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 #include "opt_route.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/eventhandler.h>
41 #include <sys/callout.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/mbuf.h>
45 #include <sys/mutex.h>
46 #include <sys/socket.h>
47 #include <sys/sockio.h>
48 #include <sys/time.h>
49 #include <sys/kernel.h>
50 #include <sys/protosw.h>
51 #include <sys/errno.h>
52 #include <sys/syslog.h>
53 #include <sys/rwlock.h>
54 #include <sys/queue.h>
55 #include <sys/sdt.h>
56 #include <sys/sysctl.h>
57
58 #include <net/if.h>
59 #include <net/if_var.h>
60 #include <net/if_dl.h>
61 #include <net/if_private.h>
62 #include <net/if_types.h>
63 #include <net/route.h>
64 #include <net/route/route_ctl.h>
65 #include <net/route/nhop.h>
66 #include <net/vnet.h>
67
68 #include <netinet/in.h>
69 #include <netinet/in_kdtrace.h>
70 #include <net/if_llatbl.h>
71 #include <netinet/if_ether.h>
72 #include <netinet6/in6_fib.h>
73 #include <netinet6/in6_var.h>
74 #include <netinet/ip6.h>
75 #include <netinet6/ip6_var.h>
76 #include <netinet6/scope6_var.h>
77 #include <netinet6/nd6.h>
78 #include <netinet6/in6_ifattach.h>
79 #include <netinet/icmp6.h>
80 #include <netinet6/send.h>
81
82 #include <sys/limits.h>
83
84 #include <security/mac/mac_framework.h>
85
86 #define ND6_PREFIX_WITH_ROUTER(pr) !LIST_EMPTY(&(pr)->ndpr_advrtrs)
87
88 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
89 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
90
91 VNET_DEFINE_STATIC(int, nd6_prune) = 1;
92 #define V_nd6_prune VNET(nd6_prune)
93 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_PRUNE, nd6_prune,
94 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_prune), 0,
95 "Frequency in seconds of checks for expired prefixes and routers");
96
97 VNET_DEFINE_STATIC(int, nd6_delay) = 5;
98 #define V_nd6_delay VNET(nd6_delay)
99 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DELAY, nd6_delay,
100 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_delay), 0,
101 "Delay in seconds before probing for reachability");
102
103 VNET_DEFINE_STATIC(int, nd6_umaxtries) = 3;
104 #define V_nd6_umaxtries VNET(nd6_umaxtries)
105 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_UMAXTRIES, nd6_umaxtries,
106 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_umaxtries), 0,
107 "Number of ICMPv6 NS messages sent during reachability detection");
108
109 VNET_DEFINE(int, nd6_mmaxtries) = 3;
110 #define V_nd6_mmaxtries VNET(nd6_mmaxtries)
111 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MMAXTRIES, nd6_mmaxtries,
112 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_mmaxtries), 0,
113 "Number of ICMPv6 NS messages sent during address resolution");
114
115 VNET_DEFINE_STATIC(int, nd6_gctimer) = (60 * 60 * 24); /* 1 day: garbage
116 * collection timer */
117 #define V_nd6_gctimer VNET(nd6_gctimer)
118
119 /* preventing too many loops in ND option parsing */
120 VNET_DEFINE_STATIC(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
121
122 VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 16; /* max pkts cached in unresolved
123 * ND entries */
124 #define V_nd6_maxndopt VNET(nd6_maxndopt)
125 #define V_nd6_maxqueuelen VNET(nd6_maxqueuelen)
126
127 #ifdef ND6_DEBUG
128 VNET_DEFINE(int, nd6_debug) = 1;
129 #else
130 VNET_DEFINE(int, nd6_debug) = 0;
131 #endif
132 #define V_nd6_debug VNET(nd6_debug)
133 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DEBUG, nd6_debug,
134 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_debug), 0,
135 "Log NDP debug messages");
136
137 static eventhandler_tag lle_event_eh, iflladdr_event_eh, ifnet_link_event_eh;
138
139 VNET_DEFINE(struct nd_prhead, nd_prefix);
140 VNET_DEFINE(struct rwlock, nd6_lock);
141 VNET_DEFINE(uint64_t, nd6_list_genid);
142 VNET_DEFINE(struct mtx, nd6_onlink_mtx);
143
144 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
145 #define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
146
147 int (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
148
149 static bool nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
150 struct ifnet *);
151 static void nd6_slowtimo(void *);
152 static int regen_tmpaddr(struct in6_ifaddr *);
153 static void nd6_free(struct llentry **, int);
154 static void nd6_free_redirect(const struct llentry *);
155 static void nd6_llinfo_timer(void *);
156 static void nd6_llinfo_settimer_locked(struct llentry *, long);
157 static int nd6_resolve_slow(struct ifnet *, int, int, struct mbuf *,
158 const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
159 static int nd6_need_cache(struct ifnet *);
160
161 VNET_DEFINE_STATIC(struct callout, nd6_slowtimo_ch);
162 #define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch)
163
164 VNET_DEFINE_STATIC(struct callout, nd6_timer_ch);
165 #define V_nd6_timer_ch VNET(nd6_timer_ch)
166
167 static void
nd6_lle_event(void * arg __unused,struct llentry * lle,int evt)168 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
169 {
170 struct rt_addrinfo rtinfo;
171 struct sockaddr_in6 dst;
172 struct sockaddr_dl gw;
173 struct ifnet *ifp;
174 int type;
175 int fibnum;
176
177 LLE_WLOCK_ASSERT(lle);
178
179 if (lltable_get_af(lle->lle_tbl) != AF_INET6)
180 return;
181
182 switch (evt) {
183 case LLENTRY_RESOLVED:
184 type = RTM_ADD;
185 KASSERT(lle->la_flags & LLE_VALID,
186 ("%s: %p resolved but not valid?", __func__, lle));
187 break;
188 case LLENTRY_EXPIRED:
189 type = RTM_DELETE;
190 break;
191 default:
192 return;
193 }
194
195 ifp = lltable_get_ifp(lle->lle_tbl);
196
197 bzero(&dst, sizeof(dst));
198 bzero(&gw, sizeof(gw));
199 bzero(&rtinfo, sizeof(rtinfo));
200 lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
201 dst.sin6_scope_id = in6_getscopezone(ifp,
202 in6_addrscope(&dst.sin6_addr));
203 gw.sdl_len = sizeof(struct sockaddr_dl);
204 gw.sdl_family = AF_LINK;
205 gw.sdl_alen = ifp->if_addrlen;
206 gw.sdl_index = ifp->if_index;
207 gw.sdl_type = ifp->if_type;
208 if (evt == LLENTRY_RESOLVED)
209 bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
210 rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
211 rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
212 rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
213 fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib;
214 rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
215 type == RTM_ADD ? RTF_UP: 0), 0, fibnum);
216 }
217
218 /*
219 * A handler for interface link layer address change event.
220 */
221 static void
nd6_iflladdr(void * arg __unused,struct ifnet * ifp)222 nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
223 {
224 struct ifaddr *ifa;
225 struct epoch_tracker et;
226
227 /* XXXGL: ??? */
228 if (ifp->if_inet6 == NULL)
229 return;
230
231 lltable_update_ifaddr(LLTABLE6(ifp));
232
233 if ((ifp->if_flags & IFF_UP) == 0)
234 return;
235
236 /*
237 * Sends gratuitous NAs for each ifaddr to notify other
238 * nodes about the address change.
239 */
240 NET_EPOCH_ENTER(et);
241 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
242 if (ifa->ifa_addr->sa_family == AF_INET6 &&
243 ! IN6_IS_ADDR_MULTICAST(IFA_IN6(ifa)))
244 nd6_grand_start(ifa, ND6_QUEUE_FLAG_LLADDR);
245 }
246 NET_EPOCH_EXIT(et);
247 }
248
249 void
nd6_init(void)250 nd6_init(void)
251 {
252
253 mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF);
254 rw_init(&V_nd6_lock, "nd6 list");
255
256 LIST_INIT(&V_nd_prefix);
257 nd6_defrouter_init();
258
259 /* Start timers. */
260 callout_init(&V_nd6_slowtimo_ch, 1);
261 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
262 nd6_slowtimo, curvnet);
263
264 callout_init(&V_nd6_timer_ch, 1);
265 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
266
267 nd6_dad_init();
268 if (IS_DEFAULT_VNET(curvnet)) {
269 lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
270 NULL, EVENTHANDLER_PRI_ANY);
271 iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
272 nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
273 ifnet_link_event_eh = EVENTHANDLER_REGISTER(ifnet_link_event,
274 nd6_ifnet_link_event, NULL, EVENTHANDLER_PRI_ANY);
275 }
276 }
277
278 #ifdef VIMAGE
279 void
nd6_destroy(void)280 nd6_destroy(void)
281 {
282
283 callout_drain(&V_nd6_slowtimo_ch);
284 callout_drain(&V_nd6_timer_ch);
285 if (IS_DEFAULT_VNET(curvnet)) {
286 EVENTHANDLER_DEREGISTER(ifnet_link_event, ifnet_link_event_eh);
287 EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
288 EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
289 }
290 rw_destroy(&V_nd6_lock);
291 mtx_destroy(&V_nd6_onlink_mtx);
292 }
293 #endif
294
295 void
nd6_ifattach(struct ifnet * ifp)296 nd6_ifattach(struct ifnet *ifp)
297 {
298 struct in6_ifextra *nd = ifp->if_inet6;
299
300 nd->nd_linkmtu = 0;
301 nd->nd_maxmtu = ifp->if_mtu;
302 nd->nd_basereachable = REACHABLE_TIME;
303 nd->nd_reachable = ND_COMPUTE_RTIME(nd->nd_basereachable);
304 nd->nd_retrans = RETRANS_TIMER;
305 nd->nd_recalc_timer = 0;
306 nd->nd_dad_failures = 0;
307 nd->nd_curhoplimit = IPV6_DEFHLIM;
308
309 nd->nd_flags = ND6_IFF_PERFORMNUD;
310
311 /* Set IPv6 disabled on all interfaces but loopback by default. */
312 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
313 nd->nd_flags |= ND6_IFF_IFDISABLED;
314 if (V_ip6_no_radr)
315 nd->nd_flags |= ND6_IFF_NO_RADR;
316 if (V_ip6_use_stableaddr)
317 nd->nd_flags |= ND6_IFF_STABLEADDR;
318 }
319
320 /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
321 * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
322 * default regardless of the V_ip6_auto_linklocal configuration to
323 * give a reasonable default behavior.
324 */
325 if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE &&
326 ifp->if_type != IFT_WIREGUARD) || (ifp->if_flags & IFF_LOOPBACK))
327 nd->nd_flags |= ND6_IFF_AUTO_LINKLOCAL;
328 /*
329 * A loopback interface does not need to accept RTADV.
330 * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
331 * default regardless of the V_ip6_accept_rtadv configuration to
332 * prevent the interface from accepting RA messages arrived
333 * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
334 */
335 if (V_ip6_accept_rtadv &&
336 !(ifp->if_flags & IFF_LOOPBACK) &&
337 (ifp->if_type != IFT_BRIDGE)) {
338 nd->nd_flags |= ND6_IFF_ACCEPT_RTADV;
339 /* If we globally accept rtadv, assume IPv6 on. */
340 nd->nd_flags &= ~ND6_IFF_IFDISABLED;
341 }
342
343 /* nd6 queue initialization */
344 TAILQ_INIT(&nd->nd_queue);
345 }
346
347 void
nd6_ifdetach(struct ifnet * ifp)348 nd6_ifdetach(struct ifnet *ifp)
349 {
350 struct epoch_tracker et;
351 struct ifaddr *ifa, *next;
352
353 NET_EPOCH_ENTER(et);
354 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
355 if (ifa->ifa_addr->sa_family != AF_INET6)
356 continue;
357
358 /* make sure there are no queued ND6 */
359 nd6_queue_stop(ifa);
360
361 /* stop DAD processing */
362 nd6_dad_stop(ifa);
363 }
364 NET_EPOCH_EXIT(et);
365 }
366
367 /*
368 * Reset ND level link MTU. This function is called when the physical MTU
369 * changes, which means we might have to adjust the ND level MTU.
370 * XXX todo: do not maintain copy of ifp->if_mtu in if_inet6->nd_maxmtu.
371 */
372 void
nd6_setmtu(struct ifnet * ifp)373 nd6_setmtu(struct ifnet *ifp)
374 {
375 struct in6_ifextra *ndi = ifp->if_inet6;
376 uint32_t omaxmtu;
377
378 /* XXXGL: safety against IFT_PFSYNC & IFT_PFLOG */
379 if (ndi == NULL)
380 return;
381
382 omaxmtu = ndi->nd_maxmtu;
383 ndi->nd_maxmtu = ifp->if_mtu;
384
385 /*
386 * Decreasing the interface MTU under IPV6 minimum MTU may cause
387 * undesirable situation. We thus notify the operator of the change
388 * explicitly. The check for omaxmtu is necessary to restrict the
389 * log to the case of changing the MTU, not initializing it.
390 */
391 if (omaxmtu >= IPV6_MMTU && ndi->nd_maxmtu < IPV6_MMTU) {
392 log(LOG_NOTICE, "%s: "
393 "new link MTU on %s (%lu) is too small for IPv6\n",
394 __func__, if_name(ifp), (unsigned long)ndi->nd_maxmtu);
395 }
396 }
397
398 void
nd6_option_init(void * opt,int icmp6len,union nd_opts * ndopts)399 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
400 {
401
402 bzero(ndopts, sizeof(*ndopts));
403 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
404 ndopts->nd_opts_last
405 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
406
407 if (icmp6len == 0) {
408 ndopts->nd_opts_done = 1;
409 ndopts->nd_opts_search = NULL;
410 }
411 }
412
413 /*
414 * Take one ND option.
415 */
416 struct nd_opt_hdr *
nd6_option(union nd_opts * ndopts)417 nd6_option(union nd_opts *ndopts)
418 {
419 struct nd_opt_hdr *nd_opt;
420 int olen;
421
422 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
423 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
424 __func__));
425 if (ndopts->nd_opts_search == NULL)
426 return NULL;
427 if (ndopts->nd_opts_done)
428 return NULL;
429
430 nd_opt = ndopts->nd_opts_search;
431
432 /* make sure nd_opt_len is inside the buffer */
433 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
434 bzero(ndopts, sizeof(*ndopts));
435 return NULL;
436 }
437
438 olen = nd_opt->nd_opt_len << 3;
439 /*
440 * RFC 4861 section 6.1.2: All included options
441 * must have a length that is greater than zero.
442 */
443 if (olen == 0) {
444 bzero(ndopts, sizeof(*ndopts));
445 return NULL;
446 }
447
448 ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
449 if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
450 /* option overruns the end of buffer, invalid */
451 bzero(ndopts, sizeof(*ndopts));
452 return NULL;
453 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
454 /* reached the end of options chain */
455 ndopts->nd_opts_done = 1;
456 ndopts->nd_opts_search = NULL;
457 }
458 return nd_opt;
459 }
460
461 /*
462 * Parse multiple ND options.
463 * This function is much easier to use, for ND routines that do not need
464 * multiple options of the same type.
465 */
466 int
nd6_options(union nd_opts * ndopts)467 nd6_options(union nd_opts *ndopts)
468 {
469 struct nd_opt_hdr *nd_opt;
470 int i = 0;
471
472 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
473 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
474 __func__));
475 if (ndopts->nd_opts_search == NULL)
476 return 0;
477
478 while (1) {
479 nd_opt = nd6_option(ndopts);
480 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
481 /*
482 * Message validation requires that all included
483 * options have a length that is greater than zero.
484 */
485 ICMP6STAT_INC(icp6s_nd_badopt);
486 bzero(ndopts, sizeof(*ndopts));
487 return -1;
488 }
489
490 if (nd_opt == NULL)
491 goto skip1;
492
493 switch (nd_opt->nd_opt_type) {
494 case ND_OPT_SOURCE_LINKADDR:
495 case ND_OPT_TARGET_LINKADDR:
496 case ND_OPT_MTU:
497 case ND_OPT_REDIRECTED_HEADER:
498 case ND_OPT_NONCE:
499 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
500 nd6log((LOG_INFO,
501 "duplicated ND6 option found (type=%d)\n",
502 nd_opt->nd_opt_type));
503 /* XXX bark? */
504 } else {
505 ndopts->nd_opt_array[nd_opt->nd_opt_type]
506 = nd_opt;
507 }
508 break;
509 case ND_OPT_PREFIX_INFORMATION:
510 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
511 ndopts->nd_opt_array[nd_opt->nd_opt_type]
512 = nd_opt;
513 }
514 ndopts->nd_opts_pi_end =
515 (struct nd_opt_prefix_info *)nd_opt;
516 break;
517 /* What about ND_OPT_ROUTE_INFO? RFC 4191 */
518 case ND_OPT_RDNSS: /* RFC 6106 */
519 case ND_OPT_DNSSL: /* RFC 6106 */
520 /*
521 * Silently ignore options we know and do not care about
522 * in the kernel.
523 */
524 break;
525 default:
526 /*
527 * Unknown options must be silently ignored,
528 * to accommodate future extension to the protocol.
529 */
530 nd6log((LOG_DEBUG,
531 "nd6_options: unsupported option %d - "
532 "option ignored\n", nd_opt->nd_opt_type));
533 }
534
535 skip1:
536 i++;
537 if (i > V_nd6_maxndopt) {
538 ICMP6STAT_INC(icp6s_nd_toomanyopt);
539 nd6log((LOG_INFO, "too many loop in nd opt\n"));
540 break;
541 }
542
543 if (ndopts->nd_opts_done)
544 break;
545 }
546
547 return 0;
548 }
549
550 /*
551 * ND6 timer routine to handle ND6 entries
552 */
553 static void
nd6_llinfo_settimer_locked(struct llentry * ln,long tick)554 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
555 {
556 int canceled;
557
558 LLE_WLOCK_ASSERT(ln);
559
560 /* Do not schedule timers for child LLEs. */
561 if (ln->la_flags & LLE_CHILD)
562 return;
563
564 if (tick < 0) {
565 ln->la_expire = 0;
566 ln->ln_ntick = 0;
567 canceled = callout_stop(&ln->lle_timer);
568 } else {
569 ln->la_expire = time_uptime + tick / hz;
570 LLE_ADDREF(ln);
571 if (tick > INT_MAX) {
572 ln->ln_ntick = tick - INT_MAX;
573 canceled = callout_reset(&ln->lle_timer, INT_MAX,
574 nd6_llinfo_timer, ln);
575 } else {
576 ln->ln_ntick = 0;
577 canceled = callout_reset(&ln->lle_timer, tick,
578 nd6_llinfo_timer, ln);
579 }
580 }
581 if (canceled > 0)
582 LLE_REMREF(ln);
583 }
584
585 /*
586 * Gets source address of the first packet in hold queue
587 * and stores it in @src.
588 * Returns pointer to @src (if hold queue is not empty) or NULL.
589 *
590 * Set noinline to be dtrace-friendly
591 */
592 static __noinline struct in6_addr *
nd6_llinfo_get_holdsrc(struct llentry * ln,struct in6_addr * src)593 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
594 {
595 struct ip6_hdr hdr;
596 struct mbuf *m;
597
598 if (ln->la_hold == NULL)
599 return (NULL);
600
601 /*
602 * assume every packet in la_hold has the same IP header
603 */
604 m = ln->la_hold;
605 if (sizeof(hdr) > m->m_len)
606 return (NULL);
607
608 m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
609 *src = hdr.ip6_src;
610
611 return (src);
612 }
613
614 /*
615 * Checks if we need to switch from STALE state.
616 *
617 * RFC 4861 requires switching from STALE to DELAY state
618 * on first packet matching entry, waiting V_nd6_delay and
619 * transition to PROBE state (if upper layer confirmation was
620 * not received).
621 *
622 * This code performs a bit differently:
623 * On packet hit we don't change state (but desired state
624 * can be guessed by control plane). However, after V_nd6_delay
625 * seconds code will transition to PROBE state (so DELAY state
626 * is kinda skipped in most situations).
627 *
628 * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
629 * we perform the following upon entering STALE state:
630 *
631 * 1) Arm timer to run each V_nd6_delay seconds to make sure that
632 * if packet was transmitted at the start of given interval, we
633 * would be able to switch to PROBE state in V_nd6_delay seconds
634 * as user expects.
635 *
636 * 2) Reschedule timer until original V_nd6_gctimer expires keeping
637 * lle in STALE state (remaining timer value stored in lle_remtime).
638 *
639 * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
640 * seconds ago.
641 *
642 * Returns non-zero value if the entry is still STALE (storing
643 * the next timer interval in @pdelay).
644 *
645 * Returns zero value if original timer expired or we need to switch to
646 * PROBE (store that in @do_switch variable).
647 */
648 static int
nd6_is_stale(struct llentry * lle,long * pdelay,int * do_switch)649 nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
650 {
651 int nd_delay, nd_gctimer;
652 time_t lle_hittime;
653 long delay;
654
655 *do_switch = 0;
656 nd_gctimer = V_nd6_gctimer;
657 nd_delay = V_nd6_delay;
658
659 lle_hittime = llentry_get_hittime(lle);
660
661 if (lle_hittime == 0) {
662 /*
663 * Datapath feedback has been requested upon entering
664 * STALE state. No packets has been passed using this lle.
665 * Ask for the timer reschedule and keep STALE state.
666 */
667 delay = (long)(MIN(nd_gctimer, nd_delay));
668 delay *= hz;
669 if (lle->lle_remtime > delay)
670 lle->lle_remtime -= delay;
671 else {
672 delay = lle->lle_remtime;
673 lle->lle_remtime = 0;
674 }
675
676 if (delay == 0) {
677 /*
678 * The original ng6_gctime timeout ended,
679 * no more rescheduling.
680 */
681 return (0);
682 }
683
684 *pdelay = delay;
685 return (1);
686 }
687
688 /*
689 * Packet received. Verify timestamp
690 */
691 delay = (long)(time_uptime - lle_hittime);
692 if (delay < nd_delay) {
693 /*
694 * V_nd6_delay still not passed since the first
695 * hit in STALE state.
696 * Reschedule timer and return.
697 */
698 *pdelay = (long)(nd_delay - delay) * hz;
699 return (1);
700 }
701
702 /* Request switching to probe */
703 *do_switch = 1;
704 return (0);
705 }
706
707 /*
708 * Switch @lle state to new state optionally arming timers.
709 *
710 * Set noinline to be dtrace-friendly
711 */
712 __noinline void
nd6_llinfo_setstate(struct llentry * lle,int newstate)713 nd6_llinfo_setstate(struct llentry *lle, int newstate)
714 {
715 struct ifnet *ifp;
716 int nd_gctimer, nd_delay;
717 long delay, remtime;
718
719 delay = 0;
720 remtime = 0;
721
722 switch (newstate) {
723 case ND6_LLINFO_INCOMPLETE:
724 ifp = lle->lle_tbl->llt_ifp;
725 delay = (long)ifp->if_inet6->nd_retrans * hz / 1000;
726 break;
727 case ND6_LLINFO_REACHABLE:
728 if (!ND6_LLINFO_PERMANENT(lle)) {
729 ifp = lle->lle_tbl->llt_ifp;
730 delay = (long)ifp->if_inet6->nd_reachable * hz;
731 }
732 break;
733 case ND6_LLINFO_STALE:
734
735 llentry_request_feedback(lle);
736 nd_delay = V_nd6_delay;
737 nd_gctimer = V_nd6_gctimer;
738
739 delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
740 remtime = (long)nd_gctimer * hz - delay;
741 break;
742 case ND6_LLINFO_DELAY:
743 lle->la_asked = 0;
744 delay = (long)V_nd6_delay * hz;
745 break;
746 }
747
748 if (delay > 0)
749 nd6_llinfo_settimer_locked(lle, delay);
750
751 lle->lle_remtime = remtime;
752 lle->ln_state = newstate;
753 }
754
755 /*
756 * Timer-dependent part of nd state machine.
757 *
758 * Set noinline to be dtrace-friendly
759 */
760 static __noinline void
nd6_llinfo_timer(void * arg)761 nd6_llinfo_timer(void *arg)
762 {
763 struct epoch_tracker et;
764 struct llentry *ln;
765 struct in6_addr *dst, *pdst, *psrc, src;
766 struct ifnet *ifp;
767 struct in6_ifextra *ndi;
768 int do_switch, send_ns;
769 long delay;
770
771 KASSERT(arg != NULL, ("%s: arg NULL", __func__));
772 ln = (struct llentry *)arg;
773 ifp = lltable_get_ifp(ln->lle_tbl);
774 CURVNET_SET(ifp->if_vnet);
775
776 ND6_RLOCK();
777 LLE_WLOCK(ln);
778 if (callout_pending(&ln->lle_timer)) {
779 /*
780 * Here we are a bit odd here in the treatment of
781 * active/pending. If the pending bit is set, it got
782 * rescheduled before I ran. The active
783 * bit we ignore, since if it was stopped
784 * in ll_tablefree() and was currently running
785 * it would have return 0 so the code would
786 * not have deleted it since the callout could
787 * not be stopped so we want to go through
788 * with the delete here now. If the callout
789 * was restarted, the pending bit will be back on and
790 * we just want to bail since the callout_reset would
791 * return 1 and our reference would have been removed
792 * by nd6_llinfo_settimer_locked above since canceled
793 * would have been 1.
794 */
795 LLE_WUNLOCK(ln);
796 ND6_RUNLOCK();
797 CURVNET_RESTORE();
798 return;
799 }
800 NET_EPOCH_ENTER(et);
801 ndi = ifp->if_inet6;
802 send_ns = 0;
803 dst = &ln->r_l3addr.addr6;
804 pdst = dst;
805
806 if (ln->ln_ntick > 0) {
807 if (ln->ln_ntick > INT_MAX) {
808 ln->ln_ntick -= INT_MAX;
809 nd6_llinfo_settimer_locked(ln, INT_MAX);
810 } else {
811 ln->ln_ntick = 0;
812 nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
813 }
814 goto done;
815 }
816
817 if (ln->la_flags & LLE_STATIC) {
818 goto done;
819 }
820
821 if (ln->la_flags & LLE_DELETED) {
822 nd6_free(&ln, 0);
823 goto done;
824 }
825
826 switch (ln->ln_state) {
827 case ND6_LLINFO_INCOMPLETE:
828 if (ln->la_asked < V_nd6_mmaxtries) {
829 ln->la_asked++;
830 send_ns = 1;
831 /* Send NS to multicast address */
832 pdst = NULL;
833 } else {
834 struct mbuf *m;
835
836 ICMP6STAT_ADD(icp6s_dropped, ln->la_numheld);
837
838 m = ln->la_hold;
839 if (m != NULL) {
840 /*
841 * assuming every packet in la_hold has the
842 * same IP header. Send error after unlock.
843 */
844 ln->la_hold = m->m_nextpkt;
845 m->m_nextpkt = NULL;
846 ln->la_numheld--;
847 }
848 nd6_free(&ln, 0);
849 if (m != NULL) {
850 struct mbuf *n = m;
851
852 /*
853 * if there are any ummapped mbufs, we
854 * must free them, rather than using
855 * them for an ICMP, as they cannot be
856 * checksummed.
857 */
858 while ((n = n->m_next) != NULL) {
859 if (n->m_flags & M_EXTPG)
860 break;
861 }
862 if (n != NULL) {
863 m_freem(m);
864 m = NULL;
865 } else {
866 icmp6_error2(m, ICMP6_DST_UNREACH,
867 ICMP6_DST_UNREACH_ADDR, 0, ifp);
868 }
869 }
870 }
871 break;
872 case ND6_LLINFO_REACHABLE:
873 if (!ND6_LLINFO_PERMANENT(ln))
874 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
875 break;
876
877 case ND6_LLINFO_STALE:
878 if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
879 /*
880 * No packet has used this entry and GC timeout
881 * has not been passed. Reschedule timer and
882 * return.
883 */
884 nd6_llinfo_settimer_locked(ln, delay);
885 break;
886 }
887
888 if (do_switch == 0) {
889 /*
890 * GC timer has ended and entry hasn't been used.
891 * Run Garbage collector (RFC 4861, 5.3)
892 */
893 if (!ND6_LLINFO_PERMANENT(ln))
894 nd6_free(&ln, 1);
895 break;
896 }
897
898 /* Entry has been used AND delay timer has ended. */
899
900 /* FALLTHROUGH */
901
902 case ND6_LLINFO_DELAY:
903 if ((ndi->nd_flags & ND6_IFF_PERFORMNUD) != 0) {
904 /* We need NUD */
905 ln->la_asked = 1;
906 nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
907 send_ns = 1;
908 } else
909 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
910 break;
911 case ND6_LLINFO_PROBE:
912 if (ln->la_asked < V_nd6_umaxtries) {
913 ln->la_asked++;
914 send_ns = 1;
915 } else {
916 nd6_free(&ln, 0);
917 }
918 break;
919 default:
920 panic("%s: paths in a dark night can be confusing: %d",
921 __func__, ln->ln_state);
922 }
923 done:
924 if (ln != NULL)
925 ND6_RUNLOCK();
926 if (send_ns != 0) {
927 nd6_llinfo_settimer_locked(ln,
928 (long)ndi->nd_retrans * hz / 1000);
929 psrc = nd6_llinfo_get_holdsrc(ln, &src);
930 LLE_FREE_LOCKED(ln);
931 ln = NULL;
932 nd6_ns_output(ifp, psrc, pdst, dst, NULL);
933 }
934
935 if (ln != NULL)
936 LLE_FREE_LOCKED(ln);
937 NET_EPOCH_EXIT(et);
938 CURVNET_RESTORE();
939 }
940
941 /*
942 * ND6 timer routine to expire default route list and prefix list
943 */
944 void
nd6_timer(void * arg)945 nd6_timer(void *arg)
946 {
947 CURVNET_SET((struct vnet *) arg);
948 struct epoch_tracker et;
949 struct nd_prhead prl;
950 struct nd_prefix *pr, *npr;
951 struct ifnet *ifp;
952 struct in6_ifaddr *ia6, *nia6;
953 uint64_t genid;
954
955 LIST_INIT(&prl);
956
957 NET_EPOCH_ENTER(et);
958 nd6_defrouter_timer();
959
960 /*
961 * expire interface addresses.
962 * in the past the loop was inside prefix expiry processing.
963 * However, from a stricter speci-confrmance standpoint, we should
964 * rather separate address lifetimes and prefix lifetimes.
965 *
966 * XXXRW: in6_ifaddrhead locking.
967 */
968 addrloop:
969 CK_STAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
970 /* check address lifetime */
971 if (IFA6_IS_INVALID(ia6)) {
972 int regen = 0;
973
974 /*
975 * If the expiring address is temporary, try
976 * regenerating a new one. This would be useful when
977 * we suspended a laptop PC, then turned it on after a
978 * period that could invalidate all temporary
979 * addresses. Although we may have to restart the
980 * loop (see below), it must be after purging the
981 * address. Otherwise, we'd see an infinite loop of
982 * regeneration.
983 */
984 if (V_ip6_use_tempaddr &&
985 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
986 if (regen_tmpaddr(ia6) == 0)
987 regen = 1;
988 }
989
990 in6_purgeaddr(&ia6->ia_ifa);
991
992 if (regen)
993 goto addrloop; /* XXX: see below */
994 } else if (IFA6_IS_DEPRECATED(ia6)) {
995 int oldflags = ia6->ia6_flags;
996
997 ia6->ia6_flags |= IN6_IFF_DEPRECATED;
998
999 /*
1000 * If a temporary address has just become deprecated,
1001 * regenerate a new one if possible.
1002 */
1003 if (V_ip6_use_tempaddr &&
1004 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1005 (oldflags & IN6_IFF_DEPRECATED) == 0) {
1006 if (regen_tmpaddr(ia6) == 0) {
1007 /*
1008 * A new temporary address is
1009 * generated.
1010 * XXX: this means the address chain
1011 * has changed while we are still in
1012 * the loop. Although the change
1013 * would not cause disaster (because
1014 * it's not a deletion, but an
1015 * addition,) we'd rather restart the
1016 * loop just for safety. Or does this
1017 * significantly reduce performance??
1018 */
1019 goto addrloop;
1020 }
1021 }
1022 } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
1023 /*
1024 * Schedule DAD for a tentative address. This happens
1025 * if the interface was down or not running
1026 * when the address was configured.
1027 */
1028 int delay;
1029
1030 delay = arc4random() %
1031 (MAX_RTR_SOLICITATION_DELAY * hz);
1032 nd6_dad_start((struct ifaddr *)ia6, delay);
1033 } else {
1034 /*
1035 * Check status of the interface. If it is down,
1036 * mark the address as tentative for future DAD.
1037 */
1038 ifp = ia6->ia_ifp;
1039 if ((ifp->if_inet6->nd_flags & ND6_IFF_NO_DAD) == 0 &&
1040 ((ifp->if_flags & IFF_UP) == 0 ||
1041 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1042 (ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED))){
1043 ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
1044 ia6->ia6_flags |= IN6_IFF_TENTATIVE;
1045 }
1046
1047 /*
1048 * A new RA might have made a deprecated address
1049 * preferred.
1050 */
1051 ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
1052 }
1053 }
1054 NET_EPOCH_EXIT(et);
1055
1056 ND6_WLOCK();
1057 restart:
1058 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1059 /*
1060 * Expire prefixes. Since the pltime is only used for
1061 * autoconfigured addresses, pltime processing for prefixes is
1062 * not necessary.
1063 *
1064 * Only unlink after all derived addresses have expired. This
1065 * may not occur until two hours after the prefix has expired
1066 * per RFC 4862. If the prefix expires before its derived
1067 * addresses, mark it off-link. This will be done automatically
1068 * after unlinking if no address references remain.
1069 */
1070 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME ||
1071 time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime)
1072 continue;
1073
1074 if (pr->ndpr_addrcnt == 0) {
1075 nd6_prefix_unlink(pr, &prl);
1076 continue;
1077 }
1078 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1079 genid = V_nd6_list_genid;
1080 nd6_prefix_ref(pr);
1081 ND6_WUNLOCK();
1082 ND6_ONLINK_LOCK();
1083 (void)nd6_prefix_offlink(pr);
1084 ND6_ONLINK_UNLOCK();
1085 ND6_WLOCK();
1086 nd6_prefix_rele(pr);
1087 if (genid != V_nd6_list_genid)
1088 goto restart;
1089 }
1090 }
1091 ND6_WUNLOCK();
1092
1093 while ((pr = LIST_FIRST(&prl)) != NULL) {
1094 LIST_REMOVE(pr, ndpr_entry);
1095 nd6_prefix_del(pr);
1096 }
1097
1098 callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
1099 nd6_timer, curvnet);
1100
1101 CURVNET_RESTORE();
1102 }
1103
1104 /*
1105 * ia6 - deprecated/invalidated temporary address
1106 */
1107 static int
regen_tmpaddr(struct in6_ifaddr * ia6)1108 regen_tmpaddr(struct in6_ifaddr *ia6)
1109 {
1110 struct ifaddr *ifa;
1111 struct ifnet *ifp;
1112 struct in6_ifaddr *public_ifa6 = NULL;
1113
1114 NET_EPOCH_ASSERT();
1115
1116 ifp = ia6->ia_ifa.ifa_ifp;
1117 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1118 struct in6_ifaddr *it6;
1119
1120 if (ifa->ifa_addr->sa_family != AF_INET6)
1121 continue;
1122
1123 it6 = (struct in6_ifaddr *)ifa;
1124
1125 /* ignore no autoconf addresses. */
1126 if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1127 continue;
1128
1129 /* ignore autoconf addresses with different prefixes. */
1130 if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
1131 continue;
1132
1133 /*
1134 * Now we are looking at an autoconf address with the same
1135 * prefix as ours. If the address is temporary and is still
1136 * preferred, do not create another one. It would be rare, but
1137 * could happen, for example, when we resume a laptop PC after
1138 * a long period.
1139 */
1140 if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1141 !IFA6_IS_DEPRECATED(it6)) {
1142 public_ifa6 = NULL;
1143 break;
1144 }
1145
1146 /*
1147 * This is a public autoconf address that has the same prefix
1148 * as ours. If it is preferred, keep it. We can't break the
1149 * loop here, because there may be a still-preferred temporary
1150 * address with the prefix.
1151 */
1152 if (!IFA6_IS_DEPRECATED(it6))
1153 public_ifa6 = it6;
1154 }
1155 if (public_ifa6 != NULL)
1156 ifa_ref(&public_ifa6->ia_ifa);
1157
1158 if (public_ifa6 != NULL) {
1159 int e;
1160
1161 if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
1162 ifa_free(&public_ifa6->ia_ifa);
1163 log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
1164 " tmp addr,errno=%d\n", e);
1165 return (-1);
1166 }
1167 ifa_free(&public_ifa6->ia_ifa);
1168 return (0);
1169 }
1170
1171 return (-1);
1172 }
1173
1174 /*
1175 * Remove prefix and default router list entries corresponding to ifp. Neighbor
1176 * cache entries are freed in in6_domifdetach().
1177 */
1178 void
nd6_purge(struct ifnet * ifp)1179 nd6_purge(struct ifnet *ifp)
1180 {
1181 struct nd_prhead prl;
1182 struct nd_prefix *pr, *npr;
1183
1184 LIST_INIT(&prl);
1185
1186 /* Purge default router list entries toward ifp. */
1187 nd6_defrouter_purge(ifp);
1188
1189 ND6_WLOCK();
1190 /*
1191 * Remove prefixes on ifp. We should have already removed addresses on
1192 * this interface, so no addresses should be referencing these prefixes.
1193 */
1194 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1195 if (pr->ndpr_ifp == ifp)
1196 nd6_prefix_unlink(pr, &prl);
1197 }
1198 ND6_WUNLOCK();
1199
1200 /* Delete the unlinked prefix objects. */
1201 while ((pr = LIST_FIRST(&prl)) != NULL) {
1202 LIST_REMOVE(pr, ndpr_entry);
1203 nd6_prefix_del(pr);
1204 }
1205
1206 /* cancel default outgoing interface setting */
1207 if (V_nd6_defifindex == ifp->if_index)
1208 nd6_setdefaultiface(0);
1209
1210 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) {
1211 /* Refresh default router list. */
1212 defrouter_select_fib(ifp->if_fib);
1213 }
1214 }
1215
1216 /*
1217 * the caller acquires and releases the lock on the lltbls
1218 * Returns the llentry locked
1219 */
1220 struct llentry *
nd6_lookup(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1221 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1222 {
1223 struct sockaddr_in6 sin6;
1224 struct llentry *ln;
1225
1226 bzero(&sin6, sizeof(sin6));
1227 sin6.sin6_len = sizeof(struct sockaddr_in6);
1228 sin6.sin6_family = AF_INET6;
1229 sin6.sin6_addr = *addr6;
1230
1231 LLTABLE_RLOCK_ASSERT(LLTABLE6(ifp));
1232
1233 ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
1234
1235 return (ln);
1236 }
1237
1238 static struct llentry *
nd6_alloc(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1239 nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1240 {
1241 struct sockaddr_in6 sin6;
1242 struct llentry *ln;
1243
1244 bzero(&sin6, sizeof(sin6));
1245 sin6.sin6_len = sizeof(struct sockaddr_in6);
1246 sin6.sin6_family = AF_INET6;
1247 sin6.sin6_addr = *addr6;
1248
1249 ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
1250 if (ln != NULL)
1251 ln->ln_state = ND6_LLINFO_NOSTATE;
1252
1253 return (ln);
1254 }
1255
1256 /*
1257 * Test whether a given IPv6 address can be a neighbor.
1258 */
1259 static bool
nd6_is_new_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1260 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1261 {
1262
1263 /*
1264 * A link-local address is always a neighbor.
1265 * XXX: a link does not necessarily specify a single interface.
1266 */
1267 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
1268 struct sockaddr_in6 sin6_copy;
1269 u_int32_t zone;
1270
1271 /*
1272 * We need sin6_copy since sa6_recoverscope() may modify the
1273 * content (XXX).
1274 */
1275 sin6_copy = *addr;
1276 if (sa6_recoverscope(&sin6_copy))
1277 return (0); /* XXX: should be impossible */
1278 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
1279 return (0);
1280 if (sin6_copy.sin6_scope_id == zone)
1281 return (1);
1282 else
1283 return (0);
1284 }
1285 /* Checking global unicast */
1286
1287 /* If an address is directly reachable, it is a neigbor */
1288 struct nhop_object *nh;
1289 nh = fib6_lookup(ifp->if_fib, &addr->sin6_addr, 0, NHR_NONE, 0);
1290 if (nh != NULL && nh->nh_aifp == ifp && (nh->nh_flags & NHF_GATEWAY) == 0)
1291 return (true);
1292
1293 /*
1294 * Check prefixes with desired on-link state, as some may be not
1295 * installed in the routing table.
1296 */
1297 bool matched = false;
1298 struct nd_prefix *pr;
1299 ND6_RLOCK();
1300 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1301 if (pr->ndpr_ifp != ifp)
1302 continue;
1303 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1304 continue;
1305 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1306 &addr->sin6_addr, &pr->ndpr_mask)) {
1307 matched = true;
1308 break;
1309 }
1310 }
1311 ND6_RUNLOCK();
1312 if (matched)
1313 return (true);
1314
1315 /*
1316 * If the address is assigned on the node of the other side of
1317 * a p2p interface, the address should be a neighbor.
1318 */
1319 if (ifp->if_flags & IFF_POINTOPOINT) {
1320 struct ifaddr *ifa;
1321
1322 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1323 if (ifa->ifa_addr->sa_family != addr->sin6_family)
1324 continue;
1325 if (ifa->ifa_dstaddr != NULL &&
1326 sa_equal(addr, ifa->ifa_dstaddr)) {
1327 return (true);
1328 }
1329 }
1330 }
1331
1332 /*
1333 * If the default router list is empty, all addresses are regarded
1334 * as on-link, and thus, as a neighbor.
1335 */
1336 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV &&
1337 nd6_defrouter_list_empty() &&
1338 V_nd6_defifindex == ifp->if_index) {
1339 return (1);
1340 }
1341
1342 return (0);
1343 }
1344
1345 /*
1346 * Detect if a given IPv6 address identifies a neighbor on a given link.
1347 * XXX: should take care of the destination of a p2p link?
1348 */
1349 int
nd6_is_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1350 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1351 {
1352 struct llentry *lle;
1353 int rc = 0;
1354
1355 NET_EPOCH_ASSERT();
1356
1357 if (nd6_is_new_addr_neighbor(addr, ifp))
1358 return (1);
1359
1360 /*
1361 * Even if the address matches none of our addresses, it might be
1362 * in the neighbor cache.
1363 */
1364 if ((lle = nd6_lookup(&addr->sin6_addr, LLE_SF(AF_INET6, 0), ifp)) != NULL) {
1365 LLE_RUNLOCK(lle);
1366 rc = 1;
1367 }
1368 return (rc);
1369 }
1370
1371 static __noinline void
nd6_free_children(struct llentry * lle)1372 nd6_free_children(struct llentry *lle)
1373 {
1374 struct llentry *child_lle;
1375
1376 NET_EPOCH_ASSERT();
1377 LLE_WLOCK_ASSERT(lle);
1378
1379 while ((child_lle = CK_SLIST_FIRST(&lle->lle_children)) != NULL) {
1380 LLE_WLOCK(child_lle);
1381 lltable_unlink_child_entry(child_lle);
1382 llentry_free(child_lle);
1383 }
1384 }
1385
1386 /*
1387 * Tries to update @lle address/prepend data with new @lladdr.
1388 *
1389 * Returns true on success.
1390 * In any case, @lle is returned wlocked.
1391 */
1392 static __noinline bool
nd6_try_set_entry_addr_locked(struct ifnet * ifp,struct llentry * lle,char * lladdr)1393 nd6_try_set_entry_addr_locked(struct ifnet *ifp, struct llentry *lle, char *lladdr)
1394 {
1395 u_char buf[LLE_MAX_LINKHDR];
1396 int fam, off;
1397 size_t sz;
1398
1399 sz = sizeof(buf);
1400 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, buf, &sz, &off) != 0)
1401 return (false);
1402
1403 /* Update data */
1404 lltable_set_entry_addr(ifp, lle, buf, sz, off);
1405
1406 struct llentry *child_lle;
1407 CK_SLIST_FOREACH(child_lle, &lle->lle_children, lle_child_next) {
1408 LLE_WLOCK(child_lle);
1409 fam = child_lle->r_family;
1410 sz = sizeof(buf);
1411 if (lltable_calc_llheader(ifp, fam, lladdr, buf, &sz, &off) == 0) {
1412 /* success */
1413 lltable_set_entry_addr(ifp, child_lle, buf, sz, off);
1414 child_lle->ln_state = ND6_LLINFO_REACHABLE;
1415 }
1416 LLE_WUNLOCK(child_lle);
1417 }
1418
1419 return (true);
1420 }
1421
1422 bool
nd6_try_set_entry_addr(struct ifnet * ifp,struct llentry * lle,char * lladdr)1423 nd6_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle, char *lladdr)
1424 {
1425 NET_EPOCH_ASSERT();
1426 LLE_WLOCK_ASSERT(lle);
1427
1428 if (!lltable_trylock(lle))
1429 return (false);
1430 bool ret = nd6_try_set_entry_addr_locked(ifp, lle, lladdr);
1431 LLTABLE_UNLOCK(lle->lle_tbl);
1432
1433 return (ret);
1434 }
1435
1436 /*
1437 * Free an nd6 llinfo entry.
1438 * Since the function would cause significant changes in the kernel, DO NOT
1439 * make it global, unless you have a strong reason for the change, and are sure
1440 * that the change is safe.
1441 *
1442 * Set noinline to be dtrace-friendly
1443 */
1444 static __noinline void
nd6_free(struct llentry ** lnp,int gc)1445 nd6_free(struct llentry **lnp, int gc)
1446 {
1447 struct ifnet *ifp;
1448 struct llentry *ln;
1449 struct nd_defrouter *dr;
1450
1451 ln = *lnp;
1452 *lnp = NULL;
1453
1454 LLE_WLOCK_ASSERT(ln);
1455 ND6_RLOCK_ASSERT();
1456
1457 KASSERT((ln->la_flags & LLE_CHILD) == 0, ("child lle"));
1458
1459 ifp = lltable_get_ifp(ln->lle_tbl);
1460 if ((ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) != 0)
1461 dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
1462 else
1463 dr = NULL;
1464 ND6_RUNLOCK();
1465
1466 if ((ln->la_flags & LLE_DELETED) == 0)
1467 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
1468
1469 /*
1470 * we used to have pfctlinput(PRC_HOSTDEAD) here.
1471 * even though it is not harmful, it was not really necessary.
1472 */
1473
1474 /* cancel timer */
1475 nd6_llinfo_settimer_locked(ln, -1);
1476
1477 if (ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) {
1478 if (dr != NULL && dr->expire &&
1479 ln->ln_state == ND6_LLINFO_STALE && gc) {
1480 /*
1481 * If the reason for the deletion is just garbage
1482 * collection, and the neighbor is an active default
1483 * router, do not delete it. Instead, reset the GC
1484 * timer using the router's lifetime.
1485 * Simply deleting the entry would affect default
1486 * router selection, which is not necessarily a good
1487 * thing, especially when we're using router preference
1488 * values.
1489 * XXX: the check for ln_state would be redundant,
1490 * but we intentionally keep it just in case.
1491 */
1492 if (dr->expire > time_uptime)
1493 nd6_llinfo_settimer_locked(ln,
1494 (dr->expire - time_uptime) * hz);
1495 else
1496 nd6_llinfo_settimer_locked(ln,
1497 (long)V_nd6_gctimer * hz);
1498
1499 LLE_REMREF(ln);
1500 LLE_WUNLOCK(ln);
1501 defrouter_rele(dr);
1502 return;
1503 }
1504
1505 if (dr) {
1506 /*
1507 * Unreachability of a router might affect the default
1508 * router selection and on-link detection of advertised
1509 * prefixes.
1510 */
1511
1512 /*
1513 * Temporarily fake the state to choose a new default
1514 * router and to perform on-link determination of
1515 * prefixes correctly.
1516 * Below the state will be set correctly,
1517 * or the entry itself will be deleted.
1518 */
1519 ln->ln_state = ND6_LLINFO_INCOMPLETE;
1520 }
1521
1522 if (ln->ln_router || dr) {
1523 /*
1524 * We need to unlock to avoid a LOR with rt6_flush() with the
1525 * rnh and for the calls to pfxlist_onlink_check() and
1526 * defrouter_select_fib() in the block further down for calls
1527 * into nd6_lookup(). We still hold a ref.
1528 */
1529 LLE_WUNLOCK(ln);
1530
1531 /*
1532 * rt6_flush must be called whether or not the neighbor
1533 * is in the Default Router List.
1534 * See a corresponding comment in nd6_na_input().
1535 */
1536 rt6_flush(&ln->r_l3addr.addr6, ifp);
1537 }
1538
1539 if (dr) {
1540 /*
1541 * Since defrouter_select_fib() does not affect the
1542 * on-link determination and MIP6 needs the check
1543 * before the default router selection, we perform
1544 * the check now.
1545 */
1546 pfxlist_onlink_check();
1547
1548 /*
1549 * Refresh default router list.
1550 */
1551 defrouter_select_fib(dr->ifp->if_fib);
1552 }
1553
1554 /*
1555 * If this entry was added by an on-link redirect, remove the
1556 * corresponding host route.
1557 */
1558 if (ln->la_flags & LLE_REDIRECT)
1559 nd6_free_redirect(ln);
1560
1561 if (ln->ln_router || dr)
1562 LLE_WLOCK(ln);
1563 }
1564
1565 /*
1566 * Save to unlock. We still hold an extra reference and will not
1567 * free(9) in llentry_free() if someone else holds one as well.
1568 */
1569 LLE_WUNLOCK(ln);
1570 LLTABLE_LOCK(ln->lle_tbl);
1571 LLE_WLOCK(ln);
1572 /* Guard against race with other llentry_free(). */
1573 if (ln->la_flags & LLE_LINKED) {
1574 /* Remove callout reference */
1575 LLE_REMREF(ln);
1576 lltable_unlink_entry(ln->lle_tbl, ln);
1577 }
1578 LLTABLE_UNLOCK(ln->lle_tbl);
1579
1580 nd6_free_children(ln);
1581
1582 llentry_free(ln);
1583 if (dr != NULL)
1584 defrouter_rele(dr);
1585 }
1586
1587 static int
nd6_isdynrte(const struct rtentry * rt,const struct nhop_object * nh,void * xap)1588 nd6_isdynrte(const struct rtentry *rt, const struct nhop_object *nh, void *xap)
1589 {
1590
1591 if (nh->nh_flags & NHF_REDIRECT)
1592 return (1);
1593
1594 return (0);
1595 }
1596
1597 /*
1598 * Remove the rtentry for the given llentry,
1599 * both of which were installed by a redirect.
1600 */
1601 static void
nd6_free_redirect(const struct llentry * ln)1602 nd6_free_redirect(const struct llentry *ln)
1603 {
1604 int fibnum;
1605 struct sockaddr_in6 sin6;
1606 struct rib_cmd_info rc;
1607 struct epoch_tracker et;
1608
1609 lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
1610
1611 NET_EPOCH_ENTER(et);
1612 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
1613 rib_del_route_px(fibnum, (struct sockaddr *)&sin6, 128,
1614 nd6_isdynrte, NULL, 0, &rc);
1615 NET_EPOCH_EXIT(et);
1616 }
1617
1618 /*
1619 * Updates status of the default router route.
1620 */
1621 static void
check_release_defrouter(const struct rib_cmd_info * rc,void * _cbdata)1622 check_release_defrouter(const struct rib_cmd_info *rc, void *_cbdata)
1623 {
1624 struct nd_defrouter *dr;
1625 struct nhop_object *nh;
1626
1627 nh = rc->rc_nh_old;
1628 if (rc->rc_cmd == RTM_DELETE && (nh->nh_flags & NHF_DEFAULT) != 0) {
1629 dr = defrouter_lookup(&nh->gw6_sa.sin6_addr, nh->nh_ifp);
1630 if (dr != NULL) {
1631 dr->installed = 0;
1632 defrouter_rele(dr);
1633 }
1634 }
1635 }
1636
1637 void
nd6_subscription_cb(struct rib_head * rnh,struct rib_cmd_info * rc,void * arg)1638 nd6_subscription_cb(struct rib_head *rnh, struct rib_cmd_info *rc, void *arg)
1639 {
1640 #ifdef ROUTE_MPATH
1641 rib_decompose_notification(rc, check_release_defrouter, NULL);
1642 if (rc->rc_cmd == RTM_DELETE && !NH_IS_NHGRP(rc->rc_nh_old))
1643 check_release_defrouter(rc, NULL);
1644 #else
1645 check_release_defrouter(rc, NULL);
1646 #endif
1647 }
1648
1649 int
nd6_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp)1650 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
1651 {
1652 struct epoch_tracker et;
1653 struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1654 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1655 struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1656 struct in6_ifextra *ext = ifp->if_inet6;
1657 int error = 0;
1658
1659 /* XXXGL: safety against IFT_PFSYNC & IFT_PFLOG */
1660 if (ext == NULL)
1661 return (EPFNOSUPPORT);
1662 #define ND ndi->ndi
1663 switch (cmd) {
1664 case SIOCGIFINFO_IN6:
1665 ND = (struct nd_ifinfo){
1666 .linkmtu = ext->nd_linkmtu,
1667 .maxmtu = ext->nd_maxmtu,
1668 .basereachable = ext->nd_basereachable,
1669 .reachable = ext->nd_reachable,
1670 .retrans = ext->nd_retrans,
1671 .flags = ext->nd_flags,
1672 .recalctm = ext->nd_recalc_timer,
1673 .chlim = ext->nd_curhoplimit,
1674 .initialized = 1,
1675 };
1676 break;
1677 case SIOCSIFINFO_IN6:
1678 /*
1679 * used to change host variables from userland.
1680 * intended for a use on router to reflect RA configurations.
1681 */
1682 /* 0 means 'unspecified' */
1683 if (ND.linkmtu != 0) {
1684 if (ND.linkmtu < IPV6_MMTU ||
1685 ND.linkmtu > in6_ifmtu(ifp)) {
1686 error = EINVAL;
1687 break;
1688 }
1689 ext->nd_linkmtu = ND.linkmtu;
1690 }
1691
1692 if (ND.basereachable != 0) {
1693 uint32_t obasereachable = ext->nd_basereachable;
1694
1695 ext->nd_basereachable = ND.basereachable;
1696 if (ND.basereachable != obasereachable)
1697 ext->nd_reachable =
1698 ND_COMPUTE_RTIME(ND.basereachable);
1699 }
1700 if (ND.retrans != 0)
1701 ext->nd_retrans = ND.retrans;
1702 if (ND.chlim != 0)
1703 ext->nd_curhoplimit = ND.chlim;
1704 /* FALLTHROUGH */
1705 case SIOCSIFINFO_FLAGS:
1706 {
1707 struct ifaddr *ifa;
1708 struct in6_ifaddr *ia;
1709
1710 if ((ext->nd_flags & ND6_IFF_IFDISABLED) &&
1711 !(ND.flags & ND6_IFF_IFDISABLED)) {
1712 /* ifdisabled 1->0 transision */
1713
1714 /*
1715 * If the interface is marked as ND6_IFF_IFDISABLED and
1716 * has an link-local address with IN6_IFF_DUPLICATED,
1717 * do not clear ND6_IFF_IFDISABLED.
1718 * See RFC 4862, Section 5.4.5.
1719 */
1720 NET_EPOCH_ENTER(et);
1721 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1722 if (ifa->ifa_addr->sa_family != AF_INET6)
1723 continue;
1724 ia = (struct in6_ifaddr *)ifa;
1725 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1726 IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1727 break;
1728 }
1729 NET_EPOCH_EXIT(et);
1730
1731 if (ifa != NULL) {
1732 /* LLA is duplicated. */
1733 ND.flags |= ND6_IFF_IFDISABLED;
1734 log(LOG_ERR, "Cannot enable an interface"
1735 " with a link-local address marked"
1736 " duplicate.\n");
1737 } else {
1738 ext->nd_flags &= ~ND6_IFF_IFDISABLED;
1739 if (ifp->if_flags & IFF_UP)
1740 in6_if_up(ifp);
1741 }
1742 } else if (!(ext->nd_flags & ND6_IFF_IFDISABLED) &&
1743 (ND.flags & ND6_IFF_IFDISABLED)) {
1744 /* ifdisabled 0->1 transision */
1745 /* Mark all IPv6 address as tentative. */
1746
1747 ext->nd_flags |= ND6_IFF_IFDISABLED;
1748 if (V_ip6_dad_count > 0 &&
1749 (ext->nd_flags & ND6_IFF_NO_DAD) == 0) {
1750 NET_EPOCH_ENTER(et);
1751 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1752 ifa_link) {
1753 if (ifa->ifa_addr->sa_family !=
1754 AF_INET6)
1755 continue;
1756 ia = (struct in6_ifaddr *)ifa;
1757 ia->ia6_flags |= IN6_IFF_TENTATIVE;
1758 }
1759 NET_EPOCH_EXIT(et);
1760 }
1761 }
1762
1763 if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1764 if (!(ext->nd_flags & ND6_IFF_AUTO_LINKLOCAL)) {
1765 /* auto_linklocal 0->1 transision */
1766
1767 /* If no link-local address on ifp, configure */
1768 ext->nd_flags |= ND6_IFF_AUTO_LINKLOCAL;
1769 in6_ifattach(ifp, NULL);
1770 } else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1771 ifp->if_flags & IFF_UP) {
1772 /*
1773 * When the IF already has
1774 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1775 * address is assigned, and IFF_UP, try to
1776 * assign one.
1777 */
1778 NET_EPOCH_ENTER(et);
1779 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1780 ifa_link) {
1781 if (ifa->ifa_addr->sa_family !=
1782 AF_INET6)
1783 continue;
1784 ia = (struct in6_ifaddr *)ifa;
1785 if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1786 break;
1787 }
1788 NET_EPOCH_EXIT(et);
1789 if (ifa != NULL)
1790 /* No LLA is configured. */
1791 in6_ifattach(ifp, NULL);
1792 }
1793 }
1794 ext->nd_flags = ND.flags;
1795 break;
1796 }
1797 #undef ND
1798 case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */
1799 /* sync kernel routing table with the default router list */
1800 defrouter_reset();
1801 defrouter_select_fib(RT_ALL_FIBS);
1802 break;
1803 case SIOCSPFXFLUSH_IN6:
1804 {
1805 /* flush all the prefix advertised by routers */
1806 struct in6_ifaddr *ia, *ia_next;
1807 struct nd_prefix *pr, *next;
1808 struct nd_prhead prl;
1809
1810 LIST_INIT(&prl);
1811
1812 ND6_WLOCK();
1813 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
1814 if (ND6_PREFIX_WITH_ROUTER(pr))
1815 nd6_prefix_unlink(pr, &prl);
1816 }
1817 ND6_WUNLOCK();
1818
1819 while ((pr = LIST_FIRST(&prl)) != NULL) {
1820 LIST_REMOVE(pr, ndpr_entry);
1821 /* XXXRW: in6_ifaddrhead locking. */
1822 CK_STAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
1823 ia_next) {
1824 if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1825 continue;
1826
1827 if (ia->ia6_ndpr == pr)
1828 in6_purgeaddr(&ia->ia_ifa);
1829 }
1830 nd6_prefix_del(pr);
1831 }
1832 break;
1833 }
1834 case SIOCSRTRFLUSH_IN6:
1835 {
1836 /* flush all the default routers */
1837
1838 defrouter_reset();
1839 nd6_defrouter_flush_all();
1840 defrouter_select_fib(RT_ALL_FIBS);
1841 break;
1842 }
1843 case SIOCGNBRINFO_IN6:
1844 {
1845 struct llentry *ln;
1846 struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1847
1848 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1849 return (error);
1850
1851 NET_EPOCH_ENTER(et);
1852 ln = nd6_lookup(&nb_addr, LLE_SF(AF_INET6, 0), ifp);
1853 NET_EPOCH_EXIT(et);
1854
1855 if (ln == NULL) {
1856 error = EINVAL;
1857 break;
1858 }
1859 nbi->state = ln->ln_state;
1860 nbi->asked = ln->la_asked;
1861 nbi->isrouter = ln->ln_router;
1862 if (ln->la_expire == 0)
1863 nbi->expire = 0;
1864 else
1865 nbi->expire = ln->la_expire + ln->lle_remtime / hz +
1866 (time_second - time_uptime);
1867 LLE_RUNLOCK(ln);
1868 break;
1869 }
1870 case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1871 ndif->ifindex = V_nd6_defifindex;
1872 break;
1873 case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1874 return (nd6_setdefaultiface(ndif->ifindex));
1875 }
1876 return (error);
1877 }
1878
1879 /*
1880 * Calculates new isRouter value based on provided parameters and
1881 * returns it.
1882 */
1883 static int
nd6_is_router(int type,int code,int is_new,int old_addr,int new_addr,int ln_router)1884 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
1885 int ln_router)
1886 {
1887
1888 /*
1889 * ICMP6 type dependent behavior.
1890 *
1891 * NS: clear IsRouter if new entry
1892 * RS: clear IsRouter
1893 * RA: set IsRouter if there's lladdr
1894 * redir: clear IsRouter if new entry
1895 *
1896 * RA case, (1):
1897 * The spec says that we must set IsRouter in the following cases:
1898 * - If lladdr exist, set IsRouter. This means (1-5).
1899 * - If it is old entry (!newentry), set IsRouter. This means (7).
1900 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1901 * A quetion arises for (1) case. (1) case has no lladdr in the
1902 * neighbor cache, this is similar to (6).
1903 * This case is rare but we figured that we MUST NOT set IsRouter.
1904 *
1905 * is_new old_addr new_addr NS RS RA redir
1906 * D R
1907 * 0 n n (1) c ? s
1908 * 0 y n (2) c s s
1909 * 0 n y (3) c s s
1910 * 0 y y (4) c s s
1911 * 0 y y (5) c s s
1912 * 1 -- n (6) c c c s
1913 * 1 -- y (7) c c s c s
1914 *
1915 * (c=clear s=set)
1916 */
1917 switch (type & 0xff) {
1918 case ND_NEIGHBOR_SOLICIT:
1919 /*
1920 * New entry must have is_router flag cleared.
1921 */
1922 if (is_new) /* (6-7) */
1923 ln_router = 0;
1924 break;
1925 case ND_REDIRECT:
1926 /*
1927 * If the icmp is a redirect to a better router, always set the
1928 * is_router flag. Otherwise, if the entry is newly created,
1929 * clear the flag. [RFC 2461, sec 8.3]
1930 */
1931 if (code == ND_REDIRECT_ROUTER)
1932 ln_router = 1;
1933 else {
1934 if (is_new) /* (6-7) */
1935 ln_router = 0;
1936 }
1937 break;
1938 case ND_ROUTER_SOLICIT:
1939 /*
1940 * is_router flag must always be cleared.
1941 */
1942 ln_router = 0;
1943 break;
1944 case ND_ROUTER_ADVERT:
1945 /*
1946 * Mark an entry with lladdr as a router.
1947 */
1948 if ((!is_new && (old_addr || new_addr)) || /* (2-5) */
1949 (is_new && new_addr)) { /* (7) */
1950 ln_router = 1;
1951 }
1952 break;
1953 }
1954
1955 return (ln_router);
1956 }
1957
1958 /*
1959 * Create neighbor cache entry and cache link-layer address,
1960 * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1961 *
1962 * type - ICMP6 type
1963 * code - type dependent information
1964 *
1965 */
1966 void
nd6_cache_lladdr(struct ifnet * ifp,struct in6_addr * from,char * lladdr,int lladdrlen,int type,int code)1967 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1968 int lladdrlen, int type, int code)
1969 {
1970 struct llentry *ln = NULL, *ln_tmp;
1971 int is_newentry;
1972 int do_update;
1973 int olladdr;
1974 int llchange;
1975 int flags;
1976 uint16_t router = 0;
1977 struct mbuf *chain = NULL;
1978 u_char linkhdr[LLE_MAX_LINKHDR];
1979 size_t linkhdrsize;
1980 int lladdr_off;
1981
1982 NET_EPOCH_ASSERT();
1983
1984 KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
1985 KASSERT(from != NULL, ("%s: from == NULL", __func__));
1986
1987 /* nothing must be updated for unspecified address */
1988 if (IN6_IS_ADDR_UNSPECIFIED(from))
1989 return;
1990
1991 /*
1992 * Validation about ifp->if_addrlen and lladdrlen must be done in
1993 * the caller.
1994 *
1995 * XXX If the link does not have link-layer adderss, what should
1996 * we do? (ifp->if_addrlen == 0)
1997 * Spec says nothing in sections for RA, RS and NA. There's small
1998 * description on it in NS section (RFC 2461 7.2.3).
1999 */
2000 flags = lladdr ? LLE_EXCLUSIVE : 0;
2001 ln = nd6_lookup(from, LLE_SF(AF_INET6, flags), ifp);
2002 is_newentry = 0;
2003 if (ln == NULL) {
2004 flags |= LLE_EXCLUSIVE;
2005 ln = nd6_alloc(from, 0, ifp);
2006 if (ln == NULL)
2007 return;
2008
2009 /*
2010 * Since we already know all the data for the new entry,
2011 * fill it before insertion.
2012 */
2013 if (lladdr != NULL) {
2014 linkhdrsize = sizeof(linkhdr);
2015 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
2016 linkhdr, &linkhdrsize, &lladdr_off) != 0) {
2017 lltable_free_entry(LLTABLE6(ifp), ln);
2018 return;
2019 }
2020 lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
2021 lladdr_off);
2022 }
2023
2024 LLTABLE_LOCK(LLTABLE6(ifp));
2025 LLE_WLOCK(ln);
2026 /* Prefer any existing lle over newly-created one */
2027 ln_tmp = nd6_lookup(from, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
2028 if (ln_tmp == NULL)
2029 lltable_link_entry(LLTABLE6(ifp), ln);
2030 LLTABLE_UNLOCK(LLTABLE6(ifp));
2031 if (ln_tmp == NULL) {
2032 /* No existing lle, mark as new entry (6,7) */
2033 is_newentry = 1;
2034 if (lladdr != NULL) { /* (7) */
2035 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2036 EVENTHANDLER_INVOKE(lle_event, ln,
2037 LLENTRY_RESOLVED);
2038 }
2039 } else {
2040 lltable_free_entry(LLTABLE6(ifp), ln);
2041 ln = ln_tmp;
2042 ln_tmp = NULL;
2043 }
2044 }
2045 /* do nothing if static ndp is set */
2046 if ((ln->la_flags & LLE_STATIC)) {
2047 if (flags & LLE_EXCLUSIVE)
2048 LLE_WUNLOCK(ln);
2049 else
2050 LLE_RUNLOCK(ln);
2051 return;
2052 }
2053
2054 olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
2055 if (olladdr && lladdr) {
2056 llchange = bcmp(lladdr, ln->ll_addr,
2057 ifp->if_addrlen);
2058 } else if (!olladdr && lladdr)
2059 llchange = 1;
2060 else
2061 llchange = 0;
2062
2063 /*
2064 * newentry olladdr lladdr llchange (*=record)
2065 * 0 n n -- (1)
2066 * 0 y n -- (2)
2067 * 0 n y y (3) * STALE
2068 * 0 y y n (4) *
2069 * 0 y y y (5) * STALE
2070 * 1 -- n -- (6) NOSTATE(= PASSIVE)
2071 * 1 -- y -- (7) * STALE
2072 */
2073
2074 do_update = 0;
2075 if (is_newentry == 0 && llchange != 0) {
2076 do_update = 1; /* (3,5) */
2077
2078 /*
2079 * Record source link-layer address
2080 * XXX is it dependent to ifp->if_type?
2081 */
2082 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) {
2083 /* Entry was deleted */
2084 LLE_WUNLOCK(ln);
2085 return;
2086 }
2087
2088 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2089
2090 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2091
2092 if (ln->la_hold != NULL)
2093 chain = nd6_grab_holdchain(ln);
2094 }
2095
2096 /* Calculates new router status */
2097 router = nd6_is_router(type, code, is_newentry, olladdr,
2098 lladdr != NULL ? 1 : 0, ln->ln_router);
2099
2100 ln->ln_router = router;
2101 /* Mark non-router redirects with special flag */
2102 if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
2103 ln->la_flags |= LLE_REDIRECT;
2104
2105 if (flags & LLE_EXCLUSIVE)
2106 LLE_WUNLOCK(ln);
2107 else
2108 LLE_RUNLOCK(ln);
2109
2110 if (chain != NULL)
2111 nd6_flush_holdchain(ifp, ln, chain);
2112 if (do_update)
2113 nd6_flush_children_holdchain(ifp, ln);
2114
2115 /*
2116 * When the link-layer address of a router changes, select the
2117 * best router again. In particular, when the neighbor entry is newly
2118 * created, it might affect the selection policy.
2119 * Question: can we restrict the first condition to the "is_newentry"
2120 * case?
2121 * XXX: when we hear an RA from a new router with the link-layer
2122 * address option, defrouter_select_fib() is called twice, since
2123 * defrtrlist_update called the function as well. However, I believe
2124 * we can compromise the overhead, since it only happens the first
2125 * time.
2126 * XXX: although defrouter_select_fib() should not have a bad effect
2127 * for those are not autoconfigured hosts, we explicitly avoid such
2128 * cases for safety.
2129 */
2130 if ((do_update || is_newentry) && router &&
2131 ifp->if_inet6->nd_flags & ND6_IFF_ACCEPT_RTADV) {
2132 /*
2133 * guaranteed recursion
2134 */
2135 defrouter_select_fib(ifp->if_fib);
2136 }
2137 }
2138
2139 static void
nd6_slowtimo(void * arg)2140 nd6_slowtimo(void *arg)
2141 {
2142 struct epoch_tracker et;
2143 CURVNET_SET((struct vnet *) arg);
2144 struct in6_ifextra *nd6if;
2145 struct ifnet *ifp;
2146
2147 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
2148 nd6_slowtimo, curvnet);
2149 NET_EPOCH_ENTER(et);
2150 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2151 if ((nd6if = ifp->if_inet6) == NULL)
2152 continue;
2153 if (nd6if->nd_basereachable && /* already initialized */
2154 (nd6if->nd_recalc_timer -= ND6_SLOWTIMER_INTERVAL) <= 0) {
2155 /*
2156 * Since reachable time rarely changes by router
2157 * advertisements, we SHOULD insure that a new random
2158 * value gets recomputed at least once every few hours.
2159 * (RFC 2461, 6.3.4)
2160 */
2161 nd6if->nd_recalc_timer = V_nd6_recalc_reachtm_interval;
2162 nd6if->nd_reachable =
2163 ND_COMPUTE_RTIME(nd6if->nd_basereachable);
2164 }
2165 }
2166 NET_EPOCH_EXIT(et);
2167 CURVNET_RESTORE();
2168 }
2169
2170 struct mbuf *
nd6_grab_holdchain(struct llentry * ln)2171 nd6_grab_holdchain(struct llentry *ln)
2172 {
2173 struct mbuf *chain;
2174
2175 LLE_WLOCK_ASSERT(ln);
2176
2177 chain = ln->la_hold;
2178 ln->la_hold = NULL;
2179 ln->la_numheld = 0;
2180
2181 if (ln->ln_state == ND6_LLINFO_STALE) {
2182 /*
2183 * The first time we send a packet to a
2184 * neighbor whose entry is STALE, we have
2185 * to change the state to DELAY and a sets
2186 * a timer to expire in DELAY_FIRST_PROBE_TIME
2187 * seconds to ensure do neighbor unreachability
2188 * detection on expiration.
2189 * (RFC 2461 7.3.3)
2190 */
2191 nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
2192 }
2193
2194 return (chain);
2195 }
2196
2197 int
nd6_output_ifp(struct ifnet * ifp,struct ifnet * origifp,struct mbuf * m,struct sockaddr_in6 * dst,struct route * ro)2198 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
2199 struct sockaddr_in6 *dst, struct route *ro)
2200 {
2201 int error;
2202 int ip6len;
2203 struct ip6_hdr *ip6;
2204 struct m_tag *mtag;
2205
2206 #ifdef MAC
2207 mac_netinet6_nd6_send(ifp, m);
2208 #endif
2209
2210 /*
2211 * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
2212 * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
2213 * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
2214 * to be diverted to user space. When re-injected into the kernel,
2215 * send_output() will directly dispatch them to the outgoing interface.
2216 */
2217 if (send_sendso_input_hook != NULL) {
2218 mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
2219 if (mtag != NULL) {
2220 ip6 = mtod(m, struct ip6_hdr *);
2221 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
2222 /* Use the SEND socket */
2223 error = send_sendso_input_hook(m, ifp, SND_OUT,
2224 ip6len);
2225 /* -1 == no app on SEND socket */
2226 if (error == 0 || error != -1)
2227 return (error);
2228 }
2229 }
2230
2231 m_clrprotoflags(m); /* Avoid confusing lower layers. */
2232 IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
2233 mtod(m, struct ip6_hdr *));
2234
2235 if ((ifp->if_flags & IFF_LOOPBACK) == 0)
2236 origifp = ifp;
2237
2238 error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
2239 return (error);
2240 }
2241
2242 /*
2243 * Lookup link headerfor @sa_dst address. Stores found
2244 * data in @desten buffer. Copy of lle ln_flags can be also
2245 * saved in @pflags if @pflags is non-NULL.
2246 *
2247 * If destination LLE does not exists or lle state modification
2248 * is required, call "slow" version.
2249 *
2250 * Return values:
2251 * - 0 on success (address copied to buffer).
2252 * - EWOULDBLOCK (no local error, but address is still unresolved)
2253 * - other errors (alloc failure, etc)
2254 */
2255 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)2256 nd6_resolve(struct ifnet *ifp, int gw_flags, struct mbuf *m,
2257 const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
2258 struct llentry **plle)
2259 {
2260 struct llentry *ln = NULL;
2261 const struct sockaddr_in6 *dst6;
2262
2263 NET_EPOCH_ASSERT();
2264
2265 if (pflags != NULL)
2266 *pflags = 0;
2267
2268 dst6 = (const struct sockaddr_in6 *)sa_dst;
2269
2270 /* discard the packet if IPv6 operation is disabled on the interface */
2271 if ((ifp->if_inet6->nd_flags & ND6_IFF_IFDISABLED)) {
2272 m_freem(m);
2273 return (ENETDOWN); /* better error? */
2274 }
2275
2276 if (m != NULL && m->m_flags & M_MCAST) {
2277 switch (ifp->if_type) {
2278 case IFT_ETHER:
2279 case IFT_L2VLAN:
2280 case IFT_BRIDGE:
2281 ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
2282 desten);
2283 return (0);
2284 default:
2285 m_freem(m);
2286 return (EAFNOSUPPORT);
2287 }
2288 }
2289
2290 int family = gw_flags >> 16;
2291 int lookup_flags = plle ? LLE_EXCLUSIVE : LLE_UNLOCKED;
2292 ln = nd6_lookup(&dst6->sin6_addr, LLE_SF(family, lookup_flags), ifp);
2293 if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
2294 /* Entry found, let's copy lle info */
2295 bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
2296 if (pflags != NULL)
2297 *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
2298 llentry_provide_feedback(ln);
2299 if (plle) {
2300 LLE_ADDREF(ln);
2301 *plle = ln;
2302 LLE_WUNLOCK(ln);
2303 }
2304 return (0);
2305 } else if (plle && ln)
2306 LLE_WUNLOCK(ln);
2307
2308 return (nd6_resolve_slow(ifp, family, 0, m, dst6, desten, pflags, plle));
2309 }
2310
2311 /*
2312 * Finds or creates a new llentry for @addr and @family.
2313 * Returns wlocked llentry or NULL.
2314 *
2315 *
2316 * Child LLEs.
2317 *
2318 * Do not have their own state machine (gets marked as static)
2319 * settimer bails out for child LLEs just in case.
2320 *
2321 * Locking order: parent lle gets locked first, chen goes the child.
2322 */
2323 static __noinline struct llentry *
nd6_get_llentry(struct ifnet * ifp,const struct in6_addr * addr,int family)2324 nd6_get_llentry(struct ifnet *ifp, const struct in6_addr *addr, int family)
2325 {
2326 struct llentry *child_lle = NULL;
2327 struct llentry *lle, *lle_tmp;
2328
2329 lle = nd6_alloc(addr, 0, ifp);
2330 if (lle != NULL && family != AF_INET6) {
2331 child_lle = nd6_alloc(addr, 0, ifp);
2332 if (child_lle == NULL) {
2333 lltable_free_entry(LLTABLE6(ifp), lle);
2334 return (NULL);
2335 }
2336 child_lle->r_family = family;
2337 child_lle->la_flags |= LLE_CHILD | LLE_STATIC;
2338 child_lle->ln_state = ND6_LLINFO_INCOMPLETE;
2339 }
2340
2341 if (lle == NULL) {
2342 char ip6buf[INET6_ADDRSTRLEN];
2343 log(LOG_DEBUG,
2344 "nd6_get_llentry: can't allocate llinfo for %s "
2345 "(ln=%p)\n",
2346 ip6_sprintf(ip6buf, addr), lle);
2347 return (NULL);
2348 }
2349
2350 LLTABLE_LOCK(LLTABLE6(ifp));
2351 LLE_WLOCK(lle);
2352 /* Prefer any existing entry over newly-created one */
2353 lle_tmp = nd6_lookup(addr, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
2354 if (lle_tmp == NULL)
2355 lltable_link_entry(LLTABLE6(ifp), lle);
2356 else {
2357 lltable_free_entry(LLTABLE6(ifp), lle);
2358 lle = lle_tmp;
2359 }
2360 if (child_lle != NULL) {
2361 /* Check if child lle for the same family exists */
2362 lle_tmp = llentry_lookup_family(lle, child_lle->r_family);
2363 LLE_WLOCK(child_lle);
2364 if (lle_tmp == NULL) {
2365 /* Attach */
2366 lltable_link_child_entry(lle, child_lle);
2367 } else {
2368 /* child lle already exists, free newly-created one */
2369 lltable_free_entry(LLTABLE6(ifp), child_lle);
2370 LLE_WLOCK(lle_tmp);
2371 child_lle = lle_tmp;
2372 }
2373 LLE_WUNLOCK(lle);
2374 lle = child_lle;
2375 }
2376 LLTABLE_UNLOCK(LLTABLE6(ifp));
2377 return (lle);
2378 }
2379
2380 /*
2381 * Do L2 address resolution for @sa_dst address. Stores found
2382 * address in @desten buffer. Copy of lle ln_flags can be also
2383 * saved in @pflags if @pflags is non-NULL.
2384 *
2385 * Heavy version.
2386 * Function assume that destination LLE does not exist,
2387 * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
2388 *
2389 * Set noinline to be dtrace-friendly
2390 */
2391 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)2392 nd6_resolve_slow(struct ifnet *ifp, int family, int flags, struct mbuf *m,
2393 const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
2394 struct llentry **plle)
2395 {
2396 struct llentry *lle = NULL;
2397 struct in6_addr *psrc, src;
2398 int send_ns, ll_len;
2399 char *lladdr;
2400
2401 NET_EPOCH_ASSERT();
2402
2403 /*
2404 * Address resolution or Neighbor Unreachability Detection
2405 * for the next hop.
2406 * At this point, the destination of the packet must be a unicast
2407 * or an anycast address(i.e. not a multicast).
2408 */
2409 lle = nd6_lookup(&dst->sin6_addr, LLE_SF(family, LLE_EXCLUSIVE), ifp);
2410 if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp)) {
2411 /*
2412 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2413 * the condition below is not very efficient. But we believe
2414 * it is tolerable, because this should be a rare case.
2415 */
2416 lle = nd6_get_llentry(ifp, &dst->sin6_addr, family);
2417 }
2418
2419 if (lle == NULL) {
2420 m_freem(m);
2421 return (ENOBUFS);
2422 }
2423
2424 LLE_WLOCK_ASSERT(lle);
2425
2426 /*
2427 * The first time we send a packet to a neighbor whose entry is
2428 * STALE, we have to change the state to DELAY and a sets a timer to
2429 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2430 * neighbor unreachability detection on expiration.
2431 * (RFC 2461 7.3.3)
2432 */
2433 if ((!(lle->la_flags & LLE_CHILD)) && (lle->ln_state == ND6_LLINFO_STALE))
2434 nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
2435
2436 /*
2437 * If the neighbor cache entry has a state other than INCOMPLETE
2438 * (i.e. its link-layer address is already resolved), just
2439 * send the packet.
2440 */
2441 if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
2442 if (flags & LLE_ADDRONLY) {
2443 lladdr = lle->ll_addr;
2444 ll_len = ifp->if_addrlen;
2445 } else {
2446 lladdr = lle->r_linkdata;
2447 ll_len = lle->r_hdrlen;
2448 }
2449 bcopy(lladdr, desten, ll_len);
2450 if (pflags != NULL)
2451 *pflags = lle->la_flags;
2452 if (plle) {
2453 LLE_ADDREF(lle);
2454 *plle = lle;
2455 }
2456 LLE_WUNLOCK(lle);
2457 return (0);
2458 }
2459
2460 /*
2461 * There is a neighbor cache entry, but no ethernet address
2462 * response yet. Append this latest packet to the end of the
2463 * packet queue in the mbuf. When it exceeds nd6_maxqueuelen,
2464 * the oldest packet in the queue will be removed.
2465 */
2466 if (m != NULL) {
2467 size_t dropped;
2468
2469 dropped = lltable_append_entry_queue(lle, m, V_nd6_maxqueuelen);
2470 ICMP6STAT_ADD(icp6s_dropped, dropped);
2471 }
2472
2473 /*
2474 * If there has been no NS for the neighbor after entering the
2475 * INCOMPLETE state, send the first solicitation.
2476 * Note that for newly-created lle la_asked will be 0,
2477 * so we will transition from ND6_LLINFO_NOSTATE to
2478 * ND6_LLINFO_INCOMPLETE state here.
2479 */
2480 psrc = NULL;
2481 send_ns = 0;
2482
2483 /* If we have child lle, switch to the parent to send NS */
2484 if (lle->la_flags & LLE_CHILD) {
2485 struct llentry *lle_parent = lle->lle_parent;
2486 LLE_WUNLOCK(lle);
2487 lle = lle_parent;
2488 LLE_WLOCK(lle);
2489 }
2490 if (lle->la_asked == 0) {
2491 lle->la_asked++;
2492 send_ns = 1;
2493 psrc = nd6_llinfo_get_holdsrc(lle, &src);
2494
2495 nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
2496 }
2497 LLE_WUNLOCK(lle);
2498 if (send_ns != 0)
2499 nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
2500
2501 return (EWOULDBLOCK);
2502 }
2503
2504 /*
2505 * Do L2 address resolution for @sa_dst address. Stores found
2506 * address in @desten buffer. Copy of lle ln_flags can be also
2507 * saved in @pflags if @pflags is non-NULL.
2508 *
2509 * Return values:
2510 * - 0 on success (address copied to buffer).
2511 * - EWOULDBLOCK (no local error, but address is still unresolved)
2512 * - other errors (alloc failure, etc)
2513 */
2514 int
nd6_resolve_addr(struct ifnet * ifp,int flags,const struct sockaddr * dst,char * desten,uint32_t * pflags)2515 nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
2516 char *desten, uint32_t *pflags)
2517 {
2518 int error;
2519
2520 flags |= LLE_ADDRONLY;
2521 error = nd6_resolve_slow(ifp, AF_INET6, flags, NULL,
2522 (const struct sockaddr_in6 *)dst, desten, pflags, NULL);
2523 return (error);
2524 }
2525
2526 int
nd6_flush_holdchain(struct ifnet * ifp,struct llentry * lle,struct mbuf * chain)2527 nd6_flush_holdchain(struct ifnet *ifp, struct llentry *lle, struct mbuf *chain)
2528 {
2529 struct mbuf *m, *m_head;
2530 struct sockaddr_in6 dst6;
2531 int error = 0;
2532
2533 NET_EPOCH_ASSERT();
2534
2535 struct route_in6 ro = {
2536 .ro_prepend = lle->r_linkdata,
2537 .ro_plen = lle->r_hdrlen,
2538 };
2539
2540 lltable_fill_sa_entry(lle, (struct sockaddr *)&dst6);
2541 m_head = chain;
2542
2543 while (m_head) {
2544 m = m_head;
2545 m_head = m_head->m_nextpkt;
2546 m->m_nextpkt = NULL;
2547 error = nd6_output_ifp(ifp, ifp, m, &dst6, (struct route *)&ro);
2548 }
2549
2550 /*
2551 * XXX
2552 * note that intermediate errors are blindly ignored
2553 */
2554 return (error);
2555 }
2556
2557 __noinline void
nd6_flush_children_holdchain(struct ifnet * ifp,struct llentry * lle)2558 nd6_flush_children_holdchain(struct ifnet *ifp, struct llentry *lle)
2559 {
2560 struct llentry *child_lle;
2561 struct mbuf *chain;
2562
2563 NET_EPOCH_ASSERT();
2564
2565 CK_SLIST_FOREACH(child_lle, &lle->lle_children, lle_child_next) {
2566 LLE_WLOCK(child_lle);
2567 chain = nd6_grab_holdchain(child_lle);
2568 LLE_WUNLOCK(child_lle);
2569 nd6_flush_holdchain(ifp, child_lle, chain);
2570 }
2571 }
2572
2573 static int
nd6_need_cache(struct ifnet * ifp)2574 nd6_need_cache(struct ifnet *ifp)
2575 {
2576 /*
2577 * XXX: we currently do not make neighbor cache on any interface
2578 * other than Ethernet and GIF.
2579 *
2580 * RFC2893 says:
2581 * - unidirectional tunnels needs no ND
2582 */
2583 switch (ifp->if_type) {
2584 case IFT_ETHER:
2585 case IFT_IEEE1394:
2586 case IFT_L2VLAN:
2587 case IFT_INFINIBAND:
2588 case IFT_BRIDGE:
2589 case IFT_PROPVIRTUAL:
2590 return (1);
2591 default:
2592 return (0);
2593 }
2594 }
2595
2596 /*
2597 * Add pernament ND6 link-layer record for given
2598 * interface address.
2599 *
2600 * Very similar to IPv4 arp_ifinit(), but:
2601 * 1) IPv6 DAD is performed in different place
2602 * 2) It is called by IPv6 protocol stack in contrast to
2603 * arp_ifinit() which is typically called in SIOCSIFADDR
2604 * driver ioctl handler.
2605 *
2606 */
2607 int
nd6_add_ifa_lle(struct in6_ifaddr * ia)2608 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2609 {
2610 struct ifnet *ifp;
2611 struct llentry *ln, *ln_tmp;
2612 struct sockaddr *dst;
2613
2614 ifp = ia->ia_ifa.ifa_ifp;
2615 if (nd6_need_cache(ifp) == 0)
2616 return (0);
2617
2618 dst = (struct sockaddr *)&ia->ia_addr;
2619 ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
2620 if (ln == NULL)
2621 return (ENOBUFS);
2622
2623 LLTABLE_LOCK(LLTABLE6(ifp));
2624 LLE_WLOCK(ln);
2625 /* Unlink any entry if exists */
2626 ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_SF(AF_INET6, LLE_EXCLUSIVE), dst);
2627 if (ln_tmp != NULL)
2628 lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
2629 lltable_link_entry(LLTABLE6(ifp), ln);
2630 LLTABLE_UNLOCK(LLTABLE6(ifp));
2631
2632 if (ln_tmp != NULL)
2633 EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
2634 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2635
2636 LLE_WUNLOCK(ln);
2637 if (ln_tmp != NULL)
2638 llentry_free(ln_tmp);
2639
2640 return (0);
2641 }
2642
2643 /*
2644 * Removes either all lle entries for given @ia, or lle
2645 * corresponding to @ia address.
2646 */
2647 void
nd6_rem_ifa_lle(struct in6_ifaddr * ia,int all)2648 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
2649 {
2650 struct sockaddr_in6 mask, addr;
2651 struct sockaddr *saddr, *smask;
2652 struct ifnet *ifp;
2653
2654 ifp = ia->ia_ifa.ifa_ifp;
2655 memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2656 memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2657 saddr = (struct sockaddr *)&addr;
2658 smask = (struct sockaddr *)&mask;
2659
2660 if (all != 0)
2661 lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
2662 else
2663 lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
2664 }
2665
2666 static int
nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)2667 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2668 {
2669 struct in6_prefix p;
2670 struct sockaddr_in6 s6;
2671 struct nd_prefix *pr;
2672 struct nd_pfxrouter *pfr;
2673 time_t maxexpire;
2674 int error;
2675 char ip6buf[INET6_ADDRSTRLEN];
2676
2677 if (req->newptr)
2678 return (EPERM);
2679
2680 error = sysctl_wire_old_buffer(req, 0);
2681 if (error != 0)
2682 return (error);
2683
2684 bzero(&p, sizeof(p));
2685 p.origin = PR_ORIG_RA;
2686 bzero(&s6, sizeof(s6));
2687 s6.sin6_family = AF_INET6;
2688 s6.sin6_len = sizeof(s6);
2689
2690 ND6_RLOCK();
2691 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
2692 p.prefix = pr->ndpr_prefix;
2693 if (sa6_recoverscope(&p.prefix)) {
2694 log(LOG_ERR, "scope error in prefix list (%s)\n",
2695 ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
2696 /* XXX: press on... */
2697 }
2698 p.raflags = pr->ndpr_raf;
2699 p.prefixlen = pr->ndpr_plen;
2700 p.vltime = pr->ndpr_vltime;
2701 p.pltime = pr->ndpr_pltime;
2702 p.if_index = pr->ndpr_ifp->if_index;
2703 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2704 p.expire = 0;
2705 else {
2706 /* XXX: we assume time_t is signed. */
2707 maxexpire = (-1) &
2708 ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
2709 if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
2710 p.expire = pr->ndpr_lastupdate +
2711 pr->ndpr_vltime +
2712 (time_second - time_uptime);
2713 else
2714 p.expire = maxexpire;
2715 }
2716 p.refcnt = pr->ndpr_addrcnt;
2717 p.flags = pr->ndpr_stateflags;
2718 p.advrtrs = 0;
2719 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2720 p.advrtrs++;
2721 error = SYSCTL_OUT(req, &p, sizeof(p));
2722 if (error != 0)
2723 break;
2724 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2725 s6.sin6_addr = pfr->router->rtaddr;
2726 if (sa6_recoverscope(&s6))
2727 log(LOG_ERR,
2728 "scope error in prefix list (%s)\n",
2729 ip6_sprintf(ip6buf, &pfr->router->rtaddr));
2730 error = SYSCTL_OUT(req, &s6, sizeof(s6));
2731 if (error != 0)
2732 goto out;
2733 }
2734 }
2735 out:
2736 ND6_RUNLOCK();
2737 return (error);
2738 }
2739 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2740 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
2741 NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
2742 "NDP prefix list");
2743 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
2744 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
2745 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
2746 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
2747