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 *,
102 struct in6_addr *, struct sockaddr_dl *, int, uint32_t);
103
104 static struct ifaddr *nd6_proxy_fill_sdl(struct ifnet *,
105 const struct in6_addr *, struct sockaddr_dl *);
106
107 VNET_DEFINE_STATIC(int, dad_enhanced) = 1;
108 #define V_dad_enhanced VNET(dad_enhanced)
109
110 SYSCTL_DECL(_net_inet6_ip6);
111 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
112 &VNET_NAME(dad_enhanced), 0,
113 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
114
115 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to
116 transmit DAD packet */
117 #define V_dad_maxtry VNET(dad_maxtry)
118
119 VNET_DEFINE_STATIC(int, nd6_onlink_ns_rfc4861) = 0;
120 #define V_nd6_onlink_ns_rfc4861 VNET(nd6_onlink_ns_rfc4861)
121 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_ONLINKNSRFC4861,
122 nd6_onlink_ns_rfc4861, CTLFLAG_VNET | CTLFLAG_RW,
123 &VNET_NAME(nd6_onlink_ns_rfc4861), 0,
124 "Accept 'on-link' ICMPv6 NS messages in compliance with RFC 4861");
125
126 struct nd_queue {
127 TAILQ_ENTRY(nd_queue) ndq_list;
128 struct ifaddr *ndq_ifa;
129 struct in6_addr ndq_daddr;
130 struct in6_addr ndq_taddr;
131 struct sockaddr_dl ndq_sdl;
132 uint32_t ndq_flags;
133 struct callout ndq_callout;
134 };
135
136 /*
137 * Input a Neighbor Solicitation Message.
138 *
139 * Based on RFC 2461
140 * Based on RFC 2462 (duplicate address detection)
141 */
142 void
nd6_ns_input(struct mbuf * m,int off,int icmp6len)143 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
144 {
145 struct ifnet *ifp;
146 struct ip6_hdr *ip6;
147 struct nd_neighbor_solicit *nd_ns;
148 struct in6_addr daddr6, myaddr6, saddr6, taddr6;
149 struct ifaddr *ifa;
150 struct sockaddr_dl proxydl;
151 union nd_opts ndopts;
152 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
153 char *lladdr;
154 int lladdrlen, rflag, tentative, tlladdr;
155 uint32_t dflags;
156
157 ifa = NULL;
158
159 /* RFC 6980: Nodes MUST silently ignore fragments */
160 if(m->m_flags & M_FRAGMENTED)
161 goto freeit;
162
163 ifp = m->m_pkthdr.rcvif;
164 ip6 = mtod(m, struct ip6_hdr *);
165 if (__predict_false(ip6->ip6_hlim != 255)) {
166 ICMP6STAT_INC(icp6s_invlhlim);
167 nd6log((LOG_ERR,
168 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
169 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
170 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
171 goto bads;
172 }
173
174 if (m->m_len < off + icmp6len) {
175 m = m_pullup(m, off + icmp6len);
176 if (m == NULL) {
177 IP6STAT_INC(ip6s_exthdrtoolong);
178 return;
179 }
180 }
181 ip6 = mtod(m, struct ip6_hdr *);
182 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
183
184 saddr6 = ip6->ip6_src;
185 daddr6 = ip6->ip6_dst;
186 taddr6 = nd_ns->nd_ns_target;
187 if (in6_setscope(&taddr6, ifp, NULL) != 0)
188 goto bad;
189
190 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
191 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
192 rflag = 0;
193
194 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
195 /* dst has to be a solicited node multicast address. */
196 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
197 /* don't check ifindex portion */
198 daddr6.s6_addr32[1] == 0 &&
199 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
200 daddr6.s6_addr8[12] == 0xff) {
201 ; /* good */
202 } else {
203 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
204 "(wrong ip6 dst)\n"));
205 goto bad;
206 }
207 } else if (!V_nd6_onlink_ns_rfc4861) {
208 struct sockaddr_in6 src_sa6;
209
210 /*
211 * According to recent IETF discussions, it is not a good idea
212 * to accept a NS from an address which would not be deemed
213 * to be a neighbor otherwise. This point is expected to be
214 * clarified in future revisions of the specification.
215 */
216 bzero(&src_sa6, sizeof(src_sa6));
217 src_sa6.sin6_family = AF_INET6;
218 src_sa6.sin6_len = sizeof(src_sa6);
219 src_sa6.sin6_addr = saddr6;
220 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
221 nd6log((LOG_INFO, "nd6_ns_input: "
222 "NS packet from non-neighbor\n"));
223 goto bad;
224 }
225 }
226
227 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
228 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
229 goto bad;
230 }
231
232 icmp6len -= sizeof(*nd_ns);
233 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
234 if (nd6_options(&ndopts) < 0) {
235 nd6log((LOG_INFO,
236 "nd6_ns_input: invalid ND option, ignored\n"));
237 /* nd6_options have incremented stats */
238 goto freeit;
239 }
240
241 lladdr = NULL;
242 lladdrlen = 0;
243 if (ndopts.nd_opts_src_lladdr) {
244 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
245 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
246 }
247
248 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
249 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
250 "(link-layer address option)\n"));
251 goto bad;
252 }
253
254 /*
255 * Attaching target link-layer address to the NA?
256 * (RFC 2461 7.2.4)
257 *
258 * NS IP dst is unicast/anycast MUST NOT add
259 * NS IP dst is solicited-node multicast MUST add
260 *
261 * In implementation, we add target link-layer address by default.
262 * We do not add one in MUST NOT cases.
263 */
264 tlladdr = 0;
265 if (IN6_IS_ADDR_MULTICAST(&daddr6))
266 tlladdr |= ND6_NA_OPT_LLA;
267
268 /*
269 * Target address (taddr6) must be either:
270 * (1) Valid unicast/anycast address for my receiving interface,
271 * (2) Unicast address for which I'm offering proxy service, or
272 * (3) "tentative" address on which DAD is being performed.
273 */
274 /* (1) and (3) check. */
275 if (ifp->if_carp) {
276 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
277 if (ifa != NULL)
278 tlladdr |= ND6_NA_CARP_MASTER;
279 } else
280 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
281
282 /* (2) check. */
283 dflags = 0;
284 if (ifa == NULL) {
285 if ((ifa = nd6_proxy_fill_sdl(ifp, &taddr6, &proxydl)) != NULL)
286 dflags |= ND6_QUEUE_FLAG_PROXY;
287 }
288 if (ifa == NULL) {
289 /*
290 * We've got an NS packet, and we don't have that address
291 * assigned for us. We MUST silently ignore it.
292 * See RFC2461 7.2.3.
293 */
294 goto freeit;
295 }
296 if ((((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST) != 0)
297 dflags |= ND6_QUEUE_FLAG_ANYCAST;
298 myaddr6 = *IFA_IN6(ifa);
299 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
300 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
301 goto freeit;
302
303 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
304 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
305 "(if %d, NS packet %d)\n",
306 ip6_sprintf(ip6bufs, &taddr6),
307 ifp->if_addrlen, lladdrlen - 2));
308 goto bad;
309 }
310
311 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
312 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
313 ip6_sprintf(ip6bufs, &saddr6)));
314 goto freeit;
315 }
316
317 /*
318 * We have neighbor solicitation packet, with target address equals to
319 * one of my tentative address.
320 *
321 * src addr how to process?
322 * --- ---
323 * multicast of course, invalid (rejected in ip6_input)
324 * unicast somebody is doing address resolution -> ignore
325 * unspec dup address detection
326 *
327 * The processing is defined in RFC 2462.
328 */
329 if (tentative) {
330 /*
331 * If source address is unspecified address, it is for
332 * duplicate address detection.
333 *
334 * If not, the packet is for addess resolution;
335 * silently ignore it.
336 */
337 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
338 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
339
340 goto freeit;
341 }
342
343 /*
344 * If the Target Address is either an anycast address or a unicast
345 * address for which the node is providing proxy service, or the Target
346 * Link-Layer Address option is not included, the Override flag SHOULD
347 * be set to zero. Otherwise, the Override flag SHOULD be set to one.
348 */
349 if (dflags == 0 && (tlladdr & ND6_NA_OPT_LLA) != 0)
350 rflag |= ND_NA_FLAG_OVERRIDE;
351 /*
352 * If the source address is unspecified address, entries must not
353 * be created or updated.
354 * It looks that sender is performing DAD. nd6_na_output() will
355 * send NA toward all-node multicast address, to tell the sender
356 * that I'm using the address.
357 * S bit ("solicited") must be zero.
358 */
359 if (!IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
360 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
361 ND_NEIGHBOR_SOLICIT, 0);
362 rflag |= ND_NA_FLAG_SOLICITED;
363 }
364
365 /*
366 * RFC 4861, anycast or proxy NA sent in response to a NS SHOULD
367 * be delayed by a random time between 0 and MAX_ANYCAST_DELAY_TIME
368 * to reduce the probability of network congestion.
369 */
370 if (dflags == 0)
371 nd6_na_output_fib(ifp, &saddr6, &taddr6, rflag, tlladdr, NULL, M_GETFIB(m));
372 else
373 nd6_queue_add(ifa, &saddr6, &taddr6, &proxydl, arc4random() %
374 (MAX_ANYCAST_DELAY_TIME * hz), dflags);
375 freeit:
376 if (ifa != NULL)
377 ifa_free(ifa);
378 m_freem(m);
379 return;
380
381 bad:
382 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
383 ip6_sprintf(ip6bufs, &saddr6)));
384 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
385 ip6_sprintf(ip6bufs, &daddr6)));
386 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
387 ip6_sprintf(ip6bufs, &taddr6)));
388 bads:
389 ICMP6STAT_INC(icp6s_badns);
390 if (ifa != NULL)
391 ifa_free(ifa);
392 m_freem(m);
393 }
394
395 static struct ifaddr *
nd6_proxy_fill_sdl(struct ifnet * ifp,const struct in6_addr * taddr6,struct sockaddr_dl * sdl)396 nd6_proxy_fill_sdl(struct ifnet *ifp, const struct in6_addr *taddr6,
397 struct sockaddr_dl *sdl)
398 {
399 struct ifaddr *ifa;
400 struct llentry *ln;
401
402 ifa = NULL;
403 ln = nd6_lookup(taddr6, LLE_SF(AF_INET6, 0), ifp);
404 if (ln == NULL)
405 return (ifa);
406 if ((ln->la_flags & (LLE_PUB | LLE_VALID)) == (LLE_PUB | LLE_VALID)) {
407 link_init_sdl(ifp, (struct sockaddr *)sdl, ifp->if_type);
408 sdl->sdl_alen = ifp->if_addrlen;
409 bcopy(ln->ll_addr, &sdl->sdl_data, ifp->if_addrlen);
410 LLE_RUNLOCK(ln);
411 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(ifp,
412 IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
413 } else
414 LLE_RUNLOCK(ln);
415
416 return (ifa);
417 }
418
419 /*
420 * Output a Neighbor Solicitation Message. Caller specifies:
421 * - ICMP6 header source IP6 address
422 * - ND6 header target IP6 address
423 * - ND6 header source datalink address
424 *
425 * Based on RFC 2461
426 * Based on RFC 2462 (duplicate address detection)
427 *
428 * ln - for source address determination
429 * nonce - If non-NULL, NS is used for duplicate address detection and
430 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
431 */
432 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)433 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
434 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
435 uint8_t *nonce, u_int fibnum)
436 {
437 struct mbuf *m;
438 struct m_tag *mtag;
439 struct ip6_hdr *ip6;
440 struct nd_neighbor_solicit *nd_ns;
441 struct ip6_moptions im6o;
442 int icmp6len;
443 int maxlen;
444
445 NET_EPOCH_ASSERT();
446
447 if (IN6_IS_ADDR_MULTICAST(taddr6))
448 return;
449
450 /* estimate the size of message */
451 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
452 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
453 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
454 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
455 __func__, max_linkhdr, maxlen, MCLBYTES));
456
457 if (max_linkhdr + maxlen > MHLEN)
458 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
459 else
460 m = m_gethdr(M_NOWAIT, MT_DATA);
461 if (m == NULL)
462 return;
463 M_SETFIB(m, fibnum);
464
465 icmp6len = sizeof(*nd_ns);
466 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
467 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
468
469 /* fill neighbor solicitation packet */
470 ip6 = mtod(m, struct ip6_hdr *);
471 ip6->ip6_flow = 0;
472 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
473 ip6->ip6_vfc |= IPV6_VERSION;
474 /* ip6->ip6_plen will be set later */
475 ip6->ip6_nxt = IPPROTO_ICMPV6;
476 ip6->ip6_hlim = 255;
477 if (daddr6)
478 ip6->ip6_dst = *daddr6;
479 else {
480 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
481 ip6->ip6_dst.s6_addr16[1] = 0;
482 ip6->ip6_dst.s6_addr32[1] = 0;
483 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
484 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
485 ip6->ip6_dst.s6_addr8[12] = 0xff;
486 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
487 goto bad;
488 }
489 if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) {
490 m->m_flags |= M_MCAST;
491 im6o.im6o_multicast_ifp = ifp;
492 im6o.im6o_multicast_hlim = 255;
493 im6o.im6o_multicast_loop = 0;
494 }
495 if (nonce == NULL) {
496 char ip6buf[INET6_ADDRSTRLEN];
497 struct ifaddr *ifa = NULL;
498
499 /*
500 * RFC2461 7.2.2:
501 * "If the source address of the packet prompting the
502 * solicitation is the same as one of the addresses assigned
503 * to the outgoing interface, that address SHOULD be placed
504 * in the IP Source Address of the outgoing solicitation.
505 * Otherwise, any one of the addresses assigned to the
506 * interface should be used."
507 *
508 * We use the source address for the prompting packet
509 * (saddr6), if saddr6 belongs to the outgoing interface.
510 * Otherwise, we perform the source address selection as usual.
511 */
512 if (saddr6 != NULL)
513 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
514 if (ifa == NULL) {
515 int error;
516
517 error = in6_selectsrc_nbr(fibnum, &ip6->ip6_dst, &im6o,
518 ifp, &ip6->ip6_src);
519 if (error) {
520 nd6log((LOG_DEBUG, "%s: source can't be "
521 "determined: dst=%s, error=%d\n", __func__,
522 ip6_sprintf(ip6buf, &ip6->ip6_dst),
523 error));
524 goto bad;
525 }
526 } else
527 ip6->ip6_src = *saddr6;
528
529 if (ifp->if_carp != NULL) {
530 /*
531 * Check that selected source address belongs to
532 * CARP addresses.
533 */
534 if (ifa == NULL)
535 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp,
536 &ip6->ip6_src);
537 /*
538 * Do not send NS for CARP address if we are not
539 * the CARP master.
540 */
541 if (ifa != NULL && ifa->ifa_carp != NULL &&
542 !(*carp_master_p)(ifa)) {
543 nd6log((LOG_DEBUG,
544 "nd6_ns_output: NS from BACKUP CARP address %s\n",
545 ip6_sprintf(ip6buf, &ip6->ip6_src)));
546 ifa_free(ifa);
547 goto bad;
548 }
549 }
550 if (ifa != NULL)
551 ifa_free(ifa);
552 } else {
553 /*
554 * Source address for DAD packet must always be IPv6
555 * unspecified address. (0::0)
556 * We actually don't have to 0-clear the address (we did it
557 * above), but we do so here explicitly to make the intention
558 * clearer.
559 */
560 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
561 }
562 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
563 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
564 nd_ns->nd_ns_code = 0;
565 nd_ns->nd_ns_reserved = 0;
566 nd_ns->nd_ns_target = *taddr6;
567 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
568
569 /*
570 * Add source link-layer address option.
571 *
572 * spec implementation
573 * --- ---
574 * DAD packet MUST NOT do not add the option
575 * there's no link layer address:
576 * impossible do not add the option
577 * there's link layer address:
578 * Multicast NS MUST add one add the option
579 * Unicast NS SHOULD add one add the option
580 */
581 if (nonce == NULL) {
582 struct nd_opt_hdr *nd_opt;
583 char *mac;
584 int optlen;
585
586 mac = NULL;
587 if (ifp->if_carp)
588 mac = (*carp_macmatch6_p)(ifp, m, &ip6->ip6_src);
589 if (mac == NULL)
590 mac = nd6_ifptomac(ifp);
591
592 if (mac != NULL) {
593 nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
594 optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
595 /* 8 byte alignments... */
596 optlen = (optlen + 7) & ~7;
597 m->m_pkthdr.len += optlen;
598 m->m_len += optlen;
599 icmp6len += optlen;
600 bzero(nd_opt, optlen);
601 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
602 nd_opt->nd_opt_len = optlen >> 3;
603 bcopy(mac, nd_opt + 1, ifp->if_addrlen);
604 }
605 }
606 /*
607 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
608 * This behavior is documented as Enhanced Duplicate Address
609 * Detection in RFC 7527.
610 * net.inet6.ip6.dad_enhanced=0 disables this.
611 */
612 if (V_dad_enhanced != 0 && nonce != NULL) {
613 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
614 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
615 /* 8-byte alignment is required. */
616 optlen = (optlen + 7) & ~7;
617
618 m->m_pkthdr.len += optlen;
619 m->m_len += optlen;
620 icmp6len += optlen;
621 bzero((caddr_t)nd_opt, optlen);
622 nd_opt->nd_opt_type = ND_OPT_NONCE;
623 nd_opt->nd_opt_len = optlen >> 3;
624 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
625 }
626 ip6->ip6_plen = htons((u_short)icmp6len);
627 nd_ns->nd_ns_cksum = 0;
628 nd_ns->nd_ns_cksum =
629 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
630
631 if (send_sendso_input_hook != NULL) {
632 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
633 sizeof(unsigned short), M_NOWAIT);
634 if (mtag == NULL)
635 goto bad;
636 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
637 m_tag_prepend(m, mtag);
638 }
639
640 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
641 &im6o, NULL, NULL);
642 icmp6_ifstat_inc(ifp, ifs6_out_msg);
643 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
644 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_SOLICIT);
645
646 return;
647
648 bad:
649 m_freem(m);
650 }
651
652 #ifndef BURN_BRIDGES
653 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)654 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
655 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
656 {
657
658 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
659 }
660 #endif
661 /*
662 * Neighbor advertisement input handling.
663 *
664 * Based on RFC 2461
665 * Based on RFC 2462 (duplicate address detection)
666 */
667 void
nd6_na_input(struct mbuf * m,int off,int icmp6len)668 nd6_na_input(struct mbuf *m, int off, int icmp6len)
669 {
670 struct ifnet *ifp;
671 struct ip6_hdr *ip6;
672 struct ifaddr *ifa;
673 struct llentry *ln;
674 struct mbuf *chain;
675 struct nd_neighbor_advert *nd_na;
676 struct in6_addr daddr6, taddr6;
677 union nd_opts ndopts;
678 u_char linkhdr[LLE_MAX_LINKHDR];
679 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
680 char *lladdr;
681 size_t linkhdrsize;
682 int flags, is_override, is_router, is_solicited;
683 int lladdr_off, lladdrlen, checklink;
684 bool flush_holdchain = false;
685
686 NET_EPOCH_ASSERT();
687
688 chain = NULL;
689 ln = NULL;
690 checklink = 0;
691
692 /* RFC 6980: Nodes MUST silently ignore fragments */
693 if(m->m_flags & M_FRAGMENTED)
694 goto freeit;
695
696 ifp = m->m_pkthdr.rcvif;
697 ip6 = mtod(m, struct ip6_hdr *);
698 if (__predict_false(ip6->ip6_hlim != 255)) {
699 ICMP6STAT_INC(icp6s_invlhlim);
700 nd6log((LOG_ERR,
701 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
702 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
703 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
704 goto bad;
705 }
706
707 if (m->m_len < off + icmp6len) {
708 m = m_pullup(m, off + icmp6len);
709 if (m == NULL) {
710 IP6STAT_INC(ip6s_exthdrtoolong);
711 return;
712 }
713 }
714 ip6 = mtod(m, struct ip6_hdr *);
715 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
716
717 flags = nd_na->nd_na_flags_reserved;
718 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
719 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
720 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
721
722 taddr6 = nd_na->nd_na_target;
723 if (in6_setscope(&taddr6, ifp, NULL))
724 goto bad; /* XXX: impossible */
725
726 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
727 nd6log((LOG_ERR,
728 "nd6_na_input: invalid target address %s\n",
729 ip6_sprintf(ip6bufs, &taddr6)));
730 goto bad;
731 }
732
733 daddr6 = ip6->ip6_dst;
734 if (IN6_IS_ADDR_MULTICAST(&daddr6))
735 if (is_solicited) {
736 nd6log((LOG_ERR,
737 "nd6_na_input: a solicited adv is multicasted\n"));
738 goto bad;
739 }
740
741 icmp6len -= sizeof(*nd_na);
742 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
743 if (nd6_options(&ndopts) < 0) {
744 nd6log((LOG_INFO,
745 "nd6_na_input: invalid ND option, ignored\n"));
746 /* nd6_options have incremented stats */
747 goto freeit;
748 }
749
750 lladdr = NULL;
751 lladdrlen = 0;
752 if (ndopts.nd_opts_tgt_lladdr) {
753 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
754 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
755 }
756
757 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
758 if (ifa != NULL && ifa->ifa_carp != NULL) {
759 /*
760 * Silently ignore NAs for CARP addresses if we are not
761 * the CARP master.
762 */
763 if (!(*carp_master_p)(ifa)) {
764 nd6log((LOG_DEBUG,
765 "nd6_na_input: NA for BACKUP CARP address %s\n",
766 ip6_sprintf(ip6bufs, &taddr6)));
767 ifa_free(ifa);
768 goto freeit;
769 }
770 }
771 /*
772 * Target address matches one of my interface address.
773 *
774 * If my address is tentative, this means that there's somebody
775 * already using the same address as mine. This indicates DAD failure.
776 * This is defined in RFC 2462.
777 *
778 * Otherwise, process as defined in RFC 2461.
779 */
780 if (ifa
781 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
782 nd6_dad_na_input(ifa);
783 ifa_free(ifa);
784 goto freeit;
785 }
786
787 /* Just for safety, maybe unnecessary. */
788 if (ifa) {
789 ifa_free(ifa);
790 log(LOG_ERR,
791 "nd6_na_input: duplicate IP6 address %s\n",
792 ip6_sprintf(ip6bufs, &taddr6));
793 goto freeit;
794 }
795
796 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
797 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
798 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
799 ifp->if_addrlen, lladdrlen - 2));
800 goto bad;
801 }
802
803 /*
804 * If no neighbor cache entry is found, NA SHOULD silently be
805 * discarded.
806 */
807 ln = nd6_lookup(&taddr6, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
808 if (ln == NULL) {
809 goto freeit;
810 }
811
812 /*
813 * Do not try to override static entry.
814 */
815 if (ln->la_flags & LLE_STATIC)
816 goto freeit;
817
818 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
819 /*
820 * If the link-layer has address, and no lladdr option came,
821 * discard the packet.
822 */
823 if (ifp->if_addrlen && lladdr == NULL) {
824 goto freeit;
825 }
826
827 /*
828 * Record link-layer address, and update the state.
829 */
830 if (!nd6_try_set_entry_addr(ifp, ln, lladdr))
831 goto freeit;
832
833 flush_holdchain = true;
834 if (is_solicited)
835 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
836 else
837 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
838 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
839 if ((ln->ln_router = is_router) != 0) {
840 /*
841 * This means a router's state has changed from
842 * non-reachable to probably reachable, and might
843 * affect the status of associated prefixes..
844 */
845 checklink = 1;
846 }
847 } else {
848 int llchange;
849
850 /*
851 * Check if the link-layer address has changed or not.
852 */
853 if (lladdr == NULL)
854 llchange = 0;
855 else {
856 if (ln->la_flags & LLE_VALID) {
857 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
858 llchange = 1;
859 else
860 llchange = 0;
861 } else
862 llchange = 1;
863 }
864
865 /*
866 * This is VERY complex. Look at it with care.
867 *
868 * override solicit lladdr llchange action
869 * (L: record lladdr)
870 *
871 * 0 0 n -- (2c)
872 * 0 0 y n (2b) L
873 * 0 0 y y (1) REACHABLE->STALE
874 * 0 1 n -- (2c) *->REACHABLE
875 * 0 1 y n (2b) L *->REACHABLE
876 * 0 1 y y (1) REACHABLE->STALE
877 * 1 0 n -- (2a)
878 * 1 0 y n (2a) L
879 * 1 0 y y (2a) L *->STALE
880 * 1 1 n -- (2a) *->REACHABLE
881 * 1 1 y n (2a) L *->REACHABLE
882 * 1 1 y y (2a) L *->REACHABLE
883 */
884 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
885 /*
886 * If state is REACHABLE, make it STALE.
887 * no other updates should be done.
888 */
889 if (ln->ln_state == ND6_LLINFO_REACHABLE)
890 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
891 goto freeit;
892 } else if (is_override /* (2a) */
893 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
894 || lladdr == NULL) { /* (2c) */
895 /*
896 * Update link-local address, if any.
897 */
898 if (lladdr != NULL) {
899 linkhdrsize = sizeof(linkhdr);
900 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
901 linkhdr, &linkhdrsize, &lladdr_off) != 0)
902 goto freeit;
903 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
904 linkhdrsize, lladdr_off) == 0)
905 goto freeit;
906 EVENTHANDLER_INVOKE(lle_event, ln,
907 LLENTRY_RESOLVED);
908 }
909
910 /*
911 * If solicited, make the state REACHABLE.
912 * If not solicited and the link-layer address was
913 * changed, make it STALE.
914 */
915 if (is_solicited)
916 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
917 else {
918 if (lladdr != NULL && llchange)
919 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
920 }
921 }
922
923 if (ln->ln_router && !is_router) {
924 /*
925 * The peer dropped the router flag.
926 * Remove the sender from the Default Router List and
927 * update the Destination Cache entries.
928 */
929 struct ifnet *nd6_ifp;
930
931 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
932 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
933 (nd6_ifp->if_inet6->nd_flags &
934 ND6_IFF_ACCEPT_RTADV) != 0)
935 /*
936 * Even if the neighbor is not in the default
937 * router list, the neighbor may be used as a
938 * next hop for some destinations (e.g. redirect
939 * case). So we must call rt6_flush explicitly.
940 */
941 rt6_flush(&ip6->ip6_src, ifp);
942 }
943 ln->ln_router = is_router;
944 }
945 /* XXX - QL
946 * Does this matter?
947 * rt->rt_flags &= ~RTF_REJECT;
948 */
949 ln->la_asked = 0;
950 if (ln->la_hold != NULL)
951 chain = nd6_grab_holdchain(ln);
952 freeit:
953 if (ln != NULL)
954 LLE_WUNLOCK(ln);
955
956 if (chain != NULL)
957 nd6_flush_holdchain(ifp, ln, chain);
958 if (flush_holdchain)
959 nd6_flush_children_holdchain(ifp, ln);
960
961 if (checklink)
962 pfxlist_onlink_check();
963
964 m_freem(m);
965 return;
966
967 bad:
968 if (ln != NULL)
969 LLE_WUNLOCK(ln);
970
971 ICMP6STAT_INC(icp6s_badna);
972 m_freem(m);
973 }
974
975 /*
976 * Neighbor advertisement output handling.
977 *
978 * Based on RFC 2461
979 *
980 * tlladdr:
981 * - 0x01 if include target link-layer address
982 * - 0x02 if target address is CARP MASTER
983 * sdl0 - sockaddr_dl (= proxy NA) or NULL
984 */
985 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)986 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
987 const struct in6_addr *taddr6, u_long flags, int tlladdr,
988 struct sockaddr *sdl0, u_int fibnum)
989 {
990 struct mbuf *m;
991 struct m_tag *mtag;
992 struct ip6_hdr *ip6;
993 struct nd_neighbor_advert *nd_na;
994 struct ip6_moptions im6o;
995 struct in6_addr daddr6;
996
997 NET_EPOCH_ASSERT();
998
999 int icmp6len, maxlen, error;
1000 caddr_t mac = NULL;
1001
1002 daddr6 = *daddr6_0; /* make a local copy for modification */
1003
1004 /* estimate the size of message */
1005 maxlen = sizeof(*ip6) + sizeof(*nd_na);
1006 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
1007 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
1008 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
1009 __func__, max_linkhdr, maxlen, MCLBYTES));
1010
1011 if (max_linkhdr + maxlen > MHLEN)
1012 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
1013 else
1014 m = m_gethdr(M_NOWAIT, MT_DATA);
1015 if (m == NULL)
1016 return;
1017 M_SETFIB(m, fibnum);
1018
1019 icmp6len = sizeof(*nd_na);
1020 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
1021 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
1022
1023 /* fill neighbor advertisement packet */
1024 ip6 = mtod(m, struct ip6_hdr *);
1025 ip6->ip6_flow = 0;
1026 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
1027 ip6->ip6_vfc |= IPV6_VERSION;
1028 ip6->ip6_nxt = IPPROTO_ICMPV6;
1029 ip6->ip6_hlim = 255;
1030
1031 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
1032 /* reply to DAD */
1033 daddr6 = in6addr_linklocal_allnodes;
1034 if (in6_setscope(&daddr6, ifp, NULL))
1035 goto bad;
1036
1037 flags &= ~ND_NA_FLAG_SOLICITED;
1038 }
1039 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
1040 m->m_flags |= M_MCAST;
1041 im6o.im6o_multicast_ifp = ifp;
1042 im6o.im6o_multicast_hlim = 255;
1043 im6o.im6o_multicast_loop = 0;
1044 }
1045
1046 ip6->ip6_dst = daddr6;
1047 error = in6_selectsrc_nbr(fibnum, &daddr6, &im6o, ifp, &ip6->ip6_src);
1048 if (error) {
1049 char ip6buf[INET6_ADDRSTRLEN];
1050 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1051 "determined: dst=%s, error=%d\n",
1052 ip6_sprintf(ip6buf, &daddr6), error));
1053 goto bad;
1054 }
1055 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1056 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1057 nd_na->nd_na_code = 0;
1058 nd_na->nd_na_target = *taddr6;
1059 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1060
1061 /*
1062 * If we respond from CARP address, we need to prepare mac address
1063 * for carp_output().
1064 */
1065 if (ifp->if_carp && (tlladdr & ND6_NA_CARP_MASTER))
1066 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1067 /*
1068 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1069 * see nd6_ns_input() for details.
1070 * Basically, if NS packet is sent to unicast/anycast addr,
1071 * target lladdr option SHOULD NOT be included.
1072 */
1073 if (tlladdr & ND6_NA_OPT_LLA) {
1074 /*
1075 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1076 * lladdr in sdl0. If we are not proxying (sending NA for
1077 * my address) use lladdr configured for the interface.
1078 */
1079 if (sdl0 == NULL) {
1080 if (mac == NULL)
1081 mac = nd6_ifptomac(ifp);
1082 } else if (sdl0->sa_family == AF_LINK) {
1083 struct sockaddr_dl *sdl;
1084 sdl = (struct sockaddr_dl *)sdl0;
1085 if (sdl->sdl_alen == ifp->if_addrlen)
1086 mac = LLADDR(sdl);
1087 }
1088 }
1089 if ((tlladdr & ND6_NA_OPT_LLA) && mac != NULL) {
1090 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1091 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1092
1093 /* roundup to 8 bytes alignment! */
1094 optlen = (optlen + 7) & ~7;
1095
1096 m->m_pkthdr.len += optlen;
1097 m->m_len += optlen;
1098 icmp6len += optlen;
1099 bzero((caddr_t)nd_opt, optlen);
1100 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1101 nd_opt->nd_opt_len = optlen >> 3;
1102 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1103 } else
1104 flags &= ~ND_NA_FLAG_OVERRIDE;
1105
1106 ip6->ip6_plen = htons((u_short)icmp6len);
1107 nd_na->nd_na_flags_reserved = flags;
1108 nd_na->nd_na_cksum = 0;
1109 nd_na->nd_na_cksum =
1110 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1111
1112 if (send_sendso_input_hook != NULL) {
1113 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1114 sizeof(unsigned short), M_NOWAIT);
1115 if (mtag == NULL)
1116 goto bad;
1117 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1118 m_tag_prepend(m, mtag);
1119 }
1120
1121 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1122 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1123 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1124 ICMP6STAT_INC2(icp6s_outhist, ND_NEIGHBOR_ADVERT);
1125
1126 return;
1127
1128 bad:
1129 m_freem(m);
1130 }
1131
1132 #ifndef BURN_BRIDGES
1133 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)1134 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1135 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1136 struct sockaddr *sdl0)
1137 {
1138
1139 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1140 RT_DEFAULT_FIB);
1141 }
1142 #endif
1143
1144 caddr_t
nd6_ifptomac(struct ifnet * ifp)1145 nd6_ifptomac(struct ifnet *ifp)
1146 {
1147 switch (ifp->if_type) {
1148 case IFT_ETHER:
1149 case IFT_IEEE1394:
1150 case IFT_L2VLAN:
1151 case IFT_INFINIBAND:
1152 case IFT_BRIDGE:
1153 return IF_LLADDR(ifp);
1154 default:
1155 return NULL;
1156 }
1157 }
1158
1159 struct dadq {
1160 TAILQ_ENTRY(dadq) dad_list;
1161 struct ifaddr *dad_ifa;
1162 int dad_count; /* max NS to send */
1163 int dad_ns_tcount; /* # of trials to send NS */
1164 int dad_ns_ocount; /* NS sent so far */
1165 int dad_ns_icount;
1166 int dad_na_icount;
1167 int dad_ns_lcount; /* looped back NS */
1168 int dad_loopbackprobe; /* probing state for loopback detection */
1169 struct callout dad_timer_ch;
1170 struct vnet *dad_vnet;
1171 u_int dad_refcnt;
1172 #define ND_OPT_NONCE_LEN32 \
1173 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1174 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1175 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */
1176 };
1177
1178 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq);
1179 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock);
1180 #define V_dadq VNET(dadq)
1181 #define V_dad_rwlock VNET(dad_rwlock)
1182
1183 #define DADQ_LOCKPTR() (&V_dad_rwlock)
1184 #define DADQ_LOCK_INIT() rw_init(DADQ_LOCKPTR(), "nd6 DAD queue")
1185 #define DADQ_RLOCK() rw_rlock(DADQ_LOCKPTR())
1186 #define DADQ_RUNLOCK() rw_runlock(DADQ_LOCKPTR())
1187 #define DADQ_WLOCK() rw_wlock(DADQ_LOCKPTR())
1188 #define DADQ_WUNLOCK() rw_wunlock(DADQ_LOCKPTR())
1189
1190 #define DADQ_LOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_LOCKED);
1191 #define DADQ_RLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_RLOCKED);
1192 #define DADQ_WLOCK_ASSERT() rw_assert(DADQ_LOCKPTR(), RA_WLOCKED);
1193
1194 static void
nd6_dad_add(struct dadq * dp)1195 nd6_dad_add(struct dadq *dp)
1196 {
1197 DADQ_WLOCK_ASSERT();
1198
1199 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1200 dp->dad_ondadq = true;
1201 }
1202
1203 static void
nd6_dad_del(struct dadq * dp)1204 nd6_dad_del(struct dadq *dp)
1205 {
1206 DADQ_WLOCK_ASSERT();
1207
1208 if (dp->dad_ondadq) {
1209 /*
1210 * Remove dp from the dadq and release the dadq's
1211 * reference.
1212 */
1213 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1214 dp->dad_ondadq = false;
1215 nd6_dad_rele(dp);
1216 }
1217 }
1218
1219 static struct dadq *
nd6_dad_find(struct ifaddr * ifa,struct nd_opt_nonce * n)1220 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
1221 {
1222 struct dadq *dp;
1223
1224 DADQ_LOCK_ASSERT();
1225
1226 TAILQ_FOREACH(dp, &V_dadq, dad_list) {
1227 if (dp->dad_ifa != ifa)
1228 continue;
1229
1230 /*
1231 * Skip if the nonce matches the received one.
1232 * +2 in the length is required because of type and
1233 * length fields are included in a header.
1234 */
1235 if (n != NULL &&
1236 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
1237 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
1238 ND_OPT_NONCE_LEN) == 0) {
1239 dp->dad_ns_lcount++;
1240 continue;
1241 }
1242 break;
1243 }
1244
1245 return (dp);
1246 }
1247
1248 static void
nd6_dad_starttimer(struct dadq * dp,int ticks)1249 nd6_dad_starttimer(struct dadq *dp, int ticks)
1250 {
1251 DADQ_WLOCK_ASSERT();
1252
1253 callout_reset(&dp->dad_timer_ch, ticks, nd6_dad_timer, dp);
1254 }
1255
1256 static void
nd6_dad_stoptimer(struct dadq * dp)1257 nd6_dad_stoptimer(struct dadq *dp)
1258 {
1259 callout_drain(&dp->dad_timer_ch);
1260 }
1261
1262 static void
nd6_dad_rele(struct dadq * dp)1263 nd6_dad_rele(struct dadq *dp)
1264 {
1265 if (refcount_release(&dp->dad_refcnt)) {
1266 KASSERT(!dp->dad_ondadq, ("dp %p still on DAD queue", dp));
1267 ifa_free(dp->dad_ifa);
1268 free(dp, M_IP6NDP);
1269 }
1270 }
1271
1272 void
nd6_dad_init(void)1273 nd6_dad_init(void)
1274 {
1275 DADQ_LOCK_INIT();
1276 TAILQ_INIT(&V_dadq);
1277 }
1278
1279 /*
1280 * Start Duplicate Address Detection (DAD) for specified interface address.
1281 */
1282 void
nd6_dad_start(struct ifaddr * ifa,int delay)1283 nd6_dad_start(struct ifaddr *ifa, int delay)
1284 {
1285 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1286 struct dadq *dp;
1287 char ip6buf[INET6_ADDRSTRLEN];
1288
1289 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0,
1290 ("starting DAD on non-tentative address %p", ifa));
1291
1292 /*
1293 * If we don't need DAD, don't do it.
1294 * There are several cases:
1295 * - DAD is disabled globally or on the interface
1296 * - the interface address is anycast
1297 */
1298 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 ||
1299 V_ip6_dad_count == 0 ||
1300 (ifa->ifa_ifp->if_inet6->nd_flags & ND6_IFF_NO_DAD) != 0) {
1301 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1302 return;
1303 }
1304 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 ||
1305 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1306 (ifa->ifa_ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) != 0)
1307 return;
1308
1309 DADQ_WLOCK();
1310 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1311 /*
1312 * DAD is already in progress. Let the existing entry
1313 * finish it.
1314 */
1315 DADQ_WUNLOCK();
1316 return;
1317 }
1318
1319 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1320 if (dp == NULL) {
1321 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1322 "%s(%s)\n",
1323 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1324 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1325 return;
1326 }
1327 callout_init_rw(&dp->dad_timer_ch, DADQ_LOCKPTR(),
1328 CALLOUT_RETURNUNLOCKED);
1329 #ifdef VIMAGE
1330 dp->dad_vnet = curvnet;
1331 #endif
1332 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1333 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1334
1335 /*
1336 * Send NS packet for DAD, ip6_dad_count times.
1337 * Note that we must delay the first transmission, if this is the
1338 * first packet to be sent from the interface after interface
1339 * (re)initialization.
1340 */
1341 dp->dad_ifa = ifa;
1342 ifa_ref(dp->dad_ifa);
1343 dp->dad_count = V_ip6_dad_count;
1344 dp->dad_ns_icount = dp->dad_na_icount = 0;
1345 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1346 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1347
1348 /* Add this to the dadq and add a reference for the dadq. */
1349 refcount_init(&dp->dad_refcnt, 1);
1350 nd6_dad_add(dp);
1351 nd6_dad_starttimer(dp, delay);
1352 DADQ_WUNLOCK();
1353 }
1354
1355 /*
1356 * terminate DAD unconditionally. used for address removals.
1357 */
1358 void
nd6_dad_stop(struct ifaddr * ifa)1359 nd6_dad_stop(struct ifaddr *ifa)
1360 {
1361 struct dadq *dp;
1362
1363 DADQ_WLOCK();
1364 dp = nd6_dad_find(ifa, NULL);
1365 if (dp == NULL) {
1366 DADQ_WUNLOCK();
1367 /* DAD wasn't started yet */
1368 return;
1369 }
1370
1371 /*
1372 * Acquire a temporary reference so that we can safely stop the callout.
1373 */
1374 (void)refcount_acquire(&dp->dad_refcnt);
1375 nd6_dad_del(dp);
1376 DADQ_WUNLOCK();
1377
1378 nd6_dad_stoptimer(dp);
1379 nd6_dad_rele(dp);
1380 }
1381
1382 static void
nd6_dad_timer(void * arg)1383 nd6_dad_timer(void *arg)
1384 {
1385 struct dadq *dp = arg;
1386 struct ifaddr *ifa = dp->dad_ifa;
1387 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1388 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1389 char ip6buf[INET6_ADDRSTRLEN];
1390 struct epoch_tracker et;
1391
1392 CURVNET_SET(dp->dad_vnet);
1393 KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
1394
1395 NET_EPOCH_ENTER(et);
1396 if (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) {
1397 /* Do not need DAD for ifdisabled interface. */
1398 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1399 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1400 goto err;
1401 }
1402 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1403 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1404 "%s(%s)\n",
1405 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1406 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1407 goto err;
1408 }
1409 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1410 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1411 "%s(%s)\n",
1412 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1413 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1414 goto err;
1415 }
1416
1417 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1418 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1419 (((ifp->if_flags & IFF_UP) == 0) ||
1420 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1421 nd6log((LOG_INFO, "%s: could not run DAD "
1422 "because the interface was down or not running.\n",
1423 if_name(ifa->ifa_ifp)));
1424 goto err;
1425 }
1426
1427 /* Need more checks? */
1428 if (dp->dad_ns_ocount < dp->dad_count) {
1429 /*
1430 * We have more NS to go. Send NS packet for DAD.
1431 */
1432 nd6_dad_starttimer(dp,
1433 (long)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000);
1434 nd6_dad_ns_output(dp);
1435 goto done;
1436 } else {
1437 /*
1438 * We have transmitted sufficient number of DAD packets.
1439 * See what we've got.
1440 */
1441 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0) {
1442 /* We've seen NS or NA, means DAD has failed. */
1443 nd6_dad_duplicated(ifa, dp);
1444 } else if (V_dad_enhanced != 0 &&
1445 dp->dad_ns_lcount > 0 &&
1446 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1447 /*
1448 * Sec. 4.1 in RFC 7527 requires transmission of
1449 * additional probes until the loopback condition
1450 * becomes clear when a looped back probe is detected.
1451 */
1452 log(LOG_ERR, "%s: a looped back NS message is "
1453 "detected during DAD for %s. "
1454 "Another DAD probes are being sent.\n",
1455 if_name(ifa->ifa_ifp),
1456 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1457 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1458 /*
1459 * Send an NS immediately and increase dad_count by
1460 * V_nd6_mmaxtries - 1.
1461 */
1462 dp->dad_count =
1463 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1464 nd6_dad_starttimer(dp,
1465 (long)ifa->ifa_ifp->if_inet6->nd_retrans * hz / 1000);
1466 nd6_dad_ns_output(dp);
1467 goto done;
1468 } else {
1469 /*
1470 * We are done with DAD. No NA came, no NS came.
1471 * No duplicate address found. Check IFDISABLED flag
1472 * again in case that it is changed between the
1473 * beginning of this function and here.
1474 *
1475 * Reset DAD failures counter if using stable addresses.
1476 */
1477 if ((ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED) == 0) {
1478 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1479 if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY))
1480 atomic_store_int(&DAD_FAILURES(ifp), 0);
1481 /*
1482 * RFC 9131 Section 6.1.2: The first advertisement
1483 * SHOULD be sent as soon as an address changes the
1484 * state from tentative to preferred.
1485 */
1486 nd6_grand_start(ifa, ND6_QUEUE_FLAG_NEWGUA);
1487 }
1488
1489 nd6log((LOG_DEBUG,
1490 "%s: DAD complete for %s - no duplicates found\n",
1491 if_name(ifa->ifa_ifp),
1492 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1493 if (dp->dad_ns_lcount > 0)
1494 log(LOG_ERR, "%s: DAD completed while "
1495 "a looped back NS message is detected "
1496 "during DAD for %s.\n",
1497 if_name(ifa->ifa_ifp),
1498 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1499 }
1500 }
1501 err:
1502 nd6_dad_del(dp);
1503 DADQ_WUNLOCK();
1504 done:
1505 NET_EPOCH_EXIT(et);
1506 CURVNET_RESTORE();
1507 }
1508
1509 static void
nd6_dad_duplicated(struct ifaddr * ifa,struct dadq * dp)1510 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1511 {
1512 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1513 struct ifnet *ifp;
1514 char ip6buf[INET6_ADDRSTRLEN];
1515
1516 ifp = ifa->ifa_ifp;
1517
1518 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1519 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1520 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1521 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1522 dp->dad_na_icount);
1523
1524 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1525 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1526
1527 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1528 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1529
1530 /*
1531 * For RFC 7217 stable addresses, increment failure counter here if we still have retries.
1532 * More addresses will be generated as long as retries are not exhausted.
1533 */
1534 if ((ifp->if_inet6->nd_flags & ND6_IFF_STABLEADDR) && !(ia->ia6_flags & IN6_IFF_TEMPORARY)) {
1535 u_int dad_failures = atomic_load_int(&DAD_FAILURES(ifp));
1536
1537 if (dad_failures <= V_ip6_stableaddr_maxretries) {
1538 atomic_add_int(&DAD_FAILURES(ifp), 1);
1539 /* if retries exhausted, output an informative error message */
1540 if (dad_failures == V_ip6_stableaddr_maxretries)
1541 log(LOG_ERR, "%s: manual intervention required, consider disabling \"stableaddr\" on the interface"
1542 " or checking hostuuid for uniqueness\n",
1543 if_name(ifp));
1544 }
1545 } else {
1546 log(LOG_ERR, "%s: manual intervention required\n",
1547 if_name(ifp));
1548 }
1549
1550 /*
1551 * If the address is a link-local address formed from an interface
1552 * identifier based on the hardware address which is supposed to be
1553 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1554 * operation on the interface SHOULD be disabled.
1555 * [RFC 4862, Section 5.4.5]
1556 */
1557 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1558 struct in6_addr in6;
1559
1560 /*
1561 * To avoid over-reaction, we only apply this logic when we are
1562 * very sure that hardware addresses are supposed to be unique.
1563 */
1564 switch (ifp->if_type) {
1565 case IFT_ETHER:
1566 case IFT_ATM:
1567 case IFT_IEEE1394:
1568 case IFT_INFINIBAND:
1569 in6 = ia->ia_addr.sin6_addr;
1570 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1571 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1572 ifp->if_inet6->nd_flags |= ND6_IFF_IFDISABLED;
1573 log(LOG_ERR, "%s: possible hardware address "
1574 "duplication detected, disable IPv6\n",
1575 if_name(ifp));
1576 }
1577 break;
1578 }
1579 }
1580 }
1581
1582 /*
1583 * Transmit a neighbour solicitation for the purpose of DAD. Returns with the
1584 * DAD queue unlocked.
1585 */
1586 static void
nd6_dad_ns_output(struct dadq * dp)1587 nd6_dad_ns_output(struct dadq *dp)
1588 {
1589 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1590 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1591 int i;
1592
1593 DADQ_WLOCK_ASSERT();
1594
1595 dp->dad_ns_tcount++;
1596 if ((ifp->if_flags & IFF_UP) == 0) {
1597 DADQ_WUNLOCK();
1598 return;
1599 }
1600 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1601 DADQ_WUNLOCK();
1602 return;
1603 }
1604
1605 dp->dad_ns_ocount++;
1606 if (V_dad_enhanced != 0) {
1607 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1608 dp->dad_nonce[i] = arc4random();
1609 /*
1610 * XXXHRS: Note that in the case that
1611 * DupAddrDetectTransmits > 1, multiple NS messages with
1612 * different nonces can be looped back in an unexpected
1613 * order. The current implementation recognizes only
1614 * the latest nonce on the sender side. Practically it
1615 * should work well in almost all cases.
1616 */
1617 }
1618 DADQ_WUNLOCK();
1619 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1620 (uint8_t *)&dp->dad_nonce[0]);
1621 }
1622
1623 static void
nd6_dad_ns_input(struct ifaddr * ifa,struct nd_opt_nonce * ndopt_nonce)1624 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1625 {
1626 struct dadq *dp;
1627
1628 if (ifa == NULL)
1629 panic("ifa == NULL in nd6_dad_ns_input");
1630
1631 /* Ignore Nonce option when Enhanced DAD is disabled. */
1632 if (V_dad_enhanced == 0)
1633 ndopt_nonce = NULL;
1634 DADQ_RLOCK();
1635 dp = nd6_dad_find(ifa, ndopt_nonce);
1636 if (dp != NULL)
1637 dp->dad_ns_icount++;
1638 DADQ_RUNLOCK();
1639 }
1640
1641 static void
nd6_dad_na_input(struct ifaddr * ifa)1642 nd6_dad_na_input(struct ifaddr *ifa)
1643 {
1644 struct dadq *dp;
1645
1646 if (ifa == NULL)
1647 panic("ifa == NULL in nd6_dad_na_input");
1648
1649 DADQ_RLOCK();
1650 dp = nd6_dad_find(ifa, NULL);
1651 if (dp != NULL)
1652 dp->dad_na_icount++;
1653 DADQ_RUNLOCK();
1654 }
1655
1656 static void
nd6_queue_rel(void * arg)1657 nd6_queue_rel(void *arg)
1658 {
1659 struct nd_queue *ndq = arg;
1660 struct ifaddr *ifa;
1661
1662 ifa = ndq->ndq_ifa;
1663 IF_ADDR_WLOCK_ASSERT(ifa->ifa_ifp);
1664
1665 /* Remove ndq from the nd_queue list and free it */
1666 TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list);
1667 IF_ADDR_WUNLOCK(ifa->ifa_ifp);
1668
1669 free(ndq, M_IP6NDP);
1670 ifa_free(ifa);
1671 }
1672
1673 static void
nd6_queue_timer(void * arg)1674 nd6_queue_timer(void *arg)
1675 {
1676 struct nd_queue *ndq = arg;
1677 struct ifaddr *ifa = ndq->ndq_ifa;
1678 struct ifnet *ifp;
1679 struct in6_addr daddr, taddr;
1680 struct sockaddr_dl sdl;
1681 struct epoch_tracker et;
1682 int delay, tlladdr;
1683 u_long flags;
1684 bool proxy;
1685
1686 KASSERT(ifa != NULL, ("ND6 queue entry %p with no address", ndq));
1687
1688 ifp = ifa->ifa_ifp;
1689 CURVNET_SET(ifp->if_vnet);
1690 NET_EPOCH_ENTER(et);
1691
1692 daddr = ndq->ndq_daddr;
1693 taddr = ndq->ndq_taddr;
1694 tlladdr = ND6_NA_OPT_LLA;
1695 flags = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
1696 if ((ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) != 0 && V_ip6_norbit_raif)
1697 flags &= ~ND_NA_FLAG_ROUTER;
1698
1699 /*
1700 * RFC 9131 Section 6.1.2: If the address is preferred,
1701 * then the Override flag SHOULD NOT be set.
1702 */
1703 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_NEWGUA) != 0) {
1704 /*
1705 * XXX: If the address is in the Optimistic state,
1706 * then the Override flag MUST NOT be set.
1707 * We don't support RFC 4429 yet.
1708 */
1709 if ((ifp->if_inet6->nd_flags & ND6_IFF_PREFER_SOURCE) == 0)
1710 flags |= ND_NA_FLAG_OVERRIDE;
1711 }
1712 /*
1713 * RFC 4861 Section 7.2.6: if link-layer address changed,
1714 * The Override flag MAY be set to either zero or one.
1715 */
1716 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_LLADDR) != 0)
1717 flags |= ND_NA_FLAG_OVERRIDE;
1718 /* anycast advertisement delay rule (RFC 4861 7.2.7, SHOULD) */
1719 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_ANYCAST) != 0)
1720 flags |= ND_NA_FLAG_SOLICITED;
1721 /* proxy advertisement delay rule (RFC 4861 7.2.8, SHOULD) */
1722 proxy = false;
1723 if ((ndq->ndq_flags & ND6_QUEUE_FLAG_PROXY) != 0) {
1724 flags |= ND_NA_FLAG_SOLICITED;
1725 sdl = ndq->ndq_sdl;
1726 proxy = true;
1727 }
1728
1729 /*
1730 * if it was GRAND, wait at least a RetransTimer
1731 * before removing from queue.
1732 */
1733 if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) != 0) {
1734 delay = ifp->if_inet6->nd_retrans * hz / 1000;
1735 callout_reset(&ndq->ndq_callout, delay, nd6_queue_rel, ndq);
1736 IF_ADDR_WUNLOCK(ifp);
1737 } else
1738 nd6_queue_rel(ndq);
1739
1740 if (__predict_true(in6_setscope(&daddr, ifp, NULL) == 0))
1741 nd6_na_output_fib(ifp, &daddr, &taddr, flags, tlladdr,
1742 proxy ? (struct sockaddr *)&sdl : NULL, ifp->if_fib);
1743
1744 NET_EPOCH_EXIT(et);
1745 CURVNET_RESTORE();
1746 }
1747
1748 /*
1749 * Queue a delayed IPv6 Neighbor Advertisement.
1750 *
1751 * daddr: destination address (who the NA is sent to)
1752 * taddr: target address being advertised (used for proxy NAs)
1753 * sdl: link-layer address (used for proxy NAs)
1754 */
1755 static void
nd6_queue_add(struct ifaddr * ifa,struct in6_addr * daddr,struct in6_addr * taddr,struct sockaddr_dl * sdl,int delay,uint32_t flags)1756 nd6_queue_add(struct ifaddr *ifa, struct in6_addr *daddr,
1757 struct in6_addr *taddr, struct sockaddr_dl *sdl, int delay, uint32_t flags)
1758 {
1759 struct nd_queue *ndq = NULL;
1760 struct ifnet *ifp;
1761 struct in6_ifextra *ext;
1762 char ip6buf[INET6_ADDRSTRLEN];
1763
1764 NET_EPOCH_ASSERT();
1765
1766 ifp = ifa->ifa_ifp;
1767 ext = ifp->if_inet6;
1768 IF_ADDR_WLOCK(ifp);
1769 /*
1770 * if request comes from GRAND, check whether another delayed
1771 * GRAND NA exists in the queue.
1772 * If it exists, cancel previous one and reuse its ndq.
1773 */
1774 if ((flags & ND6_QUEUE_GRAND_MASK) != 0) {
1775 TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) {
1776 if (ndq->ndq_ifa == ifa &&
1777 (flags & ND6_QUEUE_GRAND_MASK) != 0)
1778 break;
1779 }
1780 }
1781 if (ndq == NULL) {
1782 ndq = malloc(sizeof(*ndq), M_IP6NDP, M_NOWAIT | M_ZERO);
1783 if (ndq == NULL) {
1784 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n",
1785 __func__, ip6_sprintf(ip6buf, IFA_IN6(ifa)),
1786 ifp ? if_name(ifp) : "???");
1787 IF_ADDR_WUNLOCK(ifp);
1788 return;
1789 }
1790
1791 callout_init_mtx(&ndq->ndq_callout, &ifp->if_addr_lock,
1792 CALLOUT_TRYLOCK | CALLOUT_RETURNUNLOCKED);
1793 ifa_ref(ifa);
1794 ndq->ndq_ifa = ifa;
1795 TAILQ_INSERT_TAIL(&ext->nd_queue, ndq, ndq_list);
1796 }
1797
1798 memcpy(&ndq->ndq_daddr, daddr, sizeof(struct in6_addr));
1799 /*
1800 * For proxy NAs, the target address (taddr) being advertised differs from
1801 * the interface address (ifa), so we must explicitly store both the proxy
1802 * target address and its link-layer address (sdl).
1803 * For non-proxy NAs, use the interface address (ifa) itself as the target.
1804 */
1805 if ((flags & ND6_QUEUE_FLAG_PROXY) != 0) {
1806 memcpy(&ndq->ndq_taddr, taddr, sizeof(struct in6_addr));
1807 memcpy(&ndq->ndq_sdl, sdl, sizeof(struct sockaddr_dl));
1808 } else
1809 memcpy(&ndq->ndq_taddr, IFA_IN6(ifa), sizeof(struct in6_addr));
1810 ndq->ndq_flags = flags;
1811
1812 nd6log((LOG_DEBUG, "%s: delay IPv6 NA for %s\n", if_name(ifp),
1813 ip6_sprintf(ip6buf, IFA_IN6(ifa))));
1814 callout_reset(&ndq->ndq_callout, delay, nd6_queue_timer, ndq);
1815 IF_ADDR_WUNLOCK(ifp);
1816 }
1817
1818 /*
1819 * Start Gratuitous Neighbor Discovery (GRAND) for specified address.
1820 * Called after DAD completes and by interface link layer change event.
1821 */
1822 void
nd6_grand_start(struct ifaddr * ifa,uint32_t flags)1823 nd6_grand_start(struct ifaddr *ifa, uint32_t flags)
1824 {
1825 struct nd_queue *ndq;
1826 struct in6_ifextra *ext = ifa->ifa_ifp->if_inet6;
1827 struct in6_addr daddr = IN6ADDR_ANY_INIT;
1828 int delay, count = 0;
1829
1830 NET_EPOCH_ASSERT();
1831 /* If we don't need GRAND, don't do it. */
1832 if (V_ip6_grand_count == 0 ||
1833 ifa->ifa_carp != NULL)
1834 return;
1835
1836 /* Check if new address is global */
1837 if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0 &&
1838 in6_addrscope(IFA_IN6(ifa)) != IPV6_ADDR_SCOPE_GLOBAL)
1839 return;
1840
1841 /*
1842 * RFC 9131 Section 6.1.2: These advertisements MUST be
1843 * separated by at least RetransTimer seconds.
1844 */
1845 TAILQ_FOREACH(ndq, &ext->nd_queue, ndq_list) {
1846 /*
1847 * RFC 9131 Section 6.1.2: a node SHOULD send
1848 * up to MAX_NEIGHBOR_ADVERTISEMENT Neighbor Advertisement messages.
1849 * Make sure we don't queue GRAND more than V_ip6_grand_count
1850 * per interface.
1851 * Since this limitation only applies to GRAND, don't
1852 * count non-GRAND ndq.
1853 */
1854 if ((ndq->ndq_flags & ND6_QUEUE_GRAND_MASK) == 0)
1855 continue;
1856
1857 count++;
1858 if (count >= V_ip6_grand_count)
1859 return;
1860 }
1861
1862 /*
1863 * RFC 9131 Section 6.1.2: if new global address added,
1864 * use the all-routers multicast address.
1865 */
1866 if ((flags & ND6_QUEUE_FLAG_NEWGUA) != 0)
1867 daddr = in6addr_linklocal_allrouters;
1868
1869 /*
1870 * RFC 4861 Section 7.2.6: if link-layer address changed,
1871 * use the all-nodes multicast address.
1872 */
1873 if ((flags & ND6_QUEUE_FLAG_LLADDR) != 0)
1874 daddr = in6addr_linklocal_allnodes;
1875
1876 delay = ext->nd_retrans * hz / 1000;
1877 nd6_queue_add(ifa, &daddr, NULL, NULL, count * delay, flags);
1878 }
1879
1880 /*
1881 * drain nd6 queue. used for address removals.
1882 */
1883 void
nd6_queue_stop(struct ifaddr * ifa)1884 nd6_queue_stop(struct ifaddr *ifa)
1885 {
1886 struct nd_queue *ndq, *dndq;
1887 struct ifnet *ifp;
1888
1889 ifp = ifa->ifa_ifp;
1890 IF_ADDR_WLOCK(ifp);
1891 TAILQ_FOREACH_SAFE(ndq, &ifp->if_inet6->nd_queue, ndq_list, dndq) {
1892 if (ndq->ndq_ifa != ifa)
1893 continue;
1894
1895 callout_stop(&ndq->ndq_callout);
1896
1897 /* Remove ndq from the nd_queue list and free it */
1898 TAILQ_REMOVE(&ifa->ifa_ifp->if_inet6->nd_queue, ndq, ndq_list);
1899 free(ndq, M_IP6NDP);
1900 ifa_free(ifa);
1901 }
1902 IF_ADDR_WUNLOCK(ifp);
1903 }
1904