Expand PMF_FN_* macros.

[netbsd-mini2440.git] / sys / netinet6 / ip6_input.c

/*      $NetBSD: ip6_input.c,v 1.127 2009/05/01 03:23:39 martin Exp $   */
/*      $KAME: ip6_input.c,v 1.188 2001/03/29 05:34:31 itojun 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. 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ip6_input.c,v 1.127 2009/05/01 03:23:39 martin Exp $");

#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_pfil_hooks.h"
#include "opt_compat_netbsd.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 <sys/sysctl.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/ip6_private.h>
#include <netinet6/in6_pcb.h>
#include <netinet/icmp6.h>
#include <netinet6/scope6_var.h>
#include <netinet6/in6_ifattach.h>
#include <netinet6/nd6.h>

#ifdef IPSEC
#include <netinet6/ipsec.h>
#include <netinet6/ipsec_private.h>
#endif

#ifdef FAST_IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#include <netipsec/key.h>
#endif /* FAST_IPSEC */

#ifdef COMPAT_50
#include <compat/sys/time.h>
#include <compat/sys/socket.h>
#endif

#include <netinet6/ip6protosw.h>

#include "faith.h"
#include "gif.h"

#if NGIF > 0
#include <netinet6/in6_gif.h>
#endif

#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 callout_t in6_tmpaddrtimer_ch;

int ip6_forward_srcrt;                  /* XXX */
int ip6_sourcecheck;                    /* XXX */
int ip6_sourcecheck_interval;           /* XXX */

#ifdef PFIL_HOOKS
struct pfil_head inet6_pfil_hook;
#endif

percpu_t *ip6stat_percpu;

static void ip6_init2(void *);
static struct m_tag *ip6_setdstifaddr(struct mbuf *, const struct in6_ifaddr *);

static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
static void sysctl_net_inet6_ip6_setup(struct sysctllog **);

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

        sysctl_net_inet6_ip6_setup(NULL);
        pr = (const 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 = (const struct ip6protosw *)inet6domain.dom_protosw;
            pr < (const 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;
        scope6_init();
        addrsel_policy_init();
        nd6_init();
        frag6_init();
        ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;

        ip6_init2((void *)0);
#ifdef GATEWAY
        ip6flow_init(ip6_hashsize);
#endif

#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 */

        ip6stat_percpu = percpu_alloc(sizeof(uint64_t) * IP6_NSTATS);
}

static void
ip6_init2(void *dummy)
{

        /* nd6_timer_init */
        callout_init(&nd6_timer_ch, CALLOUT_MPSAFE);
        callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL);

        /* timer for regeneranation of temporary addresses randomize ID */
        callout_init(&in6_tmpaddrtimer_ch, CALLOUT_MPSAFE);
        callout_reset(&in6_tmpaddrtimer_ch,
                      (ip6_temp_preferred_lifetime - ip6_desync_factor -
                       ip6_temp_regen_advance) * hz,
                      in6_tmpaddrtimer, NULL);
}

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

        mutex_enter(softnet_lock);
        KERNEL_LOCK(1, NULL);
        for (;;) {
                s = splnet();
                IF_DEQUEUE(&ip6intrq, m);
                splx(s);
                if (m == 0)
                        break;
                /* drop the packet if IPv6 operation is disabled on the IF */
                if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
                        m_freem(m);
                        break;
                }
                ip6_input(m);
        }
        KERNEL_UNLOCK_ONE(NULL);
        mutex_exit(softnet_lock);
}

extern struct   route ip6_forward_rt;

void
ip6_input(struct mbuf *m)
{
        struct ip6_hdr *ip6;
        int hit, off = sizeof(struct ip6_hdr), nest;
        u_int32_t plen;
        u_int32_t rtalert = ~0;
        int nxt, ours = 0, rh_present = 0;
        struct ifnet *deliverifp = NULL;
        int srcrt = 0;
        const struct rtentry *rt;
        union {
                struct sockaddr         dst;
                struct sockaddr_in6     dst6;
        } u;
#ifdef FAST_IPSEC
        struct m_tag *mtag;
        struct tdb_ident *tdbi;
        struct secpolicy *sp;
        int s, error;
#endif

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

        /*
         * make sure we don't have onion peering information into m_tag.
         */
        ip6_delaux(m);

        /*
         * mbuf statistics
         */
        if (m->m_flags & M_EXT) {
                if (m->m_next)
                        IP6_STATINC(IP6_STAT_MEXT2M);
                else
                        IP6_STATINC(IP6_STAT_MEXT1);
        } else {
#define M2MMAX  32
                if (m->m_next) {
                        if (m->m_flags & M_LOOP) {
                        /*XXX*/ IP6_STATINC(IP6_STAT_M2M + lo0ifp->if_index);
                        } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) {
                                IP6_STATINC(IP6_STAT_M2M +
                                            m->m_pkthdr.rcvif->if_index);
                        } else
                                IP6_STATINC(IP6_STAT_M2M);
                } else
                        IP6_STATINC(IP6_STAT_M1);
#undef M2MMAX
        }

        in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
        IP6_STATINC(IP6_STAT_TOTAL);

        /*
         * If the IPv6 header is not aligned, slurp it up into a new
         * mbuf with space for link headers, in the event we forward
         * it.  Otherwise, if it is aligned, make sure the entire base
         * IPv6 header is in the first mbuf of the chain.
         */
        if (IP6_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
                struct ifnet *inifp = m->m_pkthdr.rcvif;
                if ((m = m_copyup(m, sizeof(struct ip6_hdr),
                                  (max_linkhdr + 3) & ~3)) == NULL) {
                        /* XXXJRT new stat, please */
                        IP6_STATINC(IP6_STAT_TOOSMALL);
                        in6_ifstat_inc(inifp, ifs6_in_hdrerr);
                        return;
                }
        } else if (__predict_false(m->m_len < sizeof(struct ip6_hdr))) {
                struct ifnet *inifp = m->m_pkthdr.rcvif;
                if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
                        IP6_STATINC(IP6_STAT_TOOSMALL);
                        in6_ifstat_inc(inifp, ifs6_in_hdrerr);
                        return;
                }
        }

        ip6 = mtod(m, struct ip6_hdr *);

        if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
                IP6_STATINC(IP6_STAT_BADVERS);
                in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
                goto bad;
        }

#if defined(IPSEC)
        /* IPv6 fast forwarding is not compatible with IPsec. */
        m->m_flags &= ~M_CANFASTFWD;
#else
        /*
         * Assume that we can create a fast-forward IP flow entry
         * based on this packet.
         */
        m->m_flags |= M_CANFASTFWD;
#endif

#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.
         */
        /*
         * let ipfilter look at packet on the wire,
         * not the decapsulated packet.
         */
#ifdef IPSEC
        if (!ipsec_getnhist(m))
#elif defined(FAST_IPSEC)
        if (!ipsec_indone(m))
#else
        if (1)
#endif
        {
                struct in6_addr odst;

                odst = ip6->ip6_dst;
                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 *);
                srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
        }
#endif /* PFIL_HOOKS */

        IP6_STATINC(IP6_STAT_NXTHIST + ip6->ip6_nxt);

#ifdef ALTQ
        if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
                /* packet is dropped by traffic conditioner */
                return;
        }
#endif

        /*
         * Check against address spoofing/corruption.
         */
        if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
            IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
                /*
                 * XXX: "badscope" is not very suitable for a multicast source.
                 */
                IP6_STATINC(IP6_STAT_BADSCOPE);
                in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
                goto bad;
        }
        /*
         * The following check is not documented in specs.  A 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 an 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
         * partial support for SIIT environment.
         */
        if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
            IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
                IP6_STATINC(IP6_STAT_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)) {
                IP6_STATINC(IP6_STAT_BADSCOPE);
                in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
                goto bad;
        }
#endif

        /*
         * Disambiguate address scope zones (if there is ambiguity).
         * We first make sure that the original source or destination address
         * is not in our internal form for scoped addresses.  Such addresses
         * are not necessarily invalid spec-wise, but we cannot accept them due
         * to the usage conflict.
         * in6_setscope() then also checks and rejects the cases where src or
         * dst are the loopback address and the receiving interface
         * is not loopback. 
         */
        if (__predict_false(
            m_makewritable(&m, 0, sizeof(struct ip6_hdr), M_DONTWAIT)))
                goto bad;
        ip6 = mtod(m, struct ip6_hdr *);
        if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
                IP6_STATINC(IP6_STAT_BADSCOPE); /* XXX */
                goto bad;
        }
        if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
            in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
                IP6_STATINC(IP6_STAT_BADSCOPE);
                goto bad;
        }

        /*
         * 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) {
                        uint64_t *ip6s = IP6_STAT_GETREF();
                        ip6s[IP6_STAT_NOTMEMBER]++;
                        ip6s[IP6_STAT_CANTFORWARD]++;
                        IP6_STAT_PUTREF();
                        in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
                        goto bad;
                }
                deliverifp = m->m_pkthdr.rcvif;
                goto hbhcheck;
        }

        sockaddr_in6_init(&u.dst6, &ip6->ip6_dst, 0, 0, 0);

        /*
         *  Unicast check
         */
        rt = rtcache_lookup2(&ip6_forward_rt, &u.dst, 1, &hit);
        if (hit)
                IP6_STATINC(IP6_STAT_FORWARD_CACHEHIT);
        else
                IP6_STATINC(IP6_STAT_FORWARD_CACHEMISS);

#define rt6_getkey(__rt) satocsin6(rt_getkey(__rt))

        /*
         * 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 (rt != NULL &&
            (rt->rt_flags & (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
            !(rt->rt_flags & RTF_CLONED) &&
#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_getkey(rt)->sin6_addr) &&
#endif
            rt->rt_ifp->if_type == IFT_LOOP) {
                struct in6_ifaddr *ia6 = (struct in6_ifaddr *)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 (rt != NULL && rt->rt_ifp != NULL &&
                    rt->rt_ifp->if_type == IFT_FAITH) {
                        /* XXX do we need more sanity checks? */
                        ours = 1;
                        deliverifp = 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;
        IFADDR_FOREACH(ifa, m->m_pkthdr.rcvif) {
                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) {
                IP6_STATINC(IP6_STAT_CANTFORWARD);
                in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
                goto bad;
        }

  hbhcheck:
        /*
         * record address information into m_tag, if we don't have one yet.
         * note that we are unable to record it, if the address is not listed
         * as our interface address (e.g. multicast addresses, addresses
         * within FAITH prefixes and such).
         */
        if (deliverifp && ip6_getdstifaddr(m) == NULL) {
                struct in6_ifaddr *ia6;

                ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
                if (ia6 != NULL && ip6_setdstifaddr(m, ia6) == NULL) {
                        /*
                         * XXX maybe we should drop the packet here,
                         * as we could not provide enough information
                         * to the upper layers.
                         */
                }
        }

        /*
         * 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_hopopts_input() must set a valid
                         * (non-zero) payload length to the variable plen.
                         */
                        IP6_STATINC(IP6_STAT_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,
                                    (char *)&ip6->ip6_plen - (char *)ip6);
                        return;
                }
                IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
                        sizeof(struct ip6_hbh));
                if (hbh == NULL) {
                        IP6_STATINC(IP6_STAT_TOOSHORT);
                        return;
                }
                KASSERT(IP6_HDR_ALIGNED_P(hbh));
                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) {
                IP6_STATINC(IP6_STAT_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)) {
                        IP6_STATINC(IP6_STAT_CANTFORWARD);
                        m_freem(m);
                        return;
                }
                if (!ours) {
                        m_freem(m);
                        return;
                }
        } else if (!ours) {
                ip6_forward(m, srcrt);
                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)) {
                IP6_STATINC(IP6_STAT_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
        IP6_STATINC(IP6_STAT_DELIVERED);
        in6_ifstat_inc(deliverifp, ifs6_in_deliver);
        nest = 0;

        rh_present = 0;
        while (nxt != IPPROTO_DONE) {
                if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) {
                        IP6_STATINC(IP6_STAT_TOOMANYHDR);
                        in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
                        goto bad;
                }

                /*
                 * protection against faulty packet - there should be
                 * more sanity checks in header chain processing.
                 */
                if (m->m_pkthdr.len < off) {
                        IP6_STATINC(IP6_STAT_TOOSHORT);
                        in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
                        goto bad;
                }

                if (nxt == IPPROTO_ROUTING) {
                        if (rh_present++) {
                                in6_ifstat_inc(m->m_pkthdr.rcvif,
                                    ifs6_in_hdrerr);
                                IP6_STATINC(IP6_STAT_BADOPTIONS);
                                goto bad;
                        }
                }

#ifdef IPSEC
                /*
                 * enforce IPsec policy checking if we are seeing last header.
                 * note that we do not visit this with protocols with pcb layer
                 * code - like udp/tcp/raw ip.
                 */
                if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
                    ipsec6_in_reject(m, NULL)) {
                        IPSEC6_STATINC(IPSEC_STAT_IN_POLVIO);
                        goto bad;
                }
#endif
#ifdef FAST_IPSEC
        /*
         * enforce IPsec policy checking if we are seeing last header.
         * note that we do not visit this with protocols with pcb layer
         * code - like udp/tcp/raw ip.
         */
        if ((inet6sw[ip_protox[nxt]].pr_flags & PR_LASTHDR) != 0) {
                /*
                 * Check if the packet has already had IPsec processing
                 * done.  If so, then just pass it along.  This tag gets
                 * set during AH, ESP, etc. input handling, before the
                 * packet is returned to the ip input queue for delivery.
                 */
                mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
                s = splsoftnet();
                if (mtag != NULL) {
                        tdbi = (struct tdb_ident *)(mtag + 1);
                        sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
                } else {
                        sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
                                                                        IP_FORWARDING, &error);
                }
                if (sp != NULL) {
                        /*
                         * Check security policy against packet attributes.
                         */
                        error = ipsec_in_reject(sp, m);
                        KEY_FREESP(&sp);
                } else {
                        /* XXX error stat??? */
                        error = EINVAL;
                        DPRINTF(("ip6_input: no SP, packet discarded\n"));/*XXX*/
                }
                splx(s);
                if (error)
                        goto bad;
        }
#endif /* FAST_IPSEC */


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

/*
 * set/grab in6_ifaddr correspond to IPv6 destination address.
 */
static struct m_tag *
ip6_setdstifaddr(struct mbuf *m, const struct in6_ifaddr *ia)
{
        struct m_tag *mtag;

        mtag = ip6_addaux(m);
        if (mtag != NULL) {
                struct ip6aux *ip6a;

                ip6a = (struct ip6aux *)(mtag + 1);
                in6_setscope(&ip6a->ip6a_src, ia->ia_ifp, &ip6a->ip6a_scope_id);
                ip6a->ip6a_src = ia->ia_addr.sin6_addr;
                ip6a->ip6a_flags = ia->ia6_flags;
        }
        return mtag;    /* NULL if failed to set */
}

const struct ip6aux *
ip6_getdstifaddr(struct mbuf *m)
{
        struct m_tag *mtag;

        mtag = ip6_findaux(m);
        if (mtag != NULL)
                return (struct ip6aux *)(mtag + 1);
        else
                return NULL;
}

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

        /* validation of the length of the header */
        IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
                sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
        if (hbh == NULL) {
                IP6_STATINC(IP6_STAT_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) {
                IP6_STATINC(IP6_STAT_TOOSHORT);
                return -1;
        }
        KASSERT(IP6_HDR_ALIGNED_P(hbh));
        off += hbhlen;
        hbhlen -= 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().
 *
 * The function assumes that hbh header is located right after the IPv6 header
 * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
 * opthead + hbhlen is located in continuous memory region.
 */
int
ip6_process_hopopts(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;
        const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);

        for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
                switch (*opt) {
                case IP6OPT_PAD1:
                        optlen = 1;
                        break;
                case IP6OPT_PADN:
                        if (hbhlen < IP6OPT_MINLEN) {
                                IP6_STATINC(IP6_STAT_TOOSMALL);
                                goto bad;
                        }
                        optlen = *(opt + 1) + 2;
                        break;
                case IP6OPT_RTALERT:
                        /* XXX may need check for alignment */
                        if (hbhlen < IP6OPT_RTALERT_LEN) {
                                IP6_STATINC(IP6_STAT_TOOSMALL);
                                goto bad;
                        }
                        if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
                                /* XXX stat */
                                icmp6_error(m, ICMP6_PARAM_PROB,
                                    ICMP6_PARAMPROB_HEADER,
                                    erroff + opt + 1 - opthead);
                                return (-1);
                        }
                        optlen = IP6OPT_RTALERT_LEN;
                        memcpy((void *)&rtalert_val, (void *)(opt + 2), 2);
                        *rtalertp = ntohs(rtalert_val);
                        break;
                case IP6OPT_JUMBO:
                        /* XXX may need check for alignment */
                        if (hbhlen < IP6OPT_JUMBO_LEN) {
                                IP6_STATINC(IP6_STAT_TOOSMALL);
                                goto bad;
                        }
                        if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
                                /* XXX stat */
                                icmp6_error(m, ICMP6_PARAM_PROB,
                                    ICMP6_PARAMPROB_HEADER,
                                    erroff + opt + 1 - opthead);
                                return (-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) {
                                IP6_STATINC(IP6_STAT_BADOPTIONS);
                                icmp6_error(m, ICMP6_PARAM_PROB,
                                    ICMP6_PARAMPROB_HEADER,
                                    erroff + opt - opthead);
                                return (-1);
                        }

                        /*
                         * We may see jumbolen in unaligned location, so
                         * we'd need to perform bcopy().
                         */
                        memcpy(&jumboplen, opt + 2, 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) {
                                IP6_STATINC(IP6_STAT_BADOPTIONS);
                                icmp6_error(m, ICMP6_PARAM_PROB,
                                    ICMP6_PARAMPROB_HEADER,
                                    erroff + opt + 2 - opthead);
                                return (-1);
                        }
#endif

                        /*
                         * jumbo payload length must be larger than 65535.
                         */
                        if (jumboplen <= IPV6_MAXPACKET) {
                                IP6_STATINC(IP6_STAT_BADOPTIONS);
                                icmp6_error(m, ICMP6_PARAM_PROB,
                                    ICMP6_PARAMPROB_HEADER,
                                    erroff + opt + 2 - opthead);
                                return (-1);
                        }
                        *plenp = jumboplen;

                        break;
                default:                /* unknown option */
                        if (hbhlen < IP6OPT_MINLEN) {
                                IP6_STATINC(IP6_STAT_TOOSMALL);
                                goto bad;
                        }
                        optlen = ip6_unknown_opt(opt, m,
                            erroff + opt - opthead);
                        if (optlen == -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(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 */
                IP6_STATINC(IP6_STAT_BADOPTIONS);
                icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
                return (-1);
        case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
                IP6_STATINC(IP6_STAT_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(struct in6pcb *in6p, struct mbuf **mp, 
        struct ip6_hdr *ip6, struct mbuf *m)
{
#ifdef RFC2292
#define IS2292(x, y)    ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
#else
#define IS2292(x, y)    (y)
#endif

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

                microtime(&tv);
#ifdef SO_OTIMESTAMP
                if (in6p->in6p_socket->so_options & SO_OTIMESTAMP) {
                        struct timeval50 tv50;
                        timeval_to_timeval50(&tv, &tv50);
                        *mp = sbcreatecontrol((void *) &tv50, sizeof(tv50),
                            SCM_OTIMESTAMP, SOL_SOCKET);
                } else
#endif
                *mp = sbcreatecontrol((void *) &tv, sizeof(tv),
                    SCM_TIMESTAMP, SOL_SOCKET);
                if (*mp)
                        mp = &(*mp)->m_next;
        }

        /* some OSes call this logic with IPv4 packet, for SO_TIMESTAMP */
        if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
                return;

        /* RFC 2292 sec. 5 */
        if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) {
                struct in6_pktinfo pi6;

                memcpy(&pi6.ipi6_addr, &ip6->ip6_dst, sizeof(struct in6_addr));
                in6_clearscope(&pi6.ipi6_addr); /* XXX */
                pi6.ipi6_ifindex = m->m_pkthdr.rcvif ?
                    m->m_pkthdr.rcvif->if_index : 0;
                *mp = sbcreatecontrol((void *) &pi6,
                    sizeof(struct in6_pktinfo),
                    IS2292(IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
                if (*mp)
                        mp = &(*mp)->m_next;
        }

        if (in6p->in6p_flags & IN6P_HOPLIMIT) {
                int hlim = ip6->ip6_hlim & 0xff;

                *mp = sbcreatecontrol((void *) &hlim, sizeof(int),
                    IS2292(IPV6_2292HOPLIMIT, IPV6_HOPLIMIT), IPPROTO_IPV6);
                if (*mp)
                        mp = &(*mp)->m_next;
        }

        if ((in6p->in6p_flags & IN6P_TCLASS) != 0) {
                u_int32_t flowinfo;
                int tclass;

                flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
                flowinfo >>= 20;

                tclass = flowinfo & 0xff;
                *mp = sbcreatecontrol((void *)&tclass, sizeof(tclass),
                    IPV6_TCLASS, IPPROTO_IPV6);

                if (*mp)
                        mp = &(*mp)->m_next;
        }

        /*
         * IPV6_HOPOPTS socket option.  Recall that we required super-user
         * privilege for the option (see ip6_ctloutput), but it might be too
         * strict, since there might be some hop-by-hop options which can be
         * returned to normal user.
         * See also RFC3542 section 8 (or RFC2292 section 6).
         */
        if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0) {
                /*
                 * 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 *xip6 = mtod(m, struct ip6_hdr *);
                if (xip6->ip6_nxt == IPPROTO_HOPOPTS) {
                        struct ip6_hbh *hbh;
                        int hbhlen;
                        struct mbuf *ext;

                        ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
                            xip6->ip6_nxt);
                        if (ext == NULL) {
                                IP6_STATINC(IP6_STAT_TOOSHORT);
                                return;
                        }
                        hbh = mtod(ext, struct ip6_hbh *);
                        hbhlen = (hbh->ip6h_len + 1) << 3;
                        if (hbhlen != ext->m_len) {
                                m_freem(ext);
                                IP6_STATINC(IP6_STAT_TOOSHORT);
                                return;
                        }

                        /*
                         * 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.
                         * Note: this constraint is removed in RFC3542.
                         */
                        *mp = sbcreatecontrol((void *)hbh, hbhlen,
                            IS2292(IPV6_2292HOPOPTS, IPV6_HOPOPTS),
                            IPPROTO_IPV6);
                        if (*mp)
                                mp = &(*mp)->m_next;
                        m_freem(ext);
                }
        }

        /* IPV6_DSTOPTS and IPV6_RTHDR socket options */
        if (in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDR)) {
                struct ip6_hdr *xip6 = mtod(m, struct ip6_hdr *);
                int nxt = xip6->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.
                 */
                for (;;) {      /* is explicit loop prevention necessary? */
                        struct ip6_ext *ip6e = NULL;
                        int elen;
                        struct mbuf *ext = NULL;

                        /*
                         * if it is not an extension header, don't try to
                         * pull it from the chain.
                         */
                        switch (nxt) {
                        case IPPROTO_DSTOPTS:
                        case IPPROTO_ROUTING:
                        case IPPROTO_HOPOPTS:
                        case IPPROTO_AH: /* is it possible? */
                                break;
                        default:
                                goto loopend;
                        }

                        ext = ip6_pullexthdr(m, off, nxt);
                        if (ext == NULL) {
                                IP6_STATINC(IP6_STAT_TOOSHORT);
                                return;
                        }
                        ip6e = mtod(ext, struct ip6_ext *);
                        if (nxt == IPPROTO_AH)
                                elen = (ip6e->ip6e_len + 2) << 2;
                        else
                                elen = (ip6e->ip6e_len + 1) << 3;
                        if (elen != ext->m_len) {
                                m_freem(ext);
                                IP6_STATINC(IP6_STAT_TOOSHORT);
                                return;
                        }
                        KASSERT(IP6_HDR_ALIGNED_P(ip6e));

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

                                *mp = sbcreatecontrol((void *)ip6e, elen,
                                    IS2292(IPV6_2292DSTOPTS, IPV6_DSTOPTS),
                                    IPPROTO_IPV6);
                                if (*mp)
                                        mp = &(*mp)->m_next;
                                break;

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

                                *mp = sbcreatecontrol((void *)ip6e, elen,
                                    IS2292(IPV6_2292RTHDR, IPV6_RTHDR),
                                    IPPROTO_IPV6);
                                if (*mp)
                                        mp = &(*mp)->m_next;
                                break;

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

                        default:
                                /*
                                 * other cases have been filtered in the above.
                                 * none will visit this case.  here we supply
                                 * the code just in case (nxt overwritten or
                                 * other cases).
                                 */
                                m_freem(ext);
                                goto loopend;

                        }

                        /* proceed with the next header. */
                        off += elen;
                        nxt = ip6e->ip6e_nxt;
                        ip6e = NULL;
                        m_freem(ext);
                        ext = NULL;
                }
          loopend:
                ;
        }
}
#undef IS2292


void
ip6_notify_pmtu(struct in6pcb *in6p, const struct sockaddr_in6 *dst,
    uint32_t *mtu)
{
        struct socket *so;
        struct mbuf *m_mtu;
        struct ip6_mtuinfo mtuctl;

        so = in6p->in6p_socket;

        if (mtu == NULL)
                return;

#ifdef DIAGNOSTIC
        if (so == NULL)         /* I believe this is impossible */
                panic("ip6_notify_pmtu: socket is NULL");
#endif

        memset(&mtuctl, 0, sizeof(mtuctl));     /* zero-clear for safety */
        mtuctl.ip6m_mtu = *mtu;
        mtuctl.ip6m_addr = *dst;
        if (sa6_recoverscope(&mtuctl.ip6m_addr))
                return;

        if ((m_mtu = sbcreatecontrol((void *)&mtuctl, sizeof(mtuctl),
            IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
                return;

        if (sbappendaddr(&so->so_rcv, (const struct sockaddr *)dst, NULL, m_mtu)
            == 0) {
                m_freem(m_mtu);
                /* XXX: should count statistics */
        } else
                sorwakeup(so);

        return;
}

/*
 * pull single extension header from mbuf chain.  returns single mbuf that
 * contains the result, or NULL on error.
 */
static struct mbuf *
ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
{
        struct ip6_ext ip6e;
        size_t elen;
        struct mbuf *n;

#ifdef DIAGNOSTIC
        switch (nxt) {
        case IPPROTO_DSTOPTS:
        case IPPROTO_ROUTING:
        case IPPROTO_HOPOPTS:
        case IPPROTO_AH: /* is it possible? */
                break;
        default:
                printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
        }
#endif

        m_copydata(m, off, sizeof(ip6e), (void *)&ip6e);
        if (nxt == IPPROTO_AH)
                elen = (ip6e.ip6e_len + 2) << 2;
        else
                elen = (ip6e.ip6e_len + 1) << 3;

        MGET(n, M_DONTWAIT, MT_DATA);
        if (n && elen >= MLEN) {
                MCLGET(n, M_DONTWAIT);
                if ((n->m_flags & M_EXT) == 0) {
                        m_free(n);
                        n = NULL;
                }
        }
        if (!n)
                return NULL;

        n->m_len = 0;
        if (elen >= M_TRAILINGSPACE(n)) {
                m_free(n);
                return NULL;
        }

        m_copydata(m, off, elen, mtod(n, void *));
        n->m_len = elen;
        return n;
}

/*
 * 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.
 */
u_int8_t *
ip6_get_prevhdr(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, char *) + 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(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:
                /* do not chase beyond intermediate IPv6 headers */
                if (off != 0)
                        return -1;
                if (m->m_pkthdr.len < off + sizeof(ip6))
                        return -1;
                m_copydata(m, off, sizeof(ip6), (void *)&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), (void *)&fh);
                if ((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), (void *)&ip6e);
                if (nxtp)
                        *nxtp = ip6e.ip6e_nxt;
                off += (ip6e.ip6e_len + 2) << 2;
                if (m->m_pkthdr.len < off)
                        return -1;
                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), (void *)&ip6e);
                if (nxtp)
                        *nxtp = ip6e.ip6e_nxt;
                off += (ip6e.ip6e_len + 1) << 3;
                if (m->m_pkthdr.len < off)
                        return -1;
                return off;

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

        default:
                return -1;
        }
}

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

        if (!nxtp) {
                nxt = -1;
                nxtp = &nxt;
        }
        for (;;) {
                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;
        }
}

struct m_tag *
ip6_addaux(struct mbuf *m)
{
        struct m_tag *mtag;

        mtag = m_tag_find(m, PACKET_TAG_INET6, NULL);
        if (!mtag) {
                mtag = m_tag_get(PACKET_TAG_INET6, sizeof(struct ip6aux),
                    M_NOWAIT);
                if (mtag) {
                        m_tag_prepend(m, mtag);
                        memset(mtag + 1, 0, sizeof(struct ip6aux));
                }
        }
        return mtag;
}

struct m_tag *
ip6_findaux(struct mbuf *m)
{
        struct m_tag *mtag;

        mtag = m_tag_find(m, PACKET_TAG_INET6, NULL);
        return mtag;
}

void
ip6_delaux(struct mbuf *m)
{
        struct m_tag *mtag;

        mtag = m_tag_find(m, PACKET_TAG_INET6, NULL);
        if (mtag)
                m_tag_delete(m, mtag);
}

#ifdef GATEWAY
/* 
 * sysctl helper routine for net.inet.ip6.maxflows. Since
 * we could reduce this value, call ip6flow_reap();
 */
static int
sysctl_net_inet6_ip6_maxflows(SYSCTLFN_ARGS)
{  
        int error;
  
        error = sysctl_lookup(SYSCTLFN_CALL(rnode));
        if (error || newp == NULL)
                return (error);
 
        mutex_enter(softnet_lock);
        KERNEL_LOCK(1, NULL);

        ip6flow_reap(0);

        KERNEL_UNLOCK_ONE(NULL);
        mutex_exit(softnet_lock);
 
        return (0);
}

static int
sysctl_net_inet6_ip6_hashsize(SYSCTLFN_ARGS)
{  
        int error, tmp;
        struct sysctlnode node;

        node = *rnode;
        tmp = ip6_hashsize;
        node.sysctl_data = &tmp;
        error = sysctl_lookup(SYSCTLFN_CALL(&node));
        if (error || newp == NULL)
                return (error);

        if ((tmp & (tmp - 1)) == 0 && tmp != 0) {
                /*
                 * Can only fail due to malloc()
                 */
                mutex_enter(softnet_lock);
                KERNEL_LOCK(1, NULL);

                error = ip6flow_invalidate_all(tmp);

                KERNEL_UNLOCK_ONE(NULL);
                mutex_exit(softnet_lock);
        } else {
                /*
                 * EINVAL if not a power of 2
                 */
                error = EINVAL;
        }       

        return error;
}
#endif /* GATEWAY */

/*
 * System control for IP6
 */

const 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
};

static int
sysctl_net_inet6_ip6_stats(SYSCTLFN_ARGS)
{

        return (NETSTAT_SYSCTL(ip6stat_percpu, IP6_NSTATS));
}

static void
sysctl_net_inet6_ip6_setup(struct sysctllog **clog)
{
#ifdef RFC2292
#define IS2292(x, y)    ((in6p->in6p_flags & IN6P_RFC2292) ? (x) : (y))
#else
#define IS2292(x, y)    (y)
#endif

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "net", NULL,
                       NULL, 0, NULL, 0,
                       CTL_NET, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "inet6",
                       SYSCTL_DESCR("PF_INET6 related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET6, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_NODE, "ip6",
                       SYSCTL_DESCR("IPv6 related settings"),
                       NULL, 0, NULL, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6, CTL_EOL);

        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "forwarding",
                       SYSCTL_DESCR("Enable forwarding of INET6 datagrams"),
                       NULL, 0, &ip6_forwarding, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_FORWARDING, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "redirect",
                       SYSCTL_DESCR("Enable sending of ICMPv6 redirect messages"),
                       NULL, 0, &ip6_sendredirects, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_SENDREDIRECTS, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "hlim",
                       SYSCTL_DESCR("Hop limit for an INET6 datagram"),
                       NULL, 0, &ip6_defhlim, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_DEFHLIM, CTL_EOL);
#ifdef notyet
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "mtu", NULL,
                       NULL, 0, &, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_DEFMTU, CTL_EOL);
#endif
#ifdef __no_idea__
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "forwsrcrt", NULL,
                       NULL, 0, &?, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_FORWSRCRT, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_STRUCT, "mrtstats", NULL,
                       NULL, 0, &?, sizeof(?),
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_MRTSTATS, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_?, "mrtproto", NULL,
                       NULL, 0, &?, sizeof(?),
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_MRTPROTO, CTL_EOL);
#endif
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "maxfragpackets",
                       SYSCTL_DESCR("Maximum number of fragments to buffer "
                                    "for reassembly"),
                       NULL, 0, &ip6_maxfragpackets, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_MAXFRAGPACKETS, CTL_EOL);
#ifdef __no_idea__
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "sourcecheck", NULL,
                       NULL, 0, &?, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_SOURCECHECK, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "sourcecheck_logint", NULL,
                       NULL, 0, &?, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_SOURCECHECK_LOGINT, CTL_EOL);
#endif
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "accept_rtadv",
                       SYSCTL_DESCR("Accept router advertisements"),
                       NULL, 0, &ip6_accept_rtadv, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_ACCEPT_RTADV, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "keepfaith",
                       SYSCTL_DESCR("Activate faith interface"),
                       NULL, 0, &ip6_keepfaith, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_KEEPFAITH, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "log_interval",
                       SYSCTL_DESCR("Minumum interval between logging "
                                    "unroutable packets"),
                       NULL, 0, &ip6_log_interval, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_LOG_INTERVAL, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "hdrnestlimit",
                       SYSCTL_DESCR("Maximum number of nested IPv6 headers"),
                       NULL, 0, &ip6_hdrnestlimit, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_HDRNESTLIMIT, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "dad_count",
                       SYSCTL_DESCR("Number of Duplicate Address Detection "
                                    "probes to send"),
                       NULL, 0, &ip6_dad_count, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_DAD_COUNT, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "auto_flowlabel",
                       SYSCTL_DESCR("Assign random IPv6 flow labels"),
                       NULL, 0, &ip6_auto_flowlabel, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_AUTO_FLOWLABEL, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "defmcasthlim",
                       SYSCTL_DESCR("Default multicast hop limit"),
                       NULL, 0, &ip6_defmcasthlim, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_DEFMCASTHLIM, CTL_EOL);
#if NGIF > 0
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "gifhlim",
                       SYSCTL_DESCR("Default hop limit for a gif tunnel datagram"),
                       NULL, 0, &ip6_gif_hlim, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_GIF_HLIM, CTL_EOL);
#endif /* NGIF */
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_STRING, "kame_version",
                       SYSCTL_DESCR("KAME Version"),
                       NULL, 0, __UNCONST(__KAME_VERSION), 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_KAME_VERSION, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "use_deprecated",
                       SYSCTL_DESCR("Allow use of deprecated addresses as "
                                    "source addresses"),
                       NULL, 0, &ip6_use_deprecated, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_USE_DEPRECATED, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "rr_prune", NULL,
                       NULL, 0, &ip6_rr_prune, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_RR_PRUNE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT
#ifndef INET6_BINDV6ONLY
                       |CTLFLAG_READWRITE,
#endif
                       CTLTYPE_INT, "v6only",
                       SYSCTL_DESCR("Disallow PF_INET6 sockets from connecting "
                                    "to PF_INET sockets"),
                       NULL, 0, &ip6_v6only, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_V6ONLY, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "anonportmin",
                       SYSCTL_DESCR("Lowest ephemeral port number to assign"),
                       sysctl_net_inet_ip_ports, 0, &ip6_anonportmin, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_ANONPORTMIN, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "anonportmax",
                       SYSCTL_DESCR("Highest ephemeral port number to assign"),
                       sysctl_net_inet_ip_ports, 0, &ip6_anonportmax, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_ANONPORTMAX, CTL_EOL);
#ifndef IPNOPRIVPORTS
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "lowportmin",
                       SYSCTL_DESCR("Lowest privileged ephemeral port number "
                                    "to assign"),
                       sysctl_net_inet_ip_ports, 0, &ip6_lowportmin, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_LOWPORTMIN, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "lowportmax",
                       SYSCTL_DESCR("Highest privileged ephemeral port number "
                                    "to assign"),
                       sysctl_net_inet_ip_ports, 0, &ip6_lowportmax, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_LOWPORTMAX, CTL_EOL);
#endif /* IPNOPRIVPORTS */
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "use_tempaddr",
                       SYSCTL_DESCR("Use temporary address"),
                       NULL, 0, &ip6_use_tempaddr, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "temppltime",
                       SYSCTL_DESCR("preferred lifetime of a temporary address"),
                       NULL, 0, &ip6_temp_preferred_lifetime, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "tempvltime",
                       SYSCTL_DESCR("valid lifetime of a temporary address"),
                       NULL, 0, &ip6_temp_valid_lifetime, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "maxfrags",
                       SYSCTL_DESCR("Maximum fragments in reassembly queue"),
                       NULL, 0, &ip6_maxfrags, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_MAXFRAGS, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT,
                       CTLTYPE_STRUCT, "stats",
                       SYSCTL_DESCR("IPv6 statistics"),
                       sysctl_net_inet6_ip6_stats, 0, NULL, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_STATS, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "use_defaultzone",
                       SYSCTL_DESCR("Whether to use the default scope zones"),
                       NULL, 0, &ip6_use_defzone, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       IPV6CTL_USE_DEFAULTZONE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                       CTLTYPE_INT, "mcast_pmtu",
                       SYSCTL_DESCR("Enable pMTU discovery for multicast packet"),
                       NULL, 0, &ip6_mcast_pmtu, 0,
                       CTL_NET, PF_INET6, IPPROTO_IPV6,
                       CTL_CREATE, CTL_EOL);
#ifdef GATEWAY 
        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                        CTLTYPE_INT, "maxflows",
                        SYSCTL_DESCR("Number of flows for fast forwarding (IPv6)"),
                        sysctl_net_inet6_ip6_maxflows, 0, &ip6_maxflows, 0,
                        CTL_NET, PF_INET6, IPPROTO_IPV6,
                        CTL_CREATE, CTL_EOL);
        sysctl_createv(clog, 0, NULL, NULL,
                        CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
                        CTLTYPE_INT, "hashsize",
                        SYSCTL_DESCR("Size of hash table for fast forwarding (IPv6)"),
                        sysctl_net_inet6_ip6_hashsize, 0, &ip6_hashsize, 0,
                        CTL_NET, PF_INET6, IPPROTO_IPV6,
                        CTL_CREATE, CTL_EOL);
#endif
}

void
ip6_statinc(u_int stat)
{

        KASSERT(stat < IP6_NSTATS);
        IP6_STATINC(stat);
}