1 /*
2 * Copyright (c) 2000-2017 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 * Copyright 1994, 1995 Massachusetts Institute of Technology
30 *
31 * Permission to use, copy, modify, and distribute this software and
32 * its documentation for any purpose and without fee is hereby
33 * granted, provided that both the above copyright notice and this
34 * permission notice appear in all copies, that both the above
35 * copyright notice and this permission notice appear in all
36 * supporting documentation, and that the name of M.I.T. not be used
37 * in advertising or publicity pertaining to distribution of the
38 * software without specific, written prior permission. M.I.T. makes
39 * no representations about the suitability of this software for any
40 * purpose. It is provided "as is" without express or implied
41 * warranty.
42 *
43 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
44 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
45 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
46 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
47 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
48 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
49 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
50 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
51 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
52 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
53 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54 * SUCH DAMAGE.
55 *
56 */
57
58 /*
59 * This code does two things necessary for the enhanced TCP metrics to
60 * function in a useful manner:
61 * 1) It marks all non-host routes as `cloning', thus ensuring that
62 * every actual reference to such a route actually gets turned
63 * into a reference to a host route to the specific destination
64 * requested.
65 * 2) When such routes lose all their references, it arranges for them
66 * to be deleted in some random collection of circumstances, so that
67 * a large quantity of stale routing data is not kept in kernel memory
68 * indefinitely. See in_rtqtimo() below for the exact mechanism.
69 */
70
71 #include <sys/param.h>
72 #include <sys/systm.h>
73 #include <sys/kernel.h>
74 #include <sys/sysctl.h>
75 #include <sys/socket.h>
76 #include <sys/mbuf.h>
77 #include <sys/protosw.h>
78 #include <sys/syslog.h>
79 #include <sys/mcache.h>
80 #include <kern/locks.h>
81
82 #include <net/if.h>
83 #include <net/route.h>
84 #include <netinet/in.h>
85 #include <netinet/in_var.h>
86 #include <netinet/in_arp.h>
87 #include <netinet/ip.h>
88 #include <netinet/ip6.h>
89 #include <netinet6/nd6.h>
90
91 #include <net/sockaddr_utils.h>
92
93 extern int tvtohz(struct timeval *);
94
95 static int in_rtqtimo_run; /* in_rtqtimo is scheduled to run */
96 static void in_rtqtimo(void *);
97 static void in_sched_rtqtimo(struct timeval *);
98
99 static struct radix_node *in_addroute(void *, void *, struct radix_node_head *,
100 struct radix_node *);
101 static struct radix_node *in_deleteroute(void *, void *,
102 struct radix_node_head *);
103 static struct radix_node *in_matroute(void *, struct radix_node_head *);
104 static struct radix_node *in_matroute_args(void *, struct radix_node_head *,
105 rn_matchf_t *f, void *);
106 static void in_clsroute(struct radix_node *, struct radix_node_head *);
107 static int in_rtqkill(struct radix_node *, void *);
108
109 static int in_ifadownkill(struct radix_node *, void *);
110
111 /*
112 * Do what we need to do when inserting a route.
113 */
114 static struct radix_node *
in_addroute(void * v_arg,void * n_arg,struct radix_node_head * head,struct radix_node * treenodes)115 in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
116 struct radix_node *treenodes)
117 {
118 struct rtentry *rt = (struct rtentry *)treenodes;
119 struct sockaddr_in *sin = SIN(rt_key(rt));
120 struct radix_node *ret;
121 char dbuf[MAX_IPv4_STR_LEN], gbuf[MAX_IPv4_STR_LEN];
122 uint32_t flags = rt->rt_flags;
123 boolean_t verbose = (rt_verbose > 0);
124
125 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
126 RT_LOCK_ASSERT_HELD(rt);
127
128 if (verbose) {
129 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
130 }
131
132 /*
133 * For IP, all unicast non-host routes are automatically cloning.
134 */
135 if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr))) {
136 rt->rt_flags |= RTF_MULTICAST;
137 }
138
139 if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) {
140 rt->rt_flags |= RTF_PRCLONING;
141 }
142
143 /*
144 * A little bit of help for both IP output and input:
145 * For host routes, we make sure that RTF_BROADCAST
146 * is set for anything that looks like a broadcast address.
147 * This way, we can avoid an expensive call to in_broadcast()
148 * in ip_output() most of the time (because the route passed
149 * to ip_output() is almost always a host route).
150 *
151 * We also do the same for local addresses, with the thought
152 * that this might one day be used to speed up ip_input().
153 *
154 * We also mark routes to multicast addresses as such, because
155 * it's easy to do and might be useful (but this is much more
156 * dubious since it's so easy to inspect the address). (This
157 * is done above.)
158 */
159 if (rt->rt_flags & RTF_HOST) {
160 if (in_broadcast(sin->sin_addr, rt->rt_ifp)) {
161 rt->rt_flags |= RTF_BROADCAST;
162 } else {
163 /* Become a regular mutex */
164 RT_CONVERT_LOCK(rt);
165 IFA_LOCK_SPIN(rt->rt_ifa);
166 if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr ==
167 sin->sin_addr.s_addr) {
168 rt->rt_flags |= RTF_LOCAL;
169 }
170 IFA_UNLOCK(rt->rt_ifa);
171 }
172 }
173
174 if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
175 rt->rt_ifp) {
176 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
177 if (INTF_ADJUST_MTU_FOR_CLAT46(rt->rt_ifp)) {
178 rt->rt_rmx.rmx_mtu = IN6_LINKMTU(rt->rt_ifp);
179 /* Further adjust the size for CLAT46 expansion */
180 rt->rt_rmx.rmx_mtu -= CLAT46_HDR_EXPANSION_OVERHD;
181 }
182 }
183
184 ret = rn_addroute(v_arg, n_arg, head, treenodes);
185 if (ret == NULL && (rt->rt_flags & RTF_HOST)) {
186 struct rtentry *rt2;
187 /*
188 * We are trying to add a host route, but can't.
189 * Find out if it is because of an
190 * ARP entry and delete it if so.
191 */
192 rt2 = rtalloc1_scoped_locked(rt_key(rt), 0,
193 RTF_CLONING | RTF_PRCLONING, sin_get_ifscope(rt_key(rt)));
194 if (rt2 != NULL) {
195 char dbufc[MAX_IPv4_STR_LEN];
196
197 RT_LOCK(rt2);
198 if (verbose) {
199 rt_str(rt2, dbufc, sizeof(dbufc), NULL, 0);
200 }
201
202 if ((rt2->rt_flags & RTF_LLINFO) &&
203 (rt2->rt_flags & RTF_HOST) &&
204 rt2->rt_gateway != NULL &&
205 rt2->rt_gateway->sa_family == AF_LINK) {
206 if (verbose) {
207 os_log_debug(OS_LOG_DEFAULT, "%s: unable to insert "
208 "route to %s;%s, flags=0x%x, due to "
209 "existing ARP route %s->%s "
210 "flags=0x%x, attempting to delete\n",
211 __func__, dbuf,
212 (rt->rt_ifp != NULL) ?
213 rt->rt_ifp->if_xname : "",
214 rt->rt_flags, dbufc,
215 (rt2->rt_ifp != NULL) ?
216 rt2->rt_ifp->if_xname : "",
217 rt2->rt_flags);
218 }
219 /*
220 * Safe to drop rt_lock and use rt_key,
221 * rt_gateway, since holding rnh_lock here
222 * prevents another thread from calling
223 * rt_setgate() on this route.
224 */
225 RT_UNLOCK(rt2);
226 (void) rtrequest_locked(RTM_DELETE, rt_key(rt2),
227 rt2->rt_gateway, rt_mask(rt2),
228 rt2->rt_flags, NULL);
229 ret = rn_addroute(v_arg, n_arg, head,
230 treenodes);
231 } else {
232 RT_UNLOCK(rt2);
233 }
234 rtfree_locked(rt2);
235 }
236 }
237
238 if (!verbose) {
239 goto done;
240 }
241
242 if (ret != NULL) {
243 if (flags != rt->rt_flags) {
244 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s inserted, "
245 "oflags=0x%x, flags=0x%x\n", __func__,
246 dbuf, gbuf, (rt->rt_ifp != NULL) ?
247 rt->rt_ifp->if_xname : "", flags,
248 rt->rt_flags);
249 } else {
250 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s inserted, "
251 "flags=0x%x\n", __func__, dbuf, gbuf,
252 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
253 rt->rt_flags);
254 }
255 } else {
256 os_log_debug(OS_LOG_DEFAULT, "%s: unable to insert route to %s->%s->%s, "
257 "flags=0x%x, already exists\n", __func__, dbuf, gbuf,
258 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
259 rt->rt_flags);
260 }
261 done:
262 return ret;
263 }
264
265 static struct radix_node *
in_deleteroute(void * v_arg,void * netmask_arg,struct radix_node_head * head)266 in_deleteroute(void *v_arg, void *netmask_arg, struct radix_node_head *head)
267 {
268 struct radix_node *rn;
269
270 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
271
272 rn = rn_delete(v_arg, netmask_arg, head);
273 if (rt_verbose > 0 && rn != NULL) {
274 char dbuf[MAX_IPv4_STR_LEN], gbuf[MAX_IPv4_STR_LEN];
275 struct rtentry *rt = (struct rtentry *)rn;
276
277 RT_LOCK(rt);
278 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
279 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s deleted, "
280 "flags=0x%x\n", __func__, dbuf, gbuf, (rt->rt_ifp != NULL) ?
281 rt->rt_ifp->if_xname : "", rt->rt_flags);
282 RT_UNLOCK(rt);
283 }
284 return rn;
285 }
286
287 /*
288 * Validate (unexpire) an expiring AF_INET route.
289 */
290 struct radix_node *
in_validate(struct radix_node * rn)291 in_validate(struct radix_node *rn)
292 {
293 struct rtentry *rt = (struct rtentry *)rn;
294
295 RT_LOCK_ASSERT_HELD(rt);
296
297 /* This is first reference? */
298 if (rt->rt_refcnt == 0) {
299 if (rt_verbose > 2) {
300 char dbuf[MAX_IPv4_STR_LEN], gbuf[MAX_IPv4_STR_LEN];
301
302 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
303 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s validated, "
304 "flags=0x%x\n", __func__, dbuf, gbuf,
305 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
306 rt->rt_flags);
307 }
308
309 /*
310 * It's one of ours; unexpire it. If the timer is already
311 * scheduled, let it run later as it won't re-arm itself
312 * if there's nothing to do.
313 */
314 if (rt->rt_flags & RTPRF_OURS) {
315 rt->rt_flags &= ~RTPRF_OURS;
316 rt_setexpire(rt, 0);
317 }
318 }
319 return rn;
320 }
321
322 /*
323 * Similar to in_matroute_args except without the leaf-matching parameters.
324 */
325 static struct radix_node *
in_matroute(void * v_arg,struct radix_node_head * head)326 in_matroute(void *v_arg, struct radix_node_head *head)
327 {
328 return in_matroute_args(v_arg, head, NULL, NULL);
329 }
330
331 /*
332 * This code is the inverse of in_clsroute: on first reference, if we
333 * were managing the route, stop doing so and set the expiration timer
334 * back off again.
335 */
336 static struct radix_node *
in_matroute_args(void * v_arg,struct radix_node_head * head,rn_matchf_t * f,void * w)337 in_matroute_args(void *v_arg, struct radix_node_head *head,
338 rn_matchf_t *f, void *w)
339 {
340 struct radix_node *rn = rn_match_args(v_arg, head, f, w);
341
342 if (rn != NULL) {
343 RT_LOCK_SPIN((struct rtentry *)rn);
344 in_validate(rn);
345 RT_UNLOCK((struct rtentry *)rn);
346 }
347 return rn;
348 }
349
350 /* one hour is ``really old'' */
351 static uint32_t rtq_reallyold = 60 * 60;
352 SYSCTL_UINT(_net_inet_ip, IPCTL_RTEXPIRE, rtexpire,
353 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_reallyold, 0,
354 "Default expiration time on dynamically learned routes");
355
356 /* never automatically crank down to less */
357 static uint32_t rtq_minreallyold = 10;
358 SYSCTL_UINT(_net_inet_ip, IPCTL_RTMINEXPIRE, rtminexpire,
359 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_minreallyold, 0,
360 "Minimum time to attempt to hold onto dynamically learned routes");
361
362 /* 128 cached routes is ``too many'' */
363 static uint32_t rtq_toomany = 128;
364 SYSCTL_UINT(_net_inet_ip, IPCTL_RTMAXCACHE, rtmaxcache,
365 CTLFLAG_RW | CTLFLAG_LOCKED, &rtq_toomany, 0,
366 "Upper limit on dynamically learned routes");
367
368 /*
369 * On last reference drop, mark the route as belong to us so that it can be
370 * timed out.
371 */
372 static void
in_clsroute(struct radix_node * rn,struct radix_node_head * head)373 in_clsroute(struct radix_node *rn, struct radix_node_head *head)
374 {
375 #pragma unused(head)
376 char dbuf[MAX_IPv4_STR_LEN], gbuf[MAX_IPv4_STR_LEN];
377 struct rtentry *rt = (struct rtentry *)rn;
378 boolean_t verbose = (rt_verbose > 1);
379
380 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
381 RT_LOCK_ASSERT_HELD(rt);
382
383 if (!(rt->rt_flags & RTF_UP)) {
384 return; /* prophylactic measures */
385 }
386 if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST) {
387 return;
388 }
389
390 if (rt->rt_flags & RTPRF_OURS) {
391 return;
392 }
393
394 if (!(rt->rt_flags & (RTF_WASCLONED | RTF_DYNAMIC))) {
395 return;
396 }
397
398 if (verbose) {
399 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
400 }
401
402 /*
403 * Delete the route immediately if RTF_DELCLONE is set or
404 * if route caching is disabled (rtq_reallyold set to 0).
405 * Otherwise, let it expire and be deleted by in_rtqkill().
406 */
407 if ((rt->rt_flags & RTF_DELCLONE) || rtq_reallyold == 0) {
408 int err;
409
410 if (verbose) {
411 os_log_debug(OS_LOG_DEFAULT, "%s: deleting route to %s->%s->%s, "
412 "flags=0x%x\n", __func__, dbuf, gbuf,
413 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
414 rt->rt_flags);
415 }
416 /*
417 * Delete the route from the radix tree but since we are
418 * called when the route's reference count is 0, don't
419 * deallocate it until we return from this routine by
420 * telling rtrequest that we're interested in it.
421 * Safe to drop rt_lock and use rt_key, rt_gateway since
422 * holding rnh_lock here prevents another thread from
423 * calling rt_setgate() on this route.
424 */
425 RT_UNLOCK(rt);
426 err = rtrequest_locked(RTM_DELETE, rt_key(rt),
427 rt->rt_gateway, rt_mask(rt), rt->rt_flags, &rt);
428 if (err == 0) {
429 /* Now let the caller free it */
430 RT_LOCK(rt);
431 RT_REMREF_LOCKED(rt);
432 } else {
433 RT_LOCK(rt);
434 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
435 os_log_error(OS_LOG_DEFAULT, "%s: error deleting route to "
436 "%s->%s->%s, flags=0x%x, err=%d\n", __func__,
437 dbuf, gbuf, (rt->rt_ifp != NULL) ?
438 rt->rt_ifp->if_xname : "", rt->rt_flags,
439 err);
440 }
441 } else {
442 uint64_t timenow;
443
444 timenow = net_uptime();
445 rt->rt_flags |= RTPRF_OURS;
446 rt_setexpire(rt, timenow + rtq_reallyold);
447
448 if (rt_verbose > 1) {
449 os_log_debug(OS_LOG_DEFAULT, "%s: route to %s->%s->%s invalidated, "
450 "flags=0x%x, expire=T+%u\n", __func__, dbuf, gbuf,
451 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
452 rt->rt_flags, rt->rt_expire - timenow);
453 }
454
455 /* We have at least one entry; arm the timer if not already */
456 in_sched_rtqtimo(NULL);
457 }
458 }
459
460 struct rtqk_arg {
461 struct radix_node_head *rnh;
462 int updating;
463 int draining;
464 uint32_t killed;
465 uint32_t found;
466 uint64_t nextstop;
467 };
468
469 /*
470 * Get rid of old routes. When draining, this deletes everything, even when
471 * the timeout is not expired yet. When updating, this makes sure that
472 * nothing has a timeout longer than the current value of rtq_reallyold.
473 */
474 static int
in_rtqkill(struct radix_node * rn,void * rock)475 in_rtqkill(struct radix_node *rn, void *rock)
476 {
477 struct rtqk_arg *ap = rock;
478 struct rtentry *rt = (struct rtentry *)rn;
479 boolean_t verbose = (rt_verbose > 1);
480 uint64_t timenow;
481 int err;
482
483 timenow = net_uptime();
484 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
485
486 RT_LOCK(rt);
487 if (rt->rt_flags & RTPRF_OURS) {
488 char dbuf[MAX_IPv4_STR_LEN], gbuf[MAX_IPv4_STR_LEN];
489
490 if (verbose) {
491 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
492 }
493
494 ap->found++;
495 VERIFY(rt->rt_expire == 0 || rt->rt_rmx.rmx_expire != 0);
496 VERIFY(rt->rt_expire != 0 || rt->rt_rmx.rmx_expire == 0);
497 if (ap->draining || rt->rt_expire <= timenow) {
498 if (rt->rt_refcnt > 0) {
499 panic("%s: route %p marked with RTPRF_OURS "
500 "with non-zero refcnt (%u)", __func__,
501 rt, rt->rt_refcnt);
502 /* NOTREACHED */
503 }
504
505 if (verbose) {
506 os_log_debug(OS_LOG_DEFAULT, "%s: deleting route to "
507 "%s->%s->%s, flags=0x%x, draining=%d\n",
508 __func__, dbuf, gbuf, (rt->rt_ifp != NULL) ?
509 rt->rt_ifp->if_xname : "", rt->rt_flags,
510 ap->draining);
511 }
512 RT_ADDREF_LOCKED(rt); /* for us to free below */
513 /*
514 * Delete this route since we're done with it;
515 * the route may be freed afterwards, so we
516 * can no longer refer to 'rt' upon returning
517 * from rtrequest(). Safe to drop rt_lock and
518 * use rt_key, rt_gateway since holding rnh_lock
519 * here prevents another thread from calling
520 * rt_setgate() on this route.
521 */
522 RT_UNLOCK(rt);
523 err = rtrequest_locked(RTM_DELETE, rt_key(rt),
524 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
525 if (err != 0) {
526 RT_LOCK(rt);
527 if (!verbose) {
528 rt_str(rt, dbuf, sizeof(dbuf),
529 gbuf, sizeof(gbuf));
530 }
531 os_log_error(OS_LOG_DEFAULT, "%s: error deleting route to "
532 "%s->%s->%s, flags=0x%x, err=%d\n", __func__,
533 dbuf, gbuf, (rt->rt_ifp != NULL) ?
534 rt->rt_ifp->if_xname : "", rt->rt_flags,
535 err);
536 RT_UNLOCK(rt);
537 } else {
538 ap->killed++;
539 }
540 rtfree_locked(rt);
541 } else {
542 uint64_t expire = (rt->rt_expire - timenow);
543
544 if (ap->updating && expire > rtq_reallyold) {
545 rt_setexpire(rt, timenow + rtq_reallyold);
546 if (verbose) {
547 os_log_debug(OS_LOG_DEFAULT, "%s: route to "
548 "%s->%s->%s, flags=0x%x, adjusted "
549 "expire=T+%u (was T+%u)\n",
550 __func__, dbuf, gbuf,
551 (rt->rt_ifp != NULL) ?
552 rt->rt_ifp->if_xname : "",
553 rt->rt_flags,
554 (rt->rt_expire - timenow), expire);
555 }
556 }
557 ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
558 RT_UNLOCK(rt);
559 }
560 } else {
561 RT_UNLOCK(rt);
562 }
563
564 return 0;
565 }
566
567 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
568 static int rtq_timeout = RTQ_TIMEOUT;
569
570 static void
in_rtqtimo(void * targ)571 in_rtqtimo(void *targ)
572 {
573 #pragma unused(targ)
574 struct radix_node_head *rnh;
575 struct rtqk_arg arg;
576 struct timeval atv;
577 static uint64_t last_adjusted_timeout = 0;
578 boolean_t verbose = (rt_verbose > 1);
579 uint64_t timenow;
580 uint32_t ours;
581
582 lck_mtx_lock(rnh_lock);
583 rnh = rt_tables[AF_INET];
584 VERIFY(rnh != NULL);
585
586 /* Get the timestamp after we acquire the lock for better accuracy */
587 timenow = net_uptime();
588 if (verbose) {
589 os_log_debug(OS_LOG_DEFAULT, "%s: initial nextstop is T+%u seconds\n",
590 __func__, rtq_timeout);
591 }
592 bzero(&arg, sizeof(arg));
593 arg.rnh = rnh;
594 arg.nextstop = timenow + rtq_timeout;
595 rnh->rnh_walktree(rnh, in_rtqkill, &arg);
596 if (verbose) {
597 os_log_debug(OS_LOG_DEFAULT, "%s: found %u, killed %u\n", __func__,
598 arg.found, arg.killed);
599 }
600 /*
601 * Attempt to be somewhat dynamic about this:
602 * If there are ``too many'' routes sitting around taking up space,
603 * then crank down the timeout, and see if we can't make some more
604 * go away. However, we make sure that we will never adjust more
605 * than once in rtq_timeout seconds, to keep from cranking down too
606 * hard.
607 */
608 ours = (arg.found - arg.killed);
609 if (ours > rtq_toomany &&
610 ((timenow - last_adjusted_timeout) >= (uint64_t)rtq_timeout) &&
611 rtq_reallyold > rtq_minreallyold) {
612 rtq_reallyold = 2 * rtq_reallyold / 3;
613 if (rtq_reallyold < rtq_minreallyold) {
614 rtq_reallyold = rtq_minreallyold;
615 }
616
617 last_adjusted_timeout = timenow;
618 if (verbose) {
619 os_log_debug(OS_LOG_DEFAULT, "%s: adjusted rtq_reallyold to %d "
620 "seconds\n", __func__, rtq_reallyold);
621 }
622 arg.found = arg.killed = 0;
623 arg.updating = 1;
624 rnh->rnh_walktree(rnh, in_rtqkill, &arg);
625 }
626
627 atv.tv_usec = 0;
628 atv.tv_sec = arg.nextstop - timenow;
629 /* re-arm the timer only if there's work to do */
630 in_rtqtimo_run = 0;
631 if (ours > 0) {
632 in_sched_rtqtimo(&atv);
633 } else if (verbose) {
634 os_log_debug(OS_LOG_DEFAULT, "%s: not rescheduling timer\n", __func__);
635 }
636 lck_mtx_unlock(rnh_lock);
637 }
638
639 static void
in_sched_rtqtimo(struct timeval * atv)640 in_sched_rtqtimo(struct timeval *atv)
641 {
642 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
643
644 if (!in_rtqtimo_run) {
645 struct timeval tv;
646
647 if (atv == NULL) {
648 tv.tv_usec = 0;
649 tv.tv_sec = MAX(rtq_timeout / 10, 1);
650 atv = &tv;
651 }
652 if (rt_verbose > 1) {
653 os_log_debug(OS_LOG_DEFAULT, "%s: timer scheduled in "
654 "T+%llus.%lluu\n", __func__,
655 (uint64_t)atv->tv_sec, (uint64_t)atv->tv_usec);
656 }
657 in_rtqtimo_run = 1;
658 timeout(in_rtqtimo, NULL, tvtohz(atv));
659 }
660 }
661
662 void
in_rtqdrain(void)663 in_rtqdrain(void)
664 {
665 struct radix_node_head *rnh;
666 struct rtqk_arg arg;
667
668 if (rt_verbose > 1) {
669 os_log_debug(OS_LOG_DEFAULT, "%s: draining routes\n", __func__);
670 }
671
672 lck_mtx_lock(rnh_lock);
673 rnh = rt_tables[AF_INET];
674 VERIFY(rnh != NULL);
675 bzero(&arg, sizeof(arg));
676 arg.rnh = rnh;
677 arg.draining = 1;
678 rnh->rnh_walktree(rnh, in_rtqkill, &arg);
679 lck_mtx_unlock(rnh_lock);
680 }
681
682 /*
683 * Initialize our routing tree.
684 */
685 int
in_inithead(void ** head,int off)686 in_inithead(void **head, int off)
687 {
688 struct radix_node_head *rnh;
689
690 /* If called from route_init(), make sure it is exactly once */
691 VERIFY(head != (void **)&rt_tables[AF_INET] || *head == NULL);
692
693 if (!rn_inithead(head, off)) {
694 return 0;
695 }
696
697 /*
698 * We can get here from nfs_subs.c as well, in which case this
699 * won't be for the real routing table and thus we're done;
700 * this also takes care of the case when we're called more than
701 * once from anywhere but route_init().
702 */
703 if (head != (void **)&rt_tables[AF_INET]) {
704 return 1; /* only do this for the real routing table */
705 }
706 rnh = *head;
707 rnh->rnh_addaddr = in_addroute;
708 rnh->rnh_deladdr = in_deleteroute;
709 rnh->rnh_matchaddr = in_matroute;
710 rnh->rnh_matchaddr_args = in_matroute_args;
711 rnh->rnh_close = in_clsroute;
712 return 1;
713 }
714
715 /*
716 * This zaps old routes when the interface goes down or interface
717 * address is deleted. In the latter case, it deletes static routes
718 * that point to this address. If we don't do this, we may end up
719 * using the old address in the future. The ones we always want to
720 * get rid of are things like ARP entries, since the user might down
721 * the interface, walk over to a completely different network, and
722 * plug back in.
723 */
724 struct in_ifadown_arg {
725 struct radix_node_head *rnh;
726 struct ifaddr *ifa;
727 int del;
728 };
729
730 static int
in_ifadownkill(struct radix_node * rn,void * xap)731 in_ifadownkill(struct radix_node *rn, void *xap)
732 {
733 char dbuf[MAX_IPv4_STR_LEN], gbuf[MAX_IPv4_STR_LEN];
734 struct in_ifadown_arg *ap = xap;
735 struct rtentry *rt = (struct rtentry *)rn;
736 boolean_t verbose = (rt_verbose > 1);
737 int err;
738
739 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
740
741 RT_LOCK(rt);
742 if (rt->rt_ifa == ap->ifa &&
743 (ap->del || !(rt->rt_flags & RTF_STATIC))) {
744 rt_str(rt, dbuf, sizeof(dbuf), gbuf, sizeof(gbuf));
745 if (verbose) {
746 os_log_debug(OS_LOG_DEFAULT, "%s: deleting route to %s->%s->%s, "
747 "flags=0x%x\n", __func__, dbuf, gbuf,
748 (rt->rt_ifp != NULL) ? rt->rt_ifp->if_xname : "",
749 rt->rt_flags);
750 }
751
752 RT_ADDREF_LOCKED(rt); /* for us to free below */
753 /*
754 * We need to disable the automatic prune that happens
755 * in this case in rtrequest() because it will blow
756 * away the pointers that rn_walktree() needs in order
757 * continue our descent. We will end up deleting all
758 * the routes that rtrequest() would have in any case,
759 * so that behavior is not needed there. Safe to drop
760 * rt_lock and use rt_key, rt_gateway, since holding
761 * rnh_lock here prevents another thread from calling
762 * rt_setgate() on this route.
763 */
764 rt->rt_flags &= ~(RTF_CLONING | RTF_PRCLONING);
765 RT_UNLOCK(rt);
766 err = rtrequest_locked(RTM_DELETE, rt_key(rt),
767 rt->rt_gateway, rt_mask(rt), rt->rt_flags, NULL);
768 if (err != 0) {
769 RT_LOCK(rt);
770 if (!verbose) {
771 rt_str(rt, dbuf, sizeof(dbuf),
772 gbuf, sizeof(gbuf));
773 }
774 os_log_error(OS_LOG_DEFAULT, "%s: error deleting route to "
775 "%s->%s->%s, flags=0x%x, err=%d\n", __func__,
776 dbuf, gbuf, (rt->rt_ifp != NULL) ?
777 rt->rt_ifp->if_xname : "", rt->rt_flags,
778 err);
779 RT_UNLOCK(rt);
780 }
781 rtfree_locked(rt);
782 } else {
783 RT_UNLOCK(rt);
784 }
785 return 0;
786 }
787
788 int
in_ifadown(struct ifaddr * ifa,int delete)789 in_ifadown(struct ifaddr *ifa, int delete)
790 {
791 struct in_ifadown_arg arg;
792 struct radix_node_head *rnh;
793
794 LCK_MTX_ASSERT(rnh_lock, LCK_MTX_ASSERT_OWNED);
795
796 /*
797 * Holding rnh_lock here prevents the possibility of
798 * ifa from changing (e.g. in_ifinit), so it is safe
799 * to access its ifa_addr without locking.
800 */
801 if (ifa->ifa_addr->sa_family != AF_INET) {
802 return 1;
803 }
804
805 /* trigger route cache reevaluation */
806 routegenid_inet_update();
807
808 arg.rnh = rnh = rt_tables[AF_INET];
809 arg.ifa = ifa;
810 arg.del = delete;
811 rnh->rnh_walktree(rnh, in_ifadownkill, &arg);
812 IFA_LOCK_SPIN(ifa);
813 ifa->ifa_flags &= ~IFA_ROUTE;
814 IFA_UNLOCK(ifa);
815 return 0;
816 }
817