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 __FBSDID("$FreeBSD$");
36
37 #include "opt_inet.h"
38 #include "opt_inet6.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.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_types.h>
63 #include <net/route.h>
64 #include <net/vnet.h>
65
66 #include <netinet/in.h>
67 #include <netinet/in_kdtrace.h>
68 #include <net/if_llatbl.h>
69 #include <netinet/if_ether.h>
70 #include <netinet6/in6_var.h>
71 #include <netinet/ip6.h>
72 #include <netinet6/ip6_var.h>
73 #include <netinet6/scope6_var.h>
74 #include <netinet6/nd6.h>
75 #include <netinet6/in6_ifattach.h>
76 #include <netinet/icmp6.h>
77 #include <netinet6/send.h>
78
79 #include <sys/limits.h>
80
81 #include <security/mac/mac_framework.h>
82
83 #define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
84 #define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
85
86 #define SIN6(s) ((const struct sockaddr_in6 *)(s))
87
88 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
89
90 /* timer values */
91 VNET_DEFINE(int, nd6_prune) = 1; /* walk list every 1 seconds */
92 VNET_DEFINE(int, nd6_delay) = 5; /* delay first probe time 5 second */
93 VNET_DEFINE(int, nd6_umaxtries) = 3; /* maximum unicast query */
94 VNET_DEFINE(int, nd6_mmaxtries) = 3; /* maximum multicast query */
95 VNET_DEFINE(int, nd6_useloopback) = 1; /* use loopback interface for
96 * local traffic */
97 VNET_DEFINE(int, nd6_gctimer) = (60 * 60 * 24); /* 1 day: garbage
98 * collection timer */
99
100 /* preventing too many loops in ND option parsing */
101 VNET_DEFINE_STATIC(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
102
103 VNET_DEFINE(int, nd6_maxnudhint) = 0; /* max # of subsequent upper
104 * layer hints */
105 VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 1; /* max pkts cached in unresolved
106 * ND entries */
107 #define V_nd6_maxndopt VNET(nd6_maxndopt)
108 #define V_nd6_maxqueuelen VNET(nd6_maxqueuelen)
109
110 #ifdef ND6_DEBUG
111 VNET_DEFINE(int, nd6_debug) = 1;
112 #else
113 VNET_DEFINE(int, nd6_debug) = 0;
114 #endif
115
116 static eventhandler_tag lle_event_eh, iflladdr_event_eh;
117
118 VNET_DEFINE(struct nd_drhead, nd_defrouter);
119 VNET_DEFINE(struct nd_prhead, nd_prefix);
120 VNET_DEFINE(struct rwlock, nd6_lock);
121 VNET_DEFINE(uint64_t, nd6_list_genid);
122 VNET_DEFINE(struct mtx, nd6_onlink_mtx);
123
124 VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
125 #define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
126
127 int (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
128
129 static int nd6_is_new_addr_neighbor(const struct sockaddr_in6 *,
130 struct ifnet *);
131 static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
132 static void nd6_slowtimo(void *);
133 static int regen_tmpaddr(struct in6_ifaddr *);
134 static void nd6_free(struct llentry **, int);
135 static void nd6_free_redirect(const struct llentry *);
136 static void nd6_llinfo_timer(void *);
137 static void nd6_llinfo_settimer_locked(struct llentry *, long);
138 static void clear_llinfo_pqueue(struct llentry *);
139 static void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
140 static int nd6_resolve_slow(struct ifnet *, int, struct mbuf *,
141 const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
142 static int nd6_need_cache(struct ifnet *);
143
144
145 VNET_DEFINE_STATIC(struct callout, nd6_slowtimo_ch);
146 #define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch)
147
148 VNET_DEFINE(struct callout, nd6_timer_ch);
149 #define V_nd6_timer_ch VNET(nd6_timer_ch)
150
151 static void
nd6_lle_event(void * arg __unused,struct llentry * lle,int evt)152 nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
153 {
154 struct rt_addrinfo rtinfo;
155 struct sockaddr_in6 dst;
156 struct sockaddr_dl gw;
157 struct ifnet *ifp;
158 int type;
159 int fibnum;
160
161 LLE_WLOCK_ASSERT(lle);
162
163 if (lltable_get_af(lle->lle_tbl) != AF_INET6)
164 return;
165
166 switch (evt) {
167 case LLENTRY_RESOLVED:
168 type = RTM_ADD;
169 KASSERT(lle->la_flags & LLE_VALID,
170 ("%s: %p resolved but not valid?", __func__, lle));
171 break;
172 case LLENTRY_EXPIRED:
173 type = RTM_DELETE;
174 break;
175 default:
176 return;
177 }
178
179 ifp = lltable_get_ifp(lle->lle_tbl);
180
181 bzero(&dst, sizeof(dst));
182 bzero(&gw, sizeof(gw));
183 bzero(&rtinfo, sizeof(rtinfo));
184 lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
185 dst.sin6_scope_id = in6_getscopezone(ifp,
186 in6_addrscope(&dst.sin6_addr));
187 gw.sdl_len = sizeof(struct sockaddr_dl);
188 gw.sdl_family = AF_LINK;
189 gw.sdl_alen = ifp->if_addrlen;
190 gw.sdl_index = ifp->if_index;
191 gw.sdl_type = ifp->if_type;
192 if (evt == LLENTRY_RESOLVED)
193 bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
194 rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
195 rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
196 rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
197 fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib;
198 rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
199 type == RTM_ADD ? RTF_UP: 0), 0, fibnum);
200 }
201
202 /*
203 * A handler for interface link layer address change event.
204 */
205 static void
nd6_iflladdr(void * arg __unused,struct ifnet * ifp)206 nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
207 {
208
209 lltable_update_ifaddr(LLTABLE6(ifp));
210 }
211
212 void
nd6_init(void)213 nd6_init(void)
214 {
215
216 mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF);
217 rw_init(&V_nd6_lock, "nd6 list");
218
219 LIST_INIT(&V_nd_prefix);
220 TAILQ_INIT(&V_nd_defrouter);
221
222 /* Start timers. */
223 callout_init(&V_nd6_slowtimo_ch, 0);
224 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
225 nd6_slowtimo, curvnet);
226
227 callout_init(&V_nd6_timer_ch, 0);
228 callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
229
230 nd6_dad_init();
231 if (IS_DEFAULT_VNET(curvnet)) {
232 lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
233 NULL, EVENTHANDLER_PRI_ANY);
234 iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
235 nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
236 }
237 }
238
239 #ifdef VIMAGE
240 void
nd6_destroy()241 nd6_destroy()
242 {
243
244 callout_drain(&V_nd6_slowtimo_ch);
245 callout_drain(&V_nd6_timer_ch);
246 if (IS_DEFAULT_VNET(curvnet)) {
247 EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
248 EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
249 }
250 rw_destroy(&V_nd6_lock);
251 mtx_destroy(&V_nd6_onlink_mtx);
252 }
253 #endif
254
255 struct nd_ifinfo *
nd6_ifattach(struct ifnet * ifp)256 nd6_ifattach(struct ifnet *ifp)
257 {
258 struct nd_ifinfo *nd;
259
260 nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
261 nd->initialized = 1;
262
263 nd->chlim = IPV6_DEFHLIM;
264 nd->basereachable = REACHABLE_TIME;
265 nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
266 nd->retrans = RETRANS_TIMER;
267
268 nd->flags = ND6_IFF_PERFORMNUD;
269
270 /* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
271 * XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
272 * default regardless of the V_ip6_auto_linklocal configuration to
273 * give a reasonable default behavior.
274 */
275 if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
276 (ifp->if_flags & IFF_LOOPBACK))
277 nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
278 /*
279 * A loopback interface does not need to accept RTADV.
280 * XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
281 * default regardless of the V_ip6_accept_rtadv configuration to
282 * prevent the interface from accepting RA messages arrived
283 * on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
284 */
285 if (V_ip6_accept_rtadv &&
286 !(ifp->if_flags & IFF_LOOPBACK) &&
287 (ifp->if_type != IFT_BRIDGE))
288 nd->flags |= ND6_IFF_ACCEPT_RTADV;
289 if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
290 nd->flags |= ND6_IFF_NO_RADR;
291
292 /* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
293 nd6_setmtu0(ifp, nd);
294
295 return nd;
296 }
297
298 void
nd6_ifdetach(struct ifnet * ifp,struct nd_ifinfo * nd)299 nd6_ifdetach(struct ifnet *ifp, struct nd_ifinfo *nd)
300 {
301 struct ifaddr *ifa, *next;
302
303 IF_ADDR_RLOCK(ifp);
304 CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
305 if (ifa->ifa_addr->sa_family != AF_INET6)
306 continue;
307
308 /* stop DAD processing */
309 nd6_dad_stop(ifa);
310 }
311 IF_ADDR_RUNLOCK(ifp);
312
313 free(nd, M_IP6NDP);
314 }
315
316 /*
317 * Reset ND level link MTU. This function is called when the physical MTU
318 * changes, which means we might have to adjust the ND level MTU.
319 */
320 void
nd6_setmtu(struct ifnet * ifp)321 nd6_setmtu(struct ifnet *ifp)
322 {
323 if (ifp->if_afdata[AF_INET6] == NULL)
324 return;
325
326 nd6_setmtu0(ifp, ND_IFINFO(ifp));
327 }
328
329 /* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
330 void
nd6_setmtu0(struct ifnet * ifp,struct nd_ifinfo * ndi)331 nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
332 {
333 u_int32_t omaxmtu;
334
335 omaxmtu = ndi->maxmtu;
336 ndi->maxmtu = ifp->if_mtu;
337
338 /*
339 * Decreasing the interface MTU under IPV6 minimum MTU may cause
340 * undesirable situation. We thus notify the operator of the change
341 * explicitly. The check for omaxmtu is necessary to restrict the
342 * log to the case of changing the MTU, not initializing it.
343 */
344 if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
345 log(LOG_NOTICE, "nd6_setmtu0: "
346 "new link MTU on %s (%lu) is too small for IPv6\n",
347 if_name(ifp), (unsigned long)ndi->maxmtu);
348 }
349
350 if (ndi->maxmtu > V_in6_maxmtu)
351 in6_setmaxmtu(); /* check all interfaces just in case */
352
353 }
354
355 void
nd6_option_init(void * opt,int icmp6len,union nd_opts * ndopts)356 nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
357 {
358
359 bzero(ndopts, sizeof(*ndopts));
360 ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
361 ndopts->nd_opts_last
362 = (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
363
364 if (icmp6len == 0) {
365 ndopts->nd_opts_done = 1;
366 ndopts->nd_opts_search = NULL;
367 }
368 }
369
370 /*
371 * Take one ND option.
372 */
373 struct nd_opt_hdr *
nd6_option(union nd_opts * ndopts)374 nd6_option(union nd_opts *ndopts)
375 {
376 struct nd_opt_hdr *nd_opt;
377 int olen;
378
379 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
380 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
381 __func__));
382 if (ndopts->nd_opts_search == NULL)
383 return NULL;
384 if (ndopts->nd_opts_done)
385 return NULL;
386
387 nd_opt = ndopts->nd_opts_search;
388
389 /* make sure nd_opt_len is inside the buffer */
390 if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
391 bzero(ndopts, sizeof(*ndopts));
392 return NULL;
393 }
394
395 olen = nd_opt->nd_opt_len << 3;
396 if (olen == 0) {
397 /*
398 * Message validation requires that all included
399 * options have a length that is greater than zero.
400 */
401 bzero(ndopts, sizeof(*ndopts));
402 return NULL;
403 }
404
405 ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
406 if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
407 /* option overruns the end of buffer, invalid */
408 bzero(ndopts, sizeof(*ndopts));
409 return NULL;
410 } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
411 /* reached the end of options chain */
412 ndopts->nd_opts_done = 1;
413 ndopts->nd_opts_search = NULL;
414 }
415 return nd_opt;
416 }
417
418 /*
419 * Parse multiple ND options.
420 * This function is much easier to use, for ND routines that do not need
421 * multiple options of the same type.
422 */
423 int
nd6_options(union nd_opts * ndopts)424 nd6_options(union nd_opts *ndopts)
425 {
426 struct nd_opt_hdr *nd_opt;
427 int i = 0;
428
429 KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
430 KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
431 __func__));
432 if (ndopts->nd_opts_search == NULL)
433 return 0;
434
435 while (1) {
436 nd_opt = nd6_option(ndopts);
437 if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
438 /*
439 * Message validation requires that all included
440 * options have a length that is greater than zero.
441 */
442 ICMP6STAT_INC(icp6s_nd_badopt);
443 bzero(ndopts, sizeof(*ndopts));
444 return -1;
445 }
446
447 if (nd_opt == NULL)
448 goto skip1;
449
450 switch (nd_opt->nd_opt_type) {
451 case ND_OPT_SOURCE_LINKADDR:
452 case ND_OPT_TARGET_LINKADDR:
453 case ND_OPT_MTU:
454 case ND_OPT_REDIRECTED_HEADER:
455 case ND_OPT_NONCE:
456 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
457 nd6log((LOG_INFO,
458 "duplicated ND6 option found (type=%d)\n",
459 nd_opt->nd_opt_type));
460 /* XXX bark? */
461 } else {
462 ndopts->nd_opt_array[nd_opt->nd_opt_type]
463 = nd_opt;
464 }
465 break;
466 case ND_OPT_PREFIX_INFORMATION:
467 if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
468 ndopts->nd_opt_array[nd_opt->nd_opt_type]
469 = nd_opt;
470 }
471 ndopts->nd_opts_pi_end =
472 (struct nd_opt_prefix_info *)nd_opt;
473 break;
474 /* What about ND_OPT_ROUTE_INFO? RFC 4191 */
475 case ND_OPT_RDNSS: /* RFC 6106 */
476 case ND_OPT_DNSSL: /* RFC 6106 */
477 /*
478 * Silently ignore options we know and do not care about
479 * in the kernel.
480 */
481 break;
482 default:
483 /*
484 * Unknown options must be silently ignored,
485 * to accommodate future extension to the protocol.
486 */
487 nd6log((LOG_DEBUG,
488 "nd6_options: unsupported option %d - "
489 "option ignored\n", nd_opt->nd_opt_type));
490 }
491
492 skip1:
493 i++;
494 if (i > V_nd6_maxndopt) {
495 ICMP6STAT_INC(icp6s_nd_toomanyopt);
496 nd6log((LOG_INFO, "too many loop in nd opt\n"));
497 break;
498 }
499
500 if (ndopts->nd_opts_done)
501 break;
502 }
503
504 return 0;
505 }
506
507 /*
508 * ND6 timer routine to handle ND6 entries
509 */
510 static void
nd6_llinfo_settimer_locked(struct llentry * ln,long tick)511 nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
512 {
513 int canceled;
514
515 LLE_WLOCK_ASSERT(ln);
516
517 if (tick < 0) {
518 ln->la_expire = 0;
519 ln->ln_ntick = 0;
520 canceled = callout_stop(&ln->lle_timer);
521 } else {
522 ln->la_expire = time_uptime + tick / hz;
523 LLE_ADDREF(ln);
524 if (tick > INT_MAX) {
525 ln->ln_ntick = tick - INT_MAX;
526 canceled = callout_reset(&ln->lle_timer, INT_MAX,
527 nd6_llinfo_timer, ln);
528 } else {
529 ln->ln_ntick = 0;
530 canceled = callout_reset(&ln->lle_timer, tick,
531 nd6_llinfo_timer, ln);
532 }
533 }
534 if (canceled > 0)
535 LLE_REMREF(ln);
536 }
537
538 /*
539 * Gets source address of the first packet in hold queue
540 * and stores it in @src.
541 * Returns pointer to @src (if hold queue is not empty) or NULL.
542 *
543 * Set noinline to be dtrace-friendly
544 */
545 static __noinline struct in6_addr *
nd6_llinfo_get_holdsrc(struct llentry * ln,struct in6_addr * src)546 nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
547 {
548 struct ip6_hdr hdr;
549 struct mbuf *m;
550
551 if (ln->la_hold == NULL)
552 return (NULL);
553
554 /*
555 * assume every packet in la_hold has the same IP header
556 */
557 m = ln->la_hold;
558 if (sizeof(hdr) > m->m_len)
559 return (NULL);
560
561 m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
562 *src = hdr.ip6_src;
563
564 return (src);
565 }
566
567 /*
568 * Checks if we need to switch from STALE state.
569 *
570 * RFC 4861 requires switching from STALE to DELAY state
571 * on first packet matching entry, waiting V_nd6_delay and
572 * transition to PROBE state (if upper layer confirmation was
573 * not received).
574 *
575 * This code performs a bit differently:
576 * On packet hit we don't change state (but desired state
577 * can be guessed by control plane). However, after V_nd6_delay
578 * seconds code will transition to PROBE state (so DELAY state
579 * is kinda skipped in most situations).
580 *
581 * Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
582 * we perform the following upon entering STALE state:
583 *
584 * 1) Arm timer to run each V_nd6_delay seconds to make sure that
585 * if packet was transmitted at the start of given interval, we
586 * would be able to switch to PROBE state in V_nd6_delay seconds
587 * as user expects.
588 *
589 * 2) Reschedule timer until original V_nd6_gctimer expires keeping
590 * lle in STALE state (remaining timer value stored in lle_remtime).
591 *
592 * 3) Reschedule timer if packet was transmitted less that V_nd6_delay
593 * seconds ago.
594 *
595 * Returns non-zero value if the entry is still STALE (storing
596 * the next timer interval in @pdelay).
597 *
598 * Returns zero value if original timer expired or we need to switch to
599 * PROBE (store that in @do_switch variable).
600 */
601 static int
nd6_is_stale(struct llentry * lle,long * pdelay,int * do_switch)602 nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
603 {
604 int nd_delay, nd_gctimer, r_skip_req;
605 time_t lle_hittime;
606 long delay;
607
608 *do_switch = 0;
609 nd_gctimer = V_nd6_gctimer;
610 nd_delay = V_nd6_delay;
611
612 LLE_REQ_LOCK(lle);
613 r_skip_req = lle->r_skip_req;
614 lle_hittime = lle->lle_hittime;
615 LLE_REQ_UNLOCK(lle);
616
617 if (r_skip_req > 0) {
618
619 /*
620 * Nonzero r_skip_req value was set upon entering
621 * STALE state. Since value was not changed, no
622 * packets were passed using this lle. Ask for
623 * timer reschedule and keep STALE state.
624 */
625 delay = (long)(MIN(nd_gctimer, nd_delay));
626 delay *= hz;
627 if (lle->lle_remtime > delay)
628 lle->lle_remtime -= delay;
629 else {
630 delay = lle->lle_remtime;
631 lle->lle_remtime = 0;
632 }
633
634 if (delay == 0) {
635
636 /*
637 * The original ng6_gctime timeout ended,
638 * no more rescheduling.
639 */
640 return (0);
641 }
642
643 *pdelay = delay;
644 return (1);
645 }
646
647 /*
648 * Packet received. Verify timestamp
649 */
650 delay = (long)(time_uptime - lle_hittime);
651 if (delay < nd_delay) {
652
653 /*
654 * V_nd6_delay still not passed since the first
655 * hit in STALE state.
656 * Reshedule timer and return.
657 */
658 *pdelay = (long)(nd_delay - delay) * hz;
659 return (1);
660 }
661
662 /* Request switching to probe */
663 *do_switch = 1;
664 return (0);
665 }
666
667
668 /*
669 * Switch @lle state to new state optionally arming timers.
670 *
671 * Set noinline to be dtrace-friendly
672 */
673 __noinline void
nd6_llinfo_setstate(struct llentry * lle,int newstate)674 nd6_llinfo_setstate(struct llentry *lle, int newstate)
675 {
676 struct ifnet *ifp;
677 int nd_gctimer, nd_delay;
678 long delay, remtime;
679
680 delay = 0;
681 remtime = 0;
682
683 switch (newstate) {
684 case ND6_LLINFO_INCOMPLETE:
685 ifp = lle->lle_tbl->llt_ifp;
686 delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000;
687 break;
688 case ND6_LLINFO_REACHABLE:
689 if (!ND6_LLINFO_PERMANENT(lle)) {
690 ifp = lle->lle_tbl->llt_ifp;
691 delay = (long)ND_IFINFO(ifp)->reachable * hz;
692 }
693 break;
694 case ND6_LLINFO_STALE:
695
696 /*
697 * Notify fast path that we want to know if any packet
698 * is transmitted by setting r_skip_req.
699 */
700 LLE_REQ_LOCK(lle);
701 lle->r_skip_req = 1;
702 LLE_REQ_UNLOCK(lle);
703 nd_delay = V_nd6_delay;
704 nd_gctimer = V_nd6_gctimer;
705
706 delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
707 remtime = (long)nd_gctimer * hz - delay;
708 break;
709 case ND6_LLINFO_DELAY:
710 lle->la_asked = 0;
711 delay = (long)V_nd6_delay * hz;
712 break;
713 }
714
715 if (delay > 0)
716 nd6_llinfo_settimer_locked(lle, delay);
717
718 lle->lle_remtime = remtime;
719 lle->ln_state = newstate;
720 }
721
722 /*
723 * Timer-dependent part of nd state machine.
724 *
725 * Set noinline to be dtrace-friendly
726 */
727 static __noinline void
nd6_llinfo_timer(void * arg)728 nd6_llinfo_timer(void *arg)
729 {
730 struct llentry *ln;
731 struct in6_addr *dst, *pdst, *psrc, src;
732 struct ifnet *ifp;
733 struct nd_ifinfo *ndi;
734 int do_switch, send_ns;
735 long delay;
736
737 KASSERT(arg != NULL, ("%s: arg NULL", __func__));
738 ln = (struct llentry *)arg;
739 ifp = lltable_get_ifp(ln->lle_tbl);
740 CURVNET_SET(ifp->if_vnet);
741
742 ND6_RLOCK();
743 LLE_WLOCK(ln);
744 if (callout_pending(&ln->lle_timer)) {
745 /*
746 * Here we are a bit odd here in the treatment of
747 * active/pending. If the pending bit is set, it got
748 * rescheduled before I ran. The active
749 * bit we ignore, since if it was stopped
750 * in ll_tablefree() and was currently running
751 * it would have return 0 so the code would
752 * not have deleted it since the callout could
753 * not be stopped so we want to go through
754 * with the delete here now. If the callout
755 * was restarted, the pending bit will be back on and
756 * we just want to bail since the callout_reset would
757 * return 1 and our reference would have been removed
758 * by nd6_llinfo_settimer_locked above since canceled
759 * would have been 1.
760 */
761 LLE_WUNLOCK(ln);
762 ND6_RUNLOCK();
763 CURVNET_RESTORE();
764 return;
765 }
766 ndi = ND_IFINFO(ifp);
767 send_ns = 0;
768 dst = &ln->r_l3addr.addr6;
769 pdst = dst;
770
771 if (ln->ln_ntick > 0) {
772 if (ln->ln_ntick > INT_MAX) {
773 ln->ln_ntick -= INT_MAX;
774 nd6_llinfo_settimer_locked(ln, INT_MAX);
775 } else {
776 ln->ln_ntick = 0;
777 nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
778 }
779 goto done;
780 }
781
782 if (ln->la_flags & LLE_STATIC) {
783 goto done;
784 }
785
786 if (ln->la_flags & LLE_DELETED) {
787 nd6_free(&ln, 0);
788 goto done;
789 }
790
791 switch (ln->ln_state) {
792 case ND6_LLINFO_INCOMPLETE:
793 if (ln->la_asked < V_nd6_mmaxtries) {
794 ln->la_asked++;
795 send_ns = 1;
796 /* Send NS to multicast address */
797 pdst = NULL;
798 } else {
799 struct mbuf *m = ln->la_hold;
800 if (m) {
801 struct mbuf *m0;
802
803 /*
804 * assuming every packet in la_hold has the
805 * same IP header. Send error after unlock.
806 */
807 m0 = m->m_nextpkt;
808 m->m_nextpkt = NULL;
809 ln->la_hold = m0;
810 clear_llinfo_pqueue(ln);
811 }
812 nd6_free(&ln, 0);
813 if (m != NULL)
814 icmp6_error2(m, ICMP6_DST_UNREACH,
815 ICMP6_DST_UNREACH_ADDR, 0, ifp);
816 }
817 break;
818 case ND6_LLINFO_REACHABLE:
819 if (!ND6_LLINFO_PERMANENT(ln))
820 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
821 break;
822
823 case ND6_LLINFO_STALE:
824 if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
825
826 /*
827 * No packet has used this entry and GC timeout
828 * has not been passed. Reshedule timer and
829 * return.
830 */
831 nd6_llinfo_settimer_locked(ln, delay);
832 break;
833 }
834
835 if (do_switch == 0) {
836
837 /*
838 * GC timer has ended and entry hasn't been used.
839 * Run Garbage collector (RFC 4861, 5.3)
840 */
841 if (!ND6_LLINFO_PERMANENT(ln))
842 nd6_free(&ln, 1);
843 break;
844 }
845
846 /* Entry has been used AND delay timer has ended. */
847
848 /* FALLTHROUGH */
849
850 case ND6_LLINFO_DELAY:
851 if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
852 /* We need NUD */
853 ln->la_asked = 1;
854 nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
855 send_ns = 1;
856 } else
857 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
858 break;
859 case ND6_LLINFO_PROBE:
860 if (ln->la_asked < V_nd6_umaxtries) {
861 ln->la_asked++;
862 send_ns = 1;
863 } else {
864 nd6_free(&ln, 0);
865 }
866 break;
867 default:
868 panic("%s: paths in a dark night can be confusing: %d",
869 __func__, ln->ln_state);
870 }
871 done:
872 if (ln != NULL)
873 ND6_RUNLOCK();
874 if (send_ns != 0) {
875 nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
876 psrc = nd6_llinfo_get_holdsrc(ln, &src);
877 LLE_FREE_LOCKED(ln);
878 ln = NULL;
879 nd6_ns_output(ifp, psrc, pdst, dst, NULL);
880 }
881
882 if (ln != NULL)
883 LLE_FREE_LOCKED(ln);
884 CURVNET_RESTORE();
885 }
886
887
888 /*
889 * ND6 timer routine to expire default route list and prefix list
890 */
891 void
nd6_timer(void * arg)892 nd6_timer(void *arg)
893 {
894 CURVNET_SET((struct vnet *) arg);
895 struct nd_drhead drq;
896 struct nd_prhead prl;
897 struct nd_defrouter *dr, *ndr;
898 struct nd_prefix *pr, *npr;
899 struct ifnet *ifp;
900 struct in6_ifaddr *ia6, *nia6;
901 uint64_t genid;
902
903 TAILQ_INIT(&drq);
904 LIST_INIT(&prl);
905
906 ND6_WLOCK();
907 TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr)
908 if (dr->expire && dr->expire < time_uptime)
909 defrouter_unlink(dr, &drq);
910 ND6_WUNLOCK();
911
912 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
913 TAILQ_REMOVE(&drq, dr, dr_entry);
914 defrouter_del(dr);
915 }
916
917 /*
918 * expire interface addresses.
919 * in the past the loop was inside prefix expiry processing.
920 * However, from a stricter speci-confrmance standpoint, we should
921 * rather separate address lifetimes and prefix lifetimes.
922 *
923 * XXXRW: in6_ifaddrhead locking.
924 */
925 addrloop:
926 CK_STAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
927 /* check address lifetime */
928 if (IFA6_IS_INVALID(ia6)) {
929 int regen = 0;
930
931 /*
932 * If the expiring address is temporary, try
933 * regenerating a new one. This would be useful when
934 * we suspended a laptop PC, then turned it on after a
935 * period that could invalidate all temporary
936 * addresses. Although we may have to restart the
937 * loop (see below), it must be after purging the
938 * address. Otherwise, we'd see an infinite loop of
939 * regeneration.
940 */
941 if (V_ip6_use_tempaddr &&
942 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
943 if (regen_tmpaddr(ia6) == 0)
944 regen = 1;
945 }
946
947 in6_purgeaddr(&ia6->ia_ifa);
948
949 if (regen)
950 goto addrloop; /* XXX: see below */
951 } else if (IFA6_IS_DEPRECATED(ia6)) {
952 int oldflags = ia6->ia6_flags;
953
954 ia6->ia6_flags |= IN6_IFF_DEPRECATED;
955
956 /*
957 * If a temporary address has just become deprecated,
958 * regenerate a new one if possible.
959 */
960 if (V_ip6_use_tempaddr &&
961 (ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
962 (oldflags & IN6_IFF_DEPRECATED) == 0) {
963
964 if (regen_tmpaddr(ia6) == 0) {
965 /*
966 * A new temporary address is
967 * generated.
968 * XXX: this means the address chain
969 * has changed while we are still in
970 * the loop. Although the change
971 * would not cause disaster (because
972 * it's not a deletion, but an
973 * addition,) we'd rather restart the
974 * loop just for safety. Or does this
975 * significantly reduce performance??
976 */
977 goto addrloop;
978 }
979 }
980 } else if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
981 /*
982 * Schedule DAD for a tentative address. This happens
983 * if the interface was down or not running
984 * when the address was configured.
985 */
986 int delay;
987
988 delay = arc4random() %
989 (MAX_RTR_SOLICITATION_DELAY * hz);
990 nd6_dad_start((struct ifaddr *)ia6, delay);
991 } else {
992 /*
993 * Check status of the interface. If it is down,
994 * mark the address as tentative for future DAD.
995 */
996 ifp = ia6->ia_ifp;
997 if ((ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0 &&
998 ((ifp->if_flags & IFF_UP) == 0 ||
999 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
1000 (ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0)){
1001 ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
1002 ia6->ia6_flags |= IN6_IFF_TENTATIVE;
1003 }
1004
1005 /*
1006 * A new RA might have made a deprecated address
1007 * preferred.
1008 */
1009 ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
1010 }
1011 }
1012
1013 ND6_WLOCK();
1014 restart:
1015 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1016 /*
1017 * Expire prefixes. Since the pltime is only used for
1018 * autoconfigured addresses, pltime processing for prefixes is
1019 * not necessary.
1020 *
1021 * Only unlink after all derived addresses have expired. This
1022 * may not occur until two hours after the prefix has expired
1023 * per RFC 4862. If the prefix expires before its derived
1024 * addresses, mark it off-link. This will be done automatically
1025 * after unlinking if no address references remain.
1026 */
1027 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME ||
1028 time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime)
1029 continue;
1030
1031 if (pr->ndpr_addrcnt == 0) {
1032 nd6_prefix_unlink(pr, &prl);
1033 continue;
1034 }
1035 if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
1036 genid = V_nd6_list_genid;
1037 nd6_prefix_ref(pr);
1038 ND6_WUNLOCK();
1039 ND6_ONLINK_LOCK();
1040 (void)nd6_prefix_offlink(pr);
1041 ND6_ONLINK_UNLOCK();
1042 ND6_WLOCK();
1043 nd6_prefix_rele(pr);
1044 if (genid != V_nd6_list_genid)
1045 goto restart;
1046 }
1047 }
1048 ND6_WUNLOCK();
1049
1050 while ((pr = LIST_FIRST(&prl)) != NULL) {
1051 LIST_REMOVE(pr, ndpr_entry);
1052 nd6_prefix_del(pr);
1053 }
1054
1055 callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
1056 nd6_timer, curvnet);
1057
1058 CURVNET_RESTORE();
1059 }
1060
1061 /*
1062 * ia6 - deprecated/invalidated temporary address
1063 */
1064 static int
regen_tmpaddr(struct in6_ifaddr * ia6)1065 regen_tmpaddr(struct in6_ifaddr *ia6)
1066 {
1067 struct ifaddr *ifa;
1068 struct ifnet *ifp;
1069 struct in6_ifaddr *public_ifa6 = NULL;
1070
1071 ifp = ia6->ia_ifa.ifa_ifp;
1072 IF_ADDR_RLOCK(ifp);
1073 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1074 struct in6_ifaddr *it6;
1075
1076 if (ifa->ifa_addr->sa_family != AF_INET6)
1077 continue;
1078
1079 it6 = (struct in6_ifaddr *)ifa;
1080
1081 /* ignore no autoconf addresses. */
1082 if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1083 continue;
1084
1085 /* ignore autoconf addresses with different prefixes. */
1086 if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
1087 continue;
1088
1089 /*
1090 * Now we are looking at an autoconf address with the same
1091 * prefix as ours. If the address is temporary and is still
1092 * preferred, do not create another one. It would be rare, but
1093 * could happen, for example, when we resume a laptop PC after
1094 * a long period.
1095 */
1096 if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
1097 !IFA6_IS_DEPRECATED(it6)) {
1098 public_ifa6 = NULL;
1099 break;
1100 }
1101
1102 /*
1103 * This is a public autoconf address that has the same prefix
1104 * as ours. If it is preferred, keep it. We can't break the
1105 * loop here, because there may be a still-preferred temporary
1106 * address with the prefix.
1107 */
1108 if (!IFA6_IS_DEPRECATED(it6))
1109 public_ifa6 = it6;
1110 }
1111 if (public_ifa6 != NULL)
1112 ifa_ref(&public_ifa6->ia_ifa);
1113 IF_ADDR_RUNLOCK(ifp);
1114
1115 if (public_ifa6 != NULL) {
1116 int e;
1117
1118 if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
1119 ifa_free(&public_ifa6->ia_ifa);
1120 log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
1121 " tmp addr,errno=%d\n", e);
1122 return (-1);
1123 }
1124 ifa_free(&public_ifa6->ia_ifa);
1125 return (0);
1126 }
1127
1128 return (-1);
1129 }
1130
1131 /*
1132 * Remove prefix and default router list entries corresponding to ifp. Neighbor
1133 * cache entries are freed in in6_domifdetach().
1134 */
1135 void
nd6_purge(struct ifnet * ifp)1136 nd6_purge(struct ifnet *ifp)
1137 {
1138 struct nd_drhead drq;
1139 struct nd_prhead prl;
1140 struct nd_defrouter *dr, *ndr;
1141 struct nd_prefix *pr, *npr;
1142
1143 TAILQ_INIT(&drq);
1144 LIST_INIT(&prl);
1145
1146 /*
1147 * Nuke default router list entries toward ifp.
1148 * We defer removal of default router list entries that is installed
1149 * in the routing table, in order to keep additional side effects as
1150 * small as possible.
1151 */
1152 ND6_WLOCK();
1153 TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
1154 if (dr->installed)
1155 continue;
1156 if (dr->ifp == ifp)
1157 defrouter_unlink(dr, &drq);
1158 }
1159 TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
1160 if (!dr->installed)
1161 continue;
1162 if (dr->ifp == ifp)
1163 defrouter_unlink(dr, &drq);
1164 }
1165
1166 /*
1167 * Remove prefixes on ifp. We should have already removed addresses on
1168 * this interface, so no addresses should be referencing these prefixes.
1169 */
1170 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
1171 if (pr->ndpr_ifp == ifp)
1172 nd6_prefix_unlink(pr, &prl);
1173 }
1174 ND6_WUNLOCK();
1175
1176 /* Delete the unlinked router and prefix objects. */
1177 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
1178 TAILQ_REMOVE(&drq, dr, dr_entry);
1179 defrouter_del(dr);
1180 }
1181 while ((pr = LIST_FIRST(&prl)) != NULL) {
1182 LIST_REMOVE(pr, ndpr_entry);
1183 nd6_prefix_del(pr);
1184 }
1185
1186 /* cancel default outgoing interface setting */
1187 if (V_nd6_defifindex == ifp->if_index)
1188 nd6_setdefaultiface(0);
1189
1190 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1191 /* Refresh default router list. */
1192 defrouter_select_fib(ifp->if_fib);
1193 }
1194 }
1195
1196 /*
1197 * the caller acquires and releases the lock on the lltbls
1198 * Returns the llentry locked
1199 */
1200 struct llentry *
nd6_lookup(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1201 nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1202 {
1203 struct sockaddr_in6 sin6;
1204 struct llentry *ln;
1205
1206 bzero(&sin6, sizeof(sin6));
1207 sin6.sin6_len = sizeof(struct sockaddr_in6);
1208 sin6.sin6_family = AF_INET6;
1209 sin6.sin6_addr = *addr6;
1210
1211 IF_AFDATA_LOCK_ASSERT(ifp);
1212
1213 ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
1214
1215 return (ln);
1216 }
1217
1218 struct llentry *
nd6_alloc(const struct in6_addr * addr6,int flags,struct ifnet * ifp)1219 nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
1220 {
1221 struct sockaddr_in6 sin6;
1222 struct llentry *ln;
1223
1224 bzero(&sin6, sizeof(sin6));
1225 sin6.sin6_len = sizeof(struct sockaddr_in6);
1226 sin6.sin6_family = AF_INET6;
1227 sin6.sin6_addr = *addr6;
1228
1229 ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
1230 if (ln != NULL)
1231 ln->ln_state = ND6_LLINFO_NOSTATE;
1232
1233 return (ln);
1234 }
1235
1236 /*
1237 * Test whether a given IPv6 address is a neighbor or not, ignoring
1238 * the actual neighbor cache. The neighbor cache is ignored in order
1239 * to not reenter the routing code from within itself.
1240 */
1241 static int
nd6_is_new_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1242 nd6_is_new_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1243 {
1244 struct nd_prefix *pr;
1245 struct ifaddr *ifa;
1246 struct rt_addrinfo info;
1247 struct sockaddr_in6 rt_key;
1248 const struct sockaddr *dst6;
1249 uint64_t genid;
1250 int error, fibnum;
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
1275 bzero(&rt_key, sizeof(rt_key));
1276 bzero(&info, sizeof(info));
1277 info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key;
1278
1279 /*
1280 * If the address matches one of our addresses,
1281 * it should be a neighbor.
1282 * If the address matches one of our on-link prefixes, it should be a
1283 * neighbor.
1284 */
1285 ND6_RLOCK();
1286 restart:
1287 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
1288 if (pr->ndpr_ifp != ifp)
1289 continue;
1290
1291 if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
1292 dst6 = (const struct sockaddr *)&pr->ndpr_prefix;
1293
1294 /*
1295 * We only need to check all FIBs if add_addr_allfibs
1296 * is unset. If set, checking any FIB will suffice.
1297 */
1298 fibnum = V_rt_add_addr_allfibs ? rt_numfibs - 1 : 0;
1299 for (; fibnum < rt_numfibs; fibnum++) {
1300 genid = V_nd6_list_genid;
1301 ND6_RUNLOCK();
1302
1303 /*
1304 * Restore length field before
1305 * retrying lookup
1306 */
1307 rt_key.sin6_len = sizeof(rt_key);
1308 error = rib_lookup_info(fibnum, dst6, 0, 0,
1309 &info);
1310
1311 ND6_RLOCK();
1312 if (genid != V_nd6_list_genid)
1313 goto restart;
1314 if (error == 0)
1315 break;
1316 }
1317 if (error != 0)
1318 continue;
1319
1320 /*
1321 * This is the case where multiple interfaces
1322 * have the same prefix, but only one is installed
1323 * into the routing table and that prefix entry
1324 * is not the one being examined here. In the case
1325 * where RADIX_MPATH is enabled, multiple route
1326 * entries (of the same rt_key value) will be
1327 * installed because the interface addresses all
1328 * differ.
1329 */
1330 if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1331 &rt_key.sin6_addr))
1332 continue;
1333 }
1334
1335 if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
1336 &addr->sin6_addr, &pr->ndpr_mask)) {
1337 ND6_RUNLOCK();
1338 return (1);
1339 }
1340 }
1341 ND6_RUNLOCK();
1342
1343 /*
1344 * If the address is assigned on the node of the other side of
1345 * a p2p interface, the address should be a neighbor.
1346 */
1347 if (ifp->if_flags & IFF_POINTOPOINT) {
1348 IF_ADDR_RLOCK(ifp);
1349 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1350 if (ifa->ifa_addr->sa_family != addr->sin6_family)
1351 continue;
1352 if (ifa->ifa_dstaddr != NULL &&
1353 sa_equal(addr, ifa->ifa_dstaddr)) {
1354 IF_ADDR_RUNLOCK(ifp);
1355 return 1;
1356 }
1357 }
1358 IF_ADDR_RUNLOCK(ifp);
1359 }
1360
1361 /*
1362 * If the default router list is empty, all addresses are regarded
1363 * as on-link, and thus, as a neighbor.
1364 */
1365 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
1366 TAILQ_EMPTY(&V_nd_defrouter) &&
1367 V_nd6_defifindex == ifp->if_index) {
1368 return (1);
1369 }
1370
1371 return (0);
1372 }
1373
1374
1375 /*
1376 * Detect if a given IPv6 address identifies a neighbor on a given link.
1377 * XXX: should take care of the destination of a p2p link?
1378 */
1379 int
nd6_is_addr_neighbor(const struct sockaddr_in6 * addr,struct ifnet * ifp)1380 nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
1381 {
1382 struct llentry *lle;
1383 int rc = 0;
1384
1385 IF_AFDATA_UNLOCK_ASSERT(ifp);
1386 if (nd6_is_new_addr_neighbor(addr, ifp))
1387 return (1);
1388
1389 /*
1390 * Even if the address matches none of our addresses, it might be
1391 * in the neighbor cache.
1392 */
1393 IF_AFDATA_RLOCK(ifp);
1394 if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
1395 LLE_RUNLOCK(lle);
1396 rc = 1;
1397 }
1398 IF_AFDATA_RUNLOCK(ifp);
1399 return (rc);
1400 }
1401
1402 /*
1403 * Free an nd6 llinfo entry.
1404 * Since the function would cause significant changes in the kernel, DO NOT
1405 * make it global, unless you have a strong reason for the change, and are sure
1406 * that the change is safe.
1407 *
1408 * Set noinline to be dtrace-friendly
1409 */
1410 static __noinline void
nd6_free(struct llentry ** lnp,int gc)1411 nd6_free(struct llentry **lnp, int gc)
1412 {
1413 struct ifnet *ifp;
1414 struct llentry *ln;
1415 struct nd_defrouter *dr;
1416
1417 ln = *lnp;
1418 *lnp = NULL;
1419
1420 LLE_WLOCK_ASSERT(ln);
1421 ND6_RLOCK_ASSERT();
1422
1423 ifp = lltable_get_ifp(ln->lle_tbl);
1424 if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0)
1425 dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
1426 else
1427 dr = NULL;
1428 ND6_RUNLOCK();
1429
1430 if ((ln->la_flags & LLE_DELETED) == 0)
1431 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
1432
1433 /*
1434 * we used to have pfctlinput(PRC_HOSTDEAD) here.
1435 * even though it is not harmful, it was not really necessary.
1436 */
1437
1438 /* cancel timer */
1439 nd6_llinfo_settimer_locked(ln, -1);
1440
1441 if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
1442 if (dr != NULL && dr->expire &&
1443 ln->ln_state == ND6_LLINFO_STALE && gc) {
1444 /*
1445 * If the reason for the deletion is just garbage
1446 * collection, and the neighbor is an active default
1447 * router, do not delete it. Instead, reset the GC
1448 * timer using the router's lifetime.
1449 * Simply deleting the entry would affect default
1450 * router selection, which is not necessarily a good
1451 * thing, especially when we're using router preference
1452 * values.
1453 * XXX: the check for ln_state would be redundant,
1454 * but we intentionally keep it just in case.
1455 */
1456 if (dr->expire > time_uptime)
1457 nd6_llinfo_settimer_locked(ln,
1458 (dr->expire - time_uptime) * hz);
1459 else
1460 nd6_llinfo_settimer_locked(ln,
1461 (long)V_nd6_gctimer * hz);
1462
1463 LLE_REMREF(ln);
1464 LLE_WUNLOCK(ln);
1465 defrouter_rele(dr);
1466 return;
1467 }
1468
1469 if (dr) {
1470 /*
1471 * Unreachablity of a router might affect the default
1472 * router selection and on-link detection of advertised
1473 * prefixes.
1474 */
1475
1476 /*
1477 * Temporarily fake the state to choose a new default
1478 * router and to perform on-link determination of
1479 * prefixes correctly.
1480 * Below the state will be set correctly,
1481 * or the entry itself will be deleted.
1482 */
1483 ln->ln_state = ND6_LLINFO_INCOMPLETE;
1484 }
1485
1486 if (ln->ln_router || dr) {
1487
1488 /*
1489 * We need to unlock to avoid a LOR with rt6_flush() with the
1490 * rnh and for the calls to pfxlist_onlink_check() and
1491 * defrouter_select_fib() in the block further down for calls
1492 * into nd6_lookup(). We still hold a ref.
1493 */
1494 LLE_WUNLOCK(ln);
1495
1496 /*
1497 * rt6_flush must be called whether or not the neighbor
1498 * is in the Default Router List.
1499 * See a corresponding comment in nd6_na_input().
1500 */
1501 rt6_flush(&ln->r_l3addr.addr6, ifp);
1502 }
1503
1504 if (dr) {
1505 /*
1506 * Since defrouter_select_fib() does not affect the
1507 * on-link determination and MIP6 needs the check
1508 * before the default router selection, we perform
1509 * the check now.
1510 */
1511 pfxlist_onlink_check();
1512
1513 /*
1514 * Refresh default router list.
1515 */
1516 defrouter_select_fib(dr->ifp->if_fib);
1517 }
1518
1519 /*
1520 * If this entry was added by an on-link redirect, remove the
1521 * corresponding host route.
1522 */
1523 if (ln->la_flags & LLE_REDIRECT)
1524 nd6_free_redirect(ln);
1525
1526 if (ln->ln_router || dr)
1527 LLE_WLOCK(ln);
1528 }
1529
1530 /*
1531 * Save to unlock. We still hold an extra reference and will not
1532 * free(9) in llentry_free() if someone else holds one as well.
1533 */
1534 LLE_WUNLOCK(ln);
1535 IF_AFDATA_LOCK(ifp);
1536 LLE_WLOCK(ln);
1537 /* Guard against race with other llentry_free(). */
1538 if (ln->la_flags & LLE_LINKED) {
1539 /* Remove callout reference */
1540 LLE_REMREF(ln);
1541 lltable_unlink_entry(ln->lle_tbl, ln);
1542 }
1543 IF_AFDATA_UNLOCK(ifp);
1544
1545 llentry_free(ln);
1546 if (dr != NULL)
1547 defrouter_rele(dr);
1548 }
1549
1550 static int
nd6_isdynrte(const struct rtentry * rt,void * xap)1551 nd6_isdynrte(const struct rtentry *rt, void *xap)
1552 {
1553
1554 if (rt->rt_flags == (RTF_UP | RTF_HOST | RTF_DYNAMIC))
1555 return (1);
1556
1557 return (0);
1558 }
1559 /*
1560 * Remove the rtentry for the given llentry,
1561 * both of which were installed by a redirect.
1562 */
1563 static void
nd6_free_redirect(const struct llentry * ln)1564 nd6_free_redirect(const struct llentry *ln)
1565 {
1566 int fibnum;
1567 struct sockaddr_in6 sin6;
1568 struct rt_addrinfo info;
1569
1570 lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
1571 memset(&info, 0, sizeof(info));
1572 info.rti_info[RTAX_DST] = (struct sockaddr *)&sin6;
1573 info.rti_filter = nd6_isdynrte;
1574
1575 for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
1576 rtrequest1_fib(RTM_DELETE, &info, NULL, fibnum);
1577 }
1578
1579 /*
1580 * Rejuvenate this function for routing operations related
1581 * processing.
1582 */
1583 void
nd6_rtrequest(int req,struct rtentry * rt,struct rt_addrinfo * info)1584 nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
1585 {
1586 struct sockaddr_in6 *gateway;
1587 struct nd_defrouter *dr;
1588 struct ifnet *ifp;
1589
1590 gateway = (struct sockaddr_in6 *)rt->rt_gateway;
1591 ifp = rt->rt_ifp;
1592
1593 switch (req) {
1594 case RTM_ADD:
1595 break;
1596
1597 case RTM_DELETE:
1598 if (!ifp)
1599 return;
1600 /*
1601 * Only indirect routes are interesting.
1602 */
1603 if ((rt->rt_flags & RTF_GATEWAY) == 0)
1604 return;
1605 /*
1606 * check for default route
1607 */
1608 if (IN6_ARE_ADDR_EQUAL(&in6addr_any,
1609 &SIN6(rt_key(rt))->sin6_addr)) {
1610 dr = defrouter_lookup(&gateway->sin6_addr, ifp);
1611 if (dr != NULL) {
1612 dr->installed = 0;
1613 defrouter_rele(dr);
1614 }
1615 }
1616 break;
1617 }
1618 }
1619
1620
1621 int
nd6_ioctl(u_long cmd,caddr_t data,struct ifnet * ifp)1622 nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
1623 {
1624 struct in6_ndireq *ndi = (struct in6_ndireq *)data;
1625 struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
1626 struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
1627 int error = 0;
1628
1629 if (ifp->if_afdata[AF_INET6] == NULL)
1630 return (EPFNOSUPPORT);
1631 switch (cmd) {
1632 case OSIOCGIFINFO_IN6:
1633 #define ND ndi->ndi
1634 /* XXX: old ndp(8) assumes a positive value for linkmtu. */
1635 bzero(&ND, sizeof(ND));
1636 ND.linkmtu = IN6_LINKMTU(ifp);
1637 ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
1638 ND.basereachable = ND_IFINFO(ifp)->basereachable;
1639 ND.reachable = ND_IFINFO(ifp)->reachable;
1640 ND.retrans = ND_IFINFO(ifp)->retrans;
1641 ND.flags = ND_IFINFO(ifp)->flags;
1642 ND.recalctm = ND_IFINFO(ifp)->recalctm;
1643 ND.chlim = ND_IFINFO(ifp)->chlim;
1644 break;
1645 case SIOCGIFINFO_IN6:
1646 ND = *ND_IFINFO(ifp);
1647 break;
1648 case SIOCSIFINFO_IN6:
1649 /*
1650 * used to change host variables from userland.
1651 * intended for a use on router to reflect RA configurations.
1652 */
1653 /* 0 means 'unspecified' */
1654 if (ND.linkmtu != 0) {
1655 if (ND.linkmtu < IPV6_MMTU ||
1656 ND.linkmtu > IN6_LINKMTU(ifp)) {
1657 error = EINVAL;
1658 break;
1659 }
1660 ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
1661 }
1662
1663 if (ND.basereachable != 0) {
1664 int obasereachable = ND_IFINFO(ifp)->basereachable;
1665
1666 ND_IFINFO(ifp)->basereachable = ND.basereachable;
1667 if (ND.basereachable != obasereachable)
1668 ND_IFINFO(ifp)->reachable =
1669 ND_COMPUTE_RTIME(ND.basereachable);
1670 }
1671 if (ND.retrans != 0)
1672 ND_IFINFO(ifp)->retrans = ND.retrans;
1673 if (ND.chlim != 0)
1674 ND_IFINFO(ifp)->chlim = ND.chlim;
1675 /* FALLTHROUGH */
1676 case SIOCSIFINFO_FLAGS:
1677 {
1678 struct ifaddr *ifa;
1679 struct in6_ifaddr *ia;
1680
1681 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1682 !(ND.flags & ND6_IFF_IFDISABLED)) {
1683 /* ifdisabled 1->0 transision */
1684
1685 /*
1686 * If the interface is marked as ND6_IFF_IFDISABLED and
1687 * has an link-local address with IN6_IFF_DUPLICATED,
1688 * do not clear ND6_IFF_IFDISABLED.
1689 * See RFC 4862, Section 5.4.5.
1690 */
1691 IF_ADDR_RLOCK(ifp);
1692 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
1693 if (ifa->ifa_addr->sa_family != AF_INET6)
1694 continue;
1695 ia = (struct in6_ifaddr *)ifa;
1696 if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
1697 IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1698 break;
1699 }
1700 IF_ADDR_RUNLOCK(ifp);
1701
1702 if (ifa != NULL) {
1703 /* LLA is duplicated. */
1704 ND.flags |= ND6_IFF_IFDISABLED;
1705 log(LOG_ERR, "Cannot enable an interface"
1706 " with a link-local address marked"
1707 " duplicate.\n");
1708 } else {
1709 ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
1710 if (ifp->if_flags & IFF_UP)
1711 in6_if_up(ifp);
1712 }
1713 } else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
1714 (ND.flags & ND6_IFF_IFDISABLED)) {
1715 /* ifdisabled 0->1 transision */
1716 /* Mark all IPv6 address as tentative. */
1717
1718 ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
1719 if (V_ip6_dad_count > 0 &&
1720 (ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
1721 IF_ADDR_RLOCK(ifp);
1722 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1723 ifa_link) {
1724 if (ifa->ifa_addr->sa_family !=
1725 AF_INET6)
1726 continue;
1727 ia = (struct in6_ifaddr *)ifa;
1728 ia->ia6_flags |= IN6_IFF_TENTATIVE;
1729 }
1730 IF_ADDR_RUNLOCK(ifp);
1731 }
1732 }
1733
1734 if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
1735 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL)) {
1736 /* auto_linklocal 0->1 transision */
1737
1738 /* If no link-local address on ifp, configure */
1739 ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
1740 in6_ifattach(ifp, NULL);
1741 } else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
1742 ifp->if_flags & IFF_UP) {
1743 /*
1744 * When the IF already has
1745 * ND6_IFF_AUTO_LINKLOCAL, no link-local
1746 * address is assigned, and IFF_UP, try to
1747 * assign one.
1748 */
1749 IF_ADDR_RLOCK(ifp);
1750 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
1751 ifa_link) {
1752 if (ifa->ifa_addr->sa_family !=
1753 AF_INET6)
1754 continue;
1755 ia = (struct in6_ifaddr *)ifa;
1756 if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
1757 break;
1758 }
1759 IF_ADDR_RUNLOCK(ifp);
1760 if (ifa != NULL)
1761 /* No LLA is configured. */
1762 in6_ifattach(ifp, NULL);
1763 }
1764 }
1765 }
1766 ND_IFINFO(ifp)->flags = ND.flags;
1767 break;
1768 #undef ND
1769 case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */
1770 /* sync kernel routing table with the default router list */
1771 defrouter_reset();
1772 defrouter_select();
1773 break;
1774 case SIOCSPFXFLUSH_IN6:
1775 {
1776 /* flush all the prefix advertised by routers */
1777 struct in6_ifaddr *ia, *ia_next;
1778 struct nd_prefix *pr, *next;
1779 struct nd_prhead prl;
1780
1781 LIST_INIT(&prl);
1782
1783 ND6_WLOCK();
1784 LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
1785 if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
1786 continue; /* XXX */
1787 nd6_prefix_unlink(pr, &prl);
1788 }
1789 ND6_WUNLOCK();
1790
1791 while ((pr = LIST_FIRST(&prl)) != NULL) {
1792 LIST_REMOVE(pr, ndpr_entry);
1793 /* XXXRW: in6_ifaddrhead locking. */
1794 CK_STAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
1795 ia_next) {
1796 if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
1797 continue;
1798
1799 if (ia->ia6_ndpr == pr)
1800 in6_purgeaddr(&ia->ia_ifa);
1801 }
1802 nd6_prefix_del(pr);
1803 }
1804 break;
1805 }
1806 case SIOCSRTRFLUSH_IN6:
1807 {
1808 /* flush all the default routers */
1809 struct nd_drhead drq;
1810 struct nd_defrouter *dr;
1811
1812 TAILQ_INIT(&drq);
1813
1814 defrouter_reset();
1815
1816 ND6_WLOCK();
1817 while ((dr = TAILQ_FIRST(&V_nd_defrouter)) != NULL)
1818 defrouter_unlink(dr, &drq);
1819 ND6_WUNLOCK();
1820 while ((dr = TAILQ_FIRST(&drq)) != NULL) {
1821 TAILQ_REMOVE(&drq, dr, dr_entry);
1822 defrouter_del(dr);
1823 }
1824
1825 defrouter_select();
1826 break;
1827 }
1828 case SIOCGNBRINFO_IN6:
1829 {
1830 struct llentry *ln;
1831 struct in6_addr nb_addr = nbi->addr; /* make local for safety */
1832
1833 if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
1834 return (error);
1835
1836 IF_AFDATA_RLOCK(ifp);
1837 ln = nd6_lookup(&nb_addr, 0, ifp);
1838 IF_AFDATA_RUNLOCK(ifp);
1839
1840 if (ln == NULL) {
1841 error = EINVAL;
1842 break;
1843 }
1844 nbi->state = ln->ln_state;
1845 nbi->asked = ln->la_asked;
1846 nbi->isrouter = ln->ln_router;
1847 if (ln->la_expire == 0)
1848 nbi->expire = 0;
1849 else
1850 nbi->expire = ln->la_expire + ln->lle_remtime / hz +
1851 (time_second - time_uptime);
1852 LLE_RUNLOCK(ln);
1853 break;
1854 }
1855 case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1856 ndif->ifindex = V_nd6_defifindex;
1857 break;
1858 case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
1859 return (nd6_setdefaultiface(ndif->ifindex));
1860 }
1861 return (error);
1862 }
1863
1864 /*
1865 * Calculates new isRouter value based on provided parameters and
1866 * returns it.
1867 */
1868 static int
nd6_is_router(int type,int code,int is_new,int old_addr,int new_addr,int ln_router)1869 nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
1870 int ln_router)
1871 {
1872
1873 /*
1874 * ICMP6 type dependent behavior.
1875 *
1876 * NS: clear IsRouter if new entry
1877 * RS: clear IsRouter
1878 * RA: set IsRouter if there's lladdr
1879 * redir: clear IsRouter if new entry
1880 *
1881 * RA case, (1):
1882 * The spec says that we must set IsRouter in the following cases:
1883 * - If lladdr exist, set IsRouter. This means (1-5).
1884 * - If it is old entry (!newentry), set IsRouter. This means (7).
1885 * So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
1886 * A quetion arises for (1) case. (1) case has no lladdr in the
1887 * neighbor cache, this is similar to (6).
1888 * This case is rare but we figured that we MUST NOT set IsRouter.
1889 *
1890 * is_new old_addr new_addr NS RS RA redir
1891 * D R
1892 * 0 n n (1) c ? s
1893 * 0 y n (2) c s s
1894 * 0 n y (3) c s s
1895 * 0 y y (4) c s s
1896 * 0 y y (5) c s s
1897 * 1 -- n (6) c c c s
1898 * 1 -- y (7) c c s c s
1899 *
1900 * (c=clear s=set)
1901 */
1902 switch (type & 0xff) {
1903 case ND_NEIGHBOR_SOLICIT:
1904 /*
1905 * New entry must have is_router flag cleared.
1906 */
1907 if (is_new) /* (6-7) */
1908 ln_router = 0;
1909 break;
1910 case ND_REDIRECT:
1911 /*
1912 * If the icmp is a redirect to a better router, always set the
1913 * is_router flag. Otherwise, if the entry is newly created,
1914 * clear the flag. [RFC 2461, sec 8.3]
1915 */
1916 if (code == ND_REDIRECT_ROUTER)
1917 ln_router = 1;
1918 else {
1919 if (is_new) /* (6-7) */
1920 ln_router = 0;
1921 }
1922 break;
1923 case ND_ROUTER_SOLICIT:
1924 /*
1925 * is_router flag must always be cleared.
1926 */
1927 ln_router = 0;
1928 break;
1929 case ND_ROUTER_ADVERT:
1930 /*
1931 * Mark an entry with lladdr as a router.
1932 */
1933 if ((!is_new && (old_addr || new_addr)) || /* (2-5) */
1934 (is_new && new_addr)) { /* (7) */
1935 ln_router = 1;
1936 }
1937 break;
1938 }
1939
1940 return (ln_router);
1941 }
1942
1943 /*
1944 * Create neighbor cache entry and cache link-layer address,
1945 * on reception of inbound ND6 packets. (RS/RA/NS/redirect)
1946 *
1947 * type - ICMP6 type
1948 * code - type dependent information
1949 *
1950 */
1951 void
nd6_cache_lladdr(struct ifnet * ifp,struct in6_addr * from,char * lladdr,int lladdrlen,int type,int code)1952 nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
1953 int lladdrlen, int type, int code)
1954 {
1955 struct llentry *ln = NULL, *ln_tmp;
1956 int is_newentry;
1957 int do_update;
1958 int olladdr;
1959 int llchange;
1960 int flags;
1961 uint16_t router = 0;
1962 struct sockaddr_in6 sin6;
1963 struct mbuf *chain = NULL;
1964 u_char linkhdr[LLE_MAX_LINKHDR];
1965 size_t linkhdrsize;
1966 int lladdr_off;
1967
1968 IF_AFDATA_UNLOCK_ASSERT(ifp);
1969
1970 KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
1971 KASSERT(from != NULL, ("%s: from == NULL", __func__));
1972
1973 /* nothing must be updated for unspecified address */
1974 if (IN6_IS_ADDR_UNSPECIFIED(from))
1975 return;
1976
1977 /*
1978 * Validation about ifp->if_addrlen and lladdrlen must be done in
1979 * the caller.
1980 *
1981 * XXX If the link does not have link-layer adderss, what should
1982 * we do? (ifp->if_addrlen == 0)
1983 * Spec says nothing in sections for RA, RS and NA. There's small
1984 * description on it in NS section (RFC 2461 7.2.3).
1985 */
1986 flags = lladdr ? LLE_EXCLUSIVE : 0;
1987 IF_AFDATA_RLOCK(ifp);
1988 ln = nd6_lookup(from, flags, ifp);
1989 IF_AFDATA_RUNLOCK(ifp);
1990 is_newentry = 0;
1991 if (ln == NULL) {
1992 flags |= LLE_EXCLUSIVE;
1993 ln = nd6_alloc(from, 0, ifp);
1994 if (ln == NULL)
1995 return;
1996
1997 /*
1998 * Since we already know all the data for the new entry,
1999 * fill it before insertion.
2000 */
2001 if (lladdr != NULL) {
2002 linkhdrsize = sizeof(linkhdr);
2003 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
2004 linkhdr, &linkhdrsize, &lladdr_off) != 0)
2005 return;
2006 lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
2007 lladdr_off);
2008 }
2009
2010 IF_AFDATA_WLOCK(ifp);
2011 LLE_WLOCK(ln);
2012 /* Prefer any existing lle over newly-created one */
2013 ln_tmp = nd6_lookup(from, LLE_EXCLUSIVE, ifp);
2014 if (ln_tmp == NULL)
2015 lltable_link_entry(LLTABLE6(ifp), ln);
2016 IF_AFDATA_WUNLOCK(ifp);
2017 if (ln_tmp == NULL) {
2018 /* No existing lle, mark as new entry (6,7) */
2019 is_newentry = 1;
2020 if (lladdr != NULL) { /* (7) */
2021 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2022 EVENTHANDLER_INVOKE(lle_event, ln,
2023 LLENTRY_RESOLVED);
2024 }
2025 } else {
2026 lltable_free_entry(LLTABLE6(ifp), ln);
2027 ln = ln_tmp;
2028 ln_tmp = NULL;
2029 }
2030 }
2031 /* do nothing if static ndp is set */
2032 if ((ln->la_flags & LLE_STATIC)) {
2033 if (flags & LLE_EXCLUSIVE)
2034 LLE_WUNLOCK(ln);
2035 else
2036 LLE_RUNLOCK(ln);
2037 return;
2038 }
2039
2040 olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
2041 if (olladdr && lladdr) {
2042 llchange = bcmp(lladdr, ln->ll_addr,
2043 ifp->if_addrlen);
2044 } else if (!olladdr && lladdr)
2045 llchange = 1;
2046 else
2047 llchange = 0;
2048
2049 /*
2050 * newentry olladdr lladdr llchange (*=record)
2051 * 0 n n -- (1)
2052 * 0 y n -- (2)
2053 * 0 n y y (3) * STALE
2054 * 0 y y n (4) *
2055 * 0 y y y (5) * STALE
2056 * 1 -- n -- (6) NOSTATE(= PASSIVE)
2057 * 1 -- y -- (7) * STALE
2058 */
2059
2060 do_update = 0;
2061 if (is_newentry == 0 && llchange != 0) {
2062 do_update = 1; /* (3,5) */
2063
2064 /*
2065 * Record source link-layer address
2066 * XXX is it dependent to ifp->if_type?
2067 */
2068 linkhdrsize = sizeof(linkhdr);
2069 if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
2070 linkhdr, &linkhdrsize, &lladdr_off) != 0)
2071 return;
2072
2073 if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
2074 lladdr_off) == 0) {
2075 /* Entry was deleted */
2076 return;
2077 }
2078
2079 nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
2080
2081 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2082
2083 if (ln->la_hold != NULL)
2084 nd6_grab_holdchain(ln, &chain, &sin6);
2085 }
2086
2087 /* Calculates new router status */
2088 router = nd6_is_router(type, code, is_newentry, olladdr,
2089 lladdr != NULL ? 1 : 0, ln->ln_router);
2090
2091 ln->ln_router = router;
2092 /* Mark non-router redirects with special flag */
2093 if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
2094 ln->la_flags |= LLE_REDIRECT;
2095
2096 if (flags & LLE_EXCLUSIVE)
2097 LLE_WUNLOCK(ln);
2098 else
2099 LLE_RUNLOCK(ln);
2100
2101 if (chain != NULL)
2102 nd6_flush_holdchain(ifp, chain, &sin6);
2103
2104 /*
2105 * When the link-layer address of a router changes, select the
2106 * best router again. In particular, when the neighbor entry is newly
2107 * created, it might affect the selection policy.
2108 * Question: can we restrict the first condition to the "is_newentry"
2109 * case?
2110 * XXX: when we hear an RA from a new router with the link-layer
2111 * address option, defrouter_select_fib() is called twice, since
2112 * defrtrlist_update called the function as well. However, I believe
2113 * we can compromise the overhead, since it only happens the first
2114 * time.
2115 * XXX: although defrouter_select_fib() should not have a bad effect
2116 * for those are not autoconfigured hosts, we explicitly avoid such
2117 * cases for safety.
2118 */
2119 if ((do_update || is_newentry) && router &&
2120 ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
2121 /*
2122 * guaranteed recursion
2123 */
2124 defrouter_select_fib(ifp->if_fib);
2125 }
2126 }
2127
2128 static void
nd6_slowtimo(void * arg)2129 nd6_slowtimo(void *arg)
2130 {
2131 CURVNET_SET((struct vnet *) arg);
2132 struct nd_ifinfo *nd6if;
2133 struct ifnet *ifp;
2134
2135 callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
2136 nd6_slowtimo, curvnet);
2137 IFNET_RLOCK_NOSLEEP();
2138 CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
2139 if (ifp->if_afdata[AF_INET6] == NULL)
2140 continue;
2141 nd6if = ND_IFINFO(ifp);
2142 if (nd6if->basereachable && /* already initialized */
2143 (nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
2144 /*
2145 * Since reachable time rarely changes by router
2146 * advertisements, we SHOULD insure that a new random
2147 * value gets recomputed at least once every few hours.
2148 * (RFC 2461, 6.3.4)
2149 */
2150 nd6if->recalctm = V_nd6_recalc_reachtm_interval;
2151 nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
2152 }
2153 }
2154 IFNET_RUNLOCK_NOSLEEP();
2155 CURVNET_RESTORE();
2156 }
2157
2158 void
nd6_grab_holdchain(struct llentry * ln,struct mbuf ** chain,struct sockaddr_in6 * sin6)2159 nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
2160 struct sockaddr_in6 *sin6)
2161 {
2162
2163 LLE_WLOCK_ASSERT(ln);
2164
2165 *chain = ln->la_hold;
2166 ln->la_hold = NULL;
2167 lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
2168
2169 if (ln->ln_state == ND6_LLINFO_STALE) {
2170
2171 /*
2172 * The first time we send a packet to a
2173 * neighbor whose entry is STALE, we have
2174 * to change the state to DELAY and a sets
2175 * a timer to expire in DELAY_FIRST_PROBE_TIME
2176 * seconds to ensure do neighbor unreachability
2177 * detection on expiration.
2178 * (RFC 2461 7.3.3)
2179 */
2180 nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
2181 }
2182 }
2183
2184 int
nd6_output_ifp(struct ifnet * ifp,struct ifnet * origifp,struct mbuf * m,struct sockaddr_in6 * dst,struct route * ro)2185 nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
2186 struct sockaddr_in6 *dst, struct route *ro)
2187 {
2188 int error;
2189 int ip6len;
2190 struct ip6_hdr *ip6;
2191 struct m_tag *mtag;
2192
2193 #ifdef MAC
2194 mac_netinet6_nd6_send(ifp, m);
2195 #endif
2196
2197 /*
2198 * If called from nd6_ns_output() (NS), nd6_na_output() (NA),
2199 * icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
2200 * as handled by rtsol and rtadvd), mbufs will be tagged for SeND
2201 * to be diverted to user space. When re-injected into the kernel,
2202 * send_output() will directly dispatch them to the outgoing interface.
2203 */
2204 if (send_sendso_input_hook != NULL) {
2205 mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
2206 if (mtag != NULL) {
2207 ip6 = mtod(m, struct ip6_hdr *);
2208 ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
2209 /* Use the SEND socket */
2210 error = send_sendso_input_hook(m, ifp, SND_OUT,
2211 ip6len);
2212 /* -1 == no app on SEND socket */
2213 if (error == 0 || error != -1)
2214 return (error);
2215 }
2216 }
2217
2218 m_clrprotoflags(m); /* Avoid confusing lower layers. */
2219 IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
2220 mtod(m, struct ip6_hdr *));
2221
2222 if ((ifp->if_flags & IFF_LOOPBACK) == 0)
2223 origifp = ifp;
2224
2225 error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
2226 return (error);
2227 }
2228
2229 /*
2230 * Lookup link headerfor @sa_dst address. Stores found
2231 * data in @desten buffer. Copy of lle ln_flags can be also
2232 * saved in @pflags if @pflags is non-NULL.
2233 *
2234 * If destination LLE does not exists or lle state modification
2235 * is required, call "slow" version.
2236 *
2237 * Return values:
2238 * - 0 on success (address copied to buffer).
2239 * - EWOULDBLOCK (no local error, but address is still unresolved)
2240 * - other errors (alloc failure, etc)
2241 */
2242 int
nd6_resolve(struct ifnet * ifp,int is_gw,struct mbuf * m,const struct sockaddr * sa_dst,u_char * desten,uint32_t * pflags,struct llentry ** plle)2243 nd6_resolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
2244 const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
2245 struct llentry **plle)
2246 {
2247 struct llentry *ln = NULL;
2248 const struct sockaddr_in6 *dst6;
2249
2250 if (pflags != NULL)
2251 *pflags = 0;
2252
2253 dst6 = (const struct sockaddr_in6 *)sa_dst;
2254
2255 /* discard the packet if IPv6 operation is disabled on the interface */
2256 if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
2257 m_freem(m);
2258 return (ENETDOWN); /* better error? */
2259 }
2260
2261 if (m != NULL && m->m_flags & M_MCAST) {
2262 switch (ifp->if_type) {
2263 case IFT_ETHER:
2264 case IFT_L2VLAN:
2265 case IFT_BRIDGE:
2266 ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
2267 desten);
2268 return (0);
2269 default:
2270 m_freem(m);
2271 return (EAFNOSUPPORT);
2272 }
2273 }
2274
2275 IF_AFDATA_RLOCK(ifp);
2276 ln = nd6_lookup(&dst6->sin6_addr, plle ? LLE_EXCLUSIVE : LLE_UNLOCKED,
2277 ifp);
2278 if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
2279 /* Entry found, let's copy lle info */
2280 bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
2281 if (pflags != NULL)
2282 *pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
2283 /* Check if we have feedback request from nd6 timer */
2284 if (ln->r_skip_req != 0) {
2285 LLE_REQ_LOCK(ln);
2286 ln->r_skip_req = 0; /* Notify that entry was used */
2287 ln->lle_hittime = time_uptime;
2288 LLE_REQ_UNLOCK(ln);
2289 }
2290 if (plle) {
2291 LLE_ADDREF(ln);
2292 *plle = ln;
2293 LLE_WUNLOCK(ln);
2294 }
2295 IF_AFDATA_RUNLOCK(ifp);
2296 return (0);
2297 } else if (plle && ln)
2298 LLE_WUNLOCK(ln);
2299 IF_AFDATA_RUNLOCK(ifp);
2300
2301 return (nd6_resolve_slow(ifp, 0, m, dst6, desten, pflags, plle));
2302 }
2303
2304
2305 /*
2306 * Do L2 address resolution for @sa_dst address. Stores found
2307 * address in @desten buffer. Copy of lle ln_flags can be also
2308 * saved in @pflags if @pflags is non-NULL.
2309 *
2310 * Heavy version.
2311 * Function assume that destination LLE does not exist,
2312 * is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
2313 *
2314 * Set noinline to be dtrace-friendly
2315 */
2316 static __noinline int
nd6_resolve_slow(struct ifnet * ifp,int flags,struct mbuf * m,const struct sockaddr_in6 * dst,u_char * desten,uint32_t * pflags,struct llentry ** plle)2317 nd6_resolve_slow(struct ifnet *ifp, int flags, struct mbuf *m,
2318 const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
2319 struct llentry **plle)
2320 {
2321 struct llentry *lle = NULL, *lle_tmp;
2322 struct in6_addr *psrc, src;
2323 int send_ns, ll_len;
2324 char *lladdr;
2325
2326 /*
2327 * Address resolution or Neighbor Unreachability Detection
2328 * for the next hop.
2329 * At this point, the destination of the packet must be a unicast
2330 * or an anycast address(i.e. not a multicast).
2331 */
2332 if (lle == NULL) {
2333 IF_AFDATA_RLOCK(ifp);
2334 lle = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
2335 IF_AFDATA_RUNLOCK(ifp);
2336 if ((lle == NULL) && nd6_is_addr_neighbor(dst, ifp)) {
2337 /*
2338 * Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
2339 * the condition below is not very efficient. But we believe
2340 * it is tolerable, because this should be a rare case.
2341 */
2342 lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
2343 if (lle == NULL) {
2344 char ip6buf[INET6_ADDRSTRLEN];
2345 log(LOG_DEBUG,
2346 "nd6_output: can't allocate llinfo for %s "
2347 "(ln=%p)\n",
2348 ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
2349 m_freem(m);
2350 return (ENOBUFS);
2351 }
2352
2353 IF_AFDATA_WLOCK(ifp);
2354 LLE_WLOCK(lle);
2355 /* Prefer any existing entry over newly-created one */
2356 lle_tmp = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
2357 if (lle_tmp == NULL)
2358 lltable_link_entry(LLTABLE6(ifp), lle);
2359 IF_AFDATA_WUNLOCK(ifp);
2360 if (lle_tmp != NULL) {
2361 lltable_free_entry(LLTABLE6(ifp), lle);
2362 lle = lle_tmp;
2363 lle_tmp = NULL;
2364 }
2365 }
2366 }
2367 if (lle == NULL) {
2368 if (!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
2369 m_freem(m);
2370 return (ENOBUFS);
2371 }
2372
2373 if (m != NULL)
2374 m_freem(m);
2375 return (ENOBUFS);
2376 }
2377
2378 LLE_WLOCK_ASSERT(lle);
2379
2380 /*
2381 * The first time we send a packet to a neighbor whose entry is
2382 * STALE, we have to change the state to DELAY and a sets a timer to
2383 * expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
2384 * neighbor unreachability detection on expiration.
2385 * (RFC 2461 7.3.3)
2386 */
2387 if (lle->ln_state == ND6_LLINFO_STALE)
2388 nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
2389
2390 /*
2391 * If the neighbor cache entry has a state other than INCOMPLETE
2392 * (i.e. its link-layer address is already resolved), just
2393 * send the packet.
2394 */
2395 if (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
2396 if (flags & LLE_ADDRONLY) {
2397 lladdr = lle->ll_addr;
2398 ll_len = ifp->if_addrlen;
2399 } else {
2400 lladdr = lle->r_linkdata;
2401 ll_len = lle->r_hdrlen;
2402 }
2403 bcopy(lladdr, desten, ll_len);
2404 if (pflags != NULL)
2405 *pflags = lle->la_flags;
2406 if (plle) {
2407 LLE_ADDREF(lle);
2408 *plle = lle;
2409 }
2410 LLE_WUNLOCK(lle);
2411 return (0);
2412 }
2413
2414 /*
2415 * There is a neighbor cache entry, but no ethernet address
2416 * response yet. Append this latest packet to the end of the
2417 * packet queue in the mbuf. When it exceeds nd6_maxqueuelen,
2418 * the oldest packet in the queue will be removed.
2419 */
2420
2421 if (lle->la_hold != NULL) {
2422 struct mbuf *m_hold;
2423 int i;
2424
2425 i = 0;
2426 for (m_hold = lle->la_hold; m_hold; m_hold = m_hold->m_nextpkt){
2427 i++;
2428 if (m_hold->m_nextpkt == NULL) {
2429 m_hold->m_nextpkt = m;
2430 break;
2431 }
2432 }
2433 while (i >= V_nd6_maxqueuelen) {
2434 m_hold = lle->la_hold;
2435 lle->la_hold = lle->la_hold->m_nextpkt;
2436 m_freem(m_hold);
2437 i--;
2438 }
2439 } else {
2440 lle->la_hold = m;
2441 }
2442
2443 /*
2444 * If there has been no NS for the neighbor after entering the
2445 * INCOMPLETE state, send the first solicitation.
2446 * Note that for newly-created lle la_asked will be 0,
2447 * so we will transition from ND6_LLINFO_NOSTATE to
2448 * ND6_LLINFO_INCOMPLETE state here.
2449 */
2450 psrc = NULL;
2451 send_ns = 0;
2452 if (lle->la_asked == 0) {
2453 lle->la_asked++;
2454 send_ns = 1;
2455 psrc = nd6_llinfo_get_holdsrc(lle, &src);
2456
2457 nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
2458 }
2459 LLE_WUNLOCK(lle);
2460 if (send_ns != 0)
2461 nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
2462
2463 return (EWOULDBLOCK);
2464 }
2465
2466 /*
2467 * Do L2 address resolution for @sa_dst address. Stores found
2468 * address in @desten buffer. Copy of lle ln_flags can be also
2469 * saved in @pflags if @pflags is non-NULL.
2470 *
2471 * Return values:
2472 * - 0 on success (address copied to buffer).
2473 * - EWOULDBLOCK (no local error, but address is still unresolved)
2474 * - other errors (alloc failure, etc)
2475 */
2476 int
nd6_resolve_addr(struct ifnet * ifp,int flags,const struct sockaddr * dst,char * desten,uint32_t * pflags)2477 nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
2478 char *desten, uint32_t *pflags)
2479 {
2480 int error;
2481
2482 flags |= LLE_ADDRONLY;
2483 error = nd6_resolve_slow(ifp, flags, NULL,
2484 (const struct sockaddr_in6 *)dst, desten, pflags, NULL);
2485 return (error);
2486 }
2487
2488 int
nd6_flush_holdchain(struct ifnet * ifp,struct mbuf * chain,struct sockaddr_in6 * dst)2489 nd6_flush_holdchain(struct ifnet *ifp, struct mbuf *chain,
2490 struct sockaddr_in6 *dst)
2491 {
2492 struct mbuf *m, *m_head;
2493 int error = 0;
2494
2495 m_head = chain;
2496
2497 while (m_head) {
2498 m = m_head;
2499 m_head = m_head->m_nextpkt;
2500 error = nd6_output_ifp(ifp, ifp, m, dst, NULL);
2501 }
2502
2503 /*
2504 * XXX
2505 * note that intermediate errors are blindly ignored
2506 */
2507 return (error);
2508 }
2509
2510 static int
nd6_need_cache(struct ifnet * ifp)2511 nd6_need_cache(struct ifnet *ifp)
2512 {
2513 /*
2514 * XXX: we currently do not make neighbor cache on any interface
2515 * other than Ethernet and GIF.
2516 *
2517 * RFC2893 says:
2518 * - unidirectional tunnels needs no ND
2519 */
2520 switch (ifp->if_type) {
2521 case IFT_ETHER:
2522 case IFT_IEEE1394:
2523 case IFT_L2VLAN:
2524 case IFT_INFINIBAND:
2525 case IFT_BRIDGE:
2526 case IFT_PROPVIRTUAL:
2527 return (1);
2528 default:
2529 return (0);
2530 }
2531 }
2532
2533 /*
2534 * Add pernament ND6 link-layer record for given
2535 * interface address.
2536 *
2537 * Very similar to IPv4 arp_ifinit(), but:
2538 * 1) IPv6 DAD is performed in different place
2539 * 2) It is called by IPv6 protocol stack in contrast to
2540 * arp_ifinit() which is typically called in SIOCSIFADDR
2541 * driver ioctl handler.
2542 *
2543 */
2544 int
nd6_add_ifa_lle(struct in6_ifaddr * ia)2545 nd6_add_ifa_lle(struct in6_ifaddr *ia)
2546 {
2547 struct ifnet *ifp;
2548 struct llentry *ln, *ln_tmp;
2549 struct sockaddr *dst;
2550
2551 ifp = ia->ia_ifa.ifa_ifp;
2552 if (nd6_need_cache(ifp) == 0)
2553 return (0);
2554
2555 ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
2556 dst = (struct sockaddr *)&ia->ia_addr;
2557 ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
2558 if (ln == NULL)
2559 return (ENOBUFS);
2560
2561 IF_AFDATA_WLOCK(ifp);
2562 LLE_WLOCK(ln);
2563 /* Unlink any entry if exists */
2564 ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
2565 if (ln_tmp != NULL)
2566 lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
2567 lltable_link_entry(LLTABLE6(ifp), ln);
2568 IF_AFDATA_WUNLOCK(ifp);
2569
2570 if (ln_tmp != NULL)
2571 EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
2572 EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
2573
2574 LLE_WUNLOCK(ln);
2575 if (ln_tmp != NULL)
2576 llentry_free(ln_tmp);
2577
2578 return (0);
2579 }
2580
2581 /*
2582 * Removes either all lle entries for given @ia, or lle
2583 * corresponding to @ia address.
2584 */
2585 void
nd6_rem_ifa_lle(struct in6_ifaddr * ia,int all)2586 nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
2587 {
2588 struct sockaddr_in6 mask, addr;
2589 struct sockaddr *saddr, *smask;
2590 struct ifnet *ifp;
2591
2592 ifp = ia->ia_ifa.ifa_ifp;
2593 memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
2594 memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
2595 saddr = (struct sockaddr *)&addr;
2596 smask = (struct sockaddr *)&mask;
2597
2598 if (all != 0)
2599 lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
2600 else
2601 lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
2602 }
2603
2604 static void
clear_llinfo_pqueue(struct llentry * ln)2605 clear_llinfo_pqueue(struct llentry *ln)
2606 {
2607 struct mbuf *m_hold, *m_hold_next;
2608
2609 for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
2610 m_hold_next = m_hold->m_nextpkt;
2611 m_freem(m_hold);
2612 }
2613
2614 ln->la_hold = NULL;
2615 }
2616
2617 static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
2618 static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
2619
2620 SYSCTL_DECL(_net_inet6_icmp6);
2621 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
2622 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
2623 NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
2624 "NDP default router list");
2625 SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
2626 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
2627 NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
2628 "NDP prefix list");
2629 SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
2630 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
2631 SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
2632 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
2633
2634 static int
nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)2635 nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
2636 {
2637 struct in6_defrouter d;
2638 struct nd_defrouter *dr;
2639 int error;
2640
2641 if (req->newptr != NULL)
2642 return (EPERM);
2643
2644 error = sysctl_wire_old_buffer(req, 0);
2645 if (error != 0)
2646 return (error);
2647
2648 bzero(&d, sizeof(d));
2649 d.rtaddr.sin6_family = AF_INET6;
2650 d.rtaddr.sin6_len = sizeof(d.rtaddr);
2651
2652 ND6_RLOCK();
2653 TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
2654 d.rtaddr.sin6_addr = dr->rtaddr;
2655 error = sa6_recoverscope(&d.rtaddr);
2656 if (error != 0)
2657 break;
2658 d.flags = dr->raflags;
2659 d.rtlifetime = dr->rtlifetime;
2660 d.expire = dr->expire + (time_second - time_uptime);
2661 d.if_index = dr->ifp->if_index;
2662 error = SYSCTL_OUT(req, &d, sizeof(d));
2663 if (error != 0)
2664 break;
2665 }
2666 ND6_RUNLOCK();
2667 return (error);
2668 }
2669
2670 static int
nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)2671 nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
2672 {
2673 struct in6_prefix p;
2674 struct sockaddr_in6 s6;
2675 struct nd_prefix *pr;
2676 struct nd_pfxrouter *pfr;
2677 time_t maxexpire;
2678 int error;
2679 char ip6buf[INET6_ADDRSTRLEN];
2680
2681 if (req->newptr)
2682 return (EPERM);
2683
2684 error = sysctl_wire_old_buffer(req, 0);
2685 if (error != 0)
2686 return (error);
2687
2688 bzero(&p, sizeof(p));
2689 p.origin = PR_ORIG_RA;
2690 bzero(&s6, sizeof(s6));
2691 s6.sin6_family = AF_INET6;
2692 s6.sin6_len = sizeof(s6);
2693
2694 ND6_RLOCK();
2695 LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
2696 p.prefix = pr->ndpr_prefix;
2697 if (sa6_recoverscope(&p.prefix)) {
2698 log(LOG_ERR, "scope error in prefix list (%s)\n",
2699 ip6_sprintf(ip6buf, &p.prefix.sin6_addr));
2700 /* XXX: press on... */
2701 }
2702 p.raflags = pr->ndpr_raf;
2703 p.prefixlen = pr->ndpr_plen;
2704 p.vltime = pr->ndpr_vltime;
2705 p.pltime = pr->ndpr_pltime;
2706 p.if_index = pr->ndpr_ifp->if_index;
2707 if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
2708 p.expire = 0;
2709 else {
2710 /* XXX: we assume time_t is signed. */
2711 maxexpire = (-1) &
2712 ~((time_t)1 << ((sizeof(maxexpire) * 8) - 1));
2713 if (pr->ndpr_vltime < maxexpire - pr->ndpr_lastupdate)
2714 p.expire = pr->ndpr_lastupdate +
2715 pr->ndpr_vltime +
2716 (time_second - time_uptime);
2717 else
2718 p.expire = maxexpire;
2719 }
2720 p.refcnt = pr->ndpr_addrcnt;
2721 p.flags = pr->ndpr_stateflags;
2722 p.advrtrs = 0;
2723 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
2724 p.advrtrs++;
2725 error = SYSCTL_OUT(req, &p, sizeof(p));
2726 if (error != 0)
2727 break;
2728 LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
2729 s6.sin6_addr = pfr->router->rtaddr;
2730 if (sa6_recoverscope(&s6))
2731 log(LOG_ERR,
2732 "scope error in prefix list (%s)\n",
2733 ip6_sprintf(ip6buf, &pfr->router->rtaddr));
2734 error = SYSCTL_OUT(req, &s6, sizeof(s6));
2735 if (error != 0)
2736 goto out;
2737 }
2738 }
2739 out:
2740 ND6_RUNLOCK();
2741 return (error);
2742 }
2743