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 <sys/param.h> 79 #include <sys/systm.h> 80 #include <sys/kernel.h> 81 #include <sys/lock.h> 82 #include <sys/sysctl.h> 83 #include <sys/queue.h> 84 #include <sys/socket.h> 85 #include <sys/socketvar.h> 86 #include <sys/mbuf.h> 87 #include <sys/rwlock.h> 88 #include <sys/syslog.h> 89 #include <sys/callout.h> 90 91 #include <net/if.h> 92 #include <net/route.h> 93 94 #include <netinet/in.h> 95 #include <netinet/ip_var.h> 96 #include <netinet/in_var.h> 97 98 #include <netinet/ip6.h> 99 #include <netinet6/ip6_var.h> 100 101 #include <netinet/icmp6.h> 102 #include <netinet6/nd6.h> 103 104 #include <netinet/tcp.h> 105 #include <netinet/tcp_seq.h> 106 #include <netinet/tcp_timer.h> 107 #include <netinet/tcp_var.h> 108 109 extern int in6_inithead(void **head, int off); 110 #ifdef VIMAGE 111 extern int in6_detachhead(void **head, int off); 112 #endif 113 114 #define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */ 115 116 /* 117 * Do what we need to do when inserting a route. 118 */ 119 static struct radix_node * 120 in6_addroute(void *v_arg, void *n_arg, struct radix_node_head *head, 121 struct radix_node *treenodes) 122 { 123 struct rtentry *rt = (struct rtentry *)treenodes; 124 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt); 125 struct radix_node *ret; 126 127 RADIX_NODE_HEAD_WLOCK_ASSERT(head); 128 if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 129 rt->rt_flags |= RTF_MULTICAST; 130 131 /* 132 * A little bit of help for both IPv6 output and input: 133 * For local addresses, we make sure that RTF_LOCAL is set, 134 * with the thought that this might one day be used to speed up 135 * ip_input(). 136 * 137 * We also mark routes to multicast addresses as such, because 138 * it's easy to do and might be useful (but this is much more 139 * dubious since it's so easy to inspect the address). (This 140 * is done above.) 141 * 142 * XXX 143 * should elaborate the code. 144 */ 145 if (rt->rt_flags & RTF_HOST) { 146 if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr) 147 ->sin6_addr, 148 &sin6->sin6_addr)) { 149 rt->rt_flags |= RTF_LOCAL; 150 } 151 } 152 153 if (!rt->rt_rmx.rmx_mtu && rt->rt_ifp) 154 rt->rt_rmx.rmx_mtu = IN6_LINKMTU(rt->rt_ifp); 155 156 ret = rn_addroute(v_arg, n_arg, head, treenodes); 157 if (ret == NULL) { 158 struct rtentry *rt2; 159 /* 160 * We are trying to add a net route, but can't. 161 * The following case should be allowed, so we'll make a 162 * special check for this: 163 * Two IPv6 addresses with the same prefix is assigned 164 * to a single interrface. 165 * # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1) 166 * # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2) 167 * In this case, (*1) and (*2) want to add the same 168 * net route entry, 3ffe:0501:: -> if0. 169 * This case should not raise an error. 170 */ 171 rt2 = in6_rtalloc1((struct sockaddr *)sin6, 0, RTF_RNH_LOCKED, 172 rt->rt_fibnum); 173 if (rt2) { 174 if (((rt2->rt_flags & (RTF_HOST|RTF_GATEWAY)) == 0) 175 && rt2->rt_gateway 176 && rt2->rt_gateway->sa_family == AF_LINK 177 && rt2->rt_ifp == rt->rt_ifp) { 178 ret = rt2->rt_nodes; 179 } 180 RTFREE_LOCKED(rt2); 181 } 182 } 183 return (ret); 184 } 185 186 /* 187 * This code is the inverse of in6_clsroute: on first reference, if we 188 * were managing the route, stop doing so and set the expiration timer 189 * back off again. 190 */ 191 static struct radix_node * 192 in6_matroute(void *v_arg, struct radix_node_head *head) 193 { 194 struct radix_node *rn = rn_match(v_arg, head); 195 struct rtentry *rt = (struct rtentry *)rn; 196 197 if (rt) { 198 RT_LOCK(rt); 199 if (rt->rt_flags & RTPRF_OURS) { 200 rt->rt_flags &= ~RTPRF_OURS; 201 rt->rt_rmx.rmx_expire = 0; 202 } 203 RT_UNLOCK(rt); 204 } 205 return rn; 206 } 207 208 SYSCTL_DECL(_net_inet6_ip6); 209 210 static VNET_DEFINE(int, rtq_reallyold6) = 60*60; 211 /* one hour is ``really old'' */ 212 #define V_rtq_reallyold6 VNET(rtq_reallyold6) 213 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTEXPIRE, rtexpire, CTLFLAG_RW, 214 &VNET_NAME(rtq_reallyold6) , 0, ""); 215 216 static VNET_DEFINE(int, rtq_minreallyold6) = 10; 217 /* never automatically crank down to less */ 218 #define V_rtq_minreallyold6 VNET(rtq_minreallyold6) 219 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTMINEXPIRE, rtminexpire, CTLFLAG_RW, 220 &VNET_NAME(rtq_minreallyold6) , 0, ""); 221 222 static VNET_DEFINE(int, rtq_toomany6) = 128; 223 /* 128 cached routes is ``too many'' */ 224 #define V_rtq_toomany6 VNET(rtq_toomany6) 225 SYSCTL_VNET_INT(_net_inet6_ip6, IPV6CTL_RTMAXCACHE, rtmaxcache, CTLFLAG_RW, 226 &VNET_NAME(rtq_toomany6) , 0, ""); 227 228 struct rtqk_arg { 229 struct radix_node_head *rnh; 230 int mode; 231 int updating; 232 int draining; 233 int killed; 234 int found; 235 time_t nextstop; 236 }; 237 238 /* 239 * Get rid of old routes. When draining, this deletes everything, even when 240 * the timeout is not expired yet. When updating, this makes sure that 241 * nothing has a timeout longer than the current value of rtq_reallyold6. 242 */ 243 static int 244 in6_rtqkill(struct radix_node *rn, void *rock) 245 { 246 struct rtqk_arg *ap = rock; 247 struct rtentry *rt = (struct rtentry *)rn; 248 int err; 249 250 RADIX_NODE_HEAD_WLOCK_ASSERT(ap->rnh); 251 252 if (rt->rt_flags & RTPRF_OURS) { 253 ap->found++; 254 255 if (ap->draining || rt->rt_rmx.rmx_expire <= time_uptime) { 256 if (rt->rt_refcnt > 0) 257 panic("rtqkill route really not free"); 258 259 err = in6_rtrequest(RTM_DELETE, 260 (struct sockaddr *)rt_key(rt), 261 rt->rt_gateway, rt_mask(rt), 262 rt->rt_flags|RTF_RNH_LOCKED, 0, 263 rt->rt_fibnum); 264 if (err) { 265 log(LOG_WARNING, "in6_rtqkill: error %d", err); 266 } else { 267 ap->killed++; 268 } 269 } else { 270 if (ap->updating 271 && (rt->rt_rmx.rmx_expire - time_uptime 272 > V_rtq_reallyold6)) { 273 rt->rt_rmx.rmx_expire = time_uptime 274 + V_rtq_reallyold6; 275 } 276 ap->nextstop = lmin(ap->nextstop, 277 rt->rt_rmx.rmx_expire); 278 } 279 } 280 281 return 0; 282 } 283 284 #define RTQ_TIMEOUT 60*10 /* run no less than once every ten minutes */ 285 static VNET_DEFINE(int, rtq_timeout6) = RTQ_TIMEOUT; 286 static VNET_DEFINE(struct callout, rtq_timer6); 287 288 #define V_rtq_timeout6 VNET(rtq_timeout6) 289 #define V_rtq_timer6 VNET(rtq_timer6) 290 291 static void 292 in6_rtqtimo_one(struct radix_node_head *rnh) 293 { 294 struct rtqk_arg arg; 295 static time_t last_adjusted_timeout = 0; 296 297 arg.found = arg.killed = 0; 298 arg.rnh = rnh; 299 arg.nextstop = time_uptime + V_rtq_timeout6; 300 arg.draining = arg.updating = 0; 301 RADIX_NODE_HEAD_LOCK(rnh); 302 rnh->rnh_walktree(rnh, in6_rtqkill, &arg); 303 RADIX_NODE_HEAD_UNLOCK(rnh); 304 305 /* 306 * Attempt to be somewhat dynamic about this: 307 * If there are ``too many'' routes sitting around taking up space, 308 * then crank down the timeout, and see if we can't make some more 309 * go away. However, we make sure that we will never adjust more 310 * than once in rtq_timeout6 seconds, to keep from cranking down too 311 * hard. 312 */ 313 if ((arg.found - arg.killed > V_rtq_toomany6) 314 && (time_uptime - last_adjusted_timeout >= V_rtq_timeout6) 315 && V_rtq_reallyold6 > V_rtq_minreallyold6) { 316 V_rtq_reallyold6 = 2*V_rtq_reallyold6 / 3; 317 if (V_rtq_reallyold6 < V_rtq_minreallyold6) { 318 V_rtq_reallyold6 = V_rtq_minreallyold6; 319 } 320 321 last_adjusted_timeout = time_uptime; 322 #ifdef DIAGNOSTIC 323 log(LOG_DEBUG, "in6_rtqtimo: adjusted rtq_reallyold6 to %d", 324 V_rtq_reallyold6); 325 #endif 326 arg.found = arg.killed = 0; 327 arg.updating = 1; 328 RADIX_NODE_HEAD_LOCK(rnh); 329 rnh->rnh_walktree(rnh, in6_rtqkill, &arg); 330 RADIX_NODE_HEAD_UNLOCK(rnh); 331 } 332 } 333 334 static void 335 in6_rtqtimo(void *rock) 336 { 337 CURVNET_SET_QUIET((struct vnet *) rock); 338 struct radix_node_head *rnh; 339 struct timeval atv; 340 u_int fibnum; 341 342 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) { 343 rnh = rt_tables_get_rnh(fibnum, AF_INET6); 344 if (rnh != NULL) 345 in6_rtqtimo_one(rnh); 346 } 347 348 atv.tv_usec = 0; 349 atv.tv_sec = V_rtq_timeout6; 350 callout_reset(&V_rtq_timer6, tvtohz(&atv), in6_rtqtimo, rock); 351 CURVNET_RESTORE(); 352 } 353 354 /* 355 * Age old PMTUs. 356 */ 357 struct mtuex_arg { 358 struct radix_node_head *rnh; 359 time_t nextstop; 360 }; 361 static VNET_DEFINE(struct callout, rtq_mtutimer); 362 #define V_rtq_mtutimer VNET(rtq_mtutimer) 363 364 static int 365 in6_mtuexpire(struct radix_node *rn, void *rock) 366 { 367 struct rtentry *rt = (struct rtentry *)rn; 368 struct mtuex_arg *ap = rock; 369 370 /* sanity */ 371 if (!rt) 372 panic("rt == NULL in in6_mtuexpire"); 373 374 if (rt->rt_rmx.rmx_expire && !(rt->rt_flags & RTF_PROBEMTU)) { 375 if (rt->rt_rmx.rmx_expire <= time_uptime) { 376 rt->rt_flags |= RTF_PROBEMTU; 377 } else { 378 ap->nextstop = lmin(ap->nextstop, 379 rt->rt_rmx.rmx_expire); 380 } 381 } 382 383 return 0; 384 } 385 386 #define MTUTIMO_DEFAULT (60*1) 387 388 static void 389 in6_mtutimo_one(struct radix_node_head *rnh) 390 { 391 struct mtuex_arg arg; 392 393 arg.rnh = rnh; 394 arg.nextstop = time_uptime + MTUTIMO_DEFAULT; 395 RADIX_NODE_HEAD_LOCK(rnh); 396 rnh->rnh_walktree(rnh, in6_mtuexpire, &arg); 397 RADIX_NODE_HEAD_UNLOCK(rnh); 398 } 399 400 static void 401 in6_mtutimo(void *rock) 402 { 403 CURVNET_SET_QUIET((struct vnet *) rock); 404 struct radix_node_head *rnh; 405 struct timeval atv; 406 u_int fibnum; 407 408 for (fibnum = 0; fibnum < rt_numfibs; fibnum++) { 409 rnh = rt_tables_get_rnh(fibnum, AF_INET6); 410 if (rnh != NULL) 411 in6_mtutimo_one(rnh); 412 } 413 414 atv.tv_sec = MTUTIMO_DEFAULT; 415 atv.tv_usec = 0; 416 callout_reset(&V_rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock); 417 CURVNET_RESTORE(); 418 } 419 420 /* 421 * Initialize our routing tree. 422 * XXX MRT When off == 0, we are being called from vfs_export.c 423 * so just set up their table and leave. (we know what the correct 424 * value should be so just use that).. FIX AFTER RELENG_7 is MFC'd 425 * see also comments in in_inithead() vfs_export.c and domain.h 426 */ 427 static VNET_DEFINE(int, _in6_rt_was_here); 428 #define V__in6_rt_was_here VNET(_in6_rt_was_here) 429 430 int 431 in6_inithead(void **head, int off) 432 { 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 rnh = *head; 442 rnh->rnh_addaddr = in6_addroute; 443 rnh->rnh_matchaddr = in6_matroute; 444 445 if (V__in6_rt_was_here == 0) { 446 callout_init(&V_rtq_timer6, CALLOUT_MPSAFE); 447 callout_init(&V_rtq_mtutimer, CALLOUT_MPSAFE); 448 in6_rtqtimo(curvnet); /* kick off timeout first time */ 449 in6_mtutimo(curvnet); /* kick off timeout first time */ 450 V__in6_rt_was_here = 1; 451 } 452 453 return 1; 454 } 455 456 #ifdef VIMAGE 457 int 458 in6_detachhead(void **head, int off) 459 { 460 461 callout_drain(&V_rtq_timer6); 462 callout_drain(&V_rtq_mtutimer); 463 return (1); 464 } 465 #endif 466 467 /* 468 * Extended API for IPv6 FIB support. 469 */ 470 void 471 in6_rtredirect(struct sockaddr *dst, struct sockaddr *gw, struct sockaddr *nm, 472 int flags, struct sockaddr *src, u_int fibnum) 473 { 474 475 rtredirect_fib(dst, gw, nm, flags, src, fibnum); 476 } 477 478 int 479 in6_rtrequest(int req, struct sockaddr *dst, struct sockaddr *gw, 480 struct sockaddr *mask, int flags, struct rtentry **ret_nrt, u_int fibnum) 481 { 482 483 return (rtrequest_fib(req, dst, gw, mask, flags, ret_nrt, fibnum)); 484 } 485 486 void 487 in6_rtalloc(struct route_in6 *ro, u_int fibnum) 488 { 489 490 rtalloc_ign_fib((struct route *)ro, 0ul, fibnum); 491 } 492 493 void 494 in6_rtalloc_ign(struct route_in6 *ro, u_long ignflags, u_int fibnum) 495 { 496 497 rtalloc_ign_fib((struct route *)ro, ignflags, fibnum); 498 } 499 500 struct rtentry * 501 in6_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum) 502 { 503 504 return (rtalloc1_fib(dst, report, ignflags, fibnum)); 505 } 506