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 #define MBUF_PRIVATE    /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70
  71 #include <sys/param.h>
  72 #include <sys/domain.h>
  73 #include <sys/jail.h>
  74 #include <sys/kernel.h>
  75 #include <sys/lock.h>
  76 #include <sys/malloc.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/proc.h>
  79 #include <sys/protosw.h>
  80 #include <sys/signalvar.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #include <sys/sx.h>
  84 #include <sys/syslog.h>
  85 #include <sys/systm.h>
  86 #include <sys/time.h>
  87
  88 #include <net/if.h>
  89 #include <net/if_var.h>
  90 #include <net/if_dl.h>
  91 #include <net/if_llatbl.h>
  92 #include <net/if_types.h>
  93 #include <net/route.h>
  94 #include <net/vnet.h>
  95
  96 #include <netinet/in.h>
  97 #include <netinet/in_pcb.h>
  98 #include <netinet/in_var.h>
  99 #include <netinet/ip6.h>
 100 #include <netinet/icmp6.h>
 101 #include <netinet/tcp_var.h>
 102
 103 #include <netinet6/in6_fib.h>
 104 #include <netinet6/in6_ifattach.h>
 105 #include <netinet6/in6_pcb.h>
 106 #include <netinet6/ip6protosw.h>
 107 #include <netinet6/ip6_var.h>
 108 #include <netinet6/scope6_var.h>
 109 #include <netinet6/mld6_var.h>
 110 #include <netinet6/nd6.h>
 111 #include <netinet6/send.h>
 112
 113 extern struct domain inet6domain;
 114
 115 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
 116 VNET_PCPUSTAT_SYSINIT(icmp6stat);
 117
 118 #ifdef VIMAGE
 119 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
 120 #endif /* VIMAGE */
 121
 122 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 123 VNET_DECLARE(struct inpcbhead, ripcb);
 124 VNET_DECLARE(int, icmp6errppslim);
 125 static VNET_DEFINE(int, icmp6errpps_count) = 0;
 126 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 127 VNET_DECLARE(int, icmp6_nodeinfo);
 128
 129 #define V_ripcbinfo                     VNET(ripcbinfo)
 130 #define V_ripcb                         VNET(ripcb)
 131 #define V_icmp6errppslim                VNET(icmp6errppslim)
 132 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 133 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 134 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 135
 136 static void icmp6_errcount(int, int);
 137 static int icmp6_rip6_input(struct mbuf **, int);
 138 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 139 static const char *icmp6_redirect_diag(struct in6_addr *,
 140         struct in6_addr *, struct in6_addr *);
 141 static struct mbuf *ni6_input(struct mbuf *, int);
 142 static struct mbuf *ni6_nametodns(const char *, int, int);
 143 static int ni6_dnsmatch(const char *, int, const char *, int);
 144 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 145                           struct ifnet **, struct in6_addr *);
 146 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 147                                 struct ifnet *, int);
 148 static int icmp6_notify_error(struct mbuf **, int, int, int);
 149
 150 /*
 151  * Kernel module interface for updating icmp6stat.  The argument is an index
 152  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 153  * general layout of icmp6stat into the caller, it doesn't encode its
 154  * location, so that future changes to add, for example, per-CPU stats
 155  * support won't cause binary compatibility problems for kernel modules.
 156  */
 157 void
 158 kmod_icmp6stat_inc(int statnum)
 159 {
 160
 161         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 162 }
 163
 164 static void
 165 icmp6_errcount(int type, int code)
 166 {
 167         switch (type) {
 168         case ICMP6_DST_UNREACH:
 169                 switch (code) {
 170                 case ICMP6_DST_UNREACH_NOROUTE:
 171                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 172                         return;
 173                 case ICMP6_DST_UNREACH_ADMIN:
 174                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 175                         return;
 176                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 177                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 178                         return;
 179                 case ICMP6_DST_UNREACH_ADDR:
 180                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 181                         return;
 182                 case ICMP6_DST_UNREACH_NOPORT:
 183                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 184                         return;
 185                 }
 186                 break;
 187         case ICMP6_PACKET_TOO_BIG:
 188                 ICMP6STAT_INC(icp6s_opacket_too_big);
 189                 return;
 190         case ICMP6_TIME_EXCEEDED:
 191                 switch (code) {
 192                 case ICMP6_TIME_EXCEED_TRANSIT:
 193                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 194                         return;
 195                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 196                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 197                         return;
 198                 }
 199                 break;
 200         case ICMP6_PARAM_PROB:
 201                 switch (code) {
 202                 case ICMP6_PARAMPROB_HEADER:
 203                         ICMP6STAT_INC(icp6s_oparamprob_header);
 204                         return;
 205                 case ICMP6_PARAMPROB_NEXTHEADER:
 206                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 207                         return;
 208                 case ICMP6_PARAMPROB_OPTION:
 209                         ICMP6STAT_INC(icp6s_oparamprob_option);
 210                         return;
 211                 }
 212                 break;
 213         case ND_REDIRECT:
 214                 ICMP6STAT_INC(icp6s_oredirect);
 215                 return;
 216         }
 217         ICMP6STAT_INC(icp6s_ounknown);
 218 }
 219
 220 /*
 221  * A wrapper function for icmp6_error() necessary when the erroneous packet
 222  * may not contain enough scope zone information.
 223  */
 224 void
 225 icmp6_error2(struct mbuf *m, int type, int code, int param,
 226     struct ifnet *ifp)
 227 {
 228         struct ip6_hdr *ip6;
 229
 230         if (ifp == NULL)
 231                 return;
 232
 233 #ifndef PULLDOWN_TEST
 234         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 235 #else
 236         if (m->m_len < sizeof(struct ip6_hdr)) {
 237                 m = m_pullup(m, sizeof(struct ip6_hdr));
 238                 if (m == NULL)
 239                         return;
 240         }
 241 #endif
 242
 243         ip6 = mtod(m, struct ip6_hdr *);
 244
 245         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 246                 return;
 247         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 248                 return;
 249
 250         icmp6_error(m, type, code, param);
 251 }
 252
 253 /*
 254  * Generate an error packet of type error in response to bad IP6 packet.
 255  */
 256 void
 257 icmp6_error(struct mbuf *m, int type, int code, int param)
 258 {
 259         struct ip6_hdr *oip6, *nip6;
 260         struct icmp6_hdr *icmp6;
 261         u_int preplen;
 262         int off;
 263         int nxt;
 264
 265         ICMP6STAT_INC(icp6s_error);
 266
 267         /* count per-type-code statistics */
 268         icmp6_errcount(type, code);
 269
 270 #ifdef M_DECRYPTED      /*not openbsd*/
 271         if (m->m_flags & M_DECRYPTED) {
 272                 ICMP6STAT_INC(icp6s_canterror);
 273                 goto freeit;
 274         }
 275 #endif
 276
 277 #ifndef PULLDOWN_TEST
 278         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 279 #else
 280         if (m->m_len < sizeof(struct ip6_hdr)) {
 281                 m = m_pullup(m, sizeof(struct ip6_hdr));
 282                 if (m == NULL)
 283                         return;
 284         }
 285 #endif
 286         oip6 = mtod(m, struct ip6_hdr *);
 287
 288         /*
 289          * If the destination address of the erroneous packet is a multicast
 290          * address, or the packet was sent using link-layer multicast,
 291          * we should basically suppress sending an error (RFC 2463, Section
 292          * 2.4).
 293          * We have two exceptions (the item e.2 in that section):
 294          * - the Packet Too Big message can be sent for path MTU discovery.
 295          * - the Parameter Problem Message that can be allowed an icmp6 error
 296          *   in the option type field.  This check has been done in
 297          *   ip6_unknown_opt(), so we can just check the type and code.
 298          */
 299         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 300              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 301             (type != ICMP6_PACKET_TOO_BIG &&
 302              (type != ICMP6_PARAM_PROB ||
 303               code != ICMP6_PARAMPROB_OPTION)))
 304                 goto freeit;
 305
 306         /*
 307          * RFC 2463, 2.4 (e.5): source address check.
 308          * XXX: the case of anycast source?
 309          */
 310         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 311             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 312                 goto freeit;
 313
 314         /*
 315          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 316          * don't do it.
 317          */
 318         nxt = -1;
 319         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 320         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 321                 struct icmp6_hdr *icp;
 322
 323 #ifndef PULLDOWN_TEST
 324                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 325                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 326 #else
 327                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 328                         sizeof(*icp));
 329                 if (icp == NULL) {
 330                         ICMP6STAT_INC(icp6s_tooshort);
 331                         return;
 332                 }
 333 #endif
 334                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 335                     icp->icmp6_type == ND_REDIRECT) {
 336                         /*
 337                          * ICMPv6 error
 338                          * Special case: for redirect (which is
 339                          * informational) we must not send icmp6 error.
 340                          */
 341                         ICMP6STAT_INC(icp6s_canterror);
 342                         goto freeit;
 343                 } else {
 344                         /* ICMPv6 informational - send the error */
 345                 }
 346         } else {
 347                 /* non-ICMPv6 - send the error */
 348         }
 349
 350         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 351
 352         /* Finally, do rate limitation check. */
 353         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 354                 ICMP6STAT_INC(icp6s_toofreq);
 355                 goto freeit;
 356         }
 357
 358         /*
 359          * OK, ICMP6 can be generated.
 360          */
 361
 362         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 363                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 364
 365         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 366         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 367         if (m == NULL) {
 368                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 369                 return;
 370         }
 371
 372         nip6 = mtod(m, struct ip6_hdr *);
 373         nip6->ip6_src  = oip6->ip6_src;
 374         nip6->ip6_dst  = oip6->ip6_dst;
 375
 376         in6_clearscope(&oip6->ip6_src);
 377         in6_clearscope(&oip6->ip6_dst);
 378
 379         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 380         icmp6->icmp6_type = type;
 381         icmp6->icmp6_code = code;
 382         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 383
 384         /*
 385          * icmp6_reflect() is designed to be in the input path.
 386          * icmp6_error() can be called from both input and output path,
 387          * and if we are in output path rcvif could contain bogus value.
 388          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 389          * information in ip header (nip6).
 390          */
 391         m->m_pkthdr.rcvif = NULL;
 392
 393         ICMP6STAT_INC(icp6s_outhist[type]);
 394         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 395
 396         return;
 397
 398   freeit:
 399         /*
 400          * If we can't tell whether or not we can generate ICMP6, free it.
 401          */
 402         m_freem(m);
 403 }
 404
 405 /*
 406  * Process a received ICMP6 message.
 407  */
 408 int
 409 icmp6_input(struct mbuf **mp, int *offp, int proto)
 410 {
 411         struct mbuf *m = *mp, *n;
 412         struct ifnet *ifp;
 413         struct ip6_hdr *ip6, *nip6;
 414         struct icmp6_hdr *icmp6, *nicmp6;
 415         int off = *offp;
 416         int icmp6len = m->m_pkthdr.len - *offp;
 417         int code, sum, noff;
 418         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 419         int ip6len, error;
 420
 421         ifp = m->m_pkthdr.rcvif;
 422
 423 #ifndef PULLDOWN_TEST
 424         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 425         /* m might change if M_LOOP.  So, call mtod after this */
 426 #endif
 427
 428         /*
 429          * Locate icmp6 structure in mbuf, and check
 430          * that not corrupted and of at least minimum length
 431          */
 432
 433         ip6 = mtod(m, struct ip6_hdr *);
 434         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 435         if (icmp6len < sizeof(struct icmp6_hdr)) {
 436                 ICMP6STAT_INC(icp6s_tooshort);
 437                 goto freeit;
 438         }
 439
 440         /*
 441          * Check multicast group membership.
 442          * Note: SSM filters are not applied for ICMPv6 traffic.
 443          */
 444         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 445                 struct in6_multi        *inm;
 446
 447                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 448                 if (inm == NULL) {
 449                         IP6STAT_INC(ip6s_notmember);
 450                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 451                         goto freeit;
 452                 }
 453         }
 454
 455         /*
 456          * calculate the checksum
 457          */
 458 #ifndef PULLDOWN_TEST
 459         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 460 #else
 461         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 462         if (icmp6 == NULL) {
 463                 ICMP6STAT_INC(icp6s_tooshort);
 464                 return IPPROTO_DONE;
 465         }
 466 #endif
 467         code = icmp6->icmp6_code;
 468
 469         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 470                 nd6log((LOG_ERR,
 471                     "ICMP6 checksum error(%d|%x) %s\n",
 472                     icmp6->icmp6_type, sum,
 473                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 474                 ICMP6STAT_INC(icp6s_checksum);
 475                 goto freeit;
 476         }
 477
 478         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 479         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 480         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 481                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 482
 483         switch (icmp6->icmp6_type) {
 484         case ICMP6_DST_UNREACH:
 485                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 486                 switch (code) {
 487                 case ICMP6_DST_UNREACH_NOROUTE:
 488                 case ICMP6_DST_UNREACH_ADDR:    /* PRC_HOSTDEAD is a DOS */
 489                         code = PRC_UNREACH_NET;
 490                         break;
 491                 case ICMP6_DST_UNREACH_ADMIN:
 492                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 493                         code = PRC_UNREACH_ADMIN_PROHIB;
 494                         break;
 495                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 496                         /* I mean "source address was incorrect." */
 497                         code = PRC_PARAMPROB;
 498                         break;
 499                 case ICMP6_DST_UNREACH_NOPORT:
 500                         code = PRC_UNREACH_PORT;
 501                         break;
 502                 default:
 503                         goto badcode;
 504                 }
 505                 goto deliver;
 506                 break;
 507
 508         case ICMP6_PACKET_TOO_BIG:
 509                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 510
 511                 /* validation is made in icmp6_mtudisc_update */
 512
 513                 code = PRC_MSGSIZE;
 514
 515                 /*
 516                  * Updating the path MTU will be done after examining
 517                  * intermediate extension headers.
 518                  */
 519                 goto deliver;
 520                 break;
 521
 522         case ICMP6_TIME_EXCEEDED:
 523                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 524                 switch (code) {
 525                 case ICMP6_TIME_EXCEED_TRANSIT:
 526                         code = PRC_TIMXCEED_INTRANS;
 527                         break;
 528                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 529                         code = PRC_TIMXCEED_REASS;
 530                         break;
 531                 default:
 532                         goto badcode;
 533                 }
 534                 goto deliver;
 535                 break;
 536
 537         case ICMP6_PARAM_PROB:
 538                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 539                 switch (code) {
 540                 case ICMP6_PARAMPROB_NEXTHEADER:
 541                         code = PRC_UNREACH_PROTOCOL;
 542                         break;
 543                 case ICMP6_PARAMPROB_HEADER:
 544                 case ICMP6_PARAMPROB_OPTION:
 545                         code = PRC_PARAMPROB;
 546                         break;
 547                 default:
 548                         goto badcode;
 549                 }
 550                 goto deliver;
 551                 break;
 552
 553         case ICMP6_ECHO_REQUEST:
 554                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 555                 if (code != 0)
 556                         goto badcode;
 557                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 558                         /* Give up remote */
 559                         break;
 560                 }
 561                 if (!M_WRITABLE(n)
 562                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 563                         struct mbuf *n0 = n;
 564                         int n0len;
 565
 566                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 567                         n = m_gethdr(M_NOWAIT, n0->m_type);
 568                         if (n == NULL) {
 569                                 /* Give up remote */
 570                                 m_freem(n0);
 571                                 break;
 572                         }
 573
 574                         m_move_pkthdr(n, n0);   /* FIB copied. */
 575                         n0len = n0->m_pkthdr.len;       /* save for use below */
 576                         /*
 577                          * Copy IPv6 and ICMPv6 only.
 578                          */
 579                         nip6 = mtod(n, struct ip6_hdr *);
 580                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 581                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 582                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 583                         noff = sizeof(struct ip6_hdr);
 584                         /* new mbuf contains only ipv6+icmpv6 headers */
 585                         n->m_len = noff + sizeof(struct icmp6_hdr);
 586                         /*
 587                          * Adjust mbuf.  ip6_plen will be adjusted in
 588                          * ip6_output().
 589                          */
 590                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 591                         /* recalculate complete packet size */
 592                         n->m_pkthdr.len = n0len + (noff - off);
 593                         n->m_next = n0;
 594                 } else {
 595                         nip6 = mtod(n, struct ip6_hdr *);
 596                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 597                             sizeof(*nicmp6));
 598                         noff = off;
 599                 }
 600                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 601                 nicmp6->icmp6_code = 0;
 602                 if (n) {
 603                         ICMP6STAT_INC(icp6s_reflect);
 604                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 605                         icmp6_reflect(n, noff);
 606                 }
 607                 break;
 608
 609         case ICMP6_ECHO_REPLY:
 610                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 611                 if (code != 0)
 612                         goto badcode;
 613                 break;
 614
 615         case MLD_LISTENER_QUERY:
 616         case MLD_LISTENER_REPORT:
 617         case MLD_LISTENER_DONE:
 618         case MLDV2_LISTENER_REPORT:
 619                 /*
 620                  * Drop MLD traffic which is not link-local, has a hop limit
 621                  * of greater than 1 hop, or which does not have the
 622                  * IPv6 HBH Router Alert option.
 623                  * As IPv6 HBH options are stripped in ip6_input() we must
 624                  * check an mbuf header flag.
 625                  * XXX Should we also sanity check that these messages
 626                  * were directed to a link-local multicast prefix?
 627                  */
 628                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 629                         goto freeit;
 630                 if (mld_input(m, off, icmp6len) != 0)
 631                         return (IPPROTO_DONE);
 632                 /* m stays. */
 633                 break;
 634
 635         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 636             {
 637                 enum { WRU, FQDN } mode;
 638
 639                 if (!V_icmp6_nodeinfo)
 640                         break;
 641
 642                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 643                         mode = WRU;
 644                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 645                         mode = FQDN;
 646                 else
 647                         goto badlen;
 648
 649                 if (mode == FQDN) {
 650 #ifndef PULLDOWN_TEST
 651                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 652                             IPPROTO_DONE);
 653 #endif
 654                         n = m_copy(m, 0, M_COPYALL);
 655                         if (n)
 656                                 n = ni6_input(n, off);
 657                         /* XXX meaningless if n == NULL */
 658                         noff = sizeof(struct ip6_hdr);
 659                 } else {
 660                         struct prison *pr;
 661                         u_char *p;
 662                         int maxhlen, hlen;
 663
 664                         /*
 665                          * XXX: this combination of flags is pointless,
 666                          * but should we keep this for compatibility?
 667                          */
 668                         if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
 669                             ICMP6_NODEINFO_TMPADDROK)) !=
 670                             (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
 671                                 break;
 672
 673                         if (code != 0)
 674                                 goto badcode;
 675
 676                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 677                         n = m_gethdr(M_NOWAIT, m->m_type);
 678                         if (n == NULL) {
 679                                 /* Give up remote */
 680                                 break;
 681                         }
 682                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 683                                 /*
 684                                  * Previous code did a blind M_COPY_PKTHDR
 685                                  * and said "just for rcvif".  If true, then
 686                                  * we could tolerate the dup failing (due to
 687                                  * the deep copy of the tag chain).  For now
 688                                  * be conservative and just fail.
 689                                  */
 690                                 m_free(n);
 691                                 n = NULL;
 692                         }
 693                         maxhlen = M_TRAILINGSPACE(n) -
 694                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 695                         pr = curthread->td_ucred->cr_prison;
 696                         mtx_lock(&pr->pr_mtx);
 697                         hlen = strlen(pr->pr_hostname);
 698                         if (maxhlen > hlen)
 699                                 maxhlen = hlen;
 700                         /*
 701                          * Copy IPv6 and ICMPv6 only.
 702                          */
 703                         nip6 = mtod(n, struct ip6_hdr *);
 704                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 705                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 706                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 707                         p = (u_char *)(nicmp6 + 1);
 708                         bzero(p, 4);
 709                         /* meaningless TTL */
 710                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 711                         mtx_unlock(&pr->pr_mtx);
 712                         noff = sizeof(struct ip6_hdr);
 713                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 714                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 715                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 716                         nicmp6->icmp6_code = 0;
 717                 }
 718                 if (n) {
 719                         ICMP6STAT_INC(icp6s_reflect);
 720                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 721                         icmp6_reflect(n, noff);
 722                 }
 723                 break;
 724             }
 725
 726         case ICMP6_WRUREPLY:
 727                 if (code != 0)
 728                         goto badcode;
 729                 break;
 730
 731         case ND_ROUTER_SOLICIT:
 732                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 733                 if (code != 0)
 734                         goto badcode;
 735                 if (icmp6len < sizeof(struct nd_router_solicit))
 736                         goto badlen;
 737                 if (send_sendso_input_hook != NULL) {
 738                         IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
 739                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 740                         if (error == 0) {
 741                                 m = NULL;
 742                                 goto freeit;
 743                         }
 744                 }
 745                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 746                 nd6_rs_input(m, off, icmp6len);
 747                 m = n;
 748                 if (m == NULL)
 749                         goto freeit;
 750                 break;
 751
 752         case ND_ROUTER_ADVERT:
 753                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 754                 if (code != 0)
 755                         goto badcode;
 756                 if (icmp6len < sizeof(struct nd_router_advert))
 757                         goto badlen;
 758                 if (send_sendso_input_hook != NULL) {
 759                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 760                         if (error == 0) {
 761                                 m = NULL;
 762                                 goto freeit;
 763                         }
 764                 }
 765                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 766                 nd6_ra_input(m, off, icmp6len);
 767                 m = n;
 768                 if (m == NULL)
 769                         goto freeit;
 770                 break;
 771
 772         case ND_NEIGHBOR_SOLICIT:
 773                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 774                 if (code != 0)
 775                         goto badcode;
 776                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 777                         goto badlen;
 778                 if (send_sendso_input_hook != NULL) {
 779                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 780                         if (error == 0) {
 781                                 m = NULL;
 782                                 goto freeit;
 783                         }
 784                 }
 785                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 786                 nd6_ns_input(m, off, icmp6len);
 787                 m = n;
 788                 if (m == NULL)
 789                         goto freeit;
 790                 break;
 791
 792         case ND_NEIGHBOR_ADVERT:
 793                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 794                 if (code != 0)
 795                         goto badcode;
 796                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 797                         goto badlen;
 798                 if (send_sendso_input_hook != NULL) {
 799                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 800                         if (error == 0) {
 801                                 m = NULL;
 802                                 goto freeit;
 803                         }
 804                 }
 805                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 806                 nd6_na_input(m, off, icmp6len);
 807                 m = n;
 808                 if (m == NULL)
 809                         goto freeit;
 810                 break;
 811
 812         case ND_REDIRECT:
 813                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 814                 if (code != 0)
 815                         goto badcode;
 816                 if (icmp6len < sizeof(struct nd_redirect))
 817                         goto badlen;
 818                 if (send_sendso_input_hook != NULL) {
 819                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 820                         if (error == 0) {
 821                                 m = NULL;
 822                                 goto freeit;
 823                         }
 824                 }
 825                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 826                 icmp6_redirect_input(m, off);
 827                 m = n;
 828                 if (m == NULL)
 829                         goto freeit;
 830                 break;
 831
 832         case ICMP6_ROUTER_RENUMBERING:
 833                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 834                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 835                         goto badcode;
 836                 if (icmp6len < sizeof(struct icmp6_router_renum))
 837                         goto badlen;
 838                 break;
 839
 840         default:
 841                 nd6log((LOG_DEBUG,
 842                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 843                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 844                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 845                     ifp ? ifp->if_index : 0));
 846                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 847                         /* ICMPv6 error: MUST deliver it by spec... */
 848                         code = PRC_NCMDS;
 849                         /* deliver */
 850                 } else {
 851                         /* ICMPv6 informational: MUST not deliver */
 852                         break;
 853                 }
 854         deliver:
 855                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 856                         /* In this case, m should've been freed. */
 857                         return (IPPROTO_DONE);
 858                 }
 859                 break;
 860
 861         badcode:
 862                 ICMP6STAT_INC(icp6s_badcode);
 863                 break;
 864
 865         badlen:
 866                 ICMP6STAT_INC(icp6s_badlen);
 867                 break;
 868         }
 869
 870         /* deliver the packet to appropriate sockets */
 871         icmp6_rip6_input(&m, *offp);
 872
 873         return IPPROTO_DONE;
 874
 875  freeit:
 876         m_freem(m);
 877         return IPPROTO_DONE;
 878 }
 879
 880 static int
 881 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 882 {
 883         struct mbuf *m = *mp;
 884         struct icmp6_hdr *icmp6;
 885         struct ip6_hdr *eip6;
 886         u_int32_t notifymtu;
 887         struct sockaddr_in6 icmp6src, icmp6dst;
 888
 889         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 890                 ICMP6STAT_INC(icp6s_tooshort);
 891                 goto freeit;
 892         }
 893 #ifndef PULLDOWN_TEST
 894         IP6_EXTHDR_CHECK(m, off,
 895             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 896         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 897 #else
 898         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 899             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 900         if (icmp6 == NULL) {
 901                 ICMP6STAT_INC(icp6s_tooshort);
 902                 return (-1);
 903         }
 904 #endif
 905         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 906
 907         /* Detect the upper level protocol */
 908         {
 909                 void (*ctlfunc)(int, struct sockaddr *, void *);
 910                 u_int8_t nxt = eip6->ip6_nxt;
 911                 int eoff = off + sizeof(struct icmp6_hdr) +
 912                     sizeof(struct ip6_hdr);
 913                 struct ip6ctlparam ip6cp;
 914                 struct in6_addr *finaldst = NULL;
 915                 int icmp6type = icmp6->icmp6_type;
 916                 struct ip6_frag *fh;
 917                 struct ip6_rthdr *rth;
 918                 struct ip6_rthdr0 *rth0;
 919                 int rthlen;
 920
 921                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 922                         struct ip6_ext *eh;
 923
 924                         switch (nxt) {
 925                         case IPPROTO_HOPOPTS:
 926                         case IPPROTO_DSTOPTS:
 927                         case IPPROTO_AH:
 928 #ifndef PULLDOWN_TEST
 929                                 IP6_EXTHDR_CHECK(m, 0,
 930                                     eoff + sizeof(struct ip6_ext), -1);
 931                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 932 #else
 933                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 934                                     eoff, sizeof(*eh));
 935                                 if (eh == NULL) {
 936                                         ICMP6STAT_INC(icp6s_tooshort);
 937                                         return (-1);
 938                                 }
 939 #endif
 940
 941                                 if (nxt == IPPROTO_AH)
 942                                         eoff += (eh->ip6e_len + 2) << 2;
 943                                 else
 944                                         eoff += (eh->ip6e_len + 1) << 3;
 945                                 nxt = eh->ip6e_nxt;
 946                                 break;
 947                         case IPPROTO_ROUTING:
 948                                 /*
 949                                  * When the erroneous packet contains a
 950                                  * routing header, we should examine the
 951                                  * header to determine the final destination.
 952                                  * Otherwise, we can't properly update
 953                                  * information that depends on the final
 954                                  * destination (e.g. path MTU).
 955                                  */
 956 #ifndef PULLDOWN_TEST
 957                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 958                                 rth = (struct ip6_rthdr *)
 959                                     (mtod(m, caddr_t) + eoff);
 960 #else
 961                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 962                                     eoff, sizeof(*rth));
 963                                 if (rth == NULL) {
 964                                         ICMP6STAT_INC(icp6s_tooshort);
 965                                         return (-1);
 966                                 }
 967 #endif
 968                                 rthlen = (rth->ip6r_len + 1) << 3;
 969                                 /*
 970                                  * XXX: currently there is no
 971                                  * officially defined type other
 972                                  * than type-0.
 973                                  * Note that if the segment left field
 974                                  * is 0, all intermediate hops must
 975                                  * have been passed.
 976                                  */
 977                                 if (rth->ip6r_segleft &&
 978                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 979                                         int hops;
 980
 981 #ifndef PULLDOWN_TEST
 982                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 983                                         rth0 = (struct ip6_rthdr0 *)
 984                                             (mtod(m, caddr_t) + eoff);
 985 #else
 986                                         IP6_EXTHDR_GET(rth0,
 987                                             struct ip6_rthdr0 *, m,
 988                                             eoff, rthlen);
 989                                         if (rth0 == NULL) {
 990                                                 ICMP6STAT_INC(icp6s_tooshort);
 991                                                 return (-1);
 992                                         }
 993 #endif
 994                                         /* just ignore a bogus header */
 995                                         if ((rth0->ip6r0_len % 2) == 0 &&
 996                                             (hops = rth0->ip6r0_len/2))
 997                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 998                                 }
 999                                 eoff += rthlen;
1000                                 nxt = rth->ip6r_nxt;
1001                                 break;
1002                         case IPPROTO_FRAGMENT:
1003 #ifndef PULLDOWN_TEST
1004                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1005                                     sizeof(struct ip6_frag), -1);
1006                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1007                                     eoff);
1008 #else
1009                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1010                                     eoff, sizeof(*fh));
1011                                 if (fh == NULL) {
1012                                         ICMP6STAT_INC(icp6s_tooshort);
1013                                         return (-1);
1014                                 }
1015 #endif
1016                                 /*
1017                                  * Data after a fragment header is meaningless
1018                                  * unless it is the first fragment, but
1019                                  * we'll go to the notify label for path MTU
1020                                  * discovery.
1021                                  */
1022                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1023                                         goto notify;
1024
1025                                 eoff += sizeof(struct ip6_frag);
1026                                 nxt = fh->ip6f_nxt;
1027                                 break;
1028                         default:
1029                                 /*
1030                                  * This case includes ESP and the No Next
1031                                  * Header.  In such cases going to the notify
1032                                  * label does not have any meaning
1033                                  * (i.e. ctlfunc will be NULL), but we go
1034                                  * anyway since we might have to update
1035                                  * path MTU information.
1036                                  */
1037                                 goto notify;
1038                         }
1039                 }
1040           notify:
1041 #ifndef PULLDOWN_TEST
1042                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1043 #else
1044                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1045                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1046                 if (icmp6 == NULL) {
1047                         ICMP6STAT_INC(icp6s_tooshort);
1048                         return (-1);
1049                 }
1050 #endif
1051
1052                 /*
1053                  * retrieve parameters from the inner IPv6 header, and convert
1054                  * them into sockaddr structures.
1055                  * XXX: there is no guarantee that the source or destination
1056                  * addresses of the inner packet are in the same scope as
1057                  * the addresses of the icmp packet.  But there is no other
1058                  * way to determine the zone.
1059                  */
1060                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1061
1062                 bzero(&icmp6dst, sizeof(icmp6dst));
1063                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1064                 icmp6dst.sin6_family = AF_INET6;
1065                 if (finaldst == NULL)
1066                         icmp6dst.sin6_addr = eip6->ip6_dst;
1067                 else
1068                         icmp6dst.sin6_addr = *finaldst;
1069                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1070                         goto freeit;
1071                 bzero(&icmp6src, sizeof(icmp6src));
1072                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1073                 icmp6src.sin6_family = AF_INET6;
1074                 icmp6src.sin6_addr = eip6->ip6_src;
1075                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1076                         goto freeit;
1077                 icmp6src.sin6_flowinfo =
1078                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1079
1080                 if (finaldst == NULL)
1081                         finaldst = &eip6->ip6_dst;
1082                 ip6cp.ip6c_m = m;
1083                 ip6cp.ip6c_icmp6 = icmp6;
1084                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1085                 ip6cp.ip6c_off = eoff;
1086                 ip6cp.ip6c_finaldst = finaldst;
1087                 ip6cp.ip6c_src = &icmp6src;
1088                 ip6cp.ip6c_nxt = nxt;
1089
1090                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1091                         notifymtu = ntohl(icmp6->icmp6_mtu);
1092                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1093                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1094                 }
1095
1096                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1097                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1098                 if (ctlfunc) {
1099                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1100                             &ip6cp);
1101                 }
1102         }
1103         *mp = m;
1104         return (0);
1105
1106   freeit:
1107         m_freem(m);
1108         return (-1);
1109 }
1110
1111 void
1112 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1113 {
1114         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1115         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1116         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1117         u_int mtu = ntohl(icmp6->icmp6_mtu);
1118         struct in_conninfo inc;
1119
1120 #if 0
1121         /*
1122          * RFC2460 section 5, last paragraph.
1123          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1124          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1125          * due to packet translator in the middle.
1126          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1127          * special handling.
1128          */
1129         if (mtu < IPV6_MMTU)
1130                 return;
1131 #endif
1132
1133         /*
1134          * we reject ICMPv6 too big with abnormally small value.
1135          * XXX what is the good definition of "abnormally small"?
1136          */
1137         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1138                 return;
1139
1140         if (!validated)
1141                 return;
1142
1143         /*
1144          * In case the suggested mtu is less than IPV6_MMTU, we
1145          * only need to remember that it was for above mentioned
1146          * "alwaysfrag" case.
1147          * Try to be as close to the spec as possible.
1148          */
1149         if (mtu < IPV6_MMTU)
1150                 mtu = IPV6_MMTU - 8;
1151
1152         bzero(&inc, sizeof(inc));
1153         inc.inc_fibnum = M_GETFIB(m);
1154         inc.inc_flags |= INC_ISIPV6;
1155         inc.inc6_faddr = *dst;
1156         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1157                 return;
1158
1159         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1160                 tcp_hc_updatemtu(&inc, mtu);
1161                 ICMP6STAT_INC(icp6s_pmtuchg);
1162         }
1163 }
1164
1165 /*
1166  * Process a Node Information Query packet, based on
1167  * draft-ietf-ipngwg-icmp-name-lookups-07.
1168  *
1169  * Spec incompatibilities:
1170  * - IPv6 Subject address handling
1171  * - IPv4 Subject address handling support missing
1172  * - Proxy reply (answer even if it's not for me)
1173  * - joins NI group address at in6_ifattach() time only, does not cope
1174  *   with hostname changes by sethostname(3)
1175  */
1176 static struct mbuf *
1177 ni6_input(struct mbuf *m, int off)
1178 {
1179         struct icmp6_nodeinfo *ni6, *nni6;
1180         struct mbuf *n = NULL;
1181         struct prison *pr;
1182         u_int16_t qtype;
1183         int subjlen;
1184         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1185         struct ni_reply_fqdn *fqdn;
1186         int addrs;              /* for NI_QTYPE_NODEADDR */
1187         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1188         struct in6_addr in6_subj; /* subject address */
1189         struct ip6_hdr *ip6;
1190         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1191         char *subj = NULL;
1192         struct in6_ifaddr *ia6 = NULL;
1193
1194         ip6 = mtod(m, struct ip6_hdr *);
1195 #ifndef PULLDOWN_TEST
1196         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1197 #else
1198         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1199         if (ni6 == NULL) {
1200                 /* m is already reclaimed */
1201                 return (NULL);
1202         }
1203 #endif
1204
1205         /*
1206          * Validate IPv6 source address.
1207          * The default configuration MUST be to refuse answering queries from
1208          * global-scope addresses according to RFC4602.
1209          * Notes:
1210          *  - it's not very clear what "refuse" means; this implementation
1211          *    simply drops it.
1212          *  - it's not very easy to identify global-scope (unicast) addresses
1213          *    since there are many prefixes for them.  It should be safer
1214          *    and in practice sufficient to check "all" but loopback and
1215          *    link-local (note that site-local unicast was deprecated and
1216          *    ULA is defined as global scope-wise)
1217          */
1218         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1219             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1220             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1221                 goto bad;
1222
1223         /*
1224          * Validate IPv6 destination address.
1225          *
1226          * The Responder must discard the Query without further processing
1227          * unless it is one of the Responder's unicast or anycast addresses, or
1228          * a link-local scope multicast address which the Responder has joined.
1229          * [RFC4602, Section 5.]
1230          */
1231         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1232                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1233                         goto bad;
1234                 /* else it's a link-local multicast, fine */
1235         } else {                /* unicast or anycast */
1236                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1237                 if (ia6 == NULL)
1238                         goto bad; /* XXX impossible */
1239
1240                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1241                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1242                         ifa_free(&ia6->ia_ifa);
1243                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1244                                 "a temporary address in %s:%d",
1245                                __FILE__, __LINE__));
1246                         goto bad;
1247                 }
1248                 ifa_free(&ia6->ia_ifa);
1249         }
1250
1251         /* validate query Subject field. */
1252         qtype = ntohs(ni6->ni_qtype);
1253         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1254         switch (qtype) {
1255         case NI_QTYPE_NOOP:
1256         case NI_QTYPE_SUPTYPES:
1257                 /* 07 draft */
1258                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1259                         break;
1260                 /* FALLTHROUGH */
1261         case NI_QTYPE_FQDN:
1262         case NI_QTYPE_NODEADDR:
1263         case NI_QTYPE_IPV4ADDR:
1264                 switch (ni6->ni_code) {
1265                 case ICMP6_NI_SUBJ_IPV6:
1266 #if ICMP6_NI_SUBJ_IPV6 != 0
1267                 case 0:
1268 #endif
1269                         /*
1270                          * backward compatibility - try to accept 03 draft
1271                          * format, where no Subject is present.
1272                          */
1273                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1274                             subjlen == 0) {
1275                                 oldfqdn++;
1276                                 break;
1277                         }
1278 #if ICMP6_NI_SUBJ_IPV6 != 0
1279                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1280                                 goto bad;
1281 #endif
1282
1283                         if (subjlen != sizeof(struct in6_addr))
1284                                 goto bad;
1285
1286                         /*
1287                          * Validate Subject address.
1288                          *
1289                          * Not sure what exactly "address belongs to the node"
1290                          * means in the spec, is it just unicast, or what?
1291                          *
1292                          * At this moment we consider Subject address as
1293                          * "belong to the node" if the Subject address equals
1294                          * to the IPv6 destination address; validation for
1295                          * IPv6 destination address should have done enough
1296                          * check for us.
1297                          *
1298                          * We do not do proxy at this moment.
1299                          */
1300                         /* m_pulldown instead of copy? */
1301                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1302                             subjlen, (caddr_t)&in6_subj);
1303                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1304                                 goto bad;
1305
1306                         subj = (char *)&in6_subj;
1307                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1308                                 break;
1309
1310                         /*
1311                          * XXX if we are to allow other cases, we should really
1312                          * be careful about scope here.
1313                          * basically, we should disallow queries toward IPv6
1314                          * destination X with subject Y,
1315                          * if scope(X) > scope(Y).
1316                          * if we allow scope(X) > scope(Y), it will result in
1317                          * information leakage across scope boundary.
1318                          */
1319                         goto bad;
1320
1321                 case ICMP6_NI_SUBJ_FQDN:
1322                         /*
1323                          * Validate Subject name with gethostname(3).
1324                          *
1325                          * The behavior may need some debate, since:
1326                          * - we are not sure if the node has FQDN as
1327                          *   hostname (returned by gethostname(3)).
1328                          * - the code does wildcard match for truncated names.
1329                          *   however, we are not sure if we want to perform
1330                          *   wildcard match, if gethostname(3) side has
1331                          *   truncated hostname.
1332                          */
1333                         pr = curthread->td_ucred->cr_prison;
1334                         mtx_lock(&pr->pr_mtx);
1335                         n = ni6_nametodns(pr->pr_hostname,
1336                             strlen(pr->pr_hostname), 0);
1337                         mtx_unlock(&pr->pr_mtx);
1338                         if (!n || n->m_next || n->m_len == 0)
1339                                 goto bad;
1340                         IP6_EXTHDR_GET(subj, char *, m,
1341                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1342                         if (subj == NULL)
1343                                 goto bad;
1344                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1345                             n->m_len)) {
1346                                 goto bad;
1347                         }
1348                         m_freem(n);
1349                         n = NULL;
1350                         break;
1351
1352                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1353                 default:
1354                         goto bad;
1355                 }
1356                 break;
1357         }
1358
1359         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1360         switch (qtype) {
1361         case NI_QTYPE_FQDN:
1362                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1363                         goto bad;
1364                 break;
1365         case NI_QTYPE_NODEADDR:
1366         case NI_QTYPE_IPV4ADDR:
1367                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1368                         goto bad;
1369                 break;
1370         }
1371
1372         /* guess reply length */
1373         switch (qtype) {
1374         case NI_QTYPE_NOOP:
1375                 break;          /* no reply data */
1376         case NI_QTYPE_SUPTYPES:
1377                 replylen += sizeof(u_int32_t);
1378                 break;
1379         case NI_QTYPE_FQDN:
1380                 /* XXX will append an mbuf */
1381                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1382                 break;
1383         case NI_QTYPE_NODEADDR:
1384                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1385                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1386                     sizeof(u_int32_t))) > MCLBYTES)
1387                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1388                 break;
1389         case NI_QTYPE_IPV4ADDR:
1390                 /* unsupported - should respond with unknown Qtype? */
1391                 break;
1392         default:
1393                 /*
1394                  * XXX: We must return a reply with the ICMP6 code
1395                  * `unknown Qtype' in this case.  However we regard the case
1396                  * as an FQDN query for backward compatibility.
1397                  * Older versions set a random value to this field,
1398                  * so it rarely varies in the defined qtypes.
1399                  * But the mechanism is not reliable...
1400                  * maybe we should obsolete older versions.
1401                  */
1402                 qtype = NI_QTYPE_FQDN;
1403                 /* XXX will append an mbuf */
1404                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1405                 oldfqdn++;
1406                 break;
1407         }
1408
1409         /* Allocate an mbuf to reply. */
1410         if (replylen > MCLBYTES) {
1411                 /*
1412                  * XXX: should we try to allocate more? But MCLBYTES
1413                  * is probably much larger than IPV6_MMTU...
1414                  */
1415                 goto bad;
1416         }
1417         if (replylen > MHLEN)
1418                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1419         else
1420                 n = m_gethdr(M_NOWAIT, m->m_type);
1421         if (n == NULL) {
1422                 m_freem(m);
1423                 return (NULL);
1424         }
1425         m_move_pkthdr(n, m); /* just for recvif and FIB */
1426         n->m_pkthdr.len = n->m_len = replylen;
1427
1428         /* copy mbuf header and IPv6 + Node Information base headers */
1429         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1430         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1431         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1432
1433         /* qtype dependent procedure */
1434         switch (qtype) {
1435         case NI_QTYPE_NOOP:
1436                 nni6->ni_code = ICMP6_NI_SUCCESS;
1437                 nni6->ni_flags = 0;
1438                 break;
1439         case NI_QTYPE_SUPTYPES:
1440         {
1441                 u_int32_t v;
1442                 nni6->ni_code = ICMP6_NI_SUCCESS;
1443                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1444                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1445                 v = (u_int32_t)htonl(0x0000000f);
1446                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1447                 break;
1448         }
1449         case NI_QTYPE_FQDN:
1450                 nni6->ni_code = ICMP6_NI_SUCCESS;
1451                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1452                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1453                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1454                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1455                 /*
1456                  * XXX do we really have FQDN in hostname?
1457                  */
1458                 pr = curthread->td_ucred->cr_prison;
1459                 mtx_lock(&pr->pr_mtx);
1460                 n->m_next = ni6_nametodns(pr->pr_hostname,
1461                     strlen(pr->pr_hostname), oldfqdn);
1462                 mtx_unlock(&pr->pr_mtx);
1463                 if (n->m_next == NULL)
1464                         goto bad;
1465                 /* XXX we assume that n->m_next is not a chain */
1466                 if (n->m_next->m_next != NULL)
1467                         goto bad;
1468                 n->m_pkthdr.len += n->m_next->m_len;
1469                 break;
1470         case NI_QTYPE_NODEADDR:
1471         {
1472                 int lenlim, copied;
1473
1474                 nni6->ni_code = ICMP6_NI_SUCCESS;
1475                 n->m_pkthdr.len = n->m_len =
1476                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1477                 lenlim = M_TRAILINGSPACE(n);
1478                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1479                 /* XXX: reset mbuf length */
1480                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1481                     sizeof(struct icmp6_nodeinfo) + copied;
1482                 break;
1483         }
1484         default:
1485                 break;          /* XXX impossible! */
1486         }
1487
1488         nni6->ni_type = ICMP6_NI_REPLY;
1489         m_freem(m);
1490         return (n);
1491
1492   bad:
1493         m_freem(m);
1494         if (n)
1495                 m_freem(n);
1496         return (NULL);
1497 }
1498
1499 /*
1500  * make a mbuf with DNS-encoded string.  no compression support.
1501  *
1502  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1503  * treated as truncated name (two \0 at the end).  this is a wild guess.
1504  *
1505  * old - return pascal string if non-zero
1506  */
1507 static struct mbuf *
1508 ni6_nametodns(const char *name, int namelen, int old)
1509 {
1510         struct mbuf *m;
1511         char *cp, *ep;
1512         const char *p, *q;
1513         int i, len, nterm;
1514
1515         if (old)
1516                 len = namelen + 1;
1517         else
1518                 len = MCLBYTES;
1519
1520         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1521         if (len > MLEN)
1522                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1523         else
1524                 m = m_get(M_NOWAIT, MT_DATA);
1525         if (m == NULL)
1526                 goto fail;
1527
1528         if (old) {
1529                 m->m_len = len;
1530                 *mtod(m, char *) = namelen;
1531                 bcopy(name, mtod(m, char *) + 1, namelen);
1532                 return m;
1533         } else {
1534                 m->m_len = 0;
1535                 cp = mtod(m, char *);
1536                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1537
1538                 /* if not certain about my name, return empty buffer */
1539                 if (namelen == 0)
1540                         return m;
1541
1542                 /*
1543                  * guess if it looks like shortened hostname, or FQDN.
1544                  * shortened hostname needs two trailing "\0".
1545                  */
1546                 i = 0;
1547                 for (p = name; p < name + namelen; p++) {
1548                         if (*p && *p == '.')
1549                                 i++;
1550                 }
1551                 if (i < 2)
1552                         nterm = 2;
1553                 else
1554                         nterm = 1;
1555
1556                 p = name;
1557                 while (cp < ep && p < name + namelen) {
1558                         i = 0;
1559                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1560                                 i++;
1561                         /* result does not fit into mbuf */
1562                         if (cp + i + 1 >= ep)
1563                                 goto fail;
1564                         /*
1565                          * DNS label length restriction, RFC1035 page 8.
1566                          * "i == 0" case is included here to avoid returning
1567                          * 0-length label on "foo..bar".
1568                          */
1569                         if (i <= 0 || i >= 64)
1570                                 goto fail;
1571                         *cp++ = i;
1572                         bcopy(p, cp, i);
1573                         cp += i;
1574                         p = q;
1575                         if (p < name + namelen && *p == '.')
1576                                 p++;
1577                 }
1578                 /* termination */
1579                 if (cp + nterm >= ep)
1580                         goto fail;
1581                 while (nterm-- > 0)
1582                         *cp++ = '\0';
1583                 m->m_len = cp - mtod(m, char *);
1584                 return m;
1585         }
1586
1587         panic("should not reach here");
1588         /* NOTREACHED */
1589
1590  fail:
1591         if (m)
1592                 m_freem(m);
1593         return NULL;
1594 }
1595
1596 /*
1597  * check if two DNS-encoded string matches.  takes care of truncated
1598  * form (with \0\0 at the end).  no compression support.
1599  * XXX upper/lowercase match (see RFC2065)
1600  */
1601 static int
1602 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1603 {
1604         const char *a0, *b0;
1605         int l;
1606
1607         /* simplest case - need validation? */
1608         if (alen == blen && bcmp(a, b, alen) == 0)
1609                 return 1;
1610
1611         a0 = a;
1612         b0 = b;
1613
1614         /* termination is mandatory */
1615         if (alen < 2 || blen < 2)
1616                 return 0;
1617         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1618                 return 0;
1619         alen--;
1620         blen--;
1621
1622         while (a - a0 < alen && b - b0 < blen) {
1623                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1624                         return 0;
1625
1626                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1627                         return 0;
1628                 /* we don't support compression yet */
1629                 if (a[0] >= 64 || b[0] >= 64)
1630                         return 0;
1631
1632                 /* truncated case */
1633                 if (a[0] == 0 && a - a0 == alen - 1)
1634                         return 1;
1635                 if (b[0] == 0 && b - b0 == blen - 1)
1636                         return 1;
1637                 if (a[0] == 0 || b[0] == 0)
1638                         return 0;
1639
1640                 if (a[0] != b[0])
1641                         return 0;
1642                 l = a[0];
1643                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1644                         return 0;
1645                 if (bcmp(a + 1, b + 1, l) != 0)
1646                         return 0;
1647
1648                 a += 1 + l;
1649                 b += 1 + l;
1650         }
1651
1652         if (a - a0 == alen && b - b0 == blen)
1653                 return 1;
1654         else
1655                 return 0;
1656 }
1657
1658 /*
1659  * calculate the number of addresses to be returned in the node info reply.
1660  */
1661 static int
1662 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1663     struct in6_addr *subj)
1664 {
1665         struct ifnet *ifp;
1666         struct in6_ifaddr *ifa6;
1667         struct ifaddr *ifa;
1668         int addrs = 0, addrsofif, iffound = 0;
1669         int niflags = ni6->ni_flags;
1670
1671         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1672                 switch (ni6->ni_code) {
1673                 case ICMP6_NI_SUBJ_IPV6:
1674                         if (subj == NULL) /* must be impossible... */
1675                                 return (0);
1676                         break;
1677                 default:
1678                         /*
1679                          * XXX: we only support IPv6 subject address for
1680                          * this Qtype.
1681                          */
1682                         return (0);
1683                 }
1684         }
1685
1686         IFNET_RLOCK_NOSLEEP();
1687         TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1688                 addrsofif = 0;
1689                 IF_ADDR_RLOCK(ifp);
1690                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1691                         if (ifa->ifa_addr->sa_family != AF_INET6)
1692                                 continue;
1693                         ifa6 = (struct in6_ifaddr *)ifa;
1694
1695                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1696                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1697                                 iffound = 1;
1698
1699                         /*
1700                          * IPv4-mapped addresses can only be returned by a
1701                          * Node Information proxy, since they represent
1702                          * addresses of IPv4-only nodes, which perforce do
1703                          * not implement this protocol.
1704                          * [icmp-name-lookups-07, Section 5.4]
1705                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1706                          * this function at this moment.
1707                          */
1708
1709                         /* What do we have to do about ::1? */
1710                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1711                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1712                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1713                                         continue;
1714                                 break;
1715                         case IPV6_ADDR_SCOPE_SITELOCAL:
1716                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1717                                         continue;
1718                                 break;
1719                         case IPV6_ADDR_SCOPE_GLOBAL:
1720                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1721                                         continue;
1722                                 break;
1723                         default:
1724                                 continue;
1725                         }
1726
1727                         /*
1728                          * check if anycast is okay.
1729                          * XXX: just experimental.  not in the spec.
1730                          */
1731                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1732                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1733                                 continue; /* we need only unicast addresses */
1734                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1735                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1736                                 continue;
1737                         }
1738                         addrsofif++; /* count the address */
1739                 }
1740                 IF_ADDR_RUNLOCK(ifp);
1741                 if (iffound) {
1742                         *ifpp = ifp;
1743                         IFNET_RUNLOCK_NOSLEEP();
1744                         return (addrsofif);
1745                 }
1746
1747                 addrs += addrsofif;
1748         }
1749         IFNET_RUNLOCK_NOSLEEP();
1750
1751         return (addrs);
1752 }
1753
1754 static int
1755 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1756     struct ifnet *ifp0, int resid)
1757 {
1758         struct ifnet *ifp;
1759         struct in6_ifaddr *ifa6;
1760         struct ifaddr *ifa;
1761         struct ifnet *ifp_dep = NULL;
1762         int copied = 0, allow_deprecated = 0;
1763         u_char *cp = (u_char *)(nni6 + 1);
1764         int niflags = ni6->ni_flags;
1765         u_int32_t ltime;
1766
1767         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1768                 return (0);     /* needless to copy */
1769
1770         IFNET_RLOCK_NOSLEEP();
1771         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1772   again:
1773
1774         for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) {
1775                 IF_ADDR_RLOCK(ifp);
1776                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1777                         if (ifa->ifa_addr->sa_family != AF_INET6)
1778                                 continue;
1779                         ifa6 = (struct in6_ifaddr *)ifa;
1780
1781                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1782                             allow_deprecated == 0) {
1783                                 /*
1784                                  * prefererred address should be put before
1785                                  * deprecated addresses.
1786                                  */
1787
1788                                 /* record the interface for later search */
1789                                 if (ifp_dep == NULL)
1790                                         ifp_dep = ifp;
1791
1792                                 continue;
1793                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1794                             allow_deprecated != 0)
1795                                 continue; /* we now collect deprecated addrs */
1796
1797                         /* What do we have to do about ::1? */
1798                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1799                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1800                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1801                                         continue;
1802                                 break;
1803                         case IPV6_ADDR_SCOPE_SITELOCAL:
1804                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1805                                         continue;
1806                                 break;
1807                         case IPV6_ADDR_SCOPE_GLOBAL:
1808                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1809                                         continue;
1810                                 break;
1811                         default:
1812                                 continue;
1813                         }
1814
1815                         /*
1816                          * check if anycast is okay.
1817                          * XXX: just experimental.  not in the spec.
1818                          */
1819                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1820                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1821                                 continue;
1822                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1823                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1824                                 continue;
1825                         }
1826
1827                         /* now we can copy the address */
1828                         if (resid < sizeof(struct in6_addr) +
1829                             sizeof(u_int32_t)) {
1830                                 IF_ADDR_RUNLOCK(ifp);
1831                                 /*
1832                                  * We give up much more copy.
1833                                  * Set the truncate flag and return.
1834                                  */
1835                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1836                                 IFNET_RUNLOCK_NOSLEEP();
1837                                 return (copied);
1838                         }
1839
1840                         /*
1841                          * Set the TTL of the address.
1842                          * The TTL value should be one of the following
1843                          * according to the specification:
1844                          *
1845                          * 1. The remaining lifetime of a DHCP lease on the
1846                          *    address, or
1847                          * 2. The remaining Valid Lifetime of a prefix from
1848                          *    which the address was derived through Stateless
1849                          *    Autoconfiguration.
1850                          *
1851                          * Note that we currently do not support stateful
1852                          * address configuration by DHCPv6, so the former
1853                          * case can't happen.
1854                          */
1855                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1856                                 ltime = ND6_INFINITE_LIFETIME;
1857                         else {
1858                                 if (ifa6->ia6_lifetime.ia6t_expire >
1859                                     time_uptime)
1860                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1861                                 else
1862                                         ltime = 0;
1863                         }
1864
1865                         bcopy(&ltime, cp, sizeof(u_int32_t));
1866                         cp += sizeof(u_int32_t);
1867
1868                         /* copy the address itself */
1869                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1870                             sizeof(struct in6_addr));
1871                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1872                         cp += sizeof(struct in6_addr);
1873
1874                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1875                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1876                 }
1877                 IF_ADDR_RUNLOCK(ifp);
1878                 if (ifp0)       /* we need search only on the specified IF */
1879                         break;
1880         }
1881
1882         if (allow_deprecated == 0 && ifp_dep != NULL) {
1883                 ifp = ifp_dep;
1884                 allow_deprecated = 1;
1885
1886                 goto again;
1887         }
1888
1889         IFNET_RUNLOCK_NOSLEEP();
1890
1891         return (copied);
1892 }
1893
1894 /*
1895  * XXX almost dup'ed code with rip6_input.
1896  */
1897 static int
1898 icmp6_rip6_input(struct mbuf **mp, int off)
1899 {
1900         struct mbuf *m = *mp;
1901         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1902         struct inpcb *in6p;
1903         struct inpcb *last = NULL;
1904         struct sockaddr_in6 fromsa;
1905         struct icmp6_hdr *icmp6;
1906         struct mbuf *opts = NULL;
1907
1908 #ifndef PULLDOWN_TEST
1909         /* this is assumed to be safe. */
1910         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1911 #else
1912         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1913         if (icmp6 == NULL) {
1914                 /* m is already reclaimed */
1915                 return (IPPROTO_DONE);
1916         }
1917 #endif
1918
1919         /*
1920          * XXX: the address may have embedded scope zone ID, which should be
1921          * hidden from applications.
1922          */
1923         bzero(&fromsa, sizeof(fromsa));
1924         fromsa.sin6_family = AF_INET6;
1925         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1926         fromsa.sin6_addr = ip6->ip6_src;
1927         if (sa6_recoverscope(&fromsa)) {
1928                 m_freem(m);
1929                 return (IPPROTO_DONE);
1930         }
1931
1932         INP_INFO_RLOCK(&V_ripcbinfo);
1933         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1934                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1935                         continue;
1936                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1937                         continue;
1938                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1939                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1940                         continue;
1941                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1942                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1943                         continue;
1944                 INP_RLOCK(in6p);
1945                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1946                     in6p->in6p_icmp6filt)) {
1947                         INP_RUNLOCK(in6p);
1948                         continue;
1949                 }
1950                 if (last != NULL) {
1951                         struct  mbuf *n = NULL;
1952
1953                         /*
1954                          * Recent network drivers tend to allocate a single
1955                          * mbuf cluster, rather than to make a couple of
1956                          * mbufs without clusters.  Also, since the IPv6 code
1957                          * path tries to avoid m_pullup(), it is highly
1958                          * probable that we still have an mbuf cluster here
1959                          * even though the necessary length can be stored in an
1960                          * mbuf's internal buffer.
1961                          * Meanwhile, the default size of the receive socket
1962                          * buffer for raw sockets is not so large.  This means
1963                          * the possibility of packet loss is relatively higher
1964                          * than before.  To avoid this scenario, we copy the
1965                          * received data to a separate mbuf that does not use
1966                          * a cluster, if possible.
1967                          * XXX: it is better to copy the data after stripping
1968                          * intermediate headers.
1969                          */
1970                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1971                             m->m_len <= MHLEN) {
1972                                 n = m_get(M_NOWAIT, m->m_type);
1973                                 if (n != NULL) {
1974                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1975                                                 bcopy(m->m_data, n->m_data,
1976                                                       m->m_len);
1977                                                 n->m_len = m->m_len;
1978                                         } else {
1979                                                 m_free(n);
1980                                                 n = NULL;
1981                                         }
1982                                 }
1983                         }
1984                         if (n != NULL ||
1985                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1986                                 if (last->inp_flags & INP_CONTROLOPTS)
1987                                         ip6_savecontrol(last, n, &opts);
1988                                 /* strip intermediate headers */
1989                                 m_adj(n, off);
1990                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
1991                                 if (sbappendaddr_locked(
1992                                     &last->inp_socket->so_rcv,
1993                                     (struct sockaddr *)&fromsa, n, opts)
1994                                     == 0) {
1995                                         /* should notify about lost packet */
1996                                         m_freem(n);
1997                                         if (opts) {
1998                                                 m_freem(opts);
1999                                         }
2000                                         SOCKBUF_UNLOCK(
2001                                             &last->inp_socket->so_rcv);
2002                                 } else
2003                                         sorwakeup_locked(last->inp_socket);
2004                                 opts = NULL;
2005                         }
2006                         INP_RUNLOCK(last);
2007                 }
2008                 last = in6p;
2009         }
2010         INP_INFO_RUNLOCK(&V_ripcbinfo);
2011         if (last != NULL) {
2012                 if (last->inp_flags & INP_CONTROLOPTS)
2013                         ip6_savecontrol(last, m, &opts);
2014                 /* strip intermediate headers */
2015                 m_adj(m, off);
2016
2017                 /* avoid using mbuf clusters if possible (see above) */
2018                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2019                     m->m_len <= MHLEN) {
2020                         struct mbuf *n;
2021
2022                         n = m_get(M_NOWAIT, m->m_type);
2023                         if (n != NULL) {
2024                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2025                                         bcopy(m->m_data, n->m_data, m->m_len);
2026                                         n->m_len = m->m_len;
2027
2028                                         m_freem(m);
2029                                         m = n;
2030                                 } else {
2031                                         m_freem(n);
2032                                         n = NULL;
2033                                 }
2034                         }
2035                 }
2036                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2037                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2038                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2039                         m_freem(m);
2040                         if (opts)
2041                                 m_freem(opts);
2042                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2043                 } else
2044                         sorwakeup_locked(last->inp_socket);
2045                 INP_RUNLOCK(last);
2046         } else {
2047                 m_freem(m);
2048                 IP6STAT_DEC(ip6s_delivered);
2049         }
2050         return IPPROTO_DONE;
2051 }
2052
2053 /*
2054  * Reflect the ip6 packet back to the source.
2055  * OFF points to the icmp6 header, counted from the top of the mbuf.
2056  */
2057 void
2058 icmp6_reflect(struct mbuf *m, size_t off)
2059 {
2060         struct in6_addr src6, *srcp;
2061         struct ip6_hdr *ip6;
2062         struct icmp6_hdr *icmp6;
2063         struct in6_ifaddr *ia = NULL;
2064         struct ifnet *outif = NULL;
2065         int plen;
2066         int type, code, hlim;
2067
2068         /* too short to reflect */
2069         if (off < sizeof(struct ip6_hdr)) {
2070                 nd6log((LOG_DEBUG,
2071                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2072                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2073                     __FILE__, __LINE__));
2074                 goto bad;
2075         }
2076
2077         /*
2078          * If there are extra headers between IPv6 and ICMPv6, strip
2079          * off that header first.
2080          */
2081 #ifdef DIAGNOSTIC
2082         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2083                 panic("assumption failed in icmp6_reflect");
2084 #endif
2085         if (off > sizeof(struct ip6_hdr)) {
2086                 size_t l;
2087                 struct ip6_hdr nip6;
2088
2089                 l = off - sizeof(struct ip6_hdr);
2090                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2091                 m_adj(m, l);
2092                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2093                 if (m->m_len < l) {
2094                         if ((m = m_pullup(m, l)) == NULL)
2095                                 return;
2096                 }
2097                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2098         } else /* off == sizeof(struct ip6_hdr) */ {
2099                 size_t l;
2100                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2101                 if (m->m_len < l) {
2102                         if ((m = m_pullup(m, l)) == NULL)
2103                                 return;
2104                 }
2105         }
2106         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2107         ip6 = mtod(m, struct ip6_hdr *);
2108         ip6->ip6_nxt = IPPROTO_ICMPV6;
2109         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2110         type = icmp6->icmp6_type; /* keep type for statistics */
2111         code = icmp6->icmp6_code; /* ditto. */
2112         hlim = 0;
2113         srcp = NULL;
2114
2115         /*
2116          * If the incoming packet was addressed directly to us (i.e. unicast),
2117          * use dst as the src for the reply.
2118          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2119          * (for example) when we encounter an error while forwarding procedure
2120          * destined to a duplicated address of ours.
2121          */
2122         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2123                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2124                 if (ia != NULL && !(ia->ia6_flags &
2125                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2126                         src6 = ia->ia_addr.sin6_addr;
2127                         srcp = &src6;
2128
2129                         if (m->m_pkthdr.rcvif != NULL) {
2130                                 /* XXX: This may not be the outgoing interface */
2131                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2132                         } else
2133                                 hlim = V_ip6_defhlim;
2134                 }
2135                 if (ia != NULL)
2136                         ifa_free(&ia->ia_ifa);
2137         }
2138
2139         if (srcp == NULL) {
2140                 int error;
2141                 struct in6_addr dst6;
2142                 uint32_t scopeid;
2143
2144                 /*
2145                  * This case matches to multicasts, our anycast, or unicasts
2146                  * that we do not own.  Select a source address based on the
2147                  * source address of the erroneous packet.
2148                  */
2149                 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2150                 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2151                     scopeid, NULL, &src6, &hlim);
2152
2153                 if (error) {
2154                         char ip6buf[INET6_ADDRSTRLEN];
2155                         nd6log((LOG_DEBUG,
2156                             "icmp6_reflect: source can't be determined: "
2157                             "dst=%s, error=%d\n",
2158                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2159                         goto bad;
2160                 }
2161                 srcp = &src6;
2162         }
2163         /*
2164          * ip6_input() drops a packet if its src is multicast.
2165          * So, the src is never multicast.
2166          */
2167         ip6->ip6_dst = ip6->ip6_src;
2168         ip6->ip6_src = *srcp;
2169         ip6->ip6_flow = 0;
2170         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2171         ip6->ip6_vfc |= IPV6_VERSION;
2172         ip6->ip6_nxt = IPPROTO_ICMPV6;
2173         ip6->ip6_hlim = hlim;
2174
2175         icmp6->icmp6_cksum = 0;
2176         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2177             sizeof(struct ip6_hdr), plen);
2178
2179         /*
2180          * XXX option handling
2181          */
2182
2183         m->m_flags &= ~(M_BCAST|M_MCAST);
2184
2185         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2186         if (outif)
2187                 icmp6_ifoutstat_inc(outif, type, code);
2188
2189         return;
2190
2191  bad:
2192         m_freem(m);
2193         return;
2194 }
2195
2196 void
2197 icmp6_fasttimo(void)
2198 {
2199
2200         mld_fasttimo();
2201 }
2202
2203 void
2204 icmp6_slowtimo(void)
2205 {
2206
2207         mld_slowtimo();
2208 }
2209
2210 static const char *
2211 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2212     struct in6_addr *tgt6)
2213 {
2214         static char buf[1024];
2215         char ip6bufs[INET6_ADDRSTRLEN];
2216         char ip6bufd[INET6_ADDRSTRLEN];
2217         char ip6buft[INET6_ADDRSTRLEN];
2218         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2219             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2220             ip6_sprintf(ip6buft, tgt6));
2221         return buf;
2222 }
2223
2224 void
2225 icmp6_redirect_input(struct mbuf *m, int off)
2226 {
2227         struct ifnet *ifp;
2228         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2229         struct nd_redirect *nd_rd;
2230         int icmp6len = ntohs(ip6->ip6_plen);
2231         char *lladdr = NULL;
2232         int lladdrlen = 0;
2233         int is_router;
2234         int is_onlink;
2235         struct in6_addr src6 = ip6->ip6_src;
2236         struct in6_addr redtgt6;
2237         struct in6_addr reddst6;
2238         union nd_opts ndopts;
2239         char ip6buf[INET6_ADDRSTRLEN];
2240
2241         M_ASSERTPKTHDR(m);
2242         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2243
2244         ifp = m->m_pkthdr.rcvif;
2245
2246         /* XXX if we are router, we don't update route by icmp6 redirect */
2247         if (V_ip6_forwarding)
2248                 goto freeit;
2249         if (!V_icmp6_rediraccept)
2250                 goto freeit;
2251
2252         /* RFC 6980: Nodes MUST silently ignore fragments */
2253         if(m->m_flags & M_FRAGMENTED)
2254                 goto freeit;
2255
2256 #ifndef PULLDOWN_TEST
2257         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2258         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2259 #else
2260         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2261         if (nd_rd == NULL) {
2262                 ICMP6STAT_INC(icp6s_tooshort);
2263                 return;
2264         }
2265 #endif
2266         redtgt6 = nd_rd->nd_rd_target;
2267         reddst6 = nd_rd->nd_rd_dst;
2268
2269         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2270             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2271                 goto freeit;
2272         }
2273
2274         /* validation */
2275         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2276                 nd6log((LOG_ERR,
2277                     "ICMP6 redirect sent from %s rejected; "
2278                     "must be from linklocal\n",
2279                     ip6_sprintf(ip6buf, &src6)));
2280                 goto bad;
2281         }
2282         if (ip6->ip6_hlim != 255) {
2283                 nd6log((LOG_ERR,
2284                     "ICMP6 redirect sent from %s rejected; "
2285                     "hlim=%d (must be 255)\n",
2286                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2287                 goto bad;
2288         }
2289     {
2290         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2291         struct nhop6_basic nh6;
2292         struct in6_addr kdst;
2293         uint32_t scopeid;
2294
2295         in6_splitscope(&reddst6, &kdst, &scopeid);
2296         if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){
2297                 if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
2298                         nd6log((LOG_ERR,
2299                             "ICMP6 redirect rejected; no route "
2300                             "with inet6 gateway found for redirect dst: %s\n",
2301                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2302                         goto bad;
2303                 }
2304
2305                 /*
2306                  * Embed scope zone id into next hop address, since
2307                  * fib6_lookup_nh_basic() returns address without embedded
2308                  * scope zone id.
2309                  */
2310                 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL))
2311                         goto freeit;
2312
2313                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
2314                         nd6log((LOG_ERR,
2315                             "ICMP6 redirect rejected; "
2316                             "not equal to gw-for-src=%s (must be same): "
2317                             "%s\n",
2318                             ip6_sprintf(ip6buf, &nh6.nh_addr),
2319                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2320                         goto bad;
2321                 }
2322         } else {
2323                 nd6log((LOG_ERR,
2324                     "ICMP6 redirect rejected; "
2325                     "no route found for redirect dst: %s\n",
2326                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2327                 goto bad;
2328         }
2329     }
2330         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2331                 nd6log((LOG_ERR,
2332                     "ICMP6 redirect rejected; "
2333                     "redirect dst must be unicast: %s\n",
2334                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2335                 goto bad;
2336         }
2337
2338         is_router = is_onlink = 0;
2339         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2340                 is_router = 1;  /* router case */
2341         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2342                 is_onlink = 1;  /* on-link destination case */
2343         if (!is_router && !is_onlink) {
2344                 nd6log((LOG_ERR,
2345                     "ICMP6 redirect rejected; "
2346                     "neither router case nor onlink case: %s\n",
2347                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2348                 goto bad;
2349         }
2350
2351         icmp6len -= sizeof(*nd_rd);
2352         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2353         if (nd6_options(&ndopts) < 0) {
2354                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2355                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2356                 /* nd6_options have incremented stats */
2357                 goto freeit;
2358         }
2359
2360         if (ndopts.nd_opts_tgt_lladdr) {
2361                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2362                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2363         }
2364
2365         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2366                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2367                     "(if %d, icmp6 packet %d): %s\n",
2368                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2369                     ifp->if_addrlen, lladdrlen - 2,
2370                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2371                 goto bad;
2372         }
2373
2374         /* Validation passed. */
2375
2376         /* RFC 2461 8.3 */
2377         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2378             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2379
2380         /*
2381          * Install a gateway route in the better-router case or an interface
2382          * route in the on-link-destination case.
2383          */
2384         {
2385                 struct sockaddr_in6 sdst;
2386                 struct sockaddr_in6 sgw;
2387                 struct sockaddr_in6 ssrc;
2388                 struct sockaddr *gw;
2389                 int rt_flags;
2390                 u_int fibnum;
2391
2392                 bzero(&sdst, sizeof(sdst));
2393                 bzero(&ssrc, sizeof(ssrc));
2394                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2395                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2396                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2397                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2398                 rt_flags = RTF_HOST;
2399                 if (is_router) {
2400                         bzero(&sgw, sizeof(sgw));
2401                         sgw.sin6_family = AF_INET6;
2402                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2403                         bcopy(&redtgt6, &sgw.sin6_addr,
2404                                 sizeof(struct in6_addr));
2405                         gw = (struct sockaddr *)&sgw;
2406                         rt_flags |= RTF_GATEWAY;
2407                 } else
2408                         gw = ifp->if_addr->ifa_addr;
2409                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2410                         in6_rtredirect((struct sockaddr *)&sdst, gw,
2411                             (struct sockaddr *)NULL, rt_flags,
2412                             (struct sockaddr *)&ssrc, fibnum);
2413         }
2414         /* finally update cached route in each socket via pfctlinput */
2415     {
2416         struct sockaddr_in6 sdst;
2417
2418         bzero(&sdst, sizeof(sdst));
2419         sdst.sin6_family = AF_INET6;
2420         sdst.sin6_len = sizeof(struct sockaddr_in6);
2421         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2422         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2423     }
2424
2425  freeit:
2426         m_freem(m);
2427         return;
2428
2429  bad:
2430         ICMP6STAT_INC(icp6s_badredirect);
2431         m_freem(m);
2432 }
2433
2434 void
2435 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2436 {
2437         struct ifnet *ifp;      /* my outgoing interface */
2438         struct in6_addr *ifp_ll6;
2439         struct in6_addr *router_ll6;
2440         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2441         struct mbuf *m = NULL;  /* newly allocated one */
2442         struct m_tag *mtag;
2443         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2444         struct nd_redirect *nd_rd;
2445         struct llentry *ln = NULL;
2446         size_t maxlen;
2447         u_char *p;
2448         struct ifnet *outif = NULL;
2449         struct sockaddr_in6 src_sa;
2450
2451         icmp6_errcount(ND_REDIRECT, 0);
2452
2453         /* if we are not router, we don't send icmp6 redirect */
2454         if (!V_ip6_forwarding)
2455                 goto fail;
2456
2457         /* sanity check */
2458         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2459                 goto fail;
2460
2461         /*
2462          * Address check:
2463          *  the source address must identify a neighbor, and
2464          *  the destination address must not be a multicast address
2465          *  [RFC 2461, sec 8.2]
2466          */
2467         sip6 = mtod(m0, struct ip6_hdr *);
2468         bzero(&src_sa, sizeof(src_sa));
2469         src_sa.sin6_family = AF_INET6;
2470         src_sa.sin6_len = sizeof(src_sa);
2471         src_sa.sin6_addr = sip6->ip6_src;
2472         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2473                 goto fail;
2474         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2475                 goto fail;      /* what should we do here? */
2476
2477         /* rate limit */
2478         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2479                 goto fail;
2480
2481         /*
2482          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2483          * we almost always ask for an mbuf cluster for simplicity.
2484          * (MHLEN < IPV6_MMTU is almost always true)
2485          */
2486 #if IPV6_MMTU >= MCLBYTES
2487 # error assumption failed about IPV6_MMTU and MCLBYTES
2488 #endif
2489         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2490         if (m == NULL)
2491                 goto fail;
2492         M_SETFIB(m, rt->rt_fibnum);
2493         maxlen = M_TRAILINGSPACE(m);
2494         maxlen = min(IPV6_MMTU, maxlen);
2495         /* just for safety */
2496         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2497             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2498                 goto fail;
2499         }
2500
2501         {
2502                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2503                 struct in6_ifaddr *ia;
2504                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2505                                                  IN6_IFF_NOTREADY|
2506                                                  IN6_IFF_ANYCAST)) == NULL)
2507                         goto fail;
2508                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2509                 /* XXXRW: reference released prematurely. */
2510                 ifa_free(&ia->ia_ifa);
2511         }
2512
2513         /* get ip6 linklocal address for the router. */
2514         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2515                 struct sockaddr_in6 *sin6;
2516                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2517                 router_ll6 = &sin6->sin6_addr;
2518                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2519                         router_ll6 = (struct in6_addr *)NULL;
2520         } else
2521                 router_ll6 = (struct in6_addr *)NULL;
2522
2523         /* ip6 */
2524         ip6 = mtod(m, struct ip6_hdr *);
2525         ip6->ip6_flow = 0;
2526         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2527         ip6->ip6_vfc |= IPV6_VERSION;
2528         /* ip6->ip6_plen will be set later */
2529         ip6->ip6_nxt = IPPROTO_ICMPV6;
2530         ip6->ip6_hlim = 255;
2531         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2532         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2533         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2534
2535         /* ND Redirect */
2536         nd_rd = (struct nd_redirect *)(ip6 + 1);
2537         nd_rd->nd_rd_type = ND_REDIRECT;
2538         nd_rd->nd_rd_code = 0;
2539         nd_rd->nd_rd_reserved = 0;
2540         if (rt->rt_flags & RTF_GATEWAY) {
2541                 /*
2542                  * nd_rd->nd_rd_target must be a link-local address in
2543                  * better router cases.
2544                  */
2545                 if (!router_ll6)
2546                         goto fail;
2547                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2548                     sizeof(nd_rd->nd_rd_target));
2549                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2550                     sizeof(nd_rd->nd_rd_dst));
2551         } else {
2552                 /* make sure redtgt == reddst */
2553                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2554                     sizeof(nd_rd->nd_rd_target));
2555                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2556                     sizeof(nd_rd->nd_rd_dst));
2557         }
2558
2559         p = (u_char *)(nd_rd + 1);
2560
2561         if (!router_ll6)
2562                 goto nolladdropt;
2563
2564         {
2565                 /* target lladdr option */
2566                 int len;
2567                 struct nd_opt_hdr *nd_opt;
2568                 char *lladdr;
2569
2570                 IF_AFDATA_RLOCK(ifp);
2571                 ln = nd6_lookup(router_ll6, 0, ifp);
2572                 IF_AFDATA_RUNLOCK(ifp);
2573                 if (ln == NULL)
2574                         goto nolladdropt;
2575
2576                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2577                 len = (len + 7) & ~7;   /* round by 8 */
2578                 /* safety check */
2579                 if (len + (p - (u_char *)ip6) > maxlen)
2580                         goto nolladdropt;
2581
2582                 if (ln->la_flags & LLE_VALID) {
2583                         nd_opt = (struct nd_opt_hdr *)p;
2584                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2585                         nd_opt->nd_opt_len = len >> 3;
2586                         lladdr = (char *)(nd_opt + 1);
2587                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2588                         p += len;
2589                 }
2590         }
2591 nolladdropt:
2592         if (ln != NULL)
2593                 LLE_RUNLOCK(ln);
2594
2595         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2596
2597         /* just to be safe */
2598 #ifdef M_DECRYPTED      /*not openbsd*/
2599         if (m0->m_flags & M_DECRYPTED)
2600                 goto noredhdropt;
2601 #endif
2602         if (p - (u_char *)ip6 > maxlen)
2603                 goto noredhdropt;
2604
2605         {
2606                 /* redirected header option */
2607                 int len;
2608                 struct nd_opt_rd_hdr *nd_opt_rh;
2609
2610                 /*
2611                  * compute the maximum size for icmp6 redirect header option.
2612                  * XXX room for auth header?
2613                  */
2614                 len = maxlen - (p - (u_char *)ip6);
2615                 len &= ~7;
2616
2617                 /* This is just for simplicity. */
2618                 if (m0->m_pkthdr.len != m0->m_len) {
2619                         if (m0->m_next) {
2620                                 m_freem(m0->m_next);
2621                                 m0->m_next = NULL;
2622                         }
2623                         m0->m_pkthdr.len = m0->m_len;
2624                 }
2625
2626                 /*
2627                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2628                  * about padding/truncate rule for the original IP packet.
2629                  * From the discussion on IPv6imp in Feb 1999,
2630                  * the consensus was:
2631                  * - "attach as much as possible" is the goal
2632                  * - pad if not aligned (original size can be guessed by
2633                  *   original ip6 header)
2634                  * Following code adds the padding if it is simple enough,
2635                  * and truncates if not.
2636                  */
2637                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2638                         panic("assumption failed in %s:%d", __FILE__,
2639                             __LINE__);
2640
2641                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2642                         /* not enough room, truncate */
2643                         m0->m_pkthdr.len = m0->m_len = len -
2644                             sizeof(*nd_opt_rh);
2645                 } else {
2646                         /* enough room, pad or truncate */
2647                         size_t extra;
2648
2649                         extra = m0->m_pkthdr.len % 8;
2650                         if (extra) {
2651                                 /* pad if easy enough, truncate if not */
2652                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2653                                         /* pad */
2654                                         m0->m_len += (8 - extra);
2655                                         m0->m_pkthdr.len += (8 - extra);
2656                                 } else {
2657                                         /* truncate */
2658                                         m0->m_pkthdr.len -= extra;
2659                                         m0->m_len -= extra;
2660                                 }
2661                         }
2662                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2663                         m0->m_pkthdr.len = m0->m_len = len -
2664                             sizeof(*nd_opt_rh);
2665                 }
2666
2667                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2668                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2669                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2670                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2671                 p += sizeof(*nd_opt_rh);
2672                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2673
2674                 /* connect m0 to m */
2675                 m_tag_delete_chain(m0, NULL);
2676                 m0->m_flags &= ~M_PKTHDR;
2677                 m->m_next = m0;
2678                 m->m_pkthdr.len = m->m_len + m0->m_len;
2679                 m0 = NULL;
2680         }
2681 noredhdropt:;
2682         if (m0) {
2683                 m_freem(m0);
2684                 m0 = NULL;
2685         }
2686
2687         /* XXX: clear embedded link IDs in the inner header */
2688         in6_clearscope(&sip6->ip6_src);
2689         in6_clearscope(&sip6->ip6_dst);
2690         in6_clearscope(&nd_rd->nd_rd_target);
2691         in6_clearscope(&nd_rd->nd_rd_dst);
2692
2693         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2694
2695         nd_rd->nd_rd_cksum = 0;
2696         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2697             sizeof(*ip6), ntohs(ip6->ip6_plen));
2698
2699         if (send_sendso_input_hook != NULL) {
2700                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2701                         M_NOWAIT);
2702                 if (mtag == NULL)
2703                         goto fail;
2704                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2705                 m_tag_prepend(m, mtag);
2706         }
2707
2708         /* send the packet to outside... */
2709         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2710         if (outif) {
2711                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2712                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2713         }
2714         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2715
2716         return;
2717
2718 fail:
2719         if (m)
2720                 m_freem(m);
2721         if (m0)
2722                 m_freem(m0);
2723 }
2724
2725 /*
2726  * ICMPv6 socket option processing.
2727  */
2728 int
2729 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2730 {
2731         int error = 0;
2732         int optlen;
2733         struct inpcb *inp = sotoinpcb(so);
2734         int level, op, optname;
2735
2736         if (sopt) {
2737                 level = sopt->sopt_level;
2738                 op = sopt->sopt_dir;
2739                 optname = sopt->sopt_name;
2740                 optlen = sopt->sopt_valsize;
2741         } else
2742                 level = op = optname = optlen = 0;
2743
2744         if (level != IPPROTO_ICMPV6) {
2745                 return EINVAL;
2746         }
2747
2748         switch (op) {
2749         case PRCO_SETOPT:
2750                 switch (optname) {
2751                 case ICMP6_FILTER:
2752                     {
2753                         struct icmp6_filter ic6f;
2754
2755                         if (optlen != sizeof(ic6f)) {
2756                                 error = EMSGSIZE;
2757                                 break;
2758                         }
2759                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2760                         if (error == 0) {
2761                                 INP_WLOCK(inp);
2762                                 *inp->in6p_icmp6filt = ic6f;
2763                                 INP_WUNLOCK(inp);
2764                         }
2765                         break;
2766                     }
2767
2768                 default:
2769                         error = ENOPROTOOPT;
2770                         break;
2771                 }
2772                 break;
2773
2774         case PRCO_GETOPT:
2775                 switch (optname) {
2776                 case ICMP6_FILTER:
2777                     {
2778                         struct icmp6_filter ic6f;
2779
2780                         INP_RLOCK(inp);
2781                         ic6f = *inp->in6p_icmp6filt;
2782                         INP_RUNLOCK(inp);
2783                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2784                         break;
2785                     }
2786
2787                 default:
2788                         error = ENOPROTOOPT;
2789                         break;
2790                 }
2791                 break;
2792         }
2793
2794         return (error);
2795 }
2796
2797 /*
2798  * Perform rate limit check.
2799  * Returns 0 if it is okay to send the icmp6 packet.
2800  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2801  * limitation.
2802  *
2803  * XXX per-destination/type check necessary?
2804  *
2805  * dst - not used at this moment
2806  * type - not used at this moment
2807  * code - not used at this moment
2808  */
2809 static int
2810 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2811     const int code)
2812 {
2813         int ret;
2814
2815         ret = 0;        /* okay to send */
2816
2817         /* PPS limit */
2818         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2819             V_icmp6errppslim)) {
2820                 /* The packet is subject to rate limit */
2821                 ret++;
2822         }
2823
2824         return ret;
2825 }