1 /* 2 * Linux INET6 implementation 3 * FIB front-end. 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * $Id: route.c,v 1.56 2001/10/31 21:55:55 davem Exp $ 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 /* Changes: 17 * 18 * YOSHIFUJI Hideaki @USAGI 19 * reworked default router selection. 20 * - respect outgoing interface 21 * - select from (probably) reachable routers (i.e. 22 * routers in REACHABLE, STALE, DELAY or PROBE states). 23 * - always select the same router if it is (probably) 24 * reachable. otherwise, round-robin the list. 25 * Ville Nuorvala 26 * Fixed routing subtrees. 27 */ 28 29 #include <linux/capability.h> 30 #include <linux/errno.h> 31 #include <linux/types.h> 32 #include <linux/times.h> 33 #include <linux/socket.h> 34 #include <linux/sockios.h> 35 #include <linux/net.h> 36 #include <linux/route.h> 37 #include <linux/netdevice.h> 38 #include <linux/in6.h> 39 #include <linux/init.h> 40 #include <linux/if_arp.h> 41 42 #ifdef CONFIG_PROC_FS 43 #include <linux/proc_fs.h> 44 #include <linux/seq_file.h> 45 #endif 46 47 #include <net/snmp.h> 48 #include <net/ipv6.h> 49 #include <net/ip6_fib.h> 50 #include <net/ip6_route.h> 51 #include <net/ndisc.h> 52 #include <net/addrconf.h> 53 #include <net/tcp.h> 54 #include <linux/rtnetlink.h> 55 #include <net/dst.h> 56 #include <net/xfrm.h> 57 #include <net/netevent.h> 58 #include <net/netlink.h> 59 60 #include <asm/uaccess.h> 61 62 #ifdef CONFIG_SYSCTL 63 #include <linux/sysctl.h> 64 #endif 65 66 /* Set to 3 to get tracing. */ 67 #define RT6_DEBUG 2 68 69 #if RT6_DEBUG >= 3 70 #define RDBG(x) printk x 71 #define RT6_TRACE(x...) printk(KERN_DEBUG x) 72 #else 73 #define RDBG(x) 74 #define RT6_TRACE(x...) do { ; } while (0) 75 #endif 76 77 #define CLONE_OFFLINK_ROUTE 0 78 79 static int ip6_rt_max_size = 4096; 80 static int ip6_rt_gc_min_interval = HZ / 2; 81 static int ip6_rt_gc_timeout = 60*HZ; 82 int ip6_rt_gc_interval = 30*HZ; 83 static int ip6_rt_gc_elasticity = 9; 84 static int ip6_rt_mtu_expires = 10*60*HZ; 85 static int ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; 86 87 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort); 88 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); 89 static struct dst_entry *ip6_negative_advice(struct dst_entry *); 90 static void ip6_dst_destroy(struct dst_entry *); 91 static void ip6_dst_ifdown(struct dst_entry *, 92 struct net_device *dev, int how); 93 static int ip6_dst_gc(void); 94 95 static int ip6_pkt_discard(struct sk_buff *skb); 96 static int ip6_pkt_discard_out(struct sk_buff *skb); 97 static void ip6_link_failure(struct sk_buff *skb); 98 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu); 99 100 #ifdef CONFIG_IPV6_ROUTE_INFO 101 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen, 102 struct in6_addr *gwaddr, int ifindex, 103 unsigned pref); 104 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen, 105 struct in6_addr *gwaddr, int ifindex); 106 #endif 107 108 static struct dst_ops ip6_dst_ops = { 109 .family = AF_INET6, 110 .protocol = __constant_htons(ETH_P_IPV6), 111 .gc = ip6_dst_gc, 112 .gc_thresh = 1024, 113 .check = ip6_dst_check, 114 .destroy = ip6_dst_destroy, 115 .ifdown = ip6_dst_ifdown, 116 .negative_advice = ip6_negative_advice, 117 .link_failure = ip6_link_failure, 118 .update_pmtu = ip6_rt_update_pmtu, 119 .entry_size = sizeof(struct rt6_info), 120 }; 121 122 struct rt6_info ip6_null_entry = { 123 .u = { 124 .dst = { 125 .__refcnt = ATOMIC_INIT(1), 126 .__use = 1, 127 .dev = &loopback_dev, 128 .obsolete = -1, 129 .error = -ENETUNREACH, 130 .metrics = { [RTAX_HOPLIMIT - 1] = 255, }, 131 .input = ip6_pkt_discard, 132 .output = ip6_pkt_discard_out, 133 .ops = &ip6_dst_ops, 134 .path = (struct dst_entry*)&ip6_null_entry, 135 } 136 }, 137 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 138 .rt6i_metric = ~(u32) 0, 139 .rt6i_ref = ATOMIC_INIT(1), 140 }; 141 142 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 143 144 static int ip6_pkt_prohibit(struct sk_buff *skb); 145 static int ip6_pkt_prohibit_out(struct sk_buff *skb); 146 static int ip6_pkt_blk_hole(struct sk_buff *skb); 147 148 struct rt6_info ip6_prohibit_entry = { 149 .u = { 150 .dst = { 151 .__refcnt = ATOMIC_INIT(1), 152 .__use = 1, 153 .dev = &loopback_dev, 154 .obsolete = -1, 155 .error = -EACCES, 156 .metrics = { [RTAX_HOPLIMIT - 1] = 255, }, 157 .input = ip6_pkt_prohibit, 158 .output = ip6_pkt_prohibit_out, 159 .ops = &ip6_dst_ops, 160 .path = (struct dst_entry*)&ip6_prohibit_entry, 161 } 162 }, 163 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 164 .rt6i_metric = ~(u32) 0, 165 .rt6i_ref = ATOMIC_INIT(1), 166 }; 167 168 struct rt6_info ip6_blk_hole_entry = { 169 .u = { 170 .dst = { 171 .__refcnt = ATOMIC_INIT(1), 172 .__use = 1, 173 .dev = &loopback_dev, 174 .obsolete = -1, 175 .error = -EINVAL, 176 .metrics = { [RTAX_HOPLIMIT - 1] = 255, }, 177 .input = ip6_pkt_blk_hole, 178 .output = ip6_pkt_blk_hole, 179 .ops = &ip6_dst_ops, 180 .path = (struct dst_entry*)&ip6_blk_hole_entry, 181 } 182 }, 183 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 184 .rt6i_metric = ~(u32) 0, 185 .rt6i_ref = ATOMIC_INIT(1), 186 }; 187 188 #endif 189 190 /* allocate dst with ip6_dst_ops */ 191 static __inline__ struct rt6_info *ip6_dst_alloc(void) 192 { 193 return (struct rt6_info *)dst_alloc(&ip6_dst_ops); 194 } 195 196 static void ip6_dst_destroy(struct dst_entry *dst) 197 { 198 struct rt6_info *rt = (struct rt6_info *)dst; 199 struct inet6_dev *idev = rt->rt6i_idev; 200 201 if (idev != NULL) { 202 rt->rt6i_idev = NULL; 203 in6_dev_put(idev); 204 } 205 } 206 207 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 208 int how) 209 { 210 struct rt6_info *rt = (struct rt6_info *)dst; 211 struct inet6_dev *idev = rt->rt6i_idev; 212 213 if (dev != &loopback_dev && idev != NULL && idev->dev == dev) { 214 struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev); 215 if (loopback_idev != NULL) { 216 rt->rt6i_idev = loopback_idev; 217 in6_dev_put(idev); 218 } 219 } 220 } 221 222 static __inline__ int rt6_check_expired(const struct rt6_info *rt) 223 { 224 return (rt->rt6i_flags & RTF_EXPIRES && 225 time_after(jiffies, rt->rt6i_expires)); 226 } 227 228 static inline int rt6_need_strict(struct in6_addr *daddr) 229 { 230 return (ipv6_addr_type(daddr) & 231 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); 232 } 233 234 /* 235 * Route lookup. Any table->tb6_lock is implied. 236 */ 237 238 static __inline__ struct rt6_info *rt6_device_match(struct rt6_info *rt, 239 int oif, 240 int strict) 241 { 242 struct rt6_info *local = NULL; 243 struct rt6_info *sprt; 244 245 if (oif) { 246 for (sprt = rt; sprt; sprt = sprt->u.dst.rt6_next) { 247 struct net_device *dev = sprt->rt6i_dev; 248 if (dev->ifindex == oif) 249 return sprt; 250 if (dev->flags & IFF_LOOPBACK) { 251 if (sprt->rt6i_idev == NULL || 252 sprt->rt6i_idev->dev->ifindex != oif) { 253 if (strict && oif) 254 continue; 255 if (local && (!oif || 256 local->rt6i_idev->dev->ifindex == oif)) 257 continue; 258 } 259 local = sprt; 260 } 261 } 262 263 if (local) 264 return local; 265 266 if (strict) 267 return &ip6_null_entry; 268 } 269 return rt; 270 } 271 272 #ifdef CONFIG_IPV6_ROUTER_PREF 273 static void rt6_probe(struct rt6_info *rt) 274 { 275 struct neighbour *neigh = rt ? rt->rt6i_nexthop : NULL; 276 /* 277 * Okay, this does not seem to be appropriate 278 * for now, however, we need to check if it 279 * is really so; aka Router Reachability Probing. 280 * 281 * Router Reachability Probe MUST be rate-limited 282 * to no more than one per minute. 283 */ 284 if (!neigh || (neigh->nud_state & NUD_VALID)) 285 return; 286 read_lock_bh(&neigh->lock); 287 if (!(neigh->nud_state & NUD_VALID) && 288 time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) { 289 struct in6_addr mcaddr; 290 struct in6_addr *target; 291 292 neigh->updated = jiffies; 293 read_unlock_bh(&neigh->lock); 294 295 target = (struct in6_addr *)&neigh->primary_key; 296 addrconf_addr_solict_mult(target, &mcaddr); 297 ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL); 298 } else 299 read_unlock_bh(&neigh->lock); 300 } 301 #else 302 static inline void rt6_probe(struct rt6_info *rt) 303 { 304 return; 305 } 306 #endif 307 308 /* 309 * Default Router Selection (RFC 2461 6.3.6) 310 */ 311 static inline int rt6_check_dev(struct rt6_info *rt, int oif) 312 { 313 struct net_device *dev = rt->rt6i_dev; 314 if (!oif || dev->ifindex == oif) 315 return 2; 316 if ((dev->flags & IFF_LOOPBACK) && 317 rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif) 318 return 1; 319 return 0; 320 } 321 322 static inline int rt6_check_neigh(struct rt6_info *rt) 323 { 324 struct neighbour *neigh = rt->rt6i_nexthop; 325 int m = 0; 326 if (rt->rt6i_flags & RTF_NONEXTHOP || 327 !(rt->rt6i_flags & RTF_GATEWAY)) 328 m = 1; 329 else if (neigh) { 330 read_lock_bh(&neigh->lock); 331 if (neigh->nud_state & NUD_VALID) 332 m = 2; 333 else if (!(neigh->nud_state & NUD_FAILED)) 334 m = 1; 335 read_unlock_bh(&neigh->lock); 336 } 337 return m; 338 } 339 340 static int rt6_score_route(struct rt6_info *rt, int oif, 341 int strict) 342 { 343 int m, n; 344 345 m = rt6_check_dev(rt, oif); 346 if (!m && (strict & RT6_LOOKUP_F_IFACE)) 347 return -1; 348 #ifdef CONFIG_IPV6_ROUTER_PREF 349 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2; 350 #endif 351 n = rt6_check_neigh(rt); 352 if (!n && (strict & RT6_LOOKUP_F_REACHABLE)) 353 return -1; 354 return m; 355 } 356 357 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict, 358 int *mpri, struct rt6_info *match) 359 { 360 int m; 361 362 if (rt6_check_expired(rt)) 363 goto out; 364 365 m = rt6_score_route(rt, oif, strict); 366 if (m < 0) 367 goto out; 368 369 if (m > *mpri) { 370 if (strict & RT6_LOOKUP_F_REACHABLE) 371 rt6_probe(match); 372 *mpri = m; 373 match = rt; 374 } else if (strict & RT6_LOOKUP_F_REACHABLE) { 375 rt6_probe(rt); 376 } 377 378 out: 379 return match; 380 } 381 382 static struct rt6_info *find_rr_leaf(struct fib6_node *fn, 383 struct rt6_info *rr_head, 384 u32 metric, int oif, int strict) 385 { 386 struct rt6_info *rt, *match; 387 int mpri = -1; 388 389 match = NULL; 390 for (rt = rr_head; rt && rt->rt6i_metric == metric; 391 rt = rt->u.dst.rt6_next) 392 match = find_match(rt, oif, strict, &mpri, match); 393 for (rt = fn->leaf; rt && rt != rr_head && rt->rt6i_metric == metric; 394 rt = rt->u.dst.rt6_next) 395 match = find_match(rt, oif, strict, &mpri, match); 396 397 return match; 398 } 399 400 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict) 401 { 402 struct rt6_info *match, *rt0; 403 404 RT6_TRACE("%s(fn->leaf=%p, oif=%d)\n", 405 __FUNCTION__, fn->leaf, oif); 406 407 rt0 = fn->rr_ptr; 408 if (!rt0) 409 fn->rr_ptr = rt0 = fn->leaf; 410 411 match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict); 412 413 if (!match && 414 (strict & RT6_LOOKUP_F_REACHABLE)) { 415 struct rt6_info *next = rt0->u.dst.rt6_next; 416 417 /* no entries matched; do round-robin */ 418 if (!next || next->rt6i_metric != rt0->rt6i_metric) 419 next = fn->leaf; 420 421 if (next != rt0) 422 fn->rr_ptr = next; 423 } 424 425 RT6_TRACE("%s() => %p\n", 426 __FUNCTION__, match); 427 428 return (match ? match : &ip6_null_entry); 429 } 430 431 #ifdef CONFIG_IPV6_ROUTE_INFO 432 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 433 struct in6_addr *gwaddr) 434 { 435 struct route_info *rinfo = (struct route_info *) opt; 436 struct in6_addr prefix_buf, *prefix; 437 unsigned int pref; 438 u32 lifetime; 439 struct rt6_info *rt; 440 441 if (len < sizeof(struct route_info)) { 442 return -EINVAL; 443 } 444 445 /* Sanity check for prefix_len and length */ 446 if (rinfo->length > 3) { 447 return -EINVAL; 448 } else if (rinfo->prefix_len > 128) { 449 return -EINVAL; 450 } else if (rinfo->prefix_len > 64) { 451 if (rinfo->length < 2) { 452 return -EINVAL; 453 } 454 } else if (rinfo->prefix_len > 0) { 455 if (rinfo->length < 1) { 456 return -EINVAL; 457 } 458 } 459 460 pref = rinfo->route_pref; 461 if (pref == ICMPV6_ROUTER_PREF_INVALID) 462 pref = ICMPV6_ROUTER_PREF_MEDIUM; 463 464 lifetime = ntohl(rinfo->lifetime); 465 if (lifetime == 0xffffffff) { 466 /* infinity */ 467 } else if (lifetime > 0x7fffffff/HZ) { 468 /* Avoid arithmetic overflow */ 469 lifetime = 0x7fffffff/HZ - 1; 470 } 471 472 if (rinfo->length == 3) 473 prefix = (struct in6_addr *)rinfo->prefix; 474 else { 475 /* this function is safe */ 476 ipv6_addr_prefix(&prefix_buf, 477 (struct in6_addr *)rinfo->prefix, 478 rinfo->prefix_len); 479 prefix = &prefix_buf; 480 } 481 482 rt = rt6_get_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex); 483 484 if (rt && !lifetime) { 485 ip6_del_rt(rt); 486 rt = NULL; 487 } 488 489 if (!rt && lifetime) 490 rt = rt6_add_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex, 491 pref); 492 else if (rt) 493 rt->rt6i_flags = RTF_ROUTEINFO | 494 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 495 496 if (rt) { 497 if (lifetime == 0xffffffff) { 498 rt->rt6i_flags &= ~RTF_EXPIRES; 499 } else { 500 rt->rt6i_expires = jiffies + HZ * lifetime; 501 rt->rt6i_flags |= RTF_EXPIRES; 502 } 503 dst_release(&rt->u.dst); 504 } 505 return 0; 506 } 507 #endif 508 509 #define BACKTRACK(saddr) \ 510 do { \ 511 if (rt == &ip6_null_entry) { \ 512 struct fib6_node *pn; \ 513 while (1) { \ 514 if (fn->fn_flags & RTN_TL_ROOT) \ 515 goto out; \ 516 pn = fn->parent; \ 517 if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) \ 518 fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); \ 519 else \ 520 fn = pn; \ 521 if (fn->fn_flags & RTN_RTINFO) \ 522 goto restart; \ 523 } \ 524 } \ 525 } while(0) 526 527 static struct rt6_info *ip6_pol_route_lookup(struct fib6_table *table, 528 struct flowi *fl, int flags) 529 { 530 struct fib6_node *fn; 531 struct rt6_info *rt; 532 533 read_lock_bh(&table->tb6_lock); 534 fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src); 535 restart: 536 rt = fn->leaf; 537 rt = rt6_device_match(rt, fl->oif, flags); 538 BACKTRACK(&fl->fl6_src); 539 out: 540 dst_hold(&rt->u.dst); 541 read_unlock_bh(&table->tb6_lock); 542 543 rt->u.dst.lastuse = jiffies; 544 rt->u.dst.__use++; 545 546 return rt; 547 548 } 549 550 struct rt6_info *rt6_lookup(struct in6_addr *daddr, struct in6_addr *saddr, 551 int oif, int strict) 552 { 553 struct flowi fl = { 554 .oif = oif, 555 .nl_u = { 556 .ip6_u = { 557 .daddr = *daddr, 558 }, 559 }, 560 }; 561 struct dst_entry *dst; 562 int flags = strict ? RT6_LOOKUP_F_IFACE : 0; 563 564 if (saddr) { 565 memcpy(&fl.fl6_src, saddr, sizeof(*saddr)); 566 flags |= RT6_LOOKUP_F_HAS_SADDR; 567 } 568 569 dst = fib6_rule_lookup(&fl, flags, ip6_pol_route_lookup); 570 if (dst->error == 0) 571 return (struct rt6_info *) dst; 572 573 dst_release(dst); 574 575 return NULL; 576 } 577 578 EXPORT_SYMBOL(rt6_lookup); 579 580 /* ip6_ins_rt is called with FREE table->tb6_lock. 581 It takes new route entry, the addition fails by any reason the 582 route is freed. In any case, if caller does not hold it, it may 583 be destroyed. 584 */ 585 586 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info) 587 { 588 int err; 589 struct fib6_table *table; 590 591 table = rt->rt6i_table; 592 write_lock_bh(&table->tb6_lock); 593 err = fib6_add(&table->tb6_root, rt, info); 594 write_unlock_bh(&table->tb6_lock); 595 596 return err; 597 } 598 599 int ip6_ins_rt(struct rt6_info *rt) 600 { 601 return __ip6_ins_rt(rt, NULL); 602 } 603 604 static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, struct in6_addr *daddr, 605 struct in6_addr *saddr) 606 { 607 struct rt6_info *rt; 608 609 /* 610 * Clone the route. 611 */ 612 613 rt = ip6_rt_copy(ort); 614 615 if (rt) { 616 if (!(rt->rt6i_flags&RTF_GATEWAY)) { 617 if (rt->rt6i_dst.plen != 128 && 618 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr)) 619 rt->rt6i_flags |= RTF_ANYCAST; 620 ipv6_addr_copy(&rt->rt6i_gateway, daddr); 621 } 622 623 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr); 624 rt->rt6i_dst.plen = 128; 625 rt->rt6i_flags |= RTF_CACHE; 626 rt->u.dst.flags |= DST_HOST; 627 628 #ifdef CONFIG_IPV6_SUBTREES 629 if (rt->rt6i_src.plen && saddr) { 630 ipv6_addr_copy(&rt->rt6i_src.addr, saddr); 631 rt->rt6i_src.plen = 128; 632 } 633 #endif 634 635 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway); 636 637 } 638 639 return rt; 640 } 641 642 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, struct in6_addr *daddr) 643 { 644 struct rt6_info *rt = ip6_rt_copy(ort); 645 if (rt) { 646 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr); 647 rt->rt6i_dst.plen = 128; 648 rt->rt6i_flags |= RTF_CACHE; 649 rt->u.dst.flags |= DST_HOST; 650 rt->rt6i_nexthop = neigh_clone(ort->rt6i_nexthop); 651 } 652 return rt; 653 } 654 655 static struct rt6_info *ip6_pol_route_input(struct fib6_table *table, 656 struct flowi *fl, int flags) 657 { 658 struct fib6_node *fn; 659 struct rt6_info *rt, *nrt; 660 int strict = 0; 661 int attempts = 3; 662 int err; 663 int reachable = ipv6_devconf.forwarding ? 0 : RT6_LOOKUP_F_REACHABLE; 664 665 strict |= flags & RT6_LOOKUP_F_IFACE; 666 667 relookup: 668 read_lock_bh(&table->tb6_lock); 669 670 restart_2: 671 fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src); 672 673 restart: 674 rt = rt6_select(fn, fl->iif, strict | reachable); 675 BACKTRACK(&fl->fl6_src); 676 if (rt == &ip6_null_entry || 677 rt->rt6i_flags & RTF_CACHE) 678 goto out; 679 680 dst_hold(&rt->u.dst); 681 read_unlock_bh(&table->tb6_lock); 682 683 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) 684 nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src); 685 else { 686 #if CLONE_OFFLINK_ROUTE 687 nrt = rt6_alloc_clone(rt, &fl->fl6_dst); 688 #else 689 goto out2; 690 #endif 691 } 692 693 dst_release(&rt->u.dst); 694 rt = nrt ? : &ip6_null_entry; 695 696 dst_hold(&rt->u.dst); 697 if (nrt) { 698 err = ip6_ins_rt(nrt); 699 if (!err) 700 goto out2; 701 } 702 703 if (--attempts <= 0) 704 goto out2; 705 706 /* 707 * Race condition! In the gap, when table->tb6_lock was 708 * released someone could insert this route. Relookup. 709 */ 710 dst_release(&rt->u.dst); 711 goto relookup; 712 713 out: 714 if (reachable) { 715 reachable = 0; 716 goto restart_2; 717 } 718 dst_hold(&rt->u.dst); 719 read_unlock_bh(&table->tb6_lock); 720 out2: 721 rt->u.dst.lastuse = jiffies; 722 rt->u.dst.__use++; 723 724 return rt; 725 } 726 727 void ip6_route_input(struct sk_buff *skb) 728 { 729 struct ipv6hdr *iph = ipv6_hdr(skb); 730 int flags = RT6_LOOKUP_F_HAS_SADDR; 731 struct flowi fl = { 732 .iif = skb->dev->ifindex, 733 .nl_u = { 734 .ip6_u = { 735 .daddr = iph->daddr, 736 .saddr = iph->saddr, 737 .flowlabel = (* (__be32 *) iph)&IPV6_FLOWINFO_MASK, 738 }, 739 }, 740 .mark = skb->mark, 741 .proto = iph->nexthdr, 742 }; 743 744 if (rt6_need_strict(&iph->daddr)) 745 flags |= RT6_LOOKUP_F_IFACE; 746 747 skb->dst = fib6_rule_lookup(&fl, flags, ip6_pol_route_input); 748 } 749 750 static struct rt6_info *ip6_pol_route_output(struct fib6_table *table, 751 struct flowi *fl, int flags) 752 { 753 struct fib6_node *fn; 754 struct rt6_info *rt, *nrt; 755 int strict = 0; 756 int attempts = 3; 757 int err; 758 int reachable = ipv6_devconf.forwarding ? 0 : RT6_LOOKUP_F_REACHABLE; 759 760 strict |= flags & RT6_LOOKUP_F_IFACE; 761 762 relookup: 763 read_lock_bh(&table->tb6_lock); 764 765 restart_2: 766 fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src); 767 768 restart: 769 rt = rt6_select(fn, fl->oif, strict | reachable); 770 BACKTRACK(&fl->fl6_src); 771 if (rt == &ip6_null_entry || 772 rt->rt6i_flags & RTF_CACHE) 773 goto out; 774 775 dst_hold(&rt->u.dst); 776 read_unlock_bh(&table->tb6_lock); 777 778 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) 779 nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src); 780 else { 781 #if CLONE_OFFLINK_ROUTE 782 nrt = rt6_alloc_clone(rt, &fl->fl6_dst); 783 #else 784 goto out2; 785 #endif 786 } 787 788 dst_release(&rt->u.dst); 789 rt = nrt ? : &ip6_null_entry; 790 791 dst_hold(&rt->u.dst); 792 if (nrt) { 793 err = ip6_ins_rt(nrt); 794 if (!err) 795 goto out2; 796 } 797 798 if (--attempts <= 0) 799 goto out2; 800 801 /* 802 * Race condition! In the gap, when table->tb6_lock was 803 * released someone could insert this route. Relookup. 804 */ 805 dst_release(&rt->u.dst); 806 goto relookup; 807 808 out: 809 if (reachable) { 810 reachable = 0; 811 goto restart_2; 812 } 813 dst_hold(&rt->u.dst); 814 read_unlock_bh(&table->tb6_lock); 815 out2: 816 rt->u.dst.lastuse = jiffies; 817 rt->u.dst.__use++; 818 return rt; 819 } 820 821 struct dst_entry * ip6_route_output(struct sock *sk, struct flowi *fl) 822 { 823 int flags = 0; 824 825 if (rt6_need_strict(&fl->fl6_dst)) 826 flags |= RT6_LOOKUP_F_IFACE; 827 828 if (!ipv6_addr_any(&fl->fl6_src)) 829 flags |= RT6_LOOKUP_F_HAS_SADDR; 830 831 return fib6_rule_lookup(fl, flags, ip6_pol_route_output); 832 } 833 834 EXPORT_SYMBOL(ip6_route_output); 835 836 /* 837 * Destination cache support functions 838 */ 839 840 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) 841 { 842 struct rt6_info *rt; 843 844 rt = (struct rt6_info *) dst; 845 846 if (rt && rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie)) 847 return dst; 848 849 return NULL; 850 } 851 852 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) 853 { 854 struct rt6_info *rt = (struct rt6_info *) dst; 855 856 if (rt) { 857 if (rt->rt6i_flags & RTF_CACHE) 858 ip6_del_rt(rt); 859 else 860 dst_release(dst); 861 } 862 return NULL; 863 } 864 865 static void ip6_link_failure(struct sk_buff *skb) 866 { 867 struct rt6_info *rt; 868 869 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev); 870 871 rt = (struct rt6_info *) skb->dst; 872 if (rt) { 873 if (rt->rt6i_flags&RTF_CACHE) { 874 dst_set_expires(&rt->u.dst, 0); 875 rt->rt6i_flags |= RTF_EXPIRES; 876 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) 877 rt->rt6i_node->fn_sernum = -1; 878 } 879 } 880 881 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 882 { 883 struct rt6_info *rt6 = (struct rt6_info*)dst; 884 885 if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) { 886 rt6->rt6i_flags |= RTF_MODIFIED; 887 if (mtu < IPV6_MIN_MTU) { 888 mtu = IPV6_MIN_MTU; 889 dst->metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 890 } 891 dst->metrics[RTAX_MTU-1] = mtu; 892 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst); 893 } 894 } 895 896 static int ipv6_get_mtu(struct net_device *dev); 897 898 static inline unsigned int ipv6_advmss(unsigned int mtu) 899 { 900 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); 901 902 if (mtu < ip6_rt_min_advmss) 903 mtu = ip6_rt_min_advmss; 904 905 /* 906 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and 907 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. 908 * IPV6_MAXPLEN is also valid and means: "any MSS, 909 * rely only on pmtu discovery" 910 */ 911 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) 912 mtu = IPV6_MAXPLEN; 913 return mtu; 914 } 915 916 static struct dst_entry *ndisc_dst_gc_list; 917 static DEFINE_SPINLOCK(ndisc_lock); 918 919 struct dst_entry *ndisc_dst_alloc(struct net_device *dev, 920 struct neighbour *neigh, 921 struct in6_addr *addr, 922 int (*output)(struct sk_buff *)) 923 { 924 struct rt6_info *rt; 925 struct inet6_dev *idev = in6_dev_get(dev); 926 927 if (unlikely(idev == NULL)) 928 return NULL; 929 930 rt = ip6_dst_alloc(); 931 if (unlikely(rt == NULL)) { 932 in6_dev_put(idev); 933 goto out; 934 } 935 936 dev_hold(dev); 937 if (neigh) 938 neigh_hold(neigh); 939 else 940 neigh = ndisc_get_neigh(dev, addr); 941 942 rt->rt6i_dev = dev; 943 rt->rt6i_idev = idev; 944 rt->rt6i_nexthop = neigh; 945 atomic_set(&rt->u.dst.__refcnt, 1); 946 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = 255; 947 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev); 948 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 949 rt->u.dst.output = output; 950 951 #if 0 /* there's no chance to use these for ndisc */ 952 rt->u.dst.flags = ipv6_addr_type(addr) & IPV6_ADDR_UNICAST 953 ? DST_HOST 954 : 0; 955 ipv6_addr_copy(&rt->rt6i_dst.addr, addr); 956 rt->rt6i_dst.plen = 128; 957 #endif 958 959 spin_lock_bh(&ndisc_lock); 960 rt->u.dst.next = ndisc_dst_gc_list; 961 ndisc_dst_gc_list = &rt->u.dst; 962 spin_unlock_bh(&ndisc_lock); 963 964 fib6_force_start_gc(); 965 966 out: 967 return &rt->u.dst; 968 } 969 970 int ndisc_dst_gc(int *more) 971 { 972 struct dst_entry *dst, *next, **pprev; 973 int freed; 974 975 next = NULL; 976 freed = 0; 977 978 spin_lock_bh(&ndisc_lock); 979 pprev = &ndisc_dst_gc_list; 980 981 while ((dst = *pprev) != NULL) { 982 if (!atomic_read(&dst->__refcnt)) { 983 *pprev = dst->next; 984 dst_free(dst); 985 freed++; 986 } else { 987 pprev = &dst->next; 988 (*more)++; 989 } 990 } 991 992 spin_unlock_bh(&ndisc_lock); 993 994 return freed; 995 } 996 997 static int ip6_dst_gc(void) 998 { 999 static unsigned expire = 30*HZ; 1000 static unsigned long last_gc; 1001 unsigned long now = jiffies; 1002 1003 if (time_after(last_gc + ip6_rt_gc_min_interval, now) && 1004 atomic_read(&ip6_dst_ops.entries) <= ip6_rt_max_size) 1005 goto out; 1006 1007 expire++; 1008 fib6_run_gc(expire); 1009 last_gc = now; 1010 if (atomic_read(&ip6_dst_ops.entries) < ip6_dst_ops.gc_thresh) 1011 expire = ip6_rt_gc_timeout>>1; 1012 1013 out: 1014 expire -= expire>>ip6_rt_gc_elasticity; 1015 return (atomic_read(&ip6_dst_ops.entries) > ip6_rt_max_size); 1016 } 1017 1018 /* Clean host part of a prefix. Not necessary in radix tree, 1019 but results in cleaner routing tables. 1020 1021 Remove it only when all the things will work! 1022 */ 1023 1024 static int ipv6_get_mtu(struct net_device *dev) 1025 { 1026 int mtu = IPV6_MIN_MTU; 1027 struct inet6_dev *idev; 1028 1029 idev = in6_dev_get(dev); 1030 if (idev) { 1031 mtu = idev->cnf.mtu6; 1032 in6_dev_put(idev); 1033 } 1034 return mtu; 1035 } 1036 1037 int ipv6_get_hoplimit(struct net_device *dev) 1038 { 1039 int hoplimit = ipv6_devconf.hop_limit; 1040 struct inet6_dev *idev; 1041 1042 idev = in6_dev_get(dev); 1043 if (idev) { 1044 hoplimit = idev->cnf.hop_limit; 1045 in6_dev_put(idev); 1046 } 1047 return hoplimit; 1048 } 1049 1050 /* 1051 * 1052 */ 1053 1054 int ip6_route_add(struct fib6_config *cfg) 1055 { 1056 int err; 1057 struct rt6_info *rt = NULL; 1058 struct net_device *dev = NULL; 1059 struct inet6_dev *idev = NULL; 1060 struct fib6_table *table; 1061 int addr_type; 1062 1063 if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128) 1064 return -EINVAL; 1065 #ifndef CONFIG_IPV6_SUBTREES 1066 if (cfg->fc_src_len) 1067 return -EINVAL; 1068 #endif 1069 if (cfg->fc_ifindex) { 1070 err = -ENODEV; 1071 dev = dev_get_by_index(cfg->fc_ifindex); 1072 if (!dev) 1073 goto out; 1074 idev = in6_dev_get(dev); 1075 if (!idev) 1076 goto out; 1077 } 1078 1079 if (cfg->fc_metric == 0) 1080 cfg->fc_metric = IP6_RT_PRIO_USER; 1081 1082 table = fib6_new_table(cfg->fc_table); 1083 if (table == NULL) { 1084 err = -ENOBUFS; 1085 goto out; 1086 } 1087 1088 rt = ip6_dst_alloc(); 1089 1090 if (rt == NULL) { 1091 err = -ENOMEM; 1092 goto out; 1093 } 1094 1095 rt->u.dst.obsolete = -1; 1096 rt->rt6i_expires = jiffies + clock_t_to_jiffies(cfg->fc_expires); 1097 1098 if (cfg->fc_protocol == RTPROT_UNSPEC) 1099 cfg->fc_protocol = RTPROT_BOOT; 1100 rt->rt6i_protocol = cfg->fc_protocol; 1101 1102 addr_type = ipv6_addr_type(&cfg->fc_dst); 1103 1104 if (addr_type & IPV6_ADDR_MULTICAST) 1105 rt->u.dst.input = ip6_mc_input; 1106 else 1107 rt->u.dst.input = ip6_forward; 1108 1109 rt->u.dst.output = ip6_output; 1110 1111 ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len); 1112 rt->rt6i_dst.plen = cfg->fc_dst_len; 1113 if (rt->rt6i_dst.plen == 128) 1114 rt->u.dst.flags = DST_HOST; 1115 1116 #ifdef CONFIG_IPV6_SUBTREES 1117 ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len); 1118 rt->rt6i_src.plen = cfg->fc_src_len; 1119 #endif 1120 1121 rt->rt6i_metric = cfg->fc_metric; 1122 1123 /* We cannot add true routes via loopback here, 1124 they would result in kernel looping; promote them to reject routes 1125 */ 1126 if ((cfg->fc_flags & RTF_REJECT) || 1127 (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) { 1128 /* hold loopback dev/idev if we haven't done so. */ 1129 if (dev != &loopback_dev) { 1130 if (dev) { 1131 dev_put(dev); 1132 in6_dev_put(idev); 1133 } 1134 dev = &loopback_dev; 1135 dev_hold(dev); 1136 idev = in6_dev_get(dev); 1137 if (!idev) { 1138 err = -ENODEV; 1139 goto out; 1140 } 1141 } 1142 rt->u.dst.output = ip6_pkt_discard_out; 1143 rt->u.dst.input = ip6_pkt_discard; 1144 rt->u.dst.error = -ENETUNREACH; 1145 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP; 1146 goto install_route; 1147 } 1148 1149 if (cfg->fc_flags & RTF_GATEWAY) { 1150 struct in6_addr *gw_addr; 1151 int gwa_type; 1152 1153 gw_addr = &cfg->fc_gateway; 1154 ipv6_addr_copy(&rt->rt6i_gateway, gw_addr); 1155 gwa_type = ipv6_addr_type(gw_addr); 1156 1157 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) { 1158 struct rt6_info *grt; 1159 1160 /* IPv6 strictly inhibits using not link-local 1161 addresses as nexthop address. 1162 Otherwise, router will not able to send redirects. 1163 It is very good, but in some (rare!) circumstances 1164 (SIT, PtP, NBMA NOARP links) it is handy to allow 1165 some exceptions. --ANK 1166 */ 1167 err = -EINVAL; 1168 if (!(gwa_type&IPV6_ADDR_UNICAST)) 1169 goto out; 1170 1171 grt = rt6_lookup(gw_addr, NULL, cfg->fc_ifindex, 1); 1172 1173 err = -EHOSTUNREACH; 1174 if (grt == NULL) 1175 goto out; 1176 if (dev) { 1177 if (dev != grt->rt6i_dev) { 1178 dst_release(&grt->u.dst); 1179 goto out; 1180 } 1181 } else { 1182 dev = grt->rt6i_dev; 1183 idev = grt->rt6i_idev; 1184 dev_hold(dev); 1185 in6_dev_hold(grt->rt6i_idev); 1186 } 1187 if (!(grt->rt6i_flags&RTF_GATEWAY)) 1188 err = 0; 1189 dst_release(&grt->u.dst); 1190 1191 if (err) 1192 goto out; 1193 } 1194 err = -EINVAL; 1195 if (dev == NULL || (dev->flags&IFF_LOOPBACK)) 1196 goto out; 1197 } 1198 1199 err = -ENODEV; 1200 if (dev == NULL) 1201 goto out; 1202 1203 if (cfg->fc_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) { 1204 rt->rt6i_nexthop = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev); 1205 if (IS_ERR(rt->rt6i_nexthop)) { 1206 err = PTR_ERR(rt->rt6i_nexthop); 1207 rt->rt6i_nexthop = NULL; 1208 goto out; 1209 } 1210 } 1211 1212 rt->rt6i_flags = cfg->fc_flags; 1213 1214 install_route: 1215 if (cfg->fc_mx) { 1216 struct nlattr *nla; 1217 int remaining; 1218 1219 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { 1220 int type = nla->nla_type; 1221 1222 if (type) { 1223 if (type > RTAX_MAX) { 1224 err = -EINVAL; 1225 goto out; 1226 } 1227 1228 rt->u.dst.metrics[type - 1] = nla_get_u32(nla); 1229 } 1230 } 1231 } 1232 1233 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0) 1234 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1; 1235 if (!rt->u.dst.metrics[RTAX_MTU-1]) 1236 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev); 1237 if (!rt->u.dst.metrics[RTAX_ADVMSS-1]) 1238 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 1239 rt->u.dst.dev = dev; 1240 rt->rt6i_idev = idev; 1241 rt->rt6i_table = table; 1242 return __ip6_ins_rt(rt, &cfg->fc_nlinfo); 1243 1244 out: 1245 if (dev) 1246 dev_put(dev); 1247 if (idev) 1248 in6_dev_put(idev); 1249 if (rt) 1250 dst_free(&rt->u.dst); 1251 return err; 1252 } 1253 1254 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info) 1255 { 1256 int err; 1257 struct fib6_table *table; 1258 1259 if (rt == &ip6_null_entry) 1260 return -ENOENT; 1261 1262 table = rt->rt6i_table; 1263 write_lock_bh(&table->tb6_lock); 1264 1265 err = fib6_del(rt, info); 1266 dst_release(&rt->u.dst); 1267 1268 write_unlock_bh(&table->tb6_lock); 1269 1270 return err; 1271 } 1272 1273 int ip6_del_rt(struct rt6_info *rt) 1274 { 1275 return __ip6_del_rt(rt, NULL); 1276 } 1277 1278 static int ip6_route_del(struct fib6_config *cfg) 1279 { 1280 struct fib6_table *table; 1281 struct fib6_node *fn; 1282 struct rt6_info *rt; 1283 int err = -ESRCH; 1284 1285 table = fib6_get_table(cfg->fc_table); 1286 if (table == NULL) 1287 return err; 1288 1289 read_lock_bh(&table->tb6_lock); 1290 1291 fn = fib6_locate(&table->tb6_root, 1292 &cfg->fc_dst, cfg->fc_dst_len, 1293 &cfg->fc_src, cfg->fc_src_len); 1294 1295 if (fn) { 1296 for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) { 1297 if (cfg->fc_ifindex && 1298 (rt->rt6i_dev == NULL || 1299 rt->rt6i_dev->ifindex != cfg->fc_ifindex)) 1300 continue; 1301 if (cfg->fc_flags & RTF_GATEWAY && 1302 !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway)) 1303 continue; 1304 if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric) 1305 continue; 1306 dst_hold(&rt->u.dst); 1307 read_unlock_bh(&table->tb6_lock); 1308 1309 return __ip6_del_rt(rt, &cfg->fc_nlinfo); 1310 } 1311 } 1312 read_unlock_bh(&table->tb6_lock); 1313 1314 return err; 1315 } 1316 1317 /* 1318 * Handle redirects 1319 */ 1320 struct ip6rd_flowi { 1321 struct flowi fl; 1322 struct in6_addr gateway; 1323 }; 1324 1325 static struct rt6_info *__ip6_route_redirect(struct fib6_table *table, 1326 struct flowi *fl, 1327 int flags) 1328 { 1329 struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl; 1330 struct rt6_info *rt; 1331 struct fib6_node *fn; 1332 1333 /* 1334 * Get the "current" route for this destination and 1335 * check if the redirect has come from approriate router. 1336 * 1337 * RFC 2461 specifies that redirects should only be 1338 * accepted if they come from the nexthop to the target. 1339 * Due to the way the routes are chosen, this notion 1340 * is a bit fuzzy and one might need to check all possible 1341 * routes. 1342 */ 1343 1344 read_lock_bh(&table->tb6_lock); 1345 fn = fib6_lookup(&table->tb6_root, &fl->fl6_dst, &fl->fl6_src); 1346 restart: 1347 for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) { 1348 /* 1349 * Current route is on-link; redirect is always invalid. 1350 * 1351 * Seems, previous statement is not true. It could 1352 * be node, which looks for us as on-link (f.e. proxy ndisc) 1353 * But then router serving it might decide, that we should 1354 * know truth 8)8) --ANK (980726). 1355 */ 1356 if (rt6_check_expired(rt)) 1357 continue; 1358 if (!(rt->rt6i_flags & RTF_GATEWAY)) 1359 continue; 1360 if (fl->oif != rt->rt6i_dev->ifindex) 1361 continue; 1362 if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway)) 1363 continue; 1364 break; 1365 } 1366 1367 if (!rt) 1368 rt = &ip6_null_entry; 1369 BACKTRACK(&fl->fl6_src); 1370 out: 1371 dst_hold(&rt->u.dst); 1372 1373 read_unlock_bh(&table->tb6_lock); 1374 1375 return rt; 1376 }; 1377 1378 static struct rt6_info *ip6_route_redirect(struct in6_addr *dest, 1379 struct in6_addr *src, 1380 struct in6_addr *gateway, 1381 struct net_device *dev) 1382 { 1383 int flags = RT6_LOOKUP_F_HAS_SADDR; 1384 struct ip6rd_flowi rdfl = { 1385 .fl = { 1386 .oif = dev->ifindex, 1387 .nl_u = { 1388 .ip6_u = { 1389 .daddr = *dest, 1390 .saddr = *src, 1391 }, 1392 }, 1393 }, 1394 .gateway = *gateway, 1395 }; 1396 1397 if (rt6_need_strict(dest)) 1398 flags |= RT6_LOOKUP_F_IFACE; 1399 1400 return (struct rt6_info *)fib6_rule_lookup((struct flowi *)&rdfl, flags, __ip6_route_redirect); 1401 } 1402 1403 void rt6_redirect(struct in6_addr *dest, struct in6_addr *src, 1404 struct in6_addr *saddr, 1405 struct neighbour *neigh, u8 *lladdr, int on_link) 1406 { 1407 struct rt6_info *rt, *nrt = NULL; 1408 struct netevent_redirect netevent; 1409 1410 rt = ip6_route_redirect(dest, src, saddr, neigh->dev); 1411 1412 if (rt == &ip6_null_entry) { 1413 if (net_ratelimit()) 1414 printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop " 1415 "for redirect target\n"); 1416 goto out; 1417 } 1418 1419 /* 1420 * We have finally decided to accept it. 1421 */ 1422 1423 neigh_update(neigh, lladdr, NUD_STALE, 1424 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1425 NEIGH_UPDATE_F_OVERRIDE| 1426 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1427 NEIGH_UPDATE_F_ISROUTER)) 1428 ); 1429 1430 /* 1431 * Redirect received -> path was valid. 1432 * Look, redirects are sent only in response to data packets, 1433 * so that this nexthop apparently is reachable. --ANK 1434 */ 1435 dst_confirm(&rt->u.dst); 1436 1437 /* Duplicate redirect: silently ignore. */ 1438 if (neigh == rt->u.dst.neighbour) 1439 goto out; 1440 1441 nrt = ip6_rt_copy(rt); 1442 if (nrt == NULL) 1443 goto out; 1444 1445 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; 1446 if (on_link) 1447 nrt->rt6i_flags &= ~RTF_GATEWAY; 1448 1449 ipv6_addr_copy(&nrt->rt6i_dst.addr, dest); 1450 nrt->rt6i_dst.plen = 128; 1451 nrt->u.dst.flags |= DST_HOST; 1452 1453 ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key); 1454 nrt->rt6i_nexthop = neigh_clone(neigh); 1455 /* Reset pmtu, it may be better */ 1456 nrt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev); 1457 nrt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&nrt->u.dst)); 1458 1459 if (ip6_ins_rt(nrt)) 1460 goto out; 1461 1462 netevent.old = &rt->u.dst; 1463 netevent.new = &nrt->u.dst; 1464 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent); 1465 1466 if (rt->rt6i_flags&RTF_CACHE) { 1467 ip6_del_rt(rt); 1468 return; 1469 } 1470 1471 out: 1472 dst_release(&rt->u.dst); 1473 return; 1474 } 1475 1476 /* 1477 * Handle ICMP "packet too big" messages 1478 * i.e. Path MTU discovery 1479 */ 1480 1481 void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr, 1482 struct net_device *dev, u32 pmtu) 1483 { 1484 struct rt6_info *rt, *nrt; 1485 int allfrag = 0; 1486 1487 rt = rt6_lookup(daddr, saddr, dev->ifindex, 0); 1488 if (rt == NULL) 1489 return; 1490 1491 if (pmtu >= dst_mtu(&rt->u.dst)) 1492 goto out; 1493 1494 if (pmtu < IPV6_MIN_MTU) { 1495 /* 1496 * According to RFC2460, PMTU is set to the IPv6 Minimum Link 1497 * MTU (1280) and a fragment header should always be included 1498 * after a node receiving Too Big message reporting PMTU is 1499 * less than the IPv6 Minimum Link MTU. 1500 */ 1501 pmtu = IPV6_MIN_MTU; 1502 allfrag = 1; 1503 } 1504 1505 /* New mtu received -> path was valid. 1506 They are sent only in response to data packets, 1507 so that this nexthop apparently is reachable. --ANK 1508 */ 1509 dst_confirm(&rt->u.dst); 1510 1511 /* Host route. If it is static, it would be better 1512 not to override it, but add new one, so that 1513 when cache entry will expire old pmtu 1514 would return automatically. 1515 */ 1516 if (rt->rt6i_flags & RTF_CACHE) { 1517 rt->u.dst.metrics[RTAX_MTU-1] = pmtu; 1518 if (allfrag) 1519 rt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 1520 dst_set_expires(&rt->u.dst, ip6_rt_mtu_expires); 1521 rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES; 1522 goto out; 1523 } 1524 1525 /* Network route. 1526 Two cases are possible: 1527 1. It is connected route. Action: COW 1528 2. It is gatewayed route or NONEXTHOP route. Action: clone it. 1529 */ 1530 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) 1531 nrt = rt6_alloc_cow(rt, daddr, saddr); 1532 else 1533 nrt = rt6_alloc_clone(rt, daddr); 1534 1535 if (nrt) { 1536 nrt->u.dst.metrics[RTAX_MTU-1] = pmtu; 1537 if (allfrag) 1538 nrt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 1539 1540 /* According to RFC 1981, detecting PMTU increase shouldn't be 1541 * happened within 5 mins, the recommended timer is 10 mins. 1542 * Here this route expiration time is set to ip6_rt_mtu_expires 1543 * which is 10 mins. After 10 mins the decreased pmtu is expired 1544 * and detecting PMTU increase will be automatically happened. 1545 */ 1546 dst_set_expires(&nrt->u.dst, ip6_rt_mtu_expires); 1547 nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES; 1548 1549 ip6_ins_rt(nrt); 1550 } 1551 out: 1552 dst_release(&rt->u.dst); 1553 } 1554 1555 /* 1556 * Misc support functions 1557 */ 1558 1559 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort) 1560 { 1561 struct rt6_info *rt = ip6_dst_alloc(); 1562 1563 if (rt) { 1564 rt->u.dst.input = ort->u.dst.input; 1565 rt->u.dst.output = ort->u.dst.output; 1566 1567 memcpy(rt->u.dst.metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32)); 1568 rt->u.dst.error = ort->u.dst.error; 1569 rt->u.dst.dev = ort->u.dst.dev; 1570 if (rt->u.dst.dev) 1571 dev_hold(rt->u.dst.dev); 1572 rt->rt6i_idev = ort->rt6i_idev; 1573 if (rt->rt6i_idev) 1574 in6_dev_hold(rt->rt6i_idev); 1575 rt->u.dst.lastuse = jiffies; 1576 rt->rt6i_expires = 0; 1577 1578 ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway); 1579 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; 1580 rt->rt6i_metric = 0; 1581 1582 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); 1583 #ifdef CONFIG_IPV6_SUBTREES 1584 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 1585 #endif 1586 rt->rt6i_table = ort->rt6i_table; 1587 } 1588 return rt; 1589 } 1590 1591 #ifdef CONFIG_IPV6_ROUTE_INFO 1592 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen, 1593 struct in6_addr *gwaddr, int ifindex) 1594 { 1595 struct fib6_node *fn; 1596 struct rt6_info *rt = NULL; 1597 struct fib6_table *table; 1598 1599 table = fib6_get_table(RT6_TABLE_INFO); 1600 if (table == NULL) 1601 return NULL; 1602 1603 write_lock_bh(&table->tb6_lock); 1604 fn = fib6_locate(&table->tb6_root, prefix ,prefixlen, NULL, 0); 1605 if (!fn) 1606 goto out; 1607 1608 for (rt = fn->leaf; rt; rt = rt->u.dst.rt6_next) { 1609 if (rt->rt6i_dev->ifindex != ifindex) 1610 continue; 1611 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY)) 1612 continue; 1613 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr)) 1614 continue; 1615 dst_hold(&rt->u.dst); 1616 break; 1617 } 1618 out: 1619 write_unlock_bh(&table->tb6_lock); 1620 return rt; 1621 } 1622 1623 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen, 1624 struct in6_addr *gwaddr, int ifindex, 1625 unsigned pref) 1626 { 1627 struct fib6_config cfg = { 1628 .fc_table = RT6_TABLE_INFO, 1629 .fc_metric = 1024, 1630 .fc_ifindex = ifindex, 1631 .fc_dst_len = prefixlen, 1632 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | 1633 RTF_UP | RTF_PREF(pref), 1634 }; 1635 1636 ipv6_addr_copy(&cfg.fc_dst, prefix); 1637 ipv6_addr_copy(&cfg.fc_gateway, gwaddr); 1638 1639 /* We should treat it as a default route if prefix length is 0. */ 1640 if (!prefixlen) 1641 cfg.fc_flags |= RTF_DEFAULT; 1642 1643 ip6_route_add(&cfg); 1644 1645 return rt6_get_route_info(prefix, prefixlen, gwaddr, ifindex); 1646 } 1647 #endif 1648 1649 struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *dev) 1650 { 1651 struct rt6_info *rt; 1652 struct fib6_table *table; 1653 1654 table = fib6_get_table(RT6_TABLE_DFLT); 1655 if (table == NULL) 1656 return NULL; 1657 1658 write_lock_bh(&table->tb6_lock); 1659 for (rt = table->tb6_root.leaf; rt; rt=rt->u.dst.rt6_next) { 1660 if (dev == rt->rt6i_dev && 1661 ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && 1662 ipv6_addr_equal(&rt->rt6i_gateway, addr)) 1663 break; 1664 } 1665 if (rt) 1666 dst_hold(&rt->u.dst); 1667 write_unlock_bh(&table->tb6_lock); 1668 return rt; 1669 } 1670 1671 struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr, 1672 struct net_device *dev, 1673 unsigned int pref) 1674 { 1675 struct fib6_config cfg = { 1676 .fc_table = RT6_TABLE_DFLT, 1677 .fc_metric = 1024, 1678 .fc_ifindex = dev->ifindex, 1679 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | 1680 RTF_UP | RTF_EXPIRES | RTF_PREF(pref), 1681 }; 1682 1683 ipv6_addr_copy(&cfg.fc_gateway, gwaddr); 1684 1685 ip6_route_add(&cfg); 1686 1687 return rt6_get_dflt_router(gwaddr, dev); 1688 } 1689 1690 void rt6_purge_dflt_routers(void) 1691 { 1692 struct rt6_info *rt; 1693 struct fib6_table *table; 1694 1695 /* NOTE: Keep consistent with rt6_get_dflt_router */ 1696 table = fib6_get_table(RT6_TABLE_DFLT); 1697 if (table == NULL) 1698 return; 1699 1700 restart: 1701 read_lock_bh(&table->tb6_lock); 1702 for (rt = table->tb6_root.leaf; rt; rt = rt->u.dst.rt6_next) { 1703 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) { 1704 dst_hold(&rt->u.dst); 1705 read_unlock_bh(&table->tb6_lock); 1706 ip6_del_rt(rt); 1707 goto restart; 1708 } 1709 } 1710 read_unlock_bh(&table->tb6_lock); 1711 } 1712 1713 static void rtmsg_to_fib6_config(struct in6_rtmsg *rtmsg, 1714 struct fib6_config *cfg) 1715 { 1716 memset(cfg, 0, sizeof(*cfg)); 1717 1718 cfg->fc_table = RT6_TABLE_MAIN; 1719 cfg->fc_ifindex = rtmsg->rtmsg_ifindex; 1720 cfg->fc_metric = rtmsg->rtmsg_metric; 1721 cfg->fc_expires = rtmsg->rtmsg_info; 1722 cfg->fc_dst_len = rtmsg->rtmsg_dst_len; 1723 cfg->fc_src_len = rtmsg->rtmsg_src_len; 1724 cfg->fc_flags = rtmsg->rtmsg_flags; 1725 1726 ipv6_addr_copy(&cfg->fc_dst, &rtmsg->rtmsg_dst); 1727 ipv6_addr_copy(&cfg->fc_src, &rtmsg->rtmsg_src); 1728 ipv6_addr_copy(&cfg->fc_gateway, &rtmsg->rtmsg_gateway); 1729 } 1730 1731 int ipv6_route_ioctl(unsigned int cmd, void __user *arg) 1732 { 1733 struct fib6_config cfg; 1734 struct in6_rtmsg rtmsg; 1735 int err; 1736 1737 switch(cmd) { 1738 case SIOCADDRT: /* Add a route */ 1739 case SIOCDELRT: /* Delete a route */ 1740 if (!capable(CAP_NET_ADMIN)) 1741 return -EPERM; 1742 err = copy_from_user(&rtmsg, arg, 1743 sizeof(struct in6_rtmsg)); 1744 if (err) 1745 return -EFAULT; 1746 1747 rtmsg_to_fib6_config(&rtmsg, &cfg); 1748 1749 rtnl_lock(); 1750 switch (cmd) { 1751 case SIOCADDRT: 1752 err = ip6_route_add(&cfg); 1753 break; 1754 case SIOCDELRT: 1755 err = ip6_route_del(&cfg); 1756 break; 1757 default: 1758 err = -EINVAL; 1759 } 1760 rtnl_unlock(); 1761 1762 return err; 1763 } 1764 1765 return -EINVAL; 1766 } 1767 1768 /* 1769 * Drop the packet on the floor 1770 */ 1771 1772 static inline int ip6_pkt_drop(struct sk_buff *skb, int code, 1773 int ipstats_mib_noroutes) 1774 { 1775 int type; 1776 switch (ipstats_mib_noroutes) { 1777 case IPSTATS_MIB_INNOROUTES: 1778 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr); 1779 if (type == IPV6_ADDR_ANY || type == IPV6_ADDR_RESERVED) { 1780 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INADDRERRORS); 1781 break; 1782 } 1783 /* FALLTHROUGH */ 1784 case IPSTATS_MIB_OUTNOROUTES: 1785 IP6_INC_STATS(ip6_dst_idev(skb->dst), ipstats_mib_noroutes); 1786 break; 1787 } 1788 icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0, skb->dev); 1789 kfree_skb(skb); 1790 return 0; 1791 } 1792 1793 static int ip6_pkt_discard(struct sk_buff *skb) 1794 { 1795 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES); 1796 } 1797 1798 static int ip6_pkt_discard_out(struct sk_buff *skb) 1799 { 1800 skb->dev = skb->dst->dev; 1801 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES); 1802 } 1803 1804 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 1805 1806 static int ip6_pkt_prohibit(struct sk_buff *skb) 1807 { 1808 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES); 1809 } 1810 1811 static int ip6_pkt_prohibit_out(struct sk_buff *skb) 1812 { 1813 skb->dev = skb->dst->dev; 1814 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES); 1815 } 1816 1817 static int ip6_pkt_blk_hole(struct sk_buff *skb) 1818 { 1819 kfree_skb(skb); 1820 return 0; 1821 } 1822 1823 #endif 1824 1825 /* 1826 * Allocate a dst for local (unicast / anycast) address. 1827 */ 1828 1829 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev, 1830 const struct in6_addr *addr, 1831 int anycast) 1832 { 1833 struct rt6_info *rt = ip6_dst_alloc(); 1834 1835 if (rt == NULL) 1836 return ERR_PTR(-ENOMEM); 1837 1838 dev_hold(&loopback_dev); 1839 in6_dev_hold(idev); 1840 1841 rt->u.dst.flags = DST_HOST; 1842 rt->u.dst.input = ip6_input; 1843 rt->u.dst.output = ip6_output; 1844 rt->rt6i_dev = &loopback_dev; 1845 rt->rt6i_idev = idev; 1846 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev); 1847 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 1848 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1; 1849 rt->u.dst.obsolete = -1; 1850 1851 rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP; 1852 if (anycast) 1853 rt->rt6i_flags |= RTF_ANYCAST; 1854 else 1855 rt->rt6i_flags |= RTF_LOCAL; 1856 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway); 1857 if (rt->rt6i_nexthop == NULL) { 1858 dst_free(&rt->u.dst); 1859 return ERR_PTR(-ENOMEM); 1860 } 1861 1862 ipv6_addr_copy(&rt->rt6i_dst.addr, addr); 1863 rt->rt6i_dst.plen = 128; 1864 rt->rt6i_table = fib6_get_table(RT6_TABLE_LOCAL); 1865 1866 atomic_set(&rt->u.dst.__refcnt, 1); 1867 1868 return rt; 1869 } 1870 1871 static int fib6_ifdown(struct rt6_info *rt, void *arg) 1872 { 1873 if (((void*)rt->rt6i_dev == arg || arg == NULL) && 1874 rt != &ip6_null_entry) { 1875 RT6_TRACE("deleted by ifdown %p\n", rt); 1876 return -1; 1877 } 1878 return 0; 1879 } 1880 1881 void rt6_ifdown(struct net_device *dev) 1882 { 1883 fib6_clean_all(fib6_ifdown, 0, dev); 1884 } 1885 1886 struct rt6_mtu_change_arg 1887 { 1888 struct net_device *dev; 1889 unsigned mtu; 1890 }; 1891 1892 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg) 1893 { 1894 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; 1895 struct inet6_dev *idev; 1896 1897 /* In IPv6 pmtu discovery is not optional, 1898 so that RTAX_MTU lock cannot disable it. 1899 We still use this lock to block changes 1900 caused by addrconf/ndisc. 1901 */ 1902 1903 idev = __in6_dev_get(arg->dev); 1904 if (idev == NULL) 1905 return 0; 1906 1907 /* For administrative MTU increase, there is no way to discover 1908 IPv6 PMTU increase, so PMTU increase should be updated here. 1909 Since RFC 1981 doesn't include administrative MTU increase 1910 update PMTU increase is a MUST. (i.e. jumbo frame) 1911 */ 1912 /* 1913 If new MTU is less than route PMTU, this new MTU will be the 1914 lowest MTU in the path, update the route PMTU to reflect PMTU 1915 decreases; if new MTU is greater than route PMTU, and the 1916 old MTU is the lowest MTU in the path, update the route PMTU 1917 to reflect the increase. In this case if the other nodes' MTU 1918 also have the lowest MTU, TOO BIG MESSAGE will be lead to 1919 PMTU discouvery. 1920 */ 1921 if (rt->rt6i_dev == arg->dev && 1922 !dst_metric_locked(&rt->u.dst, RTAX_MTU) && 1923 (dst_mtu(&rt->u.dst) > arg->mtu || 1924 (dst_mtu(&rt->u.dst) < arg->mtu && 1925 dst_mtu(&rt->u.dst) == idev->cnf.mtu6))) 1926 rt->u.dst.metrics[RTAX_MTU-1] = arg->mtu; 1927 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu); 1928 return 0; 1929 } 1930 1931 void rt6_mtu_change(struct net_device *dev, unsigned mtu) 1932 { 1933 struct rt6_mtu_change_arg arg = { 1934 .dev = dev, 1935 .mtu = mtu, 1936 }; 1937 1938 fib6_clean_all(rt6_mtu_change_route, 0, &arg); 1939 } 1940 1941 static struct nla_policy rtm_ipv6_policy[RTA_MAX+1] __read_mostly = { 1942 [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) }, 1943 [RTA_OIF] = { .type = NLA_U32 }, 1944 [RTA_IIF] = { .type = NLA_U32 }, 1945 [RTA_PRIORITY] = { .type = NLA_U32 }, 1946 [RTA_METRICS] = { .type = NLA_NESTED }, 1947 }; 1948 1949 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 1950 struct fib6_config *cfg) 1951 { 1952 struct rtmsg *rtm; 1953 struct nlattr *tb[RTA_MAX+1]; 1954 int err; 1955 1956 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy); 1957 if (err < 0) 1958 goto errout; 1959 1960 err = -EINVAL; 1961 rtm = nlmsg_data(nlh); 1962 memset(cfg, 0, sizeof(*cfg)); 1963 1964 cfg->fc_table = rtm->rtm_table; 1965 cfg->fc_dst_len = rtm->rtm_dst_len; 1966 cfg->fc_src_len = rtm->rtm_src_len; 1967 cfg->fc_flags = RTF_UP; 1968 cfg->fc_protocol = rtm->rtm_protocol; 1969 1970 if (rtm->rtm_type == RTN_UNREACHABLE) 1971 cfg->fc_flags |= RTF_REJECT; 1972 1973 cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid; 1974 cfg->fc_nlinfo.nlh = nlh; 1975 1976 if (tb[RTA_GATEWAY]) { 1977 nla_memcpy(&cfg->fc_gateway, tb[RTA_GATEWAY], 16); 1978 cfg->fc_flags |= RTF_GATEWAY; 1979 } 1980 1981 if (tb[RTA_DST]) { 1982 int plen = (rtm->rtm_dst_len + 7) >> 3; 1983 1984 if (nla_len(tb[RTA_DST]) < plen) 1985 goto errout; 1986 1987 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen); 1988 } 1989 1990 if (tb[RTA_SRC]) { 1991 int plen = (rtm->rtm_src_len + 7) >> 3; 1992 1993 if (nla_len(tb[RTA_SRC]) < plen) 1994 goto errout; 1995 1996 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen); 1997 } 1998 1999 if (tb[RTA_OIF]) 2000 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]); 2001 2002 if (tb[RTA_PRIORITY]) 2003 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]); 2004 2005 if (tb[RTA_METRICS]) { 2006 cfg->fc_mx = nla_data(tb[RTA_METRICS]); 2007 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]); 2008 } 2009 2010 if (tb[RTA_TABLE]) 2011 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]); 2012 2013 err = 0; 2014 errout: 2015 return err; 2016 } 2017 2018 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 2019 { 2020 struct fib6_config cfg; 2021 int err; 2022 2023 err = rtm_to_fib6_config(skb, nlh, &cfg); 2024 if (err < 0) 2025 return err; 2026 2027 return ip6_route_del(&cfg); 2028 } 2029 2030 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 2031 { 2032 struct fib6_config cfg; 2033 int err; 2034 2035 err = rtm_to_fib6_config(skb, nlh, &cfg); 2036 if (err < 0) 2037 return err; 2038 2039 return ip6_route_add(&cfg); 2040 } 2041 2042 static inline size_t rt6_nlmsg_size(void) 2043 { 2044 return NLMSG_ALIGN(sizeof(struct rtmsg)) 2045 + nla_total_size(16) /* RTA_SRC */ 2046 + nla_total_size(16) /* RTA_DST */ 2047 + nla_total_size(16) /* RTA_GATEWAY */ 2048 + nla_total_size(16) /* RTA_PREFSRC */ 2049 + nla_total_size(4) /* RTA_TABLE */ 2050 + nla_total_size(4) /* RTA_IIF */ 2051 + nla_total_size(4) /* RTA_OIF */ 2052 + nla_total_size(4) /* RTA_PRIORITY */ 2053 + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */ 2054 + nla_total_size(sizeof(struct rta_cacheinfo)); 2055 } 2056 2057 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt, 2058 struct in6_addr *dst, struct in6_addr *src, 2059 int iif, int type, u32 pid, u32 seq, 2060 int prefix, unsigned int flags) 2061 { 2062 struct rtmsg *rtm; 2063 struct nlmsghdr *nlh; 2064 long expires; 2065 u32 table; 2066 2067 if (prefix) { /* user wants prefix routes only */ 2068 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) { 2069 /* success since this is not a prefix route */ 2070 return 1; 2071 } 2072 } 2073 2074 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*rtm), flags); 2075 if (nlh == NULL) 2076 return -EMSGSIZE; 2077 2078 rtm = nlmsg_data(nlh); 2079 rtm->rtm_family = AF_INET6; 2080 rtm->rtm_dst_len = rt->rt6i_dst.plen; 2081 rtm->rtm_src_len = rt->rt6i_src.plen; 2082 rtm->rtm_tos = 0; 2083 if (rt->rt6i_table) 2084 table = rt->rt6i_table->tb6_id; 2085 else 2086 table = RT6_TABLE_UNSPEC; 2087 rtm->rtm_table = table; 2088 NLA_PUT_U32(skb, RTA_TABLE, table); 2089 if (rt->rt6i_flags&RTF_REJECT) 2090 rtm->rtm_type = RTN_UNREACHABLE; 2091 else if (rt->rt6i_dev && (rt->rt6i_dev->flags&IFF_LOOPBACK)) 2092 rtm->rtm_type = RTN_LOCAL; 2093 else 2094 rtm->rtm_type = RTN_UNICAST; 2095 rtm->rtm_flags = 0; 2096 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 2097 rtm->rtm_protocol = rt->rt6i_protocol; 2098 if (rt->rt6i_flags&RTF_DYNAMIC) 2099 rtm->rtm_protocol = RTPROT_REDIRECT; 2100 else if (rt->rt6i_flags & RTF_ADDRCONF) 2101 rtm->rtm_protocol = RTPROT_KERNEL; 2102 else if (rt->rt6i_flags&RTF_DEFAULT) 2103 rtm->rtm_protocol = RTPROT_RA; 2104 2105 if (rt->rt6i_flags&RTF_CACHE) 2106 rtm->rtm_flags |= RTM_F_CLONED; 2107 2108 if (dst) { 2109 NLA_PUT(skb, RTA_DST, 16, dst); 2110 rtm->rtm_dst_len = 128; 2111 } else if (rtm->rtm_dst_len) 2112 NLA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr); 2113 #ifdef CONFIG_IPV6_SUBTREES 2114 if (src) { 2115 NLA_PUT(skb, RTA_SRC, 16, src); 2116 rtm->rtm_src_len = 128; 2117 } else if (rtm->rtm_src_len) 2118 NLA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr); 2119 #endif 2120 if (iif) 2121 NLA_PUT_U32(skb, RTA_IIF, iif); 2122 else if (dst) { 2123 struct in6_addr saddr_buf; 2124 if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0) 2125 NLA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); 2126 } 2127 2128 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0) 2129 goto nla_put_failure; 2130 2131 if (rt->u.dst.neighbour) 2132 NLA_PUT(skb, RTA_GATEWAY, 16, &rt->u.dst.neighbour->primary_key); 2133 2134 if (rt->u.dst.dev) 2135 NLA_PUT_U32(skb, RTA_OIF, rt->rt6i_dev->ifindex); 2136 2137 NLA_PUT_U32(skb, RTA_PRIORITY, rt->rt6i_metric); 2138 2139 expires = rt->rt6i_expires ? rt->rt6i_expires - jiffies : 0; 2140 if (rtnl_put_cacheinfo(skb, &rt->u.dst, 0, 0, 0, 2141 expires, rt->u.dst.error) < 0) 2142 goto nla_put_failure; 2143 2144 return nlmsg_end(skb, nlh); 2145 2146 nla_put_failure: 2147 nlmsg_cancel(skb, nlh); 2148 return -EMSGSIZE; 2149 } 2150 2151 int rt6_dump_route(struct rt6_info *rt, void *p_arg) 2152 { 2153 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; 2154 int prefix; 2155 2156 if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) { 2157 struct rtmsg *rtm = nlmsg_data(arg->cb->nlh); 2158 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0; 2159 } else 2160 prefix = 0; 2161 2162 return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE, 2163 NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq, 2164 prefix, NLM_F_MULTI); 2165 } 2166 2167 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 2168 { 2169 struct nlattr *tb[RTA_MAX+1]; 2170 struct rt6_info *rt; 2171 struct sk_buff *skb; 2172 struct rtmsg *rtm; 2173 struct flowi fl; 2174 int err, iif = 0; 2175 2176 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy); 2177 if (err < 0) 2178 goto errout; 2179 2180 err = -EINVAL; 2181 memset(&fl, 0, sizeof(fl)); 2182 2183 if (tb[RTA_SRC]) { 2184 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr)) 2185 goto errout; 2186 2187 ipv6_addr_copy(&fl.fl6_src, nla_data(tb[RTA_SRC])); 2188 } 2189 2190 if (tb[RTA_DST]) { 2191 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr)) 2192 goto errout; 2193 2194 ipv6_addr_copy(&fl.fl6_dst, nla_data(tb[RTA_DST])); 2195 } 2196 2197 if (tb[RTA_IIF]) 2198 iif = nla_get_u32(tb[RTA_IIF]); 2199 2200 if (tb[RTA_OIF]) 2201 fl.oif = nla_get_u32(tb[RTA_OIF]); 2202 2203 if (iif) { 2204 struct net_device *dev; 2205 dev = __dev_get_by_index(iif); 2206 if (!dev) { 2207 err = -ENODEV; 2208 goto errout; 2209 } 2210 } 2211 2212 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 2213 if (skb == NULL) { 2214 err = -ENOBUFS; 2215 goto errout; 2216 } 2217 2218 /* Reserve room for dummy headers, this skb can pass 2219 through good chunk of routing engine. 2220 */ 2221 skb_reset_mac_header(skb); 2222 skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr)); 2223 2224 rt = (struct rt6_info*) ip6_route_output(NULL, &fl); 2225 skb->dst = &rt->u.dst; 2226 2227 err = rt6_fill_node(skb, rt, &fl.fl6_dst, &fl.fl6_src, iif, 2228 RTM_NEWROUTE, NETLINK_CB(in_skb).pid, 2229 nlh->nlmsg_seq, 0, 0); 2230 if (err < 0) { 2231 kfree_skb(skb); 2232 goto errout; 2233 } 2234 2235 err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid); 2236 errout: 2237 return err; 2238 } 2239 2240 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info) 2241 { 2242 struct sk_buff *skb; 2243 u32 pid = 0, seq = 0; 2244 struct nlmsghdr *nlh = NULL; 2245 int err = -ENOBUFS; 2246 2247 if (info) { 2248 pid = info->pid; 2249 nlh = info->nlh; 2250 if (nlh) 2251 seq = nlh->nlmsg_seq; 2252 } 2253 2254 skb = nlmsg_new(rt6_nlmsg_size(), gfp_any()); 2255 if (skb == NULL) 2256 goto errout; 2257 2258 err = rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0); 2259 if (err < 0) { 2260 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 2261 WARN_ON(err == -EMSGSIZE); 2262 kfree_skb(skb); 2263 goto errout; 2264 } 2265 err = rtnl_notify(skb, pid, RTNLGRP_IPV6_ROUTE, nlh, gfp_any()); 2266 errout: 2267 if (err < 0) 2268 rtnl_set_sk_err(RTNLGRP_IPV6_ROUTE, err); 2269 } 2270 2271 /* 2272 * /proc 2273 */ 2274 2275 #ifdef CONFIG_PROC_FS 2276 2277 #define RT6_INFO_LEN (32 + 4 + 32 + 4 + 32 + 40 + 5 + 1) 2278 2279 struct rt6_proc_arg 2280 { 2281 char *buffer; 2282 int offset; 2283 int length; 2284 int skip; 2285 int len; 2286 }; 2287 2288 static int rt6_info_route(struct rt6_info *rt, void *p_arg) 2289 { 2290 struct rt6_proc_arg *arg = (struct rt6_proc_arg *) p_arg; 2291 2292 if (arg->skip < arg->offset / RT6_INFO_LEN) { 2293 arg->skip++; 2294 return 0; 2295 } 2296 2297 if (arg->len >= arg->length) 2298 return 0; 2299 2300 arg->len += sprintf(arg->buffer + arg->len, 2301 NIP6_SEQFMT " %02x ", 2302 NIP6(rt->rt6i_dst.addr), 2303 rt->rt6i_dst.plen); 2304 2305 #ifdef CONFIG_IPV6_SUBTREES 2306 arg->len += sprintf(arg->buffer + arg->len, 2307 NIP6_SEQFMT " %02x ", 2308 NIP6(rt->rt6i_src.addr), 2309 rt->rt6i_src.plen); 2310 #else 2311 arg->len += sprintf(arg->buffer + arg->len, 2312 "00000000000000000000000000000000 00 "); 2313 #endif 2314 2315 if (rt->rt6i_nexthop) { 2316 arg->len += sprintf(arg->buffer + arg->len, 2317 NIP6_SEQFMT, 2318 NIP6(*((struct in6_addr *)rt->rt6i_nexthop->primary_key))); 2319 } else { 2320 arg->len += sprintf(arg->buffer + arg->len, 2321 "00000000000000000000000000000000"); 2322 } 2323 arg->len += sprintf(arg->buffer + arg->len, 2324 " %08x %08x %08x %08x %8s\n", 2325 rt->rt6i_metric, atomic_read(&rt->u.dst.__refcnt), 2326 rt->u.dst.__use, rt->rt6i_flags, 2327 rt->rt6i_dev ? rt->rt6i_dev->name : ""); 2328 return 0; 2329 } 2330 2331 static int rt6_proc_info(char *buffer, char **start, off_t offset, int length) 2332 { 2333 struct rt6_proc_arg arg = { 2334 .buffer = buffer, 2335 .offset = offset, 2336 .length = length, 2337 }; 2338 2339 fib6_clean_all(rt6_info_route, 0, &arg); 2340 2341 *start = buffer; 2342 if (offset) 2343 *start += offset % RT6_INFO_LEN; 2344 2345 arg.len -= offset % RT6_INFO_LEN; 2346 2347 if (arg.len > length) 2348 arg.len = length; 2349 if (arg.len < 0) 2350 arg.len = 0; 2351 2352 return arg.len; 2353 } 2354 2355 static int rt6_stats_seq_show(struct seq_file *seq, void *v) 2356 { 2357 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", 2358 rt6_stats.fib_nodes, rt6_stats.fib_route_nodes, 2359 rt6_stats.fib_rt_alloc, rt6_stats.fib_rt_entries, 2360 rt6_stats.fib_rt_cache, 2361 atomic_read(&ip6_dst_ops.entries), 2362 rt6_stats.fib_discarded_routes); 2363 2364 return 0; 2365 } 2366 2367 static int rt6_stats_seq_open(struct inode *inode, struct file *file) 2368 { 2369 return single_open(file, rt6_stats_seq_show, NULL); 2370 } 2371 2372 static const struct file_operations rt6_stats_seq_fops = { 2373 .owner = THIS_MODULE, 2374 .open = rt6_stats_seq_open, 2375 .read = seq_read, 2376 .llseek = seq_lseek, 2377 .release = single_release, 2378 }; 2379 #endif /* CONFIG_PROC_FS */ 2380 2381 #ifdef CONFIG_SYSCTL 2382 2383 static int flush_delay; 2384 2385 static 2386 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, struct file * filp, 2387 void __user *buffer, size_t *lenp, loff_t *ppos) 2388 { 2389 if (write) { 2390 proc_dointvec(ctl, write, filp, buffer, lenp, ppos); 2391 fib6_run_gc(flush_delay <= 0 ? ~0UL : (unsigned long)flush_delay); 2392 return 0; 2393 } else 2394 return -EINVAL; 2395 } 2396 2397 ctl_table ipv6_route_table[] = { 2398 { 2399 .ctl_name = NET_IPV6_ROUTE_FLUSH, 2400 .procname = "flush", 2401 .data = &flush_delay, 2402 .maxlen = sizeof(int), 2403 .mode = 0200, 2404 .proc_handler = &ipv6_sysctl_rtcache_flush 2405 }, 2406 { 2407 .ctl_name = NET_IPV6_ROUTE_GC_THRESH, 2408 .procname = "gc_thresh", 2409 .data = &ip6_dst_ops.gc_thresh, 2410 .maxlen = sizeof(int), 2411 .mode = 0644, 2412 .proc_handler = &proc_dointvec, 2413 }, 2414 { 2415 .ctl_name = NET_IPV6_ROUTE_MAX_SIZE, 2416 .procname = "max_size", 2417 .data = &ip6_rt_max_size, 2418 .maxlen = sizeof(int), 2419 .mode = 0644, 2420 .proc_handler = &proc_dointvec, 2421 }, 2422 { 2423 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL, 2424 .procname = "gc_min_interval", 2425 .data = &ip6_rt_gc_min_interval, 2426 .maxlen = sizeof(int), 2427 .mode = 0644, 2428 .proc_handler = &proc_dointvec_jiffies, 2429 .strategy = &sysctl_jiffies, 2430 }, 2431 { 2432 .ctl_name = NET_IPV6_ROUTE_GC_TIMEOUT, 2433 .procname = "gc_timeout", 2434 .data = &ip6_rt_gc_timeout, 2435 .maxlen = sizeof(int), 2436 .mode = 0644, 2437 .proc_handler = &proc_dointvec_jiffies, 2438 .strategy = &sysctl_jiffies, 2439 }, 2440 { 2441 .ctl_name = NET_IPV6_ROUTE_GC_INTERVAL, 2442 .procname = "gc_interval", 2443 .data = &ip6_rt_gc_interval, 2444 .maxlen = sizeof(int), 2445 .mode = 0644, 2446 .proc_handler = &proc_dointvec_jiffies, 2447 .strategy = &sysctl_jiffies, 2448 }, 2449 { 2450 .ctl_name = NET_IPV6_ROUTE_GC_ELASTICITY, 2451 .procname = "gc_elasticity", 2452 .data = &ip6_rt_gc_elasticity, 2453 .maxlen = sizeof(int), 2454 .mode = 0644, 2455 .proc_handler = &proc_dointvec_jiffies, 2456 .strategy = &sysctl_jiffies, 2457 }, 2458 { 2459 .ctl_name = NET_IPV6_ROUTE_MTU_EXPIRES, 2460 .procname = "mtu_expires", 2461 .data = &ip6_rt_mtu_expires, 2462 .maxlen = sizeof(int), 2463 .mode = 0644, 2464 .proc_handler = &proc_dointvec_jiffies, 2465 .strategy = &sysctl_jiffies, 2466 }, 2467 { 2468 .ctl_name = NET_IPV6_ROUTE_MIN_ADVMSS, 2469 .procname = "min_adv_mss", 2470 .data = &ip6_rt_min_advmss, 2471 .maxlen = sizeof(int), 2472 .mode = 0644, 2473 .proc_handler = &proc_dointvec_jiffies, 2474 .strategy = &sysctl_jiffies, 2475 }, 2476 { 2477 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL_MS, 2478 .procname = "gc_min_interval_ms", 2479 .data = &ip6_rt_gc_min_interval, 2480 .maxlen = sizeof(int), 2481 .mode = 0644, 2482 .proc_handler = &proc_dointvec_ms_jiffies, 2483 .strategy = &sysctl_ms_jiffies, 2484 }, 2485 { .ctl_name = 0 } 2486 }; 2487 2488 #endif 2489 2490 void __init ip6_route_init(void) 2491 { 2492 #ifdef CONFIG_PROC_FS 2493 struct proc_dir_entry *p; 2494 #endif 2495 ip6_dst_ops.kmem_cachep = 2496 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0, 2497 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL); 2498 fib6_init(); 2499 #ifdef CONFIG_PROC_FS 2500 p = proc_net_create("ipv6_route", 0, rt6_proc_info); 2501 if (p) 2502 p->owner = THIS_MODULE; 2503 2504 proc_net_fops_create("rt6_stats", S_IRUGO, &rt6_stats_seq_fops); 2505 #endif 2506 #ifdef CONFIG_XFRM 2507 xfrm6_init(); 2508 #endif 2509 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2510 fib6_rules_init(); 2511 #endif 2512 2513 __rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL); 2514 __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL); 2515 __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL); 2516 } 2517 2518 void ip6_route_cleanup(void) 2519 { 2520 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 2521 fib6_rules_cleanup(); 2522 #endif 2523 #ifdef CONFIG_PROC_FS 2524 proc_net_remove("ipv6_route"); 2525 proc_net_remove("rt6_stats"); 2526 #endif 2527 #ifdef CONFIG_XFRM 2528 xfrm6_fini(); 2529 #endif 2530 rt6_ifdown(NULL); 2531 fib6_gc_cleanup(); 2532 kmem_cache_destroy(ip6_dst_ops.kmem_cachep); 2533 } 2534