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File: [cvs.NetBSD.org] / src / sys / netinet6 / ip6_input.c (download)

Revision 1.35, Sat Feb 10 04:14:28 2001 UTC (13 years, 7 months ago) by itojun
Branch: MAIN
Changes since 1.34: +134 -152 lines

to sync with kame better, (1) remove register declaration for variables,
(2) sync whitespaces, (3) update comments. (4) bring in some of portability
and logging enhancements.  no functional changes here.

/*	$NetBSD: ip6_input.c,v 1.35 2001/02/10 04:14:28 itojun Exp $	*/
/*	$KAME: ip6_input.c,v 1.174 2001/02/09 06:17:41 jinmei Exp $	*/

/*
 * 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.
 */

/*
 * 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 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_input.c	8.2 (Berkeley) 1/4/94
 */

#include "opt_inet.h"
#include "opt_ipsec.h"
#include "opt_pfil_hooks.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/proc.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <net/netisr.h>
#ifdef PFIL_HOOKS
#include <net/pfil.h>
#endif

#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifdef INET
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#endif /*INET*/
#include <netinet/ip6.h>
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/nd6.h>
#include <netinet6/in6_prefix.h>

#include <netinet6/ip6protosw.h>

/* we need it for NLOOP. */
#include "loop.h"
#include "faith.h"

#include "gif.h"
#include "bpfilter.h"

#include <net/net_osdep.h>

extern struct domain inet6domain;

u_char ip6_protox[IPPROTO_MAX];
static int ip6qmaxlen = IFQ_MAXLEN;
struct in6_ifaddr *in6_ifaddr;
struct ifqueue ip6intrq;

extern struct ifnet loif[NLOOP];
int ip6_forward_srcrt;			/* XXX */
int ip6_sourcecheck;			/* XXX */
int ip6_sourcecheck_interval;		/* XXX */

#ifdef PFIL_HOOKS
struct pfil_head inet6_pfil_hook;
#endif

struct ip6stat ip6stat;

static void ip6_init2 __P((void *));

static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *));

/*
 * IP6 initialization: fill in IP6 protocol switch table.
 * All protocols not implemented in kernel go to raw IP6 protocol handler.
 */
void
ip6_init()
{
	struct ip6protosw *pr;
	int i;
	struct timeval tv;

	pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
	if (pr == 0)
		panic("ip6_init");
	for (i = 0; i < IPPROTO_MAX; i++)
		ip6_protox[i] = pr - inet6sw;
	for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
	    pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
		if (pr->pr_domain->dom_family == PF_INET6 &&
		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW)
			ip6_protox[pr->pr_protocol] = pr - inet6sw;
	ip6intrq.ifq_maxlen = ip6qmaxlen;
	nd6_init();
	frag6_init();
	/*
	 * in many cases, random() here does NOT return random number
	 * as initialization during bootstrap time occur in fixed order.
	 */
	microtime(&tv);
	ip6_flow_seq = random() ^ tv.tv_usec;

	ip6_init2((void *)0);

#ifdef PFIL_HOOKS
	/* Register our Packet Filter hook. */
	inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
	inet6_pfil_hook.ph_af   = AF_INET6;
	i = pfil_head_register(&inet6_pfil_hook);
	if (i != 0)
		printf("ip6_init: WARNING: unable to register pfil hook, "
		    "error %d\n", i);
#endif /* PFIL_HOOKS */
}

static void
ip6_init2(dummy)
	void *dummy;
{
	/*
	 * to route local address of p2p link to loopback,
	 * assign loopback address first.
	 */
	in6_ifattach(&loif[0], NULL);

	/* nd6_timer_init */
	callout_init(&nd6_timer_ch);
	callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);
	/* router renumbering prefix list maintenance */
	callout_init(&in6_rr_timer_ch);
	callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL);
}

/*
 * IP6 input interrupt handling. Just pass the packet to ip6_input.
 */
void
ip6intr()
{
	int s;
	struct mbuf *m;

	for (;;) {
		s = splimp();
		IF_DEQUEUE(&ip6intrq, m);
		splx(s);
		if (m == 0)
			return;
		ip6_input(m);
	}
}

extern struct	route_in6 ip6_forward_rt;

void
ip6_input(m)
	struct mbuf *m;
{
	struct ip6_hdr *ip6;
	int off = sizeof(struct ip6_hdr), nest;
	u_int32_t plen;
	u_int32_t rtalert = ~0;
	int nxt, ours = 0;
	struct ifnet *deliverifp = NULL;

#ifdef IPSEC
	/*
	 * should the inner packet be considered authentic?
	 * see comment in ah4_input().
	 */
	if (m) {
		m->m_flags &= ~M_AUTHIPHDR;
		m->m_flags &= ~M_AUTHIPDGM;
	}
#endif

	/*
	 * mbuf statistics by kazu
	 */
	if (m->m_flags & M_EXT) {
		if (m->m_next)
			ip6stat.ip6s_mext2m++;
		else
			ip6stat.ip6s_mext1++;
	} else {
		if (m->m_next) {
			if (m->m_flags & M_LOOP) {
				ip6stat.ip6s_m2m[loif[0].if_index]++;	/*XXX*/
			} else if (m->m_pkthdr.rcvif->if_index <= 31)
				ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
			else
				ip6stat.ip6s_m2m[0]++;
		} else
			ip6stat.ip6s_m1++;
	}

	in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
	ip6stat.ip6s_total++;

#ifndef PULLDOWN_TEST
	/* XXX is the line really necessary? */
	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/);
#endif

	if (m->m_len < sizeof(struct ip6_hdr)) {
		struct ifnet *inifp;
		inifp = m->m_pkthdr.rcvif;
		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) {
			ip6stat.ip6s_toosmall++;
			in6_ifstat_inc(inifp, ifs6_in_hdrerr);
			return;
		}
	}

	ip6 = mtod(m, struct ip6_hdr *);

	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
		ip6stat.ip6s_badvers++;
		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
		goto bad;
	}

#ifdef PFIL_HOOKS
	/*
	 * Run through list of hooks for input packets.  If there are any
	 * filters which require that additional packets in the flow are
	 * not fast-forwarded, they must clear the M_CANFASTFWD flag.
	 * Note that filters must _never_ set this flag, as another filter
	 * in the list may have previously cleared it.
	 */
	if (pfil_run_hooks(&inet6_pfil_hook, &m, m->m_pkthdr.rcvif,
			   PFIL_IN) != 0)
		return;
	if (m == NULL)
		return;
	ip6 = mtod(m, struct ip6_hdr *);
#endif /* PFIL_HOOKS */


	ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;

#ifdef ALTQ
	/* XXX Temporary until ALTQ is changed to use a pfil hook */
	if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
		/* packet is dropped by traffic conditioner */
		return;
	}
#endif

	/*
	 * Scope check
	 */
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
		ip6stat.ip6s_badscope++;
		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
		goto bad;
	}
	/*
	 * The following check is not documented in the spec.  Malicious party
	 * may be able to use IPv4 mapped addr to confuse tcp/udp stack and
	 * bypass security checks (act as if it was from 127.0.0.1 by using
	 * IPv6 src ::ffff:127.0.0.1).	Be cautious.
	 *
	 * This check chokes if we are in SIIT cloud.  As none of BSDs support
	 * IPv4-less kernel compilation, we cannot support SIIT environment
	 * at all.  So, it makes more sense for us to reject any malicious
	 * packets for non-SIIT environment, than try to do a partical support
	 * for SIIT environment.
	 */
	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
		ip6stat.ip6s_badscope++;
		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
		goto bad;
	}
#if 0
	/*
	 * Reject packets with IPv4 compatible addresses (auto tunnel).
	 *
	 * The code forbids auto tunnel relay case in RFC1933 (the check is
	 * stronger than RFC1933).  We may want to re-enable it if mech-xx
	 * is revised to forbid relaying case.
	 */
	if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
		ip6stat.ip6s_badscope++;
		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
		goto bad;
	}
#endif

	if (IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) ||
	    IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) {
		if (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) {
			ours = 1;
			deliverifp = m->m_pkthdr.rcvif;
			goto hbhcheck;
		} else {
			ip6stat.ip6s_badscope++;
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
			goto bad;
		}
	}

#ifndef FAKE_LOOPBACK_IF
	if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0)
#else
	if (1)
#endif
	{
		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src))
			ip6->ip6_src.s6_addr16[1]
				= htons(m->m_pkthdr.rcvif->if_index);
		if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst))
			ip6->ip6_dst.s6_addr16[1]
				= htons(m->m_pkthdr.rcvif->if_index);
	}

	/*
	 * XXX we need this since we do not have "goto ours" hack route
	 * for some of our ifaddrs on loopback interface.
	 * we should correct it by changing in6_ifattach to install
	 * "goto ours" hack route.
	 */
	if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0) {
		if (IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) {
			ours = 1;
			deliverifp = m->m_pkthdr.rcvif;
			goto hbhcheck;
		}
	}

	/*
	 * Multicast check
	 */
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
	  	struct	in6_multi *in6m = 0;

		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
		/*
		 * See if we belong to the destination multicast group on the
		 * arrival interface.
		 */
		IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m);
		if (in6m)
			ours = 1;
		else if (!ip6_mrouter) {
			ip6stat.ip6s_notmember++;
			ip6stat.ip6s_cantforward++;
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
			goto bad;
		}
		deliverifp = m->m_pkthdr.rcvif;
		goto hbhcheck;
	}

	/*
	 *  Unicast check
	 */
	if (ip6_forward_rt.ro_rt != NULL &&
	    (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && 
	    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
			       &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr))
		ip6stat.ip6s_forward_cachehit++;
	else {
		struct sockaddr_in6 *dst6;

		if (ip6_forward_rt.ro_rt) {
			/* route is down or destination is different */
			ip6stat.ip6s_forward_cachemiss++;
			RTFREE(ip6_forward_rt.ro_rt);
			ip6_forward_rt.ro_rt = 0;
		}

		bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6));
		dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst;
		dst6->sin6_len = sizeof(struct sockaddr_in6);
		dst6->sin6_family = AF_INET6;
		dst6->sin6_addr = ip6->ip6_dst;

		rtalloc((struct route *)&ip6_forward_rt);
	}

#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))

	/*
	 * Accept the packet if the forwarding interface to the destination
	 * according to the routing table is the loopback interface,
	 * unless the associated route has a gateway.
	 * Note that this approach causes to accept a packet if there is a
	 * route to the loopback interface for the destination of the packet.
	 * But we think it's even useful in some situations, e.g. when using
	 * a special daemon which wants to intercept the packet.
	 */
	if (ip6_forward_rt.ro_rt &&
	    (ip6_forward_rt.ro_rt->rt_flags &
	     (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
#if 0
	    /*
	     * The check below is redundant since the comparison of
	     * the destination and the key of the rtentry has
	     * already done through looking up the routing table.
	     */
	    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
			       &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) &&
#endif
	    ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) {
		struct in6_ifaddr *ia6 =
			(struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa;
		if (ia6->ia6_flags & IN6_IFF_ANYCAST)
			m->m_flags |= M_ANYCAST6;
		/*
		 * packets to a tentative, duplicated, or somehow invalid
		 * address must not be accepted.
		 */
		if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
			/* this address is ready */
			ours = 1;
			deliverifp = ia6->ia_ifp;	/* correct? */
			goto hbhcheck;
		} else {
			/* address is not ready, so discard the packet. */
			nd6log((LOG_INFO,
			    "ip6_input: packet to an unready address %s->%s\n",
			    ip6_sprintf(&ip6->ip6_src),
			    ip6_sprintf(&ip6->ip6_dst)));

			goto bad;
		}
	}

	/*
	 * FAITH(Firewall Aided Internet Translator)
	 */
#if defined(NFAITH) && 0 < NFAITH
	if (ip6_keepfaith) {
		if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp
		 && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) {
			/* XXX do we need more sanity checks? */
			ours = 1;
			deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /*faith*/
			goto hbhcheck;
		}
	}
#endif

#if 0
    {
	/*
	 * Last resort: check in6_ifaddr for incoming interface.
	 * The code is here until I update the "goto ours hack" code above
	 * working right.
	 */
	struct ifaddr *ifa;
	for (ifa = m->m_pkthdr.rcvif->if_addrlist.tqh_first;
	     ifa;
	     ifa = ifa->ifa_list.tqe_next) {
		if (ifa->ifa_addr == NULL)
			continue;	/* just for safety */
		if (ifa->ifa_addr->sa_family != AF_INET6)
			continue;
		if (IN6_ARE_ADDR_EQUAL(IFA_IN6(ifa), &ip6->ip6_dst)) {
			ours = 1;
			deliverifp = ifa->ifa_ifp;
			goto hbhcheck;
		}
	}
    }
#endif

	/*
	 * Now there is no reason to process the packet if it's not our own
	 * and we're not a router.
	 */
	if (!ip6_forwarding) {
		ip6stat.ip6s_cantforward++;
		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
		goto bad;
	}

  hbhcheck:
	/*
	 * Process Hop-by-Hop options header if it's contained.
	 * m may be modified in ip6_hopopts_input().
	 * If a JumboPayload option is included, plen will also be modified.
	 */
	plen = (u_int32_t)ntohs(ip6->ip6_plen);
	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
		struct ip6_hbh *hbh;

		if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
#if 0	/*touches NULL pointer*/
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
#endif
			return;	/* m have already been freed */
		}

		/* adjust pointer */
		ip6 = mtod(m, struct ip6_hdr *);

		/*
		 * if the payload length field is 0 and the next header field  
		 * indicates Hop-by-Hop Options header, then a Jumbo Payload
		 * option MUST be included.
		 */
		if (ip6->ip6_plen == 0 && plen == 0) {
			/*
			 * Note that if a valid jumbo payload option is
			 * contained, ip6_hoptops_input() must set a valid
			 * (non-zero) payload length to the variable plen. 
			 */
			ip6stat.ip6s_badoptions++;
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
			icmp6_error(m, ICMP6_PARAM_PROB,
				    ICMP6_PARAMPROB_HEADER,
				    (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
			return;
		}
#ifndef PULLDOWN_TEST
		/* ip6_hopopts_input() ensures that mbuf is contiguous */
		hbh = (struct ip6_hbh *)(ip6 + 1);
#else
		IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
			sizeof(struct ip6_hbh));
		if (hbh == NULL) {
			ip6stat.ip6s_tooshort++;
			return;
		}
#endif
		nxt = hbh->ip6h_nxt;

		/*
		 * accept the packet if a router alert option is included
		 * and we act as an IPv6 router.
		 */
		if (rtalert != ~0 && ip6_forwarding)
			ours = 1;
	} else
		nxt = ip6->ip6_nxt;

	/*
	 * Check that the amount of data in the buffers
	 * is as at least much as the IPv6 header would have us expect.
	 * Trim mbufs if longer than we expect.
	 * Drop packet if shorter than we expect.
	 */
	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
		ip6stat.ip6s_tooshort++;
		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
		goto bad;
	}
	if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
		if (m->m_len == m->m_pkthdr.len) {
			m->m_len = sizeof(struct ip6_hdr) + plen;
			m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
		} else
			m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
	}

	/*
	 * Forward if desirable.
	 */
	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
		/*
		 * If we are acting as a multicast router, all
		 * incoming multicast packets are passed to the
		 * kernel-level multicast forwarding function.
		 * The packet is returned (relatively) intact; if
		 * ip6_mforward() returns a non-zero value, the packet
		 * must be discarded, else it may be accepted below.
		 */
		if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
			ip6stat.ip6s_cantforward++;
			m_freem(m);
			return;
		}
		if (!ours) {
			m_freem(m);
			return;
		}
	} else if (!ours) {
		ip6_forward(m, 0);
		return;
	}	

	ip6 = mtod(m, struct ip6_hdr *);

	/*
	 * Malicious party may be able to use IPv4 mapped addr to confuse
	 * tcp/udp stack and bypass security checks (act as if it was from
	 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1).  Be cautious.
	 *
	 * For SIIT end node behavior, you may want to disable the check.
	 * However, you will  become vulnerable to attacks using IPv4 mapped
	 * source.
	 */
	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
		ip6stat.ip6s_badscope++;
		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
		goto bad;
	}

	/*
	 * Tell launch routine the next header
	 */
#ifdef IFA_STATS
	if (deliverifp != NULL) {
		struct in6_ifaddr *ia6;
		ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
		if (ia6)
			ia6->ia_ifa.ifa_data.ifad_inbytes += m->m_pkthdr.len;
	}
#endif
	ip6stat.ip6s_delivered++;
	in6_ifstat_inc(deliverifp, ifs6_in_deliver);
	nest = 0;
	while (nxt != IPPROTO_DONE) {
		if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
			ip6stat.ip6s_toomanyhdr++;
			goto bad;
		}

		/*
		 * protection against faulty packet - there should be
		 * more sanity checks in header chain processing.
		 */
		if (m->m_pkthdr.len < off) {
			ip6stat.ip6s_tooshort++;
			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
			goto bad;
		}

		nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
	}
	return;
 bad:
	m_freem(m);
}

/*
 * Hop-by-Hop options header processing. If a valid jumbo payload option is
 * included, the real payload length will be stored in plenp.
 */
static int
ip6_hopopts_input(plenp, rtalertp, mp, offp)
	u_int32_t *plenp;
	u_int32_t *rtalertp;	/* XXX: should be stored more smart way */
	struct mbuf **mp;
	int *offp;
{
	struct mbuf *m = *mp;
	int off = *offp, hbhlen;
	struct ip6_hbh *hbh;
	u_int8_t *opt;

	/* validation of the length of the header */
#ifndef PULLDOWN_TEST
	IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
	hbhlen = (hbh->ip6h_len + 1) << 3;

	IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
#else
	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
		sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
	if (hbh == NULL) {
		ip6stat.ip6s_tooshort++;
		return -1;
	}
	hbhlen = (hbh->ip6h_len + 1) << 3;
	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
		hbhlen);
	if (hbh == NULL) {
		ip6stat.ip6s_tooshort++;
		return -1;
	}
#endif
	off += hbhlen;
	hbhlen -= sizeof(struct ip6_hbh);
	opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);

	if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
				hbhlen, rtalertp, plenp) < 0)
		return(-1);

	*offp = off;
	*mp = m;
	return(0);
}

/*
 * Search header for all Hop-by-hop options and process each option.
 * This function is separate from ip6_hopopts_input() in order to
 * handle a case where the sending node itself process its hop-by-hop
 * options header. In such a case, the function is called from ip6_output().
 */
int
ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp)
	struct mbuf *m;
	u_int8_t *opthead;
	int hbhlen;
	u_int32_t *rtalertp;
	u_int32_t *plenp;
{
	struct ip6_hdr *ip6;
	int optlen = 0;
	u_int8_t *opt = opthead;
	u_int16_t rtalert_val;
	u_int32_t jumboplen;

	for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
		switch (*opt) {
		case IP6OPT_PAD1:
			optlen = 1;
			break;
		case IP6OPT_PADN:
			if (hbhlen < IP6OPT_MINLEN) {
				ip6stat.ip6s_toosmall++;
				goto bad;
			}
			optlen = *(opt + 1) + 2;
			break;
		case IP6OPT_RTALERT:
			/* XXX may need check for alignment */
			if (hbhlen < IP6OPT_RTALERT_LEN) {
				ip6stat.ip6s_toosmall++;
				goto bad;
			}
			if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
				 /* XXX: should we discard the packet? */
				log(LOG_ERR, "length of router alert opt is inconsitent(%d)",
				    *(opt + 1));
			}
			optlen = IP6OPT_RTALERT_LEN;
			bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
			*rtalertp = ntohs(rtalert_val);
			break;
		case IP6OPT_JUMBO:
			/* XXX may need check for alignment */
			if (hbhlen < IP6OPT_JUMBO_LEN) {
				ip6stat.ip6s_toosmall++;
				goto bad;
			}
			if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
				/* XXX: should we discard the packet? */
				log(LOG_ERR, "length of jumbopayload opt "
				    "is inconsistent(%d)\n",
				    *(opt + 1));
			}
			optlen = IP6OPT_JUMBO_LEN;

			/*
			 * IPv6 packets that have non 0 payload length
			 * must not contain a jumbo payload option.
			 */
			ip6 = mtod(m, struct ip6_hdr *);
			if (ip6->ip6_plen) {
				ip6stat.ip6s_badoptions++;
				icmp6_error(m, ICMP6_PARAM_PROB,
					    ICMP6_PARAMPROB_HEADER,
					    sizeof(struct ip6_hdr) +
					    sizeof(struct ip6_hbh) +
					    opt - opthead);
				return(-1);
			}

			/*
			 * We may see jumbolen in unaligned location, so
			 * we'd need to perform bcopy().
			 */
			bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
			jumboplen = (u_int32_t)htonl(jumboplen);

#if 1
			/*
			 * if there are multiple jumbo payload options,
			 * *plenp will be non-zero and the packet will be
			 * rejected.
			 * the behavior may need some debate in ipngwg -
			 * multiple options does not make sense, however,
			 * there's no explicit mention in specification.
			 */
			if (*plenp != 0) {
				ip6stat.ip6s_badoptions++;
				icmp6_error(m, ICMP6_PARAM_PROB,
					    ICMP6_PARAMPROB_HEADER,
					    sizeof(struct ip6_hdr) +
					    sizeof(struct ip6_hbh) +
					    opt + 2 - opthead);
				return(-1);
			}
#endif

			/*
			 * jumbo payload length must be larger than 65535.
			 */
			if (jumboplen <= IPV6_MAXPACKET) {
				ip6stat.ip6s_badoptions++;
				icmp6_error(m, ICMP6_PARAM_PROB,
					    ICMP6_PARAMPROB_HEADER,
					    sizeof(struct ip6_hdr) +
					    sizeof(struct ip6_hbh) +
					    opt + 2 - opthead);
				return(-1);
			}
			*plenp = jumboplen;

			break;
		default:		/* unknown option */
			if (hbhlen < IP6OPT_MINLEN) {
				ip6stat.ip6s_toosmall++;
				goto bad;
			}
			if ((optlen = ip6_unknown_opt(opt, m,
						      sizeof(struct ip6_hdr) +
						      sizeof(struct ip6_hbh) +
						      opt - opthead)) == -1)
				return(-1);
			optlen += 2;
			break;
		}
	}

	return(0);

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

/*
 * Unknown option processing.
 * The third argument `off' is the offset from the IPv6 header to the option,
 * which is necessary if the IPv6 header the and option header and IPv6 header
 * is not continuous in order to return an ICMPv6 error.
 */
int
ip6_unknown_opt(optp, m, off)
	u_int8_t *optp;
	struct mbuf *m;
	int off;
{
	struct ip6_hdr *ip6;

	switch (IP6OPT_TYPE(*optp)) {
	case IP6OPT_TYPE_SKIP: /* ignore the option */
		return((int)*(optp + 1));
	case IP6OPT_TYPE_DISCARD:	/* silently discard */
		m_freem(m);
		return(-1);
	case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
		ip6stat.ip6s_badoptions++;
		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
		return(-1);
	case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
		ip6stat.ip6s_badoptions++;
		ip6 = mtod(m, struct ip6_hdr *);
		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
		    (m->m_flags & (M_BCAST|M_MCAST)))
			m_freem(m);
		else
			icmp6_error(m, ICMP6_PARAM_PROB,
				    ICMP6_PARAMPROB_OPTION, off);
		return(-1);
	}

	m_freem(m);		/* XXX: NOTREACHED */
	return(-1);
}

/*
 * Create the "control" list for this pcb.
 *
 * The routine will be called from upper layer handlers like tcp6_input().
 * Thus the routine assumes that the caller (tcp6_input) have already
 * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
 * very first mbuf on the mbuf chain.
 * We may want to add some infinite loop prevention or sanity checks for safety.
 * (This applies only when you are using KAME mbuf chain restriction, i.e.
 * you are using IP6_EXTHDR_CHECK() not m_pulldown())
 */
void
ip6_savecontrol(in6p, mp, ip6, m)
	struct in6pcb *in6p;
	struct mbuf **mp;
	struct ip6_hdr *ip6;
	struct mbuf *m;
{
	struct proc *p = curproc;	/* XXX */
	int privileged;

	privileged = 0;
	if (p && !suser(p->p_ucred, &p->p_acflag))
		privileged++;

#ifdef SO_TIMESTAMP
	if (in6p->in6p_socket->so_options & SO_TIMESTAMP) {
		struct timeval tv;

		microtime(&tv);
		*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
			SCM_TIMESTAMP, SOL_SOCKET);
		if (*mp)
			mp = &(*mp)->m_next;
	}
#endif
	if (in6p->in6p_flags & IN6P_RECVDSTADDR) {
		*mp = sbcreatecontrol((caddr_t) &ip6->ip6_dst,
			sizeof(struct in6_addr), IPV6_RECVDSTADDR,
			IPPROTO_IPV6);
		if (*mp)
			mp = &(*mp)->m_next;
	}

#ifdef noyet
	/* options were tossed above */
	if (in6p->in6p_flags & IN6P_RECVOPTS)
		/* broken */
	/* ip6_srcroute doesn't do what we want here, need to fix */
	if (in6p->in6p_flags & IPV6P_RECVRETOPTS)
		/* broken */
#endif

	/* RFC 2292 sec. 5 */
	if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
		struct in6_pktinfo pi6;
		bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
		if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr))
			pi6.ipi6_addr.s6_addr16[1] = 0;
		pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif)
					? m->m_pkthdr.rcvif->if_index
					: 0;
		*mp = sbcreatecontrol((caddr_t) &pi6,
			sizeof(struct in6_pktinfo), IPV6_PKTINFO,
			IPPROTO_IPV6);
		if (*mp)
			mp = &(*mp)->m_next;
	}
	if (in6p->in6p_flags & IN6P_HOPLIMIT) {
		int hlim = ip6->ip6_hlim & 0xff;
		*mp = sbcreatecontrol((caddr_t) &hlim,
			sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6);
		if (*mp)
			mp = &(*mp)->m_next;
	}
	/* IN6P_NEXTHOP - for outgoing packet only */

	/*
	 * IPV6_HOPOPTS socket option. We require super-user privilege
	 * for the option, but it might be too strict, since there might
	 * be some hop-by-hop options which can be returned to normal user.
	 * See RFC 2292 section 6.
	 */
	if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) {
		/*
		 * Check if a hop-by-hop options header is contatined in the
		 * received packet, and if so, store the options as ancillary
		 * data. Note that a hop-by-hop options header must be
		 * just after the IPv6 header, which fact is assured through
		 * the IPv6 input processing.
		 */
		struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
		if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
			struct ip6_hbh *hbh;
			int hbhlen;

#ifndef PULLDOWN_TEST
			hbh = (struct ip6_hbh *)(ip6 + 1);
			hbhlen = (hbh->ip6h_len + 1) << 3;
#else
			IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
				sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
			if (hbh == NULL) {
				ip6stat.ip6s_tooshort++;
				return;
			}
			hbhlen = (hbh->ip6h_len + 1) << 3;
			IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
				sizeof(struct ip6_hdr), hbhlen);
			if (hbh == NULL) {
				ip6stat.ip6s_tooshort++;
				return;
			}
#endif

			/*
			 * XXX: We copy whole the header even if a jumbo
			 * payload option is included, which option is to
			 * be removed before returning in the RFC 2292.
			 * But it's too painful operation...
			 */
			*mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
					      IPV6_HOPOPTS, IPPROTO_IPV6);
			if (*mp)
				mp = &(*mp)->m_next;
		}
	}

	/* IPV6_DSTOPTS and IPV6_RTHDR socket options */
	if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) {
		struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
		int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);;

		/*
		 * Search for destination options headers or routing
		 * header(s) through the header chain, and stores each
		 * header as ancillary data.
		 * Note that the order of the headers remains in
		 * the chain of ancillary data.
		 */
		while (1) {	/* is explicit loop prevention necessary? */
			struct ip6_ext *ip6e;
			int elen;

#ifndef PULLDOWN_TEST
			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
			if (nxt == IPPROTO_AH)
				elen = (ip6e->ip6e_len + 2) << 2;
			else
				elen = (ip6e->ip6e_len + 1) << 3;
#else
			IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off,
				sizeof(struct ip6_ext));
			if (ip6e == NULL) {
				ip6stat.ip6s_tooshort++;
				return;
			}
			if (nxt == IPPROTO_AH)
				elen = (ip6e->ip6e_len + 2) << 2;
			else
				elen = (ip6e->ip6e_len + 1) << 3;
			IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off, elen);
			if (ip6e == NULL) {
				ip6stat.ip6s_tooshort++;
				return;
			}
#endif

			switch (nxt) {
		        case IPPROTO_DSTOPTS:
				if (!in6p->in6p_flags & IN6P_DSTOPTS)
					break;

				/*
				 * We also require super-user privilege for
				 * the option.
				 * See the comments on IN6_HOPOPTS.
				 */
				if (!privileged)
					break;

				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
						      IPV6_DSTOPTS,
						      IPPROTO_IPV6);
				if (*mp)
					mp = &(*mp)->m_next;
				break;

			case IPPROTO_ROUTING:
				if (!in6p->in6p_flags & IN6P_RTHDR)
					break;

				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
						      IPV6_RTHDR,
						      IPPROTO_IPV6);
				if (*mp)
					mp = &(*mp)->m_next;
				break;

			case IPPROTO_UDP:
			case IPPROTO_TCP:
			case IPPROTO_ICMPV6:
			default:
				/*
				 * stop search if we encounter an upper
				 * layer protocol headers.
				 */
				goto loopend;

			case IPPROTO_HOPOPTS:
			case IPPROTO_AH: /* is it possible? */
				break;
			}

			/* proceed with the next header. */
			off += elen;
			nxt = ip6e->ip6e_nxt;
		}
	  loopend:
	}
	if ((in6p->in6p_flags & IN6P_HOPOPTS) && privileged) {
		/* to be done */
	}
	if ((in6p->in6p_flags & IN6P_DSTOPTS) && privileged) {
		/* to be done */
	}
	/* IN6P_RTHDR - to be done */

}

/*
 * Get pointer to the previous header followed by the header
 * currently processed.
 * XXX: This function supposes that
 *	M includes all headers,
 *	the next header field and the header length field of each header
 *	are valid, and
 *	the sum of each header length equals to OFF.
 * Because of these assumptions, this function must be called very
 * carefully. Moreover, it will not be used in the near future when
 * we develop `neater' mechanism to process extension headers.
 */
char *
ip6_get_prevhdr(m, off)
	struct mbuf *m;
	int off;
{
	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);

	if (off == sizeof(struct ip6_hdr))
		return(&ip6->ip6_nxt);
	else {
		int len, nxt;
		struct ip6_ext *ip6e = NULL;

		nxt = ip6->ip6_nxt;
		len = sizeof(struct ip6_hdr);
		while (len < off) {
			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);

			switch (nxt) {
			case IPPROTO_FRAGMENT:
				len += sizeof(struct ip6_frag);
				break;
			case IPPROTO_AH:
				len += (ip6e->ip6e_len + 2) << 2;
				break;
			default:
				len += (ip6e->ip6e_len + 1) << 3;
				break;
			}
			nxt = ip6e->ip6e_nxt;
		}
		if (ip6e)
			return(&ip6e->ip6e_nxt);
		else
			return NULL;
	}
}

/*
 * get next header offset.  m will be retained.
 */
int
ip6_nexthdr(m, off, proto, nxtp)
	struct mbuf *m;
	int off;
	int proto;
	int *nxtp;
{
	struct ip6_hdr ip6;
	struct ip6_ext ip6e;
	struct ip6_frag fh;

	/* just in case */
	if (m == NULL)
		panic("ip6_nexthdr: m == NULL");
	if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
		return -1;

	switch (proto) {
	case IPPROTO_IPV6:
		if (m->m_pkthdr.len < off + sizeof(ip6))
			return -1;
		m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
		if (nxtp)
			*nxtp = ip6.ip6_nxt;
		off += sizeof(ip6);
		return off;

	case IPPROTO_FRAGMENT:
		/*
		 * terminate parsing if it is not the first fragment,
		 * it does not make sense to parse through it.
		 */
		if (m->m_pkthdr.len < off + sizeof(fh))
			return -1;
		m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
		if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0)
			return -1;
		if (nxtp)
			*nxtp = fh.ip6f_nxt;
		off += sizeof(struct ip6_frag);
		return off;

	case IPPROTO_AH:
		if (m->m_pkthdr.len < off + sizeof(ip6e))
			return -1;
		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
		if (nxtp)
			*nxtp = ip6e.ip6e_nxt;
		off += (ip6e.ip6e_len + 2) << 2;
		return off;

	case IPPROTO_HOPOPTS:
	case IPPROTO_ROUTING:
	case IPPROTO_DSTOPTS:
		if (m->m_pkthdr.len < off + sizeof(ip6e))
			return -1;
		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
		if (nxtp)
			*nxtp = ip6e.ip6e_nxt;
		off += (ip6e.ip6e_len + 1) << 3;
		return off;

	case IPPROTO_NONE:
	case IPPROTO_ESP:
	case IPPROTO_IPCOMP:
		/* give up */
		return -1;

	default:
		return -1;
	}

	return -1;
}

/*
 * get offset for the last header in the chain.  m will be kept untainted.
 */
int
ip6_lasthdr(m, off, proto, nxtp)
	struct mbuf *m;
	int off;
	int proto;
	int *nxtp;
{
	int newoff;
	int nxt;

	if (!nxtp) {
		nxt = -1;
		nxtp = &nxt;
	}
	while (1) {
		newoff = ip6_nexthdr(m, off, proto, nxtp);
		if (newoff < 0)
			return off;
		else if (newoff < off)
			return -1;	/* invalid */
		else if (newoff == off)
			return newoff;

		off = newoff;
		proto = *nxtp;
	}
}

/*
 * System control for IP6
 */

u_char	inet6ctlerrmap[PRC_NCMDS] = {
	0,		0,		0,		0,
	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
	EMSGSIZE,	EHOSTUNREACH,	0,		0,
	0,		0,		0,		0,
	ENOPROTOOPT
};

#include <uvm/uvm_extern.h>
#include <sys/sysctl.h>

int
ip6_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
	int *name;
	u_int namelen;
	void *oldp;
	size_t *oldlenp;
	void *newp;
	size_t newlen;
{
	int old, error;

	/* All sysctl names at this level are terminal. */
	if (namelen != 1)
		return ENOTDIR;

	switch (name[0]) {

	case IPV6CTL_FORWARDING:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				  &ip6_forwarding);
	case IPV6CTL_SENDREDIRECTS:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_sendredirects);
	case IPV6CTL_DEFHLIM:
		return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_defhlim);
	case IPV6CTL_MAXFRAGPACKETS:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_maxfragpackets);
	case IPV6CTL_ACCEPT_RTADV:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_accept_rtadv);
	case IPV6CTL_KEEPFAITH:
		return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_keepfaith);
	case IPV6CTL_LOG_INTERVAL:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_log_interval);
	case IPV6CTL_HDRNESTLIMIT:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_hdrnestlimit);
	case IPV6CTL_DAD_COUNT:
		return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_dad_count);
	case IPV6CTL_AUTO_FLOWLABEL:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_auto_flowlabel);
	case IPV6CTL_DEFMCASTHLIM:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_defmcasthlim);
	case IPV6CTL_GIF_HLIM:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_gif_hlim);
	case IPV6CTL_KAME_VERSION:
		return sysctl_rdstring(oldp, oldlenp, newp, __KAME_VERSION);
	case IPV6CTL_USE_DEPRECATED:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_use_deprecated);
	case IPV6CTL_RR_PRUNE:
		return sysctl_int(oldp, oldlenp, newp, newlen, &ip6_rr_prune);
#ifndef INET6_BINDV6ONLY
	case IPV6CTL_BINDV6ONLY:
		return sysctl_int(oldp, oldlenp, newp, newlen,
				&ip6_bindv6only);
#endif
	case IPV6CTL_ANONPORTMIN:
		old = ip6_anonportmin;
		error = sysctl_int(oldp, oldlenp, newp, newlen,
		    &ip6_anonportmin);
		if (ip6_anonportmin >= ip6_anonportmax || ip6_anonportmin < 0 ||
		    ip6_anonportmin > 65535
#ifndef IPNOPRIVPORTS
		    || ip6_anonportmin < IPV6PORT_RESERVED
#endif
		    ) {
			ip6_anonportmin = old;
			return (EINVAL);
		}
		return (error);
	case IPV6CTL_ANONPORTMAX:
		old = ip6_anonportmax;
		error = sysctl_int(oldp, oldlenp, newp, newlen,
		    &ip6_anonportmax);
		if (ip6_anonportmin >= ip6_anonportmax || ip6_anonportmax < 0 ||
		    ip6_anonportmax > 65535
#ifndef IPNOPRIVPORTS
		    || ip6_anonportmax < IPV6PORT_RESERVED
#endif
		    ) {
			ip6_anonportmax = old;
			return (EINVAL);
		}
		return (error);
#ifndef IPNOPRIVPORTS
	case IPV6CTL_LOWPORTMIN:
		old = ip6_lowportmin;
		error = sysctl_int(oldp, oldlenp, newp, newlen,
		    &ip6_lowportmin);
		if (ip6_lowportmin >= ip6_lowportmax ||
		    ip6_lowportmin > IPV6PORT_RESERVEDMAX ||
		    ip6_lowportmin < IPV6PORT_RESERVEDMIN) {
			ip6_lowportmin = old;
			return (EINVAL);
		}
		return (error);
	case IPV6CTL_LOWPORTMAX:
		old = ip6_lowportmax;
		error = sysctl_int(oldp, oldlenp, newp, newlen,
		    &ip6_lowportmax);
		if (ip6_lowportmin >= ip6_lowportmax ||
		    ip6_lowportmax > IPV6PORT_RESERVEDMAX ||
		    ip6_lowportmax < IPV6PORT_RESERVEDMIN) {
			ip6_lowportmax = old;
			return (EINVAL);
		}
		return (error);
#endif
	default:
		return EOPNOTSUPP;
	}
	/* NOTREACHED */
}