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