2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
36 #include "opt_inet6.h"
37 #include "opt_ipsec.h"
38 #include "opt_mpath.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
44 #include <sys/rwlock.h>
46 #include <sys/socket.h>
47 #include <sys/sockio.h>
49 #include <sys/kernel.h>
50 #include <sys/errno.h>
51 #include <sys/syslog.h>
52 #include <sys/queue.h>
53 #include <sys/callout.h>
56 #include <net/if_types.h>
57 #include <net/if_dl.h>
58 #include <net/if_var.h>
59 #include <net/route.h>
61 #include <net/radix_mpath.h>
64 #include <netinet/in.h>
65 #include <netinet/in_var.h>
66 #include <net/if_llatbl.h>
67 #define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le))
68 #include <netinet6/in6_var.h>
69 #include <netinet6/in6_ifattach.h>
70 #include <netinet/ip6.h>
71 #include <netinet6/ip6_var.h>
72 #include <netinet6/scope6_var.h>
73 #include <netinet6/nd6.h>
74 #include <netinet/icmp6.h>
75 #include <netinet/ip_carp.h>
76 #include <netinet6/send.h>
78 #define SDL(s) ((struct sockaddr_dl *)s)
81 static struct dadq *nd6_dad_find(struct ifaddr *);
82 static void nd6_dad_starttimer(struct dadq *, int);
83 static void nd6_dad_stoptimer(struct dadq *);
84 static void nd6_dad_timer(struct dadq *);
85 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
86 static void nd6_dad_ns_input(struct ifaddr *);
87 static void nd6_dad_na_input(struct ifaddr *);
89 VNET_DEFINE(int, dad_ignore_ns) = 0; /* ignore NS in DAD - specwise incorrect*/
90 VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to transmit DAD packet */
91 #define V_dad_ignore_ns VNET(dad_ignore_ns)
92 #define V_dad_maxtry VNET(dad_maxtry)
95 * Input a Neighbor Solicitation Message.
98 * Based on RFC 2462 (duplicate address detection)
101 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
103 struct ifnet *ifp = m->m_pkthdr.rcvif;
104 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
105 struct nd_neighbor_solicit *nd_ns;
106 struct in6_addr saddr6 = ip6->ip6_src;
107 struct in6_addr daddr6 = ip6->ip6_dst;
108 struct in6_addr taddr6;
109 struct in6_addr myaddr6;
111 struct ifaddr *ifa = NULL;
113 int anycast = 0, proxy = 0, tentative = 0;
116 union nd_opts ndopts;
117 struct sockaddr_dl proxydl;
118 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
120 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
121 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
123 #ifndef PULLDOWN_TEST
124 IP6_EXTHDR_CHECK(m, off, icmp6len,);
125 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
127 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
129 ICMP6STAT_INC(icp6s_tooshort);
133 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
134 taddr6 = nd_ns->nd_ns_target;
135 if (in6_setscope(&taddr6, ifp, NULL) != 0)
138 if (ip6->ip6_hlim != 255) {
140 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
141 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
142 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
146 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
147 /* dst has to be a solicited node multicast address. */
148 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
149 /* don't check ifindex portion */
150 daddr6.s6_addr32[1] == 0 &&
151 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
152 daddr6.s6_addr8[12] == 0xff) {
155 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
156 "(wrong ip6 dst)\n"));
159 } else if (!V_nd6_onlink_ns_rfc4861) {
160 struct sockaddr_in6 src_sa6;
163 * According to recent IETF discussions, it is not a good idea
164 * to accept a NS from an address which would not be deemed
165 * to be a neighbor otherwise. This point is expected to be
166 * clarified in future revisions of the specification.
168 bzero(&src_sa6, sizeof(src_sa6));
169 src_sa6.sin6_family = AF_INET6;
170 src_sa6.sin6_len = sizeof(src_sa6);
171 src_sa6.sin6_addr = saddr6;
172 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
173 nd6log((LOG_INFO, "nd6_ns_input: "
174 "NS packet from non-neighbor\n"));
179 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
180 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
184 icmp6len -= sizeof(*nd_ns);
185 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
186 if (nd6_options(&ndopts) < 0) {
188 "nd6_ns_input: invalid ND option, ignored\n"));
189 /* nd6_options have incremented stats */
193 if (ndopts.nd_opts_src_lladdr) {
194 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
195 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
198 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
199 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
200 "(link-layer address option)\n"));
205 * Attaching target link-layer address to the NA?
208 * NS IP dst is unicast/anycast MUST NOT add
209 * NS IP dst is solicited-node multicast MUST add
211 * In implementation, we add target link-layer address by default.
212 * We do not add one in MUST NOT cases.
214 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
220 * Target address (taddr6) must be either:
221 * (1) Valid unicast/anycast address for my receiving interface,
222 * (2) Unicast address for which I'm offering proxy service, or
223 * (3) "tentative" address on which DAD is being performed.
225 /* (1) and (3) check. */
227 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
229 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
234 struct sockaddr_in6 tsin6;
240 bzero(&tsin6, sizeof tsin6);
241 tsin6.sin6_len = sizeof(struct sockaddr_in6);
242 tsin6.sin6_family = AF_INET6;
243 tsin6.sin6_addr = taddr6;
246 bzero(&ro, sizeof(ro));
248 rtalloc_mpath((struct route *)&ro, RTF_ANNOUNCE);
251 rt = rtalloc1((struct sockaddr *)&tsin6, 0, 0);
253 need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
254 rt->rt_gateway->sa_family == AF_LINK);
257 * Make a copy while we can be sure that rt_gateway
258 * is still stable before unlocking to avoid lock
259 * order problems. proxydl will only be used if
260 * proxy will be set in the next block.
263 proxydl = *SDL(rt->rt_gateway);
268 * proxy NDP for single entry
270 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
271 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
278 * We've got an NS packet, and we don't have that adddress
279 * assigned for us. We MUST silently ignore it.
284 myaddr6 = *IFA_IN6(ifa);
285 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
286 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
287 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
290 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
291 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
292 "(if %d, NS packet %d)\n",
293 ip6_sprintf(ip6bufs, &taddr6),
294 ifp->if_addrlen, lladdrlen - 2));
298 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
299 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
300 ip6_sprintf(ip6bufs, &saddr6)));
305 * We have neighbor solicitation packet, with target address equals to
306 * one of my tentative address.
308 * src addr how to process?
310 * multicast of course, invalid (rejected in ip6_input)
311 * unicast somebody is doing address resolution -> ignore
312 * unspec dup address detection
314 * The processing is defined in RFC 2462.
318 * If source address is unspecified address, it is for
319 * duplicate address detection.
321 * If not, the packet is for addess resolution;
322 * silently ignore it.
324 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
325 nd6_dad_ns_input(ifa);
331 * If the source address is unspecified address, entries must not
332 * be created or updated.
333 * It looks that sender is performing DAD. Output NA toward
334 * all-node multicast address, to tell the sender that I'm using
336 * S bit ("solicited") must be zero.
338 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
339 struct in6_addr in6_all;
341 in6_all = in6addr_linklocal_allnodes;
342 if (in6_setscope(&in6_all, ifp, NULL) != 0)
344 nd6_na_output(ifp, &in6_all, &taddr6,
345 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
346 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL);
350 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
351 ND_NEIGHBOR_SOLICIT, 0);
353 nd6_na_output(ifp, &saddr6, &taddr6,
354 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
355 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
356 proxy ? (struct sockaddr *)&proxydl : NULL);
364 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
365 ip6_sprintf(ip6bufs, &saddr6)));
366 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
367 ip6_sprintf(ip6bufs, &daddr6)));
368 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
369 ip6_sprintf(ip6bufs, &taddr6)));
370 ICMP6STAT_INC(icp6s_badns);
377 * Output a Neighbor Solicitation Message. Caller specifies:
378 * - ICMP6 header source IP6 address
379 * - ND6 header target IP6 address
380 * - ND6 header source datalink address
383 * Based on RFC 2462 (duplicate address detection)
385 * ln - for source address determination
386 * dad - duplicate address detection
389 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
390 const struct in6_addr *taddr6, struct llentry *ln, int dad)
395 struct nd_neighbor_solicit *nd_ns;
396 struct ip6_moptions im6o;
402 if (IN6_IS_ADDR_MULTICAST(taddr6))
405 /* estimate the size of message */
406 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
407 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
408 if (max_linkhdr + maxlen >= MCLBYTES) {
410 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
411 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
416 MGETHDR(m, M_DONTWAIT, MT_DATA);
417 if (m && max_linkhdr + maxlen >= MHLEN) {
418 MCLGET(m, M_DONTWAIT);
419 if ((m->m_flags & M_EXT) == 0) {
426 m->m_pkthdr.rcvif = NULL;
428 bzero(&ro, sizeof(ro));
430 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
431 m->m_flags |= M_MCAST;
432 im6o.im6o_multicast_ifp = ifp;
433 im6o.im6o_multicast_hlim = 255;
434 im6o.im6o_multicast_loop = 0;
437 icmp6len = sizeof(*nd_ns);
438 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
439 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
441 /* fill neighbor solicitation packet */
442 ip6 = mtod(m, struct ip6_hdr *);
444 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
445 ip6->ip6_vfc |= IPV6_VERSION;
446 /* ip6->ip6_plen will be set later */
447 ip6->ip6_nxt = IPPROTO_ICMPV6;
450 ip6->ip6_dst = *daddr6;
452 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
453 ip6->ip6_dst.s6_addr16[1] = 0;
454 ip6->ip6_dst.s6_addr32[1] = 0;
455 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
456 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
457 ip6->ip6_dst.s6_addr8[12] = 0xff;
458 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
466 * "If the source address of the packet prompting the
467 * solicitation is the same as one of the addresses assigned
468 * to the outgoing interface, that address SHOULD be placed
469 * in the IP Source Address of the outgoing solicitation.
470 * Otherwise, any one of the addresses assigned to the
471 * interface should be used."
473 * We use the source address for the prompting packet
475 * - saddr6 is given from the caller (by giving "ln"), and
476 * - saddr6 belongs to the outgoing interface.
477 * Otherwise, we perform the source address selection as usual.
479 struct in6_addr *hsrc;
484 if (ln->la_hold != NULL) {
485 struct ip6_hdr *hip6; /* hold ip6 */
488 * assuming every packet in la_hold has the same IP
491 hip6 = mtod(ln->la_hold, struct ip6_hdr *);
493 if (sizeof(*hip6) < ln->la_hold->m_len) {
494 ip6->ip6_src = hip6->ip6_src;
495 hsrc = &hip6->ip6_src;
500 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
502 /* ip6_src set already. */
506 struct sockaddr_in6 dst_sa;
507 struct in6_addr src_in;
509 bzero(&dst_sa, sizeof(dst_sa));
510 dst_sa.sin6_family = AF_INET6;
511 dst_sa.sin6_len = sizeof(dst_sa);
512 dst_sa.sin6_addr = ip6->ip6_dst;
514 error = in6_selectsrc(&dst_sa, NULL,
515 NULL, &ro, NULL, NULL, &src_in);
517 char ip6buf[INET6_ADDRSTRLEN];
519 "nd6_ns_output: source can't be "
520 "determined: dst=%s, error=%d\n",
521 ip6_sprintf(ip6buf, &dst_sa.sin6_addr),
525 ip6->ip6_src = src_in;
529 * Source address for DAD packet must always be IPv6
530 * unspecified address. (0::0)
531 * We actually don't have to 0-clear the address (we did it
532 * above), but we do so here explicitly to make the intention
535 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
537 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
538 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
539 nd_ns->nd_ns_code = 0;
540 nd_ns->nd_ns_reserved = 0;
541 nd_ns->nd_ns_target = *taddr6;
542 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
545 * Add source link-layer address option.
547 * spec implementation
549 * DAD packet MUST NOT do not add the option
550 * there's no link layer address:
551 * impossible do not add the option
552 * there's link layer address:
553 * Multicast NS MUST add one add the option
554 * Unicast NS SHOULD add one add the option
556 if (!dad && (mac = nd6_ifptomac(ifp))) {
557 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
558 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
559 /* 8 byte alignments... */
560 optlen = (optlen + 7) & ~7;
562 m->m_pkthdr.len += optlen;
565 bzero((caddr_t)nd_opt, optlen);
566 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
567 nd_opt->nd_opt_len = optlen >> 3;
568 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
571 ip6->ip6_plen = htons((u_short)icmp6len);
572 nd_ns->nd_ns_cksum = 0;
574 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
576 if (send_sendso_input_hook != NULL) {
577 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
578 sizeof(unsigned short), M_NOWAIT);
581 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
582 m_tag_prepend(m, mtag);
585 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
586 icmp6_ifstat_inc(ifp, ifs6_out_msg);
587 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
588 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
590 if (ro.ro_rt) { /* we don't cache this route. */
604 * Neighbor advertisement input handling.
607 * Based on RFC 2462 (duplicate address detection)
609 * the following items are not implemented yet:
610 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
611 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
614 nd6_na_input(struct mbuf *m, int off, int icmp6len)
616 struct ifnet *ifp = m->m_pkthdr.rcvif;
617 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
618 struct nd_neighbor_advert *nd_na;
619 struct in6_addr daddr6 = ip6->ip6_dst;
620 struct in6_addr taddr6;
629 struct llentry *ln = NULL;
630 union nd_opts ndopts;
631 struct mbuf *chain = NULL;
633 struct sockaddr_in6 sin6;
634 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
636 if (ip6->ip6_hlim != 255) {
638 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
639 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
640 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
644 #ifndef PULLDOWN_TEST
645 IP6_EXTHDR_CHECK(m, off, icmp6len,);
646 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
648 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
650 ICMP6STAT_INC(icp6s_tooshort);
655 flags = nd_na->nd_na_flags_reserved;
656 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
657 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
658 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
660 taddr6 = nd_na->nd_na_target;
661 if (in6_setscope(&taddr6, ifp, NULL))
662 goto bad; /* XXX: impossible */
664 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
666 "nd6_na_input: invalid target address %s\n",
667 ip6_sprintf(ip6bufs, &taddr6)));
670 if (IN6_IS_ADDR_MULTICAST(&daddr6))
673 "nd6_na_input: a solicited adv is multicasted\n"));
677 icmp6len -= sizeof(*nd_na);
678 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
679 if (nd6_options(&ndopts) < 0) {
681 "nd6_na_input: invalid ND option, ignored\n"));
682 /* nd6_options have incremented stats */
686 if (ndopts.nd_opts_tgt_lladdr) {
687 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
688 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
692 * This effectively disables the DAD check on a non-master CARP
696 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
698 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
701 * Target address matches one of my interface address.
703 * If my address is tentative, this means that there's somebody
704 * already using the same address as mine. This indicates DAD failure.
705 * This is defined in RFC 2462.
707 * Otherwise, process as defined in RFC 2461.
710 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
712 nd6_dad_na_input(ifa);
716 /* Just for safety, maybe unnecessary. */
720 "nd6_na_input: duplicate IP6 address %s\n",
721 ip6_sprintf(ip6bufs, &taddr6));
725 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
726 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
727 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
728 ifp->if_addrlen, lladdrlen - 2));
733 * If no neighbor cache entry is found, NA SHOULD silently be
737 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
738 IF_AFDATA_UNLOCK(ifp);
743 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
745 * If the link-layer has address, and no lladdr option came,
746 * discard the packet.
748 if (ifp->if_addrlen && lladdr == NULL) {
753 * Record link-layer address, and update the state.
755 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
756 ln->la_flags |= LLE_VALID;
758 ln->ln_state = ND6_LLINFO_REACHABLE;
760 if (!ND6_LLINFO_PERMANENT(ln)) {
761 nd6_llinfo_settimer_locked(ln,
762 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz);
765 ln->ln_state = ND6_LLINFO_STALE;
766 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
768 if ((ln->ln_router = is_router) != 0) {
770 * This means a router's state has changed from
771 * non-reachable to probably reachable, and might
772 * affect the status of associated prefixes..
780 * Check if the link-layer address has changed or not.
785 if (ln->la_flags & LLE_VALID) {
786 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen))
795 * This is VERY complex. Look at it with care.
797 * override solicit lladdr llchange action
802 * 0 0 y y (1) REACHABLE->STALE
803 * 0 1 n -- (2c) *->REACHABLE
804 * 0 1 y n (2b) L *->REACHABLE
805 * 0 1 y y (1) REACHABLE->STALE
808 * 1 0 y y (2a) L *->STALE
809 * 1 1 n -- (2a) *->REACHABLE
810 * 1 1 y n (2a) L *->REACHABLE
811 * 1 1 y y (2a) L *->REACHABLE
813 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
815 * If state is REACHABLE, make it STALE.
816 * no other updates should be done.
818 if (ln->ln_state == ND6_LLINFO_REACHABLE) {
819 ln->ln_state = ND6_LLINFO_STALE;
820 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
823 } else if (is_override /* (2a) */
824 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
825 || lladdr == NULL) { /* (2c) */
827 * Update link-local address, if any.
829 if (lladdr != NULL) {
830 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
831 ln->la_flags |= LLE_VALID;
835 * If solicited, make the state REACHABLE.
836 * If not solicited and the link-layer address was
837 * changed, make it STALE.
840 ln->ln_state = ND6_LLINFO_REACHABLE;
842 if (!ND6_LLINFO_PERMANENT(ln)) {
843 nd6_llinfo_settimer_locked(ln,
844 (long)ND_IFINFO(ifp)->reachable * hz);
847 if (lladdr != NULL && llchange) {
848 ln->ln_state = ND6_LLINFO_STALE;
849 nd6_llinfo_settimer_locked(ln,
850 (long)V_nd6_gctimer * hz);
855 if (ln->ln_router && !is_router) {
857 * The peer dropped the router flag.
858 * Remove the sender from the Default Router List and
859 * update the Destination Cache entries.
861 struct nd_defrouter *dr;
862 struct in6_addr *in6;
864 in6 = &L3_ADDR_SIN6(ln)->sin6_addr;
867 * Lock to protect the default router list.
868 * XXX: this might be unnecessary, since this function
869 * is only called under the network software interrupt
870 * context. However, we keep it just for safety.
872 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp);
875 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags &
876 ND6_IFF_ACCEPT_RTADV) {
878 * Even if the neighbor is not in the default
879 * router list, the neighbor may be used
880 * as a next hop for some destinations
881 * (e.g. redirect case). So we must
882 * call rt6_flush explicitly.
884 rt6_flush(&ip6->ip6_src, ifp);
887 ln->ln_router = is_router;
891 * rt->rt_flags &= ~RTF_REJECT;
895 struct mbuf *m_hold, *m_hold_next;
898 * reset the la_hold in advance, to explicitly
899 * prevent a la_hold lookup in nd6_output()
900 * (wouldn't happen, though...)
902 for (m_hold = ln->la_hold, ln->la_hold = NULL;
903 m_hold; m_hold = m_hold_next) {
904 m_hold_next = m_hold->m_nextpkt;
905 m_hold->m_nextpkt = NULL;
907 * we assume ifp is not a loopback here, so just set
908 * the 2nd argument as the 1st one.
911 if (send_sendso_input_hook != NULL) {
912 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
913 sizeof(unsigned short), M_NOWAIT);
916 m_tag_prepend(m, mtag);
919 nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
925 memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
929 nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
932 pfxlist_onlink_check();
941 ICMP6STAT_INC(icp6s_badna);
946 * Neighbor advertisement output handling.
950 * the following items are not implemented yet:
951 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
952 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
954 * tlladdr - 1 if include target link-layer address
955 * sdl0 - sockaddr_dl (= proxy NA) or NULL
958 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
959 const struct in6_addr *taddr6, u_long flags, int tlladdr,
960 struct sockaddr *sdl0)
965 struct nd_neighbor_advert *nd_na;
966 struct ip6_moptions im6o;
967 struct in6_addr src, daddr6;
968 struct sockaddr_in6 dst_sa;
969 int icmp6len, maxlen, error;
973 bzero(&ro, sizeof(ro));
975 daddr6 = *daddr6_0; /* make a local copy for modification */
977 /* estimate the size of message */
978 maxlen = sizeof(*ip6) + sizeof(*nd_na);
979 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
980 if (max_linkhdr + maxlen >= MCLBYTES) {
982 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
983 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
988 MGETHDR(m, M_DONTWAIT, MT_DATA);
989 if (m && max_linkhdr + maxlen >= MHLEN) {
990 MCLGET(m, M_DONTWAIT);
991 if ((m->m_flags & M_EXT) == 0) {
998 m->m_pkthdr.rcvif = NULL;
1000 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
1001 m->m_flags |= M_MCAST;
1002 im6o.im6o_multicast_ifp = ifp;
1003 im6o.im6o_multicast_hlim = 255;
1004 im6o.im6o_multicast_loop = 0;
1007 icmp6len = sizeof(*nd_na);
1008 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
1009 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
1011 /* fill neighbor advertisement packet */
1012 ip6 = mtod(m, struct ip6_hdr *);
1014 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1015 ip6->ip6_vfc |= IPV6_VERSION;
1016 ip6->ip6_nxt = IPPROTO_ICMPV6;
1017 ip6->ip6_hlim = 255;
1018 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
1020 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
1021 daddr6.s6_addr16[1] = 0;
1022 daddr6.s6_addr32[1] = 0;
1023 daddr6.s6_addr32[2] = 0;
1024 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
1025 if (in6_setscope(&daddr6, ifp, NULL))
1028 flags &= ~ND_NA_FLAG_SOLICITED;
1030 ip6->ip6_dst = daddr6;
1031 bzero(&dst_sa, sizeof(struct sockaddr_in6));
1032 dst_sa.sin6_family = AF_INET6;
1033 dst_sa.sin6_len = sizeof(struct sockaddr_in6);
1034 dst_sa.sin6_addr = daddr6;
1037 * Select a source whose scope is the same as that of the dest.
1039 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
1040 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, NULL, &src);
1042 char ip6buf[INET6_ADDRSTRLEN];
1043 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1044 "determined: dst=%s, error=%d\n",
1045 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error));
1049 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1050 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1051 nd_na->nd_na_code = 0;
1052 nd_na->nd_na_target = *taddr6;
1053 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1056 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1057 * see nd6_ns_input() for details.
1058 * Basically, if NS packet is sent to unicast/anycast addr,
1059 * target lladdr option SHOULD NOT be included.
1063 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1064 * lladdr in sdl0. If we are not proxying (sending NA for
1065 * my address) use lladdr configured for the interface.
1069 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1071 mac = nd6_ifptomac(ifp);
1072 } else if (sdl0->sa_family == AF_LINK) {
1073 struct sockaddr_dl *sdl;
1074 sdl = (struct sockaddr_dl *)sdl0;
1075 if (sdl->sdl_alen == ifp->if_addrlen)
1079 if (tlladdr && mac) {
1080 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1081 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1083 /* roundup to 8 bytes alignment! */
1084 optlen = (optlen + 7) & ~7;
1086 m->m_pkthdr.len += optlen;
1089 bzero((caddr_t)nd_opt, optlen);
1090 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1091 nd_opt->nd_opt_len = optlen >> 3;
1092 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1094 flags &= ~ND_NA_FLAG_OVERRIDE;
1096 ip6->ip6_plen = htons((u_short)icmp6len);
1097 nd_na->nd_na_flags_reserved = flags;
1098 nd_na->nd_na_cksum = 0;
1099 nd_na->nd_na_cksum =
1100 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1102 if (send_sendso_input_hook != NULL) {
1103 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1104 sizeof(unsigned short), M_NOWAIT);
1107 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1108 m_tag_prepend(m, mtag);
1111 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL);
1112 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1113 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1114 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1116 if (ro.ro_rt) { /* we don't cache this route. */
1130 nd6_ifptomac(struct ifnet *ifp)
1132 switch (ifp->if_type) {
1140 #ifdef IFT_IEEE80211
1143 case IFT_INFINIBAND:
1146 return IF_LLADDR(ifp);
1153 TAILQ_ENTRY(dadq) dad_list;
1154 struct ifaddr *dad_ifa;
1155 int dad_count; /* max NS to send */
1156 int dad_ns_tcount; /* # of trials to send NS */
1157 int dad_ns_ocount; /* NS sent so far */
1160 struct callout dad_timer_ch;
1161 struct vnet *dad_vnet;
1164 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
1165 VNET_DEFINE(int, dad_init) = 0;
1166 #define V_dadq VNET(dadq)
1167 #define V_dad_init VNET(dad_init)
1169 static struct dadq *
1170 nd6_dad_find(struct ifaddr *ifa)
1174 TAILQ_FOREACH(dp, &V_dadq, dad_list)
1175 if (dp->dad_ifa == ifa)
1182 nd6_dad_starttimer(struct dadq *dp, int ticks)
1185 callout_reset(&dp->dad_timer_ch, ticks,
1186 (void (*)(void *))nd6_dad_timer, (void *)dp);
1190 nd6_dad_stoptimer(struct dadq *dp)
1193 callout_stop(&dp->dad_timer_ch);
1197 * Start Duplicate Address Detection (DAD) for specified interface address.
1200 nd6_dad_start(struct ifaddr *ifa, int delay)
1202 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1204 char ip6buf[INET6_ADDRSTRLEN];
1207 TAILQ_INIT(&V_dadq);
1212 * If we don't need DAD, don't do it.
1213 * There are several cases:
1214 * - DAD is disabled (ip6_dad_count == 0)
1215 * - the interface address is anycast
1217 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1219 "nd6_dad_start: called with non-tentative address "
1221 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1222 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1225 if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1226 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1229 if (!V_ip6_dad_count) {
1230 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1233 if (ifa->ifa_ifp == NULL)
1234 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1235 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
1238 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)
1240 if (nd6_dad_find(ifa) != NULL) {
1241 /* DAD already in progress */
1245 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
1247 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1249 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1250 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1253 bzero(dp, sizeof(*dp));
1254 callout_init(&dp->dad_timer_ch, 0);
1256 dp->dad_vnet = curvnet;
1258 TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list);
1260 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1261 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1264 * Send NS packet for DAD, ip6_dad_count times.
1265 * Note that we must delay the first transmission, if this is the
1266 * first packet to be sent from the interface after interface
1267 * (re)initialization.
1270 ifa_ref(ifa); /* just for safety */
1271 dp->dad_count = V_ip6_dad_count;
1272 dp->dad_ns_icount = dp->dad_na_icount = 0;
1273 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1275 nd6_dad_ns_output(dp, ifa);
1276 nd6_dad_starttimer(dp,
1277 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1279 nd6_dad_starttimer(dp, delay);
1284 * terminate DAD unconditionally. used for address removals.
1287 nd6_dad_stop(struct ifaddr *ifa)
1293 dp = nd6_dad_find(ifa);
1295 /* DAD wasn't started yet */
1299 nd6_dad_stoptimer(dp);
1301 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1308 nd6_dad_timer(struct dadq *dp)
1310 CURVNET_SET(dp->dad_vnet);
1312 struct ifaddr *ifa = dp->dad_ifa;
1313 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1314 char ip6buf[INET6_ADDRSTRLEN];
1316 s = splnet(); /* XXX */
1320 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1323 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1324 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1326 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1327 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1330 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1331 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1333 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1334 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1338 /* timeouted with IFF_{RUNNING,UP} check */
1339 if (dp->dad_ns_tcount > V_dad_maxtry) {
1340 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
1341 if_name(ifa->ifa_ifp)));
1343 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1350 /* Need more checks? */
1351 if (dp->dad_ns_ocount < dp->dad_count) {
1353 * We have more NS to go. Send NS packet for DAD.
1355 nd6_dad_ns_output(dp, ifa);
1356 nd6_dad_starttimer(dp,
1357 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1360 * We have transmitted sufficient number of DAD packets.
1361 * See what we've got.
1367 if (dp->dad_na_icount) {
1369 * the check is in nd6_dad_na_input(),
1375 if (dp->dad_ns_icount) {
1376 /* We've seen NS, means DAD has failed. */
1381 /* (*dp) will be freed in nd6_dad_duplicated() */
1383 nd6_dad_duplicated(ifa);
1386 * We are done with DAD. No NA came, no NS came.
1387 * No duplicate address found.
1389 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1392 "%s: DAD complete for %s - no duplicates found\n",
1393 if_name(ifa->ifa_ifp),
1394 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1396 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1409 nd6_dad_duplicated(struct ifaddr *ifa)
1411 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1414 char ip6buf[INET6_ADDRSTRLEN];
1416 dp = nd6_dad_find(ifa);
1418 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
1422 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1423 "NS in/out=%d/%d, NA in=%d\n",
1424 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1425 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
1427 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1428 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1430 /* We are done with DAD, with duplicate address found. (failure) */
1431 nd6_dad_stoptimer(dp);
1434 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1435 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1436 log(LOG_ERR, "%s: manual intervention required\n",
1440 * If the address is a link-local address formed from an interface
1441 * identifier based on the hardware address which is supposed to be
1442 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1443 * operation on the interface SHOULD be disabled.
1444 * [RFC 4862, Section 5.4.5]
1446 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1447 struct in6_addr in6;
1450 * To avoid over-reaction, we only apply this logic when we are
1451 * very sure that hardware addresses are supposed to be unique.
1453 switch (ifp->if_type) {
1458 #ifdef IFT_IEEE80211
1461 case IFT_INFINIBAND:
1462 in6 = ia->ia_addr.sin6_addr;
1463 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1464 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1465 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1466 log(LOG_ERR, "%s: possible hardware address "
1467 "duplication detected, disable IPv6\n",
1474 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1481 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
1483 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1484 struct ifnet *ifp = ifa->ifa_ifp;
1486 dp->dad_ns_tcount++;
1487 if ((ifp->if_flags & IFF_UP) == 0) {
1490 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1494 dp->dad_ns_ocount++;
1495 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
1499 nd6_dad_ns_input(struct ifaddr *ifa)
1501 struct in6_ifaddr *ia;
1503 const struct in6_addr *taddr6;
1508 panic("ifa == NULL in nd6_dad_ns_input");
1510 ia = (struct in6_ifaddr *)ifa;
1512 taddr6 = &ia->ia_addr.sin6_addr;
1514 dp = nd6_dad_find(ifa);
1516 /* Quickhack - completely ignore DAD NS packets */
1517 if (V_dad_ignore_ns) {
1518 char ip6buf[INET6_ADDRSTRLEN];
1520 "nd6_dad_ns_input: ignoring DAD NS packet for "
1521 "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6),
1522 if_name(ifa->ifa_ifp)));
1527 * if I'm yet to start DAD, someone else started using this address
1528 * first. I have a duplicate and you win.
1530 if (dp == NULL || dp->dad_ns_ocount == 0)
1533 /* XXX more checks for loopback situation - see nd6_dad_timer too */
1536 dp = NULL; /* will be freed in nd6_dad_duplicated() */
1537 nd6_dad_duplicated(ifa);
1540 * not sure if I got a duplicate.
1541 * increment ns count and see what happens.
1544 dp->dad_ns_icount++;
1549 nd6_dad_na_input(struct ifaddr *ifa)
1554 panic("ifa == NULL in nd6_dad_na_input");
1556 dp = nd6_dad_find(ifa);
1558 dp->dad_na_icount++;
1560 /* remove the address. */
1561 nd6_dad_duplicated(ifa);