sys/netinet6/icmp6.c

   1 /*      $FreeBSD: src/sys/netinet6/icmp6.c,v 1.6.2.13 2003/05/06 06:46:58 suz Exp $     */
   2 /*      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */
   3
   4 /*
   5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 /*
  34  * Copyright (c) 1982, 1986, 1988, 1993
  35  *      The Regents of the University of California.  All rights reserved.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 3. All advertising materials mentioning features or use of this software
  46  *    must display the following acknowledgement:
  47  *      This product includes software developed by the University of
  48  *      California, Berkeley and its contributors.
  49  * 4. Neither the name of the University nor the names of its contributors
  50  *    may be used to endorse or promote products derived from this software
  51  *    without specific prior written permission.
  52  *
  53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  63  * SUCH DAMAGE.
  64  *
  65  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  66  */
  67
  68 #include "opt_inet.h"
  69 #include "opt_inet6.h"
  70 #include "opt_ipsec.h"
  71
  72 #include <sys/param.h>
  73 #include <sys/systm.h>
  74 #include <sys/malloc.h>
  75 #include <sys/mbuf.h>
  76 #include <sys/protosw.h>
  77 #include <sys/socket.h>
  78 #include <sys/socketvar.h>
  79 #include <sys/socketops.h>
  80 #include <sys/time.h>
  81 #include <sys/kernel.h>
  82 #include <sys/syslog.h>
  83 #include <sys/domain.h>
  84
  85 #include <sys/thread2.h>
  86 #include <sys/msgport2.h>
  87
  88 #include <net/if.h>
  89 #include <net/route.h>
  90 #include <net/if_dl.h>
  91 #include <net/if_types.h>
  92
  93 #include <netinet/in.h>
  94 #include <netinet/in_var.h>
  95 #include <netinet/ip6.h>
  96 #include <netinet6/ip6_var.h>
  97 #include <netinet/icmp6.h>
  98 #include <netinet6/mld6_var.h>
  99 #include <netinet/in_pcb.h>
 100 #include <netinet6/in6_pcb.h>
 101 #include <netinet6/nd6.h>
 102 #include <netinet6/in6_ifattach.h>
 103 #include <netinet6/ip6protosw.h>
 104
 105 #ifdef IPSEC
 106 #include <netinet6/ipsec.h>
 107 #include <netproto/key/key.h>
 108 #endif
 109
 110 #ifdef FAST_IPSEC
 111 #include <netproto/ipsec/ipsec.h>
 112 #include <netproto/ipsec/key.h>
 113 #define IPSEC
 114 #endif
 115
 116 #include <net/net_osdep.h>
 117
 118 #ifdef HAVE_NRL_INPCB
 119 /* inpcb members */
 120 #define in6pcb          inpcb
 121 #define in6p_laddr      inp_laddr6
 122 #define in6p_faddr      inp_faddr6
 123 #define in6p_icmp6filt  inp_icmp6filt
 124 #define in6p_route      inp_route
 125 #define in6p_socket     inp_socket
 126 #define in6p_flags      inp_flags
 127 #define in6p_moptions   inp_moptions6
 128 #define in6p_outputopts inp_outputopts6
 129 #define in6p_ip6        inp_ipv6
 130 #define in6p_flowinfo   inp_flowinfo
 131 #define in6p_sp         inp_sp
 132 #define in6p_next       inp_next
 133 #define in6p_prev       inp_prev
 134 /* function names */
 135 #define in6_pcbdetach   in_pcbdetach
 136 #define in6_rtchange    in_rtchange
 137
 138 /*
 139  * for KAME src sync over BSD*'s. XXX: FreeBSD (>=3) are VERY different from
 140  * others...
 141  */
 142 #define in6p_ip6_nxt    inp_ipv6.ip6_nxt
 143 #endif
 144
 145 /*
 146  * ppratecheck() is available, so define it here.
 147  */
 148 #define HAVE_PPSRATECHECK
 149
 150 extern struct domain inet6domain;
 151 extern struct protosw inet6sw[];
 152 extern u_char ip6_protox[];
 153
 154 struct icmp6stat icmp6stat;
 155
 156 extern struct inpcbinfo ripcbinfo;
 157 extern int icmp6errppslim;
 158 static int icmp6errpps_count = 0;
 159 static struct timeval icmp6errppslim_last;
 160 extern int icmp6_nodeinfo;
 161
 162 static void icmp6_errcount (struct icmp6errstat *, int, int);
 163 static int icmp6_rip6_input (struct mbuf **, int);
 164 static int icmp6_ratelimit (const struct in6_addr *, const int, const int);
 165 static const char *icmp6_redirect_diag (struct in6_addr *,
 166         struct in6_addr *, struct in6_addr *);
 167 #ifndef HAVE_PPSRATECHECK
 168 static int ppsratecheck (struct timeval *, int *, int);
 169 #endif
 170 static struct mbuf *ni6_input (struct mbuf *, int);
 171 static struct mbuf *ni6_nametodns (const char *, int, int);
 172 static int ni6_dnsmatch (const char *, int, const char *, int);
 173 static int ni6_addrs (struct icmp6_nodeinfo *, struct mbuf *,
 174                           struct ifnet **, char *);
 175 static int ni6_store_addrs (struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 176                                 struct ifnet *, int);
 177 static int icmp6_notify_error (struct mbuf *, int, int, int);
 178
 179 #ifdef COMPAT_RFC1885
 180 static struct route_in6 icmp6_reflect_rt;
 181 #endif
 182
 183
 184 void
 185 icmp6_init(void)
 186 {
 187         mld6_init();
 188 }
 189
 190 static void
 191 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
 192 {
 193         switch (type) {
 194         case ICMP6_DST_UNREACH:
 195                 switch (code) {
 196                 case ICMP6_DST_UNREACH_NOROUTE:
 197                         stat->icp6errs_dst_unreach_noroute++;
 198                         return;
 199                 case ICMP6_DST_UNREACH_ADMIN:
 200                         stat->icp6errs_dst_unreach_admin++;
 201                         return;
 202                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 203                         stat->icp6errs_dst_unreach_beyondscope++;
 204                         return;
 205                 case ICMP6_DST_UNREACH_ADDR:
 206                         stat->icp6errs_dst_unreach_addr++;
 207                         return;
 208                 case ICMP6_DST_UNREACH_NOPORT:
 209                         stat->icp6errs_dst_unreach_noport++;
 210                         return;
 211                 }
 212                 break;
 213         case ICMP6_PACKET_TOO_BIG:
 214                 stat->icp6errs_packet_too_big++;
 215                 return;
 216         case ICMP6_TIME_EXCEEDED:
 217                 switch (code) {
 218                 case ICMP6_TIME_EXCEED_TRANSIT:
 219                         stat->icp6errs_time_exceed_transit++;
 220                         return;
 221                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 222                         stat->icp6errs_time_exceed_reassembly++;
 223                         return;
 224                 }
 225                 break;
 226         case ICMP6_PARAM_PROB:
 227                 switch (code) {
 228                 case ICMP6_PARAMPROB_HEADER:
 229                         stat->icp6errs_paramprob_header++;
 230                         return;
 231                 case ICMP6_PARAMPROB_NEXTHEADER:
 232                         stat->icp6errs_paramprob_nextheader++;
 233                         return;
 234                 case ICMP6_PARAMPROB_OPTION:
 235                         stat->icp6errs_paramprob_option++;
 236                         return;
 237                 }
 238                 break;
 239         case ND_REDIRECT:
 240                 stat->icp6errs_redirect++;
 241                 return;
 242         }
 243         stat->icp6errs_unknown++;
 244 }
 245
 246 /*
 247  * Generate an error packet of type error in response to bad IP6 packet.
 248  */
 249 void
 250 icmp6_error(struct mbuf *m, int type, int code, int param)
 251 {
 252         struct ip6_hdr *oip6, *nip6;
 253         struct icmp6_hdr *icmp6;
 254         u_int preplen;
 255         int off;
 256         int nxt;
 257
 258         icmp6stat.icp6s_error++;
 259
 260         /* count per-type-code statistics */
 261         icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
 262
 263 #ifdef M_DECRYPTED      /*not openbsd*/
 264         if (m->m_flags & M_DECRYPTED) {
 265                 icmp6stat.icp6s_canterror++;
 266                 goto freeit;
 267         }
 268 #endif
 269
 270 #ifndef PULLDOWN_TEST
 271         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 272 #else
 273         if (m->m_len < sizeof(struct ip6_hdr)) {
 274                 m = m_pullup(m, sizeof(struct ip6_hdr));
 275                 if (m == NULL)
 276                         return;
 277         }
 278 #endif
 279         oip6 = mtod(m, struct ip6_hdr *);
 280
 281         /*
 282          * Multicast destination check. For unrecognized option errors,
 283          * this check has already done in ip6_unknown_opt(), so we can
 284          * check only for other errors.
 285          */
 286         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 287              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 288             (type != ICMP6_PACKET_TOO_BIG &&
 289              (type != ICMP6_PARAM_PROB ||
 290               code != ICMP6_PARAMPROB_OPTION)))
 291                 goto freeit;
 292
 293         /* Source address check. XXX: the case of anycast source? */
 294         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 295             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 296                 goto freeit;
 297
 298         /*
 299          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 300          * don't do it.
 301          */
 302         nxt = -1;
 303         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 304         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 305                 struct icmp6_hdr *icp;
 306
 307 #ifndef PULLDOWN_TEST
 308                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 309                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 310 #else
 311                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 312                         sizeof(*icp));
 313                 if (icp == NULL) {
 314                         icmp6stat.icp6s_tooshort++;
 315                         return;
 316                 }
 317 #endif
 318                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 319                     icp->icmp6_type == ND_REDIRECT) {
 320                         /*
 321                          * ICMPv6 error
 322                          * Special case: for redirect (which is
 323                          * informational) we must not send icmp6 error.
 324                          */
 325                         icmp6stat.icp6s_canterror++;
 326                         goto freeit;
 327                 } else {
 328                         /* ICMPv6 informational - send the error */
 329                 }
 330         } else {
 331                 /* non-ICMPv6 - send the error */
 332         }
 333
 334         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 335
 336         /* Finally, do rate limitation check. */
 337         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 338                 icmp6stat.icp6s_toofreq++;
 339                 goto freeit;
 340         }
 341
 342         /*
 343          * OK, ICMP6 can be generated.
 344          */
 345
 346         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 347                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 348
 349         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 350         M_PREPEND(m, preplen, MB_DONTWAIT);
 351         if (m && m->m_len < preplen)
 352                 m = m_pullup(m, preplen);
 353         if (m == NULL) {
 354                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 355                 return;
 356         }
 357
 358         nip6 = mtod(m, struct ip6_hdr *);
 359         nip6->ip6_src  = oip6->ip6_src;
 360         nip6->ip6_dst  = oip6->ip6_dst;
 361
 362         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 363                 oip6->ip6_src.s6_addr16[1] = 0;
 364         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 365                 oip6->ip6_dst.s6_addr16[1] = 0;
 366
 367         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 368         icmp6->icmp6_type = type;
 369         icmp6->icmp6_code = code;
 370         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 371
 372         /*
 373          * icmp6_reflect() is designed to be in the input path.
 374          * icmp6_error() can be called from both input and outut path,
 375          * and if we are in output path rcvif could contain bogus value.
 376          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 377          * information in ip header (nip6).
 378          */
 379         m->m_pkthdr.rcvif = NULL;
 380
 381         icmp6stat.icp6s_outhist[type]++;
 382         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 383
 384         return;
 385
 386 freeit:
 387         /*
 388          * If we can't tell wheter or not we can generate ICMP6, free it.
 389          */
 390         m_freem(m);
 391 }
 392
 393 /*
 394  * Process a received ICMP6 message.
 395  */
 396 int
 397 icmp6_input(struct mbuf **mp, int *offp, int proto)
 398 {
 399         struct mbuf *m = *mp, *n;
 400         struct ip6_hdr *ip6, *nip6;
 401         struct icmp6_hdr *icmp6, *nicmp6;
 402         int off = *offp;
 403         int icmp6len = m->m_pkthdr.len - *offp;
 404         int code, sum, noff;
 405
 406 #ifndef PULLDOWN_TEST
 407         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 408         /* m might change if M_LOOP.  So, call mtod after this */
 409 #endif
 410
 411         /*
 412          * Locate icmp6 structure in mbuf, and check
 413          * that not corrupted and of at least minimum length
 414          */
 415
 416         ip6 = mtod(m, struct ip6_hdr *);
 417         if (icmp6len < sizeof(struct icmp6_hdr)) {
 418                 icmp6stat.icp6s_tooshort++;
 419                 goto freeit;
 420         }
 421
 422         /*
 423          * calculate the checksum
 424          */
 425 #ifndef PULLDOWN_TEST
 426         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 427 #else
 428         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 429         if (icmp6 == NULL) {
 430                 icmp6stat.icp6s_tooshort++;
 431                 return IPPROTO_DONE;
 432         }
 433 #endif
 434         code = icmp6->icmp6_code;
 435
 436         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 437                 nd6log((LOG_ERR,
 438                     "ICMP6 checksum error(%d|%x) %s\n",
 439                     icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
 440                 icmp6stat.icp6s_checksum++;
 441                 goto freeit;
 442         }
 443
 444         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 445                 /*
 446                  * Deliver very specific ICMP6 type only.
 447                  * This is important to deilver TOOBIG.  Otherwise PMTUD
 448                  * will not work.
 449                  */
 450                 switch (icmp6->icmp6_type) {
 451                 case ICMP6_DST_UNREACH:
 452                 case ICMP6_PACKET_TOO_BIG:
 453                 case ICMP6_TIME_EXCEEDED:
 454                         break;
 455                 default:
 456                         goto freeit;
 457                 }
 458         }
 459
 460         icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
 461         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
 462         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 463                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
 464
 465         switch (icmp6->icmp6_type) {
 466         case ICMP6_DST_UNREACH:
 467                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
 468                 switch (code) {
 469                 case ICMP6_DST_UNREACH_NOROUTE:
 470                         code = PRC_UNREACH_NET;
 471                         break;
 472                 case ICMP6_DST_UNREACH_ADMIN:
 473                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
 474                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 475                         break;
 476                 case ICMP6_DST_UNREACH_ADDR:
 477                         code = PRC_HOSTDEAD;
 478                         break;
 479 #ifdef COMPAT_RFC1885
 480                 case ICMP6_DST_UNREACH_NOTNEIGHBOR:
 481                         code = PRC_UNREACH_SRCFAIL;
 482                         break;
 483 #else
 484                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 485                         /* I mean "source address was incorrect." */
 486                         code = PRC_PARAMPROB;
 487                         break;
 488 #endif
 489                 case ICMP6_DST_UNREACH_NOPORT:
 490                         code = PRC_UNREACH_PORT;
 491                         break;
 492                 default:
 493                         goto badcode;
 494                 }
 495                 goto deliver;
 496                 break;
 497
 498         case ICMP6_PACKET_TOO_BIG:
 499                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
 500                 if (code != 0)
 501                         goto badcode;
 502
 503                 code = PRC_MSGSIZE;
 504
 505                 /*
 506                  * Updating the path MTU will be done after examining
 507                  * intermediate extension headers.
 508                  */
 509                 goto deliver;
 510                 break;
 511
 512         case ICMP6_TIME_EXCEEDED:
 513                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
 514                 switch (code) {
 515                 case ICMP6_TIME_EXCEED_TRANSIT:
 516                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 517                         code += PRC_TIMXCEED_INTRANS;
 518                         break;
 519                 default:
 520                         goto badcode;
 521                 }
 522                 goto deliver;
 523                 break;
 524
 525         case ICMP6_PARAM_PROB:
 526                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
 527                 switch (code) {
 528                 case ICMP6_PARAMPROB_NEXTHEADER:
 529                         code = PRC_UNREACH_PROTOCOL;
 530                         break;
 531                 case ICMP6_PARAMPROB_HEADER:
 532                 case ICMP6_PARAMPROB_OPTION:
 533                         code = PRC_PARAMPROB;
 534                         break;
 535                 default:
 536                         goto badcode;
 537                 }
 538                 goto deliver;
 539                 break;
 540
 541         case ICMP6_ECHO_REQUEST:
 542                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
 543                 if (code != 0)
 544                         goto badcode;
 545                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 546                         /* Give up remote */
 547                         break;
 548                 }
 549                 if ((n->m_flags & M_EXT) ||
 550                     n->m_len < off + sizeof(struct icmp6_hdr)) {
 551                         struct mbuf *n0 = n;
 552                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 553                         int n0len;
 554
 555                         /*
 556                          * Prepare an internal mbuf. m_pullup() doesn't
 557                          * always copy the length we specified.
 558                          */
 559                         if (maxlen >= MCLBYTES) {
 560                                 /* Give up remote */
 561                                 m_freem(n0);
 562                                 break;
 563                         }
 564                         n = m_getb(maxlen, MB_DONTWAIT, n0->m_type, M_PKTHDR);
 565                         if (n == NULL) {
 566                                 /* Give up remote */
 567                                 m_freem(n0);
 568                                 break;
 569                         }
 570                         n0len = n0->m_pkthdr.len;       /* save for use below */
 571                         M_MOVE_PKTHDR(n, n0);
 572                         /*
 573                          * Copy IPv6 and ICMPv6 only.
 574                          */
 575                         nip6 = mtod(n, struct ip6_hdr *);
 576                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 577                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 578                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 579                         noff = sizeof(struct ip6_hdr);
 580                         /* new mbuf contains only ipv6+icmpv6 headers */
 581                         n->m_len = noff + sizeof(struct icmp6_hdr);
 582                         /*
 583                          * Adjust mbuf. ip6_plen will be adjusted in
 584                          * ip6_output().
 585                          */
 586                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 587                         /* recalculate complete packet size */
 588                         n->m_pkthdr.len = n0len + (noff - off);
 589                         n->m_next = n0;
 590                 } else {
 591                         nip6 = mtod(n, struct ip6_hdr *);
 592                         nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
 593                         noff = off;
 594                 }
 595                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 596                 nicmp6->icmp6_code = 0;
 597                 if (n) {
 598                         icmp6stat.icp6s_reflect++;
 599                         icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
 600                         icmp6_reflect(n, noff);
 601                 }
 602                 break;
 603
 604         case ICMP6_ECHO_REPLY:
 605                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
 606                 if (code != 0)
 607                         goto badcode;
 608                 break;
 609
 610         case MLD_LISTENER_QUERY:
 611         case MLD_LISTENER_REPORT:
 612                 if (icmp6len < sizeof(struct mld_hdr))
 613                         goto badlen;
 614                 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
 615                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
 616                 else
 617                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
 618                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 619                         /* give up local */
 620                         mld6_input(m, off);
 621                         m = NULL;
 622                         goto freeit;
 623                 }
 624                 mld6_input(n, off);
 625                 /* m stays. */
 626                 break;
 627
 628         case MLD_LISTENER_DONE:
 629                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
 630                 if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
 631                         goto badlen;
 632                 break;          /* nothing to be done in kernel */
 633
 634         case MLD_MTRACE_RESP:
 635         case MLD_MTRACE:
 636                 /* XXX: these two are experimental.  not officially defind. */
 637                 /* XXX: per-interface statistics? */
 638                 break;          /* just pass it to applications */
 639
 640         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 641             {
 642                 enum { WRU, FQDN } mode;
 643
 644                 if (!icmp6_nodeinfo)
 645                         break;
 646
 647                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 648                         mode = WRU;
 649                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 650                         mode = FQDN;
 651                 else
 652                         goto badlen;
 653
 654 #define hostnamelen     strlen(hostname)
 655                 if (mode == FQDN) {
 656 #ifndef PULLDOWN_TEST
 657                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 658                                          IPPROTO_DONE);
 659 #endif
 660                         n = m_copy(m, 0, M_COPYALL);
 661                         if (n)
 662                                 n = ni6_input(n, off);
 663                         /* XXX meaningless if n == NULL */
 664                         noff = sizeof(struct ip6_hdr);
 665                 } else {
 666                         u_char *p;
 667                         int maxlen, maxhlen;
 668
 669                         if ((icmp6_nodeinfo & 5) != 5)
 670                                 break;
 671
 672                         if (code != 0)
 673                                 goto badcode;
 674                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 675                         if (maxlen >= MCLBYTES) {
 676                                 /* Give up remote */
 677                                 break;
 678                         }
 679                         n = m_getb(maxlen, MB_DONTWAIT, m->m_type, M_PKTHDR);
 680                         if (n == NULL) {
 681                                 /* Give up remote */
 682                                 break;
 683                         }
 684                         if (!m_dup_pkthdr(n, m, MB_DONTWAIT)) {
 685                                 /*
 686                                  * Previous code did a blind M_COPY_PKTHDR
 687                                  * and said "just for rcvif".  If true, then
 688                                  * we could tolerate the dup failing (due to
 689                                  * the deep copy of the tag chain).  For now
 690                                  * be conservative and just fail.
 691                                  */
 692                                 m_free(n);
 693                                 break;
 694                         }
 695                         n->m_len = 0;
 696                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 697                         if (maxhlen > hostnamelen)
 698                                 maxhlen = hostnamelen;
 699                         /*
 700                          * Copy IPv6 and ICMPv6 only.
 701                          */
 702                         nip6 = mtod(n, struct ip6_hdr *);
 703                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 704                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 705                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 706                         p = (u_char *)(nicmp6 + 1);
 707                         bzero(p, 4);
 708                         bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
 709                         noff = sizeof(struct ip6_hdr);
 710                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 711                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 712                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 713                         nicmp6->icmp6_code = 0;
 714                 }
 715 #undef hostnamelen
 716                 if (n) {
 717                         icmp6stat.icp6s_reflect++;
 718                         icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
 719                         icmp6_reflect(n, noff);
 720                 }
 721                 break;
 722             }
 723
 724         case ICMP6_WRUREPLY:
 725                 if (code != 0)
 726                         goto badcode;
 727                 break;
 728
 729         case ND_ROUTER_SOLICIT:
 730                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
 731                 if (code != 0)
 732                         goto badcode;
 733                 if (icmp6len < sizeof(struct nd_router_solicit))
 734                         goto badlen;
 735                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 736                         /* give up local */
 737                         nd6_rs_input(m, off, icmp6len);
 738                         m = NULL;
 739                         goto freeit;
 740                 }
 741                 nd6_rs_input(n, off, icmp6len);
 742                 /* m stays. */
 743                 break;
 744
 745         case ND_ROUTER_ADVERT:
 746                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
 747                 if (code != 0)
 748                         goto badcode;
 749                 if (icmp6len < sizeof(struct nd_router_advert))
 750                         goto badlen;
 751                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 752                         /* give up local */
 753                         nd6_ra_input(m, off, icmp6len);
 754                         m = NULL;
 755                         goto freeit;
 756                 }
 757                 nd6_ra_input(n, off, icmp6len);
 758                 /* m stays. */
 759                 break;
 760
 761         case ND_NEIGHBOR_SOLICIT:
 762                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
 763                 if (code != 0)
 764                         goto badcode;
 765                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 766                         goto badlen;
 767                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 768                         /* give up local */
 769                         nd6_ns_input(m, off, icmp6len);
 770                         m = NULL;
 771                         goto freeit;
 772                 }
 773                 nd6_ns_input(n, off, icmp6len);
 774                 /* m stays. */
 775                 break;
 776
 777         case ND_NEIGHBOR_ADVERT:
 778                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
 779                 if (code != 0)
 780                         goto badcode;
 781                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 782                         goto badlen;
 783                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 784                         /* give up local */
 785                         nd6_na_input(m, off, icmp6len);
 786                         m = NULL;
 787                         goto freeit;
 788                 }
 789                 nd6_na_input(n, off, icmp6len);
 790                 /* m stays. */
 791                 break;
 792
 793         case ND_REDIRECT:
 794                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
 795                 if (code != 0)
 796                         goto badcode;
 797                 if (icmp6len < sizeof(struct nd_redirect))
 798                         goto badlen;
 799                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 800                         /* give up local */
 801                         icmp6_redirect_input(m, off);
 802                         m = NULL;
 803                         goto freeit;
 804                 }
 805                 icmp6_redirect_input(n, off);
 806                 /* m stays. */
 807                 break;
 808
 809         case ICMP6_ROUTER_RENUMBERING:
 810                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 811                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 812                         goto badcode;
 813                 if (icmp6len < sizeof(struct icmp6_router_renum))
 814                         goto badlen;
 815                 break;
 816
 817         default:
 818                 nd6log((LOG_DEBUG,
 819                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 820                     icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
 821                     ip6_sprintf(&ip6->ip6_dst),
 822                     m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
 823                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 824                         /* ICMPv6 error: MUST deliver it by spec... */
 825                         code = PRC_NCMDS;
 826                         /* deliver */
 827                 } else {
 828                         /* ICMPv6 informational: MUST not deliver */
 829                         break;
 830                 }
 831         deliver:
 832                 if (icmp6_notify_error(m, off, icmp6len, code)) {
 833                         /* In this case, m should've been freed. */
 834                         return (IPPROTO_DONE);
 835                 }
 836                 break;
 837
 838         badcode:
 839                 icmp6stat.icp6s_badcode++;
 840                 break;
 841
 842         badlen:
 843                 icmp6stat.icp6s_badlen++;
 844                 break;
 845         }
 846
 847         /* deliver the packet to appropriate sockets */
 848         icmp6_rip6_input(&m, *offp);
 849
 850         return IPPROTO_DONE;
 851
 852 freeit:
 853         m_freem(m);
 854         return IPPROTO_DONE;
 855 }
 856
 857 static int
 858 icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code)
 859 {
 860         struct icmp6_hdr *icmp6;
 861         struct ip6_hdr *eip6;
 862         u_int32_t notifymtu;
 863         struct sockaddr_in6 icmp6src, icmp6dst;
 864
 865         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 866                 icmp6stat.icp6s_tooshort++;
 867                 goto freeit;
 868         }
 869 #ifndef PULLDOWN_TEST
 870         IP6_EXTHDR_CHECK(m, off,
 871                          sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
 872                          -1);
 873         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 874 #else
 875         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 876                        sizeof(*icmp6) + sizeof(struct ip6_hdr));
 877         if (icmp6 == NULL) {
 878                 icmp6stat.icp6s_tooshort++;
 879                 return (-1);
 880         }
 881 #endif
 882         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 883
 884         /* Detect the upper level protocol */
 885         {
 886                 u_int8_t nxt = eip6->ip6_nxt;
 887                 int eoff = off + sizeof(struct icmp6_hdr) +
 888                         sizeof(struct ip6_hdr);
 889                 struct ip6ctlparam ip6cp;
 890                 struct in6_addr *finaldst = NULL;
 891                 int icmp6type = icmp6->icmp6_type;
 892                 struct ip6_frag *fh;
 893                 struct ip6_rthdr *rth;
 894                 int rthlen;
 895
 896                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 897                         struct ip6_ext *eh;
 898
 899                         switch (nxt) {
 900                         case IPPROTO_HOPOPTS:
 901                         case IPPROTO_DSTOPTS:
 902                         case IPPROTO_AH:
 903 #ifndef PULLDOWN_TEST
 904                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 905                                                  sizeof(struct ip6_ext),
 906                                                  -1);
 907                                 eh = (struct ip6_ext *)(mtod(m, caddr_t)
 908                                                         + eoff);
 909 #else
 910                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 911                                                eoff, sizeof(*eh));
 912                                 if (eh == NULL) {
 913                                         icmp6stat.icp6s_tooshort++;
 914                                         return (-1);
 915                                 }
 916 #endif
 917
 918                                 if (nxt == IPPROTO_AH)
 919                                         eoff += (eh->ip6e_len + 2) << 2;
 920                                 else
 921                                         eoff += (eh->ip6e_len + 1) << 3;
 922                                 nxt = eh->ip6e_nxt;
 923                                 break;
 924                         case IPPROTO_ROUTING:
 925                                 /*
 926                                  * When the erroneous packet contains a
 927                                  * routing header, we should examine the
 928                                  * header to determine the final destination.
 929                                  * Otherwise, we can't properly update
 930                                  * information that depends on the final
 931                                  * destination (e.g. path MTU).
 932                                  */
 933 #ifndef PULLDOWN_TEST
 934                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
 935                                                  -1);
 936                                 rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
 937                                                            + eoff);
 938 #else
 939                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 940                                                eoff, sizeof(*rth));
 941                                 if (rth == NULL) {
 942                                         icmp6stat.icp6s_tooshort++;
 943                                         return (-1);
 944                                 }
 945 #endif
 946                                 rthlen = (rth->ip6r_len + 1) << 3;
 947                                 eoff += rthlen;
 948                                 nxt = rth->ip6r_nxt;
 949                                 break;
 950                         case IPPROTO_FRAGMENT:
 951 #ifndef PULLDOWN_TEST
 952                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 953                                                  sizeof(struct ip6_frag),
 954                                                  -1);
 955                                 fh = (struct ip6_frag *)(mtod(m, caddr_t)
 956                                                          + eoff);
 957 #else
 958                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
 959                                                eoff, sizeof(*fh));
 960                                 if (fh == NULL) {
 961                                         icmp6stat.icp6s_tooshort++;
 962                                         return (-1);
 963                                 }
 964 #endif
 965                                 /*
 966                                  * Data after a fragment header is meaningless
 967                                  * unless it is the first fragment, but
 968                                  * we'll go to the notify label for path MTU
 969                                  * discovery.
 970                                  */
 971                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
 972                                         goto notify;
 973
 974                                 eoff += sizeof(struct ip6_frag);
 975                                 nxt = fh->ip6f_nxt;
 976                                 break;
 977                         default:
 978                                 /*
 979                                  * This case includes ESP and the No Next
 980                                  * Header.  In such cases going to the notify
 981                                  * label does not have any meaning
 982                                  * (i.e. pr_ctlinput will be NULL), but we go
 983                                  * anyway since we might have to update
 984                                  * path MTU information.
 985                                  */
 986                                 goto notify;
 987                         }
 988                 }
 989           notify:
 990 #ifndef PULLDOWN_TEST
 991                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 992 #else
 993                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 994                                sizeof(*icmp6) + sizeof(struct ip6_hdr));
 995                 if (icmp6 == NULL) {
 996                         icmp6stat.icp6s_tooshort++;
 997                         return (-1);
 998                 }
 999 #endif
1000
1001                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1002                 bzero(&icmp6dst, sizeof(icmp6dst));
1003                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1004                 icmp6dst.sin6_family = AF_INET6;
1005                 if (finaldst == NULL)
1006                         icmp6dst.sin6_addr = eip6->ip6_dst;
1007                 else
1008                         icmp6dst.sin6_addr = *finaldst;
1009                 icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1010                                                           &icmp6dst.sin6_addr);
1011                 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1012                                    NULL, NULL)) {
1013                         /* should be impossbile */
1014                         nd6log((LOG_DEBUG,
1015                             "icmp6_notify_error: in6_embedscope failed\n"));
1016                         goto freeit;
1017                 }
1018
1019                 /*
1020                  * retrieve parameters from the inner IPv6 header, and convert
1021                  * them into sockaddr structures.
1022                  */
1023                 bzero(&icmp6src, sizeof(icmp6src));
1024                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1025                 icmp6src.sin6_family = AF_INET6;
1026                 icmp6src.sin6_addr = eip6->ip6_src;
1027                 icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1028                                                           &icmp6src.sin6_addr);
1029                 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1030                                    NULL, NULL)) {
1031                         /* should be impossbile */
1032                         nd6log((LOG_DEBUG,
1033                             "icmp6_notify_error: in6_embedscope failed\n"));
1034                         goto freeit;
1035                 }
1036                 icmp6src.sin6_flowinfo =
1037                         (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1038
1039                 if (finaldst == NULL)
1040                         finaldst = &eip6->ip6_dst;
1041                 ip6cp.ip6c_m = m;
1042                 ip6cp.ip6c_icmp6 = icmp6;
1043                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1044                 ip6cp.ip6c_off = eoff;
1045                 ip6cp.ip6c_finaldst = finaldst;
1046                 ip6cp.ip6c_src = &icmp6src;
1047                 ip6cp.ip6c_nxt = nxt;
1048
1049                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1050                         notifymtu = ntohl(icmp6->icmp6_mtu);
1051                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1052                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1053                 }
1054
1055                 so_pru_ctlinput(
1056                         &inet6sw[ip6_protox[nxt]],
1057                         code, (struct sockaddr *)&icmp6dst, &ip6cp);
1058         }
1059         return (0);
1060
1061 freeit:
1062         m_freem(m);
1063         return (-1);
1064 }
1065
1066 void
1067 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1068 {
1069         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1070         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1071         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1072         u_int mtu = ntohl(icmp6->icmp6_mtu);
1073         struct rtentry *rt = NULL;
1074         struct sockaddr_in6 sin6;
1075
1076         if (!validated)
1077                 return;
1078
1079         bzero(&sin6, sizeof(sin6));
1080         sin6.sin6_family = PF_INET6;
1081         sin6.sin6_len = sizeof(struct sockaddr_in6);
1082         sin6.sin6_addr = *dst;
1083         /* XXX normally, this won't happen */
1084         if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1085                 sin6.sin6_addr.s6_addr16[1] =
1086                     htons(m->m_pkthdr.rcvif->if_index);
1087         }
1088         /* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1089         rt = rtpurelookup((struct sockaddr *)&sin6);
1090         if (rt != NULL && (rt->rt_flags & RTF_HOST) &&
1091             !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
1092                 if (mtu < IPV6_MMTU) {                          /* XXX */
1093                         rt->rt_rmx.rmx_locks |= RTV_MTU;
1094                 } else if (mtu < rt->rt_ifp->if_mtu &&
1095                            rt->rt_rmx.rmx_mtu > mtu) {
1096                         icmp6stat.icp6s_pmtuchg++;
1097                         rt->rt_rmx.rmx_mtu = mtu;
1098                 }
1099         }
1100         if (rt)
1101                 --rt->rt_refcnt;
1102 }
1103
1104 /*
1105  * Process a Node Information Query packet, based on
1106  * draft-ietf-ipngwg-icmp-name-lookups-07.
1107  *
1108  * Spec incompatibilities:
1109  * - IPv6 Subject address handling
1110  * - IPv4 Subject address handling support missing
1111  * - Proxy reply (answer even if it's not for me)
1112  * - joins NI group address at in6_ifattach() time only, does not cope
1113  *   with hostname changes by sethostname(3)
1114  */
1115 #define hostnamelen     strlen(hostname)
1116 static struct mbuf *
1117 ni6_input(struct mbuf *m, int off)
1118 {
1119         struct icmp6_nodeinfo *ni6, *nni6;
1120         struct mbuf *n = NULL;
1121         u_int16_t qtype;
1122         int subjlen;
1123         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1124         struct ni_reply_fqdn *fqdn;
1125         int addrs;              /* for NI_QTYPE_NODEADDR */
1126         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1127         struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1128         struct sockaddr_in6 sin6_d; /* XXX: we should retrieve this from m_aux */
1129         struct ip6_hdr *ip6;
1130         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1131         char *subj = NULL;
1132         struct in6_ifaddr *ia6 = NULL;
1133
1134         ip6 = mtod(m, struct ip6_hdr *);
1135 #ifndef PULLDOWN_TEST
1136         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1137 #else
1138         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1139         if (ni6 == NULL) {
1140                 /* m is already reclaimed */
1141                 return NULL;
1142         }
1143 #endif
1144
1145         /*
1146          * Validate IPv6 destination address.
1147          *
1148          * The Responder must discard the Query without further processing
1149          * unless it is one of the Responder's unicast or anycast addresses, or
1150          * a link-local scope multicast address which the Responder has joined.
1151          * [icmp-name-lookups-07, Section 4.]
1152          */
1153         bzero(&sin6, sizeof(sin6));
1154         sin6.sin6_family = AF_INET6;
1155         sin6.sin6_len = sizeof(struct sockaddr_in6);
1156         bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1157         /* XXX scopeid */
1158         if ((ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)&sin6)) != NULL) {
1159                 /* unicast/anycast, fine */
1160                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1161                     (icmp6_nodeinfo & 4) == 0) {
1162                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1163                                 "a temporary address in %s:%d",
1164                                __FILE__, __LINE__));
1165                         goto bad;
1166                 }
1167         } else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1168                 ; /* link-local multicast, fine */
1169         else
1170                 goto bad;
1171
1172         /* validate query Subject field. */
1173         qtype = ntohs(ni6->ni_qtype);
1174         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1175         switch (qtype) {
1176         case NI_QTYPE_NOOP:
1177         case NI_QTYPE_SUPTYPES:
1178                 /* 07 draft */
1179                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1180                         break;
1181                 /* FALLTHROUGH */
1182         case NI_QTYPE_FQDN:
1183         case NI_QTYPE_NODEADDR:
1184                 switch (ni6->ni_code) {
1185                 case ICMP6_NI_SUBJ_IPV6:
1186 #if ICMP6_NI_SUBJ_IPV6 != 0
1187                 case 0:
1188 #endif
1189                         /*
1190                          * backward compatibility - try to accept 03 draft
1191                          * format, where no Subject is present.
1192                          */
1193                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1194                             subjlen == 0) {
1195                                 oldfqdn++;
1196                                 break;
1197                         }
1198 #if ICMP6_NI_SUBJ_IPV6 != 0
1199                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1200                                 goto bad;
1201 #endif
1202
1203                         if (subjlen != sizeof(sin6.sin6_addr))
1204                                 goto bad;
1205
1206                         /*
1207                          * Validate Subject address.
1208                          *
1209                          * Not sure what exactly "address belongs to the node"
1210                          * means in the spec, is it just unicast, or what?
1211                          *
1212                          * At this moment we consider Subject address as
1213                          * "belong to the node" if the Subject address equals
1214                          * to the IPv6 destination address; validation for
1215                          * IPv6 destination address should have done enough
1216                          * check for us.
1217                          *
1218                          * We do not do proxy at this moment.
1219                          */
1220                         /* m_pulldown instead of copy? */
1221                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1222                             subjlen, (caddr_t)&sin6.sin6_addr);
1223                         sin6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1224                                                               &sin6.sin6_addr);
1225                         in6_embedscope(&sin6.sin6_addr, &sin6, NULL, NULL);
1226                         bzero(&sin6_d, sizeof(sin6_d));
1227                         sin6_d.sin6_family = AF_INET6; /* not used, actually */
1228                         sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
1229                         sin6_d.sin6_addr = ip6->ip6_dst;
1230                         sin6_d.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1231                                                                 &ip6->ip6_dst);
1232                         in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL);
1233                         subj = (char *)&sin6;
1234                         if (SA6_ARE_ADDR_EQUAL(&sin6, &sin6_d))
1235                                 break;
1236
1237                         /*
1238                          * XXX if we are to allow other cases, we should really
1239                          * be careful about scope here.
1240                          * basically, we should disallow queries toward IPv6
1241                          * destination X with subject Y, if scope(X) > scope(Y).
1242                          * if we allow scope(X) > scope(Y), it will result in
1243                          * information leakage across scope boundary.
1244                          */
1245                         goto bad;
1246
1247                 case ICMP6_NI_SUBJ_FQDN:
1248                         /*
1249                          * Validate Subject name with gethostname(3).
1250                          *
1251                          * The behavior may need some debate, since:
1252                          * - we are not sure if the node has FQDN as
1253                          *   hostname (returned by gethostname(3)).
1254                          * - the code does wildcard match for truncated names.
1255                          *   however, we are not sure if we want to perform
1256                          *   wildcard match, if gethostname(3) side has
1257                          *   truncated hostname.
1258                          */
1259                         n = ni6_nametodns(hostname, hostnamelen, 0);
1260                         if (!n || n->m_next || n->m_len == 0)
1261                                 goto bad;
1262                         IP6_EXTHDR_GET(subj, char *, m,
1263                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1264                         if (subj == NULL)
1265                                 goto bad;
1266                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1267                                         n->m_len)) {
1268                                 goto bad;
1269                         }
1270                         m_freem(n);
1271                         n = NULL;
1272                         break;
1273
1274                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1275                 default:
1276                         goto bad;
1277                 }
1278                 break;
1279         }
1280
1281         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1282         switch (qtype) {
1283         case NI_QTYPE_FQDN:
1284                 if ((icmp6_nodeinfo & 1) == 0)
1285                         goto bad;
1286                 break;
1287         case NI_QTYPE_NODEADDR:
1288                 if ((icmp6_nodeinfo & 2) == 0)
1289                         goto bad;
1290                 break;
1291         }
1292
1293         /* guess reply length */
1294         switch (qtype) {
1295         case NI_QTYPE_NOOP:
1296                 break;          /* no reply data */
1297         case NI_QTYPE_SUPTYPES:
1298                 replylen += sizeof(u_int32_t);
1299                 break;
1300         case NI_QTYPE_FQDN:
1301                 /* XXX will append an mbuf */
1302                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1303                 break;
1304         case NI_QTYPE_NODEADDR:
1305                 addrs = ni6_addrs(ni6, m, &ifp, subj);
1306                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1307                                           sizeof(u_int32_t))) > MCLBYTES)
1308                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1309                 break;
1310         default:
1311                 /*
1312                  * XXX: We must return a reply with the ICMP6 code
1313                  * `unknown Qtype' in this case. However we regard the case
1314                  * as an FQDN query for backward compatibility.
1315                  * Older versions set a random value to this field,
1316                  * so it rarely varies in the defined qtypes.
1317                  * But the mechanism is not reliable...
1318                  * maybe we should obsolete older versions.
1319                  */
1320                 qtype = NI_QTYPE_FQDN;
1321                 /* XXX will append an mbuf */
1322                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1323                 oldfqdn++;
1324                 break;
1325         }
1326
1327         /* allocate an mbuf to reply. */
1328         if (replylen > MCLBYTES) {
1329                 /*
1330                  * XXX: should we try to allocate more? But MCLBYTES
1331                  * is probably much larger than IPV6_MMTU...
1332                  */
1333                 goto bad;
1334         }
1335         n = m_getb(replylen, MB_DONTWAIT, m->m_type, M_PKTHDR);
1336         if (n == NULL) {
1337                 m_freem(m);
1338                 return (NULL);
1339         }
1340         M_MOVE_PKTHDR(n, m); /* just for recvif */
1341         n->m_pkthdr.len = n->m_len = replylen;
1342
1343         /* copy mbuf header and IPv6 + Node Information base headers */
1344         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1345         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1346         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1347
1348         /* qtype dependent procedure */
1349         switch (qtype) {
1350         case NI_QTYPE_NOOP:
1351                 nni6->ni_code = ICMP6_NI_SUCCESS;
1352                 nni6->ni_flags = 0;
1353                 break;
1354         case NI_QTYPE_SUPTYPES:
1355         {
1356                 u_int32_t v;
1357                 nni6->ni_code = ICMP6_NI_SUCCESS;
1358                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1359                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1360                 v = (u_int32_t)htonl(0x0000000f);
1361                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1362                 break;
1363         }
1364         case NI_QTYPE_FQDN:
1365                 nni6->ni_code = ICMP6_NI_SUCCESS;
1366                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1367                                                 sizeof(struct ip6_hdr) +
1368                                                 sizeof(struct icmp6_nodeinfo));
1369                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1370                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1371                 /*
1372                  * XXX do we really have FQDN in variable "hostname"?
1373                  */
1374                 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1375                 if (n->m_next == NULL)
1376                         goto bad;
1377                 /* XXX we assume that n->m_next is not a chain */
1378                 if (n->m_next->m_next != NULL)
1379                         goto bad;
1380                 n->m_pkthdr.len += n->m_next->m_len;
1381                 break;
1382         case NI_QTYPE_NODEADDR:
1383         {
1384                 int lenlim, copied;
1385
1386                 nni6->ni_code = ICMP6_NI_SUCCESS;
1387                 n->m_pkthdr.len = n->m_len =
1388                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1389                 lenlim = M_TRAILINGSPACE(n);
1390                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1391                 /* XXX: reset mbuf length */
1392                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1393                         sizeof(struct icmp6_nodeinfo) + copied;
1394                 break;
1395         }
1396         default:
1397                 break;          /* XXX impossible! */
1398         }
1399
1400         nni6->ni_type = ICMP6_NI_REPLY;
1401         m_freem(m);
1402         return (n);
1403
1404 bad:
1405         m_freem(m);
1406         if (n)
1407                 m_freem(n);
1408         return (NULL);
1409 }
1410 #undef hostnamelen
1411
1412 /*
1413  * make a mbuf with DNS-encoded string.  no compression support.
1414  *
1415  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1416  * treated as truncated name (two \0 at the end).  this is a wild guess.
1417  */
1418 static struct mbuf *
1419 ni6_nametodns(const char *name, int namelen,
1420               int old) /* return pascal string if non-zero */
1421 {
1422         struct mbuf *m;
1423         char *cp, *ep;
1424         const char *p, *q;
1425         int i, len, nterm;
1426
1427         if (old)
1428                 len = namelen + 1;
1429         else
1430                 len = MCLBYTES;
1431
1432         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1433         m = m_getb(len, MB_DONTWAIT, MT_DATA, 0);
1434         if (!m)
1435                 goto fail;
1436
1437         if (old) {
1438                 m->m_len = len;
1439                 *mtod(m, char *) = namelen;
1440                 bcopy(name, mtod(m, char *) + 1, namelen);
1441                 return m;
1442         } else {
1443                 m->m_len = 0;
1444                 cp = mtod(m, char *);
1445                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1446
1447                 /* if not certain about my name, return empty buffer */
1448                 if (namelen == 0)
1449                         return m;
1450
1451                 /*
1452                  * guess if it looks like shortened hostname, or FQDN.
1453                  * shortened hostname needs two trailing "\0".
1454                  */
1455                 i = 0;
1456                 for (p = name; p < name + namelen; p++) {
1457                         if (*p && *p == '.')
1458                                 i++;
1459                 }
1460                 if (i < 2)
1461                         nterm = 2;
1462                 else
1463                         nterm = 1;
1464
1465                 p = name;
1466                 while (cp < ep && p < name + namelen) {
1467                         i = 0;
1468                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1469                                 i++;
1470                         /* result does not fit into mbuf */
1471                         if (cp + i + 1 >= ep)
1472                                 goto fail;
1473                         /*
1474                          * DNS label length restriction, RFC1035 page 8.
1475                          * "i == 0" case is included here to avoid returning
1476                          * 0-length label on "foo..bar".
1477                          */
1478                         if (i <= 0 || i >= 64)
1479                                 goto fail;
1480                         *cp++ = i;
1481                         bcopy(p, cp, i);
1482                         cp += i;
1483                         p = q;
1484                         if (p < name + namelen && *p == '.')
1485                                 p++;
1486                 }
1487                 /* termination */
1488                 if (cp + nterm >= ep)
1489                         goto fail;
1490                 while (nterm-- > 0)
1491                         *cp++ = '\0';
1492                 m->m_len = cp - mtod(m, char *);
1493                 return m;
1494         }
1495
1496         panic("should not reach here");
1497         /* NOTREACHED */
1498
1499 fail:
1500         if (m)
1501                 m_freem(m);
1502         return NULL;
1503 }
1504
1505 /*
1506  * check if two DNS-encoded string matches.  takes care of truncated
1507  * form (with \0\0 at the end).  no compression support.
1508  * XXX upper/lowercase match (see RFC2065)
1509  */
1510 static int
1511 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1512 {
1513         const char *a0, *b0;
1514         int l;
1515
1516         /* simplest case - need validation? */
1517         if (alen == blen && bcmp(a, b, alen) == 0)
1518                 return 1;
1519
1520         a0 = a;
1521         b0 = b;
1522
1523         /* termination is mandatory */
1524         if (alen < 2 || blen < 2)
1525                 return 0;
1526         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1527                 return 0;
1528         alen--;
1529         blen--;
1530
1531         while (a - a0 < alen && b - b0 < blen) {
1532                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1533                         return 0;
1534
1535                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1536                         return 0;
1537                 /* we don't support compression yet */
1538                 if (a[0] >= 64 || b[0] >= 64)
1539                         return 0;
1540
1541                 /* truncated case */
1542                 if (a[0] == 0 && a - a0 == alen - 1)
1543                         return 1;
1544                 if (b[0] == 0 && b - b0 == blen - 1)
1545                         return 1;
1546                 if (a[0] == 0 || b[0] == 0)
1547                         return 0;
1548
1549                 if (a[0] != b[0])
1550                         return 0;
1551                 l = a[0];
1552                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1553                         return 0;
1554                 if (bcmp(a + 1, b + 1, l) != 0)
1555                         return 0;
1556
1557                 a += 1 + l;
1558                 b += 1 + l;
1559         }
1560
1561         if (a - a0 == alen && b - b0 == blen)
1562                 return 1;
1563         else
1564                 return 0;
1565 }
1566
1567 /*
1568  * calculate the number of addresses to be returned in the node info reply.
1569  */
1570 static int
1571 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1572           char *subj)
1573 {
1574         struct ifnet *ifp;
1575         struct in6_ifaddr *ifa6;
1576         struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1577         int addrs = 0, addrsofif, iffound = 0;
1578         int niflags = ni6->ni_flags;
1579
1580         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1581                 switch (ni6->ni_code) {
1582                 case ICMP6_NI_SUBJ_IPV6:
1583                         if (subj == NULL) /* must be impossible... */
1584                                 return (0);
1585                         subj_ip6 = (struct sockaddr_in6 *)subj;
1586                         break;
1587                 default:
1588                         /*
1589                          * XXX: we only support IPv6 subject address for
1590                          * this Qtype.
1591                          */
1592                         return (0);
1593                 }
1594         }
1595
1596         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1597         {
1598                 struct ifaddr_container *ifac;
1599
1600                 addrsofif = 0;
1601                 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link)
1602                 {
1603                         struct ifaddr *ifa = ifac->ifa;
1604
1605                         if (ifa->ifa_addr->sa_family != AF_INET6)
1606                                 continue;
1607                         ifa6 = (struct in6_ifaddr *)ifa;
1608
1609                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1610                             IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1611                                                &ifa6->ia_addr.sin6_addr))
1612                                 iffound = 1;
1613
1614                         /*
1615                          * IPv4-mapped addresses can only be returned by a
1616                          * Node Information proxy, since they represent
1617                          * addresses of IPv4-only nodes, which perforce do
1618                          * not implement this protocol.
1619                          * [icmp-name-lookups-07, Section 5.4]
1620                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1621                          * this function at this moment.
1622                          */
1623
1624                         /* What do we have to do about ::1? */
1625                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1626                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1627                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1628                                         continue;
1629                                 break;
1630                         case IPV6_ADDR_SCOPE_SITELOCAL:
1631                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1632                                         continue;
1633                                 break;
1634                         case IPV6_ADDR_SCOPE_GLOBAL:
1635                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1636                                         continue;
1637                                 break;
1638                         default:
1639                                 continue;
1640                         }
1641
1642                         /*
1643                          * check if anycast is okay.
1644                          * XXX: just experimental.  not in the spec.
1645                          */
1646                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) &&
1647                             !(niflags & NI_NODEADDR_FLAG_ANYCAST))
1648                                 continue; /* we need only unicast addresses */
1649                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) &&
1650                             (icmp6_nodeinfo & 4) == 0) {
1651                                 continue;
1652                         }
1653                         addrsofif++; /* count the address */
1654                 }
1655                 if (iffound) {
1656                         *ifpp = ifp;
1657                         return (addrsofif);
1658                 }
1659
1660                 addrs += addrsofif;
1661         }
1662
1663         return (addrs);
1664 }
1665
1666 static int
1667 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1668                 struct ifnet *ifp0, int resid)
1669 {
1670         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1671         struct in6_ifaddr *ifa6;
1672         struct ifnet *ifp_dep = NULL;
1673         int copied = 0, allow_deprecated = 0;
1674         u_char *cp = (u_char *)(nni6 + 1);
1675         int niflags = ni6->ni_flags;
1676         u_int32_t ltime;
1677
1678         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1679                 return (0);     /* needless to copy */
1680
1681 again:
1682
1683         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1684         {
1685                 struct ifaddr_container *ifac;
1686
1687                 TAILQ_FOREACH(ifac, &ifp->if_addrheads[mycpuid], ifa_link) {
1688                         struct ifaddr *ifa = ifac->ifa;
1689
1690                         if (ifa->ifa_addr->sa_family != AF_INET6)
1691                                 continue;
1692                         ifa6 = (struct in6_ifaddr *)ifa;
1693
1694                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) &&
1695                             allow_deprecated == 0) {
1696                                 /*
1697                                  * prefererred address should be put before
1698                                  * deprecated addresses.
1699                                  */
1700
1701                                 /* record the interface for later search */
1702                                 if (ifp_dep == NULL)
1703                                         ifp_dep = ifp;
1704
1705                                 continue;
1706                         }
1707                         else if (!(ifa6->ia6_flags & IN6_IFF_DEPRECATED) &&
1708                                  allow_deprecated != 0)
1709                                 continue; /* we now collect deprecated addrs */
1710
1711                         /* What do we have to do about ::1? */
1712                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1713                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1714                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1715                                         continue;
1716                                 break;
1717                         case IPV6_ADDR_SCOPE_SITELOCAL:
1718                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1719                                         continue;
1720                                 break;
1721                         case IPV6_ADDR_SCOPE_GLOBAL:
1722                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1723                                         continue;
1724                                 break;
1725                         default:
1726                                 continue;
1727                         }
1728
1729                         /*
1730                          * check if anycast is okay.
1731                          * XXX: just experimental. not in the spec.
1732                          */
1733                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) &&
1734                             !(niflags & NI_NODEADDR_FLAG_ANYCAST))
1735                                 continue;
1736                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) &&
1737                             (icmp6_nodeinfo & 4) == 0) {
1738                                 continue;
1739                         }
1740
1741                         /* now we can copy the address */
1742                         if (resid < sizeof(struct in6_addr) +
1743                             sizeof(u_int32_t)) {
1744                                 /*
1745                                  * We give up much more copy.
1746                                  * Set the truncate flag and return.
1747                                  */
1748                                 nni6->ni_flags |=
1749                                         NI_NODEADDR_FLAG_TRUNCATE;
1750                                 return (copied);
1751                         }
1752
1753                         /*
1754                          * Set the TTL of the address.
1755                          * The TTL value should be one of the following
1756                          * according to the specification:
1757                          *
1758                          * 1. The remaining lifetime of a DHCP lease on the
1759                          *    address, or
1760                          * 2. The remaining Valid Lifetime of a prefix from
1761                          *    which the address was derived through Stateless
1762                          *    Autoconfiguration.
1763                          *
1764                          * Note that we currently do not support stateful
1765                          * address configuration by DHCPv6, so the former
1766                          * case can't happen.
1767                          */
1768                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1769                                 ltime = ND6_INFINITE_LIFETIME;
1770                         else {
1771                                 if (ifa6->ia6_lifetime.ia6t_expire >
1772                                     time_second)
1773                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1774                                 else
1775                                         ltime = 0;
1776                         }
1777
1778                         bcopy(&ltime, cp, sizeof(u_int32_t));
1779                         cp += sizeof(u_int32_t);
1780
1781                         /* copy the address itself */
1782                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1783                               sizeof(struct in6_addr));
1784                         /* XXX: KAME link-local hack; remove ifindex */
1785                         if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
1786                                 ((struct in6_addr *)cp)->s6_addr16[1] = 0;
1787                         cp += sizeof(struct in6_addr);
1788
1789                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1790                         copied += (sizeof(struct in6_addr) +
1791                                    sizeof(u_int32_t));
1792                 }
1793                 if (ifp0)       /* we need search only on the specified IF */
1794                         break;
1795         }
1796
1797         if (allow_deprecated == 0 && ifp_dep != NULL) {
1798                 ifp = ifp_dep;
1799                 allow_deprecated = 1;
1800
1801                 goto again;
1802         }
1803
1804         return (copied);
1805 }
1806
1807 /*
1808  * XXX almost dup'ed code with rip6_input.
1809  */
1810 static int
1811 icmp6_rip6_input(struct mbuf **mp, int  off)
1812 {
1813         struct mbuf *m = *mp;
1814         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1815         struct in6pcb *in6p;
1816         struct in6pcb *last = NULL;
1817         struct sockaddr_in6 rip6src;
1818         struct icmp6_hdr *icmp6;
1819         struct mbuf *opts = NULL;
1820
1821 #ifndef PULLDOWN_TEST
1822         /* this is assumed to be safe. */
1823         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1824 #else
1825         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1826         if (icmp6 == NULL) {
1827                 /* m is already reclaimed */
1828                 return IPPROTO_DONE;
1829         }
1830 #endif
1831
1832         bzero(&rip6src, sizeof(rip6src));
1833         rip6src.sin6_len = sizeof(struct sockaddr_in6);
1834         rip6src.sin6_family = AF_INET6;
1835         /* KAME hack: recover scopeid */
1836         in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);
1837
1838         LIST_FOREACH(in6p, &ripcbinfo.pcblisthead, inp_list)
1839         {
1840                 if (in6p->inp_flags & INP_PLACEMARKER)
1841                         continue;
1842                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1843                         continue;
1844 #ifdef HAVE_NRL_INPCB
1845                 if (!(in6p->in6p_flags & INP_IPV6))
1846                         continue;
1847 #endif
1848                 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1849                         continue;
1850                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1851                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1852                         continue;
1853                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1854                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1855                         continue;
1856                 if (in6p->in6p_icmp6filt
1857                     && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1858                                  in6p->in6p_icmp6filt))
1859                         continue;
1860                 if (last) {
1861                         struct socket *so;
1862                         struct mbuf *n;
1863
1864                         if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1865                                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1866                                         ip6_savecontrol(last, &opts, ip6, n);
1867                                 /* strip intermediate headers */
1868                                 m_adj(n, off);
1869                                 so = last->in6p_socket;
1870                                 lwkt_gettoken(&so->so_rcv.ssb_token);
1871                                 if (ssb_appendaddr(&so->so_rcv,
1872                                                  (struct sockaddr *)&rip6src,
1873                                                  n, opts) == 0) {
1874                                         /* should notify about lost packet */
1875                                         m_freem(n);
1876                                         if (opts)
1877                                                 m_freem(opts);
1878                                 } else {
1879                                         sorwakeup(so);
1880                                 }
1881                                 lwkt_reltoken(&so->so_rcv.ssb_token);
1882                                 opts = NULL;
1883                         }
1884                 }
1885                 last = in6p;
1886         }
1887         if (last) {
1888                 struct socket *so;
1889
1890                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1891                         ip6_savecontrol(last, &opts, ip6, m);
1892                 /* strip intermediate headers */
1893                 m_adj(m, off);
1894                 so = last->in6p_socket;
1895                 lwkt_gettoken(&so->so_rcv.ssb_token);
1896                 if (ssb_appendaddr(&so->so_rcv, (struct sockaddr *)&rip6src,
1897                                    m, opts) == 0) {
1898                         m_freem(m);
1899                         if (opts)
1900                                 m_freem(opts);
1901                 } else {
1902                         sorwakeup(so);
1903                 }
1904                 lwkt_reltoken(&so->so_rcv.ssb_token);
1905         } else {
1906                 m_freem(m);
1907                 ip6stat.ip6s_delivered--;
1908         }
1909         return IPPROTO_DONE;
1910 }
1911
1912 /*
1913  * Reflect the ip6 packet back to the source.
1914  * OFF points to the icmp6 header, counted from the top of the mbuf.
1915  */
1916 void
1917 icmp6_reflect(struct mbuf *m, size_t off)
1918 {
1919         struct ip6_hdr *ip6;
1920         struct icmp6_hdr *icmp6;
1921         struct in6_ifaddr *ia;
1922         struct in6_addr t, *src = NULL;
1923         int plen;
1924         int type, code;
1925         struct ifnet *outif = NULL;
1926         struct sockaddr_in6 sa6_src, sa6_dst;
1927 #ifdef COMPAT_RFC1885
1928         int mtu = IPV6_MMTU;
1929         struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
1930 #endif
1931
1932         /* too short to reflect */
1933         if (off < sizeof(struct ip6_hdr)) {
1934                 nd6log((LOG_DEBUG,
1935                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1936                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
1937                     __FILE__, __LINE__));
1938                 goto bad;
1939         }
1940
1941         /*
1942          * If there are extra headers between IPv6 and ICMPv6, strip
1943          * off that header first.
1944          */
1945 #ifdef DIAGNOSTIC
1946         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
1947                 panic("assumption failed in icmp6_reflect");
1948 #endif
1949         if (off > sizeof(struct ip6_hdr)) {
1950                 size_t l;
1951                 struct ip6_hdr nip6;
1952
1953                 l = off - sizeof(struct ip6_hdr);
1954                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
1955                 m_adj(m, l);
1956                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1957                 if (m->m_len < l) {
1958                         if ((m = m_pullup(m, l)) == NULL)
1959                                 return;
1960                 }
1961                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
1962         } else /* off == sizeof(struct ip6_hdr) */ {
1963                 size_t l;
1964                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
1965                 if (m->m_len < l) {
1966                         if ((m = m_pullup(m, l)) == NULL)
1967                                 return;
1968                 }
1969         }
1970         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
1971         ip6 = mtod(m, struct ip6_hdr *);
1972         ip6->ip6_nxt = IPPROTO_ICMPV6;
1973         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
1974         type = icmp6->icmp6_type; /* keep type for statistics */
1975         code = icmp6->icmp6_code; /* ditto. */
1976
1977         t = ip6->ip6_dst;
1978         /*
1979          * ip6_input() drops a packet if its src is multicast.
1980          * So, the src is never multicast.
1981          */
1982         ip6->ip6_dst = ip6->ip6_src;
1983
1984         /*
1985          * XXX: make sure to embed scope zone information, using
1986          * already embedded IDs or the received interface (if any).
1987          * Note that rcvif may be NULL.
1988          * TODO: scoped routing case (XXX).
1989          */
1990         bzero(&sa6_src, sizeof(sa6_src));
1991         sa6_src.sin6_family = AF_INET6;
1992         sa6_src.sin6_len = sizeof(sa6_src);
1993         sa6_src.sin6_addr = ip6->ip6_dst;
1994         in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
1995         in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
1996         bzero(&sa6_dst, sizeof(sa6_dst));
1997         sa6_dst.sin6_family = AF_INET6;
1998         sa6_dst.sin6_len = sizeof(sa6_dst);
1999         sa6_dst.sin6_addr = t;
2000         in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2001         in6_embedscope(&t, &sa6_dst, NULL, NULL);
2002
2003 #ifdef COMPAT_RFC1885
2004         /*
2005          * xxx guess MTU
2006          * RFC 1885 requires that echo reply should be truncated if it
2007          * does not fit in with (return) path MTU, but the description was
2008          * removed in the new spec.
2009          */
2010         if (icmp6_reflect_rt.ro_rt == 0 ||
2011             ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
2012                 if (icmp6_reflect_rt.ro_rt) {
2013                         RTFREE(icmp6_reflect_rt.ro_rt);
2014                         icmp6_reflect_rt.ro_rt = 0;
2015                 }
2016                 bzero(sin6, sizeof(*sin6));
2017                 sin6->sin6_family = PF_INET6;
2018                 sin6->sin6_len = sizeof(struct sockaddr_in6);
2019                 sin6->sin6_addr = ip6->ip6_dst;
2020
2021                 rtalloc_ign((struct route *)&icmp6_reflect_rt.ro_rt,
2022                             RTF_PRCLONING);
2023         }
2024
2025         if (icmp6_reflect_rt.ro_rt == 0)
2026                 goto bad;
2027
2028         if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2029             && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2030                 mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2031
2032         if (mtu < m->m_pkthdr.len) {
2033                 plen -= (m->m_pkthdr.len - mtu);
2034                 m_adj(m, mtu - m->m_pkthdr.len);
2035         }
2036 #endif
2037         /*
2038          * If the incoming packet was addressed directly to us(i.e. unicast),
2039          * use dst as the src for the reply.
2040          * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2041          * (for example) when we encounter an error while forwarding procedure
2042          * destined to a duplicated address of ours.
2043          */
2044         for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2045                 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2046                     (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2047                         src = &t;
2048                         break;
2049                 }
2050         if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2051                 /*
2052                  * This is the case if the dst is our link-local address
2053                  * and the sender is also ourselves.
2054                  */
2055                 src = &t;
2056         }
2057
2058         if (src == NULL) {
2059                 int e;
2060                 struct route_in6 ro;
2061
2062                 /*
2063                  * This case matches to multicasts, our anycast, or unicasts
2064                  * that we do not own.  Select a source address based on the
2065                  * source address of the erroneous packet.
2066                  */
2067                 bzero(&ro, sizeof(ro));
2068                 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e, NULL);
2069                 if (ro.ro_rt)
2070                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2071                 if (src == NULL) {
2072                         nd6log((LOG_DEBUG,
2073                             "icmp6_reflect: source can't be determined: "
2074                             "dst=%s, error=%d\n",
2075                             ip6_sprintf(&sa6_src.sin6_addr), e));
2076                         goto bad;
2077                 }
2078         }
2079
2080         ip6->ip6_src = *src;
2081
2082         ip6->ip6_flow = 0;
2083         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2084         ip6->ip6_vfc |= IPV6_VERSION;
2085         ip6->ip6_nxt = IPPROTO_ICMPV6;
2086         if (m->m_pkthdr.rcvif) {
2087                 /* XXX: This may not be the outgoing interface */
2088                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2089         } else
2090                 ip6->ip6_hlim = ip6_defhlim;
2091
2092         icmp6->icmp6_cksum = 0;
2093         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2094                                         sizeof(struct ip6_hdr), plen);
2095
2096         /*
2097          * XXX option handling
2098          */
2099
2100         m->m_flags &= ~(M_BCAST|M_MCAST);
2101
2102 #ifdef COMPAT_RFC1885
2103         ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL);
2104 #else
2105         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2106 #endif
2107         if (outif)
2108                 icmp6_ifoutstat_inc(outif, type, code);
2109
2110         return;
2111
2112 bad:
2113         m_freem(m);
2114         return;
2115 }
2116
2117 void
2118 icmp6_fasttimo(void)
2119 {
2120
2121         mld6_fasttimeo();
2122 }
2123
2124 static const char *
2125 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2126                     struct in6_addr *tgt6)
2127 {
2128         static char buf[1024];
2129         ksnprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2130                 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2131         return buf;
2132 }
2133
2134 void
2135 icmp6_redirect_input(struct mbuf *m, int off)
2136 {
2137         struct ifnet *ifp = m->m_pkthdr.rcvif;
2138         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2139         struct nd_redirect *nd_rd;
2140         int icmp6len = ntohs(ip6->ip6_plen);
2141         char *lladdr = NULL;
2142         int lladdrlen = 0;
2143         u_char *redirhdr = NULL;
2144         int redirhdrlen = 0;
2145         struct rtentry *rt = NULL;
2146         int is_router;
2147         int is_onlink;
2148         struct in6_addr src6 = ip6->ip6_src;
2149         struct in6_addr redtgt6;
2150         struct in6_addr reddst6;
2151         union nd_opts ndopts;
2152
2153         if (!m || !ifp)
2154                 return;
2155
2156         /* XXX if we are router, we don't update route by icmp6 redirect */
2157         if (ip6_forwarding)
2158                 goto freeit;
2159         if (!icmp6_rediraccept)
2160                 goto freeit;
2161
2162 #ifndef PULLDOWN_TEST
2163         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2164         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2165 #else
2166         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2167         if (nd_rd == NULL) {
2168                 icmp6stat.icp6s_tooshort++;
2169                 return;
2170         }
2171 #endif
2172         redtgt6 = nd_rd->nd_rd_target;
2173         reddst6 = nd_rd->nd_rd_dst;
2174
2175         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2176                 redtgt6.s6_addr16[1] = htons(ifp->if_index);
2177         if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2178                 reddst6.s6_addr16[1] = htons(ifp->if_index);
2179
2180         /* validation */
2181         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2182                 nd6log((LOG_ERR,
2183                         "ICMP6 redirect sent from %s rejected; "
2184                         "must be from linklocal\n", ip6_sprintf(&src6)));
2185                 goto bad;
2186         }
2187         if (ip6->ip6_hlim != 255) {
2188                 nd6log((LOG_ERR,
2189                         "ICMP6 redirect sent from %s rejected; "
2190                         "hlim=%d (must be 255)\n",
2191                         ip6_sprintf(&src6), ip6->ip6_hlim));
2192                 goto bad;
2193         }
2194     {
2195         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2196         struct sockaddr_in6 sin6;
2197         struct in6_addr *gw6;
2198
2199         bzero(&sin6, sizeof(sin6));
2200         sin6.sin6_family = AF_INET6;
2201         sin6.sin6_len = sizeof(struct sockaddr_in6);
2202         bcopy(&reddst6, &sin6.sin6_addr, sizeof reddst6);
2203         rt = rtpurelookup((struct sockaddr *)&sin6);
2204         if (rt != NULL) {
2205                 if (rt->rt_gateway == NULL ||
2206                     rt->rt_gateway->sa_family != AF_INET6) {
2207                         nd6log((LOG_ERR,
2208                             "ICMP6 redirect rejected; no route "
2209                             "with inet6 gateway found for redirect dst: %s\n",
2210                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2211                         --rt->rt_refcnt;
2212                         goto bad;
2213                 }
2214
2215                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2216                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2217                         nd6log((LOG_ERR,
2218                                 "ICMP6 redirect rejected; "
2219                                 "not equal to gw-for-src=%s (must be same): "
2220                                 "%s\n",
2221                                 ip6_sprintf(gw6),
2222                                 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2223                         --rt->rt_refcnt;
2224                         goto bad;
2225                 }
2226         } else {
2227                 nd6log((LOG_ERR,
2228                         "ICMP6 redirect rejected; "
2229                         "no route found for redirect dst: %s\n",
2230                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2231                 goto bad;
2232         }
2233         --rt->rt_refcnt;
2234         rt = NULL;
2235     }
2236         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2237                 nd6log((LOG_ERR,
2238                         "ICMP6 redirect rejected; "
2239                         "redirect dst must be unicast: %s\n",
2240                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2241                 goto bad;
2242         }
2243
2244         is_router = is_onlink = 0;
2245         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2246                 is_router = 1;  /* router case */
2247         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2248                 is_onlink = 1;  /* on-link destination case */
2249         if (!is_router && !is_onlink) {
2250                 nd6log((LOG_ERR,
2251                         "ICMP6 redirect rejected; "
2252                         "neither router case nor onlink case: %s\n",
2253                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2254                 goto bad;
2255         }
2256         /* validation passed */
2257
2258         icmp6len -= sizeof(*nd_rd);
2259         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2260         if (nd6_options(&ndopts) < 0) {
2261                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2262                         "invalid ND option, rejected: %s\n",
2263                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2264                 /* nd6_options have incremented stats */
2265                 goto freeit;
2266         }
2267
2268         if (ndopts.nd_opts_tgt_lladdr) {
2269                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2270                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2271         }
2272
2273         if (ndopts.nd_opts_rh) {
2274                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2275                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2276         }
2277
2278         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2279                 nd6log((LOG_INFO,
2280                         "icmp6_redirect_input: lladdrlen mismatch for %s "
2281                         "(if %d, icmp6 packet %d): %s\n",
2282                         ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2283                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2284                 goto bad;
2285         }
2286
2287         /* RFC 2461 8.3 */
2288         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2289                          is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2290
2291         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2292                 /* perform rtredirect */
2293                 struct sockaddr_in6 sdst;
2294                 struct sockaddr_in6 sgw;
2295                 struct sockaddr_in6 ssrc;
2296
2297                 bzero(&sdst, sizeof(sdst));
2298                 bzero(&sgw, sizeof(sgw));
2299                 bzero(&ssrc, sizeof(ssrc));
2300                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2301                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2302                         sizeof(struct sockaddr_in6);
2303                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2304                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2305                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2306                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2307                            NULL, RTF_GATEWAY | RTF_HOST,
2308                            (struct sockaddr *)&ssrc);
2309         }
2310         /* finally update cached route in each socket via kpfctlinput */
2311     {
2312         struct sockaddr_in6 sdst;
2313
2314         bzero(&sdst, sizeof(sdst));
2315         sdst.sin6_family = AF_INET6;
2316         sdst.sin6_len = sizeof(struct sockaddr_in6);
2317         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2318         kpfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2319 #ifdef IPSEC
2320         key_sa_routechange((struct sockaddr *)&sdst);
2321 #endif
2322     }
2323
2324 freeit:
2325         m_freem(m);
2326         return;
2327
2328 bad:
2329         icmp6stat.icp6s_badredirect++;
2330         m_freem(m);
2331 }
2332
2333 void
2334 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2335 {
2336         struct ifnet *ifp;      /* my outgoing interface */
2337         struct in6_addr *ifp_ll6;
2338         struct in6_addr *router_ll6;
2339         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2340         struct mbuf *m = NULL;  /* newly allocated one */
2341         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2342         struct nd_redirect *nd_rd;
2343         size_t maxlen;
2344         u_char *p;
2345         struct ifnet *outif = NULL;
2346         struct sockaddr_in6 src_sa;
2347
2348         icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2349
2350         /* if we are not router, we don't send icmp6 redirect */
2351         if (!ip6_forwarding || ip6_accept_rtadv)
2352                 goto fail;
2353
2354         /* sanity check */
2355         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2356                 goto fail;
2357
2358         /*
2359          * Address check:
2360          *  the source address must identify a neighbor, and
2361          *  the destination address must not be a multicast address
2362          *  [RFC 2461, sec 8.2]
2363          */
2364         sip6 = mtod(m0, struct ip6_hdr *);
2365         bzero(&src_sa, sizeof(src_sa));
2366         src_sa.sin6_family = AF_INET6;
2367         src_sa.sin6_len = sizeof(src_sa);
2368         src_sa.sin6_addr = sip6->ip6_src;
2369         /* we don't currently use sin6_scope_id, but eventually use it */
2370         src_sa.sin6_scope_id = in6_addr2scopeid(ifp, &sip6->ip6_src);
2371         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2372                 goto fail;
2373         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2374                 goto fail;      /* what should we do here? */
2375
2376         /* rate limit */
2377         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2378                 goto fail;
2379
2380         /*
2381          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2382          * we almost always ask for an mbuf cluster for simplicity.
2383          * (MHLEN < IPV6_MMTU is almost always true)
2384          */
2385 #if IPV6_MMTU >= MCLBYTES
2386 # error assumption failed about IPV6_MMTU and MCLBYTES
2387 #endif
2388         m = m_getb(IPV6_MMTU, MB_DONTWAIT, MT_HEADER, M_PKTHDR);
2389         if (!m)
2390                 goto fail;
2391         m->m_len = 0;
2392         maxlen = M_TRAILINGSPACE(m);
2393         maxlen = min(IPV6_MMTU, maxlen);
2394         /* just for safety */
2395         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2396             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2397                 goto fail;
2398         }
2399
2400         {
2401                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2402                 struct in6_ifaddr *ia;
2403                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2404                                                  IN6_IFF_NOTREADY|
2405                                                  IN6_IFF_ANYCAST)) == NULL)
2406                         goto fail;
2407                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2408         }
2409
2410         /* get ip6 linklocal address for the router. */
2411         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2412                 struct sockaddr_in6 *sin6;
2413                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2414                 router_ll6 = &sin6->sin6_addr;
2415                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2416                         router_ll6 = NULL;
2417         } else
2418                 router_ll6 = NULL;
2419
2420         /* ip6 */
2421         ip6 = mtod(m, struct ip6_hdr *);
2422         ip6->ip6_flow = 0;
2423         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2424         ip6->ip6_vfc |= IPV6_VERSION;
2425         /* ip6->ip6_plen will be set later */
2426         ip6->ip6_nxt = IPPROTO_ICMPV6;
2427         ip6->ip6_hlim = 255;
2428         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2429         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2430         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2431
2432         /* ND Redirect */
2433         nd_rd = (struct nd_redirect *)(ip6 + 1);
2434         nd_rd->nd_rd_type = ND_REDIRECT;
2435         nd_rd->nd_rd_code = 0;
2436         nd_rd->nd_rd_reserved = 0;
2437         if (rt->rt_flags & RTF_GATEWAY) {
2438                 /*
2439                  * nd_rd->nd_rd_target must be a link-local address in
2440                  * better router cases.
2441                  */
2442                 if (!router_ll6)
2443                         goto fail;
2444                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2445                       sizeof(nd_rd->nd_rd_target));
2446                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2447                       sizeof(nd_rd->nd_rd_dst));
2448         } else {
2449                 /* make sure redtgt == reddst */
2450                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2451                       sizeof(nd_rd->nd_rd_target));
2452                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2453                       sizeof(nd_rd->nd_rd_dst));
2454         }
2455
2456         p = (u_char *)(nd_rd + 1);
2457
2458         if (!router_ll6)
2459                 goto nolladdropt;
2460
2461     {
2462         /* target lladdr option */
2463         struct rtentry *rt_router = NULL;
2464         int len;
2465         struct sockaddr_dl *sdl;
2466         struct nd_opt_hdr *nd_opt;
2467         char *lladdr;
2468
2469         rt_router = nd6_lookup(router_ll6, 0, ifp);
2470         if (!rt_router)
2471                 goto nolladdropt;
2472         len = sizeof(*nd_opt) + ifp->if_addrlen;
2473         len = (len + 7) & ~7;   /* round by 8 */
2474         /* safety check */
2475         if (len + (p - (u_char *)ip6) > maxlen)
2476                 goto nolladdropt;
2477         if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2478             (rt_router->rt_flags & RTF_LLINFO) &&
2479             (rt_router->rt_gateway->sa_family == AF_LINK) &&
2480             (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2481             sdl->sdl_alen) {
2482                 nd_opt = (struct nd_opt_hdr *)p;
2483                 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2484                 nd_opt->nd_opt_len = len >> 3;
2485                 lladdr = (char *)(nd_opt + 1);
2486                 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2487                 p += len;
2488         }
2489     }
2490 nolladdropt:;
2491
2492         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2493
2494         /* just to be safe */
2495 #ifdef M_DECRYPTED      /*not openbsd*/
2496         if (m0->m_flags & M_DECRYPTED)
2497                 goto noredhdropt;
2498 #endif
2499         if (p - (u_char *)ip6 > maxlen)
2500                 goto noredhdropt;
2501
2502     {
2503         /* redirected header option */
2504         int len;
2505         struct nd_opt_rd_hdr *nd_opt_rh;
2506
2507         /*
2508          * compute the maximum size for icmp6 redirect header option.
2509          * XXX room for auth header?
2510          */
2511         len = maxlen - (p - (u_char *)ip6);
2512         len &= ~7;
2513
2514         /* This is just for simplicity. */
2515         if (m0->m_pkthdr.len != m0->m_len) {
2516                 if (m0->m_next) {
2517                         m_freem(m0->m_next);
2518                         m0->m_next = NULL;
2519                 }
2520                 m0->m_pkthdr.len = m0->m_len;
2521         }
2522
2523         /*
2524          * Redirected header option spec (RFC2461 4.6.3) talks nothing
2525          * about padding/truncate rule for the original IP packet.
2526          * From the discussion on IPv6imp in Feb 1999, the consensus was:
2527          * - "attach as much as possible" is the goal
2528          * - pad if not aligned (original size can be guessed by original
2529          *   ip6 header)
2530          * Following code adds the padding if it is simple enough,
2531          * and truncates if not.
2532          */
2533         if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2534                 panic("assumption failed in %s:%d", __FILE__, __LINE__);
2535
2536         if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2537                 /* not enough room, truncate */
2538                 m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2539         } else {
2540                 /* enough room, pad or truncate */
2541                 size_t extra;
2542
2543                 extra = m0->m_pkthdr.len % 8;
2544                 if (extra) {
2545                         /* pad if easy enough, truncate if not */
2546                         if (8 - extra <= M_TRAILINGSPACE(m0)) {
2547                                 /* pad */
2548                                 m0->m_len += (8 - extra);
2549                                 m0->m_pkthdr.len += (8 - extra);
2550                         } else {
2551                                 /* truncate */
2552                                 m0->m_pkthdr.len -= extra;
2553                                 m0->m_len -= extra;
2554                         }
2555                 }
2556                 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2557                 m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2558         }
2559
2560         nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2561         bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2562         nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2563         nd_opt_rh->nd_opt_rh_len = len >> 3;
2564         p += sizeof(*nd_opt_rh);
2565         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2566
2567         /* connect m0 to m */
2568         m->m_next = m0;
2569         m->m_pkthdr.len = m->m_len + m0->m_len;
2570     }
2571 noredhdropt:;
2572
2573         if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
2574                 sip6->ip6_src.s6_addr16[1] = 0;
2575         if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
2576                 sip6->ip6_dst.s6_addr16[1] = 0;
2577 #if 0
2578         if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
2579                 ip6->ip6_src.s6_addr16[1] = 0;
2580         if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2581                 ip6->ip6_dst.s6_addr16[1] = 0;
2582 #endif
2583         if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
2584                 nd_rd->nd_rd_target.s6_addr16[1] = 0;
2585         if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
2586                 nd_rd->nd_rd_dst.s6_addr16[1] = 0;
2587
2588         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2589
2590         nd_rd->nd_rd_cksum = 0;
2591         nd_rd->nd_rd_cksum
2592                 = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2593
2594         /* send the packet to outside... */
2595         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2596         if (outif) {
2597                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2598                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2599         }
2600         icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2601
2602         return;
2603
2604 fail:
2605         if (m)
2606                 m_freem(m);
2607         if (m0)
2608                 m_freem(m0);
2609 }
2610
2611 #ifdef HAVE_NRL_INPCB
2612 #define in6pcb          inpcb
2613 #define in6p_icmp6filt  inp_icmp6filt
2614 #endif
2615 /*
2616  * ICMPv6 socket option processing.
2617  */
2618 void
2619 icmp6_ctloutput(netmsg_t msg)
2620 {
2621         struct socket *so = msg->ctloutput.base.nm_so;
2622         struct sockopt *sopt = msg->ctloutput.nm_sopt;
2623         int error = 0;
2624         int optlen;
2625         struct inpcb *inp = so->so_pcb;
2626         int level, op, optname;
2627
2628         if (sopt) {
2629                 level = sopt->sopt_level;
2630                 op = sopt->sopt_dir;
2631                 optname = sopt->sopt_name;
2632                 optlen = sopt->sopt_valsize;
2633         } else
2634                 level = op = optname = optlen = 0;
2635
2636         if (level != IPPROTO_ICMPV6) {
2637                 error = EINVAL;
2638                 goto out;
2639         }
2640
2641         switch (op) {
2642         case PRCO_SETOPT:
2643                 switch (optname) {
2644                 case ICMP6_FILTER:
2645                     {
2646                         if (optlen != sizeof(struct icmp6_filter)) {
2647                                 error = EMSGSIZE;
2648                                 break;
2649                         }
2650                         if (inp->in6p_icmp6filt == NULL) {
2651                                 error = EINVAL;
2652                                 break;
2653                         }
2654                         error = soopt_to_kbuf(sopt, inp->in6p_icmp6filt, optlen,
2655                                 optlen);
2656                         break;
2657                     }
2658
2659                 default:
2660                         error = ENOPROTOOPT;
2661                         break;
2662                 }
2663                 break;
2664
2665         case PRCO_GETOPT:
2666                 switch (optname) {
2667                 case ICMP6_FILTER:
2668                     {
2669                         if (inp->in6p_icmp6filt == NULL) {
2670                                 error = EINVAL;
2671                                 break;
2672                         }
2673                         soopt_from_kbuf(sopt, inp->in6p_icmp6filt,
2674                                 sizeof(struct icmp6_filter));
2675                         break;
2676                     }
2677
2678                 default:
2679                         error = ENOPROTOOPT;
2680                         break;
2681                 }
2682                 break;
2683         }
2684 out:
2685         lwkt_replymsg(&msg->ctloutput.base.lmsg, error);
2686 }
2687 #ifdef HAVE_NRL_INPCB
2688 #undef in6pcb
2689 #undef in6p_icmp6filt
2690 #endif
2691
2692 #ifndef HAVE_PPSRATECHECK
2693 #ifndef timersub
2694 #define timersub(tvp, uvp, vvp)                                         \
2695         do {                                                            \
2696                 (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;          \
2697                 (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;       \
2698                 if ((vvp)->tv_usec < 0) {                               \
2699                         (vvp)->tv_sec--;                                \
2700                         (vvp)->tv_usec += 1000000;                      \
2701                 }                                                       \
2702         } while (0)
2703 #endif
2704
2705 /*
2706  * ppsratecheck(): packets (or events) per second limitation.
2707  */
2708 static int
2709 ppsratecheck(struct timeval *lasttime, int *curpps,
2710              int maxpps)        /* maximum pps allowed */
2711 {
2712         struct timeval tv, delta;
2713         int rv;
2714
2715         microtime(&tv);
2716
2717         timersub(&tv, lasttime, &delta);
2718
2719         /*
2720          * Check for 0,0 so that the message will be seen at least once.
2721          * If more than one second has passed since the last update of
2722          * lasttime, reset the counter.
2723          *
2724          * We do increment *curpps even in *curpps < maxpps case, as some may
2725          * try to use *curpps for stat purposes as well.
2726          */
2727         if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
2728             delta.tv_sec >= 1) {
2729                 *lasttime = tv;
2730                 *curpps = 0;
2731                 rv = 1;
2732         } else if (maxpps < 0)
2733                 rv = 1;
2734         else if (*curpps < maxpps)
2735                 rv = 1;
2736         else
2737                 rv = 0;
2738
2739 #if 1 /* DIAGNOSTIC? */
2740         /* be careful about wrap-around */
2741         if (*curpps + 1 > *curpps)
2742                 *curpps = *curpps + 1;
2743 #else
2744         /*
2745          * assume that there's not too many calls to this function.
2746          * not sure if the assumption holds, as it depends on *caller's*
2747          * behavior, not the behavior of this function.
2748          * IMHO it is wrong to make assumption on the caller's behavior,
2749          * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
2750          */
2751         *curpps = *curpps + 1;
2752 #endif
2753
2754         return (rv);
2755 }
2756 #endif
2757
2758 /*
2759  * Perform rate limit check.
2760  * Returns 0 if it is okay to send the icmp6 packet.
2761  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2762  * limitation.
2763  *
2764  * XXX per-destination/type check necessary?
2765  */
2766 static int
2767 icmp6_ratelimit(const struct in6_addr *dst,     /* not used at this moment */
2768                 const int type,                 /* not used at this moment */
2769                 const int code)                 /* not used at this moment */
2770 {
2771         int ret;
2772
2773         ret = 0;        /* okay to send */
2774
2775         /* PPS limit */
2776         if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2777             icmp6errppslim)) {
2778                 /* The packet is subject to rate limit */
2779                 ret++;
2780         }
2781
2782         return ret;
2783 }