2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 * $KAME: in6_rmx.c,v 1.11 2001/07/26 06:53:16 jinmei Exp $
33 * Copyright 1994, 1995 Massachusetts Institute of Technology
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
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
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
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.
75 #include <sys/cdefs.h>
76 __FBSDID("$FreeBSD$");
78 #include <sys/param.h>
79 #include <sys/systm.h>
80 #include <sys/kernel.h>
81 #include <sys/sysctl.h>
82 #include <sys/queue.h>
83 #include <sys/socket.h>
84 #include <sys/socketvar.h>
86 #include <sys/syslog.h>
87 #include <sys/callout.h>
88 #include <sys/vimage.h>
91 #include <net/route.h>
92 #include <netinet/in.h>
93 #include <netinet/ip_var.h>
94 #include <netinet/in_var.h>
96 #include <netinet/ip6.h>
97 #include <netinet6/ip6_var.h>
99 #include <netinet/icmp6.h>
100 #include <netinet6/nd6.h>
102 #include <netinet/tcp.h>
103 #include <netinet/tcp_seq.h>
104 #include <netinet/tcp_timer.h>
105 #include <netinet/tcp_var.h>
107 extern int in6_inithead(void **head, int off);
109 #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */
112 * Do what we need to do when inserting a route.
114 static struct radix_node *
115 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
116 struct radix_node *treenodes)
118 struct rtentry *rt = (struct rtentry *)treenodes;
119 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt);
120 struct radix_node *ret;
122 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
123 rt->rt_flags |= RTF_MULTICAST;
126 * A little bit of help for both IPv6 output and input:
127 * For local addresses, we make sure that RTF_LOCAL is set,
128 * with the thought that this might one day be used to speed up
131 * We also mark routes to multicast addresses as such, because
132 * it's easy to do and might be useful (but this is much more
133 * dubious since it's so easy to inspect the address). (This
137 * should elaborate the code.
139 if (rt->rt_flags & RTF_HOST) {
140 if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)
143 rt->rt_flags |= RTF_LOCAL;
147 if (!rt->rt_rmx.rmx_mtu && rt->rt_ifp)
148 rt->rt_rmx.rmx_mtu = IN6_LINKMTU(rt->rt_ifp);
150 ret = rn_addroute(v_arg, n_arg, head, treenodes);
151 if (ret == NULL && rt->rt_flags & RTF_HOST) {
154 * We are trying to add a host route, but can't.
155 * Find out if it is because of an
156 * ARP entry and delete it if so.
158 rt2 = rtalloc1((struct sockaddr *)sin6, 0, RTF_CLONING);
160 if (rt2->rt_flags & RTF_LLINFO &&
161 rt2->rt_flags & RTF_HOST &&
163 rt2->rt_gateway->sa_family == AF_LINK) {
166 ret = rn_addroute(v_arg, n_arg, head,
171 } else if (ret == NULL && rt->rt_flags & RTF_CLONING) {
174 * We are trying to add a net route, but can't.
175 * The following case should be allowed, so we'll make a
176 * special check for this:
177 * Two IPv6 addresses with the same prefix is assigned
178 * to a single interrface.
179 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
180 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
181 * In this case, (*1) and (*2) want to add the same
182 * net route entry, 3ffe:0501:: -> if0.
183 * This case should not raise an error.
185 rt2 = rtalloc1((struct sockaddr *)sin6, 0, RTF_CLONING);
187 if ((rt2->rt_flags & (RTF_CLONING|RTF_HOST|RTF_GATEWAY))
190 && rt2->rt_gateway->sa_family == AF_LINK
191 && rt2->rt_ifp == rt->rt_ifp) {
201 * This code is the inverse of in6_clsroute: on first reference, if we
202 * were managing the route, stop doing so and set the expiration timer
205 static struct radix_node *
206 in6_matroute(void *v_arg, struct radix_node_head *head)
208 struct radix_node *rn = rn_match(v_arg, head);
209 struct rtentry *rt = (struct rtentry *)rn;
211 if (rt && rt->rt_refcnt == 0) { /* this is first reference */
212 if (rt->rt_flags & RTPRF_OURS) {
213 rt->rt_flags &= ~RTPRF_OURS;
214 rt->rt_rmx.rmx_expire = 0;
220 SYSCTL_DECL(_net_inet6_ip6);
222 static int rtq_reallyold6 = 60*60;
223 /* one hour is ``really old'' */
224 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire,
225 CTLFLAG_RW, &rtq_reallyold6 , 0, "");
227 static int rtq_minreallyold6 = 10;
228 /* never automatically crank down to less */
229 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire,
230 CTLFLAG_RW, &rtq_minreallyold6 , 0, "");
232 static int rtq_toomany6 = 128;
233 /* 128 cached routes is ``too many'' */
234 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache,
235 CTLFLAG_RW, &rtq_toomany6 , 0, "");
239 * On last reference drop, mark the route as belong to us so that it can be
243 in6_clsroute(struct radix_node *rn, struct radix_node_head *head)
245 INIT_VNET_INET6(curvnet);
246 struct rtentry *rt = (struct rtentry *)rn;
250 if (!(rt->rt_flags & RTF_UP))
251 return; /* prophylactic measures */
253 if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST)
256 if ((rt->rt_flags & (RTF_WASCLONED | RTPRF_OURS)) != RTF_WASCLONED)
260 * As requested by David Greenman:
261 * If rtq_reallyold6 is 0, just delete the route without
262 * waiting for a timeout cycle to kill it.
264 if (V_rtq_reallyold6 != 0) {
265 rt->rt_flags |= RTPRF_OURS;
266 rt->rt_rmx.rmx_expire = time_uptime + V_rtq_reallyold6;
273 struct radix_node_head *rnh;
283 * Get rid of old routes. When draining, this deletes everything, even when
284 * the timeout is not expired yet. When updating, this makes sure that
285 * nothing has a timeout longer than the current value of rtq_reallyold6.
288 in6_rtqkill(struct radix_node *rn, void *rock)
290 INIT_VNET_INET6(curvnet);
291 struct rtqk_arg *ap = rock;
292 struct rtentry *rt = (struct rtentry *)rn;
295 if (rt->rt_flags & RTPRF_OURS) {
298 if (ap->draining || rt->rt_rmx.rmx_expire <= time_uptime) {
299 if (rt->rt_refcnt > 0)
300 panic("rtqkill route really not free");
302 err = rtrequest(RTM_DELETE,
303 (struct sockaddr *)rt_key(rt),
304 rt->rt_gateway, rt_mask(rt),
307 log(LOG_WARNING, "in6_rtqkill: error %d", err);
313 && (rt->rt_rmx.rmx_expire - time_uptime
314 > V_rtq_reallyold6)) {
315 rt->rt_rmx.rmx_expire = time_uptime
318 ap->nextstop = lmin(ap->nextstop,
319 rt->rt_rmx.rmx_expire);
326 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
327 static int rtq_timeout6 = RTQ_TIMEOUT;
328 static struct callout rtq_timer6;
331 in6_rtqtimo(void *rock)
333 CURVNET_SET_QUIET((struct vnet *) rock);
334 INIT_VNET_NET((struct vnet *) rock);
335 INIT_VNET_INET6((struct vnet *) rock);
336 struct radix_node_head *rnh = rock;
339 static time_t last_adjusted_timeout = 0;
341 arg.found = arg.killed = 0;
343 arg.nextstop = time_uptime + V_rtq_timeout6;
344 arg.draining = arg.updating = 0;
345 RADIX_NODE_HEAD_LOCK(rnh);
346 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
347 RADIX_NODE_HEAD_UNLOCK(rnh);
350 * Attempt to be somewhat dynamic about this:
351 * If there are ``too many'' routes sitting around taking up space,
352 * then crank down the timeout, and see if we can't make some more
353 * go away. However, we make sure that we will never adjust more
354 * than once in rtq_timeout6 seconds, to keep from cranking down too
357 if ((arg.found - arg.killed > V_rtq_toomany6)
358 && (time_uptime - last_adjusted_timeout >= V_rtq_timeout6)
359 && V_rtq_reallyold6 > V_rtq_minreallyold6) {
360 V_rtq_reallyold6 = 2*V_rtq_reallyold6 / 3;
361 if (V_rtq_reallyold6 < V_rtq_minreallyold6) {
362 V_rtq_reallyold6 = V_rtq_minreallyold6;
365 last_adjusted_timeout = time_uptime;
367 log(LOG_DEBUG, "in6_rtqtimo: adjusted rtq_reallyold6 to %d",
370 arg.found = arg.killed = 0;
372 RADIX_NODE_HEAD_LOCK(rnh);
373 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
374 RADIX_NODE_HEAD_UNLOCK(rnh);
378 atv.tv_sec = arg.nextstop - time_uptime;
379 callout_reset(&V_rtq_timer6, tvtohz(&atv), in6_rtqtimo, rock);
387 struct radix_node_head *rnh;
390 static struct callout rtq_mtutimer;
393 in6_mtuexpire(struct radix_node *rn, void *rock)
395 struct rtentry *rt = (struct rtentry *)rn;
396 struct mtuex_arg *ap = rock;
400 panic("rt == NULL in in6_mtuexpire");
402 if (rt->rt_rmx.rmx_expire && !(rt->rt_flags & RTF_PROBEMTU)) {
403 if (rt->rt_rmx.rmx_expire <= time_uptime) {
404 rt->rt_flags |= RTF_PROBEMTU;
406 ap->nextstop = lmin(ap->nextstop,
407 rt->rt_rmx.rmx_expire);
414 #define MTUTIMO_DEFAULT (60*1)
417 in6_mtutimo(void *rock)
419 CURVNET_SET_QUIET((struct vnet *) rock);
420 INIT_VNET_NET((struct vnet *) rock);
421 INIT_VNET_INET6((struct vnet *) rock);
422 struct radix_node_head *rnh = rock;
423 struct mtuex_arg arg;
427 arg.nextstop = time_uptime + MTUTIMO_DEFAULT;
428 RADIX_NODE_HEAD_LOCK(rnh);
429 rnh->rnh_walktree(rnh, in6_mtuexpire, &arg);
430 RADIX_NODE_HEAD_UNLOCK(rnh);
433 atv.tv_sec = arg.nextstop - time_uptime;
434 if (atv.tv_sec < 0) {
435 printf("invalid mtu expiration time on routing table\n");
436 arg.nextstop = time_uptime + 30; /* last resort */
439 callout_reset(&V_rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock);
447 INIT_VNET_NET(curvnet);
448 struct radix_node_head *rnh = V_rt_tables[AF_INET6];
451 arg.found = arg.killed = 0;
456 RADIX_NODE_HEAD_LOCK(rnh);
457 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
458 RADIX_NODE_HEAD_UNLOCK(rnh);
463 * Initialize our routing tree.
464 * XXX MRT When off == 0, we are being called from vfs_export.c
465 * so just set up their table and leave. (we know what the correct
466 * value should be so just use that).. FIX AFTER RELENG_7 is MFC'd
467 * see also comments in in_inithead() vfs_export.c and domain.h
470 in6_inithead(void **head, int off)
472 INIT_VNET_INET6(curvnet);
473 struct radix_node_head *rnh;
475 if (!rn_inithead(head, offsetof(struct sockaddr_in6, sin6_addr) << 3))
476 return 0; /* See above */
478 if (off == 0) /* See above */
479 return 1; /* only do the rest for the real thing */
482 rnh->rnh_addaddr = in6_addroute;
483 rnh->rnh_matchaddr = in6_matroute;
484 rnh->rnh_close = in6_clsroute;
485 callout_init(&V_rtq_timer6, CALLOUT_MPSAFE);
486 in6_rtqtimo(rnh); /* kick off timeout first time */
487 callout_init(&V_rtq_mtutimer, CALLOUT_MPSAFE);
488 in6_mtutimo(rnh); /* kick off timeout first time */