1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 #include "opt_ipsec.h"
38 #include "opt_mpath.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/libkern.h>
44 #include <sys/lock.h>
45 #include <sys/rwlock.h>
46 #include <sys/mbuf.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/errno.h>
52 #include <sys/sysctl.h>
53 #include <sys/syslog.h>
54 #include <sys/queue.h>
55 #include <sys/callout.h>
56 #include <sys/refcount.h>
57
58 #include <net/if.h>
59 #include <net/if_types.h>
60 #include <net/if_dl.h>
61 #include <net/if_var.h>
62 #include <net/route.h>
63 #ifdef RADIX_MPATH
64 #include <net/radix_mpath.h>
65 #endif
66 #include <net/vnet.h>
67
68 #include <netinet/in.h>
69 #include <netinet/in_var.h>
70 #include <net/if_llatbl.h>
71 #include <netinet6/in6_var.h>
72 #include <netinet6/in6_ifattach.h>
73 #include <netinet/ip6.h>
74 #include <netinet6/ip6_var.h>
75 #include <netinet6/scope6_var.h>
76 #include <netinet6/nd6.h>
77 #include <netinet/icmp6.h>
78 #include <netinet/ip_carp.h>
79 #include <netinet6/send.h>
80
81 #define SDL(s) ((struct sockaddr_dl *)s)
82
83 struct dadq;
84 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *);
85 static void nd6_dad_add(struct dadq *dp);
86 static void nd6_dad_del(struct dadq *dp);
87 static void nd6_dad_rele(struct dadq *);
88 static void nd6_dad_starttimer(struct dadq *, int, int);
89 static void nd6_dad_stoptimer(struct dadq *);
90 static void nd6_dad_timer(struct dadq *);
91 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *);
92 static void nd6_dad_ns_output(struct dadq *);
93 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *);
94 static void nd6_dad_na_input(struct ifaddr *);
95 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
96 const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
97 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *,
98 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int);
99
100 static VNET_DEFINE(int, dad_enhanced) = 1;
101 #define V_dad_enhanced VNET(dad_enhanced)
102
103 SYSCTL_DECL(_net_inet6_ip6);
104 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
105 &VNET_NAME(dad_enhanced), 0,
106 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
107
108 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to
109 transmit DAD packet */
110 #define V_dad_maxtry VNET(dad_maxtry)
111
112 /*
113 * Input a Neighbor Solicitation Message.
114 *
115 * Based on RFC 2461
116 * Based on RFC 2462 (duplicate address detection)
117 */
118 void
119 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
120 {
121 struct ifnet *ifp = m->m_pkthdr.rcvif;
122 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
123 struct nd_neighbor_solicit *nd_ns;
124 struct in6_addr saddr6 = ip6->ip6_src;
125 struct in6_addr daddr6 = ip6->ip6_dst;
126 struct in6_addr taddr6;
127 struct in6_addr myaddr6;
128 char *lladdr = NULL;
129 struct ifaddr *ifa = NULL;
130 int lladdrlen = 0;
131 int anycast = 0, proxy = 0, tentative = 0;
132 int tlladdr;
133 int rflag;
134 union nd_opts ndopts;
135 struct sockaddr_dl proxydl;
136 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
137
138 /* RFC 6980: Nodes MUST silently ignore fragments */
139 if(m->m_flags & M_FRAGMENTED)
140 goto freeit;
141
142 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
143 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
144 rflag = 0;
145 #ifndef PULLDOWN_TEST
146 IP6_EXTHDR_CHECK(m, off, icmp6len,);
147 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
148 #else
149 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
150 if (nd_ns == NULL) {
151 ICMP6STAT_INC(icp6s_tooshort);
152 return;
153 }
154 #endif
155 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
156 taddr6 = nd_ns->nd_ns_target;
157 if (in6_setscope(&taddr6, ifp, NULL) != 0)
158 goto bad;
159
160 if (ip6->ip6_hlim != 255) {
161 nd6log((LOG_ERR,
162 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
163 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
164 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
165 goto bad;
166 }
167
168 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
169 /* dst has to be a solicited node multicast address. */
170 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
171 /* don't check ifindex portion */
172 daddr6.s6_addr32[1] == 0 &&
173 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
174 daddr6.s6_addr8[12] == 0xff) {
175 ; /* good */
176 } else {
177 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
178 "(wrong ip6 dst)\n"));
179 goto bad;
180 }
181 } else if (!V_nd6_onlink_ns_rfc4861) {
182 struct sockaddr_in6 src_sa6;
183
184 /*
185 * According to recent IETF discussions, it is not a good idea
186 * to accept a NS from an address which would not be deemed
187 * to be a neighbor otherwise. This point is expected to be
188 * clarified in future revisions of the specification.
189 */
190 bzero(&src_sa6, sizeof(src_sa6));
191 src_sa6.sin6_family = AF_INET6;
192 src_sa6.sin6_len = sizeof(src_sa6);
193 src_sa6.sin6_addr = saddr6;
194 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
195 nd6log((LOG_INFO, "nd6_ns_input: "
196 "NS packet from non-neighbor\n"));
197 goto bad;
198 }
199 }
200
201 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
202 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
203 goto bad;
204 }
205
206 icmp6len -= sizeof(*nd_ns);
207 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
208 if (nd6_options(&ndopts) < 0) {
209 nd6log((LOG_INFO,
210 "nd6_ns_input: invalid ND option, ignored\n"));
211 /* nd6_options have incremented stats */
212 goto freeit;
213 }
214
215 if (ndopts.nd_opts_src_lladdr) {
216 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
217 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
218 }
219
220 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
221 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
222 "(link-layer address option)\n"));
223 goto bad;
224 }
225
226 /*
227 * Attaching target link-layer address to the NA?
228 * (RFC 2461 7.2.4)
229 *
230 * NS IP dst is unicast/anycast MUST NOT add
231 * NS IP dst is solicited-node multicast MUST add
232 *
233 * In implementation, we add target link-layer address by default.
234 * We do not add one in MUST NOT cases.
235 */
236 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
237 tlladdr = 0;
238 else
239 tlladdr = 1;
240
241 /*
242 * Target address (taddr6) must be either:
243 * (1) Valid unicast/anycast address for my receiving interface,
244 * (2) Unicast address for which I'm offering proxy service, or
245 * (3) "tentative" address on which DAD is being performed.
246 */
247 /* (1) and (3) check. */
248 if (ifp->if_carp)
249 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
250 else
251 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
252
253 /* (2) check. */
254 if (ifa == NULL) {
255 struct sockaddr_dl rt_gateway;
256 struct rt_addrinfo info;
257 struct sockaddr_in6 dst6;
258
259 bzero(&dst6, sizeof(dst6));
260 dst6.sin6_len = sizeof(struct sockaddr_in6);
261 dst6.sin6_family = AF_INET6;
262 dst6.sin6_addr = taddr6;
263
264 bzero(&rt_gateway, sizeof(rt_gateway));
265 rt_gateway.sdl_len = sizeof(rt_gateway);
266 bzero(&info, sizeof(info));
267 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
268
269 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6,
270 0, 0, &info) == 0) {
271 if ((info.rti_flags & RTF_ANNOUNCE) != 0 &&
272 rt_gateway.sdl_family == AF_LINK) {
273
274 /*
275 * proxy NDP for single entry
276 */
277 proxydl = *SDL(&rt_gateway);
278 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(
279 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
280 if (ifa)
281 proxy = 1;
282 }
283 }
284 }
285 if (ifa == NULL) {
286 /*
287 * We've got an NS packet, and we don't have that adddress
288 * assigned for us. We MUST silently ignore it.
289 * See RFC2461 7.2.3.
290 */
291 goto freeit;
292 }
293 myaddr6 = *IFA_IN6(ifa);
294 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
295 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
296 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
297 goto freeit;
298
299 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
300 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
301 "(if %d, NS packet %d)\n",
302 ip6_sprintf(ip6bufs, &taddr6),
303 ifp->if_addrlen, lladdrlen - 2));
304 goto bad;
305 }
306
307 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
308 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
309 ip6_sprintf(ip6bufs, &saddr6)));
310 goto freeit;
311 }
312
313 /*
314 * We have neighbor solicitation packet, with target address equals to
315 * one of my tentative address.
316 *
317 * src addr how to process?
318 * --- ---
319 * multicast of course, invalid (rejected in ip6_input)
320 * unicast somebody is doing address resolution -> ignore
321 * unspec dup address detection
322 *
323 * The processing is defined in RFC 2462.
324 */
325 if (tentative) {
326 /*
327 * If source address is unspecified address, it is for
328 * duplicate address detection.
329 *
330 * If not, the packet is for addess resolution;
331 * silently ignore it.
332 */
333 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
334 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
335
336 goto freeit;
337 }
338
339 /*
340 * If the source address is unspecified address, entries must not
341 * be created or updated.
342 * It looks that sender is performing DAD. Output NA toward
343 * all-node multicast address, to tell the sender that I'm using
344 * the address.
345 * S bit ("solicited") must be zero.
346 */
347 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
348 struct in6_addr in6_all;
349
350 in6_all = in6addr_linklocal_allnodes;
351 if (in6_setscope(&in6_all, ifp, NULL) != 0)
352 goto bad;
353 nd6_na_output_fib(ifp, &in6_all, &taddr6,
354 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
355 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
356 M_GETFIB(m));
357 goto freeit;
358 }
359
360 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
361 ND_NEIGHBOR_SOLICIT, 0);
362
363 nd6_na_output_fib(ifp, &saddr6, &taddr6,
364 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
365 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
366 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
367 freeit:
368 if (ifa != NULL)
369 ifa_free(ifa);
370 m_freem(m);
371 return;
372
373 bad:
374 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
375 ip6_sprintf(ip6bufs, &saddr6)));
376 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
377 ip6_sprintf(ip6bufs, &daddr6)));
378 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
379 ip6_sprintf(ip6bufs, &taddr6)));
380 ICMP6STAT_INC(icp6s_badns);
381 if (ifa != NULL)
382 ifa_free(ifa);
383 m_freem(m);
384 }
385
386 /*
387 * Output a Neighbor Solicitation Message. Caller specifies:
388 * - ICMP6 header source IP6 address
389 * - ND6 header target IP6 address
390 * - ND6 header source datalink address
391 *
392 * Based on RFC 2461
393 * Based on RFC 2462 (duplicate address detection)
394 *
395 * ln - for source address determination
396 * nonce - If non-NULL, NS is used for duplicate address detection and
397 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
398 */
399 static void
400 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
401 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
402 uint8_t *nonce, u_int fibnum)
403 {
404 struct mbuf *m;
405 struct m_tag *mtag;
406 struct ip6_hdr *ip6;
407 struct nd_neighbor_solicit *nd_ns;
408 struct ip6_moptions im6o;
409 int icmp6len;
410 int maxlen;
411 caddr_t mac;
412
413 if (IN6_IS_ADDR_MULTICAST(taddr6))
414 return;
415
416 /* estimate the size of message */
417 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
418 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
419 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
420 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
421 __func__, max_linkhdr, maxlen, MCLBYTES));
422
423 if (max_linkhdr + maxlen > MHLEN)
424 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
425 else
426 m = m_gethdr(M_NOWAIT, MT_DATA);
427 if (m == NULL)
428 return;
429 M_SETFIB(m, fibnum);
430
431 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
432 m->m_flags |= M_MCAST;
433 im6o.im6o_multicast_ifp = ifp;
434 im6o.im6o_multicast_hlim = 255;
435 im6o.im6o_multicast_loop = 0;
436 }
437
438 icmp6len = sizeof(*nd_ns);
439 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
440 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
441
442 /* fill neighbor solicitation packet */
443 ip6 = mtod(m, struct ip6_hdr *);
444 ip6->ip6_flow = 0;
445 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
446 ip6->ip6_vfc |= IPV6_VERSION;
447 /* ip6->ip6_plen will be set later */
448 ip6->ip6_nxt = IPPROTO_ICMPV6;
449 ip6->ip6_hlim = 255;
450 if (daddr6)
451 ip6->ip6_dst = *daddr6;
452 else {
453 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
454 ip6->ip6_dst.s6_addr16[1] = 0;
455 ip6->ip6_dst.s6_addr32[1] = 0;
456 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
457 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
458 ip6->ip6_dst.s6_addr8[12] = 0xff;
459 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
460 goto bad;
461 }
462 if (nonce == NULL) {
463 struct ifaddr *ifa = NULL;
464
465 /*
466 * RFC2461 7.2.2:
467 * "If the source address of the packet prompting the
468 * solicitation is the same as one of the addresses assigned
469 * to the outgoing interface, that address SHOULD be placed
470 * in the IP Source Address of the outgoing solicitation.
471 * Otherwise, any one of the addresses assigned to the
472 * interface should be used."
473 *
474 * We use the source address for the prompting packet
475 * (saddr6), if saddr6 belongs to the outgoing interface.
476 * Otherwise, we perform the source address selection as usual.
477 */
478
479 if (saddr6 != NULL)
480 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
481 if (ifa != NULL) {
482 /* ip6_src set already. */
483 ip6->ip6_src = *saddr6;
484 ifa_free(ifa);
485 } else {
486 int error;
487 struct in6_addr dst6, src6;
488 uint32_t scopeid;
489
490 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
491 error = in6_selectsrc_addr(fibnum, &dst6,
492 scopeid, ifp, &src6, NULL);
493 if (error) {
494 char ip6buf[INET6_ADDRSTRLEN];
495 nd6log((LOG_DEBUG, "%s: source can't be "
496 "determined: dst=%s, error=%d\n", __func__,
497 ip6_sprintf(ip6buf, &dst6),
498 error));
499 goto bad;
500 }
501 ip6->ip6_src = src6;
502 }
503 } else {
504 /*
505 * Source address for DAD packet must always be IPv6
506 * unspecified address. (0::0)
507 * We actually don't have to 0-clear the address (we did it
508 * above), but we do so here explicitly to make the intention
509 * clearer.
510 */
511 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
512 }
513 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
514 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
515 nd_ns->nd_ns_code = 0;
516 nd_ns->nd_ns_reserved = 0;
517 nd_ns->nd_ns_target = *taddr6;
518 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
519
520 /*
521 * Add source link-layer address option.
522 *
523 * spec implementation
524 * --- ---
525 * DAD packet MUST NOT do not add the option
526 * there's no link layer address:
527 * impossible do not add the option
528 * there's link layer address:
529 * Multicast NS MUST add one add the option
530 * Unicast NS SHOULD add one add the option
531 */
532 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) {
533 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
534 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
535 /* 8 byte alignments... */
536 optlen = (optlen + 7) & ~7;
537
538 m->m_pkthdr.len += optlen;
539 m->m_len += optlen;
540 icmp6len += optlen;
541 bzero((caddr_t)nd_opt, optlen);
542 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
543 nd_opt->nd_opt_len = optlen >> 3;
544 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
545 }
546 /*
547 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
548 * This behavior is documented as Enhanced Duplicate Address
549 * Detection in RFC 7527.
550 * net.inet6.ip6.dad_enhanced=0 disables this.
551 */
552 if (V_dad_enhanced != 0 && nonce != NULL) {
553 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
554 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
555 /* 8-byte alignment is required. */
556 optlen = (optlen + 7) & ~7;
557
558 m->m_pkthdr.len += optlen;
559 m->m_len += optlen;
560 icmp6len += optlen;
561 bzero((caddr_t)nd_opt, optlen);
562 nd_opt->nd_opt_type = ND_OPT_NONCE;
563 nd_opt->nd_opt_len = optlen >> 3;
564 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
565 }
566 ip6->ip6_plen = htons((u_short)icmp6len);
567 nd_ns->nd_ns_cksum = 0;
568 nd_ns->nd_ns_cksum =
569 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
570
571 if (send_sendso_input_hook != NULL) {
572 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
573 sizeof(unsigned short), M_NOWAIT);
574 if (mtag == NULL)
575 goto bad;
576 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
577 m_tag_prepend(m, mtag);
578 }
579
580 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
581 &im6o, NULL, NULL);
582 icmp6_ifstat_inc(ifp, ifs6_out_msg);
583 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
584 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
585
586 return;
587
588 bad:
589 m_freem(m);
590 }
591
592 #ifndef BURN_BRIDGES
593 void
594 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
595 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
596 {
597
598 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
599 }
600 #endif
601 /*
602 * Neighbor advertisement input handling.
603 *
604 * Based on RFC 2461
605 * Based on RFC 2462 (duplicate address detection)
606 *
607 * the following items are not implemented yet:
608 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
609 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
610 */
611 void
612 nd6_na_input(struct mbuf *m, int off, int icmp6len)
613 {
614 struct ifnet *ifp = m->m_pkthdr.rcvif;
615 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
616 struct nd_neighbor_advert *nd_na;
617 struct in6_addr daddr6 = ip6->ip6_dst;
618 struct in6_addr taddr6;
619 int flags;
620 int is_router;
621 int is_solicited;
622 int is_override;
623 char *lladdr = NULL;
624 int lladdrlen = 0;
625 int checklink = 0;
626 struct ifaddr *ifa;
627 struct llentry *ln = NULL;
628 union nd_opts ndopts;
629 struct mbuf *chain = NULL;
630 struct sockaddr_in6 sin6;
631 u_char linkhdr[LLE_MAX_LINKHDR];
632 size_t linkhdrsize;
633 int lladdr_off;
634 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
635
636 /* RFC 6980: Nodes MUST silently ignore fragments */
637 if(m->m_flags & M_FRAGMENTED)
638 goto freeit;
639
640 if (ip6->ip6_hlim != 255) {
641 nd6log((LOG_ERR,
642 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
643 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
644 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
645 goto bad;
646 }
647
648 #ifndef PULLDOWN_TEST
649 IP6_EXTHDR_CHECK(m, off, icmp6len,);
650 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
651 #else
652 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
653 if (nd_na == NULL) {
654 ICMP6STAT_INC(icp6s_tooshort);
655 return;
656 }
657 #endif
658
659 flags = nd_na->nd_na_flags_reserved;
660 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
661 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
662 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
663 memset(&sin6, 0, sizeof(sin6));
664
665 taddr6 = nd_na->nd_na_target;
666 if (in6_setscope(&taddr6, ifp, NULL))
667 goto bad; /* XXX: impossible */
668
669 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
670 nd6log((LOG_ERR,
671 "nd6_na_input: invalid target address %s\n",
672 ip6_sprintf(ip6bufs, &taddr6)));
673 goto bad;
674 }
675 if (IN6_IS_ADDR_MULTICAST(&daddr6))
676 if (is_solicited) {
677 nd6log((LOG_ERR,
678 "nd6_na_input: a solicited adv is multicasted\n"));
679 goto bad;
680 }
681
682 icmp6len -= sizeof(*nd_na);
683 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
684 if (nd6_options(&ndopts) < 0) {
685 nd6log((LOG_INFO,
686 "nd6_na_input: invalid ND option, ignored\n"));
687 /* nd6_options have incremented stats */
688 goto freeit;
689 }
690
691 if (ndopts.nd_opts_tgt_lladdr) {
692 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
693 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
694 }
695
696 /*
697 * This effectively disables the DAD check on a non-master CARP
698 * address.
699 */
700 if (ifp->if_carp)
701 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
702 else
703 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
704
705 /*
706 * Target address matches one of my interface address.
707 *
708 * If my address is tentative, this means that there's somebody
709 * already using the same address as mine. This indicates DAD failure.
710 * This is defined in RFC 2462.
711 *
712 * Otherwise, process as defined in RFC 2461.
713 */
714 if (ifa
715 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
716 nd6_dad_na_input(ifa);
717 ifa_free(ifa);
718 goto freeit;
719 }
720
721 /* Just for safety, maybe unnecessary. */
722 if (ifa) {
723 ifa_free(ifa);
724 log(LOG_ERR,
725 "nd6_na_input: duplicate IP6 address %s\n",
726 ip6_sprintf(ip6bufs, &taddr6));
727 goto freeit;
728 }
729
730 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
731 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
732 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
733 ifp->if_addrlen, lladdrlen - 2));
734 goto bad;
735 }
736
737 /*
738 * If no neighbor cache entry is found, NA SHOULD silently be
739 * discarded.
740 */
741 IF_AFDATA_RLOCK(ifp);
742 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
743 IF_AFDATA_RUNLOCK(ifp);
744 if (ln == NULL) {
745 goto freeit;
746 }
747
748 /*
749 * Do not try to override static entry.
750 */
751 if (ln->la_flags & LLE_STATIC)
752 goto freeit;
753
754 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
755 /*
756 * If the link-layer has address, and no lladdr option came,
757 * discard the packet.
758 */
759 if (ifp->if_addrlen && lladdr == NULL) {
760 goto freeit;
761 }
762
763 /*
764 * Record link-layer address, and update the state.
765 */
766 linkhdrsize = sizeof(linkhdr);
767 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
768 linkhdr, &linkhdrsize, &lladdr_off) != 0)
769 return;
770
771 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
772 lladdr_off) == 0) {
773 ln = NULL;
774 goto freeit;
775 }
776 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
777 if (is_solicited)
778 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
779 else
780 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
781 if ((ln->ln_router = is_router) != 0) {
782 /*
783 * This means a router's state has changed from
784 * non-reachable to probably reachable, and might
785 * affect the status of associated prefixes..
786 */
787 checklink = 1;
788 }
789 } else {
790 int llchange;
791
792 /*
793 * Check if the link-layer address has changed or not.
794 */
795 if (lladdr == NULL)
796 llchange = 0;
797 else {
798 if (ln->la_flags & LLE_VALID) {
799 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
800 llchange = 1;
801 else
802 llchange = 0;
803 } else
804 llchange = 1;
805 }
806
807 /*
808 * This is VERY complex. Look at it with care.
809 *
810 * override solicit lladdr llchange action
811 * (L: record lladdr)
812 *
813 * 0 0 n -- (2c)
814 * 0 0 y n (2b) L
815 * 0 0 y y (1) REACHABLE->STALE
816 * 0 1 n -- (2c) *->REACHABLE
817 * 0 1 y n (2b) L *->REACHABLE
818 * 0 1 y y (1) REACHABLE->STALE
819 * 1 0 n -- (2a)
820 * 1 0 y n (2a) L
821 * 1 0 y y (2a) L *->STALE
822 * 1 1 n -- (2a) *->REACHABLE
823 * 1 1 y n (2a) L *->REACHABLE
824 * 1 1 y y (2a) L *->REACHABLE
825 */
826 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
827 /*
828 * If state is REACHABLE, make it STALE.
829 * no other updates should be done.
830 */
831 if (ln->ln_state == ND6_LLINFO_REACHABLE)
832 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
833 goto freeit;
834 } else if (is_override /* (2a) */
835 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
836 || lladdr == NULL) { /* (2c) */
837 /*
838 * Update link-local address, if any.
839 */
840 if (lladdr != NULL) {
841 linkhdrsize = sizeof(linkhdr);
842 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
843 linkhdr, &linkhdrsize, &lladdr_off) != 0)
844 goto freeit;
845 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
846 linkhdrsize, lladdr_off) == 0) {
847 ln = NULL;
848 goto freeit;
849 }
850 EVENTHANDLER_INVOKE(lle_event, ln,
851 LLENTRY_RESOLVED);
852 }
853
854 /*
855 * If solicited, make the state REACHABLE.
856 * If not solicited and the link-layer address was
857 * changed, make it STALE.
858 */
859 if (is_solicited)
860 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
861 else {
862 if (lladdr != NULL && llchange)
863 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
864 }
865 }
866
867 if (ln->ln_router && !is_router) {
868 /*
869 * The peer dropped the router flag.
870 * Remove the sender from the Default Router List and
871 * update the Destination Cache entries.
872 */
873 struct ifnet *nd6_ifp;
874
875 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
876 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
877 (ND_IFINFO(nd6_ifp)->flags &
878 ND6_IFF_ACCEPT_RTADV) != 0)
879 /*
880 * Even if the neighbor is not in the default
881 * router list, the neighbor may be used as a
882 * next hop for some destinations (e.g. redirect
883 * case). So we must call rt6_flush explicitly.
884 */
885 rt6_flush(&ip6->ip6_src, ifp);
886 }
887 ln->ln_router = is_router;
888 }
889 /* XXX - QL
890 * Does this matter?
891 * rt->rt_flags &= ~RTF_REJECT;
892 */
893 ln->la_asked = 0;
894 if (ln->la_hold != NULL)
895 nd6_grab_holdchain(ln, &chain, &sin6);
896 freeit:
897 if (ln != NULL)
898 LLE_WUNLOCK(ln);
899
900 if (chain != NULL)
901 nd6_flush_holdchain(ifp, ifp, chain, &sin6);
902
903 if (checklink)
904 pfxlist_onlink_check();
905
906 m_freem(m);
907 return;
908
909 bad:
910 if (ln != NULL)
911 LLE_WUNLOCK(ln);
912
913 ICMP6STAT_INC(icp6s_badna);
914 m_freem(m);
915 }
916
917 /*
918 * Neighbor advertisement output handling.
919 *
920 * Based on RFC 2461
921 *
922 * the following items are not implemented yet:
923 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
924 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
925 *
926 * tlladdr - 1 if include target link-layer address
927 * sdl0 - sockaddr_dl (= proxy NA) or NULL
928 */
929 static void
930 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
931 const struct in6_addr *taddr6, u_long flags, int tlladdr,
932 struct sockaddr *sdl0, u_int fibnum)
933 {
934 struct mbuf *m;
935 struct m_tag *mtag;
936 struct ip6_hdr *ip6;
937 struct nd_neighbor_advert *nd_na;
938 struct ip6_moptions im6o;
939 struct in6_addr daddr6, dst6, src6;
940 uint32_t scopeid;
941
942 int icmp6len, maxlen, error;
943 caddr_t mac = NULL;
944
945 daddr6 = *daddr6_0; /* make a local copy for modification */
946
947 /* estimate the size of message */
948 maxlen = sizeof(*ip6) + sizeof(*nd_na);
949 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
950 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
951 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
952 __func__, max_linkhdr, maxlen, MCLBYTES));
953
954 if (max_linkhdr + maxlen > MHLEN)
955 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
956 else
957 m = m_gethdr(M_NOWAIT, MT_DATA);
958 if (m == NULL)
959 return;
960 M_SETFIB(m, fibnum);
961
962 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
963 m->m_flags |= M_MCAST;
964 im6o.im6o_multicast_ifp = ifp;
965 im6o.im6o_multicast_hlim = 255;
966 im6o.im6o_multicast_loop = 0;
967 }
968
969 icmp6len = sizeof(*nd_na);
970 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
971 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
972
973 /* fill neighbor advertisement packet */
974 ip6 = mtod(m, struct ip6_hdr *);
975 ip6->ip6_flow = 0;
976 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
977 ip6->ip6_vfc |= IPV6_VERSION;
978 ip6->ip6_nxt = IPPROTO_ICMPV6;
979 ip6->ip6_hlim = 255;
980 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
981 /* reply to DAD */
982 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
983 daddr6.s6_addr16[1] = 0;
984 daddr6.s6_addr32[1] = 0;
985 daddr6.s6_addr32[2] = 0;
986 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
987 if (in6_setscope(&daddr6, ifp, NULL))
988 goto bad;
989
990 flags &= ~ND_NA_FLAG_SOLICITED;
991 }
992 ip6->ip6_dst = daddr6;
993
994 /*
995 * Select a source whose scope is the same as that of the dest.
996 */
997 in6_splitscope(&daddr6, &dst6, &scopeid);
998 error = in6_selectsrc_addr(fibnum, &dst6,
999 scopeid, ifp, &src6, NULL);
1000 if (error) {
1001 char ip6buf[INET6_ADDRSTRLEN];
1002 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1003 "determined: dst=%s, error=%d\n",
1004 ip6_sprintf(ip6buf, &daddr6), error));
1005 goto bad;
1006 }
1007 ip6->ip6_src = src6;
1008 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1009 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1010 nd_na->nd_na_code = 0;
1011 nd_na->nd_na_target = *taddr6;
1012 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1013
1014 /*
1015 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1016 * see nd6_ns_input() for details.
1017 * Basically, if NS packet is sent to unicast/anycast addr,
1018 * target lladdr option SHOULD NOT be included.
1019 */
1020 if (tlladdr) {
1021 /*
1022 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1023 * lladdr in sdl0. If we are not proxying (sending NA for
1024 * my address) use lladdr configured for the interface.
1025 */
1026 if (sdl0 == NULL) {
1027 if (ifp->if_carp)
1028 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1029 if (mac == NULL)
1030 mac = nd6_ifptomac(ifp);
1031 } else if (sdl0->sa_family == AF_LINK) {
1032 struct sockaddr_dl *sdl;
1033 sdl = (struct sockaddr_dl *)sdl0;
1034 if (sdl->sdl_alen == ifp->if_addrlen)
1035 mac = LLADDR(sdl);
1036 }
1037 }
1038 if (tlladdr && mac) {
1039 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1040 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1041
1042 /* roundup to 8 bytes alignment! */
1043 optlen = (optlen + 7) & ~7;
1044
1045 m->m_pkthdr.len += optlen;
1046 m->m_len += optlen;
1047 icmp6len += optlen;
1048 bzero((caddr_t)nd_opt, optlen);
1049 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1050 nd_opt->nd_opt_len = optlen >> 3;
1051 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1052 } else
1053 flags &= ~ND_NA_FLAG_OVERRIDE;
1054
1055 ip6->ip6_plen = htons((u_short)icmp6len);
1056 nd_na->nd_na_flags_reserved = flags;
1057 nd_na->nd_na_cksum = 0;
1058 nd_na->nd_na_cksum =
1059 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1060
1061 if (send_sendso_input_hook != NULL) {
1062 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1063 sizeof(unsigned short), M_NOWAIT);
1064 if (mtag == NULL)
1065 goto bad;
1066 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1067 m_tag_prepend(m, mtag);
1068 }
1069
1070 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1071 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1072 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1073 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1074
1075 return;
1076
1077 bad:
1078 m_freem(m);
1079 }
1080
1081 #ifndef BURN_BRIDGES
1082 void
1083 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1084 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1085 struct sockaddr *sdl0)
1086 {
1087
1088 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1089 RT_DEFAULT_FIB);
1090 }
1091 #endif
1092
1093 caddr_t
1094 nd6_ifptomac(struct ifnet *ifp)
1095 {
1096 switch (ifp->if_type) {
1097 case IFT_ARCNET:
1098 case IFT_ETHER:
1099 case IFT_FDDI:
1100 case IFT_IEEE1394:
1101 case IFT_L2VLAN:
1102 case IFT_IEEE80211:
1103 case IFT_INFINIBAND:
1104 case IFT_BRIDGE:
1105 case IFT_ISO88025:
1106 return IF_LLADDR(ifp);
1107 default:
1108 return NULL;
1109 }
1110 }
1111
1112 struct dadq {
1113 TAILQ_ENTRY(dadq) dad_list;
1114 struct ifaddr *dad_ifa;
1115 int dad_count; /* max NS to send */
1116 int dad_ns_tcount; /* # of trials to send NS */
1117 int dad_ns_ocount; /* NS sent so far */
1118 int dad_ns_icount;
1119 int dad_na_icount;
1120 int dad_ns_lcount; /* looped back NS */
1121 int dad_loopbackprobe; /* probing state for loopback detection */
1122 struct callout dad_timer_ch;
1123 struct vnet *dad_vnet;
1124 u_int dad_refcnt;
1125 #define ND_OPT_NONCE_LEN32 \
1126 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1127 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1128 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */
1129 };
1130
1131 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
1132 static VNET_DEFINE(struct rwlock, dad_rwlock);
1133 #define V_dadq VNET(dadq)
1134 #define V_dad_rwlock VNET(dad_rwlock)
1135
1136 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock)
1137 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock)
1138 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock)
1139 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock)
1140
1141 static void
1142 nd6_dad_add(struct dadq *dp)
1143 {
1144
1145 DADQ_WLOCK();
1146 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1147 dp->dad_ondadq = true;
1148 DADQ_WUNLOCK();
1149 }
1150
1151 static void
1152 nd6_dad_del(struct dadq *dp)
1153 {
1154
1155 DADQ_WLOCK();
1156 if (dp->dad_ondadq) {
1157 /*
1158 * Remove dp from the dadq and release the dadq's
1159 * reference.
1160 */
1161 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1162 dp->dad_ondadq = false;
1163 DADQ_WUNLOCK();
1164 nd6_dad_rele(dp);
1165 } else
1166 DADQ_WUNLOCK();
1167 }
1168
1169 static struct dadq *
1170 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
1171 {
1172 struct dadq *dp;
1173
1174 DADQ_RLOCK();
1175 TAILQ_FOREACH(dp, &V_dadq, dad_list) {
1176 if (dp->dad_ifa != ifa)
1177 continue;
1178 /*
1179 * Skip if the nonce matches the received one.
1180 * +2 in the length is required because of type and
1181 * length fields are included in a header.
1182 */
1183 if (n != NULL &&
1184 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
1185 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
1186 ND_OPT_NONCE_LEN) == 0) {
1187 dp->dad_ns_lcount++;
1188 continue;
1189 }
1190 refcount_acquire(&dp->dad_refcnt);
1191 break;
1192 }
1193 DADQ_RUNLOCK();
1194
1195 return (dp);
1196 }
1197
1198 static void
1199 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns)
1200 {
1201
1202 if (send_ns != 0)
1203 nd6_dad_ns_output(dp);
1204 callout_reset(&dp->dad_timer_ch, ticks,
1205 (void (*)(void *))nd6_dad_timer, (void *)dp);
1206 }
1207
1208 static void
1209 nd6_dad_stoptimer(struct dadq *dp)
1210 {
1211
1212 callout_drain(&dp->dad_timer_ch);
1213 }
1214
1215 static void
1216 nd6_dad_rele(struct dadq *dp)
1217 {
1218
1219 if (refcount_release(&dp->dad_refcnt)) {
1220 ifa_free(dp->dad_ifa);
1221 free(dp, M_IP6NDP);
1222 }
1223 }
1224
1225 void
1226 nd6_dad_init(void)
1227 {
1228
1229 rw_init(&V_dad_rwlock, "nd6 DAD queue");
1230 TAILQ_INIT(&V_dadq);
1231 }
1232
1233 /*
1234 * Start Duplicate Address Detection (DAD) for specified interface address.
1235 */
1236 void
1237 nd6_dad_start(struct ifaddr *ifa, int delay)
1238 {
1239 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1240 struct dadq *dp;
1241 char ip6buf[INET6_ADDRSTRLEN];
1242
1243 /*
1244 * If we don't need DAD, don't do it.
1245 * There are several cases:
1246 * - DAD is disabled (ip6_dad_count == 0)
1247 * - the interface address is anycast
1248 */
1249 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1250 log(LOG_DEBUG,
1251 "nd6_dad_start: called with non-tentative address "
1252 "%s(%s)\n",
1253 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1254 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1255 return;
1256 }
1257 if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1258 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1259 return;
1260 }
1261 if (!V_ip6_dad_count) {
1262 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1263 return;
1264 }
1265 if (ifa->ifa_ifp == NULL)
1266 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1267 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) {
1268 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1269 return;
1270 }
1271 if (!(ifa->ifa_ifp->if_flags & IFF_UP) ||
1272 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) ||
1273 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) {
1274 ia->ia6_flags |= IN6_IFF_TENTATIVE;
1275 return;
1276 }
1277 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1278 /*
1279 * DAD is already in progress. Let the existing entry
1280 * finish it.
1281 */
1282 nd6_dad_rele(dp);
1283 return;
1284 }
1285
1286 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1287 if (dp == NULL) {
1288 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1289 "%s(%s)\n",
1290 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1291 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1292 return;
1293 }
1294 callout_init(&dp->dad_timer_ch, 0);
1295 #ifdef VIMAGE
1296 dp->dad_vnet = curvnet;
1297 #endif
1298 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1299 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1300
1301 /*
1302 * Send NS packet for DAD, ip6_dad_count times.
1303 * Note that we must delay the first transmission, if this is the
1304 * first packet to be sent from the interface after interface
1305 * (re)initialization.
1306 */
1307 dp->dad_ifa = ifa;
1308 ifa_ref(dp->dad_ifa);
1309 dp->dad_count = V_ip6_dad_count;
1310 dp->dad_ns_icount = dp->dad_na_icount = 0;
1311 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1312 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1313
1314 /* Add this to the dadq and add a reference for the dadq. */
1315 refcount_init(&dp->dad_refcnt, 1);
1316 nd6_dad_add(dp);
1317 nd6_dad_starttimer(dp, delay, 0);
1318 }
1319
1320 /*
1321 * terminate DAD unconditionally. used for address removals.
1322 */
1323 void
1324 nd6_dad_stop(struct ifaddr *ifa)
1325 {
1326 struct dadq *dp;
1327
1328 dp = nd6_dad_find(ifa, NULL);
1329 if (!dp) {
1330 /* DAD wasn't started yet */
1331 return;
1332 }
1333
1334 nd6_dad_stoptimer(dp);
1335 nd6_dad_del(dp);
1336
1337 /* Release this function's reference, acquired by nd6_dad_find(). */
1338 nd6_dad_rele(dp);
1339 }
1340
1341 static void
1342 nd6_dad_timer(struct dadq *dp)
1343 {
1344 CURVNET_SET(dp->dad_vnet);
1345 struct ifaddr *ifa = dp->dad_ifa;
1346 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1347 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1348 char ip6buf[INET6_ADDRSTRLEN];
1349
1350 /* Sanity check */
1351 if (ia == NULL) {
1352 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1353 goto err;
1354 }
1355 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
1356 /* Do not need DAD for ifdisabled interface. */
1357 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1358 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1359 goto err;
1360 }
1361 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1362 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1363 "%s(%s)\n",
1364 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1365 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1366 goto err;
1367 }
1368 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1369 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1370 "%s(%s)\n",
1371 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1372 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1373 goto err;
1374 }
1375
1376 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1377 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1378 (((ifp->if_flags & IFF_UP) == 0) ||
1379 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1380 nd6log((LOG_INFO, "%s: could not run DAD "
1381 "because the interface was down or not running.\n",
1382 if_name(ifa->ifa_ifp)));
1383 goto err;
1384 }
1385
1386 /* Need more checks? */
1387 if (dp->dad_ns_ocount < dp->dad_count) {
1388 /*
1389 * We have more NS to go. Send NS packet for DAD.
1390 */
1391 nd6_dad_starttimer(dp,
1392 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1);
1393 goto done;
1394 } else {
1395 /*
1396 * We have transmitted sufficient number of DAD packets.
1397 * See what we've got.
1398 */
1399 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0)
1400 /* We've seen NS or NA, means DAD has failed. */
1401 nd6_dad_duplicated(ifa, dp);
1402 else if (V_dad_enhanced != 0 &&
1403 dp->dad_ns_lcount > 0 &&
1404 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1405 /*
1406 * Sec. 4.1 in RFC 7527 requires transmission of
1407 * additional probes until the loopback condition
1408 * becomes clear when a looped back probe is detected.
1409 */
1410 log(LOG_ERR, "%s: a looped back NS message is "
1411 "detected during DAD for %s. "
1412 "Another DAD probes are being sent.\n",
1413 if_name(ifa->ifa_ifp),
1414 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1415 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1416 /*
1417 * Send an NS immediately and increase dad_count by
1418 * V_nd6_mmaxtries - 1.
1419 */
1420 dp->dad_count =
1421 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1422 nd6_dad_starttimer(dp,
1423 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000,
1424 1);
1425 goto done;
1426 } else {
1427 /*
1428 * We are done with DAD. No NA came, no NS came.
1429 * No duplicate address found. Check IFDISABLED flag
1430 * again in case that it is changed between the
1431 * beginning of this function and here.
1432 */
1433 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
1434 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1435
1436 nd6log((LOG_DEBUG,
1437 "%s: DAD complete for %s - no duplicates found\n",
1438 if_name(ifa->ifa_ifp),
1439 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1440 if (dp->dad_ns_lcount > 0)
1441 log(LOG_ERR, "%s: DAD completed while "
1442 "a looped back NS message is detected "
1443 "during DAD for %s.\n",
1444 if_name(ifa->ifa_ifp),
1445 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1446 }
1447 }
1448 err:
1449 nd6_dad_del(dp);
1450 done:
1451 CURVNET_RESTORE();
1452 }
1453
1454 static void
1455 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1456 {
1457 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1458 struct ifnet *ifp;
1459 char ip6buf[INET6_ADDRSTRLEN];
1460
1461 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1462 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1463 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1464 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1465 dp->dad_na_icount);
1466
1467 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1468 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1469
1470 ifp = ifa->ifa_ifp;
1471 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1472 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1473 log(LOG_ERR, "%s: manual intervention required\n",
1474 if_name(ifp));
1475
1476 /*
1477 * If the address is a link-local address formed from an interface
1478 * identifier based on the hardware address which is supposed to be
1479 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1480 * operation on the interface SHOULD be disabled.
1481 * [RFC 4862, Section 5.4.5]
1482 */
1483 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1484 struct in6_addr in6;
1485
1486 /*
1487 * To avoid over-reaction, we only apply this logic when we are
1488 * very sure that hardware addresses are supposed to be unique.
1489 */
1490 switch (ifp->if_type) {
1491 case IFT_ETHER:
1492 case IFT_FDDI:
1493 case IFT_ATM:
1494 case IFT_IEEE1394:
1495 case IFT_IEEE80211:
1496 case IFT_INFINIBAND:
1497 in6 = ia->ia_addr.sin6_addr;
1498 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1499 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1500 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1501 log(LOG_ERR, "%s: possible hardware address "
1502 "duplication detected, disable IPv6\n",
1503 if_name(ifp));
1504 }
1505 break;
1506 }
1507 }
1508 }
1509
1510 static void
1511 nd6_dad_ns_output(struct dadq *dp)
1512 {
1513 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1514 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1515 int i;
1516
1517 dp->dad_ns_tcount++;
1518 if ((ifp->if_flags & IFF_UP) == 0) {
1519 return;
1520 }
1521 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1522 return;
1523 }
1524
1525 dp->dad_ns_ocount++;
1526 if (V_dad_enhanced != 0) {
1527 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1528 dp->dad_nonce[i] = arc4random();
1529 /*
1530 * XXXHRS: Note that in the case that
1531 * DupAddrDetectTransmits > 1, multiple NS messages with
1532 * different nonces can be looped back in an unexpected
1533 * order. The current implementation recognizes only
1534 * the latest nonce on the sender side. Practically it
1535 * should work well in almost all cases.
1536 */
1537 }
1538 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1539 (uint8_t *)&dp->dad_nonce[0]);
1540 }
1541
1542 static void
1543 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1544 {
1545 struct in6_ifaddr *ia;
1546 struct ifnet *ifp;
1547 const struct in6_addr *taddr6;
1548 struct dadq *dp;
1549
1550 if (ifa == NULL)
1551 panic("ifa == NULL in nd6_dad_ns_input");
1552
1553 ia = (struct in6_ifaddr *)ifa;
1554 ifp = ifa->ifa_ifp;
1555 taddr6 = &ia->ia_addr.sin6_addr;
1556 /* Ignore Nonce option when Enhanced DAD is disabled. */
1557 if (V_dad_enhanced == 0)
1558 ndopt_nonce = NULL;
1559 dp = nd6_dad_find(ifa, ndopt_nonce);
1560 if (dp == NULL)
1561 return;
1562
1563 dp->dad_ns_icount++;
1564 nd6_dad_rele(dp);
1565 }
1566
1567 static void
1568 nd6_dad_na_input(struct ifaddr *ifa)
1569 {
1570 struct dadq *dp;
1571
1572 if (ifa == NULL)
1573 panic("ifa == NULL in nd6_dad_na_input");
1574
1575 dp = nd6_dad_find(ifa, NULL);
1576 if (dp != NULL) {
1577 dp->dad_na_icount++;
1578 nd6_dad_rele(dp);
1579 }
1580 }
Cache object: c8f10b68744f3386df62063585a3504e
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