Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/net/route.c
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1 /*- 2 * Copyright (c) 1980, 1986, 1991, 1993 3 * The Regents of the University of California. 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 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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 * @(#)route.c 8.3.1.1 (Berkeley) 2/23/95 30 * $FreeBSD$ 31 */ 32 /************************************************************************ 33 * Note: In this file a 'fib' is a "forwarding information base" * 34 * Which is the new name for an in kernel routing (next hop) table. * 35 ***********************************************************************/ 36 37 #include "opt_inet.h" 38 #include "opt_route.h" 39 #include "opt_mrouting.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/malloc.h> 44 #include <sys/mbuf.h> 45 #include <sys/socket.h> 46 #include <sys/sysctl.h> 47 #include <sys/sysproto.h> 48 #include <sys/proc.h> 49 #include <sys/domain.h> 50 #include <sys/kernel.h> 51 52 #include <net/if.h> 53 #include <net/route.h> 54 55 #include <netinet/in.h> 56 #include <netinet/ip_mroute.h> 57 58 #include <vm/uma.h> 59 60 #ifndef ROUTETABLES 61 #define RT_NUMFIBS 1 62 #define RT_MAXFIBS 1 63 #else 64 /* while we use 4 bits in the mbuf flags, 65 * we are limited to 16 66 */ 67 #define RT_MAXFIBS 16 68 #if ROUTETABLES > RT_MAXFIBS 69 #define RT_NUMFIBS RT_MAXFIBS 70 #error "ROUTETABLES defined too big" 71 #else 72 #if ROUTETABLES == 0 73 #define RT_NUMFIBS 1 74 #else 75 #define RT_NUMFIBS ROUTETABLES 76 #endif 77 #endif 78 #endif 79 80 u_int rt_numfibs = RT_NUMFIBS; 81 SYSCTL_INT(_net, OID_AUTO, fibs, CTLFLAG_RD, &rt_numfibs, 0, ""); 82 /* 83 * Allow the boot code to allow LESS than RT_MAXFIBS to be used. 84 * We can't do more because storage is statically allocated for now. 85 */ 86 TUNABLE_INT("net.fibs", &rt_numfibs); 87 88 /* 89 * By default add routes to all fibs for new interfaces. 90 * Once this is set to 0 then only allocate routes on interface 91 * changes for the FIB of the caller when adding a new set of addresses 92 * to an interface. XXX this is a shotgun aproach to a problem that needs 93 * a more fine grained solution.. that will come. 94 */ 95 u_int rt_add_addr_allfibs = 1; 96 SYSCTL_INT(_net, OID_AUTO, add_addr_allfibs, CTLFLAG_RW, 97 &rt_add_addr_allfibs, 0, ""); 98 TUNABLE_INT("net.add_addr_allfibs", &rt_add_addr_allfibs); 99 100 static struct rtstat rtstat; 101 102 /* by default only the first 'row' of tables will be accessed. */ 103 /* 104 * XXXMRT When we fix netstat, and do this differnetly, 105 * we can allocate this dynamically. As long as we are keeping 106 * things backwards compaitble we need to allocate this 107 * statically. 108 */ 109 struct radix_node_head *rt_tables[RT_MAXFIBS][AF_MAX+1]; 110 111 static int rttrash; /* routes not in table but not freed */ 112 113 static void rt_maskedcopy(struct sockaddr *, 114 struct sockaddr *, struct sockaddr *); 115 116 /* compare two sockaddr structures */ 117 #define sa_equal(a1, a2) (bcmp((a1), (a2), (a1)->sa_len) == 0) 118 119 /* 120 * Convert a 'struct radix_node *' to a 'struct rtentry *'. 121 * The operation can be done safely (in this code) because a 122 * 'struct rtentry' starts with two 'struct radix_node''s, the first 123 * one representing leaf nodes in the routing tree, which is 124 * what the code in radix.c passes us as a 'struct radix_node'. 125 * 126 * But because there are a lot of assumptions in this conversion, 127 * do not cast explicitly, but always use the macro below. 128 */ 129 #define RNTORT(p) ((struct rtentry *)(p)) 130 131 static uma_zone_t rtzone; /* Routing table UMA zone. */ 132 133 #if 0 134 /* default fib for tunnels to use */ 135 u_int tunnel_fib = 0; 136 SYSCTL_INT(_net, OID_AUTO, tunnelfib, CTLFLAG_RD, &tunnel_fib, 0, ""); 137 #endif 138 139 /* 140 * handler for net.my_fibnum 141 */ 142 static int 143 sysctl_my_fibnum(SYSCTL_HANDLER_ARGS) 144 { 145 int fibnum; 146 int error; 147 148 fibnum = curthread->td_proc->p_fibnum; 149 error = sysctl_handle_int(oidp, &fibnum, 0, req); 150 return (error); 151 } 152 153 SYSCTL_PROC(_net, OID_AUTO, my_fibnum, CTLTYPE_INT|CTLFLAG_RD, 154 NULL, 0, &sysctl_my_fibnum, "I", "default FIB of caller"); 155 156 static void 157 route_init(void) 158 { 159 int table; 160 struct domain *dom; 161 int fam; 162 163 /* whack teh tunable ints into line. */ 164 if (rt_numfibs > RT_MAXFIBS) 165 rt_numfibs = RT_MAXFIBS; 166 if (rt_numfibs == 0) 167 rt_numfibs = 1; 168 rtzone = uma_zcreate("rtentry", sizeof(struct rtentry), NULL, NULL, 169 NULL, NULL, UMA_ALIGN_PTR, 0); 170 rn_init(); /* initialize all zeroes, all ones, mask table */ 171 172 for (dom = domains; dom; dom = dom->dom_next) { 173 if (dom->dom_rtattach) { 174 for (table = 0; table < rt_numfibs; table++) { 175 if ( (fam = dom->dom_family) == AF_INET || 176 table == 0) { 177 /* for now only AF_INET has > 1 table */ 178 /* XXX MRT 179 * rtattach will be also called 180 * from vfs_export.c but the 181 * offset will be 0 182 * (only for AF_INET and AF_INET6 183 * which don't need it anyhow) 184 */ 185 dom->dom_rtattach( 186 (void **)&rt_tables[table][fam], 187 dom->dom_rtoffset); 188 } else { 189 break; 190 } 191 } 192 } 193 } 194 } 195 196 #ifndef _SYS_SYSPROTO_H_ 197 struct setfib_args { 198 int fibnum; 199 }; 200 #endif 201 int 202 setfib(struct thread *td, struct setfib_args *uap) 203 { 204 if (uap->fibnum < 0 || uap->fibnum >= rt_numfibs) 205 return EINVAL; 206 td->td_proc->p_fibnum = uap->fibnum; 207 return (0); 208 } 209 210 /* 211 * Packet routing routines. 212 */ 213 void 214 rtalloc(struct route *ro) 215 { 216 rtalloc_ign_fib(ro, 0UL, 0); 217 } 218 219 void 220 rtalloc_fib(struct route *ro, u_int fibnum) 221 { 222 rtalloc_ign_fib(ro, 0UL, fibnum); 223 } 224 225 void 226 rtalloc_ign(struct route *ro, u_long ignore) 227 { 228 struct rtentry *rt; 229 230 if ((rt = ro->ro_rt) != NULL) { 231 if (rt->rt_ifp != NULL && rt->rt_flags & RTF_UP) 232 return; 233 RTFREE(rt); 234 ro->ro_rt = NULL; 235 } 236 ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, ignore, 0); 237 if (ro->ro_rt) 238 RT_UNLOCK(ro->ro_rt); 239 } 240 241 void 242 rtalloc_ign_fib(struct route *ro, u_long ignore, u_int fibnum) 243 { 244 struct rtentry *rt; 245 246 if ((rt = ro->ro_rt) != NULL) { 247 if (rt->rt_ifp != NULL && rt->rt_flags & RTF_UP) 248 return; 249 RTFREE(rt); 250 ro->ro_rt = NULL; 251 } 252 ro->ro_rt = rtalloc1_fib(&ro->ro_dst, 1, ignore, fibnum); 253 if (ro->ro_rt) 254 RT_UNLOCK(ro->ro_rt); 255 } 256 257 /* 258 * Look up the route that matches the address given 259 * Or, at least try.. Create a cloned route if needed. 260 * 261 * The returned route, if any, is locked. 262 */ 263 struct rtentry * 264 rtalloc1(struct sockaddr *dst, int report, u_long ignflags) 265 { 266 return (rtalloc1_fib(dst, report, ignflags, 0)); 267 } 268 269 struct rtentry * 270 rtalloc1_fib(struct sockaddr *dst, int report, u_long ignflags, 271 u_int fibnum) 272 { 273 struct radix_node_head *rnh; 274 struct rtentry *rt; 275 struct radix_node *rn; 276 struct rtentry *newrt; 277 struct rt_addrinfo info; 278 u_long nflags; 279 int err = 0, msgtype = RTM_MISS; 280 281 KASSERT((fibnum < rt_numfibs), ("rtalloc1_fib: bad fibnum")); 282 if (dst->sa_family != AF_INET) /* Only INET supports > 1 fib now */ 283 fibnum = 0; 284 rnh = rt_tables[fibnum][dst->sa_family]; 285 newrt = NULL; 286 /* 287 * Look up the address in the table for that Address Family 288 */ 289 if (rnh == NULL) { 290 rtstat.rts_unreach++; 291 goto miss2; 292 } 293 RADIX_NODE_HEAD_LOCK(rnh); 294 if ((rn = rnh->rnh_matchaddr(dst, rnh)) && 295 (rn->rn_flags & RNF_ROOT) == 0) { 296 /* 297 * If we find it and it's not the root node, then 298 * get a reference on the rtentry associated. 299 */ 300 newrt = rt = RNTORT(rn); 301 nflags = rt->rt_flags & ~ignflags; 302 if (report && (nflags & RTF_CLONING)) { 303 /* 304 * We are apparently adding (report = 0 in delete). 305 * If it requires that it be cloned, do so. 306 * (This implies it wasn't a HOST route.) 307 */ 308 err = rtrequest_fib(RTM_RESOLVE, dst, NULL, 309 NULL, 0, &newrt, fibnum); 310 if (err) { 311 /* 312 * If the cloning didn't succeed, maybe 313 * what we have will do. Return that. 314 */ 315 newrt = rt; /* existing route */ 316 RT_LOCK(newrt); 317 RT_ADDREF(newrt); 318 goto miss; 319 } 320 KASSERT(newrt, ("no route and no error")); 321 RT_LOCK(newrt); 322 if (newrt->rt_flags & RTF_XRESOLVE) { 323 /* 324 * If the new route specifies it be 325 * externally resolved, then go do that. 326 */ 327 msgtype = RTM_RESOLVE; 328 goto miss; 329 } 330 /* Inform listeners of the new route. */ 331 bzero(&info, sizeof(info)); 332 info.rti_info[RTAX_DST] = rt_key(newrt); 333 info.rti_info[RTAX_NETMASK] = rt_mask(newrt); 334 info.rti_info[RTAX_GATEWAY] = newrt->rt_gateway; 335 if (newrt->rt_ifp != NULL) { 336 info.rti_info[RTAX_IFP] = 337 newrt->rt_ifp->if_addr->ifa_addr; 338 info.rti_info[RTAX_IFA] = newrt->rt_ifa->ifa_addr; 339 } 340 rt_missmsg(RTM_ADD, &info, newrt->rt_flags, 0); 341 } else { 342 KASSERT(rt == newrt, ("locking wrong route")); 343 RT_LOCK(newrt); 344 RT_ADDREF(newrt); 345 } 346 RADIX_NODE_HEAD_UNLOCK(rnh); 347 } else { 348 /* 349 * Either we hit the root or couldn't find any match, 350 * Which basically means 351 * "caint get there frm here" 352 */ 353 rtstat.rts_unreach++; 354 miss: 355 RADIX_NODE_HEAD_UNLOCK(rnh); 356 miss2: if (report) { 357 /* 358 * If required, report the failure to the supervising 359 * Authorities. 360 * For a delete, this is not an error. (report == 0) 361 */ 362 bzero(&info, sizeof(info)); 363 info.rti_info[RTAX_DST] = dst; 364 rt_missmsg(msgtype, &info, 0, err); 365 } 366 } 367 if (newrt) 368 RT_LOCK_ASSERT(newrt); 369 return (newrt); 370 } 371 372 /* 373 * Remove a reference count from an rtentry. 374 * If the count gets low enough, take it out of the routing table 375 */ 376 void 377 rtfree(struct rtentry *rt) 378 { 379 struct radix_node_head *rnh; 380 381 KASSERT(rt != NULL,("%s: NULL rt", __func__)); 382 rnh = rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family]; 383 KASSERT(rnh != NULL,("%s: NULL rnh", __func__)); 384 385 RT_LOCK_ASSERT(rt); 386 387 /* 388 * The callers should use RTFREE_LOCKED() or RTFREE(), so 389 * we should come here exactly with the last reference. 390 */ 391 RT_REMREF(rt); 392 if (rt->rt_refcnt > 0) { 393 printf("%s: %p has %lu refs\n", __func__, rt, rt->rt_refcnt); 394 goto done; 395 } 396 397 /* 398 * On last reference give the "close method" a chance 399 * to cleanup private state. This also permits (for 400 * IPv4 and IPv6) a chance to decide if the routing table 401 * entry should be purged immediately or at a later time. 402 * When an immediate purge is to happen the close routine 403 * typically calls rtexpunge which clears the RTF_UP flag 404 * on the entry so that the code below reclaims the storage. 405 */ 406 if (rt->rt_refcnt == 0 && rnh->rnh_close) 407 rnh->rnh_close((struct radix_node *)rt, rnh); 408 409 /* 410 * If we are no longer "up" (and ref == 0) 411 * then we can free the resources associated 412 * with the route. 413 */ 414 if ((rt->rt_flags & RTF_UP) == 0) { 415 if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT)) 416 panic("rtfree 2"); 417 /* 418 * the rtentry must have been removed from the routing table 419 * so it is represented in rttrash.. remove that now. 420 */ 421 rttrash--; 422 #ifdef DIAGNOSTIC 423 if (rt->rt_refcnt < 0) { 424 printf("rtfree: %p not freed (neg refs)\n", rt); 425 goto done; 426 } 427 #endif 428 /* 429 * release references on items we hold them on.. 430 * e.g other routes and ifaddrs. 431 */ 432 if (rt->rt_ifa) 433 IFAFREE(rt->rt_ifa); 434 rt->rt_parent = NULL; /* NB: no refcnt on parent */ 435 436 /* 437 * The key is separatly alloc'd so free it (see rt_setgate()). 438 * This also frees the gateway, as they are always malloc'd 439 * together. 440 */ 441 Free(rt_key(rt)); 442 443 /* 444 * and the rtentry itself of course 445 */ 446 RT_LOCK_DESTROY(rt); 447 uma_zfree(rtzone, rt); 448 return; 449 } 450 done: 451 RT_UNLOCK(rt); 452 } 453 454 455 /* 456 * Force a routing table entry to the specified 457 * destination to go through the given gateway. 458 * Normally called as a result of a routing redirect 459 * message from the network layer. 460 */ 461 void 462 rtredirect(struct sockaddr *dst, 463 struct sockaddr *gateway, 464 struct sockaddr *netmask, 465 int flags, 466 struct sockaddr *src) 467 { 468 469 rtredirect_fib(dst, gateway, netmask, flags, src, 0); 470 } 471 472 void 473 rtredirect_fib(struct sockaddr *dst, 474 struct sockaddr *gateway, 475 struct sockaddr *netmask, 476 int flags, 477 struct sockaddr *src, 478 u_int fibnum) 479 { 480 struct rtentry *rt, *rt0 = NULL; 481 int error = 0; 482 short *stat = NULL; 483 struct rt_addrinfo info; 484 struct ifaddr *ifa; 485 486 /* verify the gateway is directly reachable */ 487 if ((ifa = ifa_ifwithnet(gateway)) == NULL) { 488 error = ENETUNREACH; 489 goto out; 490 } 491 rt = rtalloc1_fib(dst, 0, 0UL, fibnum); /* NB: rt is locked */ 492 /* 493 * If the redirect isn't from our current router for this dst, 494 * it's either old or wrong. If it redirects us to ourselves, 495 * we have a routing loop, perhaps as a result of an interface 496 * going down recently. 497 */ 498 if (!(flags & RTF_DONE) && rt && 499 (!sa_equal(src, rt->rt_gateway) || rt->rt_ifa != ifa)) 500 error = EINVAL; 501 else if (ifa_ifwithaddr(gateway)) 502 error = EHOSTUNREACH; 503 if (error) 504 goto done; 505 /* 506 * Create a new entry if we just got back a wildcard entry 507 * or the the lookup failed. This is necessary for hosts 508 * which use routing redirects generated by smart gateways 509 * to dynamically build the routing tables. 510 */ 511 if (rt == NULL || (rt_mask(rt) && rt_mask(rt)->sa_len < 2)) 512 goto create; 513 /* 514 * Don't listen to the redirect if it's 515 * for a route to an interface. 516 */ 517 if (rt->rt_flags & RTF_GATEWAY) { 518 if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) { 519 /* 520 * Changing from route to net => route to host. 521 * Create new route, rather than smashing route to net. 522 */ 523 create: 524 rt0 = rt; 525 rt = NULL; 526 527 flags |= RTF_GATEWAY | RTF_DYNAMIC; 528 bzero((caddr_t)&info, sizeof(info)); 529 info.rti_info[RTAX_DST] = dst; 530 info.rti_info[RTAX_GATEWAY] = gateway; 531 info.rti_info[RTAX_NETMASK] = netmask; 532 info.rti_ifa = ifa; 533 info.rti_flags = flags; 534 error = rtrequest1_fib(RTM_ADD, &info, &rt, fibnum); 535 if (rt != NULL) { 536 RT_LOCK(rt); 537 EVENTHANDLER_INVOKE(route_redirect_event, rt0, rt, dst); 538 flags = rt->rt_flags; 539 } 540 if (rt0) 541 RTFREE_LOCKED(rt0); 542 543 stat = &rtstat.rts_dynamic; 544 } else { 545 struct rtentry *gwrt; 546 547 /* 548 * Smash the current notion of the gateway to 549 * this destination. Should check about netmask!!! 550 */ 551 rt->rt_flags |= RTF_MODIFIED; 552 flags |= RTF_MODIFIED; 553 stat = &rtstat.rts_newgateway; 554 /* 555 * add the key and gateway (in one malloc'd chunk). 556 */ 557 rt_setgate(rt, rt_key(rt), gateway); 558 gwrt = rtalloc1(gateway, 1, 0); 559 EVENTHANDLER_INVOKE(route_redirect_event, rt, gwrt, dst); 560 RTFREE_LOCKED(gwrt); 561 } 562 } else 563 error = EHOSTUNREACH; 564 done: 565 if (rt) 566 RTFREE_LOCKED(rt); 567 out: 568 if (error) 569 rtstat.rts_badredirect++; 570 else if (stat != NULL) 571 (*stat)++; 572 bzero((caddr_t)&info, sizeof(info)); 573 info.rti_info[RTAX_DST] = dst; 574 info.rti_info[RTAX_GATEWAY] = gateway; 575 info.rti_info[RTAX_NETMASK] = netmask; 576 info.rti_info[RTAX_AUTHOR] = src; 577 rt_missmsg(RTM_REDIRECT, &info, flags, error); 578 } 579 580 int 581 rtioctl(u_long req, caddr_t data) 582 { 583 return (rtioctl_fib(req, data, 0)); 584 } 585 586 /* 587 * Routing table ioctl interface. 588 */ 589 int 590 rtioctl_fib(u_long req, caddr_t data, u_int fibnum) 591 { 592 593 /* 594 * If more ioctl commands are added here, make sure the proper 595 * super-user checks are being performed because it is possible for 596 * prison-root to make it this far if raw sockets have been enabled 597 * in jails. 598 */ 599 #ifdef INET 600 /* Multicast goop, grrr... */ 601 return mrt_ioctl ? mrt_ioctl(req, data, fibnum) : EOPNOTSUPP; 602 #else /* INET */ 603 return ENXIO; 604 #endif /* INET */ 605 } 606 607 struct ifaddr * 608 ifa_ifwithroute(int flags, struct sockaddr *dst, struct sockaddr *gateway) 609 { 610 return (ifa_ifwithroute_fib(flags, dst, gateway, 0)); 611 } 612 613 struct ifaddr * 614 ifa_ifwithroute_fib(int flags, struct sockaddr *dst, struct sockaddr *gateway, 615 u_int fibnum) 616 { 617 register struct ifaddr *ifa; 618 int not_found = 0; 619 620 if ((flags & RTF_GATEWAY) == 0) { 621 /* 622 * If we are adding a route to an interface, 623 * and the interface is a pt to pt link 624 * we should search for the destination 625 * as our clue to the interface. Otherwise 626 * we can use the local address. 627 */ 628 ifa = NULL; 629 if (flags & RTF_HOST) 630 ifa = ifa_ifwithdstaddr(dst); 631 if (ifa == NULL) 632 ifa = ifa_ifwithaddr(gateway); 633 } else { 634 /* 635 * If we are adding a route to a remote net 636 * or host, the gateway may still be on the 637 * other end of a pt to pt link. 638 */ 639 ifa = ifa_ifwithdstaddr(gateway); 640 } 641 if (ifa == NULL) 642 ifa = ifa_ifwithnet(gateway); 643 if (ifa == NULL) { 644 struct rtentry *rt = rtalloc1_fib(gateway, 0, 0UL, fibnum); 645 if (rt == NULL) 646 return (NULL); 647 /* 648 * dismiss a gateway that is reachable only 649 * through the default router 650 */ 651 switch (gateway->sa_family) { 652 case AF_INET: 653 if (satosin(rt_key(rt))->sin_addr.s_addr == INADDR_ANY) 654 not_found = 1; 655 break; 656 case AF_INET6: 657 if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(rt_key(rt))->sin6_addr)) 658 not_found = 1; 659 break; 660 default: 661 break; 662 } 663 RT_REMREF(rt); 664 RT_UNLOCK(rt); 665 if (not_found) 666 return (NULL); 667 if ((ifa = rt->rt_ifa) == NULL) 668 return (NULL); 669 } 670 if (ifa->ifa_addr->sa_family != dst->sa_family) { 671 struct ifaddr *oifa = ifa; 672 ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp); 673 if (ifa == NULL) 674 ifa = oifa; 675 } 676 return (ifa); 677 } 678 679 static walktree_f_t rt_fixdelete; 680 static walktree_f_t rt_fixchange; 681 682 struct rtfc_arg { 683 struct rtentry *rt0; 684 struct radix_node_head *rnh; 685 }; 686 687 /* 688 * Do appropriate manipulations of a routing tree given 689 * all the bits of info needed 690 */ 691 int 692 rtrequest(int req, 693 struct sockaddr *dst, 694 struct sockaddr *gateway, 695 struct sockaddr *netmask, 696 int flags, 697 struct rtentry **ret_nrt) 698 { 699 return (rtrequest_fib(req, dst, gateway, netmask, flags, ret_nrt, 0)); 700 } 701 702 int 703 rtrequest_fib(int req, 704 struct sockaddr *dst, 705 struct sockaddr *gateway, 706 struct sockaddr *netmask, 707 int flags, 708 struct rtentry **ret_nrt, 709 u_int fibnum) 710 { 711 struct rt_addrinfo info; 712 713 if (dst->sa_len == 0) 714 return(EINVAL); 715 716 bzero((caddr_t)&info, sizeof(info)); 717 info.rti_flags = flags; 718 info.rti_info[RTAX_DST] = dst; 719 info.rti_info[RTAX_GATEWAY] = gateway; 720 info.rti_info[RTAX_NETMASK] = netmask; 721 return rtrequest1_fib(req, &info, ret_nrt, fibnum); 722 } 723 724 /* 725 * These (questionable) definitions of apparent local variables apply 726 * to the next two functions. XXXXXX!!! 727 */ 728 #define dst info->rti_info[RTAX_DST] 729 #define gateway info->rti_info[RTAX_GATEWAY] 730 #define netmask info->rti_info[RTAX_NETMASK] 731 #define ifaaddr info->rti_info[RTAX_IFA] 732 #define ifpaddr info->rti_info[RTAX_IFP] 733 #define flags info->rti_flags 734 735 int 736 rt_getifa(struct rt_addrinfo *info) 737 { 738 return (rt_getifa_fib(info, 0)); 739 } 740 741 int 742 rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum) 743 { 744 struct ifaddr *ifa; 745 int error = 0; 746 747 /* 748 * ifp may be specified by sockaddr_dl 749 * when protocol address is ambiguous. 750 */ 751 if (info->rti_ifp == NULL && ifpaddr != NULL && 752 ifpaddr->sa_family == AF_LINK && 753 (ifa = ifa_ifwithnet(ifpaddr)) != NULL) 754 info->rti_ifp = ifa->ifa_ifp; 755 if (info->rti_ifa == NULL && ifaaddr != NULL) 756 info->rti_ifa = ifa_ifwithaddr(ifaaddr); 757 if (info->rti_ifa == NULL) { 758 struct sockaddr *sa; 759 760 sa = ifaaddr != NULL ? ifaaddr : 761 (gateway != NULL ? gateway : dst); 762 if (sa != NULL && info->rti_ifp != NULL) 763 info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp); 764 else if (dst != NULL && gateway != NULL) 765 info->rti_ifa = ifa_ifwithroute_fib(flags, dst, gateway, 766 fibnum); 767 else if (sa != NULL) 768 info->rti_ifa = ifa_ifwithroute_fib(flags, sa, sa, 769 fibnum); 770 } 771 if ((ifa = info->rti_ifa) != NULL) { 772 if (info->rti_ifp == NULL) 773 info->rti_ifp = ifa->ifa_ifp; 774 } else 775 error = ENETUNREACH; 776 return (error); 777 } 778 779 /* 780 * Expunges references to a route that's about to be reclaimed. 781 * The route must be locked. 782 */ 783 int 784 rtexpunge(struct rtentry *rt) 785 { 786 struct radix_node *rn; 787 struct radix_node_head *rnh; 788 struct ifaddr *ifa; 789 int error = 0; 790 791 RT_LOCK_ASSERT(rt); 792 #if 0 793 /* 794 * We cannot assume anything about the reference count 795 * because protocols call us in many situations; often 796 * before unwinding references to the table entry. 797 */ 798 KASSERT(rt->rt_refcnt <= 1, ("bogus refcnt %ld", rt->rt_refcnt)); 799 #endif 800 /* 801 * Find the correct routing tree to use for this Address Family 802 */ 803 rnh = rt_tables[rt->rt_fibnum][rt_key(rt)->sa_family]; 804 if (rnh == NULL) 805 return (EAFNOSUPPORT); 806 807 RADIX_NODE_HEAD_LOCK(rnh); 808 809 /* 810 * Remove the item from the tree; it should be there, 811 * but when callers invoke us blindly it may not (sigh). 812 */ 813 rn = rnh->rnh_deladdr(rt_key(rt), rt_mask(rt), rnh); 814 if (rn == NULL) { 815 error = ESRCH; 816 goto bad; 817 } 818 KASSERT((rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)) == 0, 819 ("unexpected flags 0x%x", rn->rn_flags)); 820 KASSERT(rt == RNTORT(rn), 821 ("lookup mismatch, rt %p rn %p", rt, rn)); 822 823 rt->rt_flags &= ~RTF_UP; 824 825 /* 826 * Now search what's left of the subtree for any cloned 827 * routes which might have been formed from this node. 828 */ 829 if ((rt->rt_flags & RTF_CLONING) && rt_mask(rt)) 830 rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), 831 rt_fixdelete, rt); 832 833 /* 834 * Remove any external references we may have. 835 * This might result in another rtentry being freed if 836 * we held its last reference. 837 */ 838 if (rt->rt_gwroute) { 839 RTFREE(rt->rt_gwroute); 840 rt->rt_gwroute = NULL; 841 } 842 843 /* 844 * Give the protocol a chance to keep things in sync. 845 */ 846 if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest) { 847 struct rt_addrinfo info; 848 849 bzero((caddr_t)&info, sizeof(info)); 850 info.rti_flags = rt->rt_flags; 851 info.rti_info[RTAX_DST] = rt_key(rt); 852 info.rti_info[RTAX_GATEWAY] = rt->rt_gateway; 853 info.rti_info[RTAX_NETMASK] = rt_mask(rt); 854 ifa->ifa_rtrequest(RTM_DELETE, rt, &info); 855 } 856 857 /* 858 * one more rtentry floating around that is not 859 * linked to the routing table. 860 */ 861 rttrash++; 862 bad: 863 RADIX_NODE_HEAD_UNLOCK(rnh); 864 return (error); 865 } 866 867 int 868 rtrequest1(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt) 869 { 870 return (rtrequest1_fib(req, info, ret_nrt, 0)); 871 } 872 873 int 874 rtrequest1_fib(int req, struct rt_addrinfo *info, struct rtentry **ret_nrt, 875 u_int fibnum) 876 { 877 int error = 0; 878 register struct rtentry *rt; 879 register struct radix_node *rn; 880 register struct radix_node_head *rnh; 881 struct ifaddr *ifa; 882 struct sockaddr *ndst; 883 #define senderr(x) { error = x ; goto bad; } 884 885 KASSERT((fibnum < rt_numfibs), ("rtrequest1_fib: bad fibnum")); 886 if (dst->sa_family != AF_INET) /* Only INET supports > 1 fib now */ 887 fibnum = 0; 888 /* 889 * Find the correct routing tree to use for this Address Family 890 */ 891 rnh = rt_tables[fibnum][dst->sa_family]; 892 if (rnh == NULL) 893 return (EAFNOSUPPORT); 894 RADIX_NODE_HEAD_LOCK(rnh); 895 /* 896 * If we are adding a host route then we don't want to put 897 * a netmask in the tree, nor do we want to clone it. 898 */ 899 if (flags & RTF_HOST) { 900 netmask = NULL; 901 flags &= ~RTF_CLONING; 902 } 903 switch (req) { 904 case RTM_DELETE: 905 /* 906 * Remove the item from the tree and return it. 907 * Complain if it is not there and do no more processing. 908 */ 909 rn = rnh->rnh_deladdr(dst, netmask, rnh); 910 if (rn == NULL) 911 senderr(ESRCH); 912 if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)) 913 panic ("rtrequest delete"); 914 rt = RNTORT(rn); 915 RT_LOCK(rt); 916 RT_ADDREF(rt); 917 rt->rt_flags &= ~RTF_UP; 918 919 /* 920 * Now search what's left of the subtree for any cloned 921 * routes which might have been formed from this node. 922 */ 923 if ((rt->rt_flags & RTF_CLONING) && 924 rt_mask(rt)) { 925 rnh->rnh_walktree_from(rnh, dst, rt_mask(rt), 926 rt_fixdelete, rt); 927 } 928 929 /* 930 * Remove any external references we may have. 931 * This might result in another rtentry being freed if 932 * we held its last reference. 933 */ 934 if (rt->rt_gwroute) { 935 RTFREE(rt->rt_gwroute); 936 rt->rt_gwroute = NULL; 937 } 938 939 /* 940 * give the protocol a chance to keep things in sync. 941 */ 942 if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest) 943 ifa->ifa_rtrequest(RTM_DELETE, rt, info); 944 945 /* 946 * One more rtentry floating around that is not 947 * linked to the routing table. rttrash will be decremented 948 * when RTFREE(rt) is eventually called. 949 */ 950 rttrash++; 951 952 /* 953 * If the caller wants it, then it can have it, 954 * but it's up to it to free the rtentry as we won't be 955 * doing it. 956 */ 957 if (ret_nrt) { 958 *ret_nrt = rt; 959 RT_UNLOCK(rt); 960 } else 961 RTFREE_LOCKED(rt); 962 break; 963 964 case RTM_RESOLVE: 965 if (ret_nrt == NULL || (rt = *ret_nrt) == NULL) 966 senderr(EINVAL); 967 ifa = rt->rt_ifa; 968 /* XXX locking? */ 969 flags = rt->rt_flags & 970 ~(RTF_CLONING | RTF_STATIC); 971 flags |= RTF_WASCLONED; 972 gateway = rt->rt_gateway; 973 if ((netmask = rt->rt_genmask) == NULL) 974 flags |= RTF_HOST; 975 goto makeroute; 976 977 case RTM_ADD: 978 if ((flags & RTF_GATEWAY) && !gateway) 979 senderr(EINVAL); 980 if (dst && gateway && (dst->sa_family != gateway->sa_family) && 981 (gateway->sa_family != AF_UNSPEC) && (gateway->sa_family != AF_LINK)) 982 senderr(EINVAL); 983 984 if (info->rti_ifa == NULL && (error = rt_getifa_fib(info, fibnum))) 985 senderr(error); 986 ifa = info->rti_ifa; 987 988 makeroute: 989 rt = uma_zalloc(rtzone, M_NOWAIT | M_ZERO); 990 if (rt == NULL) 991 senderr(ENOBUFS); 992 RT_LOCK_INIT(rt); 993 rt->rt_flags = RTF_UP | flags; 994 rt->rt_fibnum = fibnum; 995 /* 996 * Add the gateway. Possibly re-malloc-ing the storage for it 997 * also add the rt_gwroute if possible. 998 */ 999 RT_LOCK(rt); 1000 if ((error = rt_setgate(rt, dst, gateway)) != 0) { 1001 RT_LOCK_DESTROY(rt); 1002 uma_zfree(rtzone, rt); 1003 senderr(error); 1004 } 1005 1006 /* 1007 * point to the (possibly newly malloc'd) dest address. 1008 */ 1009 ndst = (struct sockaddr *)rt_key(rt); 1010 1011 /* 1012 * make sure it contains the value we want (masked if needed). 1013 */ 1014 if (netmask) { 1015 rt_maskedcopy(dst, ndst, netmask); 1016 } else 1017 bcopy(dst, ndst, dst->sa_len); 1018 1019 /* 1020 * Note that we now have a reference to the ifa. 1021 * This moved from below so that rnh->rnh_addaddr() can 1022 * examine the ifa and ifa->ifa_ifp if it so desires. 1023 */ 1024 IFAREF(ifa); 1025 rt->rt_ifa = ifa; 1026 rt->rt_ifp = ifa->ifa_ifp; 1027 1028 /* XXX mtu manipulation will be done in rnh_addaddr -- itojun */ 1029 rn = rnh->rnh_addaddr(ndst, netmask, rnh, rt->rt_nodes); 1030 if (rn == NULL) { 1031 struct rtentry *rt2; 1032 /* 1033 * Uh-oh, we already have one of these in the tree. 1034 * We do a special hack: if the route that's already 1035 * there was generated by the cloning mechanism 1036 * then we just blow it away and retry the insertion 1037 * of the new one. 1038 */ 1039 rt2 = rtalloc1_fib(dst, 0, 0, fibnum); 1040 if (rt2 && rt2->rt_parent) { 1041 rtexpunge(rt2); 1042 RT_UNLOCK(rt2); 1043 rn = rnh->rnh_addaddr(ndst, netmask, 1044 rnh, rt->rt_nodes); 1045 } else if (rt2) { 1046 /* undo the extra ref we got */ 1047 RTFREE_LOCKED(rt2); 1048 } 1049 } 1050 1051 /* 1052 * If it still failed to go into the tree, 1053 * then un-make it (this should be a function) 1054 */ 1055 if (rn == NULL) { 1056 if (rt->rt_gwroute) 1057 RTFREE(rt->rt_gwroute); 1058 if (rt->rt_ifa) 1059 IFAFREE(rt->rt_ifa); 1060 Free(rt_key(rt)); 1061 RT_LOCK_DESTROY(rt); 1062 uma_zfree(rtzone, rt); 1063 senderr(EEXIST); 1064 } 1065 1066 rt->rt_parent = NULL; 1067 1068 /* 1069 * If we got here from RESOLVE, then we are cloning 1070 * so clone the rest, and note that we 1071 * are a clone (and increment the parent's references) 1072 */ 1073 if (req == RTM_RESOLVE) { 1074 KASSERT(ret_nrt && *ret_nrt, 1075 ("no route to clone from")); 1076 rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */ 1077 rt->rt_rmx.rmx_pksent = 0; /* reset packet counter */ 1078 if ((*ret_nrt)->rt_flags & RTF_CLONING) { 1079 /* 1080 * NB: We do not bump the refcnt on the parent 1081 * entry under the assumption that it will 1082 * remain so long as we do. This is 1083 * important when deleting the parent route 1084 * as this operation requires traversing 1085 * the tree to delete all clones and futzing 1086 * with refcnts requires us to double-lock 1087 * parent through this back reference. 1088 */ 1089 rt->rt_parent = *ret_nrt; 1090 } 1091 } 1092 1093 /* 1094 * If this protocol has something to add to this then 1095 * allow it to do that as well. 1096 */ 1097 if (ifa->ifa_rtrequest) 1098 ifa->ifa_rtrequest(req, rt, info); 1099 1100 /* 1101 * We repeat the same procedure from rt_setgate() here because 1102 * it doesn't fire when we call it there because the node 1103 * hasn't been added to the tree yet. 1104 */ 1105 if (req == RTM_ADD && 1106 !(rt->rt_flags & RTF_HOST) && rt_mask(rt) != NULL) { 1107 struct rtfc_arg arg; 1108 arg.rnh = rnh; 1109 arg.rt0 = rt; 1110 rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), 1111 rt_fixchange, &arg); 1112 } 1113 1114 /* 1115 * actually return a resultant rtentry and 1116 * give the caller a single reference. 1117 */ 1118 if (ret_nrt) { 1119 *ret_nrt = rt; 1120 RT_ADDREF(rt); 1121 } 1122 RT_UNLOCK(rt); 1123 break; 1124 default: 1125 error = EOPNOTSUPP; 1126 } 1127 bad: 1128 RADIX_NODE_HEAD_UNLOCK(rnh); 1129 return (error); 1130 #undef senderr 1131 } 1132 1133 #undef dst 1134 #undef gateway 1135 #undef netmask 1136 #undef ifaaddr 1137 #undef ifpaddr 1138 #undef flags 1139 1140 /* 1141 * Called from rtrequest(RTM_DELETE, ...) to fix up the route's ``family'' 1142 * (i.e., the routes related to it by the operation of cloning). This 1143 * routine is iterated over all potential former-child-routes by way of 1144 * rnh->rnh_walktree_from() above, and those that actually are children of 1145 * the late parent (passed in as VP here) are themselves deleted. 1146 */ 1147 static int 1148 rt_fixdelete(struct radix_node *rn, void *vp) 1149 { 1150 struct rtentry *rt = RNTORT(rn); 1151 struct rtentry *rt0 = vp; 1152 1153 if (rt->rt_parent == rt0 && 1154 !(rt->rt_flags & (RTF_PINNED | RTF_CLONING))) { 1155 return rtrequest_fib(RTM_DELETE, rt_key(rt), NULL, rt_mask(rt), 1156 rt->rt_flags, NULL, rt->rt_fibnum); 1157 } 1158 return 0; 1159 } 1160 1161 /* 1162 * This routine is called from rt_setgate() to do the analogous thing for 1163 * adds and changes. There is the added complication in this case of a 1164 * middle insert; i.e., insertion of a new network route between an older 1165 * network route and (cloned) host routes. For this reason, a simple check 1166 * of rt->rt_parent is insufficient; each candidate route must be tested 1167 * against the (mask, value) of the new route (passed as before in vp) 1168 * to see if the new route matches it. 1169 * 1170 * XXX - it may be possible to do fixdelete() for changes and reserve this 1171 * routine just for adds. I'm not sure why I thought it was necessary to do 1172 * changes this way. 1173 */ 1174 1175 static int 1176 rt_fixchange(struct radix_node *rn, void *vp) 1177 { 1178 struct rtentry *rt = RNTORT(rn); 1179 struct rtfc_arg *ap = vp; 1180 struct rtentry *rt0 = ap->rt0; 1181 struct radix_node_head *rnh = ap->rnh; 1182 u_char *xk1, *xm1, *xk2, *xmp; 1183 int i, len, mlen; 1184 1185 /* make sure we have a parent, and route is not pinned or cloning */ 1186 if (!rt->rt_parent || 1187 (rt->rt_flags & (RTF_PINNED | RTF_CLONING))) 1188 return 0; 1189 1190 if (rt->rt_parent == rt0) /* parent match */ 1191 goto delete_rt; 1192 /* 1193 * There probably is a function somewhere which does this... 1194 * if not, there should be. 1195 */ 1196 len = imin(rt_key(rt0)->sa_len, rt_key(rt)->sa_len); 1197 1198 xk1 = (u_char *)rt_key(rt0); 1199 xm1 = (u_char *)rt_mask(rt0); 1200 xk2 = (u_char *)rt_key(rt); 1201 1202 /* avoid applying a less specific route */ 1203 xmp = (u_char *)rt_mask(rt->rt_parent); 1204 mlen = rt_key(rt->rt_parent)->sa_len; 1205 if (mlen > rt_key(rt0)->sa_len) /* less specific route */ 1206 return 0; 1207 for (i = rnh->rnh_treetop->rn_offset; i < mlen; i++) 1208 if ((xmp[i] & ~(xmp[i] ^ xm1[i])) != xmp[i]) 1209 return 0; /* less specific route */ 1210 1211 for (i = rnh->rnh_treetop->rn_offset; i < len; i++) 1212 if ((xk2[i] & xm1[i]) != xk1[i]) 1213 return 0; /* no match */ 1214 1215 /* 1216 * OK, this node is a clone, and matches the node currently being 1217 * changed/added under the node's mask. So, get rid of it. 1218 */ 1219 delete_rt: 1220 return rtrequest_fib(RTM_DELETE, rt_key(rt), NULL, 1221 rt_mask(rt), rt->rt_flags, NULL, rt->rt_fibnum); 1222 } 1223 1224 int 1225 rt_setgate(struct rtentry *rt, struct sockaddr *dst, struct sockaddr *gate) 1226 { 1227 /* XXX dst may be overwritten, can we move this to below */ 1228 struct radix_node_head *rnh = rt_tables[rt->rt_fibnum][dst->sa_family]; 1229 int dlen = SA_SIZE(dst), glen = SA_SIZE(gate); 1230 1231 again: 1232 RT_LOCK_ASSERT(rt); 1233 1234 /* 1235 * A host route with the destination equal to the gateway 1236 * will interfere with keeping LLINFO in the routing 1237 * table, so disallow it. 1238 */ 1239 if (((rt->rt_flags & (RTF_HOST|RTF_GATEWAY|RTF_LLINFO)) == 1240 (RTF_HOST|RTF_GATEWAY)) && 1241 dst->sa_len == gate->sa_len && 1242 bcmp(dst, gate, dst->sa_len) == 0) { 1243 /* 1244 * The route might already exist if this is an RTM_CHANGE 1245 * or a routing redirect, so try to delete it. 1246 */ 1247 if (rt_key(rt)) 1248 rtexpunge(rt); 1249 return EADDRNOTAVAIL; 1250 } 1251 1252 /* 1253 * Cloning loop avoidance in case of bad configuration. 1254 */ 1255 if (rt->rt_flags & RTF_GATEWAY) { 1256 struct rtentry *gwrt; 1257 1258 RT_UNLOCK(rt); /* XXX workaround LOR */ 1259 gwrt = rtalloc1_fib(gate, 1, 0, rt->rt_fibnum); 1260 if (gwrt == rt) { 1261 RT_REMREF(rt); 1262 return (EADDRINUSE); /* failure */ 1263 } 1264 /* 1265 * Try to reacquire the lock on rt, and if it fails, 1266 * clean state and restart from scratch. 1267 */ 1268 if (!RT_TRYLOCK(rt)) { 1269 RTFREE_LOCKED(gwrt); 1270 RT_LOCK(rt); 1271 goto again; 1272 } 1273 /* 1274 * If there is already a gwroute, then drop it. If we 1275 * are asked to replace route with itself, then do 1276 * not leak its refcounter. 1277 */ 1278 if (rt->rt_gwroute != NULL) { 1279 if (rt->rt_gwroute == gwrt) { 1280 RT_REMREF(rt->rt_gwroute); 1281 } else 1282 RTFREE(rt->rt_gwroute); 1283 } 1284 1285 if ((rt->rt_gwroute = gwrt) != NULL) 1286 RT_UNLOCK(rt->rt_gwroute); 1287 } 1288 1289 /* 1290 * Prepare to store the gateway in rt->rt_gateway. 1291 * Both dst and gateway are stored one after the other in the same 1292 * malloc'd chunk. If we have room, we can reuse the old buffer, 1293 * rt_gateway already points to the right place. 1294 * Otherwise, malloc a new block and update the 'dst' address. 1295 */ 1296 if (rt->rt_gateway == NULL || glen > SA_SIZE(rt->rt_gateway)) { 1297 caddr_t new; 1298 1299 R_Malloc(new, caddr_t, dlen + glen); 1300 if (new == NULL) 1301 return ENOBUFS; 1302 /* 1303 * XXX note, we copy from *dst and not *rt_key(rt) because 1304 * rt_setgate() can be called to initialize a newly 1305 * allocated route entry, in which case rt_key(rt) == NULL 1306 * (and also rt->rt_gateway == NULL). 1307 * Free()/free() handle a NULL argument just fine. 1308 */ 1309 bcopy(dst, new, dlen); 1310 Free(rt_key(rt)); /* free old block, if any */ 1311 rt_key(rt) = (struct sockaddr *)new; 1312 rt->rt_gateway = (struct sockaddr *)(new + dlen); 1313 } 1314 1315 /* 1316 * Copy the new gateway value into the memory chunk. 1317 */ 1318 bcopy(gate, rt->rt_gateway, glen); 1319 1320 /* 1321 * This isn't going to do anything useful for host routes, so 1322 * don't bother. Also make sure we have a reasonable mask 1323 * (we don't yet have one during adds). 1324 */ 1325 if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) { 1326 struct rtfc_arg arg; 1327 1328 arg.rnh = rnh; 1329 arg.rt0 = rt; 1330 RT_UNLOCK(rt); /* XXX workaround LOR */ 1331 RADIX_NODE_HEAD_LOCK(rnh); 1332 RT_LOCK(rt); 1333 rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), 1334 rt_fixchange, &arg); 1335 RADIX_NODE_HEAD_UNLOCK(rnh); 1336 } 1337 1338 return 0; 1339 } 1340 1341 static void 1342 rt_maskedcopy(struct sockaddr *src, struct sockaddr *dst, struct sockaddr *netmask) 1343 { 1344 register u_char *cp1 = (u_char *)src; 1345 register u_char *cp2 = (u_char *)dst; 1346 register u_char *cp3 = (u_char *)netmask; 1347 u_char *cplim = cp2 + *cp3; 1348 u_char *cplim2 = cp2 + *cp1; 1349 1350 *cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */ 1351 cp3 += 2; 1352 if (cplim > cplim2) 1353 cplim = cplim2; 1354 while (cp2 < cplim) 1355 *cp2++ = *cp1++ & *cp3++; 1356 if (cp2 < cplim2) 1357 bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2)); 1358 } 1359 1360 /* 1361 * Set up a routing table entry, normally 1362 * for an interface. 1363 */ 1364 #define _SOCKADDR_TMPSIZE 128 /* Not too big.. kernel stack size is limited */ 1365 static inline int 1366 rtinit1(struct ifaddr *ifa, int cmd, int flags, int fibnum) 1367 { 1368 struct sockaddr *dst; 1369 struct sockaddr *netmask; 1370 struct rtentry *rt = NULL; 1371 struct rt_addrinfo info; 1372 int error = 0; 1373 int startfib, endfib; 1374 char tempbuf[_SOCKADDR_TMPSIZE]; 1375 int didwork = 0; 1376 int a_failure = 0; 1377 1378 if (flags & RTF_HOST) { 1379 dst = ifa->ifa_dstaddr; 1380 netmask = NULL; 1381 } else { 1382 dst = ifa->ifa_addr; 1383 netmask = ifa->ifa_netmask; 1384 } 1385 if ( dst->sa_family != AF_INET) 1386 fibnum = 0; 1387 if (fibnum == -1) { 1388 if (rt_add_addr_allfibs == 0 && cmd == (int)RTM_ADD) { 1389 startfib = endfib = curthread->td_proc->p_fibnum; 1390 } else { 1391 startfib = 0; 1392 endfib = rt_numfibs - 1; 1393 } 1394 } else { 1395 KASSERT((fibnum < rt_numfibs), ("rtinit1: bad fibnum")); 1396 startfib = fibnum; 1397 endfib = fibnum; 1398 } 1399 if (dst->sa_len == 0) 1400 return(EINVAL); 1401 1402 /* 1403 * If it's a delete, check that if it exists, 1404 * it's on the correct interface or we might scrub 1405 * a route to another ifa which would 1406 * be confusing at best and possibly worse. 1407 */ 1408 if (cmd == RTM_DELETE) { 1409 /* 1410 * It's a delete, so it should already exist.. 1411 * If it's a net, mask off the host bits 1412 * (Assuming we have a mask) 1413 * XXX this is kinda inet specific.. 1414 */ 1415 if (netmask != NULL) { 1416 rt_maskedcopy(dst, (struct sockaddr *)tempbuf, netmask); 1417 dst = (struct sockaddr *)tempbuf; 1418 } 1419 } 1420 /* 1421 * Now go through all the requested tables (fibs) and do the 1422 * requested action. Realistically, this will either be fib 0 1423 * for protocols that don't do multiple tables or all the 1424 * tables for those that do. XXX For this version only AF_INET. 1425 * When that changes code should be refactored to protocol 1426 * independent parts and protocol dependent parts. 1427 */ 1428 for ( fibnum = startfib; fibnum <= endfib; fibnum++) { 1429 if (cmd == RTM_DELETE) { 1430 struct radix_node_head *rnh; 1431 struct radix_node *rn; 1432 /* 1433 * Look up an rtentry that is in the routing tree and 1434 * contains the correct info. 1435 */ 1436 if ((rnh = rt_tables[fibnum][dst->sa_family]) == NULL) 1437 /* this table doesn't exist but others might */ 1438 continue; 1439 RADIX_NODE_HEAD_LOCK(rnh); 1440 rn = rnh->rnh_lookup(dst, netmask, rnh); 1441 error = (rn == NULL || 1442 (rn->rn_flags & RNF_ROOT) || 1443 RNTORT(rn)->rt_ifa != ifa || 1444 !sa_equal((struct sockaddr *)rn->rn_key, dst)); 1445 RADIX_NODE_HEAD_UNLOCK(rnh); 1446 if (error) { 1447 /* this is only an error if bad on ALL tables */ 1448 continue; 1449 } 1450 } 1451 /* 1452 * Do the actual request 1453 */ 1454 bzero((caddr_t)&info, sizeof(info)); 1455 info.rti_ifa = ifa; 1456 info.rti_flags = flags | ifa->ifa_flags; 1457 info.rti_info[RTAX_DST] = dst; 1458 info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr; 1459 info.rti_info[RTAX_NETMASK] = netmask; 1460 error = rtrequest1_fib(cmd, &info, &rt, fibnum); 1461 if (error == 0 && rt != NULL) { 1462 /* 1463 * notify any listening routing agents of the change 1464 */ 1465 RT_LOCK(rt); 1466 rt_newaddrmsg(cmd, ifa, error, rt); 1467 if (cmd == RTM_DELETE) { 1468 /* 1469 * If we are deleting, and we found an entry, then 1470 * it's been removed from the tree.. now throw it away. 1471 */ 1472 RTFREE_LOCKED(rt); 1473 } else { 1474 if (cmd == RTM_ADD) { 1475 /* 1476 * We just wanted to add it.. we don't actually 1477 * need a reference. 1478 */ 1479 RT_REMREF(rt); 1480 } 1481 RT_UNLOCK(rt); 1482 } 1483 didwork = 1; 1484 } 1485 if (error) 1486 a_failure = error; 1487 } 1488 if (cmd == RTM_DELETE) { 1489 if (didwork) { 1490 error = 0; 1491 } else { 1492 /* we only give an error if it wasn't in any table */ 1493 error = ((flags & RTF_HOST) ? 1494 EHOSTUNREACH : ENETUNREACH); 1495 } 1496 } else { 1497 if (a_failure) { 1498 /* return an error if any of them failed */ 1499 error = a_failure; 1500 } 1501 } 1502 return (error); 1503 } 1504 1505 /* special one for inet internal use. may not use. */ 1506 int 1507 rtinit_fib(struct ifaddr *ifa, int cmd, int flags) 1508 { 1509 return (rtinit1(ifa, cmd, flags, -1)); 1510 } 1511 1512 /* 1513 * Set up a routing table entry, normally 1514 * for an interface. 1515 */ 1516 int 1517 rtinit(struct ifaddr *ifa, int cmd, int flags) 1518 { 1519 struct sockaddr *dst; 1520 int fib = 0; 1521 1522 if (flags & RTF_HOST) { 1523 dst = ifa->ifa_dstaddr; 1524 } else { 1525 dst = ifa->ifa_addr; 1526 } 1527 1528 if (dst->sa_family == AF_INET) 1529 fib = -1; 1530 return (rtinit1(ifa, cmd, flags, fib)); 1531 } 1532 1533 /* 1534 * rt_check() is invoked on each layer 2 output path, prior to 1535 * encapsulating outbound packets. 1536 * 1537 * The function is mostly used to find a routing entry for the gateway, 1538 * which in some protocol families could also point to the link-level 1539 * address for the gateway itself (the side effect of revalidating the 1540 * route to the destination is rather pointless at this stage, we did it 1541 * already a moment before in the pr_output() routine to locate the ifp 1542 * and gateway to use). 1543 * 1544 * When we remove the layer-3 to layer-2 mapping tables from the 1545 * routing table, this function can be removed. 1546 * 1547 * === On input === 1548 * *dst is the address of the NEXT HOP (which coincides with the 1549 * final destination if directly reachable); 1550 * *lrt0 points to the cached route to the final destination; 1551 * *lrt is not meaningful; 1552 * (*lrt0 has no ref held on it by us so REMREF is not needed. 1553 * Refs only account for major structural references and not usages, 1554 * which is actually a bit of a problem.) 1555 * 1556 * === Operation === 1557 * If the route is marked down try to find a new route. If the route 1558 * to the gateway is gone, try to setup a new route. Otherwise, 1559 * if the route is marked for packets to be rejected, enforce that. 1560 * Note that rtalloc returns an rtentry with an extra REF that we may 1561 * need to lose. 1562 * 1563 * === On return === 1564 * *dst is unchanged; 1565 * *lrt0 points to the (possibly new) route to the final destination 1566 * *lrt points to the route to the next hop [LOCKED] 1567 * 1568 * Their values are meaningful ONLY if no error is returned. 1569 * 1570 * To follow this you have to remember that: 1571 * RT_REMREF reduces the reference count by 1 but doesn't check it for 0 (!) 1572 * RTFREE_LOCKED includes an RT_REMREF (or an rtfree if refs == 1) 1573 * and an RT_UNLOCK 1574 * RTFREE does an RT_LOCK and an RTFREE_LOCKED 1575 * The gwroute pointer counts as a reference on the rtentry to which it points. 1576 * so when we add it we use the ref that rtalloc gives us and when we lose it 1577 * we need to remove the reference. 1578 * RT_TEMP_UNLOCK does an RT_ADDREF before freeing the lock, and 1579 * RT_RELOCK locks it (it can't have gone away due to the ref) and 1580 * drops the ref, possibly freeing it and zeroing the pointer if 1581 * the ref goes to 0 (unlocking in the process). 1582 */ 1583 int 1584 rt_check(struct rtentry **lrt, struct rtentry **lrt0, struct sockaddr *dst) 1585 { 1586 struct rtentry *rt; 1587 struct rtentry *rt0; 1588 u_int fibnum; 1589 1590 KASSERT(*lrt0 != NULL, ("rt_check")); 1591 rt0 = *lrt0; 1592 rt = NULL; 1593 fibnum = rt0->rt_fibnum; 1594 1595 /* NB: the locking here is tortuous... */ 1596 RT_LOCK(rt0); 1597 retry: 1598 if (rt0 && (rt0->rt_flags & RTF_UP) == 0) { 1599 /* Current rt0 is useless, try get a replacement. */ 1600 RT_UNLOCK(rt0); 1601 rt0 = NULL; 1602 } 1603 if (rt0 == NULL) { 1604 rt0 = rtalloc1_fib(dst, 1, 0UL, fibnum); 1605 if (rt0 == NULL) { 1606 return (EHOSTUNREACH); 1607 } 1608 RT_REMREF(rt0); /* don't need the reference. */ 1609 } 1610 1611 if (rt0->rt_flags & RTF_GATEWAY) { 1612 if ((rt = rt0->rt_gwroute) != NULL) { 1613 RT_LOCK(rt); /* NB: gwroute */ 1614 if ((rt->rt_flags & RTF_UP) == 0) { 1615 /* gw route is dud. ignore/lose it */ 1616 RTFREE_LOCKED(rt); /* unref (&unlock) gwroute */ 1617 rt = rt0->rt_gwroute = NULL; 1618 } 1619 } 1620 1621 if (rt == NULL) { /* NOT AN ELSE CLAUSE */ 1622 RT_TEMP_UNLOCK(rt0); /* MUST return to undo this */ 1623 rt = rtalloc1_fib(rt0->rt_gateway, 1, 0UL, fibnum); 1624 if ((rt == rt0) || (rt == NULL)) { 1625 /* the best we can do is not good enough */ 1626 if (rt) { 1627 RT_REMREF(rt); /* assumes ref > 0 */ 1628 RT_UNLOCK(rt); 1629 } 1630 RTFREE(rt0); /* lock, unref, (unlock) */ 1631 return (ENETUNREACH); 1632 } 1633 /* 1634 * Relock it and lose the added reference. 1635 * All sorts of things could have happenned while we 1636 * had no lock on it, so check for them. 1637 */ 1638 RT_RELOCK(rt0); 1639 if (rt0 == NULL || ((rt0->rt_flags & RTF_UP) == 0)) 1640 /* Ru-roh.. what we had is no longer any good */ 1641 goto retry; 1642 /* 1643 * While we were away, someone replaced the gateway. 1644 * Since a reference count is involved we can't just 1645 * overwrite it. 1646 */ 1647 if (rt0->rt_gwroute) { 1648 if (rt0->rt_gwroute != rt) { 1649 RTFREE_LOCKED(rt); 1650 goto retry; 1651 } 1652 } else { 1653 rt0->rt_gwroute = rt; 1654 } 1655 } 1656 RT_LOCK_ASSERT(rt); 1657 RT_UNLOCK(rt0); 1658 } else { 1659 /* think of rt as having the lock from now on.. */ 1660 rt = rt0; 1661 } 1662 /* XXX why are we inspecting rmx_expire? */ 1663 if ((rt->rt_flags & RTF_REJECT) && 1664 (rt->rt_rmx.rmx_expire == 0 || 1665 time_uptime < rt->rt_rmx.rmx_expire)) { 1666 RT_UNLOCK(rt); 1667 return (rt == rt0 ? EHOSTDOWN : EHOSTUNREACH); 1668 } 1669 1670 *lrt = rt; 1671 *lrt0 = rt0; 1672 return (0); 1673 } 1674 1675 /* This must be before ip6_init2(), which is now SI_ORDER_MIDDLE */ 1676 SYSINIT(route, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, route_init, 0);
Cache object: 020a7d44d260608c18c5219fe8475fc3
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