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