1/*-
2 * Copyright 1994, 1995 Massachusetts Institute of Technology
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
7 * permission notice appear in all copies, that both the above
8 * copyright notice and this permission notice appear in all
9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission.  M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose.  It is provided "as is" without express or implied
14 * warranty.
15 *
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD$");
32
33#include <sys/param.h>
34#include <sys/systm.h>
35#include <sys/kernel.h>
36#include <sys/sysctl.h>
37#include <sys/socket.h>
38#include <sys/mbuf.h>
39#include <sys/syslog.h>
40#include <sys/callout.h>
41
42#include <net/if.h>
43#include <net/route.h>
44#include <net/vnet.h>
45
46#include <netinet/in.h>
47#include <netinet/in_var.h>
48#include <netinet/ip.h>
49#include <netinet/ip_icmp.h>
50#include <netinet/ip_var.h>
51
52extern int	in_inithead(void **head, int off);
53#ifdef VIMAGE
54extern int	in_detachhead(void **head, int off);
55#endif
56
57#define RTPRF_OURS		RTF_PROTO3	/* set on routes we manage */
58
59/*
60 * Do what we need to do when inserting a route.
61 */
62static struct radix_node *
63in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
64    struct radix_node *treenodes)
65{
66	struct rtentry *rt = (struct rtentry *)treenodes;
67	struct sockaddr_in *sin = (struct sockaddr_in *)rt_key(rt);
68
69	RADIX_NODE_HEAD_WLOCK_ASSERT(head);
70	/*
71	 * A little bit of help for both IP output and input:
72	 *   For host routes, we make sure that RTF_BROADCAST
73	 *   is set for anything that looks like a broadcast address.
74	 *   This way, we can avoid an expensive call to in_broadcast()
75	 *   in ip_output() most of the time (because the route passed
76	 *   to ip_output() is almost always a host route).
77	 *
78	 *   We also do the same for local addresses, with the thought
79	 *   that this might one day be used to speed up ip_input().
80	 *
81	 * We also mark routes to multicast addresses as such, because
82	 * it's easy to do and might be useful (but this is much more
83	 * dubious since it's so easy to inspect the address).
84	 */
85	if (rt->rt_flags & RTF_HOST) {
86		if (in_broadcast(sin->sin_addr, rt->rt_ifp)) {
87			rt->rt_flags |= RTF_BROADCAST;
88		} else if (satosin(rt->rt_ifa->ifa_addr)->sin_addr.s_addr ==
89		    sin->sin_addr.s_addr) {
90			rt->rt_flags |= RTF_LOCAL;
91		}
92	}
93	if (IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
94		rt->rt_flags |= RTF_MULTICAST;
95
96	if (rt->rt_mtu == 0 && rt->rt_ifp != NULL)
97		rt->rt_mtu = rt->rt_ifp->if_mtu;
98
99	return (rn_addroute(v_arg, n_arg, head, treenodes));
100}
101
102/*
103 * This code is the inverse of in_clsroute: on first reference, if we
104 * were managing the route, stop doing so and set the expiration timer
105 * back off again.
106 */
107static struct radix_node *
108in_matroute(void *v_arg, struct radix_node_head *head)
109{
110	struct radix_node *rn = rn_match(v_arg, head);
111	struct rtentry *rt = (struct rtentry *)rn;
112
113	if (rt) {
114		RT_LOCK(rt);
115		if (rt->rt_flags & RTPRF_OURS) {
116			rt->rt_flags &= ~RTPRF_OURS;
117			rt->rt_expire = 0;
118		}
119		RT_UNLOCK(rt);
120	}
121	return rn;
122}
123
124static VNET_DEFINE(int, rtq_reallyold) = 60*60; /* one hour is "really old" */
125#define	V_rtq_reallyold		VNET(rtq_reallyold)
126SYSCTL_VNET_INT(_net_inet_ip, IPCTL_RTEXPIRE, rtexpire, CTLFLAG_RW,
127    &VNET_NAME(rtq_reallyold), 0,
128    "Default expiration time on dynamically learned routes");
129
130/* never automatically crank down to less */
131static VNET_DEFINE(int, rtq_minreallyold) = 10;
132#define	V_rtq_minreallyold	VNET(rtq_minreallyold)
133SYSCTL_VNET_INT(_net_inet_ip, IPCTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW,
134    &VNET_NAME(rtq_minreallyold), 0,
135    "Minimum time to attempt to hold onto dynamically learned routes");
136
137/* 128 cached routes is "too many" */
138static VNET_DEFINE(int, rtq_toomany) = 128;
139#define	V_rtq_toomany		VNET(rtq_toomany)
140SYSCTL_VNET_INT(_net_inet_ip, IPCTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW,
141    &VNET_NAME(rtq_toomany), 0,
142    "Upper limit on dynamically learned routes");
143
144/*
145 * On last reference drop, mark the route as belong to us so that it can be
146 * timed out.
147 */
148static void
149in_clsroute(struct radix_node *rn, struct radix_node_head *head)
150{
151	struct rtentry *rt = (struct rtentry *)rn;
152
153	RT_LOCK_ASSERT(rt);
154
155	if (!(rt->rt_flags & RTF_UP))
156		return;			/* prophylactic measures */
157
158	if (rt->rt_flags & RTPRF_OURS)
159		return;
160
161	if (!(rt->rt_flags & RTF_DYNAMIC))
162		return;
163
164	/*
165	 * If rtq_reallyold is 0, just delete the route without
166	 * waiting for a timeout cycle to kill it.
167	 */
168	if (V_rtq_reallyold != 0) {
169		rt->rt_flags |= RTPRF_OURS;
170		rt->rt_expire = time_uptime + V_rtq_reallyold;
171	} else {
172		rtexpunge(rt);
173	}
174}
175
176struct rtqk_arg {
177	struct radix_node_head *rnh;
178	int draining;
179	int killed;
180	int found;
181	int updating;
182	time_t nextstop;
183};
184
185/*
186 * Get rid of old routes.  When draining, this deletes everything, even when
187 * the timeout is not expired yet.  When updating, this makes sure that
188 * nothing has a timeout longer than the current value of rtq_reallyold.
189 */
190static int
191in_rtqkill(struct radix_node *rn, void *rock)
192{
193	struct rtqk_arg *ap = rock;
194	struct rtentry *rt = (struct rtentry *)rn;
195	int err;
196
197	RADIX_NODE_HEAD_WLOCK_ASSERT(ap->rnh);
198
199	if (rt->rt_flags & RTPRF_OURS) {
200		ap->found++;
201
202		if (ap->draining || rt->rt_expire <= time_uptime) {
203			if (rt->rt_refcnt > 0)
204				panic("rtqkill route really not free");
205
206			err = in_rtrequest(RTM_DELETE,
207					(struct sockaddr *)rt_key(rt),
208					rt->rt_gateway, rt_mask(rt),
209					rt->rt_flags | RTF_RNH_LOCKED, 0,
210					rt->rt_fibnum);
211			if (err) {
212				log(LOG_WARNING, "in_rtqkill: error %d\n", err);
213			} else {
214				ap->killed++;
215			}
216		} else {
217			if (ap->updating &&
218			    (rt->rt_expire - time_uptime > V_rtq_reallyold))
219				rt->rt_expire = time_uptime + V_rtq_reallyold;
220			ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
221		}
222	}
223
224	return 0;
225}
226
227#define RTQ_TIMEOUT	60*10	/* run no less than once every ten minutes */
228static VNET_DEFINE(int, rtq_timeout) = RTQ_TIMEOUT;
229static VNET_DEFINE(struct callout, rtq_timer);
230
231#define	V_rtq_timeout		VNET(rtq_timeout)
232#define	V_rtq_timer		VNET(rtq_timer)
233
234static void in_rtqtimo_one(void *rock);
235
236static void
237in_rtqtimo(void *rock)
238{
239	CURVNET_SET((struct vnet *) rock);
240	int fibnum;
241	void *newrock;
242	struct timeval atv;
243
244	for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
245		newrock = rt_tables_get_rnh(fibnum, AF_INET);
246		if (newrock != NULL)
247			in_rtqtimo_one(newrock);
248	}
249	atv.tv_usec = 0;
250	atv.tv_sec = V_rtq_timeout;
251	callout_reset(&V_rtq_timer, tvtohz(&atv), in_rtqtimo, rock);
252	CURVNET_RESTORE();
253}
254
255static void
256in_rtqtimo_one(void *rock)
257{
258	struct radix_node_head *rnh = rock;
259	struct rtqk_arg arg;
260	static time_t last_adjusted_timeout = 0;
261
262	arg.found = arg.killed = 0;
263	arg.rnh = rnh;
264	arg.nextstop = time_uptime + V_rtq_timeout;
265	arg.draining = arg.updating = 0;
266	RADIX_NODE_HEAD_LOCK(rnh);
267	rnh->rnh_walktree(rnh, in_rtqkill, &arg);
268	RADIX_NODE_HEAD_UNLOCK(rnh);
269
270	/*
271	 * Attempt to be somewhat dynamic about this:
272	 * If there are ``too many'' routes sitting around taking up space,
273	 * then crank down the timeout, and see if we can't make some more
274	 * go away.  However, we make sure that we will never adjust more
275	 * than once in rtq_timeout seconds, to keep from cranking down too
276	 * hard.
277	 */
278	if ((arg.found - arg.killed > V_rtq_toomany) &&
279	    (time_uptime - last_adjusted_timeout >= V_rtq_timeout) &&
280	    V_rtq_reallyold > V_rtq_minreallyold) {
281		V_rtq_reallyold = 2 * V_rtq_reallyold / 3;
282		if (V_rtq_reallyold < V_rtq_minreallyold) {
283			V_rtq_reallyold = V_rtq_minreallyold;
284		}
285
286		last_adjusted_timeout = time_uptime;
287#ifdef DIAGNOSTIC
288		log(LOG_DEBUG, "in_rtqtimo: adjusted rtq_reallyold to %d\n",
289		    V_rtq_reallyold);
290#endif
291		arg.found = arg.killed = 0;
292		arg.updating = 1;
293		RADIX_NODE_HEAD_LOCK(rnh);
294		rnh->rnh_walktree(rnh, in_rtqkill, &arg);
295		RADIX_NODE_HEAD_UNLOCK(rnh);
296	}
297
298}
299
300void
301in_rtqdrain(void)
302{
303	VNET_ITERATOR_DECL(vnet_iter);
304	struct radix_node_head *rnh;
305	struct rtqk_arg arg;
306	int 	fibnum;
307
308	VNET_LIST_RLOCK_NOSLEEP();
309	VNET_FOREACH(vnet_iter) {
310		CURVNET_SET(vnet_iter);
311
312		for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) {
313			rnh = rt_tables_get_rnh(fibnum, AF_INET);
314			arg.found = arg.killed = 0;
315			arg.rnh = rnh;
316			arg.nextstop = 0;
317			arg.draining = 1;
318			arg.updating = 0;
319			RADIX_NODE_HEAD_LOCK(rnh);
320			rnh->rnh_walktree(rnh, in_rtqkill, &arg);
321			RADIX_NODE_HEAD_UNLOCK(rnh);
322		}
323		CURVNET_RESTORE();
324	}
325	VNET_LIST_RUNLOCK_NOSLEEP();
326}
327
328void
329in_setmatchfunc(struct radix_node_head *rnh, int val)
330{
331
332	rnh->rnh_matchaddr = (val != 0) ? rn_match : in_matroute;
333}
334
335static int _in_rt_was_here;
336/*
337 * Initialize our routing tree.
338 */
339int
340in_inithead(void **head, int off)
341{
342	struct radix_node_head *rnh;
343
344	/* XXX MRT
345	 * This can be called from vfs_export.c too in which case 'off'
346	 * will be 0. We know the correct value so just use that and
347	 * return directly if it was 0.
348	 * This is a hack that replaces an even worse hack on a bad hack
349	 * on a bad design. After RELENG_7 this should be fixed but that
350	 * will change the ABI, so for now do it this way.
351	 */
352	if (!rn_inithead(head, 32))
353		return 0;
354
355	if (off == 0)		/* XXX MRT  see above */
356		return 1;	/* only do the rest for a real routing table */
357
358	rnh = *head;
359	rnh->rnh_addaddr = in_addroute;
360	in_setmatchfunc(rnh, V_drop_redirect);
361	rnh->rnh_close = in_clsroute;
362	if (_in_rt_was_here == 0 ) {
363		callout_init(&V_rtq_timer, CALLOUT_MPSAFE);
364		callout_reset(&V_rtq_timer, 1, in_rtqtimo, curvnet);
365		_in_rt_was_here = 1;
366	}
367	return 1;
368}
369
370#ifdef VIMAGE
371int
372in_detachhead(void **head, int off)
373{
374
375	callout_drain(&V_rtq_timer);
376	return (rn_detachhead(head));
377}
378#endif
379
380/*
381 * This zaps old routes when the interface goes down or interface
382 * address is deleted.  In the latter case, it deletes static routes
383 * that point to this address.  If we don't do this, we may end up
384 * using the old address in the future.  The ones we always want to
385 * get rid of are things like ARP entries, since the user might down
386 * the interface, walk over to a completely different network, and
387 * plug back in.
388 */
389struct in_ifadown_arg {
390	struct ifaddr *ifa;
391	int del;
392};
393
394static int
395in_ifadownkill(struct radix_node *rn, void *xap)
396{
397	struct in_ifadown_arg *ap = xap;
398	struct rtentry *rt = (struct rtentry *)rn;
399
400	RT_LOCK(rt);
401	if (rt->rt_ifa == ap->ifa &&
402	    (ap->del || !(rt->rt_flags & RTF_STATIC))) {
403		/*
404		 * Aquire a reference so that it can later be freed
405		 * as the refcount would be 0 here in case of at least
406		 * ap->del.
407		 */
408		RT_ADDREF(rt);
409		/*
410		 * Disconnect it from the tree and permit protocols
411		 * to cleanup.
412		 */
413		rtexpunge(rt);
414		/*
415		 * At this point it is an rttrash node, and in case
416		 * the above is the only reference we must free it.
417		 * If we do not noone will have a pointer and the
418		 * rtentry will be leaked forever.
419		 * In case someone else holds a reference, we are
420		 * fine as we only decrement the refcount. In that
421		 * case if the other entity calls RT_REMREF, we
422		 * will still be leaking but at least we tried.
423		 */
424		RTFREE_LOCKED(rt);
425		return (0);
426	}
427	RT_UNLOCK(rt);
428	return 0;
429}
430
431int
432in_ifadown(struct ifaddr *ifa, int delete)
433{
434	struct in_ifadown_arg arg;
435	struct radix_node_head *rnh;
436	int	fibnum;
437
438	if (ifa->ifa_addr->sa_family != AF_INET)
439		return 1;
440
441	for ( fibnum = 0; fibnum < rt_numfibs; fibnum++) {
442		rnh = rt_tables_get_rnh(fibnum, AF_INET);
443		arg.ifa = ifa;
444		arg.del = delete;
445		RADIX_NODE_HEAD_LOCK(rnh);
446		rnh->rnh_walktree(rnh, in_ifadownkill, &arg);
447		RADIX_NODE_HEAD_UNLOCK(rnh);
448		ifa->ifa_flags &= ~IFA_ROUTE;		/* XXXlocking? */
449	}
450	return 0;
451}
452
453/*
454 * inet versions of rt functions. These have fib extensions and
455 * for now will just reference the _fib variants.
456 * eventually this order will be reversed,
457 */
458void
459in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum)
460{
461	rtalloc_ign_fib(ro, ignflags, fibnum);
462}
463
464int
465in_rtrequest( int req,
466	struct sockaddr *dst,
467	struct sockaddr *gateway,
468	struct sockaddr *netmask,
469	int flags,
470	struct rtentry **ret_nrt,
471	u_int fibnum)
472{
473	return (rtrequest_fib(req, dst, gateway, netmask,
474	    flags, ret_nrt, fibnum));
475}
476
477struct rtentry *
478in_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum)
479{
480	return (rtalloc1_fib(dst, report, ignflags, fibnum));
481}
482
483void
484in_rtredirect(struct sockaddr *dst,
485	struct sockaddr *gateway,
486	struct sockaddr *netmask,
487	int flags,
488	struct sockaddr *src,
489	u_int fibnum)
490{
491	rtredirect_fib(dst, gateway, netmask, flags, src, fibnum);
492}
493
494void
495in_rtalloc(struct route *ro, u_int fibnum)
496{
497	rtalloc_ign_fib(ro, 0UL, fibnum);
498}
499
500#if 0
501int	 in_rt_getifa(struct rt_addrinfo *, u_int fibnum);
502int	 in_rtioctl(u_long, caddr_t, u_int);
503int	 in_rtrequest1(int, struct rt_addrinfo *, struct rtentry **, u_int);
504#endif
505
506
507