icmp6.c
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icmp6.c
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	/*-
	* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of the project nor the names of its contributors
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*
	* $KAME: icmp6.c,v 1.211 2001/04/04 05:56:20 itojun Exp $
	*/

	/*-
	* Copyright (c) 1982, 1986, 1988, 1993
	* The Regents of the University of California. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 4. Neither the name of the University nor the names of its contributors
	* may be used to endorse or promote products derived from this software
	* without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	* SUCH DAMAGE.
	*
	* @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
	*/

	#include <sys/cdefs.h>
	__FBSDID("$FreeBSD$");

	#include "opt_inet.h"
	#include "opt_inet6.h"
	#include "opt_ipsec.h"

	#include <sys/param.h>
	#include <sys/domain.h>
	#include <sys/jail.h>
	#include <sys/kernel.h>
	#include <sys/lock.h>
	#include <sys/malloc.h>
	#include <sys/mbuf.h>
	#include <sys/protosw.h>
	#include <sys/signalvar.h>
	#include <sys/socket.h>
	#include <sys/socketvar.h>
	#include <sys/sx.h>
	#include <sys/syslog.h>
	#include <sys/systm.h>
	#include <sys/time.h>
	#include <sys/vimage.h>

	#include <net/if.h>
	#include <net/if_dl.h>
	#include <net/if_llatbl.h>
	#include <net/if_types.h>
	#include <net/route.h>
	#include <net/vnet.h>

	#include <netinet/in.h>
	#include <netinet/in_pcb.h>
	#include <netinet/in_var.h>
	#include <netinet/ip6.h>
	#include <netinet/icmp6.h>
	#include <netinet/tcp_var.h>
	#include <netinet/vinet.h>

	#include <netinet6/in6_ifattach.h>
	#include <netinet6/in6_pcb.h>
	#include <netinet6/ip6protosw.h>
	#include <netinet6/ip6_var.h>
	#include <netinet6/scope6_var.h>
	#include <netinet6/mld6_var.h>
	#include <netinet6/nd6.h>
	#include <netinet6/vinet6.h>

	#ifdef IPSEC
	#include <netipsec/ipsec.h>
	#include <netipsec/key.h>
	#endif

	extern struct domain inet6domain;

	#ifdef VIMAGE_GLOBALS
	extern struct inpcbinfo ripcbinfo;
	extern struct inpcbhead ripcb;
	extern int icmp6errppslim;
	extern int icmp6_nodeinfo;

	struct icmp6stat icmp6stat;
	static int icmp6errpps_count;
	static struct timeval icmp6errppslim_last;
	#endif

	static void icmp6_errcount(struct icmp6errstat *, int, int);
	static int icmp6_rip6_input(struct mbuf **, int);
	static int icmp6_ratelimit(const struct in6_addr *, const int, const int);
	static const char icmp6_redirect_diag __P((struct in6_addr ,
	struct in6_addr , struct in6_addr ));
	static struct mbuf ni6_input(struct mbuf , int);
	static struct mbuf ni6_nametodns(const char , int, int);
	static int ni6_dnsmatch(const char , int, const char , int);
	static int ni6_addrs __P((struct icmp6_nodeinfo , struct mbuf ,
	struct ifnet *, struct in6_addr ));
	static int ni6_store_addrs __P((struct icmp6_nodeinfo , struct icmp6_nodeinfo ,
	struct ifnet *, int));
	static int icmp6_notify_error(struct mbuf **, int, int, int);


	void
	icmp6_init(void)
	{
	INIT_VNET_INET6(curvnet);

	V_icmp6errpps_count = 0;
	}

	static void
	icmp6_errcount(struct icmp6errstat *stat, int type, int code)
	{
	switch (type) {
	case ICMP6_DST_UNREACH:
	switch (code) {
	case ICMP6_DST_UNREACH_NOROUTE:
	stat->icp6errs_dst_unreach_noroute++;
	return;
	case ICMP6_DST_UNREACH_ADMIN:
	stat->icp6errs_dst_unreach_admin++;
	return;
	case ICMP6_DST_UNREACH_BEYONDSCOPE:
	stat->icp6errs_dst_unreach_beyondscope++;
	return;
	case ICMP6_DST_UNREACH_ADDR:
	stat->icp6errs_dst_unreach_addr++;
	return;
	case ICMP6_DST_UNREACH_NOPORT:
	stat->icp6errs_dst_unreach_noport++;
	return;
	}
	break;
	case ICMP6_PACKET_TOO_BIG:
	stat->icp6errs_packet_too_big++;
	return;
	case ICMP6_TIME_EXCEEDED:
	switch (code) {
	case ICMP6_TIME_EXCEED_TRANSIT:
	stat->icp6errs_time_exceed_transit++;
	return;
	case ICMP6_TIME_EXCEED_REASSEMBLY:
	stat->icp6errs_time_exceed_reassembly++;
	return;
	}
	break;
	case ICMP6_PARAM_PROB:
	switch (code) {
	case ICMP6_PARAMPROB_HEADER:
	stat->icp6errs_paramprob_header++;
	return;
	case ICMP6_PARAMPROB_NEXTHEADER:
	stat->icp6errs_paramprob_nextheader++;
	return;
	case ICMP6_PARAMPROB_OPTION:
	stat->icp6errs_paramprob_option++;
	return;
	}
	break;
	case ND_REDIRECT:
	stat->icp6errs_redirect++;
	return;
	}
	stat->icp6errs_unknown++;
	}

	/*
	* A wrapper function for icmp6_error() necessary when the erroneous packet
	* may not contain enough scope zone information.
	*/
	void
	icmp6_error2(struct mbuf *m, int type, int code, int param,
	struct ifnet *ifp)
	{
	INIT_VNET_INET6(curvnet);
	struct ip6_hdr *ip6;

	if (ifp == NULL)
	return;

	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
	#else
	if (m->m_len < sizeof(struct ip6_hdr)) {
	m = m_pullup(m, sizeof(struct ip6_hdr));
	if (m == NULL)
	return;
	}
	#endif

	ip6 = mtod(m, struct ip6_hdr *);

	if (in6_setscope(&ip6->ip6_src, ifp, NULL) != 0)
	return;
	if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
	return;

	icmp6_error(m, type, code, param);
	}

	/*
	* Generate an error packet of type error in response to bad IP6 packet.
	*/
	void
	icmp6_error(struct mbuf *m, int type, int code, int param)
	{
	INIT_VNET_INET6(curvnet);
	struct ip6_hdr oip6, nip6;
	struct icmp6_hdr *icmp6;
	u_int preplen;
	int off;
	int nxt;

	ICMP6STAT_INC(icp6s_error);

	/* count per-type-code statistics */
	icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, type, code);

	#ifdef M_DECRYPTED /not openbsd/
	if (m->m_flags & M_DECRYPTED) {
	ICMP6STAT_INC(icp6s_canterror);
	goto freeit;
	}
	#endif

	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), );
	#else
	if (m->m_len < sizeof(struct ip6_hdr)) {
	m = m_pullup(m, sizeof(struct ip6_hdr));
	if (m == NULL)
	return;
	}
	#endif
	oip6 = mtod(m, struct ip6_hdr *);

	/*
	* If the destination address of the erroneous packet is a multicast
	* address, or the packet was sent using link-layer multicast,
	* we should basically suppress sending an error (RFC 2463, Section
	* 2.4).
	* We have two exceptions (the item e.2 in that section):
	* - the Pakcet Too Big message can be sent for path MTU discovery.
	* - the Parameter Problem Message that can be allowed an icmp6 error
	* in the option type field. This check has been done in
	* ip6_unknown_opt(), so we can just check the type and code.
	*/
	if ((m->m_flags & (M_BCAST\|M_MCAST) \|\|
	IN6_IS_ADDR_MULTICAST(&oip6->ip6_dst)) &&
	(type != ICMP6_PACKET_TOO_BIG &&
	(type != ICMP6_PARAM_PROB \|\|
	code != ICMP6_PARAMPROB_OPTION)))
	goto freeit;

	/*
	* RFC 2463, 2.4 (e.5): source address check.
	* XXX: the case of anycast source?
	*/
	if (IN6_IS_ADDR_UNSPECIFIED(&oip6->ip6_src) \|\|
	IN6_IS_ADDR_MULTICAST(&oip6->ip6_src))
	goto freeit;

	/*
	* If we are about to send ICMPv6 against ICMPv6 error/redirect,
	* don't do it.
	*/
	nxt = -1;
	off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
	if (off >= 0 && nxt == IPPROTO_ICMPV6) {
	struct icmp6_hdr *icp;

	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
	icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
	#else
	IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
	sizeof(*icp));
	if (icp == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return;
	}
	#endif
	if (icp->icmp6_type < ICMP6_ECHO_REQUEST \|\|
	icp->icmp6_type == ND_REDIRECT) {
	/*
	* ICMPv6 error
	* Special case: for redirect (which is
	* informational) we must not send icmp6 error.
	*/
	ICMP6STAT_INC(icp6s_canterror);
	goto freeit;
	} else {
	/* ICMPv6 informational - send the error */
	}
	} else {
	/* non-ICMPv6 - send the error */
	}

	oip6 = mtod(m, struct ip6_hdr ); / adjust pointer */

	/* Finally, do rate limitation check. */
	if (icmp6_ratelimit(&oip6->ip6_src, type, code)) {
	ICMP6STAT_INC(icp6s_toofreq);
	goto freeit;
	}

	/*
	* OK, ICMP6 can be generated.
	*/

	if (m->m_pkthdr.len >= ICMPV6_PLD_MAXLEN)
	m_adj(m, ICMPV6_PLD_MAXLEN - m->m_pkthdr.len);

	preplen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
	M_PREPEND(m, preplen, M_DONTWAIT);
	if (m && m->m_len < preplen)
	m = m_pullup(m, preplen);
	if (m == NULL) {
	nd6log((LOG_DEBUG, "ENOBUFS in icmp6_error %d\n", __LINE__));
	return;
	}

	nip6 = mtod(m, struct ip6_hdr *);
	nip6->ip6_src = oip6->ip6_src;
	nip6->ip6_dst = oip6->ip6_dst;

	in6_clearscope(&oip6->ip6_src);
	in6_clearscope(&oip6->ip6_dst);

	icmp6 = (struct icmp6_hdr *)(nip6 + 1);
	icmp6->icmp6_type = type;
	icmp6->icmp6_code = code;
	icmp6->icmp6_pptr = htonl((u_int32_t)param);

	/*
	* icmp6_reflect() is designed to be in the input path.
	* icmp6_error() can be called from both input and output path,
	* and if we are in output path rcvif could contain bogus value.
	* clear m->m_pkthdr.rcvif for safety, we should have enough scope
	* information in ip header (nip6).
	*/
	m->m_pkthdr.rcvif = NULL;

	ICMP6STAT_INC(icp6s_outhist[type]);
	icmp6_reflect(m, sizeof(struct ip6_hdr)); /* header order: IPv6 - ICMPv6 */

	return;

	freeit:
	/*
	* If we can't tell whether or not we can generate ICMP6, free it.
	*/
	m_freem(m);
	}

	/*
	* Process a received ICMP6 message.
	*/
	int
	icmp6_input(struct mbuf *mp, int offp, int proto)
	{
	INIT_VNET_INET6(curvnet);
	struct mbuf m = mp, *n;
	struct ifnet *ifp;
	struct ip6_hdr ip6, nip6;
	struct icmp6_hdr icmp6, nicmp6;
	int off = *offp;
	int icmp6len = m->m_pkthdr.len - *offp;
	int code, sum, noff;
	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];

	ifp = m->m_pkthdr.rcvif;

	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_hdr), IPPROTO_DONE);
	/* m might change if M_LOOP. So, call mtod after this */
	#endif

	/*
	* Locate icmp6 structure in mbuf, and check
	* that not corrupted and of at least minimum length
	*/

	ip6 = mtod(m, struct ip6_hdr *);
	if (icmp6len < sizeof(struct icmp6_hdr)) {
	ICMP6STAT_INC(icp6s_tooshort);
	goto freeit;
	}

	/*
	* Check multicast group membership.
	* Note: SSM filters are not applied for ICMPv6 traffic.
	*/
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
	struct in6_multi *inm;

	inm = in6m_lookup(ifp, &ip6->ip6_dst);
	if (inm == NULL) {
	IP6STAT_INC(ip6s_notmember);
	in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
	goto freeit;
	}
	}

	/*
	* calculate the checksum
	*/
	#ifndef PULLDOWN_TEST
	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
	#else
	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr , m, off, sizeof(icmp6));
	if (icmp6 == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return IPPROTO_DONE;
	}
	#endif
	code = icmp6->icmp6_code;

	if ((sum = in6_cksum(m, IPPROTO_ICMPV6, off, icmp6len)) != 0) {
	nd6log((LOG_ERR,
	"ICMP6 checksum error(%d\|%x) %s\n",
	icmp6->icmp6_type, sum,
	ip6_sprintf(ip6bufs, &ip6->ip6_src)));
	ICMP6STAT_INC(icp6s_checksum);
	goto freeit;
	}

	if (faithprefix_p != NULL && (*faithprefix_p)(&ip6->ip6_dst)) {
	/*
	* Deliver very specific ICMP6 type only.
	* This is important to deliver TOOBIG. Otherwise PMTUD
	* will not work.
	*/
	switch (icmp6->icmp6_type) {
	case ICMP6_DST_UNREACH:
	case ICMP6_PACKET_TOO_BIG:
	case ICMP6_TIME_EXCEEDED:
	break;
	default:
	goto freeit;
	}
	}

	ICMP6STAT_INC(icp6s_inhist[icmp6->icmp6_type]);
	icmp6_ifstat_inc(ifp, ifs6_in_msg);
	if (icmp6->icmp6_type < ICMP6_INFOMSG_MASK)
	icmp6_ifstat_inc(ifp, ifs6_in_error);

	switch (icmp6->icmp6_type) {
	case ICMP6_DST_UNREACH:
	icmp6_ifstat_inc(ifp, ifs6_in_dstunreach);
	switch (code) {
	case ICMP6_DST_UNREACH_NOROUTE:
	code = PRC_UNREACH_NET;
	break;
	case ICMP6_DST_UNREACH_ADMIN:
	icmp6_ifstat_inc(ifp, ifs6_in_adminprohib);
	code = PRC_UNREACH_PROTOCOL; /* is this a good code? */
	break;
	case ICMP6_DST_UNREACH_ADDR:
	code = PRC_HOSTDEAD;
	break;
	case ICMP6_DST_UNREACH_BEYONDSCOPE:
	/* I mean "source address was incorrect." */
	code = PRC_PARAMPROB;
	break;
	case ICMP6_DST_UNREACH_NOPORT:
	code = PRC_UNREACH_PORT;
	break;
	default:
	goto badcode;
	}
	goto deliver;
	break;

	case ICMP6_PACKET_TOO_BIG:
	icmp6_ifstat_inc(ifp, ifs6_in_pkttoobig);

	/* validation is made in icmp6_mtudisc_update */

	code = PRC_MSGSIZE;

	/*
	* Updating the path MTU will be done after examining
	* intermediate extension headers.
	*/
	goto deliver;
	break;

	case ICMP6_TIME_EXCEEDED:
	icmp6_ifstat_inc(ifp, ifs6_in_timeexceed);
	switch (code) {
	case ICMP6_TIME_EXCEED_TRANSIT:
	code = PRC_TIMXCEED_INTRANS;
	break;
	case ICMP6_TIME_EXCEED_REASSEMBLY:
	code = PRC_TIMXCEED_REASS;
	break;
	default:
	goto badcode;
	}
	goto deliver;
	break;

	case ICMP6_PARAM_PROB:
	icmp6_ifstat_inc(ifp, ifs6_in_paramprob);
	switch (code) {
	case ICMP6_PARAMPROB_NEXTHEADER:
	code = PRC_UNREACH_PROTOCOL;
	break;
	case ICMP6_PARAMPROB_HEADER:
	case ICMP6_PARAMPROB_OPTION:
	code = PRC_PARAMPROB;
	break;
	default:
	goto badcode;
	}
	goto deliver;
	break;

	case ICMP6_ECHO_REQUEST:
	icmp6_ifstat_inc(ifp, ifs6_in_echo);
	if (code != 0)
	goto badcode;
	if ((n = m_copy(m, 0, M_COPYALL)) == NULL) {
	/* Give up remote */
	break;
	}
	if ((n->m_flags & M_EXT) != 0
	\|\| n->m_len < off + sizeof(struct icmp6_hdr)) {
	struct mbuf *n0 = n;
	const int maxlen = sizeof(nip6) + sizeof(nicmp6);
	int n0len;

	MGETHDR(n, M_DONTWAIT, n0->m_type);
	n0len = n0->m_pkthdr.len; /* save for use below */
	if (n)
	M_MOVE_PKTHDR(n, n0);
	if (n && maxlen >= MHLEN) {
	MCLGET(n, M_DONTWAIT);
	if ((n->m_flags & M_EXT) == 0) {
	m_free(n);
	n = NULL;
	}
	}
	if (n == NULL) {
	/* Give up remote */
	m_freem(n0);
	break;
	}
	/*
	* Copy IPv6 and ICMPv6 only.
	*/
	nip6 = mtod(n, struct ip6_hdr *);
	bcopy(ip6, nip6, sizeof(struct ip6_hdr));
	nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
	bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
	noff = sizeof(struct ip6_hdr);
	/* new mbuf contains only ipv6+icmpv6 headers */
	n->m_len = noff + sizeof(struct icmp6_hdr);
	/*
	* Adjust mbuf. ip6_plen will be adjusted in
	* ip6_output().
	*/
	m_adj(n0, off + sizeof(struct icmp6_hdr));
	/* recalculate complete packet size */
	n->m_pkthdr.len = n0len + (noff - off);
	n->m_next = n0;
	} else {
	nip6 = mtod(n, struct ip6_hdr *);
	IP6_EXTHDR_GET(nicmp6, struct icmp6_hdr *, n, off,
	sizeof(*nicmp6));
	noff = off;
	}
	nicmp6->icmp6_type = ICMP6_ECHO_REPLY;
	nicmp6->icmp6_code = 0;
	if (n) {
	ICMP6STAT_INC(icp6s_reflect);
	ICMP6STAT_INC(icp6s_outhist[ICMP6_ECHO_REPLY]);
	icmp6_reflect(n, noff);
	}
	break;

	case ICMP6_ECHO_REPLY:
	icmp6_ifstat_inc(ifp, ifs6_in_echoreply);
	if (code != 0)
	goto badcode;
	break;

	case MLD_LISTENER_QUERY:
	case MLD_LISTENER_REPORT:
	case MLD_LISTENER_DONE:
	case MLDV2_LISTENER_REPORT:
	/*
	* Drop MLD traffic which is not link-local, has a hop limit
	* of greater than 1 hop, or which does not have the
	* IPv6 HBH Router Alert option.
	* As IPv6 HBH options are stripped in ip6_input() we must
	* check an mbuf header flag.
	* XXX Should we also sanity check that these messages
	* were directed to a link-local multicast prefix?
	*/
	if ((ip6->ip6_hlim != 1) \|\| (m->m_flags & M_RTALERT_MLD) == 0)
	goto freeit;
	if (mld_input(m, off, icmp6len) != 0)
	return (IPPROTO_DONE);
	/* m stays. */
	break;

	case ICMP6_WRUREQUEST: /* ICMP6_FQDN_QUERY */
	{
	enum { WRU, FQDN } mode;

	if (!V_icmp6_nodeinfo)
	break;

	if (icmp6len == sizeof(struct icmp6_hdr) + 4)
	mode = WRU;
	else if (icmp6len >= sizeof(struct icmp6_nodeinfo))
	mode = FQDN;
	else
	goto badlen;

	if (mode == FQDN) {
	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(struct icmp6_nodeinfo),
	IPPROTO_DONE);
	#endif
	n = m_copy(m, 0, M_COPYALL);
	if (n)
	n = ni6_input(n, off);
	/* XXX meaningless if n == NULL */
	noff = sizeof(struct ip6_hdr);
	} else {
	struct prison *pr;
	u_char *p;
	int maxlen, maxhlen, hlen;

	/*
	* XXX: this combination of flags is pointless,
	* but should we keep this for compatibility?
	*/
	if ((V_icmp6_nodeinfo & 5) != 5)
	break;

	if (code != 0)
	goto badcode;
	maxlen = sizeof(nip6) + sizeof(nicmp6) + 4;
	if (maxlen >= MCLBYTES) {
	/* Give up remote */
	break;
	}
	MGETHDR(n, M_DONTWAIT, m->m_type);
	if (n && maxlen > MHLEN) {
	MCLGET(n, M_DONTWAIT);
	if ((n->m_flags & M_EXT) == 0) {
	m_free(n);
	n = NULL;
	}
	}
	if (n && !m_dup_pkthdr(n, m, M_DONTWAIT)) {
	/*
	* Previous code did a blind M_COPY_PKTHDR
	* and said "just for rcvif". If true, then
	* we could tolerate the dup failing (due to
	* the deep copy of the tag chain). For now
	* be conservative and just fail.
	*/
	m_free(n);
	n = NULL;
	}
	if (n == NULL) {
	/* Give up remote */
	break;
	}
	n->m_pkthdr.rcvif = NULL;
	n->m_len = 0;
	maxhlen = M_TRAILINGSPACE(n) - maxlen;
	pr = curthread->td_ucred->cr_prison;
	mtx_lock(&pr->pr_mtx);
	hlen = strlen(pr->pr_hostname);
	if (maxhlen > hlen)
	maxhlen = hlen;
	/*
	* Copy IPv6 and ICMPv6 only.
	*/
	nip6 = mtod(n, struct ip6_hdr *);
	bcopy(ip6, nip6, sizeof(struct ip6_hdr));
	nicmp6 = (struct icmp6_hdr *)(nip6 + 1);
	bcopy(icmp6, nicmp6, sizeof(struct icmp6_hdr));
	p = (u_char *)(nicmp6 + 1);
	bzero(p, 4);
	/* meaningless TTL */
	bcopy(pr->pr_hostname, p + 4, maxhlen);
	mtx_unlock(&pr->pr_mtx);
	noff = sizeof(struct ip6_hdr);
	n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
	sizeof(struct icmp6_hdr) + 4 + maxhlen;
	nicmp6->icmp6_type = ICMP6_WRUREPLY;
	nicmp6->icmp6_code = 0;
	}
	if (n) {
	ICMP6STAT_INC(icp6s_reflect);
	ICMP6STAT_INC(icp6s_outhist[ICMP6_WRUREPLY]);
	icmp6_reflect(n, noff);
	}
	break;
	}

	case ICMP6_WRUREPLY:
	if (code != 0)
	goto badcode;
	break;

	case ND_ROUTER_SOLICIT:
	icmp6_ifstat_inc(ifp, ifs6_in_routersolicit);
	if (code != 0)
	goto badcode;
	if (icmp6len < sizeof(struct nd_router_solicit))
	goto badlen;
	if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
	/* give up local */
	nd6_rs_input(m, off, icmp6len);
	m = NULL;
	goto freeit;
	}
	nd6_rs_input(n, off, icmp6len);
	/* m stays. */
	break;

	case ND_ROUTER_ADVERT:
	icmp6_ifstat_inc(ifp, ifs6_in_routeradvert);
	if (code != 0)
	goto badcode;
	if (icmp6len < sizeof(struct nd_router_advert))
	goto badlen;
	if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
	/* give up local */
	nd6_ra_input(m, off, icmp6len);
	m = NULL;
	goto freeit;
	}
	nd6_ra_input(n, off, icmp6len);
	/* m stays. */
	break;

	case ND_NEIGHBOR_SOLICIT:
	icmp6_ifstat_inc(ifp, ifs6_in_neighborsolicit);
	if (code != 0)
	goto badcode;
	if (icmp6len < sizeof(struct nd_neighbor_solicit))
	goto badlen;
	if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
	/* give up local */
	nd6_ns_input(m, off, icmp6len);
	m = NULL;
	goto freeit;
	}
	nd6_ns_input(n, off, icmp6len);
	/* m stays. */
	break;

	case ND_NEIGHBOR_ADVERT:
	icmp6_ifstat_inc(ifp, ifs6_in_neighboradvert);
	if (code != 0)
	goto badcode;
	if (icmp6len < sizeof(struct nd_neighbor_advert))
	goto badlen;
	if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
	/* give up local */
	nd6_na_input(m, off, icmp6len);
	m = NULL;
	goto freeit;
	}
	nd6_na_input(n, off, icmp6len);
	/* m stays. */
	break;

	case ND_REDIRECT:
	icmp6_ifstat_inc(ifp, ifs6_in_redirect);
	if (code != 0)
	goto badcode;
	if (icmp6len < sizeof(struct nd_redirect))
	goto badlen;
	if ((n = m_copym(m, 0, M_COPYALL, M_DONTWAIT)) == NULL) {
	/* give up local */
	icmp6_redirect_input(m, off);
	m = NULL;
	goto freeit;
	}
	icmp6_redirect_input(n, off);
	/* m stays. */
	break;

	case ICMP6_ROUTER_RENUMBERING:
	if (code != ICMP6_ROUTER_RENUMBERING_COMMAND &&
	code != ICMP6_ROUTER_RENUMBERING_RESULT)
	goto badcode;
	if (icmp6len < sizeof(struct icmp6_router_renum))
	goto badlen;
	break;

	default:
	nd6log((LOG_DEBUG,
	"icmp6_input: unknown type %d(src=%s, dst=%s, ifid=%d)\n",
	icmp6->icmp6_type, ip6_sprintf(ip6bufs, &ip6->ip6_src),
	ip6_sprintf(ip6bufd, &ip6->ip6_dst),
	ifp ? ifp->if_index : 0));
	if (icmp6->icmp6_type < ICMP6_ECHO_REQUEST) {
	/* ICMPv6 error: MUST deliver it by spec... */
	code = PRC_NCMDS;
	/* deliver */
	} else {
	/* ICMPv6 informational: MUST not deliver */
	break;
	}
	deliver:
	if (icmp6_notify_error(&m, off, icmp6len, code)) {
	/* In this case, m should've been freed. */
	return (IPPROTO_DONE);
	}
	break;

	badcode:
	ICMP6STAT_INC(icp6s_badcode);
	break;

	badlen:
	ICMP6STAT_INC(icp6s_badlen);
	break;
	}

	/* deliver the packet to appropriate sockets */
	icmp6_rip6_input(&m, *offp);

	return IPPROTO_DONE;

	freeit:
	m_freem(m);
	return IPPROTO_DONE;
	}

	static int
	icmp6_notify_error(struct mbuf **mp, int off, int icmp6len, int code)
	{
	INIT_VNET_INET6(curvnet);
	struct mbuf m = mp;
	struct icmp6_hdr *icmp6;
	struct ip6_hdr *eip6;
	u_int32_t notifymtu;
	struct sockaddr_in6 icmp6src, icmp6dst;

	if (icmp6len < sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr)) {
	ICMP6STAT_INC(icp6s_tooshort);
	goto freeit;
	}
	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off,
	sizeof(struct icmp6_hdr) + sizeof(struct ip6_hdr), -1);
	icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
	#else
	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
	sizeof(*icmp6) + sizeof(struct ip6_hdr));
	if (icmp6 == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return (-1);
	}
	#endif
	eip6 = (struct ip6_hdr *)(icmp6 + 1);

	/* Detect the upper level protocol */
	{
	void (ctlfunc)(int, struct sockaddr , void *);
	u_int8_t nxt = eip6->ip6_nxt;
	int eoff = off + sizeof(struct icmp6_hdr) +
	sizeof(struct ip6_hdr);
	struct ip6ctlparam ip6cp;
	struct in6_addr *finaldst = NULL;
	int icmp6type = icmp6->icmp6_type;
	struct ip6_frag *fh;
	struct ip6_rthdr *rth;
	struct ip6_rthdr0 *rth0;
	int rthlen;

	while (1) { /* XXX: should avoid infinite loop explicitly? */
	struct ip6_ext *eh;

	switch (nxt) {
	case IPPROTO_HOPOPTS:
	case IPPROTO_DSTOPTS:
	case IPPROTO_AH:
	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, 0,
	eoff + sizeof(struct ip6_ext), -1);
	eh = (struct ip6_ext *)(mtod(m, caddr_t) + eoff);
	#else
	IP6_EXTHDR_GET(eh, struct ip6_ext *, m,
	eoff, sizeof(*eh));
	if (eh == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return (-1);
	}
	#endif

	if (nxt == IPPROTO_AH)
	eoff += (eh->ip6e_len + 2) << 2;
	else
	eoff += (eh->ip6e_len + 1) << 3;
	nxt = eh->ip6e_nxt;
	break;
	case IPPROTO_ROUTING:
	/*
	* When the erroneous packet contains a
	* routing header, we should examine the
	* header to determine the final destination.
	* Otherwise, we can't properly update
	* information that depends on the final
	* destination (e.g. path MTU).
	*/
	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, 0, eoff + sizeof(*rth), -1);
	rth = (struct ip6_rthdr *)
	(mtod(m, caddr_t) + eoff);
	#else
	IP6_EXTHDR_GET(rth, struct ip6_rthdr *, m,
	eoff, sizeof(*rth));
	if (rth == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return (-1);
	}
	#endif
	rthlen = (rth->ip6r_len + 1) << 3;
	/*
	* XXX: currently there is no
	* officially defined type other
	* than type-0.
	* Note that if the segment left field
	* is 0, all intermediate hops must
	* have been passed.
	*/
	if (rth->ip6r_segleft &&
	rth->ip6r_type == IPV6_RTHDR_TYPE_0) {
	int hops;

	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, 0, eoff + rthlen, -1);
	rth0 = (struct ip6_rthdr0 *)
	(mtod(m, caddr_t) + eoff);
	#else
	IP6_EXTHDR_GET(rth0,
	struct ip6_rthdr0 *, m,
	eoff, rthlen);
	if (rth0 == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return (-1);
	}
	#endif
	/* just ignore a bogus header */
	if ((rth0->ip6r0_len % 2) == 0 &&
	(hops = rth0->ip6r0_len/2))
	finaldst = (struct in6_addr *)(rth0 + 1) + (hops - 1);
	}
	eoff += rthlen;
	nxt = rth->ip6r_nxt;
	break;
	case IPPROTO_FRAGMENT:
	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, 0, eoff +
	sizeof(struct ip6_frag), -1);
	fh = (struct ip6_frag *)(mtod(m, caddr_t) +
	eoff);
	#else
	IP6_EXTHDR_GET(fh, struct ip6_frag *, m,
	eoff, sizeof(*fh));
	if (fh == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return (-1);
	}
	#endif
	/*
	* Data after a fragment header is meaningless
	* unless it is the first fragment, but
	* we'll go to the notify label for path MTU
	* discovery.
	*/
	if (fh->ip6f_offlg & IP6F_OFF_MASK)
	goto notify;

	eoff += sizeof(struct ip6_frag);
	nxt = fh->ip6f_nxt;
	break;
	default:
	/*
	* This case includes ESP and the No Next
	* Header. In such cases going to the notify
	* label does not have any meaning
	* (i.e. ctlfunc will be NULL), but we go
	* anyway since we might have to update
	* path MTU information.
	*/
	goto notify;
	}
	}
	notify:
	#ifndef PULLDOWN_TEST
	icmp6 = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
	#else
	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr *, m, off,
	sizeof(*icmp6) + sizeof(struct ip6_hdr));
	if (icmp6 == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return (-1);
	}
	#endif

	/*
	* retrieve parameters from the inner IPv6 header, and convert
	* them into sockaddr structures.
	* XXX: there is no guarantee that the source or destination
	* addresses of the inner packet are in the same scope as
	* the addresses of the icmp packet. But there is no other
	* way to determine the zone.
	*/
	eip6 = (struct ip6_hdr *)(icmp6 + 1);

	bzero(&icmp6dst, sizeof(icmp6dst));
	icmp6dst.sin6_len = sizeof(struct sockaddr_in6);
	icmp6dst.sin6_family = AF_INET6;
	if (finaldst == NULL)
	icmp6dst.sin6_addr = eip6->ip6_dst;
	else
	icmp6dst.sin6_addr = *finaldst;
	if (in6_setscope(&icmp6dst.sin6_addr, m->m_pkthdr.rcvif, NULL))
	goto freeit;
	bzero(&icmp6src, sizeof(icmp6src));
	icmp6src.sin6_len = sizeof(struct sockaddr_in6);
	icmp6src.sin6_family = AF_INET6;
	icmp6src.sin6_addr = eip6->ip6_src;
	if (in6_setscope(&icmp6src.sin6_addr, m->m_pkthdr.rcvif, NULL))
	goto freeit;
	icmp6src.sin6_flowinfo =
	(eip6->ip6_flow & IPV6_FLOWLABEL_MASK);

	if (finaldst == NULL)
	finaldst = &eip6->ip6_dst;
	ip6cp.ip6c_m = m;
	ip6cp.ip6c_icmp6 = icmp6;
	ip6cp.ip6c_ip6 = (struct ip6_hdr *)(icmp6 + 1);
	ip6cp.ip6c_off = eoff;
	ip6cp.ip6c_finaldst = finaldst;
	ip6cp.ip6c_src = &icmp6src;
	ip6cp.ip6c_nxt = nxt;

	if (icmp6type == ICMP6_PACKET_TOO_BIG) {
	notifymtu = ntohl(icmp6->icmp6_mtu);
	ip6cp.ip6c_cmdarg = (void *)&notifymtu;
	icmp6_mtudisc_update(&ip6cp, 1); /XXX/
	}

	ctlfunc = (void ()(int, struct sockaddr , void *))
	(inet6sw[ip6_protox[nxt]].pr_ctlinput);
	if (ctlfunc) {
	(void) (ctlfunc)(code, (struct sockaddr )&icmp6dst,
	&ip6cp);
	}
	}
	*mp = m;
	return (0);

	freeit:
	m_freem(m);
	return (-1);
	}

	void
	icmp6_mtudisc_update(struct ip6ctlparam *ip6cp, int validated)
	{
	INIT_VNET_INET6(curvnet);
	struct in6_addr *dst = ip6cp->ip6c_finaldst;
	struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6;
	struct mbuf m = ip6cp->ip6c_m; / will be necessary for scope issue */
	u_int mtu = ntohl(icmp6->icmp6_mtu);
	struct in_conninfo inc;

	#if 0
	/*
	* RFC2460 section 5, last paragraph.
	* even though minimum link MTU for IPv6 is IPV6_MMTU,
	* we may see ICMPv6 too big with mtu < IPV6_MMTU
	* due to packet translator in the middle.
	* see ip6_output() and ip6_getpmtu() "alwaysfrag" case for
	* special handling.
	*/
	if (mtu < IPV6_MMTU)
	return;
	#endif

	/*
	* we reject ICMPv6 too big with abnormally small value.
	* XXX what is the good definition of "abnormally small"?
	*/
	if (mtu < sizeof(struct ip6_hdr) + sizeof(struct ip6_frag) + 8)
	return;

	if (!validated)
	return;

	/*
	* In case the suggested mtu is less than IPV6_MMTU, we
	* only need to remember that it was for above mentioned
	* "alwaysfrag" case.
	* Try to be as close to the spec as possible.
	*/
	if (mtu < IPV6_MMTU)
	mtu = IPV6_MMTU - 8;

	bzero(&inc, sizeof(inc));
	inc.inc_flags \|= INC_ISIPV6;
	inc.inc6_faddr = *dst;
	if (in6_setscope(&inc.inc6_faddr, m->m_pkthdr.rcvif, NULL))
	return;

	if (mtu < tcp_maxmtu6(&inc, NULL)) {
	tcp_hc_updatemtu(&inc, mtu);
	ICMP6STAT_INC(icp6s_pmtuchg);
	}
	}

	/*
	* Process a Node Information Query packet, based on
	* draft-ietf-ipngwg-icmp-name-lookups-07.
	*
	* Spec incompatibilities:
	* - IPv6 Subject address handling
	* - IPv4 Subject address handling support missing
	* - Proxy reply (answer even if it's not for me)
	* - joins NI group address at in6_ifattach() time only, does not cope
	* with hostname changes by sethostname(3)
	*/
	static struct mbuf *
	ni6_input(struct mbuf *m, int off)
	{
	INIT_VNET_INET6(curvnet);
	struct icmp6_nodeinfo ni6, nni6;
	struct mbuf *n = NULL;
	struct prison *pr;
	u_int16_t qtype;
	int subjlen;
	int replylen = sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
	struct ni_reply_fqdn *fqdn;
	int addrs; /* for NI_QTYPE_NODEADDR */
	struct ifnet ifp = NULL; / for NI_QTYPE_NODEADDR */
	struct in6_addr in6_subj; /* subject address */
	struct ip6_hdr *ip6;
	int oldfqdn = 0; /* if 1, return pascal string (03 draft) */
	char *subj = NULL;
	struct in6_ifaddr *ia6 = NULL;

	ip6 = mtod(m, struct ip6_hdr *);
	#ifndef PULLDOWN_TEST
	ni6 = (struct icmp6_nodeinfo *)(mtod(m, caddr_t) + off);
	#else
	IP6_EXTHDR_GET(ni6, struct icmp6_nodeinfo , m, off, sizeof(ni6));
	if (ni6 == NULL) {
	/* m is already reclaimed */
	return (NULL);
	}
	#endif

	/*
	* Validate IPv6 source address.
	* The default configuration MUST be to refuse answering queries from
	* global-scope addresses according to RFC4602.
	* Notes:
	* - it's not very clear what "refuse" means; this implementation
	* simply drops it.
	* - it's not very easy to identify global-scope (unicast) addresses
	* since there are many prefixes for them. It should be safer
	* and in practice sufficient to check "all" but loopback and
	* link-local (note that site-local unicast was deprecated and
	* ULA is defined as global scope-wise)
	*/
	if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_GLOBALOK) == 0 &&
	!IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) &&
	!IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_src))
	goto bad;

	/*
	* Validate IPv6 destination address.
	*
	* The Responder must discard the Query without further processing
	* unless it is one of the Responder's unicast or anycast addresses, or
	* a link-local scope multicast address which the Responder has joined.
	* [RFC4602, Section 5.]
	*/
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
	if (!IN6_IS_ADDR_MC_LINKLOCAL(&ip6->ip6_dst))
	goto bad;
	/* else it's a link-local multicast, fine */
	} else { /* unicast or anycast */
	if ((ia6 = ip6_getdstifaddr(m)) == NULL)
	goto bad; /* XXX impossible */

	if ((ia6->ia6_flags & IN6_IFF_TEMPORARY) &&
	!(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK)) {
	ifa_free(&ia6->ia_ifa);
	nd6log((LOG_DEBUG, "ni6_input: ignore node info to "
	"a temporary address in %s:%d",
	__FILE__, __LINE__));
	goto bad;
	}
	ifa_free(&ia6->ia_ifa);
	}

	/* validate query Subject field. */
	qtype = ntohs(ni6->ni_qtype);
	subjlen = m->m_pkthdr.len - off - sizeof(struct icmp6_nodeinfo);
	switch (qtype) {
	case NI_QTYPE_NOOP:
	case NI_QTYPE_SUPTYPES:
	/* 07 draft */
	if (ni6->ni_code == ICMP6_NI_SUBJ_FQDN && subjlen == 0)
	break;
	/* FALLTHROUGH */
	case NI_QTYPE_FQDN:
	case NI_QTYPE_NODEADDR:
	case NI_QTYPE_IPV4ADDR:
	switch (ni6->ni_code) {
	case ICMP6_NI_SUBJ_IPV6:
	#if ICMP6_NI_SUBJ_IPV6 != 0
	case 0:
	#endif
	/*
	* backward compatibility - try to accept 03 draft
	* format, where no Subject is present.
	*/
	if (qtype == NI_QTYPE_FQDN && ni6->ni_code == 0 &&
	subjlen == 0) {
	oldfqdn++;
	break;
	}
	#if ICMP6_NI_SUBJ_IPV6 != 0
	if (ni6->ni_code != ICMP6_NI_SUBJ_IPV6)
	goto bad;
	#endif

	if (subjlen != sizeof(struct in6_addr))
	goto bad;

	/*
	* Validate Subject address.
	*
	* Not sure what exactly "address belongs to the node"
	* means in the spec, is it just unicast, or what?
	*
	* At this moment we consider Subject address as
	* "belong to the node" if the Subject address equals
	* to the IPv6 destination address; validation for
	* IPv6 destination address should have done enough
	* check for us.
	*
	* We do not do proxy at this moment.
	*/
	/* m_pulldown instead of copy? */
	m_copydata(m, off + sizeof(struct icmp6_nodeinfo),
	subjlen, (caddr_t)&in6_subj);
	if (in6_setscope(&in6_subj, m->m_pkthdr.rcvif, NULL))
	goto bad;

	subj = (char *)&in6_subj;
	if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &in6_subj))
	break;

	/*
	* XXX if we are to allow other cases, we should really
	* be careful about scope here.
	* basically, we should disallow queries toward IPv6
	* destination X with subject Y,
	* if scope(X) > scope(Y).
	* if we allow scope(X) > scope(Y), it will result in
	* information leakage across scope boundary.
	*/
	goto bad;

	case ICMP6_NI_SUBJ_FQDN:
	/*
	* Validate Subject name with gethostname(3).
	*
	* The behavior may need some debate, since:
	* - we are not sure if the node has FQDN as
	* hostname (returned by gethostname(3)).
	* - the code does wildcard match for truncated names.
	* however, we are not sure if we want to perform
	* wildcard match, if gethostname(3) side has
	* truncated hostname.
	*/
	pr = curthread->td_ucred->cr_prison;
	mtx_lock(&pr->pr_mtx);
	n = ni6_nametodns(pr->pr_hostname,
	strlen(pr->pr_hostname), 0);
	mtx_unlock(&pr->pr_mtx);
	if (!n \|\| n->m_next \|\| n->m_len == 0)
	goto bad;
	IP6_EXTHDR_GET(subj, char *, m,
	off + sizeof(struct icmp6_nodeinfo), subjlen);
	if (subj == NULL)
	goto bad;
	if (!ni6_dnsmatch(subj, subjlen, mtod(n, const char *),
	n->m_len)) {
	goto bad;
	}
	m_freem(n);
	n = NULL;
	break;

	case ICMP6_NI_SUBJ_IPV4: /* XXX: to be implemented? */
	default:
	goto bad;
	}
	break;
	}

	/* refuse based on configuration. XXX ICMP6_NI_REFUSED? */
	switch (qtype) {
	case NI_QTYPE_FQDN:
	if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_FQDNOK) == 0)
	goto bad;
	break;
	case NI_QTYPE_NODEADDR:
	case NI_QTYPE_IPV4ADDR:
	if ((V_icmp6_nodeinfo & ICMP6_NODEINFO_NODEADDROK) == 0)
	goto bad;
	break;
	}

	/* guess reply length */
	switch (qtype) {
	case NI_QTYPE_NOOP:
	break; /* no reply data */
	case NI_QTYPE_SUPTYPES:
	replylen += sizeof(u_int32_t);
	break;
	case NI_QTYPE_FQDN:
	/* XXX will append an mbuf */
	replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
	break;
	case NI_QTYPE_NODEADDR:
	addrs = ni6_addrs(ni6, m, &ifp, (struct in6_addr *)subj);
	if ((replylen += addrs * (sizeof(struct in6_addr) +
	sizeof(u_int32_t))) > MCLBYTES)
	replylen = MCLBYTES; /* XXX: will truncate pkt later */
	break;
	case NI_QTYPE_IPV4ADDR:
	/* unsupported - should respond with unknown Qtype? */
	break;
	default:
	/*
	* XXX: We must return a reply with the ICMP6 code
	* `unknown Qtype' in this case. However we regard the case
	* as an FQDN query for backward compatibility.
	* Older versions set a random value to this field,
	* so it rarely varies in the defined qtypes.
	* But the mechanism is not reliable...
	* maybe we should obsolete older versions.
	*/
	qtype = NI_QTYPE_FQDN;
	/* XXX will append an mbuf */
	replylen += offsetof(struct ni_reply_fqdn, ni_fqdn_namelen);
	oldfqdn++;
	break;
	}

	/* allocate an mbuf to reply. */
	MGETHDR(n, M_DONTWAIT, m->m_type);
	if (n == NULL) {
	m_freem(m);
	return (NULL);
	}
	M_MOVE_PKTHDR(n, m); /* just for recvif */
	if (replylen > MHLEN) {
	if (replylen > MCLBYTES) {
	/*
	* XXX: should we try to allocate more? But MCLBYTES
	* is probably much larger than IPV6_MMTU...
	*/
	goto bad;
	}
	MCLGET(n, M_DONTWAIT);
	if ((n->m_flags & M_EXT) == 0) {
	goto bad;
	}
	}
	n->m_pkthdr.len = n->m_len = replylen;

	/* copy mbuf header and IPv6 + Node Information base headers */
	bcopy(mtod(m, caddr_t), mtod(n, caddr_t), sizeof(struct ip6_hdr));
	nni6 = (struct icmp6_nodeinfo )(mtod(n, struct ip6_hdr ) + 1);
	bcopy((caddr_t)ni6, (caddr_t)nni6, sizeof(struct icmp6_nodeinfo));

	/* qtype dependent procedure */
	switch (qtype) {
	case NI_QTYPE_NOOP:
	nni6->ni_code = ICMP6_NI_SUCCESS;
	nni6->ni_flags = 0;
	break;
	case NI_QTYPE_SUPTYPES:
	{
	u_int32_t v;
	nni6->ni_code = ICMP6_NI_SUCCESS;
	nni6->ni_flags = htons(0x0000); /* raw bitmap */
	/* supports NOOP, SUPTYPES, FQDN, and NODEADDR */
	v = (u_int32_t)htonl(0x0000000f);
	bcopy(&v, nni6 + 1, sizeof(u_int32_t));
	break;
	}
	case NI_QTYPE_FQDN:
	nni6->ni_code = ICMP6_NI_SUCCESS;
	fqdn = (struct ni_reply_fqdn *)(mtod(n, caddr_t) +
	sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo));
	nni6->ni_flags = 0; /* XXX: meaningless TTL */
	fqdn->ni_fqdn_ttl = 0; /* ditto. */
	/*
	* XXX do we really have FQDN in hostname?
	*/
	pr = curthread->td_ucred->cr_prison;
	mtx_lock(&pr->pr_mtx);
	n->m_next = ni6_nametodns(pr->pr_hostname,
	strlen(pr->pr_hostname), oldfqdn);
	mtx_unlock(&pr->pr_mtx);
	if (n->m_next == NULL)
	goto bad;
	/* XXX we assume that n->m_next is not a chain */
	if (n->m_next->m_next != NULL)
	goto bad;
	n->m_pkthdr.len += n->m_next->m_len;
	break;
	case NI_QTYPE_NODEADDR:
	{
	int lenlim, copied;

	nni6->ni_code = ICMP6_NI_SUCCESS;
	n->m_pkthdr.len = n->m_len =
	sizeof(struct ip6_hdr) + sizeof(struct icmp6_nodeinfo);
	lenlim = M_TRAILINGSPACE(n);
	copied = ni6_store_addrs(ni6, nni6, ifp, lenlim);
	/* XXX: reset mbuf length */
	n->m_pkthdr.len = n->m_len = sizeof(struct ip6_hdr) +
	sizeof(struct icmp6_nodeinfo) + copied;
	break;
	}
	default:
	break; /* XXX impossible! */
	}

	nni6->ni_type = ICMP6_NI_REPLY;
	m_freem(m);
	return (n);

	bad:
	m_freem(m);
	if (n)
	m_freem(n);
	return (NULL);
	}

	/*
	* make a mbuf with DNS-encoded string. no compression support.
	*
	* XXX names with less than 2 dots (like "foo" or "foo.section") will be
	* treated as truncated name (two \0 at the end). this is a wild guess.
	*
	* old - return pascal string if non-zero
	*/
	static struct mbuf *
	ni6_nametodns(const char *name, int namelen, int old)
	{
	struct mbuf *m;
	char cp, ep;
	const char p, q;
	int i, len, nterm;

	if (old)
	len = namelen + 1;
	else
	len = MCLBYTES;

	/* because MAXHOSTNAMELEN is usually 256, we use cluster mbuf */
	MGET(m, M_DONTWAIT, MT_DATA);
	if (m && len > MLEN) {
	MCLGET(m, M_DONTWAIT);
	if ((m->m_flags & M_EXT) == 0)
	goto fail;
	}
	if (!m)
	goto fail;
	m->m_next = NULL;

	if (old) {
	m->m_len = len;
	mtod(m, char ) = namelen;
	bcopy(name, mtod(m, char *) + 1, namelen);
	return m;
	} else {
	m->m_len = 0;
	cp = mtod(m, char *);
	ep = mtod(m, char *) + M_TRAILINGSPACE(m);

	/* if not certain about my name, return empty buffer */
	if (namelen == 0)
	return m;

	/*
	* guess if it looks like shortened hostname, or FQDN.
	* shortened hostname needs two trailing "\0".
	*/
	i = 0;
	for (p = name; p < name + namelen; p++) {
	if (p && p == '.')
	i++;
	}
	if (i < 2)
	nterm = 2;
	else
	nterm = 1;

	p = name;
	while (cp < ep && p < name + namelen) {
	i = 0;
	for (q = p; q < name + namelen && q && q != '.'; q++)
	i++;
	/* result does not fit into mbuf */
	if (cp + i + 1 >= ep)
	goto fail;
	/*
	* DNS label length restriction, RFC1035 page 8.
	* "i == 0" case is included here to avoid returning
	* 0-length label on "foo..bar".
	*/
	if (i <= 0 \|\| i >= 64)
	goto fail;
	*cp++ = i;
	bcopy(p, cp, i);
	cp += i;
	p = q;
	if (p < name + namelen && *p == '.')
	p++;
	}
	/* termination */
	if (cp + nterm >= ep)
	goto fail;
	while (nterm-- > 0)
	*cp++ = '\0';
	m->m_len = cp - mtod(m, char *);
	return m;
	}

	panic("should not reach here");
	/* NOTREACHED */

	fail:
	if (m)
	m_freem(m);
	return NULL;
	}

	/*
	* check if two DNS-encoded string matches. takes care of truncated
	* form (with \0\0 at the end). no compression support.
	* XXX upper/lowercase match (see RFC2065)
	*/
	static int
	ni6_dnsmatch(const char a, int alen, const char b, int blen)
	{
	const char a0, b0;
	int l;

	/* simplest case - need validation? */
	if (alen == blen && bcmp(a, b, alen) == 0)
	return 1;

	a0 = a;
	b0 = b;

	/* termination is mandatory */
	if (alen < 2 \|\| blen < 2)
	return 0;
	if (a0[alen - 1] != '\0' \|\| b0[blen - 1] != '\0')
	return 0;
	alen--;
	blen--;

	while (a - a0 < alen && b - b0 < blen) {
	if (a - a0 + 1 > alen \|\| b - b0 + 1 > blen)
	return 0;

	if ((signed char)a[0] < 0 \|\| (signed char)b[0] < 0)
	return 0;
	/* we don't support compression yet */
	if (a[0] >= 64 \|\| b[0] >= 64)
	return 0;

	/* truncated case */
	if (a[0] == 0 && a - a0 == alen - 1)
	return 1;
	if (b[0] == 0 && b - b0 == blen - 1)
	return 1;
	if (a[0] == 0 \|\| b[0] == 0)
	return 0;

	if (a[0] != b[0])
	return 0;
	l = a[0];
	if (a - a0 + 1 + l > alen \|\| b - b0 + 1 + l > blen)
	return 0;
	if (bcmp(a + 1, b + 1, l) != 0)
	return 0;

	a += 1 + l;
	b += 1 + l;
	}

	if (a - a0 == alen && b - b0 == blen)
	return 1;
	else
	return 0;
	}

	/*
	* calculate the number of addresses to be returned in the node info reply.
	*/
	static int
	ni6_addrs(struct icmp6_nodeinfo ni6, struct mbuf m, struct ifnet **ifpp,
	struct in6_addr *subj)
	{
	INIT_VNET_NET(curvnet);
	INIT_VNET_INET6(curvnet);
	struct ifnet *ifp;
	struct in6_ifaddr *ifa6;
	struct ifaddr *ifa;
	int addrs = 0, addrsofif, iffound = 0;
	int niflags = ni6->ni_flags;

	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0) {
	switch (ni6->ni_code) {
	case ICMP6_NI_SUBJ_IPV6:
	if (subj == NULL) /* must be impossible... */
	return (0);
	break;
	default:
	/*
	* XXX: we only support IPv6 subject address for
	* this Qtype.
	*/
	return (0);
	}
	}

	IFNET_RLOCK();
	for (ifp = TAILQ_FIRST(&V_ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
	addrsofif = 0;
	IF_ADDR_LOCK(ifp);
	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
	if (ifa->ifa_addr->sa_family != AF_INET6)
	continue;
	ifa6 = (struct in6_ifaddr *)ifa;

	if ((niflags & NI_NODEADDR_FLAG_ALL) == 0 &&
	IN6_ARE_ADDR_EQUAL(subj, &ifa6->ia_addr.sin6_addr))
	iffound = 1;

	/*
	* IPv4-mapped addresses can only be returned by a
	* Node Information proxy, since they represent
	* addresses of IPv4-only nodes, which perforce do
	* not implement this protocol.
	* [icmp-name-lookups-07, Section 5.4]
	* So we don't support NI_NODEADDR_FLAG_COMPAT in
	* this function at this moment.
	*/

	/* What do we have to do about ::1? */
	switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
	case IPV6_ADDR_SCOPE_LINKLOCAL:
	if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
	continue;
	break;
	case IPV6_ADDR_SCOPE_SITELOCAL:
	if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
	continue;
	break;
	case IPV6_ADDR_SCOPE_GLOBAL:
	if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
	continue;
	break;
	default:
	continue;
	}

	/*
	* check if anycast is okay.
	* XXX: just experimental. not in the spec.
	*/
	if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
	(niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
	continue; /* we need only unicast addresses */
	if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
	(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
	continue;
	}
	addrsofif++; /* count the address */
	}
	IF_ADDR_UNLOCK(ifp);
	if (iffound) {
	*ifpp = ifp;
	IFNET_RUNLOCK();
	return (addrsofif);
	}

	addrs += addrsofif;
	}
	IFNET_RUNLOCK();

	return (addrs);
	}

	static int
	ni6_store_addrs(struct icmp6_nodeinfo ni6, struct icmp6_nodeinfo nni6,
	struct ifnet *ifp0, int resid)
	{
	INIT_VNET_NET(curvnet);
	INIT_VNET_INET6(curvnet);
	struct ifnet *ifp = ifp0 ? ifp0 : TAILQ_FIRST(&V_ifnet);
	struct in6_ifaddr *ifa6;
	struct ifaddr *ifa;
	struct ifnet *ifp_dep = NULL;
	int copied = 0, allow_deprecated = 0;
	u_char cp = (u_char )(nni6 + 1);
	int niflags = ni6->ni_flags;
	u_int32_t ltime;

	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
	return (0); /* needless to copy */

	IFNET_RLOCK();
	again:

	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
	IF_ADDR_LOCK(ifp);
	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
	if (ifa->ifa_addr->sa_family != AF_INET6)
	continue;
	ifa6 = (struct in6_ifaddr *)ifa;

	if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) != 0 &&
	allow_deprecated == 0) {
	/*
	* prefererred address should be put before
	* deprecated addresses.
	*/

	/* record the interface for later search */
	if (ifp_dep == NULL)
	ifp_dep = ifp;

	continue;
	} else if ((ifa6->ia6_flags & IN6_IFF_DEPRECATED) == 0 &&
	allow_deprecated != 0)
	continue; /* we now collect deprecated addrs */

	/* What do we have to do about ::1? */
	switch (in6_addrscope(&ifa6->ia_addr.sin6_addr)) {
	case IPV6_ADDR_SCOPE_LINKLOCAL:
	if ((niflags & NI_NODEADDR_FLAG_LINKLOCAL) == 0)
	continue;
	break;
	case IPV6_ADDR_SCOPE_SITELOCAL:
	if ((niflags & NI_NODEADDR_FLAG_SITELOCAL) == 0)
	continue;
	break;
	case IPV6_ADDR_SCOPE_GLOBAL:
	if ((niflags & NI_NODEADDR_FLAG_GLOBAL) == 0)
	continue;
	break;
	default:
	continue;
	}

	/*
	* check if anycast is okay.
	* XXX: just experimental. not in the spec.
	*/
	if ((ifa6->ia6_flags & IN6_IFF_ANYCAST) != 0 &&
	(niflags & NI_NODEADDR_FLAG_ANYCAST) == 0)
	continue;
	if ((ifa6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
	(V_icmp6_nodeinfo & ICMP6_NODEINFO_TMPADDROK) == 0) {
	continue;
	}

	/* now we can copy the address */
	if (resid < sizeof(struct in6_addr) +
	sizeof(u_int32_t)) {
	IF_ADDR_UNLOCK(ifp);
	/*
	* We give up much more copy.
	* Set the truncate flag and return.
	*/
	nni6->ni_flags \|= NI_NODEADDR_FLAG_TRUNCATE;
	IFNET_RUNLOCK();
	return (copied);
	}

	/*
	* Set the TTL of the address.
	* The TTL value should be one of the following
	* according to the specification:
	*
	* 1. The remaining lifetime of a DHCP lease on the
	* address, or
	* 2. The remaining Valid Lifetime of a prefix from
	* which the address was derived through Stateless
	* Autoconfiguration.
	*
	* Note that we currently do not support stateful
	* address configuration by DHCPv6, so the former
	* case can't happen.
	*/
	if (ifa6->ia6_lifetime.ia6t_expire == 0)
	ltime = ND6_INFINITE_LIFETIME;
	else {
	if (ifa6->ia6_lifetime.ia6t_expire >
	time_second)
	ltime = htonl(ifa6->ia6_lifetime.ia6t_expire - time_second);
	else
	ltime = 0;
	}

	bcopy(&ltime, cp, sizeof(u_int32_t));
	cp += sizeof(u_int32_t);

	/* copy the address itself */
	bcopy(&ifa6->ia_addr.sin6_addr, cp,
	sizeof(struct in6_addr));
	in6_clearscope((struct in6_addr )cp); / XXX */
	cp += sizeof(struct in6_addr);

	resid -= (sizeof(struct in6_addr) + sizeof(u_int32_t));
	copied += (sizeof(struct in6_addr) + sizeof(u_int32_t));
	}
	IF_ADDR_UNLOCK(ifp);
	if (ifp0) /* we need search only on the specified IF */
	break;
	}

	if (allow_deprecated == 0 && ifp_dep != NULL) {
	ifp = ifp_dep;
	allow_deprecated = 1;

	goto again;
	}

	IFNET_RUNLOCK();

	return (copied);
	}

	/*
	* XXX almost dup'ed code with rip6_input.
	*/
	static int
	icmp6_rip6_input(struct mbuf **mp, int off)
	{
	INIT_VNET_INET(curvnet);
	INIT_VNET_INET6(curvnet);
	struct mbuf m = mp;
	struct ip6_hdr ip6 = mtod(m, struct ip6_hdr );
	struct inpcb *in6p;
	struct inpcb *last = NULL;
	struct sockaddr_in6 fromsa;
	struct icmp6_hdr *icmp6;
	struct mbuf *opts = NULL;

	#ifndef PULLDOWN_TEST
	/* this is assumed to be safe. */
	icmp6 = (struct icmp6_hdr *)((caddr_t)ip6 + off);
	#else
	IP6_EXTHDR_GET(icmp6, struct icmp6_hdr , m, off, sizeof(icmp6));
	if (icmp6 == NULL) {
	/* m is already reclaimed */
	return (IPPROTO_DONE);
	}
	#endif

	/*
	* XXX: the address may have embedded scope zone ID, which should be
	* hidden from applications.
	*/
	bzero(&fromsa, sizeof(fromsa));
	fromsa.sin6_family = AF_INET6;
	fromsa.sin6_len = sizeof(struct sockaddr_in6);
	fromsa.sin6_addr = ip6->ip6_src;
	if (sa6_recoverscope(&fromsa)) {
	m_freem(m);
	return (IPPROTO_DONE);
	}

	INP_INFO_RLOCK(&V_ripcbinfo);
	LIST_FOREACH(in6p, &V_ripcb, inp_list) {
	if ((in6p->inp_vflag & INP_IPV6) == 0)
	continue;
	if (in6p->inp_ip_p != IPPROTO_ICMPV6)
	continue;
	if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr) &&
	!IN6_ARE_ADDR_EQUAL(&in6p->in6p_laddr, &ip6->ip6_dst))
	continue;
	if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr) &&
	!IN6_ARE_ADDR_EQUAL(&in6p->in6p_faddr, &ip6->ip6_src))
	continue;
	INP_RLOCK(in6p);
	if (ICMP6_FILTER_WILLBLOCK(icmp6->icmp6_type,
	in6p->in6p_icmp6filt)) {
	INP_RUNLOCK(in6p);
	continue;
	}
	if (last != NULL) {
	struct mbuf *n = NULL;

	/*
	* Recent network drivers tend to allocate a single
	* mbuf cluster, rather than to make a couple of
	* mbufs without clusters. Also, since the IPv6 code
	* path tries to avoid m_pullup(), it is highly
	* probable that we still have an mbuf cluster here
	* even though the necessary length can be stored in an
	* mbuf's internal buffer.
	* Meanwhile, the default size of the receive socket
	* buffer for raw sockets is not so large. This means
	* the possibility of packet loss is relatively higher
	* than before. To avoid this scenario, we copy the
	* received data to a separate mbuf that does not use
	* a cluster, if possible.
	* XXX: it is better to copy the data after stripping
	* intermediate headers.
	*/
	if ((m->m_flags & M_EXT) && m->m_next == NULL &&
	m->m_len <= MHLEN) {
	MGET(n, M_DONTWAIT, m->m_type);
	if (n != NULL) {
	if (m_dup_pkthdr(n, m, M_NOWAIT)) {
	bcopy(m->m_data, n->m_data,
	m->m_len);
	n->m_len = m->m_len;
	} else {
	m_free(n);
	n = NULL;
	}
	}
	}
	if (n != NULL \|\|
	(n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
	if (last->inp_flags & INP_CONTROLOPTS)
	ip6_savecontrol(last, n, &opts);
	/* strip intermediate headers */
	m_adj(n, off);
	SOCKBUF_LOCK(&last->inp_socket->so_rcv);
	if (sbappendaddr_locked(
	&last->inp_socket->so_rcv,
	(struct sockaddr *)&fromsa, n, opts)
	== 0) {
	/* should notify about lost packet */
	m_freem(n);
	if (opts) {
	m_freem(opts);
	}
	SOCKBUF_UNLOCK(
	&last->inp_socket->so_rcv);
	} else
	sorwakeup_locked(last->inp_socket);
	opts = NULL;
	}
	INP_RUNLOCK(last);
	}
	last = in6p;
	}
	INP_INFO_RUNLOCK(&V_ripcbinfo);
	if (last != NULL) {
	if (last->inp_flags & INP_CONTROLOPTS)
	ip6_savecontrol(last, m, &opts);
	/* strip intermediate headers */
	m_adj(m, off);

	/* avoid using mbuf clusters if possible (see above) */
	if ((m->m_flags & M_EXT) && m->m_next == NULL &&
	m->m_len <= MHLEN) {
	struct mbuf *n;

	MGET(n, M_DONTWAIT, m->m_type);
	if (n != NULL) {
	if (m_dup_pkthdr(n, m, M_NOWAIT)) {
	bcopy(m->m_data, n->m_data, m->m_len);
	n->m_len = m->m_len;

	m_freem(m);
	m = n;
	} else {
	m_freem(n);
	n = NULL;
	}
	}
	}
	SOCKBUF_LOCK(&last->inp_socket->so_rcv);
	if (sbappendaddr_locked(&last->inp_socket->so_rcv,
	(struct sockaddr *)&fromsa, m, opts) == 0) {
	m_freem(m);
	if (opts)
	m_freem(opts);
	SOCKBUF_UNLOCK(&last->inp_socket->so_rcv);
	} else
	sorwakeup_locked(last->inp_socket);
	INP_RUNLOCK(last);
	} else {
	m_freem(m);
	IP6STAT_DEC(ip6s_delivered);
	}
	return IPPROTO_DONE;
	}

	/*
	* Reflect the ip6 packet back to the source.
	* OFF points to the icmp6 header, counted from the top of the mbuf.
	*/
	void
	icmp6_reflect(struct mbuf *m, size_t off)
	{
	INIT_VNET_INET6(curvnet);
	struct ip6_hdr *ip6;
	struct icmp6_hdr *icmp6;
	struct in6_ifaddr *ia = NULL;
	int plen;
	int type, code;
	struct ifnet *outif = NULL;
	struct in6_addr origdst, *src = NULL;

	/* too short to reflect */
	if (off < sizeof(struct ip6_hdr)) {
	nd6log((LOG_DEBUG,
	"sanity fail: off=%lx, sizeof(ip6)=%lx in %s:%d\n",
	(u_long)off, (u_long)sizeof(struct ip6_hdr),
	__FILE__, __LINE__));
	goto bad;
	}

	/*
	* If there are extra headers between IPv6 and ICMPv6, strip
	* off that header first.
	*/
	#ifdef DIAGNOSTIC
	if (sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) > MHLEN)
	panic("assumption failed in icmp6_reflect");
	#endif
	if (off > sizeof(struct ip6_hdr)) {
	size_t l;
	struct ip6_hdr nip6;

	l = off - sizeof(struct ip6_hdr);
	m_copydata(m, 0, sizeof(nip6), (caddr_t)&nip6);
	m_adj(m, l);
	l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
	if (m->m_len < l) {
	if ((m = m_pullup(m, l)) == NULL)
	return;
	}
	bcopy((caddr_t)&nip6, mtod(m, caddr_t), sizeof(nip6));
	} else /* off == sizeof(struct ip6_hdr) */ {
	size_t l;
	l = sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr);
	if (m->m_len < l) {
	if ((m = m_pullup(m, l)) == NULL)
	return;
	}
	}
	plen = m->m_pkthdr.len - sizeof(struct ip6_hdr);
	ip6 = mtod(m, struct ip6_hdr *);
	ip6->ip6_nxt = IPPROTO_ICMPV6;
	icmp6 = (struct icmp6_hdr *)(ip6 + 1);
	type = icmp6->icmp6_type; /* keep type for statistics */
	code = icmp6->icmp6_code; /* ditto. */

	origdst = ip6->ip6_dst;
	/*
	* ip6_input() drops a packet if its src is multicast.
	* So, the src is never multicast.
	*/
	ip6->ip6_dst = ip6->ip6_src;

	/*
	* If the incoming packet was addressed directly to us (i.e. unicast),
	* use dst as the src for the reply.
	* The IN6_IFF_NOTREADY case should be VERY rare, but is possible
	* (for example) when we encounter an error while forwarding procedure
	* destined to a duplicated address of ours.
	* Note that ip6_getdstifaddr() may fail if we are in an error handling
	* procedure of an outgoing packet of our own, in which case we need
	* to search in the ifaddr list.
	*/
	if (!IN6_IS_ADDR_MULTICAST(&origdst)) {
	if ((ia = ip6_getdstifaddr(m))) {
	if (!(ia->ia6_flags &
	(IN6_IFF_ANYCAST\|IN6_IFF_NOTREADY)))
	src = &ia->ia_addr.sin6_addr;
	} else {
	struct sockaddr_in6 d;

	bzero(&d, sizeof(d));
	d.sin6_family = AF_INET6;
	d.sin6_len = sizeof(d);
	d.sin6_addr = origdst;
	ia = (struct in6_ifaddr *)
	ifa_ifwithaddr((struct sockaddr *)&d);
	if (ia &&
	!(ia->ia6_flags &
	(IN6_IFF_ANYCAST\|IN6_IFF_NOTREADY))) {
	src = &ia->ia_addr.sin6_addr;
	}
	}
	}

	if (src == NULL) {
	int e;
	struct sockaddr_in6 sin6;
	struct route_in6 ro;

	/*
	* This case matches to multicasts, our anycast, or unicasts
	* that we do not own. Select a source address based on the
	* source address of the erroneous packet.
	*/
	bzero(&sin6, sizeof(sin6));
	sin6.sin6_family = AF_INET6;
	sin6.sin6_len = sizeof(sin6);
	sin6.sin6_addr = ip6->ip6_dst; /* zone ID should be embedded */

	bzero(&ro, sizeof(ro));
	src = in6_selectsrc(&sin6, NULL, NULL, &ro, NULL, &outif, &e);
	if (ro.ro_rt)
	RTFREE(ro.ro_rt); /* XXX: we could use this */
	if (src == NULL) {
	char ip6buf[INET6_ADDRSTRLEN];
	nd6log((LOG_DEBUG,
	"icmp6_reflect: source can't be determined: "
	"dst=%s, error=%d\n",
	ip6_sprintf(ip6buf, &sin6.sin6_addr), e));
	goto bad;
	}
	}

	ip6->ip6_src = *src;
	ip6->ip6_flow = 0;
	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
	ip6->ip6_vfc \|= IPV6_VERSION;
	ip6->ip6_nxt = IPPROTO_ICMPV6;
	if (outif)
	ip6->ip6_hlim = ND_IFINFO(outif)->chlim;
	else if (m->m_pkthdr.rcvif) {
	/* XXX: This may not be the outgoing interface */
	ip6->ip6_hlim = ND_IFINFO(m->m_pkthdr.rcvif)->chlim;
	} else
	ip6->ip6_hlim = V_ip6_defhlim;

	icmp6->icmp6_cksum = 0;
	icmp6->icmp6_cksum = in6_cksum(m, IPPROTO_ICMPV6,
	sizeof(struct ip6_hdr), plen);

	/*
	* XXX option handling
	*/

	m->m_flags &= ~(M_BCAST\|M_MCAST);

	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
	if (outif)
	icmp6_ifoutstat_inc(outif, type, code);

	if (ia != NULL)
	ifa_free(&ia->ia_ifa);
	return;

	bad:
	if (ia != NULL)
	ifa_free(&ia->ia_ifa);
	m_freem(m);
	return;
	}

	void
	icmp6_fasttimo(void)
	{

	mld_fasttimo();
	}

	void
	icmp6_slowtimo(void)
	{

	mld_slowtimo();
	}

	static const char *
	icmp6_redirect_diag(struct in6_addr src6, struct in6_addr dst6,
	struct in6_addr *tgt6)
	{
	static char buf[1024];
	char ip6bufs[INET6_ADDRSTRLEN];
	char ip6bufd[INET6_ADDRSTRLEN];
	char ip6buft[INET6_ADDRSTRLEN];
	snprintf(buf, sizeof(buf), "(src=%s dst=%s tgt=%s)",
	ip6_sprintf(ip6bufs, src6), ip6_sprintf(ip6bufd, dst6),
	ip6_sprintf(ip6buft, tgt6));
	return buf;
	}

	void
	icmp6_redirect_input(struct mbuf *m, int off)
	{
	INIT_VNET_INET6(curvnet);
	struct ifnet *ifp;
	struct ip6_hdr ip6 = mtod(m, struct ip6_hdr );
	struct nd_redirect *nd_rd;
	int icmp6len = ntohs(ip6->ip6_plen);
	char *lladdr = NULL;
	int lladdrlen = 0;
	u_char *redirhdr = NULL;
	int redirhdrlen = 0;
	struct rtentry *rt = NULL;
	int is_router;
	int is_onlink;
	struct in6_addr src6 = ip6->ip6_src;
	struct in6_addr redtgt6;
	struct in6_addr reddst6;
	union nd_opts ndopts;
	char ip6buf[INET6_ADDRSTRLEN];

	if (!m)
	return;

	ifp = m->m_pkthdr.rcvif;

	if (!ifp)
	return;

	/* XXX if we are router, we don't update route by icmp6 redirect */
	if (V_ip6_forwarding)
	goto freeit;
	if (!V_icmp6_rediraccept)
	goto freeit;

	#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, icmp6len,);
	nd_rd = (struct nd_redirect *)((caddr_t)ip6 + off);
	#else
	IP6_EXTHDR_GET(nd_rd, struct nd_redirect *, m, off, icmp6len);
	if (nd_rd == NULL) {
	ICMP6STAT_INC(icp6s_tooshort);
	return;
	}
	#endif
	redtgt6 = nd_rd->nd_rd_target;
	reddst6 = nd_rd->nd_rd_dst;

	if (in6_setscope(&redtgt6, m->m_pkthdr.rcvif, NULL) \|\|
	in6_setscope(&reddst6, m->m_pkthdr.rcvif, NULL)) {
	goto freeit;
	}

	/* validation */
	if (!IN6_IS_ADDR_LINKLOCAL(&src6)) {
	nd6log((LOG_ERR,
	"ICMP6 redirect sent from %s rejected; "
	"must be from linklocal\n",
	ip6_sprintf(ip6buf, &src6)));
	goto bad;
	}
	if (ip6->ip6_hlim != 255) {
	nd6log((LOG_ERR,
	"ICMP6 redirect sent from %s rejected; "
	"hlim=%d (must be 255)\n",
	ip6_sprintf(ip6buf, &src6), ip6->ip6_hlim));
	goto bad;
	}
	{
	/* ip6->ip6_src must be equal to gw for icmp6->icmp6_reddst */
	struct sockaddr_in6 sin6;
	struct in6_addr *gw6;

	bzero(&sin6, sizeof(sin6));
	sin6.sin6_family = AF_INET6;
	sin6.sin6_len = sizeof(struct sockaddr_in6);
	bcopy(&reddst6, &sin6.sin6_addr, sizeof(reddst6));
	rt = rtalloc1((struct sockaddr *)&sin6, 0, 0UL);
	if (rt) {
	if (rt->rt_gateway == NULL \|\|
	rt->rt_gateway->sa_family != AF_INET6) {
	nd6log((LOG_ERR,
	"ICMP6 redirect rejected; no route "
	"with inet6 gateway found for redirect dst: %s\n",
	icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
	RTFREE_LOCKED(rt);
	goto bad;
	}

	gw6 = &(((struct sockaddr_in6 *)rt->rt_gateway)->sin6_addr);
	if (bcmp(&src6, gw6, sizeof(struct in6_addr)) != 0) {
	nd6log((LOG_ERR,
	"ICMP6 redirect rejected; "
	"not equal to gw-for-src=%s (must be same): "
	"%s\n",
	ip6_sprintf(ip6buf, gw6),
	icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
	RTFREE_LOCKED(rt);
	goto bad;
	}
	} else {
	nd6log((LOG_ERR,
	"ICMP6 redirect rejected; "
	"no route found for redirect dst: %s\n",
	icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
	goto bad;
	}
	RTFREE_LOCKED(rt);
	rt = NULL;
	}
	if (IN6_IS_ADDR_MULTICAST(&reddst6)) {
	nd6log((LOG_ERR,
	"ICMP6 redirect rejected; "
	"redirect dst must be unicast: %s\n",
	icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
	goto bad;
	}

	is_router = is_onlink = 0;
	if (IN6_IS_ADDR_LINKLOCAL(&redtgt6))
	is_router = 1; /* router case */
	if (bcmp(&redtgt6, &reddst6, sizeof(redtgt6)) == 0)
	is_onlink = 1; /* on-link destination case */
	if (!is_router && !is_onlink) {
	nd6log((LOG_ERR,
	"ICMP6 redirect rejected; "
	"neither router case nor onlink case: %s\n",
	icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
	goto bad;
	}
	/* validation passed */

	icmp6len -= sizeof(*nd_rd);
	nd6_option_init(nd_rd + 1, icmp6len, &ndopts);
	if (nd6_options(&ndopts) < 0) {
	nd6log((LOG_INFO, "icmp6_redirect_input: "
	"invalid ND option, rejected: %s\n",
	icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
	/* nd6_options have incremented stats */
	goto freeit;
	}

	if (ndopts.nd_opts_tgt_lladdr) {
	lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
	lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
	}

	if (ndopts.nd_opts_rh) {
	redirhdrlen = ndopts.nd_opts_rh->nd_opt_rh_len;
	redirhdr = (u_char )(ndopts.nd_opts_rh + 1); / xxx */
	}

	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
	nd6log((LOG_INFO,
	"icmp6_redirect_input: lladdrlen mismatch for %s "
	"(if %d, icmp6 packet %d): %s\n",
	ip6_sprintf(ip6buf, &redtgt6),
	ifp->if_addrlen, lladdrlen - 2,
	icmp6_redirect_diag(&src6, &reddst6, &redtgt6)));
	goto bad;
	}

	/* RFC 2461 8.3 */
	nd6_cache_lladdr(ifp, &redtgt6, lladdr, lladdrlen, ND_REDIRECT,
	is_onlink ? ND_REDIRECT_ONLINK : ND_REDIRECT_ROUTER);

	if (!is_onlink) { /* better router case. perform rtredirect. */
	/* perform rtredirect */
	struct sockaddr_in6 sdst;
	struct sockaddr_in6 sgw;
	struct sockaddr_in6 ssrc;

	bzero(&sdst, sizeof(sdst));
	bzero(&sgw, sizeof(sgw));
	bzero(&ssrc, sizeof(ssrc));
	sdst.sin6_family = sgw.sin6_family = ssrc.sin6_family = AF_INET6;
	sdst.sin6_len = sgw.sin6_len = ssrc.sin6_len =
	sizeof(struct sockaddr_in6);
	bcopy(&redtgt6, &sgw.sin6_addr, sizeof(struct in6_addr));
	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
	bcopy(&src6, &ssrc.sin6_addr, sizeof(struct in6_addr));
	rtredirect((struct sockaddr )&sdst, (struct sockaddr )&sgw,
	(struct sockaddr *)NULL, RTF_GATEWAY \| RTF_HOST,
	(struct sockaddr *)&ssrc);
	}
	/* finally update cached route in each socket via pfctlinput */
	{
	struct sockaddr_in6 sdst;

	bzero(&sdst, sizeof(sdst));
	sdst.sin6_family = AF_INET6;
	sdst.sin6_len = sizeof(struct sockaddr_in6);
	bcopy(&reddst6, &sdst.sin6_addr, sizeof(struct in6_addr));
	pfctlinput(PRC_REDIRECT_HOST, (struct sockaddr *)&sdst);
	#ifdef IPSEC
	key_sa_routechange((struct sockaddr *)&sdst);
	#endif /* IPSEC */
	}

	freeit:
	m_freem(m);
	return;

	bad:
	ICMP6STAT_INC(icp6s_badredirect);
	m_freem(m);
	}

	void
	icmp6_redirect_output(struct mbuf m0, struct rtentry rt)
	{
	INIT_VNET_INET6(curvnet);
	struct ifnet ifp; / my outgoing interface */
	struct in6_addr *ifp_ll6;
	struct in6_addr *router_ll6;
	struct ip6_hdr sip6; / m0 as struct ip6_hdr */
	struct mbuf m = NULL; / newly allocated one */
	struct ip6_hdr ip6; / m as struct ip6_hdr */
	struct nd_redirect *nd_rd;
	struct llentry *ln = NULL;
	size_t maxlen;
	u_char *p;
	struct ifnet *outif = NULL;
	struct sockaddr_in6 src_sa;

	icmp6_errcount(&V_icmp6stat.icp6s_outerrhist, ND_REDIRECT, 0);

	/* if we are not router, we don't send icmp6 redirect */
	if (!V_ip6_forwarding)
	goto fail;

	/* sanity check */
	if (!m0 \|\| !rt \|\| !(rt->rt_flags & RTF_UP) \|\| !(ifp = rt->rt_ifp))
	goto fail;

	/*
	* Address check:
	* the source address must identify a neighbor, and
	* the destination address must not be a multicast address
	* [RFC 2461, sec 8.2]
	*/
	sip6 = mtod(m0, struct ip6_hdr *);
	bzero(&src_sa, sizeof(src_sa));
	src_sa.sin6_family = AF_INET6;
	src_sa.sin6_len = sizeof(src_sa);
	src_sa.sin6_addr = sip6->ip6_src;
	if (nd6_is_addr_neighbor(&src_sa, ifp) == 0)
	goto fail;
	if (IN6_IS_ADDR_MULTICAST(&sip6->ip6_dst))
	goto fail; /* what should we do here? */

	/* rate limit */
	if (icmp6_ratelimit(&sip6->ip6_src, ND_REDIRECT, 0))
	goto fail;

	/*
	* Since we are going to append up to 1280 bytes (= IPV6_MMTU),
	* we almost always ask for an mbuf cluster for simplicity.
	* (MHLEN < IPV6_MMTU is almost always true)
	*/
	#if IPV6_MMTU >= MCLBYTES
	# error assumption failed about IPV6_MMTU and MCLBYTES
	#endif
	MGETHDR(m, M_DONTWAIT, MT_HEADER);
	if (m && IPV6_MMTU >= MHLEN)
	MCLGET(m, M_DONTWAIT);
	if (!m)
	goto fail;
	m->m_pkthdr.rcvif = NULL;
	m->m_len = 0;
	maxlen = M_TRAILINGSPACE(m);
	maxlen = min(IPV6_MMTU, maxlen);
	/* just for safety */
	if (maxlen < sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr) +
	((sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7)) {
	goto fail;
	}

	{
	/* get ip6 linklocal address for ifp(my outgoing interface). */
	struct in6_ifaddr *ia;
	if ((ia = in6ifa_ifpforlinklocal(ifp,
	IN6_IFF_NOTREADY\|
	IN6_IFF_ANYCAST)) == NULL)
	goto fail;
	ifp_ll6 = &ia->ia_addr.sin6_addr;
	/* XXXRW: reference released prematurely. */
	ifa_free(&ia->ia_ifa);
	}

	/* get ip6 linklocal address for the router. */
	if (rt->rt_gateway && (rt->rt_flags & RTF_GATEWAY)) {
	struct sockaddr_in6 *sin6;
	sin6 = (struct sockaddr_in6 *)rt->rt_gateway;
	router_ll6 = &sin6->sin6_addr;
	if (!IN6_IS_ADDR_LINKLOCAL(router_ll6))
	router_ll6 = (struct in6_addr *)NULL;
	} else
	router_ll6 = (struct in6_addr *)NULL;

	/* ip6 */
	ip6 = mtod(m, struct ip6_hdr *);
	ip6->ip6_flow = 0;
	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
	ip6->ip6_vfc \|= IPV6_VERSION;
	/* ip6->ip6_plen will be set later */
	ip6->ip6_nxt = IPPROTO_ICMPV6;
	ip6->ip6_hlim = 255;
	/* ip6->ip6_src must be linklocal addr for my outgoing if. */
	bcopy(ifp_ll6, &ip6->ip6_src, sizeof(struct in6_addr));
	bcopy(&sip6->ip6_src, &ip6->ip6_dst, sizeof(struct in6_addr));

	/* ND Redirect */
	nd_rd = (struct nd_redirect *)(ip6 + 1);
	nd_rd->nd_rd_type = ND_REDIRECT;
	nd_rd->nd_rd_code = 0;
	nd_rd->nd_rd_reserved = 0;
	if (rt->rt_flags & RTF_GATEWAY) {
	/*
	* nd_rd->nd_rd_target must be a link-local address in
	* better router cases.
	*/
	if (!router_ll6)
	goto fail;
	bcopy(router_ll6, &nd_rd->nd_rd_target,
	sizeof(nd_rd->nd_rd_target));
	bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
	sizeof(nd_rd->nd_rd_dst));
	} else {
	/* make sure redtgt == reddst */
	bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_target,
	sizeof(nd_rd->nd_rd_target));
	bcopy(&sip6->ip6_dst, &nd_rd->nd_rd_dst,
	sizeof(nd_rd->nd_rd_dst));
	}

	p = (u_char *)(nd_rd + 1);

	if (!router_ll6)
	goto nolladdropt;

	{
	/* target lladdr option */
	int len;
	struct nd_opt_hdr *nd_opt;
	char *lladdr;

	IF_AFDATA_LOCK(ifp);
	ln = nd6_lookup(router_ll6, 0, ifp);
	IF_AFDATA_UNLOCK(ifp);
	if (ln == NULL)
	goto nolladdropt;

	len = sizeof(*nd_opt) + ifp->if_addrlen;
	len = (len + 7) & ~7; /* round by 8 */
	/* safety check */
	if (len + (p - (u_char *)ip6) > maxlen)
	goto nolladdropt;

	if (ln->la_flags & LLE_VALID) {
	nd_opt = (struct nd_opt_hdr *)p;
	nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
	nd_opt->nd_opt_len = len >> 3;
	lladdr = (char *)(nd_opt + 1);
	bcopy(&ln->ll_addr, lladdr, ifp->if_addrlen);
	p += len;
	}
	}
	nolladdropt:
	if (ln != NULL)
	LLE_RUNLOCK(ln);

	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;

	/* just to be safe */
	#ifdef M_DECRYPTED /not openbsd/
	if (m0->m_flags & M_DECRYPTED)
	goto noredhdropt;
	#endif
	if (p - (u_char *)ip6 > maxlen)
	goto noredhdropt;

	{
	/* redirected header option */
	int len;
	struct nd_opt_rd_hdr *nd_opt_rh;

	/*
	* compute the maximum size for icmp6 redirect header option.
	* XXX room for auth header?
	*/
	len = maxlen - (p - (u_char *)ip6);
	len &= ~7;

	/* This is just for simplicity. */
	if (m0->m_pkthdr.len != m0->m_len) {
	if (m0->m_next) {
	m_freem(m0->m_next);
	m0->m_next = NULL;
	}
	m0->m_pkthdr.len = m0->m_len;
	}

	/*
	* Redirected header option spec (RFC2461 4.6.3) talks nothing
	* about padding/truncate rule for the original IP packet.
	* From the discussion on IPv6imp in Feb 1999,
	* the consensus was:
	* - "attach as much as possible" is the goal
	* - pad if not aligned (original size can be guessed by
	* original ip6 header)
	* Following code adds the padding if it is simple enough,
	* and truncates if not.
	*/
	if (m0->m_next \|\| m0->m_pkthdr.len != m0->m_len)
	panic("assumption failed in %s:%d", __FILE__,
	__LINE__);

	if (len - sizeof(*nd_opt_rh) < m0->m_pkthdr.len) {
	/* not enough room, truncate */
	m0->m_pkthdr.len = m0->m_len = len -
	sizeof(*nd_opt_rh);
	} else {
	/* enough room, pad or truncate */
	size_t extra;

	extra = m0->m_pkthdr.len % 8;
	if (extra) {
	/* pad if easy enough, truncate if not */
	if (8 - extra <= M_TRAILINGSPACE(m0)) {
	/* pad */
	m0->m_len += (8 - extra);
	m0->m_pkthdr.len += (8 - extra);
	} else {
	/* truncate */
	m0->m_pkthdr.len -= extra;
	m0->m_len -= extra;
	}
	}
	len = m0->m_pkthdr.len + sizeof(*nd_opt_rh);
	m0->m_pkthdr.len = m0->m_len = len -
	sizeof(*nd_opt_rh);
	}

	nd_opt_rh = (struct nd_opt_rd_hdr *)p;
	bzero(nd_opt_rh, sizeof(*nd_opt_rh));
	nd_opt_rh->nd_opt_rh_type = ND_OPT_REDIRECTED_HEADER;
	nd_opt_rh->nd_opt_rh_len = len >> 3;
	p += sizeof(*nd_opt_rh);
	m->m_pkthdr.len = m->m_len = p - (u_char *)ip6;

	/* connect m0 to m */
	m_tag_delete_chain(m0, NULL);
	m0->m_flags &= ~M_PKTHDR;
	m->m_next = m0;
	m->m_pkthdr.len = m->m_len + m0->m_len;
	m0 = NULL;
	}
	noredhdropt:;
	if (m0) {
	m_freem(m0);
	m0 = NULL;
	}

	/* XXX: clear embedded link IDs in the inner header */
	in6_clearscope(&sip6->ip6_src);
	in6_clearscope(&sip6->ip6_dst);
	in6_clearscope(&nd_rd->nd_rd_target);
	in6_clearscope(&nd_rd->nd_rd_dst);

	ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));

	nd_rd->nd_rd_cksum = 0;
	nd_rd->nd_rd_cksum = in6_cksum(m, IPPROTO_ICMPV6,
	sizeof(*ip6), ntohs(ip6->ip6_plen));

	/* send the packet to outside... */
	ip6_output(m, NULL, NULL, 0, NULL, &outif, NULL);
	if (outif) {
	icmp6_ifstat_inc(outif, ifs6_out_msg);
	icmp6_ifstat_inc(outif, ifs6_out_redirect);
	}
	ICMP6STAT_INC(icp6s_outhist[ND_REDIRECT]);

	return;

	fail:
	if (m)
	m_freem(m);
	if (m0)
	m_freem(m0);
	}

	/*
	* ICMPv6 socket option processing.
	*/
	int
	icmp6_ctloutput(struct socket so, struct sockopt sopt)
	{
	int error = 0;
	int optlen;
	struct inpcb *inp = sotoinpcb(so);
	int level, op, optname;

	if (sopt) {
	level = sopt->sopt_level;
	op = sopt->sopt_dir;
	optname = sopt->sopt_name;
	optlen = sopt->sopt_valsize;
	} else
	level = op = optname = optlen = 0;

	if (level != IPPROTO_ICMPV6) {
	return EINVAL;
	}

	switch (op) {
	case PRCO_SETOPT:
	switch (optname) {
	case ICMP6_FILTER:
	{
	struct icmp6_filter ic6f;

	if (optlen != sizeof(ic6f)) {
	error = EMSGSIZE;
	break;
	}
	error = sooptcopyin(sopt, &ic6f, optlen, optlen);
	if (error == 0) {
	INP_WLOCK(inp);
	*inp->in6p_icmp6filt = ic6f;
	INP_WUNLOCK(inp);
	}
	break;
	}

	default:
	error = ENOPROTOOPT;
	break;
	}
	break;

	case PRCO_GETOPT:
	switch (optname) {
	case ICMP6_FILTER:
	{
	struct icmp6_filter ic6f;

	INP_RLOCK(inp);
	ic6f = *inp->in6p_icmp6filt;
	INP_RUNLOCK(inp);
	error = sooptcopyout(sopt, &ic6f, sizeof(ic6f));
	break;
	}

	default:
	error = ENOPROTOOPT;
	break;
	}
	break;
	}

	return (error);
	}

	/*
	* Perform rate limit check.
	* Returns 0 if it is okay to send the icmp6 packet.
	* Returns 1 if the router SHOULD NOT send this icmp6 packet due to rate
	* limitation.
	*
	* XXX per-destination/type check necessary?
	*
	* dst - not used at this moment
	* type - not used at this moment
	* code - not used at this moment
	*/
	static int
	icmp6_ratelimit(const struct in6_addr *dst, const int type,
	const int code)
	{
	INIT_VNET_INET6(curvnet);
	int ret;

	ret = 0; /* okay to send */

	/* PPS limit */
	if (!ppsratecheck(&V_icmp6errppslim_last, &V_icmp6errpps_count,
	V_icmp6errppslim)) {
	/* The packet is subject to rate limit */
	ret++;
	}

	return ret;
	}

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