bring in KAME IPv6 code, dated 19991208.

replaces NRL IPv6 layer.  reuses NRL pcb layer.  no IPsec-on-v6 support.
see sys/netinet6/{TODO,IMPLEMENTATION} for more details.

GENERIC configuration should work fine as before.  GENERIC.v6 works fine
as well, but you'll need KAME userland tools to play with IPv6 (will be
bringed into soon).

1 files changed, 1801 insertions, 0 deletions

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
new file mode 100644
index 00000000000..1a257abe451
--- /dev/null
+++ b/sys/netinet6/nd6.c
@@ -0,0 +1,1801 @@
+/*	$OpenBSD: nd6.c,v 1.1 1999/12/08 06:50:23 itojun Exp $	*/
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * XXX
+ * KAME 970409 note:
+ * BSD/OS version heavily modifies this code, related to llinfo.
+ * Since we don't have BSD/OS version of net/route.c in our hand,
+ * I left the code mostly as it was in 970310.  -- itojun
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/sockio.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/errno.h>
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+#include <sys/ioctl.h>
+#endif
+#include <sys/syslog.h>
+#include <sys/queue.h>
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/if_types.h>
+#if !(defined(__bsdi__) && _BSDI_VERSION >= 199802)
+#include <net/if_atm.h>
+#endif
+#include <net/route.h>
+
+#include <netinet/in.h>
+#ifndef __NetBSD__
+#include <netinet/if_ether.h>
+#ifdef __FreeBSD__
+#include <netinet/if_fddi.h>
+#endif
+#ifdef __bsdi__
+#include <net/if_fddi.h>
+#endif
+#else /* __NetBSD__ */
+#include <net/if_ether.h>
+#include <netinet/if_inarp.h>
+#include <net/if_fddi.h>
+#endif /* __NetBSD__ */
+#include <netinet6/in6_var.h>
+#include <netinet6/ip6.h>
+#include <netinet6/ip6_var.h>
+#include <netinet6/nd6.h>
+#include <netinet6/in6_prefix.h>
+#include <netinet6/icmp6.h>
+
+#ifndef __bsdi__
+#include "loop.h"
+#endif
+#if defined(__NetBSD__) || defined(__OpenBSD__)
+extern struct ifnet loif[NLOOP];
+#endif
+
+#include <net/net_osdep.h>
+
+#define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
+#define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
+
+#define SIN6(s) ((struct sockaddr_in6 *)s)
+#define SDL(s) ((struct sockaddr_dl *)s)
+
+/* timer values */
+int	nd6_prune	= 1;	/* walk list every 1 seconds */
+int	nd6_delay	= 5;	/* delay first probe time 5 second */
+int	nd6_umaxtries	= 3;	/* maximum unicast query */
+int	nd6_mmaxtries	= 3;	/* maximum multicast query */
+int	nd6_useloopback = 1;	/* use loopback interface for local traffic */
+int	nd6_proxyall	= 0;	/* enable Proxy Neighbor Advertisement */
+
+/* preventing too many loops in ND option parsing */
+int nd6_maxndopt = 10;	/* max # of ND options allowed */
+
+/* for debugging? */
+static int nd6_inuse, nd6_allocated;
+
+struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
+struct nd_ifinfo *nd_ifinfo = NULL;
+struct nd_drhead nd_defrouter = { 0 };
+struct nd_prhead nd_prefix = { 0 };
+
+int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
+#if 0
+extern	int ip6_forwarding;
+#endif
+static struct sockaddr_in6 all1_sa;
+
+static void nd6_slowtimo __P((void *));
+
+void
+nd6_init()
+{
+	static int nd6_init_done = 0;
+	int i;
+
+	if (nd6_init_done) {
+		log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
+		return;
+	}
+
+	all1_sa.sin6_family = AF_INET6;
+	all1_sa.sin6_len = sizeof(struct sockaddr_in6);
+	for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
+		all1_sa.sin6_addr.s6_addr[i] = 0xff;
+
+	nd6_init_done = 1;
+
+	/* start timer */
+	timeout(nd6_slowtimo, (caddr_t)0, ND6_SLOWTIMER_INTERVAL * hz);
+}
+
+void
+nd6_ifattach(ifp)
+	struct ifnet *ifp;
+{
+	static size_t if_indexlim = 8;
+
+	/*
+	 * We have some arrays that should be indexed by if_index.
+	 * since if_index will grow dynamically, they should grow too.
+	 */
+	if (nd_ifinfo == NULL || if_index >= if_indexlim) {
+		size_t n;
+		caddr_t q;
+
+		while (if_index >= if_indexlim)
+			if_indexlim <<= 1;
+
+		/* grow nd_ifinfo */
+		n = if_indexlim * sizeof(struct nd_ifinfo);
+		q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
+		bzero(q, n);
+		if (nd_ifinfo) {
+			bcopy((caddr_t)nd_ifinfo, q, n/2);
+			free((caddr_t)nd_ifinfo, M_IP6NDP);
+		}
+		nd_ifinfo = (struct nd_ifinfo *)q;
+	}
+
+#define ND nd_ifinfo[ifp->if_index]
+	ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
+	ND.chlim = IPV6_DEFHLIM;
+	ND.basereachable = REACHABLE_TIME;
+	ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
+	ND.retrans = RETRANS_TIMER;
+	ND.receivedra = 0;
+	nd6_setmtu(ifp);
+#undef ND
+}
+
+/*
+ * Reset ND level link MTU. This function is called when the physical MTU
+ * changes, which means we might have to adjust the ND level MTU.
+ */
+void
+nd6_setmtu(ifp)
+	struct ifnet *ifp;
+{
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+	struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
+	u_long oldmaxmtu = ndi->maxmtu;
+	u_long oldlinkmtu = ndi->linkmtu;
+
+	switch(ifp->if_type) {
+	 case IFT_ARCNET:	/* XXX MTU handling needs more work */
+		 ndi->maxmtu = MIN(60480, ifp->if_mtu);
+		 break;
+	 case IFT_ETHER:
+		 ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
+		 break;
+#if defined(__FreeBSD__) || defined(__bsdi__)
+	 case IFT_FDDI:
+#if defined(__bsdi__) && _BSDI_VERSION >= 199802
+		 ndi->maxmtu = MIN(FDDIMTU, ifp->if_mtu);
+#else
+		 ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
+#endif
+		 break;
+#endif
+#if !(defined(__bsdi__) && _BSDI_VERSION >= 199802)
+	 case IFT_ATM:
+		 ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
+		 break;
+#endif
+	 default:
+		 ndi->maxmtu = ifp->if_mtu;
+		 break;
+	}
+
+	if (oldmaxmtu != ndi->maxmtu) {
+		/*
+		 * If the ND level MTU is not set yet, or if the maxmtu
+		 * is reset to a smaller value than the ND level MTU,
+		 * also reset the ND level MTU.
+		 */
+		if (ndi->linkmtu == 0 ||
+		    ndi->maxmtu < ndi->linkmtu) {
+			ndi->linkmtu = ndi->maxmtu;
+			/* also adjust in6_maxmtu if necessary. */
+			if (oldlinkmtu == 0) {
+				/*
+				 * XXX: the case analysis is grotty, but
+				 * it is not efficient to call in6_setmaxmtu()
+				 * here when we are during the initialization
+				 * procedure.
+				 */
+				if (in6_maxmtu < ndi->linkmtu)
+					in6_maxmtu = ndi->linkmtu;
+			}
+			else
+				in6_setmaxmtu();
+		}
+	}
+#undef MIN
+}
+
+void
+nd6_option_init(opt, icmp6len, ndopts)
+	void *opt;
+	int icmp6len;
+	union nd_opts *ndopts;
+{
+	bzero(ndopts, sizeof(*ndopts));
+	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
+	ndopts->nd_opts_last
+		= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
+
+	if (icmp6len == 0) {
+		ndopts->nd_opts_done = 1;
+		ndopts->nd_opts_search = NULL;
+	}
+}
+
+/*
+ * Take one ND option.
+ */
+struct nd_opt_hdr *
+nd6_option(ndopts)
+	union nd_opts *ndopts;
+{
+	struct nd_opt_hdr *nd_opt;
+	int olen;
+
+	if (!ndopts)
+		panic("ndopts == NULL in nd6_option\n");
+	if (!ndopts->nd_opts_last)
+		panic("uninitialized ndopts in nd6_option\n");
+	if (!ndopts->nd_opts_search)
+		return NULL;
+	if (ndopts->nd_opts_done)
+		return NULL;
+
+	nd_opt = ndopts->nd_opts_search;
+
+	olen = nd_opt->nd_opt_len << 3;
+	if (olen == 0) {
+		/*
+		 * Message validation requires that all included
+		 * options have a length that is greater than zero.
+		 */
+		bzero(ndopts, sizeof(*ndopts));
+		return NULL;
+	}
+
+	ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
+	if (!(ndopts->nd_opts_search < ndopts->nd_opts_last)) {
+		ndopts->nd_opts_done = 1;
+		ndopts->nd_opts_search = NULL;
+	}
+	return nd_opt;
+}
+
+/*
+ * Parse multiple ND options.
+ * This function is much easier to use, for ND routines that do not need
+ * multiple options of the same type.
+ */
+int
+nd6_options(ndopts)
+	union nd_opts *ndopts;
+{
+	struct nd_opt_hdr *nd_opt;
+	int i = 0;
+
+	if (!ndopts)
+		panic("ndopts == NULL in nd6_options\n");
+	if (!ndopts->nd_opts_last)
+		panic("uninitialized ndopts in nd6_options\n");
+	if (!ndopts->nd_opts_search)
+		return 0;
+
+	while (1) {
+		nd_opt = nd6_option(ndopts);
+		if (!nd_opt && !ndopts->nd_opts_last) {
+			/*
+			 * Message validation requires that all included
+			 * options have a length that is greater than zero.
+			 */
+			bzero(ndopts, sizeof(*ndopts));
+			return -1;
+		}
+
+		if (!nd_opt)
+			goto skip1;
+
+		switch (nd_opt->nd_opt_type) {
+		case ND_OPT_SOURCE_LINKADDR:
+		case ND_OPT_TARGET_LINKADDR:
+		case ND_OPT_MTU:
+		case ND_OPT_REDIRECTED_HEADER:
+			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
+				printf("duplicated ND6 option found "
+					"(type=%d)\n", nd_opt->nd_opt_type);
+				/* XXX bark? */
+			} else {
+				ndopts->nd_opt_array[nd_opt->nd_opt_type]
+					= nd_opt;
+			}
+			break;
+		case ND_OPT_PREFIX_INFORMATION:
+			if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
+				ndopts->nd_opt_array[nd_opt->nd_opt_type]
+					= nd_opt;
+			}
+			ndopts->nd_opts_pi_end =
+				(struct nd_opt_prefix_info *)nd_opt;
+			break;
+		default:
+			/*
+			 * Unknown options must be silently ignored,
+			 * to accomodate future extension to the protocol.
+			 */
+			log(LOG_INFO,
+			    "nd6_options: unsupported option %d - "
+			    "option ignored\n", nd_opt->nd_opt_type);
+		}
+
+skip1:
+		i++;
+		if (i > nd6_maxndopt) {
+			icmp6stat.icp6s_nd_toomanyopt++;
+			printf("too many loop in nd opt\n");
+			break;
+		}
+
+		if (ndopts->nd_opts_done)
+			break;
+	}
+
+	return 0;
+}
+
+/*
+ * ND6 timer routine to expire default route list and prefix list
+ */
+void
+nd6_timer(ignored_arg)
+	void	*ignored_arg;
+{
+	int s;
+	register struct llinfo_nd6 *ln;
+	register struct nd_defrouter *dr;
+	register struct nd_prefix *pr;
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+	long time_second = time.tv_sec;
+#endif
+	
+#ifdef __NetBSD__
+	s = splsoftnet();
+#else
+	s = splnet();
+#endif
+	timeout(nd6_timer, (caddr_t)0, nd6_prune * hz);
+
+	ln = llinfo_nd6.ln_next;
+	/* XXX BSD/OS separates this code -- itojun */
+	while (ln && ln != &llinfo_nd6) {
+		struct rtentry *rt;
+		struct ifnet *ifp;
+		struct sockaddr_in6 *dst;
+		struct llinfo_nd6 *next = ln->ln_next;
+
+		if ((rt = ln->ln_rt) == NULL) {
+			ln = next;
+			continue;
+		}
+		if ((ifp = rt->rt_ifp) == NULL) {
+			ln = next;
+			continue;
+		}
+		dst = (struct sockaddr_in6 *)rt_key(rt);
+
+		if (ln->ln_expire > time_second) {
+			ln = next;
+			continue;
+		}
+		
+		/* sanity check */
+		if (!rt)
+			panic("rt=0 in nd6_timer(ln=%p)\n", ln);
+		if (!dst)
+			panic("dst=0 in nd6_timer(ln=%p)\n", ln);
+
+		switch (ln->ln_state) {
+		case ND6_LLINFO_INCOMPLETE:
+			if (ln->ln_asked < nd6_mmaxtries) {
+				ln->ln_asked++;
+				ln->ln_expire = time_second +
+					nd_ifinfo[ifp->if_index].retrans / 1000;
+				nd6_ns_output(ifp, NULL, &dst->sin6_addr,
+					ln, 0);
+			} else {
+				struct mbuf *m = ln->ln_hold;
+				if (m) {
+					if (rt->rt_ifp) {
+						/*
+						 * Fake rcvif to make ICMP error
+						 * more helpful in diagnosing
+						 * for the receiver.
+						 * XXX: should we consider
+						 * older rcvif?
+						 */
+						m->m_pkthdr.rcvif = rt->rt_ifp;
+					}
+					icmp6_error(m, ICMP6_DST_UNREACH,
+						    ICMP6_DST_UNREACH_ADDR, 0);
+					ln->ln_hold = NULL;
+				}
+				nd6_free(rt);
+			}
+			break;
+		case ND6_LLINFO_REACHABLE:
+			if (ln->ln_expire) {
+				ln->ln_state = ND6_LLINFO_STALE;
+			}
+			break;
+		/* 
+		 * ND6_LLINFO_STALE state requires nothing for timer
+		 * routine.
+		 */
+		case ND6_LLINFO_DELAY:
+			ln->ln_asked = 1;
+			ln->ln_state = ND6_LLINFO_PROBE;
+			ln->ln_expire = time_second +
+				nd_ifinfo[ifp->if_index].retrans / 1000;
+			nd6_ns_output(ifp, &dst->sin6_addr, &dst->sin6_addr,
+				ln, 0);
+			break;
+
+		case ND6_LLINFO_PROBE:
+			if (ln->ln_asked < nd6_umaxtries) {
+				ln->ln_asked++;
+				ln->ln_expire = time_second +
+					nd_ifinfo[ifp->if_index].retrans / 1000;
+				nd6_ns_output(ifp, &dst->sin6_addr,
+					       &dst->sin6_addr, ln, 0);
+			} else {
+				nd6_free(rt);
+			}
+			break;
+		case ND6_LLINFO_WAITDELETE:
+			nd6_free(rt);
+			break;
+		}
+		ln = next;
+	}
+	
+	/* expire */
+	dr = nd_defrouter.lh_first;
+	while (dr) {
+		if (dr->expire && dr->expire < time_second) {
+			struct nd_defrouter *t;
+			t = dr->dr_next;
+			defrtrlist_del(dr);
+			dr = t;
+		} else
+			dr = dr->dr_next;
+	}
+	pr = nd_prefix.lh_first;
+	while (pr) {
+		struct in6_ifaddr *ia6;
+		struct in6_addrlifetime *lt6;
+
+		if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
+			ia6 = NULL;
+		else
+			ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr);
+
+		if (ia6) {
+			/* check address lifetime */
+			lt6 = &ia6->ia6_lifetime;
+			if (lt6->ia6t_preferred && lt6->ia6t_preferred < time_second)
+				ia6->ia6_flags |= IN6_IFF_DEPRECATED;
+			if (lt6->ia6t_expire && lt6->ia6t_expire < time_second) {
+				if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
+					in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
+				/* xxx ND_OPT_PI_FLAG_ONLINK processing */
+			}
+		}
+
+		/*
+		 * check prefix lifetime.
+		 * since pltime is just for autoconf, pltime processing for
+		 * prefix is not necessary.
+		 *
+		 * we offset expire time by NDPR_KEEP_EXPIRE, so that we
+		 * can use the old prefix information to validate the
+		 * next prefix information to come.  See prelist_update()
+		 * for actual validation.
+		 */
+		if (pr->ndpr_expire
+		 && pr->ndpr_expire + NDPR_KEEP_EXPIRED < time_second) {
+			struct nd_prefix *t;
+			t = pr->ndpr_next;
+
+			/*
+			 * address expiration and prefix expiration are
+			 * separate.  NEVER perform in6_ifdel here.
+			 */
+
+			prelist_remove(pr);
+			pr = t;
+		} else
+			pr = pr->ndpr_next;
+	}
+	splx(s);
+}
+
+struct rtentry *
+nd6_lookup(addr6, create, ifp)
+	struct in6_addr *addr6;
+	int create;
+	struct ifnet *ifp;
+{
+	struct rtentry *rt;
+	struct sockaddr_in6 sin6;
+
+	bzero(&sin6, sizeof(sin6));
+	sin6.sin6_len = sizeof(struct sockaddr_in6);
+	sin6.sin6_family = AF_INET6;
+	sin6.sin6_addr = *addr6;
+	rt = rtalloc1((struct sockaddr *)&sin6, create
+#ifdef __FreeBSD__
+		      , 0UL
+#endif /*__FreeBSD__*/
+		      );
+	if (rt && (rt->rt_flags & RTF_LLINFO) == 0) {
+		/*
+		 * This is the case for the default route.
+		 * If we want to create a neighbor cache for the address, we 
+		 * should free the route for the destination and allocate an
+		 * interface route.
+		 */
+		if (create) {
+			RTFREE(rt);
+			rt = 0;
+		}
+	}
+	if (!rt) {
+		if (create && ifp) {
+			/*
+			 * If no route is available and create is set,
+			 * we allocate a host route for the destination
+			 * and treat it like an interface route.
+			 * This hack is necessary for a neighbor which can't
+			 * be covered by our own prefix.
+			 */
+			struct ifaddr *ifa =
+				ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
+			if (ifa == NULL)
+				return(NULL);
+
+			/*
+			 * Create a new route. RTF_LLINFO is necessary
+			 * to create a Neighbor Cache entry for the
+			 * destination in nd6_rtrequest which will be
+			 * called in rtequest via ifa->ifa_rtrequest. 
+			 */
+			if (rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
+				      ifa->ifa_addr,
+				      (struct sockaddr *)&all1_sa,
+				      (ifa->ifa_flags |
+				       RTF_HOST | RTF_LLINFO) & ~RTF_CLONING,
+				      &rt))
+				log(LOG_ERR,
+				    "nd6_lookup: failed to add route for a "
+				    "neighbor(%s)\n", ip6_sprintf(addr6));
+			if (rt == NULL)
+				return(NULL);
+			if (rt->rt_llinfo) {
+				struct llinfo_nd6 *ln =
+					(struct llinfo_nd6 *)rt->rt_llinfo;
+				ln->ln_state = ND6_LLINFO_NOSTATE;
+			}
+		}
+		else
+			return(NULL);
+	}
+	rt->rt_refcnt--;
+	/*
+	 * Validation for the entry.
+	 * XXX: we can't use rt->rt_ifp to check for the interface, since
+	 *      it might be the loopback interface if the entry is for our
+	 *      own address on a non-loopback interface. Instead, we should
+	 *      use rt->rt_ifa->ifa_ifp, which would specify the REAL interface.
+	 */
+	if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
+	    rt->rt_gateway->sa_family != AF_LINK ||
+	    (ifp && rt->rt_ifa->ifa_ifp != ifp)) {
+		if (create) {
+			log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n",
+			    ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec");
+			/* xxx more logs... kazu */
+		}
+		return(0);
+	}
+	return(rt);
+}
+
+/*
+ * Detect if a given IPv6 address identifies a neighbor on a given link.
+ * XXX: should take care of the destination of a p2p link? 
+ */
+int
+nd6_is_addr_neighbor(addr, ifp)
+	struct in6_addr *addr;
+	struct ifnet *ifp;
+{
+	register struct ifaddr *ifa;
+	int i;
+
+#define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr)
+#define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr)
+
+	/* A link-local address is always a neighbor. */
+	if (IN6_IS_ADDR_LINKLOCAL(addr))
+		return(1);
+
+	/*
+	 * If the address matches one of our addresses,
+	 * it should be a neighbor.
+	 */
+#if defined(__bsdi__) || (defined(__FreeBSD__) && __FreeBSD__ < 3)
+	for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
+#else
+	for (ifa = ifp->if_addrlist.tqh_first;
+	     ifa;
+	     ifa = ifa->ifa_list.tqe_next)
+#endif
+	{
+		if (ifa->ifa_addr->sa_family != AF_INET6)
+			next: continue;
+
+		for (i = 0; i < 4; i++) {
+			if ((IFADDR6(ifa).s6_addr32[i] ^ addr->s6_addr32[i]) &
+			    IFMASK6(ifa).s6_addr32[i])
+				goto next;
+		}
+		return(1);
+	}
+
+	/*
+	 * Even if the address matches none of our addresses, it might be
+	 * in the neighbor cache.
+	 */
+	if (nd6_lookup(addr, 0, ifp))
+		return(1);
+
+	return(0);
+#undef IFADDR6
+#undef IFMASK6
+}
+
+/*
+ * Free an nd6 llinfo entry.
+ */
+void
+nd6_free(rt)
+	struct rtentry *rt;
+{
+	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	struct sockaddr_dl *sdl;
+
+	if (ln->ln_router) {
+		/* remove from default router list */
+		struct nd_defrouter *dr;
+		struct in6_addr *in6;
+		int s;
+		in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
+
+#ifdef __NetBSD__
+		s = splsoftnet();
+#else
+		s = splnet();
+#endif
+		dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->
+				      sin6_addr,
+				      rt->rt_ifp);
+		if (dr)
+			defrtrlist_del(dr);
+		else if (!ip6_forwarding && ip6_accept_rtadv) {
+			/*
+			 * rt6_flush must be called in any case.
+			 * see the comment in nd6_na_input().
+			 */
+			rt6_flush(in6, rt->rt_ifp);
+		}
+		splx(s);
+	}
+	
+	if (rt->rt_refcnt > 0 && (sdl = SDL(rt->rt_gateway)) &&
+	   sdl->sdl_family == AF_LINK) {
+		sdl->sdl_alen = 0;
+		ln->ln_state = ND6_LLINFO_WAITDELETE;
+		ln->ln_asked = 0;
+		rt->rt_flags &= ~RTF_REJECT;
+		return;
+	}
+	rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, rt_mask(rt),
+		  0, (struct rtentry **)0);
+}
+
+/*
+ * Upper-layer reachability hint for Neighbor Unreachability Detection.
+ *
+ * XXX cost-effective metods?
+ */
+void
+nd6_nud_hint(rt, dst6)
+	struct rtentry *rt;
+	struct in6_addr *dst6;
+{
+	struct llinfo_nd6 *ln;
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+	long time_second = time.tv_sec;
+#endif
+
+	/*
+	 * If the caller specified "rt", use that.  Otherwise, resolve the
+	 * routing table by supplied "dst6".
+	 */
+	if (!rt) {
+		if (!dst6)
+			return;
+		if (!(rt = nd6_lookup(dst6, 0, NULL)))
+			return;
+	}
+
+	if ((rt->rt_flags & RTF_GATEWAY)
+	 || (rt->rt_flags & RTF_LLINFO) == 0
+	 || !rt->rt_llinfo
+	 || !rt->rt_gateway
+	 || rt->rt_gateway->sa_family != AF_LINK) {
+		/* This is not a host route. */
+		return;
+	}
+
+	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	if (ln->ln_state == ND6_LLINFO_INCOMPLETE)
+		return;
+
+	ln->ln_state = ND6_LLINFO_REACHABLE;
+	if (ln->ln_expire)
+		ln->ln_expire = time_second +
+			nd_ifinfo[rt->rt_ifp->if_index].reachable;
+}
+
+#ifdef OLDIP6OUTPUT
+/*
+ * Resolve an IP6 address into an ethernet address. If success,
+ * desten is filled in. If there is no entry in ndptab,
+ * set one up and multicast a solicitation for the IP6 address.
+ * Hold onto this mbuf and resend it once the address
+ * is finally resolved. A return value of 1 indicates
+ * that desten has been filled in and the packet should be sent
+ * normally; a 0 return indicates that the packet has been
+ * taken over here, either now or for later transmission.
+ */
+int
+nd6_resolve(ifp, rt, m, dst, desten)
+	struct ifnet *ifp;
+	struct rtentry *rt;
+	struct mbuf *m;
+	struct sockaddr *dst;
+	u_char *desten;
+{
+	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)NULL;
+	struct sockaddr_dl *sdl;
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+	long time_second = time.tv_sec;
+#endif
+
+	if (m->m_flags & M_MCAST) {
+		switch (ifp->if_type) {
+		case IFT_ETHER:
+		case IFT_FDDI:			
+			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
+						 desten);
+			return(1);
+			break;
+		case IFT_ARCNET:
+			*desten = 0;
+			return(1);
+			break;
+		default:
+			return(0);
+		}
+	}
+	if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
+		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	else {
+		if ((rt = nd6_lookup(&(SIN6(dst)->sin6_addr), 1, ifp)) != NULL)
+			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	}
+	if (!ln || !rt) {
+		log(LOG_DEBUG, "nd6_resolve: can't allocate llinfo for %s\n",
+			ip6_sprintf(&(SIN6(dst)->sin6_addr)));
+		m_freem(m);
+		return(0);
+	}
+	sdl = SDL(rt->rt_gateway);
+	/*
+	 * Ckeck the address family and length is valid, the address
+	 * is resolved; otherwise, try to resolve.
+	 */
+	if (ln->ln_state >= ND6_LLINFO_REACHABLE
+	   && sdl->sdl_family == AF_LINK
+	   && sdl->sdl_alen != 0) {
+		bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
+		if (ln->ln_state == ND6_LLINFO_STALE) {
+			ln->ln_asked = 0;
+			ln->ln_state = ND6_LLINFO_DELAY;
+			ln->ln_expire = time_second + nd6_delay;
+		}
+		return(1);
+	}
+	/*
+	 * There is an ndp entry, but no ethernet address
+	 * response yet. Replace the held mbuf with this
+	 * latest one.
+	 *
+	 * XXX Does the code conform to rate-limiting rule?
+	 * (RFC 2461 7.2.2)
+	 */
+	if (ln->ln_state == ND6_LLINFO_WAITDELETE ||
+	    ln->ln_state == ND6_LLINFO_NOSTATE)
+		ln->ln_state = ND6_LLINFO_INCOMPLETE;
+	if (ln->ln_hold)
+		m_freem(ln->ln_hold);
+	ln->ln_hold = m;
+	if (ln->ln_expire) {
+		rt->rt_flags &= ~RTF_REJECT;
+		if (ln->ln_asked < nd6_mmaxtries &&
+		    ln->ln_expire < time_second) {
+			ln->ln_asked++;
+			ln->ln_expire = time_second +
+				nd_ifinfo[ifp->if_index].retrans / 1000;
+			nd6_ns_output(ifp, NULL, &(SIN6(dst)->sin6_addr),
+				ln, 0);
+		}
+	}
+	return(0);
+}
+#endif /* OLDIP6OUTPUT */
+
+void
+#if defined(__bsdi__) && _BSDI_VERSION >= 199802
+nd6_rtrequest(req, rt, info)
+	int	req;
+	struct rtentry *rt;
+	struct rt_addrinfo *info; /* xxx unused */
+#else
+nd6_rtrequest(req, rt, sa)
+	int	req;
+	struct rtentry *rt;
+	struct sockaddr *sa; /* xxx unused */
+#endif
+{
+	struct sockaddr *gate = rt->rt_gateway;
+	struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
+	struct ifnet *ifp = rt->rt_ifp;
+	struct ifaddr *ifa;
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+	long time_second = time.tv_sec;
+#endif
+
+	if (rt->rt_flags & RTF_GATEWAY)
+		return;
+
+	switch (req) {
+	case RTM_ADD:
+		/*
+		 * There is no backward compatibility :)
+		 *
+		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
+		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
+		 *	   rt->rt_flags |= RTF_CLONING;
+		 */
+		if (rt->rt_flags & RTF_CLONING || rt->rt_flags & RTF_LLINFO) {
+			/*
+			 * Case 1: This route should come from
+			 * a route to interface. RTF_LLINFO flag is set
+			 * for a host route whose destination should be
+			 * treated as on-link.
+			 */
+			rt_setgate(rt, rt_key(rt),
+				   (struct sockaddr *)&null_sdl);
+			gate = rt->rt_gateway;
+			SDL(gate)->sdl_type = ifp->if_type;
+			SDL(gate)->sdl_index = ifp->if_index;
+			if (ln)
+				ln->ln_expire = time_second;
+#if 1
+			if (ln && ln->ln_expire == 0) {
+				/* cludge for desktops */
+#if 0
+				printf("nd6_request: time.tv_sec is zero; "
+				       "treat it as 1\n");
+#endif
+				ln->ln_expire = 1;
+			}
+#endif
+			if (rt->rt_flags & RTF_CLONING)
+				break;
+		}
+		/* Announce a new entry if requested. */
+		if (rt->rt_flags & RTF_ANNOUNCE)
+			nd6_na_output(ifp,
+				      &SIN6(rt_key(rt))->sin6_addr,
+				      &SIN6(rt_key(rt))->sin6_addr,
+				      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
+				      1);
+		/* FALLTHROUGH */
+	case RTM_RESOLVE:
+		if (gate->sa_family != AF_LINK ||
+		   gate->sa_len < sizeof(null_sdl)) {
+			log(LOG_DEBUG, "nd6_rtrequest: bad gateway value\n");
+			break;
+		}
+		SDL(gate)->sdl_type = ifp->if_type;
+		SDL(gate)->sdl_index = ifp->if_index;
+		if (ln != 0)
+			break;	/* This happens on a route change */
+		/*
+		 * Case 2: This route may come from cloning, or a manual route
+		 * add with a LL address.
+		 */
+		R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
+		rt->rt_llinfo = (caddr_t)ln;
+		if (!ln) {
+			log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
+			break;
+		}
+		nd6_inuse++;
+		nd6_allocated++;
+		Bzero(ln, sizeof(*ln));
+		ln->ln_rt = rt;
+		/* this is required for "ndp" command. - shin */
+		if (req == RTM_ADD) {
+		        /*
+			 * gate should have some valid AF_LINK entry,
+			 * and ln->ln_expire should have some lifetime
+			 * which is specified by ndp command.
+			 */
+			ln->ln_state = ND6_LLINFO_REACHABLE;
+		} else {
+		        /* 
+			 * When req == RTM_RESOLVE, rt is created and
+			 * initialized in rtrequest(), so rt_expire is 0.
+			 */
+			ln->ln_state = ND6_LLINFO_NOSTATE;
+			ln->ln_expire = time_second;
+		}
+		rt->rt_flags |= RTF_LLINFO;
+#if 0
+		insque(ln, &llinfo_nd6);
+#else
+		ln->ln_next = llinfo_nd6.ln_next;
+		llinfo_nd6.ln_next = ln;
+		ln->ln_prev = &llinfo_nd6;
+		ln->ln_next->ln_prev = ln;
+#endif
+
+		/*
+		 * check if rt_key(rt) is one of my address assigned
+		 * to the interface.
+		 */
+		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
+					  &SIN6(rt_key(rt))->sin6_addr);
+		if (ifa) {
+			caddr_t macp = nd6_ifptomac(ifp);
+			ln->ln_expire = 0;
+			ln->ln_state = ND6_LLINFO_REACHABLE;
+			if (macp) {
+				Bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen);
+				SDL(gate)->sdl_alen = ifp->if_addrlen;
+			}
+			if (nd6_useloopback) {
+#ifdef __bsdi__
+#if _BSDI_VERSION >= 199802
+				extern struct ifnet *loifp;
+				rt->rt_ifp = loifp;	/*XXX*/
+#else
+				extern struct ifnet loif;
+				rt->rt_ifp = &loif;	/*XXX*/
+#endif
+#else /* non-bsdi */
+				rt->rt_ifp = &loif[0];	/*XXX*/
+#endif
+				/*
+				 * Make sure rt_ifa be equal to the ifaddr
+				 * corresponding to the address.
+				 * We need this because when we refer
+				 * rt_ifa->ia6_flags in ip6_input, we assume
+				 * that the rt_ifa points to the address instead
+				 * of the loopback address.
+				 */
+				if (ifa != rt->rt_ifa) {
+					rt->rt_ifa->ifa_refcnt--;
+					ifa->ifa_refcnt++;
+					rt->rt_ifa = ifa;
+				}
+			}
+		}
+		break;
+
+	case RTM_DELETE:
+		if (!ln)
+			break;
+		nd6_inuse--;
+#if 0
+		remque(ln);
+#else
+		ln->ln_next->ln_prev = ln->ln_prev;
+		ln->ln_prev->ln_next = ln->ln_next;
+		ln->ln_prev = NULL;
+#endif
+		rt->rt_llinfo = 0;
+		rt->rt_flags &= ~RTF_LLINFO;
+		if (ln->ln_hold)
+			m_freem(ln->ln_hold);
+		Free((caddr_t)ln);
+	}
+}
+
+void
+#if defined(__bsdi__) && _BSDI_VERSION >= 199802
+nd6_p2p_rtrequest(req, rt, info)
+	int	req;
+	struct rtentry *rt;
+	struct rt_addrinfo *info; /* xxx unused */
+#else
+nd6_p2p_rtrequest(req, rt, sa)
+	int	req;
+	struct rtentry *rt;
+	struct sockaddr *sa; /* xxx unused */
+#endif
+{
+	struct sockaddr *gate = rt->rt_gateway;
+	static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
+	struct ifnet *ifp = rt->rt_ifp;
+	struct ifaddr *ifa;
+
+	if (rt->rt_flags & RTF_GATEWAY)
+		return;
+
+	switch (req) {
+	case RTM_ADD:
+		/*
+		 * There is no backward compatibility :)
+		 *
+		 * if ((rt->rt_flags & RTF_HOST) == 0 &&
+		 *     SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
+		 *	   rt->rt_flags |= RTF_CLONING;
+		 */
+		if (rt->rt_flags & RTF_CLONING) {
+			/*
+			 * Case 1: This route should come from
+			 * a route to interface.
+			 */
+			rt_setgate(rt, rt_key(rt),
+				   (struct sockaddr *)&null_sdl);
+			gate = rt->rt_gateway;
+			SDL(gate)->sdl_type = ifp->if_type;
+			SDL(gate)->sdl_index = ifp->if_index;
+			break;
+		}
+		/* Announce a new entry if requested. */
+		if (rt->rt_flags & RTF_ANNOUNCE)
+			nd6_na_output(ifp,
+				      &SIN6(rt_key(rt))->sin6_addr,
+				      &SIN6(rt_key(rt))->sin6_addr,
+				      ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
+				      1);
+		/* FALLTHROUGH */
+	case RTM_RESOLVE:
+		/*
+		 * check if rt_key(rt) is one of my address assigned
+		 * to the interface.
+		 */
+ 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
+					  &SIN6(rt_key(rt))->sin6_addr);
+		if (ifa) {
+			if (nd6_useloopback) {
+#ifdef __bsdi__
+#if _BSDI_VERSION >= 199802
+				extern struct ifnet *loifp;
+				rt->rt_ifp = loifp;	/*XXX*/
+#else
+				extern struct ifnet loif;
+				rt->rt_ifp = &loif;	/*XXX*/
+#endif
+#else
+				rt->rt_ifp = &loif[0];	/*XXX*/
+#endif /*__bsdi__*/
+			}
+		}
+		break;
+	}
+}
+
+int
+nd6_ioctl(cmd, data, ifp)
+	u_long cmd;
+	caddr_t	data;
+	struct ifnet *ifp;
+{
+	struct in6_drlist *drl = (struct in6_drlist *)data;
+	struct in6_prlist *prl = (struct in6_prlist *)data;
+	struct in6_ndireq *ndi = (struct in6_ndireq *)data;
+	struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
+	struct nd_defrouter *dr, any;
+	struct nd_prefix *pr;
+	struct rtentry *rt;
+	int i = 0, error = 0;
+	int s;
+
+	switch (cmd) {
+	case SIOCGDRLST_IN6:
+		bzero(drl, sizeof(*drl));
+#ifdef __NetBSD__
+		s = splsoftnet();
+#else
+		s = splnet();
+#endif
+		dr = nd_defrouter.lh_first;
+		while (dr && i < DRLSTSIZ) {
+			drl->defrouter[i].rtaddr = dr->rtaddr;
+			if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) {
+				/* XXX: need to this hack for KAME stack */
+				drl->defrouter[i].rtaddr.s6_addr16[1] = 0;
+			}
+			else
+				log(LOG_ERR,
+				    "default router list contains a "
+				    "non-linklocal address(%s)\n",
+				    ip6_sprintf(&drl->defrouter[i].rtaddr));
+
+			drl->defrouter[i].flags = dr->flags;
+			drl->defrouter[i].rtlifetime = dr->rtlifetime;
+			drl->defrouter[i].expire = dr->expire;
+			drl->defrouter[i].if_index = dr->ifp->if_index;
+			i++;
+			dr = dr->dr_next;
+		}
+		splx(s);
+		break;
+	case SIOCGPRLST_IN6:
+		bzero(prl, sizeof(*prl));
+#ifdef __NetBSD__
+		s = splsoftnet();
+#else
+		s = splnet();
+#endif
+		pr = nd_prefix.lh_first;
+		while (pr && i < PRLSTSIZ) {
+			struct nd_pfxrouter *pfr;
+			int j;
+
+			prl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
+			prl->prefix[i].raflags = pr->ndpr_raf;
+			prl->prefix[i].prefixlen = pr->ndpr_plen;
+			prl->prefix[i].vltime = pr->ndpr_vltime;
+			prl->prefix[i].pltime = pr->ndpr_pltime;
+			prl->prefix[i].if_index = pr->ndpr_ifp->if_index;
+			prl->prefix[i].expire = pr->ndpr_expire;
+
+			pfr = pr->ndpr_advrtrs.lh_first;
+			j = 0;
+			while(pfr) {
+				if (j < DRLSTSIZ) {
+#define RTRADDR prl->prefix[i].advrtr[j]
+					RTRADDR = pfr->router->rtaddr;
+					if (IN6_IS_ADDR_LINKLOCAL(&RTRADDR)) {
+						/* XXX: hack for KAME */
+						RTRADDR.s6_addr16[1] = 0;
+					}
+					else
+						log(LOG_ERR,
+						    "a router(%s) advertises "
+						    "a prefix with "
+						    "non-link local address\n",
+						    ip6_sprintf(&RTRADDR));
+#undef RTRADDR
+				}
+				j++;
+				pfr = pfr->pfr_next;
+			}
+			prl->prefix[i].advrtrs = j;
+
+			i++;
+			pr = pr->ndpr_next;
+		}
+		splx(s);
+	      {
+		struct rr_prefix *rpp;
+
+		for (rpp = LIST_FIRST(&rr_prefix); rpp;
+		     rpp = LIST_NEXT(rpp, rp_entry)) {
+			if (i >= PRLSTSIZ)
+				break;
+			prl->prefix[i].prefix = rpp->rp_prefix.sin6_addr;
+			prl->prefix[i].raflags = rpp->rp_raf;
+			prl->prefix[i].prefixlen = rpp->rp_plen;
+			prl->prefix[i].vltime = rpp->rp_vltime;
+			prl->prefix[i].pltime = rpp->rp_pltime;
+			prl->prefix[i].if_index = rpp->rp_ifp->if_index;
+			prl->prefix[i].expire = rpp->rp_expire;
+			prl->prefix[i].advrtrs = 0;
+			i++;
+		}
+	      }
+
+		break;
+	case SIOCGIFINFO_IN6:
+		ndi->ndi = nd_ifinfo[ifp->if_index];
+		break;
+	case SIOCSNDFLUSH_IN6:
+		/* flush default router list */
+		/*
+		 * xxx sumikawa: should not delete route if default
+		 * route equals to the top of default router list
+		 */
+		bzero(&any, sizeof(any));
+		defrouter_delreq(&any, 0);
+		/* xxx sumikawa: flush prefix list */
+		break;
+	case SIOCSPFXFLUSH_IN6:
+	    {
+		/* flush all the prefix advertised by routers */
+		struct nd_prefix *pr, *next;
+
+#ifdef __NetBSD__
+		s = splsoftnet();
+#else
+		s = splnet();
+#endif
+		for (pr = nd_prefix.lh_first; pr; pr = next) {
+			next = pr->ndpr_next;
+			if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
+				in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
+			prelist_remove(pr);
+		}
+		splx(s);
+		break;
+	    }
+	case SIOCSRTRFLUSH_IN6:
+	    {
+		/* flush all the default routers */
+		struct nd_defrouter *dr, *next;
+
+#ifdef __NetBSD__
+		s = splsoftnet();
+#else
+		s = splnet();
+#endif
+		if ((dr = nd_defrouter.lh_first) != NULL) {
+			/*
+			 * The first entry of the list may be stored in
+			 * the routing table, so we'll delete it later.
+			 */
+			for (dr = dr->dr_next; dr; dr = next) {
+				next = dr->dr_next;
+				defrtrlist_del(dr);
+			}
+			defrtrlist_del(nd_defrouter.lh_first);
+		}
+		splx(s);
+		break;
+	    }
+	case SIOCGNBRINFO_IN6:
+	    {
+		struct llinfo_nd6 *ln;
+		struct in6_addr nb_addr = nbi->addr; /* make local for safety */
+
+		/*
+		 * XXX: KAME specific hack for scoped addresses
+		 *      XXXX: for other scopes than link-local?
+		 */
+		if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) ||
+		    IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) {
+			u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2];
+
+			if (*idp == 0)
+				*idp = htons(ifp->if_index);
+		}
+
+#ifdef __NetBSD__
+		s = splsoftnet();
+#else
+		s = splnet();
+#endif
+		if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL) {
+			error = EINVAL;
+			break;
+		}
+		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+		nbi->state = ln->ln_state;
+		nbi->asked = ln->ln_asked;
+		nbi->isrouter = ln->ln_router;
+		nbi->expire = ln->ln_expire;
+		splx(s);
+		
+		break;
+	    }
+	}
+	return(error);
+}
+
+/*
+ * Create neighbor cache entry and cache link-layer address,
+ * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
+ */
+struct rtentry *
+nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code)
+	struct ifnet *ifp;
+	struct in6_addr *from;
+	char *lladdr;
+	int lladdrlen;
+	int type;	/* ICMP6 type */
+	int code;	/* type dependent information */
+{
+	struct rtentry *rt = NULL;
+	struct llinfo_nd6 *ln = NULL;
+	int is_newentry;
+	struct sockaddr_dl *sdl = NULL;
+	int do_update;
+	int olladdr;
+	int llchange;
+	int newstate = 0;
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+	long time_second = time.tv_sec;
+#endif
+
+	if (!ifp)
+		panic("ifp == NULL in nd6_cache_lladdr");
+	if (!from)
+		panic("from == NULL in nd6_cache_lladdr");
+
+	/* nothing must be updated for unspecified address */
+	if (IN6_IS_ADDR_UNSPECIFIED(from))
+		return NULL;
+
+	/*
+	 * Validation about ifp->if_addrlen and lladdrlen must be done in
+	 * the caller.
+	 *
+	 * XXX If the link does not have link-layer adderss, what should
+	 * we do? (ifp->if_addrlen == 0)
+	 * Spec says nothing in sections for RA, RS and NA.  There's small
+	 * description on it in NS section (RFC 2461 7.2.3).
+	 */
+
+	rt = nd6_lookup(from, 0, ifp);
+	if (!rt) {
+#if 0
+		/* nothing must be done if there's no lladdr */
+		if (!lladdr || !lladdrlen)
+			return NULL;
+#endif
+
+		rt = nd6_lookup(from, 1, ifp);
+		is_newentry = 1;
+	} else
+		is_newentry = 0;
+
+	if (!rt)
+		return NULL;
+	if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
+fail:
+		nd6_free(rt);
+		return NULL;
+	}
+	ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	if (!ln)
+		goto fail;
+	if (!rt->rt_gateway)
+		goto fail;
+	if (rt->rt_gateway->sa_family != AF_LINK)
+		goto fail;
+	sdl = SDL(rt->rt_gateway);
+
+	olladdr = (sdl->sdl_alen) ? 1 : 0;
+	if (olladdr && lladdr) {
+		if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
+			llchange = 1;
+		else
+			llchange = 0;
+	} else
+		llchange = 0;
+
+	/*
+	 * newentry olladdr  lladdr  llchange	(*=record)
+	 *	0	n	n	--	(1)
+	 *	0	y	n	--	(2)
+	 *	0	n	y	--	(3) * STALE
+	 *	0	y	y	n	(4) *
+	 *	0	y	y	y	(5) * STALE
+	 *	1	--	n	--	(6)   NOSTATE(= PASSIVE)
+	 *	1	--	y	--	(7) * STALE
+	 */
+
+	if (lladdr) {		/*(3-5) and (7)*/
+		/*
+		 * Record source link-layer address
+		 * XXX is it dependent to ifp->if_type?
+		 */
+		sdl->sdl_alen = ifp->if_addrlen;
+		bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
+	}
+
+	if (!is_newentry) {
+		if ((!olladdr && lladdr)		/*(3)*/
+		 || (olladdr && lladdr && llchange)) {	/*(5)*/
+			do_update = 1;
+			newstate = ND6_LLINFO_STALE;
+		} else					/*(1-2,4)*/
+			do_update = 0;
+	} else {
+		do_update = 1;
+		if (!lladdr)				/*(6)*/
+			newstate = ND6_LLINFO_NOSTATE;
+		else					/*(7)*/
+			newstate = ND6_LLINFO_STALE;
+	}
+
+	if (do_update) {
+		/*
+		 * Update the state of the neighbor cache.
+		 */
+		ln->ln_state = newstate;
+
+		if (ln->ln_state == ND6_LLINFO_STALE) {
+			rt->rt_flags &= ~RTF_REJECT;
+			if (ln->ln_hold) {
+#ifdef OLDIP6OUTPUT
+				(*ifp->if_output)(ifp, ln->ln_hold,
+						  rt_key(rt), rt);
+#else
+				nd6_output(ifp, ln->ln_hold,
+					   (struct sockaddr_in6 *)rt_key(rt),
+					   rt);
+#endif 
+				ln->ln_hold = 0;
+			}
+		} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
+			/* probe right away */
+			ln->ln_expire = time_second;
+		}
+	}
+
+	/*
+	 * ICMP6 type dependent behavior.
+	 *
+	 * NS: clear IsRouter if new entry
+	 * RS: clear IsRouter
+	 * RA: set IsRouter if there's lladdr
+	 * redir: clear IsRouter if new entry
+	 *
+	 * RA case, (1):
+	 * The spec says that we must set IsRouter in the following cases:
+	 * - If lladdr exist, set IsRouter.  This means (1-5).
+	 * - If it is old entry (!newentry), set IsRouter.  This means (7).
+	 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
+	 * A quetion arises for (1) case.  (1) case has no lladdr in the
+	 * neighbor cache, this is similar to (6).
+	 * This case is rare but we figured that we MUST NOT set IsRouter.
+	 *
+	 * newentry olladdr  lladdr  llchange	    NS  RS  RA	redir
+	 *							D R
+	 *	0	n	n	--	(1)	c   ?     s
+	 *	0	y	n	--	(2)	c   s     s
+	 *	0	n	y	--	(3)	c   s     s
+	 *	0	y	y	n	(4)	c   s     s
+	 *	0	y	y	y	(5)	c   s     s
+	 *	1	--	n	--	(6) c	c 	c s
+	 *	1	--	y	--	(7) c	c   s	c s
+	 *
+	 *					(c=clear s=set)
+	 */
+	switch (type & 0xff) {
+	case ND_NEIGHBOR_SOLICIT:
+		/*
+		 * New entry must have is_router flag cleared.
+		 */
+		if (is_newentry)	/*(6-7)*/
+			ln->ln_router = 0;
+		break;
+	case ND_REDIRECT:
+		/*
+		 * If the icmp is a redirect to a better router, always set the
+		 * is_router flag. Otherwise, if the entry is newly created, 
+		 * clear the flag. [RFC 2461, sec 8.3]
+		 * 
+		 */
+		if (code == ND_REDIRECT_ROUTER)
+			ln->ln_router = 1;
+		else if (is_newentry) /*(6-7)*/
+			ln->ln_router = 0;
+		break;
+	case ND_ROUTER_SOLICIT:
+		/*
+		 * is_router flag must always be cleared.
+		 */
+		ln->ln_router = 0;
+		break;
+	case ND_ROUTER_ADVERT:
+		/*
+		 * Mark an entry with lladdr as a router.
+		 */
+		if ((!is_newentry && (olladdr || lladdr))	/*(2-5)*/
+		 || (is_newentry && lladdr)) {			/*(7)*/
+			ln->ln_router = 1;
+		}
+		break;
+	}
+
+	return rt;
+}
+
+static void
+nd6_slowtimo(ignored_arg)
+    void *ignored_arg;
+{
+#ifdef __NetBSD__
+	int s = splsoftnet();
+#else
+	int s = splnet();
+#endif
+	register int i;
+	register struct nd_ifinfo *nd6if;
+
+	timeout(nd6_slowtimo, (caddr_t)0, ND6_SLOWTIMER_INTERVAL * hz);
+	for (i = 1; i < if_index + 1; i++) {
+		nd6if = &nd_ifinfo[i];
+		if (nd6if->basereachable && /* already initialized */
+		    (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
+			/*
+			 * Since reachable time rarely changes by router
+			 * advertisements, we SHOULD insure that a new random
+			 * value gets recomputed at least once every few hours.
+			 * (RFC 2461, 6.3.4)
+			 */
+			nd6if->recalctm = nd6_recalc_reachtm_interval;
+			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
+		}
+	}
+	splx(s);
+}
+
+#define senderr(e) { error = (e); goto bad;}
+int
+nd6_output(ifp, m0, dst, rt0)
+	register struct ifnet *ifp;
+	struct mbuf *m0;
+	struct sockaddr_in6 *dst;
+	struct rtentry *rt0;
+{
+	register struct mbuf *m = m0;
+	register struct rtentry *rt = rt0;
+	struct llinfo_nd6 *ln = NULL;
+	int error = 0;
+#if !(defined(__FreeBSD__) && __FreeBSD__ >= 3)
+	long time_second = time.tv_sec;
+#endif
+
+	if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
+		goto sendpkt;
+
+	/*
+	 * XXX: we currently do not make neighbor cache on any interface
+	 * other than ARCnet, Ethernet and FDDI.
+	 */
+	switch (ifp->if_type) {
+	case IFT_ARCNET:
+	case IFT_ETHER:
+	case IFT_FDDI:
+		break;
+	default:
+		goto sendpkt;
+	}
+
+	/*
+	 * next hop determination. This routine is derived from ether_outpout. 
+	 */
+	if (rt) {
+		if ((rt->rt_flags & RTF_UP) == 0) {
+#ifdef __FreeBSD__
+			if ((rt0 = rt = rtalloc1((struct sockaddr *)dst, 1, 0UL)) !=
+				NULL)
+#else
+			if ((rt0 = rt = rtalloc1((struct sockaddr *)dst, 1)) !=
+				NULL)
+#endif 
+			{
+				rt->rt_refcnt--;
+				if (rt->rt_ifp != ifp)
+					return nd6_output(ifp, m0, dst, rt); /* XXX: loop care? */
+			} else 
+				senderr(EHOSTUNREACH);
+		}
+		if (rt->rt_flags & RTF_GATEWAY) {
+			if (rt->rt_gwroute == 0)
+				goto lookup;
+			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
+				rtfree(rt); rt = rt0;
+#ifdef __FreeBSD__
+			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1, 0UL);
+#else
+			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
+#endif 
+				if ((rt = rt->rt_gwroute) == 0)
+					senderr(EHOSTUNREACH);
+#ifdef __bsdi__
+				/* the "G" test below also prevents rt == rt0 */
+				if ((rt->rt_flags & RTF_GATEWAY) ||
+				    (rt->rt_ifp != ifp)) {
+					rt->rt_refcnt--;
+					rt0->rt_gwroute = 0;
+					senderr(EHOSTUNREACH);
+				}
+#endif 
+			}
+		}
+		if (rt->rt_flags & RTF_REJECT)
+			senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
+	}
+
+	/*
+	 * Address resolution or Neighbor Unreachability Detection
+	 * for the next hop.
+	 * At this point, the destination of the packet must be a unicast
+	 * or an anycast address(i.e. not a multicast).
+	 */
+
+	/* Look up the neighbor cache for the nexthop */
+	if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
+		ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	else {
+		if ((rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
+			ln = (struct llinfo_nd6 *)rt->rt_llinfo;
+	}
+	if (!ln || !rt) {
+		log(LOG_DEBUG, "nd6_output: can't allocate llinfo for %s "
+		    "(ln=%p, rt=%p)\n",
+		    ip6_sprintf(&dst->sin6_addr), ln, rt);
+		senderr(EIO);	/* XXX: good error? */
+	}
+
+
+	/*
+	 * The first time we send a packet to a neighbor whose entry is
+	 * STALE, we have to change the state to DELAY and a sets a timer to
+	 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
+	 * neighbor unreachability detection on expiration.
+	 * (RFC 2461 7.3.3)
+	 */
+	if (ln->ln_state == ND6_LLINFO_STALE) {
+		ln->ln_asked = 0;
+		ln->ln_state = ND6_LLINFO_DELAY;
+		ln->ln_expire = time_second + nd6_delay;
+	}
+
+	/*
+	 * If the neighbor cache entry has a state other than INCOMPLETE
+	 * (i.e. its link-layer address is already reloved), just
+	 * send the packet.
+	 */
+	if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
+		goto sendpkt;
+
+	/*
+	 * There is a neighbor cache entry, but no ethernet address
+	 * response yet. Replace the held mbuf (if any) with this
+	 * latest one.
+	 *
+	 * XXX Does the code conform to rate-limiting rule?
+	 * (RFC 2461 7.2.2)
+	 */
+	if (ln->ln_state == ND6_LLINFO_WAITDELETE ||
+	    ln->ln_state == ND6_LLINFO_NOSTATE)
+		ln->ln_state = ND6_LLINFO_INCOMPLETE;
+	if (ln->ln_hold)
+		m_freem(ln->ln_hold);
+	ln->ln_hold = m;
+	if (ln->ln_expire) {
+		rt->rt_flags &= ~RTF_REJECT;
+		if (ln->ln_asked < nd6_mmaxtries &&
+		    ln->ln_expire < time_second) {
+			ln->ln_asked++;
+			ln->ln_expire = time_second +
+				nd_ifinfo[ifp->if_index].retrans / 1000;
+			nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
+		}
+	}
+	return(0);
+	
+  sendpkt:
+	return((*ifp->if_output)(ifp, m, (struct sockaddr *)dst, rt));
+	
+  bad:
+	if (m)
+		m_freem(m);
+	return (error);
+}	
+#undef senderr
+
+int
+nd6_storelladdr(ifp, rt, m, dst, desten)
+	struct ifnet *ifp;
+	struct rtentry *rt;
+	struct mbuf *m;
+	struct sockaddr *dst;
+	u_char *desten;
+{
+	struct sockaddr_dl *sdl;
+
+	if (m->m_flags & M_MCAST) {
+		switch (ifp->if_type) {
+		case IFT_ETHER:
+		case IFT_FDDI:			
+			ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
+						 desten);
+			return(1);
+			break;
+		case IFT_ARCNET:
+			*desten = 0;
+			return(1);
+		default:
+			return(0);
+		}
+	}
+
+	if (rt == NULL ||
+	    rt->rt_gateway->sa_family != AF_LINK) {
+		printf("nd6_storelladdr: something odd happens\n");
+		return(0);
+	}
+	sdl = SDL(rt->rt_gateway);
+	if (sdl->sdl_alen != 0)
+		bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
+
+	return(1);
+}