1 /* $OpenBSD: nd6_nbr.c,v 1.153 2024/07/14 18:53:39 bluhm Exp $ */
2 /* $KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 jinmei Exp $ */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/mbuf.h>
37 #include <sys/socket.h>
38 #include <sys/sockio.h>
39 #include <sys/time.h>
40 #include <sys/kernel.h>
41 #include <sys/ioctl.h>
42 #include <sys/syslog.h>
43 #include <sys/queue.h>
44 #include <sys/timeout.h>
45
46 #include <net/if.h>
47 #include <net/if_var.h>
48 #include <net/if_types.h>
49 #include <net/if_dl.h>
50 #include <net/route.h>
51
52 #include <netinet/in.h>
53 #include <netinet/if_ether.h>
54 #include <netinet6/in6_var.h>
55 #include <netinet/ip6.h>
56 #include <netinet6/ip6_var.h>
57 #include <netinet6/nd6.h>
58 #include <netinet/icmp6.h>
59
60 #include "carp.h"
61 #if NCARP > 0
62 #include <netinet/ip_carp.h>
63 #endif
64
65 static TAILQ_HEAD(, dadq) dadq =
66 TAILQ_HEAD_INITIALIZER(dadq); /* list of addresses to run DAD on */
67 struct dadq {
68 TAILQ_ENTRY(dadq) dad_list;
69 struct ifaddr *dad_ifa;
70 int dad_count; /* max NS to send */
71 int dad_ns_tcount; /* # of trials to send NS */
72 int dad_ns_ocount; /* NS sent so far */
73 int dad_ns_icount;
74 int dad_na_icount;
75 struct timeout dad_timer_ch;
76 };
77
78 struct dadq *nd6_dad_find(struct ifaddr *);
79 void nd6_dad_destroy(struct dadq *);
80 void nd6_dad_starttimer(struct dadq *);
81 void nd6_dad_stoptimer(struct dadq *);
82 void nd6_dad_timer(void *);
83 void nd6_dad_ns_output(struct dadq *, struct ifaddr *);
84 void nd6_dad_ns_input(struct ifaddr *);
85 void nd6_dad_duplicated(struct dadq *);
86
87 int nd6_isneighbor(const struct ifnet *, const struct in6_addr *);
88
89 static int dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */
90
91 /*
92 * Input an Neighbor Solicitation Message.
93 *
94 * Based on RFC 2461
95 * Based on RFC 2462 (duplicated address detection)
96 */
97 void
nd6_ns_input(struct mbuf * m,int off,int icmp6len)98 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
99 {
100 struct ifnet *ifp;
101 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
102 struct nd_neighbor_solicit *nd_ns;
103 struct in6_addr saddr6 = ip6->ip6_src;
104 struct in6_addr daddr6 = ip6->ip6_dst;
105 struct in6_addr taddr6;
106 struct in6_addr myaddr6;
107 char *lladdr = NULL;
108 struct ifaddr *ifa = NULL;
109 int lladdrlen = 0;
110 int anycast = 0, proxy = 0, tentative = 0;
111 int i_am_router = (atomic_load_int(&ip6_forwarding) != 0);
112 int tlladdr;
113 struct nd_opts ndopts;
114 struct sockaddr_dl *proxydl = NULL;
115 char addr[INET6_ADDRSTRLEN], addr0[INET6_ADDRSTRLEN];
116
117 ifp = if_get(m->m_pkthdr.ph_ifidx);
118 if (ifp == NULL)
119 goto freeit;
120
121 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
122 if (nd_ns == NULL) {
123 icmp6stat_inc(icp6s_tooshort);
124 if_put(ifp);
125 return;
126 }
127 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
128 taddr6 = nd_ns->nd_ns_target;
129
130 if (ip6->ip6_hlim != 255) {
131 nd6log((LOG_ERR,
132 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
133 ip6->ip6_hlim,
134 inet_ntop(AF_INET6, &ip6->ip6_src, addr, sizeof(addr)),
135 inet_ntop(AF_INET6, &ip6->ip6_dst, addr0, sizeof(addr0)),
136 ifp->if_xname));
137 goto bad;
138 }
139
140 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
141 /* dst has to be solicited node multicast address. */
142 /* don't check ifindex portion */
143 if (daddr6.s6_addr16[0] == __IPV6_ADDR_INT16_MLL &&
144 daddr6.s6_addr32[1] == 0 &&
145 daddr6.s6_addr32[2] == __IPV6_ADDR_INT32_ONE &&
146 daddr6.s6_addr8[12] == 0xff) {
147 ; /*good*/
148 } else {
149 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
150 "(wrong ip6 dst)\n"));
151 goto bad;
152 }
153 } else {
154 /*
155 * Make sure the source address is from a neighbor's address.
156 */
157 if (!nd6_isneighbor(ifp, &saddr6)) {
158 nd6log((LOG_INFO, "nd6_ns_input: "
159 "NS packet from non-neighbor\n"));
160 goto bad;
161 }
162 }
163
164
165 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
166 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
167 goto bad;
168 }
169
170 if (IN6_IS_SCOPE_EMBED(&taddr6))
171 taddr6.s6_addr16[1] = htons(ifp->if_index);
172
173 icmp6len -= sizeof(*nd_ns);
174 if (nd6_options(nd_ns + 1, icmp6len, &ndopts) < 0) {
175 nd6log((LOG_INFO,
176 "nd6_ns_input: invalid ND option, ignored\n"));
177 /* nd6_options have incremented stats */
178 goto freeit;
179 }
180
181 if (ndopts.nd_opts_src_lladdr) {
182 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
183 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
184 }
185
186 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
187 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
188 "(link-layer address option)\n"));
189 goto bad;
190 }
191
192 /*
193 * Attaching target link-layer address to the NA?
194 * (RFC 2461 7.2.4)
195 *
196 * NS IP dst is unicast/anycast MUST NOT add
197 * NS IP dst is solicited-node multicast MUST add
198 *
199 * In implementation, we add target link-layer address by default.
200 * We do not add one in MUST NOT cases.
201 */
202 #if 0 /* too much! */
203 ifa = &in6ifa_ifpwithaddr(ifp, &daddr6)->ia_ifa;
204 if (ifa && (ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST))
205 tlladdr = 0;
206 else
207 #endif
208 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
209 tlladdr = 0;
210 else
211 tlladdr = 1;
212
213 /*
214 * Target address (taddr6) must be either:
215 * (1) Valid unicast/anycast address for my receiving interface,
216 * (2) Unicast address for which I'm offering proxy service, or
217 * (3) "tentative" address on which DAD is being performed.
218 */
219 /* (1) and (3) check. */
220 ifa = &in6ifa_ifpwithaddr(ifp, &taddr6)->ia_ifa;
221 #if NCARP > 0
222 if (ifp->if_type == IFT_CARP && ifa && !carp_iamatch(ifp))
223 ifa = NULL;
224 #endif
225
226 /* (2) check. */
227 if (!ifa) {
228 struct rtentry *rt;
229 struct sockaddr_in6 tsin6;
230
231 bzero(&tsin6, sizeof tsin6);
232 tsin6.sin6_len = sizeof(struct sockaddr_in6);
233 tsin6.sin6_family = AF_INET6;
234 tsin6.sin6_addr = taddr6;
235
236 rt = rtalloc(sin6tosa(&tsin6), 0, m->m_pkthdr.ph_rtableid);
237 if (rt && (rt->rt_flags & RTF_ANNOUNCE) != 0 &&
238 rt->rt_gateway->sa_family == AF_LINK) {
239 /*
240 * proxy NDP for single entry
241 */
242 ifa = &in6ifa_ifpforlinklocal(ifp, IN6_IFF_TENTATIVE|
243 IN6_IFF_DUPLICATED|IN6_IFF_ANYCAST)->ia_ifa;
244 if (ifa) {
245 proxy = 1;
246 proxydl = satosdl(rt->rt_gateway);
247 i_am_router = 0; /* XXX */
248 }
249 }
250 if (rt)
251 rtfree(rt);
252 }
253 if (!ifa) {
254 /*
255 * We've got an NS packet, and we don't have that address
256 * assigned for us. We MUST silently ignore it.
257 * See RFC2461 7.2.3.
258 */
259 goto freeit;
260 }
261 myaddr6 = *IFA_IN6(ifa);
262 anycast = ifatoia6(ifa)->ia6_flags & IN6_IFF_ANYCAST;
263 tentative = ifatoia6(ifa)->ia6_flags & IN6_IFF_TENTATIVE;
264 if (ifatoia6(ifa)->ia6_flags & IN6_IFF_DUPLICATED)
265 goto freeit;
266
267 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
268 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
269 "(if %d, NS packet %d)\n",
270 inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)),
271 ifp->if_addrlen, lladdrlen - 2));
272 goto bad;
273 }
274
275 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
276 log(LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
277 inet_ntop(AF_INET6, &saddr6, addr, sizeof(addr)));
278 goto freeit;
279 }
280
281 /*
282 * We have neighbor solicitation packet, with target address equals to
283 * one of my tentative address.
284 *
285 * src addr how to process?
286 * --- ---
287 * multicast of course, invalid (rejected in ip6_input)
288 * unicast somebody is doing address resolution -> ignore
289 * unspec dup address detection
290 *
291 * The processing is defined in RFC 2462.
292 */
293 if (tentative) {
294 /*
295 * If source address is unspecified address, it is for
296 * duplicated address detection.
297 *
298 * If not, the packet is for address resolution;
299 * silently ignore it.
300 */
301 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
302 nd6_dad_ns_input(ifa);
303
304 goto freeit;
305 }
306
307 /*
308 * If the source address is unspecified address, entries must not
309 * be created or updated.
310 * It looks that sender is performing DAD. Output NA toward
311 * all-node multicast address, to tell the sender that I'm using
312 * the address.
313 * S bit ("solicited") must be zero.
314 */
315 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
316 saddr6 = in6addr_linklocal_allnodes;
317 saddr6.s6_addr16[1] = htons(ifp->if_index);
318 nd6_na_output(ifp, &saddr6, &taddr6,
319 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
320 (i_am_router ? ND_NA_FLAG_ROUTER : 0),
321 tlladdr, sdltosa(proxydl));
322 goto freeit;
323 }
324
325 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen, ND_NEIGHBOR_SOLICIT,
326 0, i_am_router);
327
328 nd6_na_output(ifp, &saddr6, &taddr6,
329 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
330 (i_am_router ? ND_NA_FLAG_ROUTER : 0) | ND_NA_FLAG_SOLICITED,
331 tlladdr, sdltosa(proxydl));
332 freeit:
333 m_freem(m);
334 if_put(ifp);
335 return;
336
337 bad:
338 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
339 inet_ntop(AF_INET6, &saddr6, addr, sizeof(addr))));
340 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
341 inet_ntop(AF_INET6, &daddr6, addr, sizeof(addr))));
342 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
343 inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr))));
344 icmp6stat_inc(icp6s_badns);
345 m_freem(m);
346 if_put(ifp);
347 }
348
349 /*
350 * Output an Neighbor Solicitation Message. Caller specifies:
351 * - ICMP6 header source IP6 address
352 * - ND6 header target IP6 address
353 * - ND6 header source datalink address
354 *
355 * Based on RFC 2461
356 * Based on RFC 2462 (duplicated address detection)
357 *
358 * ln - for source address determination
359 * dad - duplicated address detection
360 */
361 void
nd6_ns_output(struct ifnet * ifp,const struct in6_addr * daddr6,const struct in6_addr * taddr6,const struct in6_addr * saddr6,int dad)362 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
363 const struct in6_addr *taddr6, const struct in6_addr *saddr6, int dad)
364 {
365 struct mbuf *m;
366 struct ip6_hdr *ip6;
367 struct nd_neighbor_solicit *nd_ns;
368 struct sockaddr_in6 src_sa, dst_sa;
369 struct ip6_moptions im6o;
370 int icmp6len;
371 int maxlen;
372 caddr_t mac;
373
374 if (IN6_IS_ADDR_MULTICAST(taddr6))
375 return;
376
377 /* estimate the size of message */
378 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
379 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
380 #ifdef DIAGNOSTIC
381 if (max_linkhdr + maxlen >= MCLBYTES) {
382 printf("%s: max_linkhdr + maxlen >= MCLBYTES (%d + %d > %d)\n",
383 __func__, max_linkhdr, maxlen, MCLBYTES);
384 panic("%s: insufficient MCLBYTES", __func__);
385 /* NOTREACHED */
386 }
387 #endif
388
389 MGETHDR(m, M_DONTWAIT, MT_DATA);
390 if (m && max_linkhdr + maxlen >= MHLEN) {
391 MCLGET(m, M_DONTWAIT);
392 if ((m->m_flags & M_EXT) == 0) {
393 m_free(m);
394 m = NULL;
395 }
396 }
397 if (m == NULL)
398 return;
399 m->m_pkthdr.ph_ifidx = 0;
400 m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
401
402 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
403 m->m_flags |= M_MCAST;
404 im6o.im6o_ifidx = ifp->if_index;
405 im6o.im6o_hlim = 255;
406 im6o.im6o_loop = 0;
407 }
408
409 icmp6len = sizeof(*nd_ns);
410 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
411 m_align(m, maxlen);
412
413 /* fill neighbor solicitation packet */
414 ip6 = mtod(m, struct ip6_hdr *);
415 ip6->ip6_flow = 0;
416 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
417 ip6->ip6_vfc |= IPV6_VERSION;
418 /* ip6->ip6_plen will be set later */
419 ip6->ip6_nxt = IPPROTO_ICMPV6;
420 ip6->ip6_hlim = 255;
421 /* determine the source and destination addresses */
422 bzero(&src_sa, sizeof(src_sa));
423 bzero(&dst_sa, sizeof(dst_sa));
424 src_sa.sin6_family = dst_sa.sin6_family = AF_INET6;
425 src_sa.sin6_len = dst_sa.sin6_len = sizeof(struct sockaddr_in6);
426 if (daddr6 != NULL)
427 dst_sa.sin6_addr = *daddr6;
428 else {
429 dst_sa.sin6_addr.s6_addr16[0] = __IPV6_ADDR_INT16_MLL;
430 dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
431 dst_sa.sin6_addr.s6_addr32[1] = 0;
432 dst_sa.sin6_addr.s6_addr32[2] = __IPV6_ADDR_INT32_ONE;
433 dst_sa.sin6_addr.s6_addr32[3] = taddr6->s6_addr32[3];
434 dst_sa.sin6_addr.s6_addr8[12] = 0xff;
435 }
436 ip6->ip6_dst = dst_sa.sin6_addr;
437 if (!dad) {
438 /*
439 * RFC2461 7.2.2:
440 * "If the source address of the packet prompting the
441 * solicitation is the same as one of the addresses assigned
442 * to the outgoing interface, that address SHOULD be placed
443 * in the IP Source Address of the outgoing solicitation.
444 * Otherwise, any one of the addresses assigned to the
445 * interface should be used."
446 *
447 * We use the source address for the prompting packet
448 * (saddr6), if:
449 * - saddr6 is given from the caller (by giving "ln"), and
450 * - saddr6 belongs to the outgoing interface and
451 * - if taddr is link local saddr6 must be link local as well
452 * Otherwise, we perform the source address selection as usual.
453 */
454 if (saddr6 != NULL)
455 src_sa.sin6_addr = *saddr6;
456
457 if (!IN6_IS_ADDR_LINKLOCAL(taddr6) ||
458 IN6_IS_ADDR_UNSPECIFIED(&src_sa.sin6_addr) ||
459 IN6_IS_ADDR_LINKLOCAL(&src_sa.sin6_addr) ||
460 !in6ifa_ifpwithaddr(ifp, &src_sa.sin6_addr)) {
461 struct rtentry *rt;
462
463 rt = rtalloc(sin6tosa(&dst_sa), RT_RESOLVE,
464 m->m_pkthdr.ph_rtableid);
465 if (!rtisvalid(rt)) {
466 char addr[INET6_ADDRSTRLEN];
467
468 nd6log((LOG_DEBUG,
469 "%s: source can't be determined: dst=%s\n",
470 __func__, inet_ntop(AF_INET6,
471 &dst_sa.sin6_addr, addr, sizeof(addr))));
472 rtfree(rt);
473 goto bad;
474 }
475 src_sa.sin6_addr =
476 ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr;
477 rtfree(rt);
478 }
479 } else {
480 /*
481 * Source address for DAD packet must always be IPv6
482 * unspecified address. (0::0)
483 * We actually don't have to 0-clear the address (we did it
484 * above), but we do so here explicitly to make the intention
485 * clearer.
486 */
487 bzero(&src_sa.sin6_addr, sizeof(src_sa.sin6_addr));
488 }
489 ip6->ip6_src = src_sa.sin6_addr;
490 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
491 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
492 nd_ns->nd_ns_code = 0;
493 nd_ns->nd_ns_reserved = 0;
494 nd_ns->nd_ns_target = *taddr6;
495
496 if (IN6_IS_SCOPE_EMBED(&nd_ns->nd_ns_target))
497 nd_ns->nd_ns_target.s6_addr16[1] = 0;
498
499 /*
500 * Add source link-layer address option.
501 *
502 * spec implementation
503 * --- ---
504 * DAD packet MUST NOT do not add the option
505 * there's no link layer address:
506 * impossible do not add the option
507 * there's link layer address:
508 * Multicast NS MUST add one add the option
509 * Unicast NS SHOULD add one add the option
510 */
511 if (!dad && (mac = nd6_ifptomac(ifp))) {
512 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
513 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
514 /* 8 byte alignments... */
515 optlen = (optlen + 7) & ~7;
516
517 m->m_pkthdr.len += optlen;
518 m->m_len += optlen;
519 icmp6len += optlen;
520 bzero((caddr_t)nd_opt, optlen);
521 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
522 nd_opt->nd_opt_len = optlen >> 3;
523 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
524 }
525
526 ip6->ip6_plen = htons((u_short)icmp6len);
527 nd_ns->nd_ns_cksum = 0;
528 m->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT;
529
530 ip6_output(m, NULL, NULL, dad ? IPV6_UNSPECSRC : 0, &im6o, NULL);
531 icmp6stat_inc(icp6s_outhist + ND_NEIGHBOR_SOLICIT);
532 return;
533
534 bad:
535 m_freem(m);
536 }
537
538 /*
539 * Neighbor advertisement input handling.
540 *
541 * Based on RFC 2461
542 * Based on RFC 2462 (duplicated address detection)
543 *
544 * the following items are not implemented yet:
545 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
546 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
547 */
548 void
nd6_na_input(struct mbuf * m,int off,int icmp6len)549 nd6_na_input(struct mbuf *m, int off, int icmp6len)
550 {
551 struct ifnet *ifp;
552 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
553 struct nd_neighbor_advert *nd_na;
554 struct in6_addr daddr6 = ip6->ip6_dst;
555 struct in6_addr taddr6;
556 int flags;
557 int is_router;
558 int is_solicited;
559 int is_override;
560 char *lladdr = NULL;
561 int lladdrlen = 0;
562 int i_am_router = (atomic_load_int(&ip6_forwarding) != 0);
563 struct ifaddr *ifa;
564 struct in6_ifaddr *ifa6;
565 struct llinfo_nd6 *ln;
566 struct rtentry *rt = NULL;
567 struct sockaddr_dl *sdl;
568 struct nd_opts ndopts;
569 char addr[INET6_ADDRSTRLEN], addr0[INET6_ADDRSTRLEN];
570
571 NET_ASSERT_LOCKED_EXCLUSIVE();
572
573 ifp = if_get(m->m_pkthdr.ph_ifidx);
574 if (ifp == NULL)
575 goto freeit;
576
577 if (ip6->ip6_hlim != 255) {
578 nd6log((LOG_ERR,
579 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
580 ip6->ip6_hlim,
581 inet_ntop(AF_INET6, &ip6->ip6_src, addr, sizeof(addr)),
582 inet_ntop(AF_INET6, &ip6->ip6_dst, addr0, sizeof(addr0)),
583 ifp->if_xname));
584 goto bad;
585 }
586
587 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
588 if (nd_na == NULL) {
589 icmp6stat_inc(icp6s_tooshort);
590 if_put(ifp);
591 return;
592 }
593 taddr6 = nd_na->nd_na_target;
594 flags = nd_na->nd_na_flags_reserved;
595 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
596 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
597 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
598
599 if (IN6_IS_SCOPE_EMBED(&taddr6))
600 taddr6.s6_addr16[1] = htons(ifp->if_index);
601
602 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
603 nd6log((LOG_ERR,
604 "nd6_na_input: invalid target address %s\n",
605 inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr))));
606 goto bad;
607 }
608 if (is_solicited && IN6_IS_ADDR_MULTICAST(&daddr6)) {
609 nd6log((LOG_ERR,
610 "nd6_na_input: a solicited adv is multicasted\n"));
611 goto bad;
612 }
613
614 icmp6len -= sizeof(*nd_na);
615 if (nd6_options(nd_na + 1, icmp6len, &ndopts) < 0) {
616 nd6log((LOG_INFO,
617 "nd6_na_input: invalid ND option, ignored\n"));
618 /* nd6_options have incremented stats */
619 goto freeit;
620 }
621
622 if (IN6_IS_ADDR_MULTICAST(&daddr6) && !ndopts.nd_opts_tgt_lladdr) {
623 nd6log((LOG_INFO,
624 "nd6_na_input: multicast adv without TLLA\n"));
625 goto bad;
626 }
627
628 if (ndopts.nd_opts_tgt_lladdr) {
629 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
630 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
631 }
632
633 ifa6 = in6ifa_ifpwithaddr(ifp, &taddr6);
634 ifa = ifa6 ? &ifa6->ia_ifa : NULL;
635
636 /*
637 * Target address matches one of my interface address.
638 *
639 * If my address is tentative, this means that there's somebody
640 * already using the same address as mine. This indicates DAD failure.
641 * This is defined in RFC 2462.
642 *
643 * Otherwise, process as defined in RFC 2461.
644 */
645 if (ifa && (ifatoia6(ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
646 struct dadq *dp;
647
648 dp = nd6_dad_find(ifa);
649 if (dp) {
650 dp->dad_na_icount++;
651
652 /* remove the address. */
653 nd6_dad_duplicated(dp);
654 }
655 goto freeit;
656 }
657
658 if (ifa) {
659 #if NCARP > 0
660 /*
661 * Ignore NAs silently for carp addresses if we're not
662 * the CARP master.
663 */
664 if (ifp->if_type == IFT_CARP && !carp_iamatch(ifp))
665 goto freeit;
666 #endif
667 log(LOG_ERR,
668 "nd6_na_input: duplicate IP6 address %s\n",
669 inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)));
670 goto freeit;
671 }
672
673 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
674 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
675 "(if %d, NA packet %d)\n",
676 inet_ntop(AF_INET6, &taddr6, addr, sizeof(addr)),
677 ifp->if_addrlen, lladdrlen - 2));
678 goto bad;
679 }
680
681 /* Check if we already have this neighbor in our cache. */
682 rt = nd6_lookup(&taddr6, 0, ifp, ifp->if_rdomain);
683
684 /*
685 * If we are a router, we may create new stale cache entries upon
686 * receiving Unsolicited Neighbor Advertisements.
687 */
688 if (rt == NULL && i_am_router) {
689 rt = nd6_lookup(&taddr6, 1, ifp, ifp->if_rdomain);
690 if (rt == NULL || lladdr == NULL ||
691 ((sdl = satosdl(rt->rt_gateway)) == NULL))
692 goto freeit;
693
694 ln = (struct llinfo_nd6 *)rt->rt_llinfo;
695 sdl->sdl_alen = ifp->if_addrlen;
696 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
697
698 /*
699 * RFC9131 6.1.1
700 *
701 * Routers SHOULD create a new entry for the target address
702 * with the reachability state set to STALE.
703 */
704 ln->ln_state = ND6_LLINFO_STALE;
705 nd6_llinfo_settimer(ln, nd6_gctimer);
706
707 goto freeit;
708 }
709
710 /*
711 * Host:
712 * If no neighbor cache entry is found, NA SHOULD silently be
713 * discarded.
714 */
715 if ((rt == NULL) ||
716 ((ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) ||
717 ((sdl = satosdl(rt->rt_gateway)) == NULL))
718 goto freeit;
719
720 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
721 /*
722 * If the link-layer has address, and no lladdr option came,
723 * discard the packet.
724 */
725 if (ifp->if_addrlen && !lladdr)
726 goto freeit;
727
728 /*
729 * Record link-layer address, and update the state.
730 */
731 sdl->sdl_alen = ifp->if_addrlen;
732 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
733 if (is_solicited) {
734 ln->ln_state = ND6_LLINFO_REACHABLE;
735 ln->ln_byhint = 0;
736 /* Notify userland that a new ND entry is reachable. */
737 rtm_send(rt, RTM_RESOLVE, 0, ifp->if_rdomain);
738 if (!ND6_LLINFO_PERMANENT(ln)) {
739 nd6_llinfo_settimer(ln,
740 ifp->if_nd->reachable);
741 }
742 } else {
743 ln->ln_state = ND6_LLINFO_STALE;
744 nd6_llinfo_settimer(ln, nd6_gctimer);
745 }
746 if ((ln->ln_router = is_router) != 0) {
747 /*
748 * This means a router's state has changed from
749 * non-reachable to probably reachable, and might
750 * affect the status of associated prefixes..
751 */
752 if ((rt->rt_flags & RTF_LLINFO) == 0)
753 goto freeit; /* ln is gone */
754 }
755 } else {
756 int llchange;
757
758 /*
759 * Check if the link-layer address has changed or not.
760 */
761 if (!lladdr)
762 llchange = 0;
763 else {
764 if (sdl->sdl_alen) {
765 if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
766 llchange = 1;
767 else
768 llchange = 0;
769 } else
770 llchange = 1;
771 }
772
773 /*
774 * This is VERY complex. Look at it with care.
775 *
776 * override solicit lladdr llchange action
777 * (L: record lladdr)
778 *
779 * 0 0 n -- (2c)
780 * 0 0 y n (2b) L
781 * 0 0 y y (1) REACHABLE->STALE
782 * 0 1 n -- (2c) *->REACHABLE
783 * 0 1 y n (2b) L *->REACHABLE
784 * 0 1 y y (1) REACHABLE->STALE
785 * 1 0 n -- (2a)
786 * 1 0 y n (2a) L
787 * 1 0 y y (2a) L *->STALE
788 * 1 1 n -- (2a) *->REACHABLE
789 * 1 1 y n (2a) L *->REACHABLE
790 * 1 1 y y (2a) L *->REACHABLE
791 */
792 if (!is_override && (lladdr && llchange)) { /* (1) */
793 /*
794 * If state is REACHABLE, make it STALE.
795 * no other updates should be done.
796 */
797 if (ln->ln_state == ND6_LLINFO_REACHABLE) {
798 ln->ln_state = ND6_LLINFO_STALE;
799 nd6_llinfo_settimer(ln, nd6_gctimer);
800 }
801 goto freeit;
802 } else if (is_override /* (2a) */
803 || (!is_override && (lladdr && !llchange)) /* (2b) */
804 || !lladdr) { /* (2c) */
805 /*
806 * Update link-local address, if any.
807 */
808 if (llchange) {
809 log(LOG_INFO, "ndp info overwritten for %s "
810 "by %s on %s\n",
811 inet_ntop(AF_INET6, &taddr6,
812 addr, sizeof(addr)),
813 ether_sprintf(lladdr), ifp->if_xname);
814 }
815 if (lladdr) {
816 sdl->sdl_alen = ifp->if_addrlen;
817 bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
818 }
819
820 /*
821 * If solicited, make the state REACHABLE.
822 * If not solicited and the link-layer address was
823 * changed, make it STALE.
824 */
825 if (is_solicited) {
826 ln->ln_state = ND6_LLINFO_REACHABLE;
827 ln->ln_byhint = 0;
828 if (!ND6_LLINFO_PERMANENT(ln)) {
829 nd6_llinfo_settimer(ln,
830 ifp->if_nd->reachable);
831 }
832 } else {
833 if (lladdr && llchange) {
834 ln->ln_state = ND6_LLINFO_STALE;
835 nd6_llinfo_settimer(ln, nd6_gctimer);
836 }
837 }
838 }
839
840 if (ln->ln_router && !is_router) {
841 if (!i_am_router) {
842 /*
843 * The neighbor may be used
844 * as a next hop for some destinations
845 * (e.g. redirect case). So we must
846 * call rt6_flush explicitly.
847 */
848 rt6_flush(&ip6->ip6_src, ifp);
849 }
850 }
851 ln->ln_router = is_router;
852 }
853 rt->rt_flags &= ~RTF_REJECT;
854 ln->ln_asked = 0;
855 if_output_mq(ifp, &ln->ln_mq, &ln_hold_total, rt_key(rt), rt);
856
857 freeit:
858 rtfree(rt);
859 m_freem(m);
860 if_put(ifp);
861 return;
862
863 bad:
864 icmp6stat_inc(icp6s_badna);
865 m_freem(m);
866 if_put(ifp);
867 }
868
869 /*
870 * Neighbor advertisement output handling.
871 *
872 * Based on RFC 2461
873 *
874 * the following items are not implemented yet:
875 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
876 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
877 *
878 * tlladdr - 1 if include target link-layer address
879 * sdl0 - sockaddr_dl (= proxy NA) or NULL
880 */
881 void
nd6_na_output(struct ifnet * ifp,const struct in6_addr * daddr6,const struct in6_addr * taddr6,u_long flags,int tlladdr,struct sockaddr * sdl0)882 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6,
883 const struct in6_addr *taddr6, u_long flags, int tlladdr,
884 struct sockaddr *sdl0)
885 {
886 struct mbuf *m;
887 struct rtentry *rt = NULL;
888 struct ip6_hdr *ip6;
889 struct nd_neighbor_advert *nd_na;
890 struct ip6_moptions im6o;
891 struct sockaddr_in6 dst_sa;
892 int icmp6len, maxlen;
893 caddr_t mac = NULL;
894
895 #if NCARP > 0
896 /* Do not send NAs for carp addresses if we're not the CARP master. */
897 if (ifp->if_type == IFT_CARP && !carp_iamatch(ifp))
898 return;
899 #endif
900
901 /* estimate the size of message */
902 maxlen = sizeof(*ip6) + sizeof(*nd_na);
903 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
904 #ifdef DIAGNOSTIC
905 if (max_linkhdr + maxlen >= MCLBYTES) {
906 printf("%s: max_linkhdr + maxlen >= MCLBYTES (%d + %d > %d)\n",
907 __func__, max_linkhdr, maxlen, MCLBYTES);
908 panic("%s: insufficient MCLBYTES", __func__);
909 /* NOTREACHED */
910 }
911 #endif
912
913 MGETHDR(m, M_DONTWAIT, MT_DATA);
914 if (m && max_linkhdr + maxlen >= MHLEN) {
915 MCLGET(m, M_DONTWAIT);
916 if ((m->m_flags & M_EXT) == 0) {
917 m_free(m);
918 m = NULL;
919 }
920 }
921 if (m == NULL)
922 return;
923 m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
924
925 if (IN6_IS_ADDR_MULTICAST(daddr6)) {
926 m->m_flags |= M_MCAST;
927 im6o.im6o_ifidx = ifp->if_index;
928 im6o.im6o_hlim = 255;
929 im6o.im6o_loop = 0;
930 }
931
932 icmp6len = sizeof(*nd_na);
933 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
934 m_align(m, maxlen);
935
936 /* fill neighbor advertisement packet */
937 ip6 = mtod(m, struct ip6_hdr *);
938 ip6->ip6_flow = 0;
939 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
940 ip6->ip6_vfc |= IPV6_VERSION;
941 ip6->ip6_nxt = IPPROTO_ICMPV6;
942 ip6->ip6_hlim = 255;
943 bzero(&dst_sa, sizeof(dst_sa));
944 dst_sa.sin6_len = sizeof(struct sockaddr_in6);
945 dst_sa.sin6_family = AF_INET6;
946 dst_sa.sin6_addr = *daddr6;
947 if (IN6_IS_ADDR_UNSPECIFIED(daddr6)) {
948 /* reply to DAD */
949 dst_sa.sin6_addr.s6_addr16[0] = __IPV6_ADDR_INT16_MLL;
950 dst_sa.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
951 dst_sa.sin6_addr.s6_addr32[1] = 0;
952 dst_sa.sin6_addr.s6_addr32[2] = 0;
953 dst_sa.sin6_addr.s6_addr32[3] = __IPV6_ADDR_INT32_ONE;
954
955 flags &= ~ND_NA_FLAG_SOLICITED;
956 }
957 ip6->ip6_dst = dst_sa.sin6_addr;
958
959 /*
960 * Select a source whose scope is the same as that of the dest.
961 */
962 rt = rtalloc(sin6tosa(&dst_sa), RT_RESOLVE, ifp->if_rdomain);
963 if (!rtisvalid(rt)) {
964 char addr[INET6_ADDRSTRLEN];
965
966 nd6log((LOG_DEBUG, "%s: source can't be determined: dst=%s\n",
967 __func__, inet_ntop(AF_INET6, &dst_sa.sin6_addr, addr,
968 sizeof(addr))));
969 rtfree(rt);
970 goto bad;
971 }
972 ip6->ip6_src = ifatoia6(rt->rt_ifa)->ia_addr.sin6_addr;
973 rtfree(rt);
974 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
975 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
976 nd_na->nd_na_code = 0;
977 nd_na->nd_na_target = *taddr6;
978 if (IN6_IS_SCOPE_EMBED(&nd_na->nd_na_target))
979 nd_na->nd_na_target.s6_addr16[1] = 0;
980
981 /*
982 * "tlladdr" indicates NS's condition for adding tlladdr or not.
983 * see nd6_ns_input() for details.
984 * Basically, if NS packet is sent to unicast/anycast addr,
985 * target lladdr option SHOULD NOT be included.
986 */
987 if (tlladdr) {
988 /*
989 * sdl0 != NULL indicates proxy NA. If we do proxy, use
990 * lladdr in sdl0. If we are not proxying (sending NA for
991 * my address) use lladdr configured for the interface.
992 */
993 if (sdl0 == NULL) {
994 mac = nd6_ifptomac(ifp);
995 } else if (sdl0->sa_family == AF_LINK) {
996 struct sockaddr_dl *sdl;
997 sdl = satosdl(sdl0);
998 if (sdl->sdl_alen == ifp->if_addrlen)
999 mac = LLADDR(sdl);
1000 }
1001 }
1002 if (tlladdr && mac) {
1003 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1004 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1005
1006 /* roundup to 8 bytes alignment! */
1007 optlen = (optlen + 7) & ~7;
1008
1009 m->m_pkthdr.len += optlen;
1010 m->m_len += optlen;
1011 icmp6len += optlen;
1012 bzero((caddr_t)nd_opt, optlen);
1013 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1014 nd_opt->nd_opt_len = optlen >> 3;
1015 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1016 } else
1017 flags &= ~ND_NA_FLAG_OVERRIDE;
1018
1019 ip6->ip6_plen = htons((u_short)icmp6len);
1020 nd_na->nd_na_flags_reserved = flags;
1021 nd_na->nd_na_cksum = 0;
1022 m->m_pkthdr.csum_flags |= M_ICMP_CSUM_OUT;
1023
1024 ip6_output(m, NULL, NULL, 0, &im6o, NULL);
1025 icmp6stat_inc(icp6s_outhist + ND_NEIGHBOR_ADVERT);
1026 return;
1027
1028 bad:
1029 m_freem(m);
1030 }
1031
1032 caddr_t
nd6_ifptomac(struct ifnet * ifp)1033 nd6_ifptomac(struct ifnet *ifp)
1034 {
1035 switch (ifp->if_type) {
1036 case IFT_ETHER:
1037 case IFT_IEEE1394:
1038 case IFT_PROPVIRTUAL:
1039 case IFT_CARP:
1040 case IFT_IEEE80211:
1041 return ((caddr_t)(ifp + 1));
1042 default:
1043 return NULL;
1044 }
1045 }
1046
1047 struct dadq *
nd6_dad_find(struct ifaddr * ifa)1048 nd6_dad_find(struct ifaddr *ifa)
1049 {
1050 struct dadq *dp;
1051
1052 TAILQ_FOREACH(dp, &dadq, dad_list) {
1053 if (dp->dad_ifa == ifa)
1054 return dp;
1055 }
1056 return NULL;
1057 }
1058
1059 void
nd6_dad_destroy(struct dadq * dp)1060 nd6_dad_destroy(struct dadq *dp)
1061 {
1062 TAILQ_REMOVE(&dadq, dp, dad_list);
1063 ifafree(dp->dad_ifa);
1064 free(dp, M_IP6NDP, sizeof(*dp));
1065 ip6_dad_pending--;
1066 }
1067
1068 void
nd6_dad_starttimer(struct dadq * dp)1069 nd6_dad_starttimer(struct dadq *dp)
1070 {
1071 timeout_set_proc(&dp->dad_timer_ch, nd6_dad_timer, dp->dad_ifa);
1072 timeout_add_msec(&dp->dad_timer_ch, RETRANS_TIMER);
1073 }
1074
1075 void
nd6_dad_stoptimer(struct dadq * dp)1076 nd6_dad_stoptimer(struct dadq *dp)
1077 {
1078 timeout_del(&dp->dad_timer_ch);
1079 }
1080
1081 /*
1082 * Start Duplicated Address Detection (DAD) for specified interface address.
1083 */
1084 void
nd6_dad_start(struct ifaddr * ifa)1085 nd6_dad_start(struct ifaddr *ifa)
1086 {
1087 struct in6_ifaddr *ia6 = ifatoia6(ifa);
1088 struct dadq *dp;
1089 char addr[INET6_ADDRSTRLEN];
1090
1091 NET_ASSERT_LOCKED();
1092
1093 /*
1094 * If we don't need DAD, don't do it.
1095 * There are several cases:
1096 * - DAD is disabled (ip6_dad_count == 0)
1097 * - the interface address is anycast
1098 */
1099 KASSERT(ia6->ia6_flags & IN6_IFF_TENTATIVE);
1100 if ((ia6->ia6_flags & IN6_IFF_ANYCAST) || (!ip6_dad_count)) {
1101 ia6->ia6_flags &= ~IN6_IFF_TENTATIVE;
1102
1103 rtm_addr(RTM_CHGADDRATTR, ifa);
1104
1105 return;
1106 }
1107
1108 /* DAD already in progress */
1109 if (nd6_dad_find(ifa) != NULL)
1110 return;
1111
1112 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1113 if (dp == NULL) {
1114 log(LOG_ERR, "%s: memory allocation failed for %s(%s)\n",
1115 __func__, inet_ntop(AF_INET6, &ia6->ia_addr.sin6_addr,
1116 addr, sizeof(addr)),
1117 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???");
1118 return;
1119 }
1120
1121 TAILQ_INSERT_TAIL(&dadq, dp, dad_list);
1122 ip6_dad_pending++;
1123
1124 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", ifa->ifa_ifp->if_xname,
1125 inet_ntop(AF_INET6, &ia6->ia_addr.sin6_addr, addr, sizeof(addr))));
1126
1127 /*
1128 * Send NS packet for DAD, ip6_dad_count times.
1129 * Note that we must delay the first transmission, if this is the
1130 * first packet to be sent from the interface after interface
1131 * (re)initialization.
1132 */
1133 dp->dad_ifa = ifaref(ifa);
1134 dp->dad_count = ip6_dad_count;
1135 dp->dad_ns_icount = dp->dad_na_icount = 0;
1136 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1137 nd6_dad_ns_output(dp, ifa);
1138 nd6_dad_starttimer(dp);
1139 }
1140
1141 /*
1142 * terminate DAD unconditionally. used for address removals.
1143 */
1144 void
nd6_dad_stop(struct ifaddr * ifa)1145 nd6_dad_stop(struct ifaddr *ifa)
1146 {
1147 struct dadq *dp;
1148
1149 dp = nd6_dad_find(ifa);
1150 if (!dp) {
1151 /* DAD wasn't started yet */
1152 return;
1153 }
1154
1155 nd6_dad_stoptimer(dp);
1156 nd6_dad_destroy(dp);
1157 }
1158
1159 void
nd6_dad_timer(void * xifa)1160 nd6_dad_timer(void *xifa)
1161 {
1162 struct ifaddr *ifa;
1163 struct in6_ifaddr *ia6;
1164 struct in6_addr daddr6, taddr6;
1165 struct ifnet *ifp;
1166 struct dadq *dp;
1167 char addr[INET6_ADDRSTRLEN];
1168
1169 NET_LOCK();
1170
1171 /* Sanity check */
1172 if (xifa == NULL) {
1173 log(LOG_ERR, "%s: called with null parameter\n", __func__);
1174 goto done;
1175 }
1176 ifa = xifa;
1177 ia6 = ifatoia6(ifa);
1178 taddr6 = ia6->ia_addr.sin6_addr;
1179 ifp = ifa->ifa_ifp;
1180 dp = nd6_dad_find(ifa);
1181 if (dp == NULL) {
1182 log(LOG_ERR, "%s: DAD structure not found\n", __func__);
1183 goto done;
1184 }
1185 if (ia6->ia6_flags & IN6_IFF_DUPLICATED) {
1186 log(LOG_ERR, "%s: called with duplicated address %s(%s)\n",
1187 __func__, inet_ntop(AF_INET6, &ia6->ia_addr.sin6_addr,
1188 addr, sizeof(addr)),
1189 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???");
1190 goto done;
1191 }
1192 if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1193 log(LOG_ERR, "%s: called with non-tentative address %s(%s)\n",
1194 __func__, inet_ntop(AF_INET6, &ia6->ia_addr.sin6_addr,
1195 addr, sizeof(addr)),
1196 ifa->ifa_ifp ? ifa->ifa_ifp->if_xname : "???");
1197 goto done;
1198 }
1199
1200 /* timeouted with IFF_{RUNNING,UP} check */
1201 if (dp->dad_ns_tcount > dad_maxtry) {
1202 nd6log((LOG_INFO, "%s: could not run DAD, driver problem?\n",
1203 ifa->ifa_ifp->if_xname));
1204
1205 nd6_dad_destroy(dp);
1206 goto done;
1207 }
1208
1209 /* Need more checks? */
1210 if (dp->dad_ns_ocount < dp->dad_count) {
1211 /*
1212 * We have more NS to go. Send NS packet for DAD.
1213 */
1214 nd6_dad_ns_output(dp, ifa);
1215 nd6_dad_starttimer(dp);
1216 } else {
1217 /*
1218 * We have transmitted sufficient number of DAD packets.
1219 */
1220 if (dp->dad_na_icount || dp->dad_ns_icount) {
1221 /* dp will be freed in nd6_dad_duplicated() */
1222 nd6_dad_duplicated(dp);
1223 } else {
1224 /*
1225 * We are done with DAD. No NA came, no NS came.
1226 */
1227 ia6->ia6_flags &= ~IN6_IFF_TENTATIVE;
1228
1229 rtm_addr(RTM_CHGADDRATTR, ifa);
1230
1231 nd6log((LOG_DEBUG,
1232 "%s: DAD complete for %s - no duplicates found\n",
1233 ifa->ifa_ifp->if_xname,
1234 inet_ntop(AF_INET6, &ia6->ia_addr.sin6_addr,
1235 addr, sizeof(addr))));
1236
1237 daddr6 = in6addr_linklocal_allrouters;
1238 daddr6.s6_addr16[1] = htons(ifp->if_index);
1239 /* RFC9131 - inform routers about our new address */
1240 nd6_na_output(ifp, &daddr6, &taddr6, 0, 1, NULL);
1241
1242 nd6_dad_destroy(dp);
1243 }
1244 }
1245
1246 done:
1247 NET_UNLOCK();
1248 }
1249
1250 void
nd6_dad_duplicated(struct dadq * dp)1251 nd6_dad_duplicated(struct dadq *dp)
1252 {
1253 struct in6_ifaddr *ia6 = ifatoia6(dp->dad_ifa);
1254 char addr[INET6_ADDRSTRLEN];
1255
1256 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1257 "NS in/out=%d/%d, NA in=%d\n",
1258 ia6->ia_ifp->if_xname,
1259 inet_ntop(AF_INET6, &ia6->ia_addr.sin6_addr, addr, sizeof(addr)),
1260 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_na_icount);
1261
1262 ia6->ia6_flags &= ~IN6_IFF_TENTATIVE;
1263 ia6->ia6_flags |= IN6_IFF_DUPLICATED;
1264
1265 /* We are done with DAD, with duplicated address found. (failure) */
1266 nd6_dad_stoptimer(dp);
1267
1268 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1269 ia6->ia_ifp->if_xname,
1270 inet_ntop(AF_INET6, &ia6->ia_addr.sin6_addr, addr, sizeof(addr)));
1271 log(LOG_ERR, "%s: manual intervention required\n",
1272 ia6->ia_ifp->if_xname);
1273
1274 rtm_addr(RTM_CHGADDRATTR, dp->dad_ifa);
1275
1276 nd6_dad_destroy(dp);
1277 }
1278
1279 void
nd6_dad_ns_output(struct dadq * dp,struct ifaddr * ifa)1280 nd6_dad_ns_output(struct dadq *dp, struct ifaddr *ifa)
1281 {
1282 struct in6_ifaddr *ia6 = ifatoia6(ifa);
1283 struct ifnet *ifp = ifa->ifa_ifp;
1284
1285 dp->dad_ns_tcount++;
1286 if ((ifp->if_flags & IFF_UP) == 0) {
1287 #if 0
1288 printf("%s: interface down?\n", ifp->if_xname);
1289 #endif
1290 return;
1291 }
1292 if ((ifp->if_flags & IFF_RUNNING) == 0) {
1293 #if 0
1294 printf("%s: interface not running?\n", ifp->if_xname);
1295 #endif
1296 return;
1297 }
1298
1299 dp->dad_ns_ocount++;
1300 nd6_ns_output(ifp, NULL, &ia6->ia_addr.sin6_addr, NULL, 1);
1301 }
1302
1303 void
nd6_dad_ns_input(struct ifaddr * ifa)1304 nd6_dad_ns_input(struct ifaddr *ifa)
1305 {
1306 struct dadq *dp;
1307
1308 if (!ifa)
1309 panic("%s: ifa == NULL", __func__);
1310
1311 dp = nd6_dad_find(ifa);
1312 if (dp == NULL) {
1313 log(LOG_ERR, "%s: DAD structure not found\n", __func__);
1314 return;
1315 }
1316
1317 /*
1318 * if I'm yet to start DAD, someone else started using this address
1319 * first. I have a duplicate and you win.
1320 */
1321 /* XXX more checks for loopback situation - see nd6_dad_timer too */
1322 if (dp->dad_ns_ocount == 0) {
1323 /* dp will be freed in nd6_dad_duplicated() */
1324 nd6_dad_duplicated(dp);
1325 } else {
1326 /*
1327 * not sure if I got a duplicate.
1328 * increment ns count and see what happens.
1329 */
1330 dp->dad_ns_icount++;
1331 }
1332 }
1333
1334 /*
1335 * Check whether ``addr'' is a neighbor address connected to ``ifp''.
1336 */
1337 int
nd6_isneighbor(const struct ifnet * ifp,const struct in6_addr * addr)1338 nd6_isneighbor(const struct ifnet *ifp, const struct in6_addr *addr)
1339 {
1340 struct rtentry *rt;
1341 struct sockaddr_in6 sin6;
1342 unsigned int tableid = ifp->if_rdomain;
1343 int rv = 0;
1344
1345 memset(&sin6, 0, sizeof(sin6));
1346 sin6.sin6_len = sizeof(struct sockaddr_in6);
1347 sin6.sin6_family = AF_INET6;
1348 sin6.sin6_addr = *addr;
1349 rt = rtalloc(sin6tosa(&sin6), 0, tableid);
1350
1351 if (rtisvalid(rt) && ISSET(rt->rt_flags, RTF_CLONING|RTF_CLONED))
1352 rv = if_isconnected(ifp, rt->rt_ifidx);
1353
1354 rtfree(rt);
1355 return (rv);
1356 }
1357