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/config.h> 29 #include <linux/errno.h> 30 #include <linux/types.h> 31 #include <linux/times.h> 32 #include <linux/socket.h> 33 #include <linux/sockios.h> 34 #include <linux/net.h> 35 #include <linux/route.h> 36 #include <linux/netdevice.h> 37 #include <linux/in6.h> 38 #include <linux/init.h> 39 #include <linux/netlink.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 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 spinlock_t lock = SPIN_LOCK_UNLOCKED; 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 } 747 } 748 749 /* Protected by rt6_lock. */ 750 static struct dst_entry *ndisc_dst_gc_list; 751 static int ipv6_get_mtu(struct net_device *dev); 752 753 static inline unsigned int ipv6_advmss(unsigned int mtu) 754 { 755 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); 756 757 if (mtu < ip6_rt_min_advmss) 758 mtu = ip6_rt_min_advmss; 759 760 /* 761 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and 762 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. 763 * IPV6_MAXPLEN is also valid and means: "any MSS, 764 * rely only on pmtu discovery" 765 */ 766 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) 767 mtu = IPV6_MAXPLEN; 768 return mtu; 769 } 770 771 struct dst_entry *ndisc_dst_alloc(struct net_device *dev, 772 struct neighbour *neigh, 773 struct in6_addr *addr, 774 int (*output)(struct sk_buff *)) 775 { 776 struct rt6_info *rt; 777 struct inet6_dev *idev = in6_dev_get(dev); 778 779 if (unlikely(idev == NULL)) 780 return NULL; 781 782 rt = ip6_dst_alloc(); 783 if (unlikely(rt == NULL)) { 784 in6_dev_put(idev); 785 goto out; 786 } 787 788 dev_hold(dev); 789 if (neigh) 790 neigh_hold(neigh); 791 else 792 neigh = ndisc_get_neigh(dev, addr); 793 794 rt->rt6i_dev = dev; 795 rt->rt6i_idev = idev; 796 rt->rt6i_nexthop = neigh; 797 atomic_set(&rt->u.dst.__refcnt, 1); 798 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = 255; 799 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev); 800 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 801 rt->u.dst.output = output; 802 803 #if 0 /* there's no chance to use these for ndisc */ 804 rt->u.dst.flags = ipv6_addr_type(addr) & IPV6_ADDR_UNICAST 805 ? DST_HOST 806 : 0; 807 ipv6_addr_copy(&rt->rt6i_dst.addr, addr); 808 rt->rt6i_dst.plen = 128; 809 #endif 810 811 write_lock_bh(&rt6_lock); 812 rt->u.dst.next = ndisc_dst_gc_list; 813 ndisc_dst_gc_list = &rt->u.dst; 814 write_unlock_bh(&rt6_lock); 815 816 fib6_force_start_gc(); 817 818 out: 819 return (struct dst_entry *)rt; 820 } 821 822 int ndisc_dst_gc(int *more) 823 { 824 struct dst_entry *dst, *next, **pprev; 825 int freed; 826 827 next = NULL; 828 pprev = &ndisc_dst_gc_list; 829 freed = 0; 830 while ((dst = *pprev) != NULL) { 831 if (!atomic_read(&dst->__refcnt)) { 832 *pprev = dst->next; 833 dst_free(dst); 834 freed++; 835 } else { 836 pprev = &dst->next; 837 (*more)++; 838 } 839 } 840 841 return freed; 842 } 843 844 static int ip6_dst_gc(void) 845 { 846 static unsigned expire = 30*HZ; 847 static unsigned long last_gc; 848 unsigned long now = jiffies; 849 850 if (time_after(last_gc + ip6_rt_gc_min_interval, now) && 851 atomic_read(&ip6_dst_ops.entries) <= ip6_rt_max_size) 852 goto out; 853 854 expire++; 855 fib6_run_gc(expire); 856 last_gc = now; 857 if (atomic_read(&ip6_dst_ops.entries) < ip6_dst_ops.gc_thresh) 858 expire = ip6_rt_gc_timeout>>1; 859 860 out: 861 expire -= expire>>ip6_rt_gc_elasticity; 862 return (atomic_read(&ip6_dst_ops.entries) > ip6_rt_max_size); 863 } 864 865 /* Clean host part of a prefix. Not necessary in radix tree, 866 but results in cleaner routing tables. 867 868 Remove it only when all the things will work! 869 */ 870 871 static int ipv6_get_mtu(struct net_device *dev) 872 { 873 int mtu = IPV6_MIN_MTU; 874 struct inet6_dev *idev; 875 876 idev = in6_dev_get(dev); 877 if (idev) { 878 mtu = idev->cnf.mtu6; 879 in6_dev_put(idev); 880 } 881 return mtu; 882 } 883 884 int ipv6_get_hoplimit(struct net_device *dev) 885 { 886 int hoplimit = ipv6_devconf.hop_limit; 887 struct inet6_dev *idev; 888 889 idev = in6_dev_get(dev); 890 if (idev) { 891 hoplimit = idev->cnf.hop_limit; 892 in6_dev_put(idev); 893 } 894 return hoplimit; 895 } 896 897 /* 898 * 899 */ 900 901 int ip6_route_add(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, 902 void *_rtattr, struct netlink_skb_parms *req) 903 { 904 int err; 905 struct rtmsg *r; 906 struct rtattr **rta; 907 struct rt6_info *rt = NULL; 908 struct net_device *dev = NULL; 909 struct inet6_dev *idev = NULL; 910 int addr_type; 911 912 rta = (struct rtattr **) _rtattr; 913 914 if (rtmsg->rtmsg_dst_len > 128 || rtmsg->rtmsg_src_len > 128) 915 return -EINVAL; 916 #ifndef CONFIG_IPV6_SUBTREES 917 if (rtmsg->rtmsg_src_len) 918 return -EINVAL; 919 #endif 920 if (rtmsg->rtmsg_ifindex) { 921 err = -ENODEV; 922 dev = dev_get_by_index(rtmsg->rtmsg_ifindex); 923 if (!dev) 924 goto out; 925 idev = in6_dev_get(dev); 926 if (!idev) 927 goto out; 928 } 929 930 if (rtmsg->rtmsg_metric == 0) 931 rtmsg->rtmsg_metric = IP6_RT_PRIO_USER; 932 933 rt = ip6_dst_alloc(); 934 935 if (rt == NULL) { 936 err = -ENOMEM; 937 goto out; 938 } 939 940 rt->u.dst.obsolete = -1; 941 rt->rt6i_expires = jiffies + clock_t_to_jiffies(rtmsg->rtmsg_info); 942 if (nlh && (r = NLMSG_DATA(nlh))) { 943 rt->rt6i_protocol = r->rtm_protocol; 944 } else { 945 rt->rt6i_protocol = RTPROT_BOOT; 946 } 947 948 addr_type = ipv6_addr_type(&rtmsg->rtmsg_dst); 949 950 if (addr_type & IPV6_ADDR_MULTICAST) 951 rt->u.dst.input = ip6_mc_input; 952 else 953 rt->u.dst.input = ip6_forward; 954 955 rt->u.dst.output = ip6_output; 956 957 ipv6_addr_prefix(&rt->rt6i_dst.addr, 958 &rtmsg->rtmsg_dst, rtmsg->rtmsg_dst_len); 959 rt->rt6i_dst.plen = rtmsg->rtmsg_dst_len; 960 if (rt->rt6i_dst.plen == 128) 961 rt->u.dst.flags = DST_HOST; 962 963 #ifdef CONFIG_IPV6_SUBTREES 964 ipv6_addr_prefix(&rt->rt6i_src.addr, 965 &rtmsg->rtmsg_src, rtmsg->rtmsg_src_len); 966 rt->rt6i_src.plen = rtmsg->rtmsg_src_len; 967 #endif 968 969 rt->rt6i_metric = rtmsg->rtmsg_metric; 970 971 /* We cannot add true routes via loopback here, 972 they would result in kernel looping; promote them to reject routes 973 */ 974 if ((rtmsg->rtmsg_flags&RTF_REJECT) || 975 (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) { 976 /* hold loopback dev/idev if we haven't done so. */ 977 if (dev != &loopback_dev) { 978 if (dev) { 979 dev_put(dev); 980 in6_dev_put(idev); 981 } 982 dev = &loopback_dev; 983 dev_hold(dev); 984 idev = in6_dev_get(dev); 985 if (!idev) { 986 err = -ENODEV; 987 goto out; 988 } 989 } 990 rt->u.dst.output = ip6_pkt_discard_out; 991 rt->u.dst.input = ip6_pkt_discard; 992 rt->u.dst.error = -ENETUNREACH; 993 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP; 994 goto install_route; 995 } 996 997 if (rtmsg->rtmsg_flags & RTF_GATEWAY) { 998 struct in6_addr *gw_addr; 999 int gwa_type; 1000 1001 gw_addr = &rtmsg->rtmsg_gateway; 1002 ipv6_addr_copy(&rt->rt6i_gateway, &rtmsg->rtmsg_gateway); 1003 gwa_type = ipv6_addr_type(gw_addr); 1004 1005 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) { 1006 struct rt6_info *grt; 1007 1008 /* IPv6 strictly inhibits using not link-local 1009 addresses as nexthop address. 1010 Otherwise, router will not able to send redirects. 1011 It is very good, but in some (rare!) circumstances 1012 (SIT, PtP, NBMA NOARP links) it is handy to allow 1013 some exceptions. --ANK 1014 */ 1015 err = -EINVAL; 1016 if (!(gwa_type&IPV6_ADDR_UNICAST)) 1017 goto out; 1018 1019 grt = rt6_lookup(gw_addr, NULL, rtmsg->rtmsg_ifindex, 1); 1020 1021 err = -EHOSTUNREACH; 1022 if (grt == NULL) 1023 goto out; 1024 if (dev) { 1025 if (dev != grt->rt6i_dev) { 1026 dst_release(&grt->u.dst); 1027 goto out; 1028 } 1029 } else { 1030 dev = grt->rt6i_dev; 1031 idev = grt->rt6i_idev; 1032 dev_hold(dev); 1033 in6_dev_hold(grt->rt6i_idev); 1034 } 1035 if (!(grt->rt6i_flags&RTF_GATEWAY)) 1036 err = 0; 1037 dst_release(&grt->u.dst); 1038 1039 if (err) 1040 goto out; 1041 } 1042 err = -EINVAL; 1043 if (dev == NULL || (dev->flags&IFF_LOOPBACK)) 1044 goto out; 1045 } 1046 1047 err = -ENODEV; 1048 if (dev == NULL) 1049 goto out; 1050 1051 if (rtmsg->rtmsg_flags & (RTF_GATEWAY|RTF_NONEXTHOP)) { 1052 rt->rt6i_nexthop = __neigh_lookup_errno(&nd_tbl, &rt->rt6i_gateway, dev); 1053 if (IS_ERR(rt->rt6i_nexthop)) { 1054 err = PTR_ERR(rt->rt6i_nexthop); 1055 rt->rt6i_nexthop = NULL; 1056 goto out; 1057 } 1058 } 1059 1060 rt->rt6i_flags = rtmsg->rtmsg_flags; 1061 1062 install_route: 1063 if (rta && rta[RTA_METRICS-1]) { 1064 int attrlen = RTA_PAYLOAD(rta[RTA_METRICS-1]); 1065 struct rtattr *attr = RTA_DATA(rta[RTA_METRICS-1]); 1066 1067 while (RTA_OK(attr, attrlen)) { 1068 unsigned flavor = attr->rta_type; 1069 if (flavor) { 1070 if (flavor > RTAX_MAX) { 1071 err = -EINVAL; 1072 goto out; 1073 } 1074 rt->u.dst.metrics[flavor-1] = 1075 *(u32 *)RTA_DATA(attr); 1076 } 1077 attr = RTA_NEXT(attr, attrlen); 1078 } 1079 } 1080 1081 if (rt->u.dst.metrics[RTAX_HOPLIMIT-1] == 0) 1082 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1; 1083 if (!rt->u.dst.metrics[RTAX_MTU-1]) 1084 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(dev); 1085 if (!rt->u.dst.metrics[RTAX_ADVMSS-1]) 1086 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 1087 rt->u.dst.dev = dev; 1088 rt->rt6i_idev = idev; 1089 return ip6_ins_rt(rt, nlh, _rtattr, req); 1090 1091 out: 1092 if (dev) 1093 dev_put(dev); 1094 if (idev) 1095 in6_dev_put(idev); 1096 if (rt) 1097 dst_free((struct dst_entry *) rt); 1098 return err; 1099 } 1100 1101 int ip6_del_rt(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) 1102 { 1103 int err; 1104 1105 write_lock_bh(&rt6_lock); 1106 1107 err = fib6_del(rt, nlh, _rtattr, req); 1108 dst_release(&rt->u.dst); 1109 1110 write_unlock_bh(&rt6_lock); 1111 1112 return err; 1113 } 1114 1115 static int ip6_route_del(struct in6_rtmsg *rtmsg, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req) 1116 { 1117 struct fib6_node *fn; 1118 struct rt6_info *rt; 1119 int err = -ESRCH; 1120 1121 read_lock_bh(&rt6_lock); 1122 1123 fn = fib6_locate(&ip6_routing_table, 1124 &rtmsg->rtmsg_dst, rtmsg->rtmsg_dst_len, 1125 &rtmsg->rtmsg_src, rtmsg->rtmsg_src_len); 1126 1127 if (fn) { 1128 for (rt = fn->leaf; rt; rt = rt->u.next) { 1129 if (rtmsg->rtmsg_ifindex && 1130 (rt->rt6i_dev == NULL || 1131 rt->rt6i_dev->ifindex != rtmsg->rtmsg_ifindex)) 1132 continue; 1133 if (rtmsg->rtmsg_flags&RTF_GATEWAY && 1134 !ipv6_addr_equal(&rtmsg->rtmsg_gateway, &rt->rt6i_gateway)) 1135 continue; 1136 if (rtmsg->rtmsg_metric && 1137 rtmsg->rtmsg_metric != rt->rt6i_metric) 1138 continue; 1139 dst_hold(&rt->u.dst); 1140 read_unlock_bh(&rt6_lock); 1141 1142 return ip6_del_rt(rt, nlh, _rtattr, req); 1143 } 1144 } 1145 read_unlock_bh(&rt6_lock); 1146 1147 return err; 1148 } 1149 1150 /* 1151 * Handle redirects 1152 */ 1153 void rt6_redirect(struct in6_addr *dest, struct in6_addr *saddr, 1154 struct neighbour *neigh, u8 *lladdr, int on_link) 1155 { 1156 struct rt6_info *rt, *nrt = NULL; 1157 int strict; 1158 struct fib6_node *fn; 1159 1160 /* 1161 * Get the "current" route for this destination and 1162 * check if the redirect has come from approriate router. 1163 * 1164 * RFC 2461 specifies that redirects should only be 1165 * accepted if they come from the nexthop to the target. 1166 * Due to the way the routes are chosen, this notion 1167 * is a bit fuzzy and one might need to check all possible 1168 * routes. 1169 */ 1170 strict = ipv6_addr_type(dest) & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL); 1171 1172 read_lock_bh(&rt6_lock); 1173 fn = fib6_lookup(&ip6_routing_table, dest, NULL); 1174 restart: 1175 for (rt = fn->leaf; rt; rt = rt->u.next) { 1176 /* 1177 * Current route is on-link; redirect is always invalid. 1178 * 1179 * Seems, previous statement is not true. It could 1180 * be node, which looks for us as on-link (f.e. proxy ndisc) 1181 * But then router serving it might decide, that we should 1182 * know truth 8)8) --ANK (980726). 1183 */ 1184 if (rt6_check_expired(rt)) 1185 continue; 1186 if (!(rt->rt6i_flags & RTF_GATEWAY)) 1187 continue; 1188 if (neigh->dev != rt->rt6i_dev) 1189 continue; 1190 if (!ipv6_addr_equal(saddr, &rt->rt6i_gateway)) 1191 continue; 1192 break; 1193 } 1194 if (rt) 1195 dst_hold(&rt->u.dst); 1196 else if (strict) { 1197 while ((fn = fn->parent) != NULL) { 1198 if (fn->fn_flags & RTN_ROOT) 1199 break; 1200 if (fn->fn_flags & RTN_RTINFO) 1201 goto restart; 1202 } 1203 } 1204 read_unlock_bh(&rt6_lock); 1205 1206 if (!rt) { 1207 if (net_ratelimit()) 1208 printk(KERN_DEBUG "rt6_redirect: source isn't a valid nexthop " 1209 "for redirect target\n"); 1210 return; 1211 } 1212 1213 /* 1214 * We have finally decided to accept it. 1215 */ 1216 1217 neigh_update(neigh, lladdr, NUD_STALE, 1218 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1219 NEIGH_UPDATE_F_OVERRIDE| 1220 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1221 NEIGH_UPDATE_F_ISROUTER)) 1222 ); 1223 1224 /* 1225 * Redirect received -> path was valid. 1226 * Look, redirects are sent only in response to data packets, 1227 * so that this nexthop apparently is reachable. --ANK 1228 */ 1229 dst_confirm(&rt->u.dst); 1230 1231 /* Duplicate redirect: silently ignore. */ 1232 if (neigh == rt->u.dst.neighbour) 1233 goto out; 1234 1235 nrt = ip6_rt_copy(rt); 1236 if (nrt == NULL) 1237 goto out; 1238 1239 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; 1240 if (on_link) 1241 nrt->rt6i_flags &= ~RTF_GATEWAY; 1242 1243 ipv6_addr_copy(&nrt->rt6i_dst.addr, dest); 1244 nrt->rt6i_dst.plen = 128; 1245 nrt->u.dst.flags |= DST_HOST; 1246 1247 ipv6_addr_copy(&nrt->rt6i_gateway, (struct in6_addr*)neigh->primary_key); 1248 nrt->rt6i_nexthop = neigh_clone(neigh); 1249 /* Reset pmtu, it may be better */ 1250 nrt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(neigh->dev); 1251 nrt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&nrt->u.dst)); 1252 1253 if (ip6_ins_rt(nrt, NULL, NULL, NULL)) 1254 goto out; 1255 1256 if (rt->rt6i_flags&RTF_CACHE) { 1257 ip6_del_rt(rt, NULL, NULL, NULL); 1258 return; 1259 } 1260 1261 out: 1262 dst_release(&rt->u.dst); 1263 return; 1264 } 1265 1266 /* 1267 * Handle ICMP "packet too big" messages 1268 * i.e. Path MTU discovery 1269 */ 1270 1271 void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr, 1272 struct net_device *dev, u32 pmtu) 1273 { 1274 struct rt6_info *rt, *nrt; 1275 int allfrag = 0; 1276 1277 rt = rt6_lookup(daddr, saddr, dev->ifindex, 0); 1278 if (rt == NULL) 1279 return; 1280 1281 if (pmtu >= dst_mtu(&rt->u.dst)) 1282 goto out; 1283 1284 if (pmtu < IPV6_MIN_MTU) { 1285 /* 1286 * According to RFC2460, PMTU is set to the IPv6 Minimum Link 1287 * MTU (1280) and a fragment header should always be included 1288 * after a node receiving Too Big message reporting PMTU is 1289 * less than the IPv6 Minimum Link MTU. 1290 */ 1291 pmtu = IPV6_MIN_MTU; 1292 allfrag = 1; 1293 } 1294 1295 /* New mtu received -> path was valid. 1296 They are sent only in response to data packets, 1297 so that this nexthop apparently is reachable. --ANK 1298 */ 1299 dst_confirm(&rt->u.dst); 1300 1301 /* Host route. If it is static, it would be better 1302 not to override it, but add new one, so that 1303 when cache entry will expire old pmtu 1304 would return automatically. 1305 */ 1306 if (rt->rt6i_flags & RTF_CACHE) { 1307 rt->u.dst.metrics[RTAX_MTU-1] = pmtu; 1308 if (allfrag) 1309 rt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 1310 dst_set_expires(&rt->u.dst, ip6_rt_mtu_expires); 1311 rt->rt6i_flags |= RTF_MODIFIED|RTF_EXPIRES; 1312 goto out; 1313 } 1314 1315 /* Network route. 1316 Two cases are possible: 1317 1. It is connected route. Action: COW 1318 2. It is gatewayed route or NONEXTHOP route. Action: clone it. 1319 */ 1320 if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) 1321 nrt = rt6_alloc_cow(rt, daddr, saddr); 1322 else 1323 nrt = rt6_alloc_clone(rt, daddr); 1324 1325 if (nrt) { 1326 nrt->u.dst.metrics[RTAX_MTU-1] = pmtu; 1327 if (allfrag) 1328 nrt->u.dst.metrics[RTAX_FEATURES-1] |= RTAX_FEATURE_ALLFRAG; 1329 1330 /* According to RFC 1981, detecting PMTU increase shouldn't be 1331 * happened within 5 mins, the recommended timer is 10 mins. 1332 * Here this route expiration time is set to ip6_rt_mtu_expires 1333 * which is 10 mins. After 10 mins the decreased pmtu is expired 1334 * and detecting PMTU increase will be automatically happened. 1335 */ 1336 dst_set_expires(&nrt->u.dst, ip6_rt_mtu_expires); 1337 nrt->rt6i_flags |= RTF_DYNAMIC|RTF_EXPIRES; 1338 1339 ip6_ins_rt(nrt, NULL, NULL, NULL); 1340 } 1341 out: 1342 dst_release(&rt->u.dst); 1343 } 1344 1345 /* 1346 * Misc support functions 1347 */ 1348 1349 static struct rt6_info * ip6_rt_copy(struct rt6_info *ort) 1350 { 1351 struct rt6_info *rt = ip6_dst_alloc(); 1352 1353 if (rt) { 1354 rt->u.dst.input = ort->u.dst.input; 1355 rt->u.dst.output = ort->u.dst.output; 1356 1357 memcpy(rt->u.dst.metrics, ort->u.dst.metrics, RTAX_MAX*sizeof(u32)); 1358 rt->u.dst.dev = ort->u.dst.dev; 1359 if (rt->u.dst.dev) 1360 dev_hold(rt->u.dst.dev); 1361 rt->rt6i_idev = ort->rt6i_idev; 1362 if (rt->rt6i_idev) 1363 in6_dev_hold(rt->rt6i_idev); 1364 rt->u.dst.lastuse = jiffies; 1365 rt->rt6i_expires = 0; 1366 1367 ipv6_addr_copy(&rt->rt6i_gateway, &ort->rt6i_gateway); 1368 rt->rt6i_flags = ort->rt6i_flags & ~RTF_EXPIRES; 1369 rt->rt6i_metric = 0; 1370 1371 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); 1372 #ifdef CONFIG_IPV6_SUBTREES 1373 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 1374 #endif 1375 } 1376 return rt; 1377 } 1378 1379 #ifdef CONFIG_IPV6_ROUTE_INFO 1380 static struct rt6_info *rt6_get_route_info(struct in6_addr *prefix, int prefixlen, 1381 struct in6_addr *gwaddr, int ifindex) 1382 { 1383 struct fib6_node *fn; 1384 struct rt6_info *rt = NULL; 1385 1386 write_lock_bh(&rt6_lock); 1387 fn = fib6_locate(&ip6_routing_table, prefix ,prefixlen, NULL, 0); 1388 if (!fn) 1389 goto out; 1390 1391 for (rt = fn->leaf; rt; rt = rt->u.next) { 1392 if (rt->rt6i_dev->ifindex != ifindex) 1393 continue; 1394 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY)) 1395 continue; 1396 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr)) 1397 continue; 1398 dst_hold(&rt->u.dst); 1399 break; 1400 } 1401 out: 1402 write_unlock_bh(&rt6_lock); 1403 return rt; 1404 } 1405 1406 static struct rt6_info *rt6_add_route_info(struct in6_addr *prefix, int prefixlen, 1407 struct in6_addr *gwaddr, int ifindex, 1408 unsigned pref) 1409 { 1410 struct in6_rtmsg rtmsg; 1411 1412 memset(&rtmsg, 0, sizeof(rtmsg)); 1413 rtmsg.rtmsg_type = RTMSG_NEWROUTE; 1414 ipv6_addr_copy(&rtmsg.rtmsg_dst, prefix); 1415 rtmsg.rtmsg_dst_len = prefixlen; 1416 ipv6_addr_copy(&rtmsg.rtmsg_gateway, gwaddr); 1417 rtmsg.rtmsg_metric = 1024; 1418 rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | RTF_UP | RTF_PREF(pref); 1419 /* We should treat it as a default route if prefix length is 0. */ 1420 if (!prefixlen) 1421 rtmsg.rtmsg_flags |= RTF_DEFAULT; 1422 rtmsg.rtmsg_ifindex = ifindex; 1423 1424 ip6_route_add(&rtmsg, NULL, NULL, NULL); 1425 1426 return rt6_get_route_info(prefix, prefixlen, gwaddr, ifindex); 1427 } 1428 #endif 1429 1430 struct rt6_info *rt6_get_dflt_router(struct in6_addr *addr, struct net_device *dev) 1431 { 1432 struct rt6_info *rt; 1433 struct fib6_node *fn; 1434 1435 fn = &ip6_routing_table; 1436 1437 write_lock_bh(&rt6_lock); 1438 for (rt = fn->leaf; rt; rt=rt->u.next) { 1439 if (dev == rt->rt6i_dev && 1440 ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && 1441 ipv6_addr_equal(&rt->rt6i_gateway, addr)) 1442 break; 1443 } 1444 if (rt) 1445 dst_hold(&rt->u.dst); 1446 write_unlock_bh(&rt6_lock); 1447 return rt; 1448 } 1449 1450 struct rt6_info *rt6_add_dflt_router(struct in6_addr *gwaddr, 1451 struct net_device *dev, 1452 unsigned int pref) 1453 { 1454 struct in6_rtmsg rtmsg; 1455 1456 memset(&rtmsg, 0, sizeof(struct in6_rtmsg)); 1457 rtmsg.rtmsg_type = RTMSG_NEWROUTE; 1458 ipv6_addr_copy(&rtmsg.rtmsg_gateway, gwaddr); 1459 rtmsg.rtmsg_metric = 1024; 1460 rtmsg.rtmsg_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | RTF_UP | RTF_EXPIRES | 1461 RTF_PREF(pref); 1462 1463 rtmsg.rtmsg_ifindex = dev->ifindex; 1464 1465 ip6_route_add(&rtmsg, NULL, NULL, NULL); 1466 return rt6_get_dflt_router(gwaddr, dev); 1467 } 1468 1469 void rt6_purge_dflt_routers(void) 1470 { 1471 struct rt6_info *rt; 1472 1473 restart: 1474 read_lock_bh(&rt6_lock); 1475 for (rt = ip6_routing_table.leaf; rt; rt = rt->u.next) { 1476 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) { 1477 dst_hold(&rt->u.dst); 1478 1479 read_unlock_bh(&rt6_lock); 1480 1481 ip6_del_rt(rt, NULL, NULL, NULL); 1482 1483 goto restart; 1484 } 1485 } 1486 read_unlock_bh(&rt6_lock); 1487 } 1488 1489 int ipv6_route_ioctl(unsigned int cmd, void __user *arg) 1490 { 1491 struct in6_rtmsg rtmsg; 1492 int err; 1493 1494 switch(cmd) { 1495 case SIOCADDRT: /* Add a route */ 1496 case SIOCDELRT: /* Delete a route */ 1497 if (!capable(CAP_NET_ADMIN)) 1498 return -EPERM; 1499 err = copy_from_user(&rtmsg, arg, 1500 sizeof(struct in6_rtmsg)); 1501 if (err) 1502 return -EFAULT; 1503 1504 rtnl_lock(); 1505 switch (cmd) { 1506 case SIOCADDRT: 1507 err = ip6_route_add(&rtmsg, NULL, NULL, NULL); 1508 break; 1509 case SIOCDELRT: 1510 err = ip6_route_del(&rtmsg, NULL, NULL, NULL); 1511 break; 1512 default: 1513 err = -EINVAL; 1514 } 1515 rtnl_unlock(); 1516 1517 return err; 1518 }; 1519 1520 return -EINVAL; 1521 } 1522 1523 /* 1524 * Drop the packet on the floor 1525 */ 1526 1527 static int ip6_pkt_discard(struct sk_buff *skb) 1528 { 1529 IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES); 1530 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, skb->dev); 1531 kfree_skb(skb); 1532 return 0; 1533 } 1534 1535 static int ip6_pkt_discard_out(struct sk_buff *skb) 1536 { 1537 skb->dev = skb->dst->dev; 1538 return ip6_pkt_discard(skb); 1539 } 1540 1541 /* 1542 * Allocate a dst for local (unicast / anycast) address. 1543 */ 1544 1545 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev, 1546 const struct in6_addr *addr, 1547 int anycast) 1548 { 1549 struct rt6_info *rt = ip6_dst_alloc(); 1550 1551 if (rt == NULL) 1552 return ERR_PTR(-ENOMEM); 1553 1554 dev_hold(&loopback_dev); 1555 in6_dev_hold(idev); 1556 1557 rt->u.dst.flags = DST_HOST; 1558 rt->u.dst.input = ip6_input; 1559 rt->u.dst.output = ip6_output; 1560 rt->rt6i_dev = &loopback_dev; 1561 rt->rt6i_idev = idev; 1562 rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev); 1563 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst)); 1564 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = -1; 1565 rt->u.dst.obsolete = -1; 1566 1567 rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP; 1568 if (anycast) 1569 rt->rt6i_flags |= RTF_ANYCAST; 1570 else 1571 rt->rt6i_flags |= RTF_LOCAL; 1572 rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_gateway); 1573 if (rt->rt6i_nexthop == NULL) { 1574 dst_free((struct dst_entry *) rt); 1575 return ERR_PTR(-ENOMEM); 1576 } 1577 1578 ipv6_addr_copy(&rt->rt6i_dst.addr, addr); 1579 rt->rt6i_dst.plen = 128; 1580 1581 atomic_set(&rt->u.dst.__refcnt, 1); 1582 1583 return rt; 1584 } 1585 1586 static int fib6_ifdown(struct rt6_info *rt, void *arg) 1587 { 1588 if (((void*)rt->rt6i_dev == arg || arg == NULL) && 1589 rt != &ip6_null_entry) { 1590 RT6_TRACE("deleted by ifdown %p\n", rt); 1591 return -1; 1592 } 1593 return 0; 1594 } 1595 1596 void rt6_ifdown(struct net_device *dev) 1597 { 1598 write_lock_bh(&rt6_lock); 1599 fib6_clean_tree(&ip6_routing_table, fib6_ifdown, 0, dev); 1600 write_unlock_bh(&rt6_lock); 1601 } 1602 1603 struct rt6_mtu_change_arg 1604 { 1605 struct net_device *dev; 1606 unsigned mtu; 1607 }; 1608 1609 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg) 1610 { 1611 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; 1612 struct inet6_dev *idev; 1613 1614 /* In IPv6 pmtu discovery is not optional, 1615 so that RTAX_MTU lock cannot disable it. 1616 We still use this lock to block changes 1617 caused by addrconf/ndisc. 1618 */ 1619 1620 idev = __in6_dev_get(arg->dev); 1621 if (idev == NULL) 1622 return 0; 1623 1624 /* For administrative MTU increase, there is no way to discover 1625 IPv6 PMTU increase, so PMTU increase should be updated here. 1626 Since RFC 1981 doesn't include administrative MTU increase 1627 update PMTU increase is a MUST. (i.e. jumbo frame) 1628 */ 1629 /* 1630 If new MTU is less than route PMTU, this new MTU will be the 1631 lowest MTU in the path, update the route PMTU to reflect PMTU 1632 decreases; if new MTU is greater than route PMTU, and the 1633 old MTU is the lowest MTU in the path, update the route PMTU 1634 to reflect the increase. In this case if the other nodes' MTU 1635 also have the lowest MTU, TOO BIG MESSAGE will be lead to 1636 PMTU discouvery. 1637 */ 1638 if (rt->rt6i_dev == arg->dev && 1639 !dst_metric_locked(&rt->u.dst, RTAX_MTU) && 1640 (dst_mtu(&rt->u.dst) > arg->mtu || 1641 (dst_mtu(&rt->u.dst) < arg->mtu && 1642 dst_mtu(&rt->u.dst) == idev->cnf.mtu6))) 1643 rt->u.dst.metrics[RTAX_MTU-1] = arg->mtu; 1644 rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(arg->mtu); 1645 return 0; 1646 } 1647 1648 void rt6_mtu_change(struct net_device *dev, unsigned mtu) 1649 { 1650 struct rt6_mtu_change_arg arg; 1651 1652 arg.dev = dev; 1653 arg.mtu = mtu; 1654 read_lock_bh(&rt6_lock); 1655 fib6_clean_tree(&ip6_routing_table, rt6_mtu_change_route, 0, &arg); 1656 read_unlock_bh(&rt6_lock); 1657 } 1658 1659 static int inet6_rtm_to_rtmsg(struct rtmsg *r, struct rtattr **rta, 1660 struct in6_rtmsg *rtmsg) 1661 { 1662 memset(rtmsg, 0, sizeof(*rtmsg)); 1663 1664 rtmsg->rtmsg_dst_len = r->rtm_dst_len; 1665 rtmsg->rtmsg_src_len = r->rtm_src_len; 1666 rtmsg->rtmsg_flags = RTF_UP; 1667 if (r->rtm_type == RTN_UNREACHABLE) 1668 rtmsg->rtmsg_flags |= RTF_REJECT; 1669 1670 if (rta[RTA_GATEWAY-1]) { 1671 if (rta[RTA_GATEWAY-1]->rta_len != RTA_LENGTH(16)) 1672 return -EINVAL; 1673 memcpy(&rtmsg->rtmsg_gateway, RTA_DATA(rta[RTA_GATEWAY-1]), 16); 1674 rtmsg->rtmsg_flags |= RTF_GATEWAY; 1675 } 1676 if (rta[RTA_DST-1]) { 1677 if (RTA_PAYLOAD(rta[RTA_DST-1]) < ((r->rtm_dst_len+7)>>3)) 1678 return -EINVAL; 1679 memcpy(&rtmsg->rtmsg_dst, RTA_DATA(rta[RTA_DST-1]), ((r->rtm_dst_len+7)>>3)); 1680 } 1681 if (rta[RTA_SRC-1]) { 1682 if (RTA_PAYLOAD(rta[RTA_SRC-1]) < ((r->rtm_src_len+7)>>3)) 1683 return -EINVAL; 1684 memcpy(&rtmsg->rtmsg_src, RTA_DATA(rta[RTA_SRC-1]), ((r->rtm_src_len+7)>>3)); 1685 } 1686 if (rta[RTA_OIF-1]) { 1687 if (rta[RTA_OIF-1]->rta_len != RTA_LENGTH(sizeof(int))) 1688 return -EINVAL; 1689 memcpy(&rtmsg->rtmsg_ifindex, RTA_DATA(rta[RTA_OIF-1]), sizeof(int)); 1690 } 1691 if (rta[RTA_PRIORITY-1]) { 1692 if (rta[RTA_PRIORITY-1]->rta_len != RTA_LENGTH(4)) 1693 return -EINVAL; 1694 memcpy(&rtmsg->rtmsg_metric, RTA_DATA(rta[RTA_PRIORITY-1]), 4); 1695 } 1696 return 0; 1697 } 1698 1699 int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) 1700 { 1701 struct rtmsg *r = NLMSG_DATA(nlh); 1702 struct in6_rtmsg rtmsg; 1703 1704 if (inet6_rtm_to_rtmsg(r, arg, &rtmsg)) 1705 return -EINVAL; 1706 return ip6_route_del(&rtmsg, nlh, arg, &NETLINK_CB(skb)); 1707 } 1708 1709 int inet6_rtm_newroute(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_add(&rtmsg, nlh, arg, &NETLINK_CB(skb)); 1717 } 1718 1719 struct rt6_rtnl_dump_arg 1720 { 1721 struct sk_buff *skb; 1722 struct netlink_callback *cb; 1723 }; 1724 1725 static int rt6_fill_node(struct sk_buff *skb, struct rt6_info *rt, 1726 struct in6_addr *dst, struct in6_addr *src, 1727 int iif, int type, u32 pid, u32 seq, 1728 int prefix, unsigned int flags) 1729 { 1730 struct rtmsg *rtm; 1731 struct nlmsghdr *nlh; 1732 unsigned char *b = skb->tail; 1733 struct rta_cacheinfo ci; 1734 1735 if (prefix) { /* user wants prefix routes only */ 1736 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) { 1737 /* success since this is not a prefix route */ 1738 return 1; 1739 } 1740 } 1741 1742 nlh = NLMSG_NEW(skb, pid, seq, type, sizeof(*rtm), flags); 1743 rtm = NLMSG_DATA(nlh); 1744 rtm->rtm_family = AF_INET6; 1745 rtm->rtm_dst_len = rt->rt6i_dst.plen; 1746 rtm->rtm_src_len = rt->rt6i_src.plen; 1747 rtm->rtm_tos = 0; 1748 rtm->rtm_table = RT_TABLE_MAIN; 1749 if (rt->rt6i_flags&RTF_REJECT) 1750 rtm->rtm_type = RTN_UNREACHABLE; 1751 else if (rt->rt6i_dev && (rt->rt6i_dev->flags&IFF_LOOPBACK)) 1752 rtm->rtm_type = RTN_LOCAL; 1753 else 1754 rtm->rtm_type = RTN_UNICAST; 1755 rtm->rtm_flags = 0; 1756 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 1757 rtm->rtm_protocol = rt->rt6i_protocol; 1758 if (rt->rt6i_flags&RTF_DYNAMIC) 1759 rtm->rtm_protocol = RTPROT_REDIRECT; 1760 else if (rt->rt6i_flags & RTF_ADDRCONF) 1761 rtm->rtm_protocol = RTPROT_KERNEL; 1762 else if (rt->rt6i_flags&RTF_DEFAULT) 1763 rtm->rtm_protocol = RTPROT_RA; 1764 1765 if (rt->rt6i_flags&RTF_CACHE) 1766 rtm->rtm_flags |= RTM_F_CLONED; 1767 1768 if (dst) { 1769 RTA_PUT(skb, RTA_DST, 16, dst); 1770 rtm->rtm_dst_len = 128; 1771 } else if (rtm->rtm_dst_len) 1772 RTA_PUT(skb, RTA_DST, 16, &rt->rt6i_dst.addr); 1773 #ifdef CONFIG_IPV6_SUBTREES 1774 if (src) { 1775 RTA_PUT(skb, RTA_SRC, 16, src); 1776 rtm->rtm_src_len = 128; 1777 } else if (rtm->rtm_src_len) 1778 RTA_PUT(skb, RTA_SRC, 16, &rt->rt6i_src.addr); 1779 #endif 1780 if (iif) 1781 RTA_PUT(skb, RTA_IIF, 4, &iif); 1782 else if (dst) { 1783 struct in6_addr saddr_buf; 1784 if (ipv6_get_saddr(&rt->u.dst, dst, &saddr_buf) == 0) 1785 RTA_PUT(skb, RTA_PREFSRC, 16, &saddr_buf); 1786 } 1787 if (rtnetlink_put_metrics(skb, rt->u.dst.metrics) < 0) 1788 goto rtattr_failure; 1789 if (rt->u.dst.neighbour) 1790 RTA_PUT(skb, RTA_GATEWAY, 16, &rt->u.dst.neighbour->primary_key); 1791 if (rt->u.dst.dev) 1792 RTA_PUT(skb, RTA_OIF, sizeof(int), &rt->rt6i_dev->ifindex); 1793 RTA_PUT(skb, RTA_PRIORITY, 4, &rt->rt6i_metric); 1794 ci.rta_lastuse = jiffies_to_clock_t(jiffies - rt->u.dst.lastuse); 1795 if (rt->rt6i_expires) 1796 ci.rta_expires = jiffies_to_clock_t(rt->rt6i_expires - jiffies); 1797 else 1798 ci.rta_expires = 0; 1799 ci.rta_used = rt->u.dst.__use; 1800 ci.rta_clntref = atomic_read(&rt->u.dst.__refcnt); 1801 ci.rta_error = rt->u.dst.error; 1802 ci.rta_id = 0; 1803 ci.rta_ts = 0; 1804 ci.rta_tsage = 0; 1805 RTA_PUT(skb, RTA_CACHEINFO, sizeof(ci), &ci); 1806 nlh->nlmsg_len = skb->tail - b; 1807 return skb->len; 1808 1809 nlmsg_failure: 1810 rtattr_failure: 1811 skb_trim(skb, b - skb->data); 1812 return -1; 1813 } 1814 1815 static int rt6_dump_route(struct rt6_info *rt, void *p_arg) 1816 { 1817 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; 1818 int prefix; 1819 1820 if (arg->cb->nlh->nlmsg_len >= NLMSG_LENGTH(sizeof(struct rtmsg))) { 1821 struct rtmsg *rtm = NLMSG_DATA(arg->cb->nlh); 1822 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0; 1823 } else 1824 prefix = 0; 1825 1826 return rt6_fill_node(arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE, 1827 NETLINK_CB(arg->cb->skb).pid, arg->cb->nlh->nlmsg_seq, 1828 prefix, NLM_F_MULTI); 1829 } 1830 1831 static int fib6_dump_node(struct fib6_walker_t *w) 1832 { 1833 int res; 1834 struct rt6_info *rt; 1835 1836 for (rt = w->leaf; rt; rt = rt->u.next) { 1837 res = rt6_dump_route(rt, w->args); 1838 if (res < 0) { 1839 /* Frame is full, suspend walking */ 1840 w->leaf = rt; 1841 return 1; 1842 } 1843 BUG_TRAP(res!=0); 1844 } 1845 w->leaf = NULL; 1846 return 0; 1847 } 1848 1849 static void fib6_dump_end(struct netlink_callback *cb) 1850 { 1851 struct fib6_walker_t *w = (void*)cb->args[0]; 1852 1853 if (w) { 1854 cb->args[0] = 0; 1855 fib6_walker_unlink(w); 1856 kfree(w); 1857 } 1858 cb->done = (void*)cb->args[1]; 1859 cb->args[1] = 0; 1860 } 1861 1862 static int fib6_dump_done(struct netlink_callback *cb) 1863 { 1864 fib6_dump_end(cb); 1865 return cb->done ? cb->done(cb) : 0; 1866 } 1867 1868 int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) 1869 { 1870 struct rt6_rtnl_dump_arg arg; 1871 struct fib6_walker_t *w; 1872 int res; 1873 1874 arg.skb = skb; 1875 arg.cb = cb; 1876 1877 w = (void*)cb->args[0]; 1878 if (w == NULL) { 1879 /* New dump: 1880 * 1881 * 1. hook callback destructor. 1882 */ 1883 cb->args[1] = (long)cb->done; 1884 cb->done = fib6_dump_done; 1885 1886 /* 1887 * 2. allocate and initialize walker. 1888 */ 1889 w = kzalloc(sizeof(*w), GFP_ATOMIC); 1890 if (w == NULL) 1891 return -ENOMEM; 1892 RT6_TRACE("dump<%p", w); 1893 w->root = &ip6_routing_table; 1894 w->func = fib6_dump_node; 1895 w->args = &arg; 1896 cb->args[0] = (long)w; 1897 read_lock_bh(&rt6_lock); 1898 res = fib6_walk(w); 1899 read_unlock_bh(&rt6_lock); 1900 } else { 1901 w->args = &arg; 1902 read_lock_bh(&rt6_lock); 1903 res = fib6_walk_continue(w); 1904 read_unlock_bh(&rt6_lock); 1905 } 1906 #if RT6_DEBUG >= 3 1907 if (res <= 0 && skb->len == 0) 1908 RT6_TRACE("%p>dump end\n", w); 1909 #endif 1910 res = res < 0 ? res : skb->len; 1911 /* res < 0 is an error. (really, impossible) 1912 res == 0 means that dump is complete, but skb still can contain data. 1913 res > 0 dump is not complete, but frame is full. 1914 */ 1915 /* Destroy walker, if dump of this table is complete. */ 1916 if (res <= 0) 1917 fib6_dump_end(cb); 1918 return res; 1919 } 1920 1921 int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void *arg) 1922 { 1923 struct rtattr **rta = arg; 1924 int iif = 0; 1925 int err = -ENOBUFS; 1926 struct sk_buff *skb; 1927 struct flowi fl; 1928 struct rt6_info *rt; 1929 1930 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 1931 if (skb == NULL) 1932 goto out; 1933 1934 /* Reserve room for dummy headers, this skb can pass 1935 through good chunk of routing engine. 1936 */ 1937 skb->mac.raw = skb->data; 1938 skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr)); 1939 1940 memset(&fl, 0, sizeof(fl)); 1941 if (rta[RTA_SRC-1]) 1942 ipv6_addr_copy(&fl.fl6_src, 1943 (struct in6_addr*)RTA_DATA(rta[RTA_SRC-1])); 1944 if (rta[RTA_DST-1]) 1945 ipv6_addr_copy(&fl.fl6_dst, 1946 (struct in6_addr*)RTA_DATA(rta[RTA_DST-1])); 1947 1948 if (rta[RTA_IIF-1]) 1949 memcpy(&iif, RTA_DATA(rta[RTA_IIF-1]), sizeof(int)); 1950 1951 if (iif) { 1952 struct net_device *dev; 1953 dev = __dev_get_by_index(iif); 1954 if (!dev) { 1955 err = -ENODEV; 1956 goto out_free; 1957 } 1958 } 1959 1960 fl.oif = 0; 1961 if (rta[RTA_OIF-1]) 1962 memcpy(&fl.oif, RTA_DATA(rta[RTA_OIF-1]), sizeof(int)); 1963 1964 rt = (struct rt6_info*)ip6_route_output(NULL, &fl); 1965 1966 skb->dst = &rt->u.dst; 1967 1968 NETLINK_CB(skb).dst_pid = NETLINK_CB(in_skb).pid; 1969 err = rt6_fill_node(skb, rt, 1970 &fl.fl6_dst, &fl.fl6_src, 1971 iif, 1972 RTM_NEWROUTE, NETLINK_CB(in_skb).pid, 1973 nlh->nlmsg_seq, 0, 0); 1974 if (err < 0) { 1975 err = -EMSGSIZE; 1976 goto out_free; 1977 } 1978 1979 err = netlink_unicast(rtnl, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); 1980 if (err > 0) 1981 err = 0; 1982 out: 1983 return err; 1984 out_free: 1985 kfree_skb(skb); 1986 goto out; 1987 } 1988 1989 void inet6_rt_notify(int event, struct rt6_info *rt, struct nlmsghdr *nlh, 1990 struct netlink_skb_parms *req) 1991 { 1992 struct sk_buff *skb; 1993 int size = NLMSG_SPACE(sizeof(struct rtmsg)+256); 1994 u32 pid = current->pid; 1995 u32 seq = 0; 1996 1997 if (req) 1998 pid = req->pid; 1999 if (nlh) 2000 seq = nlh->nlmsg_seq; 2001 2002 skb = alloc_skb(size, gfp_any()); 2003 if (!skb) { 2004 netlink_set_err(rtnl, 0, RTNLGRP_IPV6_ROUTE, ENOBUFS); 2005 return; 2006 } 2007 if (rt6_fill_node(skb, rt, NULL, NULL, 0, event, pid, seq, 0, 0) < 0) { 2008 kfree_skb(skb); 2009 netlink_set_err(rtnl, 0, RTNLGRP_IPV6_ROUTE, EINVAL); 2010 return; 2011 } 2012 NETLINK_CB(skb).dst_group = RTNLGRP_IPV6_ROUTE; 2013 netlink_broadcast(rtnl, skb, 0, RTNLGRP_IPV6_ROUTE, gfp_any()); 2014 } 2015 2016 /* 2017 * /proc 2018 */ 2019 2020 #ifdef CONFIG_PROC_FS 2021 2022 #define RT6_INFO_LEN (32 + 4 + 32 + 4 + 32 + 40 + 5 + 1) 2023 2024 struct rt6_proc_arg 2025 { 2026 char *buffer; 2027 int offset; 2028 int length; 2029 int skip; 2030 int len; 2031 }; 2032 2033 static int rt6_info_route(struct rt6_info *rt, void *p_arg) 2034 { 2035 struct rt6_proc_arg *arg = (struct rt6_proc_arg *) p_arg; 2036 int i; 2037 2038 if (arg->skip < arg->offset / RT6_INFO_LEN) { 2039 arg->skip++; 2040 return 0; 2041 } 2042 2043 if (arg->len >= arg->length) 2044 return 0; 2045 2046 for (i=0; i<16; i++) { 2047 sprintf(arg->buffer + arg->len, "%02x", 2048 rt->rt6i_dst.addr.s6_addr[i]); 2049 arg->len += 2; 2050 } 2051 arg->len += sprintf(arg->buffer + arg->len, " %02x ", 2052 rt->rt6i_dst.plen); 2053 2054 #ifdef CONFIG_IPV6_SUBTREES 2055 for (i=0; i<16; i++) { 2056 sprintf(arg->buffer + arg->len, "%02x", 2057 rt->rt6i_src.addr.s6_addr[i]); 2058 arg->len += 2; 2059 } 2060 arg->len += sprintf(arg->buffer + arg->len, " %02x ", 2061 rt->rt6i_src.plen); 2062 #else 2063 sprintf(arg->buffer + arg->len, 2064 "00000000000000000000000000000000 00 "); 2065 arg->len += 36; 2066 #endif 2067 2068 if (rt->rt6i_nexthop) { 2069 for (i=0; i<16; i++) { 2070 sprintf(arg->buffer + arg->len, "%02x", 2071 rt->rt6i_nexthop->primary_key[i]); 2072 arg->len += 2; 2073 } 2074 } else { 2075 sprintf(arg->buffer + arg->len, 2076 "00000000000000000000000000000000"); 2077 arg->len += 32; 2078 } 2079 arg->len += sprintf(arg->buffer + arg->len, 2080 " %08x %08x %08x %08x %8s\n", 2081 rt->rt6i_metric, atomic_read(&rt->u.dst.__refcnt), 2082 rt->u.dst.__use, rt->rt6i_flags, 2083 rt->rt6i_dev ? rt->rt6i_dev->name : ""); 2084 return 0; 2085 } 2086 2087 static int rt6_proc_info(char *buffer, char **start, off_t offset, int length) 2088 { 2089 struct rt6_proc_arg arg; 2090 arg.buffer = buffer; 2091 arg.offset = offset; 2092 arg.length = length; 2093 arg.skip = 0; 2094 arg.len = 0; 2095 2096 read_lock_bh(&rt6_lock); 2097 fib6_clean_tree(&ip6_routing_table, rt6_info_route, 0, &arg); 2098 read_unlock_bh(&rt6_lock); 2099 2100 *start = buffer; 2101 if (offset) 2102 *start += offset % RT6_INFO_LEN; 2103 2104 arg.len -= offset % RT6_INFO_LEN; 2105 2106 if (arg.len > length) 2107 arg.len = length; 2108 if (arg.len < 0) 2109 arg.len = 0; 2110 2111 return arg.len; 2112 } 2113 2114 static int rt6_stats_seq_show(struct seq_file *seq, void *v) 2115 { 2116 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", 2117 rt6_stats.fib_nodes, rt6_stats.fib_route_nodes, 2118 rt6_stats.fib_rt_alloc, rt6_stats.fib_rt_entries, 2119 rt6_stats.fib_rt_cache, 2120 atomic_read(&ip6_dst_ops.entries), 2121 rt6_stats.fib_discarded_routes); 2122 2123 return 0; 2124 } 2125 2126 static int rt6_stats_seq_open(struct inode *inode, struct file *file) 2127 { 2128 return single_open(file, rt6_stats_seq_show, NULL); 2129 } 2130 2131 static struct file_operations rt6_stats_seq_fops = { 2132 .owner = THIS_MODULE, 2133 .open = rt6_stats_seq_open, 2134 .read = seq_read, 2135 .llseek = seq_lseek, 2136 .release = single_release, 2137 }; 2138 #endif /* CONFIG_PROC_FS */ 2139 2140 #ifdef CONFIG_SYSCTL 2141 2142 static int flush_delay; 2143 2144 static 2145 int ipv6_sysctl_rtcache_flush(ctl_table *ctl, int write, struct file * filp, 2146 void __user *buffer, size_t *lenp, loff_t *ppos) 2147 { 2148 if (write) { 2149 proc_dointvec(ctl, write, filp, buffer, lenp, ppos); 2150 fib6_run_gc(flush_delay <= 0 ? ~0UL : (unsigned long)flush_delay); 2151 return 0; 2152 } else 2153 return -EINVAL; 2154 } 2155 2156 ctl_table ipv6_route_table[] = { 2157 { 2158 .ctl_name = NET_IPV6_ROUTE_FLUSH, 2159 .procname = "flush", 2160 .data = &flush_delay, 2161 .maxlen = sizeof(int), 2162 .mode = 0200, 2163 .proc_handler = &ipv6_sysctl_rtcache_flush 2164 }, 2165 { 2166 .ctl_name = NET_IPV6_ROUTE_GC_THRESH, 2167 .procname = "gc_thresh", 2168 .data = &ip6_dst_ops.gc_thresh, 2169 .maxlen = sizeof(int), 2170 .mode = 0644, 2171 .proc_handler = &proc_dointvec, 2172 }, 2173 { 2174 .ctl_name = NET_IPV6_ROUTE_MAX_SIZE, 2175 .procname = "max_size", 2176 .data = &ip6_rt_max_size, 2177 .maxlen = sizeof(int), 2178 .mode = 0644, 2179 .proc_handler = &proc_dointvec, 2180 }, 2181 { 2182 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL, 2183 .procname = "gc_min_interval", 2184 .data = &ip6_rt_gc_min_interval, 2185 .maxlen = sizeof(int), 2186 .mode = 0644, 2187 .proc_handler = &proc_dointvec_jiffies, 2188 .strategy = &sysctl_jiffies, 2189 }, 2190 { 2191 .ctl_name = NET_IPV6_ROUTE_GC_TIMEOUT, 2192 .procname = "gc_timeout", 2193 .data = &ip6_rt_gc_timeout, 2194 .maxlen = sizeof(int), 2195 .mode = 0644, 2196 .proc_handler = &proc_dointvec_jiffies, 2197 .strategy = &sysctl_jiffies, 2198 }, 2199 { 2200 .ctl_name = NET_IPV6_ROUTE_GC_INTERVAL, 2201 .procname = "gc_interval", 2202 .data = &ip6_rt_gc_interval, 2203 .maxlen = sizeof(int), 2204 .mode = 0644, 2205 .proc_handler = &proc_dointvec_jiffies, 2206 .strategy = &sysctl_jiffies, 2207 }, 2208 { 2209 .ctl_name = NET_IPV6_ROUTE_GC_ELASTICITY, 2210 .procname = "gc_elasticity", 2211 .data = &ip6_rt_gc_elasticity, 2212 .maxlen = sizeof(int), 2213 .mode = 0644, 2214 .proc_handler = &proc_dointvec_jiffies, 2215 .strategy = &sysctl_jiffies, 2216 }, 2217 { 2218 .ctl_name = NET_IPV6_ROUTE_MTU_EXPIRES, 2219 .procname = "mtu_expires", 2220 .data = &ip6_rt_mtu_expires, 2221 .maxlen = sizeof(int), 2222 .mode = 0644, 2223 .proc_handler = &proc_dointvec_jiffies, 2224 .strategy = &sysctl_jiffies, 2225 }, 2226 { 2227 .ctl_name = NET_IPV6_ROUTE_MIN_ADVMSS, 2228 .procname = "min_adv_mss", 2229 .data = &ip6_rt_min_advmss, 2230 .maxlen = sizeof(int), 2231 .mode = 0644, 2232 .proc_handler = &proc_dointvec_jiffies, 2233 .strategy = &sysctl_jiffies, 2234 }, 2235 { 2236 .ctl_name = NET_IPV6_ROUTE_GC_MIN_INTERVAL_MS, 2237 .procname = "gc_min_interval_ms", 2238 .data = &ip6_rt_gc_min_interval, 2239 .maxlen = sizeof(int), 2240 .mode = 0644, 2241 .proc_handler = &proc_dointvec_ms_jiffies, 2242 .strategy = &sysctl_ms_jiffies, 2243 }, 2244 { .ctl_name = 0 } 2245 }; 2246 2247 #endif 2248 2249 void __init ip6_route_init(void) 2250 { 2251 struct proc_dir_entry *p; 2252 2253 ip6_dst_ops.kmem_cachep = kmem_cache_create("ip6_dst_cache", 2254 sizeof(struct rt6_info), 2255 0, SLAB_HWCACHE_ALIGN, 2256 NULL, NULL); 2257 if (!ip6_dst_ops.kmem_cachep) 2258 panic("cannot create ip6_dst_cache"); 2259 2260 fib6_init(); 2261 #ifdef CONFIG_PROC_FS 2262 p = proc_net_create("ipv6_route", 0, rt6_proc_info); 2263 if (p) 2264 p->owner = THIS_MODULE; 2265 2266 proc_net_fops_create("rt6_stats", S_IRUGO, &rt6_stats_seq_fops); 2267 #endif 2268 #ifdef CONFIG_XFRM 2269 xfrm6_init(); 2270 #endif 2271 } 2272 2273 void ip6_route_cleanup(void) 2274 { 2275 #ifdef CONFIG_PROC_FS 2276 proc_net_remove("ipv6_route"); 2277 proc_net_remove("rt6_stats"); 2278 #endif 2279 #ifdef CONFIG_XFRM 2280 xfrm6_fini(); 2281 #endif 2282 rt6_ifdown(NULL); 2283 fib6_gc_cleanup(); 2284 kmem_cache_destroy(ip6_dst_ops.kmem_cachep); 2285 } 2286