562                 return m;
1563         }
1564
1565         panic("should not reach here");
1566         /* NOTREACHED */
1567
1568  fail:
1569         if (m)
1570                 m_freem(m);
1571         return NULL;
1572 }
1573
1574 /*
1575  * check if two DNS-encoded string matches.  takes care of truncated
1576  * form (with \0\0 at the end).  no compression support.
1577  * XXX upper/lowercase match (see RFC2065)
1578  */
1579 static int
1580 ni6_dnsmatch(a, alen, b, blen)
1581         const char *a;
1582         int alen;
1583         const char *b;
1584         int blen;
1585 {
1586         const char *a0, *b0;
1587         int l;
1588
1589         /* simplest case - need validation? */
1590         if (alen == blen && bcmp(a, b, alen) == 0)
1591                 return 1;
1592
1593         a0 = a;
1594         b0 = b;
1595
1596         /* termination is mandatory */
1597         if (alen < 2 || blen < 2)
1598                 return 0;
1599         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1600                 return 0;
1601         alen--;
1602         blen--;
1603
1604         while (a - a0 < alen && b - b0 < blen) {
1605                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1606                         return 0;
1607
1608                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1609                         return 0;
1610                 /* we don't support compression yet */
1611                 if (a[0] >= 64 || b[0] >= 64)
1612                         return 0;
1613
1614                 /* truncated case */
1615                 if (a[0] == 0 && a - a0 == alen - 1)
1616                         return 1;
1617                 if (b[0] == 0 && b - b0 == blen - 1)
1618                         return 1;
1619                 if (a[0] == 0 || b[0] == 0)
1620                         return 0;
1621
1622                 if (a[0] != b[0])
1623                         return 0;
1624                 l = a[0];
1625                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1626                         return 0;
1627                 if (bcmp(a + 1, b + 1, l) != 0)
1628                         return 0;
1629
1630                 a += 1 + l;
1631                 b += 1 + l;
1632         }
1633
1634         if (a - a0 == alen && b - b0 == blen)
1635                 return 1;
1636         else
1637                 return 0;
1638 }
1639
1640 /*
1641  * calculate the number of addresses to be returned in the node info reply.
1642  */
1643 static int
1644 ni6_addrs(ni6, m, ifpp, subj)
1645         struct icmp6_nodeinfo *ni6;
1646         struct mbuf *m;
1647         struct ifnet **ifpp;
1648         char *subj;
1649 {
1650         struct ifnet *ifp;
1651         struct in6_ifaddr *ifa6;
1652         struct ifaddr *ifa;
1653         struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1654         int addrs = 0, addrsofif, iffound = 0;
1655         int niflags = ni6->ni_flags;
1656
1657         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1658                 switch (ni6->ni_code) {
1659                 case ICMP6_NI_SUBJ_IPV6:
1660                         if (subj == NULL) /* must be impossible... */
1661                                 return (0);
1662                         subj_ip6 = (struct sockaddr_in6 *)subj;
1663                         break;
1664                 default:
1665                         /*
1666                          * XXX: we only support IPv6 subject address for
1667                          * this Qtype.
1668                          */
1669                         return (0);
1670                 }
1671         }
1672
1673         IFNET_RLOCK();
1674         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1675                 addrsofif = 0;
1676                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1677                         if (ifa->ifa_addr->sa_family != AF_INET6)
1678                                 continue;
1679                         ifa6 = (struct in6_ifaddr *)ifa;
1680
1681                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1682                             IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1683                             &ifa6->ia_addr.sin6_addr))
1684                                 iffound = 1;
1685
1686                         /*
1687                          * IPv4-mapped addresses can only be returned by a
1688                          * Node Information proxy, since they represent
1689                          * addresses of IPv4-only nodes, which perforce do
1690                          * not implement this protocol.
1691                          * [icmp-name-lookups-07, Section 5.4]
1692                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1693                          * this function at this moment.
1694                          */
1695
1696                         /* What do we have to do about ::1? */
1697                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1698                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1699                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1700                                         continue;
1701                                 break;
1702                         case IPV6_ADDR_SCOPE_SITELOCAL:
1703                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1704                                         continue;
1705                                 break;
1706                         case IPV6_ADDR_SCOPE_GLOBAL:
1707                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1708                                         continue;
1709                                 break;
1710                         default:
1711                                 continue;
1712                         }
1713
1714                         /*
1715                          * check if anycast is okay.
1716                          * XXX: just experimental.  not in the spec.
1717                          */
1718                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1719                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1720                                 continue; /* we need only unicast addresses */
1721                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1722                             (icmp6_nodeinfo & 4) == 0) {
1723                                 continue;
1724                         }
1725                         addrsofif++; /* count the address */
1726                 }
1727                 if (iffound) {
1728                         *ifpp = ifp;
1729                         IFNET_RUNLOCK();
1730                         return (addrsofif);
1731                 }
1732
1733                 addrs += addrsofif;
1734         }
1735         IFNET_RUNLOCK();
1736
1737         return (addrs);
1738 }
1739
1740 static int
1741 ni6_store_addrs(ni6, nni6, ifp0, resid)
1742         struct icmp6_nodeinfo *ni6, *nni6;
1743         struct ifnet *ifp0;
1744         int resid;
1745 {
1746         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1747         struct in6_ifaddr *ifa6;
1748         struct ifaddr *ifa;
1749         struct ifnet *ifp_dep = NULL;
1750         int copied = 0, allow_deprecated = 0;
1751         u_char *cp = (u_char *)(nni6 + 1);
1752         int niflags = ni6->ni_flags;
1753         u_int32_t ltime;
1754
1755         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1756                 return (0);     /* needless to copy */
1757
1758         IFNET_RLOCK();
1759   again:
1760
1761         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1762                 for (ifa = ifp->if_addrlist.tqh_first; ifa;
1763                      ifa = ifa->ifa_list.tqe_next) {
1764                         if (ifa->ifa_addr->sa_family != AF_INET6)
1765                                 continue;
1766                         ifa6 = (struct in6_ifaddr *)ifa;
1767
1768                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1769                             allow_deprecated == 0) {
1770                                 /*
1771                                  * prefererred address should be put before
1772                                  * deprecated addresses.
1773                                  */
1774
1775                                 /* record the interface for later search */
1776                                 if (ifp_dep == NULL)
1777                                         ifp_dep = ifp;
1778
1779                                 continue;
1780                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1781                             allow_deprecated != 0)
1782                                 continue; /* we now collect deprecated addrs */
1783
1784                         /* What do we have to do about ::1? */
1785                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1786                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1787                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1788                                         continue;
1789                                 break;
1790                         case IPV6_ADDR_SCOPE_SITELOCAL:
1791                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1792                                         continue;
1793                                 break;
1794                         case IPV6_ADDR_SCOPE_GLOBAL:
1795                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1796                                         continue;
1797                                 break;
1798                         default:
1799                                 continue;
1800                         }
1801
1802                         /*
1803                          * check if anycast is okay.
1804                          * XXX: just experimental.  not in the spec.
1805                          */
1806                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1807                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1808                                 continue;
1809                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1810                             (icmp6_nodeinfo & 4) == 0) {
1811                                 continue;
1812                         }
1813
1814                         /* now we can copy the address */
1815                         if (resid < sizeof(struct in6_addr) +
1816                             sizeof(u_int32_t)) {
1817                                 /*
1818                                  * We give up much more copy.
1819                                  * Set the truncate flag and return.
1820                                  */
1821                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1822                                 IFNET_RUNLOCK();
1823                                 return (copied);
1824                         }
1825
1826                         /*
1827                          * Set the TTL of the address.
1828                          * The TTL value should be one of the following
1829                          * according to the specification:
1830                          *
1831                          * 1. The remaining lifetime of a DHCP lease on the
1832                          *    address, or
1833                          * 2. The remaining Valid Lifetime of a prefix from
1834                          *    which the address was derived through Stateless
1835                          *    Autoconfiguration.
1836                          *
1837                          * Note that we currently do not support stateful
1838                          * address configuration by DHCPv6, so the former
1839                          * case can't happen.
1840                          */
1841                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1842                                 ltime = ND6_INFINITE_LIFETIME;
1843                         else {
1844                                 if (ifa6->ia6_lifetime.ia6t_expire >
1845                                     time_second)
1846                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1847                                 else
1848                                         ltime = 0;
1849                         }
1850
1851                         bcopy(&ltime, cp, sizeof(u_int32_t));
1852                         cp += sizeof(u_int32_t);
1853
1854                         /* copy the address itself */
1855                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1856                             sizeof(struct in6_addr));
1857                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1858                         cp += sizeof(struct in6_addr);
1859
1860                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1861                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1862                 }
1863                 if (ifp0)       /* we need search only on the specified IF */
1864                         break;
1865         }
1866
1867         if (allow_deprecated == 0 && ifp_dep != NULL) {
1868                 ifp = ifp_dep;
1869                 allow_deprecated = 1;
1870
1871                 goto again;
1872         }
1873
1874         IFNET_RUNLOCK();
1875
1876         return (copied);
1877 }
1878
1879 /*
1880  * XXX almost dup'ed code with rip6_input.
1881  */
1882 static int
1883 icmp6_rip6_input(mp, off)
1884         struct  mbuf **mp;
1885         int     off;
1886 {
1887         struct mbuf *m = *mp;
1888         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1889         struct in6pcb *in6p;
1890         struct in6pcb *last = NULL;
1891         struct sockaddr_in6 fromsa;
1892         struct icmp6_hdr *icmp6;
1893         struct mbuf *opts = NULL;
1894
1895 #ifndef PULLDOWN_TEST
1896         /* this is assumed to be safe. */
1897         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1898 #else
1899         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1900         if (icmp6 == NULL) {
1901                 /* m is already reclaimed */
1902                 return (IPPROTO_DONE);
1903         }
1904 #endif
1905
1906         bzero(&fromsa, sizeof(fromsa));
1907         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1908         fromsa.sin6_family = AF_INET6;
1909         /* KAME hack: recover scopeid */
1910         (void)in6_recoverscope(&fromsa, &ip6->ip6_src, m->m_pkthdr.rcvif);
1911
1912         LIST_FOREACH(in6p, &ripcb, inp_list) {
1913                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1914                         continue;
1915                 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1916                         continue;
1917                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1918                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1919                         continue;
1920                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1921                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1922                         continue;
1923                 if (in6p->in6p_icmp6filt
1924                     && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1925                                  in6p->in6p_icmp6filt))
1926                         continue;
1927                 if (last) {
1928                         struct  mbuf *n = NULL;
1929
1930                         /*
1931                          * Recent network drivers tend to allocate a single
1932                          * mbuf cluster, rather than to make a couple of
1933                          * mbufs without clusters.  Also, since the IPv6 code
1934                          * path tries to avoid m_pullup(), it is highly
1935                          * probable that we still have an mbuf cluster here
1936                          * even though the necessary length can be stored in an
1937                          * mbuf's internal buffer.
1938                          * Meanwhile, the default size of the receive socket
1939                          * buffer for raw sockets is not so large.  This means
1940                          * the possibility of packet loss is relatively higher
1941                          * than before.  To avoid this scenario, we copy the
1942                          * received data to a separate mbuf that does not use
1943                          * a cluster, if possible.
1944                          * XXX: it is better to copy the data after stripping
1945                          * intermediate headers.
1946                          */
1947                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1948                             m->m_len <= MHLEN) {
1949                                 MGET(n, M_DONTWAIT, m->m_type);
1950                                 if (n != NULL) {
1951                                         m_dup_pkthdr(n, m, M_NOWAIT);
1952                                         bcopy(m->m_data, n->m_data, m->m_len);
1953                                         n->m_len = m->m_len;
1954                                 }
1955                         }
1956                         if (n != NULL ||
1957                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1958                                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1959                                         ip6_savecontrol(last, n, &opts);
1960                                 /* strip intermediate headers */
1961                                 m_adj(n, off);
1962                                 if (sbappendaddr(&last->in6p_socket->so_rcv,
1963                                     (struct sockaddr *)&fromsa, n, opts)
1964                                     == 0) {
1965                                         /* should notify about lost packet */
1966                                         m_freem(n);
1967                                         if (opts) {
1968                                                 m_freem(opts);
1969                                         }
1970                                 } else
1971                                         sorwakeup(last->in6p_socket);
1972                                 opts = NULL;
1973                         }
1974                 }
1975                 last = in6p;
1976         }
1977         if (last) {
1978                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1979                         ip6_savecontrol(last, m, &opts);
1980                 /* strip intermediate headers */
1981                 m_adj(m, off);
1982
1983                 /* avoid using mbuf clusters if possible (see above) */
1984                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1985                     m->m_len <= MHLEN) {
1986                         struct mbuf *n;
1987
1988                         MGET(n, M_DONTWAIT, m->m_type);
1989                         if (n != NULL) {
1990                                 m_dup_pkthdr(n, m, M_NOWAIT);
1991                                 bcopy(m->m_data, n->m_data, m->m_len);
1992                                 n->m_len = m->m_len;
1993
1994                                 m_freem(m);
1995                                 m = n;
1996                         }
1997                 }
1998                 if (sbappendaddr(&last->in6p_socket->so_rcv,
1999                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2000                         m_freem(m);
2001                         if (opts)
2002                                 m_freem(opts);
2003                 } else
2004                         sorwakeup(last->in6p_socket);
2005         } else {
2006                 m_freem(m);
2007                 ip6stat.ip6s_delivered--;
2008         }
2009         return IPPROTO_DONE;
2010 }
2011
2012 /*
2013  * Reflect the ip6 packet back to the source.
2014  * OFF points to the icmp6 header, counted from the top of the mbuf.
2015  */
2016 void
2017 icmp6_reflect(m, off)
2018         struct  mbuf *m;
2019         size_t off;
2020 {
2021         struct ip6_hdr *ip6;
2022         struct icmp6_hdr *icmp6;
2023         struct in6_ifaddr *ia;
2024         struct in6_addr t, *src = 0;
2025         int plen;
2026         int type, code;
2027         struct ifnet *outif = NULL;
2028         struct sockaddr_in6 sa6_src, sa6_dst;
2029 #ifdef COMPAT_RFC1885
2030         int mtu = IPV6_MMTU;
2031         struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
2032 #endif
2033
2034         /* too short to reflect */
2035         if (off < sizeof(struct ip6_hdr)) {
2036                 nd6log((LOG_DEBUG,
2037                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2038                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2039                     __FILE__, __LINE__));
2040                 goto bad;
2041         }
2042
2043         /*
2044          * If there are extra headers between IPv6 and ICMPv6, strip
2045          * off that header first.
2046          */
2047 #ifdef DIAGNOSTIC
2048         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2049                 panic("assumption failed in icmp6_reflect");
2050 #endif
2051         if (off > sizeof(struct ip6_hdr)) {
2052                 size_t l;
2053                 struct ip6_hdr nip6;
2054
2055                 l = off - sizeof(struct ip6_hdr);
2056                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2057                 m_adj(m, l);
2058                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2059                 if (m->m_len < l) {
2060                         if ((m = m_pullup(m, l)) == NULL)
2061                                 return;
2062                 }
2063                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2064         } else /* off == sizeof(struct ip6_hdr) */ {
2065                 size_t l;
2066                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2067                 if (m->m_len < l) {
2068                         if ((m = m_pullup(m, l)) == NULL)
2069                                 return;
2070                 }
2071         }
2072         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2073         ip6 = mtod(m, struct ip6_hdr *);
2074         ip6->ip6_nxt = IPPROTO_ICMPV6;
2075         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2076         type = icmp6->icmp6_type; /* keep type for statistics */
2077         code = icmp6->icmp6_code; /* ditto. */
2078
2079         t = ip6->ip6_dst;
2080         /*
2081          * ip6_input() drops a packet if its src is multicast.
2082          * So, the src is never multicast.
2083          */
2084         ip6->ip6_dst = ip6->ip6_src;
2085
2086         /*
2087          * XXX: make sure to embed scope zone information, using
2088          * already embedded IDs or the received interface (if any).
2089          * Note that rcvif may be NULL.
2090          * TODO: scoped routing case (XXX).
2091          */
2092         bzero(&sa6_src, sizeof(sa6_src));
2093         sa6_src.sin6_family = AF_INET6;
2094         sa6_src.sin6_len = sizeof(sa6_src);
2095         sa6_src.sin6_addr = ip6->ip6_dst;
2096         in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
2097         in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
2098         bzero(&sa6_dst, sizeof(sa6_dst));
2099         sa6_dst.sin6_family = AF_INET6;
2100         sa6_dst.sin6_len = sizeof(sa6_dst);
2101         sa6_dst.sin6_addr = t;
2102         in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2103         in6_embedscope(&t, &sa6_dst, NULL, NULL);
2104
2105 #ifdef COMPAT_RFC1885
2106         /*
2107          * xxx guess MTU
2108          * RFC 1885 requires that echo reply should be truncated if it
2109          * does not fit in with (return) path MTU, but the description was
2110          * removed in the new spec.
2111          */
2112         if (icmp6_reflect_rt.ro_rt == 0 ||
2113             ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
2114                 if (icmp6_reflect_rt.ro_rt) {
2115                         RTFREE(icmp6_reflect_rt.ro_rt);
2116                         icmp6_reflect_rt.ro_rt = 0;
2117                 }
2118                 bzero(sin6, sizeof(*sin6));
2119                 sin6->sin6_family = PF_INET6;
2120                 sin6->sin6_len = sizeof(struct sockaddr_in6);
2121                 sin6->sin6_addr = ip6->ip6_dst;
2122
2123                 rtalloc((struct route *)&icmp6_reflect_rt.ro_rt);
2124         }
2125
2126         if (icmp6_reflect_rt.ro_rt == 0)
2127                 goto bad;
2128
2129         if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2130             && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2131                 mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2132
2133         if (mtu < m->m_pkthdr.len) {
2134                 plen -= (m->m_pkthdr.len - mtu);
2135                 m_adj(m, mtu - m->m_pkthdr.len);
2136         }
2137 #endif
2138         /*
2139          * If the incoming packet was addressed directly to us (i.e. unicast),
2140          * use dst as the src for the reply.
2141          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2142          * (for example) when we encounter an error while forwarding procedure
2143          * destined to a duplicated address of ours.
2144          */
2145         for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2146                 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2147                     (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2148                         src = &t;
2149                         break;
2150                 }
2151         if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2152                 /*
2153                  * This is the case if the dst is our link-local address
2154                  * and the sender is also ourselves.
2155                  */
2156                 src = &t;
2157         }
2158
2159         if (src == 0) {
2160                 int e;
2161                 struct route_in6 ro;
2162
2163                 /*
2164                  * This case matches to multicasts, our anycast, or unicasts
2165                  * that we do not own.  Select a source address based on the
2166                  * source address of the erroneous packet.
2167                  */
2168                 bzero(&ro, sizeof(ro));
2169                 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e);
2170                 if (ro.ro_rt)
2171                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2172                 if (src == NULL) {
2173                         nd6log((LOG_DEBUG,
2174                             "icmp6_reflect: source can't be determined: "
2175                             "dst=%s, error=%d\n",
2176                             ip6_sprintf(&sa6_src.sin6_addr), e));
2177                         goto bad;
2178                 }
2179         }
2180
2181         ip6->ip6_src = *src;
2182
2183         ip6->ip6_flow = 0;
2184         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2185         ip6->ip6_vfc |= IPV6_VERSION;
2186         ip6->ip6_nxt = IPPROTO_ICMPV6;
2187         if (outif)
2188                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2189         else if (m->m_pkthdr.rcvif) {
2190                 /* XXX: This may not be the outgoing interface */
2191                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2192         } else
2193                 ip6->ip6_hlim = ip6_defhlim;
2194
2195         icmp6->icmp6_cksum = 0;
2196         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2197             sizeof(struct ip6_hdr), plen);
2198
2199         /*
2200          * XXX option handling
2201          */
2202
2203         m->m_flags &= ~(M_BCAST|M_MCAST);
2204
2205 #ifdef COMPAT_RFC1885
2206         ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL);
2207 #else
2208         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2209 #endif
2210         if (outif)
2211                 icmp6_ifoutstat_inc(outif, type, code);
2212
2213         return;
2214
2215  bad:
2216         m_freem(m);
2217         return;
2218 }
2219
2220 void
2221 icmp6_fasttimo()
2222 {
2223
2224         mld6_fasttimeo();
2225 }
2226
2227 static const char *
2228 icmp6_redirect_diag(src6, dst6, tgt6)
2229         struct in6_addr *src6;
2230         struct in6_addr *dst6;
2231         struct in6_addr *tgt6;
2232 {
2233         static char buf[1024];
2234         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2235             ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2236         return buf;
2237 }
2238
2239 void
2240 icmp6_redirect_input(m, off)
2241         struct mbuf *m;
2242         int off;
2243 {
2244         struct ifnet *ifp = m->m_pkthdr.rcvif;
2245         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2246         struct nd_redirect *nd_rd;
2247         int icmp6len = ntohs(ip6->ip6_plen);
2248         char *lladdr = NULL;
2249         int lladdrlen = 0;
2250         u_char *redirhdr = NULL;
2251         int redirhdrlen = 0;
2252         struct rtentry *rt = NULL;
2253         int is_router;
2254         int is_onlink;
2255         struct in6_addr src6 = ip6->ip6_src;
2256         struct in6_addr redtgt6;
2257         struct in6_addr reddst6;
2258         union nd_opts ndopts;
2259
2260         if (!m || !ifp)
2261                 return;
2262
2263         /* XXX if we are router, we don't update route by icmp6 redirect */
2264         if (ip6_forwarding)
2265                 goto freeit;
2266         if (!icmp6_rediraccept)
2267                 goto freeit;
2268
2269 #ifndef PULLDOWN_TEST
2270         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2271         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2272 #else
2273         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2274         if (nd_rd == NULL) {
2275                 icmp6stat.icp6s_tooshort++;
2276                 return;
2277         }
2278 #endif
2279         redtgt6 = nd_rd->nd_rd_target;
2280         reddst6 = nd_rd->nd_rd_dst;
2281
2282         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2283                 redtgt6.s6_addr16[1] = htons(ifp->if_index);
2284         if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2285                 reddst6.s6_addr16[1] = htons(ifp->if_index);
2286
2287         /* validation */
2288         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2289                 nd6log((LOG_ERR,
2290                     "ICMP6 redirect sent from %s rejected; "
2291                     "must be from linklocal\n",
2292                     ip6_sprintf(&src6)));
2293                 goto bad;
2294         }
2295         if (ip6->ip6_hlim != 255) {
2296                 nd6log((LOG_ERR,
2297                     "ICMP6 redirect sent from %s rejected; "
2298                     "hlim=%d (must be 255)\n",
2299                     ip6_sprintf(&src6), ip6->ip6_hlim));
2300                 goto bad;
2301         }
2302     {
2303         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2304         struct sockaddr_in6 sin6;
2305         struct in6_addr *gw6;
2306
2307         bzero(&sin6, sizeof(sin6));
2308         sin6.sin6_family = AF_INET6;
2309         sin6.sin6_len = sizeof(struct sockaddr_in6);
2310         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2311         rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2312         if (rt) {
2313                 if (rt->rt_gateway == NULL ||
2314                     rt->rt_gateway->sa_family != AF_INET6) {
2315                         nd6log((LOG_ERR,
2316                             "ICMP6 redirect rejected; no route "
2317                             "with inet6 gateway found for redirect dst: %s\n",
2318                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2319                         RTFREE_LOCKED(rt);
2320                         goto bad;
2321                 }
2322
2323                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2324                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2325                         nd6log((LOG_ERR,
2326                             "ICMP6 redirect rejected; "
2327                             "not equal to gw-for-src=%s (must be same): "
2328                             "%s\n",
2329                             ip6_sprintf(gw6),
2330                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2331                         RTFREE_LOCKED(rt);
2332                         goto bad;
2333                 }
2334         } else {
2335                 nd6log((LOG_ERR,
2336                     "ICMP6 redirect rejected; "
2337                     "no route found for redirect dst: %s\n",
2338                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2339                 goto bad;
2340         }
2341         RTFREE_LOCKED(rt);
2342         rt = NULL;
2343     }
2344         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2345                 nd6log((LOG_ERR,
2346                     "ICMP6 redirect rejected; "
2347                     "redirect dst must be unicast: %s\n",
2348                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2349                 goto bad;
2350         }
2351
2352         is_router = is_onlink = 0;
2353         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2354                 is_router = 1;  /* router case */
2355         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2356                 is_onlink = 1;  /* on-link destination case */
2357         if (!is_router && !is_onlink) {
2358                 nd6log((LOG_ERR,
2359                     "ICMP6 redirect rejected; "
2360                     "neither router case nor onlink case: %s\n",
2361                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2362                 goto bad;
2363         }
2364         /* validation passed */
2365
2366         icmp6len -= sizeof(*nd_rd);
2367         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2368         if (nd6_options(&ndopts) < 0) {
2369                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2370                     "invalid ND option, rejected: %s\n",
2371                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2372                 /* nd6_options have incremented stats */
2373                 goto freeit;
2374         }
2375
2376         if (ndopts.nd_opts_tgt_lladdr) {
2377                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2378                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2379         }
2380
2381         if (ndopts.nd_opts_rh) {
2382                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2383                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2384         }
2385
2386         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2387                 nd6log((LOG_INFO,
2388                     "icmp6_redirect_input: lladdrlen mismatch for %s "
2389                     "(if %d, icmp6 packet %d): %s\n",
2390                     ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2391                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2392                 goto bad;
2393         }
2394
2395         /* RFC 2461 8.3 */
2396         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2397             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2398
2399         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2400                 /* perform rtredirect */
2401                 struct sockaddr_in6 sdst;
2402                 struct sockaddr_in6 sgw;
2403                 struct sockaddr_in6 ssrc;
2404
2405                 bzero(&sdst, sizeof(sdst));
2406                 bzero(&sgw, sizeof(sgw));
2407                 bzero(&ssrc, sizeof(ssrc));
2408                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2409                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2410                         sizeof(struct sockaddr_in6);
2411                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2412                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2413                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2414                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2415                     (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2416                     (struct sockaddr *)&ssrc);
2417         }
2418         /* finally update cached route in each socket via pfctlinput */
2419     {
2420         struct sockaddr_in6 sdst;
2421
2422         bzero(&sdst, sizeof(sdst));
2423         sdst.sin6_family = AF_INET6;
2424         sdst.sin6_len = sizeof(struct sockaddr_in6);
2425         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2426         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2427 #if defined(IPSEC) || defined(FAST_IPSEC)
2428         key_sa_routechange((struct sockaddr *)&sdst);
2429 #endif
2430     }
2431
2432  freeit:
2433         m_freem(m);
2434         return;
2435
2436  bad:
2437         icmp6stat.icp6s_badredirect++;
2438         m_freem(m);
2439 }
2440
2441 void
2442 icmp6_redirect_output(m0, rt)
2443         struct mbuf *m0;
2444         struct rtentry *rt;
2445 {
2446         struct ifnet *ifp;      /* my outgoing interface */
2447         struct in6_addr *ifp_ll6;
2448         struct in6_addr *router_ll6;
2449         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2450         struct mbuf *m = NULL;  /* newly allocated one */
2451         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2452         struct nd_redirect *nd_rd;
2453         size_t maxlen;
2454         u_char *p;
2455         struct ifnet *outif = NULL;
2456         struct sockaddr_in6 src_sa;
2457
2458         icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2459
2460         /* if we are not router, we don't send icmp6 redirect */
2461         if (!ip6_forwarding || ip6_accept_rtadv)
2462                 goto fail;
2463
2464         /* sanity check */
2465         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2466                 goto fail;
2467
2468         /*
2469          * Address check:
2470          *  the source address must identify a neighbor, and
2471          *  the destination address must not be a multicast address
2472          *  [RFC 2461, sec 8.2]
2473          */
2474         sip6 = mtod(m0, struct ip6_hdr *);
2475         bzero(&src_sa, sizeof(src_sa));
2476         src_sa.sin6_family = AF_INET6;
2477         src_sa.sin6_len = sizeof(src_sa);
2478         src_sa.sin6_addr = sip6->ip6_src;
2479         /* we don't currently use sin6_scope_id, but eventually use it */
2480         if (in6_addr2zoneid(ifp, &sip6->ip6_src, &src_sa.sin6_scope_id))
2481                 goto fail;
2482         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2483                 goto fail;
2484         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2485                 goto fail;      /* what should we do here? */
2486
2487         /* rate limit */
2488         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2489                 goto fail;
2490
2491         /*
2492          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2493          * we almost always ask for an mbuf cluster for simplicity.
2494          * (MHLEN < IPV6_MMTU is almost always true)
2495          */
2496 #if IPV6_MMTU >= MCLBYTES
2497 # error assumption failed about IPV6_MMTU and MCLBYTES
2498 #endif
2499         MGETHDR(m, M_DONTWAIT, MT_HEADER);
2500         if (m && IPV6_MMTU >= MHLEN)
2501                 MCLGET(m, M_DONTWAIT);
2502         if (!m)
2503                 goto fail;
2504         m->m_pkthdr.rcvif = NULL;
2505         m->m_len = 0;
2506         maxlen = M_TRAILINGSPACE(m);
2507         maxlen = min(IPV6_MMTU, maxlen);
2508         /* just for safety */
2509         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2510             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2511                 goto fail;
2512         }
2513
2514         {
2515                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2516                 struct in6_ifaddr *ia;
2517                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2518                                                  IN6_IFF_NOTREADY|
2519                                                  IN6_IFF_ANYCAST)) == NULL)
2520                         goto fail;
2521                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2522         }
2523
2524         /* get ip6 linklocal address for the router. */
2525         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2526                 struct sockaddr_in6 *sin6;
2527                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2528                 router_ll6 = &sin6->sin6_addr;
2529                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2530                         router_ll6 = (struct in6_addr *)NULL;
2531         } else
2532                 router_ll6 = (struct in6_addr *)NULL;
2533
2534         /* ip6 */
2535         ip6 = mtod(m, struct ip6_hdr *);
2536         ip6->ip6_flow = 0;
2537         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2538         ip6->ip6_vfc |= IPV6_VERSION;
2539         /* ip6->ip6_plen will be set later */
2540         ip6->ip6_nxt = IPPROTO_ICMPV6;
2541         ip6->ip6_hlim = 255;
2542         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2543         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2544         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2545
2546         /* ND Redirect */
2547         nd_rd = (struct nd_redirect *)(ip6 + 1);
2548         nd_rd->nd_rd_type = ND_REDIRECT;
2549         nd_rd->nd_rd_code = 0;
2550         nd_rd->nd_rd_reserved = 0;
2551         if (rt->rt_flags & RTF_GATEWAY) {
2552                 /*
2553                  * nd_rd->nd_rd_target must be a link-local address in
2554                  * better router cases.
2555                  */
2556                 if (!router_ll6)
2557                         goto fail;
2558                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2559                     sizeof(nd_rd->nd_rd_target));
2560                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2561                     sizeof(nd_rd->nd_rd_dst));
2562         } else {
2563                 /* make sure redtgt == reddst */
2564                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2565                     sizeof(nd_rd->nd_rd_target));
2566                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2567                     sizeof(nd_rd->nd_rd_dst));
2568         }
2569
2570         p = (u_char *)(nd_rd + 1);
2571
2572         if (!router_ll6)
2573                 goto nolladdropt;
2574
2575         {
2576                 /* target lladdr option */
2577                 struct rtentry *rt_router = NULL;
2578                 int len;
2579                 struct sockaddr_dl *sdl;
2580                 struct nd_opt_hdr *nd_opt;
2581                 char *lladdr;
2582
2583                 rt_router = nd6_lookup(router_ll6, 0, ifp);
2584                 if (!rt_router)
2585                         goto nolladdropt;
2586                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2587                 len = (len + 7) & ~7;   /* round by 8 */
2588                 /* safety check */
2589                 if (len + (p - (u_char *)ip6) > maxlen)
2590                         goto nolladdropt;
2591                 if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2592                     (rt_router->rt_flags & RTF_LLINFO) &&
2593                     (rt_router->rt_gateway->sa_family == AF_LINK) &&
2594                     (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2595                     sdl->sdl_alen) {
2596                         nd_opt = (struct nd_opt_hdr *)p;
2597                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2598                         nd_opt->nd_opt_len = len >> 3;
2599                         lladdr = (char *)(nd_opt + 1);
2600                         bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2601                         p += len;
2602                 }
2603         }
2604 nolladdropt:;
2605
2606         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2607
2608         /* just to be safe */
2609 #ifdef M_DECRYPTED      /*not openbsd*/
2610         if (m0->m_flags & M_DECRYPTED)
2611                 goto noredhdropt;
2612 #endif
2613         if (p - (u_char *)ip6 > maxlen)
2614                 goto noredhdropt;
2615
2616         {
2617                 /* redirected header option */
2618                 int len;
2619                 struct nd_opt_rd_hdr *nd_opt_rh;
2620
2621                 /*
2622                  * compute the maximum size for icmp6 redirect header option.
2623                  * XXX room for auth header?
2624                  */
2625                 len = maxlen - (p - (u_char *)ip6);
2626                 len &= ~7;
2627
2628                 /* This is just for simplicity. */
2629                 if (m0->m_pkthdr.len != m0->m_len) {
2630                         if (m0->m_next) {
2631                                 m_freem(m0->m_next);
2632                                 m0->m_next = NULL;
2633                         }
2634                         m0->m_pkthdr.len = m0->m_len;
2635                 }
2636
2637                 /*
2638                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2639                  * about padding/truncate rule for the original IP packet.
2640                  * From the discussion on IPv6imp in Feb 1999,
2641                  * the consensus was:
2642                  * - "attach as much as possible" is the goal
2643                  * - pad if not aligned (original size can be guessed by
2644                  *   original ip6 header)
2645                  * Following code adds the padding if it is simple enough,
2646                  * and truncates if not.
2647                  */
2648                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2649                         panic("assumption failed in %s:%d", __FILE__,
2650                             __LINE__);
2651
2652                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2653                         /* not enough room, truncate */
2654                         m0->m_pkthdr.len = m0->m_len = len -
2655                             sizeof(*nd_opt_rh);
2656                 } else {
2657                         /* enough room, pad or truncate */
2658                         size_t extra;
2659
2660                         extra = m0->m_pkthdr.len % 8;
2661                         if (extra) {
2662                                 /* pad if easy enough, truncate if not */
2663                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2664                                         /* pad */
2665                                         m0->m_len += (8 - extra);
2666                                         m0->m_pkthdr.len += (8 - extra);
2667                                 } else {
2668                                         /* truncate */
2669                                         m0->m_pkthdr.len -= extra;
2670                                         m0->m_len -= extra;
2671                                 }
2672                         }
2673                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2674                         m0->m_pkthdr.len = m0->m_len = len -
2675                             sizeof(*nd_opt_rh);
2676                 }
2677
2678                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2679                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2680                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2681                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2682                 p += sizeof(*nd_opt_rh);
2683                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2684
2685                 /* connect m0 to m */
2686                 m_tag_delete_chain(m0, NULL);
2687                 m0->m_flags &= ~M_PKTHDR;
2688                 m->m_next = m0;
2689                 m->m_pkthdr.len = m->m_len + m0->m_len;
2690                 m0 = NULL;
2691         }
2692 noredhdropt:;
2693         if (m0) {
2694                 m_freem(m0);
2695                 m0 = NULL;
2696         }
2697
2698         /* XXX: clear embedded link IDs in the inner header */
2699         in6_clearscope(&sip6->ip6_src);
2700         in6_clearscope(&sip6->ip6_dst);
2701         in6_clearscope(&nd_rd->nd_rd_target);
2702         in6_clearscope(&nd_rd->nd_rd_dst);
2703
2704         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2705
2706         nd_rd->nd_rd_cksum = 0;
2707         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2708             sizeof(*ip6), ntohs(ip6->ip6_plen));
2709
2710         /* send the packet to outside... */
2711         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2712         if (outif) {
2713                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2714                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2715         }
2716         icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2717
2718         return;
2719
2720 fail:
2721         if (m)
2722                 m_freem(m);
2723         if (m0)
2724                 m_freem(m0);
2725 }
2726
2727 /*
2728  * ICMPv6 socket option processing.
2729  */
2730 int
2731 icmp6_ctloutput(so, sopt)
2732         struct socket *so;
2733         struct sockopt *sopt;
2734 {
2735         int error = 0;
2736         int optlen;
2737         struct inpcb *inp = sotoinpcb(so);
2738         int level, op, optname;
2739
2740         if (sopt) {
2741                 level = sopt->sopt_level;
2742                 op = sopt->sopt_dir;
2743                 optname = sopt->sopt_name;
2744                 optlen = sopt->sopt_valsize;
2745         } else
2746                 level = op = optname = optlen = 0;
2747
2748         if (level != IPPROTO_ICMPV6) {
2749                 return EINVAL;
2750         }
2751
2752         switch (op) {
2753         case PRCO_SETOPT:
2754                 switch (optname) {
2755                 case ICMP6_FILTER:
2756                     {
2757                         struct icmp6_filter *p;
2758
2759                         if (optlen != sizeof(*p)) {
2760                                 error = EMSGSIZE;
2761                                 break;
2762                         }
2763                         if (inp->in6p_icmp6filt == NULL) {
2764                                 error = EINVAL;
2765                                 break;
2766                         }
2767                         error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
2768                                 optlen);
2769                         break;
2770                     }
2771
2772                 default:
2773                         error = ENOPROTOOPT;
2774                         break;
2775                 }
2776                 break;
2777
2778         case PRCO_GETOPT:
2779                 switch (optname) {
2780                 case ICMP6_FILTER:
2781                     {
2782                         if (inp->in6p_icmp6filt == NULL) {
2783                                 error = EINVAL;
2784                                 break;
2785                         }
2786                         error = sooptcopyout(sopt, inp->in6p_icmp6filt,
2787                                 sizeof(struct icmp6_filter));
2788                         break;
2789                     }
2790
2791                 default:
2792                         error = ENOPROTOOPT;
2793                         break;
2794                 }
2795                 break;
2796         }
2797
2798         return (error);
2799 }
2800
2801 /*
2802  * Perform rate limit check.
2803  * Returns 0 if it is okay to send the icmp6 packet.
2804  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2805  * limitation.
2806  *
2807  * XXX per-destination/type check necessary?
2808  */
2809 static int
2810 icmp6_ratelimit(dst, type, code)
2811         const struct in6_addr *dst;     /* not used at this moment */
2812         const int type;                 /* not used at this moment */
2813         const int code;                 /* not used at this moment */
2814 {
2815         int ret;
2816
2817         ret = 0;        /* okay to send */
2818
2819         /* PPS limit */
2820         if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2821             icmp6errppslim)) {
2822                 /* The packet is subject to rate limit */
2823                 ret++;
2824         }
2825
2826         return ret;
2827 }