1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD: releng/12.0/sys/netinet6/nd6_nbr.c 336676 2018-07-24 16:35:52Z andrew $");
36
37 #include "opt_inet.h"
38 #include "opt_inet6.h"
39 #include "opt_ipsec.h"
40 #include "opt_mpath.h"
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/malloc.h>
45 #include <sys/libkern.h>
46 #include <sys/lock.h>
47 #include <sys/rwlock.h>
48 #include <sys/mbuf.h>
49 #include <sys/socket.h>
50 #include <sys/sockio.h>
51 #include <sys/time.h>
52 #include <sys/kernel.h>
53 #include <sys/errno.h>
54 #include <sys/sysctl.h>
55 #include <sys/syslog.h>
56 #include <sys/queue.h>
57 #include <sys/callout.h>
58 #include <sys/refcount.h>
59
60 #include <net/if.h>
61 #include <net/if_types.h>
62 #include <net/if_dl.h>
63 #include <net/if_var.h>
64 #include <net/route.h>
65 #ifdef RADIX_MPATH
66 #include <net/radix_mpath.h>
67 #endif
68 #include <net/vnet.h>
69
70 #include <netinet/in.h>
71 #include <netinet/in_var.h>
72 #include <net/if_llatbl.h>
73 #include <netinet6/in6_var.h>
74 #include <netinet6/in6_ifattach.h>
75 #include <netinet/ip6.h>
76 #include <netinet6/ip6_var.h>
77 #include <netinet6/scope6_var.h>
78 #include <netinet6/nd6.h>
79 #include <netinet/icmp6.h>
80 #include <netinet/ip_carp.h>
81 #include <netinet6/send.h>
82
83 #define SDL(s) ((struct sockaddr_dl *)s)
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, int);
91 static void nd6_dad_stoptimer(struct dadq *);
92 static void nd6_dad_timer(struct dadq *);
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
102 VNET_DEFINE_STATIC(int, dad_enhanced) = 1;
103 #define V_dad_enhanced VNET(dad_enhanced)
104
105 SYSCTL_DECL(_net_inet6_ip6);
106 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
107 &VNET_NAME(dad_enhanced), 0,
108 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
109
110 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to
111 transmit DAD packet */
112 #define V_dad_maxtry VNET(dad_maxtry)
113
114 /*
115 * Input a Neighbor Solicitation Message.
116 *
117 * Based on RFC 2461
118 * Based on RFC 2462 (duplicate address detection)
119 */
120 void
121 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
122 {
123 struct ifnet *ifp = m->m_pkthdr.rcvif;
124 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
125 struct nd_neighbor_solicit *nd_ns;
126 struct in6_addr saddr6 = ip6->ip6_src;
127 struct in6_addr daddr6 = ip6->ip6_dst;
128 struct in6_addr taddr6;
129 struct in6_addr myaddr6;
130 char *lladdr = NULL;
131 struct ifaddr *ifa = NULL;
132 int lladdrlen = 0;
133 int anycast = 0, proxy = 0, tentative = 0;
134 int tlladdr;
135 int rflag;
136 union nd_opts ndopts;
137 struct sockaddr_dl proxydl;
138 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
139
140 /* RFC 6980: Nodes MUST silently ignore fragments */
141 if(m->m_flags & M_FRAGMENTED)
142 goto freeit;
143
144 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
145 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
146 rflag = 0;
147 #ifndef PULLDOWN_TEST
148 IP6_EXTHDR_CHECK(m, off, icmp6len,);
149 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
150 #else
151 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
152 if (nd_ns == NULL) {
153 ICMP6STAT_INC(icp6s_tooshort);
154 return;
155 }
156 #endif
157 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
158 taddr6 = nd_ns->nd_ns_target;
159 if (in6_setscope(&taddr6, ifp, NULL) != 0)
160 goto bad;
161
162 if (ip6->ip6_hlim != 255) {
163 nd6log((LOG_ERR,
164 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
165 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
166 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
167 goto bad;
168 }
169
170 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
171 /* dst has to be a solicited node multicast address. */
172 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
173 /* don't check ifindex portion */
174 daddr6.s6_addr32[1] == 0 &&
175 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
176 daddr6.s6_addr8[12] == 0xff) {
177 ; /* good */
178 } else {
179 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
180 "(wrong ip6 dst)\n"));
181 goto bad;
182 }
183 } else if (!V_nd6_onlink_ns_rfc4861) {
184 struct sockaddr_in6 src_sa6;
185
186 /*
187 * According to recent IETF discussions, it is not a good idea
188 * to accept a NS from an address which would not be deemed
189 * to be a neighbor otherwise. This point is expected to be
190 * clarified in future revisions of the specification.
191 */
192 bzero(&src_sa6, sizeof(src_sa6));
193 src_sa6.sin6_family = AF_INET6;
194 src_sa6.sin6_len = sizeof(src_sa6);
195 src_sa6.sin6_addr = saddr6;
196 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
197 nd6log((LOG_INFO, "nd6_ns_input: "
198 "NS packet from non-neighbor\n"));
199 goto bad;
200 }
201 }
202
203 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
204 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
205 goto bad;
206 }
207
208 icmp6len -= sizeof(*nd_ns);
209 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
210 if (nd6_options(&ndopts) < 0) {
211 nd6log((LOG_INFO,
212 "nd6_ns_input: invalid ND option, ignored\n"));
213 /* nd6_options have incremented stats */
214 goto freeit;
215 }
216
217 if (ndopts.nd_opts_src_lladdr) {
218 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
219 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
220 }
221
222 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
223 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
224 "(link-layer address option)\n"));
225 goto bad;
226 }
227
228 /*
229 * Attaching target link-layer address to the NA?
230 * (RFC 2461 7.2.4)
231 *
232 * NS IP dst is unicast/anycast MUST NOT add
233 * NS IP dst is solicited-node multicast MUST add
234 *
235 * In implementation, we add target link-layer address by default.
236 * We do not add one in MUST NOT cases.
237 */
238 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
239 tlladdr = 0;
240 else
241 tlladdr = 1;
242
243 /*
244 * Target address (taddr6) must be either:
245 * (1) Valid unicast/anycast address for my receiving interface,
246 * (2) Unicast address for which I'm offering proxy service, or
247 * (3) "tentative" address on which DAD is being performed.
248 */
249 /* (1) and (3) check. */
250 if (ifp->if_carp)
251 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
252 else
253 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
254
255 /* (2) check. */
256 if (ifa == NULL) {
257 struct sockaddr_dl rt_gateway;
258 struct rt_addrinfo info;
259 struct sockaddr_in6 dst6;
260
261 bzero(&dst6, sizeof(dst6));
262 dst6.sin6_len = sizeof(struct sockaddr_in6);
263 dst6.sin6_family = AF_INET6;
264 dst6.sin6_addr = taddr6;
265
266 bzero(&rt_gateway, sizeof(rt_gateway));
267 rt_gateway.sdl_len = sizeof(rt_gateway);
268 bzero(&info, sizeof(info));
269 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
270
271 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6,
272 0, 0, &info) == 0) {
273 if ((info.rti_flags & RTF_ANNOUNCE) != 0 &&
274 rt_gateway.sdl_family == AF_LINK) {
275
276 /*
277 * proxy NDP for single entry
278 */
279 proxydl = *SDL(&rt_gateway);
280 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(
281 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
282 if (ifa)
283 proxy = 1;
284 }
285 }
286 }
287 if (ifa == NULL) {
288 /*
289 * We've got an NS packet, and we don't have that adddress
290 * assigned for us. We MUST silently ignore it.
291 * See RFC2461 7.2.3.
292 */
293 goto freeit;
294 }
295 myaddr6 = *IFA_IN6(ifa);
296 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
297 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
298 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
299 goto freeit;
300
301 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
302 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
303 "(if %d, NS packet %d)\n",
304 ip6_sprintf(ip6bufs, &taddr6),
305 ifp->if_addrlen, lladdrlen - 2));
306 goto bad;
307 }
308
309 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
310 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
311 ip6_sprintf(ip6bufs, &saddr6)));
312 goto freeit;
313 }
314
315 /*
316 * We have neighbor solicitation packet, with target address equals to
317 * one of my tentative address.
318 *
319 * src addr how to process?
320 * --- ---
321 * multicast of course, invalid (rejected in ip6_input)
322 * unicast somebody is doing address resolution -> ignore
323 * unspec dup address detection
324 *
325 * The processing is defined in RFC 2462.
326 */
327 if (tentative) {
328 /*
329 * If source address is unspecified address, it is for
330 * duplicate address detection.
331 *
332 * If not, the packet is for addess resolution;
333 * silently ignore it.
334 */
335 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
336 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
337
338 goto freeit;
339 }
340
341 /*
342 * If the source address is unspecified address, entries must not
343 * be created or updated.
344 * It looks that sender is performing DAD. Output NA toward
345 * all-node multicast address, to tell the sender that I'm using
346 * the address.
347 * S bit ("solicited") must be zero.
348 */
349 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
350 struct in6_addr in6_all;
351
352 in6_all = in6addr_linklocal_allnodes;
353 if (in6_setscope(&in6_all, ifp, NULL) != 0)
354 goto bad;
355 nd6_na_output_fib(ifp, &in6_all, &taddr6,
356 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
357 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
358 M_GETFIB(m));
359 goto freeit;
360 }
361
362 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
363 ND_NEIGHBOR_SOLICIT, 0);
364
365 nd6_na_output_fib(ifp, &saddr6, &taddr6,
366 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
367 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
368 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
369 freeit:
370 if (ifa != NULL)
371 ifa_free(ifa);
372 m_freem(m);
373 return;
374
375 bad:
376 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
377 ip6_sprintf(ip6bufs, &saddr6)));
378 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
379 ip6_sprintf(ip6bufs, &daddr6)));
380 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
381 ip6_sprintf(ip6bufs, &taddr6)));
382 ICMP6STAT_INC(icp6s_badns);
383 if (ifa != NULL)
384 ifa_free(ifa);
385 m_freem(m);
386 }
387
388 /*
389 * Output a Neighbor Solicitation Message. Caller specifies:
390 * - ICMP6 header source IP6 address
391 * - ND6 header target IP6 address
392 * - ND6 header source datalink address
393 *
394 * Based on RFC 2461
395 * Based on RFC 2462 (duplicate address detection)
396 *
397 * ln - for source address determination
398 * nonce - If non-NULL, NS is used for duplicate address detection and
399 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
400 */
401 static void
402 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
403 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
404 uint8_t *nonce, u_int fibnum)
405 {
406 struct mbuf *m;
407 struct m_tag *mtag;
408 struct ip6_hdr *ip6;
409 struct nd_neighbor_solicit *nd_ns;
410 struct ip6_moptions im6o;
411 int icmp6len;
412 int maxlen;
413 caddr_t mac;
414
415 if (IN6_IS_ADDR_MULTICAST(taddr6))
416 return;
417
418 /* estimate the size of message */
419 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
420 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
421 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
422 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
423 __func__, max_linkhdr, maxlen, MCLBYTES));
424
425 if (max_linkhdr + maxlen > MHLEN)
426 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
427 else
428 m = m_gethdr(M_NOWAIT, MT_DATA);
429 if (m == NULL)
430 return;
431 M_SETFIB(m, fibnum);
432
433 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
434 m->m_flags |= M_MCAST;
435 im6o.im6o_multicast_ifp = ifp;
436 im6o.im6o_multicast_hlim = 255;
437 im6o.im6o_multicast_loop = 0;
438 }
439
440 icmp6len = sizeof(*nd_ns);
441 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
442 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
443
444 /* fill neighbor solicitation packet */
445 ip6 = mtod(m, struct ip6_hdr *);
446 ip6->ip6_flow = 0;
447 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
448 ip6->ip6_vfc |= IPV6_VERSION;
449 /* ip6->ip6_plen will be set later */
450 ip6->ip6_nxt = IPPROTO_ICMPV6;
451 ip6->ip6_hlim = 255;
452 if (daddr6)
453 ip6->ip6_dst = *daddr6;
454 else {
455 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
456 ip6->ip6_dst.s6_addr16[1] = 0;
457 ip6->ip6_dst.s6_addr32[1] = 0;
458 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
459 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
460 ip6->ip6_dst.s6_addr8[12] = 0xff;
461 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
462 goto bad;
463 }
464 if (nonce == NULL) {
465 struct ifaddr *ifa = NULL;
466
467 /*
468 * RFC2461 7.2.2:
469 * "If the source address of the packet prompting the
470 * solicitation is the same as one of the addresses assigned
471 * to the outgoing interface, that address SHOULD be placed
472 * in the IP Source Address of the outgoing solicitation.
473 * Otherwise, any one of the addresses assigned to the
474 * interface should be used."
475 *
476 * We use the source address for the prompting packet
477 * (saddr6), if saddr6 belongs to the outgoing interface.
478 * Otherwise, we perform the source address selection as usual.
479 */
480
481 if (saddr6 != NULL)
482 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
483 if (ifa != NULL) {
484 /* ip6_src set already. */
485 ip6->ip6_src = *saddr6;
486 ifa_free(ifa);
487 } else {
488 int error;
489 struct in6_addr dst6, src6;
490 uint32_t scopeid;
491
492 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
493 error = in6_selectsrc_addr(fibnum, &dst6,
494 scopeid, ifp, &src6, NULL);
495 if (error) {
496 char ip6buf[INET6_ADDRSTRLEN];
497 nd6log((LOG_DEBUG, "%s: source can't be "
498 "determined: dst=%s, error=%d\n", __func__,
499 ip6_sprintf(ip6buf, &dst6),
500 error));
501 goto bad;
502 }
503 ip6->ip6_src = src6;
504 }
505 } else {
506 /*
507 * Source address for DAD packet must always be IPv6
508 * unspecified address. (0::0)
509 * We actually don't have to 0-clear the address (we did it
510 * above), but we do so here explicitly to make the intention
511 * clearer.
512 */
513 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
514 }
515 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
516 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
517 nd_ns->nd_ns_code = 0;
518 nd_ns->nd_ns_reserved = 0;
519 nd_ns->nd_ns_target = *taddr6;
520 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
521
522 /*
523 * Add source link-layer address option.
524 *
525 * spec implementation
526 * --- ---
527 * DAD packet MUST NOT do not add the option
528 * there's no link layer address:
529 * impossible do not add the option
530 * there's link layer address:
531 * Multicast NS MUST add one add the option
532 * Unicast NS SHOULD add one add the option
533 */
534 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) {
535 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
536 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
537 /* 8 byte alignments... */
538 optlen = (optlen + 7) & ~7;
539
540 m->m_pkthdr.len += optlen;
541 m->m_len += optlen;
542 icmp6len += optlen;
543 bzero((caddr_t)nd_opt, optlen);
544 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
545 nd_opt->nd_opt_len = optlen >> 3;
546 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
547 }
548 /*
549 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
550 * This behavior is documented as Enhanced Duplicate Address
551 * Detection in RFC 7527.
552 * net.inet6.ip6.dad_enhanced=0 disables this.
553 */
554 if (V_dad_enhanced != 0 && nonce != NULL) {
555 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
556 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
557 /* 8-byte alignment is required. */
558 optlen = (optlen + 7) & ~7;
559
560 m->m_pkthdr.len += optlen;
561 m->m_len += optlen;
562 icmp6len += optlen;
563 bzero((caddr_t)nd_opt, optlen);
564 nd_opt->nd_opt_type = ND_OPT_NONCE;
565 nd_opt->nd_opt_len = optlen >> 3;
566 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
567 }
568 ip6->ip6_plen = htons((u_short)icmp6len);
569 nd_ns->nd_ns_cksum = 0;
570 nd_ns->nd_ns_cksum =
571 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
572
573 if (send_sendso_input_hook != NULL) {
574 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
575 sizeof(unsigned short), M_NOWAIT);
576 if (mtag == NULL)
577 goto bad;
578 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
579 m_tag_prepend(m, mtag);
580 }
581
582 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
583 &im6o, NULL, NULL);
584 icmp6_ifstat_inc(ifp, ifs6_out_msg);
585 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
586 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
587
588 return;
589
590 bad:
591 m_freem(m);
592 }
593
594 #ifndef BURN_BRIDGES
595 void
596 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
597 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
598 {
599
600 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
601 }
602 #endif
603 /*
604 * Neighbor advertisement input handling.
605 *
606 * Based on RFC 2461
607 * Based on RFC 2462 (duplicate address detection)
608 *
609 * the following items are not implemented yet:
610 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
611 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
612 */
613 void
614 nd6_na_input(struct mbuf *m, int off, int icmp6len)
615 {
616 struct ifnet *ifp = m->m_pkthdr.rcvif;
617 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
618 struct nd_neighbor_advert *nd_na;
619 struct in6_addr daddr6 = ip6->ip6_dst;
620 struct in6_addr taddr6;
621 int flags;
622 int is_router;
623 int is_solicited;
624 int is_override;
625 char *lladdr = NULL;
626 int lladdrlen = 0;
627 int checklink = 0;
628 struct ifaddr *ifa;
629 struct llentry *ln = NULL;
630 union nd_opts ndopts;
631 struct mbuf *chain = NULL;
632 struct sockaddr_in6 sin6;
633 u_char linkhdr[LLE_MAX_LINKHDR];
634 size_t linkhdrsize;
635 int lladdr_off;
636 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
637
638 /* RFC 6980: Nodes MUST silently ignore fragments */
639 if(m->m_flags & M_FRAGMENTED)
640 goto freeit;
641
642 if (ip6->ip6_hlim != 255) {
643 nd6log((LOG_ERR,
644 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
645 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
646 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
647 goto bad;
648 }
649
650 #ifndef PULLDOWN_TEST
651 IP6_EXTHDR_CHECK(m, off, icmp6len,);
652 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
653 #else
654 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
655 if (nd_na == NULL) {
656 ICMP6STAT_INC(icp6s_tooshort);
657 return;
658 }
659 #endif
660
661 flags = nd_na->nd_na_flags_reserved;
662 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
663 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
664 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
665 memset(&sin6, 0, sizeof(sin6));
666
667 taddr6 = nd_na->nd_na_target;
668 if (in6_setscope(&taddr6, ifp, NULL))
669 goto bad; /* XXX: impossible */
670
671 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
672 nd6log((LOG_ERR,
673 "nd6_na_input: invalid target address %s\n",
674 ip6_sprintf(ip6bufs, &taddr6)));
675 goto bad;
676 }
677 if (IN6_IS_ADDR_MULTICAST(&daddr6))
678 if (is_solicited) {
679 nd6log((LOG_ERR,
680 "nd6_na_input: a solicited adv is multicasted\n"));
681 goto bad;
682 }
683
684 icmp6len -= sizeof(*nd_na);
685 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
686 if (nd6_options(&ndopts) < 0) {
687 nd6log((LOG_INFO,
688 "nd6_na_input: invalid ND option, ignored\n"));
689 /* nd6_options have incremented stats */
690 goto freeit;
691 }
692
693 if (ndopts.nd_opts_tgt_lladdr) {
694 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
695 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
696 }
697
698 /*
699 * This effectively disables the DAD check on a non-master CARP
700 * address.
701 */
702 if (ifp->if_carp)
703 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
704 else
705 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
706
707 /*
708 * Target address matches one of my interface address.
709 *
710 * If my address is tentative, this means that there's somebody
711 * already using the same address as mine. This indicates DAD failure.
712 * This is defined in RFC 2462.
713 *
714 * Otherwise, process as defined in RFC 2461.
715 */
716 if (ifa
717 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
718 nd6_dad_na_input(ifa);
719 ifa_free(ifa);
720 goto freeit;
721 }
722
723 /* Just for safety, maybe unnecessary. */
724 if (ifa) {
725 ifa_free(ifa);
726 log(LOG_ERR,
727 "nd6_na_input: duplicate IP6 address %s\n",
728 ip6_sprintf(ip6bufs, &taddr6));
729 goto freeit;
730 }
731
732 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
733 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
734 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
735 ifp->if_addrlen, lladdrlen - 2));
736 goto bad;
737 }
738
739 /*
740 * If no neighbor cache entry is found, NA SHOULD silently be
741 * discarded.
742 */
743 IF_AFDATA_RLOCK(ifp);
744 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
745 IF_AFDATA_RUNLOCK(ifp);
746 if (ln == NULL) {
747 goto freeit;
748 }
749
750 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
751 /*
752 * If the link-layer has address, and no lladdr option came,
753 * discard the packet.
754 */
755 if (ifp->if_addrlen && lladdr == NULL) {
756 goto freeit;
757 }
758
759 /*
760 * Record link-layer address, and update the state.
761 */
762 linkhdrsize = sizeof(linkhdr);
763 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
764 linkhdr, &linkhdrsize, &lladdr_off) != 0)
765 return;
766
767 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
768 lladdr_off) == 0) {
769 ln = NULL;
770 goto freeit;
771 }
772 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
773 if (is_solicited)
774 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
775 else
776 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
777 if ((ln->ln_router = is_router) != 0) {
778 /*
779 * This means a router's state has changed from
780 * non-reachable to probably reachable, and might
781 * affect the status of associated prefixes..
782 */
783 checklink = 1;
784 }
785 } else {
786 int llchange;
787
788 /*
789 * Check if the link-layer address has changed or not.
790 */
791 if (lladdr == NULL)
792 llchange = 0;
793 else {
794 if (ln->la_flags & LLE_VALID) {
795 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
796 llchange = 1;
797 else
798 llchange = 0;
799 } else
800 llchange = 1;
801 }
802
803 /*
804 * This is VERY complex. Look at it with care.
805 *
806 * override solicit lladdr llchange action
807 * (L: record lladdr)
808 *
809 * 0 0 n -- (2c)
810 * 0 0 y n (2b) L
811 * 0 0 y y (1) REACHABLE->STALE
812 * 0 1 n -- (2c) *->REACHABLE
813 * 0 1 y n (2b) L *->REACHABLE
814 * 0 1 y y (1) REACHABLE->STALE
815 * 1 0 n -- (2a)
816 * 1 0 y n (2a) L
817 * 1 0 y y (2a) L *->STALE
818 * 1 1 n -- (2a) *->REACHABLE
819 * 1 1 y n (2a) L *->REACHABLE
820 * 1 1 y y (2a) L *->REACHABLE
821 */
822 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
823 /*
824 * If state is REACHABLE, make it STALE.
825 * no other updates should be done.
826 */
827 if (ln->ln_state == ND6_LLINFO_REACHABLE)
828 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
829 goto freeit;
830 } else if (is_override /* (2a) */
831 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
832 || lladdr == NULL) { /* (2c) */
833 /*
834 * Update link-local address, if any.
835 */
836 if (lladdr != NULL) {
837 linkhdrsize = sizeof(linkhdr);
838 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
839 linkhdr, &linkhdrsize, &lladdr_off) != 0)
840 goto freeit;
841 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
842 linkhdrsize, lladdr_off) == 0) {
843 ln = NULL;
844 goto freeit;
845 }
846 EVENTHANDLER_INVOKE(lle_event, ln,
847 LLENTRY_RESOLVED);
848 }
849
850 /*
851 * If solicited, make the state REACHABLE.
852 * If not solicited and the link-layer address was
853 * changed, make it STALE.
854 */
855 if (is_solicited)
856 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
857 else {
858 if (lladdr != NULL && llchange)
859 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
860 }
861 }
862
863 if (ln->ln_router && !is_router) {
864 /*
865 * The peer dropped the router flag.
866 * Remove the sender from the Default Router List and
867 * update the Destination Cache entries.
868 */
869 struct ifnet *nd6_ifp;
870
871 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
872 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
873 (ND_IFINFO(nd6_ifp)->flags &
874 ND6_IFF_ACCEPT_RTADV) != 0)
875 /*
876 * Even if the neighbor is not in the default
877 * router list, the neighbor may be used as a
878 * next hop for some destinations (e.g. redirect
879 * case). So we must call rt6_flush explicitly.
880 */
881 rt6_flush(&ip6->ip6_src, ifp);
882 }
883 ln->ln_router = is_router;
884 }
885 /* XXX - QL
886 * Does this matter?
887 * rt->rt_flags &= ~RTF_REJECT;
888 */
889 ln->la_asked = 0;
890 if (ln->la_hold != NULL)
891 nd6_grab_holdchain(ln, &chain, &sin6);
892 freeit:
893 if (ln != NULL)
894 LLE_WUNLOCK(ln);
895
896 if (chain != NULL)
897 nd6_flush_holdchain(ifp, chain, &sin6);
898
899 if (checklink)
900 pfxlist_onlink_check();
901
902 m_freem(m);
903 return;
904
905 bad:
906 if (ln != NULL)
907 LLE_WUNLOCK(ln);
908
909 ICMP6STAT_INC(icp6s_badna);
910 m_freem(m);
911 }
912
913 /*
914 * Neighbor advertisement output handling.
915 *
916 * Based on RFC 2461
917 *
918 * the following items are not implemented yet:
919 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
920 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
921 *
922 * tlladdr - 1 if include target link-layer address
923 * sdl0 - sockaddr_dl (= proxy NA) or NULL
924 */
925 static void
926 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
927 const struct in6_addr *taddr6, u_long flags, int tlladdr,
928 struct sockaddr *sdl0, u_int fibnum)
929 {
930 struct mbuf *m;
931 struct m_tag *mtag;
932 struct ip6_hdr *ip6;
933 struct nd_neighbor_advert *nd_na;
934 struct ip6_moptions im6o;
935 struct in6_addr daddr6, dst6, src6;
936 uint32_t scopeid;
937
938 int icmp6len, maxlen, error;
939 caddr_t mac = NULL;
940
941 daddr6 = *daddr6_0; /* make a local copy for modification */
942
943 /* estimate the size of message */
944 maxlen = sizeof(*ip6) + sizeof(*nd_na);
945 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
946 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
947 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
948 __func__, max_linkhdr, maxlen, MCLBYTES));
949
950 if (max_linkhdr + maxlen > MHLEN)
951 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
952 else
953 m = m_gethdr(M_NOWAIT, MT_DATA);
954 if (m == NULL)
955 return;
956 M_SETFIB(m, fibnum);
957
958 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
959 m->m_flags |= M_MCAST;
960 im6o.im6o_multicast_ifp = ifp;
961 im6o.im6o_multicast_hlim = 255;
962 im6o.im6o_multicast_loop = 0;
963 }
964
965 icmp6len = sizeof(*nd_na);
966 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
967 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
968
969 /* fill neighbor advertisement packet */
970 ip6 = mtod(m, struct ip6_hdr *);
971 ip6->ip6_flow = 0;
972 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
973 ip6->ip6_vfc |= IPV6_VERSION;
974 ip6->ip6_nxt = IPPROTO_ICMPV6;
975 ip6->ip6_hlim = 255;
976 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
977 /* reply to DAD */
978 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
979 daddr6.s6_addr16[1] = 0;
980 daddr6.s6_addr32[1] = 0;
981 daddr6.s6_addr32[2] = 0;
982 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
983 if (in6_setscope(&daddr6, ifp, NULL))
984 goto bad;
985
986 flags &= ~ND_NA_FLAG_SOLICITED;
987 }
988 ip6->ip6_dst = daddr6;
989
990 /*
991 * Select a source whose scope is the same as that of the dest.
992 */
993 in6_splitscope(&daddr6, &dst6, &scopeid);
994 error = in6_selectsrc_addr(fibnum, &dst6,
995 scopeid, ifp, &src6, NULL);
996 if (error) {
997 char ip6buf[INET6_ADDRSTRLEN];
998 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
999 "determined: dst=%s, error=%d\n",
1000 ip6_sprintf(ip6buf, &daddr6), error));
1001 goto bad;
1002 }
1003 ip6->ip6_src = src6;
1004 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1005 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1006 nd_na->nd_na_code = 0;
1007 nd_na->nd_na_target = *taddr6;
1008 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1009
1010 /*
1011 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1012 * see nd6_ns_input() for details.
1013 * Basically, if NS packet is sent to unicast/anycast addr,
1014 * target lladdr option SHOULD NOT be included.
1015 */
1016 if (tlladdr) {
1017 /*
1018 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1019 * lladdr in sdl0. If we are not proxying (sending NA for
1020 * my address) use lladdr configured for the interface.
1021 */
1022 if (sdl0 == NULL) {
1023 if (ifp->if_carp)
1024 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1025 if (mac == NULL)
1026 mac = nd6_ifptomac(ifp);
1027 } else if (sdl0->sa_family == AF_LINK) {
1028 struct sockaddr_dl *sdl;
1029 sdl = (struct sockaddr_dl *)sdl0;
1030 if (sdl->sdl_alen == ifp->if_addrlen)
1031 mac = LLADDR(sdl);
1032 }
1033 }
1034 if (tlladdr && mac) {
1035 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1036 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1037
1038 /* roundup to 8 bytes alignment! */
1039 optlen = (optlen + 7) & ~7;
1040
1041 m->m_pkthdr.len += optlen;
1042 m->m_len += optlen;
1043 icmp6len += optlen;
1044 bzero((caddr_t)nd_opt, optlen);
1045 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1046 nd_opt->nd_opt_len = optlen >> 3;
1047 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1048 } else
1049 flags &= ~ND_NA_FLAG_OVERRIDE;
1050
1051 ip6->ip6_plen = htons((u_short)icmp6len);
1052 nd_na->nd_na_flags_reserved = flags;
1053 nd_na->nd_na_cksum = 0;
1054 nd_na->nd_na_cksum =
1055 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1056
1057 if (send_sendso_input_hook != NULL) {
1058 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1059 sizeof(unsigned short), M_NOWAIT);
1060 if (mtag == NULL)
1061 goto bad;
1062 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1063 m_tag_prepend(m, mtag);
1064 }
1065
1066 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1067 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1068 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1069 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1070
1071 return;
1072
1073 bad:
1074 m_freem(m);
1075 }
1076
1077 #ifndef BURN_BRIDGES
1078 void
1079 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1080 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1081 struct sockaddr *sdl0)
1082 {
1083
1084 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1085 RT_DEFAULT_FIB);
1086 }
1087 #endif
1088
1089 caddr_t
1090 nd6_ifptomac(struct ifnet *ifp)
1091 {
1092 switch (ifp->if_type) {
1093 case IFT_ETHER:
1094 case IFT_IEEE1394:
1095 case IFT_L2VLAN:
1096 case IFT_INFINIBAND:
1097 case IFT_BRIDGE:
1098 return IF_LLADDR(ifp);
1099 default:
1100 return NULL;
1101 }
1102 }
1103
1104 struct dadq {
1105 TAILQ_ENTRY(dadq) dad_list;
1106 struct ifaddr *dad_ifa;
1107 int dad_count; /* max NS to send */
1108 int dad_ns_tcount; /* # of trials to send NS */
1109 int dad_ns_ocount; /* NS sent so far */
1110 int dad_ns_icount;
1111 int dad_na_icount;
1112 int dad_ns_lcount; /* looped back NS */
1113 int dad_loopbackprobe; /* probing state for loopback detection */
1114 struct callout dad_timer_ch;
1115 struct vnet *dad_vnet;
1116 u_int dad_refcnt;
1117 #define ND_OPT_NONCE_LEN32 \
1118 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1119 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1120 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */
1121 };
1122
1123 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq);
1124 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock);
1125 #define V_dadq VNET(dadq)
1126 #define V_dad_rwlock VNET(dad_rwlock)
1127
1128 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock)
1129 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock)
1130 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock)
1131 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock)
1132
1133 static void
1134 nd6_dad_add(struct dadq *dp)
1135 {
1136
1137 DADQ_WLOCK();
1138 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1139 dp->dad_ondadq = true;
1140 DADQ_WUNLOCK();
1141 }
1142
1143 static void
1144 nd6_dad_del(struct dadq *dp)
1145 {
1146
1147 DADQ_WLOCK();
1148 if (dp->dad_ondadq) {
1149 /*
1150 * Remove dp from the dadq and release the dadq's
1151 * reference.
1152 */
1153 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1154 dp->dad_ondadq = false;
1155 DADQ_WUNLOCK();
1156 nd6_dad_rele(dp);
1157 } else
1158 DADQ_WUNLOCK();
1159 }
1160
1161 static struct dadq *
1162 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
1163 {
1164 struct dadq *dp;
1165
1166 DADQ_RLOCK();
1167 TAILQ_FOREACH(dp, &V_dadq, dad_list) {
1168 if (dp->dad_ifa != ifa)
1169 continue;
1170 /*
1171 * Skip if the nonce matches the received one.
1172 * +2 in the length is required because of type and
1173 * length fields are included in a header.
1174 */
1175 if (n != NULL &&
1176 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
1177 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
1178 ND_OPT_NONCE_LEN) == 0) {
1179 dp->dad_ns_lcount++;
1180 continue;
1181 }
1182 refcount_acquire(&dp->dad_refcnt);
1183 break;
1184 }
1185 DADQ_RUNLOCK();
1186
1187 return (dp);
1188 }
1189
1190 static void
1191 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns)
1192 {
1193
1194 if (send_ns != 0)
1195 nd6_dad_ns_output(dp);
1196 callout_reset(&dp->dad_timer_ch, ticks,
1197 (void (*)(void *))nd6_dad_timer, (void *)dp);
1198 }
1199
1200 static void
1201 nd6_dad_stoptimer(struct dadq *dp)
1202 {
1203
1204 callout_drain(&dp->dad_timer_ch);
1205 }
1206
1207 static void
1208 nd6_dad_rele(struct dadq *dp)
1209 {
1210
1211 if (refcount_release(&dp->dad_refcnt)) {
1212 ifa_free(dp->dad_ifa);
1213 free(dp, M_IP6NDP);
1214 }
1215 }
1216
1217 void
1218 nd6_dad_init(void)
1219 {
1220
1221 rw_init(&V_dad_rwlock, "nd6 DAD queue");
1222 TAILQ_INIT(&V_dadq);
1223 }
1224
1225 /*
1226 * Start Duplicate Address Detection (DAD) for specified interface address.
1227 */
1228 void
1229 nd6_dad_start(struct ifaddr *ifa, int delay)
1230 {
1231 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1232 struct dadq *dp;
1233 char ip6buf[INET6_ADDRSTRLEN];
1234
1235 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0,
1236 ("starting DAD on non-tentative address %p", ifa));
1237
1238 /*
1239 * If we don't need DAD, don't do it.
1240 * There are several cases:
1241 * - DAD is disabled globally or on the interface
1242 * - the interface address is anycast
1243 */
1244 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 ||
1245 V_ip6_dad_count == 0 ||
1246 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) {
1247 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1248 return;
1249 }
1250 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 ||
1251 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1252 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0)
1253 return;
1254
1255 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1256 /*
1257 * DAD is already in progress. Let the existing entry
1258 * finish it.
1259 */
1260 nd6_dad_rele(dp);
1261 return;
1262 }
1263
1264 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1265 if (dp == NULL) {
1266 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1267 "%s(%s)\n",
1268 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1269 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1270 return;
1271 }
1272 callout_init(&dp->dad_timer_ch, 0);
1273 #ifdef VIMAGE
1274 dp->dad_vnet = curvnet;
1275 #endif
1276 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1277 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1278
1279 /*
1280 * Send NS packet for DAD, ip6_dad_count times.
1281 * Note that we must delay the first transmission, if this is the
1282 * first packet to be sent from the interface after interface
1283 * (re)initialization.
1284 */
1285 dp->dad_ifa = ifa;
1286 ifa_ref(dp->dad_ifa);
1287 dp->dad_count = V_ip6_dad_count;
1288 dp->dad_ns_icount = dp->dad_na_icount = 0;
1289 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1290 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1291
1292 /* Add this to the dadq and add a reference for the dadq. */
1293 refcount_init(&dp->dad_refcnt, 1);
1294 nd6_dad_add(dp);
1295 nd6_dad_starttimer(dp, delay, 0);
1296 }
1297
1298 /*
1299 * terminate DAD unconditionally. used for address removals.
1300 */
1301 void
1302 nd6_dad_stop(struct ifaddr *ifa)
1303 {
1304 struct dadq *dp;
1305
1306 dp = nd6_dad_find(ifa, NULL);
1307 if (!dp) {
1308 /* DAD wasn't started yet */
1309 return;
1310 }
1311
1312 nd6_dad_stoptimer(dp);
1313 nd6_dad_del(dp);
1314
1315 /* Release this function's reference, acquired by nd6_dad_find(). */
1316 nd6_dad_rele(dp);
1317 }
1318
1319 static void
1320 nd6_dad_timer(struct dadq *dp)
1321 {
1322 CURVNET_SET(dp->dad_vnet);
1323 struct ifaddr *ifa = dp->dad_ifa;
1324 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1325 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1326 char ip6buf[INET6_ADDRSTRLEN];
1327
1328 KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
1329
1330 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
1331 /* Do not need DAD for ifdisabled interface. */
1332 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1333 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1334 goto err;
1335 }
1336 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1337 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1338 "%s(%s)\n",
1339 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1340 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1341 goto err;
1342 }
1343 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1344 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1345 "%s(%s)\n",
1346 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1347 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1348 goto err;
1349 }
1350
1351 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1352 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1353 (((ifp->if_flags & IFF_UP) == 0) ||
1354 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1355 nd6log((LOG_INFO, "%s: could not run DAD "
1356 "because the interface was down or not running.\n",
1357 if_name(ifa->ifa_ifp)));
1358 goto err;
1359 }
1360
1361 /* Need more checks? */
1362 if (dp->dad_ns_ocount < dp->dad_count) {
1363 /*
1364 * We have more NS to go. Send NS packet for DAD.
1365 */
1366 nd6_dad_starttimer(dp,
1367 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1);
1368 goto done;
1369 } else {
1370 /*
1371 * We have transmitted sufficient number of DAD packets.
1372 * See what we've got.
1373 */
1374 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0)
1375 /* We've seen NS or NA, means DAD has failed. */
1376 nd6_dad_duplicated(ifa, dp);
1377 else if (V_dad_enhanced != 0 &&
1378 dp->dad_ns_lcount > 0 &&
1379 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1380 /*
1381 * Sec. 4.1 in RFC 7527 requires transmission of
1382 * additional probes until the loopback condition
1383 * becomes clear when a looped back probe is detected.
1384 */
1385 log(LOG_ERR, "%s: a looped back NS message is "
1386 "detected during DAD for %s. "
1387 "Another DAD probes are being sent.\n",
1388 if_name(ifa->ifa_ifp),
1389 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1390 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1391 /*
1392 * Send an NS immediately and increase dad_count by
1393 * V_nd6_mmaxtries - 1.
1394 */
1395 dp->dad_count =
1396 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1397 nd6_dad_starttimer(dp,
1398 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000,
1399 1);
1400 goto done;
1401 } else {
1402 /*
1403 * We are done with DAD. No NA came, no NS came.
1404 * No duplicate address found. Check IFDISABLED flag
1405 * again in case that it is changed between the
1406 * beginning of this function and here.
1407 */
1408 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
1409 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1410
1411 nd6log((LOG_DEBUG,
1412 "%s: DAD complete for %s - no duplicates found\n",
1413 if_name(ifa->ifa_ifp),
1414 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1415 if (dp->dad_ns_lcount > 0)
1416 log(LOG_ERR, "%s: DAD completed while "
1417 "a looped back NS message is detected "
1418 "during DAD for %s.\n",
1419 if_name(ifa->ifa_ifp),
1420 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1421 }
1422 }
1423 err:
1424 nd6_dad_del(dp);
1425 done:
1426 CURVNET_RESTORE();
1427 }
1428
1429 static void
1430 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1431 {
1432 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1433 struct ifnet *ifp;
1434 char ip6buf[INET6_ADDRSTRLEN];
1435
1436 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1437 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1438 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1439 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1440 dp->dad_na_icount);
1441
1442 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1443 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1444
1445 ifp = ifa->ifa_ifp;
1446 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1447 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1448 log(LOG_ERR, "%s: manual intervention required\n",
1449 if_name(ifp));
1450
1451 /*
1452 * If the address is a link-local address formed from an interface
1453 * identifier based on the hardware address which is supposed to be
1454 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1455 * operation on the interface SHOULD be disabled.
1456 * [RFC 4862, Section 5.4.5]
1457 */
1458 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1459 struct in6_addr in6;
1460
1461 /*
1462 * To avoid over-reaction, we only apply this logic when we are
1463 * very sure that hardware addresses are supposed to be unique.
1464 */
1465 switch (ifp->if_type) {
1466 case IFT_ETHER:
1467 case IFT_ATM:
1468 case IFT_IEEE1394:
1469 case IFT_INFINIBAND:
1470 in6 = ia->ia_addr.sin6_addr;
1471 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1472 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1473 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1474 log(LOG_ERR, "%s: possible hardware address "
1475 "duplication detected, disable IPv6\n",
1476 if_name(ifp));
1477 }
1478 break;
1479 }
1480 }
1481 }
1482
1483 static void
1484 nd6_dad_ns_output(struct dadq *dp)
1485 {
1486 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1487 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1488 int i;
1489
1490 dp->dad_ns_tcount++;
1491 if ((ifp->if_flags & IFF_UP) == 0) {
1492 return;
1493 }
1494 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1495 return;
1496 }
1497
1498 dp->dad_ns_ocount++;
1499 if (V_dad_enhanced != 0) {
1500 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1501 dp->dad_nonce[i] = arc4random();
1502 /*
1503 * XXXHRS: Note that in the case that
1504 * DupAddrDetectTransmits > 1, multiple NS messages with
1505 * different nonces can be looped back in an unexpected
1506 * order. The current implementation recognizes only
1507 * the latest nonce on the sender side. Practically it
1508 * should work well in almost all cases.
1509 */
1510 }
1511 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1512 (uint8_t *)&dp->dad_nonce[0]);
1513 }
1514
1515 static void
1516 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1517 {
1518 struct dadq *dp;
1519
1520 if (ifa == NULL)
1521 panic("ifa == NULL in nd6_dad_ns_input");
1522
1523 /* Ignore Nonce option when Enhanced DAD is disabled. */
1524 if (V_dad_enhanced == 0)
1525 ndopt_nonce = NULL;
1526 dp = nd6_dad_find(ifa, ndopt_nonce);
1527 if (dp == NULL)
1528 return;
1529
1530 dp->dad_ns_icount++;
1531 nd6_dad_rele(dp);
1532 }
1533
1534 static void
1535 nd6_dad_na_input(struct ifaddr *ifa)
1536 {
1537 struct dadq *dp;
1538
1539 if (ifa == NULL)
1540 panic("ifa == NULL in nd6_dad_na_input");
1541
1542 dp = nd6_dad_find(ifa, NULL);
1543 if (dp != NULL) {
1544 dp->dad_na_icount++;
1545 nd6_dad_rele(dp);
1546 }
1547 }
Cache object: c43b07927624c744fb87a880ac8613c0
|