sys/netinet6/icmp6.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipsec.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/domain.h>
  72 #include <sys/jail.h>
  73 #include <sys/kernel.h>
  74 #include <sys/lock.h>
  75 #include <sys/malloc.h>
  76 #include <sys/mbuf.h>
  77 #include <sys/proc.h>
  78 #include <sys/protosw.h>
  79 #include <sys/signalvar.h>
  80 #include <sys/socket.h>
  81 #include <sys/socketvar.h>
  82 #include <sys/sx.h>
  83 #include <sys/syslog.h>
  84 #include <sys/systm.h>
  85 #include <sys/time.h>
  86
  87 #include <net/if.h>
  88 #include <net/if_dl.h>
  89 #include <net/if_llatbl.h>
  90 #include <net/if_types.h>
  91 #include <net/route.h>
  92 #include <net/vnet.h>
  93
  94 #include <netinet/in.h>
  95 #include <netinet/in_pcb.h>
  96 #include <netinet/in_var.h>
  97 #include <netinet/ip6.h>
  98 #include <netinet/icmp6.h>
  99 #include <netinet/tcp_var.h>
 100
 101 #include <netinet6/in6_ifattach.h>
 102 #include <netinet6/in6_pcb.h>
 103 #include <netinet6/ip6protosw.h>
 104 #include <netinet6/ip6_var.h>
 105 #include <netinet6/scope6_var.h>
 106 #include <netinet6/mld6_var.h>
 107 #include <netinet6/nd6.h>
 108
 109 #ifdef IPSEC
 110 #include <netipsec/ipsec.h>
 111 #include <netipsec/key.h>
 112 #endif
 113
 114 extern struct domain inet6domain;
 115
 116 VNET_DEFINE(struct icmp6stat, icmp6stat);
 117
 118 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 119 VNET_DECLARE(struct inpcbhead, ripcb);
 120 VNET_DECLARE(int, icmp6errppslim);
 121 static VNET_DEFINE(int, icmp6errpps_count) = 0;
 122 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 123 VNET_DECLARE(int, icmp6_nodeinfo);
 124
 125 #define V_ripcbinfo                     VNET(ripcbinfo)
 126 #define V_ripcb                         VNET(ripcb)
 127 #define V_icmp6errppslim                VNET(icmp6errppslim)
 128 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 129 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 130 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 131
 132 static void icmp6_errcount(struct icmp6errstat *, int, int);
 133 static int icmp6_rip6_input(struct mbuf **, int);
 134 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 135 static const char *icmp6_redirect_diag __P((struct in6_addr *,
 136         struct in6_addr *, struct in6_addr *));
 137 static struct mbuf *ni6_input(struct mbuf *, int);
 138 static struct mbuf *ni6_nametodns(const char *, int, int);
 139 static int ni6_dnsmatch(const char *, int, const char *, int);
 140 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
 141                           struct ifnet **, struct in6_addr *));
 142 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 143                                 struct ifnet *, int));
 144 static int icmp6_notify_error(struct mbuf **, int, int, int);
 145
 146 /*
 147  * Kernel module interface for updating icmp6stat.  The argument is an index
 148  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 149  * general layout of icmp6stat into the caller, it doesn't encode its
 150  * location, so that future changes to add, for example, per-CPU stats
 151  * support won't cause binary compatibility problems for kernel modules.
 152  */
 153 void
 154 kmod_icmp6stat_inc(int statnum)
 155 {
 156
 157         (*((u_quad_t *)&V_icmp6stat + statnum))++;
 158 }
 159
 160 static void
 161 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
 162 {
 163         switch (type) {
 164         case ICMP6_DST_UNREACH:
 165                 switch (code) {
 166                 case ICMP6_DST_UNREACH_NOROUTE:
 167                         stat->icp6errs_dst_unreach_noroute++;
 168                         return;
 169                 case ICMP6_DST_UNREACH_ADMIN:
 170                         stat->icp6errs_dst_unreach_admin++;
 171                         return;
 172                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 173                         stat->icp6errs_dst_unreach_beyondscope++;
 174                         return;
 175                 case ICMP6_DST_UNREACH_ADDR:
 176                         stat->icp6errs_dst_unreach_addr++;
 177                         return;
 178                 case ICMP6_DST_UNREACH_NOPORT:
 179                         stat->icp6errs_dst_unreach_noport++;
 180                         return;
 181                 }
 182                 break;
 183         case ICMP6_PACKET_TOO_BIG:
 184                 stat->icp6errs_packet_too_big++;
 185                 return;
 186         case ICMP6_TIME_EXCEEDED:
 187                 switch (code) {
 188                 case ICMP6_TIME_EXCEED_TRANSIT:
 189                         stat->icp6errs_time_exceed_transit++;
 190                         return;
 191                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 192                         stat->icp6errs_time_exceed_reassembly++;
 193                         return;
 194                 }
 195                 break;
 196         case ICMP6_PARAM_PROB:
 197                 switch (code) {
 198                 case ICMP6_PARAMPROB_HEADER:
 199                         stat->icp6errs_paramprob_header++;
 200                         return;
 201                 case ICMP6_PARAMPROB_NEXTHEADER:
 202                         stat->icp6errs_paramprob_nextheader++;
 203                         return;
 204                 case ICMP6_PARAMPROB_OPTION:
 205                         stat->icp6errs_paramprob_option++;
 206                         return;
 207                 }
 208                 break;
 209         case ND_REDIRECT:
 210                 stat->icp6errs_redirect++;
 211                 return;
 212         }
 213         stat->icp6errs_unknown++;
 214 }
 215
 216 /*
 217  * A wrapper function for icmp6_error() necessary when the erroneous packet
 218  * may not contain enough scope zone information.
 219  */
 220 void
 221 icmp6_error2(struct mbuf *m, int type, int code, int param,
 222     struct ifnet *ifp)
 223 {
 224         struct ip6_hdr *ip6;
 225
 226         if (ifp == NULL)
 227                 return;
 228
 229 #ifndef PULLDOWN_TEST
 230         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 231 #else
 232         if (m->m_len < sizeof(struct ip6_hdr)) {
 233                 m = m_pullup(m, sizeof(struct ip6_hdr));
 234                 if (m == NULL)
 235                         return;
 236         }
 237 #endif
 238
 239         ip6 = mtod(m, struct ip6_hdr *);
 240
 241         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 242                 return;
 243         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 244                 return;
 245
 246         icmp6_error(m, type, code, param);
 247 }
 248
 249 /*
 250  * Generate an error packet of type error in response to bad IP6 packet.
 251  */
 252 void
 253 icmp6_error(struct mbuf *m, int type, int code, int param)
 254 {
 255         struct ip6_hdr *oip6, *nip6;
 256         struct icmp6_hdr *icmp6;
 257         u_int preplen;
 258         int off;
 259         int nxt;
 260
 261         ICMP6STAT_INC(icp6s_error);
 262
 263         /* count per-type-code statistics */
 264         icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code);
 265
 266 #ifdef M_DECRYPTED      /*not openbsd*/
 267         if (m->m_flags & M_DECRYPTED) {
 268                 ICMP6STAT_INC(icp6s_canterror);
 269                 goto freeit;
 270         }
 271 #endif
 272
 273 #ifndef PULLDOWN_TEST
 274         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 275 #else
 276         if (m->m_len < sizeof(struct ip6_hdr)) {
 277                 m = m_pullup(m, sizeof(struct ip6_hdr));
 278                 if (m == NULL)
 279                         return;
 280         }
 281 #endif
 282         oip6 = mtod(m, struct ip6_hdr *);
 283
 284         /*
 285          * If the destination address of the erroneous packet is a multicast
 286          * address, or the packet was sent using link-layer multicast,
 287          * we should basically suppress sending an error (RFC 2463, Section
 288          * 2.4).
 289          * We have two exceptions (the item e.2 in that section):
 290          * - the Packet Too Big message can be sent for path MTU discovery.
 291          * - the Parameter Problem Message that can be allowed an icmp6 error
 292          *   in the option type field.  This check has been done in
 293          *   ip6_unknown_opt(), so we can just check the type and code.
 294          */
 295         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 296              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 297             (type != ICMP6_PACKET_TOO_BIG &&
 298              (type != ICMP6_PARAM_PROB ||
 299               code != ICMP6_PARAMPROB_OPTION)))
 300                 goto freeit;
 301
 302         /*
 303          * RFC 2463, 2.4 (e.5): source address check.
 304          * XXX: the case of anycast source?
 305          */
 306         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 307             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 308                 goto freeit;
 309
 310         /*
 311          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 312          * don't do it.
 313          */
 314         nxt = -1;
 315         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 316         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 317                 struct icmp6_hdr *icp;
 318
 319 #ifndef PULLDOWN_TEST
 320                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 321                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 322 #else
 323                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 324                         sizeof(*icp));
 325                 if (icp == NULL) {
 326                         ICMP6STAT_INC(icp6s_tooshort);
 327                         return;
 328                 }
 329 #endif
 330                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 331                     icp->icmp6_type == ND_REDIRECT) {
 332                         /*
 333                          * ICMPv6 error
 334                          * Special case: for redirect (which is
 335                          * informational) we must not send icmp6 error.
 336                          */
 337                         ICMP6STAT_INC(icp6s_canterror);
 338                         goto freeit;
 339                 } else {
 340                         /* ICMPv6 informational - send the error */
 341                 }
 342         } else {
 343                 /* non-ICMPv6 - send the error */
 344         }
 345
 346         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 347
 348         /* Finally, do rate limitation check. */
 349         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 350                 ICMP6STAT_INC(icp6s_toofreq);
 351                 goto freeit;
 352         }
 353
 354         /*
 355          * OK, ICMP6 can be generated.
 356          */
 357
 358         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 359                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 360
 361         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 362         M_PREPEND(m, preplen, M_DONTWAIT);
 363         if (m && m->m_len < preplen)
 364                 m = m_pullup(m, preplen);
 365         if (m == NULL) {
 366                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 367                 return;
 368         }
 369
 370         nip6 = mtod(m, struct ip6_hdr *);
 371         nip6->ip6_src  = oip6->ip6_src;
 372         nip6->ip6_dst  = oip6->ip6_dst;
 373
 374         in6_clearscope(&oip6->ip6_src);
 375         in6_clearscope(&oip6->ip6_dst);
 376
 377         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 378         icmp6->icmp6_type = type;
 379         icmp6->icmp6_code = code;
 380         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 381
 382         /*
 383          * icmp6_reflect() is designed to be in the input path.
 384          * icmp6_error() can be called from both input and output path,
 385          * and if we are in output path rcvif could contain bogus value.
 386          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 387          * information in ip header (nip6).
 388          */
 389         m->m_pkthdr.rcvif = NULL;
 390
 391         ICMP6STAT_INC(icp6s_outhist[type]);
 392         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 393
 394         return;
 395
 396   freeit:
 397         /*
 398          * If we can't tell whether or not we can generate ICMP6, free it.
 399          */
 400         m_freem(m);
 401 }
 402
 403 /*
 404  * Process a received ICMP6 message.
 405  */
 406 int
 407 icmp6_input(struct mbuf **mp, int *offp, int proto)
 408 {
 409         struct mbuf *m = *mp, *n;
 410         struct ifnet *ifp;
 411         struct ip6_hdr *ip6, *nip6;
 412         struct icmp6_hdr *icmp6, *nicmp6;
 413         int off = *offp;
 414         int icmp6len = m->m_pkthdr.len - *offp;
 415         int code, sum, noff;
 416         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 417
 418         ifp = m->m_pkthdr.rcvif;
 419
 420 #ifndef PULLDOWN_TEST
 421         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 422         /* m might change if M_LOOP.  So, call mtod after this */
 423 #endif
 424
 425         /*
 426          * Locate icmp6 structure in mbuf, and check
 427          * that not corrupted and of at least minimum length
 428          */
 429
 430         ip6 = mtod(m, struct ip6_hdr *);
 431         if (icmp6len < sizeof(struct icmp6_hdr)) {
 432                 ICMP6STAT_INC(icp6s_tooshort);
 433                 goto freeit;
 434         }
 435
 436         /*
 437          * Check multicast group membership.
 438          * Note: SSM filters are not applied for ICMPv6 traffic.
 439          */
 440         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 441                 struct in6_multi        *inm;
 442
 443                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 444                 if (inm == NULL) {
 445                         IP6STAT_INC(ip6s_notmember);
 446                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 447                         goto freeit;
 448                 }
 449         }
 450
 451         /*
 452          * calculate the checksum
 453          */
 454 #ifndef PULLDOWN_TEST
 455         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 456 #else
 457         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 458         if (icmp6 == NULL) {
 459                 ICMP6STAT_INC(icp6s_tooshort);
 460                 return IPPROTO_DONE;
 461         }
 462 #endif
 463         code = icmp6->icmp6_code;
 464
 465         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 466                 nd6log((LOG_ERR,
 467                     "ICMP6 checksum error(%d|%x) %s\n",
 468                     icmp6->icmp6_type, sum,
 469                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 470                 ICMP6STAT_INC(icp6s_checksum);
 471                 goto freeit;
 472         }
 473
 474         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 475                 /*
 476                  * Deliver very specific ICMP6 type only.
 477                  * This is important to deliver TOOBIG.  Otherwise PMTUD
 478                  * will not work.
 479                  */
 480                 switch (icmp6->icmp6_type) {
 481                 case ICMP6_DST_UNREACH:
 482                 case ICMP6_PACKET_TOO_BIG:
 483                 case ICMP6_TIME_EXCEEDED:
 484                         break;
 485                 default:
 486                         goto freeit;
 487                 }
 488         }
 489
 490         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 491         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 492         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 493                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 494
 495         switch (icmp6->icmp6_type) {
 496         case ICMP6_DST_UNREACH:
 497                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 498                 switch (code) {
 499                 case ICMP6_DST_UNREACH_NOROUTE:
 500                         code = PRC_UNREACH_NET;
 501                         break;
 502                 case ICMP6_DST_UNREACH_ADMIN:
 503                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 504                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 505                         break;
 506                 case ICMP6_DST_UNREACH_ADDR:
 507                         code = PRC_HOSTDEAD;
 508                         break;
 509                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 510                         /* I mean "source address was incorrect." */
 511                         code = PRC_PARAMPROB;
 512                         break;
 513                 case ICMP6_DST_UNREACH_NOPORT:
 514                         code = PRC_UNREACH_PORT;
 515                         break;
 516                 default:
 517                         goto badcode;
 518                 }
 519                 goto deliver;
 520                 break;
 521
 522         case ICMP6_PACKET_TOO_BIG:
 523                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 524
 525                 /* validation is made in icmp6_mtudisc_update */
 526
 527                 code = PRC_MSGSIZE;
 528
 529                 /*
 530                  * Updating the path MTU will be done after examining
 531                  * intermediate extension headers.
 532                  */
 533                 goto deliver;
 534                 break;
 535
 536         case ICMP6_TIME_EXCEEDED:
 537                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 538                 switch (code) {
 539                 case ICMP6_TIME_EXCEED_TRANSIT:
 540                         code = PRC_TIMXCEED_INTRANS;
 541                         break;
 542                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 543                         code = PRC_TIMXCEED_REASS;
 544                         break;
 545                 default:
 546                         goto badcode;
 547                 }
 548                 goto deliver;
 549                 break;
 550
 551         case ICMP6_PARAM_PROB:
 552                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 553                 switch (code) {
 554                 case ICMP6_PARAMPROB_NEXTHEADER:
 555                         code = PRC_UNREACH_PROTOCOL;
 556                         break;
 557                 case ICMP6_PARAMPROB_HEADER:
 558                 case ICMP6_PARAMPROB_OPTION:
 559                         code = PRC_PARAMPROB;
 560                         break;
 561                 default:
 562                         goto badcode;
 563                 }
 564                 goto deliver;
 565                 break;
 566
 567         case ICMP6_ECHO_REQUEST:
 568                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 569                 if (code != 0)
 570                         goto badcode;
 571                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 572                         /* Give up remote */
 573                         break;
 574                 }
 575                 if ((n->m_flags & M_EXT) != 0
 576                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 577                         struct mbuf *n0 = n;
 578                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 579                         int n0len;
 580
 581                         MGETHDR(n, M_DONTWAIT, n0->m_type);
 582                         n0len = n0->m_pkthdr.len;       /* save for use below */
 583                         if (n)
 584                                 M_MOVE_PKTHDR(n, n0);
 585                         if (n && maxlen >= MHLEN) {
 586                                 MCLGET(n, M_DONTWAIT);
 587                                 if ((n->m_flags & M_EXT) == 0) {
 588                                         m_free(n);
 589                                         n = NULL;
 590                                 }
 591                         }
 592                         if (n == NULL) {
 593                                 /* Give up remote */
 594                                 m_freem(n0);
 595                                 break;
 596                         }
 597                         /*
 598                          * Copy IPv6 and ICMPv6 only.
 599                          */
 600                         nip6 = mtod(n, struct ip6_hdr *);
 601                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 602                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 603                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 604                         noff = sizeof(struct ip6_hdr);
 605                         /* new mbuf contains only ipv6+icmpv6 headers */
 606                         n->m_len = noff + sizeof(struct icmp6_hdr);
 607                         /*
 608                          * Adjust mbuf.  ip6_plen will be adjusted in
 609                          * ip6_output().
 610                          */
 611                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 612                         /* recalculate complete packet size */
 613                         n->m_pkthdr.len = n0len + (noff - off);
 614                         n->m_next = n0;
 615                 } else {
 616                         nip6 = mtod(n, struct ip6_hdr *);
 617                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 618                             sizeof(*nicmp6));
 619                         noff = off;
 620                 }
 621                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 622                 nicmp6->icmp6_code = 0;
 623                 if (n) {
 624                         ICMP6STAT_INC(icp6s_reflect);
 625                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 626                         icmp6_reflect(n, noff);
 627                 }
 628                 break;
 629
 630         case ICMP6_ECHO_REPLY:
 631                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 632                 if (code != 0)
 633                         goto badcode;
 634                 break;
 635
 636         case MLD_LISTENER_QUERY:
 637         case MLD_LISTENER_REPORT:
 638         case MLD_LISTENER_DONE:
 639         case MLDV2_LISTENER_REPORT:
 640                 /*
 641                  * Drop MLD traffic which is not link-local, has a hop limit
 642                  * of greater than 1 hop, or which does not have the
 643                  * IPv6 HBH Router Alert option.
 644                  * As IPv6 HBH options are stripped in ip6_input() we must
 645                  * check an mbuf header flag.
 646                  * XXX Should we also sanity check that these messages
 647                  * were directed to a link-local multicast prefix?
 648                  */
 649                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 650                         goto freeit;
 651                 if (mld_input(m, off, icmp6len) != 0)
 652                         return (IPPROTO_DONE);
 653                 /* m stays. */
 654                 break;
 655
 656         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 657             {
 658                 enum { WRU, FQDN } mode;
 659
 660                 if (!V_icmp6_nodeinfo)
 661                         break;
 662
 663                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 664                         mode = WRU;
 665                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 666                         mode = FQDN;
 667                 else
 668                         goto badlen;
 669
 670                 if (mode == FQDN) {
 671 #ifndef PULLDOWN_TEST
 672                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 673                             IPPROTO_DONE);
 674 #endif
 675                         n = m_copy(m, 0, M_COPYALL);
 676                         if (n)
 677                                 n = ni6_input(n, off);
 678                         /* XXX meaningless if n == NULL */
 679                         noff = sizeof(struct ip6_hdr);
 680                 } else {
 681                         struct prison *pr;
 682                         u_char *p;
 683                         int maxlen, maxhlen, hlen;
 684
 685                         /*
 686                          * XXX: this combination of flags is pointless,
 687                          * but should we keep this for compatibility?
 688                          */
 689                         if ((V_icmp6_nodeinfo & 5) != 5)
 690                                 break;
 691
 692                         if (code != 0)
 693                                 goto badcode;
 694                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 695                         if (maxlen >= MCLBYTES) {
 696                                 /* Give up remote */
 697                                 break;
 698                         }
 699                         MGETHDR(n, M_DONTWAIT, m->m_type);
 700                         if (n && maxlen > MHLEN) {
 701                                 MCLGET(n, M_DONTWAIT);
 702                                 if ((n->m_flags & M_EXT) == 0) {
 703                                         m_free(n);
 704                                         n = NULL;
 705                                 }
 706                         }
 707                         if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
 708                                 /*
 709                                  * Previous code did a blind M_COPY_PKTHDR
 710                                  * and said "just for rcvif".  If true, then
 711                                  * we could tolerate the dup failing (due to
 712                                  * the deep copy of the tag chain).  For now
 713                                  * be conservative and just fail.
 714                                  */
 715                                 m_free(n);
 716                                 n = NULL;
 717                         }
 718                         if (n == NULL) {
 719                                 /* Give up remote */
 720                                 break;
 721                         }
 722                         n->m_pkthdr.rcvif = NULL;
 723                         n->m_len = 0;
 724                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 725                         pr = curthread->td_ucred->cr_prison;
 726                         mtx_lock(&pr->pr_mtx);
 727                         hlen = strlen(pr->pr_hostname);
 728                         if (maxhlen > hlen)
 729                                 maxhlen = hlen;
 730                         /*
 731                          * Copy IPv6 and ICMPv6 only.
 732                          */
 733                         nip6 = mtod(n, struct ip6_hdr *);
 734                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 735                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 736                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 737                         p = (u_char *)(nicmp6 + 1);
 738                         bzero(p, 4);
 739                         /* meaningless TTL */
 740                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 741                         mtx_unlock(&pr->pr_mtx);
 742                         noff = sizeof(struct ip6_hdr);
 743                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 744                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 745                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 746                         nicmp6->icmp6_code = 0;
 747                 }
 748                 if (n) {
 749                         ICMP6STAT_INC(icp6s_reflect);
 750                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 751                         icmp6_reflect(n, noff);
 752                 }
 753                 break;
 754             }
 755
 756         case ICMP6_WRUREPLY:
 757                 if (code != 0)
 758                         goto badcode;
 759                 break;
 760
 761         case ND_ROUTER_SOLICIT:
 762                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 763                 if (code != 0)
 764                         goto badcode;
 765                 if (icmp6len < sizeof(struct nd_router_solicit))
 766                         goto badlen;
 767                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 768                         /* give up local */
 769                         nd6_rs_input(m, off, icmp6len);
 770                         m = NULL;
 771                         goto freeit;
 772                 }
 773                 nd6_rs_input(n, off, icmp6len);
 774                 /* m stays. */
 775                 break;
 776
 777         case ND_ROUTER_ADVERT:
 778                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 779                 if (code != 0)
 780                         goto badcode;
 781                 if (icmp6len < sizeof(struct nd_router_advert))
 782                         goto badlen;
 783                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 784                         /* give up local */
 785                         nd6_ra_input(m, off, icmp6len);
 786                         m = NULL;
 787                         goto freeit;
 788                 }
 789                 nd6_ra_input(n, off, icmp6len);
 790                 /* m stays. */
 791                 break;
 792
 793         case ND_NEIGHBOR_SOLICIT:
 794                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 795                 if (code != 0)
 796                         goto badcode;
 797                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 798                         goto badlen;
 799                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 800                         /* give up local */
 801                         nd6_ns_input(m, off, icmp6len);
 802                         m = NULL;
 803                         goto freeit;
 804                 }
 805                 nd6_ns_input(n, off, icmp6len);
 806                 /* m stays. */
 807                 break;
 808
 809         case ND_NEIGHBOR_ADVERT:
 810                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 811                 if (code != 0)
 812                         goto badcode;
 813                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 814                         goto badlen;
 815                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 816                         /* give up local */
 817                         nd6_na_input(m, off, icmp6len);
 818                         m = NULL;
 819                         goto freeit;
 820                 }
 821                 nd6_na_input(n, off, icmp6len);
 822                 /* m stays. */
 823                 break;
 824
 825         case ND_REDIRECT:
 826                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 827                 if (code != 0)
 828                         goto badcode;
 829                 if (icmp6len < sizeof(struct nd_redirect))
 830                         goto badlen;
 831                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 832                         /* give up local */
 833                         icmp6_redirect_input(m, off);
 834                         m = NULL;
 835                         goto freeit;
 836                 }
 837                 icmp6_redirect_input(n, off);
 838                 /* m stays. */
 839                 break;
 840
 841         case ICMP6_ROUTER_RENUMBERING:
 842                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 843                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 844                         goto badcode;
 845                 if (icmp6len < sizeof(struct icmp6_router_renum))
 846                         goto badlen;
 847                 break;
 848
 849         default:
 850                 nd6log((LOG_DEBUG,
 851                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 852                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 853                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 854                     ifp ? ifp->if_index : 0));
 855                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 856                         /* ICMPv6 error: MUST deliver it by spec... */
 857                         code = PRC_NCMDS;
 858                         /* deliver */
 859                 } else {
 860                         /* ICMPv6 informational: MUST not deliver */
 861                         break;
 862                 }
 863         deliver:
 864                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 865                         /* In this case, m should've been freed. */
 866                         return (IPPROTO_DONE);
 867                 }
 868                 break;
 869
 870         badcode:
 871                 ICMP6STAT_INC(icp6s_badcode);
 872                 break;
 873
 874         badlen:
 875                 ICMP6STAT_INC(icp6s_badlen);
 876                 break;
 877         }
 878
 879         /* deliver the packet to appropriate sockets */
 880         icmp6_rip6_input(&m, *offp);
 881
 882         return IPPROTO_DONE;
 883
 884  freeit:
 885         m_freem(m);
 886         return IPPROTO_DONE;
 887 }
 888
 889 static int
 890 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 891 {
 892         struct mbuf *m = *mp;
 893         struct icmp6_hdr *icmp6;
 894         struct ip6_hdr *eip6;
 895         u_int32_t notifymtu;
 896         struct sockaddr_in6 icmp6src, icmp6dst;
 897
 898         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 899                 ICMP6STAT_INC(icp6s_tooshort);
 900                 goto freeit;
 901         }
 902 #ifndef PULLDOWN_TEST
 903         IP6_EXTHDR_CHECK(m, off,
 904             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 905         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 906 #else
 907         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 908             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 909         if (icmp6 == NULL) {
 910                 ICMP6STAT_INC(icp6s_tooshort);
 911                 return (-1);
 912         }
 913 #endif
 914         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 915
 916         /* Detect the upper level protocol */
 917         {
 918                 void (*ctlfunc)(int, struct sockaddr *, void *);
 919                 u_int8_t nxt = eip6->ip6_nxt;
 920                 int eoff = off + sizeof(struct icmp6_hdr) +
 921                     sizeof(struct ip6_hdr);
 922                 struct ip6ctlparam ip6cp;
 923                 struct in6_addr *finaldst = NULL;
 924                 int icmp6type = icmp6->icmp6_type;
 925                 struct ip6_frag *fh;
 926                 struct ip6_rthdr *rth;
 927                 struct ip6_rthdr0 *rth0;
 928                 int rthlen;
 929
 930                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 931                         struct ip6_ext *eh;
 932
 933                         switch (nxt) {
 934                         case IPPROTO_HOPOPTS:
 935                         case IPPROTO_DSTOPTS:
 936                         case IPPROTO_AH:
 937 #ifndef PULLDOWN_TEST
 938                                 IP6_EXTHDR_CHECK(m, 0,
 939                                     eoff + sizeof(struct ip6_ext), -1);
 940                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 941 #else
 942                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 943                                     eoff, sizeof(*eh));
 944                                 if (eh == NULL) {
 945                                         ICMP6STAT_INC(icp6s_tooshort);
 946                                         return (-1);
 947                                 }
 948 #endif
 949
 950                                 if (nxt == IPPROTO_AH)
 951                                         eoff += (eh->ip6e_len + 2) << 2;
 952                                 else
 953                                         eoff += (eh->ip6e_len + 1) << 3;
 954                                 nxt = eh->ip6e_nxt;
 955                                 break;
 956                         case IPPROTO_ROUTING:
 957                                 /*
 958                                  * When the erroneous packet contains a
 959                                  * routing header, we should examine the
 960                                  * header to determine the final destination.
 961                                  * Otherwise, we can't properly update
 962                                  * information that depends on the final
 963                                  * destination (e.g. path MTU).
 964                                  */
 965 #ifndef PULLDOWN_TEST
 966                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 967                                 rth = (struct ip6_rthdr *)
 968                                     (mtod(m, caddr_t) + eoff);
 969 #else
 970                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 971                                     eoff, sizeof(*rth));
 972                                 if (rth == NULL) {
 973                                         ICMP6STAT_INC(icp6s_tooshort);
 974                                         return (-1);
 975                                 }
 976 #endif
 977                                 rthlen = (rth->ip6r_len + 1) << 3;
 978                                 /*
 979                                  * XXX: currently there is no
 980                                  * officially defined type other
 981                                  * than type-0.
 982                                  * Note that if the segment left field
 983                                  * is 0, all intermediate hops must
 984                                  * have been passed.
 985                                  */
 986                                 if (rth->ip6r_segleft &&
 987                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 988                                         int hops;
 989
 990 #ifndef PULLDOWN_TEST
 991                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 992                                         rth0 = (struct ip6_rthdr0 *)
 993                                             (mtod(m, caddr_t) + eoff);
 994 #else
 995                                         IP6_EXTHDR_GET(rth0,
 996                                             struct ip6_rthdr0 *, m,
 997                                             eoff, rthlen);
 998                                         if (rth0 == NULL) {
 999                                                 ICMP6STAT_INC(icp6s_tooshort);
1000                                                 return (-1);
1001                                         }
1002 #endif
1003                                         /* just ignore a bogus header */
1004                                         if ((rth0->ip6r0_len % 2) == 0 &&
1005                                             (hops = rth0->ip6r0_len/2))
1006                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1007                                 }
1008                                 eoff += rthlen;
1009                                 nxt = rth->ip6r_nxt;
1010                                 break;
1011                         case IPPROTO_FRAGMENT:
1012 #ifndef PULLDOWN_TEST
1013                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1014                                     sizeof(struct ip6_frag), -1);
1015                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1016                                     eoff);
1017 #else
1018                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1019                                     eoff, sizeof(*fh));
1020                                 if (fh == NULL) {
1021                                         ICMP6STAT_INC(icp6s_tooshort);
1022                                         return (-1);
1023                                 }
1024 #endif
1025                                 /*
1026                                  * Data after a fragment header is meaningless
1027                                  * unless it is the first fragment, but
1028                                  * we'll go to the notify label for path MTU
1029                                  * discovery.
1030                                  */
1031                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1032                                         goto notify;
1033
1034                                 eoff += sizeof(struct ip6_frag);
1035                                 nxt = fh->ip6f_nxt;
1036                                 break;
1037                         default:
1038                                 /*
1039                                  * This case includes ESP and the No Next
1040                                  * Header.  In such cases going to the notify
1041                                  * label does not have any meaning
1042                                  * (i.e. ctlfunc will be NULL), but we go
1043                                  * anyway since we might have to update
1044                                  * path MTU information.
1045                                  */
1046                                 goto notify;
1047                         }
1048                 }
1049           notify:
1050 #ifndef PULLDOWN_TEST
1051                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1052 #else
1053                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1054                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1055                 if (icmp6 == NULL) {
1056                         ICMP6STAT_INC(icp6s_tooshort);
1057                         return (-1);
1058                 }
1059 #endif
1060
1061                 /*
1062                  * retrieve parameters from the inner IPv6 header, and convert
1063                  * them into sockaddr structures.
1064                  * XXX: there is no guarantee that the source or destination
1065                  * addresses of the inner packet are in the same scope as
1066                  * the addresses of the icmp packet.  But there is no other
1067                  * way to determine the zone.
1068                  */
1069                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1070
1071                 bzero(&icmp6dst, sizeof(icmp6dst));
1072                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1073                 icmp6dst.sin6_family = AF_INET6;
1074                 if (finaldst == NULL)
1075                         icmp6dst.sin6_addr = eip6->ip6_dst;
1076                 else
1077                         icmp6dst.sin6_addr = *finaldst;
1078                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1079                         goto freeit;
1080                 bzero(&icmp6src, sizeof(icmp6src));
1081                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1082                 icmp6src.sin6_family = AF_INET6;
1083                 icmp6src.sin6_addr = eip6->ip6_src;
1084                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1085                         goto freeit;
1086                 icmp6src.sin6_flowinfo =
1087                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1088
1089                 if (finaldst == NULL)
1090                         finaldst = &eip6->ip6_dst;
1091                 ip6cp.ip6c_m = m;
1092                 ip6cp.ip6c_icmp6 = icmp6;
1093                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1094                 ip6cp.ip6c_off = eoff;
1095                 ip6cp.ip6c_finaldst = finaldst;
1096                 ip6cp.ip6c_src = &icmp6src;
1097                 ip6cp.ip6c_nxt = nxt;
1098
1099                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1100                         notifymtu = ntohl(icmp6->icmp6_mtu);
1101                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1102                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1103                 }
1104
1105                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1106                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1107                 if (ctlfunc) {
1108                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1109                             &ip6cp);
1110                 }
1111         }
1112         *mp = m;
1113         return (0);
1114
1115   freeit:
1116         m_freem(m);
1117         return (-1);
1118 }
1119
1120 void
1121 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1122 {
1123         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1124         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1125         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1126         u_int mtu = ntohl(icmp6->icmp6_mtu);
1127         struct in_conninfo inc;
1128
1129 #if 0
1130         /*
1131          * RFC2460 section 5, last paragraph.
1132          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1133          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1134          * due to packet translator in the middle.
1135          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1136          * special handling.
1137          */
1138         if (mtu < IPV6_MMTU)
1139                 return;
1140 #endif
1141
1142         /*
1143          * we reject ICMPv6 too big with abnormally small value.
1144          * XXX what is the good definition of "abnormally small"?
1145          */
1146         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1147                 return;
1148
1149         if (!validated)
1150                 return;
1151
1152         /*
1153          * In case the suggested mtu is less than IPV6_MMTU, we
1154          * only need to remember that it was for above mentioned
1155          * "alwaysfrag" case.
1156          * Try to be as close to the spec as possible.
1157          */
1158         if (mtu < IPV6_MMTU)
1159                 mtu = IPV6_MMTU - 8;
1160
1161         bzero(&inc, sizeof(inc));
1162         inc.inc_flags |= INC_ISIPV6;
1163         inc.inc6_faddr = *dst;
1164         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1165                 return;
1166
1167         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1168                 tcp_hc_updatemtu(&inc, mtu);
1169                 ICMP6STAT_INC(icp6s_pmtuchg);
1170         }
1171 }
1172
1173 /*
1174  * Process a Node Information Query packet, based on
1175  * draft-ietf-ipngwg-icmp-name-lookups-07.
1176  *
1177  * Spec incompatibilities:
1178  * - IPv6 Subject address handling
1179  * - IPv4 Subject address handling support missing
1180  * - Proxy reply (answer even if it's not for me)
1181  * - joins NI group address at in6_ifattach() time only, does not cope
1182  *   with hostname changes by sethostname(3)
1183  */
1184 static struct mbuf *
1185 ni6_input(struct mbuf *m, int off)
1186 {
1187         struct icmp6_nodeinfo *ni6, *nni6;
1188         struct mbuf *n = NULL;
1189         struct prison *pr;
1190         u_int16_t qtype;
1191         int subjlen;
1192         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1193         struct ni_reply_fqdn *fqdn;
1194         int addrs;              /* for NI_QTYPE_NODEADDR */
1195         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1196         struct in6_addr in6_subj; /* subject address */
1197         struct ip6_hdr *ip6;
1198         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1199         char *subj = NULL;
1200         struct in6_ifaddr *ia6 = NULL;
1201
1202         ip6 = mtod(m, struct ip6_hdr *);
1203 #ifndef PULLDOWN_TEST
1204         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1205 #else
1206         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1207         if (ni6 == NULL) {
1208                 /* m is already reclaimed */
1209                 return (NULL);
1210         }
1211 #endif
1212
1213         /*
1214          * Validate IPv6 source address.
1215          * The default configuration MUST be to refuse answering queries from
1216          * global-scope addresses according to RFC4602.
1217          * Notes:
1218          *  - it's not very clear what "refuse" means; this implementation
1219          *    simply drops it.
1220          *  - it's not very easy to identify global-scope (unicast) addresses
1221          *    since there are many prefixes for them.  It should be safer
1222          *    and in practice sufficient to check "all" but loopback and
1223          *    link-local (note that site-local unicast was deprecated and
1224          *    ULA is defined as global scope-wise)
1225          */
1226         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1227             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1228             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1229                 goto bad;
1230
1231         /*
1232          * Validate IPv6 destination address.
1233          *
1234          * The Responder must discard the Query without further processing
1235          * unless it is one of the Responder's unicast or anycast addresses, or
1236          * a link-local scope multicast address which the Responder has joined.
1237          * [RFC4602, Section 5.]
1238          */
1239         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1240                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1241                         goto bad;
1242                 /* else it's a link-local multicast, fine */
1243         } else {                /* unicast or anycast */
1244                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1245                         goto bad; /* XXX impossible */
1246
1247                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1248                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1249                         ifa_free(&ia6->ia_ifa);
1250                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1251                                 "a temporary address in %s:%d",
1252                                __FILE__, __LINE__));
1253                         goto bad;
1254                 }
1255                 ifa_free(&ia6->ia_ifa);
1256         }
1257
1258         /* validate query Subject field. */
1259         qtype = ntohs(ni6->ni_qtype);
1260         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1261         switch (qtype) {
1262         case NI_QTYPE_NOOP:
1263         case NI_QTYPE_SUPTYPES:
1264                 /* 07 draft */
1265                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1266                         break;
1267                 /* FALLTHROUGH */
1268         case NI_QTYPE_FQDN:
1269         case NI_QTYPE_NODEADDR:
1270         case NI_QTYPE_IPV4ADDR:
1271                 switch (ni6->ni_code) {
1272                 case ICMP6_NI_SUBJ_IPV6:
1273 #if ICMP6_NI_SUBJ_IPV6 != 0
1274                 case 0:
1275 #endif
1276                         /*
1277                          * backward compatibility - try to accept 03 draft
1278                          * format, where no Subject is present.
1279                          */
1280                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1281                             subjlen == 0) {
1282                                 oldfqdn++;
1283                                 break;
1284                         }
1285 #if ICMP6_NI_SUBJ_IPV6 != 0
1286                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1287                                 goto bad;
1288 #endif
1289
1290                         if (subjlen != sizeof(struct in6_addr))
1291                                 goto bad;
1292
1293                         /*
1294                          * Validate Subject address.
1295                          *
1296                          * Not sure what exactly "address belongs to the node"
1297                          * means in the spec, is it just unicast, or what?
1298                          *
1299                          * At this moment we consider Subject address as
1300                          * "belong to the node" if the Subject address equals
1301                          * to the IPv6 destination address; validation for
1302                          * IPv6 destination address should have done enough
1303                          * check for us.
1304                          *
1305                          * We do not do proxy at this moment.
1306                          */
1307                         /* m_pulldown instead of copy? */
1308                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1309                             subjlen, (caddr_t)&in6_subj);
1310                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1311                                 goto bad;
1312
1313                         subj = (char *)&in6_subj;
1314                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1315                                 break;
1316
1317                         /*
1318                          * XXX if we are to allow other cases, we should really
1319                          * be careful about scope here.
1320                          * basically, we should disallow queries toward IPv6
1321                          * destination X with subject Y,
1322                          * if scope(X) > scope(Y).
1323                          * if we allow scope(X) > scope(Y), it will result in
1324                          * information leakage across scope boundary.
1325                          */
1326                         goto bad;
1327
1328                 case ICMP6_NI_SUBJ_FQDN:
1329                         /*
1330                          * Validate Subject name with gethostname(3).
1331                          *
1332                          * The behavior may need some debate, since:
1333                          * - we are not sure if the node has FQDN as
1334                          *   hostname (returned by gethostname(3)).
1335                          * - the code does wildcard match for truncated names.
1336                          *   however, we are not sure if we want to perform
1337                          *   wildcard match, if gethostname(3) side has
1338                          *   truncated hostname.
1339                          */
1340                         pr = curthread->td_ucred->cr_prison;
1341                         mtx_lock(&pr->pr_mtx);
1342                         n = ni6_nametodns(pr->pr_hostname,
1343                             strlen(pr->pr_hostname), 0);
1344                         mtx_unlock(&pr->pr_mtx);
1345                         if (!n || n->m_next || n->m_len == 0)
1346                                 goto bad;
1347                         IP6_EXTHDR_GET(subj, char *, m,
1348                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1349                         if (subj == NULL)
1350                                 goto bad;
1351                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1352                             n->m_len)) {
1353                                 goto bad;
1354                         }
1355                         m_freem(n);
1356                         n = NULL;
1357                         break;
1358
1359                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1360                 default:
1361                         goto bad;
1362                 }
1363                 break;
1364         }
1365
1366         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1367         switch (qtype) {
1368         case NI_QTYPE_FQDN:
1369                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1370                         goto bad;
1371                 break;
1372         case NI_QTYPE_NODEADDR:
1373         case NI_QTYPE_IPV4ADDR:
1374                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1375                         goto bad;
1376                 break;
1377         }
1378
1379         /* guess reply length */
1380         switch (qtype) {
1381         case NI_QTYPE_NOOP:
1382                 break;          /* no reply data */
1383         case NI_QTYPE_SUPTYPES:
1384                 replylen += sizeof(u_int32_t);
1385                 break;
1386         case NI_QTYPE_FQDN:
1387                 /* XXX will append an mbuf */
1388                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1389                 break;
1390         case NI_QTYPE_NODEADDR:
1391                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1392                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1393                     sizeof(u_int32_t))) > MCLBYTES)
1394                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1395                 break;
1396         case NI_QTYPE_IPV4ADDR:
1397                 /* unsupported - should respond with unknown Qtype? */
1398                 break;
1399         default:
1400                 /*
1401                  * XXX: We must return a reply with the ICMP6 code
1402                  * `unknown Qtype' in this case.  However we regard the case
1403                  * as an FQDN query for backward compatibility.
1404                  * Older versions set a random value to this field,
1405                  * so it rarely varies in the defined qtypes.
1406                  * But the mechanism is not reliable...
1407                  * maybe we should obsolete older versions.
1408                  */
1409                 qtype = NI_QTYPE_FQDN;
1410                 /* XXX will append an mbuf */
1411                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1412                 oldfqdn++;
1413                 break;
1414         }
1415
1416         /* allocate an mbuf to reply. */
1417         MGETHDR(n, M_DONTWAIT, m->m_type);
1418         if (n == NULL) {
1419                 m_freem(m);
1420                 return (NULL);
1421         }
1422         M_MOVE_PKTHDR(n, m); /* just for recvif */
1423         if (replylen > MHLEN) {
1424                 if (replylen > MCLBYTES) {
1425                         /*
1426                          * XXX: should we try to allocate more? But MCLBYTES
1427                          * is probably much larger than IPV6_MMTU...
1428                          */
1429                         goto bad;
1430                 }
1431                 MCLGET(n, M_DONTWAIT);
1432                 if ((n->m_flags & M_EXT) == 0) {
1433                         goto bad;
1434                 }
1435         }
1436         n->m_pkthdr.len = n->m_len = replylen;
1437
1438         /* copy mbuf header and IPv6 + Node Information base headers */
1439         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1440         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1441         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1442
1443         /* qtype dependent procedure */
1444         switch (qtype) {
1445         case NI_QTYPE_NOOP:
1446                 nni6->ni_code = ICMP6_NI_SUCCESS;
1447                 nni6->ni_flags = 0;
1448                 break;
1449         case NI_QTYPE_SUPTYPES:
1450         {
1451                 u_int32_t v;
1452                 nni6->ni_code = ICMP6_NI_SUCCESS;
1453                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1454                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1455                 v = (u_int32_t)htonl(0x0000000f);
1456                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1457                 break;
1458         }
1459         case NI_QTYPE_FQDN:
1460                 nni6->ni_code = ICMP6_NI_SUCCESS;
1461                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1462                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1463                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1464                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1465                 /*
1466                  * XXX do we really have FQDN in hostname?
1467                  */
1468                 pr = curthread->td_ucred->cr_prison;
1469                 mtx_lock(&pr->pr_mtx);
1470                 n->m_next = ni6_nametodns(pr->pr_hostname,
1471                     strlen(pr->pr_hostname), oldfqdn);
1472                 mtx_unlock(&pr->pr_mtx);
1473                 if (n->m_next == NULL)
1474                         goto bad;
1475                 /* XXX we assume that n->m_next is not a chain */
1476                 if (n->m_next->m_next != NULL)
1477                         goto bad;
1478                 n->m_pkthdr.len += n->m_next->m_len;
1479                 break;
1480         case NI_QTYPE_NODEADDR:
1481         {
1482                 int lenlim, copied;
1483
1484                 nni6->ni_code = ICMP6_NI_SUCCESS;
1485                 n->m_pkthdr.len = n->m_len =
1486                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1487                 lenlim = M_TRAILINGSPACE(n);
1488                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1489                 /* XXX: reset mbuf length */
1490                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1491                     sizeof(struct icmp6_nodeinfo) + copied;
1492                 break;
1493         }
1494         default:
1495                 break;          /* XXX impossible! */
1496         }
1497
1498         nni6->ni_type = ICMP6_NI_REPLY;
1499         m_freem(m);
1500         return (n);
1501
1502   bad:
1503         m_freem(m);
1504         if (n)
1505                 m_freem(n);
1506         return (NULL);
1507 }
1508
1509 /*
1510  * make a mbuf with DNS-encoded string.  no compression support.
1511  *
1512  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1513  * treated as truncated name (two \0 at the end).  this is a wild guess.
1514  *
1515  * old - return pascal string if non-zero
1516  */
1517 static struct mbuf *
1518 ni6_nametodns(const char *name, int namelen, int old)
1519 {
1520         struct mbuf *m;
1521         char *cp, *ep;
1522         const char *p, *q;
1523         int i, len, nterm;
1524
1525         if (old)
1526                 len = namelen + 1;
1527         else
1528                 len = MCLBYTES;
1529
1530         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1531         MGET(m, M_DONTWAIT, MT_DATA);
1532         if (m && len > MLEN) {
1533                 MCLGET(m, M_DONTWAIT);
1534                 if ((m->m_flags & M_EXT) == 0)
1535                         goto fail;
1536         }
1537         if (!m)
1538                 goto fail;
1539         m->m_next = NULL;
1540
1541         if (old) {
1542                 m->m_len = len;
1543                 *mtod(m, char *) = namelen;
1544                 bcopy(name, mtod(m, char *) + 1, namelen);
1545                 return m;
1546         } else {
1547                 m->m_len = 0;
1548                 cp = mtod(m, char *);
1549                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1550
1551                 /* if not certain about my name, return empty buffer */
1552                 if (namelen == 0)
1553                         return m;
1554
1555                 /*
1556                  * guess if it looks like shortened hostname, or FQDN.
1557                  * shortened hostname needs two trailing "\0".
1558                  */
1559                 i = 0;
1560                 for (p = name; p < name + namelen; p++) {
1561                         if (*p && *p == '.')
1562                                 i++;
1563                 }
1564                 if (i < 2)
1565                         nterm = 2;
1566                 else
1567                         nterm = 1;
1568
1569                 p = name;
1570                 while (cp < ep && p < name + namelen) {
1571                         i = 0;
1572                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1573                                 i++;
1574                         /* result does not fit into mbuf */
1575                         if (cp + i + 1 >= ep)
1576                                 goto fail;
1577                         /*
1578                          * DNS label length restriction, RFC1035 page 8.
1579                          * "i == 0" case is included here to avoid returning
1580                          * 0-length label on "foo..bar".
1581                          */
1582                         if (i <= 0 || i >= 64)
1583                                 goto fail;
1584                         *cp++ = i;
1585                         bcopy(p, cp, i);
1586                         cp += i;
1587                         p = q;
1588                         if (p < name + namelen && *p == '.')
1589                                 p++;
1590                 }
1591                 /* termination */
1592                 if (cp + nterm >= ep)
1593                         goto fail;
1594                 while (nterm-- > 0)
1595                         *cp++ = '\0';
1596                 m->m_len = cp - mtod(m, char *);
1597                 return m;
1598         }
1599
1600         panic("should not reach here");
1601         /* NOTREACHED */
1602
1603  fail:
1604         if (m)
1605                 m_freem(m);
1606         return NULL;
1607 }
1608
1609 /*
1610  * check if two DNS-encoded string matches.  takes care of truncated
1611  * form (with \0\0 at the end).  no compression support.
1612  * XXX upper/lowercase match (see RFC2065)
1613  */
1614 static int
1615 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1616 {
1617         const char *a0, *b0;
1618         int l;
1619
1620         /* simplest case - need validation? */
1621         if (alen == blen && bcmp(a, b, alen) == 0)
1622                 return 1;
1623
1624         a0 = a;
1625         b0 = b;
1626
1627         /* termination is mandatory */
1628         if (alen < 2 || blen < 2)
1629                 return 0;
1630         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1631                 return 0;
1632         alen--;
1633         blen--;
1634
1635         while (a - a0 < alen && b - b0 < blen) {
1636                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1637                         return 0;
1638
1639                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1640                         return 0;
1641                 /* we don't support compression yet */
1642                 if (a[0] >= 64 || b[0] >= 64)
1643                         return 0;
1644
1645                 /* truncated case */
1646                 if (a[0] == 0 && a - a0 == alen - 1)
1647                         return 1;
1648                 if (b[0] == 0 && b - b0 == blen - 1)
1649                         return 1;
1650                 if (a[0] == 0 || b[0] == 0)
1651                         return 0;
1652
1653                 if (a[0] != b[0])
1654                         return 0;
1655                 l = a[0];
1656                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1657                         return 0;
1658                 if (bcmp(a + 1, b + 1, l) != 0)
1659                         return 0;
1660
1661                 a += 1 + l;
1662                 b += 1 + l;
1663         }
1664
1665         if (a - a0 == alen && b - b0 == blen)
1666                 return 1;
1667         else
1668                 return 0;
1669 }
1670
1671 /*
1672  * calculate the number of addresses to be returned in the node info reply.
1673  */
1674 static int
1675 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1676     struct in6_addr *subj)
1677 {
1678         struct ifnet *ifp;
1679         struct in6_ifaddr *ifa6;
1680         struct ifaddr *ifa;
1681         int addrs = 0, addrsofif, iffound = 0;
1682         int niflags = ni6->ni_flags;
1683
1684         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1685                 switch (ni6->ni_code) {
1686                 case ICMP6_NI_SUBJ_IPV6:
1687                         if (subj == NULL) /* must be impossible... */
1688                                 return (0);
1689                         break;
1690                 default:
1691                         /*
1692                          * XXX: we only support IPv6 subject address for
1693                          * this Qtype.
1694                          */
1695                         return (0);
1696                 }
1697         }
1698
1699         IFNET_RLOCK_NOSLEEP();
1700         for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1701                 addrsofif = 0;
1702                 IF_ADDR_LOCK(ifp);
1703                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1704                         if (ifa->ifa_addr->sa_family != AF_INET6)
1705                                 continue;
1706                         ifa6 = (struct in6_ifaddr *)ifa;
1707
1708                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1709                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1710                                 iffound = 1;
1711
1712                         /*
1713                          * IPv4-mapped addresses can only be returned by a
1714                          * Node Information proxy, since they represent
1715                          * addresses of IPv4-only nodes, which perforce do
1716                          * not implement this protocol.
1717                          * [icmp-name-lookups-07, Section 5.4]
1718                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1719                          * this function at this moment.
1720                          */
1721
1722                         /* What do we have to do about ::1? */
1723                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1724                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1725                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1726                                         continue;
1727                                 break;
1728                         case IPV6_ADDR_SCOPE_SITELOCAL:
1729                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1730                                         continue;
1731                                 break;
1732                         case IPV6_ADDR_SCOPE_GLOBAL:
1733                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1734                                         continue;
1735                                 break;
1736                         default:
1737                                 continue;
1738                         }
1739
1740                         /*
1741                          * check if anycast is okay.
1742                          * XXX: just experimental.  not in the spec.
1743                          */
1744                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1745                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1746                                 continue; /* we need only unicast addresses */
1747                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1748                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1749                                 continue;
1750                         }
1751                         addrsofif++; /* count the address */
1752                 }
1753                 IF_ADDR_UNLOCK(ifp);
1754                 if (iffound) {
1755                         *ifpp = ifp;
1756                         IFNET_RUNLOCK_NOSLEEP();
1757                         return (addrsofif);
1758                 }
1759
1760                 addrs += addrsofif;
1761         }
1762         IFNET_RUNLOCK_NOSLEEP();
1763
1764         return (addrs);
1765 }
1766
1767 static int
1768 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1769     struct ifnet *ifp0, int resid)
1770 {
1771         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1772         struct in6_ifaddr *ifa6;
1773         struct ifaddr *ifa;
1774         struct ifnet *ifp_dep = NULL;
1775         int copied = 0, allow_deprecated = 0;
1776         u_char *cp = (u_char *)(nni6 + 1);
1777         int niflags = ni6->ni_flags;
1778         u_int32_t ltime;
1779
1780         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1781                 return (0);     /* needless to copy */
1782
1783         IFNET_RLOCK_NOSLEEP();
1784   again:
1785
1786         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1787                 IF_ADDR_LOCK(ifp);
1788                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1789                         if (ifa->ifa_addr->sa_family != AF_INET6)
1790                                 continue;
1791                         ifa6 = (struct in6_ifaddr *)ifa;
1792
1793                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1794                             allow_deprecated == 0) {
1795                                 /*
1796                                  * prefererred address should be put before
1797                                  * deprecated addresses.
1798                                  */
1799
1800                                 /* record the interface for later search */
1801                                 if (ifp_dep == NULL)
1802                                         ifp_dep = ifp;
1803
1804                                 continue;
1805                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1806                             allow_deprecated != 0)
1807                                 continue; /* we now collect deprecated addrs */
1808
1809                         /* What do we have to do about ::1? */
1810                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1811                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1812                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1813                                         continue;
1814                                 break;
1815                         case IPV6_ADDR_SCOPE_SITELOCAL:
1816                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1817                                         continue;
1818                                 break;
1819                         case IPV6_ADDR_SCOPE_GLOBAL:
1820                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1821                                         continue;
1822                                 break;
1823                         default:
1824                                 continue;
1825                         }
1826
1827                         /*
1828                          * check if anycast is okay.
1829                          * XXX: just experimental.  not in the spec.
1830                          */
1831                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1832                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1833                                 continue;
1834                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1835                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1836                                 continue;
1837                         }
1838
1839                         /* now we can copy the address */
1840                         if (resid < sizeof(struct in6_addr) +
1841                             sizeof(u_int32_t)) {
1842                                 IF_ADDR_UNLOCK(ifp);
1843                                 /*
1844                                  * We give up much more copy.
1845                                  * Set the truncate flag and return.
1846                                  */
1847                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1848                                 IFNET_RUNLOCK_NOSLEEP();
1849                                 return (copied);
1850                         }
1851
1852                         /*
1853                          * Set the TTL of the address.
1854                          * The TTL value should be one of the following
1855                          * according to the specification:
1856                          *
1857                          * 1. The remaining lifetime of a DHCP lease on the
1858                          *    address, or
1859                          * 2. The remaining Valid Lifetime of a prefix from
1860                          *    which the address was derived through Stateless
1861                          *    Autoconfiguration.
1862                          *
1863                          * Note that we currently do not support stateful
1864                          * address configuration by DHCPv6, so the former
1865                          * case can't happen.
1866                          */
1867                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1868                                 ltime = ND6_INFINITE_LIFETIME;
1869                         else {
1870                                 if (ifa6->ia6_lifetime.ia6t_expire >
1871                                     time_second)
1872                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1873                                 else
1874                                         ltime = 0;
1875                         }
1876
1877                         bcopy(&ltime, cp, sizeof(u_int32_t));
1878                         cp += sizeof(u_int32_t);
1879
1880                         /* copy the address itself */
1881                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1882                             sizeof(struct in6_addr));
1883                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1884                         cp += sizeof(struct in6_addr);
1885
1886                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1887                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1888                 }
1889                 IF_ADDR_UNLOCK(ifp);
1890                 if (ifp0)       /* we need search only on the specified IF */
1891                         break;
1892         }
1893
1894         if (allow_deprecated == 0 && ifp_dep != NULL) {
1895                 ifp = ifp_dep;
1896                 allow_deprecated = 1;
1897
1898                 goto again;
1899         }
1900
1901         IFNET_RUNLOCK_NOSLEEP();
1902
1903         return (copied);
1904 }
1905
1906 /*
1907  * XXX almost dup'ed code with rip6_input.
1908  */
1909 static int
1910 icmp6_rip6_input(struct mbuf **mp, int off)
1911 {
1912         struct mbuf *m = *mp;
1913         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1914         struct inpcb *in6p;
1915         struct inpcb *last = NULL;
1916         struct sockaddr_in6 fromsa;
1917         struct icmp6_hdr *icmp6;
1918         struct mbuf *opts = NULL;
1919
1920 #ifndef PULLDOWN_TEST
1921         /* this is assumed to be safe. */
1922         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1923 #else
1924         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1925         if (icmp6 == NULL) {
1926                 /* m is already reclaimed */
1927                 return (IPPROTO_DONE);
1928         }
1929 #endif
1930
1931         /*
1932          * XXX: the address may have embedded scope zone ID, which should be
1933          * hidden from applications.
1934          */
1935         bzero(&fromsa, sizeof(fromsa));
1936         fromsa.sin6_family = AF_INET6;
1937         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1938         fromsa.sin6_addr = ip6->ip6_src;
1939         if (sa6_recoverscope(&fromsa)) {
1940                 m_freem(m);
1941                 return (IPPROTO_DONE);
1942         }
1943
1944         INP_INFO_RLOCK(&V_ripcbinfo);
1945         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1946                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1947                         continue;
1948                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1949                         continue;
1950                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1951                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1952                         continue;
1953                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1954                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1955                         continue;
1956                 INP_RLOCK(in6p);
1957                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1958                     in6p->in6p_icmp6filt)) {
1959                         INP_RUNLOCK(in6p);
1960                         continue;
1961                 }
1962                 if (last != NULL) {
1963                         struct  mbuf *n = NULL;
1964
1965                         /*
1966                          * Recent network drivers tend to allocate a single
1967                          * mbuf cluster, rather than to make a couple of
1968                          * mbufs without clusters.  Also, since the IPv6 code
1969                          * path tries to avoid m_pullup(), it is highly
1970                          * probable that we still have an mbuf cluster here
1971                          * even though the necessary length can be stored in an
1972                          * mbuf's internal buffer.
1973                          * Meanwhile, the default size of the receive socket
1974                          * buffer for raw sockets is not so large.  This means
1975                          * the possibility of packet loss is relatively higher
1976                          * than before.  To avoid this scenario, we copy the
1977                          * received data to a separate mbuf that does not use
1978                          * a cluster, if possible.
1979                          * XXX: it is better to copy the data after stripping
1980                          * intermediate headers.
1981                          */
1982                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1983                             m->m_len <= MHLEN) {
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,
1988                                                       m->m_len);
1989                                                 n->m_len = m->m_len;
1990                                         } else {
1991                                                 m_free(n);
1992                                                 n = NULL;
1993                                         }
1994                                 }
1995                         }
1996                         if (n != NULL ||
1997                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1998                                 if (last->inp_flags & INP_CONTROLOPTS)
1999                                         ip6_savecontrol(last, n, &opts);
2000                                 /* strip intermediate headers */
2001                                 m_adj(n, off);
2002                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2003                                 if (sbappendaddr_locked(
2004                                     &last->inp_socket->so_rcv,
2005                                     (struct sockaddr *)&fromsa, n, opts)
2006                                     == 0) {
2007                                         /* should notify about lost packet */
2008                                         m_freem(n);
2009                                         if (opts) {
2010                                                 m_freem(opts);
2011                                         }
2012                                         SOCKBUF_UNLOCK(
2013                                             &last->inp_socket->so_rcv);
2014                                 } else
2015                                         sorwakeup_locked(last->inp_socket);
2016                                 opts = NULL;
2017                         }
2018                         INP_RUNLOCK(last);
2019                 }
2020                 last = in6p;
2021         }
2022         INP_INFO_RUNLOCK(&V_ripcbinfo);
2023         if (last != NULL) {
2024                 if (last->inp_flags & INP_CONTROLOPTS)
2025                         ip6_savecontrol(last, m, &opts);
2026                 /* strip intermediate headers */
2027                 m_adj(m, off);
2028
2029                 /* avoid using mbuf clusters if possible (see above) */
2030                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2031                     m->m_len <= MHLEN) {
2032                         struct mbuf *n;
2033
2034                         MGET(n, M_DONTWAIT, m->m_type);
2035                         if (n != NULL) {
2036                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2037                                         bcopy(m->m_data, n->m_data, m->m_len);
2038                                         n->m_len = m->m_len;
2039
2040                                         m_freem(m);
2041                                         m = n;
2042                                 } else {
2043                                         m_freem(n);
2044                                         n = NULL;
2045                                 }
2046                         }
2047                 }
2048                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2049                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2050                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2051                         m_freem(m);
2052                         if (opts)
2053                                 m_freem(opts);
2054                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2055                 } else
2056                         sorwakeup_locked(last->inp_socket);
2057                 INP_RUNLOCK(last);
2058         } else {
2059                 m_freem(m);
2060                 IP6STAT_DEC(ip6s_delivered);
2061         }
2062         return IPPROTO_DONE;
2063 }
2064
2065 /*
2066  * Reflect the ip6 packet back to the source.
2067  * OFF points to the icmp6 header, counted from the top of the mbuf.
2068  */
2069 void
2070 icmp6_reflect(struct mbuf *m, size_t off)
2071 {
2072         struct ip6_hdr *ip6;
2073         struct icmp6_hdr *icmp6;
2074         struct in6_ifaddr *ia = NULL;
2075         int plen;
2076         int type, code;
2077         struct ifnet *outif = NULL;
2078         struct in6_addr origdst, src, *srcp = NULL;
2079
2080         /* too short to reflect */
2081         if (off < sizeof(struct ip6_hdr)) {
2082                 nd6log((LOG_DEBUG,
2083                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2084                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2085                     __FILE__, __LINE__));
2086                 goto bad;
2087         }
2088
2089         /*
2090          * If there are extra headers between IPv6 and ICMPv6, strip
2091          * off that header first.
2092          */
2093 #ifdef DIAGNOSTIC
2094         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2095                 panic("assumption failed in icmp6_reflect");
2096 #endif
2097         if (off > sizeof(struct ip6_hdr)) {
2098                 size_t l;
2099                 struct ip6_hdr nip6;
2100
2101                 l = off - sizeof(struct ip6_hdr);
2102                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2103                 m_adj(m, l);
2104                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2105                 if (m->m_len < l) {
2106                         if ((m = m_pullup(m, l)) == NULL)
2107                                 return;
2108                 }
2109                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2110         } else /* off == sizeof(struct ip6_hdr) */ {
2111                 size_t l;
2112                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2113                 if (m->m_len < l) {
2114                         if ((m = m_pullup(m, l)) == NULL)
2115                                 return;
2116                 }
2117         }
2118         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2119         ip6 = mtod(m, struct ip6_hdr *);
2120         ip6->ip6_nxt = IPPROTO_ICMPV6;
2121         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2122         type = icmp6->icmp6_type; /* keep type for statistics */
2123         code = icmp6->icmp6_code; /* ditto. */
2124
2125         origdst = ip6->ip6_dst;
2126         /*
2127          * ip6_input() drops a packet if its src is multicast.
2128          * So, the src is never multicast.
2129          */
2130         ip6->ip6_dst = ip6->ip6_src;
2131
2132         /*
2133          * If the incoming packet was addressed directly to us (i.e. unicast),
2134          * use dst as the src for the reply.
2135          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2136          * (for example) when we encounter an error while forwarding procedure
2137          * destined to a duplicated address of ours.
2138          * Note that ip6_getdstifaddr() may fail if we are in an error handling
2139          * procedure of an outgoing packet of our own, in which case we need
2140          * to search in the ifaddr list.
2141          */
2142         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2143                 if ((ia = ip6_getdstifaddr(m))) {
2144                         if (!(ia->ia6_flags &
2145                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2146                                 srcp = &ia->ia_addr.sin6_addr;
2147                 } else {
2148                         struct sockaddr_in6 d;
2149
2150                         bzero(&d, sizeof(d));
2151                         d.sin6_family = AF_INET6;
2152                         d.sin6_len = sizeof(d);
2153                         d.sin6_addr = origdst;
2154                         ia = (struct in6_ifaddr *)
2155                             ifa_ifwithaddr((struct sockaddr *)&d);
2156                         if (ia &&
2157                             !(ia->ia6_flags &
2158                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2159                                 srcp = &ia->ia_addr.sin6_addr;
2160                         }
2161                 }
2162         }
2163
2164         if ((srcp != NULL) &&
2165             (in6_addrscope(srcp) != in6_addrscope(&ip6->ip6_src)))
2166                 srcp = NULL;
2167
2168         if (srcp == NULL) {
2169                 int e;
2170                 struct sockaddr_in6 sin6;
2171                 struct route_in6 ro;
2172
2173                 /*
2174                  * This case matches to multicasts, our anycast, or unicasts
2175                  * that we do not own.  Select a source address based on the
2176                  * source address of the erroneous packet.
2177                  */
2178                 bzero(&sin6, sizeof(sin6));
2179                 sin6.sin6_family = AF_INET6;
2180                 sin6.sin6_len = sizeof(sin6);
2181                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2182
2183                 bzero(&ro, sizeof(ro));
2184                 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2185                 if (ro.ro_rt)
2186                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2187                 if (e) {
2188                         char ip6buf[INET6_ADDRSTRLEN];
2189                         nd6log((LOG_DEBUG,
2190                             "icmp6_reflect: source can't be determined: "
2191                             "dst=%s, error=%d\n",
2192                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2193                         goto bad;
2194                 }
2195                 srcp = &src;
2196         }
2197
2198         ip6->ip6_src = *srcp;
2199         ip6->ip6_flow = 0;
2200         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2201         ip6->ip6_vfc |= IPV6_VERSION;
2202         ip6->ip6_nxt = IPPROTO_ICMPV6;
2203         if (outif)
2204                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2205         else if (m->m_pkthdr.rcvif) {
2206                 /* XXX: This may not be the outgoing interface */
2207                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2208         } else
2209                 ip6->ip6_hlim = V_ip6_defhlim;
2210
2211         icmp6->icmp6_cksum = 0;
2212         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2213             sizeof(struct ip6_hdr), plen);
2214
2215         /*
2216          * XXX option handling
2217          */
2218
2219         m->m_flags &= ~(M_BCAST|M_MCAST);
2220
2221         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2222         if (outif)
2223                 icmp6_ifoutstat_inc(outif, type, code);
2224
2225         if (ia != NULL)
2226                 ifa_free(&ia->ia_ifa);
2227         return;
2228
2229  bad:
2230         if (ia != NULL)
2231                 ifa_free(&ia->ia_ifa);
2232         m_freem(m);
2233         return;
2234 }
2235
2236 void
2237 icmp6_fasttimo(void)
2238 {
2239
2240         mld_fasttimo();
2241 }
2242
2243 void
2244 icmp6_slowtimo(void)
2245 {
2246
2247         mld_slowtimo();
2248 }
2249
2250 static const char *
2251 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2252     struct in6_addr *tgt6)
2253 {
2254         static char buf[1024];
2255         char ip6bufs[INET6_ADDRSTRLEN];
2256         char ip6bufd[INET6_ADDRSTRLEN];
2257         char ip6buft[INET6_ADDRSTRLEN];
2258         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2259             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2260             ip6_sprintf(ip6buft, tgt6));
2261         return buf;
2262 }
2263
2264 void
2265 icmp6_redirect_input(struct mbuf *m, int off)
2266 {
2267         struct ifnet *ifp;
2268         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2269         struct nd_redirect *nd_rd;
2270         int icmp6len = ntohs(ip6->ip6_plen);
2271         char *lladdr = NULL;
2272         int lladdrlen = 0;
2273         u_char *redirhdr = NULL;
2274         int redirhdrlen = 0;
2275         struct rtentry *rt = NULL;
2276         int is_router;
2277         int is_onlink;
2278         struct in6_addr src6 = ip6->ip6_src;
2279         struct in6_addr redtgt6;
2280         struct in6_addr reddst6;
2281         union nd_opts ndopts;
2282         char ip6buf[INET6_ADDRSTRLEN];
2283
2284         if (!m)
2285                 return;
2286
2287         ifp = m->m_pkthdr.rcvif;
2288
2289         if (!ifp)
2290                 return;
2291
2292         /* XXX if we are router, we don't update route by icmp6 redirect */
2293         if (V_ip6_forwarding)
2294                 goto freeit;
2295         if (!V_icmp6_rediraccept)
2296                 goto freeit;
2297
2298 #ifndef PULLDOWN_TEST
2299         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2300         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2301 #else
2302         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2303         if (nd_rd == NULL) {
2304                 ICMP6STAT_INC(icp6s_tooshort);
2305                 return;
2306         }
2307 #endif
2308         redtgt6 = nd_rd->nd_rd_target;
2309         reddst6 = nd_rd->nd_rd_dst;
2310
2311         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2312             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2313                 goto freeit;
2314         }
2315
2316         /* validation */
2317         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2318                 nd6log((LOG_ERR,
2319                     "ICMP6 redirect sent from %s rejected; "
2320                     "must be from linklocal\n",
2321                     ip6_sprintf(ip6buf, &src6)));
2322                 goto bad;
2323         }
2324         if (ip6->ip6_hlim != 255) {
2325                 nd6log((LOG_ERR,
2326                     "ICMP6 redirect sent from %s rejected; "
2327                     "hlim=%d (must be 255)\n",
2328                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2329                 goto bad;
2330         }
2331     {
2332         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2333         struct sockaddr_in6 sin6;
2334         struct in6_addr *gw6;
2335
2336         bzero(&sin6, sizeof(sin6));
2337         sin6.sin6_family = AF_INET6;
2338         sin6.sin6_len = sizeof(struct sockaddr_in6);
2339         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2340         rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2341         if (rt) {
2342                 if (rt->rt_gateway == NULL ||
2343                     rt->rt_gateway->sa_family != AF_INET6) {
2344                         nd6log((LOG_ERR,
2345                             "ICMP6 redirect rejected; no route "
2346                             "with inet6 gateway found for redirect dst: %s\n",
2347                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2348                         RTFREE_LOCKED(rt);
2349                         goto bad;
2350                 }
2351
2352                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2353                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2354                         nd6log((LOG_ERR,
2355                             "ICMP6 redirect rejected; "
2356                             "not equal to gw-for-src=%s (must be same): "
2357                             "%s\n",
2358                             ip6_sprintf(ip6buf, gw6),
2359                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2360                         RTFREE_LOCKED(rt);
2361                         goto bad;
2362                 }
2363         } else {
2364                 nd6log((LOG_ERR,
2365                     "ICMP6 redirect rejected; "
2366                     "no route found for redirect dst: %s\n",
2367                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2368                 goto bad;
2369         }
2370         RTFREE_LOCKED(rt);
2371         rt = NULL;
2372     }
2373         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2374                 nd6log((LOG_ERR,
2375                     "ICMP6 redirect rejected; "
2376                     "redirect dst must be unicast: %s\n",
2377                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2378                 goto bad;
2379         }
2380
2381         is_router = is_onlink = 0;
2382         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2383                 is_router = 1;  /* router case */
2384         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2385                 is_onlink = 1;  /* on-link destination case */
2386         if (!is_router && !is_onlink) {
2387                 nd6log((LOG_ERR,
2388                     "ICMP6 redirect rejected; "
2389                     "neither router case nor onlink case: %s\n",
2390                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2391                 goto bad;
2392         }
2393         /* validation passed */
2394
2395         icmp6len -= sizeof(*nd_rd);
2396         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2397         if (nd6_options(&ndopts) < 0) {
2398                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2399                     "invalid ND option, rejected: %s\n",
2400                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2401                 /* nd6_options have incremented stats */
2402                 goto freeit;
2403         }
2404
2405         if (ndopts.nd_opts_tgt_lladdr) {
2406                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2407                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2408         }
2409
2410         if (ndopts.nd_opts_rh) {
2411                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2412                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2413         }
2414
2415         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2416                 nd6log((LOG_INFO,
2417                     "icmp6_redirect_input: lladdrlen mismatch for %s "
2418                     "(if %d, icmp6 packet %d): %s\n",
2419                     ip6_sprintf(ip6buf, &redtgt6),
2420                     ifp->if_addrlen, lladdrlen - 2,
2421                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2422                 goto bad;
2423         }
2424
2425         /* RFC 2461 8.3 */
2426         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2427             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2428
2429         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2430                 /* perform rtredirect */
2431                 struct sockaddr_in6 sdst;
2432                 struct sockaddr_in6 sgw;
2433                 struct sockaddr_in6 ssrc;
2434
2435                 bzero(&sdst, sizeof(sdst));
2436                 bzero(&sgw, sizeof(sgw));
2437                 bzero(&ssrc, sizeof(ssrc));
2438                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2439                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2440                         sizeof(struct sockaddr_in6);
2441                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2442                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2443                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2444                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2445                     (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2446                     (struct sockaddr *)&ssrc);
2447         }
2448         /* finally update cached route in each socket via pfctlinput */
2449     {
2450         struct sockaddr_in6 sdst;
2451
2452         bzero(&sdst, sizeof(sdst));
2453         sdst.sin6_family = AF_INET6;
2454         sdst.sin6_len = sizeof(struct sockaddr_in6);
2455         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2456         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2457 #ifdef IPSEC
2458         key_sa_routechange((struct sockaddr *)&sdst);
2459 #endif /* IPSEC */
2460     }
2461
2462  freeit:
2463         m_freem(m);
2464         return;
2465
2466  bad:
2467         ICMP6STAT_INC(icp6s_badredirect);
2468         m_freem(m);
2469 }
2470
2471 void
2472 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2473 {
2474         struct ifnet *ifp;      /* my outgoing interface */
2475         struct in6_addr *ifp_ll6;
2476         struct in6_addr *router_ll6;
2477         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2478         struct mbuf *m = NULL;  /* newly allocated one */
2479         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2480         struct nd_redirect *nd_rd;
2481         struct llentry *ln = NULL;
2482         size_t maxlen;
2483         u_char *p;
2484         struct ifnet *outif = NULL;
2485         struct sockaddr_in6 src_sa;
2486
2487         icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2488
2489         /* if we are not router, we don't send icmp6 redirect */
2490         if (!V_ip6_forwarding)
2491                 goto fail;
2492
2493         /* sanity check */
2494         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2495                 goto fail;
2496
2497         /*
2498          * Address check:
2499          *  the source address must identify a neighbor, and
2500          *  the destination address must not be a multicast address
2501          *  [RFC 2461, sec 8.2]
2502          */
2503         sip6 = mtod(m0, struct ip6_hdr *);
2504         bzero(&src_sa, sizeof(src_sa));
2505         src_sa.sin6_family = AF_INET6;
2506         src_sa.sin6_len = sizeof(src_sa);
2507         src_sa.sin6_addr = sip6->ip6_src;
2508         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2509                 goto fail;
2510         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2511                 goto fail;      /* what should we do here? */
2512
2513         /* rate limit */
2514         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2515                 goto fail;
2516
2517         /*
2518          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2519          * we almost always ask for an mbuf cluster for simplicity.
2520          * (MHLEN < IPV6_MMTU is almost always true)
2521          */
2522 #if IPV6_MMTU >= MCLBYTES
2523 # error assumption failed about IPV6_MMTU and MCLBYTES
2524 #endif
2525         MGETHDR(m, M_DONTWAIT, MT_HEADER);
2526         if (m && IPV6_MMTU >= MHLEN)
2527                 MCLGET(m, M_DONTWAIT);
2528         if (!m)
2529                 goto fail;
2530         m->m_pkthdr.rcvif = NULL;
2531         m->m_len = 0;
2532         maxlen = M_TRAILINGSPACE(m);
2533         maxlen = min(IPV6_MMTU, maxlen);
2534         /* just for safety */
2535         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2536             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2537                 goto fail;
2538         }
2539
2540         {
2541                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2542                 struct in6_ifaddr *ia;
2543                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2544                                                  IN6_IFF_NOTREADY|
2545                                                  IN6_IFF_ANYCAST)) == NULL)
2546                         goto fail;
2547                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2548                 /* XXXRW: reference released prematurely. */
2549                 ifa_free(&ia->ia_ifa);
2550         }
2551
2552         /* get ip6 linklocal address for the router. */
2553         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2554                 struct sockaddr_in6 *sin6;
2555                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2556                 router_ll6 = &sin6->sin6_addr;
2557                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2558                         router_ll6 = (struct in6_addr *)NULL;
2559         } else
2560                 router_ll6 = (struct in6_addr *)NULL;
2561
2562         /* ip6 */
2563         ip6 = mtod(m, struct ip6_hdr *);
2564         ip6->ip6_flow = 0;
2565         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2566         ip6->ip6_vfc |= IPV6_VERSION;
2567         /* ip6->ip6_plen will be set later */
2568         ip6->ip6_nxt = IPPROTO_ICMPV6;
2569         ip6->ip6_hlim = 255;
2570         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2571         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2572         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2573
2574         /* ND Redirect */
2575         nd_rd = (struct nd_redirect *)(ip6 + 1);
2576         nd_rd->nd_rd_type = ND_REDIRECT;
2577         nd_rd->nd_rd_code = 0;
2578         nd_rd->nd_rd_reserved = 0;
2579         if (rt->rt_flags & RTF_GATEWAY) {
2580                 /*
2581                  * nd_rd->nd_rd_target must be a link-local address in
2582                  * better router cases.
2583                  */
2584                 if (!router_ll6)
2585                         goto fail;
2586                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2587                     sizeof(nd_rd->nd_rd_target));
2588                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2589                     sizeof(nd_rd->nd_rd_dst));
2590         } else {
2591                 /* make sure redtgt == reddst */
2592                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2593                     sizeof(nd_rd->nd_rd_target));
2594                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2595                     sizeof(nd_rd->nd_rd_dst));
2596         }
2597
2598         p = (u_char *)(nd_rd + 1);
2599
2600         if (!router_ll6)
2601                 goto nolladdropt;
2602
2603         {
2604                 /* target lladdr option */
2605                 int len;
2606                 struct nd_opt_hdr *nd_opt;
2607                 char *lladdr;
2608
2609                 IF_AFDATA_LOCK(ifp);
2610                 ln = nd6_lookup(router_ll6, 0, ifp);
2611                 IF_AFDATA_UNLOCK(ifp);
2612                 if (ln == NULL)
2613                         goto nolladdropt;
2614
2615                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2616                 len = (len + 7) & ~7;   /* round by 8 */
2617                 /* safety check */
2618                 if (len + (p - (u_char *)ip6) > maxlen)
2619                         goto nolladdropt;
2620
2621                 if (ln->la_flags & LLE_VALID) {
2622                         nd_opt = (struct nd_opt_hdr *)p;
2623                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2624                         nd_opt->nd_opt_len = len >> 3;
2625                         lladdr = (char *)(nd_opt + 1);
2626                         bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2627                         p += len;
2628                 }
2629         }
2630 nolladdropt:
2631         if (ln != NULL)
2632                 LLE_RUNLOCK(ln);
2633
2634         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2635
2636         /* just to be safe */
2637 #ifdef M_DECRYPTED      /*not openbsd*/
2638         if (m0->m_flags & M_DECRYPTED)
2639                 goto noredhdropt;
2640 #endif
2641         if (p - (u_char *)ip6 > maxlen)
2642                 goto noredhdropt;
2643
2644         {
2645                 /* redirected header option */
2646                 int len;
2647                 struct nd_opt_rd_hdr *nd_opt_rh;
2648
2649                 /*
2650                  * compute the maximum size for icmp6 redirect header option.
2651                  * XXX room for auth header?
2652                  */
2653                 len = maxlen - (p - (u_char *)ip6);
2654                 len &= ~7;
2655
2656                 /* This is just for simplicity. */
2657                 if (m0->m_pkthdr.len != m0->m_len) {
2658                         if (m0->m_next) {
2659                                 m_freem(m0->m_next);
2660                                 m0->m_next = NULL;
2661                         }
2662                         m0->m_pkthdr.len = m0->m_len;
2663                 }
2664
2665                 /*
2666                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2667                  * about padding/truncate rule for the original IP packet.
2668                  * From the discussion on IPv6imp in Feb 1999,
2669                  * the consensus was:
2670                  * - "attach as much as possible" is the goal
2671                  * - pad if not aligned (original size can be guessed by
2672                  *   original ip6 header)
2673                  * Following code adds the padding if it is simple enough,
2674                  * and truncates if not.
2675                  */
2676                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2677                         panic("assumption failed in %s:%d", __FILE__,
2678                             __LINE__);
2679
2680                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2681                         /* not enough room, truncate */
2682                         m0->m_pkthdr.len = m0->m_len = len -
2683                             sizeof(*nd_opt_rh);
2684                 } else {
2685                         /* enough room, pad or truncate */
2686                         size_t extra;
2687
2688                         extra = m0->m_pkthdr.len % 8;
2689                         if (extra) {
2690                                 /* pad if easy enough, truncate if not */
2691                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2692                                         /* pad */
2693                                         m0->m_len += (8 - extra);
2694                                         m0->m_pkthdr.len += (8 - extra);
2695                                 } else {
2696                                         /* truncate */
2697                                         m0->m_pkthdr.len -= extra;
2698                                         m0->m_len -= extra;
2699                                 }
2700                         }
2701                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2702                         m0->m_pkthdr.len = m0->m_len = len -
2703                             sizeof(*nd_opt_rh);
2704                 }
2705
2706                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2707                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2708                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2709                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2710                 p += sizeof(*nd_opt_rh);
2711                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2712
2713                 /* connect m0 to m */
2714                 m_tag_delete_chain(m0, NULL);
2715                 m0->m_flags &= ~M_PKTHDR;
2716                 m->m_next = m0;
2717                 m->m_pkthdr.len = m->m_len + m0->m_len;
2718                 m0 = NULL;
2719         }
2720 noredhdropt:;
2721         if (m0) {
2722                 m_freem(m0);
2723                 m0 = NULL;
2724         }
2725
2726         /* XXX: clear embedded link IDs in the inner header */
2727         in6_clearscope(&sip6->ip6_src);
2728         in6_clearscope(&sip6->ip6_dst);
2729         in6_clearscope(&nd_rd->nd_rd_target);
2730         in6_clearscope(&nd_rd->nd_rd_dst);
2731
2732         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2733
2734         nd_rd->nd_rd_cksum = 0;
2735         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2736             sizeof(*ip6), ntohs(ip6->ip6_plen));
2737
2738         /* send the packet to outside... */
2739         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2740         if (outif) {
2741                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2742                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2743         }
2744         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2745
2746         return;
2747
2748 fail:
2749         if (m)
2750                 m_freem(m);
2751         if (m0)
2752                 m_freem(m0);
2753 }
2754
2755 /*
2756  * ICMPv6 socket option processing.
2757  */
2758 int
2759 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2760 {
2761         int error = 0;
2762         int optlen;
2763         struct inpcb *inp = sotoinpcb(so);
2764         int level, op, optname;
2765
2766         if (sopt) {
2767                 level = sopt->sopt_level;
2768                 op = sopt->sopt_dir;
2769                 optname = sopt->sopt_name;
2770                 optlen = sopt->sopt_valsize;
2771         } else
2772                 level = op = optname = optlen = 0;
2773
2774         if (level != IPPROTO_ICMPV6) {
2775                 return EINVAL;
2776         }
2777
2778         switch (op) {
2779         case PRCO_SETOPT:
2780                 switch (optname) {
2781                 case ICMP6_FILTER:
2782                     {
2783                         struct icmp6_filter ic6f;
2784
2785                         if (optlen != sizeof(ic6f)) {
2786                                 error = EMSGSIZE;
2787                                 break;
2788                         }
2789                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2790                         if (error == 0) {
2791                                 INP_WLOCK(inp);
2792                                 *inp->in6p_icmp6filt = ic6f;
2793                                 INP_WUNLOCK(inp);
2794                         }
2795                         break;
2796                     }
2797
2798                 default:
2799                         error = ENOPROTOOPT;
2800                         break;
2801                 }
2802                 break;
2803
2804         case PRCO_GETOPT:
2805                 switch (optname) {
2806                 case ICMP6_FILTER:
2807                     {
2808                         struct icmp6_filter ic6f;
2809
2810                         INP_RLOCK(inp);
2811                         ic6f = *inp->in6p_icmp6filt;
2812                         INP_RUNLOCK(inp);
2813                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2814                         break;
2815                     }
2816
2817                 default:
2818                         error = ENOPROTOOPT;
2819                         break;
2820                 }
2821                 break;
2822         }
2823
2824         return (error);
2825 }
2826
2827 /*
2828  * Perform rate limit check.
2829  * Returns 0 if it is okay to send the icmp6 packet.
2830  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2831  * limitation.
2832  *
2833  * XXX per-destination/type check necessary?
2834  *
2835  * dst - not used at this moment
2836  * type - not used at this moment
2837  * code - not used at this moment
2838  */
2839 static int
2840 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2841     const int code)
2842 {
2843         int ret;
2844
2845         ret = 0;        /* okay to send */
2846
2847         /* PPS limit */
2848         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2849             V_icmp6errppslim)) {
2850                 /* The packet is subject to rate limit */
2851                 ret++;
2852         }
2853
2854         return ret;
2855 }