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icmp6.c revision 1.26
      1 /*	$NetBSD: icmp6.c,v 1.26 2000/03/01 12:49:44 itojun Exp $	*/
      2 /*	$KAME: icmp6.c,v 1.71 2000/02/28 09:25:42 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. All advertising materials mentioning features or use of this software
     46  *    must display the following acknowledgement:
     47  *	This product includes software developed by the University of
     48  *	California, Berkeley and its contributors.
     49  * 4. Neither the name of the University nor the names of its contributors
     50  *    may be used to endorse or promote products derived from this software
     51  *    without specific prior written permission.
     52  *
     53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     63  * SUCH DAMAGE.
     64  *
     65  *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
     66  */
     67 
     68 #include "opt_inet.h"
     69 #include "opt_ipsec.h"
     70 
     71 #include <sys/param.h>
     72 #include <sys/systm.h>
     73 #include <sys/malloc.h>
     74 #include <sys/mbuf.h>
     75 #include <sys/protosw.h>
     76 #include <sys/socket.h>
     77 #include <sys/socketvar.h>
     78 #include <sys/time.h>
     79 #include <sys/kernel.h>
     80 #include <sys/syslog.h>
     81 #include <sys/domain.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 
     99 
    100 #ifdef IPSEC
    101 #include <netinet6/ipsec.h>
    102 #include <netkey/key.h>
    103 #include <netkey/key_debug.h>
    104 #endif
    105 
    106 #include "faith.h"
    107 
    108 #include <net/net_osdep.h>
    109 
    110 extern struct domain inet6domain;
    111 
    112 struct icmp6stat icmp6stat;
    113 
    114 extern struct in6pcb rawin6pcb;
    115 extern struct timeval icmp6errratelim;
    116 extern int icmp6_nodeinfo;
    117 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
    118 extern int pmtu_expire;
    119 
    120 static int icmp6_rip6_input __P((struct mbuf **, int));
    121 static void icmp6_mtudisc_update __P((struct in6_addr *, struct icmp6_hdr *,
    122 				      struct mbuf *));
    123 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
    124 static const char *icmp6_redirect_diag __P((struct in6_addr *,
    125 	struct in6_addr *, struct in6_addr *));
    126 static struct mbuf * ni6_input __P((struct mbuf *, int));
    127 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
    128 			  struct ifnet **));
    129 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
    130 				struct ifnet *, int));
    131 static struct rtentry *icmp6_mtudisc_clone __P((struct sockaddr *));
    132 static void icmp6_mtudisc_timeout __P((struct rtentry *, struct rttimer *));
    133 
    134 #ifdef COMPAT_RFC1885
    135 static struct route_in6 icmp6_reflect_rt;
    136 #endif
    137 
    138 void
    139 icmp6_init()
    140 {
    141 	mld6_init();
    142 	icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
    143 }
    144 
    145 /*
    146  * Generate an error packet of type error in response to bad IP6 packet.
    147  */
    148 void
    149 icmp6_error(m, type, code, param)
    150 	struct mbuf *m;
    151 	int type, code, param;
    152 {
    153 	struct ip6_hdr *oip6, *nip6;
    154 	struct icmp6_hdr *icmp6;
    155 	u_int preplen;
    156 	int off;
    157 	u_char nxt;
    158 
    159 	icmp6stat.icp6s_error++;
    160 
    161 	if (m->m_flags & M_DECRYPTED) {
    162 		icmp6stat.icp6s_canterror++;
    163 		goto freeit;
    164 	}
    165 
    166 #ifndef PULLDOWN_TEST
    167 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
    168 #else
    169 	if (m->m_len < sizeof(struct ip6_hdr)) {
    170 		m = m_pullup(m, sizeof(struct ip6_hdr));
    171 		if (m == NULL)
    172 			return;
    173 	}
    174 #endif
    175 	oip6 = mtod(m, struct ip6_hdr *);
    176 
    177 	/*
    178 	 * Multicast destination check. For unrecognized option errors,
    179 	 * this check has already done in ip6_unknown_opt(), so we can
    180 	 * check only for other errors.
    181 	 */
    182 	if ((m->m_flags & (M_BCAST|M_MCAST) ||
    183 	     IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
    184 	    (type != ICMP6_PACKET_TOO_BIG &&
    185 	     (type != ICMP6_PARAM_PROB ||
    186 	      code != ICMP6_PARAMPROB_OPTION)))
    187 		goto freeit;
    188 
    189 	/* Source address check. XXX: the case of anycast source? */
    190 	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) ||
    191 	    IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
    192 		goto freeit;
    193 
    194 	/*
    195 	 * If the erroneous packet is also an ICMP error, discard it.
    196 	 */
    197 	off = sizeof(struct ip6_hdr);
    198 	nxt = oip6->ip6_nxt;
    199 	while (1) {		/* XXX: should avoid inf. loop explicitly? */
    200 		struct ip6_ext *ip6e;
    201 		struct icmp6_hdr *icp;
    202 
    203 		switch(nxt) {
    204 		case IPPROTO_IPV6:
    205 		case IPPROTO_IPV4:
    206 		case IPPROTO_UDP:
    207 		case IPPROTO_TCP:
    208 		case IPPROTO_ESP:
    209 		case IPPROTO_IPCOMP:
    210 		case IPPROTO_FRAGMENT:
    211 			/*
    212 			 * ICMPv6 error must not be fragmented.
    213 			 * XXX: but can we trust the sender?
    214 			 */
    215 		default:
    216 			/* What if unknown header followed by ICMP error? */
    217 			goto generate;
    218 		case IPPROTO_ICMPV6:
    219 #ifndef PULLDOWN_TEST
    220 			IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
    221 			icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
    222 #else
    223 			IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
    224 				sizeof(*icp));
    225 			if (icp == NULL) {
    226 				icmp6stat.icp6s_tooshort++;
    227 				return;
    228 			}
    229 #endif
    230 			if (icp->icmp6_type < ICMP6_ECHO_REQUEST
    231 			 || icp->icmp6_type == ND_REDIRECT) {
    232 				/*
    233 				 * ICMPv6 error
    234 				 * Special case: for redirect (which is
    235 				 * informational) we must not send icmp6 error.
    236 				 */
    237 				icmp6stat.icp6s_canterror++;
    238 				goto freeit;
    239 			} else {
    240 				/* ICMPv6 informational */
    241 				goto generate;
    242 			}
    243 		case IPPROTO_HOPOPTS:
    244 		case IPPROTO_DSTOPTS:
    245 		case IPPROTO_ROUTING:
    246 		case IPPROTO_AH:
    247 #ifndef PULLDOWN_TEST
    248 			IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct ip6_ext), );
    249 			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
    250 #else
    251 			IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off,
    252 				sizeof(*ip6e));
    253 			if (ip6e == NULL) {
    254 				/*XXX stat */
    255 				return;
    256 			}
    257 #endif
    258 			if (nxt == IPPROTO_AH)
    259 				off += (ip6e->ip6e_len + 2) << 2;
    260 			else
    261 				off += (ip6e->ip6e_len + 1) << 3;
    262 			nxt = ip6e->ip6e_nxt;
    263 			break;
    264 		}
    265 	}
    266 
    267   freeit:
    268 	/*
    269 	 * If we can't tell wheter or not we can generate ICMP6, free it.
    270 	 */
    271 	m_freem(m);
    272 	return;
    273 
    274   generate:
    275 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
    276 
    277 	/* Finally, do rate limitation check. */
    278 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
    279 		icmp6stat.icp6s_toofreq++;
    280 		goto freeit;
    281 	}
    282 
    283 	/*
    284 	 * OK, ICMP6 can be generated.
    285 	 */
    286 
    287 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
    288 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
    289 
    290 	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
    291 	M_PREPEND(m, preplen, M_DONTWAIT);
    292 	if (m && m->m_len < preplen)
    293 		m = m_pullup(m, preplen);
    294 	if (m == NULL) {
    295 		printf("ENOBUFS in icmp6_error %d\n", __LINE__);
    296 		return;
    297 	}
    298 
    299 	nip6 = mtod(m, struct ip6_hdr *);
    300 	nip6->ip6_src  = oip6->ip6_src;
    301 	nip6->ip6_dst  = oip6->ip6_dst;
    302 
    303 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
    304 		oip6->ip6_src.s6_addr16[1] = 0;
    305 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
    306 		oip6->ip6_dst.s6_addr16[1] = 0;
    307 
    308 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
    309 	icmp6->icmp6_type = type;
    310 	icmp6->icmp6_code = code;
    311 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
    312 
    313 	icmp6stat.icp6s_outhist[type]++;
    314 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /*header order: IPv6 - ICMPv6*/
    315 }
    316 
    317 /*
    318  * Process a received ICMP6 message.
    319  */
    320 int
    321 icmp6_input(mp, offp, proto)
    322 	struct mbuf **mp;
    323 	int *offp, proto;
    324 {
    325 	struct mbuf *m = *mp, *n;
    326 	struct ip6_hdr *ip6, *nip6;
    327 	struct icmp6_hdr *icmp6, *nicmp6;
    328 	int off = *offp;
    329 	int icmp6len = m->m_pkthdr.len - *offp;
    330 	int code, sum, noff;
    331 	struct sockaddr_in6 icmp6src;
    332 
    333 #ifndef PULLDOWN_TEST
    334 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
    335 	/* m might change if M_LOOP. So, call mtod after this */
    336 #endif
    337 
    338 	/*
    339 	 * Locate icmp6 structure in mbuf, and check
    340 	 * that not corrupted and of at least minimum length
    341 	 */
    342 
    343 	ip6 = mtod(m, struct ip6_hdr *);
    344 	if (icmp6len < sizeof(struct icmp6_hdr)) {
    345 		icmp6stat.icp6s_tooshort++;
    346 		goto freeit;
    347 	}
    348 
    349 	/*
    350 	 * calculate the checksum
    351 	 */
    352 #ifndef PULLDOWN_TEST
    353 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
    354 #else
    355 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
    356 	if (icmp6 == NULL) {
    357 		icmp6stat.icp6s_tooshort++;
    358 		return IPPROTO_DONE;
    359 	}
    360 #endif
    361 	code = icmp6->icmp6_code;
    362 
    363 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
    364 		log(LOG_ERR,
    365 		    "ICMP6 checksum error(%d|%x) %s\n",
    366 		    icmp6->icmp6_type,
    367 		    sum,
    368 		    ip6_sprintf(&ip6->ip6_src));
    369 		icmp6stat.icp6s_checksum++;
    370 		goto freeit;
    371 	}
    372 
    373 #if defined(NFAITH) && 0 < NFAITH
    374 	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
    375 		/*
    376 		 * Deliver very specific ICMP6 type only.
    377 		 * This is important to deilver TOOBIG.  Otherwise PMTUD
    378 		 * will not work.
    379 		 */
    380 		switch (icmp6->icmp6_type) {
    381 		case ICMP6_DST_UNREACH:
    382 		case ICMP6_PACKET_TOO_BIG:
    383 		case ICMP6_TIME_EXCEEDED:
    384 			break;
    385 		default:
    386 			goto freeit;
    387 		}
    388 	}
    389 #endif
    390 
    391 #ifdef IPSEC
    392 	/* drop it if it does not match the default policy */
    393 	if (ipsec6_in_reject(m, NULL)) {
    394 		ipsecstat.in_polvio++;
    395 		goto freeit;
    396 	}
    397 #endif
    398 
    399 	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
    400 	icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_msg);
    401 	if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
    402 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_error);
    403 
    404 	switch (icmp6->icmp6_type) {
    405 
    406 	case ICMP6_DST_UNREACH:
    407 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_dstunreach);
    408 		switch (code) {
    409 		case ICMP6_DST_UNREACH_NOROUTE:
    410 			code = PRC_UNREACH_NET;
    411 			break;
    412 		case ICMP6_DST_UNREACH_ADMIN:
    413 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_adminprohib);
    414 			code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
    415 			break;
    416 		case ICMP6_DST_UNREACH_ADDR:
    417 			code = PRC_HOSTDEAD;
    418 			break;
    419 #ifdef COMPAT_RFC1885
    420 		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
    421 			code = PRC_UNREACH_SRCFAIL;
    422 			break;
    423 #else
    424 		case ICMP6_DST_UNREACH_BEYONDSCOPE:
    425 			/* I mean "source address was incorrect." */
    426 			code = PRC_PARAMPROB;
    427 			break;
    428 #endif
    429 		case ICMP6_DST_UNREACH_NOPORT:
    430 			code = PRC_UNREACH_PORT;
    431 			break;
    432 		default:
    433 			goto badcode;
    434 		}
    435 		goto deliver;
    436 		break;
    437 
    438 	case ICMP6_PACKET_TOO_BIG:
    439 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_pkttoobig);
    440 		if (code != 0)
    441 			goto badcode;
    442 
    443 		code = PRC_MSGSIZE;
    444 
    445 		/*
    446 		 * Updating the path MTU will be done after examining
    447 		 * intermediate extension headers.
    448 		 */
    449 		goto deliver;
    450 		break;
    451 
    452 	case ICMP6_TIME_EXCEEDED:
    453 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_timeexceed);
    454 		switch (code) {
    455 		case ICMP6_TIME_EXCEED_TRANSIT:
    456 		case ICMP6_TIME_EXCEED_REASSEMBLY:
    457 			code += PRC_TIMXCEED_INTRANS;
    458 			break;
    459 		default:
    460 			goto badcode;
    461 		}
    462 		goto deliver;
    463 		break;
    464 
    465 	case ICMP6_PARAM_PROB:
    466 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_paramprob);
    467 		switch (code) {
    468 		case ICMP6_PARAMPROB_NEXTHEADER:
    469 			code = PRC_UNREACH_PROTOCOL;
    470 			break;
    471 		case ICMP6_PARAMPROB_HEADER:
    472 		case ICMP6_PARAMPROB_OPTION:
    473 			code = PRC_PARAMPROB;
    474 			break;
    475 		default:
    476 			goto badcode;
    477 		}
    478 		goto deliver;
    479 		break;
    480 
    481 	case ICMP6_ECHO_REQUEST:
    482 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echo);
    483 		if (code != 0)
    484 			goto badcode;
    485 		if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
    486 			/* Give up remote */
    487 			break;
    488 		}
    489 		if ((n->m_flags & M_EXT) != 0
    490 		 || n->m_len < off + sizeof(struct icmp6_hdr)) {
    491 			struct mbuf *n0 = n;
    492 			const int maxlen = sizeof(*nip6) + sizeof(*nicmp6);
    493 
    494 			/*
    495 			 * Prepare an internal mbuf. m_pullup() doesn't
    496 			 * always copy the length we specified.
    497 			 */
    498 			if (maxlen >= MCLBYTES) {
    499 #ifdef DIAGNOSTIC
    500 				printf("MCLBYTES too small\n");
    501 #endif
    502 				/* Give up remote */
    503 				m_freem(n0);
    504 				break;
    505 			}
    506 			MGETHDR(n, M_DONTWAIT, n0->m_type);
    507 			if (n && maxlen >= MHLEN) {
    508 				MCLGET(n, M_DONTWAIT);
    509 				if ((n->m_flags & M_EXT) == 0) {
    510 					m_free(n);
    511 					n = NULL;
    512 				}
    513 			}
    514 			if (n == NULL) {
    515 				/* Give up remote */
    516 				m_freem(n0);
    517 				break;
    518 			}
    519 			M_COPY_PKTHDR(n, n0);
    520 			/*
    521 			 * Copy IPv6 and ICMPv6 only.
    522 			 */
    523 			nip6 = mtod(n, struct ip6_hdr *);
    524 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
    525 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
    526 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
    527 			noff = sizeof(struct ip6_hdr);
    528 			n->m_pkthdr.len = n->m_len =
    529 				noff + sizeof(struct icmp6_hdr);
    530 			/*
    531 			 * Adjust mbuf. ip6_plen will be adjusted in
    532 			 * ip6_output().
    533 			 */
    534 			m_adj(n0, off + sizeof(struct icmp6_hdr));
    535 			n->m_pkthdr.len += n0->m_pkthdr.len;
    536 			n->m_next = n0;
    537 			n0->m_flags &= ~M_PKTHDR;
    538 		} else {
    539 			nip6 = mtod(n, struct ip6_hdr *);
    540 			nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
    541 			noff = off;
    542 		}
    543 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
    544 		nicmp6->icmp6_code = 0;
    545 		if (n) {
    546 			icmp6stat.icp6s_reflect++;
    547 			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
    548 			icmp6_reflect(n, noff);
    549 		}
    550 		break;
    551 
    552 	case ICMP6_ECHO_REPLY:
    553 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_echoreply);
    554 		if (code != 0)
    555 			goto badcode;
    556 		break;
    557 
    558 	case MLD6_LISTENER_QUERY:
    559 	case MLD6_LISTENER_REPORT:
    560 		if (icmp6len < sizeof(struct mld6_hdr))
    561 			goto badlen;
    562 		if (icmp6->icmp6_type == MLD6_LISTENER_QUERY) /* XXX: ugly... */
    563 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldquery);
    564 		else
    565 			icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mldreport);
    566 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    567 			/* give up local */
    568 			mld6_input(m, off);
    569 			m = NULL;
    570 			goto freeit;
    571 		}
    572 		mld6_input(n, off);
    573 		/* m stays. */
    574 		break;
    575 
    576 	case MLD6_LISTENER_DONE:
    577 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mlddone);
    578 		if (icmp6len < sizeof(struct mld6_hdr))	/* necessary? */
    579 			goto badlen;
    580 		break;		/* nothing to be done in kernel */
    581 
    582 	case MLD6_MTRACE_RESP:
    583 	case MLD6_MTRACE:
    584 		/* XXX: these two are experimental. not officially defind. */
    585 		/* XXX: per-interface statistics? */
    586 		break;		/* just pass it to applications */
    587 
    588 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
    589 	    {
    590 		enum { WRU, FQDN } mode;
    591 
    592 		if (code != 0)
    593 			goto badcode;
    594 		if (!icmp6_nodeinfo)
    595 			break;
    596 
    597 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
    598 			mode = WRU;
    599 		else if (icmp6len >= sizeof(struct icmp6_hdr) + 8) /* XXX */
    600 			mode = FQDN;
    601 		else
    602 			goto badlen;
    603 
    604 		if (mode == FQDN) {
    605 #ifndef PULLDOWN_TEST
    606 			IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
    607 					 IPPROTO_DONE);
    608 #endif
    609 			n = m_copy(m, 0, M_COPYALL);
    610 			if (n)
    611 				n = ni6_input(n, off);
    612 			if (n)
    613 				noff = sizeof(struct ip6_hdr);
    614 		} else {
    615 			u_char *p;
    616 			int maxlen, maxhlen;
    617 
    618 			maxlen = sizeof(*nip6) + sizeof(*nicmp6) + 4;
    619 			if (maxlen >= MCLBYTES) {
    620 #ifdef DIAGNOSTIC
    621 				printf("MCLBYTES too small\n");
    622 #endif
    623 				/* Give up remote */
    624 				break;
    625 			}
    626 			MGETHDR(n, M_DONTWAIT, m->m_type);
    627 			if (n && maxlen > MHLEN) {
    628 				MCLGET(n, M_DONTWAIT);
    629 				if ((n->m_flags & M_EXT) == 0) {
    630 					m_free(n);
    631 					n = NULL;
    632 				}
    633 			}
    634 			if (n == NULL) {
    635 				/* Give up remote */
    636 				break;
    637 			}
    638 			n->m_len = 0;
    639 			maxhlen = M_TRAILINGSPACE(n) - maxlen;
    640 			if (maxhlen > hostnamelen)
    641 				maxhlen = hostnamelen;
    642 			/*
    643 			 * Copy IPv6 and ICMPv6 only.
    644 			 */
    645 			nip6 = mtod(n, struct ip6_hdr *);
    646 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
    647 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
    648 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
    649 			p = (u_char *)(nicmp6 + 1);
    650 			bzero(p, 4);
    651 			bcopy(hostname, p + 4, maxhlen);
    652 			noff = sizeof(struct ip6_hdr);
    653 			M_COPY_PKTHDR(n, m); /* just for recvif */
    654 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
    655 				sizeof(struct icmp6_hdr) + 4 + maxhlen;
    656 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
    657 			nicmp6->icmp6_code = 0;
    658 		}
    659 #undef hostnamelen
    660 		if (n) {
    661 			icmp6stat.icp6s_reflect++;
    662 			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
    663 			icmp6_reflect(n, noff);
    664 		}
    665 		break;
    666 	    }
    667 
    668 	case ICMP6_WRUREPLY:
    669 		if (code != 0)
    670 			goto badcode;
    671 		break;
    672 
    673 	case ND_ROUTER_SOLICIT:
    674 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routersolicit);
    675 		if (code != 0)
    676 			goto badcode;
    677 		if (icmp6len < sizeof(struct nd_router_solicit))
    678 			goto badlen;
    679 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    680 			/* give up local */
    681 			nd6_rs_input(m, off, icmp6len);
    682 			m = NULL;
    683 			goto freeit;
    684 		}
    685 		nd6_rs_input(n, off, icmp6len);
    686 		/* m stays. */
    687 		break;
    688 
    689 	case ND_ROUTER_ADVERT:
    690 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_routeradvert);
    691 		if (code != 0)
    692 			goto badcode;
    693 		if (icmp6len < sizeof(struct nd_router_advert))
    694 			goto badlen;
    695 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    696 			/* give up local */
    697 			nd6_ra_input(m, off, icmp6len);
    698 			m = NULL;
    699 			goto freeit;
    700 		}
    701 		nd6_ra_input(n, off, icmp6len);
    702 		/* m stays. */
    703 		break;
    704 
    705 	case ND_NEIGHBOR_SOLICIT:
    706 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighborsolicit);
    707 		if (code != 0)
    708 			goto badcode;
    709 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
    710 			goto badlen;
    711 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    712 			/* give up local */
    713 			nd6_ns_input(m, off, icmp6len);
    714 			m = NULL;
    715 			goto freeit;
    716 		}
    717 		nd6_ns_input(n, off, icmp6len);
    718 		/* m stays. */
    719 		break;
    720 
    721 	case ND_NEIGHBOR_ADVERT:
    722 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_neighboradvert);
    723 		if (code != 0)
    724 			goto badcode;
    725 		if (icmp6len < sizeof(struct nd_neighbor_advert))
    726 			goto badlen;
    727 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    728 			/* give up local */
    729 			nd6_na_input(m, off, icmp6len);
    730 			m = NULL;
    731 			goto freeit;
    732 		}
    733 		nd6_na_input(n, off, icmp6len);
    734 		/* m stays. */
    735 		break;
    736 
    737 	case ND_REDIRECT:
    738 		icmp6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_redirect);
    739 		if (code != 0)
    740 			goto badcode;
    741 		if (icmp6len < sizeof(struct nd_redirect))
    742 			goto badlen;
    743 		if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
    744 			/* give up local */
    745 			icmp6_redirect_input(m, off);
    746 			m = NULL;
    747 			goto freeit;
    748 		}
    749 		icmp6_redirect_input(n, off);
    750 		/* m stays. */
    751 		break;
    752 
    753 	case ICMP6_ROUTER_RENUMBERING:
    754 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
    755 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
    756 			goto badcode;
    757 		if (icmp6len < sizeof(struct icmp6_router_renum))
    758 			goto badlen;
    759 		break;
    760 
    761 	default:
    762 		printf("icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
    763 		       icmp6->icmp6_type, ip6_sprintf(&ip6->ip6_src),
    764 		       ip6_sprintf(&ip6->ip6_dst),
    765 		       m->m_pkthdr.rcvif ? m->m_pkthdr.rcvif->if_index : 0);
    766 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
    767 			/* ICMPv6 error: MUST deliver it by spec... */
    768 			code = PRC_NCMDS;
    769 			/* deliver */
    770 		} else {
    771 			/* ICMPv6 informational: MUST not deliver */
    772 			break;
    773 		}
    774 	deliver:
    775 		if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
    776 			icmp6stat.icp6s_tooshort++;
    777 			goto freeit;
    778 		}
    779 #ifndef PULLDOWN_TEST
    780 		IP6_EXTHDR_CHECK(m, off,
    781 			sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
    782 			IPPROTO_DONE);
    783 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
    784 #else
    785 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
    786 			sizeof(*icmp6) + sizeof(struct ip6_hdr));
    787 		if (icmp6 == NULL) {
    788 			icmp6stat.icp6s_tooshort++;
    789 			return IPPROTO_DONE;
    790 		}
    791 #endif
    792 		bzero(&icmp6src, sizeof(icmp6src));
    793 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
    794 		icmp6src.sin6_family = AF_INET6;
    795 		icmp6src.sin6_addr = ((struct ip6_hdr *)(icmp6 + 1))->ip6_dst;
    796 
    797 		/* Detect the upper level protocol */
    798 	    {
    799 		void (*ctlfunc) __P((int, struct sockaddr *, void *));
    800 		struct ip6_hdr *eip6 = (struct ip6_hdr *)(icmp6 + 1);
    801 		u_int8_t nxt = eip6->ip6_nxt;
    802 		int eoff = off + sizeof(struct icmp6_hdr) +
    803 			sizeof(struct ip6_hdr);
    804 		struct ip6ctlparam ip6cp;
    805 		struct in6_addr *finaldst = NULL;
    806 		int icmp6type = icmp6->icmp6_type;
    807 		struct ip6_frag *fh;
    808 		struct ip6_rthdr *rth;
    809 		struct ip6_rthdr0 *rth0;
    810 		int rthlen;
    811 
    812 		while (1) { /* XXX: should avoid inf. loop explicitly? */
    813 			struct ip6_ext *eh;
    814 
    815 			switch(nxt) {
    816 			case IPPROTO_HOPOPTS:
    817 			case IPPROTO_DSTOPTS:
    818 			case IPPROTO_AH:
    819 #ifndef PULLDOWN_TEST
    820 				IP6_EXTHDR_CHECK(m, 0, eoff +
    821 						 sizeof(struct ip6_ext),
    822 						 IPPROTO_DONE);
    823 				eh = (struct ip6_ext *)(mtod(m, caddr_t)
    824 							+ eoff);
    825 #else
    826 				IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
    827 					eoff, sizeof(*eh));
    828 				if (eh == NULL) {
    829 					icmp6stat.icp6s_tooshort++;
    830 					return IPPROTO_DONE;
    831 				}
    832 #endif
    833 
    834 				if (nxt == IPPROTO_AH)
    835 					eoff += (eh->ip6e_len + 2) << 2;
    836 				else
    837 					eoff += (eh->ip6e_len + 1) << 3;
    838 				nxt = eh->ip6e_nxt;
    839 				break;
    840 			case IPPROTO_ROUTING:
    841 				/*
    842 				 * When the erroneous packet contains a
    843 				 * routing header, we should examine the
    844 				 * header to determine the final destination.
    845 				 * Otherwise, we can't properly update
    846 				 * information that depends on the final
    847 				 * destination (e.g. path MTU).
    848 				 */
    849 #ifndef PULLDOWN_TEST
    850 				IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth),
    851 						 IPPROTO_DONE);
    852 				rth = (struct ip6_rthdr *)(mtod(m, caddr_t)
    853 							   + eoff);
    854 #else
    855 				IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
    856 					eoff, sizeof(*rth));
    857 				if (rth == NULL) {
    858 					icmp6stat.icp6s_tooshort++;
    859 					return IPPROTO_DONE;
    860 				}
    861 #endif
    862 				rthlen = (rth->ip6r_len + 1) << 3;
    863 				/*
    864 				 * XXX: currently there is no
    865 				 * officially defined type other
    866 				 * than type-0.
    867 				 * Note that if the segment left field
    868 				 * is 0, all intermediate hops must
    869 				 * have been passed.
    870 				 */
    871 				if (rth->ip6r_segleft &&
    872 				    rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
    873 					int hops;
    874 
    875 #ifndef PULLDOWN_TEST
    876 					IP6_EXTHDR_CHECK(m, 0, eoff + rthlen,
    877 							 IPPROTO_DONE);
    878 					rth0 = (struct ip6_rthdr0 *)(mtod(m, caddr_t) + eoff);
    879 #else
    880 					IP6_EXTHDR_GET(rth0,
    881 						       struct ip6_rthdr0 *, m,
    882 						       eoff, rthlen);
    883 					if (rth0 == NULL) {
    884 						icmp6stat.icp6s_tooshort++;
    885 						return IPPROTO_DONE;
    886 					}
    887 #endif
    888 					/* just ignore a bogus header */
    889 					if ((rth0->ip6r0_len % 2) == 0 &&
    890 					    (hops = rth0->ip6r0_len/2))
    891 						finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
    892 				}
    893 				eoff += rthlen;
    894 				nxt = rth->ip6r_nxt;
    895 				break;
    896 			case IPPROTO_FRAGMENT:
    897 #ifndef PULLDOWN_TEST
    898 				IP6_EXTHDR_CHECK(m, 0, eoff +
    899 						 sizeof(struct ip6_frag),
    900 						 IPPROTO_DONE);
    901 				fh = (struct ip6_frag *)(mtod(m, caddr_t)
    902 							 + eoff);
    903 #else
    904 				IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
    905 					eoff, sizeof(*fh));
    906 				if (fh == NULL) {
    907 					icmp6stat.icp6s_tooshort++;
    908 					return IPPROTO_DONE;
    909 				}
    910 #endif
    911 				/*
    912 				 * Data after a fragment header is meaningless
    913 				 * unless it is the first fragment, but
    914 				 * we'll go to the notify label for path MTU
    915 				 * discovery.
    916 				 */
    917 				if (fh->ip6f_offlg & IP6F_OFF_MASK)
    918 					goto notify;
    919 
    920 				eoff += sizeof(struct ip6_frag);
    921 				nxt = fh->ip6f_nxt;
    922 				break;
    923 			default:
    924 				/*
    925 				 * This case includes ESP and the No Next
    926 				 * Header. In such cases going to the notify
    927 				 * label does not have any meaning
    928 				 * (i.e. ctlfunc will be NULL), but we go
    929 				 * anyway since we might have to update
    930 				 * path MTU information.
    931 				 */
    932 				goto notify;
    933 			}
    934 		}
    935 	    notify:
    936 #ifndef PULLDOWN_TEST
    937 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
    938 #else
    939 		IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
    940 			sizeof(*icmp6) + sizeof(struct ip6_hdr));
    941 		if (icmp6 == NULL) {
    942 			icmp6stat.icp6s_tooshort++;
    943 			return IPPROTO_DONE;
    944 		}
    945 #endif
    946 		if (icmp6type == ICMP6_PACKET_TOO_BIG) {
    947 			if (finaldst == NULL)
    948 				finaldst = &((struct ip6_hdr *)(icmp6 + 1))->ip6_dst;
    949 			icmp6_mtudisc_update(finaldst, icmp6, m);
    950 		}
    951 
    952 		ctlfunc = (void (*) __P((int, struct sockaddr *, void *)))
    953 			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
    954 		if (ctlfunc) {
    955 			ip6cp.ip6c_m = m;
    956 			ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
    957 			ip6cp.ip6c_off = eoff;
    958 			(*ctlfunc)(code, (struct sockaddr *)&icmp6src, &ip6cp);
    959 		}
    960 	    }
    961 		break;
    962 
    963 	badcode:
    964 		icmp6stat.icp6s_badcode++;
    965 		break;
    966 
    967 	badlen:
    968 		icmp6stat.icp6s_badlen++;
    969 		break;
    970 	}
    971 
    972 	icmp6_rip6_input(&m, *offp);
    973 	return IPPROTO_DONE;
    974 
    975  freeit:
    976 	m_freem(m);
    977 	return IPPROTO_DONE;
    978 }
    979 
    980 static void
    981 icmp6_mtudisc_update(dst, icmp6, m)
    982 	struct in6_addr *dst;
    983 	struct icmp6_hdr *icmp6;/* we can assume the validity of the pointer */
    984 	struct mbuf *m;	/* currently unused but added for scoped addrs */
    985 {
    986 	u_int mtu = ntohl(icmp6->icmp6_mtu);
    987 	struct rtentry *rt = NULL;
    988 	struct sockaddr_in6 sin6;
    989 
    990 	bzero(&sin6, sizeof(sin6));
    991 	sin6.sin6_family = PF_INET6;
    992 	sin6.sin6_len = sizeof(struct sockaddr_in6);
    993 	sin6.sin6_addr = *dst;
    994 	/* sin6.sin6_scope_id = XXX: should be set if DST is a scoped addr */
    995 	rt = rtalloc1((struct sockaddr *)&sin6, 1);	/*clone*/
    996 	if (!rt || (rt->rt_flags & RTF_HOST) == 0) {
    997 		if (rt)
    998 			RTFREE(rt);
    999 		rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
   1000 	}
   1001 
   1002 	if (rt && (rt->rt_flags & RTF_HOST)
   1003 	    && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
   1004 		if (mtu < IPV6_MMTU) {
   1005 				/* xxx */
   1006 			rt->rt_rmx.rmx_locks |= RTV_MTU;
   1007 		} else if (mtu < rt->rt_ifp->if_mtu &&
   1008 			   rt->rt_rmx.rmx_mtu > mtu) {
   1009 			rt->rt_rmx.rmx_mtu = mtu;
   1010 		}
   1011 	}
   1012 	if (rt)
   1013 		RTFREE(rt);
   1014 }
   1015 
   1016 /*
   1017  * Process a Node Information Query
   1018  */
   1019 #ifndef offsetof		/* XXX */
   1020 #define	offsetof(type, member)	((size_t)(&((type *)0)->member))
   1021 #endif
   1022 
   1023 static struct mbuf *
   1024 ni6_input(m, off)
   1025 	struct mbuf *m;
   1026 	int off;
   1027 {
   1028 	struct icmp6_nodeinfo *ni6, *nni6;
   1029 	struct mbuf *n = NULL;
   1030 	u_int16_t qtype;
   1031 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
   1032 	struct ni_reply_fqdn *fqdn;
   1033 	int addrs;		/* for NI_QTYPE_NODEADDR */
   1034 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
   1035 
   1036 #ifndef PULLDOWN_TEST
   1037 	ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
   1038 #else
   1039 	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo *, m, off, sizeof(*ni6));
   1040 	if (ni6 == NULL) {
   1041 		/* m is already reclaimed */
   1042 		return NULL;
   1043 	}
   1044 #endif
   1045 	qtype = ntohs(ni6->ni_qtype);
   1046 
   1047 	switch(qtype) {
   1048 	 case NI_QTYPE_NOOP:
   1049 		 break;		/* no reply data */
   1050 	 case NI_QTYPE_SUPTYPES:
   1051 		 goto bad;	/* xxx: to be implemented */
   1052 		 break;
   1053 	 case NI_QTYPE_FQDN:
   1054 		 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_name) +
   1055 			 hostnamelen;
   1056 		 break;
   1057 	 case NI_QTYPE_NODEADDR:
   1058 		 addrs = ni6_addrs(ni6, m, &ifp);
   1059 		 if ((replylen += addrs * sizeof(struct in6_addr)) > MCLBYTES)
   1060 			 replylen = MCLBYTES; /* XXX: we'll truncate later */
   1061 
   1062 		 break;
   1063 	 default:
   1064 		 /*
   1065 		  * XXX: We must return a reply with the ICMP6 code
   1066 		  * `unknown Qtype' in this case. However we regard the case
   1067 		  * as an FQDN query for backward compatibility.
   1068 		  * Older versions set a random value to this field,
   1069 		  * so it rarely varies in the defined qtypes.
   1070 		  * But the mechanism is not reliable...
   1071 		  * maybe we should obsolete older versions.
   1072 		  */
   1073 		 qtype = NI_QTYPE_FQDN;
   1074 		 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_name) +
   1075 			 hostnamelen;
   1076 		 break;
   1077 	}
   1078 
   1079 	/* allocate a mbuf to reply. */
   1080 	MGETHDR(n, M_DONTWAIT, m->m_type);
   1081 	if (n == NULL) {
   1082 		m_freem(m);
   1083 		return(NULL);
   1084 	}
   1085 	M_COPY_PKTHDR(n, m); /* just for recvif */
   1086 	if (replylen > MHLEN) {
   1087 		if (replylen > MCLBYTES)
   1088 			 /*
   1089 			  * XXX: should we try to allocate more? But MCLBYTES is
   1090 			  * probably much larger than IPV6_MMTU...
   1091 			  */
   1092 			goto bad;
   1093 		MCLGET(n, M_DONTWAIT);
   1094 		if ((n->m_flags & M_EXT) == 0) {
   1095 			goto bad;
   1096 		}
   1097 	}
   1098 	n->m_pkthdr.len = n->m_len = replylen;
   1099 
   1100 	/* copy mbuf header and IPv6 + Node Information base headers */
   1101 	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
   1102 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
   1103 	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
   1104 
   1105 	/* qtype dependent procedure */
   1106 	switch (qtype) {
   1107 	 case NI_QTYPE_NOOP:
   1108 		 nni6->ni_flags = 0;
   1109 		 break;
   1110 	 case NI_QTYPE_SUPTYPES:
   1111 		 goto bad;	/* xxx: to be implemented */
   1112 		 break;
   1113 	 case NI_QTYPE_FQDN:
   1114 		 if (hostnamelen > 255) { /* XXX: rare case, but may happen */
   1115 			 printf("ni6_input: "
   1116 				"hostname length(%d) is too large for reply\n",
   1117 				hostnamelen);
   1118 			 goto bad;
   1119 		 }
   1120 		 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
   1121 						 sizeof(struct ip6_hdr) +
   1122 						 sizeof(struct icmp6_nodeinfo));
   1123 		 nni6->ni_flags = 0; /* XXX: meaningless TTL */
   1124 		 fqdn->ni_fqdn_ttl = 0;	/* ditto. */
   1125 		 fqdn->ni_fqdn_namelen = hostnamelen;
   1126 		 bcopy(hostname, &fqdn->ni_fqdn_name[0], hostnamelen);
   1127 		 break;
   1128 	 case NI_QTYPE_NODEADDR:
   1129 	 {
   1130 		 int lenlim, copied;
   1131 
   1132 		 if (n->m_flags & M_EXT)
   1133 			 lenlim = MCLBYTES - sizeof(struct ip6_hdr) -
   1134 				 sizeof(struct icmp6_nodeinfo);
   1135 		 else
   1136 			 lenlim = MHLEN - sizeof(struct ip6_hdr) -
   1137 				 sizeof(struct icmp6_nodeinfo);
   1138 		 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
   1139 		 /* XXX: reset mbuf length */
   1140 		 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
   1141 			 sizeof(struct icmp6_nodeinfo) + copied;
   1142 		 break;
   1143 	 }
   1144 	 default:
   1145 		 break;		/* XXX impossible! */
   1146 	}
   1147 
   1148 	nni6->ni_type = ICMP6_NI_REPLY;
   1149 	nni6->ni_code = ICMP6_NI_SUCESS;
   1150 	m_freem(m);
   1151 	return(n);
   1152 
   1153   bad:
   1154 	m_freem(m);
   1155 	if (n)
   1156 		m_freem(n);
   1157 	return(NULL);
   1158 }
   1159 #undef hostnamelen
   1160 
   1161 /*
   1162  * calculate the number of addresses to be returned in the node info reply.
   1163  */
   1164 static int
   1165 ni6_addrs(ni6, m, ifpp)
   1166 	struct icmp6_nodeinfo *ni6;
   1167 	struct mbuf *m;
   1168 	struct ifnet **ifpp;
   1169 {
   1170 	register struct ifnet *ifp;
   1171 	register struct in6_ifaddr *ifa6;
   1172 	register struct ifaddr *ifa;
   1173 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   1174 	int addrs = 0, addrsofif, iffound = 0;
   1175 
   1176 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
   1177 	{
   1178 		addrsofif = 0;
   1179 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
   1180 		     ifa = ifa->ifa_list.tqe_next)
   1181 		{
   1182 			if (ifa->ifa_addr->sa_family != AF_INET6)
   1183 				continue;
   1184 			ifa6 = (struct in6_ifaddr *)ifa;
   1185 
   1186 			if (!(ni6->ni_flags & NI_NODEADDR_FLAG_ALL) &&
   1187 			    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
   1188 					       &ifa6->ia_addr.sin6_addr))
   1189 				iffound = 1;
   1190 
   1191 			/*
   1192 			 * IPv4-mapped addresses can only be returned by a
   1193 			 * Node Information proxy, since they represent
   1194 			 * addresses of IPv4-only nodes, which perforce do
   1195 			 * not implement this protocol.
   1196 			 * [icmp-name-lookups-05]
   1197 			 * So we don't support NI_NODEADDR_FLAG_COMPAT in
   1198 			 * this function at this moment.
   1199 			 */
   1200 
   1201 			if (ifa6->ia6_flags & IN6_IFF_ANYCAST)
   1202 				continue; /* we need only unicast addresses */
   1203 
   1204 			if ((ni6->ni_flags & (NI_NODEADDR_FLAG_LINKLOCAL |
   1205 					      NI_NODEADDR_FLAG_SITELOCAL |
   1206 					      NI_NODEADDR_FLAG_GLOBAL)) == 0)
   1207 				continue;
   1208 
   1209 			/* What do we have to do about ::1? */
   1210 			switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
   1211 			 case IPV6_ADDR_SCOPE_LINKLOCAL:
   1212 				if (ni6->ni_flags & NI_NODEADDR_FLAG_LINKLOCAL)
   1213 					addrsofif++;
   1214 				break;
   1215 			 case IPV6_ADDR_SCOPE_SITELOCAL:
   1216 				if (ni6->ni_flags & NI_NODEADDR_FLAG_SITELOCAL)
   1217 					addrsofif++;
   1218 				break;
   1219 			 case IPV6_ADDR_SCOPE_GLOBAL:
   1220 				 if (ni6->ni_flags & NI_NODEADDR_FLAG_GLOBAL)
   1221 					 addrsofif++;
   1222 				 break;
   1223 			 default:
   1224 				 continue;
   1225 			}
   1226 		}
   1227 		if (iffound) {
   1228 			*ifpp = ifp;
   1229 			return(addrsofif);
   1230 		}
   1231 
   1232 		addrs += addrsofif;
   1233 	}
   1234 
   1235 	return(addrs);
   1236 }
   1237 
   1238 static int
   1239 ni6_store_addrs(ni6, nni6, ifp0, resid)
   1240 	struct icmp6_nodeinfo *ni6, *nni6;
   1241 	struct ifnet *ifp0;
   1242 	int resid;
   1243 {
   1244 	register struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
   1245 	register struct in6_ifaddr *ifa6;
   1246 	register struct ifaddr *ifa;
   1247 	int docopy, copied = 0;
   1248 	u_char *cp = (u_char *)(nni6 + 1);
   1249 
   1250 	if (ifp0 == NULL && !(ni6->ni_flags & NI_NODEADDR_FLAG_ALL))
   1251 		return(0);	/* needless to copy */
   1252 
   1253 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
   1254 	{
   1255 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
   1256 		     ifa = ifa->ifa_list.tqe_next)
   1257 		{
   1258 			docopy = 0;
   1259 
   1260 			if (ifa->ifa_addr->sa_family != AF_INET6)
   1261 				continue;
   1262 			ifa6 = (struct in6_ifaddr *)ifa;
   1263 
   1264 			if (ifa6->ia6_flags & IN6_IFF_ANYCAST) {
   1265 				/* just experimental. not in the spec. */
   1266 				if (ni6->ni_flags & NI_NODEADDR_FLAG_ANYCAST)
   1267 					docopy = 1;
   1268 				else
   1269 					continue;
   1270 			}
   1271 			else {	/* unicast address */
   1272 				if (ni6->ni_flags & NI_NODEADDR_FLAG_ANYCAST)
   1273 					continue;
   1274 				else
   1275 					docopy = 1;
   1276 			}
   1277 
   1278 			/* What do we have to do about ::1? */
   1279 			switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
   1280 			 case IPV6_ADDR_SCOPE_LINKLOCAL:
   1281 				if (ni6->ni_flags & NI_NODEADDR_FLAG_LINKLOCAL)
   1282 					docopy = 1;
   1283 				break;
   1284 			 case IPV6_ADDR_SCOPE_SITELOCAL:
   1285 				if (ni6->ni_flags & NI_NODEADDR_FLAG_SITELOCAL)
   1286 					docopy = 1;
   1287 				break;
   1288 			 case IPV6_ADDR_SCOPE_GLOBAL:
   1289 				 if (ni6->ni_flags & NI_NODEADDR_FLAG_GLOBAL)
   1290 					 docopy = 1;
   1291 				 break;
   1292 			 default:
   1293 				 continue;
   1294 			}
   1295 
   1296 			if (docopy) {
   1297 				if (resid < sizeof(struct in6_addr)) {
   1298 					/*
   1299 					 * We give up much more copy.
   1300 					 * Set the truncate flag and return.
   1301 					 */
   1302 					nni6->ni_flags |=
   1303 						NI_NODEADDR_FLAG_TRUNCATE;
   1304 					return(copied);
   1305 				}
   1306 				bcopy(&ifa6->ia_addr.sin6_addr, cp,
   1307 				      sizeof(struct in6_addr));
   1308 				/* XXX: KAME link-local hack; remove ifindex */
   1309 				if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
   1310 					((struct in6_addr *)cp)->s6_addr16[1] = 0;
   1311 				cp += sizeof(struct in6_addr);
   1312 				resid -= sizeof(struct in6_addr);
   1313 				copied += sizeof(struct in6_addr);
   1314 			}
   1315 		}
   1316 		if (ifp0)	/* we need search only on the specified IF */
   1317 			break;
   1318 	}
   1319 
   1320 	return(copied);
   1321 }
   1322 
   1323 /*
   1324  * XXX almost dup'ed code with rip6_input.
   1325  */
   1326 static int
   1327 icmp6_rip6_input(mp, off)
   1328 	struct	mbuf **mp;
   1329 	int	off;
   1330 {
   1331 	struct mbuf *m = *mp;
   1332 	register struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   1333 	register struct in6pcb *in6p;
   1334 	struct in6pcb *last = NULL;
   1335 	struct sockaddr_in6 rip6src;
   1336 	struct icmp6_hdr *icmp6;
   1337 	struct mbuf *opts = NULL;
   1338 
   1339 #ifndef PULLDOWN_TEST
   1340 	/* this is assumed to be safe. */
   1341 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
   1342 #else
   1343 	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off, sizeof(*icmp6));
   1344 	if (icmp6 == NULL) {
   1345 		/* m is already reclaimed */
   1346 		return IPPROTO_DONE;
   1347 	}
   1348 #endif
   1349 
   1350 	bzero(&rip6src, sizeof(rip6src));
   1351 	rip6src.sin6_len = sizeof(struct sockaddr_in6);
   1352 	rip6src.sin6_family = AF_INET6;
   1353 	rip6src.sin6_addr = ip6->ip6_src;
   1354 	if (IN6_IS_SCOPE_LINKLOCAL(&rip6src.sin6_addr))
   1355 		rip6src.sin6_addr.s6_addr16[1] = 0;
   1356 	if (m->m_pkthdr.rcvif) {
   1357 		if (IN6_IS_SCOPE_LINKLOCAL(&rip6src.sin6_addr))
   1358 			rip6src.sin6_scope_id = m->m_pkthdr.rcvif->if_index;
   1359 		else
   1360 			rip6src.sin6_scope_id = 0;
   1361 	} else
   1362 		rip6src.sin6_scope_id = 0;
   1363 
   1364 	for (in6p = rawin6pcb.in6p_next;
   1365 	     in6p != &rawin6pcb; in6p = in6p->in6p_next)
   1366 	{
   1367 		if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
   1368 			continue;
   1369 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
   1370 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
   1371 			continue;
   1372 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
   1373 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
   1374 			continue;
   1375 		if (in6p->in6p_icmp6filt
   1376 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
   1377 				 in6p->in6p_icmp6filt))
   1378 			continue;
   1379 		if (last) {
   1380 			struct	mbuf *n;
   1381 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
   1382 				if (last->in6p_flags & IN6P_CONTROLOPTS)
   1383 					ip6_savecontrol(last, &opts, ip6, n);
   1384 				/* strip intermediate headers */
   1385 				m_adj(n, off);
   1386 				if (sbappendaddr(&last->in6p_socket->so_rcv,
   1387 						 (struct sockaddr *)&rip6src,
   1388 						 n, opts) == 0) {
   1389 					/* should notify about lost packet */
   1390 					m_freem(n);
   1391 					if (opts)
   1392 						m_freem(opts);
   1393 				} else
   1394 					sorwakeup(last->in6p_socket);
   1395 				opts = NULL;
   1396 			}
   1397 		}
   1398 		last = in6p;
   1399 	}
   1400 	if (last) {
   1401 		if (last->in6p_flags & IN6P_CONTROLOPTS)
   1402 			ip6_savecontrol(last, &opts, ip6, m);
   1403 		/* strip intermediate headers */
   1404 		m_adj(m, off);
   1405 		if (sbappendaddr(&last->in6p_socket->so_rcv,
   1406 				(struct sockaddr *)&rip6src, m, opts) == 0) {
   1407 			m_freem(m);
   1408 			if (opts)
   1409 				m_freem(opts);
   1410 		} else
   1411 			sorwakeup(last->in6p_socket);
   1412 	} else {
   1413 		m_freem(m);
   1414 		ip6stat.ip6s_delivered--;
   1415 	}
   1416 	return IPPROTO_DONE;
   1417 }
   1418 
   1419 /*
   1420  * Reflect the ip6 packet back to the source.
   1421  * OFF points to the icmp6 header, counted from the top of the mbuf.
   1422  */
   1423 void
   1424 icmp6_reflect(m, off)
   1425 	struct	mbuf *m;
   1426 	size_t off;
   1427 {
   1428 	struct ip6_hdr *ip6;
   1429 	struct icmp6_hdr *icmp6;
   1430 	struct in6_ifaddr *ia;
   1431 	struct in6_addr t, *src = 0;
   1432 	int plen;
   1433 	int type, code;
   1434 	struct ifnet *outif = NULL;
   1435 #ifdef COMPAT_RFC1885
   1436 	int mtu = IPV6_MMTU;
   1437 	struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
   1438 #endif
   1439 
   1440 	/* too short to reflect */
   1441 	if (off < sizeof(struct ip6_hdr)) {
   1442 		printf("sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
   1443 		       (u_long)off, (u_long)sizeof(struct ip6_hdr),
   1444 		       __FILE__, __LINE__);
   1445 		goto bad;
   1446 	}
   1447 
   1448 	/*
   1449 	 * If there are extra headers between IPv6 and ICMPv6, strip
   1450 	 * off that header first.
   1451 	 */
   1452 	if (off > sizeof(struct ip6_hdr)) {
   1453 		size_t l;
   1454 		struct ip6_hdr nip6;
   1455 
   1456 		l = off - sizeof(struct ip6_hdr);
   1457 		m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
   1458 		m_adj(m, l);
   1459 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
   1460 		if (m->m_len < l) {
   1461 			if ((m = m_pullup(m, l)) == NULL)
   1462 				return;
   1463 		}
   1464 		bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
   1465 	} else /* off == sizeof(struct ip6_hdr) */ {
   1466 		size_t l;
   1467 		l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
   1468 		if (m->m_len < l) {
   1469 			if ((m = m_pullup(m, l)) == NULL)
   1470 				return;
   1471 		}
   1472 	}
   1473 	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
   1474 	ip6 = mtod(m, struct ip6_hdr *);
   1475 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   1476 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
   1477 	type = icmp6->icmp6_type; /* keep type for statistics */
   1478 	code = icmp6->icmp6_code; /* ditto. */
   1479 
   1480 	t = ip6->ip6_dst;
   1481 	/*
   1482 	 * ip6_input() drops a packet if its src is multicast.
   1483 	 * So, the src is never multicast.
   1484 	 */
   1485 	ip6->ip6_dst = ip6->ip6_src;
   1486 
   1487 	/* XXX hack for link-local addresses */
   1488 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
   1489 		ip6->ip6_dst.s6_addr16[1] =
   1490 			htons(m->m_pkthdr.rcvif->if_index);
   1491 	if (IN6_IS_ADDR_LINKLOCAL(&t))
   1492 		t.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
   1493 
   1494 #ifdef COMPAT_RFC1885
   1495 	/*
   1496 	 * xxx guess MTU
   1497 	 * RFC 1885 requires that echo reply should be truncated if it
   1498 	 * does not fit in with (return) path MTU, but the description was
   1499 	 * removed in the new spec.
   1500 	 */
   1501 	if (icmp6_reflect_rt.ro_rt == 0 ||
   1502 	    ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
   1503 		if (icmp6_reflect_rt.ro_rt) {
   1504 			icmp6_reflect_rt.ro_rt = 0;
   1505 		}
   1506 		bzero(sin6, sizeof(*sin6));
   1507 		sin6->sin6_family = PF_INET6;
   1508 		sin6->sin6_len = sizeof(struct sockaddr_in6);
   1509 		sin6->sin6_addr = ip6->ip6_dst;
   1510 
   1511 		rtalloc((struct route *)&icmp6_reflect_rt.ro_rt);
   1512 	}
   1513 
   1514 	if (icmp6_reflect_rt.ro_rt == 0)
   1515 		goto bad;
   1516 
   1517 	if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
   1518 	    && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
   1519 		mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
   1520 
   1521 	if (mtu < m->m_pkthdr.len) {
   1522 		plen -= (m->m_pkthdr.len - mtu);
   1523 		m_adj(m, mtu - m->m_pkthdr.len);
   1524 	}
   1525 #endif
   1526 	/*
   1527 	 * If the incoming packet was addressed directly to us(i.e. unicast),
   1528 	 * use dst as the src for the reply.
   1529 	 * The IN6_IFF_NOTREADY case would be VERY rare, but is possible when
   1530 	 * (for example) when we encounter an error while forwarding procedure
   1531 	 * destined to a duplicated address of ours.
   1532 	 */
   1533 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
   1534 		if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
   1535 		    (ia->ia6_flags & (IN6_IFF_ANYCAST|IN6_IFF_NOTREADY)) == 0) {
   1536 			src = &t;
   1537 			break;
   1538 		}
   1539 	if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
   1540 		/*
   1541 		 * This is the case if the dst is our link-local address
   1542 		 * and the sender is also ourseleves.
   1543 		 */
   1544 		src = &t;
   1545 	}
   1546 
   1547 	if (src == 0)
   1548 		/*
   1549 		 * This case matches to multicasts, our anycast, or unicasts
   1550 		 * that we do not own. Select a source address which has the
   1551 		 * same scope.
   1552 		 * XXX: for (non link-local) multicast addresses, this might
   1553 		 * not be a good choice.
   1554 		 */
   1555 		if ((ia = in6_ifawithscope(m->m_pkthdr.rcvif, &t)) != 0)
   1556 			src = &IA6_SIN6(ia)->sin6_addr;
   1557 
   1558 	if (src == 0)
   1559 		goto bad;
   1560 
   1561 	ip6->ip6_src = *src;
   1562 
   1563 	ip6->ip6_flow = 0;
   1564 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
   1565 	ip6->ip6_vfc |= IPV6_VERSION;
   1566 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   1567 	if (m->m_pkthdr.rcvif) {
   1568 		/* XXX: This may not be the outgoing interface */
   1569 		ip6->ip6_hlim = nd_ifinfo[m->m_pkthdr.rcvif->if_index].chlim;
   1570 	}
   1571 
   1572 	icmp6->icmp6_cksum = 0;
   1573 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
   1574 					sizeof(struct ip6_hdr), plen);
   1575 
   1576 	/*
   1577 	 * xxx option handling
   1578 	 */
   1579 
   1580 	m->m_flags &= ~(M_BCAST|M_MCAST);
   1581 #ifdef IPSEC
   1582 	/* Don't lookup socket */
   1583 	ipsec_setsocket(m, NULL);
   1584 #endif /*IPSEC*/
   1585 
   1586 #ifdef COMPAT_RFC1885
   1587 	ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL, &outif);
   1588 #else
   1589 	ip6_output(m, NULL, NULL, 0, NULL, &outif);
   1590 #endif
   1591 	if (outif)
   1592 		icmp6_ifoutstat_inc(outif, type, code);
   1593 
   1594 	return;
   1595 
   1596  bad:
   1597 	m_freem(m);
   1598 	return;
   1599 }
   1600 
   1601 void
   1602 icmp6_fasttimo()
   1603 {
   1604 	mld6_fasttimeo();
   1605 }
   1606 
   1607 static const char *
   1608 icmp6_redirect_diag(src6, dst6, tgt6)
   1609 	struct in6_addr *src6;
   1610 	struct in6_addr *dst6;
   1611 	struct in6_addr *tgt6;
   1612 {
   1613 	static char buf[1024];
   1614 	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
   1615 		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
   1616 	return buf;
   1617 }
   1618 
   1619 void
   1620 icmp6_redirect_input(m, off)
   1621 	register struct mbuf *m;
   1622 	int off;
   1623 {
   1624 	struct ifnet *ifp = m->m_pkthdr.rcvif;
   1625 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   1626 	struct nd_redirect *nd_rd;
   1627 	int icmp6len = ntohs(ip6->ip6_plen);
   1628 	char *lladdr = NULL;
   1629 	int lladdrlen = 0;
   1630 	u_char *redirhdr = NULL;
   1631 	int redirhdrlen = 0;
   1632 	struct rtentry *rt = NULL;
   1633 	int is_router;
   1634 	int is_onlink;
   1635 	struct in6_addr src6 = ip6->ip6_src;
   1636 	struct in6_addr redtgt6;
   1637 	struct in6_addr reddst6;
   1638 	union nd_opts ndopts;
   1639 
   1640 	if (!m || !ifp)
   1641 		return;
   1642 
   1643 	/* XXX if we are router, we don't update route by icmp6 redirect */
   1644 	if (ip6_forwarding)
   1645 		goto freeit;
   1646 	if (!icmp6_rediraccept)
   1647 		goto freeit;
   1648 
   1649 #ifndef PULLDOWN_TEST
   1650 	IP6_EXTHDR_CHECK(m, off, icmp6len,);
   1651 	nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
   1652 #else
   1653 	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
   1654 	if (nd_rd == NULL) {
   1655 		icmp6stat.icp6s_tooshort++;
   1656 		return;
   1657 	}
   1658 #endif
   1659 	redtgt6 = nd_rd->nd_rd_target;
   1660 	reddst6 = nd_rd->nd_rd_dst;
   1661 
   1662 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
   1663 		redtgt6.s6_addr16[1] = htons(ifp->if_index);
   1664 	if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
   1665 		reddst6.s6_addr16[1] = htons(ifp->if_index);
   1666 
   1667 	/* validation */
   1668 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
   1669 		log(LOG_ERR,
   1670 			"ICMP6 redirect sent from %s rejected; "
   1671 			"must be from linklocal\n", ip6_sprintf(&src6));
   1672 		goto freeit;
   1673 	}
   1674 	if (ip6->ip6_hlim != 255) {
   1675 		log(LOG_ERR,
   1676 			"ICMP6 redirect sent from %s rejected; "
   1677 			"hlim=%d (must be 255)\n",
   1678 			ip6_sprintf(&src6), ip6->ip6_hlim);
   1679 		goto freeit;
   1680 	}
   1681     {
   1682 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
   1683 	struct sockaddr_in6 sin6;
   1684 	struct in6_addr *gw6;
   1685 
   1686 	bzero(&sin6, sizeof(sin6));
   1687 	sin6.sin6_family = AF_INET6;
   1688 	sin6.sin6_len = sizeof(struct sockaddr_in6);
   1689 	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
   1690 	rt = rtalloc1((struct sockaddr *)&sin6, 0);
   1691 	if (rt) {
   1692 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
   1693 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
   1694 			log(LOG_ERR,
   1695 				"ICMP6 redirect rejected; "
   1696 				"not equal to gw-for-src=%s (must be same): "
   1697 				"%s\n",
   1698 				ip6_sprintf(gw6),
   1699 				icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
   1700 			RTFREE(rt);
   1701 			goto freeit;
   1702 		}
   1703 	} else {
   1704 		log(LOG_ERR,
   1705 			"ICMP6 redirect rejected; "
   1706 			"no route found for redirect dst: %s\n",
   1707 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
   1708 		goto freeit;
   1709 	}
   1710 	RTFREE(rt);
   1711 	rt = NULL;
   1712     }
   1713 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
   1714 		log(LOG_ERR,
   1715 			"ICMP6 redirect rejected; "
   1716 			"redirect dst must be unicast: %s\n",
   1717 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
   1718 		goto freeit;
   1719 	}
   1720 
   1721 	is_router = is_onlink = 0;
   1722 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
   1723 		is_router = 1;	/* router case */
   1724 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
   1725 		is_onlink = 1;	/* on-link destination case */
   1726 	if (!is_router && !is_onlink) {
   1727 		log(LOG_ERR,
   1728 			"ICMP6 redirect rejected; "
   1729 			"neither router case nor onlink case: %s\n",
   1730 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
   1731 		goto freeit;
   1732 	}
   1733 	/* validation passed */
   1734 
   1735 	icmp6len -= sizeof(*nd_rd);
   1736 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
   1737 	if (nd6_options(&ndopts) < 0) {
   1738 		log(LOG_INFO, "icmp6_redirect_input: "
   1739 			"invalid ND option, rejected: %s\n",
   1740 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
   1741 		goto freeit;
   1742 	}
   1743 
   1744 	if (ndopts.nd_opts_tgt_lladdr) {
   1745 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
   1746 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
   1747 	}
   1748 
   1749 	if (ndopts.nd_opts_rh) {
   1750 		redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
   1751 		redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
   1752 	}
   1753 
   1754 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
   1755 		log(LOG_INFO,
   1756 			"icmp6_redirect_input: lladdrlen mismatch for %s "
   1757 			"(if %d, icmp6 packet %d): %s\n",
   1758 			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2,
   1759 			icmp6_redirect_diag(&src6, &reddst6, &redtgt6));
   1760 	}
   1761 
   1762 	/* RFC 2461 8.3 */
   1763 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
   1764 			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
   1765 
   1766 	if (!is_onlink) {	/* better router case. perform rtredirect. */
   1767 		/* perform rtredirect */
   1768 		struct sockaddr_in6 sdst;
   1769 		struct sockaddr_in6 sgw;
   1770 		struct sockaddr_in6 ssrc;
   1771 
   1772 		bzero(&sdst, sizeof(sdst));
   1773 		bzero(&sgw, sizeof(sgw));
   1774 		bzero(&ssrc, sizeof(ssrc));
   1775 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
   1776 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
   1777 			sizeof(struct sockaddr_in6);
   1778 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
   1779 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
   1780 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
   1781 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
   1782 			   (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
   1783 			   (struct sockaddr *)&ssrc,
   1784 			   (struct rtentry **)NULL
   1785 			   );
   1786 	}
   1787 	/* finally update cached route in each socket via pfctlinput */
   1788     {
   1789 	struct sockaddr_in6 sdst;
   1790 #if 1
   1791 #else
   1792 	struct ip6protosw *pr;
   1793 #endif
   1794 
   1795 	bzero(&sdst, sizeof(sdst));
   1796 	sdst.sin6_family = AF_INET6;
   1797 	sdst.sin6_len = sizeof(struct sockaddr_in6);
   1798 	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
   1799 #if 1
   1800 	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
   1801 #else
   1802 	/*
   1803 	 * do not use pfctlinput() here, we have different prototype for
   1804 	 * xx_ctlinput() in ip6proto.
   1805 	 */
   1806 	for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
   1807 	     pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW;
   1808 	     pr++) {
   1809 		if (pr->pr_ctlinput) {
   1810 			(*pr->pr_ctlinput)(PRC_REDIRECT_HOST,
   1811 				(struct sockaddr *)&sdst, NULL, NULL, 0);
   1812 		}
   1813 	}
   1814 #endif
   1815 #ifdef IPSEC
   1816 	key_sa_routechange((struct sockaddr *)&sdst);
   1817 #endif
   1818     }
   1819 
   1820  freeit:
   1821 	m_freem(m);
   1822 }
   1823 
   1824 void
   1825 icmp6_redirect_output(m0, rt)
   1826 	struct mbuf *m0;
   1827 	struct rtentry *rt;
   1828 {
   1829 	struct ifnet *ifp;	/* my outgoing interface */
   1830 	struct in6_addr *ifp_ll6;
   1831 	struct in6_addr *router_ll6;
   1832 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
   1833 	struct mbuf *m = NULL;	/* newly allocated one */
   1834 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
   1835 	struct nd_redirect *nd_rd;
   1836 	size_t maxlen;
   1837 	u_char *p;
   1838 	struct ifnet *outif = NULL;
   1839 
   1840 	/* if we are not router, we don't send icmp6 redirect */
   1841 	if (!ip6_forwarding || ip6_accept_rtadv)
   1842 		goto fail;
   1843 
   1844 	/* sanity check */
   1845 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
   1846 		goto fail;
   1847 
   1848 	/*
   1849 	 * Address check:
   1850 	 *  the source address must identify a neighbor, and
   1851 	 *  the destination address must not be a multicast address
   1852 	 *  [RFC 2461, sec 8.2]
   1853 	 */
   1854 	sip6 = mtod(m0, struct ip6_hdr *);
   1855 	if (nd6_is_addr_neighbor(&sip6->ip6_src, ifp) == 0)
   1856 		goto fail;
   1857 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
   1858 		goto fail;	/* what should we do here? */
   1859 
   1860 	/* rate limit */
   1861 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
   1862 		goto fail;
   1863 
   1864 	/*
   1865 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
   1866 	 * we almost always ask for an mbuf cluster for simplicity.
   1867 	 * (MHLEN < IPV6_MMTU is almost always true)
   1868 	 */
   1869 #if IPV6_MMTU >= MCLBYTES
   1870 # error assumption failed about IPV6_MMTU and MCLBYTES
   1871 #endif
   1872 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
   1873 	if (m && IPV6_MMTU >= MHLEN)
   1874 		MCLGET(m, M_DONTWAIT);
   1875 	if (!m)
   1876 		goto fail;
   1877 	maxlen = (m->m_flags & M_EXT) ? MCLBYTES : MHLEN;
   1878 	maxlen = min(IPV6_MMTU, maxlen);
   1879 	/* just for safety */
   1880 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
   1881 	    ((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
   1882 		goto fail;
   1883 	}
   1884 
   1885 	{
   1886 		/* get ip6 linklocal address for ifp(my outgoing interface). */
   1887 		struct in6_ifaddr *ia;
   1888 		if ((ia = in6ifa_ifpforlinklocal(ifp,
   1889 						 IN6_IFF_NOTREADY|
   1890 						 IN6_IFF_ANYCAST)) == NULL)
   1891 			goto fail;
   1892 		ifp_ll6 = &ia->ia_addr.sin6_addr;
   1893 	}
   1894 
   1895 	/* get ip6 linklocal address for the router. */
   1896 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
   1897 		struct sockaddr_in6 *sin6;
   1898 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
   1899 		router_ll6 = &sin6->sin6_addr;
   1900 		if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
   1901 			router_ll6 = (struct in6_addr *)NULL;
   1902 	} else
   1903 		router_ll6 = (struct in6_addr *)NULL;
   1904 
   1905 	/* ip6 */
   1906 	ip6 = mtod(m, struct ip6_hdr *);
   1907 	ip6->ip6_flow = 0;
   1908 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
   1909 	ip6->ip6_vfc |= IPV6_VERSION;
   1910 	/* ip6->ip6_plen will be set later */
   1911 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   1912 	ip6->ip6_hlim = 255;
   1913 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
   1914 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
   1915 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
   1916 
   1917 	/* ND Redirect */
   1918 	nd_rd = (struct nd_redirect *)(ip6 + 1);
   1919 	nd_rd->nd_rd_type = ND_REDIRECT;
   1920 	nd_rd->nd_rd_code = 0;
   1921 	nd_rd->nd_rd_reserved = 0;
   1922 	if (rt->rt_flags & RTF_GATEWAY) {
   1923 		/*
   1924 		 * nd_rd->nd_rd_target must be a link-local address in
   1925 		 * better router cases.
   1926 		 */
   1927 		if (!router_ll6)
   1928 			goto fail;
   1929 		bcopy(router_ll6, &nd_rd->nd_rd_target,
   1930 		      sizeof(nd_rd->nd_rd_target));
   1931 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
   1932 		      sizeof(nd_rd->nd_rd_dst));
   1933 	} else {
   1934 		/* make sure redtgt == reddst */
   1935 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
   1936 		      sizeof(nd_rd->nd_rd_target));
   1937 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
   1938 		      sizeof(nd_rd->nd_rd_dst));
   1939 	}
   1940 
   1941 	p = (u_char *)(nd_rd + 1);
   1942 
   1943 	if (!router_ll6)
   1944 		goto nolladdropt;
   1945 
   1946     {
   1947 	/* target lladdr option */
   1948 	struct rtentry *rt_router = NULL;
   1949 	int len;
   1950 	struct sockaddr_dl *sdl;
   1951 	struct nd_opt_hdr *nd_opt;
   1952 	char *lladdr;
   1953 
   1954 	rt_router = nd6_lookup(router_ll6, 0, ifp);
   1955 	if (!rt_router)
   1956 		goto nolladdropt;
   1957 	len = sizeof(*nd_opt) + ifp->if_addrlen;
   1958 	len = (len + 7) & ~7;	/*round by 8*/
   1959 	/* safety check */
   1960 	if (len + (p - (u_char *)ip6) > maxlen)
   1961 		goto nolladdropt;
   1962 	if (!(rt_router->rt_flags & RTF_GATEWAY) &&
   1963 	    (rt_router->rt_flags & RTF_LLINFO) &&
   1964 	    (rt_router->rt_gateway->sa_family == AF_LINK) &&
   1965 	    (sdl = (struct sockaddr_dl *)rt_router->rt_gateway) &&
   1966 	    sdl->sdl_alen) {
   1967 		nd_opt = (struct nd_opt_hdr *)p;
   1968 		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
   1969 		nd_opt->nd_opt_len = len >> 3;
   1970 		lladdr = (char *)(nd_opt + 1);
   1971 		bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
   1972 		p += len;
   1973 	}
   1974     }
   1975 nolladdropt:;
   1976 
   1977 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
   1978 
   1979 	/* just to be safe */
   1980 	if (m0->m_flags & M_DECRYPTED)
   1981 		goto noredhdropt;
   1982 	if (p - (u_char *)ip6 > maxlen)
   1983 		goto noredhdropt;
   1984 
   1985     {
   1986 	/* redirected header option */
   1987 	int len;
   1988 	struct nd_opt_rd_hdr *nd_opt_rh;
   1989 
   1990 	/*
   1991 	 * compute the maximum size for icmp6 redirect header option.
   1992 	 * XXX room for auth header?
   1993 	 */
   1994 	len = maxlen - (p - (u_char *)ip6);
   1995 	len &= ~7;
   1996 
   1997 	/* This is just for simplicity. */
   1998 	if (m0->m_pkthdr.len != m0->m_len) {
   1999 		if (m0->m_next) {
   2000 			m_freem(m0->m_next);
   2001 			m0->m_next = NULL;
   2002 		}
   2003 		m0->m_pkthdr.len = m0->m_len;
   2004 	}
   2005 
   2006 	/*
   2007 	 * Redirected header option spec (RFC2461 4.6.3) talks nothing
   2008 	 * about padding/truncate rule for the original IP packet.
   2009 	 * From the discussion on IPv6imp in Feb 1999, the consensus was:
   2010 	 * - "attach as much as possible" is the goal
   2011 	 * - pad if not aligned (original size can be guessed by original
   2012 	 *   ip6 header)
   2013 	 * Following code adds the padding if it is simple enough,
   2014 	 * and truncates if not.
   2015 	 */
   2016 	if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
   2017 		panic("assumption failed in %s:%d\n", __FILE__, __LINE__);
   2018 
   2019 	if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
   2020 		/* not enough room, truncate */
   2021 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
   2022 	} else {
   2023 		/* enough room, pad or truncate */
   2024 		size_t extra;
   2025 
   2026 		extra = m0->m_pkthdr.len % 8;
   2027 		if (extra) {
   2028 			/* pad if easy enough, truncate if not */
   2029 			if (8 - extra <= M_TRAILINGSPACE(m0)) {
   2030 				/* pad */
   2031 				m0->m_len += (8 - extra);
   2032 				m0->m_pkthdr.len += (8 - extra);
   2033 			} else {
   2034 				/* truncate */
   2035 				m0->m_pkthdr.len -= extra;
   2036 				m0->m_len -= extra;
   2037 			}
   2038 		}
   2039 		len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
   2040 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
   2041 	}
   2042 
   2043 	nd_opt_rh = (struct nd_opt_rd_hdr *)p;
   2044 	bzero(nd_opt_rh, sizeof(*nd_opt_rh));
   2045 	nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
   2046 	nd_opt_rh->nd_opt_rh_len = len >> 3;
   2047 	p += sizeof(*nd_opt_rh);
   2048 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
   2049 
   2050 	/* connect m0 to m */
   2051 	m->m_next = m0;
   2052 	m->m_pkthdr.len = m->m_len + m0->m_len;
   2053     }
   2054 noredhdropt:;
   2055 
   2056 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
   2057 		sip6->ip6_src.s6_addr16[1] = 0;
   2058 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
   2059 		sip6->ip6_dst.s6_addr16[1] = 0;
   2060 #if 0
   2061 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
   2062 		ip6->ip6_src.s6_addr16[1] = 0;
   2063 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
   2064 		ip6->ip6_dst.s6_addr16[1] = 0;
   2065 #endif
   2066 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
   2067 		nd_rd->nd_rd_target.s6_addr16[1] = 0;
   2068 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
   2069 		nd_rd->nd_rd_dst.s6_addr16[1] = 0;
   2070 
   2071 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
   2072 
   2073 	nd_rd->nd_rd_cksum = 0;
   2074 	nd_rd->nd_rd_cksum
   2075 		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
   2076 
   2077 	/* send the packet to outside... */
   2078 #ifdef IPSEC
   2079 	/* Don't lookup socket */
   2080 	ipsec_setsocket(m, NULL);
   2081 #endif /*IPSEC*/
   2082 	ip6_output(m, NULL, NULL, 0, NULL, &outif);
   2083 	if (outif) {
   2084 		icmp6_ifstat_inc(outif, ifs6_out_msg);
   2085 		icmp6_ifstat_inc(outif, ifs6_out_redirect);
   2086 	}
   2087 	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
   2088 
   2089 	return;
   2090 
   2091 fail:
   2092 	if (m)
   2093 		m_freem(m);
   2094 	if (m0)
   2095 		m_freem(m0);
   2096 }
   2097 
   2098 /*
   2099  * ICMPv6 socket option processing.
   2100  */
   2101 int
   2102 icmp6_ctloutput(op, so, level, optname, mp)
   2103 	int op;
   2104 	struct socket *so;
   2105 	int level, optname;
   2106 	struct mbuf **mp;
   2107 {
   2108 	register struct in6pcb *in6p = sotoin6pcb(so);
   2109 	register struct mbuf *m = *mp;
   2110 	int error = 0;
   2111 
   2112 	if (level != IPPROTO_ICMPV6) {
   2113 		error = EINVAL;
   2114 		if (op == PRCO_SETOPT && m)
   2115 			(void)m_free(m);
   2116 	} else switch(op) {
   2117 	 case PRCO_SETOPT:
   2118 		 switch (optname) {
   2119 		  case ICMP6_FILTER:
   2120 		  {
   2121 			  struct icmp6_filter *p;
   2122 
   2123 			  p = mtod(m, struct icmp6_filter *);
   2124 			  if (!p || !in6p->in6p_icmp6filt) {
   2125 				  error = EINVAL;
   2126 				  break;
   2127 			  }
   2128 			  bcopy(p, in6p->in6p_icmp6filt,
   2129 				sizeof(struct icmp6_filter));
   2130 			  error = 0;
   2131 			  break;
   2132 		  }
   2133 
   2134 		  default:
   2135 			  error = ENOPROTOOPT;
   2136 			  break;
   2137 		 }
   2138 		 if (m)
   2139 			 (void)m_free(m);
   2140 		 break;
   2141 
   2142 	 case PRCO_GETOPT:
   2143 		 switch (optname) {
   2144 		  case ICMP6_FILTER:
   2145 		  {
   2146 			  struct icmp6_filter *p;
   2147 
   2148 			  if (!in6p->in6p_icmp6filt) {
   2149 				  error = EINVAL;
   2150 				  break;
   2151 			  }
   2152 			  *mp = m = m_get(M_WAIT, MT_SOOPTS);
   2153 			  m->m_len = sizeof(struct icmp6_filter);
   2154 			  p = mtod(m, struct icmp6_filter *);
   2155 			  bcopy(in6p->in6p_icmp6filt, p,
   2156 				sizeof(struct icmp6_filter));
   2157 			  error = 0;
   2158 			  break;
   2159 		  }
   2160 
   2161 		  default:
   2162 			  error = ENOPROTOOPT;
   2163 			  break;
   2164 		 }
   2165 		 break;
   2166 	}
   2167 
   2168 	return(error);
   2169 }
   2170 
   2171 /*
   2172  * Perform rate limit check.
   2173  * Returns 0 if it is okay to send the icmp6 packet.
   2174  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
   2175  * limitation.
   2176  *
   2177  * XXX per-destination/type check necessary?
   2178  */
   2179 static int
   2180 icmp6_ratelimit(dst, type, code)
   2181 	const struct in6_addr *dst;	/* not used at this moment */
   2182 	const int type;			/* not used at this moment */
   2183 	const int code;			/* not used at this moment */
   2184 {
   2185 	static struct timeval icmp6errratelim_last;
   2186 
   2187 	/*
   2188 	 * ratecheck() returns true if it is okay to send.  We return
   2189 	 * true if it is not okay to send.
   2190 	 */
   2191 	return (ratecheck(&icmp6errratelim_last, &icmp6errratelim) == 0);
   2192 }
   2193 
   2194 static struct rtentry *
   2195 icmp6_mtudisc_clone(dst)
   2196 	struct sockaddr *dst;
   2197 {
   2198 	struct rtentry *rt;
   2199 	int    error;
   2200 
   2201 	rt = rtalloc1(dst, 1);
   2202 	if (rt == 0)
   2203 		return NULL;
   2204 
   2205 	/* If we didn't get a host route, allocate one */
   2206 	if ((rt->rt_flags & RTF_HOST) == 0) {
   2207 		struct rtentry *nrt;
   2208 
   2209 		error = rtrequest((int) RTM_ADD, dst,
   2210 		    (struct sockaddr *) rt->rt_gateway,
   2211 		    (struct sockaddr *) 0,
   2212 		    RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
   2213 		if (error) {
   2214 			rtfree(rt);
   2215 			rtfree(nrt);
   2216 			return NULL;
   2217 		}
   2218 		nrt->rt_rmx = rt->rt_rmx;
   2219 		rtfree(rt);
   2220 		rt = nrt;
   2221 	}
   2222 	error = rt_timer_add(rt, icmp6_mtudisc_timeout,
   2223 			icmp6_mtudisc_timeout_q);
   2224 	if (error) {
   2225 		rtfree(rt);
   2226 		return NULL;
   2227 	}
   2228 
   2229 	return rt;	/* caller need to call rtfree() */
   2230 }
   2231 
   2232 static void
   2233 icmp6_mtudisc_timeout(rt, r)
   2234 	struct rtentry *rt;
   2235 	struct rttimer *r;
   2236 {
   2237 	if (rt == NULL)
   2238 		panic("icmp6_mtudisc_timeout: bad route to timeout");
   2239 	if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
   2240 	    (RTF_DYNAMIC | RTF_HOST)) {
   2241 		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
   2242 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
   2243 	} else {
   2244 		if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
   2245 			rt->rt_rmx.rmx_mtu = 0;
   2246 		}
   2247 	}
   2248 }
   2249 
   2250 #include <vm/vm.h>
   2251 #include <sys/sysctl.h>
   2252 int
   2253 icmp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
   2254 	int *name;
   2255 	u_int namelen;
   2256 	void *oldp;
   2257 	size_t *oldlenp;
   2258 	void *newp;
   2259 	size_t newlen;
   2260 {
   2261 
   2262 	/* All sysctl names at this level are terminal. */
   2263 	if (namelen != 1)
   2264 		return ENOTDIR;
   2265 
   2266 	switch (name[0]) {
   2267 
   2268 	case ICMPV6CTL_REDIRACCEPT:
   2269 		return sysctl_int(oldp, oldlenp, newp, newlen,
   2270 				&icmp6_rediraccept);
   2271 	case ICMPV6CTL_REDIRTIMEOUT:
   2272 		return sysctl_int(oldp, oldlenp, newp, newlen,
   2273 				&icmp6_redirtimeout);
   2274 	case ICMPV6CTL_STATS:
   2275 		return sysctl_rdstruct(oldp, oldlenp, newp,
   2276 				&icmp6stat, sizeof(icmp6stat));
   2277 	case ICMPV6CTL_ERRRATELIMIT:
   2278 	    {
   2279 		int rate_usec, error, s;
   2280 
   2281 		/*
   2282 		 * The sysctl specifies the rate in usec-between-icmp,
   2283 		 * so we must convert from/to a timeval.
   2284 		 */
   2285 		rate_usec = (icmp6errratelim.tv_sec * 1000000) +
   2286 		    icmp6errratelim.tv_usec;
   2287 		error = sysctl_int(oldp, oldlenp, newp, newlen, &rate_usec);
   2288 		if (error)
   2289 			return (error);
   2290 		s = splsoftnet();
   2291 		icmp6errratelim.tv_sec = rate_usec / 1000000;
   2292 		icmp6errratelim.tv_usec = rate_usec % 1000000;
   2293 		splx(s);
   2294 
   2295 		return (0);
   2296 	    }
   2297 	case ICMPV6CTL_ND6_PRUNE:
   2298 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_prune);
   2299 	case ICMPV6CTL_ND6_DELAY:
   2300 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_delay);
   2301 	case ICMPV6CTL_ND6_UMAXTRIES:
   2302 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_umaxtries);
   2303 	case ICMPV6CTL_ND6_MMAXTRIES:
   2304 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_mmaxtries);
   2305 	case ICMPV6CTL_ND6_USELOOPBACK:
   2306 		return sysctl_int(oldp, oldlenp, newp, newlen,
   2307 				&nd6_useloopback);
   2308 	case ICMPV6CTL_NODEINFO:
   2309 		return sysctl_int(oldp, oldlenp, newp, newlen, &icmp6_nodeinfo);
   2310 	default:
   2311 		return ENOPROTOOPT;
   2312 	}
   2313 	/* NOTREACHED */
   2314 }
   2315