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("$FreeBSD$");
36
37 #include "opt_inet.h"
38 #include "opt_inet6.h"
39 #include "opt_ipsec.h"
40
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/eventhandler.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 #include <net/vnet.h>
66
67 #include <netinet/in.h>
68 #include <netinet/in_var.h>
69 #include <net/if_llatbl.h>
70 #include <netinet6/in6_var.h>
71 #include <netinet6/in6_ifattach.h>
72 #include <netinet/ip6.h>
73 #include <netinet6/ip6_var.h>
74 #include <netinet6/scope6_var.h>
75 #include <netinet6/nd6.h>
76 #include <netinet/icmp6.h>
77 #include <netinet/ip_carp.h>
78 #include <netinet6/send.h>
79
80 #define SDL(s) ((struct sockaddr_dl *)s)
81
82 struct dadq;
83 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *);
84 static void nd6_dad_add(struct dadq *dp);
85 static void nd6_dad_del(struct dadq *dp);
86 static void nd6_dad_rele(struct dadq *);
87 static void nd6_dad_starttimer(struct dadq *, int, int);
88 static void nd6_dad_stoptimer(struct dadq *);
89 static void nd6_dad_timer(struct dadq *);
90 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *);
91 static void nd6_dad_ns_output(struct dadq *);
92 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *);
93 static void nd6_dad_na_input(struct ifaddr *);
94 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
95 const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
96 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *,
97 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int);
98
99 VNET_DEFINE_STATIC(int, dad_enhanced) = 1;
100 #define V_dad_enhanced VNET(dad_enhanced)
101
102 SYSCTL_DECL(_net_inet6_ip6);
103 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
104 &VNET_NAME(dad_enhanced), 0,
105 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
106
107 VNET_DEFINE_STATIC(int, dad_maxtry) = 15; /* max # of *tries* to
108 transmit DAD packet */
109 #define V_dad_maxtry VNET(dad_maxtry)
110
111 /*
112 * Input a Neighbor Solicitation Message.
113 *
114 * Based on RFC 2461
115 * Based on RFC 2462 (duplicate address detection)
116 */
117 void
118 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
119 {
120 struct ifnet *ifp;
121 struct ip6_hdr *ip6;
122 struct nd_neighbor_solicit *nd_ns;
123 struct in6_addr daddr6, myaddr6, saddr6, taddr6;
124 struct ifaddr *ifa;
125 struct sockaddr_dl proxydl;
126 union nd_opts ndopts;
127 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
128 char *lladdr;
129 int anycast, lladdrlen, proxy, rflag, tentative, tlladdr;
130
131 ifa = NULL;
132
133 /* RFC 6980: Nodes MUST silently ignore fragments */
134 if(m->m_flags & M_FRAGMENTED)
135 goto freeit;
136
137 ifp = m->m_pkthdr.rcvif;
138 ip6 = mtod(m, struct ip6_hdr *);
139 if (__predict_false(ip6->ip6_hlim != 255)) {
140 ICMP6STAT_INC(icp6s_invlhlim);
141 nd6log((LOG_ERR,
142 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
143 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
144 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
145 goto bads;
146 }
147
148 if (m->m_len < off + icmp6len) {
149 m = m_pullup(m, off + icmp6len);
150 if (m == NULL) {
151 IP6STAT_INC(ip6s_exthdrtoolong);
152 return;
153 }
154 }
155 ip6 = mtod(m, struct ip6_hdr *);
156 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
157
158 saddr6 = ip6->ip6_src;
159 daddr6 = ip6->ip6_dst;
160 taddr6 = nd_ns->nd_ns_target;
161 if (in6_setscope(&taddr6, ifp, NULL) != 0)
162 goto bad;
163
164 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
165 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
166 rflag = 0;
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 lladdr = NULL;
216 lladdrlen = 0;
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 proxy = 0;
257 if (ifa == NULL) {
258 struct sockaddr_dl rt_gateway;
259 struct rt_addrinfo info;
260 struct sockaddr_in6 dst6;
261
262 bzero(&dst6, sizeof(dst6));
263 dst6.sin6_len = sizeof(struct sockaddr_in6);
264 dst6.sin6_family = AF_INET6;
265 dst6.sin6_addr = taddr6;
266
267 bzero(&rt_gateway, sizeof(rt_gateway));
268 rt_gateway.sdl_len = sizeof(rt_gateway);
269 bzero(&info, sizeof(info));
270 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
271
272 if (rib_lookup_info(ifp->if_fib, (struct sockaddr *)&dst6,
273 0, 0, &info) == 0) {
274 if ((info.rti_flags & RTF_ANNOUNCE) != 0 &&
275 rt_gateway.sdl_family == AF_LINK) {
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 bads:
383 ICMP6STAT_INC(icp6s_badns);
384 if (ifa != NULL)
385 ifa_free(ifa);
386 m_freem(m);
387 }
388
389 /*
390 * Output a Neighbor Solicitation Message. Caller specifies:
391 * - ICMP6 header source IP6 address
392 * - ND6 header target IP6 address
393 * - ND6 header source datalink address
394 *
395 * Based on RFC 2461
396 * Based on RFC 2462 (duplicate address detection)
397 *
398 * ln - for source address determination
399 * nonce - If non-NULL, NS is used for duplicate address detection and
400 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
401 */
402 static void
403 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
404 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
405 uint8_t *nonce, u_int fibnum)
406 {
407 struct mbuf *m;
408 struct m_tag *mtag;
409 struct ip6_hdr *ip6;
410 struct nd_neighbor_solicit *nd_ns;
411 struct ip6_moptions im6o;
412 int icmp6len;
413 int maxlen;
414 caddr_t mac;
415
416 if (IN6_IS_ADDR_MULTICAST(taddr6))
417 return;
418
419 /* estimate the size of message */
420 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
421 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
422 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
423 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
424 __func__, max_linkhdr, maxlen, MCLBYTES));
425
426 if (max_linkhdr + maxlen > MHLEN)
427 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
428 else
429 m = m_gethdr(M_NOWAIT, MT_DATA);
430 if (m == NULL)
431 return;
432 M_SETFIB(m, fibnum);
433
434 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
435 m->m_flags |= M_MCAST;
436 im6o.im6o_multicast_ifp = ifp;
437 im6o.im6o_multicast_hlim = 255;
438 im6o.im6o_multicast_loop = 0;
439 }
440
441 icmp6len = sizeof(*nd_ns);
442 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
443 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
444
445 /* fill neighbor solicitation packet */
446 ip6 = mtod(m, struct ip6_hdr *);
447 ip6->ip6_flow = 0;
448 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
449 ip6->ip6_vfc |= IPV6_VERSION;
450 /* ip6->ip6_plen will be set later */
451 ip6->ip6_nxt = IPPROTO_ICMPV6;
452 ip6->ip6_hlim = 255;
453 if (daddr6)
454 ip6->ip6_dst = *daddr6;
455 else {
456 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
457 ip6->ip6_dst.s6_addr16[1] = 0;
458 ip6->ip6_dst.s6_addr32[1] = 0;
459 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
460 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
461 ip6->ip6_dst.s6_addr8[12] = 0xff;
462 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
463 goto bad;
464 }
465 if (nonce == NULL) {
466 struct ifaddr *ifa = NULL;
467
468 /*
469 * RFC2461 7.2.2:
470 * "If the source address of the packet prompting the
471 * solicitation is the same as one of the addresses assigned
472 * to the outgoing interface, that address SHOULD be placed
473 * in the IP Source Address of the outgoing solicitation.
474 * Otherwise, any one of the addresses assigned to the
475 * interface should be used."
476 *
477 * We use the source address for the prompting packet
478 * (saddr6), if saddr6 belongs to the outgoing interface.
479 * Otherwise, we perform the source address selection as usual.
480 */
481
482 if (saddr6 != NULL)
483 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
484 if (ifa != NULL) {
485 /* ip6_src set already. */
486 ip6->ip6_src = *saddr6;
487 ifa_free(ifa);
488 } else {
489 int error;
490 struct in6_addr dst6, src6;
491 uint32_t scopeid;
492
493 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
494 error = in6_selectsrc_addr(fibnum, &dst6,
495 scopeid, ifp, &src6, NULL);
496 if (error) {
497 char ip6buf[INET6_ADDRSTRLEN];
498 nd6log((LOG_DEBUG, "%s: source can't be "
499 "determined: dst=%s, error=%d\n", __func__,
500 ip6_sprintf(ip6buf, &dst6),
501 error));
502 goto bad;
503 }
504 ip6->ip6_src = src6;
505 }
506 } else {
507 /*
508 * Source address for DAD packet must always be IPv6
509 * unspecified address. (0::0)
510 * We actually don't have to 0-clear the address (we did it
511 * above), but we do so here explicitly to make the intention
512 * clearer.
513 */
514 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
515 }
516 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
517 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
518 nd_ns->nd_ns_code = 0;
519 nd_ns->nd_ns_reserved = 0;
520 nd_ns->nd_ns_target = *taddr6;
521 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
522
523 /*
524 * Add source link-layer address option.
525 *
526 * spec implementation
527 * --- ---
528 * DAD packet MUST NOT do not add the option
529 * there's no link layer address:
530 * impossible do not add the option
531 * there's link layer address:
532 * Multicast NS MUST add one add the option
533 * Unicast NS SHOULD add one add the option
534 */
535 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) {
536 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
537 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
538 /* 8 byte alignments... */
539 optlen = (optlen + 7) & ~7;
540
541 m->m_pkthdr.len += optlen;
542 m->m_len += optlen;
543 icmp6len += optlen;
544 bzero((caddr_t)nd_opt, optlen);
545 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
546 nd_opt->nd_opt_len = optlen >> 3;
547 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
548 }
549 /*
550 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
551 * This behavior is documented as Enhanced Duplicate Address
552 * Detection in RFC 7527.
553 * net.inet6.ip6.dad_enhanced=0 disables this.
554 */
555 if (V_dad_enhanced != 0 && nonce != NULL) {
556 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
557 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
558 /* 8-byte alignment is required. */
559 optlen = (optlen + 7) & ~7;
560
561 m->m_pkthdr.len += optlen;
562 m->m_len += optlen;
563 icmp6len += optlen;
564 bzero((caddr_t)nd_opt, optlen);
565 nd_opt->nd_opt_type = ND_OPT_NONCE;
566 nd_opt->nd_opt_len = optlen >> 3;
567 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
568 }
569 ip6->ip6_plen = htons((u_short)icmp6len);
570 nd_ns->nd_ns_cksum = 0;
571 nd_ns->nd_ns_cksum =
572 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
573
574 if (send_sendso_input_hook != NULL) {
575 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
576 sizeof(unsigned short), M_NOWAIT);
577 if (mtag == NULL)
578 goto bad;
579 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
580 m_tag_prepend(m, mtag);
581 }
582
583 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
584 &im6o, NULL, NULL);
585 icmp6_ifstat_inc(ifp, ifs6_out_msg);
586 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
587 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
588
589 return;
590
591 bad:
592 m_freem(m);
593 }
594
595 #ifndef BURN_BRIDGES
596 void
597 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
598 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
599 {
600
601 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
602 }
603 #endif
604 /*
605 * Neighbor advertisement input handling.
606 *
607 * Based on RFC 2461
608 * Based on RFC 2462 (duplicate address detection)
609 *
610 * the following items are not implemented yet:
611 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
612 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
613 */
614 void
615 nd6_na_input(struct mbuf *m, int off, int icmp6len)
616 {
617 struct ifnet *ifp;
618 struct ip6_hdr *ip6;
619 struct ifaddr *ifa;
620 struct llentry *ln;
621 struct mbuf *chain;
622 struct nd_neighbor_advert *nd_na;
623 struct in6_addr daddr6, taddr6;
624 struct sockaddr_in6 sin6;
625 union nd_opts ndopts;
626 u_char linkhdr[LLE_MAX_LINKHDR];
627 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
628 char *lladdr;
629 size_t linkhdrsize;
630 int flags, is_override, is_router, is_solicited;
631 int lladdr_off, lladdrlen, checklink;
632
633 NET_EPOCH_ASSERT();
634
635 chain = NULL;
636 ln = NULL;
637 checklink = 0;
638
639 /* RFC 6980: Nodes MUST silently ignore fragments */
640 if(m->m_flags & M_FRAGMENTED)
641 goto freeit;
642
643 ifp = m->m_pkthdr.rcvif;
644 ip6 = mtod(m, struct ip6_hdr *);
645 if (__predict_false(ip6->ip6_hlim != 255)) {
646 ICMP6STAT_INC(icp6s_invlhlim);
647 nd6log((LOG_ERR,
648 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
649 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
650 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
651 goto bad;
652 }
653
654 if (m->m_len < off + icmp6len) {
655 m = m_pullup(m, off + icmp6len);
656 if (m == NULL) {
657 IP6STAT_INC(ip6s_exthdrtoolong);
658 return;
659 }
660 }
661 ip6 = mtod(m, struct ip6_hdr *);
662 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
663
664 flags = nd_na->nd_na_flags_reserved;
665 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
666 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
667 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
668
669 taddr6 = nd_na->nd_na_target;
670 if (in6_setscope(&taddr6, ifp, NULL))
671 goto bad; /* XXX: impossible */
672
673 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
674 nd6log((LOG_ERR,
675 "nd6_na_input: invalid target address %s\n",
676 ip6_sprintf(ip6bufs, &taddr6)));
677 goto bad;
678 }
679
680 daddr6 = ip6->ip6_dst;
681 if (IN6_IS_ADDR_MULTICAST(&daddr6))
682 if (is_solicited) {
683 nd6log((LOG_ERR,
684 "nd6_na_input: a solicited adv is multicasted\n"));
685 goto bad;
686 }
687
688 icmp6len -= sizeof(*nd_na);
689 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
690 if (nd6_options(&ndopts) < 0) {
691 nd6log((LOG_INFO,
692 "nd6_na_input: invalid ND option, ignored\n"));
693 /* nd6_options have incremented stats */
694 goto freeit;
695 }
696
697 lladdr = NULL;
698 lladdrlen = 0;
699 if (ndopts.nd_opts_tgt_lladdr) {
700 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
701 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
702 }
703
704 /*
705 * This effectively disables the DAD check on a non-master CARP
706 * address.
707 */
708 if (ifp->if_carp)
709 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
710 else
711 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
712
713 /*
714 * Target address matches one of my interface address.
715 *
716 * If my address is tentative, this means that there's somebody
717 * already using the same address as mine. This indicates DAD failure.
718 * This is defined in RFC 2462.
719 *
720 * Otherwise, process as defined in RFC 2461.
721 */
722 if (ifa
723 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
724 nd6_dad_na_input(ifa);
725 ifa_free(ifa);
726 goto freeit;
727 }
728
729 /* Just for safety, maybe unnecessary. */
730 if (ifa) {
731 ifa_free(ifa);
732 log(LOG_ERR,
733 "nd6_na_input: duplicate IP6 address %s\n",
734 ip6_sprintf(ip6bufs, &taddr6));
735 goto freeit;
736 }
737
738 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
739 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
740 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
741 ifp->if_addrlen, lladdrlen - 2));
742 goto bad;
743 }
744
745 /*
746 * If no neighbor cache entry is found, NA SHOULD silently be
747 * discarded.
748 */
749 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
750 if (ln == NULL) {
751 goto freeit;
752 }
753
754 /*
755 * Do not try to override static entry.
756 */
757 if (ln->la_flags & LLE_STATIC)
758 goto freeit;
759
760 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
761 /*
762 * If the link-layer has address, and no lladdr option came,
763 * discard the packet.
764 */
765 if (ifp->if_addrlen && lladdr == NULL) {
766 goto freeit;
767 }
768
769 /*
770 * Record link-layer address, and update the state.
771 */
772 linkhdrsize = sizeof(linkhdr);
773 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
774 linkhdr, &linkhdrsize, &lladdr_off) != 0)
775 return;
776
777 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
778 lladdr_off) == 0) {
779 ln = NULL;
780 goto freeit;
781 }
782 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
783 if (is_solicited)
784 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
785 else
786 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
787 if ((ln->ln_router = is_router) != 0) {
788 /*
789 * This means a router's state has changed from
790 * non-reachable to probably reachable, and might
791 * affect the status of associated prefixes..
792 */
793 checklink = 1;
794 }
795 } else {
796 int llchange;
797
798 /*
799 * Check if the link-layer address has changed or not.
800 */
801 if (lladdr == NULL)
802 llchange = 0;
803 else {
804 if (ln->la_flags & LLE_VALID) {
805 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
806 llchange = 1;
807 else
808 llchange = 0;
809 } else
810 llchange = 1;
811 }
812
813 /*
814 * This is VERY complex. Look at it with care.
815 *
816 * override solicit lladdr llchange action
817 * (L: record lladdr)
818 *
819 * 0 0 n -- (2c)
820 * 0 0 y n (2b) L
821 * 0 0 y y (1) REACHABLE->STALE
822 * 0 1 n -- (2c) *->REACHABLE
823 * 0 1 y n (2b) L *->REACHABLE
824 * 0 1 y y (1) REACHABLE->STALE
825 * 1 0 n -- (2a)
826 * 1 0 y n (2a) L
827 * 1 0 y y (2a) L *->STALE
828 * 1 1 n -- (2a) *->REACHABLE
829 * 1 1 y n (2a) L *->REACHABLE
830 * 1 1 y y (2a) L *->REACHABLE
831 */
832 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
833 /*
834 * If state is REACHABLE, make it STALE.
835 * no other updates should be done.
836 */
837 if (ln->ln_state == ND6_LLINFO_REACHABLE)
838 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
839 goto freeit;
840 } else if (is_override /* (2a) */
841 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
842 || lladdr == NULL) { /* (2c) */
843 /*
844 * Update link-local address, if any.
845 */
846 if (lladdr != NULL) {
847 linkhdrsize = sizeof(linkhdr);
848 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
849 linkhdr, &linkhdrsize, &lladdr_off) != 0)
850 goto freeit;
851 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
852 linkhdrsize, lladdr_off) == 0) {
853 ln = NULL;
854 goto freeit;
855 }
856 EVENTHANDLER_INVOKE(lle_event, ln,
857 LLENTRY_RESOLVED);
858 }
859
860 /*
861 * If solicited, make the state REACHABLE.
862 * If not solicited and the link-layer address was
863 * changed, make it STALE.
864 */
865 if (is_solicited)
866 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
867 else {
868 if (lladdr != NULL && llchange)
869 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
870 }
871 }
872
873 if (ln->ln_router && !is_router) {
874 /*
875 * The peer dropped the router flag.
876 * Remove the sender from the Default Router List and
877 * update the Destination Cache entries.
878 */
879 struct ifnet *nd6_ifp;
880
881 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
882 if (!defrouter_remove(&ln->r_l3addr.addr6, nd6_ifp) &&
883 (ND_IFINFO(nd6_ifp)->flags &
884 ND6_IFF_ACCEPT_RTADV) != 0)
885 /*
886 * Even if the neighbor is not in the default
887 * router list, the neighbor may be used as a
888 * next hop for some destinations (e.g. redirect
889 * case). So we must call rt6_flush explicitly.
890 */
891 rt6_flush(&ip6->ip6_src, ifp);
892 }
893 ln->ln_router = is_router;
894 }
895 /* XXX - QL
896 * Does this matter?
897 * rt->rt_flags &= ~RTF_REJECT;
898 */
899 ln->la_asked = 0;
900 if (ln->la_hold != NULL) {
901 memset(&sin6, 0, sizeof(sin6));
902 nd6_grab_holdchain(ln, &chain, &sin6);
903 }
904 freeit:
905 if (ln != NULL)
906 LLE_WUNLOCK(ln);
907
908 if (chain != NULL)
909 nd6_flush_holdchain(ifp, chain, &sin6);
910
911 if (checklink)
912 pfxlist_onlink_check();
913
914 m_freem(m);
915 return;
916
917 bad:
918 if (ln != NULL)
919 LLE_WUNLOCK(ln);
920
921 ICMP6STAT_INC(icp6s_badna);
922 m_freem(m);
923 }
924
925 /*
926 * Neighbor advertisement output handling.
927 *
928 * Based on RFC 2461
929 *
930 * the following items are not implemented yet:
931 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
932 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
933 *
934 * tlladdr - 1 if include target link-layer address
935 * sdl0 - sockaddr_dl (= proxy NA) or NULL
936 */
937 static void
938 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
939 const struct in6_addr *taddr6, u_long flags, int tlladdr,
940 struct sockaddr *sdl0, u_int fibnum)
941 {
942 struct mbuf *m;
943 struct m_tag *mtag;
944 struct ip6_hdr *ip6;
945 struct nd_neighbor_advert *nd_na;
946 struct ip6_moptions im6o;
947 struct in6_addr daddr6, dst6, src6;
948 uint32_t scopeid;
949
950 int icmp6len, maxlen, error;
951 caddr_t mac = NULL;
952
953 daddr6 = *daddr6_0; /* make a local copy for modification */
954
955 /* estimate the size of message */
956 maxlen = sizeof(*ip6) + sizeof(*nd_na);
957 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
958 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
959 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
960 __func__, max_linkhdr, maxlen, MCLBYTES));
961
962 if (max_linkhdr + maxlen > MHLEN)
963 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
964 else
965 m = m_gethdr(M_NOWAIT, MT_DATA);
966 if (m == NULL)
967 return;
968 M_SETFIB(m, fibnum);
969
970 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
971 m->m_flags |= M_MCAST;
972 im6o.im6o_multicast_ifp = ifp;
973 im6o.im6o_multicast_hlim = 255;
974 im6o.im6o_multicast_loop = 0;
975 }
976
977 icmp6len = sizeof(*nd_na);
978 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
979 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
980
981 /* fill neighbor advertisement packet */
982 ip6 = mtod(m, struct ip6_hdr *);
983 ip6->ip6_flow = 0;
984 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
985 ip6->ip6_vfc |= IPV6_VERSION;
986 ip6->ip6_nxt = IPPROTO_ICMPV6;
987 ip6->ip6_hlim = 255;
988 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
989 /* reply to DAD */
990 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
991 daddr6.s6_addr16[1] = 0;
992 daddr6.s6_addr32[1] = 0;
993 daddr6.s6_addr32[2] = 0;
994 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
995 if (in6_setscope(&daddr6, ifp, NULL))
996 goto bad;
997
998 flags &= ~ND_NA_FLAG_SOLICITED;
999 }
1000 ip6->ip6_dst = daddr6;
1001
1002 /*
1003 * Select a source whose scope is the same as that of the dest.
1004 */
1005 in6_splitscope(&daddr6, &dst6, &scopeid);
1006 error = in6_selectsrc_addr(fibnum, &dst6,
1007 scopeid, ifp, &src6, NULL);
1008 if (error) {
1009 char ip6buf[INET6_ADDRSTRLEN];
1010 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1011 "determined: dst=%s, error=%d\n",
1012 ip6_sprintf(ip6buf, &daddr6), error));
1013 goto bad;
1014 }
1015 ip6->ip6_src = src6;
1016 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1017 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1018 nd_na->nd_na_code = 0;
1019 nd_na->nd_na_target = *taddr6;
1020 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1021
1022 /*
1023 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1024 * see nd6_ns_input() for details.
1025 * Basically, if NS packet is sent to unicast/anycast addr,
1026 * target lladdr option SHOULD NOT be included.
1027 */
1028 if (tlladdr) {
1029 /*
1030 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1031 * lladdr in sdl0. If we are not proxying (sending NA for
1032 * my address) use lladdr configured for the interface.
1033 */
1034 if (sdl0 == NULL) {
1035 if (ifp->if_carp)
1036 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1037 if (mac == NULL)
1038 mac = nd6_ifptomac(ifp);
1039 } else if (sdl0->sa_family == AF_LINK) {
1040 struct sockaddr_dl *sdl;
1041 sdl = (struct sockaddr_dl *)sdl0;
1042 if (sdl->sdl_alen == ifp->if_addrlen)
1043 mac = LLADDR(sdl);
1044 }
1045 }
1046 if (tlladdr && mac) {
1047 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1048 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1049
1050 /* roundup to 8 bytes alignment! */
1051 optlen = (optlen + 7) & ~7;
1052
1053 m->m_pkthdr.len += optlen;
1054 m->m_len += optlen;
1055 icmp6len += optlen;
1056 bzero((caddr_t)nd_opt, optlen);
1057 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1058 nd_opt->nd_opt_len = optlen >> 3;
1059 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1060 } else
1061 flags &= ~ND_NA_FLAG_OVERRIDE;
1062
1063 ip6->ip6_plen = htons((u_short)icmp6len);
1064 nd_na->nd_na_flags_reserved = flags;
1065 nd_na->nd_na_cksum = 0;
1066 nd_na->nd_na_cksum =
1067 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1068
1069 if (send_sendso_input_hook != NULL) {
1070 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1071 sizeof(unsigned short), M_NOWAIT);
1072 if (mtag == NULL)
1073 goto bad;
1074 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1075 m_tag_prepend(m, mtag);
1076 }
1077
1078 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1079 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1080 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1081 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1082
1083 return;
1084
1085 bad:
1086 m_freem(m);
1087 }
1088
1089 #ifndef BURN_BRIDGES
1090 void
1091 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1092 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1093 struct sockaddr *sdl0)
1094 {
1095
1096 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1097 RT_DEFAULT_FIB);
1098 }
1099 #endif
1100
1101 caddr_t
1102 nd6_ifptomac(struct ifnet *ifp)
1103 {
1104 switch (ifp->if_type) {
1105 case IFT_ETHER:
1106 case IFT_IEEE1394:
1107 case IFT_L2VLAN:
1108 case IFT_INFINIBAND:
1109 case IFT_BRIDGE:
1110 return IF_LLADDR(ifp);
1111 default:
1112 return NULL;
1113 }
1114 }
1115
1116 struct dadq {
1117 TAILQ_ENTRY(dadq) dad_list;
1118 struct ifaddr *dad_ifa;
1119 int dad_count; /* max NS to send */
1120 int dad_ns_tcount; /* # of trials to send NS */
1121 int dad_ns_ocount; /* NS sent so far */
1122 int dad_ns_icount;
1123 int dad_na_icount;
1124 int dad_ns_lcount; /* looped back NS */
1125 int dad_loopbackprobe; /* probing state for loopback detection */
1126 struct callout dad_timer_ch;
1127 struct vnet *dad_vnet;
1128 u_int dad_refcnt;
1129 #define ND_OPT_NONCE_LEN32 \
1130 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1131 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1132 bool dad_ondadq; /* on dadq? Protected by DADQ_WLOCK. */
1133 };
1134
1135 VNET_DEFINE_STATIC(TAILQ_HEAD(, dadq), dadq);
1136 VNET_DEFINE_STATIC(struct rwlock, dad_rwlock);
1137 #define V_dadq VNET(dadq)
1138 #define V_dad_rwlock VNET(dad_rwlock)
1139
1140 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock)
1141 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock)
1142 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock)
1143 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock)
1144
1145 static void
1146 nd6_dad_add(struct dadq *dp)
1147 {
1148
1149 DADQ_WLOCK();
1150 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1151 dp->dad_ondadq = true;
1152 DADQ_WUNLOCK();
1153 }
1154
1155 static void
1156 nd6_dad_del(struct dadq *dp)
1157 {
1158
1159 DADQ_WLOCK();
1160 if (dp->dad_ondadq) {
1161 /*
1162 * Remove dp from the dadq and release the dadq's
1163 * reference.
1164 */
1165 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1166 dp->dad_ondadq = false;
1167 DADQ_WUNLOCK();
1168 nd6_dad_rele(dp);
1169 } else
1170 DADQ_WUNLOCK();
1171 }
1172
1173 static struct dadq *
1174 nd6_dad_find(struct ifaddr *ifa, struct nd_opt_nonce *n)
1175 {
1176 struct dadq *dp;
1177
1178 DADQ_RLOCK();
1179 TAILQ_FOREACH(dp, &V_dadq, dad_list) {
1180 if (dp->dad_ifa != ifa)
1181 continue;
1182 /*
1183 * Skip if the nonce matches the received one.
1184 * +2 in the length is required because of type and
1185 * length fields are included in a header.
1186 */
1187 if (n != NULL &&
1188 n->nd_opt_nonce_len == (ND_OPT_NONCE_LEN + 2) / 8 &&
1189 memcmp(&n->nd_opt_nonce[0], &dp->dad_nonce[0],
1190 ND_OPT_NONCE_LEN) == 0) {
1191 dp->dad_ns_lcount++;
1192 continue;
1193 }
1194 refcount_acquire(&dp->dad_refcnt);
1195 break;
1196 }
1197 DADQ_RUNLOCK();
1198
1199 return (dp);
1200 }
1201
1202 static void
1203 nd6_dad_starttimer(struct dadq *dp, int ticks, int send_ns)
1204 {
1205
1206 NET_EPOCH_ASSERT();
1207
1208 if (send_ns != 0)
1209 nd6_dad_ns_output(dp);
1210 callout_reset(&dp->dad_timer_ch, ticks,
1211 (void (*)(void *))nd6_dad_timer, (void *)dp);
1212 }
1213
1214 static void
1215 nd6_dad_stoptimer(struct dadq *dp)
1216 {
1217
1218 callout_drain(&dp->dad_timer_ch);
1219 }
1220
1221 static void
1222 nd6_dad_rele(struct dadq *dp)
1223 {
1224
1225 if (refcount_release(&dp->dad_refcnt)) {
1226 ifa_free(dp->dad_ifa);
1227 free(dp, M_IP6NDP);
1228 }
1229 }
1230
1231 void
1232 nd6_dad_init(void)
1233 {
1234
1235 rw_init(&V_dad_rwlock, "nd6 DAD queue");
1236 TAILQ_INIT(&V_dadq);
1237 }
1238
1239 /*
1240 * Start Duplicate Address Detection (DAD) for specified interface address.
1241 */
1242 void
1243 nd6_dad_start(struct ifaddr *ifa, int delay)
1244 {
1245 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1246 struct dadq *dp;
1247 char ip6buf[INET6_ADDRSTRLEN];
1248 struct epoch_tracker et;
1249
1250 KASSERT((ia->ia6_flags & IN6_IFF_TENTATIVE) != 0,
1251 ("starting DAD on non-tentative address %p", ifa));
1252
1253 /*
1254 * If we don't need DAD, don't do it.
1255 * There are several cases:
1256 * - DAD is disabled globally or on the interface
1257 * - the interface address is anycast
1258 */
1259 if ((ia->ia6_flags & IN6_IFF_ANYCAST) != 0 ||
1260 V_ip6_dad_count == 0 ||
1261 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) != 0) {
1262 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1263 return;
1264 }
1265 if ((ifa->ifa_ifp->if_flags & IFF_UP) == 0 ||
1266 (ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1267 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED) != 0)
1268 return;
1269
1270 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1271 /*
1272 * DAD is already in progress. Let the existing entry
1273 * finish it.
1274 */
1275 nd6_dad_rele(dp);
1276 return;
1277 }
1278
1279 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1280 if (dp == NULL) {
1281 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1282 "%s(%s)\n",
1283 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1284 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1285 return;
1286 }
1287 callout_init(&dp->dad_timer_ch, 0);
1288 #ifdef VIMAGE
1289 dp->dad_vnet = curvnet;
1290 #endif
1291 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1292 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1293
1294 /*
1295 * Send NS packet for DAD, ip6_dad_count times.
1296 * Note that we must delay the first transmission, if this is the
1297 * first packet to be sent from the interface after interface
1298 * (re)initialization.
1299 */
1300 dp->dad_ifa = ifa;
1301 ifa_ref(dp->dad_ifa);
1302 dp->dad_count = V_ip6_dad_count;
1303 dp->dad_ns_icount = dp->dad_na_icount = 0;
1304 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1305 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1306
1307 /* Add this to the dadq and add a reference for the dadq. */
1308 refcount_init(&dp->dad_refcnt, 1);
1309 nd6_dad_add(dp);
1310 NET_EPOCH_ENTER(et);
1311 nd6_dad_starttimer(dp, delay, 0);
1312 NET_EPOCH_EXIT(et);
1313 }
1314
1315 /*
1316 * terminate DAD unconditionally. used for address removals.
1317 */
1318 void
1319 nd6_dad_stop(struct ifaddr *ifa)
1320 {
1321 struct dadq *dp;
1322
1323 dp = nd6_dad_find(ifa, NULL);
1324 if (!dp) {
1325 /* DAD wasn't started yet */
1326 return;
1327 }
1328
1329 nd6_dad_stoptimer(dp);
1330 nd6_dad_del(dp);
1331
1332 /* Release this function's reference, acquired by nd6_dad_find(). */
1333 nd6_dad_rele(dp);
1334 }
1335
1336 static void
1337 nd6_dad_timer(struct dadq *dp)
1338 {
1339 CURVNET_SET(dp->dad_vnet);
1340 struct ifaddr *ifa = dp->dad_ifa;
1341 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1342 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1343 char ip6buf[INET6_ADDRSTRLEN];
1344 struct epoch_tracker et;
1345
1346 KASSERT(ia != NULL, ("DAD entry %p with no address", dp));
1347
1348 NET_EPOCH_ENTER(et);
1349 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
1350 /* Do not need DAD for ifdisabled interface. */
1351 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1352 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1353 goto err;
1354 }
1355 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1356 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1357 "%s(%s)\n",
1358 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1359 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1360 goto err;
1361 }
1362 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1363 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1364 "%s(%s)\n",
1365 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1366 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1367 goto err;
1368 }
1369
1370 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1371 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1372 (((ifp->if_flags & IFF_UP) == 0) ||
1373 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1374 nd6log((LOG_INFO, "%s: could not run DAD "
1375 "because the interface was down or not running.\n",
1376 if_name(ifa->ifa_ifp)));
1377 goto err;
1378 }
1379
1380 /* Need more checks? */
1381 if (dp->dad_ns_ocount < dp->dad_count) {
1382 /*
1383 * We have more NS to go. Send NS packet for DAD.
1384 */
1385 nd6_dad_starttimer(dp,
1386 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1);
1387 goto done;
1388 } else {
1389 /*
1390 * We have transmitted sufficient number of DAD packets.
1391 * See what we've got.
1392 */
1393 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0)
1394 /* We've seen NS or NA, means DAD has failed. */
1395 nd6_dad_duplicated(ifa, dp);
1396 else if (V_dad_enhanced != 0 &&
1397 dp->dad_ns_lcount > 0 &&
1398 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1399 /*
1400 * Sec. 4.1 in RFC 7527 requires transmission of
1401 * additional probes until the loopback condition
1402 * becomes clear when a looped back probe is detected.
1403 */
1404 log(LOG_ERR, "%s: a looped back NS message is "
1405 "detected during DAD for %s. "
1406 "Another DAD probes are being sent.\n",
1407 if_name(ifa->ifa_ifp),
1408 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1409 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1410 /*
1411 * Send an NS immediately and increase dad_count by
1412 * V_nd6_mmaxtries - 1.
1413 */
1414 dp->dad_count =
1415 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1416 nd6_dad_starttimer(dp,
1417 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000,
1418 1);
1419 goto done;
1420 } else {
1421 /*
1422 * We are done with DAD. No NA came, no NS came.
1423 * No duplicate address found. Check IFDISABLED flag
1424 * again in case that it is changed between the
1425 * beginning of this function and here.
1426 */
1427 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
1428 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1429
1430 nd6log((LOG_DEBUG,
1431 "%s: DAD complete for %s - no duplicates found\n",
1432 if_name(ifa->ifa_ifp),
1433 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1434 if (dp->dad_ns_lcount > 0)
1435 log(LOG_ERR, "%s: DAD completed while "
1436 "a looped back NS message is detected "
1437 "during DAD for %s.\n",
1438 if_name(ifa->ifa_ifp),
1439 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1440 }
1441 }
1442 err:
1443 nd6_dad_del(dp);
1444 done:
1445 NET_EPOCH_EXIT(et);
1446 CURVNET_RESTORE();
1447 }
1448
1449 static void
1450 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1451 {
1452 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1453 struct ifnet *ifp;
1454 char ip6buf[INET6_ADDRSTRLEN];
1455
1456 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1457 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1458 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1459 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1460 dp->dad_na_icount);
1461
1462 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1463 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1464
1465 ifp = ifa->ifa_ifp;
1466 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1467 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1468 log(LOG_ERR, "%s: manual intervention required\n",
1469 if_name(ifp));
1470
1471 /*
1472 * If the address is a link-local address formed from an interface
1473 * identifier based on the hardware address which is supposed to be
1474 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1475 * operation on the interface SHOULD be disabled.
1476 * [RFC 4862, Section 5.4.5]
1477 */
1478 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1479 struct in6_addr in6;
1480
1481 /*
1482 * To avoid over-reaction, we only apply this logic when we are
1483 * very sure that hardware addresses are supposed to be unique.
1484 */
1485 switch (ifp->if_type) {
1486 case IFT_ETHER:
1487 case IFT_ATM:
1488 case IFT_IEEE1394:
1489 case IFT_INFINIBAND:
1490 in6 = ia->ia_addr.sin6_addr;
1491 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1492 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1493 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1494 log(LOG_ERR, "%s: possible hardware address "
1495 "duplication detected, disable IPv6\n",
1496 if_name(ifp));
1497 }
1498 break;
1499 }
1500 }
1501 }
1502
1503 static void
1504 nd6_dad_ns_output(struct dadq *dp)
1505 {
1506 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1507 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1508 int i;
1509
1510 dp->dad_ns_tcount++;
1511 if ((ifp->if_flags & IFF_UP) == 0) {
1512 return;
1513 }
1514 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1515 return;
1516 }
1517
1518 dp->dad_ns_ocount++;
1519 if (V_dad_enhanced != 0) {
1520 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1521 dp->dad_nonce[i] = arc4random();
1522 /*
1523 * XXXHRS: Note that in the case that
1524 * DupAddrDetectTransmits > 1, multiple NS messages with
1525 * different nonces can be looped back in an unexpected
1526 * order. The current implementation recognizes only
1527 * the latest nonce on the sender side. Practically it
1528 * should work well in almost all cases.
1529 */
1530 }
1531 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1532 (uint8_t *)&dp->dad_nonce[0]);
1533 }
1534
1535 static void
1536 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1537 {
1538 struct dadq *dp;
1539
1540 if (ifa == NULL)
1541 panic("ifa == NULL in nd6_dad_ns_input");
1542
1543 /* Ignore Nonce option when Enhanced DAD is disabled. */
1544 if (V_dad_enhanced == 0)
1545 ndopt_nonce = NULL;
1546 dp = nd6_dad_find(ifa, ndopt_nonce);
1547 if (dp == NULL)
1548 return;
1549
1550 dp->dad_ns_icount++;
1551 nd6_dad_rele(dp);
1552 }
1553
1554 static void
1555 nd6_dad_na_input(struct ifaddr *ifa)
1556 {
1557 struct dadq *dp;
1558
1559 if (ifa == NULL)
1560 panic("ifa == NULL in nd6_dad_na_input");
1561
1562 dp = nd6_dad_find(ifa, NULL);
1563 if (dp != NULL) {
1564 dp->dad_na_icount++;
1565 nd6_dad_rele(dp);
1566 }
1567 }
Cache object: 323fd4b77d407b9abf9d289d805d178f
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