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/11.0/sys/netinet6/nd6_nbr.c 301213 2016-06-02 17:17:15Z markj $");
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/libkern.h>
44 #include <sys/lock.h>
45 #include <sys/rwlock.h>
46 #include <sys/mbuf.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/errno.h>
52 #include <sys/sysctl.h>
53 #include <sys/syslog.h>
54 #include <sys/queue.h>
55 #include <sys/callout.h>
56 #include <sys/refcount.h>
57
58 #include <net/if.h>
59 #include <net/if_types.h>
60 #include <net/if_dl.h>
61 #include <net/if_var.h>
62 #include <net/route.h>
63 #ifdef RADIX_MPATH
64 #include <net/radix_mpath.h>
65 #endif
66 #include <net/vnet.h>
67
68 #include <netinet/in.h>
69 #include <netinet/in_var.h>
70 #include <net/if_llatbl.h>
71 #include <netinet6/in6_var.h>
72 #include <netinet6/in6_ifattach.h>
73 #include <netinet/ip6.h>
74 #include <netinet6/ip6_var.h>
75 #include <netinet6/scope6_var.h>
76 #include <netinet6/nd6.h>
77 #include <netinet/icmp6.h>
78 #include <netinet/ip_carp.h>
79 #include <netinet6/send.h>
80
81 #define SDL(s) ((struct sockaddr_dl *)s)
82
83 struct dadq;
84 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *);
85 static void nd6_dad_add(struct dadq *dp);
86 static void nd6_dad_del(struct dadq *dp);
87 static void nd6_dad_rele(struct dadq *);
88 static void nd6_dad_starttimer(struct dadq *, int, int);
89 static void nd6_dad_stoptimer(struct dadq *);
90 static void nd6_dad_timer(struct dadq *);
91 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *);
92 static void nd6_dad_ns_output(struct dadq *);
93 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *);
94 static void nd6_dad_na_input(struct ifaddr *);
95 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
96 const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
97 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *,
98 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int);
99
100 static VNET_DEFINE(int, dad_enhanced) = 1;
101 #define V_dad_enhanced VNET(dad_enhanced)
102
103 SYSCTL_DECL(_net_inet6_ip6);
104 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
105 &VNET_NAME(dad_enhanced), 0,
106 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
107
108 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to
109 transmit DAD packet */
110 #define V_dad_maxtry VNET(dad_maxtry)
111
112 /*
113 * Input a Neighbor Solicitation Message.
114 *
115 * Based on RFC 2461
116 * Based on RFC 2462 (duplicate address detection)
117 */
118 void
119 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
120 {
121 struct ifnet *ifp = m->m_pkthdr.rcvif;
122 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
123 struct nd_neighbor_solicit *nd_ns;
124 struct in6_addr saddr6 = ip6->ip6_src;
125 struct in6_addr daddr6 = ip6->ip6_dst;
126 struct in6_addr taddr6;
127 struct in6_addr myaddr6;
128 char *lladdr = NULL;
129 struct ifaddr *ifa = NULL;
130 int lladdrlen = 0;
131 int anycast = 0, proxy = 0, tentative = 0;
132 int tlladdr;
133 int rflag;
134 union nd_opts ndopts;
135 struct sockaddr_dl proxydl;
136 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
137
138 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
139 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
140 rflag = 0;
141 #ifndef PULLDOWN_TEST
142 IP6_EXTHDR_CHECK(m, off, icmp6len,);
143 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
144 #else
145 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
146 if (nd_ns == NULL) {
147 ICMP6STAT_INC(icp6s_tooshort);
148 return;
149 }
150 #endif
151 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
152 taddr6 = nd_ns->nd_ns_target;
153 if (in6_setscope(&taddr6, ifp, NULL) != 0)
154 goto bad;
155
156 if (ip6->ip6_hlim != 255) {
157 nd6log((LOG_ERR,
158 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
159 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
160 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
161 goto bad;
162 }
163
164 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
165 /* dst has to be a solicited node multicast address. */
166 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
167 /* don't check ifindex portion */
168 daddr6.s6_addr32[1] == 0 &&
169 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
170 daddr6.s6_addr8[12] == 0xff) {
171 ; /* good */
172 } else {
173 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
174 "(wrong ip6 dst)\n"));
175 goto bad;
176 }
177 } else if (!V_nd6_onlink_ns_rfc4861) {
178 struct sockaddr_in6 src_sa6;
179
180 /*
181 * According to recent IETF discussions, it is not a good idea
182 * to accept a NS from an address which would not be deemed
183 * to be a neighbor otherwise. This point is expected to be
184 * clarified in future revisions of the specification.
185 */
186 bzero(&src_sa6, sizeof(src_sa6));
187 src_sa6.sin6_family = AF_INET6;
188 src_sa6.sin6_len = sizeof(src_sa6);
189 src_sa6.sin6_addr = saddr6;
190 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
191 nd6log((LOG_INFO, "nd6_ns_input: "
192 "NS packet from non-neighbor\n"));
193 goto bad;
194 }
195 }
196
197 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
198 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
199 goto bad;
200 }
201
202 icmp6len -= sizeof(*nd_ns);
203 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
204 if (nd6_options(&ndopts) < 0) {
205 nd6log((LOG_INFO,
206 "nd6_ns_input: invalid ND option, ignored\n"));
207 /* nd6_options have incremented stats */
208 goto freeit;
209 }
210
211 if (ndopts.nd_opts_src_lladdr) {
212 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
213 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
214 }
215
216 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
217 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
218 "(link-layer address option)\n"));
219 goto bad;
220 }
221
222 /*
223 * Attaching target link-layer address to the NA?
224 * (RFC 2461 7.2.4)
225 *
226 * NS IP dst is unicast/anycast MUST NOT add
227 * NS IP dst is solicited-node multicast MUST add
228 *
229 * In implementation, we add target link-layer address by default.
230 * We do not add one in MUST NOT cases.
231 */
232 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
233 tlladdr = 0;
234 else
235 tlladdr = 1;
236
237 /*
238 * Target address (taddr6) must be either:
239 * (1) Valid unicast/anycast address for my receiving interface,
240 * (2) Unicast address for which I'm offering proxy service, or
241 * (3) "tentative" address on which DAD is being performed.
242 */
243 /* (1) and (3) check. */
244 if (ifp->if_carp)
245 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
246 else
247 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
248
249 /* (2) check. */
250 if (ifa == NULL) {
251 struct sockaddr_dl rt_gateway;
252 struct rt_addrinfo info;
253 struct sockaddr_in6 dst6;
254
255 bzero(&dst6, sizeof(dst6));
256 dst6.sin6_len = sizeof(struct sockaddr_in6);
257 dst6.sin6_family = AF_INET6;
258 dst6.sin6_addr = taddr6;
259
260 bzero(&rt_gateway, sizeof(rt_gateway));
261 rt_gateway.sdl_len = sizeof(rt_gateway);
262 bzero(&info, sizeof(info));
263 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
264
265 /* Always use the default FIB. */
266 if (rib_lookup_info(RT_DEFAULT_FIB, (struct sockaddr *)&dst6,
267 0, 0, &info) == 0) {
268 if ((info.rti_flags & RTF_ANNOUNCE) != 0 &&
269 rt_gateway.sdl_family == AF_LINK) {
270
271 /*
272 * proxy NDP for single entry
273 */
274 proxydl = *SDL(&rt_gateway);
275 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(
276 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
277 if (ifa)
278 proxy = 1;
279 }
280 }
281 }
282 if (ifa == NULL) {
283 /*
284 * We've got an NS packet, and we don't have that adddress
285 * assigned for us. We MUST silently ignore it.
286 * See RFC2461 7.2.3.
287 */
288 goto freeit;
289 }
290 myaddr6 = *IFA_IN6(ifa);
291 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
292 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
293 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
294 goto freeit;
295
296 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
297 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
298 "(if %d, NS packet %d)\n",
299 ip6_sprintf(ip6bufs, &taddr6),
300 ifp->if_addrlen, lladdrlen - 2));
301 goto bad;
302 }
303
304 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
305 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
306 ip6_sprintf(ip6bufs, &saddr6)));
307 goto freeit;
308 }
309
310 /*
311 * We have neighbor solicitation packet, with target address equals to
312 * one of my tentative address.
313 *
314 * src addr how to process?
315 * --- ---
316 * multicast of course, invalid (rejected in ip6_input)
317 * unicast somebody is doing address resolution -> ignore
318 * unspec dup address detection
319 *
320 * The processing is defined in RFC 2462.
321 */
322 if (tentative) {
323 /*
324 * If source address is unspecified address, it is for
325 * duplicate address detection.
326 *
327 * If not, the packet is for addess resolution;
328 * silently ignore it.
329 */
330 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
331 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
332
333 goto freeit;
334 }
335
336 /*
337 * If the source address is unspecified address, entries must not
338 * be created or updated.
339 * It looks that sender is performing DAD. Output NA toward
340 * all-node multicast address, to tell the sender that I'm using
341 * the address.
342 * S bit ("solicited") must be zero.
343 */
344 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
345 struct in6_addr in6_all;
346
347 in6_all = in6addr_linklocal_allnodes;
348 if (in6_setscope(&in6_all, ifp, NULL) != 0)
349 goto bad;
350 nd6_na_output_fib(ifp, &in6_all, &taddr6,
351 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
352 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
353 M_GETFIB(m));
354 goto freeit;
355 }
356
357 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
358 ND_NEIGHBOR_SOLICIT, 0);
359
360 nd6_na_output_fib(ifp, &saddr6, &taddr6,
361 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
362 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
363 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
364 freeit:
365 if (ifa != NULL)
366 ifa_free(ifa);
367 m_freem(m);
368 return;
369
370 bad:
371 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
372 ip6_sprintf(ip6bufs, &saddr6)));
373 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
374 ip6_sprintf(ip6bufs, &daddr6)));
375 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
376 ip6_sprintf(ip6bufs, &taddr6)));
377 ICMP6STAT_INC(icp6s_badns);
378 if (ifa != NULL)
379 ifa_free(ifa);
380 m_freem(m);
381 }
382
383 /*
384 * Output a Neighbor Solicitation Message. Caller specifies:
385 * - ICMP6 header source IP6 address
386 * - ND6 header target IP6 address
387 * - ND6 header source datalink address
388 *
389 * Based on RFC 2461
390 * Based on RFC 2462 (duplicate address detection)
391 *
392 * ln - for source address determination
393 * nonce - If non-NULL, NS is used for duplicate address detection and
394 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
395 */
396 static void
397 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
398 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
399 uint8_t *nonce, u_int fibnum)
400 {
401 struct mbuf *m;
402 struct m_tag *mtag;
403 struct ip6_hdr *ip6;
404 struct nd_neighbor_solicit *nd_ns;
405 struct ip6_moptions im6o;
406 int icmp6len;
407 int maxlen;
408 caddr_t mac;
409
410 if (IN6_IS_ADDR_MULTICAST(taddr6))
411 return;
412
413 /* estimate the size of message */
414 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
415 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
416 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
417 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
418 __func__, max_linkhdr, maxlen, MCLBYTES));
419
420 if (max_linkhdr + maxlen > MHLEN)
421 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
422 else
423 m = m_gethdr(M_NOWAIT, MT_DATA);
424 if (m == NULL)
425 return;
426 M_SETFIB(m, fibnum);
427
428 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
429 m->m_flags |= M_MCAST;
430 im6o.im6o_multicast_ifp = ifp;
431 im6o.im6o_multicast_hlim = 255;
432 im6o.im6o_multicast_loop = 0;
433 }
434
435 icmp6len = sizeof(*nd_ns);
436 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
437 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
438
439 /* fill neighbor solicitation packet */
440 ip6 = mtod(m, struct ip6_hdr *);
441 ip6->ip6_flow = 0;
442 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
443 ip6->ip6_vfc |= IPV6_VERSION;
444 /* ip6->ip6_plen will be set later */
445 ip6->ip6_nxt = IPPROTO_ICMPV6;
446 ip6->ip6_hlim = 255;
447 if (daddr6)
448 ip6->ip6_dst = *daddr6;
449 else {
450 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
451 ip6->ip6_dst.s6_addr16[1] = 0;
452 ip6->ip6_dst.s6_addr32[1] = 0;
453 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
454 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
455 ip6->ip6_dst.s6_addr8[12] = 0xff;
456 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
457 goto bad;
458 }
459 if (nonce == NULL) {
460 struct ifaddr *ifa = NULL;
461
462 /*
463 * RFC2461 7.2.2:
464 * "If the source address of the packet prompting the
465 * solicitation is the same as one of the addresses assigned
466 * to the outgoing interface, that address SHOULD be placed
467 * in the IP Source Address of the outgoing solicitation.
468 * Otherwise, any one of the addresses assigned to the
469 * interface should be used."
470 *
471 * We use the source address for the prompting packet
472 * (saddr6), if saddr6 belongs to the outgoing interface.
473 * Otherwise, we perform the source address selection as usual.
474 */
475
476 if (saddr6 != NULL)
477 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
478 if (ifa != NULL) {
479 /* ip6_src set already. */
480 ip6->ip6_src = *saddr6;
481 ifa_free(ifa);
482 } else {
483 int error;
484 struct in6_addr dst6, src6;
485 uint32_t scopeid;
486
487 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
488 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6,
489 scopeid, ifp, &src6, NULL);
490 if (error) {
491 char ip6buf[INET6_ADDRSTRLEN];
492 nd6log((LOG_DEBUG, "%s: source can't be "
493 "determined: dst=%s, error=%d\n", __func__,
494 ip6_sprintf(ip6buf, &dst6),
495 error));
496 goto bad;
497 }
498 ip6->ip6_src = src6;
499 }
500 } else {
501 /*
502 * Source address for DAD packet must always be IPv6
503 * unspecified address. (0::0)
504 * We actually don't have to 0-clear the address (we did it
505 * above), but we do so here explicitly to make the intention
506 * clearer.
507 */
508 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
509 }
510 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
511 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
512 nd_ns->nd_ns_code = 0;
513 nd_ns->nd_ns_reserved = 0;
514 nd_ns->nd_ns_target = *taddr6;
515 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
516
517 /*
518 * Add source link-layer address option.
519 *
520 * spec implementation
521 * --- ---
522 * DAD packet MUST NOT do not add the option
523 * there's no link layer address:
524 * impossible do not add the option
525 * there's link layer address:
526 * Multicast NS MUST add one add the option
527 * Unicast NS SHOULD add one add the option
528 */
529 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) {
530 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
531 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
532 /* 8 byte alignments... */
533 optlen = (optlen + 7) & ~7;
534
535 m->m_pkthdr.len += optlen;
536 m->m_len += optlen;
537 icmp6len += optlen;
538 bzero((caddr_t)nd_opt, optlen);
539 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
540 nd_opt->nd_opt_len = optlen >> 3;
541 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
542 }
543 /*
544 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
545 * This behavior is documented as Enhanced Duplicate Address
546 * Detection in RFC 7527.
547 * net.inet6.ip6.dad_enhanced=0 disables this.
548 */
549 if (V_dad_enhanced != 0 && nonce != NULL) {
550 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
551 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
552 /* 8-byte alignment is required. */
553 optlen = (optlen + 7) & ~7;
554
555 m->m_pkthdr.len += optlen;
556 m->m_len += optlen;
557 icmp6len += optlen;
558 bzero((caddr_t)nd_opt, optlen);
559 nd_opt->nd_opt_type = ND_OPT_NONCE;
560 nd_opt->nd_opt_len = optlen >> 3;
561 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
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, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
578 &im6o, NULL, NULL);
579 icmp6_ifstat_inc(ifp, ifs6_out_msg);
580 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
581 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
582
583 return;
584
585 bad:
586 m_freem(m);
587 }
588
589 #ifndef BURN_BRIDGES
590 void
591 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
592 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
593 {
594
595 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
596 }
597 #endif
598 /*
599 * Neighbor advertisement input handling.
600 *
601 * Based on RFC 2461
602 * Based on RFC 2462 (duplicate address detection)
603 *
604 * the following items are not implemented yet:
605 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
606 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
607 */
608 void
609 nd6_na_input(struct mbuf *m, int off, int icmp6len)
610 {
611 struct ifnet *ifp = m->m_pkthdr.rcvif;
612 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
613 struct nd_neighbor_advert *nd_na;
614 struct in6_addr daddr6 = ip6->ip6_dst;
615 struct in6_addr taddr6;
616 int flags;
617 int is_router;
618 int is_solicited;
619 int is_override;
620 char *lladdr = NULL;
621 int lladdrlen = 0;
622 int checklink = 0;
623 struct ifaddr *ifa;
624 struct llentry *ln = NULL;
625 union nd_opts ndopts;
626 struct mbuf *chain = NULL;
627 struct sockaddr_in6 sin6;
628 u_char linkhdr[LLE_MAX_LINKHDR];
629 size_t linkhdrsize;
630 int lladdr_off;
631 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
632
633 if (ip6->ip6_hlim != 255) {
634 nd6log((LOG_ERR,
635 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
636 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
637 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
638 goto bad;
639 }
640
641 #ifndef PULLDOWN_TEST
642 IP6_EXTHDR_CHECK(m, off, icmp6len,);
643 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
644 #else
645 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
646 if (nd_na == NULL) {
647 ICMP6STAT_INC(icp6s_tooshort);
648 return;
649 }
650 #endif
651
652 flags = nd_na->nd_na_flags_reserved;
653 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
654 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
655 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
656 memset(&sin6, 0, sizeof(sin6));
657
658 taddr6 = nd_na->nd_na_target;
659 if (in6_setscope(&taddr6, ifp, NULL))
660 goto bad; /* XXX: impossible */
661
662 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
663 nd6log((LOG_ERR,
664 "nd6_na_input: invalid target address %s\n",
665 ip6_sprintf(ip6bufs, &taddr6)));
666 goto bad;
667 }
668 if (IN6_IS_ADDR_MULTICAST(&daddr6))
669 if (is_solicited) {
670 nd6log((LOG_ERR,
671 "nd6_na_input: a solicited adv is multicasted\n"));
672 goto bad;
673 }
674
675 icmp6len -= sizeof(*nd_na);
676 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
677 if (nd6_options(&ndopts) < 0) {
678 nd6log((LOG_INFO,
679 "nd6_na_input: invalid ND option, ignored\n"));
680 /* nd6_options have incremented stats */
681 goto freeit;
682 }
683
684 if (ndopts.nd_opts_tgt_lladdr) {
685 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
686 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
687 }
688
689 /*
690 * This effectively disables the DAD check on a non-master CARP
691 * address.
692 */
693 if (ifp->if_carp)
694 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
695 else
696 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
697
698 /*
699 * Target address matches one of my interface address.
700 *
701 * If my address is tentative, this means that there's somebody
702 * already using the same address as mine. This indicates DAD failure.
703 * This is defined in RFC 2462.
704 *
705 * Otherwise, process as defined in RFC 2461.
706 */
707 if (ifa
708 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
709 nd6_dad_na_input(ifa);
710 ifa_free(ifa);
711 goto freeit;
712 }
713
714 /* Just for safety, maybe unnecessary. */
715 if (ifa) {
716 ifa_free(ifa);
717 log(LOG_ERR,
718 "nd6_na_input: duplicate IP6 address %s\n",
719 ip6_sprintf(ip6bufs, &taddr6));
720 goto freeit;
721 }
722
723 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
724 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
725 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
726 ifp->if_addrlen, lladdrlen - 2));
727 goto bad;
728 }
729
730 /*
731 * If no neighbor cache entry is found, NA SHOULD silently be
732 * discarded.
733 */
734 IF_AFDATA_RLOCK(ifp);
735 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
736 IF_AFDATA_RUNLOCK(ifp);
737 if (ln == NULL) {
738 goto freeit;
739 }
740
741 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
742 /*
743 * If the link-layer has address, and no lladdr option came,
744 * discard the packet.
745 */
746 if (ifp->if_addrlen && lladdr == NULL) {
747 goto freeit;
748 }
749
750 /*
751 * Record link-layer address, and update the state.
752 */
753 linkhdrsize = sizeof(linkhdr);
754 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
755 linkhdr, &linkhdrsize, &lladdr_off) != 0)
756 return;
757
758 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
759 lladdr_off) == 0) {
760 ln = NULL;
761 goto freeit;
762 }
763 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
764 if (is_solicited)
765 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
766 else
767 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
768 if ((ln->ln_router = is_router) != 0) {
769 /*
770 * This means a router's state has changed from
771 * non-reachable to probably reachable, and might
772 * affect the status of associated prefixes..
773 */
774 checklink = 1;
775 }
776 } else {
777 int llchange;
778
779 /*
780 * Check if the link-layer address has changed or not.
781 */
782 if (lladdr == NULL)
783 llchange = 0;
784 else {
785 if (ln->la_flags & LLE_VALID) {
786 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
787 llchange = 1;
788 else
789 llchange = 0;
790 } else
791 llchange = 1;
792 }
793
794 /*
795 * This is VERY complex. Look at it with care.
796 *
797 * override solicit lladdr llchange action
798 * (L: record lladdr)
799 *
800 * 0 0 n -- (2c)
801 * 0 0 y n (2b) L
802 * 0 0 y y (1) REACHABLE->STALE
803 * 0 1 n -- (2c) *->REACHABLE
804 * 0 1 y n (2b) L *->REACHABLE
805 * 0 1 y y (1) REACHABLE->STALE
806 * 1 0 n -- (2a)
807 * 1 0 y n (2a) L
808 * 1 0 y y (2a) L *->STALE
809 * 1 1 n -- (2a) *->REACHABLE
810 * 1 1 y n (2a) L *->REACHABLE
811 * 1 1 y y (2a) L *->REACHABLE
812 */
813 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
814 /*
815 * If state is REACHABLE, make it STALE.
816 * no other updates should be done.
817 */
818 if (ln->ln_state == ND6_LLINFO_REACHABLE)
819 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
820 goto freeit;
821 } else if (is_override /* (2a) */
822 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
823 || lladdr == NULL) { /* (2c) */
824 /*
825 * Update link-local address, if any.
826 */
827 if (lladdr != NULL) {
828 linkhdrsize = sizeof(linkhdr);
829 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
830 linkhdr, &linkhdrsize, &lladdr_off) != 0)
831 goto freeit;
832 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
833 linkhdrsize, lladdr_off) == 0) {
834 ln = NULL;
835 goto freeit;
836 }
837 EVENTHANDLER_INVOKE(lle_event, ln,
838 LLENTRY_RESOLVED);
839 }
840
841 /*
842 * If solicited, make the state REACHABLE.
843 * If not solicited and the link-layer address was
844 * changed, make it STALE.
845 */
846 if (is_solicited)
847 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
848 else {
849 if (lladdr != NULL && llchange)
850 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
851 }
852 }
853
854 if (ln->ln_router && !is_router) {
855 /*
856 * The peer dropped the router flag.
857 * Remove the sender from the Default Router List and
858 * update the Destination Cache entries.
859 */
860 struct ifnet *nd6_ifp;
861
862 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
863 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
864 (ND_IFINFO(nd6_ifp)->flags &
865 ND6_IFF_ACCEPT_RTADV) != 0)
866 /*
867 * Even if the neighbor is not in the default
868 * router list, the neighbor may be used as a
869 * next hop for some destinations (e.g. redirect
870 * case). So we must call rt6_flush explicitly.
871 */
872 rt6_flush(&ip6->ip6_src, ifp);
873 }
874 ln->ln_router = is_router;
875 }
876 /* XXX - QL
877 * Does this matter?
878 * rt->rt_flags &= ~RTF_REJECT;
879 */
880 ln->la_asked = 0;
881 if (ln->la_hold != NULL)
882 nd6_grab_holdchain(ln, &chain, &sin6);
883 freeit:
884 if (ln != NULL)
885 LLE_WUNLOCK(ln);
886
887 if (chain != NULL)
888 nd6_flush_holdchain(ifp, ifp, chain, &sin6);
889
890 if (checklink)
891 pfxlist_onlink_check();
892
893 m_freem(m);
894 return;
895
896 bad:
897 if (ln != NULL)
898 LLE_WUNLOCK(ln);
899
900 ICMP6STAT_INC(icp6s_badna);
901 m_freem(m);
902 }
903
904 /*
905 * Neighbor advertisement output handling.
906 *
907 * Based on RFC 2461
908 *
909 * the following items are not implemented yet:
910 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
911 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
912 *
913 * tlladdr - 1 if include target link-layer address
914 * sdl0 - sockaddr_dl (= proxy NA) or NULL
915 */
916 static void
917 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
918 const struct in6_addr *taddr6, u_long flags, int tlladdr,
919 struct sockaddr *sdl0, u_int fibnum)
920 {
921 struct mbuf *m;
922 struct m_tag *mtag;
923 struct ip6_hdr *ip6;
924 struct nd_neighbor_advert *nd_na;
925 struct ip6_moptions im6o;
926 struct in6_addr daddr6, dst6, src6;
927 uint32_t scopeid;
928
929 int icmp6len, maxlen, error;
930 caddr_t mac = NULL;
931
932 daddr6 = *daddr6_0; /* make a local copy for modification */
933
934 /* estimate the size of message */
935 maxlen = sizeof(*ip6) + sizeof(*nd_na);
936 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
937 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
938 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
939 __func__, max_linkhdr, maxlen, MCLBYTES));
940
941 if (max_linkhdr + maxlen > MHLEN)
942 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
943 else
944 m = m_gethdr(M_NOWAIT, MT_DATA);
945 if (m == NULL)
946 return;
947 M_SETFIB(m, fibnum);
948
949 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
950 m->m_flags |= M_MCAST;
951 im6o.im6o_multicast_ifp = ifp;
952 im6o.im6o_multicast_hlim = 255;
953 im6o.im6o_multicast_loop = 0;
954 }
955
956 icmp6len = sizeof(*nd_na);
957 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
958 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
959
960 /* fill neighbor advertisement packet */
961 ip6 = mtod(m, struct ip6_hdr *);
962 ip6->ip6_flow = 0;
963 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
964 ip6->ip6_vfc |= IPV6_VERSION;
965 ip6->ip6_nxt = IPPROTO_ICMPV6;
966 ip6->ip6_hlim = 255;
967 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
968 /* reply to DAD */
969 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
970 daddr6.s6_addr16[1] = 0;
971 daddr6.s6_addr32[1] = 0;
972 daddr6.s6_addr32[2] = 0;
973 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
974 if (in6_setscope(&daddr6, ifp, NULL))
975 goto bad;
976
977 flags &= ~ND_NA_FLAG_SOLICITED;
978 }
979 ip6->ip6_dst = daddr6;
980
981 /*
982 * Select a source whose scope is the same as that of the dest.
983 */
984 in6_splitscope(&daddr6, &dst6, &scopeid);
985 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6,
986 scopeid, ifp, &src6, NULL);
987 if (error) {
988 char ip6buf[INET6_ADDRSTRLEN];
989 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
990 "determined: dst=%s, error=%d\n",
991 ip6_sprintf(ip6buf, &daddr6), error));
992 goto bad;
993 }
994 ip6->ip6_src = src6;
995 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
996 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
997 nd_na->nd_na_code = 0;
998 nd_na->nd_na_target = *taddr6;
999 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1000
1001 /*
1002 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1003 * see nd6_ns_input() for details.
1004 * Basically, if NS packet is sent to unicast/anycast addr,
1005 * target lladdr option SHOULD NOT be included.
1006 */
1007 if (tlladdr) {
1008 /*
1009 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1010 * lladdr in sdl0. If we are not proxying (sending NA for
1011 * my address) use lladdr configured for the interface.
1012 */
1013 if (sdl0 == NULL) {
1014 if (ifp->if_carp)
1015 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1016 if (mac == NULL)
1017 mac = nd6_ifptomac(ifp);
1018 } else if (sdl0->sa_family == AF_LINK) {
1019 struct sockaddr_dl *sdl;
1020 sdl = (struct sockaddr_dl *)sdl0;
1021 if (sdl->sdl_alen == ifp->if_addrlen)
1022 mac = LLADDR(sdl);
1023 }
1024 }
1025 if (tlladdr && mac) {
1026 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1027 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1028
1029 /* roundup to 8 bytes alignment! */
1030 optlen = (optlen + 7) & ~7;
1031
1032 m->m_pkthdr.len += optlen;
1033 m->m_len += optlen;
1034 icmp6len += optlen;
1035 bzero((caddr_t)nd_opt, optlen);
1036 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1037 nd_opt->nd_opt_len = optlen >> 3;
1038 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1039 } else
1040 flags &= ~ND_NA_FLAG_OVERRIDE;
1041
1042 ip6->ip6_plen = htons((u_short)icmp6len);
1043 nd_na->nd_na_flags_reserved = flags;
1044 nd_na->nd_na_cksum = 0;
1045 nd_na->nd_na_cksum =
1046 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1047
1048 if (send_sendso_input_hook != NULL) {
1049 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1050 sizeof(unsigned short), M_NOWAIT);
1051 if (mtag == NULL)
1052 goto bad;
1053 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1054 m_tag_prepend(m, mtag);
1055 }
1056
1057 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1058 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1059 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1060 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1061
1062 return;
1063
1064 bad:
1065 m_freem(m);
1066 }
1067
1068 #ifndef BURN_BRIDGES
1069 void
1070 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1071 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1072 struct sockaddr *sdl0)
1073 {
1074
1075 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1076 RT_DEFAULT_FIB);
1077 }
1078 #endif
1079
1080 caddr_t
1081 nd6_ifptomac(struct ifnet *ifp)
1082 {
1083 switch (ifp->if_type) {
1084 case IFT_ARCNET:
1085 case IFT_ETHER:
1086 case IFT_FDDI:
1087 case IFT_IEEE1394:
1088 case IFT_L2VLAN:
1089 case IFT_IEEE80211:
1090 case IFT_INFINIBAND:
1091 case IFT_BRIDGE:
1092 case IFT_ISO88025:
1093 return IF_LLADDR(ifp);
1094 default:
1095 return NULL;
1096 }
1097 }
1098
1099 struct dadq {
1100 TAILQ_ENTRY(dadq) dad_list;
1101 struct ifaddr *dad_ifa;
1102 int dad_count; /* max NS to send */
1103 int dad_ns_tcount; /* # of trials to send NS */
1104 int dad_ns_ocount; /* NS sent so far */
1105 int dad_ns_icount;
1106 int dad_na_icount;
1107 int dad_ns_lcount; /* looped back NS */
1108 int dad_loopbackprobe; /* probing state for loopback detection */
1109 struct callout dad_timer_ch;
1110 struct vnet *dad_vnet;
1111 u_int dad_refcnt;
1112 #define ND_OPT_NONCE_LEN32 \
1113 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1114 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1115 };
1116
1117 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
1118 static VNET_DEFINE(struct rwlock, dad_rwlock);
1119 #define V_dadq VNET(dadq)
1120 #define V_dad_rwlock VNET(dad_rwlock)
1121
1122 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock)
1123 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock)
1124 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock)
1125 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock)
1126
1127 static void
1128 nd6_dad_add(struct dadq *dp)
1129 {
1130
1131 DADQ_WLOCK();
1132 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1133 DADQ_WUNLOCK();
1134 }
1135
1136 static void
1137 nd6_dad_del(struct dadq *dp)
1138 {
1139
1140 DADQ_WLOCK();
1141 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1142 DADQ_WUNLOCK();
1143 nd6_dad_rele(dp);
1144 }
1145
1146 static struct dadq *
1147 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
1148 {
1149 struct dadq *dp;
1150
1151 DADQ_RLOCK();
1152 TAILQ_FOREACH(dp, &V_dadq, dad_list) {
1153 if (dp->dad_ifa != ifa)
1154 continue;
1155 /*
1156 * Skip if the nonce matches the received one.
1157 * +2 in the length is required because of type and
1158 * length fields are included in a header.
1159 */
1160 if (n != NULL &&
1161 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
1162 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
1163 ND_OPT_NONCE_LEN) == 0) {
1164 dp->dad_ns_lcount++;
1165 continue;
1166 }
1167 refcount_acquire(&dp->dad_refcnt);
1168 break;
1169 }
1170 DADQ_RUNLOCK();
1171
1172 return (dp);
1173 }
1174
1175 static void
1176 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns)
1177 {
1178
1179 if (send_ns != 0)
1180 nd6_dad_ns_output(dp);
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_drain(&dp->dad_timer_ch);
1190 }
1191
1192 static void
1193 nd6_dad_rele(struct dadq *dp)
1194 {
1195
1196 if (refcount_release(&dp->dad_refcnt)) {
1197 ifa_free(dp->dad_ifa);
1198 free(dp, M_IP6NDP);
1199 }
1200 }
1201
1202 void
1203 nd6_dad_init(void)
1204 {
1205
1206 rw_init(&V_dad_rwlock, "nd6 DAD queue");
1207 TAILQ_INIT(&V_dadq);
1208 }
1209
1210 /*
1211 * Start Duplicate Address Detection (DAD) for specified interface address.
1212 */
1213 void
1214 nd6_dad_start(struct ifaddr *ifa, int delay)
1215 {
1216 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1217 struct dadq *dp;
1218 char ip6buf[INET6_ADDRSTRLEN];
1219
1220 /*
1221 * If we don't need DAD, don't do it.
1222 * There are several cases:
1223 * - DAD is disabled (ip6_dad_count == 0)
1224 * - the interface address is anycast
1225 */
1226 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1227 log(LOG_DEBUG,
1228 "nd6_dad_start: called with non-tentative address "
1229 "%s(%s)\n",
1230 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1231 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1232 return;
1233 }
1234 if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1235 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1236 return;
1237 }
1238 if (!V_ip6_dad_count) {
1239 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1240 return;
1241 }
1242 if (ifa->ifa_ifp == NULL)
1243 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1244 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) {
1245 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1246 return;
1247 }
1248 if (!(ifa->ifa_ifp->if_flags & IFF_UP) ||
1249 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) ||
1250 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) {
1251 ia->ia6_flags |= IN6_IFF_TENTATIVE;
1252 return;
1253 }
1254 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1255 /*
1256 * DAD is already in progress. Let the existing entry
1257 * finish it.
1258 */
1259 nd6_dad_rele(dp);
1260 return;
1261 }
1262
1263 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1264 if (dp == NULL) {
1265 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1266 "%s(%s)\n",
1267 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1268 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1269 return;
1270 }
1271 callout_init(&dp->dad_timer_ch, 0);
1272 #ifdef VIMAGE
1273 dp->dad_vnet = curvnet;
1274 #endif
1275 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1276 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1277
1278 /*
1279 * Send NS packet for DAD, ip6_dad_count times.
1280 * Note that we must delay the first transmission, if this is the
1281 * first packet to be sent from the interface after interface
1282 * (re)initialization.
1283 */
1284 dp->dad_ifa = ifa;
1285 ifa_ref(dp->dad_ifa);
1286 dp->dad_count = V_ip6_dad_count;
1287 dp->dad_ns_icount = dp->dad_na_icount = 0;
1288 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1289 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1290 refcount_init(&dp->dad_refcnt, 1);
1291 nd6_dad_add(dp);
1292 nd6_dad_starttimer(dp, delay, 0);
1293 }
1294
1295 /*
1296 * terminate DAD unconditionally. used for address removals.
1297 */
1298 void
1299 nd6_dad_stop(struct ifaddr *ifa)
1300 {
1301 struct dadq *dp;
1302
1303 dp = nd6_dad_find(ifa, NULL);
1304 if (!dp) {
1305 /* DAD wasn't started yet */
1306 return;
1307 }
1308
1309 nd6_dad_stoptimer(dp);
1310
1311 /*
1312 * The DAD queue entry may have been removed by nd6_dad_timer() while
1313 * we were waiting for it to stop, so re-do the lookup.
1314 */
1315 nd6_dad_rele(dp);
1316 if (nd6_dad_find(ifa, NULL) == NULL)
1317 return;
1318
1319 nd6_dad_del(dp);
1320 nd6_dad_rele(dp);
1321 }
1322
1323 static void
1324 nd6_dad_timer(struct dadq *dp)
1325 {
1326 CURVNET_SET(dp->dad_vnet);
1327 struct ifaddr *ifa = dp->dad_ifa;
1328 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1329 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1330 char ip6buf[INET6_ADDRSTRLEN];
1331
1332 /* Sanity check */
1333 if (ia == NULL) {
1334 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1335 goto err;
1336 }
1337 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
1338 /* Do not need DAD for ifdisabled interface. */
1339 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1340 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1341 goto err;
1342 }
1343 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1344 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1345 "%s(%s)\n",
1346 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1347 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1348 goto err;
1349 }
1350 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1351 log(LOG_ERR, "nd6_dad_timer: called with non-tentative 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 err;
1356 }
1357
1358 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1359 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1360 (((ifp->if_flags & IFF_UP) == 0) ||
1361 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1362 nd6log((LOG_INFO, "%s: could not run DAD "
1363 "because the interface was down or not running.\n",
1364 if_name(ifa->ifa_ifp)));
1365 goto err;
1366 }
1367
1368 /* Need more checks? */
1369 if (dp->dad_ns_ocount < dp->dad_count) {
1370 /*
1371 * We have more NS to go. Send NS packet for DAD.
1372 */
1373 nd6_dad_starttimer(dp,
1374 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1);
1375 goto done;
1376 } else {
1377 /*
1378 * We have transmitted sufficient number of DAD packets.
1379 * See what we've got.
1380 */
1381 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0)
1382 /* We've seen NS or NA, means DAD has failed. */
1383 nd6_dad_duplicated(ifa, dp);
1384 else if (V_dad_enhanced != 0 &&
1385 dp->dad_ns_lcount > 0 &&
1386 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1387 /*
1388 * Sec. 4.1 in RFC 7527 requires transmission of
1389 * additional probes until the loopback condition
1390 * becomes clear when a looped back probe is detected.
1391 */
1392 log(LOG_ERR, "%s: a looped back NS message is "
1393 "detected during DAD for %s. "
1394 "Another DAD probes are being sent.\n",
1395 if_name(ifa->ifa_ifp),
1396 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1397 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1398 /*
1399 * Send an NS immediately and increase dad_count by
1400 * V_nd6_mmaxtries - 1.
1401 */
1402 dp->dad_count =
1403 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1404 nd6_dad_starttimer(dp,
1405 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000,
1406 1);
1407 goto done;
1408 } else {
1409 /*
1410 * We are done with DAD. No NA came, no NS came.
1411 * No duplicate address found. Check IFDISABLED flag
1412 * again in case that it is changed between the
1413 * beginning of this function and here.
1414 */
1415 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
1416 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1417
1418 nd6log((LOG_DEBUG,
1419 "%s: DAD complete for %s - no duplicates found\n",
1420 if_name(ifa->ifa_ifp),
1421 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1422 if (dp->dad_ns_lcount > 0)
1423 log(LOG_ERR, "%s: DAD completed while "
1424 "a looped back NS message is detected "
1425 "during DAD for %s.\n",
1426 if_name(ifa->ifa_ifp),
1427 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1428 }
1429 }
1430 err:
1431 nd6_dad_del(dp);
1432 done:
1433 CURVNET_RESTORE();
1434 }
1435
1436 static void
1437 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1438 {
1439 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1440 struct ifnet *ifp;
1441 char ip6buf[INET6_ADDRSTRLEN];
1442
1443 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1444 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1445 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1446 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1447 dp->dad_na_icount);
1448
1449 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1450 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1451
1452 ifp = ifa->ifa_ifp;
1453 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1454 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1455 log(LOG_ERR, "%s: manual intervention required\n",
1456 if_name(ifp));
1457
1458 /*
1459 * If the address is a link-local address formed from an interface
1460 * identifier based on the hardware address which is supposed to be
1461 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1462 * operation on the interface SHOULD be disabled.
1463 * [RFC 4862, Section 5.4.5]
1464 */
1465 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1466 struct in6_addr in6;
1467
1468 /*
1469 * To avoid over-reaction, we only apply this logic when we are
1470 * very sure that hardware addresses are supposed to be unique.
1471 */
1472 switch (ifp->if_type) {
1473 case IFT_ETHER:
1474 case IFT_FDDI:
1475 case IFT_ATM:
1476 case IFT_IEEE1394:
1477 case IFT_IEEE80211:
1478 case IFT_INFINIBAND:
1479 in6 = ia->ia_addr.sin6_addr;
1480 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1481 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1482 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1483 log(LOG_ERR, "%s: possible hardware address "
1484 "duplication detected, disable IPv6\n",
1485 if_name(ifp));
1486 }
1487 break;
1488 }
1489 }
1490 }
1491
1492 static void
1493 nd6_dad_ns_output(struct dadq *dp)
1494 {
1495 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1496 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1497 int i;
1498
1499 dp->dad_ns_tcount++;
1500 if ((ifp->if_flags & IFF_UP) == 0) {
1501 return;
1502 }
1503 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1504 return;
1505 }
1506
1507 dp->dad_ns_ocount++;
1508 if (V_dad_enhanced != 0) {
1509 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1510 dp->dad_nonce[i] = arc4random();
1511 /*
1512 * XXXHRS: Note that in the case that
1513 * DupAddrDetectTransmits > 1, multiple NS messages with
1514 * different nonces can be looped back in an unexpected
1515 * order. The current implementation recognizes only
1516 * the latest nonce on the sender side. Practically it
1517 * should work well in almost all cases.
1518 */
1519 }
1520 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1521 (uint8_t *)&dp->dad_nonce[0]);
1522 }
1523
1524 static void
1525 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1526 {
1527 struct in6_ifaddr *ia;
1528 struct ifnet *ifp;
1529 const struct in6_addr *taddr6;
1530 struct dadq *dp;
1531
1532 if (ifa == NULL)
1533 panic("ifa == NULL in nd6_dad_ns_input");
1534
1535 ia = (struct in6_ifaddr *)ifa;
1536 ifp = ifa->ifa_ifp;
1537 taddr6 = &ia->ia_addr.sin6_addr;
1538 /* Ignore Nonce option when Enhanced DAD is disabled. */
1539 if (V_dad_enhanced == 0)
1540 ndopt_nonce = NULL;
1541 dp = nd6_dad_find(ifa, ndopt_nonce);
1542 if (dp == NULL)
1543 return;
1544
1545 dp->dad_ns_icount++;
1546 nd6_dad_rele(dp);
1547 }
1548
1549 static void
1550 nd6_dad_na_input(struct ifaddr *ifa)
1551 {
1552 struct dadq *dp;
1553
1554 if (ifa == NULL)
1555 panic("ifa == NULL in nd6_dad_na_input");
1556
1557 dp = nd6_dad_find(ifa, NULL);
1558 if (dp != NULL) {
1559 dp->dad_na_icount++;
1560 nd6_dad_rele(dp);
1561 }
1562 }
Cache object: 2ee38162d055ceb610954d44affb69b6
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