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/10.1/sys/netinet6/nd6_nbr.c 273188 2014-10-16 22:00:24Z 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 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
89 const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
90
91 static VNET_DEFINE(int, dad_ignore_ns) = 0; /* ignore NS in DAD
92 - specwise incorrect */
93 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to
94 transmit DAD packet */
95 #define V_dad_ignore_ns VNET(dad_ignore_ns)
96 #define V_dad_maxtry VNET(dad_maxtry)
97
98 /*
99 * Input a Neighbor Solicitation Message.
100 *
101 * Based on RFC 2461
102 * Based on RFC 2462 (duplicate address detection)
103 */
104 void
105 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
106 {
107 struct ifnet *ifp = m->m_pkthdr.rcvif;
108 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
109 struct nd_neighbor_solicit *nd_ns;
110 struct in6_addr saddr6 = ip6->ip6_src;
111 struct in6_addr daddr6 = ip6->ip6_dst;
112 struct in6_addr taddr6;
113 struct in6_addr myaddr6;
114 char *lladdr = NULL;
115 struct ifaddr *ifa = NULL;
116 int lladdrlen = 0;
117 int anycast = 0, proxy = 0, tentative = 0;
118 int tlladdr;
119 int rflag;
120 union nd_opts ndopts;
121 struct sockaddr_dl proxydl;
122 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
123
124 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
125 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
126 rflag = 0;
127 #ifndef PULLDOWN_TEST
128 IP6_EXTHDR_CHECK(m, off, icmp6len,);
129 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
130 #else
131 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
132 if (nd_ns == NULL) {
133 ICMP6STAT_INC(icp6s_tooshort);
134 return;
135 }
136 #endif
137 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
138 taddr6 = nd_ns->nd_ns_target;
139 if (in6_setscope(&taddr6, ifp, NULL) != 0)
140 goto bad;
141
142 if (ip6->ip6_hlim != 255) {
143 nd6log((LOG_ERR,
144 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
145 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
146 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
147 goto bad;
148 }
149
150 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
151 /* dst has to be a solicited node multicast address. */
152 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
153 /* don't check ifindex portion */
154 daddr6.s6_addr32[1] == 0 &&
155 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
156 daddr6.s6_addr8[12] == 0xff) {
157 ; /* good */
158 } else {
159 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
160 "(wrong ip6 dst)\n"));
161 goto bad;
162 }
163 } else if (!V_nd6_onlink_ns_rfc4861) {
164 struct sockaddr_in6 src_sa6;
165
166 /*
167 * According to recent IETF discussions, it is not a good idea
168 * to accept a NS from an address which would not be deemed
169 * to be a neighbor otherwise. This point is expected to be
170 * clarified in future revisions of the specification.
171 */
172 bzero(&src_sa6, sizeof(src_sa6));
173 src_sa6.sin6_family = AF_INET6;
174 src_sa6.sin6_len = sizeof(src_sa6);
175 src_sa6.sin6_addr = saddr6;
176 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
177 nd6log((LOG_INFO, "nd6_ns_input: "
178 "NS packet from non-neighbor\n"));
179 goto bad;
180 }
181 }
182
183 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
184 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
185 goto bad;
186 }
187
188 icmp6len -= sizeof(*nd_ns);
189 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
190 if (nd6_options(&ndopts) < 0) {
191 nd6log((LOG_INFO,
192 "nd6_ns_input: invalid ND option, ignored\n"));
193 /* nd6_options have incremented stats */
194 goto freeit;
195 }
196
197 if (ndopts.nd_opts_src_lladdr) {
198 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
199 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
200 }
201
202 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
203 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
204 "(link-layer address option)\n"));
205 goto bad;
206 }
207
208 /*
209 * Attaching target link-layer address to the NA?
210 * (RFC 2461 7.2.4)
211 *
212 * NS IP dst is unicast/anycast MUST NOT add
213 * NS IP dst is solicited-node multicast MUST add
214 *
215 * In implementation, we add target link-layer address by default.
216 * We do not add one in MUST NOT cases.
217 */
218 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
219 tlladdr = 0;
220 else
221 tlladdr = 1;
222
223 /*
224 * Target address (taddr6) must be either:
225 * (1) Valid unicast/anycast address for my receiving interface,
226 * (2) Unicast address for which I'm offering proxy service, or
227 * (3) "tentative" address on which DAD is being performed.
228 */
229 /* (1) and (3) check. */
230 if (ifp->if_carp)
231 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
232 else
233 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
234
235 /* (2) check. */
236 if (ifa == NULL) {
237 struct route_in6 ro;
238 int need_proxy;
239
240 bzero(&ro, sizeof(ro));
241 ro.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
242 ro.ro_dst.sin6_family = AF_INET6;
243 ro.ro_dst.sin6_addr = taddr6;
244
245 /* Always use the default FIB. */
246 #ifdef RADIX_MPATH
247 rtalloc_mpath_fib((struct route *)&ro, RTF_ANNOUNCE,
248 RT_DEFAULT_FIB);
249 #else
250 in6_rtalloc(&ro, RT_DEFAULT_FIB);
251 #endif
252 need_proxy = (ro.ro_rt &&
253 (ro.ro_rt->rt_flags & RTF_ANNOUNCE) != 0 &&
254 ro.ro_rt->rt_gateway->sa_family == AF_LINK);
255 if (ro.ro_rt != NULL) {
256 if (need_proxy)
257 proxydl = *SDL(ro.ro_rt->rt_gateway);
258 RTFREE(ro.ro_rt);
259 }
260 if (need_proxy) {
261 /*
262 * proxy NDP for single entry
263 */
264 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
265 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
266 if (ifa)
267 proxy = 1;
268 }
269 }
270 if (ifa == NULL) {
271 /*
272 * We've got an NS packet, and we don't have that adddress
273 * assigned for us. We MUST silently ignore it.
274 * See RFC2461 7.2.3.
275 */
276 goto freeit;
277 }
278 myaddr6 = *IFA_IN6(ifa);
279 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
280 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
281 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
282 goto freeit;
283
284 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
285 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
286 "(if %d, NS packet %d)\n",
287 ip6_sprintf(ip6bufs, &taddr6),
288 ifp->if_addrlen, lladdrlen - 2));
289 goto bad;
290 }
291
292 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
293 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
294 ip6_sprintf(ip6bufs, &saddr6)));
295 goto freeit;
296 }
297
298 /*
299 * We have neighbor solicitation packet, with target address equals to
300 * one of my tentative address.
301 *
302 * src addr how to process?
303 * --- ---
304 * multicast of course, invalid (rejected in ip6_input)
305 * unicast somebody is doing address resolution -> ignore
306 * unspec dup address detection
307 *
308 * The processing is defined in RFC 2462.
309 */
310 if (tentative) {
311 /*
312 * If source address is unspecified address, it is for
313 * duplicate address detection.
314 *
315 * If not, the packet is for addess resolution;
316 * silently ignore it.
317 */
318 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
319 nd6_dad_ns_input(ifa);
320
321 goto freeit;
322 }
323
324 /*
325 * If the source address is unspecified address, entries must not
326 * be created or updated.
327 * It looks that sender is performing DAD. Output NA toward
328 * all-node multicast address, to tell the sender that I'm using
329 * the address.
330 * S bit ("solicited") must be zero.
331 */
332 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
333 struct in6_addr in6_all;
334
335 in6_all = in6addr_linklocal_allnodes;
336 if (in6_setscope(&in6_all, ifp, NULL) != 0)
337 goto bad;
338 nd6_na_output_fib(ifp, &in6_all, &taddr6,
339 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
340 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
341 M_GETFIB(m));
342 goto freeit;
343 }
344
345 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
346 ND_NEIGHBOR_SOLICIT, 0);
347
348 nd6_na_output_fib(ifp, &saddr6, &taddr6,
349 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
350 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
351 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
352 freeit:
353 if (ifa != NULL)
354 ifa_free(ifa);
355 m_freem(m);
356 return;
357
358 bad:
359 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
360 ip6_sprintf(ip6bufs, &saddr6)));
361 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
362 ip6_sprintf(ip6bufs, &daddr6)));
363 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
364 ip6_sprintf(ip6bufs, &taddr6)));
365 ICMP6STAT_INC(icp6s_badns);
366 if (ifa != NULL)
367 ifa_free(ifa);
368 m_freem(m);
369 }
370
371 /*
372 * Output a Neighbor Solicitation Message. Caller specifies:
373 * - ICMP6 header source IP6 address
374 * - ND6 header target IP6 address
375 * - ND6 header source datalink address
376 *
377 * Based on RFC 2461
378 * Based on RFC 2462 (duplicate address detection)
379 *
380 * ln - for source address determination
381 * dad - duplicate address detection
382 */
383 void
384 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
385 const struct in6_addr *taddr6, struct llentry *ln, int dad)
386 {
387 struct mbuf *m;
388 struct m_tag *mtag;
389 struct ip6_hdr *ip6;
390 struct nd_neighbor_solicit *nd_ns;
391 struct ip6_moptions im6o;
392 int icmp6len;
393 int maxlen;
394 caddr_t mac;
395 struct route_in6 ro;
396
397 if (IN6_IS_ADDR_MULTICAST(taddr6))
398 return;
399
400 /* estimate the size of message */
401 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
402 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
403 if (max_linkhdr + maxlen >= MCLBYTES) {
404 #ifdef DIAGNOSTIC
405 printf("nd6_ns_output: max_linkhdr + maxlen >= MCLBYTES "
406 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
407 #endif
408 return;
409 }
410
411 if (max_linkhdr + maxlen > MHLEN)
412 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
413 else
414 m = m_gethdr(M_NOWAIT, MT_DATA);
415 if (m == NULL)
416 return;
417
418 bzero(&ro, sizeof(ro));
419
420 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
421 m->m_flags |= M_MCAST;
422 im6o.im6o_multicast_ifp = ifp;
423 im6o.im6o_multicast_hlim = 255;
424 im6o.im6o_multicast_loop = 0;
425 }
426
427 icmp6len = sizeof(*nd_ns);
428 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
429 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
430
431 /* fill neighbor solicitation packet */
432 ip6 = mtod(m, struct ip6_hdr *);
433 ip6->ip6_flow = 0;
434 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
435 ip6->ip6_vfc |= IPV6_VERSION;
436 /* ip6->ip6_plen will be set later */
437 ip6->ip6_nxt = IPPROTO_ICMPV6;
438 ip6->ip6_hlim = 255;
439 if (daddr6)
440 ip6->ip6_dst = *daddr6;
441 else {
442 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
443 ip6->ip6_dst.s6_addr16[1] = 0;
444 ip6->ip6_dst.s6_addr32[1] = 0;
445 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
446 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
447 ip6->ip6_dst.s6_addr8[12] = 0xff;
448 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
449 goto bad;
450 }
451 if (!dad) {
452 struct ifaddr *ifa;
453
454 /*
455 * RFC2461 7.2.2:
456 * "If the source address of the packet prompting the
457 * solicitation is the same as one of the addresses assigned
458 * to the outgoing interface, that address SHOULD be placed
459 * in the IP Source Address of the outgoing solicitation.
460 * Otherwise, any one of the addresses assigned to the
461 * interface should be used."
462 *
463 * We use the source address for the prompting packet
464 * (saddr6), if:
465 * - saddr6 is given from the caller (by giving "ln"), and
466 * - saddr6 belongs to the outgoing interface.
467 * Otherwise, we perform the source address selection as usual.
468 */
469 struct in6_addr *hsrc;
470
471 hsrc = NULL;
472 if (ln != NULL) {
473 LLE_RLOCK(ln);
474 if (ln->la_hold != NULL) {
475 struct ip6_hdr *hip6; /* hold ip6 */
476
477 /*
478 * assuming every packet in la_hold has the same IP
479 * header
480 */
481 hip6 = mtod(ln->la_hold, struct ip6_hdr *);
482 /* XXX pullup? */
483 if (sizeof(*hip6) < ln->la_hold->m_len) {
484 ip6->ip6_src = hip6->ip6_src;
485 hsrc = &hip6->ip6_src;
486 }
487 }
488 LLE_RUNLOCK(ln);
489 }
490 if (hsrc && (ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
491 hsrc)) != NULL) {
492 /* ip6_src set already. */
493 ifa_free(ifa);
494 } else {
495 int error;
496 struct sockaddr_in6 dst_sa;
497 struct in6_addr src_in;
498 struct ifnet *oifp;
499
500 bzero(&dst_sa, sizeof(dst_sa));
501 dst_sa.sin6_family = AF_INET6;
502 dst_sa.sin6_len = sizeof(dst_sa);
503 dst_sa.sin6_addr = ip6->ip6_dst;
504
505 oifp = ifp;
506 error = in6_selectsrc(&dst_sa, NULL,
507 NULL, &ro, NULL, &oifp, &src_in);
508 if (error) {
509 char ip6buf[INET6_ADDRSTRLEN];
510 nd6log((LOG_DEBUG,
511 "nd6_ns_output: source can't be "
512 "determined: dst=%s, error=%d\n",
513 ip6_sprintf(ip6buf, &dst_sa.sin6_addr),
514 error));
515 goto bad;
516 }
517 ip6->ip6_src = src_in;
518 }
519 } else {
520 /*
521 * Source address for DAD packet must always be IPv6
522 * unspecified address. (0::0)
523 * We actually don't have to 0-clear the address (we did it
524 * above), but we do so here explicitly to make the intention
525 * clearer.
526 */
527 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
528 }
529 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
530 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
531 nd_ns->nd_ns_code = 0;
532 nd_ns->nd_ns_reserved = 0;
533 nd_ns->nd_ns_target = *taddr6;
534 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
535
536 /*
537 * Add source link-layer address option.
538 *
539 * spec implementation
540 * --- ---
541 * DAD packet MUST NOT do not add the option
542 * there's no link layer address:
543 * impossible do not add the option
544 * there's link layer address:
545 * Multicast NS MUST add one add the option
546 * Unicast NS SHOULD add one add the option
547 */
548 if (!dad && (mac = nd6_ifptomac(ifp))) {
549 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
550 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
551 /* 8 byte alignments... */
552 optlen = (optlen + 7) & ~7;
553
554 m->m_pkthdr.len += optlen;
555 m->m_len += optlen;
556 icmp6len += optlen;
557 bzero((caddr_t)nd_opt, optlen);
558 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
559 nd_opt->nd_opt_len = optlen >> 3;
560 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
561 }
562
563 ip6->ip6_plen = htons((u_short)icmp6len);
564 nd_ns->nd_ns_cksum = 0;
565 nd_ns->nd_ns_cksum =
566 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
567
568 if (send_sendso_input_hook != NULL) {
569 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
570 sizeof(unsigned short), M_NOWAIT);
571 if (mtag == NULL)
572 goto bad;
573 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
574 m_tag_prepend(m, mtag);
575 }
576
577 ip6_output(m, NULL, &ro, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL, NULL);
578 icmp6_ifstat_inc(ifp, ifs6_out_msg);
579 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
580 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
581
582 /* We don't cache this route. */
583 RO_RTFREE(&ro);
584
585 return;
586
587 bad:
588 if (ro.ro_rt) {
589 RTFREE(ro.ro_rt);
590 }
591 m_freem(m);
592 return;
593 }
594
595 /*
596 * Neighbor advertisement input handling.
597 *
598 * Based on RFC 2461
599 * Based on RFC 2462 (duplicate address detection)
600 *
601 * the following items are not implemented yet:
602 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
603 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
604 */
605 void
606 nd6_na_input(struct mbuf *m, int off, int icmp6len)
607 {
608 struct ifnet *ifp = m->m_pkthdr.rcvif;
609 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
610 struct nd_neighbor_advert *nd_na;
611 struct in6_addr daddr6 = ip6->ip6_dst;
612 struct in6_addr taddr6;
613 int flags;
614 int is_router;
615 int is_solicited;
616 int is_override;
617 char *lladdr = NULL;
618 int lladdrlen = 0;
619 int checklink = 0;
620 struct ifaddr *ifa;
621 struct llentry *ln = NULL;
622 union nd_opts ndopts;
623 struct mbuf *chain = NULL;
624 struct m_tag *mtag;
625 struct sockaddr_in6 sin6;
626 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
627
628 if (ip6->ip6_hlim != 255) {
629 nd6log((LOG_ERR,
630 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
631 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
632 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
633 goto bad;
634 }
635
636 #ifndef PULLDOWN_TEST
637 IP6_EXTHDR_CHECK(m, off, icmp6len,);
638 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
639 #else
640 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
641 if (nd_na == NULL) {
642 ICMP6STAT_INC(icp6s_tooshort);
643 return;
644 }
645 #endif
646
647 flags = nd_na->nd_na_flags_reserved;
648 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
649 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
650 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
651
652 taddr6 = nd_na->nd_na_target;
653 if (in6_setscope(&taddr6, ifp, NULL))
654 goto bad; /* XXX: impossible */
655
656 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
657 nd6log((LOG_ERR,
658 "nd6_na_input: invalid target address %s\n",
659 ip6_sprintf(ip6bufs, &taddr6)));
660 goto bad;
661 }
662 if (IN6_IS_ADDR_MULTICAST(&daddr6))
663 if (is_solicited) {
664 nd6log((LOG_ERR,
665 "nd6_na_input: a solicited adv is multicasted\n"));
666 goto bad;
667 }
668
669 icmp6len -= sizeof(*nd_na);
670 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
671 if (nd6_options(&ndopts) < 0) {
672 nd6log((LOG_INFO,
673 "nd6_na_input: invalid ND option, ignored\n"));
674 /* nd6_options have incremented stats */
675 goto freeit;
676 }
677
678 if (ndopts.nd_opts_tgt_lladdr) {
679 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
680 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
681 }
682
683 /*
684 * This effectively disables the DAD check on a non-master CARP
685 * address.
686 */
687 if (ifp->if_carp)
688 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
689 else
690 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
691
692 /*
693 * Target address matches one of my interface address.
694 *
695 * If my address is tentative, this means that there's somebody
696 * already using the same address as mine. This indicates DAD failure.
697 * This is defined in RFC 2462.
698 *
699 * Otherwise, process as defined in RFC 2461.
700 */
701 if (ifa
702 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
703 ifa_free(ifa);
704 nd6_dad_na_input(ifa);
705 goto freeit;
706 }
707
708 /* Just for safety, maybe unnecessary. */
709 if (ifa) {
710 ifa_free(ifa);
711 log(LOG_ERR,
712 "nd6_na_input: duplicate IP6 address %s\n",
713 ip6_sprintf(ip6bufs, &taddr6));
714 goto freeit;
715 }
716
717 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
718 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
719 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
720 ifp->if_addrlen, lladdrlen - 2));
721 goto bad;
722 }
723
724 /*
725 * If no neighbor cache entry is found, NA SHOULD silently be
726 * discarded.
727 */
728 IF_AFDATA_RLOCK(ifp);
729 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
730 IF_AFDATA_RUNLOCK(ifp);
731 if (ln == NULL) {
732 goto freeit;
733 }
734
735 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
736 /*
737 * If the link-layer has address, and no lladdr option came,
738 * discard the packet.
739 */
740 if (ifp->if_addrlen && lladdr == NULL) {
741 goto freeit;
742 }
743
744 /*
745 * Record link-layer address, and update the state.
746 */
747 bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
748 ln->la_flags |= LLE_VALID;
749 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
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 EVENTHANDLER_INVOKE(lle_event, ln,
826 LLENTRY_RESOLVED);
827 }
828
829 /*
830 * If solicited, make the state REACHABLE.
831 * If not solicited and the link-layer address was
832 * changed, make it STALE.
833 */
834 if (is_solicited) {
835 ln->ln_state = ND6_LLINFO_REACHABLE;
836 ln->ln_byhint = 0;
837 if (!ND6_LLINFO_PERMANENT(ln)) {
838 nd6_llinfo_settimer_locked(ln,
839 (long)ND_IFINFO(ifp)->reachable * hz);
840 }
841 } else {
842 if (lladdr != NULL && llchange) {
843 ln->ln_state = ND6_LLINFO_STALE;
844 nd6_llinfo_settimer_locked(ln,
845 (long)V_nd6_gctimer * hz);
846 }
847 }
848 }
849
850 if (ln->ln_router && !is_router) {
851 /*
852 * The peer dropped the router flag.
853 * Remove the sender from the Default Router List and
854 * update the Destination Cache entries.
855 */
856 struct nd_defrouter *dr;
857 struct in6_addr *in6;
858
859 in6 = &L3_ADDR_SIN6(ln)->sin6_addr;
860
861 /*
862 * Lock to protect the default router list.
863 * XXX: this might be unnecessary, since this function
864 * is only called under the network software interrupt
865 * context. However, we keep it just for safety.
866 */
867 dr = defrouter_lookup(in6, ln->lle_tbl->llt_ifp);
868 if (dr)
869 defrtrlist_del(dr);
870 else if (ND_IFINFO(ln->lle_tbl->llt_ifp)->flags &
871 ND6_IFF_ACCEPT_RTADV) {
872 /*
873 * Even if the neighbor is not in the default
874 * router list, the neighbor may be used
875 * as a next hop for some destinations
876 * (e.g. redirect case). So we must
877 * call rt6_flush explicitly.
878 */
879 rt6_flush(&ip6->ip6_src, ifp);
880 }
881 }
882 ln->ln_router = is_router;
883 }
884 /* XXX - QL
885 * Does this matter?
886 * rt->rt_flags &= ~RTF_REJECT;
887 */
888 ln->la_asked = 0;
889 if (ln->la_hold) {
890 struct mbuf *m_hold, *m_hold_next;
891
892 /*
893 * reset the la_hold in advance, to explicitly
894 * prevent a la_hold lookup in nd6_output()
895 * (wouldn't happen, though...)
896 */
897 for (m_hold = ln->la_hold, ln->la_hold = NULL;
898 m_hold; m_hold = m_hold_next) {
899 m_hold_next = m_hold->m_nextpkt;
900 m_hold->m_nextpkt = NULL;
901 /*
902 * we assume ifp is not a loopback here, so just set
903 * the 2nd argument as the 1st one.
904 */
905
906 if (send_sendso_input_hook != NULL) {
907 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
908 sizeof(unsigned short), M_NOWAIT);
909 if (mtag == NULL)
910 goto bad;
911 m_tag_prepend(m, mtag);
912 }
913
914 nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
915 }
916 }
917 freeit:
918 if (ln != NULL) {
919 if (chain)
920 memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
921 LLE_WUNLOCK(ln);
922
923 if (chain)
924 nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
925 }
926 if (checklink)
927 pfxlist_onlink_check();
928
929 m_freem(m);
930 return;
931
932 bad:
933 if (ln != NULL)
934 LLE_WUNLOCK(ln);
935
936 ICMP6STAT_INC(icp6s_badna);
937 m_freem(m);
938 }
939
940 /*
941 * Neighbor advertisement output handling.
942 *
943 * Based on RFC 2461
944 *
945 * the following items are not implemented yet:
946 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
947 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
948 *
949 * tlladdr - 1 if include target link-layer address
950 * sdl0 - sockaddr_dl (= proxy NA) or NULL
951 */
952 static void
953 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
954 const struct in6_addr *taddr6, u_long flags, int tlladdr,
955 struct sockaddr *sdl0, u_int fibnum)
956 {
957 struct mbuf *m;
958 struct m_tag *mtag;
959 struct ifnet *oifp;
960 struct ip6_hdr *ip6;
961 struct nd_neighbor_advert *nd_na;
962 struct ip6_moptions im6o;
963 struct in6_addr src, daddr6;
964 struct sockaddr_in6 dst_sa;
965 int icmp6len, maxlen, error;
966 caddr_t mac = NULL;
967 struct route_in6 ro;
968
969 bzero(&ro, sizeof(ro));
970
971 daddr6 = *daddr6_0; /* make a local copy for modification */
972
973 /* estimate the size of message */
974 maxlen = sizeof(*ip6) + sizeof(*nd_na);
975 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
976 if (max_linkhdr + maxlen >= MCLBYTES) {
977 #ifdef DIAGNOSTIC
978 printf("nd6_na_output: max_linkhdr + maxlen >= MCLBYTES "
979 "(%d + %d > %d)\n", max_linkhdr, maxlen, MCLBYTES);
980 #endif
981 return;
982 }
983
984 if (max_linkhdr + maxlen > MHLEN)
985 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
986 else
987 m = m_gethdr(M_NOWAIT, MT_DATA);
988 if (m == NULL)
989 return;
990 M_SETFIB(m, fibnum);
991
992 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
993 m->m_flags |= M_MCAST;
994 im6o.im6o_multicast_ifp = ifp;
995 im6o.im6o_multicast_hlim = 255;
996 im6o.im6o_multicast_loop = 0;
997 }
998
999 icmp6len = sizeof(*nd_na);
1000 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
1001 m->m_data += max_linkhdr; /* or MH_ALIGN() equivalent? */
1002
1003 /* fill neighbor advertisement packet */
1004 ip6 = mtod(m, struct ip6_hdr *);
1005 ip6->ip6_flow = 0;
1006 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1007 ip6->ip6_vfc |= IPV6_VERSION;
1008 ip6->ip6_nxt = IPPROTO_ICMPV6;
1009 ip6->ip6_hlim = 255;
1010 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
1011 /* reply to DAD */
1012 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
1013 daddr6.s6_addr16[1] = 0;
1014 daddr6.s6_addr32[1] = 0;
1015 daddr6.s6_addr32[2] = 0;
1016 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
1017 if (in6_setscope(&daddr6, ifp, NULL))
1018 goto bad;
1019
1020 flags &= ~ND_NA_FLAG_SOLICITED;
1021 }
1022 ip6->ip6_dst = daddr6;
1023 bzero(&dst_sa, sizeof(struct sockaddr_in6));
1024 dst_sa.sin6_family = AF_INET6;
1025 dst_sa.sin6_len = sizeof(struct sockaddr_in6);
1026 dst_sa.sin6_addr = daddr6;
1027
1028 /*
1029 * Select a source whose scope is the same as that of the dest.
1030 */
1031 bcopy(&dst_sa, &ro.ro_dst, sizeof(dst_sa));
1032 oifp = ifp;
1033 error = in6_selectsrc(&dst_sa, NULL, NULL, &ro, NULL, &oifp, &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 /* We don't cache this route. */
1110 RO_RTFREE(&ro);
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 #ifndef BURN_BRIDGES
1123 void
1124 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1125 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1126 struct sockaddr *sdl0)
1127 {
1128
1129 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1130 RT_DEFAULT_FIB);
1131 }
1132 #endif
1133
1134 caddr_t
1135 nd6_ifptomac(struct ifnet *ifp)
1136 {
1137 switch (ifp->if_type) {
1138 case IFT_ARCNET:
1139 case IFT_ETHER:
1140 case IFT_FDDI:
1141 case IFT_IEEE1394:
1142 #ifdef IFT_L2VLAN
1143 case IFT_L2VLAN:
1144 #endif
1145 #ifdef IFT_IEEE80211
1146 case IFT_IEEE80211:
1147 #endif
1148 case IFT_INFINIBAND:
1149 case IFT_BRIDGE:
1150 case IFT_ISO88025:
1151 return IF_LLADDR(ifp);
1152 default:
1153 return NULL;
1154 }
1155 }
1156
1157 struct dadq {
1158 TAILQ_ENTRY(dadq) dad_list;
1159 struct ifaddr *dad_ifa;
1160 int dad_count; /* max NS to send */
1161 int dad_ns_tcount; /* # of trials to send NS */
1162 int dad_ns_ocount; /* NS sent so far */
1163 int dad_ns_icount;
1164 int dad_na_icount;
1165 struct callout dad_timer_ch;
1166 struct vnet *dad_vnet;
1167 };
1168
1169 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
1170 static VNET_DEFINE(struct rwlock, dad_rwlock);
1171 #define V_dadq VNET(dadq)
1172 #define V_dad_rwlock VNET(dad_rwlock)
1173
1174 #define DADQ_LOCK_INIT() rw_init(&V_dad_rwlock, "nd6 DAD queue")
1175 #define DADQ_LOCK_DESTROY() rw_destroy(&V_dad_rwlock)
1176 #define DADQ_LOCK_INITIALIZED() rw_initialized(&V_dad_rwlock)
1177 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock)
1178 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock)
1179 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock)
1180 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock)
1181
1182 static struct dadq *
1183 nd6_dad_find(struct ifaddr *ifa)
1184 {
1185 struct dadq *dp;
1186
1187 DADQ_RLOCK();
1188 TAILQ_FOREACH(dp, &V_dadq, dad_list)
1189 if (dp->dad_ifa == ifa)
1190 break;
1191 DADQ_RUNLOCK();
1192
1193 return (dp);
1194 }
1195
1196 static void
1197 nd6_dad_starttimer(struct dadq *dp, int ticks)
1198 {
1199
1200 callout_reset(&dp->dad_timer_ch, ticks,
1201 (void (*)(void *))nd6_dad_timer, (void *)dp);
1202 }
1203
1204 static void
1205 nd6_dad_stoptimer(struct dadq *dp)
1206 {
1207
1208 callout_stop(&dp->dad_timer_ch);
1209 }
1210
1211 /*
1212 * Start Duplicate Address Detection (DAD) for specified interface address.
1213 */
1214 void
1215 nd6_dad_start(struct ifaddr *ifa, int delay)
1216 {
1217 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1218 struct dadq *dp;
1219 char ip6buf[INET6_ADDRSTRLEN];
1220
1221 if (DADQ_LOCK_INITIALIZED() == 0) {
1222 DADQ_LOCK_INIT();
1223 TAILQ_INIT(&V_dadq);
1224 }
1225
1226 /*
1227 * If we don't need DAD, don't do it.
1228 * There are several cases:
1229 * - DAD is disabled (ip6_dad_count == 0)
1230 * - the interface address is anycast
1231 */
1232 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1233 log(LOG_DEBUG,
1234 "nd6_dad_start: called with non-tentative address "
1235 "%s(%s)\n",
1236 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1237 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1238 return;
1239 }
1240 if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1241 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1242 return;
1243 }
1244 if (!V_ip6_dad_count) {
1245 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1246 return;
1247 }
1248 if (ifa->ifa_ifp == NULL)
1249 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1250 if (!(ifa->ifa_ifp->if_flags & IFF_UP)) {
1251 return;
1252 }
1253 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)
1254 return;
1255 if (nd6_dad_find(ifa) != NULL) {
1256 /* DAD already in progress */
1257 return;
1258 }
1259
1260 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT);
1261 if (dp == NULL) {
1262 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1263 "%s(%s)\n",
1264 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1265 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1266 return;
1267 }
1268 bzero(dp, sizeof(*dp));
1269 callout_init(&dp->dad_timer_ch, 0);
1270 #ifdef VIMAGE
1271 dp->dad_vnet = curvnet;
1272 #endif
1273 DADQ_WLOCK();
1274 TAILQ_INSERT_TAIL(&V_dadq, (struct dadq *)dp, dad_list);
1275 DADQ_WUNLOCK();
1276
1277 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1278 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1279
1280 /*
1281 * Send NS packet for DAD, ip6_dad_count times.
1282 * Note that we must delay the first transmission, if this is the
1283 * first packet to be sent from the interface after interface
1284 * (re)initialization.
1285 */
1286 dp->dad_ifa = ifa;
1287 ifa_ref(ifa); /* just for safety */
1288 dp->dad_count = V_ip6_dad_count;
1289 dp->dad_ns_icount = dp->dad_na_icount = 0;
1290 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1291 if (delay == 0) {
1292 nd6_dad_ns_output(dp, ifa);
1293 nd6_dad_starttimer(dp,
1294 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1295 } else {
1296 nd6_dad_starttimer(dp, delay);
1297 }
1298 }
1299
1300 /*
1301 * terminate DAD unconditionally. used for address removals.
1302 */
1303 void
1304 nd6_dad_stop(struct ifaddr *ifa)
1305 {
1306 struct dadq *dp;
1307
1308 if (DADQ_LOCK_INITIALIZED() == 0)
1309 return;
1310 dp = nd6_dad_find(ifa);
1311 if (!dp) {
1312 /* DAD wasn't started yet */
1313 return;
1314 }
1315
1316 nd6_dad_stoptimer(dp);
1317
1318 DADQ_WLOCK();
1319 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1320 DADQ_WUNLOCK();
1321 free(dp, M_IP6NDP);
1322 dp = NULL;
1323 ifa_free(ifa);
1324 }
1325
1326 static void
1327 nd6_dad_timer(struct dadq *dp)
1328 {
1329 CURVNET_SET(dp->dad_vnet);
1330 struct ifaddr *ifa = dp->dad_ifa;
1331 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1332 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1333 char ip6buf[INET6_ADDRSTRLEN];
1334
1335 /* Sanity check */
1336 if (ia == NULL) {
1337 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1338 goto done;
1339 }
1340 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
1341 /* Do not need DAD for ifdisabled interface. */
1342 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1343 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1344 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1345 free(dp, M_IP6NDP);
1346 dp = NULL;
1347 ifa_free(ifa);
1348 goto done;
1349 }
1350 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1351 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1352 "%s(%s)\n",
1353 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1354 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1355 goto done;
1356 }
1357 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1358 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1359 "%s(%s)\n",
1360 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1361 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1362 goto done;
1363 }
1364
1365 /* timeouted with IFF_{RUNNING,UP} check */
1366 if (dp->dad_ns_tcount > V_dad_maxtry) {
1367 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
1368 if_name(ifa->ifa_ifp)));
1369
1370 DADQ_WLOCK();
1371 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1372 DADQ_WUNLOCK();
1373 free(dp, M_IP6NDP);
1374 dp = NULL;
1375 ifa_free(ifa);
1376 goto done;
1377 }
1378
1379 /* Need more checks? */
1380 if (dp->dad_ns_ocount < dp->dad_count) {
1381 /*
1382 * We have more NS to go. Send NS packet for DAD.
1383 */
1384 nd6_dad_ns_output(dp, ifa);
1385 nd6_dad_starttimer(dp,
1386 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1387 } else {
1388 /*
1389 * We have transmitted sufficient number of DAD packets.
1390 * See what we've got.
1391 */
1392 int duplicate;
1393
1394 duplicate = 0;
1395
1396 if (dp->dad_na_icount) {
1397 /*
1398 * the check is in nd6_dad_na_input(),
1399 * but just in case
1400 */
1401 duplicate++;
1402 }
1403
1404 if (dp->dad_ns_icount) {
1405 /* We've seen NS, means DAD has failed. */
1406 duplicate++;
1407 }
1408
1409 if (duplicate) {
1410 /* (*dp) will be freed in nd6_dad_duplicated() */
1411 dp = NULL;
1412 nd6_dad_duplicated(ifa);
1413 } else {
1414 /*
1415 * We are done with DAD. No NA came, no NS came.
1416 * No duplicate address found. Check IFDISABLED flag
1417 * again in case that it is changed between the
1418 * beginning of this function and here.
1419 */
1420 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
1421 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1422
1423 nd6log((LOG_DEBUG,
1424 "%s: DAD complete for %s - no duplicates found\n",
1425 if_name(ifa->ifa_ifp),
1426 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1427
1428 DADQ_WLOCK();
1429 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1430 DADQ_WUNLOCK();
1431 free(dp, M_IP6NDP);
1432 dp = NULL;
1433 ifa_free(ifa);
1434 }
1435 }
1436
1437 done:
1438 CURVNET_RESTORE();
1439 }
1440
1441 void
1442 nd6_dad_duplicated(struct ifaddr *ifa)
1443 {
1444 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1445 struct ifnet *ifp;
1446 struct dadq *dp;
1447 char ip6buf[INET6_ADDRSTRLEN];
1448
1449 dp = nd6_dad_find(ifa);
1450 if (dp == NULL) {
1451 log(LOG_ERR, "nd6_dad_duplicated: DAD structure not found\n");
1452 return;
1453 }
1454
1455 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1456 "NS in/out=%d/%d, NA in=%d\n",
1457 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1458 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
1459
1460 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1461 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1462
1463 /* We are done with DAD, with duplicate address found. (failure) */
1464 nd6_dad_stoptimer(dp);
1465
1466 ifp = ifa->ifa_ifp;
1467 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1468 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1469 log(LOG_ERR, "%s: manual intervention required\n",
1470 if_name(ifp));
1471
1472 /*
1473 * If the address is a link-local address formed from an interface
1474 * identifier based on the hardware address which is supposed to be
1475 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1476 * operation on the interface SHOULD be disabled.
1477 * [RFC 4862, Section 5.4.5]
1478 */
1479 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1480 struct in6_addr in6;
1481
1482 /*
1483 * To avoid over-reaction, we only apply this logic when we are
1484 * very sure that hardware addresses are supposed to be unique.
1485 */
1486 switch (ifp->if_type) {
1487 case IFT_ETHER:
1488 case IFT_FDDI:
1489 case IFT_ATM:
1490 case IFT_IEEE1394:
1491 #ifdef IFT_IEEE80211
1492 case IFT_IEEE80211:
1493 #endif
1494 case IFT_INFINIBAND:
1495 in6 = ia->ia_addr.sin6_addr;
1496 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1497 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1498 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1499 log(LOG_ERR, "%s: possible hardware address "
1500 "duplication detected, disable IPv6\n",
1501 if_name(ifp));
1502 }
1503 break;
1504 }
1505 }
1506
1507 DADQ_WLOCK();
1508 TAILQ_REMOVE(&V_dadq, (struct dadq *)dp, dad_list);
1509 DADQ_WUNLOCK();
1510 free(dp, M_IP6NDP);
1511 dp = NULL;
1512 ifa_free(ifa);
1513 }
1514
1515 static void
1516 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
1517 {
1518 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1519 struct ifnet *ifp = ifa->ifa_ifp;
1520
1521 dp->dad_ns_tcount++;
1522 if ((ifp->if_flags & IFF_UP) == 0) {
1523 return;
1524 }
1525 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1526 return;
1527 }
1528
1529 dp->dad_ns_ocount++;
1530 nd6_ns_output(ifp, NULL, &ia->ia_addr.sin6_addr, NULL, 1);
1531 }
1532
1533 static void
1534 nd6_dad_ns_input(struct ifaddr *ifa)
1535 {
1536 struct in6_ifaddr *ia;
1537 struct ifnet *ifp;
1538 const struct in6_addr *taddr6;
1539 struct dadq *dp;
1540 int duplicate;
1541
1542 if (ifa == NULL)
1543 panic("ifa == NULL in nd6_dad_ns_input");
1544
1545 ia = (struct in6_ifaddr *)ifa;
1546 ifp = ifa->ifa_ifp;
1547 taddr6 = &ia->ia_addr.sin6_addr;
1548 duplicate = 0;
1549 dp = nd6_dad_find(ifa);
1550
1551 /* Quickhack - completely ignore DAD NS packets */
1552 if (V_dad_ignore_ns) {
1553 char ip6buf[INET6_ADDRSTRLEN];
1554 nd6log((LOG_INFO,
1555 "nd6_dad_ns_input: ignoring DAD NS packet for "
1556 "address %s(%s)\n", ip6_sprintf(ip6buf, taddr6),
1557 if_name(ifa->ifa_ifp)));
1558 return;
1559 }
1560
1561 /*
1562 * if I'm yet to start DAD, someone else started using this address
1563 * first. I have a duplicate and you win.
1564 */
1565 if (dp == NULL || dp->dad_ns_ocount == 0)
1566 duplicate++;
1567
1568 /* XXX more checks for loopback situation - see nd6_dad_timer too */
1569
1570 if (duplicate) {
1571 dp = NULL; /* will be freed in nd6_dad_duplicated() */
1572 nd6_dad_duplicated(ifa);
1573 } else {
1574 /*
1575 * not sure if I got a duplicate.
1576 * increment ns count and see what happens.
1577 */
1578 if (dp)
1579 dp->dad_ns_icount++;
1580 }
1581 }
1582
1583 static void
1584 nd6_dad_na_input(struct ifaddr *ifa)
1585 {
1586 struct dadq *dp;
1587
1588 if (ifa == NULL)
1589 panic("ifa == NULL in nd6_dad_na_input");
1590
1591 dp = nd6_dad_find(ifa);
1592 if (dp)
1593 dp->dad_na_icount++;
1594
1595 /* remove the address. */
1596 nd6_dad_duplicated(ifa);
1597 }
Cache object: db09d959eb1fd4559c3cc57142a64170
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