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icmp6.c revision 1.11
      1 /*	$NetBSD: icmp6.c,v 1.11 1999/10/01 10:16:16 itojun Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the project nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 1982, 1986, 1988, 1993
     34  *	The Regents of the University of California.  All rights reserved.
     35  *
     36  * Redistribution and use in source and binary forms, with or without
     37  * modification, are permitted provided that the following conditions
     38  * are met:
     39  * 1. Redistributions of source code must retain the above copyright
     40  *    notice, this list of conditions and the following disclaimer.
     41  * 2. Redistributions in binary form must reproduce the above copyright
     42  *    notice, this list of conditions and the following disclaimer in the
     43  *    documentation and/or other materials provided with the distribution.
     44  * 3. All advertising materials mentioning features or use of this software
     45  *    must display the following acknowledgement:
     46  *	This product includes software developed by the University of
     47  *	California, Berkeley and its contributors.
     48  * 4. Neither the name of the University nor the names of its contributors
     49  *    may be used to endorse or promote products derived from this software
     50  *    without specific prior written permission.
     51  *
     52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     62  * SUCH DAMAGE.
     63  *
     64  *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
     65  */
     66 
     67 #if (defined(__FreeBSD__) && __FreeBSD__ >= 3) || defined(__NetBSD__)
     68 #include "opt_inet.h"
     69 #ifdef __NetBSD__	/*XXX*/
     70 #include "opt_ipsec.h"
     71 #endif
     72 #endif
     73 
     74 #include <sys/param.h>
     75 #include <sys/systm.h>
     76 #include <sys/malloc.h>
     77 #include <sys/mbuf.h>
     78 #include <sys/protosw.h>
     79 #include <sys/socket.h>
     80 #include <sys/socketvar.h>
     81 #include <sys/time.h>
     82 #include <sys/kernel.h>
     83 #include <sys/syslog.h>
     84 
     85 #include <net/if.h>
     86 #include <net/route.h>
     87 #include <net/if_dl.h>
     88 #include <net/if_types.h>
     89 
     90 #include <netinet/in.h>
     91 #include <netinet/in_var.h>
     92 #include <netinet6/ip6.h>
     93 #include <netinet6/ip6_var.h>
     94 #include <netinet6/icmp6.h>
     95 #include <netinet6/mld6_var.h>
     96 #if !defined(__FreeBSD__) || __FreeBSD__ < 3
     97 #include <netinet6/in6_pcb.h>
     98 #else
     99 #include <netinet/in_pcb.h>
    100 #endif
    101 #include <netinet6/nd6.h>
    102 #include <netinet6/in6_ifattach.h>
    103 #include <netinet6/ip6protosw.h>
    104 
    105 #ifdef IPSEC
    106 #include <netkey/key.h>
    107 #include <netkey/key_debug.h>
    108 #endif
    109 
    110 #include "faith.h"
    111 
    112 extern struct ip6protosw inet6sw[];
    113 extern u_char ip6_protox[];
    114 
    115 struct icmp6stat icmp6stat;
    116 
    117 #if !defined(__FreeBSD__) || __FreeBSD__ < 3
    118 extern struct in6pcb rawin6pcb;
    119 #else
    120 extern struct inpcbhead ripcb;
    121 #endif
    122 extern u_int icmp6errratelim;
    123 #ifdef __NetBSD__
    124 static struct rttimer_queue *icmp6_mtudisc_timeout_q = NULL;
    125 extern int pmtu_expire;
    126 #endif
    127 
    128 static int icmp6_rip6_input __P((struct mbuf **, int));
    129 static int icmp6_ratelimit __P((const struct in6_addr *, const int, const int));
    130 static void icmp6_redirect_diag __P((int, struct in6_addr *, struct in6_addr *,
    131 	struct in6_addr *));
    132 static struct mbuf * ni6_input __P((struct mbuf *, int));
    133 static int ni6_addrs __P((struct icmp6_nodeinfo *, struct mbuf *,
    134 			  struct ifnet **));
    135 static int ni6_store_addrs __P((struct icmp6_nodeinfo *, struct icmp6_nodeinfo *,
    136 				struct ifnet *, int));
    137 #ifdef __NetBSD__
    138 static struct rtentry *icmp6_mtudisc_clone __P((struct sockaddr *));
    139 static void icmp6_mtudisc_timeout __P((struct rtentry *, struct rttimer *));
    140 #endif
    141 
    142 #ifdef COMPAT_RFC1885
    143 static struct route_in6 icmp6_reflect_rt;
    144 #endif
    145 static struct timeval icmp6_nextsend = {0, 0};
    146 
    147 void
    148 icmp6_init()
    149 {
    150 	mld6_init();
    151 #ifdef __NetBSD__
    152 	icmp6_mtudisc_timeout_q = rt_timer_queue_create(pmtu_expire);
    153 #endif
    154 }
    155 
    156 /*
    157  * Generate an error packet of type error in response to bad IP6 packet.
    158  */
    159 void
    160 icmp6_error(m, type, code, param)
    161 	struct mbuf *m;
    162 	int type, code, param;
    163 {
    164 	struct ip6_hdr *oip6, *nip6;
    165 	struct icmp6_hdr *icmp6;
    166 	u_int prep;
    167 	int off;
    168 	u_char nxt;
    169 
    170 	icmp6stat.icp6s_error++;
    171 
    172 	if (m->m_flags & M_DECRYPTED)
    173 		goto freeit;
    174 
    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 	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
    198 	off = sizeof(struct ip6_hdr);
    199 	nxt = oip6->ip6_nxt;
    200 	while(1) {		/* XXX: should avoid inf. loop explicitly? */
    201 		struct ip6_ext *ip6e;
    202 		struct icmp6_hdr *icp;
    203 
    204 		switch(nxt) {
    205 		case IPPROTO_IPV6:
    206 		case IPPROTO_IPV4:
    207 		case IPPROTO_UDP:
    208 		case IPPROTO_TCP:
    209 		case IPPROTO_ESP:
    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 			IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
    220 			icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
    221 			if (icp->icmp6_type < ICMP6_ECHO_REQUEST
    222 			 || icp->icmp6_type == ND_REDIRECT) {
    223 				/*
    224 				 * ICMPv6 error
    225 				 * Special case: for redirect (which is
    226 				 * informational) we must not send icmp6 error.
    227 				 */
    228 				icmp6stat.icp6s_canterror++;
    229 				goto freeit;
    230 			} else {
    231 				/* ICMPv6 informational */
    232 				goto generate;
    233 			}
    234 		case IPPROTO_HOPOPTS:
    235 		case IPPROTO_DSTOPTS:
    236 		case IPPROTO_ROUTING:
    237 		case IPPROTO_AH:
    238 			IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct ip6_ext), );
    239 			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
    240 			if (nxt == IPPROTO_AH)
    241 				off += (ip6e->ip6e_len + 2) << 2;
    242 			else
    243 				off += (ip6e->ip6e_len + 1) << 3;
    244 			nxt = ip6e->ip6e_nxt;
    245 			break;
    246 		}
    247 	}
    248 
    249   freeit:
    250 	/*
    251 	 * If we can't tell wheter or not we can generate ICMP6, free it.
    252 	 */
    253 	m_freem(m);
    254 	return;
    255 
    256   generate:
    257 	oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
    258 
    259 	/* Finally, do rate limitation check. */
    260 	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
    261 		icmp6stat.icp6s_toofreq++;
    262 		goto freeit;
    263 	}
    264 
    265 	/*
    266 	 * OK, ICMP6 can be generated.
    267 	 */
    268 
    269 	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
    270 		m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);
    271 
    272 	prep = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
    273 	M_PREPEND(m, prep, M_DONTWAIT);
    274 	if (m && m->m_len < prep)
    275 		m = m_pullup(m, prep);
    276 	if (m == NULL) {
    277 		printf("ENOBUFS in icmp6_error %d\n", __LINE__);
    278 		return;
    279 	}
    280 
    281 	nip6 = mtod(m, struct ip6_hdr *);
    282 	nip6->ip6_src  = oip6->ip6_src;
    283 	nip6->ip6_dst  = oip6->ip6_dst;
    284 
    285 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_src))
    286 		oip6->ip6_src.s6_addr16[1] = 0;
    287 	if (IN6_IS_SCOPE_LINKLOCAL(&oip6->ip6_dst))
    288 		oip6->ip6_dst.s6_addr16[1] = 0;
    289 
    290 	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
    291 	icmp6->icmp6_type = type;
    292 	icmp6->icmp6_code = code;
    293 	icmp6->icmp6_pptr = htonl((u_int32_t)param);
    294 
    295 	icmp6stat.icp6s_outhist[type]++;
    296 	icmp6_reflect(m, sizeof(struct ip6_hdr)); /*header order: IPv6 - ICMPv6*/
    297 }
    298 
    299 /*
    300  * Process a received ICMP6 message.
    301  */
    302 int
    303 icmp6_input(mp, offp, proto)
    304 	struct mbuf **mp;
    305 	int *offp, proto;
    306 {
    307 	struct mbuf *m = *mp, *n;
    308 	struct ip6_hdr *ip6, *nip6;
    309 	struct icmp6_hdr *icmp6, *nicmp6;
    310 	int off = *offp;
    311 	int icmp6len = m->m_pkthdr.len - *offp;
    312 	int code, sum, noff;
    313 	struct sockaddr_in6 icmp6src;
    314 
    315 	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
    316 	/* m might change if M_LOOP. So, call mtod after this */
    317 
    318 	/*
    319 	 * Locate icmp6 structure in mbuf, and check
    320 	 * that not corrupted and of at least minimum length
    321 	 */
    322 
    323 	ip6 = mtod(m, struct ip6_hdr *);
    324 	if (icmp6len < sizeof(struct icmp6_hdr)) {
    325 		icmp6stat.icp6s_tooshort++;
    326 		goto freeit;
    327 	}
    328 
    329 	/*
    330 	 * calculate the checksum
    331 	 */
    332 
    333 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
    334 	code = icmp6->icmp6_code;
    335 
    336 	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
    337 		log(LOG_ERR,
    338 		    "ICMP6 checksum error(%d|%x) %s\n",
    339 		    icmp6->icmp6_type,
    340 		    sum,
    341 		    ip6_sprintf(&ip6->ip6_src));
    342 		icmp6stat.icp6s_checksum++;
    343 		goto freeit;
    344 	}
    345 
    346 #if defined(NFAITH) && 0 < NFAITH
    347 	if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
    348 		/*
    349 		 * Deliver very specific ICMP6 type only.
    350 		 * This is important to deilver TOOBIG.  Otherwise PMTUD
    351 		 * will not work.
    352 		 */
    353 		switch (icmp6->icmp6_type) {
    354 		case ICMP6_DST_UNREACH:
    355 		case ICMP6_PACKET_TOO_BIG:
    356 		case ICMP6_TIME_EXCEEDED:
    357 			break;
    358 		default:
    359 			goto freeit;
    360 		}
    361 	}
    362 #endif
    363 
    364 #ifdef IPSEC
    365 	/* drop it if it does not match the default policy */
    366 	if (ipsec6_in_reject(m, NULL)) {
    367 		ipsecstat.in_polvio++;
    368 		goto freeit;
    369 	}
    370 #endif
    371 
    372 	icmp6stat.icp6s_inhist[icmp6->icmp6_type]++;
    373 
    374 	switch (icmp6->icmp6_type) {
    375 
    376 	case ICMP6_DST_UNREACH:
    377 		switch (code) {
    378 		case ICMP6_DST_UNREACH_NOROUTE:
    379 			code = PRC_UNREACH_NET;
    380 			break;
    381 		case ICMP6_DST_UNREACH_ADMIN:
    382 		case ICMP6_DST_UNREACH_ADDR:
    383 			code = PRC_UNREACH_HOST;
    384 			break;
    385 		case ICMP6_DST_UNREACH_NOTNEIGHBOR:
    386 			code = PRC_UNREACH_SRCFAIL;
    387 			break;
    388 		case ICMP6_DST_UNREACH_NOPORT:
    389 			code = PRC_UNREACH_PORT;
    390 			break;
    391 		default:
    392 			goto badcode;
    393 		}
    394 		goto deliver;
    395 		break;
    396 
    397 	case ICMP6_PACKET_TOO_BIG:
    398 		if (code != 0)
    399 			goto badcode;
    400 	    {
    401 		u_int mtu = ntohl(icmp6->icmp6_mtu);
    402 		struct rtentry *rt;
    403 		struct sockaddr_in6 sin6;
    404 #ifdef __bsdi__
    405 		struct route_in6 ro6;
    406 #endif
    407 
    408 		code = PRC_MSGSIZE;
    409 		bzero(&sin6, sizeof(sin6));
    410 		sin6.sin6_family = PF_INET6;
    411 		sin6.sin6_len = sizeof(struct sockaddr_in6);
    412 		sin6.sin6_addr = ((struct ip6_hdr *)(icmp6 + 1))->ip6_dst;
    413 #ifdef __NetBSD__
    414 		rt = rtalloc1((struct sockaddr *)&sin6, 1);	/*clone*/
    415 		if (!rt || (rt->rt_flags & RTF_HOST) == 0) {
    416 			if (rt)
    417 				RTFREE(rt);
    418 			rt = icmp6_mtudisc_clone((struct sockaddr *)&sin6);
    419 		}
    420 #endif
    421 #ifdef __FreeBSD__
    422 		rt = rtalloc1((struct sockaddr *)&sin6, 0,
    423 			RTF_CLONING | RTF_PRCLONING);
    424 #endif /*__FreeBSD__*/
    425 #ifdef __bsdi__
    426 		bcopy(&sin6, &ro6.ro_dst, sizeof(struct sockaddr_in6));
    427 		ro6.ro_rt = 0;
    428 		rtcalloc((struct route *)&ro6);
    429 		rt = ro6.ro_rt;
    430 #endif /*__bsdi__*/
    431 
    432 		if (rt && (rt->rt_flags & RTF_HOST)
    433 		    && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
    434 			if (mtu < IPV6_MMTU) {
    435 				/* xxx */
    436 				rt->rt_rmx.rmx_locks |= RTV_MTU;
    437 			} else if (mtu < rt->rt_ifp->if_mtu &&
    438 				   rt->rt_rmx.rmx_mtu > mtu) {
    439 				rt->rt_rmx.rmx_mtu = mtu;
    440 			}
    441 		}
    442 		if (rt)
    443 			RTFREE(rt);
    444 
    445 		goto deliver;
    446 	    }
    447 		break;
    448 
    449 	case ICMP6_TIME_EXCEEDED:
    450 		switch (code) {
    451 		case ICMP6_TIME_EXCEED_TRANSIT:
    452 		case ICMP6_TIME_EXCEED_REASSEMBLY:
    453 			code += PRC_TIMXCEED_INTRANS;
    454 			break;
    455 		default:
    456 			goto badcode;
    457 		}
    458 		goto deliver;
    459 		break;
    460 
    461 	case ICMP6_PARAM_PROB:
    462 		switch (code) {
    463 		case ICMP6_PARAMPROB_NEXTHEADER:
    464 			code = PRC_UNREACH_PROTOCOL;
    465 			break;
    466 		case ICMP6_PARAMPROB_HEADER:
    467 		case ICMP6_PARAMPROB_OPTION:
    468 			code = PRC_PARAMPROB;
    469 			break;
    470 		default:
    471 			goto badcode;
    472 		}
    473 		goto deliver;
    474 		break;
    475 
    476 	case ICMP6_ECHO_REQUEST:
    477 		if (code != 0)
    478 			goto badcode;
    479 		if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
    480 			/* Give up remote */
    481 			break;
    482 		}
    483 		if (n->m_flags & M_EXT) {
    484 			int gap, move;
    485 			struct mbuf *n0 = n;
    486 
    487 			/*
    488 			 * Prepare an internal mbuf. m_pullup() doesn't
    489 			 * always copy the length we specified.
    490 			 */
    491 			MGETHDR(n, M_DONTWAIT, n0->m_type);
    492 			if (n == NULL) {
    493 				/* Give up remote */
    494 				m_freem(n0);
    495 				break;
    496 			}
    497 			M_COPY_PKTHDR(n, n0);
    498 			n0->m_flags &= ~M_PKTHDR;
    499 			n->m_next = n0;
    500 			/*
    501 			 * Copy IPv6 and ICMPv6 only.
    502 			 */
    503 			nip6 = mtod(n, struct ip6_hdr *);
    504 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
    505 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
    506 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
    507 			/*
    508 			 * Adjust mbuf. ip6_plen will be adjusted.
    509 			 */
    510 			noff = sizeof(struct ip6_hdr);
    511 			n->m_len = noff + sizeof(struct icmp6_hdr);
    512 			move = off + sizeof(struct icmp6_hdr);
    513 			n0->m_len -= move;
    514 			n0->m_data += move;
    515 			gap = off - noff;
    516 			n->m_pkthdr.len -= gap;
    517 		} else {
    518 			nip6 = mtod(n, struct ip6_hdr *);
    519 			nicmp6 = (struct icmp6_hdr *)((caddr_t)nip6 + off);
    520 			noff = off;
    521 		}
    522 		nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
    523 		nicmp6->icmp6_code = 0;
    524 		if (n) {
    525 			icmp6stat.icp6s_reflect++;
    526 			icmp6stat.icp6s_outhist[ICMP6_ECHO_REPLY]++;
    527 			icmp6_reflect(n, noff);
    528 		}
    529 		break;
    530 
    531 	case ICMP6_ECHO_REPLY:
    532 		if (code != 0)
    533 			goto badcode;
    534 		break;
    535 
    536 	case MLD6_LISTENER_QUERY:
    537 	case MLD6_LISTENER_REPORT:
    538 		if (icmp6len < sizeof(struct mld6_hdr))
    539 			goto badlen;
    540 		IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
    541 		mld6_input(m, off);
    542 		/* m stays. */
    543 		break;
    544 
    545 	case MLD6_LISTENER_DONE:
    546 		if (icmp6len < sizeof(struct mld6_hdr))
    547 			goto badlen;
    548 		break;		/* nothing to be done in kernel */
    549 
    550 	case ICMP6_WRUREQUEST:	/* ICMP6_FQDN_QUERY */
    551 	    {
    552 		enum { WRU, FQDN } mode;
    553 
    554 		if (code != 0)
    555 			goto badcode;
    556 		if (icmp6len == sizeof(struct icmp6_hdr) + 4)
    557 			mode = WRU;
    558 		else if (icmp6len >= sizeof(struct icmp6_hdr) + 8) /* XXX */
    559 			mode = FQDN;
    560 		else
    561 			goto badlen;
    562 
    563 #ifdef __FreeBSD__
    564 #define hostnamelen	strlen(hostname)
    565 #endif
    566 		if (mode == FQDN) {
    567 			IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
    568 					 IPPROTO_DONE);
    569 			n = ni6_input(m, off);
    570 			noff = sizeof(struct ip6_hdr);
    571 		}
    572 		else {
    573 			u_char *p;
    574 
    575 			MGETHDR(n, M_DONTWAIT, m->m_type);
    576 			if (n == NULL) {
    577 				/* Give up remote */
    578 				break;
    579 			}
    580 			/*
    581 			 * Copy IPv6 and ICMPv6 only.
    582 			 */
    583 			nip6 = mtod(n, struct ip6_hdr *);
    584 			bcopy(ip6, nip6, sizeof(struct ip6_hdr));
    585 			nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
    586 			bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
    587 			p = (u_char *)(nicmp6 + 1);
    588 			bzero(p, 4);
    589 			bcopy(hostname, p + 4, hostnamelen);
    590 			noff = sizeof(struct ip6_hdr);
    591 			M_COPY_PKTHDR(n, m); /* just for recvif */
    592 			n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
    593 				sizeof(struct icmp6_hdr) + 4 + hostnamelen;
    594 			nicmp6->icmp6_type = ICMP6_WRUREPLY;
    595 			nicmp6->icmp6_code = 0;
    596 		}
    597 #undef hostnamelen
    598 		if (n) {
    599 			icmp6stat.icp6s_reflect++;
    600 			icmp6stat.icp6s_outhist[ICMP6_WRUREPLY]++;
    601 			icmp6_reflect(n, noff);
    602 		}
    603 		break;
    604 	    }
    605 
    606 	case ICMP6_WRUREPLY:
    607 		if (code != 0)
    608 			goto badcode;
    609 		break;
    610 
    611 	case ND_ROUTER_SOLICIT:
    612 		if (code != 0)
    613 			goto badcode;
    614 		if (icmp6len < sizeof(struct nd_router_solicit))
    615 			goto badlen;
    616 		IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
    617 		nd6_rs_input(m, off, icmp6len);
    618 		/* m stays. */
    619 		break;
    620 
    621 	case ND_ROUTER_ADVERT:
    622 		if (code != 0)
    623 			goto badcode;
    624 		if (icmp6len < sizeof(struct nd_router_advert))
    625 			goto badlen;
    626 		IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
    627 		nd6_ra_input(m, off, icmp6len);
    628 		/* m stays. */
    629 		break;
    630 
    631 	case ND_NEIGHBOR_SOLICIT:
    632 		if (code != 0)
    633 			goto badcode;
    634 		if (icmp6len < sizeof(struct nd_neighbor_solicit))
    635 			goto badlen;
    636 		IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
    637 		nd6_ns_input(m, off, icmp6len);
    638 		/* m stays. */
    639 		break;
    640 
    641 	case ND_NEIGHBOR_ADVERT:
    642 		if (code != 0)
    643 			goto badcode;
    644 		if (icmp6len < sizeof(struct nd_neighbor_advert))
    645 			goto badlen;
    646 		IP6_EXTHDR_CHECK(m, off, icmp6len, IPPROTO_DONE);
    647 		nd6_na_input(m, off, icmp6len);
    648 		/* m stays. */
    649 		break;
    650 
    651 	case ND_REDIRECT:
    652 		if (code != 0)
    653 			goto badcode;
    654 		if (icmp6len < sizeof(struct nd_redirect))
    655 			goto badlen;
    656 		icmp6_redirect_input(m, off);
    657 		/* m stays. */
    658 		break;
    659 
    660 	case ICMP6_ROUTER_RENUMBERING:
    661 		if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
    662 		    code != ICMP6_ROUTER_RENUMBERING_RESULT)
    663 			goto badcode;
    664 		if (icmp6len < sizeof(struct icmp6_router_renum))
    665 			goto badlen;
    666 		break;
    667 
    668 	default:
    669 		printf("icmp6_input: unknown type %d\n", icmp6->icmp6_type);
    670 		if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
    671 			/* ICMPv6 error: MUST deliver it by spec... */
    672 			code = PRC_NCMDS;
    673 			/* deliver */
    674 		} else {
    675 			/* ICMPv6 informational: MUST not deliver */
    676 			break;
    677 		}
    678 	deliver:
    679 		if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
    680 			icmp6stat.icp6s_tooshort++;
    681 			goto freeit;
    682 		}
    683 		IP6_EXTHDR_CHECK(m, off,
    684 			sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr),
    685 			IPPROTO_DONE);
    686 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
    687 		bzero(&icmp6src, sizeof(icmp6src));
    688 		icmp6src.sin6_len = sizeof(struct sockaddr_in6);
    689 		icmp6src.sin6_family = AF_INET6;
    690 		icmp6src.sin6_addr = ((struct ip6_hdr *)(icmp6 + 1))->ip6_dst;
    691 
    692 		/* Detect the upper level protocol */
    693 	    {
    694 		void (*ctlfunc) __P((int, struct sockaddr *,
    695 				     struct ip6_hdr *,
    696 				     struct mbuf *, int)); /* XXX */
    697 		struct ip6_hdr *eip6 = (struct ip6_hdr *)(icmp6 + 1);
    698 		u_int8_t nxt = eip6->ip6_nxt;
    699 		int eoff = off + sizeof(struct icmp6_hdr) +
    700 			sizeof(struct ip6_hdr);
    701 
    702 		while (1) { /* XXX: should avoid inf. loop explicitly? */
    703 			struct ip6_ext *eh;
    704 
    705 			switch(nxt) {
    706 			case IPPROTO_ESP:
    707 			case IPPROTO_NONE:
    708 				goto passit;
    709 			case IPPROTO_HOPOPTS:
    710 			case IPPROTO_DSTOPTS:
    711 			case IPPROTO_ROUTING:
    712 			case IPPROTO_AH:
    713 			case IPPROTO_FRAGMENT:
    714 				IP6_EXTHDR_CHECK(m, 0, eoff +
    715 						 sizeof(struct ip6_ext),
    716 						 IPPROTO_DONE);
    717 				eh = (struct ip6_ext *)(mtod(m, caddr_t)
    718 							+ eoff);
    719 				if (nxt == IPPROTO_AH)
    720 					eoff += (eh->ip6e_len + 2) << 2;
    721 				else if (nxt == IPPROTO_FRAGMENT)
    722 					eoff += sizeof(struct ip6_frag);
    723 				else
    724 					eoff += (eh->ip6e_len + 1) << 3;
    725 				nxt = eh->ip6e_nxt;
    726 				break;
    727 			default:
    728 				goto notify;
    729 			}
    730 		}
    731 	    notify:
    732 		icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
    733 		ctlfunc = (void (*) __P((int, struct sockaddr *,
    734 					 struct ip6_hdr *,
    735 					 struct mbuf *, int)))
    736 			(inet6sw[ip6_protox[nxt]].pr_ctlinput);
    737 		if (ctlfunc)
    738 			(*ctlfunc)(code, (struct sockaddr *)&icmp6src,
    739 				   (struct ip6_hdr *)(icmp6 + 1),
    740 				   m, eoff);
    741 	    }
    742 		break;
    743 
    744 	badcode:
    745 		icmp6stat.icp6s_badcode++;
    746 		break;
    747 
    748 	badlen:
    749 		icmp6stat.icp6s_badlen++;
    750 		break;
    751 	}
    752 
    753  passit:
    754 	icmp6_rip6_input(&m, *offp);
    755 	return IPPROTO_DONE;
    756 
    757  freeit:
    758 	m_freem(m);
    759 	return IPPROTO_DONE;
    760 }
    761 
    762 /*
    763  * Process a Node Information Query
    764  */
    765 #ifdef __FreeBSD__
    766 #define hostnamelen	strlen(hostname)
    767 #endif
    768 #ifndef offsetof		/* XXX */
    769 #define	offsetof(type, member)	((size_t)(&((type *)0)->member))
    770 #endif
    771 
    772 static struct mbuf *
    773 ni6_input(m, off)
    774 	struct mbuf *m;
    775 	int off;
    776 {
    777 	struct icmp6_nodeinfo *ni6 =
    778 		(struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off), *nni6;
    779 	struct mbuf *n = NULL;
    780 	u_int16_t qtype = ntohs(ni6->ni_qtype);
    781 	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
    782 	struct ni_reply_fqdn *fqdn;
    783 	int addrs;		/* for NI_QTYPE_NODEADDR */
    784 	struct ifnet *ifp = NULL; /* for NI_QTYPE_NODEADDR */
    785 
    786 	switch(qtype) {
    787 	 case NI_QTYPE_NOOP:
    788 		 break;		/* no reply data */
    789 	 case NI_QTYPE_SUPTYPES:
    790 		 goto bad;	/* xxx: to be implemented */
    791 		 break;
    792 	 case NI_QTYPE_FQDN:
    793 		 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_name) +
    794 			 hostnamelen;
    795 		 break;
    796 	 case NI_QTYPE_NODEADDR:
    797 		 addrs = ni6_addrs(ni6, m, &ifp);
    798 		 if ((replylen += addrs * sizeof(struct in6_addr)) > MCLBYTES)
    799 			 replylen = MCLBYTES; /* XXX: we'll truncate later */
    800 
    801 		 break;
    802 	 default:
    803 		 /*
    804 		  * XXX: We must return a reply with the ICMP6 code
    805 		  * `unknown Qtype' in this case. However we regard the case
    806 		  * as an FQDN query for backward compatibility.
    807 		  * Older versions set a random value to this field,
    808 		  * so it rarely varies in the defined qtypes.
    809 		  * But the mechanism is not reliable...
    810 		  * maybe we should obsolete older versions.
    811 		  */
    812 		 qtype = NI_QTYPE_FQDN;
    813 		 replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_name) +
    814 			 hostnamelen;
    815 		 break;
    816 	}
    817 
    818 	/* allocate a mbuf to reply. */
    819 	MGETHDR(n, M_DONTWAIT, m->m_type);
    820 	if (n == NULL)
    821 		return(NULL);
    822 	M_COPY_PKTHDR(n, m); /* just for recvif */
    823 	if (replylen > MHLEN) {
    824 		if (replylen > MCLBYTES)
    825 			 /*
    826 			  * XXX: should we try to allocate more? But MCLBYTES is
    827 			  * probably much larger than IPV6_MMTU...
    828 			  */
    829 			goto bad;
    830 		MCLGET(n, M_DONTWAIT);
    831 		if ((n->m_flags & M_EXT) == 0) {
    832 			goto bad;
    833 		}
    834 	}
    835 	n->m_pkthdr.len = n->m_len = replylen;
    836 
    837 	/* copy mbuf header and IPv6 + Node Information base headers */
    838 	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
    839 	nni6 = (struct icmp6_nodeinfo *)(mtod(n, struct ip6_hdr *) + 1);
    840 	bcopy(mtod(m, caddr_t) + off, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));
    841 
    842 	/* qtype dependent procedure */
    843 	switch (qtype) {
    844 	 case NI_QTYPE_NOOP:
    845 		 nni6->ni_flags = 0;
    846 		 break;
    847 	 case NI_QTYPE_SUPTYPES:
    848 		 goto bad;	/* xxx: to be implemented */
    849 		 break;
    850 	 case NI_QTYPE_FQDN:
    851 		 if (hostnamelen > 255) { /* XXX: rare case, but may happen */
    852 			 printf("ni6_input: "
    853 				"hostname length(%d) is too large for reply\n",
    854 				hostnamelen);
    855 			 goto bad;
    856 		 }
    857 		 fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
    858 						 sizeof(struct ip6_hdr) +
    859 						 sizeof(struct icmp6_nodeinfo));
    860 		 nni6->ni_flags = 0; /* XXX: meaningless TTL */
    861 		 fqdn->ni_fqdn_ttl = 0;	/* ditto. */
    862 		 fqdn->ni_fqdn_namelen = hostnamelen;
    863 		 bcopy(hostname, &fqdn->ni_fqdn_name[0], hostnamelen);
    864 		 break;
    865 	 case NI_QTYPE_NODEADDR:
    866 	 {
    867 		 int lenlim, copied;
    868 
    869 		 if (n->m_flags & M_EXT)
    870 			 lenlim = MCLBYTES - sizeof(struct ip6_hdr) -
    871 				 sizeof(struct icmp6_nodeinfo);
    872 		 else
    873 			 lenlim = MHLEN - sizeof(struct ip6_hdr) -
    874 				 sizeof(struct icmp6_nodeinfo);
    875 		 copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
    876 		 /* XXX: reset mbuf length */
    877 		 n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
    878 			 sizeof(struct icmp6_nodeinfo) + copied;
    879 		 break;
    880 	 }
    881 	 default:
    882 		 break;		/* XXX impossible! */
    883 	}
    884 
    885 	nni6->ni_type = ICMP6_NI_REPLY;
    886 	nni6->ni_code = ICMP6_NI_SUCESS;
    887 	return(n);
    888 
    889   bad:
    890 	if (n)
    891 		m_freem(n);
    892 	return(NULL);
    893 }
    894 #undef hostnamelen
    895 
    896 /*
    897  * calculate the number of addresses to be returned in the node info reply.
    898  */
    899 static int
    900 ni6_addrs(ni6, m, ifpp)
    901 	struct icmp6_nodeinfo *ni6;
    902 	struct mbuf *m;
    903 	struct ifnet **ifpp;
    904 {
    905 	register struct ifnet *ifp;
    906 	register struct in6_ifaddr *ifa6;
    907 	register struct ifaddr *ifa;
    908 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
    909 	int addrs = 0, addrsofif, iffound = 0;
    910 
    911 #ifdef __NetBSD__
    912 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
    913 #else
    914 	for (ifp = ifnet; ifp; ifp = ifp->if_next)
    915 #endif
    916 	{
    917 		addrsofif = 0;
    918 #ifdef __NetBSD__
    919 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
    920 		     ifa = ifa->ifa_list.tqe_next)
    921 #else
    922 		for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
    923 #endif
    924 		{
    925 			if (ifa->ifa_addr->sa_family != AF_INET6)
    926 				continue;
    927 			ifa6 = (struct in6_ifaddr *)ifa;
    928 
    929 			if (!(ni6->ni_flags & NI_NODEADDR_FLAG_ALL) &&
    930 			    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
    931 					       &ifa6->ia_addr.sin6_addr))
    932 				iffound = 1;
    933 
    934 			if (ifa6->ia6_flags & IN6_IFF_ANYCAST)
    935 				continue; /* we need only unicast addresses */
    936 
    937 			if ((ni6->ni_flags & (NI_NODEADDR_FLAG_LINKLOCAL |
    938 					      NI_NODEADDR_FLAG_SITELOCAL |
    939 					      NI_NODEADDR_FLAG_GLOBAL)) == 0)
    940 				continue;
    941 
    942 			/* What do we have to do about ::1? */
    943 			switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
    944 			 case IPV6_ADDR_SCOPE_LINKLOCAL:
    945 				if (ni6->ni_flags & NI_NODEADDR_FLAG_LINKLOCAL)
    946 					addrsofif++;
    947 				break;
    948 			 case IPV6_ADDR_SCOPE_SITELOCAL:
    949 				if (ni6->ni_flags & NI_NODEADDR_FLAG_SITELOCAL)
    950 					addrsofif++;
    951 				break;
    952 			 case IPV6_ADDR_SCOPE_GLOBAL:
    953 				 if (ni6->ni_flags & NI_NODEADDR_FLAG_GLOBAL)
    954 					 addrsofif++;
    955 				 break;
    956 			 default:
    957 				 continue;
    958 			}
    959 		}
    960 		if (iffound) {
    961 			*ifpp = ifp;
    962 			return(addrsofif);
    963 		}
    964 
    965 		addrs += addrsofif;
    966 	}
    967 
    968 	return(addrs);
    969 }
    970 
    971 static int
    972 ni6_store_addrs(ni6, nni6, ifp0, resid)
    973 	struct icmp6_nodeinfo *ni6, *nni6;
    974 	struct ifnet *ifp0;
    975 	int resid;
    976 {
    977 #ifdef __NetBSD__
    978 	register struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&ifnet);
    979 #else
    980 	register struct ifnet *ifp = ifp0 ? ifp0 : ifnet;
    981 #endif
    982 	register struct in6_ifaddr *ifa6;
    983 	register struct ifaddr *ifa;
    984 	int docopy, copied = 0;
    985 	u_char *cp = (u_char *)(nni6 + 1);
    986 
    987 	if (ifp0 == NULL && !(ni6->ni_flags & NI_NODEADDR_FLAG_ALL))
    988 		return(0);	/* needless to copy */
    989 
    990 #ifdef __NetBSD__
    991 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
    992 #else
    993 	for (; ifp; ifp = ifp->if_next)
    994 #endif
    995 	{
    996 #ifdef __NetBSD__
    997 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
    998 		     ifa = ifa->ifa_list.tqe_next)
    999 #else
   1000 		for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
   1001 #endif
   1002 		{
   1003 			docopy = 0;
   1004 
   1005 			if (ifa->ifa_addr->sa_family != AF_INET6)
   1006 				continue;
   1007 			ifa6 = (struct in6_ifaddr *)ifa;
   1008 
   1009 			if (ifa6->ia6_flags & IN6_IFF_ANYCAST)
   1010 				continue; /* we need only unicast addresses */
   1011 
   1012 			/* What do we have to do about ::1? */
   1013 			switch(in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
   1014 			 case IPV6_ADDR_SCOPE_LINKLOCAL:
   1015 				if (ni6->ni_flags & NI_NODEADDR_FLAG_LINKLOCAL)
   1016 					docopy = 1;
   1017 				break;
   1018 			 case IPV6_ADDR_SCOPE_SITELOCAL:
   1019 				if (ni6->ni_flags & NI_NODEADDR_FLAG_SITELOCAL)
   1020 					docopy = 1;
   1021 				break;
   1022 			 case IPV6_ADDR_SCOPE_GLOBAL:
   1023 				 if (ni6->ni_flags & NI_NODEADDR_FLAG_GLOBAL)
   1024 					 docopy = 1;
   1025 				 break;
   1026 			 default:
   1027 				 continue;
   1028 			}
   1029 
   1030 			if (docopy) {
   1031 				if (resid < sizeof(struct in6_addr)) {
   1032 					/*
   1033 					 * We give up much more copy.
   1034 					 * Set the truncate flag and return.
   1035 					 */
   1036 					nni6->ni_flags |=
   1037 						NI_NODEADDR_FLAG_TRUNCATE;
   1038 					return(copied);
   1039 				}
   1040 				bcopy(&ifa6->ia_addr.sin6_addr, cp,
   1041 				      sizeof(struct in6_addr));
   1042 				/* XXX: KAME link-local hack; remove ifindex */
   1043 				if (IN6_IS_ADDR_LINKLOCAL(&ifa6->ia_addr.sin6_addr))
   1044 					((struct in6_addr *)cp)->s6_addr16[1] = 0;
   1045 				cp += sizeof(struct in6_addr);
   1046 				resid -= sizeof(struct in6_addr);
   1047 				copied += sizeof(struct in6_addr);
   1048 			}
   1049 		}
   1050 		if (ifp0)	/* we need search only on the specified IF */
   1051 			break;
   1052 	}
   1053 
   1054 	return(copied);
   1055 }
   1056 
   1057 /*
   1058  * XXX almost dup'ed code with rip6_input.
   1059  */
   1060 static int
   1061 icmp6_rip6_input(mp, off)
   1062 	struct	mbuf **mp;
   1063 	int	off;
   1064 {
   1065 	struct mbuf *m = *mp;
   1066 	register struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   1067 	register struct in6pcb *in6p;
   1068 	struct in6pcb *last = NULL;
   1069 	struct sockaddr_in6 rip6src;
   1070 	struct icmp6_hdr *icmp6;
   1071 	struct mbuf *opts = NULL;
   1072 
   1073 	/* this is assumed to be safe. */
   1074 	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
   1075 
   1076 	bzero(&rip6src, sizeof(rip6src));
   1077 	rip6src.sin6_len = sizeof(struct sockaddr_in6);
   1078 	rip6src.sin6_family = AF_INET6;
   1079 	rip6src.sin6_addr = ip6->ip6_src;
   1080 	if (IN6_IS_SCOPE_LINKLOCAL(&rip6src.sin6_addr))
   1081 		rip6src.sin6_addr.s6_addr16[1] = 0;
   1082 	if (m->m_pkthdr.rcvif) {
   1083 		if (IN6_IS_SCOPE_LINKLOCAL(&rip6src.sin6_addr))
   1084 			rip6src.sin6_scope_id = m->m_pkthdr.rcvif->if_index;
   1085 		else
   1086 			rip6src.sin6_scope_id = 0;
   1087 	} else
   1088 		rip6src.sin6_scope_id = 0;
   1089 
   1090 #if !defined(__FreeBSD__) || __FreeBSD__ < 3
   1091 	for (in6p = rawin6pcb.in6p_next;
   1092 	     in6p != &rawin6pcb; in6p = in6p->in6p_next)
   1093 #else
   1094 	LIST_FOREACH(in6p, &ripcb, inp_list)
   1095 #endif
   1096 	{
   1097 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
   1098 		if ((in6p->inp_vflag & INP_IPV6) == NULL)
   1099 			continue;
   1100 #endif
   1101 		if (in6p->in6p_ip6_nxt != IPPROTO_ICMPV6)
   1102 			continue;
   1103 		if (!IN6_IS_ADDR_ANY(&in6p->in6p_laddr) &&
   1104 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
   1105 			continue;
   1106 		if (!IN6_IS_ADDR_ANY(&in6p->in6p_faddr) &&
   1107 		   !IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
   1108 			continue;
   1109 		if (in6p->in6p_icmp6filt
   1110 		    && ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
   1111 				 in6p->in6p_icmp6filt))
   1112 			continue;
   1113 		if (last) {
   1114 			struct	mbuf *n;
   1115 			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
   1116 				if (last->in6p_flags & IN6P_CONTROLOPTS)
   1117 					ip6_savecontrol(last, &opts, ip6, n);
   1118 				/* strip intermediate headers */
   1119 				m_adj(n, off);
   1120 				if (sbappendaddr(&last->in6p_socket->so_rcv,
   1121 						 (struct sockaddr *)&rip6src,
   1122 						 n, opts) == 0) {
   1123 					/* should notify about lost packet */
   1124 					m_freem(n);
   1125 					if (opts)
   1126 						m_freem(opts);
   1127 				} else
   1128 					sorwakeup(last->in6p_socket);
   1129 				opts = NULL;
   1130 			}
   1131 		}
   1132 		last = in6p;
   1133 	}
   1134 	if (last) {
   1135 		if (last->in6p_flags & IN6P_CONTROLOPTS)
   1136 			ip6_savecontrol(last, &opts, ip6, m);
   1137 		/* strip intermediate headers */
   1138 		m_adj(m, off);
   1139 		if (sbappendaddr(&last->in6p_socket->so_rcv,
   1140 				(struct sockaddr *)&rip6src, m, opts) == 0) {
   1141 			m_freem(m);
   1142 			if (opts)
   1143 				m_freem(opts);
   1144 		} else
   1145 			sorwakeup(last->in6p_socket);
   1146 	} else {
   1147 		m_freem(m);
   1148 		ip6stat.ip6s_delivered--;
   1149 	}
   1150 	return IPPROTO_DONE;
   1151 }
   1152 
   1153 /*
   1154  * Reflect the ip6 packet back to the source.
   1155  * The caller MUST check if the destination is multicast or not.
   1156  * This function is usually called with a unicast destination which
   1157  * can be safely the source of the reply packet. But some exceptions
   1158  * exist(e.g. ECHOREPLY, PATCKET_TOOBIG, "10" in OPTION type).
   1159  * ``off'' points to the icmp6 header, counted from the top of the mbuf.
   1160  */
   1161 void
   1162 icmp6_reflect(m, off)
   1163 	struct	mbuf *m;
   1164 	size_t off;
   1165 {
   1166 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   1167 	struct icmp6_hdr *icmp6;
   1168 	struct in6_ifaddr *ia;
   1169 	struct in6_addr t, *src = 0;
   1170 	int plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
   1171 #ifdef COMPAT_RFC1885
   1172 	int mtu = IPV6_MMTU;
   1173 	struct sockaddr_in6 *sin6 = &icmp6_reflect_rt.ro_dst;
   1174 #endif
   1175 
   1176 	/*
   1177 	 * If there are extra headers between IPv6 and ICMPv6, strip
   1178 	 * off that header first.
   1179 	 */
   1180 	if (off != sizeof(struct ip6_hdr)) {
   1181 		size_t siz;
   1182 
   1183 		/* sanity checks */
   1184 		if (off < sizeof(struct ip6_hdr)) {
   1185 			printf("sanity fail: off=%x, sizeof(ip6)=%x in %s:%d\n",
   1186 			       (unsigned int)off,
   1187 			       (unsigned int)sizeof(struct ip6_hdr),
   1188 			       __FILE__, __LINE__);
   1189 			goto bad;
   1190 		}
   1191 		siz = off - sizeof(struct ip6_hdr);
   1192 		if (plen < siz) {
   1193 			printf("sanity fail: siz=%x, payloadlen=%x in %s:%d\n",
   1194 			       (unsigned int)siz, plen, __FILE__, __LINE__);
   1195 			goto bad;
   1196 		}
   1197 		IP6_EXTHDR_CHECK(m, 0, off, /*nothing*/);
   1198 		IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), /*nothing*/);
   1199 
   1200 		bcopy((caddr_t)ip6,
   1201 			(caddr_t)(mtod(m, u_char *) + siz),
   1202 			sizeof(struct ip6_hdr));
   1203 		m->m_data += siz;
   1204 		m->m_len -= siz;
   1205 		m->m_pkthdr.len -= siz;
   1206 		ip6 = mtod(m, struct ip6_hdr *);
   1207 		ip6->ip6_nxt = IPPROTO_ICMPV6;
   1208 		plen -= siz;
   1209 	}
   1210 
   1211 	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
   1212 
   1213 	t = ip6->ip6_dst;
   1214 	/*
   1215 	 * ip6_input() drops a packet if its src is multicast.
   1216 	 * So, the src is never multicast.
   1217 	 */
   1218 	ip6->ip6_dst = ip6->ip6_src;
   1219 
   1220 	/* XXX hack for link-local addresses */
   1221 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
   1222 		ip6->ip6_dst.s6_addr16[1] =
   1223 			htons(m->m_pkthdr.rcvif->if_index);
   1224 	if (IN6_IS_ADDR_LINKLOCAL(&t))
   1225 		t.s6_addr16[1] = htons(m->m_pkthdr.rcvif->if_index);
   1226 
   1227 #ifdef COMPAT_RFC1885
   1228 	/*
   1229 	 * xxx guess MTU
   1230 	 * RFC 1885 requires that echo reply should be truncated if it
   1231 	 * does not fit in with (return) path MTU, but the description was
   1232 	 * removed in the new spec.
   1233 	 */
   1234 	if (icmp6_reflect_rt.ro_rt == 0 ||
   1235 	    ! (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_dst))) {
   1236 		if (icmp6_reflect_rt.ro_rt) {
   1237 #ifdef __FreeBSD__
   1238 			RTFREE(icmp6_reflect_rt.ro_rt);
   1239 #endif
   1240 #ifdef __bsdi__
   1241 			rtfree(icmp6_reflect_rt.ro_rt);
   1242 #endif
   1243 			icmp6_reflect_rt.ro_rt = 0;
   1244 		}
   1245 		bzero(sin6, sizeof(*sin6));
   1246 		sin6->sin6_family = PF_INET6;
   1247 		sin6->sin6_len = sizeof(struct sockaddr_in6);
   1248 		sin6->sin6_addr = ip6->ip6_dst;
   1249 
   1250 #ifdef __FreeBSD__
   1251 		rtalloc_ign((struct route *)&icmp6_reflect_rt.ro_rt,
   1252 			    RTF_PRCLONING);
   1253 #else
   1254 		rtalloc((struct route *)&icmp6_reflect_rt.ro_rt);
   1255 #endif
   1256 	}
   1257 
   1258 	if (icmp6_reflect_rt.ro_rt == 0)
   1259 		goto bad;
   1260 
   1261 	if ((icmp6_reflect_rt.ro_rt->rt_flags & RTF_HOST)
   1262 	    && mtu < icmp6_reflect_rt.ro_rt->rt_ifp->if_mtu)
   1263 		mtu = icmp6_reflect_rt.ro_rt->rt_rmx.rmx_mtu;
   1264 
   1265 	if (mtu < m->m_pkthdr.len) {
   1266 		plen -= (m->m_pkthdr.len - mtu);
   1267 		m_adj(m, mtu - m->m_pkthdr.len);
   1268 	}
   1269 #endif
   1270 	/*
   1271 	 * If the incoming packet was addressed directly to us(i.e. unicast),
   1272 	 * use dst as the src for the reply.
   1273 	 */
   1274 	for (ia = in6_ifaddr; ia; ia = ia->ia_next)
   1275 		if (IN6_ARE_ADDR_EQUAL(&t, &ia->ia_addr.sin6_addr) &&
   1276 		    (ia->ia6_flags & IN6_IFF_ANYCAST) == 0) {
   1277 			src = &t;
   1278 			break;
   1279 		}
   1280 	if (ia == NULL && IN6_IS_ADDR_LINKLOCAL(&t) && (m->m_flags & M_LOOP)) {
   1281 		/*
   1282 		 * This is the case if the dst is our link-local address
   1283 		 * and the sender is also ourseleves.
   1284 		 */
   1285 		src = &t;
   1286 	}
   1287 
   1288 	if (src == 0)
   1289 		/*
   1290 		 * We have not multicast routing yet. So this case matches
   1291 		 * to our multicast, our anycast or not to our unicast.
   1292 		 * Select a source address which has the same scope.
   1293 		 */
   1294 		if ((ia = in6_ifawithscope(m->m_pkthdr.rcvif, &t)) != 0)
   1295 			src = &IA6_SIN6(ia)->sin6_addr;
   1296 
   1297 	if (src == 0)
   1298 		goto bad;
   1299 
   1300 	ip6->ip6_src = *src;
   1301 
   1302 	ip6->ip6_flow = 0;
   1303 	ip6->ip6_vfc = IPV6_VERSION;
   1304 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   1305 	if (m->m_pkthdr.rcvif) {
   1306 		/* XXX: This may not be the outgoing interface */
   1307 		ip6->ip6_hlim = nd_ifinfo[m->m_pkthdr.rcvif->if_index].chlim;
   1308 	}
   1309 
   1310 	icmp6->icmp6_cksum = 0;
   1311 	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
   1312 					sizeof(struct ip6_hdr), plen);
   1313 
   1314 	/*
   1315 	 * xxx option handling
   1316 	 */
   1317 
   1318 	m->m_flags &= ~(M_BCAST|M_MCAST);
   1319 #ifdef IPSEC
   1320 	m->m_pkthdr.rcvif = NULL;
   1321 #endif /*IPSEC*/
   1322 
   1323 #ifdef COMPAT_RFC1885
   1324 	ip6_output(m, NULL, &icmp6_reflect_rt, 0, NULL);
   1325 #else
   1326 	ip6_output(m, NULL, NULL, 0, NULL);
   1327 #endif
   1328 
   1329 	return;
   1330 
   1331  bad:
   1332 	m_freem(m);
   1333 	return;
   1334 }
   1335 
   1336 void
   1337 icmp6_fasttimo()
   1338 {
   1339 	mld6_fasttimeo();
   1340 }
   1341 
   1342 static void
   1343 icmp6_redirect_diag(level, src6, dst6, tgt6)
   1344 	int level;
   1345 	struct in6_addr *src6;
   1346 	struct in6_addr *dst6;
   1347 	struct in6_addr *tgt6;
   1348 {
   1349 	log(level, "ICMP6 redirect: src=%s dst=%s tgt=%s\n",
   1350 		ip6_sprintf(src6), ip6_sprintf(dst6), ip6_sprintf(tgt6));
   1351 }
   1352 
   1353 void
   1354 icmp6_redirect_input(m, off)
   1355 	register struct mbuf *m;
   1356 	int off;
   1357 {
   1358 	struct ifnet *ifp = m->m_pkthdr.rcvif;
   1359 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
   1360 	struct nd_redirect *nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
   1361 	int icmp6len = ntohs(ip6->ip6_plen);
   1362 	char *lladdr = NULL;
   1363 	int lladdrlen = 0;
   1364 	u_char *redirhdr = NULL;
   1365 	int redirhdrlen = 0;
   1366 	struct rtentry *rt = NULL;
   1367 	int is_router;
   1368 	int is_onlink;
   1369 	struct in6_addr src6 = ip6->ip6_src;
   1370 	struct in6_addr redtgt6 = nd_rd->nd_rd_target;
   1371 	struct in6_addr reddst6 = nd_rd->nd_rd_dst;
   1372 	union nd_opts ndopts;
   1373 
   1374 	if (!m || !ifp)
   1375 		return;
   1376 
   1377 	/* XXX if we are router, we don't update route by icmp6 redirect */
   1378 	if (ip6_forwarding)
   1379 		return;
   1380 	if (!icmp6_rediraccept)
   1381 		return;
   1382 
   1383 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
   1384 		redtgt6.s6_addr16[1] = htons(ifp->if_index);
   1385 	if (IN6_IS_ADDR_LINKLOCAL(&reddst6))
   1386 		reddst6.s6_addr16[1] = htons(ifp->if_index);
   1387 
   1388 	/* validation */
   1389 	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
   1390 		log(LOG_ERR,
   1391 			"ICMP6 redirect sent from %s rejected; "
   1392 			"must be from linklocal\n", ip6_sprintf(&src6));
   1393 		return;
   1394 	}
   1395 	if (ip6->ip6_hlim != 255) {
   1396 		log(LOG_ERR,
   1397 			"ICMP6 redirect sent from %s rejected; "
   1398 			"hlim=%d (must be 255)\n",
   1399 			ip6_sprintf(&src6), ip6->ip6_hlim);
   1400 		return;
   1401 	}
   1402     {
   1403 	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
   1404 	struct sockaddr_in6 sin6;
   1405 	struct in6_addr *gw6;
   1406 
   1407 	bzero(&sin6, sizeof(sin6));
   1408 	sin6.sin6_family = AF_INET6;
   1409 	sin6.sin6_len = sizeof(struct sockaddr_in6);
   1410 	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
   1411 	rt = rtalloc1((struct sockaddr *)&sin6, 0
   1412 #ifdef __FreeBSD__
   1413 		      , 0UL
   1414 #endif
   1415 		      );
   1416 	if (rt) {
   1417 		gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
   1418 		if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
   1419 			icmp6_redirect_diag(LOG_ERR, &src6, &reddst6, &redtgt6);
   1420 			log(LOG_ERR,
   1421 				"ICMP6 redirect sent from %s rejected; "
   1422 				"not equal to gw for src=%s (must be same)\n",
   1423 				ip6_sprintf(&src6), ip6_sprintf(gw6));
   1424 			RTFREE(rt);
   1425 			return;
   1426 		}
   1427 	} else {
   1428 		icmp6_redirect_diag(LOG_ERR, &src6, &reddst6, &redtgt6);
   1429 		log(LOG_ERR,
   1430 			"ICMP6 redirect sent from %s rejected; "
   1431 			"no route found for redirect dst\n",
   1432 			ip6_sprintf(&src6));
   1433 		return;
   1434 	}
   1435 	RTFREE(rt);
   1436 	rt = NULL;
   1437     }
   1438 	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
   1439 		icmp6_redirect_diag(LOG_ERR, &src6, &reddst6, &redtgt6);
   1440 		log(LOG_ERR,
   1441 			"ICMP6 redirect sent from %s rejected; "
   1442 			"redirect dst must be unicast\n",
   1443 			ip6_sprintf(&src6));
   1444 		return;
   1445 	}
   1446 
   1447 	is_router = is_onlink = 0;
   1448 	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
   1449 		is_router = 1;	/* router case */
   1450 	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
   1451 		is_onlink = 1;	/* on-link destination case */
   1452 	if (!is_router && !is_onlink) {
   1453 		icmp6_redirect_diag(LOG_ERR, &src6, &reddst6, &redtgt6);
   1454 		log(LOG_ERR,
   1455 			"ICMP6 redirect sent from %s rejected; "
   1456 			"neither router case nor onlink case\n",
   1457 			ip6_sprintf(&src6));
   1458 		return;
   1459 	}
   1460 	/* validation passed */
   1461 
   1462 	icmp6len -= sizeof(*nd_rd);
   1463 	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
   1464 	if (nd6_options(&ndopts) < 0) {
   1465 		icmp6_redirect_diag(LOG_INFO, &src6, &reddst6, &redtgt6);
   1466 		log(LOG_INFO, "icmp6_redirect_input: "
   1467 			"invalid ND option, rejected\n");
   1468 		return;
   1469 	}
   1470 
   1471 	if (ndopts.nd_opts_tgt_lladdr) {
   1472 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
   1473 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
   1474 	}
   1475 
   1476 	if (ndopts.nd_opts_rh) {
   1477 		redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
   1478 		redirhdr = (u_char *)(ndopts.nd_opts_rh + 1); /* xxx */
   1479 	}
   1480 
   1481 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
   1482 		icmp6_redirect_diag(LOG_INFO, &src6, &reddst6, &redtgt6);
   1483 		log(LOG_INFO,
   1484 			"icmp6_redirect_input: lladdrlen mismatch for %s "
   1485 			"(if %d, icmp6 packet %d)\n",
   1486 			ip6_sprintf(&redtgt6), ifp->if_addrlen, lladdrlen - 2);
   1487 	}
   1488 
   1489 	/* RFC 2461 8.3 */
   1490 	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
   1491 			 is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);
   1492 
   1493 	if (!is_onlink) {	/* better router case. perform rtredirect. */
   1494 		/* perform rtredirect */
   1495 		struct sockaddr_in6 sdst;
   1496 		struct sockaddr_in6 sgw;
   1497 		struct sockaddr_in6 ssrc;
   1498 #ifdef __bsdi__
   1499 		extern int icmp_redirtimeout;	/*XXX*/
   1500 #endif
   1501 
   1502 		bzero(&sdst, sizeof(sdst));
   1503 		bzero(&sgw, sizeof(sgw));
   1504 		bzero(&ssrc, sizeof(ssrc));
   1505 		sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
   1506 		sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
   1507 			sizeof(struct sockaddr_in6);
   1508 		bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
   1509 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
   1510 		bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
   1511 		rtredirect((struct sockaddr *)&sdst, (struct sockaddr *)&sgw,
   1512 			   (struct sockaddr *)NULL, RTF_GATEWAY | RTF_HOST,
   1513 			   (struct sockaddr *)&ssrc,
   1514 #if defined(__FreeBSD__) || defined(__NetBSD__)
   1515 			   (struct rtentry **)NULL
   1516 #elif defined(__bsdi__)
   1517 			   icmp_redirtimeout /*XXX*/
   1518 #endif /*__FreeBSD__, __NetBSD__, __bsdi__*/
   1519 			   );
   1520 	}
   1521 	/* finally update cached route in each socket via pfctlinput */
   1522 	{
   1523 		struct sockaddr_in6 sdst;
   1524 
   1525 		bzero(&sdst, sizeof(sdst));
   1526 		sdst.sin6_family = AF_INET6;
   1527 		sdst.sin6_len = sizeof(struct sockaddr_in6);
   1528 		bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
   1529 		pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
   1530 #ifdef IPSEC
   1531 		key_sa_routechange((struct sockaddr *)&sdst);
   1532 #endif
   1533 	}
   1534 }
   1535 
   1536 void
   1537 icmp6_redirect_output(m0, rt)
   1538 	struct mbuf *m0;
   1539 	struct rtentry *rt;
   1540 {
   1541 	struct ifnet *ifp;	/* my outgoing interface */
   1542 	struct in6_addr *ifp_ll6;
   1543 	struct in6_addr *router_ll6;
   1544 	struct ip6_hdr *sip6;	/* m0 as struct ip6_hdr */
   1545 	struct mbuf *m = NULL;	/* newly allocated one */
   1546 	struct ip6_hdr *ip6;	/* m as struct ip6_hdr */
   1547 	struct nd_redirect *nd_rd;
   1548 	size_t maxlen;
   1549 	u_char *p;
   1550 
   1551 	/* if we are not router, we don't send icmp6 redirect */
   1552 	if (!ip6_forwarding || ip6_accept_rtadv)
   1553 		goto fail;
   1554 
   1555 	/* sanity check */
   1556 	if (!m0 || !rt || !(rt->rt_flags & RTF_UP) || !(ifp = rt->rt_ifp))
   1557 		goto fail;
   1558 
   1559 	/*
   1560 	 * Address check:
   1561 	 *  the source address must identify a neighbor, and
   1562 	 *  the destination address must not be a multicast address
   1563 	 *  [RFC 2461, sec 8.2]
   1564 	 */
   1565 	sip6 = mtod(m0, struct ip6_hdr *);
   1566 	if (nd6_is_addr_neighbor(&sip6->ip6_src, ifp) == 0)
   1567 		goto fail;
   1568 	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
   1569 		goto fail;	/* what should we do here? */
   1570 
   1571 	/* rate limit */
   1572 	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
   1573 		goto fail;
   1574 
   1575 	/*
   1576 	 * Since we are going to append up to 1280 bytes (= IPV6_MMTU),
   1577 	 * we almost always ask for an mbuf cluster for simplicity.
   1578 	 * (MHLEN < IPV6_MMTU is almost always true)
   1579 	 */
   1580 	MGETHDR(m, M_DONTWAIT, MT_HEADER);
   1581 	if (!m)
   1582 		goto fail;
   1583 	if (MHLEN < IPV6_MMTU)
   1584 		MCLGET(m, M_DONTWAIT);
   1585 	maxlen = (m->m_flags & M_EXT) ? MCLBYTES : MHLEN;
   1586 	maxlen = min(IPV6_MMTU, maxlen);
   1587 	/* just for safety */
   1588 	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr))
   1589 		goto fail;
   1590 
   1591 	{
   1592 		/* get ip6 linklocal address for ifp(my outgoing interface). */
   1593 		struct in6_ifaddr *ia = in6ifa_ifpforlinklocal(ifp);
   1594 		if (ia == NULL)
   1595 			goto fail;
   1596 		ifp_ll6 = &ia->ia_addr.sin6_addr;
   1597 	}
   1598 
   1599 	/* get ip6 linklocal address for the router. */
   1600 	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
   1601 		struct sockaddr_in6 *sin6;
   1602 		sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
   1603 		router_ll6 = &sin6->sin6_addr;
   1604 		if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
   1605 			router_ll6 = (struct in6_addr *)NULL;
   1606 	} else
   1607 		router_ll6 = (struct in6_addr *)NULL;
   1608 
   1609 	/* ip6 */
   1610 	ip6 = mtod(m, struct ip6_hdr *);
   1611 	ip6->ip6_flow = 0;
   1612 	ip6->ip6_vfc = IPV6_VERSION;
   1613 	/* ip6->ip6_plen will be set later */
   1614 	ip6->ip6_nxt = IPPROTO_ICMPV6;
   1615 	ip6->ip6_hlim = 255;
   1616 	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
   1617 	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
   1618 	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));
   1619 
   1620 	/* ND Redirect */
   1621 	nd_rd = (struct nd_redirect *)(ip6 + 1);
   1622 	nd_rd->nd_rd_type = ND_REDIRECT;
   1623 	nd_rd->nd_rd_code = 0;
   1624 	nd_rd->nd_rd_reserved = 0;
   1625 	if (rt->rt_flags & RTF_GATEWAY) {
   1626 		/*
   1627 		 * nd_rd->nd_rd_target must be a link-local address in
   1628 		 * better router cases.
   1629 		 */
   1630 		if (!router_ll6)
   1631 			goto fail;
   1632 		bcopy(router_ll6, &nd_rd->nd_rd_target,
   1633 		      sizeof(nd_rd->nd_rd_target));
   1634 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
   1635 		      sizeof(nd_rd->nd_rd_dst));
   1636 	} else {
   1637 		/* make sure redtgt == reddst */
   1638 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
   1639 		      sizeof(nd_rd->nd_rd_target));
   1640 		bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
   1641 		      sizeof(nd_rd->nd_rd_dst));
   1642 	}
   1643 
   1644 	p = (u_char *)(nd_rd + 1);
   1645 
   1646 	if (!router_ll6)
   1647 		goto nolladdropt;
   1648 
   1649     {
   1650 	/* target lladdr option */
   1651 	struct rtentry *rt_router = NULL;
   1652 	int len;
   1653 	struct sockaddr_dl *sdl;
   1654 	struct nd_opt_hdr *nd_opt;
   1655 	char *lladdr;
   1656 
   1657 	rt_router = nd6_lookup(router_ll6, 0, ifp);
   1658 	if (!rt_router)
   1659 		goto nolladdropt;
   1660 	if (!(rt_router->rt_flags & RTF_GATEWAY)
   1661 	 && (rt_router->rt_flags & RTF_LLINFO)
   1662 	 && (rt_router->rt_gateway->sa_family == AF_LINK)
   1663 	 && (sdl = (struct sockaddr_dl *)rt_router->rt_gateway)) {
   1664 		nd_opt = (struct nd_opt_hdr *)p;
   1665 		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
   1666 		len = 2 + ifp->if_addrlen;
   1667 		len = (len + 7) & ~7;	/*round by 8*/
   1668 		nd_opt->nd_opt_len = len >> 3;
   1669 		p += len;
   1670 		lladdr = (char *)(nd_opt + 1);
   1671 		bcopy(LLADDR(sdl), lladdr, ifp->if_addrlen);
   1672 	}
   1673     }
   1674 nolladdropt:;
   1675 
   1676 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
   1677 
   1678 	/* just to be safe */
   1679 	if (m0->m_flags & M_DECRYPTED)
   1680 		goto noredhdropt;
   1681 
   1682     {
   1683 	/* redirected header option */
   1684 	int len;
   1685 	struct nd_opt_rd_hdr *nd_opt_rh;
   1686 
   1687 	/*
   1688 	 * compute the maximum size for icmp6 redirect header option.
   1689 	 * XXX room for auth header?
   1690 	 */
   1691 	len = maxlen - (p - (u_char *)ip6);
   1692 	len &= ~7;
   1693 
   1694 	/* This is just for simplicity. */
   1695 	if (m0->m_pkthdr.len != m0->m_len) {
   1696 		if (m0->m_next) {
   1697 			m_freem(m0->m_next);
   1698 			m0->m_next = NULL;
   1699 		}
   1700 		m0->m_pkthdr.len = m0->m_len;
   1701 	}
   1702 
   1703 	/*
   1704 	 * Redirected header option spec (RFC2461 4.6.3) talks nothing
   1705 	 * about padding/trancate rule for the original IP packet.
   1706 	 * From the discussion on IPv6imp in Feb 1999, the consensus was:
   1707 	 * - "attach as much as possible" is the goal
   1708 	 * - pad if not aligned (original size can be guessed by original
   1709 	 *   ip6 header)
   1710 	 * Following code adds the padding if it is simple enough,
   1711 	 * and truncates if not.
   1712 	 */
   1713 	if (m0->m_next || m0->m_pkthdr.len != m0->m_len)
   1714 		panic("assumption failed in %s:%d\n", __FILE__, __LINE__);
   1715 
   1716 	if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
   1717 		/* not enough room, truncate */
   1718 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
   1719 	} else {
   1720 		/* enough room, pad or truncate */
   1721 		size_t extra;
   1722 
   1723 		extra = m0->m_pkthdr.len % 8;
   1724 		if (extra) {
   1725 			/* pad if easy enough, truncate if not */
   1726 			if (8 - extra <= M_TRAILINGSPACE(m0)) {
   1727 				/* pad */
   1728 				m0->m_len += (8 - extra);
   1729 				m0->m_pkthdr.len += (8 - extra);
   1730 			} else {
   1731 				/* truncate */
   1732 				m0->m_pkthdr.len -= extra;
   1733 				m0->m_len -= extra;
   1734 			}
   1735 		}
   1736 		len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
   1737 		m0->m_pkthdr.len = m0->m_len = len - sizeof(*nd_opt_rh);
   1738 	}
   1739 
   1740 	nd_opt_rh = (struct nd_opt_rd_hdr *)p;
   1741 	bzero(nd_opt_rh, sizeof(*nd_opt_rh));
   1742 	nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
   1743 	nd_opt_rh->nd_opt_rh_len = len >> 3;
   1744 	p += sizeof(*nd_opt_rh);
   1745 	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;
   1746 
   1747 	/* connect m0 to m */
   1748 	m->m_next = m0;
   1749 	m->m_pkthdr.len = m->m_len + m0->m_len;
   1750     }
   1751 noredhdropt:;
   1752 
   1753 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_src))
   1754 		sip6->ip6_src.s6_addr16[1] = 0;
   1755 	if (IN6_IS_ADDR_LINKLOCAL(&sip6->ip6_dst))
   1756 		sip6->ip6_dst.s6_addr16[1] = 0;
   1757 #if 0
   1758 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
   1759 		ip6->ip6_src.s6_addr16[1] = 0;
   1760 	if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst))
   1761 		ip6->ip6_dst.s6_addr16[1] = 0;
   1762 #endif
   1763 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_target))
   1764 		nd_rd->nd_rd_target.s6_addr16[1] = 0;
   1765 	if (IN6_IS_ADDR_LINKLOCAL(&nd_rd->nd_rd_dst))
   1766 		nd_rd->nd_rd_dst.s6_addr16[1] = 0;
   1767 
   1768 	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
   1769 
   1770 	nd_rd->nd_rd_cksum = 0;
   1771 	nd_rd->nd_rd_cksum
   1772 		= in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), ntohs(ip6->ip6_plen));
   1773 
   1774 	/* send the packet to outside... */
   1775 #ifdef IPSEC
   1776 	m->m_pkthdr.rcvif = NULL;
   1777 #endif /*IPSEC*/
   1778 	ip6_output(m, NULL, NULL, 0, NULL);
   1779 	icmp6stat.icp6s_outhist[ND_REDIRECT]++;
   1780 
   1781 	return;
   1782 
   1783 fail:
   1784 	if (m)
   1785 		m_freem(m);
   1786 	if (m0)
   1787 		m_freem(m0);
   1788 }
   1789 
   1790 /*
   1791  * ICMPv6 socket option processing.
   1792  */
   1793 int
   1794 icmp6_ctloutput(op, so, level, optname, mp)
   1795 	int op;
   1796 	struct socket *so;
   1797 	int level, optname;
   1798 	struct mbuf **mp;
   1799 {
   1800 	register struct in6pcb *in6p = sotoin6pcb(so);
   1801 	register struct mbuf *m = *mp;
   1802 	int error = 0;
   1803 
   1804 	if (level != IPPROTO_ICMPV6) {
   1805 		error = EINVAL;
   1806 		if (op == PRCO_SETOPT && m)
   1807 			(void)m_free(m);
   1808 	} else switch(op) {
   1809 	 case PRCO_SETOPT:
   1810 		 switch (optname) {
   1811 		  case ICMP6_FILTER:
   1812 		  {
   1813 			  struct icmp6_filter *p;
   1814 
   1815 			  p = mtod(m, struct icmp6_filter *);
   1816 			  if (!p || !in6p->in6p_icmp6filt) {
   1817 				  error = EINVAL;
   1818 				  break;
   1819 			  }
   1820 			  bcopy(p, in6p->in6p_icmp6filt,
   1821 				sizeof(struct icmp6_filter));
   1822 			  error = 0;
   1823 			  break;
   1824 		  }
   1825 
   1826 		  default:
   1827 			  error = ENOPROTOOPT;
   1828 			  break;
   1829 		 }
   1830 		 if (m)
   1831 			 (void)m_free(m);
   1832 		 break;
   1833 
   1834 	 case PRCO_GETOPT:
   1835 		 switch (optname) {
   1836 		  case ICMP6_FILTER:
   1837 		  {
   1838 			  struct icmp6_filter *p;
   1839 
   1840 			  p = mtod(m, struct icmp6_filter *);
   1841 			  if (!p || !in6p->in6p_icmp6filt) {
   1842 				  error = EINVAL;
   1843 				  break;
   1844 			  }
   1845 			  bcopy(in6p->in6p_icmp6filt, p,
   1846 				sizeof(struct icmp6_filter));
   1847 			  error = 0;
   1848 			  break;
   1849 		  }
   1850 
   1851 		  default:
   1852 			  error = ENOPROTOOPT;
   1853 			  break;
   1854 		 }
   1855 		 break;
   1856 	}
   1857 
   1858 	return(error);
   1859 }
   1860 
   1861 /*
   1862  * Perform rate limit check.
   1863  * Returns 0 if it is okay to send the icmp6 packet.
   1864  * Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
   1865  * limitation.
   1866  *
   1867  * XXX per-destination/type check necessary?
   1868  */
   1869 static int
   1870 icmp6_ratelimit(dst, type, code)
   1871 	const struct in6_addr *dst;	/* not used at this moment */
   1872 	const int type;			/* not used at this moment */
   1873 	const int code;			/* not used at this moment */
   1874 {
   1875 	struct timeval tp;
   1876 	long sec_diff, usec_diff;
   1877 
   1878 	/* If we are not doing rate limitation, it is always okay to send */
   1879 	if (!icmp6errratelim)
   1880 		return 0;
   1881 
   1882 #if defined(__FreeBSD__) && __FreeBSD__ >= 3
   1883 	microtime(&tp);
   1884 	tp.tv_sec = time_second;
   1885 #else
   1886 	tp = time;
   1887 #endif
   1888 	if (tp.tv_sec < icmp6_nextsend.tv_sec
   1889 	 || (tp.tv_sec == icmp6_nextsend.tv_sec
   1890 	  && tp.tv_usec < icmp6_nextsend.tv_usec)) {
   1891 		/* The packet is subject to rate limit */
   1892 		return 1;
   1893 	}
   1894 	sec_diff = icmp6errratelim / 1000000;
   1895 	usec_diff = icmp6errratelim % 1000000;
   1896 	icmp6_nextsend.tv_sec = tp.tv_sec + sec_diff;
   1897 	if ((tp.tv_usec = tp.tv_usec + usec_diff) >= 1000000) {
   1898 		icmp6_nextsend.tv_sec++;
   1899 		icmp6_nextsend.tv_usec -= 1000000;
   1900 	}
   1901 
   1902 	/* it is okay to send this */
   1903 	return 0;
   1904 }
   1905 
   1906 #ifdef __NetBSD__
   1907 static struct rtentry *
   1908 icmp6_mtudisc_clone(dst)
   1909 	struct sockaddr *dst;
   1910 {
   1911 	struct rtentry *rt;
   1912 	int    error;
   1913 
   1914 	rt = rtalloc1(dst, 1);
   1915 	if (rt == 0)
   1916 		return NULL;
   1917 
   1918 	/* If we didn't get a host route, allocate one */
   1919 	if ((rt->rt_flags & RTF_HOST) == 0) {
   1920 		struct rtentry *nrt;
   1921 
   1922 		error = rtrequest((int) RTM_ADD, dst,
   1923 		    (struct sockaddr *) rt->rt_gateway,
   1924 		    (struct sockaddr *) 0,
   1925 		    RTF_GATEWAY | RTF_HOST | RTF_DYNAMIC, &nrt);
   1926 		if (error) {
   1927 			rtfree(rt);
   1928 			rtfree(nrt);
   1929 			return NULL;
   1930 		}
   1931 		nrt->rt_rmx = rt->rt_rmx;
   1932 		rtfree(rt);
   1933 		rt = nrt;
   1934 	}
   1935 	error = rt_timer_add(rt, icmp6_mtudisc_timeout,
   1936 			icmp6_mtudisc_timeout_q);
   1937 	if (error) {
   1938 		rtfree(rt);
   1939 		return NULL;
   1940 	}
   1941 
   1942 	return rt;	/* caller need to call rtfree() */
   1943 }
   1944 
   1945 static void
   1946 icmp6_mtudisc_timeout(rt, r)
   1947 	struct rtentry *rt;
   1948 	struct rttimer *r;
   1949 {
   1950 	if (rt == NULL)
   1951 		panic("icmp6_mtudisc_timeout: bad route to timeout");
   1952 	if ((rt->rt_flags & (RTF_DYNAMIC | RTF_HOST)) ==
   1953 	    (RTF_DYNAMIC | RTF_HOST)) {
   1954 		rtrequest((int) RTM_DELETE, (struct sockaddr *)rt_key(rt),
   1955 		    rt->rt_gateway, rt_mask(rt), rt->rt_flags, 0);
   1956 	} else {
   1957 		if ((rt->rt_rmx.rmx_locks & RTV_MTU) == 0) {
   1958 			rt->rt_rmx.rmx_mtu = 0;
   1959 		}
   1960 	}
   1961 }
   1962 #endif /*__NetBSD__*/
   1963 
   1964 #ifdef __bsdi__
   1965 void
   1966 icmp6_mtuexpire(rt, rtt)
   1967 	struct rtentry *rt;
   1968 	struct rttimer *rtt;
   1969 {
   1970 	rt->rt_flags |= RTF_PROBEMTU;
   1971 	Free(rtt);
   1972 }
   1973 
   1974 int *icmp6_sysvars[] = ICMPV6CTL_VARS;
   1975 
   1976 int
   1977 icmp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
   1978 	int *name;
   1979 	u_int namelen;
   1980 	void *oldp;
   1981 	size_t *oldlenp;
   1982 	void *newp;
   1983 	size_t newlen;
   1984 {
   1985 	if (name[0] >= ICMPV6CTL_MAXID)
   1986 		return (EOPNOTSUPP);
   1987 	switch (name[0]) {
   1988 #if 0
   1989 	ICMPV6CTL_ND6_PRUNE:
   1990 	ICMPV6CTL_ND6_DELAY:
   1991 	ICMPV6CTL_ND6_UMAXTRIES:
   1992 	ICMPV6CTL_ND6_MMAXTRIES:
   1993 	ICMPV6CTL_ND6_USELOOPBACK:
   1994 	ICMPV6CTL_ND6_PROXYALL:
   1995 		/* need to check the value. */
   1996 #endif
   1997 	case ICMPV6CTL_STATS:
   1998 		return sysctl_rdtrunc(oldp, oldlenp, newp, &icmp6stat,
   1999 		    sizeof(icmp6stat));
   2000 
   2001 	default:
   2002 		return (sysctl_int_arr(icmp6_sysvars, name, namelen,
   2003 		    oldp, oldlenp, newp, newlen));
   2004 	}
   2005 }
   2006 #endif /*__bsdi__*/
   2007 
   2008 #ifdef __NetBSD__
   2009 #include <vm/vm.h>
   2010 #include <sys/sysctl.h>
   2011 int
   2012 icmp6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
   2013 	int *name;
   2014 	u_int namelen;
   2015 	void *oldp;
   2016 	size_t *oldlenp;
   2017 	void *newp;
   2018 	size_t newlen;
   2019 {
   2020 
   2021 	/* All sysctl names at this level are terminal. */
   2022 	if (namelen != 1)
   2023 		return ENOTDIR;
   2024 
   2025 	switch (name[0]) {
   2026 
   2027 	case ICMPV6CTL_REDIRACCEPT:
   2028 		return sysctl_int(oldp, oldlenp, newp, newlen,
   2029 				&icmp6_rediraccept);
   2030 	case ICMPV6CTL_REDIRTIMEOUT:
   2031 		return sysctl_int(oldp, oldlenp, newp, newlen,
   2032 				&icmp6_redirtimeout);
   2033 	case ICMPV6CTL_STATS:
   2034 		return sysctl_rdstruct(oldp, oldlenp, newp,
   2035 				&icmp6stat, sizeof(icmp6stat));
   2036 	case ICMPV6CTL_ERRRATELIMIT:
   2037 		return sysctl_int(oldp, oldlenp, newp, newlen,
   2038 				  &icmp6errratelim);
   2039 	case ICMPV6CTL_ND6_PRUNE:
   2040 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_prune);
   2041 	case ICMPV6CTL_ND6_DELAY:
   2042 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_delay);
   2043 	case ICMPV6CTL_ND6_UMAXTRIES:
   2044 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_umaxtries);
   2045 	case ICMPV6CTL_ND6_MMAXTRIES:
   2046 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_mmaxtries);
   2047 	case ICMPV6CTL_ND6_USELOOPBACK:
   2048 		return sysctl_int(oldp, oldlenp, newp, newlen,
   2049 				&nd6_useloopback);
   2050 	case ICMPV6CTL_ND6_PROXYALL:
   2051 		return sysctl_int(oldp, oldlenp, newp, newlen, &nd6_proxyall);
   2052 	default:
   2053 		return ENOPROTOOPT;
   2054 	}
   2055 	/* NOTREACHED */
   2056 }
   2057 #endif /* __NetBSD__ */
   2058