sys/netinet6/icmp6.c

   1 /*-
   2  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the project nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  *      $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
  30  */
  31
  32 /*-
  33  * Copyright (c) 1982, 1986, 1988, 1993
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * Redistribution and use in source and binary forms, with or without
  37  * modification, are permitted provided that the following conditions
  38  * are met:
  39  * 1. Redistributions of source code must retain the above copyright
  40  *    notice, this list of conditions and the following disclaimer.
  41  * 2. Redistributions in binary form must reproduce the above copyright
  42  *    notice, this list of conditions and the following disclaimer in the
  43  *    documentation and/or other materials provided with the distribution.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      @(#)ip_icmp.c   8.2 (Berkeley) 1/4/94
  61  */
  62
  63 #include <sys/cdefs.h>
  64 __FBSDID("$FreeBSD$");
  65
  66 #include "opt_inet.h"
  67 #include "opt_inet6.h"
  68 #include "opt_ipsec.h"
  69
  70 #include <sys/param.h>
  71 #include <sys/domain.h>
  72 #include <sys/jail.h>
  73 #include <sys/kernel.h>
  74 #include <sys/lock.h>
  75 #include <sys/malloc.h>
  76 #include <sys/mbuf.h>
  77 #include <sys/proc.h>
  78 #include <sys/protosw.h>
  79 #include <sys/signalvar.h>
  80 #include <sys/socket.h>
  81 #include <sys/socketvar.h>
  82 #include <sys/sx.h>
  83 #include <sys/syslog.h>
  84 #include <sys/systm.h>
  85 #include <sys/time.h>
  86
  87 #include <net/if.h>
  88 #include <net/if_dl.h>
  89 #include <net/if_llatbl.h>
  90 #include <net/if_types.h>
  91 #include <net/route.h>
  92 #include <net/vnet.h>
  93
  94 #include <netinet/in.h>
  95 #include <netinet/in_pcb.h>
  96 #include <netinet/in_var.h>
  97 #include <netinet/ip6.h>
  98 #include <netinet/icmp6.h>
  99 #include <netinet/tcp_var.h>
 100
 101 #include <netinet6/in6_ifattach.h>
 102 #include <netinet6/in6_pcb.h>
 103 #include <netinet6/ip6protosw.h>
 104 #include <netinet6/ip6_var.h>
 105 #include <netinet6/scope6_var.h>
 106 #include <netinet6/mld6_var.h>
 107 #include <netinet6/nd6.h>
 108 #include <netinet6/send.h>
 109
 110 #ifdef IPSEC
 111 #include <netipsec/ipsec.h>
 112 #include <netipsec/key.h>
 113 #endif
 114
 115 extern struct domain inet6domain;
 116
 117 VNET_PCPUSTAT_DEFINE(struct icmp6stat, icmp6stat);
 118 VNET_PCPUSTAT_SYSINIT(icmp6stat);
 119
 120 #ifdef VIMAGE
 121 VNET_PCPUSTAT_SYSUNINIT(icmp6stat);
 122 #endif /* VIMAGE */
 123
 124 VNET_DECLARE(struct inpcbinfo, ripcbinfo);
 125 VNET_DECLARE(struct inpcbhead, ripcb);
 126 VNET_DECLARE(int, icmp6errppslim);
 127 static VNET_DEFINE(int, icmp6errpps_count) = 0;
 128 static VNET_DEFINE(struct timeval, icmp6errppslim_last);
 129 VNET_DECLARE(int, icmp6_nodeinfo);
 130
 131 #define V_ripcbinfo                     VNET(ripcbinfo)
 132 #define V_ripcb                         VNET(ripcb)
 133 #define V_icmp6errppslim                VNET(icmp6errppslim)
 134 #define V_icmp6errpps_count             VNET(icmp6errpps_count)
 135 #define V_icmp6errppslim_last           VNET(icmp6errppslim_last)
 136 #define V_icmp6_nodeinfo                VNET(icmp6_nodeinfo)
 137
 138 static void icmp6_errcount(int, int);
 139 static int icmp6_rip6_input(struct mbuf **, int);
 140 static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
 141 static const char *icmp6_redirect_diag(struct in6_addr *,
 142         struct in6_addr *, struct in6_addr *);
 143 static struct mbuf *ni6_input(struct mbuf *, int);
 144 static struct mbuf *ni6_nametodns(const char *, int, int);
 145 static int ni6_dnsmatch(const char *, int, const char *, int);
 146 static int ni6_addrs(struct icmp6_nodeinfo *, struct mbuf *,
 147                           struct ifnet **, struct in6_addr *);
 148 static int ni6_store_addrs(struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
 149                                 struct ifnet *, int);
 150 static int icmp6_notify_error(struct mbuf **, int, int, int);
 151
 152 /*
 153  * Kernel module interface for updating icmp6stat.  The argument is an index
 154  * into icmp6stat treated as an array of u_quad_t.  While this encodes the
 155  * general layout of icmp6stat into the caller, it doesn't encode its
 156  * location, so that future changes to add, for example, per-CPU stats
 157  * support won't cause binary compatibility problems for kernel modules.
 158  */
 159 void
 160 kmod_icmp6stat_inc(int statnum)
 161 {
 162
 163         counter_u64_add(VNET(icmp6stat)[statnum], 1);
 164 }
 165
 166 static void
 167 icmp6_errcount(int type, int code)
 168 {
 169         switch (type) {
 170         case ICMP6_DST_UNREACH:
 171                 switch (code) {
 172                 case ICMP6_DST_UNREACH_NOROUTE:
 173                         ICMP6STAT_INC(icp6s_odst_unreach_noroute);
 174                         return;
 175                 case ICMP6_DST_UNREACH_ADMIN:
 176                         ICMP6STAT_INC(icp6s_odst_unreach_admin);
 177                         return;
 178                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 179                         ICMP6STAT_INC(icp6s_odst_unreach_beyondscope);
 180                         return;
 181                 case ICMP6_DST_UNREACH_ADDR:
 182                         ICMP6STAT_INC(icp6s_odst_unreach_addr);
 183                         return;
 184                 case ICMP6_DST_UNREACH_NOPORT:
 185                         ICMP6STAT_INC(icp6s_odst_unreach_noport);
 186                         return;
 187                 }
 188                 break;
 189         case ICMP6_PACKET_TOO_BIG:
 190                 ICMP6STAT_INC(icp6s_opacket_too_big);
 191                 return;
 192         case ICMP6_TIME_EXCEEDED:
 193                 switch (code) {
 194                 case ICMP6_TIME_EXCEED_TRANSIT:
 195                         ICMP6STAT_INC(icp6s_otime_exceed_transit);
 196                         return;
 197                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 198                         ICMP6STAT_INC(icp6s_otime_exceed_reassembly);
 199                         return;
 200                 }
 201                 break;
 202         case ICMP6_PARAM_PROB:
 203                 switch (code) {
 204                 case ICMP6_PARAMPROB_HEADER:
 205                         ICMP6STAT_INC(icp6s_oparamprob_header);
 206                         return;
 207                 case ICMP6_PARAMPROB_NEXTHEADER:
 208                         ICMP6STAT_INC(icp6s_oparamprob_nextheader);
 209                         return;
 210                 case ICMP6_PARAMPROB_OPTION:
 211                         ICMP6STAT_INC(icp6s_oparamprob_option);
 212                         return;
 213                 }
 214                 break;
 215         case ND_REDIRECT:
 216                 ICMP6STAT_INC(icp6s_oredirect);
 217                 return;
 218         }
 219         ICMP6STAT_INC(icp6s_ounknown);
 220 }
 221
 222 /*
 223  * A wrapper function for icmp6_error() necessary when the erroneous packet
 224  * may not contain enough scope zone information.
 225  */
 226 void
 227 icmp6_error2(struct mbuf *m, int type, int code, int param,
 228     struct ifnet *ifp)
 229 {
 230         struct ip6_hdr *ip6;
 231
 232         if (ifp == NULL)
 233                 return;
 234
 235 #ifndef PULLDOWN_TEST
 236         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 237 #else
 238         if (m->m_len < sizeof(struct ip6_hdr)) {
 239                 m = m_pullup(m, sizeof(struct ip6_hdr));
 240                 if (m == NULL)
 241                         return;
 242         }
 243 #endif
 244
 245         ip6 = mtod(m, struct ip6_hdr *);
 246
 247         if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
 248                 return;
 249         if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
 250                 return;
 251
 252         icmp6_error(m, type, code, param);
 253 }
 254
 255 /*
 256  * Generate an error packet of type error in response to bad IP6 packet.
 257  */
 258 void
 259 icmp6_error(struct mbuf *m, int type, int code, int param)
 260 {
 261         struct ip6_hdr *oip6, *nip6;
 262         struct icmp6_hdr *icmp6;
 263         u_int preplen;
 264         int off;
 265         int nxt;
 266
 267         ICMP6STAT_INC(icp6s_error);
 268
 269         /* count per-type-code statistics */
 270         icmp6_errcount(type, code);
 271
 272 #ifdef M_DECRYPTED      /*not openbsd*/
 273         if (m->m_flags & M_DECRYPTED) {
 274                 ICMP6STAT_INC(icp6s_canterror);
 275                 goto freeit;
 276         }
 277 #endif
 278
 279 #ifndef PULLDOWN_TEST
 280         IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
 281 #else
 282         if (m->m_len < sizeof(struct ip6_hdr)) {
 283                 m = m_pullup(m, sizeof(struct ip6_hdr));
 284                 if (m == NULL)
 285                         return;
 286         }
 287 #endif
 288         oip6 = mtod(m, struct ip6_hdr *);
 289
 290         /*
 291          * If the destination address of the erroneous packet is a multicast
 292          * address, or the packet was sent using link-layer multicast,
 293          * we should basically suppress sending an error (RFC 2463, Section
 294          * 2.4).
 295          * We have two exceptions (the item e.2 in that section):
 296          * - the Packet Too Big message can be sent for path MTU discovery.
 297          * - the Parameter Problem Message that can be allowed an icmp6 error
 298          *   in the option type field.  This check has been done in
 299          *   ip6_unknown_opt(), so we can just check the type and code.
 300          */
 301         if ((m->m_flags & (M_BCAST|M_MCAST) ||
 302              IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
 303             (type != ICMP6_PACKET_TOO_BIG &&
 304              (type != ICMP6_PARAM_PROB ||
 305               code != ICMP6_PARAMPROB_OPTION)))
 306                 goto freeit;
 307
 308         /*
 309          * RFC 2463, 2.4 (e.5): source address check.
 310          * XXX: the case of anycast source?
 311          */
 312         if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
 313             IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
 314                 goto freeit;
 315
 316         /*
 317          * If we are about to send ICMPv6 against ICMPv6 error/redirect,
 318          * don't do it.
 319          */
 320         nxt = -1;
 321         off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
 322         if (off >= 0 && nxt == IPPROTO_ICMPV6) {
 323                 struct icmp6_hdr *icp;
 324
 325 #ifndef PULLDOWN_TEST
 326                 IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
 327                 icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 328 #else
 329                 IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
 330                         sizeof(*icp));
 331                 if (icp == NULL) {
 332                         ICMP6STAT_INC(icp6s_tooshort);
 333                         return;
 334                 }
 335 #endif
 336                 if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
 337                     icp->icmp6_type == ND_REDIRECT) {
 338                         /*
 339                          * ICMPv6 error
 340                          * Special case: for redirect (which is
 341                          * informational) we must not send icmp6 error.
 342                          */
 343                         ICMP6STAT_INC(icp6s_canterror);
 344                         goto freeit;
 345                 } else {
 346                         /* ICMPv6 informational - send the error */
 347                 }
 348         } else {
 349                 /* non-ICMPv6 - send the error */
 350         }
 351
 352         oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 353
 354         /* Finally, do rate limitation check. */
 355         if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
 356                 ICMP6STAT_INC(icp6s_toofreq);
 357                 goto freeit;
 358         }
 359
 360         /*
 361          * OK, ICMP6 can be generated.
 362          */
 363
 364         if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
 365                 m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
 366
 367         preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
 368         M_PREPEND(m, preplen, M_NOWAIT);        /* FIB is also copied over. */
 369         if (m && m->m_len < preplen)
 370                 m = m_pullup(m, preplen);
 371         if (m == NULL) {
 372                 nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
 373                 return;
 374         }
 375
 376         nip6 = mtod(m, struct ip6_hdr *);
 377         nip6->ip6_src  = oip6->ip6_src;
 378         nip6->ip6_dst  = oip6->ip6_dst;
 379
 380         in6_clearscope(&oip6->ip6_src);
 381         in6_clearscope(&oip6->ip6_dst);
 382
 383         icmp6 = (struct icmp6_hdr *)(nip6 + 1);
 384         icmp6->icmp6_type = type;
 385         icmp6->icmp6_code = code;
 386         icmp6->icmp6_pptr = htonl((u_int32_t)param);
 387
 388         /*
 389          * icmp6_reflect() is designed to be in the input path.
 390          * icmp6_error() can be called from both input and output path,
 391          * and if we are in output path rcvif could contain bogus value.
 392          * clear m->m_pkthdr.rcvif for safety, we should have enough scope
 393          * information in ip header (nip6).
 394          */
 395         m->m_pkthdr.rcvif = NULL;
 396
 397         ICMP6STAT_INC(icp6s_outhist[type]);
 398         icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
 399
 400         return;
 401
 402   freeit:
 403         /*
 404          * If we can't tell whether or not we can generate ICMP6, free it.
 405          */
 406         m_freem(m);
 407 }
 408
 409 /*
 410  * Process a received ICMP6 message.
 411  */
 412 int
 413 icmp6_input(struct mbuf **mp, int *offp, int proto)
 414 {
 415         struct mbuf *m = *mp, *n;
 416         struct ifnet *ifp;
 417         struct ip6_hdr *ip6, *nip6;
 418         struct icmp6_hdr *icmp6, *nicmp6;
 419         int off = *offp;
 420         int icmp6len = m->m_pkthdr.len - *offp;
 421         int code, sum, noff;
 422         char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
 423         int ip6len, error;
 424
 425         ifp = m->m_pkthdr.rcvif;
 426
 427 #ifndef PULLDOWN_TEST
 428         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
 429         /* m might change if M_LOOP.  So, call mtod after this */
 430 #endif
 431
 432         /*
 433          * Locate icmp6 structure in mbuf, and check
 434          * that not corrupted and of at least minimum length
 435          */
 436
 437         ip6 = mtod(m, struct ip6_hdr *);
 438         ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
 439         if (icmp6len < sizeof(struct icmp6_hdr)) {
 440                 ICMP6STAT_INC(icp6s_tooshort);
 441                 goto freeit;
 442         }
 443
 444         /*
 445          * Check multicast group membership.
 446          * Note: SSM filters are not applied for ICMPv6 traffic.
 447          */
 448         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
 449                 struct in6_multi        *inm;
 450
 451                 inm = in6m_lookup(ifp, &ip6->ip6_dst);
 452                 if (inm == NULL) {
 453                         IP6STAT_INC(ip6s_notmember);
 454                         in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
 455                         goto freeit;
 456                 }
 457         }
 458
 459         /*
 460          * calculate the checksum
 461          */
 462 #ifndef PULLDOWN_TEST
 463         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
 464 #else
 465         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
 466         if (icmp6 == NULL) {
 467                 ICMP6STAT_INC(icp6s_tooshort);
 468                 return IPPROTO_DONE;
 469         }
 470 #endif
 471         code = icmp6->icmp6_code;
 472
 473         if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
 474                 nd6log((LOG_ERR,
 475                     "ICMP6 checksum error(%d|%x) %s\n",
 476                     icmp6->icmp6_type, sum,
 477                     ip6_sprintf(ip6bufs, &ip6->ip6_src)));
 478                 ICMP6STAT_INC(icp6s_checksum);
 479                 goto freeit;
 480         }
 481
 482         if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
 483                 /*
 484                  * Deliver very specific ICMP6 type only.
 485                  * This is important to deliver TOOBIG.  Otherwise PMTUD
 486                  * will not work.
 487                  */
 488                 switch (icmp6->icmp6_type) {
 489                 case ICMP6_DST_UNREACH:
 490                 case ICMP6_PACKET_TOO_BIG:
 491                 case ICMP6_TIME_EXCEEDED:
 492                         break;
 493                 default:
 494                         goto freeit;
 495                 }
 496         }
 497
 498         ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
 499         icmp6_ifstat_inc(ifp, ifs6_in_msg);
 500         if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
 501                 icmp6_ifstat_inc(ifp, ifs6_in_error);
 502
 503         switch (icmp6->icmp6_type) {
 504         case ICMP6_DST_UNREACH:
 505                 icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
 506                 switch (code) {
 507                 case ICMP6_DST_UNREACH_NOROUTE:
 508                         code = PRC_UNREACH_NET;
 509                         break;
 510                 case ICMP6_DST_UNREACH_ADMIN:
 511                         icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
 512                         code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
 513                         break;
 514                 case ICMP6_DST_UNREACH_ADDR:
 515                         code = PRC_HOSTDEAD;
 516                         break;
 517                 case ICMP6_DST_UNREACH_BEYONDSCOPE:
 518                         /* I mean "source address was incorrect." */
 519                         code = PRC_PARAMPROB;
 520                         break;
 521                 case ICMP6_DST_UNREACH_NOPORT:
 522                         code = PRC_UNREACH_PORT;
 523                         break;
 524                 default:
 525                         goto badcode;
 526                 }
 527                 goto deliver;
 528                 break;
 529
 530         case ICMP6_PACKET_TOO_BIG:
 531                 icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);
 532
 533                 /* validation is made in icmp6_mtudisc_update */
 534
 535                 code = PRC_MSGSIZE;
 536
 537                 /*
 538                  * Updating the path MTU will be done after examining
 539                  * intermediate extension headers.
 540                  */
 541                 goto deliver;
 542                 break;
 543
 544         case ICMP6_TIME_EXCEEDED:
 545                 icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
 546                 switch (code) {
 547                 case ICMP6_TIME_EXCEED_TRANSIT:
 548                         code = PRC_TIMXCEED_INTRANS;
 549                         break;
 550                 case ICMP6_TIME_EXCEED_REASSEMBLY:
 551                         code = PRC_TIMXCEED_REASS;
 552                         break;
 553                 default:
 554                         goto badcode;
 555                 }
 556                 goto deliver;
 557                 break;
 558
 559         case ICMP6_PARAM_PROB:
 560                 icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
 561                 switch (code) {
 562                 case ICMP6_PARAMPROB_NEXTHEADER:
 563                         code = PRC_UNREACH_PROTOCOL;
 564                         break;
 565                 case ICMP6_PARAMPROB_HEADER:
 566                 case ICMP6_PARAMPROB_OPTION:
 567                         code = PRC_PARAMPROB;
 568                         break;
 569                 default:
 570                         goto badcode;
 571                 }
 572                 goto deliver;
 573                 break;
 574
 575         case ICMP6_ECHO_REQUEST:
 576                 icmp6_ifstat_inc(ifp, ifs6_in_echo);
 577                 if (code != 0)
 578                         goto badcode;
 579                 if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
 580                         /* Give up remote */
 581                         break;
 582                 }
 583                 if ((n->m_flags & M_EXT) != 0
 584                  || n->m_len < off + sizeof(struct icmp6_hdr)) {
 585                         struct mbuf *n0 = n;
 586                         int n0len;
 587
 588                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) <= MHLEN);
 589                         n = m_gethdr(M_NOWAIT, n0->m_type);
 590                         if (n == NULL) {
 591                                 /* Give up remote */
 592                                 m_freem(n0);
 593                                 break;
 594                         }
 595
 596                         m_move_pkthdr(n, n0);   /* FIB copied. */
 597                         n0len = n0->m_pkthdr.len;       /* save for use below */
 598                         /*
 599                          * Copy IPv6 and ICMPv6 only.
 600                          */
 601                         nip6 = mtod(n, struct ip6_hdr *);
 602                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 603                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 604                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 605                         noff = sizeof(struct ip6_hdr);
 606                         /* new mbuf contains only ipv6+icmpv6 headers */
 607                         n->m_len = noff + sizeof(struct icmp6_hdr);
 608                         /*
 609                          * Adjust mbuf.  ip6_plen will be adjusted in
 610                          * ip6_output().
 611                          */
 612                         m_adj(n0, off + sizeof(struct icmp6_hdr));
 613                         /* recalculate complete packet size */
 614                         n->m_pkthdr.len = n0len + (noff - off);
 615                         n->m_next = n0;
 616                 } else {
 617                         nip6 = mtod(n, struct ip6_hdr *);
 618                         IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
 619                             sizeof(*nicmp6));
 620                         noff = off;
 621                 }
 622                 nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
 623                 nicmp6->icmp6_code = 0;
 624                 if (n) {
 625                         ICMP6STAT_INC(icp6s_reflect);
 626                         ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
 627                         icmp6_reflect(n, noff);
 628                 }
 629                 break;
 630
 631         case ICMP6_ECHO_REPLY:
 632                 icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
 633                 if (code != 0)
 634                         goto badcode;
 635                 break;
 636
 637         case MLD_LISTENER_QUERY:
 638         case MLD_LISTENER_REPORT:
 639         case MLD_LISTENER_DONE:
 640         case MLDV2_LISTENER_REPORT:
 641                 /*
 642                  * Drop MLD traffic which is not link-local, has a hop limit
 643                  * of greater than 1 hop, or which does not have the
 644                  * IPv6 HBH Router Alert option.
 645                  * As IPv6 HBH options are stripped in ip6_input() we must
 646                  * check an mbuf header flag.
 647                  * XXX Should we also sanity check that these messages
 648                  * were directed to a link-local multicast prefix?
 649                  */
 650                 if ((ip6->ip6_hlim != 1) || (m->m_flags & M_RTALERT_MLD) == 0)
 651                         goto freeit;
 652                 if (mld_input(m, off, icmp6len) != 0)
 653                         return (IPPROTO_DONE);
 654                 /* m stays. */
 655                 break;
 656
 657         case ICMP6_WRUREQUEST:  /* ICMP6_FQDN_QUERY */
 658             {
 659                 enum { WRU, FQDN } mode;
 660
 661                 if (!V_icmp6_nodeinfo)
 662                         break;
 663
 664                 if (icmp6len == sizeof(struct icmp6_hdr) + 4)
 665                         mode = WRU;
 666                 else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
 667                         mode = FQDN;
 668                 else
 669                         goto badlen;
 670
 671                 if (mode == FQDN) {
 672 #ifndef PULLDOWN_TEST
 673                         IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
 674                             IPPROTO_DONE);
 675 #endif
 676                         n = m_copy(m, 0, M_COPYALL);
 677                         if (n)
 678                                 n = ni6_input(n, off);
 679                         /* XXX meaningless if n == NULL */
 680                         noff = sizeof(struct ip6_hdr);
 681                 } else {
 682                         struct prison *pr;
 683                         u_char *p;
 684                         int maxhlen, hlen;
 685
 686                         /*
 687                          * XXX: this combination of flags is pointless,
 688                          * but should we keep this for compatibility?
 689                          */
 690                         if ((V_icmp6_nodeinfo & 5) != 5)
 691                                 break;
 692
 693                         if (code != 0)
 694                                 goto badcode;
 695
 696                         CTASSERT(sizeof(*nip6) + sizeof(*nicmp6) + 4 <= MHLEN);
 697                         n = m_gethdr(M_NOWAIT, m->m_type);
 698                         if (n == NULL) {
 699                                 /* Give up remote */
 700                                 break;
 701                         }
 702                         if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
 703                                 /*
 704                                  * Previous code did a blind M_COPY_PKTHDR
 705                                  * and said "just for rcvif".  If true, then
 706                                  * we could tolerate the dup failing (due to
 707                                  * the deep copy of the tag chain).  For now
 708                                  * be conservative and just fail.
 709                                  */
 710                                 m_free(n);
 711                                 n = NULL;
 712                         }
 713                         maxhlen = M_TRAILINGSPACE(n) -
 714                             (sizeof(*nip6) + sizeof(*nicmp6) + 4);
 715                         pr = curthread->td_ucred->cr_prison;
 716                         mtx_lock(&pr->pr_mtx);
 717                         hlen = strlen(pr->pr_hostname);
 718                         if (maxhlen > hlen)
 719                                 maxhlen = hlen;
 720                         /*
 721                          * Copy IPv6 and ICMPv6 only.
 722                          */
 723                         nip6 = mtod(n, struct ip6_hdr *);
 724                         bcopy(ip6, nip6, sizeof(struct ip6_hdr));
 725                         nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
 726                         bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
 727                         p = (u_char *)(nicmp6 + 1);
 728                         bzero(p, 4);
 729                         /* meaningless TTL */
 730                         bcopy(pr->pr_hostname, p + 4, maxhlen);
 731                         mtx_unlock(&pr->pr_mtx);
 732                         noff = sizeof(struct ip6_hdr);
 733                         n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
 734                                 sizeof(struct icmp6_hdr) + 4 + maxhlen;
 735                         nicmp6->icmp6_type = ICMP6_WRUREPLY;
 736                         nicmp6->icmp6_code = 0;
 737                 }
 738                 if (n) {
 739                         ICMP6STAT_INC(icp6s_reflect);
 740                         ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
 741                         icmp6_reflect(n, noff);
 742                 }
 743                 break;
 744             }
 745
 746         case ICMP6_WRUREPLY:
 747                 if (code != 0)
 748                         goto badcode;
 749                 break;
 750
 751         case ND_ROUTER_SOLICIT:
 752                 icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
 753                 if (code != 0)
 754                         goto badcode;
 755                 if (icmp6len < sizeof(struct nd_router_solicit))
 756                         goto badlen;
 757                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 758                         /* give up local */
 759
 760                         /* Send incoming SeND packet to user space. */
 761                         if (send_sendso_input_hook != NULL) {
 762                                 IP6_EXTHDR_CHECK(m, off,
 763                                     icmp6len, IPPROTO_DONE);
 764                                 error = send_sendso_input_hook(m, ifp,
 765                                     SND_IN, ip6len);
 766                                 /* -1 == no app on SEND socket */
 767                                 if (error == 0)
 768                                         return (IPPROTO_DONE);
 769                                 nd6_rs_input(m, off, icmp6len);
 770                         } else
 771                                 nd6_rs_input(m, off, icmp6len);
 772                         m = NULL;
 773                         goto freeit;
 774                 }
 775                 if (send_sendso_input_hook != NULL) {
 776                         IP6_EXTHDR_CHECK(n, off,
 777                             icmp6len, IPPROTO_DONE);
 778                         error = send_sendso_input_hook(n, ifp,
 779                             SND_IN, ip6len);
 780                         if (error == 0)
 781                                 goto freeit;
 782                         /* -1 == no app on SEND socket */
 783                         nd6_rs_input(n, off, icmp6len);
 784                 } else
 785                         nd6_rs_input(n, off, icmp6len);
 786                 /* m stays. */
 787                 break;
 788
 789         case ND_ROUTER_ADVERT:
 790                 icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
 791                 if (code != 0)
 792                         goto badcode;
 793                 if (icmp6len < sizeof(struct nd_router_advert))
 794                         goto badlen;
 795                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 796
 797                         /* Send incoming SeND-protected/ND packet to user space. */
 798                         if (send_sendso_input_hook != NULL) {
 799                                 error = send_sendso_input_hook(m, ifp,
 800                                     SND_IN, ip6len);
 801                                 if (error == 0)
 802                                         return (IPPROTO_DONE);
 803                                 nd6_ra_input(m, off, icmp6len);
 804                         } else
 805                                 nd6_ra_input(m, off, icmp6len);
 806                         m = NULL;
 807                         goto freeit;
 808                 }
 809                 if (send_sendso_input_hook != NULL) {
 810                         error = send_sendso_input_hook(n, ifp,
 811                             SND_IN, ip6len);
 812                         if (error == 0)
 813                                 goto freeit;
 814                         nd6_ra_input(n, off, icmp6len);
 815                 } else
 816                         nd6_ra_input(n, off, icmp6len);
 817                 /* m stays. */
 818                 break;
 819
 820         case ND_NEIGHBOR_SOLICIT:
 821                 icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
 822                 if (code != 0)
 823                         goto badcode;
 824                 if (icmp6len < sizeof(struct nd_neighbor_solicit))
 825                         goto badlen;
 826                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 827                         if (send_sendso_input_hook != NULL) {
 828                                 error = send_sendso_input_hook(m, ifp,
 829                                     SND_IN, ip6len);
 830                                 if (error == 0)
 831                                         return (IPPROTO_DONE);
 832                                 nd6_ns_input(m, off, icmp6len);
 833                         } else
 834                                 nd6_ns_input(m, off, icmp6len);
 835                         m = NULL;
 836                         goto freeit;
 837                 }
 838                 if (send_sendso_input_hook != NULL) {
 839                         error = send_sendso_input_hook(n, ifp,
 840                             SND_IN, ip6len);
 841                         if (error == 0)
 842                                 goto freeit;
 843                         nd6_ns_input(n, off, icmp6len);
 844                 } else
 845                         nd6_ns_input(n, off, icmp6len);
 846                 /* m stays. */
 847                 break;
 848
 849         case ND_NEIGHBOR_ADVERT:
 850                 icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
 851                 if (code != 0)
 852                         goto badcode;
 853                 if (icmp6len < sizeof(struct nd_neighbor_advert))
 854                         goto badlen;
 855                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 856
 857                         /* Send incoming SeND-protected/ND packet to user space. */
 858                         if (send_sendso_input_hook != NULL) {
 859                                 error = send_sendso_input_hook(m, ifp,
 860                                     SND_IN, ip6len);
 861                                 if (error == 0)
 862                                         return (IPPROTO_DONE);
 863                                 nd6_na_input(m, off, icmp6len);
 864                         } else
 865                                 nd6_na_input(m, off, icmp6len);
 866                         m = NULL;
 867                         goto freeit;
 868                 }
 869                 if (send_sendso_input_hook != NULL) {
 870                         error = send_sendso_input_hook(n, ifp,
 871                             SND_IN, ip6len);
 872                         if (error == 0)
 873                                 goto freeit;
 874                         nd6_na_input(n, off, icmp6len);
 875                 } else
 876                         nd6_na_input(n, off, icmp6len);
 877                 /* m stays. */
 878                 break;
 879
 880         case ND_REDIRECT:
 881                 icmp6_ifstat_inc(ifp, ifs6_in_redirect);
 882                 if (code != 0)
 883                         goto badcode;
 884                 if (icmp6len < sizeof(struct nd_redirect))
 885                         goto badlen;
 886                 if ((n = m_copym(m, 0, M_COPYALL, M_NOWAIT)) == NULL) {
 887                         if (send_sendso_input_hook != NULL) {
 888                                 error = send_sendso_input_hook(m, ifp,
 889                                     SND_IN, ip6len);
 890                                 if (error == 0)
 891                                         return (IPPROTO_DONE);
 892                             icmp6_redirect_input(m, off);
 893                         } else
 894                                 icmp6_redirect_input(m, off);
 895                         m = NULL;
 896                         goto freeit;
 897                 }
 898                 if (send_sendso_input_hook != NULL) {
 899                         error = send_sendso_input_hook(n, ifp,
 900                             SND_IN, ip6len);
 901                         if (error == 0)
 902                                 goto freeit;
 903                         icmp6_redirect_input(n, off);
 904                 } else
 905                         icmp6_redirect_input(n, off);
 906                 /* m stays. */
 907                 break;
 908
 909         case ICMP6_ROUTER_RENUMBERING:
 910                 if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
 911                     code != ICMP6_ROUTER_RENUMBERING_RESULT)
 912                         goto badcode;
 913                 if (icmp6len < sizeof(struct icmp6_router_renum))
 914                         goto badlen;
 915                 break;
 916
 917         default:
 918                 nd6log((LOG_DEBUG,
 919                     "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
 920                     icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
 921                     ip6_sprintf(ip6bufd, &ip6->ip6_dst),
 922                     ifp ? ifp->if_index : 0));
 923                 if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
 924                         /* ICMPv6 error: MUST deliver it by spec... */
 925                         code = PRC_NCMDS;
 926                         /* deliver */
 927                 } else {
 928                         /* ICMPv6 informational: MUST not deliver */
 929                         break;
 930                 }
 931         deliver:
 932                 if (icmp6_notify_error(&m, off, icmp6len, code) != 0) {
 933                         /* In this case, m should've been freed. */
 934                         return (IPPROTO_DONE);
 935                 }
 936                 break;
 937
 938         badcode:
 939                 ICMP6STAT_INC(icp6s_badcode);
 940                 break;
 941
 942         badlen:
 943                 ICMP6STAT_INC(icp6s_badlen);
 944                 break;
 945         }
 946
 947         /* deliver the packet to appropriate sockets */
 948         icmp6_rip6_input(&m, *offp);
 949
 950         return IPPROTO_DONE;
 951
 952  freeit:
 953         m_freem(m);
 954         return IPPROTO_DONE;
 955 }
 956
 957 static int
 958 icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
 959 {
 960         struct mbuf *m = *mp;
 961         struct icmp6_hdr *icmp6;
 962         struct ip6_hdr *eip6;
 963         u_int32_t notifymtu;
 964         struct sockaddr_in6 icmp6src, icmp6dst;
 965
 966         if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
 967                 ICMP6STAT_INC(icp6s_tooshort);
 968                 goto freeit;
 969         }
 970 #ifndef PULLDOWN_TEST
 971         IP6_EXTHDR_CHECK(m, off,
 972             sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
 973         icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 974 #else
 975         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
 976             sizeof(*icmp6) + sizeof(struct ip6_hdr));
 977         if (icmp6 == NULL) {
 978                 ICMP6STAT_INC(icp6s_tooshort);
 979                 return (-1);
 980         }
 981 #endif
 982         eip6 = (struct ip6_hdr *)(icmp6 + 1);
 983
 984         /* Detect the upper level protocol */
 985         {
 986                 void (*ctlfunc)(int, struct sockaddr *, void *);
 987                 u_int8_t nxt = eip6->ip6_nxt;
 988                 int eoff = off + sizeof(struct icmp6_hdr) +
 989                     sizeof(struct ip6_hdr);
 990                 struct ip6ctlparam ip6cp;
 991                 struct in6_addr *finaldst = NULL;
 992                 int icmp6type = icmp6->icmp6_type;
 993                 struct ip6_frag *fh;
 994                 struct ip6_rthdr *rth;
 995                 struct ip6_rthdr0 *rth0;
 996                 int rthlen;
 997
 998                 while (1) { /* XXX: should avoid infinite loop explicitly? */
 999                         struct ip6_ext *eh;
1000
1001                         switch (nxt) {
1002                         case IPPROTO_HOPOPTS:
1003                         case IPPROTO_DSTOPTS:
1004                         case IPPROTO_AH:
1005 #ifndef PULLDOWN_TEST
1006                                 IP6_EXTHDR_CHECK(m, 0,
1007                                     eoff + sizeof(struct ip6_ext), -1);
1008                                 eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
1009 #else
1010                                 IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
1011                                     eoff, sizeof(*eh));
1012                                 if (eh == NULL) {
1013                                         ICMP6STAT_INC(icp6s_tooshort);
1014                                         return (-1);
1015                                 }
1016 #endif
1017
1018                                 if (nxt == IPPROTO_AH)
1019                                         eoff += (eh->ip6e_len + 2) << 2;
1020                                 else
1021                                         eoff += (eh->ip6e_len + 1) << 3;
1022                                 nxt = eh->ip6e_nxt;
1023                                 break;
1024                         case IPPROTO_ROUTING:
1025                                 /*
1026                                  * When the erroneous packet contains a
1027                                  * routing header, we should examine the
1028                                  * header to determine the final destination.
1029                                  * Otherwise, we can't properly update
1030                                  * information that depends on the final
1031                                  * destination (e.g. path MTU).
1032                                  */
1033 #ifndef PULLDOWN_TEST
1034                                 IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
1035                                 rth = (struct ip6_rthdr *)
1036                                     (mtod(m, caddr_t) + eoff);
1037 #else
1038                                 IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
1039                                     eoff, sizeof(*rth));
1040                                 if (rth == NULL) {
1041                                         ICMP6STAT_INC(icp6s_tooshort);
1042                                         return (-1);
1043                                 }
1044 #endif
1045                                 rthlen = (rth->ip6r_len + 1) << 3;
1046                                 /*
1047                                  * XXX: currently there is no
1048                                  * officially defined type other
1049                                  * than type-0.
1050                                  * Note that if the segment left field
1051                                  * is 0, all intermediate hops must
1052                                  * have been passed.
1053                                  */
1054                                 if (rth->ip6r_segleft &&
1055                                     rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
1056                                         int hops;
1057
1058 #ifndef PULLDOWN_TEST
1059                                         IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
1060                                         rth0 = (struct ip6_rthdr0 *)
1061                                             (mtod(m, caddr_t) + eoff);
1062 #else
1063                                         IP6_EXTHDR_GET(rth0,
1064                                             struct ip6_rthdr0 *, m,
1065                                             eoff, rthlen);
1066                                         if (rth0 == NULL) {
1067                                                 ICMP6STAT_INC(icp6s_tooshort);
1068                                                 return (-1);
1069                                         }
1070 #endif
1071                                         /* just ignore a bogus header */
1072                                         if ((rth0->ip6r0_len % 2) == 0 &&
1073                                             (hops = rth0->ip6r0_len/2))
1074                                                 finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
1075                                 }
1076                                 eoff += rthlen;
1077                                 nxt = rth->ip6r_nxt;
1078                                 break;
1079                         case IPPROTO_FRAGMENT:
1080 #ifndef PULLDOWN_TEST
1081                                 IP6_EXTHDR_CHECK(m, 0, eoff +
1082                                     sizeof(struct ip6_frag), -1);
1083                                 fh = (struct ip6_frag *)(mtod(m, caddr_t) +
1084                                     eoff);
1085 #else
1086                                 IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
1087                                     eoff, sizeof(*fh));
1088                                 if (fh == NULL) {
1089                                         ICMP6STAT_INC(icp6s_tooshort);
1090                                         return (-1);
1091                                 }
1092 #endif
1093                                 /*
1094                                  * Data after a fragment header is meaningless
1095                                  * unless it is the first fragment, but
1096                                  * we'll go to the notify label for path MTU
1097                                  * discovery.
1098                                  */
1099                                 if (fh->ip6f_offlg & IP6F_OFF_MASK)
1100                                         goto notify;
1101
1102                                 eoff += sizeof(struct ip6_frag);
1103                                 nxt = fh->ip6f_nxt;
1104                                 break;
1105                         default:
1106                                 /*
1107                                  * This case includes ESP and the No Next
1108                                  * Header.  In such cases going to the notify
1109                                  * label does not have any meaning
1110                                  * (i.e. ctlfunc will be NULL), but we go
1111                                  * anyway since we might have to update
1112                                  * path MTU information.
1113                                  */
1114                                 goto notify;
1115                         }
1116                 }
1117           notify:
1118 #ifndef PULLDOWN_TEST
1119                 icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
1120 #else
1121                 IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
1122                     sizeof(*icmp6) + sizeof(struct ip6_hdr));
1123                 if (icmp6 == NULL) {
1124                         ICMP6STAT_INC(icp6s_tooshort);
1125                         return (-1);
1126                 }
1127 #endif
1128
1129                 /*
1130                  * retrieve parameters from the inner IPv6 header, and convert
1131                  * them into sockaddr structures.
1132                  * XXX: there is no guarantee that the source or destination
1133                  * addresses of the inner packet are in the same scope as
1134                  * the addresses of the icmp packet.  But there is no other
1135                  * way to determine the zone.
1136                  */
1137                 eip6 = (struct ip6_hdr *)(icmp6 + 1);
1138
1139                 bzero(&icmp6dst, sizeof(icmp6dst));
1140                 icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
1141                 icmp6dst.sin6_family = AF_INET6;
1142                 if (finaldst == NULL)
1143                         icmp6dst.sin6_addr = eip6->ip6_dst;
1144                 else
1145                         icmp6dst.sin6_addr = *finaldst;
1146                 if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
1147                         goto freeit;
1148                 bzero(&icmp6src, sizeof(icmp6src));
1149                 icmp6src.sin6_len = sizeof(struct sockaddr_in6);
1150                 icmp6src.sin6_family = AF_INET6;
1151                 icmp6src.sin6_addr = eip6->ip6_src;
1152                 if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
1153                         goto freeit;
1154                 icmp6src.sin6_flowinfo =
1155                     (eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
1156
1157                 if (finaldst == NULL)
1158                         finaldst = &eip6->ip6_dst;
1159                 ip6cp.ip6c_m = m;
1160                 ip6cp.ip6c_icmp6 = icmp6;
1161                 ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
1162                 ip6cp.ip6c_off = eoff;
1163                 ip6cp.ip6c_finaldst = finaldst;
1164                 ip6cp.ip6c_src = &icmp6src;
1165                 ip6cp.ip6c_nxt = nxt;
1166
1167                 if (icmp6type == ICMP6_PACKET_TOO_BIG) {
1168                         notifymtu = ntohl(icmp6->icmp6_mtu);
1169                         ip6cp.ip6c_cmdarg = (void *)&notifymtu;
1170                         icmp6_mtudisc_update(&ip6cp, 1);        /*XXX*/
1171                 }
1172
1173                 ctlfunc = (void (*)(int, struct sockaddr *, void *))
1174                     (inet6sw[ip6_protox[nxt]].pr_ctlinput);
1175                 if (ctlfunc) {
1176                         (void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
1177                             &ip6cp);
1178                 }
1179         }
1180         *mp = m;
1181         return (0);
1182
1183   freeit:
1184         m_freem(m);
1185         return (-1);
1186 }
1187
1188 void
1189 icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
1190 {
1191         struct in6_addr *dst = ip6cp->ip6c_finaldst;
1192         struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
1193         struct mbuf *m = ip6cp->ip6c_m; /* will be necessary for scope issue */
1194         u_int mtu = ntohl(icmp6->icmp6_mtu);
1195         struct in_conninfo inc;
1196
1197 #if 0
1198         /*
1199          * RFC2460 section 5, last paragraph.
1200          * even though minimum link MTU for IPv6 is IPV6_MMTU,
1201          * we may see ICMPv6 too big with mtu < IPV6_MMTU
1202          * due to packet translator in the middle.
1203          * see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
1204          * special handling.
1205          */
1206         if (mtu < IPV6_MMTU)
1207                 return;
1208 #endif
1209
1210         /*
1211          * we reject ICMPv6 too big with abnormally small value.
1212          * XXX what is the good definition of "abnormally small"?
1213          */
1214         if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
1215                 return;
1216
1217         if (!validated)
1218                 return;
1219
1220         /*
1221          * In case the suggested mtu is less than IPV6_MMTU, we
1222          * only need to remember that it was for above mentioned
1223          * "alwaysfrag" case.
1224          * Try to be as close to the spec as possible.
1225          */
1226         if (mtu < IPV6_MMTU)
1227                 mtu = IPV6_MMTU - 8;
1228
1229         bzero(&inc, sizeof(inc));
1230         inc.inc_flags |= INC_ISIPV6;
1231         inc.inc6_faddr = *dst;
1232         if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
1233                 return;
1234
1235         if (mtu < tcp_maxmtu6(&inc, NULL)) {
1236                 tcp_hc_updatemtu(&inc, mtu);
1237                 ICMP6STAT_INC(icp6s_pmtuchg);
1238         }
1239 }
1240
1241 /*
1242  * Process a Node Information Query packet, based on
1243  * draft-ietf-ipngwg-icmp-name-lookups-07.
1244  *
1245  * Spec incompatibilities:
1246  * - IPv6 Subject address handling
1247  * - IPv4 Subject address handling support missing
1248  * - Proxy reply (answer even if it's not for me)
1249  * - joins NI group address at in6_ifattach() time only, does not cope
1250  *   with hostname changes by sethostname(3)
1251  */
1252 static struct mbuf *
1253 ni6_input(struct mbuf *m, int off)
1254 {
1255         struct icmp6_nodeinfo *ni6, *nni6;
1256         struct mbuf *n = NULL;
1257         struct prison *pr;
1258         u_int16_t qtype;
1259         int subjlen;
1260         int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1261         struct ni_reply_fqdn *fqdn;
1262         int addrs;              /* for NI_QTYPE_NODEADDR */
1263         struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
1264         struct in6_addr in6_subj; /* subject address */
1265         struct ip6_hdr *ip6;
1266         int oldfqdn = 0;        /* if 1, return pascal string (03 draft) */
1267         char *subj = NULL;
1268         struct in6_ifaddr *ia6 = NULL;
1269
1270         ip6 = mtod(m, struct ip6_hdr *);
1271 #ifndef PULLDOWN_TEST
1272         ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
1273 #else
1274         IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
1275         if (ni6 == NULL) {
1276                 /* m is already reclaimed */
1277                 return (NULL);
1278         }
1279 #endif
1280
1281         /*
1282          * Validate IPv6 source address.
1283          * The default configuration MUST be to refuse answering queries from
1284          * global-scope addresses according to RFC4602.
1285          * Notes:
1286          *  - it's not very clear what "refuse" means; this implementation
1287          *    simply drops it.
1288          *  - it's not very easy to identify global-scope (unicast) addresses
1289          *    since there are many prefixes for them.  It should be safer
1290          *    and in practice sufficient to check "all" but loopback and
1291          *    link-local (note that site-local unicast was deprecated and
1292          *    ULA is defined as global scope-wise)
1293          */
1294         if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
1295             !IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
1296             !IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
1297                 goto bad;
1298
1299         /*
1300          * Validate IPv6 destination address.
1301          *
1302          * The Responder must discard the Query without further processing
1303          * unless it is one of the Responder's unicast or anycast addresses, or
1304          * a link-local scope multicast address which the Responder has joined.
1305          * [RFC4602, Section 5.]
1306          */
1307         if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
1308                 if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
1309                         goto bad;
1310                 /* else it's a link-local multicast, fine */
1311         } else {                /* unicast or anycast */
1312                 if ((ia6 = ip6_getdstifaddr(m)) == NULL)
1313                         goto bad; /* XXX impossible */
1314
1315                 if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
1316                     !(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
1317                         ifa_free(&ia6->ia_ifa);
1318                         nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
1319                                 "a temporary address in %s:%d",
1320                                __FILE__, __LINE__));
1321                         goto bad;
1322                 }
1323                 ifa_free(&ia6->ia_ifa);
1324         }
1325
1326         /* validate query Subject field. */
1327         qtype = ntohs(ni6->ni_qtype);
1328         subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
1329         switch (qtype) {
1330         case NI_QTYPE_NOOP:
1331         case NI_QTYPE_SUPTYPES:
1332                 /* 07 draft */
1333                 if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
1334                         break;
1335                 /* FALLTHROUGH */
1336         case NI_QTYPE_FQDN:
1337         case NI_QTYPE_NODEADDR:
1338         case NI_QTYPE_IPV4ADDR:
1339                 switch (ni6->ni_code) {
1340                 case ICMP6_NI_SUBJ_IPV6:
1341 #if ICMP6_NI_SUBJ_IPV6 != 0
1342                 case 0:
1343 #endif
1344                         /*
1345                          * backward compatibility - try to accept 03 draft
1346                          * format, where no Subject is present.
1347                          */
1348                         if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
1349                             subjlen == 0) {
1350                                 oldfqdn++;
1351                                 break;
1352                         }
1353 #if ICMP6_NI_SUBJ_IPV6 != 0
1354                         if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
1355                                 goto bad;
1356 #endif
1357
1358                         if (subjlen != sizeof(struct in6_addr))
1359                                 goto bad;
1360
1361                         /*
1362                          * Validate Subject address.
1363                          *
1364                          * Not sure what exactly "address belongs to the node"
1365                          * means in the spec, is it just unicast, or what?
1366                          *
1367                          * At this moment we consider Subject address as
1368                          * "belong to the node" if the Subject address equals
1369                          * to the IPv6 destination address; validation for
1370                          * IPv6 destination address should have done enough
1371                          * check for us.
1372                          *
1373                          * We do not do proxy at this moment.
1374                          */
1375                         /* m_pulldown instead of copy? */
1376                         m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
1377                             subjlen, (caddr_t)&in6_subj);
1378                         if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
1379                                 goto bad;
1380
1381                         subj = (char *)&in6_subj;
1382                         if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
1383                                 break;
1384
1385                         /*
1386                          * XXX if we are to allow other cases, we should really
1387                          * be careful about scope here.
1388                          * basically, we should disallow queries toward IPv6
1389                          * destination X with subject Y,
1390                          * if scope(X) > scope(Y).
1391                          * if we allow scope(X) > scope(Y), it will result in
1392                          * information leakage across scope boundary.
1393                          */
1394                         goto bad;
1395
1396                 case ICMP6_NI_SUBJ_FQDN:
1397                         /*
1398                          * Validate Subject name with gethostname(3).
1399                          *
1400                          * The behavior may need some debate, since:
1401                          * - we are not sure if the node has FQDN as
1402                          *   hostname (returned by gethostname(3)).
1403                          * - the code does wildcard match for truncated names.
1404                          *   however, we are not sure if we want to perform
1405                          *   wildcard match, if gethostname(3) side has
1406                          *   truncated hostname.
1407                          */
1408                         pr = curthread->td_ucred->cr_prison;
1409                         mtx_lock(&pr->pr_mtx);
1410                         n = ni6_nametodns(pr->pr_hostname,
1411                             strlen(pr->pr_hostname), 0);
1412                         mtx_unlock(&pr->pr_mtx);
1413                         if (!n || n->m_next || n->m_len == 0)
1414                                 goto bad;
1415                         IP6_EXTHDR_GET(subj, char *, m,
1416                             off + sizeof(struct icmp6_nodeinfo), subjlen);
1417                         if (subj == NULL)
1418                                 goto bad;
1419                         if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
1420                             n->m_len)) {
1421                                 goto bad;
1422                         }
1423                         m_freem(n);
1424                         n = NULL;
1425                         break;
1426
1427                 case ICMP6_NI_SUBJ_IPV4:        /* XXX: to be implemented? */
1428                 default:
1429                         goto bad;
1430                 }
1431                 break;
1432         }
1433
1434         /* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
1435         switch (qtype) {
1436         case NI_QTYPE_FQDN:
1437                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
1438                         goto bad;
1439                 break;
1440         case NI_QTYPE_NODEADDR:
1441         case NI_QTYPE_IPV4ADDR:
1442                 if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
1443                         goto bad;
1444                 break;
1445         }
1446
1447         /* guess reply length */
1448         switch (qtype) {
1449         case NI_QTYPE_NOOP:
1450                 break;          /* no reply data */
1451         case NI_QTYPE_SUPTYPES:
1452                 replylen += sizeof(u_int32_t);
1453                 break;
1454         case NI_QTYPE_FQDN:
1455                 /* XXX will append an mbuf */
1456                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1457                 break;
1458         case NI_QTYPE_NODEADDR:
1459                 addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
1460                 if ((replylen += addrs * (sizeof(struct in6_addr) +
1461                     sizeof(u_int32_t))) > MCLBYTES)
1462                         replylen = MCLBYTES; /* XXX: will truncate pkt later */
1463                 break;
1464         case NI_QTYPE_IPV4ADDR:
1465                 /* unsupported - should respond with unknown Qtype? */
1466                 break;
1467         default:
1468                 /*
1469                  * XXX: We must return a reply with the ICMP6 code
1470                  * `unknown Qtype' in this case.  However we regard the case
1471                  * as an FQDN query for backward compatibility.
1472                  * Older versions set a random value to this field,
1473                  * so it rarely varies in the defined qtypes.
1474                  * But the mechanism is not reliable...
1475                  * maybe we should obsolete older versions.
1476                  */
1477                 qtype = NI_QTYPE_FQDN;
1478                 /* XXX will append an mbuf */
1479                 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
1480                 oldfqdn++;
1481                 break;
1482         }
1483
1484         /* Allocate an mbuf to reply. */
1485         if (replylen > MCLBYTES) {
1486                 /*
1487                  * XXX: should we try to allocate more? But MCLBYTES
1488                  * is probably much larger than IPV6_MMTU...
1489                  */
1490                 goto bad;
1491         }
1492         if (replylen > MHLEN)
1493                 n = m_getcl(M_NOWAIT, m->m_type, M_PKTHDR);
1494         else
1495                 n = m_gethdr(M_NOWAIT, m->m_type);
1496         if (n == NULL) {
1497                 m_freem(m);
1498                 return (NULL);
1499         }
1500         m_move_pkthdr(n, m); /* just for recvif and FIB */
1501         n->m_pkthdr.len = n->m_len = replylen;
1502
1503         /* copy mbuf header and IPv6 + Node Information base headers */
1504         bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
1505         nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
1506         bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
1507
1508         /* qtype dependent procedure */
1509         switch (qtype) {
1510         case NI_QTYPE_NOOP:
1511                 nni6->ni_code = ICMP6_NI_SUCCESS;
1512                 nni6->ni_flags = 0;
1513                 break;
1514         case NI_QTYPE_SUPTYPES:
1515         {
1516                 u_int32_t v;
1517                 nni6->ni_code = ICMP6_NI_SUCCESS;
1518                 nni6->ni_flags = htons(0x0000); /* raw bitmap */
1519                 /* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
1520                 v = (u_int32_t)htonl(0x0000000f);
1521                 bcopy(&v, nni6 + 1, sizeof(u_int32_t));
1522                 break;
1523         }
1524         case NI_QTYPE_FQDN:
1525                 nni6->ni_code = ICMP6_NI_SUCCESS;
1526                 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
1527                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
1528                 nni6->ni_flags = 0; /* XXX: meaningless TTL */
1529                 fqdn->ni_fqdn_ttl = 0;  /* ditto. */
1530                 /*
1531                  * XXX do we really have FQDN in hostname?
1532                  */
1533                 pr = curthread->td_ucred->cr_prison;
1534                 mtx_lock(&pr->pr_mtx);
1535                 n->m_next = ni6_nametodns(pr->pr_hostname,
1536                     strlen(pr->pr_hostname), oldfqdn);
1537                 mtx_unlock(&pr->pr_mtx);
1538                 if (n->m_next == NULL)
1539                         goto bad;
1540                 /* XXX we assume that n->m_next is not a chain */
1541                 if (n->m_next->m_next != NULL)
1542                         goto bad;
1543                 n->m_pkthdr.len += n->m_next->m_len;
1544                 break;
1545         case NI_QTYPE_NODEADDR:
1546         {
1547                 int lenlim, copied;
1548
1549                 nni6->ni_code = ICMP6_NI_SUCCESS;
1550                 n->m_pkthdr.len = n->m_len =
1551                     sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
1552                 lenlim = M_TRAILINGSPACE(n);
1553                 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
1554                 /* XXX: reset mbuf length */
1555                 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
1556                     sizeof(struct icmp6_nodeinfo) + copied;
1557                 break;
1558         }
1559         default:
1560                 break;          /* XXX impossible! */
1561         }
1562
1563         nni6->ni_type = ICMP6_NI_REPLY;
1564         m_freem(m);
1565         return (n);
1566
1567   bad:
1568         m_freem(m);
1569         if (n)
1570                 m_freem(n);
1571         return (NULL);
1572 }
1573
1574 /*
1575  * make a mbuf with DNS-encoded string.  no compression support.
1576  *
1577  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
1578  * treated as truncated name (two \0 at the end).  this is a wild guess.
1579  *
1580  * old - return pascal string if non-zero
1581  */
1582 static struct mbuf *
1583 ni6_nametodns(const char *name, int namelen, int old)
1584 {
1585         struct mbuf *m;
1586         char *cp, *ep;
1587         const char *p, *q;
1588         int i, len, nterm;
1589
1590         if (old)
1591                 len = namelen + 1;
1592         else
1593                 len = MCLBYTES;
1594
1595         /* Because MAXHOSTNAMELEN is usually 256, we use cluster mbuf. */
1596         if (len > MLEN)
1597                 m = m_getcl(M_NOWAIT, MT_DATA, 0);
1598         else
1599                 m = m_get(M_NOWAIT, MT_DATA);
1600         if (m == NULL)
1601                 goto fail;
1602
1603         if (old) {
1604                 m->m_len = len;
1605                 *mtod(m, char *) = namelen;
1606                 bcopy(name, mtod(m, char *) + 1, namelen);
1607                 return m;
1608         } else {
1609                 m->m_len = 0;
1610                 cp = mtod(m, char *);
1611                 ep = mtod(m, char *) + M_TRAILINGSPACE(m);
1612
1613                 /* if not certain about my name, return empty buffer */
1614                 if (namelen == 0)
1615                         return m;
1616
1617                 /*
1618                  * guess if it looks like shortened hostname, or FQDN.
1619                  * shortened hostname needs two trailing "\0".
1620                  */
1621                 i = 0;
1622                 for (p = name; p < name + namelen; p++) {
1623                         if (*p && *p == '.')
1624                                 i++;
1625                 }
1626                 if (i < 2)
1627                         nterm = 2;
1628                 else
1629                         nterm = 1;
1630
1631                 p = name;
1632                 while (cp < ep && p < name + namelen) {
1633                         i = 0;
1634                         for (q = p; q < name + namelen && *q && *q != '.'; q++)
1635                                 i++;
1636                         /* result does not fit into mbuf */
1637                         if (cp + i + 1 >= ep)
1638                                 goto fail;
1639                         /*
1640                          * DNS label length restriction, RFC1035 page 8.
1641                          * "i == 0" case is included here to avoid returning
1642                          * 0-length label on "foo..bar".
1643                          */
1644                         if (i <= 0 || i >= 64)
1645                                 goto fail;
1646                         *cp++ = i;
1647                         bcopy(p, cp, i);
1648                         cp += i;
1649                         p = q;
1650                         if (p < name + namelen && *p == '.')
1651                                 p++;
1652                 }
1653                 /* termination */
1654                 if (cp + nterm >= ep)
1655                         goto fail;
1656                 while (nterm-- > 0)
1657                         *cp++ = '\0';
1658                 m->m_len = cp - mtod(m, char *);
1659                 return m;
1660         }
1661
1662         panic("should not reach here");
1663         /* NOTREACHED */
1664
1665  fail:
1666         if (m)
1667                 m_freem(m);
1668         return NULL;
1669 }
1670
1671 /*
1672  * check if two DNS-encoded string matches.  takes care of truncated
1673  * form (with \0\0 at the end).  no compression support.
1674  * XXX upper/lowercase match (see RFC2065)
1675  */
1676 static int
1677 ni6_dnsmatch(const char *a, int alen, const char *b, int blen)
1678 {
1679         const char *a0, *b0;
1680         int l;
1681
1682         /* simplest case - need validation? */
1683         if (alen == blen && bcmp(a, b, alen) == 0)
1684                 return 1;
1685
1686         a0 = a;
1687         b0 = b;
1688
1689         /* termination is mandatory */
1690         if (alen < 2 || blen < 2)
1691                 return 0;
1692         if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
1693                 return 0;
1694         alen--;
1695         blen--;
1696
1697         while (a - a0 < alen && b - b0 < blen) {
1698                 if (a - a0 + 1 > alen || b - b0 + 1 > blen)
1699                         return 0;
1700
1701                 if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
1702                         return 0;
1703                 /* we don't support compression yet */
1704                 if (a[0] >= 64 || b[0] >= 64)
1705                         return 0;
1706
1707                 /* truncated case */
1708                 if (a[0] == 0 && a - a0 == alen - 1)
1709                         return 1;
1710                 if (b[0] == 0 && b - b0 == blen - 1)
1711                         return 1;
1712                 if (a[0] == 0 || b[0] == 0)
1713                         return 0;
1714
1715                 if (a[0] != b[0])
1716                         return 0;
1717                 l = a[0];
1718                 if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
1719                         return 0;
1720                 if (bcmp(a + 1, b + 1, l) != 0)
1721                         return 0;
1722
1723                 a += 1 + l;
1724                 b += 1 + l;
1725         }
1726
1727         if (a - a0 == alen && b - b0 == blen)
1728                 return 1;
1729         else
1730                 return 0;
1731 }
1732
1733 /*
1734  * calculate the number of addresses to be returned in the node info reply.
1735  */
1736 static int
1737 ni6_addrs(struct icmp6_nodeinfo *ni6, struct mbuf *m, struct ifnet **ifpp,
1738     struct in6_addr *subj)
1739 {
1740         struct ifnet *ifp;
1741         struct in6_ifaddr *ifa6;
1742         struct ifaddr *ifa;
1743         int addrs = 0, addrsofif, iffound = 0;
1744         int niflags = ni6->ni_flags;
1745
1746         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
1747                 switch (ni6->ni_code) {
1748                 case ICMP6_NI_SUBJ_IPV6:
1749                         if (subj == NULL) /* must be impossible... */
1750                                 return (0);
1751                         break;
1752                 default:
1753                         /*
1754                          * XXX: we only support IPv6 subject address for
1755                          * this Qtype.
1756                          */
1757                         return (0);
1758                 }
1759         }
1760
1761         IFNET_RLOCK_NOSLEEP();
1762         TAILQ_FOREACH(ifp, &V_ifnet, if_list) {
1763                 addrsofif = 0;
1764                 IF_ADDR_RLOCK(ifp);
1765                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1766                         if (ifa->ifa_addr->sa_family != AF_INET6)
1767                                 continue;
1768                         ifa6 = (struct in6_ifaddr *)ifa;
1769
1770                         if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
1771                             IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
1772                                 iffound = 1;
1773
1774                         /*
1775                          * IPv4-mapped addresses can only be returned by a
1776                          * Node Information proxy, since they represent
1777                          * addresses of IPv4-only nodes, which perforce do
1778                          * not implement this protocol.
1779                          * [icmp-name-lookups-07, Section 5.4]
1780                          * So we don't support NI_NODEADDR_FLAG_COMPAT in
1781                          * this function at this moment.
1782                          */
1783
1784                         /* What do we have to do about ::1? */
1785                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1786                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1787                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1788                                         continue;
1789                                 break;
1790                         case IPV6_ADDR_SCOPE_SITELOCAL:
1791                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1792                                         continue;
1793                                 break;
1794                         case IPV6_ADDR_SCOPE_GLOBAL:
1795                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1796                                         continue;
1797                                 break;
1798                         default:
1799                                 continue;
1800                         }
1801
1802                         /*
1803                          * check if anycast is okay.
1804                          * XXX: just experimental.  not in the spec.
1805                          */
1806                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1807                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1808                                 continue; /* we need only unicast addresses */
1809                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1810                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1811                                 continue;
1812                         }
1813                         addrsofif++; /* count the address */
1814                 }
1815                 IF_ADDR_RUNLOCK(ifp);
1816                 if (iffound) {
1817                         *ifpp = ifp;
1818                         IFNET_RUNLOCK_NOSLEEP();
1819                         return (addrsofif);
1820                 }
1821
1822                 addrs += addrsofif;
1823         }
1824         IFNET_RUNLOCK_NOSLEEP();
1825
1826         return (addrs);
1827 }
1828
1829 static int
1830 ni6_store_addrs(struct icmp6_nodeinfo *ni6, struct icmp6_nodeinfo *nni6,
1831     struct ifnet *ifp0, int resid)
1832 {
1833         struct ifnet *ifp;
1834         struct in6_ifaddr *ifa6;
1835         struct ifaddr *ifa;
1836         struct ifnet *ifp_dep = NULL;
1837         int copied = 0, allow_deprecated = 0;
1838         u_char *cp = (u_char *)(nni6 + 1);
1839         int niflags = ni6->ni_flags;
1840         u_int32_t ltime;
1841
1842         if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
1843                 return (0);     /* needless to copy */
1844
1845         IFNET_RLOCK_NOSLEEP();
1846         ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
1847   again:
1848
1849         for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
1850                 IF_ADDR_RLOCK(ifp);
1851                 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1852                         if (ifa->ifa_addr->sa_family != AF_INET6)
1853                                 continue;
1854                         ifa6 = (struct in6_ifaddr *)ifa;
1855
1856                         if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
1857                             allow_deprecated == 0) {
1858                                 /*
1859                                  * prefererred address should be put before
1860                                  * deprecated addresses.
1861                                  */
1862
1863                                 /* record the interface for later search */
1864                                 if (ifp_dep == NULL)
1865                                         ifp_dep = ifp;
1866
1867                                 continue;
1868                         } else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
1869                             allow_deprecated != 0)
1870                                 continue; /* we now collect deprecated addrs */
1871
1872                         /* What do we have to do about ::1? */
1873                         switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
1874                         case IPV6_ADDR_SCOPE_LINKLOCAL:
1875                                 if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
1876                                         continue;
1877                                 break;
1878                         case IPV6_ADDR_SCOPE_SITELOCAL:
1879                                 if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
1880                                         continue;
1881                                 break;
1882                         case IPV6_ADDR_SCOPE_GLOBAL:
1883                                 if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
1884                                         continue;
1885                                 break;
1886                         default:
1887                                 continue;
1888                         }
1889
1890                         /*
1891                          * check if anycast is okay.
1892                          * XXX: just experimental.  not in the spec.
1893                          */
1894                         if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
1895                             (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
1896                                 continue;
1897                         if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1898                             (V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
1899                                 continue;
1900                         }
1901
1902                         /* now we can copy the address */
1903                         if (resid < sizeof(struct in6_addr) +
1904                             sizeof(u_int32_t)) {
1905                                 IF_ADDR_RUNLOCK(ifp);
1906                                 /*
1907                                  * We give up much more copy.
1908                                  * Set the truncate flag and return.
1909                                  */
1910                                 nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
1911                                 IFNET_RUNLOCK_NOSLEEP();
1912                                 return (copied);
1913                         }
1914
1915                         /*
1916                          * Set the TTL of the address.
1917                          * The TTL value should be one of the following
1918                          * according to the specification:
1919                          *
1920                          * 1. The remaining lifetime of a DHCP lease on the
1921                          *    address, or
1922                          * 2. The remaining Valid Lifetime of a prefix from
1923                          *    which the address was derived through Stateless
1924                          *    Autoconfiguration.
1925                          *
1926                          * Note that we currently do not support stateful
1927                          * address configuration by DHCPv6, so the former
1928                          * case can't happen.
1929                          */
1930                         if (ifa6->ia6_lifetime.ia6t_expire == 0)
1931                                 ltime = ND6_INFINITE_LIFETIME;
1932                         else {
1933                                 if (ifa6->ia6_lifetime.ia6t_expire >
1934                                     time_uptime)
1935                                         ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_uptime);
1936                                 else
1937                                         ltime = 0;
1938                         }
1939
1940                         bcopy(&ltime, cp, sizeof(u_int32_t));
1941                         cp += sizeof(u_int32_t);
1942
1943                         /* copy the address itself */
1944                         bcopy(&ifa6->ia_addr.sin6_addr, cp,
1945                             sizeof(struct in6_addr));
1946                         in6_clearscope((struct in6_addr *)cp); /* XXX */
1947                         cp += sizeof(struct in6_addr);
1948
1949                         resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
1950                         copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
1951                 }
1952                 IF_ADDR_RUNLOCK(ifp);
1953                 if (ifp0)       /* we need search only on the specified IF */
1954                         break;
1955         }
1956
1957         if (allow_deprecated == 0 && ifp_dep != NULL) {
1958                 ifp = ifp_dep;
1959                 allow_deprecated = 1;
1960
1961                 goto again;
1962         }
1963
1964         IFNET_RUNLOCK_NOSLEEP();
1965
1966         return (copied);
1967 }
1968
1969 /*
1970  * XXX almost dup'ed code with rip6_input.
1971  */
1972 static int
1973 icmp6_rip6_input(struct mbuf **mp, int off)
1974 {
1975         struct mbuf *m = *mp;
1976         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
1977         struct inpcb *in6p;
1978         struct inpcb *last = NULL;
1979         struct sockaddr_in6 fromsa;
1980         struct icmp6_hdr *icmp6;
1981         struct mbuf *opts = NULL;
1982
1983 #ifndef PULLDOWN_TEST
1984         /* this is assumed to be safe. */
1985         icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
1986 #else
1987         IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
1988         if (icmp6 == NULL) {
1989                 /* m is already reclaimed */
1990                 return (IPPROTO_DONE);
1991         }
1992 #endif
1993
1994         /*
1995          * XXX: the address may have embedded scope zone ID, which should be
1996          * hidden from applications.
1997          */
1998         bzero(&fromsa, sizeof(fromsa));
1999         fromsa.sin6_family = AF_INET6;
2000         fromsa.sin6_len = sizeof(struct sockaddr_in6);
2001         fromsa.sin6_addr = ip6->ip6_src;
2002         if (sa6_recoverscope(&fromsa)) {
2003                 m_freem(m);
2004                 return (IPPROTO_DONE);
2005         }
2006
2007         INP_INFO_RLOCK(&V_ripcbinfo);
2008         LIST_FOREACH(in6p, &V_ripcb, inp_list) {
2009                 if ((in6p->inp_vflag & INP_IPV6) == 0)
2010                         continue;
2011                 if (in6p->inp_ip_p != IPPROTO_ICMPV6)
2012                         continue;
2013                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
2014                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
2015                         continue;
2016                 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
2017                    !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
2018                         continue;
2019                 INP_RLOCK(in6p);
2020                 if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
2021                     in6p->in6p_icmp6filt)) {
2022                         INP_RUNLOCK(in6p);
2023                         continue;
2024                 }
2025                 if (last != NULL) {
2026                         struct  mbuf *n = NULL;
2027
2028                         /*
2029                          * Recent network drivers tend to allocate a single
2030                          * mbuf cluster, rather than to make a couple of
2031                          * mbufs without clusters.  Also, since the IPv6 code
2032                          * path tries to avoid m_pullup(), it is highly
2033                          * probable that we still have an mbuf cluster here
2034                          * even though the necessary length can be stored in an
2035                          * mbuf's internal buffer.
2036                          * Meanwhile, the default size of the receive socket
2037                          * buffer for raw sockets is not so large.  This means
2038                          * the possibility of packet loss is relatively higher
2039                          * than before.  To avoid this scenario, we copy the
2040                          * received data to a separate mbuf that does not use
2041                          * a cluster, if possible.
2042                          * XXX: it is better to copy the data after stripping
2043                          * intermediate headers.
2044                          */
2045                         if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2046                             m->m_len <= MHLEN) {
2047                                 n = m_get(M_NOWAIT, m->m_type);
2048                                 if (n != NULL) {
2049                                         if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2050                                                 bcopy(m->m_data, n->m_data,
2051                                                       m->m_len);
2052                                                 n->m_len = m->m_len;
2053                                         } else {
2054                                                 m_free(n);
2055                                                 n = NULL;
2056                                         }
2057                                 }
2058                         }
2059                         if (n != NULL ||
2060                             (n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
2061                                 if (last->inp_flags & INP_CONTROLOPTS)
2062                                         ip6_savecontrol(last, n, &opts);
2063                                 /* strip intermediate headers */
2064                                 m_adj(n, off);
2065                                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2066                                 if (sbappendaddr_locked(
2067                                     &last->inp_socket->so_rcv,
2068                                     (struct sockaddr *)&fromsa, n, opts)
2069                                     == 0) {
2070                                         /* should notify about lost packet */
2071                                         m_freem(n);
2072                                         if (opts) {
2073                                                 m_freem(opts);
2074                                         }
2075                                         SOCKBUF_UNLOCK(
2076                                             &last->inp_socket->so_rcv);
2077                                 } else
2078                                         sorwakeup_locked(last->inp_socket);
2079                                 opts = NULL;
2080                         }
2081                         INP_RUNLOCK(last);
2082                 }
2083                 last = in6p;
2084         }
2085         INP_INFO_RUNLOCK(&V_ripcbinfo);
2086         if (last != NULL) {
2087                 if (last->inp_flags & INP_CONTROLOPTS)
2088                         ip6_savecontrol(last, m, &opts);
2089                 /* strip intermediate headers */
2090                 m_adj(m, off);
2091
2092                 /* avoid using mbuf clusters if possible (see above) */
2093                 if ((m->m_flags & M_EXT) && m->m_next == NULL &&
2094                     m->m_len <= MHLEN) {
2095                         struct mbuf *n;
2096
2097                         n = m_get(M_NOWAIT, m->m_type);
2098                         if (n != NULL) {
2099                                 if (m_dup_pkthdr(n, m, M_NOWAIT)) {
2100                                         bcopy(m->m_data, n->m_data, m->m_len);
2101                                         n->m_len = m->m_len;
2102
2103                                         m_freem(m);
2104                                         m = n;
2105                                 } else {
2106                                         m_freem(n);
2107                                         n = NULL;
2108                                 }
2109                         }
2110                 }
2111                 SOCKBUF_LOCK(&last->inp_socket->so_rcv);
2112                 if (sbappendaddr_locked(&last->inp_socket->so_rcv,
2113                     (struct sockaddr *)&fromsa, m, opts) == 0) {
2114                         m_freem(m);
2115                         if (opts)
2116                                 m_freem(opts);
2117                         SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
2118                 } else
2119                         sorwakeup_locked(last->inp_socket);
2120                 INP_RUNLOCK(last);
2121         } else {
2122                 m_freem(m);
2123                 IP6STAT_DEC(ip6s_delivered);
2124         }
2125         return IPPROTO_DONE;
2126 }
2127
2128 /*
2129  * Reflect the ip6 packet back to the source.
2130  * OFF points to the icmp6 header, counted from the top of the mbuf.
2131  */
2132 void
2133 icmp6_reflect(struct mbuf *m, size_t off)
2134 {
2135         struct ip6_hdr *ip6;
2136         struct icmp6_hdr *icmp6;
2137         struct in6_ifaddr *ia = NULL;
2138         int plen;
2139         int type, code;
2140         struct ifnet *outif = NULL;
2141         struct in6_addr origdst, src, *srcp = NULL;
2142
2143         /* too short to reflect */
2144         if (off < sizeof(struct ip6_hdr)) {
2145                 nd6log((LOG_DEBUG,
2146                     "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
2147                     (u_long)off, (u_long)sizeof(struct ip6_hdr),
2148                     __FILE__, __LINE__));
2149                 goto bad;
2150         }
2151
2152         /*
2153          * If there are extra headers between IPv6 and ICMPv6, strip
2154          * off that header first.
2155          */
2156 #ifdef DIAGNOSTIC
2157         if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
2158                 panic("assumption failed in icmp6_reflect");
2159 #endif
2160         if (off > sizeof(struct ip6_hdr)) {
2161                 size_t l;
2162                 struct ip6_hdr nip6;
2163
2164                 l = off - sizeof(struct ip6_hdr);
2165                 m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
2166                 m_adj(m, l);
2167                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2168                 if (m->m_len < l) {
2169                         if ((m = m_pullup(m, l)) == NULL)
2170                                 return;
2171                 }
2172                 bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
2173         } else /* off == sizeof(struct ip6_hdr) */ {
2174                 size_t l;
2175                 l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
2176                 if (m->m_len < l) {
2177                         if ((m = m_pullup(m, l)) == NULL)
2178                                 return;
2179                 }
2180         }
2181         plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
2182         ip6 = mtod(m, struct ip6_hdr *);
2183         ip6->ip6_nxt = IPPROTO_ICMPV6;
2184         icmp6 = (struct icmp6_hdr *)(ip6 + 1);
2185         type = icmp6->icmp6_type; /* keep type for statistics */
2186         code = icmp6->icmp6_code; /* ditto. */
2187
2188         origdst = ip6->ip6_dst;
2189         /*
2190          * ip6_input() drops a packet if its src is multicast.
2191          * So, the src is never multicast.
2192          */
2193         ip6->ip6_dst = ip6->ip6_src;
2194
2195         /*
2196          * If the incoming packet was addressed directly to us (i.e. unicast),
2197          * use dst as the src for the reply.
2198          * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
2199          * (for example) when we encounter an error while forwarding procedure
2200          * destined to a duplicated address of ours.
2201          * Note that ip6_getdstifaddr() may fail if we are in an error handling
2202          * procedure of an outgoing packet of our own, in which case we need
2203          * to search in the ifaddr list.
2204          */
2205         if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
2206                 if ((ia = ip6_getdstifaddr(m))) {
2207                         if (!(ia->ia6_flags &
2208                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
2209                                 srcp = &ia->ia_addr.sin6_addr;
2210                 } else {
2211                         struct sockaddr_in6 d;
2212
2213                         bzero(&d, sizeof(d));
2214                         d.sin6_family = AF_INET6;
2215                         d.sin6_len = sizeof(d);
2216                         d.sin6_addr = origdst;
2217                         ia = (struct in6_ifaddr *)
2218                             ifa_ifwithaddr((struct sockaddr *)&d);
2219                         if (ia &&
2220                             !(ia->ia6_flags &
2221                             (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
2222                                 srcp = &ia->ia_addr.sin6_addr;
2223                         }
2224                 }
2225         }
2226
2227         if (srcp == NULL) {
2228                 int e;
2229                 struct sockaddr_in6 sin6;
2230                 struct route_in6 ro;
2231
2232                 /*
2233                  * This case matches to multicasts, our anycast, or unicasts
2234                  * that we do not own.  Select a source address based on the
2235                  * source address of the erroneous packet.
2236                  */
2237                 bzero(&sin6, sizeof(sin6));
2238                 sin6.sin6_family = AF_INET6;
2239                 sin6.sin6_len = sizeof(sin6);
2240                 sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
2241
2242                 bzero(&ro, sizeof(ro));
2243                 e = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &src);
2244                 if (ro.ro_rt)
2245                         RTFREE(ro.ro_rt); /* XXX: we could use this */
2246                 if (e) {
2247                         char ip6buf[INET6_ADDRSTRLEN];
2248                         nd6log((LOG_DEBUG,
2249                             "icmp6_reflect: source can't be determined: "
2250                             "dst=%s, error=%d\n",
2251                             ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
2252                         goto bad;
2253                 }
2254                 srcp = &src;
2255         }
2256
2257         ip6->ip6_src = *srcp;
2258         ip6->ip6_flow = 0;
2259         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2260         ip6->ip6_vfc |= IPV6_VERSION;
2261         ip6->ip6_nxt = IPPROTO_ICMPV6;
2262         if (outif)
2263                 ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
2264         else if (m->m_pkthdr.rcvif) {
2265                 /* XXX: This may not be the outgoing interface */
2266                 ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
2267         } else
2268                 ip6->ip6_hlim = V_ip6_defhlim;
2269
2270         icmp6->icmp6_cksum = 0;
2271         icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2272             sizeof(struct ip6_hdr), plen);
2273
2274         /*
2275          * XXX option handling
2276          */
2277
2278         m->m_flags &= ~(M_BCAST|M_MCAST);
2279
2280         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2281         if (outif)
2282                 icmp6_ifoutstat_inc(outif, type, code);
2283
2284         if (ia != NULL)
2285                 ifa_free(&ia->ia_ifa);
2286         return;
2287
2288  bad:
2289         if (ia != NULL)
2290                 ifa_free(&ia->ia_ifa);
2291         m_freem(m);
2292         return;
2293 }
2294
2295 void
2296 icmp6_fasttimo(void)
2297 {
2298
2299         mld_fasttimo();
2300 }
2301
2302 void
2303 icmp6_slowtimo(void)
2304 {
2305
2306         mld_slowtimo();
2307 }
2308
2309 static const char *
2310 icmp6_redirect_diag(struct in6_addr *src6, struct in6_addr *dst6,
2311     struct in6_addr *tgt6)
2312 {
2313         static char buf[1024];
2314         char ip6bufs[INET6_ADDRSTRLEN];
2315         char ip6bufd[INET6_ADDRSTRLEN];
2316         char ip6buft[INET6_ADDRSTRLEN];
2317         snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
2318             ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
2319             ip6_sprintf(ip6buft, tgt6));
2320         return buf;
2321 }
2322
2323 void
2324 icmp6_redirect_input(struct mbuf *m, int off)
2325 {
2326         struct ifnet *ifp;
2327         struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
2328         struct nd_redirect *nd_rd;
2329         int icmp6len = ntohs(ip6->ip6_plen);
2330         char *lladdr = NULL;
2331         int lladdrlen = 0;
2332         struct rtentry *rt = NULL;
2333         int is_router;
2334         int is_onlink;
2335         struct in6_addr src6 = ip6->ip6_src;
2336         struct in6_addr redtgt6;
2337         struct in6_addr reddst6;
2338         union nd_opts ndopts;
2339         char ip6buf[INET6_ADDRSTRLEN];
2340
2341         M_ASSERTPKTHDR(m);
2342         KASSERT(m->m_pkthdr.rcvif != NULL, ("%s: no rcvif", __func__));
2343
2344         ifp = m->m_pkthdr.rcvif;
2345
2346         /* XXX if we are router, we don't update route by icmp6 redirect */
2347         if (V_ip6_forwarding)
2348                 goto freeit;
2349         if (!V_icmp6_rediraccept)
2350                 goto freeit;
2351
2352 #ifndef PULLDOWN_TEST
2353         IP6_EXTHDR_CHECK(m, off, icmp6len,);
2354         nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
2355 #else
2356         IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
2357         if (nd_rd == NULL) {
2358                 ICMP6STAT_INC(icp6s_tooshort);
2359                 return;
2360         }
2361 #endif
2362         redtgt6 = nd_rd->nd_rd_target;
2363         reddst6 = nd_rd->nd_rd_dst;
2364
2365         if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
2366             in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
2367                 goto freeit;
2368         }
2369
2370         /* validation */
2371         if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
2372                 nd6log((LOG_ERR,
2373                     "ICMP6 redirect sent from %s rejected; "
2374                     "must be from linklocal\n",
2375                     ip6_sprintf(ip6buf, &src6)));
2376                 goto bad;
2377         }
2378         if (ip6->ip6_hlim != 255) {
2379                 nd6log((LOG_ERR,
2380                     "ICMP6 redirect sent from %s rejected; "
2381                     "hlim=%d (must be 255)\n",
2382                     ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
2383                 goto bad;
2384         }
2385     {
2386         /* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
2387         struct sockaddr_in6 sin6;
2388         struct in6_addr *gw6;
2389
2390         bzero(&sin6, sizeof(sin6));
2391         sin6.sin6_family = AF_INET6;
2392         sin6.sin6_len = sizeof(struct sockaddr_in6);
2393         bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
2394         rt = in6_rtalloc1((struct sockaddr *)&sin6, 0, 0UL, RT_DEFAULT_FIB);
2395         if (rt) {
2396                 if (rt->rt_gateway == NULL ||
2397                     rt->rt_gateway->sa_family != AF_INET6) {
2398                         RTFREE_LOCKED(rt);
2399                         nd6log((LOG_ERR,
2400                             "ICMP6 redirect rejected; no route "
2401                             "with inet6 gateway found for redirect dst: %s\n",
2402                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2403                         goto bad;
2404                 }
2405
2406                 gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
2407                 if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
2408                         RTFREE_LOCKED(rt);
2409                         nd6log((LOG_ERR,
2410                             "ICMP6 redirect rejected; "
2411                             "not equal to gw-for-src=%s (must be same): "
2412                             "%s\n",
2413                             ip6_sprintf(ip6buf, gw6),
2414                             icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2415                         goto bad;
2416                 }
2417         } else {
2418                 nd6log((LOG_ERR,
2419                     "ICMP6 redirect rejected; "
2420                     "no route found for redirect dst: %s\n",
2421                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2422                 goto bad;
2423         }
2424         RTFREE_LOCKED(rt);
2425         rt = NULL;
2426     }
2427         if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
2428                 nd6log((LOG_ERR,
2429                     "ICMP6 redirect rejected; "
2430                     "redirect dst must be unicast: %s\n",
2431                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2432                 goto bad;
2433         }
2434
2435         is_router = is_onlink = 0;
2436         if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
2437                 is_router = 1;  /* router case */
2438         if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
2439                 is_onlink = 1;  /* on-link destination case */
2440         if (!is_router && !is_onlink) {
2441                 nd6log((LOG_ERR,
2442                     "ICMP6 redirect rejected; "
2443                     "neither router case nor onlink case: %s\n",
2444                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2445                 goto bad;
2446         }
2447         /* validation passed */
2448
2449         icmp6len -= sizeof(*nd_rd);
2450         nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
2451         if (nd6_options(&ndopts) < 0) {
2452                 nd6log((LOG_INFO, "%s: invalid ND option, rejected: %s\n",
2453                     __func__, icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2454                 /* nd6_options have incremented stats */
2455                 goto freeit;
2456         }
2457
2458         if (ndopts.nd_opts_tgt_lladdr) {
2459                 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
2460                 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
2461         }
2462
2463         if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
2464                 nd6log((LOG_INFO, "%s: lladdrlen mismatch for %s "
2465                     "(if %d, icmp6 packet %d): %s\n",
2466                     __func__, ip6_sprintf(ip6buf, &redtgt6),
2467                     ifp->if_addrlen, lladdrlen - 2,
2468                     icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
2469                 goto bad;
2470         }
2471
2472         /* RFC 2461 8.3 */
2473         nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
2474             is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
2475
2476         if (!is_onlink) {       /* better router case.  perform rtredirect. */
2477                 /* perform rtredirect */
2478                 struct sockaddr_in6 sdst;
2479                 struct sockaddr_in6 sgw;
2480                 struct sockaddr_in6 ssrc;
2481                 u_int fibnum;
2482
2483                 bzero(&sdst, sizeof(sdst));
2484                 bzero(&sgw, sizeof(sgw));
2485                 bzero(&ssrc, sizeof(ssrc));
2486                 sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
2487                 sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
2488                         sizeof(struct sockaddr_in6);
2489                 bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
2490                 bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2491                 bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
2492                 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
2493                         in6_rtredirect((struct sockaddr *)&sdst,
2494                             (struct sockaddr *)&sgw, (struct sockaddr *)NULL,
2495                             RTF_GATEWAY | RTF_HOST, (struct sockaddr *)&ssrc,
2496                             fibnum);
2497         }
2498         /* finally update cached route in each socket via pfctlinput */
2499     {
2500         struct sockaddr_in6 sdst;
2501
2502         bzero(&sdst, sizeof(sdst));
2503         sdst.sin6_family = AF_INET6;
2504         sdst.sin6_len = sizeof(struct sockaddr_in6);
2505         bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
2506         pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
2507 #ifdef IPSEC
2508         key_sa_routechange((struct sockaddr *)&sdst);
2509 #endif /* IPSEC */
2510     }
2511
2512  freeit:
2513         m_freem(m);
2514         return;
2515
2516  bad:
2517         ICMP6STAT_INC(icp6s_badredirect);
2518         m_freem(m);
2519 }
2520
2521 void
2522 icmp6_redirect_output(struct mbuf *m0, struct rtentry *rt)
2523 {
2524         struct ifnet *ifp;      /* my outgoing interface */
2525         struct in6_addr *ifp_ll6;
2526         struct in6_addr *router_ll6;
2527         struct ip6_hdr *sip6;   /* m0 as struct ip6_hdr */
2528         struct mbuf *m = NULL;  /* newly allocated one */
2529         struct m_tag *mtag;
2530         struct ip6_hdr *ip6;    /* m as struct ip6_hdr */
2531         struct nd_redirect *nd_rd;
2532         struct llentry *ln = NULL;
2533         size_t maxlen;
2534         u_char *p;
2535         struct ifnet *outif = NULL;
2536         struct sockaddr_in6 src_sa;
2537
2538         icmp6_errcount(ND_REDIRECT, 0);
2539
2540         /* if we are not router, we don't send icmp6 redirect */
2541         if (!V_ip6_forwarding)
2542                 goto fail;
2543
2544         /* sanity check */
2545         if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
2546                 goto fail;
2547
2548         /*
2549          * Address check:
2550          *  the source address must identify a neighbor, and
2551          *  the destination address must not be a multicast address
2552          *  [RFC 2461, sec 8.2]
2553          */
2554         sip6 = mtod(m0, struct ip6_hdr *);
2555         bzero(&src_sa, sizeof(src_sa));
2556         src_sa.sin6_family = AF_INET6;
2557         src_sa.sin6_len = sizeof(src_sa);
2558         src_sa.sin6_addr = sip6->ip6_src;
2559         if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
2560                 goto fail;
2561         if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
2562                 goto fail;      /* what should we do here? */
2563
2564         /* rate limit */
2565         if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
2566                 goto fail;
2567
2568         /*
2569          * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
2570          * we almost always ask for an mbuf cluster for simplicity.
2571          * (MHLEN < IPV6_MMTU is almost always true)
2572          */
2573 #if IPV6_MMTU >= MCLBYTES
2574 # error assumption failed about IPV6_MMTU and MCLBYTES
2575 #endif
2576         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
2577         if (m == NULL)
2578                 goto fail;
2579         M_SETFIB(m, rt->rt_fibnum);
2580         maxlen = M_TRAILINGSPACE(m);
2581         maxlen = min(IPV6_MMTU, maxlen);
2582         /* just for safety */
2583         if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
2584             ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
2585                 goto fail;
2586         }
2587
2588         {
2589                 /* get ip6 linklocal address for ifp(my outgoing interface). */
2590                 struct in6_ifaddr *ia;
2591                 if ((ia = in6ifa_ifpforlinklocal(ifp,
2592                                                  IN6_IFF_NOTREADY|
2593                                                  IN6_IFF_ANYCAST)) == NULL)
2594                         goto fail;
2595                 ifp_ll6 = &ia->ia_addr.sin6_addr;
2596                 /* XXXRW: reference released prematurely. */
2597                 ifa_free(&ia->ia_ifa);
2598         }
2599
2600         /* get ip6 linklocal address for the router. */
2601         if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
2602                 struct sockaddr_in6 *sin6;
2603                 sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
2604                 router_ll6 = &sin6->sin6_addr;
2605                 if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
2606                         router_ll6 = (struct in6_addr *)NULL;
2607         } else
2608                 router_ll6 = (struct in6_addr *)NULL;
2609
2610         /* ip6 */
2611         ip6 = mtod(m, struct ip6_hdr *);
2612         ip6->ip6_flow = 0;
2613         ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
2614         ip6->ip6_vfc |= IPV6_VERSION;
2615         /* ip6->ip6_plen will be set later */
2616         ip6->ip6_nxt = IPPROTO_ICMPV6;
2617         ip6->ip6_hlim = 255;
2618         /* ip6->ip6_src must be linklocal addr for my outgoing if. */
2619         bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
2620         bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
2621
2622         /* ND Redirect */
2623         nd_rd = (struct nd_redirect *)(ip6 + 1);
2624         nd_rd->nd_rd_type = ND_REDIRECT;
2625         nd_rd->nd_rd_code = 0;
2626         nd_rd->nd_rd_reserved = 0;
2627         if (rt->rt_flags & RTF_GATEWAY) {
2628                 /*
2629                  * nd_rd->nd_rd_target must be a link-local address in
2630                  * better router cases.
2631                  */
2632                 if (!router_ll6)
2633                         goto fail;
2634                 bcopy(router_ll6, &nd_rd->nd_rd_target,
2635                     sizeof(nd_rd->nd_rd_target));
2636                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2637                     sizeof(nd_rd->nd_rd_dst));
2638         } else {
2639                 /* make sure redtgt == reddst */
2640                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
2641                     sizeof(nd_rd->nd_rd_target));
2642                 bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
2643                     sizeof(nd_rd->nd_rd_dst));
2644         }
2645
2646         p = (u_char *)(nd_rd + 1);
2647
2648         if (!router_ll6)
2649                 goto nolladdropt;
2650
2651         {
2652                 /* target lladdr option */
2653                 int len;
2654                 struct nd_opt_hdr *nd_opt;
2655                 char *lladdr;
2656
2657                 IF_AFDATA_RLOCK(ifp);
2658                 ln = nd6_lookup(router_ll6, 0, ifp);
2659                 IF_AFDATA_RUNLOCK(ifp);
2660                 if (ln == NULL)
2661                         goto nolladdropt;
2662
2663                 len = sizeof(*nd_opt) + ifp->if_addrlen;
2664                 len = (len + 7) & ~7;   /* round by 8 */
2665                 /* safety check */
2666                 if (len + (p - (u_char *)ip6) > maxlen)
2667                         goto nolladdropt;
2668
2669                 if (ln->la_flags & LLE_VALID) {
2670                         nd_opt = (struct nd_opt_hdr *)p;
2671                         nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
2672                         nd_opt->nd_opt_len = len >> 3;
2673                         lladdr = (char *)(nd_opt + 1);
2674                         bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
2675                         p += len;
2676                 }
2677         }
2678 nolladdropt:
2679         if (ln != NULL)
2680                 LLE_RUNLOCK(ln);
2681
2682         m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2683
2684         /* just to be safe */
2685 #ifdef M_DECRYPTED      /*not openbsd*/
2686         if (m0->m_flags & M_DECRYPTED)
2687                 goto noredhdropt;
2688 #endif
2689         if (p - (u_char *)ip6 > maxlen)
2690                 goto noredhdropt;
2691
2692         {
2693                 /* redirected header option */
2694                 int len;
2695                 struct nd_opt_rd_hdr *nd_opt_rh;
2696
2697                 /*
2698                  * compute the maximum size for icmp6 redirect header option.
2699                  * XXX room for auth header?
2700                  */
2701                 len = maxlen - (p - (u_char *)ip6);
2702                 len &= ~7;
2703
2704                 /* This is just for simplicity. */
2705                 if (m0->m_pkthdr.len != m0->m_len) {
2706                         if (m0->m_next) {
2707                                 m_freem(m0->m_next);
2708                                 m0->m_next = NULL;
2709                         }
2710                         m0->m_pkthdr.len = m0->m_len;
2711                 }
2712
2713                 /*
2714                  * Redirected header option spec (RFC2461 4.6.3) talks nothing
2715                  * about padding/truncate rule for the original IP packet.
2716                  * From the discussion on IPv6imp in Feb 1999,
2717                  * the consensus was:
2718                  * - "attach as much as possible" is the goal
2719                  * - pad if not aligned (original size can be guessed by
2720                  *   original ip6 header)
2721                  * Following code adds the padding if it is simple enough,
2722                  * and truncates if not.
2723                  */
2724                 if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
2725                         panic("assumption failed in %s:%d", __FILE__,
2726                             __LINE__);
2727
2728                 if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
2729                         /* not enough room, truncate */
2730                         m0->m_pkthdr.len = m0->m_len = len -
2731                             sizeof(*nd_opt_rh);
2732                 } else {
2733                         /* enough room, pad or truncate */
2734                         size_t extra;
2735
2736                         extra = m0->m_pkthdr.len % 8;
2737                         if (extra) {
2738                                 /* pad if easy enough, truncate if not */
2739                                 if (8 - extra <= M_TRAILINGSPACE(m0)) {
2740                                         /* pad */
2741                                         m0->m_len += (8 - extra);
2742                                         m0->m_pkthdr.len += (8 - extra);
2743                                 } else {
2744                                         /* truncate */
2745                                         m0->m_pkthdr.len -= extra;
2746                                         m0->m_len -= extra;
2747                                 }
2748                         }
2749                         len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
2750                         m0->m_pkthdr.len = m0->m_len = len -
2751                             sizeof(*nd_opt_rh);
2752                 }
2753
2754                 nd_opt_rh = (struct nd_opt_rd_hdr *)p;
2755                 bzero(nd_opt_rh, sizeof(*nd_opt_rh));
2756                 nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
2757                 nd_opt_rh->nd_opt_rh_len = len >> 3;
2758                 p += sizeof(*nd_opt_rh);
2759                 m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
2760
2761                 /* connect m0 to m */
2762                 m_tag_delete_chain(m0, NULL);
2763                 m0->m_flags &= ~M_PKTHDR;
2764                 m->m_next = m0;
2765                 m->m_pkthdr.len = m->m_len + m0->m_len;
2766                 m0 = NULL;
2767         }
2768 noredhdropt:;
2769         if (m0) {
2770                 m_freem(m0);
2771                 m0 = NULL;
2772         }
2773
2774         /* XXX: clear embedded link IDs in the inner header */
2775         in6_clearscope(&sip6->ip6_src);
2776         in6_clearscope(&sip6->ip6_dst);
2777         in6_clearscope(&nd_rd->nd_rd_target);
2778         in6_clearscope(&nd_rd->nd_rd_dst);
2779
2780         ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
2781
2782         nd_rd->nd_rd_cksum = 0;
2783         nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
2784             sizeof(*ip6), ntohs(ip6->ip6_plen));
2785
2786         if (send_sendso_input_hook != NULL) {
2787                 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING, sizeof(unsigned short),
2788                         M_NOWAIT);
2789                 if (mtag == NULL)
2790                         goto fail;
2791                 *(unsigned short *)(mtag + 1) = nd_rd->nd_rd_type;
2792                 m_tag_prepend(m, mtag);
2793         }
2794
2795         /* send the packet to outside... */
2796         ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
2797         if (outif) {
2798                 icmp6_ifstat_inc(outif, ifs6_out_msg);
2799                 icmp6_ifstat_inc(outif, ifs6_out_redirect);
2800         }
2801         ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);
2802
2803         return;
2804
2805 fail:
2806         if (m)
2807                 m_freem(m);
2808         if (m0)
2809                 m_freem(m0);
2810 }
2811
2812 /*
2813  * ICMPv6 socket option processing.
2814  */
2815 int
2816 icmp6_ctloutput(struct socket *so, struct sockopt *sopt)
2817 {
2818         int error = 0;
2819         int optlen;
2820         struct inpcb *inp = sotoinpcb(so);
2821         int level, op, optname;
2822
2823         if (sopt) {
2824                 level = sopt->sopt_level;
2825                 op = sopt->sopt_dir;
2826                 optname = sopt->sopt_name;
2827                 optlen = sopt->sopt_valsize;
2828         } else
2829                 level = op = optname = optlen = 0;
2830
2831         if (level != IPPROTO_ICMPV6) {
2832                 return EINVAL;
2833         }
2834
2835         switch (op) {
2836         case PRCO_SETOPT:
2837                 switch (optname) {
2838                 case ICMP6_FILTER:
2839                     {
2840                         struct icmp6_filter ic6f;
2841
2842                         if (optlen != sizeof(ic6f)) {
2843                                 error = EMSGSIZE;
2844                                 break;
2845                         }
2846                         error = sooptcopyin(sopt, &ic6f, optlen, optlen);
2847                         if (error == 0) {
2848                                 INP_WLOCK(inp);
2849                                 *inp->in6p_icmp6filt = ic6f;
2850                                 INP_WUNLOCK(inp);
2851                         }
2852                         break;
2853                     }
2854
2855                 default:
2856                         error = ENOPROTOOPT;
2857                         break;
2858                 }
2859                 break;
2860
2861         case PRCO_GETOPT:
2862                 switch (optname) {
2863                 case ICMP6_FILTER:
2864                     {
2865                         struct icmp6_filter ic6f;
2866
2867                         INP_RLOCK(inp);
2868                         ic6f = *inp->in6p_icmp6filt;
2869                         INP_RUNLOCK(inp);
2870                         error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
2871                         break;
2872                     }
2873
2874                 default:
2875                         error = ENOPROTOOPT;
2876                         break;
2877                 }
2878                 break;
2879         }
2880
2881         return (error);
2882 }
2883
2884 /*
2885  * Perform rate limit check.
2886  * Returns 0 if it is okay to send the icmp6 packet.
2887  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
2888  * limitation.
2889  *
2890  * XXX per-destination/type check necessary?
2891  *
2892  * dst - not used at this moment
2893  * type - not used at this moment
2894  * code - not used at this moment
2895  */
2896 static int
2897 icmp6_ratelimit(const struct in6_addr *dst, const int type,
2898     const int code)
2899 {
2900         int ret;
2901
2902         ret = 0;        /* okay to send */
2903
2904         /* PPS limit */
2905         if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
2906             V_icmp6errppslim)) {
2907                 /* The packet is subject to rate limit */
2908                 ret++;
2909         }
2910
2911         return ret;
2912 }