1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: releng/9.0/sys/netinet6/nd6_nbr.c 222728 2011-06-06 02:14:23Z hrs $");
34
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 #include "opt_ipsec.h"
38 #include "opt_mpath.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/lock.h>
44 #include <sys/rwlock.h>
45 #include <sys/mbuf.h>
46 #include <sys/socket.h>
47 #include <sys/sockio.h>
48 #include <sys/time.h>
49 #include <sys/kernel.h>
50 #include <sys/errno.h>
51 #include <sys/syslog.h>
52 #include <sys/queue.h>
53 #include <sys/callout.h>
54
55 #include <net/if.h>
56 #include <net/if_types.h>
57 #include <net/if_dl.h>
58 #include <net/if_var.h>
59 #include <net/route.h>
60 #ifdef RADIX_MPATH
61 #include <net/radix_mpath.h>
62 #endif
63
64 #include <netinet/in.h>
65 #include <netinet/in_var.h>
66 #include <net/if_llatbl.h>
67 #define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le))
68 #include <netinet6/in6_var.h>
69 #include <netinet6/in6_ifattach.h>
70 #include <netinet/ip6.h>
71 #include <netinet6/ip6_var.h>
72 #include <netinet6/scope6_var.h>
73 #include <netinet6/nd6.h>
74 #include <netinet/icmp6.h>
75 #include <netinet/ip_carp.h>
76 #include <netinet6/send.h>
77
78 #define SDL(s) ((struct sockaddr_dl *)s)
79
80 struct dadq;
81 static struct dadq *nd6_dad_find(struct ifaddr *);
82 static void nd6_dad_starttimer(struct dadq *, int);
83 static void nd6_dad_stoptimer(struct dadq *);
84 static void nd6_dad_timer(struct dadq *);
85 static void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
86 static void nd6_dad_ns_input(struct ifaddr *);
87 static void nd6_dad_na_input(struct ifaddr *);
88
89 VNET_DEFINE(int, dad_ignore_ns) = 0; /* ignore NS in DAD - specwise incorrect*/
90 VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to transmit DAD packet */
91 #define V_dad_ignore_ns VNET(dad_ignore_ns)
92 #define V_dad_maxtry VNET(dad_maxtry)
93
94 /*
95 * Input a Neighbor Solicitation Message.
96 *
97 * Based on RFC 2461
98 * Based on RFC 2462 (duplicate address detection)
99 */
100 void
101 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
102 {
103 struct ifnet *ifp = m->m_pkthdr.rcvif;
104 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
105 struct nd_neighbor_solicit *nd_ns;
106 struct in6_addr saddr6 = ip6->ip6_src;
107 struct in6_addr daddr6 = ip6->ip6_dst;
108 struct in6_addr taddr6;
109 struct in6_addr myaddr6;
110 char *lladdr = NULL;
111 struct ifaddr *ifa = NULL;
112 int lladdrlen = 0;
113 int anycast = 0, proxy = 0, tentative = 0;
114 int tlladdr;
115 int rflag;
116 union nd_opts ndopts;
117 struct sockaddr_dl proxydl;
118 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
119
120 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
121 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
122 rflag = 0;
123 #ifndef PULLDOWN_TEST
124 IP6_EXTHDR_CHECK(m, off, icmp6len,);
125 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
126 #else
127 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
128 if (nd_ns == NULL) {
129 ICMP6STAT_INC(icp6s_tooshort);
130 return;
131 }
132 #endif
133 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
134 taddr6 = nd_ns->nd_ns_target;
135 if (in6_setscope(&taddr6, ifp, NULL) != 0)
136 goto bad;
137
138 if (ip6->ip6_hlim != 255) {
139 nd6log((LOG_ERR,
140 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
141 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
142 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
143 goto bad;
144 }
145
146 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
147 /* dst has to be a solicited node multicast address. */
148 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
149 /* don't check ifindex portion */
150 daddr6.s6_addr32[1] == 0 &&
151 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
152 daddr6.s6_addr8[12] == 0xff) {
153 ; /* good */
154 } else {
155 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
156 "(wrong ip6 dst)\n"));
157 goto bad;
158 }
159 } else if (!V_nd6_onlink_ns_rfc4861) {
160 struct sockaddr_in6 src_sa6;
161
162 /*
163 * According to recent IETF discussions, it is not a good idea
164 * to accept a NS from an address which would not be deemed
165 * to be a neighbor otherwise. This point is expected to be
166 * clarified in future revisions of the specification.
167 */
168 bzero(&src_sa6, sizeof(src_sa6));
169 src_sa6.sin6_family = AF_INET6;
170 src_sa6.sin6_len = sizeof(src_sa6);
171 src_sa6.sin6_addr = saddr6;
172 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
173 nd6log((LOG_INFO, "nd6_ns_input: "
174 "NS packet from non-neighbor\n"));
175 goto bad;
176 }
177 }
178
179 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
180 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
181 goto bad;
182 }
183
184 icmp6len -= sizeof(*nd_ns);
185 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
186 if (nd6_options(&ndopts) < 0) {
187 nd6log((LOG_INFO,
188 "nd6_ns_input: invalid ND option, ignored\n"));
189 /* nd6_options have incremented stats */
190 goto freeit;
191 }
192
193 if (ndopts.nd_opts_src_lladdr) {
194 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
195 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
196 }
197
198 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
199 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
200 "(link-layer address option)\n"));
201 goto bad;
202 }
203
204 /*
205 * Attaching target link-layer address to the NA?
206 * (RFC 2461 7.2.4)
207 *
208 * NS IP dst is unicast/anycast MUST NOT add
209 * NS IP dst is solicited-node multicast MUST add
210 *
211 * In implementation, we add target link-layer address by default.
212 * We do not add one in MUST NOT cases.
213 */
214 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
215 tlladdr = 0;
216 else
217 tlladdr = 1;
218
219 /*
220 * Target address (taddr6) must be either:
221 * (1) Valid unicast/anycast address for my receiving interface,
222 * (2) Unicast address for which I'm offering proxy service, or
223 * (3) "tentative" address on which DAD is being performed.
224 */
225 /* (1) and (3) check. */
226 if (ifp->if_carp)
227 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
228 if (ifa == NULL)
229 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
230
231 /* (2) check. */
232 if (ifa == NULL) {
233 struct rtentry *rt;
234 struct sockaddr_in6 tsin6;
235 int need_proxy;
236 #ifdef RADIX_MPATH
237 struct route_in6 ro;
238 #endif
239
240 bzero(&tsin6, sizeof tsin6);
241 tsin6.sin6_len = sizeof(struct sockaddr_in6);
242 tsin6.sin6_family = AF_INET6;
243 tsin6.sin6_addr = taddr6;
244
245 #ifdef RADIX_MPATH
246 bzero(&ro, sizeof(ro));
247 ro.ro_dst = tsin6;
248 rtalloc_mpath((struct route *)&ro, RTF_ANNOUNCE);
249 rt = ro.ro_rt;
250 #else
251 rt = rtalloc1((struct sockaddr *)&tsin6, 0, 0);
252 #endif
253 need_proxy = (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
254 rt->rt_gateway->sa_family == AF_LINK);
255 if (rt != NULL) {
256 /*
257 * Make a copy while we can be sure that rt_gateway
258 * is still stable before unlocking to avoid lock
259 * order problems. proxydl will only be used if
260 * proxy will be set in the next block.
261 */
262 if (need_proxy)
263 proxydl = *SDL(rt->rt_gateway);
264 RTFREE_LOCKED(rt);
265 }
266 if (need_proxy) {
267 /*
268 * proxy NDP for single entry
269 */
270 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
271 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
272 if (ifa)
273 proxy = 1;
274 }
275 }
276 if (ifa == NULL) {
277 /*
278 * We've got an NS packet, and we don't have that adddress
279 * assigned for us. We MUST silently ignore it.
280 * See RFC2461 7.2.3.
281 */
282 goto freeit;
283 }
284 myaddr6 = *IFA_IN6(ifa);
285 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
286 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
287 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
288 goto freeit;
289
290 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
291 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
292 "(if %d, NS packet %d)\n",
293 ip6_sprintf(ip6bufs, &taddr6),
294 ifp->if_addrlen, lladdrlen - 2));
295 goto bad;
296 }
297
298 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
299 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
300 ip6_sprintf(ip6bufs, &saddr6)));
301 goto freeit;
302 }
303
304 /*
305 * We have neighbor solicitation packet, with target address equals to
306 * one of my tentative address.
307 *
308 * src addr how to process?
309 * --- ---
310 * multicast of course, invalid (rejected in ip6_input)
311 * unicast somebody is doing address resolution -> ignore
312 * unspec dup address detection
313 *
314 * The processing is defined in RFC 2462.
315 */
316 if (tentative) {
317 /*
318 * If source address is unspecified address, it is for
319 * duplicate address detection.
320 *
321 * If not, the packet is for addess resolution;
322 * silently ignore it.
323 */
324 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
325 nd6_dad_ns_input(ifa);
326
327 goto freeit;
328 }
329
330 /*
331 * If the source address is unspecified address, entries must not
332 * be created or updated.
333 * It looks that sender is performing DAD. Output NA toward
334 * all-node multicast address, to tell the sender that I'm using
335 * the address.
336 * S bit ("solicited") must be zero.
337 */
338 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
339 struct in6_addr in6_all;
340
341 in6_all = in6addr_linklocal_allnodes;
342 if (in6_setscope(&in6_all, ifp, NULL) != 0)
343 goto bad;
344 nd6_na_output(ifp, &in6_all, &taddr6,
345 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
346 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL);
347 goto freeit;
348 }
349
350 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
351 ND_NEIGHBOR_SOLICIT, 0);
352
353 nd6_na_output(ifp, &saddr6, &taddr6,
354 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
355 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
356 proxy ? (struct sockaddr *)&proxydl : NULL);
357 freeit:
358 if (ifa != NULL)
359 ifa_free(ifa);
360 m_freem(m);
361 return;
362
363 bad:
364 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
365 ip6_sprintf(ip6bufs, &saddr6)));
366 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
367 ip6_sprintf(ip6bufs, &daddr6)));
368 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
369 ip6_sprintf(ip6bufs, &taddr6)));
370 ICMP6STAT_INC(icp6s_badns);
371 if (ifa != NULL)
372 ifa_free(ifa);
373 m_freem(m);
374 }
375
376 /*
377 * Output a Neighbor Solicitation Message. Caller specifies:
378 * - ICMP6 header source IP6 address
379 * - ND6 header target IP6 address
380 * - ND6 header source datalink address
381 *
382 * Based on RFC 2461
383 * Based on RFC 2462 (duplicate address detection)
384 *
385 * ln - for source address determination
386 * dad - duplicate address detection
387 */
388 void
389 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
390 const struct in6_addr *taddr6, struct llentry *ln, int dad)
391 {
392 struct mbuf *m;
393 struct m_tag *mtag;
394 struct ip6_hdr *ip6;
395 struct nd_neighbor_solicit *nd_ns;
396 struct ip6_moptions im6o;
397 int icmp6len;
398 int maxlen;
399 caddr_t mac;
400 struct route_in6 ro;
401
402 if (IN6_IS_ADDR_MULTICAST(taddr6))
403 return;
404
405 /* estimate the size of message */
406 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
407 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
408 if (max_linkhdr + maxlen >= MCLBYTES) {
409 #ifdef DIAGNOSTIC
410 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
411 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
412 #endif
413 return;
414 }
415
416 MGETHDR(m, M_DONTWAIT, MT_DATA);
417 if (m && max_linkhdr + maxlen >= MHLEN) {
418 MCLGET(m, M_DONTWAIT);
419 if ((m->m_flags & M_EXT) == 0) {
420 m_free(m);
421 m = NULL;
422 }
423 }
424 if (m == NULL)
425 return;
426 m->m_pkthdr.rcvif = NULL;
427
428 bzero(&ro, sizeof(ro));
429
430 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
431 m->m_flags |= M_MCAST;
432 im6o.im6o_multicast_ifp = ifp;
433 im6o.im6o_multicast_hlim = 255;
434 im6o.im6o_multicast_loop = 0;
435 }
436
437 icmp6len = sizeof(*nd_ns);
438 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
439 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
440
441 /* fill neighbor solicitation packet */
442 ip6 = mtod(m, struct ip6_hdr *);
443 ip6->ip6_flow = 0;
444 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
445 ip6->ip6_vfc |= IPV6_VERSION;
446 /* ip6->ip6_plen will be set later */
447 ip6->ip6_nxt = IPPROTO_ICMPV6;
448 ip6->ip6_hlim = 255;
449 if (daddr6)
450 ip6->ip6_dst = *daddr6;
451 else {
452 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
453 ip6->ip6_dst.s6_addr16[1] = 0;
454 ip6->ip6_dst.s6_addr32[1] = 0;
455 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
456 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
457 ip6->ip6_dst.s6_addr8[12] = 0xff;
458 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
459 goto bad;
460 }
461 if (!dad) {
462 struct ifaddr *ifa;
463
464 /*
465 * RFC2461 7.2.2:
466 * "If the source address of the packet prompting the
467 * solicitation is the same as one of the addresses assigned
468 * to the outgoing interface, that address SHOULD be placed
469 * in the IP Source Address of the outgoing solicitation.
470 * Otherwise, any one of the addresses assigned to the
471 * interface should be used."
472 *
473 * We use the source address for the prompting packet
474 * (saddr6), if:
475 * - saddr6 is given from the caller (by giving "ln"), and
476 * - saddr6 belongs to the outgoing interface.
477 * Otherwise, we perform the source address selection as usual.
478 */
479 struct in6_addr *hsrc;
480
481 hsrc = NULL;
482 if (ln != NULL) {
483 LLE_RLOCK(ln);
484 if (ln->la_hold != NULL) {
485 struct ip6_hdr *hip6; /* hold ip6 */
486
487 /*
488 * assuming every packet in la_hold has the same IP
489 * header
490 */
491 hip6 = mtod(ln->la_hold, struct ip6_hdr *);
492 /* XXX pullup? */
493 if (sizeof(*hip6) < ln->la_hold->m_len) {
494 ip6->ip6_src = hip6->ip6_src;
495 hsrc = &hip6->ip6_src;
496 }
497 }
498 LLE_RUNLOCK(ln);
499 }
500 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
501 hsrc)) != NULL) {
502 /* ip6_src set already. */
503 ifa_free(ifa);
504 } else {
505 int error;
506 struct sockaddr_in6 dst_sa;
507 struct in6_addr src_in;
508
509 bzero(&dst_sa, sizeof(dst_sa));
510 dst_sa.sin6_family = AF_INET6;
511 dst_sa.sin6_len = sizeof(dst_sa);
512 dst_sa.sin6_addr = ip6->ip6_dst;
513
514 error = in6_selectsrc(&dst_sa, NULL,
515 NULL, &ro, NULL, NULL, &src_in);
516 if (error) {
517 char ip6buf[INET6_ADDRSTRLEN];
518 nd6log((LOG_DEBUG,
519 "nd6_ns_output: source can't be "
520 "determined: dst=%s, error=%d\n",
521 ip6_sprintf(ip6buf, &dst_sa.sin6_addr),
522 error));
523 goto bad;
524 }
525 ip6->ip6_src = src_in;
526 }
527 } else {
528 /*
529 * Source address for DAD packet must always be IPv6
530 * unspecified address. (0::0)
531 * We actually don't have to 0-clear the address (we did it
532 * above), but we do so here explicitly to make the intention
533 * clearer.
534 */
535 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
536 }
537 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
538 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
539 nd_ns->nd_ns_code = 0;
540 nd_ns->nd_ns_reserved = 0;
541 nd_ns->nd_ns_target = *taddr6;
542 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
543
544 /*
545 * Add source link-layer address option.
546 *
547 * spec implementation
548 * --- ---
549 * DAD packet MUST NOT do not add the option
550 * there's no link layer address:
551 * impossible do not add the option
552 * there's link layer address:
553 * Multicast NS MUST add one add the option
554 * Unicast NS SHOULD add one add the option
555 */
556 if (!dad && (mac = nd6_ifptomac(ifp))) {
557 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
558 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
559 /* 8 byte alignments... */
560 optlen = (optlen + 7) & ~7;
561
562 m->m_pkthdr.len += optlen;
563 m->m_len += optlen;
564 icmp6len += optlen;
565 bzero((caddr_t)nd_opt, optlen);
566 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
567 nd_opt->nd_opt_len = optlen >> 3;
568 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
569 }
570
571 ip6->ip6_plen = htons((u_short)icmp6len);
572 nd_ns->nd_ns_cksum = 0;
573 nd_ns->nd_ns_cksum =
574 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
575
576 if (send_sendso_input_hook != NULL) {
577 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
578 sizeof(unsigned short), M_NOWAIT);
579 if (mtag == NULL)
580 goto bad;
581 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
582 m_tag_prepend(m, mtag);
583 }
584
585 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
586 icmp6_ifstat_inc(ifp, ifs6_out_msg);
587 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
588 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
589
590 if (ro.ro_rt) { /* we don't cache this route. */
591 RTFREE(ro.ro_rt);
592 }
593 return;
594
595 bad:
596 if (ro.ro_rt) {
597 RTFREE(ro.ro_rt);
598 }
599 m_freem(m);
600 return;
601 }
602
603 /*
604 * Neighbor advertisement input handling.
605 *
606 * Based on RFC 2461
607 * Based on RFC 2462 (duplicate address detection)
608 *
609 * the following items are not implemented yet:
610 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
611 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
612 */
613 void
614 nd6_na_input(struct mbuf *m, int off, int icmp6len)
615 {
616 struct ifnet *ifp = m->m_pkthdr.rcvif;
617 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
618 struct nd_neighbor_advert *nd_na;
619 struct in6_addr daddr6 = ip6->ip6_dst;
620 struct in6_addr taddr6;
621 int flags;
622 int is_router;
623 int is_solicited;
624 int is_override;
625 char *lladdr = NULL;
626 int lladdrlen = 0;
627 int checklink = 0;
628 struct ifaddr *ifa;
629 struct llentry *ln = NULL;
630 union nd_opts ndopts;
631 struct mbuf *chain = NULL;
632 struct m_tag *mtag;
633 struct sockaddr_in6 sin6;
634 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
635
636 if (ip6->ip6_hlim != 255) {
637 nd6log((LOG_ERR,
638 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
639 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
640 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
641 goto bad;
642 }
643
644 #ifndef PULLDOWN_TEST
645 IP6_EXTHDR_CHECK(m, off, icmp6len,);
646 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
647 #else
648 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
649 if (nd_na == NULL) {
650 ICMP6STAT_INC(icp6s_tooshort);
651 return;
652 }
653 #endif
654
655 flags = nd_na->nd_na_flags_reserved;
656 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
657 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
658 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
659
660 taddr6 = nd_na->nd_na_target;
661 if (in6_setscope(&taddr6, ifp, NULL))
662 goto bad; /* XXX: impossible */
663
664 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
665 nd6log((LOG_ERR,
666 "nd6_na_input: invalid target address %s\n",
667 ip6_sprintf(ip6bufs, &taddr6)));
668 goto bad;
669 }
670 if (IN6_IS_ADDR_MULTICAST(&daddr6))
671 if (is_solicited) {
672 nd6log((LOG_ERR,
673 "nd6_na_input: a solicited adv is multicasted\n"));
674 goto bad;
675 }
676
677 icmp6len -= sizeof(*nd_na);
678 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
679 if (nd6_options(&ndopts) < 0) {
680 nd6log((LOG_INFO,
681 "nd6_na_input: invalid ND option, ignored\n"));
682 /* nd6_options have incremented stats */
683 goto freeit;
684 }
685
686 if (ndopts.nd_opts_tgt_lladdr) {
687 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
688 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
689 }
690
691 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
692
693 /*
694 * Target address matches one of my interface address.
695 *
696 * If my address is tentative, this means that there's somebody
697 * already using the same address as mine. This indicates DAD failure.
698 * This is defined in RFC 2462.
699 *
700 * Otherwise, process as defined in RFC 2461.
701 */
702 if (ifa
703 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
704 ifa_free(ifa);
705 nd6_dad_na_input(ifa);
706 goto freeit;
707 }
708
709 /* Just for safety, maybe unnecessary. */
710 if (ifa) {
711 ifa_free(ifa);
712 log(LOG_ERR,
713 "nd6_na_input: duplicate IP6 address %s\n",
714 ip6_sprintf(ip6bufs, &taddr6));
715 goto freeit;
716 }
717
718 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
719 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
720 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
721 ifp->if_addrlen, lladdrlen - 2));
722 goto bad;
723 }
724
725 /*
726 * If no neighbor cache entry is found, NA SHOULD silently be
727 * discarded.
728 */
729 IF_AFDATA_LOCK(ifp);
730 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
731 IF_AFDATA_UNLOCK(ifp);
732 if (ln == NULL) {
733 goto freeit;
734 }
735
736 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
737 /*
738 * If the link-layer has address, and no lladdr option came,
739 * discard the packet.
740 */
741 if (ifp->if_addrlen && lladdr == NULL) {
742 goto freeit;
743 }
744
745 /*
746 * Record link-layer address, and update the state.
747 */
748 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
749 ln->la_flags |= LLE_VALID;
750 if (is_solicited) {
751 ln->ln_state = ND6_LLINFO_REACHABLE;
752 ln->ln_byhint = 0;
753 if (!ND6_LLINFO_PERMANENT(ln)) {
754 nd6_llinfo_settimer_locked(ln,
755 (long)ND_IFINFO(ln->lle_tbl->llt_ifp)->reachable * hz);
756 }
757 } else {
758 ln->ln_state = ND6_LLINFO_STALE;
759 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
760 }
761 if ((ln->ln_router = is_router) != 0) {
762 /*
763 * This means a router's state has changed from
764 * non-reachable to probably reachable, and might
765 * affect the status of associated prefixes..
766 */
767 checklink = 1;
768 }
769 } else {
770 int llchange;
771
772 /*
773 * Check if the link-layer address has changed or not.
774 */
775 if (lladdr == NULL)
776 llchange = 0;
777 else {
778 if (ln->la_flags & LLE_VALID) {
779 if (bcmp(lladdr, &ln->ll_addr, ifp->if_addrlen))
780 llchange = 1;
781 else
782 llchange = 0;
783 } else
784 llchange = 1;
785 }
786
787 /*
788 * This is VERY complex. Look at it with care.
789 *
790 * override solicit lladdr llchange action
791 * (L: record lladdr)
792 *
793 * 0 0 n -- (2c)
794 * 0 0 y n (2b) L
795 * 0 0 y y (1) REACHABLE->STALE
796 * 0 1 n -- (2c) *->REACHABLE
797 * 0 1 y n (2b) L *->REACHABLE
798 * 0 1 y y (1) REACHABLE->STALE
799 * 1 0 n -- (2a)
800 * 1 0 y n (2a) L
801 * 1 0 y y (2a) L *->STALE
802 * 1 1 n -- (2a) *->REACHABLE
803 * 1 1 y n (2a) L *->REACHABLE
804 * 1 1 y y (2a) L *->REACHABLE
805 */
806 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
807 /*
808 * If state is REACHABLE, make it STALE.
809 * no other updates should be done.
810 */
811 if (ln->ln_state == ND6_LLINFO_REACHABLE) {
812 ln->ln_state = ND6_LLINFO_STALE;
813 nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
814 }
815 goto freeit;
816 } else if (is_override /* (2a) */
817 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
818 || lladdr == NULL) { /* (2c) */
819 /*
820 * Update link-local address, if any.
821 */
822 if (lladdr != NULL) {
823 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
824 ln->la_flags |= LLE_VALID;
825 }
826
827 /*
828 * If solicited, make the state REACHABLE.
829 * If not solicited and the link-layer address was
830 * changed, make it STALE.
831 */
832 if (is_solicited) {
833 ln->ln_state = ND6_LLINFO_REACHABLE;
834 ln->ln_byhint = 0;
835 if (!ND6_LLINFO_PERMANENT(ln)) {
836 nd6_llinfo_settimer_locked(ln,
837 (long)ND_IFINFO(ifp)->reachable * hz);
838 }
839 } else {
840 if (lladdr != NULL && llchange) {
841 ln->ln_state = ND6_LLINFO_STALE;
842 nd6_llinfo_settimer_locked(ln,
843 (long)V_nd6_gctimer * hz);
844 }
845 }
846 }
847
848 if (ln->ln_router && !is_router) {
849 /*
850 * The peer dropped the router flag.
851 * Remove the sender from the Default Router List and
852 * update the Destination Cache entries.
853 */
854 struct nd_defrouter *dr;
855 struct in6_addr *in6;
856
857 in6 = &L3_ADDR_SIN6(ln)->sin6_addr;
858
859 /*
860 * Lock to protect the default router list.
861 * XXX: this might be unnecessary, since this function
862 * is only called under the network software interrupt
863 * context. However, we keep it just for safety.
864 */
865 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp);
866 if (dr)
867 defrtrlist_del(dr);
868 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags &
869 ND6_IFF_ACCEPT_RTADV) {
870 /*
871 * Even if the neighbor is not in the default
872 * router list, the neighbor may be used
873 * as a next hop for some destinations
874 * (e.g. redirect case). So we must
875 * call rt6_flush explicitly.
876 */
877 rt6_flush(&ip6->ip6_src, ifp);
878 }
879 }
880 ln->ln_router = is_router;
881 }
882 /* XXX - QL
883 * Does this matter?
884 * rt->rt_flags &= ~RTF_REJECT;
885 */
886 ln->la_asked = 0;
887 if (ln->la_hold) {
888 struct mbuf *m_hold, *m_hold_next;
889
890 /*
891 * reset the la_hold in advance, to explicitly
892 * prevent a la_hold lookup in nd6_output()
893 * (wouldn't happen, though...)
894 */
895 for (m_hold = ln->la_hold, ln->la_hold = NULL;
896 m_hold; m_hold = m_hold_next) {
897 m_hold_next = m_hold->m_nextpkt;
898 m_hold->m_nextpkt = NULL;
899 /*
900 * we assume ifp is not a loopback here, so just set
901 * the 2nd argument as the 1st one.
902 */
903
904 if (send_sendso_input_hook != NULL) {
905 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
906 sizeof(unsigned short), M_NOWAIT);
907 if (mtag == NULL)
908 goto bad;
909 m_tag_prepend(m, mtag);
910 }
911
912 nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
913 }
914 }
915 freeit:
916 if (ln != NULL) {
917 if (chain)
918 memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
919 LLE_WUNLOCK(ln);
920
921 if (chain)
922 nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
923 }
924 if (checklink)
925 pfxlist_onlink_check();
926
927 m_freem(m);
928 return;
929
930 bad:
931 if (ln != NULL)
932 LLE_WUNLOCK(ln);
933
934 ICMP6STAT_INC(icp6s_badna);
935 m_freem(m);
936 }
937
938 /*
939 * Neighbor advertisement output handling.
940 *
941 * Based on RFC 2461
942 *
943 * the following items are not implemented yet:
944 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
945 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
946 *
947 * tlladdr - 1 if include target link-layer address
948 * sdl0 - sockaddr_dl (= proxy NA) or NULL
949 */
950 void
951 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
952 const struct in6_addr *taddr6, u_long flags, int tlladdr,
953 struct sockaddr *sdl0)
954 {
955 struct mbuf *m;
956 struct m_tag *mtag;
957 struct ip6_hdr *ip6;
958 struct nd_neighbor_advert *nd_na;
959 struct ip6_moptions im6o;
960 struct in6_addr src, daddr6;
961 struct sockaddr_in6 dst_sa;
962 int icmp6len, maxlen, error;
963 caddr_t mac = NULL;
964 struct route_in6 ro;
965
966 bzero(&ro, sizeof(ro));
967
968 daddr6 = *daddr6_0; /* make a local copy for modification */
969
970 /* estimate the size of message */
971 maxlen = sizeof(*ip6) + sizeof(*nd_na);
972 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
973 if (max_linkhdr + maxlen >= MCLBYTES) {
974 #ifdef DIAGNOSTIC
975 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
976 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
977 #endif
978 return;
979 }
980
981 MGETHDR(m, M_DONTWAIT, MT_DATA);
982 if (m && max_linkhdr + maxlen >= MHLEN) {
983 MCLGET(m, M_DONTWAIT);
984 if ((m->m_flags & M_EXT) == 0) {
985 m_free(m);
986 m = NULL;
987 }
988 }
989 if (m == NULL)
990 return;
991 m->m_pkthdr.rcvif = NULL;
992
993 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
994 m->m_flags |= M_MCAST;
995 im6o.im6o_multicast_ifp = ifp;
996 im6o.im6o_multicast_hlim = 255;
997 im6o.im6o_multicast_loop = 0;
998 }
999
1000 icmp6len = sizeof(*nd_na);
1001 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
1002 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
1003
1004 /* fill neighbor advertisement packet */
1005 ip6 = mtod(m, struct ip6_hdr *);
1006 ip6->ip6_flow = 0;
1007 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1008 ip6->ip6_vfc |= IPV6_VERSION;
1009 ip6->ip6_nxt = IPPROTO_ICMPV6;
1010 ip6->ip6_hlim = 255;
1011 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
1012 /* reply to DAD */
1013 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
1014 daddr6.s6_addr16[1] = 0;
1015 daddr6.s6_addr32[1] = 0;
1016 daddr6.s6_addr32[2] = 0;
1017 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
1018 if (in6_setscope(&daddr6, ifp, NULL))
1019 goto bad;
1020
1021 flags &= ~ND_NA_FLAG_SOLICITED;
1022 }
1023 ip6->ip6_dst = daddr6;
1024 bzero(&dst_sa, sizeof(struct sockaddr_in6));
1025 dst_sa.sin6_family = AF_INET6;
1026 dst_sa.sin6_len = sizeof(struct sockaddr_in6);
1027 dst_sa.sin6_addr = daddr6;
1028
1029 /*
1030 * Select a source whose scope is the same as that of the dest.
1031 */
1032 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
1033 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, NULL, &src);
1034 if (error) {
1035 char ip6buf[INET6_ADDRSTRLEN];
1036 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1037 "determined: dst=%s, error=%d\n",
1038 ip6_sprintf(ip6buf, &dst_sa.sin6_addr), error));
1039 goto bad;
1040 }
1041 ip6->ip6_src = src;
1042 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1043 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1044 nd_na->nd_na_code = 0;
1045 nd_na->nd_na_target = *taddr6;
1046 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1047
1048 /*
1049 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1050 * see nd6_ns_input() for details.
1051 * Basically, if NS packet is sent to unicast/anycast addr,
1052 * target lladdr option SHOULD NOT be included.
1053 */
1054 if (tlladdr) {
1055 /*
1056 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1057 * lladdr in sdl0. If we are not proxying (sending NA for
1058 * my address) use lladdr configured for the interface.
1059 */
1060 if (sdl0 == NULL) {
1061 if (ifp->if_carp)
1062 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1063 if (mac == NULL)
1064 mac = nd6_ifptomac(ifp);
1065 } else if (sdl0->sa_family == AF_LINK) {
1066 struct sockaddr_dl *sdl;
1067 sdl = (struct sockaddr_dl *)sdl0;
1068 if (sdl->sdl_alen == ifp->if_addrlen)
1069 mac = LLADDR(sdl);
1070 }
1071 }
1072 if (tlladdr && mac) {
1073 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1074 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1075
1076 /* roundup to 8 bytes alignment! */
1077 optlen = (optlen + 7) & ~7;
1078
1079 m->m_pkthdr.len += optlen;
1080 m->m_len += optlen;
1081 icmp6len += optlen;
1082 bzero((caddr_t)nd_opt, optlen);
1083 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1084 nd_opt->nd_opt_len = optlen >> 3;
1085 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1086 } else
1087 flags &= ~ND_NA_FLAG_OVERRIDE;
1088
1089 ip6->ip6_plen = htons((u_short)icmp6len);
1090 nd_na->nd_na_flags_reserved = flags;
1091 nd_na->nd_na_cksum = 0;
1092 nd_na->nd_na_cksum =
1093 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1094
1095 if (send_sendso_input_hook != NULL) {
1096 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1097 sizeof(unsigned short), M_NOWAIT);
1098 if (mtag == NULL)
1099 goto bad;
1100 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1101 m_tag_prepend(m, mtag);
1102 }
1103
1104 ip6_output(m, NULL, &ro, 0, &im6o, NULL, NULL);
1105 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1106 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1107 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1108
1109 if (ro.ro_rt) { /* we don't cache this route. */
1110 RTFREE(ro.ro_rt);
1111 }
1112 return;
1113
1114 bad:
1115 if (ro.ro_rt) {
1116 RTFREE(ro.ro_rt);
1117 }
1118 m_freem(m);
1119 return;
1120 }
1121
1122 caddr_t
1123 nd6_ifptomac(struct ifnet *ifp)
1124 {
1125 switch (ifp->if_type) {
1126 case IFT_ARCNET:
1127 case IFT_ETHER:
1128 case IFT_FDDI:
1129 case IFT_IEEE1394:
1130 #ifdef IFT_L2VLAN
1131 case IFT_L2VLAN:
1132 #endif
1133 #ifdef IFT_IEEE80211
1134 case IFT_IEEE80211:
1135 #endif
1136 #ifdef IFT_CARP
1137 case IFT_CARP:
1138 #endif
1139 case IFT_INFINIBAND:
1140 case IFT_BRIDGE:
1141 case IFT_ISO88025:
1142 return IF_LLADDR(ifp);
1143 default:
1144 return NULL;
1145 }
1146 }
1147
1148 struct dadq {
1149 TAILQ_ENTRY(dadq) dad_list;
1150 struct ifaddr *dad_ifa;
1151 int dad_count; /* max NS to send */
1152 int dad_ns_tcount; /* # of trials to send NS */
1153 int dad_ns_ocount; /* NS sent so far */
1154 int dad_ns_icount;
1155 int dad_na_icount;
1156 struct callout dad_timer_ch;
1157 struct vnet *dad_vnet;
1158 };
1159
1160 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
1161 VNET_DEFINE(int, dad_init) = 0;
1162 #define V_dadq VNET(dadq)
1163 #define V_dad_init VNET(dad_init)
1164
1165 static struct dadq *
1166 nd6_dad_find(struct ifaddr *ifa)
1167 {
1168 struct dadq *dp;
1169
1170 for (dp = V_dadq.tqh_first; dp; dp = dp->dad_list.tqe_next) {
1171 if (dp->dad_ifa == ifa)
1172 return dp;
1173 }
1174 return NULL;
1175 }
1176
1177 static void
1178 nd6_dad_starttimer(struct dadq *dp, int ticks)
1179 {
1180
1181 callout_reset(&dp->dad_timer_ch, ticks,
1182 (void (*)(void *))nd6_dad_timer, (void *)dp);
1183 }
1184
1185 static void
1186 nd6_dad_stoptimer(struct dadq *dp)
1187 {
1188
1189 callout_stop(&dp->dad_timer_ch);
1190 }
1191
1192 /*
1193 * Start Duplicate Address Detection (DAD) for specified interface address.
1194 */
1195 void
1196 nd6_dad_start(struct ifaddr *ifa, int delay)
1197 {
1198 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1199 struct dadq *dp;
1200 char ip6buf[INET6_ADDRSTRLEN];
1201
1202 if (!V_dad_init) {
1203 TAILQ_INIT(&V_dadq);
1204 V_dad_init++;
1205 }
1206
1207 /*
1208 * If we don't need DAD, don't do it.
1209 * There are several cases:
1210 * - DAD is disabled (ip6_dad_count == 0)
1211 * - the interface address is anycast
1212 */
1213 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1214 log(LOG_DEBUG,
1215 "nd6_dad_start: called with non-tentative address "
1216 "%s(%s)\n",
1217 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1218 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1219 return;
1220 }
1221 if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1222 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1223 return;
1224 }
1225 if (!V_ip6_dad_count) {
1226 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1227 return;
1228 }
1229 if (ifa->ifa_ifp == NULL)
1230 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1231 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
1232 return;
1233 }
1234 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)
1235 return;
1236 if (nd6_dad_find(ifa) != NULL) {
1237 /* DAD already in progress */
1238 return;
1239 }
1240
1241 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
1242 if (dp == NULL) {
1243 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1244 "%s(%s)\n",
1245 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1246 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1247 return;
1248 }
1249 bzero(dp, sizeof(*dp));
1250 callout_init(&dp->dad_timer_ch, 0);
1251 #ifdef VIMAGE
1252 dp->dad_vnet = curvnet;
1253 #endif
1254 TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list);
1255
1256 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1257 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1258
1259 /*
1260 * Send NS packet for DAD, ip6_dad_count times.
1261 * Note that we must delay the first transmission, if this is the
1262 * first packet to be sent from the interface after interface
1263 * (re)initialization.
1264 */
1265 dp->dad_ifa = ifa;
1266 ifa_ref(ifa); /* just for safety */
1267 dp->dad_count = V_ip6_dad_count;
1268 dp->dad_ns_icount = dp->dad_na_icount = 0;
1269 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1270 if (delay == 0) {
1271 nd6_dad_ns_output(dp, ifa);
1272 nd6_dad_starttimer(dp,
1273 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1274 } else {
1275 nd6_dad_starttimer(dp, delay);
1276 }
1277 }
1278
1279 /*
1280 * terminate DAD unconditionally. used for address removals.
1281 */
1282 void
1283 nd6_dad_stop(struct ifaddr *ifa)
1284 {
1285 struct dadq *dp;
1286
1287 if (!V_dad_init)
1288 return;
1289 dp = nd6_dad_find(ifa);
1290 if (!dp) {
1291 /* DAD wasn't started yet */
1292 return;
1293 }
1294
1295 nd6_dad_stoptimer(dp);
1296
1297 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1298 free(dp, M_IP6NDP);
1299 dp = NULL;
1300 ifa_free(ifa);
1301 }
1302
1303 static void
1304 nd6_dad_timer(struct dadq *dp)
1305 {
1306 CURVNET_SET(dp->dad_vnet);
1307 int s;
1308 struct ifaddr *ifa = dp->dad_ifa;
1309 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1310 char ip6buf[INET6_ADDRSTRLEN];
1311
1312 s = splnet(); /* XXX */
1313
1314 /* Sanity check */
1315 if (ia == NULL) {
1316 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1317 goto done;
1318 }
1319 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1320 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1321 "%s(%s)\n",
1322 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1323 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1324 goto done;
1325 }
1326 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1327 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1328 "%s(%s)\n",
1329 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1330 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1331 goto done;
1332 }
1333
1334 /* timeouted with IFF_{RUNNING,UP} check */
1335 if (dp->dad_ns_tcount > V_dad_maxtry) {
1336 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
1337 if_name(ifa->ifa_ifp)));
1338
1339 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1340 free(dp, M_IP6NDP);
1341 dp = NULL;
1342 ifa_free(ifa);
1343 goto done;
1344 }
1345
1346 /* Need more checks? */
1347 if (dp->dad_ns_ocount < dp->dad_count) {
1348 /*
1349 * We have more NS to go. Send NS packet for DAD.
1350 */
1351 nd6_dad_ns_output(dp, ifa);
1352 nd6_dad_starttimer(dp,
1353 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1354 } else {
1355 /*
1356 * We have transmitted sufficient number of DAD packets.
1357 * See what we've got.
1358 */
1359 int duplicate;
1360
1361 duplicate = 0;
1362
1363 if (dp->dad_na_icount) {
1364 /*
1365 * the check is in nd6_dad_na_input(),
1366 * but just in case
1367 */
1368 duplicate++;
1369 }
1370
1371 if (dp->dad_ns_icount) {
1372 /* We've seen NS, means DAD has failed. */
1373 duplicate++;
1374 }
1375
1376 if (duplicate) {
1377 /* (*dp) will be freed in nd6_dad_duplicated() */
1378 dp = NULL;
1379 nd6_dad_duplicated(ifa);
1380 } else {
1381 /*
1382 * We are done with DAD. No NA came, no NS came.
1383 * No duplicate address found.
1384 */
1385 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1386
1387 nd6log((LOG_DEBUG,
1388 "%s: DAD complete for %s - no duplicates found\n",
1389 if_name(ifa->ifa_ifp),
1390 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1391
1392 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1393 free(dp, M_IP6NDP);
1394 dp = NULL;
1395 ifa_free(ifa);
1396 }
1397 }
1398
1399 done:
1400 splx(s);
1401 CURVNET_RESTORE();
1402 }
1403
1404 void
1405 nd6_dad_duplicated(struct ifaddr *ifa)
1406 {
1407 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1408 struct ifnet *ifp;
1409 struct dadq *dp;
1410 char ip6buf[INET6_ADDRSTRLEN];
1411
1412 dp = nd6_dad_find(ifa);
1413 if (dp == NULL) {
1414 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
1415 return;
1416 }
1417
1418 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1419 "NS in/out=%d/%d, NA in=%d\n",
1420 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1421 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
1422
1423 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1424 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1425
1426 /* We are done with DAD, with duplicate address found. (failure) */
1427 nd6_dad_stoptimer(dp);
1428
1429 ifp = ifa->ifa_ifp;
1430 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1431 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1432 log(LOG_ERR, "%s: manual intervention required\n",
1433 if_name(ifp));
1434
1435 /*
1436 * If the address is a link-local address formed from an interface
1437 * identifier based on the hardware address which is supposed to be
1438 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1439 * operation on the interface SHOULD be disabled.
1440 * [RFC 4862, Section 5.4.5]
1441 */
1442 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1443 struct in6_addr in6;
1444
1445 /*
1446 * To avoid over-reaction, we only apply this logic when we are
1447 * very sure that hardware addresses are supposed to be unique.
1448 */
1449 switch (ifp->if_type) {
1450 case IFT_ETHER:
1451 case IFT_FDDI:
1452 case IFT_ATM:
1453 case IFT_IEEE1394:
1454 #ifdef IFT_IEEE80211
1455 case IFT_IEEE80211:
1456 #endif
1457 case IFT_INFINIBAND:
1458 in6 = ia->ia_addr.sin6_addr;
1459 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1460 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1461 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1462 log(LOG_ERR, "%s: possible hardware address "
1463 "duplication detected, disable IPv6\n",
1464 if_name(ifp));
1465 }
1466 break;
1467 }
1468 }
1469
1470 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1471 free(dp, M_IP6NDP);
1472 dp = NULL;
1473 ifa_free(ifa);
1474 }
1475
1476 static void
1477 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
1478 {
1479 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1480 struct ifnet *ifp = ifa->ifa_ifp;
1481
1482 dp->dad_ns_tcount++;
1483 if ((ifp->if_flags & IFF_UP) == 0) {
1484 return;
1485 }
1486 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1487 return;
1488 }
1489
1490 dp->dad_ns_ocount++;
1491 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
1492 }
1493
1494 static void
1495 nd6_dad_ns_input(struct ifaddr *ifa)
1496 {
1497 struct in6_ifaddr *ia;
1498 struct ifnet *ifp;
1499 const struct in6_addr *taddr6;
1500 struct dadq *dp;
1501 int duplicate;
1502
1503 if (ifa == NULL)
1504 panic("ifa == NULL in nd6_dad_ns_input");
1505
1506 ia = (struct in6_ifaddr *)ifa;
1507 ifp = ifa->ifa_ifp;
1508 taddr6 = &ia->ia_addr.sin6_addr;
1509 duplicate = 0;
1510 dp = nd6_dad_find(ifa);
1511
1512 /* Quickhack - completely ignore DAD NS packets */
1513 if (V_dad_ignore_ns) {
1514 char ip6buf[INET6_ADDRSTRLEN];
1515 nd6log((LOG_INFO,
1516 "nd6_dad_ns_input: ignoring DAD NS packet for "
1517 "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6),
1518 if_name(ifa->ifa_ifp)));
1519 return;
1520 }
1521
1522 /*
1523 * if I'm yet to start DAD, someone else started using this address
1524 * first. I have a duplicate and you win.
1525 */
1526 if (dp == NULL || dp->dad_ns_ocount == 0)
1527 duplicate++;
1528
1529 /* XXX more checks for loopback situation - see nd6_dad_timer too */
1530
1531 if (duplicate) {
1532 dp = NULL; /* will be freed in nd6_dad_duplicated() */
1533 nd6_dad_duplicated(ifa);
1534 } else {
1535 /*
1536 * not sure if I got a duplicate.
1537 * increment ns count and see what happens.
1538 */
1539 if (dp)
1540 dp->dad_ns_icount++;
1541 }
1542 }
1543
1544 static void
1545 nd6_dad_na_input(struct ifaddr *ifa)
1546 {
1547 struct dadq *dp;
1548
1549 if (ifa == NULL)
1550 panic("ifa == NULL in nd6_dad_na_input");
1551
1552 dp = nd6_dad_find(ifa);
1553 if (dp)
1554 dp->dad_na_icount++;
1555
1556 /* remove the address. */
1557 nd6_dad_duplicated(ifa);
1558 }
Cache object: 66130407da616f97daa35c99a4f9c1a8
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