sys/netinet6/icmp6.c

   1 /*      $FreeBSD$       */
   2 /*      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */
   3
   4 /*-
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*-
  34  * Copyright (c) 1982, 1986, 1988, 1993
  35  *      The Regents of the University of California.  All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  62  */
  63
  64 #include "opt_inet.h"
  65 #include "opt_inet6.h"
  66 #include "opt_ipsec.h"
  67
  68 #include <sys/param.h>
  69 #include <sys/domain.h>
  70 #include <sys/kernel.h>
  71 #include <sys/lock.h>
  72 #include <sys/malloc.h>
  73 #include <sys/mbuf.h>
  74 #include <sys/protosw.h>
  75 #include <sys/signalvar.h>
  76 #include <sys/socket.h>
  77 #include <sys/socketvar.h>
  78 #include <sys/sx.h>
  79 #include <sys/syslog.h>
  80 #include <sys/systm.h>
  81 #include <sys/time.h>
  82
  83 #include <net/if.h>
  84 #include <net/if_dl.h>
  85 #include <net/if_types.h>
  86 #include <net/route.h>
  87
  88 #include <netinet/in.h>
  89 #include <netinet/in_pcb.h>
  90 #include <netinet/in_var.h>
  91 #include <netinet/ip6.h>
  92 #include <netinet/icmp6.h>
  93 #include <netinet/tcp_var.h>
  94 #include <netinet6/in6_ifattach.h>
  95 #include <netinet6/in6_pcb.h>
  96 #include <netinet6/ip6protosw.h>
  97 #include <netinet6/ip6_var.h>
  98 #include <netinet6/scope6_var.h>
  99 #include <netinet6/mld6_var.h>
 100 #include <netinet6/nd6.h>
 101
 102 #ifdef IPSEC
 103 #include <netinet6/ipsec.h>
 104 #include <netkey/key.h>
 105 #endif
 106
 107 #ifdef FAST_IPSEC
 108 #include <netipsec/ipsec.h>
 109 #include <netipsec/key.h>
 110 #endif
 111
 112 #include <net/net_osdep.h>
 113
 114 extern struct domain inet6domain;
 115
 116 struct icmp6stat icmp6stat;
 117
 118 extern struct inpcbinfo ripcbinfo;
 119 extern struct inpcbhead ripcb;
 120 extern int icmp6errppslim;
 121 static int icmp6errpps_count = 0;
 122 static struct timeval icmp6errppslim_last;
 123 extern int icmp6_nodeinfo;
 124
 125 static void icmp6_errcount __P((struct icmp6errstat *, int, int));
 126 static int icmp6_rip6_input __P((struct mbuf **, int));
 127 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
 128 static const char *icmp6_redirect_diag __P((struct in6_addr *,
 129         struct in6_addr *, struct in6_addr *));
 130 static struct mbuf *ni6_input __P((struct mbuf *, int));
 131 static struct mbuf *ni6_nametodns __P((const char *, int, int));
 132 static int ni6_dnsmatch __P((const char *, int, const char *, int));
 133 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
 134                           struct ifnet **, struct in6_addr *));
 135 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 136                                 struct ifnet *, int));
 137 static int icmp6_notify_error __P((struct mbuf **, int, int, int));
 138
 139
 140 void
 141 icmp6_init()
 142 {
 143         mld6_init();
 144 }
 145
 146 static void
 147 icmp6_errcount(stat, type, code)
 148         struct icmp6errstat *stat;
 149         int type, code;
 150 {
 151         switch (type) {
 152         case ICMP6_DST_UNREACH:
 153                 switch (code) {
 154                 case ICMP6_DST_UNREACH_NOROUTE:
 155                         stat->icp6errs_dst_unreach_noroute++;
 156                         return;
 157                 case ICMP6_DST_UNREACH_ADMIN:
 158                         stat->icp6errs_dst_unreach_admin++;
 159                         return;
 160                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 161                         stat->icp6errs_dst_unreach_beyondscope++;
 162                         return;
 163                 case ICMP6_DST_UNREACH_ADDR:
 164                         stat->icp6errs_dst_unreach_addr++;
 165                         return;
 166                 case ICMP6_DST_UNREACH_NOPORT:
 167                         stat->icp6errs_dst_unreach_noport++;
 168                         return;
 169                 }
 170                 break;
 171         case ICMP6_PACKET_TOO_BIG:
 172                 stat->icp6errs_packet_too_big++;
 173                 return;
 174         case ICMP6_TIME_EXCEEDED:
 175                 switch (code) {
 176                 case ICMP6_TIME_EXCEED_TRANSIT:
 177                         stat->icp6errs_time_exceed_transit++;
 178                         return;
 179                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 180                         stat->icp6errs_time_exceed_reassembly++;
 181                         return;
 182                 }
 183                 break;
 184         case ICMP6_PARAM_PROB:
 185                 switch (code) {
 186                 case ICMP6_PARAMPROB_HEADER:
 187                         stat->icp6errs_paramprob_header++;
 188                         return;
 189                 case ICMP6_PARAMPROB_NEXTHEADER:
 190                         stat->icp6errs_paramprob_nextheader++;
 191                         return;
 192                 case ICMP6_PARAMPROB_OPTION:
 193                         stat->icp6errs_paramprob_option++;
 194                         return;
 195                 }
 196                 break;
 197         case ND_REDIRECT:
 198                 stat->icp6errs_redirect++;
 199                 return;
 200         }
 201         stat->icp6errs_unknown++;
 202 }
 203
 204 /*
 205  * A wrapper function for icmp6_error() necessary when the erroneous packet
 206  * may not contain enough scope zone information.
 207  */
 208 void
 209 icmp6_error2(m, type, code, param, ifp)
 210         struct mbuf *m;
 211         int type, code, param;
 212         struct ifnet *ifp;
 213 {
 214         struct ip6_hdr *ip6;
 215
 216         if (ifp == NULL)
 217                 return;
 218
 219 #ifndef PULLDOWN_TEST
 220         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 221 #else
 222         if (m->m_len < sizeof(struct ip6_hdr)) {
 223                 m = m_pullup(m, sizeof(struct ip6_hdr));
 224                 if (m == NULL)
 225                         return;
 226         }
 227 #endif
 228
 229         ip6 = mtod(m, struct ip6_hdr *);
 230
 231         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 232                 return;
 233         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 234                 return;
 235
 236         icmp6_error(m, type, code, param);
 237 }
 238
 239 /*
 240  * Generate an error packet of type error in response to bad IP6 packet.
 241  */
 242 void
 243 icmp6_error(m, type, code, param)
 244         struct mbuf *m;
 245         int type, code, param;
 246 {
 247         struct ip6_hdr *oip6, *nip6;
 248         struct icmp6_hdr *icmp6;
 249         u_int preplen;
 250         int off;
 251         int nxt;
 252
 253         icmp6stat.icp6s_error++;
 254
 255         /* count per-type-code statistics */
 256         icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
 257
 258 #ifdef M_DECRYPTED      /*not openbsd*/
 259         if (m->m_flags & M_DECRYPTED) {
 260                 icmp6stat.icp6s_canterror++;
 261                 goto freeit;
 262         }
 263 #endif
 264
 265 #ifndef PULLDOWN_TEST
 266         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 267 #else
 268         if (m->m_len < sizeof(struct ip6_hdr)) {
 269                 m = m_pullup(m, sizeof(struct ip6_hdr));
 270                 if (m == NULL)
 271                         return;
 272         }
 273 #endif
 274         oip6 = mtod(m, struct ip6_hdr *);
 275
 276         /*
 277          * If the destination address of the erroneous packet is a multicast
 278          * address, or the packet was sent using link-layer multicast,
 279          * we should basically suppress sending an error (RFC 2463, Section
 280          * 2.4).
 281          * We have two exceptions (the item e.2 in that section):
 282          * - the Pakcet Too Big message can be sent for path MTU discovery.
 283          * - the Parameter Problem Message that can be allowed an icmp6 error
 284          *   in the option type field.  This check has been done in
 285          *   ip6_unknown_opt(), so we can just check the type and code.
 286          */
 287         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 288              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 289             (type != ICMP6_PACKET_TOO_BIG &&
 290              (type != ICMP6_PARAM_PROB ||
 291               code != ICMP6_PARAMPROB_OPTION)))
 292                 goto freeit;
 293
 294         /*
 295          * RFC 2463, 2.4 (e.5): source address check.
 296          * XXX: the case of anycast source?
 297          */
 298         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 299             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 300                 goto freeit;
 301
 302         /*
 303          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 304          * don't do it.
 305          */
 306         nxt = -1;
 307         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 308         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 309                 struct icmp6_hdr *icp;
 310
 311 #ifndef PULLDOWN_TEST
 312                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 313                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 314 #else
 315                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 316                         sizeof(*icp));
 317                 if (icp == NULL) {
 318                         icmp6stat.icp6s_tooshort++;
 319                         return;
 320                 }
 321 #endif
 322                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 323                     icp->icmp6_type == ND_REDIRECT) {
 324                         /*
 325                          * ICMPv6 error
 326                          * Special case: for redirect (which is
 327                          * informational) we must not send icmp6 error.
 328                          */
 329                         icmp6stat.icp6s_canterror++;
 330                         goto freeit;
 331                 } else {
 332                         /* ICMPv6 informational - send the error */
 333                 }
 334         } else {
 335                 /* non-ICMPv6 - send the error */
 336         }
 337
 338         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 339
 340         /* Finally, do rate limitation check. */
 341         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 342                 icmp6stat.icp6s_toofreq++;
 343                 goto freeit;
 344         }
 345
 346         /*
 347          * OK, ICMP6 can be generated.
 348          */
 349
 350         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 351                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 352
 353         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 354         M_PREPEND(m, preplen, M_DONTWAIT);
 355         if (m && m->m_len < preplen)
 356                 m = m_pullup(m, preplen);
 357         if (m == NULL) {
 358                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 359                 return;
 360         }
 361
 362         nip6 = mtod(m, struct ip6_hdr *);
 363         nip6->ip6_src  = oip6->ip6_src;
 364         nip6->ip6_dst  = oip6->ip6_dst;
 365
 366         in6_clearscope(&oip6->ip6_src);
 367         in6_clearscope(&oip6->ip6_dst);
 368
 369         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 370         icmp6->icmp6_type = type;
 371         icmp6->icmp6_code = code;
 372         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 373
 374         /*
 375          * icmp6_reflect() is designed to be in the input path.
 376          * icmp6_error() can be called from both input and output path,
 377          * and if we are in output path rcvif could contain bogus value.
 378          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 379          * information in ip header (nip6).
 380          */
 381         m->m_pkthdr.rcvif = NULL;
 382
 383         icmp6stat.icp6s_outhist[type]++;
 384         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 385
 386         return;
 387
 388   freeit:
 389         /*
 390          * If we can't tell whether or not we can generate ICMP6, free it.
 391          */
 392         m_freem(m);
 393 }
 394
 395 /*
 396  * Process a received ICMP6 message.
 397  */
 398 int
 399 icmp6_input(mp, offp, proto)
 400         struct mbuf **mp;
 401         int *offp, proto;
 402 {
 403         struct mbuf *m = *mp, *n;
 404         struct ip6_hdr *ip6, *nip6;
 405         struct icmp6_hdr *icmp6, *nicmp6;
 406         int off = *offp;
 407         int icmp6len = m->m_pkthdr.len - *offp;
 408         int code, sum, noff;
 409
 410 #ifndef PULLDOWN_TEST
 411         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 412         /* m might change if M_LOOP.  So, call mtod after this */
 413 #endif
 414
 415         /*
 416          * Locate icmp6 structure in mbuf, and check
 417          * that not corrupted and of at least minimum length
 418          */
 419
 420         ip6 = mtod(m, struct ip6_hdr *);
 421         if (icmp6len < sizeof(struct icmp6_hdr)) {
 422                 icmp6stat.icp6s_tooshort++;
 423                 goto freeit;
 424         }
 425
 426         /*
 427          * calculate the checksum
 428          */
 429 #ifndef PULLDOWN_TEST
 430         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 431 #else
 432         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 433         if (icmp6 == NULL) {
 434                 icmp6stat.icp6s_tooshort++;
 435                 return IPPROTO_DONE;
 436         }
 437 #endif
 438         code = icmp6->icmp6_code;
 439
 440         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 441                 nd6log((LOG_ERR,
 442                     "ICMP6 checksum error(%d|%x) %s\n",
 443                     icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
 444                 icmp6stat.icp6s_checksum++;
 445                 goto freeit;
 446         }
 447
 448         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 449                 /*
 450                  * Deliver very specific ICMP6 type only.
 451                  * This is important to deliver TOOBIG.  Otherwise PMTUD
 452                  * will not work.
 453                  */
 454                 switch (icmp6->icmp6_type) {
 455                 case ICMP6_DST_UNREACH:
 456                 case ICMP6_PACKET_TOO_BIG:
 457                 case ICMP6_TIME_EXCEEDED:
 458                         break;
 459                 default:
 460                         goto freeit;
 461                 }
 462         }
 463
 464         icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
 465         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
 466         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 467                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
 468
 469         switch (icmp6->icmp6_type) {
 470         case ICMP6_DST_UNREACH:
 471                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
 472                 switch (code) {
 473                 case ICMP6_DST_UNREACH_NOROUTE:
 474                         code = PRC_UNREACH_NET;
 475                         break;
 476                 case ICMP6_DST_UNREACH_ADMIN:
 477                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
 478                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 479                         break;
 480                 case ICMP6_DST_UNREACH_ADDR:
 481                         code = PRC_HOSTDEAD;
 482                         break;
 483                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 484                         /* I mean "source address was incorrect." */
 485                         code = PRC_PARAMPROB;
 486                         break;
 487                 case ICMP6_DST_UNREACH_NOPORT:
 488                         code = PRC_UNREACH_PORT;
 489                         break;
 490                 default:
 491                         goto badcode;
 492                 }
 493                 goto deliver;
 494                 break;
 495
 496         case ICMP6_PACKET_TOO_BIG:
 497                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
 498
 499                 /* validation is made in icmp6_mtudisc_update */
 500
 501                 code = PRC_MSGSIZE;
 502
 503                 /*
 504                  * Updating the path MTU will be done after examining
 505                  * intermediate extension headers.
 506                  */
 507                 goto deliver;
 508                 break;
 509
 510         case ICMP6_TIME_EXCEEDED:
 511                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
 512                 switch (code) {
 513                 case ICMP6_TIME_EXCEED_TRANSIT:
 514                         code = PRC_TIMXCEED_INTRANS;
 515                         break;
 516                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 517                         code = PRC_TIMXCEED_REASS;
 518                         break;
 519                 default:
 520                         goto badcode;
 521                 }
 522                 goto deliver;
 523                 break;
 524
 525         case ICMP6_PARAM_PROB:
 526                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
 527                 switch (code) {
 528                 case ICMP6_PARAMPROB_NEXTHEADER:
 529                         code = PRC_UNREACH_PROTOCOL;
 530                         break;
 531                 case ICMP6_PARAMPROB_HEADER:
 532                 case ICMP6_PARAMPROB_OPTION:
 533                         code = PRC_PARAMPROB;
 534                         break;
 535                 default:
 536                         goto badcode;
 537                 }
 538                 goto deliver;
 539                 break;
 540
 541         case ICMP6_ECHO_REQUEST:
 542                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
 543                 if (code != 0)
 544                         goto badcode;
 545                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 546                         /* Give up remote */
 547                         break;
 548                 }
 549                 if ((n->m_flags & M_EXT) != 0
 550                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 551                         struct mbuf *n0 = n;
 552                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 553                         int n0len;
 554
 555                         MGETHDR(n, M_DONTWAIT, n0->m_type);
 556                         n0len = n0->m_pkthdr.len;       /* save for use below */
 557                         if (n)
 558                                 M_MOVE_PKTHDR(n, n0);
 559                         if (n && maxlen >= MHLEN) {
 560                                 MCLGET(n, M_DONTWAIT);
 561                                 if ((n->m_flags & M_EXT) == 0) {
 562                                         m_free(n);
 563                                         n = NULL;
 564                                 }
 565                         }
 566                         if (n == NULL) {
 567                                 /* Give up remote */
 568                                 m_freem(n0);
 569                                 break;
 570                         }
 571                         /*
 572                          * Copy IPv6 and ICMPv6 only.
 573                          */
 574                         nip6 = mtod(n, struct ip6_hdr *);
 575                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 576                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 577                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 578                         noff = sizeof(struct ip6_hdr);
 579                         /* new mbuf contains only ipv6+icmpv6 headers */
 580                         n->m_len = noff + sizeof(struct icmp6_hdr);
 581                         /*
 582                          * Adjust mbuf.  ip6_plen will be adjusted in
 583                          * ip6_output().
 584                          */
 585                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 586                         /* recalculate complete packet size */
 587                         n->m_pkthdr.len = n0len + (noff - off);
 588                         n->m_next = n0;
 589                 } else {
 590                         nip6 = mtod(n, struct ip6_hdr *);
 591                         nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
 592                         noff = off;
 593                 }
 594                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 595                 nicmp6->icmp6_code = 0;
 596                 if (n) {
 597                         icmp6stat.icp6s_reflect++;
 598                         icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
 599                         icmp6_reflect(n, noff);
 600                 }
 601                 break;
 602
 603         case ICMP6_ECHO_REPLY:
 604                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
 605                 if (code != 0)
 606                         goto badcode;
 607                 break;
 608
 609         case MLD_LISTENER_QUERY:
 610         case MLD_LISTENER_REPORT:
 611                 if (icmp6len < sizeof(struct mld_hdr))
 612                         goto badlen;
 613                 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
 614                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
 615                 else
 616                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
 617                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 618                         /* give up local */
 619                         mld6_input(m, off);
 620                         m = NULL;
 621                         goto freeit;
 622                 }
 623                 mld6_input(n, off);
 624                 /* m stays. */
 625                 break;
 626
 627         case MLD_LISTENER_DONE:
 628                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
 629                 if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
 630                         goto badlen;
 631                 break;          /* nothing to be done in kernel */
 632
 633         case MLD_MTRACE_RESP:
 634         case MLD_MTRACE:
 635                 /* XXX: these two are experimental.  not officially defined. */
 636                 /* XXX: per-interface statistics? */
 637                 break;          /* just pass it to applications */
 638
 639         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 640             {
 641                 enum { WRU, FQDN } mode;
 642
 643                 if (!icmp6_nodeinfo)
 644                         break;
 645
 646                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 647                         mode = WRU;
 648                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 649                         mode = FQDN;
 650                 else
 651                         goto badlen;
 652
 653 #define hostnamelen     strlen(hostname)
 654                 if (mode == FQDN) {
 655 #ifndef PULLDOWN_TEST
 656                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 657                             IPPROTO_DONE);
 658 #endif
 659                         n = m_copy(m, 0, M_COPYALL);
 660                         if (n)
 661                                 n = ni6_input(n, off);
 662                         /* XXX meaningless if n == NULL */
 663                         noff = sizeof(struct ip6_hdr);
 664                 } else {
 665                         u_char *p;
 666                         int maxlen, maxhlen;
 667
 668                         if ((icmp6_nodeinfo & 5) != 5)
 669                                 break;
 670
 671                         if (code != 0)
 672                                 goto badcode;
 673                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 674                         if (maxlen >= MCLBYTES) {
 675                                 /* Give up remote */
 676                                 break;
 677                         }
 678                         MGETHDR(n, M_DONTWAIT, m->m_type);
 679                         if (n && maxlen > MHLEN) {
 680                                 MCLGET(n, M_DONTWAIT);
 681                                 if ((n->m_flags & M_EXT) == 0) {
 682                                         m_free(n);
 683                                         n = NULL;
 684                                 }
 685                         }
 686                         if (!m_dup_pkthdr(n, m, M_DONTWAIT)) {
 687                                 /*
 688                                  * Previous code did a blind M_COPY_PKTHDR
 689                                  * and said "just for rcvif".  If true, then
 690                                  * we could tolerate the dup failing (due to
 691                                  * the deep copy of the tag chain).  For now
 692                                  * be conservative and just fail.
 693                                  */
 694                                 m_free(n);
 695                                 n = NULL;
 696                         }
 697                         if (n == NULL) {
 698                                 /* Give up remote */
 699                                 break;
 700                         }
 701                         n->m_pkthdr.rcvif = NULL;
 702                         n->m_len = 0;
 703                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 704                         if (maxhlen > hostnamelen)
 705                                 maxhlen = hostnamelen;
 706                         /*
 707                          * Copy IPv6 and ICMPv6 only.
 708                          */
 709                         nip6 = mtod(n, struct ip6_hdr *);
 710                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 711                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 712                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 713                         p = (u_char *)(nicmp6 + 1);
 714                         bzero(p, 4);
 715                         bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
 716                         noff = sizeof(struct ip6_hdr);
 717                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 718                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 719                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 720                         nicmp6->icmp6_code = 0;
 721                 }
 722 #undef hostnamelen
 723                 if (n) {
 724                         icmp6stat.icp6s_reflect++;
 725                         icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
 726                         icmp6_reflect(n, noff);
 727                 }
 728                 break;
 729             }
 730
 731         case ICMP6_WRUREPLY:
 732                 if (code != 0)
 733                         goto badcode;
 734                 break;
 735
 736         case ND_ROUTER_SOLICIT:
 737                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
 738                 if (code != 0)
 739                         goto badcode;
 740                 if (icmp6len < sizeof(struct nd_router_solicit))
 741                         goto badlen;
 742                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 743                         /* give up local */
 744                         nd6_rs_input(m, off, icmp6len);
 745                         m = NULL;
 746                         goto freeit;
 747                 }
 748                 nd6_rs_input(n, off, icmp6len);
 749                 /* m stays. */
 750                 break;
 751
 752         case ND_ROUTER_ADVERT:
 753                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
 754                 if (code != 0)
 755                         goto badcode;
 756                 if (icmp6len < sizeof(struct nd_router_advert))
 757                         goto badlen;
 758                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 759                         /* give up local */
 760                         nd6_ra_input(m, off, icmp6len);
 761                         m = NULL;
 762                         goto freeit;
 763                 }
 764                 nd6_ra_input(n, off, icmp6len);
 765                 /* m stays. */
 766                 break;
 767
 768         case ND_NEIGHBOR_SOLICIT:
 769                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
 770                 if (code != 0)
 771                         goto badcode;
 772                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 773                         goto badlen;
 774                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 775                         /* give up local */
 776                         nd6_ns_input(m, off, icmp6len);
 777                         m = NULL;
 778                         goto freeit;
 779                 }
 780                 nd6_ns_input(n, off, icmp6len);
 781                 /* m stays. */
 782                 break;
 783
 784         case ND_NEIGHBOR_ADVERT:
 785                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
 786                 if (code != 0)
 787                         goto badcode;
 788                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 789                         goto badlen;
 790                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 791                         /* give up local */
 792                         nd6_na_input(m, off, icmp6len);
 793                         m = NULL;
 794                         goto freeit;
 795                 }
 796                 nd6_na_input(n, off, icmp6len);
 797                 /* m stays. */
 798                 break;
 799
 800         case ND_REDIRECT:
 801                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
 802                 if (code != 0)
 803                         goto badcode;
 804                 if (icmp6len < sizeof(struct nd_redirect))
 805                         goto badlen;
 806                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 807                         /* give up local */
 808                         icmp6_redirect_input(m, off);
 809                         m = NULL;
 810                         goto freeit;
 811                 }
 812                 icmp6_redirect_input(n, off);
 813                 /* m stays. */
 814                 break;
 815
 816         case ICMP6_ROUTER_RENUMBERING:
 817                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 818                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 819                         goto badcode;
 820                 if (icmp6len < sizeof(struct icmp6_router_renum))
 821                         goto badlen;
 822                 break;
 823
 824         default:
 825                 nd6log((LOG_DEBUG,
 826                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 827                     icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
 828                     ip6_sprintf(&ip6->ip6_dst),
 829                     m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
 830                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 831                         /* ICMPv6 error: MUST deliver it by spec... */
 832                         code = PRC_NCMDS;
 833                         /* deliver */
 834                 } else {
 835                         /* ICMPv6 informational: MUST not deliver */
 836                         break;
 837                 }
 838         deliver:
 839                 if (icmp6_notify_error(&m, off, icmp6len, code)) {
 840                         /* In this case, m should've been freed. */
 841                         return (IPPROTO_DONE);
 842                 }
 843                 break;
 844
 845         badcode:
 846                 icmp6stat.icp6s_badcode++;
 847                 break;
 848
 849         badlen:
 850                 icmp6stat.icp6s_badlen++;
 851                 break;
 852         }
 853
 854         /* deliver the packet to appropriate sockets */
 855         icmp6_rip6_input(&m, *offp);
 856
 857         return IPPROTO_DONE;
 858
 859  freeit:
 860         m_freem(m);
 861         return IPPROTO_DONE;
 862 }
 863
 864 static int
 865 icmp6_notify_error(mp, off, icmp6len, code)
 866         struct mbuf **mp;
 867         int off, icmp6len, code;
 868 {
 869         struct mbuf *m = *mp;
 870         struct icmp6_hdr *icmp6;
 871         struct ip6_hdr *eip6;
 872         u_int32_t notifymtu;
 873         struct sockaddr_in6 icmp6src, icmp6dst;
 874
 875         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 876                 icmp6stat.icp6s_tooshort++;
 877                 goto freeit;
 878         }
 879 #ifndef PULLDOWN_TEST
 880         IP6_EXTHDR_CHECK(m, off,
 881             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 882         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 883 #else
 884         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 885             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 886         if (icmp6 == NULL) {
 887                 icmp6stat.icp6s_tooshort++;
 888                 return (-1);
 889         }
 890 #endif
 891         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 892
 893         /* Detect the upper level protocol */
 894         {
 895                 void (*ctlfunc) __P((int, struct sockaddr *, void *));
 896                 u_int8_t nxt = eip6->ip6_nxt;
 897                 int eoff = off + sizeof(struct icmp6_hdr) +
 898                     sizeof(struct ip6_hdr);
 899                 struct ip6ctlparam ip6cp;
 900                 struct in6_addr *finaldst = NULL;
 901                 int icmp6type = icmp6->icmp6_type;
 902                 struct ip6_frag *fh;
 903                 struct ip6_rthdr *rth;
 904                 struct ip6_rthdr0 *rth0;
 905                 int rthlen;
 906
 907                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 908                         struct ip6_ext *eh;
 909
 910                         switch (nxt) {
 911                         case IPPROTO_HOPOPTS:
 912                         case IPPROTO_DSTOPTS:
 913                         case IPPROTO_AH:
 914 #ifndef PULLDOWN_TEST
 915                                 IP6_EXTHDR_CHECK(m, 0,
 916                                     eoff + sizeof(struct ip6_ext), -1);
 917                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 918 #else
 919                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 920                                     eoff, sizeof(*eh));
 921                                 if (eh == NULL) {
 922                                         icmp6stat.icp6s_tooshort++;
 923                                         return (-1);
 924                                 }
 925 #endif
 926
 927                                 if (nxt == IPPROTO_AH)
 928                                         eoff += (eh->ip6e_len + 2) << 2;
 929                                 else
 930                                         eoff += (eh->ip6e_len + 1) << 3;
 931                                 nxt = eh->ip6e_nxt;
 932                                 break;
 933                         case IPPROTO_ROUTING:
 934                                 /*
 935                                  * When the erroneous packet contains a
 936                                  * routing header, we should examine the
 937                                  * header to determine the final destination.
 938                                  * Otherwise, we can't properly update
 939                                  * information that depends on the final
 940                                  * destination (e.g. path MTU).
 941                                  */
 942 #ifndef PULLDOWN_TEST
 943                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 944                                 rth = (struct ip6_rthdr *)
 945                                     (mtod(m, caddr_t) + eoff);
 946 #else
 947                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 948                                     eoff, sizeof(*rth));
 949                                 if (rth == NULL) {
 950                                         icmp6stat.icp6s_tooshort++;
 951                                         return (-1);
 952                                 }
 953 #endif
 954                                 rthlen = (rth->ip6r_len + 1) << 3;
 955                                 /*
 956                                  * XXX: currently there is no
 957                                  * officially defined type other
 958                                  * than type-0.
 959                                  * Note that if the segment left field
 960                                  * is 0, all intermediate hops must
 961                                  * have been passed.
 962                                  */
 963                                 if (rth->ip6r_segleft &&
 964                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 965                                         int hops;
 966
 967 #ifndef PULLDOWN_TEST
 968                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 969                                         rth0 = (struct ip6_rthdr0 *)
 970                                             (mtod(m, caddr_t) + eoff);
 971 #else
 972                                         IP6_EXTHDR_GET(rth0,
 973                                             struct ip6_rthdr0 *, m,
 974                                             eoff, rthlen);
 975                                         if (rth0 == NULL) {
 976                                                 icmp6stat.icp6s_tooshort++;
 977                                                 return (-1);
 978                                         }
 979 #endif
 980                                         /* just ignore a bogus header */
 981                                         if ((rth0->ip6r0_len % 2) == 0 &&
 982                                             (hops = rth0->ip6r0_len/2))
 983                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 984                                 }
 985                                 eoff += rthlen;
 986                                 nxt = rth->ip6r_nxt;
 987                                 break;
 988                         case IPPROTO_FRAGMENT:
 989 #ifndef PULLDOWN_TEST
 990                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 991                                     sizeof(struct ip6_frag), -1);
 992                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
 993                                     eoff);
 994 #else
 995                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
 996                                     eoff, sizeof(*fh));
 997                                 if (fh == NULL) {
 998                                         icmp6stat.icp6s_tooshort++;
 999                                         return (-1);
1000                                 }
1001 #endif
1002                                 /*
1003                                  * Data after a fragment header is meaningless
1004                                  * unless it is the first fragment, but
1005                                  * we'll go to the notify label for path MTU
1006                                  * discovery.
1007                                  */
1008                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1009                                         goto notify;
1010
1011                                 eoff += sizeof(struct ip6_frag);
1012                                 nxt = fh->ip6f_nxt;
1013                                 break;
1014                         default:
1015                                 /*
1016                                  * This case includes ESP and the No Next
1017                                  * Header.  In such cases going to the notify
1018                                  * label does not have any meaning
1019                                  * (i.e. ctlfunc will be NULL), but we go
1020                                  * anyway since we might have to update
1021                                  * path MTU information.
1022                                  */
1023                                 goto notify;
1024                         }
1025                 }
1026           notify:
1027 #ifndef PULLDOWN_TEST
1028                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1029 #else
1030                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1031                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1032                 if (icmp6 == NULL) {
1033                         icmp6stat.icp6s_tooshort++;
1034                         return (-1);
1035                 }
1036 #endif
1037
1038                 /*
1039                  * retrieve parameters from the inner IPv6 header, and convert
1040                  * them into sockaddr structures.
1041                  * XXX: there is no guarantee that the source or destination
1042                  * addresses of the inner packet are in the same scope as
1043                  * the addresses of the icmp packet.  But there is no other
1044                  * way to determine the zone.
1045                  */
1046                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1047
1048                 bzero(&icmp6dst, sizeof(icmp6dst));
1049                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1050                 icmp6dst.sin6_family = AF_INET6;
1051                 if (finaldst == NULL)
1052                         icmp6dst.sin6_addr = eip6->ip6_dst;
1053                 else
1054                         icmp6dst.sin6_addr = *finaldst;
1055                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1056                         goto freeit;
1057                 bzero(&icmp6src, sizeof(icmp6src));
1058                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1059                 icmp6src.sin6_family = AF_INET6;
1060                 icmp6src.sin6_addr = eip6->ip6_src;
1061                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1062                         goto freeit;
1063                 icmp6src.sin6_flowinfo =
1064                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1065
1066                 if (finaldst == NULL)
1067                         finaldst = &eip6->ip6_dst;
1068                 ip6cp.ip6c_m = m;
1069                 ip6cp.ip6c_icmp6 = icmp6;
1070                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1071                 ip6cp.ip6c_off = eoff;
1072                 ip6cp.ip6c_finaldst = finaldst;
1073                 ip6cp.ip6c_src = &icmp6src;
1074                 ip6cp.ip6c_nxt = nxt;
1075
1076                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1077                         notifymtu = ntohl(icmp6->icmp6_mtu);
1078                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1079                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1080                 }
1081
1082                 ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
1083                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1084                 if (ctlfunc) {
1085                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1086                             &ip6cp);
1087                 }
1088         }
1089         *mp = m;
1090         return (0);
1091
1092   freeit:
1093         m_freem(m);
1094         return (-1);
1095 }
1096
1097 void
1098 icmp6_mtudisc_update(ip6cp, validated)
1099         struct ip6ctlparam *ip6cp;
1100         int validated;
1101 {
1102         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1103         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1104         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1105         u_int mtu = ntohl(icmp6->icmp6_mtu);
1106         struct in_conninfo inc;
1107
1108 #if 0
1109         /*
1110          * RFC2460 section 5, last paragraph.
1111          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1112          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1113          * due to packet translator in the middle.
1114          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1115          * special handling.
1116          */
1117         if (mtu < IPV6_MMTU)
1118                 return;
1119 #endif
1120
1121         /*
1122          * we reject ICMPv6 too big with abnormally small value.
1123          * XXX what is the good definition of "abnormally small"?
1124          */
1125         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1126                 return;
1127
1128         if (!validated)
1129                 return;
1130
1131         bzero(&inc, sizeof(inc));
1132         inc.inc_flags = 1; /* IPv6 */
1133         inc.inc6_faddr = *dst;
1134         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1135                 return;
1136
1137         if (mtu < tcp_maxmtu6(&inc)) {
1138                 tcp_hc_updatemtu(&inc, mtu);
1139                 icmp6stat.icp6s_pmtuchg++;
1140         }
1141 }
1142
1143 /*
1144  * Process a Node Information Query packet, based on
1145  * draft-ietf-ipngwg-icmp-name-lookups-07.
1146  *
1147  * Spec incompatibilities:
1148  * - IPv6 Subject address handling
1149  * - IPv4 Subject address handling support missing
1150  * - Proxy reply (answer even if it's not for me)
1151  * - joins NI group address at in6_ifattach() time only, does not cope
1152  *   with hostname changes by sethostname(3)
1153  */
1154 #define hostnamelen     strlen(hostname)
1155 static struct mbuf *
1156 ni6_input(m, off)
1157         struct mbuf *m;
1158         int off;
1159 {
1160         struct icmp6_nodeinfo *ni6, *nni6;
1161         struct mbuf *n = NULL;
1162         u_int16_t qtype;
1163         int subjlen;
1164         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1165         struct ni_reply_fqdn *fqdn;
1166         int addrs;              /* for NI_QTYPE_NODEADDR */
1167         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1168         struct in6_addr in6_subj; /* subject address */
1169         struct ip6_hdr *ip6;
1170         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1171         char *subj = NULL;
1172         struct in6_ifaddr *ia6 = NULL;
1173
1174         ip6 = mtod(m, struct ip6_hdr *);
1175 #ifndef PULLDOWN_TEST
1176         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1177 #else
1178         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1179         if (ni6 == NULL) {
1180                 /* m is already reclaimed */
1181                 return (NULL);
1182         }
1183 #endif
1184
1185         /*
1186          * Validate IPv6 destination address.
1187          *
1188          * The Responder must discard the Query without further processing
1189          * unless it is one of the Responder's unicast or anycast addresses, or
1190          * a link-local scope multicast address which the Responder has joined.
1191          * [icmp-name-lookups-08, Section 4.]
1192          */
1193         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1194                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1195                         goto bad;
1196                 /* else it's a link-local multicast, fine */
1197         } else {                /* unicast or anycast */
1198                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1199                         goto bad; /* XXX impossible */
1200
1201                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1202                     !(icmp6_nodeinfo & 4)) {
1203                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1204                                 "a temporary address in %s:%d",
1205                                __FILE__, __LINE__));
1206                         goto bad;
1207                 }
1208         }
1209
1210         /* validate query Subject field. */
1211         qtype = ntohs(ni6->ni_qtype);
1212         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1213         switch (qtype) {
1214         case NI_QTYPE_NOOP:
1215         case NI_QTYPE_SUPTYPES:
1216                 /* 07 draft */
1217                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1218                         break;
1219                 /* FALLTHROUGH */
1220         case NI_QTYPE_FQDN:
1221         case NI_QTYPE_NODEADDR:
1222         case NI_QTYPE_IPV4ADDR:
1223                 switch (ni6->ni_code) {
1224                 case ICMP6_NI_SUBJ_IPV6:
1225 #if ICMP6_NI_SUBJ_IPV6 != 0
1226                 case 0:
1227 #endif
1228                         /*
1229                          * backward compatibility - try to accept 03 draft
1230                          * format, where no Subject is present.
1231                          */
1232                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1233                             subjlen == 0) {
1234                                 oldfqdn++;
1235                                 break;
1236                         }
1237 #if ICMP6_NI_SUBJ_IPV6 != 0
1238                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1239                                 goto bad;
1240 #endif
1241
1242                         if (subjlen != sizeof(struct in6_addr))
1243                                 goto bad;
1244
1245                         /*
1246                          * Validate Subject address.
1247                          *
1248                          * Not sure what exactly "address belongs to the node"
1249                          * means in the spec, is it just unicast, or what?
1250                          *
1251                          * At this moment we consider Subject address as
1252                          * "belong to the node" if the Subject address equals
1253                          * to the IPv6 destination address; validation for
1254                          * IPv6 destination address should have done enough
1255                          * check for us.
1256                          *
1257                          * We do not do proxy at this moment.
1258                          */
1259                         /* m_pulldown instead of copy? */
1260                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1261                             subjlen, (caddr_t)&in6_subj);
1262                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1263                                 goto bad;
1264
1265                         subj = (char *)&in6_subj;
1266                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1267                                 break;
1268
1269                         /*
1270                          * XXX if we are to allow other cases, we should really
1271                          * be careful about scope here.
1272                          * basically, we should disallow queries toward IPv6
1273                          * destination X with subject Y,
1274                          * if scope(X) > scope(Y).
1275                          * if we allow scope(X) > scope(Y), it will result in
1276                          * information leakage across scope boundary.
1277                          */
1278                         goto bad;
1279
1280                 case ICMP6_NI_SUBJ_FQDN:
1281                         /*
1282                          * Validate Subject name with gethostname(3).
1283                          *
1284                          * The behavior may need some debate, since:
1285                          * - we are not sure if the node has FQDN as
1286                          *   hostname (returned by gethostname(3)).
1287                          * - the code does wildcard match for truncated names.
1288                          *   however, we are not sure if we want to perform
1289                          *   wildcard match, if gethostname(3) side has
1290                          *   truncated hostname.
1291                          */
1292                         n = ni6_nametodns(hostname, hostnamelen, 0);
1293                         if (!n || n->m_next || n->m_len == 0)
1294                                 goto bad;
1295                         IP6_EXTHDR_GET(subj, char *, m,
1296                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1297                         if (subj == NULL)
1298                                 goto bad;
1299                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1300                             n->m_len)) {
1301                                 goto bad;
1302                         }
1303                         m_freem(n);
1304                         n = NULL;
1305                         break;
1306
1307                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1308                 default:
1309                         goto bad;
1310                 }
1311                 break;
1312         }
1313
1314         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1315         switch (qtype) {
1316         case NI_QTYPE_FQDN:
1317                 if ((icmp6_nodeinfo & 1) == 0)
1318                         goto bad;
1319                 break;
1320         case NI_QTYPE_NODEADDR:
1321         case NI_QTYPE_IPV4ADDR:
1322                 if ((icmp6_nodeinfo & 2) == 0)
1323                         goto bad;
1324                 break;
1325         }
1326
1327         /* guess reply length */
1328         switch (qtype) {
1329         case NI_QTYPE_NOOP:
1330                 break;          /* no reply data */
1331         case NI_QTYPE_SUPTYPES:
1332                 replylen += sizeof(u_int32_t);
1333                 break;
1334         case NI_QTYPE_FQDN:
1335                 /* XXX will append an mbuf */
1336                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1337                 break;
1338         case NI_QTYPE_NODEADDR:
1339                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1340                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1341                     sizeof(u_int32_t))) > MCLBYTES)
1342                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1343                 break;
1344         case NI_QTYPE_IPV4ADDR:
1345                 /* unsupported - should respond with unknown Qtype? */
1346                 break;
1347         default:
1348                 /*
1349                  * XXX: We must return a reply with the ICMP6 code
1350                  * `unknown Qtype' in this case.  However we regard the case
1351                  * as an FQDN query for backward compatibility.
1352                  * Older versions set a random value to this field,
1353                  * so it rarely varies in the defined qtypes.
1354                  * But the mechanism is not reliable...
1355                  * maybe we should obsolete older versions.
1356                  */
1357                 qtype = NI_QTYPE_FQDN;
1358                 /* XXX will append an mbuf */
1359                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1360                 oldfqdn++;
1361                 break;
1362         }
1363
1364         /* allocate an mbuf to reply. */
1365         MGETHDR(n, M_DONTWAIT, m->m_type);
1366         if (n == NULL) {
1367                 m_freem(m);
1368                 return (NULL);
1369         }
1370         M_MOVE_PKTHDR(n, m); /* just for recvif */
1371         if (replylen > MHLEN) {
1372                 if (replylen > MCLBYTES) {
1373                         /*
1374                          * XXX: should we try to allocate more? But MCLBYTES
1375                          * is probably much larger than IPV6_MMTU...
1376                          */
1377                         goto bad;
1378                 }
1379                 MCLGET(n, M_DONTWAIT);
1380                 if ((n->m_flags & M_EXT) == 0) {
1381                         goto bad;
1382                 }
1383         }
1384         n->m_pkthdr.len = n->m_len = replylen;
1385
1386         /* copy mbuf header and IPv6 + Node Information base headers */
1387         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1388         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1389         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1390
1391         /* qtype dependent procedure */
1392         switch (qtype) {
1393         case NI_QTYPE_NOOP:
1394                 nni6->ni_code = ICMP6_NI_SUCCESS;
1395                 nni6->ni_flags = 0;
1396                 break;
1397         case NI_QTYPE_SUPTYPES:
1398         {
1399                 u_int32_t v;
1400                 nni6->ni_code = ICMP6_NI_SUCCESS;
1401                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1402                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1403                 v = (u_int32_t)htonl(0x0000000f);
1404                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1405                 break;
1406         }
1407         case NI_QTYPE_FQDN:
1408                 nni6->ni_code = ICMP6_NI_SUCCESS;
1409                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1410                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1411                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1412                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1413                 /*
1414                  * XXX do we really have FQDN in variable "hostname"?
1415                  */
1416                 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1417                 if (n->m_next == NULL)
1418                         goto bad;
1419                 /* XXX we assume that n->m_next is not a chain */
1420                 if (n->m_next->m_next != NULL)
1421                         goto bad;
1422                 n->m_pkthdr.len += n->m_next->m_len;
1423                 break;
1424         case NI_QTYPE_NODEADDR:
1425         {
1426                 int lenlim, copied;
1427
1428                 nni6->ni_code = ICMP6_NI_SUCCESS;
1429                 n->m_pkthdr.len = n->m_len =
1430                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1431                 lenlim = M_TRAILINGSPACE(n);
1432                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1433                 /* XXX: reset mbuf length */
1434                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1435                     sizeof(struct icmp6_nodeinfo) + copied;
1436                 break;
1437         }
1438         default:
1439                 break;          /* XXX impossible! */
1440         }
1441
1442         nni6->ni_type = ICMP6_NI_REPLY;
1443         m_freem(m);
1444         return (n);
1445
1446   bad:
1447         m_freem(m);
1448         if (n)
1449                 m_freem(n);
1450         return (NULL);
1451 }
1452 #undef hostnamelen
1453
1454 /*
1455  * make a mbuf with DNS-encoded string.  no compression support.
1456  *
1457  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1458  * treated as truncated name (two \0 at the end).  this is a wild guess.
1459  */
1460 static struct mbuf *
1461 ni6_nametodns(name, namelen, old)
1462         const char *name;
1463         int namelen;
1464         int old;        /* return pascal string if non-zero */
1465 {
1466         struct mbuf *m;
1467         char *cp, *ep;
1468         const char *p, *q;
1469         int i, len, nterm;
1470
1471         if (old)
1472                 len = namelen + 1;
1473         else
1474                 len = MCLBYTES;
1475
1476         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1477         MGET(m, M_DONTWAIT, MT_DATA);
1478         if (m && len > MLEN) {
1479                 MCLGET(m, M_DONTWAIT);
1480                 if ((m->m_flags & M_EXT) == 0)
1481                         goto fail;
1482         }
1483         if (!m)
1484                 goto fail;
1485         m->m_next = NULL;
1486
1487         if (old) {
1488                 m->m_len = len;
1489                 *mtod(m, char *) = namelen;
1490                 bcopy(name, mtod(m, char *) + 1, namelen);
1491                 return m;
1492         } else {
1493                 m->m_len = 0;
1494                 cp = mtod(m, char *);
1495                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1496
1497                 /* if not certain about my name, return empty buffer */
1498                 if (namelen == 0)
1499                         return m;
1500
1501                 /*
1502                  * guess if it looks like shortened hostname, or FQDN.
1503                  * shortened hostname needs two trailing "\0".
1504                  */
1505                 i = 0;
1506                 for (p = name; p < name + namelen; p++) {
1507                         if (*p && *p == '.')
1508                                 i++;
1509                 }
1510                 if (i < 2)
1511                         nterm = 2;
1512                 else
1513                         nterm = 1;
1514
1515                 p = name;
1516                 while (cp < ep && p < name + namelen) {
1517                         i = 0;
1518                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1519                                 i++;
1520                         /* result does not fit into mbuf */
1521                         if (cp + i + 1 >= ep)
1522                                 goto fail;
1523                         /*
1524                          * DNS label length restriction, RFC1035 page 8.
1525                          * "i == 0" case is included here to avoid returning
1526                          * 0-length label on "foo..bar".
1527                          */
1528                         if (i <= 0 || i >= 64)
1529                                 goto fail;
1530                         *cp++ = i;
1531                         bcopy(p, cp, i);
1532                         cp += i;
1533                         p = q;
1534                         if (p < name + namelen && *p == '.')
1535                                 p++;
1536                 }
1537                 /* termination */
1538                 if (cp + nterm >= ep)
1539                         goto fail;
1540                 while (nterm-- > 0)
1541                         *cp++ = '\0';
1542                 m->m_len = cp - mtod(m, char *);
1543                 return m;
1544         }
1545
1546         panic("should not reach here");
1547         /* NOTREACHED */
1548
1549  fail:
1550         if (m)
1551                 m_freem(m);
1552         return NULL;
1553 }
1554
1555 /*
1556  * check if two DNS-encoded string matches.  takes care of truncated
1557  * form (with \0\0 at the end).  no compression support.
1558  * XXX upper/lowercase match (see RFC2065)
1559  */
1560 static int
1561 ni6_dnsmatch(a, alen, b, blen)
1562         const char *a;
1563         int alen;
1564         const char *b;
1565         int blen;
1566 {
1567         const char *a0, *b0;
1568         int l;
1569
1570         /* simplest case - need validation? */
1571         if (alen == blen && bcmp(a, b, alen) == 0)
1572                 return 1;
1573
1574         a0 = a;
1575         b0 = b;
1576
1577         /* termination is mandatory */
1578         if (alen < 2 || blen < 2)
1579                 return 0;
1580         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1581                 return 0;
1582         alen--;
1583         blen--;
1584
1585         while (a - a0 < alen && b - b0 < blen) {
1586                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1587                         return 0;
1588
1589                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1590                         return 0;
1591                 /* we don't support compression yet */
1592                 if (a[0] >= 64 || b[0] >= 64)
1593                         return 0;
1594
1595                 /* truncated case */
1596                 if (a[0] == 0 && a - a0 == alen - 1)
1597                         return 1;
1598                 if (b[0] == 0 && b - b0 == blen - 1)
1599                         return 1;
1600                 if (a[0] == 0 || b[0] == 0)
1601                         return 0;
1602
1603                 if (a[0] != b[0])
1604                         return 0;
1605                 l = a[0];
1606                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1607                         return 0;
1608                 if (bcmp(a + 1, b + 1, l) != 0)
1609                         return 0;
1610
1611                 a += 1 + l;
1612                 b += 1 + l;
1613         }
1614
1615         if (a - a0 == alen && b - b0 == blen)
1616                 return 1;
1617         else
1618                 return 0;
1619 }
1620
1621 /*
1622  * calculate the number of addresses to be returned in the node info reply.
1623  */
1624 static int
1625 ni6_addrs(ni6, m, ifpp, subj)
1626         struct icmp6_nodeinfo *ni6;
1627         struct mbuf *m;
1628         struct ifnet **ifpp;
1629         struct in6_addr *subj;
1630 {
1631         struct ifnet *ifp;
1632         struct in6_ifaddr *ifa6;
1633         struct ifaddr *ifa;
1634         int addrs = 0, addrsofif, iffound = 0;
1635         int niflags = ni6->ni_flags;
1636
1637         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1638                 switch (ni6->ni_code) {
1639                 case ICMP6_NI_SUBJ_IPV6:
1640                         if (subj == NULL) /* must be impossible... */
1641                                 return (0);
1642                         break;
1643                 default:
1644                         /*
1645                          * XXX: we only support IPv6 subject address for
1646                          * this Qtype.
1647                          */
1648                         return (0);
1649                 }
1650         }
1651
1652         IFNET_RLOCK();
1653         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1654                 addrsofif = 0;
1655                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1656                         if (ifa->ifa_addr->sa_family != AF_INET6)
1657                                 continue;
1658                         ifa6 = (struct in6_ifaddr *)ifa;
1659
1660                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1661                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1662                                 iffound = 1;
1663
1664                         /*
1665                          * IPv4-mapped addresses can only be returned by a
1666                          * Node Information proxy, since they represent
1667                          * addresses of IPv4-only nodes, which perforce do
1668                          * not implement this protocol.
1669                          * [icmp-name-lookups-07, Section 5.4]
1670                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1671                          * this function at this moment.
1672                          */
1673
1674                         /* What do we have to do about ::1? */
1675                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1676                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1677                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1678                                         continue;
1679                                 break;
1680                         case IPV6_ADDR_SCOPE_SITELOCAL:
1681                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1682                                         continue;
1683                                 break;
1684                         case IPV6_ADDR_SCOPE_GLOBAL:
1685                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1686                                         continue;
1687                                 break;
1688                         default:
1689                                 continue;
1690                         }
1691
1692                         /*
1693                          * check if anycast is okay.
1694                          * XXX: just experimental.  not in the spec.
1695                          */
1696                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1697                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1698                                 continue; /* we need only unicast addresses */
1699                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1700                             (icmp6_nodeinfo & 4) == 0) {
1701                                 continue;
1702                         }
1703                         addrsofif++; /* count the address */
1704                 }
1705                 if (iffound) {
1706                         *ifpp = ifp;
1707                         IFNET_RUNLOCK();
1708                         return (addrsofif);
1709                 }
1710
1711                 addrs += addrsofif;
1712         }
1713         IFNET_RUNLOCK();
1714
1715         return (addrs);
1716 }
1717
1718 static int
1719 ni6_store_addrs(ni6, nni6, ifp0, resid)
1720         struct icmp6_nodeinfo *ni6, *nni6;
1721         struct ifnet *ifp0;
1722         int resid;
1723 {
1724         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1725         struct in6_ifaddr *ifa6;
1726         struct ifaddr *ifa;
1727         struct ifnet *ifp_dep = NULL;
1728         int copied = 0, allow_deprecated = 0;
1729         u_char *cp = (u_char *)(nni6 + 1);
1730         int niflags = ni6->ni_flags;
1731         u_int32_t ltime;
1732
1733         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1734                 return (0);     /* needless to copy */
1735
1736         IFNET_RLOCK();
1737   again:
1738
1739         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1740                 for (ifa = ifp->if_addrlist.tqh_first; ifa;
1741                      ifa = ifa->ifa_list.tqe_next) {
1742                         if (ifa->ifa_addr->sa_family != AF_INET6)
1743                                 continue;
1744                         ifa6 = (struct in6_ifaddr *)ifa;
1745
1746                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1747                             allow_deprecated == 0) {
1748                                 /*
1749                                  * prefererred address should be put before
1750                                  * deprecated addresses.
1751                                  */
1752
1753                                 /* record the interface for later search */
1754                                 if (ifp_dep == NULL)
1755                                         ifp_dep = ifp;
1756
1757                                 continue;
1758                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1759                             allow_deprecated != 0)
1760                                 continue; /* we now collect deprecated addrs */
1761
1762                         /* What do we have to do about ::1? */
1763                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1764                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1765                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1766                                         continue;
1767                                 break;
1768                         case IPV6_ADDR_SCOPE_SITELOCAL:
1769                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1770                                         continue;
1771                                 break;
1772                         case IPV6_ADDR_SCOPE_GLOBAL:
1773                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1774                                         continue;
1775                                 break;
1776                         default:
1777                                 continue;
1778                         }
1779
1780                         /*
1781                          * check if anycast is okay.
1782                          * XXX: just experimental.  not in the spec.
1783                          */
1784                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1785                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1786                                 continue;
1787                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1788                             (icmp6_nodeinfo & 4) == 0) {
1789                                 continue;
1790                         }
1791
1792                         /* now we can copy the address */
1793                         if (resid < sizeof(struct in6_addr) +
1794                             sizeof(u_int32_t)) {
1795                                 /*
1796                                  * We give up much more copy.
1797                                  * Set the truncate flag and return.
1798                                  */
1799                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1800                                 IFNET_RUNLOCK();
1801                                 return (copied);
1802                         }
1803
1804                         /*
1805                          * Set the TTL of the address.
1806                          * The TTL value should be one of the following
1807                          * according to the specification:
1808                          *
1809                          * 1. The remaining lifetime of a DHCP lease on the
1810                          *    address, or
1811                          * 2. The remaining Valid Lifetime of a prefix from
1812                          *    which the address was derived through Stateless
1813                          *    Autoconfiguration.
1814                          *
1815                          * Note that we currently do not support stateful
1816                          * address configuration by DHCPv6, so the former
1817                          * case can't happen.
1818                          */
1819                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1820                                 ltime = ND6_INFINITE_LIFETIME;
1821                         else {
1822                                 if (ifa6->ia6_lifetime.ia6t_expire >
1823                                     time_second)
1824                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1825                                 else
1826                                         ltime = 0;
1827                         }
1828
1829                         bcopy(&ltime, cp, sizeof(u_int32_t));
1830                         cp += sizeof(u_int32_t);
1831
1832                         /* copy the address itself */
1833                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1834                             sizeof(struct in6_addr));
1835                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1836                         cp += sizeof(struct in6_addr);
1837
1838                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1839                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1840                 }
1841                 if (ifp0)       /* we need search only on the specified IF */
1842                         break;
1843         }
1844
1845         if (allow_deprecated == 0 && ifp_dep != NULL) {
1846                 ifp = ifp_dep;
1847                 allow_deprecated = 1;
1848
1849                 goto again;
1850         }
1851
1852         IFNET_RUNLOCK();
1853
1854         return (copied);
1855 }
1856
1857 /*
1858  * XXX almost dup'ed code with rip6_input.
1859  */
1860 static int
1861 icmp6_rip6_input(mp, off)
1862         struct  mbuf **mp;
1863         int     off;
1864 {
1865         struct mbuf *m = *mp;
1866         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1867         struct in6pcb *in6p;
1868         struct in6pcb *last = NULL;
1869         struct sockaddr_in6 fromsa;
1870         struct icmp6_hdr *icmp6;
1871         struct mbuf *opts = NULL;
1872
1873 #ifndef PULLDOWN_TEST
1874         /* this is assumed to be safe. */
1875         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1876 #else
1877         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1878         if (icmp6 == NULL) {
1879                 /* m is already reclaimed */
1880                 return (IPPROTO_DONE);
1881         }
1882 #endif
1883
1884         /*
1885          * XXX: the address may have embedded scope zone ID, which should be
1886          * hidden from applications.
1887          */
1888         bzero(&fromsa, sizeof(fromsa));
1889         fromsa.sin6_family = AF_INET6;
1890         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1891         fromsa.sin6_addr = ip6->ip6_src;
1892         if (sa6_recoverscope(&fromsa)) {
1893                 m_freem(m);
1894                 return (IPPROTO_DONE);
1895         }
1896
1897         INP_INFO_RLOCK(&ripcbinfo);
1898         LIST_FOREACH(in6p, &ripcb, inp_list) {
1899                 INP_LOCK(in6p);
1900                 if ((in6p->inp_vflag & INP_IPV6) == 0) {
1901         docontinue:
1902                         INP_UNLOCK(in6p);
1903                         continue;
1904                 }
1905                 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1906                         goto docontinue;
1907                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1908                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1909                         goto docontinue;
1910                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1911                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1912                         goto docontinue;
1913                 if (in6p->in6p_icmp6filt
1914                     && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1915                                  in6p->in6p_icmp6filt))
1916                         goto docontinue;
1917                 if (last) {
1918                         struct  mbuf *n = NULL;
1919
1920                         /*
1921                          * Recent network drivers tend to allocate a single
1922                          * mbuf cluster, rather than to make a couple of
1923                          * mbufs without clusters.  Also, since the IPv6 code
1924                          * path tries to avoid m_pullup(), it is highly
1925                          * probable that we still have an mbuf cluster here
1926                          * even though the necessary length can be stored in an
1927                          * mbuf's internal buffer.
1928                          * Meanwhile, the default size of the receive socket
1929                          * buffer for raw sockets is not so large.  This means
1930                          * the possibility of packet loss is relatively higher
1931                          * than before.  To avoid this scenario, we copy the
1932                          * received data to a separate mbuf that does not use
1933                          * a cluster, if possible.
1934                          * XXX: it is better to copy the data after stripping
1935                          * intermediate headers.
1936                          */
1937                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1938                             m->m_len <= MHLEN) {
1939                                 MGET(n, M_DONTWAIT, m->m_type);
1940                                 if (n != NULL) {
1941                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1942                                                 bcopy(m->m_data, n->m_data,
1943                                                       m->m_len);
1944                                                 n->m_len = m->m_len;
1945                                         } else {
1946                                                 m_free(n);
1947                                                 n = NULL;
1948                                         }
1949                                 }
1950                         }
1951                         if (n != NULL ||
1952                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1953                                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1954                                         ip6_savecontrol(last, n, &opts);
1955                                 /* strip intermediate headers */
1956                                 m_adj(n, off);
1957                                 if (sbappendaddr(&last->in6p_socket->so_rcv,
1958                                     (struct sockaddr *)&fromsa, n, opts)
1959                                     == 0) {
1960                                         /* should notify about lost packet */
1961                                         m_freem(n);
1962                                         if (opts) {
1963                                                 m_freem(opts);
1964                                         }
1965                                 } else
1966                                         sorwakeup(last->in6p_socket);
1967                                 opts = NULL;
1968                         }
1969                         INP_UNLOCK(last);
1970                 }
1971                 last = in6p;
1972         }
1973         if (last) {
1974                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1975                         ip6_savecontrol(last, m, &opts);
1976                 /* strip intermediate headers */
1977                 m_adj(m, off);
1978
1979                 /* avoid using mbuf clusters if possible (see above) */
1980                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1981                     m->m_len <= MHLEN) {
1982                         struct mbuf *n;
1983
1984                         MGET(n, M_DONTWAIT, m->m_type);
1985                         if (n != NULL) {
1986                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1987                                         bcopy(m->m_data, n->m_data, m->m_len);
1988                                         n->m_len = m->m_len;
1989
1990                                         m_freem(m);
1991                                         m = n;
1992                                 } else {
1993                                         m_freem(n);
1994                                         n = NULL;
1995                                 }
1996                         }
1997                 }
1998                 if (sbappendaddr(&last->in6p_socket->so_rcv,
1999                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2000                         m_freem(m);
2001                         if (opts)
2002                                 m_freem(opts);
2003                 } else
2004                         sorwakeup(last->in6p_socket);
2005                 INP_UNLOCK(last);
2006         } else {
2007                 m_freem(m);
2008                 ip6stat.ip6s_delivered--;
2009         }
2010         INP_INFO_RUNLOCK(&ripcbinfo);
2011         return IPPROTO_DONE;
2012 }
2013
2014 /*
2015  * Reflect the ip6 packet back to the source.
2016  * OFF points to the icmp6 header, counted from the top of the mbuf.
2017  */
2018 void
2019 icmp6_reflect(m, off)
2020         struct  mbuf *m;
2021         size_t off;
2022 {
2023         struct ip6_hdr *ip6;
2024         struct icmp6_hdr *icmp6;
2025         struct in6_ifaddr *ia;
2026         int plen;
2027         int type, code;
2028         struct ifnet *outif = NULL;
2029         struct in6_addr origdst, *src = NULL;
2030
2031         /* too short to reflect */
2032         if (off < sizeof(struct ip6_hdr)) {
2033                 nd6log((LOG_DEBUG,
2034                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2035                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2036                     __FILE__, __LINE__));
2037                 goto bad;
2038         }
2039
2040         /*
2041          * If there are extra headers between IPv6 and ICMPv6, strip
2042          * off that header first.
2043          */
2044 #ifdef DIAGNOSTIC
2045         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2046                 panic("assumption failed in icmp6_reflect");
2047 #endif
2048         if (off > sizeof(struct ip6_hdr)) {
2049                 size_t l;
2050                 struct ip6_hdr nip6;
2051
2052                 l = off - sizeof(struct ip6_hdr);
2053                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2054                 m_adj(m, l);
2055                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2056                 if (m->m_len < l) {
2057                         if ((m = m_pullup(m, l)) == NULL)
2058                                 return;
2059                 }
2060                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2061         } else /* off == sizeof(struct ip6_hdr) */ {
2062                 size_t l;
2063                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2064                 if (m->m_len < l) {
2065                         if ((m = m_pullup(m, l)) == NULL)
2066                                 return;
2067                 }
2068         }
2069         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2070         ip6 = mtod(m, struct ip6_hdr *);
2071         ip6->ip6_nxt = IPPROTO_ICMPV6;
2072         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2073         type = icmp6->icmp6_type; /* keep type for statistics */
2074         code = icmp6->icmp6_code; /* ditto. */
2075
2076         origdst = ip6->ip6_dst;
2077         /*
2078          * ip6_input() drops a packet if its src is multicast.
2079          * So, the src is never multicast.
2080          */
2081         ip6->ip6_dst = ip6->ip6_src;
2082
2083         /*
2084          * If the incoming packet was addressed directly to us (i.e. unicast),
2085          * use dst as the src for the reply.
2086          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2087          * (for example) when we encounter an error while forwarding procedure
2088          * destined to a duplicated address of ours.
2089          * Note that ip6_getdstifaddr() may fail if we are in an error handling
2090          * procedure of an outgoing packet of our own, in which case we need
2091          * to search in the ifaddr list.
2092          */
2093         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2094                 if ((ia = ip6_getdstifaddr(m))) {
2095                         if (!(ia->ia6_flags &
2096                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2097                                 src = &ia->ia_addr.sin6_addr;
2098                 } else {
2099                         struct sockaddr_in6 d;
2100
2101                         bzero(&d, sizeof(d));
2102                         d.sin6_family = AF_INET6;
2103                         d.sin6_len = sizeof(d);
2104                         d.sin6_addr = origdst;
2105                         ia = (struct in6_ifaddr *)
2106                             ifa_ifwithaddr((struct sockaddr *)&d);
2107                         if (ia &&
2108                             !(ia->ia6_flags &
2109                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2110                                 src = &ia->ia_addr.sin6_addr;
2111                         }
2112                 }
2113         }
2114
2115         if (src == NULL) {
2116                 int e;
2117                 struct sockaddr_in6 sin6;
2118                 struct route_in6 ro;
2119
2120                 /*
2121                  * This case matches to multicasts, our anycast, or unicasts
2122                  * that we do not own.  Select a source address based on the
2123                  * source address of the erroneous packet.
2124                  */
2125                 bzero(&sin6, sizeof(sin6));
2126                 sin6.sin6_family = AF_INET6;
2127                 sin6.sin6_len = sizeof(sin6);
2128                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2129
2130                 bzero(&ro, sizeof(ro));
2131                 src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e);
2132                 if (ro.ro_rt)
2133                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2134                 if (src == NULL) {
2135                         nd6log((LOG_DEBUG,
2136                             "icmp6_reflect: source can't be determined: "
2137                             "dst=%s, error=%d\n",
2138                             ip6_sprintf(&sin6.sin6_addr), e));
2139                         goto bad;
2140                 }
2141         }
2142
2143         ip6->ip6_src = *src;
2144         ip6->ip6_flow = 0;
2145         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2146         ip6->ip6_vfc |= IPV6_VERSION;
2147         ip6->ip6_nxt = IPPROTO_ICMPV6;
2148         if (outif)
2149                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2150         else if (m->m_pkthdr.rcvif) {
2151                 /* XXX: This may not be the outgoing interface */
2152                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2153         } else
2154                 ip6->ip6_hlim = ip6_defhlim;
2155
2156         icmp6->icmp6_cksum = 0;
2157         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2158             sizeof(struct ip6_hdr), plen);
2159
2160         /*
2161          * XXX option handling
2162          */
2163
2164         m->m_flags &= ~(M_BCAST|M_MCAST);
2165
2166         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2167         if (outif)
2168                 icmp6_ifoutstat_inc(outif, type, code);
2169
2170         return;
2171
2172  bad:
2173         m_freem(m);
2174         return;
2175 }
2176
2177 void
2178 icmp6_fasttimo()
2179 {
2180
2181         return;
2182 }
2183
2184 static const char *
2185 icmp6_redirect_diag(src6, dst6, tgt6)
2186         struct in6_addr *src6;
2187         struct in6_addr *dst6;
2188         struct in6_addr *tgt6;
2189 {
2190         static char buf[1024];
2191         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2192             ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2193         return buf;
2194 }
2195
2196 void
2197 icmp6_redirect_input(m, off)
2198         struct mbuf *m;
2199         int off;
2200 {
2201         struct ifnet *ifp = m->m_pkthdr.rcvif;
2202         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2203         struct nd_redirect *nd_rd;
2204         int icmp6len = ntohs(ip6->ip6_plen);
2205         char *lladdr = NULL;
2206         int lladdrlen = 0;
2207         u_char *redirhdr = NULL;
2208         int redirhdrlen = 0;
2209         struct rtentry *rt = NULL;
2210         int is_router;
2211         int is_onlink;
2212         struct in6_addr src6 = ip6->ip6_src;
2213         struct in6_addr redtgt6;
2214         struct in6_addr reddst6;
2215         union nd_opts ndopts;
2216
2217         if (!m || !ifp)
2218                 return;
2219
2220         /* XXX if we are router, we don't update route by icmp6 redirect */
2221         if (ip6_forwarding)
2222                 goto freeit;
2223         if (!icmp6_rediraccept)
2224                 goto freeit;
2225
2226 #ifndef PULLDOWN_TEST
2227         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2228         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2229 #else
2230         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2231         if (nd_rd == NULL) {
2232                 icmp6stat.icp6s_tooshort++;
2233                 return;
2234         }
2235 #endif
2236         redtgt6 = nd_rd->nd_rd_target;
2237         reddst6 = nd_rd->nd_rd_dst;
2238
2239         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2240             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2241                 goto freeit;
2242         }
2243
2244         /* validation */
2245         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2246                 nd6log((LOG_ERR,
2247                     "ICMP6 redirect sent from %s rejected; "
2248                     "must be from linklocal\n",
2249                     ip6_sprintf(&src6)));
2250                 goto bad;
2251         }
2252         if (ip6->ip6_hlim != 255) {
2253                 nd6log((LOG_ERR,
2254                     "ICMP6 redirect sent from %s rejected; "
2255                     "hlim=%d (must be 255)\n",
2256                     ip6_sprintf(&src6), ip6->ip6_hlim));
2257                 goto bad;
2258         }
2259     {
2260         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2261         struct sockaddr_in6 sin6;
2262         struct in6_addr *gw6;
2263
2264         bzero(&sin6, sizeof(sin6));
2265         sin6.sin6_family = AF_INET6;
2266         sin6.sin6_len = sizeof(struct sockaddr_in6);
2267         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2268         rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2269         if (rt) {
2270                 if (rt->rt_gateway == NULL ||
2271                     rt->rt_gateway->sa_family != AF_INET6) {
2272                         nd6log((LOG_ERR,
2273                             "ICMP6 redirect rejected; no route "
2274                             "with inet6 gateway found for redirect dst: %s\n",
2275                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2276                         RTFREE_LOCKED(rt);
2277                         goto bad;
2278                 }
2279
2280                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2281                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2282                         nd6log((LOG_ERR,
2283                             "ICMP6 redirect rejected; "
2284                             "not equal to gw-for-src=%s (must be same): "
2285                             "%s\n",
2286                             ip6_sprintf(gw6),
2287                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2288                         RTFREE_LOCKED(rt);
2289                         goto bad;
2290                 }
2291         } else {
2292                 nd6log((LOG_ERR,
2293                     "ICMP6 redirect rejected; "
2294                     "no route found for redirect dst: %s\n",
2295                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2296                 goto bad;
2297         }
2298         RTFREE_LOCKED(rt);
2299         rt = NULL;
2300     }
2301         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2302                 nd6log((LOG_ERR,
2303                     "ICMP6 redirect rejected; "
2304                     "redirect dst must be unicast: %s\n",
2305                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2306                 goto bad;
2307         }
2308
2309         is_router = is_onlink = 0;
2310         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2311                 is_router = 1;  /* router case */
2312         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2313                 is_onlink = 1;  /* on-link destination case */
2314         if (!is_router && !is_onlink) {
2315                 nd6log((LOG_ERR,
2316                     "ICMP6 redirect rejected; "
2317                     "neither router case nor onlink case: %s\n",
2318                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2319                 goto bad;
2320         }
2321         /* validation passed */
2322
2323         icmp6len -= sizeof(*nd_rd);
2324         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2325         if (nd6_options(&ndopts) < 0) {
2326                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2327                     "invalid ND option, rejected: %s\n",
2328                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2329                 /* nd6_options have incremented stats */
2330                 goto freeit;
2331         }
2332
2333         if (ndopts.nd_opts_tgt_lladdr) {
2334                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2335                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2336         }
2337
2338         if (ndopts.nd_opts_rh) {
2339                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2340                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2341         }
2342
2343         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2344                 nd6log((LOG_INFO,
2345                     "icmp6_redirect_input: lladdrlen mismatch for %s "
2346                     "(if %d, icmp6 packet %d): %s\n",
2347                     ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2348                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2349                 goto bad;
2350         }
2351
2352         /* RFC 2461 8.3 */
2353         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2354             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2355
2356         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2357                 /* perform rtredirect */
2358                 struct sockaddr_in6 sdst;
2359                 struct sockaddr_in6 sgw;
2360                 struct sockaddr_in6 ssrc;
2361
2362                 bzero(&sdst, sizeof(sdst));
2363                 bzero(&sgw, sizeof(sgw));
2364                 bzero(&ssrc, sizeof(ssrc));
2365                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2366                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2367                         sizeof(struct sockaddr_in6);
2368                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2369                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2370                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2371                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2372                     (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2373                     (struct sockaddr *)&ssrc);
2374         }
2375         /* finally update cached route in each socket via pfctlinput */
2376     {
2377         struct sockaddr_in6 sdst;
2378
2379         bzero(&sdst, sizeof(sdst));
2380         sdst.sin6_family = AF_INET6;
2381         sdst.sin6_len = sizeof(struct sockaddr_in6);
2382         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2383         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2384 #if defined(IPSEC) || defined(FAST_IPSEC)
2385         key_sa_routechange((struct sockaddr *)&sdst);
2386 #endif
2387     }
2388
2389  freeit:
2390         m_freem(m);
2391         return;
2392
2393  bad:
2394         icmp6stat.icp6s_badredirect++;
2395         m_freem(m);
2396 }
2397
2398 void
2399 icmp6_redirect_output(m0, rt)
2400         struct mbuf *m0;
2401         struct rtentry *rt;
2402 {
2403         struct ifnet *ifp;      /* my outgoing interface */
2404         struct in6_addr *ifp_ll6;
2405         struct in6_addr *router_ll6;
2406         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2407         struct mbuf *m = NULL;  /* newly allocated one */
2408         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2409         struct nd_redirect *nd_rd;
2410         size_t maxlen;
2411         u_char *p;
2412         struct ifnet *outif = NULL;
2413         struct sockaddr_in6 src_sa;
2414
2415         icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2416
2417         /* if we are not router, we don't send icmp6 redirect */
2418         if (!ip6_forwarding)
2419                 goto fail;
2420
2421         /* sanity check */
2422         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2423                 goto fail;
2424
2425         /*
2426          * Address check:
2427          *  the source address must identify a neighbor, and
2428          *  the destination address must not be a multicast address
2429          *  [RFC 2461, sec 8.2]
2430          */
2431         sip6 = mtod(m0, struct ip6_hdr *);
2432         bzero(&src_sa, sizeof(src_sa));
2433         src_sa.sin6_family = AF_INET6;
2434         src_sa.sin6_len = sizeof(src_sa);
2435         src_sa.sin6_addr = sip6->ip6_src;
2436         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2437                 goto fail;
2438         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2439                 goto fail;      /* what should we do here? */
2440
2441         /* rate limit */
2442         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2443                 goto fail;
2444
2445         /*
2446          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2447          * we almost always ask for an mbuf cluster for simplicity.
2448          * (MHLEN < IPV6_MMTU is almost always true)
2449          */
2450 #if IPV6_MMTU >= MCLBYTES
2451 # error assumption failed about IPV6_MMTU and MCLBYTES
2452 #endif
2453         MGETHDR(m, M_DONTWAIT, MT_HEADER);
2454         if (m && IPV6_MMTU >= MHLEN)
2455                 MCLGET(m, M_DONTWAIT);
2456         if (!m)
2457                 goto fail;
2458         m->m_pkthdr.rcvif = NULL;
2459         m->m_len = 0;
2460         maxlen = M_TRAILINGSPACE(m);
2461         maxlen = min(IPV6_MMTU, maxlen);
2462         /* just for safety */
2463         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2464             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2465                 goto fail;
2466         }
2467
2468         {
2469                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2470                 struct in6_ifaddr *ia;
2471                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2472                                                  IN6_IFF_NOTREADY|
2473                                                  IN6_IFF_ANYCAST)) == NULL)
2474                         goto fail;
2475                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2476         }
2477
2478         /* get ip6 linklocal address for the router. */
2479         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2480                 struct sockaddr_in6 *sin6;
2481                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2482                 router_ll6 = &sin6->sin6_addr;
2483                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2484                         router_ll6 = (struct in6_addr *)NULL;
2485         } else
2486                 router_ll6 = (struct in6_addr *)NULL;
2487
2488         /* ip6 */
2489         ip6 = mtod(m, struct ip6_hdr *);
2490         ip6->ip6_flow = 0;
2491         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2492         ip6->ip6_vfc |= IPV6_VERSION;
2493         /* ip6->ip6_plen will be set later */
2494         ip6->ip6_nxt = IPPROTO_ICMPV6;
2495         ip6->ip6_hlim = 255;
2496         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2497         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2498         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2499
2500         /* ND Redirect */
2501         nd_rd = (struct nd_redirect *)(ip6 + 1);
2502         nd_rd->nd_rd_type = ND_REDIRECT;
2503         nd_rd->nd_rd_code = 0;
2504         nd_rd->nd_rd_reserved = 0;
2505         if (rt->rt_flags & RTF_GATEWAY) {
2506                 /*
2507                  * nd_rd->nd_rd_target must be a link-local address in
2508                  * better router cases.
2509                  */
2510                 if (!router_ll6)
2511                         goto fail;
2512                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2513                     sizeof(nd_rd->nd_rd_target));
2514                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2515                     sizeof(nd_rd->nd_rd_dst));
2516         } else {
2517                 /* make sure redtgt == reddst */
2518                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2519                     sizeof(nd_rd->nd_rd_target));
2520                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2521                     sizeof(nd_rd->nd_rd_dst));
2522         }
2523
2524         p = (u_char *)(nd_rd + 1);
2525
2526         if (!router_ll6)
2527                 goto nolladdropt;
2528
2529         {
2530                 /* target lladdr option */
2531                 struct rtentry *rt_router = NULL;
2532                 int len;
2533                 struct sockaddr_dl *sdl;
2534                 struct nd_opt_hdr *nd_opt;
2535                 char *lladdr;
2536
2537                 rt_router = nd6_lookup(router_ll6, 0, ifp);
2538                 if (!rt_router)
2539                         goto nolladdropt;
2540                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2541                 len = (len + 7) & ~7;   /* round by 8 */
2542                 /* safety check */
2543                 if (len + (p - (u_char *)ip6) > maxlen)
2544                         goto nolladdropt;
2545                 if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2546                     (rt_router->rt_flags & RTF_LLINFO) &&
2547                     (rt_router->rt_gateway->sa_family == AF_LINK) &&
2548                     (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2549                     sdl->sdl_alen) {
2550                         nd_opt = (struct nd_opt_hdr *)p;
2551                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2552                         nd_opt->nd_opt_len = len >> 3;
2553                         lladdr = (char *)(nd_opt + 1);
2554                         bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2555                         p += len;
2556                 }
2557         }
2558 nolladdropt:;
2559
2560         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2561
2562         /* just to be safe */
2563 #ifdef M_DECRYPTED      /*not openbsd*/
2564         if (m0->m_flags & M_DECRYPTED)
2565                 goto noredhdropt;
2566 #endif
2567         if (p - (u_char *)ip6 > maxlen)
2568                 goto noredhdropt;
2569
2570         {
2571                 /* redirected header option */
2572                 int len;
2573                 struct nd_opt_rd_hdr *nd_opt_rh;
2574
2575                 /*
2576                  * compute the maximum size for icmp6 redirect header option.
2577                  * XXX room for auth header?
2578                  */
2579                 len = maxlen - (p - (u_char *)ip6);
2580                 len &= ~7;
2581
2582                 /* This is just for simplicity. */
2583                 if (m0->m_pkthdr.len != m0->m_len) {
2584                         if (m0->m_next) {
2585                                 m_freem(m0->m_next);
2586                                 m0->m_next = NULL;
2587                         }
2588                         m0->m_pkthdr.len = m0->m_len;
2589                 }
2590
2591                 /*
2592                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2593                  * about padding/truncate rule for the original IP packet.
2594                  * From the discussion on IPv6imp in Feb 1999,
2595                  * the consensus was:
2596                  * - "attach as much as possible" is the goal
2597                  * - pad if not aligned (original size can be guessed by
2598                  *   original ip6 header)
2599                  * Following code adds the padding if it is simple enough,
2600                  * and truncates if not.
2601                  */
2602                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2603                         panic("assumption failed in %s:%d", __FILE__,
2604                             __LINE__);
2605
2606                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2607                         /* not enough room, truncate */
2608                         m0->m_pkthdr.len = m0->m_len = len -
2609                             sizeof(*nd_opt_rh);
2610                 } else {
2611                         /* enough room, pad or truncate */
2612                         size_t extra;
2613
2614                         extra = m0->m_pkthdr.len % 8;
2615                         if (extra) {
2616                                 /* pad if easy enough, truncate if not */
2617                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2618                                         /* pad */
2619                                         m0->m_len += (8 - extra);
2620                                         m0->m_pkthdr.len += (8 - extra);
2621                                 } else {
2622                                         /* truncate */
2623                                         m0->m_pkthdr.len -= extra;
2624                                         m0->m_len -= extra;
2625                                 }
2626                         }
2627                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2628                         m0->m_pkthdr.len = m0->m_len = len -
2629                             sizeof(*nd_opt_rh);
2630                 }
2631
2632                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2633                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2634                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2635                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2636                 p += sizeof(*nd_opt_rh);
2637                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2638
2639                 /* connect m0 to m */
2640                 m_tag_delete_chain(m0, NULL);
2641                 m0->m_flags &= ~M_PKTHDR;
2642                 m->m_next = m0;
2643                 m->m_pkthdr.len = m->m_len + m0->m_len;
2644                 m0 = NULL;
2645         }
2646 noredhdropt:;
2647         if (m0) {
2648                 m_freem(m0);
2649                 m0 = NULL;
2650         }
2651
2652         /* XXX: clear embedded link IDs in the inner header */
2653         in6_clearscope(&sip6->ip6_src);
2654         in6_clearscope(&sip6->ip6_dst);
2655         in6_clearscope(&nd_rd->nd_rd_target);
2656         in6_clearscope(&nd_rd->nd_rd_dst);
2657
2658         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2659
2660         nd_rd->nd_rd_cksum = 0;
2661         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2662             sizeof(*ip6), ntohs(ip6->ip6_plen));
2663
2664         /* send the packet to outside... */
2665         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2666         if (outif) {
2667                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2668                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2669         }
2670         icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2671
2672         return;
2673
2674 fail:
2675         if (m)
2676                 m_freem(m);
2677         if (m0)
2678                 m_freem(m0);
2679 }
2680
2681 /*
2682  * ICMPv6 socket option processing.
2683  */
2684 int
2685 icmp6_ctloutput(so, sopt)
2686         struct socket *so;
2687         struct sockopt *sopt;
2688 {
2689         int error = 0;
2690         int optlen;
2691         struct inpcb *inp = sotoinpcb(so);
2692         int level, op, optname;
2693
2694         if (sopt) {
2695                 level = sopt->sopt_level;
2696                 op = sopt->sopt_dir;
2697                 optname = sopt->sopt_name;
2698                 optlen = sopt->sopt_valsize;
2699         } else
2700                 level = op = optname = optlen = 0;
2701
2702         if (level != IPPROTO_ICMPV6) {
2703                 return EINVAL;
2704         }
2705
2706         switch (op) {
2707         case PRCO_SETOPT:
2708                 switch (optname) {
2709                 case ICMP6_FILTER:
2710                     {
2711                         struct icmp6_filter *p;
2712
2713                         if (optlen != sizeof(*p)) {
2714                                 error = EMSGSIZE;
2715                                 break;
2716                         }
2717                         if (inp->in6p_icmp6filt == NULL) {
2718                                 error = EINVAL;
2719                                 break;
2720                         }
2721                         error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
2722                                 optlen);
2723                         break;
2724                     }
2725
2726                 default:
2727                         error = ENOPROTOOPT;
2728                         break;
2729                 }
2730                 break;
2731
2732         case PRCO_GETOPT:
2733                 switch (optname) {
2734                 case ICMP6_FILTER:
2735                     {
2736                         if (inp->in6p_icmp6filt == NULL) {
2737                                 error = EINVAL;
2738                                 break;
2739                         }
2740                         error = sooptcopyout(sopt, inp->in6p_icmp6filt,
2741                                 sizeof(struct icmp6_filter));
2742                         break;
2743                     }
2744
2745                 default:
2746                         error = ENOPROTOOPT;
2747                         break;
2748                 }
2749                 break;
2750         }
2751
2752         return (error);
2753 }
2754
2755 /*
2756  * Perform rate limit check.
2757  * Returns 0 if it is okay to send the icmp6 packet.
2758  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2759  * limitation.
2760  *
2761  * XXX per-destination/type check necessary?
2762  */
2763 static int
2764 icmp6_ratelimit(dst, type, code)
2765         const struct in6_addr *dst;     /* not used at this moment */
2766         const int type;                 /* not used at this moment */
2767         const int code;                 /* not used at this moment */
2768 {
2769         int ret;
2770
2771         ret = 0;        /* okay to send */
2772
2773         /* PPS limit */
2774         if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2775             icmp6errppslim)) {
2776                 /* The packet is subject to rate limit */
2777                 ret++;
2778         }
2779
2780         return ret;
2781 }