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 */ 26 27 #include <linux/capability.h> 28 #include <linux/errno.h> 29 #include <linux/types.h> 30 #include <linux/times.h> 31 #include <linux/socket.h> 32 #include <linux/sockios.h> 33 #include <linux/net.h> 34 #include <linux/route.h> 35 #include <linux/netdevice.h> 36 #include <linux/in6.h> 37 #include <linux/init.h> 38 #include <linux/netlink.h> 39 #include <linux/if_arp.h> 40 41 #ifdef CONFIG_PROC_FS 42 #include <linux/proc_fs.h> 43 #include <linux/seq_file.h> 44 #endif 45 46 #include <net/snmp.h> 47 #include <net/ipv6.h> 48 #include <net/ip6_fib.h> 49 #include <net/ip6_route.h> 50 #include <net/ndisc.h> 51 #include <net/addrconf.h> 52 #include <net/tcp.h> 53 #include <linux/rtnetlink.h> 54 #include <net/dst.h> 55 #include <net/xfrm.h> 56 #include <net/netevent.h> 57 58 #include <asm/uaccess.h> 59 60 #ifdef CONFIG_SYSCTL 61 #include <linux/sysctl.h> 62 #endif 63 64 /* Set to 3 to get tracing. */ 65 #define RT6_DEBUG 2 66 67 #if RT6_DEBUG >= 3 68 #define RDBG(x) printk x 69 #define RT6_TRACE(x...) printk(KERN_DEBUG x) 70 #else 71 #define RDBG(x) 72 #define RT6_TRACE(x...) do { ; } while (0) 73 #endif 74 75 #define CLONE_OFFLINK_ROUTE 0 76 77 #define RT6_SELECT_F_IFACE 0x1 78 #define RT6_SELECT_F_REACHABLE 0x2 79 80 static int ip6_rt_max_size = 4096; 81 static int ip6_rt_gc_min_interval = HZ / 2; 82 static int ip6_rt_gc_timeout = 60*HZ; 83 int ip6_rt_gc_interval = 30*HZ; 84 static int ip6_rt_gc_elasticity = 9; 85 static int ip6_rt_mtu_expires = 10*60*HZ; 86 static int ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; 87 88 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort); 89 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); 90 static struct dst_entry *ip6_negative_advice(struct dst_entry *); 91 static void ip6_dst_destroy(struct dst_entry *); 92 static void ip6_dst_ifdown(struct dst_entry *, 93 struct net_device *dev, int how); 94 static int ip6_dst_gc(void); 95 96 static int ip6_pkt_discard(struct sk_buff *skb); 97 static int ip6_pkt_discard_out(struct sk_buff *skb); 98 static void ip6_link_failure(struct sk_buff *skb); 99 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu); 100 101 #ifdef CONFIG_IPV6_ROUTE_INFO 102 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen, 103 struct in6_addr *gwaddr, int ifindex, 104 unsigned pref); 105 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen, 106 struct in6_addr *gwaddr, int ifindex); 107 #endif 108 109 static struct dst_ops ip6_dst_ops = { 110 .family = AF_INET6, 111 .protocol = __constant_htons(ETH_P_IPV6), 112 .gc = ip6_dst_gc, 113 .gc_thresh = 1024, 114 .check = ip6_dst_check, 115 .destroy = ip6_dst_destroy, 116 .ifdown = ip6_dst_ifdown, 117 .negative_advice = ip6_negative_advice, 118 .link_failure = ip6_link_failure, 119 .update_pmtu = ip6_rt_update_pmtu, 120 .entry_size = sizeof(struct rt6_info), 121 }; 122 123 struct rt6_info ip6_null_entry = { 124 .u = { 125 .dst = { 126 .__refcnt = ATOMIC_INIT(1), 127 .__use = 1, 128 .dev = &loopback_dev, 129 .obsolete = -1, 130 .error = -ENETUNREACH, 131 .metrics = { [RTAX_HOPLIMIT - 1] = 255, }, 132 .input = ip6_pkt_discard, 133 .output = ip6_pkt_discard_out, 134 .ops = &ip6_dst_ops, 135 .path = (struct dst_entry*)&ip6_null_entry, 136 } 137 }, 138 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 139 .rt6i_metric = ~(u32) 0, 140 .rt6i_ref = ATOMIC_INIT(1), 141 }; 142 143 struct fib6_node ip6_routing_table = { 144 .leaf = &ip6_null_entry, 145 .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO, 146 }; 147 148 /* Protects all the ip6 fib */ 149 150 DEFINE_RWLOCK(rt6_lock); 151 152 153 /* allocate dst with ip6_dst_ops */ 154 static __inline__ struct rt6_info *ip6_dst_alloc(void) 155 { 156 return (struct rt6_info *)dst_alloc(&ip6_dst_ops); 157 } 158 159 static void ip6_dst_destroy(struct dst_entry *dst) 160 { 161 struct rt6_info *rt = (struct rt6_info *)dst; 162 struct inet6_dev *idev = rt->rt6i_idev; 163 164 if (idev != NULL) { 165 rt->rt6i_idev = NULL; 166 in6_dev_put(idev); 167 } 168 } 169 170 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 171 int how) 172 { 173 struct rt6_info *rt = (struct rt6_info *)dst; 174 struct inet6_dev *idev = rt->rt6i_idev; 175 176 if (dev != &loopback_dev && idev != NULL && idev->dev == dev) { 177 struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev); 178 if (loopback_idev != NULL) { 179 rt->rt6i_idev = loopback_idev; 180 in6_dev_put(idev); 181 } 182 } 183 } 184 185 static __inline__ int rt6_check_expired(const struct rt6_info *rt) 186 { 187 return (rt->rt6i_flags & RTF_EXPIRES && 188 time_after(jiffies, rt->rt6i_expires)); 189 } 190 191 /* 192 * Route lookup. Any rt6_lock is implied. 193 */ 194 195 static __inline__ struct rt6_info *rt6_device_match(struct rt6_info *rt, 196 int oif, 197 int strict) 198 { 199 struct rt6_info *local = NULL; 200 struct rt6_info *sprt; 201 202 if (oif) { 203 for (sprt = rt; sprt; sprt = sprt->u.next) { 204 struct net_device *dev = sprt->rt6i_dev; 205 if (dev->ifindex == oif) 206 return sprt; 207 if (dev->flags & IFF_LOOPBACK) { 208 if (sprt->rt6i_idev == NULL || 209 sprt->rt6i_idev->dev->ifindex != oif) { 210 if (strict && oif) 211 continue; 212 if (local && (!oif || 213 local->rt6i_idev->dev->ifindex == oif)) 214 continue; 215 } 216 local = sprt; 217 } 218 } 219 220 if (local) 221 return local; 222 223 if (strict) 224 return &ip6_null_entry; 225 } 226 return rt; 227 } 228 229 #ifdef CONFIG_IPV6_ROUTER_PREF 230 static void rt6_probe(struct rt6_info *rt) 231 { 232 struct neighbour *neigh = rt ? rt->rt6i_nexthop : NULL; 233 /* 234 * Okay, this does not seem to be appropriate 235 * for now, however, we need to check if it 236 * is really so; aka Router Reachability Probing. 237 * 238 * Router Reachability Probe MUST be rate-limited 239 * to no more than one per minute. 240 */ 241 if (!neigh || (neigh->nud_state & NUD_VALID)) 242 return; 243 read_lock_bh(&neigh->lock); 244 if (!(neigh->nud_state & NUD_VALID) && 245 time_after(jiffies, neigh->updated + rt->rt6i_idev->cnf.rtr_probe_interval)) { 246 struct in6_addr mcaddr; 247 struct in6_addr *target; 248 249 neigh->updated = jiffies; 250 read_unlock_bh(&neigh->lock); 251 252 target = (struct in6_addr *)&neigh->primary_key; 253 addrconf_addr_solict_mult(target, &mcaddr); 254 ndisc_send_ns(rt->rt6i_dev, NULL, target, &mcaddr, NULL); 255 } else 256 read_unlock_bh(&neigh->lock); 257 } 258 #else 259 static inline void rt6_probe(struct rt6_info *rt) 260 { 261 return; 262 } 263 #endif 264 265 /* 266 * Default Router Selection (RFC 2461 6.3.6) 267 */ 268 static int inline rt6_check_dev(struct rt6_info *rt, int oif) 269 { 270 struct net_device *dev = rt->rt6i_dev; 271 if (!oif || dev->ifindex == oif) 272 return 2; 273 if ((dev->flags & IFF_LOOPBACK) && 274 rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif) 275 return 1; 276 return 0; 277 } 278 279 static int inline rt6_check_neigh(struct rt6_info *rt) 280 { 281 struct neighbour *neigh = rt->rt6i_nexthop; 282 int m = 0; 283 if (rt->rt6i_flags & RTF_NONEXTHOP || 284 !(rt->rt6i_flags & RTF_GATEWAY)) 285 m = 1; 286 else if (neigh) { 287 read_lock_bh(&neigh->lock); 288 if (neigh->nud_state & NUD_VALID) 289 m = 2; 290 read_unlock_bh(&neigh->lock); 291 } 292 return m; 293 } 294 295 static int rt6_score_route(struct rt6_info *rt, int oif, 296 int strict) 297 { 298 int m, n; 299 300 m = rt6_check_dev(rt, oif); 301 if (!m && (strict & RT6_SELECT_F_IFACE)) 302 return -1; 303 #ifdef CONFIG_IPV6_ROUTER_PREF 304 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2; 305 #endif 306 n = rt6_check_neigh(rt); 307 if (n > 1) 308 m |= 16; 309 else if (!n && strict & RT6_SELECT_F_REACHABLE) 310 return -1; 311 return m; 312 } 313 314 static struct rt6_info *rt6_select(struct rt6_info **head, int oif, 315 int strict) 316 { 317 struct rt6_info *match = NULL, *last = NULL; 318 struct rt6_info *rt, *rt0 = *head; 319 u32 metric; 320 int mpri = -1; 321 322 RT6_TRACE("%s(head=%p(*head=%p), oif=%d)\n", 323 __FUNCTION__, head, head ? *head : NULL, oif); 324 325 for (rt = rt0, metric = rt0->rt6i_metric; 326 rt && rt->rt6i_metric == metric && (!last || rt != rt0); 327 rt = rt->u.next) { 328 int m; 329 330 if (rt6_check_expired(rt)) 331 continue; 332 333 last = rt; 334 335 m = rt6_score_route(rt, oif, strict); 336 if (m < 0) 337 continue; 338 339 if (m > mpri) { 340 rt6_probe(match); 341 match = rt; 342 mpri = m; 343 } else { 344 rt6_probe(rt); 345 } 346 } 347 348 if (!match && 349 (strict & RT6_SELECT_F_REACHABLE) && 350 last && last != rt0) { 351 /* no entries matched; do round-robin */ 352 static DEFINE_SPINLOCK(lock); 353 spin_lock(&lock); 354 *head = rt0->u.next; 355 rt0->u.next = last->u.next; 356 last->u.next = rt0; 357 spin_unlock(&lock); 358 } 359 360 RT6_TRACE("%s() => %p, score=%d\n", 361 __FUNCTION__, match, mpri); 362 363 return (match ? match : &ip6_null_entry); 364 } 365 366 #ifdef CONFIG_IPV6_ROUTE_INFO 367 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 368 struct in6_addr *gwaddr) 369 { 370 struct route_info *rinfo = (struct route_info *) opt; 371 struct in6_addr prefix_buf, *prefix; 372 unsigned int pref; 373 u32 lifetime; 374 struct rt6_info *rt; 375 376 if (len < sizeof(struct route_info)) { 377 return -EINVAL; 378 } 379 380 /* Sanity check for prefix_len and length */ 381 if (rinfo->length > 3) { 382 return -EINVAL; 383 } else if (rinfo->prefix_len > 128) { 384 return -EINVAL; 385 } else if (rinfo->prefix_len > 64) { 386 if (rinfo->length < 2) { 387 return -EINVAL; 388 } 389 } else if (rinfo->prefix_len > 0) { 390 if (rinfo->length < 1) { 391 return -EINVAL; 392 } 393 } 394 395 pref = rinfo->route_pref; 396 if (pref == ICMPV6_ROUTER_PREF_INVALID) 397 pref = ICMPV6_ROUTER_PREF_MEDIUM; 398 399 lifetime = htonl(rinfo->lifetime); 400 if (lifetime == 0xffffffff) { 401 /* infinity */ 402 } else if (lifetime > 0x7fffffff/HZ) { 403 /* Avoid arithmetic overflow */ 404 lifetime = 0x7fffffff/HZ - 1; 405 } 406 407 if (rinfo->length == 3) 408 prefix = (struct in6_addr *)rinfo->prefix; 409 else { 410 /* this function is safe */ 411 ipv6_addr_prefix(&prefix_buf, 412 (struct in6_addr *)rinfo->prefix, 413 rinfo->prefix_len); 414 prefix = &prefix_buf; 415 } 416 417 rt = rt6_get_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex); 418 419 if (rt && !lifetime) { 420 ip6_del_rt(rt, NULL, NULL, NULL); 421 rt = NULL; 422 } 423 424 if (!rt && lifetime) 425 rt = rt6_add_route_info(prefix, rinfo->prefix_len, gwaddr, dev->ifindex, 426 pref); 427 else if (rt) 428 rt->rt6i_flags = RTF_ROUTEINFO | 429 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 430 431 if (rt) { 432 if (lifetime == 0xffffffff) { 433 rt->rt6i_flags &= ~RTF_EXPIRES; 434 } else { 435 rt->rt6i_expires = jiffies + HZ * lifetime; 436 rt->rt6i_flags |= RTF_EXPIRES; 437 } 438 dst_release(&rt->u.dst); 439 } 440 return 0; 441 } 442 #endif 443 444 struct rt6_info *rt6_lookup(struct in6_addr *daddr, struct in6_addr *saddr, 445 int oif, int strict) 446 { 447 struct fib6_node *fn; 448 struct rt6_info *rt; 449 450 read_lock_bh(&rt6_lock); 451 fn = fib6_lookup(&ip6_routing_table, daddr, saddr); 452 rt = rt6_device_match(fn->leaf, oif, strict); 453 dst_hold(&rt->u.dst); 454 rt->u.dst.__use++; 455 read_unlock_bh(&rt6_lock); 456 457 rt->u.dst.lastuse = jiffies; 458 if (rt->u.dst.error == 0) 459 return rt; 460 dst_release(&rt->u.dst); 461 return NULL; 462 } 463 464 /* ip6_ins_rt is called with FREE rt6_lock. 465 It takes new route entry, the addition fails by any reason the 466 route is freed. In any case, if caller does not hold it, it may 467 be destroyed. 468 */ 469 470 int ip6_ins_rt(struct rt6_info *rt, struct nlmsghdr *nlh, 471 void *_rtattr, struct netlink_skb_parms *req) 472 { 473 int err; 474 475 write_lock_bh(&rt6_lock); 476 err = fib6_add(&ip6_routing_table, rt, nlh, _rtattr, req); 477 write_unlock_bh(&rt6_lock); 478 479 return err; 480 } 481 482 static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort, struct in6_addr *daddr, 483 struct in6_addr *saddr) 484 { 485 struct rt6_info *rt; 486 487 /* 488 * Clone the route. 489 */ 490 491 rt = ip6_rt_copy(ort); 492 493 if (rt) { 494 if (!(rt->rt6i_flags&RTF_GATEWAY)) { 495 if (rt->rt6i_dst.plen != 128 && 496 ipv6_addr_equal(&rt->rt6i_dst.addr, daddr)) 497 rt->rt6i_flags |= RTF_ANYCAST; 498 ipv6_addr_copy(&rt->rt6i_gateway, daddr); 499 } 500 501 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr); 502 rt->rt6i_dst.plen = 128; 503 rt->rt6i_flags |= RTF_CACHE; 504 rt->u.dst.flags |= DST_HOST; 505 506 #ifdef CONFIG_IPV6_SUBTREES 507 if (rt->rt6i_src.plen && saddr) { 508 ipv6_addr_copy(&rt->rt6i_src.addr, saddr); 509 rt->rt6i_src.plen = 128; 510 } 511 #endif 512 513 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway); 514 515 } 516 517 return rt; 518 } 519 520 static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort, struct in6_addr *daddr) 521 { 522 struct rt6_info *rt = ip6_rt_copy(ort); 523 if (rt) { 524 ipv6_addr_copy(&rt->rt6i_dst.addr, daddr); 525 rt->rt6i_dst.plen = 128; 526 rt->rt6i_flags |= RTF_CACHE; 527 if (rt->rt6i_flags & RTF_REJECT) 528 rt->u.dst.error = ort->u.dst.error; 529 rt->u.dst.flags |= DST_HOST; 530 rt->rt6i_nexthop = neigh_clone(ort->rt6i_nexthop); 531 } 532 return rt; 533 } 534 535 #define BACKTRACK() \ 536 if (rt == &ip6_null_entry) { \ 537 while ((fn = fn->parent) != NULL) { \ 538 if (fn->fn_flags & RTN_ROOT) { \ 539 goto out; \ 540 } \ 541 if (fn->fn_flags & RTN_RTINFO) \ 542 goto restart; \ 543 } \ 544 } 545 546 547 void ip6_route_input(struct sk_buff *skb) 548 { 549 struct fib6_node *fn; 550 struct rt6_info *rt, *nrt; 551 int strict; 552 int attempts = 3; 553 int err; 554 int reachable = RT6_SELECT_F_REACHABLE; 555 556 strict = ipv6_addr_type(&skb->nh.ipv6h->daddr) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL) ? RT6_SELECT_F_IFACE : 0; 557 558 relookup: 559 read_lock_bh(&rt6_lock); 560 561 restart_2: 562 fn = fib6_lookup(&ip6_routing_table, &skb->nh.ipv6h->daddr, 563 &skb->nh.ipv6h->saddr); 564 565 restart: 566 rt = rt6_select(&fn->leaf, skb->dev->ifindex, strict | reachable); 567 BACKTRACK(); 568 if (rt == &ip6_null_entry || 569 rt->rt6i_flags & RTF_CACHE) 570 goto out; 571 572 dst_hold(&rt->u.dst); 573 read_unlock_bh(&rt6_lock); 574 575 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) 576 nrt = rt6_alloc_cow(rt, &skb->nh.ipv6h->daddr, &skb->nh.ipv6h->saddr); 577 else { 578 #if CLONE_OFFLINK_ROUTE 579 nrt = rt6_alloc_clone(rt, &skb->nh.ipv6h->daddr); 580 #else 581 goto out2; 582 #endif 583 } 584 585 dst_release(&rt->u.dst); 586 rt = nrt ? : &ip6_null_entry; 587 588 dst_hold(&rt->u.dst); 589 if (nrt) { 590 err = ip6_ins_rt(nrt, NULL, NULL, &NETLINK_CB(skb)); 591 if (!err) 592 goto out2; 593 } 594 595 if (--attempts <= 0) 596 goto out2; 597 598 /* 599 * Race condition! In the gap, when rt6_lock was 600 * released someone could insert this route. Relookup. 601 */ 602 dst_release(&rt->u.dst); 603 goto relookup; 604 605 out: 606 if (reachable) { 607 reachable = 0; 608 goto restart_2; 609 } 610 dst_hold(&rt->u.dst); 611 read_unlock_bh(&rt6_lock); 612 out2: 613 rt->u.dst.lastuse = jiffies; 614 rt->u.dst.__use++; 615 skb->dst = (struct dst_entry *) rt; 616 return; 617 } 618 619 struct dst_entry * ip6_route_output(struct sock *sk, struct flowi *fl) 620 { 621 struct fib6_node *fn; 622 struct rt6_info *rt, *nrt; 623 int strict; 624 int attempts = 3; 625 int err; 626 int reachable = RT6_SELECT_F_REACHABLE; 627 628 strict = ipv6_addr_type(&fl->fl6_dst) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL) ? RT6_SELECT_F_IFACE : 0; 629 630 relookup: 631 read_lock_bh(&rt6_lock); 632 633 restart_2: 634 fn = fib6_lookup(&ip6_routing_table, &fl->fl6_dst, &fl->fl6_src); 635 636 restart: 637 rt = rt6_select(&fn->leaf, fl->oif, strict | reachable); 638 BACKTRACK(); 639 if (rt == &ip6_null_entry || 640 rt->rt6i_flags & RTF_CACHE) 641 goto out; 642 643 dst_hold(&rt->u.dst); 644 read_unlock_bh(&rt6_lock); 645 646 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) 647 nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src); 648 else { 649 #if CLONE_OFFLINK_ROUTE 650 nrt = rt6_alloc_clone(rt, &fl->fl6_dst); 651 #else 652 goto out2; 653 #endif 654 } 655 656 dst_release(&rt->u.dst); 657 rt = nrt ? : &ip6_null_entry; 658 659 dst_hold(&rt->u.dst); 660 if (nrt) { 661 err = ip6_ins_rt(nrt, NULL, NULL, NULL); 662 if (!err) 663 goto out2; 664 } 665 666 if (--attempts <= 0) 667 goto out2; 668 669 /* 670 * Race condition! In the gap, when rt6_lock was 671 * released someone could insert this route. Relookup. 672 */ 673 dst_release(&rt->u.dst); 674 goto relookup; 675 676 out: 677 if (reachable) { 678 reachable = 0; 679 goto restart_2; 680 } 681 dst_hold(&rt->u.dst); 682 read_unlock_bh(&rt6_lock); 683 out2: 684 rt->u.dst.lastuse = jiffies; 685 rt->u.dst.__use++; 686 return &rt->u.dst; 687 } 688 689 690 /* 691 * Destination cache support functions 692 */ 693 694 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) 695 { 696 struct rt6_info *rt; 697 698 rt = (struct rt6_info *) dst; 699 700 if (rt && rt->rt6i_node && (rt->rt6i_node->fn_sernum == cookie)) 701 return dst; 702 703 return NULL; 704 } 705 706 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) 707 { 708 struct rt6_info *rt = (struct rt6_info *) dst; 709 710 if (rt) { 711 if (rt->rt6i_flags & RTF_CACHE) 712 ip6_del_rt(rt, NULL, NULL, NULL); 713 else 714 dst_release(dst); 715 } 716 return NULL; 717 } 718 719 static void ip6_link_failure(struct sk_buff *skb) 720 { 721 struct rt6_info *rt; 722 723 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, skb->dev); 724 725 rt = (struct rt6_info *) skb->dst; 726 if (rt) { 727 if (rt->rt6i_flags&RTF_CACHE) { 728 dst_set_expires(&rt->u.dst, 0); 729 rt->rt6i_flags |= RTF_EXPIRES; 730 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) 731 rt->rt6i_node->fn_sernum = -1; 732 } 733 } 734 735 static void ip6_rt_update_pmtu(struct dst_entry *dst, u32 mtu) 736 { 737 struct rt6_info *rt6 = (struct rt6_info*)dst; 738 739 if (mtu < dst_mtu(dst) && rt6->rt6i_dst.plen == 128) { 740 rt6->rt6i_flags |= RTF_MODIFIED; 741 if (mtu < IPV6_MIN_MTU) { 742 mtu = IPV6_MIN_MTU; 743 dst->metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 744 } 745 dst->metrics[RTAX_MTU-1] = mtu; 746 call_netevent_notifiers(NETEVENT_PMTU_UPDATE, dst); 747 } 748 } 749 750 /* Protected by rt6_lock. */ 751 static struct dst_entry *ndisc_dst_gc_list; 752 static int ipv6_get_mtu(struct net_device *dev); 753 754 static inline unsigned int ipv6_advmss(unsigned int mtu) 755 { 756 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); 757 758 if (mtu < ip6_rt_min_advmss) 759 mtu = ip6_rt_min_advmss; 760 761 /* 762 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and 763 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. 764 * IPV6_MAXPLEN is also valid and means: "any MSS, 765 * rely only on pmtu discovery" 766 */ 767 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) 768 mtu = IPV6_MAXPLEN; 769 return mtu; 770 } 771 772 struct dst_entry *ndisc_dst_alloc(struct net_device *dev, 773 struct neighbour *neigh, 774 struct in6_addr *addr, 775 int (*output)(struct sk_buff *)) 776 { 777 struct rt6_info *rt; 778 struct inet6_dev *idev = in6_dev_get(dev); 779 780 if (unlikely(idev == NULL)) 781 return NULL; 782 783 rt = ip6_dst_alloc(); 784 if (unlikely(rt == NULL)) { 785 in6_dev_put(idev); 786 goto out; 787 } 788 789 dev_hold(dev); 790 if (neigh) 791 neigh_hold(neigh); 792 else 793 neigh = ndisc_get_neigh(dev, addr); 794 795 rt->rt6i_dev = dev; 796 rt->rt6i_idev = idev; 797 rt->rt6i_nexthop = neigh; 798 atomic_set(&rt->u.dst.__refcnt, 1); 799 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = 255; 800 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev); 801 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 802 rt->u.dst.output = output; 803 804 #if 0 /* there's no chance to use these for ndisc */ 805 rt->u.dst.flags = ipv6_addr_type(addr) & IPV6_ADDR_UNICAST 806 ? DST_HOST 807 : 0; 808 ipv6_addr_copy(&rt->rt6i_dst.addr, addr); 809 rt->rt6i_dst.plen = 128; 810 #endif 811 812 write_lock_bh(&rt6_lock); 813 rt->u.dst.next = ndisc_dst_gc_list; 814 ndisc_dst_gc_list = &rt->u.dst; 815 write_unlock_bh(&rt6_lock); 816 817 fib6_force_start_gc(); 818 819 out: 820 return (struct dst_entry *)rt; 821 } 822 823 int ndisc_dst_gc(int *more) 824 { 825 struct dst_entry *dst, *next, **pprev; 826 int freed; 827 828 next = NULL; 829 pprev = &ndisc_dst_gc_list; 830 freed = 0; 831 while ((dst = *pprev) != NULL) { 832 if (!atomic_read(&dst->__refcnt)) { 833 *pprev = dst->next; 834 dst_free(dst); 835 freed++; 836 } else { 837 pprev = &dst->next; 838 (*more)++; 839 } 840 } 841 842 return freed; 843 } 844 845 static int ip6_dst_gc(void) 846 { 847 static unsigned expire = 30*HZ; 848 static unsigned long last_gc; 849 unsigned long now = jiffies; 850 851 if (time_after(last_gc + ip6_rt_gc_min_interval, now) && 852 atomic_read(&ip6_dst_ops.entries) <= ip6_rt_max_size) 853 goto out; 854 855 expire++; 856 fib6_run_gc(expire); 857 last_gc = now; 858 if (atomic_read(&ip6_dst_ops.entries) < ip6_dst_ops.gc_thresh) 859 expire = ip6_rt_gc_timeout>>1; 860 861 out: 862 expire -= expire>>ip6_rt_gc_elasticity; 863 return (atomic_read(&ip6_dst_ops.entries) > ip6_rt_max_size); 864 } 865 866 /* Clean host part of a prefix. Not necessary in radix tree, 867 but results in cleaner routing tables. 868 869 Remove it only when all the things will work! 870 */ 871 872 static int ipv6_get_mtu(struct net_device *dev) 873 { 874 int mtu = IPV6_MIN_MTU; 875 struct inet6_dev *idev; 876 877 idev = in6_dev_get(dev); 878 if (idev) { 879 mtu = idev->cnf.mtu6; 880 in6_dev_put(idev); 881 } 882 return mtu; 883 } 884 885 int ipv6_get_hoplimit(struct net_device *dev) 886 { 887 int hoplimit = ipv6_devconf.hop_limit; 888 struct inet6_dev *idev; 889 890 idev = in6_dev_get(dev); 891 if (idev) { 892 hoplimit = idev->cnf.hop_limit; 893 in6_dev_put(idev); 894 } 895 return hoplimit; 896 } 897 898 /* 899 * 900 */ 901 902 int ip6_route_add(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, 903 void *_rtattr, struct netlink_skb_parms *req) 904 { 905 int err; 906 struct rtmsg *r; 907 struct rtattr **rta; 908 struct rt6_info *rt = NULL; 909 struct net_device *dev = NULL; 910 struct inet6_dev *idev = NULL; 911 int addr_type; 912 913 rta = (struct rtattr **) _rtattr; 914 915 if (rtmsg->rtmsg_dst_len > 128 || rtmsg->rtmsg_src_len > 128) 916 return -EINVAL; 917 #ifndef CONFIG_IPV6_SUBTREES 918 if (rtmsg->rtmsg_src_len) 919 return -EINVAL; 920 #endif 921 if (rtmsg->rtmsg_ifindex) { 922 err = -ENODEV; 923 dev = dev_get_by_index(rtmsg->rtmsg_ifindex); 924 if (!dev) 925 goto out; 926 idev = in6_dev_get(dev); 927 if (!idev) 928 goto out; 929 } 930 931 if (rtmsg->rtmsg_metric == 0) 932 rtmsg->rtmsg_metric = IP6_RT_PRIO_USER; 933 934 rt = ip6_dst_alloc(); 935 936 if (rt == NULL) { 937 err = -ENOMEM; 938 goto out; 939 } 940 941 rt->u.dst.obsolete = -1; 942 rt->rt6i_expires = jiffies + clock_t_to_jiffies(rtmsg->rtmsg_info); 943 if (nlh && (r = NLMSG_DATA(nlh))) { 944 rt->rt6i_protocol = r->rtm_protocol; 945 } else { 946 rt->rt6i_protocol = RTPROT_BOOT; 947 } 948 949 addr_type = ipv6_addr_type(&rtmsg->rtmsg_dst); 950 951 if (addr_type & IPV6_ADDR_MULTICAST) 952 rt->u.dst.input = ip6_mc_input; 953 else 954 rt->u.dst.input = ip6_forward; 955 956 rt->u.dst.output = ip6_output; 957 958 ipv6_addr_prefix(&rt->rt6i_dst.addr, 959 &rtmsg->rtmsg_dst, rtmsg->rtmsg_dst_len); 960 rt->rt6i_dst.plen = rtmsg->rtmsg_dst_len; 961 if (rt->rt6i_dst.plen == 128) 962 rt->u.dst.flags = DST_HOST; 963 964 #ifdef CONFIG_IPV6_SUBTREES 965 ipv6_addr_prefix(&rt->rt6i_src.addr, 966 &rtmsg->rtmsg_src, rtmsg->rtmsg_src_len); 967 rt->rt6i_src.plen = rtmsg->rtmsg_src_len; 968 #endif 969 970 rt->rt6i_metric = rtmsg->rtmsg_metric; 971 972 /* We cannot add true routes via loopback here, 973 they would result in kernel looping; promote them to reject routes 974 */ 975 if ((rtmsg->rtmsg_flags&RTF_REJECT) || 976 (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) { 977 /* hold loopback dev/idev if we haven't done so. */ 978 if (dev != &loopback_dev) { 979 if (dev) { 980 dev_put(dev); 981 in6_dev_put(idev); 982 } 983 dev = &loopback_dev; 984 dev_hold(dev); 985 idev = in6_dev_get(dev); 986 if (!idev) { 987 err = -ENODEV; 988 goto out; 989 } 990 } 991 rt->u.dst.output = ip6_pkt_discard_out; 992 rt->u.dst.input = ip6_pkt_discard; 993 rt->u.dst.error = -ENETUNREACH; 994 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP; 995 goto install_route; 996 } 997 998 if (rtmsg->rtmsg_flags & RTF_GATEWAY) { 999 struct in6_addr *gw_addr; 1000 int gwa_type; 1001 1002 gw_addr = &rtmsg->rtmsg_gateway; 1003 ipv6_addr_copy(&rt->rt6i_gateway, &rtmsg->rtmsg_gateway); 1004 gwa_type = ipv6_addr_type(gw_addr); 1005 1006 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) { 1007 struct rt6_info *grt; 1008 1009 /* IPv6 strictly inhibits using not link-local 1010 addresses as nexthop address. 1011 Otherwise, router will not able to send redirects. 1012 It is very good, but in some (rare!) circumstances 1013 (SIT, PtP, NBMA NOARP links) it is handy to allow 1014 some exceptions. --ANK 1015 */ 1016 err = -EINVAL; 1017 if (!(gwa_type&IPV6_ADDR_UNICAST)) 1018 goto out; 1019 1020 grt = rt6_lookup(gw_addr, NULL, rtmsg->rtmsg_ifindex, 1); 1021 1022 err = -EHOSTUNREACH; 1023 if (grt == NULL) 1024 goto out; 1025 if (dev) { 1026 if (dev != grt->rt6i_dev) { 1027 dst_release(&grt->u.dst); 1028 goto out; 1029 } 1030 } else { 1031 dev = grt->rt6i_dev; 1032 idev = grt->rt6i_idev; 1033 dev_hold(dev); 1034 in6_dev_hold(grt->rt6i_idev); 1035 } 1036 if (!(grt->rt6i_flags&RTF_GATEWAY)) 1037 err = 0; 1038 dst_release(&grt->u.dst); 1039 1040 if (err) 1041 goto out; 1042 } 1043 err = -EINVAL; 1044 if (dev == NULL || (dev->flags&IFF_LOOPBACK)) 1045 goto out; 1046 } 1047 1048 err = -ENODEV; 1049 if (dev == NULL) 1050 goto out; 1051 1052 if (rtmsg->rtmsg_flags & (RTF_GATEWAY|RTF_NONEXTHOP)) { 1053 rt->rt6i_nexthop = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev); 1054 if (IS_ERR(rt->rt6i_nexthop)) { 1055 err = PTR_ERR(rt->rt6i_nexthop); 1056 rt->rt6i_nexthop = NULL; 1057 goto out; 1058 } 1059 } 1060 1061 rt->rt6i_flags = rtmsg->rtmsg_flags; 1062 1063 install_route: 1064 if (rta && rta[RTA_METRICS-1]) { 1065 int attrlen = RTA_PAYLOAD(rta[RTA_METRICS-1]); 1066 struct rtattr *attr = RTA_DATA(rta[RTA_METRICS-1]); 1067 1068 while (RTA_OK(attr, attrlen)) { 1069 unsigned flavor = attr->rta_type; 1070 if (flavor) { 1071 if (flavor > RTAX_MAX) { 1072 err = -EINVAL; 1073 goto out; 1074 } 1075 rt->u.dst.metrics[flavor-1] = 1076 *(u32 *)RTA_DATA(attr); 1077 } 1078 attr = RTA_NEXT(attr, attrlen); 1079 } 1080 } 1081 1082 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0) 1083 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1; 1084 if (!rt->u.dst.metrics[RTAX_MTU-1]) 1085 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev); 1086 if (!rt->u.dst.metrics[RTAX_ADVMSS-1]) 1087 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 1088 rt->u.dst.dev = dev; 1089 rt->rt6i_idev = idev; 1090 return ip6_ins_rt(rt, nlh, _rtattr, req); 1091 1092 out: 1093 if (dev) 1094 dev_put(dev); 1095 if (idev) 1096 in6_dev_put(idev); 1097 if (rt) 1098 dst_free((struct dst_entry *) rt); 1099 return err; 1100 } 1101 1102 int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) 1103 { 1104 int err; 1105 1106 write_lock_bh(&rt6_lock); 1107 1108 err = fib6_del(rt, nlh, _rtattr, req); 1109 dst_release(&rt->u.dst); 1110 1111 write_unlock_bh(&rt6_lock); 1112 1113 return err; 1114 } 1115 1116 static int ip6_route_del(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) 1117 { 1118 struct fib6_node *fn; 1119 struct rt6_info *rt; 1120 int err = -ESRCH; 1121 1122 read_lock_bh(&rt6_lock); 1123 1124 fn = fib6_locate(&ip6_routing_table, 1125 &rtmsg->rtmsg_dst, rtmsg->rtmsg_dst_len, 1126 &rtmsg->rtmsg_src, rtmsg->rtmsg_src_len); 1127 1128 if (fn) { 1129 for (rt = fn->leaf; rt; rt = rt->u.next) { 1130 if (rtmsg->rtmsg_ifindex && 1131 (rt->rt6i_dev == NULL || 1132 rt->rt6i_dev->ifindex != rtmsg->rtmsg_ifindex)) 1133 continue; 1134 if (rtmsg->rtmsg_flags&RTF_GATEWAY && 1135 !ipv6_addr_equal(&rtmsg->rtmsg_gateway, &rt->rt6i_gateway)) 1136 continue; 1137 if (rtmsg->rtmsg_metric && 1138 rtmsg->rtmsg_metric != rt->rt6i_metric) 1139 continue; 1140 dst_hold(&rt->u.dst); 1141 read_unlock_bh(&rt6_lock); 1142 1143 return ip6_del_rt(rt, nlh, _rtattr, req); 1144 } 1145 } 1146 read_unlock_bh(&rt6_lock); 1147 1148 return err; 1149 } 1150 1151 /* 1152 * Handle redirects 1153 */ 1154 void rt6_redirect(struct in6_addr *dest, struct in6_addr *saddr, 1155 struct neighbour *neigh, u8 *lladdr, int on_link) 1156 { 1157 struct rt6_info *rt, *nrt = NULL; 1158 int strict; 1159 struct fib6_node *fn; 1160 struct netevent_redirect netevent; 1161 1162 /* 1163 * Get the "current" route for this destination and 1164 * check if the redirect has come from approriate router. 1165 * 1166 * RFC 2461 specifies that redirects should only be 1167 * accepted if they come from the nexthop to the target. 1168 * Due to the way the routes are chosen, this notion 1169 * is a bit fuzzy and one might need to check all possible 1170 * routes. 1171 */ 1172 strict = ipv6_addr_type(dest) & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL); 1173 1174 read_lock_bh(&rt6_lock); 1175 fn = fib6_lookup(&ip6_routing_table, dest, NULL); 1176 restart: 1177 for (rt = fn->leaf; rt; rt = rt->u.next) { 1178 /* 1179 * Current route is on-link; redirect is always invalid. 1180 * 1181 * Seems, previous statement is not true. It could 1182 * be node, which looks for us as on-link (f.e. proxy ndisc) 1183 * But then router serving it might decide, that we should 1184 * know truth 8)8) --ANK (980726). 1185 */ 1186 if (rt6_check_expired(rt)) 1187 continue; 1188 if (!(rt->rt6i_flags & RTF_GATEWAY)) 1189 continue; 1190 if (neigh->dev != rt->rt6i_dev) 1191 continue; 1192 if (!ipv6_addr_equal(saddr, &rt->rt6i_gateway)) 1193 continue; 1194 break; 1195 } 1196 if (rt) 1197 dst_hold(&rt->u.dst); 1198 else if (strict) { 1199 while ((fn = fn->parent) != NULL) { 1200 if (fn->fn_flags & RTN_ROOT) 1201 break; 1202 if (fn->fn_flags & RTN_RTINFO) 1203 goto restart; 1204 } 1205 } 1206 read_unlock_bh(&rt6_lock); 1207 1208 if (!rt) { 1209 if (net_ratelimit()) 1210 printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop " 1211 "for redirect target\n"); 1212 return; 1213 } 1214 1215 /* 1216 * We have finally decided to accept it. 1217 */ 1218 1219 neigh_update(neigh, lladdr, NUD_STALE, 1220 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1221 NEIGH_UPDATE_F_OVERRIDE| 1222 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1223 NEIGH_UPDATE_F_ISROUTER)) 1224 ); 1225 1226 /* 1227 * Redirect received -> path was valid. 1228 * Look, redirects are sent only in response to data packets, 1229 * so that this nexthop apparently is reachable. --ANK 1230 */ 1231 dst_confirm(&rt->u.dst); 1232 1233 /* Duplicate redirect: silently ignore. */ 1234 if (neigh == rt->u.dst.neighbour) 1235 goto out; 1236 1237 nrt = ip6_rt_copy(rt); 1238 if (nrt == NULL) 1239 goto out; 1240 1241 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; 1242 if (on_link) 1243 nrt->rt6i_flags &= ~RTF_GATEWAY; 1244 1245 ipv6_addr_copy(&nrt->rt6i_dst.addr, dest); 1246 nrt->rt6i_dst.plen = 128; 1247 nrt->u.dst.flags |= DST_HOST; 1248 1249 ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key); 1250 nrt->rt6i_nexthop = neigh_clone(neigh); 1251 /* Reset pmtu, it may be better */ 1252 nrt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev); 1253 nrt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&nrt->u.dst)); 1254 1255 if (ip6_ins_rt(nrt, NULL, NULL, NULL)) 1256 goto out; 1257 1258 netevent.old = &rt->u.dst; 1259 netevent.new = &nrt->u.dst; 1260 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent); 1261 1262 if (rt->rt6i_flags&RTF_CACHE) { 1263 ip6_del_rt(rt, NULL, NULL, NULL); 1264 return; 1265 } 1266 1267 out: 1268 dst_release(&rt->u.dst); 1269 return; 1270 } 1271 1272 /* 1273 * Handle ICMP "packet too big" messages 1274 * i.e. Path MTU discovery 1275 */ 1276 1277 void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr, 1278 struct net_device *dev, u32 pmtu) 1279 { 1280 struct rt6_info *rt, *nrt; 1281 int allfrag = 0; 1282 1283 rt = rt6_lookup(daddr, saddr, dev->ifindex, 0); 1284 if (rt == NULL) 1285 return; 1286 1287 if (pmtu >= dst_mtu(&rt->u.dst)) 1288 goto out; 1289 1290 if (pmtu < IPV6_MIN_MTU) { 1291 /* 1292 * According to RFC2460, PMTU is set to the IPv6 Minimum Link 1293 * MTU (1280) and a fragment header should always be included 1294 * after a node receiving Too Big message reporting PMTU is 1295 * less than the IPv6 Minimum Link MTU. 1296 */ 1297 pmtu = IPV6_MIN_MTU; 1298 allfrag = 1; 1299 } 1300 1301 /* New mtu received -> path was valid. 1302 They are sent only in response to data packets, 1303 so that this nexthop apparently is reachable. --ANK 1304 */ 1305 dst_confirm(&rt->u.dst); 1306 1307 /* Host route. If it is static, it would be better 1308 not to override it, but add new one, so that 1309 when cache entry will expire old pmtu 1310 would return automatically. 1311 */ 1312 if (rt->rt6i_flags & RTF_CACHE) { 1313 rt->u.dst.metrics[RTAX_MTU-1] = pmtu; 1314 if (allfrag) 1315 rt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 1316 dst_set_expires(&rt->u.dst, ip6_rt_mtu_expires); 1317 rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES; 1318 goto out; 1319 } 1320 1321 /* Network route. 1322 Two cases are possible: 1323 1. It is connected route. Action: COW 1324 2. It is gatewayed route or NONEXTHOP route. Action: clone it. 1325 */ 1326 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) 1327 nrt = rt6_alloc_cow(rt, daddr, saddr); 1328 else 1329 nrt = rt6_alloc_clone(rt, daddr); 1330 1331 if (nrt) { 1332 nrt->u.dst.metrics[RTAX_MTU-1] = pmtu; 1333 if (allfrag) 1334 nrt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 1335 1336 /* According to RFC 1981, detecting PMTU increase shouldn't be 1337 * happened within 5 mins, the recommended timer is 10 mins. 1338 * Here this route expiration time is set to ip6_rt_mtu_expires 1339 * which is 10 mins. After 10 mins the decreased pmtu is expired 1340 * and detecting PMTU increase will be automatically happened. 1341 */ 1342 dst_set_expires(&nrt->u.dst, ip6_rt_mtu_expires); 1343 nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES; 1344 1345 ip6_ins_rt(nrt, NULL, NULL, NULL); 1346 } 1347 out: 1348 dst_release(&rt->u.dst); 1349 } 1350 1351 /* 1352 * Misc support functions 1353 */ 1354 1355 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort) 1356 { 1357 struct rt6_info *rt = ip6_dst_alloc(); 1358 1359 if (rt) { 1360 rt->u.dst.input = ort->u.dst.input; 1361 rt->u.dst.output = ort->u.dst.output; 1362 1363 memcpy(rt->u.dst.metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32)); 1364 rt->u.dst.dev = ort->u.dst.dev; 1365 if (rt->u.dst.dev) 1366 dev_hold(rt->u.dst.dev); 1367 rt->rt6i_idev = ort->rt6i_idev; 1368 if (rt->rt6i_idev) 1369 in6_dev_hold(rt->rt6i_idev); 1370 rt->u.dst.lastuse = jiffies; 1371 rt->rt6i_expires = 0; 1372 1373 ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway); 1374 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; 1375 rt->rt6i_metric = 0; 1376 1377 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); 1378 #ifdef CONFIG_IPV6_SUBTREES 1379 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 1380 #endif 1381 } 1382 return rt; 1383 } 1384 1385 #ifdef CONFIG_IPV6_ROUTE_INFO 1386 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen, 1387 struct in6_addr *gwaddr, int ifindex) 1388 { 1389 struct fib6_node *fn; 1390 struct rt6_info *rt = NULL; 1391 1392 write_lock_bh(&rt6_lock); 1393 fn = fib6_locate(&ip6_routing_table, prefix ,prefixlen, NULL, 0); 1394 if (!fn) 1395 goto out; 1396 1397 for (rt = fn->leaf; rt; rt = rt->u.next) { 1398 if (rt->rt6i_dev->ifindex != ifindex) 1399 continue; 1400 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY)) 1401 continue; 1402 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr)) 1403 continue; 1404 dst_hold(&rt->u.dst); 1405 break; 1406 } 1407 out: 1408 write_unlock_bh(&rt6_lock); 1409 return rt; 1410 } 1411 1412 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen, 1413 struct in6_addr *gwaddr, int ifindex, 1414 unsigned pref) 1415 { 1416 struct in6_rtmsg rtmsg; 1417 1418 memset(&rtmsg, 0, sizeof(rtmsg)); 1419 rtmsg.rtmsg_type = RTMSG_NEWROUTE; 1420 ipv6_addr_copy(&rtmsg.rtmsg_dst, prefix); 1421 rtmsg.rtmsg_dst_len = prefixlen; 1422 ipv6_addr_copy(&rtmsg.rtmsg_gateway, gwaddr); 1423 rtmsg.rtmsg_metric = 1024; 1424 rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | RTF_UP | RTF_PREF(pref); 1425 /* We should treat it as a default route if prefix length is 0. */ 1426 if (!prefixlen) 1427 rtmsg.rtmsg_flags |= RTF_DEFAULT; 1428 rtmsg.rtmsg_ifindex = ifindex; 1429 1430 ip6_route_add(&rtmsg, NULL, NULL, NULL); 1431 1432 return rt6_get_route_info(prefix, prefixlen, gwaddr, ifindex); 1433 } 1434 #endif 1435 1436 struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *dev) 1437 { 1438 struct rt6_info *rt; 1439 struct fib6_node *fn; 1440 1441 fn = &ip6_routing_table; 1442 1443 write_lock_bh(&rt6_lock); 1444 for (rt = fn->leaf; rt; rt=rt->u.next) { 1445 if (dev == rt->rt6i_dev && 1446 ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && 1447 ipv6_addr_equal(&rt->rt6i_gateway, addr)) 1448 break; 1449 } 1450 if (rt) 1451 dst_hold(&rt->u.dst); 1452 write_unlock_bh(&rt6_lock); 1453 return rt; 1454 } 1455 1456 struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr, 1457 struct net_device *dev, 1458 unsigned int pref) 1459 { 1460 struct in6_rtmsg rtmsg; 1461 1462 memset(&rtmsg, 0, sizeof(struct in6_rtmsg)); 1463 rtmsg.rtmsg_type = RTMSG_NEWROUTE; 1464 ipv6_addr_copy(&rtmsg.rtmsg_gateway, gwaddr); 1465 rtmsg.rtmsg_metric = 1024; 1466 rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | RTF_UP | RTF_EXPIRES | 1467 RTF_PREF(pref); 1468 1469 rtmsg.rtmsg_ifindex = dev->ifindex; 1470 1471 ip6_route_add(&rtmsg, NULL, NULL, NULL); 1472 return rt6_get_dflt_router(gwaddr, dev); 1473 } 1474 1475 void rt6_purge_dflt_routers(void) 1476 { 1477 struct rt6_info *rt; 1478 1479 restart: 1480 read_lock_bh(&rt6_lock); 1481 for (rt = ip6_routing_table.leaf; rt; rt = rt->u.next) { 1482 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) { 1483 dst_hold(&rt->u.dst); 1484 1485 read_unlock_bh(&rt6_lock); 1486 1487 ip6_del_rt(rt, NULL, NULL, NULL); 1488 1489 goto restart; 1490 } 1491 } 1492 read_unlock_bh(&rt6_lock); 1493 } 1494 1495 int ipv6_route_ioctl(unsigned int cmd, void __user *arg) 1496 { 1497 struct in6_rtmsg rtmsg; 1498 int err; 1499 1500 switch(cmd) { 1501 case SIOCADDRT: /* Add a route */ 1502 case SIOCDELRT: /* Delete a route */ 1503 if (!capable(CAP_NET_ADMIN)) 1504 return -EPERM; 1505 err = copy_from_user(&rtmsg, arg, 1506 sizeof(struct in6_rtmsg)); 1507 if (err) 1508 return -EFAULT; 1509 1510 rtnl_lock(); 1511 switch (cmd) { 1512 case SIOCADDRT: 1513 err = ip6_route_add(&rtmsg, NULL, NULL, NULL); 1514 break; 1515 case SIOCDELRT: 1516 err = ip6_route_del(&rtmsg, NULL, NULL, NULL); 1517 break; 1518 default: 1519 err = -EINVAL; 1520 } 1521 rtnl_unlock(); 1522 1523 return err; 1524 }; 1525 1526 return -EINVAL; 1527 } 1528 1529 /* 1530 * Drop the packet on the floor 1531 */ 1532 1533 static int ip6_pkt_discard(struct sk_buff *skb) 1534 { 1535 int type = ipv6_addr_type(&skb->nh.ipv6h->daddr); 1536 if (type == IPV6_ADDR_ANY || type == IPV6_ADDR_RESERVED) 1537 IP6_INC_STATS(IPSTATS_MIB_INADDRERRORS); 1538 1539 IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES); 1540 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, skb->dev); 1541 kfree_skb(skb); 1542 return 0; 1543 } 1544 1545 static int ip6_pkt_discard_out(struct sk_buff *skb) 1546 { 1547 skb->dev = skb->dst->dev; 1548 return ip6_pkt_discard(skb); 1549 } 1550 1551 /* 1552 * Allocate a dst for local (unicast / anycast) address. 1553 */ 1554 1555 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev, 1556 const struct in6_addr *addr, 1557 int anycast) 1558 { 1559 struct rt6_info *rt = ip6_dst_alloc(); 1560 1561 if (rt == NULL) 1562 return ERR_PTR(-ENOMEM); 1563 1564 dev_hold(&loopback_dev); 1565 in6_dev_hold(idev); 1566 1567 rt->u.dst.flags = DST_HOST; 1568 rt->u.dst.input = ip6_input; 1569 rt->u.dst.output = ip6_output; 1570 rt->rt6i_dev = &loopback_dev; 1571 rt->rt6i_idev = idev; 1572 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev); 1573 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 1574 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1; 1575 rt->u.dst.obsolete = -1; 1576 1577 rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP; 1578 if (anycast) 1579 rt->rt6i_flags |= RTF_ANYCAST; 1580 else 1581 rt->rt6i_flags |= RTF_LOCAL; 1582 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway); 1583 if (rt->rt6i_nexthop == NULL) { 1584 dst_free((struct dst_entry *) rt); 1585 return ERR_PTR(-ENOMEM); 1586 } 1587 1588 ipv6_addr_copy(&rt->rt6i_dst.addr, addr); 1589 rt->rt6i_dst.plen = 128; 1590 1591 atomic_set(&rt->u.dst.__refcnt, 1); 1592 1593 return rt; 1594 } 1595 1596 static int fib6_ifdown(struct rt6_info *rt, void *arg) 1597 { 1598 if (((void*)rt->rt6i_dev == arg || arg == NULL) && 1599 rt != &ip6_null_entry) { 1600 RT6_TRACE("deleted by ifdown %p\n", rt); 1601 return -1; 1602 } 1603 return 0; 1604 } 1605 1606 void rt6_ifdown(struct net_device *dev) 1607 { 1608 write_lock_bh(&rt6_lock); 1609 fib6_clean_tree(&ip6_routing_table, fib6_ifdown, 0, dev); 1610 write_unlock_bh(&rt6_lock); 1611 } 1612 1613 struct rt6_mtu_change_arg 1614 { 1615 struct net_device *dev; 1616 unsigned mtu; 1617 }; 1618 1619 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg) 1620 { 1621 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; 1622 struct inet6_dev *idev; 1623 1624 /* In IPv6 pmtu discovery is not optional, 1625 so that RTAX_MTU lock cannot disable it. 1626 We still use this lock to block changes 1627 caused by addrconf/ndisc. 1628 */ 1629 1630 idev = __in6_dev_get(arg->dev); 1631 if (idev == NULL) 1632 return 0; 1633 1634 /* For administrative MTU increase, there is no way to discover 1635 IPv6 PMTU increase, so PMTU increase should be updated here. 1636 Since RFC 1981 doesn't include administrative MTU increase 1637 update PMTU increase is a MUST. (i.e. jumbo frame) 1638 */ 1639 /* 1640 If new MTU is less than route PMTU, this new MTU will be the 1641 lowest MTU in the path, update the route PMTU to reflect PMTU 1642 decreases; if new MTU is greater than route PMTU, and the 1643 old MTU is the lowest MTU in the path, update the route PMTU 1644 to reflect the increase. In this case if the other nodes' MTU 1645 also have the lowest MTU, TOO BIG MESSAGE will be lead to 1646 PMTU discouvery. 1647 */ 1648 if (rt->rt6i_dev == arg->dev && 1649 !dst_metric_locked(&rt->u.dst, RTAX_MTU) && 1650 (dst_mtu(&rt->u.dst) > arg->mtu || 1651 (dst_mtu(&rt->u.dst) < arg->mtu && 1652 dst_mtu(&rt->u.dst) == idev->cnf.mtu6))) 1653 rt->u.dst.metrics[RTAX_MTU-1] = arg->mtu; 1654 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu); 1655 return 0; 1656 } 1657 1658 void rt6_mtu_change(struct net_device *dev, unsigned mtu) 1659 { 1660 struct rt6_mtu_change_arg arg; 1661 1662 arg.dev = dev; 1663 arg.mtu = mtu; 1664 read_lock_bh(&rt6_lock); 1665 fib6_clean_tree(&ip6_routing_table, rt6_mtu_change_route, 0, &arg); 1666 read_unlock_bh(&rt6_lock); 1667 } 1668 1669 static int inet6_rtm_to_rtmsg(struct rtmsg *r, struct rtattr **rta, 1670 struct in6_rtmsg *rtmsg) 1671 { 1672 memset(rtmsg, 0, sizeof(*rtmsg)); 1673 1674 rtmsg->rtmsg_dst_len = r->rtm_dst_len; 1675 rtmsg->rtmsg_src_len = r->rtm_src_len; 1676 rtmsg->rtmsg_flags = RTF_UP; 1677 if (r->rtm_type == RTN_UNREACHABLE) 1678 rtmsg->rtmsg_flags |= RTF_REJECT; 1679 1680 if (rta[RTA_GATEWAY-1]) { 1681 if (rta[RTA_GATEWAY-1]->rta_len != RTA_LENGTH(16)) 1682 return -EINVAL; 1683 memcpy(&rtmsg->rtmsg_gateway, RTA_DATA(rta[RTA_GATEWAY-1]), 16); 1684 rtmsg->rtmsg_flags |= RTF_GATEWAY; 1685 } 1686 if (rta[RTA_DST-1]) { 1687 if (RTA_PAYLOAD(rta[RTA_DST-1]) < ((r->rtm_dst_len+7)>>3)) 1688 return -EINVAL; 1689 memcpy(&rtmsg->rtmsg_dst, RTA_DATA(rta[RTA_DST-1]), ((r->rtm_dst_len+7)>>3)); 1690 } 1691 if (rta[RTA_SRC-1]) { 1692 if (RTA_PAYLOAD(rta[RTA_SRC-1]) < ((r->rtm_src_len+7)>>3)) 1693 return -EINVAL; 1694 memcpy(&rtmsg->rtmsg_src, RTA_DATA(rta[RTA_SRC-1]), ((r->rtm_src_len+7)>>3)); 1695 } 1696 if (rta[RTA_OIF-1]) { 1697 if (rta[RTA_OIF-1]->rta_len != RTA_LENGTH(sizeof(int))) 1698 return -EINVAL; 1699 memcpy(&rtmsg->rtmsg_ifindex, RTA_DATA(rta[RTA_OIF-1]), sizeof(int)); 1700 } 1701 if (rta[RTA_PRIORITY-1]) { 1702 if (rta[RTA_PRIORITY-1]->rta_len != RTA_LENGTH(4)) 1703 return -EINVAL; 1704 memcpy(&rtmsg->rtmsg_metric, RTA_DATA(rta[RTA_PRIORITY-1]), 4); 1705 } 1706 return 0; 1707 } 1708 1709 int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 1710 { 1711 struct rtmsg *r = NLMSG_DATA(nlh); 1712 struct in6_rtmsg rtmsg; 1713 1714 if (inet6_rtm_to_rtmsg(r, arg, &rtmsg)) 1715 return -EINVAL; 1716 return ip6_route_del(&rtmsg, nlh, arg, &NETLINK_CB(skb)); 1717 } 1718 1719 int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 1720 { 1721 struct rtmsg *r = NLMSG_DATA(nlh); 1722 struct in6_rtmsg rtmsg; 1723 1724 if (inet6_rtm_to_rtmsg(r, arg, &rtmsg)) 1725 return -EINVAL; 1726 return ip6_route_add(&rtmsg, nlh, arg, &NETLINK_CB(skb)); 1727 } 1728 1729 struct rt6_rtnl_dump_arg 1730 { 1731 struct sk_buff *skb; 1732 struct netlink_callback *cb; 1733 }; 1734 1735 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt, 1736 struct in6_addr *dst, struct in6_addr *src, 1737 int iif, int type, u32 pid, u32 seq, 1738 int prefix, unsigned int flags) 1739 { 1740 struct rtmsg *rtm; 1741 struct nlmsghdr *nlh; 1742 unsigned char *b = skb->tail; 1743 struct rta_cacheinfo ci; 1744 1745 if (prefix) { /* user wants prefix routes only */ 1746 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) { 1747 /* success since this is not a prefix route */ 1748 return 1; 1749 } 1750 } 1751 1752 nlh = NLMSG_NEW(skb, pid, seq, type, sizeof(*rtm), flags); 1753 rtm = NLMSG_DATA(nlh); 1754 rtm->rtm_family = AF_INET6; 1755 rtm->rtm_dst_len = rt->rt6i_dst.plen; 1756 rtm->rtm_src_len = rt->rt6i_src.plen; 1757 rtm->rtm_tos = 0; 1758 rtm->rtm_table = RT_TABLE_MAIN; 1759 if (rt->rt6i_flags&RTF_REJECT) 1760 rtm->rtm_type = RTN_UNREACHABLE; 1761 else if (rt->rt6i_dev && (rt->rt6i_dev->flags&IFF_LOOPBACK)) 1762 rtm->rtm_type = RTN_LOCAL; 1763 else 1764 rtm->rtm_type = RTN_UNICAST; 1765 rtm->rtm_flags = 0; 1766 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 1767 rtm->rtm_protocol = rt->rt6i_protocol; 1768 if (rt->rt6i_flags&RTF_DYNAMIC) 1769 rtm->rtm_protocol = RTPROT_REDIRECT; 1770 else if (rt->rt6i_flags & RTF_ADDRCONF) 1771 rtm->rtm_protocol = RTPROT_KERNEL; 1772 else if (rt->rt6i_flags&RTF_DEFAULT) 1773 rtm->rtm_protocol = RTPROT_RA; 1774 1775 if (rt->rt6i_flags&RTF_CACHE) 1776 rtm->rtm_flags |= RTM_F_CLONED; 1777 1778 if (dst) { 1779 RTA_PUT(skb, RTA_DST, 16, dst); 1780 rtm->rtm_dst_len = 128; 1781 } else if (rtm->rtm_dst_len) 1782 RTA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr); 1783 #ifdef CONFIG_IPV6_SUBTREES 1784 if (src) { 1785 RTA_PUT(skb, RTA_SRC, 16, src); 1786 rtm->rtm_src_len = 128; 1787 } else if (rtm->rtm_src_len) 1788 RTA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr); 1789 #endif 1790 if (iif) 1791 RTA_PUT(skb, RTA_IIF, 4, &iif); 1792 else if (dst) { 1793 struct in6_addr saddr_buf; 1794 if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0) 1795 RTA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); 1796 } 1797 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0) 1798 goto rtattr_failure; 1799 if (rt->u.dst.neighbour) 1800 RTA_PUT(skb, RTA_GATEWAY, 16, &rt->u.dst.neighbour->primary_key); 1801 if (rt->u.dst.dev) 1802 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->rt6i_dev->ifindex); 1803 RTA_PUT(skb, RTA_PRIORITY, 4, &rt->rt6i_metric); 1804 ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse); 1805 if (rt->rt6i_expires) 1806 ci.rta_expires = jiffies_to_clock_t(rt->rt6i_expires - jiffies); 1807 else 1808 ci.rta_expires = 0; 1809 ci.rta_used = rt->u.dst.__use; 1810 ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt); 1811 ci.rta_error = rt->u.dst.error; 1812 ci.rta_id = 0; 1813 ci.rta_ts = 0; 1814 ci.rta_tsage = 0; 1815 RTA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci); 1816 nlh->nlmsg_len = skb->tail - b; 1817 return skb->len; 1818 1819 nlmsg_failure: 1820 rtattr_failure: 1821 skb_trim(skb, b - skb->data); 1822 return -1; 1823 } 1824 1825 static int rt6_dump_route(struct rt6_info *rt, void *p_arg) 1826 { 1827 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; 1828 int prefix; 1829 1830 if (arg->cb->nlh->nlmsg_len >= NLMSG_LENGTH(sizeof(struct rtmsg))) { 1831 struct rtmsg *rtm = NLMSG_DATA(arg->cb->nlh); 1832 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0; 1833 } else 1834 prefix = 0; 1835 1836 return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE, 1837 NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq, 1838 prefix, NLM_F_MULTI); 1839 } 1840 1841 static int fib6_dump_node(struct fib6_walker_t *w) 1842 { 1843 int res; 1844 struct rt6_info *rt; 1845 1846 for (rt = w->leaf; rt; rt = rt->u.next) { 1847 res = rt6_dump_route(rt, w->args); 1848 if (res < 0) { 1849 /* Frame is full, suspend walking */ 1850 w->leaf = rt; 1851 return 1; 1852 } 1853 BUG_TRAP(res!=0); 1854 } 1855 w->leaf = NULL; 1856 return 0; 1857 } 1858 1859 static void fib6_dump_end(struct netlink_callback *cb) 1860 { 1861 struct fib6_walker_t *w = (void*)cb->args[0]; 1862 1863 if (w) { 1864 cb->args[0] = 0; 1865 fib6_walker_unlink(w); 1866 kfree(w); 1867 } 1868 cb->done = (void*)cb->args[1]; 1869 cb->args[1] = 0; 1870 } 1871 1872 static int fib6_dump_done(struct netlink_callback *cb) 1873 { 1874 fib6_dump_end(cb); 1875 return cb->done ? cb->done(cb) : 0; 1876 } 1877 1878 int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 1879 { 1880 struct rt6_rtnl_dump_arg arg; 1881 struct fib6_walker_t *w; 1882 int res; 1883 1884 arg.skb = skb; 1885 arg.cb = cb; 1886 1887 w = (void*)cb->args[0]; 1888 if (w == NULL) { 1889 /* New dump: 1890 * 1891 * 1. hook callback destructor. 1892 */ 1893 cb->args[1] = (long)cb->done; 1894 cb->done = fib6_dump_done; 1895 1896 /* 1897 * 2. allocate and initialize walker. 1898 */ 1899 w = kzalloc(sizeof(*w), GFP_ATOMIC); 1900 if (w == NULL) 1901 return -ENOMEM; 1902 RT6_TRACE("dump<%p", w); 1903 w->root = &ip6_routing_table; 1904 w->func = fib6_dump_node; 1905 w->args = &arg; 1906 cb->args[0] = (long)w; 1907 read_lock_bh(&rt6_lock); 1908 res = fib6_walk(w); 1909 read_unlock_bh(&rt6_lock); 1910 } else { 1911 w->args = &arg; 1912 read_lock_bh(&rt6_lock); 1913 res = fib6_walk_continue(w); 1914 read_unlock_bh(&rt6_lock); 1915 } 1916 #if RT6_DEBUG >= 3 1917 if (res <= 0 && skb->len == 0) 1918 RT6_TRACE("%p>dump end\n", w); 1919 #endif 1920 res = res < 0 ? res : skb->len; 1921 /* res < 0 is an error. (really, impossible) 1922 res == 0 means that dump is complete, but skb still can contain data. 1923 res > 0 dump is not complete, but frame is full. 1924 */ 1925 /* Destroy walker, if dump of this table is complete. */ 1926 if (res <= 0) 1927 fib6_dump_end(cb); 1928 return res; 1929 } 1930 1931 int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 1932 { 1933 struct rtattr **rta = arg; 1934 int iif = 0; 1935 int err = -ENOBUFS; 1936 struct sk_buff *skb; 1937 struct flowi fl; 1938 struct rt6_info *rt; 1939 1940 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1941 if (skb == NULL) 1942 goto out; 1943 1944 /* Reserve room for dummy headers, this skb can pass 1945 through good chunk of routing engine. 1946 */ 1947 skb->mac.raw = skb->data; 1948 skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr)); 1949 1950 memset(&fl, 0, sizeof(fl)); 1951 if (rta[RTA_SRC-1]) 1952 ipv6_addr_copy(&fl.fl6_src, 1953 (struct in6_addr*)RTA_DATA(rta[RTA_SRC-1])); 1954 if (rta[RTA_DST-1]) 1955 ipv6_addr_copy(&fl.fl6_dst, 1956 (struct in6_addr*)RTA_DATA(rta[RTA_DST-1])); 1957 1958 if (rta[RTA_IIF-1]) 1959 memcpy(&iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int)); 1960 1961 if (iif) { 1962 struct net_device *dev; 1963 dev = __dev_get_by_index(iif); 1964 if (!dev) { 1965 err = -ENODEV; 1966 goto out_free; 1967 } 1968 } 1969 1970 fl.oif = 0; 1971 if (rta[RTA_OIF-1]) 1972 memcpy(&fl.oif, RTA_DATA(rta[RTA_OIF-1]), sizeof(int)); 1973 1974 rt = (struct rt6_info*)ip6_route_output(NULL, &fl); 1975 1976 skb->dst = &rt->u.dst; 1977 1978 NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid; 1979 err = rt6_fill_node(skb, rt, 1980 &fl.fl6_dst, &fl.fl6_src, 1981 iif, 1982 RTM_NEWROUTE, NETLINK_CB(in_skb).pid, 1983 nlh->nlmsg_seq, 0, 0); 1984 if (err < 0) { 1985 err = -EMSGSIZE; 1986 goto out_free; 1987 } 1988 1989 err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); 1990 if (err > 0) 1991 err = 0; 1992 out: 1993 return err; 1994 out_free: 1995 kfree_skb(skb); 1996 goto out; 1997 } 1998 1999 void inet6_rt_notify(int event, struct rt6_info *rt, struct nlmsghdr *nlh, 2000 struct netlink_skb_parms *req) 2001 { 2002 struct sk_buff *skb; 2003 int size = NLMSG_SPACE(sizeof(struct rtmsg)+256); 2004 u32 pid = current->pid; 2005 u32 seq = 0; 2006 2007 if (req) 2008 pid = req->pid; 2009 if (nlh) 2010 seq = nlh->nlmsg_seq; 2011 2012 skb = alloc_skb(size, gfp_any()); 2013 if (!skb) { 2014 netlink_set_err(rtnl, 0, RTNLGRP_IPV6_ROUTE, ENOBUFS); 2015 return; 2016 } 2017 if (rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0) < 0) { 2018 kfree_skb(skb); 2019 netlink_set_err(rtnl, 0, RTNLGRP_IPV6_ROUTE, EINVAL); 2020 return; 2021 } 2022 NETLINK_CB(skb).dst_group = RTNLGRP_IPV6_ROUTE; 2023 netlink_broadcast(rtnl, skb, 0, RTNLGRP_IPV6_ROUTE, gfp_any()); 2024 } 2025 2026 /* 2027 * /proc 2028 */ 2029 2030 #ifdef CONFIG_PROC_FS 2031 2032 #define RT6_INFO_LEN (32 + 4 + 32 + 4 + 32 + 40 + 5 + 1) 2033 2034 struct rt6_proc_arg 2035 { 2036 char *buffer; 2037 int offset; 2038 int length; 2039 int skip; 2040 int len; 2041 }; 2042 2043 static int rt6_info_route(struct rt6_info *rt, void *p_arg) 2044 { 2045 struct rt6_proc_arg *arg = (struct rt6_proc_arg *) p_arg; 2046 int i; 2047 2048 if (arg->skip < arg->offset / RT6_INFO_LEN) { 2049 arg->skip++; 2050 return 0; 2051 } 2052 2053 if (arg->len >= arg->length) 2054 return 0; 2055 2056 for (i=0; i<16; i++) { 2057 sprintf(arg->buffer + arg->len, "%02x", 2058 rt->rt6i_dst.addr.s6_addr[i]); 2059 arg->len += 2; 2060 } 2061 arg->len += sprintf(arg->buffer + arg->len, " %02x ", 2062 rt->rt6i_dst.plen); 2063 2064 #ifdef CONFIG_IPV6_SUBTREES 2065 for (i=0; i<16; i++) { 2066 sprintf(arg->buffer + arg->len, "%02x", 2067 rt->rt6i_src.addr.s6_addr[i]); 2068 arg->len += 2; 2069 } 2070 arg->len += sprintf(arg->buffer + arg->len, " %02x ", 2071 rt->rt6i_src.plen); 2072 #else 2073 sprintf(arg->buffer + arg->len, 2074 "00000000000000000000000000000000 00 "); 2075 arg->len += 36; 2076 #endif 2077 2078 if (rt->rt6i_nexthop) { 2079 for (i=0; i<16; i++) { 2080 sprintf(arg->buffer + arg->len, "%02x", 2081 rt->rt6i_nexthop->primary_key[i]); 2082 arg->len += 2; 2083 } 2084 } else { 2085 sprintf(arg->buffer + arg->len, 2086 "00000000000000000000000000000000"); 2087 arg->len += 32; 2088 } 2089 arg->len += sprintf(arg->buffer + arg->len, 2090 " %08x %08x %08x %08x %8s\n", 2091 rt->rt6i_metric, atomic_read(&rt->u.dst.__refcnt), 2092 rt->u.dst.__use, rt->rt6i_flags, 2093 rt->rt6i_dev ? rt->rt6i_dev->name : ""); 2094 return 0; 2095 } 2096 2097 static int rt6_proc_info(char *buffer, char **start, off_t offset, int length) 2098 { 2099 struct rt6_proc_arg arg; 2100 arg.buffer = buffer; 2101 arg.offset = offset; 2102 arg.length = length; 2103 arg.skip = 0; 2104 arg.len = 0; 2105 2106 read_lock_bh(&rt6_lock); 2107 fib6_clean_tree(&ip6_routing_table, rt6_info_route, 0, &arg); 2108 read_unlock_bh(&rt6_lock); 2109 2110 *start = buffer; 2111 if (offset) 2112 *start += offset % RT6_INFO_LEN; 2113 2114 arg.len -= offset % RT6_INFO_LEN; 2115 2116 if (arg.len > length) 2117 arg.len = length; 2118 if (arg.len < 0) 2119 arg.len = 0; 2120 2121 return arg.len; 2122 } 2123 2124 static int rt6_stats_seq_show(struct seq_file *seq, void *v) 2125 { 2126 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", 2127 rt6_stats.fib_nodes, rt6_stats.fib_route_nodes, 2128 rt6_stats.fib_rt_alloc, rt6_stats.fib_rt_entries, 2129 rt6_stats.fib_rt_cache, 2130 atomic_read(&ip6_dst_ops.entries), 2131 rt6_stats.fib_discarded_routes); 2132 2133 return 0; 2134 } 2135 2136 static int rt6_stats_seq_open(struct inode *inode, struct file *file) 2137 { 2138 return single_open(file, rt6_stats_seq_show, NULL); 2139 } 2140 2141 static struct file_operations rt6_stats_seq_fops = { 2142 .owner = THIS_MODULE, 2143 .open = rt6_stats_seq_open, 2144 .read = seq_read, 2145 .llseek = seq_lseek, 2146 .release = single_release, 2147 }; 2148 #endif /* CONFIG_PROC_FS */ 2149 2150 #ifdef CONFIG_SYSCTL 2151 2152 static int flush_delay; 2153 2154 static 2155 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, struct file * filp, 2156 void __user *buffer, size_t *lenp, loff_t *ppos) 2157 { 2158 if (write) { 2159 proc_dointvec(ctl, write, filp, buffer, lenp, ppos); 2160 fib6_run_gc(flush_delay <= 0 ? ~0UL : (unsigned long)flush_delay); 2161 return 0; 2162 } else 2163 return -EINVAL; 2164 } 2165 2166 ctl_table ipv6_route_table[] = { 2167 { 2168 .ctl_name = NET_IPV6_ROUTE_FLUSH, 2169 .procname = "flush", 2170 .data = &flush_delay, 2171 .maxlen = sizeof(int), 2172 .mode = 0200, 2173 .proc_handler = &ipv6_sysctl_rtcache_flush 2174 }, 2175 { 2176 .ctl_name = NET_IPV6_ROUTE_GC_THRESH, 2177 .procname = "gc_thresh", 2178 .data = &ip6_dst_ops.gc_thresh, 2179 .maxlen = sizeof(int), 2180 .mode = 0644, 2181 .proc_handler = &proc_dointvec, 2182 }, 2183 { 2184 .ctl_name = NET_IPV6_ROUTE_MAX_SIZE, 2185 .procname = "max_size", 2186 .data = &ip6_rt_max_size, 2187 .maxlen = sizeof(int), 2188 .mode = 0644, 2189 .proc_handler = &proc_dointvec, 2190 }, 2191 { 2192 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL, 2193 .procname = "gc_min_interval", 2194 .data = &ip6_rt_gc_min_interval, 2195 .maxlen = sizeof(int), 2196 .mode = 0644, 2197 .proc_handler = &proc_dointvec_jiffies, 2198 .strategy = &sysctl_jiffies, 2199 }, 2200 { 2201 .ctl_name = NET_IPV6_ROUTE_GC_TIMEOUT, 2202 .procname = "gc_timeout", 2203 .data = &ip6_rt_gc_timeout, 2204 .maxlen = sizeof(int), 2205 .mode = 0644, 2206 .proc_handler = &proc_dointvec_jiffies, 2207 .strategy = &sysctl_jiffies, 2208 }, 2209 { 2210 .ctl_name = NET_IPV6_ROUTE_GC_INTERVAL, 2211 .procname = "gc_interval", 2212 .data = &ip6_rt_gc_interval, 2213 .maxlen = sizeof(int), 2214 .mode = 0644, 2215 .proc_handler = &proc_dointvec_jiffies, 2216 .strategy = &sysctl_jiffies, 2217 }, 2218 { 2219 .ctl_name = NET_IPV6_ROUTE_GC_ELASTICITY, 2220 .procname = "gc_elasticity", 2221 .data = &ip6_rt_gc_elasticity, 2222 .maxlen = sizeof(int), 2223 .mode = 0644, 2224 .proc_handler = &proc_dointvec_jiffies, 2225 .strategy = &sysctl_jiffies, 2226 }, 2227 { 2228 .ctl_name = NET_IPV6_ROUTE_MTU_EXPIRES, 2229 .procname = "mtu_expires", 2230 .data = &ip6_rt_mtu_expires, 2231 .maxlen = sizeof(int), 2232 .mode = 0644, 2233 .proc_handler = &proc_dointvec_jiffies, 2234 .strategy = &sysctl_jiffies, 2235 }, 2236 { 2237 .ctl_name = NET_IPV6_ROUTE_MIN_ADVMSS, 2238 .procname = "min_adv_mss", 2239 .data = &ip6_rt_min_advmss, 2240 .maxlen = sizeof(int), 2241 .mode = 0644, 2242 .proc_handler = &proc_dointvec_jiffies, 2243 .strategy = &sysctl_jiffies, 2244 }, 2245 { 2246 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL_MS, 2247 .procname = "gc_min_interval_ms", 2248 .data = &ip6_rt_gc_min_interval, 2249 .maxlen = sizeof(int), 2250 .mode = 0644, 2251 .proc_handler = &proc_dointvec_ms_jiffies, 2252 .strategy = &sysctl_ms_jiffies, 2253 }, 2254 { .ctl_name = 0 } 2255 }; 2256 2257 #endif 2258 2259 void __init ip6_route_init(void) 2260 { 2261 struct proc_dir_entry *p; 2262 2263 ip6_dst_ops.kmem_cachep = kmem_cache_create("ip6_dst_cache", 2264 sizeof(struct rt6_info), 2265 0, SLAB_HWCACHE_ALIGN, 2266 NULL, NULL); 2267 if (!ip6_dst_ops.kmem_cachep) 2268 panic("cannot create ip6_dst_cache"); 2269 2270 fib6_init(); 2271 #ifdef CONFIG_PROC_FS 2272 p = proc_net_create("ipv6_route", 0, rt6_proc_info); 2273 if (p) 2274 p->owner = THIS_MODULE; 2275 2276 proc_net_fops_create("rt6_stats", S_IRUGO, &rt6_stats_seq_fops); 2277 #endif 2278 #ifdef CONFIG_XFRM 2279 xfrm6_init(); 2280 #endif 2281 } 2282 2283 void ip6_route_cleanup(void) 2284 { 2285 #ifdef CONFIG_PROC_FS 2286 proc_net_remove("ipv6_route"); 2287 proc_net_remove("rt6_stats"); 2288 #endif 2289 #ifdef CONFIG_XFRM 2290 xfrm6_fini(); 2291 #endif 2292 rt6_ifdown(NULL); 2293 fib6_gc_cleanup(); 2294 kmem_cache_destroy(ip6_dst_ops.kmem_cachep); 2295 } 2296