Logo Search packages:      
Sourcecode: ecos version File versions  Download package

ip6_output.c

//==========================================================================
//
//      src/sys/netinet6/ip6_output.c
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD, 
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// Portions created by Red Hat are
// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================

/*    $KAME: ip6_output.c,v 1.272 2001/12/26 01:03:28 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, 1990, 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_output.c   8.3 (Berkeley) 1/21/94
 */

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/errno.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/ip6_var.h>
#include <netinet/in_pcb.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6protosw.h>
#include <netinet6/scope6_var.h>

#ifdef IPSEC
#ifdef __OpenBSD__
#include <netinet/ip_ah.h>
#include <netinet/ip_esp.h>
#include <netinet/udp.h>
#include <netinet/tcp.h>
#include <net/pfkeyv2.h>

extern u_int8_t get_sa_require  __P((struct inpcb *));

extern int ipsec_auth_default_level;
extern int ipsec_esp_trans_default_level;
extern int ipsec_esp_network_default_level;
extern int ipsec_ipcomp_default_level;
#else
#include <netinet6/ipsec.h>
#include <netkey/key.h>
#endif
#endif /* IPSEC */

#if defined(IPV6FIREWALL) || (defined(__FreeBSD__) && __FreeBSD__ >= 4)
#include <netinet6/ip6_fw.h>
#endif

#ifdef MIP6
#include <sys/syslog.h>
#include <netinet6/mip6.h>
#endif /* MIP6 */

struct ip6_exthdrs {
      struct mbuf *ip6e_ip6;
      struct mbuf *ip6e_hbh;
      struct mbuf *ip6e_dest1;
      struct mbuf *ip6e_rthdr;
      struct mbuf *ip6e_haddr; /* for MIP6 */
      struct mbuf *ip6e_dest2;
};

static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **, int));
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
                      struct socket *, struct sockopt *));
static int ip6_getpcbopt __P((struct ip6_pktopts *, int, struct sockopt *));
#else
static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
                      struct socket *));
static int ip6_getpcbopt __P((struct ip6_pktopts *, int, struct mbuf **));
#endif
static int ip6_setpktoption __P((int, u_char *, int, struct ip6_pktopts *, int,
                         int, int));
static int ip6_setmoptions __P((int, struct ip6_moptions **, struct mbuf *));
static int ip6_getmoptions __P((int, struct ip6_moptions *, struct mbuf **));
static int ip6_copyexthdr __P((struct mbuf **, caddr_t, int));
static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
                          struct ip6_frag **));
static int ip6_insert_jumboopt __P((struct ip6_exthdrs *, u_int32_t));
static int ip6_splithdr __P((struct mbuf *, struct ip6_exthdrs *));
#ifdef NEW_STRUCT_ROUTE
static int ip6_getpmtu __P((struct route *, struct route *, struct ifnet *,
                      struct in6_addr *, u_long *));
#else
static int ip6_getpmtu __P((struct route *, struct route *, struct ifnet *,
                      struct in6_addr *, u_long *));
#endif

#ifdef __bsdi__
#if _BSDI_VERSION < 199802
extern struct ifnet loif;
#else
extern struct ifnet *loifp;
#endif
#endif
#if defined(__NetBSD__)
extern struct ifnet loif[NLOOP];
#endif


/*
 * IP6 output. The packet in mbuf chain m contains a skeletal IP6
 * header (with pri, len, nxt, hlim, src, dst).
 * This function may modify ver and hlim only.
 * The mbuf chain containing the packet will be freed.
 * The mbuf opt, if present, will not be freed.
 *
 * type of "mtu": rt_rmx.rmx_mtu is u_long, ifnet.ifr_mtu is int, and
 * nd_ifinfo.linkmtu is u_int32_t.  so we use u_long to hold largest one,
 * which is rt_rmx.rmx_mtu.
 */
int
ip6_output(m0, opt, ro, flags, im6o, ifpp)
      struct mbuf *m0;
      struct ip6_pktopts *opt;
#ifdef NEW_STRUCT_ROUTE
      struct route *ro;
#else
      struct route_in6 *ro;
#endif
      int flags;
      struct ip6_moptions *im6o;
      struct ifnet **ifpp;          /* XXX: just for statistics */
{
      struct ip6_hdr *ip6, *mhip6;
      struct ifnet *ifp, *origifp;
      struct mbuf *m = m0;
      int hlen, tlen, len, off;
#ifdef NEW_STRUCT_ROUTE
      struct route ip6route;
#else
      struct route_in6 ip6route;
#endif
      struct rtentry *rt = NULL;
      struct sockaddr_in6 *dst;
      int error = 0;
      struct in6_ifaddr *ia = NULL;
      u_long mtu;
      u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
      struct ip6_exthdrs exthdrs;
      struct in6_addr finaldst;
#ifdef NEW_STRUCT_ROUTE
      struct route *ro_pmtu = NULL;
#else
      struct route_in6 *ro_pmtu = NULL;
#endif
      int hdrsplit = 0;
#ifdef __OpenBSD__
      u_int8_t sproto = 0;
#else
      int needipsec = 0;
#endif
#if defined(__NetBSD__) && defined(PFIL_HOOKS)
      struct packet_filter_hook *pfh;
      struct mbuf *m1;
      int rv;
#endif /* PFIL_HOOKS */
#if defined(__bsdi__) && _BSDI_VERSION < 199802
      struct ifnet *loifp = &loif;
#endif
#ifdef MIP6
      struct mip6_pktopts mip6opt;
#ifdef NEW_STRUCT_ROUTE
      struct route mip6_ip6route;
#else
      struct route_in6 mip6_ip6route;
#endif
#endif /* MIP6 */
#ifdef IPSEC
#ifdef __OpenBSD__
      struct m_tag *mtag;
      union sockaddr_union sdst;
      struct tdb_ident *tdbi;
      u_int32_t sspi;
      struct inpcb *inp;
      struct tdb *tdb;
      int s;

      inp = NULL;     /* XXX */
      if (inp && (inp->inp_flags & INP_IPV6) == 0)
            panic("ip6_output: IPv4 pcb is passed");
#else
      int needipsectun = 0;
      struct socket *so;
      struct secpolicy *sp = NULL;

      /* for AH processing. stupid to have "socket" variable in IP layer... */
      so = ipsec_getsocket(m);
      (void)ipsec_setsocket(m, NULL);
      ip6 = mtod(m, struct ip6_hdr *);
#endif
#endif /* IPSEC */

#define MAKE_EXTHDR(hp, mp)                                 \
    do {                                              \
      if (hp) {                                       \
            struct ip6_ext *eh = (struct ip6_ext *)(hp);          \
            error = ip6_copyexthdr((mp), (caddr_t)(hp),           \
                               ((eh)->ip6e_len + 1) << 3);  \
            if (error)                                \
                  goto freehdrs;                            \
      }                                               \
    } while (0)
      
      bzero(&exthdrs, sizeof(exthdrs));

      if (opt) {
            /* Hop-by-Hop options header */
            MAKE_EXTHDR(opt->ip6po_hbh, &exthdrs.ip6e_hbh);
            /* Destination options header(1st part) */
            if (opt->ip6po_rthdr) {
                  /*
                   * Destination options header(1st part)
                   * This only makes sence with a routing header.
                   * See Section 9.2 of
                   * draft-ietf-ipngwg-rfc2292bis-02.txt.
                   * Disabling this part just for MIP6 convenience is
                   * a bad idea.  We need to think carefully about a
                   * way to make the advanced API coexist with MIP6
                   * options, which might automatically be inserted in
                   * the kernel.
                   */
                  MAKE_EXTHDR(opt->ip6po_dest1, &exthdrs.ip6e_dest1);
            }
            /* Routing header */
            MAKE_EXTHDR(opt->ip6po_rthdr, &exthdrs.ip6e_rthdr);
            /* Destination options header(2nd part) */
            MAKE_EXTHDR(opt->ip6po_dest2, &exthdrs.ip6e_dest2);
      }
#ifdef MIP6
      bzero((caddr_t)&mip6opt, sizeof(mip6opt));
      if ((flags & IPV6_FORWARDING) == 0) {
            /*
             * XXX: reconsider the following routine.
             */
            /*
             * MIP6 extention headers handling.
             * insert HA, BU, BA, BR options if necessary.
             */
            if (mip6_exthdr_create(m, opt, &mip6opt))
                  goto freehdrs;

            if (((opt != NULL) && (opt->ip6po_rthdr != NULL))
                || (mip6opt.mip6po_rthdr != NULL)) {
                  m_freem(exthdrs.ip6e_rthdr);
                  if (mip6opt.mip6po_rthdr != NULL) {
                        /*
                         * there is no rthdr specified in the
                         * ip6_pktopts.  but mip6 create a
                         * rthdr for the router optimization
                         * purpose.
                         */
                        MAKE_EXTHDR(mip6opt.mip6po_rthdr,
                                  &exthdrs.ip6e_rthdr);
                  } else {
                        /*
                         * there is a rthdr specified in the
                         * ip6_pktopts.  if mip6 require the
                         * route optimization, the rthdr for
                         * that purpose is already included in
                         * the ip6po_rthdr in the
                         * mip6_destopt_create().
                         */
                        MAKE_EXTHDR(opt->ip6po_rthdr,
                                  &exthdrs.ip6e_rthdr);
                  }
                  /*
                   * if a routing header exists dest1 must be
                   * inserted if it exists.
                   */
                  if ((opt != NULL) && (opt->ip6po_dest1)) {
                        m_freem(exthdrs.ip6e_dest1);
                        MAKE_EXTHDR(opt->ip6po_dest1,
                                  &exthdrs.ip6e_dest1);
                  }
            }
            MAKE_EXTHDR(mip6opt.mip6po_haddr, &exthdrs.ip6e_haddr);
            if (mip6opt.mip6po_dest2) {
                  m_freem(exthdrs.ip6e_dest2);
                  MAKE_EXTHDR(mip6opt.mip6po_dest2, &exthdrs.ip6e_dest2);
            }
      } else {
            /*
             * this is the forwarding packet.  do not modify any
             * extension headers.
             */
      }
#endif /* MIP6 */

#ifdef IPSEC
#ifdef __OpenBSD__
      /*
       * splnet is chosen over spltdb because we are not allowed to
       * lower the level, and udp6_output calls us in splnet(). XXX check
       */
      s = splnet();

      /*
       * Check if there was an outgoing SA bound to the flow
       * from a transport protocol.
       */
      ip6 = mtod(m, struct ip6_hdr *);

      /* Do we have any pending SAs to apply ? */
      mtag = m_tag_find(m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
      if (mtag != NULL) {
#ifdef DIAGNOSTIC
            if (mtag->m_tag_len != sizeof (struct tdb_ident))
                  panic("ip6_output: tag of length %d (should be %d",
                      mtag->m_tag_len, sizeof (struct tdb_ident));
#endif
            tdbi = (struct tdb_ident *)(mtag + 1);
            tdb = gettdb(tdbi->spi, &tdbi->dst, tdbi->proto);
            if (tdb == NULL)
                  error = -EINVAL;
            m_tag_delete(m, mtag);
      }
      else
            tdb = ipsp_spd_lookup(m, AF_INET6, sizeof(struct ip6_hdr),
                &error, IPSP_DIRECTION_OUT, NULL, inp);

      if (tdb == NULL) {
              splx(s);

            if (error == 0) {
                    /*
                   * No IPsec processing required, we'll just send the
                   * packet out.
                   */
                    sproto = 0;

                  /* Fall through to routing/multicast handling */
            } else {
                    /*
                   * -EINVAL is used to indicate that the packet should
                   * be silently dropped, typically because we've asked
                   * key management for an SA.
                   */
                    if (error == -EINVAL) /* Should silently drop packet */
                        error = 0;

                  goto freehdrs;
            }
      } else {
            /* Loop detection */
            for (mtag = m_tag_first(m); mtag != NULL;
                mtag = m_tag_next(m, mtag)) {
                  if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
                      mtag->m_tag_id !=
                      PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
                        continue;
                  tdbi = (struct tdb_ident *)(mtag + 1);
                  if (tdbi->spi == tdb->tdb_spi &&
                      tdbi->proto == tdb->tdb_sproto &&
                      !bcmp(&tdbi->dst, &tdb->tdb_dst,
                      sizeof(union sockaddr_union))) {
                        splx(s);
                        sproto = 0; /* mark as no-IPsec-needed */
                        goto done_spd;
                  }
            }

              /* We need to do IPsec */
              bcopy(&tdb->tdb_dst, &sdst, sizeof(sdst));
            sspi = tdb->tdb_spi;
            sproto = tdb->tdb_sproto;
              splx(s);

#if 1 /* XXX */
            /* if we have any extension header, we cannot perform IPsec */
            if (exthdrs.ip6e_hbh || exthdrs.ip6e_dest1 ||
#ifdef MIP6
                exthdrs.ip6e_haddr ||
#endif /* MIP6 */
                exthdrs.ip6e_rthdr || exthdrs.ip6e_dest2) {
                  error = EHOSTUNREACH;
                  goto freehdrs;
            }
#endif
      }

      /* Fall through to the routing/multicast handling code */
 done_spd:
#else
      /* get a security policy for this packet */
      if (so == NULL)
            sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error);
      else
            sp = ipsec6_getpolicybysock(m, IPSEC_DIR_OUTBOUND, so, &error);

      if (sp == NULL) {
            ipsec6stat.out_inval++;
            goto freehdrs;
      }

      error = 0;

      /* check policy */
      switch (sp->policy) {
      case IPSEC_POLICY_DISCARD:
            /*
             * This packet is just discarded.
             */
            ipsec6stat.out_polvio++;
            goto freehdrs;

      case IPSEC_POLICY_BYPASS:
      case IPSEC_POLICY_NONE:
            /* no need to do IPsec. */
            needipsec = 0;
            break;
      
      case IPSEC_POLICY_IPSEC:
            if (sp->req == NULL) {
                  /* acquire a policy */
                  error = key_spdacquire(sp);
                  goto freehdrs;
            }
            needipsec = 1;
            break;

      case IPSEC_POLICY_ENTRUST:
      default:
            printf("ip6_output: Invalid policy found. %d\n", sp->policy);
      }
#endif /* OpenBSD */
#endif /* IPSEC */

      /*
       * Calculate the total length of the extension header chain.
       * Keep the length of the unfragmentable part for fragmentation.
       */
      optlen = 0;
      if (exthdrs.ip6e_hbh) optlen += exthdrs.ip6e_hbh->m_len;
      if (exthdrs.ip6e_dest1) optlen += exthdrs.ip6e_dest1->m_len;
      if (exthdrs.ip6e_rthdr) optlen += exthdrs.ip6e_rthdr->m_len;
#ifdef MIP6
      if (exthdrs.ip6e_haddr) optlen += exthdrs.ip6e_haddr->m_len;
#endif /* MIP6 */
      unfragpartlen = optlen + sizeof(struct ip6_hdr);
      /* NOTE: we don't add AH/ESP length here. do that later. */
      if (exthdrs.ip6e_dest2) optlen += exthdrs.ip6e_dest2->m_len;

      /*
       * If we need IPsec, or there is at least one extension header,
       * separate IP6 header from the payload.
       */
#ifdef __OpenBSD__
      if ((sproto || optlen) && !hdrsplit)
#else
      if ((needipsec || optlen) && !hdrsplit)
#endif
      {
            if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
                  m = NULL;
                  goto freehdrs;
            }
            m = exthdrs.ip6e_ip6;
            hdrsplit++;
      }

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

      /* adjust mbuf packet header length */
      m->m_pkthdr.len += optlen;
      plen = m->m_pkthdr.len - sizeof(*ip6);

      /* If this is a jumbo payload, insert a jumbo payload option. */
      if (plen > IPV6_MAXPACKET) {
            if (!hdrsplit) {
                  if ((error = ip6_splithdr(m, &exthdrs)) != 0) {
                        m = NULL;
                        goto freehdrs;
                  }
                  m = exthdrs.ip6e_ip6;
                  hdrsplit++;
            }
            /* adjust pointer */
            ip6 = mtod(m, struct ip6_hdr *);
            if ((error = ip6_insert_jumboopt(&exthdrs, plen)) != 0)
                  goto freehdrs;
            ip6->ip6_plen = 0;
      } else
            ip6->ip6_plen = htons(plen);

      /*
       * Concatenate headers and fill in next header fields.
       * Here we have, on "m"
       *    IPv6 payload
       * and we insert headers accordingly.  Finally, we should be getting:
       *    IPv6 hbh dest1 rthdr ah* [esp* dest2 payload]
       *
       * during the header composing process, "m" points to IPv6 header.
       * "mprev" points to an extension header prior to esp.
       */
      {
            u_char *nexthdrp = &ip6->ip6_nxt;
            struct mbuf *mprev = m;

            /*
             * we treat dest2 specially.  this makes IPsec processing
             * much easier.  the goal here is to make mprev point the
             * mbuf prior to dest2.
             *
             * result: IPv6 dest2 payload
             * m and mprev will point to IPv6 header.
             */
            if (exthdrs.ip6e_dest2) {
                  if (!hdrsplit)
                        panic("assumption failed: hdr not split");
                  exthdrs.ip6e_dest2->m_next = m->m_next;
                  m->m_next = exthdrs.ip6e_dest2;
                  *mtod(exthdrs.ip6e_dest2, u_char *) = ip6->ip6_nxt;
                  ip6->ip6_nxt = IPPROTO_DSTOPTS;
            }

#define MAKE_CHAIN(m, mp, p, i)\
    do {\
      if (m) {\
            if (!hdrsplit) \
                  panic("assumption failed: hdr not split"); \
            *mtod((m), u_char *) = *(p);\
            *(p) = (i);\
            p = mtod((m), u_char *);\
            (m)->m_next = (mp)->m_next;\
            (mp)->m_next = (m);\
            (mp) = (m);\
      }\
    } while (0)
            /*
             * result: IPv6 hbh dest1 rthdr dest2 payload
             * m will point to IPv6 header.  mprev will point to the
             * extension header prior to dest2 (rthdr in the above case).
             */
            MAKE_CHAIN(exthdrs.ip6e_hbh, mprev,
                     nexthdrp, IPPROTO_HOPOPTS);
            MAKE_CHAIN(exthdrs.ip6e_dest1, mprev,
                     nexthdrp, IPPROTO_DSTOPTS);
            MAKE_CHAIN(exthdrs.ip6e_rthdr, mprev,
                     nexthdrp, IPPROTO_ROUTING);
#ifdef MIP6
            /*
             * XXX
             * MIP6 homeaddress destination option must reside
             * after rthdr and before ah/esp/frag hdr.
             * this order is not recommended in the ipv6 spec of course.
             * result: IPv6 hbh dest1 rthdr ha dest2 payload.
             */
            MAKE_CHAIN(exthdrs.ip6e_haddr, mprev,
                     nexthdrp, IPPROTO_DSTOPTS);
#endif /* MIP6 */

#if defined(IPSEC) && !defined(__OpenBSD__)
            if (!needipsec)
                  goto skip_ipsec2;

            /*
             * pointers after IPsec headers are not valid any more.
             * other pointers need a great care too.
             * (IPsec routines should not mangle mbufs prior to AH/ESP)
             */
            exthdrs.ip6e_dest2 = NULL;

          {
            struct ip6_rthdr *rh = NULL;
            int segleft_org = 0;
            struct ipsec_output_state state;

            if (exthdrs.ip6e_rthdr) {
                  rh = mtod(exthdrs.ip6e_rthdr, struct ip6_rthdr *);
                  segleft_org = rh->ip6r_segleft;
                  rh->ip6r_segleft = 0;
            }

            bzero(&state, sizeof(state));
            state.m = m;
            error = ipsec6_output_trans(&state, nexthdrp, mprev, sp, flags,
                  &needipsectun);
            m = state.m;
            if (error) {
                  /* mbuf is already reclaimed in ipsec6_output_trans. */
                  m = NULL;
                  switch (error) {
                  case EHOSTUNREACH:
                  case ENETUNREACH:
                  case EMSGSIZE:
                  case ENOBUFS:
                  case ENOMEM:
                        break;
                  default:
                        printf("ip6_output (ipsec): error code %d\n", error);
                        /* fall through */
                  case ENOENT:
                        /* don't show these error codes to the user */
                        error = 0;
                        break;
                  }
                  goto bad;
            }
            if (exthdrs.ip6e_rthdr) {
                  /* ah6_output doesn't modify mbuf chain */
                  rh->ip6r_segleft = segleft_org;
            }
          }
skip_ipsec2:;
#endif
      }

#ifdef MIP6
      if ((flags & IPV6_FORWARDING) == 0) {
            /*
             * After the IPsec processing the IPv6 header source
             * address (this is the homeaddress of this node) and
             * the address currently stored in the Home Address
             * destination option (this is the coa of this node)
             * must be swapped.
             */
            if ((error = mip6_addr_exchange(m, exthdrs.ip6e_haddr)) != 0) {
                  mip6log((LOG_ERR,
                         "%s:%d: "
                         "addr exchange between haddr and "
                         "coa failed.\n",
                         __FILE__, __LINE__));
                  goto bad;
            }
      } else {
            /*
             * this is the forwarding packet.  The typical (and
             * only ?) case is multicast packet forwarding.  The
             * swapping has been already done before (if
             * necessary).  we must not touch any extension
             * headers at all.
             */
      }
#endif /* MIP6 */

      /*
       * If there is a routing header, replace destination address field
       * with the first hop of the routing header.
       */
      if (exthdrs.ip6e_rthdr) {
            struct ip6_rthdr *rh =
                  (struct ip6_rthdr *)(mtod(exthdrs.ip6e_rthdr,
                                      struct ip6_rthdr *));
            struct ip6_rthdr0 *rh0;
            struct in6_addr *addr;

            finaldst = ip6->ip6_dst;
            switch (rh->ip6r_type) {
            case IPV6_RTHDR_TYPE_0:
                   rh0 = (struct ip6_rthdr0 *)rh;
                   addr = (struct in6_addr *)(rh0 + 1);

                   ip6->ip6_dst = *addr;
                   bcopy((caddr_t)(addr + 1), (caddr_t)addr,
                         sizeof(struct in6_addr) * (rh0->ip6r0_segleft - 1)
                         );
                   *(addr + rh0->ip6r0_segleft - 1) = finaldst;
                   break;
            default:    /* is it possible? */
                   error = EINVAL;
                   goto bad;
            }
      }

      /* Source address validation */
      if (!(flags & IPV6_UNSPECSRC) &&
          IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src)) {
            /*
             * XXX: we can probably assume validation in the caller, but
             * we explicitly check the address here for safety.
             */
            error = EOPNOTSUPP;
            ip6stat.ip6s_badscope++;
            goto bad;
      }
      if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
            error = EOPNOTSUPP;
            ip6stat.ip6s_badscope++;
            goto bad;
      }

      ip6stat.ip6s_localout++;

      /*
       * Route packet.
       */
      if (ro == 0) {
            ro = &ip6route;
            bzero((caddr_t)ro, sizeof(*ro));
      }
      ro_pmtu = ro;
      if (opt && opt->ip6po_rthdr)
            ro = &opt->ip6po_route;
#ifdef MIP6
      else if (exthdrs.ip6e_rthdr) {
            struct sockaddr_in6 *firsthop;
            struct ip6_hdr *ip6
                  = mtod(m, struct ip6_hdr *); /* needed ? */;

            ro = &mip6_ip6route;
            bzero((caddr_t)ro, sizeof(*ro));
            firsthop = (struct sockaddr_in6 *)&ro->ro_dst;
            bzero(firsthop, sizeof(*firsthop));
            firsthop->sin6_family = AF_INET6;
            firsthop->sin6_len = sizeof(struct sockaddr_in6);
            firsthop->sin6_addr = ip6->ip6_dst;
      }
#endif /* MIP6 */
      dst = (struct sockaddr_in6 *)&ro->ro_dst;

#ifdef IPSEC
#ifdef __OpenBSD__
      /*
       * Check if the packet needs encapsulation.
       * ipsp_process_packet will never come back to here.
       */
      if (sproto != 0) {
              s = splnet();

            /* fill in IPv6 header which would be filled later */
            if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
                  if (opt && opt->ip6po_hlim != -1)
                        ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
            } else {
                  if (im6o != NULL)
                        ip6->ip6_hlim = im6o->im6o_multicast_hlim;
                  else
                        ip6->ip6_hlim = ip6_defmcasthlim;
                  if (opt && opt->ip6po_hlim != -1)
                        ip6->ip6_hlim = opt->ip6po_hlim & 0xff;

                  /*
                   * XXX what should we do if ip6_hlim == 0 and the packet
                   * gets tunnelled?
                   */
            }

            tdb = gettdb(sspi, &sdst, sproto);
            if (tdb == NULL) {
                  splx(s);
                  error = EHOSTUNREACH;
                  m_freem(m);
                  goto done;
            }

            /* Latch to PCB */
            if (inp)
                  tdb_add_inp(tdb, inp, 0);

            m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */

            /* Callee frees mbuf */
            error = ipsp_process_packet(m, tdb, AF_INET6, 0);
            splx(s);

            return error;  /* Nothing more to be done */
      }
#else
      if (needipsec && needipsectun) {
            struct ipsec_output_state state;

            /*
             * All the extension headers will become inaccessible
             * (since they can be encrypted).
             * Don't panic, we need no more updates to extension headers
             * on inner IPv6 packet (since they are now encapsulated).
             *
             * IPv6 [ESP|AH] IPv6 [extension headers] payload
             */
            bzero(&exthdrs, sizeof(exthdrs));
            exthdrs.ip6e_ip6 = m;

            bzero(&state, sizeof(state));
            state.m = m;
            state.ro = (struct route *)ro;
            state.dst = (struct sockaddr *)dst;

            error = ipsec6_output_tunnel(&state, sp, flags);

            m = state.m;
#ifdef NEW_STRUCT_ROUTE
            ro = state.ro;
#else
            ro = (struct route_in6 *)state.ro;
#endif
            dst = (struct sockaddr_in6 *)state.dst;
            if (error) {
                  /* mbuf is already reclaimed in ipsec6_output_tunnel. */
                  m0 = m = NULL;
                  m = NULL;
                  switch (error) {
                  case EHOSTUNREACH:
                  case ENETUNREACH:
                  case EMSGSIZE:
                  case ENOBUFS:
                  case ENOMEM:
                        break;
                  default:
                        printf("ip6_output (ipsec): error code %d\n", error);
                        /* fall through */
                  case ENOENT:
                        /* don't show these error codes to the user */
                        error = 0;
                        break;
                  }
                  goto bad;
            }

            exthdrs.ip6e_ip6 = m;
      }
#endif /* OpenBSD */
#endif /* IPSEC */

      /* if specified, fill in the traffic class field. */
      if (opt) {
            ip6->ip6_flow &= ~htonl(0xff << 20);
            if (opt->ip6po_tclass >= 0)
                  ip6->ip6_flow |=
                      htonl((opt->ip6po_tclass & 0xff) << 20);
      }
      /* fill in or override the hop limit field, if necessary. */
      if (opt && opt->ip6po_hlim != -1)
            ip6->ip6_hlim = opt->ip6po_hlim & 0xff;
      else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
            if (im6o != NULL)
                  ip6->ip6_hlim = im6o->im6o_multicast_hlim;
            else
                  ip6->ip6_hlim = ip6_defmcasthlim;
      }

      {
            /*
             * XXX: using a block just to define a local variables is not
             * a good style....
             */
            struct ifnet *ifp0 = NULL;
            struct sockaddr_in6 src;
            struct sockaddr_in6 dst0;
            int clone = 0;
            int64_t zone;

            /*
             * XXX: sockaddr_in6 for the destination should be passed
             * from the upper layer with a proper scope zone ID, in order
             * to make a copy here. 
             */
            bzero(&dst0, sizeof(dst0));
            dst0.sin6_family = AF_INET6;
            dst0.sin6_len = sizeof(dst0);
            dst0.sin6_addr = ip6->ip6_dst;
#ifdef SCOPEDROUTING
            /* XXX: in6_recoverscope will clear the embedded ID */
            error = in6_recoverscope(&dst0, &dst0.sin6_addr, NULL);
            if (error != 0) {
                  ip6stat.ip6s_badscope++;
                  in6_ifstat_inc(ifp, ifs6_out_discard);
                  goto bad;
            }
#endif

#if defined(__bsdi__) || defined(__FreeBSD__)
            if (ro != &ip6route && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
                  clone = 1;
#endif

            if ((error = in6_selectroute(&dst0, opt, im6o, ro,
                                   &ifp, &rt, clone)) != 0) {
                  switch (error) {
                  case EHOSTUNREACH:
                        ip6stat.ip6s_noroute++;
                        break;
                  case EADDRNOTAVAIL:
                  default:
                        break; /* XXX statistics? */
                  }
                  if (ifp != NULL)
                        in6_ifstat_inc(ifp, ifs6_out_discard);
                  goto bad;
            }
            if (rt == NULL) {
                  /*
                   * If in6_selectroute() does not return a route entry,
                   * dst may not have been updated. 
                   */
                  *dst = dst0;      /* XXX */
            }

            /*
             * then rt (for unicast) and ifp must be non-NULL valid values.
             */
            if ((flags & IPV6_FORWARDING) == 0) {
                  /* XXX: the FORWARDING flag can be set for mrouting. */
                  in6_ifstat_inc(ifp, ifs6_out_request);
            }
            if (rt != NULL) {
                  ia = (struct in6_ifaddr *)(rt->rt_ifa);
                  rt->rt_use++;
            }

            /*
             * The outgoing interface must be in the zone of source and
             * destination addresses.  We should use ia_ifp to support the
             * case of sending packets to an address of our own.
             */
            if (ia != NULL && ia->ia_ifp)
                  ifp0 = ia->ia_ifp;
            else
                  ifp0 = ifp;
            /* XXX: we should not do this conversion for every packet. */
            bzero(&src, sizeof(src));
            src.sin6_family = AF_INET6;
            src.sin6_len = sizeof(src);
            src.sin6_addr = ip6->ip6_src;
            if ((error = in6_recoverscope(&src, &ip6->ip6_src, NULL))
                != 0) {
                  goto badscope;
            }
            if ((zone = in6_addr2zoneid(ifp0, &src.sin6_addr)) < 0 ||
                zone != src.sin6_scope_id) {
#ifdef SCOPEDEBUG       /* will be removed shortly */
                  printf("ip6 output: bad source scope %s for %s on %s\n",
                         ip6_sprintf(&ip6->ip6_src),
                         ip6_sprintf(&ip6->ip6_dst), if_name(ifp0));
#endif
                  goto badscope;
            }
            /* XXX: in6_recoverscope will clear the embedded ID */
            if ((error = in6_recoverscope(&dst0, &ip6->ip6_dst, NULL))
                != 0) {
                  goto badscope;
            }
            if ((zone = in6_addr2zoneid(ifp0, &dst0.sin6_addr)) < 0 ||
                zone != dst0.sin6_scope_id) {
#ifdef SCOPEDEBUG       /* will be removed shortly */
                  printf("ip6 output: bad dst scope %s on %s\n",
                         ip6_sprintf(&dst0.sin6_addr), if_name(ifp0));
#endif
                  goto badscope;
            }

            /* scope check is done. */
            goto routefound;

        badscope:
            ip6stat.ip6s_badscope++;
            in6_ifstat_inc(ifp0, ifs6_out_discard);
            if (error == 0)
                  error = EHOSTUNREACH; /* XXX */
            goto bad;
      }

  routefound:
      if (rt) {
            if (opt && opt->ip6po_nextroute.ro_rt) {
                  /*
                   * The nexthop is explicitly specified by the
                   * application.  We assume the next hop is an IPv6
                   * address.
                   */
                  dst = (struct sockaddr_in6 *)opt->ip6po_nexthop;
            }
            else if ((rt->rt_flags & RTF_GATEWAY))
                  dst = (struct sockaddr_in6 *)rt->rt_gateway;
      }

      if (!IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
            m->m_flags &= ~(M_BCAST | M_MCAST); /* just in case */
      } else {
            struct      in6_multi *in6m;

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

            in6_ifstat_inc(ifp, ifs6_out_mcast);

            /*
             * Confirm that the outgoing interface supports multicast.
             */
            if (!(ifp->if_flags & IFF_MULTICAST)) {
                  ip6stat.ip6s_noroute++;
                  in6_ifstat_inc(ifp, ifs6_out_discard);
                  error = ENETUNREACH;
                  goto bad;
            }
            IN6_LOOKUP_MULTI(ip6->ip6_dst, ifp, in6m);
            if (in6m != NULL &&
               (im6o == NULL || im6o->im6o_multicast_loop)) {
                  /*
                   * If we belong to the destination multicast group
                   * on the outgoing interface, and the caller did not
                   * forbid loopback, loop back a copy.
                   */
                  ip6_mloopback(ifp, m, dst);
            } else {
                  /*
                   * If we are acting as a multicast router, perform
                   * multicast forwarding as if the packet had just
                   * arrived on the interface to which we are about
                   * to send.  The multicast forwarding function
                   * recursively calls this function, using the
                   * IPV6_FORWARDING flag to prevent infinite recursion.
                   *
                   * Multicasts that are looped back by ip6_mloopback(),
                   * above, will be forwarded by the ip6_input() routine,
                   * if necessary.
                   */
                  if (ip6_mrouter && (flags & IPV6_FORWARDING) == 0) {
                        /*
                         * XXX: ip6_mforward expects that rcvif is NULL
                         * when it is called from the originating path.
                         * However, it is not always the case, since
                         * some versions of MGETHDR() does not
                         * initialize the field.  
                         */
                        m->m_pkthdr.rcvif = NULL;
                        if (ip6_mforward(ip6, ifp, m) != 0) {
                              m_freem(m);
                              goto done;
                        }
                  }
            }
            /*
             * Multicasts with a hoplimit of zero may be looped back,
             * above, but must not be transmitted on a network.
             * Also, multicasts addressed to the loopback interface
             * are not sent -- the above call to ip6_mloopback() will
             * loop back a copy if this host actually belongs to the
             * destination group on the loopback interface.
             */
            if (ip6->ip6_hlim == 0 || (ifp->if_flags & IFF_LOOPBACK) ||
                IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
                  m_freem(m);
                  goto done;
            }
      }

      /*
       * Fill the outgoing inteface to tell the upper layer
       * to increment per-interface statistics.
       */
      if (ifpp)
            *ifpp = ifp;

      /*
       * Upper-layer reachability confirmation
       */
      if (opt && (opt->ip6po_flags & IP6PO_REACHCONF))
            nd6_nud_hint(rt, NULL, 0);

      /* Determine path MTU. */
      if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu)) != 0)
            goto bad;

      /*
       * An advanced API option (IPV6_USE_MIN_MTU) overrides mtu setting.
       * We ignore the specified MTU if it is larger than the already-known
       * path MTU.
       */
      if (mtu > IPV6_MMTU && opt && (opt->ip6po_flags & IP6PO_MINMTU))
            mtu = IPV6_MMTU;

      /* Fake scoped addresses */
      if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
            /*
             * If source or destination address is a scoped address, and
             * the packet is going to be sent to a loopback interface,
             * we should keep the original interface.
             */

            /*
             * XXX: this is a very experimental and temporary solution.
             * We eventually have sockaddr_in6 and use the sin6_scope_id
             * field of the structure here.
             * We rely on the consistency between two scope zone ids
             * of source and destination, which should already be assured.
             * Larger scopes than link will be supported in the future. 
             */
            origifp = NULL;
            if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
                  origifp = ifnet_byindex(ntohs(ip6->ip6_src.s6_addr16[1]));
#else
                  origifp = ifindex2ifnet[ntohs(ip6->ip6_src.s6_addr16[1])];
#endif
            } else if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
                  origifp = ifnet_byindex(ntohs(ip6->ip6_dst.s6_addr16[1]));
#else
                  origifp = ifindex2ifnet[ntohs(ip6->ip6_dst.s6_addr16[1])];
#endif
            } else if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst)) {
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
                  origifp = ifnet_byindex(ntohs(ip6->ip6_dst.s6_addr16[1]));
#else
                  origifp = ifindex2ifnet[ntohs(ip6->ip6_dst.s6_addr16[1])];
#endif
            }

            /*
             * XXX: origifp can be NULL even in those two cases above.
             * For example, if we remove the (only) link-local address
             * from the loopback interface, and try to send a link-local
             * address without link-id information.  Then the source
             * address is ::1, and the destination address is the
             * link-local address with its s6_addr16[1] being zero.
             * What is worse, if the packet goes to the loopback interface
             * by a default rejected route, the null pointer would be
             * passed to looutput, and the kernel would hang.
             * The following last resort would prevent such disaster.
             */
            if (origifp == NULL)
                  origifp = ifp;
      }
      else
            origifp = ifp;
#ifndef SCOPEDROUTING
      /*
       * clear embedded scope identifiers if necessary.
       * in6_clearscope will touch the addresses only when necessary.
       */
      in6_clearscope(&ip6->ip6_src);
      in6_clearscope(&ip6->ip6_dst);
#endif

#if defined(IPV6FIREWALL) || (defined(__FreeBSD__) && __FreeBSD__ >= 4)
      /*
       * Check with the firewall...
       */
#if defined(__FreeBSD__) && __FreeBSD__ >= 4
      if (ip6_fw_enable && ip6_fw_chk_ptr) {
#else
      if (ip6_fw_chk_ptr) {
#endif
            m->m_pkthdr.rcvif = NULL;     /* XXX */
            /* If ipfw says divert, we have to just drop packet */
            if ((*ip6_fw_chk_ptr)(&ip6, ifp, &m)) {
                  m_freem(m);
                  goto done;
            }
            if (!m) {
                  error = EACCES;
                  goto done;
            }
      }
#endif

      /*
       * If the outgoing packet contains a hop-by-hop options header,
       * it must be examined and processed even by the source node.
       * (RFC 2460, section 4.)
       */
      if (exthdrs.ip6e_hbh) {
            struct ip6_hbh *hbh = mtod(exthdrs.ip6e_hbh, struct ip6_hbh *);
            u_int32_t dummy; /* XXX unused */
            u_int32_t plen = 0; /* XXX: ip6_process will check the value */

#ifdef DIAGNOSTIC
            if ((hbh->ip6h_len + 1) << 3 > exthdrs.ip6e_hbh->m_len)
                  panic("ip6e_hbh is not continuous");
#endif
            /*
             *  XXX: if we have to send an ICMPv6 error to the sender,
             *       we need the M_LOOP flag since icmp6_error() expects
             *       the IPv6 and the hop-by-hop options header are
             *       continuous unless the flag is set.
             */
            m->m_flags |= M_LOOP;
            m->m_pkthdr.rcvif = ifp;
            if (ip6_process_hopopts(m,
                              (u_int8_t *)(hbh + 1),
                              ((hbh->ip6h_len + 1) << 3) -
                              sizeof(struct ip6_hbh),
                              &dummy, &plen) < 0) {
                  /* m was already freed at this point */
                  error = EINVAL;/* better error? */
                  goto done;
            }
            m->m_flags &= ~M_LOOP; /* XXX */
            m->m_pkthdr.rcvif = NULL;
      }

#if defined(__NetBSD__) && defined(PFIL_HOOKS)
      /*
       * Run through list of hooks for output packets.
       */
      m1 = m;
      pfh = pfil_hook_get(PFIL_OUT, &inetsw[ip_protox[IPPROTO_IPV6]].pr_pfh);
      for (; pfh; pfh = pfh->pfil_link.tqe_next)
            if (pfh->pfil_func) {
                  rv = pfh->pfil_func(ip6, sizeof(*ip6), ifp, 1, &m1);
                  if (rv) {
                        error = EHOSTUNREACH;
                        goto done;
                  }
                  m = m1;
                  if (m == NULL)
                        goto done;
                  ip6 = mtod(m, struct ip6_hdr *);
            }
#endif /* PFIL_HOOKS */

#if defined(__OpenBSD__) && NPF > 0
      if (pf_test6(PF_OUT, ifp, &m) != PF_PASS) {
            error = EHOSTUNREACH;
            m_freem(m);
            goto done;
      }
      ip6 = mtod(m, struct ip6_hdr *);
#endif 

      /*
       * Send the packet to the outgoing interface.
       * If necessary, do IPv6 fragmentation before sending.
       */
      tlen = m->m_pkthdr.len;
      /*
       * Even if the DONTFRAG option is specified, we cannot send the packet
       * when the data length is larger than the MTU of the outgoing
       * interface.
       * Notify the error by sending IPV6_PATHMTU ancillary data as well
       * as returning an error code (the latter is not described in the API
       * spec.)
       */
      if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG) && tlen > ifp->if_mtu
#ifdef notyet
          && !(ifp->if_flags & IFF_FRAGMENTABLE)
#endif
            ) {
            u_int32_t mtu32;
            struct ip6ctlparam ip6cp;

            mtu32 = (u_int32_t)mtu;
            bzero(&ip6cp, sizeof(ip6cp));
            ip6cp.ip6c_cmdarg = (void *)&mtu32;
            pfctlinput2(PRC_MSGSIZE, &ro_pmtu->ro_dst, (void *)&ip6cp);

            error = EMSGSIZE;
            goto bad;
      }
      if (tlen <= mtu || (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
#ifdef notyet
          /*
           * On any link that cannot convey a 1280-octet packet in one piece,
           * link-specific fragmentation and reassembly must be provided at
           * a layer below IPv6. [RFC 2460, sec.5]
           * Thus if the interface has ability of link-level fragmentation,
           * we can just send the packet even if the packet size is
           * larger than the link's MTU.
           * XXX: IFF_FRAGMENTABLE (or such) flag has not been defined yet...
           */
      
          || (ifp->if_flags & IFF_FRAGMENTABLE)
#endif
          )
      {
            struct in6_ifaddr *ia6;

            ip6 = mtod(m, struct ip6_hdr *);
            ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
            if (ia6) {
                  /* Record statistics for this interface address. */
#if defined(__NetBSD__) && defined(IFA_STATS)
                  ia6->ia_ifa.ifa_data.ifad_outbytes +=
                        m->m_pkthdr.len;
#elif defined(__FreeBSD__) && __FreeBSD__ >= 4
                  ia6->ia_ifa.if_opackets++;
                  ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
#elif defined(__bsdi__) && _BSDI_VERSION >= 199802
                  ia6->ia_ifa.ifa_opackets++;
                  ia6->ia_ifa.ifa_obytes += m->m_pkthdr.len;
#endif
            }
#if defined(IPSEC) && !defined(__OpenBSD__)
            /* clean ipsec history once it goes out of the node */
            ipsec_delaux(m);
#endif
            error = nd6_output(ifp, origifp, m, dst, rt);
            goto done;
      } else if (mtu < IPV6_MMTU) {
            /*
             * note that path MTU is never less than IPV6_MMTU
             * (see icmp6_input).
             */
            error = EMSGSIZE;
            in6_ifstat_inc(ifp, ifs6_out_fragfail);
            goto bad;
      } else if (ip6->ip6_plen == 0) { /* jumbo payload cannot be fragmented */
            error = EMSGSIZE;
            in6_ifstat_inc(ifp, ifs6_out_fragfail);
            goto bad;
      } else {
            struct mbuf **mnext, *m_frgpart;
            struct ip6_frag *ip6f;
            u_int32_t id = htonl(ip6_id++);
            u_char nextproto;
            struct ip6ctlparam ip6cp;
            u_int32_t mtu32;

            /*
             * Too large for the destination or interface;
             * fragment if possible.
             * Must be able to put at least 8 bytes per fragment.
             */
            hlen = unfragpartlen;
            if (mtu > IPV6_MAXPACKET)
                  mtu = IPV6_MAXPACKET;

            /* Notify a proper path MTU to applications. */
            mtu32 = (u_int32_t)mtu;
            bzero(&ip6cp, sizeof(ip6cp));
            ip6cp.ip6c_cmdarg = (void *)&mtu32;
            pfctlinput2(PRC_MSGSIZE, &ro_pmtu->ro_dst, (void *)&ip6cp);

            len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
            if (len < 8) {
                  error = EMSGSIZE;
                  in6_ifstat_inc(ifp, ifs6_out_fragfail);
                  goto bad;
            }

            mnext = &m->m_nextpkt;

            /*
             * Change the next header field of the last header in the
             * unfragmentable part.
             */
#ifdef MIP6
            if (exthdrs.ip6e_haddr) {
                  nextproto = *mtod(exthdrs.ip6e_haddr, u_char *);
                  *mtod(exthdrs.ip6e_haddr, u_char *) = IPPROTO_FRAGMENT;
            } else
#endif /* MIP6 */
            if (exthdrs.ip6e_rthdr) {
                  nextproto = *mtod(exthdrs.ip6e_rthdr, u_char *);
                  *mtod(exthdrs.ip6e_rthdr, u_char *) = IPPROTO_FRAGMENT;
            } else if (exthdrs.ip6e_dest1) {
                  nextproto = *mtod(exthdrs.ip6e_dest1, u_char *);
                  *mtod(exthdrs.ip6e_dest1, u_char *) = IPPROTO_FRAGMENT;
            } else if (exthdrs.ip6e_hbh) {
                  nextproto = *mtod(exthdrs.ip6e_hbh, u_char *);
                  *mtod(exthdrs.ip6e_hbh, u_char *) = IPPROTO_FRAGMENT;
            } else {
                  nextproto = ip6->ip6_nxt;
                  ip6->ip6_nxt = IPPROTO_FRAGMENT;
            }

            /*
             * Loop through length of segment after first fragment,
             * make new header and copy data of each part and link onto
             * chain.
             */
            m0 = m;
            for (off = hlen; off < tlen; off += len) {
                  MGETHDR(m, M_DONTWAIT, MT_HEADER);
                  if (!m) {
                        error = ENOBUFS;
                        ip6stat.ip6s_odropped++;
                        goto sendorfree;
                  }
                  m->m_pkthdr.rcvif = NULL;
                  m->m_flags = m0->m_flags & M_COPYFLAGS;
                  *mnext = m;
                  mnext = &m->m_nextpkt;
                  m->m_data += max_linkhdr;
                  mhip6 = mtod(m, struct ip6_hdr *);
                  *mhip6 = *ip6;
                  m->m_len = sizeof(*mhip6);
                  error = ip6_insertfraghdr(m0, m, hlen, &ip6f);
                  if (error) {
                        ip6stat.ip6s_odropped++;
                        goto sendorfree;
                  }
                  ip6f->ip6f_offlg = htons((u_short)((off - hlen) & ~7));
                  if (off + len >= tlen)
                        len = tlen - off;
                  else
                        ip6f->ip6f_offlg |= IP6F_MORE_FRAG;
                  mhip6->ip6_plen = htons((u_short)(len + hlen +
                                            sizeof(*ip6f) -
                                            sizeof(struct ip6_hdr)));
                  if ((m_frgpart = m_copy(m0, off, len)) == 0) {
                        error = ENOBUFS;
                        ip6stat.ip6s_odropped++;
                        goto sendorfree;
                  }
                  m_cat(m, m_frgpart);
                  m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
                  m->m_pkthdr.rcvif = (struct ifnet *)0;
                  ip6f->ip6f_reserved = 0;
                  ip6f->ip6f_ident = id;
                  ip6f->ip6f_nxt = nextproto;
                  ip6stat.ip6s_ofragments++;
                  in6_ifstat_inc(ifp, ifs6_out_fragcreat);
            }

            in6_ifstat_inc(ifp, ifs6_out_fragok);
      }

      /*
       * Remove leading garbages.
       */
sendorfree:
      m = m0->m_nextpkt;
      m0->m_nextpkt = 0;
      m_freem(m0);
      for (m0 = m; m; m = m0) {
            m0 = m->m_nextpkt;
            m->m_nextpkt = 0;
            if (error == 0) {
                  struct in6_ifaddr *ia6;
                  ip6 = mtod(m, struct ip6_hdr *);
                  ia6 = in6_ifawithifp(ifp, &ip6->ip6_src);
                  if (ia6) {
                        /*
                         * Record statistics for this interface
                         * address.
                         */
#if defined(__NetBSD__) && defined(IFA_STATS)
                        ia6->ia_ifa.ifa_data.ifad_outbytes +=
                              m->m_pkthdr.len;
#elif defined(__FreeBSD__) && __FreeBSD__ >= 4
                        ia6->ia_ifa.if_opackets++;
                        ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
#elif defined(__bsdi__) && _BSDI_VERSION >= 199802
                        ia6->ia_ifa.ifa_opackets++;
                        ia6->ia_ifa.ifa_obytes += m->m_pkthdr.len;
#endif
                  }
#if defined(IPSEC) && !defined(__OpenBSD__)
                  /* clean ipsec history once it goes out of the node */
                  ipsec_delaux(m);
#endif
                  error = nd6_output(ifp, origifp, m, dst, rt);
            } else
                  m_freem(m);
      }

      if (error == 0)
            ip6stat.ip6s_fragmented++;

done:
      if (ro == &ip6route && ro->ro_rt) { /* brace necessary for RTFREE */
            RTFREE(ro->ro_rt);
      } else if (ro_pmtu == &ip6route && ro_pmtu->ro_rt) {
            RTFREE(ro_pmtu->ro_rt);
      }

#if defined(IPSEC) && !defined(__OpenBSD__)
      if (sp != NULL)
            key_freesp(sp);
#endif /* IPSEC */

#ifdef MIP6
      mip6_destopt_discard(&mip6opt);
#endif /* MIP6 */

      return(error);

freehdrs:
#ifdef MIP6
      mip6_destopt_discard(&mip6opt);
#endif /* MIP6 */
      m_freem(exthdrs.ip6e_hbh);    /* m_freem will check if mbuf is 0 */
      m_freem(exthdrs.ip6e_dest1);
      m_freem(exthdrs.ip6e_rthdr);
#ifdef MIP6
      m_freem(exthdrs.ip6e_haddr);
#endif /* MIP6 */
      m_freem(exthdrs.ip6e_dest2);
      /* fall through */
bad:
      m_freem(m);
      goto done;
}

static int
ip6_copyexthdr(mp, hdr, hlen)
      struct mbuf **mp;
      caddr_t hdr;
      int hlen;
{
      struct mbuf *m;

      if (hlen > MCLBYTES)
            return(ENOBUFS); /* XXX */

      MGET(m, M_DONTWAIT, MT_DATA);
      if (!m)
            return(ENOBUFS);

      if (hlen > MLEN) {
            MCLGET(m, M_DONTWAIT);
            if ((m->m_flags & M_EXT) == 0) {
                  m_free(m);
                  return(ENOBUFS);
            }
      }
      m->m_len = hlen;
      if (hdr)
            bcopy(hdr, mtod(m, caddr_t), hlen);

      *mp = m;
      return(0);
}

/*
 * Insert jumbo payload option.
 */
static int
ip6_insert_jumboopt(exthdrs, plen)
      struct ip6_exthdrs *exthdrs;
      u_int32_t plen;
{
      struct mbuf *mopt;
      u_char *optbuf;
      u_int32_t v;

#define JUMBOOPTLEN     8     /* length of jumbo payload option and padding */

      /*
       * If there is no hop-by-hop options header, allocate new one.
       * If there is one but it doesn't have enough space to store the
       * jumbo payload option, allocate a cluster to store the whole options.
       * Otherwise, use it to store the options.
       */
      if (exthdrs->ip6e_hbh == 0) {
            MGET(mopt, M_DONTWAIT, MT_DATA);
            if (mopt == 0)
                  return(ENOBUFS);
            mopt->m_len = JUMBOOPTLEN;
            optbuf = mtod(mopt, u_char *);
            optbuf[1] = 0;    /* = ((JUMBOOPTLEN) >> 3) - 1 */
            exthdrs->ip6e_hbh = mopt;
      } else {
            struct ip6_hbh *hbh;

            mopt = exthdrs->ip6e_hbh;
            if (M_TRAILINGSPACE(mopt) < JUMBOOPTLEN) {
                  /*
                   * XXX assumption:
                   * - exthdrs->ip6e_hbh is not referenced from places
                   *   other than exthdrs.
                   * - exthdrs->ip6e_hbh is not an mbuf chain.
                   */
                  int oldoptlen = mopt->m_len;
                  struct mbuf *n;

                  /*
                   * XXX: give up if the whole (new) hbh header does
                   * not fit even in an mbuf cluster.
                   */
                  if (oldoptlen + JUMBOOPTLEN > MCLBYTES)
                        return(ENOBUFS);

                  /*
                   * As a consequence, we must always prepare a cluster
                   * at this point.
                   */
                  MGET(n, M_DONTWAIT, MT_DATA);
                  if (n) {
                        MCLGET(n, M_DONTWAIT);
                        if ((n->m_flags & M_EXT) == 0) {
                              m_freem(n);
                              n = NULL;
                        }
                  }
                  if (!n)
                        return(ENOBUFS);
                  n->m_len = oldoptlen + JUMBOOPTLEN;
                  bcopy(mtod(mopt, caddr_t), mtod(n, caddr_t),
                        oldoptlen);
                  optbuf = mtod(n, caddr_t) + oldoptlen;
                  m_freem(mopt);
                  mopt = exthdrs->ip6e_hbh = n;
            } else {
                  optbuf = mtod(mopt, u_char *) + mopt->m_len;
                  mopt->m_len += JUMBOOPTLEN;
            }
            optbuf[0] = IP6OPT_PADN;
            optbuf[1] = 1;

            /*
             * Adjust the header length according to the pad and
             * the jumbo payload option.
             */
            hbh = mtod(mopt, struct ip6_hbh *);
            hbh->ip6h_len += (JUMBOOPTLEN >> 3);
      }

      /* fill in the option. */
      optbuf[2] = IP6OPT_JUMBO;
      optbuf[3] = 4;
      v = (u_int32_t)htonl(plen + JUMBOOPTLEN);
      bcopy(&v, &optbuf[4], sizeof(u_int32_t));

      /* finally, adjust the packet header length */
      exthdrs->ip6e_ip6->m_pkthdr.len += JUMBOOPTLEN;

      return(0);
#undef JUMBOOPTLEN
}

/*
 * Insert fragment header and copy unfragmentable header portions.
 */
static int
ip6_insertfraghdr(m0, m, hlen, frghdrp)
      struct mbuf *m0, *m;
      int hlen;
      struct ip6_frag **frghdrp;
{
      struct mbuf *n, *mlast;

      if (hlen > sizeof(struct ip6_hdr)) {
            n = m_copym(m0, sizeof(struct ip6_hdr),
                      hlen - sizeof(struct ip6_hdr), M_DONTWAIT);
            if (n == 0)
                  return(ENOBUFS);
            m->m_next = n;
      } else
            n = m;

      /* Search for the last mbuf of unfragmentable part. */
      for (mlast = n; mlast->m_next; mlast = mlast->m_next)
            ;

      if ((mlast->m_flags & M_EXT) == 0 &&
          M_TRAILINGSPACE(mlast) >= sizeof(struct ip6_frag)) {
            /* use the trailing space of the last mbuf for the fragment hdr */
            *frghdrp =
                  (struct ip6_frag *)(mtod(mlast, caddr_t) + mlast->m_len);
            mlast->m_len += sizeof(struct ip6_frag);
            m->m_pkthdr.len += sizeof(struct ip6_frag);
      } else {
            /* allocate a new mbuf for the fragment header */
            struct mbuf *mfrg;

            MGET(mfrg, M_DONTWAIT, MT_DATA);
            if (mfrg == 0)
                  return(ENOBUFS);
            mfrg->m_len = sizeof(struct ip6_frag);
            *frghdrp = mtod(mfrg, struct ip6_frag *);
            mlast->m_next = mfrg;
      }

      return(0);
}

static int
ip6_getpmtu(ro_pmtu, ro, ifp, dst, mtup)
#ifdef NEW_STRUCT_ROUTE
      struct route *ro_pmtu, *ro;
#else
      struct route_in6 *ro_pmtu, *ro;
#endif
      struct ifnet *ifp;
      struct in6_addr *dst;   /* XXX: should be sockaddr_in6 */
      u_long *mtup;
{
      u_int32_t mtu = 0;
      int error = 0;

      if (ro_pmtu != ro) {
            /* The first hop and the final destination may differ. */
            struct sockaddr_in6 *sa6_dst =
                  (struct sockaddr_in6 *)&ro_pmtu->ro_dst;
            if (ro_pmtu->ro_rt && ((ro_pmtu->ro_rt->rt_flags & RTF_UP)
                               == 0 ||
                               !IN6_ARE_ADDR_EQUAL(&sa6_dst->sin6_addr,
                                             dst))) {
                  RTFREE(ro_pmtu->ro_rt);
                  ro_pmtu->ro_rt = (struct rtentry *)NULL;
            }
            if (ro_pmtu->ro_rt == NULL) {
                  bzero(sa6_dst, sizeof(*sa6_dst));
                  sa6_dst->sin6_family = AF_INET6;
                  sa6_dst->sin6_len = sizeof(struct sockaddr_in6);
                  sa6_dst->sin6_addr = *dst;

#ifdef __bsdi__               /* bsdi needs rtcalloc to clone a route. */
                  rtcalloc((struct route *)ro_pmtu);
#else
                  rtalloc((struct route *)ro_pmtu);
#endif
            }
      }
      if (ro_pmtu->ro_rt) {
            u_int32_t ifmtu;

            if (ifp == NULL)
                  ifp = ro_pmtu->ro_rt->rt_ifp;
            ifmtu = nd_ifinfo[ifp->if_index].linkmtu;
            mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
            if (mtu > ifmtu || mtu == 0) {
                  /*
                   * The MTU on the route is larger than the MTU on
                   * the interface!  This shouldn't happen, unless the
                   * MTU of the interface has been changed after the
                   * interface was brought up.  Change the MTU in the
                   * route to match the interface MTU (as long as the
                   * field isn't locked).
                   *
                   * if MTU on the route is 0, we need to fix the MTU.
                   * this case happens with path MTU discovery timeouts.
                   */
                   mtu = ifmtu;
                   if ((ro_pmtu->ro_rt->rt_rmx.rmx_locks & RTV_MTU) == 0)
                         ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu; /* XXX */
            }
      } else if (ifp) {
            mtu = nd_ifinfo[ifp->if_index].linkmtu;
      } else
            error = EHOSTUNREACH; /* XXX */

      *mtup = mtu;
      return(error);
}

/*
 * IP6 socket option processing.
 */
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
int
ip6_ctloutput(so, sopt)
      struct socket *so;
      struct sockopt *sopt;
#else
int
ip6_ctloutput(op, so, level, optname, mp)
      int op;
      struct socket *so;
      int level, optname;
      struct mbuf **mp;
#endif
{
      int privileged, optdatalen;
      void *optdata;
      struct ip6_recvpktopts *rcvopts;
#if defined(IPSEC) && defined(__OpenBSD__)
      struct proc *p = curproc; /* XXX */
      struct tdb *tdb;
      struct tdb_ident *tdbip, tdbi;
      int s;
#endif
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
      struct inpcb *in6p = sotoinpcb(so);
      int error, optval;
      int level, op, optname;
      int optlen;
      struct proc *p;

      if (!sopt) {
            panic("ip6_ctloutput: arg soopt is NULL");
      }
        level = sopt->sopt_level;
        op = sopt->sopt_dir;
        optname = sopt->sopt_name;
        optlen = sopt->sopt_valsize;
        p = sopt->sopt_p;
#else
#ifdef HAVE_NRL_INPCB
      struct inpcb *inp = sotoinpcb(so);
#define in6p inp
#else  /* !NRL */
      struct in6pcb *in6p = sotoin6pcb(so);
#endif /* HAVE_NRL_INPCB */
      struct mbuf *m = *mp;
      int error, optval;
      int optlen;
#if defined(__NetBSD__) || (defined(__FreeBSD__) && __FreeBSD__ >= 3)
      struct proc *p = curproc;     /* XXX */
#endif

      optlen = m ? m->m_len : 0;
#endif /* FreeBSD >= 3 */
      error = optval = 0;
        privileged = 1;

      rcvopts = in6p->in6p_inputopts;

      if (level == IPPROTO_IPV6) {
            switch (op) {

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
            case SOPT_SET:
#else
            case PRCO_SETOPT:
#endif
                  switch (optname) {
                  case IPV6_2292PKTOPTIONS:
#ifdef IPV6_PKTOPTIONS
                  case IPV6_PKTOPTIONS:
#endif
                  {
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        struct mbuf *m;

                        error = soopt_getm(sopt, &m); /* XXX */
                        if (error)
                              break;
                        error = soopt_mcopyin(sopt, m); /* XXX */
                        if (error)
                              break;
                        error = ip6_pcbopts(&in6p->in6p_outputopts,
                                        m, so, sopt);
                        m_freem(m); /* XXX */
#else
                        error = ip6_pcbopts(&in6p->in6p_outputopts,
                                        m, so);
#endif /* FreeBSD >= 3 */
                        break;
                  }

                  /*
                   * Use of some Hop-by-Hop options or some
                   * Destination options, might require special
                   * privilege.  That is, normal applications
                   * (without special privilege) might be forbidden
                   * from setting certain options in outgoing packets,
                   * and might never see certain options in received
                   * packets. [RFC 2292 Section 6]
                   * KAME specific note:
                   *  KAME prevents non-privileged users from sending or
                   *  receiving ANY hbh/dst options in order to avoid
                   *  overhead of parsing options in the kernel.
                   */
                  case IPV6_RECVHOPOPTS:
                  case IPV6_RECVDSTOPTS:
                  case IPV6_RECVRTHDRDSTOPTS:
                        /* fall through */
                  case IPV6_UNICAST_HOPS:
                  case IPV6_HOPLIMIT:
                  case IPV6_FAITH:

                  case IPV6_RECVPKTINFO:
                  case IPV6_RECVHOPLIMIT:
                  case IPV6_RECVRTHDR:
                  case IPV6_RECVPATHMTU:
                  case IPV6_RECVTCLASS:
                  case IPV6_V6ONLY:
                  case IPV6_AUTOFLOWLABEL:
                        if (optlen != sizeof(int)) {
                              error = EINVAL;
                              break;
                        }
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyin(sopt, &optval,
                              sizeof optval, sizeof optval);
                        if (error)
                              break;
#else
                        optval = *mtod(m, int *);
#endif
                        switch (optname) {

                        case IPV6_UNICAST_HOPS:
                              if (optval < -1 || optval >= 256)
                                    error = EINVAL;
                              else {
                                    /* -1 = kernel default */
                                    in6p->in6p_hops = optval;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                                    if ((in6p->in6p_vflag &
                                         INP_IPV4) != 0)
                                          in6p->inp_ip_ttl = optval;
#endif
                              }
                              break;
#define OPTSET(bit) \
do { \
      if (optval) \
            in6p->in6p_flags |= (bit); \
      else \
            in6p->in6p_flags &= ~(bit); \
} while (0)
#define OPTSET2292(bit) \
do { \
      in6p->in6p_flags |= IN6P_RFC2292; \
      if (optval) \
            in6p->in6p_flags |= (bit); \
      else \
            in6p->in6p_flags &= ~(bit); \
} while (0)
#define OPTBIT(bit) (in6p->in6p_flags & (bit) ? 1 : 0)

                        case IPV6_RECVPKTINFO:
                              /* cannot mix with RFC2292 */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              OPTSET(IN6P_PKTINFO);
                              if (OPTBIT(IN6P_PKTINFO) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVPKTINFO);
                              break;

                        case IPV6_HOPLIMIT:
                        {
                              struct ip6_pktopts **optp;

                              /* cannot mix with RFC2292 */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              optp = &in6p->in6p_outputopts;
                              error = ip6_pcbopt(IPV6_HOPLIMIT,
                                             (u_char *)&optval,
                                             sizeof(optval),
                                             optp,
                                             privileged);
                              break;
                        }

                        case IPV6_RECVHOPLIMIT:
                              /* cannot mix with RFC2292 */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              OPTSET(IN6P_HOPLIMIT);
                              if (OPTBIT(IN6P_HOPLIMIT) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVHOPLIMIT);
                              break;

                        case IPV6_RECVHOPOPTS:
                              /* cannot mix with RFC2292 */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              OPTSET(IN6P_HOPOPTS);
                              if (OPTBIT(IN6P_HOPOPTS) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVHOPOPTS);
                              break;

                        case IPV6_RECVDSTOPTS:
                              /* cannot mix with RFC2292 */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              OPTSET(IN6P_DSTOPTS);
                              if (OPTBIT(IN6P_DSTOPTS) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVDSTOPTS);
                              break;

                        case IPV6_RECVRTHDRDSTOPTS:
                              /* cannot mix with RFC2292 */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              OPTSET(IN6P_RTHDRDSTOPTS);
                              if (OPTBIT(IN6P_RTHDRDSTOPTS) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVRTHDRDSTOPTS);
                              break;

                        case IPV6_RECVRTHDR:
                              /* cannot mix with RFC2292 */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              OPTSET(IN6P_RTHDR);
                              if (OPTBIT(IN6P_RTHDR) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVRTHDR);
                              break;

                        case IPV6_FAITH:
                              OPTSET(IN6P_FAITH);
                              break;

                        case IPV6_RECVPATHMTU:
                              OPTSET(IN6P_MTU);
                              break;

                        case IPV6_V6ONLY:
                              /*
                               * make setsockopt(IPV6_V6ONLY)
                               * available only prior to bind(2).
                               * see ipng mailing list, Jun 22 2001.
                               */
                              if (in6p->in6p_lport ||
                                  !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr))
                              {
                                    error = EINVAL;
                                    break;
                              }
#ifdef __NetBSD__
#ifdef INET6_BINDV6ONLY
                              if (!optval)
                                    error = EINVAL;
#else
                              OPTSET(IN6P_IPV6_V6ONLY);
#endif
#elif (defined(__FreeBSD__) && __FreeBSD__ >= 3) || (defined(__bsdi__) && _BSDI_VERSION >= 199802)
                              OPTSET(IN6P_IPV6_V6ONLY);
#else
                              if ((ip6_v6only && optval) ||
                                  (!ip6_v6only && !optval))
                                    error = 0;
                              else
                                    error = EINVAL;
#endif
                              break;
                        case IPV6_RECVTCLASS:
                              /* cannot mix with RFC2292 XXX */
                              if (OPTBIT(IN6P_RFC2292)) {
                                    error = EINVAL;
                                    break;
                              }
                              OPTSET(IN6P_TCLASS);
                              break;
                        case IPV6_AUTOFLOWLABEL:
                              OPTSET(IN6P_AUTOFLOWLABEL);
                              break;

                        }
                        break;

                  case IPV6_OTCLASS:
                  {
                        struct ip6_pktopts **optp;
                        u_int8_t tclass;

                        if (optlen != sizeof(tclass)) {
                              error = EINVAL;
                              break;
                        }
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyin(sopt, &tclass,
                              sizeof tclass, sizeof tclass);
                        if (error)
                              break;
#else
                        tclass = *mtod(m, u_int8_t *);
#endif
                        optp = &in6p->in6p_outputopts;
                        error = ip6_pcbopt(optname,
                                       (u_char *)&tclass,
                                       sizeof(tclass),
                                       optp,
                                       privileged);
                        break;
                  }

                  case IPV6_TCLASS:
                  case IPV6_DONTFRAG:
                  case IPV6_USE_MIN_MTU:
                        if (optlen != sizeof(optval)) {
                              error = EINVAL;
                              break;
                        }
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyin(sopt, &optval,
                              sizeof optval, sizeof optval);
                        if (error)
                              break;
#else
                        optval = *mtod(m, int *);
#endif
                        {
                              struct ip6_pktopts **optp;
                              optp = &in6p->in6p_outputopts;
                              error = ip6_pcbopt(optname,
                                             (u_char *)&optval,
                                             sizeof(optval),
                                             optp,
                                             privileged);
                              break;
                        }

                  case IPV6_2292PKTINFO:
                  case IPV6_2292HOPLIMIT:
                  case IPV6_2292HOPOPTS:
                  case IPV6_2292DSTOPTS:
                  case IPV6_2292RTHDR:
                        /* RFC 2292 */
                        if (optlen != sizeof(int)) {
                              error = EINVAL;
                              break;
                        }
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyin(sopt, &optval,
                              sizeof optval, sizeof optval);
                        if (error)
                              break;
#else
                        optval = *mtod(m, int *);
#endif
                        switch (optname) {
                        case IPV6_2292PKTINFO:
                              OPTSET2292(IN6P_PKTINFO);
                              if (OPTBIT(IN6P_PKTINFO) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVPKTINFO);
                              break;
                        case IPV6_2292HOPLIMIT:
                              OPTSET2292(IN6P_HOPLIMIT);
                              if (OPTBIT(IN6P_HOPLIMIT) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVHOPLIMIT);
                              break;
                        case IPV6_2292HOPOPTS:
                              /*
                               * Check super-user privilege.
                               * See comments for IPV6_RECVHOPOPTS.
                               */
                              OPTSET2292(IN6P_HOPOPTS);
                              if (OPTBIT(IN6P_HOPOPTS) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVHOPOPTS);
                              break;
                        case IPV6_2292DSTOPTS:
                              OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
                              if (OPTBIT(IN6P_DSTOPTS) == 0) {
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVDSTOPTS);
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVRTHDRDSTOPTS);
                              }
                              break;
                        case IPV6_2292RTHDR:
                              OPTSET2292(IN6P_RTHDR);
                              if (OPTBIT(IN6P_RTHDR) == 0)
                                    ip6_reset_rcvopt(rcvopts, IPV6_RECVRTHDR);
                              break;
                        }
                        break;
                  case IPV6_PKTINFO:
                  case IPV6_HOPOPTS:
                  case IPV6_RTHDR:
                  case IPV6_DSTOPTS:
                  case IPV6_RTHDRDSTOPTS:
                  case IPV6_NEXTHOP:
                  {
                        /* new advanced API (2292bis) */
                        u_char *optbuf;
                        int optlen;
                        struct ip6_pktopts **optp;

                        /* cannot mix with RFC2292 */
                        if (OPTBIT(IN6P_RFC2292)) {
                              error = EINVAL;
                              break;
                        }

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        optbuf = sopt->sopt_val;
                        optlen = sopt->sopt_valsize;
#else  /* !fbsd3 */
                        if (m && m->m_next) {
                              error = EINVAL;   /* XXX */
                              break;
                        }
                        if (m) {
                              optbuf = mtod(m, u_char *);
                              optlen = m->m_len;
                        } else {
                              optbuf = NULL;
                              optlen = 0;
                        }
#endif
                        optp = &in6p->in6p_outputopts;
                        error = ip6_pcbopt(optname,
                                       optbuf, optlen,
                                       optp, privileged);
                        break;
                  }
#undef OPTSET

                  case IPV6_MULTICAST_IF:
                  case IPV6_MULTICAST_HOPS:
                  case IPV6_MULTICAST_LOOP:
                  case IPV6_JOIN_GROUP:
                  case IPV6_LEAVE_GROUP:
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                      {
                        struct mbuf *m;
                        if (sopt->sopt_valsize > MLEN) {
                              error = EMSGSIZE;
                              break;
                        }
                        /* XXX */
                        MGET(m, sopt->sopt_p ? M_WAIT : M_DONTWAIT, MT_HEADER);
                        if (m == 0) {
                              error = ENOBUFS;
                              break;
                        }
                        m->m_len = sopt->sopt_valsize;
                        error = sooptcopyin(sopt, mtod(m, char *),
                                        m->m_len, m->m_len);
                        error =     ip6_setmoptions(sopt->sopt_name,
                                          &in6p->in6p_moptions,
                                          m);
                        (void)m_free(m);
                      }
#else
                        error =     ip6_setmoptions(optname,
                                          &in6p->in6p_moptions,
                                          m);
#if defined(__bsdi__) && _BSDI_VERSION >= 199802
                        if (in6p->in6p_moptions != NULL)
                              in6p->in6p_flags |= INP_IPV6_MCAST; /* XXX */
#endif
#endif
                        break;

#ifndef __bsdi__
                  case IPV6_PORTRANGE:
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyin(sopt, &optval,
                            sizeof optval, sizeof optval);
                        if (error)
                              break;
#else
                        optval = *mtod(m, int *);
#endif

                        switch (optval) {
                        case IPV6_PORTRANGE_DEFAULT:
                              in6p->in6p_flags &= ~(IN6P_LOWPORT);
                              in6p->in6p_flags &= ~(IN6P_HIGHPORT);
                              break;

                        case IPV6_PORTRANGE_HIGH:
                              in6p->in6p_flags &= ~(IN6P_LOWPORT);
                              in6p->in6p_flags |= IN6P_HIGHPORT;
                              break;

                        case IPV6_PORTRANGE_LOW:
                              in6p->in6p_flags &= ~(IN6P_HIGHPORT);
                              in6p->in6p_flags |= IN6P_LOWPORT;
                              break;

                        default:
                              error = EINVAL;
                              break;
                        }
                        break;
#endif

#ifdef __OpenBSD__
                  case IPSEC6_OUTSA:
#ifndef IPSEC
                        error = EINVAL;
#else
                        s = spltdb();
                        if (m == 0 || m->m_len != sizeof(struct tdb_ident)) {
                              error = EINVAL;
                        } else {
                              tdbip = mtod(m, struct tdb_ident *);
                              tdb = gettdb(tdbip->spi, &tdbip->dst,
                                  tdbip->proto);
                              if (tdb == NULL)
                                    error = ESRCH;
                              else
                                    tdb_add_inp(tdb, inp, 0);
                        }
                        splx(s);
#endif
                        break;

                  case IPV6_AUTH_LEVEL:
                  case IPV6_ESP_TRANS_LEVEL:
                  case IPV6_ESP_NETWORK_LEVEL:
                  case IPV6_IPCOMP_LEVEL:
#ifndef IPSEC
                        error = EINVAL;
#else
                        if (m == 0 || m->m_len != sizeof(int)) {
                              error = EINVAL;
                              break;
                        }
                        optval = *mtod(m, int *);

                        if (optval < IPSEC_LEVEL_BYPASS || 
                            optval > IPSEC_LEVEL_UNIQUE) {
                              error = EINVAL;
                              break;
                        }
                              
                        switch (optname) {
                        case IPV6_AUTH_LEVEL:
                              inp->inp_seclevel[SL_AUTH] = optval;
                              break;

                        case IPV6_ESP_TRANS_LEVEL:
                              inp->inp_seclevel[SL_ESP_TRANS] = optval;
                              break;

                        case IPV6_ESP_NETWORK_LEVEL:
                              inp->inp_seclevel[SL_ESP_NETWORK] = optval;
                              break;

                        case IPV6_IPCOMP_LEVEL:
                              inp->inp_seclevel[SL_IPCOMP] = optval;
                              break;
                        }
                        if (!error)
                              inp->inp_secrequire = get_sa_require(inp);
#endif
                        break;
#endif /* OpenBSD */

#if defined(IPSEC) && !defined(__OpenBSD__)
                  case IPV6_IPSEC_POLICY:
                      {
                        caddr_t req = NULL;
                        size_t len = 0;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        struct mbuf *m;
#endif

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
                              break;
                        if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
                              break;
#endif
                        if (m) {
                              req = mtod(m, caddr_t);
                              len = m->m_len;
                        }
                        error = ipsec6_set_policy(in6p, optname, req,
                                            len, privileged);
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        m_freem(m);
#endif
                      }
                        break;
#endif /* KAME IPSEC */

#if defined(IPV6FIREWALL) || (defined(__FreeBSD__) && __FreeBSD__ >= 4)
                  case IPV6_FW_ADD:
                  case IPV6_FW_DEL:
                  case IPV6_FW_FLUSH:
                  case IPV6_FW_ZERO:
                      {
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        struct mbuf *m;
                        struct mbuf **mp = &m;
#endif

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        if (ip6_fw_ctl_ptr == NULL)
                              return EINVAL;
                        /* XXX */
                        if ((error = soopt_getm(sopt, &m)) != 0)
                              break;
                        /* XXX */
                        if ((error = soopt_mcopyin(sopt, m)) != 0)
                              break;
#else
                        if (ip6_fw_ctl_ptr == NULL) {
                              if (m) (void)m_free(m);
                              return EINVAL;
                        }
#endif
                        error = (*ip6_fw_ctl_ptr)(optname, mp);
                        m = *mp;
                      }
                        break;
#endif

                  default:
                        error = ENOPROTOOPT;
                        break;
                  }
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
                  if (m)
                        (void)m_free(m);
#endif
                  break;

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
            case SOPT_GET:
#else
            case PRCO_GETOPT:
#endif
                  switch (optname) {

                  case IPV6_2292PKTOPTIONS:
#ifdef IPV6_PKTOPTIONS
                  case IPV6_PKTOPTIONS:
#endif
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        if (in6p->in6p_inputopts &&
                            in6p->in6p_inputopts->head) {
                              struct mbuf *m;
                              m = m_copym(in6p->in6p_inputopts->head,
                                  0, M_COPYALL, M_WAIT);
                              error = soopt_mcopyout(sopt, m);
                              if (error == 0)
                                    m_freem(m);
                        } else
                              sopt->sopt_valsize = 0;
#else
                        if (in6p->in6p_inputopts &&
                            in6p->in6p_inputopts->head) {
                              *mp = m_copym(in6p->in6p_inputopts->head,
                                          0, M_COPYALL, M_WAIT);
                        } else {
                              *mp = m_get(M_WAIT, MT_SOOPTS);
                              (*mp)->m_len = 0;
                        }
#endif
                        break;

                  case IPV6_RECVHOPOPTS:
                  case IPV6_RECVDSTOPTS:
                  case IPV6_RECVRTHDRDSTOPTS:
                  case IPV6_UNICAST_HOPS:
                  case IPV6_RECVPKTINFO:
                  case IPV6_RECVHOPLIMIT:
                  case IPV6_RECVRTHDR:
                  case IPV6_USE_MIN_MTU:
                  case IPV6_RECVPATHMTU:
                  case IPV6_DONTFRAG:

                  case IPV6_FAITH:
                  case IPV6_V6ONLY:
#ifndef __bsdi__
                  case IPV6_PORTRANGE:
#endif
                  case IPV6_RECVTCLASS:
                  case IPV6_AUTOFLOWLABEL:
                        switch (optname) {

                        case IPV6_UNICAST_HOPS:
                              optval = in6p->in6p_hops;
                              break;

                        case IPV6_RECVPKTINFO:
                              optval = OPTBIT(IN6P_PKTINFO);
                              break;

                        case IPV6_RECVHOPLIMIT:
                              optval = OPTBIT(IN6P_HOPLIMIT);
                              break;

                        case IPV6_RECVHOPOPTS:
                              optval = OPTBIT(IN6P_HOPOPTS);
                              break;

                        case IPV6_RECVDSTOPTS:
                              optval = OPTBIT(IN6P_DSTOPTS);
                              break;

                        case IPV6_RECVRTHDRDSTOPTS:
                              optval = OPTBIT(IN6P_RTHDRDSTOPTS);
                              break;

                        case IPV6_RECVPATHMTU:
                              optval = OPTBIT(IN6P_MTU);
                              break;

                        case IPV6_FAITH:
                              optval = OPTBIT(IN6P_FAITH);
                              break;

                        case IPV6_V6ONLY:
#if (defined(__FreeBSD__) && __FreeBSD__ >= 3) || defined(__NetBSD__) || (defined(__bsdi__) && _BSDI_VERSION >= 199802) 
                              optval = OPTBIT(IN6P_IPV6_V6ONLY);
#else
                              optval = (ip6_v6only != 0); /* XXX */
#endif
                              break;

#ifndef __bsdi__
                        case IPV6_PORTRANGE:
                            {
                              int flags;
                              flags = in6p->in6p_flags;
                              if (flags & IN6P_HIGHPORT)
                                    optval = IPV6_PORTRANGE_HIGH;
                              else if (flags & IN6P_LOWPORT)
                                    optval = IPV6_PORTRANGE_LOW;
                              else
                                    optval = 0;
                              break;
                            }
#endif
                        case IPV6_RECVTCLASS:
                              optval = OPTBIT(IN6P_TCLASS);
                              break;

                        case IPV6_AUTOFLOWLABEL:
                              optval = OPTBIT(IN6P_AUTOFLOWLABEL);
                              break;

#define PKTOPTBIT(bit) ((in6p->in6p_outputopts && \
                     (in6p->in6p_outputopts->ip6po_flags & (bit))) ? 1 : 0)
                        case IPV6_DONTFRAG:
                              optval = PKTOPTBIT(IP6PO_DONTFRAG);
                              break;

                        case IPV6_USE_MIN_MTU:
                              optval = PKTOPTBIT(IP6PO_MINMTU);
                              break;
#undef PKTOPTBIT
                        }
                        if (error)
                              break;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyout(sopt, &optval,
                              sizeof optval);
#else
                        *mp = m = m_get(M_WAIT, MT_SOOPTS);
                        m->m_len = sizeof(int);
                        *mtod(m, int *) = optval;
#endif
                        break;

                  case IPV6_PATHMTU:
                  {
                        u_long pmtu = 0;
                        struct ip6_mtuinfo mtuinfo;
#ifdef NEW_STRUCT_ROUTE
                        struct route *ro = &in6p->in6p_route;
#else
                        struct route_in6 *ro = (struct route_in6 *)&in6p->in6p_route;
#endif

                        if (!(so->so_state & SS_ISCONNECTED))
                              return(ENOTCONN);
                        /*
                         * XXX: we dot not consider the case of source
                         * routing, nor optional information to specify
                         * the outgoing interface.
                         */
                        error = ip6_getpmtu(ro, NULL, NULL,
                                        &in6p->in6p_faddr, &pmtu);
                        if (error)
                              break;
                        if (pmtu > IPV6_MAXPACKET)
                              pmtu = IPV6_MAXPACKET;

                        bzero(&mtuinfo, sizeof(mtuinfo));
                        mtuinfo.ip6m_mtu = (u_int32_t)pmtu;
                        optdata = (void *)&mtuinfo;
                        optdatalen = sizeof(mtuinfo);
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyout(sopt, optdata,
                                         optdatalen);
#else  /* !FreeBSD3 */
                              if (optdatalen > MCLBYTES)
                                    return(EMSGSIZE); /* XXX */
                              *mp = m = m_get(M_WAIT, MT_SOOPTS);
                              if (optdatalen > MLEN)
                                    MCLGET(m, M_WAIT);
                              m->m_len = optdatalen;
                              bcopy(optdata, mtod(m, void *),
                                    optdatalen);
#endif /* FreeBSD3 */
                        break;
                  }

                  case IPV6_2292PKTINFO:
                  case IPV6_2292HOPLIMIT:
                  case IPV6_2292HOPOPTS:
                  case IPV6_2292RTHDR:
                  case IPV6_2292DSTOPTS:
                        if (optname == IPV6_2292HOPOPTS ||
                            optname == IPV6_2292DSTOPTS ||
                            !privileged)
                              return(EPERM);
                        switch (optname) {
                        case IPV6_2292PKTINFO:
                              optval = OPTBIT(IN6P_PKTINFO);
                              break;
                        case IPV6_2292HOPLIMIT:
                              optval = OPTBIT(IN6P_HOPLIMIT);
                              break;
                        case IPV6_2292HOPOPTS:
                              optval = OPTBIT(IN6P_HOPOPTS);
                              break;
                        case IPV6_2292RTHDR:
                              optval = OPTBIT(IN6P_RTHDR);
                              break;
                        case IPV6_2292DSTOPTS:
                              optval = OPTBIT(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS);
                              break;
                        }
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = sooptcopyout(sopt, &optval,
                              sizeof optval);
#else
                        *mp = m = m_get(M_WAIT, MT_SOOPTS);
                        m->m_len = sizeof(int);
                        *mtod(m, int *) = optval;
#endif /* FreeBSD3 */
                        break;
                  case IPV6_PKTINFO:
                  case IPV6_HOPOPTS:
                  case IPV6_RTHDR:
                  case IPV6_DSTOPTS:
                  case IPV6_RTHDRDSTOPTS:
                  case IPV6_NEXTHOP:
                  case IPV6_OTCLASS:
                  case IPV6_TCLASS:
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        error = ip6_getpcbopt(in6p->in6p_outputopts,
                                          optname, sopt);
#else
                        error = ip6_getpcbopt(in6p->in6p_outputopts,
                                          optname, mp);
#endif
                        break;

                  case IPV6_MULTICAST_IF:
                  case IPV6_MULTICAST_HOPS:
                  case IPV6_MULTICAST_LOOP:
                  case IPV6_JOIN_GROUP:
                  case IPV6_LEAVE_GROUP:
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                      {
                        struct mbuf *m;
                        error = ip6_getmoptions(sopt->sopt_name,
                                    in6p->in6p_moptions, &m);
                        if (error == 0)
                              error = sooptcopyout(sopt,
                                    mtod(m, char *), m->m_len);
                        m_freem(m);
                      }
#else
                        error = ip6_getmoptions(optname, in6p->in6p_moptions, mp);
#endif
                        break;

#ifdef __OpenBSD__
                  case IPSEC6_OUTSA:
#ifndef IPSEC
                        error = EINVAL;
#else
                        s = spltdb();
                        if (inp->inp_tdb_out == NULL) {
                              error = ENOENT;
                        } else {
                              tdbi.spi = inp->inp_tdb_out->tdb_spi;
                              tdbi.dst = inp->inp_tdb_out->tdb_dst;
                              tdbi.proto = inp->inp_tdb_out->tdb_sproto;
                              *mp = m = m_get(M_WAIT, MT_SOOPTS);
                              m->m_len = sizeof(tdbi);
                              bcopy((caddr_t)&tdbi, mtod(m, caddr_t),
                                  (unsigned)m->m_len);
                        }
                        splx(s);
#endif
                        break;

                  case IPV6_AUTH_LEVEL:
                  case IPV6_ESP_TRANS_LEVEL:
                  case IPV6_ESP_NETWORK_LEVEL:
                  case IPV6_IPCOMP_LEVEL:
#ifndef IPSEC
                        m->m_len = sizeof(int);
                        *mtod(m, int *) = IPSEC_LEVEL_NONE;
#else
                        m->m_len = sizeof(int);
                        switch (optname) {
                        case IPV6_AUTH_LEVEL:
                              optval = inp->inp_seclevel[SL_AUTH];
                              break;

                        case IPV6_ESP_TRANS_LEVEL:
                              optval =
                                  inp->inp_seclevel[SL_ESP_TRANS];
                              break;

                        case IPV6_ESP_NETWORK_LEVEL:
                              optval =
                                  inp->inp_seclevel[SL_ESP_NETWORK];
                              break;

                        case IPV6_IPCOMP_LEVEL:
                              optval = inp->inp_seclevel[SL_IPCOMP];
                              break;
                        }
                        *mtod(m, int *) = optval;
#endif
                        break;
#endif /* OpenBSD */

#if defined(IPSEC) && !defined(__OpenBSD__)
                  case IPV6_IPSEC_POLICY:
                    {
                        caddr_t req = NULL;
                        size_t len = 0;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        struct mbuf *m = NULL;
                        struct mbuf **mp = &m;

                        error = soopt_getm(sopt, &m); /* XXX */
                        if (error != NULL)
                              break;
                        error = soopt_mcopyin(sopt, m); /* XXX */
                        if (error != NULL)
                              break;
#endif
                        if (m) {
                              req = mtod(m, caddr_t);
                              len = m->m_len;
                        }
                        error = ipsec6_get_policy(in6p, req, len, mp);
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        if (error == 0)
                              error = soopt_mcopyout(sopt, m); /* XXX */
                        if (error == 0 && m)
                              m_freem(m);
#endif
                        break;
                    }
#endif /* KAME IPSEC */

#if defined(IPV6FIREWALL) || (defined(__FreeBSD__) && __FreeBSD__ >= 4)
                  case IPV6_FW_GET:
                    {
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        struct mbuf *m;
                        struct mbuf **mp = &m;
#endif

                        if (ip6_fw_ctl_ptr == NULL)
                          {
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
                              if (m)
                                    (void)m_free(m);
#endif
                              return EINVAL;
                        }
                        error = (*ip6_fw_ctl_ptr)(optname, mp);
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                        if (error == 0)
                              error = soopt_mcopyout(sopt, m); /* XXX */
                        if (error == 0 && m)
                              m_freem(m);
#endif
                    }
                        break;
#endif

                  default:
                        error = ENOPROTOOPT;
                        break;
                  }
                  break;
            }
      } else {          /* level != IPPROTO_IPV6 */
            error = EINVAL;
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
            if (op == PRCO_SETOPT && *mp)
                  (void)m_free(*mp);
#endif
      }
      return(error);
}

#ifndef offsetof
#define     offsetof(type, member)  ((size_t)(&((type *)0)->member)) /* XXX */
#endif
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
int
ip6_raw_ctloutput(so, sopt)
      struct socket *so;
      struct sockopt *sopt;
#else
int
ip6_raw_ctloutput(op, so, level, optname, mp)
      int op;
      struct socket *so;
      int level, optname;
      struct mbuf **mp;
#endif
{
      int error = 0, optval, optlen;
      const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
#ifdef HAVE_NRL_INPCB
      struct inpcb *inp = sotoinpcb(so);
#else
      struct in6pcb *in6p = sotoin6pcb(so);
#endif
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
      int level, op, optname;
      struct proc *p;
#else
      struct mbuf *m = *mp;
#endif /* FreeBSD >= 3 */

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
      if (!sopt) {
            panic("ip6_ctloutput: arg soopt is NULL");
      }
        level = sopt->sopt_level;
        op = sopt->sopt_dir;
        optname = sopt->sopt_name;
        optlen = sopt->sopt_valsize;
        p = sopt->sopt_p;
#else
      optlen = m ? m->m_len : 0;
#endif /* FreeBSD >= 3 */

      if (level != IPPROTO_IPV6) {
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
            if (op == PRCO_SETOPT && *mp)
                  (void)m_free(*mp);
#endif
            return(EINVAL);
      }
            
      switch (optname) {
      case IPV6_CHECKSUM:
            /*
             * For ICMPv6 sockets, no modification allowed for checksum
             * offset, permit "no change" values to help existing apps.
             *
             * XXX 2292bis says: "An attempt to set IPV6_CHECKSUM
             * for an ICMPv6 socket will fail."
             * The current behavior does not meet 2292bis.
             */
            switch (op) {
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
            case SOPT_SET:
#else
            case PRCO_SETOPT:
#endif
                  if (optlen != sizeof(int)) {
                        error = EINVAL;
                        break;
                  }
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                  error = sooptcopyin(sopt, &optval, sizeof(optval),
                                  sizeof(optval));
                  if (error)
                        break;
#else
                  optval = *mtod(m, int *);
#endif
                  if ((optval % 2) != 0) {
                        /* the API assumes even offset values */
                        error = EINVAL;
                  } else if (so->so_proto->pr_protocol ==
                           IPPROTO_ICMPV6) {
                        if (optval != icmp6off)
                              error = EINVAL;
                  } else
                        in6p->in6p_cksum = optval;
                  break;

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
            case SOPT_GET:
#else
            case PRCO_GETOPT:
#endif
                  if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
                        optval = icmp6off;
                  else
                        optval = in6p->in6p_cksum;

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
                  error = sooptcopyout(sopt, &optval, sizeof(optval));
#else
                  *mp = m = m_get(M_WAIT, MT_SOOPTS);
                  m->m_len = sizeof(int);
                  *mtod(m, int *) = optval;
#endif /* FreeBSD3 */
                  break;
            default:
                  error = EINVAL;
                  break;
            }

      default:
            error = ENOPROTOOPT;
            break;
      }

#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
      if (op == PRCO_SETOPT && m)
            (void)m_free(m);
#endif

      return(error);
}

#ifdef HAVE_NRL_INPCB
#undef in6p
#endif

/*
 * Set up IP6 options in pcb for insertion in output packets or
 * specifying behavior of outgoing packets.
 */
static int
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
ip6_pcbopts(pktopt, m, so, sopt)
#else
ip6_pcbopts(pktopt, m, so)
#endif
      struct ip6_pktopts **pktopt;
      struct mbuf *m;
      struct socket *so;
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
      struct sockopt *sopt;
#endif
{
      struct ip6_pktopts *opt = *pktopt;
      int error = 0;
      int priv = 1;

      /* turn off any old options. */
      if (opt) {
#ifdef DIAGNOSTIC
          if (opt->ip6po_pktinfo || opt->ip6po_nexthop ||
            opt->ip6po_hbh || opt->ip6po_dest1 || opt->ip6po_dest2 ||
            opt->ip6po_rhinfo.ip6po_rhi_rthdr)
                printf("ip6_pcbopts: all specified options are cleared.\n");
#endif
            ip6_clearpktopts(opt, -1);
      } else
            opt = malloc(sizeof(*opt), M_IP6OPT, M_WAITOK);
      *pktopt = NULL;

      if (!m || m->m_len == 0) {
            /*
             * Only turning off any previous options.
             */
            if (opt)
                  free(opt, M_IP6OPT);
            return(0);
      }

      if ((error = ip6_setpktoptions(m, opt, NULL, priv, 1)) != 0) {
            ip6_clearpktopts(opt, -1); /* XXX: discard all options */
            return(error);
      }
      *pktopt = opt;
      return(0);
}

/*
 * initialize ip6_pktopts.  beware that there are non-zero default values in
 * the struct.
 */
void
init_ip6pktopts(opt)
      struct ip6_pktopts *opt;
{

      bzero(opt, sizeof(*opt));
      opt->ip6po_hlim = -1;   /* -1 means default hop limit */
      opt->ip6po_tclass = -1; /* -1 means default traffic class */
}

#define sin6tosa(sin6)  ((struct sockaddr *)(sin6)) /* XXX */
static int
ip6_pcbopt(optname, buf, len, pktopt, priv)
      int optname, len, priv;
      u_char *buf;
      struct ip6_pktopts **pktopt;
{
      struct ip6_pktopts *opt;
      
      if (*pktopt == NULL) {
            *pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
                         M_WAITOK);
            init_ip6pktopts(*pktopt);
            (*pktopt)->needfree = 1;
      }
      opt = *pktopt;

      return(ip6_setpktoption(optname, buf, len, opt, priv, 1, 0));
}

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
static int
ip6_getpcbopt(pktopt, optname, sopt)
      struct ip6_pktopts *pktopt;
      struct sockopt *sopt;
      int optname;
#else
static int
ip6_getpcbopt(pktopt, optname, mp)
      struct ip6_pktopts *pktopt;
      int optname;
      struct mbuf **mp;
#endif
{
      void *optdata = NULL;
      int optdatalen = 0;
      struct ip6_ext *ip6e;
      int error = 0;
      struct in6_pktinfo null_pktinfo;
      int deftclass = 0;
#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
      struct mbuf *m;
#endif

      switch (optname) {
      case IPV6_PKTINFO:
            if (pktopt && pktopt->ip6po_pktinfo)
                  optdata = (void *)pktopt->ip6po_pktinfo;
            else {
                  /* XXX: we don't have to do this every time... */
                  bzero(&null_pktinfo, sizeof(null_pktinfo));
                  optdata = (void *)&null_pktinfo;
            }
            optdatalen = sizeof(struct in6_pktinfo);
            break;
      case IPV6_OTCLASS:
            /* XXX */
            return(EINVAL);
      case IPV6_TCLASS:
            if (pktopt && pktopt->ip6po_tclass >= 0)
                  optdata = (void *)&pktopt->ip6po_tclass;
            else
                  optdata = (void *)&deftclass;
            optdatalen = sizeof(int);
            break;
      case IPV6_HOPOPTS:
            if (pktopt && pktopt->ip6po_hbh) {
                  optdata = (void *)pktopt->ip6po_hbh;
                  ip6e = (struct ip6_ext *)pktopt->ip6po_hbh;
                  optdatalen = (ip6e->ip6e_len + 1) << 3;
            }
            break;
      case IPV6_RTHDR:
            if (pktopt && pktopt->ip6po_rthdr) {
                  optdata = (void *)pktopt->ip6po_rthdr;
                  ip6e = (struct ip6_ext *)pktopt->ip6po_rthdr;
                  optdatalen = (ip6e->ip6e_len + 1) << 3;
            }
            break;
      case IPV6_RTHDRDSTOPTS:
            if (pktopt && pktopt->ip6po_dest1) {
                  optdata = (void *)pktopt->ip6po_dest1;
                  ip6e = (struct ip6_ext *)pktopt->ip6po_dest1;
                  optdatalen = (ip6e->ip6e_len + 1) << 3;
            }
            break;
      case IPV6_DSTOPTS:
            if (pktopt && pktopt->ip6po_dest2) {
                  optdata = (void *)pktopt->ip6po_dest2;
                  ip6e = (struct ip6_ext *)pktopt->ip6po_dest2;
                  optdatalen = (ip6e->ip6e_len + 1) << 3;
            }
            break;
      case IPV6_NEXTHOP:
            if (pktopt && pktopt->ip6po_nexthop) {
                  optdata = (void *)pktopt->ip6po_nexthop;
                  optdatalen = pktopt->ip6po_nexthop->sa_len;
            }
            break;
      default:          /* should not happen */
            printf("ip6_getpcbopt: unexpected option: %d\n", optname);
            return(ENOPROTOOPT);
      }

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
      error = sooptcopyout(sopt, optdata, optdatalen);
#else  /* !FreeBSD3 */
      if (optdatalen > MCLBYTES)
            return(EMSGSIZE); /* XXX */
      *mp = m = m_get(M_WAIT, MT_SOOPTS);
      if (optdatalen > MLEN)
            MCLGET(m, M_WAIT);
      m->m_len = optdatalen;
      if (optdatalen)
            bcopy(optdata, mtod(m, void *), optdatalen);
#endif /* FreeBSD3 */

      return(error);
}

void
ip6_clearpktopts(pktopt, optname)
      struct ip6_pktopts *pktopt;
      int optname;
{
      int needfree = pktopt->needfree;

      if (pktopt == NULL)
            return;

      if (optname == -1 || optname == IPV6_PKTINFO) {
            if (needfree && pktopt->ip6po_pktinfo)
                  free(pktopt->ip6po_pktinfo, M_IP6OPT);
            pktopt->ip6po_pktinfo = NULL;
      }
      if (optname == -1 || optname == IPV6_HOPLIMIT)
            pktopt->ip6po_hlim = -1;
      if (optname == -1 || optname == IPV6_TCLASS)
            pktopt->ip6po_tclass = -1;
      if (optname == -1 || optname == IPV6_NEXTHOP) {
            if (pktopt->ip6po_nextroute.ro_rt) {
                  RTFREE(pktopt->ip6po_nextroute.ro_rt);
                  pktopt->ip6po_nextroute.ro_rt = NULL;
            }
            if (needfree && pktopt->ip6po_nexthop)
                  free(pktopt->ip6po_nexthop, M_IP6OPT);
            pktopt->ip6po_nexthop = NULL;
      }
      if (optname == -1 || optname == IPV6_HOPOPTS) {
            if (needfree && pktopt->ip6po_hbh)
                  free(pktopt->ip6po_hbh, M_IP6OPT);
            pktopt->ip6po_hbh = NULL;
      }
      if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
            if (needfree && pktopt->ip6po_dest1)
                  free(pktopt->ip6po_dest1, M_IP6OPT);
            pktopt->ip6po_dest1 = NULL;
      }
      if (optname == -1 || optname == IPV6_RTHDR) {
            if (needfree && pktopt->ip6po_rhinfo.ip6po_rhi_rthdr)
                  free(pktopt->ip6po_rhinfo.ip6po_rhi_rthdr, M_IP6OPT);
            pktopt->ip6po_rhinfo.ip6po_rhi_rthdr = NULL;
            if (pktopt->ip6po_route.ro_rt) {
                  RTFREE(pktopt->ip6po_route.ro_rt);
                  pktopt->ip6po_route.ro_rt = NULL;
            }
      }
      if (optname == -1 || optname == IPV6_DSTOPTS) {
            if (needfree && pktopt->ip6po_dest2)
                  free(pktopt->ip6po_dest2, M_IP6OPT);
            pktopt->ip6po_dest2 = NULL;
      }
}

#define PKTOPT_EXTHDRCPY(type) \
do {\
      if (src->type) {\
            int hlen =\
                  (((struct ip6_ext *)src->type)->ip6e_len + 1) << 3;\
            dst->type = malloc(hlen, M_IP6OPT, canwait);\
            if (dst->type == NULL && canwait == M_NOWAIT)\
                  goto bad;\
            bcopy(src->type, dst->type, hlen);\
      }\
} while (0)

struct ip6_pktopts *
ip6_copypktopts(src, canwait)
      struct ip6_pktopts *src;
      int canwait;
{
      struct ip6_pktopts *dst;

      if (src == NULL) {
            printf("ip6_clearpktopts: invalid argument\n");
            return(NULL);
      }

      dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
      if (dst == NULL && canwait == M_NOWAIT)
            goto bad;
      bzero(dst, sizeof(*dst));
      dst->needfree = 1;

      dst->ip6po_hlim = src->ip6po_hlim;
      dst->ip6po_tclass = src->ip6po_tclass;
      dst->ip6po_flags = src->ip6po_flags;
      if (src->ip6po_pktinfo) {
            dst->ip6po_pktinfo = malloc(sizeof(*dst->ip6po_pktinfo),
                                  M_IP6OPT, canwait);
            if (dst->ip6po_pktinfo == NULL && canwait == M_NOWAIT)
                  goto bad;
            *dst->ip6po_pktinfo = *src->ip6po_pktinfo;
      }
      if (src->ip6po_nexthop) {
            dst->ip6po_nexthop = malloc(src->ip6po_nexthop->sa_len,
                                  M_IP6OPT, canwait);
            if (dst->ip6po_nexthop == NULL && canwait == M_NOWAIT)
                  goto bad;
            bcopy(src->ip6po_nexthop, dst->ip6po_nexthop,
                  src->ip6po_nexthop->sa_len);
      }
      PKTOPT_EXTHDRCPY(ip6po_hbh);
      PKTOPT_EXTHDRCPY(ip6po_dest1);
      PKTOPT_EXTHDRCPY(ip6po_dest2);
      PKTOPT_EXTHDRCPY(ip6po_rthdr); /* not copy the cached route */
      return(dst);

  bad:
      printf("ip6_copypktopts: copy failed");
      if (dst->ip6po_pktinfo) free(dst->ip6po_pktinfo, M_IP6OPT);
      if (dst->ip6po_nexthop) free(dst->ip6po_nexthop, M_IP6OPT);
      if (dst->ip6po_hbh) free(dst->ip6po_hbh, M_IP6OPT);
      if (dst->ip6po_dest1) free(dst->ip6po_dest1, M_IP6OPT);
      if (dst->ip6po_dest2) free(dst->ip6po_dest2, M_IP6OPT);
      if (dst->ip6po_rthdr) free(dst->ip6po_rthdr, M_IP6OPT);
      return(NULL);
}
#undef PKTOPT_EXTHDRCPY

void
ip6_freepcbopts(pktopt)
      struct ip6_pktopts *pktopt;
{
      if (pktopt == NULL)
            return;

      ip6_clearpktopts(pktopt, -1);

      free(pktopt, M_IP6OPT);
}

/*
 * Set the IP6 multicast options in response to user setsockopt().
 */
static int
ip6_setmoptions(optname, im6op, m)
      int optname;
      struct ip6_moptions **im6op;
      struct mbuf *m;
{
      int error = 0;
      u_int loop, ifindex;
      struct ipv6_mreq *mreq;
      struct ifnet *ifp;
      struct ip6_moptions *im6o = *im6op;
      struct route ro;
      struct sockaddr_in6 *dst;
      struct in6_multi_mship *imm;

      if (im6o == NULL) {
            /*
             * No multicast option buffer attached to the pcb;
             * allocate one and initialize to default values.
             */
            im6o = (struct ip6_moptions *)
                  malloc(sizeof(*im6o), M_IPMOPTS, M_WAITOK);
            *im6op = im6o;
            im6o->im6o_multicast_ifp = NULL;
            im6o->im6o_multicast_hlim = ip6_defmcasthlim;
            im6o->im6o_multicast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
            LIST_INIT(&im6o->im6o_memberships);
      }

      switch (optname) {

      case IPV6_MULTICAST_IF:
            /*
             * Select the interface for outgoing multicast packets.
             */
            if (m == NULL || m->m_len != sizeof(u_int)) {
                  error = EINVAL;
                  break;
            }
            bcopy(mtod(m, u_int *), &ifindex, sizeof(ifindex));
            if (ifindex < 0 || if_index < ifindex) {
                  error = ENXIO;    /* XXX EINVAL? */
                  break;
            }
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
            ifp = ifnet_byindex(ifindex);
#else
            ifp = ifindex2ifnet[ifindex];
#endif
            if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
                  error = EADDRNOTAVAIL;
                  break;
            }
            im6o->im6o_multicast_ifp = ifp;
            break;

      case IPV6_MULTICAST_HOPS:
          {
            /*
             * Set the IP6 hoplimit for outgoing multicast packets.
             */
            int optval;
            if (m == NULL || m->m_len != sizeof(int)) {
                  error = EINVAL;
                  break;
            }
            bcopy(mtod(m, u_int *), &optval, sizeof(optval));
            if (optval < -1 || optval >= 256)
                  error = EINVAL;
            else if (optval == -1)
                  im6o->im6o_multicast_hlim = ip6_defmcasthlim;
            else
                  im6o->im6o_multicast_hlim = optval;
            break;
          }

      case IPV6_MULTICAST_LOOP:
            /*
             * Set the loopback flag for outgoing multicast packets.
             * Must be zero or one.
             */
            if (m == NULL || m->m_len != sizeof(u_int)) {
                  error = EINVAL;
                  break;
            }
            bcopy(mtod(m, u_int *), &loop, sizeof(loop));
            if (loop > 1) {
                  error = EINVAL;
                  break;
            }
            im6o->im6o_multicast_loop = loop;
            break;

      case IPV6_JOIN_GROUP:
            /*
             * Add a multicast group membership.
             * Group must be a valid IP6 multicast address.
             */
            if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
                  error = EINVAL;
                  break;
            }
            mreq = mtod(m, struct ipv6_mreq *);
            if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
                  /*
                   * We use the unspecified address to specify to accept
                   * all multicast addresses. Only super user is allowed
                   * to do this.
                   */
            } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
                  error = EINVAL;
                  break;
            }

            /*
             * If the interface is specified, validate it.
             */
            if (mreq->ipv6mr_interface < 0
             || if_index < mreq->ipv6mr_interface) {
                  error = ENXIO;    /* XXX EINVAL? */
                  break;
            }
            /*
             * If no interface was explicitly specified, choose an
             * appropriate one according to the given multicast address.
             */
            if (mreq->ipv6mr_interface == 0) {
                  /*
                   * Look up the routing table for the
                   * address, and choose the outgoing interface.
                   *   XXX: is it a good approach?
                   */
                  ro.ro_rt = NULL;
                  dst = (struct sockaddr_in6 *)&ro.ro_dst;
                  bzero(dst, sizeof(*dst));
                  dst->sin6_len = sizeof(struct sockaddr_in6);
                  dst->sin6_family = AF_INET6;
                  dst->sin6_addr = mreq->ipv6mr_multiaddr;
                  rtalloc((struct route *)&ro);
                  if (ro.ro_rt == NULL) {
                        error = EADDRNOTAVAIL;
                        break;
                  }
                  ifp = ro.ro_rt->rt_ifp;
                  rtfree(ro.ro_rt);
            } else {
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
                  ifp = ifnet_byindex(mreq->ipv6mr_interface);
#else
                  ifp = ifindex2ifnet[mreq->ipv6mr_interface];
#endif
            }

            /*
             * See if we found an interface, and confirm that it
             * supports multicast
             */
            if (ifp == NULL || (ifp->if_flags & IFF_MULTICAST) == 0) {
                  error = EADDRNOTAVAIL;
                  break;
            }
            /*
             * Put interface index into the multicast address,
             * if the address has interface/link-local scope.
             * XXX: the embedded form is a KAME-local hack. 
             */
            if (IN6_IS_ADDR_MC_INTFACELOCAL(&mreq->ipv6mr_multiaddr) ||
                IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
                  mreq->ipv6mr_multiaddr.s6_addr16[1]
                        = htons(mreq->ipv6mr_interface);
            }
            /*
             * See if the membership already exists.
             */
            for (imm = im6o->im6o_memberships.lh_first;
                 imm != NULL; imm = imm->i6mm_chain.le_next)
                  if (imm->i6mm_maddr->in6m_ifp == ifp &&
                      IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
                                     &mreq->ipv6mr_multiaddr))
                        break;
            if (imm != NULL) {
                  error = EADDRINUSE;
                  break;
            }
            /*
             * Everything looks good; add a new record to the multicast
             * address list for the given interface.
             */
            imm = in6_joingroup(ifp, &mreq->ipv6mr_multiaddr, &error);
            if (!imm)
                  break;
            LIST_INSERT_HEAD(&im6o->im6o_memberships, imm, i6mm_chain);
            break;

      case IPV6_LEAVE_GROUP:
            /*
             * Drop a multicast group membership.
             * Group must be a valid IP6 multicast address.
             */
            if (m == NULL || m->m_len != sizeof(struct ipv6_mreq)) {
                  error = EINVAL;
                  break;
            }
            mreq = mtod(m, struct ipv6_mreq *);
            if (IN6_IS_ADDR_UNSPECIFIED(&mreq->ipv6mr_multiaddr)) {
            } else if (!IN6_IS_ADDR_MULTICAST(&mreq->ipv6mr_multiaddr)) {
                  error = EINVAL;
                  break;
            }
            /*
             * If an interface address was specified, get a pointer
             * to its ifnet structure.
             */
            if (mreq->ipv6mr_interface < 0
             || if_index < mreq->ipv6mr_interface) {
                  error = ENXIO;    /* XXX EINVAL? */
                  break;
            }
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
            ifp = ifnet_byindex(mreq->ipv6mr_interface);
#else
            ifp = ifindex2ifnet[mreq->ipv6mr_interface];
#endif
            /*
             * Put interface index into the multicast address,
             * if the address has interface/link-local scope.
             */
            if (IN6_IS_ADDR_MC_INTFACELOCAL(&mreq->ipv6mr_multiaddr) ||
                IN6_IS_ADDR_MC_LINKLOCAL(&mreq->ipv6mr_multiaddr)) {
                  mreq->ipv6mr_multiaddr.s6_addr16[1]
                        = htons(mreq->ipv6mr_interface);
            }
            /*
             * Find the membership in the membership list.
             */
            for (imm = im6o->im6o_memberships.lh_first;
                 imm != NULL; imm = imm->i6mm_chain.le_next) {
                  if ((ifp == NULL ||
                       imm->i6mm_maddr->in6m_ifp == ifp) &&
                      IN6_ARE_ADDR_EQUAL(&imm->i6mm_maddr->in6m_addr,
                                     &mreq->ipv6mr_multiaddr))
                        break;
            }
            if (imm == NULL) {
                  /* Unable to resolve interface */
                  error = EADDRNOTAVAIL;
                  break;
            }
            /*
             * Give up the multicast address record to which the
             * membership points.
             */
            LIST_REMOVE(imm, i6mm_chain);
            in6_leavegroup(imm);
            break;

      default:
            error = EOPNOTSUPP;
            break;
      }

      /*
       * If all options have default values, no need to keep the mbuf.
       */
      if (im6o->im6o_multicast_ifp == NULL &&
          im6o->im6o_multicast_hlim == ip6_defmcasthlim &&
          im6o->im6o_multicast_loop == IPV6_DEFAULT_MULTICAST_LOOP &&
          im6o->im6o_memberships.lh_first == NULL) {
            free(*im6op, M_IPMOPTS);
            *im6op = NULL;
      }

      return(error);
}

/*
 * Return the IP6 multicast options in response to user getsockopt().
 */
static int
ip6_getmoptions(optname, im6o, mp)
      int optname;
      struct ip6_moptions *im6o;
      struct mbuf **mp;
{
      u_int *hlim, *loop, *ifindex;

#ifdef __FreeBSD__
      *mp = m_get(M_WAIT, MT_HEADER);           /* XXX */
#else
      *mp = m_get(M_WAIT, MT_SOOPTS);
#endif

      switch (optname) {

      case IPV6_MULTICAST_IF:
            ifindex = mtod(*mp, u_int *);
            (*mp)->m_len = sizeof(u_int);
            if (im6o == NULL || im6o->im6o_multicast_ifp == NULL)
                  *ifindex = 0;
            else
                  *ifindex = im6o->im6o_multicast_ifp->if_index;
            return(0);

      case IPV6_MULTICAST_HOPS:
            hlim = mtod(*mp, u_int *);
            (*mp)->m_len = sizeof(u_int);
            if (im6o == NULL)
                  *hlim = ip6_defmcasthlim;
            else
                  *hlim = im6o->im6o_multicast_hlim;
            return(0);

      case IPV6_MULTICAST_LOOP:
            loop = mtod(*mp, u_int *);
            (*mp)->m_len = sizeof(u_int);
            if (im6o == NULL)
                  *loop = ip6_defmcasthlim;
            else
                  *loop = im6o->im6o_multicast_loop;
            return(0);

      default:
            return(EOPNOTSUPP);
      }
}

/*
 * Discard the IP6 multicast options.
 */
void
ip6_freemoptions(im6o)
      struct ip6_moptions *im6o;
{
      struct in6_multi_mship *imm;

      if (im6o == NULL)
            return;

      while ((imm = im6o->im6o_memberships.lh_first) != NULL) {
            LIST_REMOVE(imm, i6mm_chain);
            in6_leavegroup(imm);
      }
      free(im6o, M_IPMOPTS);
}

/*
 * Set IPv6 outgoing packet options based on advanced API.
 */
int
ip6_setpktoptions(control, opt, stickyopt, priv, needcopy)
      struct mbuf *control;
      struct ip6_pktopts *opt, *stickyopt;
      int priv, needcopy;
{
      struct cmsghdr *cm = 0;

      if (control == 0 || opt == 0)
            return(EINVAL);

      if (stickyopt) {
            /*
             * If stickyopt is provided, make a local copy of the options
             * for this particular packet, then override them by ancillary
             * objects.
             * XXX: need to gain a reference for the cached route of the
             * next hop in case of the overriding.
             */
            *opt = *stickyopt;
            if (opt->ip6po_nextroute.ro_rt)
                  opt->ip6po_nextroute.ro_rt->rt_refcnt++;
      } else
            init_ip6pktopts(opt);
      opt->needfree = needcopy;

      /*
       * XXX: Currently, we assume all the optional information is stored
       * in a single mbuf.
       */
      if (control->m_next)
            return(EINVAL);

      for (; control->m_len; control->m_data += CMSG_ALIGN(cm->cmsg_len),
                 control->m_len -= CMSG_ALIGN(cm->cmsg_len)) {
            int error;

            if (control->m_len < CMSG_LEN(0))
                  return(EINVAL);

            cm = mtod(control, struct cmsghdr *);
            if (cm->cmsg_len == 0 || cm->cmsg_len > control->m_len)
                  return(EINVAL);
            if (cm->cmsg_level != IPPROTO_IPV6)
                  continue;

            error = ip6_setpktoption(cm->cmsg_type, CMSG_DATA(cm),
                               cm->cmsg_len - CMSG_LEN(0),
                               opt, priv, needcopy, 1);
            if (error)
                  return(error);
      }

      return(0);
}

/*
 * Set a particular packet option, as a sticky option or an ancillary data
 * item.  "len" can be 0 only when it's a sticky option.
 * We have 4 cases of combination of "sticky" and "cmsg":
 * "sticky=0, cmsg=0": impossible
 * "sticky=0, cmsg=1": RFC2292 or rfc2292bis ancillary data
 * "sticky=1, cmsg=0": rfc2292bis socket option
 * "sticky=1, cmsg=1": RFC2292 socket option
 */
static int
ip6_setpktoption(optname, buf, len, opt, priv, sticky, cmsg)
      int optname, len, priv, cmsg;
      u_char *buf;
      struct ip6_pktopts *opt;
      int sticky;
{
      if (!sticky && !cmsg) {
#ifdef DIAGNOSTIC
            printf("ip6_setpktoption: impossible case\n");
#endif
            return(EINVAL);
      }

      /*
       * IPV6_2292xxx is for backward compatibility to RFC2292, and should
       * not be specified in the context of rfc2292bis.  Conversely,
       * rfc2292bis types should not be specified in the context of RFC2292.
       *
       */
      if (!cmsg) {
            switch (optname) {
            case IPV6_2292PKTINFO:
            case IPV6_2292HOPLIMIT:
            case IPV6_2292NEXTHOP:
            case IPV6_2292HOPOPTS:
            case IPV6_2292DSTOPTS:
            case IPV6_2292RTHDR:
            case IPV6_2292PKTOPTIONS:
                  return(ENOPROTOOPT);
            }
      }
      if (sticky && cmsg) {
            switch (optname) {
            case IPV6_PKTINFO:
            case IPV6_HOPLIMIT:
            case IPV6_NEXTHOP:
            case IPV6_HOPOPTS:
            case IPV6_DSTOPTS:
            case IPV6_RTHDRDSTOPTS:
            case IPV6_RTHDR:
            case IPV6_REACHCONF:
            case IPV6_USE_MIN_MTU:
            case IPV6_DONTFRAG:
            case IPV6_OTCLASS:
            case IPV6_TCLASS:
                  return(ENOPROTOOPT);
            }
      }

      switch (optname) {
      case IPV6_2292PKTINFO:
      case IPV6_PKTINFO:
      {
            struct ifnet *ifp = NULL;
            struct in6_pktinfo *pktinfo;

            if (len != sizeof(struct in6_pktinfo))
                  return(EINVAL);

            pktinfo = (struct in6_pktinfo *)buf;

            /*
             * An application can clear any sticky IPV6_PKTINFO option by
             * doing a "regular" setsockopt with ipi6_addr being
             * in6addr_any and ipi6_ifindex being zero.
             * [rfc2292bis-02, Section 6]
             */
            if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo) {
                  if (pktinfo->ipi6_ifindex == 0 &&
                      IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
                        ip6_clearpktopts(opt, optname);
                        break;
                  }
            }

            /* validate the interface index if specified. */
            if (pktinfo->ipi6_ifindex > if_index ||
                pktinfo->ipi6_ifindex < 0) {
                   return(ENXIO);
            }
            if (pktinfo->ipi6_ifindex) {
#if defined(__FreeBSD__) && __FreeBSD__ >= 5
                  ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
#else
                  ifp = ifindex2ifnet[pktinfo->ipi6_ifindex];
#endif
                  if (ifp == NULL)
                        return(ENXIO);
            }

            /*
             * We store the address anyway, and let in6_selectsrc()
             * validate the specified address.  This is because ipi6_addr
             * may not have enough information about its scope zone, and
             * we may need additional information (such as outgoing
             * interface or the scope zone of a destination address) to
             * disambiguate the scope.
             * XXX: the delay of the validation may confuse the
             * application when it is used as a sticky option.
             */
            if (sticky) {
                  if (opt->ip6po_pktinfo == NULL) {
                        opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
                                              M_IP6OPT,
                                              M_WAITOK);
                  }
                  bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
            } else
                  opt->ip6po_pktinfo = pktinfo;
            break;
      }

      case IPV6_2292HOPLIMIT:
      case IPV6_HOPLIMIT:
      {
            int *hlimp;

            /*
             * rfc2292bis-03 obsoleted the usage of sticky IPV6_HOPLIMIT
             * to simplify the ordering among hoplimit options.
             */
            if (optname == IPV6_HOPLIMIT && sticky)
                  return(ENOPROTOOPT);

            if (len != sizeof(int))
                  return(EINVAL);
            hlimp = (int *)buf;
            if (*hlimp < -1 || *hlimp > 255)
                  return(EINVAL);

            opt->ip6po_hlim = *hlimp;
            break;
      }

      case IPV6_OTCLASS:
            if (len != sizeof(u_int8_t))
                  return(EINVAL);

            opt->ip6po_tclass = *(u_int8_t *)buf;
            break;

      case IPV6_TCLASS:
      {
            int tclass;

            if (len != sizeof(int))
                  return(EINVAL);
            tclass = *(int *)buf;
            if (tclass < -1 || tclass > 255)
                  return(EINVAL);

            opt->ip6po_tclass = tclass;
            break;
      }

      case IPV6_2292NEXTHOP:
      case IPV6_NEXTHOP:

            if (len == 0) {   /* just remove the option */
                  ip6_clearpktopts(opt, IPV6_NEXTHOP);
                  break;
            }

            /* check if cmsg_len is large enough for sa_len */
            if (len < sizeof(struct sockaddr) || len < *buf)
                  return(EINVAL);

            switch (((struct sockaddr *)buf)->sa_family) {
            case AF_INET6:
            {
                  struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)buf;
                  int error;

                  if (sa6->sin6_len != sizeof(struct sockaddr_in6))
                        return(EINVAL);

                  if (IN6_IS_ADDR_UNSPECIFIED(&sa6->sin6_addr) ||
                      IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
                        return(EINVAL);
                  }
                  if ((error = scope6_check_id(sa6, ip6_use_defzone))
                      != 0) {
                        return(error);
                  }
#ifndef SCOPEDROUTING
                  sa6->sin6_scope_id = 0; /* XXX */
#endif
                  break;
            }
            case AF_LINK:     /* should eventually be supported */
            default:
                  return(EAFNOSUPPORT);
            }

            /* turn off the previous option, then set the new option. */
            ip6_clearpktopts(opt, IPV6_NEXTHOP);
            if (sticky) {
                  opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_WAITOK);
                  bcopy(buf, opt->ip6po_nexthop, *buf);
            } else
                  opt->ip6po_nexthop = (struct sockaddr *)buf;
            break;
            
      case IPV6_2292HOPOPTS:
      case IPV6_HOPOPTS:
      {
            struct ip6_hbh *hbh;
            int hbhlen;

            /*
             * XXX: We don't allow a non-privileged user to set ANY HbH
             * options, since per-option restriction has too much
             * overhead.
             */

            if (len == 0) {
                  ip6_clearpktopts(opt, IPV6_HOPOPTS);
                  break;      /* just remove the option */
            }

            /* message length validation */
            if (len < sizeof(struct ip6_hbh))
                  return(EINVAL);
            hbh = (struct ip6_hbh *)buf;
            hbhlen = (hbh->ip6h_len + 1) << 3;
            if (len != hbhlen)
                  return(EINVAL);

            /* turn off the previous option, then set the new option. */
            ip6_clearpktopts(opt, IPV6_HOPOPTS);
            if (sticky) {
                  opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_WAITOK);
                  bcopy(hbh, opt->ip6po_hbh, hbhlen);
            } else
                  opt->ip6po_hbh = hbh;

            break;
      }

      case IPV6_2292DSTOPTS:
      case IPV6_DSTOPTS:
      case IPV6_RTHDRDSTOPTS:
      {
            struct ip6_dest *dest, **newdest = NULL;
            int destlen;


            if (len == 0) {
                  ip6_clearpktopts(opt, optname);
                  break;      /* just remove the option */
            }

            /* message length validation */
            if (len < sizeof(struct ip6_dest))
                  return(EINVAL);
            dest = (struct ip6_dest *)buf;
            destlen = (dest->ip6d_len + 1) << 3;
            if (len != destlen)
                  return(EINVAL);

            /*
             * Determine the position that the destination options header
             * should be inserted; before or after the routing header.
             */
            switch (optname) {
            case IPV6_2292DSTOPTS:
                  /*
                   * The old advacned API is ambiguous on this point.
                   * Our approach is to determine the position based
                   * according to the existence of a routing header.
                   * Note, however, that this depends on the order of the
                   * extension headers in the ancillary data; the 1st
                   * part of the destination options header must appear
                   * before the routing header in the ancillary data,
                   * too.
                   * RFC2292bis solved the ambiguity by introducing
                   * separate ancillary data or option types.
                   */
                  if (opt->ip6po_rthdr == NULL)
                        newdest = &opt->ip6po_dest1;
                  else
                        newdest = &opt->ip6po_dest2;
                  break;
            case IPV6_RTHDRDSTOPTS:
                  newdest = &opt->ip6po_dest1;
                  break;
            case IPV6_DSTOPTS:
                  newdest = &opt->ip6po_dest2;
                  break;
            }

            /* turn off the previous option, then set the new option. */
            ip6_clearpktopts(opt, optname);
            if (sticky) {
                  *newdest = malloc(destlen, M_IP6OPT, M_WAITOK);
                  bcopy(dest, *newdest, destlen);
            } else
                  *newdest = dest;

            break;
      }

      case IPV6_2292RTHDR:
      case IPV6_RTHDR:
      {
            struct ip6_rthdr *rth;
            int rthlen;

            if (len == 0) {
                  ip6_clearpktopts(opt, IPV6_RTHDR);
                  break;      /* just remove the option */
            }

            /* message length validation */
            if (len < sizeof(struct ip6_rthdr))
                  return(EINVAL);
            rth = (struct ip6_rthdr *)buf;
            rthlen = (rth->ip6r_len + 1) << 3;
            if (len != rthlen)
                  return(EINVAL);

            switch (rth->ip6r_type) {
            case IPV6_RTHDR_TYPE_0:
                  if (rth->ip6r_len == 0) /* must contain one addr */
                        return(EINVAL);
                  if (rth->ip6r_len % 2) /* length must be even */
                        return(EINVAL);
                  if (rth->ip6r_len / 2 != rth->ip6r_segleft)
                        return(EINVAL);
                  break;
            default:
                  return(EINVAL);   /* not supported */
            }

            /* turn off the previous option */
            ip6_clearpktopts(opt, IPV6_RTHDR);
            if (sticky) {
                  opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_WAITOK);
                  bcopy(rth, opt->ip6po_rthdr, rthlen);
            } else
                  opt->ip6po_rthdr = rth;
            
            break;
      }

      case IPV6_REACHCONF:
            if (!cmsg)
                  return(ENOPROTOOPT);

#if 0
            /*
             * it looks dangerous to allow IPV6_REACHCONF to
             * normal user.  it affects the ND state (system state)
             * and can affect communication by others - jinmei
             */
            if (!priv)
                  return(EPERM);
#else
            /*
             * we limit max # of subsequent userland reachability
             * conformation by using ln->ln_byhint.
             */
#endif
            if (len)
                  return(EINVAL);
            opt->ip6po_flags |= IP6PO_REACHCONF;
            break;

      case IPV6_USE_MIN_MTU:
      case IPV6_DONTFRAG:
      {
            int on, flag = 0;

            if (len != sizeof(int))
                  return(EINVAL);
            on = *(int *)buf;

            switch (optname) {
            case IPV6_USE_MIN_MTU:
                  flag = IP6PO_MINMTU;
                  break;
            case IPV6_DONTFRAG:
                  flag = IP6PO_DONTFRAG;
                  break;
            }

            if (on)
                  opt->ip6po_flags |= flag;
            else
                  opt->ip6po_flags &= ~flag;
            break;
      }

      default:
            return(ENOPROTOOPT);    
      } /* end of switch */

      return(0);
}

/*
 * Routine called from ip6_output() to loop back a copy of an IP6 multicast
 * packet to the input queue of a specified interface.  Note that this
 * calls the output routine of the loopback "driver", but with an interface
 * pointer that might NOT be &loif -- easier than replicating that code here.
 */
void
ip6_mloopback(ifp, m, dst)
      struct ifnet *ifp;
      struct mbuf *m;
      struct sockaddr_in6 *dst;
{
      struct mbuf *copym;
      struct ip6_hdr *ip6;

      copym = m_copy(m, 0, M_COPYALL);
      if (copym == NULL)
            return;

      /*
       * Make sure to deep-copy IPv6 header portion in case the data
       * is in an mbuf cluster, so that we can safely override the IPv6
       * header portion later.
       */
      if ((copym->m_flags & M_EXT) != 0 ||
          copym->m_len < sizeof(struct ip6_hdr)) {
            copym = m_pullup(copym, sizeof(struct ip6_hdr));
            if (copym == NULL)
                  return;
      }

#ifdef DIAGNOSTIC
      if (copym->m_len < sizeof(*ip6)) {
            m_freem(copym);
            return;
      }
#endif

      ip6 = mtod(copym, struct ip6_hdr *);
#ifndef SCOPEDROUTING
      /*
       * clear embedded scope identifiers if necessary.
       * in6_clearscope will touch the addresses only when necessary.
       */
      in6_clearscope(&ip6->ip6_src);
      in6_clearscope(&ip6->ip6_dst);
#endif

#if defined(__FreeBSD__) && __FreeBSD__ >= 3
#if (__FreeBSD_version >= 410000)
      (void)if_simloop(ifp, copym, dst->sin6_family, (int)NULL);
#else
      (void)if_simloop(ifp, copym, (struct sockaddr *)dst, NULL);
#endif
#else
      (void)looutput(ifp, copym, (struct sockaddr *)dst, NULL);
#endif
}

/*
 * Chop IPv6 header off from the payload.
 */
static int
ip6_splithdr(m, exthdrs)
      struct mbuf *m;
      struct ip6_exthdrs *exthdrs;
{
      struct mbuf *mh;
      struct ip6_hdr *ip6;

      ip6 = mtod(m, struct ip6_hdr *);
      if (m->m_len > sizeof(*ip6)) {
            MGETHDR(mh, M_DONTWAIT, MT_HEADER);
            if (mh == 0) {
                  m_freem(m);
                  return ENOBUFS;
            }
#ifdef __OpenBSD__
            M_MOVE_PKTHDR(mh, m);
#else
            M_COPY_PKTHDR(mh, m);
#endif
            MH_ALIGN(mh, sizeof(*ip6));
            m->m_flags &= ~M_PKTHDR;
            m->m_len -= sizeof(*ip6);
            m->m_data += sizeof(*ip6);
            mh->m_next = m;
            m = mh;
            m->m_len = sizeof(*ip6);
            bcopy((caddr_t)ip6, mtod(m, caddr_t), sizeof(*ip6));
      }
      exthdrs->ip6e_ip6 = m;
      return 0;
}

/*
 * Compute IPv6 extension header length.
 */
#ifdef HAVE_NRL_INPCB
# define in6pcb   inpcb
# define in6p_outputopts      inp_outputopts6
#endif
int
ip6_optlen(in6p)
      struct in6pcb *in6p;
{
      int len;

      if (!in6p->in6p_outputopts)
            return 0;

      len = 0;
#define elen(x) \
    (((struct ip6_ext *)(x)) ? (((struct ip6_ext *)(x))->ip6e_len + 1) << 3 : 0)

      len += elen(in6p->in6p_outputopts->ip6po_hbh);
      if (in6p->in6p_outputopts->ip6po_rthdr)
            /* dest1 is valid with rthdr only */
            len += elen(in6p->in6p_outputopts->ip6po_dest1);
      len += elen(in6p->in6p_outputopts->ip6po_rthdr);
      len += elen(in6p->in6p_outputopts->ip6po_dest2);
      return len;
#undef elen
}
#ifdef HAVE_NRL_INPCB
# undef in6pcb
# undef in6p_outputopts
#endif

Generated by  Doxygen 1.6.0   Back to index