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 "opt_inet.h"
35 #include "opt_inet6.h"
36 #include "opt_ipsec.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/counter.h>
41 #include <sys/eventhandler.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/if_private.h>
63 #include <net/route.h>
64 #include <net/vnet.h>
65
66 #include <netinet/in.h>
67 #include <netinet/in_var.h>
68 #include <net/if_llatbl.h>
69 #include <netinet6/in6_var.h>
70 #include <netinet6/in6_ifattach.h>
71 #include <netinet/ip6.h>
72 #include <netinet6/ip6_var.h>
73 #include <netinet6/scope6_var.h>
74 #include <netinet6/nd6.h>
75 #include <netinet/icmp6.h>
76 #include <netinet/ip_carp.h>
77 #include <netinet6/send.h>
78
79 #include <machine/atomic.h>
80
81 #define SDL(s) ((struct sockaddr_dl *)s)
82
83 MALLOC_DECLARE(M_IP6NDP);
84
85 struct dadq;
86 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *);
87 static void nd6_dad_add(struct dadq *dp);
88 static void nd6_dad_del(struct dadq *dp);
89 static void nd6_dad_rele(struct dadq *);
90 static void nd6_dad_starttimer(struct dadq *, int);
91 static void nd6_dad_stoptimer(struct dadq *);
92 static void nd6_dad_timer(void *);
93 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *);
94 static void nd6_dad_ns_output(struct dadq *);
95 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *);
96 static void nd6_dad_na_input(struct ifaddr *);
97 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
98 const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
99 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *,
100 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int);
101 static void nd6_queue_add(struct ifaddr *, struct in6_addr *, int, uint32_t);
102
103 static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *,
104 const struct in6_addr *, struct sockaddr_dl *);
105
106 VNET_DEFINE_STATIC(int, dad_enhanced) = 1;
107 #define V_dad_enhanced VNET(dad_enhanced)
108
109 SYSCTL_DECL(_net_inet6_ip6);
110 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
111 &VNET_NAME(dad_enhanced), 0,
112 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
113
114 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to
115 transmit DAD packet */
116 #define V_dad_maxtry VNET(dad_maxtry)
117
118 VNET_DEFINE_STATIC(int, nd6_onlink_ns_rfc4861) = 0;
119 #define V_nd6_onlink_ns_rfc4861 VNET(nd6_onlink_ns_rfc4861)
120 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_ONLINKNSRFC4861,
121 nd6_onlink_ns_rfc4861, CTLFLAG_VNET | CTLFLAG_RW,
122 &VNET_NAME(nd6_onlink_ns_rfc4861), 0,
123 "Accept 'on-link' ICMPv6 NS messages in compliance with RFC 4861");
124
125 struct nd_queue {
126 TAILQ_ENTRY(nd_queue) ndq_list;
127 struct ifaddr *ndq_ifa;
128 struct in6_addr ndq_daddr;
129 uint32_t ndq_flags;
130 struct callout ndq_callout;
131 };
132
133 /*
134 * Input a Neighbor Solicitation Message.
135 *
136 * Based on RFC 2461
137 * Based on RFC 2462 (duplicate address detection)
138 */
139 void
nd6_ns_input(struct mbuf * m,int off,int icmp6len)140 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
141 {
142 struct ifnet *ifp;
143 struct ip6_hdr *ip6;
144 struct nd_neighbor_solicit *nd_ns;
145 struct in6_addr daddr6, myaddr6, saddr6, taddr6;
146 struct ifaddr *ifa;
147 struct sockaddr_dl proxydl;
148 union nd_opts ndopts;
149 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
150 char *lladdr;
151 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr;
152
153 ifa = NULL;
154
155 /* RFC 6980: Nodes MUST silently ignore fragments */
156 if(m->m_flags & M_FRAGMENTED)
157 goto freeit;
158
159 ifp = m->m_pkthdr.rcvif;
160 ip6 = mtod(m, struct ip6_hdr *);
161 if (__predict_false(ip6->ip6_hlim != 255)) {
162 ICMP6STAT_INC(icp6s_invlhlim);
163 nd6log((LOG_ERR,
164 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
165 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
166 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
167 goto bads;
168 }
169
170 if (m->m_len < off + icmp6len) {
171 m = m_pullup(m, off + icmp6len);
172 if (m == NULL) {
173 IP6STAT_INC(ip6s_exthdrtoolong);
174 return;
175 }
176 }
177 ip6 = mtod(m, struct ip6_hdr *);
178 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
179
180 saddr6 = ip6->ip6_src;
181 daddr6 = ip6->ip6_dst;
182 taddr6 = nd_ns->nd_ns_target;
183 if (in6_setscope(&taddr6, ifp, NULL) != 0)
184 goto bad;
185
186 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
187 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
188 rflag = 0;
189
190 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
191 /* dst has to be a solicited node multicast address. */
192 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
193 /* don't check ifindex portion */
194 daddr6.s6_addr32[1] == 0 &&
195 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
196 daddr6.s6_addr8[12] == 0xff) {
197 ; /* good */
198 } else {
199 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
200 "(wrong ip6 dst)\n"));
201 goto bad;
202 }
203 } else if (!V_nd6_onlink_ns_rfc4861) {
204 struct sockaddr_in6 src_sa6;
205
206 /*
207 * According to recent IETF discussions, it is not a good idea
208 * to accept a NS from an address which would not be deemed
209 * to be a neighbor otherwise. This point is expected to be
210 * clarified in future revisions of the specification.
211 */
212 bzero(&src_sa6, sizeof(src_sa6));
213 src_sa6.sin6_family = AF_INET6;
214 src_sa6.sin6_len = sizeof(src_sa6);
215 src_sa6.sin6_addr = saddr6;
216 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
217 nd6log((LOG_INFO, "nd6_ns_input: "
218 "NS packet from non-neighbor\n"));
219 goto bad;
220 }
221 }
222
223 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
224 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
225 goto bad;
226 }
227
228 icmp6len -= sizeof(*nd_ns);
229 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
230 if (nd6_options(&ndopts) < 0) {
231 nd6log((LOG_INFO,
232 "nd6_ns_input: invalid ND option, ignored\n"));
233 /* nd6_options have incremented stats */
234 goto freeit;
235 }
236
237 lladdr = NULL;
238 lladdrlen = 0;
239 if (ndopts.nd_opts_src_lladdr) {
240 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
241 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
242 }
243
244 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
245 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
246 "(link-layer address option)\n"));
247 goto bad;
248 }
249
250 /*
251 * Attaching target link-layer address to the NA?
252 * (RFC 2461 7.2.4)
253 *
254 * NS IP dst is unicast/anycast MUST NOT add
255 * NS IP dst is solicited-node multicast MUST add
256 *
257 * In implementation, we add target link-layer address by default.
258 * We do not add one in MUST NOT cases.
259 */
260 tlladdr = 0;
261 if (IN6_IS_ADDR_MULTICAST(&daddr6))
262 tlladdr |= ND6_NA_OPT_LLA;
263
264 /*
265 * Target address (taddr6) must be either:
266 * (1) Valid unicast/anycast address for my receiving interface,
267 * (2) Unicast address for which I'm offering proxy service, or
268 * (3) "tentative" address on which DAD is being performed.
269 */
270 /* (1) and (3) check. */
271 if (ifp->if_carp) {
272 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
273 if (ifa != NULL)
274 tlladdr |= ND6_NA_CARP_MASTER;
275 } else
276 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
277
278 /* (2) check. */
279 proxy = 0;
280 if (ifa == NULL) {
281 if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL)
282 proxy = 1;
283 }
284 if (ifa == NULL) {
285 /*
286 * We've got an NS packet, and we don't have that address
287 * assigned for us. We MUST silently ignore it.
288 * See RFC2461 7.2.3.
289 */
290 goto freeit;
291 }
292 myaddr6 = *IFA_IN6(ifa);
293 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
294 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
295 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
296 goto freeit;
297
298 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
299 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
300 "(if %d, NS packet %d)\n",
301 ip6_sprintf(ip6bufs, &taddr6),
302 ifp->if_addrlen, lladdrlen - 2));
303 goto bad;
304 }
305
306 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
307 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
308 ip6_sprintf(ip6bufs, &saddr6)));
309 goto freeit;
310 }
311
312 /*
313 * We have neighbor solicitation packet, with target address equals to
314 * one of my tentative address.
315 *
316 * src addr how to process?
317 * --- ---
318 * multicast of course, invalid (rejected in ip6_input)
319 * unicast somebody is doing address resolution -> ignore
320 * unspec dup address detection
321 *
322 * The processing is defined in RFC 2462.
323 */
324 if (tentative) {
325 /*
326 * If source address is unspecified address, it is for
327 * duplicate address detection.
328 *
329 * If not, the packet is for addess resolution;
330 * silently ignore it.
331 */
332 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
333 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
334
335 goto freeit;
336 }
337
338 /*
339 * If the Target Address is either an anycast address or a unicast
340 * address for which the node is providing proxy service, or the Target
341 * Link-Layer Address option is not included, the Override flag SHOULD
342 * be set to zero. Otherwise, the Override flag SHOULD be set to one.
343 */
344 if (anycast == 0 && proxy == 0 && (tlladdr & ND6_NA_OPT_LLA) != 0)
345 rflag |= ND_NA_FLAG_OVERRIDE;
346 /*
347 * If the source address is unspecified address, entries must not
348 * be created or updated.
349 * It looks that sender is performing DAD. nd6_na_output() will
350 * send NA toward all-node multicast address, to tell the sender
351 * that I'm using the address.
352 * S bit ("solicited") must be zero.
353 */
354 if (!IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
355 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
356 ND_NEIGHBOR_SOLICIT, 0);
357 rflag |= ND_NA_FLAG_SOLICITED;
358 }
359
360 /*
361 * RFC 4861, anycast or proxy NA sent in response to a NS SHOULD
362 * be delayed by a random time between 0 and MAX_ANYCAST_DELAY_TIME
363 * to reduce the probability of network congestion.
364 */
365 if (anycast == 0)
366 nd6_na_output_fib(ifp, &saddr6, &taddr6, rflag, tlladdr,
367 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
368 else
369 nd6_queue_add(ifa, &saddr6, arc4random() %
370 (MAX_ANYCAST_DELAY_TIME * hz), ND6_QUEUE_FLAG_ANYCAST);
371 freeit:
372 if (ifa != NULL)
373 ifa_free(ifa);
374 m_freem(m);
375 return;
376
377 bad:
378 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
379 ip6_sprintf(ip6bufs, &saddr6)));
380 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
381 ip6_sprintf(ip6bufs, &daddr6)));
382 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
383 ip6_sprintf(ip6bufs, &taddr6)));
384 bads:
385 ICMP6STAT_INC(icp6s_badns);
386 if (ifa != NULL)
387 ifa_free(ifa);
388 m_freem(m);
389 }
390
391 static struct ifaddr *
nd6_proxy_fill_sdl(struct ifnet * ifp,const struct in6_addr * taddr6,struct sockaddr_dl * sdl)392 nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6,
393 struct sockaddr_dl *sdl)
394 {
395 struct ifaddr *ifa;
396 struct llentry *ln;
397
398 ifa = NULL;
399 ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp);
400 if (ln == NULL)
401 return (ifa);
402 if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) {
403 link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type);
404 sdl->sdl_alen = ifp->if_addrlen;
405 bcopy(ln->ll_addr, &sdl->sdl_data, ifp->if_addrlen);
406 LLE_RUNLOCK(ln);
407 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
408 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
409 } else
410 LLE_RUNLOCK(ln);
411
412 return (ifa);
413 }
414
415 /*
416 * Output a Neighbor Solicitation Message. Caller specifies:
417 * - ICMP6 header source IP6 address
418 * - ND6 header target IP6 address
419 * - ND6 header source datalink address
420 *
421 * Based on RFC 2461
422 * Based on RFC 2462 (duplicate address detection)
423 *
424 * ln - for source address determination
425 * nonce - If non-NULL, NS is used for duplicate address detection and
426 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
427 */
428 static void
nd6_ns_output_fib(struct ifnet * ifp,const struct in6_addr * saddr6,const struct in6_addr * daddr6,const struct in6_addr * taddr6,uint8_t * nonce,u_int fibnum)429 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
430 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
431 uint8_t *nonce, u_int fibnum)
432 {
433 struct mbuf *m;
434 struct m_tag *mtag;
435 struct ip6_hdr *ip6;
436 struct nd_neighbor_solicit *nd_ns;
437 struct ip6_moptions im6o;
438 int icmp6len;
439 int maxlen;
440
441 NET_EPOCH_ASSERT();
442
443 if (IN6_IS_ADDR_MULTICAST(taddr6))
444 return;
445
446 /* estimate the size of message */
447 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
448 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
449 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
450 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
451 __func__, max_linkhdr, maxlen, MCLBYTES));
452
453 if (max_linkhdr + maxlen > MHLEN)
454 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
455 else
456 m = m_gethdr(M_NOWAIT, MT_DATA);
457 if (m == NULL)
458 return;
459 M_SETFIB(m, fibnum);
460
461 icmp6len = sizeof(*nd_ns);
462 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
463 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
464
465 /* fill neighbor solicitation packet */
466 ip6 = mtod(m, struct ip6_hdr *);
467 ip6->ip6_flow = 0;
468 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
469 ip6->ip6_vfc |= IPV6_VERSION;
470 /* ip6->ip6_plen will be set later */
471 ip6->ip6_nxt = IPPROTO_ICMPV6;
472 ip6->ip6_hlim = 255;
473 if (daddr6)
474 ip6->ip6_dst = *daddr6;
475 else {
476 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
477 ip6->ip6_dst.s6_addr16[1] = 0;
478 ip6->ip6_dst.s6_addr32[1] = 0;
479 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
480 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
481 ip6->ip6_dst.s6_addr8[12] = 0xff;
482 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
483 goto bad;
484 }
485 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
486 m->m_flags |= M_MCAST;
487 im6o.im6o_multicast_ifp = ifp;
488 im6o.im6o_multicast_hlim = 255;
489 im6o.im6o_multicast_loop = 0;
490 }
491 if (nonce == NULL) {
492 char ip6buf[INET6_ADDRSTRLEN];
493 struct ifaddr *ifa = NULL;
494
495 /*
496 * RFC2461 7.2.2:
497 * "If the source address of the packet prompting the
498 * solicitation is the same as one of the addresses assigned
499 * to the outgoing interface, that address SHOULD be placed
500 * in the IP Source Address of the outgoing solicitation.
501 * Otherwise, any one of the addresses assigned to the
502 * interface should be used."
503 *
504 * We use the source address for the prompting packet
505 * (saddr6), if saddr6 belongs to the outgoing interface.
506 * Otherwise, we perform the source address selection as usual.
507 */
508 if (saddr6 != NULL)
509 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
510 if (ifa == NULL) {
511 int error;
512
513 error = in6_selectsrc_nbr(fibnum, &ip6->ip6_dst, &im6o,
514 ifp, &ip6->ip6_src);
515 if (error) {
516 nd6log((LOG_DEBUG, "%s: source can't be "
517 "determined: dst=%s, error=%d\n", __func__,
518 ip6_sprintf(ip6buf, &ip6->ip6_dst),
519 error));
520 goto bad;
521 }
522 } else
523 ip6->ip6_src = *saddr6;
524
525 if (ifp->if_carp != NULL) {
526 /*
527 * Check that selected source address belongs to
528 * CARP addresses.
529 */
530 if (ifa == NULL)
531 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
532 &ip6->ip6_src);
533 /*
534 * Do not send NS for CARP address if we are not
535 * the CARP master.
536 */
537 if (ifa != NULL && ifa->ifa_carp != NULL &&
538 !(*carp_master_p)(ifa)) {
539 nd6log((LOG_DEBUG,
540 "nd6_ns_output: NS from BACKUP CARP address %s\n",
541 ip6_sprintf(ip6buf, &ip6->ip6_src)));
542 ifa_free(ifa);
543 goto bad;
544 }
545 }
546 if (ifa != NULL)
547 ifa_free(ifa);
548 } else {
549 /*
550 * Source address for DAD packet must always be IPv6
551 * unspecified address. (0::0)
552 * We actually don't have to 0-clear the address (we did it
553 * above), but we do so here explicitly to make the intention
554 * clearer.
555 */
556 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
557 }
558 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
559 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
560 nd_ns->nd_ns_code = 0;
561 nd_ns->nd_ns_reserved = 0;
562 nd_ns->nd_ns_target = *taddr6;
563 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
564
565 /*
566 * Add source link-layer address option.
567 *
568 * spec implementation
569 * --- ---
570 * DAD packet MUST NOT do not add the option
571 * there's no link layer address:
572 * impossible do not add the option
573 * there's link layer address:
574 * Multicast NS MUST add one add the option
575 * Unicast NS SHOULD add one add the option
576 */
577 if (nonce == NULL) {
578 struct nd_opt_hdr *nd_opt;
579 char *mac;
580 int optlen;
581
582 mac = NULL;
583 if (ifp->if_carp)
584 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src);
585 if (mac == NULL)
586 mac = nd6_ifptomac(ifp);
587
588 if (mac != NULL) {
589 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
590 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
591 /* 8 byte alignments... */
592 optlen = (optlen + 7) & ~7;
593 m->m_pkthdr.len += optlen;
594 m->m_len += optlen;
595 icmp6len += optlen;
596 bzero(nd_opt, optlen);
597 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
598 nd_opt->nd_opt_len = optlen >> 3;
599 bcopy(mac, nd_opt + 1, ifp->if_addrlen);
600 }
601 }
602 /*
603 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
604 * This behavior is documented as Enhanced Duplicate Address
605 * Detection in RFC 7527.
606 * net.inet6.ip6.dad_enhanced=0 disables this.
607 */
608 if (V_dad_enhanced != 0 && nonce != NULL) {
609 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
610 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
611 /* 8-byte alignment is required. */
612 optlen = (optlen + 7) & ~7;
613
614 m->m_pkthdr.len += optlen;
615 m->m_len += optlen;
616 icmp6len += optlen;
617 bzero((caddr_t)nd_opt, optlen);
618 nd_opt->nd_opt_type = ND_OPT_NONCE;
619 nd_opt->nd_opt_len = optlen >> 3;
620 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
621 }
622 ip6->ip6_plen = htons((u_short)icmp6len);
623 nd_ns->nd_ns_cksum = 0;
624 nd_ns->nd_ns_cksum =
625 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
626
627 if (send_sendso_input_hook != NULL) {
628 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
629 sizeof(unsigned short), M_NOWAIT);
630 if (mtag == NULL)
631 goto bad;
632 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
633 m_tag_prepend(m, mtag);
634 }
635
636 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
637 &im6o, NULL, NULL);
638 icmp6_ifstat_inc(ifp, ifs6_out_msg);
639 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
640 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_SOLICIT);
641
642 return;
643
644 bad:
645 m_freem(m);
646 }
647
648 #ifndef BURN_BRIDGES
649 void
nd6_ns_output(struct ifnet * ifp,const struct in6_addr * saddr6,const struct in6_addr * daddr6,const struct in6_addr * taddr6,uint8_t * nonce)650 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
651 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
652 {
653
654 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
655 }
656 #endif
657 /*
658 * Neighbor advertisement input handling.
659 *
660 * Based on RFC 2461
661 * Based on RFC 2462 (duplicate address detection)
662 */
663 void
nd6_na_input(struct mbuf * m,int off,int icmp6len)664 nd6_na_input(struct mbuf *m, int off, int icmp6len)
665 {
666 struct ifnet *ifp;
667 struct ip6_hdr *ip6;
668 struct ifaddr *ifa;
669 struct llentry *ln;
670 struct mbuf *chain;
671 struct nd_neighbor_advert *nd_na;
672 struct in6_addr daddr6, taddr6;
673 union nd_opts ndopts;
674 u_char linkhdr[LLE_MAX_LINKHDR];
675 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
676 char *lladdr;
677 size_t linkhdrsize;
678 int flags, is_override, is_router, is_solicited;
679 int lladdr_off, lladdrlen, checklink;
680 bool flush_holdchain = false;
681
682 NET_EPOCH_ASSERT();
683
684 chain = NULL;
685 ln = NULL;
686 checklink = 0;
687
688 /* RFC 6980: Nodes MUST silently ignore fragments */
689 if(m->m_flags & M_FRAGMENTED)
690 goto freeit;
691
692 ifp = m->m_pkthdr.rcvif;
693 ip6 = mtod(m, struct ip6_hdr *);
694 if (__predict_false(ip6->ip6_hlim != 255)) {
695 ICMP6STAT_INC(icp6s_invlhlim);
696 nd6log((LOG_ERR,
697 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
698 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
699 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
700 goto bad;
701 }
702
703 if (m->m_len < off + icmp6len) {
704 m = m_pullup(m, off + icmp6len);
705 if (m == NULL) {
706 IP6STAT_INC(ip6s_exthdrtoolong);
707 return;
708 }
709 }
710 ip6 = mtod(m, struct ip6_hdr *);
711 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
712
713 flags = nd_na->nd_na_flags_reserved;
714 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
715 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
716 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
717
718 taddr6 = nd_na->nd_na_target;
719 if (in6_setscope(&taddr6, ifp, NULL))
720 goto bad; /* XXX: impossible */
721
722 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
723 nd6log((LOG_ERR,
724 "nd6_na_input: invalid target address %s\n",
725 ip6_sprintf(ip6bufs, &taddr6)));
726 goto bad;
727 }
728
729 daddr6 = ip6->ip6_dst;
730 if (IN6_IS_ADDR_MULTICAST(&daddr6))
731 if (is_solicited) {
732 nd6log((LOG_ERR,
733 "nd6_na_input: a solicited adv is multicasted\n"));
734 goto bad;
735 }
736
737 icmp6len -= sizeof(*nd_na);
738 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
739 if (nd6_options(&ndopts) < 0) {
740 nd6log((LOG_INFO,
741 "nd6_na_input: invalid ND option, ignored\n"));
742 /* nd6_options have incremented stats */
743 goto freeit;
744 }
745
746 lladdr = NULL;
747 lladdrlen = 0;
748 if (ndopts.nd_opts_tgt_lladdr) {
749 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
750 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
751 }
752
753 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
754 if (ifa != NULL && ifa->ifa_carp != NULL) {
755 /*
756 * Silently ignore NAs for CARP addresses if we are not
757 * the CARP master.
758 */
759 if (!(*carp_master_p)(ifa)) {
760 nd6log((LOG_DEBUG,
761 "nd6_na_input: NA for BACKUP CARP address %s\n",
762 ip6_sprintf(ip6bufs, &taddr6)));
763 ifa_free(ifa);
764 goto freeit;
765 }
766 }
767 /*
768 * Target address matches one of my interface address.
769 *
770 * If my address is tentative, this means that there's somebody
771 * already using the same address as mine. This indicates DAD failure.
772 * This is defined in RFC 2462.
773 *
774 * Otherwise, process as defined in RFC 2461.
775 */
776 if (ifa
777 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
778 nd6_dad_na_input(ifa);
779 ifa_free(ifa);
780 goto freeit;
781 }
782
783 /* Just for safety, maybe unnecessary. */
784 if (ifa) {
785 ifa_free(ifa);
786 log(LOG_ERR,
787 "nd6_na_input: duplicate IP6 address %s\n",
788 ip6_sprintf(ip6bufs, &taddr6));
789 goto freeit;
790 }
791
792 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
793 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
794 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
795 ifp->if_addrlen, lladdrlen - 2));
796 goto bad;
797 }
798
799 /*
800 * If no neighbor cache entry is found, NA SHOULD silently be
801 * discarded.
802 */
803 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
804 if (ln == NULL) {
805 goto freeit;
806 }
807
808 /*
809 * Do not try to override static entry.
810 */
811 if (ln->la_flags & LLE_STATIC)
812 goto freeit;
813
814 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
815 /*
816 * If the link-layer has address, and no lladdr option came,
817 * discard the packet.
818 */
819 if (ifp->if_addrlen && lladdr == NULL) {
820 goto freeit;
821 }
822
823 /*
824 * Record link-layer address, and update the state.
825 */
826 if (!nd6_try_set_entry_addr(ifp, ln, lladdr))
827 goto freeit;
828
829 flush_holdchain = true;
830 if (is_solicited)
831 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
832 else
833 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
834 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
835 if ((ln->ln_router = is_router) != 0) {
836 /*
837 * This means a router's state has changed from
838 * non-reachable to probably reachable, and might
839 * affect the status of associated prefixes..
840 */
841 checklink = 1;
842 }
843 } else {
844 int llchange;
845
846 /*
847 * Check if the link-layer address has changed or not.
848 */
849 if (lladdr == NULL)
850 llchange = 0;
851 else {
852 if (ln->la_flags & LLE_VALID) {
853 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
854 llchange = 1;
855 else
856 llchange = 0;
857 } else
858 llchange = 1;
859 }
860
861 /*
862 * This is VERY complex. Look at it with care.
863 *
864 * override solicit lladdr llchange action
865 * (L: record lladdr)
866 *
867 * 0 0 n -- (2c)
868 * 0 0 y n (2b) L
869 * 0 0 y y (1) REACHABLE->STALE
870 * 0 1 n -- (2c) *->REACHABLE
871 * 0 1 y n (2b) L *->REACHABLE
872 * 0 1 y y (1) REACHABLE->STALE
873 * 1 0 n -- (2a)
874 * 1 0 y n (2a) L
875 * 1 0 y y (2a) L *->STALE
876 * 1 1 n -- (2a) *->REACHABLE
877 * 1 1 y n (2a) L *->REACHABLE
878 * 1 1 y y (2a) L *->REACHABLE
879 */
880 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
881 /*
882 * If state is REACHABLE, make it STALE.
883 * no other updates should be done.
884 */
885 if (ln->ln_state == ND6_LLINFO_REACHABLE)
886 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
887 goto freeit;
888 } else if (is_override /* (2a) */
889 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
890 || lladdr == NULL) { /* (2c) */
891 /*
892 * Update link-local address, if any.
893 */
894 if (lladdr != NULL) {
895 linkhdrsize = sizeof(linkhdr);
896 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
897 linkhdr, &linkhdrsize, &lladdr_off) != 0)
898 goto freeit;
899 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
900 linkhdrsize, lladdr_off) == 0)
901 goto freeit;
902 EVENTHANDLER_INVOKE(lle_event, ln,
903 LLENTRY_RESOLVED);
904 }
905
906 /*
907 * If solicited, make the state REACHABLE.
908 * If not solicited and the link-layer address was
909 * changed, make it STALE.
910 */
911 if (is_solicited)
912 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
913 else {
914 if (lladdr != NULL && llchange)
915 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
916 }
917 }
918
919 if (ln->ln_router && !is_router) {
920 /*
921 * The peer dropped the router flag.
922 * Remove the sender from the Default Router List and
923 * update the Destination Cache entries.
924 */
925 struct ifnet *nd6_ifp;
926
927 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
928 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
929 (nd6_ifp->if_inet6->nd_flags &
930 ND6_IFF_ACCEPT_RTADV) != 0)
931 /*
932 * Even if the neighbor is not in the default
933 * router list, the neighbor may be used as a
934 * next hop for some destinations (e.g. redirect
935 * case). So we must call rt6_flush explicitly.
936 */
937 rt6_flush(&ip6->ip6_src, ifp);
938 }
939 ln->ln_router = is_router;
940 }
941 /* XXX - QL
942 * Does this matter?
943 * rt->rt_flags &= ~RTF_REJECT;
944 */
945 ln->la_asked = 0;
946 if (ln->la_hold != NULL)
947 chain = nd6_grab_holdchain(ln);
948 freeit:
949 if (ln != NULL)
950 LLE_WUNLOCK(ln);
951
952 if (chain != NULL)
953 nd6_flush_holdchain(ifp, ln, chain);
954 if (flush_holdchain)
955 nd6_flush_children_holdchain(ifp, ln);
956
957 if (checklink)
958 pfxlist_onlink_check();
959
960 m_freem(m);
961 return;
962
963 bad:
964 if (ln != NULL)
965 LLE_WUNLOCK(ln);
966
967 ICMP6STAT_INC(icp6s_badna);
968 m_freem(m);
969 }
970
971 /*
972 * Neighbor advertisement output handling.
973 *
974 * Based on RFC 2461
975 *
976 * tlladdr:
977 * - 0x01 if include target link-layer address
978 * - 0x02 if target address is CARP MASTER
979 * sdl0 - sockaddr_dl (= proxy NA) or NULL
980 */
981 static void
nd6_na_output_fib(struct ifnet * ifp,const struct in6_addr * daddr6_0,const struct in6_addr * taddr6,u_long flags,int tlladdr,struct sockaddr * sdl0,u_int fibnum)982 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
983 const struct in6_addr *taddr6, u_long flags, int tlladdr,
984 struct sockaddr *sdl0, u_int fibnum)
985 {
986 struct mbuf *m;
987 struct m_tag *mtag;
988 struct ip6_hdr *ip6;
989 struct nd_neighbor_advert *nd_na;
990 struct ip6_moptions im6o;
991 struct in6_addr daddr6;
992
993 NET_EPOCH_ASSERT();
994
995 int icmp6len, maxlen, error;
996 caddr_t mac = NULL;
997
998 daddr6 = *daddr6_0; /* make a local copy for modification */
999
1000 /* estimate the size of message */
1001 maxlen = sizeof(*ip6) + sizeof(*nd_na);
1002 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
1003 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
1004 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
1005 __func__, max_linkhdr, maxlen, MCLBYTES));
1006
1007 if (max_linkhdr + maxlen > MHLEN)
1008 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
1009 else
1010 m = m_gethdr(M_NOWAIT, MT_DATA);
1011 if (m == NULL)
1012 return;
1013 M_SETFIB(m, fibnum);
1014
1015 icmp6len = sizeof(*nd_na);
1016 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
1017 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
1018
1019 /* fill neighbor advertisement packet */
1020 ip6 = mtod(m, struct ip6_hdr *);
1021 ip6->ip6_flow = 0;
1022 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1023 ip6->ip6_vfc |= IPV6_VERSION;
1024 ip6->ip6_nxt = IPPROTO_ICMPV6;
1025 ip6->ip6_hlim = 255;
1026
1027 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
1028 /* reply to DAD */
1029 daddr6 = in6addr_linklocal_allnodes;
1030 if (in6_setscope(&daddr6, ifp, NULL))
1031 goto bad;
1032
1033 flags &= ~ND_NA_FLAG_SOLICITED;
1034 }
1035 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
1036 m->m_flags |= M_MCAST;
1037 im6o.im6o_multicast_ifp = ifp;
1038 im6o.im6o_multicast_hlim = 255;
1039 im6o.im6o_multicast_loop = 0;
1040 }
1041
1042 ip6->ip6_dst = daddr6;
1043 error = in6_selectsrc_nbr(fibnum, &daddr6, &im6o, ifp, &ip6->ip6_src);
1044 if (error) {
1045 char ip6buf[INET6_ADDRSTRLEN];
1046 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1047 "determined: dst=%s, error=%d\n",
1048 ip6_sprintf(ip6buf, &daddr6), error));
1049 goto bad;
1050 }
1051 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1052 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1053 nd_na->nd_na_code = 0;
1054 nd_na->nd_na_target = *taddr6;
1055 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1056
1057 /*
1058 * If we respond from CARP address, we need to prepare mac address
1059 * for carp_output().
1060 */
1061 if (ifp->if_carp && (tlladdr & ND6_NA_CARP_MASTER))
1062 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1063 /*
1064 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1065 * see nd6_ns_input() for details.
1066 * Basically, if NS packet is sent to unicast/anycast addr,
1067 * target lladdr option SHOULD NOT be included.
1068 */
1069 if (tlladdr & ND6_NA_OPT_LLA) {
1070 /*
1071 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1072 * lladdr in sdl0. If we are not proxying (sending NA for
1073 * my address) use lladdr configured for the interface.
1074 */
1075 if (sdl0 == NULL) {
1076 if (mac == NULL)
1077 mac = nd6_ifptomac(ifp);
1078 } else if (sdl0->sa_family == AF_LINK) {
1079 struct sockaddr_dl *sdl;
1080 sdl = (struct sockaddr_dl *)sdl0;
1081 if (sdl->sdl_alen == ifp->if_addrlen)
1082 mac = LLADDR(sdl);
1083 }
1084 }
1085 if ((tlladdr & ND6_NA_OPT_LLA) && mac != NULL) {
1086 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1087 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1088
1089 /* roundup to 8 bytes alignment! */
1090 optlen = (optlen + 7) & ~7;
1091
1092 m->m_pkthdr.len += optlen;
1093 m->m_len += optlen;
1094 icmp6len += optlen;
1095 bzero((caddr_t)nd_opt, optlen);
1096 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1097 nd_opt->nd_opt_len = optlen >> 3;
1098 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1099 } else
1100 flags &= ~ND_NA_FLAG_OVERRIDE;
1101
1102 ip6->ip6_plen = htons((u_short)icmp6len);
1103 nd_na->nd_na_flags_reserved = flags;
1104 nd_na->nd_na_cksum = 0;
1105 nd_na->nd_na_cksum =
1106 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1107
1108 if (send_sendso_input_hook != NULL) {
1109 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1110 sizeof(unsigned short), M_NOWAIT);
1111 if (mtag == NULL)
1112 goto bad;
1113 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1114 m_tag_prepend(m, mtag);
1115 }
1116
1117 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1118 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1119 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1120 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_ADVERT);
1121
1122 return;
1123
1124 bad:
1125 m_freem(m);
1126 }
1127
1128 #ifndef BURN_BRIDGES
1129 void
nd6_na_output(struct ifnet * ifp,const struct in6_addr * daddr6_0,const struct in6_addr * taddr6,u_long flags,int tlladdr,struct sockaddr * sdl0)1130 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1131 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1132 struct sockaddr *sdl0)
1133 {
1134
1135 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1136 RT_DEFAULT_FIB);
1137 }
1138 #endif
1139
1140 caddr_t
nd6_ifptomac(struct ifnet * ifp)1141 nd6_ifptomac(struct ifnet *ifp)
1142 {
1143 switch (ifp->if_type) {
1144 case IFT_ETHER:
1145 case IFT_IEEE1394:
1146 case IFT_L2VLAN:
1147 case IFT_INFINIBAND:
1148 case IFT_BRIDGE:
1149 return IF_LLADDR(ifp);
1150 default:
1151 return NULL;
1152 }
1153 }
1154
1155 struct dadq {
1156 TAILQ_ENTRY(dadq) dad_list;
1157 struct ifaddr *dad_ifa;
1158 int dad_count; /* max NS to send */
1159 int dad_ns_tcount; /* # of trials to send NS */
1160 int dad_ns_ocount; /* NS sent so far */
1161 int dad_ns_icount;
1162 int dad_na_icount;
1163 int dad_ns_lcount; /* looped back NS */
1164 int dad_loopbackprobe; /* probing state for loopback detection */
1165 struct callout dad_timer_ch;
1166 struct vnet *dad_vnet;
1167 u_int dad_refcnt;
1168 #define ND_OPT_NONCE_LEN32 \
1169 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1170 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1171 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */
1172 };
1173
1174 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq);
1175 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock);
1176 #define V_dadq VNET(dadq)
1177 #define V_dad_rwlock VNET(dad_rwlock)
1178
1179 #define DADQ_LOCKPTR() (&V_dad_rwlock)
1180 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue")
1181 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR())
1182 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR())
1183 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR())
1184 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR())
1185
1186 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED);
1187 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED);
1188 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED);
1189
1190 static void
nd6_dad_add(struct dadq * dp)1191 nd6_dad_add(struct dadq *dp)
1192 {
1193 DADQ_WLOCK_ASSERT();
1194
1195 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1196 dp->dad_ondadq = true;
1197 }
1198
1199 static void
nd6_dad_del(struct dadq * dp)1200 nd6_dad_del(struct dadq *dp)
1201 {
1202 DADQ_WLOCK_ASSERT();
1203
1204 if (dp->dad_ondadq) {
1205 /*
1206 * Remove dp from the dadq and release the dadq's
1207 * reference.
1208 */
1209 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1210 dp->dad_ondadq = false;
1211 nd6_dad_rele(dp);
1212 }
1213 }
1214
1215 static struct dadq *
nd6_dad_find(struct ifaddr * ifa,struct nd_opt_nonce * n)1216 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
1217 {
1218 struct dadq *dp;
1219
1220 DADQ_LOCK_ASSERT();
1221
1222 TAILQ_FOREACH(dp, &V_dadq, dad_list) {
1223 if (dp->dad_ifa != ifa)
1224 continue;
1225
1226 /*
1227 * Skip if the nonce matches the received one.
1228 * +2 in the length is required because of type and
1229 * length fields are included in a header.
1230 */
1231 if (n != NULL &&
1232 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
1233 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
1234 ND_OPT_NONCE_LEN) == 0) {
1235 dp->dad_ns_lcount++;
1236 continue;
1237 }
1238 break;
1239 }
1240
1241 return (dp);
1242 }
1243
1244 static void
nd6_dad_starttimer(struct dadq * dp,int ticks)1245 nd6_dad_starttimer(struct dadq *dp, int ticks)
1246 {
1247 DADQ_WLOCK_ASSERT();
1248
1249 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp);
1250 }
1251
1252 static void
nd6_dad_stoptimer(struct dadq * dp)1253 nd6_dad_stoptimer(struct dadq *dp)
1254 {
1255 callout_drain(&dp->dad_timer_ch);
1256 }
1257
1258 static void
nd6_dad_rele(struct dadq * dp)1259 nd6_dad_rele(struct dadq *dp)
1260 {
1261 if (refcount_release(&dp->dad_refcnt)) {
1262 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp));
1263 ifa_free(dp->dad_ifa);
1264 free(dp, M_IP6NDP);
1265 }
1266 }
1267
1268 void
nd6_dad_init(void)1269 nd6_dad_init(void)
1270 {
1271 DADQ_LOCK_INIT();
1272 TAILQ_INIT(&V_dadq);
1273 }
1274
1275 /*
1276 * Start Duplicate Address Detection (DAD) for specified interface address.
1277 */
1278 void
nd6_dad_start(struct ifaddr * ifa,int delay)1279 nd6_dad_start(struct ifaddr *ifa, int delay)
1280 {
1281 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1282 struct dadq *dp;
1283 char ip6buf[INET6_ADDRSTRLEN];
1284
1285 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0,
1286 ("starting DAD on non-tentative address %p", ifa));
1287
1288 /*
1289 * If we don't need DAD, don't do it.
1290 * There are several cases:
1291 * - DAD is disabled globally or on the interface
1292 * - the interface address is anycast
1293 */
1294 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 ||
1295 V_ip6_dad_count == 0 ||
1296 (ifa->ifa_ifp->if_inet6->nd_flags & ND6_IFF_NO_DAD) != 0) {
1297 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1298 return;
1299 }
1300 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 ||
1301 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1302 (ifa->ifa_ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) != 0)
1303 return;
1304
1305 DADQ_WLOCK();
1306 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1307 /*
1308 * DAD is already in progress. Let the existing entry
1309 * finish it.
1310 */
1311 DADQ_WUNLOCK();
1312 return;
1313 }
1314
1315 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1316 if (dp == NULL) {
1317 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1318 "%s(%s)\n",
1319 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1320 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1321 return;
1322 }
1323 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(),
1324 CALLOUT_RETURNUNLOCKED);
1325 #ifdef VIMAGE
1326 dp->dad_vnet = curvnet;
1327 #endif
1328 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1329 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1330
1331 /*
1332 * Send NS packet for DAD, ip6_dad_count times.
1333 * Note that we must delay the first transmission, if this is the
1334 * first packet to be sent from the interface after interface
1335 * (re)initialization.
1336 */
1337 dp->dad_ifa = ifa;
1338 ifa_ref(dp->dad_ifa);
1339 dp->dad_count = V_ip6_dad_count;
1340 dp->dad_ns_icount = dp->dad_na_icount = 0;
1341 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1342 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1343
1344 /* Add this to the dadq and add a reference for the dadq. */
1345 refcount_init(&dp->dad_refcnt, 1);
1346 nd6_dad_add(dp);
1347 nd6_dad_starttimer(dp, delay);
1348 DADQ_WUNLOCK();
1349 }
1350
1351 /*
1352 * terminate DAD unconditionally. used for address removals.
1353 */
1354 void
nd6_dad_stop(struct ifaddr * ifa)1355 nd6_dad_stop(struct ifaddr *ifa)
1356 {
1357 struct dadq *dp;
1358
1359 DADQ_WLOCK();
1360 dp = nd6_dad_find(ifa, NULL);
1361 if (dp == NULL) {
1362 DADQ_WUNLOCK();
1363 /* DAD wasn't started yet */
1364 return;
1365 }
1366
1367 /*
1368 * Acquire a temporary reference so that we can safely stop the callout.
1369 */
1370 (void)refcount_acquire(&dp->dad_refcnt);
1371 nd6_dad_del(dp);
1372 DADQ_WUNLOCK();
1373
1374 nd6_dad_stoptimer(dp);
1375 nd6_dad_rele(dp);
1376 }
1377
1378 static void
nd6_dad_timer(void * arg)1379 nd6_dad_timer(void *arg)
1380 {
1381 struct dadq *dp = arg;
1382 struct ifaddr *ifa = dp->dad_ifa;
1383 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1384 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1385 char ip6buf[INET6_ADDRSTRLEN];
1386 struct epoch_tracker et;
1387
1388 CURVNET_SET(dp->dad_vnet);
1389 KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
1390
1391 NET_EPOCH_ENTER(et);
1392 if (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) {
1393 /* Do not need DAD for ifdisabled interface. */
1394 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1395 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1396 goto err;
1397 }
1398 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1399 log(LOG_ERR, "nd6_dad_timer: called with duplicated 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 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1406 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1407 "%s(%s)\n",
1408 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1409 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1410 goto err;
1411 }
1412
1413 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1414 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1415 (((ifp->if_flags & IFF_UP) == 0) ||
1416 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1417 nd6log((LOG_INFO, "%s: could not run DAD "
1418 "because the interface was down or not running.\n",
1419 if_name(ifa->ifa_ifp)));
1420 goto err;
1421 }
1422
1423 /* Need more checks? */
1424 if (dp->dad_ns_ocount < dp->dad_count) {
1425 /*
1426 * We have more NS to go. Send NS packet for DAD.
1427 */
1428 nd6_dad_starttimer(dp,
1429 (long)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000);
1430 nd6_dad_ns_output(dp);
1431 goto done;
1432 } else {
1433 /*
1434 * We have transmitted sufficient number of DAD packets.
1435 * See what we've got.
1436 */
1437 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) {
1438 /* We've seen NS or NA, means DAD has failed. */
1439 nd6_dad_duplicated(ifa, dp);
1440 } else if (V_dad_enhanced != 0 &&
1441 dp->dad_ns_lcount > 0 &&
1442 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1443 /*
1444 * Sec. 4.1 in RFC 7527 requires transmission of
1445 * additional probes until the loopback condition
1446 * becomes clear when a looped back probe is detected.
1447 */
1448 log(LOG_ERR, "%s: a looped back NS message is "
1449 "detected during DAD for %s. "
1450 "Another DAD probes are being sent.\n",
1451 if_name(ifa->ifa_ifp),
1452 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1453 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1454 /*
1455 * Send an NS immediately and increase dad_count by
1456 * V_nd6_mmaxtries - 1.
1457 */
1458 dp->dad_count =
1459 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1460 nd6_dad_starttimer(dp,
1461 (long)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000);
1462 nd6_dad_ns_output(dp);
1463 goto done;
1464 } else {
1465 /*
1466 * We are done with DAD. No NA came, no NS came.
1467 * No duplicate address found. Check IFDISABLED flag
1468 * again in case that it is changed between the
1469 * beginning of this function and here.
1470 *
1471 * Reset DAD failures counter if using stable addresses.
1472 */
1473 if ((ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) == 0) {
1474 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1475 if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY))
1476 atomic_store_int(&DAD_FAILURES(ifp), 0);
1477 /*
1478 * RFC 9131 Section 6.1.2: The first advertisement
1479 * SHOULD be sent as soon as an address changes the
1480 * state from tentative to preferred.
1481 */
1482 nd6_grand_start(ifa, ND6_QUEUE_FLAG_NEWGUA);
1483 }
1484
1485 nd6log((LOG_DEBUG,
1486 "%s: DAD complete for %s - no duplicates found\n",
1487 if_name(ifa->ifa_ifp),
1488 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1489 if (dp->dad_ns_lcount > 0)
1490 log(LOG_ERR, "%s: DAD completed while "
1491 "a looped back NS message is detected "
1492 "during DAD for %s.\n",
1493 if_name(ifa->ifa_ifp),
1494 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1495 }
1496 }
1497 err:
1498 nd6_dad_del(dp);
1499 DADQ_WUNLOCK();
1500 done:
1501 NET_EPOCH_EXIT(et);
1502 CURVNET_RESTORE();
1503 }
1504
1505 static void
nd6_dad_duplicated(struct ifaddr * ifa,struct dadq * dp)1506 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1507 {
1508 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1509 struct ifnet *ifp;
1510 char ip6buf[INET6_ADDRSTRLEN];
1511
1512 ifp = ifa->ifa_ifp;
1513
1514 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1515 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1516 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1517 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1518 dp->dad_na_icount);
1519
1520 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1521 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1522
1523 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1524 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1525
1526 /*
1527 * For RFC 7217 stable addresses, increment failure counter here if we still have retries.
1528 * More addresses will be generated as long as retries are not exhausted.
1529 */
1530 if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
1531 u_int dad_failures = atomic_load_int(&DAD_FAILURES(ifp));
1532
1533 if (dad_failures <= V_ip6_stableaddr_maxretries) {
1534 atomic_add_int(&DAD_FAILURES(ifp), 1);
1535 /* if retries exhausted, output an informative error message */
1536 if (dad_failures == V_ip6_stableaddr_maxretries)
1537 log(LOG_ERR, "%s: manual intervention required, consider disabling \"stableaddr\" on the interface"
1538 " or checking hostuuid for uniqueness\n",
1539 if_name(ifp));
1540 }
1541 } else {
1542 log(LOG_ERR, "%s: manual intervention required\n",
1543 if_name(ifp));
1544 }
1545
1546 /*
1547 * If the address is a link-local address formed from an interface
1548 * identifier based on the hardware address which is supposed to be
1549 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1550 * operation on the interface SHOULD be disabled.
1551 * [RFC 4862, Section 5.4.5]
1552 */
1553 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1554 struct in6_addr in6;
1555
1556 /*
1557 * To avoid over-reaction, we only apply this logic when we are
1558 * very sure that hardware addresses are supposed to be unique.
1559 */
1560 switch (ifp->if_type) {
1561 case IFT_ETHER:
1562 case IFT_ATM:
1563 case IFT_IEEE1394:
1564 case IFT_INFINIBAND:
1565 in6 = ia->ia_addr.sin6_addr;
1566 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1567 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1568 ifp->if_inet6->nd_flags |= ND6_IFF_IFDISABLED;
1569 log(LOG_ERR, "%s: possible hardware address "
1570 "duplication detected, disable IPv6\n",
1571 if_name(ifp));
1572 }
1573 break;
1574 }
1575 }
1576 }
1577
1578 /*
1579 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the
1580 * DAD queue unlocked.
1581 */
1582 static void
nd6_dad_ns_output(struct dadq * dp)1583 nd6_dad_ns_output(struct dadq *dp)
1584 {
1585 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1586 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1587 int i;
1588
1589 DADQ_WLOCK_ASSERT();
1590
1591 dp->dad_ns_tcount++;
1592 if ((ifp->if_flags & IFF_UP) == 0) {
1593 DADQ_WUNLOCK();
1594 return;
1595 }
1596 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1597 DADQ_WUNLOCK();
1598 return;
1599 }
1600
1601 dp->dad_ns_ocount++;
1602 if (V_dad_enhanced != 0) {
1603 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1604 dp->dad_nonce[i] = arc4random();
1605 /*
1606 * XXXHRS: Note that in the case that
1607 * DupAddrDetectTransmits > 1, multiple NS messages with
1608 * different nonces can be looped back in an unexpected
1609 * order. The current implementation recognizes only
1610 * the latest nonce on the sender side. Practically it
1611 * should work well in almost all cases.
1612 */
1613 }
1614 DADQ_WUNLOCK();
1615 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1616 (uint8_t *)&dp->dad_nonce[0]);
1617 }
1618
1619 static void
nd6_dad_ns_input(struct ifaddr * ifa,struct nd_opt_nonce * ndopt_nonce)1620 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1621 {
1622 struct dadq *dp;
1623
1624 if (ifa == NULL)
1625 panic("ifa == NULL in nd6_dad_ns_input");
1626
1627 /* Ignore Nonce option when Enhanced DAD is disabled. */
1628 if (V_dad_enhanced == 0)
1629 ndopt_nonce = NULL;
1630 DADQ_RLOCK();
1631 dp = nd6_dad_find(ifa, ndopt_nonce);
1632 if (dp != NULL)
1633 dp->dad_ns_icount++;
1634 DADQ_RUNLOCK();
1635 }
1636
1637 static void
nd6_dad_na_input(struct ifaddr * ifa)1638 nd6_dad_na_input(struct ifaddr *ifa)
1639 {
1640 struct dadq *dp;
1641
1642 if (ifa == NULL)
1643 panic("ifa == NULL in nd6_dad_na_input");
1644
1645 DADQ_RLOCK();
1646 dp = nd6_dad_find(ifa, NULL);
1647 if (dp != NULL)
1648 dp->dad_na_icount++;
1649 DADQ_RUNLOCK();
1650 }
1651
1652 static void
nd6_queue_rel(void * arg)1653 nd6_queue_rel(void *arg)
1654 {
1655 struct nd_queue *ndq = arg;
1656 struct ifaddr *ifa;
1657
1658 ifa = ndq->ndq_ifa;
1659 IF_ADDR_WLOCK_ASSERT(ifa->ifa_ifp);
1660
1661 /* Remove ndq from the nd_queue list and free it */
1662 TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list);
1663 IF_ADDR_WUNLOCK(ifa->ifa_ifp);
1664
1665 free(ndq, M_IP6NDP);
1666 ifa_free(ifa);
1667 }
1668
1669 static void
nd6_queue_timer(void * arg)1670 nd6_queue_timer(void *arg)
1671 {
1672 struct nd_queue *ndq = arg;
1673 struct ifaddr *ifa = ndq->ndq_ifa;
1674 struct ifnet *ifp;
1675 struct in6_addr daddr;
1676 struct epoch_tracker et;
1677 int delay, tlladdr;
1678 u_long flags;
1679
1680 KASSERT(ifa != NULL, ("ND6 queue entry %p with no address", ndq));
1681
1682 ifp = ifa->ifa_ifp;
1683 CURVNET_SET(ifp->if_vnet);
1684 NET_EPOCH_ENTER(et);
1685
1686 daddr = ndq->ndq_daddr;
1687 tlladdr = ND6_NA_OPT_LLA;
1688 flags = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
1689 if ((ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) != 0 && V_ip6_norbit_raif)
1690 flags &= ~ND_NA_FLAG_ROUTER;
1691
1692 /*
1693 * RFC 9131 Section 6.1.2: If the address is preferred,
1694 * then the Override flag SHOULD NOT be set.
1695 */
1696 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_NEWGUA) != 0) {
1697 /*
1698 * XXX: If the address is in the Optimistic state,
1699 * then the Override flag MUST NOT be set.
1700 * We don't support RFC 4429 yet.
1701 */
1702 if ((ifp->if_inet6->nd_flags & ND6_IFF_PREFER_SOURCE) == 0)
1703 flags |= ND_NA_FLAG_OVERRIDE;
1704 }
1705 /*
1706 * RFC 4861 Section 7.2.6: if link-layer address changed,
1707 * The Override flag MAY be set to either zero or one.
1708 */
1709 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_LLADDR) != 0)
1710 flags |= ND_NA_FLAG_OVERRIDE;
1711 /* anycast advertisement delay rule (RFC 4861 7.2.7, SHOULD) */
1712 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_ANYCAST) != 0)
1713 flags |= ND_NA_FLAG_SOLICITED;
1714
1715 /*
1716 * if it was GRAND, wait at least a RetransTimer
1717 * before removing from queue.
1718 */
1719 if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) != 0) {
1720 delay = ifp->if_inet6->nd_retrans * hz / 1000;
1721 callout_reset(&ndq->ndq_callout, delay, nd6_queue_rel, ndq);
1722 IF_ADDR_WUNLOCK(ifp);
1723 } else
1724 nd6_queue_rel(ndq);
1725
1726 if (__predict_true(in6_setscope(&daddr, ifp, NULL) == 0))
1727 nd6_na_output_fib(ifp, &daddr, IFA_IN6(ifa), flags, tlladdr,
1728 NULL, ifp->if_fib);
1729
1730 NET_EPOCH_EXIT(et);
1731 CURVNET_RESTORE();
1732 }
1733
1734 static void
nd6_queue_add(struct ifaddr * ifa,struct in6_addr * daddr,int delay,uint32_t flags)1735 nd6_queue_add(struct ifaddr *ifa, struct in6_addr *daddr,
1736 int delay, uint32_t flags)
1737 {
1738 struct nd_queue *ndq = NULL;
1739 struct ifnet *ifp;
1740 struct in6_ifextra *ext;
1741 char ip6buf[INET6_ADDRSTRLEN];
1742
1743 NET_EPOCH_ASSERT();
1744
1745 ifp = ifa->ifa_ifp;
1746 ext = ifp->if_inet6;
1747 IF_ADDR_WLOCK(ifp);
1748 /*
1749 * if request comes from GRAND, check whether another delayed
1750 * GRAND NA exists in the queue.
1751 * If it exists, cancel previous one and reuse its ndq.
1752 */
1753 if ((flags & ND6_QUEUE_GRAND_MASK) != 0) {
1754 TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) {
1755 if (ndq->ndq_ifa == ifa &&
1756 (flags & ND6_QUEUE_GRAND_MASK) != 0)
1757 break;
1758 }
1759 }
1760 if (ndq == NULL) {
1761 ndq = malloc(sizeof(*ndq), M_IP6NDP, M_NOWAIT | M_ZERO);
1762 if (ndq == NULL) {
1763 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n",
1764 __func__, ip6_sprintf(ip6buf, IFA_IN6(ifa)),
1765 ifp ? if_name(ifp) : "???");
1766 IF_ADDR_WUNLOCK(ifp);
1767 return;
1768 }
1769
1770 callout_init_mtx(&ndq->ndq_callout, &ifp->if_addr_lock,
1771 CALLOUT_TRYLOCK | CALLOUT_RETURNUNLOCKED);
1772 ifa_ref(ifa);
1773 ndq->ndq_ifa = ifa;
1774 TAILQ_INSERT_TAIL(&ext->nd_queue, ndq, ndq_list);
1775 }
1776
1777 memcpy(&ndq->ndq_daddr, daddr, sizeof(struct in6_addr));
1778 ndq->ndq_flags = flags;
1779
1780 nd6log((LOG_DEBUG, "%s: delay IPv6 NA for %s\n", if_name(ifp),
1781 ip6_sprintf(ip6buf, IFA_IN6(ifa))));
1782 callout_reset(&ndq->ndq_callout, delay, nd6_queue_timer, ndq);
1783 IF_ADDR_WUNLOCK(ifp);
1784 }
1785
1786 /*
1787 * Start Gratuitous Neighbor Discovery (GRAND) for specified address.
1788 * Called after DAD completes and by interface link layer change event.
1789 */
1790 void
nd6_grand_start(struct ifaddr * ifa,uint32_t flags)1791 nd6_grand_start(struct ifaddr *ifa, uint32_t flags)
1792 {
1793 struct nd_queue *ndq;
1794 struct in6_ifextra *ext = ifa->ifa_ifp->if_inet6;
1795 struct in6_addr daddr = IN6ADDR_ANY_INIT;
1796 int delay, count = 0;
1797
1798 NET_EPOCH_ASSERT();
1799 /* If we don't need GRAND, don't do it. */
1800 if (V_ip6_grand_count == 0 ||
1801 ifa->ifa_carp != NULL)
1802 return;
1803
1804 /* Check if new address is global */
1805 if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0 &&
1806 in6_addrscope(IFA_IN6(ifa)) != IPV6_ADDR_SCOPE_GLOBAL)
1807 return;
1808
1809 /*
1810 * RFC 9131 Section 6.1.2: These advertisements MUST be
1811 * separated by at least RetransTimer seconds.
1812 */
1813 TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) {
1814 /*
1815 * RFC 9131 Section 6.1.2: a node SHOULD send
1816 * up to MAX_NEIGHBOR_ADVERTISEMENT Neighbor Advertisement messages.
1817 * Make sure we don't queue GRAND more than V_ip6_grand_count
1818 * per interface.
1819 * Since this limitation only applies to GRAND, don't
1820 * count non-GRAND ndq.
1821 */
1822 if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) == 0)
1823 continue;
1824
1825 count++;
1826 if (count >= V_ip6_grand_count)
1827 return;
1828 }
1829
1830 /*
1831 * RFC 9131 Section 6.1.2: if new global address added,
1832 * use the all-routers multicast address.
1833 */
1834 if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0)
1835 daddr = in6addr_linklocal_allrouters;
1836
1837 /*
1838 * RFC 4861 Section 7.2.6: if link-layer address changed,
1839 * use the all-nodes multicast address.
1840 */
1841 if ((flags & ND6_QUEUE_FLAG_LLADDR) != 0)
1842 daddr = in6addr_linklocal_allnodes;
1843
1844 delay = ext->nd_retrans * hz / 1000;
1845 nd6_queue_add(ifa, &daddr, count * delay, flags);
1846 }
1847
1848 /*
1849 * drain nd6 queue. used for address removals.
1850 */
1851 void
nd6_queue_stop(struct ifaddr * ifa)1852 nd6_queue_stop(struct ifaddr *ifa)
1853 {
1854 struct nd_queue *ndq, *dndq;
1855 struct ifnet *ifp;
1856
1857 ifp = ifa->ifa_ifp;
1858 IF_ADDR_WLOCK(ifp);
1859 TAILQ_FOREACH_SAFE(ndq, &ifp->if_inet6->nd_queue, ndq_list, dndq) {
1860 if (ndq->ndq_ifa != ifa)
1861 continue;
1862
1863 callout_stop(&ndq->ndq_callout);
1864
1865 /* Remove ndq from the nd_queue list and free it */
1866 TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list);
1867 free(ndq, M_IP6NDP);
1868 ifa_free(ifa);
1869 }
1870 IF_ADDR_WUNLOCK(ifp);
1871 }
1872