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icmp6.c revision 1.115
      1 /*	$NetBSD: icmp6.c,v 1.115 2006/03/05 23:47:08 rpaulo Exp $	*/
      2 /*	$KAME: icmp6.c,v 1.217 2001/06/20 15:03:29 jinmei Exp $	*/
      3 
      4 /*
      5  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. Neither the name of the project nor the names of its contributors
     17  *    may be used to endorse or promote products derived from this software
     18  *    without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     30  * SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Copyright (c) 1982, 1986, 1988, 1993
     35  *	The Regents of the University of California.  All rights reserved.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  * 3. Neither the name of the University nor the names of its contributors
     46  *    may be used to endorse or promote products derived from this software
     47  *    without specific prior written permission.
     48  *
     49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     59  * SUCH DAMAGE.
     60  *
     61  *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
     62  */
     63 
     64 #include <sys/cdefs.h>
     65 __KERNEL_RCSID(0, "$NetBSD: icmp6.c,v 1.115 2006/03/05 23:47:08 rpaulo Exp $");
     66 
     67 #include "opt_inet.h"
     68 #include "opt_ipsec.h"
     69 
     70 #include <sys/param.h>
     71 #include <sys/systm.h>
     72 #include <sys/malloc.h>
     73 #include <sys/mbuf.h>
     74 #include <sys/protosw.h>
     75 #include <sys/socket.h>
     76 #include <sys/socketvar.h>
     77 #include <sys/time.h>
     78 #include <sys/kernel.h>
     79 #include <sys/syslog.h>
     80 #include <sys/domain.h>
     81 #include <sys/sysctl.h>
     82 
     83 #include <net/if.h>
     84 #include <net/route.h>
     85 #include <net/if_dl.h>
     86 #include <net/if_types.h>
     87 
     88 #include <netinet/in.h>
     89 #include <netinet/in_var.h>
     90 #include <netinet/ip6.h>
     91 #include <netinet6/ip6_var.h>
     92 #include <netinet/icmp6.h>
     93 #include <netinet6/mld6_var.h>
     94 #include <netinet6/in6_pcb.h>
     95 #include <netinet6/nd6.h>
     96 #include <netinet6/in6_ifattach.h>
     97 #include <netinet6/ip6protosw.h>
     98 #include <netinet6/scope6_var.h>
     99 
    100 #ifdef IPSEC
    101 #include <netinet6/ipsec.h>
    102 #include <netkey/key.h>
    103 #endif
    104 
    105 #include "faith.h"
    106 #if defined(NFAITH) && 0 < NFAITH
    107 #include <net/if_faith.h>
    108 #endif
    109 
    110 #include <net/net_osdep.h>
    111 
    112 extern struct domain inet6domain;
    113 
    114 struct icmp6stat icmp6stat;
    115 
    116 extern struct inpcbtable raw6cbtable;
    117 extern int icmp6errppslim;
    118 static int icmp6errpps_count = 0;
    119 static struct timeval icmp6errppslim_last;
    120 extern int icmp6_nodeinfo;
    121 
    122 /*
    123  * List of callbacks to notify when Path MTU changes are made.
    124  */
    125 struct icmp6_mtudisc_callback {
    126 	LIST_ENTRY(icmp6_mtudisc_callback) mc_list;
    127 	void (*mc_func) __P((struct in6_addr *));
    128 };
    129 
    130 LIST_HEAD(, icmp6_mtudisc_callback) icmp6_mtudisc_callbacks =
    131     LIST_HEAD_INITIALIZER(&icmp6_mtudisc_callbacks);
    132 
    133 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
    134 extern int pmtu_expire;
    135 
    136 /* XXX do these values make any sense? */
    137 static int icmp6_mtudisc_hiwat = 1280;
    138 static int icmp6_mtudisc_lowat = 256;
    139 
    140 /*
    141  * keep track of # of redirect routes.
    142  */
    143 static struct rttimer_queue *icmp6_redirect_timeout_q = NULL;
    144 
    145 /* XXX experimental, turned off */
    146 static int icmp6_redirect_hiwat = -1;
    147 static int icmp6_redirect_lowat = -1;
    148 
    149 static void icmp6_errcount __P((struct icmp6errstat *, int, int));
    150 static int icmp6_rip6_input __P((struct mbuf **, int));
    151 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
    152 static const char *icmp6_redirect_diag __P((struct in6_addr *,
    153 	struct in6_addr *, struct in6_addr *));
    154 static struct mbuf *ni6_input __P((struct mbuf *, int));
    155 static struct mbuf *ni6_nametodns __P((const char *, int, int));
    156 static int ni6_dnsmatch __P((const char *, int, const char *, int));
    157 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
    158 			  struct ifnet **, char *));
    159 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
    160 				struct ifnet *, int));
    161 static int icmp6_notify_error __P((struct mbuf *, int, int, int));
    162 static struct rtentry *icmp6_mtudisc_clone __P((struct sockaddr *));
    163 static void icmp6_mtudisc_timeout __P((struct rtentry *, struct rttimer *));
    164 static void icmp6_redirect_timeout __P((struct rtentry *, struct rttimer *));
    165 
    166 void
    167 icmp6_init()
    168 {
    169 	mld_init();
    170 	icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
    171 	icmp6_redirect_timeout_q = rt_timer_queue_create(icmp6_redirtimeout);
    172 }
    173 
    174 static void
    175 icmp6_errcount(stat, type, code)
    176 	struct icmp6errstat *stat;
    177 	int type, code;
    178 {
    179 	switch (type) {
    180 	case ICMP6_DST_UNREACH:
    181 		switch (code) {
    182 		case ICMP6_DST_UNREACH_NOROUTE:
    183 			stat->icp6errs_dst_unreach_noroute++;
    184 			return;
    185 		case ICMP6_DST_UNREACH_ADMIN:
    186 			stat->icp6errs_dst_unreach_admin++;
    187 			return;
    188 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
    189 			stat->icp6errs_dst_unreach_beyondscope++;
    190 			return;
    191 		case ICMP6_DST_UNREACH_ADDR:
    192 			stat->icp6errs_dst_unreach_addr++;
    193 			return;
    194 		case ICMP6_DST_UNREACH_NOPORT:
    195 			stat->icp6errs_dst_unreach_noport++;
    196 			return;
    197 		}
    198 		break;
    199 	case ICMP6_PACKET_TOO_BIG:
    200 		stat->icp6errs_packet_too_big++;
    201 		return;
    202 	case ICMP6_TIME_EXCEEDED:
    203 		switch (code) {
    204 		case ICMP6_TIME_EXCEED_TRANSIT:
    205 			stat->icp6errs_time_exceed_transit++;
    206 			return;
    207 		case ICMP6_TIME_EXCEED_REASSEMBLY:
    208 			stat->icp6errs_time_exceed_reassembly++;
    209 			return;
    210 		}
    211 		break;
    212 	case ICMP6_PARAM_PROB:
    213 		switch (code) {
    214 		case ICMP6_PARAMPROB_HEADER:
    215 			stat->icp6errs_paramprob_header++;
    216 			return;
    217 		case ICMP6_PARAMPROB_NEXTHEADER:
    218 			stat->icp6errs_paramprob_nextheader++;
    219 			return;
    220 		case ICMP6_PARAMPROB_OPTION:
    221 			stat->icp6errs_paramprob_option++;
    222 			return;
    223 		}
    224 		break;
    225 	case ND_REDIRECT:
    226 		stat->icp6errs_redirect++;
    227 		return;
    228 	}
    229 	stat->icp6errs_unknown++;
    230 }
    231 
    232 /*
    233  * Register a Path MTU Discovery callback.
    234  */
    235 void
    236 icmp6_mtudisc_callback_register(func)
    237 	void (*func) __P((struct in6_addr *));
    238 {
    239 	struct icmp6_mtudisc_callback *mc;
    240 
    241 	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
    242 	     mc = LIST_NEXT(mc, mc_list)) {
    243 		if (mc->mc_func == func)
    244 			return;
    245 	}
    246 
    247 	mc = malloc(sizeof(*mc), M_PCB, M_NOWAIT);
    248 	if (mc == NULL)
    249 		panic("icmp6_mtudisc_callback_register");
    250 
    251 	mc->mc_func = func;
    252 	LIST_INSERT_HEAD(&icmp6_mtudisc_callbacks, mc, mc_list);
    253 }
    254 
    255 /*
    256  * A wrapper function for icmp6_error() necessary when the erroneous packet
    257  * may not contain enough scope zone information.
    258  */
    259 void
    260 icmp6_error2(m, type, code, param, ifp)
    261 	struct mbuf *m;
    262 	int type, code, param;
    263 	struct ifnet *ifp;
    264 {
    265 	struct ip6_hdr *ip6;
    266 
    267 	if (ifp == NULL)
    268 		return;
    269 
    270 	if (m->m_len < sizeof(struct ip6_hdr)) {
    271 		m = m_pullup(m, sizeof(struct ip6_hdr));
    272 		if (m == NULL)
    273 			return;
    274 	}
    275 
    276 	ip6 = mtod(m, struct ip6_hdr *);
    277 
    278 	if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
    279 		return;
    280 	if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
    281 		return;
    282 
    283 	icmp6_error(m, type, code, param);
    284 }
    285 
    286 /*
    287  * Generate an error packet of type error in response to bad IP6 packet.
    288  */
    289 void
    290 icmp6_error(m, type, code, param)
    291 	struct mbuf *m;
    292 	int type, code, param;
    293 {
    294 	struct ip6_hdr *oip6, *nip6;
    295 	struct icmp6_hdr *icmp6;
    296 	u_int preplen;
    297 	int off;
    298 	int nxt;
    299 
    300 	icmp6stat.icp6s_error++;
    301 
    302 	/* count per-type-code statistics */
    303 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, type, code);
    304 
    305 	if (m->m_flags & M_DECRYPTED) {
    306 		icmp6stat.icp6s_canterror++;
    307 		goto freeit;
    308 	}
    309 
    310 	if (m->m_len < sizeof(struct ip6_hdr)) {
    311 		m = m_pullup(m, sizeof(struct ip6_hdr));
    312 		if (m == NULL)
    313 			return;
    314 	}
    315 	oip6 = mtod(m, struct ip6_hdr *);
    316 
    317 	/*
    318 	 * If the destination address of the erroneous packet is a multicast
    319 	 * address, or the packet was sent using link-layer multicast,
    320 	 * we should basically suppress sending an error (RFC 2463, Section
    321 	 * 2.4).
    322 	 * We have two exceptions (the item e.2 in that section):
    323 	 * - the Pakcet Too Big message can be sent for path MTU discovery.
    324 	 * - the Parameter Problem Message that can be allowed an icmp6 error
    325 	 *   in the option type field.  This check has been done in
    326 	 *   ip6_unknown_opt(), so we can just check the type and code.
    327 	 */
    328 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
    329 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
    330 	    (type != ICMP6_PACKET_TOO_BIG &&
    331 	     (type != ICMP6_PARAM_PROB ||
    332 	      code != ICMP6_PARAMPROB_OPTION)))
    333 		goto freeit;
    334 
    335 	/*
    336 	 * RFC 2463, 2.4 (e.5): source address check.
    337 	 * XXX: the case of anycast source?
    338 	 */
    339 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
    340 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
    341 		goto freeit;
    342 
    343 	/*
    344 	 * If we are about to send ICMPv6 against ICMPv6 error/redirect,
    345 	 * don't do it.
    346 	 */
    347 	nxt = -1;
    348 	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
    349 	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
    350 		struct icmp6_hdr *icp;
    351 
    352 		IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
    353 			sizeof(*icp));
    354 		if (icp == NULL) {
    355 			icmp6stat.icp6s_tooshort++;
    356 			return;
    357 		}
    358 		if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
    359 		    icp->icmp6_type == ND_REDIRECT) {
    360 			/*
    361 			 * ICMPv6 error
    362 			 * Special case: for redirect (which is
    363 			 * informational) we must not send icmp6 error.
    364 			 */
    365 			icmp6stat.icp6s_canterror++;
    366 			goto freeit;
    367 		} else {
    368 			/* ICMPv6 informational - send the error */
    369 		}
    370 	}
    371 #if 0 /* controversial */
    372 	else if (off >= 0 && nxt == IPPROTO_ESP) {
    373 		/*
    374 		 * It could be ICMPv6 error inside ESP.  Take a safer side,
    375 		 * don't respond.
    376 		 */
    377 		icmp6stat.icp6s_canterror++;
    378 		goto freeit;
    379 	}
    380 #endif
    381 	else {
    382 		/* non-ICMPv6 - send the error */
    383 	}
    384 
    385 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
    386 
    387 	/* Finally, do rate limitation check. */
    388 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
    389 		icmp6stat.icp6s_toofreq++;
    390 		goto freeit;
    391 	}
    392 
    393 	/*
    394 	 * OK, ICMP6 can be generated.
    395 	 */
    396 
    397 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
    398 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
    399 
    400 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
    401 	M_PREPEND(m, preplen, M_DONTWAIT);
    402 	if (m && m->m_len < preplen)
    403 		m = m_pullup(m, preplen);
    404 	if (m == NULL) {
    405 		nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
    406 		return;
    407 	}
    408 
    409 	nip6 = mtod(m, struct ip6_hdr *);
    410 	nip6->ip6_src  = oip6->ip6_src;
    411 	nip6->ip6_dst  = oip6->ip6_dst;
    412 
    413 	in6_clearscope(&oip6->ip6_src);
    414 	in6_clearscope(&oip6->ip6_dst);
    415 
    416 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
    417 	icmp6->icmp6_type = type;
    418 	icmp6->icmp6_code = code;
    419 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
    420 
    421 	/*
    422 	 * icmp6_reflect() is designed to be in the input path.
    423 	 * icmp6_error() can be called from both input and output path,
    424 	 * and if we are in output path rcvif could contain bogus value.
    425 	 * clear m->m_pkthdr.rcvif for safety, we should have enough scope
    426 	 * information in ip header (nip6).
    427 	 */
    428 	m->m_pkthdr.rcvif = NULL;
    429 
    430 	icmp6stat.icp6s_outhist[type]++;
    431 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */
    432 
    433 	return;
    434 
    435   freeit:
    436 	/*
    437 	 * If we can't tell whether or not we can generate ICMP6, free it.
    438 	 */
    439 	m_freem(m);
    440 }
    441 
    442 /*
    443  * Process a received ICMP6 message.
    444  */
    445 int
    446 icmp6_input(mp, offp, proto)
    447 	struct mbuf **mp;
    448 	int *offp, proto;
    449 {
    450 	struct mbuf *m = *mp, *n;
    451 	struct ip6_hdr *ip6, *nip6;
    452 	struct icmp6_hdr *icmp6, *nicmp6;
    453 	int off = *offp;
    454 	int icmp6len = m->m_pkthdr.len - *offp;
    455 	int code, sum, noff;
    456 
    457 	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
    458 
    459 	/*
    460 	 * Locate icmp6 structure in mbuf, and check
    461 	 * that not corrupted and of at least minimum length
    462 	 */
    463 
    464 	ip6 = mtod(m, struct ip6_hdr *);
    465 	if (icmp6len < sizeof(struct icmp6_hdr)) {
    466 		icmp6stat.icp6s_tooshort++;
    467 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
    468 		goto freeit;
    469 	}
    470 
    471 	/*
    472 	 * calculate the checksum
    473 	 */
    474 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
    475 	if (icmp6 == NULL) {
    476 		icmp6stat.icp6s_tooshort++;
    477 		/* m is invalid */
    478 		/*icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);*/
    479 		return IPPROTO_DONE;
    480 	}
    481 	KASSERT(IP6_HDR_ALIGNED_P(icmp6));
    482 	code = icmp6->icmp6_code;
    483 
    484 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
    485 		nd6log((LOG_ERR,
    486 		    "ICMP6 checksum error(%d|%x) %s\n",
    487 		    icmp6->icmp6_type, sum, ip6_sprintf(&ip6->ip6_src)));
    488 		icmp6stat.icp6s_checksum++;
    489 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
    490 		goto freeit;
    491 	}
    492 
    493 #if defined(NFAITH) && 0 < NFAITH
    494 	if (faithprefix(&ip6->ip6_dst)) {
    495 		/*
    496 		 * Deliver very specific ICMP6 type only.
    497 		 * This is important to deliver TOOBIG.  Otherwise PMTUD
    498 		 * will not work.
    499 		 */
    500 		switch (icmp6->icmp6_type) {
    501 		case ICMP6_DST_UNREACH:
    502 		case ICMP6_PACKET_TOO_BIG:
    503 		case ICMP6_TIME_EXCEEDED:
    504 			break;
    505 		default:
    506 			goto freeit;
    507 		}
    508 	}
    509 #endif
    510 
    511 	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
    512 
    513 	switch (icmp6->icmp6_type) {
    514 	case ICMP6_DST_UNREACH:
    515 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
    516 		switch (code) {
    517 		case ICMP6_DST_UNREACH_NOROUTE:
    518 			code = PRC_UNREACH_NET;
    519 			break;
    520 		case ICMP6_DST_UNREACH_ADMIN:
    521 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
    522 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
    523 			break;
    524 		case ICMP6_DST_UNREACH_ADDR:
    525 			code = PRC_HOSTDEAD;
    526 			break;
    527 #ifdef COMPAT_RFC1885
    528 		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
    529 			code = PRC_UNREACH_SRCFAIL;
    530 			break;
    531 #else
    532 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
    533 			/* I mean "source address was incorrect." */
    534 			code = PRC_UNREACH_NET;
    535 			break;
    536 #endif
    537 		case ICMP6_DST_UNREACH_NOPORT:
    538 			code = PRC_UNREACH_PORT;
    539 			break;
    540 		default:
    541 			goto badcode;
    542 		}
    543 		goto deliver;
    544 
    545 	case ICMP6_PACKET_TOO_BIG:
    546 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
    547 
    548 		code = PRC_MSGSIZE;
    549 
    550 		/*
    551 		 * Updating the path MTU will be done after examining
    552 		 * intermediate extension headers.
    553 		 */
    554 		goto deliver;
    555 
    556 	case ICMP6_TIME_EXCEEDED:
    557 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
    558 		switch (code) {
    559 		case ICMP6_TIME_EXCEED_TRANSIT:
    560 			code = PRC_TIMXCEED_INTRANS;
    561 			break;
    562 		case ICMP6_TIME_EXCEED_REASSEMBLY:
    563 			code = PRC_TIMXCEED_REASS;
    564 			break;
    565 		default:
    566 			goto badcode;
    567 		}
    568 		goto deliver;
    569 
    570 	case ICMP6_PARAM_PROB:
    571 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
    572 		switch (code) {
    573 		case ICMP6_PARAMPROB_NEXTHEADER:
    574 			code = PRC_UNREACH_PROTOCOL;
    575 			break;
    576 		case ICMP6_PARAMPROB_HEADER:
    577 		case ICMP6_PARAMPROB_OPTION:
    578 			code = PRC_PARAMPROB;
    579 			break;
    580 		default:
    581 			goto badcode;
    582 		}
    583 		goto deliver;
    584 
    585 	case ICMP6_ECHO_REQUEST:
    586 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
    587 		if (code != 0)
    588 			goto badcode;
    589 		/*
    590 		 * Copy mbuf to send to two data paths: userland socket(s),
    591 		 * and to the querier (echo reply).
    592 		 * m: a copy for socket, n: a copy for querier
    593 		 */
    594 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    595 			/* Give up local */
    596 			n = m;
    597 			m = NULL;
    598 			goto deliverecho;
    599 		}
    600 		/*
    601 		 * If the first mbuf is shared, or the first mbuf is too short,
    602 		 * copy the first part of the data into a fresh mbuf.
    603 		 * Otherwise, we will wrongly overwrite both copies.
    604 		 */
    605 		if ((n->m_flags & M_EXT) != 0 ||
    606 		    n->m_len < off + sizeof(struct icmp6_hdr)) {
    607 			struct mbuf *n0 = n;
    608 			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
    609 
    610 			/*
    611 			 * Prepare an internal mbuf.  m_pullup() doesn't
    612 			 * always copy the length we specified.
    613 			 */
    614 			if (maxlen >= MCLBYTES) {
    615 				/* Give up remote */
    616 				m_freem(n0);
    617 				break;
    618 			}
    619 			MGETHDR(n, M_DONTWAIT, n0->m_type);
    620 			if (n && maxlen >= MHLEN) {
    621 				MCLGET(n, M_DONTWAIT);
    622 				if ((n->m_flags & M_EXT) == 0) {
    623 					m_free(n);
    624 					n = NULL;
    625 				}
    626 			}
    627 			if (n == NULL) {
    628 				/* Give up local */
    629 				m_freem(n0);
    630 				n = m;
    631 				m = NULL;
    632 				goto deliverecho;
    633 			}
    634 			M_MOVE_PKTHDR(n, n0);
    635 			/*
    636 			 * Copy IPv6 and ICMPv6 only.
    637 			 */
    638 			nip6 = mtod(n, struct ip6_hdr *);
    639 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
    640 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
    641 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
    642 			noff = sizeof(struct ip6_hdr);
    643 			n->m_len = noff + sizeof(struct icmp6_hdr);
    644 			/*
    645 			 * Adjust mbuf.  ip6_plen will be adjusted in
    646 			 * ip6_output().
    647 			 * n->m_pkthdr.len == n0->m_pkthdr.len at this point.
    648 			 */
    649 			n->m_pkthdr.len += noff + sizeof(struct icmp6_hdr);
    650 			n->m_pkthdr.len -= (off + sizeof(struct icmp6_hdr));
    651 			m_adj(n0, off + sizeof(struct icmp6_hdr));
    652 			n->m_next = n0;
    653 		} else {
    654 	 deliverecho:
    655 			nip6 = mtod(n, struct ip6_hdr *);
    656 			nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
    657 			noff = off;
    658 		}
    659 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
    660 		nicmp6->icmp6_code = 0;
    661 		if (n) {
    662 			icmp6stat.icp6s_reflect++;
    663 			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
    664 			icmp6_reflect(n, noff);
    665 		}
    666 		if (!m)
    667 			goto freeit;
    668 		break;
    669 
    670 	case ICMP6_ECHO_REPLY:
    671 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
    672 		if (code != 0)
    673 			goto badcode;
    674 		break;
    675 
    676 	case MLD_LISTENER_QUERY:
    677 	case MLD_LISTENER_REPORT:
    678 		if (icmp6len < sizeof(struct mld_hdr))
    679 			goto badlen;
    680 		if (icmp6->icmp6_type == MLD_LISTENER_QUERY) /* XXX: ugly... */
    681 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
    682 		else
    683 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
    684 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    685 			/* give up local */
    686 			mld_input(m, off);
    687 			m = NULL;
    688 			goto freeit;
    689 		}
    690 		mld_input(n, off);
    691 		/* m stays. */
    692 		break;
    693 
    694 	case MLD_LISTENER_DONE:
    695 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
    696 		if (icmp6len < sizeof(struct mld_hdr))	/* necessary? */
    697 			goto badlen;
    698 		break;		/* nothing to be done in kernel */
    699 
    700 	case MLD_MTRACE_RESP:
    701 	case MLD_MTRACE:
    702 		/* XXX: these two are experimental.  not officially defined. */
    703 		/* XXX: per-interface statistics? */
    704 		break;		/* just pass it to applications */
    705 
    706 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
    707 	    {
    708 		enum { WRU, FQDN } mode;
    709 
    710 		if (!icmp6_nodeinfo)
    711 			break;
    712 
    713 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
    714 			mode = WRU;
    715 		else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
    716 			mode = FQDN;
    717 		else
    718 			goto badlen;
    719 
    720 		if (mode == FQDN) {
    721 			n = m_copym(m, 0, M_COPYALL, M_DONTWAIT);
    722 			if (n)
    723 				n = ni6_input(n, off);
    724 			/* XXX meaningless if n == NULL */
    725 			noff = sizeof(struct ip6_hdr);
    726 		} else {
    727 			u_char *p;
    728 			int maxlen, maxhlen;
    729 
    730 			if ((icmp6_nodeinfo & 5) != 5)
    731 				break;
    732 
    733 			if (code != 0)
    734 				goto badcode;
    735 			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
    736 			if (maxlen >= MCLBYTES) {
    737 				/* Give up remote */
    738 				break;
    739 			}
    740 			MGETHDR(n, M_DONTWAIT, m->m_type);
    741 			if (n && maxlen > MHLEN) {
    742 				MCLGET(n, M_DONTWAIT);
    743 				if ((n->m_flags & M_EXT) == 0) {
    744 					m_free(n);
    745 					n = NULL;
    746 				}
    747 			}
    748 			if (n == NULL) {
    749 				/* Give up remote */
    750 				break;
    751 			}
    752 			n->m_pkthdr.rcvif = NULL;
    753 			n->m_len = 0;
    754 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
    755 			if (maxhlen > hostnamelen)
    756 				maxhlen = hostnamelen;
    757 			/*
    758 			 * Copy IPv6 and ICMPv6 only.
    759 			 */
    760 			nip6 = mtod(n, struct ip6_hdr *);
    761 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
    762 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
    763 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
    764 			p = (u_char *)(nicmp6 + 1);
    765 			bzero(p, 4);
    766 			bcopy(hostname, p + 4, maxhlen); /* meaningless TTL */
    767 			noff = sizeof(struct ip6_hdr);
    768 			M_COPY_PKTHDR(n, m); /* just for rcvif */
    769 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
    770 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
    771 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
    772 			nicmp6->icmp6_code = 0;
    773 		}
    774 #undef hostnamelen
    775 		if (n) {
    776 			icmp6stat.icp6s_reflect++;
    777 			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
    778 			icmp6_reflect(n, noff);
    779 		}
    780 		break;
    781 	    }
    782 
    783 	case ICMP6_WRUREPLY:
    784 		if (code != 0)
    785 			goto badcode;
    786 		break;
    787 
    788 	case ND_ROUTER_SOLICIT:
    789 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
    790 		if (code != 0)
    791 			goto badcode;
    792 		if (icmp6len < sizeof(struct nd_router_solicit))
    793 			goto badlen;
    794 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    795 			/* give up local */
    796 			nd6_rs_input(m, off, icmp6len);
    797 			m = NULL;
    798 			goto freeit;
    799 		}
    800 		nd6_rs_input(n, off, icmp6len);
    801 		/* m stays. */
    802 		break;
    803 
    804 	case ND_ROUTER_ADVERT:
    805 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
    806 		if (code != 0)
    807 			goto badcode;
    808 		if (icmp6len < sizeof(struct nd_router_advert))
    809 			goto badlen;
    810 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    811 			/* give up local */
    812 			nd6_ra_input(m, off, icmp6len);
    813 			m = NULL;
    814 			goto freeit;
    815 		}
    816 		nd6_ra_input(n, off, icmp6len);
    817 		/* m stays. */
    818 		break;
    819 
    820 	case ND_NEIGHBOR_SOLICIT:
    821 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, 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_DONTWAIT)) == NULL) {
    827 			/* give up local */
    828 			nd6_ns_input(m, off, icmp6len);
    829 			m = NULL;
    830 			goto freeit;
    831 		}
    832 		nd6_ns_input(n, off, icmp6len);
    833 		/* m stays. */
    834 		break;
    835 
    836 	case ND_NEIGHBOR_ADVERT:
    837 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
    838 		if (code != 0)
    839 			goto badcode;
    840 		if (icmp6len < sizeof(struct nd_neighbor_advert))
    841 			goto badlen;
    842 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    843 			/* give up local */
    844 			nd6_na_input(m, off, icmp6len);
    845 			m = NULL;
    846 			goto freeit;
    847 		}
    848 		nd6_na_input(n, off, icmp6len);
    849 		/* m stays. */
    850 		break;
    851 
    852 	case ND_REDIRECT:
    853 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
    854 		if (code != 0)
    855 			goto badcode;
    856 		if (icmp6len < sizeof(struct nd_redirect))
    857 			goto badlen;
    858 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    859 			/* give up local */
    860 			icmp6_redirect_input(m, off);
    861 			m = NULL;
    862 			goto freeit;
    863 		}
    864 		icmp6_redirect_input(n, off);
    865 		/* m stays. */
    866 		break;
    867 
    868 	case ICMP6_ROUTER_RENUMBERING:
    869 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
    870 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
    871 			goto badcode;
    872 		if (icmp6len < sizeof(struct icmp6_router_renum))
    873 			goto badlen;
    874 		break;
    875 
    876 	default:
    877 		nd6log((LOG_DEBUG,
    878 		    "icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
    879 		    icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
    880 		    ip6_sprintf(&ip6->ip6_dst),
    881 		    m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0));
    882 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
    883 			/* ICMPv6 error: MUST deliver it by spec... */
    884 			code = PRC_NCMDS;
    885 			/* deliver */
    886 		} else {
    887 			/* ICMPv6 informational: MUST not deliver */
    888 			break;
    889 		}
    890 	deliver:
    891 		if (icmp6_notify_error(m, off, icmp6len, code)) {
    892 			/* In this case, m should've been freed. */
    893 			return (IPPROTO_DONE);
    894 		}
    895 		break;
    896 
    897 	badcode:
    898 		icmp6stat.icp6s_badcode++;
    899 		break;
    900 
    901 	badlen:
    902 		icmp6stat.icp6s_badlen++;
    903 		break;
    904 	}
    905 
    906 	/* deliver the packet to appropriate sockets */
    907 	icmp6_rip6_input(&m, *offp);
    908 
    909 	return IPPROTO_DONE;
    910 
    911  freeit:
    912 	m_freem(m);
    913 	return IPPROTO_DONE;
    914 }
    915 
    916 static int
    917 icmp6_notify_error(m, off, icmp6len, code)
    918 	struct mbuf *m;
    919 	int off, icmp6len;
    920 {
    921 	struct icmp6_hdr *icmp6;
    922 	struct ip6_hdr *eip6;
    923 	u_int32_t notifymtu;
    924 	struct sockaddr_in6 icmp6src, icmp6dst;
    925 
    926 	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
    927 		icmp6stat.icp6s_tooshort++;
    928 		goto freeit;
    929 	}
    930 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
    931 		       sizeof(*icmp6) + sizeof(struct ip6_hdr));
    932 	if (icmp6 == NULL) {
    933 		icmp6stat.icp6s_tooshort++;
    934 		return (-1);
    935 	}
    936 	eip6 = (struct ip6_hdr *)(icmp6 + 1);
    937 
    938 	/* Detect the upper level protocol */
    939 	{
    940 		void (*ctlfunc) __P((int, struct sockaddr *, void *));
    941 		u_int8_t nxt = eip6->ip6_nxt;
    942 		int eoff = off + sizeof(struct icmp6_hdr) +
    943 			sizeof(struct ip6_hdr);
    944 		struct ip6ctlparam ip6cp;
    945 		struct in6_addr *finaldst = NULL;
    946 		int icmp6type = icmp6->icmp6_type;
    947 		struct ip6_frag *fh;
    948 		struct ip6_rthdr *rth;
    949 		struct ip6_rthdr0 *rth0;
    950 		int rthlen;
    951 
    952 		while (1) { /* XXX: should avoid infinite loop explicitly? */
    953 			struct ip6_ext *eh;
    954 
    955 			switch (nxt) {
    956 			case IPPROTO_HOPOPTS:
    957 			case IPPROTO_DSTOPTS:
    958 			case IPPROTO_AH:
    959 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
    960 					       eoff, sizeof(*eh));
    961 				if (eh == NULL) {
    962 					icmp6stat.icp6s_tooshort++;
    963 					return (-1);
    964 				}
    965 
    966 				if (nxt == IPPROTO_AH)
    967 					eoff += (eh->ip6e_len + 2) << 2;
    968 				else
    969 					eoff += (eh->ip6e_len + 1) << 3;
    970 				nxt = eh->ip6e_nxt;
    971 				break;
    972 			case IPPROTO_ROUTING:
    973 				/*
    974 				 * When the erroneous packet contains a
    975 				 * routing header, we should examine the
    976 				 * header to determine the final destination.
    977 				 * Otherwise, we can't properly update
    978 				 * information that depends on the final
    979 				 * destination (e.g. path MTU).
    980 				 */
    981 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
    982 					       eoff, sizeof(*rth));
    983 				if (rth == NULL) {
    984 					icmp6stat.icp6s_tooshort++;
    985 					return (-1);
    986 				}
    987 				rthlen = (rth->ip6r_len + 1) << 3;
    988 				/*
    989 				 * XXX: currently there is no
    990 				 * officially defined type other
    991 				 * than type-0.
    992 				 * Note that if the segment left field
    993 				 * is 0, all intermediate hops must
    994 				 * have been passed.
    995 				 */
    996 				if (rth->ip6r_segleft &&
    997 				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
    998 					int hops;
    999 
   1000 					IP6_EXTHDR_GET(rth0,
   1001 						       struct ip6_rthdr0 *, m,
   1002 						       eoff, rthlen);
   1003 					if (rth0 == NULL) {
   1004 						icmp6stat.icp6s_tooshort++;
   1005 						return (-1);
   1006 					}
   1007 					/* just ignore a bogus header */
   1008 					if ((rth0->ip6r0_len % 2) == 0 &&
   1009 					    (hops = rth0->ip6r0_len/2))
   1010 						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
   1011 				}
   1012 				eoff += rthlen;
   1013 				nxt = rth->ip6r_nxt;
   1014 				break;
   1015 			case IPPROTO_FRAGMENT:
   1016 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
   1017 					       eoff, sizeof(*fh));
   1018 				if (fh == NULL) {
   1019 					icmp6stat.icp6s_tooshort++;
   1020 					return (-1);
   1021 				}
   1022 				/*
   1023 				 * Data after a fragment header is meaningless
   1024 				 * unless it is the first fragment, but
   1025 				 * we'll go to the notify label for path MTU
   1026 				 * discovery.
   1027 				 */
   1028 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
   1029 					goto notify;
   1030 
   1031 				eoff += sizeof(struct ip6_frag);
   1032 				nxt = fh->ip6f_nxt;
   1033 				break;
   1034 			default:
   1035 				/*
   1036 				 * This case includes ESP and the No Next
   1037 				 * Header.  In such cases going to the notify
   1038 				 * label does not have any meaning
   1039 				 * (i.e. ctlfunc will be NULL), but we go
   1040 				 * anyway since we might have to update
   1041 				 * path MTU information.
   1042 				 */
   1043 				goto notify;
   1044 			}
   1045 		}
   1046 	  notify:
   1047 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
   1048 			       sizeof(*icmp6) + sizeof(struct ip6_hdr));
   1049 		if (icmp6 == NULL) {
   1050 			icmp6stat.icp6s_tooshort++;
   1051 			return (-1);
   1052 		}
   1053 
   1054 		/*
   1055 		 * retrieve parameters from the inner IPv6 header, and convert
   1056 		 * them into sockaddr structures.
   1057 		 * XXX: there is no guarantee that the source or destination
   1058 		 * addresses of the inner packet are in the same scope zone as
   1059 		 * the addresses of the icmp packet.  But there is no other
   1060 		 * way to determine the zone.
   1061 		 */
   1062 		eip6 = (struct ip6_hdr *)(icmp6 + 1);
   1063 
   1064 		bzero(&icmp6dst, sizeof(icmp6dst));
   1065 		icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
   1066 		icmp6dst.sin6_family = AF_INET6;
   1067 		if (finaldst == NULL)
   1068 			icmp6dst.sin6_addr = eip6->ip6_dst;
   1069 		else
   1070 			icmp6dst.sin6_addr = *finaldst;
   1071 		if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
   1072 			goto freeit;
   1073 		bzero(&icmp6src, sizeof(icmp6src));
   1074 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
   1075 		icmp6src.sin6_family = AF_INET6;
   1076 		icmp6src.sin6_addr = eip6->ip6_src;
   1077 		if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
   1078 			goto freeit;
   1079 		icmp6src.sin6_flowinfo =
   1080 			(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);
   1081 
   1082 		if (finaldst == NULL)
   1083 			finaldst = &eip6->ip6_dst;
   1084 		ip6cp.ip6c_m = m;
   1085 		ip6cp.ip6c_icmp6 = icmp6;
   1086 		ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
   1087 		ip6cp.ip6c_off = eoff;
   1088 		ip6cp.ip6c_finaldst = finaldst;
   1089 		ip6cp.ip6c_src = &icmp6src;
   1090 		ip6cp.ip6c_nxt = nxt;
   1091 
   1092 		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
   1093 			notifymtu = ntohl(icmp6->icmp6_mtu);
   1094 			ip6cp.ip6c_cmdarg = (void *)&notifymtu;
   1095 		}
   1096 
   1097 		ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
   1098 			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
   1099 		if (ctlfunc) {
   1100 			(void) (*ctlfunc)(code, (struct sockaddr *)&icmp6dst,
   1101 					  &ip6cp);
   1102 		}
   1103 	}
   1104 	return (0);
   1105 
   1106   freeit:
   1107 	m_freem(m);
   1108 	return (-1);
   1109 }
   1110 
   1111 void
   1112 icmp6_mtudisc_update(ip6cp, validated)
   1113 	struct ip6ctlparam *ip6cp;
   1114 	int validated;
   1115 {
   1116 	unsigned long rtcount;
   1117 	struct icmp6_mtudisc_callback *mc;
   1118 	struct in6_addr *dst = ip6cp->ip6c_finaldst;
   1119 	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
   1120 	struct mbuf *m = ip6cp->ip6c_m;	/* will be necessary for scope issue */
   1121 	u_int mtu = ntohl(icmp6->icmp6_mtu);
   1122 	struct rtentry *rt = NULL;
   1123 	struct sockaddr_in6 sin6;
   1124 
   1125 	/*
   1126 	 * allow non-validated cases if memory is plenty, to make traffic
   1127 	 * from non-connected pcb happy.
   1128 	 */
   1129 	rtcount = rt_timer_count(icmp6_mtudisc_timeout_q);
   1130 	if (validated) {
   1131 		if (0 <= icmp6_mtudisc_hiwat && rtcount > icmp6_mtudisc_hiwat)
   1132 			return;
   1133 		else if (0 <= icmp6_mtudisc_lowat &&
   1134 		    rtcount > icmp6_mtudisc_lowat) {
   1135 			/*
   1136 			 * XXX nuke a victim, install the new one.
   1137 			 */
   1138 		}
   1139 	} else {
   1140 		if (0 <= icmp6_mtudisc_lowat && rtcount > icmp6_mtudisc_lowat)
   1141 			return;
   1142 	}
   1143 
   1144 	bzero(&sin6, sizeof(sin6));
   1145 	sin6.sin6_family = PF_INET6;
   1146 	sin6.sin6_len = sizeof(struct sockaddr_in6);
   1147 	sin6.sin6_addr = *dst;
   1148 	if (in6_setscope(&sin6.sin6_addr, m->m_pkthdr.rcvif, NULL))
   1149 		return;
   1150 
   1151 	rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
   1152 
   1153 	if (rt && (rt->rt_flags & RTF_HOST) &&
   1154 	    !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
   1155 	    (rt->rt_rmx.rmx_mtu > mtu || rt->rt_rmx.rmx_mtu == 0)) {
   1156 		if (mtu < IN6_LINKMTU(rt->rt_ifp)) {
   1157 			icmp6stat.icp6s_pmtuchg++;
   1158 			rt->rt_rmx.rmx_mtu = mtu;
   1159 		}
   1160 	}
   1161 	if (rt) { /* XXX: need braces to avoid conflict with else in RTFREE. */
   1162 		RTFREE(rt);
   1163 	}
   1164 
   1165 	/*
   1166 	 * Notify protocols that the MTU for this destination
   1167 	 * has changed.
   1168 	 */
   1169 	for (mc = LIST_FIRST(&icmp6_mtudisc_callbacks); mc != NULL;
   1170 	     mc = LIST_NEXT(mc, mc_list))
   1171 		(*mc->mc_func)(&sin6.sin6_addr);
   1172 }
   1173 
   1174 /*
   1175  * Process a Node Information Query packet, based on
   1176  * draft-ietf-ipngwg-icmp-name-lookups-07.
   1177  *
   1178  * Spec incompatibilities:
   1179  * - IPv6 Subject address handling
   1180  * - IPv4 Subject address handling support missing
   1181  * - Proxy reply (answer even if it's not for me)
   1182  * - joins NI group address at in6_ifattach() time only, does not cope
   1183  *   with hostname changes by sethostname(3)
   1184  */
   1185 #ifndef offsetof		/* XXX */
   1186 #define	offsetof(type, member)	((size_t)(&((type *)0)->member))
   1187 #endif
   1188 static struct mbuf *
   1189 ni6_input(m, off)
   1190 	struct mbuf *m;
   1191 	int off;
   1192 {
   1193 	struct icmp6_nodeinfo *ni6, *nni6;
   1194 	struct mbuf *n = NULL;
   1195 	u_int16_t qtype;
   1196 	int subjlen;
   1197 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
   1198 	struct ni_reply_fqdn *fqdn;
   1199 	int addrs;		/* for NI_QTYPE_NODEADDR */
   1200 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
   1201 	struct sockaddr_in6 sin6; /* ip6_dst */
   1202 	struct in6_addr in6_subj; /* subject address */
   1203 	struct ip6_hdr *ip6;
   1204 	int oldfqdn = 0;	/* if 1, return pascal string (03 draft) */
   1205 	char *subj = NULL;
   1206 
   1207 	ip6 = mtod(m, struct ip6_hdr *);
   1208 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
   1209 	if (ni6 == NULL) {
   1210 		/* m is already reclaimed */
   1211 		return NULL;
   1212 	}
   1213 
   1214 	/*
   1215 	 * Validate IPv6 destination address.
   1216 	 *
   1217 	 * The Responder must discard the Query without further processing
   1218 	 * unless it is one of the Responder's unicast or anycast addresses, or
   1219 	 * a link-local scope multicast address which the Responder has joined.
   1220 	 * [icmp-name-lookups-07, Section 4.]
   1221 	 */
   1222 	bzero(&sin6, sizeof(sin6));
   1223 	sin6.sin6_family = AF_INET6;
   1224 	sin6.sin6_len = sizeof(struct sockaddr_in6);
   1225 	bcopy(&ip6->ip6_dst, &sin6.sin6_addr, sizeof(sin6.sin6_addr));
   1226 	/* XXX scopeid */
   1227 	if (ifa_ifwithaddr((struct sockaddr *)&sin6))
   1228 		; /* unicast/anycast, fine */
   1229 	else if (IN6_IS_ADDR_MC_LINKLOCAL(&sin6.sin6_addr))
   1230 		; /* link-local multicast, fine */
   1231 	else
   1232 		goto bad;
   1233 
   1234 	/* validate query Subject field. */
   1235 	qtype = ntohs(ni6->ni_qtype);
   1236 	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
   1237 	switch (qtype) {
   1238 	case NI_QTYPE_NOOP:
   1239 	case NI_QTYPE_SUPTYPES:
   1240 		/* 07 draft */
   1241 		if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
   1242 			break;
   1243 		/* FALLTHROUGH */
   1244 	case NI_QTYPE_FQDN:
   1245 	case NI_QTYPE_NODEADDR:
   1246 	case NI_QTYPE_IPV4ADDR:
   1247 		switch (ni6->ni_code) {
   1248 		case ICMP6_NI_SUBJ_IPV6:
   1249 #if ICMP6_NI_SUBJ_IPV6 != 0
   1250 		case 0:
   1251 #endif
   1252 			/*
   1253 			 * backward compatibility - try to accept 03 draft
   1254 			 * format, where no Subject is present.
   1255 			 */
   1256 			if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
   1257 			    subjlen == 0) {
   1258 				oldfqdn++;
   1259 				break;
   1260 			}
   1261 #if ICMP6_NI_SUBJ_IPV6 != 0
   1262 			if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
   1263 				goto bad;
   1264 #endif
   1265 
   1266 			if (subjlen != sizeof(sin6.sin6_addr))
   1267 				goto bad;
   1268 
   1269 			/*
   1270 			 * Validate Subject address.
   1271 			 *
   1272 			 * Not sure what exactly "address belongs to the node"
   1273 			 * means in the spec, is it just unicast, or what?
   1274 			 *
   1275 			 * At this moment we consider Subject address as
   1276 			 * "belong to the node" if the Subject address equals
   1277 			 * to the IPv6 destination address; validation for
   1278 			 * IPv6 destination address should have done enough
   1279 			 * check for us.
   1280 			 *
   1281 			 * We do not do proxy at this moment.
   1282 			 */
   1283 			/* m_pulldown instead of copy? */
   1284 			m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
   1285 			    subjlen, (caddr_t)&in6_subj);
   1286 			if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
   1287 				goto bad;
   1288 
   1289 			subj = (char *)&in6_subj;
   1290 			if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
   1291 				break;
   1292 
   1293 			/*
   1294 			 * XXX if we are to allow other cases, we should really
   1295 			 * be careful about scope here.
   1296 			 * basically, we should disallow queries toward IPv6
   1297 			 * destination X with subject Y, if scope(X) > scope(Y).
   1298 			 * if we allow scope(X) > scope(Y), it will result in
   1299 			 * information leakage across scope boundary.
   1300 			 */
   1301 			goto bad;
   1302 
   1303 		case ICMP6_NI_SUBJ_FQDN:
   1304 			/*
   1305 			 * Validate Subject name with gethostname(3).
   1306 			 *
   1307 			 * The behavior may need some debate, since:
   1308 			 * - we are not sure if the node has FQDN as
   1309 			 *   hostname (returned by gethostname(3)).
   1310 			 * - the code does wildcard match for truncated names.
   1311 			 *   however, we are not sure if we want to perform
   1312 			 *   wildcard match, if gethostname(3) side has
   1313 			 *   truncated hostname.
   1314 			 */
   1315 			n = ni6_nametodns(hostname, hostnamelen, 0);
   1316 			if (!n || n->m_next || n->m_len == 0)
   1317 				goto bad;
   1318 			IP6_EXTHDR_GET(subj, char *, m,
   1319 			    off + sizeof(struct icmp6_nodeinfo), subjlen);
   1320 			if (subj == NULL)
   1321 				goto bad;
   1322 			if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
   1323 					n->m_len)) {
   1324 				goto bad;
   1325 			}
   1326 			m_freem(n);
   1327 			n = NULL;
   1328 			break;
   1329 
   1330 		case ICMP6_NI_SUBJ_IPV4:	/* XXX: to be implemented? */
   1331 		default:
   1332 			goto bad;
   1333 		}
   1334 		break;
   1335 	}
   1336 
   1337 	/* refuse based on configuration.  XXX ICMP6_NI_REFUSED? */
   1338 	switch (qtype) {
   1339 	case NI_QTYPE_FQDN:
   1340 		if ((icmp6_nodeinfo & 1) == 0)
   1341 			goto bad;
   1342 		break;
   1343 	case NI_QTYPE_NODEADDR:
   1344 	case NI_QTYPE_IPV4ADDR:
   1345 		if ((icmp6_nodeinfo & 2) == 0)
   1346 			goto bad;
   1347 		break;
   1348 	}
   1349 
   1350 	/* guess reply length */
   1351 	switch (qtype) {
   1352 	case NI_QTYPE_NOOP:
   1353 		break;		/* no reply data */
   1354 	case NI_QTYPE_SUPTYPES:
   1355 		replylen += sizeof(u_int32_t);
   1356 		break;
   1357 	case NI_QTYPE_FQDN:
   1358 		/* XXX will append an mbuf */
   1359 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
   1360 		break;
   1361 	case NI_QTYPE_NODEADDR:
   1362 		addrs = ni6_addrs(ni6, m, &ifp, subj);
   1363 		if ((replylen += addrs * (sizeof(struct in6_addr) +
   1364 					  sizeof(u_int32_t))) > MCLBYTES)
   1365 			replylen = MCLBYTES; /* XXX: will truncate pkt later */
   1366 		break;
   1367 	case NI_QTYPE_IPV4ADDR:
   1368 		/* unsupported - should respond with unknown Qtype? */
   1369 		goto bad;
   1370 	default:
   1371 		/*
   1372 		 * XXX: We must return a reply with the ICMP6 code
   1373 		 * `unknown Qtype' in this case.  However we regard the case
   1374 		 * as an FQDN query for backward compatibility.
   1375 		 * Older versions set a random value to this field,
   1376 		 * so it rarely varies in the defined qtypes.
   1377 		 * But the mechanism is not reliable...
   1378 		 * maybe we should obsolete older versions.
   1379 		 */
   1380 		qtype = NI_QTYPE_FQDN;
   1381 		/* XXX will append an mbuf */
   1382 		replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
   1383 		oldfqdn++;
   1384 		break;
   1385 	}
   1386 
   1387 	/* allocate an mbuf to reply. */
   1388 	MGETHDR(n, M_DONTWAIT, m->m_type);
   1389 	if (n == NULL) {
   1390 		m_freem(m);
   1391 		return (NULL);
   1392 	}
   1393 	M_MOVE_PKTHDR(n, m); /* just for rcvif */
   1394 	if (replylen > MHLEN) {
   1395 		if (replylen > MCLBYTES) {
   1396 			/*
   1397 			 * XXX: should we try to allocate more? But MCLBYTES
   1398 			 * is probably much larger than IPV6_MMTU...
   1399 			 */
   1400 			goto bad;
   1401 		}
   1402 		MCLGET(n, M_DONTWAIT);
   1403 		if ((n->m_flags & M_EXT) == 0) {
   1404 			goto bad;
   1405 		}
   1406 	}
   1407 	n->m_pkthdr.len = n->m_len = replylen;
   1408 
   1409 	/* copy mbuf header and IPv6 + Node Information base headers */
   1410 	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
   1411 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
   1412 	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
   1413 
   1414 	/* qtype dependent procedure */
   1415 	switch (qtype) {
   1416 	case NI_QTYPE_NOOP:
   1417 		nni6->ni_code = ICMP6_NI_SUCCESS;
   1418 		nni6->ni_flags = 0;
   1419 		break;
   1420 	case NI_QTYPE_SUPTYPES:
   1421 	{
   1422 		u_int32_t v;
   1423 		nni6->ni_code = ICMP6_NI_SUCCESS;
   1424 		nni6->ni_flags = htons(0x0000);	/* raw bitmap */
   1425 		/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
   1426 		v = (u_int32_t)htonl(0x0000000f);
   1427 		bcopy(&v, nni6 + 1, sizeof(u_int32_t));
   1428 		break;
   1429 	}
   1430 	case NI_QTYPE_FQDN:
   1431 		nni6->ni_code = ICMP6_NI_SUCCESS;
   1432 		fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
   1433 						sizeof(struct ip6_hdr) +
   1434 						sizeof(struct icmp6_nodeinfo));
   1435 		nni6->ni_flags = 0; /* XXX: meaningless TTL */
   1436 		fqdn->ni_fqdn_ttl = 0;	/* ditto. */
   1437 		/*
   1438 		 * XXX do we really have FQDN in variable "hostname"?
   1439 		 */
   1440 		n->m_next = ni6_nametodns(hostname, hostnamelen, oldfqdn);
   1441 		if (n->m_next == NULL)
   1442 			goto bad;
   1443 		/* XXX we assume that n->m_next is not a chain */
   1444 		if (n->m_next->m_next != NULL)
   1445 			goto bad;
   1446 		n->m_pkthdr.len += n->m_next->m_len;
   1447 		break;
   1448 	case NI_QTYPE_NODEADDR:
   1449 	{
   1450 		int lenlim, copied;
   1451 
   1452 		nni6->ni_code = ICMP6_NI_SUCCESS;
   1453 		n->m_pkthdr.len = n->m_len =
   1454 		    sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
   1455 		lenlim = M_TRAILINGSPACE(n);
   1456 		copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
   1457 		/* XXX: reset mbuf length */
   1458 		n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
   1459 			sizeof(struct icmp6_nodeinfo) + copied;
   1460 		break;
   1461 	}
   1462 	default:
   1463 		break;		/* XXX impossible! */
   1464 	}
   1465 
   1466 	nni6->ni_type = ICMP6_NI_REPLY;
   1467 	m_freem(m);
   1468 	return (n);
   1469 
   1470   bad:
   1471 	m_freem(m);
   1472 	if (n)
   1473 		m_freem(n);
   1474 	return (NULL);
   1475 }
   1476 #undef hostnamelen
   1477 
   1478 #define isupper(x) ('A' <= (x) && (x) <= 'Z')
   1479 #define isalpha(x) (('A' <= (x) && (x) <= 'Z') || ('a' <= (x) && (x) <= 'z'))
   1480 #define isalnum(x) (isalpha(x) || ('0' <= (x) && (x) <= '9'))
   1481 #define tolower(x) (isupper(x) ? (x) + 'a' - 'A' : (x))
   1482 
   1483 /*
   1484  * make a mbuf with DNS-encoded string.  no compression support.
   1485  *
   1486  * XXX names with less than 2 dots (like "foo" or "foo.section") will be
   1487  * treated as truncated name (two \0 at the end).  this is a wild guess.
   1488  */
   1489 static struct mbuf *
   1490 ni6_nametodns(name, namelen, old)
   1491 	const char *name;
   1492 	int namelen;
   1493 	int old;	/* return pascal string if non-zero */
   1494 {
   1495 	struct mbuf *m;
   1496 	char *cp, *ep;
   1497 	const char *p, *q;
   1498 	int i, len, nterm;
   1499 
   1500 	if (old)
   1501 		len = namelen + 1;
   1502 	else
   1503 		len = MCLBYTES;
   1504 
   1505 	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
   1506 	MGET(m, M_DONTWAIT, MT_DATA);
   1507 	if (m && len > MLEN) {
   1508 		MCLGET(m, M_DONTWAIT);
   1509 		if ((m->m_flags & M_EXT) == 0)
   1510 			goto fail;
   1511 	}
   1512 	if (!m)
   1513 		goto fail;
   1514 	m->m_next = NULL;
   1515 
   1516 	if (old) {
   1517 		m->m_len = len;
   1518 		*mtod(m, char *) = namelen;
   1519 		bcopy(name, mtod(m, char *) + 1, namelen);
   1520 		return m;
   1521 	} else {
   1522 		m->m_len = 0;
   1523 		cp = mtod(m, char *);
   1524 		ep = mtod(m, char *) + M_TRAILINGSPACE(m);
   1525 
   1526 		/* if not certain about my name, return empty buffer */
   1527 		if (namelen == 0)
   1528 			return m;
   1529 
   1530 		/*
   1531 		 * guess if it looks like shortened hostname, or FQDN.
   1532 		 * shortened hostname needs two trailing "\0".
   1533 		 */
   1534 		i = 0;
   1535 		for (p = name; p < name + namelen; p++) {
   1536 			if (*p && *p == '.')
   1537 				i++;
   1538 		}
   1539 		if (i < 2)
   1540 			nterm = 2;
   1541 		else
   1542 			nterm = 1;
   1543 
   1544 		p = name;
   1545 		while (cp < ep && p < name + namelen) {
   1546 			i = 0;
   1547 			for (q = p; q < name + namelen && *q && *q != '.'; q++)
   1548 				i++;
   1549 			/* result does not fit into mbuf */
   1550 			if (cp + i + 1 >= ep)
   1551 				goto fail;
   1552 			/*
   1553 			 * DNS label length restriction, RFC1035 page 8.
   1554 			 * "i == 0" case is included here to avoid returning
   1555 			 * 0-length label on "foo..bar".
   1556 			 */
   1557 			if (i <= 0 || i >= 64)
   1558 				goto fail;
   1559 			*cp++ = i;
   1560 			if (!isalpha(p[0]) || !isalnum(p[i - 1]))
   1561 				goto fail;
   1562 			while (i > 0) {
   1563 				if (!isalnum(*p) && *p != '-')
   1564 					goto fail;
   1565 				if (isupper(*p)) {
   1566 					*cp++ = tolower(*p);
   1567 					p++;
   1568 				} else
   1569 					*cp++ = *p++;
   1570 				i--;
   1571 			}
   1572 			p = q;
   1573 			if (p < name + namelen && *p == '.')
   1574 				p++;
   1575 		}
   1576 		/* termination */
   1577 		if (cp + nterm >= ep)
   1578 			goto fail;
   1579 		while (nterm-- > 0)
   1580 			*cp++ = '\0';
   1581 		m->m_len = cp - mtod(m, char *);
   1582 		return m;
   1583 	}
   1584 
   1585 	panic("should not reach here");
   1586 	/* NOTREACHED */
   1587 
   1588  fail:
   1589 	if (m)
   1590 		m_freem(m);
   1591 	return NULL;
   1592 }
   1593 
   1594 /*
   1595  * check if two DNS-encoded string matches.  takes care of truncated
   1596  * form (with \0\0 at the end).  no compression support.
   1597  * XXX upper/lowercase match (see RFC2065)
   1598  */
   1599 static int
   1600 ni6_dnsmatch(a, alen, b, blen)
   1601 	const char *a;
   1602 	int alen;
   1603 	const char *b;
   1604 	int blen;
   1605 {
   1606 	const char *a0, *b0;
   1607 	int l;
   1608 
   1609 	/* simplest case - need validation? */
   1610 	if (alen == blen && bcmp(a, b, alen) == 0)
   1611 		return 1;
   1612 
   1613 	a0 = a;
   1614 	b0 = b;
   1615 
   1616 	/* termination is mandatory */
   1617 	if (alen < 2 || blen < 2)
   1618 		return 0;
   1619 	if (a0[alen - 1] != '\0' || b0[blen - 1] != '\0')
   1620 		return 0;
   1621 	alen--;
   1622 	blen--;
   1623 
   1624 	while (a - a0 < alen && b - b0 < blen) {
   1625 		if (a - a0 + 1 > alen || b - b0 + 1 > blen)
   1626 			return 0;
   1627 
   1628 		if ((signed char)a[0] < 0 || (signed char)b[0] < 0)
   1629 			return 0;
   1630 		/* we don't support compression yet */
   1631 		if (a[0] >= 64 || b[0] >= 64)
   1632 			return 0;
   1633 
   1634 		/* truncated case */
   1635 		if (a[0] == 0 && a - a0 == alen - 1)
   1636 			return 1;
   1637 		if (b[0] == 0 && b - b0 == blen - 1)
   1638 			return 1;
   1639 		if (a[0] == 0 || b[0] == 0)
   1640 			return 0;
   1641 
   1642 		if (a[0] != b[0])
   1643 			return 0;
   1644 		l = a[0];
   1645 		if (a - a0 + 1 + l > alen || b - b0 + 1 + l > blen)
   1646 			return 0;
   1647 		if (bcmp(a + 1, b + 1, l) != 0)
   1648 			return 0;
   1649 
   1650 		a += 1 + l;
   1651 		b += 1 + l;
   1652 	}
   1653 
   1654 	if (a - a0 == alen && b - b0 == blen)
   1655 		return 1;
   1656 	else
   1657 		return 0;
   1658 }
   1659 
   1660 /*
   1661  * calculate the number of addresses to be returned in the node info reply.
   1662  */
   1663 static int
   1664 ni6_addrs(ni6, m, ifpp, subj)
   1665 	struct icmp6_nodeinfo *ni6;
   1666 	struct mbuf *m;
   1667 	struct ifnet **ifpp;
   1668 	char *subj;
   1669 {
   1670 	struct ifnet *ifp;
   1671 	struct in6_ifaddr *ifa6;
   1672 	struct ifaddr *ifa;
   1673 	struct sockaddr_in6 *subj_ip6 = NULL; /* XXX pedant */
   1674 	int addrs = 0, addrsofif, iffound = 0;
   1675 	int niflags = ni6->ni_flags;
   1676 
   1677 	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
   1678 		switch (ni6->ni_code) {
   1679 		case ICMP6_NI_SUBJ_IPV6:
   1680 			if (subj == NULL) /* must be impossible... */
   1681 				return (0);
   1682 			subj_ip6 = (struct sockaddr_in6 *)subj;
   1683 			break;
   1684 		default:
   1685 			/*
   1686 			 * XXX: we only support IPv6 subject address for
   1687 			 * this Qtype.
   1688 			 */
   1689 			return (0);
   1690 		}
   1691 	}
   1692 
   1693 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
   1694 	{
   1695 		addrsofif = 0;
   1696 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
   1697 		     ifa = ifa->ifa_list.tqe_next)
   1698 		{
   1699 			if (ifa->ifa_addr->sa_family != AF_INET6)
   1700 				continue;
   1701 			ifa6 = (struct in6_ifaddr *)ifa;
   1702 
   1703 			if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
   1704 			    IN6_ARE_ADDR_EQUAL(&subj_ip6->sin6_addr,
   1705 					       &ifa6->ia_addr.sin6_addr))
   1706 				iffound = 1;
   1707 
   1708 			/*
   1709 			 * IPv4-mapped addresses can only be returned by a
   1710 			 * Node Information proxy, since they represent
   1711 			 * addresses of IPv4-only nodes, which perforce do
   1712 			 * not implement this protocol.
   1713 			 * [icmp-name-lookups-07, Section 5.4]
   1714 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
   1715 			 * this function at this moment.
   1716 			 */
   1717 
   1718 			/* What do we have to do about ::1? */
   1719 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
   1720 			case IPV6_ADDR_SCOPE_LINKLOCAL:
   1721 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
   1722 					continue;
   1723 				break;
   1724 			case IPV6_ADDR_SCOPE_SITELOCAL:
   1725 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
   1726 					continue;
   1727 				break;
   1728 			case IPV6_ADDR_SCOPE_GLOBAL:
   1729 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
   1730 					continue;
   1731 				break;
   1732 			default:
   1733 				continue;
   1734 			}
   1735 
   1736 			/*
   1737 			 * check if anycast is okay.
   1738 			 * XXX: just experimental.  not in the spec.
   1739 			 */
   1740 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
   1741 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
   1742 				continue; /* we need only unicast addresses */
   1743 
   1744 			addrsofif++; /* count the address */
   1745 		}
   1746 		if (iffound) {
   1747 			*ifpp = ifp;
   1748 			return (addrsofif);
   1749 		}
   1750 
   1751 		addrs += addrsofif;
   1752 	}
   1753 
   1754 	return (addrs);
   1755 }
   1756 
   1757 static int
   1758 ni6_store_addrs(ni6, nni6, ifp0, resid)
   1759 	struct icmp6_nodeinfo *ni6, *nni6;
   1760 	struct ifnet *ifp0;
   1761 	int resid;
   1762 {
   1763 	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
   1764 	struct in6_ifaddr *ifa6;
   1765 	struct ifaddr *ifa;
   1766 	struct ifnet *ifp_dep = NULL;
   1767 	int copied = 0, allow_deprecated = 0;
   1768 	u_char *cp = (u_char *)(nni6 + 1);
   1769 	int niflags = ni6->ni_flags;
   1770 	u_int32_t ltime;
   1771 
   1772 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
   1773 		return (0);	/* needless to copy */
   1774 
   1775   again:
   1776 
   1777 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
   1778 	{
   1779 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
   1780 		     ifa = ifa->ifa_list.tqe_next)
   1781 		{
   1782 			if (ifa->ifa_addr->sa_family != AF_INET6)
   1783 				continue;
   1784 			ifa6 = (struct in6_ifaddr *)ifa;
   1785 
   1786 			if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
   1787 			    allow_deprecated == 0) {
   1788 				/*
   1789 				 * prefererred address should be put before
   1790 				 * deprecated addresses.
   1791 				 */
   1792 
   1793 				/* record the interface for later search */
   1794 				if (ifp_dep == NULL)
   1795 					ifp_dep = ifp;
   1796 
   1797 				continue;
   1798 			}
   1799 			else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
   1800 				 allow_deprecated != 0)
   1801 				continue; /* we now collect deprecated addrs */
   1802 
   1803 			/* What do we have to do about ::1? */
   1804 			switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
   1805 			case IPV6_ADDR_SCOPE_LINKLOCAL:
   1806 				if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
   1807 					continue;
   1808 				break;
   1809 			case IPV6_ADDR_SCOPE_SITELOCAL:
   1810 				if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
   1811 					continue;
   1812 				break;
   1813 			case IPV6_ADDR_SCOPE_GLOBAL:
   1814 				if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
   1815 					continue;
   1816 				break;
   1817 			default:
   1818 				continue;
   1819 			}
   1820 
   1821 			/*
   1822 			 * check if anycast is okay.
   1823 			 * XXX: just experimental.  not in the spec.
   1824 			 */
   1825 			if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
   1826 			    (niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
   1827 				continue;
   1828 
   1829 			/* now we can copy the address */
   1830 			if (resid < sizeof(struct in6_addr) +
   1831 			    sizeof(u_int32_t)) {
   1832 				/*
   1833 				 * We give up much more copy.
   1834 				 * Set the truncate flag and return.
   1835 				 */
   1836 				nni6->ni_flags |= NI_NODEADDR_FLAG_TRUNCATE;
   1837 				return (copied);
   1838 			}
   1839 
   1840 			/*
   1841 			 * Set the TTL of the address.
   1842 			 * The TTL value should be one of the following
   1843 			 * according to the specification:
   1844 			 *
   1845 			 * 1. The remaining lifetime of a DHCP lease on the
   1846 			 *    address, or
   1847 			 * 2. The remaining Valid Lifetime of a prefix from
   1848 			 *    which the address was derived through Stateless
   1849 			 *    Autoconfiguration.
   1850 			 *
   1851 			 * Note that we currently do not support stateful
   1852 			 * address configuration by DHCPv6, so the former
   1853 			 * case can't happen.
   1854 			 *
   1855 			 * TTL must be 2^31 > TTL >= 0.
   1856 			 */
   1857 			if (ifa6->ia6_lifetime.ia6t_expire == 0)
   1858 				ltime = ND6_INFINITE_LIFETIME;
   1859 			else {
   1860 				if (ifa6->ia6_lifetime.ia6t_expire >
   1861 				    time.tv_sec)
   1862 					ltime = ifa6->ia6_lifetime.ia6t_expire - time.tv_sec;
   1863 				else
   1864 					ltime = 0;
   1865 			}
   1866 			if (ltime > 0x7fffffff)
   1867 				ltime = 0x7fffffff;
   1868 			ltime = htonl(ltime);
   1869 
   1870 			bcopy(&ltime, cp, sizeof(u_int32_t));
   1871 			cp += sizeof(u_int32_t);
   1872 
   1873 			/* copy the address itself */
   1874 			bcopy(&ifa6->ia_addr.sin6_addr, cp,
   1875 			      sizeof(struct in6_addr));
   1876 			in6_clearscope((struct in6_addr *)cp); /* XXX */
   1877 			cp += sizeof(struct in6_addr);
   1878 
   1879 			resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
   1880 			copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
   1881 		}
   1882 		if (ifp0)	/* we need search only on the specified IF */
   1883 			break;
   1884 	}
   1885 
   1886 	if (allow_deprecated == 0 && ifp_dep != NULL) {
   1887 		ifp = ifp_dep;
   1888 		allow_deprecated = 1;
   1889 
   1890 		goto again;
   1891 	}
   1892 
   1893 	return (copied);
   1894 }
   1895 
   1896 /*
   1897  * XXX almost dup'ed code with rip6_input.
   1898  */
   1899 static int
   1900 icmp6_rip6_input(mp, off)
   1901 	struct	mbuf **mp;
   1902 	int	off;
   1903 {
   1904 	struct mbuf *m = *mp;
   1905 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   1906 	struct inpcb_hdr *inph;
   1907 	struct in6pcb *in6p;
   1908 	struct in6pcb *last = NULL;
   1909 	struct sockaddr_in6 rip6src;
   1910 	struct icmp6_hdr *icmp6;
   1911 	struct mbuf *opts = NULL;
   1912 
   1913 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
   1914 	if (icmp6 == NULL) {
   1915 		/* m is already reclaimed */
   1916 		return IPPROTO_DONE;
   1917 	}
   1918 
   1919 	/*
   1920 	 * XXX: the address may have embedded scope zone ID, which should be
   1921 	 * hidden from applications.
   1922 	 */
   1923 	bzero(&rip6src, sizeof(rip6src));
   1924 	rip6src.sin6_len = sizeof(struct sockaddr_in6);
   1925 	rip6src.sin6_family = AF_INET6;
   1926 	rip6src.sin6_addr = ip6->ip6_src;
   1927 	if (sa6_recoverscope(&rip6src)) {
   1928 		m_freem(m);
   1929 		return (IPPROTO_DONE);
   1930 	}
   1931 
   1932 	CIRCLEQ_FOREACH(inph, &raw6cbtable.inpt_queue, inph_queue) {
   1933 		in6p = (struct in6pcb *)inph;
   1934 		if (in6p->in6p_af != AF_INET6)
   1935 			continue;
   1936 		if (in6p->in6p_ip6.ip6_nxt != IPPROTO_ICMPV6)
   1937 			continue;
   1938 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
   1939 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
   1940 			continue;
   1941 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
   1942 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
   1943 			continue;
   1944 		if (in6p->in6p_icmp6filt
   1945 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
   1946 				 in6p->in6p_icmp6filt))
   1947 			continue;
   1948 		if (last) {
   1949 			struct	mbuf *n;
   1950 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
   1951 				if (last->in6p_flags & IN6P_CONTROLOPTS)
   1952 					ip6_savecontrol(last, &opts, ip6, n);
   1953 				/* strip intermediate headers */
   1954 				m_adj(n, off);
   1955 				if (sbappendaddr(&last->in6p_socket->so_rcv,
   1956 						 (struct sockaddr *)&rip6src,
   1957 						 n, opts) == 0) {
   1958 					/* should notify about lost packet */
   1959 					m_freem(n);
   1960 					if (opts)
   1961 						m_freem(opts);
   1962 				} else
   1963 					sorwakeup(last->in6p_socket);
   1964 				opts = NULL;
   1965 			}
   1966 		}
   1967 		last = in6p;
   1968 	}
   1969 	if (last) {
   1970 		if (last->in6p_flags & IN6P_CONTROLOPTS)
   1971 			ip6_savecontrol(last, &opts, ip6, m);
   1972 		/* strip intermediate headers */
   1973 		m_adj(m, off);
   1974 		if (sbappendaddr(&last->in6p_socket->so_rcv,
   1975 				(struct sockaddr *)&rip6src, m, opts) == 0) {
   1976 			m_freem(m);
   1977 			if (opts)
   1978 				m_freem(opts);
   1979 		} else
   1980 			sorwakeup(last->in6p_socket);
   1981 	} else {
   1982 		m_freem(m);
   1983 		ip6stat.ip6s_delivered--;
   1984 	}
   1985 	return IPPROTO_DONE;
   1986 }
   1987 
   1988 /*
   1989  * Reflect the ip6 packet back to the source.
   1990  * OFF points to the icmp6 header, counted from the top of the mbuf.
   1991  *
   1992  * Note: RFC 1885 required that an echo reply should be truncated if it
   1993  * did not fit in with (return) path MTU, and KAME code supported the
   1994  * behavior.  However, as a clarification after the RFC, this limitation
   1995  * was removed in a revised version of the spec, RFC 2463.  We had kept the
   1996  * old behavior, with a (non-default) ifdef block, while the new version of
   1997  * the spec was an internet-draft status, and even after the new RFC was
   1998  * published.  But it would rather make sense to clean the obsoleted part
   1999  * up, and to make the code simpler at this stage.
   2000  */
   2001 void
   2002 icmp6_reflect(m, off)
   2003 	struct	mbuf *m;
   2004 	size_t off;
   2005 {
   2006 	struct ip6_hdr *ip6;
   2007 	struct icmp6_hdr *icmp6;
   2008 	struct in6_ifaddr *ia;
   2009 	int plen;
   2010 	int type, code;
   2011 	struct ifnet *outif = NULL;
   2012 	struct in6_addr origdst, *src = NULL;
   2013 
   2014 	/* too short to reflect */
   2015 	if (off < sizeof(struct ip6_hdr)) {
   2016 		nd6log((LOG_DEBUG,
   2017 		    "sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
   2018 		    (u_long)off, (u_long)sizeof(struct ip6_hdr),
   2019 		    __FILE__, __LINE__));
   2020 		goto bad;
   2021 	}
   2022 
   2023 	/*
   2024 	 * If there are extra headers between IPv6 and ICMPv6, strip
   2025 	 * off that header first.
   2026 	 */
   2027 #ifdef DIAGNOSTIC
   2028 	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
   2029 		panic("assumption failed in icmp6_reflect");
   2030 #endif
   2031 	if (off > sizeof(struct ip6_hdr)) {
   2032 		size_t l;
   2033 		struct ip6_hdr nip6;
   2034 
   2035 		l = off - sizeof(struct ip6_hdr);
   2036 		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
   2037 		m_adj(m, l);
   2038 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
   2039 		if (m->m_len < l) {
   2040 			if ((m = m_pullup(m, l)) == NULL)
   2041 				return;
   2042 		}
   2043 		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
   2044 	} else /* off == sizeof(struct ip6_hdr) */ {
   2045 		size_t l;
   2046 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
   2047 		if (m->m_len < l) {
   2048 			if ((m = m_pullup(m, l)) == NULL)
   2049 				return;
   2050 		}
   2051 	}
   2052 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
   2053 	ip6 = mtod(m, struct ip6_hdr *);
   2054 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   2055 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
   2056 	type = icmp6->icmp6_type; /* keep type for statistics */
   2057 	code = icmp6->icmp6_code; /* ditto. */
   2058 
   2059 	origdst = ip6->ip6_dst;
   2060 	/*
   2061 	 * ip6_input() drops a packet if its src is multicast.
   2062 	 * So, the src is never multicast.
   2063 	 */
   2064 	ip6->ip6_dst = ip6->ip6_src;
   2065 
   2066 	/*
   2067 	 * If the incoming packet was addressed directly to us (i.e. unicast),
   2068 	 * use dst as the src for the reply.
   2069 	 * The IN6_IFF_NOTREADY case should be VERY rare, but is possible
   2070 	 * (for example) when we encounter an error while forwarding procedure
   2071 	 * destined to a duplicated address of ours.
   2072 	 * Note that ip6_getdstifaddr() may fail if we are in an error handling
   2073 	 * procedure of an outgoing packet of our own, in which case we need
   2074 	 * to search in the ifaddr list.
   2075 	 */
   2076 	if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
   2077 		if ((ia = ip6_getdstifaddr(m))) {
   2078 			if (!(ia->ia6_flags &
   2079 			    (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)))
   2080 				src = &ia->ia_addr.sin6_addr;
   2081 		} else {
   2082 			struct sockaddr_in6 d;
   2083 
   2084 			bzero(&d, sizeof(d));
   2085 			d.sin6_family = AF_INET6;
   2086 			d.sin6_len = sizeof(d);
   2087 			d.sin6_addr = origdst;
   2088 			ia = (struct in6_ifaddr *)
   2089 			    ifa_ifwithaddr((struct sockaddr *)&d);
   2090 			if (ia &&
   2091 			    !(ia->ia6_flags &
   2092 			    (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY))) {
   2093 				src = &ia->ia_addr.sin6_addr;
   2094 			}
   2095 		}
   2096 	}
   2097 
   2098 	if (src == NULL) {
   2099 		int e;
   2100 		struct sockaddr_in6 sin6;
   2101 		struct route_in6 ro;
   2102 
   2103 		/*
   2104 		 * This case matches to multicasts, our anycast, or unicasts
   2105 		 * that we do not own.  Select a source address based on the
   2106 		 * source address of the erroneous packet.
   2107 		 */
   2108 		bzero(&sin6, sizeof(sin6));
   2109 		sin6.sin6_family = AF_INET6;
   2110 		sin6.sin6_len = sizeof(sin6);
   2111 		sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */
   2112 
   2113 		bzero(&ro, sizeof(ro));
   2114 		src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e);
   2115 		if (ro.ro_rt) { /* XXX: see comments in icmp6_mtudisc_update */
   2116 			RTFREE(ro.ro_rt); /* XXX: we could use this */
   2117 		}
   2118 		if (src == NULL) {
   2119 			nd6log((LOG_DEBUG,
   2120 			    "icmp6_reflect: source can't be determined: "
   2121 			    "dst=%s, error=%d\n",
   2122 			    ip6_sprintf(&sin6.sin6_addr), e));
   2123 			goto bad;
   2124 		}
   2125 	}
   2126 
   2127 	ip6->ip6_src = *src;
   2128 	ip6->ip6_flow = 0;
   2129 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
   2130 	ip6->ip6_vfc |= IPV6_VERSION;
   2131 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   2132 	if (m->m_pkthdr.rcvif) {
   2133 		/* XXX: This may not be the outgoing interface */
   2134 		ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
   2135 	} else
   2136 		ip6->ip6_hlim = ip6_defhlim;
   2137 
   2138 	icmp6->icmp6_cksum = 0;
   2139 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
   2140 					sizeof(struct ip6_hdr), plen);
   2141 
   2142 	/*
   2143 	 * XXX option handling
   2144 	 */
   2145 
   2146 	m->m_flags &= ~(M_BCAST|M_MCAST);
   2147 
   2148 	/*
   2149 	 * To avoid a "too big" situation at an intermediate router
   2150 	 * and the path MTU discovery process, specify the IPV6_MINMTU flag.
   2151 	 * Note that only echo and node information replies are affected,
   2152 	 * since the length of ICMP6 errors is limited to the minimum MTU.
   2153 	 */
   2154 	if (ip6_output(m, NULL, NULL, IPV6_MINMTU, NULL, NULL, &outif) != 0 &&
   2155 	    outif)
   2156 		icmp6_ifstat_inc(outif, ifs6_out_error);
   2157 
   2158 	if (outif)
   2159 		icmp6_ifoutstat_inc(outif, type, code);
   2160 
   2161 	return;
   2162 
   2163  bad:
   2164 	m_freem(m);
   2165 	return;
   2166 }
   2167 
   2168 static const char *
   2169 icmp6_redirect_diag(src6, dst6, tgt6)
   2170 	struct in6_addr *src6;
   2171 	struct in6_addr *dst6;
   2172 	struct in6_addr *tgt6;
   2173 {
   2174 	static char buf[1024];
   2175 	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
   2176 		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
   2177 	return buf;
   2178 }
   2179 
   2180 void
   2181 icmp6_redirect_input(m, off)
   2182 	struct mbuf *m;
   2183 	int off;
   2184 {
   2185 	struct ifnet *ifp = m->m_pkthdr.rcvif;
   2186 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   2187 	struct nd_redirect *nd_rd;
   2188 	int icmp6len = ntohs(ip6->ip6_plen);
   2189 	char *lladdr = NULL;
   2190 	int lladdrlen = 0;
   2191 	struct rtentry *rt = NULL;
   2192 	int is_router;
   2193 	int is_onlink;
   2194 	struct in6_addr src6 = ip6->ip6_src;
   2195 	struct in6_addr redtgt6;
   2196 	struct in6_addr reddst6;
   2197 	union nd_opts ndopts;
   2198 
   2199 	if (!ifp)
   2200 		return;
   2201 
   2202 	/* XXX if we are router, we don't update route by icmp6 redirect */
   2203 	if (ip6_forwarding)
   2204 		goto freeit;
   2205 	if (!icmp6_rediraccept)
   2206 		goto freeit;
   2207 
   2208 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
   2209 	if (nd_rd == NULL) {
   2210 		icmp6stat.icp6s_tooshort++;
   2211 		return;
   2212 	}
   2213 	redtgt6 = nd_rd->nd_rd_target;
   2214 	reddst6 = nd_rd->nd_rd_dst;
   2215 
   2216 	if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) ||
   2217 	    in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
   2218 		goto freeit;
   2219 	}
   2220 
   2221 	/* validation */
   2222 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
   2223 		nd6log((LOG_ERR,
   2224 			"ICMP6 redirect sent from %s rejected; "
   2225 			"must be from linklocal\n", ip6_sprintf(&src6)));
   2226 		goto bad;
   2227 	}
   2228 	if (ip6->ip6_hlim != 255) {
   2229 		nd6log((LOG_ERR,
   2230 			"ICMP6 redirect sent from %s rejected; "
   2231 			"hlim=%d (must be 255)\n",
   2232 			ip6_sprintf(&src6), ip6->ip6_hlim));
   2233 		goto bad;
   2234 	}
   2235     {
   2236 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
   2237 	struct sockaddr_in6 sin6;
   2238 	struct in6_addr *gw6;
   2239 
   2240 	bzero(&sin6, sizeof(sin6));
   2241 	sin6.sin6_family = AF_INET6;
   2242 	sin6.sin6_len = sizeof(struct sockaddr_in6);
   2243 	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
   2244 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
   2245 	if (rt) {
   2246 		if (rt->rt_gateway == NULL ||
   2247 		    rt->rt_gateway->sa_family != AF_INET6) {
   2248 			nd6log((LOG_ERR,
   2249 			    "ICMP6 redirect rejected; no route "
   2250 			    "with inet6 gateway found for redirect dst: %s\n",
   2251 			    icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
   2252 			RTFREE(rt);
   2253 			goto bad;
   2254 		}
   2255 
   2256 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
   2257 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
   2258 			nd6log((LOG_ERR,
   2259 				"ICMP6 redirect rejected; "
   2260 				"not equal to gw-for-src=%s (must be same): "
   2261 				"%s\n",
   2262 				ip6_sprintf(gw6),
   2263 				icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
   2264 			RTFREE(rt);
   2265 			goto bad;
   2266 		}
   2267 	} else {
   2268 		nd6log((LOG_ERR,
   2269 			"ICMP6 redirect rejected; "
   2270 			"no route found for redirect dst: %s\n",
   2271 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
   2272 		goto bad;
   2273 	}
   2274 	RTFREE(rt);
   2275 	rt = NULL;
   2276     }
   2277 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
   2278 		nd6log((LOG_ERR,
   2279 			"ICMP6 redirect rejected; "
   2280 			"redirect dst must be unicast: %s\n",
   2281 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
   2282 		goto bad;
   2283 	}
   2284 
   2285 	is_router = is_onlink = 0;
   2286 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
   2287 		is_router = 1;	/* router case */
   2288 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
   2289 		is_onlink = 1;	/* on-link destination case */
   2290 	if (!is_router && !is_onlink) {
   2291 		nd6log((LOG_ERR,
   2292 			"ICMP6 redirect rejected; "
   2293 			"neither router case nor onlink case: %s\n",
   2294 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
   2295 		goto bad;
   2296 	}
   2297 	/* validation passed */
   2298 
   2299 	icmp6len -= sizeof(*nd_rd);
   2300 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
   2301 	if (nd6_options(&ndopts) < 0) {
   2302 		nd6log((LOG_INFO, "icmp6_redirect_input: "
   2303 			"invalid ND option, rejected: %s\n",
   2304 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
   2305 		/* nd6_options have incremented stats */
   2306 		goto freeit;
   2307 	}
   2308 
   2309 	if (ndopts.nd_opts_tgt_lladdr) {
   2310 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
   2311 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
   2312 	}
   2313 
   2314 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
   2315 		nd6log((LOG_INFO,
   2316 			"icmp6_redirect_input: lladdrlen mismatch for %s "
   2317 			"(if %d, icmp6 packet %d): %s\n",
   2318 			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
   2319 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
   2320 		goto bad;
   2321 	}
   2322 
   2323 	/* RFC 2461 8.3 */
   2324 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
   2325 			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
   2326 
   2327 	if (!is_onlink) {	/* better router case.  perform rtredirect. */
   2328 		/* perform rtredirect */
   2329 		struct sockaddr_in6 sdst;
   2330 		struct sockaddr_in6 sgw;
   2331 		struct sockaddr_in6 ssrc;
   2332 		unsigned long rtcount;
   2333 		struct rtentry *newrt = NULL;
   2334 
   2335 		/*
   2336 		 * do not install redirect route, if the number of entries
   2337 		 * is too much (> hiwat).  note that, the node (= host) will
   2338 		 * work just fine even if we do not install redirect route
   2339 		 * (there will be additional hops, though).
   2340 		 */
   2341 		rtcount = rt_timer_count(icmp6_redirect_timeout_q);
   2342 		if (0 <= icmp6_redirect_hiwat && rtcount > icmp6_redirect_hiwat)
   2343 			return;
   2344 		else if (0 <= icmp6_redirect_lowat &&
   2345 		    rtcount > icmp6_redirect_lowat) {
   2346 			/*
   2347 			 * XXX nuke a victim, install the new one.
   2348 			 */
   2349 		}
   2350 
   2351 		bzero(&sdst, sizeof(sdst));
   2352 		bzero(&sgw, sizeof(sgw));
   2353 		bzero(&ssrc, sizeof(ssrc));
   2354 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
   2355 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
   2356 			sizeof(struct sockaddr_in6);
   2357 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
   2358 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
   2359 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
   2360 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
   2361 			   (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
   2362 			   (struct sockaddr *)&ssrc,
   2363 			   &newrt);
   2364 
   2365 		if (newrt) {
   2366 			(void)rt_timer_add(newrt, icmp6_redirect_timeout,
   2367 			    icmp6_redirect_timeout_q);
   2368 			rtfree(newrt);
   2369 		}
   2370 	}
   2371 	/* finally update cached route in each socket via pfctlinput */
   2372 	{
   2373 		struct sockaddr_in6 sdst;
   2374 
   2375 		bzero(&sdst, sizeof(sdst));
   2376 		sdst.sin6_family = AF_INET6;
   2377 		sdst.sin6_len = sizeof(struct sockaddr_in6);
   2378 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
   2379 		pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
   2380 #ifdef IPSEC
   2381 		key_sa_routechange((struct sockaddr *)&sdst);
   2382 #endif
   2383 	}
   2384 
   2385  freeit:
   2386 	m_freem(m);
   2387 	return;
   2388 
   2389  bad:
   2390 	icmp6stat.icp6s_badredirect++;
   2391 	m_freem(m);
   2392 }
   2393 
   2394 void
   2395 icmp6_redirect_output(m0, rt)
   2396 	struct mbuf *m0;
   2397 	struct rtentry *rt;
   2398 {
   2399 	struct ifnet *ifp;	/* my outgoing interface */
   2400 	struct in6_addr *ifp_ll6;
   2401 	struct in6_addr *nexthop;
   2402 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
   2403 	struct mbuf *m = NULL;	/* newly allocated one */
   2404 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
   2405 	struct nd_redirect *nd_rd;
   2406 	size_t maxlen;
   2407 	u_char *p;
   2408 	struct sockaddr_in6 src_sa;
   2409 
   2410 	icmp6_errcount(&icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);
   2411 
   2412 	/* if we are not router, we don't send icmp6 redirect */
   2413 	if (!ip6_forwarding)
   2414 		goto fail;
   2415 
   2416 	/* sanity check */
   2417 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
   2418 		goto fail;
   2419 
   2420 	/*
   2421 	 * Address check:
   2422 	 *  the source address must identify a neighbor, and
   2423 	 *  the destination address must not be a multicast address
   2424 	 *  [RFC 2461, sec 8.2]
   2425 	 */
   2426 	sip6 = mtod(m0, struct ip6_hdr *);
   2427 	bzero(&src_sa, sizeof(src_sa));
   2428 	src_sa.sin6_family = AF_INET6;
   2429 	src_sa.sin6_len = sizeof(src_sa);
   2430 	src_sa.sin6_addr = sip6->ip6_src;
   2431 	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
   2432 		goto fail;
   2433 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
   2434 		goto fail;	/* what should we do here? */
   2435 
   2436 	/* rate limit */
   2437 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
   2438 		goto fail;
   2439 
   2440 	/*
   2441 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
   2442 	 * we almost always ask for an mbuf cluster for simplicity.
   2443 	 * (MHLEN < IPV6_MMTU is almost always true)
   2444 	 */
   2445 #if IPV6_MMTU >= MCLBYTES
   2446 # error assumption failed about IPV6_MMTU and MCLBYTES
   2447 #endif
   2448 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
   2449 	if (m && IPV6_MMTU >= MHLEN)
   2450 		MCLGET(m, M_DONTWAIT);
   2451 	if (!m)
   2452 		goto fail;
   2453 	m->m_pkthdr.rcvif = NULL;
   2454 	m->m_len = 0;
   2455 	maxlen = M_TRAILINGSPACE(m);
   2456 	maxlen = min(IPV6_MMTU, maxlen);
   2457 	/* just for safety */
   2458 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
   2459 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
   2460 		goto fail;
   2461 	}
   2462 
   2463 	{
   2464 		/* get ip6 linklocal address for ifp(my outgoing interface). */
   2465 		struct in6_ifaddr *ia;
   2466 		if ((ia = in6ifa_ifpforlinklocal(ifp,
   2467 						 IN6_IFF_NOTREADY|
   2468 						 IN6_IFF_ANYCAST)) == NULL)
   2469 			goto fail;
   2470 		ifp_ll6 = &ia->ia_addr.sin6_addr;
   2471 	}
   2472 
   2473 	/* get ip6 linklocal address for the router. */
   2474 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
   2475 		struct sockaddr_in6 *sin6;
   2476 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
   2477 		nexthop = &sin6->sin6_addr;
   2478 		if (!IN6_IS_ADDR_LINKLOCAL(nexthop))
   2479 			nexthop = NULL;
   2480 	} else
   2481 		nexthop = NULL;
   2482 
   2483 	/* ip6 */
   2484 	ip6 = mtod(m, struct ip6_hdr *);
   2485 	ip6->ip6_flow = 0;
   2486 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
   2487 	ip6->ip6_vfc |= IPV6_VERSION;
   2488 	/* ip6->ip6_plen will be set later */
   2489 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   2490 	ip6->ip6_hlim = 255;
   2491 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
   2492 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
   2493 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
   2494 
   2495 	/* ND Redirect */
   2496 	nd_rd = (struct nd_redirect *)(ip6 + 1);
   2497 	nd_rd->nd_rd_type = ND_REDIRECT;
   2498 	nd_rd->nd_rd_code = 0;
   2499 	nd_rd->nd_rd_reserved = 0;
   2500 	if (rt->rt_flags & RTF_GATEWAY) {
   2501 		/*
   2502 		 * nd_rd->nd_rd_target must be a link-local address in
   2503 		 * better router cases.
   2504 		 */
   2505 		if (!nexthop)
   2506 			goto fail;
   2507 		bcopy(nexthop, &nd_rd->nd_rd_target,
   2508 		      sizeof(nd_rd->nd_rd_target));
   2509 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
   2510 		      sizeof(nd_rd->nd_rd_dst));
   2511 	} else {
   2512 		/* make sure redtgt == reddst */
   2513 		nexthop = &sip6->ip6_dst;
   2514 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
   2515 		      sizeof(nd_rd->nd_rd_target));
   2516 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
   2517 		      sizeof(nd_rd->nd_rd_dst));
   2518 	}
   2519 
   2520 	p = (u_char *)(nd_rd + 1);
   2521 
   2522 	{
   2523 		/* target lladdr option */
   2524 		struct rtentry *rt_nexthop = NULL;
   2525 		int len;
   2526 		struct sockaddr_dl *sdl;
   2527 		struct nd_opt_hdr *nd_opt;
   2528 		char *lladdr;
   2529 
   2530 		rt_nexthop = nd6_lookup(nexthop, 0, ifp);
   2531 		if (!rt_nexthop)
   2532 			goto nolladdropt;
   2533 		len = sizeof(*nd_opt) + ifp->if_addrlen;
   2534 		len = (len + 7) & ~7;	/* round by 8 */
   2535 		/* safety check */
   2536 		if (len + (p - (u_char *)ip6) > maxlen)
   2537 			goto nolladdropt;
   2538 		if (!(rt_nexthop->rt_flags & RTF_GATEWAY) &&
   2539 		    (rt_nexthop->rt_flags & RTF_LLINFO) &&
   2540 		    (rt_nexthop->rt_gateway->sa_family == AF_LINK) &&
   2541 		    (sdl = (struct sockaddr_dl *)rt_nexthop->rt_gateway) &&
   2542 		    sdl->sdl_alen) {
   2543 			nd_opt = (struct nd_opt_hdr *)p;
   2544 			nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
   2545 			nd_opt->nd_opt_len = len >> 3;
   2546 			lladdr = (char *)(nd_opt + 1);
   2547 			bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
   2548 			p += len;
   2549 		}
   2550 	}
   2551   nolladdropt:;
   2552 
   2553 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
   2554 
   2555 	/* just to be safe */
   2556 	if (m0->m_flags & M_DECRYPTED)
   2557 		goto noredhdropt;
   2558 	if (p - (u_char *)ip6 > maxlen)
   2559 		goto noredhdropt;
   2560 
   2561 	{
   2562 		/* redirected header option */
   2563 		int len;
   2564 		struct nd_opt_rd_hdr *nd_opt_rh;
   2565 
   2566 		/*
   2567 		 * compute the maximum size for icmp6 redirect header option.
   2568 		 * XXX room for auth header?
   2569 		 */
   2570 		len = maxlen - (p - (u_char *)ip6);
   2571 		len &= ~7;
   2572 
   2573 		/*
   2574 		 * Redirected header option spec (RFC2461 4.6.3) talks nothing
   2575 		 * about padding/truncate rule for the original IP packet.
   2576 		 * From the discussion on IPv6imp in Feb 1999,
   2577 		 * the consensus was:
   2578 		 * - "attach as much as possible" is the goal
   2579 		 * - pad if not aligned (original size can be guessed by
   2580 		 *   original ip6 header)
   2581 		 * Following code adds the padding if it is simple enough,
   2582 		 * and truncates if not.
   2583 		 */
   2584 		if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
   2585 			/* not enough room, truncate */
   2586 			m_adj(m0, (len - sizeof(*nd_opt_rh)) -
   2587 			    m0->m_pkthdr.len);
   2588 		} else {
   2589 			/*
   2590 			 * enough room, truncate if not aligned.
   2591 			 * we don't pad here for simplicity.
   2592 			 */
   2593 			size_t extra;
   2594 
   2595 			extra = m0->m_pkthdr.len % 8;
   2596 			if (extra) {
   2597 				/* truncate */
   2598 				m_adj(m0, -extra);
   2599 			}
   2600 			len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
   2601 		}
   2602 
   2603 		nd_opt_rh = (struct nd_opt_rd_hdr *)p;
   2604 		bzero(nd_opt_rh, sizeof(*nd_opt_rh));
   2605 		nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
   2606 		nd_opt_rh->nd_opt_rh_len = len >> 3;
   2607 		p += sizeof(*nd_opt_rh);
   2608 		m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
   2609 
   2610 		/* connect m0 to m */
   2611 		m->m_pkthdr.len += m0->m_pkthdr.len;
   2612 		m_cat(m, m0);
   2613 		m0 = NULL;
   2614 	}
   2615 noredhdropt:
   2616 	if (m0) {
   2617 		m_freem(m0);
   2618 		m0 = NULL;
   2619 	}
   2620 
   2621 	/* XXX: clear embedded link IDs in the inner header */
   2622 	in6_clearscope(&sip6->ip6_src);
   2623 	in6_clearscope(&sip6->ip6_dst);
   2624 	in6_clearscope(&nd_rd->nd_rd_target);
   2625 	in6_clearscope(&nd_rd->nd_rd_dst);
   2626 
   2627 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
   2628 
   2629 	nd_rd->nd_rd_cksum = 0;
   2630 	nd_rd->nd_rd_cksum
   2631 		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
   2632 
   2633 	/* send the packet to outside... */
   2634 	if (ip6_output(m, NULL, NULL, 0,
   2635 		(struct ip6_moptions *)NULL, (struct socket *)NULL, NULL) != 0)
   2636 		icmp6_ifstat_inc(ifp, ifs6_out_error);
   2637 
   2638 	icmp6_ifstat_inc(ifp, ifs6_out_msg);
   2639 	icmp6_ifstat_inc(ifp, ifs6_out_redirect);
   2640 	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
   2641 
   2642 	return;
   2643 
   2644 fail:
   2645 	if (m)
   2646 		m_freem(m);
   2647 	if (m0)
   2648 		m_freem(m0);
   2649 }
   2650 
   2651 /*
   2652  * ICMPv6 socket option processing.
   2653  */
   2654 int
   2655 icmp6_ctloutput(op, so, level, optname, mp)
   2656 	int op;
   2657 	struct socket *so;
   2658 	int level, optname;
   2659 	struct mbuf **mp;
   2660 {
   2661 	int error = 0;
   2662 	int optlen;
   2663 	struct in6pcb *in6p = sotoin6pcb(so);
   2664 	struct mbuf *m = *mp;
   2665 
   2666 	optlen = m ? m->m_len : 0;
   2667 
   2668 	if (level != IPPROTO_ICMPV6) {
   2669 		if (op == PRCO_SETOPT && m)
   2670 			(void)m_free(m);
   2671 		return EINVAL;
   2672 	}
   2673 
   2674 	switch (op) {
   2675 	case PRCO_SETOPT:
   2676 		switch (optname) {
   2677 		case ICMP6_FILTER:
   2678 		    {
   2679 			struct icmp6_filter *p;
   2680 
   2681 			if (optlen != sizeof(*p)) {
   2682 				error = EMSGSIZE;
   2683 				break;
   2684 			}
   2685 			p = mtod(m, struct icmp6_filter *);
   2686 			if (!p || !in6p->in6p_icmp6filt) {
   2687 				error = EINVAL;
   2688 				break;
   2689 			}
   2690 			bcopy(p, in6p->in6p_icmp6filt,
   2691 				sizeof(struct icmp6_filter));
   2692 			error = 0;
   2693 			break;
   2694 		    }
   2695 
   2696 		default:
   2697 			error = ENOPROTOOPT;
   2698 			break;
   2699 		}
   2700 		if (m)
   2701 			(void)m_freem(m);
   2702 		break;
   2703 
   2704 	case PRCO_GETOPT:
   2705 		switch (optname) {
   2706 		case ICMP6_FILTER:
   2707 		    {
   2708 			struct icmp6_filter *p;
   2709 
   2710 			if (!in6p->in6p_icmp6filt) {
   2711 				error = EINVAL;
   2712 				break;
   2713 			}
   2714 			*mp = m = m_get(M_WAIT, MT_SOOPTS);
   2715 			m->m_len = sizeof(struct icmp6_filter);
   2716 			p = mtod(m, struct icmp6_filter *);
   2717 			bcopy(in6p->in6p_icmp6filt, p,
   2718 				sizeof(struct icmp6_filter));
   2719 			error = 0;
   2720 			break;
   2721 		    }
   2722 
   2723 		default:
   2724 			error = ENOPROTOOPT;
   2725 			break;
   2726 		}
   2727 		break;
   2728 	}
   2729 
   2730 	return (error);
   2731 }
   2732 
   2733 /*
   2734  * Perform rate limit check.
   2735  * Returns 0 if it is okay to send the icmp6 packet.
   2736  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
   2737  * limitation.
   2738  *
   2739  * XXX per-destination/type check necessary?
   2740  */
   2741 static int
   2742 icmp6_ratelimit(dst, type, code)
   2743 	const struct in6_addr *dst;	/* not used at this moment */
   2744 	const int type;			/* not used at this moment */
   2745 	const int code;			/* not used at this moment */
   2746 {
   2747 	int ret;
   2748 
   2749 	ret = 0;	/* okay to send */
   2750 
   2751 	/* PPS limit */
   2752 	if (!ppsratecheck(&icmp6errppslim_last, &icmp6errpps_count,
   2753 	    icmp6errppslim)) {
   2754 		/* The packet is subject to rate limit */
   2755 		ret++;
   2756 	}
   2757 
   2758 	return ret;
   2759 }
   2760 
   2761 static struct rtentry *
   2762 icmp6_mtudisc_clone(dst)
   2763 	struct sockaddr *dst;
   2764 {
   2765 	struct rtentry *rt;
   2766 	int    error;
   2767 
   2768 	rt = rtalloc1(dst, 1);
   2769 	if (rt == 0)
   2770 		return NULL;
   2771 
   2772 	/* If we didn't get a host route, allocate one */
   2773 	if ((rt->rt_flags & RTF_HOST) == 0) {
   2774 		struct rtentry *nrt;
   2775 
   2776 		error = rtrequest((int) RTM_ADD, dst,
   2777 		    (struct sockaddr *) rt->rt_gateway,
   2778 		    (struct sockaddr *) 0,
   2779 		    RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
   2780 		if (error) {
   2781 			rtfree(rt);
   2782 			return NULL;
   2783 		}
   2784 		nrt->rt_rmx = rt->rt_rmx;
   2785 		rtfree(rt);
   2786 		rt = nrt;
   2787 	}
   2788 	error = rt_timer_add(rt, icmp6_mtudisc_timeout,
   2789 			icmp6_mtudisc_timeout_q);
   2790 	if (error) {
   2791 		rtfree(rt);
   2792 		return NULL;
   2793 	}
   2794 
   2795 	return rt;	/* caller need to call rtfree() */
   2796 }
   2797 
   2798 static void
   2799 icmp6_mtudisc_timeout(rt, r)
   2800 	struct rtentry *rt;
   2801 	struct rttimer *r;
   2802 {
   2803 	if (rt == NULL)
   2804 		panic("icmp6_mtudisc_timeout: bad route to timeout");
   2805 	if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
   2806 	    (RTF_DYNAMIC | RTF_HOST)) {
   2807 		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
   2808 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
   2809 	} else {
   2810 		if (!(rt->rt_rmx.rmx_locks & RTV_MTU))
   2811 			rt->rt_rmx.rmx_mtu = 0;
   2812 	}
   2813 }
   2814 
   2815 static void
   2816 icmp6_redirect_timeout(rt, r)
   2817 	struct rtentry *rt;
   2818 	struct rttimer *r;
   2819 {
   2820 	if (rt == NULL)
   2821 		panic("icmp6_redirect_timeout: bad route to timeout");
   2822 	if ((rt->rt_flags & (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) ==
   2823 	    (RTF_GATEWAY | RTF_DYNAMIC | RTF_HOST)) {
   2824 		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
   2825 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
   2826 	}
   2827 }
   2828 
   2829 /*
   2830  * sysctl helper routine for the net.inet6.icmp6.nd6 nodes.  silly?
   2831  */
   2832 static int
   2833 sysctl_net_inet6_icmp6_nd6(SYSCTLFN_ARGS)
   2834 {
   2835 
   2836 	if (namelen != 0)
   2837 		return (EINVAL);
   2838 
   2839 	return (nd6_sysctl(rnode->sysctl_num, oldp, oldlenp,
   2840 	    /*XXXUNCONST*/
   2841 	    __UNCONST(newp), newlen));
   2842 }
   2843 
   2844 SYSCTL_SETUP(sysctl_net_inet6_icmp6_setup,
   2845 	     "sysctl net.inet6.icmp6 subtree setup")
   2846 {
   2847 	extern int nd6_maxqueuelen; /* defined in nd6.c */
   2848 
   2849 	sysctl_createv(clog, 0, NULL, NULL,
   2850 		       CTLFLAG_PERMANENT,
   2851 		       CTLTYPE_NODE, "net", NULL,
   2852 		       NULL, 0, NULL, 0,
   2853 		       CTL_NET, CTL_EOL);
   2854 	sysctl_createv(clog, 0, NULL, NULL,
   2855 		       CTLFLAG_PERMANENT,
   2856 		       CTLTYPE_NODE, "inet6", NULL,
   2857 		       NULL, 0, NULL, 0,
   2858 		       CTL_NET, PF_INET6, CTL_EOL);
   2859 	sysctl_createv(clog, 0, NULL, NULL,
   2860 		       CTLFLAG_PERMANENT,
   2861 		       CTLTYPE_NODE, "icmp6",
   2862 		       SYSCTL_DESCR("ICMPv6 related settings"),
   2863 		       NULL, 0, NULL, 0,
   2864 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6, CTL_EOL);
   2865 
   2866 	sysctl_createv(clog, 0, NULL, NULL,
   2867 		       CTLFLAG_PERMANENT,
   2868 		       CTLTYPE_STRUCT, "stats",
   2869 		       SYSCTL_DESCR("ICMPv6 transmission statistics"),
   2870 		       NULL, 0, &icmp6stat, sizeof(icmp6stat),
   2871 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2872 		       ICMPV6CTL_STATS, CTL_EOL);
   2873 	sysctl_createv(clog, 0, NULL, NULL,
   2874 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2875 		       CTLTYPE_INT, "rediraccept",
   2876 		       SYSCTL_DESCR("Accept and process redirect messages"),
   2877 		       NULL, 0, &icmp6_rediraccept, 0,
   2878 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2879 		       ICMPV6CTL_REDIRACCEPT, CTL_EOL);
   2880 	sysctl_createv(clog, 0, NULL, NULL,
   2881 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2882 		       CTLTYPE_INT, "redirtimeout",
   2883 		       SYSCTL_DESCR("Redirect generated route lifetime"),
   2884 		       NULL, 0, &icmp6_redirtimeout, 0,
   2885 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2886 		       ICMPV6CTL_REDIRTIMEOUT, CTL_EOL);
   2887 #if 0 /* obsoleted */
   2888 	sysctl_createv(clog, 0, NULL, NULL,
   2889 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2890 		       CTLTYPE_INT, "errratelimit", NULL,
   2891 		       NULL, 0, &icmp6_errratelimit, 0,
   2892 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2893 		       ICMPV6CTL_ERRRATELIMIT, CTL_EOL);
   2894 #endif
   2895 	sysctl_createv(clog, 0, NULL, NULL,
   2896 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2897 		       CTLTYPE_INT, "nd6_prune",
   2898 		       SYSCTL_DESCR("Neighbor discovery prune interval"),
   2899 		       NULL, 0, &nd6_prune, 0,
   2900 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2901 		       ICMPV6CTL_ND6_PRUNE, CTL_EOL);
   2902 	sysctl_createv(clog, 0, NULL, NULL,
   2903 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2904 		       CTLTYPE_INT, "nd6_delay",
   2905 		       SYSCTL_DESCR("First probe delay time"),
   2906 		       NULL, 0, &nd6_delay, 0,
   2907 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2908 		       ICMPV6CTL_ND6_DELAY, CTL_EOL);
   2909 	sysctl_createv(clog, 0, NULL, NULL,
   2910 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2911 		       CTLTYPE_INT, "nd6_umaxtries",
   2912 		       SYSCTL_DESCR("Number of unicast discovery attempts"),
   2913 		       NULL, 0, &nd6_umaxtries, 0,
   2914 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2915 		       ICMPV6CTL_ND6_UMAXTRIES, CTL_EOL);
   2916 	sysctl_createv(clog, 0, NULL, NULL,
   2917 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2918 		       CTLTYPE_INT, "nd6_mmaxtries",
   2919 		       SYSCTL_DESCR("Number of multicast discovery attempts"),
   2920 		       NULL, 0, &nd6_mmaxtries, 0,
   2921 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2922 		       ICMPV6CTL_ND6_MMAXTRIES, CTL_EOL);
   2923 	sysctl_createv(clog, 0, NULL, NULL,
   2924 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2925 		       CTLTYPE_INT, "nd6_useloopback",
   2926 		       SYSCTL_DESCR("Use loopback interface for local traffic"),
   2927 		       NULL, 0, &nd6_useloopback, 0,
   2928 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2929 		       ICMPV6CTL_ND6_USELOOPBACK, CTL_EOL);
   2930 #if 0 /* obsoleted */
   2931 	sysctl_createv(clog, 0, NULL, NULL,
   2932 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2933 		       CTLTYPE_INT, "nd6_proxyall", NULL,
   2934 		       NULL, 0, &nd6_proxyall, 0,
   2935 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2936 		       ICMPV6CTL_ND6_PROXYALL, CTL_EOL);
   2937 #endif
   2938 	sysctl_createv(clog, 0, NULL, NULL,
   2939 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2940 		       CTLTYPE_INT, "nodeinfo",
   2941 		       SYSCTL_DESCR("Respond to node information requests"),
   2942 		       NULL, 0, &icmp6_nodeinfo, 0,
   2943 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2944 		       ICMPV6CTL_NODEINFO, CTL_EOL);
   2945 	sysctl_createv(clog, 0, NULL, NULL,
   2946 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2947 		       CTLTYPE_INT, "errppslimit",
   2948 		       SYSCTL_DESCR("Maximum ICMP errors sent per second"),
   2949 		       NULL, 0, &icmp6errppslim, 0,
   2950 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2951 		       ICMPV6CTL_ERRPPSLIMIT, CTL_EOL);
   2952 	sysctl_createv(clog, 0, NULL, NULL,
   2953 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2954 		       CTLTYPE_INT, "nd6_maxnudhint",
   2955 		       SYSCTL_DESCR("Maximum neighbor unreachable hint count"),
   2956 		       NULL, 0, &nd6_maxnudhint, 0,
   2957 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2958 		       ICMPV6CTL_ND6_MAXNUDHINT, CTL_EOL);
   2959 	sysctl_createv(clog, 0, NULL, NULL,
   2960 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2961 		       CTLTYPE_INT, "mtudisc_hiwat",
   2962 		       SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
   2963 		       NULL, 0, &icmp6_mtudisc_hiwat, 0,
   2964 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2965 		       ICMPV6CTL_MTUDISC_HIWAT, CTL_EOL);
   2966 	sysctl_createv(clog, 0, NULL, NULL,
   2967 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2968 		       CTLTYPE_INT, "mtudisc_lowat",
   2969 		       SYSCTL_DESCR("Low mark on MTU Discovery route timers"),
   2970 		       NULL, 0, &icmp6_mtudisc_lowat, 0,
   2971 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2972 		       ICMPV6CTL_MTUDISC_LOWAT, CTL_EOL);
   2973 	sysctl_createv(clog, 0, NULL, NULL,
   2974 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2975 		       CTLTYPE_INT, "nd6_debug",
   2976 		       SYSCTL_DESCR("Enable neighbor discovery debug output"),
   2977 		       NULL, 0, &nd6_debug, 0,
   2978 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2979 		       ICMPV6CTL_ND6_DEBUG, CTL_EOL);
   2980 	sysctl_createv(clog, 0, NULL, NULL,
   2981 		       CTLFLAG_PERMANENT,
   2982 		       CTLTYPE_STRUCT, "nd6_drlist",
   2983 		       SYSCTL_DESCR("Default router list"),
   2984 		       sysctl_net_inet6_icmp6_nd6, 0, NULL, 0,
   2985 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2986 		       ICMPV6CTL_ND6_DRLIST, CTL_EOL);
   2987 	sysctl_createv(clog, 0, NULL, NULL,
   2988 		       CTLFLAG_PERMANENT,
   2989 		       CTLTYPE_STRUCT, "nd6_prlist",
   2990 		       SYSCTL_DESCR("Prefix list"),
   2991 		       sysctl_net_inet6_icmp6_nd6, 0, NULL, 0,
   2992 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   2993 		       ICMPV6CTL_ND6_PRLIST, CTL_EOL);
   2994 	sysctl_createv(clog, 0, NULL, NULL,
   2995 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
   2996 		       CTLTYPE_INT, "maxqueuelen",
   2997 		       SYSCTL_DESCR("max packet queue len for a unresolved ND"),
   2998 		       NULL, 1, &nd6_maxqueuelen, 0,
   2999 		       CTL_NET, PF_INET6, IPPROTO_ICMPV6,
   3000 		       ICMPV6CTL_ND6_MAXQLEN, CTL_EOL);
   3001 }
   3002