sys/netinet6/icmp6.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipsec.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/domain.h>
  72 #include <sys/jail.h>
  73 #include <sys/kernel.h>
  74 #include <sys/lock.h>
  75 #include <sys/malloc.h>
  76 #include <sys/mbuf.h>
  77 #include <sys/proc.h>
  78 #include <sys/protosw.h>
  79 #include <sys/signalvar.h>
  80 #include <sys/socket.h>
  81 #include <sys/socketvar.h>
  82 #include <sys/sx.h>
  83 #include <sys/syslog.h>
  84 #include <sys/systm.h>
  85 #include <sys/time.h>
  86
  87 #include <net/if.h>
  88 #include <net/if_dl.h>
  89 #include <net/if_llatbl.h>
  90 #include <net/if_types.h>
  91 #include <net/route.h>
  92 #include <net/vnet.h>
  93
  94 #include <netinet/in.h>
  95 #include <netinet/in_pcb.h>
  96 #include <netinet/in_var.h>
  97 #include <netinet/ip6.h>
  98 #include <netinet/icmp6.h>
  99 #include <netinet/tcp_var.h>
 100
 101 #include <netinet6/in6_ifattach.h>
 102 #include <netinet6/in6_pcb.h>
 103 #include <netinet6/ip6protosw.h>
 104 #include <netinet6/ip6_var.h>
 105 #include <netinet6/scope6_var.h>
 106 #include <netinet6/mld6_var.h>
 107 #include <netinet6/nd6.h>
 108
 109 #ifdef IPSEC
 110 #include <netipsec/ipsec.h>
 111 #include <netipsec/key.h>
 112 #endif
 113
 114 extern struct domain inet6domain;
 115
 116 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 117 VNET_DECLARE(struct inpcbhead, ripcb);
 118 VNET_DECLARE(int, icmp6errppslim);
 119 VNET_DECLARE(int, icmp6_nodeinfo);
 120
 121 #define V_ripcbinfo                     VNET(ripcbinfo)
 122 #define V_ripcb                         VNET(ripcb)
 123 #define V_icmp6errppslim                VNET(icmp6errppslim)
 124 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 125
 126 VNET_DEFINE(struct icmp6stat, icmp6stat);
 127 static VNET_DEFINE(int, icmp6errpps_count);
 128 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 129
 130 #define V_icmp6errpps_count     VNET(icmp6errpps_count)
 131 #define V_icmp6errppslim_last   VNET(icmp6errppslim_last)
 132
 133 static void icmp6_errcount(struct icmp6errstat *, int, int);
 134 static int icmp6_rip6_input(struct mbuf **, int);
 135 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 136 static const char *icmp6_redirect_diag __P((struct in6_addr *,
 137         struct in6_addr *, struct in6_addr *));
 138 static struct mbuf *ni6_input(struct mbuf *, int);
 139 static struct mbuf *ni6_nametodns(const char *, int, int);
 140 static int ni6_dnsmatch(const char *, int, const char *, int);
 141 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
 142                           struct ifnet **, struct in6_addr *));
 143 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 144                                 struct ifnet *, int));
 145 static int icmp6_notify_error(struct mbuf **, int, int, int);
 146
 147
 148 void
 149 icmp6_init(void)
 150 {
 151
 152         V_icmp6errpps_count = 0;
 153 }
 154
 155 /*
 156  * Kernel module interface for updating icmp6stat.  The argument is an index
 157  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 158  * general layout of icmp6stat into the caller, it doesn't encode its
 159  * location, so that future changes to add, for example, per-CPU stats
 160  * support won't cause binary compatibility problems for kernel modules.
 161  */
 162 void
 163 kmod_icmp6stat_inc(int statnum)
 164 {
 165
 166         (*((u_quad_t *)&V_icmp6stat + statnum))++;
 167 }
 168
 169 static void
 170 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
 171 {
 172         switch (type) {
 173         case ICMP6_DST_UNREACH:
 174                 switch (code) {
 175                 case ICMP6_DST_UNREACH_NOROUTE:
 176                         stat->icp6errs_dst_unreach_noroute++;
 177                         return;
 178                 case ICMP6_DST_UNREACH_ADMIN:
 179                         stat->icp6errs_dst_unreach_admin++;
 180                         return;
 181                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 182                         stat->icp6errs_dst_unreach_beyondscope++;
 183                         return;
 184                 case ICMP6_DST_UNREACH_ADDR:
 185                         stat->icp6errs_dst_unreach_addr++;
 186                         return;
 187                 case ICMP6_DST_UNREACH_NOPORT:
 188                         stat->icp6errs_dst_unreach_noport++;
 189                         return;
 190                 }
 191                 break;
 192         case ICMP6_PACKET_TOO_BIG:
 193                 stat->icp6errs_packet_too_big++;
 194                 return;
 195         case ICMP6_TIME_EXCEEDED:
 196                 switch (code) {
 197                 case ICMP6_TIME_EXCEED_TRANSIT:
 198                         stat->icp6errs_time_exceed_transit++;
 199                         return;
 200                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 201                         stat->icp6errs_time_exceed_reassembly++;
 202                         return;
 203                 }
 204                 break;
 205         case ICMP6_PARAM_PROB:
 206                 switch (code) {
 207                 case ICMP6_PARAMPROB_HEADER:
 208                         stat->icp6errs_paramprob_header++;
 209                         return;
 210                 case ICMP6_PARAMPROB_NEXTHEADER:
 211                         stat->icp6errs_paramprob_nextheader++;
 212                         return;
 213                 case ICMP6_PARAMPROB_OPTION:
 214                         stat->icp6errs_paramprob_option++;
 215                         return;
 216                 }
 217                 break;
 218         case ND_REDIRECT:
 219                 stat->icp6errs_redirect++;
 220                 return;
 221         }
 222         stat->icp6errs_unknown++;
 223 }
 224
 225 /*
 226  * A wrapper function for icmp6_error() necessary when the erroneous packet
 227  * may not contain enough scope zone information.
 228  */
 229 void
 230 icmp6_error2(struct mbuf *m, int type, int code, int param,
 231     struct ifnet *ifp)
 232 {
 233         struct ip6_hdr *ip6;
 234
 235         if (ifp == NULL)
 236                 return;
 237
 238 #ifndef PULLDOWN_TEST
 239         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 240 #else
 241         if (m->m_len < sizeof(struct ip6_hdr)) {
 242                 m = m_pullup(m, sizeof(struct ip6_hdr));
 243                 if (m == NULL)
 244                         return;
 245         }
 246 #endif
 247
 248         ip6 = mtod(m, struct ip6_hdr *);
 249
 250         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 251                 return;
 252         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 253                 return;
 254
 255         icmp6_error(m, type, code, param);
 256 }
 257
 258 /*
 259  * Generate an error packet of type error in response to bad IP6 packet.
 260  */
 261 void
 262 icmp6_error(struct mbuf *m, int type, int code, int param)
 263 {
 264         struct ip6_hdr *oip6, *nip6;
 265         struct icmp6_hdr *icmp6;
 266         u_int preplen;
 267         int off;
 268         int nxt;
 269
 270         ICMP6STAT_INC(icp6s_error);
 271
 272         /* count per-type-code statistics */
 273         icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code);
 274
 275 #ifdef M_DECRYPTED      /*not openbsd*/
 276         if (m->m_flags & M_DECRYPTED) {
 277                 ICMP6STAT_INC(icp6s_canterror);
 278                 goto freeit;
 279         }
 280 #endif
 281
 282 #ifndef PULLDOWN_TEST
 283         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 284 #else
 285         if (m->m_len < sizeof(struct ip6_hdr)) {
 286                 m = m_pullup(m, sizeof(struct ip6_hdr));
 287                 if (m == NULL)
 288                         return;
 289         }
 290 #endif
 291         oip6 = mtod(m, struct ip6_hdr *);
 292
 293         /*
 294          * If the destination address of the erroneous packet is a multicast
 295          * address, or the packet was sent using link-layer multicast,
 296          * we should basically suppress sending an error (RFC 2463, Section
 297          * 2.4).
 298          * We have two exceptions (the item e.2 in that section):
 299          * - the Pakcet Too Big message can be sent for path MTU discovery.
 300          * - the Parameter Problem Message that can be allowed an icmp6 error
 301          *   in the option type field.  This check has been done in
 302          *   ip6_unknown_opt(), so we can just check the type and code.
 303          */
 304         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 305              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 306             (type != ICMP6_PACKET_TOO_BIG &&
 307              (type != ICMP6_PARAM_PROB ||
 308               code != ICMP6_PARAMPROB_OPTION)))
 309                 goto freeit;
 310
 311         /*
 312          * RFC 2463, 2.4 (e.5): source address check.
 313          * XXX: the case of anycast source?
 314          */
 315         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 316             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 317                 goto freeit;
 318
 319         /*
 320          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 321          * don't do it.
 322          */
 323         nxt = -1;
 324         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 325         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 326                 struct icmp6_hdr *icp;
 327
 328 #ifndef PULLDOWN_TEST
 329                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 330                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 331 #else
 332                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 333                         sizeof(*icp));
 334                 if (icp == NULL) {
 335                         ICMP6STAT_INC(icp6s_tooshort);
 336                         return;
 337                 }
 338 #endif
 339                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 340                     icp->icmp6_type == ND_REDIRECT) {
 341                         /*
 342                          * ICMPv6 error
 343                          * Special case: for redirect (which is
 344                          * informational) we must not send icmp6 error.
 345                          */
 346                         ICMP6STAT_INC(icp6s_canterror);
 347                         goto freeit;
 348                 } else {
 349                         /* ICMPv6 informational - send the error */
 350                 }
 351         } else {
 352                 /* non-ICMPv6 - send the error */
 353         }
 354
 355         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 356
 357         /* Finally, do rate limitation check. */
 358         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 359                 ICMP6STAT_INC(icp6s_toofreq);
 360                 goto freeit;
 361         }
 362
 363         /*
 364          * OK, ICMP6 can be generated.
 365          */
 366
 367         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 368                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 369
 370         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 371         M_PREPEND(m, preplen, M_DONTWAIT);
 372         if (m && m->m_len < preplen)
 373                 m = m_pullup(m, preplen);
 374         if (m == NULL) {
 375                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 376                 return;
 377         }
 378
 379         nip6 = mtod(m, struct ip6_hdr *);
 380         nip6->ip6_src  = oip6->ip6_src;
 381         nip6->ip6_dst  = oip6->ip6_dst;
 382
 383         in6_clearscope(&oip6->ip6_src);
 384         in6_clearscope(&oip6->ip6_dst);
 385
 386         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 387         icmp6->icmp6_type = type;
 388         icmp6->icmp6_code = code;
 389         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 390
 391         /*
 392          * icmp6_reflect() is designed to be in the input path.
 393          * icmp6_error() can be called from both input and output path,
 394          * and if we are in output path rcvif could contain bogus value.
 395          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 396          * information in ip header (nip6).
 397          */
 398         m->m_pkthdr.rcvif = NULL;
 399
 400         ICMP6STAT_INC(icp6s_outhist[type]);
 401         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 402
 403         return;
 404
 405   freeit:
 406         /*
 407          * If we can't tell whether or not we can generate ICMP6, free it.
 408          */
 409         m_freem(m);
 410 }
 411
 412 /*
 413  * Process a received ICMP6 message.
 414  */
 415 int
 416 icmp6_input(struct mbuf **mp, int *offp, int proto)
 417 {
 418         struct mbuf *m = *mp, *n;
 419         struct ifnet *ifp;
 420         struct ip6_hdr *ip6, *nip6;
 421         struct icmp6_hdr *icmp6, *nicmp6;
 422         int off = *offp;
 423         int icmp6len = m->m_pkthdr.len - *offp;
 424         int code, sum, noff;
 425         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 426
 427         ifp = m->m_pkthdr.rcvif;
 428
 429 #ifndef PULLDOWN_TEST
 430         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 431         /* m might change if M_LOOP.  So, call mtod after this */
 432 #endif
 433
 434         /*
 435          * Locate icmp6 structure in mbuf, and check
 436          * that not corrupted and of at least minimum length
 437          */
 438
 439         ip6 = mtod(m, struct ip6_hdr *);
 440         if (icmp6len < sizeof(struct icmp6_hdr)) {
 441                 ICMP6STAT_INC(icp6s_tooshort);
 442                 goto freeit;
 443         }
 444
 445         /*
 446          * Check multicast group membership.
 447          * Note: SSM filters are not applied for ICMPv6 traffic.
 448          */
 449         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 450                 struct in6_multi        *inm;
 451
 452                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 453                 if (inm == NULL) {
 454                         IP6STAT_INC(ip6s_notmember);
 455                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 456                         goto freeit;
 457                 }
 458         }
 459
 460         /*
 461          * calculate the checksum
 462          */
 463 #ifndef PULLDOWN_TEST
 464         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 465 #else
 466         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 467         if (icmp6 == NULL) {
 468                 ICMP6STAT_INC(icp6s_tooshort);
 469                 return IPPROTO_DONE;
 470         }
 471 #endif
 472         code = icmp6->icmp6_code;
 473
 474         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 475                 nd6log((LOG_ERR,
 476                     "ICMP6 checksum error(%d|%x) %s\n",
 477                     icmp6->icmp6_type, sum,
 478                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 479                 ICMP6STAT_INC(icp6s_checksum);
 480                 goto freeit;
 481         }
 482
 483         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 484                 /*
 485                  * Deliver very specific ICMP6 type only.
 486                  * This is important to deliver TOOBIG.  Otherwise PMTUD
 487                  * will not work.
 488                  */
 489                 switch (icmp6->icmp6_type) {
 490                 case ICMP6_DST_UNREACH:
 491                 case ICMP6_PACKET_TOO_BIG:
 492                 case ICMP6_TIME_EXCEEDED:
 493                         break;
 494                 default:
 495                         goto freeit;
 496                 }
 497         }
 498
 499         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 500         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 501         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 502                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 503
 504         switch (icmp6->icmp6_type) {
 505         case ICMP6_DST_UNREACH:
 506                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 507                 switch (code) {
 508                 case ICMP6_DST_UNREACH_NOROUTE:
 509                         code = PRC_UNREACH_NET;
 510                         break;
 511                 case ICMP6_DST_UNREACH_ADMIN:
 512                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 513                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 514                         break;
 515                 case ICMP6_DST_UNREACH_ADDR:
 516                         code = PRC_HOSTDEAD;
 517                         break;
 518                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 519                         /* I mean "source address was incorrect." */
 520                         code = PRC_PARAMPROB;
 521                         break;
 522                 case ICMP6_DST_UNREACH_NOPORT:
 523                         code = PRC_UNREACH_PORT;
 524                         break;
 525                 default:
 526                         goto badcode;
 527                 }
 528                 goto deliver;
 529                 break;
 530
 531         case ICMP6_PACKET_TOO_BIG:
 532                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 533
 534                 /* validation is made in icmp6_mtudisc_update */
 535
 536                 code = PRC_MSGSIZE;
 537
 538                 /*
 539                  * Updating the path MTU will be done after examining
 540                  * intermediate extension headers.
 541                  */
 542                 goto deliver;
 543                 break;
 544
 545         case ICMP6_TIME_EXCEEDED:
 546                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 547                 switch (code) {
 548                 case ICMP6_TIME_EXCEED_TRANSIT:
 549                         code = PRC_TIMXCEED_INTRANS;
 550                         break;
 551                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 552                         code = PRC_TIMXCEED_REASS;
 553                         break;
 554                 default:
 555                         goto badcode;
 556                 }
 557                 goto deliver;
 558                 break;
 559
 560         case ICMP6_PARAM_PROB:
 561                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 562                 switch (code) {
 563                 case ICMP6_PARAMPROB_NEXTHEADER:
 564                         code = PRC_UNREACH_PROTOCOL;
 565                         break;
 566                 case ICMP6_PARAMPROB_HEADER:
 567                 case ICMP6_PARAMPROB_OPTION:
 568                         code = PRC_PARAMPROB;
 569                         break;
 570                 default:
 571                         goto badcode;
 572                 }
 573                 goto deliver;
 574                 break;
 575
 576         case ICMP6_ECHO_REQUEST:
 577                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 578                 if (code != 0)
 579                         goto badcode;
 580                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 581                         /* Give up remote */
 582                         break;
 583                 }
 584                 if ((n->m_flags & M_EXT) != 0
 585                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 586                         struct mbuf *n0 = n;
 587                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 588                         int n0len;
 589
 590                         MGETHDR(n, M_DONTWAIT, n0->m_type);
 591                         n0len = n0->m_pkthdr.len;       /* save for use below */
 592                         if (n)
 593                                 M_MOVE_PKTHDR(n, n0);
 594                         if (n && maxlen >= MHLEN) {
 595                                 MCLGET(n, M_DONTWAIT);
 596                                 if ((n->m_flags & M_EXT) == 0) {
 597                                         m_free(n);
 598                                         n = NULL;
 599                                 }
 600                         }
 601                         if (n == NULL) {
 602                                 /* Give up remote */
 603                                 m_freem(n0);
 604                                 break;
 605                         }
 606                         /*
 607                          * Copy IPv6 and ICMPv6 only.
 608                          */
 609                         nip6 = mtod(n, struct ip6_hdr *);
 610                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 611                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 612                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 613                         noff = sizeof(struct ip6_hdr);
 614                         /* new mbuf contains only ipv6+icmpv6 headers */
 615                         n->m_len = noff + sizeof(struct icmp6_hdr);
 616                         /*
 617                          * Adjust mbuf.  ip6_plen will be adjusted in
 618                          * ip6_output().
 619                          */
 620                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 621                         /* recalculate complete packet size */
 622                         n->m_pkthdr.len = n0len + (noff - off);
 623                         n->m_next = n0;
 624                 } else {
 625                         nip6 = mtod(n, struct ip6_hdr *);
 626                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 627                             sizeof(*nicmp6));
 628                         noff = off;
 629                 }
 630                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 631                 nicmp6->icmp6_code = 0;
 632                 if (n) {
 633                         ICMP6STAT_INC(icp6s_reflect);
 634                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 635                         icmp6_reflect(n, noff);
 636                 }
 637                 break;
 638
 639         case ICMP6_ECHO_REPLY:
 640                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 641                 if (code != 0)
 642                         goto badcode;
 643                 break;
 644
 645         case MLD_LISTENER_QUERY:
 646         case MLD_LISTENER_REPORT:
 647         case MLD_LISTENER_DONE:
 648         case MLDV2_LISTENER_REPORT:
 649                 /*
 650                  * Drop MLD traffic which is not link-local, has a hop limit
 651                  * of greater than 1 hop, or which does not have the
 652                  * IPv6 HBH Router Alert option.
 653                  * As IPv6 HBH options are stripped in ip6_input() we must
 654                  * check an mbuf header flag.
 655                  * XXX Should we also sanity check that these messages
 656                  * were directed to a link-local multicast prefix?
 657                  */
 658                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 659                         goto freeit;
 660                 if (mld_input(m, off, icmp6len) != 0)
 661                         return (IPPROTO_DONE);
 662                 /* m stays. */
 663                 break;
 664
 665         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 666             {
 667                 enum { WRU, FQDN } mode;
 668
 669                 if (!V_icmp6_nodeinfo)
 670                         break;
 671
 672                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 673                         mode = WRU;
 674                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 675                         mode = FQDN;
 676                 else
 677                         goto badlen;
 678
 679                 if (mode == FQDN) {
 680 #ifndef PULLDOWN_TEST
 681                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 682                             IPPROTO_DONE);
 683 #endif
 684                         n = m_copy(m, 0, M_COPYALL);
 685                         if (n)
 686                                 n = ni6_input(n, off);
 687                         /* XXX meaningless if n == NULL */
 688                         noff = sizeof(struct ip6_hdr);
 689                 } else {
 690                         struct prison *pr;
 691                         u_char *p;
 692                         int maxlen, maxhlen, hlen;
 693
 694                         /*
 695                          * XXX: this combination of flags is pointless,
 696                          * but should we keep this for compatibility?
 697                          */
 698                         if ((V_icmp6_nodeinfo & 5) != 5)
 699                                 break;
 700
 701                         if (code != 0)
 702                                 goto badcode;
 703                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 704                         if (maxlen >= MCLBYTES) {
 705                                 /* Give up remote */
 706                                 break;
 707                         }
 708                         MGETHDR(n, M_DONTWAIT, m->m_type);
 709                         if (n && maxlen > MHLEN) {
 710                                 MCLGET(n, M_DONTWAIT);
 711                                 if ((n->m_flags & M_EXT) == 0) {
 712                                         m_free(n);
 713                                         n = NULL;
 714                                 }
 715                         }
 716                         if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
 717                                 /*
 718                                  * Previous code did a blind M_COPY_PKTHDR
 719                                  * and said "just for rcvif".  If true, then
 720                                  * we could tolerate the dup failing (due to
 721                                  * the deep copy of the tag chain).  For now
 722                                  * be conservative and just fail.
 723                                  */
 724                                 m_free(n);
 725                                 n = NULL;
 726                         }
 727                         if (n == NULL) {
 728                                 /* Give up remote */
 729                                 break;
 730                         }
 731                         n->m_pkthdr.rcvif = NULL;
 732                         n->m_len = 0;
 733                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 734                         pr = curthread->td_ucred->cr_prison;
 735                         mtx_lock(&pr->pr_mtx);
 736                         hlen = strlen(pr->pr_hostname);
 737                         if (maxhlen > hlen)
 738                                 maxhlen = hlen;
 739                         /*
 740                          * Copy IPv6 and ICMPv6 only.
 741                          */
 742                         nip6 = mtod(n, struct ip6_hdr *);
 743                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 744                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 745                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 746                         p = (u_char *)(nicmp6 + 1);
 747                         bzero(p, 4);
 748                         /* meaningless TTL */
 749                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 750                         mtx_unlock(&pr->pr_mtx);
 751                         noff = sizeof(struct ip6_hdr);
 752                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 753                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 754                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 755                         nicmp6->icmp6_code = 0;
 756                 }
 757                 if (n) {
 758                         ICMP6STAT_INC(icp6s_reflect);
 759                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 760                         icmp6_reflect(n, noff);
 761                 }
 762                 break;
 763             }
 764
 765         case ICMP6_WRUREPLY:
 766                 if (code != 0)
 767                         goto badcode;
 768                 break;
 769
 770         case ND_ROUTER_SOLICIT:
 771                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 772                 if (code != 0)
 773                         goto badcode;
 774                 if (icmp6len < sizeof(struct nd_router_solicit))
 775                         goto badlen;
 776                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 777                         /* give up local */
 778                         nd6_rs_input(m, off, icmp6len);
 779                         m = NULL;
 780                         goto freeit;
 781                 }
 782                 nd6_rs_input(n, off, icmp6len);
 783                 /* m stays. */
 784                 break;
 785
 786         case ND_ROUTER_ADVERT:
 787                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 788                 if (code != 0)
 789                         goto badcode;
 790                 if (icmp6len < sizeof(struct nd_router_advert))
 791                         goto badlen;
 792                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 793                         /* give up local */
 794                         nd6_ra_input(m, off, icmp6len);
 795                         m = NULL;
 796                         goto freeit;
 797                 }
 798                 nd6_ra_input(n, off, icmp6len);
 799                 /* m stays. */
 800                 break;
 801
 802         case ND_NEIGHBOR_SOLICIT:
 803                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 804                 if (code != 0)
 805                         goto badcode;
 806                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 807                         goto badlen;
 808                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 809                         /* give up local */
 810                         nd6_ns_input(m, off, icmp6len);
 811                         m = NULL;
 812                         goto freeit;
 813                 }
 814                 nd6_ns_input(n, off, icmp6len);
 815                 /* m stays. */
 816                 break;
 817
 818         case ND_NEIGHBOR_ADVERT:
 819                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 820                 if (code != 0)
 821                         goto badcode;
 822                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 823                         goto badlen;
 824                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 825                         /* give up local */
 826                         nd6_na_input(m, off, icmp6len);
 827                         m = NULL;
 828                         goto freeit;
 829                 }
 830                 nd6_na_input(n, off, icmp6len);
 831                 /* m stays. */
 832                 break;
 833
 834         case ND_REDIRECT:
 835                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 836                 if (code != 0)
 837                         goto badcode;
 838                 if (icmp6len < sizeof(struct nd_redirect))
 839                         goto badlen;
 840                 if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
 841                         /* give up local */
 842                         icmp6_redirect_input(m, off);
 843                         m = NULL;
 844                         goto freeit;
 845                 }
 846                 icmp6_redirect_input(n, off);
 847                 /* m stays. */
 848                 break;
 849
 850         case ICMP6_ROUTER_RENUMBERING:
 851                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 852                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 853                         goto badcode;
 854                 if (icmp6len < sizeof(struct icmp6_router_renum))
 855                         goto badlen;
 856                 break;
 857
 858         default:
 859                 nd6log((LOG_DEBUG,
 860                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 861                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 862                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 863                     ifp ? ifp->if_index : 0));
 864                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 865                         /* ICMPv6 error: MUST deliver it by spec... */
 866                         code = PRC_NCMDS;
 867                         /* deliver */
 868                 } else {
 869                         /* ICMPv6 informational: MUST not deliver */
 870                         break;
 871                 }
 872         deliver:
 873                 if (icmp6_notify_error(&m, off, icmp6len, code)) {
 874                         /* In this case, m should've been freed. */
 875                         return (IPPROTO_DONE);
 876                 }
 877                 break;
 878
 879         badcode:
 880                 ICMP6STAT_INC(icp6s_badcode);
 881                 break;
 882
 883         badlen:
 884                 ICMP6STAT_INC(icp6s_badlen);
 885                 break;
 886         }
 887
 888         /* deliver the packet to appropriate sockets */
 889         icmp6_rip6_input(&m, *offp);
 890
 891         return IPPROTO_DONE;
 892
 893  freeit:
 894         m_freem(m);
 895         return IPPROTO_DONE;
 896 }
 897
 898 static int
 899 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 900 {
 901         struct mbuf *m = *mp;
 902         struct icmp6_hdr *icmp6;
 903         struct ip6_hdr *eip6;
 904         u_int32_t notifymtu;
 905         struct sockaddr_in6 icmp6src, icmp6dst;
 906
 907         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 908                 ICMP6STAT_INC(icp6s_tooshort);
 909                 goto freeit;
 910         }
 911 #ifndef PULLDOWN_TEST
 912         IP6_EXTHDR_CHECK(m, off,
 913             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 914         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 915 #else
 916         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 917             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 918         if (icmp6 == NULL) {
 919                 ICMP6STAT_INC(icp6s_tooshort);
 920                 return (-1);
 921         }
 922 #endif
 923         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 924
 925         /* Detect the upper level protocol */
 926         {
 927                 void (*ctlfunc)(int, struct sockaddr *, void *);
 928                 u_int8_t nxt = eip6->ip6_nxt;
 929                 int eoff = off + sizeof(struct icmp6_hdr) +
 930                     sizeof(struct ip6_hdr);
 931                 struct ip6ctlparam ip6cp;
 932                 struct in6_addr *finaldst = NULL;
 933                 int icmp6type = icmp6->icmp6_type;
 934                 struct ip6_frag *fh;
 935                 struct ip6_rthdr *rth;
 936                 struct ip6_rthdr0 *rth0;
 937                 int rthlen;
 938
 939                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 940                         struct ip6_ext *eh;
 941
 942                         switch (nxt) {
 943                         case IPPROTO_HOPOPTS:
 944                         case IPPROTO_DSTOPTS:
 945                         case IPPROTO_AH:
 946 #ifndef PULLDOWN_TEST
 947                                 IP6_EXTHDR_CHECK(m, 0,
 948                                     eoff + sizeof(struct ip6_ext), -1);
 949                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 950 #else
 951                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 952                                     eoff, sizeof(*eh));
 953                                 if (eh == NULL) {
 954                                         ICMP6STAT_INC(icp6s_tooshort);
 955                                         return (-1);
 956                                 }
 957 #endif
 958
 959                                 if (nxt == IPPROTO_AH)
 960                                         eoff += (eh->ip6e_len + 2) << 2;
 961                                 else
 962                                         eoff += (eh->ip6e_len + 1) << 3;
 963                                 nxt = eh->ip6e_nxt;
 964                                 break;
 965                         case IPPROTO_ROUTING:
 966                                 /*
 967                                  * When the erroneous packet contains a
 968                                  * routing header, we should examine the
 969                                  * header to determine the final destination.
 970                                  * Otherwise, we can't properly update
 971                                  * information that depends on the final
 972                                  * destination (e.g. path MTU).
 973                                  */
 974 #ifndef PULLDOWN_TEST
 975                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 976                                 rth = (struct ip6_rthdr *)
 977                                     (mtod(m, caddr_t) + eoff);
 978 #else
 979                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 980                                     eoff, sizeof(*rth));
 981                                 if (rth == NULL) {
 982                                         ICMP6STAT_INC(icp6s_tooshort);
 983                                         return (-1);
 984                                 }
 985 #endif
 986                                 rthlen = (rth->ip6r_len + 1) << 3;
 987                                 /*
 988                                  * XXX: currently there is no
 989                                  * officially defined type other
 990                                  * than type-0.
 991                                  * Note that if the segment left field
 992                                  * is 0, all intermediate hops must
 993                                  * have been passed.
 994                                  */
 995                                 if (rth->ip6r_segleft &&
 996                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 997                                         int hops;
 998
 999 #ifndef PULLDOWN_TEST
1000                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1001                                         rth0 = (struct ip6_rthdr0 *)
1002                                             (mtod(m, caddr_t) + eoff);
1003 #else
1004                                         IP6_EXTHDR_GET(rth0,
1005                                             struct ip6_rthdr0 *, m,
1006                                             eoff, rthlen);
1007                                         if (rth0 == NULL) {
1008                                                 ICMP6STAT_INC(icp6s_tooshort);
1009                                                 return (-1);
1010                                         }
1011 #endif
1012                                         /* just ignore a bogus header */
1013                                         if ((rth0->ip6r0_len % 2) == 0 &&
1014                                             (hops = rth0->ip6r0_len/2))
1015                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1016                                 }
1017                                 eoff += rthlen;
1018                                 nxt = rth->ip6r_nxt;
1019                                 break;
1020                         case IPPROTO_FRAGMENT:
1021 #ifndef PULLDOWN_TEST
1022                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1023                                     sizeof(struct ip6_frag), -1);
1024                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1025                                     eoff);
1026 #else
1027                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1028                                     eoff, sizeof(*fh));
1029                                 if (fh == NULL) {
1030                                         ICMP6STAT_INC(icp6s_tooshort);
1031                                         return (-1);
1032                                 }
1033 #endif
1034                                 /*
1035                                  * Data after a fragment header is meaningless
1036                                  * unless it is the first fragment, but
1037                                  * we'll go to the notify label for path MTU
1038                                  * discovery.
1039                                  */
1040                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1041                                         goto notify;
1042
1043                                 eoff += sizeof(struct ip6_frag);
1044                                 nxt = fh->ip6f_nxt;
1045                                 break;
1046                         default:
1047                                 /*
1048                                  * This case includes ESP and the No Next
1049                                  * Header.  In such cases going to the notify
1050                                  * label does not have any meaning
1051                                  * (i.e. ctlfunc will be NULL), but we go
1052                                  * anyway since we might have to update
1053                                  * path MTU information.
1054                                  */
1055                                 goto notify;
1056                         }
1057                 }
1058           notify:
1059 #ifndef PULLDOWN_TEST
1060                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1061 #else
1062                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1063                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1064                 if (icmp6 == NULL) {
1065                         ICMP6STAT_INC(icp6s_tooshort);
1066                         return (-1);
1067                 }
1068 #endif
1069
1070                 /*
1071                  * retrieve parameters from the inner IPv6 header, and convert
1072                  * them into sockaddr structures.
1073                  * XXX: there is no guarantee that the source or destination
1074                  * addresses of the inner packet are in the same scope as
1075                  * the addresses of the icmp packet.  But there is no other
1076                  * way to determine the zone.
1077                  */
1078                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1079
1080                 bzero(&icmp6dst, sizeof(icmp6dst));
1081                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1082                 icmp6dst.sin6_family = AF_INET6;
1083                 if (finaldst == NULL)
1084                         icmp6dst.sin6_addr = eip6->ip6_dst;
1085                 else
1086                         icmp6dst.sin6_addr = *finaldst;
1087                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1088                         goto freeit;
1089                 bzero(&icmp6src, sizeof(icmp6src));
1090                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1091                 icmp6src.sin6_family = AF_INET6;
1092                 icmp6src.sin6_addr = eip6->ip6_src;
1093                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1094                         goto freeit;
1095                 icmp6src.sin6_flowinfo =
1096                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1097
1098                 if (finaldst == NULL)
1099                         finaldst = &eip6->ip6_dst;
1100                 ip6cp.ip6c_m = m;
1101                 ip6cp.ip6c_icmp6 = icmp6;
1102                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1103                 ip6cp.ip6c_off = eoff;
1104                 ip6cp.ip6c_finaldst = finaldst;
1105                 ip6cp.ip6c_src = &icmp6src;
1106                 ip6cp.ip6c_nxt = nxt;
1107
1108                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1109                         notifymtu = ntohl(icmp6->icmp6_mtu);
1110                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1111                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1112                 }
1113
1114                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1115                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1116                 if (ctlfunc) {
1117                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1118                             &ip6cp);
1119                 }
1120         }
1121         *mp = m;
1122         return (0);
1123
1124   freeit:
1125         m_freem(m);
1126         return (-1);
1127 }
1128
1129 void
1130 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1131 {
1132         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1133         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1134         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1135         u_int mtu = ntohl(icmp6->icmp6_mtu);
1136         struct in_conninfo inc;
1137
1138 #if 0
1139         /*
1140          * RFC2460 section 5, last paragraph.
1141          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1142          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1143          * due to packet translator in the middle.
1144          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1145          * special handling.
1146          */
1147         if (mtu < IPV6_MMTU)
1148                 return;
1149 #endif
1150
1151         /*
1152          * we reject ICMPv6 too big with abnormally small value.
1153          * XXX what is the good definition of "abnormally small"?
1154          */
1155         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1156                 return;
1157
1158         if (!validated)
1159                 return;
1160
1161         /*
1162          * In case the suggested mtu is less than IPV6_MMTU, we
1163          * only need to remember that it was for above mentioned
1164          * "alwaysfrag" case.
1165          * Try to be as close to the spec as possible.
1166          */
1167         if (mtu < IPV6_MMTU)
1168                 mtu = IPV6_MMTU - 8;
1169
1170         bzero(&inc, sizeof(inc));
1171         inc.inc_flags |= INC_ISIPV6;
1172         inc.inc6_faddr = *dst;
1173         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1174                 return;
1175
1176         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1177                 tcp_hc_updatemtu(&inc, mtu);
1178                 ICMP6STAT_INC(icp6s_pmtuchg);
1179         }
1180 }
1181
1182 /*
1183  * Process a Node Information Query packet, based on
1184  * draft-ietf-ipngwg-icmp-name-lookups-07.
1185  *
1186  * Spec incompatibilities:
1187  * - IPv6 Subject address handling
1188  * - IPv4 Subject address handling support missing
1189  * - Proxy reply (answer even if it's not for me)
1190  * - joins NI group address at in6_ifattach() time only, does not cope
1191  *   with hostname changes by sethostname(3)
1192  */
1193 static struct mbuf *
1194 ni6_input(struct mbuf *m, int off)
1195 {
1196         struct icmp6_nodeinfo *ni6, *nni6;
1197         struct mbuf *n = NULL;
1198         struct prison *pr;
1199         u_int16_t qtype;
1200         int subjlen;
1201         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1202         struct ni_reply_fqdn *fqdn;
1203         int addrs;              /* for NI_QTYPE_NODEADDR */
1204         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1205         struct in6_addr in6_subj; /* subject address */
1206         struct ip6_hdr *ip6;
1207         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1208         char *subj = NULL;
1209         struct in6_ifaddr *ia6 = NULL;
1210
1211         ip6 = mtod(m, struct ip6_hdr *);
1212 #ifndef PULLDOWN_TEST
1213         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1214 #else
1215         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1216         if (ni6 == NULL) {
1217                 /* m is already reclaimed */
1218                 return (NULL);
1219         }
1220 #endif
1221
1222         /*
1223          * Validate IPv6 source address.
1224          * The default configuration MUST be to refuse answering queries from
1225          * global-scope addresses according to RFC4602.
1226          * Notes:
1227          *  - it's not very clear what "refuse" means; this implementation
1228          *    simply drops it.
1229          *  - it's not very easy to identify global-scope (unicast) addresses
1230          *    since there are many prefixes for them.  It should be safer
1231          *    and in practice sufficient to check "all" but loopback and
1232          *    link-local (note that site-local unicast was deprecated and
1233          *    ULA is defined as global scope-wise)
1234          */
1235         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1236             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1237             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1238                 goto bad;
1239
1240         /*
1241          * Validate IPv6 destination address.
1242          *
1243          * The Responder must discard the Query without further processing
1244          * unless it is one of the Responder's unicast or anycast addresses, or
1245          * a link-local scope multicast address which the Responder has joined.
1246          * [RFC4602, Section 5.]
1247          */
1248         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1249                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1250                         goto bad;
1251                 /* else it's a link-local multicast, fine */
1252         } else {                /* unicast or anycast */
1253                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1254                         goto bad; /* XXX impossible */
1255
1256                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1257                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1258                         ifa_free(&ia6->ia_ifa);
1259                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1260                                 "a temporary address in %s:%d",
1261                                __FILE__, __LINE__));
1262                         goto bad;
1263                 }
1264                 ifa_free(&ia6->ia_ifa);
1265         }
1266
1267         /* validate query Subject field. */
1268         qtype = ntohs(ni6->ni_qtype);
1269         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1270         switch (qtype) {
1271         case NI_QTYPE_NOOP:
1272         case NI_QTYPE_SUPTYPES:
1273                 /* 07 draft */
1274                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1275                         break;
1276                 /* FALLTHROUGH */
1277         case NI_QTYPE_FQDN:
1278         case NI_QTYPE_NODEADDR:
1279         case NI_QTYPE_IPV4ADDR:
1280                 switch (ni6->ni_code) {
1281                 case ICMP6_NI_SUBJ_IPV6:
1282 #if ICMP6_NI_SUBJ_IPV6 != 0
1283                 case 0:
1284 #endif
1285                         /*
1286                          * backward compatibility - try to accept 03 draft
1287                          * format, where no Subject is present.
1288                          */
1289                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1290                             subjlen == 0) {
1291                                 oldfqdn++;
1292                                 break;
1293                         }
1294 #if ICMP6_NI_SUBJ_IPV6 != 0
1295                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1296                                 goto bad;
1297 #endif
1298
1299                         if (subjlen != sizeof(struct in6_addr))
1300                                 goto bad;
1301
1302                         /*
1303                          * Validate Subject address.
1304                          *
1305                          * Not sure what exactly "address belongs to the node"
1306                          * means in the spec, is it just unicast, or what?
1307                          *
1308                          * At this moment we consider Subject address as
1309                          * "belong to the node" if the Subject address equals
1310                          * to the IPv6 destination address; validation for
1311                          * IPv6 destination address should have done enough
1312                          * check for us.
1313                          *
1314                          * We do not do proxy at this moment.
1315                          */
1316                         /* m_pulldown instead of copy? */
1317                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1318                             subjlen, (caddr_t)&in6_subj);
1319                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1320                                 goto bad;
1321
1322                         subj = (char *)&in6_subj;
1323                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1324                                 break;
1325
1326                         /*
1327                          * XXX if we are to allow other cases, we should really
1328                          * be careful about scope here.
1329                          * basically, we should disallow queries toward IPv6
1330                          * destination X with subject Y,
1331                          * if scope(X) > scope(Y).
1332                          * if we allow scope(X) > scope(Y), it will result in
1333                          * information leakage across scope boundary.
1334                          */
1335                         goto bad;
1336
1337                 case ICMP6_NI_SUBJ_FQDN:
1338                         /*
1339                          * Validate Subject name with gethostname(3).
1340                          *
1341                          * The behavior may need some debate, since:
1342                          * - we are not sure if the node has FQDN as
1343                          *   hostname (returned by gethostname(3)).
1344                          * - the code does wildcard match for truncated names.
1345                          *   however, we are not sure if we want to perform
1346                          *   wildcard match, if gethostname(3) side has
1347                          *   truncated hostname.
1348                          */
1349                         pr = curthread->td_ucred->cr_prison;
1350                         mtx_lock(&pr->pr_mtx);
1351                         n = ni6_nametodns(pr->pr_hostname,
1352                             strlen(pr->pr_hostname), 0);
1353                         mtx_unlock(&pr->pr_mtx);
1354                         if (!n || n->m_next || n->m_len == 0)
1355                                 goto bad;
1356                         IP6_EXTHDR_GET(subj, char *, m,
1357                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1358                         if (subj == NULL)
1359                                 goto bad;
1360                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1361                             n->m_len)) {
1362                                 goto bad;
1363                         }
1364                         m_freem(n);
1365                         n = NULL;
1366                         break;
1367
1368                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1369                 default:
1370                         goto bad;
1371                 }
1372                 break;
1373         }
1374
1375         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1376         switch (qtype) {
1377         case NI_QTYPE_FQDN:
1378                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1379                         goto bad;
1380                 break;
1381         case NI_QTYPE_NODEADDR:
1382         case NI_QTYPE_IPV4ADDR:
1383                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1384                         goto bad;
1385                 break;
1386         }
1387
1388         /* guess reply length */
1389         switch (qtype) {
1390         case NI_QTYPE_NOOP:
1391                 break;          /* no reply data */
1392         case NI_QTYPE_SUPTYPES:
1393                 replylen += sizeof(u_int32_t);
1394                 break;
1395         case NI_QTYPE_FQDN:
1396                 /* XXX will append an mbuf */
1397                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1398                 break;
1399         case NI_QTYPE_NODEADDR:
1400                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1401                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1402                     sizeof(u_int32_t))) > MCLBYTES)
1403                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1404                 break;
1405         case NI_QTYPE_IPV4ADDR:
1406                 /* unsupported - should respond with unknown Qtype? */
1407                 break;
1408         default:
1409                 /*
1410                  * XXX: We must return a reply with the ICMP6 code
1411                  * `unknown Qtype' in this case.  However we regard the case
1412                  * as an FQDN query for backward compatibility.
1413                  * Older versions set a random value to this field,
1414                  * so it rarely varies in the defined qtypes.
1415                  * But the mechanism is not reliable...
1416                  * maybe we should obsolete older versions.
1417                  */
1418                 qtype = NI_QTYPE_FQDN;
1419                 /* XXX will append an mbuf */
1420                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1421                 oldfqdn++;
1422                 break;
1423         }
1424
1425         /* allocate an mbuf to reply. */
1426         MGETHDR(n, M_DONTWAIT, m->m_type);
1427         if (n == NULL) {
1428                 m_freem(m);
1429                 return (NULL);
1430         }
1431         M_MOVE_PKTHDR(n, m); /* just for recvif */
1432         if (replylen > MHLEN) {
1433                 if (replylen > MCLBYTES) {
1434                         /*
1435                          * XXX: should we try to allocate more? But MCLBYTES
1436                          * is probably much larger than IPV6_MMTU...
1437                          */
1438                         goto bad;
1439                 }
1440                 MCLGET(n, M_DONTWAIT);
1441                 if ((n->m_flags & M_EXT) == 0) {
1442                         goto bad;
1443                 }
1444         }
1445         n->m_pkthdr.len = n->m_len = replylen;
1446
1447         /* copy mbuf header and IPv6 + Node Information base headers */
1448         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1449         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1450         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1451
1452         /* qtype dependent procedure */
1453         switch (qtype) {
1454         case NI_QTYPE_NOOP:
1455                 nni6->ni_code = ICMP6_NI_SUCCESS;
1456                 nni6->ni_flags = 0;
1457                 break;
1458         case NI_QTYPE_SUPTYPES:
1459         {
1460                 u_int32_t v;
1461                 nni6->ni_code = ICMP6_NI_SUCCESS;
1462                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1463                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1464                 v = (u_int32_t)htonl(0x0000000f);
1465                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1466                 break;
1467         }
1468         case NI_QTYPE_FQDN:
1469                 nni6->ni_code = ICMP6_NI_SUCCESS;
1470                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1471                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1472                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1473                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1474                 /*
1475                  * XXX do we really have FQDN in hostname?
1476                  */
1477                 pr = curthread->td_ucred->cr_prison;
1478                 mtx_lock(&pr->pr_mtx);
1479                 n->m_next = ni6_nametodns(pr->pr_hostname,
1480                     strlen(pr->pr_hostname), oldfqdn);
1481                 mtx_unlock(&pr->pr_mtx);
1482                 if (n->m_next == NULL)
1483                         goto bad;
1484                 /* XXX we assume that n->m_next is not a chain */
1485                 if (n->m_next->m_next != NULL)
1486                         goto bad;
1487                 n->m_pkthdr.len += n->m_next->m_len;
1488                 break;
1489         case NI_QTYPE_NODEADDR:
1490         {
1491                 int lenlim, copied;
1492
1493                 nni6->ni_code = ICMP6_NI_SUCCESS;
1494                 n->m_pkthdr.len = n->m_len =
1495                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1496                 lenlim = M_TRAILINGSPACE(n);
1497                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1498                 /* XXX: reset mbuf length */
1499                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1500                     sizeof(struct icmp6_nodeinfo) + copied;
1501                 break;
1502         }
1503         default:
1504                 break;          /* XXX impossible! */
1505         }
1506
1507         nni6->ni_type = ICMP6_NI_REPLY;
1508         m_freem(m);
1509         return (n);
1510
1511   bad:
1512         m_freem(m);
1513         if (n)
1514                 m_freem(n);
1515         return (NULL);
1516 }
1517
1518 /*
1519  * make a mbuf with DNS-encoded string.  no compression support.
1520  *
1521  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1522  * treated as truncated name (two \0 at the end).  this is a wild guess.
1523  *
1524  * old - return pascal string if non-zero
1525  */
1526 static struct mbuf *
1527 ni6_nametodns(const char *name, int namelen, int old)
1528 {
1529         struct mbuf *m;
1530         char *cp, *ep;
1531         const char *p, *q;
1532         int i, len, nterm;
1533
1534         if (old)
1535                 len = namelen + 1;
1536         else
1537                 len = MCLBYTES;
1538
1539         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1540         MGET(m, M_DONTWAIT, MT_DATA);
1541         if (m && len > MLEN) {
1542                 MCLGET(m, M_DONTWAIT);
1543                 if ((m->m_flags & M_EXT) == 0)
1544                         goto fail;
1545         }
1546         if (!m)
1547                 goto fail;
1548         m->m_next = NULL;
1549
1550         if (old) {
1551                 m->m_len = len;
1552                 *mtod(m, char *) = namelen;
1553                 bcopy(name, mtod(m, char *) + 1, namelen);
1554                 return m;
1555         } else {
1556                 m->m_len = 0;
1557                 cp = mtod(m, char *);
1558                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1559
1560                 /* if not certain about my name, return empty buffer */
1561                 if (namelen == 0)
1562                         return m;
1563
1564                 /*
1565                  * guess if it looks like shortened hostname, or FQDN.
1566                  * shortened hostname needs two trailing "\0".
1567                  */
1568                 i = 0;
1569                 for (p = name; p < name + namelen; p++) {
1570                         if (*p && *p == '.')
1571                                 i++;
1572                 }
1573                 if (i < 2)
1574                         nterm = 2;
1575                 else
1576                         nterm = 1;
1577
1578                 p = name;
1579                 while (cp < ep && p < name + namelen) {
1580                         i = 0;
1581                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1582                                 i++;
1583                         /* result does not fit into mbuf */
1584                         if (cp + i + 1 >= ep)
1585                                 goto fail;
1586                         /*
1587                          * DNS label length restriction, RFC1035 page 8.
1588                          * "i == 0" case is included here to avoid returning
1589                          * 0-length label on "foo..bar".
1590                          */
1591                         if (i <= 0 || i >= 64)
1592                                 goto fail;
1593                         *cp++ = i;
1594                         bcopy(p, cp, i);
1595                         cp += i;
1596                         p = q;
1597                         if (p < name + namelen && *p == '.')
1598                                 p++;
1599                 }
1600                 /* termination */
1601                 if (cp + nterm >= ep)
1602                         goto fail;
1603                 while (nterm-- > 0)
1604                         *cp++ = '\0';
1605                 m->m_len = cp - mtod(m, char *);
1606                 return m;
1607         }
1608
1609         panic("should not reach here");
1610         /* NOTREACHED */
1611
1612  fail:
1613         if (m)
1614                 m_freem(m);
1615         return NULL;
1616 }
1617
1618 /*
1619  * check if two DNS-encoded string matches.  takes care of truncated
1620  * form (with \0\0 at the end).  no compression support.
1621  * XXX upper/lowercase match (see RFC2065)
1622  */
1623 static int
1624 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1625 {
1626         const char *a0, *b0;
1627         int l;
1628
1629         /* simplest case - need validation? */
1630         if (alen == blen && bcmp(a, b, alen) == 0)
1631                 return 1;
1632
1633         a0 = a;
1634         b0 = b;
1635
1636         /* termination is mandatory */
1637         if (alen < 2 || blen < 2)
1638                 return 0;
1639         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1640                 return 0;
1641         alen--;
1642         blen--;
1643
1644         while (a - a0 < alen && b - b0 < blen) {
1645                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1646                         return 0;
1647
1648                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1649                         return 0;
1650                 /* we don't support compression yet */
1651                 if (a[0] >= 64 || b[0] >= 64)
1652                         return 0;
1653
1654                 /* truncated case */
1655                 if (a[0] == 0 && a - a0 == alen - 1)
1656                         return 1;
1657                 if (b[0] == 0 && b - b0 == blen - 1)
1658                         return 1;
1659                 if (a[0] == 0 || b[0] == 0)
1660                         return 0;
1661
1662                 if (a[0] != b[0])
1663                         return 0;
1664                 l = a[0];
1665                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1666                         return 0;
1667                 if (bcmp(a + 1, b + 1, l) != 0)
1668                         return 0;
1669
1670                 a += 1 + l;
1671                 b += 1 + l;
1672         }
1673
1674         if (a - a0 == alen && b - b0 == blen)
1675                 return 1;
1676         else
1677                 return 0;
1678 }
1679
1680 /*
1681  * calculate the number of addresses to be returned in the node info reply.
1682  */
1683 static int
1684 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1685     struct in6_addr *subj)
1686 {
1687         struct ifnet *ifp;
1688         struct in6_ifaddr *ifa6;
1689         struct ifaddr *ifa;
1690         int addrs = 0, addrsofif, iffound = 0;
1691         int niflags = ni6->ni_flags;
1692
1693         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1694                 switch (ni6->ni_code) {
1695                 case ICMP6_NI_SUBJ_IPV6:
1696                         if (subj == NULL) /* must be impossible... */
1697                                 return (0);
1698                         break;
1699                 default:
1700                         /*
1701                          * XXX: we only support IPv6 subject address for
1702                          * this Qtype.
1703                          */
1704                         return (0);
1705                 }
1706         }
1707
1708         IFNET_RLOCK_NOSLEEP();
1709         for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1710                 addrsofif = 0;
1711                 IF_ADDR_LOCK(ifp);
1712                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1713                         if (ifa->ifa_addr->sa_family != AF_INET6)
1714                                 continue;
1715                         ifa6 = (struct in6_ifaddr *)ifa;
1716
1717                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1718                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1719                                 iffound = 1;
1720
1721                         /*
1722                          * IPv4-mapped addresses can only be returned by a
1723                          * Node Information proxy, since they represent
1724                          * addresses of IPv4-only nodes, which perforce do
1725                          * not implement this protocol.
1726                          * [icmp-name-lookups-07, Section 5.4]
1727                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1728                          * this function at this moment.
1729                          */
1730
1731                         /* What do we have to do about ::1? */
1732                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1733                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1734                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1735                                         continue;
1736                                 break;
1737                         case IPV6_ADDR_SCOPE_SITELOCAL:
1738                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1739                                         continue;
1740                                 break;
1741                         case IPV6_ADDR_SCOPE_GLOBAL:
1742                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1743                                         continue;
1744                                 break;
1745                         default:
1746                                 continue;
1747                         }
1748
1749                         /*
1750                          * check if anycast is okay.
1751                          * XXX: just experimental.  not in the spec.
1752                          */
1753                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1754                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1755                                 continue; /* we need only unicast addresses */
1756                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1757                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1758                                 continue;
1759                         }
1760                         addrsofif++; /* count the address */
1761                 }
1762                 IF_ADDR_UNLOCK(ifp);
1763                 if (iffound) {
1764                         *ifpp = ifp;
1765                         IFNET_RUNLOCK_NOSLEEP();
1766                         return (addrsofif);
1767                 }
1768
1769                 addrs += addrsofif;
1770         }
1771         IFNET_RUNLOCK_NOSLEEP();
1772
1773         return (addrs);
1774 }
1775
1776 static int
1777 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1778     struct ifnet *ifp0, int resid)
1779 {
1780         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1781         struct in6_ifaddr *ifa6;
1782         struct ifaddr *ifa;
1783         struct ifnet *ifp_dep = NULL;
1784         int copied = 0, allow_deprecated = 0;
1785         u_char *cp = (u_char *)(nni6 + 1);
1786         int niflags = ni6->ni_flags;
1787         u_int32_t ltime;
1788
1789         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1790                 return (0);     /* needless to copy */
1791
1792         IFNET_RLOCK_NOSLEEP();
1793   again:
1794
1795         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1796                 IF_ADDR_LOCK(ifp);
1797                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1798                         if (ifa->ifa_addr->sa_family != AF_INET6)
1799                                 continue;
1800                         ifa6 = (struct in6_ifaddr *)ifa;
1801
1802                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1803                             allow_deprecated == 0) {
1804                                 /*
1805                                  * prefererred address should be put before
1806                                  * deprecated addresses.
1807                                  */
1808
1809                                 /* record the interface for later search */
1810                                 if (ifp_dep == NULL)
1811                                         ifp_dep = ifp;
1812
1813                                 continue;
1814                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1815                             allow_deprecated != 0)
1816                                 continue; /* we now collect deprecated addrs */
1817
1818                         /* What do we have to do about ::1? */
1819                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1820                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1821                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1822                                         continue;
1823                                 break;
1824                         case IPV6_ADDR_SCOPE_SITELOCAL:
1825                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1826                                         continue;
1827                                 break;
1828                         case IPV6_ADDR_SCOPE_GLOBAL:
1829                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1830                                         continue;
1831                                 break;
1832                         default:
1833                                 continue;
1834                         }
1835
1836                         /*
1837                          * check if anycast is okay.
1838                          * XXX: just experimental.  not in the spec.
1839                          */
1840                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1841                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1842                                 continue;
1843                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1844                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1845                                 continue;
1846                         }
1847
1848                         /* now we can copy the address */
1849                         if (resid < sizeof(struct in6_addr) +
1850                             sizeof(u_int32_t)) {
1851                                 IF_ADDR_UNLOCK(ifp);
1852                                 /*
1853                                  * We give up much more copy.
1854                                  * Set the truncate flag and return.
1855                                  */
1856                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1857                                 IFNET_RUNLOCK_NOSLEEP();
1858                                 return (copied);
1859                         }
1860
1861                         /*
1862                          * Set the TTL of the address.
1863                          * The TTL value should be one of the following
1864                          * according to the specification:
1865                          *
1866                          * 1. The remaining lifetime of a DHCP lease on the
1867                          *    address, or
1868                          * 2. The remaining Valid Lifetime of a prefix from
1869                          *    which the address was derived through Stateless
1870                          *    Autoconfiguration.
1871                          *
1872                          * Note that we currently do not support stateful
1873                          * address configuration by DHCPv6, so the former
1874                          * case can't happen.
1875                          */
1876                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1877                                 ltime = ND6_INFINITE_LIFETIME;
1878                         else {
1879                                 if (ifa6->ia6_lifetime.ia6t_expire >
1880                                     time_second)
1881                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1882                                 else
1883                                         ltime = 0;
1884                         }
1885
1886                         bcopy(&ltime, cp, sizeof(u_int32_t));
1887                         cp += sizeof(u_int32_t);
1888
1889                         /* copy the address itself */
1890                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1891                             sizeof(struct in6_addr));
1892                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1893                         cp += sizeof(struct in6_addr);
1894
1895                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1896                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1897                 }
1898                 IF_ADDR_UNLOCK(ifp);
1899                 if (ifp0)       /* we need search only on the specified IF */
1900                         break;
1901         }
1902
1903         if (allow_deprecated == 0 && ifp_dep != NULL) {
1904                 ifp = ifp_dep;
1905                 allow_deprecated = 1;
1906
1907                 goto again;
1908         }
1909
1910         IFNET_RUNLOCK_NOSLEEP();
1911
1912         return (copied);
1913 }
1914
1915 /*
1916  * XXX almost dup'ed code with rip6_input.
1917  */
1918 static int
1919 icmp6_rip6_input(struct mbuf **mp, int off)
1920 {
1921         struct mbuf *m = *mp;
1922         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1923         struct inpcb *in6p;
1924         struct inpcb *last = NULL;
1925         struct sockaddr_in6 fromsa;
1926         struct icmp6_hdr *icmp6;
1927         struct mbuf *opts = NULL;
1928
1929 #ifndef PULLDOWN_TEST
1930         /* this is assumed to be safe. */
1931         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1932 #else
1933         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1934         if (icmp6 == NULL) {
1935                 /* m is already reclaimed */
1936                 return (IPPROTO_DONE);
1937         }
1938 #endif
1939
1940         /*
1941          * XXX: the address may have embedded scope zone ID, which should be
1942          * hidden from applications.
1943          */
1944         bzero(&fromsa, sizeof(fromsa));
1945         fromsa.sin6_family = AF_INET6;
1946         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1947         fromsa.sin6_addr = ip6->ip6_src;
1948         if (sa6_recoverscope(&fromsa)) {
1949                 m_freem(m);
1950                 return (IPPROTO_DONE);
1951         }
1952
1953         INP_INFO_RLOCK(&V_ripcbinfo);
1954         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1955                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1956                         continue;
1957                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1958                         continue;
1959                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1960                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1961                         continue;
1962                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1963                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1964                         continue;
1965                 INP_RLOCK(in6p);
1966                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1967                     in6p->in6p_icmp6filt)) {
1968                         INP_RUNLOCK(in6p);
1969                         continue;
1970                 }
1971                 if (last != NULL) {
1972                         struct  mbuf *n = NULL;
1973
1974                         /*
1975                          * Recent network drivers tend to allocate a single
1976                          * mbuf cluster, rather than to make a couple of
1977                          * mbufs without clusters.  Also, since the IPv6 code
1978                          * path tries to avoid m_pullup(), it is highly
1979                          * probable that we still have an mbuf cluster here
1980                          * even though the necessary length can be stored in an
1981                          * mbuf's internal buffer.
1982                          * Meanwhile, the default size of the receive socket
1983                          * buffer for raw sockets is not so large.  This means
1984                          * the possibility of packet loss is relatively higher
1985                          * than before.  To avoid this scenario, we copy the
1986                          * received data to a separate mbuf that does not use
1987                          * a cluster, if possible.
1988                          * XXX: it is better to copy the data after stripping
1989                          * intermediate headers.
1990                          */
1991                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1992                             m->m_len <= MHLEN) {
1993                                 MGET(n, M_DONTWAIT, m->m_type);
1994                                 if (n != NULL) {
1995                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1996                                                 bcopy(m->m_data, n->m_data,
1997                                                       m->m_len);
1998                                                 n->m_len = m->m_len;
1999                                         } else {
2000                                                 m_free(n);
2001                                                 n = NULL;
2002                                         }
2003                                 }
2004                         }
2005                         if (n != NULL ||
2006                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2007                                 if (last->inp_flags & INP_CONTROLOPTS)
2008                                         ip6_savecontrol(last, n, &opts);
2009                                 /* strip intermediate headers */
2010                                 m_adj(n, off);
2011                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2012                                 if (sbappendaddr_locked(
2013                                     &last->inp_socket->so_rcv,
2014                                     (struct sockaddr *)&fromsa, n, opts)
2015                                     == 0) {
2016                                         /* should notify about lost packet */
2017                                         m_freem(n);
2018                                         if (opts) {
2019                                                 m_freem(opts);
2020                                         }
2021                                         SOCKBUF_UNLOCK(
2022                                             &last->inp_socket->so_rcv);
2023                                 } else
2024                                         sorwakeup_locked(last->inp_socket);
2025                                 opts = NULL;
2026                         }
2027                         INP_RUNLOCK(last);
2028                 }
2029                 last = in6p;
2030         }
2031         INP_INFO_RUNLOCK(&V_ripcbinfo);
2032         if (last != NULL) {
2033                 if (last->inp_flags & INP_CONTROLOPTS)
2034                         ip6_savecontrol(last, m, &opts);
2035                 /* strip intermediate headers */
2036                 m_adj(m, off);
2037
2038                 /* avoid using mbuf clusters if possible (see above) */
2039                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2040                     m->m_len <= MHLEN) {
2041                         struct mbuf *n;
2042
2043                         MGET(n, M_DONTWAIT, m->m_type);
2044                         if (n != NULL) {
2045                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2046                                         bcopy(m->m_data, n->m_data, m->m_len);
2047                                         n->m_len = m->m_len;
2048
2049                                         m_freem(m);
2050                                         m = n;
2051                                 } else {
2052                                         m_freem(n);
2053                                         n = NULL;
2054                                 }
2055                         }
2056                 }
2057                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2058                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2059                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2060                         m_freem(m);
2061                         if (opts)
2062                                 m_freem(opts);
2063                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2064                 } else
2065                         sorwakeup_locked(last->inp_socket);
2066                 INP_RUNLOCK(last);
2067         } else {
2068                 m_freem(m);
2069                 IP6STAT_DEC(ip6s_delivered);
2070         }
2071         return IPPROTO_DONE;
2072 }
2073
2074 /*
2075  * Reflect the ip6 packet back to the source.
2076  * OFF points to the icmp6 header, counted from the top of the mbuf.
2077  */
2078 void
2079 icmp6_reflect(struct mbuf *m, size_t off)
2080 {
2081         struct ip6_hdr *ip6;
2082         struct icmp6_hdr *icmp6;
2083         struct in6_ifaddr *ia = NULL;
2084         int plen;
2085         int type, code;
2086         struct ifnet *outif = NULL;
2087         struct in6_addr origdst, src, *srcp = NULL;
2088
2089         /* too short to reflect */
2090         if (off < sizeof(struct ip6_hdr)) {
2091                 nd6log((LOG_DEBUG,
2092                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2093                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2094                     __FILE__, __LINE__));
2095                 goto bad;
2096         }
2097
2098         /*
2099          * If there are extra headers between IPv6 and ICMPv6, strip
2100          * off that header first.
2101          */
2102 #ifdef DIAGNOSTIC
2103         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2104                 panic("assumption failed in icmp6_reflect");
2105 #endif
2106         if (off > sizeof(struct ip6_hdr)) {
2107                 size_t l;
2108                 struct ip6_hdr nip6;
2109
2110                 l = off - sizeof(struct ip6_hdr);
2111                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2112                 m_adj(m, l);
2113                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2114                 if (m->m_len < l) {
2115                         if ((m = m_pullup(m, l)) == NULL)
2116                                 return;
2117                 }
2118                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2119         } else /* off == sizeof(struct ip6_hdr) */ {
2120                 size_t l;
2121                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2122                 if (m->m_len < l) {
2123                         if ((m = m_pullup(m, l)) == NULL)
2124                                 return;
2125                 }
2126         }
2127         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2128         ip6 = mtod(m, struct ip6_hdr *);
2129         ip6->ip6_nxt = IPPROTO_ICMPV6;
2130         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2131         type = icmp6->icmp6_type; /* keep type for statistics */
2132         code = icmp6->icmp6_code; /* ditto. */
2133
2134         origdst = ip6->ip6_dst;
2135         /*
2136          * ip6_input() drops a packet if its src is multicast.
2137          * So, the src is never multicast.
2138          */
2139         ip6->ip6_dst = ip6->ip6_src;
2140
2141         /*
2142          * If the incoming packet was addressed directly to us (i.e. unicast),
2143          * use dst as the src for the reply.
2144          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2145          * (for example) when we encounter an error while forwarding procedure
2146          * destined to a duplicated address of ours.
2147          * Note that ip6_getdstifaddr() may fail if we are in an error handling
2148          * procedure of an outgoing packet of our own, in which case we need
2149          * to search in the ifaddr list.
2150          */
2151         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2152                 if ((ia = ip6_getdstifaddr(m))) {
2153                         if (!(ia->ia6_flags &
2154                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2155                                 srcp = &ia->ia_addr.sin6_addr;
2156                 } else {
2157                         struct sockaddr_in6 d;
2158
2159                         bzero(&d, sizeof(d));
2160                         d.sin6_family = AF_INET6;
2161                         d.sin6_len = sizeof(d);
2162                         d.sin6_addr = origdst;
2163                         ia = (struct in6_ifaddr *)
2164                             ifa_ifwithaddr((struct sockaddr *)&d);
2165                         if (ia &&
2166                             !(ia->ia6_flags &
2167                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2168                                 srcp = &ia->ia_addr.sin6_addr;
2169                         }
2170                 }
2171         }
2172
2173         if ((srcp != NULL) &&
2174             (in6_addrscope(srcp) != in6_addrscope(&ip6->ip6_src)))
2175                 srcp = NULL;
2176
2177         if (srcp == NULL) {
2178                 int e;
2179                 struct sockaddr_in6 sin6;
2180                 struct route_in6 ro;
2181
2182                 /*
2183                  * This case matches to multicasts, our anycast, or unicasts
2184                  * that we do not own.  Select a source address based on the
2185                  * source address of the erroneous packet.
2186                  */
2187                 bzero(&sin6, sizeof(sin6));
2188                 sin6.sin6_family = AF_INET6;
2189                 sin6.sin6_len = sizeof(sin6);
2190                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2191
2192                 bzero(&ro, sizeof(ro));
2193                 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2194                 if (ro.ro_rt)
2195                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2196                 if (e) {
2197                         char ip6buf[INET6_ADDRSTRLEN];
2198                         nd6log((LOG_DEBUG,
2199                             "icmp6_reflect: source can't be determined: "
2200                             "dst=%s, error=%d\n",
2201                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2202                         goto bad;
2203                 }
2204                 srcp = &src;
2205         }
2206
2207         ip6->ip6_src = *srcp;
2208         ip6->ip6_flow = 0;
2209         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2210         ip6->ip6_vfc |= IPV6_VERSION;
2211         ip6->ip6_nxt = IPPROTO_ICMPV6;
2212         if (outif)
2213                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2214         else if (m->m_pkthdr.rcvif) {
2215                 /* XXX: This may not be the outgoing interface */
2216                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2217         } else
2218                 ip6->ip6_hlim = V_ip6_defhlim;
2219
2220         icmp6->icmp6_cksum = 0;
2221         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2222             sizeof(struct ip6_hdr), plen);
2223
2224         /*
2225          * XXX option handling
2226          */
2227
2228         m->m_flags &= ~(M_BCAST|M_MCAST);
2229
2230         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2231         if (outif)
2232                 icmp6_ifoutstat_inc(outif, type, code);
2233
2234         if (ia != NULL)
2235                 ifa_free(&ia->ia_ifa);
2236         return;
2237
2238  bad:
2239         if (ia != NULL)
2240                 ifa_free(&ia->ia_ifa);
2241         m_freem(m);
2242         return;
2243 }
2244
2245 void
2246 icmp6_fasttimo(void)
2247 {
2248
2249         mld_fasttimo();
2250 }
2251
2252 void
2253 icmp6_slowtimo(void)
2254 {
2255
2256         mld_slowtimo();
2257 }
2258
2259 static const char *
2260 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2261     struct in6_addr *tgt6)
2262 {
2263         static char buf[1024];
2264         char ip6bufs[INET6_ADDRSTRLEN];
2265         char ip6bufd[INET6_ADDRSTRLEN];
2266         char ip6buft[INET6_ADDRSTRLEN];
2267         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2268             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2269             ip6_sprintf(ip6buft, tgt6));
2270         return buf;
2271 }
2272
2273 void
2274 icmp6_redirect_input(struct mbuf *m, int off)
2275 {
2276         struct ifnet *ifp;
2277         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2278         struct nd_redirect *nd_rd;
2279         int icmp6len = ntohs(ip6->ip6_plen);
2280         char *lladdr = NULL;
2281         int lladdrlen = 0;
2282         u_char *redirhdr = NULL;
2283         int redirhdrlen = 0;
2284         struct rtentry *rt = NULL;
2285         int is_router;
2286         int is_onlink;
2287         struct in6_addr src6 = ip6->ip6_src;
2288         struct in6_addr redtgt6;
2289         struct in6_addr reddst6;
2290         union nd_opts ndopts;
2291         char ip6buf[INET6_ADDRSTRLEN];
2292
2293         if (!m)
2294                 return;
2295
2296         ifp = m->m_pkthdr.rcvif;
2297
2298         if (!ifp)
2299                 return;
2300
2301         /* XXX if we are router, we don't update route by icmp6 redirect */
2302         if (V_ip6_forwarding)
2303                 goto freeit;
2304         if (!V_icmp6_rediraccept)
2305                 goto freeit;
2306
2307 #ifndef PULLDOWN_TEST
2308         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2309         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2310 #else
2311         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2312         if (nd_rd == NULL) {
2313                 ICMP6STAT_INC(icp6s_tooshort);
2314                 return;
2315         }
2316 #endif
2317         redtgt6 = nd_rd->nd_rd_target;
2318         reddst6 = nd_rd->nd_rd_dst;
2319
2320         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2321             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2322                 goto freeit;
2323         }
2324
2325         /* validation */
2326         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2327                 nd6log((LOG_ERR,
2328                     "ICMP6 redirect sent from %s rejected; "
2329                     "must be from linklocal\n",
2330                     ip6_sprintf(ip6buf, &src6)));
2331                 goto bad;
2332         }
2333         if (ip6->ip6_hlim != 255) {
2334                 nd6log((LOG_ERR,
2335                     "ICMP6 redirect sent from %s rejected; "
2336                     "hlim=%d (must be 255)\n",
2337                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2338                 goto bad;
2339         }
2340     {
2341         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2342         struct sockaddr_in6 sin6;
2343         struct in6_addr *gw6;
2344
2345         bzero(&sin6, sizeof(sin6));
2346         sin6.sin6_family = AF_INET6;
2347         sin6.sin6_len = sizeof(struct sockaddr_in6);
2348         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2349         rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
2350         if (rt) {
2351                 if (rt->rt_gateway == NULL ||
2352                     rt->rt_gateway->sa_family != AF_INET6) {
2353                         nd6log((LOG_ERR,
2354                             "ICMP6 redirect rejected; no route "
2355                             "with inet6 gateway found for redirect dst: %s\n",
2356                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2357                         RTFREE_LOCKED(rt);
2358                         goto bad;
2359                 }
2360
2361                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2362                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2363                         nd6log((LOG_ERR,
2364                             "ICMP6 redirect rejected; "
2365                             "not equal to gw-for-src=%s (must be same): "
2366                             "%s\n",
2367                             ip6_sprintf(ip6buf, gw6),
2368                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2369                         RTFREE_LOCKED(rt);
2370                         goto bad;
2371                 }
2372         } else {
2373                 nd6log((LOG_ERR,
2374                     "ICMP6 redirect rejected; "
2375                     "no route found for redirect dst: %s\n",
2376                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2377                 goto bad;
2378         }
2379         RTFREE_LOCKED(rt);
2380         rt = NULL;
2381     }
2382         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2383                 nd6log((LOG_ERR,
2384                     "ICMP6 redirect rejected; "
2385                     "redirect dst must be unicast: %s\n",
2386                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2387                 goto bad;
2388         }
2389
2390         is_router = is_onlink = 0;
2391         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2392                 is_router = 1;  /* router case */
2393         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2394                 is_onlink = 1;  /* on-link destination case */
2395         if (!is_router && !is_onlink) {
2396                 nd6log((LOG_ERR,
2397                     "ICMP6 redirect rejected; "
2398                     "neither router case nor onlink case: %s\n",
2399                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2400                 goto bad;
2401         }
2402         /* validation passed */
2403
2404         icmp6len -= sizeof(*nd_rd);
2405         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2406         if (nd6_options(&ndopts) < 0) {
2407                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2408                     "invalid ND option, rejected: %s\n",
2409                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2410                 /* nd6_options have incremented stats */
2411                 goto freeit;
2412         }
2413
2414         if (ndopts.nd_opts_tgt_lladdr) {
2415                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2416                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2417         }
2418
2419         if (ndopts.nd_opts_rh) {
2420                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2421                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2422         }
2423
2424         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2425                 nd6log((LOG_INFO,
2426                     "icmp6_redirect_input: lladdrlen mismatch for %s "
2427                     "(if %d, icmp6 packet %d): %s\n",
2428                     ip6_sprintf(ip6buf, &redtgt6),
2429                     ifp->if_addrlen, lladdrlen - 2,
2430                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2431                 goto bad;
2432         }
2433
2434         /* RFC 2461 8.3 */
2435         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2436             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2437
2438         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2439                 /* perform rtredirect */
2440                 struct sockaddr_in6 sdst;
2441                 struct sockaddr_in6 sgw;
2442                 struct sockaddr_in6 ssrc;
2443
2444                 bzero(&sdst, sizeof(sdst));
2445                 bzero(&sgw, sizeof(sgw));
2446                 bzero(&ssrc, sizeof(ssrc));
2447                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2448                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2449                         sizeof(struct sockaddr_in6);
2450                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2451                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2452                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2453                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2454                     (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2455                     (struct sockaddr *)&ssrc);
2456         }
2457         /* finally update cached route in each socket via pfctlinput */
2458     {
2459         struct sockaddr_in6 sdst;
2460
2461         bzero(&sdst, sizeof(sdst));
2462         sdst.sin6_family = AF_INET6;
2463         sdst.sin6_len = sizeof(struct sockaddr_in6);
2464         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2465         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2466 #ifdef IPSEC
2467         key_sa_routechange((struct sockaddr *)&sdst);
2468 #endif /* IPSEC */
2469     }
2470
2471  freeit:
2472         m_freem(m);
2473         return;
2474
2475  bad:
2476         ICMP6STAT_INC(icp6s_badredirect);
2477         m_freem(m);
2478 }
2479
2480 void
2481 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2482 {
2483         struct ifnet *ifp;      /* my outgoing interface */
2484         struct in6_addr *ifp_ll6;
2485         struct in6_addr *router_ll6;
2486         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2487         struct mbuf *m = NULL;  /* newly allocated one */
2488         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2489         struct nd_redirect *nd_rd;
2490         struct llentry *ln = NULL;
2491         size_t maxlen;
2492         u_char *p;
2493         struct ifnet *outif = NULL;
2494         struct sockaddr_in6 src_sa;
2495
2496         icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2497
2498         /* if we are not router, we don't send icmp6 redirect */
2499         if (!V_ip6_forwarding)
2500                 goto fail;
2501
2502         /* sanity check */
2503         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2504                 goto fail;
2505
2506         /*
2507          * Address check:
2508          *  the source address must identify a neighbor, and
2509          *  the destination address must not be a multicast address
2510          *  [RFC 2461, sec 8.2]
2511          */
2512         sip6 = mtod(m0, struct ip6_hdr *);
2513         bzero(&src_sa, sizeof(src_sa));
2514         src_sa.sin6_family = AF_INET6;
2515         src_sa.sin6_len = sizeof(src_sa);
2516         src_sa.sin6_addr = sip6->ip6_src;
2517         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2518                 goto fail;
2519         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2520                 goto fail;      /* what should we do here? */
2521
2522         /* rate limit */
2523         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2524                 goto fail;
2525
2526         /*
2527          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2528          * we almost always ask for an mbuf cluster for simplicity.
2529          * (MHLEN < IPV6_MMTU is almost always true)
2530          */
2531 #if IPV6_MMTU >= MCLBYTES
2532 # error assumption failed about IPV6_MMTU and MCLBYTES
2533 #endif
2534         MGETHDR(m, M_DONTWAIT, MT_HEADER);
2535         if (m && IPV6_MMTU >= MHLEN)
2536                 MCLGET(m, M_DONTWAIT);
2537         if (!m)
2538                 goto fail;
2539         m->m_pkthdr.rcvif = NULL;
2540         m->m_len = 0;
2541         maxlen = M_TRAILINGSPACE(m);
2542         maxlen = min(IPV6_MMTU, maxlen);
2543         /* just for safety */
2544         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2545             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2546                 goto fail;
2547         }
2548
2549         {
2550                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2551                 struct in6_ifaddr *ia;
2552                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2553                                                  IN6_IFF_NOTREADY|
2554                                                  IN6_IFF_ANYCAST)) == NULL)
2555                         goto fail;
2556                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2557                 /* XXXRW: reference released prematurely. */
2558                 ifa_free(&ia->ia_ifa);
2559         }
2560
2561         /* get ip6 linklocal address for the router. */
2562         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2563                 struct sockaddr_in6 *sin6;
2564                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2565                 router_ll6 = &sin6->sin6_addr;
2566                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2567                         router_ll6 = (struct in6_addr *)NULL;
2568         } else
2569                 router_ll6 = (struct in6_addr *)NULL;
2570
2571         /* ip6 */
2572         ip6 = mtod(m, struct ip6_hdr *);
2573         ip6->ip6_flow = 0;
2574         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2575         ip6->ip6_vfc |= IPV6_VERSION;
2576         /* ip6->ip6_plen will be set later */
2577         ip6->ip6_nxt = IPPROTO_ICMPV6;
2578         ip6->ip6_hlim = 255;
2579         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2580         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2581         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2582
2583         /* ND Redirect */
2584         nd_rd = (struct nd_redirect *)(ip6 + 1);
2585         nd_rd->nd_rd_type = ND_REDIRECT;
2586         nd_rd->nd_rd_code = 0;
2587         nd_rd->nd_rd_reserved = 0;
2588         if (rt->rt_flags & RTF_GATEWAY) {
2589                 /*
2590                  * nd_rd->nd_rd_target must be a link-local address in
2591                  * better router cases.
2592                  */
2593                 if (!router_ll6)
2594                         goto fail;
2595                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2596                     sizeof(nd_rd->nd_rd_target));
2597                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2598                     sizeof(nd_rd->nd_rd_dst));
2599         } else {
2600                 /* make sure redtgt == reddst */
2601                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2602                     sizeof(nd_rd->nd_rd_target));
2603                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2604                     sizeof(nd_rd->nd_rd_dst));
2605         }
2606
2607         p = (u_char *)(nd_rd + 1);
2608
2609         if (!router_ll6)
2610                 goto nolladdropt;
2611
2612         {
2613                 /* target lladdr option */
2614                 int len;
2615                 struct nd_opt_hdr *nd_opt;
2616                 char *lladdr;
2617
2618                 IF_AFDATA_LOCK(ifp);
2619                 ln = nd6_lookup(router_ll6, 0, ifp);
2620                 IF_AFDATA_UNLOCK(ifp);
2621                 if (ln == NULL)
2622                         goto nolladdropt;
2623
2624                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2625                 len = (len + 7) & ~7;   /* round by 8 */
2626                 /* safety check */
2627                 if (len + (p - (u_char *)ip6) > maxlen)
2628                         goto nolladdropt;
2629
2630                 if (ln->la_flags & LLE_VALID) {
2631                         nd_opt = (struct nd_opt_hdr *)p;
2632                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2633                         nd_opt->nd_opt_len = len >> 3;
2634                         lladdr = (char *)(nd_opt + 1);
2635                         bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2636                         p += len;
2637                 }
2638         }
2639 nolladdropt:
2640         if (ln != NULL)
2641                 LLE_RUNLOCK(ln);
2642
2643         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2644
2645         /* just to be safe */
2646 #ifdef M_DECRYPTED      /*not openbsd*/
2647         if (m0->m_flags & M_DECRYPTED)
2648                 goto noredhdropt;
2649 #endif
2650         if (p - (u_char *)ip6 > maxlen)
2651                 goto noredhdropt;
2652
2653         {
2654                 /* redirected header option */
2655                 int len;
2656                 struct nd_opt_rd_hdr *nd_opt_rh;
2657
2658                 /*
2659                  * compute the maximum size for icmp6 redirect header option.
2660                  * XXX room for auth header?
2661                  */
2662                 len = maxlen - (p - (u_char *)ip6);
2663                 len &= ~7;
2664
2665                 /* This is just for simplicity. */
2666                 if (m0->m_pkthdr.len != m0->m_len) {
2667                         if (m0->m_next) {
2668                                 m_freem(m0->m_next);
2669                                 m0->m_next = NULL;
2670                         }
2671                         m0->m_pkthdr.len = m0->m_len;
2672                 }
2673
2674                 /*
2675                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2676                  * about padding/truncate rule for the original IP packet.
2677                  * From the discussion on IPv6imp in Feb 1999,
2678                  * the consensus was:
2679                  * - "attach as much as possible" is the goal
2680                  * - pad if not aligned (original size can be guessed by
2681                  *   original ip6 header)
2682                  * Following code adds the padding if it is simple enough,
2683                  * and truncates if not.
2684                  */
2685                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2686                         panic("assumption failed in %s:%d", __FILE__,
2687                             __LINE__);
2688
2689                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2690                         /* not enough room, truncate */
2691                         m0->m_pkthdr.len = m0->m_len = len -
2692                             sizeof(*nd_opt_rh);
2693                 } else {
2694                         /* enough room, pad or truncate */
2695                         size_t extra;
2696
2697                         extra = m0->m_pkthdr.len % 8;
2698                         if (extra) {
2699                                 /* pad if easy enough, truncate if not */
2700                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2701                                         /* pad */
2702                                         m0->m_len += (8 - extra);
2703                                         m0->m_pkthdr.len += (8 - extra);
2704                                 } else {
2705                                         /* truncate */
2706                                         m0->m_pkthdr.len -= extra;
2707                                         m0->m_len -= extra;
2708                                 }
2709                         }
2710                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2711                         m0->m_pkthdr.len = m0->m_len = len -
2712                             sizeof(*nd_opt_rh);
2713                 }
2714
2715                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2716                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2717                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2718                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2719                 p += sizeof(*nd_opt_rh);
2720                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2721
2722                 /* connect m0 to m */
2723                 m_tag_delete_chain(m0, NULL);
2724                 m0->m_flags &= ~M_PKTHDR;
2725                 m->m_next = m0;
2726                 m->m_pkthdr.len = m->m_len + m0->m_len;
2727                 m0 = NULL;
2728         }
2729 noredhdropt:;
2730         if (m0) {
2731                 m_freem(m0);
2732                 m0 = NULL;
2733         }
2734
2735         /* XXX: clear embedded link IDs in the inner header */
2736         in6_clearscope(&sip6->ip6_src);
2737         in6_clearscope(&sip6->ip6_dst);
2738         in6_clearscope(&nd_rd->nd_rd_target);
2739         in6_clearscope(&nd_rd->nd_rd_dst);
2740
2741         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2742
2743         nd_rd->nd_rd_cksum = 0;
2744         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2745             sizeof(*ip6), ntohs(ip6->ip6_plen));
2746
2747         /* send the packet to outside... */
2748         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2749         if (outif) {
2750                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2751                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2752         }
2753         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2754
2755         return;
2756
2757 fail:
2758         if (m)
2759                 m_freem(m);
2760         if (m0)
2761                 m_freem(m0);
2762 }
2763
2764 /*
2765  * ICMPv6 socket option processing.
2766  */
2767 int
2768 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2769 {
2770         int error = 0;
2771         int optlen;
2772         struct inpcb *inp = sotoinpcb(so);
2773         int level, op, optname;
2774
2775         if (sopt) {
2776                 level = sopt->sopt_level;
2777                 op = sopt->sopt_dir;
2778                 optname = sopt->sopt_name;
2779                 optlen = sopt->sopt_valsize;
2780         } else
2781                 level = op = optname = optlen = 0;
2782
2783         if (level != IPPROTO_ICMPV6) {
2784                 return EINVAL;
2785         }
2786
2787         switch (op) {
2788         case PRCO_SETOPT:
2789                 switch (optname) {
2790                 case ICMP6_FILTER:
2791                     {
2792                         struct icmp6_filter ic6f;
2793
2794                         if (optlen != sizeof(ic6f)) {
2795                                 error = EMSGSIZE;
2796                                 break;
2797                         }
2798                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2799                         if (error == 0) {
2800                                 INP_WLOCK(inp);
2801                                 *inp->in6p_icmp6filt = ic6f;
2802                                 INP_WUNLOCK(inp);
2803                         }
2804                         break;
2805                     }
2806
2807                 default:
2808                         error = ENOPROTOOPT;
2809                         break;
2810                 }
2811                 break;
2812
2813         case PRCO_GETOPT:
2814                 switch (optname) {
2815                 case ICMP6_FILTER:
2816                     {
2817                         struct icmp6_filter ic6f;
2818
2819                         INP_RLOCK(inp);
2820                         ic6f = *inp->in6p_icmp6filt;
2821                         INP_RUNLOCK(inp);
2822                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2823                         break;
2824                     }
2825
2826                 default:
2827                         error = ENOPROTOOPT;
2828                         break;
2829                 }
2830                 break;
2831         }
2832
2833         return (error);
2834 }
2835
2836 /*
2837  * Perform rate limit check.
2838  * Returns 0 if it is okay to send the icmp6 packet.
2839  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2840  * limitation.
2841  *
2842  * XXX per-destination/type check necessary?
2843  *
2844  * dst - not used at this moment
2845  * type - not used at this moment
2846  * code - not used at this moment
2847  */
2848 static int
2849 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2850     const int code)
2851 {
2852         int ret;
2853
2854         ret = 0;        /* okay to send */
2855
2856         /* PPS limit */
2857         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2858             V_icmp6errppslim)) {
2859                 /* The packet is subject to rate limit */
2860                 ret++;
2861         }
2862
2863         return ret;
2864 }