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_ifattach.h>
 104 #include <netinet6/in6_pcb.h>
 105 #include <netinet6/ip6protosw.h>
 106 #include <netinet6/ip6_var.h>
 107 #include <netinet6/scope6_var.h>
 108 #include <netinet6/mld6_var.h>
 109 #include <netinet6/nd6.h>
 110 #include <netinet6/send.h>
 111
 112 extern struct domain inet6domain;
 113
 114 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
 115 VNET_PCPUSTAT_SYSINIT(icmp6stat);
 116
 117 #ifdef VIMAGE
 118 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
 119 #endif /* VIMAGE */
 120
 121 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 122 VNET_DECLARE(struct inpcbhead, ripcb);
 123 VNET_DECLARE(int, icmp6errppslim);
 124 static VNET_DEFINE(int, icmp6errpps_count) = 0;
 125 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 126 VNET_DECLARE(int, icmp6_nodeinfo);
 127
 128 #define V_ripcbinfo                     VNET(ripcbinfo)
 129 #define V_ripcb                         VNET(ripcb)
 130 #define V_icmp6errppslim                VNET(icmp6errppslim)
 131 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 132 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 133 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 134
 135 static void icmp6_errcount(int, int);
 136 static int icmp6_rip6_input(struct mbuf **, int);
 137 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 138 static const char *icmp6_redirect_diag(struct in6_addr *,
 139         struct in6_addr *, struct in6_addr *);
 140 static struct mbuf *ni6_input(struct mbuf *, int);
 141 static struct mbuf *ni6_nametodns(const char *, int, int);
 142 static int ni6_dnsmatch(const char *, int, const char *, int);
 143 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 144                           struct ifnet **, struct in6_addr *);
 145 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 146                                 struct ifnet *, int);
 147 static int icmp6_notify_error(struct mbuf **, int, int, int);
 148
 149 /*
 150  * Kernel module interface for updating icmp6stat.  The argument is an index
 151  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 152  * general layout of icmp6stat into the caller, it doesn't encode its
 153  * location, so that future changes to add, for example, per-CPU stats
 154  * support won't cause binary compatibility problems for kernel modules.
 155  */
 156 void
 157 kmod_icmp6stat_inc(int statnum)
 158 {
 159
 160         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 161 }
 162
 163 static void
 164 icmp6_errcount(int type, int code)
 165 {
 166         switch (type) {
 167         case ICMP6_DST_UNREACH:
 168                 switch (code) {
 169                 case ICMP6_DST_UNREACH_NOROUTE:
 170                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 171                         return;
 172                 case ICMP6_DST_UNREACH_ADMIN:
 173                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 174                         return;
 175                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 176                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 177                         return;
 178                 case ICMP6_DST_UNREACH_ADDR:
 179                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 180                         return;
 181                 case ICMP6_DST_UNREACH_NOPORT:
 182                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 183                         return;
 184                 }
 185                 break;
 186         case ICMP6_PACKET_TOO_BIG:
 187                 ICMP6STAT_INC(icp6s_opacket_too_big);
 188                 return;
 189         case ICMP6_TIME_EXCEEDED:
 190                 switch (code) {
 191                 case ICMP6_TIME_EXCEED_TRANSIT:
 192                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 193                         return;
 194                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 195                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 196                         return;
 197                 }
 198                 break;
 199         case ICMP6_PARAM_PROB:
 200                 switch (code) {
 201                 case ICMP6_PARAMPROB_HEADER:
 202                         ICMP6STAT_INC(icp6s_oparamprob_header);
 203                         return;
 204                 case ICMP6_PARAMPROB_NEXTHEADER:
 205                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 206                         return;
 207                 case ICMP6_PARAMPROB_OPTION:
 208                         ICMP6STAT_INC(icp6s_oparamprob_option);
 209                         return;
 210                 }
 211                 break;
 212         case ND_REDIRECT:
 213                 ICMP6STAT_INC(icp6s_oredirect);
 214                 return;
 215         }
 216         ICMP6STAT_INC(icp6s_ounknown);
 217 }
 218
 219 /*
 220  * A wrapper function for icmp6_error() necessary when the erroneous packet
 221  * may not contain enough scope zone information.
 222  */
 223 void
 224 icmp6_error2(struct mbuf *m, int type, int code, int param,
 225     struct ifnet *ifp)
 226 {
 227         struct ip6_hdr *ip6;
 228
 229         if (ifp == NULL)
 230                 return;
 231
 232 #ifndef PULLDOWN_TEST
 233         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 234 #else
 235         if (m->m_len < sizeof(struct ip6_hdr)) {
 236                 m = m_pullup(m, sizeof(struct ip6_hdr));
 237                 if (m == NULL)
 238                         return;
 239         }
 240 #endif
 241
 242         ip6 = mtod(m, struct ip6_hdr *);
 243
 244         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 245                 return;
 246         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 247                 return;
 248
 249         icmp6_error(m, type, code, param);
 250 }
 251
 252 /*
 253  * Generate an error packet of type error in response to bad IP6 packet.
 254  */
 255 void
 256 icmp6_error(struct mbuf *m, int type, int code, int param)
 257 {
 258         struct ip6_hdr *oip6, *nip6;
 259         struct icmp6_hdr *icmp6;
 260         u_int preplen;
 261         int off;
 262         int nxt;
 263
 264         ICMP6STAT_INC(icp6s_error);
 265
 266         /* count per-type-code statistics */
 267         icmp6_errcount(type, code);
 268
 269 #ifdef M_DECRYPTED      /*not openbsd*/
 270         if (m->m_flags & M_DECRYPTED) {
 271                 ICMP6STAT_INC(icp6s_canterror);
 272                 goto freeit;
 273         }
 274 #endif
 275
 276 #ifndef PULLDOWN_TEST
 277         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 278 #else
 279         if (m->m_len < sizeof(struct ip6_hdr)) {
 280                 m = m_pullup(m, sizeof(struct ip6_hdr));
 281                 if (m == NULL)
 282                         return;
 283         }
 284 #endif
 285         oip6 = mtod(m, struct ip6_hdr *);
 286
 287         /*
 288          * If the destination address of the erroneous packet is a multicast
 289          * address, or the packet was sent using link-layer multicast,
 290          * we should basically suppress sending an error (RFC 2463, Section
 291          * 2.4).
 292          * We have two exceptions (the item e.2 in that section):
 293          * - the Packet Too Big message can be sent for path MTU discovery.
 294          * - the Parameter Problem Message that can be allowed an icmp6 error
 295          *   in the option type field.  This check has been done in
 296          *   ip6_unknown_opt(), so we can just check the type and code.
 297          */
 298         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 299              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 300             (type != ICMP6_PACKET_TOO_BIG &&
 301              (type != ICMP6_PARAM_PROB ||
 302               code != ICMP6_PARAMPROB_OPTION)))
 303                 goto freeit;
 304
 305         /*
 306          * RFC 2463, 2.4 (e.5): source address check.
 307          * XXX: the case of anycast source?
 308          */
 309         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 310             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 311                 goto freeit;
 312
 313         /*
 314          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 315          * don't do it.
 316          */
 317         nxt = -1;
 318         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 319         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 320                 struct icmp6_hdr *icp;
 321
 322 #ifndef PULLDOWN_TEST
 323                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 324                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 325 #else
 326                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 327                         sizeof(*icp));
 328                 if (icp == NULL) {
 329                         ICMP6STAT_INC(icp6s_tooshort);
 330                         return;
 331                 }
 332 #endif
 333                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 334                     icp->icmp6_type == ND_REDIRECT) {
 335                         /*
 336                          * ICMPv6 error
 337                          * Special case: for redirect (which is
 338                          * informational) we must not send icmp6 error.
 339                          */
 340                         ICMP6STAT_INC(icp6s_canterror);
 341                         goto freeit;
 342                 } else {
 343                         /* ICMPv6 informational - send the error */
 344                 }
 345         } else {
 346                 /* non-ICMPv6 - send the error */
 347         }
 348
 349         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 350
 351         /* Finally, do rate limitation check. */
 352         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 353                 ICMP6STAT_INC(icp6s_toofreq);
 354                 goto freeit;
 355         }
 356
 357         /*
 358          * OK, ICMP6 can be generated.
 359          */
 360
 361         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 362                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 363
 364         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 365         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 366         if (m == NULL) {
 367                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 368                 return;
 369         }
 370
 371         nip6 = mtod(m, struct ip6_hdr *);
 372         nip6->ip6_src  = oip6->ip6_src;
 373         nip6->ip6_dst  = oip6->ip6_dst;
 374
 375         in6_clearscope(&oip6->ip6_src);
 376         in6_clearscope(&oip6->ip6_dst);
 377
 378         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 379         icmp6->icmp6_type = type;
 380         icmp6->icmp6_code = code;
 381         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 382
 383         /*
 384          * icmp6_reflect() is designed to be in the input path.
 385          * icmp6_error() can be called from both input and output path,
 386          * and if we are in output path rcvif could contain bogus value.
 387          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 388          * information in ip header (nip6).
 389          */
 390         m->m_pkthdr.rcvif = NULL;
 391
 392         ICMP6STAT_INC(icp6s_outhist[type]);
 393         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 394
 395         return;
 396
 397   freeit:
 398         /*
 399          * If we can't tell whether or not we can generate ICMP6, free it.
 400          */
 401         m_freem(m);
 402 }
 403
 404 /*
 405  * Process a received ICMP6 message.
 406  */
 407 int
 408 icmp6_input(struct mbuf **mp, int *offp, int proto)
 409 {
 410         struct mbuf *m = *mp, *n;
 411         struct ifnet *ifp;
 412         struct ip6_hdr *ip6, *nip6;
 413         struct icmp6_hdr *icmp6, *nicmp6;
 414         int off = *offp;
 415         int icmp6len = m->m_pkthdr.len - *offp;
 416         int code, sum, noff;
 417         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 418         int ip6len, error;
 419
 420         ifp = m->m_pkthdr.rcvif;
 421
 422 #ifndef PULLDOWN_TEST
 423         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 424         /* m might change if M_LOOP.  So, call mtod after this */
 425 #endif
 426
 427         /*
 428          * Locate icmp6 structure in mbuf, and check
 429          * that not corrupted and of at least minimum length
 430          */
 431
 432         ip6 = mtod(m, struct ip6_hdr *);
 433         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 434         if (icmp6len < sizeof(struct icmp6_hdr)) {
 435                 ICMP6STAT_INC(icp6s_tooshort);
 436                 goto freeit;
 437         }
 438
 439         /*
 440          * Check multicast group membership.
 441          * Note: SSM filters are not applied for ICMPv6 traffic.
 442          */
 443         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 444                 struct in6_multi        *inm;
 445
 446                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 447                 if (inm == NULL) {
 448                         IP6STAT_INC(ip6s_notmember);
 449                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 450                         goto freeit;
 451                 }
 452         }
 453
 454         /*
 455          * calculate the checksum
 456          */
 457 #ifndef PULLDOWN_TEST
 458         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 459 #else
 460         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 461         if (icmp6 == NULL) {
 462                 ICMP6STAT_INC(icp6s_tooshort);
 463                 return IPPROTO_DONE;
 464         }
 465 #endif
 466         code = icmp6->icmp6_code;
 467
 468         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 469                 nd6log((LOG_ERR,
 470                     "ICMP6 checksum error(%d|%x) %s\n",
 471                     icmp6->icmp6_type, sum,
 472                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 473                 ICMP6STAT_INC(icp6s_checksum);
 474                 goto freeit;
 475         }
 476
 477         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 478         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 479         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 480                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 481
 482         switch (icmp6->icmp6_type) {
 483         case ICMP6_DST_UNREACH:
 484                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 485                 switch (code) {
 486                 case ICMP6_DST_UNREACH_NOROUTE:
 487                         code = PRC_UNREACH_NET;
 488                         break;
 489                 case ICMP6_DST_UNREACH_ADMIN:
 490                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 491                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 492                         break;
 493                 case ICMP6_DST_UNREACH_ADDR:
 494                         code = PRC_HOSTDEAD;
 495                         break;
 496                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 497                         /* I mean "source address was incorrect." */
 498                         code = PRC_PARAMPROB;
 499                         break;
 500                 case ICMP6_DST_UNREACH_NOPORT:
 501                         code = PRC_UNREACH_PORT;
 502                         break;
 503                 default:
 504                         goto badcode;
 505                 }
 506                 goto deliver;
 507                 break;
 508
 509         case ICMP6_PACKET_TOO_BIG:
 510                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 511
 512                 /* validation is made in icmp6_mtudisc_update */
 513
 514                 code = PRC_MSGSIZE;
 515
 516                 /*
 517                  * Updating the path MTU will be done after examining
 518                  * intermediate extension headers.
 519                  */
 520                 goto deliver;
 521                 break;
 522
 523         case ICMP6_TIME_EXCEEDED:
 524                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 525                 switch (code) {
 526                 case ICMP6_TIME_EXCEED_TRANSIT:
 527                         code = PRC_TIMXCEED_INTRANS;
 528                         break;
 529                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 530                         code = PRC_TIMXCEED_REASS;
 531                         break;
 532                 default:
 533                         goto badcode;
 534                 }
 535                 goto deliver;
 536                 break;
 537
 538         case ICMP6_PARAM_PROB:
 539                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 540                 switch (code) {
 541                 case ICMP6_PARAMPROB_NEXTHEADER:
 542                         code = PRC_UNREACH_PROTOCOL;
 543                         break;
 544                 case ICMP6_PARAMPROB_HEADER:
 545                 case ICMP6_PARAMPROB_OPTION:
 546                         code = PRC_PARAMPROB;
 547                         break;
 548                 default:
 549                         goto badcode;
 550                 }
 551                 goto deliver;
 552                 break;
 553
 554         case ICMP6_ECHO_REQUEST:
 555                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 556                 if (code != 0)
 557                         goto badcode;
 558                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 559                         /* Give up remote */
 560                         break;
 561                 }
 562                 if (!M_WRITABLE(n)
 563                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 564                         struct mbuf *n0 = n;
 565                         int n0len;
 566
 567                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 568                         n = m_gethdr(M_NOWAIT, n0->m_type);
 569                         if (n == NULL) {
 570                                 /* Give up remote */
 571                                 m_freem(n0);
 572                                 break;
 573                         }
 574
 575                         m_move_pkthdr(n, n0);   /* FIB copied. */
 576                         n0len = n0->m_pkthdr.len;       /* save for use below */
 577                         /*
 578                          * Copy IPv6 and ICMPv6 only.
 579                          */
 580                         nip6 = mtod(n, struct ip6_hdr *);
 581                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 582                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 583                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 584                         noff = sizeof(struct ip6_hdr);
 585                         /* new mbuf contains only ipv6+icmpv6 headers */
 586                         n->m_len = noff + sizeof(struct icmp6_hdr);
 587                         /*
 588                          * Adjust mbuf.  ip6_plen will be adjusted in
 589                          * ip6_output().
 590                          */
 591                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 592                         /* recalculate complete packet size */
 593                         n->m_pkthdr.len = n0len + (noff - off);
 594                         n->m_next = n0;
 595                 } else {
 596                         nip6 = mtod(n, struct ip6_hdr *);
 597                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 598                             sizeof(*nicmp6));
 599                         noff = off;
 600                 }
 601                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 602                 nicmp6->icmp6_code = 0;
 603                 if (n) {
 604                         ICMP6STAT_INC(icp6s_reflect);
 605                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 606                         icmp6_reflect(n, noff);
 607                 }
 608                 break;
 609
 610         case ICMP6_ECHO_REPLY:
 611                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 612                 if (code != 0)
 613                         goto badcode;
 614                 break;
 615
 616         case MLD_LISTENER_QUERY:
 617         case MLD_LISTENER_REPORT:
 618         case MLD_LISTENER_DONE:
 619         case MLDV2_LISTENER_REPORT:
 620                 /*
 621                  * Drop MLD traffic which is not link-local, has a hop limit
 622                  * of greater than 1 hop, or which does not have the
 623                  * IPv6 HBH Router Alert option.
 624                  * As IPv6 HBH options are stripped in ip6_input() we must
 625                  * check an mbuf header flag.
 626                  * XXX Should we also sanity check that these messages
 627                  * were directed to a link-local multicast prefix?
 628                  */
 629                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 630                         goto freeit;
 631                 if (mld_input(m, off, icmp6len) != 0)
 632                         return (IPPROTO_DONE);
 633                 /* m stays. */
 634                 break;
 635
 636         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 637             {
 638                 enum { WRU, FQDN } mode;
 639
 640                 if (!V_icmp6_nodeinfo)
 641                         break;
 642
 643                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 644                         mode = WRU;
 645                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 646                         mode = FQDN;
 647                 else
 648                         goto badlen;
 649
 650                 if (mode == FQDN) {
 651 #ifndef PULLDOWN_TEST
 652                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 653                             IPPROTO_DONE);
 654 #endif
 655                         n = m_copy(m, 0, M_COPYALL);
 656                         if (n)
 657                                 n = ni6_input(n, off);
 658                         /* XXX meaningless if n == NULL */
 659                         noff = sizeof(struct ip6_hdr);
 660                 } else {
 661                         struct prison *pr;
 662                         u_char *p;
 663                         int maxhlen, hlen;
 664
 665                         /*
 666                          * XXX: this combination of flags is pointless,
 667                          * but should we keep this for compatibility?
 668                          */
 669                         if ((V_icmp6_nodeinfo & 5) != 5)
 670                                 break;
 671
 672                         if (code != 0)
 673                                 goto badcode;
 674
 675                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 676                         n = m_gethdr(M_NOWAIT, m->m_type);
 677                         if (n == NULL) {
 678                                 /* Give up remote */
 679                                 break;
 680                         }
 681                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 682                                 /*
 683                                  * Previous code did a blind M_COPY_PKTHDR
 684                                  * and said "just for rcvif".  If true, then
 685                                  * we could tolerate the dup failing (due to
 686                                  * the deep copy of the tag chain).  For now
 687                                  * be conservative and just fail.
 688                                  */
 689                                 m_free(n);
 690                                 n = NULL;
 691                         }
 692                         maxhlen = M_TRAILINGSPACE(n) -
 693                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 694                         pr = curthread->td_ucred->cr_prison;
 695                         mtx_lock(&pr->pr_mtx);
 696                         hlen = strlen(pr->pr_hostname);
 697                         if (maxhlen > hlen)
 698                                 maxhlen = hlen;
 699                         /*
 700                          * Copy IPv6 and ICMPv6 only.
 701                          */
 702                         nip6 = mtod(n, struct ip6_hdr *);
 703                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 704                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 705                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 706                         p = (u_char *)(nicmp6 + 1);
 707                         bzero(p, 4);
 708                         /* meaningless TTL */
 709                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 710                         mtx_unlock(&pr->pr_mtx);
 711                         noff = sizeof(struct ip6_hdr);
 712                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 713                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 714                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 715                         nicmp6->icmp6_code = 0;
 716                 }
 717                 if (n) {
 718                         ICMP6STAT_INC(icp6s_reflect);
 719                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 720                         icmp6_reflect(n, noff);
 721                 }
 722                 break;
 723             }
 724
 725         case ICMP6_WRUREPLY:
 726                 if (code != 0)
 727                         goto badcode;
 728                 break;
 729
 730         case ND_ROUTER_SOLICIT:
 731                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 732                 if (code != 0)
 733                         goto badcode;
 734                 if (icmp6len < sizeof(struct nd_router_solicit))
 735                         goto badlen;
 736                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 737                         /* give up local */
 738
 739                         /* Send incoming SeND packet to user space. */
 740                         if (send_sendso_input_hook != NULL) {
 741                                 IP6_EXTHDR_CHECK(m, off,
 742                                     icmp6len, IPPROTO_DONE);
 743                                 error = send_sendso_input_hook(m, ifp,
 744                                     SND_IN, ip6len);
 745                                 /* -1 == no app on SEND socket */
 746                                 if (error == 0)
 747                                         return (IPPROTO_DONE);
 748                                 nd6_rs_input(m, off, icmp6len);
 749                         } else
 750                                 nd6_rs_input(m, off, icmp6len);
 751                         m = NULL;
 752                         goto freeit;
 753                 }
 754                 if (send_sendso_input_hook != NULL) {
 755                         IP6_EXTHDR_CHECK(n, off,
 756                             icmp6len, IPPROTO_DONE);
 757                         error = send_sendso_input_hook(n, ifp,
 758                             SND_IN, ip6len);
 759                         if (error == 0)
 760                                 goto freeit;
 761                         /* -1 == no app on SEND socket */
 762                         nd6_rs_input(n, off, icmp6len);
 763                 } else
 764                         nd6_rs_input(n, off, icmp6len);
 765                 /* m stays. */
 766                 break;
 767
 768         case ND_ROUTER_ADVERT:
 769                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 770                 if (code != 0)
 771                         goto badcode;
 772                 if (icmp6len < sizeof(struct nd_router_advert))
 773                         goto badlen;
 774                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 775
 776                         /* Send incoming SeND-protected/ND packet to user space. */
 777                         if (send_sendso_input_hook != NULL) {
 778                                 error = send_sendso_input_hook(m, ifp,
 779                                     SND_IN, ip6len);
 780                                 if (error == 0)
 781                                         return (IPPROTO_DONE);
 782                                 nd6_ra_input(m, off, icmp6len);
 783                         } else
 784                                 nd6_ra_input(m, off, icmp6len);
 785                         m = NULL;
 786                         goto freeit;
 787                 }
 788                 if (send_sendso_input_hook != NULL) {
 789                         error = send_sendso_input_hook(n, ifp,
 790                             SND_IN, ip6len);
 791                         if (error == 0)
 792                                 goto freeit;
 793                         nd6_ra_input(n, off, icmp6len);
 794                 } else
 795                         nd6_ra_input(n, off, icmp6len);
 796                 /* m stays. */
 797                 break;
 798
 799         case ND_NEIGHBOR_SOLICIT:
 800                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 801                 if (code != 0)
 802                         goto badcode;
 803                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 804                         goto badlen;
 805                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 806                         if (send_sendso_input_hook != NULL) {
 807                                 error = send_sendso_input_hook(m, ifp,
 808                                     SND_IN, ip6len);
 809                                 if (error == 0)
 810                                         return (IPPROTO_DONE);
 811                                 nd6_ns_input(m, off, icmp6len);
 812                         } else
 813                                 nd6_ns_input(m, off, icmp6len);
 814                         m = NULL;
 815                         goto freeit;
 816                 }
 817                 if (send_sendso_input_hook != NULL) {
 818                         error = send_sendso_input_hook(n, ifp,
 819                             SND_IN, ip6len);
 820                         if (error == 0)
 821                                 goto freeit;
 822                         nd6_ns_input(n, off, icmp6len);
 823                 } else
 824                         nd6_ns_input(n, off, icmp6len);
 825                 /* m stays. */
 826                 break;
 827
 828         case ND_NEIGHBOR_ADVERT:
 829                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 830                 if (code != 0)
 831                         goto badcode;
 832                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 833                         goto badlen;
 834                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 835
 836                         /* Send incoming SeND-protected/ND packet to user space. */
 837                         if (send_sendso_input_hook != NULL) {
 838                                 error = send_sendso_input_hook(m, ifp,
 839                                     SND_IN, ip6len);
 840                                 if (error == 0)
 841                                         return (IPPROTO_DONE);
 842                                 nd6_na_input(m, off, icmp6len);
 843                         } else
 844                                 nd6_na_input(m, off, icmp6len);
 845                         m = NULL;
 846                         goto freeit;
 847                 }
 848                 if (send_sendso_input_hook != NULL) {
 849                         error = send_sendso_input_hook(n, ifp,
 850                             SND_IN, ip6len);
 851                         if (error == 0)
 852                                 goto freeit;
 853                         nd6_na_input(n, off, icmp6len);
 854                 } else
 855                         nd6_na_input(n, off, icmp6len);
 856                 /* m stays. */
 857                 break;
 858
 859         case ND_REDIRECT:
 860                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 861                 if (code != 0)
 862                         goto badcode;
 863                 if (icmp6len < sizeof(struct nd_redirect))
 864                         goto badlen;
 865                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 866                         if (send_sendso_input_hook != NULL) {
 867                                 error = send_sendso_input_hook(m, ifp,
 868                                     SND_IN, ip6len);
 869                                 if (error == 0)
 870                                         return (IPPROTO_DONE);
 871                             icmp6_redirect_input(m, off);
 872                         } else
 873                                 icmp6_redirect_input(m, off);
 874                         m = NULL;
 875                         goto freeit;
 876                 }
 877                 if (send_sendso_input_hook != NULL) {
 878                         error = send_sendso_input_hook(n, ifp,
 879                             SND_IN, ip6len);
 880                         if (error == 0)
 881                                 goto freeit;
 882                         icmp6_redirect_input(n, off);
 883                 } else
 884                         icmp6_redirect_input(n, off);
 885                 /* m stays. */
 886                 break;
 887
 888         case ICMP6_ROUTER_RENUMBERING:
 889                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 890                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 891                         goto badcode;
 892                 if (icmp6len < sizeof(struct icmp6_router_renum))
 893                         goto badlen;
 894                 break;
 895
 896         default:
 897                 nd6log((LOG_DEBUG,
 898                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 899                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 900                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 901                     ifp ? ifp->if_index : 0));
 902                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 903                         /* ICMPv6 error: MUST deliver it by spec... */
 904                         code = PRC_NCMDS;
 905                         /* deliver */
 906                 } else {
 907                         /* ICMPv6 informational: MUST not deliver */
 908                         break;
 909                 }
 910         deliver:
 911                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 912                         /* In this case, m should've been freed. */
 913                         return (IPPROTO_DONE);
 914                 }
 915                 break;
 916
 917         badcode:
 918                 ICMP6STAT_INC(icp6s_badcode);
 919                 break;
 920
 921         badlen:
 922                 ICMP6STAT_INC(icp6s_badlen);
 923                 break;
 924         }
 925
 926         /* deliver the packet to appropriate sockets */
 927         icmp6_rip6_input(&m, *offp);
 928
 929         return IPPROTO_DONE;
 930
 931  freeit:
 932         m_freem(m);
 933         return IPPROTO_DONE;
 934 }
 935
 936 static int
 937 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 938 {
 939         struct mbuf *m = *mp;
 940         struct icmp6_hdr *icmp6;
 941         struct ip6_hdr *eip6;
 942         u_int32_t notifymtu;
 943         struct sockaddr_in6 icmp6src, icmp6dst;
 944
 945         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 946                 ICMP6STAT_INC(icp6s_tooshort);
 947                 goto freeit;
 948         }
 949 #ifndef PULLDOWN_TEST
 950         IP6_EXTHDR_CHECK(m, off,
 951             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 952         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 953 #else
 954         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 955             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 956         if (icmp6 == NULL) {
 957                 ICMP6STAT_INC(icp6s_tooshort);
 958                 return (-1);
 959         }
 960 #endif
 961         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 962
 963         /* Detect the upper level protocol */
 964         {
 965                 void (*ctlfunc)(int, struct sockaddr *, void *);
 966                 u_int8_t nxt = eip6->ip6_nxt;
 967                 int eoff = off + sizeof(struct icmp6_hdr) +
 968                     sizeof(struct ip6_hdr);
 969                 struct ip6ctlparam ip6cp;
 970                 struct in6_addr *finaldst = NULL;
 971                 int icmp6type = icmp6->icmp6_type;
 972                 struct ip6_frag *fh;
 973                 struct ip6_rthdr *rth;
 974                 struct ip6_rthdr0 *rth0;
 975                 int rthlen;
 976
 977                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 978                         struct ip6_ext *eh;
 979
 980                         switch (nxt) {
 981                         case IPPROTO_HOPOPTS:
 982                         case IPPROTO_DSTOPTS:
 983                         case IPPROTO_AH:
 984 #ifndef PULLDOWN_TEST
 985                                 IP6_EXTHDR_CHECK(m, 0,
 986                                     eoff + sizeof(struct ip6_ext), -1);
 987                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 988 #else
 989                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 990                                     eoff, sizeof(*eh));
 991                                 if (eh == NULL) {
 992                                         ICMP6STAT_INC(icp6s_tooshort);
 993                                         return (-1);
 994                                 }
 995 #endif
 996
 997                                 if (nxt == IPPROTO_AH)
 998                                         eoff += (eh->ip6e_len + 2) << 2;
 999                                 else
1000                                         eoff += (eh->ip6e_len + 1) << 3;
1001                                 nxt = eh->ip6e_nxt;
1002                                 break;
1003                         case IPPROTO_ROUTING:
1004                                 /*
1005                                  * When the erroneous packet contains a
1006                                  * routing header, we should examine the
1007                                  * header to determine the final destination.
1008                                  * Otherwise, we can't properly update
1009                                  * information that depends on the final
1010                                  * destination (e.g. path MTU).
1011                                  */
1012 #ifndef PULLDOWN_TEST
1013                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1014                                 rth = (struct ip6_rthdr *)
1015                                     (mtod(m, caddr_t) + eoff);
1016 #else
1017                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1018                                     eoff, sizeof(*rth));
1019                                 if (rth == NULL) {
1020                                         ICMP6STAT_INC(icp6s_tooshort);
1021                                         return (-1);
1022                                 }
1023 #endif
1024                                 rthlen = (rth->ip6r_len + 1) << 3;
1025                                 /*
1026                                  * XXX: currently there is no
1027                                  * officially defined type other
1028                                  * than type-0.
1029                                  * Note that if the segment left field
1030                                  * is 0, all intermediate hops must
1031                                  * have been passed.
1032                                  */
1033                                 if (rth->ip6r_segleft &&
1034                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1035                                         int hops;
1036
1037 #ifndef PULLDOWN_TEST
1038                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1039                                         rth0 = (struct ip6_rthdr0 *)
1040                                             (mtod(m, caddr_t) + eoff);
1041 #else
1042                                         IP6_EXTHDR_GET(rth0,
1043                                             struct ip6_rthdr0 *, m,
1044                                             eoff, rthlen);
1045                                         if (rth0 == NULL) {
1046                                                 ICMP6STAT_INC(icp6s_tooshort);
1047                                                 return (-1);
1048                                         }
1049 #endif
1050                                         /* just ignore a bogus header */
1051                                         if ((rth0->ip6r0_len % 2) == 0 &&
1052                                             (hops = rth0->ip6r0_len/2))
1053                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1054                                 }
1055                                 eoff += rthlen;
1056                                 nxt = rth->ip6r_nxt;
1057                                 break;
1058                         case IPPROTO_FRAGMENT:
1059 #ifndef PULLDOWN_TEST
1060                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1061                                     sizeof(struct ip6_frag), -1);
1062                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1063                                     eoff);
1064 #else
1065                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1066                                     eoff, sizeof(*fh));
1067                                 if (fh == NULL) {
1068                                         ICMP6STAT_INC(icp6s_tooshort);
1069                                         return (-1);
1070                                 }
1071 #endif
1072                                 /*
1073                                  * Data after a fragment header is meaningless
1074                                  * unless it is the first fragment, but
1075                                  * we'll go to the notify label for path MTU
1076                                  * discovery.
1077                                  */
1078                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1079                                         goto notify;
1080
1081                                 eoff += sizeof(struct ip6_frag);
1082                                 nxt = fh->ip6f_nxt;
1083                                 break;
1084                         default:
1085                                 /*
1086                                  * This case includes ESP and the No Next
1087                                  * Header.  In such cases going to the notify
1088                                  * label does not have any meaning
1089                                  * (i.e. ctlfunc will be NULL), but we go
1090                                  * anyway since we might have to update
1091                                  * path MTU information.
1092                                  */
1093                                 goto notify;
1094                         }
1095                 }
1096           notify:
1097 #ifndef PULLDOWN_TEST
1098                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1099 #else
1100                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1101                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1102                 if (icmp6 == NULL) {
1103                         ICMP6STAT_INC(icp6s_tooshort);
1104                         return (-1);
1105                 }
1106 #endif
1107
1108                 /*
1109                  * retrieve parameters from the inner IPv6 header, and convert
1110                  * them into sockaddr structures.
1111                  * XXX: there is no guarantee that the source or destination
1112                  * addresses of the inner packet are in the same scope as
1113                  * the addresses of the icmp packet.  But there is no other
1114                  * way to determine the zone.
1115                  */
1116                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1117
1118                 bzero(&icmp6dst, sizeof(icmp6dst));
1119                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1120                 icmp6dst.sin6_family = AF_INET6;
1121                 if (finaldst == NULL)
1122                         icmp6dst.sin6_addr = eip6->ip6_dst;
1123                 else
1124                         icmp6dst.sin6_addr = *finaldst;
1125                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1126                         goto freeit;
1127                 bzero(&icmp6src, sizeof(icmp6src));
1128                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1129                 icmp6src.sin6_family = AF_INET6;
1130                 icmp6src.sin6_addr = eip6->ip6_src;
1131                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1132                         goto freeit;
1133                 icmp6src.sin6_flowinfo =
1134                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1135
1136                 if (finaldst == NULL)
1137                         finaldst = &eip6->ip6_dst;
1138                 ip6cp.ip6c_m = m;
1139                 ip6cp.ip6c_icmp6 = icmp6;
1140                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1141                 ip6cp.ip6c_off = eoff;
1142                 ip6cp.ip6c_finaldst = finaldst;
1143                 ip6cp.ip6c_src = &icmp6src;
1144                 ip6cp.ip6c_nxt = nxt;
1145
1146                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1147                         notifymtu = ntohl(icmp6->icmp6_mtu);
1148                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1149                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1150                 }
1151
1152                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1153                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1154                 if (ctlfunc) {
1155                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1156                             &ip6cp);
1157                 }
1158         }
1159         *mp = m;
1160         return (0);
1161
1162   freeit:
1163         m_freem(m);
1164         return (-1);
1165 }
1166
1167 void
1168 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1169 {
1170         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1171         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1172         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1173         u_int mtu = ntohl(icmp6->icmp6_mtu);
1174         struct in_conninfo inc;
1175
1176 #if 0
1177         /*
1178          * RFC2460 section 5, last paragraph.
1179          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1180          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1181          * due to packet translator in the middle.
1182          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1183          * special handling.
1184          */
1185         if (mtu < IPV6_MMTU)
1186                 return;
1187 #endif
1188
1189         /*
1190          * we reject ICMPv6 too big with abnormally small value.
1191          * XXX what is the good definition of "abnormally small"?
1192          */
1193         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1194                 return;
1195
1196         if (!validated)
1197                 return;
1198
1199         /*
1200          * In case the suggested mtu is less than IPV6_MMTU, we
1201          * only need to remember that it was for above mentioned
1202          * "alwaysfrag" case.
1203          * Try to be as close to the spec as possible.
1204          */
1205         if (mtu < IPV6_MMTU)
1206                 mtu = IPV6_MMTU - 8;
1207
1208         bzero(&inc, sizeof(inc));
1209         inc.inc_fibnum = M_GETFIB(m);
1210         inc.inc_flags |= INC_ISIPV6;
1211         inc.inc6_faddr = *dst;
1212         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1213                 return;
1214
1215         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1216                 tcp_hc_updatemtu(&inc, mtu);
1217                 ICMP6STAT_INC(icp6s_pmtuchg);
1218         }
1219 }
1220
1221 /*
1222  * Process a Node Information Query packet, based on
1223  * draft-ietf-ipngwg-icmp-name-lookups-07.
1224  *
1225  * Spec incompatibilities:
1226  * - IPv6 Subject address handling
1227  * - IPv4 Subject address handling support missing
1228  * - Proxy reply (answer even if it's not for me)
1229  * - joins NI group address at in6_ifattach() time only, does not cope
1230  *   with hostname changes by sethostname(3)
1231  */
1232 static struct mbuf *
1233 ni6_input(struct mbuf *m, int off)
1234 {
1235         struct icmp6_nodeinfo *ni6, *nni6;
1236         struct mbuf *n = NULL;
1237         struct prison *pr;
1238         u_int16_t qtype;
1239         int subjlen;
1240         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1241         struct ni_reply_fqdn *fqdn;
1242         int addrs;              /* for NI_QTYPE_NODEADDR */
1243         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1244         struct in6_addr in6_subj; /* subject address */
1245         struct ip6_hdr *ip6;
1246         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1247         char *subj = NULL;
1248         struct in6_ifaddr *ia6 = NULL;
1249
1250         ip6 = mtod(m, struct ip6_hdr *);
1251 #ifndef PULLDOWN_TEST
1252         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1253 #else
1254         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1255         if (ni6 == NULL) {
1256                 /* m is already reclaimed */
1257                 return (NULL);
1258         }
1259 #endif
1260
1261         /*
1262          * Validate IPv6 source address.
1263          * The default configuration MUST be to refuse answering queries from
1264          * global-scope addresses according to RFC4602.
1265          * Notes:
1266          *  - it's not very clear what "refuse" means; this implementation
1267          *    simply drops it.
1268          *  - it's not very easy to identify global-scope (unicast) addresses
1269          *    since there are many prefixes for them.  It should be safer
1270          *    and in practice sufficient to check "all" but loopback and
1271          *    link-local (note that site-local unicast was deprecated and
1272          *    ULA is defined as global scope-wise)
1273          */
1274         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1275             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1276             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1277                 goto bad;
1278
1279         /*
1280          * Validate IPv6 destination address.
1281          *
1282          * The Responder must discard the Query without further processing
1283          * unless it is one of the Responder's unicast or anycast addresses, or
1284          * a link-local scope multicast address which the Responder has joined.
1285          * [RFC4602, Section 5.]
1286          */
1287         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1288                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1289                         goto bad;
1290                 /* else it's a link-local multicast, fine */
1291         } else {                /* unicast or anycast */
1292                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1293                 if (ia6 == NULL)
1294                         goto bad; /* XXX impossible */
1295
1296                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1297                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1298                         ifa_free(&ia6->ia_ifa);
1299                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1300                                 "a temporary address in %s:%d",
1301                                __FILE__, __LINE__));
1302                         goto bad;
1303                 }
1304                 ifa_free(&ia6->ia_ifa);
1305         }
1306
1307         /* validate query Subject field. */
1308         qtype = ntohs(ni6->ni_qtype);
1309         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1310         switch (qtype) {
1311         case NI_QTYPE_NOOP:
1312         case NI_QTYPE_SUPTYPES:
1313                 /* 07 draft */
1314                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1315                         break;
1316                 /* FALLTHROUGH */
1317         case NI_QTYPE_FQDN:
1318         case NI_QTYPE_NODEADDR:
1319         case NI_QTYPE_IPV4ADDR:
1320                 switch (ni6->ni_code) {
1321                 case ICMP6_NI_SUBJ_IPV6:
1322 #if ICMP6_NI_SUBJ_IPV6 != 0
1323                 case 0:
1324 #endif
1325                         /*
1326                          * backward compatibility - try to accept 03 draft
1327                          * format, where no Subject is present.
1328                          */
1329                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1330                             subjlen == 0) {
1331                                 oldfqdn++;
1332                                 break;
1333                         }
1334 #if ICMP6_NI_SUBJ_IPV6 != 0
1335                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1336                                 goto bad;
1337 #endif
1338
1339                         if (subjlen != sizeof(struct in6_addr))
1340                                 goto bad;
1341
1342                         /*
1343                          * Validate Subject address.
1344                          *
1345                          * Not sure what exactly "address belongs to the node"
1346                          * means in the spec, is it just unicast, or what?
1347                          *
1348                          * At this moment we consider Subject address as
1349                          * "belong to the node" if the Subject address equals
1350                          * to the IPv6 destination address; validation for
1351                          * IPv6 destination address should have done enough
1352                          * check for us.
1353                          *
1354                          * We do not do proxy at this moment.
1355                          */
1356                         /* m_pulldown instead of copy? */
1357                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1358                             subjlen, (caddr_t)&in6_subj);
1359                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1360                                 goto bad;
1361
1362                         subj = (char *)&in6_subj;
1363                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1364                                 break;
1365
1366                         /*
1367                          * XXX if we are to allow other cases, we should really
1368                          * be careful about scope here.
1369                          * basically, we should disallow queries toward IPv6
1370                          * destination X with subject Y,
1371                          * if scope(X) > scope(Y).
1372                          * if we allow scope(X) > scope(Y), it will result in
1373                          * information leakage across scope boundary.
1374                          */
1375                         goto bad;
1376
1377                 case ICMP6_NI_SUBJ_FQDN:
1378                         /*
1379                          * Validate Subject name with gethostname(3).
1380                          *
1381                          * The behavior may need some debate, since:
1382                          * - we are not sure if the node has FQDN as
1383                          *   hostname (returned by gethostname(3)).
1384                          * - the code does wildcard match for truncated names.
1385                          *   however, we are not sure if we want to perform
1386                          *   wildcard match, if gethostname(3) side has
1387                          *   truncated hostname.
1388                          */
1389                         pr = curthread->td_ucred->cr_prison;
1390                         mtx_lock(&pr->pr_mtx);
1391                         n = ni6_nametodns(pr->pr_hostname,
1392                             strlen(pr->pr_hostname), 0);
1393                         mtx_unlock(&pr->pr_mtx);
1394                         if (!n || n->m_next || n->m_len == 0)
1395                                 goto bad;
1396                         IP6_EXTHDR_GET(subj, char *, m,
1397                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1398                         if (subj == NULL)
1399                                 goto bad;
1400                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1401                             n->m_len)) {
1402                                 goto bad;
1403                         }
1404                         m_freem(n);
1405                         n = NULL;
1406                         break;
1407
1408                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1409                 default:
1410                         goto bad;
1411                 }
1412                 break;
1413         }
1414
1415         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1416         switch (qtype) {
1417         case NI_QTYPE_FQDN:
1418                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1419                         goto bad;
1420                 break;
1421         case NI_QTYPE_NODEADDR:
1422         case NI_QTYPE_IPV4ADDR:
1423                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1424                         goto bad;
1425                 break;
1426         }
1427
1428         /* guess reply length */
1429         switch (qtype) {
1430         case NI_QTYPE_NOOP:
1431                 break;          /* no reply data */
1432         case NI_QTYPE_SUPTYPES:
1433                 replylen += sizeof(u_int32_t);
1434                 break;
1435         case NI_QTYPE_FQDN:
1436                 /* XXX will append an mbuf */
1437                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1438                 break;
1439         case NI_QTYPE_NODEADDR:
1440                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1441                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1442                     sizeof(u_int32_t))) > MCLBYTES)
1443                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1444                 break;
1445         case NI_QTYPE_IPV4ADDR:
1446                 /* unsupported - should respond with unknown Qtype? */
1447                 break;
1448         default:
1449                 /*
1450                  * XXX: We must return a reply with the ICMP6 code
1451                  * `unknown Qtype' in this case.  However we regard the case
1452                  * as an FQDN query for backward compatibility.
1453                  * Older versions set a random value to this field,
1454                  * so it rarely varies in the defined qtypes.
1455                  * But the mechanism is not reliable...
1456                  * maybe we should obsolete older versions.
1457                  */
1458                 qtype = NI_QTYPE_FQDN;
1459                 /* XXX will append an mbuf */
1460                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1461                 oldfqdn++;
1462                 break;
1463         }
1464
1465         /* Allocate an mbuf to reply. */
1466         if (replylen > MCLBYTES) {
1467                 /*
1468                  * XXX: should we try to allocate more? But MCLBYTES
1469                  * is probably much larger than IPV6_MMTU...
1470                  */
1471                 goto bad;
1472         }
1473         if (replylen > MHLEN)
1474                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1475         else
1476                 n = m_gethdr(M_NOWAIT, m->m_type);
1477         if (n == NULL) {
1478                 m_freem(m);
1479                 return (NULL);
1480         }
1481         m_move_pkthdr(n, m); /* just for recvif and FIB */
1482         n->m_pkthdr.len = n->m_len = replylen;
1483
1484         /* copy mbuf header and IPv6 + Node Information base headers */
1485         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1486         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1487         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1488
1489         /* qtype dependent procedure */
1490         switch (qtype) {
1491         case NI_QTYPE_NOOP:
1492                 nni6->ni_code = ICMP6_NI_SUCCESS;
1493                 nni6->ni_flags = 0;
1494                 break;
1495         case NI_QTYPE_SUPTYPES:
1496         {
1497                 u_int32_t v;
1498                 nni6->ni_code = ICMP6_NI_SUCCESS;
1499                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1500                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1501                 v = (u_int32_t)htonl(0x0000000f);
1502                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1503                 break;
1504         }
1505         case NI_QTYPE_FQDN:
1506                 nni6->ni_code = ICMP6_NI_SUCCESS;
1507                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1508                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1509                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1510                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1511                 /*
1512                  * XXX do we really have FQDN in hostname?
1513                  */
1514                 pr = curthread->td_ucred->cr_prison;
1515                 mtx_lock(&pr->pr_mtx);
1516                 n->m_next = ni6_nametodns(pr->pr_hostname,
1517                     strlen(pr->pr_hostname), oldfqdn);
1518                 mtx_unlock(&pr->pr_mtx);
1519                 if (n->m_next == NULL)
1520                         goto bad;
1521                 /* XXX we assume that n->m_next is not a chain */
1522                 if (n->m_next->m_next != NULL)
1523                         goto bad;
1524                 n->m_pkthdr.len += n->m_next->m_len;
1525                 break;
1526         case NI_QTYPE_NODEADDR:
1527         {
1528                 int lenlim, copied;
1529
1530                 nni6->ni_code = ICMP6_NI_SUCCESS;
1531                 n->m_pkthdr.len = n->m_len =
1532                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1533                 lenlim = M_TRAILINGSPACE(n);
1534                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1535                 /* XXX: reset mbuf length */
1536                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1537                     sizeof(struct icmp6_nodeinfo) + copied;
1538                 break;
1539         }
1540         default:
1541                 break;          /* XXX impossible! */
1542         }
1543
1544         nni6->ni_type = ICMP6_NI_REPLY;
1545         m_freem(m);
1546         return (n);
1547
1548   bad:
1549         m_freem(m);
1550         if (n)
1551                 m_freem(n);
1552         return (NULL);
1553 }
1554
1555 /*
1556  * make a mbuf with DNS-encoded string.  no compression support.
1557  *
1558  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1559  * treated as truncated name (two \0 at the end).  this is a wild guess.
1560  *
1561  * old - return pascal string if non-zero
1562  */
1563 static struct mbuf *
1564 ni6_nametodns(const char *name, int namelen, int old)
1565 {
1566         struct mbuf *m;
1567         char *cp, *ep;
1568         const char *p, *q;
1569         int i, len, nterm;
1570
1571         if (old)
1572                 len = namelen + 1;
1573         else
1574                 len = MCLBYTES;
1575
1576         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1577         if (len > MLEN)
1578                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1579         else
1580                 m = m_get(M_NOWAIT, MT_DATA);
1581         if (m == NULL)
1582                 goto fail;
1583
1584         if (old) {
1585                 m->m_len = len;
1586                 *mtod(m, char *) = namelen;
1587                 bcopy(name, mtod(m, char *) + 1, namelen);
1588                 return m;
1589         } else {
1590                 m->m_len = 0;
1591                 cp = mtod(m, char *);
1592                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1593
1594                 /* if not certain about my name, return empty buffer */
1595                 if (namelen == 0)
1596                         return m;
1597
1598                 /*
1599                  * guess if it looks like shortened hostname, or FQDN.
1600                  * shortened hostname needs two trailing "\0".
1601                  */
1602                 i = 0;
1603                 for (p = name; p < name + namelen; p++) {
1604                         if (*p && *p == '.')
1605                                 i++;
1606                 }
1607                 if (i < 2)
1608                         nterm = 2;
1609                 else
1610                         nterm = 1;
1611
1612                 p = name;
1613                 while (cp < ep && p < name + namelen) {
1614                         i = 0;
1615                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1616                                 i++;
1617                         /* result does not fit into mbuf */
1618                         if (cp + i + 1 >= ep)
1619                                 goto fail;
1620                         /*
1621                          * DNS label length restriction, RFC1035 page 8.
1622                          * "i == 0" case is included here to avoid returning
1623                          * 0-length label on "foo..bar".
1624                          */
1625                         if (i <= 0 || i >= 64)
1626                                 goto fail;
1627                         *cp++ = i;
1628                         bcopy(p, cp, i);
1629                         cp += i;
1630                         p = q;
1631                         if (p < name + namelen && *p == '.')
1632                                 p++;
1633                 }
1634                 /* termination */
1635                 if (cp + nterm >= ep)
1636                         goto fail;
1637                 while (nterm-- > 0)
1638                         *cp++ = '\0';
1639                 m->m_len = cp - mtod(m, char *);
1640                 return m;
1641         }
1642
1643         panic("should not reach here");
1644         /* NOTREACHED */
1645
1646  fail:
1647         if (m)
1648                 m_freem(m);
1649         return NULL;
1650 }
1651
1652 /*
1653  * check if two DNS-encoded string matches.  takes care of truncated
1654  * form (with \0\0 at the end).  no compression support.
1655  * XXX upper/lowercase match (see RFC2065)
1656  */
1657 static int
1658 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1659 {
1660         const char *a0, *b0;
1661         int l;
1662
1663         /* simplest case - need validation? */
1664         if (alen == blen && bcmp(a, b, alen) == 0)
1665                 return 1;
1666
1667         a0 = a;
1668         b0 = b;
1669
1670         /* termination is mandatory */
1671         if (alen < 2 || blen < 2)
1672                 return 0;
1673         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1674                 return 0;
1675         alen--;
1676         blen--;
1677
1678         while (a - a0 < alen && b - b0 < blen) {
1679                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1680                         return 0;
1681
1682                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1683                         return 0;
1684                 /* we don't support compression yet */
1685                 if (a[0] >= 64 || b[0] >= 64)
1686                         return 0;
1687
1688                 /* truncated case */
1689                 if (a[0] == 0 && a - a0 == alen - 1)
1690                         return 1;
1691                 if (b[0] == 0 && b - b0 == blen - 1)
1692                         return 1;
1693                 if (a[0] == 0 || b[0] == 0)
1694                         return 0;
1695
1696                 if (a[0] != b[0])
1697                         return 0;
1698                 l = a[0];
1699                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1700                         return 0;
1701                 if (bcmp(a + 1, b + 1, l) != 0)
1702                         return 0;
1703
1704                 a += 1 + l;
1705                 b += 1 + l;
1706         }
1707
1708         if (a - a0 == alen && b - b0 == blen)
1709                 return 1;
1710         else
1711                 return 0;
1712 }
1713
1714 /*
1715  * calculate the number of addresses to be returned in the node info reply.
1716  */
1717 static int
1718 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1719     struct in6_addr *subj)
1720 {
1721         struct ifnet *ifp;
1722         struct in6_ifaddr *ifa6;
1723         struct ifaddr *ifa;
1724         int addrs = 0, addrsofif, iffound = 0;
1725         int niflags = ni6->ni_flags;
1726
1727         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1728                 switch (ni6->ni_code) {
1729                 case ICMP6_NI_SUBJ_IPV6:
1730                         if (subj == NULL) /* must be impossible... */
1731                                 return (0);
1732                         break;
1733                 default:
1734                         /*
1735                          * XXX: we only support IPv6 subject address for
1736                          * this Qtype.
1737                          */
1738                         return (0);
1739                 }
1740         }
1741
1742         IFNET_RLOCK_NOSLEEP();
1743         TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1744                 addrsofif = 0;
1745                 IF_ADDR_RLOCK(ifp);
1746                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1747                         if (ifa->ifa_addr->sa_family != AF_INET6)
1748                                 continue;
1749                         ifa6 = (struct in6_ifaddr *)ifa;
1750
1751                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1752                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1753                                 iffound = 1;
1754
1755                         /*
1756                          * IPv4-mapped addresses can only be returned by a
1757                          * Node Information proxy, since they represent
1758                          * addresses of IPv4-only nodes, which perforce do
1759                          * not implement this protocol.
1760                          * [icmp-name-lookups-07, Section 5.4]
1761                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1762                          * this function at this moment.
1763                          */
1764
1765                         /* What do we have to do about ::1? */
1766                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1767                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1768                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1769                                         continue;
1770                                 break;
1771                         case IPV6_ADDR_SCOPE_SITELOCAL:
1772                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1773                                         continue;
1774                                 break;
1775                         case IPV6_ADDR_SCOPE_GLOBAL:
1776                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1777                                         continue;
1778                                 break;
1779                         default:
1780                                 continue;
1781                         }
1782
1783                         /*
1784                          * check if anycast is okay.
1785                          * XXX: just experimental.  not in the spec.
1786                          */
1787                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1788                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1789                                 continue; /* we need only unicast addresses */
1790                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1791                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1792                                 continue;
1793                         }
1794                         addrsofif++; /* count the address */
1795                 }
1796                 IF_ADDR_RUNLOCK(ifp);
1797                 if (iffound) {
1798                         *ifpp = ifp;
1799                         IFNET_RUNLOCK_NOSLEEP();
1800                         return (addrsofif);
1801                 }
1802
1803                 addrs += addrsofif;
1804         }
1805         IFNET_RUNLOCK_NOSLEEP();
1806
1807         return (addrs);
1808 }
1809
1810 static int
1811 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1812     struct ifnet *ifp0, int resid)
1813 {
1814         struct ifnet *ifp;
1815         struct in6_ifaddr *ifa6;
1816         struct ifaddr *ifa;
1817         struct ifnet *ifp_dep = NULL;
1818         int copied = 0, allow_deprecated = 0;
1819         u_char *cp = (u_char *)(nni6 + 1);
1820         int niflags = ni6->ni_flags;
1821         u_int32_t ltime;
1822
1823         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1824                 return (0);     /* needless to copy */
1825
1826         IFNET_RLOCK_NOSLEEP();
1827         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1828   again:
1829
1830         for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) {
1831                 IF_ADDR_RLOCK(ifp);
1832                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1833                         if (ifa->ifa_addr->sa_family != AF_INET6)
1834                                 continue;
1835                         ifa6 = (struct in6_ifaddr *)ifa;
1836
1837                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1838                             allow_deprecated == 0) {
1839                                 /*
1840                                  * prefererred address should be put before
1841                                  * deprecated addresses.
1842                                  */
1843
1844                                 /* record the interface for later search */
1845                                 if (ifp_dep == NULL)
1846                                         ifp_dep = ifp;
1847
1848                                 continue;
1849                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1850                             allow_deprecated != 0)
1851                                 continue; /* we now collect deprecated addrs */
1852
1853                         /* What do we have to do about ::1? */
1854                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1855                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1856                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1857                                         continue;
1858                                 break;
1859                         case IPV6_ADDR_SCOPE_SITELOCAL:
1860                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1861                                         continue;
1862                                 break;
1863                         case IPV6_ADDR_SCOPE_GLOBAL:
1864                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1865                                         continue;
1866                                 break;
1867                         default:
1868                                 continue;
1869                         }
1870
1871                         /*
1872                          * check if anycast is okay.
1873                          * XXX: just experimental.  not in the spec.
1874                          */
1875                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1876                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1877                                 continue;
1878                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1879                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1880                                 continue;
1881                         }
1882
1883                         /* now we can copy the address */
1884                         if (resid < sizeof(struct in6_addr) +
1885                             sizeof(u_int32_t)) {
1886                                 IF_ADDR_RUNLOCK(ifp);
1887                                 /*
1888                                  * We give up much more copy.
1889                                  * Set the truncate flag and return.
1890                                  */
1891                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1892                                 IFNET_RUNLOCK_NOSLEEP();
1893                                 return (copied);
1894                         }
1895
1896                         /*
1897                          * Set the TTL of the address.
1898                          * The TTL value should be one of the following
1899                          * according to the specification:
1900                          *
1901                          * 1. The remaining lifetime of a DHCP lease on the
1902                          *    address, or
1903                          * 2. The remaining Valid Lifetime of a prefix from
1904                          *    which the address was derived through Stateless
1905                          *    Autoconfiguration.
1906                          *
1907                          * Note that we currently do not support stateful
1908                          * address configuration by DHCPv6, so the former
1909                          * case can't happen.
1910                          */
1911                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1912                                 ltime = ND6_INFINITE_LIFETIME;
1913                         else {
1914                                 if (ifa6->ia6_lifetime.ia6t_expire >
1915                                     time_uptime)
1916                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1917                                 else
1918                                         ltime = 0;
1919                         }
1920
1921                         bcopy(&ltime, cp, sizeof(u_int32_t));
1922                         cp += sizeof(u_int32_t);
1923
1924                         /* copy the address itself */
1925                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1926                             sizeof(struct in6_addr));
1927                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1928                         cp += sizeof(struct in6_addr);
1929
1930                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1931                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1932                 }
1933                 IF_ADDR_RUNLOCK(ifp);
1934                 if (ifp0)       /* we need search only on the specified IF */
1935                         break;
1936         }
1937
1938         if (allow_deprecated == 0 && ifp_dep != NULL) {
1939                 ifp = ifp_dep;
1940                 allow_deprecated = 1;
1941
1942                 goto again;
1943         }
1944
1945         IFNET_RUNLOCK_NOSLEEP();
1946
1947         return (copied);
1948 }
1949
1950 /*
1951  * XXX almost dup'ed code with rip6_input.
1952  */
1953 static int
1954 icmp6_rip6_input(struct mbuf **mp, int off)
1955 {
1956         struct mbuf *m = *mp;
1957         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1958         struct inpcb *in6p;
1959         struct inpcb *last = NULL;
1960         struct sockaddr_in6 fromsa;
1961         struct icmp6_hdr *icmp6;
1962         struct mbuf *opts = NULL;
1963
1964 #ifndef PULLDOWN_TEST
1965         /* this is assumed to be safe. */
1966         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1967 #else
1968         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1969         if (icmp6 == NULL) {
1970                 /* m is already reclaimed */
1971                 return (IPPROTO_DONE);
1972         }
1973 #endif
1974
1975         /*
1976          * XXX: the address may have embedded scope zone ID, which should be
1977          * hidden from applications.
1978          */
1979         bzero(&fromsa, sizeof(fromsa));
1980         fromsa.sin6_family = AF_INET6;
1981         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1982         fromsa.sin6_addr = ip6->ip6_src;
1983         if (sa6_recoverscope(&fromsa)) {
1984                 m_freem(m);
1985                 return (IPPROTO_DONE);
1986         }
1987
1988         INP_INFO_RLOCK(&V_ripcbinfo);
1989         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1990                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1991                         continue;
1992                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1993                         continue;
1994                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1995                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1996                         continue;
1997                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1998                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1999                         continue;
2000                 INP_RLOCK(in6p);
2001                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
2002                     in6p->in6p_icmp6filt)) {
2003                         INP_RUNLOCK(in6p);
2004                         continue;
2005                 }
2006                 if (last != NULL) {
2007                         struct  mbuf *n = NULL;
2008
2009                         /*
2010                          * Recent network drivers tend to allocate a single
2011                          * mbuf cluster, rather than to make a couple of
2012                          * mbufs without clusters.  Also, since the IPv6 code
2013                          * path tries to avoid m_pullup(), it is highly
2014                          * probable that we still have an mbuf cluster here
2015                          * even though the necessary length can be stored in an
2016                          * mbuf's internal buffer.
2017                          * Meanwhile, the default size of the receive socket
2018                          * buffer for raw sockets is not so large.  This means
2019                          * the possibility of packet loss is relatively higher
2020                          * than before.  To avoid this scenario, we copy the
2021                          * received data to a separate mbuf that does not use
2022                          * a cluster, if possible.
2023                          * XXX: it is better to copy the data after stripping
2024                          * intermediate headers.
2025                          */
2026                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2027                             m->m_len <= MHLEN) {
2028                                 n = m_get(M_NOWAIT, m->m_type);
2029                                 if (n != NULL) {
2030                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2031                                                 bcopy(m->m_data, n->m_data,
2032                                                       m->m_len);
2033                                                 n->m_len = m->m_len;
2034                                         } else {
2035                                                 m_free(n);
2036                                                 n = NULL;
2037                                         }
2038                                 }
2039                         }
2040                         if (n != NULL ||
2041                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2042                                 if (last->inp_flags & INP_CONTROLOPTS)
2043                                         ip6_savecontrol(last, n, &opts);
2044                                 /* strip intermediate headers */
2045                                 m_adj(n, off);
2046                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2047                                 if (sbappendaddr_locked(
2048                                     &last->inp_socket->so_rcv,
2049                                     (struct sockaddr *)&fromsa, n, opts)
2050                                     == 0) {
2051                                         /* should notify about lost packet */
2052                                         m_freem(n);
2053                                         if (opts) {
2054                                                 m_freem(opts);
2055                                         }
2056                                         SOCKBUF_UNLOCK(
2057                                             &last->inp_socket->so_rcv);
2058                                 } else
2059                                         sorwakeup_locked(last->inp_socket);
2060                                 opts = NULL;
2061                         }
2062                         INP_RUNLOCK(last);
2063                 }
2064                 last = in6p;
2065         }
2066         INP_INFO_RUNLOCK(&V_ripcbinfo);
2067         if (last != NULL) {
2068                 if (last->inp_flags & INP_CONTROLOPTS)
2069                         ip6_savecontrol(last, m, &opts);
2070                 /* strip intermediate headers */
2071                 m_adj(m, off);
2072
2073                 /* avoid using mbuf clusters if possible (see above) */
2074                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2075                     m->m_len <= MHLEN) {
2076                         struct mbuf *n;
2077
2078                         n = m_get(M_NOWAIT, m->m_type);
2079                         if (n != NULL) {
2080                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2081                                         bcopy(m->m_data, n->m_data, m->m_len);
2082                                         n->m_len = m->m_len;
2083
2084                                         m_freem(m);
2085                                         m = n;
2086                                 } else {
2087                                         m_freem(n);
2088                                         n = NULL;
2089                                 }
2090                         }
2091                 }
2092                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2093                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2094                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2095                         m_freem(m);
2096                         if (opts)
2097                                 m_freem(opts);
2098                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2099                 } else
2100                         sorwakeup_locked(last->inp_socket);
2101                 INP_RUNLOCK(last);
2102         } else {
2103                 m_freem(m);
2104                 IP6STAT_DEC(ip6s_delivered);
2105         }
2106         return IPPROTO_DONE;
2107 }
2108
2109 /*
2110  * Reflect the ip6 packet back to the source.
2111  * OFF points to the icmp6 header, counted from the top of the mbuf.
2112  */
2113 void
2114 icmp6_reflect(struct mbuf *m, size_t off)
2115 {
2116         struct in6_addr src, *srcp = NULL;
2117         struct ip6_hdr *ip6;
2118         struct icmp6_hdr *icmp6;
2119         struct in6_ifaddr *ia = NULL;
2120         struct ifnet *outif = NULL;
2121         int plen;
2122         int type, code;
2123
2124         /* too short to reflect */
2125         if (off < sizeof(struct ip6_hdr)) {
2126                 nd6log((LOG_DEBUG,
2127                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2128                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2129                     __FILE__, __LINE__));
2130                 goto bad;
2131         }
2132
2133         /*
2134          * If there are extra headers between IPv6 and ICMPv6, strip
2135          * off that header first.
2136          */
2137 #ifdef DIAGNOSTIC
2138         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2139                 panic("assumption failed in icmp6_reflect");
2140 #endif
2141         if (off > sizeof(struct ip6_hdr)) {
2142                 size_t l;
2143                 struct ip6_hdr nip6;
2144
2145                 l = off - sizeof(struct ip6_hdr);
2146                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2147                 m_adj(m, l);
2148                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2149                 if (m->m_len < l) {
2150                         if ((m = m_pullup(m, l)) == NULL)
2151                                 return;
2152                 }
2153                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2154         } else /* off == sizeof(struct ip6_hdr) */ {
2155                 size_t l;
2156                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2157                 if (m->m_len < l) {
2158                         if ((m = m_pullup(m, l)) == NULL)
2159                                 return;
2160                 }
2161         }
2162         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2163         ip6 = mtod(m, struct ip6_hdr *);
2164         ip6->ip6_nxt = IPPROTO_ICMPV6;
2165         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2166         type = icmp6->icmp6_type; /* keep type for statistics */
2167         code = icmp6->icmp6_code; /* ditto. */
2168
2169         /*
2170          * If the incoming packet was addressed directly to us (i.e. unicast),
2171          * use dst as the src for the reply.
2172          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2173          * (for example) when we encounter an error while forwarding procedure
2174          * destined to a duplicated address of ours.
2175          */
2176         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2177                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2178                 if (ia != NULL && !(ia->ia6_flags &
2179                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2180                         srcp = &ia->ia_addr.sin6_addr;
2181         }
2182
2183         if (srcp == NULL) {
2184                 int e;
2185                 struct sockaddr_in6 sin6;
2186                 struct route_in6 ro;
2187
2188                 /*
2189                  * This case matches to multicasts, our anycast, or unicasts
2190                  * that we do not own.  Select a source address based on the
2191                  * source address of the erroneous packet.
2192                  */
2193                 bzero(&sin6, sizeof(sin6));
2194                 sin6.sin6_family = AF_INET6;
2195                 sin6.sin6_len = sizeof(sin6);
2196                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2197
2198                 bzero(&ro, sizeof(ro));
2199                 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2200                 if (ro.ro_rt)
2201                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2202                 if (e) {
2203                         char ip6buf[INET6_ADDRSTRLEN];
2204                         nd6log((LOG_DEBUG,
2205                             "icmp6_reflect: source can't be determined: "
2206                             "dst=%s, error=%d\n",
2207                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2208                         goto bad;
2209                 }
2210                 srcp = &src;
2211         }
2212         /*
2213          * ip6_input() drops a packet if its src is multicast.
2214          * So, the src is never multicast.
2215          */
2216         ip6->ip6_dst = ip6->ip6_src;
2217         ip6->ip6_src = *srcp;
2218         ip6->ip6_flow = 0;
2219         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2220         ip6->ip6_vfc |= IPV6_VERSION;
2221         ip6->ip6_nxt = IPPROTO_ICMPV6;
2222         if (outif)
2223                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2224         else if (m->m_pkthdr.rcvif) {
2225                 /* XXX: This may not be the outgoing interface */
2226                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2227         } else
2228                 ip6->ip6_hlim = V_ip6_defhlim;
2229
2230         icmp6->icmp6_cksum = 0;
2231         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2232             sizeof(struct ip6_hdr), plen);
2233
2234         /*
2235          * XXX option handling
2236          */
2237
2238         m->m_flags &= ~(M_BCAST|M_MCAST);
2239
2240         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2241         if (outif)
2242                 icmp6_ifoutstat_inc(outif, type, code);
2243
2244         if (ia != NULL)
2245                 ifa_free(&ia->ia_ifa);
2246         return;
2247
2248  bad:
2249         if (ia != NULL)
2250                 ifa_free(&ia->ia_ifa);
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         struct rtentry *rt = NULL;
2293         int is_router;
2294         int is_onlink;
2295         struct in6_addr src6 = ip6->ip6_src;
2296         struct in6_addr redtgt6;
2297         struct in6_addr reddst6;
2298         union nd_opts ndopts;
2299         char ip6buf[INET6_ADDRSTRLEN];
2300
2301         M_ASSERTPKTHDR(m);
2302         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2303
2304         ifp = m->m_pkthdr.rcvif;
2305
2306         /* XXX if we are router, we don't update route by icmp6 redirect */
2307         if (V_ip6_forwarding)
2308                 goto freeit;
2309         if (!V_icmp6_rediraccept)
2310                 goto freeit;
2311
2312 #ifndef PULLDOWN_TEST
2313         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2314         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2315 #else
2316         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2317         if (nd_rd == NULL) {
2318                 ICMP6STAT_INC(icp6s_tooshort);
2319                 return;
2320         }
2321 #endif
2322         redtgt6 = nd_rd->nd_rd_target;
2323         reddst6 = nd_rd->nd_rd_dst;
2324
2325         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2326             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2327                 goto freeit;
2328         }
2329
2330         /* validation */
2331         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2332                 nd6log((LOG_ERR,
2333                     "ICMP6 redirect sent from %s rejected; "
2334                     "must be from linklocal\n",
2335                     ip6_sprintf(ip6buf, &src6)));
2336                 goto bad;
2337         }
2338         if (ip6->ip6_hlim != 255) {
2339                 nd6log((LOG_ERR,
2340                     "ICMP6 redirect sent from %s rejected; "
2341                     "hlim=%d (must be 255)\n",
2342                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2343                 goto bad;
2344         }
2345     {
2346         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2347         struct sockaddr_in6 sin6;
2348         struct in6_addr *gw6;
2349
2350         bzero(&sin6, sizeof(sin6));
2351         sin6.sin6_family = AF_INET6;
2352         sin6.sin6_len = sizeof(struct sockaddr_in6);
2353         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2354         rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB);
2355         if (rt) {
2356                 if (rt->rt_gateway == NULL ||
2357                     rt->rt_gateway->sa_family != AF_INET6) {
2358                         RTFREE_LOCKED(rt);
2359                         nd6log((LOG_ERR,
2360                             "ICMP6 redirect rejected; no route "
2361                             "with inet6 gateway found for redirect dst: %s\n",
2362                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2363                         goto bad;
2364                 }
2365
2366                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2367                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2368                         RTFREE_LOCKED(rt);
2369                         nd6log((LOG_ERR,
2370                             "ICMP6 redirect rejected; "
2371                             "not equal to gw-for-src=%s (must be same): "
2372                             "%s\n",
2373                             ip6_sprintf(ip6buf, gw6),
2374                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2375                         goto bad;
2376                 }
2377         } else {
2378                 nd6log((LOG_ERR,
2379                     "ICMP6 redirect rejected; "
2380                     "no route found for redirect dst: %s\n",
2381                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2382                 goto bad;
2383         }
2384         RTFREE_LOCKED(rt);
2385         rt = NULL;
2386     }
2387         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2388                 nd6log((LOG_ERR,
2389                     "ICMP6 redirect rejected; "
2390                     "redirect dst must be unicast: %s\n",
2391                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2392                 goto bad;
2393         }
2394
2395         is_router = is_onlink = 0;
2396         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2397                 is_router = 1;  /* router case */
2398         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2399                 is_onlink = 1;  /* on-link destination case */
2400         if (!is_router && !is_onlink) {
2401                 nd6log((LOG_ERR,
2402                     "ICMP6 redirect rejected; "
2403                     "neither router case nor onlink case: %s\n",
2404                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2405                 goto bad;
2406         }
2407
2408         icmp6len -= sizeof(*nd_rd);
2409         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2410         if (nd6_options(&ndopts) < 0) {
2411                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2412                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2413                 /* nd6_options have incremented stats */
2414                 goto freeit;
2415         }
2416
2417         if (ndopts.nd_opts_tgt_lladdr) {
2418                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2419                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2420         }
2421
2422         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2423                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2424                     "(if %d, icmp6 packet %d): %s\n",
2425                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2426                     ifp->if_addrlen, lladdrlen - 2,
2427                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2428                 goto bad;
2429         }
2430
2431         /* Validation passed. */
2432
2433         /* RFC 2461 8.3 */
2434         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2435             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2436
2437         /*
2438          * Install a gateway route in the better-router case or an interface
2439          * route in the on-link-destination case.
2440          */
2441         {
2442                 struct sockaddr_in6 sdst;
2443                 struct sockaddr_in6 sgw;
2444                 struct sockaddr_in6 ssrc;
2445                 struct sockaddr *gw;
2446                 int rt_flags;
2447                 u_int fibnum;
2448
2449                 bzero(&sdst, sizeof(sdst));
2450                 bzero(&ssrc, sizeof(ssrc));
2451                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2452                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2453                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2454                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2455                 rt_flags = RTF_HOST;
2456                 if (is_router) {
2457                         bzero(&sgw, sizeof(sgw));
2458                         sgw.sin6_family = AF_INET6;
2459                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2460                         bcopy(&redtgt6, &sgw.sin6_addr,
2461                                 sizeof(struct in6_addr));
2462                         gw = (struct sockaddr *)&sgw;
2463                         rt_flags |= RTF_GATEWAY;
2464                 } else
2465                         gw = ifp->if_addr->ifa_addr;
2466                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2467                         in6_rtredirect((struct sockaddr *)&sdst, gw,
2468                             (struct sockaddr *)NULL, rt_flags,
2469                             (struct sockaddr *)&ssrc, fibnum);
2470         }
2471         /* finally update cached route in each socket via pfctlinput */
2472     {
2473         struct sockaddr_in6 sdst;
2474
2475         bzero(&sdst, sizeof(sdst));
2476         sdst.sin6_family = AF_INET6;
2477         sdst.sin6_len = sizeof(struct sockaddr_in6);
2478         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2479         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2480     }
2481
2482  freeit:
2483         m_freem(m);
2484         return;
2485
2486  bad:
2487         ICMP6STAT_INC(icp6s_badredirect);
2488         m_freem(m);
2489 }
2490
2491 void
2492 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2493 {
2494         struct ifnet *ifp;      /* my outgoing interface */
2495         struct in6_addr *ifp_ll6;
2496         struct in6_addr *router_ll6;
2497         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2498         struct mbuf *m = NULL;  /* newly allocated one */
2499         struct m_tag *mtag;
2500         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2501         struct nd_redirect *nd_rd;
2502         struct llentry *ln = NULL;
2503         size_t maxlen;
2504         u_char *p;
2505         struct ifnet *outif = NULL;
2506         struct sockaddr_in6 src_sa;
2507
2508         icmp6_errcount(ND_REDIRECT, 0);
2509
2510         /* if we are not router, we don't send icmp6 redirect */
2511         if (!V_ip6_forwarding)
2512                 goto fail;
2513
2514         /* sanity check */
2515         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2516                 goto fail;
2517
2518         /*
2519          * Address check:
2520          *  the source address must identify a neighbor, and
2521          *  the destination address must not be a multicast address
2522          *  [RFC 2461, sec 8.2]
2523          */
2524         sip6 = mtod(m0, struct ip6_hdr *);
2525         bzero(&src_sa, sizeof(src_sa));
2526         src_sa.sin6_family = AF_INET6;
2527         src_sa.sin6_len = sizeof(src_sa);
2528         src_sa.sin6_addr = sip6->ip6_src;
2529         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2530                 goto fail;
2531         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2532                 goto fail;      /* what should we do here? */
2533
2534         /* rate limit */
2535         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2536                 goto fail;
2537
2538         /*
2539          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2540          * we almost always ask for an mbuf cluster for simplicity.
2541          * (MHLEN < IPV6_MMTU is almost always true)
2542          */
2543 #if IPV6_MMTU >= MCLBYTES
2544 # error assumption failed about IPV6_MMTU and MCLBYTES
2545 #endif
2546         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2547         if (m == NULL)
2548                 goto fail;
2549         M_SETFIB(m, rt->rt_fibnum);
2550         maxlen = M_TRAILINGSPACE(m);
2551         maxlen = min(IPV6_MMTU, maxlen);
2552         /* just for safety */
2553         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2554             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2555                 goto fail;
2556         }
2557
2558         {
2559                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2560                 struct in6_ifaddr *ia;
2561                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2562                                                  IN6_IFF_NOTREADY|
2563                                                  IN6_IFF_ANYCAST)) == NULL)
2564                         goto fail;
2565                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2566                 /* XXXRW: reference released prematurely. */
2567                 ifa_free(&ia->ia_ifa);
2568         }
2569
2570         /* get ip6 linklocal address for the router. */
2571         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2572                 struct sockaddr_in6 *sin6;
2573                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2574                 router_ll6 = &sin6->sin6_addr;
2575                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2576                         router_ll6 = (struct in6_addr *)NULL;
2577         } else
2578                 router_ll6 = (struct in6_addr *)NULL;
2579
2580         /* ip6 */
2581         ip6 = mtod(m, struct ip6_hdr *);
2582         ip6->ip6_flow = 0;
2583         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2584         ip6->ip6_vfc |= IPV6_VERSION;
2585         /* ip6->ip6_plen will be set later */
2586         ip6->ip6_nxt = IPPROTO_ICMPV6;
2587         ip6->ip6_hlim = 255;
2588         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2589         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2590         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2591
2592         /* ND Redirect */
2593         nd_rd = (struct nd_redirect *)(ip6 + 1);
2594         nd_rd->nd_rd_type = ND_REDIRECT;
2595         nd_rd->nd_rd_code = 0;
2596         nd_rd->nd_rd_reserved = 0;
2597         if (rt->rt_flags & RTF_GATEWAY) {
2598                 /*
2599                  * nd_rd->nd_rd_target must be a link-local address in
2600                  * better router cases.
2601                  */
2602                 if (!router_ll6)
2603                         goto fail;
2604                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2605                     sizeof(nd_rd->nd_rd_target));
2606                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2607                     sizeof(nd_rd->nd_rd_dst));
2608         } else {
2609                 /* make sure redtgt == reddst */
2610                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2611                     sizeof(nd_rd->nd_rd_target));
2612                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2613                     sizeof(nd_rd->nd_rd_dst));
2614         }
2615
2616         p = (u_char *)(nd_rd + 1);
2617
2618         if (!router_ll6)
2619                 goto nolladdropt;
2620
2621         {
2622                 /* target lladdr option */
2623                 int len;
2624                 struct nd_opt_hdr *nd_opt;
2625                 char *lladdr;
2626
2627                 IF_AFDATA_RLOCK(ifp);
2628                 ln = nd6_lookup(router_ll6, 0, ifp);
2629                 IF_AFDATA_RUNLOCK(ifp);
2630                 if (ln == NULL)
2631                         goto nolladdropt;
2632
2633                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2634                 len = (len + 7) & ~7;   /* round by 8 */
2635                 /* safety check */
2636                 if (len + (p - (u_char *)ip6) > maxlen)
2637                         goto nolladdropt;
2638
2639                 if (ln->la_flags & LLE_VALID) {
2640                         nd_opt = (struct nd_opt_hdr *)p;
2641                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2642                         nd_opt->nd_opt_len = len >> 3;
2643                         lladdr = (char *)(nd_opt + 1);
2644                         bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2645                         p += len;
2646                 }
2647         }
2648 nolladdropt:
2649         if (ln != NULL)
2650                 LLE_RUNLOCK(ln);
2651
2652         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2653
2654         /* just to be safe */
2655 #ifdef M_DECRYPTED      /*not openbsd*/
2656         if (m0->m_flags & M_DECRYPTED)
2657                 goto noredhdropt;
2658 #endif
2659         if (p - (u_char *)ip6 > maxlen)
2660                 goto noredhdropt;
2661
2662         {
2663                 /* redirected header option */
2664                 int len;
2665                 struct nd_opt_rd_hdr *nd_opt_rh;
2666
2667                 /*
2668                  * compute the maximum size for icmp6 redirect header option.
2669                  * XXX room for auth header?
2670                  */
2671                 len = maxlen - (p - (u_char *)ip6);
2672                 len &= ~7;
2673
2674                 /* This is just for simplicity. */
2675                 if (m0->m_pkthdr.len != m0->m_len) {
2676                         if (m0->m_next) {
2677                                 m_freem(m0->m_next);
2678                                 m0->m_next = NULL;
2679                         }
2680                         m0->m_pkthdr.len = m0->m_len;
2681                 }
2682
2683                 /*
2684                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2685                  * about padding/truncate rule for the original IP packet.
2686                  * From the discussion on IPv6imp in Feb 1999,
2687                  * the consensus was:
2688                  * - "attach as much as possible" is the goal
2689                  * - pad if not aligned (original size can be guessed by
2690                  *   original ip6 header)
2691                  * Following code adds the padding if it is simple enough,
2692                  * and truncates if not.
2693                  */
2694                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2695                         panic("assumption failed in %s:%d", __FILE__,
2696                             __LINE__);
2697
2698                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2699                         /* not enough room, truncate */
2700                         m0->m_pkthdr.len = m0->m_len = len -
2701                             sizeof(*nd_opt_rh);
2702                 } else {
2703                         /* enough room, pad or truncate */
2704                         size_t extra;
2705
2706                         extra = m0->m_pkthdr.len % 8;
2707                         if (extra) {
2708                                 /* pad if easy enough, truncate if not */
2709                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2710                                         /* pad */
2711                                         m0->m_len += (8 - extra);
2712                                         m0->m_pkthdr.len += (8 - extra);
2713                                 } else {
2714                                         /* truncate */
2715                                         m0->m_pkthdr.len -= extra;
2716                                         m0->m_len -= extra;
2717                                 }
2718                         }
2719                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2720                         m0->m_pkthdr.len = m0->m_len = len -
2721                             sizeof(*nd_opt_rh);
2722                 }
2723
2724                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2725                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2726                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2727                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2728                 p += sizeof(*nd_opt_rh);
2729                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2730
2731                 /* connect m0 to m */
2732                 m_tag_delete_chain(m0, NULL);
2733                 m0->m_flags &= ~M_PKTHDR;
2734                 m->m_next = m0;
2735                 m->m_pkthdr.len = m->m_len + m0->m_len;
2736                 m0 = NULL;
2737         }
2738 noredhdropt:;
2739         if (m0) {
2740                 m_freem(m0);
2741                 m0 = NULL;
2742         }
2743
2744         /* XXX: clear embedded link IDs in the inner header */
2745         in6_clearscope(&sip6->ip6_src);
2746         in6_clearscope(&sip6->ip6_dst);
2747         in6_clearscope(&nd_rd->nd_rd_target);
2748         in6_clearscope(&nd_rd->nd_rd_dst);
2749
2750         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2751
2752         nd_rd->nd_rd_cksum = 0;
2753         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2754             sizeof(*ip6), ntohs(ip6->ip6_plen));
2755
2756         if (send_sendso_input_hook != NULL) {
2757                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2758                         M_NOWAIT);
2759                 if (mtag == NULL)
2760                         goto fail;
2761                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2762                 m_tag_prepend(m, mtag);
2763         }
2764
2765         /* send the packet to outside... */
2766         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2767         if (outif) {
2768                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2769                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2770         }
2771         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2772
2773         return;
2774
2775 fail:
2776         if (m)
2777                 m_freem(m);
2778         if (m0)
2779                 m_freem(m0);
2780 }
2781
2782 /*
2783  * ICMPv6 socket option processing.
2784  */
2785 int
2786 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2787 {
2788         int error = 0;
2789         int optlen;
2790         struct inpcb *inp = sotoinpcb(so);
2791         int level, op, optname;
2792
2793         if (sopt) {
2794                 level = sopt->sopt_level;
2795                 op = sopt->sopt_dir;
2796                 optname = sopt->sopt_name;
2797                 optlen = sopt->sopt_valsize;
2798         } else
2799                 level = op = optname = optlen = 0;
2800
2801         if (level != IPPROTO_ICMPV6) {
2802                 return EINVAL;
2803         }
2804
2805         switch (op) {
2806         case PRCO_SETOPT:
2807                 switch (optname) {
2808                 case ICMP6_FILTER:
2809                     {
2810                         struct icmp6_filter ic6f;
2811
2812                         if (optlen != sizeof(ic6f)) {
2813                                 error = EMSGSIZE;
2814                                 break;
2815                         }
2816                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2817                         if (error == 0) {
2818                                 INP_WLOCK(inp);
2819                                 *inp->in6p_icmp6filt = ic6f;
2820                                 INP_WUNLOCK(inp);
2821                         }
2822                         break;
2823                     }
2824
2825                 default:
2826                         error = ENOPROTOOPT;
2827                         break;
2828                 }
2829                 break;
2830
2831         case PRCO_GETOPT:
2832                 switch (optname) {
2833                 case ICMP6_FILTER:
2834                     {
2835                         struct icmp6_filter ic6f;
2836
2837                         INP_RLOCK(inp);
2838                         ic6f = *inp->in6p_icmp6filt;
2839                         INP_RUNLOCK(inp);
2840                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2841                         break;
2842                     }
2843
2844                 default:
2845                         error = ENOPROTOOPT;
2846                         break;
2847                 }
2848                 break;
2849         }
2850
2851         return (error);
2852 }
2853
2854 /*
2855  * Perform rate limit check.
2856  * Returns 0 if it is okay to send the icmp6 packet.
2857  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2858  * limitation.
2859  *
2860  * XXX per-destination/type check necessary?
2861  *
2862  * dst - not used at this moment
2863  * type - not used at this moment
2864  * code - not used at this moment
2865  */
2866 static int
2867 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2868     const int code)
2869 {
2870         int ret;
2871
2872         ret = 0;        /* okay to send */
2873
2874         /* PPS limit */
2875         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2876             V_icmp6errppslim)) {
2877                 /* The packet is subject to rate limit */
2878                 ret++;
2879         }
2880
2881         return ret;
2882 }