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.c,v 1.144 2001/05/24 07:44:00 itojun Exp $
32 */
33
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/eventhandler.h>
40 #include <sys/callout.h>
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/mutex.h>
45 #include <sys/socket.h>
46 #include <sys/sockio.h>
47 #include <sys/time.h>
48 #include <sys/kernel.h>
49 #include <sys/protosw.h>
50 #include <sys/errno.h>
51 #include <sys/syslog.h>
52 #include <sys/rwlock.h>
53 #include <sys/queue.h>
54 #include <sys/sdt.h>
55 #include <sys/sysctl.h>
56
57 #include <net/if.h>
58 #include <net/if_var.h>
59 #include <net/if_dl.h>
60 #include <net/if_private.h>
61 #include <net/if_types.h>
62 #include <net/route.h>
63 #include <net/route/route_ctl.h>
64 #include <net/route/nhop.h>
65 #include <net/vnet.h>
66
67 #include <netinet/in.h>
68 #include <netinet/in_kdtrace.h>
69 #include <net/if_llatbl.h>
70 #include <netinet/if_ether.h>
71 #include <netinet6/in6_fib.h>
72 #include <netinet6/in6_var.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 <netinet6/in6_ifattach.h>
78 #include <netinet/icmp6.h>
79 #include <netinet6/send.h>
80
81 #include <sys/limits.h>
82
83 #include <security/mac/mac_framework.h>
84
85 #define ND6_PREFIX_WITH_ROUTER(pr) !LIST_EMPTY(&(pr)->ndpr_advrtrs)
86
87 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
88 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
89
90 VNET_DEFINE_STATIC(int, nd6_prune) = 1;
91 #define V_nd6_prune VNET(nd6_prune)
92 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_PRUNE, nd6_prune,
93 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_prune), 0,
94 "Frequency in seconds of checks for expired prefixes and routers");
95
96 VNET_DEFINE_STATIC(int, nd6_delay) = 5;
97 #define V_nd6_delay VNET(nd6_delay)
98 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DELAY, nd6_delay,
99 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_delay), 0,
100 "Delay in seconds before probing for reachability");
101
102 VNET_DEFINE_STATIC(int, nd6_umaxtries) = 3;
103 #define V_nd6_umaxtries VNET(nd6_umaxtries)
104 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_UMAXTRIES, nd6_umaxtries,
105 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_umaxtries), 0,
106 "Number of ICMPv6 NS messages sent during reachability detection");
107
108 VNET_DEFINE(int, nd6_mmaxtries) = 3;
109 #define V_nd6_mmaxtries VNET(nd6_mmaxtries)
110 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MMAXTRIES, nd6_mmaxtries,
111 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_mmaxtries), 0,
112 "Number of ICMPv6 NS messages sent during address resolution");
113
114 VNET_DEFINE_STATIC(int, nd6_gctimer) = (60 * 60 * 24); /* 1 day: garbage
115 * collection timer */
116 #define V_nd6_gctimer VNET(nd6_gctimer)
117
118 /* preventing too many loops in ND option parsing */
119 VNET_DEFINE_STATIC(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
120
121 VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 16; /* max pkts cached in unresolved
122 * ND entries */
123 #define V_nd6_maxndopt VNET(nd6_maxndopt)
124 #define V_nd6_maxqueuelen VNET(nd6_maxqueuelen)
125
126 #ifdef ND6_DEBUG
127 VNET_DEFINE(int, nd6_debug) = 1;
128 #else
129 VNET_DEFINE(int, nd6_debug) = 0;
130 #endif
131 #define V_nd6_debug VNET(nd6_debug)
132 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DEBUG, nd6_debug,
133 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_debug), 0,
134 "Log NDP debug messages");
135
136 static eventhandler_tag lle_event_eh, iflladdr_event_eh, ifnet_link_event_eh;
137
138 VNET_DEFINE(struct nd_prhead, nd_prefix);
139 VNET_DEFINE(struct rwlock, nd6_lock);
140 VNET_DEFINE(uint64_t, nd6_list_genid);
141 VNET_DEFINE(struct mtx, nd6_onlink_mtx);
142
143 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
144 #define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
145
146 int (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
147
148 static bool nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
149 struct ifnet *);
150 static void nd6_slowtimo(void *);
151 static int regen_tmpaddr(struct in6_ifaddr *);
152 static void nd6_free(struct llentry **, int);
153 static void nd6_free_redirect(const struct llentry *);
154 static void nd6_llinfo_timer(void *);
155 static void nd6_llinfo_settimer_locked(struct llentry *, long);
156 static int nd6_resolve_slow(struct ifnet *, int, int, struct mbuf *,
157 const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
158 static int nd6_need_cache(struct ifnet *);
159
160 VNET_DEFINE_STATIC(struct callout, nd6_slowtimo_ch);
161 #define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch)
162
163 VNET_DEFINE_STATIC(struct callout, nd6_timer_ch);
164 #define V_nd6_timer_ch VNET(nd6_timer_ch)
165
166 static void
nd6_lle_event(void * arg __unused,struct llentry * lle,int evt)167 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
168 {
169 struct rt_addrinfo rtinfo;
170 struct sockaddr_in6 dst;
171 struct sockaddr_dl gw;
172 struct ifnet *ifp;
173 int type;
174 int fibnum;
175
176 LLE_WLOCK_ASSERT(lle);
177
178 if (lltable_get_af(lle->lle_tbl) != AF_INET6)
179 return;
180
181 switch (evt) {
182 case LLENTRY_RESOLVED:
183 type = RTM_ADD;
184 KASSERT(lle->la_flags & LLE_VALID,
185 ("%s: %p resolved but not valid?", __func__, lle));
186 break;
187 case LLENTRY_EXPIRED:
188 type = RTM_DELETE;
189 break;
190 default:
191 return;
192 }
193
194 ifp = lltable_get_ifp(lle->lle_tbl);
195
196 bzero(&dst, sizeof(dst));
197 bzero(&gw, sizeof(gw));
198 bzero(&rtinfo, sizeof(rtinfo));
199 lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
200 dst.sin6_scope_id = in6_getscopezone(ifp,
201 in6_addrscope(&dst.sin6_addr));
202 gw.sdl_len = sizeof(struct sockaddr_dl);
203 gw.sdl_family = AF_LINK;
204 gw.sdl_alen = ifp->if_addrlen;
205 gw.sdl_index = ifp->if_index;
206 gw.sdl_type = ifp->if_type;
207 if (evt == LLENTRY_RESOLVED)
208 bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
209 rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
210 rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
211 rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
212 fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib;
213 rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
214 type == RTM_ADD ? RTF_UP: 0), 0, fibnum);
215 }
216
217 /*
218 * A handler for interface link layer address change event.
219 */
220 static void
nd6_iflladdr(void * arg __unused,struct ifnet * ifp)221 nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
222 {
223 struct ifaddr *ifa;
224 struct epoch_tracker et;
225
226 /* XXXGL: ??? */
227 if (ifp->if_inet6 == NULL)
228 return;
229
230 lltable_update_ifaddr(LLTABLE6(ifp));
231
232 if ((ifp->if_flags & IFF_UP) == 0)
233 return;
234
235 /*
236 * Sends gratuitous NAs for each ifaddr to notify other
237 * nodes about the address change.
238 */
239 NET_EPOCH_ENTER(et);
240 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
241 if (ifa->ifa_addr->sa_family == AF_INET6 &&
242 ! IN6_IS_ADDR_MULTICAST(IFA_IN6(ifa)))
243 nd6_grand_start(ifa, ND6_QUEUE_FLAG_LLADDR);
244 }
245 NET_EPOCH_EXIT(et);
246 }
247
248 void
nd6_init(void)249 nd6_init(void)
250 {
251
252 mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF);
253 rw_init(&V_nd6_lock, "nd6 list");
254
255 LIST_INIT(&V_nd_prefix);
256 nd6_defrouter_init();
257
258 /* Start timers. */
259 callout_init(&V_nd6_slowtimo_ch, 1);
260 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
261 nd6_slowtimo, curvnet);
262
263 callout_init(&V_nd6_timer_ch, 1);
264 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
265
266 nd6_dad_init();
267 if (IS_DEFAULT_VNET(curvnet)) {
268 lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
269 NULL, EVENTHANDLER_PRI_ANY);
270 iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
271 nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
272 ifnet_link_event_eh = EVENTHANDLER_REGISTER(ifnet_link_event,
273 nd6_ifnet_link_event, NULL, EVENTHANDLER_PRI_ANY);
274 }
275 }
276
277 #ifdef VIMAGE
278 void
nd6_destroy(void)279 nd6_destroy(void)
280 {
281
282 callout_drain(&V_nd6_slowtimo_ch);
283 callout_drain(&V_nd6_timer_ch);
284 if (IS_DEFAULT_VNET(curvnet)) {
285 EVENTHANDLER_DEREGISTER(ifnet_link_event, ifnet_link_event_eh);
286 EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
287 EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
288 }
289 rw_destroy(&V_nd6_lock);
290 mtx_destroy(&V_nd6_onlink_mtx);
291 }
292 #endif
293
294 void
nd6_ifattach(struct ifnet * ifp)295 nd6_ifattach(struct ifnet *ifp)
296 {
297 struct in6_ifextra *nd = ifp->if_inet6;
298
299 nd->nd_linkmtu = 0;
300 nd->nd_maxmtu = ifp->if_mtu;
301 nd->nd_basereachable = REACHABLE_TIME;
302 nd->nd_reachable = ND_COMPUTE_RTIME(nd->nd_basereachable);
303 nd->nd_retrans = RETRANS_TIMER;
304 nd->nd_recalc_timer = 0;
305 nd->nd_dad_failures = 0;
306 nd->nd_curhoplimit = IPV6_DEFHLIM;
307
308 nd->nd_flags = ND6_IFF_PERFORMNUD;
309
310 /* Set IPv6 disabled on all interfaces but loopback by default. */
311 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
312 nd->nd_flags |= ND6_IFF_IFDISABLED;
313 if (V_ip6_no_radr)
314 nd->nd_flags |= ND6_IFF_NO_RADR;
315 if (V_ip6_use_stableaddr)
316 nd->nd_flags |= ND6_IFF_STABLEADDR;
317 }
318
319 /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
320 * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
321 * default regardless of the V_ip6_auto_linklocal configuration to
322 * give a reasonable default behavior.
323 */
324 if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE &&
325 ifp->if_type != IFT_WIREGUARD) || (ifp->if_flags & IFF_LOOPBACK))
326 nd->nd_flags |= ND6_IFF_AUTO_LINKLOCAL;
327 /*
328 * A loopback interface does not need to accept RTADV.
329 * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
330 * default regardless of the V_ip6_accept_rtadv configuration to
331 * prevent the interface from accepting RA messages arrived
332 * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
333 */
334 if (V_ip6_accept_rtadv &&
335 !(ifp->if_flags & IFF_LOOPBACK) &&
336 (ifp->if_type != IFT_BRIDGE)) {
337 nd->nd_flags |= ND6_IFF_ACCEPT_RTADV;
338 /* If we globally accept rtadv, assume IPv6 on. */
339 nd->nd_flags &= ~ND6_IFF_IFDISABLED;
340 }
341
342 /* nd6 queue initialization */
343 TAILQ_INIT(&nd->nd_queue);
344 }
345
346 void
nd6_ifdetach(struct ifnet * ifp)347 nd6_ifdetach(struct ifnet *ifp)
348 {
349 struct epoch_tracker et;
350 struct ifaddr *ifa, *next;
351
352 NET_EPOCH_ENTER(et);
353 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
354 if (ifa->ifa_addr->sa_family != AF_INET6)
355 continue;
356
357 /* make sure there are no queued ND6 */
358 nd6_queue_stop(ifa);
359
360 /* stop DAD processing */
361 nd6_dad_stop(ifa);
362 }
363 NET_EPOCH_EXIT(et);
364 }
365
366 /*
367 * Reset ND level link MTU. This function is called when the physical MTU
368 * changes, which means we might have to adjust the ND level MTU.
369 * XXX todo: do not maintain copy of ifp->if_mtu in if_inet6->nd_maxmtu.
370 */
371 void
nd6_setmtu(struct ifnet * ifp)372 nd6_setmtu(struct ifnet *ifp)
373 {
374 struct in6_ifextra *ndi = ifp->if_inet6;
375 uint32_t omaxmtu;
376
377 /* XXXGL: safety against IFT_PFSYNC & IFT_PFLOG */
378 if (ndi == NULL)
379 return;
380
381 omaxmtu = ndi->nd_maxmtu;
382 ndi->nd_maxmtu = ifp->if_mtu;
383
384 /*
385 * Decreasing the interface MTU under IPV6 minimum MTU may cause
386 * undesirable situation. We thus notify the operator of the change
387 * explicitly. The check for omaxmtu is necessary to restrict the
388 * log to the case of changing the MTU, not initializing it.
389 */
390 if (omaxmtu >= IPV6_MMTU && ndi->nd_maxmtu < IPV6_MMTU) {
391 log(LOG_NOTICE, "%s: "
392 "new link MTU on %s (%lu) is too small for IPv6\n",
393 __func__, if_name(ifp), (unsigned long)ndi->nd_maxmtu);
394 }
395 }
396
397 void
nd6_option_init(void * opt,int icmp6len,union nd_opts * ndopts)398 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
399 {
400
401 bzero(ndopts, sizeof(*ndopts));
402 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
403 ndopts->nd_opts_last
404 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
405
406 if (icmp6len == 0) {
407 ndopts->nd_opts_done = 1;
408 ndopts->nd_opts_search = NULL;
409 }
410 }
411
412 /*
413 * Take one ND option.
414 */
415 struct nd_opt_hdr *
nd6_option(union nd_opts * ndopts)416 nd6_option(union nd_opts *ndopts)
417 {
418 struct nd_opt_hdr *nd_opt;
419 int olen;
420
421 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
422 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
423 __func__));
424 if (ndopts->nd_opts_search == NULL)
425 return NULL;
426 if (ndopts->nd_opts_done)
427 return NULL;
428
429 nd_opt = ndopts->nd_opts_search;
430
431 /* make sure nd_opt_len is inside the buffer */
432 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
433 bzero(ndopts, sizeof(*ndopts));
434 return NULL;
435 }
436
437 olen = nd_opt->nd_opt_len << 3;
438 /*
439 * RFC 4861 section 6.1.2: All included options
440 * must have a length that is greater than zero.
441 */
442 if (olen == 0) {
443 bzero(ndopts, sizeof(*ndopts));
444 return NULL;
445 }
446
447 ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
448 if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
449 /* option overruns the end of buffer, invalid */
450 bzero(ndopts, sizeof(*ndopts));
451 return NULL;
452 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
453 /* reached the end of options chain */
454 ndopts->nd_opts_done = 1;
455 ndopts->nd_opts_search = NULL;
456 }
457 return nd_opt;
458 }
459
460 /*
461 * Parse multiple ND options.
462 * This function is much easier to use, for ND routines that do not need
463 * multiple options of the same type.
464 */
465 int
nd6_options(union nd_opts * ndopts)466 nd6_options(union nd_opts *ndopts)
467 {
468 struct nd_opt_hdr *nd_opt;
469 int i = 0;
470
471 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
472 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
473 __func__));
474 if (ndopts->nd_opts_search == NULL)
475 return 0;
476
477 while (1) {
478 nd_opt = nd6_option(ndopts);
479 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
480 /*
481 * Message validation requires that all included
482 * options have a length that is greater than zero.
483 */
484 ICMP6STAT_INC(icp6s_nd_badopt);
485 bzero(ndopts, sizeof(*ndopts));
486 return -1;
487 }
488
489 if (nd_opt == NULL)
490 goto skip1;
491
492 switch (nd_opt->nd_opt_type) {
493 case ND_OPT_SOURCE_LINKADDR:
494 case ND_OPT_TARGET_LINKADDR:
495 case ND_OPT_MTU:
496 case ND_OPT_REDIRECTED_HEADER:
497 case ND_OPT_NONCE:
498 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
499 nd6log((LOG_INFO,
500 "duplicated ND6 option found (type=%d)\n",
501 nd_opt->nd_opt_type));
502 /* XXX bark? */
503 } else {
504 ndopts->nd_opt_array[nd_opt->nd_opt_type]
505 = nd_opt;
506 }
507 break;
508 case ND_OPT_PREFIX_INFORMATION:
509 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
510 ndopts->nd_opt_array[nd_opt->nd_opt_type]
511 = nd_opt;
512 }
513 ndopts->nd_opts_pi_end =
514 (struct nd_opt_prefix_info *)nd_opt;
515 break;
516 case ND_OPT_ROUTE_INFO:
517 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
518 ndopts->nd_opt_array[nd_opt->nd_opt_type]
519 = nd_opt;
520 }
521 ndopts->nd_opts_rti_end =
522 (struct nd_opt_route_info *)nd_opt;
523 break;
524 /* What about ND_OPT_ROUTE_INFO? RFC 4191 */
525 case ND_OPT_RDNSS: /* RFC 6106 */
526 case ND_OPT_DNSSL: /* RFC 6106 */
527 /*
528 * Silently ignore options we know and do not care about
529 * in the kernel.
530 */
531 break;
532 default:
533 /*
534 * Unknown options must be silently ignored,
535 * to accommodate future extension to the protocol.
536 */
537 nd6log((LOG_DEBUG,
538 "nd6_options: unsupported option %d - "
539 "option ignored\n", nd_opt->nd_opt_type));
540 }
541
542 skip1:
543 i++;
544 if (i > V_nd6_maxndopt) {
545 ICMP6STAT_INC(icp6s_nd_toomanyopt);
546 nd6log((LOG_INFO, "too many loop in nd opt\n"));
547 break;
548 }
549
550 if (ndopts->nd_opts_done)
551 break;
552 }
553
554 return 0;
555 }
556
557 /*
558 * ND6 timer routine to handle ND6 entries
559 */
560 static void
nd6_llinfo_settimer_locked(struct llentry * ln,long tick)561 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
562 {
563 int canceled;
564
565 LLE_WLOCK_ASSERT(ln);
566
567 /* Do not schedule timers for child LLEs. */
568 if (ln->la_flags & LLE_CHILD)
569 return;
570
571 if (tick < 0) {
572 ln->la_expire = 0;
573 ln->ln_ntick = 0;
574 canceled = callout_stop(&ln->lle_timer);
575 } else {
576 ln->la_expire = time_uptime + tick / hz;
577 LLE_ADDREF(ln);
578 if (tick > INT_MAX) {
579 ln->ln_ntick = tick - INT_MAX;
580 canceled = callout_reset(&ln->lle_timer, INT_MAX,
581 nd6_llinfo_timer, ln);
582 } else {
583 ln->ln_ntick = 0;
584 canceled = callout_reset(&ln->lle_timer, tick,
585 nd6_llinfo_timer, ln);
586 }
587 }
588 if (canceled > 0)
589 LLE_REMREF(ln);
590 }
591
592 /*
593 * Gets source address of the first packet in hold queue
594 * and stores it in @src.
595 * Returns pointer to @src (if hold queue is not empty) or NULL.
596 *
597 * Set noinline to be dtrace-friendly
598 */
599 static __noinline struct in6_addr *
nd6_llinfo_get_holdsrc(struct llentry * ln,struct in6_addr * src)600 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
601 {
602 struct ip6_hdr hdr;
603 struct mbuf *m;
604
605 if (ln->la_hold == NULL)
606 return (NULL);
607
608 /*
609 * assume every packet in la_hold has the same IP header
610 */
611 m = ln->la_hold;
612 if (sizeof(hdr) > m->m_len)
613 return (NULL);
614
615 m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
616 *src = hdr.ip6_src;
617
618 return (src);
619 }
620
621 /*
622 * Checks if we need to switch from STALE state.
623 *
624 * RFC 4861 requires switching from STALE to DELAY state
625 * on first packet matching entry, waiting V_nd6_delay and
626 * transition to PROBE state (if upper layer confirmation was
627 * not received).
628 *
629 * This code performs a bit differently:
630 * On packet hit we don't change state (but desired state
631 * can be guessed by control plane). However, after V_nd6_delay
632 * seconds code will transition to PROBE state (so DELAY state
633 * is kinda skipped in most situations).
634 *
635 * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
636 * we perform the following upon entering STALE state:
637 *
638 * 1) Arm timer to run each V_nd6_delay seconds to make sure that
639 * if packet was transmitted at the start of given interval, we
640 * would be able to switch to PROBE state in V_nd6_delay seconds
641 * as user expects.
642 *
643 * 2) Reschedule timer until original V_nd6_gctimer expires keeping
644 * lle in STALE state (remaining timer value stored in lle_remtime).
645 *
646 * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
647 * seconds ago.
648 *
649 * Returns non-zero value if the entry is still STALE (storing
650 * the next timer interval in @pdelay).
651 *
652 * Returns zero value if original timer expired or we need to switch to
653 * PROBE (store that in @do_switch variable).
654 */
655 static int
nd6_is_stale(struct llentry * lle,long * pdelay,int * do_switch)656 nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
657 {
658 int nd_delay, nd_gctimer;
659 time_t lle_hittime;
660 long delay;
661
662 *do_switch = 0;
663 nd_gctimer = V_nd6_gctimer;
664 nd_delay = V_nd6_delay;
665
666 lle_hittime = llentry_get_hittime(lle);
667
668 if (lle_hittime == 0) {
669 /*
670 * Datapath feedback has been requested upon entering
671 * STALE state. No packets has been passed using this lle.
672 * Ask for the timer reschedule and keep STALE state.
673 */
674 delay = (long)(MIN(nd_gctimer, nd_delay));
675 delay *= hz;
676 if (lle->lle_remtime > delay)
677 lle->lle_remtime -= delay;
678 else {
679 delay = lle->lle_remtime;
680 lle->lle_remtime = 0;
681 }
682
683 if (delay == 0) {
684 /*
685 * The original ng6_gctime timeout ended,
686 * no more rescheduling.
687 */
688 return (0);
689 }
690
691 *pdelay = delay;
692 return (1);
693 }
694
695 /*
696 * Packet received. Verify timestamp
697 */
698 delay = (long)(time_uptime - lle_hittime);
699 if (delay < nd_delay) {
700 /*
701 * V_nd6_delay still not passed since the first
702 * hit in STALE state.
703 * Reschedule timer and return.
704 */
705 *pdelay = (long)(nd_delay - delay) * hz;
706 return (1);
707 }
708
709 /* Request switching to probe */
710 *do_switch = 1;
711 return (0);
712 }
713
714 /*
715 * Switch @lle state to new state optionally arming timers.
716 *
717 * Set noinline to be dtrace-friendly
718 */
719 __noinline void
nd6_llinfo_setstate(struct llentry * lle,int newstate)720 nd6_llinfo_setstate(struct llentry *lle, int newstate)
721 {
722 struct ifnet *ifp;
723 int nd_gctimer, nd_delay;
724 long delay, remtime;
725
726 delay = 0;
727 remtime = 0;
728
729 switch (newstate) {
730 case ND6_LLINFO_INCOMPLETE:
731 ifp = lle->lle_tbl->llt_ifp;
732 delay = (long)ifp->if_inet6->nd_retrans * hz / 1000;
733 break;
734 case ND6_LLINFO_REACHABLE:
735 if (!ND6_LLINFO_PERMANENT(lle)) {
736 ifp = lle->lle_tbl->llt_ifp;
737 delay = (long)ifp->if_inet6->nd_reachable * hz;
738 }
739 break;
740 case ND6_LLINFO_STALE:
741
742 llentry_request_feedback(lle);
743 nd_delay = V_nd6_delay;
744 nd_gctimer = V_nd6_gctimer;
745
746 delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
747 remtime = (long)nd_gctimer * hz - delay;
748 break;
749 case ND6_LLINFO_DELAY:
750 lle->la_asked = 0;
751 delay = (long)V_nd6_delay * hz;
752 break;
753 }
754
755 if (delay > 0)
756 nd6_llinfo_settimer_locked(lle, delay);
757
758 lle->lle_remtime = remtime;
759 lle->ln_state = newstate;
760 }
761
762 /*
763 * Timer-dependent part of nd state machine.
764 *
765 * Set noinline to be dtrace-friendly
766 */
767 static __noinline void
nd6_llinfo_timer(void * arg)768 nd6_llinfo_timer(void *arg)
769 {
770 struct epoch_tracker et;
771 struct llentry *ln;
772 struct in6_addr *dst, *pdst, *psrc, src;
773 struct ifnet *ifp;
774 struct in6_ifextra *ndi;
775 int do_switch, send_ns;
776 long delay;
777
778 KASSERT(arg != NULL, ("%s: arg NULL", __func__));
779 ln = (struct llentry *)arg;
780 ifp = lltable_get_ifp(ln->lle_tbl);
781 CURVNET_SET(ifp->if_vnet);
782
783 ND6_RLOCK();
784 LLE_WLOCK(ln);
785 if (callout_pending(&ln->lle_timer)) {
786 /*
787 * Here we are a bit odd here in the treatment of
788 * active/pending. If the pending bit is set, it got
789 * rescheduled before I ran. The active
790 * bit we ignore, since if it was stopped
791 * in ll_tablefree() and was currently running
792 * it would have return 0 so the code would
793 * not have deleted it since the callout could
794 * not be stopped so we want to go through
795 * with the delete here now. If the callout
796 * was restarted, the pending bit will be back on and
797 * we just want to bail since the callout_reset would
798 * return 1 and our reference would have been removed
799 * by nd6_llinfo_settimer_locked above since canceled
800 * would have been 1.
801 */
802 LLE_WUNLOCK(ln);
803 ND6_RUNLOCK();
804 CURVNET_RESTORE();
805 return;
806 }
807 NET_EPOCH_ENTER(et);
808 ndi = ifp->if_inet6;
809 send_ns = 0;
810 dst = &ln->r_l3addr.addr6;
811 pdst = dst;
812
813 if (ln->ln_ntick > 0) {
814 if (ln->ln_ntick > INT_MAX) {
815 ln->ln_ntick -= INT_MAX;
816 nd6_llinfo_settimer_locked(ln, INT_MAX);
817 } else {
818 ln->ln_ntick = 0;
819 nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
820 }
821 goto done;
822 }
823
824 if (ln->la_flags & LLE_STATIC) {
825 goto done;
826 }
827
828 if (ln->la_flags & LLE_DELETED) {
829 nd6_free(&ln, 0);
830 goto done;
831 }
832
833 switch (ln->ln_state) {
834 case ND6_LLINFO_INCOMPLETE:
835 if (ln->la_asked < V_nd6_mmaxtries) {
836 ln->la_asked++;
837 send_ns = 1;
838 /* Send NS to multicast address */
839 pdst = NULL;
840 } else {
841 struct mbuf *m;
842
843 ICMP6STAT_ADD(icp6s_dropped, ln->la_numheld);
844
845 m = ln->la_hold;
846 if (m != NULL) {
847 /*
848 * assuming every packet in la_hold has the
849 * same IP header. Send error after unlock.
850 */
851 ln->la_hold = m->m_nextpkt;
852 m->m_nextpkt = NULL;
853 ln->la_numheld--;
854 }
855 nd6_free(&ln, 0);
856 if (m != NULL) {
857 struct mbuf *n = m;
858
859 /*
860 * if there are any ummapped mbufs, we
861 * must free them, rather than using
862 * them for an ICMP, as they cannot be
863 * checksummed.
864 */
865 while ((n = n->m_next) != NULL) {
866 if (n->m_flags & M_EXTPG)
867 break;
868 }
869 if (n != NULL) {
870 m_freem(m);
871 m = NULL;
872 } else {
873 icmp6_error2(m, ICMP6_DST_UNREACH,
874 ICMP6_DST_UNREACH_ADDR, 0, ifp);
875 }
876 }
877 }
878 break;
879 case ND6_LLINFO_REACHABLE:
880 if (!ND6_LLINFO_PERMANENT(ln))
881 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
882 break;
883
884 case ND6_LLINFO_STALE:
885 if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
886 /*
887 * No packet has used this entry and GC timeout
888 * has not been passed. Reschedule timer and
889 * return.
890 */
891 nd6_llinfo_settimer_locked(ln, delay);
892 break;
893 }
894
895 if (do_switch == 0) {
896 /*
897 * GC timer has ended and entry hasn't been used.
898 * Run Garbage collector (RFC 4861, 5.3)
899 */
900 if (!ND6_LLINFO_PERMANENT(ln))
901 nd6_free(&ln, 1);
902 break;
903 }
904
905 /* Entry has been used AND delay timer has ended. */
906
907 /* FALLTHROUGH */
908
909 case ND6_LLINFO_DELAY:
910 if ((ndi->nd_flags & ND6_IFF_PERFORMNUD) != 0) {
911 /* We need NUD */
912 ln->la_asked = 1;
913 nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
914 send_ns = 1;
915 } else
916 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
917 break;
918 case ND6_LLINFO_PROBE:
919 if (ln->la_asked < V_nd6_umaxtries) {
920 ln->la_asked++;
921 send_ns = 1;
922 } else {
923 nd6_free(&ln, 0);
924 }
925 break;
926 default:
927 panic("%s: paths in a dark night can be confusing: %d",
928 __func__, ln->ln_state);
929 }
930 done:
931 if (ln != NULL)
932 ND6_RUNLOCK();
933 if (send_ns != 0) {
934 nd6_llinfo_settimer_locked(ln,
935 (long)ndi->nd_retrans * hz / 1000);
936 psrc = nd6_llinfo_get_holdsrc(ln, &src);
937 LLE_FREE_LOCKED(ln);
938 ln = NULL;
939 nd6_ns_output(ifp, psrc, pdst, dst, NULL);
940 }
941
942 if (ln != NULL)
943 LLE_FREE_LOCKED(ln);
944 NET_EPOCH_EXIT(et);
945 CURVNET_RESTORE();
946 }
947
948 /*
949 * ND6 timer routine to expire default route list and prefix list
950 */
951 void
nd6_timer(void * arg)952 nd6_timer(void *arg)
953 {
954 CURVNET_SET((struct vnet *) arg);
955 struct epoch_tracker et;
956 struct nd_prhead prl;
957 struct nd_prefix *pr, *npr;
958 struct ifnet *ifp;
959 struct in6_ifaddr *ia6, *nia6;
960 uint64_t genid;
961
962 LIST_INIT(&prl);
963
964 NET_EPOCH_ENTER(et);
965 nd6_defrouter_timer();
966
967 /*
968 * expire interface addresses.
969 * in the past the loop was inside prefix expiry processing.
970 * However, from a stricter speci-confrmance standpoint, we should
971 * rather separate address lifetimes and prefix lifetimes.
972 *
973 * XXXRW: in6_ifaddrhead locking.
974 */
975 addrloop:
976 CK_STAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
977 /* check address lifetime */
978 if (IFA6_IS_INVALID(ia6)) {
979 int regen = 0;
980
981 /*
982 * If the expiring address is temporary, try
983 * regenerating a new one. This would be useful when
984 * we suspended a laptop PC, then turned it on after a
985 * period that could invalidate all temporary
986 * addresses. Although we may have to restart the
987 * loop (see below), it must be after purging the
988 * address. Otherwise, we'd see an infinite loop of
989 * regeneration.
990 */
991 if (V_ip6_use_tempaddr &&
992 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
993 if (regen_tmpaddr(ia6) == 0)
994 regen = 1;
995 }
996
997 in6_purgeaddr(&ia6->ia_ifa);
998
999 if (regen)
1000 goto addrloop; /* XXX: see below */
1001 } else if (IFA6_IS_DEPRECATED(ia6)) {
1002 int oldflags = ia6->ia6_flags;
1003
1004 ia6->ia6_flags |= IN6_IFF_DEPRECATED;
1005
1006 /*
1007 * If a temporary address has just become deprecated,
1008 * regenerate a new one if possible.
1009 */
1010 if (V_ip6_use_tempaddr &&
1011 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1012 (oldflags & IN6_IFF_DEPRECATED) == 0) {
1013 if (regen_tmpaddr(ia6) == 0) {
1014 /*
1015 * A new temporary address is
1016 * generated.
1017 * XXX: this means the address chain
1018 * has changed while we are still in
1019 * the loop. Although the change
1020 * would not cause disaster (because
1021 * it's not a deletion, but an
1022 * addition,) we'd rather restart the
1023 * loop just for safety. Or does this
1024 * significantly reduce performance??
1025 */
1026 goto addrloop;
1027 }
1028 }
1029 } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
1030 /*
1031 * Schedule DAD for a tentative address. This happens
1032 * if the interface was down or not running
1033 * when the address was configured.
1034 */
1035 int delay;
1036
1037 delay = arc4random() %
1038 (MAX_RTR_SOLICITATION_DELAY * hz);
1039 nd6_dad_start((struct ifaddr *)ia6, delay);
1040 } else {
1041 /*
1042 * Check status of the interface. If it is down,
1043 * mark the address as tentative for future DAD.
1044 */
1045 ifp = ia6->ia_ifp;
1046 if ((ifp->if_inet6->nd_flags & ND6_IFF_NO_DAD) == 0 &&
1047 ((ifp->if_flags & IFF_UP) == 0 ||
1048 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1049 (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED))){
1050 ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
1051 ia6->ia6_flags |= IN6_IFF_TENTATIVE;
1052 }
1053
1054 /*
1055 * A new RA might have made a deprecated address
1056 * preferred.
1057 */
1058 ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
1059 }
1060 }
1061 NET_EPOCH_EXIT(et);
1062
1063 ND6_WLOCK();
1064 restart:
1065 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1066 /*
1067 * Expire prefixes. Since the pltime is only used for
1068 * autoconfigured addresses, pltime processing for prefixes is
1069 * not necessary.
1070 *
1071 * Only unlink after all derived addresses have expired. This
1072 * may not occur until two hours after the prefix has expired
1073 * per RFC 4862. If the prefix expires before its derived
1074 * addresses, mark it off-link. This will be done automatically
1075 * after unlinking if no address references remain.
1076 */
1077 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME ||
1078 time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime)
1079 continue;
1080
1081 if (pr->ndpr_addrcnt == 0) {
1082 nd6_prefix_unlink(pr, &prl);
1083 continue;
1084 }
1085 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1086 genid = V_nd6_list_genid;
1087 nd6_prefix_ref(pr);
1088 ND6_WUNLOCK();
1089 ND6_ONLINK_LOCK();
1090 (void)nd6_prefix_offlink(pr);
1091 ND6_ONLINK_UNLOCK();
1092 ND6_WLOCK();
1093 nd6_prefix_rele(pr);
1094 if (genid != V_nd6_list_genid)
1095 goto restart;
1096 }
1097 }
1098 ND6_WUNLOCK();
1099
1100 while ((pr = LIST_FIRST(&prl)) != NULL) {
1101 LIST_REMOVE(pr, ndpr_entry);
1102 nd6_prefix_del(pr);
1103 }
1104
1105 callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
1106 nd6_timer, curvnet);
1107
1108 CURVNET_RESTORE();
1109 }
1110
1111 /*
1112 * ia6 - deprecated/invalidated temporary address
1113 */
1114 static int
regen_tmpaddr(struct in6_ifaddr * ia6)1115 regen_tmpaddr(struct in6_ifaddr *ia6)
1116 {
1117 struct ifaddr *ifa;
1118 struct ifnet *ifp;
1119 struct in6_ifaddr *public_ifa6 = NULL;
1120
1121 NET_EPOCH_ASSERT();
1122
1123 ifp = ia6->ia_ifa.ifa_ifp;
1124 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1125 struct in6_ifaddr *it6;
1126
1127 if (ifa->ifa_addr->sa_family != AF_INET6)
1128 continue;
1129
1130 it6 = (struct in6_ifaddr *)ifa;
1131
1132 /* ignore no autoconf addresses. */
1133 if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1134 continue;
1135
1136 /* ignore autoconf addresses with different prefixes. */
1137 if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
1138 continue;
1139
1140 /*
1141 * Now we are looking at an autoconf address with the same
1142 * prefix as ours. If the address is temporary and is still
1143 * preferred, do not create another one. It would be rare, but
1144 * could happen, for example, when we resume a laptop PC after
1145 * a long period.
1146 */
1147 if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1148 !IFA6_IS_DEPRECATED(it6)) {
1149 public_ifa6 = NULL;
1150 break;
1151 }
1152
1153 /*
1154 * This is a public autoconf address that has the same prefix
1155 * as ours. If it is preferred, keep it. We can't break the
1156 * loop here, because there may be a still-preferred temporary
1157 * address with the prefix.
1158 */
1159 if (!IFA6_IS_DEPRECATED(it6))
1160 public_ifa6 = it6;
1161 }
1162 if (public_ifa6 != NULL)
1163 ifa_ref(&public_ifa6->ia_ifa);
1164
1165 if (public_ifa6 != NULL) {
1166 int e;
1167
1168 if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
1169 ifa_free(&public_ifa6->ia_ifa);
1170 log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
1171 " tmp addr,errno=%d\n", e);
1172 return (-1);
1173 }
1174 ifa_free(&public_ifa6->ia_ifa);
1175 return (0);
1176 }
1177
1178 return (-1);
1179 }
1180
1181 /*
1182 * Remove prefix and default router list entries corresponding to ifp. Neighbor
1183 * cache entries are freed in in6_domifdetach().
1184 */
1185 void
nd6_purge(struct ifnet * ifp)1186 nd6_purge(struct ifnet *ifp)
1187 {
1188 struct nd_prhead prl;
1189 struct nd_prefix *pr, *npr;
1190
1191 LIST_INIT(&prl);
1192
1193 /* Purge default router list entries toward ifp. */
1194 nd6_defrouter_purge(ifp);
1195
1196 ND6_WLOCK();
1197 /*
1198 * Remove prefixes on ifp. We should have already removed addresses on
1199 * this interface, so no addresses should be referencing these prefixes.
1200 */
1201 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1202 if (pr->ndpr_ifp == ifp)
1203 nd6_prefix_unlink(pr, &prl);
1204 }
1205 ND6_WUNLOCK();
1206
1207 /* Delete the unlinked prefix objects. */
1208 while ((pr = LIST_FIRST(&prl)) != NULL) {
1209 LIST_REMOVE(pr, ndpr_entry);
1210 nd6_prefix_del(pr);
1211 }
1212
1213 /* cancel default outgoing interface setting */
1214 if (V_nd6_defifindex == ifp->if_index)
1215 nd6_setdefaultiface(0);
1216
1217 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) {
1218 /* Refresh default router list. */
1219 defrouter_select_fib(ifp->if_fib);
1220 }
1221 }
1222
1223 /*
1224 * the caller acquires and releases the lock on the lltbls
1225 * Returns the llentry locked
1226 */
1227 struct llentry *
nd6_lookup(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1228 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1229 {
1230 struct sockaddr_in6 sin6;
1231 struct llentry *ln;
1232
1233 bzero(&sin6, sizeof(sin6));
1234 sin6.sin6_len = sizeof(struct sockaddr_in6);
1235 sin6.sin6_family = AF_INET6;
1236 sin6.sin6_addr = *addr6;
1237
1238 LLTABLE_RLOCK_ASSERT(LLTABLE6(ifp));
1239
1240 ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
1241
1242 return (ln);
1243 }
1244
1245 static struct llentry *
nd6_alloc(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1246 nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1247 {
1248 struct sockaddr_in6 sin6;
1249 struct llentry *ln;
1250
1251 bzero(&sin6, sizeof(sin6));
1252 sin6.sin6_len = sizeof(struct sockaddr_in6);
1253 sin6.sin6_family = AF_INET6;
1254 sin6.sin6_addr = *addr6;
1255
1256 ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
1257 if (ln != NULL)
1258 ln->ln_state = ND6_LLINFO_NOSTATE;
1259
1260 return (ln);
1261 }
1262
1263 /*
1264 * Test whether a given IPv6 address can be a neighbor.
1265 */
1266 static bool
nd6_is_new_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1267 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1268 {
1269
1270 /*
1271 * A link-local address is always a neighbor.
1272 * XXX: a link does not necessarily specify a single interface.
1273 */
1274 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
1275 struct sockaddr_in6 sin6_copy;
1276 u_int32_t zone;
1277
1278 /*
1279 * We need sin6_copy since sa6_recoverscope() may modify the
1280 * content (XXX).
1281 */
1282 sin6_copy = *addr;
1283 if (sa6_recoverscope(&sin6_copy))
1284 return (0); /* XXX: should be impossible */
1285 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
1286 return (0);
1287 if (sin6_copy.sin6_scope_id == zone)
1288 return (1);
1289 else
1290 return (0);
1291 }
1292 /* Checking global unicast */
1293
1294 /* If an address is directly reachable, it is a neigbor */
1295 struct nhop_object *nh;
1296 nh = fib6_lookup(ifp->if_fib, &addr->sin6_addr, 0, NHR_NONE, 0);
1297 if (nh != NULL && nh->nh_aifp == ifp && (nh->nh_flags & NHF_GATEWAY) == 0)
1298 return (true);
1299
1300 /*
1301 * Check prefixes with desired on-link state, as some may be not
1302 * installed in the routing table.
1303 */
1304 bool matched = false;
1305 struct nd_prefix *pr;
1306 ND6_RLOCK();
1307 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1308 if (pr->ndpr_ifp != ifp)
1309 continue;
1310 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1311 continue;
1312 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1313 &addr->sin6_addr, &pr->ndpr_mask)) {
1314 matched = true;
1315 break;
1316 }
1317 }
1318 ND6_RUNLOCK();
1319 if (matched)
1320 return (true);
1321
1322 /*
1323 * If the address is assigned on the node of the other side of
1324 * a p2p interface, the address should be a neighbor.
1325 */
1326 if (ifp->if_flags & IFF_POINTOPOINT) {
1327 struct ifaddr *ifa;
1328
1329 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1330 if (ifa->ifa_addr->sa_family != addr->sin6_family)
1331 continue;
1332 if (ifa->ifa_dstaddr != NULL &&
1333 sa_equal(addr, ifa->ifa_dstaddr)) {
1334 return (true);
1335 }
1336 }
1337 }
1338
1339 /*
1340 * If the default router list is empty, all addresses are regarded
1341 * as on-link, and thus, as a neighbor.
1342 */
1343 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV &&
1344 nd6_defrouter_list_empty() &&
1345 V_nd6_defifindex == ifp->if_index) {
1346 return (1);
1347 }
1348
1349 return (0);
1350 }
1351
1352 /*
1353 * Detect if a given IPv6 address identifies a neighbor on a given link.
1354 * XXX: should take care of the destination of a p2p link?
1355 */
1356 int
nd6_is_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1357 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1358 {
1359 struct llentry *lle;
1360 int rc = 0;
1361
1362 NET_EPOCH_ASSERT();
1363
1364 if (nd6_is_new_addr_neighbor(addr, ifp))
1365 return (1);
1366
1367 /*
1368 * Even if the address matches none of our addresses, it might be
1369 * in the neighbor cache.
1370 */
1371 if ((lle = nd6_lookup(&addr->sin6_addr, LLE_SF(AF_INET6, 0), ifp)) != NULL) {
1372 LLE_RUNLOCK(lle);
1373 rc = 1;
1374 }
1375 return (rc);
1376 }
1377
1378 static __noinline void
nd6_free_children(struct llentry * lle)1379 nd6_free_children(struct llentry *lle)
1380 {
1381 struct llentry *child_lle;
1382
1383 NET_EPOCH_ASSERT();
1384 LLE_WLOCK_ASSERT(lle);
1385
1386 while ((child_lle = CK_SLIST_FIRST(&lle->lle_children)) != NULL) {
1387 LLE_WLOCK(child_lle);
1388 lltable_unlink_child_entry(child_lle);
1389 llentry_free(child_lle);
1390 }
1391 }
1392
1393 /*
1394 * Tries to update @lle address/prepend data with new @lladdr.
1395 *
1396 * Returns true on success.
1397 * In any case, @lle is returned wlocked.
1398 */
1399 static __noinline bool
nd6_try_set_entry_addr_locked(struct ifnet * ifp,struct llentry * lle,char * lladdr)1400 nd6_try_set_entry_addr_locked(struct ifnet *ifp, struct llentry *lle, char *lladdr)
1401 {
1402 u_char buf[LLE_MAX_LINKHDR];
1403 int fam, off;
1404 size_t sz;
1405
1406 sz = sizeof(buf);
1407 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, buf, &sz, &off) != 0)
1408 return (false);
1409
1410 /* Update data */
1411 lltable_set_entry_addr(ifp, lle, buf, sz, off);
1412
1413 struct llentry *child_lle;
1414 CK_SLIST_FOREACH(child_lle, &lle->lle_children, lle_child_next) {
1415 LLE_WLOCK(child_lle);
1416 fam = child_lle->r_family;
1417 sz = sizeof(buf);
1418 if (lltable_calc_llheader(ifp, fam, lladdr, buf, &sz, &off) == 0) {
1419 /* success */
1420 lltable_set_entry_addr(ifp, child_lle, buf, sz, off);
1421 child_lle->ln_state = ND6_LLINFO_REACHABLE;
1422 }
1423 LLE_WUNLOCK(child_lle);
1424 }
1425
1426 return (true);
1427 }
1428
1429 bool
nd6_try_set_entry_addr(struct ifnet * ifp,struct llentry * lle,char * lladdr)1430 nd6_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle, char *lladdr)
1431 {
1432 NET_EPOCH_ASSERT();
1433 LLE_WLOCK_ASSERT(lle);
1434
1435 if (!lltable_trylock(lle))
1436 return (false);
1437 bool ret = nd6_try_set_entry_addr_locked(ifp, lle, lladdr);
1438 LLTABLE_UNLOCK(lle->lle_tbl);
1439
1440 return (ret);
1441 }
1442
1443 /*
1444 * Free an nd6 llinfo entry.
1445 * Since the function would cause significant changes in the kernel, DO NOT
1446 * make it global, unless you have a strong reason for the change, and are sure
1447 * that the change is safe.
1448 *
1449 * Set noinline to be dtrace-friendly
1450 */
1451 static __noinline void
nd6_free(struct llentry ** lnp,int gc)1452 nd6_free(struct llentry **lnp, int gc)
1453 {
1454 struct ifnet *ifp;
1455 struct llentry *ln;
1456 struct nd_defrouter *dr;
1457
1458 ln = *lnp;
1459 *lnp = NULL;
1460
1461 LLE_WLOCK_ASSERT(ln);
1462 ND6_RLOCK_ASSERT();
1463
1464 KASSERT((ln->la_flags & LLE_CHILD) == 0, ("child lle"));
1465
1466 ifp = lltable_get_ifp(ln->lle_tbl);
1467 if ((ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) != 0)
1468 dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
1469 else
1470 dr = NULL;
1471 ND6_RUNLOCK();
1472
1473 if ((ln->la_flags & LLE_DELETED) == 0)
1474 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
1475
1476 /*
1477 * we used to have pfctlinput(PRC_HOSTDEAD) here.
1478 * even though it is not harmful, it was not really necessary.
1479 */
1480
1481 /* cancel timer */
1482 nd6_llinfo_settimer_locked(ln, -1);
1483
1484 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) {
1485 if (dr != NULL && dr->expire &&
1486 ln->ln_state == ND6_LLINFO_STALE && gc) {
1487 /*
1488 * If the reason for the deletion is just garbage
1489 * collection, and the neighbor is an active default
1490 * router, do not delete it. Instead, reset the GC
1491 * timer using the router's lifetime.
1492 * Simply deleting the entry would affect default
1493 * router selection, which is not necessarily a good
1494 * thing, especially when we're using router preference
1495 * values.
1496 * XXX: the check for ln_state would be redundant,
1497 * but we intentionally keep it just in case.
1498 */
1499 if (dr->expire > time_uptime)
1500 nd6_llinfo_settimer_locked(ln,
1501 (dr->expire - time_uptime) * hz);
1502 else
1503 nd6_llinfo_settimer_locked(ln,
1504 (long)V_nd6_gctimer * hz);
1505
1506 LLE_REMREF(ln);
1507 LLE_WUNLOCK(ln);
1508 defrouter_rele(dr);
1509 return;
1510 }
1511
1512 if (dr) {
1513 /*
1514 * Unreachability of a router might affect the default
1515 * router selection and on-link detection of advertised
1516 * prefixes.
1517 */
1518
1519 /*
1520 * Temporarily fake the state to choose a new default
1521 * router and to perform on-link determination of
1522 * prefixes correctly.
1523 * Below the state will be set correctly,
1524 * or the entry itself will be deleted.
1525 */
1526 ln->ln_state = ND6_LLINFO_INCOMPLETE;
1527 }
1528
1529 if (ln->ln_router || dr) {
1530 /*
1531 * We need to unlock to avoid a LOR with rt6_flush() with the
1532 * rnh and for the calls to pfxlist_onlink_check() and
1533 * defrouter_select_fib() in the block further down for calls
1534 * into nd6_lookup(). We still hold a ref.
1535 */
1536 LLE_WUNLOCK(ln);
1537
1538 /*
1539 * rt6_flush must be called whether or not the neighbor
1540 * is in the Default Router List.
1541 * See a corresponding comment in nd6_na_input().
1542 */
1543 rt6_flush(&ln->r_l3addr.addr6, ifp);
1544 }
1545
1546 if (dr) {
1547 /*
1548 * Since defrouter_select_fib() does not affect the
1549 * on-link determination and MIP6 needs the check
1550 * before the default router selection, we perform
1551 * the check now.
1552 */
1553 pfxlist_onlink_check();
1554
1555 /*
1556 * Refresh default router list.
1557 */
1558 defrouter_select_fib(dr->ifp->if_fib);
1559 }
1560
1561 /*
1562 * If this entry was added by an on-link redirect, remove the
1563 * corresponding host route.
1564 */
1565 if (ln->la_flags & LLE_REDIRECT)
1566 nd6_free_redirect(ln);
1567
1568 if (ln->ln_router || dr)
1569 LLE_WLOCK(ln);
1570 }
1571
1572 /*
1573 * Save to unlock. We still hold an extra reference and will not
1574 * free(9) in llentry_free() if someone else holds one as well.
1575 */
1576 LLE_WUNLOCK(ln);
1577 LLTABLE_LOCK(ln->lle_tbl);
1578 LLE_WLOCK(ln);
1579 /* Guard against race with other llentry_free(). */
1580 if (ln->la_flags & LLE_LINKED) {
1581 /* Remove callout reference */
1582 LLE_REMREF(ln);
1583 lltable_unlink_entry(ln->lle_tbl, ln);
1584 }
1585 LLTABLE_UNLOCK(ln->lle_tbl);
1586
1587 nd6_free_children(ln);
1588
1589 llentry_free(ln);
1590 if (dr != NULL)
1591 defrouter_rele(dr);
1592 }
1593
1594 static int
nd6_isdynrte(const struct rtentry * rt,const struct nhop_object * nh,void * xap)1595 nd6_isdynrte(const struct rtentry *rt, const struct nhop_object *nh, void *xap)
1596 {
1597
1598 if (nh->nh_flags & NHF_REDIRECT)
1599 return (1);
1600
1601 return (0);
1602 }
1603
1604 /*
1605 * Remove the rtentry for the given llentry,
1606 * both of which were installed by a redirect.
1607 */
1608 static void
nd6_free_redirect(const struct llentry * ln)1609 nd6_free_redirect(const struct llentry *ln)
1610 {
1611 int fibnum;
1612 struct sockaddr_in6 sin6;
1613 struct rib_cmd_info rc;
1614 struct epoch_tracker et;
1615
1616 lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
1617
1618 NET_EPOCH_ENTER(et);
1619 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
1620 rib_del_route_px(fibnum, (struct sockaddr *)&sin6, 128,
1621 nd6_isdynrte, NULL, 0, &rc);
1622 NET_EPOCH_EXIT(et);
1623 }
1624
1625 /*
1626 * Updates status of the default router route.
1627 */
1628 static void
check_release_defrouter(const struct rib_cmd_info * rc,void * _cbdata)1629 check_release_defrouter(const struct rib_cmd_info *rc, void *_cbdata)
1630 {
1631 struct nd_defrouter *dr;
1632 struct nhop_object *nh;
1633
1634 nh = rc->rc_nh_old;
1635 if (rc->rc_cmd == RTM_DELETE && (nh->nh_flags & NHF_DEFAULT) != 0) {
1636 dr = defrouter_lookup(&nh->gw6_sa.sin6_addr, nh->nh_ifp);
1637 if (dr != NULL) {
1638 dr->installed = 0;
1639 defrouter_rele(dr);
1640 }
1641 }
1642 }
1643
1644 void
nd6_subscription_cb(struct rib_head * rnh,struct rib_cmd_info * rc,void * arg)1645 nd6_subscription_cb(struct rib_head *rnh, struct rib_cmd_info *rc, void *arg)
1646 {
1647
1648 rib_decompose_notification(rc, check_release_defrouter, NULL);
1649 if (rc->rc_cmd == RTM_DELETE && !NH_IS_NHGRP(rc->rc_nh_old))
1650 check_release_defrouter(rc, NULL);
1651 }
1652
1653 int
nd6_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp)1654 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
1655 {
1656 struct epoch_tracker et;
1657 struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1658 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1659 struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1660 struct in6_ifextra *ext = ifp->if_inet6;
1661 int error = 0;
1662
1663 /* XXXGL: safety against IFT_PFSYNC & IFT_PFLOG */
1664 if (ext == NULL)
1665 return (EPFNOSUPPORT);
1666 #define ND ndi->ndi
1667 switch (cmd) {
1668 case SIOCGIFINFO_IN6:
1669 ND = (struct nd_ifinfo){
1670 .linkmtu = ext->nd_linkmtu,
1671 .maxmtu = ext->nd_maxmtu,
1672 .basereachable = ext->nd_basereachable,
1673 .reachable = ext->nd_reachable,
1674 .retrans = ext->nd_retrans,
1675 .flags = ext->nd_flags,
1676 .recalctm = ext->nd_recalc_timer,
1677 .chlim = ext->nd_curhoplimit,
1678 .initialized = 1,
1679 };
1680 break;
1681 case SIOCSIFINFO_IN6:
1682 /*
1683 * used to change host variables from userland.
1684 * intended for a use on router to reflect RA configurations.
1685 */
1686 /* 0 means 'unspecified' */
1687 if (ND.linkmtu != 0) {
1688 if (ND.linkmtu < IPV6_MMTU ||
1689 ND.linkmtu > in6_ifmtu(ifp)) {
1690 error = EINVAL;
1691 break;
1692 }
1693 ext->nd_linkmtu = ND.linkmtu;
1694 }
1695
1696 if (ND.basereachable != 0) {
1697 uint32_t obasereachable = ext->nd_basereachable;
1698
1699 ext->nd_basereachable = ND.basereachable;
1700 if (ND.basereachable != obasereachable)
1701 ext->nd_reachable =
1702 ND_COMPUTE_RTIME(ND.basereachable);
1703 }
1704 if (ND.retrans != 0)
1705 ext->nd_retrans = ND.retrans;
1706 if (ND.chlim != 0)
1707 ext->nd_curhoplimit = ND.chlim;
1708 /* FALLTHROUGH */
1709 case SIOCSIFINFO_FLAGS:
1710 {
1711 struct ifaddr *ifa;
1712 struct in6_ifaddr *ia;
1713
1714 if ((ext->nd_flags & ND6_IFF_IFDISABLED) &&
1715 !(ND.flags & ND6_IFF_IFDISABLED)) {
1716 /* ifdisabled 1->0 transision */
1717
1718 /*
1719 * If the interface is marked as ND6_IFF_IFDISABLED and
1720 * has an link-local address with IN6_IFF_DUPLICATED,
1721 * do not clear ND6_IFF_IFDISABLED.
1722 * See RFC 4862, Section 5.4.5.
1723 */
1724 NET_EPOCH_ENTER(et);
1725 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1726 if (ifa->ifa_addr->sa_family != AF_INET6)
1727 continue;
1728 ia = (struct in6_ifaddr *)ifa;
1729 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1730 IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1731 break;
1732 }
1733 NET_EPOCH_EXIT(et);
1734
1735 if (ifa != NULL) {
1736 /* LLA is duplicated. */
1737 ND.flags |= ND6_IFF_IFDISABLED;
1738 log(LOG_ERR, "Cannot enable an interface"
1739 " with a link-local address marked"
1740 " duplicate.\n");
1741 } else {
1742 ext->nd_flags &= ~ND6_IFF_IFDISABLED;
1743 if (ifp->if_flags & IFF_UP)
1744 in6_if_up(ifp);
1745 }
1746 } else if (!(ext->nd_flags & ND6_IFF_IFDISABLED) &&
1747 (ND.flags & ND6_IFF_IFDISABLED)) {
1748 /* ifdisabled 0->1 transision */
1749 /* Mark all IPv6 address as tentative. */
1750
1751 ext->nd_flags |= ND6_IFF_IFDISABLED;
1752 if (V_ip6_dad_count > 0 &&
1753 (ext->nd_flags & ND6_IFF_NO_DAD) == 0) {
1754 NET_EPOCH_ENTER(et);
1755 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1756 ifa_link) {
1757 if (ifa->ifa_addr->sa_family !=
1758 AF_INET6)
1759 continue;
1760 ia = (struct in6_ifaddr *)ifa;
1761 ia->ia6_flags |= IN6_IFF_TENTATIVE;
1762 }
1763 NET_EPOCH_EXIT(et);
1764 }
1765 }
1766
1767 if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1768 if (!(ext->nd_flags & ND6_IFF_AUTO_LINKLOCAL)) {
1769 /* auto_linklocal 0->1 transision */
1770
1771 /* If no link-local address on ifp, configure */
1772 ext->nd_flags |= ND6_IFF_AUTO_LINKLOCAL;
1773 in6_ifattach(ifp, NULL);
1774 } else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1775 ifp->if_flags & IFF_UP) {
1776 /*
1777 * When the IF already has
1778 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1779 * address is assigned, and IFF_UP, try to
1780 * assign one.
1781 */
1782 NET_EPOCH_ENTER(et);
1783 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1784 ifa_link) {
1785 if (ifa->ifa_addr->sa_family !=
1786 AF_INET6)
1787 continue;
1788 ia = (struct in6_ifaddr *)ifa;
1789 if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1790 break;
1791 }
1792 NET_EPOCH_EXIT(et);
1793 if (ifa != NULL)
1794 /* No LLA is configured. */
1795 in6_ifattach(ifp, NULL);
1796 }
1797 }
1798 ext->nd_flags = ND.flags;
1799 break;
1800 }
1801 #undef ND
1802 case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */
1803 /* sync kernel routing table with the default router list */
1804 defrouter_reset();
1805 defrouter_select_fib(RT_ALL_FIBS);
1806 break;
1807 case SIOCSPFXFLUSH_IN6:
1808 {
1809 /* flush all the prefix advertised by routers */
1810 struct in6_ifaddr *ia, *ia_next;
1811 struct nd_prefix *pr, *next;
1812 struct nd_prhead prl;
1813
1814 LIST_INIT(&prl);
1815
1816 ND6_WLOCK();
1817 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
1818 if (ND6_PREFIX_WITH_ROUTER(pr))
1819 nd6_prefix_unlink(pr, &prl);
1820 }
1821 ND6_WUNLOCK();
1822
1823 while ((pr = LIST_FIRST(&prl)) != NULL) {
1824 LIST_REMOVE(pr, ndpr_entry);
1825 /* XXXRW: in6_ifaddrhead locking. */
1826 CK_STAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
1827 ia_next) {
1828 if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1829 continue;
1830
1831 if (ia->ia6_ndpr == pr)
1832 in6_purgeaddr(&ia->ia_ifa);
1833 }
1834 nd6_prefix_del(pr);
1835 }
1836 break;
1837 }
1838 case SIOCSRTRFLUSH_IN6:
1839 {
1840 /* flush all the default routers */
1841
1842 defrouter_reset();
1843 nd6_defrouter_flush_all();
1844 defrouter_select_fib(RT_ALL_FIBS);
1845 break;
1846 }
1847 case SIOCGNBRINFO_IN6:
1848 {
1849 struct llentry *ln;
1850 struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1851
1852 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1853 return (error);
1854
1855 NET_EPOCH_ENTER(et);
1856 ln = nd6_lookup(&nb_addr, LLE_SF(AF_INET6, 0), ifp);
1857 NET_EPOCH_EXIT(et);
1858
1859 if (ln == NULL) {
1860 error = EINVAL;
1861 break;
1862 }
1863 nbi->state = ln->ln_state;
1864 nbi->asked = ln->la_asked;
1865 nbi->isrouter = ln->ln_router;
1866 if (ln->la_expire == 0)
1867 nbi->expire = 0;
1868 else
1869 nbi->expire = ln->la_expire + ln->lle_remtime / hz +
1870 (time_second - time_uptime);
1871 LLE_RUNLOCK(ln);
1872 break;
1873 }
1874 case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1875 ndif->ifindex = V_nd6_defifindex;
1876 break;
1877 case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1878 return (nd6_setdefaultiface(ndif->ifindex));
1879 }
1880 return (error);
1881 }
1882
1883 /*
1884 * Calculates new isRouter value based on provided parameters and
1885 * returns it.
1886 */
1887 static int
nd6_is_router(int type,int code,int is_new,int old_addr,int new_addr,int ln_router)1888 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
1889 int ln_router)
1890 {
1891
1892 /*
1893 * ICMP6 type dependent behavior.
1894 *
1895 * NS: clear IsRouter if new entry
1896 * RS: clear IsRouter
1897 * RA: set IsRouter if there's lladdr
1898 * redir: clear IsRouter if new entry
1899 *
1900 * RA case, (1):
1901 * The spec says that we must set IsRouter in the following cases:
1902 * - If lladdr exist, set IsRouter. This means (1-5).
1903 * - If it is old entry (!newentry), set IsRouter. This means (7).
1904 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1905 * A quetion arises for (1) case. (1) case has no lladdr in the
1906 * neighbor cache, this is similar to (6).
1907 * This case is rare but we figured that we MUST NOT set IsRouter.
1908 *
1909 * is_new old_addr new_addr NS RS RA redir
1910 * D R
1911 * 0 n n (1) c ? s
1912 * 0 y n (2) c s s
1913 * 0 n y (3) c s s
1914 * 0 y y (4) c s s
1915 * 0 y y (5) c s s
1916 * 1 -- n (6) c c c s
1917 * 1 -- y (7) c c s c s
1918 *
1919 * (c=clear s=set)
1920 */
1921 switch (type & 0xff) {
1922 case ND_NEIGHBOR_SOLICIT:
1923 /*
1924 * New entry must have is_router flag cleared.
1925 */
1926 if (is_new) /* (6-7) */
1927 ln_router = 0;
1928 break;
1929 case ND_REDIRECT:
1930 /*
1931 * If the icmp is a redirect to a better router, always set the
1932 * is_router flag. Otherwise, if the entry is newly created,
1933 * clear the flag. [RFC 2461, sec 8.3]
1934 */
1935 if (code == ND_REDIRECT_ROUTER)
1936 ln_router = 1;
1937 else {
1938 if (is_new) /* (6-7) */
1939 ln_router = 0;
1940 }
1941 break;
1942 case ND_ROUTER_SOLICIT:
1943 /*
1944 * is_router flag must always be cleared.
1945 */
1946 ln_router = 0;
1947 break;
1948 case ND_ROUTER_ADVERT:
1949 /*
1950 * Mark an entry with lladdr as a router.
1951 */
1952 if ((!is_new && (old_addr || new_addr)) || /* (2-5) */
1953 (is_new && new_addr)) { /* (7) */
1954 ln_router = 1;
1955 }
1956 break;
1957 }
1958
1959 return (ln_router);
1960 }
1961
1962 /*
1963 * Create neighbor cache entry and cache link-layer address,
1964 * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1965 *
1966 * type - ICMP6 type
1967 * code - type dependent information
1968 *
1969 */
1970 void
nd6_cache_lladdr(struct ifnet * ifp,struct in6_addr * from,char * lladdr,int lladdrlen,int type,int code)1971 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1972 int lladdrlen, int type, int code)
1973 {
1974 struct llentry *ln = NULL, *ln_tmp;
1975 int is_newentry;
1976 int do_update;
1977 int olladdr;
1978 int llchange;
1979 int flags;
1980 uint16_t router = 0;
1981 struct mbuf *chain = NULL;
1982 u_char linkhdr[LLE_MAX_LINKHDR];
1983 size_t linkhdrsize;
1984 int lladdr_off;
1985
1986 NET_EPOCH_ASSERT();
1987
1988 KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
1989 KASSERT(from != NULL, ("%s: from == NULL", __func__));
1990
1991 /* nothing must be updated for unspecified address */
1992 if (IN6_IS_ADDR_UNSPECIFIED(from))
1993 return;
1994
1995 /*
1996 * Validation about ifp->if_addrlen and lladdrlen must be done in
1997 * the caller.
1998 *
1999 * XXX If the link does not have link-layer adderss, what should
2000 * we do? (ifp->if_addrlen == 0)
2001 * Spec says nothing in sections for RA, RS and NA. There's small
2002 * description on it in NS section (RFC 2461 7.2.3).
2003 */
2004 flags = lladdr ? LLE_EXCLUSIVE : 0;
2005 ln = nd6_lookup(from, LLE_SF(AF_INET6, flags), ifp);
2006 is_newentry = 0;
2007 if (ln == NULL) {
2008 flags |= LLE_EXCLUSIVE;
2009 ln = nd6_alloc(from, 0, ifp);
2010 if (ln == NULL)
2011 return;
2012
2013 /*
2014 * Since we already know all the data for the new entry,
2015 * fill it before insertion.
2016 */
2017 if (lladdr != NULL) {
2018 linkhdrsize = sizeof(linkhdr);
2019 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
2020 linkhdr, &linkhdrsize, &lladdr_off) != 0) {
2021 lltable_free_entry(LLTABLE6(ifp), ln);
2022 return;
2023 }
2024 lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
2025 lladdr_off);
2026 }
2027
2028 LLTABLE_LOCK(LLTABLE6(ifp));
2029 LLE_WLOCK(ln);
2030 /* Prefer any existing lle over newly-created one */
2031 ln_tmp = nd6_lookup(from, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
2032 if (ln_tmp == NULL)
2033 lltable_link_entry(LLTABLE6(ifp), ln);
2034 LLTABLE_UNLOCK(LLTABLE6(ifp));
2035 if (ln_tmp == NULL) {
2036 /* No existing lle, mark as new entry (6,7) */
2037 is_newentry = 1;
2038 if (lladdr != NULL) { /* (7) */
2039 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2040 EVENTHANDLER_INVOKE(lle_event, ln,
2041 LLENTRY_RESOLVED);
2042 }
2043 } else {
2044 lltable_free_entry(LLTABLE6(ifp), ln);
2045 ln = ln_tmp;
2046 ln_tmp = NULL;
2047 }
2048 }
2049 /* do nothing if static ndp is set */
2050 if ((ln->la_flags & LLE_STATIC)) {
2051 if (flags & LLE_EXCLUSIVE)
2052 LLE_WUNLOCK(ln);
2053 else
2054 LLE_RUNLOCK(ln);
2055 return;
2056 }
2057
2058 olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
2059 if (olladdr && lladdr) {
2060 llchange = bcmp(lladdr, ln->ll_addr,
2061 ifp->if_addrlen);
2062 } else if (!olladdr && lladdr)
2063 llchange = 1;
2064 else
2065 llchange = 0;
2066
2067 /*
2068 * newentry olladdr lladdr llchange (*=record)
2069 * 0 n n -- (1)
2070 * 0 y n -- (2)
2071 * 0 n y y (3) * STALE
2072 * 0 y y n (4) *
2073 * 0 y y y (5) * STALE
2074 * 1 -- n -- (6) NOSTATE(= PASSIVE)
2075 * 1 -- y -- (7) * STALE
2076 */
2077
2078 do_update = 0;
2079 if (is_newentry == 0 && llchange != 0) {
2080 do_update = 1; /* (3,5) */
2081
2082 /*
2083 * Record source link-layer address
2084 * XXX is it dependent to ifp->if_type?
2085 */
2086 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) {
2087 /* Entry was deleted */
2088 LLE_WUNLOCK(ln);
2089 return;
2090 }
2091
2092 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2093
2094 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2095
2096 if (ln->la_hold != NULL)
2097 chain = nd6_grab_holdchain(ln);
2098 }
2099
2100 /* Calculates new router status */
2101 router = nd6_is_router(type, code, is_newentry, olladdr,
2102 lladdr != NULL ? 1 : 0, ln->ln_router);
2103
2104 ln->ln_router = router;
2105 /* Mark non-router redirects with special flag */
2106 if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
2107 ln->la_flags |= LLE_REDIRECT;
2108
2109 if (flags & LLE_EXCLUSIVE)
2110 LLE_WUNLOCK(ln);
2111 else
2112 LLE_RUNLOCK(ln);
2113
2114 if (chain != NULL)
2115 nd6_flush_holdchain(ifp, ln, chain);
2116 if (do_update)
2117 nd6_flush_children_holdchain(ifp, ln);
2118
2119 /*
2120 * When the link-layer address of a router changes, select the
2121 * best router again. In particular, when the neighbor entry is newly
2122 * created, it might affect the selection policy.
2123 * Question: can we restrict the first condition to the "is_newentry"
2124 * case?
2125 * XXX: when we hear an RA from a new router with the link-layer
2126 * address option, defrouter_select_fib() is called twice, since
2127 * defrtrlist_update called the function as well. However, I believe
2128 * we can compromise the overhead, since it only happens the first
2129 * time.
2130 * XXX: although defrouter_select_fib() should not have a bad effect
2131 * for those are not autoconfigured hosts, we explicitly avoid such
2132 * cases for safety.
2133 */
2134 if ((do_update || is_newentry) && router &&
2135 ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) {
2136 /*
2137 * guaranteed recursion
2138 */
2139 defrouter_select_fib(ifp->if_fib);
2140 }
2141 }
2142
2143 static void
nd6_slowtimo(void * arg)2144 nd6_slowtimo(void *arg)
2145 {
2146 struct epoch_tracker et;
2147 CURVNET_SET((struct vnet *) arg);
2148 struct in6_ifextra *nd6if;
2149 struct ifnet *ifp;
2150
2151 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
2152 nd6_slowtimo, curvnet);
2153 NET_EPOCH_ENTER(et);
2154 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2155 if ((nd6if = ifp->if_inet6) == NULL)
2156 continue;
2157 if (nd6if->nd_basereachable && /* already initialized */
2158 (nd6if->nd_recalc_timer -= ND6_SLOWTIMER_INTERVAL) <= 0) {
2159 /*
2160 * Since reachable time rarely changes by router
2161 * advertisements, we SHOULD insure that a new random
2162 * value gets recomputed at least once every few hours.
2163 * (RFC 2461, 6.3.4)
2164 */
2165 nd6if->nd_recalc_timer = V_nd6_recalc_reachtm_interval;
2166 nd6if->nd_reachable =
2167 ND_COMPUTE_RTIME(nd6if->nd_basereachable);
2168 }
2169 }
2170 NET_EPOCH_EXIT(et);
2171 CURVNET_RESTORE();
2172 }
2173
2174 struct mbuf *
nd6_grab_holdchain(struct llentry * ln)2175 nd6_grab_holdchain(struct llentry *ln)
2176 {
2177 struct mbuf *chain;
2178
2179 LLE_WLOCK_ASSERT(ln);
2180
2181 chain = ln->la_hold;
2182 ln->la_hold = NULL;
2183 ln->la_numheld = 0;
2184
2185 if (ln->ln_state == ND6_LLINFO_STALE) {
2186 /*
2187 * The first time we send a packet to a
2188 * neighbor whose entry is STALE, we have
2189 * to change the state to DELAY and a sets
2190 * a timer to expire in DELAY_FIRST_PROBE_TIME
2191 * seconds to ensure do neighbor unreachability
2192 * detection on expiration.
2193 * (RFC 2461 7.3.3)
2194 */
2195 nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
2196 }
2197
2198 return (chain);
2199 }
2200
2201 int
nd6_output_ifp(struct ifnet * ifp,struct ifnet * origifp,struct mbuf * m,struct sockaddr_in6 * dst,struct route * ro)2202 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
2203 struct sockaddr_in6 *dst, struct route *ro)
2204 {
2205 int error;
2206 int ip6len;
2207 struct ip6_hdr *ip6;
2208 struct m_tag *mtag;
2209
2210 #ifdef MAC
2211 mac_netinet6_nd6_send(ifp, m);
2212 #endif
2213
2214 /*
2215 * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
2216 * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
2217 * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
2218 * to be diverted to user space. When re-injected into the kernel,
2219 * send_output() will directly dispatch them to the outgoing interface.
2220 */
2221 if (send_sendso_input_hook != NULL) {
2222 mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
2223 if (mtag != NULL) {
2224 ip6 = mtod(m, struct ip6_hdr *);
2225 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
2226 /* Use the SEND socket */
2227 error = send_sendso_input_hook(m, ifp, SND_OUT,
2228 ip6len);
2229 /* -1 == no app on SEND socket */
2230 if (error == 0 || error != -1)
2231 return (error);
2232 }
2233 }
2234
2235 m_clrprotoflags(m); /* Avoid confusing lower layers. */
2236 IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
2237 mtod(m, struct ip6_hdr *));
2238
2239 if ((ifp->if_flags & IFF_LOOPBACK) == 0)
2240 origifp = ifp;
2241
2242 error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
2243 return (error);
2244 }
2245
2246 /*
2247 * Lookup link headerfor @sa_dst address. Stores found
2248 * data in @desten buffer. Copy of lle ln_flags can be also
2249 * saved in @pflags if @pflags is non-NULL.
2250 *
2251 * If destination LLE does not exists or lle state modification
2252 * is required, call "slow" version.
2253 *
2254 * Return values:
2255 * - 0 on success (address copied to buffer).
2256 * - EWOULDBLOCK (no local error, but address is still unresolved)
2257 * - other errors (alloc failure, etc)
2258 */
2259 int
nd6_resolve(struct ifnet * ifp,int gw_flags,struct mbuf * m,const struct sockaddr * sa_dst,u_char * desten,uint32_t * pflags,struct llentry ** plle)2260 nd6_resolve(struct ifnet *ifp, int gw_flags, struct mbuf *m,
2261 const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
2262 struct llentry **plle)
2263 {
2264 struct llentry *ln = NULL;
2265 const struct sockaddr_in6 *dst6;
2266
2267 NET_EPOCH_ASSERT();
2268
2269 if (pflags != NULL)
2270 *pflags = 0;
2271
2272 dst6 = (const struct sockaddr_in6 *)sa_dst;
2273
2274 /* discard the packet if IPv6 operation is disabled on the interface */
2275 if ((ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED)) {
2276 m_freem(m);
2277 return (ENETDOWN); /* better error? */
2278 }
2279
2280 if (m != NULL && m->m_flags & M_MCAST) {
2281 switch (ifp->if_type) {
2282 case IFT_ETHER:
2283 case IFT_L2VLAN:
2284 case IFT_BRIDGE:
2285 ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
2286 desten);
2287 return (0);
2288 default:
2289 m_freem(m);
2290 return (EAFNOSUPPORT);
2291 }
2292 }
2293
2294 int family = gw_flags >> 16;
2295 int lookup_flags = plle ? LLE_EXCLUSIVE : LLE_UNLOCKED;
2296 ln = nd6_lookup(&dst6->sin6_addr, LLE_SF(family, lookup_flags), ifp);
2297 if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
2298 /* Entry found, let's copy lle info */
2299 bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
2300 if (pflags != NULL)
2301 *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
2302 llentry_provide_feedback(ln);
2303 if (plle) {
2304 LLE_ADDREF(ln);
2305 *plle = ln;
2306 LLE_WUNLOCK(ln);
2307 }
2308 return (0);
2309 } else if (plle && ln)
2310 LLE_WUNLOCK(ln);
2311
2312 return (nd6_resolve_slow(ifp, family, 0, m, dst6, desten, pflags, plle));
2313 }
2314
2315 /*
2316 * Finds or creates a new llentry for @addr and @family.
2317 * Returns wlocked llentry or NULL.
2318 *
2319 *
2320 * Child LLEs.
2321 *
2322 * Do not have their own state machine (gets marked as static)
2323 * settimer bails out for child LLEs just in case.
2324 *
2325 * Locking order: parent lle gets locked first, chen goes the child.
2326 */
2327 static __noinline struct llentry *
nd6_get_llentry(struct ifnet * ifp,const struct in6_addr * addr,int family)2328 nd6_get_llentry(struct ifnet *ifp, const struct in6_addr *addr, int family)
2329 {
2330 struct llentry *child_lle = NULL;
2331 struct llentry *lle, *lle_tmp;
2332
2333 lle = nd6_alloc(addr, 0, ifp);
2334 if (lle != NULL && family != AF_INET6) {
2335 child_lle = nd6_alloc(addr, 0, ifp);
2336 if (child_lle == NULL) {
2337 lltable_free_entry(LLTABLE6(ifp), lle);
2338 return (NULL);
2339 }
2340 child_lle->r_family = family;
2341 child_lle->la_flags |= LLE_CHILD | LLE_STATIC;
2342 child_lle->ln_state = ND6_LLINFO_INCOMPLETE;
2343 }
2344
2345 if (lle == NULL) {
2346 char ip6buf[INET6_ADDRSTRLEN];
2347 log(LOG_DEBUG,
2348 "nd6_get_llentry: can't allocate llinfo for %s "
2349 "(ln=%p)\n",
2350 ip6_sprintf(ip6buf, addr), lle);
2351 return (NULL);
2352 }
2353
2354 LLTABLE_LOCK(LLTABLE6(ifp));
2355 LLE_WLOCK(lle);
2356 /* Prefer any existing entry over newly-created one */
2357 lle_tmp = nd6_lookup(addr, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
2358 if (lle_tmp == NULL)
2359 lltable_link_entry(LLTABLE6(ifp), lle);
2360 else {
2361 lltable_free_entry(LLTABLE6(ifp), lle);
2362 lle = lle_tmp;
2363 }
2364 if (child_lle != NULL) {
2365 /* Check if child lle for the same family exists */
2366 lle_tmp = llentry_lookup_family(lle, child_lle->r_family);
2367 LLE_WLOCK(child_lle);
2368 if (lle_tmp == NULL) {
2369 /* Attach */
2370 lltable_link_child_entry(lle, child_lle);
2371 } else {
2372 /* child lle already exists, free newly-created one */
2373 lltable_free_entry(LLTABLE6(ifp), child_lle);
2374 LLE_WLOCK(lle_tmp);
2375 child_lle = lle_tmp;
2376 }
2377 LLE_WUNLOCK(lle);
2378 lle = child_lle;
2379 }
2380 LLTABLE_UNLOCK(LLTABLE6(ifp));
2381 return (lle);
2382 }
2383
2384 /*
2385 * Do L2 address resolution for @sa_dst address. Stores found
2386 * address in @desten buffer. Copy of lle ln_flags can be also
2387 * saved in @pflags if @pflags is non-NULL.
2388 *
2389 * Heavy version.
2390 * Function assume that destination LLE does not exist,
2391 * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
2392 *
2393 * Set noinline to be dtrace-friendly
2394 */
2395 static __noinline int
nd6_resolve_slow(struct ifnet * ifp,int family,int flags,struct mbuf * m,const struct sockaddr_in6 * dst,u_char * desten,uint32_t * pflags,struct llentry ** plle)2396 nd6_resolve_slow(struct ifnet *ifp, int family, int flags, struct mbuf *m,
2397 const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
2398 struct llentry **plle)
2399 {
2400 struct llentry *lle = NULL;
2401 struct in6_addr *psrc, src;
2402 int send_ns, ll_len;
2403 char *lladdr;
2404
2405 NET_EPOCH_ASSERT();
2406
2407 /*
2408 * Address resolution or Neighbor Unreachability Detection
2409 * for the next hop.
2410 * At this point, the destination of the packet must be a unicast
2411 * or an anycast address(i.e. not a multicast).
2412 */
2413 lle = nd6_lookup(&dst->sin6_addr, LLE_SF(family, LLE_EXCLUSIVE), ifp);
2414 if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp)) {
2415 /*
2416 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2417 * the condition below is not very efficient. But we believe
2418 * it is tolerable, because this should be a rare case.
2419 */
2420 lle = nd6_get_llentry(ifp, &dst->sin6_addr, family);
2421 }
2422
2423 if (lle == NULL) {
2424 m_freem(m);
2425 return (ENOBUFS);
2426 }
2427
2428 LLE_WLOCK_ASSERT(lle);
2429
2430 /*
2431 * The first time we send a packet to a neighbor whose entry is
2432 * STALE, we have to change the state to DELAY and a sets a timer to
2433 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2434 * neighbor unreachability detection on expiration.
2435 * (RFC 2461 7.3.3)
2436 */
2437 if ((!(lle->la_flags & LLE_CHILD)) && (lle->ln_state == ND6_LLINFO_STALE))
2438 nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
2439
2440 /*
2441 * If the neighbor cache entry has a state other than INCOMPLETE
2442 * (i.e. its link-layer address is already resolved), just
2443 * send the packet.
2444 */
2445 if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
2446 if (flags & LLE_ADDRONLY) {
2447 lladdr = lle->ll_addr;
2448 ll_len = ifp->if_addrlen;
2449 } else {
2450 lladdr = lle->r_linkdata;
2451 ll_len = lle->r_hdrlen;
2452 }
2453 bcopy(lladdr, desten, ll_len);
2454 if (pflags != NULL)
2455 *pflags = lle->la_flags;
2456 if (plle) {
2457 LLE_ADDREF(lle);
2458 *plle = lle;
2459 }
2460 LLE_WUNLOCK(lle);
2461 return (0);
2462 }
2463
2464 /*
2465 * There is a neighbor cache entry, but no ethernet address
2466 * response yet. Append this latest packet to the end of the
2467 * packet queue in the mbuf. When it exceeds nd6_maxqueuelen,
2468 * the oldest packet in the queue will be removed.
2469 */
2470 if (m != NULL) {
2471 size_t dropped;
2472
2473 dropped = lltable_append_entry_queue(lle, m, V_nd6_maxqueuelen);
2474 ICMP6STAT_ADD(icp6s_dropped, dropped);
2475 }
2476
2477 /*
2478 * If there has been no NS for the neighbor after entering the
2479 * INCOMPLETE state, send the first solicitation.
2480 * Note that for newly-created lle la_asked will be 0,
2481 * so we will transition from ND6_LLINFO_NOSTATE to
2482 * ND6_LLINFO_INCOMPLETE state here.
2483 */
2484 psrc = NULL;
2485 send_ns = 0;
2486
2487 /* If we have child lle, switch to the parent to send NS */
2488 if (lle->la_flags & LLE_CHILD) {
2489 struct llentry *lle_parent = lle->lle_parent;
2490 LLE_WUNLOCK(lle);
2491 lle = lle_parent;
2492 LLE_WLOCK(lle);
2493 }
2494 if (lle->la_asked == 0) {
2495 lle->la_asked++;
2496 send_ns = 1;
2497 psrc = nd6_llinfo_get_holdsrc(lle, &src);
2498
2499 nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
2500 }
2501 LLE_WUNLOCK(lle);
2502 if (send_ns != 0)
2503 nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
2504
2505 return (EWOULDBLOCK);
2506 }
2507
2508 /*
2509 * Do L2 address resolution for @sa_dst address. Stores found
2510 * address in @desten buffer. Copy of lle ln_flags can be also
2511 * saved in @pflags if @pflags is non-NULL.
2512 *
2513 * Return values:
2514 * - 0 on success (address copied to buffer).
2515 * - EWOULDBLOCK (no local error, but address is still unresolved)
2516 * - other errors (alloc failure, etc)
2517 */
2518 int
nd6_resolve_addr(struct ifnet * ifp,int flags,const struct sockaddr * dst,char * desten,uint32_t * pflags)2519 nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
2520 char *desten, uint32_t *pflags)
2521 {
2522 int error;
2523
2524 flags |= LLE_ADDRONLY;
2525 error = nd6_resolve_slow(ifp, AF_INET6, flags, NULL,
2526 (const struct sockaddr_in6 *)dst, desten, pflags, NULL);
2527 return (error);
2528 }
2529
2530 int
nd6_flush_holdchain(struct ifnet * ifp,struct llentry * lle,struct mbuf * chain)2531 nd6_flush_holdchain(struct ifnet *ifp, struct llentry *lle, struct mbuf *chain)
2532 {
2533 struct mbuf *m, *m_head;
2534 struct sockaddr_in6 dst6;
2535 int error = 0;
2536
2537 NET_EPOCH_ASSERT();
2538
2539 struct route_in6 ro = {
2540 .ro_prepend = lle->r_linkdata,
2541 .ro_plen = lle->r_hdrlen,
2542 };
2543
2544 lltable_fill_sa_entry(lle, (struct sockaddr *)&dst6);
2545 m_head = chain;
2546
2547 while (m_head) {
2548 m = m_head;
2549 m_head = m_head->m_nextpkt;
2550 m->m_nextpkt = NULL;
2551 error = nd6_output_ifp(ifp, ifp, m, &dst6, (struct route *)&ro);
2552 }
2553
2554 /*
2555 * XXX
2556 * note that intermediate errors are blindly ignored
2557 */
2558 return (error);
2559 }
2560
2561 __noinline void
nd6_flush_children_holdchain(struct ifnet * ifp,struct llentry * lle)2562 nd6_flush_children_holdchain(struct ifnet *ifp, struct llentry *lle)
2563 {
2564 struct llentry *child_lle;
2565 struct mbuf *chain;
2566
2567 NET_EPOCH_ASSERT();
2568
2569 CK_SLIST_FOREACH(child_lle, &lle->lle_children, lle_child_next) {
2570 LLE_WLOCK(child_lle);
2571 chain = nd6_grab_holdchain(child_lle);
2572 LLE_WUNLOCK(child_lle);
2573 nd6_flush_holdchain(ifp, child_lle, chain);
2574 }
2575 }
2576
2577 static int
nd6_need_cache(struct ifnet * ifp)2578 nd6_need_cache(struct ifnet *ifp)
2579 {
2580 /*
2581 * XXX: we currently do not make neighbor cache on any interface
2582 * other than Ethernet and GIF.
2583 *
2584 * RFC2893 says:
2585 * - unidirectional tunnels needs no ND
2586 */
2587 switch (ifp->if_type) {
2588 case IFT_ETHER:
2589 case IFT_IEEE1394:
2590 case IFT_L2VLAN:
2591 case IFT_INFINIBAND:
2592 case IFT_BRIDGE:
2593 case IFT_PROPVIRTUAL:
2594 return (1);
2595 default:
2596 return (0);
2597 }
2598 }
2599
2600 /*
2601 * Add pernament ND6 link-layer record for given
2602 * interface address.
2603 *
2604 * Very similar to IPv4 arp_ifinit(), but:
2605 * 1) IPv6 DAD is performed in different place
2606 * 2) It is called by IPv6 protocol stack in contrast to
2607 * arp_ifinit() which is typically called in SIOCSIFADDR
2608 * driver ioctl handler.
2609 *
2610 */
2611 int
nd6_add_ifa_lle(struct in6_ifaddr * ia)2612 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2613 {
2614 struct ifnet *ifp;
2615 struct llentry *ln, *ln_tmp;
2616 struct sockaddr *dst;
2617
2618 ifp = ia->ia_ifa.ifa_ifp;
2619 if (nd6_need_cache(ifp) == 0)
2620 return (0);
2621
2622 dst = (struct sockaddr *)&ia->ia_addr;
2623 ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
2624 if (ln == NULL)
2625 return (ENOBUFS);
2626
2627 LLTABLE_LOCK(LLTABLE6(ifp));
2628 LLE_WLOCK(ln);
2629 /* Unlink any entry if exists */
2630 ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_SF(AF_INET6, LLE_EXCLUSIVE), dst);
2631 if (ln_tmp != NULL)
2632 lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
2633 lltable_link_entry(LLTABLE6(ifp), ln);
2634 LLTABLE_UNLOCK(LLTABLE6(ifp));
2635
2636 if (ln_tmp != NULL)
2637 EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
2638 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2639
2640 LLE_WUNLOCK(ln);
2641 if (ln_tmp != NULL)
2642 llentry_free(ln_tmp);
2643
2644 return (0);
2645 }
2646
2647 /*
2648 * Removes either all lle entries for given @ia, or lle
2649 * corresponding to @ia address.
2650 */
2651 void
nd6_rem_ifa_lle(struct in6_ifaddr * ia,int all)2652 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
2653 {
2654 struct sockaddr_in6 mask, addr;
2655 struct sockaddr *saddr, *smask;
2656 struct ifnet *ifp;
2657
2658 ifp = ia->ia_ifa.ifa_ifp;
2659 memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2660 memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2661 saddr = (struct sockaddr *)&addr;
2662 smask = (struct sockaddr *)&mask;
2663
2664 if (all != 0)
2665 lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
2666 else
2667 lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
2668 }
2669
2670 static int
nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)2671 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2672 {
2673 struct in6_prefix p;
2674 struct sockaddr_in6 s6;
2675 struct nd_prefix *pr;
2676 struct nd_pfxrouter *pfr;
2677 time_t maxexpire;
2678 int error;
2679 char ip6buf[INET6_ADDRSTRLEN];
2680
2681 if (req->newptr)
2682 return (EPERM);
2683
2684 error = sysctl_wire_old_buffer(req, 0);
2685 if (error != 0)
2686 return (error);
2687
2688 bzero(&p, sizeof(p));
2689 p.origin = PR_ORIG_RA;
2690 bzero(&s6, sizeof(s6));
2691 s6.sin6_family = AF_INET6;
2692 s6.sin6_len = sizeof(s6);
2693
2694 ND6_RLOCK();
2695 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
2696 p.prefix = pr->ndpr_prefix;
2697 if (sa6_recoverscope(&p.prefix)) {
2698 log(LOG_ERR, "scope error in prefix list (%s)\n",
2699 ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
2700 /* XXX: press on... */
2701 }
2702 p.raflags = pr->ndpr_raf;
2703 p.prefixlen = pr->ndpr_plen;
2704 p.vltime = pr->ndpr_vltime;
2705 p.pltime = pr->ndpr_pltime;
2706 p.if_index = pr->ndpr_ifp->if_index;
2707 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2708 p.expire = 0;
2709 else {
2710 /* XXX: we assume time_t is signed. */
2711 maxexpire = (-1) &
2712 ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
2713 if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
2714 p.expire = pr->ndpr_lastupdate +
2715 pr->ndpr_vltime +
2716 (time_second - time_uptime);
2717 else
2718 p.expire = maxexpire;
2719 }
2720 p.refcnt = pr->ndpr_addrcnt;
2721 p.flags = pr->ndpr_stateflags;
2722 p.advrtrs = 0;
2723 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2724 p.advrtrs++;
2725 error = SYSCTL_OUT(req, &p, sizeof(p));
2726 if (error != 0)
2727 break;
2728 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2729 s6.sin6_addr = pfr->router->rtaddr;
2730 if (sa6_recoverscope(&s6))
2731 log(LOG_ERR,
2732 "scope error in prefix list (%s)\n",
2733 ip6_sprintf(ip6buf, &pfr->router->rtaddr));
2734 error = SYSCTL_OUT(req, &s6, sizeof(s6));
2735 if (error != 0)
2736 goto out;
2737 }
2738 }
2739 out:
2740 ND6_RUNLOCK();
2741 return (error);
2742 }
2743 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2744 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
2745 NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
2746 "NDP prefix list");
2747 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
2748 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
2749 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
2750 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
2751