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 <sys/cdefs.h>
35 #include "opt_inet.h"
36 #include "opt_inet6.h"
37 #include "opt_route.h"
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/eventhandler.h>
42 #include <sys/callout.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/mutex.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
49 #include <sys/time.h>
50 #include <sys/kernel.h>
51 #include <sys/protosw.h>
52 #include <sys/errno.h>
53 #include <sys/syslog.h>
54 #include <sys/rwlock.h>
55 #include <sys/queue.h>
56 #include <sys/sdt.h>
57 #include <sys/sysctl.h>
58
59 #include <net/if.h>
60 #include <net/if_var.h>
61 #include <net/if_dl.h>
62 #include <net/if_private.h>
63 #include <net/if_types.h>
64 #include <net/route.h>
65 #include <net/route/route_ctl.h>
66 #include <net/route/nhop.h>
67 #include <net/vnet.h>
68
69 #include <netinet/in.h>
70 #include <netinet/in_kdtrace.h>
71 #include <net/if_llatbl.h>
72 #include <netinet/if_ether.h>
73 #include <netinet6/in6_fib.h>
74 #include <netinet6/in6_var.h>
75 #include <netinet/ip6.h>
76 #include <netinet6/ip6_var.h>
77 #include <netinet6/scope6_var.h>
78 #include <netinet6/nd6.h>
79 #include <netinet6/in6_ifattach.h>
80 #include <netinet/icmp6.h>
81 #include <netinet6/send.h>
82
83 #include <sys/limits.h>
84
85 #include <security/mac/mac_framework.h>
86
87 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
88 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
89
90 #define SIN6(s) ((const struct sockaddr_in6 *)(s))
91
92 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
93
94 VNET_DEFINE_STATIC(int, nd6_prune) = 1;
95 #define V_nd6_prune VNET(nd6_prune)
96 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_PRUNE, nd6_prune,
97 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_prune), 0,
98 "Frequency in seconds of checks for expired prefixes and routers");
99
100 VNET_DEFINE_STATIC(int, nd6_delay) = 5;
101 #define V_nd6_delay VNET(nd6_delay)
102 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DELAY, nd6_delay,
103 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_delay), 0,
104 "Delay in seconds before probing for reachability");
105
106 VNET_DEFINE_STATIC(int, nd6_umaxtries) = 3;
107 #define V_nd6_umaxtries VNET(nd6_umaxtries)
108 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_UMAXTRIES, nd6_umaxtries,
109 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_umaxtries), 0,
110 "Number of ICMPv6 NS messages sent during reachability detection");
111
112 VNET_DEFINE(int, nd6_mmaxtries) = 3;
113 #define V_nd6_mmaxtries VNET(nd6_mmaxtries)
114 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MMAXTRIES, nd6_mmaxtries,
115 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_mmaxtries), 0,
116 "Number of ICMPv6 NS messages sent during address resolution");
117
118 VNET_DEFINE_STATIC(int, nd6_gctimer) = (60 * 60 * 24); /* 1 day: garbage
119 * collection timer */
120 #define V_nd6_gctimer VNET(nd6_gctimer)
121
122 /* preventing too many loops in ND option parsing */
123 VNET_DEFINE_STATIC(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
124
125 VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 16; /* max pkts cached in unresolved
126 * ND entries */
127 #define V_nd6_maxndopt VNET(nd6_maxndopt)
128 #define V_nd6_maxqueuelen VNET(nd6_maxqueuelen)
129
130 #ifdef ND6_DEBUG
131 VNET_DEFINE(int, nd6_debug) = 1;
132 #else
133 VNET_DEFINE(int, nd6_debug) = 0;
134 #endif
135 #define V_nd6_debug VNET(nd6_debug)
136 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_DEBUG, nd6_debug,
137 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_debug), 0,
138 "Log NDP debug messages");
139
140 static eventhandler_tag lle_event_eh, iflladdr_event_eh, ifnet_link_event_eh;
141
142 VNET_DEFINE(struct nd_prhead, nd_prefix);
143 VNET_DEFINE(struct rwlock, nd6_lock);
144 VNET_DEFINE(uint64_t, nd6_list_genid);
145 VNET_DEFINE(struct mtx, nd6_onlink_mtx);
146
147 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
148 #define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
149
150 int (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
151
152 static bool nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
153 struct ifnet *);
154 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
155 static void nd6_slowtimo(void *);
156 static int regen_tmpaddr(struct in6_ifaddr *);
157 static void nd6_free(struct llentry **, int);
158 static void nd6_free_redirect(const struct llentry *);
159 static void nd6_llinfo_timer(void *);
160 static void nd6_llinfo_settimer_locked(struct llentry *, long);
161 static int nd6_resolve_slow(struct ifnet *, int, int, struct mbuf *,
162 const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
163 static int nd6_need_cache(struct ifnet *);
164
165 VNET_DEFINE_STATIC(struct callout, nd6_slowtimo_ch);
166 #define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch)
167
168 VNET_DEFINE_STATIC(struct callout, nd6_timer_ch);
169 #define V_nd6_timer_ch VNET(nd6_timer_ch)
170
171 static void
nd6_lle_event(void * arg __unused,struct llentry * lle,int evt)172 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
173 {
174 struct rt_addrinfo rtinfo;
175 struct sockaddr_in6 dst;
176 struct sockaddr_dl gw;
177 struct ifnet *ifp;
178 int type;
179 int fibnum;
180
181 LLE_WLOCK_ASSERT(lle);
182
183 if (lltable_get_af(lle->lle_tbl) != AF_INET6)
184 return;
185
186 switch (evt) {
187 case LLENTRY_RESOLVED:
188 type = RTM_ADD;
189 KASSERT(lle->la_flags & LLE_VALID,
190 ("%s: %p resolved but not valid?", __func__, lle));
191 break;
192 case LLENTRY_EXPIRED:
193 type = RTM_DELETE;
194 break;
195 default:
196 return;
197 }
198
199 ifp = lltable_get_ifp(lle->lle_tbl);
200
201 bzero(&dst, sizeof(dst));
202 bzero(&gw, sizeof(gw));
203 bzero(&rtinfo, sizeof(rtinfo));
204 lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
205 dst.sin6_scope_id = in6_getscopezone(ifp,
206 in6_addrscope(&dst.sin6_addr));
207 gw.sdl_len = sizeof(struct sockaddr_dl);
208 gw.sdl_family = AF_LINK;
209 gw.sdl_alen = ifp->if_addrlen;
210 gw.sdl_index = ifp->if_index;
211 gw.sdl_type = ifp->if_type;
212 if (evt == LLENTRY_RESOLVED)
213 bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
214 rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
215 rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
216 rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
217 fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib;
218 rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
219 type == RTM_ADD ? RTF_UP: 0), 0, fibnum);
220 }
221
222 /*
223 * A handler for interface link layer address change event.
224 */
225 static void
nd6_iflladdr(void * arg __unused,struct ifnet * ifp)226 nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
227 {
228 if (ifp->if_afdata[AF_INET6] == NULL)
229 return;
230
231 lltable_update_ifaddr(LLTABLE6(ifp));
232 }
233
234 void
nd6_init(void)235 nd6_init(void)
236 {
237
238 mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF);
239 rw_init(&V_nd6_lock, "nd6 list");
240
241 LIST_INIT(&V_nd_prefix);
242 nd6_defrouter_init();
243
244 /* Start timers. */
245 callout_init(&V_nd6_slowtimo_ch, 1);
246 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
247 nd6_slowtimo, curvnet);
248
249 callout_init(&V_nd6_timer_ch, 1);
250 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
251
252 nd6_dad_init();
253 if (IS_DEFAULT_VNET(curvnet)) {
254 lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
255 NULL, EVENTHANDLER_PRI_ANY);
256 iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
257 nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
258 ifnet_link_event_eh = EVENTHANDLER_REGISTER(ifnet_link_event,
259 nd6_ifnet_link_event, NULL, EVENTHANDLER_PRI_ANY);
260 }
261 }
262
263 #ifdef VIMAGE
264 void
nd6_destroy(void)265 nd6_destroy(void)
266 {
267
268 callout_drain(&V_nd6_slowtimo_ch);
269 callout_drain(&V_nd6_timer_ch);
270 if (IS_DEFAULT_VNET(curvnet)) {
271 EVENTHANDLER_DEREGISTER(ifnet_link_event, ifnet_link_event_eh);
272 EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
273 EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
274 }
275 rw_destroy(&V_nd6_lock);
276 mtx_destroy(&V_nd6_onlink_mtx);
277 }
278 #endif
279
280 struct nd_ifinfo *
nd6_ifattach(struct ifnet * ifp)281 nd6_ifattach(struct ifnet *ifp)
282 {
283 struct nd_ifinfo *nd;
284
285 nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
286 nd->initialized = 1;
287
288 nd->chlim = IPV6_DEFHLIM;
289 nd->basereachable = REACHABLE_TIME;
290 nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
291 nd->retrans = RETRANS_TIMER;
292
293 nd->flags = ND6_IFF_PERFORMNUD;
294
295 /* Set IPv6 disabled on all interfaces but loopback by default. */
296 if ((ifp->if_flags & IFF_LOOPBACK) == 0)
297 nd->flags |= ND6_IFF_IFDISABLED;
298
299 /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
300 * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
301 * default regardless of the V_ip6_auto_linklocal configuration to
302 * give a reasonable default behavior.
303 */
304 if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE &&
305 ifp->if_type != IFT_WIREGUARD) || (ifp->if_flags & IFF_LOOPBACK))
306 nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
307 /*
308 * A loopback interface does not need to accept RTADV.
309 * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
310 * default regardless of the V_ip6_accept_rtadv configuration to
311 * prevent the interface from accepting RA messages arrived
312 * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
313 */
314 if (V_ip6_accept_rtadv &&
315 !(ifp->if_flags & IFF_LOOPBACK) &&
316 (ifp->if_type != IFT_BRIDGE)) {
317 nd->flags |= ND6_IFF_ACCEPT_RTADV;
318 /* If we globally accept rtadv, assume IPv6 on. */
319 nd->flags &= ~ND6_IFF_IFDISABLED;
320 }
321 if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
322 nd->flags |= ND6_IFF_NO_RADR;
323
324 /* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
325 nd6_setmtu0(ifp, nd);
326
327 return nd;
328 }
329
330 void
nd6_ifdetach(struct ifnet * ifp,struct nd_ifinfo * nd)331 nd6_ifdetach(struct ifnet *ifp, struct nd_ifinfo *nd)
332 {
333 struct epoch_tracker et;
334 struct ifaddr *ifa, *next;
335
336 NET_EPOCH_ENTER(et);
337 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
338 if (ifa->ifa_addr->sa_family != AF_INET6)
339 continue;
340
341 /* stop DAD processing */
342 nd6_dad_stop(ifa);
343 }
344 NET_EPOCH_EXIT(et);
345
346 free(nd, M_IP6NDP);
347 }
348
349 /*
350 * Reset ND level link MTU. This function is called when the physical MTU
351 * changes, which means we might have to adjust the ND level MTU.
352 */
353 void
nd6_setmtu(struct ifnet * ifp)354 nd6_setmtu(struct ifnet *ifp)
355 {
356 if (ifp->if_afdata[AF_INET6] == NULL)
357 return;
358
359 nd6_setmtu0(ifp, ND_IFINFO(ifp));
360 }
361
362 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
363 void
nd6_setmtu0(struct ifnet * ifp,struct nd_ifinfo * ndi)364 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
365 {
366 u_int32_t omaxmtu;
367
368 omaxmtu = ndi->maxmtu;
369 ndi->maxmtu = ifp->if_mtu;
370
371 /*
372 * Decreasing the interface MTU under IPV6 minimum MTU may cause
373 * undesirable situation. We thus notify the operator of the change
374 * explicitly. The check for omaxmtu is necessary to restrict the
375 * log to the case of changing the MTU, not initializing it.
376 */
377 if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
378 log(LOG_NOTICE, "nd6_setmtu0: "
379 "new link MTU on %s (%lu) is too small for IPv6\n",
380 if_name(ifp), (unsigned long)ndi->maxmtu);
381 }
382
383 if (ndi->maxmtu > V_in6_maxmtu)
384 in6_setmaxmtu(); /* check all interfaces just in case */
385
386 }
387
388 void
nd6_option_init(void * opt,int icmp6len,union nd_opts * ndopts)389 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
390 {
391
392 bzero(ndopts, sizeof(*ndopts));
393 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
394 ndopts->nd_opts_last
395 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
396
397 if (icmp6len == 0) {
398 ndopts->nd_opts_done = 1;
399 ndopts->nd_opts_search = NULL;
400 }
401 }
402
403 /*
404 * Take one ND option.
405 */
406 struct nd_opt_hdr *
nd6_option(union nd_opts * ndopts)407 nd6_option(union nd_opts *ndopts)
408 {
409 struct nd_opt_hdr *nd_opt;
410 int olen;
411
412 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
413 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
414 __func__));
415 if (ndopts->nd_opts_search == NULL)
416 return NULL;
417 if (ndopts->nd_opts_done)
418 return NULL;
419
420 nd_opt = ndopts->nd_opts_search;
421
422 /* make sure nd_opt_len is inside the buffer */
423 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
424 bzero(ndopts, sizeof(*ndopts));
425 return NULL;
426 }
427
428 olen = nd_opt->nd_opt_len << 3;
429 if (olen == 0) {
430 /*
431 * Message validation requires that all included
432 * options have a length that is greater than zero.
433 */
434 bzero(ndopts, sizeof(*ndopts));
435 return NULL;
436 }
437
438 ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
439 if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
440 /* option overruns the end of buffer, invalid */
441 bzero(ndopts, sizeof(*ndopts));
442 return NULL;
443 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
444 /* reached the end of options chain */
445 ndopts->nd_opts_done = 1;
446 ndopts->nd_opts_search = NULL;
447 }
448 return nd_opt;
449 }
450
451 /*
452 * Parse multiple ND options.
453 * This function is much easier to use, for ND routines that do not need
454 * multiple options of the same type.
455 */
456 int
nd6_options(union nd_opts * ndopts)457 nd6_options(union nd_opts *ndopts)
458 {
459 struct nd_opt_hdr *nd_opt;
460 int i = 0;
461
462 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
463 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
464 __func__));
465 if (ndopts->nd_opts_search == NULL)
466 return 0;
467
468 while (1) {
469 nd_opt = nd6_option(ndopts);
470 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
471 /*
472 * Message validation requires that all included
473 * options have a length that is greater than zero.
474 */
475 ICMP6STAT_INC(icp6s_nd_badopt);
476 bzero(ndopts, sizeof(*ndopts));
477 return -1;
478 }
479
480 if (nd_opt == NULL)
481 goto skip1;
482
483 switch (nd_opt->nd_opt_type) {
484 case ND_OPT_SOURCE_LINKADDR:
485 case ND_OPT_TARGET_LINKADDR:
486 case ND_OPT_MTU:
487 case ND_OPT_REDIRECTED_HEADER:
488 case ND_OPT_NONCE:
489 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
490 nd6log((LOG_INFO,
491 "duplicated ND6 option found (type=%d)\n",
492 nd_opt->nd_opt_type));
493 /* XXX bark? */
494 } else {
495 ndopts->nd_opt_array[nd_opt->nd_opt_type]
496 = nd_opt;
497 }
498 break;
499 case ND_OPT_PREFIX_INFORMATION:
500 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
501 ndopts->nd_opt_array[nd_opt->nd_opt_type]
502 = nd_opt;
503 }
504 ndopts->nd_opts_pi_end =
505 (struct nd_opt_prefix_info *)nd_opt;
506 break;
507 /* What about ND_OPT_ROUTE_INFO? RFC 4191 */
508 case ND_OPT_RDNSS: /* RFC 6106 */
509 case ND_OPT_DNSSL: /* RFC 6106 */
510 /*
511 * Silently ignore options we know and do not care about
512 * in the kernel.
513 */
514 break;
515 default:
516 /*
517 * Unknown options must be silently ignored,
518 * to accommodate future extension to the protocol.
519 */
520 nd6log((LOG_DEBUG,
521 "nd6_options: unsupported option %d - "
522 "option ignored\n", nd_opt->nd_opt_type));
523 }
524
525 skip1:
526 i++;
527 if (i > V_nd6_maxndopt) {
528 ICMP6STAT_INC(icp6s_nd_toomanyopt);
529 nd6log((LOG_INFO, "too many loop in nd opt\n"));
530 break;
531 }
532
533 if (ndopts->nd_opts_done)
534 break;
535 }
536
537 return 0;
538 }
539
540 /*
541 * ND6 timer routine to handle ND6 entries
542 */
543 static void
nd6_llinfo_settimer_locked(struct llentry * ln,long tick)544 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
545 {
546 int canceled;
547
548 LLE_WLOCK_ASSERT(ln);
549
550 /* Do not schedule timers for child LLEs. */
551 if (ln->la_flags & LLE_CHILD)
552 return;
553
554 if (tick < 0) {
555 ln->la_expire = 0;
556 ln->ln_ntick = 0;
557 canceled = callout_stop(&ln->lle_timer);
558 } else {
559 ln->la_expire = time_uptime + tick / hz;
560 LLE_ADDREF(ln);
561 if (tick > INT_MAX) {
562 ln->ln_ntick = tick - INT_MAX;
563 canceled = callout_reset(&ln->lle_timer, INT_MAX,
564 nd6_llinfo_timer, ln);
565 } else {
566 ln->ln_ntick = 0;
567 canceled = callout_reset(&ln->lle_timer, tick,
568 nd6_llinfo_timer, ln);
569 }
570 }
571 if (canceled > 0)
572 LLE_REMREF(ln);
573 }
574
575 /*
576 * Gets source address of the first packet in hold queue
577 * and stores it in @src.
578 * Returns pointer to @src (if hold queue is not empty) or NULL.
579 *
580 * Set noinline to be dtrace-friendly
581 */
582 static __noinline struct in6_addr *
nd6_llinfo_get_holdsrc(struct llentry * ln,struct in6_addr * src)583 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
584 {
585 struct ip6_hdr hdr;
586 struct mbuf *m;
587
588 if (ln->la_hold == NULL)
589 return (NULL);
590
591 /*
592 * assume every packet in la_hold has the same IP header
593 */
594 m = ln->la_hold;
595 if (sizeof(hdr) > m->m_len)
596 return (NULL);
597
598 m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
599 *src = hdr.ip6_src;
600
601 return (src);
602 }
603
604 /*
605 * Checks if we need to switch from STALE state.
606 *
607 * RFC 4861 requires switching from STALE to DELAY state
608 * on first packet matching entry, waiting V_nd6_delay and
609 * transition to PROBE state (if upper layer confirmation was
610 * not received).
611 *
612 * This code performs a bit differently:
613 * On packet hit we don't change state (but desired state
614 * can be guessed by control plane). However, after V_nd6_delay
615 * seconds code will transition to PROBE state (so DELAY state
616 * is kinda skipped in most situations).
617 *
618 * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
619 * we perform the following upon entering STALE state:
620 *
621 * 1) Arm timer to run each V_nd6_delay seconds to make sure that
622 * if packet was transmitted at the start of given interval, we
623 * would be able to switch to PROBE state in V_nd6_delay seconds
624 * as user expects.
625 *
626 * 2) Reschedule timer until original V_nd6_gctimer expires keeping
627 * lle in STALE state (remaining timer value stored in lle_remtime).
628 *
629 * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
630 * seconds ago.
631 *
632 * Returns non-zero value if the entry is still STALE (storing
633 * the next timer interval in @pdelay).
634 *
635 * Returns zero value if original timer expired or we need to switch to
636 * PROBE (store that in @do_switch variable).
637 */
638 static int
nd6_is_stale(struct llentry * lle,long * pdelay,int * do_switch)639 nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
640 {
641 int nd_delay, nd_gctimer;
642 time_t lle_hittime;
643 long delay;
644
645 *do_switch = 0;
646 nd_gctimer = V_nd6_gctimer;
647 nd_delay = V_nd6_delay;
648
649 lle_hittime = llentry_get_hittime(lle);
650
651 if (lle_hittime == 0) {
652 /*
653 * Datapath feedback has been requested upon entering
654 * STALE state. No packets has been passed using this lle.
655 * Ask for the timer reschedule and keep STALE state.
656 */
657 delay = (long)(MIN(nd_gctimer, nd_delay));
658 delay *= hz;
659 if (lle->lle_remtime > delay)
660 lle->lle_remtime -= delay;
661 else {
662 delay = lle->lle_remtime;
663 lle->lle_remtime = 0;
664 }
665
666 if (delay == 0) {
667 /*
668 * The original ng6_gctime timeout ended,
669 * no more rescheduling.
670 */
671 return (0);
672 }
673
674 *pdelay = delay;
675 return (1);
676 }
677
678 /*
679 * Packet received. Verify timestamp
680 */
681 delay = (long)(time_uptime - lle_hittime);
682 if (delay < nd_delay) {
683 /*
684 * V_nd6_delay still not passed since the first
685 * hit in STALE state.
686 * Reschedule timer and return.
687 */
688 *pdelay = (long)(nd_delay - delay) * hz;
689 return (1);
690 }
691
692 /* Request switching to probe */
693 *do_switch = 1;
694 return (0);
695 }
696
697 /*
698 * Switch @lle state to new state optionally arming timers.
699 *
700 * Set noinline to be dtrace-friendly
701 */
702 __noinline void
nd6_llinfo_setstate(struct llentry * lle,int newstate)703 nd6_llinfo_setstate(struct llentry *lle, int newstate)
704 {
705 struct ifnet *ifp;
706 int nd_gctimer, nd_delay;
707 long delay, remtime;
708
709 delay = 0;
710 remtime = 0;
711
712 switch (newstate) {
713 case ND6_LLINFO_INCOMPLETE:
714 ifp = lle->lle_tbl->llt_ifp;
715 delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000;
716 break;
717 case ND6_LLINFO_REACHABLE:
718 if (!ND6_LLINFO_PERMANENT(lle)) {
719 ifp = lle->lle_tbl->llt_ifp;
720 delay = (long)ND_IFINFO(ifp)->reachable * hz;
721 }
722 break;
723 case ND6_LLINFO_STALE:
724
725 llentry_request_feedback(lle);
726 nd_delay = V_nd6_delay;
727 nd_gctimer = V_nd6_gctimer;
728
729 delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
730 remtime = (long)nd_gctimer * hz - delay;
731 break;
732 case ND6_LLINFO_DELAY:
733 lle->la_asked = 0;
734 delay = (long)V_nd6_delay * hz;
735 break;
736 }
737
738 if (delay > 0)
739 nd6_llinfo_settimer_locked(lle, delay);
740
741 lle->lle_remtime = remtime;
742 lle->ln_state = newstate;
743 }
744
745 /*
746 * Timer-dependent part of nd state machine.
747 *
748 * Set noinline to be dtrace-friendly
749 */
750 static __noinline void
nd6_llinfo_timer(void * arg)751 nd6_llinfo_timer(void *arg)
752 {
753 struct epoch_tracker et;
754 struct llentry *ln;
755 struct in6_addr *dst, *pdst, *psrc, src;
756 struct ifnet *ifp;
757 struct nd_ifinfo *ndi;
758 int do_switch, send_ns;
759 long delay;
760
761 KASSERT(arg != NULL, ("%s: arg NULL", __func__));
762 ln = (struct llentry *)arg;
763 ifp = lltable_get_ifp(ln->lle_tbl);
764 CURVNET_SET(ifp->if_vnet);
765
766 ND6_RLOCK();
767 LLE_WLOCK(ln);
768 if (callout_pending(&ln->lle_timer)) {
769 /*
770 * Here we are a bit odd here in the treatment of
771 * active/pending. If the pending bit is set, it got
772 * rescheduled before I ran. The active
773 * bit we ignore, since if it was stopped
774 * in ll_tablefree() and was currently running
775 * it would have return 0 so the code would
776 * not have deleted it since the callout could
777 * not be stopped so we want to go through
778 * with the delete here now. If the callout
779 * was restarted, the pending bit will be back on and
780 * we just want to bail since the callout_reset would
781 * return 1 and our reference would have been removed
782 * by nd6_llinfo_settimer_locked above since canceled
783 * would have been 1.
784 */
785 LLE_WUNLOCK(ln);
786 ND6_RUNLOCK();
787 CURVNET_RESTORE();
788 return;
789 }
790 NET_EPOCH_ENTER(et);
791 ndi = ND_IFINFO(ifp);
792 send_ns = 0;
793 dst = &ln->r_l3addr.addr6;
794 pdst = dst;
795
796 if (ln->ln_ntick > 0) {
797 if (ln->ln_ntick > INT_MAX) {
798 ln->ln_ntick -= INT_MAX;
799 nd6_llinfo_settimer_locked(ln, INT_MAX);
800 } else {
801 ln->ln_ntick = 0;
802 nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
803 }
804 goto done;
805 }
806
807 if (ln->la_flags & LLE_STATIC) {
808 goto done;
809 }
810
811 if (ln->la_flags & LLE_DELETED) {
812 nd6_free(&ln, 0);
813 goto done;
814 }
815
816 switch (ln->ln_state) {
817 case ND6_LLINFO_INCOMPLETE:
818 if (ln->la_asked < V_nd6_mmaxtries) {
819 ln->la_asked++;
820 send_ns = 1;
821 /* Send NS to multicast address */
822 pdst = NULL;
823 } else {
824 struct mbuf *m;
825
826 ICMP6STAT_ADD(icp6s_dropped, ln->la_numheld);
827
828 m = ln->la_hold;
829 if (m != NULL) {
830 /*
831 * assuming every packet in la_hold has the
832 * same IP header. Send error after unlock.
833 */
834 ln->la_hold = m->m_nextpkt;
835 m->m_nextpkt = NULL;
836 ln->la_numheld--;
837 }
838 nd6_free(&ln, 0);
839 if (m != NULL) {
840 struct mbuf *n = m;
841
842 /*
843 * if there are any ummapped mbufs, we
844 * must free them, rather than using
845 * them for an ICMP, as they cannot be
846 * checksummed.
847 */
848 while ((n = n->m_next) != NULL) {
849 if (n->m_flags & M_EXTPG)
850 break;
851 }
852 if (n != NULL) {
853 m_freem(m);
854 m = NULL;
855 } else {
856 icmp6_error2(m, ICMP6_DST_UNREACH,
857 ICMP6_DST_UNREACH_ADDR, 0, ifp);
858 }
859 }
860 }
861 break;
862 case ND6_LLINFO_REACHABLE:
863 if (!ND6_LLINFO_PERMANENT(ln))
864 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
865 break;
866
867 case ND6_LLINFO_STALE:
868 if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
869 /*
870 * No packet has used this entry and GC timeout
871 * has not been passed. Reschedule timer and
872 * return.
873 */
874 nd6_llinfo_settimer_locked(ln, delay);
875 break;
876 }
877
878 if (do_switch == 0) {
879 /*
880 * GC timer has ended and entry hasn't been used.
881 * Run Garbage collector (RFC 4861, 5.3)
882 */
883 if (!ND6_LLINFO_PERMANENT(ln))
884 nd6_free(&ln, 1);
885 break;
886 }
887
888 /* Entry has been used AND delay timer has ended. */
889
890 /* FALLTHROUGH */
891
892 case ND6_LLINFO_DELAY:
893 if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
894 /* We need NUD */
895 ln->la_asked = 1;
896 nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
897 send_ns = 1;
898 } else
899 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
900 break;
901 case ND6_LLINFO_PROBE:
902 if (ln->la_asked < V_nd6_umaxtries) {
903 ln->la_asked++;
904 send_ns = 1;
905 } else {
906 nd6_free(&ln, 0);
907 }
908 break;
909 default:
910 panic("%s: paths in a dark night can be confusing: %d",
911 __func__, ln->ln_state);
912 }
913 done:
914 if (ln != NULL)
915 ND6_RUNLOCK();
916 if (send_ns != 0) {
917 nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
918 psrc = nd6_llinfo_get_holdsrc(ln, &src);
919 LLE_FREE_LOCKED(ln);
920 ln = NULL;
921 nd6_ns_output(ifp, psrc, pdst, dst, NULL);
922 }
923
924 if (ln != NULL)
925 LLE_FREE_LOCKED(ln);
926 NET_EPOCH_EXIT(et);
927 CURVNET_RESTORE();
928 }
929
930 /*
931 * ND6 timer routine to expire default route list and prefix list
932 */
933 void
nd6_timer(void * arg)934 nd6_timer(void *arg)
935 {
936 CURVNET_SET((struct vnet *) arg);
937 struct epoch_tracker et;
938 struct nd_prhead prl;
939 struct nd_prefix *pr, *npr;
940 struct ifnet *ifp;
941 struct in6_ifaddr *ia6, *nia6;
942 uint64_t genid;
943
944 LIST_INIT(&prl);
945
946 NET_EPOCH_ENTER(et);
947 nd6_defrouter_timer();
948
949 /*
950 * expire interface addresses.
951 * in the past the loop was inside prefix expiry processing.
952 * However, from a stricter speci-confrmance standpoint, we should
953 * rather separate address lifetimes and prefix lifetimes.
954 *
955 * XXXRW: in6_ifaddrhead locking.
956 */
957 addrloop:
958 CK_STAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
959 /* check address lifetime */
960 if (IFA6_IS_INVALID(ia6)) {
961 int regen = 0;
962
963 /*
964 * If the expiring address is temporary, try
965 * regenerating a new one. This would be useful when
966 * we suspended a laptop PC, then turned it on after a
967 * period that could invalidate all temporary
968 * addresses. Although we may have to restart the
969 * loop (see below), it must be after purging the
970 * address. Otherwise, we'd see an infinite loop of
971 * regeneration.
972 */
973 if (V_ip6_use_tempaddr &&
974 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
975 if (regen_tmpaddr(ia6) == 0)
976 regen = 1;
977 }
978
979 in6_purgeaddr(&ia6->ia_ifa);
980
981 if (regen)
982 goto addrloop; /* XXX: see below */
983 } else if (IFA6_IS_DEPRECATED(ia6)) {
984 int oldflags = ia6->ia6_flags;
985
986 ia6->ia6_flags |= IN6_IFF_DEPRECATED;
987
988 /*
989 * If a temporary address has just become deprecated,
990 * regenerate a new one if possible.
991 */
992 if (V_ip6_use_tempaddr &&
993 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
994 (oldflags & IN6_IFF_DEPRECATED) == 0) {
995 if (regen_tmpaddr(ia6) == 0) {
996 /*
997 * A new temporary address is
998 * generated.
999 * XXX: this means the address chain
1000 * has changed while we are still in
1001 * the loop. Although the change
1002 * would not cause disaster (because
1003 * it's not a deletion, but an
1004 * addition,) we'd rather restart the
1005 * loop just for safety. Or does this
1006 * significantly reduce performance??
1007 */
1008 goto addrloop;
1009 }
1010 }
1011 } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
1012 /*
1013 * Schedule DAD for a tentative address. This happens
1014 * if the interface was down or not running
1015 * when the address was configured.
1016 */
1017 int delay;
1018
1019 delay = arc4random() %
1020 (MAX_RTR_SOLICITATION_DELAY * hz);
1021 nd6_dad_start((struct ifaddr *)ia6, delay);
1022 } else {
1023 /*
1024 * Check status of the interface. If it is down,
1025 * mark the address as tentative for future DAD.
1026 */
1027 ifp = ia6->ia_ifp;
1028 if ((ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0 &&
1029 ((ifp->if_flags & IFF_UP) == 0 ||
1030 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1031 (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0)){
1032 ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
1033 ia6->ia6_flags |= IN6_IFF_TENTATIVE;
1034 }
1035
1036 /*
1037 * A new RA might have made a deprecated address
1038 * preferred.
1039 */
1040 ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
1041 }
1042 }
1043 NET_EPOCH_EXIT(et);
1044
1045 ND6_WLOCK();
1046 restart:
1047 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1048 /*
1049 * Expire prefixes. Since the pltime is only used for
1050 * autoconfigured addresses, pltime processing for prefixes is
1051 * not necessary.
1052 *
1053 * Only unlink after all derived addresses have expired. This
1054 * may not occur until two hours after the prefix has expired
1055 * per RFC 4862. If the prefix expires before its derived
1056 * addresses, mark it off-link. This will be done automatically
1057 * after unlinking if no address references remain.
1058 */
1059 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME ||
1060 time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime)
1061 continue;
1062
1063 if (pr->ndpr_addrcnt == 0) {
1064 nd6_prefix_unlink(pr, &prl);
1065 continue;
1066 }
1067 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1068 genid = V_nd6_list_genid;
1069 nd6_prefix_ref(pr);
1070 ND6_WUNLOCK();
1071 ND6_ONLINK_LOCK();
1072 (void)nd6_prefix_offlink(pr);
1073 ND6_ONLINK_UNLOCK();
1074 ND6_WLOCK();
1075 nd6_prefix_rele(pr);
1076 if (genid != V_nd6_list_genid)
1077 goto restart;
1078 }
1079 }
1080 ND6_WUNLOCK();
1081
1082 while ((pr = LIST_FIRST(&prl)) != NULL) {
1083 LIST_REMOVE(pr, ndpr_entry);
1084 nd6_prefix_del(pr);
1085 }
1086
1087 callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
1088 nd6_timer, curvnet);
1089
1090 CURVNET_RESTORE();
1091 }
1092
1093 /*
1094 * ia6 - deprecated/invalidated temporary address
1095 */
1096 static int
regen_tmpaddr(struct in6_ifaddr * ia6)1097 regen_tmpaddr(struct in6_ifaddr *ia6)
1098 {
1099 struct ifaddr *ifa;
1100 struct ifnet *ifp;
1101 struct in6_ifaddr *public_ifa6 = NULL;
1102
1103 NET_EPOCH_ASSERT();
1104
1105 ifp = ia6->ia_ifa.ifa_ifp;
1106 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1107 struct in6_ifaddr *it6;
1108
1109 if (ifa->ifa_addr->sa_family != AF_INET6)
1110 continue;
1111
1112 it6 = (struct in6_ifaddr *)ifa;
1113
1114 /* ignore no autoconf addresses. */
1115 if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1116 continue;
1117
1118 /* ignore autoconf addresses with different prefixes. */
1119 if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
1120 continue;
1121
1122 /*
1123 * Now we are looking at an autoconf address with the same
1124 * prefix as ours. If the address is temporary and is still
1125 * preferred, do not create another one. It would be rare, but
1126 * could happen, for example, when we resume a laptop PC after
1127 * a long period.
1128 */
1129 if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1130 !IFA6_IS_DEPRECATED(it6)) {
1131 public_ifa6 = NULL;
1132 break;
1133 }
1134
1135 /*
1136 * This is a public autoconf address that has the same prefix
1137 * as ours. If it is preferred, keep it. We can't break the
1138 * loop here, because there may be a still-preferred temporary
1139 * address with the prefix.
1140 */
1141 if (!IFA6_IS_DEPRECATED(it6))
1142 public_ifa6 = it6;
1143 }
1144 if (public_ifa6 != NULL)
1145 ifa_ref(&public_ifa6->ia_ifa);
1146
1147 if (public_ifa6 != NULL) {
1148 int e;
1149
1150 if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
1151 ifa_free(&public_ifa6->ia_ifa);
1152 log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
1153 " tmp addr,errno=%d\n", e);
1154 return (-1);
1155 }
1156 ifa_free(&public_ifa6->ia_ifa);
1157 return (0);
1158 }
1159
1160 return (-1);
1161 }
1162
1163 /*
1164 * Remove prefix and default router list entries corresponding to ifp. Neighbor
1165 * cache entries are freed in in6_domifdetach().
1166 */
1167 void
nd6_purge(struct ifnet * ifp)1168 nd6_purge(struct ifnet *ifp)
1169 {
1170 struct nd_prhead prl;
1171 struct nd_prefix *pr, *npr;
1172
1173 LIST_INIT(&prl);
1174
1175 /* Purge default router list entries toward ifp. */
1176 nd6_defrouter_purge(ifp);
1177
1178 ND6_WLOCK();
1179 /*
1180 * Remove prefixes on ifp. We should have already removed addresses on
1181 * this interface, so no addresses should be referencing these prefixes.
1182 */
1183 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1184 if (pr->ndpr_ifp == ifp)
1185 nd6_prefix_unlink(pr, &prl);
1186 }
1187 ND6_WUNLOCK();
1188
1189 /* Delete the unlinked prefix objects. */
1190 while ((pr = LIST_FIRST(&prl)) != NULL) {
1191 LIST_REMOVE(pr, ndpr_entry);
1192 nd6_prefix_del(pr);
1193 }
1194
1195 /* cancel default outgoing interface setting */
1196 if (V_nd6_defifindex == ifp->if_index)
1197 nd6_setdefaultiface(0);
1198
1199 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1200 /* Refresh default router list. */
1201 defrouter_select_fib(ifp->if_fib);
1202 }
1203 }
1204
1205 /*
1206 * the caller acquires and releases the lock on the lltbls
1207 * Returns the llentry locked
1208 */
1209 struct llentry *
nd6_lookup(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1210 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1211 {
1212 struct sockaddr_in6 sin6;
1213 struct llentry *ln;
1214
1215 bzero(&sin6, sizeof(sin6));
1216 sin6.sin6_len = sizeof(struct sockaddr_in6);
1217 sin6.sin6_family = AF_INET6;
1218 sin6.sin6_addr = *addr6;
1219
1220 IF_AFDATA_LOCK_ASSERT(ifp);
1221
1222 ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
1223
1224 return (ln);
1225 }
1226
1227 static struct llentry *
nd6_alloc(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1228 nd6_alloc(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 ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
1239 if (ln != NULL)
1240 ln->ln_state = ND6_LLINFO_NOSTATE;
1241
1242 return (ln);
1243 }
1244
1245 /*
1246 * Test whether a given IPv6 address can be a neighbor.
1247 */
1248 static bool
nd6_is_new_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1249 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1250 {
1251
1252 /*
1253 * A link-local address is always a neighbor.
1254 * XXX: a link does not necessarily specify a single interface.
1255 */
1256 if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
1257 struct sockaddr_in6 sin6_copy;
1258 u_int32_t zone;
1259
1260 /*
1261 * We need sin6_copy since sa6_recoverscope() may modify the
1262 * content (XXX).
1263 */
1264 sin6_copy = *addr;
1265 if (sa6_recoverscope(&sin6_copy))
1266 return (0); /* XXX: should be impossible */
1267 if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
1268 return (0);
1269 if (sin6_copy.sin6_scope_id == zone)
1270 return (1);
1271 else
1272 return (0);
1273 }
1274 /* Checking global unicast */
1275
1276 /* If an address is directly reachable, it is a neigbor */
1277 struct nhop_object *nh;
1278 nh = fib6_lookup(ifp->if_fib, &addr->sin6_addr, 0, NHR_NONE, 0);
1279 if (nh != NULL && nh->nh_aifp == ifp && (nh->nh_flags & NHF_GATEWAY) == 0)
1280 return (true);
1281
1282 /*
1283 * Check prefixes with desired on-link state, as some may be not
1284 * installed in the routing table.
1285 */
1286 bool matched = false;
1287 struct nd_prefix *pr;
1288 ND6_RLOCK();
1289 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1290 if (pr->ndpr_ifp != ifp)
1291 continue;
1292 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0)
1293 continue;
1294 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1295 &addr->sin6_addr, &pr->ndpr_mask)) {
1296 matched = true;
1297 break;
1298 }
1299 }
1300 ND6_RUNLOCK();
1301 if (matched)
1302 return (true);
1303
1304 /*
1305 * If the address is assigned on the node of the other side of
1306 * a p2p interface, the address should be a neighbor.
1307 */
1308 if (ifp->if_flags & IFF_POINTOPOINT) {
1309 struct ifaddr *ifa;
1310
1311 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1312 if (ifa->ifa_addr->sa_family != addr->sin6_family)
1313 continue;
1314 if (ifa->ifa_dstaddr != NULL &&
1315 sa_equal(addr, ifa->ifa_dstaddr)) {
1316 return (true);
1317 }
1318 }
1319 }
1320
1321 /*
1322 * If the default router list is empty, all addresses are regarded
1323 * as on-link, and thus, as a neighbor.
1324 */
1325 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
1326 nd6_defrouter_list_empty() &&
1327 V_nd6_defifindex == ifp->if_index) {
1328 return (1);
1329 }
1330
1331 return (0);
1332 }
1333
1334 /*
1335 * Detect if a given IPv6 address identifies a neighbor on a given link.
1336 * XXX: should take care of the destination of a p2p link?
1337 */
1338 int
nd6_is_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1339 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1340 {
1341 struct llentry *lle;
1342 int rc = 0;
1343
1344 NET_EPOCH_ASSERT();
1345 IF_AFDATA_UNLOCK_ASSERT(ifp);
1346 if (nd6_is_new_addr_neighbor(addr, ifp))
1347 return (1);
1348
1349 /*
1350 * Even if the address matches none of our addresses, it might be
1351 * in the neighbor cache.
1352 */
1353 if ((lle = nd6_lookup(&addr->sin6_addr, LLE_SF(AF_INET6, 0), ifp)) != NULL) {
1354 LLE_RUNLOCK(lle);
1355 rc = 1;
1356 }
1357 return (rc);
1358 }
1359
1360 static __noinline void
nd6_free_children(struct llentry * lle)1361 nd6_free_children(struct llentry *lle)
1362 {
1363 struct llentry *child_lle;
1364
1365 NET_EPOCH_ASSERT();
1366 LLE_WLOCK_ASSERT(lle);
1367
1368 while ((child_lle = CK_SLIST_FIRST(&lle->lle_children)) != NULL) {
1369 LLE_WLOCK(child_lle);
1370 lltable_unlink_child_entry(child_lle);
1371 llentry_free(child_lle);
1372 }
1373 }
1374
1375 /*
1376 * Tries to update @lle address/prepend data with new @lladdr.
1377 *
1378 * Returns true on success.
1379 * In any case, @lle is returned wlocked.
1380 */
1381 static __noinline bool
nd6_try_set_entry_addr_locked(struct ifnet * ifp,struct llentry * lle,char * lladdr)1382 nd6_try_set_entry_addr_locked(struct ifnet *ifp, struct llentry *lle, char *lladdr)
1383 {
1384 u_char buf[LLE_MAX_LINKHDR];
1385 int fam, off;
1386 size_t sz;
1387
1388 sz = sizeof(buf);
1389 if (lltable_calc_llheader(ifp, AF_INET6, lladdr, buf, &sz, &off) != 0)
1390 return (false);
1391
1392 /* Update data */
1393 lltable_set_entry_addr(ifp, lle, buf, sz, off);
1394
1395 struct llentry *child_lle;
1396 CK_SLIST_FOREACH(child_lle, &lle->lle_children, lle_child_next) {
1397 LLE_WLOCK(child_lle);
1398 fam = child_lle->r_family;
1399 sz = sizeof(buf);
1400 if (lltable_calc_llheader(ifp, fam, lladdr, buf, &sz, &off) == 0) {
1401 /* success */
1402 lltable_set_entry_addr(ifp, child_lle, buf, sz, off);
1403 child_lle->ln_state = ND6_LLINFO_REACHABLE;
1404 }
1405 LLE_WUNLOCK(child_lle);
1406 }
1407
1408 return (true);
1409 }
1410
1411 bool
nd6_try_set_entry_addr(struct ifnet * ifp,struct llentry * lle,char * lladdr)1412 nd6_try_set_entry_addr(struct ifnet *ifp, struct llentry *lle, char *lladdr)
1413 {
1414 NET_EPOCH_ASSERT();
1415 LLE_WLOCK_ASSERT(lle);
1416
1417 if (!lltable_acquire_wlock(ifp, lle))
1418 return (false);
1419 bool ret = nd6_try_set_entry_addr_locked(ifp, lle, lladdr);
1420 IF_AFDATA_WUNLOCK(ifp);
1421
1422 return (ret);
1423 }
1424
1425 /*
1426 * Free an nd6 llinfo entry.
1427 * Since the function would cause significant changes in the kernel, DO NOT
1428 * make it global, unless you have a strong reason for the change, and are sure
1429 * that the change is safe.
1430 *
1431 * Set noinline to be dtrace-friendly
1432 */
1433 static __noinline void
nd6_free(struct llentry ** lnp,int gc)1434 nd6_free(struct llentry **lnp, int gc)
1435 {
1436 struct ifnet *ifp;
1437 struct llentry *ln;
1438 struct nd_defrouter *dr;
1439
1440 ln = *lnp;
1441 *lnp = NULL;
1442
1443 LLE_WLOCK_ASSERT(ln);
1444 ND6_RLOCK_ASSERT();
1445
1446 KASSERT((ln->la_flags & LLE_CHILD) == 0, ("child lle"));
1447
1448 ifp = lltable_get_ifp(ln->lle_tbl);
1449 if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0)
1450 dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
1451 else
1452 dr = NULL;
1453 ND6_RUNLOCK();
1454
1455 if ((ln->la_flags & LLE_DELETED) == 0)
1456 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
1457
1458 /*
1459 * we used to have pfctlinput(PRC_HOSTDEAD) here.
1460 * even though it is not harmful, it was not really necessary.
1461 */
1462
1463 /* cancel timer */
1464 nd6_llinfo_settimer_locked(ln, -1);
1465
1466 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1467 if (dr != NULL && dr->expire &&
1468 ln->ln_state == ND6_LLINFO_STALE && gc) {
1469 /*
1470 * If the reason for the deletion is just garbage
1471 * collection, and the neighbor is an active default
1472 * router, do not delete it. Instead, reset the GC
1473 * timer using the router's lifetime.
1474 * Simply deleting the entry would affect default
1475 * router selection, which is not necessarily a good
1476 * thing, especially when we're using router preference
1477 * values.
1478 * XXX: the check for ln_state would be redundant,
1479 * but we intentionally keep it just in case.
1480 */
1481 if (dr->expire > time_uptime)
1482 nd6_llinfo_settimer_locked(ln,
1483 (dr->expire - time_uptime) * hz);
1484 else
1485 nd6_llinfo_settimer_locked(ln,
1486 (long)V_nd6_gctimer * hz);
1487
1488 LLE_REMREF(ln);
1489 LLE_WUNLOCK(ln);
1490 defrouter_rele(dr);
1491 return;
1492 }
1493
1494 if (dr) {
1495 /*
1496 * Unreachability of a router might affect the default
1497 * router selection and on-link detection of advertised
1498 * prefixes.
1499 */
1500
1501 /*
1502 * Temporarily fake the state to choose a new default
1503 * router and to perform on-link determination of
1504 * prefixes correctly.
1505 * Below the state will be set correctly,
1506 * or the entry itself will be deleted.
1507 */
1508 ln->ln_state = ND6_LLINFO_INCOMPLETE;
1509 }
1510
1511 if (ln->ln_router || dr) {
1512 /*
1513 * We need to unlock to avoid a LOR with rt6_flush() with the
1514 * rnh and for the calls to pfxlist_onlink_check() and
1515 * defrouter_select_fib() in the block further down for calls
1516 * into nd6_lookup(). We still hold a ref.
1517 */
1518 LLE_WUNLOCK(ln);
1519
1520 /*
1521 * rt6_flush must be called whether or not the neighbor
1522 * is in the Default Router List.
1523 * See a corresponding comment in nd6_na_input().
1524 */
1525 rt6_flush(&ln->r_l3addr.addr6, ifp);
1526 }
1527
1528 if (dr) {
1529 /*
1530 * Since defrouter_select_fib() does not affect the
1531 * on-link determination and MIP6 needs the check
1532 * before the default router selection, we perform
1533 * the check now.
1534 */
1535 pfxlist_onlink_check();
1536
1537 /*
1538 * Refresh default router list.
1539 */
1540 defrouter_select_fib(dr->ifp->if_fib);
1541 }
1542
1543 /*
1544 * If this entry was added by an on-link redirect, remove the
1545 * corresponding host route.
1546 */
1547 if (ln->la_flags & LLE_REDIRECT)
1548 nd6_free_redirect(ln);
1549
1550 if (ln->ln_router || dr)
1551 LLE_WLOCK(ln);
1552 }
1553
1554 /*
1555 * Save to unlock. We still hold an extra reference and will not
1556 * free(9) in llentry_free() if someone else holds one as well.
1557 */
1558 LLE_WUNLOCK(ln);
1559 IF_AFDATA_LOCK(ifp);
1560 LLE_WLOCK(ln);
1561 /* Guard against race with other llentry_free(). */
1562 if (ln->la_flags & LLE_LINKED) {
1563 /* Remove callout reference */
1564 LLE_REMREF(ln);
1565 lltable_unlink_entry(ln->lle_tbl, ln);
1566 }
1567 IF_AFDATA_UNLOCK(ifp);
1568
1569 nd6_free_children(ln);
1570
1571 llentry_free(ln);
1572 if (dr != NULL)
1573 defrouter_rele(dr);
1574 }
1575
1576 static int
nd6_isdynrte(const struct rtentry * rt,const struct nhop_object * nh,void * xap)1577 nd6_isdynrte(const struct rtentry *rt, const struct nhop_object *nh, void *xap)
1578 {
1579
1580 if (nh->nh_flags & NHF_REDIRECT)
1581 return (1);
1582
1583 return (0);
1584 }
1585
1586 /*
1587 * Remove the rtentry for the given llentry,
1588 * both of which were installed by a redirect.
1589 */
1590 static void
nd6_free_redirect(const struct llentry * ln)1591 nd6_free_redirect(const struct llentry *ln)
1592 {
1593 int fibnum;
1594 struct sockaddr_in6 sin6;
1595 struct rib_cmd_info rc;
1596 struct epoch_tracker et;
1597
1598 lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
1599
1600 NET_EPOCH_ENTER(et);
1601 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
1602 rib_del_route_px(fibnum, (struct sockaddr *)&sin6, 128,
1603 nd6_isdynrte, NULL, 0, &rc);
1604 NET_EPOCH_EXIT(et);
1605 }
1606
1607 /*
1608 * Updates status of the default router route.
1609 */
1610 static void
check_release_defrouter(const struct rib_cmd_info * rc,void * _cbdata)1611 check_release_defrouter(const struct rib_cmd_info *rc, void *_cbdata)
1612 {
1613 struct nd_defrouter *dr;
1614 struct nhop_object *nh;
1615
1616 nh = rc->rc_nh_old;
1617
1618 if ((nh != NULL) && (nh->nh_flags & NHF_DEFAULT)) {
1619 dr = defrouter_lookup(&nh->gw6_sa.sin6_addr, nh->nh_ifp);
1620 if (dr != NULL) {
1621 dr->installed = 0;
1622 defrouter_rele(dr);
1623 }
1624 }
1625 }
1626
1627 void
nd6_subscription_cb(struct rib_head * rnh,struct rib_cmd_info * rc,void * arg)1628 nd6_subscription_cb(struct rib_head *rnh, struct rib_cmd_info *rc, void *arg)
1629 {
1630
1631 #ifdef ROUTE_MPATH
1632 rib_decompose_notification(rc, check_release_defrouter, NULL);
1633 #else
1634 check_release_defrouter(rc, NULL);
1635 #endif
1636 }
1637
1638 int
nd6_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp)1639 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
1640 {
1641 struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1642 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1643 struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1644 struct epoch_tracker et;
1645 int error = 0;
1646
1647 if (ifp->if_afdata[AF_INET6] == NULL)
1648 return (EPFNOSUPPORT);
1649 switch (cmd) {
1650 case OSIOCGIFINFO_IN6:
1651 #define ND ndi->ndi
1652 /* XXX: old ndp(8) assumes a positive value for linkmtu. */
1653 bzero(&ND, sizeof(ND));
1654 ND.linkmtu = IN6_LINKMTU(ifp);
1655 ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
1656 ND.basereachable = ND_IFINFO(ifp)->basereachable;
1657 ND.reachable = ND_IFINFO(ifp)->reachable;
1658 ND.retrans = ND_IFINFO(ifp)->retrans;
1659 ND.flags = ND_IFINFO(ifp)->flags;
1660 ND.recalctm = ND_IFINFO(ifp)->recalctm;
1661 ND.chlim = ND_IFINFO(ifp)->chlim;
1662 break;
1663 case SIOCGIFINFO_IN6:
1664 ND = *ND_IFINFO(ifp);
1665 break;
1666 case SIOCSIFINFO_IN6:
1667 /*
1668 * used to change host variables from userland.
1669 * intended for a use on router to reflect RA configurations.
1670 */
1671 /* 0 means 'unspecified' */
1672 if (ND.linkmtu != 0) {
1673 if (ND.linkmtu < IPV6_MMTU ||
1674 ND.linkmtu > IN6_LINKMTU(ifp)) {
1675 error = EINVAL;
1676 break;
1677 }
1678 ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
1679 }
1680
1681 if (ND.basereachable != 0) {
1682 int obasereachable = ND_IFINFO(ifp)->basereachable;
1683
1684 ND_IFINFO(ifp)->basereachable = ND.basereachable;
1685 if (ND.basereachable != obasereachable)
1686 ND_IFINFO(ifp)->reachable =
1687 ND_COMPUTE_RTIME(ND.basereachable);
1688 }
1689 if (ND.retrans != 0)
1690 ND_IFINFO(ifp)->retrans = ND.retrans;
1691 if (ND.chlim != 0)
1692 ND_IFINFO(ifp)->chlim = ND.chlim;
1693 /* FALLTHROUGH */
1694 case SIOCSIFINFO_FLAGS:
1695 {
1696 struct ifaddr *ifa;
1697 struct in6_ifaddr *ia;
1698
1699 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1700 !(ND.flags & ND6_IFF_IFDISABLED)) {
1701 /* ifdisabled 1->0 transision */
1702
1703 /*
1704 * If the interface is marked as ND6_IFF_IFDISABLED and
1705 * has an link-local address with IN6_IFF_DUPLICATED,
1706 * do not clear ND6_IFF_IFDISABLED.
1707 * See RFC 4862, Section 5.4.5.
1708 */
1709 NET_EPOCH_ENTER(et);
1710 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1711 if (ifa->ifa_addr->sa_family != AF_INET6)
1712 continue;
1713 ia = (struct in6_ifaddr *)ifa;
1714 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1715 IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1716 break;
1717 }
1718 NET_EPOCH_EXIT(et);
1719
1720 if (ifa != NULL) {
1721 /* LLA is duplicated. */
1722 ND.flags |= ND6_IFF_IFDISABLED;
1723 log(LOG_ERR, "Cannot enable an interface"
1724 " with a link-local address marked"
1725 " duplicate.\n");
1726 } else {
1727 ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
1728 if (ifp->if_flags & IFF_UP)
1729 in6_if_up(ifp);
1730 }
1731 } else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1732 (ND.flags & ND6_IFF_IFDISABLED)) {
1733 /* ifdisabled 0->1 transision */
1734 /* Mark all IPv6 address as tentative. */
1735
1736 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1737 if (V_ip6_dad_count > 0 &&
1738 (ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
1739 NET_EPOCH_ENTER(et);
1740 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1741 ifa_link) {
1742 if (ifa->ifa_addr->sa_family !=
1743 AF_INET6)
1744 continue;
1745 ia = (struct in6_ifaddr *)ifa;
1746 ia->ia6_flags |= IN6_IFF_TENTATIVE;
1747 }
1748 NET_EPOCH_EXIT(et);
1749 }
1750 }
1751
1752 if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1753 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
1754 /* auto_linklocal 0->1 transision */
1755
1756 /* If no link-local address on ifp, configure */
1757 ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
1758 in6_ifattach(ifp, NULL);
1759 } else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1760 ifp->if_flags & IFF_UP) {
1761 /*
1762 * When the IF already has
1763 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1764 * address is assigned, and IFF_UP, try to
1765 * assign one.
1766 */
1767 NET_EPOCH_ENTER(et);
1768 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1769 ifa_link) {
1770 if (ifa->ifa_addr->sa_family !=
1771 AF_INET6)
1772 continue;
1773 ia = (struct in6_ifaddr *)ifa;
1774 if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1775 break;
1776 }
1777 NET_EPOCH_EXIT(et);
1778 if (ifa != NULL)
1779 /* No LLA is configured. */
1780 in6_ifattach(ifp, NULL);
1781 }
1782 }
1783 ND_IFINFO(ifp)->flags = ND.flags;
1784 break;
1785 }
1786 #undef ND
1787 case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */
1788 /* sync kernel routing table with the default router list */
1789 defrouter_reset();
1790 defrouter_select_fib(RT_ALL_FIBS);
1791 break;
1792 case SIOCSPFXFLUSH_IN6:
1793 {
1794 /* flush all the prefix advertised by routers */
1795 struct in6_ifaddr *ia, *ia_next;
1796 struct nd_prefix *pr, *next;
1797 struct nd_prhead prl;
1798
1799 LIST_INIT(&prl);
1800
1801 ND6_WLOCK();
1802 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
1803 if (pr->ndpr_raf_ra_derived)
1804 nd6_prefix_unlink(pr, &prl);
1805 }
1806 ND6_WUNLOCK();
1807
1808 while ((pr = LIST_FIRST(&prl)) != NULL) {
1809 LIST_REMOVE(pr, ndpr_entry);
1810 /* XXXRW: in6_ifaddrhead locking. */
1811 CK_STAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
1812 ia_next) {
1813 if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1814 continue;
1815
1816 if (ia->ia6_ndpr == pr)
1817 in6_purgeaddr(&ia->ia_ifa);
1818 }
1819 nd6_prefix_del(pr);
1820 }
1821 break;
1822 }
1823 case SIOCSRTRFLUSH_IN6:
1824 {
1825 /* flush all the default routers */
1826
1827 defrouter_reset();
1828 nd6_defrouter_flush_all();
1829 defrouter_select_fib(RT_ALL_FIBS);
1830 break;
1831 }
1832 case SIOCGNBRINFO_IN6:
1833 {
1834 struct llentry *ln;
1835 struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1836
1837 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1838 return (error);
1839
1840 NET_EPOCH_ENTER(et);
1841 ln = nd6_lookup(&nb_addr, LLE_SF(AF_INET6, 0), ifp);
1842 NET_EPOCH_EXIT(et);
1843
1844 if (ln == NULL) {
1845 error = EINVAL;
1846 break;
1847 }
1848 nbi->state = ln->ln_state;
1849 nbi->asked = ln->la_asked;
1850 nbi->isrouter = ln->ln_router;
1851 if (ln->la_expire == 0)
1852 nbi->expire = 0;
1853 else
1854 nbi->expire = ln->la_expire + ln->lle_remtime / hz +
1855 (time_second - time_uptime);
1856 LLE_RUNLOCK(ln);
1857 break;
1858 }
1859 case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1860 ndif->ifindex = V_nd6_defifindex;
1861 break;
1862 case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1863 return (nd6_setdefaultiface(ndif->ifindex));
1864 }
1865 return (error);
1866 }
1867
1868 /*
1869 * Calculates new isRouter value based on provided parameters and
1870 * returns it.
1871 */
1872 static int
nd6_is_router(int type,int code,int is_new,int old_addr,int new_addr,int ln_router)1873 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
1874 int ln_router)
1875 {
1876
1877 /*
1878 * ICMP6 type dependent behavior.
1879 *
1880 * NS: clear IsRouter if new entry
1881 * RS: clear IsRouter
1882 * RA: set IsRouter if there's lladdr
1883 * redir: clear IsRouter if new entry
1884 *
1885 * RA case, (1):
1886 * The spec says that we must set IsRouter in the following cases:
1887 * - If lladdr exist, set IsRouter. This means (1-5).
1888 * - If it is old entry (!newentry), set IsRouter. This means (7).
1889 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1890 * A quetion arises for (1) case. (1) case has no lladdr in the
1891 * neighbor cache, this is similar to (6).
1892 * This case is rare but we figured that we MUST NOT set IsRouter.
1893 *
1894 * is_new old_addr new_addr NS RS RA redir
1895 * D R
1896 * 0 n n (1) c ? s
1897 * 0 y n (2) c s s
1898 * 0 n y (3) c s s
1899 * 0 y y (4) c s s
1900 * 0 y y (5) c s s
1901 * 1 -- n (6) c c c s
1902 * 1 -- y (7) c c s c s
1903 *
1904 * (c=clear s=set)
1905 */
1906 switch (type & 0xff) {
1907 case ND_NEIGHBOR_SOLICIT:
1908 /*
1909 * New entry must have is_router flag cleared.
1910 */
1911 if (is_new) /* (6-7) */
1912 ln_router = 0;
1913 break;
1914 case ND_REDIRECT:
1915 /*
1916 * If the icmp is a redirect to a better router, always set the
1917 * is_router flag. Otherwise, if the entry is newly created,
1918 * clear the flag. [RFC 2461, sec 8.3]
1919 */
1920 if (code == ND_REDIRECT_ROUTER)
1921 ln_router = 1;
1922 else {
1923 if (is_new) /* (6-7) */
1924 ln_router = 0;
1925 }
1926 break;
1927 case ND_ROUTER_SOLICIT:
1928 /*
1929 * is_router flag must always be cleared.
1930 */
1931 ln_router = 0;
1932 break;
1933 case ND_ROUTER_ADVERT:
1934 /*
1935 * Mark an entry with lladdr as a router.
1936 */
1937 if ((!is_new && (old_addr || new_addr)) || /* (2-5) */
1938 (is_new && new_addr)) { /* (7) */
1939 ln_router = 1;
1940 }
1941 break;
1942 }
1943
1944 return (ln_router);
1945 }
1946
1947 /*
1948 * Create neighbor cache entry and cache link-layer address,
1949 * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1950 *
1951 * type - ICMP6 type
1952 * code - type dependent information
1953 *
1954 */
1955 void
nd6_cache_lladdr(struct ifnet * ifp,struct in6_addr * from,char * lladdr,int lladdrlen,int type,int code)1956 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1957 int lladdrlen, int type, int code)
1958 {
1959 struct llentry *ln = NULL, *ln_tmp;
1960 int is_newentry;
1961 int do_update;
1962 int olladdr;
1963 int llchange;
1964 int flags;
1965 uint16_t router = 0;
1966 struct mbuf *chain = NULL;
1967 u_char linkhdr[LLE_MAX_LINKHDR];
1968 size_t linkhdrsize;
1969 int lladdr_off;
1970
1971 NET_EPOCH_ASSERT();
1972 IF_AFDATA_UNLOCK_ASSERT(ifp);
1973
1974 KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
1975 KASSERT(from != NULL, ("%s: from == NULL", __func__));
1976
1977 /* nothing must be updated for unspecified address */
1978 if (IN6_IS_ADDR_UNSPECIFIED(from))
1979 return;
1980
1981 /*
1982 * Validation about ifp->if_addrlen and lladdrlen must be done in
1983 * the caller.
1984 *
1985 * XXX If the link does not have link-layer adderss, what should
1986 * we do? (ifp->if_addrlen == 0)
1987 * Spec says nothing in sections for RA, RS and NA. There's small
1988 * description on it in NS section (RFC 2461 7.2.3).
1989 */
1990 flags = lladdr ? LLE_EXCLUSIVE : 0;
1991 ln = nd6_lookup(from, LLE_SF(AF_INET6, flags), ifp);
1992 is_newentry = 0;
1993 if (ln == NULL) {
1994 flags |= LLE_EXCLUSIVE;
1995 ln = nd6_alloc(from, 0, ifp);
1996 if (ln == NULL)
1997 return;
1998
1999 /*
2000 * Since we already know all the data for the new entry,
2001 * fill it before insertion.
2002 */
2003 if (lladdr != NULL) {
2004 linkhdrsize = sizeof(linkhdr);
2005 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
2006 linkhdr, &linkhdrsize, &lladdr_off) != 0) {
2007 lltable_free_entry(LLTABLE6(ifp), ln);
2008 return;
2009 }
2010 lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
2011 lladdr_off);
2012 }
2013
2014 IF_AFDATA_WLOCK(ifp);
2015 LLE_WLOCK(ln);
2016 /* Prefer any existing lle over newly-created one */
2017 ln_tmp = nd6_lookup(from, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
2018 if (ln_tmp == NULL)
2019 lltable_link_entry(LLTABLE6(ifp), ln);
2020 IF_AFDATA_WUNLOCK(ifp);
2021 if (ln_tmp == NULL) {
2022 /* No existing lle, mark as new entry (6,7) */
2023 is_newentry = 1;
2024 if (lladdr != NULL) { /* (7) */
2025 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2026 EVENTHANDLER_INVOKE(lle_event, ln,
2027 LLENTRY_RESOLVED);
2028 }
2029 } else {
2030 lltable_free_entry(LLTABLE6(ifp), ln);
2031 ln = ln_tmp;
2032 ln_tmp = NULL;
2033 }
2034 }
2035 /* do nothing if static ndp is set */
2036 if ((ln->la_flags & LLE_STATIC)) {
2037 if (flags & LLE_EXCLUSIVE)
2038 LLE_WUNLOCK(ln);
2039 else
2040 LLE_RUNLOCK(ln);
2041 return;
2042 }
2043
2044 olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
2045 if (olladdr && lladdr) {
2046 llchange = bcmp(lladdr, ln->ll_addr,
2047 ifp->if_addrlen);
2048 } else if (!olladdr && lladdr)
2049 llchange = 1;
2050 else
2051 llchange = 0;
2052
2053 /*
2054 * newentry olladdr lladdr llchange (*=record)
2055 * 0 n n -- (1)
2056 * 0 y n -- (2)
2057 * 0 n y y (3) * STALE
2058 * 0 y y n (4) *
2059 * 0 y y y (5) * STALE
2060 * 1 -- n -- (6) NOSTATE(= PASSIVE)
2061 * 1 -- y -- (7) * STALE
2062 */
2063
2064 do_update = 0;
2065 if (is_newentry == 0 && llchange != 0) {
2066 do_update = 1; /* (3,5) */
2067
2068 /*
2069 * Record source link-layer address
2070 * XXX is it dependent to ifp->if_type?
2071 */
2072 if (!nd6_try_set_entry_addr(ifp, ln, lladdr)) {
2073 /* Entry was deleted */
2074 LLE_WUNLOCK(ln);
2075 return;
2076 }
2077
2078 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2079
2080 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2081
2082 if (ln->la_hold != NULL)
2083 chain = nd6_grab_holdchain(ln);
2084 }
2085
2086 /* Calculates new router status */
2087 router = nd6_is_router(type, code, is_newentry, olladdr,
2088 lladdr != NULL ? 1 : 0, ln->ln_router);
2089
2090 ln->ln_router = router;
2091 /* Mark non-router redirects with special flag */
2092 if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
2093 ln->la_flags |= LLE_REDIRECT;
2094
2095 if (flags & LLE_EXCLUSIVE)
2096 LLE_WUNLOCK(ln);
2097 else
2098 LLE_RUNLOCK(ln);
2099
2100 if (chain != NULL)
2101 nd6_flush_holdchain(ifp, ln, chain);
2102 if (do_update)
2103 nd6_flush_children_holdchain(ifp, ln);
2104
2105 /*
2106 * When the link-layer address of a router changes, select the
2107 * best router again. In particular, when the neighbor entry is newly
2108 * created, it might affect the selection policy.
2109 * Question: can we restrict the first condition to the "is_newentry"
2110 * case?
2111 * XXX: when we hear an RA from a new router with the link-layer
2112 * address option, defrouter_select_fib() is called twice, since
2113 * defrtrlist_update called the function as well. However, I believe
2114 * we can compromise the overhead, since it only happens the first
2115 * time.
2116 * XXX: although defrouter_select_fib() should not have a bad effect
2117 * for those are not autoconfigured hosts, we explicitly avoid such
2118 * cases for safety.
2119 */
2120 if ((do_update || is_newentry) && router &&
2121 ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
2122 /*
2123 * guaranteed recursion
2124 */
2125 defrouter_select_fib(ifp->if_fib);
2126 }
2127 }
2128
2129 static void
nd6_slowtimo(void * arg)2130 nd6_slowtimo(void *arg)
2131 {
2132 struct epoch_tracker et;
2133 CURVNET_SET((struct vnet *) arg);
2134 struct nd_ifinfo *nd6if;
2135 struct ifnet *ifp;
2136
2137 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
2138 nd6_slowtimo, curvnet);
2139 NET_EPOCH_ENTER(et);
2140 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2141 if (ifp->if_afdata[AF_INET6] == NULL)
2142 continue;
2143 nd6if = ND_IFINFO(ifp);
2144 if (nd6if->basereachable && /* already initialized */
2145 (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
2146 /*
2147 * Since reachable time rarely changes by router
2148 * advertisements, we SHOULD insure that a new random
2149 * value gets recomputed at least once every few hours.
2150 * (RFC 2461, 6.3.4)
2151 */
2152 nd6if->recalctm = V_nd6_recalc_reachtm_interval;
2153 nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
2154 }
2155 }
2156 NET_EPOCH_EXIT(et);
2157 CURVNET_RESTORE();
2158 }
2159
2160 struct mbuf *
nd6_grab_holdchain(struct llentry * ln)2161 nd6_grab_holdchain(struct llentry *ln)
2162 {
2163 struct mbuf *chain;
2164
2165 LLE_WLOCK_ASSERT(ln);
2166
2167 chain = ln->la_hold;
2168 ln->la_hold = NULL;
2169 ln->la_numheld = 0;
2170
2171 if (ln->ln_state == ND6_LLINFO_STALE) {
2172 /*
2173 * The first time we send a packet to a
2174 * neighbor whose entry is STALE, we have
2175 * to change the state to DELAY and a sets
2176 * a timer to expire in DELAY_FIRST_PROBE_TIME
2177 * seconds to ensure do neighbor unreachability
2178 * detection on expiration.
2179 * (RFC 2461 7.3.3)
2180 */
2181 nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
2182 }
2183
2184 return (chain);
2185 }
2186
2187 int
nd6_output_ifp(struct ifnet * ifp,struct ifnet * origifp,struct mbuf * m,struct sockaddr_in6 * dst,struct route * ro)2188 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
2189 struct sockaddr_in6 *dst, struct route *ro)
2190 {
2191 int error;
2192 int ip6len;
2193 struct ip6_hdr *ip6;
2194 struct m_tag *mtag;
2195
2196 #ifdef MAC
2197 mac_netinet6_nd6_send(ifp, m);
2198 #endif
2199
2200 /*
2201 * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
2202 * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
2203 * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
2204 * to be diverted to user space. When re-injected into the kernel,
2205 * send_output() will directly dispatch them to the outgoing interface.
2206 */
2207 if (send_sendso_input_hook != NULL) {
2208 mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
2209 if (mtag != NULL) {
2210 ip6 = mtod(m, struct ip6_hdr *);
2211 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
2212 /* Use the SEND socket */
2213 error = send_sendso_input_hook(m, ifp, SND_OUT,
2214 ip6len);
2215 /* -1 == no app on SEND socket */
2216 if (error == 0 || error != -1)
2217 return (error);
2218 }
2219 }
2220
2221 m_clrprotoflags(m); /* Avoid confusing lower layers. */
2222 IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
2223 mtod(m, struct ip6_hdr *));
2224
2225 if ((ifp->if_flags & IFF_LOOPBACK) == 0)
2226 origifp = ifp;
2227
2228 error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
2229 return (error);
2230 }
2231
2232 /*
2233 * Lookup link headerfor @sa_dst address. Stores found
2234 * data in @desten buffer. Copy of lle ln_flags can be also
2235 * saved in @pflags if @pflags is non-NULL.
2236 *
2237 * If destination LLE does not exists or lle state modification
2238 * is required, call "slow" version.
2239 *
2240 * Return values:
2241 * - 0 on success (address copied to buffer).
2242 * - EWOULDBLOCK (no local error, but address is still unresolved)
2243 * - other errors (alloc failure, etc)
2244 */
2245 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)2246 nd6_resolve(struct ifnet *ifp, int gw_flags, struct mbuf *m,
2247 const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
2248 struct llentry **plle)
2249 {
2250 struct llentry *ln = NULL;
2251 const struct sockaddr_in6 *dst6;
2252
2253 NET_EPOCH_ASSERT();
2254
2255 if (pflags != NULL)
2256 *pflags = 0;
2257
2258 dst6 = (const struct sockaddr_in6 *)sa_dst;
2259
2260 /* discard the packet if IPv6 operation is disabled on the interface */
2261 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
2262 m_freem(m);
2263 return (ENETDOWN); /* better error? */
2264 }
2265
2266 if (m != NULL && m->m_flags & M_MCAST) {
2267 switch (ifp->if_type) {
2268 case IFT_ETHER:
2269 case IFT_L2VLAN:
2270 case IFT_BRIDGE:
2271 ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
2272 desten);
2273 return (0);
2274 default:
2275 m_freem(m);
2276 return (EAFNOSUPPORT);
2277 }
2278 }
2279
2280 int family = gw_flags >> 16;
2281 int lookup_flags = plle ? LLE_EXCLUSIVE : LLE_UNLOCKED;
2282 ln = nd6_lookup(&dst6->sin6_addr, LLE_SF(family, lookup_flags), ifp);
2283 if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
2284 /* Entry found, let's copy lle info */
2285 bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
2286 if (pflags != NULL)
2287 *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
2288 llentry_provide_feedback(ln);
2289 if (plle) {
2290 LLE_ADDREF(ln);
2291 *plle = ln;
2292 LLE_WUNLOCK(ln);
2293 }
2294 return (0);
2295 } else if (plle && ln)
2296 LLE_WUNLOCK(ln);
2297
2298 return (nd6_resolve_slow(ifp, family, 0, m, dst6, desten, pflags, plle));
2299 }
2300
2301 /*
2302 * Finds or creates a new llentry for @addr and @family.
2303 * Returns wlocked llentry or NULL.
2304 *
2305 *
2306 * Child LLEs.
2307 *
2308 * Do not have their own state machine (gets marked as static)
2309 * settimer bails out for child LLEs just in case.
2310 *
2311 * Locking order: parent lle gets locked first, chen goes the child.
2312 */
2313 static __noinline struct llentry *
nd6_get_llentry(struct ifnet * ifp,const struct in6_addr * addr,int family)2314 nd6_get_llentry(struct ifnet *ifp, const struct in6_addr *addr, int family)
2315 {
2316 struct llentry *child_lle = NULL;
2317 struct llentry *lle, *lle_tmp;
2318
2319 lle = nd6_alloc(addr, 0, ifp);
2320 if (lle != NULL && family != AF_INET6) {
2321 child_lle = nd6_alloc(addr, 0, ifp);
2322 if (child_lle == NULL) {
2323 lltable_free_entry(LLTABLE6(ifp), lle);
2324 return (NULL);
2325 }
2326 child_lle->r_family = family;
2327 child_lle->la_flags |= LLE_CHILD | LLE_STATIC;
2328 child_lle->ln_state = ND6_LLINFO_INCOMPLETE;
2329 }
2330
2331 if (lle == NULL) {
2332 char ip6buf[INET6_ADDRSTRLEN];
2333 log(LOG_DEBUG,
2334 "nd6_get_llentry: can't allocate llinfo for %s "
2335 "(ln=%p)\n",
2336 ip6_sprintf(ip6buf, addr), lle);
2337 return (NULL);
2338 }
2339
2340 IF_AFDATA_WLOCK(ifp);
2341 LLE_WLOCK(lle);
2342 /* Prefer any existing entry over newly-created one */
2343 lle_tmp = nd6_lookup(addr, LLE_SF(AF_INET6, LLE_EXCLUSIVE), ifp);
2344 if (lle_tmp == NULL)
2345 lltable_link_entry(LLTABLE6(ifp), lle);
2346 else {
2347 lltable_free_entry(LLTABLE6(ifp), lle);
2348 lle = lle_tmp;
2349 }
2350 if (child_lle != NULL) {
2351 /* Check if child lle for the same family exists */
2352 lle_tmp = llentry_lookup_family(lle, child_lle->r_family);
2353 LLE_WLOCK(child_lle);
2354 if (lle_tmp == NULL) {
2355 /* Attach */
2356 lltable_link_child_entry(lle, child_lle);
2357 } else {
2358 /* child lle already exists, free newly-created one */
2359 lltable_free_entry(LLTABLE6(ifp), child_lle);
2360 child_lle = lle_tmp;
2361 }
2362 LLE_WUNLOCK(lle);
2363 lle = child_lle;
2364 }
2365 IF_AFDATA_WUNLOCK(ifp);
2366 return (lle);
2367 }
2368
2369 /*
2370 * Do L2 address resolution for @sa_dst address. Stores found
2371 * address in @desten buffer. Copy of lle ln_flags can be also
2372 * saved in @pflags if @pflags is non-NULL.
2373 *
2374 * Heavy version.
2375 * Function assume that destination LLE does not exist,
2376 * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
2377 *
2378 * Set noinline to be dtrace-friendly
2379 */
2380 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)2381 nd6_resolve_slow(struct ifnet *ifp, int family, int flags, struct mbuf *m,
2382 const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
2383 struct llentry **plle)
2384 {
2385 struct llentry *lle = NULL;
2386 struct in6_addr *psrc, src;
2387 int send_ns, ll_len;
2388 char *lladdr;
2389
2390 NET_EPOCH_ASSERT();
2391
2392 /*
2393 * Address resolution or Neighbor Unreachability Detection
2394 * for the next hop.
2395 * At this point, the destination of the packet must be a unicast
2396 * or an anycast address(i.e. not a multicast).
2397 */
2398 lle = nd6_lookup(&dst->sin6_addr, LLE_SF(family, LLE_EXCLUSIVE), ifp);
2399 if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp)) {
2400 /*
2401 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2402 * the condition below is not very efficient. But we believe
2403 * it is tolerable, because this should be a rare case.
2404 */
2405 lle = nd6_get_llentry(ifp, &dst->sin6_addr, family);
2406 }
2407
2408 if (lle == NULL) {
2409 m_freem(m);
2410 return (ENOBUFS);
2411 }
2412
2413 LLE_WLOCK_ASSERT(lle);
2414
2415 /*
2416 * The first time we send a packet to a neighbor whose entry is
2417 * STALE, we have to change the state to DELAY and a sets a timer to
2418 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2419 * neighbor unreachability detection on expiration.
2420 * (RFC 2461 7.3.3)
2421 */
2422 if ((!(lle->la_flags & LLE_CHILD)) && (lle->ln_state == ND6_LLINFO_STALE))
2423 nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
2424
2425 /*
2426 * If the neighbor cache entry has a state other than INCOMPLETE
2427 * (i.e. its link-layer address is already resolved), just
2428 * send the packet.
2429 */
2430 if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
2431 if (flags & LLE_ADDRONLY) {
2432 lladdr = lle->ll_addr;
2433 ll_len = ifp->if_addrlen;
2434 } else {
2435 lladdr = lle->r_linkdata;
2436 ll_len = lle->r_hdrlen;
2437 }
2438 bcopy(lladdr, desten, ll_len);
2439 if (pflags != NULL)
2440 *pflags = lle->la_flags;
2441 if (plle) {
2442 LLE_ADDREF(lle);
2443 *plle = lle;
2444 }
2445 LLE_WUNLOCK(lle);
2446 return (0);
2447 }
2448
2449 /*
2450 * There is a neighbor cache entry, but no ethernet address
2451 * response yet. Append this latest packet to the end of the
2452 * packet queue in the mbuf. When it exceeds nd6_maxqueuelen,
2453 * the oldest packet in the queue will be removed.
2454 */
2455 if (m != NULL) {
2456 size_t dropped;
2457
2458 dropped = lltable_append_entry_queue(lle, m, V_nd6_maxqueuelen);
2459 ICMP6STAT_ADD(icp6s_dropped, dropped);
2460 }
2461
2462 /*
2463 * If there has been no NS for the neighbor after entering the
2464 * INCOMPLETE state, send the first solicitation.
2465 * Note that for newly-created lle la_asked will be 0,
2466 * so we will transition from ND6_LLINFO_NOSTATE to
2467 * ND6_LLINFO_INCOMPLETE state here.
2468 */
2469 psrc = NULL;
2470 send_ns = 0;
2471
2472 /* If we have child lle, switch to the parent to send NS */
2473 if (lle->la_flags & LLE_CHILD) {
2474 struct llentry *lle_parent = lle->lle_parent;
2475 LLE_WUNLOCK(lle);
2476 lle = lle_parent;
2477 LLE_WLOCK(lle);
2478 }
2479 if (lle->la_asked == 0) {
2480 lle->la_asked++;
2481 send_ns = 1;
2482 psrc = nd6_llinfo_get_holdsrc(lle, &src);
2483
2484 nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
2485 }
2486 LLE_WUNLOCK(lle);
2487 if (send_ns != 0)
2488 nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
2489
2490 return (EWOULDBLOCK);
2491 }
2492
2493 /*
2494 * Do L2 address resolution for @sa_dst address. Stores found
2495 * address in @desten buffer. Copy of lle ln_flags can be also
2496 * saved in @pflags if @pflags is non-NULL.
2497 *
2498 * Return values:
2499 * - 0 on success (address copied to buffer).
2500 * - EWOULDBLOCK (no local error, but address is still unresolved)
2501 * - other errors (alloc failure, etc)
2502 */
2503 int
nd6_resolve_addr(struct ifnet * ifp,int flags,const struct sockaddr * dst,char * desten,uint32_t * pflags)2504 nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
2505 char *desten, uint32_t *pflags)
2506 {
2507 int error;
2508
2509 flags |= LLE_ADDRONLY;
2510 error = nd6_resolve_slow(ifp, AF_INET6, flags, NULL,
2511 (const struct sockaddr_in6 *)dst, desten, pflags, NULL);
2512 return (error);
2513 }
2514
2515 int
nd6_flush_holdchain(struct ifnet * ifp,struct llentry * lle,struct mbuf * chain)2516 nd6_flush_holdchain(struct ifnet *ifp, struct llentry *lle, struct mbuf *chain)
2517 {
2518 struct mbuf *m, *m_head;
2519 struct sockaddr_in6 dst6;
2520 int error = 0;
2521
2522 NET_EPOCH_ASSERT();
2523
2524 struct route_in6 ro = {
2525 .ro_prepend = lle->r_linkdata,
2526 .ro_plen = lle->r_hdrlen,
2527 };
2528
2529 lltable_fill_sa_entry(lle, (struct sockaddr *)&dst6);
2530 m_head = chain;
2531
2532 while (m_head) {
2533 m = m_head;
2534 m_head = m_head->m_nextpkt;
2535 m->m_nextpkt = NULL;
2536 error = nd6_output_ifp(ifp, ifp, m, &dst6, (struct route *)&ro);
2537 }
2538
2539 /*
2540 * XXX
2541 * note that intermediate errors are blindly ignored
2542 */
2543 return (error);
2544 }
2545
2546 __noinline void
nd6_flush_children_holdchain(struct ifnet * ifp,struct llentry * lle)2547 nd6_flush_children_holdchain(struct ifnet *ifp, struct llentry *lle)
2548 {
2549 struct llentry *child_lle;
2550 struct mbuf *chain;
2551
2552 NET_EPOCH_ASSERT();
2553
2554 CK_SLIST_FOREACH(child_lle, &lle->lle_children, lle_child_next) {
2555 LLE_WLOCK(child_lle);
2556 chain = nd6_grab_holdchain(child_lle);
2557 LLE_WUNLOCK(child_lle);
2558 nd6_flush_holdchain(ifp, child_lle, chain);
2559 }
2560 }
2561
2562 static int
nd6_need_cache(struct ifnet * ifp)2563 nd6_need_cache(struct ifnet *ifp)
2564 {
2565 /*
2566 * XXX: we currently do not make neighbor cache on any interface
2567 * other than Ethernet and GIF.
2568 *
2569 * RFC2893 says:
2570 * - unidirectional tunnels needs no ND
2571 */
2572 switch (ifp->if_type) {
2573 case IFT_ETHER:
2574 case IFT_IEEE1394:
2575 case IFT_L2VLAN:
2576 case IFT_INFINIBAND:
2577 case IFT_BRIDGE:
2578 case IFT_PROPVIRTUAL:
2579 return (1);
2580 default:
2581 return (0);
2582 }
2583 }
2584
2585 /*
2586 * Add pernament ND6 link-layer record for given
2587 * interface address.
2588 *
2589 * Very similar to IPv4 arp_ifinit(), but:
2590 * 1) IPv6 DAD is performed in different place
2591 * 2) It is called by IPv6 protocol stack in contrast to
2592 * arp_ifinit() which is typically called in SIOCSIFADDR
2593 * driver ioctl handler.
2594 *
2595 */
2596 int
nd6_add_ifa_lle(struct in6_ifaddr * ia)2597 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2598 {
2599 struct ifnet *ifp;
2600 struct llentry *ln, *ln_tmp;
2601 struct sockaddr *dst;
2602
2603 ifp = ia->ia_ifa.ifa_ifp;
2604 if (nd6_need_cache(ifp) == 0)
2605 return (0);
2606
2607 dst = (struct sockaddr *)&ia->ia_addr;
2608 ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
2609 if (ln == NULL)
2610 return (ENOBUFS);
2611
2612 IF_AFDATA_WLOCK(ifp);
2613 LLE_WLOCK(ln);
2614 /* Unlink any entry if exists */
2615 ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_SF(AF_INET6, LLE_EXCLUSIVE), dst);
2616 if (ln_tmp != NULL)
2617 lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
2618 lltable_link_entry(LLTABLE6(ifp), ln);
2619 IF_AFDATA_WUNLOCK(ifp);
2620
2621 if (ln_tmp != NULL)
2622 EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
2623 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2624
2625 LLE_WUNLOCK(ln);
2626 if (ln_tmp != NULL)
2627 llentry_free(ln_tmp);
2628
2629 return (0);
2630 }
2631
2632 /*
2633 * Removes either all lle entries for given @ia, or lle
2634 * corresponding to @ia address.
2635 */
2636 void
nd6_rem_ifa_lle(struct in6_ifaddr * ia,int all)2637 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
2638 {
2639 struct sockaddr_in6 mask, addr;
2640 struct sockaddr *saddr, *smask;
2641 struct ifnet *ifp;
2642
2643 ifp = ia->ia_ifa.ifa_ifp;
2644 memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2645 memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2646 saddr = (struct sockaddr *)&addr;
2647 smask = (struct sockaddr *)&mask;
2648
2649 if (all != 0)
2650 lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
2651 else
2652 lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
2653 }
2654
2655 static int
nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)2656 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2657 {
2658 struct in6_prefix p;
2659 struct sockaddr_in6 s6;
2660 struct nd_prefix *pr;
2661 struct nd_pfxrouter *pfr;
2662 time_t maxexpire;
2663 int error;
2664 char ip6buf[INET6_ADDRSTRLEN];
2665
2666 if (req->newptr)
2667 return (EPERM);
2668
2669 error = sysctl_wire_old_buffer(req, 0);
2670 if (error != 0)
2671 return (error);
2672
2673 bzero(&p, sizeof(p));
2674 p.origin = PR_ORIG_RA;
2675 bzero(&s6, sizeof(s6));
2676 s6.sin6_family = AF_INET6;
2677 s6.sin6_len = sizeof(s6);
2678
2679 ND6_RLOCK();
2680 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
2681 if (!pr->ndpr_raf_ra_derived)
2682 continue;
2683 p.prefix = pr->ndpr_prefix;
2684 if (sa6_recoverscope(&p.prefix)) {
2685 log(LOG_ERR, "scope error in prefix list (%s)\n",
2686 ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
2687 /* XXX: press on... */
2688 }
2689 p.raflags = pr->ndpr_raf;
2690 p.prefixlen = pr->ndpr_plen;
2691 p.vltime = pr->ndpr_vltime;
2692 p.pltime = pr->ndpr_pltime;
2693 p.if_index = pr->ndpr_ifp->if_index;
2694 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2695 p.expire = 0;
2696 else {
2697 /* XXX: we assume time_t is signed. */
2698 maxexpire = (-1) &
2699 ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
2700 if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
2701 p.expire = pr->ndpr_lastupdate +
2702 pr->ndpr_vltime +
2703 (time_second - time_uptime);
2704 else
2705 p.expire = maxexpire;
2706 }
2707 p.refcnt = pr->ndpr_addrcnt;
2708 p.flags = pr->ndpr_stateflags;
2709 p.advrtrs = 0;
2710 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2711 p.advrtrs++;
2712 error = SYSCTL_OUT(req, &p, sizeof(p));
2713 if (error != 0)
2714 break;
2715 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2716 s6.sin6_addr = pfr->router->rtaddr;
2717 if (sa6_recoverscope(&s6))
2718 log(LOG_ERR,
2719 "scope error in prefix list (%s)\n",
2720 ip6_sprintf(ip6buf, &pfr->router->rtaddr));
2721 error = SYSCTL_OUT(req, &s6, sizeof(s6));
2722 if (error != 0)
2723 goto out;
2724 }
2725 }
2726 out:
2727 ND6_RUNLOCK();
2728 return (error);
2729 }
2730 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2731 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
2732 NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
2733 "NDP prefix list");
2734 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
2735 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
2736 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
2737 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
2738