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 /*      $DragonFly: src/sys/netinet6/icmp6.c,v 1.14 2004/12/21 02:54:47 hsu Exp $       */
   3 /*      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $ */
   4
   5 /*
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 1982, 1986, 1988, 1993
  36  *      The Regents of the University of California.  All rights reserved.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *      This product includes software developed by the University of
  49  *      California, Berkeley and its contributors.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  67  */
  68
  69 #include "opt_inet.h"
  70 #include "opt_inet6.h"
  71 #include "opt_ipsec.h"
  72
  73 #include <sys/param.h>
  74 #include <sys/systm.h>
  75 #include <sys/malloc.h>
  76 #include <sys/mbuf.h>
  77 #include <sys/protosw.h>
  78 #include <sys/socket.h>
  79 #include <sys/socketvar.h>
  80 #include <sys/time.h>
  81 #include <sys/kernel.h>
  82 #include <sys/syslog.h>
  83 #include <sys/domain.h>
  84
  85 #include <net/if.h>
  86 #include <net/route.h>
  87 #include <net/if_dl.h>
  88 #include <net/if_types.h>
  89
  90 #include <netinet/in.h>
  91 #include <netinet/in_var.h>
  92 #include <netinet/ip6.h>
  93 #include <netinet6/ip6_var.h>
  94 #include <netinet/icmp6.h>
  95 #include <netinet6/mld6_var.h>
  96 #include <netinet/in_pcb.h>
  97 #include <netinet6/in6_pcb.h>
  98 #include <netinet6/nd6.h>
  99 #include <netinet6/in6_ifattach.h>
 100 #include <netinet6/ip6protosw.h>
 101
 102 #ifdef IPSEC
 103 #include <netinet6/ipsec.h>
 104 #include <netproto/key/key.h>
 105 #endif
 106
 107 #ifdef FAST_IPSEC
 108 #include <netproto/ipsec/ipsec.h>
 109 #include <netproto/ipsec/key.h>
 110 #define IPSEC
 111 #endif
 112
 113 #include <net/net_osdep.h>
 114
 115 #ifdef HAVE_NRL_INPCB
 116 /* inpcb members */
 117 #define in6pcb          inpcb
 118 #define in6p_laddr      inp_laddr6
 119 #define in6p_faddr      inp_faddr6
 120 #define in6p_icmp6filt  inp_icmp6filt
 121 #define in6p_route      inp_route
 122 #define in6p_socket     inp_socket
 123 #define in6p_flags      inp_flags
 124 #define in6p_moptions   inp_moptions6
 125 #define in6p_outputopts inp_outputopts6
 126 #define in6p_ip6        inp_ipv6
 127 #define in6p_flowinfo   inp_flowinfo
 128 #define in6p_sp         inp_sp
 129 #define in6p_next       inp_next
 130 #define in6p_prev       inp_prev
 131 /* macro names */
 132 #define sotoin6pcb      sotoinpcb
 133 /* function names */
 134 #define in6_pcbdetach   in_pcbdetach
 135 #define in6_rtchange    in_rtchange
 136
 137 /*
 138  * for KAME src sync over BSD*'s. XXX: FreeBSD (>=3) are VERY different from
 139  * others...
 140  */
 141 #define in6p_ip6_nxt    inp_ipv6.ip6_nxt
 142 #endif
 143
 144 /*
 145  * ppratecheck() is available, so define it here.
 146  */
 147 #define HAVE_PPSRATECHECK
 148
 149 extern struct domain inet6domain;
 150 extern struct ip6protosw inet6sw[];
 151 extern u_char ip6_protox[];
 152
 153 struct icmp6stat icmp6stat;
 154
 155 extern struct inpcbinfo ripcbinfo;
 156 extern int icmp6errppslim;
 157 static int icmp6errpps_count = 0;
 158 static struct timeval icmp6errppslim_last;
 159 extern int icmp6_nodeinfo;
 160
 161 static void icmp6_errcount (struct icmp6errstat *, int, int);
 162 static int icmp6_rip6_input (struct mbuf **, int);
 163 static int icmp6_ratelimit (const struct in6_addr *, const int, const int);
 164 static const char *icmp6_redirect_diag (struct in6_addr *,
 165         struct in6_addr *, struct in6_addr *);
 166 #ifndef HAVE_PPSRATECHECK
 167 static int ppsratecheck (struct timeval *, int *, int);
 168 #endif
 169 static struct mbuf *ni6_input (struct mbuf *, int);
 170 static struct mbuf *ni6_nametodns (const char *, int, int);
 171 static int ni6_dnsmatch (const char *, int, const char *, int);
 172 static int ni6_addrs (struct icmp6_nodeinfo *, struct mbuf *,
 173                           struct ifnet **, char *);
 174 static int ni6_store_addrs (struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 175                                 struct ifnet *, int);
 176 static int icmp6_notify_error (struct mbuf *, int, int, int);
 177
 178 #ifdef COMPAT_RFC1885
 179 static struct route_in6 icmp6_reflect_rt;
 180 #endif
 181
 182
 183 void
 184 icmp6_init(void)
 185 {
 186         mld6_init();
 187 }
 188
 189 static void
 190 icmp6_errcount(struct icmp6errstat *stat, int type, int code)
 191 {
 192         switch (type) {
 193         case ICMP6_DST_UNREACH:
 194                 switch (code) {
 195                 case ICMP6_DST_UNREACH_NOROUTE:
 196                         stat->icp6errs_dst_unreach_noroute++;
 197                         return;
 198                 case ICMP6_DST_UNREACH_ADMIN:
 199                         stat->icp6errs_dst_unreach_admin++;
 200                         return;
 201                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 202                         stat->icp6errs_dst_unreach_beyondscope++;
 203                         return;
 204                 case ICMP6_DST_UNREACH_ADDR:
 205                         stat->icp6errs_dst_unreach_addr++;
 206                         return;
 207                 case ICMP6_DST_UNREACH_NOPORT:
 208                         stat->icp6errs_dst_unreach_noport++;
 209                         return;
 210                 }
 211                 break;
 212         case ICMP6_PACKET_TOO_BIG:
 213                 stat->icp6errs_packet_too_big++;
 214                 return;
 215         case ICMP6_TIME_EXCEEDED:
 216                 switch (code) {
 217                 case ICMP6_TIME_EXCEED_TRANSIT:
 218                         stat->icp6errs_time_exceed_transit++;
 219                         return;
 220                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 221                         stat->icp6errs_time_exceed_reassembly++;
 222                         return;
 223                 }
 224                 break;
 225         case ICMP6_PARAM_PROB:
 226                 switch (code) {
 227                 case ICMP6_PARAMPROB_HEADER:
 228                         stat->icp6errs_paramprob_header++;
 229                         return;
 230                 case ICMP6_PARAMPROB_NEXTHEADER:
 231                         stat->icp6errs_paramprob_nextheader++;
 232                         return;
 233                 case ICMP6_PARAMPROB_OPTION:
 234                         stat->icp6errs_paramprob_option++;
 235                         return;
 236                 }
 237                 break;
 238         case ND_REDIRECT:
 239                 stat->icp6errs_redirect++;
 240                 return;
 241         }
 242         stat->icp6errs_unknown++;
 243 }
 244
 245 /*
 246  * Generate an error packet of type error in response to bad IP6 packet.
 247  */
 248 void
 249 icmp6_error(struct mbuf *m, int type, int code, int param)
 250 {
 251         struct ip6_hdr *oip6, *nip6;
 252         struct icmp6_hdr *icmp6;
 253         u_int preplen;
 254         int off;
 255         int nxt;
 256
 257         icmp6stat.icp6s_error++;
 258
 259         /* count per-type-code statistics */
 260         icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
 261
 262 #ifdef M_DECRYPTED      /*not openbsd*/
 263         if (m->m_flags & M_DECRYPTED) {
 264                 icmp6stat.icp6s_canterror++;
 265                 goto freeit;
 266         }
 267 #endif
 268
 269 #ifndef PULLDOWN_TEST
 270         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 271 #else
 272         if (m->m_len < sizeof(struct ip6_hdr)) {
 273                 m = m_pullup(m, sizeof(struct ip6_hdr));
 274                 if (m == NULL)
 275                         return;
 276         }
 277 #endif
 278         oip6 = mtod(m, struct ip6_hdr *);
 279
 280         /*
 281          * Multicast destination check. For unrecognized option errors,
 282          * this check has already done in ip6_unknown_opt(), so we can
 283          * check only for other errors.
 284          */
 285         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 286              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 287             (type != ICMP6_PACKET_TOO_BIG &&
 288              (type != ICMP6_PARAM_PROB ||
 289               code != ICMP6_PARAMPROB_OPTION)))
 290                 goto freeit;
 291
 292         /* Source address check. XXX: the case of anycast source? */
 293         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 294             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 295                 goto freeit;
 296
 297         /*
 298          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 299          * don't do it.
 300          */
 301         nxt = -1;
 302         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 303         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 304                 struct icmp6_hdr *icp;
 305
 306 #ifndef PULLDOWN_TEST
 307                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 308                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 309 #else
 310                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 311                         sizeof(*icp));
 312                 if (icp == NULL) {
 313                         icmp6stat.icp6s_tooshort++;
 314                         return;
 315                 }
 316 #endif
 317                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 318                     icp->icmp6_type == ND_REDIRECT) {
 319                         /*
 320                          * ICMPv6 error
 321                          * Special case: for redirect (which is
 322                          * informational) we must not send icmp6 error.
 323                          */
 324                         icmp6stat.icp6s_canterror++;
 325                         goto freeit;
 326                 } else {
 327                         /* ICMPv6 informational - send the error */
 328                 }
 329         } else {
 330                 /* non-ICMPv6 - send the error */
 331         }
 332
 333         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 334
 335         /* Finally, do rate limitation check. */
 336         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 337                 icmp6stat.icp6s_toofreq++;
 338                 goto freeit;
 339         }
 340
 341         /*
 342          * OK, ICMP6 can be generated.
 343          */
 344
 345         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 346                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 347
 348         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 349         M_PREPEND(m, preplen, MB_DONTWAIT);
 350         if (m && m->m_len < preplen)
 351                 m = m_pullup(m, preplen);
 352         if (m == NULL) {
 353                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 354                 return;
 355         }
 356
 357         nip6 = mtod(m, struct ip6_hdr *);
 358         nip6->ip6_src  = oip6->ip6_src;
 359         nip6->ip6_dst  = oip6->ip6_dst;
 360
 361         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
 362                 oip6->ip6_src.s6_addr16[1] = 0;
 363         if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
 364                 oip6->ip6_dst.s6_addr16[1] = 0;
 365
 366         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 367         icmp6->icmp6_type = type;
 368         icmp6->icmp6_code = code;
 369         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 370
 371         /*
 372          * icmp6_reflect() is designed to be in the input path.
 373          * icmp6_error() can be called from both input and outut path,
 374          * and if we are in output path rcvif could contain bogus value.
 375          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 376          * information in ip header (nip6).
 377          */
 378         m->m_pkthdr.rcvif = NULL;
 379
 380         icmp6stat.icp6s_outhist[type]++;
 381         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 382
 383         return;
 384
 385   freeit:
 386         /*
 387          * If we can't tell wheter or not we can generate ICMP6, free it.
 388          */
 389         m_freem(m);
 390 }
 391
 392 /*
 393  * Process a received ICMP6 message.
 394  */
 395 int
 396 icmp6_input(struct mbuf **mp, int *offp, int proto)
 397 {
 398         struct mbuf *m = *mp, *n;
 399         struct ip6_hdr *ip6, *nip6;
 400         struct icmp6_hdr *icmp6, *nicmp6;
 401         int off = *offp;
 402         int icmp6len = m->m_pkthdr.len - *offp;
 403         int code, sum, noff;
 404
 405 #ifndef PULLDOWN_TEST
 406         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 407         /* m might change if M_LOOP.  So, call mtod after this */
 408 #endif
 409
 410         /*
 411          * Locate icmp6 structure in mbuf, and check
 412          * that not corrupted and of at least minimum length
 413          */
 414
 415         ip6 = mtod(m, struct ip6_hdr *);
 416         if (icmp6len < sizeof(struct icmp6_hdr)) {
 417                 icmp6stat.icp6s_tooshort++;
 418                 goto freeit;
 419         }
 420
 421         /*
 422          * calculate the checksum
 423          */
 424 #ifndef PULLDOWN_TEST
 425         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 426 #else
 427         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 428         if (icmp6 == NULL) {
 429                 icmp6stat.icp6s_tooshort++;
 430                 return IPPROTO_DONE;
 431         }
 432 #endif
 433         code = icmp6->icmp6_code;
 434
 435         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 436                 nd6log((LOG_ERR,
 437                     "ICMP6 checksum error(%d|%x) %s\n",
 438                     icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
 439                 icmp6stat.icp6s_checksum++;
 440                 goto freeit;
 441         }
 442
 443         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 444                 /*
 445                  * Deliver very specific ICMP6 type only.
 446                  * This is important to deilver TOOBIG.  Otherwise PMTUD
 447                  * will not work.
 448                  */
 449                 switch (icmp6->icmp6_type) {
 450                 case ICMP6_DST_UNREACH:
 451                 case ICMP6_PACKET_TOO_BIG:
 452                 case ICMP6_TIME_EXCEEDED:
 453                         break;
 454                 default:
 455                         goto freeit;
 456                 }
 457         }
 458
 459         icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
 460         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
 461         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 462                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
 463
 464         switch (icmp6->icmp6_type) {
 465         case ICMP6_DST_UNREACH:
 466                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
 467                 switch (code) {
 468                 case ICMP6_DST_UNREACH_NOROUTE:
 469                         code = PRC_UNREACH_NET;
 470                         break;
 471                 case ICMP6_DST_UNREACH_ADMIN:
 472                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
 473                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 474                         break;
 475                 case ICMP6_DST_UNREACH_ADDR:
 476                         code = PRC_HOSTDEAD;
 477                         break;
 478 #ifdef COMPAT_RFC1885
 479                 case ICMP6_DST_UNREACH_NOTNEIGHBOR:
 480                         code = PRC_UNREACH_SRCFAIL;
 481                         break;
 482 #else
 483                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 484                         /* I mean "source address was incorrect." */
 485                         code = PRC_PARAMPROB;
 486                         break;
 487 #endif
 488                 case ICMP6_DST_UNREACH_NOPORT:
 489                         code = PRC_UNREACH_PORT;
 490                         break;
 491                 default:
 492                         goto badcode;
 493                 }
 494                 goto deliver;
 495                 break;
 496
 497         case ICMP6_PACKET_TOO_BIG:
 498                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
 499                 if (code != 0)
 500                         goto badcode;
 501
 502                 code = PRC_MSGSIZE;
 503
 504                 /*
 505                  * Updating the path MTU will be done after examining
 506                  * intermediate extension headers.
 507                  */
 508                 goto deliver;
 509                 break;
 510
 511         case ICMP6_TIME_EXCEEDED:
 512                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
 513                 switch (code) {
 514                 case ICMP6_TIME_EXCEED_TRANSIT:
 515                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 516                         code += PRC_TIMXCEED_INTRANS;
 517                         break;
 518                 default:
 519                         goto badcode;
 520                 }
 521                 goto deliver;
 522                 break;
 523
 524         case ICMP6_PARAM_PROB:
 525                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
 526                 switch (code) {
 527                 case ICMP6_PARAMPROB_NEXTHEADER:
 528                         code = PRC_UNREACH_PROTOCOL;
 529                         break;
 530                 case ICMP6_PARAMPROB_HEADER:
 531                 case ICMP6_PARAMPROB_OPTION:
 532                         code = PRC_PARAMPROB;
 533                         break;
 534                 default:
 535                         goto badcode;
 536                 }
 537                 goto deliver;
 538                 break;
 539
 540         case ICMP6_ECHO_REQUEST:
 541                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
 542                 if (code != 0)
 543                         goto badcode;
 544                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 545                         /* Give up remote */
 546                         break;
 547                 }
 548                 if ((n->m_flags & M_EXT) != 0
 549                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 550                         struct mbuf *n0 = n;
 551                         const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
 552                         int n0len;
 553
 554                         /*
 555                          * Prepare an internal mbuf. m_pullup() doesn't
 556                          * always copy the length we specified.
 557                          */
 558                         if (maxlen >= MCLBYTES) {
 559                                 /* Give up remote */
 560                                 m_freem(n0);
 561                                 break;
 562                         }
 563                         MGETHDR(n, MB_DONTWAIT, n0->m_type);
 564                         n0len = n0->m_pkthdr.len;       /* save for use below */
 565                         if (n)
 566                                 M_MOVE_PKTHDR(n, n0);
 567                         if (n && maxlen >= MHLEN) {
 568                                 MCLGET(n, MB_DONTWAIT);
 569                                 if ((n->m_flags & M_EXT) == 0) {
 570                                         m_free(n);
 571                                         n = NULL;
 572                                 }
 573                         }
 574                         if (n == NULL) {
 575                                 /* Give up remote */
 576                                 m_freem(n0);
 577                                 break;
 578                         }
 579                         /*
 580                          * Copy IPv6 and ICMPv6 only.
 581                          */
 582                         nip6 = mtod(n, struct ip6_hdr *);
 583                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 584                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 585                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 586                         noff = sizeof(struct ip6_hdr);
 587                         /* new mbuf contains only ipv6+icmpv6 headers */
 588                         n->m_len = noff + sizeof(struct icmp6_hdr);
 589                         /*
 590                          * Adjust mbuf. ip6_plen will be adjusted in
 591                          * ip6_output().
 592                          */
 593                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 594                         /* recalculate complete packet size */
 595                         n->m_pkthdr.len = n0len + (noff - off);
 596                         n->m_next = n0;
 597                 } else {
 598                         nip6 = mtod(n, struct ip6_hdr *);
 599                         nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
 600                         noff = off;
 601                 }
 602                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 603                 nicmp6->icmp6_code = 0;
 604                 if (n) {
 605                         icmp6stat.icp6s_reflect++;
 606                         icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
 607                         icmp6_reflect(n, noff);
 608                 }
 609                 break;
 610
 611         case ICMP6_ECHO_REPLY:
 612                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
 613                 if (code != 0)
 614                         goto badcode;
 615                 break;
 616
 617         case MLD_LISTENER_QUERY:
 618         case MLD_LISTENER_REPORT:
 619                 if (icmp6len < sizeof(struct mld_hdr))
 620                         goto badlen;
 621                 if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
 622                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
 623                 else
 624                         icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
 625                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 626                         /* give up local */
 627                         mld6_input(m, off);
 628                         m = NULL;
 629                         goto freeit;
 630                 }
 631                 mld6_input(n, off);
 632                 /* m stays. */
 633                 break;
 634
 635         case MLD_LISTENER_DONE:
 636                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
 637                 if (icmp6len < sizeof(struct mld_hdr))  /* necessary? */
 638                         goto badlen;
 639                 break;          /* nothing to be done in kernel */
 640
 641         case MLD_MTRACE_RESP:
 642         case MLD_MTRACE:
 643                 /* XXX: these two are experimental.  not officially defind. */
 644                 /* XXX: per-interface statistics? */
 645                 break;          /* just pass it to applications */
 646
 647         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 648             {
 649                 enum { WRU, FQDN } mode;
 650
 651                 if (!icmp6_nodeinfo)
 652                         break;
 653
 654                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 655                         mode = WRU;
 656                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 657                         mode = FQDN;
 658                 else
 659                         goto badlen;
 660
 661 #define hostnamelen     strlen(hostname)
 662                 if (mode == FQDN) {
 663 #ifndef PULLDOWN_TEST
 664                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 665                                          IPPROTO_DONE);
 666 #endif
 667                         n = m_copy(m, 0, M_COPYALL);
 668                         if (n)
 669                                 n = ni6_input(n, off);
 670                         /* XXX meaningless if n == NULL */
 671                         noff = sizeof(struct ip6_hdr);
 672                 } else {
 673                         u_char *p;
 674                         int maxlen, maxhlen;
 675
 676                         if ((icmp6_nodeinfo & 5) != 5)
 677                                 break;
 678
 679                         if (code != 0)
 680                                 goto badcode;
 681                         maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
 682                         if (maxlen >= MCLBYTES) {
 683                                 /* Give up remote */
 684                                 break;
 685                         }
 686                         MGETHDR(n, MB_DONTWAIT, m->m_type);
 687                         if (n && maxlen > MHLEN) {
 688                                 MCLGET(n, MB_DONTWAIT);
 689                                 if ((n->m_flags & M_EXT) == 0) {
 690                                         m_free(n);
 691                                         n = NULL;
 692                                 }
 693                         }
 694                         if (!m_dup_pkthdr(n, m, MB_DONTWAIT)) {
 695                                 /*
 696                                  * Previous code did a blind M_COPY_PKTHDR
 697                                  * and said "just for rcvif".  If true, then
 698                                  * we could tolerate the dup failing (due to
 699                                  * the deep copy of the tag chain).  For now
 700                                  * be conservative and just fail.
 701                                  */
 702                                 m_free(n);
 703                                 n = NULL;
 704                         }
 705                         if (n == NULL) {
 706                                 /* Give up remote */
 707                                 break;
 708                         }
 709                         n->m_pkthdr.rcvif = NULL;
 710                         n->m_len = 0;
 711                         maxhlen = M_TRAILINGSPACE(n) - maxlen;
 712                         if (maxhlen > hostnamelen)
 713                                 maxhlen = hostnamelen;
 714                         /*
 715                          * Copy IPv6 and ICMPv6 only.
 716                          */
 717                         nip6 = mtod(n, struct ip6_hdr *);
 718                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 719                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 720                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 721                         p = (u_char *)(nicmp6 + 1);
 722                         bzero(p, 4);
 723                         bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
 724                         noff = sizeof(struct ip6_hdr);
 725                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 726                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 727                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 728                         nicmp6->icmp6_code = 0;
 729                 }
 730 #undef hostnamelen
 731                 if (n) {
 732                         icmp6stat.icp6s_reflect++;
 733                         icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
 734                         icmp6_reflect(n, noff);
 735                 }
 736                 break;
 737             }
 738
 739         case ICMP6_WRUREPLY:
 740                 if (code != 0)
 741                         goto badcode;
 742                 break;
 743
 744         case ND_ROUTER_SOLICIT:
 745                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
 746                 if (code != 0)
 747                         goto badcode;
 748                 if (icmp6len < sizeof(struct nd_router_solicit))
 749                         goto badlen;
 750                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 751                         /* give up local */
 752                         nd6_rs_input(m, off, icmp6len);
 753                         m = NULL;
 754                         goto freeit;
 755                 }
 756                 nd6_rs_input(n, off, icmp6len);
 757                 /* m stays. */
 758                 break;
 759
 760         case ND_ROUTER_ADVERT:
 761                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
 762                 if (code != 0)
 763                         goto badcode;
 764                 if (icmp6len < sizeof(struct nd_router_advert))
 765                         goto badlen;
 766                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 767                         /* give up local */
 768                         nd6_ra_input(m, off, icmp6len);
 769                         m = NULL;
 770                         goto freeit;
 771                 }
 772                 nd6_ra_input(n, off, icmp6len);
 773                 /* m stays. */
 774                 break;
 775
 776         case ND_NEIGHBOR_SOLICIT:
 777                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
 778                 if (code != 0)
 779                         goto badcode;
 780                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 781                         goto badlen;
 782                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 783                         /* give up local */
 784                         nd6_ns_input(m, off, icmp6len);
 785                         m = NULL;
 786                         goto freeit;
 787                 }
 788                 nd6_ns_input(n, off, icmp6len);
 789                 /* m stays. */
 790                 break;
 791
 792         case ND_NEIGHBOR_ADVERT:
 793                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
 794                 if (code != 0)
 795                         goto badcode;
 796                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 797                         goto badlen;
 798                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 799                         /* give up local */
 800                         nd6_na_input(m, off, icmp6len);
 801                         m = NULL;
 802                         goto freeit;
 803                 }
 804                 nd6_na_input(n, off, icmp6len);
 805                 /* m stays. */
 806                 break;
 807
 808         case ND_REDIRECT:
 809                 icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
 810                 if (code != 0)
 811                         goto badcode;
 812                 if (icmp6len < sizeof(struct nd_redirect))
 813                         goto badlen;
 814                 if ((n = m_copym(m, 0, M_COPYALL, MB_DONTWAIT)) == NULL) {
 815                         /* give up local */
 816                         icmp6_redirect_input(m, off);
 817                         m = NULL;
 818                         goto freeit;
 819                 }
 820                 icmp6_redirect_input(n, off);
 821                 /* m stays. */
 822                 break;
 823
 824         case ICMP6_ROUTER_RENUMBERING:
 825                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 826                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 827                         goto badcode;
 828                 if (icmp6len < sizeof(struct icmp6_router_renum))
 829                         goto badlen;
 830                 break;
 831
 832         default:
 833                 nd6log((LOG_DEBUG,
 834                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 835                     icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
 836                     ip6_sprintf(&ip6->ip6_dst),
 837                     m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
 838                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 839                         /* ICMPv6 error: MUST deliver it by spec... */
 840                         code = PRC_NCMDS;
 841                         /* deliver */
 842                 } else {
 843                         /* ICMPv6 informational: MUST not deliver */
 844                         break;
 845                 }
 846         deliver:
 847                 if (icmp6_notify_error(m, off, icmp6len, code)) {
 848                         /* In this case, m should've been freed. */
 849                         return(IPPROTO_DONE);
 850                 }
 851                 break;
 852
 853         badcode:
 854                 icmp6stat.icp6s_badcode++;
 855                 break;
 856
 857         badlen:
 858                 icmp6stat.icp6s_badlen++;
 859                 break;
 860         }
 861
 862         /* deliver the packet to appropriate sockets */
 863         icmp6_rip6_input(&m, *offp);
 864
 865         return IPPROTO_DONE;
 866
 867  freeit:
 868         m_freem(m);
 869         return IPPROTO_DONE;
 870 }
 871
 872 static int
 873 icmp6_notify_error(struct mbuf *m, int off, int icmp6len, int code)
 874 {
 875         struct icmp6_hdr *icmp6;
 876         struct ip6_hdr *eip6;
 877         u_int32_t notifymtu;
 878         struct sockaddr_in6 icmp6src, icmp6dst;
 879
 880         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 881                 icmp6stat.icp6s_tooshort++;
 882                 goto freeit;
 883         }
 884 #ifndef PULLDOWN_TEST
 885         IP6_EXTHDR_CHECK(m, off,
 886                          sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
 887                          -1);
 888         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 889 #else
 890         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 891                        sizeof(*icmp6) + sizeof(struct ip6_hdr));
 892         if (icmp6 == NULL) {
 893                 icmp6stat.icp6s_tooshort++;
 894                 return(-1);
 895         }
 896 #endif
 897         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 898
 899         /* Detect the upper level protocol */
 900         {
 901                 void (*ctlfunc) (int, struct sockaddr *, void *);
 902                 u_int8_t nxt = eip6->ip6_nxt;
 903                 int eoff = off + sizeof(struct icmp6_hdr) +
 904                         sizeof(struct ip6_hdr);
 905                 struct ip6ctlparam ip6cp;
 906                 struct in6_addr *finaldst = NULL;
 907                 int icmp6type = icmp6->icmp6_type;
 908                 struct ip6_frag *fh;
 909                 struct ip6_rthdr *rth;
 910                 struct ip6_rthdr0 *rth0;
 911                 int rthlen;
 912
 913                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 914                         struct ip6_ext *eh;
 915
 916                         switch (nxt) {
 917                         case IPPROTO_HOPOPTS:
 918                         case IPPROTO_DSTOPTS:
 919                         case IPPROTO_AH:
 920 #ifndef PULLDOWN_TEST
 921                                 IP6_EXTHDR_CHECK(m, 0, eoff +
 922                                                  sizeof(struct ip6_ext),
 923                                                  -1);
 924                                 eh = (struct ip6_ext *)(mtod(m, caddr_t)
 925                                                         + eoff);
 926 #else
 927                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
 928                                                eoff, sizeof(*eh));
 929                                 if (eh == NULL) {
 930                                         icmp6stat.icp6s_tooshort++;
 931                                         return(-1);
 932                                 }
 933 #endif
 934
 935                                 if (nxt == IPPROTO_AH)
 936                                         eoff += (eh->ip6e_len + 2) << 2;
 937                                 else
 938                                         eoff += (eh->ip6e_len + 1) << 3;
 939                                 nxt = eh->ip6e_nxt;
 940                                 break;
 941                         case IPPROTO_ROUTING:
 942                                 /*
 943                                  * When the erroneous packet contains a
 944                                  * routing header, we should examine the
 945                                  * header to determine the final destination.
 946                                  * Otherwise, we can't properly update
 947                                  * information that depends on the final
 948                                  * destination (e.g. path MTU).
 949                                  */
 950 #ifndef PULLDOWN_TEST
 951                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
 952                                                  -1);
 953                                 rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
 954                                                            + eoff);
 955 #else
 956                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
 957                                                eoff, sizeof(*rth));
 958                                 if (rth == NULL) {
 959                                         icmp6stat.icp6s_tooshort++;
 960                                         return(-1);
 961                                 }
 962 #endif
 963                                 rthlen = (rth->ip6r_len + 1) << 3;
 964                                 /*
 965                                  * XXX: currently there is no
 966                                  * officially defined type other
 967                                  * than type-0.
 968                                  * Note that if the segment left field
 969                                  * is 0, all intermediate hops must
 970                                  * have been passed.
 971                                  */
 972                                 if (rth->ip6r_segleft &&
 973                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
 974                                         int hops;
 975
 976 #ifndef PULLDOWN_TEST
 977                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen,
 978                                                          -1);
 979                                         rth0 = (struct ip6_rthdr0 *)(mtod(m, caddr_t) + eoff);
 980 #else
 981                                         IP6_EXTHDR_GET(rth0,
 982                                                        struct ip6_rthdr0 *, m,
 983                                                        eoff, rthlen);
 984                                         if (rth0 == NULL) {
 985                                                 icmp6stat.icp6s_tooshort++;
 986                                                 return(-1);
 987                                         }
 988 #endif
 989                                         /* just ignore a bogus header */
 990                                         if ((rth0->ip6r0_len % 2) == 0 &&
 991                                             (hops = rth0->ip6r0_len/2))
 992                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
 993                                 }
 994                                 eoff += rthlen;
 995                                 nxt = rth->ip6r_nxt;
 996                                 break;
 997                         case IPPROTO_FRAGMENT:
 998 #ifndef PULLDOWN_TEST
 999                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1000                                                  sizeof(struct ip6_frag),
1001                                                  -1);
1002                                 fh = (struct ip6_frag *)(mtod(m, caddr_t)
1003                                                          + eoff);
1004 #else
1005                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1006                                                eoff, sizeof(*fh));
1007                                 if (fh == NULL) {
1008                                         icmp6stat.icp6s_tooshort++;
1009                                         return(-1);
1010                                 }
1011 #endif
1012                                 /*
1013                                  * Data after a fragment header is meaningless
1014                                  * unless it is the first fragment, but
1015                                  * we'll go to the notify label for path MTU
1016                                  * discovery.
1017                                  */
1018                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1019                                         goto notify;
1020
1021                                 eoff += sizeof(struct ip6_frag);
1022                                 nxt = fh->ip6f_nxt;
1023                                 break;
1024                         default:
1025                                 /*
1026                                  * This case includes ESP and the No Next
1027                                  * Header.  In such cases going to the notify
1028                                  * label does not have any meaning
1029                                  * (i.e. ctlfunc will be NULL), but we go
1030                                  * anyway since we might have to update
1031                                  * path MTU information.
1032                                  */
1033                                 goto notify;
1034                         }
1035                 }
1036           notify:
1037 #ifndef PULLDOWN_TEST
1038                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1039 #else
1040                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1041                                sizeof(*icmp6) + sizeof(struct ip6_hdr));
1042                 if (icmp6 == NULL) {
1043                         icmp6stat.icp6s_tooshort++;
1044                         return(-1);
1045                 }
1046 #endif
1047
1048                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1049                 bzero(&icmp6dst, sizeof(icmp6dst));
1050                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1051                 icmp6dst.sin6_family = AF_INET6;
1052                 if (finaldst == NULL)
1053                         icmp6dst.sin6_addr = eip6->ip6_dst;
1054                 else
1055                         icmp6dst.sin6_addr = *finaldst;
1056                 icmp6dst.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1057                                                           &icmp6dst.sin6_addr);
1058 #ifndef SCOPEDROUTING
1059                 if (in6_embedscope(&icmp6dst.sin6_addr, &icmp6dst,
1060                                    NULL, NULL)) {
1061                         /* should be impossbile */
1062                         nd6log((LOG_DEBUG,
1063                             "icmp6_notify_error: in6_embedscope failed\n"));
1064                         goto freeit;
1065                 }
1066 #endif
1067
1068                 /*
1069                  * retrieve parameters from the inner IPv6 header, and convert
1070                  * them into sockaddr structures.
1071                  */
1072                 bzero(&icmp6src, sizeof(icmp6src));
1073                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1074                 icmp6src.sin6_family = AF_INET6;
1075                 icmp6src.sin6_addr = eip6->ip6_src;
1076                 icmp6src.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1077                                                           &icmp6src.sin6_addr);
1078 #ifndef SCOPEDROUTING
1079                 if (in6_embedscope(&icmp6src.sin6_addr, &icmp6src,
1080                                    NULL, NULL)) {
1081                         /* should be impossbile */
1082                         nd6log((LOG_DEBUG,
1083                             "icmp6_notify_error: in6_embedscope failed\n"));
1084                         goto freeit;
1085                 }
1086 #endif
1087                 icmp6src.sin6_flowinfo =
1088                         (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1089
1090                 if (finaldst == NULL)
1091                         finaldst = &eip6->ip6_dst;
1092                 ip6cp.ip6c_m = m;
1093                 ip6cp.ip6c_icmp6 = icmp6;
1094                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1095                 ip6cp.ip6c_off = eoff;
1096                 ip6cp.ip6c_finaldst = finaldst;
1097                 ip6cp.ip6c_src = &icmp6src;
1098                 ip6cp.ip6c_nxt = nxt;
1099
1100                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1101                         notifymtu = ntohl(icmp6->icmp6_mtu);
1102                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1103                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1104                 }
1105
1106                 ctlfunc = (void (*) (int, struct sockaddr *, void *))
1107                         (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1108                 if (ctlfunc) {
1109                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1110                                           &ip6cp);
1111                 }
1112         }
1113         return(0);
1114
1115   freeit:
1116         m_freem(m);
1117         return(-1);
1118 }
1119
1120 void
1121 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1122 {
1123         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1124         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1125         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1126         u_int mtu = ntohl(icmp6->icmp6_mtu);
1127         struct rtentry *rt = NULL;
1128         struct sockaddr_in6 sin6;
1129
1130         if (!validated)
1131                 return;
1132
1133         bzero(&sin6, sizeof(sin6));
1134         sin6.sin6_family = PF_INET6;
1135         sin6.sin6_len = sizeof(struct sockaddr_in6);
1136         sin6.sin6_addr = *dst;
1137         /* XXX normally, this won't happen */
1138         if (IN6_IS_ADDR_LINKLOCAL(dst)) {
1139                 sin6.sin6_addr.s6_addr16[1] =
1140                     htons(m->m_pkthdr.rcvif->if_index);
1141         }
1142         /* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
1143         rt = rtlookup((struct sockaddr *)&sin6, 0, RTF_CLONING | RTF_PRCLONING);
1144
1145         if (rt && (rt->rt_flags & RTF_HOST) &&
1146             !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
1147                 if (mtu < IPV6_MMTU) {                          /* XXX */
1148                         rt->rt_rmx.rmx_locks |= RTV_MTU;
1149                 } else if (mtu < rt->rt_ifp->if_mtu &&
1150                            rt->rt_rmx.rmx_mtu > mtu) {
1151                         icmp6stat.icp6s_pmtuchg++;
1152                         rt->rt_rmx.rmx_mtu = mtu;
1153                 }
1154         }
1155         if (rt)
1156                 --rt->rt_refcnt;
1157 }
1158
1159 /*
1160  * Process a Node Information Query packet, based on
1161  * draft-ietf-ipngwg-icmp-name-lookups-07.
1162  *
1163  * Spec incompatibilities:
1164  * - IPv6 Subject address handling
1165  * - IPv4 Subject address handling support missing
1166  * - Proxy reply (answer even if it's not for me)
1167  * - joins NI group address at in6_ifattach() time only, does not cope
1168  *   with hostname changes by sethostname(3)
1169  */
1170 #define hostnamelen     strlen(hostname)
1171 static struct mbuf *
1172 ni6_input(struct mbuf *m, int off)
1173 {
1174         struct icmp6_nodeinfo *ni6, *nni6;
1175         struct mbuf *n = NULL;
1176         u_int16_t qtype;
1177         int subjlen;
1178         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1179         struct ni_reply_fqdn *fqdn;
1180         int addrs;              /* for NI_QTYPE_NODEADDR */
1181         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1182         struct sockaddr_in6 sin6; /* double meaning; ip6_dst and subjectaddr */
1183         struct sockaddr_in6 sin6_d; /* XXX: we should retrieve this from m_aux */
1184         struct ip6_hdr *ip6;
1185         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1186         char *subj = NULL;
1187         struct in6_ifaddr *ia6 = NULL;
1188
1189         ip6 = mtod(m, struct ip6_hdr *);
1190 #ifndef PULLDOWN_TEST
1191         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1192 #else
1193         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1194         if (ni6 == NULL) {
1195                 /* m is already reclaimed */
1196                 return NULL;
1197         }
1198 #endif
1199
1200         /*
1201          * Validate IPv6 destination address.
1202          *
1203          * The Responder must discard the Query without further processing
1204          * unless it is one of the Responder's unicast or anycast addresses, or
1205          * a link-local scope multicast address which the Responder has joined.
1206          * [icmp-name-lookups-07, Section 4.]
1207          */
1208         bzero(&sin6, sizeof(sin6));
1209         sin6.sin6_family = AF_INET6;
1210         sin6.sin6_len = sizeof(struct sockaddr_in6);
1211         bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
1212         /* XXX scopeid */
1213         if ((ia6 = (struct in6_ifaddr *)ifa_ifwithaddr((struct sockaddr *)&sin6)) != NULL) {
1214                 /* unicast/anycast, fine */
1215                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1216                     (icmp6_nodeinfo & 4) == 0) {
1217                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1218                                 "a temporary address in %s:%d",
1219                                __FILE__, __LINE__));
1220                         goto bad;
1221                 }
1222         } else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
1223                 ; /* link-local multicast, fine */
1224         else
1225                 goto bad;
1226
1227         /* validate query Subject field. */
1228         qtype = ntohs(ni6->ni_qtype);
1229         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1230         switch (qtype) {
1231         case NI_QTYPE_NOOP:
1232         case NI_QTYPE_SUPTYPES:
1233                 /* 07 draft */
1234                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1235                         break;
1236                 /* FALLTHROUGH */
1237         case NI_QTYPE_FQDN:
1238         case NI_QTYPE_NODEADDR:
1239                 switch (ni6->ni_code) {
1240                 case ICMP6_NI_SUBJ_IPV6:
1241 #if ICMP6_NI_SUBJ_IPV6 != 0
1242                 case 0:
1243 #endif
1244                         /*
1245                          * backward compatibility - try to accept 03 draft
1246                          * format, where no Subject is present.
1247                          */
1248                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1249                             subjlen == 0) {
1250                                 oldfqdn++;
1251                                 break;
1252                         }
1253 #if ICMP6_NI_SUBJ_IPV6 != 0
1254                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1255                                 goto bad;
1256 #endif
1257
1258                         if (subjlen != sizeof(sin6.sin6_addr))
1259                                 goto bad;
1260
1261                         /*
1262                          * Validate Subject address.
1263                          *
1264                          * Not sure what exactly "address belongs to the node"
1265                          * means in the spec, is it just unicast, or what?
1266                          *
1267                          * At this moment we consider Subject address as
1268                          * "belong to the node" if the Subject address equals
1269                          * to the IPv6 destination address; validation for
1270                          * IPv6 destination address should have done enough
1271                          * check for us.
1272                          *
1273                          * We do not do proxy at this moment.
1274                          */
1275                         /* m_pulldown instead of copy? */
1276                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1277                             subjlen, (caddr_t)&sin6.sin6_addr);
1278                         sin6.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1279                                                               &sin6.sin6_addr);
1280 #ifndef SCOPEDROUTING
1281                         in6_embedscope(&sin6.sin6_addr, &sin6, NULL, NULL);
1282 #endif
1283                         bzero(&sin6_d, sizeof(sin6_d));
1284                         sin6_d.sin6_family = AF_INET6; /* not used, actually */
1285                         sin6_d.sin6_len = sizeof(sin6_d); /* ditto */
1286                         sin6_d.sin6_addr = ip6->ip6_dst;
1287                         sin6_d.sin6_scope_id = in6_addr2scopeid(m->m_pkthdr.rcvif,
1288                                                                 &ip6->ip6_dst);
1289 #ifndef SCOPEDROUTING
1290                         in6_embedscope(&sin6_d.sin6_addr, &sin6_d, NULL, NULL);
1291 #endif
1292                         subj = (char *)&sin6;
1293                         if (SA6_ARE_ADDR_EQUAL(&sin6, &sin6_d))
1294                                 break;
1295
1296                         /*
1297                          * XXX if we are to allow other cases, we should really
1298                          * be careful about scope here.
1299                          * basically, we should disallow queries toward IPv6
1300                          * destination X with subject Y, if scope(X) > scope(Y).
1301                          * if we allow scope(X) > scope(Y), it will result in
1302                          * information leakage across scope boundary.
1303                          */
1304                         goto bad;
1305
1306                 case ICMP6_NI_SUBJ_FQDN:
1307                         /*
1308                          * Validate Subject name with gethostname(3).
1309                          *
1310                          * The behavior may need some debate, since:
1311                          * - we are not sure if the node has FQDN as
1312                          *   hostname (returned by gethostname(3)).
1313                          * - the code does wildcard match for truncated names.
1314                          *   however, we are not sure if we want to perform
1315                          *   wildcard match, if gethostname(3) side has
1316                          *   truncated hostname.
1317                          */
1318                         n = ni6_nametodns(hostname, hostnamelen, 0);
1319                         if (!n || n->m_next || n->m_len == 0)
1320                                 goto bad;
1321                         IP6_EXTHDR_GET(subj, char *, m,
1322                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1323                         if (subj == NULL)
1324                                 goto bad;
1325                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1326                                         n->m_len)) {
1327                                 goto bad;
1328                         }
1329                         m_freem(n);
1330                         n = NULL;
1331                         break;
1332
1333                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1334                 default:
1335                         goto bad;
1336                 }
1337                 break;
1338         }
1339
1340         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1341         switch (qtype) {
1342         case NI_QTYPE_FQDN:
1343                 if ((icmp6_nodeinfo & 1) == 0)
1344                         goto bad;
1345                 break;
1346         case NI_QTYPE_NODEADDR:
1347                 if ((icmp6_nodeinfo & 2) == 0)
1348                         goto bad;
1349                 break;
1350         }
1351
1352         /* guess reply length */
1353         switch (qtype) {
1354         case NI_QTYPE_NOOP:
1355                 break;          /* no reply data */
1356         case NI_QTYPE_SUPTYPES:
1357                 replylen += sizeof(u_int32_t);
1358                 break;
1359         case NI_QTYPE_FQDN:
1360                 /* XXX will append an mbuf */
1361                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1362                 break;
1363         case NI_QTYPE_NODEADDR:
1364                 addrs = ni6_addrs(ni6, m, &ifp, subj);
1365                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1366                                           sizeof(u_int32_t))) > MCLBYTES)
1367                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1368                 break;
1369         default:
1370                 /*
1371                  * XXX: We must return a reply with the ICMP6 code
1372                  * `unknown Qtype' in this case. However we regard the case
1373                  * as an FQDN query for backward compatibility.
1374                  * Older versions set a random value to this field,
1375                  * so it rarely varies in the defined qtypes.
1376                  * But the mechanism is not reliable...
1377                  * maybe we should obsolete older versions.
1378                  */
1379                 qtype = NI_QTYPE_FQDN;
1380                 /* XXX will append an mbuf */
1381                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1382                 oldfqdn++;
1383                 break;
1384         }
1385
1386         /* allocate an mbuf to reply. */
1387         MGETHDR(n, MB_DONTWAIT, m->m_type);
1388         if (n == NULL) {
1389                 m_freem(m);
1390                 return(NULL);
1391         }
1392         M_MOVE_PKTHDR(n, m); /* just for recvif */
1393         if (replylen > MHLEN) {
1394                 if (replylen > MCLBYTES) {
1395                         /*
1396                          * XXX: should we try to allocate more? But MCLBYTES
1397                          * is probably much larger than IPV6_MMTU...
1398                          */
1399                         goto bad;
1400                 }
1401                 MCLGET(n, MB_DONTWAIT);
1402                 if ((n->m_flags & M_EXT) == 0) {
1403                         goto bad;
1404                 }
1405         }
1406         n->m_pkthdr.len = n->m_len = replylen;
1407
1408         /* copy mbuf header and IPv6 + Node Information base headers */
1409         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1410         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1411         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1412
1413         /* qtype dependent procedure */
1414         switch (qtype) {
1415         case NI_QTYPE_NOOP:
1416                 nni6->ni_code = ICMP6_NI_SUCCESS;
1417                 nni6->ni_flags = 0;
1418                 break;
1419         case NI_QTYPE_SUPTYPES:
1420         {
1421                 u_int32_t v;
1422                 nni6->ni_code = ICMP6_NI_SUCCESS;
1423                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1424                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1425                 v = (u_int32_t)htonl(0x0000000f);
1426                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1427                 break;
1428         }
1429         case NI_QTYPE_FQDN:
1430                 nni6->ni_code = ICMP6_NI_SUCCESS;
1431                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1432                                                 sizeof(struct ip6_hdr) +
1433                                                 sizeof(struct icmp6_nodeinfo));
1434                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1435                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1436                 /*
1437                  * XXX do we really have FQDN in variable "hostname"?
1438                  */
1439                 n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
1440                 if (n->m_next == NULL)
1441                         goto bad;
1442                 /* XXX we assume that n->m_next is not a chain */
1443                 if (n->m_next->m_next != NULL)
1444                         goto bad;
1445                 n->m_pkthdr.len += n->m_next->m_len;
1446                 break;
1447         case NI_QTYPE_NODEADDR:
1448         {
1449                 int lenlim, copied;
1450
1451                 nni6->ni_code = ICMP6_NI_SUCCESS;
1452                 n->m_pkthdr.len = n->m_len =
1453                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1454                 lenlim = M_TRAILINGSPACE(n);
1455                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1456                 /* XXX: reset mbuf length */
1457                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1458                         sizeof(struct icmp6_nodeinfo) + copied;
1459                 break;
1460         }
1461         default:
1462                 break;          /* XXX impossible! */
1463         }
1464
1465         nni6->ni_type = ICMP6_NI_REPLY;
1466         m_freem(m);
1467         return(n);
1468
1469   bad:
1470         m_freem(m);
1471         if (n)
1472                 m_freem(n);
1473         return(NULL);
1474 }
1475 #undef hostnamelen
1476
1477 /*
1478  * make a mbuf with DNS-encoded string.  no compression support.
1479  *
1480  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1481  * treated as truncated name (two \0 at the end).  this is a wild guess.
1482  */
1483 static struct mbuf *
1484 ni6_nametodns(const char *name, int namelen,
1485               int old) /* return pascal string if non-zero */
1486 {
1487         struct mbuf *m;
1488         char *cp, *ep;
1489         const char *p, *q;
1490         int i, len, nterm;
1491
1492         if (old)
1493                 len = namelen + 1;
1494         else
1495                 len = MCLBYTES;
1496
1497         /* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
1498         MGET(m, MB_DONTWAIT, MT_DATA);
1499         if (m && len > MLEN) {
1500                 MCLGET(m, MB_DONTWAIT);
1501                 if ((m->m_flags & M_EXT) == 0)
1502                         goto fail;
1503         }
1504         if (!m)
1505                 goto fail;
1506         m->m_next = NULL;
1507
1508         if (old) {
1509                 m->m_len = len;
1510                 *mtod(m, char *) = namelen;
1511                 bcopy(name, mtod(m, char *) + 1, namelen);
1512                 return m;
1513         } else {
1514                 m->m_len = 0;
1515                 cp = mtod(m, char *);
1516                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1517
1518                 /* if not certain about my name, return empty buffer */
1519                 if (namelen == 0)
1520                         return m;
1521
1522                 /*
1523                  * guess if it looks like shortened hostname, or FQDN.
1524                  * shortened hostname needs two trailing "\0".
1525                  */
1526                 i = 0;
1527                 for (p = name; p < name + namelen; p++) {
1528                         if (*p && *p == '.')
1529                                 i++;
1530                 }
1531                 if (i < 2)
1532                         nterm = 2;
1533                 else
1534                         nterm = 1;
1535
1536                 p = name;
1537                 while (cp < ep && p < name + namelen) {
1538                         i = 0;
1539                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1540                                 i++;
1541                         /* result does not fit into mbuf */
1542                         if (cp + i + 1 >= ep)
1543                                 goto fail;
1544                         /*
1545                          * DNS label length restriction, RFC1035 page 8.
1546                          * "i == 0" case is included here to avoid returning
1547                          * 0-length label on "foo..bar".
1548                          */
1549                         if (i <= 0 || i >= 64)
1550                                 goto fail;
1551                         *cp++ = i;
1552                         bcopy(p, cp, i);
1553                         cp += i;
1554                         p = q;
1555                         if (p < name + namelen && *p == '.')
1556                                 p++;
1557                 }
1558                 /* termination */
1559                 if (cp + nterm >= ep)
1560                         goto fail;
1561                 while (nterm-- > 0)
1562                         *cp++ = '\0';
1563                 m->m_len = cp - mtod(m, char *);
1564                 return m;
1565         }
1566
1567         panic("should not reach here");
1568         /* NOTREACHED */
1569
1570  fail:
1571         if (m)
1572                 m_freem(m);
1573         return NULL;
1574 }
1575
1576 /*
1577  * check if two DNS-encoded string matches.  takes care of truncated
1578  * form (with \0\0 at the end).  no compression support.
1579  * XXX upper/lowercase match (see RFC2065)
1580  */
1581 static int
1582 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1583 {
1584         const char *a0, *b0;
1585         int l;
1586
1587         /* simplest case - need validation? */
1588         if (alen == blen && bcmp(a, b, alen) == 0)
1589                 return 1;
1590
1591         a0 = a;
1592         b0 = b;
1593
1594         /* termination is mandatory */
1595         if (alen < 2 || blen < 2)
1596                 return 0;
1597         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1598                 return 0;
1599         alen--;
1600         blen--;
1601
1602         while (a - a0 < alen && b - b0 < blen) {
1603                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1604                         return 0;
1605
1606                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1607                         return 0;
1608                 /* we don't support compression yet */
1609                 if (a[0] >= 64 || b[0] >= 64)
1610                         return 0;
1611
1612                 /* truncated case */
1613                 if (a[0] == 0 && a - a0 == alen - 1)
1614                         return 1;
1615                 if (b[0] == 0 && b - b0 == blen - 1)
1616                         return 1;
1617                 if (a[0] == 0 || b[0] == 0)
1618                         return 0;
1619
1620                 if (a[0] != b[0])
1621                         return 0;
1622                 l = a[0];
1623                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1624                         return 0;
1625                 if (bcmp(a + 1, b + 1, l) != 0)
1626                         return 0;
1627
1628                 a += 1 + l;
1629                 b += 1 + l;
1630         }
1631
1632         if (a - a0 == alen && b - b0 == blen)
1633                 return 1;
1634         else
1635                 return 0;
1636 }
1637
1638 /*
1639  * calculate the number of addresses to be returned in the node info reply.
1640  */
1641 static int
1642 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1643           char *subj)
1644 {
1645         struct ifnet *ifp;
1646         struct in6_ifaddr *ifa6;
1647         struct ifaddr *ifa;
1648         struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
1649         int addrs = 0, addrsofif, iffound = 0;
1650         int niflags = ni6->ni_flags;
1651
1652         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1653                 switch (ni6->ni_code) {
1654                 case ICMP6_NI_SUBJ_IPV6:
1655                         if (subj == NULL) /* must be impossible... */
1656                                 return(0);
1657                         subj_ip6 = (struct sockaddr_in6 *)subj;
1658                         break;
1659                 default:
1660                         /*
1661                          * XXX: we only support IPv6 subject address for
1662                          * this Qtype.
1663                          */
1664                         return(0);
1665                 }
1666         }
1667
1668         for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
1669         {
1670                 addrsofif = 0;
1671                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list)
1672                 {
1673                         if (ifa->ifa_addr->sa_family != AF_INET6)
1674                                 continue;
1675                         ifa6 = (struct in6_ifaddr *)ifa;
1676
1677                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1678                             IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
1679                                                &ifa6->ia_addr.sin6_addr))
1680                                 iffound = 1;
1681
1682                         /*
1683                          * IPv4-mapped addresses can only be returned by a
1684                          * Node Information proxy, since they represent
1685                          * addresses of IPv4-only nodes, which perforce do
1686                          * not implement this protocol.
1687                          * [icmp-name-lookups-07, Section 5.4]
1688                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1689                          * this function at this moment.
1690                          */
1691
1692                         /* What do we have to do about ::1? */
1693                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1694                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1695                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1696                                         continue;
1697                                 break;
1698                         case IPV6_ADDR_SCOPE_SITELOCAL:
1699                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1700                                         continue;
1701                                 break;
1702                         case IPV6_ADDR_SCOPE_GLOBAL:
1703                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1704                                         continue;
1705                                 break;
1706                         default:
1707                                 continue;
1708                         }
1709
1710                         /*
1711                          * check if anycast is okay.
1712                          * XXX: just experimental.  not in the spec.
1713                          */
1714                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1715                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1716                                 continue; /* we need only unicast addresses */
1717                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1718                             (icmp6_nodeinfo & 4) == 0) {
1719                                 continue;
1720                         }
1721                         addrsofif++; /* count the address */
1722                 }
1723                 if (iffound) {
1724                         *ifpp = ifp;
1725                         return(addrsofif);
1726                 }
1727
1728                 addrs += addrsofif;
1729         }
1730
1731         return(addrs);
1732 }
1733
1734 static int
1735 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1736                 struct ifnet *ifp0, int resid)
1737 {
1738         struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
1739         struct in6_ifaddr *ifa6;
1740         struct ifaddr *ifa;
1741         struct ifnet *ifp_dep = NULL;
1742         int copied = 0, allow_deprecated = 0;
1743         u_char *cp = (u_char *)(nni6 + 1);
1744         int niflags = ni6->ni_flags;
1745         u_int32_t ltime;
1746
1747         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1748                 return(0);      /* needless to copy */
1749
1750   again:
1751
1752         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
1753         {
1754                 TAILQ_FOREACH(ifa, &ifp->if_addrlist, ifa_list) {
1755                         if (ifa->ifa_addr->sa_family != AF_INET6)
1756                                 continue;
1757                         ifa6 = (struct in6_ifaddr *)ifa;
1758
1759                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1760                             allow_deprecated == 0) {
1761                                 /*
1762                                  * prefererred address should be put before
1763                                  * deprecated addresses.
1764                                  */
1765
1766                                 /* record the interface for later search */
1767                                 if (ifp_dep == NULL)
1768                                         ifp_dep = ifp;
1769
1770                                 continue;
1771                         }
1772                         else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1773                                  allow_deprecated != 0)
1774                                 continue; /* we now collect deprecated addrs */
1775
1776                         /* What do we have to do about ::1? */
1777                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1778                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1779                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1780                                         continue;
1781                                 break;
1782                         case IPV6_ADDR_SCOPE_SITELOCAL:
1783                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1784                                         continue;
1785                                 break;
1786                         case IPV6_ADDR_SCOPE_GLOBAL:
1787                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1788                                         continue;
1789                                 break;
1790                         default:
1791                                 continue;
1792                         }
1793
1794                         /*
1795                          * check if anycast is okay.
1796                          * XXX: just experimental. not in the spec.
1797                          */
1798                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1799                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1800                                 continue;
1801                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1802                             (icmp6_nodeinfo & 4) == 0) {
1803                                 continue;
1804                         }
1805
1806                         /* now we can copy the address */
1807                         if (resid < sizeof(struct in6_addr) +
1808                             sizeof(u_int32_t)) {
1809                                 /*
1810                                  * We give up much more copy.
1811                                  * Set the truncate flag and return.
1812                                  */
1813                                 nni6->ni_flags |=
1814                                         NI_NODEADDR_FLAG_TRUNCATE;
1815                                 return(copied);
1816                         }
1817
1818                         /*
1819                          * Set the TTL of the address.
1820                          * The TTL value should be one of the following
1821                          * according to the specification:
1822                          *
1823                          * 1. The remaining lifetime of a DHCP lease on the
1824                          *    address, or
1825                          * 2. The remaining Valid Lifetime of a prefix from
1826                          *    which the address was derived through Stateless
1827                          *    Autoconfiguration.
1828                          *
1829                          * Note that we currently do not support stateful
1830                          * address configuration by DHCPv6, so the former
1831                          * case can't happen.
1832                          */
1833                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1834                                 ltime = ND6_INFINITE_LIFETIME;
1835                         else {
1836                                 if (ifa6->ia6_lifetime.ia6t_expire >
1837                                     time_second)
1838                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
1839                                 else
1840                                         ltime = 0;
1841                         }
1842
1843                         bcopy(&ltime, cp, sizeof(u_int32_t));
1844                         cp += sizeof(u_int32_t);
1845
1846                         /* copy the address itself */
1847                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1848                               sizeof(struct in6_addr));
1849                         /* XXX: KAME link-local hack; remove ifindex */
1850                         if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
1851                                 ((struct in6_addr *)cp)->s6_addr16[1] = 0;
1852                         cp += sizeof(struct in6_addr);
1853
1854                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1855                         copied += (sizeof(struct in6_addr) +
1856                                    sizeof(u_int32_t));
1857                 }
1858                 if (ifp0)       /* we need search only on the specified IF */
1859                         break;
1860         }
1861
1862         if (allow_deprecated == 0 && ifp_dep != NULL) {
1863                 ifp = ifp_dep;
1864                 allow_deprecated = 1;
1865
1866                 goto again;
1867         }
1868
1869         return(copied);
1870 }
1871
1872 /*
1873  * XXX almost dup'ed code with rip6_input.
1874  */
1875 static int
1876 icmp6_rip6_input(struct mbuf **mp, int  off)
1877 {
1878         struct mbuf *m = *mp;
1879         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1880         struct in6pcb *in6p;
1881         struct in6pcb *last = NULL;
1882         struct sockaddr_in6 rip6src;
1883         struct icmp6_hdr *icmp6;
1884         struct mbuf *opts = NULL;
1885
1886 #ifndef PULLDOWN_TEST
1887         /* this is assumed to be safe. */
1888         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1889 #else
1890         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1891         if (icmp6 == NULL) {
1892                 /* m is already reclaimed */
1893                 return IPPROTO_DONE;
1894         }
1895 #endif
1896
1897         bzero(&rip6src, sizeof(rip6src));
1898         rip6src.sin6_len = sizeof(struct sockaddr_in6);
1899         rip6src.sin6_family = AF_INET6;
1900         /* KAME hack: recover scopeid */
1901         (void)in6_recoverscope(&rip6src, &ip6->ip6_src, m->m_pkthdr.rcvif);
1902
1903         LIST_FOREACH(in6p, &ripcbinfo.pcblisthead, inp_list)
1904         {
1905                 if (in6p->inp_flags & INP_PLACEMARKER)
1906                         continue;
1907                 if ((in6p->inp_vflag & INP_IPV6) == 0)
1908                         continue;
1909 #ifdef HAVE_NRL_INPCB
1910                 if (!(in6p->in6p_flags & INP_IPV6))
1911                         continue;
1912 #endif
1913                 if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
1914                         continue;
1915                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
1916                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
1917                         continue;
1918                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
1919                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
1920                         continue;
1921                 if (in6p->in6p_icmp6filt
1922                     && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
1923                                  in6p->in6p_icmp6filt))
1924                         continue;
1925                 if (last) {
1926                         struct  mbuf *n;
1927                         if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
1928                                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1929                                         ip6_savecontrol(last, &opts, ip6, n);
1930                                 /* strip intermediate headers */
1931                                 m_adj(n, off);
1932                                 if (sbappendaddr(&last->in6p_socket->so_rcv,
1933                                                  (struct sockaddr *)&rip6src,
1934                                                  n, opts) == 0) {
1935                                         /* should notify about lost packet */
1936                                         m_freem(n);
1937                                         if (opts) {
1938                                                 m_freem(opts);
1939                                         }
1940                                 } else
1941                                         sorwakeup(last->in6p_socket);
1942                                 opts = NULL;
1943                         }
1944                 }
1945                 last = in6p;
1946         }
1947         if (last) {
1948                 if (last->in6p_flags & IN6P_CONTROLOPTS)
1949                         ip6_savecontrol(last, &opts, ip6, m);
1950                 /* strip intermediate headers */
1951                 m_adj(m, off);
1952                 if (sbappendaddr(&last->in6p_socket->so_rcv,
1953                                  (struct sockaddr *)&rip6src, m, opts) == 0) {
1954                         m_freem(m);
1955                         if (opts)
1956                                 m_freem(opts);
1957                 } else
1958                         sorwakeup(last->in6p_socket);
1959         } else {
1960                 m_freem(m);
1961                 ip6stat.ip6s_delivered--;
1962         }
1963         return IPPROTO_DONE;
1964 }
1965
1966 /*
1967  * Reflect the ip6 packet back to the source.
1968  * OFF points to the icmp6 header, counted from the top of the mbuf.
1969  */
1970 void
1971 icmp6_reflect(struct mbuf *m, size_t off)
1972 {
1973         struct ip6_hdr *ip6;
1974         struct icmp6_hdr *icmp6;
1975         struct in6_ifaddr *ia;
1976         struct in6_addr t, *src = 0;
1977         int plen;
1978         int type, code;
1979         struct ifnet *outif = NULL;
1980         struct sockaddr_in6 sa6_src, sa6_dst;
1981 #ifdef COMPAT_RFC1885
1982         int mtu = IPV6_MMTU;
1983         struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
1984 #endif
1985
1986         /* too short to reflect */
1987         if (off < sizeof(struct ip6_hdr)) {
1988                 nd6log((LOG_DEBUG,
1989                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
1990                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
1991                     __FILE__, __LINE__));
1992                 goto bad;
1993         }
1994
1995         /*
1996          * If there are extra headers between IPv6 and ICMPv6, strip
1997          * off that header first.
1998          */
1999 #ifdef DIAGNOSTIC
2000         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2001                 panic("assumption failed in icmp6_reflect");
2002 #endif
2003         if (off > sizeof(struct ip6_hdr)) {
2004                 size_t l;
2005                 struct ip6_hdr nip6;
2006
2007                 l = off - sizeof(struct ip6_hdr);
2008                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2009                 m_adj(m, l);
2010                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2011                 if (m->m_len < l) {
2012                         if ((m = m_pullup(m, l)) == NULL)
2013                                 return;
2014                 }
2015                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2016         } else /* off == sizeof(struct ip6_hdr) */ {
2017                 size_t l;
2018                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2019                 if (m->m_len < l) {
2020                         if ((m = m_pullup(m, l)) == NULL)
2021                                 return;
2022                 }
2023         }
2024         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2025         ip6 = mtod(m, struct ip6_hdr *);
2026         ip6->ip6_nxt = IPPROTO_ICMPV6;
2027         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2028         type = icmp6->icmp6_type; /* keep type for statistics */
2029         code = icmp6->icmp6_code; /* ditto. */
2030
2031         t = ip6->ip6_dst;
2032         /*
2033          * ip6_input() drops a packet if its src is multicast.
2034          * So, the src is never multicast.
2035          */
2036         ip6->ip6_dst = ip6->ip6_src;
2037
2038         /*
2039          * XXX: make sure to embed scope zone information, using
2040          * already embedded IDs or the received interface (if any).
2041          * Note that rcvif may be NULL.
2042          * TODO: scoped routing case (XXX).
2043          */
2044         bzero(&sa6_src, sizeof(sa6_src));
2045         sa6_src.sin6_family = AF_INET6;
2046         sa6_src.sin6_len = sizeof(sa6_src);
2047         sa6_src.sin6_addr = ip6->ip6_dst;
2048         in6_recoverscope(&sa6_src, &ip6->ip6_dst, m->m_pkthdr.rcvif);
2049         in6_embedscope(&ip6->ip6_dst, &sa6_src, NULL, NULL);
2050         bzero(&sa6_dst, sizeof(sa6_dst));
2051         sa6_dst.sin6_family = AF_INET6;
2052         sa6_dst.sin6_len = sizeof(sa6_dst);
2053         sa6_dst.sin6_addr = t;
2054         in6_recoverscope(&sa6_dst, &t, m->m_pkthdr.rcvif);
2055         in6_embedscope(&t, &sa6_dst, NULL, NULL);
2056
2057 #ifdef COMPAT_RFC1885
2058         /*
2059          * xxx guess MTU
2060          * RFC 1885 requires that echo reply should be truncated if it
2061          * does not fit in with (return) path MTU, but the description was
2062          * removed in the new spec.
2063          */
2064         if (icmp6_reflect_rt.ro_rt == 0 ||
2065             ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
2066                 if (icmp6_reflect_rt.ro_rt) {
2067                         RTFREE(icmp6_reflect_rt.ro_rt);
2068                         icmp6_reflect_rt.ro_rt = 0;
2069                 }
2070                 bzero(sin6, sizeof(*sin6));
2071                 sin6->sin6_family = PF_INET6;
2072                 sin6->sin6_len = sizeof(struct sockaddr_in6);
2073                 sin6->sin6_addr = ip6->ip6_dst;
2074
2075                 rtalloc_ign((struct route *)&icmp6_reflect_rt.ro_rt,
2076                             RTF_PRCLONING);
2077         }
2078
2079         if (icmp6_reflect_rt.ro_rt == 0)
2080                 goto bad;
2081
2082         if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
2083             && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
2084                 mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
2085
2086         if (mtu < m->m_pkthdr.len) {
2087                 plen -= (m->m_pkthdr.len - mtu);
2088                 m_adj(m, mtu - m->m_pkthdr.len);
2089         }
2090 #endif
2091         /*
2092          * If the incoming packet was addressed directly to us(i.e. unicast),
2093          * use dst as the src for the reply.
2094          * The IN6_IFF_NOTREADY case would be VERY rare, but is possible
2095          * (for example) when we encounter an error while forwarding procedure
2096          * destined to a duplicated address of ours.
2097          */
2098         for (ia = in6_ifaddr; ia; ia = ia->ia_next)
2099                 if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
2100                     (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
2101                         src = &t;
2102                         break;
2103                 }
2104         if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
2105                 /*
2106                  * This is the case if the dst is our link-local address
2107                  * and the sender is also ourselves.
2108                  */
2109                 src = &t;
2110         }
2111
2112         if (src == 0) {
2113                 int e;
2114                 struct route_in6 ro;
2115
2116                 /*
2117                  * This case matches to multicasts, our anycast, or unicasts
2118                  * that we do not own.  Select a source address based on the
2119                  * source address of the erroneous packet.
2120                  */
2121                 bzero(&ro, sizeof(ro));
2122                 src = in6_selectsrc(&sa6_src, NULL, NULL, &ro, NULL, &e);
2123                 if (ro.ro_rt)
2124                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2125                 if (src == NULL) {
2126                         nd6log((LOG_DEBUG,
2127                             "icmp6_reflect: source can't be determined: "
2128                             "dst=%s, error=%d\n",
2129                             ip6_sprintf(&sa6_src.sin6_addr), e));
2130                         goto bad;
2131                 }
2132         }
2133
2134         ip6->ip6_src = *src;
2135
2136         ip6->ip6_flow = 0;
2137         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2138         ip6->ip6_vfc |= IPV6_VERSION;
2139         ip6->ip6_nxt = IPPROTO_ICMPV6;
2140         if (m->m_pkthdr.rcvif) {
2141                 /* XXX: This may not be the outgoing interface */
2142                 ip6->ip6_hlim = nd_ifinfo[m->m_pkthdr.rcvif->if_index].chlim;
2143         } else
2144                 ip6->ip6_hlim = ip6_defhlim;
2145
2146         icmp6->icmp6_cksum = 0;
2147         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2148                                         sizeof(struct ip6_hdr), plen);
2149
2150         /*
2151          * XXX option handling
2152          */
2153
2154         m->m_flags &= ~(M_BCAST|M_MCAST);
2155
2156 #ifdef COMPAT_RFC1885
2157         ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif, NULL);
2158 #else
2159         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2160 #endif
2161         if (outif)
2162                 icmp6_ifoutstat_inc(outif, type, code);
2163
2164         return;
2165
2166  bad:
2167         m_freem(m);
2168         return;
2169 }
2170
2171 void
2172 icmp6_fasttimo(void)
2173 {
2174
2175         mld6_fasttimeo();
2176 }
2177
2178 static const char *
2179 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2180                     struct in6_addr *tgt6)
2181 {
2182         static char buf[1024];
2183         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2184                 ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
2185         return buf;
2186 }
2187
2188 void
2189 icmp6_redirect_input(struct mbuf *m, int off)
2190 {
2191         struct ifnet *ifp = m->m_pkthdr.rcvif;
2192         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2193         struct nd_redirect *nd_rd;
2194         int icmp6len = ntohs(ip6->ip6_plen);
2195         char *lladdr = NULL;
2196         int lladdrlen = 0;
2197         u_char *redirhdr = NULL;
2198         int redirhdrlen = 0;
2199         struct rtentry *rt = NULL;
2200         int is_router;
2201         int is_onlink;
2202         struct in6_addr src6 = ip6->ip6_src;
2203         struct in6_addr redtgt6;
2204         struct in6_addr reddst6;
2205         union nd_opts ndopts;
2206
2207         if (!m || !ifp)
2208                 return;
2209
2210         /* XXX if we are router, we don't update route by icmp6 redirect */
2211         if (ip6_forwarding)
2212                 goto freeit;
2213         if (!icmp6_rediraccept)
2214                 goto freeit;
2215
2216 #ifndef PULLDOWN_TEST
2217         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2218         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2219 #else
2220         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2221         if (nd_rd == NULL) {
2222                 icmp6stat.icp6s_tooshort++;
2223                 return;
2224         }
2225 #endif
2226         redtgt6 = nd_rd->nd_rd_target;
2227         reddst6 = nd_rd->nd_rd_dst;
2228
2229         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2230                 redtgt6.s6_addr16[1] = htons(ifp->if_index);
2231         if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
2232                 reddst6.s6_addr16[1] = htons(ifp->if_index);
2233
2234         /* validation */
2235         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2236                 nd6log((LOG_ERR,
2237                         "ICMP6 redirect sent from %s rejected; "
2238                         "must be from linklocal\n", ip6_sprintf(&src6)));
2239                 goto bad;
2240         }
2241         if (ip6->ip6_hlim != 255) {
2242                 nd6log((LOG_ERR,
2243                         "ICMP6 redirect sent from %s rejected; "
2244                         "hlim=%d (must be 255)\n",
2245                         ip6_sprintf(&src6), ip6->ip6_hlim));
2246                 goto bad;
2247         }
2248     {
2249         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2250         struct sockaddr_in6 sin6;
2251         struct in6_addr *gw6;
2252
2253         bzero(&sin6, sizeof(sin6));
2254         sin6.sin6_family = AF_INET6;
2255         sin6.sin6_len = sizeof(struct sockaddr_in6);
2256         bcopy(&reddst6, &sin6.sin6_addr, sizeof reddst6);
2257         rt = rtlookup((struct sockaddr *)&sin6, 0, 0UL);
2258         if (rt) {
2259                 if (rt->rt_gateway == NULL ||
2260                     rt->rt_gateway->sa_family != AF_INET6) {
2261                         nd6log((LOG_ERR,
2262                             "ICMP6 redirect rejected; no route "
2263                             "with inet6 gateway found for redirect dst: %s\n",
2264                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2265                         --rt->rt_refcnt;
2266                         goto bad;
2267                 }
2268
2269                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2270                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2271                         nd6log((LOG_ERR,
2272                                 "ICMP6 redirect rejected; "
2273                                 "not equal to gw-for-src=%s (must be same): "
2274                                 "%s\n",
2275                                 ip6_sprintf(gw6),
2276                                 icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2277                         --rt->rt_refcnt;
2278                         goto bad;
2279                 }
2280         } else {
2281                 nd6log((LOG_ERR,
2282                         "ICMP6 redirect rejected; "
2283                         "no route found for redirect dst: %s\n",
2284                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2285                 goto bad;
2286         }
2287         --rt->rt_refcnt;
2288         rt = NULL;
2289     }
2290         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2291                 nd6log((LOG_ERR,
2292                         "ICMP6 redirect rejected; "
2293                         "redirect dst must be unicast: %s\n",
2294                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2295                 goto bad;
2296         }
2297
2298         is_router = is_onlink = 0;
2299         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2300                 is_router = 1;  /* router case */
2301         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2302                 is_onlink = 1;  /* on-link destination case */
2303         if (!is_router && !is_onlink) {
2304                 nd6log((LOG_ERR,
2305                         "ICMP6 redirect rejected; "
2306                         "neither router case nor onlink case: %s\n",
2307                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2308                 goto bad;
2309         }
2310         /* validation passed */
2311
2312         icmp6len -= sizeof(*nd_rd);
2313         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2314         if (nd6_options(&ndopts) < 0) {
2315                 nd6log((LOG_INFO, "icmp6_redirect_input: "
2316                         "invalid ND option, rejected: %s\n",
2317                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2318                 /* nd6_options have incremented stats */
2319                 goto freeit;
2320         }
2321
2322         if (ndopts.nd_opts_tgt_lladdr) {
2323                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2324                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2325         }
2326
2327         if (ndopts.nd_opts_rh) {
2328                 redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
2329                 redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
2330         }
2331
2332         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2333                 nd6log((LOG_INFO,
2334                         "icmp6_redirect_input: lladdrlen mismatch for %s "
2335                         "(if %d, icmp6 packet %d): %s\n",
2336                         ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
2337                         icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2338                 goto bad;
2339         }
2340
2341         /* RFC 2461 8.3 */
2342         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2343                          is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2344
2345         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2346                 /* perform rtredirect */
2347                 struct sockaddr_in6 sdst;
2348                 struct sockaddr_in6 sgw;
2349                 struct sockaddr_in6 ssrc;
2350
2351                 bzero(&sdst, sizeof(sdst));
2352                 bzero(&sgw, sizeof(sgw));
2353                 bzero(&ssrc, sizeof(ssrc));
2354                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2355                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2356                         sizeof(struct sockaddr_in6);
2357                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2358                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2359                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2360                 rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
2361                            (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
2362                            (struct sockaddr *)&ssrc,
2363                            (struct rtentry **)NULL);
2364         }
2365         /* finally update cached route in each socket via pfctlinput */
2366     {
2367         struct sockaddr_in6 sdst;
2368
2369         bzero(&sdst, sizeof(sdst));
2370         sdst.sin6_family = AF_INET6;
2371         sdst.sin6_len = sizeof(struct sockaddr_in6);
2372         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2373         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2374 #ifdef IPSEC
2375         key_sa_routechange((struct sockaddr *)&sdst);
2376 #endif
2377     }
2378
2379  freeit:
2380         m_freem(m);
2381         return;
2382
2383  bad:
2384         icmp6stat.icp6s_badredirect++;
2385         m_freem(m);
2386 }
2387
2388 void
2389 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2390 {
2391         struct ifnet *ifp;      /* my outgoing interface */
2392         struct in6_addr *ifp_ll6;
2393         struct in6_addr *router_ll6;
2394         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2395         struct mbuf *m = NULL;  /* newly allocated one */
2396         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2397         struct nd_redirect *nd_rd;
2398         size_t maxlen;
2399         u_char *p;
2400         struct ifnet *outif = NULL;
2401         struct sockaddr_in6 src_sa;
2402
2403         icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
2404
2405         /* if we are not router, we don't send icmp6 redirect */
2406         if (!ip6_forwarding || ip6_accept_rtadv)
2407                 goto fail;
2408
2409         /* sanity check */
2410         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2411                 goto fail;
2412
2413         /*
2414          * Address check:
2415          *  the source address must identify a neighbor, and
2416          *  the destination address must not be a multicast address
2417          *  [RFC 2461, sec 8.2]
2418          */
2419         sip6 = mtod(m0, struct ip6_hdr *);
2420         bzero(&src_sa, sizeof(src_sa));
2421         src_sa.sin6_family = AF_INET6;
2422         src_sa.sin6_len = sizeof(src_sa);
2423         src_sa.sin6_addr = sip6->ip6_src;
2424         /* we don't currently use sin6_scope_id, but eventually use it */
2425         src_sa.sin6_scope_id = in6_addr2scopeid(ifp, &sip6->ip6_src);
2426         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2427                 goto fail;
2428         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2429                 goto fail;      /* what should we do here? */
2430
2431         /* rate limit */
2432         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2433                 goto fail;
2434
2435         /*
2436          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2437          * we almost always ask for an mbuf cluster for simplicity.
2438          * (MHLEN < IPV6_MMTU is almost always true)
2439          */
2440 #if IPV6_MMTU >= MCLBYTES
2441 # error assumption failed about IPV6_MMTU and MCLBYTES
2442 #endif
2443         MGETHDR(m, MB_DONTWAIT, MT_HEADER);
2444         if (m && IPV6_MMTU >= MHLEN)
2445                 MCLGET(m, MB_DONTWAIT);
2446         if (!m)
2447                 goto fail;
2448         m->m_pkthdr.rcvif = NULL;
2449         m->m_len = 0;
2450         maxlen = M_TRAILINGSPACE(m);
2451         maxlen = min(IPV6_MMTU, maxlen);
2452         /* just for safety */
2453         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2454             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2455                 goto fail;
2456         }
2457
2458         {
2459                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2460                 struct in6_ifaddr *ia;
2461                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2462                                                  IN6_IFF_NOTREADY|
2463                                                  IN6_IFF_ANYCAST)) == NULL)
2464                         goto fail;
2465                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2466         }
2467
2468         /* get ip6 linklocal address for the router. */
2469         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2470                 struct sockaddr_in6 *sin6;
2471                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2472                 router_ll6 = &sin6->sin6_addr;
2473                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2474                         router_ll6 = (struct in6_addr *)NULL;
2475         } else
2476                 router_ll6 = (struct in6_addr *)NULL;
2477
2478         /* ip6 */
2479         ip6 = mtod(m, struct ip6_hdr *);
2480         ip6->ip6_flow = 0;
2481         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2482         ip6->ip6_vfc |= IPV6_VERSION;
2483         /* ip6->ip6_plen will be set later */
2484         ip6->ip6_nxt = IPPROTO_ICMPV6;
2485         ip6->ip6_hlim = 255;
2486         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2487         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2488         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2489
2490         /* ND Redirect */
2491         nd_rd = (struct nd_redirect *)(ip6 + 1);
2492         nd_rd->nd_rd_type = ND_REDIRECT;
2493         nd_rd->nd_rd_code = 0;
2494         nd_rd->nd_rd_reserved = 0;
2495         if (rt->rt_flags & RTF_GATEWAY) {
2496                 /*
2497                  * nd_rd->nd_rd_target must be a link-local address in
2498                  * better router cases.
2499                  */
2500                 if (!router_ll6)
2501                         goto fail;
2502                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2503                       sizeof(nd_rd->nd_rd_target));
2504                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2505                       sizeof(nd_rd->nd_rd_dst));
2506         } else {
2507                 /* make sure redtgt == reddst */
2508                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2509                       sizeof(nd_rd->nd_rd_target));
2510                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2511                       sizeof(nd_rd->nd_rd_dst));
2512         }
2513
2514         p = (u_char *)(nd_rd + 1);
2515
2516         if (!router_ll6)
2517                 goto nolladdropt;
2518
2519     {
2520         /* target lladdr option */
2521         struct rtentry *rt_router = NULL;
2522         int len;
2523         struct sockaddr_dl *sdl;
2524         struct nd_opt_hdr *nd_opt;
2525         char *lladdr;
2526
2527         rt_router = nd6_lookup(router_ll6, 0, ifp);
2528         if (!rt_router)
2529                 goto nolladdropt;
2530         len = sizeof(*nd_opt) + ifp->if_addrlen;
2531         len = (len + 7) & ~7;   /* round by 8 */
2532         /* safety check */
2533         if (len + (p - (u_char *)ip6) > maxlen)
2534                 goto nolladdropt;
2535         if (!(rt_router->rt_flags & RTF_GATEWAY) &&
2536             (rt_router->rt_flags & RTF_LLINFO) &&
2537             (rt_router->rt_gateway->sa_family == AF_LINK) &&
2538             (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
2539             sdl->sdl_alen) {
2540                 nd_opt = (struct nd_opt_hdr *)p;
2541                 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2542                 nd_opt->nd_opt_len = len >> 3;
2543                 lladdr = (char *)(nd_opt + 1);
2544                 bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
2545                 p += len;
2546         }
2547     }
2548 nolladdropt:;
2549
2550         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2551
2552         /* just to be safe */
2553 #ifdef M_DECRYPTED      /*not openbsd*/
2554         if (m0->m_flags & M_DECRYPTED)
2555                 goto noredhdropt;
2556 #endif
2557         if (p - (u_char *)ip6 > maxlen)
2558                 goto noredhdropt;
2559
2560     {
2561         /* redirected header option */
2562         int len;
2563         struct nd_opt_rd_hdr *nd_opt_rh;
2564
2565         /*
2566          * compute the maximum size for icmp6 redirect header option.
2567          * XXX room for auth header?
2568          */
2569         len = maxlen - (p - (u_char *)ip6);
2570         len &= ~7;
2571
2572         /* This is just for simplicity. */
2573         if (m0->m_pkthdr.len != m0->m_len) {
2574                 if (m0->m_next) {
2575                         m_freem(m0->m_next);
2576                         m0->m_next = NULL;
2577                 }
2578                 m0->m_pkthdr.len = m0->m_len;
2579         }
2580
2581         /*
2582          * Redirected header option spec (RFC2461 4.6.3) talks nothing
2583          * about padding/truncate rule for the original IP packet.
2584          * From the discussion on IPv6imp in Feb 1999, the consensus was:
2585          * - "attach as much as possible" is the goal
2586          * - pad if not aligned (original size can be guessed by original
2587          *   ip6 header)
2588          * Following code adds the padding if it is simple enough,
2589          * and truncates if not.
2590          */
2591         if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2592                 panic("assumption failed in %s:%d", __FILE__, __LINE__);
2593
2594         if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2595                 /* not enough room, truncate */
2596                 m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2597         } else {
2598                 /* enough room, pad or truncate */
2599                 size_t extra;
2600
2601                 extra = m0->m_pkthdr.len % 8;
2602                 if (extra) {
2603                         /* pad if easy enough, truncate if not */
2604                         if (8 - extra <= M_TRAILINGSPACE(m0)) {
2605                                 /* pad */
2606                                 m0->m_len += (8 - extra);
2607                                 m0->m_pkthdr.len += (8 - extra);
2608                         } else {
2609                                 /* truncate */
2610                                 m0->m_pkthdr.len -= extra;
2611                                 m0->m_len -= extra;
2612                         }
2613                 }
2614                 len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2615                 m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
2616         }
2617
2618         nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2619         bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2620         nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2621         nd_opt_rh->nd_opt_rh_len = len >> 3;
2622         p += sizeof(*nd_opt_rh);
2623         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2624
2625         /* connect m0 to m */
2626         m->m_next = m0;
2627         m->m_pkthdr.len = m->m_len + m0->m_len;
2628     }
2629 noredhdropt:;
2630
2631         if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
2632                 sip6->ip6_src.s6_addr16[1] = 0;
2633         if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
2634                 sip6->ip6_dst.s6_addr16[1] = 0;
2635 #if 0
2636         if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
2637                 ip6->ip6_src.s6_addr16[1] = 0;
2638         if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
2639                 ip6->ip6_dst.s6_addr16[1] = 0;
2640 #endif
2641         if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
2642                 nd_rd->nd_rd_target.s6_addr16[1] = 0;
2643         if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
2644                 nd_rd->nd_rd_dst.s6_addr16[1] = 0;
2645
2646         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2647
2648         nd_rd->nd_rd_cksum = 0;
2649         nd_rd->nd_rd_cksum
2650                 = in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
2651
2652         /* send the packet to outside... */
2653         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2654         if (outif) {
2655                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2656                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2657         }
2658         icmp6stat.icp6s_outhist[ND_REDIRECT]++;
2659
2660         return;
2661
2662 fail:
2663         if (m)
2664                 m_freem(m);
2665         if (m0)
2666                 m_freem(m0);
2667 }
2668
2669 #ifdef HAVE_NRL_INPCB
2670 #define sotoin6pcb      sotoinpcb
2671 #define in6pcb          inpcb
2672 #define in6p_icmp6filt  inp_icmp6filt
2673 #endif
2674 /*
2675  * ICMPv6 socket option processing.
2676  */
2677 int
2678 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2679 {
2680         int error = 0;
2681         int optlen;
2682         struct inpcb *inp = sotoinpcb(so);
2683         int level, op, optname;
2684
2685         if (sopt) {
2686                 level = sopt->sopt_level;
2687                 op = sopt->sopt_dir;
2688                 optname = sopt->sopt_name;
2689                 optlen = sopt->sopt_valsize;
2690         } else
2691                 level = op = optname = optlen = 0;
2692
2693         if (level != IPPROTO_ICMPV6) {
2694                 return EINVAL;
2695         }
2696
2697         switch (op) {
2698         case PRCO_SETOPT:
2699                 switch (optname) {
2700                 case ICMP6_FILTER:
2701                     {
2702                         struct icmp6_filter *p;
2703
2704                         if (optlen != sizeof(*p)) {
2705                                 error = EMSGSIZE;
2706                                 break;
2707                         }
2708                         if (inp->in6p_icmp6filt == NULL) {
2709                                 error = EINVAL;
2710                                 break;
2711                         }
2712                         error = sooptcopyin(sopt, inp->in6p_icmp6filt, optlen,
2713                                 optlen);
2714                         break;
2715                     }
2716
2717                 default:
2718                         error = ENOPROTOOPT;
2719                         break;
2720                 }
2721                 break;
2722
2723         case PRCO_GETOPT:
2724                 switch (optname) {
2725                 case ICMP6_FILTER:
2726                     {
2727                         if (inp->in6p_icmp6filt == NULL) {
2728                                 error = EINVAL;
2729                                 break;
2730                         }
2731                         error = sooptcopyout(sopt, inp->in6p_icmp6filt,
2732                                 sizeof(struct icmp6_filter));
2733                         break;
2734                     }
2735
2736                 default:
2737                         error = ENOPROTOOPT;
2738                         break;
2739                 }
2740                 break;
2741         }
2742
2743         return(error);
2744 }
2745 #ifdef HAVE_NRL_INPCB
2746 #undef sotoin6pcb
2747 #undef in6pcb
2748 #undef in6p_icmp6filt
2749 #endif
2750
2751 #ifndef HAVE_PPSRATECHECK
2752 #ifndef timersub
2753 #define timersub(tvp, uvp, vvp)                                         \
2754         do {                                                            \
2755                 (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;          \
2756                 (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;       \
2757                 if ((vvp)->tv_usec < 0) {                               \
2758                         (vvp)->tv_sec--;                                \
2759                         (vvp)->tv_usec += 1000000;                      \
2760                 }                                                       \
2761         } while (0)
2762 #endif
2763
2764 /*
2765  * ppsratecheck(): packets (or events) per second limitation.
2766  */
2767 static int
2768 ppsratecheck(struct timeval *lasttime, int *curpps,
2769              int maxpps)        /* maximum pps allowed */
2770 {
2771         struct timeval tv, delta;
2772         int rv;
2773
2774         microtime(&tv);
2775
2776         timersub(&tv, lasttime, &delta);
2777
2778         /*
2779          * Check for 0,0 so that the message will be seen at least once.
2780          * If more than one second has passed since the last update of
2781          * lasttime, reset the counter.
2782          *
2783          * We do increment *curpps even in *curpps < maxpps case, as some may
2784          * try to use *curpps for stat purposes as well.
2785          */
2786         if ((lasttime->tv_sec == 0 && lasttime->tv_usec == 0) ||
2787             delta.tv_sec >= 1) {
2788                 *lasttime = tv;
2789                 *curpps = 0;
2790                 rv = 1;
2791         } else if (maxpps < 0)
2792                 rv = 1;
2793         else if (*curpps < maxpps)
2794                 rv = 1;
2795         else
2796                 rv = 0;
2797
2798 #if 1 /* DIAGNOSTIC? */
2799         /* be careful about wrap-around */
2800         if (*curpps + 1 > *curpps)
2801                 *curpps = *curpps + 1;
2802 #else
2803         /*
2804          * assume that there's not too many calls to this function.
2805          * not sure if the assumption holds, as it depends on *caller's*
2806          * behavior, not the behavior of this function.
2807          * IMHO it is wrong to make assumption on the caller's behavior,
2808          * so the above #if is #if 1, not #ifdef DIAGNOSTIC.
2809          */
2810         *curpps = *curpps + 1;
2811 #endif
2812
2813         return (rv);
2814 }
2815 #endif
2816
2817 /*
2818  * Perform rate limit check.
2819  * Returns 0 if it is okay to send the icmp6 packet.
2820  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2821  * limitation.
2822  *
2823  * XXX per-destination/type check necessary?
2824  */
2825 static int
2826 icmp6_ratelimit(const struct in6_addr *dst,     /* not used at this moment */
2827                 const int type,                 /* not used at this moment */
2828                 const int code)                 /* not used at this moment */
2829 {
2830         int ret;
2831
2832         ret = 0;        /* okay to send */
2833
2834         /* PPS limit */
2835         if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
2836             icmp6errppslim)) {
2837                 /* The packet is subject to rate limit */
2838                 ret++;
2839         }
2840
2841         return ret;
2842 }