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                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1074                 icmp6dst.sin6_family = AF_INET6;
1075                 if (IN6_IS_ADDR_UNSPECIFIED(&icmp6dst.sin6_addr))
1076                         icmp6dst.sin6_addr = eip6->ip6_dst;
1077                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1078                         goto freeit;
1079                 bzero(&icmp6src, sizeof(icmp6src));
1080                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1081                 icmp6src.sin6_family = AF_INET6;
1082                 icmp6src.sin6_addr = eip6->ip6_src;
1083                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1084                         goto freeit;
1085                 icmp6src.sin6_flowinfo =
1086                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1087
1088                 ip6cp.ip6c_m = m;
1089                 ip6cp.ip6c_icmp6 = icmp6;
1090                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1091                 ip6cp.ip6c_off = eoff;
1092                 ip6cp.ip6c_finaldst = &icmp6dst;
1093                 ip6cp.ip6c_src = &icmp6src;
1094                 ip6cp.ip6c_nxt = nxt;
1095
1096                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1097                         notifymtu = ntohl(icmp6->icmp6_mtu);
1098                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1099                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1100                 }
1101
1102                 if (ip6_ctlprotox[nxt] != NULL)
1103                         ip6_ctlprotox[nxt](&ip6cp);
1104         }
1105         *mp = m;
1106         return (0);
1107
1108   freeit:
1109         m_freem(m);
1110         *mp = NULL;
1111         return (-1);
1112 }
1113
1114 void
1115 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1116 {
1117         struct in6_addr *dst = &ip6cp->ip6c_finaldst->sin6_addr;
1118         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1119         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1120         u_int mtu = ntohl(icmp6->icmp6_mtu);
1121         struct in_conninfo inc;
1122         uint32_t max_mtu;
1123
1124 #if 0
1125         /*
1126          * RFC2460 section 5, last paragraph.
1127          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1128          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1129          * due to packet translator in the middle.
1130          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1131          * special handling.
1132          */
1133         if (mtu < IPV6_MMTU)
1134                 return;
1135 #endif
1136
1137         /*
1138          * we reject ICMPv6 too big with abnormally small value.
1139          * XXX what is the good definition of "abnormally small"?
1140          */
1141         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1142                 return;
1143
1144         if (!validated)
1145                 return;
1146
1147         /*
1148          * In case the suggested mtu is less than IPV6_MMTU, we
1149          * only need to remember that it was for above mentioned
1150          * "alwaysfrag" case.
1151          * Try to be as close to the spec as possible.
1152          */
1153         if (mtu < IPV6_MMTU)
1154                 mtu = IPV6_MMTU - 8;
1155
1156         bzero(&inc, sizeof(inc));
1157         inc.inc_fibnum = M_GETFIB(m);
1158         inc.inc_flags |= INC_ISIPV6;
1159         inc.inc6_faddr = *dst;
1160         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1161                 return;
1162
1163         max_mtu = tcp_hc_getmtu(&inc);
1164         if (max_mtu == 0)
1165                 max_mtu = tcp_maxmtu6(&inc, NULL);
1166
1167         if (mtu < max_mtu) {
1168                 tcp_hc_updatemtu(&inc, mtu);
1169                 ICMP6STAT_INC(icp6s_pmtuchg);
1170         }
1171 }
1172
1173 /*
1174  * Process a Node Information Query packet, based on
1175  * draft-ietf-ipngwg-icmp-name-lookups-07.
1176  *
1177  * Spec incompatibilities:
1178  * - IPv6 Subject address handling
1179  * - IPv4 Subject address handling support missing
1180  * - Proxy reply (answer even if it's not for me)
1181  * - joins NI group address at in6_ifattach() time only, does not cope
1182  *   with hostname changes by sethostname(3)
1183  */
1184 static struct mbuf *
1185 ni6_input(struct mbuf *m, int off, struct prison *pr)
1186 {
1187         struct icmp6_nodeinfo *ni6, *nni6;
1188         struct mbuf *n = NULL;
1189         u_int16_t qtype;
1190         int subjlen;
1191         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1192         struct ni_reply_fqdn *fqdn;
1193         int addrs;              /* for NI_QTYPE_NODEADDR */
1194         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1195         struct in6_addr in6_subj; /* subject address */
1196         struct ip6_hdr *ip6;
1197         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1198         char *subj = NULL;
1199         struct in6_ifaddr *ia6 = NULL;
1200
1201         ip6 = mtod(m, struct ip6_hdr *);
1202         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1203
1204         /*
1205          * Validate IPv6 source address.
1206          * The default configuration MUST be to refuse answering queries from
1207          * global-scope addresses according to RFC4602.
1208          * Notes:
1209          *  - it's not very clear what "refuse" means; this implementation
1210          *    simply drops it.
1211          *  - it's not very easy to identify global-scope (unicast) addresses
1212          *    since there are many prefixes for them.  It should be safer
1213          *    and in practice sufficient to check "all" but loopback and
1214          *    link-local (note that site-local unicast was deprecated and
1215          *    ULA is defined as global scope-wise)
1216          */
1217         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1218             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1219             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1220                 goto bad;
1221
1222         /*
1223          * Validate IPv6 destination address.
1224          *
1225          * The Responder must discard the Query without further processing
1226          * unless it is one of the Responder's unicast or anycast addresses, or
1227          * a link-local scope multicast address which the Responder has joined.
1228          * [RFC4602, Section 5.]
1229          */
1230         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1231                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1232                         goto bad;
1233                 /* else it's a link-local multicast, fine */
1234         } else {                /* unicast or anycast */
1235                 ia6 = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
1236                 if (ia6 == NULL)
1237                         goto bad; /* XXX impossible */
1238
1239                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1240                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1241                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1242                                 "a temporary address in %s:%d",
1243                                __FILE__, __LINE__));
1244                         goto bad;
1245                 }
1246         }
1247
1248         /* validate query Subject field. */
1249         qtype = ntohs(ni6->ni_qtype);
1250         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1251         switch (qtype) {
1252         case NI_QTYPE_NOOP:
1253         case NI_QTYPE_SUPTYPES:
1254                 /* 07 draft */
1255                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1256                         break;
1257                 /* FALLTHROUGH */
1258         case NI_QTYPE_FQDN:
1259         case NI_QTYPE_NODEADDR:
1260         case NI_QTYPE_IPV4ADDR:
1261                 switch (ni6->ni_code) {
1262                 case ICMP6_NI_SUBJ_IPV6:
1263 #if ICMP6_NI_SUBJ_IPV6 != 0
1264                 case 0:
1265 #endif
1266                         /*
1267                          * backward compatibility - try to accept 03 draft
1268                          * format, where no Subject is present.
1269                          */
1270                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1271                             subjlen == 0) {
1272                                 oldfqdn++;
1273                                 break;
1274                         }
1275 #if ICMP6_NI_SUBJ_IPV6 != 0
1276                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1277                                 goto bad;
1278 #endif
1279
1280                         if (subjlen != sizeof(struct in6_addr))
1281                                 goto bad;
1282
1283                         /*
1284                          * Validate Subject address.
1285                          *
1286                          * Not sure what exactly "address belongs to the node"
1287                          * means in the spec, is it just unicast, or what?
1288                          *
1289                          * At this moment we consider Subject address as
1290                          * "belong to the node" if the Subject address equals
1291                          * to the IPv6 destination address; validation for
1292                          * IPv6 destination address should have done enough
1293                          * check for us.
1294                          *
1295                          * We do not do proxy at this moment.
1296                          */
1297                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1298                             subjlen, (caddr_t)&in6_subj);
1299                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1300                                 goto bad;
1301
1302                         subj = (char *)&in6_subj;
1303                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1304                                 break;
1305
1306                         /*
1307                          * XXX if we are to allow other cases, we should really
1308                          * be careful about scope here.
1309                          * basically, we should disallow queries toward IPv6
1310                          * destination X with subject Y,
1311                          * if scope(X) > scope(Y).
1312                          * if we allow scope(X) > scope(Y), it will result in
1313                          * information leakage across scope boundary.
1314                          */
1315                         goto bad;
1316
1317                 case ICMP6_NI_SUBJ_FQDN:
1318                         /*
1319                          * Validate Subject name with gethostname(3).
1320                          *
1321                          * The behavior may need some debate, since:
1322                          * - we are not sure if the node has FQDN as
1323                          *   hostname (returned by gethostname(3)).
1324                          * - the code does wildcard match for truncated names.
1325                          *   however, we are not sure if we want to perform
1326                          *   wildcard match, if gethostname(3) side has
1327                          *   truncated hostname.
1328                          */
1329                         mtx_lock(&pr->pr_mtx);
1330                         n = ni6_nametodns(pr->pr_hostname,
1331                             strlen(pr->pr_hostname), 0);
1332                         mtx_unlock(&pr->pr_mtx);
1333                         if (!n || n->m_next || n->m_len == 0)
1334                                 goto bad;
1335                         if (m->m_len < off + sizeof(struct icmp6_nodeinfo) +
1336                             subjlen) {
1337                                 m = m_pullup(m, off +
1338                                     sizeof(struct icmp6_nodeinfo) + subjlen);
1339                                 if (m == NULL) {
1340                                         IP6STAT_INC(ip6s_exthdrtoolong);
1341                                         goto bad;
1342                                 }
1343                         }
1344                         /* ip6 possibly invalid but not used after. */
1345                         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1346                         subj = (char *)(mtod(m, caddr_t) + off +
1347                             sizeof(struct icmp6_nodeinfo));
1348                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1349                             n->m_len)) {
1350                                 goto bad;
1351                         }
1352                         m_freem(n);
1353                         n = NULL;
1354                         break;
1355
1356                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1357                 default:
1358                         goto bad;
1359                 }
1360                 break;
1361         }
1362
1363         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1364         switch (qtype) {
1365         case NI_QTYPE_FQDN:
1366                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1367                         goto bad;
1368                 break;
1369         case NI_QTYPE_NODEADDR:
1370         case NI_QTYPE_IPV4ADDR:
1371                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1372                         goto bad;
1373                 break;
1374         }
1375
1376         /* guess reply length */
1377         switch (qtype) {
1378         case NI_QTYPE_NOOP:
1379                 break;          /* no reply data */
1380         case NI_QTYPE_SUPTYPES:
1381                 replylen += sizeof(u_int32_t);
1382                 break;
1383         case NI_QTYPE_FQDN:
1384                 /* XXX will append an mbuf */
1385                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1386                 break;
1387         case NI_QTYPE_NODEADDR:
1388                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1389                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1390                     sizeof(u_int32_t))) > MCLBYTES)
1391                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1392                 break;
1393         case NI_QTYPE_IPV4ADDR:
1394                 /* unsupported - should respond with unknown Qtype? */
1395                 break;
1396         default:
1397                 /*
1398                  * XXX: We must return a reply with the ICMP6 code
1399                  * `unknown Qtype' in this case.  However we regard the case
1400                  * as an FQDN query for backward compatibility.
1401                  * Older versions set a random value to this field,
1402                  * so it rarely varies in the defined qtypes.
1403                  * But the mechanism is not reliable...
1404                  * maybe we should obsolete older versions.
1405                  */
1406                 qtype = NI_QTYPE_FQDN;
1407                 /* XXX will append an mbuf */
1408                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1409                 oldfqdn++;
1410                 break;
1411         }
1412
1413         /* Allocate an mbuf to reply. */
1414         if (replylen > MCLBYTES) {
1415                 /*
1416                  * XXX: should we try to allocate more? But MCLBYTES
1417                  * is probably much larger than IPV6_MMTU...
1418                  */
1419                 goto bad;
1420         }
1421         if (replylen > MHLEN)
1422                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1423         else
1424                 n = m_gethdr(M_NOWAIT, m->m_type);
1425         if (n == NULL) {
1426                 m_freem(m);
1427                 return (NULL);
1428         }
1429         m_move_pkthdr(n, m); /* just for recvif and FIB */
1430         n->m_pkthdr.len = n->m_len = replylen;
1431
1432         /* copy mbuf header and IPv6 + Node Information base headers */
1433         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1434         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1435         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1436
1437         /* qtype dependent procedure */
1438         switch (qtype) {
1439         case NI_QTYPE_NOOP:
1440                 nni6->ni_code = ICMP6_NI_SUCCESS;
1441                 nni6->ni_flags = 0;
1442                 break;
1443         case NI_QTYPE_SUPTYPES:
1444         {
1445                 u_int32_t v;
1446                 nni6->ni_code = ICMP6_NI_SUCCESS;
1447                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1448                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1449                 v = (u_int32_t)htonl(0x0000000f);
1450                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1451                 break;
1452         }
1453         case NI_QTYPE_FQDN:
1454                 nni6->ni_code = ICMP6_NI_SUCCESS;
1455                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1456                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1457                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1458                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1459                 /*
1460                  * XXX do we really have FQDN in hostname?
1461                  */
1462                 mtx_lock(&pr->pr_mtx);
1463                 n->m_next = ni6_nametodns(pr->pr_hostname,
1464                     strlen(pr->pr_hostname), oldfqdn);
1465                 mtx_unlock(&pr->pr_mtx);
1466                 if (n->m_next == NULL)
1467                         goto bad;
1468                 /* XXX we assume that n->m_next is not a chain */
1469                 if (n->m_next->m_next != NULL)
1470                         goto bad;
1471                 n->m_pkthdr.len += n->m_next->m_len;
1472                 break;
1473         case NI_QTYPE_NODEADDR:
1474         {
1475                 int lenlim, copied;
1476
1477                 nni6->ni_code = ICMP6_NI_SUCCESS;
1478                 n->m_pkthdr.len = n->m_len =
1479                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1480                 lenlim = M_TRAILINGSPACE(n);
1481                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1482                 /* XXX: reset mbuf length */
1483                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1484                     sizeof(struct icmp6_nodeinfo) + copied;
1485                 break;
1486         }
1487         default:
1488                 break;          /* XXX impossible! */
1489         }
1490
1491         nni6->ni_type = ICMP6_NI_REPLY;
1492         m_freem(m);
1493         return (n);
1494
1495   bad:
1496         m_freem(m);
1497         if (n)
1498                 m_freem(n);
1499         return (NULL);
1500 }
1501
1502 /*
1503  * make a mbuf with DNS-encoded string.  no compression support.
1504  *
1505  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1506  * treated as truncated name (two \0 at the end).  this is a wild guess.
1507  *
1508  * old - return pascal string if non-zero
1509  */
1510 static struct mbuf *
1511 ni6_nametodns(const char *name, int namelen, int old)
1512 {
1513         struct mbuf *m;
1514         char *cp, *ep;
1515         const char *p, *q;
1516         int i, len, nterm;
1517
1518         if (old)
1519                 len = namelen + 1;
1520         else
1521                 len = MCLBYTES;
1522
1523         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1524         if (len > MLEN)
1525                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1526         else
1527                 m = m_get(M_NOWAIT, MT_DATA);
1528         if (m == NULL)
1529                 goto fail;
1530
1531         if (old) {
1532                 m->m_len = len;
1533                 *mtod(m, char *) = namelen;
1534                 bcopy(name, mtod(m, char *) + 1, namelen);
1535                 return m;
1536         } else {
1537                 m->m_len = 0;
1538                 cp = mtod(m, char *);
1539                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1540
1541                 /* if not certain about my name, return empty buffer */
1542                 if (namelen == 0)
1543                         return m;
1544
1545                 /*
1546                  * guess if it looks like shortened hostname, or FQDN.
1547                  * shortened hostname needs two trailing "\0".
1548                  */
1549                 i = 0;
1550                 for (p = name; p < name + namelen; p++) {
1551                         if (*p && *p == '.')
1552                                 i++;
1553                 }
1554                 if (i < 2)
1555                         nterm = 2;
1556                 else
1557                         nterm = 1;
1558
1559                 p = name;
1560                 while (cp < ep && p < name + namelen) {
1561                         i = 0;
1562                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1563                                 i++;
1564                         /* result does not fit into mbuf */
1565                         if (cp + i + 1 >= ep)
1566                                 goto fail;
1567                         /*
1568                          * DNS label length restriction, RFC1035 page 8.
1569                          * "i == 0" case is included here to avoid returning
1570                          * 0-length label on "foo..bar".
1571                          */
1572                         if (i <= 0 || i >= 64)
1573                                 goto fail;
1574                         *cp++ = i;
1575                         bcopy(p, cp, i);
1576                         cp += i;
1577                         p = q;
1578                         if (p < name + namelen && *p == '.')
1579                                 p++;
1580                 }
1581                 /* termination */
1582                 if (cp + nterm >= ep)
1583                         goto fail;
1584                 while (nterm-- > 0)
1585                         *cp++ = '\0';
1586                 m->m_len = cp - mtod(m, char *);
1587                 return m;
1588         }
1589
1590         panic("should not reach here");
1591         /* NOTREACHED */
1592
1593  fail:
1594         if (m)
1595                 m_freem(m);
1596         return NULL;
1597 }
1598
1599 /*
1600  * check if two DNS-encoded string matches.  takes care of truncated
1601  * form (with \0\0 at the end).  no compression support.
1602  * XXX upper/lowercase match (see RFC2065)
1603  */
1604 static int
1605 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1606 {
1607         const char *a0, *b0;
1608         int l;
1609
1610         /* simplest case - need validation? */
1611         if (alen == blen && bcmp(a, b, alen) == 0)
1612                 return 1;
1613
1614         a0 = a;
1615         b0 = b;
1616
1617         /* termination is mandatory */
1618         if (alen < 2 || blen < 2)
1619                 return 0;
1620         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1621                 return 0;
1622         alen--;
1623         blen--;
1624
1625         while (a - a0 < alen && b - b0 < blen) {
1626                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1627                         return 0;
1628
1629                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1630                         return 0;
1631                 /* we don't support compression yet */
1632                 if (a[0] >= 64 || b[0] >= 64)
1633                         return 0;
1634
1635                 /* truncated case */
1636                 if (a[0] == 0 && a - a0 == alen - 1)
1637                         return 1;
1638                 if (b[0] == 0 && b - b0 == blen - 1)
1639                         return 1;
1640                 if (a[0] == 0 || b[0] == 0)
1641                         return 0;
1642
1643                 if (a[0] != b[0])
1644                         return 0;
1645                 l = a[0];
1646                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1647                         return 0;
1648                 if (bcmp(a + 1, b + 1, l) != 0)
1649                         return 0;
1650
1651                 a += 1 + l;
1652                 b += 1 + l;
1653         }
1654
1655         if (a - a0 == alen && b - b0 == blen)
1656                 return 1;
1657         else
1658                 return 0;
1659 }
1660
1661 /*
1662  * calculate the number of addresses to be returned in the node info reply.
1663  */
1664 static int
1665 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1666     struct in6_addr *subj)
1667 {
1668         struct ifnet *ifp;
1669         struct in6_ifaddr *ifa6;
1670         struct ifaddr *ifa;
1671         int addrs = 0, addrsofif, iffound = 0;
1672         int niflags = ni6->ni_flags;
1673
1674         NET_EPOCH_ASSERT();
1675
1676         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1677                 switch (ni6->ni_code) {
1678                 case ICMP6_NI_SUBJ_IPV6:
1679                         if (subj == NULL) /* must be impossible... */
1680                                 return (0);
1681                         break;
1682                 default:
1683                         /*
1684                          * XXX: we only support IPv6 subject address for
1685                          * this Qtype.
1686                          */
1687                         return (0);
1688                 }
1689         }
1690
1691         CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
1692                 addrsofif = 0;
1693                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1694                         if (ifa->ifa_addr->sa_family != AF_INET6)
1695                                 continue;
1696                         ifa6 = (struct in6_ifaddr *)ifa;
1697
1698                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1699                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1700                                 iffound = 1;
1701
1702                         /*
1703                          * IPv4-mapped addresses can only be returned by a
1704                          * Node Information proxy, since they represent
1705                          * addresses of IPv4-only nodes, which perforce do
1706                          * not implement this protocol.
1707                          * [icmp-name-lookups-07, Section 5.4]
1708                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1709                          * this function at this moment.
1710                          */
1711
1712                         /* What do we have to do about ::1? */
1713                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1714                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1715                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1716                                         continue;
1717                                 break;
1718                         case IPV6_ADDR_SCOPE_SITELOCAL:
1719                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1720                                         continue;
1721                                 break;
1722                         case IPV6_ADDR_SCOPE_GLOBAL:
1723                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1724                                         continue;
1725                                 break;
1726                         default:
1727                                 continue;
1728                         }
1729
1730                         /*
1731                          * check if anycast is okay.
1732                          * XXX: just experimental.  not in the spec.
1733                          */
1734                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1735                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1736                                 continue; /* we need only unicast addresses */
1737                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1738                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1739                                 continue;
1740                         }
1741                         addrsofif++; /* count the address */
1742                 }
1743                 if (iffound) {
1744                         *ifpp = ifp;
1745                         return (addrsofif);
1746                 }
1747
1748                 addrs += addrsofif;
1749         }
1750
1751         return (addrs);
1752 }
1753
1754 static int
1755 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1756     struct ifnet *ifp0, int resid)
1757 {
1758         struct ifnet *ifp;
1759         struct in6_ifaddr *ifa6;
1760         struct ifaddr *ifa;
1761         struct ifnet *ifp_dep = NULL;
1762         int copied = 0, allow_deprecated = 0;
1763         u_char *cp = (u_char *)(nni6 + 1);
1764         int niflags = ni6->ni_flags;
1765         u_int32_t ltime;
1766
1767         NET_EPOCH_ASSERT();
1768
1769         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1770                 return (0);     /* needless to copy */
1771
1772         ifp = ifp0 ? ifp0 : CK_STAILQ_FIRST(&V_ifnet);
1773   again:
1774
1775         for (; ifp; ifp = CK_STAILQ_NEXT(ifp, if_link)) {
1776                 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1777                         if (ifa->ifa_addr->sa_family != AF_INET6)
1778                                 continue;
1779                         ifa6 = (struct in6_ifaddr *)ifa;
1780
1781                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1782                             allow_deprecated == 0) {
1783                                 /*
1784                                  * prefererred address should be put before
1785                                  * deprecated addresses.
1786                                  */
1787
1788                                 /* record the interface for later search */
1789                                 if (ifp_dep == NULL)
1790                                         ifp_dep = ifp;
1791
1792                                 continue;
1793                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1794                             allow_deprecated != 0)
1795                                 continue; /* we now collect deprecated addrs */
1796
1797                         /* What do we have to do about ::1? */
1798                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1799                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1800                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1801                                         continue;
1802                                 break;
1803                         case IPV6_ADDR_SCOPE_SITELOCAL:
1804                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1805                                         continue;
1806                                 break;
1807                         case IPV6_ADDR_SCOPE_GLOBAL:
1808                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1809                                         continue;
1810                                 break;
1811                         default:
1812                                 continue;
1813                         }
1814
1815                         /*
1816                          * check if anycast is okay.
1817                          * XXX: just experimental.  not in the spec.
1818                          */
1819                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1820                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1821                                 continue;
1822                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1823                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1824                                 continue;
1825                         }
1826
1827                         /* now we can copy the address */
1828                         if (resid < sizeof(struct in6_addr) +
1829                             sizeof(u_int32_t)) {
1830                                 /*
1831                                  * We give up much more copy.
1832                                  * Set the truncate flag and return.
1833                                  */
1834                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1835                                 return (copied);
1836                         }
1837
1838                         /*
1839                          * Set the TTL of the address.
1840                          * The TTL value should be one of the following
1841                          * according to the specification:
1842                          *
1843                          * 1. The remaining lifetime of a DHCP lease on the
1844                          *    address, or
1845                          * 2. The remaining Valid Lifetime of a prefix from
1846                          *    which the address was derived through Stateless
1847                          *    Autoconfiguration.
1848                          *
1849                          * Note that we currently do not support stateful
1850                          * address configuration by DHCPv6, so the former
1851                          * case can't happen.
1852                          */
1853                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1854                                 ltime = ND6_INFINITE_LIFETIME;
1855                         else {
1856                                 if (ifa6->ia6_lifetime.ia6t_expire >
1857                                     time_uptime)
1858                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1859                                 else
1860                                         ltime = 0;
1861                         }
1862
1863                         bcopy(&ltime, cp, sizeof(u_int32_t));
1864                         cp += sizeof(u_int32_t);
1865
1866                         /* copy the address itself */
1867                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1868                             sizeof(struct in6_addr));
1869                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1870                         cp += sizeof(struct in6_addr);
1871
1872                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1873                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1874                 }
1875                 if (ifp0)       /* we need search only on the specified IF */
1876                         break;
1877         }
1878
1879         if (allow_deprecated == 0 && ifp_dep != NULL) {
1880                 ifp = ifp_dep;
1881                 allow_deprecated = 1;
1882
1883                 goto again;
1884         }
1885
1886         return (copied);
1887 }
1888
1889 static bool
1890 icmp6_rip6_match(const struct inpcb *inp, void *v)
1891 {
1892         struct ip6_hdr *ip6 = v;
1893
1894         if ((inp->inp_vflag & INP_IPV6) == 0)
1895                 return (false);
1896         if (inp->inp_ip_p != IPPROTO_ICMPV6)
1897                 return (false);
1898         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
1899            !IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, &ip6->ip6_dst))
1900                 return (false);
1901         if (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr) &&
1902            !IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, &ip6->ip6_src))
1903                 return (false);
1904         return (true);
1905 }
1906
1907 /*
1908  * XXX almost dup'ed code with rip6_input.
1909  */
1910 static int
1911 icmp6_rip6_input(struct mbuf **mp, int off)
1912 {
1913         struct mbuf *n, *m = *mp;
1914         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1915         struct inpcb_iterator inpi = INP_ITERATOR(&V_ripcbinfo,
1916             INPLOOKUP_RLOCKPCB, icmp6_rip6_match, ip6);
1917         struct inpcb *inp;
1918         struct sockaddr_in6 fromsa;
1919         struct icmp6_hdr *icmp6;
1920         struct mbuf *opts = NULL;
1921         int delivered = 0;
1922
1923         /* This is assumed to be safe; icmp6_input() does a pullup. */
1924         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1925
1926         /*
1927          * XXX: the address may have embedded scope zone ID, which should be
1928          * hidden from applications.
1929          */
1930         bzero(&fromsa, sizeof(fromsa));
1931         fromsa.sin6_family = AF_INET6;
1932         fromsa.sin6_len = sizeof(struct sockaddr_in6);
1933         fromsa.sin6_addr = ip6->ip6_src;
1934         if (sa6_recoverscope(&fromsa)) {
1935                 m_freem(m);
1936                 *mp = NULL;
1937                 return (IPPROTO_DONE);
1938         }
1939
1940         while ((inp = inp_next(&inpi)) != NULL) {
1941                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1942                     inp->in6p_icmp6filt))
1943                         continue;
1944                 /*
1945                  * Recent network drivers tend to allocate a single
1946                  * mbuf cluster, rather than to make a couple of
1947                  * mbufs without clusters.  Also, since the IPv6 code
1948                  * path tries to avoid m_pullup(), it is highly
1949                  * probable that we still have an mbuf cluster here
1950                  * even though the necessary length can be stored in an
1951                  * mbuf's internal buffer.
1952                  * Meanwhile, the default size of the receive socket
1953                  * buffer for raw sockets is not so large.  This means
1954                  * the possibility of packet loss is relatively higher
1955                  * than before.  To avoid this scenario, we copy the
1956                  * received data to a separate mbuf that does not use
1957                  * a cluster, if possible.
1958                  * XXX: it is better to copy the data after stripping
1959                  * intermediate headers.
1960                  */
1961                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
1962                     m->m_len <= MHLEN) {
1963                         n = m_get(M_NOWAIT, m->m_type);
1964                         if (n != NULL) {
1965                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
1966                                         bcopy(m->m_data, n->m_data, m->m_len);
1967                                         n->m_len = m->m_len;
1968                                 } else {
1969                                         m_free(n);
1970                                         n = NULL;
1971                                 }
1972                         }
1973                 } else
1974                         n = m_copym(m, 0, M_COPYALL, M_NOWAIT);
1975                 if (n == NULL)
1976                         continue;
1977                 if (inp->inp_flags & INP_CONTROLOPTS)
1978                         ip6_savecontrol(inp, n, &opts);
1979                 /* strip intermediate headers */
1980                 m_adj(n, off);
1981                 SOCKBUF_LOCK(&inp->inp_socket->so_rcv);
1982                 if (sbappendaddr_locked(&inp->inp_socket->so_rcv,
1983                     (struct sockaddr *)&fromsa, n, opts) == 0) {
1984                         soroverflow_locked(inp->inp_socket);
1985                         m_freem(n);
1986                         if (opts)
1987                                 m_freem(opts);
1988                 } else {
1989                         sorwakeup_locked(inp->inp_socket);
1990                         delivered++;
1991                 }
1992                 opts = NULL;
1993         }
1994         m_freem(m);
1995         *mp = NULL;
1996         if (delivered == 0)
1997                 IP6STAT_DEC(ip6s_delivered);
1998         return (IPPROTO_DONE);
1999 }
2000
2001 /*
2002  * Reflect the ip6 packet back to the source.
2003  * OFF points to the icmp6 header, counted from the top of the mbuf.
2004  */
2005 static void
2006 icmp6_reflect(struct mbuf *m, size_t off)
2007 {
2008         struct in6_addr src6, *srcp;
2009         struct ip6_hdr *ip6;
2010         struct icmp6_hdr *icmp6;
2011         struct in6_ifaddr *ia = NULL;
2012         struct ifnet *outif = NULL;
2013         int plen;
2014         int type, code, hlim;
2015
2016         /* too short to reflect */
2017         if (off < sizeof(struct ip6_hdr)) {
2018                 nd6log((LOG_DEBUG,
2019                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2020                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2021                     __FILE__, __LINE__));
2022                 goto bad;
2023         }
2024
2025         /*
2026          * If there are extra headers between IPv6 and ICMPv6, strip
2027          * off that header first.
2028          */
2029 #ifdef DIAGNOSTIC
2030         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2031                 panic("assumption failed in icmp6_reflect");
2032 #endif
2033         if (off > sizeof(struct ip6_hdr)) {
2034                 size_t l;
2035                 struct ip6_hdr nip6;
2036
2037                 l = off - sizeof(struct ip6_hdr);
2038                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2039                 m_adj(m, l);
2040                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2041                 if (m->m_len < l) {
2042                         if ((m = m_pullup(m, l)) == NULL)
2043                                 return;
2044                 }
2045                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2046         } else /* off == sizeof(struct ip6_hdr) */ {
2047                 size_t 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         }
2054         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2055         ip6 = mtod(m, struct ip6_hdr *);
2056         ip6->ip6_nxt = IPPROTO_ICMPV6;
2057         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2058         type = icmp6->icmp6_type; /* keep type for statistics */
2059         code = icmp6->icmp6_code; /* ditto. */
2060         hlim = 0;
2061         srcp = NULL;
2062
2063         /*
2064          * If the incoming packet was addressed directly to us (i.e. unicast),
2065          * use dst as the src for the reply.
2066          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2067          * (for example) when we encounter an error while forwarding procedure
2068          * destined to a duplicated address of ours.
2069          */
2070         if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
2071                 ia = in6ifa_ifwithaddr(&ip6->ip6_dst, 0 /* XXX */, false);
2072                 if (ia != NULL && !(ia->ia6_flags &
2073                     (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2074                         src6 = ia->ia_addr.sin6_addr;
2075                         srcp = &src6;
2076
2077                         if (m->m_pkthdr.rcvif != NULL) {
2078                                 /* XXX: This may not be the outgoing interface */
2079                                 hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2080                         } else
2081                                 hlim = V_ip6_defhlim;
2082                 }
2083         }
2084
2085         if (srcp == NULL) {
2086                 int error;
2087                 struct in6_addr dst6;
2088                 uint32_t scopeid;
2089
2090                 /*
2091                  * This case matches to multicasts, our anycast, or unicasts
2092                  * that we do not own.  Select a source address based on the
2093                  * source address of the erroneous packet.
2094                  */
2095                 in6_splitscope(&ip6->ip6_src, &dst6, &scopeid);
2096                 error = in6_selectsrc_addr(M_GETFIB(m), &dst6,
2097                     scopeid, NULL, &src6, &hlim);
2098
2099                 if (error) {
2100                         char ip6buf[INET6_ADDRSTRLEN];
2101                         nd6log((LOG_DEBUG,
2102                             "icmp6_reflect: source can't be determined: "
2103                             "dst=%s, error=%d\n",
2104                             ip6_sprintf(ip6buf, &ip6->ip6_dst), error));
2105                         goto bad;
2106                 }
2107                 srcp = &src6;
2108         }
2109         /*
2110          * ip6_input() drops a packet if its src is multicast.
2111          * So, the src is never multicast.
2112          */
2113         ip6->ip6_dst = ip6->ip6_src;
2114         ip6->ip6_src = *srcp;
2115         ip6->ip6_flow = 0;
2116         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2117         ip6->ip6_vfc |= IPV6_VERSION;
2118         ip6->ip6_nxt = IPPROTO_ICMPV6;
2119         ip6->ip6_hlim = hlim;
2120
2121         icmp6->icmp6_cksum = 0;
2122         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2123             sizeof(struct ip6_hdr), plen);
2124
2125         /*
2126          * XXX option handling
2127          */
2128
2129         m->m_flags &= ~(M_BCAST|M_MCAST);
2130         m->m_pkthdr.rcvif = NULL;
2131         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2132         if (outif)
2133                 icmp6_ifoutstat_inc(outif, type, code);
2134
2135         return;
2136
2137  bad:
2138         m_freem(m);
2139         return;
2140 }
2141
2142 static const char *
2143 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2144     struct in6_addr *tgt6)
2145 {
2146         static char buf[1024];
2147         char ip6bufs[INET6_ADDRSTRLEN];
2148         char ip6bufd[INET6_ADDRSTRLEN];
2149         char ip6buft[INET6_ADDRSTRLEN];
2150         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2151             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2152             ip6_sprintf(ip6buft, tgt6));
2153         return buf;
2154 }
2155
2156 void
2157 icmp6_redirect_input(struct mbuf *m, int off)
2158 {
2159         struct ifnet *ifp;
2160         struct ip6_hdr *ip6;
2161         struct nd_redirect *nd_rd;
2162         struct in6_addr src6, redtgt6, reddst6;
2163         union nd_opts ndopts;
2164         char ip6buf[INET6_ADDRSTRLEN];
2165         char *lladdr;
2166         int icmp6len, is_onlink, is_router, lladdrlen;
2167
2168         M_ASSERTPKTHDR(m);
2169         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2170
2171         /* XXX if we are router, we don't update route by icmp6 redirect */
2172         if (V_ip6_forwarding)
2173                 goto freeit;
2174         if (!V_icmp6_rediraccept)
2175                 goto freeit;
2176
2177         /* RFC 6980: Nodes MUST silently ignore fragments */
2178         if(m->m_flags & M_FRAGMENTED)
2179                 goto freeit;
2180
2181         ip6 = mtod(m, struct ip6_hdr *);
2182         icmp6len = ntohs(ip6->ip6_plen);
2183         if (m->m_len < off + icmp6len) {
2184                 m = m_pullup(m, off + icmp6len);
2185                 if (m == NULL) {
2186                         IP6STAT_INC(ip6s_exthdrtoolong);
2187                         return;
2188                 }
2189         }
2190         ip6 = mtod(m, struct ip6_hdr *);
2191         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2192
2193         ifp = m->m_pkthdr.rcvif;
2194         redtgt6 = nd_rd->nd_rd_target;
2195         reddst6 = nd_rd->nd_rd_dst;
2196
2197         if (in6_setscope(&redtgt6, ifp, NULL) ||
2198             in6_setscope(&reddst6, ifp, NULL)) {
2199                 goto freeit;
2200         }
2201
2202         /* validation */
2203         src6 = ip6->ip6_src;
2204         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2205                 nd6log((LOG_ERR,
2206                     "ICMP6 redirect sent from %s rejected; "
2207                     "must be from linklocal\n",
2208                     ip6_sprintf(ip6buf, &src6)));
2209                 goto bad;
2210         }
2211         if (__predict_false(ip6->ip6_hlim != 255)) {
2212                 ICMP6STAT_INC(icp6s_invlhlim);
2213                 nd6log((LOG_ERR,
2214                     "ICMP6 redirect sent from %s rejected; "
2215                     "hlim=%d (must be 255)\n",
2216                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2217                 goto bad;
2218         }
2219     {
2220         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2221         struct nhop_object *nh;
2222         struct in6_addr kdst;
2223         uint32_t scopeid;
2224
2225         in6_splitscope(&reddst6, &kdst, &scopeid);
2226         NET_EPOCH_ASSERT();
2227         nh = fib6_lookup(ifp->if_fib, &kdst, scopeid, 0, 0);
2228         if (nh != NULL) {
2229                 struct in6_addr nh_addr;
2230                 nh_addr = ifatoia6(nh->nh_ifa)->ia_addr.sin6_addr;
2231                 if ((nh->nh_flags & NHF_GATEWAY) == 0) {
2232                         nd6log((LOG_ERR,
2233                             "ICMP6 redirect rejected; no route "
2234                             "with inet6 gateway found for redirect dst: %s\n",
2235                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2236                         goto bad;
2237                 }
2238
2239                 /*
2240                  * Embed scope zone id into next hop address.
2241                  */
2242                 nh_addr = nh->gw6_sa.sin6_addr;
2243
2244                 if (IN6_ARE_ADDR_EQUAL(&src6, &nh_addr) == 0) {
2245                         nd6log((LOG_ERR,
2246                             "ICMP6 redirect rejected; "
2247                             "not equal to gw-for-src=%s (must be same): "
2248                             "%s\n",
2249                             ip6_sprintf(ip6buf, &nh_addr),
2250                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2251                         goto bad;
2252                 }
2253         } else {
2254                 nd6log((LOG_ERR,
2255                     "ICMP6 redirect rejected; "
2256                     "no route found for redirect dst: %s\n",
2257                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2258                 goto bad;
2259         }
2260     }
2261         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2262                 nd6log((LOG_ERR,
2263                     "ICMP6 redirect rejected; "
2264                     "redirect dst must be unicast: %s\n",
2265                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2266                 goto bad;
2267         }
2268
2269         is_router = is_onlink = 0;
2270         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2271                 is_router = 1;  /* router case */
2272         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2273                 is_onlink = 1;  /* on-link destination case */
2274         if (!is_router && !is_onlink) {
2275                 nd6log((LOG_ERR,
2276                     "ICMP6 redirect rejected; "
2277                     "neither router case nor onlink case: %s\n",
2278                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2279                 goto bad;
2280         }
2281
2282         icmp6len -= sizeof(*nd_rd);
2283         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2284         if (nd6_options(&ndopts) < 0) {
2285                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2286                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2287                 /* nd6_options have incremented stats */
2288                 goto freeit;
2289         }
2290
2291         lladdr = NULL;
2292         lladdrlen = 0;
2293         if (ndopts.nd_opts_tgt_lladdr) {
2294                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2295                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2296         }
2297
2298         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2299                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2300                     "(if %d, icmp6 packet %d): %s\n",
2301                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2302                     ifp->if_addrlen, lladdrlen - 2,
2303                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2304                 goto bad;
2305         }
2306
2307         /* Validation passed. */
2308
2309         /* RFC 2461 8.3 */
2310         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2311             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2312
2313         /*
2314          * Install a gateway route in the better-router case or an interface
2315          * route in the on-link-destination case.
2316          */
2317         {
2318                 struct sockaddr_in6 sdst;
2319                 struct sockaddr_in6 sgw;
2320                 struct sockaddr_in6 ssrc;
2321                 struct sockaddr *gw;
2322                 int rt_flags;
2323                 u_int fibnum;
2324
2325                 bzero(&sdst, sizeof(sdst));
2326                 bzero(&ssrc, sizeof(ssrc));
2327                 sdst.sin6_family = ssrc.sin6_family = AF_INET6;
2328                 sdst.sin6_len = ssrc.sin6_len = sizeof(struct sockaddr_in6);
2329                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2330                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2331                 rt_flags = 0;
2332                 if (is_router) {
2333                         bzero(&sgw, sizeof(sgw));
2334                         sgw.sin6_family = AF_INET6;
2335                         sgw.sin6_len = sizeof(struct sockaddr_in6);
2336                         bcopy(&redtgt6, &sgw.sin6_addr,
2337                                 sizeof(struct in6_addr));
2338                         gw = (struct sockaddr *)&sgw;
2339                         rt_flags |= RTF_GATEWAY;
2340                 } else
2341                         gw = ifp->if_addr->ifa_addr;
2342                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2343                         rib_add_redirect(fibnum, (struct sockaddr *)&sdst, gw,
2344                             (struct sockaddr *)&ssrc, ifp, rt_flags,
2345                             V_icmp6_redirtimeout);
2346         }
2347
2348  freeit:
2349         m_freem(m);
2350         return;
2351
2352  bad:
2353         ICMP6STAT_INC(icp6s_badredirect);
2354         m_freem(m);
2355 }
2356
2357 void
2358 icmp6_redirect_output(struct mbuf *m0, struct nhop_object *nh)
2359 {
2360         struct ifnet *ifp;      /* my outgoing interface */
2361         struct in6_addr *ifp_ll6;
2362         struct in6_addr *router_ll6;
2363         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2364         struct mbuf *m = NULL;  /* newly allocated one */
2365         struct m_tag *mtag;
2366         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2367         struct nd_redirect *nd_rd;
2368         struct llentry *ln = NULL;
2369         size_t maxlen;
2370         u_char *p;
2371         struct ifnet *outif = NULL;
2372         struct sockaddr_in6 src_sa;
2373
2374         icmp6_errcount(ND_REDIRECT, 0);
2375
2376         /* if we are not router, we don't send icmp6 redirect */
2377         if (!V_ip6_forwarding)
2378                 goto fail;
2379
2380         /* sanity check */
2381         if (!m0 || !nh || !(NH_IS_VALID(nh)) || !(ifp = nh->nh_ifp))
2382                 goto fail;
2383
2384         /*
2385          * Address check:
2386          *  the source address must identify a neighbor, and
2387          *  the destination address must not be a multicast address
2388          *  [RFC 2461, sec 8.2]
2389          */
2390         sip6 = mtod(m0, struct ip6_hdr *);
2391         bzero(&src_sa, sizeof(src_sa));
2392         src_sa.sin6_family = AF_INET6;
2393         src_sa.sin6_len = sizeof(src_sa);
2394         src_sa.sin6_addr = sip6->ip6_src;
2395         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2396                 goto fail;
2397         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2398                 goto fail;      /* what should we do here? */
2399
2400         /* rate limit */
2401         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2402                 goto fail;
2403
2404         /*
2405          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2406          * we almost always ask for an mbuf cluster for simplicity.
2407          * (MHLEN < IPV6_MMTU is almost always true)
2408          */
2409 #if IPV6_MMTU >= MCLBYTES
2410 # error assumption failed about IPV6_MMTU and MCLBYTES
2411 #endif
2412         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2413         if (m == NULL)
2414                 goto fail;
2415         M_SETFIB(m, M_GETFIB(m0));
2416         maxlen = M_TRAILINGSPACE(m);
2417         maxlen = min(IPV6_MMTU, maxlen);
2418         /* just for safety */
2419         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2420             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2421                 goto fail;
2422         }
2423
2424         {
2425                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2426                 struct in6_ifaddr *ia;
2427                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2428                                                  IN6_IFF_NOTREADY|
2429                                                  IN6_IFF_ANYCAST)) == NULL)
2430                         goto fail;
2431                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2432                 /* XXXRW: reference released prematurely. */
2433                 ifa_free(&ia->ia_ifa);
2434         }
2435
2436         /* get ip6 linklocal address for the router. */
2437         if (nh->nh_flags & NHF_GATEWAY) {
2438                 struct sockaddr_in6 *sin6;
2439                 sin6 = &nh->gw6_sa;
2440                 router_ll6 = &sin6->sin6_addr;
2441                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2442                         router_ll6 = (struct in6_addr *)NULL;
2443         } else
2444                 router_ll6 = (struct in6_addr *)NULL;
2445
2446         /* ip6 */
2447         ip6 = mtod(m, struct ip6_hdr *);
2448         ip6->ip6_flow = 0;
2449         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2450         ip6->ip6_vfc |= IPV6_VERSION;
2451         /* ip6->ip6_plen will be set later */
2452         ip6->ip6_nxt = IPPROTO_ICMPV6;
2453         ip6->ip6_hlim = 255;
2454         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2455         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2456         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2457
2458         /* ND Redirect */
2459         nd_rd = (struct nd_redirect *)(ip6 + 1);
2460         nd_rd->nd_rd_type = ND_REDIRECT;
2461         nd_rd->nd_rd_code = 0;
2462         nd_rd->nd_rd_reserved = 0;
2463         if (nh->nh_flags & NHF_GATEWAY) {
2464                 /*
2465                  * nd_rd->nd_rd_target must be a link-local address in
2466                  * better router cases.
2467                  */
2468                 if (!router_ll6)
2469                         goto fail;
2470                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2471                     sizeof(nd_rd->nd_rd_target));
2472                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2473                     sizeof(nd_rd->nd_rd_dst));
2474         } else {
2475                 /* make sure redtgt == reddst */
2476                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2477                     sizeof(nd_rd->nd_rd_target));
2478                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2479                     sizeof(nd_rd->nd_rd_dst));
2480         }
2481
2482         p = (u_char *)(nd_rd + 1);
2483
2484         if (!router_ll6)
2485                 goto nolladdropt;
2486
2487         {
2488                 /* target lladdr option */
2489                 int len;
2490                 struct nd_opt_hdr *nd_opt;
2491                 char *lladdr;
2492
2493                 ln = nd6_lookup(router_ll6, LLE_SF(AF_INET6,  0), ifp);
2494                 if (ln == NULL)
2495                         goto nolladdropt;
2496
2497                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2498                 len = (len + 7) & ~7;   /* round by 8 */
2499                 /* safety check */
2500                 if (len + (p - (u_char *)ip6) > maxlen)
2501                         goto nolladdropt;
2502
2503                 if (ln->la_flags & LLE_VALID) {
2504                         nd_opt = (struct nd_opt_hdr *)p;
2505                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2506                         nd_opt->nd_opt_len = len >> 3;
2507                         lladdr = (char *)(nd_opt + 1);
2508                         bcopy(ln->ll_addr, lladdr, ifp->if_addrlen);
2509                         p += len;
2510                 }
2511         }
2512 nolladdropt:
2513         if (ln != NULL)
2514                 LLE_RUNLOCK(ln);
2515
2516         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2517
2518         /* just to be safe */
2519 #ifdef M_DECRYPTED      /*not openbsd*/
2520         if (m0->m_flags & M_DECRYPTED)
2521                 goto noredhdropt;
2522 #endif
2523         if (p - (u_char *)ip6 > maxlen)
2524                 goto noredhdropt;
2525
2526         {
2527                 /* redirected header option */
2528                 int len;
2529                 struct nd_opt_rd_hdr *nd_opt_rh;
2530
2531                 /*
2532                  * compute the maximum size for icmp6 redirect header option.
2533                  * XXX room for auth header?
2534                  */
2535                 len = maxlen - (p - (u_char *)ip6);
2536                 len &= ~7;
2537
2538                 /* This is just for simplicity. */
2539                 if (m0->m_pkthdr.len != m0->m_len) {
2540                         if (m0->m_next) {
2541                                 m_freem(m0->m_next);
2542                                 m0->m_next = NULL;
2543                         }
2544                         m0->m_pkthdr.len = m0->m_len;
2545                 }
2546
2547                 /*
2548                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2549                  * about padding/truncate rule for the original IP packet.
2550                  * From the discussion on IPv6imp in Feb 1999,
2551                  * the consensus was:
2552                  * - "attach as much as possible" is the goal
2553                  * - pad if not aligned (original size can be guessed by
2554                  *   original ip6 header)
2555                  * Following code adds the padding if it is simple enough,
2556                  * and truncates if not.
2557                  */
2558                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2559                         panic("assumption failed in %s:%d", __FILE__,
2560                             __LINE__);
2561
2562                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2563                         /* not enough room, truncate */
2564                         m0->m_pkthdr.len = m0->m_len = len -
2565                             sizeof(*nd_opt_rh);
2566                 } else {
2567                         /* enough room, pad or truncate */
2568                         size_t extra;
2569
2570                         extra = m0->m_pkthdr.len % 8;
2571                         if (extra) {
2572                                 /* pad if easy enough, truncate if not */
2573                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2574                                         /* pad */
2575                                         m0->m_len += (8 - extra);
2576                                         m0->m_pkthdr.len += (8 - extra);
2577                                 } else {
2578                                         /* truncate */
2579                                         m0->m_pkthdr.len -= extra;
2580                                         m0->m_len -= extra;
2581                                 }
2582                         }
2583                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2584                         m0->m_pkthdr.len = m0->m_len = len -
2585                             sizeof(*nd_opt_rh);
2586                 }
2587
2588                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2589                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2590                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2591                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2592                 p += sizeof(*nd_opt_rh);
2593                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2594
2595                 /* connect m0 to m */
2596                 m_tag_delete_chain(m0, NULL);
2597                 m0->m_flags &= ~M_PKTHDR;
2598                 m->m_next = m0;
2599                 m->m_pkthdr.len = m->m_len + m0->m_len;
2600                 m0 = NULL;
2601         }
2602 noredhdropt:;
2603         if (m0) {
2604                 m_freem(m0);
2605                 m0 = NULL;
2606         }
2607
2608         /* XXX: clear embedded link IDs in the inner header */
2609         in6_clearscope(&sip6->ip6_src);
2610         in6_clearscope(&sip6->ip6_dst);
2611         in6_clearscope(&nd_rd->nd_rd_target);
2612         in6_clearscope(&nd_rd->nd_rd_dst);
2613
2614         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2615
2616         nd_rd->nd_rd_cksum = 0;
2617         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2618             sizeof(*ip6), ntohs(ip6->ip6_plen));
2619
2620         if (send_sendso_input_hook != NULL) {
2621                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2622                         M_NOWAIT);
2623                 if (mtag == NULL)
2624                         goto fail;
2625                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2626                 m_tag_prepend(m, mtag);
2627         }
2628
2629         /* send the packet to outside... */
2630         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2631         if (outif) {
2632                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2633                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2634         }
2635         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2636
2637         return;
2638
2639 fail:
2640         if (m)
2641                 m_freem(m);
2642         if (m0)
2643                 m_freem(m0);
2644 }
2645
2646 /*
2647  * ICMPv6 socket option processing.
2648  */
2649 int
2650 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2651 {
2652         int error = 0;
2653         int optlen;
2654         struct inpcb *inp = sotoinpcb(so);
2655         int level, op, optname;
2656
2657         if (sopt) {
2658                 level = sopt->sopt_level;
2659                 op = sopt->sopt_dir;
2660                 optname = sopt->sopt_name;
2661                 optlen = sopt->sopt_valsize;
2662         } else
2663                 level = op = optname = optlen = 0;
2664
2665         if (level != IPPROTO_ICMPV6) {
2666                 return EINVAL;
2667         }
2668
2669         switch (op) {
2670         case PRCO_SETOPT:
2671                 switch (optname) {
2672                 case ICMP6_FILTER:
2673                     {
2674                         struct icmp6_filter ic6f;
2675
2676                         if (optlen != sizeof(ic6f)) {
2677                                 error = EMSGSIZE;
2678                                 break;
2679                         }
2680                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2681                         if (error == 0) {
2682                                 INP_WLOCK(inp);
2683                                 *inp->in6p_icmp6filt = ic6f;
2684                                 INP_WUNLOCK(inp);
2685                         }
2686                         break;
2687                     }
2688
2689                 default:
2690                         error = ENOPROTOOPT;
2691                         break;
2692                 }
2693                 break;
2694
2695         case PRCO_GETOPT:
2696                 switch (optname) {
2697                 case ICMP6_FILTER:
2698                     {
2699                         struct icmp6_filter ic6f;
2700
2701                         INP_RLOCK(inp);
2702                         ic6f = *inp->in6p_icmp6filt;
2703                         INP_RUNLOCK(inp);
2704                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2705                         break;
2706                     }
2707
2708                 default:
2709                         error = ENOPROTOOPT;
2710                         break;
2711                 }
2712                 break;
2713         }
2714
2715         return (error);
2716 }
2717
2718 /*
2719  * Perform rate limit check.
2720  * Returns 0 if it is okay to send the icmp6 packet.
2721  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2722  * limitation.
2723  *
2724  * XXX per-destination/type check necessary?
2725  *
2726  * dst - not used at this moment
2727  * type - not used at this moment
2728  * code - not used at this moment
2729  */
2730 int
2731 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2732     const int code)
2733 {
2734         int ret;
2735
2736         ret = 0;        /* okay to send */
2737
2738         /* PPS limit */
2739         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2740             V_icmp6errppslim)) {
2741                 /* The packet is subject to rate limit */
2742                 ret++;
2743         }
2744
2745         return ret;
2746 }