1 /* $FreeBSD: src/sys/netinet6/nd6_nbr.c,v 1.4.2.6 2003/01/23 21:06:47 sam Exp $ */
2 /* $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $ */
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #include "opt_inet6.h"
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
41 #include <sys/socket.h>
42 #include <sys/sockio.h>
44 #include <sys/kernel.h>
45 #include <sys/errno.h>
46 #include <sys/syslog.h>
47 #include <sys/queue.h>
48 #include <sys/callout.h>
49 #include <sys/mutex.h>
51 #include <sys/thread2.h>
52 #include <sys/mutex2.h>
55 #include <net/if_types.h>
56 #include <net/if_dl.h>
57 #include <net/route.h>
58 #include <net/netisr2.h>
59 #include <net/netmsg2.h>
61 #include <netinet/in.h>
62 #include <netinet/in_var.h>
63 #include <netinet6/in6_var.h>
64 #include <netinet/ip6.h>
65 #include <netinet6/ip6_var.h>
66 #include <netinet6/nd6.h>
67 #include <netinet/icmp6.h>
69 #include <net/net_osdep.h>
72 #include <netinet/ip_carp.h>
76 #define SDL(s) ((struct sockaddr_dl *)s)
79 static struct dadq
*nd6_dad_find(struct ifaddr
*);
80 static void nd6_dad_starttimer(struct dadq
*, int);
81 static void nd6_dad_stoptimer(struct dadq
*);
82 static void nd6_dad_timer(void *);
83 static void nd6_dad_timer_handler(netmsg_t
);
84 static void nd6_dad_ns_output(struct dadq
*);
85 static void nd6_dad_ns_input(struct ifaddr
*);
86 static void nd6_dad_na_input(struct ifaddr
*);
87 static struct dadq
*nd6_dad_create(struct ifaddr
*);
88 static void nd6_dad_destroy(struct dadq
*);
89 static void nd6_dad_duplicated(struct ifaddr
*);
91 static int dad_ignore_ns
= 0; /* ignore NS in DAD - specwise incorrect*/
92 static int dad_maxtry
= 15; /* max # of *tries* to transmit DAD packet */
95 * Input an Neighbor Solicitation Message.
98 * Based on RFC 2462 (duplicated address detection)
101 nd6_ns_input(struct mbuf
*m
, int off
, int icmp6len
)
103 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
104 struct ifnet
*cmpifp
;
105 struct ip6_hdr
*ip6
= mtod(m
, struct ip6_hdr
*);
106 struct nd_neighbor_solicit
*nd_ns
;
107 struct in6_addr saddr6
= ip6
->ip6_src
;
108 struct in6_addr daddr6
= ip6
->ip6_dst
;
109 struct in6_addr taddr6
;
110 struct in6_addr myaddr6
;
112 struct ifaddr
*ifa
= NULL
;
114 int anycast
= 0, proxy
= 0, tentative
= 0;
116 union nd_opts ndopts
;
117 struct sockaddr_dl
*proxydl
= NULL
;
120 * Collapse interfaces to the bridge for comparison and
121 * mac (llinfo) purposes.
125 cmpifp
= ifp
->if_bridge
;
127 #ifndef PULLDOWN_TEST
128 IP6_EXTHDR_CHECK(m
, off
, icmp6len
,);
129 nd_ns
= (struct nd_neighbor_solicit
*)((caddr_t
)ip6
+ off
);
131 IP6_EXTHDR_GET(nd_ns
, struct nd_neighbor_solicit
*, m
, off
, icmp6len
);
133 icmp6stat
.icp6s_tooshort
++;
137 ip6
= mtod(m
, struct ip6_hdr
*); /* adjust pointer for safety */
138 taddr6
= nd_ns
->nd_ns_target
;
140 if (ip6
->ip6_hlim
!= 255) {
142 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
143 ip6
->ip6_hlim
, ip6_sprintf(&ip6
->ip6_src
),
144 ip6_sprintf(&ip6
->ip6_dst
), if_name(ifp
)));
148 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6
)) {
149 /* dst has to be solicited node multicast address. */
150 if (daddr6
.s6_addr16
[0] == IPV6_ADDR_INT16_MLL
&&
151 /* don't check ifindex portion */
152 daddr6
.s6_addr32
[1] == 0 &&
153 daddr6
.s6_addr32
[2] == IPV6_ADDR_INT32_ONE
&&
154 daddr6
.s6_addr8
[12] == 0xff) {
157 nd6log((LOG_INFO
, "nd6_ns_input: bad DAD packet "
158 "(wrong ip6 dst)\n"));
161 } else if (!nd6_onlink_ns_rfc4861
) {
163 * Make sure the source address is from a neighbor's address.
165 * XXX probably only need to check cmpifp.
167 if (in6ifa_ifplocaladdr(cmpifp
, &saddr6
) == NULL
&&
168 in6ifa_ifplocaladdr(ifp
, &saddr6
) == NULL
) {
169 nd6log((LOG_INFO
, "nd6_ns_input: "
170 "NS packet from non-neighbor\n"));
175 if (IN6_IS_ADDR_MULTICAST(&taddr6
)) {
176 nd6log((LOG_INFO
, "nd6_ns_input: bad NS target (multicast)\n"));
180 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6
))
181 taddr6
.s6_addr16
[1] = htons(ifp
->if_index
);
183 icmp6len
-= sizeof(*nd_ns
);
184 nd6_option_init(nd_ns
+ 1, icmp6len
, &ndopts
);
185 if (nd6_options(&ndopts
) < 0) {
187 "nd6_ns_input: invalid ND option, ignored\n"));
188 /* nd6_options have incremented stats */
192 if (ndopts
.nd_opts_src_lladdr
) {
193 lladdr
= (char *)(ndopts
.nd_opts_src_lladdr
+ 1);
194 lladdrlen
= ndopts
.nd_opts_src_lladdr
->nd_opt_len
<< 3;
197 if (IN6_IS_ADDR_UNSPECIFIED(&ip6
->ip6_src
) && lladdr
) {
198 nd6log((LOG_INFO
, "nd6_ns_input: bad DAD packet "
199 "(link-layer address option)\n"));
204 * Attaching target link-layer address to the NA?
207 * NS IP dst is unicast/anycast MUST NOT add
208 * NS IP dst is solicited-node multicast MUST add
210 * In implementation, we add target link-layer address by default.
211 * We do not add one in MUST NOT cases.
213 #if 0 /* too much! */
214 ifa
= (struct ifaddr
*)in6ifa_ifpwithaddr(ifp
, &daddr6
);
215 if (ifa
&& (((struct in6_ifaddr
*)ifa
)->ia6_flags
& IN6_IFF_ANYCAST
))
219 if (!IN6_IS_ADDR_MULTICAST(&daddr6
))
225 * Target address (taddr6) must be either:
226 * (1) Valid unicast/anycast address for my receiving interface.
227 * (2) Unicast or anycast address for which I'm offering proxy
229 * (3) "tentative" address on which DAD is being performed.
231 /* (1) and (3) check. */
234 ifa
= carp_iamatch6(ifp
->if_carp
, &taddr6
);
236 ifa
= (struct ifaddr
*)in6ifa_ifpwithaddr(ifp
, &taddr6
);
238 ifa
= (struct ifaddr
*)in6ifa_ifpwithaddr(ifp
, &taddr6
);
242 * (2) Check proxying. Requires ip6_forwarding to be turned on.
244 * If the packet is anycast the target route must be on a
245 * different interface because the anycast will get anything
246 * on the current interface.
248 * If the packet is unicast the target route may be on the
249 * same interface. If the gateway is a (typically manually
250 * configured) link address we can directly offer it.
251 * XXX for now we don't do this but instead offer ours and
254 * WARNING! Since this is a subnet proxy the interface proxying
255 * the ND6 must be in promiscuous mode or it will not see the
256 * solicited multicast requests for various hosts being proxied.
258 * WARNING! Since this is a subnet proxy we have to treat bridge
259 * interfaces as being the bridge itself so we do not proxy-nd6
260 * between bridge interfaces (which are effectively switched).
262 * (In the specific-host-proxy case via RTF_ANNOUNCE, which is
263 * a bitch to configure, a specific multicast route is already
264 * added for that host <-- NOT RECOMMENDED).
266 if (!ifa
&& ip6_forwarding
) {
268 struct sockaddr_in6 tsin6
;
271 bzero(&tsin6
, sizeof tsin6
);
272 tsin6
.sin6_len
= sizeof(struct sockaddr_in6
);
273 tsin6
.sin6_family
= AF_INET6
;
274 tsin6
.sin6_addr
= taddr6
;
276 rt
= rtpurelookup((struct sockaddr
*)&tsin6
);
277 rtifp
= rt
? rt
->rt_ifp
: NULL
;
278 if (rtifp
&& rtifp
->if_bridge
)
279 rtifp
= rtifp
->if_bridge
;
282 (cmpifp
!= rtifp
|| (m
->m_flags
& M_MCAST
) == 0)) {
283 ifa
= (struct ifaddr
*)in6ifa_ifpforlinklocal(cmpifp
,
284 IN6_IFF_NOTREADY
|IN6_IFF_ANYCAST
);
286 "nd6_ns_input: nd6 proxy %s(%s)<-%s ifa %p\n",
287 if_name(cmpifp
), if_name(ifp
),
288 if_name(rtifp
), ifa
));
292 * Manual link address on same interface
293 * w/announce flag will proxy-arp using
294 * target mac, else our mac is used.
296 if (cmpifp
== rtifp
&&
297 (rt
->rt_flags
& RTF_ANNOUNCE
) &&
298 rt
->rt_gateway
->sa_family
== AF_LINK
) {
299 proxydl
= SDL(rt
->rt_gateway
);
308 * We've got an NS packet, and we don't have that adddress
309 * assigned for us. We MUST silently ignore it.
314 myaddr6
= *IFA_IN6(ifa
);
315 anycast
= ((struct in6_ifaddr
*)ifa
)->ia6_flags
& IN6_IFF_ANYCAST
;
316 tentative
= ((struct in6_ifaddr
*)ifa
)->ia6_flags
& IN6_IFF_TENTATIVE
;
317 if (((struct in6_ifaddr
*)ifa
)->ia6_flags
& IN6_IFF_DUPLICATED
)
320 if (lladdr
&& ((cmpifp
->if_addrlen
+ 2 + 7) & ~7) != lladdrlen
) {
321 nd6log((LOG_INFO
, "nd6_ns_input: lladdrlen mismatch for %s "
322 "(if %d, NS packet %d)\n",
323 ip6_sprintf(&taddr6
), cmpifp
->if_addrlen
, lladdrlen
- 2));
327 if (IN6_ARE_ADDR_EQUAL(&myaddr6
, &saddr6
)) {
328 nd6log((LOG_INFO
, "nd6_ns_input: duplicate IP6 address %s\n",
329 ip6_sprintf(&saddr6
)));
334 * We have neighbor solicitation packet, with target address equals to
335 * one of my tentative address.
337 * src addr how to process?
339 * multicast of course, invalid (rejected in ip6_input)
340 * unicast somebody is doing address resolution -> ignore
341 * unspec dup address detection
343 * The processing is defined in RFC 2462.
347 * If source address is unspecified address, it is for
348 * duplicated address detection.
350 * If not, the packet is for addess resolution;
351 * silently ignore it.
353 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6
))
354 nd6_dad_ns_input(ifa
);
360 * If the source address is unspecified address, entries must not
361 * be created or updated.
362 * It looks that sender is performing DAD. Output NA toward
363 * all-node multicast address, to tell the sender that I'm using
365 * S bit ("solicited") must be zero.
367 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6
)) {
368 saddr6
= kin6addr_linklocal_allnodes
;
369 saddr6
.s6_addr16
[1] = htons(cmpifp
->if_index
);
370 nd6_na_output(cmpifp
, &saddr6
, &taddr6
,
371 ((anycast
|| proxy
|| !tlladdr
) ? 0 : ND_NA_FLAG_OVERRIDE
) |
372 (ip6_forwarding
? ND_NA_FLAG_ROUTER
: 0),
373 tlladdr
, (struct sockaddr
*)proxydl
);
377 nd6_cache_lladdr(cmpifp
, &saddr6
, lladdr
, lladdrlen
,
378 ND_NEIGHBOR_SOLICIT
, 0);
380 nd6_na_output(ifp
, &saddr6
, &taddr6
,
381 ((anycast
|| proxy
|| !tlladdr
) ? 0 : ND_NA_FLAG_OVERRIDE
) |
382 (ip6_forwarding
? ND_NA_FLAG_ROUTER
: 0) | ND_NA_FLAG_SOLICITED
,
383 tlladdr
, (struct sockaddr
*)proxydl
);
389 nd6log((LOG_ERR
, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6
)));
390 nd6log((LOG_ERR
, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6
)));
391 nd6log((LOG_ERR
, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6
)));
392 icmp6stat
.icp6s_badns
++;
397 * Output an Neighbor Solicitation Message. Caller specifies:
398 * - ICMP6 header source IP6 address
399 * - ND6 header target IP6 address
400 * - ND6 header source datalink address
403 * Based on RFC 2462 (duplicated address detection)
406 nd6_ns_output(struct ifnet
*ifp
, const struct in6_addr
*daddr6
,
407 const struct in6_addr
*taddr6
,
408 struct llinfo_nd6
*ln
, /* for source address determination */
409 int dad
) /* duplicated address detection */
413 struct nd_neighbor_solicit
*nd_ns
;
414 struct in6_ifaddr
*ia
= NULL
;
415 struct ip6_moptions im6o
;
419 struct ifnet
*outif
= NULL
;
421 if (IN6_IS_ADDR_MULTICAST(taddr6
))
424 /* estimate the size of message */
425 maxlen
= sizeof(*ip6
) + sizeof(*nd_ns
);
426 maxlen
+= (sizeof(struct nd_opt_hdr
) + ifp
->if_addrlen
+ 7) & ~7;
427 if (max_linkhdr
+ maxlen
> MCLBYTES
) {
429 kprintf("nd6_ns_output: max_linkhdr + maxlen > MCLBYTES "
430 "(%d + %d > %d)\n", max_linkhdr
, maxlen
, MCLBYTES
);
435 m
= m_getb(max_linkhdr
+ maxlen
, M_NOWAIT
, MT_DATA
, M_PKTHDR
);
439 if (daddr6
== NULL
|| IN6_IS_ADDR_MULTICAST(daddr6
)) {
440 m
->m_flags
|= M_MCAST
;
441 im6o
.im6o_multicast_ifp
= ifp
;
442 im6o
.im6o_multicast_hlim
= 255;
443 im6o
.im6o_multicast_loop
= 0;
446 icmp6len
= sizeof(*nd_ns
);
447 m
->m_pkthdr
.len
= m
->m_len
= sizeof(*ip6
) + icmp6len
;
448 m
->m_data
+= max_linkhdr
; /* or MH_ALIGN() equivalent? */
450 /* fill neighbor solicitation packet */
451 ip6
= mtod(m
, struct ip6_hdr
*);
453 ip6
->ip6_vfc
&= ~IPV6_VERSION_MASK
;
454 ip6
->ip6_vfc
|= IPV6_VERSION
;
455 /* ip6->ip6_plen will be set later */
456 ip6
->ip6_nxt
= IPPROTO_ICMPV6
;
459 ip6
->ip6_dst
= *daddr6
;
461 ip6
->ip6_dst
.s6_addr16
[0] = IPV6_ADDR_INT16_MLL
;
462 ip6
->ip6_dst
.s6_addr16
[1] = htons(ifp
->if_index
);
463 ip6
->ip6_dst
.s6_addr32
[1] = 0;
464 ip6
->ip6_dst
.s6_addr32
[2] = IPV6_ADDR_INT32_ONE
;
465 ip6
->ip6_dst
.s6_addr32
[3] = taddr6
->s6_addr32
[3];
466 ip6
->ip6_dst
.s6_addr8
[12] = 0xff;
471 * "If the source address of the packet prompting the
472 * solicitation is the same as one of the addresses assigned
473 * to the outgoing interface, that address SHOULD be placed
474 * in the IP Source Address of the outgoing solicitation.
475 * Otherwise, any one of the addresses assigned to the
476 * interface should be used."
478 * We use the source address for the prompting packet
480 * - saddr6 is given from the caller (by giving "ln"), and
481 * - saddr6 belongs to the outgoing interface.
482 * Otherwise, we perform a scope-wise match.
484 struct ip6_hdr
*hip6
; /* hold ip6 */
485 struct in6_addr
*saddr6
;
487 if (ln
&& ln
->ln_hold
) {
488 hip6
= mtod(ln
->ln_hold
, struct ip6_hdr
*);
490 if (sizeof(*hip6
) < ln
->ln_hold
->m_len
)
491 saddr6
= &hip6
->ip6_src
;
496 if (saddr6
&& in6ifa_ifpwithaddr(ifp
, saddr6
))
497 bcopy(saddr6
, &ip6
->ip6_src
, sizeof(*saddr6
));
499 ia
= in6_ifawithifp(ifp
, &ip6
->ip6_dst
);
504 ip6
->ip6_src
= ia
->ia_addr
.sin6_addr
;
508 * Source address for DAD packet must always be IPv6
509 * unspecified address. (0::0)
511 bzero(&ip6
->ip6_src
, sizeof(ip6
->ip6_src
));
513 nd_ns
= (struct nd_neighbor_solicit
*)(ip6
+ 1);
514 nd_ns
->nd_ns_type
= ND_NEIGHBOR_SOLICIT
;
515 nd_ns
->nd_ns_code
= 0;
516 nd_ns
->nd_ns_reserved
= 0;
517 nd_ns
->nd_ns_target
= *taddr6
;
518 in6_clearscope(&nd_ns
->nd_ns_target
); /* XXX */
521 * Add source link-layer address option.
523 * spec implementation
525 * DAD packet MUST NOT do not add the option
526 * there's no link layer address:
527 * impossible do not add the option
528 * there's link layer address:
529 * Multicast NS MUST add one add the option
530 * Unicast NS SHOULD add one add the option
532 if (!dad
&& (mac
= nd6_ifptomac(ifp
))) {
533 int optlen
= sizeof(struct nd_opt_hdr
) + ifp
->if_addrlen
;
534 struct nd_opt_hdr
*nd_opt
= (struct nd_opt_hdr
*)(nd_ns
+ 1);
535 /* 8 byte alignments... */
536 optlen
= (optlen
+ 7) & ~7;
538 m
->m_pkthdr
.len
+= optlen
;
541 bzero((caddr_t
)nd_opt
, optlen
);
542 nd_opt
->nd_opt_type
= ND_OPT_SOURCE_LINKADDR
;
543 nd_opt
->nd_opt_len
= optlen
>> 3;
544 bcopy(mac
, (caddr_t
)(nd_opt
+ 1), ifp
->if_addrlen
);
547 ip6
->ip6_plen
= htons((u_short
)icmp6len
);
548 nd_ns
->nd_ns_cksum
= 0;
550 in6_cksum(m
, IPPROTO_ICMPV6
, sizeof(*ip6
), icmp6len
);
552 ip6_output(m
, NULL
, NULL
, dad
? IPV6_DADOUTPUT
: 0, &im6o
, &outif
, NULL
);
554 icmp6_ifstat_inc(outif
, ifs6_out_msg
);
555 icmp6_ifstat_inc(outif
, ifs6_out_neighborsolicit
);
557 icmp6stat
.icp6s_outhist
[ND_NEIGHBOR_SOLICIT
]++;
561 * Neighbor advertisement input handling.
564 * Based on RFC 2462 (duplicated address detection)
566 * the following items are not implemented yet:
567 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
568 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
571 nd6_na_input(struct mbuf
*m
, int off
, int icmp6len
)
573 struct ifnet
*ifp
= m
->m_pkthdr
.rcvif
;
574 struct ip6_hdr
*ip6
= mtod(m
, struct ip6_hdr
*);
575 struct nd_neighbor_advert
*nd_na
;
576 struct in6_addr saddr6
= ip6
->ip6_src
;
577 struct in6_addr daddr6
= ip6
->ip6_dst
;
578 struct in6_addr taddr6
;
586 struct llinfo_nd6
*ln
;
588 struct sockaddr_dl
*sdl
;
589 union nd_opts ndopts
;
591 if (ip6
->ip6_hlim
!= 255) {
593 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
594 ip6
->ip6_hlim
, ip6_sprintf(&ip6
->ip6_src
),
595 ip6_sprintf(&ip6
->ip6_dst
), if_name(ifp
)));
599 #ifndef PULLDOWN_TEST
600 IP6_EXTHDR_CHECK(m
, off
, icmp6len
,);
601 nd_na
= (struct nd_neighbor_advert
*)((caddr_t
)ip6
+ off
);
603 IP6_EXTHDR_GET(nd_na
, struct nd_neighbor_advert
*, m
, off
, icmp6len
);
605 icmp6stat
.icp6s_tooshort
++;
609 taddr6
= nd_na
->nd_na_target
;
610 flags
= nd_na
->nd_na_flags_reserved
;
611 is_router
= ((flags
& ND_NA_FLAG_ROUTER
) != 0);
612 is_solicited
= ((flags
& ND_NA_FLAG_SOLICITED
) != 0);
613 is_override
= ((flags
& ND_NA_FLAG_OVERRIDE
) != 0);
615 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6
))
616 taddr6
.s6_addr16
[1] = htons(ifp
->if_index
);
618 if (IN6_IS_ADDR_MULTICAST(&taddr6
)) {
620 "nd6_na_input: invalid target address %s\n",
621 ip6_sprintf(&taddr6
)));
624 if (IN6_IS_ADDR_MULTICAST(&daddr6
))
627 "nd6_na_input: a solicited adv is multicasted\n"));
631 icmp6len
-= sizeof(*nd_na
);
632 nd6_option_init(nd_na
+ 1, icmp6len
, &ndopts
);
633 if (nd6_options(&ndopts
) < 0) {
635 "nd6_na_input: invalid ND option, ignored\n"));
636 /* nd6_options have incremented stats */
640 if (ndopts
.nd_opts_tgt_lladdr
) {
641 lladdr
= (char *)(ndopts
.nd_opts_tgt_lladdr
+ 1);
642 lladdrlen
= ndopts
.nd_opts_tgt_lladdr
->nd_opt_len
<< 3;
645 ifa
= (struct ifaddr
*)in6ifa_ifpwithaddr(ifp
, &taddr6
);
648 * Target address matches one of my interface address.
650 * If my address is tentative, this means that there's somebody
651 * already using the same address as mine. This indicates DAD failure.
652 * This is defined in RFC 2462.
654 * Otherwise, process as defined in RFC 2461.
657 && (((struct in6_ifaddr
*)ifa
)->ia6_flags
& IN6_IFF_TENTATIVE
)) {
658 nd6_dad_na_input(ifa
);
662 /* Just for safety, maybe unnecessary. */
665 "nd6_na_input: duplicate IP6 address %s\n",
666 ip6_sprintf(&taddr6
));
670 if (!nd6_onlink_ns_rfc4861
) {
672 * Make sure the source address is from a neighbor's address.
674 if (in6ifa_ifplocaladdr(ifp
, &saddr6
) == NULL
) {
675 nd6log((LOG_INFO
, "nd6_na_input: "
676 "NA packet from non-neighbor\n"));
681 if (lladdr
&& ((ifp
->if_addrlen
+ 2 + 7) & ~7) != lladdrlen
) {
682 nd6log((LOG_INFO
, "nd6_na_input: lladdrlen mismatch for %s "
683 "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6
),
684 ifp
->if_addrlen
, lladdrlen
- 2));
689 * If no neighbor cache entry is found, NA SHOULD silently be discarded.
691 rt
= nd6_lookup(&taddr6
, 0, ifp
);
693 ((ln
= (struct llinfo_nd6
*)rt
->rt_llinfo
) == NULL
) ||
694 ((sdl
= SDL(rt
->rt_gateway
)) == NULL
))
697 if (ln
->ln_state
== ND6_LLINFO_INCOMPLETE
) {
699 * If the link-layer has address, and no lladdr option came,
700 * discard the packet.
702 if (ifp
->if_addrlen
&& !lladdr
)
706 * Record link-layer address, and update the state.
708 sdl
->sdl_alen
= ifp
->if_addrlen
;
709 bcopy(lladdr
, LLADDR(sdl
), ifp
->if_addrlen
);
711 ln
->ln_state
= ND6_LLINFO_REACHABLE
;
714 ln
->ln_expire
= time_uptime
+
715 ND_IFINFO(rt
->rt_ifp
)->reachable
;
718 ln
->ln_state
= ND6_LLINFO_STALE
;
719 ln
->ln_expire
= time_uptime
+ nd6_gctimer
;
721 if ((ln
->ln_router
= is_router
) != 0) {
723 * This means a router's state has changed from
724 * non-reachable to probably reachable, and might
725 * affect the status of associated prefixes..
727 pfxlist_onlink_check();
733 * Check if the link-layer address has changed or not.
739 if (bcmp(lladdr
, LLADDR(sdl
), ifp
->if_addrlen
))
748 * This is VERY complex. Look at it with care.
750 * override solicit lladdr llchange action
755 * 0 0 y y (1) REACHABLE->STALE
756 * 0 1 n -- (2c) *->REACHABLE
757 * 0 1 y n (2b) L *->REACHABLE
758 * 0 1 y y (1) REACHABLE->STALE
761 * 1 0 y y (2a) L *->STALE
762 * 1 1 n -- (2a) *->REACHABLE
763 * 1 1 y n (2a) L *->REACHABLE
764 * 1 1 y y (2a) L *->REACHABLE
766 if (!is_override
&& (lladdr
&& llchange
)) { /* (1) */
768 * If state is REACHABLE, make it STALE.
769 * no other updates should be done.
771 if (ln
->ln_state
== ND6_LLINFO_REACHABLE
) {
772 ln
->ln_state
= ND6_LLINFO_STALE
;
773 ln
->ln_expire
= time_uptime
+ nd6_gctimer
;
776 } else if (is_override
/* (2a) */
777 || (lladdr
&& !llchange
) /* (2b) */
778 || !lladdr
) { /* (2c) */
780 * Update link-local address, if any.
783 sdl
->sdl_alen
= ifp
->if_addrlen
;
784 bcopy(lladdr
, LLADDR(sdl
), ifp
->if_addrlen
);
788 * If solicited, make the state REACHABLE.
789 * If not solicited and the link-layer address was
790 * changed, make it STALE.
793 ln
->ln_state
= ND6_LLINFO_REACHABLE
;
796 ln
->ln_expire
= time_uptime
+
797 ND_IFINFO(ifp
)->reachable
;
800 if (lladdr
&& llchange
) {
801 ln
->ln_state
= ND6_LLINFO_STALE
;
802 ln
->ln_expire
= time_uptime
+ nd6_gctimer
;
807 if (ln
->ln_router
&& !is_router
) {
809 * The peer dropped the router flag.
810 * Remove the sender from the Default Router List and
811 * update the Destination Cache entries.
813 struct nd_defrouter
*dr
;
814 struct in6_addr
*in6
;
816 in6
= &((struct sockaddr_in6
*)rt_key(rt
))->sin6_addr
;
819 * Lock to protect the default router list.
820 * XXX: this might be unnecessary, since this function
821 * is only called under the network software interrupt
822 * context. However, we keep it just for safety.
825 dr
= defrouter_lookup(in6
, rt
->rt_ifp
);
828 mtx_unlock(&nd6_mtx
);
830 if (dr
== NULL
&& !ip6_forwarding
&& ip6_accept_rtadv
) {
832 * Even if the neighbor is not in the default
833 * router list, the neighbor may be used
834 * as a next hop for some destinations
835 * (e.g. redirect case). So we must
836 * call rt6_flush explicitly.
838 rt6_flush(&ip6
->ip6_src
, rt
->rt_ifp
);
841 ln
->ln_router
= is_router
;
843 rt
->rt_flags
&= ~RTF_REJECT
;
847 * we assume ifp is not a loopback here, so just set the 2nd
848 * argument as the 1st one.
850 nd6_output(ifp
, ifp
, ln
->ln_hold
,
851 (struct sockaddr_in6
*)rt_key(rt
), rt
);
860 icmp6stat
.icp6s_badna
++;
865 * Neighbor advertisement output handling.
869 * the following items are not implemented yet:
870 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
871 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
874 nd6_na_output(struct ifnet
*ifp
, const struct in6_addr
*daddr6
,
875 const struct in6_addr
*taddr6
, u_long flags
,
876 int tlladdr
, /* 1 if include target link-layer address */
877 struct sockaddr
*sdl0
) /* sockaddr_dl (= proxy NA) or NULL */
881 struct nd_neighbor_advert
*nd_na
;
882 struct in6_ifaddr
*ia
= NULL
;
883 struct ip6_moptions im6o
;
887 struct ifnet
*outif
= NULL
;
889 /* estimate the size of message */
890 maxlen
= sizeof(*ip6
) + sizeof(*nd_na
);
891 maxlen
+= (sizeof(struct nd_opt_hdr
) + ifp
->if_addrlen
+ 7) & ~7;
892 if (max_linkhdr
+ maxlen
> MCLBYTES
) {
894 kprintf("nd6_na_output: max_linkhdr + maxlen > MCLBYTES "
895 "(%d + %d > %d)\n", max_linkhdr
, maxlen
, MCLBYTES
);
900 m
= m_getb(max_linkhdr
+ maxlen
, M_NOWAIT
, MT_DATA
, M_PKTHDR
);
904 if (IN6_IS_ADDR_MULTICAST(daddr6
)) {
905 m
->m_flags
|= M_MCAST
;
906 im6o
.im6o_multicast_ifp
= ifp
;
907 im6o
.im6o_multicast_hlim
= 255;
908 im6o
.im6o_multicast_loop
= 0;
911 icmp6len
= sizeof(*nd_na
);
912 m
->m_pkthdr
.len
= m
->m_len
= sizeof(struct ip6_hdr
) + icmp6len
;
913 m
->m_data
+= max_linkhdr
; /* or MH_ALIGN() equivalent? */
915 /* fill neighbor advertisement packet */
916 ip6
= mtod(m
, struct ip6_hdr
*);
918 ip6
->ip6_vfc
&= ~IPV6_VERSION_MASK
;
919 ip6
->ip6_vfc
|= IPV6_VERSION
;
920 ip6
->ip6_nxt
= IPPROTO_ICMPV6
;
922 if (IN6_IS_ADDR_UNSPECIFIED(daddr6
)) {
924 ip6
->ip6_dst
.s6_addr16
[0] = IPV6_ADDR_INT16_MLL
;
925 ip6
->ip6_dst
.s6_addr16
[1] = htons(ifp
->if_index
);
926 ip6
->ip6_dst
.s6_addr32
[1] = 0;
927 ip6
->ip6_dst
.s6_addr32
[2] = 0;
928 ip6
->ip6_dst
.s6_addr32
[3] = IPV6_ADDR_INT32_ONE
;
929 flags
&= ~ND_NA_FLAG_SOLICITED
;
931 ip6
->ip6_dst
= *daddr6
;
934 * Select a source whose scope is the same as that of the dest.
936 ia
= in6_ifawithifp(ifp
, &ip6
->ip6_dst
);
941 ip6
->ip6_src
= ia
->ia_addr
.sin6_addr
;
942 nd_na
= (struct nd_neighbor_advert
*)(ip6
+ 1);
943 nd_na
->nd_na_type
= ND_NEIGHBOR_ADVERT
;
944 nd_na
->nd_na_code
= 0;
945 nd_na
->nd_na_target
= *taddr6
;
946 in6_clearscope(&nd_na
->nd_na_target
); /* XXX */
949 * "tlladdr" indicates NS's condition for adding tlladdr or not.
950 * see nd6_ns_input() for details.
951 * Basically, if NS packet is sent to unicast/anycast addr,
952 * target lladdr option SHOULD NOT be included.
957 * sdl0 != NULL indicates proxy NA. If we do proxy, use
958 * lladdr in sdl0. If we are not proxying (sending NA for
959 * my address) use lladdr configured for the interface.
964 mac
= carp_macmatch6(ifp
->if_carp
, m
, taddr6
);
966 mac
= nd6_ifptomac(ifp
);
968 mac
= nd6_ifptomac(ifp
);
970 } else if (sdl0
->sa_family
== AF_LINK
) {
971 struct sockaddr_dl
*sdl
;
972 sdl
= (struct sockaddr_dl
*)sdl0
;
973 if (sdl
->sdl_alen
== ifp
->if_addrlen
)
978 int optlen
= sizeof(struct nd_opt_hdr
) + ifp
->if_addrlen
;
979 struct nd_opt_hdr
*nd_opt
= (struct nd_opt_hdr
*)(nd_na
+ 1);
981 /* roundup to 8 bytes alignment! */
982 optlen
= (optlen
+ 7) & ~7;
984 m
->m_pkthdr
.len
+= optlen
;
987 bzero((caddr_t
)nd_opt
, optlen
);
988 nd_opt
->nd_opt_type
= ND_OPT_TARGET_LINKADDR
;
989 nd_opt
->nd_opt_len
= optlen
>> 3;
990 bcopy(mac
, (caddr_t
)(nd_opt
+ 1), ifp
->if_addrlen
);
992 flags
&= ~ND_NA_FLAG_OVERRIDE
;
994 ip6
->ip6_plen
= htons((u_short
)icmp6len
);
995 nd_na
->nd_na_flags_reserved
= flags
;
996 nd_na
->nd_na_cksum
= 0;
998 in6_cksum(m
, IPPROTO_ICMPV6
, sizeof(struct ip6_hdr
), icmp6len
);
1000 ip6_output(m
, NULL
, NULL
, 0, &im6o
, &outif
, NULL
);
1002 icmp6_ifstat_inc(outif
, ifs6_out_msg
);
1003 icmp6_ifstat_inc(outif
, ifs6_out_neighboradvert
);
1005 icmp6stat
.icp6s_outhist
[ND_NEIGHBOR_ADVERT
]++;
1009 nd6_ifptomac(struct ifnet
*ifp
)
1011 switch (ifp
->if_type
) {
1017 #ifdef IFT_IEEE80211
1023 return ((caddr_t
)(ifp
+ 1));
1030 struct netmsg_base base
;
1035 TAILQ_ENTRY(dadq
) dad_list
;
1036 struct ifaddr
*dad_ifa
;
1037 int dad_count
; /* max NS to send */
1038 int dad_ns_tcount
; /* # of trials to send NS */
1039 int dad_ns_ocount
; /* NS sent so far */
1042 struct callout dad_timer_ch
;
1043 struct netmsg_dad dad_nmsg
;
1045 TAILQ_HEAD(dadq_head
, dadq
);
1047 static struct dadq_head dadq
= TAILQ_HEAD_INITIALIZER(dadq
);
1049 static struct dadq
*
1050 nd6_dad_find(struct ifaddr
*ifa
)
1056 TAILQ_FOREACH(dp
, &dadq
, dad_list
) {
1057 if (dp
->dad_ifa
== ifa
)
1064 nd6_dad_starttimer(struct dadq
*dp
, int ticks
)
1067 callout_reset(&dp
->dad_timer_ch
, ticks
, nd6_dad_timer
, dp
);
1071 nd6_dad_stoptimer(struct dadq
*dp
)
1074 callout_stop(&dp
->dad_timer_ch
);
1078 * Start Duplicated Address Detection (DAD) for specified interface address.
1081 nd6_dad_start(struct ifaddr
*ifa
,
1082 int *tick
) /* minimum delay ticks for IFF_UP event */
1084 struct in6_ifaddr
*ia
= (struct in6_ifaddr
*)ifa
;
1090 * If we don't need DAD, don't do it.
1091 * There are several cases:
1092 * - DAD is disabled (ip6_dad_count == 0)
1093 * - the interface address is anycast
1095 if (!(ia
->ia6_flags
& IN6_IFF_TENTATIVE
)) {
1097 "nd6_dad_start: called with non-tentative address "
1099 ip6_sprintf(&ia
->ia_addr
.sin6_addr
),
1100 ifa
->ifa_ifp
? if_name(ifa
->ifa_ifp
) : "???");
1103 if (ia
->ia6_flags
& IN6_IFF_ANYCAST
) {
1104 ia
->ia6_flags
&= ~IN6_IFF_TENTATIVE
;
1107 if (!ip6_dad_count
) {
1108 ia
->ia6_flags
&= ~IN6_IFF_TENTATIVE
;
1112 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1113 if (!(ifa
->ifa_ifp
->if_flags
& IFF_UP
))
1115 if (nd6_dad_find(ifa
) != NULL
) {
1116 /* DAD already in progress */
1120 dp
= nd6_dad_create(ifa
);
1121 nd6log((LOG_DEBUG
, "%s: starting DAD for %s\n", if_name(ifa
->ifa_ifp
),
1122 ip6_sprintf(&ia
->ia_addr
.sin6_addr
)));
1125 * Send NS packet for DAD, dp->dad_count times.
1126 * Note that we must delay the first transmission, if this is the
1127 * first packet to be sent from the interface after interface
1128 * (re)initialization.
1131 nd6_dad_ns_output(dp
);
1132 nd6_dad_starttimer(dp
,
1133 ND_IFINFO(ifa
->ifa_ifp
)->retrans
* hz
/ 1000);
1138 ntick
= krandom() % (MAX_RTR_SOLICITATION_DELAY
* hz
);
1140 ntick
= *tick
+ krandom() % (hz
/ 2);
1142 nd6_dad_starttimer(dp
, ntick
);
1147 * Terminate DAD unconditionally. Used for address removals.
1150 nd6_dad_stop(struct ifaddr
*ifa
)
1156 dp
= nd6_dad_find(ifa
);
1158 /* DAD wasn't started yet */
1161 nd6_dad_destroy(dp
);
1164 static struct dadq
*
1165 nd6_dad_create(struct ifaddr
*ifa
)
1167 struct netmsg_dad
*dm
;
1172 dp
= kmalloc(sizeof(*dp
), M_IP6NDP
, M_INTWAIT
| M_ZERO
);
1173 callout_init_mp(&dp
->dad_timer_ch
);
1176 netmsg_init(&dm
->base
, NULL
, &netisr_adone_rport
,
1177 MSGF_DROPABLE
| MSGF_PRIORITY
, nd6_dad_timer_handler
);
1181 IFAREF(ifa
); /* just for safety */
1183 /* Send NS packet for DAD, ip6_dad_count times. */
1184 dp
->dad_count
= ip6_dad_count
;
1186 TAILQ_INSERT_TAIL(&dadq
, dp
, dad_list
);
1192 nd6_dad_destroy(struct dadq
*dp
)
1194 struct lwkt_msg
*lmsg
= &dp
->dad_nmsg
.base
.lmsg
;
1198 TAILQ_REMOVE(&dadq
, dp
, dad_list
);
1200 nd6_dad_stoptimer(dp
);
1203 if ((lmsg
->ms_flags
& MSGF_DONE
) == 0)
1207 IFAFREE(dp
->dad_ifa
);
1208 kfree(dp
, M_IP6NDP
);
1212 nd6_dad_timer(void *xdp
)
1214 struct dadq
*dp
= xdp
;
1215 struct lwkt_msg
*lmsg
= &dp
->dad_nmsg
.base
.lmsg
;
1217 KASSERT(mycpuid
== 0, ("dad timer not on cpu0"));
1220 if (lmsg
->ms_flags
& MSGF_DONE
)
1221 lwkt_sendmsg_oncpu(netisr_cpuport(0), lmsg
);
1226 nd6_dad_timer_handler(netmsg_t msg
)
1228 struct netmsg_dad
*dm
= (struct netmsg_dad
*)msg
;
1229 struct dadq
*dp
= dm
->dadq
;
1230 struct ifaddr
*ifa
= dp
->dad_ifa
;
1231 struct in6_ifaddr
*ia
= (struct in6_ifaddr
*)ifa
;
1237 lwkt_replymsg(&dm
->base
.lmsg
, 0);
1240 if (ia
->ia6_flags
& IN6_IFF_DUPLICATED
) {
1241 log(LOG_ERR
, "nd6_dad_timer: called with duplicated address "
1243 ip6_sprintf(&ia
->ia_addr
.sin6_addr
),
1244 ifa
->ifa_ifp
? if_name(ifa
->ifa_ifp
) : "???");
1247 if (!(ia
->ia6_flags
& IN6_IFF_TENTATIVE
)) {
1248 log(LOG_ERR
, "nd6_dad_timer: called with non-tentative address "
1250 ip6_sprintf(&ia
->ia_addr
.sin6_addr
),
1251 ifa
->ifa_ifp
? if_name(ifa
->ifa_ifp
) : "???");
1255 /* Timed out with IFF_{RUNNING,UP} check */
1256 if (dp
->dad_ns_tcount
> dad_maxtry
) {
1257 nd6log((LOG_INFO
, "%s: could not run DAD, driver problem?\n",
1258 if_name(ifa
->ifa_ifp
)));
1262 /* Need more checks? */
1263 if (dp
->dad_ns_ocount
< dp
->dad_count
) {
1265 * We have more NS to go. Send NS packet for DAD.
1267 nd6_dad_ns_output(dp
);
1268 nd6_dad_starttimer(dp
,
1269 ND_IFINFO(ifa
->ifa_ifp
)->retrans
* hz
/ 1000);
1272 * We have transmitted sufficient number of DAD packets.
1273 * See what we've got.
1279 if (dp
->dad_na_icount
) {
1281 * the check is in nd6_dad_na_input(),
1287 if (dp
->dad_ns_icount
) {
1288 #if 0 /* heuristics */
1291 * - we have sent many(?) DAD NS, and
1292 * - the number of NS we sent equals to the
1293 * number of NS we've got, and
1295 * we may have a faulty network card/driver which
1296 * loops back multicasts to myself.
1298 if (3 < dp
->dad_count
1299 && dp
->dad_ns_icount
== dp
->dad_count
1300 && dp
->dad_na_icount
== 0) {
1301 log(LOG_INFO
, "DAD questionable for %s(%s): "
1302 "network card loops back multicast?\n",
1303 ip6_sprintf(&ia
->ia_addr
.sin6_addr
),
1304 if_name(ifa
->ifa_ifp
));
1305 /* XXX consider it a duplicate or not? */
1308 /* We've seen NS, means DAD has failed. */
1312 /* We've seen NS, means DAD has failed. */
1318 /* dp will be freed in nd6_dad_duplicated() */
1320 nd6_dad_duplicated(ifa
);
1323 * We are done with DAD. No NA came, no NS came.
1324 * duplicated address found.
1326 ia
->ia6_flags
&= ~IN6_IFF_TENTATIVE
;
1328 "%s: DAD complete for %s - no duplicates found\n",
1329 if_name(ifa
->ifa_ifp
),
1330 ip6_sprintf(&ia
->ia_addr
.sin6_addr
)));
1336 nd6_dad_destroy(dp
);
1340 nd6_dad_duplicated(struct ifaddr
*ifa
)
1342 struct in6_ifaddr
*ia
= (struct in6_ifaddr
*)ifa
;
1347 dp
= nd6_dad_find(ifa
);
1349 log(LOG_ERR
, "nd6_dad_duplicated: DAD structure not found\n");
1354 * We are done with DAD, with duplicated address found. (failure)
1356 log(LOG_ERR
, "%s: DAD detected duplicate IPv6 address %s: "
1357 "NS in/out=%d/%d, NA in=%d\n",
1358 if_name(ifa
->ifa_ifp
), ip6_sprintf(&ia
->ia_addr
.sin6_addr
),
1359 dp
->dad_ns_icount
, dp
->dad_ns_ocount
, dp
->dad_na_icount
);
1361 ia
->ia6_flags
&= ~IN6_IFF_TENTATIVE
;
1362 ia
->ia6_flags
|= IN6_IFF_DUPLICATED
;
1364 log(LOG_ERR
, "%s: DAD complete for %s - duplicate found\n",
1365 if_name(ifa
->ifa_ifp
), ip6_sprintf(&ia
->ia_addr
.sin6_addr
));
1366 log(LOG_ERR
, "%s: manual intervention required\n",
1367 if_name(ifa
->ifa_ifp
));
1369 nd6_dad_destroy(dp
);
1373 nd6_dad_ns_output(struct dadq
*dp
)
1375 struct in6_ifaddr
*ia
= (struct in6_ifaddr
*)dp
->dad_ifa
;
1376 struct ifnet
*ifp
= dp
->dad_ifa
->ifa_ifp
;
1380 dp
->dad_ns_tcount
++;
1381 if (!(ifp
->if_flags
& IFF_UP
)) {
1383 kprintf("%s: interface down?\n", if_name(ifp
));
1387 if (!(ifp
->if_flags
& IFF_RUNNING
)) {
1389 kprintf("%s: interface not running?\n", if_name(ifp
));
1394 dp
->dad_ns_ocount
++;
1395 nd6_ns_output(ifp
, NULL
, &ia
->ia_addr
.sin6_addr
, NULL
, 1);
1399 nd6_dad_ns_input(struct ifaddr
*ifa
)
1401 struct in6_ifaddr
*ia
;
1402 const struct in6_addr
*taddr6
;
1409 panic("ifa == NULL in nd6_dad_ns_input");
1411 ia
= (struct in6_ifaddr
*)ifa
;
1412 taddr6
= &ia
->ia_addr
.sin6_addr
;
1414 dp
= nd6_dad_find(ifa
);
1416 /* Quickhack - completely ignore DAD NS packets */
1417 if (dad_ignore_ns
) {
1419 "nd6_dad_ns_input: ignoring DAD NS packet for "
1420 "address %s(%s)\n", ip6_sprintf(taddr6
),
1421 if_name(ifa
->ifa_ifp
)));
1426 * if I'm yet to start DAD, someone else started using this address
1427 * first. I have a duplicate and you win.
1429 if (!dp
|| dp
->dad_ns_ocount
== 0)
1432 /* XXX more checks for loopback situation - see nd6_dad_timer too */
1435 dp
= NULL
; /* will be freed in nd6_dad_duplicated() */
1436 nd6_dad_duplicated(ifa
);
1439 * not sure if I got a duplicate.
1440 * increment ns count and see what happens.
1443 dp
->dad_ns_icount
++;
1448 nd6_dad_na_input(struct ifaddr
*ifa
)
1455 panic("ifa == NULL in nd6_dad_na_input");
1457 dp
= nd6_dad_find(ifa
);
1459 dp
->dad_na_icount
++;
1461 /* remove the address. */
1462 nd6_dad_duplicated(ifa
);