1 /*
2 * Copyright (c) 2003-2021 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29 /*
30 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 * notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 * notice, this list of conditions and the following disclaimer in the
40 * documentation and/or other materials provided with the distribution.
41 * 3. Neither the name of the project nor the names of its contributors
42 * may be used to endorse or promote products derived from this software
43 * without specific prior written permission.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
46 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
49 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55 * SUCH DAMAGE.
56 */
57
58 /*
59 * Copyright 1994, 1995 Massachusetts Institute of Technology
60 *
61 * Permission to use, copy, modify, and distribute this software and
62 * its documentation for any purpose and without fee is hereby
63 * granted, provided that both the above copyright notice and this
64 * permission notice appear in all copies, that both the above
65 * copyright notice and this permission notice appear in all
66 * supporting documentation, and that the name of M.I.T. not be used
67 * in advertising or publicity pertaining to distribution of the
68 * software without specific, written prior permission. M.I.T. makes
69 * no representations about the suitability of this software for any
70 * purpose. It is provided "as is" without express or implied
71 * warranty.
72 *
73 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
74 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
75 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
76 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
77 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
78 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
79 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
80 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
81 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
82 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
83 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
84 * SUCH DAMAGE.
85 *
86 */
87
88 /*
89 * This code does two things necessary for the enhanced TCP metrics to
90 * function in a useful manner:
91 * 1) It marks all non-host routes as `cloning', thus ensuring that
92 * every actual reference to such a route actually gets turned
93 * into a reference to a host route to the specific destination
94 * requested.
95 * 2) When such routes lose all their references, it arranges for them
96 * to be deleted in some random collection of circumstances, so that
97 * a large quantity of stale routing data is not kept in kernel memory
98 * indefinitely. See in6_rtqtimo() below for the exact mechanism.
99 */
100
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/kernel.h>
104 #include <sys/sysctl.h>
105 #include <kern/queue.h>
106 #include <sys/socket.h>
107 #include <sys/socketvar.h>
108 #include <sys/protosw.h>
109 #include <sys/mbuf.h>
110 #include <sys/syslog.h>
111 #include <sys/mcache.h>
112 #include <kern/locks.h>
113
114 #include <net/if.h>
115 #include <net/route.h>
116 #include <netinet/in.h>
117 #include <netinet/ip_var.h>
118 #include <netinet/in_var.h>
119
120 #include <netinet/ip6.h>
121 #include <netinet6/ip6_var.h>
122
123 #include <netinet/icmp6.h>
124
125 #include <netinet/tcp.h>
126 #include <netinet/tcp_seq.h>
127 #include <netinet/tcp_timer.h>
128 #include <netinet/tcp_var.h>
129
130 #include <net/sockaddr_utils.h>
131
132 extern int tvtohz(struct timeval *);
133
134 static int in6_rtqtimo_run; /* in6_rtqtimo is scheduled to run */
135 static void in6_rtqtimo(void *);
136 static void in6_sched_rtqtimo(struct timeval *);
137
138 static struct radix_node *in6_addroute(void *, void *, struct radix_node_head *,
139 struct radix_node *);
140 static struct radix_node *in6_deleteroute(void *, void *,
141 struct radix_node_head *);
142 static struct radix_node *in6_matroute(void *, struct radix_node_head *);
143 static struct radix_node *in6_matroute_args(void *, struct radix_node_head *,
144 rn_matchf_t *, void *);
145 static void in6_clsroute(struct radix_node *, struct radix_node_head *);
146 static int in6_rtqkill(struct radix_node *, void *);
147
148 /*
149 * Accessed by in6_addroute(), in6_deleteroute() and in6_rtqkill(), during
150 * which the routing lock (rnh_lock) is held and thus protects the variable.
151 */
152 static int in6dynroutes;
153
154 /*
155 * Do what we need to do when inserting a route.
156 */
157 static struct radix_node *
in6_addroute(void * v_arg,void * n_arg,struct radix_node_head * head,struct radix_node * treenodes)158 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
159 struct radix_node *treenodes)
160 {
161 struct rtentry *rt = (struct rtentry *)treenodes;
162 struct sockaddr_in6 *sin6 = SIN6(rt_key(rt));
163 struct radix_node *ret;
164 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
165 uint32_t flags = rt->rt_flags;
166 boolean_t verbose = (rt_verbose > 0);
167
168 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
169 RT_LOCK_ASSERT_HELD(rt);
170
171 if (verbose) {
172 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
173 }
174
175 /*
176 * If this is a dynamic route (which is created via Redirect) and
177 * we already have the maximum acceptable number of such route entries,
178 * reject creating a new one. We could initiate garbage collection to
179 * make available space right now, but the benefit would probably not
180 * be worth the cleaning overhead; we only have to endure a slightly
181 * suboptimal path even without the redirected route.
182 */
183 if ((rt->rt_flags & RTF_DYNAMIC) &&
184 ip6_maxdynroutes >= 0 && in6dynroutes >= ip6_maxdynroutes) {
185 return NULL;
186 }
187
188 /*
189 * For IPv6, all unicast non-host routes are automatically cloning.
190 */
191 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
192 rt->rt_flags |= RTF_MULTICAST;
193 }
194
195 if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) {
196 rt->rt_flags |= RTF_PRCLONING;
197 }
198
199 /*
200 * A little bit of help for both IPv6 output and input:
201 * For local addresses, we make sure that RTF_LOCAL is set,
202 * with the thought that this might one day be used to speed up
203 * ip_input().
204 *
205 * We also mark routes to multicast addresses as such, because
206 * it's easy to do and might be useful (but this is much more
207 * dubious since it's so easy to inspect the address). (This
208 * is done above.)
209 *
210 * XXX
211 * should elaborate the code.
212 */
213 if (rt->rt_flags & RTF_HOST) {
214 IFA_LOCK_SPIN(rt->rt_ifa);
215 if (in6_are_addr_equal_scoped(&satosin6(rt->rt_ifa->ifa_addr)->
216 sin6_addr, &sin6->sin6_addr, satosin6(rt->rt_ifa->ifa_addr)->sin6_scope_id, sin6->sin6_scope_id)) {
217 rt->rt_flags |= RTF_LOCAL;
218 }
219 IFA_UNLOCK(rt->rt_ifa);
220 }
221
222 if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
223 rt->rt_ifp) {
224 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
225 }
226
227 /*
228 * rn_addroute route returns NULL if an exact entry is being attempted
229 * to be added again.
230 */
231 ret = rn_addroute(v_arg, n_arg, head, treenodes);
232 if (ret == NULL && (rt->rt_flags & RTF_HOST)) {
233 struct rtentry *rt2;
234 /*
235 * We are trying to add a host route, but can't.
236 * Find out if it is because of an
237 * ND6 entry and delete it if so.
238 */
239 rt2 = rtalloc1_scoped_locked(SA(sin6), 0,
240 RTF_CLONING | RTF_PRCLONING, sin6_get_ifscope(rt_key(rt)));
241 if (rt2 != NULL) {
242 char dbufc[MAX_IPv6_STR_LEN];
243
244 RT_LOCK(rt2);
245 if (verbose) {
246 rt_str(rt2, dbufc, sizeof(dbufc), NULL, 0);
247 }
248
249 if ((rt2->rt_flags & RTF_LLINFO) &&
250 (rt2->rt_flags & RTF_HOST) &&
251 rt2->rt_gateway != NULL &&
252 rt2->rt_gateway->sa_family == AF_LINK) {
253 if (verbose) {
254 os_log_debug(OS_LOG_DEFAULT, "%s: unable to insert "
255 "route to %s:%s, flags=0x%x, due to "
256 "existing ND6 route %s->%s "
257 "flags=0x%x, attempting to delete\n",
258 __func__, dbuf,
259 (rt->rt_ifp != NULL) ?
260 rt->rt_ifp->if_xname : "",
261 rt->rt_flags,
262 dbufc, (rt2->rt_ifp != NULL) ?
263 rt2->rt_ifp->if_xname : "",
264 rt2->rt_flags);
265 }
266 /*
267 * Safe to drop rt_lock and use rt_key,
268 * rt_gateway, since holding rnh_lock here
269 * prevents another thread from calling
270 * rt_setgate() on this route.
271 */
272 RT_UNLOCK(rt2);
273 (void) rtrequest_locked(RTM_DELETE, rt_key(rt2),
274 rt2->rt_gateway, rt_mask(rt2),
275 rt2->rt_flags, NULL);
276 ret = rn_addroute(v_arg, n_arg, head,
277 treenodes);
278 } else {
279 RT_UNLOCK(rt2);
280 }
281 rtfree_locked(rt2);
282 }
283 } else if (ret == NULL && (rt->rt_flags & RTF_CLONING)) {
284 struct rtentry *rt2;
285 /*
286 * We are trying to add a net route, but can't.
287 * The following case should be allowed, so we'll make a
288 * special check for this:
289 * Two IPv6 addresses with the same prefix is assigned
290 * to a single interrface.
291 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
292 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
293 * In this case, (*1) and (*2) want to add the same
294 * net route entry, 3ffe:0501:: -> if0.
295 * This case should not raise an error.
296 */
297 rt2 = rtalloc1_scoped_locked(SA(sin6), 0,
298 RTF_CLONING | RTF_PRCLONING, sin6_get_ifscope(rt_key(rt)));
299 if (rt2 != NULL) {
300 RT_LOCK(rt2);
301 if ((rt2->rt_flags & (RTF_CLONING | RTF_HOST |
302 RTF_GATEWAY)) == RTF_CLONING &&
303 rt2->rt_gateway &&
304 rt2->rt_gateway->sa_family == AF_LINK &&
305 rt2->rt_ifp == rt->rt_ifp) {
306 ret = rt2->rt_nodes;
307 }
308 RT_UNLOCK(rt2);
309 rtfree_locked(rt2);
310 }
311 }
312
313 if (ret != NULL && (rt->rt_flags & RTF_DYNAMIC)) {
314 in6dynroutes++;
315 }
316
317 if (!verbose) {
318 goto done;
319 }
320
321 if (ret != NULL) {
322 if (flags != rt->rt_flags) {
323 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s inserted, "
324 "oflags=0x%x, flags=0x%x\n", __func__,
325 dbuf, gbuf, (rt->rt_ifp != NULL) ?
326 rt->rt_ifp->if_xname : "", flags,
327 rt->rt_flags);
328 } else {
329 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s inserted, "
330 "flags=0x%x\n", __func__, dbuf, gbuf,
331 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
332 rt->rt_flags);
333 }
334 } else {
335 os_log_debug(OS_LOG_DEFAULT, "%s: unable to insert route to %s->%s->%s, "
336 "flags=0x%x, already exists\n", __func__, dbuf, gbuf,
337 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
338 rt->rt_flags);
339 }
340 done:
341 return ret;
342 }
343
344 static struct radix_node *
in6_deleteroute(void * v_arg,void * netmask_arg,struct radix_node_head * head)345 in6_deleteroute(void *v_arg, void *netmask_arg, struct radix_node_head *head)
346 {
347 struct radix_node *rn;
348
349 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
350
351 rn = rn_delete(v_arg, netmask_arg, head);
352 if (rn != NULL) {
353 struct rtentry *rt = (struct rtentry *)rn;
354
355 RT_LOCK(rt);
356 if (rt->rt_flags & RTF_DYNAMIC) {
357 in6dynroutes--;
358 }
359 if (rt_verbose) {
360 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
361
362 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
363 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s deleted, "
364 "flags=0x%x\n", __func__, dbuf, gbuf,
365 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
366 rt->rt_flags);
367 }
368 RT_UNLOCK(rt);
369 }
370 return rn;
371 }
372
373 /*
374 * Validate (unexpire) an expiring AF_INET6 route.
375 */
376 struct radix_node *
in6_validate(struct radix_node * rn)377 in6_validate(struct radix_node *rn)
378 {
379 struct rtentry *rt = (struct rtentry *)rn;
380
381 RT_LOCK_ASSERT_HELD(rt);
382
383 /* This is first reference? */
384 if (rt->rt_refcnt == 0) {
385 if (rt_verbose > 2) {
386 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
387
388 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
389 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s validated, "
390 "flags=0x%x\n", __func__, dbuf, gbuf,
391 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
392 rt->rt_flags);
393 }
394
395 /*
396 * It's one of ours; unexpire it. If the timer is already
397 * scheduled, let it run later as it won't re-arm itself
398 * if there's nothing to do.
399 */
400 if (rt->rt_flags & RTPRF_OURS) {
401 rt->rt_flags &= ~RTPRF_OURS;
402 rt_setexpire(rt, 0);
403 }
404 }
405 return rn;
406 }
407
408 /*
409 * Similar to in6_matroute_args except without the leaf-matching parameters.
410 */
411 static struct radix_node *
in6_matroute(void * v_arg,struct radix_node_head * head)412 in6_matroute(void *v_arg, struct radix_node_head *head)
413 {
414 return in6_matroute_args(v_arg, head, NULL, NULL);
415 }
416
417 /*
418 * This code is the inverse of in6_clsroute: on first reference, if we
419 * were managing the route, stop doing so and set the expiration timer
420 * back off again.
421 */
422 static struct radix_node *
in6_matroute_args(void * v_arg,struct radix_node_head * head,rn_matchf_t * f,void * w)423 in6_matroute_args(void *v_arg, struct radix_node_head *head,
424 rn_matchf_t *f, void *w)
425 {
426 struct radix_node *rn = rn_match_args(v_arg, head, f, w);
427
428 if (rn != NULL) {
429 RT_LOCK_SPIN((struct rtentry *)rn);
430 in6_validate(rn);
431 RT_UNLOCK((struct rtentry *)rn);
432 }
433 return rn;
434 }
435
436 SYSCTL_DECL(_net_inet6_ip6);
437
438 /* one hour is ``really old'' */
439 static uint32_t rtq_reallyold = 60 * 60;
440 SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire,
441 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_reallyold, 0, "");
442
443 /* never automatically crank down to less */
444 static uint32_t rtq_minreallyold = 10;
445 SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire,
446 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_minreallyold, 0, "");
447
448 /* 128 cached routes is ``too many'' */
449 static uint32_t rtq_toomany = 128;
450 SYSCTL_UINT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache,
451 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_toomany, 0, "");
452
453 /*
454 * On last reference drop, mark the route as belong to us so that it can be
455 * timed out.
456 */
457 static void
in6_clsroute(struct radix_node * rn,struct radix_node_head * head)458 in6_clsroute(struct radix_node *rn, struct radix_node_head *head)
459 {
460 #pragma unused(head)
461 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
462 struct rtentry *rt = (struct rtentry *)rn;
463 boolean_t verbose = (rt_verbose > 1);
464
465 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
466 RT_LOCK_ASSERT_HELD(rt);
467
468 if (!(rt->rt_flags & RTF_UP)) {
469 return; /* prophylactic measures */
470 }
471 if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST) {
472 return;
473 }
474
475 if (rt->rt_flags & RTPRF_OURS) {
476 return;
477 }
478
479 if (!(rt->rt_flags & (RTF_WASCLONED | RTF_DYNAMIC))) {
480 return;
481 }
482
483 if (verbose) {
484 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
485 }
486
487 /*
488 * Delete the route immediately if RTF_DELCLONE is set or
489 * if route caching is disabled (rtq_reallyold set to 0).
490 * Otherwise, let it expire and be deleted by in6_rtqkill().
491 */
492 if ((rt->rt_flags & RTF_DELCLONE) || rtq_reallyold == 0) {
493 int err;
494
495 if (verbose) {
496 os_log_debug(OS_LOG_DEFAULT, "%s: deleting route to %s->%s->%s, "
497 "flags=0x%x\n", __func__, dbuf, gbuf,
498 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
499 rt->rt_flags);
500 }
501 /*
502 * Delete the route from the radix tree but since we are
503 * called when the route's reference count is 0, don't
504 * deallocate it until we return from this routine by
505 * telling rtrequest that we're interested in it.
506 * Safe to drop rt_lock and use rt_key, rt_gateway,
507 * since holding rnh_lock here prevents another thread
508 * from calling rt_setgate() on this route.
509 */
510 RT_UNLOCK(rt);
511 err = rtrequest_locked(RTM_DELETE, rt_key(rt),
512 rt->rt_gateway, rt_mask(rt), rt->rt_flags, &rt);
513 if (err == 0) {
514 /* Now let the caller free it */
515 RT_LOCK(rt);
516 RT_REMREF_LOCKED(rt);
517 } else {
518 RT_LOCK(rt);
519 if (!verbose) {
520 rt_str(rt, dbuf, sizeof(dbuf),
521 gbuf, sizeof(gbuf));
522 }
523 os_log_error(OS_LOG_DEFAULT, "%s: error deleting route to "
524 "%s->%s->%s, flags=0x%x, err=%d\n", __func__,
525 dbuf, gbuf, (rt->rt_ifp != NULL) ?
526 rt->rt_ifp->if_xname : "", rt->rt_flags,
527 err);
528 }
529 } else {
530 uint64_t timenow;
531
532 timenow = net_uptime();
533 rt->rt_flags |= RTPRF_OURS;
534 rt_setexpire(rt, timenow + rtq_reallyold);
535
536 if (verbose) {
537 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s invalidated, "
538 "flags=0x%x, expire=T+%u\n", __func__, dbuf, gbuf,
539 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
540 rt->rt_flags, rt->rt_expire - timenow);
541 }
542
543 /* We have at least one entry; arm the timer if not already */
544 in6_sched_rtqtimo(NULL);
545 }
546 }
547
548 struct rtqk_arg {
549 struct radix_node_head *rnh;
550 int updating;
551 int draining;
552 uint32_t killed;
553 uint32_t found;
554 uint64_t nextstop;
555 };
556
557 /*
558 * Get rid of old routes. When draining, this deletes everything, even when
559 * the timeout is not expired yet. This also applies if the route is dynamic
560 * and there are sufficiently large number of such routes (more than a half of
561 * maximum). When updating, this makes sure that nothing has a timeout longer
562 * than the current value of rtq_reallyold.
563 */
564 static int
in6_rtqkill(struct radix_node * rn,void * rock)565 in6_rtqkill(struct radix_node *rn, void *rock)
566 {
567 struct rtqk_arg *ap = rock;
568 struct rtentry *rt = (struct rtentry *)rn;
569 boolean_t verbose = (rt_verbose > 1);
570 uint64_t timenow;
571 int err;
572
573 timenow = net_uptime();
574 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
575
576 RT_LOCK(rt);
577 if (rt->rt_flags & RTPRF_OURS) {
578 char dbuf[MAX_IPv6_STR_LEN], gbuf[MAX_IPv6_STR_LEN];
579
580 if (verbose) {
581 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
582 }
583
584 ap->found++;
585 VERIFY(rt->rt_expire == 0 || rt->rt_rmx.rmx_expire != 0);
586 VERIFY(rt->rt_expire != 0 || rt->rt_rmx.rmx_expire == 0);
587 if (ap->draining || rt->rt_expire <= timenow ||
588 ((rt->rt_flags & RTF_DYNAMIC) && ip6_maxdynroutes >= 0 &&
589 in6dynroutes > ip6_maxdynroutes / 2)) {
590 if (rt->rt_refcnt > 0) {
591 panic("%s: route %p marked with RTPRF_OURS "
592 "with non-zero refcnt (%u)", __func__,
593 rt, rt->rt_refcnt);
594 /* NOTREACHED */
595 }
596
597 if (verbose) {
598 os_log_debug(OS_LOG_DEFAULT, "%s: deleting route to "
599 "%s->%s->%s, flags=0x%x, draining=%d\n",
600 __func__, dbuf, gbuf, (rt->rt_ifp != NULL) ?
601 rt->rt_ifp->if_xname : "", rt->rt_flags,
602 ap->draining);
603 }
604 RT_ADDREF_LOCKED(rt); /* for us to free below */
605 /*
606 * Delete this route since we're done with it;
607 * the route may be freed afterwards, so we
608 * can no longer refer to 'rt' upon returning
609 * from rtrequest(). Safe to drop rt_lock and
610 * use rt_key, rt_gateway, since holding rnh_lock
611 * here prevents another thread from calling
612 * rt_setgate() on this route.
613 */
614 RT_UNLOCK(rt);
615 err = rtrequest_locked(RTM_DELETE, rt_key(rt),
616 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
617 if (err != 0) {
618 RT_LOCK(rt);
619 if (!verbose) {
620 rt_str(rt, dbuf, sizeof(dbuf),
621 gbuf, sizeof(gbuf));
622 }
623 os_log_error(OS_LOG_DEFAULT, "%s: error deleting route to "
624 "%s->%s->%s, flags=0x%x, err=%d\n", __func__,
625 dbuf, gbuf, (rt->rt_ifp != NULL) ?
626 rt->rt_ifp->if_xname : "", rt->rt_flags,
627 err);
628 RT_UNLOCK(rt);
629 } else {
630 ap->killed++;
631 }
632 rtfree_locked(rt);
633 } else {
634 uint64_t expire = (rt->rt_expire - timenow);
635
636 if (ap->updating && expire > rtq_reallyold) {
637 rt_setexpire(rt, timenow + rtq_reallyold);
638 if (verbose) {
639 os_log_debug(OS_LOG_DEFAULT, "%s: route to "
640 "%s->%s->%s, flags=0x%x, adjusted "
641 "expire=T+%u (was T+%u)\n",
642 __func__, dbuf, gbuf,
643 (rt->rt_ifp != NULL) ?
644 rt->rt_ifp->if_xname : "",
645 rt->rt_flags,
646 (rt->rt_expire - timenow), expire);
647 }
648 }
649 ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
650 RT_UNLOCK(rt);
651 }
652 } else {
653 RT_UNLOCK(rt);
654 }
655
656 return 0;
657 }
658
659 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
660 static int rtq_timeout = RTQ_TIMEOUT;
661
662 static void
in6_rtqtimo(void * targ)663 in6_rtqtimo(void *targ)
664 {
665 #pragma unused(targ)
666 struct radix_node_head *rnh;
667 struct rtqk_arg arg;
668 struct timeval atv;
669 static uint64_t last_adjusted_timeout = 0;
670 boolean_t verbose = (rt_verbose > 1);
671 uint64_t timenow;
672 uint32_t ours;
673
674 lck_mtx_lock(rnh_lock);
675 rnh = rt_tables[AF_INET6];
676 VERIFY(rnh != NULL);
677
678 /* Get the timestamp after we acquire the lock for better accuracy */
679 timenow = net_uptime();
680 if (verbose) {
681 os_log_debug(OS_LOG_DEFAULT, "%s: initial nextstop is T+%u seconds\n",
682 __func__, rtq_timeout);
683 }
684 bzero(&arg, sizeof(arg));
685 arg.rnh = rnh;
686 arg.nextstop = timenow + rtq_timeout;
687 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
688 if (verbose) {
689 os_log_debug(OS_LOG_DEFAULT, "%s: found %u, killed %u\n", __func__,
690 arg.found, arg.killed);
691 }
692 /*
693 * Attempt to be somewhat dynamic about this:
694 * If there are ``too many'' routes sitting around taking up space,
695 * then crank down the timeout, and see if we can't make some more
696 * go away. However, we make sure that we will never adjust more
697 * than once in rtq_timeout seconds, to keep from cranking down too
698 * hard.
699 */
700 ours = (arg.found - arg.killed);
701 if (ours > rtq_toomany &&
702 ((timenow - last_adjusted_timeout) >= (uint64_t)rtq_timeout) &&
703 rtq_reallyold > rtq_minreallyold) {
704 rtq_reallyold = 2 * rtq_reallyold / 3;
705 if (rtq_reallyold < rtq_minreallyold) {
706 rtq_reallyold = rtq_minreallyold;
707 }
708
709 last_adjusted_timeout = timenow;
710 if (verbose) {
711 os_log_debug(OS_LOG_DEFAULT, "%s: adjusted rtq_reallyold to %d "
712 "seconds\n", __func__, rtq_reallyold);
713 }
714 arg.found = arg.killed = 0;
715 arg.updating = 1;
716 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
717 }
718
719 atv.tv_usec = 0;
720 atv.tv_sec = arg.nextstop - timenow;
721 /* re-arm the timer only if there's work to do */
722 in6_rtqtimo_run = 0;
723 if (ours > 0) {
724 in6_sched_rtqtimo(&atv);
725 } else if (verbose) {
726 os_log_debug(OS_LOG_DEFAULT, "%s: not rescheduling timer\n", __func__);
727 }
728 lck_mtx_unlock(rnh_lock);
729 }
730
731 static void
in6_sched_rtqtimo(struct timeval * atv)732 in6_sched_rtqtimo(struct timeval *atv)
733 {
734 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
735
736 if (!in6_rtqtimo_run) {
737 struct timeval tv;
738
739 if (atv == NULL) {
740 tv.tv_usec = 0;
741 tv.tv_sec = MAX(rtq_timeout / 10, 1);
742 atv = &tv;
743 }
744 if (rt_verbose > 2) {
745 os_log_debug(OS_LOG_DEFAULT, "%s: timer scheduled in "
746 "T+%llus.%lluu\n", __func__,
747 (uint64_t)atv->tv_sec, (uint64_t)atv->tv_usec);
748 }
749 in6_rtqtimo_run = 1;
750 timeout(in6_rtqtimo, NULL, tvtohz(atv));
751 }
752 }
753
754 void
in6_rtqdrain(void)755 in6_rtqdrain(void)
756 {
757 struct radix_node_head *rnh;
758 struct rtqk_arg arg;
759
760 if (rt_verbose > 1) {
761 os_log_debug(OS_LOG_DEFAULT, "%s: draining routes\n", __func__);
762 }
763
764 lck_mtx_lock(rnh_lock);
765 rnh = rt_tables[AF_INET6];
766 VERIFY(rnh != NULL);
767 bzero(&arg, sizeof(arg));
768 arg.rnh = rnh;
769 arg.draining = 1;
770 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
771 lck_mtx_unlock(rnh_lock);
772 }
773
774 /*
775 * Initialize our routing tree.
776 */
777 int
in6_inithead(void ** head,int off)778 in6_inithead(void **head, int off)
779 {
780 struct radix_node_head *rnh;
781
782 /* If called from route_init(), make sure it is exactly once */
783 VERIFY(head != (void **)&rt_tables[AF_INET6] || *head == NULL);
784
785 if (!rn_inithead(head, off)) {
786 return 0;
787 }
788
789 /*
790 * We can get here from nfs_subs.c as well, in which case this
791 * won't be for the real routing table and thus we're done;
792 * this also takes care of the case when we're called more than
793 * once from anywhere but route_init().
794 */
795 if (head != (void **)&rt_tables[AF_INET6]) {
796 return 1; /* only do this for the real routing table */
797 }
798 rnh = *head;
799 rnh->rnh_addaddr = in6_addroute;
800 rnh->rnh_deladdr = in6_deleteroute;
801 rnh->rnh_matchaddr = in6_matroute;
802 rnh->rnh_matchaddr_args = in6_matroute_args;
803 rnh->rnh_close = in6_clsroute;
804 return 1;
805 }
806