sys/netinet6/icmp6.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
  32  */
  33
  34 /*-
  35  * Copyright (c) 1982, 1986, 1988, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  63  */
  64
  65 #include <sys/cdefs.h>
  66 __FBSDID("$FreeBSD$");
  67
  68 #define MBUF_PRIVATE    /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
  69
  70 #include "opt_inet.h"
  71 #include "opt_inet6.h"
  72
  73 #include <sys/param.h>
  74 #include <sys/domain.h>
  75 #include <sys/jail.h>
  76 #include <sys/kernel.h>
  77 #include <sys/lock.h>
  78 #include <sys/malloc.h>
  79 #include <sys/mbuf.h>
  80 #include <sys/proc.h>
  81 #include <sys/protosw.h>
  82 #include <sys/signalvar.h>
  83 #include <sys/socket.h>
  84 #include <sys/socketvar.h>
  85 #include <sys/sx.h>
  86 #include <sys/syslog.h>
  87 #include <sys/systm.h>
  88 #include <sys/time.h>
  89
  90 #include <net/if.h>
  91 #include <net/if_var.h>
  92 #include <net/if_dl.h>
  93 #include <net/if_llatbl.h>
  94 #include <net/if_types.h>
  95 #include <net/route.h>
  96 #include <net/vnet.h>
  97
  98 #include <netinet/in.h>
  99 #include <netinet/in_pcb.h>
 100 #include <netinet/in_var.h>
 101 #include <netinet/ip6.h>
 102 #include <netinet/icmp6.h>
 103 #include <netinet/tcp_var.h>
 104
 105 #include <netinet6/in6_fib.h>
 106 #include <netinet6/in6_ifattach.h>
 107 #include <netinet6/in6_pcb.h>
 108 #include <netinet6/ip6protosw.h>
 109 #include <netinet6/ip6_var.h>
 110 #include <netinet6/scope6_var.h>
 111 #include <netinet6/mld6_var.h>
 112 #include <netinet6/nd6.h>
 113 #include <netinet6/send.h>
 114
 115 extern struct domain inet6domain;
 116
 117 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
 118 VNET_PCPUSTAT_SYSINIT(icmp6stat);
 119
 120 #ifdef VIMAGE
 121 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
 122 #endif /* VIMAGE */
 123
 124 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 125 VNET_DECLARE(struct inpcbhead, ripcb);
 126 VNET_DECLARE(int, icmp6errppslim);
 127 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0;
 128 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last);
 129 VNET_DECLARE(int, icmp6_nodeinfo);
 130
 131 #define V_ripcbinfo                     VNET(ripcbinfo)
 132 #define V_ripcb                         VNET(ripcb)
 133 #define V_icmp6errppslim                VNET(icmp6errppslim)
 134 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 135 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 136 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 137
 138 static void icmp6_errcount(int, int);
 139 static int icmp6_rip6_input(struct mbuf **, int);
 140 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 141 static const char *icmp6_redirect_diag(struct in6_addr *,
 142         struct in6_addr *, struct in6_addr *);
 143 static struct mbuf *ni6_input(struct mbuf *, int);
 144 static struct mbuf *ni6_nametodns(const char *, int, int);
 145 static int ni6_dnsmatch(const char *, int, const char *, int);
 146 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 147                           struct ifnet **, struct in6_addr *);
 148 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 149                                 struct ifnet *, int);
 150 static int icmp6_notify_error(struct mbuf **, int, int, int);
 151
 152 /*
 153  * Kernel module interface for updating icmp6stat.  The argument is an index
 154  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 155  * general layout of icmp6stat into the caller, it doesn't encode its
 156  * location, so that future changes to add, for example, per-CPU stats
 157  * support won't cause binary compatibility problems for kernel modules.
 158  */
 159 void
 160 kmod_icmp6stat_inc(int statnum)
 161 {
 162
 163         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 164 }
 165
 166 static void
 167 icmp6_errcount(int type, int code)
 168 {
 169         switch (type) {
 170         case ICMP6_DST_UNREACH:
 171                 switch (code) {
 172                 case ICMP6_DST_UNREACH_NOROUTE:
 173                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 174                         return;
 175                 case ICMP6_DST_UNREACH_ADMIN:
 176                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 177                         return;
 178                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 179                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 180                         return;
 181                 case ICMP6_DST_UNREACH_ADDR:
 182                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 183                         return;
 184                 case ICMP6_DST_UNREACH_NOPORT:
 185                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 186                         return;
 187                 }
 188                 break;
 189         case ICMP6_PACKET_TOO_BIG:
 190                 ICMP6STAT_INC(icp6s_opacket_too_big);
 191                 return;
 192         case ICMP6_TIME_EXCEEDED:
 193                 switch (code) {
 194                 case ICMP6_TIME_EXCEED_TRANSIT:
 195                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 196                         return;
 197                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 198                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 199                         return;
 200                 }
 201                 break;
 202         case ICMP6_PARAM_PROB:
 203                 switch (code) {
 204                 case ICMP6_PARAMPROB_HEADER:
 205                         ICMP6STAT_INC(icp6s_oparamprob_header);
 206                         return;
 207                 case ICMP6_PARAMPROB_NEXTHEADER:
 208                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 209                         return;
 210                 case ICMP6_PARAMPROB_OPTION:
 211                         ICMP6STAT_INC(icp6s_oparamprob_option);
 212                         return;
 213                 }
 214                 break;
 215         case ND_REDIRECT:
 216                 ICMP6STAT_INC(icp6s_oredirect);
 217                 return;
 218         }
 219         ICMP6STAT_INC(icp6s_ounknown);
 220 }
 221
 222 /*
 223  * A wrapper function for icmp6_error() necessary when the erroneous packet
 224  * may not contain enough scope zone information.
 225  */
 226 void
 227 icmp6_error2(struct mbuf *m, int type, int code, int param,
 228     struct ifnet *ifp)
 229 {
 230         struct ip6_hdr *ip6;
 231
 232         if (ifp == NULL)
 233                 return;
 234
 235 #ifndef PULLDOWN_TEST
 236         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 237 #else
 238         if (m->m_len < sizeof(struct ip6_hdr)) {
 239                 m = m_pullup(m, sizeof(struct ip6_hdr));
 240                 if (m == NULL)
 241                         return;
 242         }
 243 #endif
 244
 245         ip6 = mtod(m, struct ip6_hdr *);
 246
 247         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 248                 return;
 249         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 250                 return;
 251
 252         icmp6_error(m, type, code, param);
 253 }
 254
 255 /*
 256  * Generate an error packet of type error in response to bad IP6 packet.
 257  */
 258 void
 259 icmp6_error(struct mbuf *m, int type, int code, int param)
 260 {
 261         struct ip6_hdr *oip6, *nip6;
 262         struct icmp6_hdr *icmp6;
 263         u_int preplen;
 264         int off;
 265         int nxt;
 266
 267         ICMP6STAT_INC(icp6s_error);
 268
 269         /* count per-type-code statistics */
 270         icmp6_errcount(type, code);
 271
 272 #ifdef M_DECRYPTED      /*not openbsd*/
 273         if (m->m_flags & M_DECRYPTED) {
 274                 ICMP6STAT_INC(icp6s_canterror);
 275                 goto freeit;
 276         }
 277 #endif
 278
 279 #ifndef PULLDOWN_TEST
 280         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 281 #else
 282         if (m->m_len < sizeof(struct ip6_hdr)) {
 283                 m = m_pullup(m, sizeof(struct ip6_hdr));
 284                 if (m == NULL)
 285                         return;
 286         }
 287 #endif
 288         oip6 = mtod(m, struct ip6_hdr *);
 289
 290         /*
 291          * If the destination address of the erroneous packet is a multicast
 292          * address, or the packet was sent using link-layer multicast,
 293          * we should basically suppress sending an error (RFC 2463, Section
 294          * 2.4).
 295          * We have two exceptions (the item e.2 in that section):
 296          * - the Packet Too Big message can be sent for path MTU discovery.
 297          * - the Parameter Problem Message that can be allowed an icmp6 error
 298          *   in the option type field.  This check has been done in
 299          *   ip6_unknown_opt(), so we can just check the type and code.
 300          */
 301         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 302              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 303             (type != ICMP6_PACKET_TOO_BIG &&
 304              (type != ICMP6_PARAM_PROB ||
 305               code != ICMP6_PARAMPROB_OPTION)))
 306                 goto freeit;
 307
 308         /*
 309          * RFC 2463, 2.4 (e.5): source address check.
 310          * XXX: the case of anycast source?
 311          */
 312         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 313             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 314                 goto freeit;
 315
 316         /*
 317          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 318          * don't do it.
 319          */
 320         nxt = -1;
 321         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 322         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 323                 struct icmp6_hdr *icp;
 324
 325 #ifndef PULLDOWN_TEST
 326                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 327                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 328 #else
 329                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 330                         sizeof(*icp));
 331                 if (icp == NULL) {
 332                         ICMP6STAT_INC(icp6s_tooshort);
 333                         return;
 334                 }
 335 #endif
 336                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 337                     icp->icmp6_type == ND_REDIRECT) {
 338                         /*
 339                          * ICMPv6 error
 340                          * Special case: for redirect (which is
 341                          * informational) we must not send icmp6 error.
 342                          */
 343                         ICMP6STAT_INC(icp6s_canterror);
 344                         goto freeit;
 345                 } else {
 346                         /* ICMPv6 informational - send the error */
 347                 }
 348         } else {
 349                 /* non-ICMPv6 - send the error */
 350         }
 351
 352         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 353
 354         /* Finally, do rate limitation check. */
 355         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 356                 ICMP6STAT_INC(icp6s_toofreq);
 357                 goto freeit;
 358         }
 359
 360         /*
 361          * OK, ICMP6 can be generated.
 362          */
 363
 364         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 365                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 366
 367         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 368         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 369         if (m == NULL) {
 370                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 371                 return;
 372         }
 373
 374         nip6 = mtod(m, struct ip6_hdr *);
 375         nip6->ip6_src  = oip6->ip6_src;
 376         nip6->ip6_dst  = oip6->ip6_dst;
 377
 378         in6_clearscope(&oip6->ip6_src);
 379         in6_clearscope(&oip6->ip6_dst);
 380
 381         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 382         icmp6->icmp6_type = type;
 383         icmp6->icmp6_code = code;
 384         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 385
 386         ICMP6STAT_INC(icp6s_outhist[type]);
 387         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 388
 389         return;
 390
 391   freeit:
 392         /*
 393          * If we can't tell whether or not we can generate ICMP6, free it.
 394          */
 395         m_freem(m);
 396 }
 397
 398 /*
 399  * Process a received ICMP6 message.
 400  */
 401 int
 402 icmp6_input(struct mbuf **mp, int *offp, int proto)
 403 {
 404         struct mbuf *m = *mp, *n;
 405         struct ifnet *ifp;
 406         struct ip6_hdr *ip6, *nip6;
 407         struct icmp6_hdr *icmp6, *nicmp6;
 408         int off = *offp;
 409         int icmp6len = m->m_pkthdr.len - *offp;
 410         int code, sum, noff;
 411         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 412         int ip6len, error;
 413
 414         ifp = m->m_pkthdr.rcvif;
 415
 416 #ifndef PULLDOWN_TEST
 417         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 418         /* m might change if M_LOOP.  So, call mtod after this */
 419 #endif
 420
 421         /*
 422          * Locate icmp6 structure in mbuf, and check
 423          * that not corrupted and of at least minimum length
 424          */
 425
 426         ip6 = mtod(m, struct ip6_hdr *);
 427         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 428         if (icmp6len < sizeof(struct icmp6_hdr)) {
 429                 ICMP6STAT_INC(icp6s_tooshort);
 430                 goto freeit;
 431         }
 432
 433         /*
 434          * Check multicast group membership.
 435          * Note: SSM filters are not applied for ICMPv6 traffic.
 436          */
 437         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 438                 struct in6_multi        *inm;
 439
 440                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 441                 if (inm == NULL) {
 442                         IP6STAT_INC(ip6s_notmember);
 443                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 444                         goto freeit;
 445                 }
 446         }
 447
 448         /*
 449          * calculate the checksum
 450          */
 451 #ifndef PULLDOWN_TEST
 452         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 453 #else
 454         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 455         if (icmp6 == NULL) {
 456                 ICMP6STAT_INC(icp6s_tooshort);
 457                 return IPPROTO_DONE;
 458         }
 459 #endif
 460         code = icmp6->icmp6_code;
 461
 462         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 463                 nd6log((LOG_ERR,
 464                     "ICMP6 checksum error(%d|%x) %s\n",
 465                     icmp6->icmp6_type, sum,
 466                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 467                 ICMP6STAT_INC(icp6s_checksum);
 468                 goto freeit;
 469         }
 470
 471         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 472         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 473         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 474                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 475
 476         switch (icmp6->icmp6_type) {
 477         case ICMP6_DST_UNREACH:
 478                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 479                 switch (code) {
 480                 case ICMP6_DST_UNREACH_NOROUTE:
 481                 case ICMP6_DST_UNREACH_ADDR:    /* PRC_HOSTDEAD is a DOS */
 482                         code = PRC_UNREACH_NET;
 483                         break;
 484                 case ICMP6_DST_UNREACH_ADMIN:
 485                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 486                         code = PRC_UNREACH_ADMIN_PROHIB;
 487                         break;
 488                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 489                         /* I mean "source address was incorrect." */
 490                         code = PRC_PARAMPROB;
 491                         break;
 492                 case ICMP6_DST_UNREACH_NOPORT:
 493                         code = PRC_UNREACH_PORT;
 494                         break;
 495                 default:
 496                         goto badcode;
 497                 }
 498                 goto deliver;
 499                 break;
 500
 501         case ICMP6_PACKET_TOO_BIG:
 502                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 503
 504                 /* validation is made in icmp6_mtudisc_update */
 505
 506                 code = PRC_MSGSIZE;
 507
 508                 /*
 509                  * Updating the path MTU will be done after examining
 510                  * intermediate extension headers.
 511                  */
 512                 goto deliver;
 513                 break;
 514
 515         case ICMP6_TIME_EXCEEDED:
 516                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 517                 switch (code) {
 518                 case ICMP6_TIME_EXCEED_TRANSIT:
 519                         code = PRC_TIMXCEED_INTRANS;
 520                         break;
 521                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 522                         code = PRC_TIMXCEED_REASS;
 523                         break;
 524                 default:
 525                         goto badcode;
 526                 }
 527                 goto deliver;
 528                 break;
 529
 530         case ICMP6_PARAM_PROB:
 531                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 532                 switch (code) {
 533                 case ICMP6_PARAMPROB_NEXTHEADER:
 534                         code = PRC_UNREACH_PROTOCOL;
 535                         break;
 536                 case ICMP6_PARAMPROB_HEADER:
 537                 case ICMP6_PARAMPROB_OPTION:
 538                         code = PRC_PARAMPROB;
 539                         break;
 540                 default:
 541                         goto badcode;
 542                 }
 543                 goto deliver;
 544                 break;
 545
 546         case ICMP6_ECHO_REQUEST:
 547                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 548                 if (code != 0)
 549                         goto badcode;
 550                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 551                         /* Give up remote */
 552                         break;
 553                 }
 554                 if (!M_WRITABLE(n)
 555                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 556                         struct mbuf *n0 = n;
 557                         int n0len;
 558
 559                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 560                         n = m_gethdr(M_NOWAIT, n0->m_type);
 561                         if (n == NULL) {
 562                                 /* Give up remote */
 563                                 m_freem(n0);
 564                                 break;
 565                         }
 566
 567                         m_move_pkthdr(n, n0);   /* FIB copied. */
 568                         n0len = n0->m_pkthdr.len;       /* save for use below */
 569                         /*
 570                          * Copy IPv6 and ICMPv6 only.
 571                          */
 572                         nip6 = mtod(n, struct ip6_hdr *);
 573                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 574                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 575                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 576                         noff = sizeof(struct ip6_hdr);
 577                         /* new mbuf contains only ipv6+icmpv6 headers */
 578                         n->m_len = noff + sizeof(struct icmp6_hdr);
 579                         /*
 580                          * Adjust mbuf.  ip6_plen will be adjusted in
 581                          * ip6_output().
 582                          */
 583                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 584                         /* recalculate complete packet size */
 585                         n->m_pkthdr.len = n0len + (noff - off);
 586                         n->m_next = n0;
 587                 } else {
 588                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 589                             sizeof(*nicmp6));
 590                         noff = off;
 591                 }
 592                 if (n) {
 593                         nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 594                         nicmp6->icmp6_code = 0;
 595                         ICMP6STAT_INC(icp6s_reflect);
 596                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 597                         icmp6_reflect(n, noff);
 598                 }
 599                 break;
 600
 601         case ICMP6_ECHO_REPLY:
 602                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 603                 if (code != 0)
 604                         goto badcode;
 605                 break;
 606
 607         case MLD_LISTENER_QUERY:
 608         case MLD_LISTENER_REPORT:
 609         case MLD_LISTENER_DONE:
 610         case MLDV2_LISTENER_REPORT:
 611                 /*
 612                  * Drop MLD traffic which is not link-local, has a hop limit
 613                  * of greater than 1 hop, or which does not have the
 614                  * IPv6 HBH Router Alert option.
 615                  * As IPv6 HBH options are stripped in ip6_input() we must
 616                  * check an mbuf header flag.
 617                  * XXX Should we also sanity check that these messages
 618                  * were directed to a link-local multicast prefix?
 619                  */
 620                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 621                         goto freeit;
 622                 if (mld_input(m, off, icmp6len) != 0)
 623                         return (IPPROTO_DONE);
 624                 /* m stays. */
 625                 break;
 626
 627         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 628             {
 629                 enum { WRU, FQDN } mode;
 630
 631                 if (!V_icmp6_nodeinfo)
 632                         break;
 633
 634                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 635                         mode = WRU;
 636                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 637                         mode = FQDN;
 638                 else
 639                         goto badlen;
 640
 641                 if (mode == FQDN) {
 642 #ifndef PULLDOWN_TEST
 643                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 644                             IPPROTO_DONE);
 645 #endif
 646                         n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 647                         if (n)
 648                                 n = ni6_input(n, off);
 649                         /* XXX meaningless if n == NULL */
 650                         noff = sizeof(struct ip6_hdr);
 651                 } else {
 652                         struct prison *pr;
 653                         u_char *p;
 654                         int maxhlen, hlen;
 655
 656                         /*
 657                          * XXX: this combination of flags is pointless,
 658                          * but should we keep this for compatibility?
 659                          */
 660                         if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
 661                             ICMP6_NODEINFO_TMPADDROK)) !=
 662                             (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
 663                                 break;
 664
 665                         if (code != 0)
 666                                 goto badcode;
 667
 668                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 669                         n = m_gethdr(M_NOWAIT, m->m_type);
 670                         if (n == NULL) {
 671                                 /* Give up remote */
 672                                 break;
 673                         }
 674                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 675                                 /*
 676                                  * Previous code did a blind M_COPY_PKTHDR
 677                                  * and said "just for rcvif".  If true, then
 678                                  * we could tolerate the dup failing (due to
 679                                  * the deep copy of the tag chain).  For now
 680                                  * be conservative and just fail.
 681                                  */
 682                                 m_free(n);
 683                                 n = NULL;
 684                                 break;
 685                         }
 686                         maxhlen = M_TRAILINGSPACE(n) -
 687                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 688                         pr = curthread->td_ucred->cr_prison;
 689                         mtx_lock(&pr->pr_mtx);
 690                         hlen = strlen(pr->pr_hostname);
 691                         if (maxhlen > hlen)
 692                                 maxhlen = hlen;
 693                         /*
 694                          * Copy IPv6 and ICMPv6 only.
 695                          */
 696                         nip6 = mtod(n, struct ip6_hdr *);
 697                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 698                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 699                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 700                         p = (u_char *)(nicmp6 + 1);
 701                         bzero(p, 4);
 702                         /* meaningless TTL */
 703                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 704                         mtx_unlock(&pr->pr_mtx);
 705                         noff = sizeof(struct ip6_hdr);
 706                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 707                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 708                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 709                         nicmp6->icmp6_code = 0;
 710                 }
 711                 if (n) {
 712                         ICMP6STAT_INC(icp6s_reflect);
 713                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 714                         icmp6_reflect(n, noff);
 715                 }
 716                 break;
 717             }
 718
 719         case ICMP6_WRUREPLY:
 720                 if (code != 0)
 721                         goto badcode;
 722                 break;
 723
 724         case ND_ROUTER_SOLICIT:
 725                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 726                 if (code != 0)
 727                         goto badcode;
 728                 if (icmp6len < sizeof(struct nd_router_solicit))
 729                         goto badlen;
 730                 if (send_sendso_input_hook != NULL) {
 731                         IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
 732                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 733                         if (error == 0) {
 734                                 m = NULL;
 735                                 goto freeit;
 736                         }
 737                 }
 738                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 739                 nd6_rs_input(m, off, icmp6len);
 740                 m = n;
 741                 if (m == NULL)
 742                         goto freeit;
 743                 break;
 744
 745         case ND_ROUTER_ADVERT:
 746                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 747                 if (code != 0)
 748                         goto badcode;
 749                 if (icmp6len < sizeof(struct nd_router_advert))
 750                         goto badlen;
 751                 if (send_sendso_input_hook != NULL) {
 752                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 753                         if (error == 0) {
 754                                 m = NULL;
 755                                 goto freeit;
 756                         }
 757                 }
 758                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 759                 nd6_ra_input(m, off, icmp6len);
 760                 m = n;
 761                 if (m == NULL)
 762                         goto freeit;
 763                 break;
 764
 765         case ND_NEIGHBOR_SOLICIT:
 766                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 767                 if (code != 0)
 768                         goto badcode;
 769                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 770                         goto badlen;
 771                 if (send_sendso_input_hook != NULL) {
 772                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 773                         if (error == 0) {
 774                                 m = NULL;
 775                                 goto freeit;
 776                         }
 777                 }
 778                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 779                 nd6_ns_input(m, off, icmp6len);
 780                 m = n;
 781                 if (m == NULL)
 782                         goto freeit;
 783                 break;
 784
 785         case ND_NEIGHBOR_ADVERT:
 786                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 787                 if (code != 0)
 788                         goto badcode;
 789                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 790                         goto badlen;
 791                 if (send_sendso_input_hook != NULL) {
 792                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 793                         if (error == 0) {
 794                                 m = NULL;
 795                                 goto freeit;
 796                         }
 797                 }
 798                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 799                 nd6_na_input(m, off, icmp6len);
 800                 m = n;
 801                 if (m == NULL)
 802                         goto freeit;
 803                 break;
 804
 805         case ND_REDIRECT:
 806                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 807                 if (code != 0)
 808                         goto badcode;
 809                 if (icmp6len < sizeof(struct nd_redirect))
 810                         goto badlen;
 811                 if (send_sendso_input_hook != NULL) {
 812                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 813                         if (error == 0) {
 814                                 m = NULL;
 815                                 goto freeit;
 816                         }
 817                 }
 818                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 819                 icmp6_redirect_input(m, off);
 820                 m = n;
 821                 if (m == NULL)
 822                         goto freeit;
 823                 break;
 824
 825         case ICMP6_ROUTER_RENUMBERING:
 826                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 827                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 828                         goto badcode;
 829                 if (icmp6len < sizeof(struct icmp6_router_renum))
 830                         goto badlen;
 831                 break;
 832
 833         default:
 834                 nd6log((LOG_DEBUG,
 835                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 836                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 837                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 838                     ifp ? ifp->if_index : 0));
 839                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 840                         /* ICMPv6 error: MUST deliver it by spec... */
 841                         code = PRC_NCMDS;
 842                         /* deliver */
 843                 } else {
 844                         /* ICMPv6 informational: MUST not deliver */
 845                         break;
 846                 }
 847         deliver:
 848                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 849                         /* In this case, m should've been freed. */
 850                         return (IPPROTO_DONE);
 851                 }
 852                 break;
 853
 854         badcode:
 855                 ICMP6STAT_INC(icp6s_badcode);
 856                 break;
 857
 858         badlen:
 859                 ICMP6STAT_INC(icp6s_badlen);
 860                 break;
 861         }
 862
 863         /* deliver the packet to appropriate sockets */
 864         icmp6_rip6_input(&m, *offp);
 865
 866         return IPPROTO_DONE;
 867
 868  freeit:
 869         m_freem(m);
 870         return IPPROTO_DONE;
 871 }
 872
 873 static int
 874 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 875 {
 876         struct mbuf *m = *mp;
 877         struct icmp6_hdr *icmp6;
 878         struct ip6_hdr *eip6;
 879         u_int32_t notifymtu;
 880         struct sockaddr_in6 icmp6src, icmp6dst;
 881
 882         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 883                 ICMP6STAT_INC(icp6s_tooshort);
 884                 goto freeit;
 885         }
 886 #ifndef PULLDOWN_TEST
 887         IP6_EXTHDR_CHECK(m, off,
 888             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 889         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 890 #else
 891         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 892             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 893         if (icmp6 == NULL) {
 894                 ICMP6STAT_INC(icp6s_tooshort);
 895                 return (-1);
 896         }
 897 #endif
 898         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 899         bzero(&icmp6dst, sizeof(icmp6dst));
 900
 901         /* Detect the upper level protocol */
 902         {
 903                 void (*ctlfunc)(int, struct sockaddr *, void *);
 904                 u_int8_t nxt = eip6->ip6_nxt;
 905                 int eoff = off + sizeof(struct icmp6_hdr) +
 906                     sizeof(struct ip6_hdr);
 907                 struct ip6ctlparam ip6cp;
 908                 int icmp6type = icmp6->icmp6_type;
 909                 struct ip6_frag *fh;
 910                 struct ip6_rthdr *rth;
 911                 struct ip6_rthdr0 *rth0;
 912                 int rthlen;
 913
 914                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 915                         struct ip6_ext *eh;
 916
 917                         switch (nxt) {
 918                         case IPPROTO_HOPOPTS:
 919                         case IPPROTO_DSTOPTS:
 920                         case IPPROTO_AH:
 921 #ifndef PULLDOWN_TEST
 922                                 IP6_EXTHDR_CHECK(m, 0,
 923                                     eoff + sizeof(struct ip6_ext), -1);
 924                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
 925 #else
 926                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 927                                     eoff, sizeof(*eh));
 928                                 if (eh == NULL) {
 929                                         ICMP6STAT_INC(icp6s_tooshort);
 930                                         return (-1);
 931                                 }
 932 #endif
 933
 934                                 if (nxt == IPPROTO_AH)
 935                                         eoff += (eh->ip6e_len + 2) << 2;
 936                                 else
 937                                         eoff += (eh->ip6e_len + 1) << 3;
 938                                 nxt = eh->ip6e_nxt;
 939                                 break;
 940                         case IPPROTO_ROUTING:
 941                                 /*
 942                                  * When the erroneous packet contains a
 943                                  * routing header, we should examine the
 944                                  * header to determine the final destination.
 945                                  * Otherwise, we can't properly update
 946                                  * information that depends on the final
 947                                  * destination (e.g. path MTU).
 948                                  */
 949 #ifndef PULLDOWN_TEST
 950                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
 951                                 rth = (struct ip6_rthdr *)
 952                                     (mtod(m, caddr_t) + eoff);
 953 #else
 954                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 955                                     eoff, sizeof(*rth));
 956                                 if (rth == NULL) {
 957                                         ICMP6STAT_INC(icp6s_tooshort);
 958                                         return (-1);
 959                                 }
 960 #endif
 961                                 rthlen = (rth->ip6r_len + 1) << 3;
 962                                 /*
 963                                  * XXX: currently there is no
 964                                  * officially defined type other
 965                                  * than type-0.
 966                                  * Note that if the segment left field
 967                                  * is 0, all intermediate hops must
 968                                  * have been passed.
 969                                  */
 970                                 if (rth->ip6r_segleft &&
 971                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 972                                         int hops;
 973
 974 #ifndef PULLDOWN_TEST
 975                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
 976                                         rth0 = (struct ip6_rthdr0 *)
 977                                             (mtod(m, caddr_t) + eoff);
 978 #else
 979                                         IP6_EXTHDR_GET(rth0,
 980                                             struct ip6_rthdr0 *, m,
 981                                             eoff, rthlen);
 982                                         if (rth0 == NULL) {
 983                                                 ICMP6STAT_INC(icp6s_tooshort);
 984                                                 return (-1);
 985                                         }
 986 #endif
 987                                         /* just ignore a bogus header */
 988                                         if ((rth0->ip6r0_len % 2) == 0 &&
 989                                             (hops = rth0->ip6r0_len/2))
 990                                                 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1));
 991                                 }
 992                                 eoff += rthlen;
 993                                 nxt = rth->ip6r_nxt;
 994                                 break;
 995                         case IPPROTO_FRAGMENT:
 996 #ifndef PULLDOWN_TEST
 997                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 998                                     sizeof(struct ip6_frag), -1);
 999                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1000                                     eoff);
1001 #else
1002                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1003                                     eoff, sizeof(*fh));
1004                                 if (fh == NULL) {
1005                                         ICMP6STAT_INC(icp6s_tooshort);
1006                                         return (-1);
1007                                 }
1008 #endif
1009                                 /*
1010                                  * Data after a fragment header is meaningless
1011                                  * unless it is the first fragment, but
1012                                  * we'll go to the notify label for path MTU
1013                                  * discovery.
1014                                  */
1015                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1016                                         goto notify;
1017
1018                                 eoff += sizeof(struct ip6_frag);
1019                                 nxt = fh->ip6f_nxt;
1020                                 break;
1021                         default:
1022                                 /*
1023                                  * This case includes ESP and the No Next
1024                                  * Header.  In such cases going to the notify
1025                                  * label does not have any meaning
1026                                  * (i.e. ctlfunc will be NULL), but we go
1027                                  * anyway since we might have to update
1028                                  * path MTU information.
1029                                  */
1030                                 goto notify;
1031                         }
1032                 }
1033           notify:
1034 #ifndef PULLDOWN_TEST
1035                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1036 #else
1037                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1038                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1039                 if (icmp6 == NULL) {
1040                         ICMP6STAT_INC(icp6s_tooshort);
1041                         return (-1);
1042                 }
1043 #endif
1044
1045                 /*
1046                  * retrieve parameters from the inner IPv6 header, and convert
1047                  * them into sockaddr structures.
1048                  * XXX: there is no guarantee that the source or destination
1049                  * addresses of the inner packet are in the same scope as
1050                  * the addresses of the icmp packet.  But there is no other
1051                  * way to determine the zone.
1052                  */
1053                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1054
1055                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1056                 icmp6dst.sin6_family = AF_INET6;
1057                 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr))
1058                         icmp6dst.sin6_addr = eip6->ip6_dst;
1059                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1060                         goto freeit;
1061                 bzero(&icmp6src, sizeof(icmp6src));
1062                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1063                 icmp6src.sin6_family = AF_INET6;
1064                 icmp6src.sin6_addr = eip6->ip6_src;
1065                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1066                         goto freeit;
1067                 icmp6src.sin6_flowinfo =
1068                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1069
1070                 ip6cp.ip6c_m = m;
1071                 ip6cp.ip6c_icmp6 = icmp6;
1072                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1073                 ip6cp.ip6c_off = eoff;
1074                 ip6cp.ip6c_finaldst = &icmp6dst.sin6_addr;
1075                 ip6cp.ip6c_src = &icmp6src;
1076                 ip6cp.ip6c_nxt = nxt;
1077
1078                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1079                         notifymtu = ntohl(icmp6->icmp6_mtu);
1080                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1081                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1082                 }
1083
1084                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1085                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1086                 if (ctlfunc) {
1087                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1088                             &ip6cp);
1089                 }
1090         }
1091         *mp = m;
1092         return (0);
1093
1094   freeit:
1095         m_freem(m);
1096         return (-1);
1097 }
1098
1099 void
1100 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1101 {
1102         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1103         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1104         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1105         u_int mtu = ntohl(icmp6->icmp6_mtu);
1106         struct in_conninfo inc;
1107
1108 #if 0
1109         /*
1110          * RFC2460 section 5, last paragraph.
1111          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1112          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1113          * due to packet translator in the middle.
1114          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1115          * special handling.
1116          */
1117         if (mtu < IPV6_MMTU)
1118                 return;
1119 #endif
1120
1121         /*
1122          * we reject ICMPv6 too big with abnormally small value.
1123          * XXX what is the good definition of "abnormally small"?
1124          */
1125         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1126                 return;
1127
1128         if (!validated)
1129                 return;
1130
1131         /*
1132          * In case the suggested mtu is less than IPV6_MMTU, we
1133          * only need to remember that it was for above mentioned
1134          * "alwaysfrag" case.
1135          * Try to be as close to the spec as possible.
1136          */
1137         if (mtu < IPV6_MMTU)
1138                 mtu = IPV6_MMTU - 8;
1139
1140         bzero(&inc, sizeof(inc));
1141         inc.inc_fibnum = M_GETFIB(m);
1142         inc.inc_flags |= INC_ISIPV6;
1143         inc.inc6_faddr = *dst;
1144         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1145                 return;
1146
1147         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1148                 tcp_hc_updatemtu(&inc, mtu);
1149                 ICMP6STAT_INC(icp6s_pmtuchg);
1150         }
1151 }
1152
1153 /*
1154  * Process a Node Information Query packet, based on
1155  * draft-ietf-ipngwg-icmp-name-lookups-07.
1156  *
1157  * Spec incompatibilities:
1158  * - IPv6 Subject address handling
1159  * - IPv4 Subject address handling support missing
1160  * - Proxy reply (answer even if it's not for me)
1161  * - joins NI group address at in6_ifattach() time only, does not cope
1162  *   with hostname changes by sethostname(3)
1163  */
1164 static struct mbuf *
1165 ni6_input(struct mbuf *m, int off)
1166 {
1167         struct icmp6_nodeinfo *ni6, *nni6;
1168         struct mbuf *n = NULL;
1169         struct prison *pr;
1170         u_int16_t qtype;
1171         int subjlen;
1172         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1173         struct ni_reply_fqdn *fqdn;
1174         int addrs;              /* for NI_QTYPE_NODEADDR */
1175         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1176         struct in6_addr in6_subj; /* subject address */
1177         struct ip6_hdr *ip6;
1178         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1179         char *subj = NULL;
1180         struct in6_ifaddr *ia6 = NULL;
1181
1182         ip6 = mtod(m, struct ip6_hdr *);
1183 #ifndef PULLDOWN_TEST
1184         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1185 #else
1186         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1187         if (ni6 == NULL) {
1188                 /* m is already reclaimed */
1189                 return (NULL);
1190         }
1191 #endif
1192
1193         /*
1194          * Validate IPv6 source address.
1195          * The default configuration MUST be to refuse answering queries from
1196          * global-scope addresses according to RFC4602.
1197          * Notes:
1198          *  - it's not very clear what "refuse" means; this implementation
1199          *    simply drops it.
1200          *  - it's not very easy to identify global-scope (unicast) addresses
1201          *    since there are many prefixes for them.  It should be safer
1202          *    and in practice sufficient to check "all" but loopback and
1203          *    link-local (note that site-local unicast was deprecated and
1204          *    ULA is defined as global scope-wise)
1205          */
1206         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1207             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1208             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1209                 goto bad;
1210
1211         /*
1212          * Validate IPv6 destination address.
1213          *
1214          * The Responder must discard the Query without further processing
1215          * unless it is one of the Responder's unicast or anycast addresses, or
1216          * a link-local scope multicast address which the Responder has joined.
1217          * [RFC4602, Section 5.]
1218          */
1219         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1220                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1221                         goto bad;
1222                 /* else it's a link-local multicast, fine */
1223         } else {                /* unicast or anycast */
1224                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
1225                 if (ia6 == NULL)
1226                         goto bad; /* XXX impossible */
1227
1228                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1229                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1230                         ifa_free(&ia6->ia_ifa);
1231                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1232                                 "a temporary address in %s:%d",
1233                                __FILE__, __LINE__));
1234                         goto bad;
1235                 }
1236                 ifa_free(&ia6->ia_ifa);
1237         }
1238
1239         /* validate query Subject field. */
1240         qtype = ntohs(ni6->ni_qtype);
1241         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1242         switch (qtype) {
1243         case NI_QTYPE_NOOP:
1244         case NI_QTYPE_SUPTYPES:
1245                 /* 07 draft */
1246                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1247                         break;
1248                 /* FALLTHROUGH */
1249         case NI_QTYPE_FQDN:
1250         case NI_QTYPE_NODEADDR:
1251         case NI_QTYPE_IPV4ADDR:
1252                 switch (ni6->ni_code) {
1253                 case ICMP6_NI_SUBJ_IPV6:
1254 #if ICMP6_NI_SUBJ_IPV6 != 0
1255                 case 0:
1256 #endif
1257                         /*
1258                          * backward compatibility - try to accept 03 draft
1259                          * format, where no Subject is present.
1260                          */
1261                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1262                             subjlen == 0) {
1263                                 oldfqdn++;
1264                                 break;
1265                         }
1266 #if ICMP6_NI_SUBJ_IPV6 != 0
1267                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1268                                 goto bad;
1269 #endif
1270
1271                         if (subjlen != sizeof(struct in6_addr))
1272                                 goto bad;
1273
1274                         /*
1275                          * Validate Subject address.
1276                          *
1277                          * Not sure what exactly "address belongs to the node"
1278                          * means in the spec, is it just unicast, or what?
1279                          *
1280                          * At this moment we consider Subject address as
1281                          * "belong to the node" if the Subject address equals
1282                          * to the IPv6 destination address; validation for
1283                          * IPv6 destination address should have done enough
1284                          * check for us.
1285                          *
1286                          * We do not do proxy at this moment.
1287                          */
1288                         /* m_pulldown instead of copy? */
1289                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1290                             subjlen, (caddr_t)&in6_subj);
1291                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1292                                 goto bad;
1293
1294                         subj = (char *)&in6_subj;
1295                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1296                                 break;
1297
1298                         /*
1299                          * XXX if we are to allow other cases, we should really
1300                          * be careful about scope here.
1301                          * basically, we should disallow queries toward IPv6
1302                          * destination X with subject Y,
1303                          * if scope(X) > scope(Y).
1304                          * if we allow scope(X) > scope(Y), it will result in
1305                          * information leakage across scope boundary.
1306                          */
1307                         goto bad;
1308
1309                 case ICMP6_NI_SUBJ_FQDN:
1310                         /*
1311                          * Validate Subject name with gethostname(3).
1312                          *
1313                          * The behavior may need some debate, since:
1314                          * - we are not sure if the node has FQDN as
1315                          *   hostname (returned by gethostname(3)).
1316                          * - the code does wildcard match for truncated names.
1317                          *   however, we are not sure if we want to perform
1318                          *   wildcard match, if gethostname(3) side has
1319                          *   truncated hostname.
1320                          */
1321                         pr = curthread->td_ucred->cr_prison;
1322                         mtx_lock(&pr->pr_mtx);
1323                         n = ni6_nametodns(pr->pr_hostname,
1324                             strlen(pr->pr_hostname), 0);
1325                         mtx_unlock(&pr->pr_mtx);
1326                         if (!n || n->m_next || n->m_len == 0)
1327                                 goto bad;
1328                         IP6_EXTHDR_GET(subj, char *, m,
1329                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1330                         if (subj == NULL)
1331                                 goto bad;
1332                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1333                             n->m_len)) {
1334                                 goto bad;
1335                         }
1336                         m_freem(n);
1337                         n = NULL;
1338                         break;
1339
1340                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1341                 default:
1342                         goto bad;
1343                 }
1344                 break;
1345         }
1346
1347         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1348         switch (qtype) {
1349         case NI_QTYPE_FQDN:
1350                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1351                         goto bad;
1352                 break;
1353         case NI_QTYPE_NODEADDR:
1354         case NI_QTYPE_IPV4ADDR:
1355                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1356                         goto bad;
1357                 break;
1358         }
1359
1360         /* guess reply length */
1361         switch (qtype) {
1362         case NI_QTYPE_NOOP:
1363                 break;          /* no reply data */
1364         case NI_QTYPE_SUPTYPES:
1365                 replylen += sizeof(u_int32_t);
1366                 break;
1367         case NI_QTYPE_FQDN:
1368                 /* XXX will append an mbuf */
1369                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1370                 break;
1371         case NI_QTYPE_NODEADDR:
1372                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1373                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1374                     sizeof(u_int32_t))) > MCLBYTES)
1375                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1376                 break;
1377         case NI_QTYPE_IPV4ADDR:
1378                 /* unsupported - should respond with unknown Qtype? */
1379                 break;
1380         default:
1381                 /*
1382                  * XXX: We must return a reply with the ICMP6 code
1383                  * `unknown Qtype' in this case.  However we regard the case
1384                  * as an FQDN query for backward compatibility.
1385                  * Older versions set a random value to this field,
1386                  * so it rarely varies in the defined qtypes.
1387                  * But the mechanism is not reliable...
1388                  * maybe we should obsolete older versions.
1389                  */
1390                 qtype = NI_QTYPE_FQDN;
1391                 /* XXX will append an mbuf */
1392                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1393                 oldfqdn++;
1394                 break;
1395         }
1396
1397         /* Allocate an mbuf to reply. */
1398         if (replylen > MCLBYTES) {
1399                 /*
1400                  * XXX: should we try to allocate more? But MCLBYTES
1401                  * is probably much larger than IPV6_MMTU...
1402                  */
1403                 goto bad;
1404         }
1405         if (replylen > MHLEN)
1406                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1407         else
1408                 n = m_gethdr(M_NOWAIT, m->m_type);
1409         if (n == NULL) {
1410                 m_freem(m);
1411                 return (NULL);
1412         }
1413         m_move_pkthdr(n, m); /* just for recvif and FIB */
1414         n->m_pkthdr.len = n->m_len = replylen;
1415
1416         /* copy mbuf header and IPv6 + Node Information base headers */
1417         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1418         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1419         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1420
1421         /* qtype dependent procedure */
1422         switch (qtype) {
1423         case NI_QTYPE_NOOP:
1424                 nni6->ni_code = ICMP6_NI_SUCCESS;
1425                 nni6->ni_flags = 0;
1426                 break;
1427         case NI_QTYPE_SUPTYPES:
1428         {
1429                 u_int32_t v;
1430                 nni6->ni_code = ICMP6_NI_SUCCESS;
1431                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1432                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1433                 v = (u_int32_t)htonl(0x0000000f);
1434                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1435                 break;
1436         }
1437         case NI_QTYPE_FQDN:
1438                 nni6->ni_code = ICMP6_NI_SUCCESS;
1439                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1440                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1441                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1442                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1443                 /*
1444                  * XXX do we really have FQDN in hostname?
1445                  */
1446                 pr = curthread->td_ucred->cr_prison;
1447                 mtx_lock(&pr->pr_mtx);
1448                 n->m_next = ni6_nametodns(pr->pr_hostname,
1449                     strlen(pr->pr_hostname), oldfqdn);
1450                 mtx_unlock(&pr->pr_mtx);
1451                 if (n->m_next == NULL)
1452                         goto bad;
1453                 /* XXX we assume that n->m_next is not a chain */
1454                 if (n->m_next->m_next != NULL)
1455                         goto bad;
1456                 n->m_pkthdr.len += n->m_next->m_len;
1457                 break;
1458         case NI_QTYPE_NODEADDR:
1459         {
1460                 int lenlim, copied;
1461
1462                 nni6->ni_code = ICMP6_NI_SUCCESS;
1463                 n->m_pkthdr.len = n->m_len =
1464                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1465                 lenlim = M_TRAILINGSPACE(n);
1466                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1467                 /* XXX: reset mbuf length */
1468                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1469                     sizeof(struct icmp6_nodeinfo) + copied;
1470                 break;
1471         }
1472         default:
1473                 break;          /* XXX impossible! */
1474         }
1475
1476         nni6->ni_type = ICMP6_NI_REPLY;
1477         m_freem(m);
1478         return (n);
1479
1480   bad:
1481         m_freem(m);
1482         if (n)
1483                 m_freem(n);
1484         return (NULL);
1485 }
1486
1487 /*
1488  * make a mbuf with DNS-encoded string.  no compression support.
1489  *
1490  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1491  * treated as truncated name (two \0 at the end).  this is a wild guess.
1492  *
1493  * old - return pascal string if non-zero
1494  */
1495 static struct mbuf *
1496 ni6_nametodns(const char *name, int namelen, int old)
1497 {
1498         struct mbuf *m;
1499         char *cp, *ep;
1500         const char *p, *q;
1501         int i, len, nterm;
1502
1503         if (old)
1504                 len = namelen + 1;
1505         else
1506                 len = MCLBYTES;
1507
1508         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1509         if (len > MLEN)
1510                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1511         else
1512                 m = m_get(M_NOWAIT, MT_DATA);
1513         if (m == NULL)
1514                 goto fail;
1515
1516         if (old) {
1517                 m->m_len = len;
1518                 *mtod(m, char *) = namelen;
1519                 bcopy(name, mtod(m, char *) + 1, namelen);
1520                 return m;
1521         } else {
1522                 m->m_len = 0;
1523                 cp = mtod(m, char *);
1524                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1525
1526                 /* if not certain about my name, return empty buffer */
1527                 if (namelen == 0)
1528                         return m;
1529
1530                 /*
1531                  * guess if it looks like shortened hostname, or FQDN.
1532                  * shortened hostname needs two trailing "\0".
1533                  */
1534                 i = 0;
1535                 for (p = name; p < name + namelen; p++) {
1536                         if (*p && *p == '.')
1537                                 i++;
1538                 }
1539                 if (i < 2)
1540                         nterm = 2;
1541                 else
1542                         nterm = 1;
1543
1544                 p = name;
1545                 while (cp < ep && p < name + namelen) {
1546                         i = 0;
1547                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1548                                 i++;
1549                         /* result does not fit into mbuf */
1550                         if (cp + i + 1 >= ep)
1551                                 goto fail;
1552                         /*
1553                          * DNS label length restriction, RFC1035 page 8.
1554                          * "i == 0" case is included here to avoid returning
1555                          * 0-length label on "foo..bar".
1556                          */
1557                         if (i <= 0 || i >= 64)
1558                                 goto fail;
1559                         *cp++ = i;
1560                         bcopy(p, cp, i);
1561                         cp += i;
1562                         p = q;
1563                         if (p < name + namelen && *p == '.')
1564                                 p++;
1565                 }
1566                 /* termination */
1567                 if (cp + nterm >= ep)
1568                         goto fail;
1569                 while (nterm-- > 0)
1570                         *cp++ = '\0';
1571                 m->m_len = cp - mtod(m, char *);
1572                 return m;
1573         }
1574
1575         panic("should not reach here");
1576         /* NOTREACHED */
1577
1578  fail:
1579         if (m)
1580                 m_freem(m);
1581         return NULL;
1582 }
1583
1584 /*
1585  * check if two DNS-encoded string matches.  takes care of truncated
1586  * form (with \0\0 at the end).  no compression support.
1587  * XXX upper/lowercase match (see RFC2065)
1588  */
1589 static int
1590 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1591 {
1592         const char *a0, *b0;
1593         int l;
1594
1595         /* simplest case - need validation? */
1596         if (alen == blen && bcmp(a, b, alen) == 0)
1597                 return 1;
1598
1599         a0 = a;
1600         b0 = b;
1601
1602         /* termination is mandatory */
1603         if (alen < 2 || blen < 2)
1604                 return 0;
1605         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1606                 return 0;
1607         alen--;
1608         blen--;
1609
1610         while (a - a0 < alen && b - b0 < blen) {
1611                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1612                         return 0;
1613
1614                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1615                         return 0;
1616                 /* we don't support compression yet */
1617                 if (a[0] >= 64 || b[0] >= 64)
1618                         return 0;
1619
1620                 /* truncated case */
1621                 if (a[0] == 0 && a - a0 == alen - 1)
1622                         return 1;
1623                 if (b[0] == 0 && b - b0 == blen - 1)
1624                         return 1;
1625                 if (a[0] == 0 || b[0] == 0)
1626                         return 0;
1627
1628                 if (a[0] != b[0])
1629                         return 0;
1630                 l = a[0];
1631                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1632                         return 0;
1633                 if (bcmp(a + 1, b + 1, l) != 0)
1634                         return 0;
1635
1636                 a += 1 + l;
1637                 b += 1 + l;
1638         }
1639
1640         if (a - a0 == alen && b - b0 == blen)
1641                 return 1;
1642         else
1643                 return 0;
1644 }
1645
1646 /*
1647  * calculate the number of addresses to be returned in the node info reply.
1648  */
1649 static int
1650 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1651     struct in6_addr *subj)
1652 {
1653         struct ifnet *ifp;
1654         struct in6_ifaddr *ifa6;
1655         struct ifaddr *ifa;
1656         int addrs = 0, addrsofif, iffound = 0;
1657         int niflags = ni6->ni_flags;
1658
1659         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1660                 switch (ni6->ni_code) {
1661                 case ICMP6_NI_SUBJ_IPV6:
1662                         if (subj == NULL) /* must be impossible... */
1663                                 return (0);
1664                         break;
1665                 default:
1666                         /*
1667                          * XXX: we only support IPv6 subject address for
1668                          * this Qtype.
1669                          */
1670                         return (0);
1671                 }
1672         }
1673
1674         IFNET_RLOCK_NOSLEEP();
1675         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1676                 addrsofif = 0;
1677                 IF_ADDR_RLOCK(ifp);
1678                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1679                         if (ifa->ifa_addr->sa_family != AF_INET6)
1680                                 continue;
1681                         ifa6 = (struct in6_ifaddr *)ifa;
1682
1683                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1684                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1685                                 iffound = 1;
1686
1687                         /*
1688                          * IPv4-mapped addresses can only be returned by a
1689                          * Node Information proxy, since they represent
1690                          * addresses of IPv4-only nodes, which perforce do
1691                          * not implement this protocol.
1692                          * [icmp-name-lookups-07, Section 5.4]
1693                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1694                          * this function at this moment.
1695                          */
1696
1697                         /* What do we have to do about ::1? */
1698                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1699                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1700                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1701                                         continue;
1702                                 break;
1703                         case IPV6_ADDR_SCOPE_SITELOCAL:
1704                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1705                                         continue;
1706                                 break;
1707                         case IPV6_ADDR_SCOPE_GLOBAL:
1708                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1709                                         continue;
1710                                 break;
1711                         default:
1712                                 continue;
1713                         }
1714
1715                         /*
1716                          * check if anycast is okay.
1717                          * XXX: just experimental.  not in the spec.
1718                          */
1719                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1720                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1721                                 continue; /* we need only unicast addresses */
1722                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1723                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1724                                 continue;
1725                         }
1726                         addrsofif++; /* count the address */
1727                 }
1728                 IF_ADDR_RUNLOCK(ifp);
1729                 if (iffound) {
1730                         *ifpp = ifp;
1731                         IFNET_RUNLOCK_NOSLEEP();
1732                         return (addrsofif);
1733                 }
1734
1735                 addrs += addrsofif;
1736         }
1737         IFNET_RUNLOCK_NOSLEEP();
1738
1739         return (addrs);
1740 }
1741
1742 static int
1743 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1744     struct ifnet *ifp0, int resid)
1745 {
1746         struct ifnet *ifp;
1747         struct in6_ifaddr *ifa6;
1748         struct ifaddr *ifa;
1749         struct ifnet *ifp_dep = NULL;
1750         int copied = 0, allow_deprecated = 0;
1751         u_char *cp = (u_char *)(nni6 + 1);
1752         int niflags = ni6->ni_flags;
1753         u_int32_t ltime;
1754
1755         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1756                 return (0);     /* needless to copy */
1757
1758         IFNET_RLOCK_NOSLEEP();
1759         ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet);
1760   again:
1761
1762         for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) {
1763                 IF_ADDR_RLOCK(ifp);
1764                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1765                         if (ifa->ifa_addr->sa_family != AF_INET6)
1766                                 continue;
1767                         ifa6 = (struct in6_ifaddr *)ifa;
1768
1769                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1770                             allow_deprecated == 0) {
1771                                 /*
1772                                  * prefererred address should be put before
1773                                  * deprecated addresses.
1774                                  */
1775
1776                                 /* record the interface for later search */
1777                                 if (ifp_dep == NULL)
1778                                         ifp_dep = ifp;
1779
1780                                 continue;
1781                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1782                             allow_deprecated != 0)
1783                                 continue; /* we now collect deprecated addrs */
1784
1785                         /* What do we have to do about ::1? */
1786                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1787                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1788                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1789                                         continue;
1790                                 break;
1791                         case IPV6_ADDR_SCOPE_SITELOCAL:
1792                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1793                                         continue;
1794                                 break;
1795                         case IPV6_ADDR_SCOPE_GLOBAL:
1796                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1797                                         continue;
1798                                 break;
1799                         default:
1800                                 continue;
1801                         }
1802
1803                         /*
1804                          * check if anycast is okay.
1805                          * XXX: just experimental.  not in the spec.
1806                          */
1807                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1808                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1809                                 continue;
1810                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1811                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1812                                 continue;
1813                         }
1814
1815                         /* now we can copy the address */
1816                         if (resid < sizeof(struct in6_addr) +
1817                             sizeof(u_int32_t)) {
1818                                 IF_ADDR_RUNLOCK(ifp);
1819                                 /*
1820                                  * We give up much more copy.
1821                                  * Set the truncate flag and return.
1822                                  */
1823                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1824                                 IFNET_RUNLOCK_NOSLEEP();
1825                                 return (copied);
1826                         }
1827
1828                         /*
1829                          * Set the TTL of the address.
1830                          * The TTL value should be one of the following
1831                          * according to the specification:
1832                          *
1833                          * 1. The remaining lifetime of a DHCP lease on the
1834                          *    address, or
1835                          * 2. The remaining Valid Lifetime of a prefix from
1836                          *    which the address was derived through Stateless
1837                          *    Autoconfiguration.
1838                          *
1839                          * Note that we currently do not support stateful
1840                          * address configuration by DHCPv6, so the former
1841                          * case can't happen.
1842                          */
1843                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1844                                 ltime = ND6_INFINITE_LIFETIME;
1845                         else {
1846                                 if (ifa6->ia6_lifetime.ia6t_expire >
1847                                     time_uptime)
1848                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1849                                 else
1850                                         ltime = 0;
1851                         }
1852
1853                         bcopy(&ltime, cp, sizeof(u_int32_t));
1854                         cp += sizeof(u_int32_t);
1855
1856                         /* copy the address itself */
1857                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1858                             sizeof(struct in6_addr));
1859                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1860                         cp += sizeof(struct in6_addr);
1861
1862                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1863                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1864                 }
1865                 IF_ADDR_RUNLOCK(ifp);
1866                 if (ifp0)       /* we need search only on the specified IF */
1867                         break;
1868         }
1869
1870         if (allow_deprecated == 0 && ifp_dep != NULL) {
1871                 ifp = ifp_dep;
1872                 allow_deprecated = 1;
1873
1874                 goto again;
1875         }
1876
1877         IFNET_RUNLOCK_NOSLEEP();
1878
1879         return (copied);
1880 }
1881
1882 /*
1883  * XXX almost dup'ed code with rip6_input.
1884  */
1885 static int
1886 icmp6_rip6_input(struct mbuf **mp, int off)
1887 {
1888         struct mbuf *m = *mp;
1889         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1890         struct inpcb *in6p;
1891         struct inpcb *last = NULL;
1892         struct sockaddr_in6 fromsa;
1893         struct icmp6_hdr *icmp6;
1894         struct epoch_tracker et;
1895         struct mbuf *opts = NULL;
1896
1897 #ifndef PULLDOWN_TEST
1898         /* this is assumed to be safe. */
1899         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1900 #else
1901         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1902         if (icmp6 == NULL) {
1903                 /* m is already reclaimed */
1904                 return (IPPROTO_DONE);
1905         }
1906 #endif
1907
1908         /*
1909          * XXX: the address may have embedded scope zone ID, which should be
1910          * hidden from applications.
1911          */
1912         bzero(&fromsa, sizeof(fromsa));
1913         fromsa.sin6_family = AF_INET6;
1914         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1915         fromsa.sin6_addr = ip6->ip6_src;
1916         if (sa6_recoverscope(&fromsa)) {
1917                 m_freem(m);
1918                 return (IPPROTO_DONE);
1919         }
1920
1921         INP_INFO_RLOCK_ET(&V_ripcbinfo, et);
1922         CK_LIST_FOREACH(in6p, &V_ripcb, inp_list) {
1923                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1924                         continue;
1925                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
1926                         continue;
1927                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1928                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1929                         continue;
1930                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1931                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1932                         continue;
1933                 INP_RLOCK(in6p);
1934                 if (__predict_false(in6p->inp_flags2 & INP_FREED)) {
1935                         INP_RUNLOCK(in6p);
1936                         continue;
1937                 }
1938                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1939                     in6p->in6p_icmp6filt)) {
1940                         INP_RUNLOCK(in6p);
1941                         continue;
1942                 }
1943                 if (last != NULL) {
1944                         struct  mbuf *n = NULL;
1945
1946                         /*
1947                          * Recent network drivers tend to allocate a single
1948                          * mbuf cluster, rather than to make a couple of
1949                          * mbufs without clusters.  Also, since the IPv6 code
1950                          * path tries to avoid m_pullup(), it is highly
1951                          * probable that we still have an mbuf cluster here
1952                          * even though the necessary length can be stored in an
1953                          * mbuf's internal buffer.
1954                          * Meanwhile, the default size of the receive socket
1955                          * buffer for raw sockets is not so large.  This means
1956                          * the possibility of packet loss is relatively higher
1957                          * than before.  To avoid this scenario, we copy the
1958                          * received data to a separate mbuf that does not use
1959                          * a cluster, if possible.
1960                          * XXX: it is better to copy the data after stripping
1961                          * intermediate headers.
1962                          */
1963                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1964                             m->m_len <= MHLEN) {
1965                                 n = m_get(M_NOWAIT, m->m_type);
1966                                 if (n != NULL) {
1967                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1968                                                 bcopy(m->m_data, n->m_data,
1969                                                       m->m_len);
1970                                                 n->m_len = m->m_len;
1971                                         } else {
1972                                                 m_free(n);
1973                                                 n = NULL;
1974                                         }
1975                                 }
1976                         }
1977                         if (n != NULL ||
1978                             (n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) != NULL) {
1979                                 if (last->inp_flags & INP_CONTROLOPTS)
1980                                         ip6_savecontrol(last, n, &opts);
1981                                 /* strip intermediate headers */
1982                                 m_adj(n, off);
1983                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
1984                                 if (sbappendaddr_locked(
1985                                     &last->inp_socket->so_rcv,
1986                                     (struct sockaddr *)&fromsa, n, opts)
1987                                     == 0) {
1988                                         /* should notify about lost packet */
1989                                         m_freem(n);
1990                                         if (opts) {
1991                                                 m_freem(opts);
1992                                         }
1993                                         SOCKBUF_UNLOCK(
1994                                             &last->inp_socket->so_rcv);
1995                                 } else
1996                                         sorwakeup_locked(last->inp_socket);
1997                                 opts = NULL;
1998                         }
1999                         INP_RUNLOCK(last);
2000                 }
2001                 last = in6p;
2002         }
2003         INP_INFO_RUNLOCK_ET(&V_ripcbinfo, et);
2004         if (last != NULL) {
2005                 if (last->inp_flags & INP_CONTROLOPTS)
2006                         ip6_savecontrol(last, m, &opts);
2007                 /* strip intermediate headers */
2008                 m_adj(m, off);
2009
2010                 /* avoid using mbuf clusters if possible (see above) */
2011                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2012                     m->m_len <= MHLEN) {
2013                         struct mbuf *n;
2014
2015                         n = m_get(M_NOWAIT, m->m_type);
2016                         if (n != NULL) {
2017                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2018                                         bcopy(m->m_data, n->m_data, m->m_len);
2019                                         n->m_len = m->m_len;
2020
2021                                         m_freem(m);
2022                                         m = n;
2023                                 } else {
2024                                         m_freem(n);
2025                                         n = NULL;
2026                                 }
2027                         }
2028                 }
2029                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2030                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2031                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2032                         m_freem(m);
2033                         if (opts)
2034                                 m_freem(opts);
2035                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2036                 } else
2037                         sorwakeup_locked(last->inp_socket);
2038                 INP_RUNLOCK(last);
2039         } else {
2040                 m_freem(m);
2041                 IP6STAT_DEC(ip6s_delivered);
2042         }
2043         return IPPROTO_DONE;
2044 }
2045
2046 /*
2047  * Reflect the ip6 packet back to the source.
2048  * OFF points to the icmp6 header, counted from the top of the mbuf.
2049  */
2050 void
2051 icmp6_reflect(struct mbuf *m, size_t off)
2052 {
2053         struct in6_addr src6, *srcp;
2054         struct ip6_hdr *ip6;
2055         struct icmp6_hdr *icmp6;
2056         struct in6_ifaddr *ia = NULL;
2057         struct ifnet *outif = NULL;
2058         int plen;
2059         int type, code, hlim;
2060
2061         /* too short to reflect */
2062         if (off < sizeof(struct ip6_hdr)) {
2063                 nd6log((LOG_DEBUG,
2064                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2065                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2066                     __FILE__, __LINE__));
2067                 goto bad;
2068         }
2069
2070         /*
2071          * If there are extra headers between IPv6 and ICMPv6, strip
2072          * off that header first.
2073          */
2074 #ifdef DIAGNOSTIC
2075         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2076                 panic("assumption failed in icmp6_reflect");
2077 #endif
2078         if (off > sizeof(struct ip6_hdr)) {
2079                 size_t l;
2080                 struct ip6_hdr nip6;
2081
2082                 l = off - sizeof(struct ip6_hdr);
2083                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2084                 m_adj(m, l);
2085                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2086                 if (m->m_len < l) {
2087                         if ((m = m_pullup(m, l)) == NULL)
2088                                 return;
2089                 }
2090                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2091         } else /* off == sizeof(struct ip6_hdr) */ {
2092                 size_t 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         }
2099         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2100         ip6 = mtod(m, struct ip6_hdr *);
2101         ip6->ip6_nxt = IPPROTO_ICMPV6;
2102         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2103         type = icmp6->icmp6_type; /* keep type for statistics */
2104         code = icmp6->icmp6_code; /* ditto. */
2105         hlim = 0;
2106         srcp = NULL;
2107
2108         /*
2109          * If the incoming packet was addressed directly to us (i.e. unicast),
2110          * use dst as the src for the reply.
2111          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2112          * (for example) when we encounter an error while forwarding procedure
2113          * destined to a duplicated address of ours.
2114          */
2115         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2116                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */);
2117                 if (ia != NULL && !(ia->ia6_flags &
2118                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2119                         src6 = ia->ia_addr.sin6_addr;
2120                         srcp = &src6;
2121
2122                         if (m->m_pkthdr.rcvif != NULL) {
2123                                 /* XXX: This may not be the outgoing interface */
2124                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2125                         } else
2126                                 hlim = V_ip6_defhlim;
2127                 }
2128                 if (ia != NULL)
2129                         ifa_free(&ia->ia_ifa);
2130         }
2131
2132         if (srcp == NULL) {
2133                 int error;
2134                 struct in6_addr dst6;
2135                 uint32_t scopeid;
2136
2137                 /*
2138                  * This case matches to multicasts, our anycast, or unicasts
2139                  * that we do not own.  Select a source address based on the
2140                  * source address of the erroneous packet.
2141                  */
2142                 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2143                 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2144                     scopeid, NULL, &src6, &hlim);
2145
2146                 if (error) {
2147                         char ip6buf[INET6_ADDRSTRLEN];
2148                         nd6log((LOG_DEBUG,
2149                             "icmp6_reflect: source can't be determined: "
2150                             "dst=%s, error=%d\n",
2151                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2152                         goto bad;
2153                 }
2154                 srcp = &src6;
2155         }
2156         /*
2157          * ip6_input() drops a packet if its src is multicast.
2158          * So, the src is never multicast.
2159          */
2160         ip6->ip6_dst = ip6->ip6_src;
2161         ip6->ip6_src = *srcp;
2162         ip6->ip6_flow = 0;
2163         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2164         ip6->ip6_vfc |= IPV6_VERSION;
2165         ip6->ip6_nxt = IPPROTO_ICMPV6;
2166         ip6->ip6_hlim = hlim;
2167
2168         icmp6->icmp6_cksum = 0;
2169         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2170             sizeof(struct ip6_hdr), plen);
2171
2172         /*
2173          * XXX option handling
2174          */
2175
2176         m->m_flags &= ~(M_BCAST|M_MCAST);
2177         m->m_pkthdr.rcvif = NULL;
2178         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2179         if (outif)
2180                 icmp6_ifoutstat_inc(outif, type, code);
2181
2182         return;
2183
2184  bad:
2185         m_freem(m);
2186         return;
2187 }
2188
2189 void
2190 icmp6_fasttimo(void)
2191 {
2192
2193         mld_fasttimo();
2194 }
2195
2196 void
2197 icmp6_slowtimo(void)
2198 {
2199
2200         mld_slowtimo();
2201 }
2202
2203 static const char *
2204 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2205     struct in6_addr *tgt6)
2206 {
2207         static char buf[1024];
2208         char ip6bufs[INET6_ADDRSTRLEN];
2209         char ip6bufd[INET6_ADDRSTRLEN];
2210         char ip6buft[INET6_ADDRSTRLEN];
2211         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2212             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2213             ip6_sprintf(ip6buft, tgt6));
2214         return buf;
2215 }
2216
2217 void
2218 icmp6_redirect_input(struct mbuf *m, int off)
2219 {
2220         struct ifnet *ifp;
2221         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2222         struct nd_redirect *nd_rd;
2223         int icmp6len = ntohs(ip6->ip6_plen);
2224         char *lladdr = NULL;
2225         int lladdrlen = 0;
2226         int is_router;
2227         int is_onlink;
2228         struct in6_addr src6 = ip6->ip6_src;
2229         struct in6_addr redtgt6;
2230         struct in6_addr reddst6;
2231         union nd_opts ndopts;
2232         char ip6buf[INET6_ADDRSTRLEN];
2233
2234         M_ASSERTPKTHDR(m);
2235         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2236
2237         ifp = m->m_pkthdr.rcvif;
2238
2239         /* XXX if we are router, we don't update route by icmp6 redirect */
2240         if (V_ip6_forwarding)
2241                 goto freeit;
2242         if (!V_icmp6_rediraccept)
2243                 goto freeit;
2244
2245         /* RFC 6980: Nodes MUST silently ignore fragments */
2246         if(m->m_flags & M_FRAGMENTED)
2247                 goto freeit;
2248
2249 #ifndef PULLDOWN_TEST
2250         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2251         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2252 #else
2253         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2254         if (nd_rd == NULL) {
2255                 ICMP6STAT_INC(icp6s_tooshort);
2256                 return;
2257         }
2258 #endif
2259         redtgt6 = nd_rd->nd_rd_target;
2260         reddst6 = nd_rd->nd_rd_dst;
2261
2262         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2263             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2264                 goto freeit;
2265         }
2266
2267         /* validation */
2268         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2269                 nd6log((LOG_ERR,
2270                     "ICMP6 redirect sent from %s rejected; "
2271                     "must be from linklocal\n",
2272                     ip6_sprintf(ip6buf, &src6)));
2273                 goto bad;
2274         }
2275         if (ip6->ip6_hlim != 255) {
2276                 nd6log((LOG_ERR,
2277                     "ICMP6 redirect sent from %s rejected; "
2278                     "hlim=%d (must be 255)\n",
2279                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2280                 goto bad;
2281         }
2282     {
2283         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2284         struct nhop6_basic nh6;
2285         struct in6_addr kdst;
2286         uint32_t scopeid;
2287
2288         in6_splitscope(&reddst6, &kdst, &scopeid);
2289         if (fib6_lookup_nh_basic(ifp->if_fib, &kdst, scopeid, 0, 0,&nh6)==0){
2290                 if ((nh6.nh_flags & NHF_GATEWAY) == 0) {
2291                         nd6log((LOG_ERR,
2292                             "ICMP6 redirect rejected; no route "
2293                             "with inet6 gateway found for redirect dst: %s\n",
2294                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2295                         goto bad;
2296                 }
2297
2298                 /*
2299                  * Embed scope zone id into next hop address, since
2300                  * fib6_lookup_nh_basic() returns address without embedded
2301                  * scope zone id.
2302                  */
2303                 if (in6_setscope(&nh6.nh_addr, m->m_pkthdr.rcvif, NULL))
2304                         goto freeit;
2305
2306                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh6.nh_addr) == 0) {
2307                         nd6log((LOG_ERR,
2308                             "ICMP6 redirect rejected; "
2309                             "not equal to gw-for-src=%s (must be same): "
2310                             "%s\n",
2311                             ip6_sprintf(ip6buf, &nh6.nh_addr),
2312                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2313                         goto bad;
2314                 }
2315         } else {
2316                 nd6log((LOG_ERR,
2317                     "ICMP6 redirect rejected; "
2318                     "no route found for redirect dst: %s\n",
2319                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2320                 goto bad;
2321         }
2322     }
2323         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2324                 nd6log((LOG_ERR,
2325                     "ICMP6 redirect rejected; "
2326                     "redirect dst must be unicast: %s\n",
2327                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2328                 goto bad;
2329         }
2330
2331         is_router = is_onlink = 0;
2332         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2333                 is_router = 1;  /* router case */
2334         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2335                 is_onlink = 1;  /* on-link destination case */
2336         if (!is_router && !is_onlink) {
2337                 nd6log((LOG_ERR,
2338                     "ICMP6 redirect rejected; "
2339                     "neither router case nor onlink case: %s\n",
2340                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2341                 goto bad;
2342         }
2343
2344         icmp6len -= sizeof(*nd_rd);
2345         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2346         if (nd6_options(&ndopts) < 0) {
2347                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2348                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2349                 /* nd6_options have incremented stats */
2350                 goto freeit;
2351         }
2352
2353         if (ndopts.nd_opts_tgt_lladdr) {
2354                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2355                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2356         }
2357
2358         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2359                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2360                     "(if %d, icmp6 packet %d): %s\n",
2361                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2362                     ifp->if_addrlen, lladdrlen - 2,
2363                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2364                 goto bad;
2365         }
2366
2367         /* Validation passed. */
2368
2369         /* RFC 2461 8.3 */
2370         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2371             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2372
2373         /*
2374          * Install a gateway route in the better-router case or an interface
2375          * route in the on-link-destination case.
2376          */
2377         {
2378                 struct sockaddr_in6 sdst;
2379                 struct sockaddr_in6 sgw;
2380                 struct sockaddr_in6 ssrc;
2381                 struct sockaddr *gw;
2382                 int rt_flags;
2383                 u_int fibnum;
2384
2385                 bzero(&sdst, sizeof(sdst));
2386                 bzero(&ssrc, sizeof(ssrc));
2387                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2388                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2389                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2390                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2391                 rt_flags = RTF_HOST;
2392                 if (is_router) {
2393                         bzero(&sgw, sizeof(sgw));
2394                         sgw.sin6_family = AF_INET6;
2395                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2396                         bcopy(&redtgt6, &sgw.sin6_addr,
2397                                 sizeof(struct in6_addr));
2398                         gw = (struct sockaddr *)&sgw;
2399                         rt_flags |= RTF_GATEWAY;
2400                 } else
2401                         gw = ifp->if_addr->ifa_addr;
2402                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2403                         in6_rtredirect((struct sockaddr *)&sdst, gw,
2404                             (struct sockaddr *)NULL, rt_flags,
2405                             (struct sockaddr *)&ssrc, fibnum);
2406         }
2407         /* finally update cached route in each socket via pfctlinput */
2408     {
2409         struct sockaddr_in6 sdst;
2410
2411         bzero(&sdst, sizeof(sdst));
2412         sdst.sin6_family = AF_INET6;
2413         sdst.sin6_len = sizeof(struct sockaddr_in6);
2414         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2415         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2416     }
2417
2418  freeit:
2419         m_freem(m);
2420         return;
2421
2422  bad:
2423         ICMP6STAT_INC(icp6s_badredirect);
2424         m_freem(m);
2425 }
2426
2427 void
2428 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2429 {
2430         struct ifnet *ifp;      /* my outgoing interface */
2431         struct in6_addr *ifp_ll6;
2432         struct in6_addr *router_ll6;
2433         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2434         struct mbuf *m = NULL;  /* newly allocated one */
2435         struct m_tag *mtag;
2436         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2437         struct nd_redirect *nd_rd;
2438         struct llentry *ln = NULL;
2439         size_t maxlen;
2440         u_char *p;
2441         struct ifnet *outif = NULL;
2442         struct sockaddr_in6 src_sa;
2443
2444         icmp6_errcount(ND_REDIRECT, 0);
2445
2446         /* if we are not router, we don't send icmp6 redirect */
2447         if (!V_ip6_forwarding)
2448                 goto fail;
2449
2450         /* sanity check */
2451         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2452                 goto fail;
2453
2454         /*
2455          * Address check:
2456          *  the source address must identify a neighbor, and
2457          *  the destination address must not be a multicast address
2458          *  [RFC 2461, sec 8.2]
2459          */
2460         sip6 = mtod(m0, struct ip6_hdr *);
2461         bzero(&src_sa, sizeof(src_sa));
2462         src_sa.sin6_family = AF_INET6;
2463         src_sa.sin6_len = sizeof(src_sa);
2464         src_sa.sin6_addr = sip6->ip6_src;
2465         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2466                 goto fail;
2467         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2468                 goto fail;      /* what should we do here? */
2469
2470         /* rate limit */
2471         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2472                 goto fail;
2473
2474         /*
2475          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2476          * we almost always ask for an mbuf cluster for simplicity.
2477          * (MHLEN < IPV6_MMTU is almost always true)
2478          */
2479 #if IPV6_MMTU >= MCLBYTES
2480 # error assumption failed about IPV6_MMTU and MCLBYTES
2481 #endif
2482         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2483         if (m == NULL)
2484                 goto fail;
2485         M_SETFIB(m, rt->rt_fibnum);
2486         maxlen = M_TRAILINGSPACE(m);
2487         maxlen = min(IPV6_MMTU, maxlen);
2488         /* just for safety */
2489         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2490             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2491                 goto fail;
2492         }
2493
2494         {
2495                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2496                 struct in6_ifaddr *ia;
2497                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2498                                                  IN6_IFF_NOTREADY|
2499                                                  IN6_IFF_ANYCAST)) == NULL)
2500                         goto fail;
2501                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2502                 /* XXXRW: reference released prematurely. */
2503                 ifa_free(&ia->ia_ifa);
2504         }
2505
2506         /* get ip6 linklocal address for the router. */
2507         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2508                 struct sockaddr_in6 *sin6;
2509                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2510                 router_ll6 = &sin6->sin6_addr;
2511                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2512                         router_ll6 = (struct in6_addr *)NULL;
2513         } else
2514                 router_ll6 = (struct in6_addr *)NULL;
2515
2516         /* ip6 */
2517         ip6 = mtod(m, struct ip6_hdr *);
2518         ip6->ip6_flow = 0;
2519         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2520         ip6->ip6_vfc |= IPV6_VERSION;
2521         /* ip6->ip6_plen will be set later */
2522         ip6->ip6_nxt = IPPROTO_ICMPV6;
2523         ip6->ip6_hlim = 255;
2524         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2525         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2526         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2527
2528         /* ND Redirect */
2529         nd_rd = (struct nd_redirect *)(ip6 + 1);
2530         nd_rd->nd_rd_type = ND_REDIRECT;
2531         nd_rd->nd_rd_code = 0;
2532         nd_rd->nd_rd_reserved = 0;
2533         if (rt->rt_flags & RTF_GATEWAY) {
2534                 /*
2535                  * nd_rd->nd_rd_target must be a link-local address in
2536                  * better router cases.
2537                  */
2538                 if (!router_ll6)
2539                         goto fail;
2540                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2541                     sizeof(nd_rd->nd_rd_target));
2542                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2543                     sizeof(nd_rd->nd_rd_dst));
2544         } else {
2545                 /* make sure redtgt == reddst */
2546                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2547                     sizeof(nd_rd->nd_rd_target));
2548                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2549                     sizeof(nd_rd->nd_rd_dst));
2550         }
2551
2552         p = (u_char *)(nd_rd + 1);
2553
2554         if (!router_ll6)
2555                 goto nolladdropt;
2556
2557         {
2558                 /* target lladdr option */
2559                 int len;
2560                 struct nd_opt_hdr *nd_opt;
2561                 char *lladdr;
2562
2563                 IF_AFDATA_RLOCK(ifp);
2564                 ln = nd6_lookup(router_ll6, 0, ifp);
2565                 IF_AFDATA_RUNLOCK(ifp);
2566                 if (ln == NULL)
2567                         goto nolladdropt;
2568
2569                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2570                 len = (len + 7) & ~7;   /* round by 8 */
2571                 /* safety check */
2572                 if (len + (p - (u_char *)ip6) > maxlen)
2573                         goto nolladdropt;
2574
2575                 if (ln->la_flags & LLE_VALID) {
2576                         nd_opt = (struct nd_opt_hdr *)p;
2577                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2578                         nd_opt->nd_opt_len = len >> 3;
2579                         lladdr = (char *)(nd_opt + 1);
2580                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2581                         p += len;
2582                 }
2583         }
2584 nolladdropt:
2585         if (ln != NULL)
2586                 LLE_RUNLOCK(ln);
2587
2588         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2589
2590         /* just to be safe */
2591 #ifdef M_DECRYPTED      /*not openbsd*/
2592         if (m0->m_flags & M_DECRYPTED)
2593                 goto noredhdropt;
2594 #endif
2595         if (p - (u_char *)ip6 > maxlen)
2596                 goto noredhdropt;
2597
2598         {
2599                 /* redirected header option */
2600                 int len;
2601                 struct nd_opt_rd_hdr *nd_opt_rh;
2602
2603                 /*
2604                  * compute the maximum size for icmp6 redirect header option.
2605                  * XXX room for auth header?
2606                  */
2607                 len = maxlen - (p - (u_char *)ip6);
2608                 len &= ~7;
2609
2610                 /* This is just for simplicity. */
2611                 if (m0->m_pkthdr.len != m0->m_len) {
2612                         if (m0->m_next) {
2613                                 m_freem(m0->m_next);
2614                                 m0->m_next = NULL;
2615                         }
2616                         m0->m_pkthdr.len = m0->m_len;
2617                 }
2618
2619                 /*
2620                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2621                  * about padding/truncate rule for the original IP packet.
2622                  * From the discussion on IPv6imp in Feb 1999,
2623                  * the consensus was:
2624                  * - "attach as much as possible" is the goal
2625                  * - pad if not aligned (original size can be guessed by
2626                  *   original ip6 header)
2627                  * Following code adds the padding if it is simple enough,
2628                  * and truncates if not.
2629                  */
2630                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2631                         panic("assumption failed in %s:%d", __FILE__,
2632                             __LINE__);
2633
2634                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2635                         /* not enough room, truncate */
2636                         m0->m_pkthdr.len = m0->m_len = len -
2637                             sizeof(*nd_opt_rh);
2638                 } else {
2639                         /* enough room, pad or truncate */
2640                         size_t extra;
2641
2642                         extra = m0->m_pkthdr.len % 8;
2643                         if (extra) {
2644                                 /* pad if easy enough, truncate if not */
2645                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2646                                         /* pad */
2647                                         m0->m_len += (8 - extra);
2648                                         m0->m_pkthdr.len += (8 - extra);
2649                                 } else {
2650                                         /* truncate */
2651                                         m0->m_pkthdr.len -= extra;
2652                                         m0->m_len -= extra;
2653                                 }
2654                         }
2655                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2656                         m0->m_pkthdr.len = m0->m_len = len -
2657                             sizeof(*nd_opt_rh);
2658                 }
2659
2660                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2661                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2662                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2663                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2664                 p += sizeof(*nd_opt_rh);
2665                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2666
2667                 /* connect m0 to m */
2668                 m_tag_delete_chain(m0, NULL);
2669                 m0->m_flags &= ~M_PKTHDR;
2670                 m->m_next = m0;
2671                 m->m_pkthdr.len = m->m_len + m0->m_len;
2672                 m0 = NULL;
2673         }
2674 noredhdropt:;
2675         if (m0) {
2676                 m_freem(m0);
2677                 m0 = NULL;
2678         }
2679
2680         /* XXX: clear embedded link IDs in the inner header */
2681         in6_clearscope(&sip6->ip6_src);
2682         in6_clearscope(&sip6->ip6_dst);
2683         in6_clearscope(&nd_rd->nd_rd_target);
2684         in6_clearscope(&nd_rd->nd_rd_dst);
2685
2686         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2687
2688         nd_rd->nd_rd_cksum = 0;
2689         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2690             sizeof(*ip6), ntohs(ip6->ip6_plen));
2691
2692         if (send_sendso_input_hook != NULL) {
2693                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2694                         M_NOWAIT);
2695                 if (mtag == NULL)
2696                         goto fail;
2697                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2698                 m_tag_prepend(m, mtag);
2699         }
2700
2701         /* send the packet to outside... */
2702         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2703         if (outif) {
2704                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2705                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2706         }
2707         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2708
2709         return;
2710
2711 fail:
2712         if (m)
2713                 m_freem(m);
2714         if (m0)
2715                 m_freem(m0);
2716 }
2717
2718 /*
2719  * ICMPv6 socket option processing.
2720  */
2721 int
2722 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2723 {
2724         int error = 0;
2725         int optlen;
2726         struct inpcb *inp = sotoinpcb(so);
2727         int level, op, optname;
2728
2729         if (sopt) {
2730                 level = sopt->sopt_level;
2731                 op = sopt->sopt_dir;
2732                 optname = sopt->sopt_name;
2733                 optlen = sopt->sopt_valsize;
2734         } else
2735                 level = op = optname = optlen = 0;
2736
2737         if (level != IPPROTO_ICMPV6) {
2738                 return EINVAL;
2739         }
2740
2741         switch (op) {
2742         case PRCO_SETOPT:
2743                 switch (optname) {
2744                 case ICMP6_FILTER:
2745                     {
2746                         struct icmp6_filter ic6f;
2747
2748                         if (optlen != sizeof(ic6f)) {
2749                                 error = EMSGSIZE;
2750                                 break;
2751                         }
2752                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2753                         if (error == 0) {
2754                                 INP_WLOCK(inp);
2755                                 *inp->in6p_icmp6filt = ic6f;
2756                                 INP_WUNLOCK(inp);
2757                         }
2758                         break;
2759                     }
2760
2761                 default:
2762                         error = ENOPROTOOPT;
2763                         break;
2764                 }
2765                 break;
2766
2767         case PRCO_GETOPT:
2768                 switch (optname) {
2769                 case ICMP6_FILTER:
2770                     {
2771                         struct icmp6_filter ic6f;
2772
2773                         INP_RLOCK(inp);
2774                         ic6f = *inp->in6p_icmp6filt;
2775                         INP_RUNLOCK(inp);
2776                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2777                         break;
2778                     }
2779
2780                 default:
2781                         error = ENOPROTOOPT;
2782                         break;
2783                 }
2784                 break;
2785         }
2786
2787         return (error);
2788 }
2789
2790 /*
2791  * Perform rate limit check.
2792  * Returns 0 if it is okay to send the icmp6 packet.
2793  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2794  * limitation.
2795  *
2796  * XXX per-destination/type check necessary?
2797  *
2798  * dst - not used at this moment
2799  * type - not used at this moment
2800  * code - not used at this moment
2801  */
2802 static int
2803 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2804     const int code)
2805 {
2806         int ret;
2807
2808         ret = 0;        /* okay to send */
2809
2810         /* PPS limit */
2811         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2812             V_icmp6errppslim)) {
2813                 /* The packet is subject to rate limit */
2814                 ret++;
2815         }
2816
2817         return ret;
2818 }