1 /*-
2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * $KAME: in6_rmx.c,v 1.11 2001/07/26 06:53:16 jinmei Exp $
30 */
31
32 /*-
33 * Copyright 1994, 1995 Massachusetts Institute of Technology
34 *
35 * Permission to use, copy, modify, and distribute this software and
36 * its documentation for any purpose and without fee is hereby
37 * granted, provided that both the above copyright notice and this
38 * permission notice appear in all copies, that both the above
39 * copyright notice and this permission notice appear in all
40 * supporting documentation, and that the name of M.I.T. not be used
41 * in advertising or publicity pertaining to distribution of the
42 * software without specific, written prior permission. M.I.T. makes
43 * no representations about the suitability of this software for any
44 * purpose. It is provided "as is" without express or implied
45 * warranty.
46 *
47 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
48 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
49 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
50 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
51 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
52 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
53 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
54 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
55 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
56 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
57 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 */
61
62 /*
63 * This code does two things necessary for the enhanced TCP metrics to
64 * function in a useful manner:
65 * 1) It marks all non-host routes as `cloning', thus ensuring that
66 * every actual reference to such a route actually gets turned
67 * into a reference to a host route to the specific destination
68 * requested.
69 * 2) When such routes lose all their references, it arranges for them
70 * to be deleted in some random collection of circumstances, so that
71 * a large quantity of stale routing data is not kept in kernel memory
72 * indefinitely. See in6_rtqtimo() below for the exact mechanism.
73 */
74
75 #include <sys/cdefs.h>
76 __FBSDID("$FreeBSD: releng/8.0/sys/netinet6/in6_rmx.c 196019 2009-08-01 19:26:27Z rwatson $");
77
78 #include <sys/param.h>
79 #include <sys/systm.h>
80 #include <sys/kernel.h>
81 #include <sys/lock.h>
82 #include <sys/sysctl.h>
83 #include <sys/queue.h>
84 #include <sys/socket.h>
85 #include <sys/socketvar.h>
86 #include <sys/mbuf.h>
87 #include <sys/rwlock.h>
88 #include <sys/syslog.h>
89 #include <sys/callout.h>
90
91 #include <net/if.h>
92 #include <net/route.h>
93
94 #include <netinet/in.h>
95 #include <netinet/ip_var.h>
96 #include <netinet/in_var.h>
97
98 #include <netinet/ip6.h>
99 #include <netinet6/ip6_var.h>
100
101 #include <netinet/icmp6.h>
102 #include <netinet6/nd6.h>
103
104 #include <netinet/tcp.h>
105 #include <netinet/tcp_seq.h>
106 #include <netinet/tcp_timer.h>
107 #include <netinet/tcp_var.h>
108
109 extern int in6_inithead(void **head, int off);
110 #ifdef VIMAGE
111 extern int in6_detachhead(void **head, int off);
112 #endif
113
114 #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */
115
116 /*
117 * Do what we need to do when inserting a route.
118 */
119 static struct radix_node *
120 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
121 struct radix_node *treenodes)
122 {
123 struct rtentry *rt = (struct rtentry *)treenodes;
124 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt);
125 struct radix_node *ret;
126
127 RADIX_NODE_HEAD_WLOCK_ASSERT(head);
128 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
129 rt->rt_flags |= RTF_MULTICAST;
130
131 /*
132 * A little bit of help for both IPv6 output and input:
133 * For local addresses, we make sure that RTF_LOCAL is set,
134 * with the thought that this might one day be used to speed up
135 * ip_input().
136 *
137 * We also mark routes to multicast addresses as such, because
138 * it's easy to do and might be useful (but this is much more
139 * dubious since it's so easy to inspect the address). (This
140 * is done above.)
141 *
142 * XXX
143 * should elaborate the code.
144 */
145 if (rt->rt_flags & RTF_HOST) {
146 if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)
147 ->sin6_addr,
148 &sin6->sin6_addr)) {
149 rt->rt_flags |= RTF_LOCAL;
150 }
151 }
152
153 if (!rt->rt_rmx.rmx_mtu && rt->rt_ifp)
154 rt->rt_rmx.rmx_mtu = IN6_LINKMTU(rt->rt_ifp);
155
156 ret = rn_addroute(v_arg, n_arg, head, treenodes);
157 if (ret == NULL) {
158 struct rtentry *rt2;
159 /*
160 * We are trying to add a net route, but can't.
161 * The following case should be allowed, so we'll make a
162 * special check for this:
163 * Two IPv6 addresses with the same prefix is assigned
164 * to a single interrface.
165 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
166 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
167 * In this case, (*1) and (*2) want to add the same
168 * net route entry, 3ffe:0501:: -> if0.
169 * This case should not raise an error.
170 */
171 rt2 = rtalloc1((struct sockaddr *)sin6, 0, RTF_RNH_LOCKED);
172 if (rt2) {
173 if (((rt2->rt_flags & (RTF_HOST|RTF_GATEWAY)) == 0)
174 && rt2->rt_gateway
175 && rt2->rt_gateway->sa_family == AF_LINK
176 && rt2->rt_ifp == rt->rt_ifp) {
177 ret = rt2->rt_nodes;
178 }
179 RTFREE_LOCKED(rt2);
180 }
181 }
182 return (ret);
183 }
184
185 /*
186 * This code is the inverse of in6_clsroute: on first reference, if we
187 * were managing the route, stop doing so and set the expiration timer
188 * back off again.
189 */
190 static struct radix_node *
191 in6_matroute(void *v_arg, struct radix_node_head *head)
192 {
193 struct radix_node *rn = rn_match(v_arg, head);
194 struct rtentry *rt = (struct rtentry *)rn;
195
196 if (rt && rt->rt_refcnt == 0) { /* this is first reference */
197 if (rt->rt_flags & RTPRF_OURS) {
198 rt->rt_flags &= ~RTPRF_OURS;
199 rt->rt_rmx.rmx_expire = 0;
200 }
201 }
202 return rn;
203 }
204
205 SYSCTL_DECL(_net_inet6_ip6);
206
207 static VNET_DEFINE(int, rtq_reallyold6);
208 static VNET_DEFINE(int, rtq_minreallyold6);
209 static VNET_DEFINE(int, rtq_toomany6);
210
211 #define V_rtq_reallyold6 VNET(rtq_reallyold6)
212 #define V_rtq_minreallyold6 VNET(rtq_minreallyold6)
213 #define V_rtq_toomany6 VNET(rtq_toomany6)
214
215 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire, CTLFLAG_RW,
216 &VNET_NAME(rtq_reallyold6) , 0, "");
217
218 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW,
219 &VNET_NAME(rtq_minreallyold6) , 0, "");
220
221 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW,
222 &VNET_NAME(rtq_toomany6) , 0, "");
223
224 struct rtqk_arg {
225 struct radix_node_head *rnh;
226 int mode;
227 int updating;
228 int draining;
229 int killed;
230 int found;
231 time_t nextstop;
232 };
233
234 /*
235 * Get rid of old routes. When draining, this deletes everything, even when
236 * the timeout is not expired yet. When updating, this makes sure that
237 * nothing has a timeout longer than the current value of rtq_reallyold6.
238 */
239 static int
240 in6_rtqkill(struct radix_node *rn, void *rock)
241 {
242 struct rtqk_arg *ap = rock;
243 struct rtentry *rt = (struct rtentry *)rn;
244 int err;
245
246 RADIX_NODE_HEAD_WLOCK_ASSERT(ap->rnh);
247
248 if (rt->rt_flags & RTPRF_OURS) {
249 ap->found++;
250
251 if (ap->draining || rt->rt_rmx.rmx_expire <= time_uptime) {
252 if (rt->rt_refcnt > 0)
253 panic("rtqkill route really not free");
254
255 err = rtrequest(RTM_DELETE,
256 (struct sockaddr *)rt_key(rt),
257 rt->rt_gateway, rt_mask(rt),
258 rt->rt_flags|RTF_RNH_LOCKED, 0);
259 if (err) {
260 log(LOG_WARNING, "in6_rtqkill: error %d", err);
261 } else {
262 ap->killed++;
263 }
264 } else {
265 if (ap->updating
266 && (rt->rt_rmx.rmx_expire - time_uptime
267 > V_rtq_reallyold6)) {
268 rt->rt_rmx.rmx_expire = time_uptime
269 + V_rtq_reallyold6;
270 }
271 ap->nextstop = lmin(ap->nextstop,
272 rt->rt_rmx.rmx_expire);
273 }
274 }
275
276 return 0;
277 }
278
279 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
280 static VNET_DEFINE(int, rtq_timeout6);
281 static VNET_DEFINE(struct callout, rtq_timer6);
282
283 #define V_rtq_timeout6 VNET(rtq_timeout6)
284 #define V_rtq_timer6 VNET(rtq_timer6)
285
286 static void
287 in6_rtqtimo(void *rock)
288 {
289 CURVNET_SET_QUIET((struct vnet *) rock);
290 struct radix_node_head *rnh;
291 struct rtqk_arg arg;
292 struct timeval atv;
293 static time_t last_adjusted_timeout = 0;
294
295 rnh = rt_tables_get_rnh(0, AF_INET6);
296 if (rnh == NULL) {
297 CURVNET_RESTORE();
298 return;
299 }
300 arg.found = arg.killed = 0;
301 arg.rnh = rnh;
302 arg.nextstop = time_uptime + V_rtq_timeout6;
303 arg.draining = arg.updating = 0;
304 RADIX_NODE_HEAD_LOCK(rnh);
305 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
306 RADIX_NODE_HEAD_UNLOCK(rnh);
307
308 /*
309 * Attempt to be somewhat dynamic about this:
310 * If there are ``too many'' routes sitting around taking up space,
311 * then crank down the timeout, and see if we can't make some more
312 * go away. However, we make sure that we will never adjust more
313 * than once in rtq_timeout6 seconds, to keep from cranking down too
314 * hard.
315 */
316 if ((arg.found - arg.killed > V_rtq_toomany6)
317 && (time_uptime - last_adjusted_timeout >= V_rtq_timeout6)
318 && V_rtq_reallyold6 > V_rtq_minreallyold6) {
319 V_rtq_reallyold6 = 2*V_rtq_reallyold6 / 3;
320 if (V_rtq_reallyold6 < V_rtq_minreallyold6) {
321 V_rtq_reallyold6 = V_rtq_minreallyold6;
322 }
323
324 last_adjusted_timeout = time_uptime;
325 #ifdef DIAGNOSTIC
326 log(LOG_DEBUG, "in6_rtqtimo: adjusted rtq_reallyold6 to %d",
327 V_rtq_reallyold6);
328 #endif
329 arg.found = arg.killed = 0;
330 arg.updating = 1;
331 RADIX_NODE_HEAD_LOCK(rnh);
332 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
333 RADIX_NODE_HEAD_UNLOCK(rnh);
334 }
335
336 atv.tv_usec = 0;
337 atv.tv_sec = arg.nextstop - time_uptime;
338 callout_reset(&V_rtq_timer6, tvtohz(&atv), in6_rtqtimo, rock);
339 CURVNET_RESTORE();
340 }
341
342 /*
343 * Age old PMTUs.
344 */
345 struct mtuex_arg {
346 struct radix_node_head *rnh;
347 time_t nextstop;
348 };
349
350 static VNET_DEFINE(struct callout, rtq_mtutimer);
351 #define V_rtq_mtutimer VNET(rtq_mtutimer)
352
353 static int
354 in6_mtuexpire(struct radix_node *rn, void *rock)
355 {
356 struct rtentry *rt = (struct rtentry *)rn;
357 struct mtuex_arg *ap = rock;
358
359 /* sanity */
360 if (!rt)
361 panic("rt == NULL in in6_mtuexpire");
362
363 if (rt->rt_rmx.rmx_expire && !(rt->rt_flags & RTF_PROBEMTU)) {
364 if (rt->rt_rmx.rmx_expire <= time_uptime) {
365 rt->rt_flags |= RTF_PROBEMTU;
366 } else {
367 ap->nextstop = lmin(ap->nextstop,
368 rt->rt_rmx.rmx_expire);
369 }
370 }
371
372 return 0;
373 }
374
375 #define MTUTIMO_DEFAULT (60*1)
376
377 static void
378 in6_mtutimo(void *rock)
379 {
380 CURVNET_SET_QUIET((struct vnet *) rock);
381 struct radix_node_head *rnh;
382 struct mtuex_arg arg;
383 struct timeval atv;
384
385 rnh = rt_tables_get_rnh(0, AF_INET6);
386 if (rnh == NULL) {
387 CURVNET_RESTORE();
388 return;
389 }
390 arg.rnh = rnh;
391 arg.nextstop = time_uptime + MTUTIMO_DEFAULT;
392 RADIX_NODE_HEAD_LOCK(rnh);
393 rnh->rnh_walktree(rnh, in6_mtuexpire, &arg);
394 RADIX_NODE_HEAD_UNLOCK(rnh);
395
396 atv.tv_usec = 0;
397 atv.tv_sec = arg.nextstop - time_uptime;
398 if (atv.tv_sec < 0) {
399 printf("invalid mtu expiration time on routing table\n");
400 arg.nextstop = time_uptime + 30; /* last resort */
401 atv.tv_sec = 30;
402 }
403 callout_reset(&V_rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock);
404 CURVNET_RESTORE();
405 }
406
407 /*
408 * Initialize our routing tree.
409 * XXX MRT When off == 0, we are being called from vfs_export.c
410 * so just set up their table and leave. (we know what the correct
411 * value should be so just use that).. FIX AFTER RELENG_7 is MFC'd
412 * see also comments in in_inithead() vfs_export.c and domain.h
413 */
414 int
415 in6_inithead(void **head, int off)
416 {
417 struct radix_node_head *rnh;
418
419 if (!rn_inithead(head, offsetof(struct sockaddr_in6, sin6_addr) << 3))
420 return 0; /* See above */
421
422 if (off == 0) /* See above */
423 return 1; /* only do the rest for the real thing */
424
425 V_rtq_reallyold6 = 60*60; /* one hour is ``really old'' */
426 V_rtq_minreallyold6 = 10; /* never automatically crank down to less */
427 V_rtq_toomany6 = 128; /* 128 cached routes is ``too many'' */
428 V_rtq_timeout6 = RTQ_TIMEOUT;
429
430 rnh = *head;
431 KASSERT(rnh == rt_tables_get_rnh(0, AF_INET6), ("rnh?"));
432 rnh->rnh_addaddr = in6_addroute;
433 rnh->rnh_matchaddr = in6_matroute;
434 callout_init(&V_rtq_timer6, CALLOUT_MPSAFE);
435 callout_init(&V_rtq_mtutimer, CALLOUT_MPSAFE);
436 in6_rtqtimo(curvnet); /* kick off timeout first time */
437 in6_mtutimo(curvnet); /* kick off timeout first time */
438 return 1;
439 }
440
441 #ifdef VIMAGE
442 int
443 in6_detachhead(void **head, int off)
444 {
445
446 callout_drain(&V_rtq_timer6);
447 callout_drain(&V_rtq_mtutimer);
448 return (1);
449 }
450 #endif
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