1 /* 2 * Linux INET6 implementation 3 * FIB front-end. 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 /* Changes: 15 * 16 * YOSHIFUJI Hideaki @USAGI 17 * reworked default router selection. 18 * - respect outgoing interface 19 * - select from (probably) reachable routers (i.e. 20 * routers in REACHABLE, STALE, DELAY or PROBE states). 21 * - always select the same router if it is (probably) 22 * reachable. otherwise, round-robin the list. 23 * Ville Nuorvala 24 * Fixed routing subtrees. 25 */ 26 27 #define pr_fmt(fmt) "IPv6: " fmt 28 29 #include <linux/capability.h> 30 #include <linux/errno.h> 31 #include <linux/export.h> 32 #include <linux/types.h> 33 #include <linux/times.h> 34 #include <linux/socket.h> 35 #include <linux/sockios.h> 36 #include <linux/net.h> 37 #include <linux/route.h> 38 #include <linux/netdevice.h> 39 #include <linux/in6.h> 40 #include <linux/mroute6.h> 41 #include <linux/init.h> 42 #include <linux/if_arp.h> 43 #include <linux/proc_fs.h> 44 #include <linux/seq_file.h> 45 #include <linux/nsproxy.h> 46 #include <linux/slab.h> 47 #include <net/net_namespace.h> 48 #include <net/snmp.h> 49 #include <net/ipv6.h> 50 #include <net/ip6_fib.h> 51 #include <net/ip6_route.h> 52 #include <net/ndisc.h> 53 #include <net/addrconf.h> 54 #include <net/tcp.h> 55 #include <linux/rtnetlink.h> 56 #include <net/dst.h> 57 #include <net/dst_metadata.h> 58 #include <net/xfrm.h> 59 #include <net/netevent.h> 60 #include <net/netlink.h> 61 #include <net/nexthop.h> 62 #include <net/lwtunnel.h> 63 #include <net/ip_tunnels.h> 64 #include <net/l3mdev.h> 65 66 #include <asm/uaccess.h> 67 68 #ifdef CONFIG_SYSCTL 69 #include <linux/sysctl.h> 70 #endif 71 72 enum rt6_nud_state { 73 RT6_NUD_FAIL_HARD = -3, 74 RT6_NUD_FAIL_PROBE = -2, 75 RT6_NUD_FAIL_DO_RR = -1, 76 RT6_NUD_SUCCEED = 1 77 }; 78 79 static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort); 80 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); 81 static unsigned int ip6_default_advmss(const struct dst_entry *dst); 82 static unsigned int ip6_mtu(const struct dst_entry *dst); 83 static struct dst_entry *ip6_negative_advice(struct dst_entry *); 84 static void ip6_dst_destroy(struct dst_entry *); 85 static void ip6_dst_ifdown(struct dst_entry *, 86 struct net_device *dev, int how); 87 static int ip6_dst_gc(struct dst_ops *ops); 88 89 static int ip6_pkt_discard(struct sk_buff *skb); 90 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb); 91 static int ip6_pkt_prohibit(struct sk_buff *skb); 92 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb); 93 static void ip6_link_failure(struct sk_buff *skb); 94 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 95 struct sk_buff *skb, u32 mtu); 96 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, 97 struct sk_buff *skb); 98 static void rt6_dst_from_metrics_check(struct rt6_info *rt); 99 static int rt6_score_route(struct rt6_info *rt, int oif, int strict); 100 101 #ifdef CONFIG_IPV6_ROUTE_INFO 102 static struct rt6_info *rt6_add_route_info(struct net *net, 103 const struct in6_addr *prefix, int prefixlen, 104 const struct in6_addr *gwaddr, int ifindex, 105 unsigned int pref); 106 static struct rt6_info *rt6_get_route_info(struct net *net, 107 const struct in6_addr *prefix, int prefixlen, 108 const struct in6_addr *gwaddr, int ifindex); 109 #endif 110 111 struct uncached_list { 112 spinlock_t lock; 113 struct list_head head; 114 }; 115 116 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list); 117 118 static void rt6_uncached_list_add(struct rt6_info *rt) 119 { 120 struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list); 121 122 rt->dst.flags |= DST_NOCACHE; 123 rt->rt6i_uncached_list = ul; 124 125 spin_lock_bh(&ul->lock); 126 list_add_tail(&rt->rt6i_uncached, &ul->head); 127 spin_unlock_bh(&ul->lock); 128 } 129 130 static void rt6_uncached_list_del(struct rt6_info *rt) 131 { 132 if (!list_empty(&rt->rt6i_uncached)) { 133 struct uncached_list *ul = rt->rt6i_uncached_list; 134 135 spin_lock_bh(&ul->lock); 136 list_del(&rt->rt6i_uncached); 137 spin_unlock_bh(&ul->lock); 138 } 139 } 140 141 static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev) 142 { 143 struct net_device *loopback_dev = net->loopback_dev; 144 int cpu; 145 146 if (dev == loopback_dev) 147 return; 148 149 for_each_possible_cpu(cpu) { 150 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); 151 struct rt6_info *rt; 152 153 spin_lock_bh(&ul->lock); 154 list_for_each_entry(rt, &ul->head, rt6i_uncached) { 155 struct inet6_dev *rt_idev = rt->rt6i_idev; 156 struct net_device *rt_dev = rt->dst.dev; 157 158 if (rt_idev->dev == dev) { 159 rt->rt6i_idev = in6_dev_get(loopback_dev); 160 in6_dev_put(rt_idev); 161 } 162 163 if (rt_dev == dev) { 164 rt->dst.dev = loopback_dev; 165 dev_hold(rt->dst.dev); 166 dev_put(rt_dev); 167 } 168 } 169 spin_unlock_bh(&ul->lock); 170 } 171 } 172 173 static u32 *rt6_pcpu_cow_metrics(struct rt6_info *rt) 174 { 175 return dst_metrics_write_ptr(rt->dst.from); 176 } 177 178 static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old) 179 { 180 struct rt6_info *rt = (struct rt6_info *)dst; 181 182 if (rt->rt6i_flags & RTF_PCPU) 183 return rt6_pcpu_cow_metrics(rt); 184 else if (rt->rt6i_flags & RTF_CACHE) 185 return NULL; 186 else 187 return dst_cow_metrics_generic(dst, old); 188 } 189 190 static inline const void *choose_neigh_daddr(struct rt6_info *rt, 191 struct sk_buff *skb, 192 const void *daddr) 193 { 194 struct in6_addr *p = &rt->rt6i_gateway; 195 196 if (!ipv6_addr_any(p)) 197 return (const void *) p; 198 else if (skb) 199 return &ipv6_hdr(skb)->daddr; 200 return daddr; 201 } 202 203 static struct neighbour *ip6_neigh_lookup(const struct dst_entry *dst, 204 struct sk_buff *skb, 205 const void *daddr) 206 { 207 struct rt6_info *rt = (struct rt6_info *) dst; 208 struct neighbour *n; 209 210 daddr = choose_neigh_daddr(rt, skb, daddr); 211 n = __ipv6_neigh_lookup(dst->dev, daddr); 212 if (n) 213 return n; 214 return neigh_create(&nd_tbl, daddr, dst->dev); 215 } 216 217 static struct dst_ops ip6_dst_ops_template = { 218 .family = AF_INET6, 219 .gc = ip6_dst_gc, 220 .gc_thresh = 1024, 221 .check = ip6_dst_check, 222 .default_advmss = ip6_default_advmss, 223 .mtu = ip6_mtu, 224 .cow_metrics = ipv6_cow_metrics, 225 .destroy = ip6_dst_destroy, 226 .ifdown = ip6_dst_ifdown, 227 .negative_advice = ip6_negative_advice, 228 .link_failure = ip6_link_failure, 229 .update_pmtu = ip6_rt_update_pmtu, 230 .redirect = rt6_do_redirect, 231 .local_out = __ip6_local_out, 232 .neigh_lookup = ip6_neigh_lookup, 233 }; 234 235 static unsigned int ip6_blackhole_mtu(const struct dst_entry *dst) 236 { 237 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU); 238 239 return mtu ? : dst->dev->mtu; 240 } 241 242 static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk, 243 struct sk_buff *skb, u32 mtu) 244 { 245 } 246 247 static void ip6_rt_blackhole_redirect(struct dst_entry *dst, struct sock *sk, 248 struct sk_buff *skb) 249 { 250 } 251 252 static struct dst_ops ip6_dst_blackhole_ops = { 253 .family = AF_INET6, 254 .destroy = ip6_dst_destroy, 255 .check = ip6_dst_check, 256 .mtu = ip6_blackhole_mtu, 257 .default_advmss = ip6_default_advmss, 258 .update_pmtu = ip6_rt_blackhole_update_pmtu, 259 .redirect = ip6_rt_blackhole_redirect, 260 .cow_metrics = dst_cow_metrics_generic, 261 .neigh_lookup = ip6_neigh_lookup, 262 }; 263 264 static const u32 ip6_template_metrics[RTAX_MAX] = { 265 [RTAX_HOPLIMIT - 1] = 0, 266 }; 267 268 static const struct rt6_info ip6_null_entry_template = { 269 .dst = { 270 .__refcnt = ATOMIC_INIT(1), 271 .__use = 1, 272 .obsolete = DST_OBSOLETE_FORCE_CHK, 273 .error = -ENETUNREACH, 274 .input = ip6_pkt_discard, 275 .output = ip6_pkt_discard_out, 276 }, 277 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 278 .rt6i_protocol = RTPROT_KERNEL, 279 .rt6i_metric = ~(u32) 0, 280 .rt6i_ref = ATOMIC_INIT(1), 281 }; 282 283 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 284 285 static const struct rt6_info ip6_prohibit_entry_template = { 286 .dst = { 287 .__refcnt = ATOMIC_INIT(1), 288 .__use = 1, 289 .obsolete = DST_OBSOLETE_FORCE_CHK, 290 .error = -EACCES, 291 .input = ip6_pkt_prohibit, 292 .output = ip6_pkt_prohibit_out, 293 }, 294 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 295 .rt6i_protocol = RTPROT_KERNEL, 296 .rt6i_metric = ~(u32) 0, 297 .rt6i_ref = ATOMIC_INIT(1), 298 }; 299 300 static const struct rt6_info ip6_blk_hole_entry_template = { 301 .dst = { 302 .__refcnt = ATOMIC_INIT(1), 303 .__use = 1, 304 .obsolete = DST_OBSOLETE_FORCE_CHK, 305 .error = -EINVAL, 306 .input = dst_discard, 307 .output = dst_discard_out, 308 }, 309 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 310 .rt6i_protocol = RTPROT_KERNEL, 311 .rt6i_metric = ~(u32) 0, 312 .rt6i_ref = ATOMIC_INIT(1), 313 }; 314 315 #endif 316 317 static void rt6_info_init(struct rt6_info *rt) 318 { 319 struct dst_entry *dst = &rt->dst; 320 321 memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst)); 322 INIT_LIST_HEAD(&rt->rt6i_siblings); 323 INIT_LIST_HEAD(&rt->rt6i_uncached); 324 } 325 326 /* allocate dst with ip6_dst_ops */ 327 static struct rt6_info *__ip6_dst_alloc(struct net *net, 328 struct net_device *dev, 329 int flags) 330 { 331 struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev, 332 0, DST_OBSOLETE_FORCE_CHK, flags); 333 334 if (rt) 335 rt6_info_init(rt); 336 337 return rt; 338 } 339 340 static struct rt6_info *ip6_dst_alloc(struct net *net, 341 struct net_device *dev, 342 int flags) 343 { 344 struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags); 345 346 if (rt) { 347 rt->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_ATOMIC); 348 if (rt->rt6i_pcpu) { 349 int cpu; 350 351 for_each_possible_cpu(cpu) { 352 struct rt6_info **p; 353 354 p = per_cpu_ptr(rt->rt6i_pcpu, cpu); 355 /* no one shares rt */ 356 *p = NULL; 357 } 358 } else { 359 dst_destroy((struct dst_entry *)rt); 360 return NULL; 361 } 362 } 363 364 return rt; 365 } 366 367 static void ip6_dst_destroy(struct dst_entry *dst) 368 { 369 struct rt6_info *rt = (struct rt6_info *)dst; 370 struct dst_entry *from = dst->from; 371 struct inet6_dev *idev; 372 373 dst_destroy_metrics_generic(dst); 374 free_percpu(rt->rt6i_pcpu); 375 rt6_uncached_list_del(rt); 376 377 idev = rt->rt6i_idev; 378 if (idev) { 379 rt->rt6i_idev = NULL; 380 in6_dev_put(idev); 381 } 382 383 dst->from = NULL; 384 dst_release(from); 385 } 386 387 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 388 int how) 389 { 390 struct rt6_info *rt = (struct rt6_info *)dst; 391 struct inet6_dev *idev = rt->rt6i_idev; 392 struct net_device *loopback_dev = 393 dev_net(dev)->loopback_dev; 394 395 if (dev != loopback_dev) { 396 if (idev && idev->dev == dev) { 397 struct inet6_dev *loopback_idev = 398 in6_dev_get(loopback_dev); 399 if (loopback_idev) { 400 rt->rt6i_idev = loopback_idev; 401 in6_dev_put(idev); 402 } 403 } 404 } 405 } 406 407 static bool rt6_check_expired(const struct rt6_info *rt) 408 { 409 if (rt->rt6i_flags & RTF_EXPIRES) { 410 if (time_after(jiffies, rt->dst.expires)) 411 return true; 412 } else if (rt->dst.from) { 413 return rt6_check_expired((struct rt6_info *) rt->dst.from); 414 } 415 return false; 416 } 417 418 /* Multipath route selection: 419 * Hash based function using packet header and flowlabel. 420 * Adapted from fib_info_hashfn() 421 */ 422 static int rt6_info_hash_nhsfn(unsigned int candidate_count, 423 const struct flowi6 *fl6) 424 { 425 return get_hash_from_flowi6(fl6) % candidate_count; 426 } 427 428 static struct rt6_info *rt6_multipath_select(struct rt6_info *match, 429 struct flowi6 *fl6, int oif, 430 int strict) 431 { 432 struct rt6_info *sibling, *next_sibling; 433 int route_choosen; 434 435 route_choosen = rt6_info_hash_nhsfn(match->rt6i_nsiblings + 1, fl6); 436 /* Don't change the route, if route_choosen == 0 437 * (siblings does not include ourself) 438 */ 439 if (route_choosen) 440 list_for_each_entry_safe(sibling, next_sibling, 441 &match->rt6i_siblings, rt6i_siblings) { 442 route_choosen--; 443 if (route_choosen == 0) { 444 if (rt6_score_route(sibling, oif, strict) < 0) 445 break; 446 match = sibling; 447 break; 448 } 449 } 450 return match; 451 } 452 453 /* 454 * Route lookup. Any table->tb6_lock is implied. 455 */ 456 457 static inline struct rt6_info *rt6_device_match(struct net *net, 458 struct rt6_info *rt, 459 const struct in6_addr *saddr, 460 int oif, 461 int flags) 462 { 463 struct rt6_info *local = NULL; 464 struct rt6_info *sprt; 465 466 if (!oif && ipv6_addr_any(saddr)) 467 goto out; 468 469 for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) { 470 struct net_device *dev = sprt->dst.dev; 471 472 if (oif) { 473 if (dev->ifindex == oif) 474 return sprt; 475 if (dev->flags & IFF_LOOPBACK) { 476 if (!sprt->rt6i_idev || 477 sprt->rt6i_idev->dev->ifindex != oif) { 478 if (flags & RT6_LOOKUP_F_IFACE) 479 continue; 480 if (local && 481 local->rt6i_idev->dev->ifindex == oif) 482 continue; 483 } 484 local = sprt; 485 } 486 } else { 487 if (ipv6_chk_addr(net, saddr, dev, 488 flags & RT6_LOOKUP_F_IFACE)) 489 return sprt; 490 } 491 } 492 493 if (oif) { 494 if (local) 495 return local; 496 497 if (flags & RT6_LOOKUP_F_IFACE) 498 return net->ipv6.ip6_null_entry; 499 } 500 out: 501 return rt; 502 } 503 504 #ifdef CONFIG_IPV6_ROUTER_PREF 505 struct __rt6_probe_work { 506 struct work_struct work; 507 struct in6_addr target; 508 struct net_device *dev; 509 }; 510 511 static void rt6_probe_deferred(struct work_struct *w) 512 { 513 struct in6_addr mcaddr; 514 struct __rt6_probe_work *work = 515 container_of(w, struct __rt6_probe_work, work); 516 517 addrconf_addr_solict_mult(&work->target, &mcaddr); 518 ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, NULL); 519 dev_put(work->dev); 520 kfree(work); 521 } 522 523 static void rt6_probe(struct rt6_info *rt) 524 { 525 struct __rt6_probe_work *work; 526 struct neighbour *neigh; 527 /* 528 * Okay, this does not seem to be appropriate 529 * for now, however, we need to check if it 530 * is really so; aka Router Reachability Probing. 531 * 532 * Router Reachability Probe MUST be rate-limited 533 * to no more than one per minute. 534 */ 535 if (!rt || !(rt->rt6i_flags & RTF_GATEWAY)) 536 return; 537 rcu_read_lock_bh(); 538 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); 539 if (neigh) { 540 if (neigh->nud_state & NUD_VALID) 541 goto out; 542 543 work = NULL; 544 write_lock(&neigh->lock); 545 if (!(neigh->nud_state & NUD_VALID) && 546 time_after(jiffies, 547 neigh->updated + 548 rt->rt6i_idev->cnf.rtr_probe_interval)) { 549 work = kmalloc(sizeof(*work), GFP_ATOMIC); 550 if (work) 551 __neigh_set_probe_once(neigh); 552 } 553 write_unlock(&neigh->lock); 554 } else { 555 work = kmalloc(sizeof(*work), GFP_ATOMIC); 556 } 557 558 if (work) { 559 INIT_WORK(&work->work, rt6_probe_deferred); 560 work->target = rt->rt6i_gateway; 561 dev_hold(rt->dst.dev); 562 work->dev = rt->dst.dev; 563 schedule_work(&work->work); 564 } 565 566 out: 567 rcu_read_unlock_bh(); 568 } 569 #else 570 static inline void rt6_probe(struct rt6_info *rt) 571 { 572 } 573 #endif 574 575 /* 576 * Default Router Selection (RFC 2461 6.3.6) 577 */ 578 static inline int rt6_check_dev(struct rt6_info *rt, int oif) 579 { 580 struct net_device *dev = rt->dst.dev; 581 if (!oif || dev->ifindex == oif) 582 return 2; 583 if ((dev->flags & IFF_LOOPBACK) && 584 rt->rt6i_idev && rt->rt6i_idev->dev->ifindex == oif) 585 return 1; 586 return 0; 587 } 588 589 static inline enum rt6_nud_state rt6_check_neigh(struct rt6_info *rt) 590 { 591 struct neighbour *neigh; 592 enum rt6_nud_state ret = RT6_NUD_FAIL_HARD; 593 594 if (rt->rt6i_flags & RTF_NONEXTHOP || 595 !(rt->rt6i_flags & RTF_GATEWAY)) 596 return RT6_NUD_SUCCEED; 597 598 rcu_read_lock_bh(); 599 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); 600 if (neigh) { 601 read_lock(&neigh->lock); 602 if (neigh->nud_state & NUD_VALID) 603 ret = RT6_NUD_SUCCEED; 604 #ifdef CONFIG_IPV6_ROUTER_PREF 605 else if (!(neigh->nud_state & NUD_FAILED)) 606 ret = RT6_NUD_SUCCEED; 607 else 608 ret = RT6_NUD_FAIL_PROBE; 609 #endif 610 read_unlock(&neigh->lock); 611 } else { 612 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ? 613 RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR; 614 } 615 rcu_read_unlock_bh(); 616 617 return ret; 618 } 619 620 static int rt6_score_route(struct rt6_info *rt, int oif, 621 int strict) 622 { 623 int m; 624 625 m = rt6_check_dev(rt, oif); 626 if (!m && (strict & RT6_LOOKUP_F_IFACE)) 627 return RT6_NUD_FAIL_HARD; 628 #ifdef CONFIG_IPV6_ROUTER_PREF 629 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(rt->rt6i_flags)) << 2; 630 #endif 631 if (strict & RT6_LOOKUP_F_REACHABLE) { 632 int n = rt6_check_neigh(rt); 633 if (n < 0) 634 return n; 635 } 636 return m; 637 } 638 639 static struct rt6_info *find_match(struct rt6_info *rt, int oif, int strict, 640 int *mpri, struct rt6_info *match, 641 bool *do_rr) 642 { 643 int m; 644 bool match_do_rr = false; 645 struct inet6_dev *idev = rt->rt6i_idev; 646 struct net_device *dev = rt->dst.dev; 647 648 if (dev && !netif_carrier_ok(dev) && 649 idev->cnf.ignore_routes_with_linkdown) 650 goto out; 651 652 if (rt6_check_expired(rt)) 653 goto out; 654 655 m = rt6_score_route(rt, oif, strict); 656 if (m == RT6_NUD_FAIL_DO_RR) { 657 match_do_rr = true; 658 m = 0; /* lowest valid score */ 659 } else if (m == RT6_NUD_FAIL_HARD) { 660 goto out; 661 } 662 663 if (strict & RT6_LOOKUP_F_REACHABLE) 664 rt6_probe(rt); 665 666 /* note that m can be RT6_NUD_FAIL_PROBE at this point */ 667 if (m > *mpri) { 668 *do_rr = match_do_rr; 669 *mpri = m; 670 match = rt; 671 } 672 out: 673 return match; 674 } 675 676 static struct rt6_info *find_rr_leaf(struct fib6_node *fn, 677 struct rt6_info *rr_head, 678 u32 metric, int oif, int strict, 679 bool *do_rr) 680 { 681 struct rt6_info *rt, *match, *cont; 682 int mpri = -1; 683 684 match = NULL; 685 cont = NULL; 686 for (rt = rr_head; rt; rt = rt->dst.rt6_next) { 687 if (rt->rt6i_metric != metric) { 688 cont = rt; 689 break; 690 } 691 692 match = find_match(rt, oif, strict, &mpri, match, do_rr); 693 } 694 695 for (rt = fn->leaf; rt && rt != rr_head; rt = rt->dst.rt6_next) { 696 if (rt->rt6i_metric != metric) { 697 cont = rt; 698 break; 699 } 700 701 match = find_match(rt, oif, strict, &mpri, match, do_rr); 702 } 703 704 if (match || !cont) 705 return match; 706 707 for (rt = cont; rt; rt = rt->dst.rt6_next) 708 match = find_match(rt, oif, strict, &mpri, match, do_rr); 709 710 return match; 711 } 712 713 static struct rt6_info *rt6_select(struct fib6_node *fn, int oif, int strict) 714 { 715 struct rt6_info *match, *rt0; 716 struct net *net; 717 bool do_rr = false; 718 719 rt0 = fn->rr_ptr; 720 if (!rt0) 721 fn->rr_ptr = rt0 = fn->leaf; 722 723 match = find_rr_leaf(fn, rt0, rt0->rt6i_metric, oif, strict, 724 &do_rr); 725 726 if (do_rr) { 727 struct rt6_info *next = rt0->dst.rt6_next; 728 729 /* no entries matched; do round-robin */ 730 if (!next || next->rt6i_metric != rt0->rt6i_metric) 731 next = fn->leaf; 732 733 if (next != rt0) 734 fn->rr_ptr = next; 735 } 736 737 net = dev_net(rt0->dst.dev); 738 return match ? match : net->ipv6.ip6_null_entry; 739 } 740 741 static bool rt6_is_gw_or_nonexthop(const struct rt6_info *rt) 742 { 743 return (rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY)); 744 } 745 746 #ifdef CONFIG_IPV6_ROUTE_INFO 747 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 748 const struct in6_addr *gwaddr) 749 { 750 struct net *net = dev_net(dev); 751 struct route_info *rinfo = (struct route_info *) opt; 752 struct in6_addr prefix_buf, *prefix; 753 unsigned int pref; 754 unsigned long lifetime; 755 struct rt6_info *rt; 756 757 if (len < sizeof(struct route_info)) { 758 return -EINVAL; 759 } 760 761 /* Sanity check for prefix_len and length */ 762 if (rinfo->length > 3) { 763 return -EINVAL; 764 } else if (rinfo->prefix_len > 128) { 765 return -EINVAL; 766 } else if (rinfo->prefix_len > 64) { 767 if (rinfo->length < 2) { 768 return -EINVAL; 769 } 770 } else if (rinfo->prefix_len > 0) { 771 if (rinfo->length < 1) { 772 return -EINVAL; 773 } 774 } 775 776 pref = rinfo->route_pref; 777 if (pref == ICMPV6_ROUTER_PREF_INVALID) 778 return -EINVAL; 779 780 lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ); 781 782 if (rinfo->length == 3) 783 prefix = (struct in6_addr *)rinfo->prefix; 784 else { 785 /* this function is safe */ 786 ipv6_addr_prefix(&prefix_buf, 787 (struct in6_addr *)rinfo->prefix, 788 rinfo->prefix_len); 789 prefix = &prefix_buf; 790 } 791 792 if (rinfo->prefix_len == 0) 793 rt = rt6_get_dflt_router(gwaddr, dev); 794 else 795 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len, 796 gwaddr, dev->ifindex); 797 798 if (rt && !lifetime) { 799 ip6_del_rt(rt); 800 rt = NULL; 801 } 802 803 if (!rt && lifetime) 804 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, dev->ifindex, 805 pref); 806 else if (rt) 807 rt->rt6i_flags = RTF_ROUTEINFO | 808 (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 809 810 if (rt) { 811 if (!addrconf_finite_timeout(lifetime)) 812 rt6_clean_expires(rt); 813 else 814 rt6_set_expires(rt, jiffies + HZ * lifetime); 815 816 ip6_rt_put(rt); 817 } 818 return 0; 819 } 820 #endif 821 822 static struct fib6_node* fib6_backtrack(struct fib6_node *fn, 823 struct in6_addr *saddr) 824 { 825 struct fib6_node *pn; 826 while (1) { 827 if (fn->fn_flags & RTN_TL_ROOT) 828 return NULL; 829 pn = fn->parent; 830 if (FIB6_SUBTREE(pn) && FIB6_SUBTREE(pn) != fn) 831 fn = fib6_lookup(FIB6_SUBTREE(pn), NULL, saddr); 832 else 833 fn = pn; 834 if (fn->fn_flags & RTN_RTINFO) 835 return fn; 836 } 837 } 838 839 static struct rt6_info *ip6_pol_route_lookup(struct net *net, 840 struct fib6_table *table, 841 struct flowi6 *fl6, int flags) 842 { 843 struct fib6_node *fn; 844 struct rt6_info *rt; 845 846 read_lock_bh(&table->tb6_lock); 847 fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 848 restart: 849 rt = fn->leaf; 850 rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags); 851 if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0) 852 rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags); 853 if (rt == net->ipv6.ip6_null_entry) { 854 fn = fib6_backtrack(fn, &fl6->saddr); 855 if (fn) 856 goto restart; 857 } 858 dst_use(&rt->dst, jiffies); 859 read_unlock_bh(&table->tb6_lock); 860 return rt; 861 862 } 863 864 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 865 int flags) 866 { 867 return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup); 868 } 869 EXPORT_SYMBOL_GPL(ip6_route_lookup); 870 871 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 872 const struct in6_addr *saddr, int oif, int strict) 873 { 874 struct flowi6 fl6 = { 875 .flowi6_oif = oif, 876 .daddr = *daddr, 877 }; 878 struct dst_entry *dst; 879 int flags = strict ? RT6_LOOKUP_F_IFACE : 0; 880 881 if (saddr) { 882 memcpy(&fl6.saddr, saddr, sizeof(*saddr)); 883 flags |= RT6_LOOKUP_F_HAS_SADDR; 884 } 885 886 dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup); 887 if (dst->error == 0) 888 return (struct rt6_info *) dst; 889 890 dst_release(dst); 891 892 return NULL; 893 } 894 EXPORT_SYMBOL(rt6_lookup); 895 896 /* ip6_ins_rt is called with FREE table->tb6_lock. 897 It takes new route entry, the addition fails by any reason the 898 route is freed. In any case, if caller does not hold it, it may 899 be destroyed. 900 */ 901 902 static int __ip6_ins_rt(struct rt6_info *rt, struct nl_info *info, 903 struct mx6_config *mxc) 904 { 905 int err; 906 struct fib6_table *table; 907 908 table = rt->rt6i_table; 909 write_lock_bh(&table->tb6_lock); 910 err = fib6_add(&table->tb6_root, rt, info, mxc); 911 write_unlock_bh(&table->tb6_lock); 912 913 return err; 914 } 915 916 int ip6_ins_rt(struct rt6_info *rt) 917 { 918 struct nl_info info = { .nl_net = dev_net(rt->dst.dev), }; 919 struct mx6_config mxc = { .mx = NULL, }; 920 921 return __ip6_ins_rt(rt, &info, &mxc); 922 } 923 924 static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort, 925 const struct in6_addr *daddr, 926 const struct in6_addr *saddr) 927 { 928 struct rt6_info *rt; 929 930 /* 931 * Clone the route. 932 */ 933 934 if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU)) 935 ort = (struct rt6_info *)ort->dst.from; 936 937 rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev, 0); 938 939 if (!rt) 940 return NULL; 941 942 ip6_rt_copy_init(rt, ort); 943 rt->rt6i_flags |= RTF_CACHE; 944 rt->rt6i_metric = 0; 945 rt->dst.flags |= DST_HOST; 946 rt->rt6i_dst.addr = *daddr; 947 rt->rt6i_dst.plen = 128; 948 949 if (!rt6_is_gw_or_nonexthop(ort)) { 950 if (ort->rt6i_dst.plen != 128 && 951 ipv6_addr_equal(&ort->rt6i_dst.addr, daddr)) 952 rt->rt6i_flags |= RTF_ANYCAST; 953 #ifdef CONFIG_IPV6_SUBTREES 954 if (rt->rt6i_src.plen && saddr) { 955 rt->rt6i_src.addr = *saddr; 956 rt->rt6i_src.plen = 128; 957 } 958 #endif 959 } 960 961 return rt; 962 } 963 964 static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt) 965 { 966 struct rt6_info *pcpu_rt; 967 968 pcpu_rt = __ip6_dst_alloc(dev_net(rt->dst.dev), 969 rt->dst.dev, rt->dst.flags); 970 971 if (!pcpu_rt) 972 return NULL; 973 ip6_rt_copy_init(pcpu_rt, rt); 974 pcpu_rt->rt6i_protocol = rt->rt6i_protocol; 975 pcpu_rt->rt6i_flags |= RTF_PCPU; 976 return pcpu_rt; 977 } 978 979 /* It should be called with read_lock_bh(&tb6_lock) acquired */ 980 static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt) 981 { 982 struct rt6_info *pcpu_rt, **p; 983 984 p = this_cpu_ptr(rt->rt6i_pcpu); 985 pcpu_rt = *p; 986 987 if (pcpu_rt) { 988 dst_hold(&pcpu_rt->dst); 989 rt6_dst_from_metrics_check(pcpu_rt); 990 } 991 return pcpu_rt; 992 } 993 994 static struct rt6_info *rt6_make_pcpu_route(struct rt6_info *rt) 995 { 996 struct fib6_table *table = rt->rt6i_table; 997 struct rt6_info *pcpu_rt, *prev, **p; 998 999 pcpu_rt = ip6_rt_pcpu_alloc(rt); 1000 if (!pcpu_rt) { 1001 struct net *net = dev_net(rt->dst.dev); 1002 1003 dst_hold(&net->ipv6.ip6_null_entry->dst); 1004 return net->ipv6.ip6_null_entry; 1005 } 1006 1007 read_lock_bh(&table->tb6_lock); 1008 if (rt->rt6i_pcpu) { 1009 p = this_cpu_ptr(rt->rt6i_pcpu); 1010 prev = cmpxchg(p, NULL, pcpu_rt); 1011 if (prev) { 1012 /* If someone did it before us, return prev instead */ 1013 dst_destroy(&pcpu_rt->dst); 1014 pcpu_rt = prev; 1015 } 1016 } else { 1017 /* rt has been removed from the fib6 tree 1018 * before we have a chance to acquire the read_lock. 1019 * In this case, don't brother to create a pcpu rt 1020 * since rt is going away anyway. The next 1021 * dst_check() will trigger a re-lookup. 1022 */ 1023 dst_destroy(&pcpu_rt->dst); 1024 pcpu_rt = rt; 1025 } 1026 dst_hold(&pcpu_rt->dst); 1027 rt6_dst_from_metrics_check(pcpu_rt); 1028 read_unlock_bh(&table->tb6_lock); 1029 return pcpu_rt; 1030 } 1031 1032 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif, 1033 struct flowi6 *fl6, int flags) 1034 { 1035 struct fib6_node *fn, *saved_fn; 1036 struct rt6_info *rt; 1037 int strict = 0; 1038 1039 strict |= flags & RT6_LOOKUP_F_IFACE; 1040 if (net->ipv6.devconf_all->forwarding == 0) 1041 strict |= RT6_LOOKUP_F_REACHABLE; 1042 1043 read_lock_bh(&table->tb6_lock); 1044 1045 fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 1046 saved_fn = fn; 1047 1048 if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) 1049 oif = 0; 1050 1051 redo_rt6_select: 1052 rt = rt6_select(fn, oif, strict); 1053 if (rt->rt6i_nsiblings) 1054 rt = rt6_multipath_select(rt, fl6, oif, strict); 1055 if (rt == net->ipv6.ip6_null_entry) { 1056 fn = fib6_backtrack(fn, &fl6->saddr); 1057 if (fn) 1058 goto redo_rt6_select; 1059 else if (strict & RT6_LOOKUP_F_REACHABLE) { 1060 /* also consider unreachable route */ 1061 strict &= ~RT6_LOOKUP_F_REACHABLE; 1062 fn = saved_fn; 1063 goto redo_rt6_select; 1064 } 1065 } 1066 1067 1068 if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) { 1069 dst_use(&rt->dst, jiffies); 1070 read_unlock_bh(&table->tb6_lock); 1071 1072 rt6_dst_from_metrics_check(rt); 1073 return rt; 1074 } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) && 1075 !(rt->rt6i_flags & RTF_GATEWAY))) { 1076 /* Create a RTF_CACHE clone which will not be 1077 * owned by the fib6 tree. It is for the special case where 1078 * the daddr in the skb during the neighbor look-up is different 1079 * from the fl6->daddr used to look-up route here. 1080 */ 1081 1082 struct rt6_info *uncached_rt; 1083 1084 dst_use(&rt->dst, jiffies); 1085 read_unlock_bh(&table->tb6_lock); 1086 1087 uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL); 1088 dst_release(&rt->dst); 1089 1090 if (uncached_rt) 1091 rt6_uncached_list_add(uncached_rt); 1092 else 1093 uncached_rt = net->ipv6.ip6_null_entry; 1094 1095 dst_hold(&uncached_rt->dst); 1096 return uncached_rt; 1097 1098 } else { 1099 /* Get a percpu copy */ 1100 1101 struct rt6_info *pcpu_rt; 1102 1103 rt->dst.lastuse = jiffies; 1104 rt->dst.__use++; 1105 pcpu_rt = rt6_get_pcpu_route(rt); 1106 1107 if (pcpu_rt) { 1108 read_unlock_bh(&table->tb6_lock); 1109 } else { 1110 /* We have to do the read_unlock first 1111 * because rt6_make_pcpu_route() may trigger 1112 * ip6_dst_gc() which will take the write_lock. 1113 */ 1114 dst_hold(&rt->dst); 1115 read_unlock_bh(&table->tb6_lock); 1116 pcpu_rt = rt6_make_pcpu_route(rt); 1117 dst_release(&rt->dst); 1118 } 1119 1120 return pcpu_rt; 1121 1122 } 1123 } 1124 1125 static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table, 1126 struct flowi6 *fl6, int flags) 1127 { 1128 return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags); 1129 } 1130 1131 static struct dst_entry *ip6_route_input_lookup(struct net *net, 1132 struct net_device *dev, 1133 struct flowi6 *fl6, int flags) 1134 { 1135 if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG) 1136 flags |= RT6_LOOKUP_F_IFACE; 1137 1138 return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_input); 1139 } 1140 1141 void ip6_route_input(struct sk_buff *skb) 1142 { 1143 const struct ipv6hdr *iph = ipv6_hdr(skb); 1144 struct net *net = dev_net(skb->dev); 1145 int flags = RT6_LOOKUP_F_HAS_SADDR; 1146 struct ip_tunnel_info *tun_info; 1147 struct flowi6 fl6 = { 1148 .flowi6_iif = l3mdev_fib_oif(skb->dev), 1149 .daddr = iph->daddr, 1150 .saddr = iph->saddr, 1151 .flowlabel = ip6_flowinfo(iph), 1152 .flowi6_mark = skb->mark, 1153 .flowi6_proto = iph->nexthdr, 1154 }; 1155 1156 tun_info = skb_tunnel_info(skb); 1157 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 1158 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id; 1159 skb_dst_drop(skb); 1160 skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags)); 1161 } 1162 1163 static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table, 1164 struct flowi6 *fl6, int flags) 1165 { 1166 return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags); 1167 } 1168 1169 struct dst_entry *ip6_route_output(struct net *net, const struct sock *sk, 1170 struct flowi6 *fl6) 1171 { 1172 struct dst_entry *dst; 1173 int flags = 0; 1174 bool any_src; 1175 1176 dst = l3mdev_rt6_dst_by_oif(net, fl6); 1177 if (dst) 1178 return dst; 1179 1180 fl6->flowi6_iif = LOOPBACK_IFINDEX; 1181 1182 any_src = ipv6_addr_any(&fl6->saddr); 1183 if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) || 1184 (fl6->flowi6_oif && any_src)) 1185 flags |= RT6_LOOKUP_F_IFACE; 1186 1187 if (!any_src) 1188 flags |= RT6_LOOKUP_F_HAS_SADDR; 1189 else if (sk) 1190 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs); 1191 1192 return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output); 1193 } 1194 EXPORT_SYMBOL(ip6_route_output); 1195 1196 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig) 1197 { 1198 struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig; 1199 struct dst_entry *new = NULL; 1200 1201 rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, DST_OBSOLETE_NONE, 0); 1202 if (rt) { 1203 rt6_info_init(rt); 1204 1205 new = &rt->dst; 1206 new->__use = 1; 1207 new->input = dst_discard; 1208 new->output = dst_discard_out; 1209 1210 dst_copy_metrics(new, &ort->dst); 1211 rt->rt6i_idev = ort->rt6i_idev; 1212 if (rt->rt6i_idev) 1213 in6_dev_hold(rt->rt6i_idev); 1214 1215 rt->rt6i_gateway = ort->rt6i_gateway; 1216 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU; 1217 rt->rt6i_metric = 0; 1218 1219 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); 1220 #ifdef CONFIG_IPV6_SUBTREES 1221 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 1222 #endif 1223 1224 dst_free(new); 1225 } 1226 1227 dst_release(dst_orig); 1228 return new ? new : ERR_PTR(-ENOMEM); 1229 } 1230 1231 /* 1232 * Destination cache support functions 1233 */ 1234 1235 static void rt6_dst_from_metrics_check(struct rt6_info *rt) 1236 { 1237 if (rt->dst.from && 1238 dst_metrics_ptr(&rt->dst) != dst_metrics_ptr(rt->dst.from)) 1239 dst_init_metrics(&rt->dst, dst_metrics_ptr(rt->dst.from), true); 1240 } 1241 1242 static struct dst_entry *rt6_check(struct rt6_info *rt, u32 cookie) 1243 { 1244 if (!rt->rt6i_node || (rt->rt6i_node->fn_sernum != cookie)) 1245 return NULL; 1246 1247 if (rt6_check_expired(rt)) 1248 return NULL; 1249 1250 return &rt->dst; 1251 } 1252 1253 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, u32 cookie) 1254 { 1255 if (rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 1256 rt6_check((struct rt6_info *)(rt->dst.from), cookie)) 1257 return &rt->dst; 1258 else 1259 return NULL; 1260 } 1261 1262 static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) 1263 { 1264 struct rt6_info *rt; 1265 1266 rt = (struct rt6_info *) dst; 1267 1268 /* All IPV6 dsts are created with ->obsolete set to the value 1269 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 1270 * into this function always. 1271 */ 1272 1273 rt6_dst_from_metrics_check(rt); 1274 1275 if ((rt->rt6i_flags & RTF_PCPU) || unlikely(dst->flags & DST_NOCACHE)) 1276 return rt6_dst_from_check(rt, cookie); 1277 else 1278 return rt6_check(rt, cookie); 1279 } 1280 1281 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) 1282 { 1283 struct rt6_info *rt = (struct rt6_info *) dst; 1284 1285 if (rt) { 1286 if (rt->rt6i_flags & RTF_CACHE) { 1287 if (rt6_check_expired(rt)) { 1288 ip6_del_rt(rt); 1289 dst = NULL; 1290 } 1291 } else { 1292 dst_release(dst); 1293 dst = NULL; 1294 } 1295 } 1296 return dst; 1297 } 1298 1299 static void ip6_link_failure(struct sk_buff *skb) 1300 { 1301 struct rt6_info *rt; 1302 1303 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); 1304 1305 rt = (struct rt6_info *) skb_dst(skb); 1306 if (rt) { 1307 if (rt->rt6i_flags & RTF_CACHE) { 1308 dst_hold(&rt->dst); 1309 ip6_del_rt(rt); 1310 } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) { 1311 rt->rt6i_node->fn_sernum = -1; 1312 } 1313 } 1314 } 1315 1316 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu) 1317 { 1318 struct net *net = dev_net(rt->dst.dev); 1319 1320 rt->rt6i_flags |= RTF_MODIFIED; 1321 rt->rt6i_pmtu = mtu; 1322 rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires); 1323 } 1324 1325 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk, 1326 const struct ipv6hdr *iph, u32 mtu) 1327 { 1328 struct rt6_info *rt6 = (struct rt6_info *)dst; 1329 1330 if (rt6->rt6i_flags & RTF_LOCAL) 1331 return; 1332 1333 dst_confirm(dst); 1334 mtu = max_t(u32, mtu, IPV6_MIN_MTU); 1335 if (mtu >= dst_mtu(dst)) 1336 return; 1337 1338 if (rt6->rt6i_flags & RTF_CACHE) { 1339 rt6_do_update_pmtu(rt6, mtu); 1340 } else { 1341 const struct in6_addr *daddr, *saddr; 1342 struct rt6_info *nrt6; 1343 1344 if (iph) { 1345 daddr = &iph->daddr; 1346 saddr = &iph->saddr; 1347 } else if (sk) { 1348 daddr = &sk->sk_v6_daddr; 1349 saddr = &inet6_sk(sk)->saddr; 1350 } else { 1351 return; 1352 } 1353 nrt6 = ip6_rt_cache_alloc(rt6, daddr, saddr); 1354 if (nrt6) { 1355 rt6_do_update_pmtu(nrt6, mtu); 1356 1357 /* ip6_ins_rt(nrt6) will bump the 1358 * rt6->rt6i_node->fn_sernum 1359 * which will fail the next rt6_check() and 1360 * invalidate the sk->sk_dst_cache. 1361 */ 1362 ip6_ins_rt(nrt6); 1363 } 1364 } 1365 } 1366 1367 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 1368 struct sk_buff *skb, u32 mtu) 1369 { 1370 __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu); 1371 } 1372 1373 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, 1374 int oif, u32 mark) 1375 { 1376 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; 1377 struct dst_entry *dst; 1378 struct flowi6 fl6; 1379 1380 memset(&fl6, 0, sizeof(fl6)); 1381 fl6.flowi6_oif = oif; 1382 fl6.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark); 1383 fl6.daddr = iph->daddr; 1384 fl6.saddr = iph->saddr; 1385 fl6.flowlabel = ip6_flowinfo(iph); 1386 1387 dst = ip6_route_output(net, NULL, &fl6); 1388 if (!dst->error) 1389 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu)); 1390 dst_release(dst); 1391 } 1392 EXPORT_SYMBOL_GPL(ip6_update_pmtu); 1393 1394 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu) 1395 { 1396 ip6_update_pmtu(skb, sock_net(sk), mtu, 1397 sk->sk_bound_dev_if, sk->sk_mark); 1398 } 1399 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu); 1400 1401 /* Handle redirects */ 1402 struct ip6rd_flowi { 1403 struct flowi6 fl6; 1404 struct in6_addr gateway; 1405 }; 1406 1407 static struct rt6_info *__ip6_route_redirect(struct net *net, 1408 struct fib6_table *table, 1409 struct flowi6 *fl6, 1410 int flags) 1411 { 1412 struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6; 1413 struct rt6_info *rt; 1414 struct fib6_node *fn; 1415 1416 /* Get the "current" route for this destination and 1417 * check if the redirect has come from approriate router. 1418 * 1419 * RFC 4861 specifies that redirects should only be 1420 * accepted if they come from the nexthop to the target. 1421 * Due to the way the routes are chosen, this notion 1422 * is a bit fuzzy and one might need to check all possible 1423 * routes. 1424 */ 1425 1426 read_lock_bh(&table->tb6_lock); 1427 fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 1428 restart: 1429 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { 1430 if (rt6_check_expired(rt)) 1431 continue; 1432 if (rt->dst.error) 1433 break; 1434 if (!(rt->rt6i_flags & RTF_GATEWAY)) 1435 continue; 1436 if (fl6->flowi6_oif != rt->dst.dev->ifindex) 1437 continue; 1438 if (!ipv6_addr_equal(&rdfl->gateway, &rt->rt6i_gateway)) 1439 continue; 1440 break; 1441 } 1442 1443 if (!rt) 1444 rt = net->ipv6.ip6_null_entry; 1445 else if (rt->dst.error) { 1446 rt = net->ipv6.ip6_null_entry; 1447 goto out; 1448 } 1449 1450 if (rt == net->ipv6.ip6_null_entry) { 1451 fn = fib6_backtrack(fn, &fl6->saddr); 1452 if (fn) 1453 goto restart; 1454 } 1455 1456 out: 1457 dst_hold(&rt->dst); 1458 1459 read_unlock_bh(&table->tb6_lock); 1460 1461 return rt; 1462 }; 1463 1464 static struct dst_entry *ip6_route_redirect(struct net *net, 1465 const struct flowi6 *fl6, 1466 const struct in6_addr *gateway) 1467 { 1468 int flags = RT6_LOOKUP_F_HAS_SADDR; 1469 struct ip6rd_flowi rdfl; 1470 1471 rdfl.fl6 = *fl6; 1472 rdfl.gateway = *gateway; 1473 1474 return fib6_rule_lookup(net, &rdfl.fl6, 1475 flags, __ip6_route_redirect); 1476 } 1477 1478 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark) 1479 { 1480 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; 1481 struct dst_entry *dst; 1482 struct flowi6 fl6; 1483 1484 memset(&fl6, 0, sizeof(fl6)); 1485 fl6.flowi6_iif = LOOPBACK_IFINDEX; 1486 fl6.flowi6_oif = oif; 1487 fl6.flowi6_mark = mark; 1488 fl6.daddr = iph->daddr; 1489 fl6.saddr = iph->saddr; 1490 fl6.flowlabel = ip6_flowinfo(iph); 1491 1492 dst = ip6_route_redirect(net, &fl6, &ipv6_hdr(skb)->saddr); 1493 rt6_do_redirect(dst, NULL, skb); 1494 dst_release(dst); 1495 } 1496 EXPORT_SYMBOL_GPL(ip6_redirect); 1497 1498 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif, 1499 u32 mark) 1500 { 1501 const struct ipv6hdr *iph = ipv6_hdr(skb); 1502 const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb); 1503 struct dst_entry *dst; 1504 struct flowi6 fl6; 1505 1506 memset(&fl6, 0, sizeof(fl6)); 1507 fl6.flowi6_iif = LOOPBACK_IFINDEX; 1508 fl6.flowi6_oif = oif; 1509 fl6.flowi6_mark = mark; 1510 fl6.daddr = msg->dest; 1511 fl6.saddr = iph->daddr; 1512 1513 dst = ip6_route_redirect(net, &fl6, &iph->saddr); 1514 rt6_do_redirect(dst, NULL, skb); 1515 dst_release(dst); 1516 } 1517 1518 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk) 1519 { 1520 ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark); 1521 } 1522 EXPORT_SYMBOL_GPL(ip6_sk_redirect); 1523 1524 static unsigned int ip6_default_advmss(const struct dst_entry *dst) 1525 { 1526 struct net_device *dev = dst->dev; 1527 unsigned int mtu = dst_mtu(dst); 1528 struct net *net = dev_net(dev); 1529 1530 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); 1531 1532 if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss) 1533 mtu = net->ipv6.sysctl.ip6_rt_min_advmss; 1534 1535 /* 1536 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and 1537 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. 1538 * IPV6_MAXPLEN is also valid and means: "any MSS, 1539 * rely only on pmtu discovery" 1540 */ 1541 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) 1542 mtu = IPV6_MAXPLEN; 1543 return mtu; 1544 } 1545 1546 static unsigned int ip6_mtu(const struct dst_entry *dst) 1547 { 1548 const struct rt6_info *rt = (const struct rt6_info *)dst; 1549 unsigned int mtu = rt->rt6i_pmtu; 1550 struct inet6_dev *idev; 1551 1552 if (mtu) 1553 goto out; 1554 1555 mtu = dst_metric_raw(dst, RTAX_MTU); 1556 if (mtu) 1557 goto out; 1558 1559 mtu = IPV6_MIN_MTU; 1560 1561 rcu_read_lock(); 1562 idev = __in6_dev_get(dst->dev); 1563 if (idev) 1564 mtu = idev->cnf.mtu6; 1565 rcu_read_unlock(); 1566 1567 out: 1568 return min_t(unsigned int, mtu, IP6_MAX_MTU); 1569 } 1570 1571 static struct dst_entry *icmp6_dst_gc_list; 1572 static DEFINE_SPINLOCK(icmp6_dst_lock); 1573 1574 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, 1575 struct flowi6 *fl6) 1576 { 1577 struct dst_entry *dst; 1578 struct rt6_info *rt; 1579 struct inet6_dev *idev = in6_dev_get(dev); 1580 struct net *net = dev_net(dev); 1581 1582 if (unlikely(!idev)) 1583 return ERR_PTR(-ENODEV); 1584 1585 rt = ip6_dst_alloc(net, dev, 0); 1586 if (unlikely(!rt)) { 1587 in6_dev_put(idev); 1588 dst = ERR_PTR(-ENOMEM); 1589 goto out; 1590 } 1591 1592 rt->dst.flags |= DST_HOST; 1593 rt->dst.output = ip6_output; 1594 atomic_set(&rt->dst.__refcnt, 1); 1595 rt->rt6i_gateway = fl6->daddr; 1596 rt->rt6i_dst.addr = fl6->daddr; 1597 rt->rt6i_dst.plen = 128; 1598 rt->rt6i_idev = idev; 1599 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0); 1600 1601 spin_lock_bh(&icmp6_dst_lock); 1602 rt->dst.next = icmp6_dst_gc_list; 1603 icmp6_dst_gc_list = &rt->dst; 1604 spin_unlock_bh(&icmp6_dst_lock); 1605 1606 fib6_force_start_gc(net); 1607 1608 dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0); 1609 1610 out: 1611 return dst; 1612 } 1613 1614 int icmp6_dst_gc(void) 1615 { 1616 struct dst_entry *dst, **pprev; 1617 int more = 0; 1618 1619 spin_lock_bh(&icmp6_dst_lock); 1620 pprev = &icmp6_dst_gc_list; 1621 1622 while ((dst = *pprev) != NULL) { 1623 if (!atomic_read(&dst->__refcnt)) { 1624 *pprev = dst->next; 1625 dst_free(dst); 1626 } else { 1627 pprev = &dst->next; 1628 ++more; 1629 } 1630 } 1631 1632 spin_unlock_bh(&icmp6_dst_lock); 1633 1634 return more; 1635 } 1636 1637 static void icmp6_clean_all(int (*func)(struct rt6_info *rt, void *arg), 1638 void *arg) 1639 { 1640 struct dst_entry *dst, **pprev; 1641 1642 spin_lock_bh(&icmp6_dst_lock); 1643 pprev = &icmp6_dst_gc_list; 1644 while ((dst = *pprev) != NULL) { 1645 struct rt6_info *rt = (struct rt6_info *) dst; 1646 if (func(rt, arg)) { 1647 *pprev = dst->next; 1648 dst_free(dst); 1649 } else { 1650 pprev = &dst->next; 1651 } 1652 } 1653 spin_unlock_bh(&icmp6_dst_lock); 1654 } 1655 1656 static int ip6_dst_gc(struct dst_ops *ops) 1657 { 1658 struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops); 1659 int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval; 1660 int rt_max_size = net->ipv6.sysctl.ip6_rt_max_size; 1661 int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity; 1662 int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout; 1663 unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc; 1664 int entries; 1665 1666 entries = dst_entries_get_fast(ops); 1667 if (time_after(rt_last_gc + rt_min_interval, jiffies) && 1668 entries <= rt_max_size) 1669 goto out; 1670 1671 net->ipv6.ip6_rt_gc_expire++; 1672 fib6_run_gc(net->ipv6.ip6_rt_gc_expire, net, true); 1673 entries = dst_entries_get_slow(ops); 1674 if (entries < ops->gc_thresh) 1675 net->ipv6.ip6_rt_gc_expire = rt_gc_timeout>>1; 1676 out: 1677 net->ipv6.ip6_rt_gc_expire -= net->ipv6.ip6_rt_gc_expire>>rt_elasticity; 1678 return entries > rt_max_size; 1679 } 1680 1681 static int ip6_convert_metrics(struct mx6_config *mxc, 1682 const struct fib6_config *cfg) 1683 { 1684 bool ecn_ca = false; 1685 struct nlattr *nla; 1686 int remaining; 1687 u32 *mp; 1688 1689 if (!cfg->fc_mx) 1690 return 0; 1691 1692 mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_KERNEL); 1693 if (unlikely(!mp)) 1694 return -ENOMEM; 1695 1696 nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) { 1697 int type = nla_type(nla); 1698 u32 val; 1699 1700 if (!type) 1701 continue; 1702 if (unlikely(type > RTAX_MAX)) 1703 goto err; 1704 1705 if (type == RTAX_CC_ALGO) { 1706 char tmp[TCP_CA_NAME_MAX]; 1707 1708 nla_strlcpy(tmp, nla, sizeof(tmp)); 1709 val = tcp_ca_get_key_by_name(tmp, &ecn_ca); 1710 if (val == TCP_CA_UNSPEC) 1711 goto err; 1712 } else { 1713 val = nla_get_u32(nla); 1714 } 1715 if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK)) 1716 goto err; 1717 1718 mp[type - 1] = val; 1719 __set_bit(type - 1, mxc->mx_valid); 1720 } 1721 1722 if (ecn_ca) { 1723 __set_bit(RTAX_FEATURES - 1, mxc->mx_valid); 1724 mp[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA; 1725 } 1726 1727 mxc->mx = mp; 1728 return 0; 1729 err: 1730 kfree(mp); 1731 return -EINVAL; 1732 } 1733 1734 static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg) 1735 { 1736 struct net *net = cfg->fc_nlinfo.nl_net; 1737 struct rt6_info *rt = NULL; 1738 struct net_device *dev = NULL; 1739 struct inet6_dev *idev = NULL; 1740 struct fib6_table *table; 1741 int addr_type; 1742 int err = -EINVAL; 1743 1744 if (cfg->fc_dst_len > 128 || cfg->fc_src_len > 128) 1745 goto out; 1746 #ifndef CONFIG_IPV6_SUBTREES 1747 if (cfg->fc_src_len) 1748 goto out; 1749 #endif 1750 if (cfg->fc_ifindex) { 1751 err = -ENODEV; 1752 dev = dev_get_by_index(net, cfg->fc_ifindex); 1753 if (!dev) 1754 goto out; 1755 idev = in6_dev_get(dev); 1756 if (!idev) 1757 goto out; 1758 } 1759 1760 if (cfg->fc_metric == 0) 1761 cfg->fc_metric = IP6_RT_PRIO_USER; 1762 1763 err = -ENOBUFS; 1764 if (cfg->fc_nlinfo.nlh && 1765 !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) { 1766 table = fib6_get_table(net, cfg->fc_table); 1767 if (!table) { 1768 pr_warn("NLM_F_CREATE should be specified when creating new route\n"); 1769 table = fib6_new_table(net, cfg->fc_table); 1770 } 1771 } else { 1772 table = fib6_new_table(net, cfg->fc_table); 1773 } 1774 1775 if (!table) 1776 goto out; 1777 1778 rt = ip6_dst_alloc(net, NULL, 1779 (cfg->fc_flags & RTF_ADDRCONF) ? 0 : DST_NOCOUNT); 1780 1781 if (!rt) { 1782 err = -ENOMEM; 1783 goto out; 1784 } 1785 1786 if (cfg->fc_flags & RTF_EXPIRES) 1787 rt6_set_expires(rt, jiffies + 1788 clock_t_to_jiffies(cfg->fc_expires)); 1789 else 1790 rt6_clean_expires(rt); 1791 1792 if (cfg->fc_protocol == RTPROT_UNSPEC) 1793 cfg->fc_protocol = RTPROT_BOOT; 1794 rt->rt6i_protocol = cfg->fc_protocol; 1795 1796 addr_type = ipv6_addr_type(&cfg->fc_dst); 1797 1798 if (addr_type & IPV6_ADDR_MULTICAST) 1799 rt->dst.input = ip6_mc_input; 1800 else if (cfg->fc_flags & RTF_LOCAL) 1801 rt->dst.input = ip6_input; 1802 else 1803 rt->dst.input = ip6_forward; 1804 1805 rt->dst.output = ip6_output; 1806 1807 if (cfg->fc_encap) { 1808 struct lwtunnel_state *lwtstate; 1809 1810 err = lwtunnel_build_state(dev, cfg->fc_encap_type, 1811 cfg->fc_encap, AF_INET6, cfg, 1812 &lwtstate); 1813 if (err) 1814 goto out; 1815 rt->dst.lwtstate = lwtstate_get(lwtstate); 1816 if (lwtunnel_output_redirect(rt->dst.lwtstate)) { 1817 rt->dst.lwtstate->orig_output = rt->dst.output; 1818 rt->dst.output = lwtunnel_output; 1819 } 1820 if (lwtunnel_input_redirect(rt->dst.lwtstate)) { 1821 rt->dst.lwtstate->orig_input = rt->dst.input; 1822 rt->dst.input = lwtunnel_input; 1823 } 1824 } 1825 1826 ipv6_addr_prefix(&rt->rt6i_dst.addr, &cfg->fc_dst, cfg->fc_dst_len); 1827 rt->rt6i_dst.plen = cfg->fc_dst_len; 1828 if (rt->rt6i_dst.plen == 128) 1829 rt->dst.flags |= DST_HOST; 1830 1831 #ifdef CONFIG_IPV6_SUBTREES 1832 ipv6_addr_prefix(&rt->rt6i_src.addr, &cfg->fc_src, cfg->fc_src_len); 1833 rt->rt6i_src.plen = cfg->fc_src_len; 1834 #endif 1835 1836 rt->rt6i_metric = cfg->fc_metric; 1837 1838 /* We cannot add true routes via loopback here, 1839 they would result in kernel looping; promote them to reject routes 1840 */ 1841 if ((cfg->fc_flags & RTF_REJECT) || 1842 (dev && (dev->flags & IFF_LOOPBACK) && 1843 !(addr_type & IPV6_ADDR_LOOPBACK) && 1844 !(cfg->fc_flags & RTF_LOCAL))) { 1845 /* hold loopback dev/idev if we haven't done so. */ 1846 if (dev != net->loopback_dev) { 1847 if (dev) { 1848 dev_put(dev); 1849 in6_dev_put(idev); 1850 } 1851 dev = net->loopback_dev; 1852 dev_hold(dev); 1853 idev = in6_dev_get(dev); 1854 if (!idev) { 1855 err = -ENODEV; 1856 goto out; 1857 } 1858 } 1859 rt->rt6i_flags = RTF_REJECT|RTF_NONEXTHOP; 1860 switch (cfg->fc_type) { 1861 case RTN_BLACKHOLE: 1862 rt->dst.error = -EINVAL; 1863 rt->dst.output = dst_discard_out; 1864 rt->dst.input = dst_discard; 1865 break; 1866 case RTN_PROHIBIT: 1867 rt->dst.error = -EACCES; 1868 rt->dst.output = ip6_pkt_prohibit_out; 1869 rt->dst.input = ip6_pkt_prohibit; 1870 break; 1871 case RTN_THROW: 1872 case RTN_UNREACHABLE: 1873 default: 1874 rt->dst.error = (cfg->fc_type == RTN_THROW) ? -EAGAIN 1875 : (cfg->fc_type == RTN_UNREACHABLE) 1876 ? -EHOSTUNREACH : -ENETUNREACH; 1877 rt->dst.output = ip6_pkt_discard_out; 1878 rt->dst.input = ip6_pkt_discard; 1879 break; 1880 } 1881 goto install_route; 1882 } 1883 1884 if (cfg->fc_flags & RTF_GATEWAY) { 1885 const struct in6_addr *gw_addr; 1886 int gwa_type; 1887 1888 gw_addr = &cfg->fc_gateway; 1889 gwa_type = ipv6_addr_type(gw_addr); 1890 1891 /* if gw_addr is local we will fail to detect this in case 1892 * address is still TENTATIVE (DAD in progress). rt6_lookup() 1893 * will return already-added prefix route via interface that 1894 * prefix route was assigned to, which might be non-loopback. 1895 */ 1896 err = -EINVAL; 1897 if (ipv6_chk_addr_and_flags(net, gw_addr, 1898 gwa_type & IPV6_ADDR_LINKLOCAL ? 1899 dev : NULL, 0, 0)) 1900 goto out; 1901 1902 rt->rt6i_gateway = *gw_addr; 1903 1904 if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) { 1905 struct rt6_info *grt; 1906 1907 /* IPv6 strictly inhibits using not link-local 1908 addresses as nexthop address. 1909 Otherwise, router will not able to send redirects. 1910 It is very good, but in some (rare!) circumstances 1911 (SIT, PtP, NBMA NOARP links) it is handy to allow 1912 some exceptions. --ANK 1913 */ 1914 if (!(gwa_type & IPV6_ADDR_UNICAST)) 1915 goto out; 1916 1917 grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1); 1918 1919 err = -EHOSTUNREACH; 1920 if (!grt) 1921 goto out; 1922 if (dev) { 1923 if (dev != grt->dst.dev) { 1924 ip6_rt_put(grt); 1925 goto out; 1926 } 1927 } else { 1928 dev = grt->dst.dev; 1929 idev = grt->rt6i_idev; 1930 dev_hold(dev); 1931 in6_dev_hold(grt->rt6i_idev); 1932 } 1933 if (!(grt->rt6i_flags & RTF_GATEWAY)) 1934 err = 0; 1935 ip6_rt_put(grt); 1936 1937 if (err) 1938 goto out; 1939 } 1940 err = -EINVAL; 1941 if (!dev || (dev->flags & IFF_LOOPBACK)) 1942 goto out; 1943 } 1944 1945 err = -ENODEV; 1946 if (!dev) 1947 goto out; 1948 1949 if (!ipv6_addr_any(&cfg->fc_prefsrc)) { 1950 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) { 1951 err = -EINVAL; 1952 goto out; 1953 } 1954 rt->rt6i_prefsrc.addr = cfg->fc_prefsrc; 1955 rt->rt6i_prefsrc.plen = 128; 1956 } else 1957 rt->rt6i_prefsrc.plen = 0; 1958 1959 rt->rt6i_flags = cfg->fc_flags; 1960 1961 install_route: 1962 rt->dst.dev = dev; 1963 rt->rt6i_idev = idev; 1964 rt->rt6i_table = table; 1965 1966 cfg->fc_nlinfo.nl_net = dev_net(dev); 1967 1968 return rt; 1969 out: 1970 if (dev) 1971 dev_put(dev); 1972 if (idev) 1973 in6_dev_put(idev); 1974 if (rt) 1975 dst_free(&rt->dst); 1976 1977 return ERR_PTR(err); 1978 } 1979 1980 int ip6_route_add(struct fib6_config *cfg) 1981 { 1982 struct mx6_config mxc = { .mx = NULL, }; 1983 struct rt6_info *rt; 1984 int err; 1985 1986 rt = ip6_route_info_create(cfg); 1987 if (IS_ERR(rt)) { 1988 err = PTR_ERR(rt); 1989 rt = NULL; 1990 goto out; 1991 } 1992 1993 err = ip6_convert_metrics(&mxc, cfg); 1994 if (err) 1995 goto out; 1996 1997 err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, &mxc); 1998 1999 kfree(mxc.mx); 2000 2001 return err; 2002 out: 2003 if (rt) 2004 dst_free(&rt->dst); 2005 2006 return err; 2007 } 2008 2009 static int __ip6_del_rt(struct rt6_info *rt, struct nl_info *info) 2010 { 2011 int err; 2012 struct fib6_table *table; 2013 struct net *net = dev_net(rt->dst.dev); 2014 2015 if (rt == net->ipv6.ip6_null_entry || 2016 rt->dst.flags & DST_NOCACHE) { 2017 err = -ENOENT; 2018 goto out; 2019 } 2020 2021 table = rt->rt6i_table; 2022 write_lock_bh(&table->tb6_lock); 2023 err = fib6_del(rt, info); 2024 write_unlock_bh(&table->tb6_lock); 2025 2026 out: 2027 ip6_rt_put(rt); 2028 return err; 2029 } 2030 2031 int ip6_del_rt(struct rt6_info *rt) 2032 { 2033 struct nl_info info = { 2034 .nl_net = dev_net(rt->dst.dev), 2035 }; 2036 return __ip6_del_rt(rt, &info); 2037 } 2038 2039 static int ip6_route_del(struct fib6_config *cfg) 2040 { 2041 struct fib6_table *table; 2042 struct fib6_node *fn; 2043 struct rt6_info *rt; 2044 int err = -ESRCH; 2045 2046 table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table); 2047 if (!table) 2048 return err; 2049 2050 read_lock_bh(&table->tb6_lock); 2051 2052 fn = fib6_locate(&table->tb6_root, 2053 &cfg->fc_dst, cfg->fc_dst_len, 2054 &cfg->fc_src, cfg->fc_src_len); 2055 2056 if (fn) { 2057 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { 2058 if ((rt->rt6i_flags & RTF_CACHE) && 2059 !(cfg->fc_flags & RTF_CACHE)) 2060 continue; 2061 if (cfg->fc_ifindex && 2062 (!rt->dst.dev || 2063 rt->dst.dev->ifindex != cfg->fc_ifindex)) 2064 continue; 2065 if (cfg->fc_flags & RTF_GATEWAY && 2066 !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway)) 2067 continue; 2068 if (cfg->fc_metric && cfg->fc_metric != rt->rt6i_metric) 2069 continue; 2070 dst_hold(&rt->dst); 2071 read_unlock_bh(&table->tb6_lock); 2072 2073 return __ip6_del_rt(rt, &cfg->fc_nlinfo); 2074 } 2075 } 2076 read_unlock_bh(&table->tb6_lock); 2077 2078 return err; 2079 } 2080 2081 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 2082 { 2083 struct netevent_redirect netevent; 2084 struct rt6_info *rt, *nrt = NULL; 2085 struct ndisc_options ndopts; 2086 struct inet6_dev *in6_dev; 2087 struct neighbour *neigh; 2088 struct rd_msg *msg; 2089 int optlen, on_link; 2090 u8 *lladdr; 2091 2092 optlen = skb_tail_pointer(skb) - skb_transport_header(skb); 2093 optlen -= sizeof(*msg); 2094 2095 if (optlen < 0) { 2096 net_dbg_ratelimited("rt6_do_redirect: packet too short\n"); 2097 return; 2098 } 2099 2100 msg = (struct rd_msg *)icmp6_hdr(skb); 2101 2102 if (ipv6_addr_is_multicast(&msg->dest)) { 2103 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n"); 2104 return; 2105 } 2106 2107 on_link = 0; 2108 if (ipv6_addr_equal(&msg->dest, &msg->target)) { 2109 on_link = 1; 2110 } else if (ipv6_addr_type(&msg->target) != 2111 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 2112 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n"); 2113 return; 2114 } 2115 2116 in6_dev = __in6_dev_get(skb->dev); 2117 if (!in6_dev) 2118 return; 2119 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) 2120 return; 2121 2122 /* RFC2461 8.1: 2123 * The IP source address of the Redirect MUST be the same as the current 2124 * first-hop router for the specified ICMP Destination Address. 2125 */ 2126 2127 if (!ndisc_parse_options(msg->opt, optlen, &ndopts)) { 2128 net_dbg_ratelimited("rt6_redirect: invalid ND options\n"); 2129 return; 2130 } 2131 2132 lladdr = NULL; 2133 if (ndopts.nd_opts_tgt_lladdr) { 2134 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, 2135 skb->dev); 2136 if (!lladdr) { 2137 net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n"); 2138 return; 2139 } 2140 } 2141 2142 rt = (struct rt6_info *) dst; 2143 if (rt->rt6i_flags & RTF_REJECT) { 2144 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n"); 2145 return; 2146 } 2147 2148 /* Redirect received -> path was valid. 2149 * Look, redirects are sent only in response to data packets, 2150 * so that this nexthop apparently is reachable. --ANK 2151 */ 2152 dst_confirm(&rt->dst); 2153 2154 neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1); 2155 if (!neigh) 2156 return; 2157 2158 /* 2159 * We have finally decided to accept it. 2160 */ 2161 2162 neigh_update(neigh, lladdr, NUD_STALE, 2163 NEIGH_UPDATE_F_WEAK_OVERRIDE| 2164 NEIGH_UPDATE_F_OVERRIDE| 2165 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 2166 NEIGH_UPDATE_F_ISROUTER)) 2167 ); 2168 2169 nrt = ip6_rt_cache_alloc(rt, &msg->dest, NULL); 2170 if (!nrt) 2171 goto out; 2172 2173 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; 2174 if (on_link) 2175 nrt->rt6i_flags &= ~RTF_GATEWAY; 2176 2177 nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key; 2178 2179 if (ip6_ins_rt(nrt)) 2180 goto out; 2181 2182 netevent.old = &rt->dst; 2183 netevent.new = &nrt->dst; 2184 netevent.daddr = &msg->dest; 2185 netevent.neigh = neigh; 2186 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent); 2187 2188 if (rt->rt6i_flags & RTF_CACHE) { 2189 rt = (struct rt6_info *) dst_clone(&rt->dst); 2190 ip6_del_rt(rt); 2191 } 2192 2193 out: 2194 neigh_release(neigh); 2195 } 2196 2197 /* 2198 * Misc support functions 2199 */ 2200 2201 static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from) 2202 { 2203 BUG_ON(from->dst.from); 2204 2205 rt->rt6i_flags &= ~RTF_EXPIRES; 2206 dst_hold(&from->dst); 2207 rt->dst.from = &from->dst; 2208 dst_init_metrics(&rt->dst, dst_metrics_ptr(&from->dst), true); 2209 } 2210 2211 static void ip6_rt_copy_init(struct rt6_info *rt, struct rt6_info *ort) 2212 { 2213 rt->dst.input = ort->dst.input; 2214 rt->dst.output = ort->dst.output; 2215 rt->rt6i_dst = ort->rt6i_dst; 2216 rt->dst.error = ort->dst.error; 2217 rt->rt6i_idev = ort->rt6i_idev; 2218 if (rt->rt6i_idev) 2219 in6_dev_hold(rt->rt6i_idev); 2220 rt->dst.lastuse = jiffies; 2221 rt->rt6i_gateway = ort->rt6i_gateway; 2222 rt->rt6i_flags = ort->rt6i_flags; 2223 rt6_set_from(rt, ort); 2224 rt->rt6i_metric = ort->rt6i_metric; 2225 #ifdef CONFIG_IPV6_SUBTREES 2226 rt->rt6i_src = ort->rt6i_src; 2227 #endif 2228 rt->rt6i_prefsrc = ort->rt6i_prefsrc; 2229 rt->rt6i_table = ort->rt6i_table; 2230 rt->dst.lwtstate = lwtstate_get(ort->dst.lwtstate); 2231 } 2232 2233 #ifdef CONFIG_IPV6_ROUTE_INFO 2234 static struct rt6_info *rt6_get_route_info(struct net *net, 2235 const struct in6_addr *prefix, int prefixlen, 2236 const struct in6_addr *gwaddr, int ifindex) 2237 { 2238 struct fib6_node *fn; 2239 struct rt6_info *rt = NULL; 2240 struct fib6_table *table; 2241 2242 table = fib6_get_table(net, RT6_TABLE_INFO); 2243 if (!table) 2244 return NULL; 2245 2246 read_lock_bh(&table->tb6_lock); 2247 fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0); 2248 if (!fn) 2249 goto out; 2250 2251 for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { 2252 if (rt->dst.dev->ifindex != ifindex) 2253 continue; 2254 if ((rt->rt6i_flags & (RTF_ROUTEINFO|RTF_GATEWAY)) != (RTF_ROUTEINFO|RTF_GATEWAY)) 2255 continue; 2256 if (!ipv6_addr_equal(&rt->rt6i_gateway, gwaddr)) 2257 continue; 2258 dst_hold(&rt->dst); 2259 break; 2260 } 2261 out: 2262 read_unlock_bh(&table->tb6_lock); 2263 return rt; 2264 } 2265 2266 static struct rt6_info *rt6_add_route_info(struct net *net, 2267 const struct in6_addr *prefix, int prefixlen, 2268 const struct in6_addr *gwaddr, int ifindex, 2269 unsigned int pref) 2270 { 2271 struct fib6_config cfg = { 2272 .fc_metric = IP6_RT_PRIO_USER, 2273 .fc_ifindex = ifindex, 2274 .fc_dst_len = prefixlen, 2275 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | 2276 RTF_UP | RTF_PREF(pref), 2277 .fc_nlinfo.portid = 0, 2278 .fc_nlinfo.nlh = NULL, 2279 .fc_nlinfo.nl_net = net, 2280 }; 2281 2282 cfg.fc_table = l3mdev_fib_table_by_index(net, ifindex) ? : RT6_TABLE_INFO; 2283 cfg.fc_dst = *prefix; 2284 cfg.fc_gateway = *gwaddr; 2285 2286 /* We should treat it as a default route if prefix length is 0. */ 2287 if (!prefixlen) 2288 cfg.fc_flags |= RTF_DEFAULT; 2289 2290 ip6_route_add(&cfg); 2291 2292 return rt6_get_route_info(net, prefix, prefixlen, gwaddr, ifindex); 2293 } 2294 #endif 2295 2296 struct rt6_info *rt6_get_dflt_router(const struct in6_addr *addr, struct net_device *dev) 2297 { 2298 struct rt6_info *rt; 2299 struct fib6_table *table; 2300 2301 table = fib6_get_table(dev_net(dev), RT6_TABLE_DFLT); 2302 if (!table) 2303 return NULL; 2304 2305 read_lock_bh(&table->tb6_lock); 2306 for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) { 2307 if (dev == rt->dst.dev && 2308 ((rt->rt6i_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && 2309 ipv6_addr_equal(&rt->rt6i_gateway, addr)) 2310 break; 2311 } 2312 if (rt) 2313 dst_hold(&rt->dst); 2314 read_unlock_bh(&table->tb6_lock); 2315 return rt; 2316 } 2317 2318 struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr, 2319 struct net_device *dev, 2320 unsigned int pref) 2321 { 2322 struct fib6_config cfg = { 2323 .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT, 2324 .fc_metric = IP6_RT_PRIO_USER, 2325 .fc_ifindex = dev->ifindex, 2326 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | 2327 RTF_UP | RTF_EXPIRES | RTF_PREF(pref), 2328 .fc_nlinfo.portid = 0, 2329 .fc_nlinfo.nlh = NULL, 2330 .fc_nlinfo.nl_net = dev_net(dev), 2331 }; 2332 2333 cfg.fc_gateway = *gwaddr; 2334 2335 ip6_route_add(&cfg); 2336 2337 return rt6_get_dflt_router(gwaddr, dev); 2338 } 2339 2340 void rt6_purge_dflt_routers(struct net *net) 2341 { 2342 struct rt6_info *rt; 2343 struct fib6_table *table; 2344 2345 /* NOTE: Keep consistent with rt6_get_dflt_router */ 2346 table = fib6_get_table(net, RT6_TABLE_DFLT); 2347 if (!table) 2348 return; 2349 2350 restart: 2351 read_lock_bh(&table->tb6_lock); 2352 for (rt = table->tb6_root.leaf; rt; rt = rt->dst.rt6_next) { 2353 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF) && 2354 (!rt->rt6i_idev || rt->rt6i_idev->cnf.accept_ra != 2)) { 2355 dst_hold(&rt->dst); 2356 read_unlock_bh(&table->tb6_lock); 2357 ip6_del_rt(rt); 2358 goto restart; 2359 } 2360 } 2361 read_unlock_bh(&table->tb6_lock); 2362 } 2363 2364 static void rtmsg_to_fib6_config(struct net *net, 2365 struct in6_rtmsg *rtmsg, 2366 struct fib6_config *cfg) 2367 { 2368 memset(cfg, 0, sizeof(*cfg)); 2369 2370 cfg->fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ? 2371 : RT6_TABLE_MAIN; 2372 cfg->fc_ifindex = rtmsg->rtmsg_ifindex; 2373 cfg->fc_metric = rtmsg->rtmsg_metric; 2374 cfg->fc_expires = rtmsg->rtmsg_info; 2375 cfg->fc_dst_len = rtmsg->rtmsg_dst_len; 2376 cfg->fc_src_len = rtmsg->rtmsg_src_len; 2377 cfg->fc_flags = rtmsg->rtmsg_flags; 2378 2379 cfg->fc_nlinfo.nl_net = net; 2380 2381 cfg->fc_dst = rtmsg->rtmsg_dst; 2382 cfg->fc_src = rtmsg->rtmsg_src; 2383 cfg->fc_gateway = rtmsg->rtmsg_gateway; 2384 } 2385 2386 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg) 2387 { 2388 struct fib6_config cfg; 2389 struct in6_rtmsg rtmsg; 2390 int err; 2391 2392 switch (cmd) { 2393 case SIOCADDRT: /* Add a route */ 2394 case SIOCDELRT: /* Delete a route */ 2395 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 2396 return -EPERM; 2397 err = copy_from_user(&rtmsg, arg, 2398 sizeof(struct in6_rtmsg)); 2399 if (err) 2400 return -EFAULT; 2401 2402 rtmsg_to_fib6_config(net, &rtmsg, &cfg); 2403 2404 rtnl_lock(); 2405 switch (cmd) { 2406 case SIOCADDRT: 2407 err = ip6_route_add(&cfg); 2408 break; 2409 case SIOCDELRT: 2410 err = ip6_route_del(&cfg); 2411 break; 2412 default: 2413 err = -EINVAL; 2414 } 2415 rtnl_unlock(); 2416 2417 return err; 2418 } 2419 2420 return -EINVAL; 2421 } 2422 2423 /* 2424 * Drop the packet on the floor 2425 */ 2426 2427 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes) 2428 { 2429 int type; 2430 struct dst_entry *dst = skb_dst(skb); 2431 switch (ipstats_mib_noroutes) { 2432 case IPSTATS_MIB_INNOROUTES: 2433 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr); 2434 if (type == IPV6_ADDR_ANY) { 2435 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst), 2436 IPSTATS_MIB_INADDRERRORS); 2437 break; 2438 } 2439 /* FALLTHROUGH */ 2440 case IPSTATS_MIB_OUTNOROUTES: 2441 IP6_INC_STATS(dev_net(dst->dev), ip6_dst_idev(dst), 2442 ipstats_mib_noroutes); 2443 break; 2444 } 2445 icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0); 2446 kfree_skb(skb); 2447 return 0; 2448 } 2449 2450 static int ip6_pkt_discard(struct sk_buff *skb) 2451 { 2452 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES); 2453 } 2454 2455 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb) 2456 { 2457 skb->dev = skb_dst(skb)->dev; 2458 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES); 2459 } 2460 2461 static int ip6_pkt_prohibit(struct sk_buff *skb) 2462 { 2463 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES); 2464 } 2465 2466 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb) 2467 { 2468 skb->dev = skb_dst(skb)->dev; 2469 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES); 2470 } 2471 2472 /* 2473 * Allocate a dst for local (unicast / anycast) address. 2474 */ 2475 2476 struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev, 2477 const struct in6_addr *addr, 2478 bool anycast) 2479 { 2480 u32 tb_id; 2481 struct net *net = dev_net(idev->dev); 2482 struct rt6_info *rt = ip6_dst_alloc(net, net->loopback_dev, 2483 DST_NOCOUNT); 2484 if (!rt) 2485 return ERR_PTR(-ENOMEM); 2486 2487 in6_dev_hold(idev); 2488 2489 rt->dst.flags |= DST_HOST; 2490 rt->dst.input = ip6_input; 2491 rt->dst.output = ip6_output; 2492 rt->rt6i_idev = idev; 2493 2494 rt->rt6i_flags = RTF_UP | RTF_NONEXTHOP; 2495 if (anycast) 2496 rt->rt6i_flags |= RTF_ANYCAST; 2497 else 2498 rt->rt6i_flags |= RTF_LOCAL; 2499 2500 rt->rt6i_gateway = *addr; 2501 rt->rt6i_dst.addr = *addr; 2502 rt->rt6i_dst.plen = 128; 2503 tb_id = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL; 2504 rt->rt6i_table = fib6_get_table(net, tb_id); 2505 rt->dst.flags |= DST_NOCACHE; 2506 2507 atomic_set(&rt->dst.__refcnt, 1); 2508 2509 return rt; 2510 } 2511 2512 int ip6_route_get_saddr(struct net *net, 2513 struct rt6_info *rt, 2514 const struct in6_addr *daddr, 2515 unsigned int prefs, 2516 struct in6_addr *saddr) 2517 { 2518 struct inet6_dev *idev = 2519 rt ? ip6_dst_idev((struct dst_entry *)rt) : NULL; 2520 int err = 0; 2521 if (rt && rt->rt6i_prefsrc.plen) 2522 *saddr = rt->rt6i_prefsrc.addr; 2523 else 2524 err = ipv6_dev_get_saddr(net, idev ? idev->dev : NULL, 2525 daddr, prefs, saddr); 2526 return err; 2527 } 2528 2529 /* remove deleted ip from prefsrc entries */ 2530 struct arg_dev_net_ip { 2531 struct net_device *dev; 2532 struct net *net; 2533 struct in6_addr *addr; 2534 }; 2535 2536 static int fib6_remove_prefsrc(struct rt6_info *rt, void *arg) 2537 { 2538 struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev; 2539 struct net *net = ((struct arg_dev_net_ip *)arg)->net; 2540 struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr; 2541 2542 if (((void *)rt->dst.dev == dev || !dev) && 2543 rt != net->ipv6.ip6_null_entry && 2544 ipv6_addr_equal(addr, &rt->rt6i_prefsrc.addr)) { 2545 /* remove prefsrc entry */ 2546 rt->rt6i_prefsrc.plen = 0; 2547 } 2548 return 0; 2549 } 2550 2551 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp) 2552 { 2553 struct net *net = dev_net(ifp->idev->dev); 2554 struct arg_dev_net_ip adni = { 2555 .dev = ifp->idev->dev, 2556 .net = net, 2557 .addr = &ifp->addr, 2558 }; 2559 fib6_clean_all(net, fib6_remove_prefsrc, &adni); 2560 } 2561 2562 #define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT | RTF_GATEWAY) 2563 #define RTF_CACHE_GATEWAY (RTF_GATEWAY | RTF_CACHE) 2564 2565 /* Remove routers and update dst entries when gateway turn into host. */ 2566 static int fib6_clean_tohost(struct rt6_info *rt, void *arg) 2567 { 2568 struct in6_addr *gateway = (struct in6_addr *)arg; 2569 2570 if ((((rt->rt6i_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) || 2571 ((rt->rt6i_flags & RTF_CACHE_GATEWAY) == RTF_CACHE_GATEWAY)) && 2572 ipv6_addr_equal(gateway, &rt->rt6i_gateway)) { 2573 return -1; 2574 } 2575 return 0; 2576 } 2577 2578 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway) 2579 { 2580 fib6_clean_all(net, fib6_clean_tohost, gateway); 2581 } 2582 2583 struct arg_dev_net { 2584 struct net_device *dev; 2585 struct net *net; 2586 }; 2587 2588 static int fib6_ifdown(struct rt6_info *rt, void *arg) 2589 { 2590 const struct arg_dev_net *adn = arg; 2591 const struct net_device *dev = adn->dev; 2592 2593 if ((rt->dst.dev == dev || !dev) && 2594 rt != adn->net->ipv6.ip6_null_entry) 2595 return -1; 2596 2597 return 0; 2598 } 2599 2600 void rt6_ifdown(struct net *net, struct net_device *dev) 2601 { 2602 struct arg_dev_net adn = { 2603 .dev = dev, 2604 .net = net, 2605 }; 2606 2607 fib6_clean_all(net, fib6_ifdown, &adn); 2608 icmp6_clean_all(fib6_ifdown, &adn); 2609 if (dev) 2610 rt6_uncached_list_flush_dev(net, dev); 2611 } 2612 2613 struct rt6_mtu_change_arg { 2614 struct net_device *dev; 2615 unsigned int mtu; 2616 }; 2617 2618 static int rt6_mtu_change_route(struct rt6_info *rt, void *p_arg) 2619 { 2620 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; 2621 struct inet6_dev *idev; 2622 2623 /* In IPv6 pmtu discovery is not optional, 2624 so that RTAX_MTU lock cannot disable it. 2625 We still use this lock to block changes 2626 caused by addrconf/ndisc. 2627 */ 2628 2629 idev = __in6_dev_get(arg->dev); 2630 if (!idev) 2631 return 0; 2632 2633 /* For administrative MTU increase, there is no way to discover 2634 IPv6 PMTU increase, so PMTU increase should be updated here. 2635 Since RFC 1981 doesn't include administrative MTU increase 2636 update PMTU increase is a MUST. (i.e. jumbo frame) 2637 */ 2638 /* 2639 If new MTU is less than route PMTU, this new MTU will be the 2640 lowest MTU in the path, update the route PMTU to reflect PMTU 2641 decreases; if new MTU is greater than route PMTU, and the 2642 old MTU is the lowest MTU in the path, update the route PMTU 2643 to reflect the increase. In this case if the other nodes' MTU 2644 also have the lowest MTU, TOO BIG MESSAGE will be lead to 2645 PMTU discouvery. 2646 */ 2647 if (rt->dst.dev == arg->dev && 2648 !dst_metric_locked(&rt->dst, RTAX_MTU)) { 2649 if (rt->rt6i_flags & RTF_CACHE) { 2650 /* For RTF_CACHE with rt6i_pmtu == 0 2651 * (i.e. a redirected route), 2652 * the metrics of its rt->dst.from has already 2653 * been updated. 2654 */ 2655 if (rt->rt6i_pmtu && rt->rt6i_pmtu > arg->mtu) 2656 rt->rt6i_pmtu = arg->mtu; 2657 } else if (dst_mtu(&rt->dst) >= arg->mtu || 2658 (dst_mtu(&rt->dst) < arg->mtu && 2659 dst_mtu(&rt->dst) == idev->cnf.mtu6)) { 2660 dst_metric_set(&rt->dst, RTAX_MTU, arg->mtu); 2661 } 2662 } 2663 return 0; 2664 } 2665 2666 void rt6_mtu_change(struct net_device *dev, unsigned int mtu) 2667 { 2668 struct rt6_mtu_change_arg arg = { 2669 .dev = dev, 2670 .mtu = mtu, 2671 }; 2672 2673 fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg); 2674 } 2675 2676 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = { 2677 [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) }, 2678 [RTA_OIF] = { .type = NLA_U32 }, 2679 [RTA_IIF] = { .type = NLA_U32 }, 2680 [RTA_PRIORITY] = { .type = NLA_U32 }, 2681 [RTA_METRICS] = { .type = NLA_NESTED }, 2682 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 2683 [RTA_PREF] = { .type = NLA_U8 }, 2684 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 2685 [RTA_ENCAP] = { .type = NLA_NESTED }, 2686 }; 2687 2688 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 2689 struct fib6_config *cfg) 2690 { 2691 struct rtmsg *rtm; 2692 struct nlattr *tb[RTA_MAX+1]; 2693 unsigned int pref; 2694 int err; 2695 2696 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy); 2697 if (err < 0) 2698 goto errout; 2699 2700 err = -EINVAL; 2701 rtm = nlmsg_data(nlh); 2702 memset(cfg, 0, sizeof(*cfg)); 2703 2704 cfg->fc_table = rtm->rtm_table; 2705 cfg->fc_dst_len = rtm->rtm_dst_len; 2706 cfg->fc_src_len = rtm->rtm_src_len; 2707 cfg->fc_flags = RTF_UP; 2708 cfg->fc_protocol = rtm->rtm_protocol; 2709 cfg->fc_type = rtm->rtm_type; 2710 2711 if (rtm->rtm_type == RTN_UNREACHABLE || 2712 rtm->rtm_type == RTN_BLACKHOLE || 2713 rtm->rtm_type == RTN_PROHIBIT || 2714 rtm->rtm_type == RTN_THROW) 2715 cfg->fc_flags |= RTF_REJECT; 2716 2717 if (rtm->rtm_type == RTN_LOCAL) 2718 cfg->fc_flags |= RTF_LOCAL; 2719 2720 if (rtm->rtm_flags & RTM_F_CLONED) 2721 cfg->fc_flags |= RTF_CACHE; 2722 2723 cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; 2724 cfg->fc_nlinfo.nlh = nlh; 2725 cfg->fc_nlinfo.nl_net = sock_net(skb->sk); 2726 2727 if (tb[RTA_GATEWAY]) { 2728 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]); 2729 cfg->fc_flags |= RTF_GATEWAY; 2730 } 2731 2732 if (tb[RTA_DST]) { 2733 int plen = (rtm->rtm_dst_len + 7) >> 3; 2734 2735 if (nla_len(tb[RTA_DST]) < plen) 2736 goto errout; 2737 2738 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen); 2739 } 2740 2741 if (tb[RTA_SRC]) { 2742 int plen = (rtm->rtm_src_len + 7) >> 3; 2743 2744 if (nla_len(tb[RTA_SRC]) < plen) 2745 goto errout; 2746 2747 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen); 2748 } 2749 2750 if (tb[RTA_PREFSRC]) 2751 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]); 2752 2753 if (tb[RTA_OIF]) 2754 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]); 2755 2756 if (tb[RTA_PRIORITY]) 2757 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]); 2758 2759 if (tb[RTA_METRICS]) { 2760 cfg->fc_mx = nla_data(tb[RTA_METRICS]); 2761 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]); 2762 } 2763 2764 if (tb[RTA_TABLE]) 2765 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]); 2766 2767 if (tb[RTA_MULTIPATH]) { 2768 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]); 2769 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]); 2770 } 2771 2772 if (tb[RTA_PREF]) { 2773 pref = nla_get_u8(tb[RTA_PREF]); 2774 if (pref != ICMPV6_ROUTER_PREF_LOW && 2775 pref != ICMPV6_ROUTER_PREF_HIGH) 2776 pref = ICMPV6_ROUTER_PREF_MEDIUM; 2777 cfg->fc_flags |= RTF_PREF(pref); 2778 } 2779 2780 if (tb[RTA_ENCAP]) 2781 cfg->fc_encap = tb[RTA_ENCAP]; 2782 2783 if (tb[RTA_ENCAP_TYPE]) 2784 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]); 2785 2786 err = 0; 2787 errout: 2788 return err; 2789 } 2790 2791 struct rt6_nh { 2792 struct rt6_info *rt6_info; 2793 struct fib6_config r_cfg; 2794 struct mx6_config mxc; 2795 struct list_head next; 2796 }; 2797 2798 static void ip6_print_replace_route_err(struct list_head *rt6_nh_list) 2799 { 2800 struct rt6_nh *nh; 2801 2802 list_for_each_entry(nh, rt6_nh_list, next) { 2803 pr_warn("IPV6: multipath route replace failed (check consistency of installed routes): %pI6 nexthop %pI6 ifi %d\n", 2804 &nh->r_cfg.fc_dst, &nh->r_cfg.fc_gateway, 2805 nh->r_cfg.fc_ifindex); 2806 } 2807 } 2808 2809 static int ip6_route_info_append(struct list_head *rt6_nh_list, 2810 struct rt6_info *rt, struct fib6_config *r_cfg) 2811 { 2812 struct rt6_nh *nh; 2813 struct rt6_info *rtnh; 2814 int err = -EEXIST; 2815 2816 list_for_each_entry(nh, rt6_nh_list, next) { 2817 /* check if rt6_info already exists */ 2818 rtnh = nh->rt6_info; 2819 2820 if (rtnh->dst.dev == rt->dst.dev && 2821 rtnh->rt6i_idev == rt->rt6i_idev && 2822 ipv6_addr_equal(&rtnh->rt6i_gateway, 2823 &rt->rt6i_gateway)) 2824 return err; 2825 } 2826 2827 nh = kzalloc(sizeof(*nh), GFP_KERNEL); 2828 if (!nh) 2829 return -ENOMEM; 2830 nh->rt6_info = rt; 2831 err = ip6_convert_metrics(&nh->mxc, r_cfg); 2832 if (err) { 2833 kfree(nh); 2834 return err; 2835 } 2836 memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg)); 2837 list_add_tail(&nh->next, rt6_nh_list); 2838 2839 return 0; 2840 } 2841 2842 static int ip6_route_multipath_add(struct fib6_config *cfg) 2843 { 2844 struct fib6_config r_cfg; 2845 struct rtnexthop *rtnh; 2846 struct rt6_info *rt; 2847 struct rt6_nh *err_nh; 2848 struct rt6_nh *nh, *nh_safe; 2849 int remaining; 2850 int attrlen; 2851 int err = 1; 2852 int nhn = 0; 2853 int replace = (cfg->fc_nlinfo.nlh && 2854 (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE)); 2855 LIST_HEAD(rt6_nh_list); 2856 2857 remaining = cfg->fc_mp_len; 2858 rtnh = (struct rtnexthop *)cfg->fc_mp; 2859 2860 /* Parse a Multipath Entry and build a list (rt6_nh_list) of 2861 * rt6_info structs per nexthop 2862 */ 2863 while (rtnh_ok(rtnh, remaining)) { 2864 memcpy(&r_cfg, cfg, sizeof(*cfg)); 2865 if (rtnh->rtnh_ifindex) 2866 r_cfg.fc_ifindex = rtnh->rtnh_ifindex; 2867 2868 attrlen = rtnh_attrlen(rtnh); 2869 if (attrlen > 0) { 2870 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 2871 2872 nla = nla_find(attrs, attrlen, RTA_GATEWAY); 2873 if (nla) { 2874 r_cfg.fc_gateway = nla_get_in6_addr(nla); 2875 r_cfg.fc_flags |= RTF_GATEWAY; 2876 } 2877 r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); 2878 nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); 2879 if (nla) 2880 r_cfg.fc_encap_type = nla_get_u16(nla); 2881 } 2882 2883 rt = ip6_route_info_create(&r_cfg); 2884 if (IS_ERR(rt)) { 2885 err = PTR_ERR(rt); 2886 rt = NULL; 2887 goto cleanup; 2888 } 2889 2890 err = ip6_route_info_append(&rt6_nh_list, rt, &r_cfg); 2891 if (err) { 2892 dst_free(&rt->dst); 2893 goto cleanup; 2894 } 2895 2896 rtnh = rtnh_next(rtnh, &remaining); 2897 } 2898 2899 err_nh = NULL; 2900 list_for_each_entry(nh, &rt6_nh_list, next) { 2901 err = __ip6_ins_rt(nh->rt6_info, &cfg->fc_nlinfo, &nh->mxc); 2902 /* nh->rt6_info is used or freed at this point, reset to NULL*/ 2903 nh->rt6_info = NULL; 2904 if (err) { 2905 if (replace && nhn) 2906 ip6_print_replace_route_err(&rt6_nh_list); 2907 err_nh = nh; 2908 goto add_errout; 2909 } 2910 2911 /* Because each route is added like a single route we remove 2912 * these flags after the first nexthop: if there is a collision, 2913 * we have already failed to add the first nexthop: 2914 * fib6_add_rt2node() has rejected it; when replacing, old 2915 * nexthops have been replaced by first new, the rest should 2916 * be added to it. 2917 */ 2918 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL | 2919 NLM_F_REPLACE); 2920 nhn++; 2921 } 2922 2923 goto cleanup; 2924 2925 add_errout: 2926 /* Delete routes that were already added */ 2927 list_for_each_entry(nh, &rt6_nh_list, next) { 2928 if (err_nh == nh) 2929 break; 2930 ip6_route_del(&nh->r_cfg); 2931 } 2932 2933 cleanup: 2934 list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) { 2935 if (nh->rt6_info) 2936 dst_free(&nh->rt6_info->dst); 2937 kfree(nh->mxc.mx); 2938 list_del(&nh->next); 2939 kfree(nh); 2940 } 2941 2942 return err; 2943 } 2944 2945 static int ip6_route_multipath_del(struct fib6_config *cfg) 2946 { 2947 struct fib6_config r_cfg; 2948 struct rtnexthop *rtnh; 2949 int remaining; 2950 int attrlen; 2951 int err = 1, last_err = 0; 2952 2953 remaining = cfg->fc_mp_len; 2954 rtnh = (struct rtnexthop *)cfg->fc_mp; 2955 2956 /* Parse a Multipath Entry */ 2957 while (rtnh_ok(rtnh, remaining)) { 2958 memcpy(&r_cfg, cfg, sizeof(*cfg)); 2959 if (rtnh->rtnh_ifindex) 2960 r_cfg.fc_ifindex = rtnh->rtnh_ifindex; 2961 2962 attrlen = rtnh_attrlen(rtnh); 2963 if (attrlen > 0) { 2964 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 2965 2966 nla = nla_find(attrs, attrlen, RTA_GATEWAY); 2967 if (nla) { 2968 nla_memcpy(&r_cfg.fc_gateway, nla, 16); 2969 r_cfg.fc_flags |= RTF_GATEWAY; 2970 } 2971 } 2972 err = ip6_route_del(&r_cfg); 2973 if (err) 2974 last_err = err; 2975 2976 rtnh = rtnh_next(rtnh, &remaining); 2977 } 2978 2979 return last_err; 2980 } 2981 2982 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh) 2983 { 2984 struct fib6_config cfg; 2985 int err; 2986 2987 err = rtm_to_fib6_config(skb, nlh, &cfg); 2988 if (err < 0) 2989 return err; 2990 2991 if (cfg.fc_mp) 2992 return ip6_route_multipath_del(&cfg); 2993 else 2994 return ip6_route_del(&cfg); 2995 } 2996 2997 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh) 2998 { 2999 struct fib6_config cfg; 3000 int err; 3001 3002 err = rtm_to_fib6_config(skb, nlh, &cfg); 3003 if (err < 0) 3004 return err; 3005 3006 if (cfg.fc_mp) 3007 return ip6_route_multipath_add(&cfg); 3008 else 3009 return ip6_route_add(&cfg); 3010 } 3011 3012 static inline size_t rt6_nlmsg_size(struct rt6_info *rt) 3013 { 3014 return NLMSG_ALIGN(sizeof(struct rtmsg)) 3015 + nla_total_size(16) /* RTA_SRC */ 3016 + nla_total_size(16) /* RTA_DST */ 3017 + nla_total_size(16) /* RTA_GATEWAY */ 3018 + nla_total_size(16) /* RTA_PREFSRC */ 3019 + nla_total_size(4) /* RTA_TABLE */ 3020 + nla_total_size(4) /* RTA_IIF */ 3021 + nla_total_size(4) /* RTA_OIF */ 3022 + nla_total_size(4) /* RTA_PRIORITY */ 3023 + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */ 3024 + nla_total_size(sizeof(struct rta_cacheinfo)) 3025 + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */ 3026 + nla_total_size(1) /* RTA_PREF */ 3027 + lwtunnel_get_encap_size(rt->dst.lwtstate); 3028 } 3029 3030 static int rt6_fill_node(struct net *net, 3031 struct sk_buff *skb, struct rt6_info *rt, 3032 struct in6_addr *dst, struct in6_addr *src, 3033 int iif, int type, u32 portid, u32 seq, 3034 int prefix, int nowait, unsigned int flags) 3035 { 3036 u32 metrics[RTAX_MAX]; 3037 struct rtmsg *rtm; 3038 struct nlmsghdr *nlh; 3039 long expires; 3040 u32 table; 3041 3042 if (prefix) { /* user wants prefix routes only */ 3043 if (!(rt->rt6i_flags & RTF_PREFIX_RT)) { 3044 /* success since this is not a prefix route */ 3045 return 1; 3046 } 3047 } 3048 3049 nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags); 3050 if (!nlh) 3051 return -EMSGSIZE; 3052 3053 rtm = nlmsg_data(nlh); 3054 rtm->rtm_family = AF_INET6; 3055 rtm->rtm_dst_len = rt->rt6i_dst.plen; 3056 rtm->rtm_src_len = rt->rt6i_src.plen; 3057 rtm->rtm_tos = 0; 3058 if (rt->rt6i_table) 3059 table = rt->rt6i_table->tb6_id; 3060 else 3061 table = RT6_TABLE_UNSPEC; 3062 rtm->rtm_table = table; 3063 if (nla_put_u32(skb, RTA_TABLE, table)) 3064 goto nla_put_failure; 3065 if (rt->rt6i_flags & RTF_REJECT) { 3066 switch (rt->dst.error) { 3067 case -EINVAL: 3068 rtm->rtm_type = RTN_BLACKHOLE; 3069 break; 3070 case -EACCES: 3071 rtm->rtm_type = RTN_PROHIBIT; 3072 break; 3073 case -EAGAIN: 3074 rtm->rtm_type = RTN_THROW; 3075 break; 3076 default: 3077 rtm->rtm_type = RTN_UNREACHABLE; 3078 break; 3079 } 3080 } 3081 else if (rt->rt6i_flags & RTF_LOCAL) 3082 rtm->rtm_type = RTN_LOCAL; 3083 else if (rt->dst.dev && (rt->dst.dev->flags & IFF_LOOPBACK)) 3084 rtm->rtm_type = RTN_LOCAL; 3085 else 3086 rtm->rtm_type = RTN_UNICAST; 3087 rtm->rtm_flags = 0; 3088 if (!netif_carrier_ok(rt->dst.dev)) { 3089 rtm->rtm_flags |= RTNH_F_LINKDOWN; 3090 if (rt->rt6i_idev->cnf.ignore_routes_with_linkdown) 3091 rtm->rtm_flags |= RTNH_F_DEAD; 3092 } 3093 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 3094 rtm->rtm_protocol = rt->rt6i_protocol; 3095 if (rt->rt6i_flags & RTF_DYNAMIC) 3096 rtm->rtm_protocol = RTPROT_REDIRECT; 3097 else if (rt->rt6i_flags & RTF_ADDRCONF) { 3098 if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ROUTEINFO)) 3099 rtm->rtm_protocol = RTPROT_RA; 3100 else 3101 rtm->rtm_protocol = RTPROT_KERNEL; 3102 } 3103 3104 if (rt->rt6i_flags & RTF_CACHE) 3105 rtm->rtm_flags |= RTM_F_CLONED; 3106 3107 if (dst) { 3108 if (nla_put_in6_addr(skb, RTA_DST, dst)) 3109 goto nla_put_failure; 3110 rtm->rtm_dst_len = 128; 3111 } else if (rtm->rtm_dst_len) 3112 if (nla_put_in6_addr(skb, RTA_DST, &rt->rt6i_dst.addr)) 3113 goto nla_put_failure; 3114 #ifdef CONFIG_IPV6_SUBTREES 3115 if (src) { 3116 if (nla_put_in6_addr(skb, RTA_SRC, src)) 3117 goto nla_put_failure; 3118 rtm->rtm_src_len = 128; 3119 } else if (rtm->rtm_src_len && 3120 nla_put_in6_addr(skb, RTA_SRC, &rt->rt6i_src.addr)) 3121 goto nla_put_failure; 3122 #endif 3123 if (iif) { 3124 #ifdef CONFIG_IPV6_MROUTE 3125 if (ipv6_addr_is_multicast(&rt->rt6i_dst.addr)) { 3126 int err = ip6mr_get_route(net, skb, rtm, nowait); 3127 if (err <= 0) { 3128 if (!nowait) { 3129 if (err == 0) 3130 return 0; 3131 goto nla_put_failure; 3132 } else { 3133 if (err == -EMSGSIZE) 3134 goto nla_put_failure; 3135 } 3136 } 3137 } else 3138 #endif 3139 if (nla_put_u32(skb, RTA_IIF, iif)) 3140 goto nla_put_failure; 3141 } else if (dst) { 3142 struct in6_addr saddr_buf; 3143 if (ip6_route_get_saddr(net, rt, dst, 0, &saddr_buf) == 0 && 3144 nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) 3145 goto nla_put_failure; 3146 } 3147 3148 if (rt->rt6i_prefsrc.plen) { 3149 struct in6_addr saddr_buf; 3150 saddr_buf = rt->rt6i_prefsrc.addr; 3151 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) 3152 goto nla_put_failure; 3153 } 3154 3155 memcpy(metrics, dst_metrics_ptr(&rt->dst), sizeof(metrics)); 3156 if (rt->rt6i_pmtu) 3157 metrics[RTAX_MTU - 1] = rt->rt6i_pmtu; 3158 if (rtnetlink_put_metrics(skb, metrics) < 0) 3159 goto nla_put_failure; 3160 3161 if (rt->rt6i_flags & RTF_GATEWAY) { 3162 if (nla_put_in6_addr(skb, RTA_GATEWAY, &rt->rt6i_gateway) < 0) 3163 goto nla_put_failure; 3164 } 3165 3166 if (rt->dst.dev && 3167 nla_put_u32(skb, RTA_OIF, rt->dst.dev->ifindex)) 3168 goto nla_put_failure; 3169 if (nla_put_u32(skb, RTA_PRIORITY, rt->rt6i_metric)) 3170 goto nla_put_failure; 3171 3172 expires = (rt->rt6i_flags & RTF_EXPIRES) ? rt->dst.expires - jiffies : 0; 3173 3174 if (rtnl_put_cacheinfo(skb, &rt->dst, 0, expires, rt->dst.error) < 0) 3175 goto nla_put_failure; 3176 3177 if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt->rt6i_flags))) 3178 goto nla_put_failure; 3179 3180 lwtunnel_fill_encap(skb, rt->dst.lwtstate); 3181 3182 nlmsg_end(skb, nlh); 3183 return 0; 3184 3185 nla_put_failure: 3186 nlmsg_cancel(skb, nlh); 3187 return -EMSGSIZE; 3188 } 3189 3190 int rt6_dump_route(struct rt6_info *rt, void *p_arg) 3191 { 3192 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; 3193 int prefix; 3194 3195 if (nlmsg_len(arg->cb->nlh) >= sizeof(struct rtmsg)) { 3196 struct rtmsg *rtm = nlmsg_data(arg->cb->nlh); 3197 prefix = (rtm->rtm_flags & RTM_F_PREFIX) != 0; 3198 } else 3199 prefix = 0; 3200 3201 return rt6_fill_node(arg->net, 3202 arg->skb, rt, NULL, NULL, 0, RTM_NEWROUTE, 3203 NETLINK_CB(arg->cb->skb).portid, arg->cb->nlh->nlmsg_seq, 3204 prefix, 0, NLM_F_MULTI); 3205 } 3206 3207 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) 3208 { 3209 struct net *net = sock_net(in_skb->sk); 3210 struct nlattr *tb[RTA_MAX+1]; 3211 struct rt6_info *rt; 3212 struct sk_buff *skb; 3213 struct rtmsg *rtm; 3214 struct flowi6 fl6; 3215 int err, iif = 0, oif = 0; 3216 3217 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy); 3218 if (err < 0) 3219 goto errout; 3220 3221 err = -EINVAL; 3222 memset(&fl6, 0, sizeof(fl6)); 3223 3224 if (tb[RTA_SRC]) { 3225 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr)) 3226 goto errout; 3227 3228 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]); 3229 } 3230 3231 if (tb[RTA_DST]) { 3232 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr)) 3233 goto errout; 3234 3235 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]); 3236 } 3237 3238 if (tb[RTA_IIF]) 3239 iif = nla_get_u32(tb[RTA_IIF]); 3240 3241 if (tb[RTA_OIF]) 3242 oif = nla_get_u32(tb[RTA_OIF]); 3243 3244 if (tb[RTA_MARK]) 3245 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]); 3246 3247 if (iif) { 3248 struct net_device *dev; 3249 int flags = 0; 3250 3251 dev = __dev_get_by_index(net, iif); 3252 if (!dev) { 3253 err = -ENODEV; 3254 goto errout; 3255 } 3256 3257 fl6.flowi6_iif = iif; 3258 3259 if (!ipv6_addr_any(&fl6.saddr)) 3260 flags |= RT6_LOOKUP_F_HAS_SADDR; 3261 3262 rt = (struct rt6_info *)ip6_route_input_lookup(net, dev, &fl6, 3263 flags); 3264 } else { 3265 fl6.flowi6_oif = oif; 3266 3267 if (netif_index_is_l3_master(net, oif)) { 3268 fl6.flowi6_flags = FLOWI_FLAG_L3MDEV_SRC | 3269 FLOWI_FLAG_SKIP_NH_OIF; 3270 } 3271 3272 rt = (struct rt6_info *)ip6_route_output(net, NULL, &fl6); 3273 } 3274 3275 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 3276 if (!skb) { 3277 ip6_rt_put(rt); 3278 err = -ENOBUFS; 3279 goto errout; 3280 } 3281 3282 /* Reserve room for dummy headers, this skb can pass 3283 through good chunk of routing engine. 3284 */ 3285 skb_reset_mac_header(skb); 3286 skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr)); 3287 3288 skb_dst_set(skb, &rt->dst); 3289 3290 err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif, 3291 RTM_NEWROUTE, NETLINK_CB(in_skb).portid, 3292 nlh->nlmsg_seq, 0, 0, 0); 3293 if (err < 0) { 3294 kfree_skb(skb); 3295 goto errout; 3296 } 3297 3298 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 3299 errout: 3300 return err; 3301 } 3302 3303 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info, 3304 unsigned int nlm_flags) 3305 { 3306 struct sk_buff *skb; 3307 struct net *net = info->nl_net; 3308 u32 seq; 3309 int err; 3310 3311 err = -ENOBUFS; 3312 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 3313 3314 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); 3315 if (!skb) 3316 goto errout; 3317 3318 err = rt6_fill_node(net, skb, rt, NULL, NULL, 0, 3319 event, info->portid, seq, 0, 0, nlm_flags); 3320 if (err < 0) { 3321 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 3322 WARN_ON(err == -EMSGSIZE); 3323 kfree_skb(skb); 3324 goto errout; 3325 } 3326 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, 3327 info->nlh, gfp_any()); 3328 return; 3329 errout: 3330 if (err < 0) 3331 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 3332 } 3333 3334 static int ip6_route_dev_notify(struct notifier_block *this, 3335 unsigned long event, void *ptr) 3336 { 3337 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 3338 struct net *net = dev_net(dev); 3339 3340 if (event == NETDEV_REGISTER && (dev->flags & IFF_LOOPBACK)) { 3341 net->ipv6.ip6_null_entry->dst.dev = dev; 3342 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev); 3343 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 3344 net->ipv6.ip6_prohibit_entry->dst.dev = dev; 3345 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev); 3346 net->ipv6.ip6_blk_hole_entry->dst.dev = dev; 3347 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); 3348 #endif 3349 } 3350 3351 return NOTIFY_OK; 3352 } 3353 3354 /* 3355 * /proc 3356 */ 3357 3358 #ifdef CONFIG_PROC_FS 3359 3360 static const struct file_operations ipv6_route_proc_fops = { 3361 .owner = THIS_MODULE, 3362 .open = ipv6_route_open, 3363 .read = seq_read, 3364 .llseek = seq_lseek, 3365 .release = seq_release_net, 3366 }; 3367 3368 static int rt6_stats_seq_show(struct seq_file *seq, void *v) 3369 { 3370 struct net *net = (struct net *)seq->private; 3371 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", 3372 net->ipv6.rt6_stats->fib_nodes, 3373 net->ipv6.rt6_stats->fib_route_nodes, 3374 net->ipv6.rt6_stats->fib_rt_alloc, 3375 net->ipv6.rt6_stats->fib_rt_entries, 3376 net->ipv6.rt6_stats->fib_rt_cache, 3377 dst_entries_get_slow(&net->ipv6.ip6_dst_ops), 3378 net->ipv6.rt6_stats->fib_discarded_routes); 3379 3380 return 0; 3381 } 3382 3383 static int rt6_stats_seq_open(struct inode *inode, struct file *file) 3384 { 3385 return single_open_net(inode, file, rt6_stats_seq_show); 3386 } 3387 3388 static const struct file_operations rt6_stats_seq_fops = { 3389 .owner = THIS_MODULE, 3390 .open = rt6_stats_seq_open, 3391 .read = seq_read, 3392 .llseek = seq_lseek, 3393 .release = single_release_net, 3394 }; 3395 #endif /* CONFIG_PROC_FS */ 3396 3397 #ifdef CONFIG_SYSCTL 3398 3399 static 3400 int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write, 3401 void __user *buffer, size_t *lenp, loff_t *ppos) 3402 { 3403 struct net *net; 3404 int delay; 3405 if (!write) 3406 return -EINVAL; 3407 3408 net = (struct net *)ctl->extra1; 3409 delay = net->ipv6.sysctl.flush_delay; 3410 proc_dointvec(ctl, write, buffer, lenp, ppos); 3411 fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0); 3412 return 0; 3413 } 3414 3415 struct ctl_table ipv6_route_table_template[] = { 3416 { 3417 .procname = "flush", 3418 .data = &init_net.ipv6.sysctl.flush_delay, 3419 .maxlen = sizeof(int), 3420 .mode = 0200, 3421 .proc_handler = ipv6_sysctl_rtcache_flush 3422 }, 3423 { 3424 .procname = "gc_thresh", 3425 .data = &ip6_dst_ops_template.gc_thresh, 3426 .maxlen = sizeof(int), 3427 .mode = 0644, 3428 .proc_handler = proc_dointvec, 3429 }, 3430 { 3431 .procname = "max_size", 3432 .data = &init_net.ipv6.sysctl.ip6_rt_max_size, 3433 .maxlen = sizeof(int), 3434 .mode = 0644, 3435 .proc_handler = proc_dointvec, 3436 }, 3437 { 3438 .procname = "gc_min_interval", 3439 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 3440 .maxlen = sizeof(int), 3441 .mode = 0644, 3442 .proc_handler = proc_dointvec_jiffies, 3443 }, 3444 { 3445 .procname = "gc_timeout", 3446 .data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout, 3447 .maxlen = sizeof(int), 3448 .mode = 0644, 3449 .proc_handler = proc_dointvec_jiffies, 3450 }, 3451 { 3452 .procname = "gc_interval", 3453 .data = &init_net.ipv6.sysctl.ip6_rt_gc_interval, 3454 .maxlen = sizeof(int), 3455 .mode = 0644, 3456 .proc_handler = proc_dointvec_jiffies, 3457 }, 3458 { 3459 .procname = "gc_elasticity", 3460 .data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity, 3461 .maxlen = sizeof(int), 3462 .mode = 0644, 3463 .proc_handler = proc_dointvec, 3464 }, 3465 { 3466 .procname = "mtu_expires", 3467 .data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires, 3468 .maxlen = sizeof(int), 3469 .mode = 0644, 3470 .proc_handler = proc_dointvec_jiffies, 3471 }, 3472 { 3473 .procname = "min_adv_mss", 3474 .data = &init_net.ipv6.sysctl.ip6_rt_min_advmss, 3475 .maxlen = sizeof(int), 3476 .mode = 0644, 3477 .proc_handler = proc_dointvec, 3478 }, 3479 { 3480 .procname = "gc_min_interval_ms", 3481 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 3482 .maxlen = sizeof(int), 3483 .mode = 0644, 3484 .proc_handler = proc_dointvec_ms_jiffies, 3485 }, 3486 { } 3487 }; 3488 3489 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net) 3490 { 3491 struct ctl_table *table; 3492 3493 table = kmemdup(ipv6_route_table_template, 3494 sizeof(ipv6_route_table_template), 3495 GFP_KERNEL); 3496 3497 if (table) { 3498 table[0].data = &net->ipv6.sysctl.flush_delay; 3499 table[0].extra1 = net; 3500 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh; 3501 table[2].data = &net->ipv6.sysctl.ip6_rt_max_size; 3502 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 3503 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout; 3504 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval; 3505 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity; 3506 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires; 3507 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss; 3508 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 3509 3510 /* Don't export sysctls to unprivileged users */ 3511 if (net->user_ns != &init_user_ns) 3512 table[0].procname = NULL; 3513 } 3514 3515 return table; 3516 } 3517 #endif 3518 3519 static int __net_init ip6_route_net_init(struct net *net) 3520 { 3521 int ret = -ENOMEM; 3522 3523 memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template, 3524 sizeof(net->ipv6.ip6_dst_ops)); 3525 3526 if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0) 3527 goto out_ip6_dst_ops; 3528 3529 net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template, 3530 sizeof(*net->ipv6.ip6_null_entry), 3531 GFP_KERNEL); 3532 if (!net->ipv6.ip6_null_entry) 3533 goto out_ip6_dst_entries; 3534 net->ipv6.ip6_null_entry->dst.path = 3535 (struct dst_entry *)net->ipv6.ip6_null_entry; 3536 net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops; 3537 dst_init_metrics(&net->ipv6.ip6_null_entry->dst, 3538 ip6_template_metrics, true); 3539 3540 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 3541 net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template, 3542 sizeof(*net->ipv6.ip6_prohibit_entry), 3543 GFP_KERNEL); 3544 if (!net->ipv6.ip6_prohibit_entry) 3545 goto out_ip6_null_entry; 3546 net->ipv6.ip6_prohibit_entry->dst.path = 3547 (struct dst_entry *)net->ipv6.ip6_prohibit_entry; 3548 net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops; 3549 dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst, 3550 ip6_template_metrics, true); 3551 3552 net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template, 3553 sizeof(*net->ipv6.ip6_blk_hole_entry), 3554 GFP_KERNEL); 3555 if (!net->ipv6.ip6_blk_hole_entry) 3556 goto out_ip6_prohibit_entry; 3557 net->ipv6.ip6_blk_hole_entry->dst.path = 3558 (struct dst_entry *)net->ipv6.ip6_blk_hole_entry; 3559 net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops; 3560 dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst, 3561 ip6_template_metrics, true); 3562 #endif 3563 3564 net->ipv6.sysctl.flush_delay = 0; 3565 net->ipv6.sysctl.ip6_rt_max_size = 4096; 3566 net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2; 3567 net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ; 3568 net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ; 3569 net->ipv6.sysctl.ip6_rt_gc_elasticity = 9; 3570 net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ; 3571 net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; 3572 3573 net->ipv6.ip6_rt_gc_expire = 30*HZ; 3574 3575 ret = 0; 3576 out: 3577 return ret; 3578 3579 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 3580 out_ip6_prohibit_entry: 3581 kfree(net->ipv6.ip6_prohibit_entry); 3582 out_ip6_null_entry: 3583 kfree(net->ipv6.ip6_null_entry); 3584 #endif 3585 out_ip6_dst_entries: 3586 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 3587 out_ip6_dst_ops: 3588 goto out; 3589 } 3590 3591 static void __net_exit ip6_route_net_exit(struct net *net) 3592 { 3593 kfree(net->ipv6.ip6_null_entry); 3594 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 3595 kfree(net->ipv6.ip6_prohibit_entry); 3596 kfree(net->ipv6.ip6_blk_hole_entry); 3597 #endif 3598 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 3599 } 3600 3601 static int __net_init ip6_route_net_init_late(struct net *net) 3602 { 3603 #ifdef CONFIG_PROC_FS 3604 proc_create("ipv6_route", 0, net->proc_net, &ipv6_route_proc_fops); 3605 proc_create("rt6_stats", S_IRUGO, net->proc_net, &rt6_stats_seq_fops); 3606 #endif 3607 return 0; 3608 } 3609 3610 static void __net_exit ip6_route_net_exit_late(struct net *net) 3611 { 3612 #ifdef CONFIG_PROC_FS 3613 remove_proc_entry("ipv6_route", net->proc_net); 3614 remove_proc_entry("rt6_stats", net->proc_net); 3615 #endif 3616 } 3617 3618 static struct pernet_operations ip6_route_net_ops = { 3619 .init = ip6_route_net_init, 3620 .exit = ip6_route_net_exit, 3621 }; 3622 3623 static int __net_init ipv6_inetpeer_init(struct net *net) 3624 { 3625 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 3626 3627 if (!bp) 3628 return -ENOMEM; 3629 inet_peer_base_init(bp); 3630 net->ipv6.peers = bp; 3631 return 0; 3632 } 3633 3634 static void __net_exit ipv6_inetpeer_exit(struct net *net) 3635 { 3636 struct inet_peer_base *bp = net->ipv6.peers; 3637 3638 net->ipv6.peers = NULL; 3639 inetpeer_invalidate_tree(bp); 3640 kfree(bp); 3641 } 3642 3643 static struct pernet_operations ipv6_inetpeer_ops = { 3644 .init = ipv6_inetpeer_init, 3645 .exit = ipv6_inetpeer_exit, 3646 }; 3647 3648 static struct pernet_operations ip6_route_net_late_ops = { 3649 .init = ip6_route_net_init_late, 3650 .exit = ip6_route_net_exit_late, 3651 }; 3652 3653 static struct notifier_block ip6_route_dev_notifier = { 3654 .notifier_call = ip6_route_dev_notify, 3655 .priority = 0, 3656 }; 3657 3658 int __init ip6_route_init(void) 3659 { 3660 int ret; 3661 int cpu; 3662 3663 ret = -ENOMEM; 3664 ip6_dst_ops_template.kmem_cachep = 3665 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0, 3666 SLAB_HWCACHE_ALIGN, NULL); 3667 if (!ip6_dst_ops_template.kmem_cachep) 3668 goto out; 3669 3670 ret = dst_entries_init(&ip6_dst_blackhole_ops); 3671 if (ret) 3672 goto out_kmem_cache; 3673 3674 ret = register_pernet_subsys(&ipv6_inetpeer_ops); 3675 if (ret) 3676 goto out_dst_entries; 3677 3678 ret = register_pernet_subsys(&ip6_route_net_ops); 3679 if (ret) 3680 goto out_register_inetpeer; 3681 3682 ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep; 3683 3684 /* Registering of the loopback is done before this portion of code, 3685 * the loopback reference in rt6_info will not be taken, do it 3686 * manually for init_net */ 3687 init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev; 3688 init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 3689 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 3690 init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev; 3691 init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 3692 init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev; 3693 init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 3694 #endif 3695 ret = fib6_init(); 3696 if (ret) 3697 goto out_register_subsys; 3698 3699 ret = xfrm6_init(); 3700 if (ret) 3701 goto out_fib6_init; 3702 3703 ret = fib6_rules_init(); 3704 if (ret) 3705 goto xfrm6_init; 3706 3707 ret = register_pernet_subsys(&ip6_route_net_late_ops); 3708 if (ret) 3709 goto fib6_rules_init; 3710 3711 ret = -ENOBUFS; 3712 if (__rtnl_register(PF_INET6, RTM_NEWROUTE, inet6_rtm_newroute, NULL, NULL) || 3713 __rtnl_register(PF_INET6, RTM_DELROUTE, inet6_rtm_delroute, NULL, NULL) || 3714 __rtnl_register(PF_INET6, RTM_GETROUTE, inet6_rtm_getroute, NULL, NULL)) 3715 goto out_register_late_subsys; 3716 3717 ret = register_netdevice_notifier(&ip6_route_dev_notifier); 3718 if (ret) 3719 goto out_register_late_subsys; 3720 3721 for_each_possible_cpu(cpu) { 3722 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); 3723 3724 INIT_LIST_HEAD(&ul->head); 3725 spin_lock_init(&ul->lock); 3726 } 3727 3728 out: 3729 return ret; 3730 3731 out_register_late_subsys: 3732 unregister_pernet_subsys(&ip6_route_net_late_ops); 3733 fib6_rules_init: 3734 fib6_rules_cleanup(); 3735 xfrm6_init: 3736 xfrm6_fini(); 3737 out_fib6_init: 3738 fib6_gc_cleanup(); 3739 out_register_subsys: 3740 unregister_pernet_subsys(&ip6_route_net_ops); 3741 out_register_inetpeer: 3742 unregister_pernet_subsys(&ipv6_inetpeer_ops); 3743 out_dst_entries: 3744 dst_entries_destroy(&ip6_dst_blackhole_ops); 3745 out_kmem_cache: 3746 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 3747 goto out; 3748 } 3749 3750 void ip6_route_cleanup(void) 3751 { 3752 unregister_netdevice_notifier(&ip6_route_dev_notifier); 3753 unregister_pernet_subsys(&ip6_route_net_late_ops); 3754 fib6_rules_cleanup(); 3755 xfrm6_fini(); 3756 fib6_gc_cleanup(); 3757 unregister_pernet_subsys(&ipv6_inetpeer_ops); 3758 unregister_pernet_subsys(&ip6_route_net_ops); 3759 dst_entries_destroy(&ip6_dst_blackhole_ops); 3760 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 3761 } 3762