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 #include <netinet6/send.h>
 109
 110 #ifdef IPSEC
 111 #include <netipsec/ipsec.h>
 112 #include <netipsec/key.h>
 113 #endif
 114
 115 extern struct domain inet6domain;
 116
 117 VNET_DEFINE(struct icmp6stat, icmp6stat);
 118
 119 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 120 VNET_DECLARE(struct inpcbhead, ripcb);
 121 VNET_DECLARE(int, icmp6errppslim);
 122 static VNET_DEFINE(int, icmp6errpps_count) = 0;
 123 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 124 VNET_DECLARE(int, icmp6_nodeinfo);
 125
 126 #define V_ripcbinfo                     VNET(ripcbinfo)
 127 #define V_ripcb                         VNET(ripcb)
 128 #define V_icmp6errppslim                VNET(icmp6errppslim)
 129 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 130 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 131 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 132
 133 static void icmp6_errcount(int, int);
 134 static int icmp6_rip6_input(struct mbuf **, int);
 135 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 136 static const char *icmp6_redirect_diag(struct in6_addr *,
 137         struct in6_addr *, struct in6_addr *);
 138 static struct mbuf *ni6_input(struct mbuf *, int);
 139 static struct mbuf *ni6_nametodns(const char *, int, int);
 140 static int ni6_dnsmatch(const char *, int, const char *, int);
 141 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 142                           struct ifnet **, struct in6_addr *);
 143 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 144                                 struct ifnet *, int);
 145 static int icmp6_notify_error(struct mbuf **, int, int, int);
 146
 147 /*
 148  * Kernel module interface for updating icmp6stat.  The argument is an index
 149  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 150  * general layout of icmp6stat into the caller, it doesn't encode its
 151  * location, so that future changes to add, for example, per-CPU stats
 152  * support won't cause binary compatibility problems for kernel modules.
 153  */
 154 void
 155 kmod_icmp6stat_inc(int statnum)
 156 {
 157
 158         (*((u_quad_t *)&V_icmp6stat + statnum))++;
 159 }
 160
 161 static void
 162 icmp6_errcount(int type, int code)
 163 {
 164         switch (type) {
 165         case ICMP6_DST_UNREACH:
 166                 switch (code) {
 167                 case ICMP6_DST_UNREACH_NOROUTE:
 168                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 169                         return;
 170                 case ICMP6_DST_UNREACH_ADMIN:
 171                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 172                         return;
 173                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 174                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 175                         return;
 176                 case ICMP6_DST_UNREACH_ADDR:
 177                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 178                         return;
 179                 case ICMP6_DST_UNREACH_NOPORT:
 180                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 181                         return;
 182                 }
 183                 break;
 184         case ICMP6_PACKET_TOO_BIG:
 185                 ICMP6STAT_INC(icp6s_opacket_too_big);
 186                 return;
 187         case ICMP6_TIME_EXCEEDED:
 188                 switch (code) {
 189                 case ICMP6_TIME_EXCEED_TRANSIT:
 190                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 191                         return;
 192                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 193                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 194                         return;
 195                 }
 196                 break;
 197         case ICMP6_PARAM_PROB:
 198                 switch (code) {
 199                 case ICMP6_PARAMPROB_HEADER:
 200                         ICMP6STAT_INC(icp6s_oparamprob_header);
 201                         return;
 202                 case ICMP6_PARAMPROB_NEXTHEADER:
 203                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 204                         return;
 205                 case ICMP6_PARAMPROB_OPTION:
 206                         ICMP6STAT_INC(icp6s_oparamprob_option);
 207                         return;
 208                 }
 209                 break;
 210         case ND_REDIRECT:
 211                 ICMP6STAT_INC(icp6s_oredirect);
 212                 return;
 213         }
 214         ICMP6STAT_INC(icp6s_ounknown);
 215 }
 216
 217 /*
 218  * A wrapper function for icmp6_error() necessary when the erroneous packet
 219  * may not contain enough scope zone information.
 220  */
 221 void
 222 icmp6_error2(struct mbuf *m, int type, int code, int param,
 223     struct ifnet *ifp)
 224 {
 225         struct ip6_hdr *ip6;
 226
 227         if (ifp == NULL)
 228                 return;
 229
 230 #ifndef PULLDOWN_TEST
 231         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 232 #else
 233         if (m->m_len < sizeof(struct ip6_hdr)) {
 234                 m = m_pullup(m, sizeof(struct ip6_hdr));
 235                 if (m == NULL)
 236                         return;
 237         }
 238 #endif
 239
 240         ip6 = mtod(m, struct ip6_hdr *);
 241
 242         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 243                 return;
 244         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 245                 return;
 246
 247         icmp6_error(m, type, code, param);
 248 }
 249
 250 /*
 251  * Generate an error packet of type error in response to bad IP6 packet.
 252  */
 253 void
 254 icmp6_error(struct mbuf *m, int type, int code, int param)
 255 {
 256         struct ip6_hdr *oip6, *nip6;
 257         struct icmp6_hdr *icmp6;
 258         u_int preplen;
 259         int off;
 260         int nxt;
 261
 262         ICMP6STAT_INC(icp6s_error);
 263
 264         /* count per-type-code statistics */
 265         icmp6_errcount(type, code);
 266
 267 #ifdef M_DECRYPTED      /*not openbsd*/
 268         if (m->m_flags & M_DECRYPTED) {
 269                 ICMP6STAT_INC(icp6s_canterror);
 270                 goto freeit;
 271         }
 272 #endif
 273
 274 #ifndef PULLDOWN_TEST
 275         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 276 #else
 277         if (m->m_len < sizeof(struct ip6_hdr)) {
 278                 m = m_pullup(m, sizeof(struct ip6_hdr));
 279                 if (m == NULL)
 280                         return;
 281         }
 282 #endif
 283         oip6 = mtod(m, struct ip6_hdr *);
 284
 285         /*
 286          * If the destination address of the erroneous packet is a multicast
 287          * address, or the packet was sent using link-layer multicast,
 288          * we should basically suppress sending an error (RFC 2463, Section
 289          * 2.4).
 290          * We have two exceptions (the item e.2 in that section):
 291          * - the Packet Too Big message can be sent for path MTU discovery.
 292          * - the Parameter Problem Message that can be allowed an icmp6 error
 293          *   in the option type field.  This check has been done in
 294          *   ip6_unknown_opt(), so we can just check the type and code.
 295          */
 296         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 297              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 298             (type != ICMP6_PACKET_TOO_BIG &&
 299              (type != ICMP6_PARAM_PROB ||
 300               code != ICMP6_PARAMPROB_OPTION)))
 301                 goto freeit;
 302
 303         /*
 304          * RFC 2463, 2.4 (e.5): source address check.
 305          * XXX: the case of anycast source?
 306          */
 307         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 308             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 309                 goto freeit;
 310
 311         /*
 312          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 313          * don't do it.
 314          */
 315         nxt = -1;
 316         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 317         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 318                 struct icmp6_hdr *icp;
 319
 320 #ifndef PULLDOWN_TEST
 321                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 322                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 323 #else
 324                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 325                         sizeof(*icp));
 326                 if (icp == NULL) {
 327                         ICMP6STAT_INC(icp6s_tooshort);
 328                         return;
 329                 }
 330 #endif
 331                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 332                     icp->icmp6_type == ND_REDIRECT) {
 333                         /*
 334                          * ICMPv6 error
 335                          * Special case: for redirect (which is
 336                          * informational) we must not send icmp6 error.
 337                          */
 338                         ICMP6STAT_INC(icp6s_canterror);
 339                         goto freeit;
 340                 } else {
 341                         /* ICMPv6 informational - send the error */
 342                 }
 343         } else {
 344                 /* non-ICMPv6 - send the error */
 345         }
 346
 347         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 348
 349         /* Finally, do rate limitation check. */
 350         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 351                 ICMP6STAT_INC(icp6s_toofreq);
 352                 goto freeit;
 353         }
 354
 355         /*
 356          * OK, ICMP6 can be generated.
 357          */
 358
 359         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 360                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 361
 362         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 363         M_PREPEND(m, preplen, M_DONTWAIT);      /* FIB is also copied over. */
 364         if (m && m->m_len < preplen)
 365                 m = m_pullup(m, preplen);
 366         if (m == NULL) {
 367                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 368                 return;
 369         }
 370
 371         nip6 = mtod(m, struct ip6_hdr *);
 372         nip6->ip6_src  = oip6->ip6_src;
 373         nip6->ip6_dst  = oip6->ip6_dst;
 374
 375         in6_clearscope(&oip6->ip6_src);
 376         in6_clearscope(&oip6->ip6_dst);
 377
 378         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 379         icmp6->icmp6_type = type;
 380         icmp6->icmp6_code = code;
 381         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 382
 383         /*
 384          * icmp6_reflect() is designed to be in the input path.
 385          * icmp6_error() can be called from both input and output path,
 386          * and if we are in output path rcvif could contain bogus value.
 387          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 388          * information in ip header (nip6).
 389          */
 390         m->m_pkthdr.rcvif = NULL;
 391
 392         ICMP6STAT_INC(icp6s_outhist[type]);
 393         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 394
 395         return;
 396
 397   freeit:
 398         /*
 399          * If we can't tell whether or not we can generate ICMP6, free it.
 400          */
 401         m_freem(m);
 402 }
 403
 404 /*
 405  * Process a received ICMP6 message.
 406  */
 407 int
 408 icmp6_input(struct mbuf **mp, int *offp, int proto)
 409 {
 410         struct mbuf *m = *mp, *n;
 411         struct ifnet *ifp;
 412         struct ip6_hdr *ip6, *nip6;
 413         struct icmp6_hdr *icmp6, *nicmp6;
 414         int off = *offp;
 415         int icmp6len = m->m_pkthdr.len - *offp;
 416         int code, sum, noff;
 417         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 418         int ip6len, error;
 419
 420         ifp = m->m_pkthdr.rcvif;
 421
 422 #ifndef PULLDOWN_TEST
 423         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 424         /* m might change if M_LOOP.  So, call mtod after this */
 425 #endif
 426
 427         /*
 428          * Locate icmp6 structure in mbuf, and check
 429          * that not corrupted and of at least minimum length
 430          */
 431
 432         ip6 = mtod(m, struct ip6_hdr *);
 433         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 434         if (icmp6len < sizeof(struct icmp6_hdr)) {
 435                 ICMP6STAT_INC(icp6s_tooshort);
 436                 goto freeit;
 437         }
 438
 439         /*
 440          * Check multicast group membership.
 441          * Note: SSM filters are not applied for ICMPv6 traffic.
 442          */
 443         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 444                 struct in6_multi        *inm;
 445
 446                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 447                 if (inm == NULL) {
 448                         IP6STAT_INC(ip6s_notmember);
 449                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 450                         goto freeit;
 451                 }
 452         }
 453
 454         /*
 455          * calculate the checksum
 456          */
 457 #ifndef PULLDOWN_TEST
 458         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 459 #else
 460         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 461         if (icmp6 == NULL) {
 462                 ICMP6STAT_INC(icp6s_tooshort);
 463                 return IPPROTO_DONE;
 464         }
 465 #endif
 466         code = icmp6->icmp6_code;
 467
 468         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 469                 nd6log((LOG_ERR,
 470                     "ICMP6 checksum error(%d|%x) %s\n",
 471                     icmp6->icmp6_type, sum,
 472                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 473                 ICMP6STAT_INC(icp6s_checksum);
 474                 goto freeit;
 475         }
 476
 477         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 478                 /*
 479                  * Deliver very specific ICMP6 type only.
 480                  * This is important to deliver TOOBIG.  Otherwise PMTUD
 481                  * will not work.
 482                  */
 483                 switch (icmp6->icmp6_type) {
 484                 case ICMP6_DST_UNREACH:
 485                 case ICMP6_PACKET_TOO_BIG:
 486                 case ICMP6_TIME_EXCEEDED:
 487                         break;
 488                 default:
 489                         goto freeit;
 490                 }
 491         }
 492
 493         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 494         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 495         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 496                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 497
 498         switch (icmp6->icmp6_type) {
 499         case ICMP6_DST_UNREACH:
 500                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 501                 switch (code) {
 502                 case ICMP6_DST_UNREACH_NOROUTE:
 503                         code = PRC_UNREACH_NET;
 504                         break;
 505                 case ICMP6_DST_UNREACH_ADMIN:
 506                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 507                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 508                         break;
 509                 case ICMP6_DST_UNREACH_ADDR:
 510                         code = PRC_HOSTDEAD;
 511                         break;
 512                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 513                         /* I mean "source address was incorrect." */
 514                         code = PRC_PARAMPROB;
 515                         break;
 516                 case ICMP6_DST_UNREACH_NOPORT:
 517                         code = PRC_UNREACH_PORT;
 518                         break;
 519                 default:
 520                         goto badcode;
 521                 }
 522                 goto deliver;
 523                 break;
 524
 525         case ICMP6_PACKET_TOO_BIG:
 526                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 527
 528                 /* validation is made in icmp6_mtudisc_update */
 529
 530                 code = PRC_MSGSIZE;
 531
 532                 /*
 533                  * Updating the path MTU will be done after examining
 534                  * intermediate extension headers.
 535                  */
 536                 goto deliver;
 537                 break;
 538
 539         case ICMP6_TIME_EXCEEDED:
 540                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 541                 switch (code) {
 542                 case ICMP6_TIME_EXCEED_TRANSIT:
 543                         code = PRC_TIMXCEED_INTRANS;
 544                         break;
 545                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 546                         code = PRC_TIMXCEED_REASS;
 547                         break;
 548                 default:
 549                         goto badcode;
 550                 }
 551                 goto deliver;
 552                 break;
 553
 554         case ICMP6_PARAM_PROB:
 555                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 556                 switch (code) {
 557                 case ICMP6_PARAMPROB_NEXTHEADER:
 558                         code = PRC_UNREACH_PROTOCOL;
 559                         break;
 560                 case ICMP6_PARAMPROB_HEADER:
 561                 case ICMP6_PARAMPROB_OPTION:
 562                         code = PRC_PARAMPROB;
 563                         break;
 564                 default:
 565                         goto badcode;
 566                 }
 567                 goto deliver;
 568                 break;
 569
 570         case ICMP6_ECHO_REQUEST:
 571                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 572                 if (code != 0)
 573                         goto badcode;
 574                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 575                         /* Give up remote */
 576                         break;
 577                 }
 578                 if ((n->m_flags & M_EXT) != 0
 579                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 580                         struct mbuf *n0 = n;
 581                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 582                         int n0len;
 583
 584                         MGETHDR(n, M_DONTWAIT, n0->m_type);
 585                         n0len = n0->m_pkthdr.len;       /* save for use below */
 586                         if (n)
 587                                 M_MOVE_PKTHDR(n, n0);   /* FIB copied. */
 588                         if (n && maxlen >= MHLEN) {
 589                                 MCLGET(n, M_DONTWAIT);
 590                                 if ((n->m_flags & M_EXT) == 0) {
 591                                         m_free(n);
 592                                         n = NULL;
 593                                 }
 594                         }
 595                         if (n == NULL) {
 596                                 /* Give up remote */
 597                                 m_freem(n0);
 598                                 break;
 599                         }
 600                         /*
 601                          * Copy IPv6 and ICMPv6 only.
 602                          */
 603                         nip6 = mtod(n, struct ip6_hdr *);
 604                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 605                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 606                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 607                         noff = sizeof(struct ip6_hdr);
 608                         /* new mbuf contains only ipv6+icmpv6 headers */
 609                         n->m_len = noff + sizeof(struct icmp6_hdr);
 610                         /*
 611                          * Adjust mbuf.  ip6_plen will be adjusted in
 612                          * ip6_output().
 613                          */
 614                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 615                         /* recalculate complete packet size */
 616                         n->m_pkthdr.len = n0len + (noff - off);
 617                         n->m_next = n0;
 618                 } else {
 619                         nip6 = mtod(n, struct ip6_hdr *);
 620                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 621                             sizeof(*nicmp6));
 622                         noff = off;
 623                 }
 624                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 625                 nicmp6->icmp6_code = 0;
 626                 if (n) {
 627                         ICMP6STAT_INC(icp6s_reflect);
 628                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 629                         icmp6_reflect(n, noff);
 630                 }
 631                 break;
 632
 633         case ICMP6_ECHO_REPLY:
 634                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 635                 if (code != 0)
 636                         goto badcode;
 637                 break;
 638
 639         case MLD_LISTENER_QUERY:
 640         case MLD_LISTENER_REPORT:
 641         case MLD_LISTENER_DONE:
 642         case MLDV2_LISTENER_REPORT:
 643                 /*
 644                  * Drop MLD traffic which is not link-local, has a hop limit
 645                  * of greater than 1 hop, or which does not have the
 646                  * IPv6 HBH Router Alert option.
 647                  * As IPv6 HBH options are stripped in ip6_input() we must
 648                  * check an mbuf header flag.
 649                  * XXX Should we also sanity check that these messages
 650                  * were directed to a link-local multicast prefix?
 651                  */
 652                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 653                         goto freeit;
 654                 if (mld_input(m, off, icmp6len) != 0)
 655                         return (IPPROTO_DONE);
 656                 /* m stays. */
 657                 break;
 658
 659         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 660             {
 661                 enum { WRU, FQDN } mode;
 662
 663                 if (!V_icmp6_nodeinfo)
 664                         break;
 665
 666                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 667                         mode = WRU;
 668                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 669                         mode = FQDN;
 670                 else
 671                         goto badlen;
 672
 673                 if (mode == FQDN) {
 674 #ifndef PULLDOWN_TEST
 675                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 676                             IPPROTO_DONE);
 677 #endif
 678                         n = m_copy(m, 0, M_COPYALL);
 679                         if (n)
 680                                 n = ni6_input(n, off);
 681                         /* XXX meaningless if n == NULL */
 682                         noff = sizeof(struct ip6_hdr);
 683                 } else {
 684                         struct prison *pr;
 685                         u_char *p;
 686                         int maxlen, maxhlen, hlen;
 687
 688                         /*
 689                          * XXX: this combination of flags is pointless,
 690                          * but should we keep this for compatibility?
 691                          */
 692                         if ((V_icmp6_nodeinfo & 5) != 5)
 693                                 break;
 694
 695                         if (code != 0)
 696                                 goto badcode;
 697                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 698                         if (maxlen >= MCLBYTES) {
 699                                 /* Give up remote */
 700                                 break;
 701                         }
 702                         MGETHDR(n, M_DONTWAIT, m->m_type);
 703                         if (n && maxlen > MHLEN) {
 704                                 MCLGET(n, M_DONTWAIT);
 705                                 if ((n->m_flags & M_EXT) == 0) {
 706                                         m_free(n);
 707                                         n = NULL;
 708                                 }
 709                         }
 710                         if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
 711                                 /*
 712                                  * Previous code did a blind M_COPY_PKTHDR
 713                                  * and said "just for rcvif".  If true, then
 714                                  * we could tolerate the dup failing (due to
 715                                  * the deep copy of the tag chain).  For now
 716                                  * be conservative and just fail.
 717                                  */
 718                                 m_free(n);
 719                                 n = NULL;
 720                         }
 721                         if (n == NULL) {
 722                                 /* Give up remote */
 723                                 break;
 724                         }
 725                         n->m_pkthdr.rcvif = NULL;
 726                         n->m_len = 0;
 727                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 728                         pr = curthread->td_ucred->cr_prison;
 729                         mtx_lock(&pr->pr_mtx);
 730                         hlen = strlen(pr->pr_hostname);
 731                         if (maxhlen > hlen)
 732                                 maxhlen = hlen;
 733                         /*
 734                          * Copy IPv6 and ICMPv6 only.
 735                          */
 736                         nip6 = mtod(n, struct ip6_hdr *);
 737                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 738                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 739                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 740                         p = (u_char *)(nicmp6 + 1);
 741                         bzero(p, 4);
 742                         /* meaningless TTL */
 743                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 744                         mtx_unlock(&pr->pr_mtx);
 745                         noff = sizeof(struct ip6_hdr);
 746                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 747                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 748                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 749                         nicmp6->icmp6_code = 0;
 750                 }
 751                 if (n) {
 752                         ICMP6STAT_INC(icp6s_reflect);
 753                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 754                         icmp6_reflect(n, noff);
 755                 }
 756                 break;
 757             }
 758
 759         case ICMP6_WRUREPLY:
 760                 if (code != 0)
 761                         goto badcode;
 762                 break;
 763
 764         case ND_ROUTER_SOLICIT:
 765                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 766                 if (code != 0)
 767                         goto badcode;
 768                 if (icmp6len < sizeof(struct nd_router_solicit))
 769                         goto badlen;
 770                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 771                         /* give up local */
 772
 773                         /* Send incoming SeND packet to user space. */
 774                         if (send_sendso_input_hook != NULL) {
 775                                 IP6_EXTHDR_CHECK(m, off,
 776                                     icmp6len, IPPROTO_DONE);
 777                                 error = send_sendso_input_hook(m, ifp,
 778                                     SND_IN, ip6len);
 779                                 /* -1 == no app on SEND socket */
 780                                 if (error == 0)
 781                                         return (IPPROTO_DONE);
 782                                 nd6_rs_input(m, off, icmp6len);
 783                         } else
 784                                 nd6_rs_input(m, off, icmp6len);
 785                         m = NULL;
 786                         goto freeit;
 787                 }
 788                 if (send_sendso_input_hook != NULL) {
 789                         IP6_EXTHDR_CHECK(n, off,
 790                             icmp6len, IPPROTO_DONE);
 791                         error = send_sendso_input_hook(n, ifp,
 792                             SND_IN, ip6len);
 793                         if (error == 0)
 794                                 goto freeit;
 795                         /* -1 == no app on SEND socket */
 796                         nd6_rs_input(n, off, icmp6len);
 797                 } else
 798                         nd6_rs_input(n, off, icmp6len);
 799                 /* m stays. */
 800                 break;
 801
 802         case ND_ROUTER_ADVERT:
 803                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 804                 if (code != 0)
 805                         goto badcode;
 806                 if (icmp6len < sizeof(struct nd_router_advert))
 807                         goto badlen;
 808                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 809
 810                         /* Send incoming SeND-protected/ND packet to user space. */
 811                         if (send_sendso_input_hook != NULL) {
 812                                 error = send_sendso_input_hook(m, ifp,
 813                                     SND_IN, ip6len);
 814                                 if (error == 0)
 815                                         return (IPPROTO_DONE);
 816                                 nd6_ra_input(m, off, icmp6len);
 817                         } else
 818                                 nd6_ra_input(m, off, icmp6len);
 819                         m = NULL;
 820                         goto freeit;
 821                 }
 822                 if (send_sendso_input_hook != NULL) {
 823                         error = send_sendso_input_hook(n, ifp,
 824                             SND_IN, ip6len);
 825                         if (error == 0)
 826                                 goto freeit;
 827                         nd6_ra_input(n, off, icmp6len);
 828                 } else
 829                         nd6_ra_input(n, off, icmp6len);
 830                 /* m stays. */
 831                 break;
 832
 833         case ND_NEIGHBOR_SOLICIT:
 834                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 835                 if (code != 0)
 836                         goto badcode;
 837                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 838                         goto badlen;
 839                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 840                         if (send_sendso_input_hook != NULL) {
 841                                 error = send_sendso_input_hook(m, ifp,
 842                                     SND_IN, ip6len);
 843                                 if (error == 0)
 844                                         return (IPPROTO_DONE);
 845                                 nd6_ns_input(m, off, icmp6len);
 846                         } else
 847                                 nd6_ns_input(m, off, icmp6len);
 848                         m = NULL;
 849                         goto freeit;
 850                 }
 851                 if (send_sendso_input_hook != NULL) {
 852                         error = send_sendso_input_hook(n, ifp,
 853                             SND_IN, ip6len);
 854                         if (error == 0)
 855                                 goto freeit;
 856                         nd6_ns_input(n, off, icmp6len);
 857                 } else
 858                         nd6_ns_input(n, off, icmp6len);
 859                 /* m stays. */
 860                 break;
 861
 862         case ND_NEIGHBOR_ADVERT:
 863                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 864                 if (code != 0)
 865                         goto badcode;
 866                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 867                         goto badlen;
 868                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 869
 870                         /* Send incoming SeND-protected/ND packet to user space. */
 871                         if (send_sendso_input_hook != NULL) {
 872                                 error = send_sendso_input_hook(m, ifp,
 873                                     SND_IN, ip6len);
 874                                 if (error == 0)
 875                                         return (IPPROTO_DONE);
 876                                 nd6_na_input(m, off, icmp6len);
 877                         } else
 878                                 nd6_na_input(m, off, icmp6len);
 879                         m = NULL;
 880                         goto freeit;
 881                 }
 882                 if (send_sendso_input_hook != NULL) {
 883                         error = send_sendso_input_hook(n, ifp,
 884                             SND_IN, ip6len);
 885                         if (error == 0)
 886                                 goto freeit;
 887                         nd6_na_input(n, off, icmp6len);
 888                 } else
 889                         nd6_na_input(n, off, icmp6len);
 890                 /* m stays. */
 891                 break;
 892
 893         case ND_REDIRECT:
 894                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 895                 if (code != 0)
 896                         goto badcode;
 897                 if (icmp6len < sizeof(struct nd_redirect))
 898                         goto badlen;
 899                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 900                         if (send_sendso_input_hook != NULL) {
 901                                 error = send_sendso_input_hook(m, ifp,
 902                                     SND_IN, ip6len);
 903                                 if (error == 0)
 904                                         return (IPPROTO_DONE);
 905                             icmp6_redirect_input(m, off);
 906                         } else
 907                                 icmp6_redirect_input(m, off);
 908                         m = NULL;
 909                         goto freeit;
 910                 }
 911                 if (send_sendso_input_hook != NULL) {
 912                         error = send_sendso_input_hook(n, ifp,
 913                             SND_IN, ip6len);
 914                         if (error == 0)
 915                                 goto freeit;
 916                         icmp6_redirect_input(n, off);
 917                 } else
 918                         icmp6_redirect_input(n, off);
 919                 /* m stays. */
 920                 break;
 921
 922         case ICMP6_ROUTER_RENUMBERING:
 923                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 924                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 925                         goto badcode;
 926                 if (icmp6len < sizeof(struct icmp6_router_renum))
 927                         goto badlen;
 928                 break;
 929
 930         default:
 931                 nd6log((LOG_DEBUG,
 932                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 933                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 934                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 935                     ifp ? ifp->if_index : 0));
 936                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 937                         /* ICMPv6 error: MUST deliver it by spec... */
 938                         code = PRC_NCMDS;
 939                         /* deliver */
 940                 } else {
 941                         /* ICMPv6 informational: MUST not deliver */
 942                         break;
 943                 }
 944         deliver:
 945                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 946                         /* In this case, m should've been freed. */
 947                         return (IPPROTO_DONE);
 948                 }
 949                 break;
 950
 951         badcode:
 952                 ICMP6STAT_INC(icp6s_badcode);
 953                 break;
 954
 955         badlen:
 956                 ICMP6STAT_INC(icp6s_badlen);
 957                 break;
 958         }
 959
 960         /* deliver the packet to appropriate sockets */
 961         icmp6_rip6_input(&m, *offp);
 962
 963         return IPPROTO_DONE;
 964
 965  freeit:
 966         m_freem(m);
 967         return IPPROTO_DONE;
 968 }
 969
 970 static int
 971 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 972 {
 973         struct mbuf *m = *mp;
 974         struct icmp6_hdr *icmp6;
 975         struct ip6_hdr *eip6;
 976         u_int32_t notifymtu;
 977         struct sockaddr_in6 icmp6src, icmp6dst;
 978
 979         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 980                 ICMP6STAT_INC(icp6s_tooshort);
 981                 goto freeit;
 982         }
 983 #ifndef PULLDOWN_TEST
 984         IP6_EXTHDR_CHECK(m, off,
 985             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 986         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 987 #else
 988         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 989             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 990         if (icmp6 == NULL) {
 991                 ICMP6STAT_INC(icp6s_tooshort);
 992                 return (-1);
 993         }
 994 #endif
 995         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 996
 997         /* Detect the upper level protocol */
 998         {
 999                 void (*ctlfunc)(int, struct sockaddr *, void *);
1000                 u_int8_t nxt = eip6->ip6_nxt;
1001                 int eoff = off + sizeof(struct icmp6_hdr) +
1002                     sizeof(struct ip6_hdr);
1003                 struct ip6ctlparam ip6cp;
1004                 struct in6_addr *finaldst = NULL;
1005                 int icmp6type = icmp6->icmp6_type;
1006                 struct ip6_frag *fh;
1007                 struct ip6_rthdr *rth;
1008                 struct ip6_rthdr0 *rth0;
1009                 int rthlen;
1010
1011                 while (1) { /* XXX: should avoid infinite loop explicitly? */
1012                         struct ip6_ext *eh;
1013
1014                         switch (nxt) {
1015                         case IPPROTO_HOPOPTS:
1016                         case IPPROTO_DSTOPTS:
1017                         case IPPROTO_AH:
1018 #ifndef PULLDOWN_TEST
1019                                 IP6_EXTHDR_CHECK(m, 0,
1020                                     eoff + sizeof(struct ip6_ext), -1);
1021                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
1022 #else
1023                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
1024                                     eoff, sizeof(*eh));
1025                                 if (eh == NULL) {
1026                                         ICMP6STAT_INC(icp6s_tooshort);
1027                                         return (-1);
1028                                 }
1029 #endif
1030
1031                                 if (nxt == IPPROTO_AH)
1032                                         eoff += (eh->ip6e_len + 2) << 2;
1033                                 else
1034                                         eoff += (eh->ip6e_len + 1) << 3;
1035                                 nxt = eh->ip6e_nxt;
1036                                 break;
1037                         case IPPROTO_ROUTING:
1038                                 /*
1039                                  * When the erroneous packet contains a
1040                                  * routing header, we should examine the
1041                                  * header to determine the final destination.
1042                                  * Otherwise, we can't properly update
1043                                  * information that depends on the final
1044                                  * destination (e.g. path MTU).
1045                                  */
1046 #ifndef PULLDOWN_TEST
1047                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1048                                 rth = (struct ip6_rthdr *)
1049                                     (mtod(m, caddr_t) + eoff);
1050 #else
1051                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1052                                     eoff, sizeof(*rth));
1053                                 if (rth == NULL) {
1054                                         ICMP6STAT_INC(icp6s_tooshort);
1055                                         return (-1);
1056                                 }
1057 #endif
1058                                 rthlen = (rth->ip6r_len + 1) << 3;
1059                                 /*
1060                                  * XXX: currently there is no
1061                                  * officially defined type other
1062                                  * than type-0.
1063                                  * Note that if the segment left field
1064                                  * is 0, all intermediate hops must
1065                                  * have been passed.
1066                                  */
1067                                 if (rth->ip6r_segleft &&
1068                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1069                                         int hops;
1070
1071 #ifndef PULLDOWN_TEST
1072                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1073                                         rth0 = (struct ip6_rthdr0 *)
1074                                             (mtod(m, caddr_t) + eoff);
1075 #else
1076                                         IP6_EXTHDR_GET(rth0,
1077                                             struct ip6_rthdr0 *, m,
1078                                             eoff, rthlen);
1079                                         if (rth0 == NULL) {
1080                                                 ICMP6STAT_INC(icp6s_tooshort);
1081                                                 return (-1);
1082                                         }
1083 #endif
1084                                         /* just ignore a bogus header */
1085                                         if ((rth0->ip6r0_len % 2) == 0 &&
1086                                             (hops = rth0->ip6r0_len/2))
1087                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1088                                 }
1089                                 eoff += rthlen;
1090                                 nxt = rth->ip6r_nxt;
1091                                 break;
1092                         case IPPROTO_FRAGMENT:
1093 #ifndef PULLDOWN_TEST
1094                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1095                                     sizeof(struct ip6_frag), -1);
1096                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1097                                     eoff);
1098 #else
1099                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1100                                     eoff, sizeof(*fh));
1101                                 if (fh == NULL) {
1102                                         ICMP6STAT_INC(icp6s_tooshort);
1103                                         return (-1);
1104                                 }
1105 #endif
1106                                 /*
1107                                  * Data after a fragment header is meaningless
1108                                  * unless it is the first fragment, but
1109                                  * we'll go to the notify label for path MTU
1110                                  * discovery.
1111                                  */
1112                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1113                                         goto notify;
1114
1115                                 eoff += sizeof(struct ip6_frag);
1116                                 nxt = fh->ip6f_nxt;
1117                                 break;
1118                         default:
1119                                 /*
1120                                  * This case includes ESP and the No Next
1121                                  * Header.  In such cases going to the notify
1122                                  * label does not have any meaning
1123                                  * (i.e. ctlfunc will be NULL), but we go
1124                                  * anyway since we might have to update
1125                                  * path MTU information.
1126                                  */
1127                                 goto notify;
1128                         }
1129                 }
1130           notify:
1131 #ifndef PULLDOWN_TEST
1132                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1133 #else
1134                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1135                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1136                 if (icmp6 == NULL) {
1137                         ICMP6STAT_INC(icp6s_tooshort);
1138                         return (-1);
1139                 }
1140 #endif
1141
1142                 /*
1143                  * retrieve parameters from the inner IPv6 header, and convert
1144                  * them into sockaddr structures.
1145                  * XXX: there is no guarantee that the source or destination
1146                  * addresses of the inner packet are in the same scope as
1147                  * the addresses of the icmp packet.  But there is no other
1148                  * way to determine the zone.
1149                  */
1150                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1151
1152                 bzero(&icmp6dst, sizeof(icmp6dst));
1153                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1154                 icmp6dst.sin6_family = AF_INET6;
1155                 if (finaldst == NULL)
1156                         icmp6dst.sin6_addr = eip6->ip6_dst;
1157                 else
1158                         icmp6dst.sin6_addr = *finaldst;
1159                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1160                         goto freeit;
1161                 bzero(&icmp6src, sizeof(icmp6src));
1162                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1163                 icmp6src.sin6_family = AF_INET6;
1164                 icmp6src.sin6_addr = eip6->ip6_src;
1165                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1166                         goto freeit;
1167                 icmp6src.sin6_flowinfo =
1168                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1169
1170                 if (finaldst == NULL)
1171                         finaldst = &eip6->ip6_dst;
1172                 ip6cp.ip6c_m = m;
1173                 ip6cp.ip6c_icmp6 = icmp6;
1174                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1175                 ip6cp.ip6c_off = eoff;
1176                 ip6cp.ip6c_finaldst = finaldst;
1177                 ip6cp.ip6c_src = &icmp6src;
1178                 ip6cp.ip6c_nxt = nxt;
1179
1180                 m_addr_changed(m);
1181
1182                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1183                         notifymtu = ntohl(icmp6->icmp6_mtu);
1184                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1185                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1186                 }
1187
1188                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1189                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1190                 if (ctlfunc) {
1191                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1192                             &ip6cp);
1193                 }
1194         }
1195         *mp = m;
1196         return (0);
1197
1198   freeit:
1199         m_freem(m);
1200         return (-1);
1201 }
1202
1203 void
1204 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1205 {
1206         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1207         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1208         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1209         u_int mtu = ntohl(icmp6->icmp6_mtu);
1210         struct in_conninfo inc;
1211
1212 #if 0
1213         /*
1214          * RFC2460 section 5, last paragraph.
1215          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1216          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1217          * due to packet translator in the middle.
1218          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1219          * special handling.
1220          */
1221         if (mtu < IPV6_MMTU)
1222                 return;
1223 #endif
1224
1225         /*
1226          * we reject ICMPv6 too big with abnormally small value.
1227          * XXX what is the good definition of "abnormally small"?
1228          */
1229         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1230                 return;
1231
1232         if (!validated)
1233                 return;
1234
1235         /*
1236          * In case the suggested mtu is less than IPV6_MMTU, we
1237          * only need to remember that it was for above mentioned
1238          * "alwaysfrag" case.
1239          * Try to be as close to the spec as possible.
1240          */
1241         if (mtu < IPV6_MMTU)
1242                 mtu = IPV6_MMTU - 8;
1243
1244         bzero(&inc, sizeof(inc));
1245         inc.inc_fibnum = M_GETFIB(m);
1246         inc.inc_flags |= INC_ISIPV6;
1247         inc.inc6_faddr = *dst;
1248         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1249                 return;
1250
1251         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1252                 tcp_hc_updatemtu(&inc, mtu);
1253                 ICMP6STAT_INC(icp6s_pmtuchg);
1254         }
1255 }
1256
1257 /*
1258  * Process a Node Information Query packet, based on
1259  * draft-ietf-ipngwg-icmp-name-lookups-07.
1260  *
1261  * Spec incompatibilities:
1262  * - IPv6 Subject address handling
1263  * - IPv4 Subject address handling support missing
1264  * - Proxy reply (answer even if it's not for me)
1265  * - joins NI group address at in6_ifattach() time only, does not cope
1266  *   with hostname changes by sethostname(3)
1267  */
1268 static struct mbuf *
1269 ni6_input(struct mbuf *m, int off)
1270 {
1271         struct icmp6_nodeinfo *ni6, *nni6;
1272         struct mbuf *n = NULL;
1273         struct prison *pr;
1274         u_int16_t qtype;
1275         int subjlen;
1276         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1277         struct ni_reply_fqdn *fqdn;
1278         int addrs;              /* for NI_QTYPE_NODEADDR */
1279         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1280         struct in6_addr in6_subj; /* subject address */
1281         struct ip6_hdr *ip6;
1282         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1283         char *subj = NULL;
1284         struct in6_ifaddr *ia6 = NULL;
1285
1286         ip6 = mtod(m, struct ip6_hdr *);
1287 #ifndef PULLDOWN_TEST
1288         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1289 #else
1290         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1291         if (ni6 == NULL) {
1292                 /* m is already reclaimed */
1293                 return (NULL);
1294         }
1295 #endif
1296
1297         /*
1298          * Validate IPv6 source address.
1299          * The default configuration MUST be to refuse answering queries from
1300          * global-scope addresses according to RFC4602.
1301          * Notes:
1302          *  - it's not very clear what "refuse" means; this implementation
1303          *    simply drops it.
1304          *  - it's not very easy to identify global-scope (unicast) addresses
1305          *    since there are many prefixes for them.  It should be safer
1306          *    and in practice sufficient to check "all" but loopback and
1307          *    link-local (note that site-local unicast was deprecated and
1308          *    ULA is defined as global scope-wise)
1309          */
1310         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1311             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1312             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1313                 goto bad;
1314
1315         /*
1316          * Validate IPv6 destination address.
1317          *
1318          * The Responder must discard the Query without further processing
1319          * unless it is one of the Responder's unicast or anycast addresses, or
1320          * a link-local scope multicast address which the Responder has joined.
1321          * [RFC4602, Section 5.]
1322          */
1323         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1324                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1325                         goto bad;
1326                 /* else it's a link-local multicast, fine */
1327         } else {                /* unicast or anycast */
1328                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1329                         goto bad; /* XXX impossible */
1330
1331                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1332                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1333                         ifa_free(&ia6->ia_ifa);
1334                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1335                                 "a temporary address in %s:%d",
1336                                __FILE__, __LINE__));
1337                         goto bad;
1338                 }
1339                 ifa_free(&ia6->ia_ifa);
1340         }
1341
1342         /* validate query Subject field. */
1343         qtype = ntohs(ni6->ni_qtype);
1344         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1345         switch (qtype) {
1346         case NI_QTYPE_NOOP:
1347         case NI_QTYPE_SUPTYPES:
1348                 /* 07 draft */
1349                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1350                         break;
1351                 /* FALLTHROUGH */
1352         case NI_QTYPE_FQDN:
1353         case NI_QTYPE_NODEADDR:
1354         case NI_QTYPE_IPV4ADDR:
1355                 switch (ni6->ni_code) {
1356                 case ICMP6_NI_SUBJ_IPV6:
1357 #if ICMP6_NI_SUBJ_IPV6 != 0
1358                 case 0:
1359 #endif
1360                         /*
1361                          * backward compatibility - try to accept 03 draft
1362                          * format, where no Subject is present.
1363                          */
1364                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1365                             subjlen == 0) {
1366                                 oldfqdn++;
1367                                 break;
1368                         }
1369 #if ICMP6_NI_SUBJ_IPV6 != 0
1370                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1371                                 goto bad;
1372 #endif
1373
1374                         if (subjlen != sizeof(struct in6_addr))
1375                                 goto bad;
1376
1377                         /*
1378                          * Validate Subject address.
1379                          *
1380                          * Not sure what exactly "address belongs to the node"
1381                          * means in the spec, is it just unicast, or what?
1382                          *
1383                          * At this moment we consider Subject address as
1384                          * "belong to the node" if the Subject address equals
1385                          * to the IPv6 destination address; validation for
1386                          * IPv6 destination address should have done enough
1387                          * check for us.
1388                          *
1389                          * We do not do proxy at this moment.
1390                          */
1391                         /* m_pulldown instead of copy? */
1392                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1393                             subjlen, (caddr_t)&in6_subj);
1394                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1395                                 goto bad;
1396
1397                         subj = (char *)&in6_subj;
1398                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1399                                 break;
1400
1401                         /*
1402                          * XXX if we are to allow other cases, we should really
1403                          * be careful about scope here.
1404                          * basically, we should disallow queries toward IPv6
1405                          * destination X with subject Y,
1406                          * if scope(X) > scope(Y).
1407                          * if we allow scope(X) > scope(Y), it will result in
1408                          * information leakage across scope boundary.
1409                          */
1410                         goto bad;
1411
1412                 case ICMP6_NI_SUBJ_FQDN:
1413                         /*
1414                          * Validate Subject name with gethostname(3).
1415                          *
1416                          * The behavior may need some debate, since:
1417                          * - we are not sure if the node has FQDN as
1418                          *   hostname (returned by gethostname(3)).
1419                          * - the code does wildcard match for truncated names.
1420                          *   however, we are not sure if we want to perform
1421                          *   wildcard match, if gethostname(3) side has
1422                          *   truncated hostname.
1423                          */
1424                         pr = curthread->td_ucred->cr_prison;
1425                         mtx_lock(&pr->pr_mtx);
1426                         n = ni6_nametodns(pr->pr_hostname,
1427                             strlen(pr->pr_hostname), 0);
1428                         mtx_unlock(&pr->pr_mtx);
1429                         if (!n || n->m_next || n->m_len == 0)
1430                                 goto bad;
1431                         IP6_EXTHDR_GET(subj, char *, m,
1432                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1433                         if (subj == NULL)
1434                                 goto bad;
1435                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1436                             n->m_len)) {
1437                                 goto bad;
1438                         }
1439                         m_freem(n);
1440                         n = NULL;
1441                         break;
1442
1443                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1444                 default:
1445                         goto bad;
1446                 }
1447                 break;
1448         }
1449
1450         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1451         switch (qtype) {
1452         case NI_QTYPE_FQDN:
1453                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1454                         goto bad;
1455                 break;
1456         case NI_QTYPE_NODEADDR:
1457         case NI_QTYPE_IPV4ADDR:
1458                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1459                         goto bad;
1460                 break;
1461         }
1462
1463         /* guess reply length */
1464         switch (qtype) {
1465         case NI_QTYPE_NOOP:
1466                 break;          /* no reply data */
1467         case NI_QTYPE_SUPTYPES:
1468                 replylen += sizeof(u_int32_t);
1469                 break;
1470         case NI_QTYPE_FQDN:
1471                 /* XXX will append an mbuf */
1472                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1473                 break;
1474         case NI_QTYPE_NODEADDR:
1475                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1476                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1477                     sizeof(u_int32_t))) > MCLBYTES)
1478                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1479                 break;
1480         case NI_QTYPE_IPV4ADDR:
1481                 /* unsupported - should respond with unknown Qtype? */
1482                 break;
1483         default:
1484                 /*
1485                  * XXX: We must return a reply with the ICMP6 code
1486                  * `unknown Qtype' in this case.  However we regard the case
1487                  * as an FQDN query for backward compatibility.
1488                  * Older versions set a random value to this field,
1489                  * so it rarely varies in the defined qtypes.
1490                  * But the mechanism is not reliable...
1491                  * maybe we should obsolete older versions.
1492                  */
1493                 qtype = NI_QTYPE_FQDN;
1494                 /* XXX will append an mbuf */
1495                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1496                 oldfqdn++;
1497                 break;
1498         }
1499
1500         /* allocate an mbuf to reply. */
1501         MGETHDR(n, M_DONTWAIT, m->m_type);
1502         if (n == NULL) {
1503                 m_freem(m);
1504                 return (NULL);
1505         }
1506         M_MOVE_PKTHDR(n, m); /* just for recvif and FIB */
1507         if (replylen > MHLEN) {
1508                 if (replylen > MCLBYTES) {
1509                         /*
1510                          * XXX: should we try to allocate more? But MCLBYTES
1511                          * is probably much larger than IPV6_MMTU...
1512                          */
1513                         goto bad;
1514                 }
1515                 MCLGET(n, M_DONTWAIT);
1516                 if ((n->m_flags & M_EXT) == 0) {
1517                         goto bad;
1518                 }
1519         }
1520         n->m_pkthdr.len = n->m_len = replylen;
1521
1522         /* copy mbuf header and IPv6 + Node Information base headers */
1523         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1524         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1525         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1526
1527         /* qtype dependent procedure */
1528         switch (qtype) {
1529         case NI_QTYPE_NOOP:
1530                 nni6->ni_code = ICMP6_NI_SUCCESS;
1531                 nni6->ni_flags = 0;
1532                 break;
1533         case NI_QTYPE_SUPTYPES:
1534         {
1535                 u_int32_t v;
1536                 nni6->ni_code = ICMP6_NI_SUCCESS;
1537                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1538                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1539                 v = (u_int32_t)htonl(0x0000000f);
1540                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1541                 break;
1542         }
1543         case NI_QTYPE_FQDN:
1544                 nni6->ni_code = ICMP6_NI_SUCCESS;
1545                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1546                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1547                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1548                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1549                 /*
1550                  * XXX do we really have FQDN in hostname?
1551                  */
1552                 pr = curthread->td_ucred->cr_prison;
1553                 mtx_lock(&pr->pr_mtx);
1554                 n->m_next = ni6_nametodns(pr->pr_hostname,
1555                     strlen(pr->pr_hostname), oldfqdn);
1556                 mtx_unlock(&pr->pr_mtx);
1557                 if (n->m_next == NULL)
1558                         goto bad;
1559                 /* XXX we assume that n->m_next is not a chain */
1560                 if (n->m_next->m_next != NULL)
1561                         goto bad;
1562                 n->m_pkthdr.len += n->m_next->m_len;
1563                 break;
1564         case NI_QTYPE_NODEADDR:
1565         {
1566                 int lenlim, copied;
1567
1568                 nni6->ni_code = ICMP6_NI_SUCCESS;
1569                 n->m_pkthdr.len = n->m_len =
1570                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1571                 lenlim = M_TRAILINGSPACE(n);
1572                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1573                 /* XXX: reset mbuf length */
1574                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1575                     sizeof(struct icmp6_nodeinfo) + copied;
1576                 break;
1577         }
1578         default:
1579                 break;          /* XXX impossible! */
1580         }
1581
1582         nni6->ni_type = ICMP6_NI_REPLY;
1583         m_freem(m);
1584         return (n);
1585
1586   bad:
1587         m_freem(m);
1588         if (n)
1589                 m_freem(n);
1590         return (NULL);
1591 }
1592
1593 /*
1594  * make a mbuf with DNS-encoded string.  no compression support.
1595  *
1596  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1597  * treated as truncated name (two \0 at the end).  this is a wild guess.
1598  *
1599  * old - return pascal string if non-zero
1600  */
1601 static struct mbuf *
1602 ni6_nametodns(const char *name, int namelen, int old)
1603 {
1604         struct mbuf *m;
1605         char *cp, *ep;
1606         const char *p, *q;
1607         int i, len, nterm;
1608
1609         if (old)
1610                 len = namelen + 1;
1611         else
1612                 len = MCLBYTES;
1613
1614         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1615         MGET(m, M_DONTWAIT, MT_DATA);
1616         if (m && len > MLEN) {
1617                 MCLGET(m, M_DONTWAIT);
1618                 if ((m->m_flags & M_EXT) == 0)
1619                         goto fail;
1620         }
1621         if (!m)
1622                 goto fail;
1623         m->m_next = NULL;
1624
1625         if (old) {
1626                 m->m_len = len;
1627                 *mtod(m, char *) = namelen;
1628                 bcopy(name, mtod(m, char *) + 1, namelen);
1629                 return m;
1630         } else {
1631                 m->m_len = 0;
1632                 cp = mtod(m, char *);
1633                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1634
1635                 /* if not certain about my name, return empty buffer */
1636                 if (namelen == 0)
1637                         return m;
1638
1639                 /*
1640                  * guess if it looks like shortened hostname, or FQDN.
1641                  * shortened hostname needs two trailing "\0".
1642                  */
1643                 i = 0;
1644                 for (p = name; p < name + namelen; p++) {
1645                         if (*p && *p == '.')
1646                                 i++;
1647                 }
1648                 if (i < 2)
1649                         nterm = 2;
1650                 else
1651                         nterm = 1;
1652
1653                 p = name;
1654                 while (cp < ep && p < name + namelen) {
1655                         i = 0;
1656                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1657                                 i++;
1658                         /* result does not fit into mbuf */
1659                         if (cp + i + 1 >= ep)
1660                                 goto fail;
1661                         /*
1662                          * DNS label length restriction, RFC1035 page 8.
1663                          * "i == 0" case is included here to avoid returning
1664                          * 0-length label on "foo..bar".
1665                          */
1666                         if (i <= 0 || i >= 64)
1667                                 goto fail;
1668                         *cp++ = i;
1669                         bcopy(p, cp, i);
1670                         cp += i;
1671                         p = q;
1672                         if (p < name + namelen && *p == '.')
1673                                 p++;
1674                 }
1675                 /* termination */
1676                 if (cp + nterm >= ep)
1677                         goto fail;
1678                 while (nterm-- > 0)
1679                         *cp++ = '\0';
1680                 m->m_len = cp - mtod(m, char *);
1681                 return m;
1682         }
1683
1684         panic("should not reach here");
1685         /* NOTREACHED */
1686
1687  fail:
1688         if (m)
1689                 m_freem(m);
1690         return NULL;
1691 }
1692
1693 /*
1694  * check if two DNS-encoded string matches.  takes care of truncated
1695  * form (with \0\0 at the end).  no compression support.
1696  * XXX upper/lowercase match (see RFC2065)
1697  */
1698 static int
1699 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1700 {
1701         const char *a0, *b0;
1702         int l;
1703
1704         /* simplest case - need validation? */
1705         if (alen == blen && bcmp(a, b, alen) == 0)
1706                 return 1;
1707
1708         a0 = a;
1709         b0 = b;
1710
1711         /* termination is mandatory */
1712         if (alen < 2 || blen < 2)
1713                 return 0;
1714         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1715                 return 0;
1716         alen--;
1717         blen--;
1718
1719         while (a - a0 < alen && b - b0 < blen) {
1720                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1721                         return 0;
1722
1723                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1724                         return 0;
1725                 /* we don't support compression yet */
1726                 if (a[0] >= 64 || b[0] >= 64)
1727                         return 0;
1728
1729                 /* truncated case */
1730                 if (a[0] == 0 && a - a0 == alen - 1)
1731                         return 1;
1732                 if (b[0] == 0 && b - b0 == blen - 1)
1733                         return 1;
1734                 if (a[0] == 0 || b[0] == 0)
1735                         return 0;
1736
1737                 if (a[0] != b[0])
1738                         return 0;
1739                 l = a[0];
1740                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1741                         return 0;
1742                 if (bcmp(a + 1, b + 1, l) != 0)
1743                         return 0;
1744
1745                 a += 1 + l;
1746                 b += 1 + l;
1747         }
1748
1749         if (a - a0 == alen && b - b0 == blen)
1750                 return 1;
1751         else
1752                 return 0;
1753 }
1754
1755 /*
1756  * calculate the number of addresses to be returned in the node info reply.
1757  */
1758 static int
1759 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1760     struct in6_addr *subj)
1761 {
1762         struct ifnet *ifp;
1763         struct in6_ifaddr *ifa6;
1764         struct ifaddr *ifa;
1765         int addrs = 0, addrsofif, iffound = 0;
1766         int niflags = ni6->ni_flags;
1767
1768         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1769                 switch (ni6->ni_code) {
1770                 case ICMP6_NI_SUBJ_IPV6:
1771                         if (subj == NULL) /* must be impossible... */
1772                                 return (0);
1773                         break;
1774                 default:
1775                         /*
1776                          * XXX: we only support IPv6 subject address for
1777                          * this Qtype.
1778                          */
1779                         return (0);
1780                 }
1781         }
1782
1783         IFNET_RLOCK_NOSLEEP();
1784         TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
1785                 addrsofif = 0;
1786                 IF_ADDR_RLOCK(ifp);
1787                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1788                         if (ifa->ifa_addr->sa_family != AF_INET6)
1789                                 continue;
1790                         ifa6 = (struct in6_ifaddr *)ifa;
1791
1792                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1793                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1794                                 iffound = 1;
1795
1796                         /*
1797                          * IPv4-mapped addresses can only be returned by a
1798                          * Node Information proxy, since they represent
1799                          * addresses of IPv4-only nodes, which perforce do
1800                          * not implement this protocol.
1801                          * [icmp-name-lookups-07, Section 5.4]
1802                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1803                          * this function at this moment.
1804                          */
1805
1806                         /* What do we have to do about ::1? */
1807                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1808                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1809                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1810                                         continue;
1811                                 break;
1812                         case IPV6_ADDR_SCOPE_SITELOCAL:
1813                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1814                                         continue;
1815                                 break;
1816                         case IPV6_ADDR_SCOPE_GLOBAL:
1817                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1818                                         continue;
1819                                 break;
1820                         default:
1821                                 continue;
1822                         }
1823
1824                         /*
1825                          * check if anycast is okay.
1826                          * XXX: just experimental.  not in the spec.
1827                          */
1828                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1829                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1830                                 continue; /* we need only unicast addresses */
1831                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1832                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1833                                 continue;
1834                         }
1835                         addrsofif++; /* count the address */
1836                 }
1837                 IF_ADDR_RUNLOCK(ifp);
1838                 if (iffound) {
1839                         *ifpp = ifp;
1840                         IFNET_RUNLOCK_NOSLEEP();
1841                         return (addrsofif);
1842                 }
1843
1844                 addrs += addrsofif;
1845         }
1846         IFNET_RUNLOCK_NOSLEEP();
1847
1848         return (addrs);
1849 }
1850
1851 static int
1852 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1853     struct ifnet *ifp0, int resid)
1854 {
1855         struct ifnet *ifp;
1856         struct in6_ifaddr *ifa6;
1857         struct ifaddr *ifa;
1858         struct ifnet *ifp_dep = NULL;
1859         int copied = 0, allow_deprecated = 0;
1860         u_char *cp = (u_char *)(nni6 + 1);
1861         int niflags = ni6->ni_flags;
1862         u_int32_t ltime;
1863
1864         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1865                 return (0);     /* needless to copy */
1866
1867         IFNET_RLOCK_NOSLEEP();
1868         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1869   again:
1870
1871         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1872                 IF_ADDR_RLOCK(ifp);
1873                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1874                         if (ifa->ifa_addr->sa_family != AF_INET6)
1875                                 continue;
1876                         ifa6 = (struct in6_ifaddr *)ifa;
1877
1878                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1879                             allow_deprecated == 0) {
1880                                 /*
1881                                  * prefererred address should be put before
1882                                  * deprecated addresses.
1883                                  */
1884
1885                                 /* record the interface for later search */
1886                                 if (ifp_dep == NULL)
1887                                         ifp_dep = ifp;
1888
1889                                 continue;
1890                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1891                             allow_deprecated != 0)
1892                                 continue; /* we now collect deprecated addrs */
1893
1894                         /* What do we have to do about ::1? */
1895                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1896                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1897                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1898                                         continue;
1899                                 break;
1900                         case IPV6_ADDR_SCOPE_SITELOCAL:
1901                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1902                                         continue;
1903                                 break;
1904                         case IPV6_ADDR_SCOPE_GLOBAL:
1905                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1906                                         continue;
1907                                 break;
1908                         default:
1909                                 continue;
1910                         }
1911
1912                         /*
1913                          * check if anycast is okay.
1914                          * XXX: just experimental.  not in the spec.
1915                          */
1916                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1917                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1918                                 continue;
1919                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1920                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1921                                 continue;
1922                         }
1923
1924                         /* now we can copy the address */
1925                         if (resid < sizeof(struct in6_addr) +
1926                             sizeof(u_int32_t)) {
1927                                 IF_ADDR_RUNLOCK(ifp);
1928                                 /*
1929                                  * We give up much more copy.
1930                                  * Set the truncate flag and return.
1931                                  */
1932                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1933                                 IFNET_RUNLOCK_NOSLEEP();
1934                                 return (copied);
1935                         }
1936
1937                         /*
1938                          * Set the TTL of the address.
1939                          * The TTL value should be one of the following
1940                          * according to the specification:
1941                          *
1942                          * 1. The remaining lifetime of a DHCP lease on the
1943                          *    address, or
1944                          * 2. The remaining Valid Lifetime of a prefix from
1945                          *    which the address was derived through Stateless
1946                          *    Autoconfiguration.
1947                          *
1948                          * Note that we currently do not support stateful
1949                          * address configuration by DHCPv6, so the former
1950                          * case can't happen.
1951                          */
1952                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1953                                 ltime = ND6_INFINITE_LIFETIME;
1954                         else {
1955                                 if (ifa6->ia6_lifetime.ia6t_expire >
1956                                     time_second)
1957                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1958                                 else
1959                                         ltime = 0;
1960                         }
1961
1962                         bcopy(&ltime, cp, sizeof(u_int32_t));
1963                         cp += sizeof(u_int32_t);
1964
1965                         /* copy the address itself */
1966                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1967                             sizeof(struct in6_addr));
1968                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1969                         cp += sizeof(struct in6_addr);
1970
1971                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1972                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1973                 }
1974                 IF_ADDR_RUNLOCK(ifp);
1975                 if (ifp0)       /* we need search only on the specified IF */
1976                         break;
1977         }
1978
1979         if (allow_deprecated == 0 && ifp_dep != NULL) {
1980                 ifp = ifp_dep;
1981                 allow_deprecated = 1;
1982
1983                 goto again;
1984         }
1985
1986         IFNET_RUNLOCK_NOSLEEP();
1987
1988         return (copied);
1989 }
1990
1991 /*
1992  * XXX almost dup'ed code with rip6_input.
1993  */
1994 static int
1995 icmp6_rip6_input(struct mbuf **mp, int off)
1996 {
1997         struct mbuf *m = *mp;
1998         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1999         struct inpcb *in6p;
2000         struct inpcb *last = NULL;
2001         struct sockaddr_in6 fromsa;
2002         struct icmp6_hdr *icmp6;
2003         struct mbuf *opts = NULL;
2004
2005 #ifndef PULLDOWN_TEST
2006         /* this is assumed to be safe. */
2007         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
2008 #else
2009         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
2010         if (icmp6 == NULL) {
2011                 /* m is already reclaimed */
2012                 return (IPPROTO_DONE);
2013         }
2014 #endif
2015
2016         /*
2017          * XXX: the address may have embedded scope zone ID, which should be
2018          * hidden from applications.
2019          */
2020         bzero(&fromsa, sizeof(fromsa));
2021         fromsa.sin6_family = AF_INET6;
2022         fromsa.sin6_len = sizeof(struct sockaddr_in6);
2023         fromsa.sin6_addr = ip6->ip6_src;
2024         if (sa6_recoverscope(&fromsa)) {
2025                 m_freem(m);
2026                 return (IPPROTO_DONE);
2027         }
2028
2029         INP_INFO_RLOCK(&V_ripcbinfo);
2030         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
2031                 if ((in6p->inp_vflag & INP_IPV6) == 0)
2032                         continue;
2033                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
2034                         continue;
2035                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
2036                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
2037                         continue;
2038                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
2039                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
2040                         continue;
2041                 INP_RLOCK(in6p);
2042                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
2043                     in6p->in6p_icmp6filt)) {
2044                         INP_RUNLOCK(in6p);
2045                         continue;
2046                 }
2047                 if (last != NULL) {
2048                         struct  mbuf *n = NULL;
2049
2050                         /*
2051                          * Recent network drivers tend to allocate a single
2052                          * mbuf cluster, rather than to make a couple of
2053                          * mbufs without clusters.  Also, since the IPv6 code
2054                          * path tries to avoid m_pullup(), it is highly
2055                          * probable that we still have an mbuf cluster here
2056                          * even though the necessary length can be stored in an
2057                          * mbuf's internal buffer.
2058                          * Meanwhile, the default size of the receive socket
2059                          * buffer for raw sockets is not so large.  This means
2060                          * the possibility of packet loss is relatively higher
2061                          * than before.  To avoid this scenario, we copy the
2062                          * received data to a separate mbuf that does not use
2063                          * a cluster, if possible.
2064                          * XXX: it is better to copy the data after stripping
2065                          * intermediate headers.
2066                          */
2067                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2068                             m->m_len <= MHLEN) {
2069                                 MGET(n, M_DONTWAIT, m->m_type);
2070                                 if (n != NULL) {
2071                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2072                                                 bcopy(m->m_data, n->m_data,
2073                                                       m->m_len);
2074                                                 n->m_len = m->m_len;
2075                                         } else {
2076                                                 m_free(n);
2077                                                 n = NULL;
2078                                         }
2079                                 }
2080                         }
2081                         if (n != NULL ||
2082                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2083                                 if (last->inp_flags & INP_CONTROLOPTS)
2084                                         ip6_savecontrol(last, n, &opts);
2085                                 /* strip intermediate headers */
2086                                 m_adj(n, off);
2087                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2088                                 if (sbappendaddr_locked(
2089                                     &last->inp_socket->so_rcv,
2090                                     (struct sockaddr *)&fromsa, n, opts)
2091                                     == 0) {
2092                                         /* should notify about lost packet */
2093                                         m_freem(n);
2094                                         if (opts) {
2095                                                 m_freem(opts);
2096                                         }
2097                                         SOCKBUF_UNLOCK(
2098                                             &last->inp_socket->so_rcv);
2099                                 } else
2100                                         sorwakeup_locked(last->inp_socket);
2101                                 opts = NULL;
2102                         }
2103                         INP_RUNLOCK(last);
2104                 }
2105                 last = in6p;
2106         }
2107         INP_INFO_RUNLOCK(&V_ripcbinfo);
2108         if (last != NULL) {
2109                 if (last->inp_flags & INP_CONTROLOPTS)
2110                         ip6_savecontrol(last, m, &opts);
2111                 /* strip intermediate headers */
2112                 m_adj(m, off);
2113
2114                 /* avoid using mbuf clusters if possible (see above) */
2115                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2116                     m->m_len <= MHLEN) {
2117                         struct mbuf *n;
2118
2119                         MGET(n, M_DONTWAIT, m->m_type);
2120                         if (n != NULL) {
2121                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2122                                         bcopy(m->m_data, n->m_data, m->m_len);
2123                                         n->m_len = m->m_len;
2124
2125                                         m_freem(m);
2126                                         m = n;
2127                                 } else {
2128                                         m_freem(n);
2129                                         n = NULL;
2130                                 }
2131                         }
2132                 }
2133                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2134                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2135                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2136                         m_freem(m);
2137                         if (opts)
2138                                 m_freem(opts);
2139                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2140                 } else
2141                         sorwakeup_locked(last->inp_socket);
2142                 INP_RUNLOCK(last);
2143         } else {
2144                 m_freem(m);
2145                 IP6STAT_DEC(ip6s_delivered);
2146         }
2147         return IPPROTO_DONE;
2148 }
2149
2150 /*
2151  * Reflect the ip6 packet back to the source.
2152  * OFF points to the icmp6 header, counted from the top of the mbuf.
2153  */
2154 void
2155 icmp6_reflect(struct mbuf *m, size_t off)
2156 {
2157         struct ip6_hdr *ip6;
2158         struct icmp6_hdr *icmp6;
2159         struct in6_ifaddr *ia = NULL;
2160         int plen;
2161         int type, code;
2162         struct ifnet *outif = NULL;
2163         struct in6_addr origdst, src, *srcp = NULL;
2164
2165         /* too short to reflect */
2166         if (off < sizeof(struct ip6_hdr)) {
2167                 nd6log((LOG_DEBUG,
2168                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2169                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2170                     __FILE__, __LINE__));
2171                 goto bad;
2172         }
2173
2174         /*
2175          * If there are extra headers between IPv6 and ICMPv6, strip
2176          * off that header first.
2177          */
2178 #ifdef DIAGNOSTIC
2179         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2180                 panic("assumption failed in icmp6_reflect");
2181 #endif
2182         if (off > sizeof(struct ip6_hdr)) {
2183                 size_t l;
2184                 struct ip6_hdr nip6;
2185
2186                 l = off - sizeof(struct ip6_hdr);
2187                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2188                 m_adj(m, l);
2189                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2190                 if (m->m_len < l) {
2191                         if ((m = m_pullup(m, l)) == NULL)
2192                                 return;
2193                 }
2194                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2195         } else /* off == sizeof(struct ip6_hdr) */ {
2196                 size_t l;
2197                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2198                 if (m->m_len < l) {
2199                         if ((m = m_pullup(m, l)) == NULL)
2200                                 return;
2201                 }
2202         }
2203         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2204         ip6 = mtod(m, struct ip6_hdr *);
2205         ip6->ip6_nxt = IPPROTO_ICMPV6;
2206         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2207         type = icmp6->icmp6_type; /* keep type for statistics */
2208         code = icmp6->icmp6_code; /* ditto. */
2209
2210         origdst = ip6->ip6_dst;
2211         /*
2212          * ip6_input() drops a packet if its src is multicast.
2213          * So, the src is never multicast.
2214          */
2215         ip6->ip6_dst = ip6->ip6_src;
2216
2217         /*
2218          * If the incoming packet was addressed directly to us (i.e. unicast),
2219          * use dst as the src for the reply.
2220          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2221          * (for example) when we encounter an error while forwarding procedure
2222          * destined to a duplicated address of ours.
2223          * Note that ip6_getdstifaddr() may fail if we are in an error handling
2224          * procedure of an outgoing packet of our own, in which case we need
2225          * to search in the ifaddr list.
2226          */
2227         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2228                 if ((ia = ip6_getdstifaddr(m))) {
2229                         if (!(ia->ia6_flags &
2230                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2231                                 srcp = &ia->ia_addr.sin6_addr;
2232                 } else {
2233                         struct sockaddr_in6 d;
2234
2235                         bzero(&d, sizeof(d));
2236                         d.sin6_family = AF_INET6;
2237                         d.sin6_len = sizeof(d);
2238                         d.sin6_addr = origdst;
2239                         ia = (struct in6_ifaddr *)
2240                             ifa_ifwithaddr((struct sockaddr *)&d);
2241                         if (ia &&
2242                             !(ia->ia6_flags &
2243                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2244                                 srcp = &ia->ia_addr.sin6_addr;
2245                         }
2246                 }
2247         }
2248
2249         if (srcp == NULL) {
2250                 int e;
2251                 struct sockaddr_in6 sin6;
2252                 struct route_in6 ro;
2253
2254                 /*
2255                  * This case matches to multicasts, our anycast, or unicasts
2256                  * that we do not own.  Select a source address based on the
2257                  * source address of the erroneous packet.
2258                  */
2259                 bzero(&sin6, sizeof(sin6));
2260                 sin6.sin6_family = AF_INET6;
2261                 sin6.sin6_len = sizeof(sin6);
2262                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2263
2264                 bzero(&ro, sizeof(ro));
2265                 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2266                 if (ro.ro_rt)
2267                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2268                 if (e) {
2269                         char ip6buf[INET6_ADDRSTRLEN];
2270                         nd6log((LOG_DEBUG,
2271                             "icmp6_reflect: source can't be determined: "
2272                             "dst=%s, error=%d\n",
2273                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2274                         goto bad;
2275                 }
2276                 srcp = &src;
2277         }
2278
2279         ip6->ip6_src = *srcp;
2280         ip6->ip6_flow = 0;
2281         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2282         ip6->ip6_vfc |= IPV6_VERSION;
2283         ip6->ip6_nxt = IPPROTO_ICMPV6;
2284         if (outif)
2285                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2286         else if (m->m_pkthdr.rcvif) {
2287                 /* XXX: This may not be the outgoing interface */
2288                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2289         } else
2290                 ip6->ip6_hlim = V_ip6_defhlim;
2291
2292         icmp6->icmp6_cksum = 0;
2293         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2294             sizeof(struct ip6_hdr), plen);
2295
2296         /*
2297          * XXX option handling
2298          */
2299
2300         m->m_flags &= ~(M_BCAST|M_MCAST);
2301
2302         m_addr_changed(m);
2303
2304         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2305         if (outif)
2306                 icmp6_ifoutstat_inc(outif, type, code);
2307
2308         if (ia != NULL)
2309                 ifa_free(&ia->ia_ifa);
2310         return;
2311
2312  bad:
2313         if (ia != NULL)
2314                 ifa_free(&ia->ia_ifa);
2315         m_freem(m);
2316         return;
2317 }
2318
2319 void
2320 icmp6_fasttimo(void)
2321 {
2322
2323         mld_fasttimo();
2324 }
2325
2326 void
2327 icmp6_slowtimo(void)
2328 {
2329
2330         mld_slowtimo();
2331 }
2332
2333 static const char *
2334 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2335     struct in6_addr *tgt6)
2336 {
2337         static char buf[1024];
2338         char ip6bufs[INET6_ADDRSTRLEN];
2339         char ip6bufd[INET6_ADDRSTRLEN];
2340         char ip6buft[INET6_ADDRSTRLEN];
2341         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2342             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2343             ip6_sprintf(ip6buft, tgt6));
2344         return buf;
2345 }
2346
2347 void
2348 icmp6_redirect_input(struct mbuf *m, int off)
2349 {
2350         struct ifnet *ifp;
2351         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2352         struct nd_redirect *nd_rd;
2353         int icmp6len = ntohs(ip6->ip6_plen);
2354         char *lladdr = NULL;
2355         int lladdrlen = 0;
2356         struct rtentry *rt = NULL;
2357         int is_router;
2358         int is_onlink;
2359         struct in6_addr src6 = ip6->ip6_src;
2360         struct in6_addr redtgt6;
2361         struct in6_addr reddst6;
2362         union nd_opts ndopts;
2363         char ip6buf[INET6_ADDRSTRLEN];
2364
2365         M_ASSERTPKTHDR(m);
2366         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2367
2368         ifp = m->m_pkthdr.rcvif;
2369
2370         /* XXX if we are router, we don't update route by icmp6 redirect */
2371         if (V_ip6_forwarding)
2372                 goto freeit;
2373         if (!V_icmp6_rediraccept)
2374                 goto freeit;
2375
2376 #ifndef PULLDOWN_TEST
2377         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2378         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2379 #else
2380         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2381         if (nd_rd == NULL) {
2382                 ICMP6STAT_INC(icp6s_tooshort);
2383                 return;
2384         }
2385 #endif
2386         redtgt6 = nd_rd->nd_rd_target;
2387         reddst6 = nd_rd->nd_rd_dst;
2388
2389         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2390             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2391                 goto freeit;
2392         }
2393
2394         /* validation */
2395         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2396                 nd6log((LOG_ERR,
2397                     "ICMP6 redirect sent from %s rejected; "
2398                     "must be from linklocal\n",
2399                     ip6_sprintf(ip6buf, &src6)));
2400                 goto bad;
2401         }
2402         if (ip6->ip6_hlim != 255) {
2403                 nd6log((LOG_ERR,
2404                     "ICMP6 redirect sent from %s rejected; "
2405                     "hlim=%d (must be 255)\n",
2406                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2407                 goto bad;
2408         }
2409     {
2410         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2411         struct sockaddr_in6 sin6;
2412         struct in6_addr *gw6;
2413
2414         bzero(&sin6, sizeof(sin6));
2415         sin6.sin6_family = AF_INET6;
2416         sin6.sin6_len = sizeof(struct sockaddr_in6);
2417         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2418         rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB);
2419         if (rt) {
2420                 if (rt->rt_gateway == NULL ||
2421                     rt->rt_gateway->sa_family != AF_INET6) {
2422                         RTFREE_LOCKED(rt);
2423                         nd6log((LOG_ERR,
2424                             "ICMP6 redirect rejected; no route "
2425                             "with inet6 gateway found for redirect dst: %s\n",
2426                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2427                         goto bad;
2428                 }
2429
2430                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2431                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2432                         RTFREE_LOCKED(rt);
2433                         nd6log((LOG_ERR,
2434                             "ICMP6 redirect rejected; "
2435                             "not equal to gw-for-src=%s (must be same): "
2436                             "%s\n",
2437                             ip6_sprintf(ip6buf, gw6),
2438                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2439                         goto bad;
2440                 }
2441         } else {
2442                 nd6log((LOG_ERR,
2443                     "ICMP6 redirect rejected; "
2444                     "no route found for redirect dst: %s\n",
2445                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2446                 goto bad;
2447         }
2448         RTFREE_LOCKED(rt);
2449         rt = NULL;
2450     }
2451         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2452                 nd6log((LOG_ERR,
2453                     "ICMP6 redirect rejected; "
2454                     "redirect dst must be unicast: %s\n",
2455                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2456                 goto bad;
2457         }
2458
2459         is_router = is_onlink = 0;
2460         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2461                 is_router = 1;  /* router case */
2462         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2463                 is_onlink = 1;  /* on-link destination case */
2464         if (!is_router && !is_onlink) {
2465                 nd6log((LOG_ERR,
2466                     "ICMP6 redirect rejected; "
2467                     "neither router case nor onlink case: %s\n",
2468                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2469                 goto bad;
2470         }
2471         /* validation passed */
2472
2473         icmp6len -= sizeof(*nd_rd);
2474         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2475         if (nd6_options(&ndopts) < 0) {
2476                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2477                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2478                 /* nd6_options have incremented stats */
2479                 goto freeit;
2480         }
2481
2482         if (ndopts.nd_opts_tgt_lladdr) {
2483                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2484                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2485         }
2486
2487         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2488                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2489                     "(if %d, icmp6 packet %d): %s\n",
2490                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2491                     ifp->if_addrlen, lladdrlen - 2,
2492                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2493                 goto bad;
2494         }
2495
2496         /* RFC 2461 8.3 */
2497         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2498             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2499
2500         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2501                 /* perform rtredirect */
2502                 struct sockaddr_in6 sdst;
2503                 struct sockaddr_in6 sgw;
2504                 struct sockaddr_in6 ssrc;
2505                 u_int fibnum;
2506
2507                 bzero(&sdst, sizeof(sdst));
2508                 bzero(&sgw, sizeof(sgw));
2509                 bzero(&ssrc, sizeof(ssrc));
2510                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2511                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2512                         sizeof(struct sockaddr_in6);
2513                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2514                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2515                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2516                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2517                         in6_rtredirect((struct sockaddr *)&sdst,
2518                             (struct sockaddr *)&sgw, (struct sockaddr *)NULL,
2519                             RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc,
2520                             fibnum);
2521         }
2522         /* finally update cached route in each socket via pfctlinput */
2523     {
2524         struct sockaddr_in6 sdst;
2525
2526         bzero(&sdst, sizeof(sdst));
2527         sdst.sin6_family = AF_INET6;
2528         sdst.sin6_len = sizeof(struct sockaddr_in6);
2529         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2530         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2531 #ifdef IPSEC
2532         key_sa_routechange((struct sockaddr *)&sdst);
2533 #endif /* IPSEC */
2534     }
2535
2536  freeit:
2537         m_freem(m);
2538         return;
2539
2540  bad:
2541         ICMP6STAT_INC(icp6s_badredirect);
2542         m_freem(m);
2543 }
2544
2545 void
2546 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2547 {
2548         struct ifnet *ifp;      /* my outgoing interface */
2549         struct in6_addr *ifp_ll6;
2550         struct in6_addr *router_ll6;
2551         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2552         struct mbuf *m = NULL;  /* newly allocated one */
2553         struct m_tag *mtag;
2554         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2555         struct nd_redirect *nd_rd;
2556         struct llentry *ln = NULL;
2557         size_t maxlen;
2558         u_char *p;
2559         struct ifnet *outif = NULL;
2560         struct sockaddr_in6 src_sa;
2561
2562         icmp6_errcount(ND_REDIRECT, 0);
2563
2564         /* if we are not router, we don't send icmp6 redirect */
2565         if (!V_ip6_forwarding)
2566                 goto fail;
2567
2568         /* sanity check */
2569         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2570                 goto fail;
2571
2572         /*
2573          * Address check:
2574          *  the source address must identify a neighbor, and
2575          *  the destination address must not be a multicast address
2576          *  [RFC 2461, sec 8.2]
2577          */
2578         sip6 = mtod(m0, struct ip6_hdr *);
2579         bzero(&src_sa, sizeof(src_sa));
2580         src_sa.sin6_family = AF_INET6;
2581         src_sa.sin6_len = sizeof(src_sa);
2582         src_sa.sin6_addr = sip6->ip6_src;
2583         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2584                 goto fail;
2585         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2586                 goto fail;      /* what should we do here? */
2587
2588         /* rate limit */
2589         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2590                 goto fail;
2591
2592         /*
2593          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2594          * we almost always ask for an mbuf cluster for simplicity.
2595          * (MHLEN < IPV6_MMTU is almost always true)
2596          */
2597 #if IPV6_MMTU >= MCLBYTES
2598 # error assumption failed about IPV6_MMTU and MCLBYTES
2599 #endif
2600         MGETHDR(m, M_DONTWAIT, MT_HEADER);
2601         if (m && IPV6_MMTU >= MHLEN)
2602                 MCLGET(m, M_DONTWAIT);
2603         if (!m)
2604                 goto fail;
2605         M_SETFIB(m, rt->rt_fibnum);
2606         m->m_pkthdr.rcvif = NULL;
2607         m->m_len = 0;
2608         maxlen = M_TRAILINGSPACE(m);
2609         maxlen = min(IPV6_MMTU, maxlen);
2610         /* just for safety */
2611         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2612             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2613                 goto fail;
2614         }
2615
2616         {
2617                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2618                 struct in6_ifaddr *ia;
2619                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2620                                                  IN6_IFF_NOTREADY|
2621                                                  IN6_IFF_ANYCAST)) == NULL)
2622                         goto fail;
2623                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2624                 /* XXXRW: reference released prematurely. */
2625                 ifa_free(&ia->ia_ifa);
2626         }
2627
2628         /* get ip6 linklocal address for the router. */
2629         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2630                 struct sockaddr_in6 *sin6;
2631                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2632                 router_ll6 = &sin6->sin6_addr;
2633                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2634                         router_ll6 = (struct in6_addr *)NULL;
2635         } else
2636                 router_ll6 = (struct in6_addr *)NULL;
2637
2638         /* ip6 */
2639         ip6 = mtod(m, struct ip6_hdr *);
2640         ip6->ip6_flow = 0;
2641         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2642         ip6->ip6_vfc |= IPV6_VERSION;
2643         /* ip6->ip6_plen will be set later */
2644         ip6->ip6_nxt = IPPROTO_ICMPV6;
2645         ip6->ip6_hlim = 255;
2646         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2647         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2648         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2649
2650         /* ND Redirect */
2651         nd_rd = (struct nd_redirect *)(ip6 + 1);
2652         nd_rd->nd_rd_type = ND_REDIRECT;
2653         nd_rd->nd_rd_code = 0;
2654         nd_rd->nd_rd_reserved = 0;
2655         if (rt->rt_flags & RTF_GATEWAY) {
2656                 /*
2657                  * nd_rd->nd_rd_target must be a link-local address in
2658                  * better router cases.
2659                  */
2660                 if (!router_ll6)
2661                         goto fail;
2662                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2663                     sizeof(nd_rd->nd_rd_target));
2664                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2665                     sizeof(nd_rd->nd_rd_dst));
2666         } else {
2667                 /* make sure redtgt == reddst */
2668                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2669                     sizeof(nd_rd->nd_rd_target));
2670                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2671                     sizeof(nd_rd->nd_rd_dst));
2672         }
2673
2674         p = (u_char *)(nd_rd + 1);
2675
2676         if (!router_ll6)
2677                 goto nolladdropt;
2678
2679         {
2680                 /* target lladdr option */
2681                 int len;
2682                 struct nd_opt_hdr *nd_opt;
2683                 char *lladdr;
2684
2685                 IF_AFDATA_RLOCK(ifp);
2686                 ln = nd6_lookup(router_ll6, 0, ifp);
2687                 IF_AFDATA_RUNLOCK(ifp);
2688                 if (ln == NULL)
2689                         goto nolladdropt;
2690
2691                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2692                 len = (len + 7) & ~7;   /* round by 8 */
2693                 /* safety check */
2694                 if (len + (p - (u_char *)ip6) > maxlen)
2695                         goto nolladdropt;
2696
2697                 if (ln->la_flags & LLE_VALID) {
2698                         nd_opt = (struct nd_opt_hdr *)p;
2699                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2700                         nd_opt->nd_opt_len = len >> 3;
2701                         lladdr = (char *)(nd_opt + 1);
2702                         bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2703                         p += len;
2704                 }
2705         }
2706 nolladdropt:
2707         if (ln != NULL)
2708                 LLE_RUNLOCK(ln);
2709
2710         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2711
2712         /* just to be safe */
2713 #ifdef M_DECRYPTED      /*not openbsd*/
2714         if (m0->m_flags & M_DECRYPTED)
2715                 goto noredhdropt;
2716 #endif
2717         if (p - (u_char *)ip6 > maxlen)
2718                 goto noredhdropt;
2719
2720         {
2721                 /* redirected header option */
2722                 int len;
2723                 struct nd_opt_rd_hdr *nd_opt_rh;
2724
2725                 /*
2726                  * compute the maximum size for icmp6 redirect header option.
2727                  * XXX room for auth header?
2728                  */
2729                 len = maxlen - (p - (u_char *)ip6);
2730                 len &= ~7;
2731
2732                 /* This is just for simplicity. */
2733                 if (m0->m_pkthdr.len != m0->m_len) {
2734                         if (m0->m_next) {
2735                                 m_freem(m0->m_next);
2736                                 m0->m_next = NULL;
2737                         }
2738                         m0->m_pkthdr.len = m0->m_len;
2739                 }
2740
2741                 /*
2742                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2743                  * about padding/truncate rule for the original IP packet.
2744                  * From the discussion on IPv6imp in Feb 1999,
2745                  * the consensus was:
2746                  * - "attach as much as possible" is the goal
2747                  * - pad if not aligned (original size can be guessed by
2748                  *   original ip6 header)
2749                  * Following code adds the padding if it is simple enough,
2750                  * and truncates if not.
2751                  */
2752                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2753                         panic("assumption failed in %s:%d", __FILE__,
2754                             __LINE__);
2755
2756                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2757                         /* not enough room, truncate */
2758                         m0->m_pkthdr.len = m0->m_len = len -
2759                             sizeof(*nd_opt_rh);
2760                 } else {
2761                         /* enough room, pad or truncate */
2762                         size_t extra;
2763
2764                         extra = m0->m_pkthdr.len % 8;
2765                         if (extra) {
2766                                 /* pad if easy enough, truncate if not */
2767                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2768                                         /* pad */
2769                                         m0->m_len += (8 - extra);
2770                                         m0->m_pkthdr.len += (8 - extra);
2771                                 } else {
2772                                         /* truncate */
2773                                         m0->m_pkthdr.len -= extra;
2774                                         m0->m_len -= extra;
2775                                 }
2776                         }
2777                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2778                         m0->m_pkthdr.len = m0->m_len = len -
2779                             sizeof(*nd_opt_rh);
2780                 }
2781
2782                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2783                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2784                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2785                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2786                 p += sizeof(*nd_opt_rh);
2787                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2788
2789                 /* connect m0 to m */
2790                 m_tag_delete_chain(m0, NULL);
2791                 m0->m_flags &= ~M_PKTHDR;
2792                 m->m_next = m0;
2793                 m->m_pkthdr.len = m->m_len + m0->m_len;
2794                 m0 = NULL;
2795         }
2796 noredhdropt:;
2797         if (m0) {
2798                 m_freem(m0);
2799                 m0 = NULL;
2800         }
2801
2802         /* XXX: clear embedded link IDs in the inner header */
2803         in6_clearscope(&sip6->ip6_src);
2804         in6_clearscope(&sip6->ip6_dst);
2805         in6_clearscope(&nd_rd->nd_rd_target);
2806         in6_clearscope(&nd_rd->nd_rd_dst);
2807
2808         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2809
2810         nd_rd->nd_rd_cksum = 0;
2811         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2812             sizeof(*ip6), ntohs(ip6->ip6_plen));
2813
2814         if (send_sendso_input_hook != NULL) {
2815                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2816                         M_NOWAIT);
2817                 if (mtag == NULL)
2818                         goto fail;
2819                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2820                 m_tag_prepend(m, mtag);
2821         }
2822
2823         /* send the packet to outside... */
2824         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2825         if (outif) {
2826                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2827                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2828         }
2829         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2830
2831         return;
2832
2833 fail:
2834         if (m)
2835                 m_freem(m);
2836         if (m0)
2837                 m_freem(m0);
2838 }
2839
2840 /*
2841  * ICMPv6 socket option processing.
2842  */
2843 int
2844 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2845 {
2846         int error = 0;
2847         int optlen;
2848         struct inpcb *inp = sotoinpcb(so);
2849         int level, op, optname;
2850
2851         if (sopt) {
2852                 level = sopt->sopt_level;
2853                 op = sopt->sopt_dir;
2854                 optname = sopt->sopt_name;
2855                 optlen = sopt->sopt_valsize;
2856         } else
2857                 level = op = optname = optlen = 0;
2858
2859         if (level != IPPROTO_ICMPV6) {
2860                 return EINVAL;
2861         }
2862
2863         switch (op) {
2864         case PRCO_SETOPT:
2865                 switch (optname) {
2866                 case ICMP6_FILTER:
2867                     {
2868                         struct icmp6_filter ic6f;
2869
2870                         if (optlen != sizeof(ic6f)) {
2871                                 error = EMSGSIZE;
2872                                 break;
2873                         }
2874                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2875                         if (error == 0) {
2876                                 INP_WLOCK(inp);
2877                                 *inp->in6p_icmp6filt = ic6f;
2878                                 INP_WUNLOCK(inp);
2879                         }
2880                         break;
2881                     }
2882
2883                 default:
2884                         error = ENOPROTOOPT;
2885                         break;
2886                 }
2887                 break;
2888
2889         case PRCO_GETOPT:
2890                 switch (optname) {
2891                 case ICMP6_FILTER:
2892                     {
2893                         struct icmp6_filter ic6f;
2894
2895                         INP_RLOCK(inp);
2896                         ic6f = *inp->in6p_icmp6filt;
2897                         INP_RUNLOCK(inp);
2898                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2899                         break;
2900                     }
2901
2902                 default:
2903                         error = ENOPROTOOPT;
2904                         break;
2905                 }
2906                 break;
2907         }
2908
2909         return (error);
2910 }
2911
2912 /*
2913  * Perform rate limit check.
2914  * Returns 0 if it is okay to send the icmp6 packet.
2915  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2916  * limitation.
2917  *
2918  * XXX per-destination/type check necessary?
2919  *
2920  * dst - not used at this moment
2921  * type - not used at this moment
2922  * code - not used at this moment
2923  */
2924 static int
2925 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2926     const int code)
2927 {
2928         int ret;
2929
2930         ret = 0;        /* okay to send */
2931
2932         /* PPS limit */
2933         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2934             V_icmp6errppslim)) {
2935                 /* The packet is subject to rate limit */
2936                 ret++;
2937         }
2938
2939         return ret;
2940 }