xref: /netbsd-src/sys/netinet6/nd6_nbr.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: nd6_nbr.c,v 1.82 2007/11/16 17:51:51 dyoung Exp $	*/
2 /*	$KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 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 <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: nd6_nbr.c,v 1.82 2007/11/16 17:51:51 dyoung Exp $");
35 
36 #include "opt_inet.h"
37 #include "opt_ipsec.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/time.h>
46 #include <sys/kernel.h>
47 #include <sys/errno.h>
48 #include <sys/ioctl.h>
49 #include <sys/syslog.h>
50 #include <sys/queue.h>
51 #include <sys/callout.h>
52 
53 #include <net/if.h>
54 #include <net/if_types.h>
55 #include <net/if_dl.h>
56 #include <net/route.h>
57 
58 #include <netinet/in.h>
59 #include <netinet/in_var.h>
60 #include <netinet6/in6_var.h>
61 #include <netinet6/in6_ifattach.h>
62 #include <netinet/ip6.h>
63 #include <netinet6/ip6_var.h>
64 #include <netinet6/scope6_var.h>
65 #include <netinet6/nd6.h>
66 #include <netinet/icmp6.h>
67 
68 #ifdef IPSEC
69 #include <netinet6/ipsec.h>
70 #endif
71 
72 #include "carp.h"
73 #if NCARP > 0
74 #include <netinet/ip_carp.h>
75 #endif
76 
77 #include <net/net_osdep.h>
78 
79 struct dadq;
80 static struct dadq *nd6_dad_find(struct ifaddr *);
81 static void nd6_dad_starttimer(struct dadq *, int);
82 static void nd6_dad_stoptimer(struct dadq *);
83 static void nd6_dad_timer(struct ifaddr *);
84 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
85 static void nd6_dad_ns_input(struct ifaddr *);
86 static void nd6_dad_na_input(struct ifaddr *);
87 
88 static int dad_ignore_ns = 0;	/* ignore NS in DAD - specwise incorrect*/
89 static int dad_maxtry = 15;	/* max # of *tries* to transmit DAD packet */
90 
91 /*
92  * Input a Neighbor Solicitation Message.
93  *
94  * Based on RFC 2461
95  * Based on RFC 2462 (duplicate address detection)
96  */
97 void
98 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
99 {
100 	struct ifnet *ifp = m->m_pkthdr.rcvif;
101 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
102 	struct nd_neighbor_solicit *nd_ns;
103 	struct in6_addr saddr6 = ip6->ip6_src;
104 	struct in6_addr daddr6 = ip6->ip6_dst;
105 	struct in6_addr taddr6;
106 	struct in6_addr myaddr6;
107 	char *lladdr = NULL;
108 	struct ifaddr *ifa;
109 	int lladdrlen = 0;
110 	int anycast = 0, proxy = 0, tentative = 0;
111 	int router = ip6_forwarding;
112 	int tlladdr;
113 	union nd_opts ndopts;
114 	const struct sockaddr_dl *proxydl = NULL;
115 
116 	IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
117 	if (nd_ns == NULL) {
118 		icmp6stat.icp6s_tooshort++;
119 		return;
120 	}
121 	ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
122 	taddr6 = nd_ns->nd_ns_target;
123 	if (in6_setscope(&taddr6, ifp, NULL) != 0)
124 		goto bad;
125 
126 	if (ip6->ip6_hlim != 255) {
127 		nd6log((LOG_ERR,
128 		    "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
129 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
130 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
131 		goto bad;
132 	}
133 
134 	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
135 		/* dst has to be a solicited node multicast address. */
136 		/* don't check ifindex portion */
137 		if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
138 		    daddr6.s6_addr32[1] == 0 &&
139 		    daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
140 		    daddr6.s6_addr8[12] == 0xff) {
141 			; /* good */
142 		} else {
143 			nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
144 			    "(wrong ip6 dst)\n"));
145 			goto bad;
146 		}
147 	}
148 
149 	if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
150 		nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
151 		goto bad;
152 	}
153 
154 	icmp6len -= sizeof(*nd_ns);
155 	nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
156 	if (nd6_options(&ndopts) < 0) {
157 		nd6log((LOG_INFO,
158 		    "nd6_ns_input: invalid ND option, ignored\n"));
159 		/* nd6_options have incremented stats */
160 		goto freeit;
161 	}
162 
163 	if (ndopts.nd_opts_src_lladdr) {
164 		lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
165 		lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
166 	}
167 
168 	if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
169 		nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
170 		    "(link-layer address option)\n"));
171 		goto bad;
172 	}
173 
174 	/*
175 	 * Attaching target link-layer address to the NA?
176 	 * (RFC 2461 7.2.4)
177 	 *
178 	 * NS IP dst is multicast			MUST add
179 	 * Otherwise					MAY be omitted
180 	 *
181 	 * In this implementation, we omit the target link-layer address
182 	 * in the "MAY" case.
183 	 */
184 #if 0 /* too much! */
185 	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6);
186 	if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST))
187 		tlladdr = 0;
188 	else
189 #endif
190 	if (!IN6_IS_ADDR_MULTICAST(&daddr6))
191 		tlladdr = 0;
192 	else
193 		tlladdr = 1;
194 
195 	/*
196 	 * Target address (taddr6) must be either:
197 	 * (1) Valid unicast/anycast address for my receiving interface,
198 	 * (2) Unicast address for which I'm offering proxy service, or
199 	 * (3) "tentative" address on which DAD is being performed.
200 	 */
201 	/* (1) and (3) check. */
202 #if NCARP > 0
203 	if (ifp->if_carp && ifp->if_type != IFT_CARP)
204 		ifa = carp_iamatch6(ifp->if_carp, &taddr6);
205 	else
206 		ifa = NULL;
207 	if (!ifa)
208 		ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
209 #else
210 	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
211 #endif
212 
213 	/* (2) check. */
214 	if (ifa == NULL) {
215 		struct rtentry *rt;
216 		struct sockaddr_in6 tsin6;
217 
218 		sockaddr_in6_init(&tsin6, &taddr6, 0, 0, 0);
219 
220 		rt = rtalloc1((struct sockaddr *)&tsin6, 0);
221 		if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
222 		    rt->rt_gateway->sa_family == AF_LINK) {
223 			/*
224 			 * proxy NDP for single entry
225 			 */
226 			ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
227 				IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
228 			if (ifa) {
229 				proxy = 1;
230 				proxydl = satocsdl(rt->rt_gateway);
231 				router = 0;	/* XXX */
232 			}
233 		}
234 		if (rt)
235 			rtfree(rt);
236 	}
237 	if (ifa == NULL) {
238 		/*
239 		 * We've got an NS packet, and we don't have that address
240 		 * assigned for us.  We MUST silently ignore it.
241 		 * See RFC2461 7.2.3.
242 		 */
243 		goto freeit;
244 	}
245 	myaddr6 = *IFA_IN6(ifa);
246 	anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
247 	tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
248 	if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
249 		goto freeit;
250 
251 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
252 		nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
253 		    "(if %d, NS packet %d)\n",
254 		    ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2));
255 		goto bad;
256 	}
257 
258 	if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
259 		nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
260 		    ip6_sprintf(&saddr6)));
261 		goto freeit;
262 	}
263 
264 	/*
265 	 * We have neighbor solicitation packet, with target address equals to
266 	 * one of my tentative address.
267 	 *
268 	 * src addr	how to process?
269 	 * ---		---
270 	 * multicast	of course, invalid (rejected in ip6_input)
271 	 * unicast	somebody is doing address resolution -> ignore
272 	 * unspec	dup address detection
273 	 *
274 	 * The processing is defined in RFC 2462.
275 	 */
276 	if (tentative) {
277 		/*
278 		 * If source address is unspecified address, it is for
279 		 * duplicate address detection.
280 		 *
281 		 * If not, the packet is for addess resolution;
282 		 * silently ignore it.
283 		 */
284 		if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
285 			nd6_dad_ns_input(ifa);
286 
287 		goto freeit;
288 	}
289 
290 	/*
291 	 * If the source address is unspecified address, entries must not
292 	 * be created or updated.
293 	 * It looks that sender is performing DAD.  Output NA toward
294 	 * all-node multicast address, to tell the sender that I'm using
295 	 * the address.
296 	 * S bit ("solicited") must be zero.
297 	 */
298 	if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
299 		struct in6_addr in6_all;
300 
301 		in6_all = in6addr_linklocal_allnodes;
302 		if (in6_setscope(&in6_all, ifp, NULL) != 0)
303 			goto bad;
304 		nd6_na_output(ifp, &in6_all, &taddr6,
305 		    ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
306 		    (ip6_forwarding ? ND_NA_FLAG_ROUTER : 0),
307 		    tlladdr, (const struct sockaddr *)proxydl);
308 		goto freeit;
309 	}
310 
311 	nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0);
312 
313 	nd6_na_output(ifp, &saddr6, &taddr6,
314 	    ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
315 	    (router ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
316 	    tlladdr, (const struct sockaddr *)proxydl);
317  freeit:
318 	m_freem(m);
319 	return;
320 
321  bad:
322 	nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)));
323 	nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)));
324 	nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)));
325 	icmp6stat.icp6s_badns++;
326 	m_freem(m);
327 }
328 
329 /*
330  * Output a Neighbor Solicitation Message. Caller specifies:
331  *	- ICMP6 header source IP6 address
332  *	- ND6 header target IP6 address
333  *	- ND6 header source datalink address
334  *
335  * Based on RFC 2461
336  * Based on RFC 2462 (duplicate address detection)
337  */
338 void
339 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
340     const struct in6_addr *taddr6,
341     struct llinfo_nd6 *ln,	/* for source address determination */
342     int dad			/* duplicate address detection */)
343 {
344 	struct mbuf *m;
345 	struct ip6_hdr *ip6;
346 	struct nd_neighbor_solicit *nd_ns;
347 	struct in6_addr *src, src_in;
348 	struct ip6_moptions im6o;
349 	int icmp6len;
350 	int maxlen;
351 	const void *mac;
352 	struct route ro;
353 
354 	if (IN6_IS_ADDR_MULTICAST(taddr6))
355 		return;
356 
357 	memset(&ro, 0, sizeof(ro));
358 
359 	/* estimate the size of message */
360 	maxlen = sizeof(*ip6) + sizeof(*nd_ns);
361 	maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
362 #ifdef DIAGNOSTIC
363 	if (max_linkhdr + maxlen >= MCLBYTES) {
364 		printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
365 		    "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
366 		panic("nd6_ns_output: insufficient MCLBYTES");
367 		/* NOTREACHED */
368 	}
369 #endif
370 
371 	MGETHDR(m, M_DONTWAIT, MT_DATA);
372 	if (m && max_linkhdr + maxlen >= MHLEN) {
373 		MCLGET(m, M_DONTWAIT);
374 		if ((m->m_flags & M_EXT) == 0) {
375 			m_free(m);
376 			m = NULL;
377 		}
378 	}
379 	if (m == NULL)
380 		return;
381 	m->m_pkthdr.rcvif = NULL;
382 
383 	if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
384 		m->m_flags |= M_MCAST;
385 		im6o.im6o_multicast_ifp = ifp;
386 		im6o.im6o_multicast_hlim = 255;
387 		im6o.im6o_multicast_loop = 0;
388 	}
389 
390 	icmp6len = sizeof(*nd_ns);
391 	m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
392 	m->m_data += max_linkhdr;	/* or MH_ALIGN() equivalent? */
393 
394 	/* fill neighbor solicitation packet */
395 	ip6 = mtod(m, struct ip6_hdr *);
396 	ip6->ip6_flow = 0;
397 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
398 	ip6->ip6_vfc |= IPV6_VERSION;
399 	/* ip6->ip6_plen will be set later */
400 	ip6->ip6_nxt = IPPROTO_ICMPV6;
401 	ip6->ip6_hlim = 255;
402 	if (daddr6)
403 		ip6->ip6_dst = *daddr6;
404 	else {
405 		ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
406 		ip6->ip6_dst.s6_addr16[1] = 0;
407 		ip6->ip6_dst.s6_addr32[1] = 0;
408 		ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
409 		ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
410 		ip6->ip6_dst.s6_addr8[12] = 0xff;
411 		if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
412 			goto bad;
413 	}
414 	if (!dad) {
415 		/*
416 		 * RFC2461 7.2.2:
417 		 * "If the source address of the packet prompting the
418 		 * solicitation is the same as one of the addresses assigned
419 		 * to the outgoing interface, that address SHOULD be placed
420 		 * in the IP Source Address of the outgoing solicitation.
421 		 * Otherwise, any one of the addresses assigned to the
422 		 * interface should be used."
423 		 *
424 		 * We use the source address for the prompting packet
425 		 * (hsrc), if:
426 		 * - hsrc is given from the caller (by giving "ln"), and
427 		 * - hsrc belongs to the outgoing interface.
428 		 * Otherwise, we perform the source address selection as usual.
429 		 */
430 		struct ip6_hdr *hip6;		/* hold ip6 */
431 		struct in6_addr *hsrc = NULL;
432 
433 		if (ln && ln->ln_hold) {
434 			/*
435 			 * assuming every packet in ln_hold has the same IP
436 			 * header
437 			 */
438 			hip6 = mtod(ln->ln_hold, struct ip6_hdr *);
439 			/* XXX pullup? */
440 			if (sizeof(*hip6) < ln->ln_hold->m_len)
441 				hsrc = &hip6->ip6_src;
442 			else
443 				hsrc = NULL;
444 		}
445 		if (hsrc && in6ifa_ifpwithaddr(ifp, hsrc))
446 			src = hsrc;
447 		else {
448 			int error;
449 			struct sockaddr_in6 dst_sa;
450 
451 			sockaddr_in6_init(&dst_sa, &ip6->ip6_dst, 0, 0, 0);
452 
453 			src = in6_selectsrc(&dst_sa, NULL,
454 			    NULL, &ro, NULL, NULL, &error);
455 			if (src == NULL) {
456 				nd6log((LOG_DEBUG,
457 				    "nd6_ns_output: source can't be "
458 				    "determined: dst=%s, error=%d\n",
459 				    ip6_sprintf(&dst_sa.sin6_addr), error));
460 				goto bad;
461 			}
462 		}
463 	} else {
464 		/*
465 		 * Source address for DAD packet must always be IPv6
466 		 * unspecified address. (0::0)
467 		 * We actually don't have to 0-clear the address (we did it
468 		 * above), but we do so here explicitly to make the intention
469 		 * clearer.
470 		 */
471 		bzero(&src_in, sizeof(src_in));
472 		src = &src_in;
473 	}
474 	ip6->ip6_src = *src;
475 	nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
476 	nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
477 	nd_ns->nd_ns_code = 0;
478 	nd_ns->nd_ns_reserved = 0;
479 	nd_ns->nd_ns_target = *taddr6;
480 	in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
481 
482 	/*
483 	 * Add source link-layer address option.
484 	 *
485 	 *				spec		implementation
486 	 *				---		---
487 	 * DAD packet			MUST NOT	do not add the option
488 	 * there's no link layer address:
489 	 *				impossible	do not add the option
490 	 * there's link layer address:
491 	 *	Multicast NS		MUST add one	add the option
492 	 *	Unicast NS		SHOULD add one	add the option
493 	 */
494 	if (!dad && (mac = nd6_ifptomac(ifp))) {
495 		int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
496 		struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
497 		/* 8 byte alignments... */
498 		optlen = (optlen + 7) & ~7;
499 
500 		m->m_pkthdr.len += optlen;
501 		m->m_len += optlen;
502 		icmp6len += optlen;
503 		bzero((void *)nd_opt, optlen);
504 		nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
505 		nd_opt->nd_opt_len = optlen >> 3;
506 		bcopy(mac, (void *)(nd_opt + 1), ifp->if_addrlen);
507 	}
508 
509 	ip6->ip6_plen = htons((u_int16_t)icmp6len);
510 	nd_ns->nd_ns_cksum = 0;
511 	nd_ns->nd_ns_cksum =
512 	    in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
513 
514 	ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
515 	icmp6_ifstat_inc(ifp, ifs6_out_msg);
516 	icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
517 	icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++;
518 
519 	rtcache_free(&ro);
520 	return;
521 
522   bad:
523 	rtcache_free(&ro);
524 	m_freem(m);
525 	return;
526 }
527 
528 /*
529  * Neighbor advertisement input handling.
530  *
531  * Based on RFC 2461
532  * Based on RFC 2462 (duplicate address detection)
533  *
534  * the following items are not implemented yet:
535  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
536  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
537  */
538 void
539 nd6_na_input(struct mbuf *m, int off, int icmp6len)
540 {
541 	struct ifnet *ifp = m->m_pkthdr.rcvif;
542 	struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
543 	struct nd_neighbor_advert *nd_na;
544 #if 0
545 	struct in6_addr saddr6 = ip6->ip6_src;
546 #endif
547 	struct in6_addr daddr6 = ip6->ip6_dst;
548 	struct in6_addr taddr6;
549 	int flags;
550 	int is_router;
551 	int is_solicited;
552 	int is_override;
553 	char *lladdr = NULL;
554 	int lladdrlen = 0;
555 	struct ifaddr *ifa;
556 	struct llinfo_nd6 *ln;
557 	struct rtentry *rt;
558 	struct sockaddr_dl *sdl;
559 	union nd_opts ndopts;
560 
561 	if (ip6->ip6_hlim != 255) {
562 		nd6log((LOG_ERR,
563 		    "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
564 		    ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
565 		    ip6_sprintf(&ip6->ip6_dst), if_name(ifp)));
566 		goto bad;
567 	}
568 
569 	IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
570 	if (nd_na == NULL) {
571 		icmp6stat.icp6s_tooshort++;
572 		return;
573 	}
574 
575 	flags = nd_na->nd_na_flags_reserved;
576 	is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
577 	is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
578 	is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
579 
580 	taddr6 = nd_na->nd_na_target;
581 	if (in6_setscope(&taddr6, ifp, NULL))
582 		return;		/* XXX: impossible */
583 
584 	if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
585 		nd6log((LOG_ERR,
586 		    "nd6_na_input: invalid target address %s\n",
587 		    ip6_sprintf(&taddr6)));
588 		goto bad;
589 	}
590 	if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) {
591 		nd6log((LOG_ERR,
592 		    "nd6_na_input: a solicited adv is multicasted\n"));
593 		goto bad;
594 	}
595 
596 	icmp6len -= sizeof(*nd_na);
597 	nd6_option_init(nd_na + 1, icmp6len, &ndopts);
598 	if (nd6_options(&ndopts) < 0) {
599 		nd6log((LOG_INFO,
600 		    "nd6_na_input: invalid ND option, ignored\n"));
601 		/* nd6_options have incremented stats */
602 		goto freeit;
603 	}
604 
605 	if (ndopts.nd_opts_tgt_lladdr) {
606 		lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
607 		lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
608 	}
609 
610 	ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
611 
612 	/*
613 	 * Target address matches one of my interface address.
614 	 *
615 	 * If my address is tentative, this means that there's somebody
616 	 * already using the same address as mine.  This indicates DAD failure.
617 	 * This is defined in RFC 2462.
618 	 *
619 	 * Otherwise, process as defined in RFC 2461.
620 	 */
621 	if (ifa
622 	 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
623 		nd6_dad_na_input(ifa);
624 		goto freeit;
625 	}
626 
627 	/* Just for safety, maybe unnecessary. */
628 	if (ifa) {
629 		log(LOG_ERR,
630 		    "nd6_na_input: duplicate IP6 address %s\n",
631 		    ip6_sprintf(&taddr6));
632 		goto freeit;
633 	}
634 
635 	if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
636 		nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
637 		    "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6),
638 		    ifp->if_addrlen, lladdrlen - 2));
639 		goto bad;
640 	}
641 
642 	/*
643 	 * If no neighbor cache entry is found, NA SHOULD silently be
644 	 * discarded.
645 	 */
646 	rt = nd6_lookup(&taddr6, 0, ifp);
647 	if ((rt == NULL) ||
648 	   ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) ||
649 	   ((sdl = satosdl(rt->rt_gateway)) == NULL))
650 		goto freeit;
651 
652 	if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
653 		/*
654 		 * If the link-layer has address, and no lladdr option came,
655 		 * discard the packet.
656 		 */
657 		if (ifp->if_addrlen && !lladdr)
658 			goto freeit;
659 
660 		/*
661 		 * Record link-layer address, and update the state.
662 		 */
663 		(void)sockaddr_dl_setaddr(sdl, sdl->sdl_len, lladdr,
664 		    ifp->if_addrlen);
665 		if (is_solicited) {
666 			ln->ln_state = ND6_LLINFO_REACHABLE;
667 			ln->ln_byhint = 0;
668 			if (!ND6_LLINFO_PERMANENT(ln)) {
669 				nd6_llinfo_settimer(ln,
670 				    (long)ND_IFINFO(rt->rt_ifp)->reachable * hz);
671 			}
672 		} else {
673 			ln->ln_state = ND6_LLINFO_STALE;
674 			nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
675 		}
676 		if ((ln->ln_router = is_router) != 0) {
677 			/*
678 			 * This means a router's state has changed from
679 			 * non-reachable to probably reachable, and might
680 			 * affect the status of associated prefixes..
681 			 */
682 			pfxlist_onlink_check();
683 		}
684 	} else {
685 		int llchange;
686 
687 		/*
688 		 * Check if the link-layer address has changed or not.
689 		 */
690 		if (lladdr == NULL)
691 			llchange = 0;
692 		else {
693 			if (sdl->sdl_alen) {
694 				if (bcmp(lladdr, CLLADDR(sdl), ifp->if_addrlen))
695 					llchange = 1;
696 				else
697 					llchange = 0;
698 			} else
699 				llchange = 1;
700 		}
701 
702 		/*
703 		 * This is VERY complex.  Look at it with care.
704 		 *
705 		 * override solicit lladdr llchange	action
706 		 *					(L: record lladdr)
707 		 *
708 		 *	0	0	n	--	(2c)
709 		 *	0	0	y	n	(2b) L
710 		 *	0	0	y	y	(1)    REACHABLE->STALE
711 		 *	0	1	n	--	(2c)   *->REACHABLE
712 		 *	0	1	y	n	(2b) L *->REACHABLE
713 		 *	0	1	y	y	(1)    REACHABLE->STALE
714 		 *	1	0	n	--	(2a)
715 		 *	1	0	y	n	(2a) L
716 		 *	1	0	y	y	(2a) L *->STALE
717 		 *	1	1	n	--	(2a)   *->REACHABLE
718 		 *	1	1	y	n	(2a) L *->REACHABLE
719 		 *	1	1	y	y	(2a) L *->REACHABLE
720 		 */
721 		if (!is_override && lladdr != NULL && llchange) { /* (1) */
722 			/*
723 			 * If state is REACHABLE, make it STALE.
724 			 * no other updates should be done.
725 			 */
726 			if (ln->ln_state == ND6_LLINFO_REACHABLE) {
727 				ln->ln_state = ND6_LLINFO_STALE;
728 				nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
729 			}
730 			goto freeit;
731 		} else if (is_override				   /* (2a) */
732 		    || (!is_override && lladdr != NULL && !llchange) /* (2b) */
733 		    || lladdr == NULL) {			   /* (2c) */
734 			/*
735 			 * Update link-local address, if any.
736 			 */
737 			if (lladdr != NULL) {
738 				(void)sockaddr_dl_setaddr(sdl, sdl->sdl_len,
739 				    lladdr, ifp->if_addrlen);
740 			}
741 
742 			/*
743 			 * If solicited, make the state REACHABLE.
744 			 * If not solicited and the link-layer address was
745 			 * changed, make it STALE.
746 			 */
747 			if (is_solicited) {
748 				ln->ln_state = ND6_LLINFO_REACHABLE;
749 				ln->ln_byhint = 0;
750 				if (!ND6_LLINFO_PERMANENT(ln)) {
751 					nd6_llinfo_settimer(ln,
752 					    (long)ND_IFINFO(ifp)->reachable * hz);
753 				}
754 			} else {
755 				if (lladdr && llchange) {
756 					ln->ln_state = ND6_LLINFO_STALE;
757 					nd6_llinfo_settimer(ln,
758 					    (long)nd6_gctimer * hz);
759 				}
760 			}
761 		}
762 
763 		if (ln->ln_router && !is_router) {
764 			/*
765 			 * The peer dropped the router flag.
766 			 * Remove the sender from the Default Router List and
767 			 * update the Destination Cache entries.
768 			 */
769 			struct nd_defrouter *dr;
770 			const struct in6_addr *in6;
771 			int s;
772 
773 			in6 = &satocsin6(rt_getkey(rt))->sin6_addr;
774 
775 			/*
776 			 * Lock to protect the default router list.
777 			 * XXX: this might be unnecessary, since this function
778 			 * is only called under the network software interrupt
779 			 * context.  However, we keep it just for safety.
780 			 */
781 			s = splsoftnet();
782 			dr = defrouter_lookup(in6, rt->rt_ifp);
783 			if (dr)
784 				defrtrlist_del(dr);
785 			else if (!ip6_forwarding) {
786 				/*
787 				 * Even if the neighbor is not in the default
788 				 * router list, the neighbor may be used
789 				 * as a next hop for some destinations
790 				 * (e.g. redirect case). So we must
791 				 * call rt6_flush explicitly.
792 				 */
793 				rt6_flush(&ip6->ip6_src, rt->rt_ifp);
794 			}
795 			splx(s);
796 		}
797 		ln->ln_router = is_router;
798 	}
799 	rt->rt_flags &= ~RTF_REJECT;
800 	ln->ln_asked = 0;
801 	nd6_llinfo_release_pkts(ln, ifp, rt);
802 
803  freeit:
804 	m_freem(m);
805 	return;
806 
807  bad:
808 	icmp6stat.icp6s_badna++;
809 	m_freem(m);
810 }
811 
812 /*
813  * Neighbor advertisement output handling.
814  *
815  * Based on RFC 2461
816  *
817  * the following items are not implemented yet:
818  * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
819  * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
820  */
821 void
822 nd6_na_output(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0)
823 	struct ifnet *ifp;
824 	const struct in6_addr *daddr6_0, *taddr6;
825 	u_long flags;
826 	int tlladdr;		/* 1 if include target link-layer address */
827 	const struct sockaddr *sdl0;	/* sockaddr_dl (= proxy NA) or NULL */
828 {
829 	struct mbuf *m;
830 	struct ip6_hdr *ip6;
831 	struct nd_neighbor_advert *nd_na;
832 	struct ip6_moptions im6o;
833 	struct sockaddr *dst;
834 	union {
835 		struct sockaddr		dst;
836 		struct sockaddr_in6	dst6;
837 	} u;
838 	struct in6_addr *src, daddr6;
839 	int icmp6len, maxlen, error;
840 	const void *mac;
841 	struct route ro;
842 
843 	mac = NULL;
844 	memset(&ro, 0, sizeof(ro));
845 
846 	daddr6 = *daddr6_0;	/* make a local copy for modification */
847 
848 	/* estimate the size of message */
849 	maxlen = sizeof(*ip6) + sizeof(*nd_na);
850 	maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
851 #ifdef DIAGNOSTIC
852 	if (max_linkhdr + maxlen >= MCLBYTES) {
853 		printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
854 		    "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
855 		panic("nd6_na_output: insufficient MCLBYTES");
856 		/* NOTREACHED */
857 	}
858 #endif
859 
860 	MGETHDR(m, M_DONTWAIT, MT_DATA);
861 	if (m && max_linkhdr + maxlen >= MHLEN) {
862 		MCLGET(m, M_DONTWAIT);
863 		if ((m->m_flags & M_EXT) == 0) {
864 			m_free(m);
865 			m = NULL;
866 		}
867 	}
868 	if (m == NULL)
869 		return;
870 	m->m_pkthdr.rcvif = NULL;
871 
872 	if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
873 		m->m_flags |= M_MCAST;
874 		im6o.im6o_multicast_ifp = ifp;
875 		im6o.im6o_multicast_hlim = 255;
876 		im6o.im6o_multicast_loop = 0;
877 	}
878 
879 	icmp6len = sizeof(*nd_na);
880 	m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
881 	m->m_data += max_linkhdr;	/* or MH_ALIGN() equivalent? */
882 
883 	/* fill neighbor advertisement packet */
884 	ip6 = mtod(m, struct ip6_hdr *);
885 	ip6->ip6_flow = 0;
886 	ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
887 	ip6->ip6_vfc |= IPV6_VERSION;
888 	ip6->ip6_nxt = IPPROTO_ICMPV6;
889 	ip6->ip6_hlim = 255;
890 	if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
891 		/* reply to DAD */
892 		daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
893 		daddr6.s6_addr16[1] = 0;
894 		daddr6.s6_addr32[1] = 0;
895 		daddr6.s6_addr32[2] = 0;
896 		daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
897 		if (in6_setscope(&daddr6, ifp, NULL))
898 			goto bad;
899 
900 		flags &= ~ND_NA_FLAG_SOLICITED;
901 	}
902 	ip6->ip6_dst = daddr6;
903 	sockaddr_in6_init(&u.dst6, &daddr6, 0, 0, 0);
904 	dst = &u.dst;
905 	rtcache_setdst(&ro, dst);
906 
907 	/*
908 	 * Select a source whose scope is the same as that of the dest.
909 	 */
910 	src = in6_selectsrc(satosin6(dst), NULL, NULL, &ro, NULL, NULL,
911 	    &error);
912 	if (src == NULL) {
913 		nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
914 		    "determined: dst=%s, error=%d\n",
915 		    ip6_sprintf(&satocsin6(dst)->sin6_addr), error));
916 		goto bad;
917 	}
918 	ip6->ip6_src = *src;
919 	nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
920 	nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
921 	nd_na->nd_na_code = 0;
922 	nd_na->nd_na_target = *taddr6;
923 	in6_clearscope(&nd_na->nd_na_target); /* XXX */
924 
925 	/*
926 	 * "tlladdr" indicates NS's condition for adding tlladdr or not.
927 	 * see nd6_ns_input() for details.
928 	 * Basically, if NS packet is sent to unicast/anycast addr,
929 	 * target lladdr option SHOULD NOT be included.
930 	 */
931 	if (tlladdr) {
932 		/*
933 		 * sdl0 != NULL indicates proxy NA.  If we do proxy, use
934 		 * lladdr in sdl0.  If we are not proxying (sending NA for
935 		 * my address) use lladdr configured for the interface.
936 		 */
937 		if (sdl0 == NULL)
938 			mac = nd6_ifptomac(ifp);
939 		else if (sdl0->sa_family == AF_LINK) {
940 			const struct sockaddr_dl *sdl;
941 			sdl = satocsdl(sdl0);
942 			if (sdl->sdl_alen == ifp->if_addrlen)
943 				mac = CLLADDR(sdl);
944 		}
945 	}
946 	if (tlladdr && mac) {
947 		int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
948 		struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
949 
950 		/* roundup to 8 bytes alignment! */
951 		optlen = (optlen + 7) & ~7;
952 
953 		m->m_pkthdr.len += optlen;
954 		m->m_len += optlen;
955 		icmp6len += optlen;
956 		bzero((void *)nd_opt, optlen);
957 		nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
958 		nd_opt->nd_opt_len = optlen >> 3;
959 		bcopy(mac, (void *)(nd_opt + 1), ifp->if_addrlen);
960 	} else
961 		flags &= ~ND_NA_FLAG_OVERRIDE;
962 
963 	ip6->ip6_plen = htons((u_int16_t)icmp6len);
964 	nd_na->nd_na_flags_reserved = flags;
965 	nd_na->nd_na_cksum = 0;
966 	nd_na->nd_na_cksum =
967 	    in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
968 
969 	ip6_output(m, NULL, NULL, 0, &im6o, (struct socket *)NULL, NULL);
970 
971 	icmp6_ifstat_inc(ifp, ifs6_out_msg);
972 	icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
973 	icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++;
974 
975 	rtcache_free(&ro);
976 	return;
977 
978   bad:
979 	rtcache_free(&ro);
980 	m_freem(m);
981 	return;
982 }
983 
984 const void *
985 nd6_ifptomac(const struct ifnet *ifp)
986 {
987 	switch (ifp->if_type) {
988 	case IFT_ARCNET:
989 	case IFT_ETHER:
990 	case IFT_FDDI:
991 	case IFT_IEEE1394:
992 	case IFT_PROPVIRTUAL:
993 	case IFT_CARP:
994 	case IFT_L2VLAN:
995 	case IFT_IEEE80211:
996 		return CLLADDR(ifp->if_sadl);
997 	default:
998 		return NULL;
999 	}
1000 }
1001 
1002 TAILQ_HEAD(dadq_head, dadq);
1003 struct dadq {
1004 	TAILQ_ENTRY(dadq) dad_list;
1005 	struct ifaddr *dad_ifa;
1006 	int dad_count;		/* max NS to send */
1007 	int dad_ns_tcount;	/* # of trials to send NS */
1008 	int dad_ns_ocount;	/* NS sent so far */
1009 	int dad_ns_icount;
1010 	int dad_na_icount;
1011 	struct callout dad_timer_ch;
1012 };
1013 
1014 static struct dadq_head dadq;
1015 static int dad_init = 0;
1016 
1017 static struct dadq *
1018 nd6_dad_find(struct ifaddr *ifa)
1019 {
1020 	struct dadq *dp;
1021 
1022 	TAILQ_FOREACH(dp, &dadq, dad_list) {
1023 		if (dp->dad_ifa == ifa)
1024 			return dp;
1025 	}
1026 	return NULL;
1027 }
1028 
1029 static void
1030 nd6_dad_starttimer(struct dadq *dp, int ticks)
1031 {
1032 
1033 	callout_reset(&dp->dad_timer_ch, ticks,
1034 	    (void (*)(void *))nd6_dad_timer, (void *)dp->dad_ifa);
1035 }
1036 
1037 static void
1038 nd6_dad_stoptimer(struct dadq *dp)
1039 {
1040 
1041 	callout_stop(&dp->dad_timer_ch);
1042 }
1043 
1044 /*
1045  * Start Duplicate Address Detection (DAD) for specified interface address.
1046  *
1047  * xtick: minimum delay ticks for IFF_UP event
1048  */
1049 void
1050 nd6_dad_start(struct ifaddr *ifa, int xtick)
1051 {
1052 	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1053 	struct dadq *dp;
1054 
1055 	if (!dad_init) {
1056 		TAILQ_INIT(&dadq);
1057 		dad_init++;
1058 	}
1059 
1060 	/*
1061 	 * If we don't need DAD, don't do it.
1062 	 * There are several cases:
1063 	 * - DAD is disabled (ip6_dad_count == 0)
1064 	 * - the interface address is anycast
1065 	 */
1066 	if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1067 		log(LOG_DEBUG,
1068 			"nd6_dad_start: called with non-tentative address "
1069 			"%s(%s)\n",
1070 			ip6_sprintf(&ia->ia_addr.sin6_addr),
1071 			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1072 		return;
1073 	}
1074 	if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1075 		ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1076 		return;
1077 	}
1078 	if (!ip6_dad_count) {
1079 		ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1080 		return;
1081 	}
1082 	if (ifa->ifa_ifp == NULL)
1083 		panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1084 	if (!(ifa->ifa_ifp->if_flags & IFF_UP))
1085 		return;
1086 	if (nd6_dad_find(ifa) != NULL) {
1087 		/* DAD already in progress */
1088 		return;
1089 	}
1090 
1091 	dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
1092 	if (dp == NULL) {
1093 		log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1094 			"%s(%s)\n",
1095 			ip6_sprintf(&ia->ia_addr.sin6_addr),
1096 			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1097 		return;
1098 	}
1099 	bzero(dp, sizeof(*dp));
1100 	callout_init(&dp->dad_timer_ch, 0);
1101 	TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list);
1102 
1103 	nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1104 	    ip6_sprintf(&ia->ia_addr.sin6_addr)));
1105 
1106 	/*
1107 	 * Send NS packet for DAD, ip6_dad_count times.
1108 	 * Note that we must delay the first transmission, if this is the
1109 	 * first packet to be sent from the interface after interface
1110 	 * (re)initialization.
1111 	 */
1112 	dp->dad_ifa = ifa;
1113 	IFAREF(ifa);	/* just for safety */
1114 	dp->dad_count = ip6_dad_count;
1115 	dp->dad_ns_icount = dp->dad_na_icount = 0;
1116 	dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1117 	if (xtick == 0) {
1118 		nd6_dad_ns_output(dp, ifa);
1119 		nd6_dad_starttimer(dp,
1120 		    (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1121 	} else
1122 		nd6_dad_starttimer(dp, xtick);
1123 }
1124 
1125 /*
1126  * terminate DAD unconditionally.  used for address removals.
1127  */
1128 void
1129 nd6_dad_stop(struct ifaddr *ifa)
1130 {
1131 	struct dadq *dp;
1132 
1133 	if (!dad_init)
1134 		return;
1135 	dp = nd6_dad_find(ifa);
1136 	if (dp == NULL) {
1137 		/* DAD wasn't started yet */
1138 		return;
1139 	}
1140 
1141 	nd6_dad_stoptimer(dp);
1142 
1143 	TAILQ_REMOVE(&dadq, dp, dad_list);
1144 	free(dp, M_IP6NDP);
1145 	dp = NULL;
1146 	IFAFREE(ifa);
1147 }
1148 
1149 static void
1150 nd6_dad_timer(struct ifaddr *ifa)
1151 {
1152 	int s;
1153 	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1154 	struct dadq *dp;
1155 
1156 	s = splsoftnet();	/* XXX */
1157 
1158 	/* Sanity check */
1159 	if (ia == NULL) {
1160 		log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1161 		goto done;
1162 	}
1163 	dp = nd6_dad_find(ifa);
1164 	if (dp == NULL) {
1165 		log(LOG_ERR, "nd6_dad_timer: DAD structure not found\n");
1166 		goto done;
1167 	}
1168 	if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1169 		log(LOG_ERR, "nd6_dad_timer: called with duplicate address "
1170 			"%s(%s)\n",
1171 			ip6_sprintf(&ia->ia_addr.sin6_addr),
1172 			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1173 		goto done;
1174 	}
1175 	if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1176 		log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1177 			"%s(%s)\n",
1178 			ip6_sprintf(&ia->ia_addr.sin6_addr),
1179 			ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1180 		goto done;
1181 	}
1182 
1183 	/* timeouted with IFF_{RUNNING,UP} check */
1184 	if (dp->dad_ns_tcount > dad_maxtry) {
1185 		nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
1186 			if_name(ifa->ifa_ifp)));
1187 
1188 		TAILQ_REMOVE(&dadq, dp, dad_list);
1189 		free(dp, M_IP6NDP);
1190 		dp = NULL;
1191 		IFAFREE(ifa);
1192 		goto done;
1193 	}
1194 
1195 	/* Need more checks? */
1196 	if (dp->dad_ns_ocount < dp->dad_count) {
1197 		/*
1198 		 * We have more NS to go.  Send NS packet for DAD.
1199 		 */
1200 		nd6_dad_ns_output(dp, ifa);
1201 		nd6_dad_starttimer(dp,
1202 		    (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1203 	} else {
1204 		/*
1205 		 * We have transmitted sufficient number of DAD packets.
1206 		 * See what we've got.
1207 		 */
1208 		int duplicate;
1209 
1210 		duplicate = 0;
1211 
1212 		if (dp->dad_na_icount) {
1213 			/*
1214 			 * the check is in nd6_dad_na_input(),
1215 			 * but just in case
1216 			 */
1217 			duplicate++;
1218 		}
1219 
1220 		if (dp->dad_ns_icount) {
1221 			/* We've seen NS, means DAD has failed. */
1222 			duplicate++;
1223 		}
1224 
1225 		if (duplicate) {
1226 			/* (*dp) will be freed in nd6_dad_duplicated() */
1227 			dp = NULL;
1228 			nd6_dad_duplicated(ifa);
1229 		} else {
1230 			/*
1231 			 * We are done with DAD.  No NA came, no NS came.
1232 			 * No duplicate address found.
1233 			 */
1234 			ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1235 
1236 			nd6log((LOG_DEBUG,
1237 			    "%s: DAD complete for %s - no duplicates found\n",
1238 			    if_name(ifa->ifa_ifp),
1239 			    ip6_sprintf(&ia->ia_addr.sin6_addr)));
1240 
1241 			TAILQ_REMOVE(&dadq, dp, dad_list);
1242 			free(dp, M_IP6NDP);
1243 			dp = NULL;
1244 			IFAFREE(ifa);
1245 		}
1246 	}
1247 
1248 done:
1249 	splx(s);
1250 }
1251 
1252 void
1253 nd6_dad_duplicated(struct ifaddr *ifa)
1254 {
1255 	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1256 	struct ifnet *ifp;
1257 	struct dadq *dp;
1258 
1259 	dp = nd6_dad_find(ifa);
1260 	if (dp == NULL) {
1261 		log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
1262 		return;
1263 	}
1264 
1265 	ifp = ifa->ifa_ifp;
1266 	log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1267 	    "NS in/out=%d/%d, NA in=%d\n",
1268 	    if_name(ifp), ip6_sprintf(&ia->ia_addr.sin6_addr),
1269 	    dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
1270 
1271 	ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1272 	ia->ia6_flags |= IN6_IFF_DUPLICATED;
1273 
1274 	/* We are done with DAD, with duplicated address found. (failure) */
1275 	nd6_dad_stoptimer(dp);
1276 
1277 	log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1278 	    if_name(ifp), ip6_sprintf(&ia->ia_addr.sin6_addr));
1279 	log(LOG_ERR, "%s: manual intervention required\n",
1280 	    if_name(ifp));
1281 
1282 	/*
1283 	 * If the address is a link-local address formed from an interface
1284 	 * identifier based on the hardware address which is supposed to be
1285 	 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1286 	 * operation on the interface SHOULD be disabled.
1287 	 * [rfc2462bis-03 Section 5.4.5]
1288 	 */
1289 	if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1290 		struct in6_addr in6;
1291 
1292 		/*
1293 		 * To avoid over-reaction, we only apply this logic when we are
1294 		 * very sure that hardware addresses are supposed to be unique.
1295 		 */
1296 		switch (ifp->if_type) {
1297 		case IFT_ETHER:
1298 		case IFT_FDDI:
1299 		case IFT_ATM:
1300 		case IFT_IEEE1394:
1301 #ifdef IFT_IEEE80211
1302 		case IFT_IEEE80211:
1303 #endif
1304 			in6 = ia->ia_addr.sin6_addr;
1305 			if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1306 			    IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1307 				ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1308 				log(LOG_ERR, "%s: possible hardware address "
1309 				    "duplication detected, disable IPv6\n",
1310 				    if_name(ifp));
1311 			}
1312 			break;
1313 		}
1314 	}
1315 
1316 	TAILQ_REMOVE(&dadq, dp, dad_list);
1317 	free(dp, M_IP6NDP);
1318 	dp = NULL;
1319 	IFAFREE(ifa);
1320 }
1321 
1322 static void
1323 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
1324 {
1325 	struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1326 	struct ifnet *ifp = ifa->ifa_ifp;
1327 
1328 	dp->dad_ns_tcount++;
1329 	if ((ifp->if_flags & IFF_UP) == 0) {
1330 #if 0
1331 		printf("%s: interface down?\n", if_name(ifp));
1332 #endif
1333 		return;
1334 	}
1335 	if ((ifp->if_flags & IFF_RUNNING) == 0) {
1336 #if 0
1337 		printf("%s: interface not running?\n", if_name(ifp));
1338 #endif
1339 		return;
1340 	}
1341 
1342 	dp->dad_ns_tcount = 0;
1343 	dp->dad_ns_ocount++;
1344 	nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
1345 }
1346 
1347 static void
1348 nd6_dad_ns_input(struct ifaddr *ifa)
1349 {
1350 	struct in6_ifaddr *ia;
1351 	const struct in6_addr *taddr6;
1352 	struct dadq *dp;
1353 	int duplicate;
1354 
1355 	if (ifa == NULL)
1356 		panic("ifa == NULL in nd6_dad_ns_input");
1357 
1358 	ia = (struct in6_ifaddr *)ifa;
1359 	taddr6 = &ia->ia_addr.sin6_addr;
1360 	duplicate = 0;
1361 	dp = nd6_dad_find(ifa);
1362 
1363 	/* Quickhack - completely ignore DAD NS packets */
1364 	if (dad_ignore_ns) {
1365 		nd6log((LOG_INFO,
1366 		    "nd6_dad_ns_input: ignoring DAD NS packet for "
1367 		    "address %s(%s)\n", ip6_sprintf(taddr6),
1368 		    if_name(ifa->ifa_ifp)));
1369 		return;
1370 	}
1371 
1372 	/*
1373 	 * if I'm yet to start DAD, someone else started using this address
1374 	 * first.  I have a duplicate and you win.
1375 	 */
1376 	if (dp == NULL || dp->dad_ns_ocount == 0)
1377 		duplicate++;
1378 
1379 	/* XXX more checks for loopback situation - see nd6_dad_timer too */
1380 
1381 	if (duplicate) {
1382 		dp = NULL;	/* will be freed in nd6_dad_duplicated() */
1383 		nd6_dad_duplicated(ifa);
1384 	} else {
1385 		/*
1386 		 * not sure if I got a duplicate.
1387 		 * increment ns count and see what happens.
1388 		 */
1389 		if (dp)
1390 			dp->dad_ns_icount++;
1391 	}
1392 }
1393 
1394 static void
1395 nd6_dad_na_input(struct ifaddr *ifa)
1396 {
1397 	struct dadq *dp;
1398 
1399 	if (ifa == NULL)
1400 		panic("ifa == NULL in nd6_dad_na_input");
1401 
1402 	dp = nd6_dad_find(ifa);
1403 	if (dp)
1404 		dp->dad_na_icount++;
1405 
1406 	/* remove the address. */
1407 	nd6_dad_duplicated(ifa);
1408 }
1409