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 /* 63 * This code does two things necessary for the enhanced TCP metrics to 64 * function in a useful manner: 65 * 1) It marks all non-host routes as `cloning', thus ensuring that 66 * every actual reference to such a route actually gets turned 67 * into a reference to a host route to the specific destination 68 * requested. 69 * 2) When such routes lose all their references, it arranges for them 70 * to be deleted in some random collection of circumstances, so that 71 * a large quantity of stale routing data is not kept in kernel memory 72 * indefinitely. See in6_rtqtimo() below for the exact mechanism. 73 */ 74 75 #include <sys/cdefs.h> 76 __FBSDID("$FreeBSD$"); 77 78 #include "opt_route.h" 79 80 #include <sys/param.h> 81 #include <sys/systm.h> 82 #include <sys/kernel.h> 83 #include <sys/lock.h> 84 #include <sys/sysctl.h> 85 #include <sys/queue.h> 86 #include <sys/socket.h> 87 #include <sys/socketvar.h> 88 #include <sys/mbuf.h> 89 #include <sys/rwlock.h> 90 #include <sys/syslog.h> 91 #include <sys/callout.h> 92 #include <sys/vimage.h> 93 94 #include <net/if.h> 95 #include <net/route.h> 96 #include <net/vnet.h> 97 98 #include <netinet/in.h> 99 #include <netinet/ip_var.h> 100 #include <netinet/in_var.h> 101 102 #include <netinet/ip6.h> 103 #include <netinet6/ip6_var.h> 104 105 #include <netinet/icmp6.h> 106 #include <netinet6/nd6.h> 107 #include <netinet6/vinet6.h> 108 109 #include <netinet/tcp.h> 110 #include <netinet/tcp_seq.h> 111 #include <netinet/tcp_timer.h> 112 #include <netinet/tcp_var.h> 113 114 extern int in6_inithead(void **head, int off); 115 116 #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */ 117 118 /* 119 * Do what we need to do when inserting a route. 120 */ 121 static struct radix_node * 122 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, 123 struct radix_node *treenodes) 124 { 125 struct rtentry *rt = (struct rtentry *)treenodes; 126 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt); 127 struct radix_node *ret; 128 129 RADIX_NODE_HEAD_WLOCK_ASSERT(head); 130 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 131 rt->rt_flags |= RTF_MULTICAST; 132 133 /* 134 * A little bit of help for both IPv6 output and input: 135 * For local addresses, we make sure that RTF_LOCAL is set, 136 * with the thought that this might one day be used to speed up 137 * ip_input(). 138 * 139 * We also mark routes to multicast addresses as such, because 140 * it's easy to do and might be useful (but this is much more 141 * dubious since it's so easy to inspect the address). (This 142 * is done above.) 143 * 144 * XXX 145 * should elaborate the code. 146 */ 147 if (rt->rt_flags & RTF_HOST) { 148 if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr) 149 ->sin6_addr, 150 &sin6->sin6_addr)) { 151 rt->rt_flags |= RTF_LOCAL; 152 } 153 } 154 155 if (!rt->rt_rmx.rmx_mtu && rt->rt_ifp) 156 rt->rt_rmx.rmx_mtu = IN6_LINKMTU(rt->rt_ifp); 157 158 ret = rn_addroute(v_arg, n_arg, head, treenodes); 159 if (ret == NULL) { 160 struct rtentry *rt2; 161 /* 162 * We are trying to add a net route, but can't. 163 * The following case should be allowed, so we'll make a 164 * special check for this: 165 * Two IPv6 addresses with the same prefix is assigned 166 * to a single interrface. 167 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1) 168 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2) 169 * In this case, (*1) and (*2) want to add the same 170 * net route entry, 3ffe:0501:: -> if0. 171 * This case should not raise an error. 172 */ 173 rt2 = rtalloc1((struct sockaddr *)sin6, 0, RTF_RNH_LOCKED); 174 if (rt2) { 175 if (((rt2->rt_flags & (RTF_HOST|RTF_GATEWAY)) == 0) 176 && rt2->rt_gateway 177 && rt2->rt_gateway->sa_family == AF_LINK 178 && rt2->rt_ifp == rt->rt_ifp) { 179 ret = rt2->rt_nodes; 180 } 181 RTFREE_LOCKED(rt2); 182 } 183 } 184 return (ret); 185 } 186 187 /* 188 * This code is the inverse of in6_clsroute: on first reference, if we 189 * were managing the route, stop doing so and set the expiration timer 190 * back off again. 191 */ 192 static struct radix_node * 193 in6_matroute(void *v_arg, struct radix_node_head *head) 194 { 195 struct radix_node *rn = rn_match(v_arg, head); 196 struct rtentry *rt = (struct rtentry *)rn; 197 198 if (rt && rt->rt_refcnt == 0) { /* this is first reference */ 199 if (rt->rt_flags & RTPRF_OURS) { 200 rt->rt_flags &= ~RTPRF_OURS; 201 rt->rt_rmx.rmx_expire = 0; 202 } 203 } 204 return rn; 205 } 206 207 SYSCTL_DECL(_net_inet6_ip6); 208 209 #ifdef VIMAGE_GLOBALS 210 static int rtq_reallyold6; 211 static int rtq_minreallyold6; 212 static int rtq_toomany6; 213 #endif 214 215 SYSCTL_V_INT(V_NET, vnet_inet6, _net_inet6_ip6, IPV6CTL_RTEXPIRE, 216 rtexpire, CTLFLAG_RW, rtq_reallyold6 , 0, ""); 217 218 SYSCTL_V_INT(V_NET, vnet_inet6, _net_inet6_ip6, IPV6CTL_RTMINEXPIRE, 219 rtminexpire, CTLFLAG_RW, rtq_minreallyold6 , 0, ""); 220 221 SYSCTL_V_INT(V_NET, vnet_inet6, _net_inet6_ip6, IPV6CTL_RTMAXCACHE, 222 rtmaxcache, CTLFLAG_RW, rtq_toomany6 , 0, ""); 223 224 225 226 struct rtqk_arg { 227 struct radix_node_head *rnh; 228 int mode; 229 int updating; 230 int draining; 231 int killed; 232 int found; 233 time_t nextstop; 234 }; 235 236 /* 237 * Get rid of old routes. When draining, this deletes everything, even when 238 * the timeout is not expired yet. When updating, this makes sure that 239 * nothing has a timeout longer than the current value of rtq_reallyold6. 240 */ 241 static int 242 in6_rtqkill(struct radix_node *rn, void *rock) 243 { 244 INIT_VNET_INET6(curvnet); 245 struct rtqk_arg *ap = rock; 246 struct rtentry *rt = (struct rtentry *)rn; 247 int err; 248 249 RADIX_NODE_HEAD_WLOCK_ASSERT(ap->rnh); 250 251 if (rt->rt_flags & RTPRF_OURS) { 252 ap->found++; 253 254 if (ap->draining || rt->rt_rmx.rmx_expire <= time_uptime) { 255 if (rt->rt_refcnt > 0) 256 panic("rtqkill route really not free"); 257 258 err = rtrequest(RTM_DELETE, 259 (struct sockaddr *)rt_key(rt), 260 rt->rt_gateway, rt_mask(rt), 261 rt->rt_flags|RTF_RNH_LOCKED, 0); 262 if (err) { 263 log(LOG_WARNING, "in6_rtqkill: error %d", err); 264 } else { 265 ap->killed++; 266 } 267 } else { 268 if (ap->updating 269 && (rt->rt_rmx.rmx_expire - time_uptime 270 > V_rtq_reallyold6)) { 271 rt->rt_rmx.rmx_expire = time_uptime 272 + V_rtq_reallyold6; 273 } 274 ap->nextstop = lmin(ap->nextstop, 275 rt->rt_rmx.rmx_expire); 276 } 277 } 278 279 return 0; 280 } 281 282 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */ 283 #ifdef VIMAGE_GLOBALS 284 static int rtq_timeout6; 285 static struct callout rtq_timer6; 286 #endif 287 288 static void 289 in6_rtqtimo(void *rock) 290 { 291 CURVNET_SET_QUIET((struct vnet *) rock); 292 INIT_VNET_NET((struct vnet *) rock); 293 INIT_VNET_INET6((struct vnet *) rock); 294 struct radix_node_head *rnh = rock; 295 struct rtqk_arg arg; 296 struct timeval atv; 297 static time_t last_adjusted_timeout = 0; 298 299 arg.found = arg.killed = 0; 300 arg.rnh = rnh; 301 arg.nextstop = time_uptime + V_rtq_timeout6; 302 arg.draining = arg.updating = 0; 303 RADIX_NODE_HEAD_LOCK(rnh); 304 rnh->rnh_walktree(rnh, in6_rtqkill, &arg); 305 RADIX_NODE_HEAD_UNLOCK(rnh); 306 307 /* 308 * Attempt to be somewhat dynamic about this: 309 * If there are ``too many'' routes sitting around taking up space, 310 * then crank down the timeout, and see if we can't make some more 311 * go away. However, we make sure that we will never adjust more 312 * than once in rtq_timeout6 seconds, to keep from cranking down too 313 * hard. 314 */ 315 if ((arg.found - arg.killed > V_rtq_toomany6) 316 && (time_uptime - last_adjusted_timeout >= V_rtq_timeout6) 317 && V_rtq_reallyold6 > V_rtq_minreallyold6) { 318 V_rtq_reallyold6 = 2*V_rtq_reallyold6 / 3; 319 if (V_rtq_reallyold6 < V_rtq_minreallyold6) { 320 V_rtq_reallyold6 = V_rtq_minreallyold6; 321 } 322 323 last_adjusted_timeout = time_uptime; 324 #ifdef DIAGNOSTIC 325 log(LOG_DEBUG, "in6_rtqtimo: adjusted rtq_reallyold6 to %d", 326 V_rtq_reallyold6); 327 #endif 328 arg.found = arg.killed = 0; 329 arg.updating = 1; 330 RADIX_NODE_HEAD_LOCK(rnh); 331 rnh->rnh_walktree(rnh, in6_rtqkill, &arg); 332 RADIX_NODE_HEAD_UNLOCK(rnh); 333 } 334 335 atv.tv_usec = 0; 336 atv.tv_sec = arg.nextstop - time_uptime; 337 callout_reset(&V_rtq_timer6, tvtohz(&atv), in6_rtqtimo, rock); 338 CURVNET_RESTORE(); 339 } 340 341 /* 342 * Age old PMTUs. 343 */ 344 struct mtuex_arg { 345 struct radix_node_head *rnh; 346 time_t nextstop; 347 }; 348 #ifdef VIMAGE_GLOBALS 349 static struct callout rtq_mtutimer; 350 #endif 351 352 static int 353 in6_mtuexpire(struct radix_node *rn, void *rock) 354 { 355 struct rtentry *rt = (struct rtentry *)rn; 356 struct mtuex_arg *ap = rock; 357 358 /* sanity */ 359 if (!rt) 360 panic("rt == NULL in in6_mtuexpire"); 361 362 if (rt->rt_rmx.rmx_expire && !(rt->rt_flags & RTF_PROBEMTU)) { 363 if (rt->rt_rmx.rmx_expire <= time_uptime) { 364 rt->rt_flags |= RTF_PROBEMTU; 365 } else { 366 ap->nextstop = lmin(ap->nextstop, 367 rt->rt_rmx.rmx_expire); 368 } 369 } 370 371 return 0; 372 } 373 374 #define MTUTIMO_DEFAULT (60*1) 375 376 static void 377 in6_mtutimo(void *rock) 378 { 379 CURVNET_SET_QUIET((struct vnet *) rock); 380 INIT_VNET_NET((struct vnet *) rock); 381 INIT_VNET_INET6((struct vnet *) rock); 382 struct radix_node_head *rnh = rock; 383 struct mtuex_arg arg; 384 struct timeval atv; 385 386 arg.rnh = rnh; 387 arg.nextstop = time_uptime + MTUTIMO_DEFAULT; 388 RADIX_NODE_HEAD_LOCK(rnh); 389 rnh->rnh_walktree(rnh, in6_mtuexpire, &arg); 390 RADIX_NODE_HEAD_UNLOCK(rnh); 391 392 atv.tv_usec = 0; 393 atv.tv_sec = arg.nextstop - time_uptime; 394 if (atv.tv_sec < 0) { 395 printf("invalid mtu expiration time on routing table\n"); 396 arg.nextstop = time_uptime + 30; /* last resort */ 397 atv.tv_sec = 30; 398 } 399 callout_reset(&V_rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock); 400 CURVNET_RESTORE(); 401 } 402 403 #if 0 404 void 405 in6_rtqdrain(void) 406 { 407 INIT_VNET_NET(curvnet); 408 struct radix_node_head *rnh = V_rt_tables[AF_INET6]; 409 struct rtqk_arg arg; 410 411 arg.found = arg.killed = 0; 412 arg.rnh = rnh; 413 arg.nextstop = 0; 414 arg.draining = 1; 415 arg.updating = 0; 416 RADIX_NODE_HEAD_LOCK(rnh); 417 rnh->rnh_walktree(rnh, in6_rtqkill, &arg); 418 RADIX_NODE_HEAD_UNLOCK(rnh); 419 } 420 #endif 421 422 /* 423 * Initialize our routing tree. 424 * XXX MRT When off == 0, we are being called from vfs_export.c 425 * so just set up their table and leave. (we know what the correct 426 * value should be so just use that).. FIX AFTER RELENG_7 is MFC'd 427 * see also comments in in_inithead() vfs_export.c and domain.h 428 */ 429 int 430 in6_inithead(void **head, int off) 431 { 432 INIT_VNET_INET6(curvnet); 433 struct radix_node_head *rnh; 434 435 if (!rn_inithead(head, offsetof(struct sockaddr_in6, sin6_addr) << 3)) 436 return 0; /* See above */ 437 438 if (off == 0) /* See above */ 439 return 1; /* only do the rest for the real thing */ 440 441 V_rtq_reallyold6 = 60*60; /* one hour is ``really old'' */ 442 V_rtq_minreallyold6 = 10; /* never automatically crank down to less */ 443 V_rtq_toomany6 = 128; /* 128 cached routes is ``too many'' */ 444 V_rtq_timeout6 = RTQ_TIMEOUT; 445 446 rnh = *head; 447 rnh->rnh_addaddr = in6_addroute; 448 rnh->rnh_matchaddr = in6_matroute; 449 callout_init(&V_rtq_timer6, CALLOUT_MPSAFE); 450 in6_rtqtimo(rnh); /* kick off timeout first time */ 451 callout_init(&V_rtq_mtutimer, CALLOUT_MPSAFE); 452 in6_mtutimo(rnh); /* kick off timeout first time */ 453 return 1; 454 } 455