sys/netinet6/icmp6.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipsec.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/domain.h>
  72 #include <sys/kernel.h>
  73 #include <sys/lock.h>
  74 #include <sys/malloc.h>
  75 #include <sys/mbuf.h>
  76 #include <sys/protosw.h>
  77 #include <sys/signalvar.h>
  78 #include <sys/socket.h>
  79 #include <sys/socketvar.h>
  80 #include <sys/sx.h>
  81 #include <sys/syslog.h>
  82 #include <sys/systm.h>
  83 #include <sys/time.h>
  84
  85 #include <net/if.h>
  86 #include <net/if_dl.h>
  87 #include <net/if_types.h>
  88 #include <net/route.h>
  89
  90 #include <netinet/in.h>
  91 #include <netinet/in_pcb.h>
  92 #include <netinet/in_var.h>
  93 #include <netinet/ip6.h>
  94 #include <netinet/icmp6.h>
  95 #include <netinet/tcp_var.h>
  96 #include <netinet6/in6_ifattach.h>
  97 #include <netinet6/in6_pcb.h>
  98 #include <netinet6/ip6protosw.h>
  99 #include <netinet6/ip6_var.h>
 100 #include <netinet6/scope6_var.h>
 101 #include <netinet6/mld6_var.h>
 102 #include <netinet6/nd6.h>
 103
 104 #ifdef IPSEC
 105 #include <netipsec/ipsec.h>
 106 #include <netipsec/key.h>
 107 #endif
 108
 109 extern struct domain inet6domain;
 110
 111 struct icmp6stat icmp6stat;
 112
 113 extern struct inpcbinfo ripcbinfo;
 114 extern struct inpcbhead ripcb;
 115 extern int icmp6errppslim;
 116 static int icmp6errpps_count = 0;
 117 static struct timeval icmp6errppslim_last;
 118 extern int icmp6_nodeinfo;
 119
 120 static void icmp6_errcount(struct icmp6errstat *, int, int);
 121 static int icmp6_rip6_input(struct mbuf **, int);
 122 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 123 static const char *icmp6_redirect_diag __P((struct in6_addr *,
 124         struct in6_addr *, struct in6_addr *));
 125 static struct mbuf *ni6_input(struct mbuf *, int);
 126 static struct mbuf *ni6_nametodns(const char *, int, int);
 127 static int ni6_dnsmatch(const char *, int, const char *, int);
 128 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
 129                           struct ifnet **, struct in6_addr *));
 130 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 131                                 struct ifnet *, int));
 132 static int icmp6_notify_error(struct mbuf **, int, int, int);
 133
 134
 135 void
 136 icmp6_init(void)
 137 {
 138
 139         mld6_init();
 140 }
 141
 142 static void
 143 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
 144 {
 145         switch (type) {
 146         case ICMP6_DST_UNREACH:
 147                 switch (code) {
 148                 case ICMP6_DST_UNREACH_NOROUTE:
 149                         stat->icp6errs_dst_unreach_noroute++;
 150                         return;
 151                 case ICMP6_DST_UNREACH_ADMIN:
 152                         stat->icp6errs_dst_unreach_admin++;
 153                         return;
 154                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 155                         stat->icp6errs_dst_unreach_beyondscope++;
 156                         return;
 157                 case ICMP6_DST_UNREACH_ADDR:
 158                         stat->icp6errs_dst_unreach_addr++;
 159                         return;
 160                 case ICMP6_DST_UNREACH_NOPORT:
 161                         stat->icp6errs_dst_unreach_noport++;
 162                         return;
 163                 }
 164                 break;
 165         case ICMP6_PACKET_TOO_BIG:
 166                 stat->icp6errs_packet_too_big++;
 167                 return;
 168         case ICMP6_TIME_EXCEEDED:
 169                 switch (code) {
 170                 case ICMP6_TIME_EXCEED_TRANSIT:
 171                         stat->icp6errs_time_exceed_transit++;
 172                         return;
 173                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 174                         stat->icp6errs_time_exceed_reassembly++;
 175                         return;
 176                 }
 177                 break;
 178         case ICMP6_PARAM_PROB:
 179                 switch (code) {
 180                 case ICMP6_PARAMPROB_HEADER:
 181                         stat->icp6errs_paramprob_header++;
 182                         return;
 183                 case ICMP6_PARAMPROB_NEXTHEADER:
 184                         stat->icp6errs_paramprob_nextheader++;
 185                         return;
 186                 case ICMP6_PARAMPROB_OPTION:
 187                         stat->icp6errs_paramprob_option++;
 188                         return;
 189                 }
 190                 break;
 191         case ND_REDIRECT:
 192                 stat->icp6errs_redirect++;
 193                 return;
 194         }
 195         stat->icp6errs_unknown++;
 196 }
 197
 198 /*
 199  * A wrapper function for icmp6_error() necessary when the erroneous packet
 200  * may not contain enough scope zone information.
 201  */
 202 void
 203 icmp6_error2(struct mbuf *m, int type, int code, int param,
 204     struct ifnet *ifp)
 205 {
 206         struct ip6_hdr *ip6;
 207
 208         if (ifp == NULL)
 209                 return;
 210
 211 #ifndef PULLDOWN_TEST
 212         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 213 #else
 214         if (m->m_len < sizeof(struct ip6_hdr)) {
 215                 m = m_pullup(m, sizeof(struct ip6_hdr));
 216                 if (m == NULL)
 217                         return;
 218         }
 219 #endif
 220
 221         ip6 = mtod(m, struct ip6_hdr *);
 222
 223         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 224                 return;
 225         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 226                 return;
 227
 228         icmp6_error(m, type, code, param);
 229 }
 230
 231 /*
 232  * Generate an error packet of type error in response to bad IP6 packet.
 233  */
 234 void
 235 icmp6_error(struct mbuf *m, int type, int code, int param)
 236 {
 237         struct ip6_hdr *oip6, *nip6;
 238         struct icmp6_hdr *icmp6;
 239         u_int preplen;
 240         int off;
 241         int nxt;
 242
 243         icmp6stat.icp6s_error++;
 244
 245         /* count per-type-code statistics */
 246         icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
 247
 248 #ifdef M_DECRYPTED      /*not openbsd*/
 249         if (m->m_flags & M_DECRYPTED) {
 250                 icmp6stat.icp6s_canterror++;
 251                 goto freeit;
 252         }
 253 #endif
 254
 255 #ifndef PULLDOWN_TEST
 256         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 257 #else
 258         if (m->m_len < sizeof(struct ip6_hdr)) {
 259                 m = m_pullup(m, sizeof(struct ip6_hdr));
 260                 if (m == NULL)
 261                         return;
 262         }
 263 #endif
 264         oip6 = mtod(m, struct ip6_hdr *);
 265
 266         /*
 267          * If the destination address of the erroneous packet is a multicast
 268          * address, or the packet was sent using link-layer multicast,
 269          * we should basically suppress sending an error (RFC 2463, Section
 270          * 2.4).
 271          * We have two exceptions (the item e.2 in that section):
 272          * - the Pakcet Too Big message can be sent for path MTU discovery.
 273          * - the Parameter Problem Message that can be allowed an icmp6 error
 274          *   in the option type field.  This check has been done in
 275          *   ip6_unknown_opt(), so we can just check the type and code.
 276          */
 277         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 278              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 279             (type != ICMP6_PACKET_TOO_BIG &&
 280              (type != ICMP6_PARAM_PROB ||
 281               code != ICMP6_PARAMPROB_OPTION)))
 282                 goto freeit;
 283
 284         /*
 285          * RFC 2463, 2.4 (e.5): source address check.
 286          * XXX: the case of anycast source?
 287          */
 288         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 289             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 290                 goto freeit;
 291
 292         /*
 293          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 294          * don't do it.
 295          */
 296         nxt = -1;
 297         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 298         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 299                 struct icmp6_hdr *icp;
 300
 301 #ifndef PULLDOWN_TEST
 302                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 303                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 304 #else
 305                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 306                         sizeof(*icp));
 307                 if (icp == NULL) {
 308                         icmp6stat.icp6s_tooshort++;
 309                         return;
 310                 }
 311 #endif
 312                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 313                     icp->icmp6_type == ND_REDIRECT) {
 314                         /*
 315                          * ICMPv6 error
 316                          * Special case: for redirect (which is
 317                          * informational) we must not send icmp6 error.
 318                          */
 319                         icmp6stat.icp6s_canterror++;
 320                         goto freeit;
 321                 } else {
 322                         /* ICMPv6 informational - send the error */
 323                 }
 324         } else {
 325                 /* non-ICMPv6 - send the error */
 326         }
 327
 328         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 329
 330         /* Finally, do rate limitation check. */
 331         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 332                 icmp6stat.icp6s_toofreq++;
 333                 goto freeit;
 334         }
 335
 336         /*
 337          * OK, ICMP6 can be generated.
 338          */
 339
 340         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 341                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 342
 343         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 344         M_PREPEND(m, preplen, M_DONTWAIT);
 345         if (m && m->m_len < preplen)
 346                 m = m_pullup(m, preplen);
 347         if (m == NULL) {
 348                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 349                 return;
 350         }
 351
 352         nip6 = mtod(m, struct ip6_hdr *);
 353         nip6->ip6_src  = oip6->ip6_src;
 354         nip6->ip6_dst  = oip6->ip6_dst;
 355
 356         in6_clearscope(&oip6->ip6_src);
 357         in6_clearscope(&oip6->ip6_dst);
 358
 359         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 360         icmp6->icmp6_type = type;
 361         icmp6->icmp6_code = code;
 362         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 363
 364         /*
 365          * icmp6_reflect() is designed to be in the input path.
 366          * icmp6_error() can be called from both input and output path,
 367          * and if we are in output path rcvif could contain bogus value.
 368          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 369          * information in ip header (nip6).
 370          */
 371         m->m_pkthdr.rcvif = NULL;
 372
 373         icmp6stat.icp6s_outhist[type]++;
 374         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 375
 376         return;
 377
 378   freeit:
 379         /*
 380          * If we can't tell whether or not we can generate ICMP6, free it.
 381          */
 382         m_freem(m);
 383 }
 384
 385 /*
 386  * Process a received ICMP6 message.
 387  */
 388 int
 389 icmp6_input(struct mbuf **mp, int *offp, int proto)
 390 {
 391         struct mbuf *m = *mp, *n;
 392         struct ip6_hdr *ip6, *nip6;
 393         struct icmp6_hdr *icmp6, *nicmp6;
 394         int off = *offp;
 395         int icmp6len = m->m_pkthdr.len - *offp;
 396         int code, sum, noff;
 397         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 398
 399 #ifndef PULLDOWN_TEST
 400         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 401         /* m might change if M_LOOP.  So, call mtod after this */
 402 #endif
 403
 404         /*
 405          * Locate icmp6 structure in mbuf, and check
 406          * that not corrupted and of at least minimum length
 407          */
 408
 409         ip6 = mtod(m, struct ip6_hdr *);
 410         if (icmp6len < sizeof(struct icmp6_hdr)) {
 411                 icmp6stat.icp6s_tooshort++;
 412                 goto freeit;
 413         }
 414
 415         /*
 416          * calculate the checksum
 417          */
 418 #ifndef PULLDOWN_TEST
 419         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 420 #else
 421         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 422         if (icmp6 == NULL) {
 423                 icmp6stat.icp6s_tooshort++;
 424                 return IPPROTO_DONE;
 425         }
 426 #endif
 427         code = icmp6->icmp6_code;
 428
 429         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 430                 nd6log((LOG_ERR,
 431                     "ICMP6 checksum error(%d|%x) %s\n",
 432                     icmp6->icmp6_type, sum,
 433                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 434                 icmp6stat.icp6s_checksum++;
 435                 goto freeit;
 436         }
 437
 438         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 439                 /*
 440                  * Deliver very specific ICMP6 type only.
 441                  * This is important to deliver TOOBIG.  Otherwise PMTUD
 442                  * will not work.
 443                  */
 444                 switch (icmp6->icmp6_type) {
 445                 case ICMP6_DST_UNREACH:
 446                 case ICMP6_PACKET_TOO_BIG:
 447                 case ICMP6_TIME_EXCEEDED:
 448                         break;
 449                 default:
 450                         goto freeit;
 451                 }
 452         }
 453
 454         icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
 455         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
 456         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 457                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
 458
 459         switch (icmp6->icmp6_type) {
 460         case ICMP6_DST_UNREACH:
 461                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
 462                 switch (code) {
 463                 case ICMP6_DST_UNREACH_NOROUTE:
 464                         code = PRC_UNREACH_NET;
 465                         break;
 466                 case ICMP6_DST_UNREACH_ADMIN:
 467                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
 468                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 469                         break;
 470                 case ICMP6_DST_UNREACH_ADDR:
 471                         code = PRC_HOSTDEAD;
 472                         break;
 473                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 474                         /* I mean "source address was incorrect." */
 475                         code = PRC_PARAMPROB;
 476                         break;
 477                 case ICMP6_DST_UNREACH_NOPORT:
 478                         code = PRC_UNREACH_PORT;
 479                         break;
 480                 default:
 481                         goto badcode;
 482                 }
 483                 goto deliver;
 484                 break;
 485
 486         case ICMP6_PACKET_TOO_BIG:
 487                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
 488
 489                 /* validation is made in icmp6_mtudisc_update */
 490
 491                 code = PRC_MSGSIZE;
 492
 493                 /*
 494                  * Updating the path MTU will be done after examining
 495                  * intermediate extension headers.
 496                  */
 497                 goto deliver;
 498                 break;
 499
 500         case ICMP6_TIME_EXCEEDED:
 501                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
 502                 switch (code) {
 503                 case ICMP6_TIME_EXCEED_TRANSIT:
 504                         code = PRC_TIMXCEED_INTRANS;
 505                         break;
 506                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 507                         code = PRC_TIMXCEED_REASS;
 508                         break;
 509                 default:
 510                         goto badcode;
 511                 }
 512                 goto deliver;
 513                 break;
 514
 515         case ICMP6_PARAM_PROB:
 516                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
 517                 switch (code) {
 518                 case ICMP6_PARAMPROB_NEXTHEADER:
 519                         code = PRC_UNREACH_PROTOCOL;
 520                         break;
 521                 case ICMP6_PARAMPROB_HEADER:
 522                 case ICMP6_PARAMPROB_OPTION:
 523                         code = PRC_PARAMPROB;
 524                         break;
 525                 default:
 526                         goto badcode;
 527                 }
 528                 goto deliver;
 529                 break;
 530
 531         case ICMP6_ECHO_REQUEST:
 532                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
 533                 if (code != 0)
 534                         goto badcode;
 535                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 536                         /* Give up remote */
 537                         break;
 538                 }
 539                 if ((n->m_flags & M_EXT) != 0
 540                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 541                         struct mbuf *n0 = n;
 542                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 543                         int n0len;
 544
 545                         MGETHDR(n, M_DONTWAIT, n0->m_type);
 546                         n0len = n0->m_pkthdr.len;       /* save for use below */
 547                         if (n)
 548                                 M_MOVE_PKTHDR(n, n0);
 549                         if (n && maxlen >= MHLEN) {
 550                                 MCLGET(n, M_DONTWAIT);
 551                                 if ((n->m_flags & M_EXT) == 0) {
 552                                         m_free(n);
 553                                         n = NULL;
 554                                 }
 555                         }
 556                         if (n == NULL) {
 557                                 /* Give up remote */
 558                                 m_freem(n0);
 559                                 break;
 560                         }
 561                         /*
 562                          * Copy IPv6 and ICMPv6 only.
 563                          */
 564                         nip6 = mtod(n, struct ip6_hdr *);
 565                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 566                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 567                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 568                         noff = sizeof(struct ip6_hdr);
 569                         /* new mbuf contains only ipv6+icmpv6 headers */
 570                         n->m_len = noff + sizeof(struct icmp6_hdr);
 571                         /*
 572                          * Adjust mbuf.  ip6_plen will be adjusted in
 573                          * ip6_output().
 574                          */
 575                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 576                         /* recalculate complete packet size */
 577                         n->m_pkthdr.len = n0len + (noff - off);
 578                         n->m_next = n0;
 579                 } else {
 580                         nip6 = mtod(n, struct ip6_hdr *);
 581                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 582                             sizeof(*nicmp6));
 583                         noff = off;
 584                 }
 585                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 586                 nicmp6->icmp6_code = 0;
 587                 if (n) {
 588                         icmp6stat.icp6s_reflect++;
 589                         icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
 590                         icmp6_reflect(n, noff);
 591                 }
 592                 break;
 593
 594         case ICMP6_ECHO_REPLY:
 595                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
 596                 if (code != 0)
 597                         goto badcode;
 598                 break;
 599
 600         case MLD_LISTENER_QUERY:
 601         case MLD_LISTENER_REPORT:
 602                 if (icmp6len < sizeof(struct mld_hdr))
 603                         goto badlen;
 604                 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
 605                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
 606                 else
 607                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
 608                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 609                         /* give up local */
 610                         mld6_input(m, off);
 611                         m = NULL;
 612                         goto freeit;
 613                 }
 614                 mld6_input(n, off);
 615                 /* m stays. */
 616                 break;
 617
 618         case MLD_LISTENER_DONE:
 619                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
 620                 if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
 621                         goto badlen;
 622                 break;          /* nothing to be done in kernel */
 623
 624         case MLD_MTRACE_RESP:
 625         case MLD_MTRACE:
 626                 /* XXX: these two are experimental.  not officially defined. */
 627                 /* XXX: per-interface statistics? */
 628                 break;          /* just pass it to applications */
 629
 630         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 631             {
 632                 enum { WRU, FQDN } mode;
 633
 634                 if (!icmp6_nodeinfo)
 635                         break;
 636
 637                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 638                         mode = WRU;
 639                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 640                         mode = FQDN;
 641                 else
 642                         goto badlen;
 643
 644 #define hostnamelen     strlen(hostname)
 645                 if (mode == FQDN) {
 646 #ifndef PULLDOWN_TEST
 647                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 648                             IPPROTO_DONE);
 649 #endif
 650                         n = m_copy(m, 0, M_COPYALL);
 651                         if (n)
 652                                 n = ni6_input(n, off);
 653                         /* XXX meaningless if n == NULL */
 654                         noff = sizeof(struct ip6_hdr);
 655                 } else {
 656                         u_char *p;
 657                         int maxlen, maxhlen;
 658
 659                         /*
 660                          * XXX: this combination of flags is pointless,
 661                          * but should we keep this for compatibility?
 662                          */
 663                         if ((icmp6_nodeinfo & 5) != 5)
 664                                 break;
 665
 666                         if (code != 0)
 667                                 goto badcode;
 668                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 669                         if (maxlen >= MCLBYTES) {
 670                                 /* Give up remote */
 671                                 break;
 672                         }
 673                         MGETHDR(n, M_DONTWAIT, m->m_type);
 674                         if (n && maxlen > MHLEN) {
 675                                 MCLGET(n, M_DONTWAIT);
 676                                 if ((n->m_flags & M_EXT) == 0) {
 677                                         m_free(n);
 678                                         n = NULL;
 679                                 }
 680                         }
 681                         if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
 682                                 /*
 683                                  * Previous code did a blind M_COPY_PKTHDR
 684                                  * and said "just for rcvif".  If true, then
 685                                  * we could tolerate the dup failing (due to
 686                                  * the deep copy of the tag chain).  For now
 687                                  * be conservative and just fail.
 688                                  */
 689                                 m_free(n);
 690                                 n = NULL;
 691                         }
 692                         if (n == NULL) {
 693                                 /* Give up remote */
 694                                 break;
 695                         }
 696                         n->m_pkthdr.rcvif = NULL;
 697                         n->m_len = 0;
 698                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 699                         mtx_lock(&hostname_mtx);
 700                         if (maxhlen > hostnamelen)
 701                                 maxhlen = hostnamelen;
 702                         /*
 703                          * Copy IPv6 and ICMPv6 only.
 704                          */
 705                         nip6 = mtod(n, struct ip6_hdr *);
 706                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 707                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 708                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 709                         p = (u_char *)(nicmp6 + 1);
 710                         bzero(p, 4);
 711                         bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
 712                         mtx_unlock(&hostname_mtx);
 713                         noff = sizeof(struct ip6_hdr);
 714                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 715                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 716                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 717                         nicmp6->icmp6_code = 0;
 718                 }
 719 #undef hostnamelen
 720                 if (n) {
 721                         icmp6stat.icp6s_reflect++;
 722                         icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
 723                         icmp6_reflect(n, noff);
 724                 }
 725                 break;
 726             }
 727
 728         case ICMP6_WRUREPLY:
 729                 if (code != 0)
 730                         goto badcode;
 731                 break;
 732
 733         case ND_ROUTER_SOLICIT:
 734                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
 735                 if (code != 0)
 736                         goto badcode;
 737                 if (icmp6len < sizeof(struct nd_router_solicit))
 738                         goto badlen;
 739                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 740                         /* give up local */
 741                         nd6_rs_input(m, off, icmp6len);
 742                         m = NULL;
 743                         goto freeit;
 744                 }
 745                 nd6_rs_input(n, off, icmp6len);
 746                 /* m stays. */
 747                 break;
 748
 749         case ND_ROUTER_ADVERT:
 750                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
 751                 if (code != 0)
 752                         goto badcode;
 753                 if (icmp6len < sizeof(struct nd_router_advert))
 754                         goto badlen;
 755                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 756                         /* give up local */
 757                         nd6_ra_input(m, off, icmp6len);
 758                         m = NULL;
 759                         goto freeit;
 760                 }
 761                 nd6_ra_input(n, off, icmp6len);
 762                 /* m stays. */
 763                 break;
 764
 765         case ND_NEIGHBOR_SOLICIT:
 766                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
 767                 if (code != 0)
 768                         goto badcode;
 769                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 770                         goto badlen;
 771                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 772                         /* give up local */
 773                         nd6_ns_input(m, off, icmp6len);
 774                         m = NULL;
 775                         goto freeit;
 776                 }
 777                 nd6_ns_input(n, off, icmp6len);
 778                 /* m stays. */
 779                 break;
 780
 781         case ND_NEIGHBOR_ADVERT:
 782                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
 783                 if (code != 0)
 784                         goto badcode;
 785                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 786                         goto badlen;
 787                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 788                         /* give up local */
 789                         nd6_na_input(m, off, icmp6len);
 790                         m = NULL;
 791                         goto freeit;
 792                 }
 793                 nd6_na_input(n, off, icmp6len);
 794                 /* m stays. */
 795                 break;
 796
 797         case ND_REDIRECT:
 798                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
 799                 if (code != 0)
 800                         goto badcode;
 801                 if (icmp6len < sizeof(struct nd_redirect))
 802                         goto badlen;
 803                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 804                         /* give up local */
 805                         icmp6_redirect_input(m, off);
 806                         m = NULL;
 807                         goto freeit;
 808                 }
 809                 icmp6_redirect_input(n, off);
 810                 /* m stays. */
 811                 break;
 812
 813         case ICMP6_ROUTER_RENUMBERING:
 814                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 815                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 816                         goto badcode;
 817                 if (icmp6len < sizeof(struct icmp6_router_renum))
 818                         goto badlen;
 819                 break;
 820
 821         default:
 822                 nd6log((LOG_DEBUG,
 823                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 824                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 825                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 826                     m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
 827                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 828                         /* ICMPv6 error: MUST deliver it by spec... */
 829                         code = PRC_NCMDS;
 830                         /* deliver */
 831                 } else {
 832                         /* ICMPv6 informational: MUST not deliver */
 833                         break;
 834                 }
 835         deliver:
 836                 if (icmp6_notify_error(&m, off, icmp6len, code)) {
 837                         /* In this case, m should've been freed. */
 838                         return (IPPROTO_DONE);
 839                 }
 840                 break;
 841
 842         badcode:
 843                 icmp6stat.icp6s_badcode++;
 844                 break;
 845
 846         badlen:
 847                 icmp6stat.icp6s_badlen++;
 848                 break;
 849         }
 850
 851         /* deliver the packet to appropriate sockets */
 852         icmp6_rip6_input(&m, *offp);
 853
 854         return IPPROTO_DONE;
 855
 856  freeit:
 857         m_freem(m);
 858         return IPPROTO_DONE;
 859 }
 860
 861 static int
 862 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 863 {
 864         struct mbuf *m = *mp;
 865         struct icmp6_hdr *icmp6;
 866         struct ip6_hdr *eip6;
 867         u_int32_t notifymtu;
 868         struct sockaddr_in6 icmp6src, icmp6dst;
 869
 870         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 871                 icmp6stat.icp6s_tooshort++;
 872                 goto freeit;
 873         }
 874 #ifndef PULLDOWN_TEST
 875         IP6_EXTHDR_CHECK(m, off,
 876             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 877         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 878 #else
 879         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 880             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 881         if (icmp6 == NULL) {
 882                 icmp6stat.icp6s_tooshort++;
 883                 return (-1);
 884         }
 885 #endif
 886         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 887
 888         /* Detect the upper level protocol */
 889         {
 890                 void (*ctlfunc)(int, struct sockaddr *, void *);
 891                 u_int8_t nxt = eip6->ip6_nxt;
 892                 int eoff = off + sizeof(struct icmp6_hdr) +
 893                     sizeof(struct ip6_hdr);
 894                 struct ip6ctlparam ip6cp;
 895                 struct in6_addr *finaldst = NULL;
 896                 int icmp6type = icmp6->icmp6_type;
 897                 struct ip6_frag *fh;
 898                 struct ip6_rthdr *rth;
 899                 struct ip6_rthdr0 *rth0;
 900                 int rthlen;
 901
 902                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 903                         struct ip6_ext *eh;
 904
 905                         switch (nxt) {
 906                         case IPPROTO_HOPOPTS:
 907                         case IPPROTO_DSTOPTS:
 908                         case IPPROTO_AH:
 909 #ifndef PULLDOWN_TEST
 910                                 IP6_EXTHDR_CHECK(m, 0,
 911                                     eoff + sizeof(struct ip6_ext), -1);
 912                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 913 #else
 914                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 915                                     eoff, sizeof(*eh));
 916                                 if (eh == NULL) {
 917                                         icmp6stat.icp6s_tooshort++;
 918                                         return (-1);
 919                                 }
 920 #endif
 921
 922                                 if (nxt == IPPROTO_AH)
 923                                         eoff += (eh->ip6e_len + 2) << 2;
 924                                 else
 925                                         eoff += (eh->ip6e_len + 1) << 3;
 926                                 nxt = eh->ip6e_nxt;
 927                                 break;
 928                         case IPPROTO_ROUTING:
 929                                 /*
 930                                  * When the erroneous packet contains a
 931                                  * routing header, we should examine the
 932                                  * header to determine the final destination.
 933                                  * Otherwise, we can't properly update
 934                                  * information that depends on the final
 935                                  * destination (e.g. path MTU).
 936                                  */
 937 #ifndef PULLDOWN_TEST
 938                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 939                                 rth = (struct ip6_rthdr *)
 940                                     (mtod(m, caddr_t) + eoff);
 941 #else
 942                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 943                                     eoff, sizeof(*rth));
 944                                 if (rth == NULL) {
 945                                         icmp6stat.icp6s_tooshort++;
 946                                         return (-1);
 947                                 }
 948 #endif
 949                                 rthlen = (rth->ip6r_len + 1) << 3;
 950                                 /*
 951                                  * XXX: currently there is no
 952                                  * officially defined type other
 953                                  * than type-0.
 954                                  * Note that if the segment left field
 955                                  * is 0, all intermediate hops must
 956                                  * have been passed.
 957                                  */
 958                                 if (rth->ip6r_segleft &&
 959                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 960                                         int hops;
 961
 962 #ifndef PULLDOWN_TEST
 963                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 964                                         rth0 = (struct ip6_rthdr0 *)
 965                                             (mtod(m, caddr_t) + eoff);
 966 #else
 967                                         IP6_EXTHDR_GET(rth0,
 968                                             struct ip6_rthdr0 *, m,
 969                                             eoff, rthlen);
 970                                         if (rth0 == NULL) {
 971                                                 icmp6stat.icp6s_tooshort++;
 972                                                 return (-1);
 973                                         }
 974 #endif
 975                                         /* just ignore a bogus header */
 976                                         if ((rth0->ip6r0_len % 2) == 0 &&
 977                                             (hops = rth0->ip6r0_len/2))
 978                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 979                                 }
 980                                 eoff += rthlen;
 981                                 nxt = rth->ip6r_nxt;
 982                                 break;
 983                         case IPPROTO_FRAGMENT:
 984 #ifndef PULLDOWN_TEST
 985                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 986                                     sizeof(struct ip6_frag), -1);
 987                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
 988                                     eoff);
 989 #else
 990                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
 991                                     eoff, sizeof(*fh));
 992                                 if (fh == NULL) {
 993                                         icmp6stat.icp6s_tooshort++;
 994                                         return (-1);
 995                                 }
 996 #endif
 997                                 /*
 998                                  * Data after a fragment header is meaningless
 999                                  * unless it is the first fragment, but
1000                                  * we'll go to the notify label for path MTU
1001                                  * discovery.
1002                                  */
1003                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1004                                         goto notify;
1005
1006                                 eoff += sizeof(struct ip6_frag);
1007                                 nxt = fh->ip6f_nxt;
1008                                 break;
1009                         default:
1010                                 /*
1011                                  * This case includes ESP and the No Next
1012                                  * Header.  In such cases going to the notify
1013                                  * label does not have any meaning
1014                                  * (i.e. ctlfunc will be NULL), but we go
1015                                  * anyway since we might have to update
1016                                  * path MTU information.
1017                                  */
1018                                 goto notify;
1019                         }
1020                 }
1021           notify:
1022 #ifndef PULLDOWN_TEST
1023                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1024 #else
1025                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1026                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1027                 if (icmp6 == NULL) {
1028                         icmp6stat.icp6s_tooshort++;
1029                         return (-1);
1030                 }
1031 #endif
1032
1033                 /*
1034                  * retrieve parameters from the inner IPv6 header, and convert
1035                  * them into sockaddr structures.
1036                  * XXX: there is no guarantee that the source or destination
1037                  * addresses of the inner packet are in the same scope as
1038                  * the addresses of the icmp packet.  But there is no other
1039                  * way to determine the zone.
1040                  */
1041                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1042
1043                 bzero(&icmp6dst, sizeof(icmp6dst));
1044                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1045                 icmp6dst.sin6_family = AF_INET6;
1046                 if (finaldst == NULL)
1047                         icmp6dst.sin6_addr = eip6->ip6_dst;
1048                 else
1049                         icmp6dst.sin6_addr = *finaldst;
1050                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1051                         goto freeit;
1052                 bzero(&icmp6src, sizeof(icmp6src));
1053                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1054                 icmp6src.sin6_family = AF_INET6;
1055                 icmp6src.sin6_addr = eip6->ip6_src;
1056                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1057                         goto freeit;
1058                 icmp6src.sin6_flowinfo =
1059                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1060
1061                 if (finaldst == NULL)
1062                         finaldst = &eip6->ip6_dst;
1063                 ip6cp.ip6c_m = m;
1064                 ip6cp.ip6c_icmp6 = icmp6;
1065                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1066                 ip6cp.ip6c_off = eoff;
1067                 ip6cp.ip6c_finaldst = finaldst;
1068                 ip6cp.ip6c_src = &icmp6src;
1069                 ip6cp.ip6c_nxt = nxt;
1070
1071                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1072                         notifymtu = ntohl(icmp6->icmp6_mtu);
1073                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1074                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1075                 }
1076
1077                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1078                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1079                 if (ctlfunc) {
1080                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1081                             &ip6cp);
1082                 }
1083         }
1084         *mp = m;
1085         return (0);
1086
1087   freeit:
1088         m_freem(m);
1089         return (-1);
1090 }
1091
1092 void
1093 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1094 {
1095         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1096         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1097         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1098         u_int mtu = ntohl(icmp6->icmp6_mtu);
1099         struct in_conninfo inc;
1100
1101 #if 0
1102         /*
1103          * RFC2460 section 5, last paragraph.
1104          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1105          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1106          * due to packet translator in the middle.
1107          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1108          * special handling.
1109          */
1110         if (mtu < IPV6_MMTU)
1111                 return;
1112 #endif
1113
1114         /*
1115          * we reject ICMPv6 too big with abnormally small value.
1116          * XXX what is the good definition of "abnormally small"?
1117          */
1118         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1119                 return;
1120
1121         if (!validated)
1122                 return;
1123
1124         bzero(&inc, sizeof(inc));
1125         inc.inc_flags = 1; /* IPv6 */
1126         inc.inc6_faddr = *dst;
1127         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1128                 return;
1129
1130         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1131                 tcp_hc_updatemtu(&inc, mtu);
1132                 icmp6stat.icp6s_pmtuchg++;
1133         }
1134 }
1135
1136 /*
1137  * Process a Node Information Query packet, based on
1138  * draft-ietf-ipngwg-icmp-name-lookups-07.
1139  *
1140  * Spec incompatibilities:
1141  * - IPv6 Subject address handling
1142  * - IPv4 Subject address handling support missing
1143  * - Proxy reply (answer even if it's not for me)
1144  * - joins NI group address at in6_ifattach() time only, does not cope
1145  *   with hostname changes by sethostname(3)
1146  */
1147 #define hostnamelen     strlen(hostname)
1148 static struct mbuf *
1149 ni6_input(struct mbuf *m, int off)
1150 {
1151         struct icmp6_nodeinfo *ni6, *nni6;
1152         struct mbuf *n = NULL;
1153         u_int16_t qtype;
1154         int subjlen;
1155         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1156         struct ni_reply_fqdn *fqdn;
1157         int addrs;              /* for NI_QTYPE_NODEADDR */
1158         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1159         struct in6_addr in6_subj; /* subject address */
1160         struct ip6_hdr *ip6;
1161         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1162         char *subj = NULL;
1163         struct in6_ifaddr *ia6 = NULL;
1164
1165         ip6 = mtod(m, struct ip6_hdr *);
1166 #ifndef PULLDOWN_TEST
1167         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1168 #else
1169         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1170         if (ni6 == NULL) {
1171                 /* m is already reclaimed */
1172                 return (NULL);
1173         }
1174 #endif
1175
1176         /*
1177          * Validate IPv6 source address.
1178          * The default configuration MUST be to refuse answering queries from
1179          * global-scope addresses according to RFC4602.
1180          * Notes:
1181          *  - it's not very clear what "refuse" means; this implementation
1182          *    simply drops it.
1183          *  - it's not very easy to identify global-scope (unicast) addresses
1184          *    since there are many prefixes for them.  It should be safer
1185          *    and in practice sufficient to check "all" but loopback and
1186          *    link-local (note that site-local unicast was deprecated and
1187          *    ULA is defined as global scope-wise)
1188          */
1189         if ((icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1190             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1191             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1192                 goto bad;
1193
1194         /*
1195          * Validate IPv6 destination address.
1196          *
1197          * The Responder must discard the Query without further processing
1198          * unless it is one of the Responder's unicast or anycast addresses, or
1199          * a link-local scope multicast address which the Responder has joined.
1200          * [RFC4602, Section 5.]
1201          */
1202         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1203                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1204                         goto bad;
1205                 /* else it's a link-local multicast, fine */
1206         } else {                /* unicast or anycast */
1207                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1208                         goto bad; /* XXX impossible */
1209
1210                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1211                     !(icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1212                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1213                                 "a temporary address in %s:%d",
1214                                __FILE__, __LINE__));
1215                         goto bad;
1216                 }
1217         }
1218
1219         /* validate query Subject field. */
1220         qtype = ntohs(ni6->ni_qtype);
1221         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1222         switch (qtype) {
1223         case NI_QTYPE_NOOP:
1224         case NI_QTYPE_SUPTYPES:
1225                 /* 07 draft */
1226                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1227                         break;
1228                 /* FALLTHROUGH */
1229         case NI_QTYPE_FQDN:
1230         case NI_QTYPE_NODEADDR:
1231         case NI_QTYPE_IPV4ADDR:
1232                 switch (ni6->ni_code) {
1233                 case ICMP6_NI_SUBJ_IPV6:
1234 #if ICMP6_NI_SUBJ_IPV6 != 0
1235                 case 0:
1236 #endif
1237                         /*
1238                          * backward compatibility - try to accept 03 draft
1239                          * format, where no Subject is present.
1240                          */
1241                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1242                             subjlen == 0) {
1243                                 oldfqdn++;
1244                                 break;
1245                         }
1246 #if ICMP6_NI_SUBJ_IPV6 != 0
1247                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1248                                 goto bad;
1249 #endif
1250
1251                         if (subjlen != sizeof(struct in6_addr))
1252                                 goto bad;
1253
1254                         /*
1255                          * Validate Subject address.
1256                          *
1257                          * Not sure what exactly "address belongs to the node"
1258                          * means in the spec, is it just unicast, or what?
1259                          *
1260                          * At this moment we consider Subject address as
1261                          * "belong to the node" if the Subject address equals
1262                          * to the IPv6 destination address; validation for
1263                          * IPv6 destination address should have done enough
1264                          * check for us.
1265                          *
1266                          * We do not do proxy at this moment.
1267                          */
1268                         /* m_pulldown instead of copy? */
1269                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1270                             subjlen, (caddr_t)&in6_subj);
1271                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1272                                 goto bad;
1273
1274                         subj = (char *)&in6_subj;
1275                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1276                                 break;
1277
1278                         /*
1279                          * XXX if we are to allow other cases, we should really
1280                          * be careful about scope here.
1281                          * basically, we should disallow queries toward IPv6
1282                          * destination X with subject Y,
1283                          * if scope(X) > scope(Y).
1284                          * if we allow scope(X) > scope(Y), it will result in
1285                          * information leakage across scope boundary.
1286                          */
1287                         goto bad;
1288
1289                 case ICMP6_NI_SUBJ_FQDN:
1290                         /*
1291                          * Validate Subject name with gethostname(3).
1292                          *
1293                          * The behavior may need some debate, since:
1294                          * - we are not sure if the node has FQDN as
1295                          *   hostname (returned by gethostname(3)).
1296                          * - the code does wildcard match for truncated names.
1297                          *   however, we are not sure if we want to perform
1298                          *   wildcard match, if gethostname(3) side has
1299                          *   truncated hostname.
1300                          */
1301                         mtx_lock(&hostname_mtx);
1302                         n = ni6_nametodns(hostname, hostnamelen, 0);
1303                         mtx_unlock(&hostname_mtx);
1304                         if (!n || n->m_next || n->m_len == 0)
1305                                 goto bad;
1306                         IP6_EXTHDR_GET(subj, char *, m,
1307                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1308                         if (subj == NULL)
1309                                 goto bad;
1310                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1311                             n->m_len)) {
1312                                 goto bad;
1313                         }
1314                         m_freem(n);
1315                         n = NULL;
1316                         break;
1317
1318                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1319                 default:
1320                         goto bad;
1321                 }
1322                 break;
1323         }
1324
1325         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1326         switch (qtype) {
1327         case NI_QTYPE_FQDN:
1328                 if ((icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1329                         goto bad;
1330                 break;
1331         case NI_QTYPE_NODEADDR:
1332         case NI_QTYPE_IPV4ADDR:
1333                 if ((icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1334                         goto bad;
1335                 break;
1336         }
1337
1338         /* guess reply length */
1339         switch (qtype) {
1340         case NI_QTYPE_NOOP:
1341                 break;          /* no reply data */
1342         case NI_QTYPE_SUPTYPES:
1343                 replylen += sizeof(u_int32_t);
1344                 break;
1345         case NI_QTYPE_FQDN:
1346                 /* XXX will append an mbuf */
1347                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1348                 break;
1349         case NI_QTYPE_NODEADDR:
1350                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1351                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1352                     sizeof(u_int32_t))) > MCLBYTES)
1353                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1354                 break;
1355         case NI_QTYPE_IPV4ADDR:
1356                 /* unsupported - should respond with unknown Qtype? */
1357                 break;
1358         default:
1359                 /*
1360                  * XXX: We must return a reply with the ICMP6 code
1361                  * `unknown Qtype' in this case.  However we regard the case
1362                  * as an FQDN query for backward compatibility.
1363                  * Older versions set a random value to this field,
1364                  * so it rarely varies in the defined qtypes.
1365                  * But the mechanism is not reliable...
1366                  * maybe we should obsolete older versions.
1367                  */
1368                 qtype = NI_QTYPE_FQDN;
1369                 /* XXX will append an mbuf */
1370                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1371                 oldfqdn++;
1372                 break;
1373         }
1374
1375         /* allocate an mbuf to reply. */
1376         MGETHDR(n, M_DONTWAIT, m->m_type);
1377         if (n == NULL) {
1378                 m_freem(m);
1379                 return (NULL);
1380         }
1381         M_MOVE_PKTHDR(n, m); /* just for recvif */
1382         if (replylen > MHLEN) {
1383                 if (replylen > MCLBYTES) {
1384                         /*
1385                          * XXX: should we try to allocate more? But MCLBYTES
1386                          * is probably much larger than IPV6_MMTU...
1387                          */
1388                         goto bad;
1389                 }
1390                 MCLGET(n, M_DONTWAIT);
1391                 if ((n->m_flags & M_EXT) == 0) {
1392                         goto bad;
1393                 }
1394         }
1395         n->m_pkthdr.len = n->m_len = replylen;
1396
1397         /* copy mbuf header and IPv6 + Node Information base headers */
1398         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1399         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1400         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1401
1402         /* qtype dependent procedure */
1403         switch (qtype) {
1404         case NI_QTYPE_NOOP:
1405                 nni6->ni_code = ICMP6_NI_SUCCESS;
1406                 nni6->ni_flags = 0;
1407                 break;
1408         case NI_QTYPE_SUPTYPES:
1409         {
1410                 u_int32_t v;
1411                 nni6->ni_code = ICMP6_NI_SUCCESS;
1412                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1413                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1414                 v = (u_int32_t)htonl(0x0000000f);
1415                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1416                 break;
1417         }
1418         case NI_QTYPE_FQDN:
1419                 nni6->ni_code = ICMP6_NI_SUCCESS;
1420                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1421                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1422                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1423                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1424                 /*
1425                  * XXX do we really have FQDN in variable "hostname"?
1426                  */
1427                 mtx_lock(&hostname_mtx);
1428                 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1429                 mtx_unlock(&hostname_mtx);
1430                 if (n->m_next == NULL)
1431                         goto bad;
1432                 /* XXX we assume that n->m_next is not a chain */
1433                 if (n->m_next->m_next != NULL)
1434                         goto bad;
1435                 n->m_pkthdr.len += n->m_next->m_len;
1436                 break;
1437         case NI_QTYPE_NODEADDR:
1438         {
1439                 int lenlim, copied;
1440
1441                 nni6->ni_code = ICMP6_NI_SUCCESS;
1442                 n->m_pkthdr.len = n->m_len =
1443                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1444                 lenlim = M_TRAILINGSPACE(n);
1445                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1446                 /* XXX: reset mbuf length */
1447                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1448                     sizeof(struct icmp6_nodeinfo) + copied;
1449                 break;
1450         }
1451         default:
1452                 break;          /* XXX impossible! */
1453         }
1454
1455         nni6->ni_type = ICMP6_NI_REPLY;
1456         m_freem(m);
1457         return (n);
1458
1459   bad:
1460         m_freem(m);
1461         if (n)
1462                 m_freem(n);
1463         return (NULL);
1464 }
1465 #undef hostnamelen
1466
1467 /*
1468  * make a mbuf with DNS-encoded string.  no compression support.
1469  *
1470  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1471  * treated as truncated name (two \0 at the end).  this is a wild guess.
1472  *
1473  * old - return pascal string if non-zero
1474  */
1475 static struct mbuf *
1476 ni6_nametodns(const char *name, int namelen, int old)
1477 {
1478         struct mbuf *m;
1479         char *cp, *ep;
1480         const char *p, *q;
1481         int i, len, nterm;
1482
1483         if (old)
1484                 len = namelen + 1;
1485         else
1486                 len = MCLBYTES;
1487
1488         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1489         MGET(m, M_DONTWAIT, MT_DATA);
1490         if (m && len > MLEN) {
1491                 MCLGET(m, M_DONTWAIT);
1492                 if ((m->m_flags & M_EXT) == 0)
1493                         goto fail;
1494         }
1495         if (!m)
1496                 goto fail;
1497         m->m_next = NULL;
1498
1499         if (old) {
1500                 m->m_len = len;
1501                 *mtod(m, char *) = namelen;
1502                 bcopy(name, mtod(m, char *) + 1, namelen);
1503                 return m;
1504         } else {
1505                 m->m_len = 0;
1506                 cp = mtod(m, char *);
1507                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1508
1509                 /* if not certain about my name, return empty buffer */
1510                 if (namelen == 0)
1511                         return m;
1512
1513                 /*
1514                  * guess if it looks like shortened hostname, or FQDN.
1515                  * shortened hostname needs two trailing "\0".
1516                  */
1517                 i = 0;
1518                 for (p = name; p < name + namelen; p++) {
1519                         if (*p && *p == '.')
1520                                 i++;
1521                 }
1522                 if (i < 2)
1523                         nterm = 2;
1524                 else
1525                         nterm = 1;
1526
1527                 p = name;
1528                 while (cp < ep && p < name + namelen) {
1529                         i = 0;
1530                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1531                                 i++;
1532                         /* result does not fit into mbuf */
1533                         if (cp + i + 1 >= ep)
1534                                 goto fail;
1535                         /*
1536                          * DNS label length restriction, RFC1035 page 8.
1537                          * "i == 0" case is included here to avoid returning
1538                          * 0-length label on "foo..bar".
1539                          */
1540                         if (i <= 0 || i >= 64)
1541                                 goto fail;
1542                         *cp++ = i;
1543                         bcopy(p, cp, i);
1544                         cp += i;
1545                         p = q;
1546                         if (p < name + namelen && *p == '.')
1547                                 p++;
1548                 }
1549                 /* termination */
1550                 if (cp + nterm >= ep)
1551                         goto fail;
1552                 while (nterm-- > 0)
1553                         *cp++ = '\0';
1554                 m->m_len = cp - mtod(m, char *);
1555                 return m;
1556         }
1557
1558         panic("should not reach here");
1559         /* NOTREACHED */
1560
1561  fail:
1562         if (m)
1563                 m_freem(m);
1564         return NULL;
1565 }
1566
1567 /*
1568  * check if two DNS-encoded string matches.  takes care of truncated
1569  * form (with \0\0 at the end).  no compression support.
1570  * XXX upper/lowercase match (see RFC2065)
1571  */
1572 static int
1573 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1574 {
1575         const char *a0, *b0;
1576         int l;
1577
1578         /* simplest case - need validation? */
1579         if (alen == blen && bcmp(a, b, alen) == 0)
1580                 return 1;
1581
1582         a0 = a;
1583         b0 = b;
1584
1585         /* termination is mandatory */
1586         if (alen < 2 || blen < 2)
1587                 return 0;
1588         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1589                 return 0;
1590         alen--;
1591         blen--;
1592
1593         while (a - a0 < alen && b - b0 < blen) {
1594                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1595                         return 0;
1596
1597                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1598                         return 0;
1599                 /* we don't support compression yet */
1600                 if (a[0] >= 64 || b[0] >= 64)
1601                         return 0;
1602
1603                 /* truncated case */
1604                 if (a[0] == 0 && a - a0 == alen - 1)
1605                         return 1;
1606                 if (b[0] == 0 && b - b0 == blen - 1)
1607                         return 1;
1608                 if (a[0] == 0 || b[0] == 0)
1609                         return 0;
1610
1611                 if (a[0] != b[0])
1612                         return 0;
1613                 l = a[0];
1614                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1615                         return 0;
1616                 if (bcmp(a + 1, b + 1, l) != 0)
1617                         return 0;
1618
1619                 a += 1 + l;
1620                 b += 1 + l;
1621         }
1622
1623         if (a - a0 == alen && b - b0 == blen)
1624                 return 1;
1625         else
1626                 return 0;
1627 }
1628
1629 /*
1630  * calculate the number of addresses to be returned in the node info reply.
1631  */
1632 static int
1633 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1634     struct in6_addr *subj)
1635 {
1636         struct ifnet *ifp;
1637         struct in6_ifaddr *ifa6;
1638         struct ifaddr *ifa;
1639         int addrs = 0, addrsofif, iffound = 0;
1640         int niflags = ni6->ni_flags;
1641
1642         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1643                 switch (ni6->ni_code) {
1644                 case ICMP6_NI_SUBJ_IPV6:
1645                         if (subj == NULL) /* must be impossible... */
1646                                 return (0);
1647                         break;
1648                 default:
1649                         /*
1650                          * XXX: we only support IPv6 subject address for
1651                          * this Qtype.
1652                          */
1653                         return (0);
1654                 }
1655         }
1656
1657         IFNET_RLOCK();
1658         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1659                 addrsofif = 0;
1660                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1661                         if (ifa->ifa_addr->sa_family != AF_INET6)
1662                                 continue;
1663                         ifa6 = (struct in6_ifaddr *)ifa;
1664
1665                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1666                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1667                                 iffound = 1;
1668
1669                         /*
1670                          * IPv4-mapped addresses can only be returned by a
1671                          * Node Information proxy, since they represent
1672                          * addresses of IPv4-only nodes, which perforce do
1673                          * not implement this protocol.
1674                          * [icmp-name-lookups-07, Section 5.4]
1675                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1676                          * this function at this moment.
1677                          */
1678
1679                         /* What do we have to do about ::1? */
1680                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1681                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1682                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1683                                         continue;
1684                                 break;
1685                         case IPV6_ADDR_SCOPE_SITELOCAL:
1686                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1687                                         continue;
1688                                 break;
1689                         case IPV6_ADDR_SCOPE_GLOBAL:
1690                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1691                                         continue;
1692                                 break;
1693                         default:
1694                                 continue;
1695                         }
1696
1697                         /*
1698                          * check if anycast is okay.
1699                          * XXX: just experimental.  not in the spec.
1700                          */
1701                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1702                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1703                                 continue; /* we need only unicast addresses */
1704                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1705                             (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1706                                 continue;
1707                         }
1708                         addrsofif++; /* count the address */
1709                 }
1710                 if (iffound) {
1711                         *ifpp = ifp;
1712                         IFNET_RUNLOCK();
1713                         return (addrsofif);
1714                 }
1715
1716                 addrs += addrsofif;
1717         }
1718         IFNET_RUNLOCK();
1719
1720         return (addrs);
1721 }
1722
1723 static int
1724 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1725     struct ifnet *ifp0, int resid)
1726 {
1727         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1728         struct in6_ifaddr *ifa6;
1729         struct ifaddr *ifa;
1730         struct ifnet *ifp_dep = NULL;
1731         int copied = 0, allow_deprecated = 0;
1732         u_char *cp = (u_char *)(nni6 + 1);
1733         int niflags = ni6->ni_flags;
1734         u_int32_t ltime;
1735
1736         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1737                 return (0);     /* needless to copy */
1738
1739         IFNET_RLOCK();
1740   again:
1741
1742         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1743                 for (ifa = ifp->if_addrlist.tqh_first; ifa;
1744                      ifa = ifa->ifa_list.tqe_next) {
1745                         if (ifa->ifa_addr->sa_family != AF_INET6)
1746                                 continue;
1747                         ifa6 = (struct in6_ifaddr *)ifa;
1748
1749                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1750                             allow_deprecated == 0) {
1751                                 /*
1752                                  * prefererred address should be put before
1753                                  * deprecated addresses.
1754                                  */
1755
1756                                 /* record the interface for later search */
1757                                 if (ifp_dep == NULL)
1758                                         ifp_dep = ifp;
1759
1760                                 continue;
1761                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1762                             allow_deprecated != 0)
1763                                 continue; /* we now collect deprecated addrs */
1764
1765                         /* What do we have to do about ::1? */
1766                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1767                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1768                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1769                                         continue;
1770                                 break;
1771                         case IPV6_ADDR_SCOPE_SITELOCAL:
1772                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1773                                         continue;
1774                                 break;
1775                         case IPV6_ADDR_SCOPE_GLOBAL:
1776                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1777                                         continue;
1778                                 break;
1779                         default:
1780                                 continue;
1781                         }
1782
1783                         /*
1784                          * check if anycast is okay.
1785                          * XXX: just experimental.  not in the spec.
1786                          */
1787                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1788                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1789                                 continue;
1790                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1791                             (icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1792                                 continue;
1793                         }
1794
1795                         /* now we can copy the address */
1796                         if (resid < sizeof(struct in6_addr) +
1797                             sizeof(u_int32_t)) {
1798                                 /*
1799                                  * We give up much more copy.
1800                                  * Set the truncate flag and return.
1801                                  */
1802                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1803                                 IFNET_RUNLOCK();
1804                                 return (copied);
1805                         }
1806
1807                         /*
1808                          * Set the TTL of the address.
1809                          * The TTL value should be one of the following
1810                          * according to the specification:
1811                          *
1812                          * 1. The remaining lifetime of a DHCP lease on the
1813                          *    address, or
1814                          * 2. The remaining Valid Lifetime of a prefix from
1815                          *    which the address was derived through Stateless
1816                          *    Autoconfiguration.
1817                          *
1818                          * Note that we currently do not support stateful
1819                          * address configuration by DHCPv6, so the former
1820                          * case can't happen.
1821                          */
1822                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1823                                 ltime = ND6_INFINITE_LIFETIME;
1824                         else {
1825                                 if (ifa6->ia6_lifetime.ia6t_expire >
1826                                     time_second)
1827                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1828                                 else
1829                                         ltime = 0;
1830                         }
1831
1832                         bcopy(&ltime, cp, sizeof(u_int32_t));
1833                         cp += sizeof(u_int32_t);
1834
1835                         /* copy the address itself */
1836                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1837                             sizeof(struct in6_addr));
1838                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1839                         cp += sizeof(struct in6_addr);
1840
1841                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1842                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1843                 }
1844                 if (ifp0)       /* we need search only on the specified IF */
1845                         break;
1846         }
1847
1848         if (allow_deprecated == 0 && ifp_dep != NULL) {
1849                 ifp = ifp_dep;
1850                 allow_deprecated = 1;
1851
1852                 goto again;
1853         }
1854
1855         IFNET_RUNLOCK();
1856
1857         return (copied);
1858 }
1859
1860 /*
1861  * XXX almost dup'ed code with rip6_input.
1862  */
1863 static int
1864 icmp6_rip6_input(struct mbuf **mp, int off)
1865 {
1866         struct mbuf *m = *mp;
1867         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1868         struct in6pcb *in6p;
1869         struct in6pcb *last = NULL;
1870         struct sockaddr_in6 fromsa;
1871         struct icmp6_hdr *icmp6;
1872         struct mbuf *opts = NULL;
1873
1874 #ifndef PULLDOWN_TEST
1875         /* this is assumed to be safe. */
1876         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1877 #else
1878         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1879         if (icmp6 == NULL) {
1880                 /* m is already reclaimed */
1881                 return (IPPROTO_DONE);
1882         }
1883 #endif
1884
1885         /*
1886          * XXX: the address may have embedded scope zone ID, which should be
1887          * hidden from applications.
1888          */
1889         bzero(&fromsa, sizeof(fromsa));
1890         fromsa.sin6_family = AF_INET6;
1891         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1892         fromsa.sin6_addr = ip6->ip6_src;
1893         if (sa6_recoverscope(&fromsa)) {
1894                 m_freem(m);
1895                 return (IPPROTO_DONE);
1896         }
1897
1898         INP_INFO_RLOCK(&ripcbinfo);
1899         LIST_FOREACH(in6p, &ripcb, inp_list) {
1900                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1901                         continue;
1902                 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1903                         continue;
1904                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1905                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1906                         continue;
1907                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1908                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1909                         continue;
1910                 INP_RLOCK(in6p);
1911                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1912                     in6p->in6p_icmp6filt)) {
1913                         INP_RUNLOCK(in6p);
1914                         continue;
1915                 }
1916                 if (last) {
1917                         struct  mbuf *n = NULL;
1918
1919                         /*
1920                          * Recent network drivers tend to allocate a single
1921                          * mbuf cluster, rather than to make a couple of
1922                          * mbufs without clusters.  Also, since the IPv6 code
1923                          * path tries to avoid m_pullup(), it is highly
1924                          * probable that we still have an mbuf cluster here
1925                          * even though the necessary length can be stored in an
1926                          * mbuf's internal buffer.
1927                          * Meanwhile, the default size of the receive socket
1928                          * buffer for raw sockets is not so large.  This means
1929                          * the possibility of packet loss is relatively higher
1930                          * than before.  To avoid this scenario, we copy the
1931                          * received data to a separate mbuf that does not use
1932                          * a cluster, if possible.
1933                          * XXX: it is better to copy the data after stripping
1934                          * intermediate headers.
1935                          */
1936                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1937                             m->m_len <= MHLEN) {
1938                                 MGET(n, M_DONTWAIT, m->m_type);
1939                                 if (n != NULL) {
1940                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1941                                                 bcopy(m->m_data, n->m_data,
1942                                                       m->m_len);
1943                                                 n->m_len = m->m_len;
1944                                         } else {
1945                                                 m_free(n);
1946                                                 n = NULL;
1947                                         }
1948                                 }
1949                         }
1950                         if (n != NULL ||
1951                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1952                                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1953                                         ip6_savecontrol(last, n, &opts);
1954                                 /* strip intermediate headers */
1955                                 m_adj(n, off);
1956                                 SOCKBUF_LOCK(&last->in6p_socket->so_rcv);
1957                                 if (sbappendaddr_locked(
1958                                     &last->in6p_socket->so_rcv,
1959                                     (struct sockaddr *)&fromsa, n, opts)
1960                                     == 0) {
1961                                         /* should notify about lost packet */
1962                                         m_freem(n);
1963                                         if (opts) {
1964                                                 m_freem(opts);
1965                                         }
1966                                         SOCKBUF_UNLOCK(
1967                                             &last->in6p_socket->so_rcv);
1968                                 } else
1969                                         sorwakeup_locked(last->in6p_socket);
1970                                 opts = NULL;
1971                         }
1972                         INP_RUNLOCK(last);
1973                 }
1974                 last = in6p;
1975         }
1976         INP_INFO_RUNLOCK(&ripcbinfo);
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                                 if (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                                 } else {
1997                                         m_freem(n);
1998                                         n = NULL;
1999                                 }
2000                         }
2001                 }
2002                 SOCKBUF_LOCK(&last->in6p_socket->so_rcv);
2003                 if (sbappendaddr_locked(&last->in6p_socket->so_rcv,
2004                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2005                         m_freem(m);
2006                         if (opts)
2007                                 m_freem(opts);
2008                         SOCKBUF_UNLOCK(&last->in6p_socket->so_rcv);
2009                 } else
2010                         sorwakeup_locked(last->in6p_socket);
2011                 INP_RUNLOCK(last);
2012         } else {
2013                 m_freem(m);
2014                 ip6stat.ip6s_delivered--;
2015         }
2016         return IPPROTO_DONE;
2017 }
2018
2019 /*
2020  * Reflect the ip6 packet back to the source.
2021  * OFF points to the icmp6 header, counted from the top of the mbuf.
2022  */
2023 void
2024 icmp6_reflect(struct mbuf *m, size_t off)
2025 {
2026         struct ip6_hdr *ip6;
2027         struct icmp6_hdr *icmp6;
2028         struct in6_ifaddr *ia;
2029         int plen;
2030         int type, code;
2031         struct ifnet *outif = NULL;
2032         struct in6_addr origdst, *src = NULL;
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         origdst = 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          * If the incoming packet was addressed directly to us (i.e. unicast),
2088          * use dst as the src for the reply.
2089          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2090          * (for example) when we encounter an error while forwarding procedure
2091          * destined to a duplicated address of ours.
2092          * Note that ip6_getdstifaddr() may fail if we are in an error handling
2093          * procedure of an outgoing packet of our own, in which case we need
2094          * to search in the ifaddr list.
2095          */
2096         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2097                 if ((ia = ip6_getdstifaddr(m))) {
2098                         if (!(ia->ia6_flags &
2099                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2100                                 src = &ia->ia_addr.sin6_addr;
2101                 } else {
2102                         struct sockaddr_in6 d;
2103
2104                         bzero(&d, sizeof(d));
2105                         d.sin6_family = AF_INET6;
2106                         d.sin6_len = sizeof(d);
2107                         d.sin6_addr = origdst;
2108                         ia = (struct in6_ifaddr *)
2109                             ifa_ifwithaddr((struct sockaddr *)&d);
2110                         if (ia &&
2111                             !(ia->ia6_flags &
2112                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2113                                 src = &ia->ia_addr.sin6_addr;
2114                         }
2115                 }
2116         }
2117
2118         if (src == NULL) {
2119                 int e;
2120                 struct sockaddr_in6 sin6;
2121                 struct route_in6 ro;
2122
2123                 /*
2124                  * This case matches to multicasts, our anycast, or unicasts
2125                  * that we do not own.  Select a source address based on the
2126                  * source address of the erroneous packet.
2127                  */
2128                 bzero(&sin6, sizeof(sin6));
2129                 sin6.sin6_family = AF_INET6;
2130                 sin6.sin6_len = sizeof(sin6);
2131                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2132
2133                 bzero(&ro, sizeof(ro));
2134                 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e);
2135                 if (ro.ro_rt)
2136                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2137                 if (src == NULL) {
2138                         char ip6buf[INET6_ADDRSTRLEN];
2139                         nd6log((LOG_DEBUG,
2140                             "icmp6_reflect: source can't be determined: "
2141                             "dst=%s, error=%d\n",
2142                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2143                         goto bad;
2144                 }
2145         }
2146
2147         ip6->ip6_src = *src;
2148         ip6->ip6_flow = 0;
2149         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2150         ip6->ip6_vfc |= IPV6_VERSION;
2151         ip6->ip6_nxt = IPPROTO_ICMPV6;
2152         if (outif)
2153                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2154         else if (m->m_pkthdr.rcvif) {
2155                 /* XXX: This may not be the outgoing interface */
2156                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2157         } else
2158                 ip6->ip6_hlim = ip6_defhlim;
2159
2160         icmp6->icmp6_cksum = 0;
2161         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2162             sizeof(struct ip6_hdr), plen);
2163
2164         /*
2165          * XXX option handling
2166          */
2167
2168         m->m_flags &= ~(M_BCAST|M_MCAST);
2169
2170         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2171         if (outif)
2172                 icmp6_ifoutstat_inc(outif, type, code);
2173
2174         return;
2175
2176  bad:
2177         m_freem(m);
2178         return;
2179 }
2180
2181 void
2182 icmp6_fasttimo(void)
2183 {
2184
2185         return;
2186 }
2187
2188 static const char *
2189 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2190     struct in6_addr *tgt6)
2191 {
2192         static char buf[1024];
2193         char ip6bufs[INET6_ADDRSTRLEN];
2194         char ip6bufd[INET6_ADDRSTRLEN];
2195         char ip6buft[INET6_ADDRSTRLEN];
2196         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2197             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2198             ip6_sprintf(ip6buft, tgt6));
2199         return buf;
2200 }
2201
2202 void
2203 icmp6_redirect_input(struct mbuf *m, int off)
2204 {
2205         struct ifnet *ifp;
2206         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2207         struct nd_redirect *nd_rd;
2208         int icmp6len = ntohs(ip6->ip6_plen);
2209         char *lladdr = NULL;
2210         int lladdrlen = 0;
2211         u_char *redirhdr = NULL;
2212         int redirhdrlen = 0;
2213         struct rtentry *rt = NULL;
2214         int is_router;
2215         int is_onlink;
2216         struct in6_addr src6 = ip6->ip6_src;
2217         struct in6_addr redtgt6;
2218         struct in6_addr reddst6;
2219         union nd_opts ndopts;
2220         char ip6buf[INET6_ADDRSTRLEN];
2221
2222         if (!m)
2223                 return;
2224
2225         ifp = m->m_pkthdr.rcvif;
2226
2227         if (!ifp)
2228                 return;
2229
2230         /* XXX if we are router, we don't update route by icmp6 redirect */
2231         if (ip6_forwarding)
2232                 goto freeit;
2233         if (!icmp6_rediraccept)
2234                 goto freeit;
2235
2236 #ifndef PULLDOWN_TEST
2237         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2238         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2239 #else
2240         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2241         if (nd_rd == NULL) {
2242                 icmp6stat.icp6s_tooshort++;
2243                 return;
2244         }
2245 #endif
2246         redtgt6 = nd_rd->nd_rd_target;
2247         reddst6 = nd_rd->nd_rd_dst;
2248
2249         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2250             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2251                 goto freeit;
2252         }
2253
2254         /* validation */
2255         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2256                 nd6log((LOG_ERR,
2257                     "ICMP6 redirect sent from %s rejected; "
2258                     "must be from linklocal\n",
2259                     ip6_sprintf(ip6buf, &src6)));
2260                 goto bad;
2261         }
2262         if (ip6->ip6_hlim != 255) {
2263                 nd6log((LOG_ERR,
2264                     "ICMP6 redirect sent from %s rejected; "
2265                     "hlim=%d (must be 255)\n",
2266                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2267                 goto bad;
2268         }
2269     {
2270         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2271         struct sockaddr_in6 sin6;
2272         struct in6_addr *gw6;
2273
2274         bzero(&sin6, sizeof(sin6));
2275         sin6.sin6_family = AF_INET6;
2276         sin6.sin6_len = sizeof(struct sockaddr_in6);
2277         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2278         rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2279         if (rt) {
2280                 if (rt->rt_gateway == NULL ||
2281                     rt->rt_gateway->sa_family != AF_INET6) {
2282                         nd6log((LOG_ERR,
2283                             "ICMP6 redirect rejected; no route "
2284                             "with inet6 gateway found for redirect dst: %s\n",
2285                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2286                         RTFREE_LOCKED(rt);
2287                         goto bad;
2288                 }
2289
2290                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2291                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2292                         nd6log((LOG_ERR,
2293                             "ICMP6 redirect rejected; "
2294                             "not equal to gw-for-src=%s (must be same): "
2295                             "%s\n",
2296                             ip6_sprintf(ip6buf, gw6),
2297                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2298                         RTFREE_LOCKED(rt);
2299                         goto bad;
2300                 }
2301         } else {
2302                 nd6log((LOG_ERR,
2303                     "ICMP6 redirect rejected; "
2304                     "no route found for redirect dst: %s\n",
2305                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2306                 goto bad;
2307         }
2308         RTFREE_LOCKED(rt);
2309         rt = NULL;
2310     }
2311         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2312                 nd6log((LOG_ERR,
2313                     "ICMP6 redirect rejected; "
2314                     "redirect dst must be unicast: %s\n",
2315                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2316                 goto bad;
2317         }
2318
2319         is_router = is_onlink = 0;
2320         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2321                 is_router = 1;  /* router case */
2322         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2323                 is_onlink = 1;  /* on-link destination case */
2324         if (!is_router && !is_onlink) {
2325                 nd6log((LOG_ERR,
2326                     "ICMP6 redirect rejected; "
2327                     "neither router case nor onlink case: %s\n",
2328                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2329                 goto bad;
2330         }
2331         /* validation passed */
2332
2333         icmp6len -= sizeof(*nd_rd);
2334         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2335         if (nd6_options(&ndopts) < 0) {
2336                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2337                     "invalid ND option, rejected: %s\n",
2338                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2339                 /* nd6_options have incremented stats */
2340                 goto freeit;
2341         }
2342
2343         if (ndopts.nd_opts_tgt_lladdr) {
2344                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2345                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2346         }
2347
2348         if (ndopts.nd_opts_rh) {
2349                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2350                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2351         }
2352
2353         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2354                 nd6log((LOG_INFO,
2355                     "icmp6_redirect_input: lladdrlen mismatch for %s "
2356                     "(if %d, icmp6 packet %d): %s\n",
2357                     ip6_sprintf(ip6buf, &redtgt6),
2358                     ifp->if_addrlen, lladdrlen - 2,
2359                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2360                 goto bad;
2361         }
2362
2363         /* RFC 2461 8.3 */
2364         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2365             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2366
2367         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2368                 /* perform rtredirect */
2369                 struct sockaddr_in6 sdst;
2370                 struct sockaddr_in6 sgw;
2371                 struct sockaddr_in6 ssrc;
2372
2373                 bzero(&sdst, sizeof(sdst));
2374                 bzero(&sgw, sizeof(sgw));
2375                 bzero(&ssrc, sizeof(ssrc));
2376                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2377                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2378                         sizeof(struct sockaddr_in6);
2379                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2380                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2381                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2382                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2383                     (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2384                     (struct sockaddr *)&ssrc);
2385         }
2386         /* finally update cached route in each socket via pfctlinput */
2387     {
2388         struct sockaddr_in6 sdst;
2389
2390         bzero(&sdst, sizeof(sdst));
2391         sdst.sin6_family = AF_INET6;
2392         sdst.sin6_len = sizeof(struct sockaddr_in6);
2393         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2394         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2395 #ifdef IPSEC
2396         key_sa_routechange((struct sockaddr *)&sdst);
2397 #endif /* IPSEC */
2398     }
2399
2400  freeit:
2401         m_freem(m);
2402         return;
2403
2404  bad:
2405         icmp6stat.icp6s_badredirect++;
2406         m_freem(m);
2407 }
2408
2409 void
2410 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2411 {
2412         struct ifnet *ifp;      /* my outgoing interface */
2413         struct in6_addr *ifp_ll6;
2414         struct in6_addr *router_ll6;
2415         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2416         struct mbuf *m = NULL;  /* newly allocated one */
2417         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2418         struct nd_redirect *nd_rd;
2419         size_t maxlen;
2420         u_char *p;
2421         struct ifnet *outif = NULL;
2422         struct sockaddr_in6 src_sa;
2423
2424         icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2425
2426         /* if we are not router, we don't send icmp6 redirect */
2427         if (!ip6_forwarding)
2428                 goto fail;
2429
2430         /* sanity check */
2431         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2432                 goto fail;
2433
2434         /*
2435          * Address check:
2436          *  the source address must identify a neighbor, and
2437          *  the destination address must not be a multicast address
2438          *  [RFC 2461, sec 8.2]
2439          */
2440         sip6 = mtod(m0, struct ip6_hdr *);
2441         bzero(&src_sa, sizeof(src_sa));
2442         src_sa.sin6_family = AF_INET6;
2443         src_sa.sin6_len = sizeof(src_sa);
2444         src_sa.sin6_addr = sip6->ip6_src;
2445         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2446                 goto fail;
2447         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2448                 goto fail;      /* what should we do here? */
2449
2450         /* rate limit */
2451         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2452                 goto fail;
2453
2454         /*
2455          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2456          * we almost always ask for an mbuf cluster for simplicity.
2457          * (MHLEN < IPV6_MMTU is almost always true)
2458          */
2459 #if IPV6_MMTU >= MCLBYTES
2460 # error assumption failed about IPV6_MMTU and MCLBYTES
2461 #endif
2462         MGETHDR(m, M_DONTWAIT, MT_HEADER);
2463         if (m && IPV6_MMTU >= MHLEN)
2464                 MCLGET(m, M_DONTWAIT);
2465         if (!m)
2466                 goto fail;
2467         m->m_pkthdr.rcvif = NULL;
2468         m->m_len = 0;
2469         maxlen = M_TRAILINGSPACE(m);
2470         maxlen = min(IPV6_MMTU, maxlen);
2471         /* just for safety */
2472         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2473             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2474                 goto fail;
2475         }
2476
2477         {
2478                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2479                 struct in6_ifaddr *ia;
2480                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2481                                                  IN6_IFF_NOTREADY|
2482                                                  IN6_IFF_ANYCAST)) == NULL)
2483                         goto fail;
2484                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2485         }
2486
2487         /* get ip6 linklocal address for the router. */
2488         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2489                 struct sockaddr_in6 *sin6;
2490                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2491                 router_ll6 = &sin6->sin6_addr;
2492                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2493                         router_ll6 = (struct in6_addr *)NULL;
2494         } else
2495                 router_ll6 = (struct in6_addr *)NULL;
2496
2497         /* ip6 */
2498         ip6 = mtod(m, struct ip6_hdr *);
2499         ip6->ip6_flow = 0;
2500         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2501         ip6->ip6_vfc |= IPV6_VERSION;
2502         /* ip6->ip6_plen will be set later */
2503         ip6->ip6_nxt = IPPROTO_ICMPV6;
2504         ip6->ip6_hlim = 255;
2505         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2506         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2507         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2508
2509         /* ND Redirect */
2510         nd_rd = (struct nd_redirect *)(ip6 + 1);
2511         nd_rd->nd_rd_type = ND_REDIRECT;
2512         nd_rd->nd_rd_code = 0;
2513         nd_rd->nd_rd_reserved = 0;
2514         if (rt->rt_flags & RTF_GATEWAY) {
2515                 /*
2516                  * nd_rd->nd_rd_target must be a link-local address in
2517                  * better router cases.
2518                  */
2519                 if (!router_ll6)
2520                         goto fail;
2521                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2522                     sizeof(nd_rd->nd_rd_target));
2523                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2524                     sizeof(nd_rd->nd_rd_dst));
2525         } else {
2526                 /* make sure redtgt == reddst */
2527                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2528                     sizeof(nd_rd->nd_rd_target));
2529                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2530                     sizeof(nd_rd->nd_rd_dst));
2531         }
2532
2533         p = (u_char *)(nd_rd + 1);
2534
2535         if (!router_ll6)
2536                 goto nolladdropt;
2537
2538         {
2539                 /* target lladdr option */
2540                 struct rtentry *rt_router = NULL;
2541                 int len;
2542                 struct sockaddr_dl *sdl;
2543                 struct nd_opt_hdr *nd_opt;
2544                 char *lladdr;
2545
2546                 rt_router = nd6_lookup(router_ll6, 0, ifp);
2547                 if (!rt_router)
2548                         goto nolladdropt;
2549                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2550                 len = (len + 7) & ~7;   /* round by 8 */
2551                 /* safety check */
2552                 if (len + (p - (u_char *)ip6) > maxlen)
2553                         goto nolladdropt;
2554                 if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2555                     (rt_router->rt_flags & RTF_LLINFO) &&
2556                     (rt_router->rt_gateway->sa_family == AF_LINK) &&
2557                     (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2558                     sdl->sdl_alen) {
2559                         nd_opt = (struct nd_opt_hdr *)p;
2560                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2561                         nd_opt->nd_opt_len = len >> 3;
2562                         lladdr = (char *)(nd_opt + 1);
2563                         bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2564                         p += len;
2565                 }
2566         }
2567 nolladdropt:;
2568
2569         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2570
2571         /* just to be safe */
2572 #ifdef M_DECRYPTED      /*not openbsd*/
2573         if (m0->m_flags & M_DECRYPTED)
2574                 goto noredhdropt;
2575 #endif
2576         if (p - (u_char *)ip6 > maxlen)
2577                 goto noredhdropt;
2578
2579         {
2580                 /* redirected header option */
2581                 int len;
2582                 struct nd_opt_rd_hdr *nd_opt_rh;
2583
2584                 /*
2585                  * compute the maximum size for icmp6 redirect header option.
2586                  * XXX room for auth header?
2587                  */
2588                 len = maxlen - (p - (u_char *)ip6);
2589                 len &= ~7;
2590
2591                 /* This is just for simplicity. */
2592                 if (m0->m_pkthdr.len != m0->m_len) {
2593                         if (m0->m_next) {
2594                                 m_freem(m0->m_next);
2595                                 m0->m_next = NULL;
2596                         }
2597                         m0->m_pkthdr.len = m0->m_len;
2598                 }
2599
2600                 /*
2601                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2602                  * about padding/truncate rule for the original IP packet.
2603                  * From the discussion on IPv6imp in Feb 1999,
2604                  * the consensus was:
2605                  * - "attach as much as possible" is the goal
2606                  * - pad if not aligned (original size can be guessed by
2607                  *   original ip6 header)
2608                  * Following code adds the padding if it is simple enough,
2609                  * and truncates if not.
2610                  */
2611                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2612                         panic("assumption failed in %s:%d", __FILE__,
2613                             __LINE__);
2614
2615                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2616                         /* not enough room, truncate */
2617                         m0->m_pkthdr.len = m0->m_len = len -
2618                             sizeof(*nd_opt_rh);
2619                 } else {
2620                         /* enough room, pad or truncate */
2621                         size_t extra;
2622
2623                         extra = m0->m_pkthdr.len % 8;
2624                         if (extra) {
2625                                 /* pad if easy enough, truncate if not */
2626                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2627                                         /* pad */
2628                                         m0->m_len += (8 - extra);
2629                                         m0->m_pkthdr.len += (8 - extra);
2630                                 } else {
2631                                         /* truncate */
2632                                         m0->m_pkthdr.len -= extra;
2633                                         m0->m_len -= extra;
2634                                 }
2635                         }
2636                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2637                         m0->m_pkthdr.len = m0->m_len = len -
2638                             sizeof(*nd_opt_rh);
2639                 }
2640
2641                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2642                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2643                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2644                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2645                 p += sizeof(*nd_opt_rh);
2646                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2647
2648                 /* connect m0 to m */
2649                 m_tag_delete_chain(m0, NULL);
2650                 m0->m_flags &= ~M_PKTHDR;
2651                 m->m_next = m0;
2652                 m->m_pkthdr.len = m->m_len + m0->m_len;
2653                 m0 = NULL;
2654         }
2655 noredhdropt:;
2656         if (m0) {
2657                 m_freem(m0);
2658                 m0 = NULL;
2659         }
2660
2661         /* XXX: clear embedded link IDs in the inner header */
2662         in6_clearscope(&sip6->ip6_src);
2663         in6_clearscope(&sip6->ip6_dst);
2664         in6_clearscope(&nd_rd->nd_rd_target);
2665         in6_clearscope(&nd_rd->nd_rd_dst);
2666
2667         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2668
2669         nd_rd->nd_rd_cksum = 0;
2670         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2671             sizeof(*ip6), ntohs(ip6->ip6_plen));
2672
2673         /* send the packet to outside... */
2674         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2675         if (outif) {
2676                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2677                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2678         }
2679         icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2680
2681         return;
2682
2683 fail:
2684         if (m)
2685                 m_freem(m);
2686         if (m0)
2687                 m_freem(m0);
2688 }
2689
2690 /*
2691  * ICMPv6 socket option processing.
2692  */
2693 int
2694 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2695 {
2696         int error = 0;
2697         int optlen;
2698         struct inpcb *inp = sotoinpcb(so);
2699         int level, op, optname;
2700
2701         if (sopt) {
2702                 level = sopt->sopt_level;
2703                 op = sopt->sopt_dir;
2704                 optname = sopt->sopt_name;
2705                 optlen = sopt->sopt_valsize;
2706         } else
2707                 level = op = optname = optlen = 0;
2708
2709         if (level != IPPROTO_ICMPV6) {
2710                 return EINVAL;
2711         }
2712
2713         switch (op) {
2714         case PRCO_SETOPT:
2715                 switch (optname) {
2716                 case ICMP6_FILTER:
2717                     {
2718                         struct icmp6_filter ic6f;
2719
2720                         if (optlen != sizeof(ic6f)) {
2721                                 error = EMSGSIZE;
2722                                 break;
2723                         }
2724                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2725                         if (error == 0) {
2726                                 INP_WLOCK(inp);
2727                                 *inp->in6p_icmp6filt = ic6f;
2728                                 INP_WUNLOCK(inp);
2729                         }
2730                         break;
2731                     }
2732
2733                 default:
2734                         error = ENOPROTOOPT;
2735                         break;
2736                 }
2737                 break;
2738
2739         case PRCO_GETOPT:
2740                 switch (optname) {
2741                 case ICMP6_FILTER:
2742                     {
2743                         struct icmp6_filter ic6f;
2744
2745                         INP_RLOCK(inp);
2746                         ic6f = *inp->in6p_icmp6filt;
2747                         INP_RUNLOCK(inp);
2748                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2749                         break;
2750                     }
2751
2752                 default:
2753                         error = ENOPROTOOPT;
2754                         break;
2755                 }
2756                 break;
2757         }
2758
2759         return (error);
2760 }
2761
2762 /*
2763  * Perform rate limit check.
2764  * Returns 0 if it is okay to send the icmp6 packet.
2765  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2766  * limitation.
2767  *
2768  * XXX per-destination/type check necessary?
2769  *
2770  * dst - not used at this moment
2771  * type - not used at this moment
2772  * code - not used at this moment
2773  */
2774 static int
2775 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2776     const int code)
2777 {
2778         int ret;
2779
2780         ret = 0;        /* okay to send */
2781
2782         /* PPS limit */
2783         if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2784             icmp6errppslim)) {
2785                 /* The packet is subject to rate limit */
2786                 ret++;
2787         }
2788
2789         return ret;
2790 }