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                         code = PRC_UNREACH_NET;
 489                         break;
 490                 case ICMP6_DST_UNREACH_ADMIN:
 491                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 492                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 493                         break;
 494                 case ICMP6_DST_UNREACH_ADDR:
 495                         code = PRC_HOSTDEAD;
 496                         break;
 497                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 498                         /* I mean "source address was incorrect." */
 499                         code = PRC_PARAMPROB;
 500                         break;
 501                 case ICMP6_DST_UNREACH_NOPORT:
 502                         code = PRC_UNREACH_PORT;
 503                         break;
 504                 default:
 505                         goto badcode;
 506                 }
 507                 goto deliver;
 508                 break;
 509
 510         case ICMP6_PACKET_TOO_BIG:
 511                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 512
 513                 /* validation is made in icmp6_mtudisc_update */
 514
 515                 code = PRC_MSGSIZE;
 516
 517                 /*
 518                  * Updating the path MTU will be done after examining
 519                  * intermediate extension headers.
 520                  */
 521                 goto deliver;
 522                 break;
 523
 524         case ICMP6_TIME_EXCEEDED:
 525                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 526                 switch (code) {
 527                 case ICMP6_TIME_EXCEED_TRANSIT:
 528                         code = PRC_TIMXCEED_INTRANS;
 529                         break;
 530                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 531                         code = PRC_TIMXCEED_REASS;
 532                         break;
 533                 default:
 534                         goto badcode;
 535                 }
 536                 goto deliver;
 537                 break;
 538
 539         case ICMP6_PARAM_PROB:
 540                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 541                 switch (code) {
 542                 case ICMP6_PARAMPROB_NEXTHEADER:
 543                         code = PRC_UNREACH_PROTOCOL;
 544                         break;
 545                 case ICMP6_PARAMPROB_HEADER:
 546                 case ICMP6_PARAMPROB_OPTION:
 547                         code = PRC_PARAMPROB;
 548                         break;
 549                 default:
 550                         goto badcode;
 551                 }
 552                 goto deliver;
 553                 break;
 554
 555         case ICMP6_ECHO_REQUEST:
 556                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 557                 if (code != 0)
 558                         goto badcode;
 559                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 560                         /* Give up remote */
 561                         break;
 562                 }
 563                 if (!M_WRITABLE(n)
 564                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 565                         struct mbuf *n0 = n;
 566                         int n0len;
 567
 568                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 569                         n = m_gethdr(M_NOWAIT, n0->m_type);
 570                         if (n == NULL) {
 571                                 /* Give up remote */
 572                                 m_freem(n0);
 573                                 break;
 574                         }
 575
 576                         m_move_pkthdr(n, n0);   /* FIB copied. */
 577                         n0len = n0->m_pkthdr.len;       /* save for use below */
 578                         /*
 579                          * Copy IPv6 and ICMPv6 only.
 580                          */
 581                         nip6 = mtod(n, struct ip6_hdr *);
 582                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 583                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 584                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 585                         noff = sizeof(struct ip6_hdr);
 586                         /* new mbuf contains only ipv6+icmpv6 headers */
 587                         n->m_len = noff + sizeof(struct icmp6_hdr);
 588                         /*
 589                          * Adjust mbuf.  ip6_plen will be adjusted in
 590                          * ip6_output().
 591                          */
 592                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 593                         /* recalculate complete packet size */
 594                         n->m_pkthdr.len = n0len + (noff - off);
 595                         n->m_next = n0;
 596                 } else {
 597                         nip6 = mtod(n, struct ip6_hdr *);
 598                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 599                             sizeof(*nicmp6));
 600                         noff = off;
 601                 }
 602                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 603                 nicmp6->icmp6_code = 0;
 604                 if (n) {
 605                         ICMP6STAT_INC(icp6s_reflect);
 606                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 607                         icmp6_reflect(n, noff);
 608                 }
 609                 break;
 610
 611         case ICMP6_ECHO_REPLY:
 612                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 613                 if (code != 0)
 614                         goto badcode;
 615                 break;
 616
 617         case MLD_LISTENER_QUERY:
 618         case MLD_LISTENER_REPORT:
 619         case MLD_LISTENER_DONE:
 620         case MLDV2_LISTENER_REPORT:
 621                 /*
 622                  * Drop MLD traffic which is not link-local, has a hop limit
 623                  * of greater than 1 hop, or which does not have the
 624                  * IPv6 HBH Router Alert option.
 625                  * As IPv6 HBH options are stripped in ip6_input() we must
 626                  * check an mbuf header flag.
 627                  * XXX Should we also sanity check that these messages
 628                  * were directed to a link-local multicast prefix?
 629                  */
 630                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 631                         goto freeit;
 632                 if (mld_input(m, off, icmp6len) != 0)
 633                         return (IPPROTO_DONE);
 634                 /* m stays. */
 635                 break;
 636
 637         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 638             {
 639                 enum { WRU, FQDN } mode;
 640
 641                 if (!V_icmp6_nodeinfo)
 642                         break;
 643
 644                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 645                         mode = WRU;
 646                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 647                         mode = FQDN;
 648                 else
 649                         goto badlen;
 650
 651                 if (mode == FQDN) {
 652 #ifndef PULLDOWN_TEST
 653                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 654                             IPPROTO_DONE);
 655 #endif
 656                         n = m_copy(m, 0, M_COPYALL);
 657                         if (n)
 658                                 n = ni6_input(n, off);
 659                         /* XXX meaningless if n == NULL */
 660                         noff = sizeof(struct ip6_hdr);
 661                 } else {
 662                         struct prison *pr;
 663                         u_char *p;
 664                         int maxhlen, hlen;
 665
 666                         /*
 667                          * XXX: this combination of flags is pointless,
 668                          * but should we keep this for compatibility?
 669                          */
 670                         if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
 671                             ICMP6_NODEINFO_TMPADDROK)) !=
 672                             (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
 673                                 break;
 674
 675                         if (code != 0)
 676                                 goto badcode;
 677
 678                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 679                         n = m_gethdr(M_NOWAIT, m->m_type);
 680                         if (n == NULL) {
 681                                 /* Give up remote */
 682                                 break;
 683                         }
 684                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 685                                 /*
 686                                  * Previous code did a blind M_COPY_PKTHDR
 687                                  * and said "just for rcvif".  If true, then
 688                                  * we could tolerate the dup failing (due to
 689                                  * the deep copy of the tag chain).  For now
 690                                  * be conservative and just fail.
 691                                  */
 692                                 m_free(n);
 693                                 n = NULL;
 694                         }
 695                         maxhlen = M_TRAILINGSPACE(n) -
 696                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 697                         pr = curthread->td_ucred->cr_prison;
 698                         mtx_lock(&pr->pr_mtx);
 699                         hlen = strlen(pr->pr_hostname);
 700                         if (maxhlen > hlen)
 701                                 maxhlen = hlen;
 702                         /*
 703                          * Copy IPv6 and ICMPv6 only.
 704                          */
 705                         nip6 = mtod(n, struct ip6_hdr *);
 706                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 707                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 708                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 709                         p = (u_char *)(nicmp6 + 1);
 710                         bzero(p, 4);
 711                         /* meaningless TTL */
 712                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 713                         mtx_unlock(&pr->pr_mtx);
 714                         noff = sizeof(struct ip6_hdr);
 715                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 716                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 717                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 718                         nicmp6->icmp6_code = 0;
 719                 }
 720                 if (n) {
 721                         ICMP6STAT_INC(icp6s_reflect);
 722                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 723                         icmp6_reflect(n, noff);
 724                 }
 725                 break;
 726             }
 727
 728         case ICMP6_WRUREPLY:
 729                 if (code != 0)
 730                         goto badcode;
 731                 break;
 732
 733         case ND_ROUTER_SOLICIT:
 734                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 735                 if (code != 0)
 736                         goto badcode;
 737                 if (icmp6len < sizeof(struct nd_router_solicit))
 738                         goto badlen;
 739                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 740                         /* give up local */
 741
 742                         /* Send incoming SeND packet to user space. */
 743                         if (send_sendso_input_hook != NULL) {
 744                                 IP6_EXTHDR_CHECK(m, off,
 745                                     icmp6len, IPPROTO_DONE);
 746                                 error = send_sendso_input_hook(m, ifp,
 747                                     SND_IN, ip6len);
 748                                 /* -1 == no app on SEND socket */
 749                                 if (error == 0)
 750                                         return (IPPROTO_DONE);
 751                                 nd6_rs_input(m, off, icmp6len);
 752                         } else
 753                                 nd6_rs_input(m, off, icmp6len);
 754                         m = NULL;
 755                         goto freeit;
 756                 }
 757                 if (send_sendso_input_hook != NULL) {
 758                         IP6_EXTHDR_CHECK(n, off,
 759                             icmp6len, IPPROTO_DONE);
 760                         error = send_sendso_input_hook(n, ifp,
 761                             SND_IN, ip6len);
 762                         if (error == 0)
 763                                 goto freeit;
 764                         /* -1 == no app on SEND socket */
 765                         nd6_rs_input(n, off, icmp6len);
 766                 } else
 767                         nd6_rs_input(n, off, icmp6len);
 768                 /* m stays. */
 769                 break;
 770
 771         case ND_ROUTER_ADVERT:
 772                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 773                 if (code != 0)
 774                         goto badcode;
 775                 if (icmp6len < sizeof(struct nd_router_advert))
 776                         goto badlen;
 777                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 778
 779                         /* Send incoming SeND-protected/ND packet to user space. */
 780                         if (send_sendso_input_hook != NULL) {
 781                                 error = send_sendso_input_hook(m, ifp,
 782                                     SND_IN, ip6len);
 783                                 if (error == 0)
 784                                         return (IPPROTO_DONE);
 785                                 nd6_ra_input(m, off, icmp6len);
 786                         } else
 787                                 nd6_ra_input(m, off, icmp6len);
 788                         m = NULL;
 789                         goto freeit;
 790                 }
 791                 if (send_sendso_input_hook != NULL) {
 792                         error = send_sendso_input_hook(n, ifp,
 793                             SND_IN, ip6len);
 794                         if (error == 0)
 795                                 goto freeit;
 796                         nd6_ra_input(n, off, icmp6len);
 797                 } else
 798                         nd6_ra_input(n, off, icmp6len);
 799                 /* m stays. */
 800                 break;
 801
 802         case ND_NEIGHBOR_SOLICIT:
 803                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 804                 if (code != 0)
 805                         goto badcode;
 806                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 807                         goto badlen;
 808                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 809                         if (send_sendso_input_hook != NULL) {
 810                                 error = send_sendso_input_hook(m, ifp,
 811                                     SND_IN, ip6len);
 812                                 if (error == 0)
 813                                         return (IPPROTO_DONE);
 814                                 nd6_ns_input(m, off, icmp6len);
 815                         } else
 816                                 nd6_ns_input(m, off, icmp6len);
 817                         m = NULL;
 818                         goto freeit;
 819                 }
 820                 if (send_sendso_input_hook != NULL) {
 821                         error = send_sendso_input_hook(n, ifp,
 822                             SND_IN, ip6len);
 823                         if (error == 0)
 824                                 goto freeit;
 825                         nd6_ns_input(n, off, icmp6len);
 826                 } else
 827                         nd6_ns_input(n, off, icmp6len);
 828                 /* m stays. */
 829                 break;
 830
 831         case ND_NEIGHBOR_ADVERT:
 832                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 833                 if (code != 0)
 834                         goto badcode;
 835                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 836                         goto badlen;
 837                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 838
 839                         /* Send incoming SeND-protected/ND packet to user space. */
 840                         if (send_sendso_input_hook != NULL) {
 841                                 error = send_sendso_input_hook(m, ifp,
 842                                     SND_IN, ip6len);
 843                                 if (error == 0)
 844                                         return (IPPROTO_DONE);
 845                                 nd6_na_input(m, off, icmp6len);
 846                         } else
 847                                 nd6_na_input(m, off, icmp6len);
 848                         m = NULL;
 849                         goto freeit;
 850                 }
 851                 if (send_sendso_input_hook != NULL) {
 852                         error = send_sendso_input_hook(n, ifp,
 853                             SND_IN, ip6len);
 854                         if (error == 0)
 855                                 goto freeit;
 856                         nd6_na_input(n, off, icmp6len);
 857                 } else
 858                         nd6_na_input(n, off, icmp6len);
 859                 /* m stays. */
 860                 break;
 861
 862         case ND_REDIRECT:
 863                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 864                 if (code != 0)
 865                         goto badcode;
 866                 if (icmp6len < sizeof(struct nd_redirect))
 867                         goto badlen;
 868                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 869                         if (send_sendso_input_hook != NULL) {
 870                                 error = send_sendso_input_hook(m, ifp,
 871                                     SND_IN, ip6len);
 872                                 if (error == 0)
 873                                         return (IPPROTO_DONE);
 874                             icmp6_redirect_input(m, off);
 875                         } else
 876                                 icmp6_redirect_input(m, off);
 877                         m = NULL;
 878                         goto freeit;
 879                 }
 880                 if (send_sendso_input_hook != NULL) {
 881                         error = send_sendso_input_hook(n, ifp,
 882                             SND_IN, ip6len);
 883                         if (error == 0)
 884                                 goto freeit;
 885                         icmp6_redirect_input(n, off);
 886                 } else
 887                         icmp6_redirect_input(n, off);
 888                 /* m stays. */
 889                 break;
 890
 891         case ICMP6_ROUTER_RENUMBERING:
 892                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 893                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 894                         goto badcode;
 895                 if (icmp6len < sizeof(struct icmp6_router_renum))
 896                         goto badlen;
 897                 break;
 898
 899         default:
 900                 nd6log((LOG_DEBUG,
 901                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 902                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 903                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 904                     ifp ? ifp->if_index : 0));
 905                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 906                         /* ICMPv6 error: MUST deliver it by spec... */
 907                         code = PRC_NCMDS;
 908                         /* deliver */
 909                 } else {
 910                         /* ICMPv6 informational: MUST not deliver */
 911                         break;
 912                 }
 913         deliver:
 914                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 915                         /* In this case, m should've been freed. */
 916                         return (IPPROTO_DONE);
 917                 }
 918                 break;
 919
 920         badcode:
 921                 ICMP6STAT_INC(icp6s_badcode);
 922                 break;
 923
 924         badlen:
 925                 ICMP6STAT_INC(icp6s_badlen);
 926                 break;
 927         }
 928
 929         /* deliver the packet to appropriate sockets */
 930         icmp6_rip6_input(&m, *offp);
 931
 932         return IPPROTO_DONE;
 933
 934  freeit:
 935         m_freem(m);
 936         return IPPROTO_DONE;
 937 }
 938
 939 static int
 940 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 941 {
 942         struct mbuf *m = *mp;
 943         struct icmp6_hdr *icmp6;
 944         struct ip6_hdr *eip6;
 945         u_int32_t notifymtu;
 946         struct sockaddr_in6 icmp6src, icmp6dst;
 947
 948         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 949                 ICMP6STAT_INC(icp6s_tooshort);
 950                 goto freeit;
 951         }
 952 #ifndef PULLDOWN_TEST
 953         IP6_EXTHDR_CHECK(m, off,
 954             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 955         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 956 #else
 957         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 958             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 959         if (icmp6 == NULL) {
 960                 ICMP6STAT_INC(icp6s_tooshort);
 961                 return (-1);
 962         }
 963 #endif
 964         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 965
 966         /* Detect the upper level protocol */
 967         {
 968                 void (*ctlfunc)(int, struct sockaddr *, void *);
 969                 u_int8_t nxt = eip6->ip6_nxt;
 970                 int eoff = off + sizeof(struct icmp6_hdr) +
 971                     sizeof(struct ip6_hdr);
 972                 struct ip6ctlparam ip6cp;
 973                 struct in6_addr *finaldst = NULL;
 974                 int icmp6type = icmp6->icmp6_type;
 975                 struct ip6_frag *fh;
 976                 struct ip6_rthdr *rth;
 977                 struct ip6_rthdr0 *rth0;
 978                 int rthlen;
 979
 980                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 981                         struct ip6_ext *eh;
 982
 983                         switch (nxt) {
 984                         case IPPROTO_HOPOPTS:
 985                         case IPPROTO_DSTOPTS:
 986                         case IPPROTO_AH:
 987 #ifndef PULLDOWN_TEST
 988                                 IP6_EXTHDR_CHECK(m, 0,
 989                                     eoff + sizeof(struct ip6_ext), -1);
 990                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 991 #else
 992                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 993                                     eoff, sizeof(*eh));
 994                                 if (eh == NULL) {
 995                                         ICMP6STAT_INC(icp6s_tooshort);
 996                                         return (-1);
 997                                 }
 998 #endif
 999
1000                                 if (nxt == IPPROTO_AH)
1001                                         eoff += (eh->ip6e_len + 2) << 2;
1002                                 else
1003                                         eoff += (eh->ip6e_len + 1) << 3;
1004                                 nxt = eh->ip6e_nxt;
1005                                 break;
1006                         case IPPROTO_ROUTING:
1007                                 /*
1008                                  * When the erroneous packet contains a
1009                                  * routing header, we should examine the
1010                                  * header to determine the final destination.
1011                                  * Otherwise, we can't properly update
1012                                  * information that depends on the final
1013                                  * destination (e.g. path MTU).
1014                                  */
1015 #ifndef PULLDOWN_TEST
1016                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1017                                 rth = (struct ip6_rthdr *)
1018                                     (mtod(m, caddr_t) + eoff);
1019 #else
1020                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1021                                     eoff, sizeof(*rth));
1022                                 if (rth == NULL) {
1023                                         ICMP6STAT_INC(icp6s_tooshort);
1024                                         return (-1);
1025                                 }
1026 #endif
1027                                 rthlen = (rth->ip6r_len + 1) << 3;
1028                                 /*
1029                                  * XXX: currently there is no
1030                                  * officially defined type other
1031                                  * than type-0.
1032                                  * Note that if the segment left field
1033                                  * is 0, all intermediate hops must
1034                                  * have been passed.
1035                                  */
1036                                 if (rth->ip6r_segleft &&
1037                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1038                                         int hops;
1039
1040 #ifndef PULLDOWN_TEST
1041                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1042                                         rth0 = (struct ip6_rthdr0 *)
1043                                             (mtod(m, caddr_t) + eoff);
1044 #else
1045                                         IP6_EXTHDR_GET(rth0,
1046                                             struct ip6_rthdr0 *, m,
1047                                             eoff, rthlen);
1048                                         if (rth0 == NULL) {
1049                                                 ICMP6STAT_INC(icp6s_tooshort);
1050                                                 return (-1);
1051                                         }
1052 #endif
1053                                         /* just ignore a bogus header */
1054                                         if ((rth0->ip6r0_len % 2) == 0 &&
1055                                             (hops = rth0->ip6r0_len/2))
1056                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1057                                 }
1058                                 eoff += rthlen;
1059                                 nxt = rth->ip6r_nxt;
1060                                 break;
1061                         case IPPROTO_FRAGMENT:
1062 #ifndef PULLDOWN_TEST
1063                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1064                                     sizeof(struct ip6_frag), -1);
1065                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1066                                     eoff);
1067 #else
1068                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1069                                     eoff, sizeof(*fh));
1070                                 if (fh == NULL) {
1071                                         ICMP6STAT_INC(icp6s_tooshort);
1072                                         return (-1);
1073                                 }
1074 #endif
1075                                 /*
1076                                  * Data after a fragment header is meaningless
1077                                  * unless it is the first fragment, but
1078                                  * we'll go to the notify label for path MTU
1079                                  * discovery.
1080                                  */
1081                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1082                                         goto notify;
1083
1084                                 eoff += sizeof(struct ip6_frag);
1085                                 nxt = fh->ip6f_nxt;
1086                                 break;
1087                         default:
1088                                 /*
1089                                  * This case includes ESP and the No Next
1090                                  * Header.  In such cases going to the notify
1091                                  * label does not have any meaning
1092                                  * (i.e. ctlfunc will be NULL), but we go
1093                                  * anyway since we might have to update
1094                                  * path MTU information.
1095                                  */
1096                                 goto notify;
1097                         }
1098                 }
1099           notify:
1100 #ifndef PULLDOWN_TEST
1101                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1102 #else
1103                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1104                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1105                 if (icmp6 == NULL) {
1106                         ICMP6STAT_INC(icp6s_tooshort);
1107                         return (-1);
1108                 }
1109 #endif
1110
1111                 /*
1112                  * retrieve parameters from the inner IPv6 header, and convert
1113                  * them into sockaddr structures.
1114                  * XXX: there is no guarantee that the source or destination
1115                  * addresses of the inner packet are in the same scope as
1116                  * the addresses of the icmp packet.  But there is no other
1117                  * way to determine the zone.
1118                  */
1119                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1120
1121                 bzero(&icmp6dst, sizeof(icmp6dst));
1122                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1123                 icmp6dst.sin6_family = AF_INET6;
1124                 if (finaldst == NULL)
1125                         icmp6dst.sin6_addr = eip6->ip6_dst;
1126                 else
1127                         icmp6dst.sin6_addr = *finaldst;
1128                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1129                         goto freeit;
1130                 bzero(&icmp6src, sizeof(icmp6src));
1131                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1132                 icmp6src.sin6_family = AF_INET6;
1133                 icmp6src.sin6_addr = eip6->ip6_src;
1134                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1135                         goto freeit;
1136                 icmp6src.sin6_flowinfo =
1137                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1138
1139                 if (finaldst == NULL)
1140                         finaldst = &eip6->ip6_dst;
1141                 ip6cp.ip6c_m = m;
1142                 ip6cp.ip6c_icmp6 = icmp6;
1143                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1144                 ip6cp.ip6c_off = eoff;
1145                 ip6cp.ip6c_finaldst = finaldst;
1146                 ip6cp.ip6c_src = &icmp6src;
1147                 ip6cp.ip6c_nxt = nxt;
1148
1149                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1150                         notifymtu = ntohl(icmp6->icmp6_mtu);
1151                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1152                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1153                 }
1154
1155                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1156                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1157                 if (ctlfunc) {
1158                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1159                             &ip6cp);
1160                 }
1161         }
1162         *mp = m;
1163         return (0);
1164
1165   freeit:
1166         m_freem(m);
1167         return (-1);
1168 }
1169
1170 void
1171 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1172 {
1173         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1174         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1175         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1176         u_int mtu = ntohl(icmp6->icmp6_mtu);
1177         struct in_conninfo inc;
1178
1179 #if 0
1180         /*
1181          * RFC2460 section 5, last paragraph.
1182          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1183          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1184          * due to packet translator in the middle.
1185          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1186          * special handling.
1187          */
1188         if (mtu < IPV6_MMTU)
1189                 return;
1190 #endif
1191
1192         /*
1193          * we reject ICMPv6 too big with abnormally small value.
1194          * XXX what is the good definition of "abnormally small"?
1195          */
1196         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1197                 return;
1198
1199         if (!validated)
1200                 return;
1201
1202         /*
1203          * In case the suggested mtu is less than IPV6_MMTU, we
1204          * only need to remember that it was for above mentioned
1205          * "alwaysfrag" case.
1206          * Try to be as close to the spec as possible.
1207          */
1208         if (mtu < IPV6_MMTU)
1209                 mtu = IPV6_MMTU - 8;
1210
1211         bzero(&inc, sizeof(inc));
1212         inc.inc_fibnum = M_GETFIB(m);
1213         inc.inc_flags |= INC_ISIPV6;
1214         inc.inc6_faddr = *dst;
1215         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1216                 return;
1217
1218         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1219                 tcp_hc_updatemtu(&inc, mtu);
1220                 ICMP6STAT_INC(icp6s_pmtuchg);
1221         }
1222 }
1223
1224 /*
1225  * Process a Node Information Query packet, based on
1226  * draft-ietf-ipngwg-icmp-name-lookups-07.
1227  *
1228  * Spec incompatibilities:
1229  * - IPv6 Subject address handling
1230  * - IPv4 Subject address handling support missing
1231  * - Proxy reply (answer even if it's not for me)
1232  * - joins NI group address at in6_ifattach() time only, does not cope
1233  *   with hostname changes by sethostname(3)
1234  */
1235 static struct mbuf *
1236 ni6_input(struct mbuf *m, int off)
1237 {
1238         struct icmp6_nodeinfo *ni6, *nni6;
1239         struct mbuf *n = NULL;
1240         struct prison *pr;
1241         u_int16_t qtype;
1242         int subjlen;
1243         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1244         struct ni_reply_fqdn *fqdn;
1245         int addrs;              /* for NI_QTYPE_NODEADDR */
1246         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1247         struct in6_addr in6_subj; /* subject address */
1248         struct ip6_hdr *ip6;
1249         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1250         char *subj = NULL;
1251         struct in6_ifaddr *ia6 = NULL;
1252
1253         ip6 = mtod(m, struct ip6_hdr *);
1254 #ifndef PULLDOWN_TEST
1255         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1256 #else
1257         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1258         if (ni6 == NULL) {
1259                 /* m is already reclaimed */
1260                 return (NULL);
1261         }
1262 #endif
1263
1264         /*
1265          * Validate IPv6 source address.
1266          * The default configuration MUST be to refuse answering queries from
1267          * global-scope addresses according to RFC4602.
1268          * Notes:
1269          *  - it's not very clear what "refuse" means; this implementation
1270          *    simply drops it.
1271          *  - it's not very easy to identify global-scope (unicast) addresses
1272          *    since there are many prefixes for them.  It should be safer
1273          *    and in practice sufficient to check "all" but loopback and
1274          *    link-local (note that site-local unicast was deprecated and
1275          *    ULA is defined as global scope-wise)
1276          */
1277         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1278             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1279             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1280                 goto bad;
1281
1282         /*
1283          * Validate IPv6 destination address.
1284          *
1285          * The Responder must discard the Query without further processing
1286          * unless it is one of the Responder's unicast or anycast addresses, or
1287          * a link-local scope multicast address which the Responder has joined.
1288          * [RFC4602, Section 5.]
1289          */
1290         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1291                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1292                         goto bad;
1293                 /* else it's a link-local multicast, fine */
1294         } else {                /* unicast or anycast */
1295                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1296                 if (ia6 == NULL)
1297                         goto bad; /* XXX impossible */
1298
1299                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1300                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1301                         ifa_free(&ia6->ia_ifa);
1302                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1303                                 "a temporary address in %s:%d",
1304                                __FILE__, __LINE__));
1305                         goto bad;
1306                 }
1307                 ifa_free(&ia6->ia_ifa);
1308         }
1309
1310         /* validate query Subject field. */
1311         qtype = ntohs(ni6->ni_qtype);
1312         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1313         switch (qtype) {
1314         case NI_QTYPE_NOOP:
1315         case NI_QTYPE_SUPTYPES:
1316                 /* 07 draft */
1317                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1318                         break;
1319                 /* FALLTHROUGH */
1320         case NI_QTYPE_FQDN:
1321         case NI_QTYPE_NODEADDR:
1322         case NI_QTYPE_IPV4ADDR:
1323                 switch (ni6->ni_code) {
1324                 case ICMP6_NI_SUBJ_IPV6:
1325 #if ICMP6_NI_SUBJ_IPV6 != 0
1326                 case 0:
1327 #endif
1328                         /*
1329                          * backward compatibility - try to accept 03 draft
1330                          * format, where no Subject is present.
1331                          */
1332                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1333                             subjlen == 0) {
1334                                 oldfqdn++;
1335                                 break;
1336                         }
1337 #if ICMP6_NI_SUBJ_IPV6 != 0
1338                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1339                                 goto bad;
1340 #endif
1341
1342                         if (subjlen != sizeof(struct in6_addr))
1343                                 goto bad;
1344
1345                         /*
1346                          * Validate Subject address.
1347                          *
1348                          * Not sure what exactly "address belongs to the node"
1349                          * means in the spec, is it just unicast, or what?
1350                          *
1351                          * At this moment we consider Subject address as
1352                          * "belong to the node" if the Subject address equals
1353                          * to the IPv6 destination address; validation for
1354                          * IPv6 destination address should have done enough
1355                          * check for us.
1356                          *
1357                          * We do not do proxy at this moment.
1358                          */
1359                         /* m_pulldown instead of copy? */
1360                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1361                             subjlen, (caddr_t)&in6_subj);
1362                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1363                                 goto bad;
1364
1365                         subj = (char *)&in6_subj;
1366                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1367                                 break;
1368
1369                         /*
1370                          * XXX if we are to allow other cases, we should really
1371                          * be careful about scope here.
1372                          * basically, we should disallow queries toward IPv6
1373                          * destination X with subject Y,
1374                          * if scope(X) > scope(Y).
1375                          * if we allow scope(X) > scope(Y), it will result in
1376                          * information leakage across scope boundary.
1377                          */
1378                         goto bad;
1379
1380                 case ICMP6_NI_SUBJ_FQDN:
1381                         /*
1382                          * Validate Subject name with gethostname(3).
1383                          *
1384                          * The behavior may need some debate, since:
1385                          * - we are not sure if the node has FQDN as
1386                          *   hostname (returned by gethostname(3)).
1387                          * - the code does wildcard match for truncated names.
1388                          *   however, we are not sure if we want to perform
1389                          *   wildcard match, if gethostname(3) side has
1390                          *   truncated hostname.
1391                          */
1392                         pr = curthread->td_ucred->cr_prison;
1393                         mtx_lock(&pr->pr_mtx);
1394                         n = ni6_nametodns(pr->pr_hostname,
1395                             strlen(pr->pr_hostname), 0);
1396                         mtx_unlock(&pr->pr_mtx);
1397                         if (!n || n->m_next || n->m_len == 0)
1398                                 goto bad;
1399                         IP6_EXTHDR_GET(subj, char *, m,
1400                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1401                         if (subj == NULL)
1402                                 goto bad;
1403                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1404                             n->m_len)) {
1405                                 goto bad;
1406                         }
1407                         m_freem(n);
1408                         n = NULL;
1409                         break;
1410
1411                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1412                 default:
1413                         goto bad;
1414                 }
1415                 break;
1416         }
1417
1418         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1419         switch (qtype) {
1420         case NI_QTYPE_FQDN:
1421                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1422                         goto bad;
1423                 break;
1424         case NI_QTYPE_NODEADDR:
1425         case NI_QTYPE_IPV4ADDR:
1426                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1427                         goto bad;
1428                 break;
1429         }
1430
1431         /* guess reply length */
1432         switch (qtype) {
1433         case NI_QTYPE_NOOP:
1434                 break;          /* no reply data */
1435         case NI_QTYPE_SUPTYPES:
1436                 replylen += sizeof(u_int32_t);
1437                 break;
1438         case NI_QTYPE_FQDN:
1439                 /* XXX will append an mbuf */
1440                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1441                 break;
1442         case NI_QTYPE_NODEADDR:
1443                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1444                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1445                     sizeof(u_int32_t))) > MCLBYTES)
1446                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1447                 break;
1448         case NI_QTYPE_IPV4ADDR:
1449                 /* unsupported - should respond with unknown Qtype? */
1450                 break;
1451         default:
1452                 /*
1453                  * XXX: We must return a reply with the ICMP6 code
1454                  * `unknown Qtype' in this case.  However we regard the case
1455                  * as an FQDN query for backward compatibility.
1456                  * Older versions set a random value to this field,
1457                  * so it rarely varies in the defined qtypes.
1458                  * But the mechanism is not reliable...
1459                  * maybe we should obsolete older versions.
1460                  */
1461                 qtype = NI_QTYPE_FQDN;
1462                 /* XXX will append an mbuf */
1463                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1464                 oldfqdn++;
1465                 break;
1466         }
1467
1468         /* Allocate an mbuf to reply. */
1469         if (replylen > MCLBYTES) {
1470                 /*
1471                  * XXX: should we try to allocate more? But MCLBYTES
1472                  * is probably much larger than IPV6_MMTU...
1473                  */
1474                 goto bad;
1475         }
1476         if (replylen > MHLEN)
1477                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1478         else
1479                 n = m_gethdr(M_NOWAIT, m->m_type);
1480         if (n == NULL) {
1481                 m_freem(m);
1482                 return (NULL);
1483         }
1484         m_move_pkthdr(n, m); /* just for recvif and FIB */
1485         n->m_pkthdr.len = n->m_len = replylen;
1486
1487         /* copy mbuf header and IPv6 + Node Information base headers */
1488         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1489         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1490         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1491
1492         /* qtype dependent procedure */
1493         switch (qtype) {
1494         case NI_QTYPE_NOOP:
1495                 nni6->ni_code = ICMP6_NI_SUCCESS;
1496                 nni6->ni_flags = 0;
1497                 break;
1498         case NI_QTYPE_SUPTYPES:
1499         {
1500                 u_int32_t v;
1501                 nni6->ni_code = ICMP6_NI_SUCCESS;
1502                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1503                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1504                 v = (u_int32_t)htonl(0x0000000f);
1505                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1506                 break;
1507         }
1508         case NI_QTYPE_FQDN:
1509                 nni6->ni_code = ICMP6_NI_SUCCESS;
1510                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1511                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1512                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1513                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1514                 /*
1515                  * XXX do we really have FQDN in hostname?
1516                  */
1517                 pr = curthread->td_ucred->cr_prison;
1518                 mtx_lock(&pr->pr_mtx);
1519                 n->m_next = ni6_nametodns(pr->pr_hostname,
1520                     strlen(pr->pr_hostname), oldfqdn);
1521                 mtx_unlock(&pr->pr_mtx);
1522                 if (n->m_next == NULL)
1523                         goto bad;
1524                 /* XXX we assume that n->m_next is not a chain */
1525                 if (n->m_next->m_next != NULL)
1526                         goto bad;
1527                 n->m_pkthdr.len += n->m_next->m_len;
1528                 break;
1529         case NI_QTYPE_NODEADDR:
1530         {
1531                 int lenlim, copied;
1532
1533                 nni6->ni_code = ICMP6_NI_SUCCESS;
1534                 n->m_pkthdr.len = n->m_len =
1535                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1536                 lenlim = M_TRAILINGSPACE(n);
1537                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1538                 /* XXX: reset mbuf length */
1539                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1540                     sizeof(struct icmp6_nodeinfo) + copied;
1541                 break;
1542         }
1543         default:
1544                 break;          /* XXX impossible! */
1545         }
1546
1547         nni6->ni_type = ICMP6_NI_REPLY;
1548         m_freem(m);
1549         return (n);
1550
1551   bad:
1552         m_freem(m);
1553         if (n)
1554                 m_freem(n);
1555         return (NULL);
1556 }
1557
1558 /*
1559  * make a mbuf with DNS-encoded string.  no compression support.
1560  *
1561  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1562  * treated as truncated name (two \0 at the end).  this is a wild guess.
1563  *
1564  * old - return pascal string if non-zero
1565  */
1566 static struct mbuf *
1567 ni6_nametodns(const char *name, int namelen, int old)
1568 {
1569         struct mbuf *m;
1570         char *cp, *ep;
1571         const char *p, *q;
1572         int i, len, nterm;
1573
1574         if (old)
1575                 len = namelen + 1;
1576         else
1577                 len = MCLBYTES;
1578
1579         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1580         if (len > MLEN)
1581                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1582         else
1583                 m = m_get(M_NOWAIT, MT_DATA);
1584         if (m == NULL)
1585                 goto fail;
1586
1587         if (old) {
1588                 m->m_len = len;
1589                 *mtod(m, char *) = namelen;
1590                 bcopy(name, mtod(m, char *) + 1, namelen);
1591                 return m;
1592         } else {
1593                 m->m_len = 0;
1594                 cp = mtod(m, char *);
1595                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1596
1597                 /* if not certain about my name, return empty buffer */
1598                 if (namelen == 0)
1599                         return m;
1600
1601                 /*
1602                  * guess if it looks like shortened hostname, or FQDN.
1603                  * shortened hostname needs two trailing "\0".
1604                  */
1605                 i = 0;
1606                 for (p = name; p < name + namelen; p++) {
1607                         if (*p && *p == '.')
1608                                 i++;
1609                 }
1610                 if (i < 2)
1611                         nterm = 2;
1612                 else
1613                         nterm = 1;
1614
1615                 p = name;
1616                 while (cp < ep && p < name + namelen) {
1617                         i = 0;
1618                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1619                                 i++;
1620                         /* result does not fit into mbuf */
1621                         if (cp + i + 1 >= ep)
1622                                 goto fail;
1623                         /*
1624                          * DNS label length restriction, RFC1035 page 8.
1625                          * "i == 0" case is included here to avoid returning
1626                          * 0-length label on "foo..bar".
1627                          */
1628                         if (i <= 0 || i >= 64)
1629                                 goto fail;
1630                         *cp++ = i;
1631                         bcopy(p, cp, i);
1632                         cp += i;
1633                         p = q;
1634                         if (p < name + namelen && *p == '.')
1635                                 p++;
1636                 }
1637                 /* termination */
1638                 if (cp + nterm >= ep)
1639                         goto fail;
1640                 while (nterm-- > 0)
1641                         *cp++ = '\0';
1642                 m->m_len = cp - mtod(m, char *);
1643                 return m;
1644         }
1645
1646         panic("should not reach here");
1647         /* NOTREACHED */
1648
1649  fail:
1650         if (m)
1651                 m_freem(m);
1652         return NULL;
1653 }
1654
1655 /*
1656  * check if two DNS-encoded string matches.  takes care of truncated
1657  * form (with \0\0 at the end).  no compression support.
1658  * XXX upper/lowercase match (see RFC2065)
1659  */
1660 static int
1661 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1662 {
1663         const char *a0, *b0;
1664         int l;
1665
1666         /* simplest case - need validation? */
1667         if (alen == blen && bcmp(a, b, alen) == 0)
1668                 return 1;
1669
1670         a0 = a;
1671         b0 = b;
1672
1673         /* termination is mandatory */
1674         if (alen < 2 || blen < 2)
1675                 return 0;
1676         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1677                 return 0;
1678         alen--;
1679         blen--;
1680
1681         while (a - a0 < alen && b - b0 < blen) {
1682                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1683                         return 0;
1684
1685                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1686                         return 0;
1687                 /* we don't support compression yet */
1688                 if (a[0] >= 64 || b[0] >= 64)
1689                         return 0;
1690
1691                 /* truncated case */
1692                 if (a[0] == 0 && a - a0 == alen - 1)
1693                         return 1;
1694                 if (b[0] == 0 && b - b0 == blen - 1)
1695                         return 1;
1696                 if (a[0] == 0 || b[0] == 0)
1697                         return 0;
1698
1699                 if (a[0] != b[0])
1700                         return 0;
1701                 l = a[0];
1702                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1703                         return 0;
1704                 if (bcmp(a + 1, b + 1, l) != 0)
1705                         return 0;
1706
1707                 a += 1 + l;
1708                 b += 1 + l;
1709         }
1710
1711         if (a - a0 == alen && b - b0 == blen)
1712                 return 1;
1713         else
1714                 return 0;
1715 }
1716
1717 /*
1718  * calculate the number of addresses to be returned in the node info reply.
1719  */
1720 static int
1721 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1722     struct in6_addr *subj)
1723 {
1724         struct ifnet *ifp;
1725         struct in6_ifaddr *ifa6;
1726         struct ifaddr *ifa;
1727         int addrs = 0, addrsofif, iffound = 0;
1728         int niflags = ni6->ni_flags;
1729
1730         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1731                 switch (ni6->ni_code) {
1732                 case ICMP6_NI_SUBJ_IPV6:
1733                         if (subj == NULL) /* must be impossible... */
1734                                 return (0);
1735                         break;
1736                 default:
1737                         /*
1738                          * XXX: we only support IPv6 subject address for
1739                          * this Qtype.
1740                          */
1741                         return (0);
1742                 }
1743         }
1744
1745         IFNET_RLOCK_NOSLEEP();
1746         TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1747                 addrsofif = 0;
1748                 IF_ADDR_RLOCK(ifp);
1749                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1750                         if (ifa->ifa_addr->sa_family != AF_INET6)
1751                                 continue;
1752                         ifa6 = (struct in6_ifaddr *)ifa;
1753
1754                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1755                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1756                                 iffound = 1;
1757
1758                         /*
1759                          * IPv4-mapped addresses can only be returned by a
1760                          * Node Information proxy, since they represent
1761                          * addresses of IPv4-only nodes, which perforce do
1762                          * not implement this protocol.
1763                          * [icmp-name-lookups-07, Section 5.4]
1764                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1765                          * this function at this moment.
1766                          */
1767
1768                         /* What do we have to do about ::1? */
1769                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1770                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1771                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1772                                         continue;
1773                                 break;
1774                         case IPV6_ADDR_SCOPE_SITELOCAL:
1775                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1776                                         continue;
1777                                 break;
1778                         case IPV6_ADDR_SCOPE_GLOBAL:
1779                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1780                                         continue;
1781                                 break;
1782                         default:
1783                                 continue;
1784                         }
1785
1786                         /*
1787                          * check if anycast is okay.
1788                          * XXX: just experimental.  not in the spec.
1789                          */
1790                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1791                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1792                                 continue; /* we need only unicast addresses */
1793                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1794                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1795                                 continue;
1796                         }
1797                         addrsofif++; /* count the address */
1798                 }
1799                 IF_ADDR_RUNLOCK(ifp);
1800                 if (iffound) {
1801                         *ifpp = ifp;
1802                         IFNET_RUNLOCK_NOSLEEP();
1803                         return (addrsofif);
1804                 }
1805
1806                 addrs += addrsofif;
1807         }
1808         IFNET_RUNLOCK_NOSLEEP();
1809
1810         return (addrs);
1811 }
1812
1813 static int
1814 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1815     struct ifnet *ifp0, int resid)
1816 {
1817         struct ifnet *ifp;
1818         struct in6_ifaddr *ifa6;
1819         struct ifaddr *ifa;
1820         struct ifnet *ifp_dep = NULL;
1821         int copied = 0, allow_deprecated = 0;
1822         u_char *cp = (u_char *)(nni6 + 1);
1823         int niflags = ni6->ni_flags;
1824         u_int32_t ltime;
1825
1826         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1827                 return (0);     /* needless to copy */
1828
1829         IFNET_RLOCK_NOSLEEP();
1830         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1831   again:
1832
1833         for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) {
1834                 IF_ADDR_RLOCK(ifp);
1835                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1836                         if (ifa->ifa_addr->sa_family != AF_INET6)
1837                                 continue;
1838                         ifa6 = (struct in6_ifaddr *)ifa;
1839
1840                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1841                             allow_deprecated == 0) {
1842                                 /*
1843                                  * prefererred address should be put before
1844                                  * deprecated addresses.
1845                                  */
1846
1847                                 /* record the interface for later search */
1848                                 if (ifp_dep == NULL)
1849                                         ifp_dep = ifp;
1850
1851                                 continue;
1852                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1853                             allow_deprecated != 0)
1854                                 continue; /* we now collect deprecated addrs */
1855
1856                         /* What do we have to do about ::1? */
1857                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1858                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1859                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1860                                         continue;
1861                                 break;
1862                         case IPV6_ADDR_SCOPE_SITELOCAL:
1863                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1864                                         continue;
1865                                 break;
1866                         case IPV6_ADDR_SCOPE_GLOBAL:
1867                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1868                                         continue;
1869                                 break;
1870                         default:
1871                                 continue;
1872                         }
1873
1874                         /*
1875                          * check if anycast is okay.
1876                          * XXX: just experimental.  not in the spec.
1877                          */
1878                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1879                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1880                                 continue;
1881                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1882                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1883                                 continue;
1884                         }
1885
1886                         /* now we can copy the address */
1887                         if (resid < sizeof(struct in6_addr) +
1888                             sizeof(u_int32_t)) {
1889                                 IF_ADDR_RUNLOCK(ifp);
1890                                 /*
1891                                  * We give up much more copy.
1892                                  * Set the truncate flag and return.
1893                                  */
1894                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1895                                 IFNET_RUNLOCK_NOSLEEP();
1896                                 return (copied);
1897                         }
1898
1899                         /*
1900                          * Set the TTL of the address.
1901                          * The TTL value should be one of the following
1902                          * according to the specification:
1903                          *
1904                          * 1. The remaining lifetime of a DHCP lease on the
1905                          *    address, or
1906                          * 2. The remaining Valid Lifetime of a prefix from
1907                          *    which the address was derived through Stateless
1908                          *    Autoconfiguration.
1909                          *
1910                          * Note that we currently do not support stateful
1911                          * address configuration by DHCPv6, so the former
1912                          * case can't happen.
1913                          */
1914                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1915                                 ltime = ND6_INFINITE_LIFETIME;
1916                         else {
1917                                 if (ifa6->ia6_lifetime.ia6t_expire >
1918                                     time_uptime)
1919                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1920                                 else
1921                                         ltime = 0;
1922                         }
1923
1924                         bcopy(&ltime, cp, sizeof(u_int32_t));
1925                         cp += sizeof(u_int32_t);
1926
1927                         /* copy the address itself */
1928                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1929                             sizeof(struct in6_addr));
1930                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1931                         cp += sizeof(struct in6_addr);
1932
1933                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1934                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1935                 }
1936                 IF_ADDR_RUNLOCK(ifp);
1937                 if (ifp0)       /* we need search only on the specified IF */
1938                         break;
1939         }
1940
1941         if (allow_deprecated == 0 && ifp_dep != NULL) {
1942                 ifp = ifp_dep;
1943                 allow_deprecated = 1;
1944
1945                 goto again;
1946         }
1947
1948         IFNET_RUNLOCK_NOSLEEP();
1949
1950         return (copied);
1951 }
1952
1953 /*
1954  * XXX almost dup'ed code with rip6_input.
1955  */
1956 static int
1957 icmp6_rip6_input(struct mbuf **mp, int off)
1958 {
1959         struct mbuf *m = *mp;
1960         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1961         struct inpcb *in6p;
1962         struct inpcb *last = NULL;
1963         struct sockaddr_in6 fromsa;
1964         struct icmp6_hdr *icmp6;
1965         struct mbuf *opts = NULL;
1966
1967 #ifndef PULLDOWN_TEST
1968         /* this is assumed to be safe. */
1969         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1970 #else
1971         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1972         if (icmp6 == NULL) {
1973                 /* m is already reclaimed */
1974                 return (IPPROTO_DONE);
1975         }
1976 #endif
1977
1978         /*
1979          * XXX: the address may have embedded scope zone ID, which should be
1980          * hidden from applications.
1981          */
1982         bzero(&fromsa, sizeof(fromsa));
1983         fromsa.sin6_family = AF_INET6;
1984         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1985         fromsa.sin6_addr = ip6->ip6_src;
1986         if (sa6_recoverscope(&fromsa)) {
1987                 m_freem(m);
1988                 return (IPPROTO_DONE);
1989         }
1990
1991         INP_INFO_RLOCK(&V_ripcbinfo);
1992         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1993                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1994                         continue;
1995                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1996                         continue;
1997                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1998                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1999                         continue;
2000                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
2001                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
2002                         continue;
2003                 INP_RLOCK(in6p);
2004                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
2005                     in6p->in6p_icmp6filt)) {
2006                         INP_RUNLOCK(in6p);
2007                         continue;
2008                 }
2009                 if (last != NULL) {
2010                         struct  mbuf *n = NULL;
2011
2012                         /*
2013                          * Recent network drivers tend to allocate a single
2014                          * mbuf cluster, rather than to make a couple of
2015                          * mbufs without clusters.  Also, since the IPv6 code
2016                          * path tries to avoid m_pullup(), it is highly
2017                          * probable that we still have an mbuf cluster here
2018                          * even though the necessary length can be stored in an
2019                          * mbuf's internal buffer.
2020                          * Meanwhile, the default size of the receive socket
2021                          * buffer for raw sockets is not so large.  This means
2022                          * the possibility of packet loss is relatively higher
2023                          * than before.  To avoid this scenario, we copy the
2024                          * received data to a separate mbuf that does not use
2025                          * a cluster, if possible.
2026                          * XXX: it is better to copy the data after stripping
2027                          * intermediate headers.
2028                          */
2029                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2030                             m->m_len <= MHLEN) {
2031                                 n = m_get(M_NOWAIT, m->m_type);
2032                                 if (n != NULL) {
2033                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2034                                                 bcopy(m->m_data, n->m_data,
2035                                                       m->m_len);
2036                                                 n->m_len = m->m_len;
2037                                         } else {
2038                                                 m_free(n);
2039                                                 n = NULL;
2040                                         }
2041                                 }
2042                         }
2043                         if (n != NULL ||
2044                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2045                                 if (last->inp_flags & INP_CONTROLOPTS)
2046                                         ip6_savecontrol(last, n, &opts);
2047                                 /* strip intermediate headers */
2048                                 m_adj(n, off);
2049                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2050                                 if (sbappendaddr_locked(
2051                                     &last->inp_socket->so_rcv,
2052                                     (struct sockaddr *)&fromsa, n, opts)
2053                                     == 0) {
2054                                         /* should notify about lost packet */
2055                                         m_freem(n);
2056                                         if (opts) {
2057                                                 m_freem(opts);
2058                                         }
2059                                         SOCKBUF_UNLOCK(
2060                                             &last->inp_socket->so_rcv);
2061                                 } else
2062                                         sorwakeup_locked(last->inp_socket);
2063                                 opts = NULL;
2064                         }
2065                         INP_RUNLOCK(last);
2066                 }
2067                 last = in6p;
2068         }
2069         INP_INFO_RUNLOCK(&V_ripcbinfo);
2070         if (last != NULL) {
2071                 if (last->inp_flags & INP_CONTROLOPTS)
2072                         ip6_savecontrol(last, m, &opts);
2073                 /* strip intermediate headers */
2074                 m_adj(m, off);
2075
2076                 /* avoid using mbuf clusters if possible (see above) */
2077                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2078                     m->m_len <= MHLEN) {
2079                         struct mbuf *n;
2080
2081                         n = m_get(M_NOWAIT, m->m_type);
2082                         if (n != NULL) {
2083                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2084                                         bcopy(m->m_data, n->m_data, m->m_len);
2085                                         n->m_len = m->m_len;
2086
2087                                         m_freem(m);
2088                                         m = n;
2089                                 } else {
2090                                         m_freem(n);
2091                                         n = NULL;
2092                                 }
2093                         }
2094                 }
2095                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2096                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2097                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2098                         m_freem(m);
2099                         if (opts)
2100                                 m_freem(opts);
2101                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2102                 } else
2103                         sorwakeup_locked(last->inp_socket);
2104                 INP_RUNLOCK(last);
2105         } else {
2106                 m_freem(m);
2107                 IP6STAT_DEC(ip6s_delivered);
2108         }
2109         return IPPROTO_DONE;
2110 }
2111
2112 /*
2113  * Reflect the ip6 packet back to the source.
2114  * OFF points to the icmp6 header, counted from the top of the mbuf.
2115  */
2116 void
2117 icmp6_reflect(struct mbuf *m, size_t off)
2118 {
2119         struct in6_addr src6, *srcp;
2120         struct ip6_hdr *ip6;
2121         struct icmp6_hdr *icmp6;
2122         struct in6_ifaddr *ia = NULL;
2123         struct ifnet *outif = NULL;
2124         int plen;
2125         int type, code, hlim;
2126
2127         /* too short to reflect */
2128         if (off < sizeof(struct ip6_hdr)) {
2129                 nd6log((LOG_DEBUG,
2130                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2131                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2132                     __FILE__, __LINE__));
2133                 goto bad;
2134         }
2135
2136         /*
2137          * If there are extra headers between IPv6 and ICMPv6, strip
2138          * off that header first.
2139          */
2140 #ifdef DIAGNOSTIC
2141         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2142                 panic("assumption failed in icmp6_reflect");
2143 #endif
2144         if (off > sizeof(struct ip6_hdr)) {
2145                 size_t l;
2146                 struct ip6_hdr nip6;
2147
2148                 l = off - sizeof(struct ip6_hdr);
2149                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2150                 m_adj(m, l);
2151                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2152                 if (m->m_len < l) {
2153                         if ((m = m_pullup(m, l)) == NULL)
2154                                 return;
2155                 }
2156                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2157         } else /* off == sizeof(struct ip6_hdr) */ {
2158                 size_t l;
2159                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2160                 if (m->m_len < l) {
2161                         if ((m = m_pullup(m, l)) == NULL)
2162                                 return;
2163                 }
2164         }
2165         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2166         ip6 = mtod(m, struct ip6_hdr *);
2167         ip6->ip6_nxt = IPPROTO_ICMPV6;
2168         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2169         type = icmp6->icmp6_type; /* keep type for statistics */
2170         code = icmp6->icmp6_code; /* ditto. */
2171         hlim = 0;
2172         srcp = NULL;
2173
2174         /*
2175          * If the incoming packet was addressed directly to us (i.e. unicast),
2176          * use dst as the src for the reply.
2177          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2178          * (for example) when we encounter an error while forwarding procedure
2179          * destined to a duplicated address of ours.
2180          */
2181         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2182                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2183                 if (ia != NULL && !(ia->ia6_flags &
2184                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2185                         src6 = ia->ia_addr.sin6_addr;
2186                         srcp = &src6;
2187
2188                         if (m->m_pkthdr.rcvif != NULL) {
2189                                 /* XXX: This may not be the outgoing interface */
2190                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2191                         } else
2192                                 hlim = V_ip6_defhlim;
2193                 }
2194                 if (ia != NULL)
2195                         ifa_free(&ia->ia_ifa);
2196         }
2197
2198         if (srcp == NULL) {
2199                 int error;
2200                 struct in6_addr dst6;
2201                 uint32_t scopeid;
2202
2203                 /*
2204                  * This case matches to multicasts, our anycast, or unicasts
2205                  * that we do not own.  Select a source address based on the
2206                  * source address of the erroneous packet.
2207                  */
2208                 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
2209                 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6,
2210                     scopeid, NULL, &src6, &hlim);
2211
2212                 if (error) {
2213                         char ip6buf[INET6_ADDRSTRLEN];
2214                         nd6log((LOG_DEBUG,
2215                             "icmp6_reflect: source can't be determined: "
2216                             "dst=%s, error=%d\n",
2217                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2218                         goto bad;
2219                 }
2220                 srcp = &src6;
2221         }
2222         /*
2223          * ip6_input() drops a packet if its src is multicast.
2224          * So, the src is never multicast.
2225          */
2226         ip6->ip6_dst = ip6->ip6_src;
2227         ip6->ip6_src = *srcp;
2228         ip6->ip6_flow = 0;
2229         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2230         ip6->ip6_vfc |= IPV6_VERSION;
2231         ip6->ip6_nxt = IPPROTO_ICMPV6;
2232         ip6->ip6_hlim = hlim;
2233
2234         icmp6->icmp6_cksum = 0;
2235         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2236             sizeof(struct ip6_hdr), plen);
2237
2238         /*
2239          * XXX option handling
2240          */
2241
2242         m->m_flags &= ~(M_BCAST|M_MCAST);
2243
2244         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2245         if (outif)
2246                 icmp6_ifoutstat_inc(outif, type, code);
2247
2248         return;
2249
2250  bad:
2251         m_freem(m);
2252         return;
2253 }
2254
2255 void
2256 icmp6_fasttimo(void)
2257 {
2258
2259         mld_fasttimo();
2260 }
2261
2262 void
2263 icmp6_slowtimo(void)
2264 {
2265
2266         mld_slowtimo();
2267 }
2268
2269 static const char *
2270 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2271     struct in6_addr *tgt6)
2272 {
2273         static char buf[1024];
2274         char ip6bufs[INET6_ADDRSTRLEN];
2275         char ip6bufd[INET6_ADDRSTRLEN];
2276         char ip6buft[INET6_ADDRSTRLEN];
2277         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2278             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2279             ip6_sprintf(ip6buft, tgt6));
2280         return buf;
2281 }
2282
2283 void
2284 icmp6_redirect_input(struct mbuf *m, int off)
2285 {
2286         struct ifnet *ifp;
2287         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2288         struct nd_redirect *nd_rd;
2289         int icmp6len = ntohs(ip6->ip6_plen);
2290         char *lladdr = NULL;
2291         int lladdrlen = 0;
2292         int is_router;
2293         int is_onlink;
2294         struct in6_addr src6 = ip6->ip6_src;
2295         struct in6_addr redtgt6;
2296         struct in6_addr reddst6;
2297         union nd_opts ndopts;
2298         char ip6buf[INET6_ADDRSTRLEN];
2299
2300         M_ASSERTPKTHDR(m);
2301         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2302
2303         ifp = m->m_pkthdr.rcvif;
2304
2305         /* XXX if we are router, we don't update route by icmp6 redirect */
2306         if (V_ip6_forwarding)
2307                 goto freeit;
2308         if (!V_icmp6_rediraccept)
2309                 goto freeit;
2310
2311 #ifndef PULLDOWN_TEST
2312         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2313         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2314 #else
2315         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2316         if (nd_rd == NULL) {
2317                 ICMP6STAT_INC(icp6s_tooshort);
2318                 return;
2319         }
2320 #endif
2321         redtgt6 = nd_rd->nd_rd_target;
2322         reddst6 = nd_rd->nd_rd_dst;
2323
2324         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2325             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2326                 goto freeit;
2327         }
2328
2329         /* validation */
2330         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2331                 nd6log((LOG_ERR,
2332                     "ICMP6 redirect sent from %s rejected; "
2333                     "must be from linklocal\n",
2334                     ip6_sprintf(ip6buf, &src6)));
2335                 goto bad;
2336         }
2337         if (ip6->ip6_hlim != 255) {
2338                 nd6log((LOG_ERR,
2339                     "ICMP6 redirect sent from %s rejected; "
2340                     "hlim=%d (must be 255)\n",
2341                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2342                 goto bad;
2343         }
2344     {
2345         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2346         struct nhop6_basic nh6;
2347         struct in6_addr kdst;
2348         uint32_t scopeid;
2349
2350         in6_splitscope(&reddst6, &kdst, &scopeid);
2351         if (fib6_lookup_nh_basic(RT_DEFAULT_FIB, &kdst, scopeid, 0, 0,&nh6)==0){
2352                 if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
2353                         nd6log((LOG_ERR,
2354                             "ICMP6 redirect rejected; no route "
2355                             "with inet6 gateway found for redirect dst: %s\n",
2356                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2357                         goto bad;
2358                 }
2359
2360                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
2361                         nd6log((LOG_ERR,
2362                             "ICMP6 redirect rejected; "
2363                             "not equal to gw-for-src=%s (must be same): "
2364                             "%s\n",
2365                             ip6_sprintf(ip6buf, &nh6.nh_addr),
2366                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2367                         goto bad;
2368                 }
2369         } else {
2370                 nd6log((LOG_ERR,
2371                     "ICMP6 redirect rejected; "
2372                     "no route found for redirect dst: %s\n",
2373                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2374                 goto bad;
2375         }
2376     }
2377         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2378                 nd6log((LOG_ERR,
2379                     "ICMP6 redirect rejected; "
2380                     "redirect dst must be unicast: %s\n",
2381                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2382                 goto bad;
2383         }
2384
2385         is_router = is_onlink = 0;
2386         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2387                 is_router = 1;  /* router case */
2388         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2389                 is_onlink = 1;  /* on-link destination case */
2390         if (!is_router && !is_onlink) {
2391                 nd6log((LOG_ERR,
2392                     "ICMP6 redirect rejected; "
2393                     "neither router case nor onlink case: %s\n",
2394                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2395                 goto bad;
2396         }
2397
2398         icmp6len -= sizeof(*nd_rd);
2399         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2400         if (nd6_options(&ndopts) < 0) {
2401                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2402                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2403                 /* nd6_options have incremented stats */
2404                 goto freeit;
2405         }
2406
2407         if (ndopts.nd_opts_tgt_lladdr) {
2408                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2409                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2410         }
2411
2412         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2413                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2414                     "(if %d, icmp6 packet %d): %s\n",
2415                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2416                     ifp->if_addrlen, lladdrlen - 2,
2417                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2418                 goto bad;
2419         }
2420
2421         /* Validation passed. */
2422
2423         /* RFC 2461 8.3 */
2424         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2425             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2426
2427         /*
2428          * Install a gateway route in the better-router case or an interface
2429          * route in the on-link-destination case.
2430          */
2431         {
2432                 struct sockaddr_in6 sdst;
2433                 struct sockaddr_in6 sgw;
2434                 struct sockaddr_in6 ssrc;
2435                 struct sockaddr *gw;
2436                 int rt_flags;
2437                 u_int fibnum;
2438
2439                 bzero(&sdst, sizeof(sdst));
2440                 bzero(&ssrc, sizeof(ssrc));
2441                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2442                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2443                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2444                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2445                 rt_flags = RTF_HOST;
2446                 if (is_router) {
2447                         bzero(&sgw, sizeof(sgw));
2448                         sgw.sin6_family = AF_INET6;
2449                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2450                         bcopy(&redtgt6, &sgw.sin6_addr,
2451                                 sizeof(struct in6_addr));
2452                         gw = (struct sockaddr *)&sgw;
2453                         rt_flags |= RTF_GATEWAY;
2454                 } else
2455                         gw = ifp->if_addr->ifa_addr;
2456                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2457                         in6_rtredirect((struct sockaddr *)&sdst, gw,
2458                             (struct sockaddr *)NULL, rt_flags,
2459                             (struct sockaddr *)&ssrc, fibnum);
2460         }
2461         /* finally update cached route in each socket via pfctlinput */
2462     {
2463         struct sockaddr_in6 sdst;
2464
2465         bzero(&sdst, sizeof(sdst));
2466         sdst.sin6_family = AF_INET6;
2467         sdst.sin6_len = sizeof(struct sockaddr_in6);
2468         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2469         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2470     }
2471
2472  freeit:
2473         m_freem(m);
2474         return;
2475
2476  bad:
2477         ICMP6STAT_INC(icp6s_badredirect);
2478         m_freem(m);
2479 }
2480
2481 void
2482 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2483 {
2484         struct ifnet *ifp;      /* my outgoing interface */
2485         struct in6_addr *ifp_ll6;
2486         struct in6_addr *router_ll6;
2487         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2488         struct mbuf *m = NULL;  /* newly allocated one */
2489         struct m_tag *mtag;
2490         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2491         struct nd_redirect *nd_rd;
2492         struct llentry *ln = NULL;
2493         size_t maxlen;
2494         u_char *p;
2495         struct ifnet *outif = NULL;
2496         struct sockaddr_in6 src_sa;
2497
2498         icmp6_errcount(ND_REDIRECT, 0);
2499
2500         /* if we are not router, we don't send icmp6 redirect */
2501         if (!V_ip6_forwarding)
2502                 goto fail;
2503
2504         /* sanity check */
2505         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2506                 goto fail;
2507
2508         /*
2509          * Address check:
2510          *  the source address must identify a neighbor, and
2511          *  the destination address must not be a multicast address
2512          *  [RFC 2461, sec 8.2]
2513          */
2514         sip6 = mtod(m0, struct ip6_hdr *);
2515         bzero(&src_sa, sizeof(src_sa));
2516         src_sa.sin6_family = AF_INET6;
2517         src_sa.sin6_len = sizeof(src_sa);
2518         src_sa.sin6_addr = sip6->ip6_src;
2519         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2520                 goto fail;
2521         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2522                 goto fail;      /* what should we do here? */
2523
2524         /* rate limit */
2525         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2526                 goto fail;
2527
2528         /*
2529          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2530          * we almost always ask for an mbuf cluster for simplicity.
2531          * (MHLEN < IPV6_MMTU is almost always true)
2532          */
2533 #if IPV6_MMTU >= MCLBYTES
2534 # error assumption failed about IPV6_MMTU and MCLBYTES
2535 #endif
2536         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2537         if (m == NULL)
2538                 goto fail;
2539         M_SETFIB(m, rt->rt_fibnum);
2540         maxlen = M_TRAILINGSPACE(m);
2541         maxlen = min(IPV6_MMTU, maxlen);
2542         /* just for safety */
2543         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2544             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2545                 goto fail;
2546         }
2547
2548         {
2549                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2550                 struct in6_ifaddr *ia;
2551                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2552                                                  IN6_IFF_NOTREADY|
2553                                                  IN6_IFF_ANYCAST)) == NULL)
2554                         goto fail;
2555                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2556                 /* XXXRW: reference released prematurely. */
2557                 ifa_free(&ia->ia_ifa);
2558         }
2559
2560         /* get ip6 linklocal address for the router. */
2561         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2562                 struct sockaddr_in6 *sin6;
2563                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2564                 router_ll6 = &sin6->sin6_addr;
2565                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2566                         router_ll6 = (struct in6_addr *)NULL;
2567         } else
2568                 router_ll6 = (struct in6_addr *)NULL;
2569
2570         /* ip6 */
2571         ip6 = mtod(m, struct ip6_hdr *);
2572         ip6->ip6_flow = 0;
2573         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2574         ip6->ip6_vfc |= IPV6_VERSION;
2575         /* ip6->ip6_plen will be set later */
2576         ip6->ip6_nxt = IPPROTO_ICMPV6;
2577         ip6->ip6_hlim = 255;
2578         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2579         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2580         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2581
2582         /* ND Redirect */
2583         nd_rd = (struct nd_redirect *)(ip6 + 1);
2584         nd_rd->nd_rd_type = ND_REDIRECT;
2585         nd_rd->nd_rd_code = 0;
2586         nd_rd->nd_rd_reserved = 0;
2587         if (rt->rt_flags & RTF_GATEWAY) {
2588                 /*
2589                  * nd_rd->nd_rd_target must be a link-local address in
2590                  * better router cases.
2591                  */
2592                 if (!router_ll6)
2593                         goto fail;
2594                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2595                     sizeof(nd_rd->nd_rd_target));
2596                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2597                     sizeof(nd_rd->nd_rd_dst));
2598         } else {
2599                 /* make sure redtgt == reddst */
2600                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2601                     sizeof(nd_rd->nd_rd_target));
2602                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2603                     sizeof(nd_rd->nd_rd_dst));
2604         }
2605
2606         p = (u_char *)(nd_rd + 1);
2607
2608         if (!router_ll6)
2609                 goto nolladdropt;
2610
2611         {
2612                 /* target lladdr option */
2613                 int len;
2614                 struct nd_opt_hdr *nd_opt;
2615                 char *lladdr;
2616
2617                 IF_AFDATA_RLOCK(ifp);
2618                 ln = nd6_lookup(router_ll6, 0, ifp);
2619                 IF_AFDATA_RUNLOCK(ifp);
2620                 if (ln == NULL)
2621                         goto nolladdropt;
2622
2623                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2624                 len = (len + 7) & ~7;   /* round by 8 */
2625                 /* safety check */
2626                 if (len + (p - (u_char *)ip6) > maxlen)
2627                         goto nolladdropt;
2628
2629                 if (ln->la_flags & LLE_VALID) {
2630                         nd_opt = (struct nd_opt_hdr *)p;
2631                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2632                         nd_opt->nd_opt_len = len >> 3;
2633                         lladdr = (char *)(nd_opt + 1);
2634                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2635                         p += len;
2636                 }
2637         }
2638 nolladdropt:
2639         if (ln != NULL)
2640                 LLE_RUNLOCK(ln);
2641
2642         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2643
2644         /* just to be safe */
2645 #ifdef M_DECRYPTED      /*not openbsd*/
2646         if (m0->m_flags & M_DECRYPTED)
2647                 goto noredhdropt;
2648 #endif
2649         if (p - (u_char *)ip6 > maxlen)
2650                 goto noredhdropt;
2651
2652         {
2653                 /* redirected header option */
2654                 int len;
2655                 struct nd_opt_rd_hdr *nd_opt_rh;
2656
2657                 /*
2658                  * compute the maximum size for icmp6 redirect header option.
2659                  * XXX room for auth header?
2660                  */
2661                 len = maxlen - (p - (u_char *)ip6);
2662                 len &= ~7;
2663
2664                 /* This is just for simplicity. */
2665                 if (m0->m_pkthdr.len != m0->m_len) {
2666                         if (m0->m_next) {
2667                                 m_freem(m0->m_next);
2668                                 m0->m_next = NULL;
2669                         }
2670                         m0->m_pkthdr.len = m0->m_len;
2671                 }
2672
2673                 /*
2674                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2675                  * about padding/truncate rule for the original IP packet.
2676                  * From the discussion on IPv6imp in Feb 1999,
2677                  * the consensus was:
2678                  * - "attach as much as possible" is the goal
2679                  * - pad if not aligned (original size can be guessed by
2680                  *   original ip6 header)
2681                  * Following code adds the padding if it is simple enough,
2682                  * and truncates if not.
2683                  */
2684                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2685                         panic("assumption failed in %s:%d", __FILE__,
2686                             __LINE__);
2687
2688                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2689                         /* not enough room, truncate */
2690                         m0->m_pkthdr.len = m0->m_len = len -
2691                             sizeof(*nd_opt_rh);
2692                 } else {
2693                         /* enough room, pad or truncate */
2694                         size_t extra;
2695
2696                         extra = m0->m_pkthdr.len % 8;
2697                         if (extra) {
2698                                 /* pad if easy enough, truncate if not */
2699                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2700                                         /* pad */
2701                                         m0->m_len += (8 - extra);
2702                                         m0->m_pkthdr.len += (8 - extra);
2703                                 } else {
2704                                         /* truncate */
2705                                         m0->m_pkthdr.len -= extra;
2706                                         m0->m_len -= extra;
2707                                 }
2708                         }
2709                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2710                         m0->m_pkthdr.len = m0->m_len = len -
2711                             sizeof(*nd_opt_rh);
2712                 }
2713
2714                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2715                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2716                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2717                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2718                 p += sizeof(*nd_opt_rh);
2719                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2720
2721                 /* connect m0 to m */
2722                 m_tag_delete_chain(m0, NULL);
2723                 m0->m_flags &= ~M_PKTHDR;
2724                 m->m_next = m0;
2725                 m->m_pkthdr.len = m->m_len + m0->m_len;
2726                 m0 = NULL;
2727         }
2728 noredhdropt:;
2729         if (m0) {
2730                 m_freem(m0);
2731                 m0 = NULL;
2732         }
2733
2734         /* XXX: clear embedded link IDs in the inner header */
2735         in6_clearscope(&sip6->ip6_src);
2736         in6_clearscope(&sip6->ip6_dst);
2737         in6_clearscope(&nd_rd->nd_rd_target);
2738         in6_clearscope(&nd_rd->nd_rd_dst);
2739
2740         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2741
2742         nd_rd->nd_rd_cksum = 0;
2743         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2744             sizeof(*ip6), ntohs(ip6->ip6_plen));
2745
2746         if (send_sendso_input_hook != NULL) {
2747                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2748                         M_NOWAIT);
2749                 if (mtag == NULL)
2750                         goto fail;
2751                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2752                 m_tag_prepend(m, mtag);
2753         }
2754
2755         /* send the packet to outside... */
2756         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2757         if (outif) {
2758                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2759                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2760         }
2761         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2762
2763         return;
2764
2765 fail:
2766         if (m)
2767                 m_freem(m);
2768         if (m0)
2769                 m_freem(m0);
2770 }
2771
2772 /*
2773  * ICMPv6 socket option processing.
2774  */
2775 int
2776 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2777 {
2778         int error = 0;
2779         int optlen;
2780         struct inpcb *inp = sotoinpcb(so);
2781         int level, op, optname;
2782
2783         if (sopt) {
2784                 level = sopt->sopt_level;
2785                 op = sopt->sopt_dir;
2786                 optname = sopt->sopt_name;
2787                 optlen = sopt->sopt_valsize;
2788         } else
2789                 level = op = optname = optlen = 0;
2790
2791         if (level != IPPROTO_ICMPV6) {
2792                 return EINVAL;
2793         }
2794
2795         switch (op) {
2796         case PRCO_SETOPT:
2797                 switch (optname) {
2798                 case ICMP6_FILTER:
2799                     {
2800                         struct icmp6_filter ic6f;
2801
2802                         if (optlen != sizeof(ic6f)) {
2803                                 error = EMSGSIZE;
2804                                 break;
2805                         }
2806                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2807                         if (error == 0) {
2808                                 INP_WLOCK(inp);
2809                                 *inp->in6p_icmp6filt = ic6f;
2810                                 INP_WUNLOCK(inp);
2811                         }
2812                         break;
2813                     }
2814
2815                 default:
2816                         error = ENOPROTOOPT;
2817                         break;
2818                 }
2819                 break;
2820
2821         case PRCO_GETOPT:
2822                 switch (optname) {
2823                 case ICMP6_FILTER:
2824                     {
2825                         struct icmp6_filter ic6f;
2826
2827                         INP_RLOCK(inp);
2828                         ic6f = *inp->in6p_icmp6filt;
2829                         INP_RUNLOCK(inp);
2830                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2831                         break;
2832                     }
2833
2834                 default:
2835                         error = ENOPROTOOPT;
2836                         break;
2837                 }
2838                 break;
2839         }
2840
2841         return (error);
2842 }
2843
2844 /*
2845  * Perform rate limit check.
2846  * Returns 0 if it is okay to send the icmp6 packet.
2847  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2848  * limitation.
2849  *
2850  * XXX per-destination/type check necessary?
2851  *
2852  * dst - not used at this moment
2853  * type - not used at this moment
2854  * code - not used at this moment
2855  */
2856 static int
2857 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2858     const int code)
2859 {
2860         int ret;
2861
2862         ret = 0;        /* okay to send */
2863
2864         /* PPS limit */
2865         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2866             V_icmp6errppslim)) {
2867                 /* The packet is subject to rate limit */
2868                 ret++;
2869         }
2870
2871         return ret;
2872 }