1 /* $FreeBSD: src/sys/netinet6/in6_rmx.c,v 1.1.2.4 2004/10/06 02:35:17 suz Exp $ */
2 /* $DragonFly: src/sys/netinet6/in6_rmx.c,v 1.13 2005/06/03 19:56:08 eirikn Exp $ */
3 /* $KAME: in6_rmx.c,v 1.11 2001/07/26 06:53:16 jinmei Exp $ */
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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65 * This code does two things necessary for the enhanced TCP metrics to
66 * function in a useful manner:
67 * 1) It marks all non-host routes as `cloning', thus ensuring that
68 * every actual reference to such a route actually gets turned
69 * into a reference to a host route to the specific destination
71 * 2) When such routes lose all their references, it arranges for them
72 * to be deleted in some random collection of circumstances, so that
73 * a large quantity of stale routing data is not kept in kernel memory
74 * indefinitely. See in6_rtqtimo() below for the exact mechanism.
77 #include <sys/param.h>
78 #include <sys/systm.h>
79 #include <sys/kernel.h>
80 #include <sys/sysctl.h>
81 #include <sys/queue.h>
82 #include <sys/socket.h>
83 #include <sys/socketvar.h>
85 #include <sys/syslog.h>
86 #include <sys/thread2.h>
89 #include <net/route.h>
90 #include <netinet/in.h>
91 #include <netinet/ip_var.h>
92 #include <netinet/in_var.h>
94 #include <netinet/ip6.h>
95 #include <netinet6/ip6_var.h>
97 #include <netinet/icmp6.h>
99 #include <netinet/tcp.h>
100 #include <netinet/tcp_seq.h>
101 #include <netinet/tcp_timer.h>
102 #include <netinet/tcp_var.h>
104 static struct callout in6_rtqtimo_ch;
105 static struct callout in6_mtutimo_ch;
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(char *key, char *mask, 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;
123 * For IPv6, all unicast non-host routes are automatically cloning.
125 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
126 rt->rt_flags |= RTF_MULTICAST;
128 if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) {
129 rt->rt_flags |= RTF_PRCLONING;
133 * A little bit of help for both IPv6 output and input:
134 * For local addresses, we make sure that RTF_LOCAL is set,
135 * with the thought that this might one day be used to speed up
138 * We also mark routes to multicast addresses as such, because
139 * it's easy to do and might be useful (but this is much more
140 * dubious since it's so easy to inspect the address). (This
144 * should elaborate the code.
146 if (rt->rt_flags & RTF_HOST) {
147 if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)
150 rt->rt_flags |= RTF_LOCAL;
154 if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU) &&
156 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
158 ret = rn_addroute(key, mask, head, treenodes);
159 if (ret == NULL && rt->rt_flags & RTF_HOST) {
163 * We are trying to add a host route, but can't.
164 * Find out if it is because of an
165 * ARP entry and delete it if so.
167 rt2 = rtpurelookup((struct sockaddr *)sin6);
170 if (rt2->rt_flags & RTF_LLINFO &&
171 rt2->rt_flags & RTF_HOST &&
173 rt2->rt_gateway->sa_family == AF_LINK) {
174 rtrequest(RTM_DELETE, rt_key(rt2),
175 rt2->rt_gateway, rt_mask(rt2),
176 rt2->rt_flags, NULL);
177 ret = rn_addroute(key, mask, head, treenodes);
180 } else if (ret == NULL && rt->rt_flags & RTF_CLONING) {
184 * We are trying to add a net route, but can't.
185 * The following case should be allowed, so we'll make a
186 * special check for this:
187 * Two IPv6 addresses with the same prefix is assigned
188 * to a single interrface.
189 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
190 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
191 * In this case, (*1) and (*2) want to add the same
192 * net route entry, 3ffe:0501:: -> if0.
193 * This case should not raise an error.
195 rt2 = rtpurelookup((struct sockaddr *)sin6);
197 if ((rt2->rt_flags & (RTF_CLONING|RTF_HOST|RTF_GATEWAY))
200 rt2->rt_gateway->sa_family == AF_LINK &&
201 rt2->rt_ifp == rt->rt_ifp) {
211 * This code is the inverse of in6_clsroute: on first reference, if we
212 * were managing the route, stop doing so and set the expiration timer
215 static struct radix_node *
216 in6_matchroute(char *key, struct radix_node_head *head)
218 struct radix_node *rn = rn_match(key, head);
219 struct rtentry *rt = (struct rtentry *)rn;
221 if (rt != NULL && rt->rt_refcnt == 0) { /* this is first reference */
222 if (rt->rt_flags & RTPRF_OURS) {
223 rt->rt_flags &= ~RTPRF_OURS;
224 rt->rt_rmx.rmx_expire = 0;
230 SYSCTL_DECL(_net_inet6_ip6);
232 static int rtq_reallyold = 60*60;
233 /* one hour is ``really old'' */
234 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire,
235 CTLFLAG_RW, &rtq_reallyold , 0, "");
237 static int rtq_minreallyold = 10;
238 /* never automatically crank down to less */
239 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire,
240 CTLFLAG_RW, &rtq_minreallyold , 0, "");
242 static int rtq_toomany = 128;
243 /* 128 cached routes is ``too many'' */
244 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache,
245 CTLFLAG_RW, &rtq_toomany , 0, "");
249 * On last reference drop, mark the route as belong to us so that it can be
253 in6_clsroute(struct radix_node *rn, struct radix_node_head *head)
255 struct rtentry *rt = (struct rtentry *)rn;
257 if (!(rt->rt_flags & RTF_UP))
258 return; /* prophylactic measures */
260 if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST)
263 if ((rt->rt_flags & (RTF_WASCLONED | RTPRF_OURS)) != RTF_WASCLONED)
267 * As requested by David Greenman:
268 * If rtq_reallyold is 0, just delete the route without
269 * waiting for a timeout cycle to kill it.
271 if (rtq_reallyold != 0) {
272 rt->rt_flags |= RTPRF_OURS;
273 rt->rt_rmx.rmx_expire = time_second + rtq_reallyold;
276 * Remove route from the radix tree, but defer deallocation
277 * until we return to rtfree().
279 rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway, rt_mask(rt),
285 struct radix_node_head *rnh;
295 * Get rid of old routes. When draining, this deletes everything, even when
296 * the timeout is not expired yet. When updating, this makes sure that
297 * nothing has a timeout longer than the current value of rtq_reallyold.
300 in6_rtqkill(struct radix_node *rn, void *rock)
302 struct rtqk_arg *ap = rock;
303 struct rtentry *rt = (struct rtentry *)rn;
306 if (rt->rt_flags & RTPRF_OURS) {
309 if (ap->draining || rt->rt_rmx.rmx_expire <= time_second) {
310 if (rt->rt_refcnt > 0)
311 panic("rtqkill route really not free");
313 err = rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
314 rt_mask(rt), rt->rt_flags, NULL);
316 log(LOG_WARNING, "in6_rtqkill: error %d", err);
321 (rt->rt_rmx.rmx_expire - time_second >
323 rt->rt_rmx.rmx_expire =
324 time_second + rtq_reallyold;
326 ap->nextstop = lmin(ap->nextstop,
327 rt->rt_rmx.rmx_expire);
334 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
335 static int rtq_timeout = RTQ_TIMEOUT;
338 in6_rtqtimo(void *rock)
340 struct radix_node_head *rnh = rock;
343 static time_t last_adjusted_timeout = 0;
345 arg.found = arg.killed = 0;
347 arg.nextstop = time_second + rtq_timeout;
348 arg.draining = arg.updating = 0;
350 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
354 * Attempt to be somewhat dynamic about this:
355 * If there are ``too many'' routes sitting around taking up space,
356 * then crank down the timeout, and see if we can't make some more
357 * go away. However, we make sure that we will never adjust more
358 * than once in rtq_timeout seconds, to keep from cranking down too
361 if ((arg.found - arg.killed > rtq_toomany)
362 && (time_second - last_adjusted_timeout >= rtq_timeout)
363 && rtq_reallyold > rtq_minreallyold) {
364 rtq_reallyold = 2*rtq_reallyold / 3;
365 if (rtq_reallyold < rtq_minreallyold) {
366 rtq_reallyold = rtq_minreallyold;
369 last_adjusted_timeout = time_second;
371 log(LOG_DEBUG, "in6_rtqtimo: adjusted rtq_reallyold to %d",
374 arg.found = arg.killed = 0;
377 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
382 atv.tv_sec = arg.nextstop;
383 callout_reset(&in6_rtqtimo_ch, tvtohz_high(&atv), in6_rtqtimo, rock);
390 struct radix_node_head *rnh;
395 in6_mtuexpire(struct radix_node *rn, void *rock)
397 struct rtentry *rt = (struct rtentry *)rn;
398 struct mtuex_arg *ap = rock;
402 panic("rt == NULL in in6_mtuexpire");
404 if (rt->rt_rmx.rmx_expire && !(rt->rt_flags & RTF_PROBEMTU)) {
405 if (rt->rt_rmx.rmx_expire <= time_second) {
406 rt->rt_flags |= RTF_PROBEMTU;
408 ap->nextstop = lmin(ap->nextstop,
409 rt->rt_rmx.rmx_expire);
416 #define MTUTIMO_DEFAULT (60*1)
419 in6_mtutimo(void *rock)
421 struct radix_node_head *rnh = rock;
422 struct mtuex_arg arg;
426 arg.nextstop = time_second + MTUTIMO_DEFAULT;
428 rnh->rnh_walktree(rnh, in6_mtuexpire, &arg);
432 atv.tv_sec = arg.nextstop;
433 if (atv.tv_sec < time_second) {
434 printf("invalid mtu expiration time on routing table\n");
435 arg.nextstop = time_second + 30; /* last resort */
437 callout_reset(&in6_mtutimo_ch, tvtohz_high(&atv), in6_mtutimo, rock);
444 struct radix_node_head *rnh = rt_tables[AF_INET6];
447 arg.found = arg.killed = 0;
453 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
459 * Initialize our routing tree.
462 in6_inithead(void **head, int off)
464 struct radix_node_head *rnh;
466 if (!rn_inithead(head, off))
469 if (head != (void **)&rt_tables[AF_INET6]) /* BOGUS! */
470 return 1; /* only do this for the real routing table */
473 rnh->rnh_addaddr = in6_addroute;
474 rnh->rnh_matchaddr = in6_matchroute;
475 rnh->rnh_close = in6_clsroute;
476 callout_init(&in6_mtutimo_ch);
477 callout_init(&in6_rtqtimo_ch);
478 in6_rtqtimo(rnh); /* kick off timeout first time */
479 in6_mtutimo(rnh); /* kick off timeout first time */