1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: nd6_nbr.c,v 1.86 2002/01/21 02:33:04 jinmei Exp $
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 #include "opt_ipsec.h"
38 #include "opt_mpath.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/libkern.h>
44 #include <sys/lock.h>
45 #include <sys/rwlock.h>
46 #include <sys/mbuf.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/errno.h>
52 #include <sys/sysctl.h>
53 #include <sys/syslog.h>
54 #include <sys/queue.h>
55 #include <sys/callout.h>
56 #include <sys/refcount.h>
57
58 #include <net/if.h>
59 #include <net/if_types.h>
60 #include <net/if_dl.h>
61 #include <net/if_var.h>
62 #include <net/route.h>
63 #ifdef RADIX_MPATH
64 #include <net/radix_mpath.h>
65 #endif
66 #include <net/vnet.h>
67
68 #include <netinet/in.h>
69 #include <netinet/in_var.h>
70 #include <net/if_llatbl.h>
71 #include <netinet6/in6_var.h>
72 #include <netinet6/in6_ifattach.h>
73 #include <netinet/ip6.h>
74 #include <netinet6/ip6_var.h>
75 #include <netinet6/scope6_var.h>
76 #include <netinet6/nd6.h>
77 #include <netinet/icmp6.h>
78 #include <netinet/ip_carp.h>
79 #include <netinet6/send.h>
80
81 #define SDL(s) ((struct sockaddr_dl *)s)
82
83 struct dadq;
84 static struct dadq *nd6_dad_find(struct ifaddr *, struct nd_opt_nonce *);
85 static void nd6_dad_add(struct dadq *dp);
86 static void nd6_dad_del(struct dadq *dp);
87 static void nd6_dad_rele(struct dadq *);
88 static void nd6_dad_starttimer(struct dadq *, int, int);
89 static void nd6_dad_stoptimer(struct dadq *);
90 static void nd6_dad_timer(struct dadq *);
91 static void nd6_dad_duplicated(struct ifaddr *, struct dadq *);
92 static void nd6_dad_ns_output(struct dadq *);
93 static void nd6_dad_ns_input(struct ifaddr *, struct nd_opt_nonce *);
94 static void nd6_dad_na_input(struct ifaddr *);
95 static void nd6_na_output_fib(struct ifnet *, const struct in6_addr *,
96 const struct in6_addr *, u_long, int, struct sockaddr *, u_int);
97 static void nd6_ns_output_fib(struct ifnet *, const struct in6_addr *,
98 const struct in6_addr *, const struct in6_addr *, uint8_t *, u_int);
99
100 static VNET_DEFINE(int, dad_enhanced) = 1;
101 #define V_dad_enhanced VNET(dad_enhanced)
102
103 SYSCTL_DECL(_net_inet6_ip6);
104 SYSCTL_INT(_net_inet6_ip6, OID_AUTO, dad_enhanced, CTLFLAG_VNET | CTLFLAG_RW,
105 &VNET_NAME(dad_enhanced), 0,
106 "Enable Enhanced DAD, which adds a random nonce to NS messages for DAD.");
107
108 static VNET_DEFINE(int, dad_maxtry) = 15; /* max # of *tries* to
109 transmit DAD packet */
110 #define V_dad_maxtry VNET(dad_maxtry)
111
112 /*
113 * Input a Neighbor Solicitation Message.
114 *
115 * Based on RFC 2461
116 * Based on RFC 2462 (duplicate address detection)
117 */
118 void
nd6_ns_input(struct mbuf * m,int off,int icmp6len)119 nd6_ns_input(struct mbuf *m, int off, int icmp6len)
120 {
121 struct ifnet *ifp = m->m_pkthdr.rcvif;
122 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
123 struct nd_neighbor_solicit *nd_ns;
124 struct in6_addr saddr6 = ip6->ip6_src;
125 struct in6_addr daddr6 = ip6->ip6_dst;
126 struct in6_addr taddr6;
127 struct in6_addr myaddr6;
128 char *lladdr = NULL;
129 struct ifaddr *ifa = NULL;
130 int lladdrlen = 0;
131 int anycast = 0, proxy = 0, tentative = 0;
132 int tlladdr;
133 int rflag;
134 union nd_opts ndopts;
135 struct sockaddr_dl proxydl;
136 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
137
138 rflag = (V_ip6_forwarding) ? ND_NA_FLAG_ROUTER : 0;
139 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV && V_ip6_norbit_raif)
140 rflag = 0;
141 #ifndef PULLDOWN_TEST
142 IP6_EXTHDR_CHECK(m, off, icmp6len,);
143 nd_ns = (struct nd_neighbor_solicit *)((caddr_t)ip6 + off);
144 #else
145 IP6_EXTHDR_GET(nd_ns, struct nd_neighbor_solicit *, m, off, icmp6len);
146 if (nd_ns == NULL) {
147 ICMP6STAT_INC(icp6s_tooshort);
148 return;
149 }
150 #endif
151 ip6 = mtod(m, struct ip6_hdr *); /* adjust pointer for safety */
152 taddr6 = nd_ns->nd_ns_target;
153 if (in6_setscope(&taddr6, ifp, NULL) != 0)
154 goto bad;
155
156 if (ip6->ip6_hlim != 255) {
157 nd6log((LOG_ERR,
158 "nd6_ns_input: invalid hlim (%d) from %s to %s on %s\n",
159 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
160 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
161 goto bad;
162 }
163
164 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
165 /* dst has to be a solicited node multicast address. */
166 if (daddr6.s6_addr16[0] == IPV6_ADDR_INT16_MLL &&
167 /* don't check ifindex portion */
168 daddr6.s6_addr32[1] == 0 &&
169 daddr6.s6_addr32[2] == IPV6_ADDR_INT32_ONE &&
170 daddr6.s6_addr8[12] == 0xff) {
171 ; /* good */
172 } else {
173 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
174 "(wrong ip6 dst)\n"));
175 goto bad;
176 }
177 } else if (!V_nd6_onlink_ns_rfc4861) {
178 struct sockaddr_in6 src_sa6;
179
180 /*
181 * According to recent IETF discussions, it is not a good idea
182 * to accept a NS from an address which would not be deemed
183 * to be a neighbor otherwise. This point is expected to be
184 * clarified in future revisions of the specification.
185 */
186 bzero(&src_sa6, sizeof(src_sa6));
187 src_sa6.sin6_family = AF_INET6;
188 src_sa6.sin6_len = sizeof(src_sa6);
189 src_sa6.sin6_addr = saddr6;
190 if (nd6_is_addr_neighbor(&src_sa6, ifp) == 0) {
191 nd6log((LOG_INFO, "nd6_ns_input: "
192 "NS packet from non-neighbor\n"));
193 goto bad;
194 }
195 }
196
197 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
198 nd6log((LOG_INFO, "nd6_ns_input: bad NS target (multicast)\n"));
199 goto bad;
200 }
201
202 icmp6len -= sizeof(*nd_ns);
203 nd6_option_init(nd_ns + 1, icmp6len, &ndopts);
204 if (nd6_options(&ndopts) < 0) {
205 nd6log((LOG_INFO,
206 "nd6_ns_input: invalid ND option, ignored\n"));
207 /* nd6_options have incremented stats */
208 goto freeit;
209 }
210
211 if (ndopts.nd_opts_src_lladdr) {
212 lladdr = (char *)(ndopts.nd_opts_src_lladdr + 1);
213 lladdrlen = ndopts.nd_opts_src_lladdr->nd_opt_len << 3;
214 }
215
216 if (IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_src) && lladdr) {
217 nd6log((LOG_INFO, "nd6_ns_input: bad DAD packet "
218 "(link-layer address option)\n"));
219 goto bad;
220 }
221
222 /*
223 * Attaching target link-layer address to the NA?
224 * (RFC 2461 7.2.4)
225 *
226 * NS IP dst is unicast/anycast MUST NOT add
227 * NS IP dst is solicited-node multicast MUST add
228 *
229 * In implementation, we add target link-layer address by default.
230 * We do not add one in MUST NOT cases.
231 */
232 if (!IN6_IS_ADDR_MULTICAST(&daddr6))
233 tlladdr = 0;
234 else
235 tlladdr = 1;
236
237 /*
238 * Target address (taddr6) must be either:
239 * (1) Valid unicast/anycast address for my receiving interface,
240 * (2) Unicast address for which I'm offering proxy service, or
241 * (3) "tentative" address on which DAD is being performed.
242 */
243 /* (1) and (3) check. */
244 if (ifp->if_carp)
245 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
246 else
247 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
248
249 /* (2) check. */
250 if (ifa == NULL) {
251 struct sockaddr_dl rt_gateway;
252 struct rt_addrinfo info;
253 struct sockaddr_in6 dst6;
254
255 bzero(&dst6, sizeof(dst6));
256 dst6.sin6_len = sizeof(struct sockaddr_in6);
257 dst6.sin6_family = AF_INET6;
258 dst6.sin6_addr = taddr6;
259
260 bzero(&rt_gateway, sizeof(rt_gateway));
261 rt_gateway.sdl_len = sizeof(rt_gateway);
262 bzero(&info, sizeof(info));
263 info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&rt_gateway;
264
265 /* Always use the default FIB. */
266 if (rib_lookup_info(RT_DEFAULT_FIB, (struct sockaddr *)&dst6,
267 0, 0, &info) == 0) {
268 if ((info.rti_flags & RTF_ANNOUNCE) != 0 &&
269 rt_gateway.sdl_family == AF_LINK) {
270
271 /*
272 * proxy NDP for single entry
273 */
274 proxydl = *SDL(&rt_gateway);
275 ifa = (struct ifaddr *)in6ifa_ifpforlinklocal(
276 ifp, IN6_IFF_NOTREADY|IN6_IFF_ANYCAST);
277 if (ifa)
278 proxy = 1;
279 }
280 }
281 }
282 if (ifa == NULL) {
283 /*
284 * We've got an NS packet, and we don't have that adddress
285 * assigned for us. We MUST silently ignore it.
286 * See RFC2461 7.2.3.
287 */
288 goto freeit;
289 }
290 myaddr6 = *IFA_IN6(ifa);
291 anycast = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_ANYCAST;
292 tentative = ((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE;
293 if (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_DUPLICATED)
294 goto freeit;
295
296 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
297 nd6log((LOG_INFO, "nd6_ns_input: lladdrlen mismatch for %s "
298 "(if %d, NS packet %d)\n",
299 ip6_sprintf(ip6bufs, &taddr6),
300 ifp->if_addrlen, lladdrlen - 2));
301 goto bad;
302 }
303
304 if (IN6_ARE_ADDR_EQUAL(&myaddr6, &saddr6)) {
305 nd6log((LOG_INFO, "nd6_ns_input: duplicate IP6 address %s\n",
306 ip6_sprintf(ip6bufs, &saddr6)));
307 goto freeit;
308 }
309
310 /*
311 * We have neighbor solicitation packet, with target address equals to
312 * one of my tentative address.
313 *
314 * src addr how to process?
315 * --- ---
316 * multicast of course, invalid (rejected in ip6_input)
317 * unicast somebody is doing address resolution -> ignore
318 * unspec dup address detection
319 *
320 * The processing is defined in RFC 2462.
321 */
322 if (tentative) {
323 /*
324 * If source address is unspecified address, it is for
325 * duplicate address detection.
326 *
327 * If not, the packet is for addess resolution;
328 * silently ignore it.
329 */
330 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6))
331 nd6_dad_ns_input(ifa, ndopts.nd_opts_nonce);
332
333 goto freeit;
334 }
335
336 /*
337 * If the source address is unspecified address, entries must not
338 * be created or updated.
339 * It looks that sender is performing DAD. Output NA toward
340 * all-node multicast address, to tell the sender that I'm using
341 * the address.
342 * S bit ("solicited") must be zero.
343 */
344 if (IN6_IS_ADDR_UNSPECIFIED(&saddr6)) {
345 struct in6_addr in6_all;
346
347 in6_all = in6addr_linklocal_allnodes;
348 if (in6_setscope(&in6_all, ifp, NULL) != 0)
349 goto bad;
350 nd6_na_output_fib(ifp, &in6_all, &taddr6,
351 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
352 rflag, tlladdr, proxy ? (struct sockaddr *)&proxydl : NULL,
353 M_GETFIB(m));
354 goto freeit;
355 }
356
357 nd6_cache_lladdr(ifp, &saddr6, lladdr, lladdrlen,
358 ND_NEIGHBOR_SOLICIT, 0);
359
360 nd6_na_output_fib(ifp, &saddr6, &taddr6,
361 ((anycast || proxy || !tlladdr) ? 0 : ND_NA_FLAG_OVERRIDE) |
362 rflag | ND_NA_FLAG_SOLICITED, tlladdr,
363 proxy ? (struct sockaddr *)&proxydl : NULL, M_GETFIB(m));
364 freeit:
365 if (ifa != NULL)
366 ifa_free(ifa);
367 m_freem(m);
368 return;
369
370 bad:
371 nd6log((LOG_ERR, "nd6_ns_input: src=%s\n",
372 ip6_sprintf(ip6bufs, &saddr6)));
373 nd6log((LOG_ERR, "nd6_ns_input: dst=%s\n",
374 ip6_sprintf(ip6bufs, &daddr6)));
375 nd6log((LOG_ERR, "nd6_ns_input: tgt=%s\n",
376 ip6_sprintf(ip6bufs, &taddr6)));
377 ICMP6STAT_INC(icp6s_badns);
378 if (ifa != NULL)
379 ifa_free(ifa);
380 m_freem(m);
381 }
382
383 /*
384 * Output a Neighbor Solicitation Message. Caller specifies:
385 * - ICMP6 header source IP6 address
386 * - ND6 header target IP6 address
387 * - ND6 header source datalink address
388 *
389 * Based on RFC 2461
390 * Based on RFC 2462 (duplicate address detection)
391 *
392 * ln - for source address determination
393 * nonce - If non-NULL, NS is used for duplicate address detection and
394 * the value (length is ND_OPT_NONCE_LEN) is used as a random nonce.
395 */
396 static void
nd6_ns_output_fib(struct ifnet * ifp,const struct in6_addr * saddr6,const struct in6_addr * daddr6,const struct in6_addr * taddr6,uint8_t * nonce,u_int fibnum)397 nd6_ns_output_fib(struct ifnet *ifp, const struct in6_addr *saddr6,
398 const struct in6_addr *daddr6, const struct in6_addr *taddr6,
399 uint8_t *nonce, u_int fibnum)
400 {
401 struct mbuf *m;
402 struct m_tag *mtag;
403 struct ip6_hdr *ip6;
404 struct nd_neighbor_solicit *nd_ns;
405 struct ip6_moptions im6o;
406 int icmp6len;
407 int maxlen;
408 caddr_t mac;
409
410 if (IN6_IS_ADDR_MULTICAST(taddr6))
411 return;
412
413 /* estimate the size of message */
414 maxlen = sizeof(*ip6) + sizeof(*nd_ns);
415 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
416 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
417 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
418 __func__, max_linkhdr, maxlen, MCLBYTES));
419
420 if (max_linkhdr + maxlen > MHLEN)
421 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
422 else
423 m = m_gethdr(M_NOWAIT, MT_DATA);
424 if (m == NULL)
425 return;
426 M_SETFIB(m, fibnum);
427
428 if (daddr6 == NULL || IN6_IS_ADDR_MULTICAST(daddr6)) {
429 m->m_flags |= M_MCAST;
430 im6o.im6o_multicast_ifp = ifp;
431 im6o.im6o_multicast_hlim = 255;
432 im6o.im6o_multicast_loop = 0;
433 }
434
435 icmp6len = sizeof(*nd_ns);
436 m->m_pkthdr.len = m->m_len = sizeof(*ip6) + icmp6len;
437 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
438
439 /* fill neighbor solicitation packet */
440 ip6 = mtod(m, struct ip6_hdr *);
441 ip6->ip6_flow = 0;
442 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
443 ip6->ip6_vfc |= IPV6_VERSION;
444 /* ip6->ip6_plen will be set later */
445 ip6->ip6_nxt = IPPROTO_ICMPV6;
446 ip6->ip6_hlim = 255;
447 if (daddr6)
448 ip6->ip6_dst = *daddr6;
449 else {
450 ip6->ip6_dst.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
451 ip6->ip6_dst.s6_addr16[1] = 0;
452 ip6->ip6_dst.s6_addr32[1] = 0;
453 ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_ONE;
454 ip6->ip6_dst.s6_addr32[3] = taddr6->s6_addr32[3];
455 ip6->ip6_dst.s6_addr8[12] = 0xff;
456 if (in6_setscope(&ip6->ip6_dst, ifp, NULL) != 0)
457 goto bad;
458 }
459 if (nonce == NULL) {
460 struct ifaddr *ifa = NULL;
461
462 /*
463 * RFC2461 7.2.2:
464 * "If the source address of the packet prompting the
465 * solicitation is the same as one of the addresses assigned
466 * to the outgoing interface, that address SHOULD be placed
467 * in the IP Source Address of the outgoing solicitation.
468 * Otherwise, any one of the addresses assigned to the
469 * interface should be used."
470 *
471 * We use the source address for the prompting packet
472 * (saddr6), if saddr6 belongs to the outgoing interface.
473 * Otherwise, we perform the source address selection as usual.
474 */
475
476 if (saddr6 != NULL)
477 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, saddr6);
478 if (ifa != NULL) {
479 /* ip6_src set already. */
480 ip6->ip6_src = *saddr6;
481 ifa_free(ifa);
482 } else {
483 int error;
484 struct in6_addr dst6, src6;
485 uint32_t scopeid;
486
487 in6_splitscope(&ip6->ip6_dst, &dst6, &scopeid);
488 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6,
489 scopeid, ifp, &src6, NULL);
490 if (error) {
491 char ip6buf[INET6_ADDRSTRLEN];
492 nd6log((LOG_DEBUG, "%s: source can't be "
493 "determined: dst=%s, error=%d\n", __func__,
494 ip6_sprintf(ip6buf, &dst6),
495 error));
496 goto bad;
497 }
498 ip6->ip6_src = src6;
499 }
500 } else {
501 /*
502 * Source address for DAD packet must always be IPv6
503 * unspecified address. (0::0)
504 * We actually don't have to 0-clear the address (we did it
505 * above), but we do so here explicitly to make the intention
506 * clearer.
507 */
508 bzero(&ip6->ip6_src, sizeof(ip6->ip6_src));
509 }
510 nd_ns = (struct nd_neighbor_solicit *)(ip6 + 1);
511 nd_ns->nd_ns_type = ND_NEIGHBOR_SOLICIT;
512 nd_ns->nd_ns_code = 0;
513 nd_ns->nd_ns_reserved = 0;
514 nd_ns->nd_ns_target = *taddr6;
515 in6_clearscope(&nd_ns->nd_ns_target); /* XXX */
516
517 /*
518 * Add source link-layer address option.
519 *
520 * spec implementation
521 * --- ---
522 * DAD packet MUST NOT do not add the option
523 * there's no link layer address:
524 * impossible do not add the option
525 * there's link layer address:
526 * Multicast NS MUST add one add the option
527 * Unicast NS SHOULD add one add the option
528 */
529 if (nonce == NULL && (mac = nd6_ifptomac(ifp))) {
530 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
531 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
532 /* 8 byte alignments... */
533 optlen = (optlen + 7) & ~7;
534
535 m->m_pkthdr.len += optlen;
536 m->m_len += optlen;
537 icmp6len += optlen;
538 bzero((caddr_t)nd_opt, optlen);
539 nd_opt->nd_opt_type = ND_OPT_SOURCE_LINKADDR;
540 nd_opt->nd_opt_len = optlen >> 3;
541 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
542 }
543 /*
544 * Add a Nonce option (RFC 3971) to detect looped back NS messages.
545 * This behavior is documented as Enhanced Duplicate Address
546 * Detection in RFC 7527.
547 * net.inet6.ip6.dad_enhanced=0 disables this.
548 */
549 if (V_dad_enhanced != 0 && nonce != NULL) {
550 int optlen = sizeof(struct nd_opt_hdr) + ND_OPT_NONCE_LEN;
551 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_ns + 1);
552 /* 8-byte alignment is required. */
553 optlen = (optlen + 7) & ~7;
554
555 m->m_pkthdr.len += optlen;
556 m->m_len += optlen;
557 icmp6len += optlen;
558 bzero((caddr_t)nd_opt, optlen);
559 nd_opt->nd_opt_type = ND_OPT_NONCE;
560 nd_opt->nd_opt_len = optlen >> 3;
561 bcopy(nonce, (caddr_t)(nd_opt + 1), ND_OPT_NONCE_LEN);
562 }
563 ip6->ip6_plen = htons((u_short)icmp6len);
564 nd_ns->nd_ns_cksum = 0;
565 nd_ns->nd_ns_cksum =
566 in6_cksum(m, IPPROTO_ICMPV6, sizeof(*ip6), icmp6len);
567
568 if (send_sendso_input_hook != NULL) {
569 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
570 sizeof(unsigned short), M_NOWAIT);
571 if (mtag == NULL)
572 goto bad;
573 *(unsigned short *)(mtag + 1) = nd_ns->nd_ns_type;
574 m_tag_prepend(m, mtag);
575 }
576
577 ip6_output(m, NULL, NULL, (nonce != NULL) ? IPV6_UNSPECSRC : 0,
578 &im6o, NULL, NULL);
579 icmp6_ifstat_inc(ifp, ifs6_out_msg);
580 icmp6_ifstat_inc(ifp, ifs6_out_neighborsolicit);
581 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_SOLICIT]);
582
583 return;
584
585 bad:
586 m_freem(m);
587 return;
588 }
589
590 #ifndef BURN_BRIDGES
591 void
nd6_ns_output(struct ifnet * ifp,const struct in6_addr * saddr6,const struct in6_addr * daddr6,const struct in6_addr * taddr6,uint8_t * nonce)592 nd6_ns_output(struct ifnet *ifp, const struct in6_addr *saddr6,
593 const struct in6_addr *daddr6, const struct in6_addr *taddr6,uint8_t *nonce)
594 {
595
596 nd6_ns_output_fib(ifp, saddr6, daddr6, taddr6, nonce, RT_DEFAULT_FIB);
597 }
598 #endif
599 /*
600 * Neighbor advertisement input handling.
601 *
602 * Based on RFC 2461
603 * Based on RFC 2462 (duplicate address detection)
604 *
605 * the following items are not implemented yet:
606 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
607 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
608 */
609 void
nd6_na_input(struct mbuf * m,int off,int icmp6len)610 nd6_na_input(struct mbuf *m, int off, int icmp6len)
611 {
612 struct ifnet *ifp = m->m_pkthdr.rcvif;
613 struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
614 struct nd_neighbor_advert *nd_na;
615 struct in6_addr daddr6 = ip6->ip6_dst;
616 struct in6_addr taddr6;
617 int flags;
618 int is_router;
619 int is_solicited;
620 int is_override;
621 char *lladdr = NULL;
622 int lladdrlen = 0;
623 int checklink = 0;
624 struct ifaddr *ifa;
625 struct llentry *ln = NULL;
626 union nd_opts ndopts;
627 struct mbuf *chain = NULL;
628 struct sockaddr_in6 sin6;
629 u_char linkhdr[LLE_MAX_LINKHDR];
630 size_t linkhdrsize;
631 int lladdr_off;
632 char ip6bufs[INET6_ADDRSTRLEN], ip6bufd[INET6_ADDRSTRLEN];
633
634 if (ip6->ip6_hlim != 255) {
635 nd6log((LOG_ERR,
636 "nd6_na_input: invalid hlim (%d) from %s to %s on %s\n",
637 ip6->ip6_hlim, ip6_sprintf(ip6bufs, &ip6->ip6_src),
638 ip6_sprintf(ip6bufd, &ip6->ip6_dst), if_name(ifp)));
639 goto bad;
640 }
641
642 #ifndef PULLDOWN_TEST
643 IP6_EXTHDR_CHECK(m, off, icmp6len,);
644 nd_na = (struct nd_neighbor_advert *)((caddr_t)ip6 + off);
645 #else
646 IP6_EXTHDR_GET(nd_na, struct nd_neighbor_advert *, m, off, icmp6len);
647 if (nd_na == NULL) {
648 ICMP6STAT_INC(icp6s_tooshort);
649 return;
650 }
651 #endif
652
653 flags = nd_na->nd_na_flags_reserved;
654 is_router = ((flags & ND_NA_FLAG_ROUTER) != 0);
655 is_solicited = ((flags & ND_NA_FLAG_SOLICITED) != 0);
656 is_override = ((flags & ND_NA_FLAG_OVERRIDE) != 0);
657 memset(&sin6, 0, sizeof(sin6));
658
659 taddr6 = nd_na->nd_na_target;
660 if (in6_setscope(&taddr6, ifp, NULL))
661 goto bad; /* XXX: impossible */
662
663 if (IN6_IS_ADDR_MULTICAST(&taddr6)) {
664 nd6log((LOG_ERR,
665 "nd6_na_input: invalid target address %s\n",
666 ip6_sprintf(ip6bufs, &taddr6)));
667 goto bad;
668 }
669 if (IN6_IS_ADDR_MULTICAST(&daddr6))
670 if (is_solicited) {
671 nd6log((LOG_ERR,
672 "nd6_na_input: a solicited adv is multicasted\n"));
673 goto bad;
674 }
675
676 icmp6len -= sizeof(*nd_na);
677 nd6_option_init(nd_na + 1, icmp6len, &ndopts);
678 if (nd6_options(&ndopts) < 0) {
679 nd6log((LOG_INFO,
680 "nd6_na_input: invalid ND option, ignored\n"));
681 /* nd6_options have incremented stats */
682 goto freeit;
683 }
684
685 if (ndopts.nd_opts_tgt_lladdr) {
686 lladdr = (char *)(ndopts.nd_opts_tgt_lladdr + 1);
687 lladdrlen = ndopts.nd_opts_tgt_lladdr->nd_opt_len << 3;
688 }
689
690 /*
691 * This effectively disables the DAD check on a non-master CARP
692 * address.
693 */
694 if (ifp->if_carp)
695 ifa = (*carp_iamatch6_p)(ifp, &taddr6);
696 else
697 ifa = (struct ifaddr *)in6ifa_ifpwithaddr(ifp, &taddr6);
698
699 /*
700 * Target address matches one of my interface address.
701 *
702 * If my address is tentative, this means that there's somebody
703 * already using the same address as mine. This indicates DAD failure.
704 * This is defined in RFC 2462.
705 *
706 * Otherwise, process as defined in RFC 2461.
707 */
708 if (ifa
709 && (((struct in6_ifaddr *)ifa)->ia6_flags & IN6_IFF_TENTATIVE)) {
710 nd6_dad_na_input(ifa);
711 ifa_free(ifa);
712 goto freeit;
713 }
714
715 /* Just for safety, maybe unnecessary. */
716 if (ifa) {
717 ifa_free(ifa);
718 log(LOG_ERR,
719 "nd6_na_input: duplicate IP6 address %s\n",
720 ip6_sprintf(ip6bufs, &taddr6));
721 goto freeit;
722 }
723
724 if (lladdr && ((ifp->if_addrlen + 2 + 7) & ~7) != lladdrlen) {
725 nd6log((LOG_INFO, "nd6_na_input: lladdrlen mismatch for %s "
726 "(if %d, NA packet %d)\n", ip6_sprintf(ip6bufs, &taddr6),
727 ifp->if_addrlen, lladdrlen - 2));
728 goto bad;
729 }
730
731 /*
732 * If no neighbor cache entry is found, NA SHOULD silently be
733 * discarded.
734 */
735 IF_AFDATA_RLOCK(ifp);
736 ln = nd6_lookup(&taddr6, LLE_EXCLUSIVE, ifp);
737 IF_AFDATA_RUNLOCK(ifp);
738 if (ln == NULL) {
739 goto freeit;
740 }
741
742 if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
743 /*
744 * If the link-layer has address, and no lladdr option came,
745 * discard the packet.
746 */
747 if (ifp->if_addrlen && lladdr == NULL) {
748 goto freeit;
749 }
750
751 /*
752 * Record link-layer address, and update the state.
753 */
754 linkhdrsize = sizeof(linkhdr);
755 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
756 linkhdr, &linkhdrsize, &lladdr_off) != 0)
757 return;
758 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
759 lladdr_off) == 0) {
760 ln = NULL;
761 goto freeit;
762 }
763 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
764 if (is_solicited)
765 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
766 else
767 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
768 if ((ln->ln_router = is_router) != 0) {
769 /*
770 * This means a router's state has changed from
771 * non-reachable to probably reachable, and might
772 * affect the status of associated prefixes..
773 */
774 checklink = 1;
775 }
776 } else {
777 int llchange;
778
779 /*
780 * Check if the link-layer address has changed or not.
781 */
782 if (lladdr == NULL)
783 llchange = 0;
784 else {
785 if (ln->la_flags & LLE_VALID) {
786 if (bcmp(lladdr, ln->ll_addr, ifp->if_addrlen))
787 llchange = 1;
788 else
789 llchange = 0;
790 } else
791 llchange = 1;
792 }
793
794 /*
795 * This is VERY complex. Look at it with care.
796 *
797 * override solicit lladdr llchange action
798 * (L: record lladdr)
799 *
800 * 0 0 n -- (2c)
801 * 0 0 y n (2b) L
802 * 0 0 y y (1) REACHABLE->STALE
803 * 0 1 n -- (2c) *->REACHABLE
804 * 0 1 y n (2b) L *->REACHABLE
805 * 0 1 y y (1) REACHABLE->STALE
806 * 1 0 n -- (2a)
807 * 1 0 y n (2a) L
808 * 1 0 y y (2a) L *->STALE
809 * 1 1 n -- (2a) *->REACHABLE
810 * 1 1 y n (2a) L *->REACHABLE
811 * 1 1 y y (2a) L *->REACHABLE
812 */
813 if (!is_override && (lladdr != NULL && llchange)) { /* (1) */
814 /*
815 * If state is REACHABLE, make it STALE.
816 * no other updates should be done.
817 */
818 if (ln->ln_state == ND6_LLINFO_REACHABLE)
819 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
820 goto freeit;
821 } else if (is_override /* (2a) */
822 || (!is_override && (lladdr != NULL && !llchange)) /* (2b) */
823 || lladdr == NULL) { /* (2c) */
824 /*
825 * Update link-local address, if any.
826 */
827 if (lladdr != NULL) {
828 linkhdrsize = sizeof(linkhdr);
829 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
830 linkhdr, &linkhdrsize, &lladdr_off) != 0)
831 goto freeit;
832 if (lltable_try_set_entry_addr(ifp, ln, linkhdr,
833 linkhdrsize, lladdr_off) == 0) {
834 ln = NULL;
835 goto freeit;
836 }
837 EVENTHANDLER_INVOKE(lle_event, ln,
838 LLENTRY_RESOLVED);
839 }
840
841 /*
842 * If solicited, make the state REACHABLE.
843 * If not solicited and the link-layer address was
844 * changed, make it STALE.
845 */
846 if (is_solicited)
847 nd6_llinfo_setstate(ln, ND6_LLINFO_REACHABLE);
848 else {
849 if (lladdr != NULL && llchange)
850 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
851 }
852 }
853
854 if (ln->ln_router && !is_router) {
855 /*
856 * The peer dropped the router flag.
857 * Remove the sender from the Default Router List and
858 * update the Destination Cache entries.
859 */
860 struct nd_defrouter *dr;
861 struct in6_addr *in6;
862 struct ifnet *nd6_ifp;
863
864 in6 = &ln->r_l3addr.addr6;
865
866 /*
867 * Lock to protect the default router list.
868 * XXX: this might be unnecessary, since this function
869 * is only called under the network software interrupt
870 * context. However, we keep it just for safety.
871 */
872 nd6_ifp = lltable_get_ifp(ln->lle_tbl);
873 dr = defrouter_lookup(in6, nd6_ifp);
874 if (dr)
875 defrtrlist_del(dr);
876 else if (ND_IFINFO(nd6_ifp)->flags &
877 ND6_IFF_ACCEPT_RTADV) {
878 /*
879 * Even if the neighbor is not in the default
880 * router list, the neighbor may be used
881 * as a next hop for some destinations
882 * (e.g. redirect case). So we must
883 * call rt6_flush explicitly.
884 */
885 rt6_flush(&ip6->ip6_src, ifp);
886 }
887 }
888 ln->ln_router = is_router;
889 }
890 /* XXX - QL
891 * Does this matter?
892 * rt->rt_flags &= ~RTF_REJECT;
893 */
894 ln->la_asked = 0;
895 if (ln->la_hold != NULL)
896 nd6_grab_holdchain(ln, &chain, &sin6);
897 freeit:
898 if (ln != NULL)
899 LLE_WUNLOCK(ln);
900
901 if (chain != NULL)
902 nd6_flush_holdchain(ifp, ifp, chain, &sin6);
903
904 if (checklink)
905 pfxlist_onlink_check();
906
907 m_freem(m);
908 return;
909
910 bad:
911 if (ln != NULL)
912 LLE_WUNLOCK(ln);
913
914 ICMP6STAT_INC(icp6s_badna);
915 m_freem(m);
916 }
917
918 /*
919 * Neighbor advertisement output handling.
920 *
921 * Based on RFC 2461
922 *
923 * the following items are not implemented yet:
924 * - proxy advertisement delay rule (RFC2461 7.2.8, last paragraph, SHOULD)
925 * - anycast advertisement delay rule (RFC2461 7.2.7, SHOULD)
926 *
927 * tlladdr - 1 if include target link-layer address
928 * sdl0 - sockaddr_dl (= proxy NA) or NULL
929 */
930 static void
nd6_na_output_fib(struct ifnet * ifp,const struct in6_addr * daddr6_0,const struct in6_addr * taddr6,u_long flags,int tlladdr,struct sockaddr * sdl0,u_int fibnum)931 nd6_na_output_fib(struct ifnet *ifp, const struct in6_addr *daddr6_0,
932 const struct in6_addr *taddr6, u_long flags, int tlladdr,
933 struct sockaddr *sdl0, u_int fibnum)
934 {
935 struct mbuf *m;
936 struct m_tag *mtag;
937 struct ip6_hdr *ip6;
938 struct nd_neighbor_advert *nd_na;
939 struct ip6_moptions im6o;
940 struct in6_addr daddr6, dst6, src6;
941 uint32_t scopeid;
942
943 int icmp6len, maxlen, error;
944 caddr_t mac = NULL;
945
946 daddr6 = *daddr6_0; /* make a local copy for modification */
947
948 /* estimate the size of message */
949 maxlen = sizeof(*ip6) + sizeof(*nd_na);
950 maxlen += (sizeof(struct nd_opt_hdr) + ifp->if_addrlen + 7) & ~7;
951 KASSERT(max_linkhdr + maxlen <= MCLBYTES, (
952 "%s: max_linkhdr + maxlen > MCLBYTES (%d + %d > %d)",
953 __func__, max_linkhdr, maxlen, MCLBYTES));
954
955 if (max_linkhdr + maxlen > MHLEN)
956 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
957 else
958 m = m_gethdr(M_NOWAIT, MT_DATA);
959 if (m == NULL)
960 return;
961 M_SETFIB(m, fibnum);
962
963 if (IN6_IS_ADDR_MULTICAST(&daddr6)) {
964 m->m_flags |= M_MCAST;
965 im6o.im6o_multicast_ifp = ifp;
966 im6o.im6o_multicast_hlim = 255;
967 im6o.im6o_multicast_loop = 0;
968 }
969
970 icmp6len = sizeof(*nd_na);
971 m->m_pkthdr.len = m->m_len = sizeof(struct ip6_hdr) + icmp6len;
972 m->m_data += max_linkhdr; /* or M_ALIGN() equivalent? */
973
974 /* fill neighbor advertisement packet */
975 ip6 = mtod(m, struct ip6_hdr *);
976 ip6->ip6_flow = 0;
977 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
978 ip6->ip6_vfc |= IPV6_VERSION;
979 ip6->ip6_nxt = IPPROTO_ICMPV6;
980 ip6->ip6_hlim = 255;
981 if (IN6_IS_ADDR_UNSPECIFIED(&daddr6)) {
982 /* reply to DAD */
983 daddr6.s6_addr16[0] = IPV6_ADDR_INT16_MLL;
984 daddr6.s6_addr16[1] = 0;
985 daddr6.s6_addr32[1] = 0;
986 daddr6.s6_addr32[2] = 0;
987 daddr6.s6_addr32[3] = IPV6_ADDR_INT32_ONE;
988 if (in6_setscope(&daddr6, ifp, NULL))
989 goto bad;
990
991 flags &= ~ND_NA_FLAG_SOLICITED;
992 }
993 ip6->ip6_dst = daddr6;
994
995 /*
996 * Select a source whose scope is the same as that of the dest.
997 */
998 in6_splitscope(&daddr6, &dst6, &scopeid);
999 error = in6_selectsrc_addr(RT_DEFAULT_FIB, &dst6,
1000 scopeid, ifp, &src6, NULL);
1001 if (error) {
1002 char ip6buf[INET6_ADDRSTRLEN];
1003 nd6log((LOG_DEBUG, "nd6_na_output: source can't be "
1004 "determined: dst=%s, error=%d\n",
1005 ip6_sprintf(ip6buf, &daddr6), error));
1006 goto bad;
1007 }
1008 ip6->ip6_src = src6;
1009 nd_na = (struct nd_neighbor_advert *)(ip6 + 1);
1010 nd_na->nd_na_type = ND_NEIGHBOR_ADVERT;
1011 nd_na->nd_na_code = 0;
1012 nd_na->nd_na_target = *taddr6;
1013 in6_clearscope(&nd_na->nd_na_target); /* XXX */
1014
1015 /*
1016 * "tlladdr" indicates NS's condition for adding tlladdr or not.
1017 * see nd6_ns_input() for details.
1018 * Basically, if NS packet is sent to unicast/anycast addr,
1019 * target lladdr option SHOULD NOT be included.
1020 */
1021 if (tlladdr) {
1022 /*
1023 * sdl0 != NULL indicates proxy NA. If we do proxy, use
1024 * lladdr in sdl0. If we are not proxying (sending NA for
1025 * my address) use lladdr configured for the interface.
1026 */
1027 if (sdl0 == NULL) {
1028 if (ifp->if_carp)
1029 mac = (*carp_macmatch6_p)(ifp, m, taddr6);
1030 if (mac == NULL)
1031 mac = nd6_ifptomac(ifp);
1032 } else if (sdl0->sa_family == AF_LINK) {
1033 struct sockaddr_dl *sdl;
1034 sdl = (struct sockaddr_dl *)sdl0;
1035 if (sdl->sdl_alen == ifp->if_addrlen)
1036 mac = LLADDR(sdl);
1037 }
1038 }
1039 if (tlladdr && mac) {
1040 int optlen = sizeof(struct nd_opt_hdr) + ifp->if_addrlen;
1041 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)(nd_na + 1);
1042
1043 /* roundup to 8 bytes alignment! */
1044 optlen = (optlen + 7) & ~7;
1045
1046 m->m_pkthdr.len += optlen;
1047 m->m_len += optlen;
1048 icmp6len += optlen;
1049 bzero((caddr_t)nd_opt, optlen);
1050 nd_opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
1051 nd_opt->nd_opt_len = optlen >> 3;
1052 bcopy(mac, (caddr_t)(nd_opt + 1), ifp->if_addrlen);
1053 } else
1054 flags &= ~ND_NA_FLAG_OVERRIDE;
1055
1056 ip6->ip6_plen = htons((u_short)icmp6len);
1057 nd_na->nd_na_flags_reserved = flags;
1058 nd_na->nd_na_cksum = 0;
1059 nd_na->nd_na_cksum =
1060 in6_cksum(m, IPPROTO_ICMPV6, sizeof(struct ip6_hdr), icmp6len);
1061
1062 if (send_sendso_input_hook != NULL) {
1063 mtag = m_tag_get(PACKET_TAG_ND_OUTGOING,
1064 sizeof(unsigned short), M_NOWAIT);
1065 if (mtag == NULL)
1066 goto bad;
1067 *(unsigned short *)(mtag + 1) = nd_na->nd_na_type;
1068 m_tag_prepend(m, mtag);
1069 }
1070
1071 ip6_output(m, NULL, NULL, 0, &im6o, NULL, NULL);
1072 icmp6_ifstat_inc(ifp, ifs6_out_msg);
1073 icmp6_ifstat_inc(ifp, ifs6_out_neighboradvert);
1074 ICMP6STAT_INC(icp6s_outhist[ND_NEIGHBOR_ADVERT]);
1075
1076 return;
1077
1078 bad:
1079 m_freem(m);
1080 return;
1081 }
1082
1083 #ifndef BURN_BRIDGES
1084 void
nd6_na_output(struct ifnet * ifp,const struct in6_addr * daddr6_0,const struct in6_addr * taddr6,u_long flags,int tlladdr,struct sockaddr * sdl0)1085 nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6_0,
1086 const struct in6_addr *taddr6, u_long flags, int tlladdr,
1087 struct sockaddr *sdl0)
1088 {
1089
1090 nd6_na_output_fib(ifp, daddr6_0, taddr6, flags, tlladdr, sdl0,
1091 RT_DEFAULT_FIB);
1092 }
1093 #endif
1094
1095 caddr_t
nd6_ifptomac(struct ifnet * ifp)1096 nd6_ifptomac(struct ifnet *ifp)
1097 {
1098 switch (ifp->if_type) {
1099 case IFT_ARCNET:
1100 case IFT_ETHER:
1101 case IFT_FDDI:
1102 case IFT_IEEE1394:
1103 case IFT_L2VLAN:
1104 case IFT_IEEE80211:
1105 case IFT_INFINIBAND:
1106 case IFT_BRIDGE:
1107 case IFT_ISO88025:
1108 return IF_LLADDR(ifp);
1109 default:
1110 return NULL;
1111 }
1112 }
1113
1114 struct dadq {
1115 TAILQ_ENTRY(dadq) dad_list;
1116 struct ifaddr *dad_ifa;
1117 int dad_count; /* max NS to send */
1118 int dad_ns_tcount; /* # of trials to send NS */
1119 int dad_ns_ocount; /* NS sent so far */
1120 int dad_ns_icount;
1121 int dad_na_icount;
1122 int dad_ns_lcount; /* looped back NS */
1123 int dad_loopbackprobe; /* probing state for loopback detection */
1124 struct callout dad_timer_ch;
1125 struct vnet *dad_vnet;
1126 u_int dad_refcnt;
1127 #define ND_OPT_NONCE_LEN32 \
1128 ((ND_OPT_NONCE_LEN + sizeof(uint32_t) - 1)/sizeof(uint32_t))
1129 uint32_t dad_nonce[ND_OPT_NONCE_LEN32];
1130 };
1131
1132 static VNET_DEFINE(TAILQ_HEAD(, dadq), dadq);
1133 static VNET_DEFINE(struct rwlock, dad_rwlock);
1134 #define V_dadq VNET(dadq)
1135 #define V_dad_rwlock VNET(dad_rwlock)
1136
1137 #define DADQ_RLOCK() rw_rlock(&V_dad_rwlock)
1138 #define DADQ_RUNLOCK() rw_runlock(&V_dad_rwlock)
1139 #define DADQ_WLOCK() rw_wlock(&V_dad_rwlock)
1140 #define DADQ_WUNLOCK() rw_wunlock(&V_dad_rwlock)
1141
1142 static void
nd6_dad_add(struct dadq * dp)1143 nd6_dad_add(struct dadq *dp)
1144 {
1145
1146 DADQ_WLOCK();
1147 TAILQ_INSERT_TAIL(&V_dadq, dp, dad_list);
1148 DADQ_WUNLOCK();
1149 }
1150
1151 static void
nd6_dad_del(struct dadq * dp)1152 nd6_dad_del(struct dadq *dp)
1153 {
1154
1155 DADQ_WLOCK();
1156 TAILQ_REMOVE(&V_dadq, dp, dad_list);
1157 DADQ_WUNLOCK();
1158 nd6_dad_rele(dp);
1159 }
1160
1161 static struct dadq *
nd6_dad_find(struct ifaddr * ifa,struct nd_opt_nonce * n)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
nd6_dad_starttimer(struct dadq * dp,int ticks,int send_ns)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
nd6_dad_stoptimer(struct dadq * dp)1201 nd6_dad_stoptimer(struct dadq *dp)
1202 {
1203
1204 callout_drain(&dp->dad_timer_ch);
1205 }
1206
1207 static void
nd6_dad_rele(struct dadq * dp)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
nd6_dad_init(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
nd6_dad_start(struct ifaddr * ifa,int delay)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 int send_ns;
1235
1236 /*
1237 * If we don't need DAD, don't do it.
1238 * There are several cases:
1239 * - DAD is disabled (ip6_dad_count == 0)
1240 * - the interface address is anycast
1241 */
1242 if (!(ia->ia6_flags & IN6_IFF_TENTATIVE)) {
1243 log(LOG_DEBUG,
1244 "nd6_dad_start: called with non-tentative address "
1245 "%s(%s)\n",
1246 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1247 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1248 return;
1249 }
1250 if (ia->ia6_flags & IN6_IFF_ANYCAST) {
1251 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1252 return;
1253 }
1254 if (!V_ip6_dad_count) {
1255 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1256 return;
1257 }
1258 if (ifa->ifa_ifp == NULL)
1259 panic("nd6_dad_start: ifa->ifa_ifp == NULL");
1260 if (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_NO_DAD) {
1261 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1262 return;
1263 }
1264 if (!(ifa->ifa_ifp->if_flags & IFF_UP) ||
1265 !(ifa->ifa_ifp->if_drv_flags & IFF_DRV_RUNNING) ||
1266 (ND_IFINFO(ifa->ifa_ifp)->flags & ND6_IFF_IFDISABLED)) {
1267 ia->ia6_flags |= IN6_IFF_TENTATIVE;
1268 return;
1269 }
1270 if ((dp = nd6_dad_find(ifa, NULL)) != NULL) {
1271 /*
1272 * DAD already in progress. Let the existing entry
1273 * to finish it.
1274 */
1275 return;
1276 }
1277
1278 dp = malloc(sizeof(*dp), M_IP6NDP, M_NOWAIT | M_ZERO);
1279 if (dp == NULL) {
1280 log(LOG_ERR, "nd6_dad_start: memory allocation failed for "
1281 "%s(%s)\n",
1282 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1283 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1284 return;
1285 }
1286 callout_init(&dp->dad_timer_ch, 0);
1287 #ifdef VIMAGE
1288 dp->dad_vnet = curvnet;
1289 #endif
1290 nd6log((LOG_DEBUG, "%s: starting DAD for %s\n", if_name(ifa->ifa_ifp),
1291 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1292
1293 /*
1294 * Send NS packet for DAD, ip6_dad_count times.
1295 * Note that we must delay the first transmission, if this is the
1296 * first packet to be sent from the interface after interface
1297 * (re)initialization.
1298 */
1299 dp->dad_ifa = ifa;
1300 ifa_ref(dp->dad_ifa);
1301 dp->dad_count = V_ip6_dad_count;
1302 dp->dad_ns_icount = dp->dad_na_icount = 0;
1303 dp->dad_ns_ocount = dp->dad_ns_tcount = 0;
1304 dp->dad_ns_lcount = dp->dad_loopbackprobe = 0;
1305 refcount_init(&dp->dad_refcnt, 1);
1306 nd6_dad_add(dp);
1307 send_ns = 0;
1308 if (delay == 0) {
1309 send_ns = 1;
1310 delay = (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000;
1311 }
1312 nd6_dad_starttimer(dp, delay, send_ns);
1313 }
1314
1315 /*
1316 * terminate DAD unconditionally. used for address removals.
1317 */
1318 void
nd6_dad_stop(struct ifaddr * ifa)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
1331 /*
1332 * The DAD queue entry may have been removed by nd6_dad_timer() while
1333 * we were waiting for it to stop, so re-do the lookup.
1334 */
1335 nd6_dad_rele(dp);
1336 if (nd6_dad_find(ifa, NULL) == NULL)
1337 return;
1338
1339 nd6_dad_del(dp);
1340 nd6_dad_rele(dp);
1341 }
1342
1343 static void
nd6_dad_timer(struct dadq * dp)1344 nd6_dad_timer(struct dadq *dp)
1345 {
1346 CURVNET_SET(dp->dad_vnet);
1347 struct ifaddr *ifa = dp->dad_ifa;
1348 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1349 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1350 char ip6buf[INET6_ADDRSTRLEN];
1351
1352 /* Sanity check */
1353 if (ia == NULL) {
1354 log(LOG_ERR, "nd6_dad_timer: called with null parameter\n");
1355 goto err;
1356 }
1357 if (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) {
1358 /* Do not need DAD for ifdisabled interface. */
1359 log(LOG_ERR, "nd6_dad_timer: cancel DAD on %s because of "
1360 "ND6_IFF_IFDISABLED.\n", ifp->if_xname);
1361 goto err;
1362 }
1363 if (ia->ia6_flags & IN6_IFF_DUPLICATED) {
1364 log(LOG_ERR, "nd6_dad_timer: called with duplicated address "
1365 "%s(%s)\n",
1366 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1367 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1368 goto err;
1369 }
1370 if ((ia->ia6_flags & IN6_IFF_TENTATIVE) == 0) {
1371 log(LOG_ERR, "nd6_dad_timer: called with non-tentative address "
1372 "%s(%s)\n",
1373 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1374 ifa->ifa_ifp ? if_name(ifa->ifa_ifp) : "???");
1375 goto err;
1376 }
1377
1378 /* Stop DAD if the interface is down even after dad_maxtry attempts. */
1379 if ((dp->dad_ns_tcount > V_dad_maxtry) &&
1380 (((ifp->if_flags & IFF_UP) == 0) ||
1381 ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0))) {
1382 nd6log((LOG_INFO, "%s: could not run DAD "
1383 "because the interface was down or not running.\n",
1384 if_name(ifa->ifa_ifp)));
1385 goto err;
1386 }
1387
1388 /* Need more checks? */
1389 if (dp->dad_ns_ocount < dp->dad_count) {
1390 /*
1391 * We have more NS to go. Send NS packet for DAD.
1392 */
1393 nd6_dad_starttimer(dp,
1394 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000, 1);
1395 goto done;
1396 } else {
1397 /*
1398 * We have transmitted sufficient number of DAD packets.
1399 * See what we've got.
1400 */
1401 if (dp->dad_ns_icount > 0 || dp->dad_na_icount > 0)
1402 /* We've seen NS or NA, means DAD has failed. */
1403 nd6_dad_duplicated(ifa, dp);
1404 else if (V_dad_enhanced != 0 &&
1405 dp->dad_ns_lcount > 0 &&
1406 dp->dad_ns_lcount > dp->dad_loopbackprobe) {
1407 /*
1408 * Sec. 4.1 in RFC 7527 requires transmission of
1409 * additional probes until the loopback condition
1410 * becomes clear when a looped back probe is detected.
1411 */
1412 log(LOG_ERR, "%s: a looped back NS message is "
1413 "detected during DAD for %s. "
1414 "Another DAD probes are being sent.\n",
1415 if_name(ifa->ifa_ifp),
1416 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1417 dp->dad_loopbackprobe = dp->dad_ns_lcount;
1418 /*
1419 * Send an NS immediately and increase dad_count by
1420 * V_nd6_mmaxtries - 1.
1421 */
1422 dp->dad_count =
1423 dp->dad_ns_ocount + V_nd6_mmaxtries - 1;
1424 nd6_dad_starttimer(dp,
1425 (long)ND_IFINFO(ifa->ifa_ifp)->retrans * hz / 1000,
1426 1);
1427 goto done;
1428 } else {
1429 /*
1430 * We are done with DAD. No NA came, no NS came.
1431 * No duplicate address found. Check IFDISABLED flag
1432 * again in case that it is changed between the
1433 * beginning of this function and here.
1434 */
1435 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) == 0)
1436 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1437
1438 nd6log((LOG_DEBUG,
1439 "%s: DAD complete for %s - no duplicates found\n",
1440 if_name(ifa->ifa_ifp),
1441 ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr)));
1442 if (dp->dad_ns_lcount > 0)
1443 log(LOG_ERR, "%s: DAD completed while "
1444 "a looped back NS message is detected "
1445 "during DAD for %s.\n",
1446 if_name(ifa->ifa_ifp),
1447 ip6_sprintf(ip6buf, IFA_IN6(ifa)));
1448 }
1449 }
1450 err:
1451 nd6_dad_del(dp);
1452 done:
1453 CURVNET_RESTORE();
1454 }
1455
1456 static void
nd6_dad_duplicated(struct ifaddr * ifa,struct dadq * dp)1457 nd6_dad_duplicated(struct ifaddr *ifa, struct dadq *dp)
1458 {
1459 struct in6_ifaddr *ia = (struct in6_ifaddr *)ifa;
1460 struct ifnet *ifp;
1461 char ip6buf[INET6_ADDRSTRLEN];
1462
1463 log(LOG_ERR, "%s: DAD detected duplicate IPv6 address %s: "
1464 "NS in/out/loopback=%d/%d/%d, NA in=%d\n",
1465 if_name(ifa->ifa_ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr),
1466 dp->dad_ns_icount, dp->dad_ns_ocount, dp->dad_ns_lcount,
1467 dp->dad_na_icount);
1468
1469 ia->ia6_flags &= ~IN6_IFF_TENTATIVE;
1470 ia->ia6_flags |= IN6_IFF_DUPLICATED;
1471
1472 ifp = ifa->ifa_ifp;
1473 log(LOG_ERR, "%s: DAD complete for %s - duplicate found\n",
1474 if_name(ifp), ip6_sprintf(ip6buf, &ia->ia_addr.sin6_addr));
1475 log(LOG_ERR, "%s: manual intervention required\n",
1476 if_name(ifp));
1477
1478 /*
1479 * If the address is a link-local address formed from an interface
1480 * identifier based on the hardware address which is supposed to be
1481 * uniquely assigned (e.g., EUI-64 for an Ethernet interface), IP
1482 * operation on the interface SHOULD be disabled.
1483 * [RFC 4862, Section 5.4.5]
1484 */
1485 if (IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
1486 struct in6_addr in6;
1487
1488 /*
1489 * To avoid over-reaction, we only apply this logic when we are
1490 * very sure that hardware addresses are supposed to be unique.
1491 */
1492 switch (ifp->if_type) {
1493 case IFT_ETHER:
1494 case IFT_FDDI:
1495 case IFT_ATM:
1496 case IFT_IEEE1394:
1497 case IFT_IEEE80211:
1498 case IFT_INFINIBAND:
1499 in6 = ia->ia_addr.sin6_addr;
1500 if (in6_get_hw_ifid(ifp, &in6) == 0 &&
1501 IN6_ARE_ADDR_EQUAL(&ia->ia_addr.sin6_addr, &in6)) {
1502 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1503 log(LOG_ERR, "%s: possible hardware address "
1504 "duplication detected, disable IPv6\n",
1505 if_name(ifp));
1506 }
1507 break;
1508 }
1509 }
1510 }
1511
1512 static void
nd6_dad_ns_output(struct dadq * dp)1513 nd6_dad_ns_output(struct dadq *dp)
1514 {
1515 struct in6_ifaddr *ia = (struct in6_ifaddr *)dp->dad_ifa;
1516 struct ifnet *ifp = dp->dad_ifa->ifa_ifp;
1517 int i;
1518
1519 dp->dad_ns_tcount++;
1520 if ((ifp->if_flags & IFF_UP) == 0) {
1521 return;
1522 }
1523 if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
1524 return;
1525 }
1526
1527 dp->dad_ns_ocount++;
1528 if (V_dad_enhanced != 0) {
1529 for (i = 0; i < ND_OPT_NONCE_LEN32; i++)
1530 dp->dad_nonce[i] = arc4random();
1531 /*
1532 * XXXHRS: Note that in the case that
1533 * DupAddrDetectTransmits > 1, multiple NS messages with
1534 * different nonces can be looped back in an unexpected
1535 * order. The current implementation recognizes only
1536 * the latest nonce on the sender side. Practically it
1537 * should work well in almost all cases.
1538 */
1539 }
1540 nd6_ns_output(ifp, NULL, NULL, &ia->ia_addr.sin6_addr,
1541 (uint8_t *)&dp->dad_nonce[0]);
1542 }
1543
1544 static void
nd6_dad_ns_input(struct ifaddr * ifa,struct nd_opt_nonce * ndopt_nonce)1545 nd6_dad_ns_input(struct ifaddr *ifa, struct nd_opt_nonce *ndopt_nonce)
1546 {
1547 struct in6_ifaddr *ia;
1548 struct ifnet *ifp;
1549 const struct in6_addr *taddr6;
1550 struct dadq *dp;
1551
1552 if (ifa == NULL)
1553 panic("ifa == NULL in nd6_dad_ns_input");
1554
1555 ia = (struct in6_ifaddr *)ifa;
1556 ifp = ifa->ifa_ifp;
1557 taddr6 = &ia->ia_addr.sin6_addr;
1558 /* Ignore Nonce option when Enhanced DAD is disabled. */
1559 if (V_dad_enhanced == 0)
1560 ndopt_nonce = NULL;
1561 dp = nd6_dad_find(ifa, ndopt_nonce);
1562 if (dp == NULL)
1563 return;
1564
1565 dp->dad_ns_icount++;
1566 nd6_dad_rele(dp);
1567 }
1568
1569 static void
nd6_dad_na_input(struct ifaddr * ifa)1570 nd6_dad_na_input(struct ifaddr *ifa)
1571 {
1572 struct dadq *dp;
1573
1574 if (ifa == NULL)
1575 panic("ifa == NULL in nd6_dad_na_input");
1576
1577 dp = nd6_dad_find(ifa, NULL);
1578 if (dp != NULL) {
1579 dp->dad_na_icount++;
1580 nd6_dad_rele(dp);
1581 }
1582 }
1583