nd6_nbr.c revision 125873
1/*	$FreeBSD: head/sys/netinet6/nd6_nbr.c 125873 2004-02-16 16:58:48Z ume $	*/
2/*	$KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $	*/
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
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.
19 *
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
30 * SUCH DAMAGE.
31 */
32
33#include "opt_inet.h"
34#include "opt_inet6.h"
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/malloc.h>
39#include <sys/mbuf.h>
40#include <sys/socket.h>
41#include <sys/sockio.h>
42#include <sys/time.h>
43#include <sys/kernel.h>
44#include <sys/errno.h>
45#include <sys/syslog.h>
46#include <sys/queue.h>
47#include <sys/callout.h>
48
49#include <net/if.h>
50#include <net/if_types.h>
51#include <net/if_dl.h>
52#include <net/route.h>
53
54#include <netinet/in.h>
55#include <netinet/in_var.h>
56#include <netinet6/in6_var.h>
57#include <netinet/ip6.h>
58#include <netinet6/ip6_var.h>
59#include <netinet6/nd6.h>
60#include <netinet/icmp6.h>
61
62#include <net/net_osdep.h>
63
64#define SDL(s) ((struct sockaddr_dl *)s)
65
66struct dadq;
67static struct dadq *nd6_dad_find __P((struct ifaddr *));
68static void nd6_dad_starttimer __P((struct dadq *, int));
69static void nd6_dad_stoptimer __P((struct dadq *));
70static void nd6_dad_timer __P((struct ifaddr *));
71static void nd6_dad_ns_output __P((struct dadq *, struct ifaddr *));
72static void nd6_dad_ns_input __P((struct ifaddr *));
73static void nd6_dad_na_input __P((struct ifaddr *));
74
75static int dad_ignore_ns = 0;	/* ignore NS in DAD - specwise incorrect*/
76static int dad_maxtry = 15;	/* max # of *tries* to transmit DAD packet */
77
78/*
79 * Input a Neighbor Solicitation Message.
80 *
81 * Based on RFC 2461
82 * Based on RFC 2462 (duplicated address detection)
83 */
84void
85nd6_ns_input(m, off, icmp6len)
86	struct mbuf *m;
87	int off, icmp6len;
88{
89	struct ifnet *ifp = m->m_pkthdr.rcvif;
90	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
91	struct nd_neighbor_solicit *nd_ns;
92	struct in6_addr saddr6 = ip6->ip6_src;
93	struct in6_addr daddr6 = ip6->ip6_dst;
94	struct in6_addr taddr6;
95	struct in6_addr myaddr6;
96	char *lladdr = NULL;
97	struct ifaddr *ifa;
98	int lladdrlen = 0;
99	int anycast = 0, proxy = 0, tentative = 0;
100	int tlladdr;
101	union nd_opts ndopts;
102	struct sockaddr_dl *proxydl = NULL;
103
104#ifndef PULLDOWN_TEST
105	IP6_EXTHDR_CHECK(m, off, icmp6len,);
106	nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
107#else
108	IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
109	if (nd_ns == NULL) {
110		icmp6stat.icp6s_tooshort++;
111		return;
112	}
113#endif
114	ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
115	taddr6 = nd_ns->nd_ns_target;
116
117	if (ip6->ip6_hlim != 255) {
118		nd6log((LOG_ERR,
119		    "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
120		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
121		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
122		goto bad;
123	}
124
125	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
126		/* dst has to be solicited node multicast address. */
127		if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
128		    /* don't check ifindex portion */
129		    daddr6.s6_addr32[1] == 0 &&
130		    daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
131		    daddr6.s6_addr8[12] == 0xff) {
132			; /* good */
133		} else {
134			nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
135			    "(wrong ip6 dst)\n"));
136			goto bad;
137		}
138	}
139
140	if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
141		nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
142		goto bad;
143	}
144
145	if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
146		taddr6.s6_addr16[1] = htons(ifp->if_index);
147
148	icmp6len -= sizeof(*nd_ns);
149	nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
150	if (nd6_options(&ndopts) < 0) {
151		nd6log((LOG_INFO,
152		    "nd6_ns_input: invalid ND option, ignored\n"));
153		/* nd6_options have incremented stats */
154		goto freeit;
155	}
156
157	if (ndopts.nd_opts_src_lladdr) {
158		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
159		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
160	}
161
162	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
163		nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
164		    "(link-layer address option)\n"));
165		goto bad;
166	}
167
168	/*
169	 * Attaching target link-layer address to the NA?
170	 * (RFC 2461 7.2.4)
171	 *
172	 * NS IP dst is unicast/anycast			MUST NOT add
173	 * NS IP dst is solicited-node multicast	MUST add
174	 *
175	 * In implementation, we add target link-layer address by default.
176	 * We do not add one in MUST NOT cases.
177	 */
178#if 0 /* too much! */
179	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6);
180	if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST))
181		tlladdr = 0;
182	else
183#endif
184	if (!IN6_IS_ADDR_MULTICAST(&daddr6))
185		tlladdr = 0;
186	else
187		tlladdr = 1;
188
189	/*
190	 * Target address (taddr6) must be either:
191	 * (1) Valid unicast/anycast address for my receiving interface,
192	 * (2) Unicast address for which I'm offering proxy service, or
193	 * (3) "tentative" address on which DAD is being performed.
194	 */
195	/* (1) and (3) check. */
196	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
197
198	/* (2) check. */
199	if (!ifa) {
200		struct rtentry *rt;
201		struct sockaddr_in6 tsin6;
202		int need_proxy;
203
204		bzero(&tsin6, sizeof tsin6);
205		tsin6.sin6_len = sizeof(struct sockaddr_in6);
206		tsin6.sin6_family = AF_INET6;
207		tsin6.sin6_addr = taddr6;
208
209		rt = rtalloc1((struct sockaddr *)&tsin6, 0, 0);
210		need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
211		    rt->rt_gateway->sa_family == AF_LINK);
212		if (rt)
213			rtfree(rt);
214		if (need_proxy) {
215			/*
216			 * proxy NDP for single entry
217			 */
218			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
219				IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
220			if (ifa) {
221				proxy = 1;
222				proxydl = SDL(rt->rt_gateway);
223			}
224		}
225	}
226	if (!ifa) {
227		/*
228		 * We've got an NS packet, and we don't have that adddress
229		 * assigned for us.  We MUST silently ignore it.
230		 * See RFC2461 7.2.3.
231		 */
232		goto freeit;
233	}
234	myaddr6 = *IFA_IN6(ifa);
235	anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
236	tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
237	if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
238		goto freeit;
239
240	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
241		nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
242		    "(if %d, NS packet %d)\n",
243		    ip6_sprintf(&taddr6),
244		    ifp->if_addrlen, lladdrlen - 2));
245		goto bad;
246	}
247
248	if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
249		nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
250		    ip6_sprintf(&saddr6)));
251		goto freeit;
252	}
253
254	/*
255	 * We have neighbor solicitation packet, with target address equals to
256	 * one of my tentative address.
257	 *
258	 * src addr	how to process?
259	 * ---		---
260	 * multicast	of course, invalid (rejected in ip6_input)
261	 * unicast	somebody is doing address resolution -> ignore
262	 * unspec	dup address detection
263	 *
264	 * The processing is defined in RFC 2462.
265	 */
266	if (tentative) {
267		/*
268		 * If source address is unspecified address, it is for
269		 * duplicated address detection.
270		 *
271		 * If not, the packet is for addess resolution;
272		 * silently ignore it.
273		 */
274		if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
275			nd6_dad_ns_input(ifa);
276
277		goto freeit;
278	}
279
280	/*
281	 * If the source address is unspecified address, entries must not
282	 * be created or updated.
283	 * It looks that sender is performing DAD.  Output NA toward
284	 * all-node multicast address, to tell the sender that I'm using
285	 * the address.
286	 * S bit ("solicited") must be zero.
287	 */
288	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
289		saddr6 = in6addr_linklocal_allnodes;
290		saddr6.s6_addr16[1] = htons(ifp->if_index);
291		nd6_na_output(ifp, &saddr6, &taddr6,
292		    ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
293		    (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0),
294		    tlladdr, (struct sockaddr *)proxydl);
295		goto freeit;
296	}
297
298	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
299	    ND_NEIGHBOR_SOLICIT, 0);
300
301	nd6_na_output(ifp, &saddr6, &taddr6,
302	    ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
303	    (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
304	    tlladdr, (struct sockaddr *)proxydl);
305 freeit:
306	m_freem(m);
307	return;
308
309 bad:
310	nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)));
311	nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)));
312	nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)));
313	icmp6stat.icp6s_badns++;
314	m_freem(m);
315}
316
317/*
318 * Output a Neighbor Solicitation Message. Caller specifies:
319 *	- ICMP6 header source IP6 address
320 *	- ND6 header target IP6 address
321 *	- ND6 header source datalink address
322 *
323 * Based on RFC 2461
324 * Based on RFC 2462 (duplicated address detection)
325 */
326void
327nd6_ns_output(ifp, daddr6, taddr6, ln, dad)
328	struct ifnet *ifp;
329	const struct in6_addr *daddr6, *taddr6;
330	struct llinfo_nd6 *ln;	/* for source address determination */
331	int dad;	/* duplicated address detection */
332{
333	struct mbuf *m;
334	struct ip6_hdr *ip6;
335	struct nd_neighbor_solicit *nd_ns;
336	struct in6_ifaddr *ia = NULL;
337	struct ip6_moptions im6o;
338	int icmp6len;
339	int maxlen;
340	caddr_t mac;
341	struct ifnet *outif = NULL;
342
343	if (IN6_IS_ADDR_MULTICAST(taddr6))
344		return;
345
346	/* estimate the size of message */
347	maxlen = sizeof(*ip6) + sizeof(*nd_ns);
348	maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
349	if (max_linkhdr + maxlen >= MCLBYTES) {
350#ifdef DIAGNOSTIC
351		printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
352		    "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
353#endif
354		return;
355	}
356
357	MGETHDR(m, M_DONTWAIT, MT_DATA);
358	if (m && max_linkhdr + maxlen >= MHLEN) {
359		MCLGET(m, M_DONTWAIT);
360		if ((m->m_flags & M_EXT) == 0) {
361			m_free(m);
362			m = NULL;
363		}
364	}
365	if (m == NULL)
366		return;
367	m->m_pkthdr.rcvif = NULL;
368
369	if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
370		m->m_flags |= M_MCAST;
371		im6o.im6o_multicast_ifp = ifp;
372		im6o.im6o_multicast_hlim = 255;
373		im6o.im6o_multicast_loop = 0;
374	}
375
376	icmp6len = sizeof(*nd_ns);
377	m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
378	m->m_data += max_linkhdr;	/* or MH_ALIGN() equivalent? */
379
380	/* fill neighbor solicitation packet */
381	ip6 = mtod(m, struct ip6_hdr *);
382	ip6->ip6_flow = 0;
383	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
384	ip6->ip6_vfc |= IPV6_VERSION;
385	/* ip6->ip6_plen will be set later */
386	ip6->ip6_nxt = IPPROTO_ICMPV6;
387	ip6->ip6_hlim = 255;
388	if (daddr6)
389		ip6->ip6_dst = *daddr6;
390	else {
391		ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
392		ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index);
393		ip6->ip6_dst.s6_addr32[1] = 0;
394		ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
395		ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
396		ip6->ip6_dst.s6_addr8[12] = 0xff;
397	}
398	if (!dad) {
399		/*
400		 * RFC2461 7.2.2:
401		 * "If the source address of the packet prompting the
402		 * solicitation is the same as one of the addresses assigned
403		 * to the outgoing interface, that address SHOULD be placed
404		 * in the IP Source Address of the outgoing solicitation.
405		 * Otherwise, any one of the addresses assigned to the
406		 * interface should be used."
407		 *
408		 * We use the source address for the prompting packet
409		 * (saddr6), if:
410		 * - saddr6 is given from the caller (by giving "ln"), and
411		 * - saddr6 belongs to the outgoing interface.
412		 * Otherwise, we perform a scope-wise match.
413		 */
414		struct ip6_hdr *hip6;		/* hold ip6 */
415		struct in6_addr *saddr6;
416
417		if (ln && ln->ln_hold) {
418			hip6 = mtod(ln->ln_hold, struct ip6_hdr *);
419			/* XXX pullup? */
420			if (sizeof(*hip6) < ln->ln_hold->m_len)
421				saddr6 = &hip6->ip6_src;
422			else
423				saddr6 = NULL;
424		} else
425			saddr6 = NULL;
426		if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6))
427			bcopy(saddr6, &ip6->ip6_src, sizeof(*saddr6));
428		else {
429			ia = in6_ifawithifp(ifp, &ip6->ip6_dst);
430			if (ia == NULL) {
431				m_freem(m);
432				return;
433			}
434			ip6->ip6_src = ia->ia_addr.sin6_addr;
435		}
436	} else {
437		/*
438		 * Source address for DAD packet must always be IPv6
439		 * unspecified address. (0::0)
440		 */
441		bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
442	}
443	nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
444	nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
445	nd_ns->nd_ns_code = 0;
446	nd_ns->nd_ns_reserved = 0;
447	nd_ns->nd_ns_target = *taddr6;
448	in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
449
450	/*
451	 * Add source link-layer address option.
452	 *
453	 *				spec		implementation
454	 *				---		---
455	 * DAD packet			MUST NOT	do not add the option
456	 * there's no link layer address:
457	 *				impossible	do not add the option
458	 * there's link layer address:
459	 *	Multicast NS		MUST add one	add the option
460	 *	Unicast NS		SHOULD add one	add the option
461	 */
462	if (!dad && (mac = nd6_ifptomac(ifp))) {
463		int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
464		struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
465		/* 8 byte alignments... */
466		optlen = (optlen + 7) & ~7;
467
468		m->m_pkthdr.len += optlen;
469		m->m_len += optlen;
470		icmp6len += optlen;
471		bzero((caddr_t)nd_opt, optlen);
472		nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
473		nd_opt->nd_opt_len = optlen >> 3;
474		bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
475	}
476
477	ip6->ip6_plen = htons((u_short)icmp6len);
478	nd_ns->nd_ns_cksum = 0;
479	nd_ns->nd_ns_cksum =
480	    in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
481
482	ip6_output(m, NULL, NULL, dad ? IPV6_DADOUTPUT : 0, &im6o, &outif, NULL);
483	if (outif) {
484		icmp6_ifstat_inc(outif, ifs6_out_msg);
485		icmp6_ifstat_inc(outif, ifs6_out_neighborsolicit);
486	}
487	icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++;
488}
489
490/*
491 * Neighbor advertisement input handling.
492 *
493 * Based on RFC 2461
494 * Based on RFC 2462 (duplicated address detection)
495 *
496 * the following items are not implemented yet:
497 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
498 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
499 */
500void
501nd6_na_input(m, off, icmp6len)
502	struct mbuf *m;
503	int off, icmp6len;
504{
505	struct ifnet *ifp = m->m_pkthdr.rcvif;
506	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
507	struct nd_neighbor_advert *nd_na;
508	struct in6_addr daddr6 = ip6->ip6_dst;
509	struct in6_addr taddr6;
510	int flags;
511	int is_router;
512	int is_solicited;
513	int is_override;
514	char *lladdr = NULL;
515	int lladdrlen = 0;
516	struct ifaddr *ifa;
517	struct llinfo_nd6 *ln;
518	struct rtentry *rt;
519	struct sockaddr_dl *sdl;
520	union nd_opts ndopts;
521
522	if (ip6->ip6_hlim != 255) {
523		nd6log((LOG_ERR,
524		    "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
525		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
526		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
527		goto bad;
528	}
529
530#ifndef PULLDOWN_TEST
531	IP6_EXTHDR_CHECK(m, off, icmp6len,);
532	nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
533#else
534	IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
535	if (nd_na == NULL) {
536		icmp6stat.icp6s_tooshort++;
537		return;
538	}
539#endif
540	taddr6 = nd_na->nd_na_target;
541	flags = nd_na->nd_na_flags_reserved;
542	is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
543	is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
544	is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
545
546	if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
547		taddr6.s6_addr16[1] = htons(ifp->if_index);
548
549	if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
550		nd6log((LOG_ERR,
551		    "nd6_na_input: invalid target address %s\n",
552		    ip6_sprintf(&taddr6)));
553		goto bad;
554	}
555	if (IN6_IS_ADDR_MULTICAST(&daddr6))
556		if (is_solicited) {
557			nd6log((LOG_ERR,
558			    "nd6_na_input: a solicited adv is multicasted\n"));
559			goto bad;
560		}
561
562	icmp6len -= sizeof(*nd_na);
563	nd6_option_init(nd_na + 1, icmp6len, &ndopts);
564	if (nd6_options(&ndopts) < 0) {
565		nd6log((LOG_INFO,
566		    "nd6_na_input: invalid ND option, ignored\n"));
567		/* nd6_options have incremented stats */
568		goto freeit;
569	}
570
571	if (ndopts.nd_opts_tgt_lladdr) {
572		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
573		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
574	}
575
576	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
577
578	/*
579	 * Target address matches one of my interface address.
580	 *
581	 * If my address is tentative, this means that there's somebody
582	 * already using the same address as mine.  This indicates DAD failure.
583	 * This is defined in RFC 2462.
584	 *
585	 * Otherwise, process as defined in RFC 2461.
586	 */
587	if (ifa
588	 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
589		nd6_dad_na_input(ifa);
590		goto freeit;
591	}
592
593	/* Just for safety, maybe unnecessary. */
594	if (ifa) {
595		log(LOG_ERR,
596		    "nd6_na_input: duplicate IP6 address %s\n",
597		    ip6_sprintf(&taddr6));
598		goto freeit;
599	}
600
601	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
602		nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
603		    "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6),
604		    ifp->if_addrlen, lladdrlen - 2));
605		goto bad;
606	}
607
608	/*
609	 * If no neighbor cache entry is found, NA SHOULD silently be
610	 * discarded.
611	 */
612	rt = nd6_lookup(&taddr6, 0, ifp);
613	if ((rt == NULL) ||
614	   ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) ||
615	   ((sdl = SDL(rt->rt_gateway)) == NULL))
616		goto freeit;
617
618	if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
619		/*
620		 * If the link-layer has address, and no lladdr option came,
621		 * discard the packet.
622		 */
623		if (ifp->if_addrlen && !lladdr)
624			goto freeit;
625
626		/*
627		 * Record link-layer address, and update the state.
628		 */
629		sdl->sdl_alen = ifp->if_addrlen;
630		bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
631		if (is_solicited) {
632			ln->ln_state = ND6_LLINFO_REACHABLE;
633			ln->ln_byhint = 0;
634			if (ln->ln_expire) {
635				ln->ln_expire = time_second +
636				    ND_IFINFO(rt->rt_ifp)->reachable;
637			}
638		} else {
639			ln->ln_state = ND6_LLINFO_STALE;
640			ln->ln_expire = time_second + nd6_gctimer;
641		}
642		if ((ln->ln_router = is_router) != 0) {
643			/*
644			 * This means a router's state has changed from
645			 * non-reachable to probably reachable, and might
646			 * affect the status of associated prefixes..
647			 */
648			pfxlist_onlink_check();
649		}
650	} else {
651		int llchange;
652
653		/*
654		 * Check if the link-layer address has changed or not.
655		 */
656		if (!lladdr)
657			llchange = 0;
658		else {
659			if (sdl->sdl_alen) {
660				if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
661					llchange = 1;
662				else
663					llchange = 0;
664			} else
665				llchange = 1;
666		}
667
668		/*
669		 * This is VERY complex.  Look at it with care.
670		 *
671		 * override solicit lladdr llchange	action
672		 *					(L: record lladdr)
673		 *
674		 *	0	0	n	--	(2c)
675		 *	0	0	y	n	(2b) L
676		 *	0	0	y	y	(1)    REACHABLE->STALE
677		 *	0	1	n	--	(2c)   *->REACHABLE
678		 *	0	1	y	n	(2b) L *->REACHABLE
679		 *	0	1	y	y	(1)    REACHABLE->STALE
680		 *	1	0	n	--	(2a)
681		 *	1	0	y	n	(2a) L
682		 *	1	0	y	y	(2a) L *->STALE
683		 *	1	1	n	--	(2a)   *->REACHABLE
684		 *	1	1	y	n	(2a) L *->REACHABLE
685		 *	1	1	y	y	(2a) L *->REACHABLE
686		 */
687		if (!is_override && (lladdr && llchange)) {	   /* (1) */
688			/*
689			 * If state is REACHABLE, make it STALE.
690			 * no other updates should be done.
691			 */
692			if (ln->ln_state == ND6_LLINFO_REACHABLE) {
693				ln->ln_state = ND6_LLINFO_STALE;
694				ln->ln_expire = time_second + nd6_gctimer;
695			}
696			goto freeit;
697		} else if (is_override				   /* (2a) */
698			|| (!is_override && (lladdr && !llchange)) /* (2b) */
699			|| !lladdr) {				   /* (2c) */
700			/*
701			 * Update link-local address, if any.
702			 */
703			if (lladdr) {
704				sdl->sdl_alen = ifp->if_addrlen;
705				bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
706			}
707
708			/*
709			 * If solicited, make the state REACHABLE.
710			 * If not solicited and the link-layer address was
711			 * changed, make it STALE.
712			 */
713			if (is_solicited) {
714				ln->ln_state = ND6_LLINFO_REACHABLE;
715				ln->ln_byhint = 0;
716				if (ln->ln_expire) {
717					ln->ln_expire = time_second +
718					    ND_IFINFO(ifp)->reachable;
719				}
720			} else {
721				if (lladdr && llchange) {
722					ln->ln_state = ND6_LLINFO_STALE;
723					ln->ln_expire = time_second + nd6_gctimer;
724				}
725			}
726		}
727
728		if (ln->ln_router && !is_router) {
729			/*
730			 * The peer dropped the router flag.
731			 * Remove the sender from the Default Router List and
732			 * update the Destination Cache entries.
733			 */
734			struct nd_defrouter *dr;
735			struct in6_addr *in6;
736			int s;
737
738			in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
739
740			/*
741			 * Lock to protect the default router list.
742			 * XXX: this might be unnecessary, since this function
743			 * is only called under the network software interrupt
744			 * context.  However, we keep it just for safety.
745			 */
746			s = splnet();
747			dr = defrouter_lookup(in6, rt->rt_ifp);
748			if (dr)
749				defrtrlist_del(dr);
750			else if (!ip6_forwarding && ip6_accept_rtadv) {
751				/*
752				 * Even if the neighbor is not in the default
753				 * router list, the neighbor may be used
754				 * as a next hop for some destinations
755				 * (e.g. redirect case). So we must
756				 * call rt6_flush explicitly.
757				 */
758				rt6_flush(&ip6->ip6_src, rt->rt_ifp);
759			}
760			splx(s);
761		}
762		ln->ln_router = is_router;
763	}
764	rt->rt_flags &= ~RTF_REJECT;
765	ln->ln_asked = 0;
766	if (ln->ln_hold) {
767		/*
768		 * we assume ifp is not a loopback here, so just set the 2nd
769		 * argument as the 1st one.
770		 */
771		nd6_output(ifp, ifp, ln->ln_hold,
772			   (struct sockaddr_in6 *)rt_key(rt), rt);
773		ln->ln_hold = NULL;
774	}
775
776 freeit:
777	m_freem(m);
778	return;
779
780 bad:
781	icmp6stat.icp6s_badna++;
782	m_freem(m);
783}
784
785/*
786 * Neighbor advertisement output handling.
787 *
788 * Based on RFC 2461
789 *
790 * the following items are not implemented yet:
791 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
792 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
793 */
794void
795nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr, sdl0)
796	struct ifnet *ifp;
797	const struct in6_addr *daddr6, *taddr6;
798	u_long flags;
799	int tlladdr;		/* 1 if include target link-layer address */
800	struct sockaddr *sdl0;	/* sockaddr_dl (= proxy NA) or NULL */
801{
802	struct mbuf *m;
803	struct ip6_hdr *ip6;
804	struct nd_neighbor_advert *nd_na;
805	struct in6_ifaddr *ia = NULL;
806	struct ip6_moptions im6o;
807	int icmp6len;
808	int maxlen;
809	caddr_t mac = NULL;
810	struct ifnet *outif = NULL;
811
812	/* estimate the size of message */
813	maxlen = sizeof(*ip6) + sizeof(*nd_na);
814	maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
815	if (max_linkhdr + maxlen >= MCLBYTES) {
816#ifdef DIAGNOSTIC
817		printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
818		    "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
819#endif
820		return;
821	}
822
823	MGETHDR(m, M_DONTWAIT, MT_DATA);
824	if (m && max_linkhdr + maxlen >= MHLEN) {
825		MCLGET(m, M_DONTWAIT);
826		if ((m->m_flags & M_EXT) == 0) {
827			m_free(m);
828			m = NULL;
829		}
830	}
831	if (m == NULL)
832		return;
833	m->m_pkthdr.rcvif = NULL;
834
835	if (IN6_IS_ADDR_MULTICAST(daddr6)) {
836		m->m_flags |= M_MCAST;
837		im6o.im6o_multicast_ifp = ifp;
838		im6o.im6o_multicast_hlim = 255;
839		im6o.im6o_multicast_loop = 0;
840	}
841
842	icmp6len = sizeof(*nd_na);
843	m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
844	m->m_data += max_linkhdr;	/* or MH_ALIGN() equivalent? */
845
846	/* fill neighbor advertisement packet */
847	ip6 = mtod(m, struct ip6_hdr *);
848	ip6->ip6_flow = 0;
849	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
850	ip6->ip6_vfc |= IPV6_VERSION;
851	ip6->ip6_nxt = IPPROTO_ICMPV6;
852	ip6->ip6_hlim = 255;
853	if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) {
854		/* reply to DAD */
855		ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
856		ip6->ip6_dst.s6_addr16[1] = htons(ifp->if_index);
857		ip6->ip6_dst.s6_addr32[1] = 0;
858		ip6->ip6_dst.s6_addr32[2] = 0;
859		ip6->ip6_dst.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
860		flags &= ~ND_NA_FLAG_SOLICITED;
861	} else
862		ip6->ip6_dst = *daddr6;
863
864	/*
865	 * Select a source whose scope is the same as that of the dest.
866	 */
867	ia = in6_ifawithifp(ifp, &ip6->ip6_dst);
868	if (ia == NULL) {
869		m_freem(m);
870		return;
871	}
872	ip6->ip6_src = ia->ia_addr.sin6_addr;
873	nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
874	nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
875	nd_na->nd_na_code = 0;
876	nd_na->nd_na_target = *taddr6;
877	in6_clearscope(&nd_na->nd_na_target); /* XXX */
878
879	/*
880	 * "tlladdr" indicates NS's condition for adding tlladdr or not.
881	 * see nd6_ns_input() for details.
882	 * Basically, if NS packet is sent to unicast/anycast addr,
883	 * target lladdr option SHOULD NOT be included.
884	 */
885	if (tlladdr) {
886		/*
887		 * sdl0 != NULL indicates proxy NA.  If we do proxy, use
888		 * lladdr in sdl0.  If we are not proxying (sending NA for
889		 * my address) use lladdr configured for the interface.
890		 */
891		if (sdl0 == NULL)
892			mac = nd6_ifptomac(ifp);
893		else if (sdl0->sa_family == AF_LINK) {
894			struct sockaddr_dl *sdl;
895			sdl = (struct sockaddr_dl *)sdl0;
896			if (sdl->sdl_alen == ifp->if_addrlen)
897				mac = LLADDR(sdl);
898		}
899	}
900	if (tlladdr && mac) {
901		int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
902		struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
903
904		/* roundup to 8 bytes alignment! */
905		optlen = (optlen + 7) & ~7;
906
907		m->m_pkthdr.len += optlen;
908		m->m_len += optlen;
909		icmp6len += optlen;
910		bzero((caddr_t)nd_opt, optlen);
911		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
912		nd_opt->nd_opt_len = optlen >> 3;
913		bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
914	} else
915		flags &= ~ND_NA_FLAG_OVERRIDE;
916
917	ip6->ip6_plen = htons((u_short)icmp6len);
918	nd_na->nd_na_flags_reserved = flags;
919	nd_na->nd_na_cksum = 0;
920	nd_na->nd_na_cksum =
921	    in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
922
923	ip6_output(m, NULL, NULL, 0, &im6o, &outif, NULL);
924	if (outif) {
925		icmp6_ifstat_inc(outif, ifs6_out_msg);
926		icmp6_ifstat_inc(outif, ifs6_out_neighboradvert);
927	}
928	icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++;
929}
930
931caddr_t
932nd6_ifptomac(ifp)
933	struct ifnet *ifp;
934{
935	switch (ifp->if_type) {
936	case IFT_ARCNET:
937	case IFT_ETHER:
938	case IFT_FDDI:
939	case IFT_IEEE1394:
940#ifdef IFT_L2VLAN
941	case IFT_L2VLAN:
942#endif
943#ifdef IFT_IEEE80211
944	case IFT_IEEE80211:
945#endif
946	case IFT_ISO88025:
947		return ((caddr_t)(ifp + 1));
948	default:
949		return NULL;
950	}
951}
952
953TAILQ_HEAD(dadq_head, dadq);
954struct dadq {
955	TAILQ_ENTRY(dadq) dad_list;
956	struct ifaddr *dad_ifa;
957	int dad_count;		/* max NS to send */
958	int dad_ns_tcount;	/* # of trials to send NS */
959	int dad_ns_ocount;	/* NS sent so far */
960	int dad_ns_icount;
961	int dad_na_icount;
962	struct callout dad_timer_ch;
963};
964
965static struct dadq_head dadq;
966static int dad_init = 0;
967
968static struct dadq *
969nd6_dad_find(ifa)
970	struct ifaddr *ifa;
971{
972	struct dadq *dp;
973
974	for (dp = dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
975		if (dp->dad_ifa == ifa)
976			return dp;
977	}
978	return NULL;
979}
980
981static void
982nd6_dad_starttimer(dp, ticks)
983	struct dadq *dp;
984	int ticks;
985{
986
987	callout_reset(&dp->dad_timer_ch, ticks,
988	    (void (*) __P((void *)))nd6_dad_timer, (void *)dp->dad_ifa);
989}
990
991static void
992nd6_dad_stoptimer(dp)
993	struct dadq *dp;
994{
995
996	callout_stop(&dp->dad_timer_ch);
997}
998
999/*
1000 * Start Duplicated Address Detection (DAD) for specified interface address.
1001 */
1002void
1003nd6_dad_start(ifa, tick)
1004	struct ifaddr *ifa;
1005	int *tick;	/* minimum delay ticks for IFF_UP event */
1006{
1007	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1008	struct dadq *dp;
1009
1010	if (!dad_init) {
1011		TAILQ_INIT(&dadq);
1012		dad_init++;
1013	}
1014
1015	/*
1016	 * If we don't need DAD, don't do it.
1017	 * There are several cases:
1018	 * - DAD is disabled (ip6_dad_count == 0)
1019	 * - the interface address is anycast
1020	 */
1021	if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1022		log(LOG_DEBUG,
1023			"nd6_dad_start: called with non-tentative address "
1024			"%s(%s)\n",
1025			ip6_sprintf(&ia->ia_addr.sin6_addr),
1026			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1027		return;
1028	}
1029	if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1030		ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1031		return;
1032	}
1033	if (!ip6_dad_count) {
1034		ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1035		return;
1036	}
1037	if (!ifa->ifa_ifp)
1038		panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1039	if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
1040		return;
1041	}
1042	if (nd6_dad_find(ifa) != NULL) {
1043		/* DAD already in progress */
1044		return;
1045	}
1046
1047	dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
1048	if (dp == NULL) {
1049		log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1050			"%s(%s)\n",
1051			ip6_sprintf(&ia->ia_addr.sin6_addr),
1052			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1053		return;
1054	}
1055	bzero(dp, sizeof(*dp));
1056	callout_init(&dp->dad_timer_ch, 0);
1057	TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list);
1058
1059	nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1060	    ip6_sprintf(&ia->ia_addr.sin6_addr)));
1061
1062	/*
1063	 * Send NS packet for DAD, ip6_dad_count times.
1064	 * Note that we must delay the first transmission, if this is the
1065	 * first packet to be sent from the interface after interface
1066	 * (re)initialization.
1067	 */
1068	dp->dad_ifa = ifa;
1069	IFAREF(ifa);	/* just for safety */
1070	dp->dad_count = ip6_dad_count;
1071	dp->dad_ns_icount = dp->dad_na_icount = 0;
1072	dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1073	if (tick == NULL) {
1074		nd6_dad_ns_output(dp, ifa);
1075		nd6_dad_starttimer(dp,
1076		    ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1077	} else {
1078		int ntick;
1079
1080		if (*tick == 0)
1081			ntick = arc4random() % (MAX_RTR_SOLICITATION_DELAY * hz);
1082		else
1083			ntick = *tick + arc4random() % (hz / 2);
1084		*tick = ntick;
1085		nd6_dad_starttimer(dp, ntick);
1086	}
1087}
1088
1089/*
1090 * terminate DAD unconditionally.  used for address removals.
1091 */
1092void
1093nd6_dad_stop(ifa)
1094	struct ifaddr *ifa;
1095{
1096	struct dadq *dp;
1097
1098	if (!dad_init)
1099		return;
1100	dp = nd6_dad_find(ifa);
1101	if (!dp) {
1102		/* DAD wasn't started yet */
1103		return;
1104	}
1105
1106	nd6_dad_stoptimer(dp);
1107
1108	TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1109	free(dp, M_IP6NDP);
1110	dp = NULL;
1111	IFAFREE(ifa);
1112}
1113
1114static void
1115nd6_dad_timer(ifa)
1116	struct ifaddr *ifa;
1117{
1118	int s;
1119	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1120	struct dadq *dp;
1121
1122	s = splnet();		/* XXX */
1123
1124	/* Sanity check */
1125	if (ia == NULL) {
1126		log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1127		goto done;
1128	}
1129	dp = nd6_dad_find(ifa);
1130	if (dp == NULL) {
1131		log(LOG_ERR, "nd6_dad_timer: DAD structure not found\n");
1132		goto done;
1133	}
1134	if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1135		log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1136			"%s(%s)\n",
1137			ip6_sprintf(&ia->ia_addr.sin6_addr),
1138			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1139		goto done;
1140	}
1141	if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1142		log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1143			"%s(%s)\n",
1144			ip6_sprintf(&ia->ia_addr.sin6_addr),
1145			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1146		goto done;
1147	}
1148
1149	/* timeouted with IFF_{RUNNING,UP} check */
1150	if (dp->dad_ns_tcount > dad_maxtry) {
1151		nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
1152		    if_name(ifa->ifa_ifp)));
1153
1154		TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1155		free(dp, M_IP6NDP);
1156		dp = NULL;
1157		IFAFREE(ifa);
1158		goto done;
1159	}
1160
1161	/* Need more checks? */
1162	if (dp->dad_ns_ocount < dp->dad_count) {
1163		/*
1164		 * We have more NS to go.  Send NS packet for DAD.
1165		 */
1166		nd6_dad_ns_output(dp, ifa);
1167		nd6_dad_starttimer(dp,
1168		    ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1169	} else {
1170		/*
1171		 * We have transmitted sufficient number of DAD packets.
1172		 * See what we've got.
1173		 */
1174		int duplicate;
1175
1176		duplicate = 0;
1177
1178		if (dp->dad_na_icount) {
1179			/*
1180			 * the check is in nd6_dad_na_input(),
1181			 * but just in case
1182			 */
1183			duplicate++;
1184		}
1185
1186		if (dp->dad_ns_icount) {
1187#if 0 /* heuristics */
1188			/*
1189			 * if
1190			 * - we have sent many(?) DAD NS, and
1191			 * - the number of NS we sent equals to the
1192			 *   number of NS we've got, and
1193			 * - we've got no NA
1194			 * we may have a faulty network card/driver which
1195			 * loops back multicasts to myself.
1196			 */
1197			if (3 < dp->dad_count
1198			 && dp->dad_ns_icount == dp->dad_count
1199			 && dp->dad_na_icount == 0) {
1200				log(LOG_INFO, "DAD questionable for %s(%s): "
1201				    "network card loops back multicast?\n",
1202				    ip6_sprintf(&ia->ia_addr.sin6_addr),
1203				    if_name(ifa->ifa_ifp));
1204				/* XXX consider it a duplicate or not? */
1205				/* duplicate++; */
1206			} else {
1207				/* We've seen NS, means DAD has failed. */
1208				duplicate++;
1209			}
1210#else
1211			/* We've seen NS, means DAD has failed. */
1212			duplicate++;
1213#endif
1214		}
1215
1216		if (duplicate) {
1217			/* (*dp) will be freed in nd6_dad_duplicated() */
1218			dp = NULL;
1219			nd6_dad_duplicated(ifa);
1220		} else {
1221			/*
1222			 * We are done with DAD.  No NA came, no NS came.
1223			 * duplicated address found.
1224			 */
1225			ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1226
1227			nd6log((LOG_DEBUG,
1228			    "%s: DAD complete for %s - no duplicates found\n",
1229			    if_name(ifa->ifa_ifp),
1230			    ip6_sprintf(&ia->ia_addr.sin6_addr)));
1231
1232			TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1233			free(dp, M_IP6NDP);
1234			dp = NULL;
1235			IFAFREE(ifa);
1236		}
1237	}
1238
1239done:
1240	splx(s);
1241}
1242
1243void
1244nd6_dad_duplicated(ifa)
1245	struct ifaddr *ifa;
1246{
1247	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1248	struct dadq *dp;
1249
1250	dp = nd6_dad_find(ifa);
1251	if (dp == NULL) {
1252		log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
1253		return;
1254	}
1255
1256	log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1257	    "NS in/out=%d/%d, NA in=%d\n",
1258	    if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr),
1259	    dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
1260
1261	ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1262	ia->ia6_flags |= IN6_IFF_DUPLICATED;
1263
1264	/* We are done with DAD, with duplicated address found. (failure) */
1265	nd6_dad_stoptimer(dp);
1266
1267	log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1268	    if_name(ifa->ifa_ifp), ip6_sprintf(&ia->ia_addr.sin6_addr));
1269	log(LOG_ERR, "%s: manual intervention required\n",
1270	    if_name(ifa->ifa_ifp));
1271
1272	TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1273	free(dp, M_IP6NDP);
1274	dp = NULL;
1275	IFAFREE(ifa);
1276}
1277
1278static void
1279nd6_dad_ns_output(dp, ifa)
1280	struct dadq *dp;
1281	struct ifaddr *ifa;
1282{
1283	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1284	struct ifnet *ifp = ifa->ifa_ifp;
1285
1286	dp->dad_ns_tcount++;
1287	if ((ifp->if_flags & IFF_UP) == 0) {
1288#if 0
1289		printf("%s: interface down?\n", if_name(ifp));
1290#endif
1291		return;
1292	}
1293	if ((ifp->if_flags & IFF_RUNNING) == 0) {
1294#if 0
1295		printf("%s: interface not running?\n", if_name(ifp));
1296#endif
1297		return;
1298	}
1299
1300	dp->dad_ns_ocount++;
1301	nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
1302}
1303
1304static void
1305nd6_dad_ns_input(ifa)
1306	struct ifaddr *ifa;
1307{
1308	struct in6_ifaddr *ia;
1309	struct ifnet *ifp;
1310	const struct in6_addr *taddr6;
1311	struct dadq *dp;
1312	int duplicate;
1313
1314	if (!ifa)
1315		panic("ifa == NULL in nd6_dad_ns_input");
1316
1317	ia = (struct in6_ifaddr *)ifa;
1318	ifp = ifa->ifa_ifp;
1319	taddr6 = &ia->ia_addr.sin6_addr;
1320	duplicate = 0;
1321	dp = nd6_dad_find(ifa);
1322
1323	/* Quickhack - completely ignore DAD NS packets */
1324	if (dad_ignore_ns) {
1325		nd6log((LOG_INFO,
1326		    "nd6_dad_ns_input: ignoring DAD NS packet for "
1327		    "address %s(%s)\n", ip6_sprintf(taddr6),
1328		    if_name(ifa->ifa_ifp)));
1329		return;
1330	}
1331
1332	/*
1333	 * if I'm yet to start DAD, someone else started using this address
1334	 * first.  I have a duplicate and you win.
1335	 */
1336	if (!dp || dp->dad_ns_ocount == 0)
1337		duplicate++;
1338
1339	/* XXX more checks for loopback situation - see nd6_dad_timer too */
1340
1341	if (duplicate) {
1342		dp = NULL;	/* will be freed in nd6_dad_duplicated() */
1343		nd6_dad_duplicated(ifa);
1344	} else {
1345		/*
1346		 * not sure if I got a duplicate.
1347		 * increment ns count and see what happens.
1348		 */
1349		if (dp)
1350			dp->dad_ns_icount++;
1351	}
1352}
1353
1354static void
1355nd6_dad_na_input(ifa)
1356	struct ifaddr *ifa;
1357{
1358	struct dadq *dp;
1359
1360	if (!ifa)
1361		panic("ifa == NULL in nd6_dad_na_input");
1362
1363	dp = nd6_dad_find(ifa);
1364	if (dp)
1365		dp->dad_na_icount++;
1366
1367	/* remove the address. */
1368	nd6_dad_duplicated(ifa);
1369}
1370