Move files to match FreeBSD layout

1 files changed, 1759 insertions, 0 deletions

diff --git a/freebsd/sys/netinet6/ip6_input.c b/freebsd/sys/netinet6/ip6_input.c
new file mode 100644
index 00000000..323bb2a8
--- /dev/null
+++ b/freebsd/sys/netinet6/ip6_input.c
@@ -0,0 +1,1759 @@
+#include <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_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $
+ */
+
+/*-
+ * Copyright (c) 1982, 1986, 1988, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)ip_input.c	8.2 (Berkeley) 1/4/94
+ */
+
+#include <freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <freebsd/local/opt_inet.h>
+#include <freebsd/local/opt_inet6.h>
+#include <freebsd/local/opt_ipsec.h>
+
+#include <freebsd/sys/param.h>
+#include <freebsd/sys/systm.h>
+#include <freebsd/sys/malloc.h>
+#include <freebsd/sys/mbuf.h>
+#include <freebsd/sys/proc.h>
+#include <freebsd/sys/domain.h>
+#include <freebsd/sys/protosw.h>
+#include <freebsd/sys/socket.h>
+#include <freebsd/sys/socketvar.h>
+#include <freebsd/sys/errno.h>
+#include <freebsd/sys/time.h>
+#include <freebsd/sys/kernel.h>
+#include <freebsd/sys/syslog.h>
+
+#include <freebsd/net/if.h>
+#include <freebsd/net/if_types.h>
+#include <freebsd/net/if_dl.h>
+#include <freebsd/net/route.h>
+#include <freebsd/net/netisr.h>
+#include <freebsd/net/pfil.h>
+#include <freebsd/net/vnet.h>
+
+#include <freebsd/netinet/in.h>
+#include <freebsd/netinet/in_systm.h>
+#include <freebsd/net/if_llatbl.h>
+#ifdef INET
+#include <freebsd/netinet/ip.h>
+#include <freebsd/netinet/ip_icmp.h>
+#endif /* INET */
+#include <freebsd/netinet/ip6.h>
+#include <freebsd/netinet6/in6_var.h>
+#include <freebsd/netinet6/ip6_var.h>
+#include <freebsd/netinet/in_pcb.h>
+#include <freebsd/netinet/icmp6.h>
+#include <freebsd/netinet6/scope6_var.h>
+#include <freebsd/netinet6/in6_ifattach.h>
+#include <freebsd/netinet6/nd6.h>
+
+#ifdef IPSEC
+#include <freebsd/netipsec/ipsec.h>
+#include <freebsd/netinet6/ip6_ipsec.h>
+#include <freebsd/netipsec/ipsec6.h>
+#endif /* IPSEC */
+
+#include <freebsd/netinet6/ip6protosw.h>
+
+extern struct domain inet6domain;
+
+u_char ip6_protox[IPPROTO_MAX];
+VNET_DEFINE(struct in6_ifaddrhead, in6_ifaddrhead);
+
+static struct netisr_handler ip6_nh = {
+	.nh_name = "ip6",
+	.nh_handler = ip6_input,
+	.nh_proto = NETISR_IPV6,
+	.nh_policy = NETISR_POLICY_FLOW,
+};
+
+VNET_DECLARE(struct callout, in6_tmpaddrtimer_ch);
+#define	V_in6_tmpaddrtimer_ch		VNET(in6_tmpaddrtimer_ch)
+
+VNET_DEFINE(struct pfil_head, inet6_pfil_hook);
+
+VNET_DEFINE(struct ip6stat, ip6stat);
+
+struct rwlock in6_ifaddr_lock;
+RW_SYSINIT(in6_ifaddr_lock, &in6_ifaddr_lock, "in6_ifaddr_lock");
+
+static void ip6_init2(void *);
+static struct ip6aux *ip6_setdstifaddr(struct mbuf *, struct in6_ifaddr *);
+static int ip6_hopopts_input(u_int32_t *, u_int32_t *, struct mbuf **, int *);
+#ifdef PULLDOWN_TEST
+static struct mbuf *ip6_pullexthdr(struct mbuf *, size_t, int);
+#endif
+
+/*
+ * IP6 initialization: fill in IP6 protocol switch table.
+ * All protocols not implemented in kernel go to raw IP6 protocol handler.
+ */
+void
+ip6_init(void)
+{
+	struct ip6protosw *pr;
+	int i;
+
+	TUNABLE_INT_FETCH("net.inet6.ip6.auto_linklocal",
+	    &V_ip6_auto_linklocal);
+
+	TAILQ_INIT(&V_in6_ifaddrhead);
+
+	/* Initialize packet filter hooks. */
+	V_inet6_pfil_hook.ph_type = PFIL_TYPE_AF;
+	V_inet6_pfil_hook.ph_af = AF_INET6;
+	if ((i = pfil_head_register(&V_inet6_pfil_hook)) != 0)
+		printf("%s: WARNING: unable to register pfil hook, "
+			"error %d\n", __func__, i);
+
+	scope6_init();
+	addrsel_policy_init();
+	nd6_init();
+	frag6_init();
+
+	V_ip6_desync_factor = arc4random() % MAX_TEMP_DESYNC_FACTOR;
+
+	/* Skip global initialization stuff for non-default instances. */
+	if (!IS_DEFAULT_VNET(curvnet))
+		return;
+
+#ifdef DIAGNOSTIC
+	if (sizeof(struct protosw) != sizeof(struct ip6protosw))
+		panic("sizeof(protosw) != sizeof(ip6protosw)");
+#endif
+	pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
+	if (pr == NULL)
+		panic("ip6_init");
+
+	/* Initialize the entire ip6_protox[] array to IPPROTO_RAW. */
+	for (i = 0; i < IPPROTO_MAX; i++)
+		ip6_protox[i] = pr - inet6sw;
+	/*
+	 * Cycle through IP protocols and put them into the appropriate place
+	 * in ip6_protox[].
+	 */
+	for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
+	    pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++)
+		if (pr->pr_domain->dom_family == PF_INET6 &&
+		    pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
+			/* Be careful to only index valid IP protocols. */
+			if (pr->pr_protocol < IPPROTO_MAX)
+				ip6_protox[pr->pr_protocol] = pr - inet6sw;
+		}
+
+	netisr_register(&ip6_nh);
+}
+
+/*
+ * The protocol to be inserted into ip6_protox[] must be already registered
+ * in inet6sw[], either statically or through pf_proto_register().
+ */
+int
+ip6proto_register(short ip6proto)
+{
+	struct ip6protosw *pr;
+
+	/* Sanity checks. */
+	if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
+		return (EPROTONOSUPPORT);
+
+	/*
+	 * The protocol slot must not be occupied by another protocol
+	 * already.  An index pointing to IPPROTO_RAW is unused.
+	 */
+	pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
+	if (pr == NULL)
+		return (EPFNOSUPPORT);
+	if (ip6_protox[ip6proto] != pr - inet6sw)	/* IPPROTO_RAW */
+		return (EEXIST);
+
+	/*
+	 * Find the protocol position in inet6sw[] and set the index.
+	 */
+	for (pr = (struct ip6protosw *)inet6domain.dom_protosw;
+	    pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) {
+		if (pr->pr_domain->dom_family == PF_INET6 &&
+		    pr->pr_protocol && pr->pr_protocol == ip6proto) {
+			ip6_protox[pr->pr_protocol] = pr - inet6sw;
+			return (0);
+		}
+	}
+	return (EPROTONOSUPPORT);
+}
+
+int
+ip6proto_unregister(short ip6proto)
+{
+	struct ip6protosw *pr;
+
+	/* Sanity checks. */
+	if (ip6proto <= 0 || ip6proto >= IPPROTO_MAX)
+		return (EPROTONOSUPPORT);
+
+	/* Check if the protocol was indeed registered. */
+	pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW);
+	if (pr == NULL)
+		return (EPFNOSUPPORT);
+	if (ip6_protox[ip6proto] == pr - inet6sw)	/* IPPROTO_RAW */
+		return (ENOENT);
+
+	/* Reset the protocol slot to IPPROTO_RAW. */
+	ip6_protox[ip6proto] = pr - inet6sw;
+	return (0);
+}
+
+#ifdef VIMAGE
+void
+ip6_destroy()
+{
+
+	nd6_destroy();
+	callout_drain(&V_in6_tmpaddrtimer_ch);
+}
+#endif
+
+static int
+ip6_init2_vnet(const void *unused __unused)
+{
+
+	/* nd6_timer_init */
+	callout_init(&V_nd6_timer_ch, 0);
+	callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
+
+	/* timer for regeneranation of temporary addresses randomize ID */
+	callout_init(&V_in6_tmpaddrtimer_ch, 0);
+	callout_reset(&V_in6_tmpaddrtimer_ch,
+		      (V_ip6_temp_preferred_lifetime - V_ip6_desync_factor -
+		       V_ip6_temp_regen_advance) * hz,
+		      in6_tmpaddrtimer, curvnet);
+
+	return (0);
+}
+
+static void
+ip6_init2(void *dummy)
+{
+
+	ip6_init2_vnet(NULL);
+}
+
+/* cheat */
+/* This must be after route_init(), which is now SI_ORDER_THIRD */
+SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL);
+
+void
+ip6_input(struct mbuf *m)
+{
+	struct ip6_hdr *ip6;
+	int off = sizeof(struct ip6_hdr), nest;
+	u_int32_t plen;
+	u_int32_t rtalert = ~0;
+	int nxt, ours = 0;
+	struct ifnet *deliverifp = NULL, *ifp = NULL;
+	struct in6_addr odst;
+	struct route_in6 rin6;
+	int srcrt = 0;
+	struct llentry *lle = NULL;
+	struct sockaddr_in6 dst6, *dst;
+
+	bzero(&rin6, sizeof(struct route_in6));
+#ifdef IPSEC
+	/*
+	 * should the inner packet be considered authentic?
+	 * see comment in ah4_input().
+	 * NB: m cannot be NULL when passed to the input routine
+	 */
+
+	m->m_flags &= ~M_AUTHIPHDR;
+	m->m_flags &= ~M_AUTHIPDGM;
+
+#endif /* IPSEC */
+
+	/*
+	 * make sure we don't have onion peering information into m_tag.
+	 */
+	ip6_delaux(m);
+
+	/*
+	 * mbuf statistics
+	 */
+	if (m->m_flags & M_EXT) {
+		if (m->m_next)
+			V_ip6stat.ip6s_mext2m++;
+		else
+			V_ip6stat.ip6s_mext1++;
+	} else {
+#define M2MMAX	(sizeof(V_ip6stat.ip6s_m2m)/sizeof(V_ip6stat.ip6s_m2m[0]))
+		if (m->m_next) {
+			if (m->m_flags & M_LOOP) {
+				V_ip6stat.ip6s_m2m[V_loif->if_index]++;
+			} else if (m->m_pkthdr.rcvif->if_index < M2MMAX)
+				V_ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++;
+			else
+				V_ip6stat.ip6s_m2m[0]++;
+		} else
+			V_ip6stat.ip6s_m1++;
+#undef M2MMAX
+	}
+
+	/* drop the packet if IPv6 operation is disabled on the IF */
+	if ((ND_IFINFO(m->m_pkthdr.rcvif)->flags & ND6_IFF_IFDISABLED)) {
+		m_freem(m);
+		return;
+	}
+
+	in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive);
+	V_ip6stat.ip6s_total++;
+
+#ifndef PULLDOWN_TEST
+	/*
+	 * L2 bridge code and some other code can return mbuf chain
+	 * that does not conform to KAME requirement.  too bad.
+	 * XXX: fails to join if interface MTU > MCLBYTES.  jumbogram?
+	 */
+	if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) {
+		struct mbuf *n;
+
+		MGETHDR(n, M_DONTWAIT, MT_HEADER);
+		if (n)
+			M_MOVE_PKTHDR(n, m);
+		if (n && n->m_pkthdr.len > MHLEN) {
+			MCLGET(n, M_DONTWAIT);
+			if ((n->m_flags & M_EXT) == 0) {
+				m_freem(n);
+				n = NULL;
+			}
+		}
+		if (n == NULL) {
+			m_freem(m);
+			return;	/* ENOBUFS */
+		}
+
+		m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t));
+		n->m_len = n->m_pkthdr.len;
+		m_freem(m);
+		m = n;
+	}
+	IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /* nothing */);
+#endif
+
+	if (m->m_len < sizeof(struct ip6_hdr)) {
+		struct ifnet *inifp;
+		inifp = m->m_pkthdr.rcvif;
+		if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
+			V_ip6stat.ip6s_toosmall++;
+			in6_ifstat_inc(inifp, ifs6_in_hdrerr);
+			return;
+		}
+	}
+
+	ip6 = mtod(m, struct ip6_hdr *);
+
+	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
+		V_ip6stat.ip6s_badvers++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
+		goto bad;
+	}
+
+	V_ip6stat.ip6s_nxthist[ip6->ip6_nxt]++;
+
+	/*
+	 * Check against address spoofing/corruption.
+	 */
+	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) ||
+	    IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) {
+		/*
+		 * XXX: "badscope" is not very suitable for a multicast source.
+		 */
+		V_ip6stat.ip6s_badscope++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		goto bad;
+	}
+	if (IN6_IS_ADDR_MC_INTFACELOCAL(&ip6->ip6_dst) &&
+	    !(m->m_flags & M_LOOP)) {
+		/*
+		 * In this case, the packet should come from the loopback
+		 * interface.  However, we cannot just check the if_flags,
+		 * because ip6_mloopback() passes the "actual" interface
+		 * as the outgoing/incoming interface.
+		 */
+		V_ip6stat.ip6s_badscope++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		goto bad;
+	}
+
+#ifdef ALTQ
+	if (altq_input != NULL && (*altq_input)(m, AF_INET6) == 0) {
+		/* packet is dropped by traffic conditioner */
+		return;
+	}
+#endif
+	/*
+	 * The following check is not documented in specs.  A malicious
+	 * party may be able to use IPv4 mapped addr to confuse tcp/udp stack
+	 * and bypass security checks (act as if it was from 127.0.0.1 by using
+	 * IPv6 src ::ffff:127.0.0.1).  Be cautious.
+	 *
+	 * This check chokes if we are in an SIIT cloud.  As none of BSDs
+	 * support IPv4-less kernel compilation, we cannot support SIIT
+	 * environment at all.  So, it makes more sense for us to reject any
+	 * malicious packets for non-SIIT environment, than try to do a
+	 * partial support for SIIT environment.
+	 */
+	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
+	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
+		V_ip6stat.ip6s_badscope++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		goto bad;
+	}
+#if 0
+	/*
+	 * Reject packets with IPv4 compatible addresses (auto tunnel).
+	 *
+	 * The code forbids auto tunnel relay case in RFC1933 (the check is
+	 * stronger than RFC1933).  We may want to re-enable it if mech-xx
+	 * is revised to forbid relaying case.
+	 */
+	if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) ||
+	    IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) {
+		V_ip6stat.ip6s_badscope++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		goto bad;
+	}
+#endif
+
+	/*
+	 * Run through list of hooks for input packets.
+	 *
+	 * NB: Beware of the destination address changing
+	 *     (e.g. by NAT rewriting).  When this happens,
+	 *     tell ip6_forward to do the right thing.
+	 */
+	odst = ip6->ip6_dst;
+
+	/* Jump over all PFIL processing if hooks are not active. */
+	if (!PFIL_HOOKED(&V_inet6_pfil_hook))
+		goto passin;
+
+	if (pfil_run_hooks(&V_inet6_pfil_hook, &m,
+	    m->m_pkthdr.rcvif, PFIL_IN, NULL))
+		return;
+	if (m == NULL)			/* consumed by filter */
+		return;
+	ip6 = mtod(m, struct ip6_hdr *);
+	srcrt = !IN6_ARE_ADDR_EQUAL(&odst, &ip6->ip6_dst);
+
+passin:
+	/*
+	 * Disambiguate address scope zones (if there is ambiguity).
+	 * We first make sure that the original source or destination address
+	 * is not in our internal form for scoped addresses.  Such addresses
+	 * are not necessarily invalid spec-wise, but we cannot accept them due
+	 * to the usage conflict.
+	 * in6_setscope() then also checks and rejects the cases where src or
+	 * dst are the loopback address and the receiving interface
+	 * is not loopback.
+	 */
+	if (in6_clearscope(&ip6->ip6_src) || in6_clearscope(&ip6->ip6_dst)) {
+		V_ip6stat.ip6s_badscope++; /* XXX */
+		goto bad;
+	}
+	if (in6_setscope(&ip6->ip6_src, m->m_pkthdr.rcvif, NULL) ||
+	    in6_setscope(&ip6->ip6_dst, m->m_pkthdr.rcvif, NULL)) {
+		V_ip6stat.ip6s_badscope++;
+		goto bad;
+	}
+
+	/*
+	 * Multicast check. Assume packet is for us to avoid
+	 * prematurely taking locks.
+	 */
+	if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+		ours = 1;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast);
+		deliverifp = m->m_pkthdr.rcvif;
+		goto hbhcheck;
+	}
+
+	/*
+	 *  Unicast check
+	 */
+
+	bzero(&dst6, sizeof(dst6));
+	dst6.sin6_family = AF_INET6;
+	dst6.sin6_len = sizeof(struct sockaddr_in6);
+	dst6.sin6_addr = ip6->ip6_dst;
+	ifp = m->m_pkthdr.rcvif;
+	IF_AFDATA_LOCK(ifp);
+	lle = lla_lookup(LLTABLE6(ifp), 0,
+	     (struct sockaddr *)&dst6);
+	IF_AFDATA_UNLOCK(ifp);
+	if ((lle != NULL) && (lle->la_flags & LLE_IFADDR)) {
+		struct ifaddr *ifa;
+		struct in6_ifaddr *ia6;
+		int bad;
+
+		bad = 1;
+#define	sa_equal(a1, a2)						\
+	(bcmp((a1), (a2), ((a1))->sin6_len) == 0)
+		IF_ADDR_LOCK(ifp);
+		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
+			if (ifa->ifa_addr->sa_family != dst6.sin6_family)
+				continue;
+			if (sa_equal(&dst6, ifa->ifa_addr))
+				break;
+		}
+		KASSERT(ifa != NULL, ("%s: ifa not found for lle %p",
+		    __func__, lle));
+#undef sa_equal
+
+		ia6 = (struct in6_ifaddr *)ifa;
+		if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
+			/* Count the packet in the ip address stats */
+			ia6->ia_ifa.if_ipackets++;
+			ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
+
+			/*
+			 * record address information into m_tag.
+			 */
+			(void)ip6_setdstifaddr(m, ia6);
+
+			bad = 0;
+		} else {
+			char ip6bufs[INET6_ADDRSTRLEN];
+			char ip6bufd[INET6_ADDRSTRLEN];
+			/* address is not ready, so discard the packet. */
+			nd6log((LOG_INFO,
+			    "ip6_input: packet to an unready address %s->%s\n",
+			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
+			    ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
+		}
+		IF_ADDR_UNLOCK(ifp);
+		LLE_RUNLOCK(lle);
+		if (bad)
+			goto bad;
+		else {
+			ours = 1;
+			deliverifp = ifp;
+			goto hbhcheck;
+		}
+	}
+	if (lle != NULL)
+		LLE_RUNLOCK(lle);
+
+	dst = &rin6.ro_dst;
+	dst->sin6_len = sizeof(struct sockaddr_in6);
+	dst->sin6_family = AF_INET6;
+	dst->sin6_addr = ip6->ip6_dst;
+	rin6.ro_rt = rtalloc1((struct sockaddr *)dst, 0, 0);
+	if (rin6.ro_rt)
+		RT_UNLOCK(rin6.ro_rt);
+
+#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key))
+
+	/*
+	 * Accept the packet if the forwarding interface to the destination
+	 * according to the routing table is the loopback interface,
+	 * unless the associated route has a gateway.
+	 * Note that this approach causes to accept a packet if there is a
+	 * route to the loopback interface for the destination of the packet.
+	 * But we think it's even useful in some situations, e.g. when using
+	 * a special daemon which wants to intercept the packet.
+	 *
+	 * XXX: some OSes automatically make a cloned route for the destination
+	 * of an outgoing packet.  If the outgoing interface of the packet
+	 * is a loopback one, the kernel would consider the packet to be
+	 * accepted, even if we have no such address assinged on the interface.
+	 * We check the cloned flag of the route entry to reject such cases,
+	 * assuming that route entries for our own addresses are not made by
+	 * cloning (it should be true because in6_addloop explicitly installs
+	 * the host route).  However, we might have to do an explicit check
+	 * while it would be less efficient.  Or, should we rather install a
+	 * reject route for such a case?
+	 */
+	if (rin6.ro_rt &&
+	    (rin6.ro_rt->rt_flags &
+	     (RTF_HOST|RTF_GATEWAY)) == RTF_HOST &&
+#ifdef RTF_WASCLONED
+	    !(rin6.ro_rt->rt_flags & RTF_WASCLONED) &&
+#endif
+#ifdef RTF_CLONED
+	    !(rin6.ro_rt->rt_flags & RTF_CLONED) &&
+#endif
+#if 0
+	    /*
+	     * The check below is redundant since the comparison of
+	     * the destination and the key of the rtentry has
+	     * already done through looking up the routing table.
+	     */
+	    IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst,
+	    &rt6_key(rin6.ro_rt)->sin6_addr)
+#endif
+	    rin6.ro_rt->rt_ifp->if_type == IFT_LOOP) {
+		int free_ia6 = 0;
+		struct in6_ifaddr *ia6;
+
+		/*
+		 * found the loopback route to the interface address
+		 */
+		if (rin6.ro_rt->rt_gateway->sa_family == AF_LINK) {
+			struct sockaddr_in6 dest6;
+
+			bzero(&dest6, sizeof(dest6));
+			dest6.sin6_family = AF_INET6;
+			dest6.sin6_len = sizeof(dest6);
+			dest6.sin6_addr = ip6->ip6_dst;
+			ia6 = (struct in6_ifaddr *)
+			    ifa_ifwithaddr((struct sockaddr *)&dest6);
+			if (ia6 == NULL)
+				goto bad;
+			free_ia6 = 1;
+		}
+		else
+			ia6 = (struct in6_ifaddr *)rin6.ro_rt->rt_ifa;
+
+		/*
+		 * record address information into m_tag.
+		 */
+		(void)ip6_setdstifaddr(m, ia6);
+
+		/*
+		 * packets to a tentative, duplicated, or somehow invalid
+		 * address must not be accepted.
+		 */
+		if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) {
+			/* this address is ready */
+			ours = 1;
+			deliverifp = ia6->ia_ifp;	/* correct? */
+			/* Count the packet in the ip address stats */
+			ia6->ia_ifa.if_ipackets++;
+			ia6->ia_ifa.if_ibytes += m->m_pkthdr.len;
+			if (ia6 != NULL && free_ia6 != 0)
+				ifa_free(&ia6->ia_ifa);
+			goto hbhcheck;
+		} else {
+			char ip6bufs[INET6_ADDRSTRLEN];
+			char ip6bufd[INET6_ADDRSTRLEN];
+			/* address is not ready, so discard the packet. */
+			nd6log((LOG_INFO,
+			    "ip6_input: packet to an unready address %s->%s\n",
+			    ip6_sprintf(ip6bufs, &ip6->ip6_src),
+			    ip6_sprintf(ip6bufd, &ip6->ip6_dst)));
+
+			if (ia6 != NULL && free_ia6 != 0)
+				ifa_free(&ia6->ia_ifa);
+			goto bad;
+		}
+	}
+
+	/*
+	 * FAITH (Firewall Aided Internet Translator)
+	 */
+	if (V_ip6_keepfaith) {
+		if (rin6.ro_rt && rin6.ro_rt->rt_ifp &&
+		    rin6.ro_rt->rt_ifp->if_type == IFT_FAITH) {
+			/* XXX do we need more sanity checks? */
+			ours = 1;
+			deliverifp = rin6.ro_rt->rt_ifp; /* faith */
+			goto hbhcheck;
+		}
+	}
+
+	/*
+	 * Now there is no reason to process the packet if it's not our own
+	 * and we're not a router.
+	 */
+	if (!V_ip6_forwarding) {
+		V_ip6stat.ip6s_cantforward++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+		goto bad;
+	}
+
+  hbhcheck:
+	/*
+	 * record address information into m_tag, if we don't have one yet.
+	 * note that we are unable to record it, if the address is not listed
+	 * as our interface address (e.g. multicast addresses, addresses
+	 * within FAITH prefixes and such).
+	 */
+	if (deliverifp && !ip6_getdstifaddr(m)) {
+		struct in6_ifaddr *ia6;
+
+		ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst);
+		if (ia6) {
+			if (!ip6_setdstifaddr(m, ia6)) {
+				/*
+				 * XXX maybe we should drop the packet here,
+				 * as we could not provide enough information
+				 * to the upper layers.
+				 */
+			}
+			ifa_free(&ia6->ia_ifa);
+		}
+	}
+
+	/*
+	 * Process Hop-by-Hop options header if it's contained.
+	 * m may be modified in ip6_hopopts_input().
+	 * If a JumboPayload option is included, plen will also be modified.
+	 */
+	plen = (u_int32_t)ntohs(ip6->ip6_plen);
+	if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
+		struct ip6_hbh *hbh;
+
+		if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) {
+#if 0	/*touches NULL pointer*/
+			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+#endif
+			goto out;	/* m have already been freed */
+		}
+
+		/* adjust pointer */
+		ip6 = mtod(m, struct ip6_hdr *);
+
+		/*
+		 * if the payload length field is 0 and the next header field
+		 * indicates Hop-by-Hop Options header, then a Jumbo Payload
+		 * option MUST be included.
+		 */
+		if (ip6->ip6_plen == 0 && plen == 0) {
+			/*
+			 * Note that if a valid jumbo payload option is
+			 * contained, ip6_hopopts_input() must set a valid
+			 * (non-zero) payload length to the variable plen.
+			 */
+			V_ip6stat.ip6s_badoptions++;
+			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr);
+			icmp6_error(m, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_HEADER,
+				    (caddr_t)&ip6->ip6_plen - (caddr_t)ip6);
+			goto out;
+		}
+#ifndef PULLDOWN_TEST
+		/* ip6_hopopts_input() ensures that mbuf is contiguous */
+		hbh = (struct ip6_hbh *)(ip6 + 1);
+#else
+		IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
+			sizeof(struct ip6_hbh));
+		if (hbh == NULL) {
+			V_ip6stat.ip6s_tooshort++;
+			goto out;
+		}
+#endif
+		nxt = hbh->ip6h_nxt;
+
+		/*
+		 * If we are acting as a router and the packet contains a
+		 * router alert option, see if we know the option value.
+		 * Currently, we only support the option value for MLD, in which
+		 * case we should pass the packet to the multicast routing
+		 * daemon.
+		 */
+		if (rtalert != ~0) {
+			switch (rtalert) {
+			case IP6OPT_RTALERT_MLD:
+				if (V_ip6_forwarding)
+					ours = 1;
+				break;
+			default:
+				/*
+				 * RFC2711 requires unrecognized values must be
+				 * silently ignored.
+				 */
+				break;
+			}
+		}
+	} else
+		nxt = ip6->ip6_nxt;
+
+	/*
+	 * Check that the amount of data in the buffers
+	 * is as at least much as the IPv6 header would have us expect.
+	 * Trim mbufs if longer than we expect.
+	 * Drop packet if shorter than we expect.
+	 */
+	if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) {
+		V_ip6stat.ip6s_tooshort++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
+		goto bad;
+	}
+	if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) {
+		if (m->m_len == m->m_pkthdr.len) {
+			m->m_len = sizeof(struct ip6_hdr) + plen;
+			m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen;
+		} else
+			m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len);
+	}
+
+	/*
+	 * Forward if desirable.
+	 */
+	if (V_ip6_mrouter &&
+	    IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
+		/*
+		 * If we are acting as a multicast router, all
+		 * incoming multicast packets are passed to the
+		 * kernel-level multicast forwarding function.
+		 * The packet is returned (relatively) intact; if
+		 * ip6_mforward() returns a non-zero value, the packet
+		 * must be discarded, else it may be accepted below.
+		 *
+		 * XXX TODO: Check hlim and multicast scope here to avoid
+		 * unnecessarily calling into ip6_mforward().
+		 */
+		if (ip6_mforward &&
+		    ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) {
+			IP6STAT_INC(ip6s_cantforward);
+			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard);
+			goto bad;
+		}
+	} else if (!ours) {
+		ip6_forward(m, srcrt);
+		goto out;
+	}
+
+	ip6 = mtod(m, struct ip6_hdr *);
+
+	/*
+	 * Malicious party may be able to use IPv4 mapped addr to confuse
+	 * tcp/udp stack and bypass security checks (act as if it was from
+	 * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1).  Be cautious.
+	 *
+	 * For SIIT end node behavior, you may want to disable the check.
+	 * However, you will  become vulnerable to attacks using IPv4 mapped
+	 * source.
+	 */
+	if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) ||
+	    IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) {
+		V_ip6stat.ip6s_badscope++;
+		in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr);
+		goto bad;
+	}
+
+	/*
+	 * Tell launch routine the next header
+	 */
+	V_ip6stat.ip6s_delivered++;
+	in6_ifstat_inc(deliverifp, ifs6_in_deliver);
+	nest = 0;
+
+	while (nxt != IPPROTO_DONE) {
+		if (V_ip6_hdrnestlimit && (++nest > V_ip6_hdrnestlimit)) {
+			V_ip6stat.ip6s_toomanyhdr++;
+			goto bad;
+		}
+
+		/*
+		 * protection against faulty packet - there should be
+		 * more sanity checks in header chain processing.
+		 */
+		if (m->m_pkthdr.len < off) {
+			V_ip6stat.ip6s_tooshort++;
+			in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated);
+			goto bad;
+		}
+
+#ifdef IPSEC
+		/*
+		 * enforce IPsec policy checking if we are seeing last header.
+		 * note that we do not visit this with protocols with pcb layer
+		 * code - like udp/tcp/raw ip.
+		 */
+		if (ip6_ipsec_input(m, nxt))
+			goto bad;
+#endif /* IPSEC */
+
+		/*
+		 * Use mbuf flags to propagate Router Alert option to
+		 * ICMPv6 layer, as hop-by-hop options have been stripped.
+		 */
+		if (nxt == IPPROTO_ICMPV6 && rtalert != ~0)
+			m->m_flags |= M_RTALERT_MLD;
+
+		nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt);
+	}
+	goto out;
+bad:
+	m_freem(m);
+out:
+	if (rin6.ro_rt)
+		RTFREE(rin6.ro_rt);
+}
+
+/*
+ * set/grab in6_ifaddr correspond to IPv6 destination address.
+ * XXX backward compatibility wrapper
+ *
+ * XXXRW: We should bump the refcount on ia6 before sticking it in the m_tag,
+ * and then bump it when the tag is copied, and release it when the tag is
+ * freed.  Unfortunately, m_tags don't support deep copies (yet), so instead
+ * we just bump the ia refcount when we receive it.  This should be fixed.
+ */
+static struct ip6aux *
+ip6_setdstifaddr(struct mbuf *m, struct in6_ifaddr *ia6)
+{
+	struct ip6aux *ip6a;
+
+	ip6a = ip6_addaux(m);
+	if (ip6a)
+		ip6a->ip6a_dstia6 = ia6;
+	return ip6a;	/* NULL if failed to set */
+}
+
+struct in6_ifaddr *
+ip6_getdstifaddr(struct mbuf *m)
+{
+	struct ip6aux *ip6a;
+	struct in6_ifaddr *ia;
+
+	ip6a = ip6_findaux(m);
+	if (ip6a) {
+		ia = ip6a->ip6a_dstia6;
+		ifa_ref(&ia->ia_ifa);
+		return ia;
+	} else
+		return NULL;
+}
+
+/*
+ * Hop-by-Hop options header processing. If a valid jumbo payload option is
+ * included, the real payload length will be stored in plenp.
+ *
+ * rtalertp - XXX: should be stored more smart way
+ */
+static int
+ip6_hopopts_input(u_int32_t *plenp, u_int32_t *rtalertp,
+    struct mbuf **mp, int *offp)
+{
+	struct mbuf *m = *mp;
+	int off = *offp, hbhlen;
+	struct ip6_hbh *hbh;
+	u_int8_t *opt;
+
+	/* validation of the length of the header */
+#ifndef PULLDOWN_TEST
+	IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1);
+	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
+	hbhlen = (hbh->ip6h_len + 1) << 3;
+
+	IP6_EXTHDR_CHECK(m, off, hbhlen, -1);
+	hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off);
+#else
+	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m,
+		sizeof(struct ip6_hdr), sizeof(struct ip6_hbh));
+	if (hbh == NULL) {
+		V_ip6stat.ip6s_tooshort++;
+		return -1;
+	}
+	hbhlen = (hbh->ip6h_len + 1) << 3;
+	IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr),
+		hbhlen);
+	if (hbh == NULL) {
+		V_ip6stat.ip6s_tooshort++;
+		return -1;
+	}
+#endif
+	off += hbhlen;
+	hbhlen -= sizeof(struct ip6_hbh);
+	opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh);
+
+	if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh),
+				hbhlen, rtalertp, plenp) < 0)
+		return (-1);
+
+	*offp = off;
+	*mp = m;
+	return (0);
+}
+
+/*
+ * Search header for all Hop-by-hop options and process each option.
+ * This function is separate from ip6_hopopts_input() in order to
+ * handle a case where the sending node itself process its hop-by-hop
+ * options header. In such a case, the function is called from ip6_output().
+ *
+ * The function assumes that hbh header is located right after the IPv6 header
+ * (RFC2460 p7), opthead is pointer into data content in m, and opthead to
+ * opthead + hbhlen is located in continuous memory region.
+ */
+int
+ip6_process_hopopts(struct mbuf *m, u_int8_t *opthead, int hbhlen,
+    u_int32_t *rtalertp, u_int32_t *plenp)
+{
+	struct ip6_hdr *ip6;
+	int optlen = 0;
+	u_int8_t *opt = opthead;
+	u_int16_t rtalert_val;
+	u_int32_t jumboplen;
+	const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh);
+
+	for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) {
+		switch (*opt) {
+		case IP6OPT_PAD1:
+			optlen = 1;
+			break;
+		case IP6OPT_PADN:
+			if (hbhlen < IP6OPT_MINLEN) {
+				V_ip6stat.ip6s_toosmall++;
+				goto bad;
+			}
+			optlen = *(opt + 1) + 2;
+			break;
+		case IP6OPT_ROUTER_ALERT:
+			/* XXX may need check for alignment */
+			if (hbhlen < IP6OPT_RTALERT_LEN) {
+				V_ip6stat.ip6s_toosmall++;
+				goto bad;
+			}
+			if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) {
+				/* XXX stat */
+				icmp6_error(m, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_HEADER,
+				    erroff + opt + 1 - opthead);
+				return (-1);
+			}
+			optlen = IP6OPT_RTALERT_LEN;
+			bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2);
+			*rtalertp = ntohs(rtalert_val);
+			break;
+		case IP6OPT_JUMBO:
+			/* XXX may need check for alignment */
+			if (hbhlen < IP6OPT_JUMBO_LEN) {
+				V_ip6stat.ip6s_toosmall++;
+				goto bad;
+			}
+			if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) {
+				/* XXX stat */
+				icmp6_error(m, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_HEADER,
+				    erroff + opt + 1 - opthead);
+				return (-1);
+			}
+			optlen = IP6OPT_JUMBO_LEN;
+
+			/*
+			 * IPv6 packets that have non 0 payload length
+			 * must not contain a jumbo payload option.
+			 */
+			ip6 = mtod(m, struct ip6_hdr *);
+			if (ip6->ip6_plen) {
+				V_ip6stat.ip6s_badoptions++;
+				icmp6_error(m, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_HEADER,
+				    erroff + opt - opthead);
+				return (-1);
+			}
+
+			/*
+			 * We may see jumbolen in unaligned location, so
+			 * we'd need to perform bcopy().
+			 */
+			bcopy(opt + 2, &jumboplen, sizeof(jumboplen));
+			jumboplen = (u_int32_t)htonl(jumboplen);
+
+#if 1
+			/*
+			 * if there are multiple jumbo payload options,
+			 * *plenp will be non-zero and the packet will be
+			 * rejected.
+			 * the behavior may need some debate in ipngwg -
+			 * multiple options does not make sense, however,
+			 * there's no explicit mention in specification.
+			 */
+			if (*plenp != 0) {
+				V_ip6stat.ip6s_badoptions++;
+				icmp6_error(m, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_HEADER,
+				    erroff + opt + 2 - opthead);
+				return (-1);
+			}
+#endif
+
+			/*
+			 * jumbo payload length must be larger than 65535.
+			 */
+			if (jumboplen <= IPV6_MAXPACKET) {
+				V_ip6stat.ip6s_badoptions++;
+				icmp6_error(m, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_HEADER,
+				    erroff + opt + 2 - opthead);
+				return (-1);
+			}
+			*plenp = jumboplen;
+
+			break;
+		default:		/* unknown option */
+			if (hbhlen < IP6OPT_MINLEN) {
+				V_ip6stat.ip6s_toosmall++;
+				goto bad;
+			}
+			optlen = ip6_unknown_opt(opt, m,
+			    erroff + opt - opthead);
+			if (optlen == -1)
+				return (-1);
+			optlen += 2;
+			break;
+		}
+	}
+
+	return (0);
+
+  bad:
+	m_freem(m);
+	return (-1);
+}
+
+/*
+ * Unknown option processing.
+ * The third argument `off' is the offset from the IPv6 header to the option,
+ * which is necessary if the IPv6 header the and option header and IPv6 header
+ * is not continuous in order to return an ICMPv6 error.
+ */
+int
+ip6_unknown_opt(u_int8_t *optp, struct mbuf *m, int off)
+{
+	struct ip6_hdr *ip6;
+
+	switch (IP6OPT_TYPE(*optp)) {
+	case IP6OPT_TYPE_SKIP: /* ignore the option */
+		return ((int)*(optp + 1));
+	case IP6OPT_TYPE_DISCARD:	/* silently discard */
+		m_freem(m);
+		return (-1);
+	case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */
+		V_ip6stat.ip6s_badoptions++;
+		icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off);
+		return (-1);
+	case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */
+		V_ip6stat.ip6s_badoptions++;
+		ip6 = mtod(m, struct ip6_hdr *);
+		if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
+		    (m->m_flags & (M_BCAST|M_MCAST)))
+			m_freem(m);
+		else
+			icmp6_error(m, ICMP6_PARAM_PROB,
+				    ICMP6_PARAMPROB_OPTION, off);
+		return (-1);
+	}
+
+	m_freem(m);		/* XXX: NOTREACHED */
+	return (-1);
+}
+
+/*
+ * Create the "control" list for this pcb.
+ * These functions will not modify mbuf chain at all.
+ *
+ * With KAME mbuf chain restriction:
+ * The routine will be called from upper layer handlers like tcp6_input().
+ * Thus the routine assumes that the caller (tcp6_input) have already
+ * called IP6_EXTHDR_CHECK() and all the extension headers are located in the
+ * very first mbuf on the mbuf chain.
+ *
+ * ip6_savecontrol_v4 will handle those options that are possible to be
+ * set on a v4-mapped socket.
+ * ip6_savecontrol will directly call ip6_savecontrol_v4 to handle those
+ * options and handle the v6-only ones itself.
+ */
+struct mbuf **
+ip6_savecontrol_v4(struct inpcb *inp, struct mbuf *m, struct mbuf **mp,
+    int *v4only)
+{
+	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
+
+#ifdef SO_TIMESTAMP
+	if ((inp->inp_socket->so_options & SO_TIMESTAMP) != 0) {
+		struct timeval tv;
+
+		microtime(&tv);
+		*mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
+		    SCM_TIMESTAMP, SOL_SOCKET);
+		if (*mp)
+			mp = &(*mp)->m_next;
+	}
+#endif
+
+	if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
+		if (v4only != NULL)
+			*v4only = 1;
+		return (mp);
+	}
+
+#define IS2292(inp, x, y)	(((inp)->inp_flags & IN6P_RFC2292) ? (x) : (y))
+	/* RFC 2292 sec. 5 */
+	if ((inp->inp_flags & IN6P_PKTINFO) != 0) {
+		struct in6_pktinfo pi6;
+
+		bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr));
+		in6_clearscope(&pi6.ipi6_addr);	/* XXX */
+		pi6.ipi6_ifindex =
+		    (m && m->m_pkthdr.rcvif) ? m->m_pkthdr.rcvif->if_index : 0;
+
+		*mp = sbcreatecontrol((caddr_t) &pi6,
+		    sizeof(struct in6_pktinfo),
+		    IS2292(inp, IPV6_2292PKTINFO, IPV6_PKTINFO), IPPROTO_IPV6);
+		if (*mp)
+			mp = &(*mp)->m_next;
+	}
+
+	if ((inp->inp_flags & IN6P_HOPLIMIT) != 0) {
+		int hlim = ip6->ip6_hlim & 0xff;
+
+		*mp = sbcreatecontrol((caddr_t) &hlim, sizeof(int),
+		    IS2292(inp, IPV6_2292HOPLIMIT, IPV6_HOPLIMIT),
+		    IPPROTO_IPV6);
+		if (*mp)
+			mp = &(*mp)->m_next;
+	}
+
+	if (v4only != NULL)
+		*v4only = 0;
+	return (mp);
+}
+
+void
+ip6_savecontrol(struct inpcb *in6p, struct mbuf *m, struct mbuf **mp)
+{
+	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
+	int v4only = 0;
+
+	mp = ip6_savecontrol_v4(in6p, m, mp, &v4only);
+	if (v4only)
+		return;
+
+	if ((in6p->inp_flags & IN6P_TCLASS) != 0) {
+		u_int32_t flowinfo;
+		int tclass;
+
+		flowinfo = (u_int32_t)ntohl(ip6->ip6_flow & IPV6_FLOWINFO_MASK);
+		flowinfo >>= 20;
+
+		tclass = flowinfo & 0xff;
+		*mp = sbcreatecontrol((caddr_t) &tclass, sizeof(tclass),
+		    IPV6_TCLASS, IPPROTO_IPV6);
+		if (*mp)
+			mp = &(*mp)->m_next;
+	}
+
+	/*
+	 * IPV6_HOPOPTS socket option.  Recall that we required super-user
+	 * privilege for the option (see ip6_ctloutput), but it might be too
+	 * strict, since there might be some hop-by-hop options which can be
+	 * returned to normal user.
+	 * See also RFC 2292 section 6 (or RFC 3542 section 8).
+	 */
+	if ((in6p->inp_flags & IN6P_HOPOPTS) != 0) {
+		/*
+		 * Check if a hop-by-hop options header is contatined in the
+		 * received packet, and if so, store the options as ancillary
+		 * data. Note that a hop-by-hop options header must be
+		 * just after the IPv6 header, which is assured through the
+		 * IPv6 input processing.
+		 */
+		if (ip6->ip6_nxt == IPPROTO_HOPOPTS) {
+			struct ip6_hbh *hbh;
+			int hbhlen = 0;
+#ifdef PULLDOWN_TEST
+			struct mbuf *ext;
+#endif
+
+#ifndef PULLDOWN_TEST
+			hbh = (struct ip6_hbh *)(ip6 + 1);
+			hbhlen = (hbh->ip6h_len + 1) << 3;
+#else
+			ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr),
+			    ip6->ip6_nxt);
+			if (ext == NULL) {
+				V_ip6stat.ip6s_tooshort++;
+				return;
+			}
+			hbh = mtod(ext, struct ip6_hbh *);
+			hbhlen = (hbh->ip6h_len + 1) << 3;
+			if (hbhlen != ext->m_len) {
+				m_freem(ext);
+				V_ip6stat.ip6s_tooshort++;
+				return;
+			}
+#endif
+
+			/*
+			 * XXX: We copy the whole header even if a
+			 * jumbo payload option is included, the option which
+			 * is to be removed before returning according to
+			 * RFC2292.
+			 * Note: this constraint is removed in RFC3542
+			 */
+			*mp = sbcreatecontrol((caddr_t)hbh, hbhlen,
+			    IS2292(in6p, IPV6_2292HOPOPTS, IPV6_HOPOPTS),
+			    IPPROTO_IPV6);
+			if (*mp)
+				mp = &(*mp)->m_next;
+#ifdef PULLDOWN_TEST
+			m_freem(ext);
+#endif
+		}
+	}
+
+	if ((in6p->inp_flags & (IN6P_RTHDR | IN6P_DSTOPTS)) != 0) {
+		int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr);
+
+		/*
+		 * Search for destination options headers or routing
+		 * header(s) through the header chain, and stores each
+		 * header as ancillary data.
+		 * Note that the order of the headers remains in
+		 * the chain of ancillary data.
+		 */
+		while (1) {	/* is explicit loop prevention necessary? */
+			struct ip6_ext *ip6e = NULL;
+			int elen;
+#ifdef PULLDOWN_TEST
+			struct mbuf *ext = NULL;
+#endif
+
+			/*
+			 * if it is not an extension header, don't try to
+			 * pull it from the chain.
+			 */
+			switch (nxt) {
+			case IPPROTO_DSTOPTS:
+			case IPPROTO_ROUTING:
+			case IPPROTO_HOPOPTS:
+			case IPPROTO_AH: /* is it possible? */
+				break;
+			default:
+				goto loopend;
+			}
+
+#ifndef PULLDOWN_TEST
+			if (off + sizeof(*ip6e) > m->m_len)
+				goto loopend;
+			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
+			if (nxt == IPPROTO_AH)
+				elen = (ip6e->ip6e_len + 2) << 2;
+			else
+				elen = (ip6e->ip6e_len + 1) << 3;
+			if (off + elen > m->m_len)
+				goto loopend;
+#else
+			ext = ip6_pullexthdr(m, off, nxt);
+			if (ext == NULL) {
+				V_ip6stat.ip6s_tooshort++;
+				return;
+			}
+			ip6e = mtod(ext, struct ip6_ext *);
+			if (nxt == IPPROTO_AH)
+				elen = (ip6e->ip6e_len + 2) << 2;
+			else
+				elen = (ip6e->ip6e_len + 1) << 3;
+			if (elen != ext->m_len) {
+				m_freem(ext);
+				V_ip6stat.ip6s_tooshort++;
+				return;
+			}
+#endif
+
+			switch (nxt) {
+			case IPPROTO_DSTOPTS:
+				if (!(in6p->inp_flags & IN6P_DSTOPTS))
+					break;
+
+				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
+				    IS2292(in6p,
+					IPV6_2292DSTOPTS, IPV6_DSTOPTS),
+				    IPPROTO_IPV6);
+				if (*mp)
+					mp = &(*mp)->m_next;
+				break;
+			case IPPROTO_ROUTING:
+				if (!in6p->inp_flags & IN6P_RTHDR)
+					break;
+
+				*mp = sbcreatecontrol((caddr_t)ip6e, elen,
+				    IS2292(in6p, IPV6_2292RTHDR, IPV6_RTHDR),
+				    IPPROTO_IPV6);
+				if (*mp)
+					mp = &(*mp)->m_next;
+				break;
+			case IPPROTO_HOPOPTS:
+			case IPPROTO_AH: /* is it possible? */
+				break;
+
+			default:
+				/*
+				 * other cases have been filtered in the above.
+				 * none will visit this case.  here we supply
+				 * the code just in case (nxt overwritten or
+				 * other cases).
+				 */
+#ifdef PULLDOWN_TEST
+				m_freem(ext);
+#endif
+				goto loopend;
+
+			}
+
+			/* proceed with the next header. */
+			off += elen;
+			nxt = ip6e->ip6e_nxt;
+			ip6e = NULL;
+#ifdef PULLDOWN_TEST
+			m_freem(ext);
+			ext = NULL;
+#endif
+		}
+	  loopend:
+		;
+	}
+}
+#undef IS2292
+
+void
+ip6_notify_pmtu(struct inpcb *in6p, struct sockaddr_in6 *dst, u_int32_t *mtu)
+{
+	struct socket *so;
+	struct mbuf *m_mtu;
+	struct ip6_mtuinfo mtuctl;
+
+	so =  in6p->inp_socket;
+
+	if (mtu == NULL)
+		return;
+
+#ifdef DIAGNOSTIC
+	if (so == NULL)		/* I believe this is impossible */
+		panic("ip6_notify_pmtu: socket is NULL");
+#endif
+
+	bzero(&mtuctl, sizeof(mtuctl));	/* zero-clear for safety */
+	mtuctl.ip6m_mtu = *mtu;
+	mtuctl.ip6m_addr = *dst;
+	if (sa6_recoverscope(&mtuctl.ip6m_addr))
+		return;
+
+	if ((m_mtu = sbcreatecontrol((caddr_t)&mtuctl, sizeof(mtuctl),
+	    IPV6_PATHMTU, IPPROTO_IPV6)) == NULL)
+		return;
+
+	if (sbappendaddr(&so->so_rcv, (struct sockaddr *)dst, NULL, m_mtu)
+	    == 0) {
+		m_freem(m_mtu);
+		/* XXX: should count statistics */
+	} else
+		sorwakeup(so);
+
+	return;
+}
+
+#ifdef PULLDOWN_TEST
+/*
+ * pull single extension header from mbuf chain.  returns single mbuf that
+ * contains the result, or NULL on error.
+ */
+static struct mbuf *
+ip6_pullexthdr(struct mbuf *m, size_t off, int nxt)
+{
+	struct ip6_ext ip6e;
+	size_t elen;
+	struct mbuf *n;
+
+#ifdef DIAGNOSTIC
+	switch (nxt) {
+	case IPPROTO_DSTOPTS:
+	case IPPROTO_ROUTING:
+	case IPPROTO_HOPOPTS:
+	case IPPROTO_AH: /* is it possible? */
+		break;
+	default:
+		printf("ip6_pullexthdr: invalid nxt=%d\n", nxt);
+	}
+#endif
+
+	m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
+	if (nxt == IPPROTO_AH)
+		elen = (ip6e.ip6e_len + 2) << 2;
+	else
+		elen = (ip6e.ip6e_len + 1) << 3;
+
+	MGET(n, M_DONTWAIT, MT_DATA);
+	if (n && elen >= MLEN) {
+		MCLGET(n, M_DONTWAIT);
+		if ((n->m_flags & M_EXT) == 0) {
+			m_free(n);
+			n = NULL;
+		}
+	}
+	if (!n)
+		return NULL;
+
+	n->m_len = 0;
+	if (elen >= M_TRAILINGSPACE(n)) {
+		m_free(n);
+		return NULL;
+	}
+
+	m_copydata(m, off, elen, mtod(n, caddr_t));
+	n->m_len = elen;
+	return n;
+}
+#endif
+
+/*
+ * Get pointer to the previous header followed by the header
+ * currently processed.
+ * XXX: This function supposes that
+ *	M includes all headers,
+ *	the next header field and the header length field of each header
+ *	are valid, and
+ *	the sum of each header length equals to OFF.
+ * Because of these assumptions, this function must be called very
+ * carefully. Moreover, it will not be used in the near future when
+ * we develop `neater' mechanism to process extension headers.
+ */
+char *
+ip6_get_prevhdr(struct mbuf *m, int off)
+{
+	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
+
+	if (off == sizeof(struct ip6_hdr))
+		return (&ip6->ip6_nxt);
+	else {
+		int len, nxt;
+		struct ip6_ext *ip6e = NULL;
+
+		nxt = ip6->ip6_nxt;
+		len = sizeof(struct ip6_hdr);
+		while (len < off) {
+			ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len);
+
+			switch (nxt) {
+			case IPPROTO_FRAGMENT:
+				len += sizeof(struct ip6_frag);
+				break;
+			case IPPROTO_AH:
+				len += (ip6e->ip6e_len + 2) << 2;
+				break;
+			default:
+				len += (ip6e->ip6e_len + 1) << 3;
+				break;
+			}
+			nxt = ip6e->ip6e_nxt;
+		}
+		if (ip6e)
+			return (&ip6e->ip6e_nxt);
+		else
+			return NULL;
+	}
+}
+
+/*
+ * get next header offset.  m will be retained.
+ */
+int
+ip6_nexthdr(struct mbuf *m, int off, int proto, int *nxtp)
+{
+	struct ip6_hdr ip6;
+	struct ip6_ext ip6e;
+	struct ip6_frag fh;
+
+	/* just in case */
+	if (m == NULL)
+		panic("ip6_nexthdr: m == NULL");
+	if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off)
+		return -1;
+
+	switch (proto) {
+	case IPPROTO_IPV6:
+		if (m->m_pkthdr.len < off + sizeof(ip6))
+			return -1;
+		m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6);
+		if (nxtp)
+			*nxtp = ip6.ip6_nxt;
+		off += sizeof(ip6);
+		return off;
+
+	case IPPROTO_FRAGMENT:
+		/*
+		 * terminate parsing if it is not the first fragment,
+		 * it does not make sense to parse through it.
+		 */
+		if (m->m_pkthdr.len < off + sizeof(fh))
+			return -1;
+		m_copydata(m, off, sizeof(fh), (caddr_t)&fh);
+		/* IP6F_OFF_MASK = 0xfff8(BigEndian), 0xf8ff(LittleEndian) */
+		if (fh.ip6f_offlg & IP6F_OFF_MASK)
+			return -1;
+		if (nxtp)
+			*nxtp = fh.ip6f_nxt;
+		off += sizeof(struct ip6_frag);
+		return off;
+
+	case IPPROTO_AH:
+		if (m->m_pkthdr.len < off + sizeof(ip6e))
+			return -1;
+		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
+		if (nxtp)
+			*nxtp = ip6e.ip6e_nxt;
+		off += (ip6e.ip6e_len + 2) << 2;
+		return off;
+
+	case IPPROTO_HOPOPTS:
+	case IPPROTO_ROUTING:
+	case IPPROTO_DSTOPTS:
+		if (m->m_pkthdr.len < off + sizeof(ip6e))
+			return -1;
+		m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e);
+		if (nxtp)
+			*nxtp = ip6e.ip6e_nxt;
+		off += (ip6e.ip6e_len + 1) << 3;
+		return off;
+
+	case IPPROTO_NONE:
+	case IPPROTO_ESP:
+	case IPPROTO_IPCOMP:
+		/* give up */
+		return -1;
+
+	default:
+		return -1;
+	}
+
+	return -1;
+}
+
+/*
+ * get offset for the last header in the chain.  m will be kept untainted.
+ */
+int
+ip6_lasthdr(struct mbuf *m, int off, int proto, int *nxtp)
+{
+	int newoff;
+	int nxt;
+
+	if (!nxtp) {
+		nxt = -1;
+		nxtp = &nxt;
+	}
+	while (1) {
+		newoff = ip6_nexthdr(m, off, proto, nxtp);
+		if (newoff < 0)
+			return off;
+		else if (newoff < off)
+			return -1;	/* invalid */
+		else if (newoff == off)
+			return newoff;
+
+		off = newoff;
+		proto = *nxtp;
+	}
+}
+
+struct ip6aux *
+ip6_addaux(struct mbuf *m)
+{
+	struct m_tag *mtag;
+
+	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
+	if (!mtag) {
+		mtag = m_tag_get(PACKET_TAG_IPV6_INPUT, sizeof(struct ip6aux),
+		    M_NOWAIT);
+		if (mtag) {
+			m_tag_prepend(m, mtag);
+			bzero(mtag + 1, sizeof(struct ip6aux));
+		}
+	}
+	return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
+}
+
+struct ip6aux *
+ip6_findaux(struct mbuf *m)
+{
+	struct m_tag *mtag;
+
+	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
+	return mtag ? (struct ip6aux *)(mtag + 1) : NULL;
+}
+
+void
+ip6_delaux(struct mbuf *m)
+{
+	struct m_tag *mtag;
+
+	mtag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL);
+	if (mtag)
+		m_tag_delete(m, mtag);
+}
+
+/*
+ * System control for IP6
+ */
+
+u_char	inet6ctlerrmap[PRC_NCMDS] = {
+	0,		0,		0,		0,
+	0,		EMSGSIZE,	EHOSTDOWN,	EHOSTUNREACH,
+	EHOSTUNREACH,	EHOSTUNREACH,	ECONNREFUSED,	ECONNREFUSED,
+	EMSGSIZE,	EHOSTUNREACH,	0,		0,
+	0,		0,		0,		0,
+	ENOPROTOOPT
+};