xref: /freebsd/sys/netinet6/in6_rmx.c (revision 4465557ac2231bcaa4f82da5278949c313491970)
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 #include <sys/cdefs.h>
63 __FBSDID("$FreeBSD$");
64 
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/kernel.h>
68 #include <sys/lock.h>
69 #include <sys/sysctl.h>
70 #include <sys/queue.h>
71 #include <sys/socket.h>
72 #include <sys/socketvar.h>
73 #include <sys/mbuf.h>
74 #include <sys/rwlock.h>
75 #include <sys/syslog.h>
76 #include <sys/callout.h>
77 
78 #include <net/if.h>
79 #include <net/if_var.h>
80 #include <net/route.h>
81 
82 #include <netinet/in.h>
83 #include <netinet/ip_var.h>
84 #include <netinet/in_var.h>
85 
86 #include <netinet/ip6.h>
87 #include <netinet6/ip6_var.h>
88 
89 #include <netinet/icmp6.h>
90 #include <netinet6/nd6.h>
91 
92 #include <netinet/tcp.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 
97 extern int	in6_inithead(void **head, int off);
98 #ifdef VIMAGE
99 extern int	in6_detachhead(void **head, int off);
100 #endif
101 
102 /*
103  * Do what we need to do when inserting a route.
104  */
105 static struct radix_node *
106 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
107     struct radix_node *treenodes)
108 {
109 	struct rtentry *rt = (struct rtentry *)treenodes;
110 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt);
111 	struct radix_node *ret;
112 
113 	RADIX_NODE_HEAD_WLOCK_ASSERT(head);
114 	if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
115 		rt->rt_flags |= RTF_MULTICAST;
116 
117 	/*
118 	 * A little bit of help for both IPv6 output and input:
119 	 *   For local addresses, we make sure that RTF_LOCAL is set,
120 	 *   with the thought that this might one day be used to speed up
121 	 *   ip_input().
122 	 *
123 	 * We also mark routes to multicast addresses as such, because
124 	 * it's easy to do and might be useful (but this is much more
125 	 * dubious since it's so easy to inspect the address).  (This
126 	 * is done above.)
127 	 *
128 	 * XXX
129 	 * should elaborate the code.
130 	 */
131 	if (rt->rt_flags & RTF_HOST) {
132 		if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)
133 					->sin6_addr,
134 				       &sin6->sin6_addr)) {
135 			rt->rt_flags |= RTF_LOCAL;
136 		}
137 	}
138 
139 	if (rt->rt_ifp != NULL) {
140 
141 		/*
142 		 * Check route MTU:
143 		 * inherit interface MTU if not set or
144 		 * check if MTU is too large.
145 		 */
146 		if (rt->rt_mtu == 0) {
147 			rt->rt_mtu = IN6_LINKMTU(rt->rt_ifp);
148 		} else if (rt->rt_mtu > IN6_LINKMTU(rt->rt_ifp))
149 			rt->rt_mtu = IN6_LINKMTU(rt->rt_ifp);
150 	}
151 
152 	ret = rn_addroute(v_arg, n_arg, head, treenodes);
153 	if (ret == NULL) {
154 		struct rtentry *rt2;
155 		/*
156 		 * We are trying to add a net route, but can't.
157 		 * The following case should be allowed, so we'll make a
158 		 * special check for this:
159 		 *	Two IPv6 addresses with the same prefix is assigned
160 		 *	to a single interrface.
161 		 *	# ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
162 		 *	# ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
163 		 *	In this case, (*1) and (*2) want to add the same
164 		 *	net route entry, 3ffe:0501:: -> if0.
165 		 *	This case should not raise an error.
166 		 */
167 		rt2 = in6_rtalloc1((struct sockaddr *)sin6, 0, RTF_RNH_LOCKED,
168 		    rt->rt_fibnum);
169 		if (rt2) {
170 			if (((rt2->rt_flags & (RTF_HOST|RTF_GATEWAY)) == 0)
171 			 && rt2->rt_gateway
172 			 && rt2->rt_gateway->sa_family == AF_LINK
173 			 && rt2->rt_ifp == rt->rt_ifp) {
174 				ret = rt2->rt_nodes;
175 			}
176 			RTFREE_LOCKED(rt2);
177 		}
178 	}
179 	return (ret);
180 }
181 
182 SYSCTL_DECL(_net_inet6_ip6);
183 
184 static VNET_DEFINE(int, rtq_toomany6) = 128;
185 	/* 128 cached routes is ``too many'' */
186 #define	V_rtq_toomany6			VNET(rtq_toomany6)
187 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW,
188     &VNET_NAME(rtq_toomany6) , 0, "");
189 
190 struct rtqk_arg {
191 	struct radix_node_head *rnh;
192 	int mode;
193 	int updating;
194 	int draining;
195 	int killed;
196 	int found;
197 	time_t nextstop;
198 };
199 
200 /*
201  * Age old PMTUs.
202  */
203 struct mtuex_arg {
204 	struct radix_node_head *rnh;
205 	time_t nextstop;
206 };
207 static VNET_DEFINE(struct callout, rtq_mtutimer);
208 #define	V_rtq_mtutimer			VNET(rtq_mtutimer)
209 
210 static int
211 in6_mtuexpire(struct radix_node *rn, void *rock)
212 {
213 	struct rtentry *rt = (struct rtentry *)rn;
214 	struct mtuex_arg *ap = rock;
215 
216 	/* sanity */
217 	if (!rt)
218 		panic("rt == NULL in in6_mtuexpire");
219 
220 	if (rt->rt_expire && !(rt->rt_flags & RTF_PROBEMTU)) {
221 		if (rt->rt_expire <= time_uptime) {
222 			rt->rt_flags |= RTF_PROBEMTU;
223 		} else {
224 			ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
225 		}
226 	}
227 
228 	return 0;
229 }
230 
231 #define	MTUTIMO_DEFAULT	(60*1)
232 
233 static void
234 in6_mtutimo_one(struct radix_node_head *rnh)
235 {
236 	struct mtuex_arg arg;
237 
238 	arg.rnh = rnh;
239 	arg.nextstop = time_uptime + MTUTIMO_DEFAULT;
240 	RADIX_NODE_HEAD_LOCK(rnh);
241 	rnh->rnh_walktree(rnh, in6_mtuexpire, &arg);
242 	RADIX_NODE_HEAD_UNLOCK(rnh);
243 }
244 
245 static void
246 in6_mtutimo(void *rock)
247 {
248 	CURVNET_SET_QUIET((struct vnet *) rock);
249 	struct radix_node_head *rnh;
250 	struct timeval atv;
251 	u_int fibnum;
252 
253 	for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
254 		rnh = rt_tables_get_rnh(fibnum, AF_INET6);
255 		if (rnh != NULL)
256 			in6_mtutimo_one(rnh);
257 	}
258 
259 	atv.tv_sec = MTUTIMO_DEFAULT;
260 	atv.tv_usec = 0;
261 	callout_reset(&V_rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock);
262 	CURVNET_RESTORE();
263 }
264 
265 /*
266  * Initialize our routing tree.
267  */
268 static VNET_DEFINE(int, _in6_rt_was_here);
269 #define	V__in6_rt_was_here	VNET(_in6_rt_was_here)
270 
271 int
272 in6_inithead(void **head, int off)
273 {
274 	struct radix_node_head *rnh;
275 
276 	if (!rn_inithead(head, offsetof(struct sockaddr_in6, sin6_addr) << 3))
277 		return (0);
278 
279 	rnh = *head;
280 	RADIX_NODE_HEAD_LOCK_INIT(rnh);
281 
282 	rnh->rnh_addaddr = in6_addroute;
283 
284 	if (V__in6_rt_was_here == 0) {
285 		callout_init(&V_rtq_mtutimer, CALLOUT_MPSAFE);
286 		in6_mtutimo(curvnet);	/* kick off timeout first time */
287 		V__in6_rt_was_here = 1;
288 	}
289 
290 	return (1);
291 }
292 
293 #ifdef VIMAGE
294 int
295 in6_detachhead(void **head, int off)
296 {
297 
298 	callout_drain(&V_rtq_mtutimer);
299 	return (1);
300 }
301 #endif
302 
303 /*
304  * Extended API for IPv6 FIB support.
305  */
306 void
307 in6_rtredirect(struct sockaddr *dst, struct sockaddr *gw, struct sockaddr *nm,
308     int flags, struct sockaddr *src, u_int fibnum)
309 {
310 
311 	rtredirect_fib(dst, gw, nm, flags, src, fibnum);
312 }
313 
314 int
315 in6_rtrequest(int req, struct sockaddr *dst, struct sockaddr *gw,
316     struct sockaddr *mask, int flags, struct rtentry **ret_nrt, u_int fibnum)
317 {
318 
319 	return (rtrequest_fib(req, dst, gw, mask, flags, ret_nrt, fibnum));
320 }
321 
322 void
323 in6_rtalloc(struct route_in6 *ro, u_int fibnum)
324 {
325 
326 	rtalloc_ign_fib((struct route *)ro, 0ul, fibnum);
327 }
328 
329 void
330 in6_rtalloc_ign(struct route_in6 *ro, u_long ignflags, u_int fibnum)
331 {
332 
333 	rtalloc_ign_fib((struct route *)ro, ignflags, fibnum);
334 }
335 
336 struct rtentry *
337 in6_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum)
338 {
339 
340 	return (rtalloc1_fib(dst, report, ignflags, fibnum));
341 }
342