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  * 3. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #define MBUF_PRIVATE    /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70
  71 #include <sys/param.h>
  72 #include <sys/domain.h>
  73 #include <sys/jail.h>
  74 #include <sys/kernel.h>
  75 #include <sys/lock.h>
  76 #include <sys/malloc.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/proc.h>
  79 #include <sys/protosw.h>
  80 #include <sys/signalvar.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #include <sys/sx.h>
  84 #include <sys/syslog.h>
  85 #include <sys/systm.h>
  86 #include <sys/time.h>
  87
  88 #include <net/if.h>
  89 #include <net/if_var.h>
  90 #include <net/if_dl.h>
  91 #include <net/if_llatbl.h>
  92 #include <net/if_types.h>
  93 #include <net/route.h>
  94 #include <net/vnet.h>
  95
  96 #include <netinet/in.h>
  97 #include <netinet/in_pcb.h>
  98 #include <netinet/in_var.h>
  99 #include <netinet/ip6.h>
 100 #include <netinet/icmp6.h>
 101 #include <netinet/tcp_var.h>
 102
 103 #include <netinet6/in6_fib.h>
 104 #include <netinet6/in6_ifattach.h>
 105 #include <netinet6/in6_pcb.h>
 106 #include <netinet6/ip6protosw.h>
 107 #include <netinet6/ip6_var.h>
 108 #include <netinet6/scope6_var.h>
 109 #include <netinet6/mld6_var.h>
 110 #include <netinet6/nd6.h>
 111 #include <netinet6/send.h>
 112
 113 extern struct domain inet6domain;
 114
 115 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
 116 VNET_PCPUSTAT_SYSINIT(icmp6stat);
 117
 118 #ifdef VIMAGE
 119 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
 120 #endif /* VIMAGE */
 121
 122 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 123 VNET_DECLARE(struct inpcbhead, ripcb);
 124 VNET_DECLARE(int, icmp6errppslim);
 125 static VNET_DEFINE(int, icmp6errpps_count) = 0;
 126 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 127 VNET_DECLARE(int, icmp6_nodeinfo);
 128
 129 #define V_ripcbinfo                     VNET(ripcbinfo)
 130 #define V_ripcb                         VNET(ripcb)
 131 #define V_icmp6errppslim                VNET(icmp6errppslim)
 132 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 133 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 134 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 135
 136 static void icmp6_errcount(int, int);
 137 static int icmp6_rip6_input(struct mbuf **, int);
 138 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 139 static const char *icmp6_redirect_diag(struct in6_addr *,
 140         struct in6_addr *, struct in6_addr *);
 141 static struct mbuf *ni6_input(struct mbuf *, int);
 142 static struct mbuf *ni6_nametodns(const char *, int, int);
 143 static int ni6_dnsmatch(const char *, int, const char *, int);
 144 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 145                           struct ifnet **, struct in6_addr *);
 146 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 147                                 struct ifnet *, int);
 148 static int icmp6_notify_error(struct mbuf **, int, int, int);
 149
 150 /*
 151  * Kernel module interface for updating icmp6stat.  The argument is an index
 152  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 153  * general layout of icmp6stat into the caller, it doesn't encode its
 154  * location, so that future changes to add, for example, per-CPU stats
 155  * support won't cause binary compatibility problems for kernel modules.
 156  */
 157 void
 158 kmod_icmp6stat_inc(int statnum)
 159 {
 160
 161         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 162 }
 163
 164 static void
 165 icmp6_errcount(int type, int code)
 166 {
 167         switch (type) {
 168         case ICMP6_DST_UNREACH:
 169                 switch (code) {
 170                 case ICMP6_DST_UNREACH_NOROUTE:
 171                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 172                         return;
 173                 case ICMP6_DST_UNREACH_ADMIN:
 174                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 175                         return;
 176                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 177                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 178                         return;
 179                 case ICMP6_DST_UNREACH_ADDR:
 180                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 181                         return;
 182                 case ICMP6_DST_UNREACH_NOPORT:
 183                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 184                         return;
 185                 }
 186                 break;
 187         case ICMP6_PACKET_TOO_BIG:
 188                 ICMP6STAT_INC(icp6s_opacket_too_big);
 189                 return;
 190         case ICMP6_TIME_EXCEEDED:
 191                 switch (code) {
 192                 case ICMP6_TIME_EXCEED_TRANSIT:
 193                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 194                         return;
 195                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 196                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 197                         return;
 198                 }
 199                 break;
 200         case ICMP6_PARAM_PROB:
 201                 switch (code) {
 202                 case ICMP6_PARAMPROB_HEADER:
 203                         ICMP6STAT_INC(icp6s_oparamprob_header);
 204                         return;
 205                 case ICMP6_PARAMPROB_NEXTHEADER:
 206                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 207                         return;
 208                 case ICMP6_PARAMPROB_OPTION:
 209                         ICMP6STAT_INC(icp6s_oparamprob_option);
 210                         return;
 211                 }
 212                 break;
 213         case ND_REDIRECT:
 214                 ICMP6STAT_INC(icp6s_oredirect);
 215                 return;
 216         }
 217         ICMP6STAT_INC(icp6s_ounknown);
 218 }
 219
 220 /*
 221  * A wrapper function for icmp6_error() necessary when the erroneous packet
 222  * may not contain enough scope zone information.
 223  */
 224 void
 225 icmp6_error2(struct mbuf *m, int type, int code, int param,
 226     struct ifnet *ifp)
 227 {
 228         struct ip6_hdr *ip6;
 229
 230         if (ifp == NULL)
 231                 return;
 232
 233 #ifndef PULLDOWN_TEST
 234         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 235 #else
 236         if (m->m_len < sizeof(struct ip6_hdr)) {
 237                 m = m_pullup(m, sizeof(struct ip6_hdr));
 238                 if (m == NULL)
 239                         return;
 240         }
 241 #endif
 242
 243         ip6 = mtod(m, struct ip6_hdr *);
 244
 245         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 246                 return;
 247         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 248                 return;
 249
 250         icmp6_error(m, type, code, param);
 251 }
 252
 253 /*
 254  * Generate an error packet of type error in response to bad IP6 packet.
 255  */
 256 void
 257 icmp6_error(struct mbuf *m, int type, int code, int param)
 258 {
 259         struct ip6_hdr *oip6, *nip6;
 260         struct icmp6_hdr *icmp6;
 261         u_int preplen;
 262         int off;
 263         int nxt;
 264
 265         ICMP6STAT_INC(icp6s_error);
 266
 267         /* count per-type-code statistics */
 268         icmp6_errcount(type, code);
 269
 270 #ifdef M_DECRYPTED      /*not openbsd*/
 271         if (m->m_flags & M_DECRYPTED) {
 272                 ICMP6STAT_INC(icp6s_canterror);
 273                 goto freeit;
 274         }
 275 #endif
 276
 277 #ifndef PULLDOWN_TEST
 278         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 279 #else
 280         if (m->m_len < sizeof(struct ip6_hdr)) {
 281                 m = m_pullup(m, sizeof(struct ip6_hdr));
 282                 if (m == NULL)
 283                         return;
 284         }
 285 #endif
 286         oip6 = mtod(m, struct ip6_hdr *);
 287
 288         /*
 289          * If the destination address of the erroneous packet is a multicast
 290          * address, or the packet was sent using link-layer multicast,
 291          * we should basically suppress sending an error (RFC 2463, Section
 292          * 2.4).
 293          * We have two exceptions (the item e.2 in that section):
 294          * - the Packet Too Big message can be sent for path MTU discovery.
 295          * - the Parameter Problem Message that can be allowed an icmp6 error
 296          *   in the option type field.  This check has been done in
 297          *   ip6_unknown_opt(), so we can just check the type and code.
 298          */
 299         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 300              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 301             (type != ICMP6_PACKET_TOO_BIG &&
 302              (type != ICMP6_PARAM_PROB ||
 303               code != ICMP6_PARAMPROB_OPTION)))
 304                 goto freeit;
 305
 306         /*
 307          * RFC 2463, 2.4 (e.5): source address check.
 308          * XXX: the case of anycast source?
 309          */
 310         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 311             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 312                 goto freeit;
 313
 314         /*
 315          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 316          * don't do it.
 317          */
 318         nxt = -1;
 319         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 320         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 321                 struct icmp6_hdr *icp;
 322
 323 #ifndef PULLDOWN_TEST
 324                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 325                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 326 #else
 327                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 328                         sizeof(*icp));
 329                 if (icp == NULL) {
 330                         ICMP6STAT_INC(icp6s_tooshort);
 331                         return;
 332                 }
 333 #endif
 334                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 335                     icp->icmp6_type == ND_REDIRECT) {
 336                         /*
 337                          * ICMPv6 error
 338                          * Special case: for redirect (which is
 339                          * informational) we must not send icmp6 error.
 340                          */
 341                         ICMP6STAT_INC(icp6s_canterror);
 342                         goto freeit;
 343                 } else {
 344                         /* ICMPv6 informational - send the error */
 345                 }
 346         } else {
 347                 /* non-ICMPv6 - send the error */
 348         }
 349
 350         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 351
 352         /* Finally, do rate limitation check. */
 353         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 354                 ICMP6STAT_INC(icp6s_toofreq);
 355                 goto freeit;
 356         }
 357
 358         /*
 359          * OK, ICMP6 can be generated.
 360          */
 361
 362         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 363                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 364
 365         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 366         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 367         if (m == NULL) {
 368                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 369                 return;
 370         }
 371
 372         nip6 = mtod(m, struct ip6_hdr *);
 373         nip6->ip6_src  = oip6->ip6_src;
 374         nip6->ip6_dst  = oip6->ip6_dst;
 375
 376         in6_clearscope(&oip6->ip6_src);
 377         in6_clearscope(&oip6->ip6_dst);
 378
 379         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 380         icmp6->icmp6_type = type;
 381         icmp6->icmp6_code = code;
 382         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 383
 384         /*
 385          * icmp6_reflect() is designed to be in the input path.
 386          * icmp6_error() can be called from both input and output path,
 387          * and if we are in output path rcvif could contain bogus value.
 388          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 389          * information in ip header (nip6).
 390          */
 391         m->m_pkthdr.rcvif = NULL;
 392
 393         ICMP6STAT_INC(icp6s_outhist[type]);
 394         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 395
 396         return;
 397
 398   freeit:
 399         /*
 400          * If we can't tell whether or not we can generate ICMP6, free it.
 401          */
 402         m_freem(m);
 403 }
 404
 405 /*
 406  * Process a received ICMP6 message.
 407  */
 408 int
 409 icmp6_input(struct mbuf **mp, int *offp, int proto)
 410 {
 411         struct mbuf *m = *mp, *n;
 412         struct ifnet *ifp;
 413         struct ip6_hdr *ip6, *nip6;
 414         struct icmp6_hdr *icmp6, *nicmp6;
 415         int off = *offp;
 416         int icmp6len = m->m_pkthdr.len - *offp;
 417         int code, sum, noff;
 418         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 419         int ip6len, error;
 420
 421         ifp = m->m_pkthdr.rcvif;
 422
 423 #ifndef PULLDOWN_TEST
 424         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 425         /* m might change if M_LOOP.  So, call mtod after this */
 426 #endif
 427
 428         /*
 429          * Locate icmp6 structure in mbuf, and check
 430          * that not corrupted and of at least minimum length
 431          */
 432
 433         ip6 = mtod(m, struct ip6_hdr *);
 434         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 435         if (icmp6len < sizeof(struct icmp6_hdr)) {
 436                 ICMP6STAT_INC(icp6s_tooshort);
 437                 goto freeit;
 438         }
 439
 440         /*
 441          * Check multicast group membership.
 442          * Note: SSM filters are not applied for ICMPv6 traffic.
 443          */
 444         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 445                 struct in6_multi        *inm;
 446
 447                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 448                 if (inm == NULL) {
 449                         IP6STAT_INC(ip6s_notmember);
 450                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 451                         goto freeit;
 452                 }
 453         }
 454
 455         /*
 456          * calculate the checksum
 457          */
 458 #ifndef PULLDOWN_TEST
 459         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 460 #else
 461         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 462         if (icmp6 == NULL) {
 463                 ICMP6STAT_INC(icp6s_tooshort);
 464                 return IPPROTO_DONE;
 465         }
 466 #endif
 467         code = icmp6->icmp6_code;
 468
 469         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 470                 nd6log((LOG_ERR,
 471                     "ICMP6 checksum error(%d|%x) %s\n",
 472                     icmp6->icmp6_type, sum,
 473                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 474                 ICMP6STAT_INC(icp6s_checksum);
 475                 goto freeit;
 476         }
 477
 478         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 479         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 480         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 481                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 482
 483         switch (icmp6->icmp6_type) {
 484         case ICMP6_DST_UNREACH:
 485                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 486                 switch (code) {
 487                 case ICMP6_DST_UNREACH_NOROUTE:
 488                 case ICMP6_DST_UNREACH_ADDR:    /* PRC_HOSTDEAD is a DOS */
 489                         code = PRC_UNREACH_NET;
 490                         break;
 491                 case ICMP6_DST_UNREACH_ADMIN:
 492                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 493                         code = PRC_UNREACH_ADMIN_PROHIB;
 494                         break;
 495                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 496                         /* I mean "source address was incorrect." */
 497                         code = PRC_PARAMPROB;
 498                         break;
 499                 case ICMP6_DST_UNREACH_NOPORT:
 500                         code = PRC_UNREACH_PORT;
 501                         break;
 502                 default:
 503                         goto badcode;
 504                 }
 505                 goto deliver;
 506                 break;
 507
 508         case ICMP6_PACKET_TOO_BIG:
 509                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 510
 511                 /* validation is made in icmp6_mtudisc_update */
 512
 513                 code = PRC_MSGSIZE;
 514
 515                 /*
 516                  * Updating the path MTU will be done after examining
 517                  * intermediate extension headers.
 518                  */
 519                 goto deliver;
 520                 break;
 521
 522         case ICMP6_TIME_EXCEEDED:
 523                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 524                 switch (code) {
 525                 case ICMP6_TIME_EXCEED_TRANSIT:
 526                         code = PRC_TIMXCEED_INTRANS;
 527                         break;
 528                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 529                         code = PRC_TIMXCEED_REASS;
 530                         break;
 531                 default:
 532                         goto badcode;
 533                 }
 534                 goto deliver;
 535                 break;
 536
 537         case ICMP6_PARAM_PROB:
 538                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 539                 switch (code) {
 540                 case ICMP6_PARAMPROB_NEXTHEADER:
 541                         code = PRC_UNREACH_PROTOCOL;
 542                         break;
 543                 case ICMP6_PARAMPROB_HEADER:
 544                 case ICMP6_PARAMPROB_OPTION:
 545                         code = PRC_PARAMPROB;
 546                         break;
 547                 default:
 548                         goto badcode;
 549                 }
 550                 goto deliver;
 551                 break;
 552
 553         case ICMP6_ECHO_REQUEST:
 554                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 555                 if (code != 0)
 556                         goto badcode;
 557                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 558                         /* Give up remote */
 559                         break;
 560                 }
 561                 if (!M_WRITABLE(n)
 562                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 563                         struct mbuf *n0 = n;
 564                         int n0len;
 565
 566                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 567                         n = m_gethdr(M_NOWAIT, n0->m_type);
 568                         if (n == NULL) {
 569                                 /* Give up remote */
 570                                 m_freem(n0);
 571                                 break;
 572                         }
 573
 574                         m_move_pkthdr(n, n0);   /* FIB copied. */
 575                         n0len = n0->m_pkthdr.len;       /* save for use below */
 576                         /*
 577                          * Copy IPv6 and ICMPv6 only.
 578                          */
 579                         nip6 = mtod(n, struct ip6_hdr *);
 580                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 581                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 582                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 583                         noff = sizeof(struct ip6_hdr);
 584                         /* new mbuf contains only ipv6+icmpv6 headers */
 585                         n->m_len = noff + sizeof(struct icmp6_hdr);
 586                         /*
 587                          * Adjust mbuf.  ip6_plen will be adjusted in
 588                          * ip6_output().
 589                          */
 590                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 591                         /* recalculate complete packet size */
 592                         n->m_pkthdr.len = n0len + (noff - off);
 593                         n->m_next = n0;
 594                 } else {
 595                         nip6 = mtod(n, struct ip6_hdr *);
 596                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 597                             sizeof(*nicmp6));
 598                         noff = off;
 599                 }
 600                 if (n) {
 601                         nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 602                         nicmp6->icmp6_code = 0;
 603                         ICMP6STAT_INC(icp6s_reflect);
 604                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 605                         icmp6_reflect(n, noff);
 606                 }
 607                 break;
 608
 609         case ICMP6_ECHO_REPLY:
 610                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 611                 if (code != 0)
 612                         goto badcode;
 613                 break;
 614
 615         case MLD_LISTENER_QUERY:
 616         case MLD_LISTENER_REPORT:
 617         case MLD_LISTENER_DONE:
 618         case MLDV2_LISTENER_REPORT:
 619                 /*
 620                  * Drop MLD traffic which is not link-local, has a hop limit
 621                  * of greater than 1 hop, or which does not have the
 622                  * IPv6 HBH Router Alert option.
 623                  * As IPv6 HBH options are stripped in ip6_input() we must
 624                  * check an mbuf header flag.
 625                  * XXX Should we also sanity check that these messages
 626                  * were directed to a link-local multicast prefix?
 627                  */
 628                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 629                         goto freeit;
 630                 if (mld_input(m, off, icmp6len) != 0)
 631                         return (IPPROTO_DONE);
 632                 /* m stays. */
 633                 break;
 634
 635         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 636             {
 637                 enum { WRU, FQDN } mode;
 638
 639                 if (!V_icmp6_nodeinfo)
 640                         break;
 641
 642                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 643                         mode = WRU;
 644                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 645                         mode = FQDN;
 646                 else
 647                         goto badlen;
 648
 649                 if (mode == FQDN) {
 650 #ifndef PULLDOWN_TEST
 651                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 652                             IPPROTO_DONE);
 653 #endif
 654                         n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 655                         if (n)
 656                                 n = ni6_input(n, off);
 657                         /* XXX meaningless if n == NULL */
 658                         noff = sizeof(struct ip6_hdr);
 659                 } else {
 660                         struct prison *pr;
 661                         u_char *p;
 662                         int maxhlen, hlen;
 663
 664                         /*
 665                          * XXX: this combination of flags is pointless,
 666                          * but should we keep this for compatibility?
 667                          */
 668                         if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
 669                             ICMP6_NODEINFO_TMPADDROK)) !=
 670                             (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
 671                                 break;
 672
 673                         if (code != 0)
 674                                 goto badcode;
 675
 676                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 677                         n = m_gethdr(M_NOWAIT, m->m_type);
 678                         if (n == NULL) {
 679                                 /* Give up remote */
 680                                 break;
 681                         }
 682                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 683                                 /*
 684                                  * Previous code did a blind M_COPY_PKTHDR
 685                                  * and said "just for rcvif".  If true, then
 686                                  * we could tolerate the dup failing (due to
 687                                  * the deep copy of the tag chain).  For now
 688                                  * be conservative and just fail.
 689                                  */
 690                                 m_free(n);
 691                                 n = NULL;
 692                                 break;
 693                         }
 694                         maxhlen = M_TRAILINGSPACE(n) -
 695                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 696                         pr = curthread->td_ucred->cr_prison;
 697                         mtx_lock(&pr->pr_mtx);
 698                         hlen = strlen(pr->pr_hostname);
 699                         if (maxhlen > hlen)
 700                                 maxhlen = hlen;
 701                         /*
 702                          * Copy IPv6 and ICMPv6 only.
 703                          */
 704                         nip6 = mtod(n, struct ip6_hdr *);
 705                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 706                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 707                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 708                         p = (u_char *)(nicmp6 + 1);
 709                         bzero(p, 4);
 710                         /* meaningless TTL */
 711                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 712                         mtx_unlock(&pr->pr_mtx);
 713                         noff = sizeof(struct ip6_hdr);
 714                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 715                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 716                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 717                         nicmp6->icmp6_code = 0;
 718                 }
 719                 if (n) {
 720                         ICMP6STAT_INC(icp6s_reflect);
 721                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 722                         icmp6_reflect(n, noff);
 723                 }
 724                 break;
 725             }
 726
 727         case ICMP6_WRUREPLY:
 728                 if (code != 0)
 729                         goto badcode;
 730                 break;
 731
 732         case ND_ROUTER_SOLICIT:
 733                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 734                 if (code != 0)
 735                         goto badcode;
 736                 if (icmp6len < sizeof(struct nd_router_solicit))
 737                         goto badlen;
 738                 if (send_sendso_input_hook != NULL) {
 739                         IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
 740                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 741                         if (error == 0) {
 742                                 m = NULL;
 743                                 goto freeit;
 744                         }
 745                 }
 746                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 747                 nd6_rs_input(m, off, icmp6len);
 748                 m = n;
 749                 if (m == NULL)
 750                         goto freeit;
 751                 break;
 752
 753         case ND_ROUTER_ADVERT:
 754                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 755                 if (code != 0)
 756                         goto badcode;
 757                 if (icmp6len < sizeof(struct nd_router_advert))
 758                         goto badlen;
 759                 if (send_sendso_input_hook != NULL) {
 760                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 761                         if (error == 0) {
 762                                 m = NULL;
 763                                 goto freeit;
 764                         }
 765                 }
 766                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 767                 nd6_ra_input(m, off, icmp6len);
 768                 m = n;
 769                 if (m == NULL)
 770                         goto freeit;
 771                 break;
 772
 773         case ND_NEIGHBOR_SOLICIT:
 774                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 775                 if (code != 0)
 776                         goto badcode;
 777                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 778                         goto badlen;
 779                 if (send_sendso_input_hook != NULL) {
 780                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 781                         if (error == 0) {
 782                                 m = NULL;
 783                                 goto freeit;
 784                         }
 785                 }
 786                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 787                 nd6_ns_input(m, off, icmp6len);
 788                 m = n;
 789                 if (m == NULL)
 790                         goto freeit;
 791                 break;
 792
 793         case ND_NEIGHBOR_ADVERT:
 794                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 795                 if (code != 0)
 796                         goto badcode;
 797                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 798                         goto badlen;
 799                 if (send_sendso_input_hook != NULL) {
 800                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 801                         if (error == 0) {
 802                                 m = NULL;
 803                                 goto freeit;
 804                         }
 805                 }
 806                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 807                 nd6_na_input(m, off, icmp6len);
 808                 m = n;
 809                 if (m == NULL)
 810                         goto freeit;
 811                 break;
 812
 813         case ND_REDIRECT:
 814                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 815                 if (code != 0)
 816                         goto badcode;
 817                 if (icmp6len < sizeof(struct nd_redirect))
 818                         goto badlen;
 819                 if (send_sendso_input_hook != NULL) {
 820                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 821                         if (error == 0) {
 822                                 m = NULL;
 823                                 goto freeit;
 824                         }
 825                 }
 826                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 827                 icmp6_redirect_input(m, off);
 828                 m = n;
 829                 if (m == NULL)
 830                         goto freeit;
 831                 break;
 832
 833         case ICMP6_ROUTER_RENUMBERING:
 834                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 835                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 836                         goto badcode;
 837                 if (icmp6len < sizeof(struct icmp6_router_renum))
 838                         goto badlen;
 839                 break;
 840
 841         default:
 842                 nd6log((LOG_DEBUG,
 843                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 844                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 845                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 846                     ifp ? ifp->if_index : 0));
 847                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 848                         /* ICMPv6 error: MUST deliver it by spec... */
 849                         code = PRC_NCMDS;
 850                         /* deliver */
 851                 } else {
 852                         /* ICMPv6 informational: MUST not deliver */
 853                         break;
 854                 }
 855         deliver:
 856                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 857                         /* In this case, m should've been freed. */
 858                         return (IPPROTO_DONE);
 859                 }
 860                 break;
 861
 862         badcode:
 863                 ICMP6STAT_INC(icp6s_badcode);
 864                 break;
 865
 866         badlen:
 867                 ICMP6STAT_INC(icp6s_badlen);
 868                 break;
 869         }
 870
 871         /* deliver the packet to appropriate sockets */
 872         icmp6_rip6_input(&m, *offp);
 873
 874         return IPPROTO_DONE;
 875
 876  freeit:
 877         m_freem(m);
 878         return IPPROTO_DONE;
 879 }
 880
 881 static int
 882 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 883 {
 884         struct mbuf *m = *mp;
 885         struct icmp6_hdr *icmp6;
 886         struct ip6_hdr *eip6;
 887         u_int32_t notifymtu;
 888         struct sockaddr_in6 icmp6src, icmp6dst;
 889
 890         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 891                 ICMP6STAT_INC(icp6s_tooshort);
 892                 goto freeit;
 893         }
 894 #ifndef PULLDOWN_TEST
 895         IP6_EXTHDR_CHECK(m, off,
 896             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 897         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 898 #else
 899         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 900             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 901         if (icmp6 == NULL) {
 902                 ICMP6STAT_INC(icp6s_tooshort);
 903                 return (-1);
 904         }
 905 #endif
 906         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 907
 908         /* Detect the upper level protocol */
 909         {
 910                 void (*ctlfunc)(int, struct sockaddr *, void *);
 911                 u_int8_t nxt = eip6->ip6_nxt;
 912                 int eoff = off + sizeof(struct icmp6_hdr) +
 913                     sizeof(struct ip6_hdr);
 914                 struct ip6ctlparam ip6cp;
 915                 struct in6_addr *finaldst = NULL;
 916                 int icmp6type = icmp6->icmp6_type;
 917                 struct ip6_frag *fh;
 918                 struct ip6_rthdr *rth;
 919                 struct ip6_rthdr0 *rth0;
 920                 int rthlen;
 921
 922                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 923                         struct ip6_ext *eh;
 924
 925                         switch (nxt) {
 926                         case IPPROTO_HOPOPTS:
 927                         case IPPROTO_DSTOPTS:
 928                         case IPPROTO_AH:
 929 #ifndef PULLDOWN_TEST
 930                                 IP6_EXTHDR_CHECK(m, 0,
 931                                     eoff + sizeof(struct ip6_ext), -1);
 932                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 933 #else
 934                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 935                                     eoff, sizeof(*eh));
 936                                 if (eh == NULL) {
 937                                         ICMP6STAT_INC(icp6s_tooshort);
 938                                         return (-1);
 939                                 }
 940 #endif
 941
 942                                 if (nxt == IPPROTO_AH)
 943                                         eoff += (eh->ip6e_len + 2) << 2;
 944                                 else
 945                                         eoff += (eh->ip6e_len + 1) << 3;
 946                                 nxt = eh->ip6e_nxt;
 947                                 break;
 948                         case IPPROTO_ROUTING:
 949                                 /*
 950                                  * When the erroneous packet contains a
 951                                  * routing header, we should examine the
 952                                  * header to determine the final destination.
 953                                  * Otherwise, we can't properly update
 954                                  * information that depends on the final
 955                                  * destination (e.g. path MTU).
 956                                  */
 957 #ifndef PULLDOWN_TEST
 958                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 959                                 rth = (struct ip6_rthdr *)
 960                                     (mtod(m, caddr_t) + eoff);
 961 #else
 962                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 963                                     eoff, sizeof(*rth));
 964                                 if (rth == NULL) {
 965                                         ICMP6STAT_INC(icp6s_tooshort);
 966                                         return (-1);
 967                                 }
 968 #endif
 969                                 rthlen = (rth->ip6r_len + 1) << 3;
 970                                 /*
 971                                  * XXX: currently there is no
 972                                  * officially defined type other
 973                                  * than type-0.
 974                                  * Note that if the segment left field
 975                                  * is 0, all intermediate hops must
 976                                  * have been passed.
 977                                  */
 978                                 if (rth->ip6r_segleft &&
 979                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 980                                         int hops;
 981
 982 #ifndef PULLDOWN_TEST
 983                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 984                                         rth0 = (struct ip6_rthdr0 *)
 985                                             (mtod(m, caddr_t) + eoff);
 986 #else
 987                                         IP6_EXTHDR_GET(rth0,
 988                                             struct ip6_rthdr0 *, m,
 989                                             eoff, rthlen);
 990                                         if (rth0 == NULL) {
 991                                                 ICMP6STAT_INC(icp6s_tooshort);
 992                                                 return (-1);
 993                                         }
 994 #endif
 995                                         /* just ignore a bogus header */
 996                                         if ((rth0->ip6r0_len % 2) == 0 &&
 997                                             (hops = rth0->ip6r0_len/2))
 998                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 999                                 }
1000                                 eoff += rthlen;
1001                                 nxt = rth->ip6r_nxt;
1002                                 break;
1003                         case IPPROTO_FRAGMENT:
1004 #ifndef PULLDOWN_TEST
1005                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1006                                     sizeof(struct ip6_frag), -1);
1007                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1008                                     eoff);
1009 #else
1010                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1011                                     eoff, sizeof(*fh));
1012                                 if (fh == NULL) {
1013                                         ICMP6STAT_INC(icp6s_tooshort);
1014                                         return (-1);
1015                                 }
1016 #endif
1017                                 /*
1018                                  * Data after a fragment header is meaningless
1019                                  * unless it is the first fragment, but
1020                                  * we'll go to the notify label for path MTU
1021                                  * discovery.
1022                                  */
1023                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1024                                         goto notify;
1025
1026                                 eoff += sizeof(struct ip6_frag);
1027                                 nxt = fh->ip6f_nxt;
1028                                 break;
1029                         default:
1030                                 /*
1031                                  * This case includes ESP and the No Next
1032                                  * Header.  In such cases going to the notify
1033                                  * label does not have any meaning
1034                                  * (i.e. ctlfunc will be NULL), but we go
1035                                  * anyway since we might have to update
1036                                  * path MTU information.
1037                                  */
1038                                 goto notify;
1039                         }
1040                 }
1041           notify:
1042 #ifndef PULLDOWN_TEST
1043                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1044 #else
1045                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1046                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1047                 if (icmp6 == NULL) {
1048                         ICMP6STAT_INC(icp6s_tooshort);
1049                         return (-1);
1050                 }
1051 #endif
1052
1053                 /*
1054                  * retrieve parameters from the inner IPv6 header, and convert
1055                  * them into sockaddr structures.
1056                  * XXX: there is no guarantee that the source or destination
1057                  * addresses of the inner packet are in the same scope as
1058                  * the addresses of the icmp packet.  But there is no other
1059                  * way to determine the zone.
1060                  */
1061                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1062
1063                 bzero(&icmp6dst, sizeof(icmp6dst));
1064                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1065                 icmp6dst.sin6_family = AF_INET6;
1066                 if (finaldst == NULL)
1067                         icmp6dst.sin6_addr = eip6->ip6_dst;
1068                 else
1069                         icmp6dst.sin6_addr = *finaldst;
1070                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1071                         goto freeit;
1072                 bzero(&icmp6src, sizeof(icmp6src));
1073                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1074                 icmp6src.sin6_family = AF_INET6;
1075                 icmp6src.sin6_addr = eip6->ip6_src;
1076                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1077                         goto freeit;
1078                 icmp6src.sin6_flowinfo =
1079                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1080
1081                 if (finaldst == NULL)
1082                         finaldst = &eip6->ip6_dst;
1083                 ip6cp.ip6c_m = m;
1084                 ip6cp.ip6c_icmp6 = icmp6;
1085                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1086                 ip6cp.ip6c_off = eoff;
1087                 ip6cp.ip6c_finaldst = finaldst;
1088                 ip6cp.ip6c_src = &icmp6src;
1089                 ip6cp.ip6c_nxt = nxt;
1090
1091                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1092                         notifymtu = ntohl(icmp6->icmp6_mtu);
1093                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1094                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1095                 }
1096
1097                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1098                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1099                 if (ctlfunc) {
1100                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1101                             &ip6cp);
1102                 }
1103         }
1104         *mp = m;
1105         return (0);
1106
1107   freeit:
1108         m_freem(m);
1109         return (-1);
1110 }
1111
1112 void
1113 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1114 {
1115         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1116         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1117         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1118         u_int mtu = ntohl(icmp6->icmp6_mtu);
1119         struct in_conninfo inc;
1120
1121 #if 0
1122         /*
1123          * RFC2460 section 5, last paragraph.
1124          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1125          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1126          * due to packet translator in the middle.
1127          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1128          * special handling.
1129          */
1130         if (mtu < IPV6_MMTU)
1131                 return;
1132 #endif
1133
1134         /*
1135          * we reject ICMPv6 too big with abnormally small value.
1136          * XXX what is the good definition of "abnormally small"?
1137          */
1138         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1139                 return;
1140
1141         if (!validated)
1142                 return;
1143
1144         /*
1145          * In case the suggested mtu is less than IPV6_MMTU, we
1146          * only need to remember that it was for above mentioned
1147          * "alwaysfrag" case.
1148          * Try to be as close to the spec as possible.
1149          */
1150         if (mtu < IPV6_MMTU)
1151                 mtu = IPV6_MMTU - 8;
1152
1153         bzero(&inc, sizeof(inc));
1154         inc.inc_fibnum = M_GETFIB(m);
1155         inc.inc_flags |= INC_ISIPV6;
1156         inc.inc6_faddr = *dst;
1157         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1158                 return;
1159
1160         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1161                 tcp_hc_updatemtu(&inc, mtu);
1162                 ICMP6STAT_INC(icp6s_pmtuchg);
1163         }
1164 }
1165
1166 /*
1167  * Process a Node Information Query packet, based on
1168  * draft-ietf-ipngwg-icmp-name-lookups-07.
1169  *
1170  * Spec incompatibilities:
1171  * - IPv6 Subject address handling
1172  * - IPv4 Subject address handling support missing
1173  * - Proxy reply (answer even if it's not for me)
1174  * - joins NI group address at in6_ifattach() time only, does not cope
1175  *   with hostname changes by sethostname(3)
1176  */
1177 static struct mbuf *
1178 ni6_input(struct mbuf *m, int off)
1179 {
1180         struct icmp6_nodeinfo *ni6, *nni6;
1181         struct mbuf *n = NULL;
1182         struct prison *pr;
1183         u_int16_t qtype;
1184         int subjlen;
1185         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1186         struct ni_reply_fqdn *fqdn;
1187         int addrs;              /* for NI_QTYPE_NODEADDR */
1188         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1189         struct in6_addr in6_subj; /* subject address */
1190         struct ip6_hdr *ip6;
1191         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1192         char *subj = NULL;
1193         struct in6_ifaddr *ia6 = NULL;
1194
1195         ip6 = mtod(m, struct ip6_hdr *);
1196 #ifndef PULLDOWN_TEST
1197         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1198 #else
1199         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1200         if (ni6 == NULL) {
1201                 /* m is already reclaimed */
1202                 return (NULL);
1203         }
1204 #endif
1205
1206         /*
1207          * Validate IPv6 source address.
1208          * The default configuration MUST be to refuse answering queries from
1209          * global-scope addresses according to RFC4602.
1210          * Notes:
1211          *  - it's not very clear what "refuse" means; this implementation
1212          *    simply drops it.
1213          *  - it's not very easy to identify global-scope (unicast) addresses
1214          *    since there are many prefixes for them.  It should be safer
1215          *    and in practice sufficient to check "all" but loopback and
1216          *    link-local (note that site-local unicast was deprecated and
1217          *    ULA is defined as global scope-wise)
1218          */
1219         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1220             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1221             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1222                 goto bad;
1223
1224         /*
1225          * Validate IPv6 destination address.
1226          *
1227          * The Responder must discard the Query without further processing
1228          * unless it is one of the Responder's unicast or anycast addresses, or
1229          * a link-local scope multicast address which the Responder has joined.
1230          * [RFC4602, Section 5.]
1231          */
1232         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1233                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1234                         goto bad;
1235                 /* else it's a link-local multicast, fine */
1236         } else {                /* unicast or anycast */
1237                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1238                 if (ia6 == NULL)
1239                         goto bad; /* XXX impossible */
1240
1241                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1242                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1243                         ifa_free(&ia6->ia_ifa);
1244                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1245                                 "a temporary address in %s:%d",
1246                                __FILE__, __LINE__));
1247                         goto bad;
1248                 }
1249                 ifa_free(&ia6->ia_ifa);
1250         }
1251
1252         /* validate query Subject field. */
1253         qtype = ntohs(ni6->ni_qtype);
1254         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1255         switch (qtype) {
1256         case NI_QTYPE_NOOP:
1257         case NI_QTYPE_SUPTYPES:
1258                 /* 07 draft */
1259                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1260                         break;
1261                 /* FALLTHROUGH */
1262         case NI_QTYPE_FQDN:
1263         case NI_QTYPE_NODEADDR:
1264         case NI_QTYPE_IPV4ADDR:
1265                 switch (ni6->ni_code) {
1266                 case ICMP6_NI_SUBJ_IPV6:
1267 #if ICMP6_NI_SUBJ_IPV6 != 0
1268                 case 0:
1269 #endif
1270                         /*
1271                          * backward compatibility - try to accept 03 draft
1272                          * format, where no Subject is present.
1273                          */
1274                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1275                             subjlen == 0) {
1276                                 oldfqdn++;
1277                                 break;
1278                         }
1279 #if ICMP6_NI_SUBJ_IPV6 != 0
1280                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1281                                 goto bad;
1282 #endif
1283
1284                         if (subjlen != sizeof(struct in6_addr))
1285                                 goto bad;
1286
1287                         /*
1288                          * Validate Subject address.
1289                          *
1290                          * Not sure what exactly "address belongs to the node"
1291                          * means in the spec, is it just unicast, or what?
1292                          *
1293                          * At this moment we consider Subject address as
1294                          * "belong to the node" if the Subject address equals
1295                          * to the IPv6 destination address; validation for
1296                          * IPv6 destination address should have done enough
1297                          * check for us.
1298                          *
1299                          * We do not do proxy at this moment.
1300                          */
1301                         /* m_pulldown instead of copy? */
1302                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1303                             subjlen, (caddr_t)&in6_subj);
1304                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1305                                 goto bad;
1306
1307                         subj = (char *)&in6_subj;
1308                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1309                                 break;
1310
1311                         /*
1312                          * XXX if we are to allow other cases, we should really
1313                          * be careful about scope here.
1314                          * basically, we should disallow queries toward IPv6
1315                          * destination X with subject Y,
1316                          * if scope(X) > scope(Y).
1317                          * if we allow scope(X) > scope(Y), it will result in
1318                          * information leakage across scope boundary.
1319                          */
1320                         goto bad;
1321
1322                 case ICMP6_NI_SUBJ_FQDN:
1323                         /*
1324                          * Validate Subject name with gethostname(3).
1325                          *
1326                          * The behavior may need some debate, since:
1327                          * - we are not sure if the node has FQDN as
1328                          *   hostname (returned by gethostname(3)).
1329                          * - the code does wildcard match for truncated names.
1330                          *   however, we are not sure if we want to perform
1331                          *   wildcard match, if gethostname(3) side has
1332                          *   truncated hostname.
1333                          */
1334                         pr = curthread->td_ucred->cr_prison;
1335                         mtx_lock(&pr->pr_mtx);
1336                         n = ni6_nametodns(pr->pr_hostname,
1337                             strlen(pr->pr_hostname), 0);
1338                         mtx_unlock(&pr->pr_mtx);
1339                         if (!n || n->m_next || n->m_len == 0)
1340                                 goto bad;
1341                         IP6_EXTHDR_GET(subj, char *, m,
1342                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1343                         if (subj == NULL)
1344                                 goto bad;
1345                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1346                             n->m_len)) {
1347                                 goto bad;
1348                         }
1349                         m_freem(n);
1350                         n = NULL;
1351                         break;
1352
1353                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1354                 default:
1355                         goto bad;
1356                 }
1357                 break;
1358         }
1359
1360         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1361         switch (qtype) {
1362         case NI_QTYPE_FQDN:
1363                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1364                         goto bad;
1365                 break;
1366         case NI_QTYPE_NODEADDR:
1367         case NI_QTYPE_IPV4ADDR:
1368                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1369                         goto bad;
1370                 break;
1371         }
1372
1373         /* guess reply length */
1374         switch (qtype) {
1375         case NI_QTYPE_NOOP:
1376                 break;          /* no reply data */
1377         case NI_QTYPE_SUPTYPES:
1378                 replylen += sizeof(u_int32_t);
1379                 break;
1380         case NI_QTYPE_FQDN:
1381                 /* XXX will append an mbuf */
1382                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1383                 break;
1384         case NI_QTYPE_NODEADDR:
1385                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1386                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1387                     sizeof(u_int32_t))) > MCLBYTES)
1388                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1389                 break;
1390         case NI_QTYPE_IPV4ADDR:
1391                 /* unsupported - should respond with unknown Qtype? */
1392                 break;
1393         default:
1394                 /*
1395                  * XXX: We must return a reply with the ICMP6 code
1396                  * `unknown Qtype' in this case.  However we regard the case
1397                  * as an FQDN query for backward compatibility.
1398                  * Older versions set a random value to this field,
1399                  * so it rarely varies in the defined qtypes.
1400                  * But the mechanism is not reliable...
1401                  * maybe we should obsolete older versions.
1402                  */
1403                 qtype = NI_QTYPE_FQDN;
1404                 /* XXX will append an mbuf */
1405                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1406                 oldfqdn++;
1407                 break;
1408         }
1409
1410         /* Allocate an mbuf to reply. */
1411         if (replylen > MCLBYTES) {
1412                 /*
1413                  * XXX: should we try to allocate more? But MCLBYTES
1414                  * is probably much larger than IPV6_MMTU...
1415                  */
1416                 goto bad;
1417         }
1418         if (replylen > MHLEN)
1419                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1420         else
1421                 n = m_gethdr(M_NOWAIT, m->m_type);
1422         if (n == NULL) {
1423                 m_freem(m);
1424                 return (NULL);
1425         }
1426         m_move_pkthdr(n, m); /* just for recvif and FIB */
1427         n->m_pkthdr.len = n->m_len = replylen;
1428
1429         /* copy mbuf header and IPv6 + Node Information base headers */
1430         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1431         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1432         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1433
1434         /* qtype dependent procedure */
1435         switch (qtype) {
1436         case NI_QTYPE_NOOP:
1437                 nni6->ni_code = ICMP6_NI_SUCCESS;
1438                 nni6->ni_flags = 0;
1439                 break;
1440         case NI_QTYPE_SUPTYPES:
1441         {
1442                 u_int32_t v;
1443                 nni6->ni_code = ICMP6_NI_SUCCESS;
1444                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1445                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1446                 v = (u_int32_t)htonl(0x0000000f);
1447                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1448                 break;
1449         }
1450         case NI_QTYPE_FQDN:
1451                 nni6->ni_code = ICMP6_NI_SUCCESS;
1452                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1453                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1454                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1455                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1456                 /*
1457                  * XXX do we really have FQDN in hostname?
1458                  */
1459                 pr = curthread->td_ucred->cr_prison;
1460                 mtx_lock(&pr->pr_mtx);
1461                 n->m_next = ni6_nametodns(pr->pr_hostname,
1462                     strlen(pr->pr_hostname), oldfqdn);
1463                 mtx_unlock(&pr->pr_mtx);
1464                 if (n->m_next == NULL)
1465                         goto bad;
1466                 /* XXX we assume that n->m_next is not a chain */
1467                 if (n->m_next->m_next != NULL)
1468                         goto bad;
1469                 n->m_pkthdr.len += n->m_next->m_len;
1470                 break;
1471         case NI_QTYPE_NODEADDR:
1472         {
1473                 int lenlim, copied;
1474
1475                 nni6->ni_code = ICMP6_NI_SUCCESS;
1476                 n->m_pkthdr.len = n->m_len =
1477                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1478                 lenlim = M_TRAILINGSPACE(n);
1479                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1480                 /* XXX: reset mbuf length */
1481                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1482                     sizeof(struct icmp6_nodeinfo) + copied;
1483                 break;
1484         }
1485         default:
1486                 break;          /* XXX impossible! */
1487         }
1488
1489         nni6->ni_type = ICMP6_NI_REPLY;
1490         m_freem(m);
1491         return (n);
1492
1493   bad:
1494         m_freem(m);
1495         if (n)
1496                 m_freem(n);
1497         return (NULL);
1498 }
1499
1500 /*
1501  * make a mbuf with DNS-encoded string.  no compression support.
1502  *
1503  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1504  * treated as truncated name (two \0 at the end).  this is a wild guess.
1505  *
1506  * old - return pascal string if non-zero
1507  */
1508 static struct mbuf *
1509 ni6_nametodns(const char *name, int namelen, int old)
1510 {
1511         struct mbuf *m;
1512         char *cp, *ep;
1513         const char *p, *q;
1514         int i, len, nterm;
1515
1516         if (old)
1517                 len = namelen + 1;
1518         else
1519                 len = MCLBYTES;
1520
1521         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1522         if (len > MLEN)
1523                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1524         else
1525                 m = m_get(M_NOWAIT, MT_DATA);
1526         if (m == NULL)
1527                 goto fail;
1528
1529         if (old) {
1530                 m->m_len = len;
1531                 *mtod(m, char *) = namelen;
1532                 bcopy(name, mtod(m, char *) + 1, namelen);
1533                 return m;
1534         } else {
1535                 m->m_len = 0;
1536                 cp = mtod(m, char *);
1537                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1538
1539                 /* if not certain about my name, return empty buffer */
1540                 if (namelen == 0)
1541                         return m;
1542
1543                 /*
1544                  * guess if it looks like shortened hostname, or FQDN.
1545                  * shortened hostname needs two trailing "\0".
1546                  */
1547                 i = 0;
1548                 for (p = name; p < name + namelen; p++) {
1549                         if (*p && *p == '.')
1550                                 i++;
1551                 }
1552                 if (i < 2)
1553                         nterm = 2;
1554                 else
1555                         nterm = 1;
1556
1557                 p = name;
1558                 while (cp < ep && p < name + namelen) {
1559                         i = 0;
1560                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1561                                 i++;
1562                         /* result does not fit into mbuf */
1563                         if (cp + i + 1 >= ep)
1564                                 goto fail;
1565                         /*
1566                          * DNS label length restriction, RFC1035 page 8.
1567                          * "i == 0" case is included here to avoid returning
1568                          * 0-length label on "foo..bar".
1569                          */
1570                         if (i <= 0 || i >= 64)
1571                                 goto fail;
1572                         *cp++ = i;
1573                         bcopy(p, cp, i);
1574                         cp += i;
1575                         p = q;
1576                         if (p < name + namelen && *p == '.')
1577                                 p++;
1578                 }
1579                 /* termination */
1580                 if (cp + nterm >= ep)
1581                         goto fail;
1582                 while (nterm-- > 0)
1583                         *cp++ = '\0';
1584                 m->m_len = cp - mtod(m, char *);
1585                 return m;
1586         }
1587
1588         panic("should not reach here");
1589         /* NOTREACHED */
1590
1591  fail:
1592         if (m)
1593                 m_freem(m);
1594         return NULL;
1595 }
1596
1597 /*
1598  * check if two DNS-encoded string matches.  takes care of truncated
1599  * form (with \0\0 at the end).  no compression support.
1600  * XXX upper/lowercase match (see RFC2065)
1601  */
1602 static int
1603 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1604 {
1605         const char *a0, *b0;
1606         int l;
1607
1608         /* simplest case - need validation? */
1609         if (alen == blen && bcmp(a, b, alen) == 0)
1610                 return 1;
1611
1612         a0 = a;
1613         b0 = b;
1614
1615         /* termination is mandatory */
1616         if (alen < 2 || blen < 2)
1617                 return 0;
1618         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1619                 return 0;
1620         alen--;
1621         blen--;
1622
1623         while (a - a0 < alen && b - b0 < blen) {
1624                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1625                         return 0;
1626
1627                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1628                         return 0;
1629                 /* we don't support compression yet */
1630                 if (a[0] >= 64 || b[0] >= 64)
1631                         return 0;
1632
1633                 /* truncated case */
1634                 if (a[0] == 0 && a - a0 == alen - 1)
1635                         return 1;
1636                 if (b[0] == 0 && b - b0 == blen - 1)
1637                         return 1;
1638                 if (a[0] == 0 || b[0] == 0)
1639                         return 0;
1640
1641                 if (a[0] != b[0])
1642                         return 0;
1643                 l = a[0];
1644                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1645                         return 0;
1646                 if (bcmp(a + 1, b + 1, l) != 0)
1647                         return 0;
1648
1649                 a += 1 + l;
1650                 b += 1 + l;
1651         }
1652
1653         if (a - a0 == alen && b - b0 == blen)
1654                 return 1;
1655         else
1656                 return 0;
1657 }
1658
1659 /*
1660  * calculate the number of addresses to be returned in the node info reply.
1661  */
1662 static int
1663 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1664     struct in6_addr *subj)
1665 {
1666         struct ifnet *ifp;
1667         struct in6_ifaddr *ifa6;
1668         struct ifaddr *ifa;
1669         int addrs = 0, addrsofif, iffound = 0;
1670         int niflags = ni6->ni_flags;
1671
1672         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1673                 switch (ni6->ni_code) {
1674                 case ICMP6_NI_SUBJ_IPV6:
1675                         if (subj == NULL) /* must be impossible... */
1676                                 return (0);
1677                         break;
1678                 default:
1679                         /*
1680                          * XXX: we only support IPv6 subject address for
1681                          * this Qtype.
1682                          */
1683                         return (0);
1684                 }
1685         }
1686
1687         IFNET_RLOCK_NOSLEEP();
1688         TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1689                 addrsofif = 0;
1690                 IF_ADDR_RLOCK(ifp);
1691                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1692                         if (ifa->ifa_addr->sa_family != AF_INET6)
1693                                 continue;
1694                         ifa6 = (struct in6_ifaddr *)ifa;
1695
1696                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1697                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1698                                 iffound = 1;
1699
1700                         /*
1701                          * IPv4-mapped addresses can only be returned by a
1702                          * Node Information proxy, since they represent
1703                          * addresses of IPv4-only nodes, which perforce do
1704                          * not implement this protocol.
1705                          * [icmp-name-lookups-07, Section 5.4]
1706                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1707                          * this function at this moment.
1708                          */
1709
1710                         /* What do we have to do about ::1? */
1711                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1712                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1713                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1714                                         continue;
1715                                 break;
1716                         case IPV6_ADDR_SCOPE_SITELOCAL:
1717                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1718                                         continue;
1719                                 break;
1720                         case IPV6_ADDR_SCOPE_GLOBAL:
1721                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1722                                         continue;
1723                                 break;
1724                         default:
1725                                 continue;
1726                         }
1727
1728                         /*
1729                          * check if anycast is okay.
1730                          * XXX: just experimental.  not in the spec.
1731                          */
1732                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1733                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1734                                 continue; /* we need only unicast addresses */
1735                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1736                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1737                                 continue;
1738                         }
1739                         addrsofif++; /* count the address */
1740                 }
1741                 IF_ADDR_RUNLOCK(ifp);
1742                 if (iffound) {
1743                         *ifpp = ifp;
1744                         IFNET_RUNLOCK_NOSLEEP();
1745                         return (addrsofif);
1746                 }
1747
1748                 addrs += addrsofif;
1749         }
1750         IFNET_RUNLOCK_NOSLEEP();
1751
1752         return (addrs);
1753 }
1754
1755 static int
1756 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1757     struct ifnet *ifp0, int resid)
1758 {
1759         struct ifnet *ifp;
1760         struct in6_ifaddr *ifa6;
1761         struct ifaddr *ifa;
1762         struct ifnet *ifp_dep = NULL;
1763         int copied = 0, allow_deprecated = 0;
1764         u_char *cp = (u_char *)(nni6 + 1);
1765         int niflags = ni6->ni_flags;
1766         u_int32_t ltime;
1767
1768         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1769                 return (0);     /* needless to copy */
1770
1771         IFNET_RLOCK_NOSLEEP();
1772         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1773   again:
1774
1775         for (; ifp; ifp = TAILQ_NEXT(ifp, if_link)) {
1776                 IF_ADDR_RLOCK(ifp);
1777                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1778                         if (ifa->ifa_addr->sa_family != AF_INET6)
1779                                 continue;
1780                         ifa6 = (struct in6_ifaddr *)ifa;
1781
1782                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1783                             allow_deprecated == 0) {
1784                                 /*
1785                                  * prefererred address should be put before
1786                                  * deprecated addresses.
1787                                  */
1788
1789                                 /* record the interface for later search */
1790                                 if (ifp_dep == NULL)
1791                                         ifp_dep = ifp;
1792
1793                                 continue;
1794                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1795                             allow_deprecated != 0)
1796                                 continue; /* we now collect deprecated addrs */
1797
1798                         /* What do we have to do about ::1? */
1799                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1800                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1801                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1802                                         continue;
1803                                 break;
1804                         case IPV6_ADDR_SCOPE_SITELOCAL:
1805                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1806                                         continue;
1807                                 break;
1808                         case IPV6_ADDR_SCOPE_GLOBAL:
1809                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1810                                         continue;
1811                                 break;
1812                         default:
1813                                 continue;
1814                         }
1815
1816                         /*
1817                          * check if anycast is okay.
1818                          * XXX: just experimental.  not in the spec.
1819                          */
1820                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1821                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1822                                 continue;
1823                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1824                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1825                                 continue;
1826                         }
1827
1828                         /* now we can copy the address */
1829                         if (resid < sizeof(struct in6_addr) +
1830                             sizeof(u_int32_t)) {
1831                                 IF_ADDR_RUNLOCK(ifp);
1832                                 /*
1833                                  * We give up much more copy.
1834                                  * Set the truncate flag and return.
1835                                  */
1836                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1837                                 IFNET_RUNLOCK_NOSLEEP();
1838                                 return (copied);
1839                         }
1840
1841                         /*
1842                          * Set the TTL of the address.
1843                          * The TTL value should be one of the following
1844                          * according to the specification:
1845                          *
1846                          * 1. The remaining lifetime of a DHCP lease on the
1847                          *    address, or
1848                          * 2. The remaining Valid Lifetime of a prefix from
1849                          *    which the address was derived through Stateless
1850                          *    Autoconfiguration.
1851                          *
1852                          * Note that we currently do not support stateful
1853                          * address configuration by DHCPv6, so the former
1854                          * case can't happen.
1855                          */
1856                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1857                                 ltime = ND6_INFINITE_LIFETIME;
1858                         else {
1859                                 if (ifa6->ia6_lifetime.ia6t_expire >
1860                                     time_uptime)
1861                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1862                                 else
1863                                         ltime = 0;
1864                         }
1865
1866                         bcopy(&ltime, cp, sizeof(u_int32_t));
1867                         cp += sizeof(u_int32_t);
1868
1869                         /* copy the address itself */
1870                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1871                             sizeof(struct in6_addr));
1872                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1873                         cp += sizeof(struct in6_addr);
1874
1875                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1876                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1877                 }
1878                 IF_ADDR_RUNLOCK(ifp);
1879                 if (ifp0)       /* we need search only on the specified IF */
1880                         break;
1881         }
1882
1883         if (allow_deprecated == 0 && ifp_dep != NULL) {
1884                 ifp = ifp_dep;
1885                 allow_deprecated = 1;
1886
1887                 goto again;
1888         }
1889
1890         IFNET_RUNLOCK_NOSLEEP();
1891
1892         return (copied);
1893 }
1894
1895 /*
1896  * XXX almost dup'ed code with rip6_input.
1897  */
1898 static int
1899 icmp6_rip6_input(struct mbuf **mp, int off)
1900 {
1901         struct mbuf *m = *mp;
1902         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1903         struct inpcb *in6p;
1904         struct inpcb *last = NULL;
1905         struct sockaddr_in6 fromsa;
1906         struct icmp6_hdr *icmp6;
1907         struct mbuf *opts = NULL;
1908
1909 #ifndef PULLDOWN_TEST
1910         /* this is assumed to be safe. */
1911         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1912 #else
1913         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1914         if (icmp6 == NULL) {
1915                 /* m is already reclaimed */
1916                 return (IPPROTO_DONE);
1917         }
1918 #endif
1919
1920         /*
1921          * XXX: the address may have embedded scope zone ID, which should be
1922          * hidden from applications.
1923          */
1924         bzero(&fromsa, sizeof(fromsa));
1925         fromsa.sin6_family = AF_INET6;
1926         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1927         fromsa.sin6_addr = ip6->ip6_src;
1928         if (sa6_recoverscope(&fromsa)) {
1929                 m_freem(m);
1930                 return (IPPROTO_DONE);
1931         }
1932
1933         INP_INFO_RLOCK(&V_ripcbinfo);
1934         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1935                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1936                         continue;
1937                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1938                         continue;
1939                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1940                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1941                         continue;
1942                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1943                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1944                         continue;
1945                 INP_RLOCK(in6p);
1946                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1947                     in6p->in6p_icmp6filt)) {
1948                         INP_RUNLOCK(in6p);
1949                         continue;
1950                 }
1951                 if (last != NULL) {
1952                         struct  mbuf *n = NULL;
1953
1954                         /*
1955                          * Recent network drivers tend to allocate a single
1956                          * mbuf cluster, rather than to make a couple of
1957                          * mbufs without clusters.  Also, since the IPv6 code
1958                          * path tries to avoid m_pullup(), it is highly
1959                          * probable that we still have an mbuf cluster here
1960                          * even though the necessary length can be stored in an
1961                          * mbuf's internal buffer.
1962                          * Meanwhile, the default size of the receive socket
1963                          * buffer for raw sockets is not so large.  This means
1964                          * the possibility of packet loss is relatively higher
1965                          * than before.  To avoid this scenario, we copy the
1966                          * received data to a separate mbuf that does not use
1967                          * a cluster, if possible.
1968                          * XXX: it is better to copy the data after stripping
1969                          * intermediate headers.
1970                          */
1971                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1972                             m->m_len <= MHLEN) {
1973                                 n = m_get(M_NOWAIT, m->m_type);
1974                                 if (n != NULL) {
1975                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1976                                                 bcopy(m->m_data, n->m_data,
1977                                                       m->m_len);
1978                                                 n->m_len = m->m_len;
1979                                         } else {
1980                                                 m_free(n);
1981                                                 n = NULL;
1982                                         }
1983                                 }
1984                         }
1985                         if (n != NULL ||
1986                             (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
1987                                 if (last->inp_flags & INP_CONTROLOPTS)
1988                                         ip6_savecontrol(last, n, &opts);
1989                                 /* strip intermediate headers */
1990                                 m_adj(n, off);
1991                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
1992                                 if (sbappendaddr_locked(
1993                                     &last->inp_socket->so_rcv,
1994                                     (struct sockaddr *)&fromsa, n, opts)
1995                                     == 0) {
1996                                         /* should notify about lost packet */
1997                                         m_freem(n);
1998                                         if (opts) {
1999                                                 m_freem(opts);
2000                                         }
2001                                         SOCKBUF_UNLOCK(
2002                                             &last->inp_socket->so_rcv);
2003                                 } else
2004                                         sorwakeup_locked(last->inp_socket);
2005                                 opts = NULL;
2006                         }
2007                         INP_RUNLOCK(last);
2008                 }
2009                 last = in6p;
2010         }
2011         INP_INFO_RUNLOCK(&V_ripcbinfo);
2012         if (last != NULL) {
2013                 if (last->inp_flags & INP_CONTROLOPTS)
2014                         ip6_savecontrol(last, m, &opts);
2015                 /* strip intermediate headers */
2016                 m_adj(m, off);
2017
2018                 /* avoid using mbuf clusters if possible (see above) */
2019                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2020                     m->m_len <= MHLEN) {
2021                         struct mbuf *n;
2022
2023                         n = m_get(M_NOWAIT, m->m_type);
2024                         if (n != NULL) {
2025                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2026                                         bcopy(m->m_data, n->m_data, m->m_len);
2027                                         n->m_len = m->m_len;
2028
2029                                         m_freem(m);
2030                                         m = n;
2031                                 } else {
2032                                         m_freem(n);
2033                                         n = NULL;
2034                                 }
2035                         }
2036                 }
2037                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2038                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2039                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2040                         m_freem(m);
2041                         if (opts)
2042                                 m_freem(opts);
2043                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2044                 } else
2045                         sorwakeup_locked(last->inp_socket);
2046                 INP_RUNLOCK(last);
2047         } else {
2048                 m_freem(m);
2049                 IP6STAT_DEC(ip6s_delivered);
2050         }
2051         return IPPROTO_DONE;
2052 }
2053
2054 /*
2055  * Reflect the ip6 packet back to the source.
2056  * OFF points to the icmp6 header, counted from the top of the mbuf.
2057  */
2058 void
2059 icmp6_reflect(struct mbuf *m, size_t off)
2060 {
2061         struct in6_addr src6, *srcp;
2062         struct ip6_hdr *ip6;
2063         struct icmp6_hdr *icmp6;
2064         struct in6_ifaddr *ia = NULL;
2065         struct ifnet *outif = NULL;
2066         int plen;
2067         int type, code, hlim;
2068
2069         /* too short to reflect */
2070         if (off < sizeof(struct ip6_hdr)) {
2071                 nd6log((LOG_DEBUG,
2072                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2073                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2074                     __FILE__, __LINE__));
2075                 goto bad;
2076         }
2077
2078         /*
2079          * If there are extra headers between IPv6 and ICMPv6, strip
2080          * off that header first.
2081          */
2082 #ifdef DIAGNOSTIC
2083         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2084                 panic("assumption failed in icmp6_reflect");
2085 #endif
2086         if (off > sizeof(struct ip6_hdr)) {
2087                 size_t l;
2088                 struct ip6_hdr nip6;
2089
2090                 l = off - sizeof(struct ip6_hdr);
2091                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2092                 m_adj(m, l);
2093                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2094                 if (m->m_len < l) {
2095                         if ((m = m_pullup(m, l)) == NULL)
2096                                 return;
2097                 }
2098                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2099         } else /* off == sizeof(struct ip6_hdr) */ {
2100                 size_t l;
2101                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2102                 if (m->m_len < l) {
2103                         if ((m = m_pullup(m, l)) == NULL)
2104                                 return;
2105                 }
2106         }
2107         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2108         ip6 = mtod(m, struct ip6_hdr *);
2109         ip6->ip6_nxt = IPPROTO_ICMPV6;
2110         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2111         type = icmp6->icmp6_type; /* keep type for statistics */
2112         code = icmp6->icmp6_code; /* ditto. */
2113         hlim = 0;
2114         srcp = NULL;
2115
2116         /*
2117          * If the incoming packet was addressed directly to us (i.e. unicast),
2118          * use dst as the src for the reply.
2119          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2120          * (for example) when we encounter an error while forwarding procedure
2121          * destined to a duplicated address of ours.
2122          */
2123         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2124                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2125                 if (ia != NULL && !(ia->ia6_flags &
2126                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2127                         src6 = ia->ia_addr.sin6_addr;
2128                         srcp = &src6;
2129
2130                         if (m->m_pkthdr.rcvif != NULL) {
2131                                 /* XXX: This may not be the outgoing interface */
2132                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2133                         } else
2134                                 hlim = V_ip6_defhlim;
2135                 }
2136                 if (ia != NULL)
2137                         ifa_free(&ia->ia_ifa);
2138         }
2139
2140         if (srcp == NULL) {
2141                 int error;
2142                 struct in6_addr dst6;
2143                 uint32_t scopeid;
2144
2145                 /*
2146                  * This case matches to multicasts, our anycast, or unicasts
2147                  * that we do not own.  Select a source address based on the
2148                  * source address of the erroneous packet.
2149                  */
2150                 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2151                 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2152                     scopeid, NULL, &src6, &hlim);
2153
2154                 if (error) {
2155                         char ip6buf[INET6_ADDRSTRLEN];
2156                         nd6log((LOG_DEBUG,
2157                             "icmp6_reflect: source can't be determined: "
2158                             "dst=%s, error=%d\n",
2159                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2160                         goto bad;
2161                 }
2162                 srcp = &src6;
2163         }
2164         /*
2165          * ip6_input() drops a packet if its src is multicast.
2166          * So, the src is never multicast.
2167          */
2168         ip6->ip6_dst = ip6->ip6_src;
2169         ip6->ip6_src = *srcp;
2170         ip6->ip6_flow = 0;
2171         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2172         ip6->ip6_vfc |= IPV6_VERSION;
2173         ip6->ip6_nxt = IPPROTO_ICMPV6;
2174         ip6->ip6_hlim = hlim;
2175
2176         icmp6->icmp6_cksum = 0;
2177         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2178             sizeof(struct ip6_hdr), plen);
2179
2180         /*
2181          * XXX option handling
2182          */
2183
2184         m->m_flags &= ~(M_BCAST|M_MCAST);
2185
2186         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2187         if (outif)
2188                 icmp6_ifoutstat_inc(outif, type, code);
2189
2190         return;
2191
2192  bad:
2193         m_freem(m);
2194         return;
2195 }
2196
2197 void
2198 icmp6_fasttimo(void)
2199 {
2200
2201         mld_fasttimo();
2202 }
2203
2204 void
2205 icmp6_slowtimo(void)
2206 {
2207
2208         mld_slowtimo();
2209 }
2210
2211 static const char *
2212 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2213     struct in6_addr *tgt6)
2214 {
2215         static char buf[1024];
2216         char ip6bufs[INET6_ADDRSTRLEN];
2217         char ip6bufd[INET6_ADDRSTRLEN];
2218         char ip6buft[INET6_ADDRSTRLEN];
2219         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2220             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2221             ip6_sprintf(ip6buft, tgt6));
2222         return buf;
2223 }
2224
2225 void
2226 icmp6_redirect_input(struct mbuf *m, int off)
2227 {
2228         struct ifnet *ifp;
2229         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2230         struct nd_redirect *nd_rd;
2231         int icmp6len = ntohs(ip6->ip6_plen);
2232         char *lladdr = NULL;
2233         int lladdrlen = 0;
2234         int is_router;
2235         int is_onlink;
2236         struct in6_addr src6 = ip6->ip6_src;
2237         struct in6_addr redtgt6;
2238         struct in6_addr reddst6;
2239         union nd_opts ndopts;
2240         char ip6buf[INET6_ADDRSTRLEN];
2241
2242         M_ASSERTPKTHDR(m);
2243         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2244
2245         ifp = m->m_pkthdr.rcvif;
2246
2247         /* XXX if we are router, we don't update route by icmp6 redirect */
2248         if (V_ip6_forwarding)
2249                 goto freeit;
2250         if (!V_icmp6_rediraccept)
2251                 goto freeit;
2252
2253 #ifndef PULLDOWN_TEST
2254         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2255         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2256 #else
2257         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2258         if (nd_rd == NULL) {
2259                 ICMP6STAT_INC(icp6s_tooshort);
2260                 return;
2261         }
2262 #endif
2263         redtgt6 = nd_rd->nd_rd_target;
2264         reddst6 = nd_rd->nd_rd_dst;
2265
2266         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2267             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2268                 goto freeit;
2269         }
2270
2271         /* validation */
2272         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2273                 nd6log((LOG_ERR,
2274                     "ICMP6 redirect sent from %s rejected; "
2275                     "must be from linklocal\n",
2276                     ip6_sprintf(ip6buf, &src6)));
2277                 goto bad;
2278         }
2279         if (ip6->ip6_hlim != 255) {
2280                 nd6log((LOG_ERR,
2281                     "ICMP6 redirect sent from %s rejected; "
2282                     "hlim=%d (must be 255)\n",
2283                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2284                 goto bad;
2285         }
2286     {
2287         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2288         struct nhop6_basic nh6;
2289         struct in6_addr kdst;
2290         uint32_t scopeid;
2291
2292         in6_splitscope(&reddst6, &kdst, &scopeid);
2293         if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){
2294                 if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
2295                         nd6log((LOG_ERR,
2296                             "ICMP6 redirect rejected; no route "
2297                             "with inet6 gateway found for redirect dst: %s\n",
2298                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2299                         goto bad;
2300                 }
2301
2302                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
2303                         nd6log((LOG_ERR,
2304                             "ICMP6 redirect rejected; "
2305                             "not equal to gw-for-src=%s (must be same): "
2306                             "%s\n",
2307                             ip6_sprintf(ip6buf, &nh6.nh_addr),
2308                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2309                         goto bad;
2310                 }
2311         } else {
2312                 nd6log((LOG_ERR,
2313                     "ICMP6 redirect rejected; "
2314                     "no route found for redirect dst: %s\n",
2315                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2316                 goto bad;
2317         }
2318     }
2319         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2320                 nd6log((LOG_ERR,
2321                     "ICMP6 redirect rejected; "
2322                     "redirect dst must be unicast: %s\n",
2323                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2324                 goto bad;
2325         }
2326
2327         is_router = is_onlink = 0;
2328         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2329                 is_router = 1;  /* router case */
2330         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2331                 is_onlink = 1;  /* on-link destination case */
2332         if (!is_router && !is_onlink) {
2333                 nd6log((LOG_ERR,
2334                     "ICMP6 redirect rejected; "
2335                     "neither router case nor onlink case: %s\n",
2336                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2337                 goto bad;
2338         }
2339
2340         icmp6len -= sizeof(*nd_rd);
2341         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2342         if (nd6_options(&ndopts) < 0) {
2343                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2344                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2345                 /* nd6_options have incremented stats */
2346                 goto freeit;
2347         }
2348
2349         if (ndopts.nd_opts_tgt_lladdr) {
2350                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2351                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2352         }
2353
2354         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2355                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2356                     "(if %d, icmp6 packet %d): %s\n",
2357                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2358                     ifp->if_addrlen, lladdrlen - 2,
2359                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2360                 goto bad;
2361         }
2362
2363         /* Validation passed. */
2364
2365         /* RFC 2461 8.3 */
2366         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2367             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2368
2369         /*
2370          * Install a gateway route in the better-router case or an interface
2371          * route in the on-link-destination case.
2372          */
2373         {
2374                 struct sockaddr_in6 sdst;
2375                 struct sockaddr_in6 sgw;
2376                 struct sockaddr_in6 ssrc;
2377                 struct sockaddr *gw;
2378                 int rt_flags;
2379                 u_int fibnum;
2380
2381                 bzero(&sdst, sizeof(sdst));
2382                 bzero(&ssrc, sizeof(ssrc));
2383                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2384                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2385                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2386                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2387                 rt_flags = RTF_HOST;
2388                 if (is_router) {
2389                         bzero(&sgw, sizeof(sgw));
2390                         sgw.sin6_family = AF_INET6;
2391                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2392                         bcopy(&redtgt6, &sgw.sin6_addr,
2393                                 sizeof(struct in6_addr));
2394                         gw = (struct sockaddr *)&sgw;
2395                         rt_flags |= RTF_GATEWAY;
2396                 } else
2397                         gw = ifp->if_addr->ifa_addr;
2398                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2399                         in6_rtredirect((struct sockaddr *)&sdst, gw,
2400                             (struct sockaddr *)NULL, rt_flags,
2401                             (struct sockaddr *)&ssrc, fibnum);
2402         }
2403         /* finally update cached route in each socket via pfctlinput */
2404     {
2405         struct sockaddr_in6 sdst;
2406
2407         bzero(&sdst, sizeof(sdst));
2408         sdst.sin6_family = AF_INET6;
2409         sdst.sin6_len = sizeof(struct sockaddr_in6);
2410         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2411         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2412     }
2413
2414  freeit:
2415         m_freem(m);
2416         return;
2417
2418  bad:
2419         ICMP6STAT_INC(icp6s_badredirect);
2420         m_freem(m);
2421 }
2422
2423 void
2424 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2425 {
2426         struct ifnet *ifp;      /* my outgoing interface */
2427         struct in6_addr *ifp_ll6;
2428         struct in6_addr *router_ll6;
2429         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2430         struct mbuf *m = NULL;  /* newly allocated one */
2431         struct m_tag *mtag;
2432         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2433         struct nd_redirect *nd_rd;
2434         struct llentry *ln = NULL;
2435         size_t maxlen;
2436         u_char *p;
2437         struct ifnet *outif = NULL;
2438         struct sockaddr_in6 src_sa;
2439
2440         icmp6_errcount(ND_REDIRECT, 0);
2441
2442         /* if we are not router, we don't send icmp6 redirect */
2443         if (!V_ip6_forwarding)
2444                 goto fail;
2445
2446         /* sanity check */
2447         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2448                 goto fail;
2449
2450         /*
2451          * Address check:
2452          *  the source address must identify a neighbor, and
2453          *  the destination address must not be a multicast address
2454          *  [RFC 2461, sec 8.2]
2455          */
2456         sip6 = mtod(m0, struct ip6_hdr *);
2457         bzero(&src_sa, sizeof(src_sa));
2458         src_sa.sin6_family = AF_INET6;
2459         src_sa.sin6_len = sizeof(src_sa);
2460         src_sa.sin6_addr = sip6->ip6_src;
2461         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2462                 goto fail;
2463         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2464                 goto fail;      /* what should we do here? */
2465
2466         /* rate limit */
2467         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2468                 goto fail;
2469
2470         /*
2471          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2472          * we almost always ask for an mbuf cluster for simplicity.
2473          * (MHLEN < IPV6_MMTU is almost always true)
2474          */
2475 #if IPV6_MMTU >= MCLBYTES
2476 # error assumption failed about IPV6_MMTU and MCLBYTES
2477 #endif
2478         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2479         if (m == NULL)
2480                 goto fail;
2481         M_SETFIB(m, rt->rt_fibnum);
2482         maxlen = M_TRAILINGSPACE(m);
2483         maxlen = min(IPV6_MMTU, maxlen);
2484         /* just for safety */
2485         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2486             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2487                 goto fail;
2488         }
2489
2490         {
2491                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2492                 struct in6_ifaddr *ia;
2493                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2494                                                  IN6_IFF_NOTREADY|
2495                                                  IN6_IFF_ANYCAST)) == NULL)
2496                         goto fail;
2497                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2498                 /* XXXRW: reference released prematurely. */
2499                 ifa_free(&ia->ia_ifa);
2500         }
2501
2502         /* get ip6 linklocal address for the router. */
2503         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2504                 struct sockaddr_in6 *sin6;
2505                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2506                 router_ll6 = &sin6->sin6_addr;
2507                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2508                         router_ll6 = (struct in6_addr *)NULL;
2509         } else
2510                 router_ll6 = (struct in6_addr *)NULL;
2511
2512         /* ip6 */
2513         ip6 = mtod(m, struct ip6_hdr *);
2514         ip6->ip6_flow = 0;
2515         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2516         ip6->ip6_vfc |= IPV6_VERSION;
2517         /* ip6->ip6_plen will be set later */
2518         ip6->ip6_nxt = IPPROTO_ICMPV6;
2519         ip6->ip6_hlim = 255;
2520         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2521         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2522         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2523
2524         /* ND Redirect */
2525         nd_rd = (struct nd_redirect *)(ip6 + 1);
2526         nd_rd->nd_rd_type = ND_REDIRECT;
2527         nd_rd->nd_rd_code = 0;
2528         nd_rd->nd_rd_reserved = 0;
2529         if (rt->rt_flags & RTF_GATEWAY) {
2530                 /*
2531                  * nd_rd->nd_rd_target must be a link-local address in
2532                  * better router cases.
2533                  */
2534                 if (!router_ll6)
2535                         goto fail;
2536                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2537                     sizeof(nd_rd->nd_rd_target));
2538                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2539                     sizeof(nd_rd->nd_rd_dst));
2540         } else {
2541                 /* make sure redtgt == reddst */
2542                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2543                     sizeof(nd_rd->nd_rd_target));
2544                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2545                     sizeof(nd_rd->nd_rd_dst));
2546         }
2547
2548         p = (u_char *)(nd_rd + 1);
2549
2550         if (!router_ll6)
2551                 goto nolladdropt;
2552
2553         {
2554                 /* target lladdr option */
2555                 int len;
2556                 struct nd_opt_hdr *nd_opt;
2557                 char *lladdr;
2558
2559                 IF_AFDATA_RLOCK(ifp);
2560                 ln = nd6_lookup(router_ll6, 0, ifp);
2561                 IF_AFDATA_RUNLOCK(ifp);
2562                 if (ln == NULL)
2563                         goto nolladdropt;
2564
2565                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2566                 len = (len + 7) & ~7;   /* round by 8 */
2567                 /* safety check */
2568                 if (len + (p - (u_char *)ip6) > maxlen)
2569                         goto nolladdropt;
2570
2571                 if (ln->la_flags & LLE_VALID) {
2572                         nd_opt = (struct nd_opt_hdr *)p;
2573                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2574                         nd_opt->nd_opt_len = len >> 3;
2575                         lladdr = (char *)(nd_opt + 1);
2576                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2577                         p += len;
2578                 }
2579         }
2580 nolladdropt:
2581         if (ln != NULL)
2582                 LLE_RUNLOCK(ln);
2583
2584         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2585
2586         /* just to be safe */
2587 #ifdef M_DECRYPTED      /*not openbsd*/
2588         if (m0->m_flags & M_DECRYPTED)
2589                 goto noredhdropt;
2590 #endif
2591         if (p - (u_char *)ip6 > maxlen)
2592                 goto noredhdropt;
2593
2594         {
2595                 /* redirected header option */
2596                 int len;
2597                 struct nd_opt_rd_hdr *nd_opt_rh;
2598
2599                 /*
2600                  * compute the maximum size for icmp6 redirect header option.
2601                  * XXX room for auth header?
2602                  */
2603                 len = maxlen - (p - (u_char *)ip6);
2604                 len &= ~7;
2605
2606                 /* This is just for simplicity. */
2607                 if (m0->m_pkthdr.len != m0->m_len) {
2608                         if (m0->m_next) {
2609                                 m_freem(m0->m_next);
2610                                 m0->m_next = NULL;
2611                         }
2612                         m0->m_pkthdr.len = m0->m_len;
2613                 }
2614
2615                 /*
2616                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2617                  * about padding/truncate rule for the original IP packet.
2618                  * From the discussion on IPv6imp in Feb 1999,
2619                  * the consensus was:
2620                  * - "attach as much as possible" is the goal
2621                  * - pad if not aligned (original size can be guessed by
2622                  *   original ip6 header)
2623                  * Following code adds the padding if it is simple enough,
2624                  * and truncates if not.
2625                  */
2626                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2627                         panic("assumption failed in %s:%d", __FILE__,
2628                             __LINE__);
2629
2630                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2631                         /* not enough room, truncate */
2632                         m0->m_pkthdr.len = m0->m_len = len -
2633                             sizeof(*nd_opt_rh);
2634                 } else {
2635                         /* enough room, pad or truncate */
2636                         size_t extra;
2637
2638                         extra = m0->m_pkthdr.len % 8;
2639                         if (extra) {
2640                                 /* pad if easy enough, truncate if not */
2641                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2642                                         /* pad */
2643                                         m0->m_len += (8 - extra);
2644                                         m0->m_pkthdr.len += (8 - extra);
2645                                 } else {
2646                                         /* truncate */
2647                                         m0->m_pkthdr.len -= extra;
2648                                         m0->m_len -= extra;
2649                                 }
2650                         }
2651                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2652                         m0->m_pkthdr.len = m0->m_len = len -
2653                             sizeof(*nd_opt_rh);
2654                 }
2655
2656                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2657                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2658                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2659                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2660                 p += sizeof(*nd_opt_rh);
2661                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2662
2663                 /* connect m0 to m */
2664                 m_tag_delete_chain(m0, NULL);
2665                 m0->m_flags &= ~M_PKTHDR;
2666                 m->m_next = m0;
2667                 m->m_pkthdr.len = m->m_len + m0->m_len;
2668                 m0 = NULL;
2669         }
2670 noredhdropt:;
2671         if (m0) {
2672                 m_freem(m0);
2673                 m0 = NULL;
2674         }
2675
2676         /* XXX: clear embedded link IDs in the inner header */
2677         in6_clearscope(&sip6->ip6_src);
2678         in6_clearscope(&sip6->ip6_dst);
2679         in6_clearscope(&nd_rd->nd_rd_target);
2680         in6_clearscope(&nd_rd->nd_rd_dst);
2681
2682         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2683
2684         nd_rd->nd_rd_cksum = 0;
2685         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2686             sizeof(*ip6), ntohs(ip6->ip6_plen));
2687
2688         if (send_sendso_input_hook != NULL) {
2689                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2690                         M_NOWAIT);
2691                 if (mtag == NULL)
2692                         goto fail;
2693                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2694                 m_tag_prepend(m, mtag);
2695         }
2696
2697         /* send the packet to outside... */
2698         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2699         if (outif) {
2700                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2701                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2702         }
2703         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2704
2705         return;
2706
2707 fail:
2708         if (m)
2709                 m_freem(m);
2710         if (m0)
2711                 m_freem(m0);
2712 }
2713
2714 /*
2715  * ICMPv6 socket option processing.
2716  */
2717 int
2718 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2719 {
2720         int error = 0;
2721         int optlen;
2722         struct inpcb *inp = sotoinpcb(so);
2723         int level, op, optname;
2724
2725         if (sopt) {
2726                 level = sopt->sopt_level;
2727                 op = sopt->sopt_dir;
2728                 optname = sopt->sopt_name;
2729                 optlen = sopt->sopt_valsize;
2730         } else
2731                 level = op = optname = optlen = 0;
2732
2733         if (level != IPPROTO_ICMPV6) {
2734                 return EINVAL;
2735         }
2736
2737         switch (op) {
2738         case PRCO_SETOPT:
2739                 switch (optname) {
2740                 case ICMP6_FILTER:
2741                     {
2742                         struct icmp6_filter ic6f;
2743
2744                         if (optlen != sizeof(ic6f)) {
2745                                 error = EMSGSIZE;
2746                                 break;
2747                         }
2748                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2749                         if (error == 0) {
2750                                 INP_WLOCK(inp);
2751                                 *inp->in6p_icmp6filt = ic6f;
2752                                 INP_WUNLOCK(inp);
2753                         }
2754                         break;
2755                     }
2756
2757                 default:
2758                         error = ENOPROTOOPT;
2759                         break;
2760                 }
2761                 break;
2762
2763         case PRCO_GETOPT:
2764                 switch (optname) {
2765                 case ICMP6_FILTER:
2766                     {
2767                         struct icmp6_filter ic6f;
2768
2769                         INP_RLOCK(inp);
2770                         ic6f = *inp->in6p_icmp6filt;
2771                         INP_RUNLOCK(inp);
2772                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2773                         break;
2774                     }
2775
2776                 default:
2777                         error = ENOPROTOOPT;
2778                         break;
2779                 }
2780                 break;
2781         }
2782
2783         return (error);
2784 }
2785
2786 /*
2787  * Perform rate limit check.
2788  * Returns 0 if it is okay to send the icmp6 packet.
2789  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2790  * limitation.
2791  *
2792  * XXX per-destination/type check necessary?
2793  *
2794  * dst - not used at this moment
2795  * type - not used at this moment
2796  * code - not used at this moment
2797  */
2798 static int
2799 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2800     const int code)
2801 {
2802         int ret;
2803
2804         ret = 0;        /* okay to send */
2805
2806         /* PPS limit */
2807         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2808             V_icmp6errppslim)) {
2809                 /* The packet is subject to rate limit */
2810                 ret++;
2811         }
2812
2813         return ret;
2814 }