Move files to match FreeBSD layout

1 files changed, 1514 insertions, 0 deletions

diff --git a/freebsd/sys/netinet6/nd6_nbr.c b/freebsd/sys/netinet6/nd6_nbr.c
new file mode 100644
index 00000000..44dd3cf1
--- /dev/null
+++ b/freebsd/sys/netinet6/nd6_nbr.c
@@ -0,0 +1,1514 @@
+#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: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
+ */
+
+#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/local/opt_mpath.h>
+
+#include <freebsd/sys/param.h>
+#include <freebsd/sys/systm.h>
+#include <freebsd/sys/malloc.h>
+#include <freebsd/sys/lock.h>
+#include <freebsd/sys/rwlock.h>
+#include <freebsd/sys/mbuf.h>
+#include <freebsd/sys/socket.h>
+#include <freebsd/sys/sockio.h>
+#include <freebsd/sys/time.h>
+#include <freebsd/sys/kernel.h>
+#include <freebsd/sys/errno.h>
+#include <freebsd/sys/syslog.h>
+#include <freebsd/sys/queue.h>
+#include <freebsd/sys/callout.h>
+
+#include <freebsd/net/if.h>
+#include <freebsd/net/if_types.h>
+#include <freebsd/net/if_dl.h>
+#include <freebsd/net/if_var.h>
+#include <freebsd/net/route.h>
+#ifdef RADIX_MPATH
+#include <freebsd/net/radix_mpath.h>
+#endif
+
+#include <freebsd/netinet/in.h>
+#include <freebsd/netinet/in_var.h>
+#include <freebsd/net/if_llatbl.h>
+#define	L3_ADDR_SIN6(le)	((struct sockaddr_in6 *) L3_ADDR(le))
+#include <freebsd/netinet6/in6_var.h>
+#include <freebsd/netinet6/in6_ifattach.h>
+#include <freebsd/netinet/ip6.h>
+#include <freebsd/netinet6/ip6_var.h>
+#include <freebsd/netinet6/scope6_var.h>
+#include <freebsd/netinet6/nd6.h>
+#include <freebsd/netinet/icmp6.h>
+#include <freebsd/netinet/ip_carp.h>
+
+#define SDL(s) ((struct sockaddr_dl *)s)
+
+struct dadq;
+static struct dadq *nd6_dad_find(struct ifaddr *);
+static void nd6_dad_starttimer(struct dadq *, int);
+static void nd6_dad_stoptimer(struct dadq *);
+static void nd6_dad_timer(struct dadq *);
+static void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
+static void nd6_dad_ns_input(struct ifaddr *);
+static void nd6_dad_na_input(struct ifaddr *);
+
+VNET_DEFINE(int, dad_ignore_ns) = 0;	/* ignore NS in DAD - specwise incorrect*/
+VNET_DEFINE(int, dad_maxtry) = 15;	/* max # of *tries* to transmit DAD packet */
+#define	V_dad_ignore_ns			VNET(dad_ignore_ns)
+#define	V_dad_maxtry			VNET(dad_maxtry)
+
+/*
+ * Input a Neighbor Solicitation Message.
+ *
+ * Based on RFC 2461
+ * Based on RFC 2462 (duplicate address detection)
+ */
+void
+nd6_ns_input(struct mbuf *m, int off, int icmp6len)
+{
+	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
+	struct nd_neighbor_solicit *nd_ns;
+	struct in6_addr saddr6 = ip6->ip6_src;
+	struct in6_addr daddr6 = ip6->ip6_dst;
+	struct in6_addr taddr6;
+	struct in6_addr myaddr6;
+	char *lladdr = NULL;
+	struct ifaddr *ifa = NULL;
+	int lladdrlen = 0;
+	int anycast = 0, proxy = 0, tentative = 0;
+	int tlladdr;
+	union nd_opts ndopts;
+	struct sockaddr_dl *proxydl = NULL;
+	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
+
+#ifndef PULLDOWN_TEST
+	IP6_EXTHDR_CHECK(m, off, icmp6len,);
+	nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
+#else
+	IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
+	if (nd_ns == NULL) {
+		ICMP6STAT_INC(icp6s_tooshort);
+		return;
+	}
+#endif
+	ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
+	taddr6 = nd_ns->nd_ns_target;
+	if (in6_setscope(&taddr6, ifp, NULL) != 0)
+		goto bad;
+
+	if (ip6->ip6_hlim != 255) {
+		nd6log((LOG_ERR,
+		    "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
+		    ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
+		    ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
+		goto bad;
+	}
+
+	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
+		/* dst has to be a solicited node multicast address. */
+		if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
+		    /* don't check ifindex portion */
+		    daddr6.s6_addr32[1] == 0 &&
+		    daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
+		    daddr6.s6_addr8[12] == 0xff) {
+			; /* good */
+		} else {
+			nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
+			    "(wrong ip6 dst)\n"));
+			goto bad;
+		}
+	} else if (!V_nd6_onlink_ns_rfc4861) {
+		struct sockaddr_in6 src_sa6;
+
+		/*
+		 * According to recent IETF discussions, it is not a good idea
+		 * to accept a NS from an address which would not be deemed
+		 * to be a neighbor otherwise.  This point is expected to be
+		 * clarified in future revisions of the specification.
+		 */
+		bzero(&src_sa6, sizeof(src_sa6));
+		src_sa6.sin6_family = AF_INET6;
+		src_sa6.sin6_len = sizeof(src_sa6);
+		src_sa6.sin6_addr = saddr6;
+		if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
+			nd6log((LOG_INFO, "nd6_ns_input: "
+				"NS packet from non-neighbor\n"));
+			goto bad;
+		}
+	}
+
+	if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
+		nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
+		goto bad;
+	}
+
+	icmp6len -= sizeof(*nd_ns);
+	nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
+	if (nd6_options(&ndopts) < 0) {
+		nd6log((LOG_INFO,
+		    "nd6_ns_input: invalid ND option, ignored\n"));
+		/* nd6_options have incremented stats */
+		goto freeit;
+	}
+
+	if (ndopts.nd_opts_src_lladdr) {
+		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
+		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
+	}
+
+	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
+		nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
+		    "(link-layer address option)\n"));
+		goto bad;
+	}
+
+	/*
+	 * Attaching target link-layer address to the NA?
+	 * (RFC 2461 7.2.4)
+	 *
+	 * NS IP dst is unicast/anycast			MUST NOT add
+	 * NS IP dst is solicited-node multicast	MUST add
+	 *
+	 * In implementation, we add target link-layer address by default.
+	 * We do not add one in MUST NOT cases.
+	 */
+	if (!IN6_IS_ADDR_MULTICAST(&daddr6))
+		tlladdr = 0;
+	else
+		tlladdr = 1;
+
+	/*
+	 * Target address (taddr6) must be either:
+	 * (1) Valid unicast/anycast address for my receiving interface,
+	 * (2) Unicast address for which I'm offering proxy service, or
+	 * (3) "tentative" address on which DAD is being performed.
+	 */
+	/* (1) and (3) check. */
+	if (ifp->if_carp)
+		ifa = (*carp_iamatch6_p)(ifp, &taddr6);
+	if (ifa == NULL)
+		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
+
+	/* (2) check. */
+	if (ifa == NULL) {
+		struct rtentry *rt;
+		struct sockaddr_in6 tsin6;
+		int need_proxy;
+#ifdef RADIX_MPATH
+		struct route_in6 ro;
+#endif
+
+		bzero(&tsin6, sizeof tsin6);
+		tsin6.sin6_len = sizeof(struct sockaddr_in6);
+		tsin6.sin6_family = AF_INET6;
+		tsin6.sin6_addr = taddr6;
+
+#ifdef RADIX_MPATH
+		bzero(&ro, sizeof(ro));
+		ro.ro_dst = tsin6;
+		rtalloc_mpath((struct route *)&ro, RTF_ANNOUNCE);
+		rt = ro.ro_rt;
+#else
+		rt = rtalloc1((struct sockaddr *)&tsin6, 0, 0);
+#endif
+		need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
+		    rt->rt_gateway->sa_family == AF_LINK);
+		if (rt)
+			RTFREE_LOCKED(rt);
+		if (need_proxy) {
+			/*
+			 * proxy NDP for single entry
+			 */
+			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
+				IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
+			if (ifa) {
+				proxy = 1;
+				proxydl = SDL(rt->rt_gateway);
+			}
+		}
+	}
+	if (ifa == NULL) {
+		/*
+		 * We've got an NS packet, and we don't have that adddress
+		 * assigned for us.  We MUST silently ignore it.
+		 * See RFC2461 7.2.3.
+		 */
+		goto freeit;
+	}
+	myaddr6 = *IFA_IN6(ifa);
+	anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
+	tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
+	if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
+		goto freeit;
+
+	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
+		nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
+		    "(if %d, NS packet %d)\n",
+		    ip6_sprintf(ip6bufs, &taddr6),
+		    ifp->if_addrlen, lladdrlen - 2));
+		goto bad;
+	}
+
+	if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
+		nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
+		    ip6_sprintf(ip6bufs, &saddr6)));
+		goto freeit;
+	}
+
+	/*
+	 * We have neighbor solicitation packet, with target address equals to
+	 * one of my tentative address.
+	 *
+	 * src addr	how to process?
+	 * ---		---
+	 * multicast	of course, invalid (rejected in ip6_input)
+	 * unicast	somebody is doing address resolution -> ignore
+	 * unspec	dup address detection
+	 *
+	 * The processing is defined in RFC 2462.
+	 */
+	if (tentative) {
+		/*
+		 * If source address is unspecified address, it is for
+		 * duplicate address detection.
+		 *
+		 * If not, the packet is for addess resolution;
+		 * silently ignore it.
+		 */
+		if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
+			nd6_dad_ns_input(ifa);
+
+		goto freeit;
+	}
+
+	/*
+	 * If the source address is unspecified address, entries must not
+	 * be created or updated.
+	 * It looks that sender is performing DAD.  Output NA toward
+	 * all-node multicast address, to tell the sender that I'm using
+	 * the address.
+	 * S bit ("solicited") must be zero.
+	 */
+	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
+		struct in6_addr in6_all;
+
+		in6_all = in6addr_linklocal_allnodes;
+		if (in6_setscope(&in6_all, ifp, NULL) != 0)
+			goto bad;
+		nd6_na_output(ifp, &in6_all, &taddr6,
+		    ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
+		    (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0),
+		    tlladdr, (struct sockaddr *)proxydl);
+		goto freeit;
+	}
+
+	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
+	    ND_NEIGHBOR_SOLICIT, 0);
+
+	nd6_na_output(ifp, &saddr6, &taddr6,
+	    ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
+	    (V_ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
+	    tlladdr, (struct sockaddr *)proxydl);
+ freeit:
+	if (ifa != NULL)
+		ifa_free(ifa);
+	m_freem(m);
+	return;
+
+ bad:
+	nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
+		ip6_sprintf(ip6bufs, &saddr6)));
+	nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
+		ip6_sprintf(ip6bufs, &daddr6)));
+	nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
+		ip6_sprintf(ip6bufs, &taddr6)));
+	ICMP6STAT_INC(icp6s_badns);
+	if (ifa != NULL)
+		ifa_free(ifa);
+	m_freem(m);
+}
+
+/*
+ * Output a Neighbor Solicitation Message. Caller specifies:
+ *	- ICMP6 header source IP6 address
+ *	- ND6 header target IP6 address
+ *	- ND6 header source datalink address
+ *
+ * Based on RFC 2461
+ * Based on RFC 2462 (duplicate address detection)
+ *
+ *   ln - for source address determination
+ *  dad - duplicate address detection
+ */
+void
+nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6, 
+    const struct in6_addr *taddr6, struct llentry *ln, int dad)
+{
+	struct mbuf *m;
+	struct ip6_hdr *ip6;
+	struct nd_neighbor_solicit *nd_ns;
+	struct ip6_moptions im6o;
+	int icmp6len;
+	int maxlen;
+	caddr_t mac;
+	struct route_in6 ro;
+
+	if (IN6_IS_ADDR_MULTICAST(taddr6))
+		return;
+
+	/* estimate the size of message */
+	maxlen = sizeof(*ip6) + sizeof(*nd_ns);
+	maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
+	if (max_linkhdr + maxlen >= MCLBYTES) {
+#ifdef DIAGNOSTIC
+		printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
+		    "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
+#endif
+		return;
+	}
+
+	MGETHDR(m, M_DONTWAIT, MT_DATA);
+	if (m && max_linkhdr + maxlen >= MHLEN) {
+		MCLGET(m, M_DONTWAIT);
+		if ((m->m_flags & M_EXT) == 0) {
+			m_free(m);
+			m = NULL;
+		}
+	}
+	if (m == NULL)
+		return;
+	m->m_pkthdr.rcvif = NULL;
+
+	bzero(&ro, sizeof(ro));
+
+	if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
+		m->m_flags |= M_MCAST;
+		im6o.im6o_multicast_ifp = ifp;
+		im6o.im6o_multicast_hlim = 255;
+		im6o.im6o_multicast_loop = 0;
+	}
+
+	icmp6len = sizeof(*nd_ns);
+	m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
+	m->m_data += max_linkhdr;	/* or MH_ALIGN() equivalent? */
+
+	/* fill neighbor solicitation packet */
+	ip6 = mtod(m, struct ip6_hdr *);
+	ip6->ip6_flow = 0;
+	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
+	ip6->ip6_vfc |= IPV6_VERSION;
+	/* ip6->ip6_plen will be set later */
+	ip6->ip6_nxt = IPPROTO_ICMPV6;
+	ip6->ip6_hlim = 255;
+	if (daddr6)
+		ip6->ip6_dst = *daddr6;
+	else {
+		ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
+		ip6->ip6_dst.s6_addr16[1] = 0;
+		ip6->ip6_dst.s6_addr32[1] = 0;
+		ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
+		ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
+		ip6->ip6_dst.s6_addr8[12] = 0xff;
+		if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
+			goto bad;
+	}
+	if (!dad) {
+		struct ifaddr *ifa;
+
+		/*
+		 * RFC2461 7.2.2:
+		 * "If the source address of the packet prompting the
+		 * solicitation is the same as one of the addresses assigned
+		 * to the outgoing interface, that address SHOULD be placed
+		 * in the IP Source Address of the outgoing solicitation.
+		 * Otherwise, any one of the addresses assigned to the
+		 * interface should be used."
+		 *
+		 * We use the source address for the prompting packet
+		 * (saddr6), if:
+		 * - saddr6 is given from the caller (by giving "ln"), and
+		 * - saddr6 belongs to the outgoing interface.
+		 * Otherwise, we perform the source address selection as usual.
+		 */
+		struct in6_addr *hsrc;
+
+		hsrc = NULL;
+		if (ln != NULL) {
+			LLE_RLOCK(ln);
+			if (ln->la_hold != NULL) {
+				struct ip6_hdr *hip6;		/* hold ip6 */
+
+				/*
+				 * assuming every packet in la_hold has the same IP
+				 * header
+				 */
+				hip6 = mtod(ln->la_hold, struct ip6_hdr *);
+				/* XXX pullup? */
+				if (sizeof(*hip6) < ln->la_hold->m_len) {
+					ip6->ip6_src = hip6->ip6_src;
+					hsrc = &hip6->ip6_src;
+				}
+			}
+			LLE_RUNLOCK(ln);
+		}
+		if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
+		    hsrc)) != NULL) {
+			/* ip6_src set already. */
+			ifa_free(ifa);
+		} else {
+			int error;
+			struct sockaddr_in6 dst_sa;
+			struct in6_addr src_in;
+
+			bzero(&dst_sa, sizeof(dst_sa));
+			dst_sa.sin6_family = AF_INET6;
+			dst_sa.sin6_len = sizeof(dst_sa);
+			dst_sa.sin6_addr = ip6->ip6_dst;
+
+			error = in6_selectsrc(&dst_sa, NULL,
+			    NULL, &ro, NULL, NULL, &src_in);
+			if (error) {
+				char ip6buf[INET6_ADDRSTRLEN];
+				nd6log((LOG_DEBUG,
+				    "nd6_ns_output: source can't be "
+				    "determined: dst=%s, error=%d\n",
+				    ip6_sprintf(ip6buf, &dst_sa.sin6_addr),
+				    error));
+				goto bad;
+			}
+			ip6->ip6_src = src_in;
+		}
+	} else {
+		/*
+		 * Source address for DAD packet must always be IPv6
+		 * unspecified address. (0::0)
+		 * We actually don't have to 0-clear the address (we did it
+		 * above), but we do so here explicitly to make the intention
+		 * clearer.
+		 */
+		bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
+	}
+	nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
+	nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
+	nd_ns->nd_ns_code = 0;
+	nd_ns->nd_ns_reserved = 0;
+	nd_ns->nd_ns_target = *taddr6;
+	in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
+
+	/*
+	 * Add source link-layer address option.
+	 *
+	 *				spec		implementation
+	 *				---		---
+	 * DAD packet			MUST NOT	do not add the option
+	 * there's no link layer address:
+	 *				impossible	do not add the option
+	 * there's link layer address:
+	 *	Multicast NS		MUST add one	add the option
+	 *	Unicast NS		SHOULD add one	add the option
+	 */
+	if (!dad && (mac = nd6_ifptomac(ifp))) {
+		int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
+		struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
+		/* 8 byte alignments... */
+		optlen = (optlen + 7) & ~7;
+
+		m->m_pkthdr.len += optlen;
+		m->m_len += optlen;
+		icmp6len += optlen;
+		bzero((caddr_t)nd_opt, optlen);
+		nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
+		nd_opt->nd_opt_len = optlen >> 3;
+		bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
+	}
+
+	ip6->ip6_plen = htons((u_short)icmp6len);
+	nd_ns->nd_ns_cksum = 0;
+	nd_ns->nd_ns_cksum =
+	    in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
+
+	ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
+	icmp6_ifstat_inc(ifp, ifs6_out_msg);
+	icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
+	ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
+
+	if (ro.ro_rt) {		/* we don't cache this route. */
+		RTFREE(ro.ro_rt);
+	}
+	return;
+
+  bad:
+	if (ro.ro_rt) {
+		RTFREE(ro.ro_rt);
+	}
+	m_freem(m);
+	return;
+}
+
+/*
+ * Neighbor advertisement input handling.
+ *
+ * Based on RFC 2461
+ * Based on RFC 2462 (duplicate address detection)
+ *
+ * the following items are not implemented yet:
+ * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
+ * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
+ */
+void
+nd6_na_input(struct mbuf *m, int off, int icmp6len)
+{
+	struct ifnet *ifp = m->m_pkthdr.rcvif;
+	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
+	struct nd_neighbor_advert *nd_na;
+	struct in6_addr daddr6 = ip6->ip6_dst;
+	struct in6_addr taddr6;
+	int flags;
+	int is_router;
+	int is_solicited;
+	int is_override;
+	char *lladdr = NULL;
+	int lladdrlen = 0;
+	int checklink = 0;
+	struct ifaddr *ifa;
+	struct llentry *ln = NULL;
+	union nd_opts ndopts;
+	struct mbuf *chain = NULL;
+	struct sockaddr_in6 sin6;
+	char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
+
+	if (ip6->ip6_hlim != 255) {
+		nd6log((LOG_ERR,
+		    "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
+		    ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
+		    ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
+		goto bad;
+	}
+
+#ifndef PULLDOWN_TEST
+	IP6_EXTHDR_CHECK(m, off, icmp6len,);
+	nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
+#else
+	IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
+	if (nd_na == NULL) {
+		ICMP6STAT_INC(icp6s_tooshort);
+		return;
+	}
+#endif
+
+	flags = nd_na->nd_na_flags_reserved;
+	is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
+	is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
+	is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
+
+	taddr6 = nd_na->nd_na_target;
+	if (in6_setscope(&taddr6, ifp, NULL))
+		goto bad;	/* XXX: impossible */
+
+	if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
+		nd6log((LOG_ERR,
+		    "nd6_na_input: invalid target address %s\n",
+		    ip6_sprintf(ip6bufs, &taddr6)));
+		goto bad;
+	}
+	if (IN6_IS_ADDR_MULTICAST(&daddr6))
+		if (is_solicited) {
+			nd6log((LOG_ERR,
+			    "nd6_na_input: a solicited adv is multicasted\n"));
+			goto bad;
+		}
+
+	icmp6len -= sizeof(*nd_na);
+	nd6_option_init(nd_na + 1, icmp6len, &ndopts);
+	if (nd6_options(&ndopts) < 0) {
+		nd6log((LOG_INFO,
+		    "nd6_na_input: invalid ND option, ignored\n"));
+		/* nd6_options have incremented stats */
+		goto freeit;
+	}
+
+	if (ndopts.nd_opts_tgt_lladdr) {
+		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
+		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
+	}
+
+	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
+
+	/*
+	 * Target address matches one of my interface address.
+	 *
+	 * If my address is tentative, this means that there's somebody
+	 * already using the same address as mine.  This indicates DAD failure.
+	 * This is defined in RFC 2462.
+	 *
+	 * Otherwise, process as defined in RFC 2461.
+	 */
+	if (ifa
+	 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
+		ifa_free(ifa);
+		nd6_dad_na_input(ifa);
+		goto freeit;
+	}
+
+	/* Just for safety, maybe unnecessary. */
+	if (ifa) {
+		ifa_free(ifa);
+		log(LOG_ERR,
+		    "nd6_na_input: duplicate IP6 address %s\n",
+		    ip6_sprintf(ip6bufs, &taddr6));
+		goto freeit;
+	}
+
+	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
+		nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
+		    "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
+		    ifp->if_addrlen, lladdrlen - 2));
+		goto bad;
+	}
+
+	/*
+	 * If no neighbor cache entry is found, NA SHOULD silently be
+	 * discarded.
+	 */
+	IF_AFDATA_LOCK(ifp);
+	ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
+	IF_AFDATA_UNLOCK(ifp);
+	if (ln == NULL) {
+		goto freeit;
+	}
+
+	if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
+		/*
+		 * If the link-layer has address, and no lladdr option came,
+		 * discard the packet.
+		 */
+		if (ifp->if_addrlen && lladdr == NULL) {
+			goto freeit;
+		}
+
+		/*
+		 * Record link-layer address, and update the state.
+		 */
+		bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
+		ln->la_flags |= LLE_VALID;
+		if (is_solicited) {
+			ln->ln_state = ND6_LLINFO_REACHABLE;
+			ln->ln_byhint = 0;
+			if (!ND6_LLINFO_PERMANENT(ln)) {
+				nd6_llinfo_settimer_locked(ln,
+				    (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz);
+			}
+		} else {
+			ln->ln_state = ND6_LLINFO_STALE;
+			nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
+		}
+		if ((ln->ln_router = is_router) != 0) {
+			/*
+			 * This means a router's state has changed from
+			 * non-reachable to probably reachable, and might
+			 * affect the status of associated prefixes..
+			 */
+			checklink = 1;
+		}
+	} else {
+		int llchange;
+
+		/*
+		 * Check if the link-layer address has changed or not.
+		 */
+		if (lladdr == NULL)
+			llchange = 0;
+		else {
+			if (ln->la_flags & LLE_VALID) {
+				if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen))
+					llchange = 1;
+				else
+					llchange = 0;
+			} else
+				llchange = 1;
+		}
+
+		/*
+		 * This is VERY complex.  Look at it with care.
+		 *
+		 * override solicit lladdr llchange	action
+		 *					(L: record lladdr)
+		 *
+		 *	0	0	n	--	(2c)
+		 *	0	0	y	n	(2b) L
+		 *	0	0	y	y	(1)    REACHABLE->STALE
+		 *	0	1	n	--	(2c)   *->REACHABLE
+		 *	0	1	y	n	(2b) L *->REACHABLE
+		 *	0	1	y	y	(1)    REACHABLE->STALE
+		 *	1	0	n	--	(2a)
+		 *	1	0	y	n	(2a) L
+		 *	1	0	y	y	(2a) L *->STALE
+		 *	1	1	n	--	(2a)   *->REACHABLE
+		 *	1	1	y	n	(2a) L *->REACHABLE
+		 *	1	1	y	y	(2a) L *->REACHABLE
+		 */
+		if (!is_override && (lladdr != NULL && llchange)) {  /* (1) */
+			/*
+			 * If state is REACHABLE, make it STALE.
+			 * no other updates should be done.
+			 */
+			if (ln->ln_state == ND6_LLINFO_REACHABLE) {
+				ln->ln_state = ND6_LLINFO_STALE;
+				nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
+			}
+			goto freeit;
+		} else if (is_override				   /* (2a) */
+			|| (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
+			|| lladdr == NULL) {			   /* (2c) */
+			/*
+			 * Update link-local address, if any.
+			 */
+			if (lladdr != NULL) {
+				bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
+				ln->la_flags |= LLE_VALID;
+			}
+
+			/*
+			 * If solicited, make the state REACHABLE.
+			 * If not solicited and the link-layer address was
+			 * changed, make it STALE.
+			 */
+			if (is_solicited) {
+				ln->ln_state = ND6_LLINFO_REACHABLE;
+				ln->ln_byhint = 0;
+				if (!ND6_LLINFO_PERMANENT(ln)) {
+					nd6_llinfo_settimer_locked(ln,
+					    (long)ND_IFINFO(ifp)->reachable * hz);
+				}
+			} else {
+				if (lladdr != NULL && llchange) {
+					ln->ln_state = ND6_LLINFO_STALE;
+					nd6_llinfo_settimer_locked(ln,
+					    (long)V_nd6_gctimer * hz);
+				}
+			}
+		}
+
+		if (ln->ln_router && !is_router) {
+			/*
+			 * The peer dropped the router flag.
+			 * Remove the sender from the Default Router List and
+			 * update the Destination Cache entries.
+			 */
+			struct nd_defrouter *dr;
+			struct in6_addr *in6;
+
+			in6 = &L3_ADDR_SIN6(ln)->sin6_addr;
+
+			/*
+			 * Lock to protect the default router list.
+			 * XXX: this might be unnecessary, since this function
+			 * is only called under the network software interrupt
+			 * context.  However, we keep it just for safety.
+			 */
+			dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp);
+			if (dr)
+				defrtrlist_del(dr);
+			else if (!V_ip6_forwarding) {
+				/*
+				 * Even if the neighbor is not in the default
+				 * router list, the neighbor may be used
+				 * as a next hop for some destinations
+				 * (e.g. redirect case). So we must
+				 * call rt6_flush explicitly.
+				 */
+				rt6_flush(&ip6->ip6_src, ifp);
+			}
+		}
+		ln->ln_router = is_router;
+	}
+        /* XXX - QL
+	 *  Does this matter?
+	 *  rt->rt_flags &= ~RTF_REJECT;
+	 */
+	ln->la_asked = 0;
+	if (ln->la_hold) {
+		struct mbuf *m_hold, *m_hold_next;
+
+		/*
+		 * reset the la_hold in advance, to explicitly
+		 * prevent a la_hold lookup in nd6_output()
+		 * (wouldn't happen, though...)
+		 */
+		for (m_hold = ln->la_hold, ln->la_hold = NULL;
+		    m_hold; m_hold = m_hold_next) {
+			m_hold_next = m_hold->m_nextpkt;
+			m_hold->m_nextpkt = NULL;
+			/*
+			 * we assume ifp is not a loopback here, so just set
+			 * the 2nd argument as the 1st one.
+			 */
+			nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
+		}
+	}
+ freeit:
+	if (ln != NULL) {
+		if (chain)
+			memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
+		LLE_WUNLOCK(ln);
+
+		if (chain)
+			nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
+	}
+	if (checklink)
+		pfxlist_onlink_check();
+
+	m_freem(m);
+	return;
+
+ bad:
+	if (ln != NULL)
+		LLE_WUNLOCK(ln);
+
+	ICMP6STAT_INC(icp6s_badna);
+	m_freem(m);
+}
+
+/*
+ * Neighbor advertisement output handling.
+ *
+ * Based on RFC 2461
+ *
+ * the following items are not implemented yet:
+ * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
+ * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
+ *
+ * tlladdr - 1 if include target link-layer address
+ * sdl0 - sockaddr_dl (= proxy NA) or NULL
+ */
+void
+nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
+    const struct in6_addr *taddr6, u_long flags, int tlladdr,
+    struct sockaddr *sdl0)
+{
+	struct mbuf *m;
+	struct ip6_hdr *ip6;
+	struct nd_neighbor_advert *nd_na;
+	struct ip6_moptions im6o;
+	struct in6_addr src, daddr6;
+	struct sockaddr_in6 dst_sa;
+	int icmp6len, maxlen, error;
+	caddr_t mac = NULL;
+	struct route_in6 ro;
+
+	bzero(&ro, sizeof(ro));
+
+	daddr6 = *daddr6_0;	/* make a local copy for modification */
+
+	/* estimate the size of message */
+	maxlen = sizeof(*ip6) + sizeof(*nd_na);
+	maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
+	if (max_linkhdr + maxlen >= MCLBYTES) {
+#ifdef DIAGNOSTIC
+		printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
+		    "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
+#endif
+		return;
+	}
+
+	MGETHDR(m, M_DONTWAIT, MT_DATA);
+	if (m && max_linkhdr + maxlen >= MHLEN) {
+		MCLGET(m, M_DONTWAIT);
+		if ((m->m_flags & M_EXT) == 0) {
+			m_free(m);
+			m = NULL;
+		}
+	}
+	if (m == NULL)
+		return;
+	m->m_pkthdr.rcvif = NULL;
+
+	if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
+		m->m_flags |= M_MCAST;
+		im6o.im6o_multicast_ifp = ifp;
+		im6o.im6o_multicast_hlim = 255;
+		im6o.im6o_multicast_loop = 0;
+	}
+
+	icmp6len = sizeof(*nd_na);
+	m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
+	m->m_data += max_linkhdr;	/* or MH_ALIGN() equivalent? */
+
+	/* fill neighbor advertisement packet */
+	ip6 = mtod(m, struct ip6_hdr *);
+	ip6->ip6_flow = 0;
+	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
+	ip6->ip6_vfc |= IPV6_VERSION;
+	ip6->ip6_nxt = IPPROTO_ICMPV6;
+	ip6->ip6_hlim = 255;
+	if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
+		/* reply to DAD */
+		daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
+		daddr6.s6_addr16[1] = 0;
+		daddr6.s6_addr32[1] = 0;
+		daddr6.s6_addr32[2] = 0;
+		daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
+		if (in6_setscope(&daddr6, ifp, NULL))
+			goto bad;
+
+		flags &= ~ND_NA_FLAG_SOLICITED;
+	}
+	ip6->ip6_dst = daddr6;
+	bzero(&dst_sa, sizeof(struct sockaddr_in6));
+	dst_sa.sin6_family = AF_INET6;
+	dst_sa.sin6_len = sizeof(struct sockaddr_in6);
+	dst_sa.sin6_addr = daddr6;
+
+	/*
+	 * Select a source whose scope is the same as that of the dest.
+	 */
+	bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
+	error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, NULL, &src);
+	if (error) {
+		char ip6buf[INET6_ADDRSTRLEN];
+		nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
+		    "determined: dst=%s, error=%d\n",
+		    ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error));
+		goto bad;
+	}
+	ip6->ip6_src = src;
+	nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
+	nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
+	nd_na->nd_na_code = 0;
+	nd_na->nd_na_target = *taddr6;
+	in6_clearscope(&nd_na->nd_na_target); /* XXX */
+
+	/*
+	 * "tlladdr" indicates NS's condition for adding tlladdr or not.
+	 * see nd6_ns_input() for details.
+	 * Basically, if NS packet is sent to unicast/anycast addr,
+	 * target lladdr option SHOULD NOT be included.
+	 */
+	if (tlladdr) {
+		/*
+		 * sdl0 != NULL indicates proxy NA.  If we do proxy, use
+		 * lladdr in sdl0.  If we are not proxying (sending NA for
+		 * my address) use lladdr configured for the interface.
+		 */
+		if (sdl0 == NULL) {
+			if (ifp->if_carp)
+				mac = (*carp_macmatch6_p)(ifp, m, taddr6);
+			if (mac == NULL)
+				mac = nd6_ifptomac(ifp);
+		} else if (sdl0->sa_family == AF_LINK) {
+			struct sockaddr_dl *sdl;
+			sdl = (struct sockaddr_dl *)sdl0;
+			if (sdl->sdl_alen == ifp->if_addrlen)
+				mac = LLADDR(sdl);
+		}
+	}
+	if (tlladdr && mac) {
+		int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
+		struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
+
+		/* roundup to 8 bytes alignment! */
+		optlen = (optlen + 7) & ~7;
+
+		m->m_pkthdr.len += optlen;
+		m->m_len += optlen;
+		icmp6len += optlen;
+		bzero((caddr_t)nd_opt, optlen);
+		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
+		nd_opt->nd_opt_len = optlen >> 3;
+		bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
+	} else
+		flags &= ~ND_NA_FLAG_OVERRIDE;
+
+	ip6->ip6_plen = htons((u_short)icmp6len);
+	nd_na->nd_na_flags_reserved = flags;
+	nd_na->nd_na_cksum = 0;
+	nd_na->nd_na_cksum =
+	    in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
+
+	ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL);
+	icmp6_ifstat_inc(ifp, ifs6_out_msg);
+	icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
+	ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
+
+	if (ro.ro_rt) {		/* we don't cache this route. */
+		RTFREE(ro.ro_rt);
+	}
+	return;
+
+  bad:
+	if (ro.ro_rt) {
+		RTFREE(ro.ro_rt);
+	}
+	m_freem(m);
+	return;
+}
+
+caddr_t
+nd6_ifptomac(struct ifnet *ifp)
+{
+	switch (ifp->if_type) {
+	case IFT_ARCNET:
+	case IFT_ETHER:
+	case IFT_FDDI:
+	case IFT_IEEE1394:
+#ifdef IFT_L2VLAN
+	case IFT_L2VLAN:
+#endif
+#ifdef IFT_IEEE80211
+	case IFT_IEEE80211:
+#endif
+#ifdef IFT_CARP
+	case IFT_CARP:
+#endif
+	case IFT_BRIDGE:
+	case IFT_ISO88025:
+		return IF_LLADDR(ifp);
+	default:
+		return NULL;
+	}
+}
+
+struct dadq {
+	TAILQ_ENTRY(dadq) dad_list;
+	struct ifaddr *dad_ifa;
+	int dad_count;		/* max NS to send */
+	int dad_ns_tcount;	/* # of trials to send NS */
+	int dad_ns_ocount;	/* NS sent so far */
+	int dad_ns_icount;
+	int dad_na_icount;
+	struct callout dad_timer_ch;
+	struct vnet *dad_vnet;
+};
+
+static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
+VNET_DEFINE(int, dad_init) = 0;
+#define	V_dadq				VNET(dadq)
+#define	V_dad_init			VNET(dad_init)
+
+static struct dadq *
+nd6_dad_find(struct ifaddr *ifa)
+{
+	struct dadq *dp;
+
+	for (dp = V_dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
+		if (dp->dad_ifa == ifa)
+			return dp;
+	}
+	return NULL;
+}
+
+static void
+nd6_dad_starttimer(struct dadq *dp, int ticks)
+{
+
+	callout_reset(&dp->dad_timer_ch, ticks,
+	    (void (*)(void *))nd6_dad_timer, (void *)dp);
+}
+
+static void
+nd6_dad_stoptimer(struct dadq *dp)
+{
+
+	callout_stop(&dp->dad_timer_ch);
+}
+
+/*
+ * Start Duplicate Address Detection (DAD) for specified interface address.
+ */
+void
+nd6_dad_start(struct ifaddr *ifa, int delay)
+{
+	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
+	struct dadq *dp;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	if (!V_dad_init) {
+		TAILQ_INIT(&V_dadq);
+		V_dad_init++;
+	}
+
+	/*
+	 * If we don't need DAD, don't do it.
+	 * There are several cases:
+	 * - DAD is disabled (ip6_dad_count == 0)
+	 * - the interface address is anycast
+	 */
+	if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
+		log(LOG_DEBUG,
+			"nd6_dad_start: called with non-tentative address "
+			"%s(%s)\n",
+			ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
+			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
+		return;
+	}
+	if (ia->ia6_flags & IN6_IFF_ANYCAST) {
+		ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
+		return;
+	}
+	if (!V_ip6_dad_count) {
+		ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
+		return;
+	}
+	if (ifa->ifa_ifp == NULL)
+		panic("nd6_dad_start: ifa->ifa_ifp == NULL");
+	if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
+		return;
+	}
+	if (nd6_dad_find(ifa) != NULL) {
+		/* DAD already in progress */
+		return;
+	}
+
+	dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
+	if (dp == NULL) {
+		log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
+			"%s(%s)\n",
+			ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
+			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
+		return;
+	}
+	bzero(dp, sizeof(*dp));
+	callout_init(&dp->dad_timer_ch, 0);
+#ifdef VIMAGE
+	dp->dad_vnet = curvnet;
+#endif
+	TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list);
+
+	nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
+	    ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
+
+	/*
+	 * Send NS packet for DAD, ip6_dad_count times.
+	 * Note that we must delay the first transmission, if this is the
+	 * first packet to be sent from the interface after interface
+	 * (re)initialization.
+	 */
+	dp->dad_ifa = ifa;
+	ifa_ref(ifa);	/* just for safety */
+	dp->dad_count = V_ip6_dad_count;
+	dp->dad_ns_icount = dp->dad_na_icount = 0;
+	dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
+	if (delay == 0) {
+		nd6_dad_ns_output(dp, ifa);
+		nd6_dad_starttimer(dp,
+		    (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
+	} else {
+		nd6_dad_starttimer(dp, delay);
+	}
+}
+
+/*
+ * terminate DAD unconditionally.  used for address removals.
+ */
+void
+nd6_dad_stop(struct ifaddr *ifa)
+{
+	struct dadq *dp;
+
+	if (!V_dad_init)
+		return;
+	dp = nd6_dad_find(ifa);
+	if (!dp) {
+		/* DAD wasn't started yet */
+		return;
+	}
+
+	nd6_dad_stoptimer(dp);
+
+	TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
+	free(dp, M_IP6NDP);
+	dp = NULL;
+	ifa_free(ifa);
+}
+
+static void
+nd6_dad_timer(struct dadq *dp)
+{
+	CURVNET_SET(dp->dad_vnet);
+	int s;
+	struct ifaddr *ifa = dp->dad_ifa;
+	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	s = splnet();		/* XXX */
+
+	/* Sanity check */
+	if (ia == NULL) {
+		log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
+		goto done;
+	}
+	if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
+		log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
+			"%s(%s)\n",
+			ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
+			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
+		goto done;
+	}
+	if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
+		log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
+			"%s(%s)\n",
+			ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
+			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
+		goto done;
+	}
+
+	/* timeouted with IFF_{RUNNING,UP} check */
+	if (dp->dad_ns_tcount > V_dad_maxtry) {
+		nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
+		    if_name(ifa->ifa_ifp)));
+
+		TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
+		free(dp, M_IP6NDP);
+		dp = NULL;
+		ifa_free(ifa);
+		goto done;
+	}
+
+	/* Need more checks? */
+	if (dp->dad_ns_ocount < dp->dad_count) {
+		/*
+		 * We have more NS to go.  Send NS packet for DAD.
+		 */
+		nd6_dad_ns_output(dp, ifa);
+		nd6_dad_starttimer(dp,
+		    (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
+	} else {
+		/*
+		 * We have transmitted sufficient number of DAD packets.
+		 * See what we've got.
+		 */
+		int duplicate;
+
+		duplicate = 0;
+
+		if (dp->dad_na_icount) {
+			/*
+			 * the check is in nd6_dad_na_input(),
+			 * but just in case
+			 */
+			duplicate++;
+		}
+
+		if (dp->dad_ns_icount) {
+			/* We've seen NS, means DAD has failed. */
+			duplicate++;
+		}
+
+		if (duplicate) {
+			/* (*dp) will be freed in nd6_dad_duplicated() */
+			dp = NULL;
+			nd6_dad_duplicated(ifa);
+		} else {
+			/*
+			 * We are done with DAD.  No NA came, no NS came.
+			 * No duplicate address found.
+			 */
+			ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
+
+			nd6log((LOG_DEBUG,
+			    "%s: DAD complete for %s - no duplicates found\n",
+			    if_name(ifa->ifa_ifp),
+			    ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
+
+			TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
+			free(dp, M_IP6NDP);
+			dp = NULL;
+			ifa_free(ifa);
+		}
+	}
+
+done:
+	splx(s);
+	CURVNET_RESTORE();
+}
+
+void
+nd6_dad_duplicated(struct ifaddr *ifa)
+{
+	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
+	struct ifnet *ifp;
+	struct dadq *dp;
+	char ip6buf[INET6_ADDRSTRLEN];
+
+	dp = nd6_dad_find(ifa);
+	if (dp == NULL) {
+		log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
+		return;
+	}
+
+	log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
+	    "NS in/out=%d/%d, NA in=%d\n",
+	    if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
+	    dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
+
+	ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
+	ia->ia6_flags |= IN6_IFF_DUPLICATED;
+
+	/* We are done with DAD, with duplicate address found. (failure) */
+	nd6_dad_stoptimer(dp);
+
+	ifp = ifa->ifa_ifp;
+	log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
+	    if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
+	log(LOG_ERR, "%s: manual intervention required\n",
+	    if_name(ifp));
+
+	/*
+	 * If the address is a link-local address formed from an interface
+	 * identifier based on the hardware address which is supposed to be
+	 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
+	 * operation on the interface SHOULD be disabled.
+	 * [rfc2462bis-03 Section 5.4.5]
+	 */
+	if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
+		struct in6_addr in6;
+
+		/*
+		 * To avoid over-reaction, we only apply this logic when we are
+		 * very sure that hardware addresses are supposed to be unique.
+		 */
+		switch (ifp->if_type) {
+		case IFT_ETHER:
+		case IFT_FDDI:
+		case IFT_ATM:
+		case IFT_IEEE1394:
+#ifdef IFT_IEEE80211
+		case IFT_IEEE80211:
+#endif
+			in6 = ia->ia_addr.sin6_addr;
+			if (in6_get_hw_ifid(ifp, &in6) == 0 &&
+			    IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
+				ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
+				log(LOG_ERR, "%s: possible hardware address "
+				    "duplication detected, disable IPv6\n",
+				    if_name(ifp));
+			}
+			break;
+		}
+	}
+
+	TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
+	free(dp, M_IP6NDP);
+	dp = NULL;
+	ifa_free(ifa);
+}
+
+static void
+nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
+{
+	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
+	struct ifnet *ifp = ifa->ifa_ifp;
+
+	dp->dad_ns_tcount++;
+	if ((ifp->if_flags & IFF_UP) == 0) {
+		return;
+	}
+	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
+		return;
+	}
+
+	dp->dad_ns_ocount++;
+	nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
+}
+
+static void
+nd6_dad_ns_input(struct ifaddr *ifa)
+{
+	struct in6_ifaddr *ia;
+	struct ifnet *ifp;
+	const struct in6_addr *taddr6;
+	struct dadq *dp;
+	int duplicate;
+
+	if (ifa == NULL)
+		panic("ifa == NULL in nd6_dad_ns_input");
+
+	ia = (struct in6_ifaddr *)ifa;
+	ifp = ifa->ifa_ifp;
+	taddr6 = &ia->ia_addr.sin6_addr;
+	duplicate = 0;
+	dp = nd6_dad_find(ifa);
+
+	/* Quickhack - completely ignore DAD NS packets */
+	if (V_dad_ignore_ns) {
+		char ip6buf[INET6_ADDRSTRLEN];
+		nd6log((LOG_INFO,
+		    "nd6_dad_ns_input: ignoring DAD NS packet for "
+		    "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6),
+		    if_name(ifa->ifa_ifp)));
+		return;
+	}
+
+	/*
+	 * if I'm yet to start DAD, someone else started using this address
+	 * first.  I have a duplicate and you win.
+	 */
+	if (dp == NULL || dp->dad_ns_ocount == 0)
+		duplicate++;
+
+	/* XXX more checks for loopback situation - see nd6_dad_timer too */
+
+	if (duplicate) {
+		dp = NULL;	/* will be freed in nd6_dad_duplicated() */
+		nd6_dad_duplicated(ifa);
+	} else {
+		/*
+		 * not sure if I got a duplicate.
+		 * increment ns count and see what happens.
+		 */
+		if (dp)
+			dp->dad_ns_icount++;
+	}
+}
+
+static void
+nd6_dad_na_input(struct ifaddr *ifa)
+{
+	struct dadq *dp;
+
+	if (ifa == NULL)
+		panic("ifa == NULL in nd6_dad_na_input");
+
+	dp = nd6_dad_find(ifa);
+	if (dp)
+		dp->dad_na_icount++;
+
+	/* remove the address. */
+	nd6_dad_duplicated(ifa);
+}