in_rmx.c revision 295389
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: stable/10/sys/netinet/in_rmx.c 295389 2016-02-08 00:07:01Z bz $"); 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