1 /* $OpenBSD: nd6_nbr.c,v 1.37 2005/02/10 03:40:16 itojun 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/param.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/mbuf.h>
37 #include <sys/socket.h>
38 #include <sys/sockio.h>
39 #include <sys/time.h>
40 #include <sys/kernel.h>
41 #include <sys/errno.h>
42 #include <sys/ioctl.h>
43 #include <sys/syslog.h>
44 #include <sys/queue.h>
45 #include <sys/timeout.h>
46
47 #include <net/if.h>
48 #include <net/if_types.h>
49 #include <net/if_dl.h>
50 #include <net/route.h>
51
52 #include <netinet/in.h>
53 #include <netinet/in_var.h>
54 #include <netinet6/in6_var.h>
55 #include <netinet/ip6.h>
56 #include <netinet6/ip6_var.h>
57 #include <netinet6/nd6.h>
58 #include <netinet/icmp6.h>
59
60 #include <dev/rndvar.h>
61
62 #include "carp.h"
63 #if NCARP > 0
64 #include <netinet/ip_carp.h>
65 #endif
66
67 #define SDL(s) ((struct sockaddr_dl *)s)
68
69 struct dadq;
70 static struct dadq *nd6_dad_find(struct ifaddr *);
71 static void nd6_dad_starttimer(struct dadq *, int);
72 static void nd6_dad_stoptimer(struct dadq *);
73 static void nd6_dad_timer(struct ifaddr *);
74 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
75 static void nd6_dad_ns_input(struct ifaddr *);
76 static void nd6_dad_na_input(struct ifaddr *);
77
78 static int dad_ignore_ns = 0; /* ignore NS in DAD - specwise incorrect*/
79 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */
80
81 /*
82 * Input an Neighbor Solicitation Message.
83 *
84 * Based on RFC 2461
85 * Based on RFC 2462 (duplicated address detection)
86 */
87 void
nd6_ns_input(m,off,icmp6len)88 nd6_ns_input(m, off, icmp6len)
89 struct mbuf *m;
90 int off, icmp6len;
91 {
92 struct ifnet *ifp = m->m_pkthdr.rcvif;
93 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
94 struct nd_neighbor_solicit *nd_ns;
95 struct in6_addr saddr6 = ip6->ip6_src;
96 struct in6_addr daddr6 = ip6->ip6_dst;
97 struct in6_addr taddr6;
98 struct in6_addr myaddr6;
99 char *lladdr = NULL;
100 struct ifaddr *ifa = NULL;
101 int lladdrlen = 0;
102 int anycast = 0, proxy = 0, tentative = 0;
103 int router = ip6_forwarding;
104 int tlladdr;
105 union nd_opts ndopts;
106 struct sockaddr_dl *proxydl = NULL;
107
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 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
114 taddr6 = nd_ns->nd_ns_target;
115
116 if (ip6->ip6_hlim != 255) {
117 nd6log((LOG_ERR,
118 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
119 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
120 ip6_sprintf(&ip6->ip6_dst), ifp->if_xname));
121 goto bad;
122 }
123
124 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
125 /* dst has to be solicited node multicast address. */
126 /* don't check ifindex portion */
127 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
128 daddr6.s6_addr32[1] == 0 &&
129 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
130 daddr6.s6_addr8[12] == 0xff) {
131 ; /*good*/
132 } else {
133 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
134 "(wrong ip6 dst)\n"));
135 goto bad;
136 }
137 } else {
138 /*
139 * Make sure the source address is from a neighbor's address.
140 */
141 if (in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) {
142 nd6log((LOG_INFO, "nd6_ns_input: "
143 "NS packet from non-neighbor\n"));
144 goto bad;
145 }
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 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
155 taddr6.s6_addr16[1] = htons(ifp->if_index);
156
157 icmp6len -= sizeof(*nd_ns);
158 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
159 if (nd6_options(&ndopts) < 0) {
160 nd6log((LOG_INFO,
161 "nd6_ns_input: invalid ND option, ignored\n"));
162 /* nd6_options have incremented stats */
163 goto freeit;
164 }
165
166 if (ndopts.nd_opts_src_lladdr) {
167 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
168 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
169 }
170
171 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
172 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
173 "(link-layer address option)\n"));
174 goto bad;
175 }
176
177 /*
178 * Attaching target link-layer address to the NA?
179 * (RFC 2461 7.2.4)
180 *
181 * NS IP dst is unicast/anycast MUST NOT add
182 * NS IP dst is solicited-node multicast MUST add
183 *
184 * In implementation, we add target link-layer address by default.
185 * We do not add one in MUST NOT cases.
186 */
187 #if 0 /* too much! */
188 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &daddr6);
189 if (ifa && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST))
190 tlladdr = 0;
191 else
192 #endif
193 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
194 tlladdr = 0;
195 else
196 tlladdr = 1;
197
198 /*
199 * Target address (taddr6) must be either:
200 * (1) Valid unicast/anycast address for my receiving interface,
201 * (2) Unicast address for which I'm offering proxy service, or
202 * (3) "tentative" address on which DAD is being performed.
203 */
204 /* (1) and (3) check. */
205 #if NCARP > 0
206 if (ifp->if_carp
207 #ifdef IFT_CARP
208 && ifp->if_type != IFT_CARP
209 #endif
210 )
211 ifa = carp_iamatch6(ifp->if_carp, &taddr6);
212 if (!ifa)
213 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
214 #else
215 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
216 #endif
217
218 /* (2) check. */
219 if (!ifa) {
220 struct rtentry *rt;
221 struct sockaddr_in6 tsin6;
222
223 bzero(&tsin6, sizeof tsin6);
224 tsin6.sin6_len = sizeof(struct sockaddr_in6);
225 tsin6.sin6_family = AF_INET6;
226 tsin6.sin6_addr = taddr6;
227
228 rt = rtalloc1((struct sockaddr *)&tsin6, 0);
229 if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
230 rt->rt_gateway->sa_family == AF_LINK) {
231 /*
232 * proxy NDP for single entry
233 */
234 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
235 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
236 if (ifa) {
237 proxy = 1;
238 proxydl = SDL(rt->rt_gateway);
239 router = 0; /* XXX */
240 }
241 }
242 if (rt)
243 rtfree(rt);
244 }
245 if (!ifa) {
246 /*
247 * We've got an NS packet, and we don't have that adddress
248 * assigned for us. We MUST silently ignore it.
249 * See RFC2461 7.2.3.
250 */
251 goto freeit;
252 }
253 myaddr6 = *IFA_IN6(ifa);
254 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
255 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
256 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
257 goto freeit;
258
259 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
260 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
261 "(if %d, NS packet %d)\n",
262 ip6_sprintf(&taddr6), ifp->if_addrlen, lladdrlen - 2));
263 goto bad;
264 }
265
266 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
267 log(LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
268 ip6_sprintf(&saddr6));
269 goto freeit;
270 }
271
272 /*
273 * We have neighbor solicitation packet, with target address equals to
274 * one of my tentative address.
275 *
276 * src addr how to process?
277 * --- ---
278 * multicast of course, invalid (rejected in ip6_input)
279 * unicast somebody is doing address resolution -> ignore
280 * unspec dup address detection
281 *
282 * The processing is defined in RFC 2462.
283 */
284 if (tentative) {
285 /*
286 * If source address is unspecified address, it is for
287 * duplicated address detection.
288 *
289 * If not, the packet is for addess resolution;
290 * silently ignore it.
291 */
292 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
293 nd6_dad_ns_input(ifa);
294
295 goto freeit;
296 }
297
298 /*
299 * If the source address is unspecified address, entries must not
300 * be created or updated.
301 * It looks that sender is performing DAD. Output NA toward
302 * all-node multicast address, to tell the sender that I'm using
303 * the address.
304 * S bit ("solicited") must be zero.
305 */
306 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
307 saddr6 = in6addr_linklocal_allnodes;
308 saddr6.s6_addr16[1] = htons(ifp->if_index);
309 nd6_na_output(ifp, &saddr6, &taddr6,
310 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
311 (router ? ND_NA_FLAG_ROUTER : 0),
312 tlladdr, (struct sockaddr *)proxydl);
313 goto freeit;
314 }
315
316 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT, 0);
317
318 nd6_na_output(ifp, &saddr6, &taddr6,
319 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
320 (router ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
321 tlladdr, (struct sockaddr *)proxydl);
322 freeit:
323 m_freem(m);
324 return;
325
326 bad:
327 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n", ip6_sprintf(&saddr6)));
328 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n", ip6_sprintf(&daddr6)));
329 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n", ip6_sprintf(&taddr6)));
330 icmp6stat.icp6s_badns++;
331 m_freem(m);
332 }
333
334 /*
335 * Output an Neighbor Solicitation Message. Caller specifies:
336 * - ICMP6 header source IP6 address
337 * - ND6 header target IP6 address
338 * - ND6 header source datalink address
339 *
340 * Based on RFC 2461
341 * Based on RFC 2462 (duplicated address detection)
342 */
343 void
nd6_ns_output(ifp,daddr6,taddr6,ln,dad)344 nd6_ns_output(ifp, daddr6, taddr6, ln, dad)
345 struct ifnet *ifp;
346 struct in6_addr *daddr6, *taddr6;
347 struct llinfo_nd6 *ln; /* for source address determination */
348 int dad; /* duplicated address detection */
349 {
350 struct mbuf *m;
351 struct ip6_hdr *ip6;
352 struct nd_neighbor_solicit *nd_ns;
353 struct sockaddr_in6 src_sa, dst_sa;
354 struct ip6_moptions im6o;
355 int icmp6len;
356 int maxlen;
357 caddr_t mac;
358 struct route_in6 ro;
359
360 bzero(&ro, sizeof(ro));
361
362 if (IN6_IS_ADDR_MULTICAST(taddr6))
363 return;
364
365 /* estimate the size of message */
366 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
367 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
368 #ifdef DIAGNOSTIC
369 if (max_linkhdr + maxlen >= MCLBYTES) {
370 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
371 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
372 panic("nd6_ns_output: insufficient MCLBYTES");
373 /* NOTREACHED */
374 }
375 #endif
376
377 MGETHDR(m, M_DONTWAIT, MT_DATA);
378 if (m && max_linkhdr + maxlen >= MHLEN) {
379 MCLGET(m, M_DONTWAIT);
380 if ((m->m_flags & M_EXT) == 0) {
381 m_free(m);
382 m = NULL;
383 }
384 }
385 if (m == NULL)
386 return;
387 m->m_pkthdr.rcvif = NULL;
388
389 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
390 m->m_flags |= M_MCAST;
391 im6o.im6o_multicast_ifp = ifp;
392 im6o.im6o_multicast_hlim = 255;
393 im6o.im6o_multicast_loop = 0;
394 }
395
396 icmp6len = sizeof(*nd_ns);
397 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
398 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
399
400 /* fill neighbor solicitation packet */
401 ip6 = mtod(m, struct ip6_hdr *);
402 ip6->ip6_flow = 0;
403 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
404 ip6->ip6_vfc |= IPV6_VERSION;
405 /* ip6->ip6_plen will be set later */
406 ip6->ip6_nxt = IPPROTO_ICMPV6;
407 ip6->ip6_hlim = 255;
408 /* determine the source and destination addresses */
409 bzero(&src_sa, sizeof(src_sa));
410 bzero(&dst_sa, sizeof(dst_sa));
411 src_sa.sin6_family = dst_sa.sin6_family = AF_INET6;
412 src_sa.sin6_len = dst_sa.sin6_len = sizeof(struct sockaddr_in6);
413 if (daddr6)
414 dst_sa.sin6_addr = *daddr6;
415 else {
416 dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
417 dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
418 dst_sa.sin6_addr.s6_addr32[1] = 0;
419 dst_sa.sin6_addr.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
420 dst_sa.sin6_addr.s6_addr32[3] = taddr6->s6_addr32[3];
421 dst_sa.sin6_addr.s6_addr8[12] = 0xff;
422 }
423 ip6->ip6_dst = dst_sa.sin6_addr;
424 if (!dad) {
425 /*
426 * RFC2461 7.2.2:
427 * "If the source address of the packet prompting the
428 * solicitation is the same as one of the addresses assigned
429 * to the outgoing interface, that address SHOULD be placed
430 * in the IP Source Address of the outgoing solicitation.
431 * Otherwise, any one of the addresses assigned to the
432 * interface should be used."
433 *
434 * We use the source address for the prompting packet
435 * (saddr6), if:
436 * - saddr6 is given from the caller (by giving "ln"), and
437 * - saddr6 belongs to the outgoing interface.
438 * Otherwise, we perform the source address selection as usual.
439 */
440 struct ip6_hdr *hip6; /* hold ip6 */
441 struct in6_addr *saddr6;
442
443 if (ln && ln->ln_hold) {
444 hip6 = mtod(ln->ln_hold, struct ip6_hdr *);
445 /* XXX pullup? */
446 if (sizeof(*hip6) < ln->ln_hold->m_len)
447 saddr6 = &hip6->ip6_src;
448 else
449 saddr6 = NULL;
450 } else
451 saddr6 = NULL;
452 if (saddr6 && in6ifa_ifpwithaddr(ifp, saddr6))
453 src_sa.sin6_addr = *saddr6;
454 else {
455 struct in6_addr *src0;
456 int error;
457
458 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
459 src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL,
460 &error);
461 if (src0 == NULL) {
462 nd6log((LOG_DEBUG,
463 "nd6_ns_output: source can't be "
464 "determined: dst=%s, error=%d\n",
465 ip6_sprintf(&dst_sa.sin6_addr), error));
466 goto bad;
467 }
468 src_sa.sin6_addr = *src0;
469 }
470 } else {
471 /*
472 * Source address for DAD packet must always be IPv6
473 * unspecified address. (0::0)
474 * We actually don't have to 0-clear the address (we did it
475 * above), but we do so here explicitly to make the intention
476 * clearer.
477 */
478 bzero(&src_sa.sin6_addr, sizeof(src_sa.sin6_addr));
479 }
480 ip6->ip6_src = src_sa.sin6_addr;
481 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
482 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
483 nd_ns->nd_ns_code = 0;
484 nd_ns->nd_ns_reserved = 0;
485 nd_ns->nd_ns_target = *taddr6;
486
487 if (IN6_IS_SCOPE_LINKLOCAL(&nd_ns->nd_ns_target))
488 nd_ns->nd_ns_target.s6_addr16[1] = 0;
489
490 /*
491 * Add source link-layer address option.
492 *
493 * spec implementation
494 * --- ---
495 * DAD packet MUST NOT do not add the option
496 * there's no link layer address:
497 * impossible do not add the option
498 * there's link layer address:
499 * Multicast NS MUST add one add the option
500 * Unicast NS SHOULD add one add the option
501 */
502 if (!dad && (mac = nd6_ifptomac(ifp))) {
503 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
504 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
505 /* 8 byte alignments... */
506 optlen = (optlen + 7) & ~7;
507
508 m->m_pkthdr.len += optlen;
509 m->m_len += optlen;
510 icmp6len += optlen;
511 bzero((caddr_t)nd_opt, optlen);
512 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
513 nd_opt->nd_opt_len = optlen >> 3;
514 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
515 }
516
517 ip6->ip6_plen = htons((u_short)icmp6len);
518 nd_ns->nd_ns_cksum = 0;
519 nd_ns->nd_ns_cksum =
520 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
521
522 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL);
523 icmp6_ifstat_inc(ifp, ifs6_out_msg);
524 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
525 icmp6stat.icp6s_outhist[ND_NEIGHBOR_SOLICIT]++;
526
527 if (ro.ro_rt) { /* we don't cache this route. */
528 RTFREE(ro.ro_rt);
529 }
530 return;
531
532 bad:
533 if (ro.ro_rt) {
534 RTFREE(ro.ro_rt);
535 }
536 m_freem(m);
537 return;
538 }
539
540 /*
541 * Neighbor advertisement input handling.
542 *
543 * Based on RFC 2461
544 * Based on RFC 2462 (duplicated address detection)
545 *
546 * the following items are not implemented yet:
547 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
548 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
549 */
550 void
nd6_na_input(m,off,icmp6len)551 nd6_na_input(m, off, icmp6len)
552 struct mbuf *m;
553 int off, icmp6len;
554 {
555 struct ifnet *ifp = m->m_pkthdr.rcvif;
556 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
557 struct nd_neighbor_advert *nd_na;
558 struct in6_addr saddr6 = ip6->ip6_src;
559 struct in6_addr daddr6 = ip6->ip6_dst;
560 struct in6_addr taddr6;
561 int flags;
562 int is_router;
563 int is_solicited;
564 int is_override;
565 char *lladdr = NULL;
566 int lladdrlen = 0;
567 struct ifaddr *ifa;
568 struct llinfo_nd6 *ln;
569 struct rtentry *rt;
570 struct sockaddr_dl *sdl;
571 union nd_opts ndopts;
572
573 if (ip6->ip6_hlim != 255) {
574 nd6log((LOG_ERR,
575 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
576 ip6->ip6_hlim, ip6_sprintf(&ip6->ip6_src),
577 ip6_sprintf(&ip6->ip6_dst), ifp->if_xname));
578 goto bad;
579 }
580
581 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
582 if (nd_na == NULL) {
583 icmp6stat.icp6s_tooshort++;
584 return;
585 }
586 taddr6 = nd_na->nd_na_target;
587 flags = nd_na->nd_na_flags_reserved;
588 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
589 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
590 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
591
592 if (IN6_IS_SCOPE_LINKLOCAL(&taddr6))
593 taddr6.s6_addr16[1] = htons(ifp->if_index);
594
595 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
596 nd6log((LOG_ERR,
597 "nd6_na_input: invalid target address %s\n",
598 ip6_sprintf(&taddr6)));
599 goto bad;
600 }
601 if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) {
602 nd6log((LOG_ERR,
603 "nd6_na_input: a solicited adv is multicasted\n"));
604 goto bad;
605 }
606
607 icmp6len -= sizeof(*nd_na);
608 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
609 if (nd6_options(&ndopts) < 0) {
610 nd6log((LOG_INFO,
611 "nd6_na_input: invalid ND option, ignored\n"));
612 /* nd6_options have incremented stats */
613 goto freeit;
614 }
615
616 if (ndopts.nd_opts_tgt_lladdr) {
617 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
618 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
619 }
620
621 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
622
623 /*
624 * Target address matches one of my interface address.
625 *
626 * If my address is tentative, this means that there's somebody
627 * already using the same address as mine. This indicates DAD failure.
628 * This is defined in RFC 2462.
629 *
630 * Otherwise, process as defined in RFC 2461.
631 */
632 if (ifa
633 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
634 nd6_dad_na_input(ifa);
635 goto freeit;
636 }
637
638 /* Just for safety, maybe unnecessary. */
639 if (ifa) {
640 log(LOG_ERR,
641 "nd6_na_input: duplicate IP6 address %s\n",
642 ip6_sprintf(&taddr6));
643 goto freeit;
644 }
645 /*
646 * Make sure the source address is from a neighbor's address.
647 */
648 if (in6ifa_ifplocaladdr(ifp, &saddr6) == NULL) {
649 nd6log((LOG_INFO, "nd6_na_input: "
650 "ND packet from non-neighbor\n"));
651 goto bad;
652 }
653
654 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
655 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
656 "(if %d, NA packet %d)\n", ip6_sprintf(&taddr6),
657 ifp->if_addrlen, lladdrlen - 2));
658 goto bad;
659 }
660
661 /*
662 * If no neighbor cache entry is found, NA SHOULD silently be
663 * discarded.
664 */
665 rt = nd6_lookup(&taddr6, 0, ifp);
666 if ((rt == NULL) ||
667 ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) ||
668 ((sdl = SDL(rt->rt_gateway)) == NULL))
669 goto freeit;
670
671 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
672 /*
673 * If the link-layer has address, and no lladdr option came,
674 * discard the packet.
675 */
676 if (ifp->if_addrlen && !lladdr)
677 goto freeit;
678
679 /*
680 * Record link-layer address, and update the state.
681 */
682 sdl->sdl_alen = ifp->if_addrlen;
683 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
684 if (is_solicited) {
685 ln->ln_state = ND6_LLINFO_REACHABLE;
686 ln->ln_byhint = 0;
687 if (!ND6_LLINFO_PERMANENT(ln)) {
688 nd6_llinfo_settimer(ln,
689 (long)ND_IFINFO(rt->rt_ifp)->reachable * hz);
690 }
691 } else {
692 ln->ln_state = ND6_LLINFO_STALE;
693 nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
694 }
695 if ((ln->ln_router = is_router) != 0) {
696 /*
697 * This means a router's state has changed from
698 * non-reachable to probably reachable, and might
699 * affect the status of associated prefixes..
700 */
701 pfxlist_onlink_check();
702 }
703 } else {
704 int llchange;
705
706 /*
707 * Check if the link-layer address has changed or not.
708 */
709 if (!lladdr)
710 llchange = 0;
711 else {
712 if (sdl->sdl_alen) {
713 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
714 llchange = 1;
715 else
716 llchange = 0;
717 } else
718 llchange = 1;
719 }
720
721 /*
722 * This is VERY complex. Look at it with care.
723 *
724 * override solicit lladdr llchange action
725 * (L: record lladdr)
726 *
727 * 0 0 n -- (2c)
728 * 0 0 y n (2b) L
729 * 0 0 y y (1) REACHABLE->STALE
730 * 0 1 n -- (2c) *->REACHABLE
731 * 0 1 y n (2b) L *->REACHABLE
732 * 0 1 y y (1) REACHABLE->STALE
733 * 1 0 n -- (2a)
734 * 1 0 y n (2a) L
735 * 1 0 y y (2a) L *->STALE
736 * 1 1 n -- (2a) *->REACHABLE
737 * 1 1 y n (2a) L *->REACHABLE
738 * 1 1 y y (2a) L *->REACHABLE
739 */
740 if (!is_override && (lladdr && llchange)) { /* (1) */
741 /*
742 * If state is REACHABLE, make it STALE.
743 * no other updates should be done.
744 */
745 if (ln->ln_state == ND6_LLINFO_REACHABLE) {
746 ln->ln_state = ND6_LLINFO_STALE;
747 nd6_llinfo_settimer(ln, (long)nd6_gctimer * hz);
748 }
749 goto freeit;
750 } else if (is_override /* (2a) */
751 || (!is_override && (lladdr && !llchange)) /* (2b) */
752 || !lladdr) { /* (2c) */
753 /*
754 * Update link-local address, if any.
755 */
756 if (lladdr) {
757 sdl->sdl_alen = ifp->if_addrlen;
758 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
759 }
760
761 /*
762 * If solicited, make the state REACHABLE.
763 * If not solicited and the link-layer address was
764 * changed, make it STALE.
765 */
766 if (is_solicited) {
767 ln->ln_state = ND6_LLINFO_REACHABLE;
768 ln->ln_byhint = 0;
769 if (!ND6_LLINFO_PERMANENT(ln)) {
770 nd6_llinfo_settimer(ln,
771 (long)ND_IFINFO(ifp)->reachable * hz);
772 }
773 } else {
774 if (lladdr && llchange) {
775 ln->ln_state = ND6_LLINFO_STALE;
776 nd6_llinfo_settimer(ln,
777 (long)nd6_gctimer * hz);
778 }
779 }
780 }
781
782 if (ln->ln_router && !is_router) {
783 /*
784 * The peer dropped the router flag.
785 * Remove the sender from the Default Router List and
786 * update the Destination Cache entries.
787 */
788 struct nd_defrouter *dr;
789 struct in6_addr *in6;
790 int s;
791
792 in6 = &((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
793
794 /*
795 * Lock to protect the default router list.
796 * XXX: this might be unnecessary, since this function
797 * is only called under the network software interrupt
798 * context. However, we keep it just for safety.
799 */
800 s = splsoftnet();
801 dr = defrouter_lookup(in6, rt->rt_ifp);
802 if (dr)
803 defrtrlist_del(dr);
804 else if (!ip6_forwarding) {
805 /*
806 * Even if the neighbor is not in the default
807 * router list, the neighbor may be used
808 * as a next hop for some destinations
809 * (e.g. redirect case). So we must
810 * call rt6_flush explicitly.
811 */
812 rt6_flush(&ip6->ip6_src, rt->rt_ifp);
813 }
814 splx(s);
815 }
816 ln->ln_router = is_router;
817 }
818 rt->rt_flags &= ~RTF_REJECT;
819 ln->ln_asked = 0;
820 if (ln->ln_hold) {
821 /*
822 * we assume ifp is not a loopback here, so just set the 2nd
823 * argument as the 1st one.
824 */
825 nd6_output(ifp, ifp, ln->ln_hold,
826 (struct sockaddr_in6 *)rt_key(rt), rt);
827 ln->ln_hold = NULL;
828 }
829
830 freeit:
831 m_freem(m);
832 return;
833
834 bad:
835 icmp6stat.icp6s_badna++;
836 m_freem(m);
837 }
838
839 /*
840 * Neighbor advertisement output handling.
841 *
842 * Based on RFC 2461
843 *
844 * the following items are not implemented yet:
845 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
846 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
847 */
848 void
nd6_na_output(ifp,daddr6,taddr6,flags,tlladdr,sdl0)849 nd6_na_output(ifp, daddr6, taddr6, flags, tlladdr, sdl0)
850 struct ifnet *ifp;
851 struct in6_addr *daddr6, *taddr6;
852 u_long flags;
853 int tlladdr; /* 1 if include target link-layer address */
854 struct sockaddr *sdl0; /* sockaddr_dl (= proxy NA) or NULL */
855 {
856 struct mbuf *m;
857 struct ip6_hdr *ip6;
858 struct nd_neighbor_advert *nd_na;
859 struct ip6_moptions im6o;
860 struct sockaddr_in6 src_sa, dst_sa;
861 struct in6_addr *src0;
862 int icmp6len, maxlen, error;
863 caddr_t mac;
864 struct route_in6 ro;
865
866 mac = NULL;
867 bzero(&ro, sizeof(ro));
868
869 /* estimate the size of message */
870 maxlen = sizeof(*ip6) + sizeof(*nd_na);
871 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
872 #ifdef DIAGNOSTIC
873 if (max_linkhdr + maxlen >= MCLBYTES) {
874 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
875 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
876 panic("nd6_na_output: insufficient MCLBYTES");
877 /* NOTREACHED */
878 }
879 #endif
880
881 MGETHDR(m, M_DONTWAIT, MT_DATA);
882 if (m && max_linkhdr + maxlen >= MHLEN) {
883 MCLGET(m, M_DONTWAIT);
884 if ((m->m_flags & M_EXT) == 0) {
885 m_free(m);
886 m = NULL;
887 }
888 }
889 if (m == NULL)
890 return;
891 m->m_pkthdr.rcvif = NULL;
892
893 if (IN6_IS_ADDR_MULTICAST(daddr6)) {
894 m->m_flags |= M_MCAST;
895 im6o.im6o_multicast_ifp = ifp;
896 im6o.im6o_multicast_hlim = 255;
897 im6o.im6o_multicast_loop = 0;
898 }
899
900 icmp6len = sizeof(*nd_na);
901 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
902 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
903
904 /* fill neighbor advertisement packet */
905 ip6 = mtod(m, struct ip6_hdr *);
906 ip6->ip6_flow = 0;
907 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
908 ip6->ip6_vfc |= IPV6_VERSION;
909 ip6->ip6_nxt = IPPROTO_ICMPV6;
910 ip6->ip6_hlim = 255;
911 bzero(&src_sa, sizeof(src_sa));
912 bzero(&dst_sa, sizeof(dst_sa));
913 src_sa.sin6_len = dst_sa.sin6_len = sizeof(struct sockaddr_in6);
914 src_sa.sin6_family = dst_sa.sin6_family = AF_INET6;
915 dst_sa.sin6_addr = *daddr6;
916 if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) {
917 /* reply to DAD */
918 dst_sa.sin6_addr.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
919 dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
920 dst_sa.sin6_addr.s6_addr32[1] = 0;
921 dst_sa.sin6_addr.s6_addr32[2] = 0;
922 dst_sa.sin6_addr.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
923
924 flags &= ~ND_NA_FLAG_SOLICITED;
925 }
926 ip6->ip6_dst = dst_sa.sin6_addr;
927
928 /*
929 * Select a source whose scope is the same as that of the dest.
930 */
931 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
932 src0 = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &error);
933 if (src0 == NULL) {
934 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
935 "determined: dst=%s, error=%d\n",
936 ip6_sprintf(&dst_sa.sin6_addr), error));
937 goto bad;
938 }
939 src_sa.sin6_addr = *src0;
940 ip6->ip6_src = src_sa.sin6_addr;
941 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
942 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
943 nd_na->nd_na_code = 0;
944 nd_na->nd_na_target = *taddr6;
945 if (IN6_IS_SCOPE_LINKLOCAL(&nd_na->nd_na_target))
946 nd_na->nd_na_target.s6_addr16[1] = 0;
947
948 /*
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.
953 */
954 if (tlladdr) {
955 /*
956 * sdl0 != NULL indicates proxy NA. If we do proxy, use
957 * lladdr in sdl0. If we are not proxying (sending NA for
958 * my address) use lladdr configured for the interface.
959 */
960 if (sdl0 == NULL) {
961 mac = nd6_ifptomac(ifp);
962 } else if (sdl0->sa_family == AF_LINK) {
963 struct sockaddr_dl *sdl;
964 sdl = (struct sockaddr_dl *)sdl0;
965 if (sdl->sdl_alen == ifp->if_addrlen)
966 mac = LLADDR(sdl);
967 }
968 }
969 if (tlladdr && mac) {
970 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
971 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
972
973 /* roundup to 8 bytes alignment! */
974 optlen = (optlen + 7) & ~7;
975
976 m->m_pkthdr.len += optlen;
977 m->m_len += optlen;
978 icmp6len += optlen;
979 bzero((caddr_t)nd_opt, optlen);
980 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
981 nd_opt->nd_opt_len = optlen >> 3;
982 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
983 } else
984 flags &= ~ND_NA_FLAG_OVERRIDE;
985
986 ip6->ip6_plen = htons((u_short)icmp6len);
987 nd_na->nd_na_flags_reserved = flags;
988 nd_na->nd_na_cksum = 0;
989 nd_na->nd_na_cksum =
990 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
991
992 ip6_output(m, NULL, &ro, 0, &im6o, NULL);
993
994 icmp6_ifstat_inc(ifp, ifs6_out_msg);
995 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
996 icmp6stat.icp6s_outhist[ND_NEIGHBOR_ADVERT]++;
997
998 if (ro.ro_rt) { /* we don't cache this route. */
999 RTFREE(ro.ro_rt);
1000 }
1001 return;
1002
1003 bad:
1004 if (ro.ro_rt) {
1005 RTFREE(ro.ro_rt);
1006 }
1007 m_freem(m);
1008 return;
1009 }
1010
1011 caddr_t
nd6_ifptomac(ifp)1012 nd6_ifptomac(ifp)
1013 struct ifnet *ifp;
1014 {
1015 switch (ifp->if_type) {
1016 case IFT_ARCNET:
1017 case IFT_ETHER:
1018 case IFT_FDDI:
1019 case IFT_IEEE1394:
1020 case IFT_PROPVIRTUAL:
1021 #ifdef IFT_CARP
1022 case IFT_CARP:
1023 #endif
1024 case IFT_L2VLAN:
1025 case IFT_IEEE80211:
1026 return ((caddr_t)(ifp + 1));
1027 default:
1028 return NULL;
1029 }
1030 }
1031
1032 TAILQ_HEAD(dadq_head, dadq);
1033 struct dadq {
1034 TAILQ_ENTRY(dadq) dad_list;
1035 struct ifaddr *dad_ifa;
1036 int dad_count; /* max NS to send */
1037 int dad_ns_tcount; /* # of trials to send NS */
1038 int dad_ns_ocount; /* NS sent so far */
1039 int dad_ns_icount;
1040 int dad_na_icount;
1041 struct timeout dad_timer_ch;
1042 };
1043
1044 static struct dadq_head dadq;
1045 static int dad_init = 0;
1046
1047 static struct dadq *
nd6_dad_find(ifa)1048 nd6_dad_find(ifa)
1049 struct ifaddr *ifa;
1050 {
1051 struct dadq *dp;
1052
1053 for (dp = dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
1054 if (dp->dad_ifa == ifa)
1055 return dp;
1056 }
1057 return NULL;
1058 }
1059
1060 static void
nd6_dad_starttimer(dp,ticks)1061 nd6_dad_starttimer(dp, ticks)
1062 struct dadq *dp;
1063 int ticks;
1064 {
1065
1066 timeout_set(&dp->dad_timer_ch, (void (*)(void *))nd6_dad_timer,
1067 (void *)dp->dad_ifa);
1068 timeout_add(&dp->dad_timer_ch, ticks);
1069 }
1070
1071 static void
nd6_dad_stoptimer(dp)1072 nd6_dad_stoptimer(dp)
1073 struct dadq *dp;
1074 {
1075
1076 timeout_del(&dp->dad_timer_ch);
1077 }
1078
1079 /*
1080 * Start Duplicated Address Detection (DAD) for specified interface address.
1081 */
1082 void
nd6_dad_start(ifa,tick)1083 nd6_dad_start(ifa, tick)
1084 struct ifaddr *ifa;
1085 int *tick; /* minimum delay ticks for IFF_UP event */
1086 {
1087 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1088 struct dadq *dp;
1089
1090 if (!dad_init) {
1091 TAILQ_INIT(&dadq);
1092 dad_init++;
1093 }
1094
1095 /*
1096 * If we don't need DAD, don't do it.
1097 * There are several cases:
1098 * - DAD is disabled (ip6_dad_count == 0)
1099 * - the interface address is anycast
1100 */
1101 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1102 log(LOG_DEBUG,
1103 "nd6_dad_start: called with non-tentative address "
1104 "%s(%s)\n",
1105 ip6_sprintf(&ia->ia_addr.sin6_addr),
1106 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???");
1107 return;
1108 }
1109 if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1110 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1111 return;
1112 }
1113 if (!ip6_dad_count) {
1114 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1115 return;
1116 }
1117 if (!ifa->ifa_ifp)
1118 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1119 if (!(ifa->ifa_ifp->if_flags & IFF_UP))
1120 return;
1121 if (nd6_dad_find(ifa) != NULL) {
1122 /* DAD already in progress */
1123 return;
1124 }
1125
1126 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
1127 if (dp == NULL) {
1128 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1129 "%s(%s)\n",
1130 ip6_sprintf(&ia->ia_addr.sin6_addr),
1131 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???");
1132 return;
1133 }
1134 bzero(dp, sizeof(*dp));
1135 bzero(&dp->dad_timer_ch, sizeof(dp->dad_timer_ch));
1136 TAILQ_INSERT_TAIL(&dadq, (struct dadq *)dp, dad_list);
1137
1138 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", ifa->ifa_ifp->if_xname,
1139 ip6_sprintf(&ia->ia_addr.sin6_addr)));
1140
1141 /*
1142 * Send NS packet for DAD, ip6_dad_count times.
1143 * Note that we must delay the first transmission, if this is the
1144 * first packet to be sent from the interface after interface
1145 * (re)initialization.
1146 */
1147 dp->dad_ifa = ifa;
1148 ifa->ifa_refcnt++; /* just for safety */
1149 dp->dad_count = ip6_dad_count;
1150 dp->dad_ns_icount = dp->dad_na_icount = 0;
1151 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1152 if (tick == NULL) {
1153 nd6_dad_ns_output(dp, ifa);
1154 nd6_dad_starttimer(dp,
1155 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1156 } else {
1157 int ntick;
1158
1159 if (*tick == 0)
1160 ntick = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * hz);
1161 else
1162 ntick = *tick + arc4random_uniform(hz / 2);
1163 *tick = ntick;
1164 nd6_dad_starttimer(dp, ntick);
1165 }
1166 }
1167
1168 /*
1169 * terminate DAD unconditionally. used for address removals.
1170 */
1171 void
nd6_dad_stop(ifa)1172 nd6_dad_stop(ifa)
1173 struct ifaddr *ifa;
1174 {
1175 struct dadq *dp;
1176
1177 if (!dad_init)
1178 return;
1179 dp = nd6_dad_find(ifa);
1180 if (!dp) {
1181 /* DAD wasn't started yet */
1182 return;
1183 }
1184
1185 nd6_dad_stoptimer(dp);
1186
1187 TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1188 free(dp, M_IP6NDP);
1189 dp = NULL;
1190 IFAFREE(ifa);
1191 }
1192
1193 static void
nd6_dad_timer(ifa)1194 nd6_dad_timer(ifa)
1195 struct ifaddr *ifa;
1196 {
1197 int s;
1198 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1199 struct dadq *dp;
1200
1201 s = splsoftnet(); /* XXX */
1202
1203 /* Sanity check */
1204 if (ia == NULL) {
1205 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1206 goto done;
1207 }
1208 dp = nd6_dad_find(ifa);
1209 if (dp == NULL) {
1210 log(LOG_ERR, "nd6_dad_timer: DAD structure not found\n");
1211 goto done;
1212 }
1213 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1214 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1215 "%s(%s)\n",
1216 ip6_sprintf(&ia->ia_addr.sin6_addr),
1217 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???");
1218 goto done;
1219 }
1220 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1221 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1222 "%s(%s)\n",
1223 ip6_sprintf(&ia->ia_addr.sin6_addr),
1224 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???");
1225 goto done;
1226 }
1227
1228 /* timeouted with IFF_{RUNNING,UP} check */
1229 if (dp->dad_ns_tcount > dad_maxtry) {
1230 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
1231 ifa->ifa_ifp->if_xname));
1232
1233 TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1234 free(dp, M_IP6NDP);
1235 dp = NULL;
1236 IFAFREE(ifa);
1237 goto done;
1238 }
1239
1240 /* Need more checks? */
1241 if (dp->dad_ns_ocount < dp->dad_count) {
1242 /*
1243 * We have more NS to go. Send NS packet for DAD.
1244 */
1245 nd6_dad_ns_output(dp, ifa);
1246 nd6_dad_starttimer(dp,
1247 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1248 } else {
1249 /*
1250 * We have transmitted sufficient number of DAD packets.
1251 * See what we've got.
1252 */
1253 int duplicate;
1254
1255 duplicate = 0;
1256
1257 if (dp->dad_na_icount) {
1258 /*
1259 * the check is in nd6_dad_na_input(),
1260 * but just in case
1261 */
1262 duplicate++;
1263 }
1264
1265 if (dp->dad_ns_icount) {
1266 /* We've seen NS, means DAD has failed. */
1267 duplicate++;
1268 }
1269
1270 if (duplicate) {
1271 /* (*dp) will be freed in nd6_dad_duplicated() */
1272 dp = NULL;
1273 nd6_dad_duplicated(ifa);
1274 } else {
1275 /*
1276 * We are done with DAD. No NA came, no NS came.
1277 * duplicated address found.
1278 */
1279 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1280
1281 nd6log((LOG_DEBUG,
1282 "%s: DAD complete for %s - no duplicates found\n",
1283 ifa->ifa_ifp->if_xname,
1284 ip6_sprintf(&ia->ia_addr.sin6_addr)));
1285
1286 TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1287 free(dp, M_IP6NDP);
1288 dp = NULL;
1289 IFAFREE(ifa);
1290 }
1291 }
1292
1293 done:
1294 splx(s);
1295 }
1296
1297 void
nd6_dad_duplicated(ifa)1298 nd6_dad_duplicated(ifa)
1299 struct ifaddr *ifa;
1300 {
1301 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1302 struct dadq *dp;
1303
1304 dp = nd6_dad_find(ifa);
1305 if (dp == NULL) {
1306 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
1307 return;
1308 }
1309
1310 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1311 "NS in/out=%d/%d, NA in=%d\n",
1312 ifa->ifa_ifp->if_xname, ip6_sprintf(&ia->ia_addr.sin6_addr),
1313 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
1314
1315 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1316 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1317
1318 /* We are done with DAD, with duplicated address found. (failure) */
1319 nd6_dad_stoptimer(dp);
1320
1321 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1322 ifa->ifa_ifp->if_xname, ip6_sprintf(&ia->ia_addr.sin6_addr));
1323 log(LOG_ERR, "%s: manual intervention required\n",
1324 ifa->ifa_ifp->if_xname);
1325
1326 TAILQ_REMOVE(&dadq, (struct dadq *)dp, dad_list);
1327 free(dp, M_IP6NDP);
1328 dp = NULL;
1329 IFAFREE(ifa);
1330 }
1331
1332 static void
nd6_dad_ns_output(dp,ifa)1333 nd6_dad_ns_output(dp, ifa)
1334 struct dadq *dp;
1335 struct ifaddr *ifa;
1336 {
1337 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1338 struct ifnet *ifp = ifa->ifa_ifp;
1339
1340 dp->dad_ns_tcount++;
1341 if ((ifp->if_flags & IFF_UP) == 0) {
1342 #if 0
1343 printf("%s: interface down?\n", ifp->if_xname);
1344 #endif
1345 return;
1346 }
1347 if ((ifp->if_flags & IFF_RUNNING) == 0) {
1348 #if 0
1349 printf("%s: interface not running?\n", ifp->if_xname);
1350 #endif
1351 return;
1352 }
1353
1354 dp->dad_ns_ocount++;
1355 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
1356 }
1357
1358 static void
nd6_dad_ns_input(ifa)1359 nd6_dad_ns_input(ifa)
1360 struct ifaddr *ifa;
1361 {
1362 struct in6_ifaddr *ia;
1363 struct ifnet *ifp;
1364 struct in6_addr *taddr6;
1365 struct dadq *dp;
1366 int duplicate;
1367
1368 if (!ifa)
1369 panic("ifa == NULL in nd6_dad_ns_input");
1370
1371 ia = (struct in6_ifaddr *)ifa;
1372 ifp = ifa->ifa_ifp;
1373 taddr6 = &ia->ia_addr.sin6_addr;
1374 duplicate = 0;
1375 dp = nd6_dad_find(ifa);
1376
1377 /* Quickhack - completely ignore DAD NS packets */
1378 if (dad_ignore_ns) {
1379 nd6log((LOG_INFO,
1380 "nd6_dad_ns_input: ignoring DAD NS packet for "
1381 "address %s(%s)\n", ip6_sprintf(taddr6),
1382 ifa->ifa_ifp->if_xname));
1383 return;
1384 }
1385
1386 /*
1387 * if I'm yet to start DAD, someone else started using this address
1388 * first. I have a duplicate and you win.
1389 */
1390 if (!dp || dp->dad_ns_ocount == 0)
1391 duplicate++;
1392
1393 /* XXX more checks for loopback situation - see nd6_dad_timer too */
1394
1395 if (duplicate) {
1396 dp = NULL; /* will be freed in nd6_dad_duplicated() */
1397 nd6_dad_duplicated(ifa);
1398 } else {
1399 /*
1400 * not sure if I got a duplicate.
1401 * increment ns count and see what happens.
1402 */
1403 if (dp)
1404 dp->dad_ns_icount++;
1405 }
1406 }
1407
1408 static void
nd6_dad_na_input(ifa)1409 nd6_dad_na_input(ifa)
1410 struct ifaddr *ifa;
1411 {
1412 struct dadq *dp;
1413
1414 if (!ifa)
1415 panic("ifa == NULL in nd6_dad_na_input");
1416
1417 dp = nd6_dad_find(ifa);
1418 if (dp)
1419 dp->dad_na_icount++;
1420
1421 /* remove the address. */
1422 nd6_dad_duplicated(ifa);
1423 }
1424