1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36
37 #include "opt_inet.h"
38 #include "opt_inet6.h"
39 #include "opt_ipsec.h"
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/eventhandler.h>
44 #include <sys/malloc.h>
45 #include <sys/libkern.h>
46 #include <sys/lock.h>
47 #include <sys/rwlock.h>
48 #include <sys/mbuf.h>
49 #include <sys/socket.h>
50 #include <sys/sockio.h>
51 #include <sys/time.h>
52 #include <sys/kernel.h>
53 #include <sys/errno.h>
54 #include <sys/sysctl.h>
55 #include <sys/syslog.h>
56 #include <sys/queue.h>
57 #include <sys/callout.h>
58 #include <sys/refcount.h>
59
60 #include <net/if.h>
61 #include <net/if_types.h>
62 #include <net/if_dl.h>
63 #include <net/if_var.h>
64 #include <net/route.h>
65 #include <net/vnet.h>
66
67 #include <netinet/in.h>
68 #include <netinet/in_var.h>
69 #include <net/if_llatbl.h>
70 #include <netinet6/in6_var.h>
71 #include <netinet6/in6_ifattach.h>
72 #include <netinet/ip6.h>
73 #include <netinet6/ip6_var.h>
74 #include <netinet6/scope6_var.h>
75 #include <netinet6/nd6.h>
76 #include <netinet/icmp6.h>
77 #include <netinet/ip_carp.h>
78 #include <netinet6/send.h>
79
80 #define SDL(s) ((struct sockaddr_dl *)s)
81
82 struct dadq;
83 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *);
84 static void nd6_dad_add(struct dadq *dp);
85 static void nd6_dad_del(struct dadq *dp);
86 static void nd6_dad_rele(struct dadq *);
87 static void nd6_dad_starttimer(struct dadq *, int);
88 static void nd6_dad_stoptimer(struct dadq *);
89 static void nd6_dad_timer(void *);
90 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *);
91 static void nd6_dad_ns_output(struct dadq *);
92 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *);
93 static void nd6_dad_na_input(struct ifaddr *);
94 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
95 const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
96 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *,
97 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int);
98
99 static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *,
100 const struct in6_addr *, struct sockaddr_dl *);
101
102 VNET_DEFINE_STATIC(int, dad_enhanced) = 1;
103 #define V_dad_enhanced VNET(dad_enhanced)
104
105 SYSCTL_DECL(_net_inet6_ip6);
106 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
107 &VNET_NAME(dad_enhanced), 0,
108 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
109
110 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to
111 transmit DAD packet */
112 #define V_dad_maxtry VNET(dad_maxtry)
113
114 /*
115 * Input a Neighbor Solicitation Message.
116 *
117 * Based on RFC 2461
118 * Based on RFC 2462 (duplicate address detection)
119 */
120 void
121 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
122 {
123 struct ifnet *ifp;
124 struct ip6_hdr *ip6;
125 struct nd_neighbor_solicit *nd_ns;
126 struct in6_addr daddr6, myaddr6, saddr6, taddr6;
127 struct ifaddr *ifa;
128 struct sockaddr_dl proxydl;
129 union nd_opts ndopts;
130 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
131 char *lladdr;
132 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr;
133
134 ifa = NULL;
135
136 /* RFC 6980: Nodes MUST silently ignore fragments */
137 if(m->m_flags & M_FRAGMENTED)
138 goto freeit;
139
140 ifp = m->m_pkthdr.rcvif;
141 ip6 = mtod(m, struct ip6_hdr *);
142 if (__predict_false(ip6->ip6_hlim != 255)) {
143 ICMP6STAT_INC(icp6s_invlhlim);
144 nd6log((LOG_ERR,
145 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
146 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
147 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
148 goto bads;
149 }
150
151 if (m->m_len < off + icmp6len) {
152 m = m_pullup(m, off + icmp6len);
153 if (m == NULL) {
154 IP6STAT_INC(ip6s_exthdrtoolong);
155 return;
156 }
157 }
158 ip6 = mtod(m, struct ip6_hdr *);
159 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
160
161 saddr6 = ip6->ip6_src;
162 daddr6 = ip6->ip6_dst;
163 taddr6 = nd_ns->nd_ns_target;
164 if (in6_setscope(&taddr6, ifp, NULL) != 0)
165 goto bad;
166
167 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
168 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
169 rflag = 0;
170
171 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
172 /* dst has to be a solicited node multicast address. */
173 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
174 /* don't check ifindex portion */
175 daddr6.s6_addr32[1] == 0 &&
176 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
177 daddr6.s6_addr8[12] == 0xff) {
178 ; /* good */
179 } else {
180 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
181 "(wrong ip6 dst)\n"));
182 goto bad;
183 }
184 } else if (!V_nd6_onlink_ns_rfc4861) {
185 struct sockaddr_in6 src_sa6;
186
187 /*
188 * According to recent IETF discussions, it is not a good idea
189 * to accept a NS from an address which would not be deemed
190 * to be a neighbor otherwise. This point is expected to be
191 * clarified in future revisions of the specification.
192 */
193 bzero(&src_sa6, sizeof(src_sa6));
194 src_sa6.sin6_family = AF_INET6;
195 src_sa6.sin6_len = sizeof(src_sa6);
196 src_sa6.sin6_addr = saddr6;
197 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
198 nd6log((LOG_INFO, "nd6_ns_input: "
199 "NS packet from non-neighbor\n"));
200 goto bad;
201 }
202 }
203
204 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
205 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
206 goto bad;
207 }
208
209 icmp6len -= sizeof(*nd_ns);
210 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
211 if (nd6_options(&ndopts) < 0) {
212 nd6log((LOG_INFO,
213 "nd6_ns_input: invalid ND option, ignored\n"));
214 /* nd6_options have incremented stats */
215 goto freeit;
216 }
217
218 lladdr = NULL;
219 lladdrlen = 0;
220 if (ndopts.nd_opts_src_lladdr) {
221 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
222 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
223 }
224
225 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
226 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
227 "(link-layer address option)\n"));
228 goto bad;
229 }
230
231 /*
232 * Attaching target link-layer address to the NA?
233 * (RFC 2461 7.2.4)
234 *
235 * NS IP dst is unicast/anycast MUST NOT add
236 * NS IP dst is solicited-node multicast MUST add
237 *
238 * In implementation, we add target link-layer address by default.
239 * We do not add one in MUST NOT cases.
240 */
241 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
242 tlladdr = 0;
243 else
244 tlladdr = 1;
245
246 /*
247 * Target address (taddr6) must be either:
248 * (1) Valid unicast/anycast address for my receiving interface,
249 * (2) Unicast address for which I'm offering proxy service, or
250 * (3) "tentative" address on which DAD is being performed.
251 */
252 /* (1) and (3) check. */
253 if (ifp->if_carp)
254 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
255 else
256 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
257
258 /* (2) check. */
259 proxy = 0;
260 if (ifa == NULL) {
261 if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL)
262 proxy = 1;
263 }
264 if (ifa == NULL) {
265 /*
266 * We've got an NS packet, and we don't have that adddress
267 * assigned for us. We MUST silently ignore it.
268 * See RFC2461 7.2.3.
269 */
270 goto freeit;
271 }
272 myaddr6 = *IFA_IN6(ifa);
273 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
274 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
275 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
276 goto freeit;
277
278 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
279 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
280 "(if %d, NS packet %d)\n",
281 ip6_sprintf(ip6bufs, &taddr6),
282 ifp->if_addrlen, lladdrlen - 2));
283 goto bad;
284 }
285
286 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
287 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
288 ip6_sprintf(ip6bufs, &saddr6)));
289 goto freeit;
290 }
291
292 /*
293 * We have neighbor solicitation packet, with target address equals to
294 * one of my tentative address.
295 *
296 * src addr how to process?
297 * --- ---
298 * multicast of course, invalid (rejected in ip6_input)
299 * unicast somebody is doing address resolution -> ignore
300 * unspec dup address detection
301 *
302 * The processing is defined in RFC 2462.
303 */
304 if (tentative) {
305 /*
306 * If source address is unspecified address, it is for
307 * duplicate address detection.
308 *
309 * If not, the packet is for addess resolution;
310 * silently ignore it.
311 */
312 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
313 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
314
315 goto freeit;
316 }
317
318 /*
319 * If the source address is unspecified address, entries must not
320 * be created or updated.
321 * It looks that sender is performing DAD. Output NA toward
322 * all-node multicast address, to tell the sender that I'm using
323 * the address.
324 * S bit ("solicited") must be zero.
325 */
326 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
327 struct in6_addr in6_all;
328
329 in6_all = in6addr_linklocal_allnodes;
330 if (in6_setscope(&in6_all, ifp, NULL) != 0)
331 goto bad;
332 nd6_na_output_fib(ifp, &in6_all, &taddr6,
333 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
334 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
335 M_GETFIB(m));
336 goto freeit;
337 }
338
339 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
340 ND_NEIGHBOR_SOLICIT, 0);
341
342 nd6_na_output_fib(ifp, &saddr6, &taddr6,
343 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
344 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
345 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
346 freeit:
347 if (ifa != NULL)
348 ifa_free(ifa);
349 m_freem(m);
350 return;
351
352 bad:
353 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
354 ip6_sprintf(ip6bufs, &saddr6)));
355 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
356 ip6_sprintf(ip6bufs, &daddr6)));
357 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
358 ip6_sprintf(ip6bufs, &taddr6)));
359 bads:
360 ICMP6STAT_INC(icp6s_badns);
361 if (ifa != NULL)
362 ifa_free(ifa);
363 m_freem(m);
364 }
365
366 static struct ifaddr *
367 nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6,
368 struct sockaddr_dl *sdl)
369 {
370 struct ifaddr *ifa;
371 struct llentry *ln;
372
373 ifa = NULL;
374 ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp);
375 if (ln == NULL)
376 return (ifa);
377 if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) {
378 link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type);
379 sdl->sdl_alen = ifp->if_addrlen;
380 bcopy(ln->ll_addr, &sdl->sdl_data, ifp->if_addrlen);
381 LLE_RUNLOCK(ln);
382 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
383 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
384 } else
385 LLE_RUNLOCK(ln);
386
387 return (ifa);
388 }
389
390 /*
391 * Output a Neighbor Solicitation Message. Caller specifies:
392 * - ICMP6 header source IP6 address
393 * - ND6 header target IP6 address
394 * - ND6 header source datalink address
395 *
396 * Based on RFC 2461
397 * Based on RFC 2462 (duplicate address detection)
398 *
399 * ln - for source address determination
400 * nonce - If non-NULL, NS is used for duplicate address detection and
401 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
402 */
403 static void
404 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
405 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
406 uint8_t *nonce, u_int fibnum)
407 {
408 struct mbuf *m;
409 struct m_tag *mtag;
410 struct ip6_hdr *ip6;
411 struct nd_neighbor_solicit *nd_ns;
412 struct ip6_moptions im6o;
413 int icmp6len;
414 int maxlen;
415
416 NET_EPOCH_ASSERT();
417
418 if (IN6_IS_ADDR_MULTICAST(taddr6))
419 return;
420
421 /* estimate the size of message */
422 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
423 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
424 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
425 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
426 __func__, max_linkhdr, maxlen, MCLBYTES));
427
428 if (max_linkhdr + maxlen > MHLEN)
429 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
430 else
431 m = m_gethdr(M_NOWAIT, MT_DATA);
432 if (m == NULL)
433 return;
434 M_SETFIB(m, fibnum);
435
436 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
437 m->m_flags |= M_MCAST;
438 im6o.im6o_multicast_ifp = ifp;
439 im6o.im6o_multicast_hlim = 255;
440 im6o.im6o_multicast_loop = 0;
441 }
442
443 icmp6len = sizeof(*nd_ns);
444 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
445 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
446
447 /* fill neighbor solicitation packet */
448 ip6 = mtod(m, struct ip6_hdr *);
449 ip6->ip6_flow = 0;
450 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
451 ip6->ip6_vfc |= IPV6_VERSION;
452 /* ip6->ip6_plen will be set later */
453 ip6->ip6_nxt = IPPROTO_ICMPV6;
454 ip6->ip6_hlim = 255;
455 if (daddr6)
456 ip6->ip6_dst = *daddr6;
457 else {
458 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
459 ip6->ip6_dst.s6_addr16[1] = 0;
460 ip6->ip6_dst.s6_addr32[1] = 0;
461 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
462 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
463 ip6->ip6_dst.s6_addr8[12] = 0xff;
464 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
465 goto bad;
466 }
467 if (nonce == NULL) {
468 char ip6buf[INET6_ADDRSTRLEN];
469 struct ifaddr *ifa = NULL;
470
471 /*
472 * RFC2461 7.2.2:
473 * "If the source address of the packet prompting the
474 * solicitation is the same as one of the addresses assigned
475 * to the outgoing interface, that address SHOULD be placed
476 * in the IP Source Address of the outgoing solicitation.
477 * Otherwise, any one of the addresses assigned to the
478 * interface should be used."
479 *
480 * We use the source address for the prompting packet
481 * (saddr6), if saddr6 belongs to the outgoing interface.
482 * Otherwise, we perform the source address selection as usual.
483 */
484 if (saddr6 != NULL)
485 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
486 if (ifa == NULL) {
487 int error;
488 struct in6_addr dst6, src6;
489 uint32_t scopeid;
490
491 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
492 error = in6_selectsrc_addr(fibnum, &dst6,
493 scopeid, ifp, &src6, NULL);
494 if (error) {
495 nd6log((LOG_DEBUG, "%s: source can't be "
496 "determined: dst=%s, error=%d\n", __func__,
497 ip6_sprintf(ip6buf, &dst6),
498 error));
499 goto bad;
500 }
501 ip6->ip6_src = src6;
502 } else
503 ip6->ip6_src = *saddr6;
504
505 if (ifp->if_carp != NULL) {
506 /*
507 * Check that selected source address belongs to
508 * CARP addresses.
509 */
510 if (ifa == NULL)
511 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
512 &ip6->ip6_src);
513 /*
514 * Do not send NS for CARP address if we are not
515 * the CARP master.
516 */
517 if (ifa != NULL && ifa->ifa_carp != NULL &&
518 !(*carp_master_p)(ifa)) {
519 log(LOG_DEBUG,
520 "nd6_ns_output: NS from BACKUP CARP address %s\n",
521 ip6_sprintf(ip6buf, &ip6->ip6_src));
522 ifa_free(ifa);
523 goto bad;
524 }
525 }
526 if (ifa != NULL)
527 ifa_free(ifa);
528 } else {
529 /*
530 * Source address for DAD packet must always be IPv6
531 * unspecified address. (0::0)
532 * We actually don't have to 0-clear the address (we did it
533 * above), but we do so here explicitly to make the intention
534 * clearer.
535 */
536 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
537 }
538 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
539 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
540 nd_ns->nd_ns_code = 0;
541 nd_ns->nd_ns_reserved = 0;
542 nd_ns->nd_ns_target = *taddr6;
543 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
544
545 /*
546 * Add source link-layer address option.
547 *
548 * spec implementation
549 * --- ---
550 * DAD packet MUST NOT do not add the option
551 * there's no link layer address:
552 * impossible do not add the option
553 * there's link layer address:
554 * Multicast NS MUST add one add the option
555 * Unicast NS SHOULD add one add the option
556 */
557 if (nonce == NULL) {
558 struct nd_opt_hdr *nd_opt;
559 char *mac;
560 int optlen;
561
562 mac = NULL;
563 if (ifp->if_carp)
564 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src);
565 if (mac == NULL)
566 mac = nd6_ifptomac(ifp);
567
568 if (mac != NULL) {
569 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
570 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
571 /* 8 byte alignments... */
572 optlen = (optlen + 7) & ~7;
573 m->m_pkthdr.len += optlen;
574 m->m_len += optlen;
575 icmp6len += optlen;
576 bzero(nd_opt, optlen);
577 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
578 nd_opt->nd_opt_len = optlen >> 3;
579 bcopy(mac, nd_opt + 1, ifp->if_addrlen);
580 }
581 }
582 /*
583 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
584 * This behavior is documented as Enhanced Duplicate Address
585 * Detection in RFC 7527.
586 * net.inet6.ip6.dad_enhanced=0 disables this.
587 */
588 if (V_dad_enhanced != 0 && nonce != NULL) {
589 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
590 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
591 /* 8-byte alignment is required. */
592 optlen = (optlen + 7) & ~7;
593
594 m->m_pkthdr.len += optlen;
595 m->m_len += optlen;
596 icmp6len += optlen;
597 bzero((caddr_t)nd_opt, optlen);
598 nd_opt->nd_opt_type = ND_OPT_NONCE;
599 nd_opt->nd_opt_len = optlen >> 3;
600 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
601 }
602 ip6->ip6_plen = htons((u_short)icmp6len);
603 nd_ns->nd_ns_cksum = 0;
604 nd_ns->nd_ns_cksum =
605 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
606
607 if (send_sendso_input_hook != NULL) {
608 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
609 sizeof(unsigned short), M_NOWAIT);
610 if (mtag == NULL)
611 goto bad;
612 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
613 m_tag_prepend(m, mtag);
614 }
615
616 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
617 &im6o, NULL, NULL);
618 icmp6_ifstat_inc(ifp, ifs6_out_msg);
619 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
620 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
621
622 return;
623
624 bad:
625 m_freem(m);
626 }
627
628 #ifndef BURN_BRIDGES
629 void
630 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
631 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
632 {
633
634 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
635 }
636 #endif
637 /*
638 * Neighbor advertisement input handling.
639 *
640 * Based on RFC 2461
641 * Based on RFC 2462 (duplicate address detection)
642 *
643 * the following items are not implemented yet:
644 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
645 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
646 */
647 void
648 nd6_na_input(struct mbuf *m, int off, int icmp6len)
649 {
650 struct ifnet *ifp;
651 struct ip6_hdr *ip6;
652 struct ifaddr *ifa;
653 struct llentry *ln;
654 struct mbuf *chain;
655 struct nd_neighbor_advert *nd_na;
656 struct in6_addr daddr6, taddr6;
657 union nd_opts ndopts;
658 u_char linkhdr[LLE_MAX_LINKHDR];
659 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
660 char *lladdr;
661 size_t linkhdrsize;
662 int flags, is_override, is_router, is_solicited;
663 int lladdr_off, lladdrlen, checklink;
664 bool flush_holdchain = false;
665
666 NET_EPOCH_ASSERT();
667
668 chain = NULL;
669 ln = NULL;
670 checklink = 0;
671
672 /* RFC 6980: Nodes MUST silently ignore fragments */
673 if(m->m_flags & M_FRAGMENTED)
674 goto freeit;
675
676 ifp = m->m_pkthdr.rcvif;
677 ip6 = mtod(m, struct ip6_hdr *);
678 if (__predict_false(ip6->ip6_hlim != 255)) {
679 ICMP6STAT_INC(icp6s_invlhlim);
680 nd6log((LOG_ERR,
681 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
682 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
683 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
684 goto bad;
685 }
686
687 if (m->m_len < off + icmp6len) {
688 m = m_pullup(m, off + icmp6len);
689 if (m == NULL) {
690 IP6STAT_INC(ip6s_exthdrtoolong);
691 return;
692 }
693 }
694 ip6 = mtod(m, struct ip6_hdr *);
695 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
696
697 flags = nd_na->nd_na_flags_reserved;
698 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
699 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
700 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
701
702 taddr6 = nd_na->nd_na_target;
703 if (in6_setscope(&taddr6, ifp, NULL))
704 goto bad; /* XXX: impossible */
705
706 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
707 nd6log((LOG_ERR,
708 "nd6_na_input: invalid target address %s\n",
709 ip6_sprintf(ip6bufs, &taddr6)));
710 goto bad;
711 }
712
713 daddr6 = ip6->ip6_dst;
714 if (IN6_IS_ADDR_MULTICAST(&daddr6))
715 if (is_solicited) {
716 nd6log((LOG_ERR,
717 "nd6_na_input: a solicited adv is multicasted\n"));
718 goto bad;
719 }
720
721 icmp6len -= sizeof(*nd_na);
722 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
723 if (nd6_options(&ndopts) < 0) {
724 nd6log((LOG_INFO,
725 "nd6_na_input: invalid ND option, ignored\n"));
726 /* nd6_options have incremented stats */
727 goto freeit;
728 }
729
730 lladdr = NULL;
731 lladdrlen = 0;
732 if (ndopts.nd_opts_tgt_lladdr) {
733 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
734 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
735 }
736
737 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
738 if (ifa != NULL && ifa->ifa_carp != NULL) {
739 /*
740 * Silently ignore NAs for CARP addresses if we are not
741 * the CARP master.
742 */
743 if (!(*carp_master_p)(ifa)) {
744 log(LOG_DEBUG,
745 "nd6_na_input: NA for BACKUP CARP address %s\n",
746 ip6_sprintf(ip6bufs, &taddr6));
747 ifa_free(ifa);
748 goto freeit;
749 }
750 }
751 /*
752 * Target address matches one of my interface address.
753 *
754 * If my address is tentative, this means that there's somebody
755 * already using the same address as mine. This indicates DAD failure.
756 * This is defined in RFC 2462.
757 *
758 * Otherwise, process as defined in RFC 2461.
759 */
760 if (ifa
761 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
762 nd6_dad_na_input(ifa);
763 ifa_free(ifa);
764 goto freeit;
765 }
766
767 /* Just for safety, maybe unnecessary. */
768 if (ifa) {
769 ifa_free(ifa);
770 log(LOG_ERR,
771 "nd6_na_input: duplicate IP6 address %s\n",
772 ip6_sprintf(ip6bufs, &taddr6));
773 goto freeit;
774 }
775
776 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
777 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
778 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
779 ifp->if_addrlen, lladdrlen - 2));
780 goto bad;
781 }
782
783 /*
784 * If no neighbor cache entry is found, NA SHOULD silently be
785 * discarded.
786 */
787 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
788 if (ln == NULL) {
789 goto freeit;
790 }
791
792 /*
793 * Do not try to override static entry.
794 */
795 if (ln->la_flags & LLE_STATIC)
796 goto freeit;
797
798 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
799 /*
800 * If the link-layer has address, and no lladdr option came,
801 * discard the packet.
802 */
803 if (ifp->if_addrlen && lladdr == NULL) {
804 goto freeit;
805 }
806
807 /*
808 * Record link-layer address, and update the state.
809 */
810 if (!nd6_try_set_entry_addr(ifp, ln, lladdr))
811 goto freeit;
812
813 flush_holdchain = true;
814 if (is_solicited)
815 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
816 else
817 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
818 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
819 if ((ln->ln_router = is_router) != 0) {
820 /*
821 * This means a router's state has changed from
822 * non-reachable to probably reachable, and might
823 * affect the status of associated prefixes..
824 */
825 checklink = 1;
826 }
827 } else {
828 int llchange;
829
830 /*
831 * Check if the link-layer address has changed or not.
832 */
833 if (lladdr == NULL)
834 llchange = 0;
835 else {
836 if (ln->la_flags & LLE_VALID) {
837 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
838 llchange = 1;
839 else
840 llchange = 0;
841 } else
842 llchange = 1;
843 }
844
845 /*
846 * This is VERY complex. Look at it with care.
847 *
848 * override solicit lladdr llchange action
849 * (L: record lladdr)
850 *
851 * 0 0 n -- (2c)
852 * 0 0 y n (2b) L
853 * 0 0 y y (1) REACHABLE->STALE
854 * 0 1 n -- (2c) *->REACHABLE
855 * 0 1 y n (2b) L *->REACHABLE
856 * 0 1 y y (1) REACHABLE->STALE
857 * 1 0 n -- (2a)
858 * 1 0 y n (2a) L
859 * 1 0 y y (2a) L *->STALE
860 * 1 1 n -- (2a) *->REACHABLE
861 * 1 1 y n (2a) L *->REACHABLE
862 * 1 1 y y (2a) L *->REACHABLE
863 */
864 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
865 /*
866 * If state is REACHABLE, make it STALE.
867 * no other updates should be done.
868 */
869 if (ln->ln_state == ND6_LLINFO_REACHABLE)
870 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
871 goto freeit;
872 } else if (is_override /* (2a) */
873 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
874 || lladdr == NULL) { /* (2c) */
875 /*
876 * Update link-local address, if any.
877 */
878 if (lladdr != NULL) {
879 linkhdrsize = sizeof(linkhdr);
880 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
881 linkhdr, &linkhdrsize, &lladdr_off) != 0)
882 goto freeit;
883 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
884 linkhdrsize, lladdr_off) == 0)
885 goto freeit;
886 EVENTHANDLER_INVOKE(lle_event, ln,
887 LLENTRY_RESOLVED);
888 }
889
890 /*
891 * If solicited, make the state REACHABLE.
892 * If not solicited and the link-layer address was
893 * changed, make it STALE.
894 */
895 if (is_solicited)
896 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
897 else {
898 if (lladdr != NULL && llchange)
899 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
900 }
901 }
902
903 if (ln->ln_router && !is_router) {
904 /*
905 * The peer dropped the router flag.
906 * Remove the sender from the Default Router List and
907 * update the Destination Cache entries.
908 */
909 struct ifnet *nd6_ifp;
910
911 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
912 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
913 (ND_IFINFO(nd6_ifp)->flags &
914 ND6_IFF_ACCEPT_RTADV) != 0)
915 /*
916 * Even if the neighbor is not in the default
917 * router list, the neighbor may be used as a
918 * next hop for some destinations (e.g. redirect
919 * case). So we must call rt6_flush explicitly.
920 */
921 rt6_flush(&ip6->ip6_src, ifp);
922 }
923 ln->ln_router = is_router;
924 }
925 /* XXX - QL
926 * Does this matter?
927 * rt->rt_flags &= ~RTF_REJECT;
928 */
929 ln->la_asked = 0;
930 if (ln->la_hold != NULL)
931 chain = nd6_grab_holdchain(ln);
932 freeit:
933 if (ln != NULL)
934 LLE_WUNLOCK(ln);
935
936 if (chain != NULL)
937 nd6_flush_holdchain(ifp, ln, chain);
938 if (flush_holdchain)
939 nd6_flush_children_holdchain(ifp, ln);
940
941 if (checklink)
942 pfxlist_onlink_check();
943
944 m_freem(m);
945 return;
946
947 bad:
948 if (ln != NULL)
949 LLE_WUNLOCK(ln);
950
951 ICMP6STAT_INC(icp6s_badna);
952 m_freem(m);
953 }
954
955 /*
956 * Neighbor advertisement output handling.
957 *
958 * Based on RFC 2461
959 *
960 * the following items are not implemented yet:
961 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
962 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
963 *
964 * tlladdr - 1 if include target link-layer address
965 * sdl0 - sockaddr_dl (= proxy NA) or NULL
966 */
967 static void
968 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
969 const struct in6_addr *taddr6, u_long flags, int tlladdr,
970 struct sockaddr *sdl0, u_int fibnum)
971 {
972 struct mbuf *m;
973 struct m_tag *mtag;
974 struct ip6_hdr *ip6;
975 struct nd_neighbor_advert *nd_na;
976 struct ip6_moptions im6o;
977 struct in6_addr daddr6, dst6, src6;
978 uint32_t scopeid;
979
980 NET_EPOCH_ASSERT();
981
982 int icmp6len, maxlen, error;
983 caddr_t mac = NULL;
984
985 daddr6 = *daddr6_0; /* make a local copy for modification */
986
987 /* estimate the size of message */
988 maxlen = sizeof(*ip6) + sizeof(*nd_na);
989 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
990 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
991 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
992 __func__, max_linkhdr, maxlen, MCLBYTES));
993
994 if (max_linkhdr + maxlen > MHLEN)
995 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
996 else
997 m = m_gethdr(M_NOWAIT, MT_DATA);
998 if (m == NULL)
999 return;
1000 M_SETFIB(m, fibnum);
1001
1002 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
1003 m->m_flags |= M_MCAST;
1004 im6o.im6o_multicast_ifp = ifp;
1005 im6o.im6o_multicast_hlim = 255;
1006 im6o.im6o_multicast_loop = 0;
1007 }
1008
1009 icmp6len = sizeof(*nd_na);
1010 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
1011 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
1012
1013 /* fill neighbor advertisement packet */
1014 ip6 = mtod(m, struct ip6_hdr *);
1015 ip6->ip6_flow = 0;
1016 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1017 ip6->ip6_vfc |= IPV6_VERSION;
1018 ip6->ip6_nxt = IPPROTO_ICMPV6;
1019 ip6->ip6_hlim = 255;
1020 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
1021 /* reply to DAD */
1022 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
1023 daddr6.s6_addr16[1] = 0;
1024 daddr6.s6_addr32[1] = 0;
1025 daddr6.s6_addr32[2] = 0;
1026 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
1027 if (in6_setscope(&daddr6, ifp, NULL))
1028 goto bad;
1029
1030 flags &= ~ND_NA_FLAG_SOLICITED;
1031 }
1032 ip6->ip6_dst = daddr6;
1033
1034 /*
1035 * Select a source whose scope is the same as that of the dest.
1036 */
1037 in6_splitscope(&daddr6, &dst6, &scopeid);
1038 error = in6_selectsrc_addr(fibnum, &dst6,
1039 scopeid, ifp, &src6, NULL);
1040 if (error) {
1041 char ip6buf[INET6_ADDRSTRLEN];
1042 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1043 "determined: dst=%s, error=%d\n",
1044 ip6_sprintf(ip6buf, &daddr6), error));
1045 goto bad;
1046 }
1047 ip6->ip6_src = src6;
1048 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1049 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1050 nd_na->nd_na_code = 0;
1051 nd_na->nd_na_target = *taddr6;
1052 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1053
1054 /*
1055 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1056 * see nd6_ns_input() for details.
1057 * Basically, if NS packet is sent to unicast/anycast addr,
1058 * target lladdr option SHOULD NOT be included.
1059 */
1060 if (tlladdr) {
1061 /*
1062 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1063 * lladdr in sdl0. If we are not proxying (sending NA for
1064 * my address) use lladdr configured for the interface.
1065 */
1066 if (sdl0 == NULL) {
1067 if (ifp->if_carp)
1068 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1069 if (mac == NULL)
1070 mac = nd6_ifptomac(ifp);
1071 } else if (sdl0->sa_family == AF_LINK) {
1072 struct sockaddr_dl *sdl;
1073 sdl = (struct sockaddr_dl *)sdl0;
1074 if (sdl->sdl_alen == ifp->if_addrlen)
1075 mac = LLADDR(sdl);
1076 }
1077 }
1078 if (tlladdr && mac) {
1079 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1080 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1081
1082 /* roundup to 8 bytes alignment! */
1083 optlen = (optlen + 7) & ~7;
1084
1085 m->m_pkthdr.len += optlen;
1086 m->m_len += optlen;
1087 icmp6len += optlen;
1088 bzero((caddr_t)nd_opt, optlen);
1089 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1090 nd_opt->nd_opt_len = optlen >> 3;
1091 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1092 } else
1093 flags &= ~ND_NA_FLAG_OVERRIDE;
1094
1095 ip6->ip6_plen = htons((u_short)icmp6len);
1096 nd_na->nd_na_flags_reserved = flags;
1097 nd_na->nd_na_cksum = 0;
1098 nd_na->nd_na_cksum =
1099 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1100
1101 if (send_sendso_input_hook != NULL) {
1102 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1103 sizeof(unsigned short), M_NOWAIT);
1104 if (mtag == NULL)
1105 goto bad;
1106 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1107 m_tag_prepend(m, mtag);
1108 }
1109
1110 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1111 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1112 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1113 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1114
1115 return;
1116
1117 bad:
1118 m_freem(m);
1119 }
1120
1121 #ifndef BURN_BRIDGES
1122 void
1123 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1124 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1125 struct sockaddr *sdl0)
1126 {
1127
1128 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1129 RT_DEFAULT_FIB);
1130 }
1131 #endif
1132
1133 caddr_t
1134 nd6_ifptomac(struct ifnet *ifp)
1135 {
1136 switch (ifp->if_type) {
1137 case IFT_ETHER:
1138 case IFT_IEEE1394:
1139 case IFT_L2VLAN:
1140 case IFT_INFINIBAND:
1141 case IFT_BRIDGE:
1142 return IF_LLADDR(ifp);
1143 default:
1144 return NULL;
1145 }
1146 }
1147
1148 struct dadq {
1149 TAILQ_ENTRY(dadq) dad_list;
1150 struct ifaddr *dad_ifa;
1151 int dad_count; /* max NS to send */
1152 int dad_ns_tcount; /* # of trials to send NS */
1153 int dad_ns_ocount; /* NS sent so far */
1154 int dad_ns_icount;
1155 int dad_na_icount;
1156 int dad_ns_lcount; /* looped back NS */
1157 int dad_loopbackprobe; /* probing state for loopback detection */
1158 struct callout dad_timer_ch;
1159 struct vnet *dad_vnet;
1160 u_int dad_refcnt;
1161 #define ND_OPT_NONCE_LEN32 \
1162 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1163 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1164 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */
1165 };
1166
1167 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq);
1168 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock);
1169 #define V_dadq VNET(dadq)
1170 #define V_dad_rwlock VNET(dad_rwlock)
1171
1172 #define DADQ_LOCKPTR() (&V_dad_rwlock)
1173 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue")
1174 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR())
1175 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR())
1176 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR())
1177 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR())
1178
1179 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED);
1180 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED);
1181 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED);
1182
1183 static void
1184 nd6_dad_add(struct dadq *dp)
1185 {
1186 DADQ_WLOCK_ASSERT();
1187
1188 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1189 dp->dad_ondadq = true;
1190 }
1191
1192 static void
1193 nd6_dad_del(struct dadq *dp)
1194 {
1195 DADQ_WLOCK_ASSERT();
1196
1197 if (dp->dad_ondadq) {
1198 /*
1199 * Remove dp from the dadq and release the dadq's
1200 * reference.
1201 */
1202 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1203 dp->dad_ondadq = false;
1204 nd6_dad_rele(dp);
1205 }
1206 }
1207
1208 static struct dadq *
1209 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
1210 {
1211 struct dadq *dp;
1212
1213 DADQ_LOCK_ASSERT();
1214
1215 TAILQ_FOREACH(dp, &V_dadq, dad_list) {
1216 if (dp->dad_ifa != ifa)
1217 continue;
1218
1219 /*
1220 * Skip if the nonce matches the received one.
1221 * +2 in the length is required because of type and
1222 * length fields are included in a header.
1223 */
1224 if (n != NULL &&
1225 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
1226 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
1227 ND_OPT_NONCE_LEN) == 0) {
1228 dp->dad_ns_lcount++;
1229 continue;
1230 }
1231 break;
1232 }
1233
1234 return (dp);
1235 }
1236
1237 static void
1238 nd6_dad_starttimer(struct dadq *dp, int ticks)
1239 {
1240 DADQ_WLOCK_ASSERT();
1241
1242 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp);
1243 }
1244
1245 static void
1246 nd6_dad_stoptimer(struct dadq *dp)
1247 {
1248 callout_drain(&dp->dad_timer_ch);
1249 }
1250
1251 static void
1252 nd6_dad_rele(struct dadq *dp)
1253 {
1254 if (refcount_release(&dp->dad_refcnt)) {
1255 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp));
1256 ifa_free(dp->dad_ifa);
1257 free(dp, M_IP6NDP);
1258 }
1259 }
1260
1261 void
1262 nd6_dad_init(void)
1263 {
1264 DADQ_LOCK_INIT();
1265 TAILQ_INIT(&V_dadq);
1266 }
1267
1268 /*
1269 * Start Duplicate Address Detection (DAD) for specified interface address.
1270 */
1271 void
1272 nd6_dad_start(struct ifaddr *ifa, int delay)
1273 {
1274 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1275 struct dadq *dp;
1276 char ip6buf[INET6_ADDRSTRLEN];
1277
1278 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0,
1279 ("starting DAD on non-tentative address %p", ifa));
1280
1281 /*
1282 * If we don't need DAD, don't do it.
1283 * There are several cases:
1284 * - DAD is disabled globally or on the interface
1285 * - the interface address is anycast
1286 */
1287 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 ||
1288 V_ip6_dad_count == 0 ||
1289 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) {
1290 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1291 return;
1292 }
1293 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 ||
1294 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1295 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0)
1296 return;
1297
1298 DADQ_WLOCK();
1299 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1300 /*
1301 * DAD is already in progress. Let the existing entry
1302 * finish it.
1303 */
1304 DADQ_WUNLOCK();
1305 return;
1306 }
1307
1308 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1309 if (dp == NULL) {
1310 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1311 "%s(%s)\n",
1312 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1313 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1314 return;
1315 }
1316 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(),
1317 CALLOUT_RETURNUNLOCKED);
1318 #ifdef VIMAGE
1319 dp->dad_vnet = curvnet;
1320 #endif
1321 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1322 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1323
1324 /*
1325 * Send NS packet for DAD, ip6_dad_count times.
1326 * Note that we must delay the first transmission, if this is the
1327 * first packet to be sent from the interface after interface
1328 * (re)initialization.
1329 */
1330 dp->dad_ifa = ifa;
1331 ifa_ref(dp->dad_ifa);
1332 dp->dad_count = V_ip6_dad_count;
1333 dp->dad_ns_icount = dp->dad_na_icount = 0;
1334 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1335 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1336
1337 /* Add this to the dadq and add a reference for the dadq. */
1338 refcount_init(&dp->dad_refcnt, 1);
1339 nd6_dad_add(dp);
1340 nd6_dad_starttimer(dp, delay);
1341 DADQ_WUNLOCK();
1342 }
1343
1344 /*
1345 * terminate DAD unconditionally. used for address removals.
1346 */
1347 void
1348 nd6_dad_stop(struct ifaddr *ifa)
1349 {
1350 struct dadq *dp;
1351
1352 DADQ_WLOCK();
1353 dp = nd6_dad_find(ifa, NULL);
1354 if (dp == NULL) {
1355 DADQ_WUNLOCK();
1356 /* DAD wasn't started yet */
1357 return;
1358 }
1359
1360 /*
1361 * Acquire a temporary reference so that we can safely stop the callout.
1362 */
1363 (void)refcount_acquire(&dp->dad_refcnt);
1364 nd6_dad_del(dp);
1365 DADQ_WUNLOCK();
1366
1367 nd6_dad_stoptimer(dp);
1368 nd6_dad_rele(dp);
1369 }
1370
1371 static void
1372 nd6_dad_timer(void *arg)
1373 {
1374 struct dadq *dp = arg;
1375 struct ifaddr *ifa = dp->dad_ifa;
1376 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1377 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1378 char ip6buf[INET6_ADDRSTRLEN];
1379 struct epoch_tracker et;
1380
1381 CURVNET_SET(dp->dad_vnet);
1382 KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
1383
1384 NET_EPOCH_ENTER(et);
1385 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
1386 /* Do not need DAD for ifdisabled interface. */
1387 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1388 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1389 goto err;
1390 }
1391 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1392 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1393 "%s(%s)\n",
1394 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1395 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1396 goto err;
1397 }
1398 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1399 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1400 "%s(%s)\n",
1401 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1402 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1403 goto err;
1404 }
1405
1406 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1407 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1408 (((ifp->if_flags & IFF_UP) == 0) ||
1409 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1410 nd6log((LOG_INFO, "%s: could not run DAD "
1411 "because the interface was down or not running.\n",
1412 if_name(ifa->ifa_ifp)));
1413 goto err;
1414 }
1415
1416 /* Need more checks? */
1417 if (dp->dad_ns_ocount < dp->dad_count) {
1418 /*
1419 * We have more NS to go. Send NS packet for DAD.
1420 */
1421 nd6_dad_starttimer(dp,
1422 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1423 nd6_dad_ns_output(dp);
1424 goto done;
1425 } else {
1426 /*
1427 * We have transmitted sufficient number of DAD packets.
1428 * See what we've got.
1429 */
1430 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) {
1431 /* We've seen NS or NA, means DAD has failed. */
1432 nd6_dad_duplicated(ifa, dp);
1433 } else if (V_dad_enhanced != 0 &&
1434 dp->dad_ns_lcount > 0 &&
1435 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1436 /*
1437 * Sec. 4.1 in RFC 7527 requires transmission of
1438 * additional probes until the loopback condition
1439 * becomes clear when a looped back probe is detected.
1440 */
1441 log(LOG_ERR, "%s: a looped back NS message is "
1442 "detected during DAD for %s. "
1443 "Another DAD probes are being sent.\n",
1444 if_name(ifa->ifa_ifp),
1445 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1446 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1447 /*
1448 * Send an NS immediately and increase dad_count by
1449 * V_nd6_mmaxtries - 1.
1450 */
1451 dp->dad_count =
1452 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1453 nd6_dad_starttimer(dp,
1454 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000);
1455 nd6_dad_ns_output(dp);
1456 goto done;
1457 } else {
1458 /*
1459 * We are done with DAD. No NA came, no NS came.
1460 * No duplicate address found. Check IFDISABLED flag
1461 * again in case that it is changed between the
1462 * beginning of this function and here.
1463 */
1464 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
1465 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1466
1467 nd6log((LOG_DEBUG,
1468 "%s: DAD complete for %s - no duplicates found\n",
1469 if_name(ifa->ifa_ifp),
1470 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1471 if (dp->dad_ns_lcount > 0)
1472 log(LOG_ERR, "%s: DAD completed while "
1473 "a looped back NS message is detected "
1474 "during DAD for %s.\n",
1475 if_name(ifa->ifa_ifp),
1476 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1477 }
1478 }
1479 err:
1480 nd6_dad_del(dp);
1481 DADQ_WUNLOCK();
1482 done:
1483 NET_EPOCH_EXIT(et);
1484 CURVNET_RESTORE();
1485 }
1486
1487 static void
1488 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1489 {
1490 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1491 struct ifnet *ifp;
1492 char ip6buf[INET6_ADDRSTRLEN];
1493
1494 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1495 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1496 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1497 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1498 dp->dad_na_icount);
1499
1500 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1501 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1502
1503 ifp = ifa->ifa_ifp;
1504 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1505 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1506 log(LOG_ERR, "%s: manual intervention required\n",
1507 if_name(ifp));
1508
1509 /*
1510 * If the address is a link-local address formed from an interface
1511 * identifier based on the hardware address which is supposed to be
1512 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1513 * operation on the interface SHOULD be disabled.
1514 * [RFC 4862, Section 5.4.5]
1515 */
1516 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1517 struct in6_addr in6;
1518
1519 /*
1520 * To avoid over-reaction, we only apply this logic when we are
1521 * very sure that hardware addresses are supposed to be unique.
1522 */
1523 switch (ifp->if_type) {
1524 case IFT_ETHER:
1525 case IFT_ATM:
1526 case IFT_IEEE1394:
1527 case IFT_INFINIBAND:
1528 in6 = ia->ia_addr.sin6_addr;
1529 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1530 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1531 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1532 log(LOG_ERR, "%s: possible hardware address "
1533 "duplication detected, disable IPv6\n",
1534 if_name(ifp));
1535 }
1536 break;
1537 }
1538 }
1539 }
1540
1541 /*
1542 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the
1543 * DAD queue unlocked.
1544 */
1545 static void
1546 nd6_dad_ns_output(struct dadq *dp)
1547 {
1548 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1549 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1550 int i;
1551
1552 DADQ_WLOCK_ASSERT();
1553
1554 dp->dad_ns_tcount++;
1555 if ((ifp->if_flags & IFF_UP) == 0) {
1556 DADQ_WUNLOCK();
1557 return;
1558 }
1559 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1560 DADQ_WUNLOCK();
1561 return;
1562 }
1563
1564 dp->dad_ns_ocount++;
1565 if (V_dad_enhanced != 0) {
1566 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1567 dp->dad_nonce[i] = arc4random();
1568 /*
1569 * XXXHRS: Note that in the case that
1570 * DupAddrDetectTransmits > 1, multiple NS messages with
1571 * different nonces can be looped back in an unexpected
1572 * order. The current implementation recognizes only
1573 * the latest nonce on the sender side. Practically it
1574 * should work well in almost all cases.
1575 */
1576 }
1577 DADQ_WUNLOCK();
1578 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1579 (uint8_t *)&dp->dad_nonce[0]);
1580 }
1581
1582 static void
1583 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1584 {
1585 struct dadq *dp;
1586
1587 if (ifa == NULL)
1588 panic("ifa == NULL in nd6_dad_ns_input");
1589
1590 /* Ignore Nonce option when Enhanced DAD is disabled. */
1591 if (V_dad_enhanced == 0)
1592 ndopt_nonce = NULL;
1593 DADQ_RLOCK();
1594 dp = nd6_dad_find(ifa, ndopt_nonce);
1595 if (dp != NULL)
1596 dp->dad_ns_icount++;
1597 DADQ_RUNLOCK();
1598 }
1599
1600 static void
1601 nd6_dad_na_input(struct ifaddr *ifa)
1602 {
1603 struct dadq *dp;
1604
1605 if (ifa == NULL)
1606 panic("ifa == NULL in nd6_dad_na_input");
1607
1608 DADQ_RLOCK();
1609 dp = nd6_dad_find(ifa, NULL);
1610 if (dp != NULL)
1611 dp->dad_na_icount++;
1612 DADQ_RUNLOCK();
1613 }
Cache object: 4fdea900e841dcafebeaf9d71fbe669a
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