2 /* $KAME: in6_rmx.c,v 1.11 2001/07/26 06:53:16 jinmei Exp $ */
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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34 * Copyright 1994, 1995 Massachusetts Institute of Technology
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56 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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64 * This code does two things necessary for the enhanced TCP metrics to
65 * function in a useful manner:
66 * 1) It marks all non-host routes as `cloning', thus ensuring that
67 * every actual reference to such a route actually gets turned
68 * into a reference to a host route to the specific destination
70 * 2) When such routes lose all their references, it arranges for them
71 * to be deleted in some random collection of circumstances, so that
72 * a large quantity of stale routing data is not kept in kernel memory
73 * indefinitely. See in6_rtqtimo() below for the exact mechanism.
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/kernel.h>
79 #include <sys/sysctl.h>
80 #include <sys/queue.h>
81 #include <sys/socket.h>
82 #include <sys/socketvar.h>
84 #include <sys/syslog.h>
85 #include <sys/callout.h>
88 #include <net/route.h>
89 #include <netinet/in.h>
90 #include <netinet/ip_var.h>
91 #include <netinet/in_var.h>
93 #include <netinet/ip6.h>
94 #include <netinet6/ip6_var.h>
96 #include <netinet/icmp6.h>
97 #include <netinet6/nd6.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 extern int in6_inithead __P((void **head, int off));
106 #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */
109 * Do what we need to do when inserting a route.
111 static struct radix_node *
112 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
113 struct radix_node *treenodes)
115 struct rtentry *rt = (struct rtentry *)treenodes;
116 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt);
117 struct radix_node *ret;
119 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
120 rt->rt_flags |= RTF_MULTICAST;
123 * A little bit of help for both IPv6 output and input:
124 * For local addresses, we make sure that RTF_LOCAL is set,
125 * with the thought that this might one day be used to speed up
128 * We also mark routes to multicast addresses as such, because
129 * it's easy to do and might be useful (but this is much more
130 * dubious since it's so easy to inspect the address). (This
134 * should elaborate the code.
136 if (rt->rt_flags & RTF_HOST) {
137 if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)
140 rt->rt_flags |= RTF_LOCAL;
144 if (!rt->rt_rmx.rmx_mtu && rt->rt_ifp)
145 rt->rt_rmx.rmx_mtu = IN6_LINKMTU(rt->rt_ifp);
147 ret = rn_addroute(v_arg, n_arg, head, treenodes);
148 if (ret == NULL && rt->rt_flags & RTF_HOST) {
151 * We are trying to add a host route, but can't.
152 * Find out if it is because of an
153 * ARP entry and delete it if so.
155 rt2 = rtalloc1((struct sockaddr *)sin6, 0, RTF_CLONING);
157 if (rt2->rt_flags & RTF_LLINFO &&
158 rt2->rt_flags & RTF_HOST &&
160 rt2->rt_gateway->sa_family == AF_LINK) {
163 ret = rn_addroute(v_arg, n_arg, head,
168 } else if (ret == NULL && rt->rt_flags & RTF_CLONING) {
171 * We are trying to add a net route, but can't.
172 * The following case should be allowed, so we'll make a
173 * special check for this:
174 * Two IPv6 addresses with the same prefix is assigned
175 * to a single interrface.
176 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
177 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
178 * In this case, (*1) and (*2) want to add the same
179 * net route entry, 3ffe:0501:: -> if0.
180 * This case should not raise an error.
182 rt2 = rtalloc1((struct sockaddr *)sin6, 0, RTF_CLONING);
184 if ((rt2->rt_flags & (RTF_CLONING|RTF_HOST|RTF_GATEWAY))
187 && rt2->rt_gateway->sa_family == AF_LINK
188 && rt2->rt_ifp == rt->rt_ifp) {
198 * This code is the inverse of in6_clsroute: on first reference, if we
199 * were managing the route, stop doing so and set the expiration timer
202 static struct radix_node *
203 in6_matroute(void *v_arg, struct radix_node_head *head)
205 struct radix_node *rn = rn_match(v_arg, head);
206 struct rtentry *rt = (struct rtentry *)rn;
208 if (rt && rt->rt_refcnt == 0) { /* this is first reference */
209 if (rt->rt_flags & RTPRF_OURS) {
210 rt->rt_flags &= ~RTPRF_OURS;
211 rt->rt_rmx.rmx_expire = 0;
217 SYSCTL_DECL(_net_inet6_ip6);
219 static int rtq_reallyold = 60*60;
220 /* one hour is ``really old'' */
221 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire,
222 CTLFLAG_RW, &rtq_reallyold , 0, "");
224 static int rtq_minreallyold = 10;
225 /* never automatically crank down to less */
226 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire,
227 CTLFLAG_RW, &rtq_minreallyold , 0, "");
229 static int rtq_toomany = 128;
230 /* 128 cached routes is ``too many'' */
231 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache,
232 CTLFLAG_RW, &rtq_toomany , 0, "");
236 * On last reference drop, mark the route as belong to us so that it can be
240 in6_clsroute(struct radix_node *rn, struct radix_node_head *head)
242 struct rtentry *rt = (struct rtentry *)rn;
246 if (!(rt->rt_flags & RTF_UP))
247 return; /* prophylactic measures */
249 if ((rt->rt_flags & (RTF_LLINFO | RTF_HOST)) != RTF_HOST)
252 if ((rt->rt_flags & (RTF_WASCLONED | RTPRF_OURS)) != RTF_WASCLONED)
256 * As requested by David Greenman:
257 * If rtq_reallyold is 0, just delete the route without
258 * waiting for a timeout cycle to kill it.
260 if (rtq_reallyold != 0) {
261 rt->rt_flags |= RTPRF_OURS;
262 rt->rt_rmx.rmx_expire = time_uptime + rtq_reallyold;
269 struct radix_node_head *rnh;
279 * Get rid of old routes. When draining, this deletes everything, even when
280 * the timeout is not expired yet. When updating, this makes sure that
281 * nothing has a timeout longer than the current value of rtq_reallyold.
284 in6_rtqkill(struct radix_node *rn, void *rock)
286 struct rtqk_arg *ap = rock;
287 struct rtentry *rt = (struct rtentry *)rn;
290 if (rt->rt_flags & RTPRF_OURS) {
293 if (ap->draining || rt->rt_rmx.rmx_expire <= time_uptime) {
294 if (rt->rt_refcnt > 0)
295 panic("rtqkill route really not free");
297 err = rtrequest(RTM_DELETE,
298 (struct sockaddr *)rt_key(rt),
299 rt->rt_gateway, rt_mask(rt),
302 log(LOG_WARNING, "in6_rtqkill: error %d", err);
308 && (rt->rt_rmx.rmx_expire - time_uptime
310 rt->rt_rmx.rmx_expire = time_uptime
313 ap->nextstop = lmin(ap->nextstop,
314 rt->rt_rmx.rmx_expire);
321 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */
322 static int rtq_timeout = RTQ_TIMEOUT;
323 static struct callout rtq_timer;
326 in6_rtqtimo(void *rock)
328 struct radix_node_head *rnh = rock;
331 static time_t last_adjusted_timeout = 0;
333 arg.found = arg.killed = 0;
335 arg.nextstop = time_uptime + rtq_timeout;
336 arg.draining = arg.updating = 0;
337 RADIX_NODE_HEAD_LOCK(rnh);
338 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
339 RADIX_NODE_HEAD_UNLOCK(rnh);
342 * Attempt to be somewhat dynamic about this:
343 * If there are ``too many'' routes sitting around taking up space,
344 * then crank down the timeout, and see if we can't make some more
345 * go away. However, we make sure that we will never adjust more
346 * than once in rtq_timeout seconds, to keep from cranking down too
349 if ((arg.found - arg.killed > rtq_toomany)
350 && (time_uptime - last_adjusted_timeout >= rtq_timeout)
351 && rtq_reallyold > rtq_minreallyold) {
352 rtq_reallyold = 2*rtq_reallyold / 3;
353 if (rtq_reallyold < rtq_minreallyold) {
354 rtq_reallyold = rtq_minreallyold;
357 last_adjusted_timeout = time_uptime;
359 log(LOG_DEBUG, "in6_rtqtimo: adjusted rtq_reallyold to %d",
362 arg.found = arg.killed = 0;
364 RADIX_NODE_HEAD_LOCK(rnh);
365 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
366 RADIX_NODE_HEAD_UNLOCK(rnh);
370 atv.tv_sec = arg.nextstop - time_uptime;
371 callout_reset(&rtq_timer, tvtohz(&atv), in6_rtqtimo, rock);
378 struct radix_node_head *rnh;
381 static struct callout rtq_mtutimer;
384 in6_mtuexpire(struct radix_node *rn, void *rock)
386 struct rtentry *rt = (struct rtentry *)rn;
387 struct mtuex_arg *ap = rock;
391 panic("rt == NULL in in6_mtuexpire");
393 if (rt->rt_rmx.rmx_expire && !(rt->rt_flags & RTF_PROBEMTU)) {
394 if (rt->rt_rmx.rmx_expire <= time_uptime) {
395 rt->rt_flags |= RTF_PROBEMTU;
397 ap->nextstop = lmin(ap->nextstop,
398 rt->rt_rmx.rmx_expire);
405 #define MTUTIMO_DEFAULT (60*1)
408 in6_mtutimo(void *rock)
410 struct radix_node_head *rnh = rock;
411 struct mtuex_arg arg;
415 arg.nextstop = time_uptime + MTUTIMO_DEFAULT;
416 RADIX_NODE_HEAD_LOCK(rnh);
417 rnh->rnh_walktree(rnh, in6_mtuexpire, &arg);
418 RADIX_NODE_HEAD_UNLOCK(rnh);
421 atv.tv_sec = arg.nextstop - time_uptime;
422 if (atv.tv_sec < 0) {
423 printf("invalid mtu expiration time on routing table\n");
424 arg.nextstop = time_uptime + 30; /* last resort */
427 callout_reset(&rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock);
434 struct radix_node_head *rnh = rt_tables[AF_INET6];
437 arg.found = arg.killed = 0;
442 RADIX_NODE_HEAD_LOCK(rnh);
443 rnh->rnh_walktree(rnh, in6_rtqkill, &arg);
444 RADIX_NODE_HEAD_UNLOCK(rnh);
449 * Initialize our routing tree.
452 in6_inithead(void **head, int off)
454 struct radix_node_head *rnh;
456 if (!rn_inithead(head, off))
459 if (head != (void **)&rt_tables[AF_INET6]) /* BOGUS! */
460 return 1; /* only do this for the real routing table */
463 rnh->rnh_addaddr = in6_addroute;
464 rnh->rnh_matchaddr = in6_matroute;
465 rnh->rnh_close = in6_clsroute;
466 callout_init(&rtq_timer, CALLOUT_MPSAFE);
467 in6_rtqtimo(rnh); /* kick off timeout first time */
468 callout_init(&rtq_mtutimer, CALLOUT_MPSAFE);
469 in6_mtutimo(rnh); /* kick off timeout first time */