Initial import

Code is based on FreeBSD 8.2 with USB support from Sebastian Huber
and Thomas Doerfler. Initial TCP/IP stack work is from Kevel Kirspel.

1 files changed, 2928 insertions, 0 deletions

diff --git a/rtems/freebsd/netinet6/ip6_output.c b/rtems/freebsd/netinet6/ip6_output.c
new file mode 100644
index 00000000..043bcaca
--- /dev/null
+++ b/rtems/freebsd/netinet6/ip6_output.c
@@ -0,0 +1,2928 @@
+#include <rtems/freebsd/machine/rtems-bsd-config.h>
+
+/*-
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	$KAME: ip6_output.c,v 1.279 2002/01/26 06:12:30 jinmei Exp $
+ */
+
+/*-
+ * 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.
+ * 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 <rtems/freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/freebsd/local/opt_inet.h>
+#include <rtems/freebsd/local/opt_inet6.h>
+#include <rtems/freebsd/local/opt_ipsec.h>
+#include <rtems/freebsd/local/opt_sctp.h>
+
+#include <rtems/freebsd/sys/param.h>
+#include <rtems/freebsd/sys/kernel.h>
+#include <rtems/freebsd/sys/malloc.h>
+#include <rtems/freebsd/sys/mbuf.h>
+#include <rtems/freebsd/sys/errno.h>
+#include <rtems/freebsd/sys/priv.h>
+#include <rtems/freebsd/sys/proc.h>
+#include <rtems/freebsd/sys/protosw.h>
+#include <rtems/freebsd/sys/socket.h>
+#include <rtems/freebsd/sys/socketvar.h>
+#include <rtems/freebsd/sys/syslog.h>
+#include <rtems/freebsd/sys/ucred.h>
+
+#include <rtems/freebsd/net/if.h>
+#include <rtems/freebsd/net/netisr.h>
+#include <rtems/freebsd/net/route.h>
+#include <rtems/freebsd/net/pfil.h>
+#include <rtems/freebsd/net/vnet.h>
+
+#include <rtems/freebsd/netinet/in.h>
+#include <rtems/freebsd/netinet/in_var.h>
+#include <rtems/freebsd/netinet6/in6_var.h>
+#include <rtems/freebsd/netinet/ip6.h>
+#include <rtems/freebsd/netinet/icmp6.h>
+#include <rtems/freebsd/netinet6/ip6_var.h>
+#include <rtems/freebsd/netinet/in_pcb.h>
+#include <rtems/freebsd/netinet/tcp_var.h>
+#include <rtems/freebsd/netinet6/nd6.h>
+
+#ifdef IPSEC
+#include <rtems/freebsd/netipsec/ipsec.h>
+#include <rtems/freebsd/netipsec/ipsec6.h>
+#include <rtems/freebsd/netipsec/key.h>
+#include <rtems/freebsd/netinet6/ip6_ipsec.h>
+#endif /* IPSEC */
+#ifdef SCTP
+#include <rtems/freebsd/netinet/sctp.h>
+#include <rtems/freebsd/netinet/sctp_crc32.h>
+#endif
+
+#include <rtems/freebsd/netinet6/ip6protosw.h>
+#include <rtems/freebsd/netinet6/scope6_var.h>
+
+extern int in6_mcast_loop;
+
+struct ip6_exthdrs {
+	struct mbuf *ip6e_ip6;
+	struct mbuf *ip6e_hbh;
+	struct mbuf *ip6e_dest1;
+	struct mbuf *ip6e_rthdr;
+	struct mbuf *ip6e_dest2;
+};
+
+static int ip6_pcbopt __P((int, u_char *, int, struct ip6_pktopts **,
+			   struct ucred *, int));
+static int ip6_pcbopts __P((struct ip6_pktopts **, struct mbuf *,
+	struct socket *, struct sockopt *));
+static int ip6_getpcbopt(struct ip6_pktopts *, int, struct sockopt *);
+static int ip6_setpktopt __P((int, u_char *, int, struct ip6_pktopts *,
+	struct ucred *, int, int, int));
+
+static int ip6_copyexthdr(struct mbuf **, caddr_t, int);
+static int ip6_insertfraghdr __P((struct mbuf *, struct mbuf *, int,
+	struct ip6_frag **));
+static int ip6_insert_jumboopt(struct ip6_exthdrs *, u_int32_t);
+static int ip6_splithdr(struct mbuf *, struct ip6_exthdrs *);
+static int ip6_getpmtu __P((struct route_in6 *, struct route_in6 *,
+	struct ifnet *, struct in6_addr *, u_long *, int *));
+static int copypktopts(struct ip6_pktopts *, struct ip6_pktopts *, int);
+
+
+/*
+ * Make an extension header from option data.  hp is the source, and
+ * mp is the destination.
+ */
+#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 (/*CONSTCOND*/ 0)
+
+/*
+ * Form a chain of extension headers.
+ * m is the extension header mbuf
+ * mp is the previous mbuf in the chain
+ * p is the next header
+ * i is the type of option.
+ */
+#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 (/*CONSTCOND*/ 0)
+
+/*
+ * 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.
+ *
+ * ifpp - XXX: just for statistics
+ */
+int
+ip6_output(struct mbuf *m0, struct ip6_pktopts *opt,
+    struct route_in6 *ro, int flags, struct ip6_moptions *im6o,
+    struct ifnet **ifpp, struct inpcb *inp)
+{
+	struct ip6_hdr *ip6, *mhip6;
+	struct ifnet *ifp, *origifp;
+	struct mbuf *m = m0;
+	struct mbuf *mprev = NULL;
+	int hlen, tlen, len, off;
+	struct route_in6 ip6route;
+	struct rtentry *rt = NULL;
+	struct sockaddr_in6 *dst, src_sa, dst_sa;
+	struct in6_addr odst;
+	int error = 0;
+	struct in6_ifaddr *ia = NULL;
+	u_long mtu;
+	int alwaysfrag, dontfrag;
+	u_int32_t optlen = 0, plen = 0, unfragpartlen = 0;
+	struct ip6_exthdrs exthdrs;
+	struct in6_addr finaldst, src0, dst0;
+	u_int32_t zone;
+	struct route_in6 *ro_pmtu = NULL;
+	int hdrsplit = 0;
+	int needipsec = 0;
+#ifdef SCTP
+	int sw_csum;
+#endif
+#ifdef IPSEC
+	struct ipsec_output_state state;
+	struct ip6_rthdr *rh = NULL;
+	int needipsectun = 0;
+	int segleft_org = 0;
+	struct secpolicy *sp = NULL;
+#endif /* IPSEC */
+
+	ip6 = mtod(m, struct ip6_hdr *);
+	if (ip6 == NULL) {
+		printf ("ip6 is NULL");
+		goto bad;
+	}
+
+	finaldst = ip6->ip6_dst;
+
+	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 sense with a routing header.
+			 * See Section 9.2 of RFC 3542.
+			 * 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);
+	}
+
+	/*
+	 * IPSec checking which handles several cases.
+	 * FAST IPSEC: We re-injected the packet.
+	 */
+#ifdef IPSEC
+	switch(ip6_ipsec_output(&m, inp, &flags, &error, &ifp, &sp))
+	{
+	case 1:                 /* Bad packet */
+		goto freehdrs;
+	case -1:                /* Do IPSec */
+		needipsec = 1;
+	case 0:                 /* No IPSec */
+	default:
+		break;
+	}
+#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;
+	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.
+	 */
+	if ((needipsec || optlen) && !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 *);
+
+	/* 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;
+	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;
+	}
+
+	/*
+	 * 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 IPSEC
+	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;
+
+	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 == EJUSTRETURN) {
+		/*
+		 * We had a SP with a level of 'use' and no SA. We
+		 * will just continue to process the packet without
+		 * IPsec processing.
+		 */
+		;
+	} else 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("[%s:%d] (ipsec): error code %d\n",
+			    __func__, __LINE__, error);
+			/* FALLTHROUGH */
+		case ENOENT:
+			/* don't show these error codes to the user */
+			error = 0;
+			break;
+		}
+		goto bad;
+	} else if (!needipsectun) {
+		/*
+		 * In the FAST IPSec case we have already
+		 * re-injected the packet and it has been freed
+		 * by the ipsec_done() function.  So, just clean
+		 * up after ourselves.
+		 */
+		m = NULL;
+		goto done;
+	}
+	if (exthdrs.ip6e_rthdr) {
+		/* ah6_output doesn't modify mbuf chain */
+		rh->ip6r_segleft = segleft_org;
+	}
+skip_ipsec2:;
+#endif /* IPSEC */
+
+	/*
+	 * If there is a routing header, discard the packet.
+	 */
+	if (exthdrs.ip6e_rthdr) {
+		 error = EINVAL;
+		 goto bad;
+	}
+
+	/* Source address validation */
+	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) &&
+	    (flags & IPV6_UNSPECSRC) == 0) {
+		error = EOPNOTSUPP;
+		V_ip6stat.ip6s_badscope++;
+		goto bad;
+	}
+	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src)) {
+		error = EOPNOTSUPP;
+		V_ip6stat.ip6s_badscope++;
+		goto bad;
+	}
+
+	V_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;
+	dst = (struct sockaddr_in6 *)&ro->ro_dst;
+
+again:
+	/*
+	 * if specified, try to fill in the traffic class field.
+	 * do not override if a non-zero value is already set.
+	 * we check the diffserv field and the ecn field separately.
+	 */
+	if (opt && opt->ip6po_tclass >= 0) {
+		int mask = 0;
+
+		if ((ip6->ip6_flow & htonl(0xfc << 20)) == 0)
+			mask |= 0xfc;
+		if ((ip6->ip6_flow & htonl(0x03 << 20)) == 0)
+			mask |= 0x03;
+		if (mask != 0)
+			ip6->ip6_flow |= htonl((opt->ip6po_tclass & mask) << 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 = V_ip6_defmcasthlim;
+	}
+
+#ifdef IPSEC
+	/*
+	 * We may re-inject packets into the stack here.
+	 */
+	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;
+		ro = (struct route_in6 *)state.ro;
+		dst = (struct sockaddr_in6 *)state.dst;
+		if (error == EJUSTRETURN) {
+			/*
+			 * We had a SP with a level of 'use' and no SA. We
+			 * will just continue to process the packet without
+			 * IPsec processing.
+			 */
+			;
+		} else 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("[%s:%d] (ipsec): error code %d\n",
+				    __func__, __LINE__, error);
+				/* FALLTHROUGH */
+			case ENOENT:
+				/* don't show these error codes to the user */
+				error = 0;
+				break;
+			}
+			goto bad;
+		} else {
+			/*
+			 * In the FAST IPSec case we have already
+			 * re-injected the packet and it has been freed
+			 * by the ipsec_done() function.  So, just clean
+			 * up after ourselves.
+			 */
+			m = NULL;
+			goto done;
+		}
+
+		exthdrs.ip6e_ip6 = m;
+	}
+#endif /* IPSEC */
+
+	/* adjust pointer */
+	ip6 = mtod(m, struct ip6_hdr *);
+
+	bzero(&dst_sa, sizeof(dst_sa));
+	dst_sa.sin6_family = AF_INET6;
+	dst_sa.sin6_len = sizeof(dst_sa);
+	dst_sa.sin6_addr = ip6->ip6_dst;
+	if ((error = in6_selectroute(&dst_sa, opt, im6o, ro,
+	    &ifp, &rt)) != 0) {
+		switch (error) {
+		case EHOSTUNREACH:
+			V_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 = dst_sa;	/* 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.  
+	 */
+	origifp = ifp;
+
+	src0 = ip6->ip6_src;
+	if (in6_setscope(&src0, origifp, &zone))
+		goto badscope;
+	bzero(&src_sa, sizeof(src_sa));
+	src_sa.sin6_family = AF_INET6;
+	src_sa.sin6_len = sizeof(src_sa);
+	src_sa.sin6_addr = ip6->ip6_src;
+	if (sa6_recoverscope(&src_sa) || zone != src_sa.sin6_scope_id)
+		goto badscope;
+
+	dst0 = ip6->ip6_dst;
+	if (in6_setscope(&dst0, origifp, &zone))
+		goto badscope;
+	/* re-initialize to be sure */
+	bzero(&dst_sa, sizeof(dst_sa));
+	dst_sa.sin6_family = AF_INET6;
+	dst_sa.sin6_len = sizeof(dst_sa);
+	dst_sa.sin6_addr = ip6->ip6_dst;
+	if (sa6_recoverscope(&dst_sa) || zone != dst_sa.sin6_scope_id) {
+		goto badscope;
+	}
+
+	/* We should use ia_ifp to support the case of 
+	 * sending packets to an address of our own.
+	 */
+	if (ia != NULL && ia->ia_ifp)
+		ifp = ia->ia_ifp;
+
+	/* scope check is done. */
+	goto routefound;
+
+  badscope:
+	V_ip6stat.ip6s_badscope++;
+	in6_ifstat_inc(origifp, ifs6_out_discard);
+	if (error == 0)
+		error = EHOSTUNREACH; /* XXX */
+	goto bad;
+
+  routefound:
+	if (rt && !IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+		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 {
+		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)) {
+			V_ip6stat.ip6s_noroute++;
+			in6_ifstat_inc(ifp, ifs6_out_discard);
+			error = ENETUNREACH;
+			goto bad;
+		}
+		if ((im6o == NULL && in6_mcast_loop) ||
+		    (im6o && im6o->im6o_multicast_loop)) {
+			/*
+			 * Loop back multicast datagram if not expressly
+			 * forbidden to do so, even if we have not joined
+			 * the address; protocols will filter it later,
+			 * thus deferring a hash lookup and lock acquisition
+			 * at the expense of an m_copym().
+			 */
+			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 (V_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;
+
+	/* Determine path MTU. */
+	if ((error = ip6_getpmtu(ro_pmtu, ro, ifp, &finaldst, &mtu,
+	    &alwaysfrag)) != 0)
+		goto bad;
+
+	/*
+	 * The caller of this function may specify to use the minimum MTU
+	 * in some cases.
+	 * An advanced API option (IPV6_USE_MIN_MTU) can also override MTU
+	 * setting.  The logic is a bit complicated; by default, unicast
+	 * packets will follow path MTU while multicast packets will be sent at
+	 * the minimum MTU.  If IP6PO_MINMTU_ALL is specified, all packets
+	 * including unicast ones will be sent at the minimum MTU.  Multicast
+	 * packets will always be sent at the minimum MTU unless
+	 * IP6PO_MINMTU_DISABLE is explicitly specified.
+	 * See RFC 3542 for more details.
+	 */
+	if (mtu > IPV6_MMTU) {
+		if ((flags & IPV6_MINMTU))
+			mtu = IPV6_MMTU;
+		else if (opt && opt->ip6po_minmtu == IP6PO_MINMTU_ALL)
+			mtu = IPV6_MMTU;
+		else if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
+			 (opt == NULL ||
+			  opt->ip6po_minmtu != IP6PO_MINMTU_DISABLE)) {
+			mtu = IPV6_MMTU;
+		}
+	}
+
+	/*
+	 * 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);
+
+	/*
+	 * 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;
+	}
+
+	/* Jump over all PFIL processing if hooks are not active. */
+	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
+		goto passout;
+
+	odst = ip6->ip6_dst;
+	/* Run through list of hooks for output packets. */
+	error = pfil_run_hooks(&V_inet6_pfil_hook, &m, ifp, PFIL_OUT, inp);
+	if (error != 0 || m == NULL)
+		goto done;
+	ip6 = mtod(m, struct ip6_hdr *);
+
+	/* See if destination IP address was changed by packet filter. */
+	if (!IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst)) {
+		m->m_flags |= M_SKIP_FIREWALL;
+		/* If destination is now ourself drop to ip6_input(). */
+		if (in6_localaddr(&ip6->ip6_dst)) {
+			if (m->m_pkthdr.rcvif == NULL)
+				m->m_pkthdr.rcvif = V_loif;
+			if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
+				m->m_pkthdr.csum_flags |=
+				    CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
+				m->m_pkthdr.csum_data = 0xffff;
+			}
+			m->m_pkthdr.csum_flags |=
+			    CSUM_IP_CHECKED | CSUM_IP_VALID;
+#ifdef SCTP
+			if (m->m_pkthdr.csum_flags & CSUM_SCTP)
+				m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
+#endif
+			error = netisr_queue(NETISR_IPV6, m);
+			goto done;
+		} else
+			goto again;	/* Redo the routing table lookup. */
+	}
+
+	/* XXX: IPFIREWALL_FORWARD */
+
+passout:
+	/*
+	 * Send the packet to the outgoing interface.
+	 * If necessary, do IPv6 fragmentation before sending.
+	 *
+	 * the logic here is rather complex:
+	 * 1: normal case (dontfrag == 0, alwaysfrag == 0)
+	 * 1-a:	send as is if tlen <= path mtu
+	 * 1-b:	fragment if tlen > path mtu
+	 *
+	 * 2: if user asks us not to fragment (dontfrag == 1)
+	 * 2-a:	send as is if tlen <= interface mtu
+	 * 2-b:	error if tlen > interface mtu
+	 *
+	 * 3: if we always need to attach fragment header (alwaysfrag == 1)
+	 *	always fragment
+	 *
+	 * 4: if dontfrag == 1 && alwaysfrag == 1
+	 *	error, as we cannot handle this conflicting request
+	 */
+#ifdef SCTP
+	sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_hwassist;
+	if (sw_csum & CSUM_SCTP) {
+		sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
+		sw_csum &= ~CSUM_SCTP;
+	}
+#endif
+	tlen = m->m_pkthdr.len;
+
+	if (opt && (opt->ip6po_flags & IP6PO_DONTFRAG))
+		dontfrag = 1;
+	else
+		dontfrag = 0;
+	if (dontfrag && alwaysfrag) {	/* case 4 */
+		/* conflicting request - can't transmit */
+		error = EMSGSIZE;
+		goto bad;
+	}
+	if (dontfrag && tlen > IN6_LINKMTU(ifp)) {	/* case 2-b */
+		/*
+		 * 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.)
+		 */
+		u_int32_t mtu32;
+		struct ip6ctlparam ip6cp;
+
+		mtu32 = (u_int32_t)mtu;
+		bzero(&ip6cp, sizeof(ip6cp));
+		ip6cp.ip6c_cmdarg = (void *)&mtu32;
+		pfctlinput2(PRC_MSGSIZE, (struct sockaddr *)&ro_pmtu->ro_dst,
+		    (void *)&ip6cp);
+
+		error = EMSGSIZE;
+		goto bad;
+	}
+
+	/*
+	 * transmit packet without fragmentation
+	 */
+	if (dontfrag || (!alwaysfrag && tlen <= mtu)) {	/* case 1-a and 2-a */
+		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. */
+			ia6->ia_ifa.if_opackets++;
+			ia6->ia_ifa.if_obytes += m->m_pkthdr.len;
+			ifa_free(&ia6->ia_ifa);
+		}
+		error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
+		goto done;
+	}
+
+	/*
+	 * try to fragment the packet.  case 1-b and 3
+	 */
+	if (mtu < IPV6_MMTU) {
+		/* path MTU cannot be less than IPV6_MMTU */
+		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_randomid());
+		u_char nextproto;
+
+		int qslots = ifp->if_snd.ifq_maxlen - ifp->if_snd.ifq_len;
+
+		/*
+		 * 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;
+
+		len = (mtu - hlen - sizeof(struct ip6_frag)) & ~7;
+		if (len < 8) {
+			error = EMSGSIZE;
+			in6_ifstat_inc(ifp, ifs6_out_fragfail);
+			goto bad;
+		}
+
+		/*
+		 * Verify that we have any chance at all of being able to queue
+		 *      the packet or packet fragments
+		 */
+		if (qslots <= 0 || ((u_int)qslots * (mtu - hlen)
+		    < tlen  /* - hlen */)) {
+			error = ENOBUFS;
+			V_ip6stat.ip6s_odropped++;
+			goto bad;
+		}
+
+		mnext = &m->m_nextpkt;
+
+		/*
+		 * Change the next header field of the last header in the
+		 * unfragmentable part.
+		 */
+		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;
+				V_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) {
+				V_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;
+				V_ip6stat.ip6s_odropped++;
+				goto sendorfree;
+			}
+			m_cat(m, m_frgpart);
+			m->m_pkthdr.len = len + hlen + sizeof(*ip6f);
+			m->m_pkthdr.rcvif = NULL;
+			ip6f->ip6f_reserved = 0;
+			ip6f->ip6f_ident = id;
+			ip6f->ip6f_nxt = nextproto;
+			V_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) {
+			/* Record statistics for this interface address. */
+			if (ia) {
+				ia->ia_ifa.if_opackets++;
+				ia->ia_ifa.if_obytes += m->m_pkthdr.len;
+			}
+			error = nd6_output(ifp, origifp, m, dst, ro->ro_rt);
+		} else
+			m_freem(m);
+	}
+
+	if (error == 0)
+		V_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);
+	}
+#ifdef IPSEC
+	if (sp != NULL)
+		KEY_FREESP(&sp);
+#endif
+
+	return (error);
+
+freehdrs:
+	m_freem(exthdrs.ip6e_hbh);	/* m_freem will check if mbuf is 0 */
+	m_freem(exthdrs.ip6e_dest1);
+	m_freem(exthdrs.ip6e_rthdr);
+	m_freem(exthdrs.ip6e_dest2);
+	/* FALLTHROUGH */
+bad:
+	if (m)
+		m_freem(m);
+	goto done;
+}
+
+static int
+ip6_copyexthdr(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(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(struct mbuf *m0, struct mbuf *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(struct route_in6 *ro_pmtu, struct route_in6 *ro,
+    struct ifnet *ifp, struct in6_addr *dst, u_long *mtup,
+    int *alwaysfragp)
+{
+	u_int32_t mtu = 0;
+	int alwaysfrag = 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;
+
+			rtalloc((struct route *)ro_pmtu);
+		}
+	}
+	if (ro_pmtu->ro_rt) {
+		u_int32_t ifmtu;
+		struct in_conninfo inc;
+
+		bzero(&inc, sizeof(inc));
+		inc.inc_flags |= INC_ISIPV6;
+		inc.inc6_faddr = *dst;
+
+		if (ifp == NULL)
+			ifp = ro_pmtu->ro_rt->rt_ifp;
+		ifmtu = IN6_LINKMTU(ifp);
+		mtu = tcp_hc_getmtu(&inc);
+		if (mtu)
+			mtu = min(mtu, ro_pmtu->ro_rt->rt_rmx.rmx_mtu);
+		else
+			mtu = ro_pmtu->ro_rt->rt_rmx.rmx_mtu;
+		if (mtu == 0)
+			mtu = ifmtu;
+		else if (mtu < IPV6_MMTU) {
+			/*
+			 * RFC2460 section 5, last paragraph:
+			 * if we record ICMPv6 too big message with
+			 * mtu < IPV6_MMTU, transmit packets sized IPV6_MMTU
+			 * or smaller, with framgent header attached.
+			 * (fragment header is needed regardless from the
+			 * packet size, for translators to identify packets)
+			 */
+			alwaysfrag = 1;
+			mtu = IPV6_MMTU;
+		} else if (mtu > ifmtu) {
+			/*
+			 * 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).
+			 */
+			mtu = ifmtu;
+			ro_pmtu->ro_rt->rt_rmx.rmx_mtu = mtu;
+		}
+	} else if (ifp) {
+		mtu = IN6_LINKMTU(ifp);
+	} else
+		error = EHOSTUNREACH; /* XXX */
+
+	*mtup = mtu;
+	if (alwaysfragp)
+		*alwaysfragp = alwaysfrag;
+	return (error);
+}
+
+/*
+ * IP6 socket option processing.
+ */
+int
+ip6_ctloutput(struct socket *so, struct sockopt *sopt)
+{
+	int optdatalen, uproto;
+	void *optdata;
+	struct inpcb *in6p = sotoinpcb(so);
+	int error, optval;
+	int level, op, optname;
+	int optlen;
+	struct thread *td;
+
+	level = sopt->sopt_level;
+	op = sopt->sopt_dir;
+	optname = sopt->sopt_name;
+	optlen = sopt->sopt_valsize;
+	td = sopt->sopt_td;
+	error = 0;
+	optval = 0;
+	uproto = (int)so->so_proto->pr_protocol;
+
+	if (level == IPPROTO_IPV6) {
+		switch (op) {
+
+		case SOPT_SET:
+			switch (optname) {
+			case IPV6_2292PKTOPTIONS:
+#ifdef IPV6_PKTOPTIONS
+			case IPV6_PKTOPTIONS:
+#endif
+			{
+				struct mbuf *m;
+
+				error = soopt_getm(sopt, &m); /* XXX */
+				if (error != 0)
+					break;
+				error = soopt_mcopyin(sopt, m); /* XXX */
+				if (error != 0)
+					break;
+				error = ip6_pcbopts(&in6p->in6p_outputopts,
+						    m, so, sopt);
+				m_freem(m); /* XXX */
+				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:
+				if (td != NULL) {
+					error = priv_check(td,
+					    PRIV_NETINET_SETHDROPTS);
+					if (error)
+						break;
+				}
+				/* FALLTHROUGH */
+			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:
+			case IPV6_BINDANY:
+				if (optname == IPV6_BINDANY && td != NULL) {
+					error = priv_check(td,
+					    PRIV_NETINET_BINDANY);
+					if (error)
+						break;
+				}
+
+				if (optlen != sizeof(int)) {
+					error = EINVAL;
+					break;
+				}
+				error = sooptcopyin(sopt, &optval,
+					sizeof optval, sizeof optval);
+				if (error)
+					break;
+				switch (optname) {
+
+				case IPV6_UNICAST_HOPS:
+					if (optval < -1 || optval >= 256)
+						error = EINVAL;
+					else {
+						/* -1 = kernel default */
+						in6p->in6p_hops = optval;
+						if ((in6p->inp_vflag &
+						     INP_IPV4) != 0)
+							in6p->inp_ip_ttl = optval;
+					}
+					break;
+#define OPTSET(bit) \
+do { \
+	if (optval) \
+		in6p->inp_flags |= (bit); \
+	else \
+		in6p->inp_flags &= ~(bit); \
+} while (/*CONSTCOND*/ 0)
+#define OPTSET2292(bit) \
+do { \
+	in6p->inp_flags |= IN6P_RFC2292; \
+	if (optval) \
+		in6p->inp_flags |= (bit); \
+	else \
+		in6p->inp_flags &= ~(bit); \
+} while (/*CONSTCOND*/ 0)
+#define OPTBIT(bit) (in6p->inp_flags & (bit) ? 1 : 0)
+
+				case IPV6_RECVPKTINFO:
+					/* cannot mix with RFC2292 */
+					if (OPTBIT(IN6P_RFC2292)) {
+						error = EINVAL;
+						break;
+					}
+					OPTSET(IN6P_PKTINFO);
+					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, (td != NULL) ? td->td_ucred :
+					    NULL, uproto);
+					break;
+				}
+
+				case IPV6_RECVHOPLIMIT:
+					/* cannot mix with RFC2292 */
+					if (OPTBIT(IN6P_RFC2292)) {
+						error = EINVAL;
+						break;
+					}
+					OPTSET(IN6P_HOPLIMIT);
+					break;
+
+				case IPV6_RECVHOPOPTS:
+					/* cannot mix with RFC2292 */
+					if (OPTBIT(IN6P_RFC2292)) {
+						error = EINVAL;
+						break;
+					}
+					OPTSET(IN6P_HOPOPTS);
+					break;
+
+				case IPV6_RECVDSTOPTS:
+					/* cannot mix with RFC2292 */
+					if (OPTBIT(IN6P_RFC2292)) {
+						error = EINVAL;
+						break;
+					}
+					OPTSET(IN6P_DSTOPTS);
+					break;
+
+				case IPV6_RECVRTHDRDSTOPTS:
+					/* cannot mix with RFC2292 */
+					if (OPTBIT(IN6P_RFC2292)) {
+						error = EINVAL;
+						break;
+					}
+					OPTSET(IN6P_RTHDRDSTOPTS);
+					break;
+
+				case IPV6_RECVRTHDR:
+					/* cannot mix with RFC2292 */
+					if (OPTBIT(IN6P_RFC2292)) {
+						error = EINVAL;
+						break;
+					}
+					OPTSET(IN6P_RTHDR);
+					break;
+
+				case IPV6_FAITH:
+					OPTSET(INP_FAITH);
+					break;
+
+				case IPV6_RECVPATHMTU:
+					/*
+					 * We ignore this option for TCP
+					 * sockets.
+					 * (RFC3542 leaves this case
+					 * unspecified.)
+					 */
+					if (uproto != IPPROTO_TCP)
+						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->inp_lport ||
+					    !IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
+						error = EINVAL;
+						break;
+					}
+					OPTSET(IN6P_IPV6_V6ONLY);
+					if (optval)
+						in6p->inp_vflag &= ~INP_IPV4;
+					else
+						in6p->inp_vflag |= INP_IPV4;
+					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;
+
+				case IPV6_BINDANY:
+					OPTSET(INP_BINDANY);
+					break;
+				}
+				break;
+
+			case IPV6_TCLASS:
+			case IPV6_DONTFRAG:
+			case IPV6_USE_MIN_MTU:
+			case IPV6_PREFER_TEMPADDR:
+				if (optlen != sizeof(optval)) {
+					error = EINVAL;
+					break;
+				}
+				error = sooptcopyin(sopt, &optval,
+					sizeof optval, sizeof optval);
+				if (error)
+					break;
+				{
+					struct ip6_pktopts **optp;
+					optp = &in6p->in6p_outputopts;
+					error = ip6_pcbopt(optname,
+					    (u_char *)&optval, sizeof(optval),
+					    optp, (td != NULL) ? td->td_ucred :
+					    NULL, uproto);
+					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;
+				}
+				error = sooptcopyin(sopt, &optval,
+					sizeof optval, sizeof optval);
+				if (error)
+					break;
+				switch (optname) {
+				case IPV6_2292PKTINFO:
+					OPTSET2292(IN6P_PKTINFO);
+					break;
+				case IPV6_2292HOPLIMIT:
+					OPTSET2292(IN6P_HOPLIMIT);
+					break;
+				case IPV6_2292HOPOPTS:
+					/*
+					 * Check super-user privilege.
+					 * See comments for IPV6_RECVHOPOPTS.
+					 */
+					if (td != NULL) {
+						error = priv_check(td,
+						    PRIV_NETINET_SETHDROPTS);
+						if (error)
+							return (error);
+					}
+					OPTSET2292(IN6P_HOPOPTS);
+					break;
+				case IPV6_2292DSTOPTS:
+					if (td != NULL) {
+						error = priv_check(td,
+						    PRIV_NETINET_SETHDROPTS);
+						if (error)
+							return (error);
+					}
+					OPTSET2292(IN6P_DSTOPTS|IN6P_RTHDRDSTOPTS); /* XXX */
+					break;
+				case IPV6_2292RTHDR:
+					OPTSET2292(IN6P_RTHDR);
+					break;
+				}
+				break;
+			case IPV6_PKTINFO:
+			case IPV6_HOPOPTS:
+			case IPV6_RTHDR:
+			case IPV6_DSTOPTS:
+			case IPV6_RTHDRDSTOPTS:
+			case IPV6_NEXTHOP:
+			{
+				/* new advanced API (RFC3542) */
+				u_char *optbuf;
+				u_char optbuf_storage[MCLBYTES];
+				int optlen;
+				struct ip6_pktopts **optp;
+
+				/* cannot mix with RFC2292 */
+				if (OPTBIT(IN6P_RFC2292)) {
+					error = EINVAL;
+					break;
+				}
+
+				/*
+				 * We only ensure valsize is not too large
+				 * here.  Further validation will be done
+				 * later.
+				 */
+				error = sooptcopyin(sopt, optbuf_storage,
+				    sizeof(optbuf_storage), 0);
+				if (error)
+					break;
+				optlen = sopt->sopt_valsize;
+				optbuf = optbuf_storage;
+				optp = &in6p->in6p_outputopts;
+				error = ip6_pcbopt(optname, optbuf, optlen,
+				    optp, (td != NULL) ? td->td_ucred : NULL,
+				    uproto);
+				break;
+			}
+#undef OPTSET
+
+			case IPV6_MULTICAST_IF:
+			case IPV6_MULTICAST_HOPS:
+			case IPV6_MULTICAST_LOOP:
+			case IPV6_JOIN_GROUP:
+			case IPV6_LEAVE_GROUP:
+			case IPV6_MSFILTER:
+			case MCAST_BLOCK_SOURCE:
+			case MCAST_UNBLOCK_SOURCE:
+			case MCAST_JOIN_GROUP:
+			case MCAST_LEAVE_GROUP:
+			case MCAST_JOIN_SOURCE_GROUP:
+			case MCAST_LEAVE_SOURCE_GROUP:
+				error = ip6_setmoptions(in6p, sopt);
+				break;
+
+			case IPV6_PORTRANGE:
+				error = sooptcopyin(sopt, &optval,
+				    sizeof optval, sizeof optval);
+				if (error)
+					break;
+
+				switch (optval) {
+				case IPV6_PORTRANGE_DEFAULT:
+					in6p->inp_flags &= ~(INP_LOWPORT);
+					in6p->inp_flags &= ~(INP_HIGHPORT);
+					break;
+
+				case IPV6_PORTRANGE_HIGH:
+					in6p->inp_flags &= ~(INP_LOWPORT);
+					in6p->inp_flags |= INP_HIGHPORT;
+					break;
+
+				case IPV6_PORTRANGE_LOW:
+					in6p->inp_flags &= ~(INP_HIGHPORT);
+					in6p->inp_flags |= INP_LOWPORT;
+					break;
+
+				default:
+					error = EINVAL;
+					break;
+				}
+				break;
+
+#ifdef IPSEC
+			case IPV6_IPSEC_POLICY:
+			{
+				caddr_t req;
+				struct mbuf *m;
+
+				if ((error = soopt_getm(sopt, &m)) != 0) /* XXX */
+					break;
+				if ((error = soopt_mcopyin(sopt, m)) != 0) /* XXX */
+					break;
+				req = mtod(m, caddr_t);
+				error = ipsec_set_policy(in6p, optname, req,
+				    m->m_len, (sopt->sopt_td != NULL) ?
+				    sopt->sopt_td->td_ucred : NULL);
+				m_freem(m);
+				break;
+			}
+#endif /* IPSEC */
+
+			default:
+				error = ENOPROTOOPT;
+				break;
+			}
+			break;
+
+		case SOPT_GET:
+			switch (optname) {
+
+			case IPV6_2292PKTOPTIONS:
+#ifdef IPV6_PKTOPTIONS
+			case IPV6_PKTOPTIONS:
+#endif
+				/*
+				 * RFC3542 (effectively) deprecated the
+				 * semantics of the 2292-style pktoptions.
+				 * Since it was not reliable in nature (i.e.,
+				 * applications had to expect the lack of some
+				 * information after all), it would make sense
+				 * to simplify this part by always returning
+				 * empty data.
+				 */
+				sopt->sopt_valsize = 0;
+				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_RECVPATHMTU:
+
+			case IPV6_FAITH:
+			case IPV6_V6ONLY:
+			case IPV6_PORTRANGE:
+			case IPV6_RECVTCLASS:
+			case IPV6_AUTOFLOWLABEL:
+			case IPV6_BINDANY:
+				switch (optname) {
+
+				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_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_RECVRTHDR:
+					optval = OPTBIT(IN6P_RTHDR);
+					break;
+
+				case IPV6_RECVPATHMTU:
+					optval = OPTBIT(IN6P_MTU);
+					break;
+
+				case IPV6_FAITH:
+					optval = OPTBIT(INP_FAITH);
+					break;
+
+				case IPV6_V6ONLY:
+					optval = OPTBIT(IN6P_IPV6_V6ONLY);
+					break;
+
+				case IPV6_PORTRANGE:
+				    {
+					int flags;
+					flags = in6p->inp_flags;
+					if (flags & INP_HIGHPORT)
+						optval = IPV6_PORTRANGE_HIGH;
+					else if (flags & INP_LOWPORT)
+						optval = IPV6_PORTRANGE_LOW;
+					else
+						optval = 0;
+					break;
+				    }
+				case IPV6_RECVTCLASS:
+					optval = OPTBIT(IN6P_TCLASS);
+					break;
+
+				case IPV6_AUTOFLOWLABEL:
+					optval = OPTBIT(IN6P_AUTOFLOWLABEL);
+					break;
+
+				case IPV6_BINDANY:
+					optval = OPTBIT(INP_BINDANY);
+					break;
+				}
+				if (error)
+					break;
+				error = sooptcopyout(sopt, &optval,
+					sizeof optval);
+				break;
+
+			case IPV6_PATHMTU:
+			{
+				u_long pmtu = 0;
+				struct ip6_mtuinfo mtuinfo;
+				struct route_in6 sro;
+
+				bzero(&sro, sizeof(sro));
+
+				if (!(so->so_state & SS_ISCONNECTED))
+					return (ENOTCONN);
+				/*
+				 * XXX: we dot not consider the case of source
+				 * routing, or optional information to specify
+				 * the outgoing interface.
+				 */
+				error = ip6_getpmtu(&sro, NULL, NULL,
+				    &in6p->in6p_faddr, &pmtu, NULL);
+				if (sro.ro_rt)
+					RTFREE(sro.ro_rt);
+				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);
+				error = sooptcopyout(sopt, optdata,
+				    optdatalen);
+				break;
+			}
+
+			case IPV6_2292PKTINFO:
+			case IPV6_2292HOPLIMIT:
+			case IPV6_2292HOPOPTS:
+			case IPV6_2292RTHDR:
+			case IPV6_2292DSTOPTS:
+				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;
+				}
+				error = sooptcopyout(sopt, &optval,
+				    sizeof optval);
+				break;
+			case IPV6_PKTINFO:
+			case IPV6_HOPOPTS:
+			case IPV6_RTHDR:
+			case IPV6_DSTOPTS:
+			case IPV6_RTHDRDSTOPTS:
+			case IPV6_NEXTHOP:
+			case IPV6_TCLASS:
+			case IPV6_DONTFRAG:
+			case IPV6_USE_MIN_MTU:
+			case IPV6_PREFER_TEMPADDR:
+				error = ip6_getpcbopt(in6p->in6p_outputopts,
+				    optname, sopt);
+				break;
+
+			case IPV6_MULTICAST_IF:
+			case IPV6_MULTICAST_HOPS:
+			case IPV6_MULTICAST_LOOP:
+			case IPV6_MSFILTER:
+				error = ip6_getmoptions(in6p, sopt);
+				break;
+
+#ifdef IPSEC
+			case IPV6_IPSEC_POLICY:
+			  {
+				caddr_t req = NULL;
+				size_t len = 0;
+				struct mbuf *m = NULL;
+				struct mbuf **mp = &m;
+				size_t ovalsize = sopt->sopt_valsize;
+				caddr_t oval = (caddr_t)sopt->sopt_val;
+
+				error = soopt_getm(sopt, &m); /* XXX */
+				if (error != 0)
+					break;
+				error = soopt_mcopyin(sopt, m); /* XXX */
+				if (error != 0)
+					break;
+				sopt->sopt_valsize = ovalsize;
+				sopt->sopt_val = oval;
+				if (m) {
+					req = mtod(m, caddr_t);
+					len = m->m_len;
+				}
+				error = ipsec_get_policy(in6p, req, len, mp);
+				if (error == 0)
+					error = soopt_mcopyout(sopt, m); /* XXX */
+				if (error == 0 && m)
+					m_freem(m);
+				break;
+			  }
+#endif /* IPSEC */
+
+			default:
+				error = ENOPROTOOPT;
+				break;
+			}
+			break;
+		}
+	} else {		/* level != IPPROTO_IPV6 */
+		error = EINVAL;
+	}
+	return (error);
+}
+
+int
+ip6_raw_ctloutput(struct socket *so, struct sockopt *sopt)
+{
+	int error = 0, optval, optlen;
+	const int icmp6off = offsetof(struct icmp6_hdr, icmp6_cksum);
+	struct inpcb *in6p = sotoinpcb(so);
+	int level, op, optname;
+
+	level = sopt->sopt_level;
+	op = sopt->sopt_dir;
+	optname = sopt->sopt_name;
+	optlen = sopt->sopt_valsize;
+
+	if (level != IPPROTO_IPV6) {
+		return (EINVAL);
+	}
+
+	switch (optname) {
+	case IPV6_CHECKSUM:
+		/*
+		 * For ICMPv6 sockets, no modification allowed for checksum
+		 * offset, permit "no change" values to help existing apps.
+		 *
+		 * RFC3542 says: "An attempt to set IPV6_CHECKSUM
+		 * for an ICMPv6 socket will fail."
+		 * The current behavior does not meet RFC3542.
+		 */
+		switch (op) {
+		case SOPT_SET:
+			if (optlen != sizeof(int)) {
+				error = EINVAL;
+				break;
+			}
+			error = sooptcopyin(sopt, &optval, sizeof(optval),
+					    sizeof(optval));
+			if (error)
+				break;
+			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;
+
+		case SOPT_GET:
+			if (so->so_proto->pr_protocol == IPPROTO_ICMPV6)
+				optval = icmp6off;
+			else
+				optval = in6p->in6p_cksum;
+
+			error = sooptcopyout(sopt, &optval, sizeof(optval));
+			break;
+
+		default:
+			error = EINVAL;
+			break;
+		}
+		break;
+
+	default:
+		error = ENOPROTOOPT;
+		break;
+	}
+
+	return (error);
+}
+
+/*
+ * Set up IP6 options in pcb for insertion in output packets or
+ * specifying behavior of outgoing packets.
+ */
+static int
+ip6_pcbopts(struct ip6_pktopts **pktopt, struct mbuf *m,
+    struct socket *so, struct sockopt *sopt)
+{
+	struct ip6_pktopts *opt = *pktopt;
+	int error = 0;
+	struct thread *td = sopt->sopt_td;
+
+	/* 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, regardless of
+		 * whether the opt is just created or given.
+		 */
+		free(opt, M_IP6OPT);
+		return (0);
+	}
+
+	/*  set options specified by user. */
+	if ((error = ip6_setpktopts(m, opt, NULL, (td != NULL) ?
+	    td->td_ucred : NULL, so->so_proto->pr_protocol)) != 0) {
+		ip6_clearpktopts(opt, -1); /* XXX: discard all options */
+		free(opt, M_IP6OPT);
+		return (error);
+	}
+	*pktopt = opt;
+	return (0);
+}
+
+/*
+ * initialize ip6_pktopts.  beware that there are non-zero default values in
+ * the struct.
+ */
+void
+ip6_initpktopts(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 */
+	opt->ip6po_minmtu = IP6PO_MINMTU_MCASTONLY;
+	opt->ip6po_prefer_tempaddr = IP6PO_TEMPADDR_SYSTEM;
+}
+
+static int
+ip6_pcbopt(int optname, u_char *buf, int len, struct ip6_pktopts **pktopt,
+    struct ucred *cred, int uproto)
+{
+	struct ip6_pktopts *opt;
+
+	if (*pktopt == NULL) {
+		*pktopt = malloc(sizeof(struct ip6_pktopts), M_IP6OPT,
+		    M_WAITOK);
+		ip6_initpktopts(*pktopt);
+	}
+	opt = *pktopt;
+
+	return (ip6_setpktopt(optname, buf, len, opt, cred, 1, 0, uproto));
+}
+
+static int
+ip6_getpcbopt(struct ip6_pktopts *pktopt, int optname, struct sockopt *sopt)
+{
+	void *optdata = NULL;
+	int optdatalen = 0;
+	struct ip6_ext *ip6e;
+	int error = 0;
+	struct in6_pktinfo null_pktinfo;
+	int deftclass = 0, on;
+	int defminmtu = IP6PO_MINMTU_MCASTONLY;
+	int defpreftemp = IP6PO_TEMPADDR_SYSTEM;
+
+	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_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;
+	case IPV6_USE_MIN_MTU:
+		if (pktopt)
+			optdata = (void *)&pktopt->ip6po_minmtu;
+		else
+			optdata = (void *)&defminmtu;
+		optdatalen = sizeof(int);
+		break;
+	case IPV6_DONTFRAG:
+		if (pktopt && ((pktopt->ip6po_flags) & IP6PO_DONTFRAG))
+			on = 1;
+		else
+			on = 0;
+		optdata = (void *)&on;
+		optdatalen = sizeof(on);
+		break;
+	case IPV6_PREFER_TEMPADDR:
+		if (pktopt)
+			optdata = (void *)&pktopt->ip6po_prefer_tempaddr;
+		else
+			optdata = (void *)&defpreftemp;
+		optdatalen = sizeof(int);
+		break;
+	default:		/* should not happen */
+#ifdef DIAGNOSTIC
+		panic("ip6_getpcbopt: unexpected option\n");
+#endif
+		return (ENOPROTOOPT);
+	}
+
+	error = sooptcopyout(sopt, optdata, optdatalen);
+
+	return (error);
+}
+
+void
+ip6_clearpktopts(struct ip6_pktopts *pktopt, int optname)
+{
+	if (pktopt == NULL)
+		return;
+
+	if (optname == -1 || optname == IPV6_PKTINFO) {
+		if (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 (pktopt->ip6po_nexthop)
+			free(pktopt->ip6po_nexthop, M_IP6OPT);
+		pktopt->ip6po_nexthop = NULL;
+	}
+	if (optname == -1 || optname == IPV6_HOPOPTS) {
+		if (pktopt->ip6po_hbh)
+			free(pktopt->ip6po_hbh, M_IP6OPT);
+		pktopt->ip6po_hbh = NULL;
+	}
+	if (optname == -1 || optname == IPV6_RTHDRDSTOPTS) {
+		if (pktopt->ip6po_dest1)
+			free(pktopt->ip6po_dest1, M_IP6OPT);
+		pktopt->ip6po_dest1 = NULL;
+	}
+	if (optname == -1 || optname == IPV6_RTHDR) {
+		if (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 (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 (/*CONSTCOND*/ 0)
+
+static int
+copypktopts(struct ip6_pktopts *dst, struct ip6_pktopts *src, int canwait)
+{
+	if (dst == NULL || src == NULL)  {
+		printf("ip6_clearpktopts: invalid argument\n");
+		return (EINVAL);
+	}
+
+	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)
+			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)
+			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 (0);
+
+  bad:
+	ip6_clearpktopts(dst, -1);
+	return (ENOBUFS);
+}
+#undef PKTOPT_EXTHDRCPY
+
+struct ip6_pktopts *
+ip6_copypktopts(struct ip6_pktopts *src, int canwait)
+{
+	int error;
+	struct ip6_pktopts *dst;
+
+	dst = malloc(sizeof(*dst), M_IP6OPT, canwait);
+	if (dst == NULL)
+		return (NULL);
+	ip6_initpktopts(dst);
+
+	if ((error = copypktopts(dst, src, canwait)) != 0) {
+		free(dst, M_IP6OPT);
+		return (NULL);
+	}
+
+	return (dst);
+}
+
+void
+ip6_freepcbopts(struct ip6_pktopts *pktopt)
+{
+	if (pktopt == NULL)
+		return;
+
+	ip6_clearpktopts(pktopt, -1);
+
+	free(pktopt, M_IP6OPT);
+}
+
+/*
+ * Set IPv6 outgoing packet options based on advanced API.
+ */
+int
+ip6_setpktopts(struct mbuf *control, struct ip6_pktopts *opt,
+    struct ip6_pktopts *stickyopt, struct ucred *cred, int uproto)
+{
+	struct cmsghdr *cm = 0;
+
+	if (control == NULL || opt == NULL)
+		return (EINVAL);
+
+	ip6_initpktopts(opt);
+	if (stickyopt) {
+		int error;
+
+		/*
+		 * If stickyopt is provided, make a local copy of the options
+		 * for this particular packet, then override them by ancillary
+		 * objects.
+		 * XXX: copypktopts() does not copy the cached route to a next
+		 * hop (if any).  This is not very good in terms of efficiency,
+		 * but we can allow this since this option should be rarely
+		 * used.
+		 */
+		if ((error = copypktopts(opt, stickyopt, M_NOWAIT)) != 0)
+			return (error);
+	}
+
+	/*
+	 * XXX: Currently, we assume all the optional information is stored
+	 * in a single mbuf.
+	 */
+	if (control->m_next)
+		return (EINVAL);
+
+	for (; control->m_len > 0; 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_setpktopt(cm->cmsg_type, CMSG_DATA(cm),
+		    cm->cmsg_len - CMSG_LEN(0), opt, cred, 0, 1, uproto);
+		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 RFC3542 ancillary data
+ * "sticky=1, cmsg=0": RFC3542 socket option
+ * "sticky=1, cmsg=1": RFC2292 socket option
+ */
+static int
+ip6_setpktopt(int optname, u_char *buf, int len, struct ip6_pktopts *opt,
+    struct ucred *cred, int sticky, int cmsg, int uproto)
+{
+	int minmtupolicy, preftemp;
+	int error;
+
+	if (!sticky && !cmsg) {
+#ifdef DIAGNOSTIC
+		printf("ip6_setpktopt: impossible case\n");
+#endif
+		return (EINVAL);
+	}
+
+	/*
+	 * IPV6_2292xxx is for backward compatibility to RFC2292, and should
+	 * not be specified in the context of RFC3542.  Conversely,
+	 * RFC3542 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_USE_MIN_MTU:
+		case IPV6_DONTFRAG:
+		case IPV6_TCLASS:
+		case IPV6_PREFER_TEMPADDR: /* XXX: not an RFC3542 option */
+			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.
+		 * [RFC 3542, Section 6]
+		 */
+		if (optname == IPV6_PKTINFO && opt->ip6po_pktinfo &&
+		    pktinfo->ipi6_ifindex == 0 &&
+		    IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
+			ip6_clearpktopts(opt, optname);
+			break;
+		}
+
+		if (uproto == IPPROTO_TCP && optname == IPV6_PKTINFO &&
+		    sticky && !IN6_IS_ADDR_UNSPECIFIED(&pktinfo->ipi6_addr)) {
+			return (EINVAL);
+		}
+
+		/* validate the interface index if specified. */
+		if (pktinfo->ipi6_ifindex > V_if_index ||
+		    pktinfo->ipi6_ifindex < 0) {
+			 return (ENXIO);
+		}
+		if (pktinfo->ipi6_ifindex) {
+			ifp = ifnet_byindex(pktinfo->ipi6_ifindex);
+			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 (opt->ip6po_pktinfo == NULL) {
+			opt->ip6po_pktinfo = malloc(sizeof(*pktinfo),
+			    M_IP6OPT, M_NOWAIT);
+			if (opt->ip6po_pktinfo == NULL)
+				return (ENOBUFS);
+		}
+		bcopy(pktinfo, opt->ip6po_pktinfo, sizeof(*pktinfo));
+		break;
+	}
+
+	case IPV6_2292HOPLIMIT:
+	case IPV6_HOPLIMIT:
+	{
+		int *hlimp;
+
+		/*
+		 * RFC 3542 deprecated 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_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 (cred != NULL) {
+			error = priv_check_cred(cred,
+			    PRIV_NETINET_SETHDROPTS, 0);
+			if (error)
+				return (error);
+		}
+
+		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 = sa6_embedscope(sa6, V_ip6_use_defzone))
+			    != 0) {
+				return (error);
+			}
+			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);
+		opt->ip6po_nexthop = malloc(*buf, M_IP6OPT, M_NOWAIT);
+		if (opt->ip6po_nexthop == NULL)
+			return (ENOBUFS);
+		bcopy(buf, opt->ip6po_nexthop, *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 (cred != NULL) {
+			error = priv_check_cred(cred,
+			    PRIV_NETINET_SETHDROPTS, 0);
+			if (error)
+				return (error);
+		}
+
+		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);
+		opt->ip6po_hbh = malloc(hbhlen, M_IP6OPT, M_NOWAIT);
+		if (opt->ip6po_hbh == NULL)
+			return (ENOBUFS);
+		bcopy(hbh, opt->ip6po_hbh, hbhlen);
+
+		break;
+	}
+
+	case IPV6_2292DSTOPTS:
+	case IPV6_DSTOPTS:
+	case IPV6_RTHDRDSTOPTS:
+	{
+		struct ip6_dest *dest, **newdest = NULL;
+		int destlen;
+
+		if (cred != NULL) { /* XXX: see the comment for IPV6_HOPOPTS */
+			error = priv_check_cred(cred,
+			    PRIV_NETINET_SETHDROPTS, 0);
+			if (error)
+				return (error);
+		}
+
+		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.
+			 * RFC3542 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);
+		*newdest = malloc(destlen, M_IP6OPT, M_NOWAIT);
+		if (*newdest == NULL)
+			return (ENOBUFS);
+		bcopy(dest, *newdest, destlen);
+
+		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);
+		opt->ip6po_rthdr = malloc(rthlen, M_IP6OPT, M_NOWAIT);
+		if (opt->ip6po_rthdr == NULL)
+			return (ENOBUFS);
+		bcopy(rth, opt->ip6po_rthdr, rthlen);
+
+		break;
+	}
+
+	case IPV6_USE_MIN_MTU:
+		if (len != sizeof(int))
+			return (EINVAL);
+		minmtupolicy = *(int *)buf;
+		if (minmtupolicy != IP6PO_MINMTU_MCASTONLY &&
+		    minmtupolicy != IP6PO_MINMTU_DISABLE &&
+		    minmtupolicy != IP6PO_MINMTU_ALL) {
+			return (EINVAL);
+		}
+		opt->ip6po_minmtu = minmtupolicy;
+		break;
+
+	case IPV6_DONTFRAG:
+		if (len != sizeof(int))
+			return (EINVAL);
+
+		if (uproto == IPPROTO_TCP || *(int *)buf == 0) {
+			/*
+			 * we ignore this option for TCP sockets.
+			 * (RFC3542 leaves this case unspecified.)
+			 */
+			opt->ip6po_flags &= ~IP6PO_DONTFRAG;
+		} else
+			opt->ip6po_flags |= IP6PO_DONTFRAG;
+		break;
+
+	case IPV6_PREFER_TEMPADDR:
+		if (len != sizeof(int))
+			return (EINVAL);
+		preftemp = *(int *)buf;
+		if (preftemp != IP6PO_TEMPADDR_SYSTEM &&
+		    preftemp != IP6PO_TEMPADDR_NOTPREFER &&
+		    preftemp != IP6PO_TEMPADDR_PREFER) {
+			return (EINVAL);
+		}
+		opt->ip6po_prefer_tempaddr = preftemp;
+		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(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 *);
+	/*
+	 * 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);
+
+	(void)if_simloop(ifp, copym, dst->sin6_family, 0);
+}
+
+/*
+ * Chop IPv6 header off from the payload.
+ */
+static int
+ip6_splithdr(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;
+		}
+		M_MOVE_PKTHDR(mh, m);
+		MH_ALIGN(mh, sizeof(*ip6));
+		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.
+ */
+int
+ip6_optlen(struct inpcb *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
+}