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 #define MBUF_PRIVATE    /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70
  71 #include <sys/param.h>
  72 #include <sys/domain.h>
  73 #include <sys/jail.h>
  74 #include <sys/kernel.h>
  75 #include <sys/lock.h>
  76 #include <sys/malloc.h>
  77 #include <sys/mbuf.h>
  78 #include <sys/proc.h>
  79 #include <sys/protosw.h>
  80 #include <sys/signalvar.h>
  81 #include <sys/socket.h>
  82 #include <sys/socketvar.h>
  83 #include <sys/sx.h>
  84 #include <sys/syslog.h>
  85 #include <sys/systm.h>
  86 #include <sys/time.h>
  87
  88 #include <net/if.h>
  89 #include <net/if_var.h>
  90 #include <net/if_dl.h>
  91 #include <net/if_llatbl.h>
  92 #include <net/if_private.h>
  93 #include <net/if_types.h>
  94 #include <net/route.h>
  95 #include <net/route/route_ctl.h>
  96 #include <net/route/nhop.h>
  97 #include <net/vnet.h>
  98
  99 #include <netinet/in.h>
 100 #include <netinet/in_pcb.h>
 101 #include <netinet/in_var.h>
 102 #include <netinet/ip6.h>
 103 #include <netinet/icmp6.h>
 104 #include <netinet/tcp_var.h>
 105
 106 #include <netinet6/in6_fib.h>
 107 #include <netinet6/in6_ifattach.h>
 108 #include <netinet6/in6_pcb.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 ip6proto_ctlinput_t      *ip6_ctlprotox[];
 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(int, icmp6errppslim);
 126 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0;
 127 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last);
 128 VNET_DECLARE(int, icmp6_nodeinfo);
 129
 130 #define V_ripcbinfo                     VNET(ripcbinfo)
 131 #define V_icmp6errppslim                VNET(icmp6errppslim)
 132 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 133 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 134 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 135
 136 static void icmp6_errcount(int, int);
 137 static int icmp6_rip6_input(struct mbuf **, int);
 138 static void icmp6_reflect(struct mbuf *, size_t);
 139 static const char *icmp6_redirect_diag(struct in6_addr *,
 140         struct in6_addr *, struct in6_addr *);
 141 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *);
 142 static struct mbuf *ni6_nametodns(const char *, int, int);
 143 static int ni6_dnsmatch(const char *, int, const char *, int);
 144 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 145                           struct ifnet **, struct in6_addr *);
 146 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 147                                 struct ifnet *, int);
 148 static int icmp6_notify_error(struct mbuf **, int, int);
 149
 150 /*
 151  * Kernel module interface for updating icmp6stat.  The argument is an index
 152  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 153  * general layout of icmp6stat into the caller, it doesn't encode its
 154  * location, so that future changes to add, for example, per-CPU stats
 155  * support won't cause binary compatibility problems for kernel modules.
 156  */
 157 void
 158 kmod_icmp6stat_inc(int statnum)
 159 {
 160
 161         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 162 }
 163
 164 static void
 165 icmp6_errcount(int type, int code)
 166 {
 167         switch (type) {
 168         case ICMP6_DST_UNREACH:
 169                 switch (code) {
 170                 case ICMP6_DST_UNREACH_NOROUTE:
 171                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 172                         return;
 173                 case ICMP6_DST_UNREACH_ADMIN:
 174                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 175                         return;
 176                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 177                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 178                         return;
 179                 case ICMP6_DST_UNREACH_ADDR:
 180                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 181                         return;
 182                 case ICMP6_DST_UNREACH_NOPORT:
 183                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 184                         return;
 185                 }
 186                 break;
 187         case ICMP6_PACKET_TOO_BIG:
 188                 ICMP6STAT_INC(icp6s_opacket_too_big);
 189                 return;
 190         case ICMP6_TIME_EXCEEDED:
 191                 switch (code) {
 192                 case ICMP6_TIME_EXCEED_TRANSIT:
 193                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 194                         return;
 195                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 196                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 197                         return;
 198                 }
 199                 break;
 200         case ICMP6_PARAM_PROB:
 201                 switch (code) {
 202                 case ICMP6_PARAMPROB_HEADER:
 203                         ICMP6STAT_INC(icp6s_oparamprob_header);
 204                         return;
 205                 case ICMP6_PARAMPROB_NEXTHEADER:
 206                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 207                         return;
 208                 case ICMP6_PARAMPROB_OPTION:
 209                         ICMP6STAT_INC(icp6s_oparamprob_option);
 210                         return;
 211                 }
 212                 break;
 213         case ND_REDIRECT:
 214                 ICMP6STAT_INC(icp6s_oredirect);
 215                 return;
 216         }
 217         ICMP6STAT_INC(icp6s_ounknown);
 218 }
 219
 220 /*
 221  * A wrapper function for icmp6_error() necessary when the erroneous packet
 222  * may not contain enough scope zone information.
 223  */
 224 void
 225 icmp6_error2(struct mbuf *m, int type, int code, int param,
 226     struct ifnet *ifp)
 227 {
 228         struct ip6_hdr *ip6;
 229
 230         if (ifp == NULL)
 231                 return;
 232
 233         if (m->m_len < sizeof(struct ip6_hdr)) {
 234                 m = m_pullup(m, sizeof(struct ip6_hdr));
 235                 if (m == NULL) {
 236                         IP6STAT_INC(ip6s_exthdrtoolong);
 237                         return;
 238                 }
 239         }
 240         ip6 = mtod(m, struct ip6_hdr *);
 241
 242         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 243                 return;
 244         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 245                 return;
 246
 247         icmp6_error(m, type, code, param);
 248 }
 249
 250 /*
 251  * Generate an error packet of type error in response to bad IP6 packet.
 252  */
 253 void
 254 icmp6_error(struct mbuf *m, int type, int code, int param)
 255 {
 256         struct ip6_hdr *oip6, *nip6;
 257         struct icmp6_hdr *icmp6;
 258         struct epoch_tracker et;
 259         u_int preplen;
 260         int off;
 261         int nxt;
 262
 263         ICMP6STAT_INC(icp6s_error);
 264
 265         /* count per-type-code statistics */
 266         icmp6_errcount(type, code);
 267
 268 #ifdef M_DECRYPTED      /*not openbsd*/
 269         if (m->m_flags & M_DECRYPTED) {
 270                 ICMP6STAT_INC(icp6s_canterror);
 271                 goto freeit;
 272         }
 273 #endif
 274
 275         if (m->m_len < sizeof(struct ip6_hdr)) {
 276                 m = m_pullup(m, sizeof(struct ip6_hdr));
 277                 if (m == NULL) {
 278                         IP6STAT_INC(ip6s_exthdrtoolong);
 279                         return;
 280                 }
 281         }
 282         oip6 = mtod(m, struct ip6_hdr *);
 283
 284         /*
 285          * If the destination address of the erroneous packet is a multicast
 286          * address, or the packet was sent using link-layer multicast,
 287          * we should basically suppress sending an error (RFC 2463, Section
 288          * 2.4).
 289          * We have two exceptions (the item e.2 in that section):
 290          * - the Packet Too Big message can be sent for path MTU discovery.
 291          * - the Parameter Problem Message that can be allowed an icmp6 error
 292          *   in the option type field.  This check has been done in
 293          *   ip6_unknown_opt(), so we can just check the type and code.
 294          */
 295         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 296              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 297             (type != ICMP6_PACKET_TOO_BIG &&
 298              (type != ICMP6_PARAM_PROB ||
 299               code != ICMP6_PARAMPROB_OPTION)))
 300                 goto freeit;
 301
 302         /*
 303          * RFC 2463, 2.4 (e.5): source address check.
 304          * XXX: the case of anycast source?
 305          */
 306         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 307             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 308                 goto freeit;
 309
 310         /*
 311          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 312          * don't do it.
 313          */
 314         nxt = -1;
 315         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 316         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 317                 struct icmp6_hdr *icp;
 318
 319                 if (m->m_len < off + sizeof(struct icmp6_hdr)) {
 320                         m = m_pullup(m, off + sizeof(struct icmp6_hdr));
 321                         if (m == NULL) {
 322                                 IP6STAT_INC(ip6s_exthdrtoolong);
 323                                 return;
 324                         }
 325                 }
 326                 oip6 = mtod(m, struct ip6_hdr *);
 327                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 328
 329                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 330                     icp->icmp6_type == ND_REDIRECT) {
 331                         /*
 332                          * ICMPv6 error
 333                          * Special case: for redirect (which is
 334                          * informational) we must not send icmp6 error.
 335                          */
 336                         ICMP6STAT_INC(icp6s_canterror);
 337                         goto freeit;
 338                 } else {
 339                         /* ICMPv6 informational - send the error */
 340                 }
 341         } else {
 342                 /* non-ICMPv6 - send the error */
 343         }
 344
 345         /* Finally, do rate limitation check. */
 346         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 347                 ICMP6STAT_INC(icp6s_toofreq);
 348                 goto freeit;
 349         }
 350
 351         /*
 352          * OK, ICMP6 can be generated.
 353          */
 354
 355         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 356                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 357
 358         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 359         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 360         if (m == NULL) {
 361                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 362                 return;
 363         }
 364
 365         nip6 = mtod(m, struct ip6_hdr *);
 366         nip6->ip6_src  = oip6->ip6_src;
 367         nip6->ip6_dst  = oip6->ip6_dst;
 368
 369         in6_clearscope(&oip6->ip6_src);
 370         in6_clearscope(&oip6->ip6_dst);
 371
 372         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 373         icmp6->icmp6_type = type;
 374         icmp6->icmp6_code = code;
 375         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 376
 377         ICMP6STAT_INC(icp6s_outhist[type]);
 378         NET_EPOCH_ENTER(et);
 379         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 380         NET_EPOCH_EXIT(et);
 381
 382         return;
 383
 384   freeit:
 385         /*
 386          * If we can't tell whether or not we can generate ICMP6, free it.
 387          */
 388         m_freem(m);
 389 }
 390
 391 int
 392 icmp6_errmap(const struct icmp6_hdr *icmp6)
 393 {
 394
 395         switch (icmp6->icmp6_type) {
 396         case ICMP6_DST_UNREACH:
 397                 switch (icmp6->icmp6_code) {
 398                 case ICMP6_DST_UNREACH_NOROUTE:
 399                 case ICMP6_DST_UNREACH_ADDR:
 400                         return (EHOSTUNREACH);
 401                 case ICMP6_DST_UNREACH_NOPORT:
 402                 case ICMP6_DST_UNREACH_ADMIN:
 403                         return (ECONNREFUSED);
 404                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 405                         return (ENOPROTOOPT);
 406                 default:
 407                         return (0);     /* Shouldn't happen. */
 408                 }
 409         case ICMP6_PACKET_TOO_BIG:
 410                 return (EMSGSIZE);
 411         case ICMP6_TIME_EXCEEDED:
 412                 switch (icmp6->icmp6_code) {
 413                 case ICMP6_TIME_EXCEED_TRANSIT:
 414                         return (EHOSTUNREACH);
 415                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 416                         return (0);
 417                 default:
 418                         return (0);     /* Shouldn't happen. */
 419                 }
 420         case ICMP6_PARAM_PROB:
 421                 switch (icmp6->icmp6_code) {
 422                 case ICMP6_PARAMPROB_NEXTHEADER:
 423                         return (ECONNREFUSED);
 424                 case ICMP6_PARAMPROB_HEADER:
 425                 case ICMP6_PARAMPROB_OPTION:
 426                         return (ENOPROTOOPT);
 427                 default:
 428                         return (0);     /* Shouldn't happen. */
 429                 }
 430         default:
 431                 return (0);
 432         }
 433 }
 434
 435 /*
 436  * Process a received ICMP6 message.
 437  */
 438 int
 439 icmp6_input(struct mbuf **mp, int *offp, int proto)
 440 {
 441         struct mbuf *m, *n;
 442         struct ifnet *ifp;
 443         struct ip6_hdr *ip6, *nip6;
 444         struct icmp6_hdr *icmp6, *nicmp6;
 445         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 446         int code, error, icmp6len, ip6len, noff, off, sum;
 447
 448         NET_EPOCH_ASSERT();
 449
 450         m = *mp;
 451         off = *offp;
 452
 453         if (m->m_len < off + sizeof(struct icmp6_hdr)) {
 454                 m = m_pullup(m, off + sizeof(struct icmp6_hdr));
 455                 if (m == NULL) {
 456                         IP6STAT_INC(ip6s_exthdrtoolong);
 457                         *mp = m;
 458                         return (IPPROTO_DONE);
 459                 }
 460         }
 461
 462         /*
 463          * Locate icmp6 structure in mbuf, and check
 464          * that not corrupted and of at least minimum length
 465          */
 466
 467         icmp6len = m->m_pkthdr.len - off;
 468         if (icmp6len < sizeof(struct icmp6_hdr)) {
 469                 ICMP6STAT_INC(icp6s_tooshort);
 470                 goto freeit;
 471         }
 472
 473         ip6 = mtod(m, struct ip6_hdr *);
 474         ifp = m->m_pkthdr.rcvif;
 475         /*
 476          * Check multicast group membership.
 477          * Note: SSM filters are not applied for ICMPv6 traffic.
 478          */
 479         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 480                 struct in6_multi        *inm;
 481
 482                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 483                 if (inm == NULL) {
 484                         IP6STAT_INC(ip6s_notmember);
 485                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 486                         goto freeit;
 487                 }
 488         }
 489
 490         /* Calculate the checksum. */
 491         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 492         code = icmp6->icmp6_code;
 493         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 494                 nd6log((LOG_ERR,
 495                     "ICMP6 checksum error(%d|%x) %s\n",
 496                     icmp6->icmp6_type, sum,
 497                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 498                 ICMP6STAT_INC(icp6s_checksum);
 499                 goto freeit;
 500         }
 501
 502         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 503         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 504         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 505                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 506
 507         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 508         switch (icmp6->icmp6_type) {
 509         case ICMP6_DST_UNREACH:
 510                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 511                 switch (code) {
 512                 case ICMP6_DST_UNREACH_ADMIN:
 513                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 514                 case ICMP6_DST_UNREACH_NOROUTE:
 515                 case ICMP6_DST_UNREACH_ADDR:
 516                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 517                 case ICMP6_DST_UNREACH_NOPORT:
 518                         goto deliver;
 519                 default:
 520                         goto badcode;
 521                 }
 522         case ICMP6_PACKET_TOO_BIG:
 523                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 524                 /*
 525                  * Validation is made in icmp6_mtudisc_update.
 526                  * Updating the path MTU will be done after examining
 527                  * intermediate extension headers.
 528                  */
 529                 goto deliver;
 530         case ICMP6_TIME_EXCEEDED:
 531                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 532                 switch (code) {
 533                 case ICMP6_TIME_EXCEED_TRANSIT:
 534                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 535                         goto deliver;
 536                 default:
 537                         goto badcode;
 538                 }
 539         case ICMP6_PARAM_PROB:
 540                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 541                 switch (code) {
 542                 case ICMP6_PARAMPROB_NEXTHEADER:
 543                 case ICMP6_PARAMPROB_HEADER:
 544                 case ICMP6_PARAMPROB_OPTION:
 545                         goto deliver;
 546                 default:
 547                         goto badcode;
 548                 }
 549         case ICMP6_ECHO_REQUEST:
 550                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 551                 if (code != 0)
 552                         goto badcode;
 553                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 554                         /* Give up remote */
 555                         break;
 556                 }
 557                 if (!M_WRITABLE(n)
 558                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 559                         struct mbuf *n0 = n;
 560                         int n0len;
 561
 562                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 563                         n = m_gethdr(M_NOWAIT, n0->m_type);
 564                         if (n == NULL) {
 565                                 /* Give up remote */
 566                                 m_freem(n0);
 567                                 break;
 568                         }
 569
 570                         m_move_pkthdr(n, n0);   /* FIB copied. */
 571                         n0len = n0->m_pkthdr.len;       /* save for use below */
 572                         /*
 573                          * Copy IPv6 and ICMPv6 only.
 574                          */
 575                         nip6 = mtod(n, struct ip6_hdr *);
 576                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 577                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 578                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 579                         noff = sizeof(struct ip6_hdr);
 580                         /* new mbuf contains only ipv6+icmpv6 headers */
 581                         n->m_len = noff + sizeof(struct icmp6_hdr);
 582                         /*
 583                          * Adjust mbuf.  ip6_plen will be adjusted in
 584                          * ip6_output().
 585                          */
 586                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 587                         /* recalculate complete packet size */
 588                         n->m_pkthdr.len = n0len + (noff - off);
 589                         n->m_next = n0;
 590                 } else {
 591                         if (n->m_len < off + sizeof(*nicmp6)) {
 592                                 n = m_pullup(n, off + sizeof(*nicmp6));
 593                                 if (n == NULL) {
 594                                         IP6STAT_INC(ip6s_exthdrtoolong);
 595                                         break;
 596                                 }
 597                         }
 598                         nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off);
 599                         noff = off;
 600                 }
 601                 if (n) {
 602                         nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 603                         nicmp6->icmp6_code = 0;
 604                         ICMP6STAT_INC(icp6s_reflect);
 605                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 606                         icmp6_reflect(n, noff);
 607                 }
 608                 break;
 609
 610         case ICMP6_ECHO_REPLY:
 611                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 612                 if (code != 0)
 613                         goto badcode;
 614                 break;
 615
 616         case MLD_LISTENER_QUERY:
 617         case MLD_LISTENER_REPORT:
 618         case MLD_LISTENER_DONE:
 619         case MLDV2_LISTENER_REPORT:
 620                 /*
 621                  * Drop MLD traffic which is not link-local, has a hop limit
 622                  * of greater than 1 hop, or which does not have the
 623                  * IPv6 HBH Router Alert option.
 624                  * As IPv6 HBH options are stripped in ip6_input() we must
 625                  * check an mbuf header flag.
 626                  * XXX Should we also sanity check that these messages
 627                  * were directed to a link-local multicast prefix?
 628                  */
 629                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 630                         goto freeit;
 631                 if (mld_input(&m, off, icmp6len) != 0) {
 632                         *mp = NULL;
 633                         return (IPPROTO_DONE);
 634                 }
 635                 /* m stays. */
 636                 break;
 637
 638         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 639             {
 640                 enum { WRU, FQDN } mode;
 641                 struct prison *pr;
 642
 643                 if (!V_icmp6_nodeinfo)
 644                         break;
 645
 646                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 647                         mode = WRU;
 648                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 649                         mode = FQDN;
 650                 else
 651                         goto badlen;
 652
 653                 pr = NULL;
 654                 sx_slock(&allprison_lock);
 655                 TAILQ_FOREACH(pr, &allprison, pr_list)
 656                         if (pr->pr_vnet == ifp->if_vnet)
 657                                 break;
 658                 sx_sunlock(&allprison_lock);
 659                 if (pr == NULL)
 660                         pr = curthread->td_ucred->cr_prison;
 661                 if (mode == FQDN) {
 662                         if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) {
 663                                 m = m_pullup(m, off +
 664                                     sizeof(struct icmp6_nodeinfo));
 665                                 if (m == NULL) {
 666                                         IP6STAT_INC(ip6s_exthdrtoolong);
 667                                         *mp = m;
 668                                         return (IPPROTO_DONE);
 669                                 }
 670                         }
 671                         n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 672                         if (n)
 673                                 n = ni6_input(n, off, pr);
 674                         /* XXX meaningless if n == NULL */
 675                         noff = sizeof(struct ip6_hdr);
 676                 } else {
 677                         u_char *p;
 678                         int maxhlen, hlen;
 679
 680                         /*
 681                          * XXX: this combination of flags is pointless,
 682                          * but should we keep this for compatibility?
 683                          */
 684                         if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
 685                             ICMP6_NODEINFO_TMPADDROK)) !=
 686                             (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
 687                                 break;
 688
 689                         if (code != 0)
 690                                 goto badcode;
 691
 692                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 693                         n = m_gethdr(M_NOWAIT, m->m_type);
 694                         if (n == NULL) {
 695                                 /* Give up remote */
 696                                 break;
 697                         }
 698                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 699                                 /*
 700                                  * Previous code did a blind M_COPY_PKTHDR
 701                                  * and said "just for rcvif".  If true, then
 702                                  * we could tolerate the dup failing (due to
 703                                  * the deep copy of the tag chain).  For now
 704                                  * be conservative and just fail.
 705                                  */
 706                                 m_free(n);
 707                                 n = NULL;
 708                                 break;
 709                         }
 710                         /*
 711                          * Copy IPv6 and ICMPv6 only.
 712                          */
 713                         nip6 = mtod(n, struct ip6_hdr *);
 714                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 715                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 716                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 717                         p = (u_char *)(nicmp6 + 1);
 718                         bzero(p, 4);
 719
 720                         maxhlen = M_TRAILINGSPACE(n) -
 721                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 722                         mtx_lock(&pr->pr_mtx);
 723                         hlen = strlen(pr->pr_hostname);
 724                         if (maxhlen > hlen)
 725                                 maxhlen = hlen;
 726                         /* meaningless TTL */
 727                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 728                         mtx_unlock(&pr->pr_mtx);
 729                         noff = sizeof(struct ip6_hdr);
 730                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 731                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 732                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 733                         nicmp6->icmp6_code = 0;
 734                 }
 735                 if (n) {
 736                         ICMP6STAT_INC(icp6s_reflect);
 737                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 738                         icmp6_reflect(n, noff);
 739                 }
 740                 break;
 741             }
 742
 743         case ICMP6_WRUREPLY:
 744                 if (code != 0)
 745                         goto badcode;
 746                 break;
 747
 748         case ND_ROUTER_SOLICIT:
 749                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 750                 if (code != 0)
 751                         goto badcode;
 752                 if (icmp6len < sizeof(struct nd_router_solicit))
 753                         goto badlen;
 754                 if (send_sendso_input_hook != NULL) {
 755                         if (m->m_len < off + icmp6len) {
 756                                 m = m_pullup(m, off + icmp6len);
 757                                 if (m == NULL) {
 758                                         IP6STAT_INC(ip6s_exthdrtoolong);
 759                                         *mp = NULL;
 760                                         return (IPPROTO_DONE);
 761                                 }
 762                         }
 763                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 764                         if (error == 0) {
 765                                 m = NULL;
 766                                 goto freeit;
 767                         }
 768                 }
 769                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 770                 nd6_rs_input(m, off, icmp6len);
 771                 m = n;
 772                 if (m == NULL)
 773                         goto freeit;
 774                 break;
 775
 776         case ND_ROUTER_ADVERT:
 777                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 778                 if (code != 0)
 779                         goto badcode;
 780                 if (icmp6len < sizeof(struct nd_router_advert))
 781                         goto badlen;
 782                 if (send_sendso_input_hook != NULL) {
 783                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 784                         if (error == 0) {
 785                                 m = NULL;
 786                                 goto freeit;
 787                         }
 788                 }
 789                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 790                 nd6_ra_input(m, off, icmp6len);
 791                 m = n;
 792                 if (m == NULL)
 793                         goto freeit;
 794                 break;
 795
 796         case ND_NEIGHBOR_SOLICIT:
 797                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 798                 if (code != 0)
 799                         goto badcode;
 800                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 801                         goto badlen;
 802                 if (send_sendso_input_hook != NULL) {
 803                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 804                         if (error == 0) {
 805                                 m = NULL;
 806                                 goto freeit;
 807                         }
 808                 }
 809                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 810                 nd6_ns_input(m, off, icmp6len);
 811                 m = n;
 812                 if (m == NULL)
 813                         goto freeit;
 814                 break;
 815
 816         case ND_NEIGHBOR_ADVERT:
 817                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 818                 if (code != 0)
 819                         goto badcode;
 820                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 821                         goto badlen;
 822                 if (send_sendso_input_hook != NULL) {
 823                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 824                         if (error == 0) {
 825                                 m = NULL;
 826                                 goto freeit;
 827                         }
 828                 }
 829                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 830                 nd6_na_input(m, off, icmp6len);
 831                 m = n;
 832                 if (m == NULL)
 833                         goto freeit;
 834                 break;
 835
 836         case ND_REDIRECT:
 837                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 838                 if (code != 0)
 839                         goto badcode;
 840                 if (icmp6len < sizeof(struct nd_redirect))
 841                         goto badlen;
 842                 if (send_sendso_input_hook != NULL) {
 843                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 844                         if (error == 0) {
 845                                 m = NULL;
 846                                 goto freeit;
 847                         }
 848                 }
 849                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 850                 icmp6_redirect_input(m, off);
 851                 m = n;
 852                 if (m == NULL)
 853                         goto freeit;
 854                 break;
 855
 856         case ICMP6_ROUTER_RENUMBERING:
 857                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 858                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 859                         goto badcode;
 860                 if (icmp6len < sizeof(struct icmp6_router_renum))
 861                         goto badlen;
 862                 break;
 863
 864         default:
 865                 nd6log((LOG_DEBUG,
 866                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 867                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 868                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 869                     ifp ? ifp->if_index : 0));
 870                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 871                         /* ICMPv6 error: MUST deliver it by spec... */
 872                         goto deliver;
 873                 } else {
 874                         /* ICMPv6 informational: MUST not deliver */
 875                         break;
 876                 }
 877         deliver:
 878                 if (icmp6_notify_error(&m, off, icmp6len) != 0) {
 879                         /* In this case, m should've been freed. */
 880                         *mp = NULL;
 881                         return (IPPROTO_DONE);
 882                 }
 883                 break;
 884
 885         badcode:
 886                 ICMP6STAT_INC(icp6s_badcode);
 887                 break;
 888
 889         badlen:
 890                 ICMP6STAT_INC(icp6s_badlen);
 891                 break;
 892         }
 893
 894         /* deliver the packet to appropriate sockets */
 895         icmp6_rip6_input(&m, *offp);
 896
 897         *mp = m;
 898         return (IPPROTO_DONE);
 899
 900  freeit:
 901         m_freem(m);
 902         *mp = NULL;
 903         return (IPPROTO_DONE);
 904 }
 905
 906 static int
 907 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len)
 908 {
 909         struct mbuf *m;
 910         struct icmp6_hdr *icmp6;
 911         struct ip6_hdr *eip6;
 912         u_int32_t notifymtu;
 913         struct sockaddr_in6 icmp6src, icmp6dst;
 914
 915         m = *mp;
 916
 917         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 918                 ICMP6STAT_INC(icp6s_tooshort);
 919                 goto freeit;
 920         }
 921
 922         if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) {
 923                 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr));
 924                 if (m == NULL) {
 925                         IP6STAT_INC(ip6s_exthdrtoolong);
 926                         *mp = m;
 927                         return (-1);
 928                 }
 929         }
 930         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 931         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 932         bzero(&icmp6dst, sizeof(icmp6dst));
 933
 934         /* Detect the upper level protocol */
 935         {
 936                 u_int8_t nxt = eip6->ip6_nxt;
 937                 int eoff = off + sizeof(struct icmp6_hdr) +
 938                     sizeof(struct ip6_hdr);
 939                 struct ip6ctlparam ip6cp;
 940                 int icmp6type = icmp6->icmp6_type;
 941                 struct ip6_frag *fh;
 942                 struct ip6_rthdr *rth;
 943                 struct ip6_rthdr0 *rth0;
 944                 int rthlen;
 945
 946                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 947                         struct ip6_ext *eh;
 948
 949                         switch (nxt) {
 950                         case IPPROTO_HOPOPTS:
 951                         case IPPROTO_DSTOPTS:
 952                         case IPPROTO_AH:
 953                                 if (m->m_len < eoff + sizeof(struct ip6_ext)) {
 954                                         m = m_pullup(m, eoff +
 955                                             sizeof(struct ip6_ext));
 956                                         if (m == NULL) {
 957                                                 IP6STAT_INC(ip6s_exthdrtoolong);
 958                                                 *mp = m;
 959                                                 return (-1);
 960                                         }
 961                                 }
 962                                 eh = (struct ip6_ext *)
 963                                     (mtod(m, caddr_t) + eoff);
 964                                 if (nxt == IPPROTO_AH)
 965                                         eoff += (eh->ip6e_len + 2) << 2;
 966                                 else
 967                                         eoff += (eh->ip6e_len + 1) << 3;
 968                                 nxt = eh->ip6e_nxt;
 969                                 break;
 970                         case IPPROTO_ROUTING:
 971                                 /*
 972                                  * When the erroneous packet contains a
 973                                  * routing header, we should examine the
 974                                  * header to determine the final destination.
 975                                  * Otherwise, we can't properly update
 976                                  * information that depends on the final
 977                                  * destination (e.g. path MTU).
 978                                  */
 979                                 if (m->m_len < eoff + sizeof(*rth)) {
 980                                         m = m_pullup(m, eoff + sizeof(*rth));
 981                                         if (m == NULL) {
 982                                                 IP6STAT_INC(ip6s_exthdrtoolong);
 983                                                 *mp = m;
 984                                                 return (-1);
 985                                         }
 986                                 }
 987                                 rth = (struct ip6_rthdr *)
 988                                     (mtod(m, caddr_t) + eoff);
 989                                 rthlen = (rth->ip6r_len + 1) << 3;
 990                                 /*
 991                                  * XXX: currently there is no
 992                                  * officially defined type other
 993                                  * than type-0.
 994                                  * Note that if the segment left field
 995                                  * is 0, all intermediate hops must
 996                                  * have been passed.
 997                                  */
 998                                 if (rth->ip6r_segleft &&
 999                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1000                                         int hops;
1001
1002                                         if (m->m_len < eoff + rthlen) {
1003                                                 m = m_pullup(m, eoff + rthlen);
1004                                                 if (m == NULL) {
1005                                                         IP6STAT_INC(
1006                                                             ip6s_exthdrtoolong);
1007                                                         *mp = m;
1008                                                         return (-1);
1009                                                 }
1010                                         }
1011                                         rth0 = (struct ip6_rthdr0 *)
1012                                             (mtod(m, caddr_t) + eoff);
1013
1014                                         /* just ignore a bogus header */
1015                                         if ((rth0->ip6r0_len % 2) == 0 &&
1016                                             (hops = rth0->ip6r0_len/2))
1017                                                 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1));
1018                                 }
1019                                 eoff += rthlen;
1020                                 nxt = rth->ip6r_nxt;
1021                                 break;
1022                         case IPPROTO_FRAGMENT:
1023                                 if (m->m_len < eoff + sizeof(struct ip6_frag)) {
1024                                         m = m_pullup(m, eoff +
1025                                             sizeof(struct ip6_frag));
1026                                         if (m == NULL) {
1027                                                 IP6STAT_INC(ip6s_exthdrtoolong);
1028                                                 *mp = m;
1029                                                 return (-1);
1030                                         }
1031                                 }
1032                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1033                                     eoff);
1034                                 /*
1035                                  * Data after a fragment header is meaningless
1036                                  * unless it is the first fragment, but
1037                                  * we'll go to the notify label for path MTU
1038                                  * discovery.
1039                                  */
1040                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1041                                         goto notify;
1042
1043                                 eoff += sizeof(struct ip6_frag);
1044                                 nxt = fh->ip6f_nxt;
1045                                 break;
1046                         default:
1047                                 /*
1048                                  * This case includes ESP and the No Next
1049                                  * Header.  In such cases going to the notify
1050                                  * label does not have any meaning
1051                                  * (i.e. ctlfunc will be NULL), but we go
1052                                  * anyway since we might have to update
1053                                  * path MTU information.
1054                                  */
1055                                 goto notify;
1056                         }
1057                 }
1058           notify:
1059                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1060
1061                 /*
1062                  * retrieve parameters from the inner IPv6 header, and convert
1063                  * them into sockaddr structures.
1064                  * XXX: there is no guarantee that the source or destination
1065                  * addresses of the inner packet are in the same scope as
1066                  * the addresses of the icmp packet.  But there is no other
1067                  * way to determine the zone.
1068                  */
1069                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1070
1071                 /*
1072                  * Protocol layers can't do anything useful with unspecified
1073                  * addresses.
1074                  */
1075                 if (IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_src) ||
1076                     IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_dst))
1077                         goto freeit;
1078
1079                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1080                 icmp6dst.sin6_family = AF_INET6;
1081                 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr))
1082                         icmp6dst.sin6_addr = eip6->ip6_dst;
1083                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1084                         goto freeit;
1085                 bzero(&icmp6src, sizeof(icmp6src));
1086                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1087                 icmp6src.sin6_family = AF_INET6;
1088                 icmp6src.sin6_addr = eip6->ip6_src;
1089                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1090                         goto freeit;
1091                 icmp6src.sin6_flowinfo =
1092                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1093
1094                 ip6cp.ip6c_m = m;
1095                 ip6cp.ip6c_icmp6 = icmp6;
1096                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1097                 ip6cp.ip6c_off = eoff;
1098                 ip6cp.ip6c_finaldst = &icmp6dst;
1099                 ip6cp.ip6c_src = &icmp6src;
1100                 ip6cp.ip6c_nxt = nxt;
1101
1102                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1103                         notifymtu = ntohl(icmp6->icmp6_mtu);
1104                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1105                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1106                 }
1107
1108                 if (ip6_ctlprotox[nxt] != NULL)
1109                         ip6_ctlprotox[nxt](&ip6cp);
1110         }
1111         *mp = m;
1112         return (0);
1113
1114   freeit:
1115         m_freem(m);
1116         *mp = NULL;
1117         return (-1);
1118 }
1119
1120 void
1121 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1122 {
1123         struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr;
1124         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1125         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1126         u_int mtu = ntohl(icmp6->icmp6_mtu);
1127         struct in_conninfo inc;
1128         uint32_t max_mtu;
1129
1130 #if 0
1131         /*
1132          * RFC2460 section 5, last paragraph.
1133          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1134          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1135          * due to packet translator in the middle.
1136          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1137          * special handling.
1138          */
1139         if (mtu < IPV6_MMTU)
1140                 return;
1141 #endif
1142
1143         /*
1144          * we reject ICMPv6 too big with abnormally small value.
1145          * XXX what is the good definition of "abnormally small"?
1146          */
1147         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1148                 return;
1149
1150         if (!validated)
1151                 return;
1152
1153         /*
1154          * In case the suggested mtu is less than IPV6_MMTU, we
1155          * only need to remember that it was for above mentioned
1156          * "alwaysfrag" case.
1157          * Try to be as close to the spec as possible.
1158          */
1159         if (mtu < IPV6_MMTU)
1160                 mtu = IPV6_MMTU - 8;
1161
1162         bzero(&inc, sizeof(inc));
1163         inc.inc_fibnum = M_GETFIB(m);
1164         inc.inc_flags |= INC_ISIPV6;
1165         inc.inc6_faddr = *dst;
1166         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1167                 return;
1168
1169         max_mtu = tcp_hc_getmtu(&inc);
1170         if (max_mtu == 0)
1171                 max_mtu = tcp_maxmtu6(&inc, NULL);
1172
1173         if (mtu < max_mtu) {
1174                 tcp_hc_updatemtu(&inc, mtu);
1175                 ICMP6STAT_INC(icp6s_pmtuchg);
1176         }
1177 }
1178
1179 /*
1180  * Process a Node Information Query packet, based on
1181  * draft-ietf-ipngwg-icmp-name-lookups-07.
1182  *
1183  * Spec incompatibilities:
1184  * - IPv6 Subject address handling
1185  * - IPv4 Subject address handling support missing
1186  * - Proxy reply (answer even if it's not for me)
1187  * - joins NI group address at in6_ifattach() time only, does not cope
1188  *   with hostname changes by sethostname(3)
1189  */
1190 static struct mbuf *
1191 ni6_input(struct mbuf *m, int off, struct prison *pr)
1192 {
1193         struct icmp6_nodeinfo *ni6, *nni6;
1194         struct mbuf *n = NULL;
1195         u_int16_t qtype;
1196         int subjlen;
1197         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1198         struct ni_reply_fqdn *fqdn;
1199         int addrs;              /* for NI_QTYPE_NODEADDR */
1200         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1201         struct in6_addr in6_subj; /* subject address */
1202         struct ip6_hdr *ip6;
1203         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1204         char *subj = NULL;
1205         struct in6_ifaddr *ia6 = NULL;
1206
1207         ip6 = mtod(m, struct ip6_hdr *);
1208         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1209
1210         /*
1211          * Validate IPv6 source address.
1212          * The default configuration MUST be to refuse answering queries from
1213          * global-scope addresses according to RFC4602.
1214          * Notes:
1215          *  - it's not very clear what "refuse" means; this implementation
1216          *    simply drops it.
1217          *  - it's not very easy to identify global-scope (unicast) addresses
1218          *    since there are many prefixes for them.  It should be safer
1219          *    and in practice sufficient to check "all" but loopback and
1220          *    link-local (note that site-local unicast was deprecated and
1221          *    ULA is defined as global scope-wise)
1222          */
1223         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1224             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1225             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1226                 goto bad;
1227
1228         /*
1229          * Validate IPv6 destination address.
1230          *
1231          * The Responder must discard the Query without further processing
1232          * unless it is one of the Responder's unicast or anycast addresses, or
1233          * a link-local scope multicast address which the Responder has joined.
1234          * [RFC4602, Section 5.]
1235          */
1236         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1237                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1238                         goto bad;
1239                 /* else it's a link-local multicast, fine */
1240         } else {                /* unicast or anycast */
1241                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
1242                 if (ia6 == NULL)
1243                         goto bad; /* XXX impossible */
1244
1245                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1246                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1247                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1248                                 "a temporary address in %s:%d",
1249                                __FILE__, __LINE__));
1250                         goto bad;
1251                 }
1252         }
1253
1254         /* validate query Subject field. */
1255         qtype = ntohs(ni6->ni_qtype);
1256         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1257         switch (qtype) {
1258         case NI_QTYPE_NOOP:
1259         case NI_QTYPE_SUPTYPES:
1260                 /* 07 draft */
1261                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1262                         break;
1263                 /* FALLTHROUGH */
1264         case NI_QTYPE_FQDN:
1265         case NI_QTYPE_NODEADDR:
1266         case NI_QTYPE_IPV4ADDR:
1267                 switch (ni6->ni_code) {
1268                 case ICMP6_NI_SUBJ_IPV6:
1269 #if ICMP6_NI_SUBJ_IPV6 != 0
1270                 case 0:
1271 #endif
1272                         /*
1273                          * backward compatibility - try to accept 03 draft
1274                          * format, where no Subject is present.
1275                          */
1276                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1277                             subjlen == 0) {
1278                                 oldfqdn++;
1279                                 break;
1280                         }
1281 #if ICMP6_NI_SUBJ_IPV6 != 0
1282                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1283                                 goto bad;
1284 #endif
1285
1286                         if (subjlen != sizeof(struct in6_addr))
1287                                 goto bad;
1288
1289                         /*
1290                          * Validate Subject address.
1291                          *
1292                          * Not sure what exactly "address belongs to the node"
1293                          * means in the spec, is it just unicast, or what?
1294                          *
1295                          * At this moment we consider Subject address as
1296                          * "belong to the node" if the Subject address equals
1297                          * to the IPv6 destination address; validation for
1298                          * IPv6 destination address should have done enough
1299                          * check for us.
1300                          *
1301                          * We do not do proxy at this moment.
1302                          */
1303                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1304                             subjlen, (caddr_t)&in6_subj);
1305                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1306                                 goto bad;
1307
1308                         subj = (char *)&in6_subj;
1309                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1310                                 break;
1311
1312                         /*
1313                          * XXX if we are to allow other cases, we should really
1314                          * be careful about scope here.
1315                          * basically, we should disallow queries toward IPv6
1316                          * destination X with subject Y,
1317                          * if scope(X) > scope(Y).
1318                          * if we allow scope(X) > scope(Y), it will result in
1319                          * information leakage across scope boundary.
1320                          */
1321                         goto bad;
1322
1323                 case ICMP6_NI_SUBJ_FQDN:
1324                         /*
1325                          * Validate Subject name with gethostname(3).
1326                          *
1327                          * The behavior may need some debate, since:
1328                          * - we are not sure if the node has FQDN as
1329                          *   hostname (returned by gethostname(3)).
1330                          * - the code does wildcard match for truncated names.
1331                          *   however, we are not sure if we want to perform
1332                          *   wildcard match, if gethostname(3) side has
1333                          *   truncated hostname.
1334                          */
1335                         mtx_lock(&pr->pr_mtx);
1336                         n = ni6_nametodns(pr->pr_hostname,
1337                             strlen(pr->pr_hostname), 0);
1338                         mtx_unlock(&pr->pr_mtx);
1339                         if (!n || n->m_next || n->m_len == 0)
1340                                 goto bad;
1341                         if (m->m_len < off + sizeof(struct icmp6_nodeinfo) +
1342                             subjlen) {
1343                                 m = m_pullup(m, off +
1344                                     sizeof(struct icmp6_nodeinfo) + subjlen);
1345                                 if (m == NULL) {
1346                                         IP6STAT_INC(ip6s_exthdrtoolong);
1347                                         goto bad;
1348                                 }
1349                         }
1350                         /* ip6 possibly invalid but not used after. */
1351                         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1352                         subj = (char *)(mtod(m, caddr_t) + off +
1353                             sizeof(struct icmp6_nodeinfo));
1354                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1355                             n->m_len)) {
1356                                 goto bad;
1357                         }
1358                         m_freem(n);
1359                         n = NULL;
1360                         break;
1361
1362                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1363                 default:
1364                         goto bad;
1365                 }
1366                 break;
1367         }
1368
1369         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1370         switch (qtype) {
1371         case NI_QTYPE_FQDN:
1372                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1373                         goto bad;
1374                 break;
1375         case NI_QTYPE_NODEADDR:
1376         case NI_QTYPE_IPV4ADDR:
1377                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1378                         goto bad;
1379                 break;
1380         }
1381
1382         /* guess reply length */
1383         switch (qtype) {
1384         case NI_QTYPE_NOOP:
1385                 break;          /* no reply data */
1386         case NI_QTYPE_SUPTYPES:
1387                 replylen += sizeof(u_int32_t);
1388                 break;
1389         case NI_QTYPE_FQDN:
1390                 /* XXX will append an mbuf */
1391                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1392                 break;
1393         case NI_QTYPE_NODEADDR:
1394                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1395                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1396                     sizeof(u_int32_t))) > MCLBYTES)
1397                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1398                 break;
1399         case NI_QTYPE_IPV4ADDR:
1400                 /* unsupported - should respond with unknown Qtype? */
1401                 break;
1402         default:
1403                 /*
1404                  * XXX: We must return a reply with the ICMP6 code
1405                  * `unknown Qtype' in this case.  However we regard the case
1406                  * as an FQDN query for backward compatibility.
1407                  * Older versions set a random value to this field,
1408                  * so it rarely varies in the defined qtypes.
1409                  * But the mechanism is not reliable...
1410                  * maybe we should obsolete older versions.
1411                  */
1412                 qtype = NI_QTYPE_FQDN;
1413                 /* XXX will append an mbuf */
1414                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1415                 oldfqdn++;
1416                 break;
1417         }
1418
1419         /* Allocate an mbuf to reply. */
1420         if (replylen > MCLBYTES) {
1421                 /*
1422                  * XXX: should we try to allocate more? But MCLBYTES
1423                  * is probably much larger than IPV6_MMTU...
1424                  */
1425                 goto bad;
1426         }
1427         if (replylen > MHLEN)
1428                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1429         else
1430                 n = m_gethdr(M_NOWAIT, m->m_type);
1431         if (n == NULL) {
1432                 m_freem(m);
1433                 return (NULL);
1434         }
1435         m_move_pkthdr(n, m); /* just for recvif and FIB */
1436         n->m_pkthdr.len = n->m_len = replylen;
1437
1438         /* copy mbuf header and IPv6 + Node Information base headers */
1439         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1440         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1441         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1442
1443         /* qtype dependent procedure */
1444         switch (qtype) {
1445         case NI_QTYPE_NOOP:
1446                 nni6->ni_code = ICMP6_NI_SUCCESS;
1447                 nni6->ni_flags = 0;
1448                 break;
1449         case NI_QTYPE_SUPTYPES:
1450         {
1451                 u_int32_t v;
1452                 nni6->ni_code = ICMP6_NI_SUCCESS;
1453                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1454                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1455                 v = (u_int32_t)htonl(0x0000000f);
1456                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1457                 break;
1458         }
1459         case NI_QTYPE_FQDN:
1460                 nni6->ni_code = ICMP6_NI_SUCCESS;
1461                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1462                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1463                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1464                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1465                 /*
1466                  * XXX do we really have FQDN in hostname?
1467                  */
1468                 mtx_lock(&pr->pr_mtx);
1469                 n->m_next = ni6_nametodns(pr->pr_hostname,
1470                     strlen(pr->pr_hostname), oldfqdn);
1471                 mtx_unlock(&pr->pr_mtx);
1472                 if (n->m_next == NULL)
1473                         goto bad;
1474                 /* XXX we assume that n->m_next is not a chain */
1475                 if (n->m_next->m_next != NULL)
1476                         goto bad;
1477                 n->m_pkthdr.len += n->m_next->m_len;
1478                 break;
1479         case NI_QTYPE_NODEADDR:
1480         {
1481                 int lenlim, copied;
1482
1483                 nni6->ni_code = ICMP6_NI_SUCCESS;
1484                 n->m_pkthdr.len = n->m_len =
1485                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1486                 lenlim = M_TRAILINGSPACE(n);
1487                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1488                 /* XXX: reset mbuf length */
1489                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1490                     sizeof(struct icmp6_nodeinfo) + copied;
1491                 break;
1492         }
1493         default:
1494                 break;          /* XXX impossible! */
1495         }
1496
1497         nni6->ni_type = ICMP6_NI_REPLY;
1498         m_freem(m);
1499         return (n);
1500
1501   bad:
1502         m_freem(m);
1503         if (n)
1504                 m_freem(n);
1505         return (NULL);
1506 }
1507
1508 /*
1509  * make a mbuf with DNS-encoded string.  no compression support.
1510  *
1511  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1512  * treated as truncated name (two \0 at the end).  this is a wild guess.
1513  *
1514  * old - return pascal string if non-zero
1515  */
1516 static struct mbuf *
1517 ni6_nametodns(const char *name, int namelen, int old)
1518 {
1519         struct mbuf *m;
1520         char *cp, *ep;
1521         const char *p, *q;
1522         int i, len, nterm;
1523
1524         if (old)
1525                 len = namelen + 1;
1526         else
1527                 len = MCLBYTES;
1528
1529         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1530         if (len > MLEN)
1531                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1532         else
1533                 m = m_get(M_NOWAIT, MT_DATA);
1534         if (m == NULL)
1535                 goto fail;
1536
1537         if (old) {
1538                 m->m_len = len;
1539                 *mtod(m, char *) = namelen;
1540                 bcopy(name, mtod(m, char *) + 1, namelen);
1541                 return m;
1542         } else {
1543                 m->m_len = 0;
1544                 cp = mtod(m, char *);
1545                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1546
1547                 /* if not certain about my name, return empty buffer */
1548                 if (namelen == 0)
1549                         return m;
1550
1551                 /*
1552                  * guess if it looks like shortened hostname, or FQDN.
1553                  * shortened hostname needs two trailing "\0".
1554                  */
1555                 i = 0;
1556                 for (p = name; p < name + namelen; p++) {
1557                         if (*p && *p == '.')
1558                                 i++;
1559                 }
1560                 if (i < 2)
1561                         nterm = 2;
1562                 else
1563                         nterm = 1;
1564
1565                 p = name;
1566                 while (cp < ep && p < name + namelen) {
1567                         i = 0;
1568                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1569                                 i++;
1570                         /* result does not fit into mbuf */
1571                         if (cp + i + 1 >= ep)
1572                                 goto fail;
1573                         /*
1574                          * DNS label length restriction, RFC1035 page 8.
1575                          * "i == 0" case is included here to avoid returning
1576                          * 0-length label on "foo..bar".
1577                          */
1578                         if (i <= 0 || i >= 64)
1579                                 goto fail;
1580                         *cp++ = i;
1581                         bcopy(p, cp, i);
1582                         cp += i;
1583                         p = q;
1584                         if (p < name + namelen && *p == '.')
1585                                 p++;
1586                 }
1587                 /* termination */
1588                 if (cp + nterm >= ep)
1589                         goto fail;
1590                 while (nterm-- > 0)
1591                         *cp++ = '\0';
1592                 m->m_len = cp - mtod(m, char *);
1593                 return m;
1594         }
1595
1596         panic("should not reach here");
1597         /* NOTREACHED */
1598
1599  fail:
1600         if (m)
1601                 m_freem(m);
1602         return NULL;
1603 }
1604
1605 /*
1606  * check if two DNS-encoded string matches.  takes care of truncated
1607  * form (with \0\0 at the end).  no compression support.
1608  * XXX upper/lowercase match (see RFC2065)
1609  */
1610 static int
1611 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1612 {
1613         const char *a0, *b0;
1614         int l;
1615
1616         /* simplest case - need validation? */
1617         if (alen == blen && bcmp(a, b, alen) == 0)
1618                 return 1;
1619
1620         a0 = a;
1621         b0 = b;
1622
1623         /* termination is mandatory */
1624         if (alen < 2 || blen < 2)
1625                 return 0;
1626         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1627                 return 0;
1628         alen--;
1629         blen--;
1630
1631         while (a - a0 < alen && b - b0 < blen) {
1632                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1633                         return 0;
1634
1635                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1636                         return 0;
1637                 /* we don't support compression yet */
1638                 if (a[0] >= 64 || b[0] >= 64)
1639                         return 0;
1640
1641                 /* truncated case */
1642                 if (a[0] == 0 && a - a0 == alen - 1)
1643                         return 1;
1644                 if (b[0] == 0 && b - b0 == blen - 1)
1645                         return 1;
1646                 if (a[0] == 0 || b[0] == 0)
1647                         return 0;
1648
1649                 if (a[0] != b[0])
1650                         return 0;
1651                 l = a[0];
1652                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1653                         return 0;
1654                 if (bcmp(a + 1, b + 1, l) != 0)
1655                         return 0;
1656
1657                 a += 1 + l;
1658                 b += 1 + l;
1659         }
1660
1661         if (a - a0 == alen && b - b0 == blen)
1662                 return 1;
1663         else
1664                 return 0;
1665 }
1666
1667 /*
1668  * calculate the number of addresses to be returned in the node info reply.
1669  */
1670 static int
1671 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1672     struct in6_addr *subj)
1673 {
1674         struct ifnet *ifp;
1675         struct in6_ifaddr *ifa6;
1676         struct ifaddr *ifa;
1677         int addrs = 0, addrsofif, iffound = 0;
1678         int niflags = ni6->ni_flags;
1679
1680         NET_EPOCH_ASSERT();
1681
1682         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1683                 switch (ni6->ni_code) {
1684                 case ICMP6_NI_SUBJ_IPV6:
1685                         if (subj == NULL) /* must be impossible... */
1686                                 return (0);
1687                         break;
1688                 default:
1689                         /*
1690                          * XXX: we only support IPv6 subject address for
1691                          * this Qtype.
1692                          */
1693                         return (0);
1694                 }
1695         }
1696
1697         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1698                 addrsofif = 0;
1699                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1700                         if (ifa->ifa_addr->sa_family != AF_INET6)
1701                                 continue;
1702                         ifa6 = (struct in6_ifaddr *)ifa;
1703
1704                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1705                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1706                                 iffound = 1;
1707
1708                         /*
1709                          * IPv4-mapped addresses can only be returned by a
1710                          * Node Information proxy, since they represent
1711                          * addresses of IPv4-only nodes, which perforce do
1712                          * not implement this protocol.
1713                          * [icmp-name-lookups-07, Section 5.4]
1714                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1715                          * this function at this moment.
1716                          */
1717
1718                         /* What do we have to do about ::1? */
1719                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1720                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1721                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1722                                         continue;
1723                                 break;
1724                         case IPV6_ADDR_SCOPE_SITELOCAL:
1725                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1726                                         continue;
1727                                 break;
1728                         case IPV6_ADDR_SCOPE_GLOBAL:
1729                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1730                                         continue;
1731                                 break;
1732                         default:
1733                                 continue;
1734                         }
1735
1736                         /*
1737                          * check if anycast is okay.
1738                          * XXX: just experimental.  not in the spec.
1739                          */
1740                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1741                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1742                                 continue; /* we need only unicast addresses */
1743                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1744                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1745                                 continue;
1746                         }
1747                         addrsofif++; /* count the address */
1748                 }
1749                 if (iffound) {
1750                         *ifpp = ifp;
1751                         return (addrsofif);
1752                 }
1753
1754                 addrs += addrsofif;
1755         }
1756
1757         return (addrs);
1758 }
1759
1760 static int
1761 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1762     struct ifnet *ifp0, int resid)
1763 {
1764         struct ifnet *ifp;
1765         struct in6_ifaddr *ifa6;
1766         struct ifaddr *ifa;
1767         struct ifnet *ifp_dep = NULL;
1768         int copied = 0, allow_deprecated = 0;
1769         u_char *cp = (u_char *)(nni6 + 1);
1770         int niflags = ni6->ni_flags;
1771         u_int32_t ltime;
1772
1773         NET_EPOCH_ASSERT();
1774
1775         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1776                 return (0);     /* needless to copy */
1777
1778         ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet);
1779   again:
1780
1781         for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) {
1782                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1783                         if (ifa->ifa_addr->sa_family != AF_INET6)
1784                                 continue;
1785                         ifa6 = (struct in6_ifaddr *)ifa;
1786
1787                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1788                             allow_deprecated == 0) {
1789                                 /*
1790                                  * prefererred address should be put before
1791                                  * deprecated addresses.
1792                                  */
1793
1794                                 /* record the interface for later search */
1795                                 if (ifp_dep == NULL)
1796                                         ifp_dep = ifp;
1797
1798                                 continue;
1799                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1800                             allow_deprecated != 0)
1801                                 continue; /* we now collect deprecated addrs */
1802
1803                         /* What do we have to do about ::1? */
1804                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1805                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1806                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1807                                         continue;
1808                                 break;
1809                         case IPV6_ADDR_SCOPE_SITELOCAL:
1810                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1811                                         continue;
1812                                 break;
1813                         case IPV6_ADDR_SCOPE_GLOBAL:
1814                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1815                                         continue;
1816                                 break;
1817                         default:
1818                                 continue;
1819                         }
1820
1821                         /*
1822                          * check if anycast is okay.
1823                          * XXX: just experimental.  not in the spec.
1824                          */
1825                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1826                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1827                                 continue;
1828                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1829                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1830                                 continue;
1831                         }
1832
1833                         /* now we can copy the address */
1834                         if (resid < sizeof(struct in6_addr) +
1835                             sizeof(u_int32_t)) {
1836                                 /*
1837                                  * We give up much more copy.
1838                                  * Set the truncate flag and return.
1839                                  */
1840                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1841                                 return (copied);
1842                         }
1843
1844                         /*
1845                          * Set the TTL of the address.
1846                          * The TTL value should be one of the following
1847                          * according to the specification:
1848                          *
1849                          * 1. The remaining lifetime of a DHCP lease on the
1850                          *    address, or
1851                          * 2. The remaining Valid Lifetime of a prefix from
1852                          *    which the address was derived through Stateless
1853                          *    Autoconfiguration.
1854                          *
1855                          * Note that we currently do not support stateful
1856                          * address configuration by DHCPv6, so the former
1857                          * case can't happen.
1858                          */
1859                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1860                                 ltime = ND6_INFINITE_LIFETIME;
1861                         else {
1862                                 if (ifa6->ia6_lifetime.ia6t_expire >
1863                                     time_uptime)
1864                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1865                                 else
1866                                         ltime = 0;
1867                         }
1868
1869                         bcopy(&ltime, cp, sizeof(u_int32_t));
1870                         cp += sizeof(u_int32_t);
1871
1872                         /* copy the address itself */
1873                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1874                             sizeof(struct in6_addr));
1875                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1876                         cp += sizeof(struct in6_addr);
1877
1878                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1879                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1880                 }
1881                 if (ifp0)       /* we need search only on the specified IF */
1882                         break;
1883         }
1884
1885         if (allow_deprecated == 0 && ifp_dep != NULL) {
1886                 ifp = ifp_dep;
1887                 allow_deprecated = 1;
1888
1889                 goto again;
1890         }
1891
1892         return (copied);
1893 }
1894
1895 static bool
1896 icmp6_rip6_match(const struct inpcb *inp, void *v)
1897 {
1898         struct ip6_hdr *ip6 = v;
1899
1900         if ((inp->inp_vflag & INP_IPV6) == 0)
1901                 return (false);
1902         if (inp->inp_ip_p != IPPROTO_ICMPV6)
1903                 return (false);
1904         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
1905            !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst))
1906                 return (false);
1907         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1908            !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src))
1909                 return (false);
1910         return (true);
1911 }
1912
1913 /*
1914  * XXX almost dup'ed code with rip6_input.
1915  */
1916 static int
1917 icmp6_rip6_input(struct mbuf **mp, int off)
1918 {
1919         struct mbuf *n, *m = *mp;
1920         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1921         struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo,
1922             INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6);
1923         struct inpcb *inp;
1924         struct sockaddr_in6 fromsa;
1925         struct icmp6_hdr *icmp6;
1926         struct mbuf *opts = NULL;
1927         int delivered = 0;
1928
1929         /* This is assumed to be safe; icmp6_input() does a pullup. */
1930         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1931
1932         /*
1933          * XXX: the address may have embedded scope zone ID, which should be
1934          * hidden from applications.
1935          */
1936         bzero(&fromsa, sizeof(fromsa));
1937         fromsa.sin6_family = AF_INET6;
1938         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1939         fromsa.sin6_addr = ip6->ip6_src;
1940         if (sa6_recoverscope(&fromsa)) {
1941                 m_freem(m);
1942                 *mp = NULL;
1943                 return (IPPROTO_DONE);
1944         }
1945
1946         while ((inp = inp_next(&inpi)) != NULL) {
1947                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1948                     inp->in6p_icmp6filt))
1949                         continue;
1950                 /*
1951                  * Recent network drivers tend to allocate a single
1952                  * mbuf cluster, rather than to make a couple of
1953                  * mbufs without clusters.  Also, since the IPv6 code
1954                  * path tries to avoid m_pullup(), it is highly
1955                  * probable that we still have an mbuf cluster here
1956                  * even though the necessary length can be stored in an
1957                  * mbuf's internal buffer.
1958                  * Meanwhile, the default size of the receive socket
1959                  * buffer for raw sockets is not so large.  This means
1960                  * the possibility of packet loss is relatively higher
1961                  * than before.  To avoid this scenario, we copy the
1962                  * received data to a separate mbuf that does not use
1963                  * a cluster, if possible.
1964                  * XXX: it is better to copy the data after stripping
1965                  * intermediate headers.
1966                  */
1967                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1968                     m->m_len <= MHLEN) {
1969                         n = m_get(M_NOWAIT, m->m_type);
1970                         if (n != NULL) {
1971                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1972                                         bcopy(m->m_data, n->m_data, m->m_len);
1973                                         n->m_len = m->m_len;
1974                                 } else {
1975                                         m_free(n);
1976                                         n = NULL;
1977                                 }
1978                         }
1979                 } else
1980                         n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
1981                 if (n == NULL)
1982                         continue;
1983                 if (inp->inp_flags & INP_CONTROLOPTS)
1984                         ip6_savecontrol(inp, n, &opts);
1985                 /* strip intermediate headers */
1986                 m_adj(n, off);
1987                 SOCKBUF_LOCK(&inp->inp_socket->so_rcv);
1988                 if (sbappendaddr_locked(&inp->inp_socket->so_rcv,
1989                     (struct sockaddr *)&fromsa, n, opts) == 0) {
1990                         soroverflow_locked(inp->inp_socket);
1991                         m_freem(n);
1992                         if (opts)
1993                                 m_freem(opts);
1994                 } else {
1995                         sorwakeup_locked(inp->inp_socket);
1996                         delivered++;
1997                 }
1998                 opts = NULL;
1999         }
2000         m_freem(m);
2001         *mp = NULL;
2002         if (delivered == 0)
2003                 IP6STAT_DEC(ip6s_delivered);
2004         return (IPPROTO_DONE);
2005 }
2006
2007 /*
2008  * Reflect the ip6 packet back to the source.
2009  * OFF points to the icmp6 header, counted from the top of the mbuf.
2010  */
2011 static void
2012 icmp6_reflect(struct mbuf *m, size_t off)
2013 {
2014         struct in6_addr src6, *srcp;
2015         struct ip6_hdr *ip6;
2016         struct icmp6_hdr *icmp6;
2017         struct in6_ifaddr *ia = NULL;
2018         struct ifnet *outif = NULL;
2019         int plen;
2020         int type, code, hlim;
2021
2022         /* too short to reflect */
2023         if (off < sizeof(struct ip6_hdr)) {
2024                 nd6log((LOG_DEBUG,
2025                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2026                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2027                     __FILE__, __LINE__));
2028                 goto bad;
2029         }
2030
2031         /*
2032          * If there are extra headers between IPv6 and ICMPv6, strip
2033          * off that header first.
2034          */
2035 #ifdef DIAGNOSTIC
2036         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2037                 panic("assumption failed in icmp6_reflect");
2038 #endif
2039         if (off > sizeof(struct ip6_hdr)) {
2040                 size_t l;
2041                 struct ip6_hdr nip6;
2042
2043                 l = off - sizeof(struct ip6_hdr);
2044                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2045                 m_adj(m, l);
2046                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2047                 if (m->m_len < l) {
2048                         if ((m = m_pullup(m, l)) == NULL)
2049                                 return;
2050                 }
2051                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2052         } else /* off == sizeof(struct ip6_hdr) */ {
2053                 size_t l;
2054                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2055                 if (m->m_len < l) {
2056                         if ((m = m_pullup(m, l)) == NULL)
2057                                 return;
2058                 }
2059         }
2060         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2061         ip6 = mtod(m, struct ip6_hdr *);
2062         ip6->ip6_nxt = IPPROTO_ICMPV6;
2063         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2064         type = icmp6->icmp6_type; /* keep type for statistics */
2065         code = icmp6->icmp6_code; /* ditto. */
2066         hlim = 0;
2067         srcp = NULL;
2068
2069         /*
2070          * If the incoming packet was addressed directly to us (i.e. unicast),
2071          * use dst as the src for the reply.
2072          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2073          * (for example) when we encounter an error while forwarding procedure
2074          * destined to a duplicated address of ours.
2075          */
2076         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2077                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
2078                 if (ia != NULL && !(ia->ia6_flags &
2079                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2080                         src6 = ia->ia_addr.sin6_addr;
2081                         srcp = &src6;
2082
2083                         if (m->m_pkthdr.rcvif != NULL) {
2084                                 /* XXX: This may not be the outgoing interface */
2085                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2086                         } else
2087                                 hlim = V_ip6_defhlim;
2088                 }
2089         }
2090
2091         if (srcp == NULL) {
2092                 int error;
2093                 struct in6_addr dst6;
2094                 uint32_t scopeid;
2095
2096                 /*
2097                  * This case matches to multicasts, our anycast, or unicasts
2098                  * that we do not own.  Select a source address based on the
2099                  * source address of the erroneous packet.
2100                  */
2101                 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2102                 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2103                     scopeid, NULL, &src6, &hlim);
2104
2105                 if (error) {
2106                         char ip6buf[INET6_ADDRSTRLEN];
2107                         nd6log((LOG_DEBUG,
2108                             "icmp6_reflect: source can't be determined: "
2109                             "dst=%s, error=%d\n",
2110                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2111                         goto bad;
2112                 }
2113                 srcp = &src6;
2114         }
2115         /*
2116          * ip6_input() drops a packet if its src is multicast.
2117          * So, the src is never multicast.
2118          */
2119         ip6->ip6_dst = ip6->ip6_src;
2120         ip6->ip6_src = *srcp;
2121         ip6->ip6_flow = 0;
2122         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2123         ip6->ip6_vfc |= IPV6_VERSION;
2124         ip6->ip6_nxt = IPPROTO_ICMPV6;
2125         ip6->ip6_hlim = hlim;
2126
2127         icmp6->icmp6_cksum = 0;
2128         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2129             sizeof(struct ip6_hdr), plen);
2130
2131         /*
2132          * XXX option handling
2133          */
2134
2135         m->m_flags &= ~(M_BCAST|M_MCAST);
2136         m->m_pkthdr.rcvif = NULL;
2137         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2138         if (outif)
2139                 icmp6_ifoutstat_inc(outif, type, code);
2140
2141         return;
2142
2143  bad:
2144         m_freem(m);
2145         return;
2146 }
2147
2148 static const char *
2149 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2150     struct in6_addr *tgt6)
2151 {
2152         static char buf[1024];
2153         char ip6bufs[INET6_ADDRSTRLEN];
2154         char ip6bufd[INET6_ADDRSTRLEN];
2155         char ip6buft[INET6_ADDRSTRLEN];
2156         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2157             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2158             ip6_sprintf(ip6buft, tgt6));
2159         return buf;
2160 }
2161
2162 void
2163 icmp6_redirect_input(struct mbuf *m, int off)
2164 {
2165         struct ifnet *ifp;
2166         struct ip6_hdr *ip6;
2167         struct nd_redirect *nd_rd;
2168         struct in6_addr src6, redtgt6, reddst6;
2169         union nd_opts ndopts;
2170         char ip6buf[INET6_ADDRSTRLEN];
2171         char *lladdr;
2172         int icmp6len, is_onlink, is_router, lladdrlen;
2173
2174         M_ASSERTPKTHDR(m);
2175         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2176
2177         /* XXX if we are router, we don't update route by icmp6 redirect */
2178         if (V_ip6_forwarding)
2179                 goto freeit;
2180         if (!V_icmp6_rediraccept)
2181                 goto freeit;
2182
2183         /* RFC 6980: Nodes MUST silently ignore fragments */
2184         if(m->m_flags & M_FRAGMENTED)
2185                 goto freeit;
2186
2187         ip6 = mtod(m, struct ip6_hdr *);
2188         icmp6len = ntohs(ip6->ip6_plen);
2189         if (m->m_len < off + icmp6len) {
2190                 m = m_pullup(m, off + icmp6len);
2191                 if (m == NULL) {
2192                         IP6STAT_INC(ip6s_exthdrtoolong);
2193                         return;
2194                 }
2195         }
2196         ip6 = mtod(m, struct ip6_hdr *);
2197         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2198
2199         ifp = m->m_pkthdr.rcvif;
2200         redtgt6 = nd_rd->nd_rd_target;
2201         reddst6 = nd_rd->nd_rd_dst;
2202
2203         if (in6_setscope(&redtgt6, ifp, NULL) ||
2204             in6_setscope(&reddst6, ifp, NULL)) {
2205                 goto freeit;
2206         }
2207
2208         /* validation */
2209         src6 = ip6->ip6_src;
2210         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2211                 nd6log((LOG_ERR,
2212                     "ICMP6 redirect sent from %s rejected; "
2213                     "must be from linklocal\n",
2214                     ip6_sprintf(ip6buf, &src6)));
2215                 goto bad;
2216         }
2217         if (__predict_false(ip6->ip6_hlim != 255)) {
2218                 ICMP6STAT_INC(icp6s_invlhlim);
2219                 nd6log((LOG_ERR,
2220                     "ICMP6 redirect sent from %s rejected; "
2221                     "hlim=%d (must be 255)\n",
2222                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2223                 goto bad;
2224         }
2225     {
2226         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2227         struct nhop_object *nh;
2228         struct in6_addr kdst;
2229         uint32_t scopeid;
2230
2231         in6_splitscope(&reddst6, &kdst, &scopeid);
2232         NET_EPOCH_ASSERT();
2233         nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0);
2234         if (nh != NULL) {
2235                 struct in6_addr nh_addr;
2236                 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr;
2237                 if ((nh->nh_flags & NHF_GATEWAY) == 0) {
2238                         nd6log((LOG_ERR,
2239                             "ICMP6 redirect rejected; no route "
2240                             "with inet6 gateway found for redirect dst: %s\n",
2241                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2242                         goto bad;
2243                 }
2244
2245                 /*
2246                  * Embed scope zone id into next hop address.
2247                  */
2248                 nh_addr = nh->gw6_sa.sin6_addr;
2249
2250                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) {
2251                         nd6log((LOG_ERR,
2252                             "ICMP6 redirect rejected; "
2253                             "not equal to gw-for-src=%s (must be same): "
2254                             "%s\n",
2255                             ip6_sprintf(ip6buf, &nh_addr),
2256                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2257                         goto bad;
2258                 }
2259         } else {
2260                 nd6log((LOG_ERR,
2261                     "ICMP6 redirect rejected; "
2262                     "no route found for redirect dst: %s\n",
2263                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2264                 goto bad;
2265         }
2266     }
2267         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2268                 nd6log((LOG_ERR,
2269                     "ICMP6 redirect rejected; "
2270                     "redirect dst must be unicast: %s\n",
2271                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2272                 goto bad;
2273         }
2274
2275         is_router = is_onlink = 0;
2276         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2277                 is_router = 1;  /* router case */
2278         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2279                 is_onlink = 1;  /* on-link destination case */
2280         if (!is_router && !is_onlink) {
2281                 nd6log((LOG_ERR,
2282                     "ICMP6 redirect rejected; "
2283                     "neither router case nor onlink case: %s\n",
2284                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2285                 goto bad;
2286         }
2287
2288         icmp6len -= sizeof(*nd_rd);
2289         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2290         if (nd6_options(&ndopts) < 0) {
2291                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2292                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2293                 /* nd6_options have incremented stats */
2294                 goto freeit;
2295         }
2296
2297         lladdr = NULL;
2298         lladdrlen = 0;
2299         if (ndopts.nd_opts_tgt_lladdr) {
2300                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2301                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2302         }
2303
2304         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2305                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2306                     "(if %d, icmp6 packet %d): %s\n",
2307                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2308                     ifp->if_addrlen, lladdrlen - 2,
2309                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2310                 goto bad;
2311         }
2312
2313         /* Validation passed. */
2314
2315         /* RFC 2461 8.3 */
2316         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2317             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2318
2319         /*
2320          * Install a gateway route in the better-router case or an interface
2321          * route in the on-link-destination case.
2322          */
2323         {
2324                 struct sockaddr_in6 sdst;
2325                 struct sockaddr_in6 sgw;
2326                 struct sockaddr_in6 ssrc;
2327                 struct sockaddr *gw;
2328                 int rt_flags;
2329                 u_int fibnum;
2330
2331                 bzero(&sdst, sizeof(sdst));
2332                 bzero(&ssrc, sizeof(ssrc));
2333                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2334                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2335                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2336                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2337                 rt_flags = 0;
2338                 if (is_router) {
2339                         bzero(&sgw, sizeof(sgw));
2340                         sgw.sin6_family = AF_INET6;
2341                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2342                         bcopy(&redtgt6, &sgw.sin6_addr,
2343                                 sizeof(struct in6_addr));
2344                         gw = (struct sockaddr *)&sgw;
2345                         rt_flags |= RTF_GATEWAY;
2346                 } else
2347                         gw = ifp->if_addr->ifa_addr;
2348                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2349                         rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw,
2350                             (struct sockaddr *)&ssrc, ifp, rt_flags,
2351                             V_icmp6_redirtimeout);
2352         }
2353
2354  freeit:
2355         m_freem(m);
2356         return;
2357
2358  bad:
2359         ICMP6STAT_INC(icp6s_badredirect);
2360         m_freem(m);
2361 }
2362
2363 void
2364 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh)
2365 {
2366         struct ifnet *ifp;      /* my outgoing interface */
2367         struct in6_addr *ifp_ll6;
2368         struct in6_addr *router_ll6;
2369         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2370         struct mbuf *m = NULL;  /* newly allocated one */
2371         struct m_tag *mtag;
2372         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2373         struct nd_redirect *nd_rd;
2374         struct llentry *ln = NULL;
2375         size_t maxlen;
2376         u_char *p;
2377         struct ifnet *outif = NULL;
2378         struct sockaddr_in6 src_sa;
2379
2380         icmp6_errcount(ND_REDIRECT, 0);
2381
2382         /* if we are not router, we don't send icmp6 redirect */
2383         if (!V_ip6_forwarding)
2384                 goto fail;
2385
2386         /* sanity check */
2387         if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp))
2388                 goto fail;
2389
2390         /*
2391          * Address check:
2392          *  the source address must identify a neighbor, and
2393          *  the destination address must not be a multicast address
2394          *  [RFC 2461, sec 8.2]
2395          */
2396         sip6 = mtod(m0, struct ip6_hdr *);
2397         bzero(&src_sa, sizeof(src_sa));
2398         src_sa.sin6_family = AF_INET6;
2399         src_sa.sin6_len = sizeof(src_sa);
2400         src_sa.sin6_addr = sip6->ip6_src;
2401         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2402                 goto fail;
2403         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2404                 goto fail;      /* what should we do here? */
2405
2406         /* rate limit */
2407         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2408                 goto fail;
2409
2410         /*
2411          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2412          * we almost always ask for an mbuf cluster for simplicity.
2413          * (MHLEN < IPV6_MMTU is almost always true)
2414          */
2415 #if IPV6_MMTU >= MCLBYTES
2416 # error assumption failed about IPV6_MMTU and MCLBYTES
2417 #endif
2418         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2419         if (m == NULL)
2420                 goto fail;
2421         M_SETFIB(m, M_GETFIB(m0));
2422         maxlen = M_TRAILINGSPACE(m);
2423         maxlen = min(IPV6_MMTU, maxlen);
2424         /* just for safety */
2425         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2426             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2427                 goto fail;
2428         }
2429
2430         {
2431                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2432                 struct in6_ifaddr *ia;
2433                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2434                                                  IN6_IFF_NOTREADY|
2435                                                  IN6_IFF_ANYCAST)) == NULL)
2436                         goto fail;
2437                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2438                 /* XXXRW: reference released prematurely. */
2439                 ifa_free(&ia->ia_ifa);
2440         }
2441
2442         /* get ip6 linklocal address for the router. */
2443         if (nh->nh_flags & NHF_GATEWAY) {
2444                 struct sockaddr_in6 *sin6;
2445                 sin6 = &nh->gw6_sa;
2446                 router_ll6 = &sin6->sin6_addr;
2447                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2448                         router_ll6 = (struct in6_addr *)NULL;
2449         } else
2450                 router_ll6 = (struct in6_addr *)NULL;
2451
2452         /* ip6 */
2453         ip6 = mtod(m, struct ip6_hdr *);
2454         ip6->ip6_flow = 0;
2455         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2456         ip6->ip6_vfc |= IPV6_VERSION;
2457         /* ip6->ip6_plen will be set later */
2458         ip6->ip6_nxt = IPPROTO_ICMPV6;
2459         ip6->ip6_hlim = 255;
2460         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2461         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2462         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2463
2464         /* ND Redirect */
2465         nd_rd = (struct nd_redirect *)(ip6 + 1);
2466         nd_rd->nd_rd_type = ND_REDIRECT;
2467         nd_rd->nd_rd_code = 0;
2468         nd_rd->nd_rd_reserved = 0;
2469         if (nh->nh_flags & NHF_GATEWAY) {
2470                 /*
2471                  * nd_rd->nd_rd_target must be a link-local address in
2472                  * better router cases.
2473                  */
2474                 if (!router_ll6)
2475                         goto fail;
2476                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2477                     sizeof(nd_rd->nd_rd_target));
2478                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2479                     sizeof(nd_rd->nd_rd_dst));
2480         } else {
2481                 /* make sure redtgt == reddst */
2482                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2483                     sizeof(nd_rd->nd_rd_target));
2484                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2485                     sizeof(nd_rd->nd_rd_dst));
2486         }
2487
2488         p = (u_char *)(nd_rd + 1);
2489
2490         if (!router_ll6)
2491                 goto nolladdropt;
2492
2493         {
2494                 /* target lladdr option */
2495                 int len;
2496                 struct nd_opt_hdr *nd_opt;
2497                 char *lladdr;
2498
2499                 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6,  0), ifp);
2500                 if (ln == NULL)
2501                         goto nolladdropt;
2502
2503                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2504                 len = (len + 7) & ~7;   /* round by 8 */
2505                 /* safety check */
2506                 if (len + (p - (u_char *)ip6) > maxlen)
2507                         goto nolladdropt;
2508
2509                 if (ln->la_flags & LLE_VALID) {
2510                         nd_opt = (struct nd_opt_hdr *)p;
2511                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2512                         nd_opt->nd_opt_len = len >> 3;
2513                         lladdr = (char *)(nd_opt + 1);
2514                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2515                         p += len;
2516                 }
2517         }
2518 nolladdropt:
2519         if (ln != NULL)
2520                 LLE_RUNLOCK(ln);
2521
2522         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2523
2524         /* just to be safe */
2525 #ifdef M_DECRYPTED      /*not openbsd*/
2526         if (m0->m_flags & M_DECRYPTED)
2527                 goto noredhdropt;
2528 #endif
2529         if (p - (u_char *)ip6 > maxlen)
2530                 goto noredhdropt;
2531
2532         {
2533                 /* redirected header option */
2534                 int len;
2535                 struct nd_opt_rd_hdr *nd_opt_rh;
2536
2537                 /*
2538                  * compute the maximum size for icmp6 redirect header option.
2539                  * XXX room for auth header?
2540                  */
2541                 len = maxlen - (p - (u_char *)ip6);
2542                 len &= ~7;
2543
2544                 /* This is just for simplicity. */
2545                 if (m0->m_pkthdr.len != m0->m_len) {
2546                         if (m0->m_next) {
2547                                 m_freem(m0->m_next);
2548                                 m0->m_next = NULL;
2549                         }
2550                         m0->m_pkthdr.len = m0->m_len;
2551                 }
2552
2553                 /*
2554                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2555                  * about padding/truncate rule for the original IP packet.
2556                  * From the discussion on IPv6imp in Feb 1999,
2557                  * the consensus was:
2558                  * - "attach as much as possible" is the goal
2559                  * - pad if not aligned (original size can be guessed by
2560                  *   original ip6 header)
2561                  * Following code adds the padding if it is simple enough,
2562                  * and truncates if not.
2563                  */
2564                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2565                         panic("assumption failed in %s:%d", __FILE__,
2566                             __LINE__);
2567
2568                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2569                         /* not enough room, truncate */
2570                         m0->m_pkthdr.len = m0->m_len = len -
2571                             sizeof(*nd_opt_rh);
2572                 } else {
2573                         /* enough room, pad or truncate */
2574                         size_t extra;
2575
2576                         extra = m0->m_pkthdr.len % 8;
2577                         if (extra) {
2578                                 /* pad if easy enough, truncate if not */
2579                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2580                                         /* pad */
2581                                         m0->m_len += (8 - extra);
2582                                         m0->m_pkthdr.len += (8 - extra);
2583                                 } else {
2584                                         /* truncate */
2585                                         m0->m_pkthdr.len -= extra;
2586                                         m0->m_len -= extra;
2587                                 }
2588                         }
2589                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2590                         m0->m_pkthdr.len = m0->m_len = len -
2591                             sizeof(*nd_opt_rh);
2592                 }
2593
2594                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2595                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2596                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2597                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2598                 p += sizeof(*nd_opt_rh);
2599                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2600
2601                 /* connect m0 to m */
2602                 m_tag_delete_chain(m0, NULL);
2603                 m0->m_flags &= ~M_PKTHDR;
2604                 m->m_next = m0;
2605                 m->m_pkthdr.len = m->m_len + m0->m_len;
2606                 m0 = NULL;
2607         }
2608 noredhdropt:;
2609         if (m0) {
2610                 m_freem(m0);
2611                 m0 = NULL;
2612         }
2613
2614         /* XXX: clear embedded link IDs in the inner header */
2615         in6_clearscope(&sip6->ip6_src);
2616         in6_clearscope(&sip6->ip6_dst);
2617         in6_clearscope(&nd_rd->nd_rd_target);
2618         in6_clearscope(&nd_rd->nd_rd_dst);
2619
2620         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2621
2622         nd_rd->nd_rd_cksum = 0;
2623         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2624             sizeof(*ip6), ntohs(ip6->ip6_plen));
2625
2626         if (send_sendso_input_hook != NULL) {
2627                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2628                         M_NOWAIT);
2629                 if (mtag == NULL)
2630                         goto fail;
2631                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2632                 m_tag_prepend(m, mtag);
2633         }
2634
2635         /* send the packet to outside... */
2636         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2637         if (outif) {
2638                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2639                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2640         }
2641         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2642
2643         return;
2644
2645 fail:
2646         if (m)
2647                 m_freem(m);
2648         if (m0)
2649                 m_freem(m0);
2650 }
2651
2652 /*
2653  * ICMPv6 socket option processing.
2654  */
2655 int
2656 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2657 {
2658         int error = 0;
2659         int optlen;
2660         struct inpcb *inp = sotoinpcb(so);
2661         int level, op, optname;
2662
2663         if (sopt) {
2664                 level = sopt->sopt_level;
2665                 op = sopt->sopt_dir;
2666                 optname = sopt->sopt_name;
2667                 optlen = sopt->sopt_valsize;
2668         } else
2669                 level = op = optname = optlen = 0;
2670
2671         if (level != IPPROTO_ICMPV6) {
2672                 return EINVAL;
2673         }
2674
2675         switch (op) {
2676         case PRCO_SETOPT:
2677                 switch (optname) {
2678                 case ICMP6_FILTER:
2679                     {
2680                         struct icmp6_filter ic6f;
2681
2682                         if (optlen != sizeof(ic6f)) {
2683                                 error = EMSGSIZE;
2684                                 break;
2685                         }
2686                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2687                         if (error == 0) {
2688                                 INP_WLOCK(inp);
2689                                 *inp->in6p_icmp6filt = ic6f;
2690                                 INP_WUNLOCK(inp);
2691                         }
2692                         break;
2693                     }
2694
2695                 default:
2696                         error = ENOPROTOOPT;
2697                         break;
2698                 }
2699                 break;
2700
2701         case PRCO_GETOPT:
2702                 switch (optname) {
2703                 case ICMP6_FILTER:
2704                     {
2705                         struct icmp6_filter ic6f;
2706
2707                         INP_RLOCK(inp);
2708                         ic6f = *inp->in6p_icmp6filt;
2709                         INP_RUNLOCK(inp);
2710                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2711                         break;
2712                     }
2713
2714                 default:
2715                         error = ENOPROTOOPT;
2716                         break;
2717                 }
2718                 break;
2719         }
2720
2721         return (error);
2722 }
2723
2724 /*
2725  * Perform rate limit check.
2726  * Returns 0 if it is okay to send the icmp6 packet.
2727  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2728  * limitation.
2729  *
2730  * XXX per-destination/type check necessary?
2731  *
2732  * dst - not used at this moment
2733  * type - not used at this moment
2734  * code - not used at this moment
2735  */
2736 int
2737 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2738     const int code)
2739 {
2740         int ret;
2741
2742         ret = 0;        /* okay to send */
2743
2744         /* PPS limit */
2745         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2746             V_icmp6errppslim)) {
2747                 /* The packet is subject to rate limit */
2748                 ret++;
2749         }
2750
2751         return ret;
2752 }