xref: /freebsd/sys/netinet6/in6_rmx.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
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/queue.h>
70 #include <sys/socket.h>
71 #include <sys/socketvar.h>
72 #include <sys/mbuf.h>
73 #include <sys/rwlock.h>
74 #include <sys/syslog.h>
75 #include <sys/callout.h>
76 
77 #include <net/if.h>
78 #include <net/if_var.h>
79 #include <net/route.h>
80 
81 #include <netinet/in.h>
82 #include <netinet/ip_var.h>
83 #include <netinet/in_var.h>
84 
85 #include <netinet/ip6.h>
86 #include <netinet6/ip6_var.h>
87 
88 #include <netinet/icmp6.h>
89 #include <netinet6/nd6.h>
90 
91 #include <netinet/tcp.h>
92 #include <netinet/tcp_seq.h>
93 #include <netinet/tcp_timer.h>
94 #include <netinet/tcp_var.h>
95 
96 extern int	in6_inithead(void **head, int off);
97 #ifdef VIMAGE
98 extern int	in6_detachhead(void **head, int off);
99 #endif
100 
101 /*
102  * Do what we need to do when inserting a route.
103  */
104 static struct radix_node *
105 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
106     struct radix_node *treenodes)
107 {
108 	struct rtentry *rt = (struct rtentry *)treenodes;
109 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt);
110 	struct radix_node *ret;
111 
112 	RADIX_NODE_HEAD_WLOCK_ASSERT(head);
113 	if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
114 		rt->rt_flags |= RTF_MULTICAST;
115 
116 	/*
117 	 * A little bit of help for both IPv6 output and input:
118 	 *   For local addresses, we make sure that RTF_LOCAL is set,
119 	 *   with the thought that this might one day be used to speed up
120 	 *   ip_input().
121 	 *
122 	 * We also mark routes to multicast addresses as such, because
123 	 * it's easy to do and might be useful (but this is much more
124 	 * dubious since it's so easy to inspect the address).  (This
125 	 * is done above.)
126 	 *
127 	 * XXX
128 	 * should elaborate the code.
129 	 */
130 	if (rt->rt_flags & RTF_HOST) {
131 		if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)
132 					->sin6_addr,
133 				       &sin6->sin6_addr)) {
134 			rt->rt_flags |= RTF_LOCAL;
135 		}
136 	}
137 
138 	if (rt->rt_ifp != NULL) {
139 
140 		/*
141 		 * Check route MTU:
142 		 * inherit interface MTU if not set or
143 		 * check if MTU is too large.
144 		 */
145 		if (rt->rt_mtu == 0) {
146 			rt->rt_mtu = IN6_LINKMTU(rt->rt_ifp);
147 		} else if (rt->rt_mtu > IN6_LINKMTU(rt->rt_ifp))
148 			rt->rt_mtu = IN6_LINKMTU(rt->rt_ifp);
149 	}
150 
151 	ret = rn_addroute(v_arg, n_arg, head, treenodes);
152 	if (ret == NULL) {
153 		struct rtentry *rt2;
154 		/*
155 		 * We are trying to add a net route, but can't.
156 		 * The following case should be allowed, so we'll make a
157 		 * special check for this:
158 		 *	Two IPv6 addresses with the same prefix is assigned
159 		 *	to a single interrface.
160 		 *	# ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
161 		 *	# ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
162 		 *	In this case, (*1) and (*2) want to add the same
163 		 *	net route entry, 3ffe:0501:: -> if0.
164 		 *	This case should not raise an error.
165 		 */
166 		rt2 = in6_rtalloc1((struct sockaddr *)sin6, 0, RTF_RNH_LOCKED,
167 		    rt->rt_fibnum);
168 		if (rt2) {
169 			if (((rt2->rt_flags & (RTF_HOST|RTF_GATEWAY)) == 0)
170 			 && rt2->rt_gateway
171 			 && rt2->rt_gateway->sa_family == AF_LINK
172 			 && rt2->rt_ifp == rt->rt_ifp) {
173 				ret = rt2->rt_nodes;
174 			}
175 			RTFREE_LOCKED(rt2);
176 		}
177 	}
178 	return (ret);
179 }
180 
181 /*
182  * Age old PMTUs.
183  */
184 struct mtuex_arg {
185 	struct radix_node_head *rnh;
186 	time_t nextstop;
187 };
188 static VNET_DEFINE(struct callout, rtq_mtutimer);
189 #define	V_rtq_mtutimer			VNET(rtq_mtutimer)
190 
191 static int
192 in6_mtuexpire(struct radix_node *rn, void *rock)
193 {
194 	struct rtentry *rt = (struct rtentry *)rn;
195 	struct mtuex_arg *ap = rock;
196 
197 	/* sanity */
198 	if (!rt)
199 		panic("rt == NULL in in6_mtuexpire");
200 
201 	if (rt->rt_expire && !(rt->rt_flags & RTF_PROBEMTU)) {
202 		if (rt->rt_expire <= time_uptime) {
203 			rt->rt_flags |= RTF_PROBEMTU;
204 		} else {
205 			ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
206 		}
207 	}
208 
209 	return 0;
210 }
211 
212 #define	MTUTIMO_DEFAULT	(60*1)
213 
214 static void
215 in6_mtutimo_one(struct radix_node_head *rnh)
216 {
217 	struct mtuex_arg arg;
218 
219 	arg.rnh = rnh;
220 	arg.nextstop = time_uptime + MTUTIMO_DEFAULT;
221 	RADIX_NODE_HEAD_LOCK(rnh);
222 	rnh->rnh_walktree(rnh, in6_mtuexpire, &arg);
223 	RADIX_NODE_HEAD_UNLOCK(rnh);
224 }
225 
226 static void
227 in6_mtutimo(void *rock)
228 {
229 	CURVNET_SET_QUIET((struct vnet *) rock);
230 	struct radix_node_head *rnh;
231 	struct timeval atv;
232 	u_int fibnum;
233 
234 	for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
235 		rnh = rt_tables_get_rnh(fibnum, AF_INET6);
236 		if (rnh != NULL)
237 			in6_mtutimo_one(rnh);
238 	}
239 
240 	atv.tv_sec = MTUTIMO_DEFAULT;
241 	atv.tv_usec = 0;
242 	callout_reset(&V_rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock);
243 	CURVNET_RESTORE();
244 }
245 
246 /*
247  * Initialize our routing tree.
248  */
249 static VNET_DEFINE(int, _in6_rt_was_here);
250 #define	V__in6_rt_was_here	VNET(_in6_rt_was_here)
251 
252 int
253 in6_inithead(void **head, int off)
254 {
255 	struct radix_node_head *rnh;
256 
257 	if (!rn_inithead(head, offsetof(struct sockaddr_in6, sin6_addr) << 3))
258 		return (0);
259 
260 	rnh = *head;
261 	RADIX_NODE_HEAD_LOCK_INIT(rnh);
262 
263 	rnh->rnh_addaddr = in6_addroute;
264 
265 	if (V__in6_rt_was_here == 0) {
266 		callout_init(&V_rtq_mtutimer, 1);
267 		in6_mtutimo(curvnet);	/* kick off timeout first time */
268 		V__in6_rt_was_here = 1;
269 	}
270 
271 	return (1);
272 }
273 
274 #ifdef VIMAGE
275 int
276 in6_detachhead(void **head, int off)
277 {
278 
279 	callout_drain(&V_rtq_mtutimer);
280 	return (1);
281 }
282 #endif
283 
284 /*
285  * Extended API for IPv6 FIB support.
286  */
287 void
288 in6_rtredirect(struct sockaddr *dst, struct sockaddr *gw, struct sockaddr *nm,
289     int flags, struct sockaddr *src, u_int fibnum)
290 {
291 
292 	rtredirect_fib(dst, gw, nm, flags, src, fibnum);
293 }
294 
295 int
296 in6_rtrequest(int req, struct sockaddr *dst, struct sockaddr *gw,
297     struct sockaddr *mask, int flags, struct rtentry **ret_nrt, u_int fibnum)
298 {
299 
300 	return (rtrequest_fib(req, dst, gw, mask, flags, ret_nrt, fibnum));
301 }
302 
303 void
304 in6_rtalloc(struct route_in6 *ro, u_int fibnum)
305 {
306 
307 	rtalloc_ign_fib((struct route *)ro, 0ul, fibnum);
308 }
309 
310 void
311 in6_rtalloc_ign(struct route_in6 *ro, u_long ignflags, u_int fibnum)
312 {
313 
314 	rtalloc_ign_fib((struct route *)ro, ignflags, fibnum);
315 }
316 
317 struct rtentry *
318 in6_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum)
319 {
320 
321 	return (rtalloc1_fib(dst, report, ignflags, fibnum));
322 }
323