sys/netinet6/icmp6.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
  32  */
  33
  34 /*-
  35  * Copyright (c) 1982, 1986, 1988, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  63  */
  64
  65 #include <sys/cdefs.h>
  66 __FBSDID("$FreeBSD$");
  67
  68 #define MBUF_PRIVATE    /* XXXRW: Optimisation tries to avoid M_EXT mbufs */
  69
  70 #include "opt_inet.h"
  71 #include "opt_inet6.h"
  72
  73 #include <sys/param.h>
  74 #include <sys/domain.h>
  75 #include <sys/jail.h>
  76 #include <sys/kernel.h>
  77 #include <sys/lock.h>
  78 #include <sys/malloc.h>
  79 #include <sys/mbuf.h>
  80 #include <sys/proc.h>
  81 #include <sys/protosw.h>
  82 #include <sys/signalvar.h>
  83 #include <sys/socket.h>
  84 #include <sys/socketvar.h>
  85 #include <sys/sx.h>
  86 #include <sys/syslog.h>
  87 #include <sys/systm.h>
  88 #include <sys/time.h>
  89
  90 #include <net/if.h>
  91 #include <net/if_var.h>
  92 #include <net/if_dl.h>
  93 #include <net/if_llatbl.h>
  94 #include <net/if_private.h>
  95 #include <net/if_types.h>
  96 #include <net/route.h>
  97 #include <net/route/route_ctl.h>
  98 #include <net/route/nhop.h>
  99 #include <net/vnet.h>
 100
 101 #include <netinet/in.h>
 102 #include <netinet/in_pcb.h>
 103 #include <netinet/in_var.h>
 104 #include <netinet/ip6.h>
 105 #include <netinet/icmp6.h>
 106 #include <netinet/tcp_var.h>
 107
 108 #include <netinet6/in6_fib.h>
 109 #include <netinet6/in6_ifattach.h>
 110 #include <netinet6/in6_pcb.h>
 111 #include <netinet6/ip6_var.h>
 112 #include <netinet6/scope6_var.h>
 113 #include <netinet6/mld6_var.h>
 114 #include <netinet6/nd6.h>
 115 #include <netinet6/send.h>
 116
 117 extern ip6proto_ctlinput_t      *ip6_ctlprotox[];
 118
 119 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
 120 VNET_PCPUSTAT_SYSINIT(icmp6stat);
 121
 122 #ifdef VIMAGE
 123 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
 124 #endif /* VIMAGE */
 125
 126 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 127 VNET_DECLARE(int, icmp6errppslim);
 128 VNET_DEFINE_STATIC(int, icmp6errpps_count) = 0;
 129 VNET_DEFINE_STATIC(struct timeval, icmp6errppslim_last);
 130 VNET_DECLARE(int, icmp6_nodeinfo);
 131
 132 #define V_ripcbinfo                     VNET(ripcbinfo)
 133 #define V_icmp6errppslim                VNET(icmp6errppslim)
 134 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 135 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 136 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 137
 138 static void icmp6_errcount(int, int);
 139 static int icmp6_rip6_input(struct mbuf **, int);
 140 static void icmp6_reflect(struct mbuf *, size_t);
 141 static const char *icmp6_redirect_diag(struct in6_addr *,
 142         struct in6_addr *, struct in6_addr *);
 143 static struct mbuf *ni6_input(struct mbuf *, int, struct prison *);
 144 static struct mbuf *ni6_nametodns(const char *, int, int);
 145 static int ni6_dnsmatch(const char *, int, const char *, int);
 146 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 147                           struct ifnet **, struct in6_addr *);
 148 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 149                                 struct ifnet *, int);
 150 static int icmp6_notify_error(struct mbuf **, int, int);
 151
 152 /*
 153  * Kernel module interface for updating icmp6stat.  The argument is an index
 154  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 155  * general layout of icmp6stat into the caller, it doesn't encode its
 156  * location, so that future changes to add, for example, per-CPU stats
 157  * support won't cause binary compatibility problems for kernel modules.
 158  */
 159 void
 160 kmod_icmp6stat_inc(int statnum)
 161 {
 162
 163         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 164 }
 165
 166 static void
 167 icmp6_errcount(int type, int code)
 168 {
 169         switch (type) {
 170         case ICMP6_DST_UNREACH:
 171                 switch (code) {
 172                 case ICMP6_DST_UNREACH_NOROUTE:
 173                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 174                         return;
 175                 case ICMP6_DST_UNREACH_ADMIN:
 176                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 177                         return;
 178                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 179                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 180                         return;
 181                 case ICMP6_DST_UNREACH_ADDR:
 182                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 183                         return;
 184                 case ICMP6_DST_UNREACH_NOPORT:
 185                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 186                         return;
 187                 }
 188                 break;
 189         case ICMP6_PACKET_TOO_BIG:
 190                 ICMP6STAT_INC(icp6s_opacket_too_big);
 191                 return;
 192         case ICMP6_TIME_EXCEEDED:
 193                 switch (code) {
 194                 case ICMP6_TIME_EXCEED_TRANSIT:
 195                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 196                         return;
 197                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 198                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 199                         return;
 200                 }
 201                 break;
 202         case ICMP6_PARAM_PROB:
 203                 switch (code) {
 204                 case ICMP6_PARAMPROB_HEADER:
 205                         ICMP6STAT_INC(icp6s_oparamprob_header);
 206                         return;
 207                 case ICMP6_PARAMPROB_NEXTHEADER:
 208                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 209                         return;
 210                 case ICMP6_PARAMPROB_OPTION:
 211                         ICMP6STAT_INC(icp6s_oparamprob_option);
 212                         return;
 213                 }
 214                 break;
 215         case ND_REDIRECT:
 216                 ICMP6STAT_INC(icp6s_oredirect);
 217                 return;
 218         }
 219         ICMP6STAT_INC(icp6s_ounknown);
 220 }
 221
 222 /*
 223  * A wrapper function for icmp6_error() necessary when the erroneous packet
 224  * may not contain enough scope zone information.
 225  */
 226 void
 227 icmp6_error2(struct mbuf *m, int type, int code, int param,
 228     struct ifnet *ifp)
 229 {
 230         struct ip6_hdr *ip6;
 231
 232         if (ifp == NULL)
 233                 return;
 234
 235         if (m->m_len < sizeof(struct ip6_hdr)) {
 236                 m = m_pullup(m, sizeof(struct ip6_hdr));
 237                 if (m == NULL) {
 238                         IP6STAT_INC(ip6s_exthdrtoolong);
 239                         return;
 240                 }
 241         }
 242         ip6 = mtod(m, struct ip6_hdr *);
 243
 244         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 245                 return;
 246         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 247                 return;
 248
 249         icmp6_error(m, type, code, param);
 250 }
 251
 252 /*
 253  * Generate an error packet of type error in response to bad IP6 packet.
 254  */
 255 void
 256 icmp6_error(struct mbuf *m, int type, int code, int param)
 257 {
 258         struct ip6_hdr *oip6, *nip6;
 259         struct icmp6_hdr *icmp6;
 260         struct epoch_tracker et;
 261         u_int preplen;
 262         int off;
 263         int nxt;
 264
 265         ICMP6STAT_INC(icp6s_error);
 266
 267         /* count per-type-code statistics */
 268         icmp6_errcount(type, code);
 269
 270 #ifdef M_DECRYPTED      /*not openbsd*/
 271         if (m->m_flags & M_DECRYPTED) {
 272                 ICMP6STAT_INC(icp6s_canterror);
 273                 goto freeit;
 274         }
 275 #endif
 276
 277         if (m->m_len < sizeof(struct ip6_hdr)) {
 278                 m = m_pullup(m, sizeof(struct ip6_hdr));
 279                 if (m == NULL) {
 280                         IP6STAT_INC(ip6s_exthdrtoolong);
 281                         return;
 282                 }
 283         }
 284         oip6 = mtod(m, struct ip6_hdr *);
 285
 286         /*
 287          * If the destination address of the erroneous packet is a multicast
 288          * address, or the packet was sent using link-layer multicast,
 289          * we should basically suppress sending an error (RFC 2463, Section
 290          * 2.4).
 291          * We have two exceptions (the item e.2 in that section):
 292          * - the Packet Too Big message can be sent for path MTU discovery.
 293          * - the Parameter Problem Message that can be allowed an icmp6 error
 294          *   in the option type field.  This check has been done in
 295          *   ip6_unknown_opt(), so we can just check the type and code.
 296          */
 297         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 298              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 299             (type != ICMP6_PACKET_TOO_BIG &&
 300              (type != ICMP6_PARAM_PROB ||
 301               code != ICMP6_PARAMPROB_OPTION)))
 302                 goto freeit;
 303
 304         /*
 305          * RFC 2463, 2.4 (e.5): source address check.
 306          * XXX: the case of anycast source?
 307          */
 308         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 309             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 310                 goto freeit;
 311
 312         /*
 313          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 314          * don't do it.
 315          */
 316         nxt = -1;
 317         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 318         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 319                 struct icmp6_hdr *icp;
 320
 321                 if (m->m_len < off + sizeof(struct icmp6_hdr)) {
 322                         m = m_pullup(m, off + sizeof(struct icmp6_hdr));
 323                         if (m == NULL) {
 324                                 IP6STAT_INC(ip6s_exthdrtoolong);
 325                                 return;
 326                         }
 327                 }
 328                 oip6 = mtod(m, struct ip6_hdr *);
 329                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 330
 331                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 332                     icp->icmp6_type == ND_REDIRECT) {
 333                         /*
 334                          * ICMPv6 error
 335                          * Special case: for redirect (which is
 336                          * informational) we must not send icmp6 error.
 337                          */
 338                         ICMP6STAT_INC(icp6s_canterror);
 339                         goto freeit;
 340                 } else {
 341                         /* ICMPv6 informational - send the error */
 342                 }
 343         } else {
 344                 /* non-ICMPv6 - send the error */
 345         }
 346
 347         /* Finally, do rate limitation check. */
 348         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 349                 ICMP6STAT_INC(icp6s_toofreq);
 350                 goto freeit;
 351         }
 352
 353         /*
 354          * OK, ICMP6 can be generated.
 355          */
 356
 357         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 358                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 359
 360         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 361         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 362         if (m == NULL) {
 363                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 364                 return;
 365         }
 366
 367         nip6 = mtod(m, struct ip6_hdr *);
 368         nip6->ip6_src  = oip6->ip6_src;
 369         nip6->ip6_dst  = oip6->ip6_dst;
 370
 371         in6_clearscope(&oip6->ip6_src);
 372         in6_clearscope(&oip6->ip6_dst);
 373
 374         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 375         icmp6->icmp6_type = type;
 376         icmp6->icmp6_code = code;
 377         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 378
 379         ICMP6STAT_INC(icp6s_outhist[type]);
 380         NET_EPOCH_ENTER(et);
 381         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 382         NET_EPOCH_EXIT(et);
 383
 384         return;
 385
 386   freeit:
 387         /*
 388          * If we can't tell whether or not we can generate ICMP6, free it.
 389          */
 390         m_freem(m);
 391 }
 392
 393 int
 394 icmp6_errmap(const struct icmp6_hdr *icmp6)
 395 {
 396
 397         switch (icmp6->icmp6_type) {
 398         case ICMP6_DST_UNREACH:
 399                 switch (icmp6->icmp6_code) {
 400                 case ICMP6_DST_UNREACH_NOROUTE:
 401                 case ICMP6_DST_UNREACH_ADDR:
 402                         return (EHOSTUNREACH);
 403                 case ICMP6_DST_UNREACH_NOPORT:
 404                 case ICMP6_DST_UNREACH_ADMIN:
 405                         return (ECONNREFUSED);
 406                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 407                         return (ENOPROTOOPT);
 408                 default:
 409                         return (0);     /* Shouldn't happen. */
 410                 }
 411         case ICMP6_PACKET_TOO_BIG:
 412                 return (EMSGSIZE);
 413         case ICMP6_TIME_EXCEEDED:
 414                 switch (icmp6->icmp6_code) {
 415                 case ICMP6_TIME_EXCEED_TRANSIT:
 416                         return (EHOSTUNREACH);
 417                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 418                         return (0);
 419                 default:
 420                         return (0);     /* Shouldn't happen. */
 421                 }
 422         case ICMP6_PARAM_PROB:
 423                 switch (icmp6->icmp6_code) {
 424                 case ICMP6_PARAMPROB_NEXTHEADER:
 425                         return (ECONNREFUSED);
 426                 case ICMP6_PARAMPROB_HEADER:
 427                 case ICMP6_PARAMPROB_OPTION:
 428                         return (ENOPROTOOPT);
 429                 default:
 430                         return (0);     /* Shouldn't happen. */
 431                 }
 432         default:
 433                 return (0);
 434         }
 435 }
 436
 437 /*
 438  * Process a received ICMP6 message.
 439  */
 440 int
 441 icmp6_input(struct mbuf **mp, int *offp, int proto)
 442 {
 443         struct mbuf *m, *n;
 444         struct ifnet *ifp;
 445         struct ip6_hdr *ip6, *nip6;
 446         struct icmp6_hdr *icmp6, *nicmp6;
 447         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 448         int code, error, icmp6len, ip6len, noff, off, sum;
 449
 450         NET_EPOCH_ASSERT();
 451
 452         m = *mp;
 453         off = *offp;
 454
 455         if (m->m_len < off + sizeof(struct icmp6_hdr)) {
 456                 m = m_pullup(m, off + sizeof(struct icmp6_hdr));
 457                 if (m == NULL) {
 458                         IP6STAT_INC(ip6s_exthdrtoolong);
 459                         *mp = m;
 460                         return (IPPROTO_DONE);
 461                 }
 462         }
 463
 464         /*
 465          * Locate icmp6 structure in mbuf, and check
 466          * that not corrupted and of at least minimum length
 467          */
 468
 469         icmp6len = m->m_pkthdr.len - off;
 470         if (icmp6len < sizeof(struct icmp6_hdr)) {
 471                 ICMP6STAT_INC(icp6s_tooshort);
 472                 goto freeit;
 473         }
 474
 475         ip6 = mtod(m, struct ip6_hdr *);
 476         ifp = m->m_pkthdr.rcvif;
 477         /*
 478          * Check multicast group membership.
 479          * Note: SSM filters are not applied for ICMPv6 traffic.
 480          */
 481         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 482                 struct in6_multi        *inm;
 483
 484                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 485                 if (inm == NULL) {
 486                         IP6STAT_INC(ip6s_notmember);
 487                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 488                         goto freeit;
 489                 }
 490         }
 491
 492         /* Calculate the checksum. */
 493         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 494         code = icmp6->icmp6_code;
 495         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 496                 nd6log((LOG_ERR,
 497                     "ICMP6 checksum error(%d|%x) %s\n",
 498                     icmp6->icmp6_type, sum,
 499                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 500                 ICMP6STAT_INC(icp6s_checksum);
 501                 goto freeit;
 502         }
 503
 504         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 505         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 506         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 507                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 508
 509         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 510         switch (icmp6->icmp6_type) {
 511         case ICMP6_DST_UNREACH:
 512                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 513                 switch (code) {
 514                 case ICMP6_DST_UNREACH_ADMIN:
 515                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 516                 case ICMP6_DST_UNREACH_NOROUTE:
 517                 case ICMP6_DST_UNREACH_ADDR:
 518                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 519                 case ICMP6_DST_UNREACH_NOPORT:
 520                         goto deliver;
 521                 default:
 522                         goto badcode;
 523                 }
 524         case ICMP6_PACKET_TOO_BIG:
 525                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 526                 /*
 527                  * Validation is made in icmp6_mtudisc_update.
 528                  * Updating the path MTU will be done after examining
 529                  * intermediate extension headers.
 530                  */
 531                 goto deliver;
 532         case ICMP6_TIME_EXCEEDED:
 533                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 534                 switch (code) {
 535                 case ICMP6_TIME_EXCEED_TRANSIT:
 536                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 537                         goto deliver;
 538                 default:
 539                         goto badcode;
 540                 }
 541         case ICMP6_PARAM_PROB:
 542                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 543                 switch (code) {
 544                 case ICMP6_PARAMPROB_NEXTHEADER:
 545                 case ICMP6_PARAMPROB_HEADER:
 546                 case ICMP6_PARAMPROB_OPTION:
 547                         goto deliver;
 548                 default:
 549                         goto badcode;
 550                 }
 551         case ICMP6_ECHO_REQUEST:
 552                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 553                 if (code != 0)
 554                         goto badcode;
 555                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 556                         /* Give up remote */
 557                         break;
 558                 }
 559                 if (!M_WRITABLE(n)
 560                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 561                         struct mbuf *n0 = n;
 562                         int n0len;
 563
 564                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 565                         n = m_gethdr(M_NOWAIT, n0->m_type);
 566                         if (n == NULL) {
 567                                 /* Give up remote */
 568                                 m_freem(n0);
 569                                 break;
 570                         }
 571
 572                         m_move_pkthdr(n, n0);   /* FIB copied. */
 573                         n0len = n0->m_pkthdr.len;       /* save for use below */
 574                         /*
 575                          * Copy IPv6 and ICMPv6 only.
 576                          */
 577                         nip6 = mtod(n, struct ip6_hdr *);
 578                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 579                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 580                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 581                         noff = sizeof(struct ip6_hdr);
 582                         /* new mbuf contains only ipv6+icmpv6 headers */
 583                         n->m_len = noff + sizeof(struct icmp6_hdr);
 584                         /*
 585                          * Adjust mbuf.  ip6_plen will be adjusted in
 586                          * ip6_output().
 587                          */
 588                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 589                         /* recalculate complete packet size */
 590                         n->m_pkthdr.len = n0len + (noff - off);
 591                         n->m_next = n0;
 592                 } else {
 593                         if (n->m_len < off + sizeof(*nicmp6)) {
 594                                 n = m_pullup(n, off + sizeof(*nicmp6));
 595                                 if (n == NULL) {
 596                                         IP6STAT_INC(ip6s_exthdrtoolong);
 597                                         break;
 598                                 }
 599                         }
 600                         nicmp6 = (struct icmp6_hdr *)(mtod(n, caddr_t) + off);
 601                         noff = off;
 602                 }
 603                 if (n) {
 604                         nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 605                         nicmp6->icmp6_code = 0;
 606                         ICMP6STAT_INC(icp6s_reflect);
 607                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 608                         icmp6_reflect(n, noff);
 609                 }
 610                 break;
 611
 612         case ICMP6_ECHO_REPLY:
 613                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 614                 if (code != 0)
 615                         goto badcode;
 616                 break;
 617
 618         case MLD_LISTENER_QUERY:
 619         case MLD_LISTENER_REPORT:
 620         case MLD_LISTENER_DONE:
 621         case MLDV2_LISTENER_REPORT:
 622                 /*
 623                  * Drop MLD traffic which is not link-local, has a hop limit
 624                  * of greater than 1 hop, or which does not have the
 625                  * IPv6 HBH Router Alert option.
 626                  * As IPv6 HBH options are stripped in ip6_input() we must
 627                  * check an mbuf header flag.
 628                  * XXX Should we also sanity check that these messages
 629                  * were directed to a link-local multicast prefix?
 630                  */
 631                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 632                         goto freeit;
 633                 if (mld_input(&m, off, icmp6len) != 0) {
 634                         *mp = NULL;
 635                         return (IPPROTO_DONE);
 636                 }
 637                 /* m stays. */
 638                 break;
 639
 640         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 641             {
 642                 enum { WRU, FQDN } mode;
 643                 struct prison *pr;
 644
 645                 if (!V_icmp6_nodeinfo)
 646                         break;
 647
 648                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 649                         mode = WRU;
 650                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 651                         mode = FQDN;
 652                 else
 653                         goto badlen;
 654
 655                 pr = NULL;
 656                 sx_slock(&allprison_lock);
 657                 TAILQ_FOREACH(pr, &allprison, pr_list)
 658                         if (pr->pr_vnet == ifp->if_vnet)
 659                                 break;
 660                 sx_sunlock(&allprison_lock);
 661                 if (pr == NULL)
 662                         pr = curthread->td_ucred->cr_prison;
 663                 if (mode == FQDN) {
 664                         if (m->m_len < off + sizeof(struct icmp6_nodeinfo)) {
 665                                 m = m_pullup(m, off +
 666                                     sizeof(struct icmp6_nodeinfo));
 667                                 if (m == NULL) {
 668                                         IP6STAT_INC(ip6s_exthdrtoolong);
 669                                         *mp = m;
 670                                         return (IPPROTO_DONE);
 671                                 }
 672                         }
 673                         n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 674                         if (n)
 675                                 n = ni6_input(n, off, pr);
 676                         /* XXX meaningless if n == NULL */
 677                         noff = sizeof(struct ip6_hdr);
 678                 } else {
 679                         u_char *p;
 680                         int maxhlen, hlen;
 681
 682                         /*
 683                          * XXX: this combination of flags is pointless,
 684                          * but should we keep this for compatibility?
 685                          */
 686                         if ((V_icmp6_nodeinfo & (ICMP6_NODEINFO_FQDNOK |
 687                             ICMP6_NODEINFO_TMPADDROK)) !=
 688                             (ICMP6_NODEINFO_FQDNOK | ICMP6_NODEINFO_TMPADDROK))
 689                                 break;
 690
 691                         if (code != 0)
 692                                 goto badcode;
 693
 694                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 695                         n = m_gethdr(M_NOWAIT, m->m_type);
 696                         if (n == NULL) {
 697                                 /* Give up remote */
 698                                 break;
 699                         }
 700                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 701                                 /*
 702                                  * Previous code did a blind M_COPY_PKTHDR
 703                                  * and said "just for rcvif".  If true, then
 704                                  * we could tolerate the dup failing (due to
 705                                  * the deep copy of the tag chain).  For now
 706                                  * be conservative and just fail.
 707                                  */
 708                                 m_free(n);
 709                                 n = NULL;
 710                                 break;
 711                         }
 712                         /*
 713                          * Copy IPv6 and ICMPv6 only.
 714                          */
 715                         nip6 = mtod(n, struct ip6_hdr *);
 716                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 717                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 718                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 719                         p = (u_char *)(nicmp6 + 1);
 720                         bzero(p, 4);
 721
 722                         maxhlen = M_TRAILINGSPACE(n) -
 723                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 724                         mtx_lock(&pr->pr_mtx);
 725                         hlen = strlen(pr->pr_hostname);
 726                         if (maxhlen > hlen)
 727                                 maxhlen = hlen;
 728                         /* meaningless TTL */
 729                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 730                         mtx_unlock(&pr->pr_mtx);
 731                         noff = sizeof(struct ip6_hdr);
 732                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 733                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 734                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 735                         nicmp6->icmp6_code = 0;
 736                 }
 737                 if (n) {
 738                         ICMP6STAT_INC(icp6s_reflect);
 739                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 740                         icmp6_reflect(n, noff);
 741                 }
 742                 break;
 743             }
 744
 745         case ICMP6_WRUREPLY:
 746                 if (code != 0)
 747                         goto badcode;
 748                 break;
 749
 750         case ND_ROUTER_SOLICIT:
 751                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 752                 if (code != 0)
 753                         goto badcode;
 754                 if (icmp6len < sizeof(struct nd_router_solicit))
 755                         goto badlen;
 756                 if (send_sendso_input_hook != NULL) {
 757                         if (m->m_len < off + icmp6len) {
 758                                 m = m_pullup(m, off + icmp6len);
 759                                 if (m == NULL) {
 760                                         IP6STAT_INC(ip6s_exthdrtoolong);
 761                                         *mp = NULL;
 762                                         return (IPPROTO_DONE);
 763                                 }
 764                         }
 765                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 766                         if (error == 0) {
 767                                 m = NULL;
 768                                 goto freeit;
 769                         }
 770                 }
 771                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 772                 nd6_rs_input(m, off, icmp6len);
 773                 m = n;
 774                 if (m == NULL)
 775                         goto freeit;
 776                 break;
 777
 778         case ND_ROUTER_ADVERT:
 779                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 780                 if (code != 0)
 781                         goto badcode;
 782                 if (icmp6len < sizeof(struct nd_router_advert))
 783                         goto badlen;
 784                 if (send_sendso_input_hook != NULL) {
 785                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 786                         if (error == 0) {
 787                                 m = NULL;
 788                                 goto freeit;
 789                         }
 790                 }
 791                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 792                 nd6_ra_input(m, off, icmp6len);
 793                 m = n;
 794                 if (m == NULL)
 795                         goto freeit;
 796                 break;
 797
 798         case ND_NEIGHBOR_SOLICIT:
 799                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 800                 if (code != 0)
 801                         goto badcode;
 802                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 803                         goto badlen;
 804                 if (send_sendso_input_hook != NULL) {
 805                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 806                         if (error == 0) {
 807                                 m = NULL;
 808                                 goto freeit;
 809                         }
 810                 }
 811                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 812                 nd6_ns_input(m, off, icmp6len);
 813                 m = n;
 814                 if (m == NULL)
 815                         goto freeit;
 816                 break;
 817
 818         case ND_NEIGHBOR_ADVERT:
 819                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 820                 if (code != 0)
 821                         goto badcode;
 822                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 823                         goto badlen;
 824                 if (send_sendso_input_hook != NULL) {
 825                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 826                         if (error == 0) {
 827                                 m = NULL;
 828                                 goto freeit;
 829                         }
 830                 }
 831                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 832                 nd6_na_input(m, off, icmp6len);
 833                 m = n;
 834                 if (m == NULL)
 835                         goto freeit;
 836                 break;
 837
 838         case ND_REDIRECT:
 839                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 840                 if (code != 0)
 841                         goto badcode;
 842                 if (icmp6len < sizeof(struct nd_redirect))
 843                         goto badlen;
 844                 if (send_sendso_input_hook != NULL) {
 845                         error = send_sendso_input_hook(m, ifp, SND_IN, ip6len);
 846                         if (error == 0) {
 847                                 m = NULL;
 848                                 goto freeit;
 849                         }
 850                 }
 851                 n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
 852                 icmp6_redirect_input(m, off);
 853                 m = n;
 854                 if (m == NULL)
 855                         goto freeit;
 856                 break;
 857
 858         case ICMP6_ROUTER_RENUMBERING:
 859                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 860                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 861                         goto badcode;
 862                 if (icmp6len < sizeof(struct icmp6_router_renum))
 863                         goto badlen;
 864                 break;
 865
 866         default:
 867                 nd6log((LOG_DEBUG,
 868                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 869                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 870                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 871                     ifp ? ifp->if_index : 0));
 872                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 873                         /* ICMPv6 error: MUST deliver it by spec... */
 874                         goto deliver;
 875                 } else {
 876                         /* ICMPv6 informational: MUST not deliver */
 877                         break;
 878                 }
 879         deliver:
 880                 if (icmp6_notify_error(&m, off, icmp6len) != 0) {
 881                         /* In this case, m should've been freed. */
 882                         *mp = NULL;
 883                         return (IPPROTO_DONE);
 884                 }
 885                 break;
 886
 887         badcode:
 888                 ICMP6STAT_INC(icp6s_badcode);
 889                 break;
 890
 891         badlen:
 892                 ICMP6STAT_INC(icp6s_badlen);
 893                 break;
 894         }
 895
 896         /* deliver the packet to appropriate sockets */
 897         icmp6_rip6_input(&m, *offp);
 898
 899         *mp = m;
 900         return (IPPROTO_DONE);
 901
 902  freeit:
 903         m_freem(m);
 904         *mp = NULL;
 905         return (IPPROTO_DONE);
 906 }
 907
 908 static int
 909 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len)
 910 {
 911         struct mbuf *m;
 912         struct icmp6_hdr *icmp6;
 913         struct ip6_hdr *eip6;
 914         u_int32_t notifymtu;
 915         struct sockaddr_in6 icmp6src, icmp6dst;
 916
 917         m = *mp;
 918
 919         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 920                 ICMP6STAT_INC(icp6s_tooshort);
 921                 goto freeit;
 922         }
 923
 924         if (m->m_len < off + sizeof(*icmp6) + sizeof(struct ip6_hdr)) {
 925                 m = m_pullup(m, off + sizeof(*icmp6) + sizeof(struct ip6_hdr));
 926                 if (m == NULL) {
 927                         IP6STAT_INC(ip6s_exthdrtoolong);
 928                         *mp = m;
 929                         return (-1);
 930                 }
 931         }
 932         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 933         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 934         bzero(&icmp6dst, sizeof(icmp6dst));
 935
 936         /* Detect the upper level protocol */
 937         {
 938                 u_int8_t nxt = eip6->ip6_nxt;
 939                 int eoff = off + sizeof(struct icmp6_hdr) +
 940                     sizeof(struct ip6_hdr);
 941                 struct ip6ctlparam ip6cp;
 942                 int icmp6type = icmp6->icmp6_type;
 943                 struct ip6_frag *fh;
 944                 struct ip6_rthdr *rth;
 945                 struct ip6_rthdr0 *rth0;
 946                 int rthlen;
 947
 948                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 949                         struct ip6_ext *eh;
 950
 951                         switch (nxt) {
 952                         case IPPROTO_HOPOPTS:
 953                         case IPPROTO_DSTOPTS:
 954                         case IPPROTO_AH:
 955                                 if (m->m_len < eoff + sizeof(struct ip6_ext)) {
 956                                         m = m_pullup(m, eoff +
 957                                             sizeof(struct ip6_ext));
 958                                         if (m == NULL) {
 959                                                 IP6STAT_INC(ip6s_exthdrtoolong);
 960                                                 *mp = m;
 961                                                 return (-1);
 962                                         }
 963                                 }
 964                                 eh = (struct ip6_ext *)
 965                                     (mtod(m, caddr_t) + eoff);
 966                                 if (nxt == IPPROTO_AH)
 967                                         eoff += (eh->ip6e_len + 2) << 2;
 968                                 else
 969                                         eoff += (eh->ip6e_len + 1) << 3;
 970                                 nxt = eh->ip6e_nxt;
 971                                 break;
 972                         case IPPROTO_ROUTING:
 973                                 /*
 974                                  * When the erroneous packet contains a
 975                                  * routing header, we should examine the
 976                                  * header to determine the final destination.
 977                                  * Otherwise, we can't properly update
 978                                  * information that depends on the final
 979                                  * destination (e.g. path MTU).
 980                                  */
 981                                 if (m->m_len < eoff + sizeof(*rth)) {
 982                                         m = m_pullup(m, eoff + sizeof(*rth));
 983                                         if (m == NULL) {
 984                                                 IP6STAT_INC(ip6s_exthdrtoolong);
 985                                                 *mp = m;
 986                                                 return (-1);
 987                                         }
 988                                 }
 989                                 rth = (struct ip6_rthdr *)
 990                                     (mtod(m, caddr_t) + eoff);
 991                                 rthlen = (rth->ip6r_len + 1) << 3;
 992                                 /*
 993                                  * XXX: currently there is no
 994                                  * officially defined type other
 995                                  * than type-0.
 996                                  * Note that if the segment left field
 997                                  * is 0, all intermediate hops must
 998                                  * have been passed.
 999                                  */
1000                                 if (rth->ip6r_segleft &&
1001                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1002                                         int hops;
1003
1004                                         if (m->m_len < eoff + rthlen) {
1005                                                 m = m_pullup(m, eoff + rthlen);
1006                                                 if (m == NULL) {
1007                                                         IP6STAT_INC(
1008                                                             ip6s_exthdrtoolong);
1009                                                         *mp = m;
1010                                                         return (-1);
1011                                                 }
1012                                         }
1013                                         rth0 = (struct ip6_rthdr0 *)
1014                                             (mtod(m, caddr_t) + eoff);
1015
1016                                         /* just ignore a bogus header */
1017                                         if ((rth0->ip6r0_len % 2) == 0 &&
1018                                             (hops = rth0->ip6r0_len/2))
1019                                                 icmp6dst.sin6_addr = *((struct in6_addr *)(rth0 + 1) + (hops - 1));
1020                                 }
1021                                 eoff += rthlen;
1022                                 nxt = rth->ip6r_nxt;
1023                                 break;
1024                         case IPPROTO_FRAGMENT:
1025                                 if (m->m_len < eoff + sizeof(struct ip6_frag)) {
1026                                         m = m_pullup(m, eoff +
1027                                             sizeof(struct ip6_frag));
1028                                         if (m == NULL) {
1029                                                 IP6STAT_INC(ip6s_exthdrtoolong);
1030                                                 *mp = m;
1031                                                 return (-1);
1032                                         }
1033                                 }
1034                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1035                                     eoff);
1036                                 /*
1037                                  * Data after a fragment header is meaningless
1038                                  * unless it is the first fragment, but
1039                                  * we'll go to the notify label for path MTU
1040                                  * discovery.
1041                                  */
1042                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1043                                         goto notify;
1044
1045                                 eoff += sizeof(struct ip6_frag);
1046                                 nxt = fh->ip6f_nxt;
1047                                 break;
1048                         default:
1049                                 /*
1050                                  * This case includes ESP and the No Next
1051                                  * Header.  In such cases going to the notify
1052                                  * label does not have any meaning
1053                                  * (i.e. ctlfunc will be NULL), but we go
1054                                  * anyway since we might have to update
1055                                  * path MTU information.
1056                                  */
1057                                 goto notify;
1058                         }
1059                 }
1060           notify:
1061                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1062
1063                 /*
1064                  * retrieve parameters from the inner IPv6 header, and convert
1065                  * them into sockaddr structures.
1066                  * XXX: there is no guarantee that the source or destination
1067                  * addresses of the inner packet are in the same scope as
1068                  * the addresses of the icmp packet.  But there is no other
1069                  * way to determine the zone.
1070                  */
1071                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1072
1073                 /*
1074                  * Protocol layers can't do anything useful with unspecified
1075                  * addresses.
1076                  */
1077                 if (IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_src) ||
1078                     IN6_IS_ADDR_UNSPECIFIED(&eip6->ip6_dst))
1079                         goto freeit;
1080
1081                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1082                 icmp6dst.sin6_family = AF_INET6;
1083                 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr))
1084                         icmp6dst.sin6_addr = eip6->ip6_dst;
1085                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1086                         goto freeit;
1087                 bzero(&icmp6src, sizeof(icmp6src));
1088                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1089                 icmp6src.sin6_family = AF_INET6;
1090                 icmp6src.sin6_addr = eip6->ip6_src;
1091                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1092                         goto freeit;
1093                 icmp6src.sin6_flowinfo =
1094                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1095
1096                 ip6cp.ip6c_m = m;
1097                 ip6cp.ip6c_icmp6 = icmp6;
1098                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1099                 ip6cp.ip6c_off = eoff;
1100                 ip6cp.ip6c_finaldst = &icmp6dst;
1101                 ip6cp.ip6c_src = &icmp6src;
1102                 ip6cp.ip6c_nxt = nxt;
1103
1104                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1105                         notifymtu = ntohl(icmp6->icmp6_mtu);
1106                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1107                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1108                 }
1109
1110                 if (ip6_ctlprotox[nxt] != NULL)
1111                         ip6_ctlprotox[nxt](&ip6cp);
1112         }
1113         *mp = m;
1114         return (0);
1115
1116   freeit:
1117         m_freem(m);
1118         *mp = NULL;
1119         return (-1);
1120 }
1121
1122 void
1123 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1124 {
1125         struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr;
1126         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1127         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1128         u_int mtu = ntohl(icmp6->icmp6_mtu);
1129         struct in_conninfo inc;
1130         uint32_t max_mtu;
1131
1132 #if 0
1133         /*
1134          * RFC2460 section 5, last paragraph.
1135          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1136          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1137          * due to packet translator in the middle.
1138          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1139          * special handling.
1140          */
1141         if (mtu < IPV6_MMTU)
1142                 return;
1143 #endif
1144
1145         /*
1146          * we reject ICMPv6 too big with abnormally small value.
1147          * XXX what is the good definition of "abnormally small"?
1148          */
1149         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1150                 return;
1151
1152         if (!validated)
1153                 return;
1154
1155         /*
1156          * In case the suggested mtu is less than IPV6_MMTU, we
1157          * only need to remember that it was for above mentioned
1158          * "alwaysfrag" case.
1159          * Try to be as close to the spec as possible.
1160          */
1161         if (mtu < IPV6_MMTU)
1162                 mtu = IPV6_MMTU - 8;
1163
1164         bzero(&inc, sizeof(inc));
1165         inc.inc_fibnum = M_GETFIB(m);
1166         inc.inc_flags |= INC_ISIPV6;
1167         inc.inc6_faddr = *dst;
1168         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1169                 return;
1170
1171         max_mtu = tcp_hc_getmtu(&inc);
1172         if (max_mtu == 0)
1173                 max_mtu = tcp_maxmtu6(&inc, NULL);
1174
1175         if (mtu < max_mtu) {
1176                 tcp_hc_updatemtu(&inc, mtu);
1177                 ICMP6STAT_INC(icp6s_pmtuchg);
1178         }
1179 }
1180
1181 /*
1182  * Process a Node Information Query packet, based on
1183  * draft-ietf-ipngwg-icmp-name-lookups-07.
1184  *
1185  * Spec incompatibilities:
1186  * - IPv6 Subject address handling
1187  * - IPv4 Subject address handling support missing
1188  * - Proxy reply (answer even if it's not for me)
1189  * - joins NI group address at in6_ifattach() time only, does not cope
1190  *   with hostname changes by sethostname(3)
1191  */
1192 static struct mbuf *
1193 ni6_input(struct mbuf *m, int off, struct prison *pr)
1194 {
1195         struct icmp6_nodeinfo *ni6, *nni6;
1196         struct mbuf *n = NULL;
1197         u_int16_t qtype;
1198         int subjlen;
1199         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1200         struct ni_reply_fqdn *fqdn;
1201         int addrs;              /* for NI_QTYPE_NODEADDR */
1202         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1203         struct in6_addr in6_subj; /* subject address */
1204         struct ip6_hdr *ip6;
1205         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1206         char *subj = NULL;
1207         struct in6_ifaddr *ia6 = NULL;
1208
1209         ip6 = mtod(m, struct ip6_hdr *);
1210         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1211
1212         /*
1213          * Validate IPv6 source address.
1214          * The default configuration MUST be to refuse answering queries from
1215          * global-scope addresses according to RFC4602.
1216          * Notes:
1217          *  - it's not very clear what "refuse" means; this implementation
1218          *    simply drops it.
1219          *  - it's not very easy to identify global-scope (unicast) addresses
1220          *    since there are many prefixes for them.  It should be safer
1221          *    and in practice sufficient to check "all" but loopback and
1222          *    link-local (note that site-local unicast was deprecated and
1223          *    ULA is defined as global scope-wise)
1224          */
1225         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1226             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1227             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1228                 goto bad;
1229
1230         /*
1231          * Validate IPv6 destination address.
1232          *
1233          * The Responder must discard the Query without further processing
1234          * unless it is one of the Responder's unicast or anycast addresses, or
1235          * a link-local scope multicast address which the Responder has joined.
1236          * [RFC4602, Section 5.]
1237          */
1238         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1239                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1240                         goto bad;
1241                 /* else it's a link-local multicast, fine */
1242         } else {                /* unicast or anycast */
1243                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
1244                 if (ia6 == NULL)
1245                         goto bad; /* XXX impossible */
1246
1247                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1248                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1249                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1250                                 "a temporary address in %s:%d",
1251                                __FILE__, __LINE__));
1252                         goto bad;
1253                 }
1254         }
1255
1256         /* validate query Subject field. */
1257         qtype = ntohs(ni6->ni_qtype);
1258         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1259         switch (qtype) {
1260         case NI_QTYPE_NOOP:
1261         case NI_QTYPE_SUPTYPES:
1262                 /* 07 draft */
1263                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1264                         break;
1265                 /* FALLTHROUGH */
1266         case NI_QTYPE_FQDN:
1267         case NI_QTYPE_NODEADDR:
1268         case NI_QTYPE_IPV4ADDR:
1269                 switch (ni6->ni_code) {
1270                 case ICMP6_NI_SUBJ_IPV6:
1271 #if ICMP6_NI_SUBJ_IPV6 != 0
1272                 case 0:
1273 #endif
1274                         /*
1275                          * backward compatibility - try to accept 03 draft
1276                          * format, where no Subject is present.
1277                          */
1278                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1279                             subjlen == 0) {
1280                                 oldfqdn++;
1281                                 break;
1282                         }
1283 #if ICMP6_NI_SUBJ_IPV6 != 0
1284                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1285                                 goto bad;
1286 #endif
1287
1288                         if (subjlen != sizeof(struct in6_addr))
1289                                 goto bad;
1290
1291                         /*
1292                          * Validate Subject address.
1293                          *
1294                          * Not sure what exactly "address belongs to the node"
1295                          * means in the spec, is it just unicast, or what?
1296                          *
1297                          * At this moment we consider Subject address as
1298                          * "belong to the node" if the Subject address equals
1299                          * to the IPv6 destination address; validation for
1300                          * IPv6 destination address should have done enough
1301                          * check for us.
1302                          *
1303                          * We do not do proxy at this moment.
1304                          */
1305                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1306                             subjlen, (caddr_t)&in6_subj);
1307                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1308                                 goto bad;
1309
1310                         subj = (char *)&in6_subj;
1311                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1312                                 break;
1313
1314                         /*
1315                          * XXX if we are to allow other cases, we should really
1316                          * be careful about scope here.
1317                          * basically, we should disallow queries toward IPv6
1318                          * destination X with subject Y,
1319                          * if scope(X) > scope(Y).
1320                          * if we allow scope(X) > scope(Y), it will result in
1321                          * information leakage across scope boundary.
1322                          */
1323                         goto bad;
1324
1325                 case ICMP6_NI_SUBJ_FQDN:
1326                         /*
1327                          * Validate Subject name with gethostname(3).
1328                          *
1329                          * The behavior may need some debate, since:
1330                          * - we are not sure if the node has FQDN as
1331                          *   hostname (returned by gethostname(3)).
1332                          * - the code does wildcard match for truncated names.
1333                          *   however, we are not sure if we want to perform
1334                          *   wildcard match, if gethostname(3) side has
1335                          *   truncated hostname.
1336                          */
1337                         mtx_lock(&pr->pr_mtx);
1338                         n = ni6_nametodns(pr->pr_hostname,
1339                             strlen(pr->pr_hostname), 0);
1340                         mtx_unlock(&pr->pr_mtx);
1341                         if (!n || n->m_next || n->m_len == 0)
1342                                 goto bad;
1343                         if (m->m_len < off + sizeof(struct icmp6_nodeinfo) +
1344                             subjlen) {
1345                                 m = m_pullup(m, off +
1346                                     sizeof(struct icmp6_nodeinfo) + subjlen);
1347                                 if (m == NULL) {
1348                                         IP6STAT_INC(ip6s_exthdrtoolong);
1349                                         goto bad;
1350                                 }
1351                         }
1352                         /* ip6 possibly invalid but not used after. */
1353                         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1354                         subj = (char *)(mtod(m, caddr_t) + off +
1355                             sizeof(struct icmp6_nodeinfo));
1356                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1357                             n->m_len)) {
1358                                 goto bad;
1359                         }
1360                         m_freem(n);
1361                         n = NULL;
1362                         break;
1363
1364                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1365                 default:
1366                         goto bad;
1367                 }
1368                 break;
1369         }
1370
1371         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1372         switch (qtype) {
1373         case NI_QTYPE_FQDN:
1374                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1375                         goto bad;
1376                 break;
1377         case NI_QTYPE_NODEADDR:
1378         case NI_QTYPE_IPV4ADDR:
1379                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1380                         goto bad;
1381                 break;
1382         }
1383
1384         /* guess reply length */
1385         switch (qtype) {
1386         case NI_QTYPE_NOOP:
1387                 break;          /* no reply data */
1388         case NI_QTYPE_SUPTYPES:
1389                 replylen += sizeof(u_int32_t);
1390                 break;
1391         case NI_QTYPE_FQDN:
1392                 /* XXX will append an mbuf */
1393                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1394                 break;
1395         case NI_QTYPE_NODEADDR:
1396                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1397                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1398                     sizeof(u_int32_t))) > MCLBYTES)
1399                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1400                 break;
1401         case NI_QTYPE_IPV4ADDR:
1402                 /* unsupported - should respond with unknown Qtype? */
1403                 break;
1404         default:
1405                 /*
1406                  * XXX: We must return a reply with the ICMP6 code
1407                  * `unknown Qtype' in this case.  However we regard the case
1408                  * as an FQDN query for backward compatibility.
1409                  * Older versions set a random value to this field,
1410                  * so it rarely varies in the defined qtypes.
1411                  * But the mechanism is not reliable...
1412                  * maybe we should obsolete older versions.
1413                  */
1414                 qtype = NI_QTYPE_FQDN;
1415                 /* XXX will append an mbuf */
1416                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1417                 oldfqdn++;
1418                 break;
1419         }
1420
1421         /* Allocate an mbuf to reply. */
1422         if (replylen > MCLBYTES) {
1423                 /*
1424                  * XXX: should we try to allocate more? But MCLBYTES
1425                  * is probably much larger than IPV6_MMTU...
1426                  */
1427                 goto bad;
1428         }
1429         if (replylen > MHLEN)
1430                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1431         else
1432                 n = m_gethdr(M_NOWAIT, m->m_type);
1433         if (n == NULL) {
1434                 m_freem(m);
1435                 return (NULL);
1436         }
1437         m_move_pkthdr(n, m); /* just for recvif and FIB */
1438         n->m_pkthdr.len = n->m_len = replylen;
1439
1440         /* copy mbuf header and IPv6 + Node Information base headers */
1441         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1442         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1443         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1444
1445         /* qtype dependent procedure */
1446         switch (qtype) {
1447         case NI_QTYPE_NOOP:
1448                 nni6->ni_code = ICMP6_NI_SUCCESS;
1449                 nni6->ni_flags = 0;
1450                 break;
1451         case NI_QTYPE_SUPTYPES:
1452         {
1453                 u_int32_t v;
1454                 nni6->ni_code = ICMP6_NI_SUCCESS;
1455                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1456                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1457                 v = (u_int32_t)htonl(0x0000000f);
1458                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1459                 break;
1460         }
1461         case NI_QTYPE_FQDN:
1462                 nni6->ni_code = ICMP6_NI_SUCCESS;
1463                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1464                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1465                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1466                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1467                 /*
1468                  * XXX do we really have FQDN in hostname?
1469                  */
1470                 mtx_lock(&pr->pr_mtx);
1471                 n->m_next = ni6_nametodns(pr->pr_hostname,
1472                     strlen(pr->pr_hostname), oldfqdn);
1473                 mtx_unlock(&pr->pr_mtx);
1474                 if (n->m_next == NULL)
1475                         goto bad;
1476                 /* XXX we assume that n->m_next is not a chain */
1477                 if (n->m_next->m_next != NULL)
1478                         goto bad;
1479                 n->m_pkthdr.len += n->m_next->m_len;
1480                 break;
1481         case NI_QTYPE_NODEADDR:
1482         {
1483                 int lenlim, copied;
1484
1485                 nni6->ni_code = ICMP6_NI_SUCCESS;
1486                 n->m_pkthdr.len = n->m_len =
1487                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1488                 lenlim = M_TRAILINGSPACE(n);
1489                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1490                 /* XXX: reset mbuf length */
1491                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1492                     sizeof(struct icmp6_nodeinfo) + copied;
1493                 break;
1494         }
1495         default:
1496                 break;          /* XXX impossible! */
1497         }
1498
1499         nni6->ni_type = ICMP6_NI_REPLY;
1500         m_freem(m);
1501         return (n);
1502
1503   bad:
1504         m_freem(m);
1505         if (n)
1506                 m_freem(n);
1507         return (NULL);
1508 }
1509
1510 /*
1511  * make a mbuf with DNS-encoded string.  no compression support.
1512  *
1513  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1514  * treated as truncated name (two \0 at the end).  this is a wild guess.
1515  *
1516  * old - return pascal string if non-zero
1517  */
1518 static struct mbuf *
1519 ni6_nametodns(const char *name, int namelen, int old)
1520 {
1521         struct mbuf *m;
1522         char *cp, *ep;
1523         const char *p, *q;
1524         int i, len, nterm;
1525
1526         if (old)
1527                 len = namelen + 1;
1528         else
1529                 len = MCLBYTES;
1530
1531         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1532         if (len > MLEN)
1533                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1534         else
1535                 m = m_get(M_NOWAIT, MT_DATA);
1536         if (m == NULL)
1537                 goto fail;
1538
1539         if (old) {
1540                 m->m_len = len;
1541                 *mtod(m, char *) = namelen;
1542                 bcopy(name, mtod(m, char *) + 1, namelen);
1543                 return m;
1544         } else {
1545                 m->m_len = 0;
1546                 cp = mtod(m, char *);
1547                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1548
1549                 /* if not certain about my name, return empty buffer */
1550                 if (namelen == 0)
1551                         return m;
1552
1553                 /*
1554                  * guess if it looks like shortened hostname, or FQDN.
1555                  * shortened hostname needs two trailing "\0".
1556                  */
1557                 i = 0;
1558                 for (p = name; p < name + namelen; p++) {
1559                         if (*p && *p == '.')
1560                                 i++;
1561                 }
1562                 if (i < 2)
1563                         nterm = 2;
1564                 else
1565                         nterm = 1;
1566
1567                 p = name;
1568                 while (cp < ep && p < name + namelen) {
1569                         i = 0;
1570                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1571                                 i++;
1572                         /* result does not fit into mbuf */
1573                         if (cp + i + 1 >= ep)
1574                                 goto fail;
1575                         /*
1576                          * DNS label length restriction, RFC1035 page 8.
1577                          * "i == 0" case is included here to avoid returning
1578                          * 0-length label on "foo..bar".
1579                          */
1580                         if (i <= 0 || i >= 64)
1581                                 goto fail;
1582                         *cp++ = i;
1583                         bcopy(p, cp, i);
1584                         cp += i;
1585                         p = q;
1586                         if (p < name + namelen && *p == '.')
1587                                 p++;
1588                 }
1589                 /* termination */
1590                 if (cp + nterm >= ep)
1591                         goto fail;
1592                 while (nterm-- > 0)
1593                         *cp++ = '\0';
1594                 m->m_len = cp - mtod(m, char *);
1595                 return m;
1596         }
1597
1598         panic("should not reach here");
1599         /* NOTREACHED */
1600
1601  fail:
1602         if (m)
1603                 m_freem(m);
1604         return NULL;
1605 }
1606
1607 /*
1608  * check if two DNS-encoded string matches.  takes care of truncated
1609  * form (with \0\0 at the end).  no compression support.
1610  * XXX upper/lowercase match (see RFC2065)
1611  */
1612 static int
1613 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1614 {
1615         const char *a0, *b0;
1616         int l;
1617
1618         /* simplest case - need validation? */
1619         if (alen == blen && bcmp(a, b, alen) == 0)
1620                 return 1;
1621
1622         a0 = a;
1623         b0 = b;
1624
1625         /* termination is mandatory */
1626         if (alen < 2 || blen < 2)
1627                 return 0;
1628         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1629                 return 0;
1630         alen--;
1631         blen--;
1632
1633         while (a - a0 < alen && b - b0 < blen) {
1634                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1635                         return 0;
1636
1637                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1638                         return 0;
1639                 /* we don't support compression yet */
1640                 if (a[0] >= 64 || b[0] >= 64)
1641                         return 0;
1642
1643                 /* truncated case */
1644                 if (a[0] == 0 && a - a0 == alen - 1)
1645                         return 1;
1646                 if (b[0] == 0 && b - b0 == blen - 1)
1647                         return 1;
1648                 if (a[0] == 0 || b[0] == 0)
1649                         return 0;
1650
1651                 if (a[0] != b[0])
1652                         return 0;
1653                 l = a[0];
1654                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1655                         return 0;
1656                 if (bcmp(a + 1, b + 1, l) != 0)
1657                         return 0;
1658
1659                 a += 1 + l;
1660                 b += 1 + l;
1661         }
1662
1663         if (a - a0 == alen && b - b0 == blen)
1664                 return 1;
1665         else
1666                 return 0;
1667 }
1668
1669 /*
1670  * calculate the number of addresses to be returned in the node info reply.
1671  */
1672 static int
1673 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1674     struct in6_addr *subj)
1675 {
1676         struct ifnet *ifp;
1677         struct in6_ifaddr *ifa6;
1678         struct ifaddr *ifa;
1679         int addrs = 0, addrsofif, iffound = 0;
1680         int niflags = ni6->ni_flags;
1681
1682         NET_EPOCH_ASSERT();
1683
1684         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1685                 switch (ni6->ni_code) {
1686                 case ICMP6_NI_SUBJ_IPV6:
1687                         if (subj == NULL) /* must be impossible... */
1688                                 return (0);
1689                         break;
1690                 default:
1691                         /*
1692                          * XXX: we only support IPv6 subject address for
1693                          * this Qtype.
1694                          */
1695                         return (0);
1696                 }
1697         }
1698
1699         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1700                 addrsofif = 0;
1701                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1702                         if (ifa->ifa_addr->sa_family != AF_INET6)
1703                                 continue;
1704                         ifa6 = (struct in6_ifaddr *)ifa;
1705
1706                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1707                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1708                                 iffound = 1;
1709
1710                         /*
1711                          * IPv4-mapped addresses can only be returned by a
1712                          * Node Information proxy, since they represent
1713                          * addresses of IPv4-only nodes, which perforce do
1714                          * not implement this protocol.
1715                          * [icmp-name-lookups-07, Section 5.4]
1716                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1717                          * this function at this moment.
1718                          */
1719
1720                         /* What do we have to do about ::1? */
1721                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1722                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1723                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1724                                         continue;
1725                                 break;
1726                         case IPV6_ADDR_SCOPE_SITELOCAL:
1727                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1728                                         continue;
1729                                 break;
1730                         case IPV6_ADDR_SCOPE_GLOBAL:
1731                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1732                                         continue;
1733                                 break;
1734                         default:
1735                                 continue;
1736                         }
1737
1738                         /*
1739                          * check if anycast is okay.
1740                          * XXX: just experimental.  not in the spec.
1741                          */
1742                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1743                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1744                                 continue; /* we need only unicast addresses */
1745                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1746                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1747                                 continue;
1748                         }
1749                         addrsofif++; /* count the address */
1750                 }
1751                 if (iffound) {
1752                         *ifpp = ifp;
1753                         return (addrsofif);
1754                 }
1755
1756                 addrs += addrsofif;
1757         }
1758
1759         return (addrs);
1760 }
1761
1762 static int
1763 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1764     struct ifnet *ifp0, int resid)
1765 {
1766         struct ifnet *ifp;
1767         struct in6_ifaddr *ifa6;
1768         struct ifaddr *ifa;
1769         struct ifnet *ifp_dep = NULL;
1770         int copied = 0, allow_deprecated = 0;
1771         u_char *cp = (u_char *)(nni6 + 1);
1772         int niflags = ni6->ni_flags;
1773         u_int32_t ltime;
1774
1775         NET_EPOCH_ASSERT();
1776
1777         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1778                 return (0);     /* needless to copy */
1779
1780         ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet);
1781   again:
1782
1783         for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) {
1784                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1785                         if (ifa->ifa_addr->sa_family != AF_INET6)
1786                                 continue;
1787                         ifa6 = (struct in6_ifaddr *)ifa;
1788
1789                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1790                             allow_deprecated == 0) {
1791                                 /*
1792                                  * prefererred address should be put before
1793                                  * deprecated addresses.
1794                                  */
1795
1796                                 /* record the interface for later search */
1797                                 if (ifp_dep == NULL)
1798                                         ifp_dep = ifp;
1799
1800                                 continue;
1801                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1802                             allow_deprecated != 0)
1803                                 continue; /* we now collect deprecated addrs */
1804
1805                         /* What do we have to do about ::1? */
1806                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1807                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1808                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1809                                         continue;
1810                                 break;
1811                         case IPV6_ADDR_SCOPE_SITELOCAL:
1812                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1813                                         continue;
1814                                 break;
1815                         case IPV6_ADDR_SCOPE_GLOBAL:
1816                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1817                                         continue;
1818                                 break;
1819                         default:
1820                                 continue;
1821                         }
1822
1823                         /*
1824                          * check if anycast is okay.
1825                          * XXX: just experimental.  not in the spec.
1826                          */
1827                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1828                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1829                                 continue;
1830                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1831                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1832                                 continue;
1833                         }
1834
1835                         /* now we can copy the address */
1836                         if (resid < sizeof(struct in6_addr) +
1837                             sizeof(u_int32_t)) {
1838                                 /*
1839                                  * We give up much more copy.
1840                                  * Set the truncate flag and return.
1841                                  */
1842                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1843                                 return (copied);
1844                         }
1845
1846                         /*
1847                          * Set the TTL of the address.
1848                          * The TTL value should be one of the following
1849                          * according to the specification:
1850                          *
1851                          * 1. The remaining lifetime of a DHCP lease on the
1852                          *    address, or
1853                          * 2. The remaining Valid Lifetime of a prefix from
1854                          *    which the address was derived through Stateless
1855                          *    Autoconfiguration.
1856                          *
1857                          * Note that we currently do not support stateful
1858                          * address configuration by DHCPv6, so the former
1859                          * case can't happen.
1860                          */
1861                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1862                                 ltime = ND6_INFINITE_LIFETIME;
1863                         else {
1864                                 if (ifa6->ia6_lifetime.ia6t_expire >
1865                                     time_uptime)
1866                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1867                                 else
1868                                         ltime = 0;
1869                         }
1870
1871                         bcopy(&ltime, cp, sizeof(u_int32_t));
1872                         cp += sizeof(u_int32_t);
1873
1874                         /* copy the address itself */
1875                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1876                             sizeof(struct in6_addr));
1877                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1878                         cp += sizeof(struct in6_addr);
1879
1880                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1881                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1882                 }
1883                 if (ifp0)       /* we need search only on the specified IF */
1884                         break;
1885         }
1886
1887         if (allow_deprecated == 0 && ifp_dep != NULL) {
1888                 ifp = ifp_dep;
1889                 allow_deprecated = 1;
1890
1891                 goto again;
1892         }
1893
1894         return (copied);
1895 }
1896
1897 static bool
1898 icmp6_rip6_match(const struct inpcb *inp, void *v)
1899 {
1900         struct ip6_hdr *ip6 = v;
1901
1902         if ((inp->inp_vflag & INP_IPV6) == 0)
1903                 return (false);
1904         if (inp->inp_ip_p != IPPROTO_ICMPV6)
1905                 return (false);
1906         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
1907            !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst))
1908                 return (false);
1909         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1910            !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src))
1911                 return (false);
1912         return (true);
1913 }
1914
1915 /*
1916  * XXX almost dup'ed code with rip6_input.
1917  */
1918 static int
1919 icmp6_rip6_input(struct mbuf **mp, int off)
1920 {
1921         struct mbuf *n, *m = *mp;
1922         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1923         struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo,
1924             INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6);
1925         struct inpcb *inp;
1926         struct sockaddr_in6 fromsa;
1927         struct icmp6_hdr *icmp6;
1928         struct mbuf *opts = NULL;
1929         int delivered = 0;
1930
1931         /* This is assumed to be safe; icmp6_input() does a pullup. */
1932         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1933
1934         /*
1935          * XXX: the address may have embedded scope zone ID, which should be
1936          * hidden from applications.
1937          */
1938         bzero(&fromsa, sizeof(fromsa));
1939         fromsa.sin6_family = AF_INET6;
1940         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1941         fromsa.sin6_addr = ip6->ip6_src;
1942         if (sa6_recoverscope(&fromsa)) {
1943                 m_freem(m);
1944                 *mp = NULL;
1945                 return (IPPROTO_DONE);
1946         }
1947
1948         while ((inp = inp_next(&inpi)) != NULL) {
1949                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1950                     inp->in6p_icmp6filt))
1951                         continue;
1952                 /*
1953                  * Recent network drivers tend to allocate a single
1954                  * mbuf cluster, rather than to make a couple of
1955                  * mbufs without clusters.  Also, since the IPv6 code
1956                  * path tries to avoid m_pullup(), it is highly
1957                  * probable that we still have an mbuf cluster here
1958                  * even though the necessary length can be stored in an
1959                  * mbuf's internal buffer.
1960                  * Meanwhile, the default size of the receive socket
1961                  * buffer for raw sockets is not so large.  This means
1962                  * the possibility of packet loss is relatively higher
1963                  * than before.  To avoid this scenario, we copy the
1964                  * received data to a separate mbuf that does not use
1965                  * a cluster, if possible.
1966                  * XXX: it is better to copy the data after stripping
1967                  * intermediate headers.
1968                  */
1969                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1970                     m->m_len <= MHLEN) {
1971                         n = m_get(M_NOWAIT, m->m_type);
1972                         if (n != NULL) {
1973                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1974                                         bcopy(m->m_data, n->m_data, m->m_len);
1975                                         n->m_len = m->m_len;
1976                                 } else {
1977                                         m_free(n);
1978                                         n = NULL;
1979                                 }
1980                         }
1981                 } else
1982                         n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
1983                 if (n == NULL)
1984                         continue;
1985                 if (inp->inp_flags & INP_CONTROLOPTS)
1986                         ip6_savecontrol(inp, n, &opts);
1987                 /* strip intermediate headers */
1988                 m_adj(n, off);
1989                 SOCKBUF_LOCK(&inp->inp_socket->so_rcv);
1990                 if (sbappendaddr_locked(&inp->inp_socket->so_rcv,
1991                     (struct sockaddr *)&fromsa, n, opts) == 0) {
1992                         soroverflow_locked(inp->inp_socket);
1993                         m_freem(n);
1994                         if (opts)
1995                                 m_freem(opts);
1996                 } else {
1997                         sorwakeup_locked(inp->inp_socket);
1998                         delivered++;
1999                 }
2000                 opts = NULL;
2001         }
2002         m_freem(m);
2003         *mp = NULL;
2004         if (delivered == 0)
2005                 IP6STAT_DEC(ip6s_delivered);
2006         return (IPPROTO_DONE);
2007 }
2008
2009 /*
2010  * Reflect the ip6 packet back to the source.
2011  * OFF points to the icmp6 header, counted from the top of the mbuf.
2012  */
2013 static void
2014 icmp6_reflect(struct mbuf *m, size_t off)
2015 {
2016         struct in6_addr src6, *srcp;
2017         struct ip6_hdr *ip6;
2018         struct icmp6_hdr *icmp6;
2019         struct in6_ifaddr *ia = NULL;
2020         struct ifnet *outif = NULL;
2021         int plen;
2022         int type, code, hlim;
2023
2024         /* too short to reflect */
2025         if (off < sizeof(struct ip6_hdr)) {
2026                 nd6log((LOG_DEBUG,
2027                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2028                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2029                     __FILE__, __LINE__));
2030                 goto bad;
2031         }
2032
2033         /*
2034          * If there are extra headers between IPv6 and ICMPv6, strip
2035          * off that header first.
2036          */
2037 #ifdef DIAGNOSTIC
2038         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2039                 panic("assumption failed in icmp6_reflect");
2040 #endif
2041         if (off > sizeof(struct ip6_hdr)) {
2042                 size_t l;
2043                 struct ip6_hdr nip6;
2044
2045                 l = off - sizeof(struct ip6_hdr);
2046                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2047                 m_adj(m, l);
2048                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2049                 if (m->m_len < l) {
2050                         if ((m = m_pullup(m, l)) == NULL)
2051                                 return;
2052                 }
2053                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2054         } else /* off == sizeof(struct ip6_hdr) */ {
2055                 size_t l;
2056                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2057                 if (m->m_len < l) {
2058                         if ((m = m_pullup(m, l)) == NULL)
2059                                 return;
2060                 }
2061         }
2062         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2063         ip6 = mtod(m, struct ip6_hdr *);
2064         ip6->ip6_nxt = IPPROTO_ICMPV6;
2065         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2066         type = icmp6->icmp6_type; /* keep type for statistics */
2067         code = icmp6->icmp6_code; /* ditto. */
2068         hlim = 0;
2069         srcp = NULL;
2070
2071         /*
2072          * If the incoming packet was addressed directly to us (i.e. unicast),
2073          * use dst as the src for the reply.
2074          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2075          * (for example) when we encounter an error while forwarding procedure
2076          * destined to a duplicated address of ours.
2077          */
2078         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2079                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
2080                 if (ia != NULL && !(ia->ia6_flags &
2081                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2082                         src6 = ia->ia_addr.sin6_addr;
2083                         srcp = &src6;
2084
2085                         if (m->m_pkthdr.rcvif != NULL) {
2086                                 /* XXX: This may not be the outgoing interface */
2087                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2088                         } else
2089                                 hlim = V_ip6_defhlim;
2090                 }
2091         }
2092
2093         if (srcp == NULL) {
2094                 int error;
2095                 struct in6_addr dst6;
2096                 uint32_t scopeid;
2097
2098                 /*
2099                  * This case matches to multicasts, our anycast, or unicasts
2100                  * that we do not own.  Select a source address based on the
2101                  * source address of the erroneous packet.
2102                  */
2103                 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2104                 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2105                     scopeid, NULL, &src6, &hlim);
2106
2107                 if (error) {
2108                         char ip6buf[INET6_ADDRSTRLEN];
2109                         nd6log((LOG_DEBUG,
2110                             "icmp6_reflect: source can't be determined: "
2111                             "dst=%s, error=%d\n",
2112                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2113                         goto bad;
2114                 }
2115                 srcp = &src6;
2116         }
2117         /*
2118          * ip6_input() drops a packet if its src is multicast.
2119          * So, the src is never multicast.
2120          */
2121         ip6->ip6_dst = ip6->ip6_src;
2122         ip6->ip6_src = *srcp;
2123         ip6->ip6_flow = 0;
2124         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2125         ip6->ip6_vfc |= IPV6_VERSION;
2126         ip6->ip6_nxt = IPPROTO_ICMPV6;
2127         ip6->ip6_hlim = hlim;
2128
2129         icmp6->icmp6_cksum = 0;
2130         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2131             sizeof(struct ip6_hdr), plen);
2132
2133         /*
2134          * XXX option handling
2135          */
2136
2137         m->m_flags &= ~(M_BCAST|M_MCAST);
2138         m->m_pkthdr.rcvif = NULL;
2139         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2140         if (outif)
2141                 icmp6_ifoutstat_inc(outif, type, code);
2142
2143         return;
2144
2145  bad:
2146         m_freem(m);
2147         return;
2148 }
2149
2150 static const char *
2151 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2152     struct in6_addr *tgt6)
2153 {
2154         static char buf[1024];
2155         char ip6bufs[INET6_ADDRSTRLEN];
2156         char ip6bufd[INET6_ADDRSTRLEN];
2157         char ip6buft[INET6_ADDRSTRLEN];
2158         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2159             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2160             ip6_sprintf(ip6buft, tgt6));
2161         return buf;
2162 }
2163
2164 void
2165 icmp6_redirect_input(struct mbuf *m, int off)
2166 {
2167         struct ifnet *ifp;
2168         struct ip6_hdr *ip6;
2169         struct nd_redirect *nd_rd;
2170         struct in6_addr src6, redtgt6, reddst6;
2171         union nd_opts ndopts;
2172         char ip6buf[INET6_ADDRSTRLEN];
2173         char *lladdr;
2174         int icmp6len, is_onlink, is_router, lladdrlen;
2175
2176         M_ASSERTPKTHDR(m);
2177         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2178
2179         /* XXX if we are router, we don't update route by icmp6 redirect */
2180         if (V_ip6_forwarding)
2181                 goto freeit;
2182         if (!V_icmp6_rediraccept)
2183                 goto freeit;
2184
2185         /* RFC 6980: Nodes MUST silently ignore fragments */
2186         if(m->m_flags & M_FRAGMENTED)
2187                 goto freeit;
2188
2189         ip6 = mtod(m, struct ip6_hdr *);
2190         icmp6len = ntohs(ip6->ip6_plen);
2191         if (m->m_len < off + icmp6len) {
2192                 m = m_pullup(m, off + icmp6len);
2193                 if (m == NULL) {
2194                         IP6STAT_INC(ip6s_exthdrtoolong);
2195                         return;
2196                 }
2197         }
2198         ip6 = mtod(m, struct ip6_hdr *);
2199         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2200
2201         ifp = m->m_pkthdr.rcvif;
2202         redtgt6 = nd_rd->nd_rd_target;
2203         reddst6 = nd_rd->nd_rd_dst;
2204
2205         if (in6_setscope(&redtgt6, ifp, NULL) ||
2206             in6_setscope(&reddst6, ifp, NULL)) {
2207                 goto freeit;
2208         }
2209
2210         /* validation */
2211         src6 = ip6->ip6_src;
2212         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2213                 nd6log((LOG_ERR,
2214                     "ICMP6 redirect sent from %s rejected; "
2215                     "must be from linklocal\n",
2216                     ip6_sprintf(ip6buf, &src6)));
2217                 goto bad;
2218         }
2219         if (__predict_false(ip6->ip6_hlim != 255)) {
2220                 ICMP6STAT_INC(icp6s_invlhlim);
2221                 nd6log((LOG_ERR,
2222                     "ICMP6 redirect sent from %s rejected; "
2223                     "hlim=%d (must be 255)\n",
2224                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2225                 goto bad;
2226         }
2227     {
2228         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2229         struct nhop_object *nh;
2230         struct in6_addr kdst;
2231         uint32_t scopeid;
2232
2233         in6_splitscope(&reddst6, &kdst, &scopeid);
2234         NET_EPOCH_ASSERT();
2235         nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0);
2236         if (nh != NULL) {
2237                 struct in6_addr nh_addr;
2238                 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr;
2239                 if ((nh->nh_flags & NHF_GATEWAY) == 0) {
2240                         nd6log((LOG_ERR,
2241                             "ICMP6 redirect rejected; no route "
2242                             "with inet6 gateway found for redirect dst: %s\n",
2243                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2244                         goto bad;
2245                 }
2246
2247                 /*
2248                  * Embed scope zone id into next hop address.
2249                  */
2250                 nh_addr = nh->gw6_sa.sin6_addr;
2251
2252                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) {
2253                         nd6log((LOG_ERR,
2254                             "ICMP6 redirect rejected; "
2255                             "not equal to gw-for-src=%s (must be same): "
2256                             "%s\n",
2257                             ip6_sprintf(ip6buf, &nh_addr),
2258                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2259                         goto bad;
2260                 }
2261         } else {
2262                 nd6log((LOG_ERR,
2263                     "ICMP6 redirect rejected; "
2264                     "no route found for redirect dst: %s\n",
2265                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2266                 goto bad;
2267         }
2268     }
2269         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2270                 nd6log((LOG_ERR,
2271                     "ICMP6 redirect rejected; "
2272                     "redirect dst must be unicast: %s\n",
2273                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2274                 goto bad;
2275         }
2276
2277         is_router = is_onlink = 0;
2278         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2279                 is_router = 1;  /* router case */
2280         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2281                 is_onlink = 1;  /* on-link destination case */
2282         if (!is_router && !is_onlink) {
2283                 nd6log((LOG_ERR,
2284                     "ICMP6 redirect rejected; "
2285                     "neither router case nor onlink case: %s\n",
2286                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2287                 goto bad;
2288         }
2289
2290         icmp6len -= sizeof(*nd_rd);
2291         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2292         if (nd6_options(&ndopts) < 0) {
2293                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2294                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2295                 /* nd6_options have incremented stats */
2296                 goto freeit;
2297         }
2298
2299         lladdr = NULL;
2300         lladdrlen = 0;
2301         if (ndopts.nd_opts_tgt_lladdr) {
2302                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2303                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2304         }
2305
2306         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2307                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2308                     "(if %d, icmp6 packet %d): %s\n",
2309                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2310                     ifp->if_addrlen, lladdrlen - 2,
2311                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2312                 goto bad;
2313         }
2314
2315         /* Validation passed. */
2316
2317         /* RFC 2461 8.3 */
2318         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2319             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2320
2321         /*
2322          * Install a gateway route in the better-router case or an interface
2323          * route in the on-link-destination case.
2324          */
2325         {
2326                 struct sockaddr_in6 sdst;
2327                 struct sockaddr_in6 sgw;
2328                 struct sockaddr_in6 ssrc;
2329                 struct sockaddr *gw;
2330                 int rt_flags;
2331                 u_int fibnum;
2332
2333                 bzero(&sdst, sizeof(sdst));
2334                 bzero(&ssrc, sizeof(ssrc));
2335                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2336                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2337                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2338                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2339                 rt_flags = 0;
2340                 if (is_router) {
2341                         bzero(&sgw, sizeof(sgw));
2342                         sgw.sin6_family = AF_INET6;
2343                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2344                         bcopy(&redtgt6, &sgw.sin6_addr,
2345                                 sizeof(struct in6_addr));
2346                         gw = (struct sockaddr *)&sgw;
2347                         rt_flags |= RTF_GATEWAY;
2348                 } else
2349                         gw = ifp->if_addr->ifa_addr;
2350                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2351                         rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw,
2352                             (struct sockaddr *)&ssrc, ifp, rt_flags,
2353                             V_icmp6_redirtimeout);
2354         }
2355
2356  freeit:
2357         m_freem(m);
2358         return;
2359
2360  bad:
2361         ICMP6STAT_INC(icp6s_badredirect);
2362         m_freem(m);
2363 }
2364
2365 void
2366 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh)
2367 {
2368         struct ifnet *ifp;      /* my outgoing interface */
2369         struct in6_addr *ifp_ll6;
2370         struct in6_addr *router_ll6;
2371         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2372         struct mbuf *m = NULL;  /* newly allocated one */
2373         struct m_tag *mtag;
2374         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2375         struct nd_redirect *nd_rd;
2376         struct llentry *ln = NULL;
2377         size_t maxlen;
2378         u_char *p;
2379         struct ifnet *outif = NULL;
2380         struct sockaddr_in6 src_sa;
2381
2382         icmp6_errcount(ND_REDIRECT, 0);
2383
2384         /* if we are not router, we don't send icmp6 redirect */
2385         if (!V_ip6_forwarding)
2386                 goto fail;
2387
2388         /* sanity check */
2389         if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp))
2390                 goto fail;
2391
2392         /*
2393          * Address check:
2394          *  the source address must identify a neighbor, and
2395          *  the destination address must not be a multicast address
2396          *  [RFC 2461, sec 8.2]
2397          */
2398         sip6 = mtod(m0, struct ip6_hdr *);
2399         bzero(&src_sa, sizeof(src_sa));
2400         src_sa.sin6_family = AF_INET6;
2401         src_sa.sin6_len = sizeof(src_sa);
2402         src_sa.sin6_addr = sip6->ip6_src;
2403         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2404                 goto fail;
2405         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2406                 goto fail;      /* what should we do here? */
2407
2408         /* rate limit */
2409         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2410                 goto fail;
2411
2412         /*
2413          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2414          * we almost always ask for an mbuf cluster for simplicity.
2415          * (MHLEN < IPV6_MMTU is almost always true)
2416          */
2417 #if IPV6_MMTU >= MCLBYTES
2418 # error assumption failed about IPV6_MMTU and MCLBYTES
2419 #endif
2420         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2421         if (m == NULL)
2422                 goto fail;
2423         M_SETFIB(m, M_GETFIB(m0));
2424         maxlen = M_TRAILINGSPACE(m);
2425         maxlen = min(IPV6_MMTU, maxlen);
2426         /* just for safety */
2427         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2428             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2429                 goto fail;
2430         }
2431
2432         {
2433                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2434                 struct in6_ifaddr *ia;
2435                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2436                                                  IN6_IFF_NOTREADY|
2437                                                  IN6_IFF_ANYCAST)) == NULL)
2438                         goto fail;
2439                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2440                 /* XXXRW: reference released prematurely. */
2441                 ifa_free(&ia->ia_ifa);
2442         }
2443
2444         /* get ip6 linklocal address for the router. */
2445         if (nh->nh_flags & NHF_GATEWAY) {
2446                 struct sockaddr_in6 *sin6;
2447                 sin6 = &nh->gw6_sa;
2448                 router_ll6 = &sin6->sin6_addr;
2449                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2450                         router_ll6 = (struct in6_addr *)NULL;
2451         } else
2452                 router_ll6 = (struct in6_addr *)NULL;
2453
2454         /* ip6 */
2455         ip6 = mtod(m, struct ip6_hdr *);
2456         ip6->ip6_flow = 0;
2457         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2458         ip6->ip6_vfc |= IPV6_VERSION;
2459         /* ip6->ip6_plen will be set later */
2460         ip6->ip6_nxt = IPPROTO_ICMPV6;
2461         ip6->ip6_hlim = 255;
2462         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2463         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2464         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2465
2466         /* ND Redirect */
2467         nd_rd = (struct nd_redirect *)(ip6 + 1);
2468         nd_rd->nd_rd_type = ND_REDIRECT;
2469         nd_rd->nd_rd_code = 0;
2470         nd_rd->nd_rd_reserved = 0;
2471         if (nh->nh_flags & NHF_GATEWAY) {
2472                 /*
2473                  * nd_rd->nd_rd_target must be a link-local address in
2474                  * better router cases.
2475                  */
2476                 if (!router_ll6)
2477                         goto fail;
2478                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2479                     sizeof(nd_rd->nd_rd_target));
2480                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2481                     sizeof(nd_rd->nd_rd_dst));
2482         } else {
2483                 /* make sure redtgt == reddst */
2484                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2485                     sizeof(nd_rd->nd_rd_target));
2486                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2487                     sizeof(nd_rd->nd_rd_dst));
2488         }
2489
2490         p = (u_char *)(nd_rd + 1);
2491
2492         if (!router_ll6)
2493                 goto nolladdropt;
2494
2495         {
2496                 /* target lladdr option */
2497                 int len;
2498                 struct nd_opt_hdr *nd_opt;
2499                 char *lladdr;
2500
2501                 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6,  0), ifp);
2502                 if (ln == NULL)
2503                         goto nolladdropt;
2504
2505                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2506                 len = (len + 7) & ~7;   /* round by 8 */
2507                 /* safety check */
2508                 if (len + (p - (u_char *)ip6) > maxlen)
2509                         goto nolladdropt;
2510
2511                 if (ln->la_flags & LLE_VALID) {
2512                         nd_opt = (struct nd_opt_hdr *)p;
2513                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2514                         nd_opt->nd_opt_len = len >> 3;
2515                         lladdr = (char *)(nd_opt + 1);
2516                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2517                         p += len;
2518                 }
2519         }
2520 nolladdropt:
2521         if (ln != NULL)
2522                 LLE_RUNLOCK(ln);
2523
2524         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2525
2526         /* just to be safe */
2527 #ifdef M_DECRYPTED      /*not openbsd*/
2528         if (m0->m_flags & M_DECRYPTED)
2529                 goto noredhdropt;
2530 #endif
2531         if (p - (u_char *)ip6 > maxlen)
2532                 goto noredhdropt;
2533
2534         {
2535                 /* redirected header option */
2536                 int len;
2537                 struct nd_opt_rd_hdr *nd_opt_rh;
2538
2539                 /*
2540                  * compute the maximum size for icmp6 redirect header option.
2541                  * XXX room for auth header?
2542                  */
2543                 len = maxlen - (p - (u_char *)ip6);
2544                 len &= ~7;
2545
2546                 /* This is just for simplicity. */
2547                 if (m0->m_pkthdr.len != m0->m_len) {
2548                         if (m0->m_next) {
2549                                 m_freem(m0->m_next);
2550                                 m0->m_next = NULL;
2551                         }
2552                         m0->m_pkthdr.len = m0->m_len;
2553                 }
2554
2555                 /*
2556                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2557                  * about padding/truncate rule for the original IP packet.
2558                  * From the discussion on IPv6imp in Feb 1999,
2559                  * the consensus was:
2560                  * - "attach as much as possible" is the goal
2561                  * - pad if not aligned (original size can be guessed by
2562                  *   original ip6 header)
2563                  * Following code adds the padding if it is simple enough,
2564                  * and truncates if not.
2565                  */
2566                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2567                         panic("assumption failed in %s:%d", __FILE__,
2568                             __LINE__);
2569
2570                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2571                         /* not enough room, truncate */
2572                         m0->m_pkthdr.len = m0->m_len = len -
2573                             sizeof(*nd_opt_rh);
2574                 } else {
2575                         /* enough room, pad or truncate */
2576                         size_t extra;
2577
2578                         extra = m0->m_pkthdr.len % 8;
2579                         if (extra) {
2580                                 /* pad if easy enough, truncate if not */
2581                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2582                                         /* pad */
2583                                         m0->m_len += (8 - extra);
2584                                         m0->m_pkthdr.len += (8 - extra);
2585                                 } else {
2586                                         /* truncate */
2587                                         m0->m_pkthdr.len -= extra;
2588                                         m0->m_len -= extra;
2589                                 }
2590                         }
2591                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2592                         m0->m_pkthdr.len = m0->m_len = len -
2593                             sizeof(*nd_opt_rh);
2594                 }
2595
2596                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2597                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2598                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2599                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2600                 p += sizeof(*nd_opt_rh);
2601                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2602
2603                 /* connect m0 to m */
2604                 m_tag_delete_chain(m0, NULL);
2605                 m0->m_flags &= ~M_PKTHDR;
2606                 m->m_next = m0;
2607                 m->m_pkthdr.len = m->m_len + m0->m_len;
2608                 m0 = NULL;
2609         }
2610 noredhdropt:;
2611         if (m0) {
2612                 m_freem(m0);
2613                 m0 = NULL;
2614         }
2615
2616         /* XXX: clear embedded link IDs in the inner header */
2617         in6_clearscope(&sip6->ip6_src);
2618         in6_clearscope(&sip6->ip6_dst);
2619         in6_clearscope(&nd_rd->nd_rd_target);
2620         in6_clearscope(&nd_rd->nd_rd_dst);
2621
2622         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2623
2624         nd_rd->nd_rd_cksum = 0;
2625         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2626             sizeof(*ip6), ntohs(ip6->ip6_plen));
2627
2628         if (send_sendso_input_hook != NULL) {
2629                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2630                         M_NOWAIT);
2631                 if (mtag == NULL)
2632                         goto fail;
2633                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2634                 m_tag_prepend(m, mtag);
2635         }
2636
2637         /* send the packet to outside... */
2638         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2639         if (outif) {
2640                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2641                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2642         }
2643         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2644
2645         return;
2646
2647 fail:
2648         if (m)
2649                 m_freem(m);
2650         if (m0)
2651                 m_freem(m0);
2652 }
2653
2654 /*
2655  * ICMPv6 socket option processing.
2656  */
2657 int
2658 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2659 {
2660         int error = 0;
2661         int optlen;
2662         struct inpcb *inp = sotoinpcb(so);
2663         int level, op, optname;
2664
2665         if (sopt) {
2666                 level = sopt->sopt_level;
2667                 op = sopt->sopt_dir;
2668                 optname = sopt->sopt_name;
2669                 optlen = sopt->sopt_valsize;
2670         } else
2671                 level = op = optname = optlen = 0;
2672
2673         if (level != IPPROTO_ICMPV6) {
2674                 return EINVAL;
2675         }
2676
2677         switch (op) {
2678         case PRCO_SETOPT:
2679                 switch (optname) {
2680                 case ICMP6_FILTER:
2681                     {
2682                         struct icmp6_filter ic6f;
2683
2684                         if (optlen != sizeof(ic6f)) {
2685                                 error = EMSGSIZE;
2686                                 break;
2687                         }
2688                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2689                         if (error == 0) {
2690                                 INP_WLOCK(inp);
2691                                 *inp->in6p_icmp6filt = ic6f;
2692                                 INP_WUNLOCK(inp);
2693                         }
2694                         break;
2695                     }
2696
2697                 default:
2698                         error = ENOPROTOOPT;
2699                         break;
2700                 }
2701                 break;
2702
2703         case PRCO_GETOPT:
2704                 switch (optname) {
2705                 case ICMP6_FILTER:
2706                     {
2707                         struct icmp6_filter ic6f;
2708
2709                         INP_RLOCK(inp);
2710                         ic6f = *inp->in6p_icmp6filt;
2711                         INP_RUNLOCK(inp);
2712                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2713                         break;
2714                     }
2715
2716                 default:
2717                         error = ENOPROTOOPT;
2718                         break;
2719                 }
2720                 break;
2721         }
2722
2723         return (error);
2724 }
2725
2726 /*
2727  * Perform rate limit check.
2728  * Returns 0 if it is okay to send the icmp6 packet.
2729  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2730  * limitation.
2731  *
2732  * XXX per-destination/type check necessary?
2733  *
2734  * dst - not used at this moment
2735  * type - not used at this moment
2736  * code - not used at this moment
2737  */
2738 int
2739 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2740     const int code)
2741 {
2742         int ret;
2743
2744         ret = 0;        /* okay to send */
2745
2746         /* PPS limit */
2747         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2748             V_icmp6errppslim)) {
2749                 /* The packet is subject to rate limit */
2750                 ret++;
2751         }
2752
2753         return ret;
2754 }