1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Linux INET6 implementation 4 * FIB front-end. 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 */ 9 10 /* Changes: 11 * 12 * YOSHIFUJI Hideaki @USAGI 13 * reworked default router selection. 14 * - respect outgoing interface 15 * - select from (probably) reachable routers (i.e. 16 * routers in REACHABLE, STALE, DELAY or PROBE states). 17 * - always select the same router if it is (probably) 18 * reachable. otherwise, round-robin the list. 19 * Ville Nuorvala 20 * Fixed routing subtrees. 21 */ 22 23 #define pr_fmt(fmt) "IPv6: " fmt 24 25 #include <linux/capability.h> 26 #include <linux/errno.h> 27 #include <linux/export.h> 28 #include <linux/types.h> 29 #include <linux/times.h> 30 #include <linux/socket.h> 31 #include <linux/sockios.h> 32 #include <linux/net.h> 33 #include <linux/route.h> 34 #include <linux/netdevice.h> 35 #include <linux/in6.h> 36 #include <linux/mroute6.h> 37 #include <linux/init.h> 38 #include <linux/if_arp.h> 39 #include <linux/proc_fs.h> 40 #include <linux/seq_file.h> 41 #include <linux/nsproxy.h> 42 #include <linux/slab.h> 43 #include <linux/jhash.h> 44 #include <linux/siphash.h> 45 #include <net/net_namespace.h> 46 #include <net/snmp.h> 47 #include <net/ipv6.h> 48 #include <net/ip6_fib.h> 49 #include <net/ip6_route.h> 50 #include <net/ndisc.h> 51 #include <net/addrconf.h> 52 #include <net/tcp.h> 53 #include <linux/rtnetlink.h> 54 #include <net/dst.h> 55 #include <net/dst_metadata.h> 56 #include <net/xfrm.h> 57 #include <net/netevent.h> 58 #include <net/netlink.h> 59 #include <net/rtnh.h> 60 #include <net/lwtunnel.h> 61 #include <net/ip_tunnels.h> 62 #include <net/l3mdev.h> 63 #include <net/ip.h> 64 #include <linux/uaccess.h> 65 #include <linux/btf_ids.h> 66 67 #ifdef CONFIG_SYSCTL 68 #include <linux/sysctl.h> 69 #endif 70 71 static int ip6_rt_type_to_error(u8 fib6_type); 72 73 #define CREATE_TRACE_POINTS 74 #include <trace/events/fib6.h> 75 EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup); 76 #undef CREATE_TRACE_POINTS 77 78 enum rt6_nud_state { 79 RT6_NUD_FAIL_HARD = -3, 80 RT6_NUD_FAIL_PROBE = -2, 81 RT6_NUD_FAIL_DO_RR = -1, 82 RT6_NUD_SUCCEED = 1 83 }; 84 85 INDIRECT_CALLABLE_SCOPE 86 struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); 87 static unsigned int ip6_default_advmss(const struct dst_entry *dst); 88 INDIRECT_CALLABLE_SCOPE 89 unsigned int ip6_mtu(const struct dst_entry *dst); 90 static void ip6_negative_advice(struct sock *sk, 91 struct dst_entry *dst); 92 static void ip6_dst_destroy(struct dst_entry *); 93 static void ip6_dst_ifdown(struct dst_entry *, 94 struct net_device *dev); 95 static void ip6_dst_gc(struct dst_ops *ops); 96 97 static int ip6_pkt_discard(struct sk_buff *skb); 98 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb); 99 static int ip6_pkt_prohibit(struct sk_buff *skb); 100 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb); 101 static void ip6_link_failure(struct sk_buff *skb); 102 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 103 struct sk_buff *skb, u32 mtu, 104 bool confirm_neigh); 105 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, 106 struct sk_buff *skb); 107 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, 108 int strict); 109 static size_t rt6_nlmsg_size(struct fib6_info *f6i); 110 static int rt6_fill_node(struct net *net, struct sk_buff *skb, 111 struct fib6_info *rt, struct dst_entry *dst, 112 struct in6_addr *dest, struct in6_addr *src, 113 int iif, int type, u32 portid, u32 seq, 114 unsigned int flags); 115 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res, 116 const struct in6_addr *daddr, 117 const struct in6_addr *saddr); 118 119 #ifdef CONFIG_IPV6_ROUTE_INFO 120 static struct fib6_info *rt6_add_route_info(struct net *net, 121 const struct in6_addr *prefix, int prefixlen, 122 const struct in6_addr *gwaddr, 123 struct net_device *dev, 124 unsigned int pref); 125 static struct fib6_info *rt6_get_route_info(struct net *net, 126 const struct in6_addr *prefix, int prefixlen, 127 const struct in6_addr *gwaddr, 128 struct net_device *dev); 129 #endif 130 131 struct uncached_list { 132 spinlock_t lock; 133 struct list_head head; 134 struct list_head quarantine; 135 }; 136 137 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list); 138 139 void rt6_uncached_list_add(struct rt6_info *rt) 140 { 141 struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list); 142 143 rt->dst.rt_uncached_list = ul; 144 145 spin_lock_bh(&ul->lock); 146 list_add_tail(&rt->dst.rt_uncached, &ul->head); 147 spin_unlock_bh(&ul->lock); 148 } 149 150 void rt6_uncached_list_del(struct rt6_info *rt) 151 { 152 if (!list_empty(&rt->dst.rt_uncached)) { 153 struct uncached_list *ul = rt->dst.rt_uncached_list; 154 155 spin_lock_bh(&ul->lock); 156 list_del_init(&rt->dst.rt_uncached); 157 spin_unlock_bh(&ul->lock); 158 } 159 } 160 161 static void rt6_uncached_list_flush_dev(struct net_device *dev) 162 { 163 int cpu; 164 165 for_each_possible_cpu(cpu) { 166 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); 167 struct rt6_info *rt, *safe; 168 169 if (list_empty(&ul->head)) 170 continue; 171 172 spin_lock_bh(&ul->lock); 173 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 174 struct inet6_dev *rt_idev = rt->rt6i_idev; 175 struct net_device *rt_dev = rt->dst.dev; 176 bool handled = false; 177 178 if (rt_idev && rt_idev->dev == dev) { 179 rt->rt6i_idev = in6_dev_get(blackhole_netdev); 180 in6_dev_put(rt_idev); 181 handled = true; 182 } 183 184 if (rt_dev == dev) { 185 rt->dst.dev = blackhole_netdev; 186 netdev_ref_replace(rt_dev, blackhole_netdev, 187 &rt->dst.dev_tracker, 188 GFP_ATOMIC); 189 handled = true; 190 } 191 if (handled) 192 list_move(&rt->dst.rt_uncached, 193 &ul->quarantine); 194 } 195 spin_unlock_bh(&ul->lock); 196 } 197 } 198 199 static inline const void *choose_neigh_daddr(const struct in6_addr *p, 200 struct sk_buff *skb, 201 const void *daddr) 202 { 203 if (!ipv6_addr_any(p)) 204 return (const void *) p; 205 else if (skb) 206 return &ipv6_hdr(skb)->daddr; 207 return daddr; 208 } 209 210 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 211 struct net_device *dev, 212 struct sk_buff *skb, 213 const void *daddr) 214 { 215 struct neighbour *n; 216 217 daddr = choose_neigh_daddr(gw, skb, daddr); 218 n = __ipv6_neigh_lookup(dev, daddr); 219 if (n) 220 return n; 221 222 n = neigh_create(&nd_tbl, daddr, dev); 223 return IS_ERR(n) ? NULL : n; 224 } 225 226 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst, 227 struct sk_buff *skb, 228 const void *daddr) 229 { 230 const struct rt6_info *rt = container_of(dst, struct rt6_info, dst); 231 232 return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any), 233 dst->dev, skb, daddr); 234 } 235 236 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr) 237 { 238 struct net_device *dev = dst->dev; 239 struct rt6_info *rt = (struct rt6_info *)dst; 240 241 daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr); 242 if (!daddr) 243 return; 244 if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) 245 return; 246 if (ipv6_addr_is_multicast((const struct in6_addr *)daddr)) 247 return; 248 __ipv6_confirm_neigh(dev, daddr); 249 } 250 251 static struct dst_ops ip6_dst_ops_template = { 252 .family = AF_INET6, 253 .gc = ip6_dst_gc, 254 .gc_thresh = 1024, 255 .check = ip6_dst_check, 256 .default_advmss = ip6_default_advmss, 257 .mtu = ip6_mtu, 258 .cow_metrics = dst_cow_metrics_generic, 259 .destroy = ip6_dst_destroy, 260 .ifdown = ip6_dst_ifdown, 261 .negative_advice = ip6_negative_advice, 262 .link_failure = ip6_link_failure, 263 .update_pmtu = ip6_rt_update_pmtu, 264 .redirect = rt6_do_redirect, 265 .local_out = __ip6_local_out, 266 .neigh_lookup = ip6_dst_neigh_lookup, 267 .confirm_neigh = ip6_confirm_neigh, 268 }; 269 270 static struct dst_ops ip6_dst_blackhole_ops = { 271 .family = AF_INET6, 272 .default_advmss = ip6_default_advmss, 273 .neigh_lookup = ip6_dst_neigh_lookup, 274 .check = ip6_dst_check, 275 .destroy = ip6_dst_destroy, 276 .cow_metrics = dst_cow_metrics_generic, 277 .update_pmtu = dst_blackhole_update_pmtu, 278 .redirect = dst_blackhole_redirect, 279 .mtu = dst_blackhole_mtu, 280 }; 281 282 static const u32 ip6_template_metrics[RTAX_MAX] = { 283 [RTAX_HOPLIMIT - 1] = 0, 284 }; 285 286 static const struct fib6_info fib6_null_entry_template = { 287 .fib6_flags = (RTF_REJECT | RTF_NONEXTHOP), 288 .fib6_protocol = RTPROT_KERNEL, 289 .fib6_metric = ~(u32)0, 290 .fib6_ref = REFCOUNT_INIT(1), 291 .fib6_type = RTN_UNREACHABLE, 292 .fib6_metrics = (struct dst_metrics *)&dst_default_metrics, 293 }; 294 295 static const struct rt6_info ip6_null_entry_template = { 296 .dst = { 297 .__rcuref = RCUREF_INIT(1), 298 .__use = 1, 299 .obsolete = DST_OBSOLETE_FORCE_CHK, 300 .error = -ENETUNREACH, 301 .input = ip6_pkt_discard, 302 .output = ip6_pkt_discard_out, 303 }, 304 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 305 }; 306 307 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 308 309 static const struct rt6_info ip6_prohibit_entry_template = { 310 .dst = { 311 .__rcuref = RCUREF_INIT(1), 312 .__use = 1, 313 .obsolete = DST_OBSOLETE_FORCE_CHK, 314 .error = -EACCES, 315 .input = ip6_pkt_prohibit, 316 .output = ip6_pkt_prohibit_out, 317 }, 318 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 319 }; 320 321 static const struct rt6_info ip6_blk_hole_entry_template = { 322 .dst = { 323 .__rcuref = RCUREF_INIT(1), 324 .__use = 1, 325 .obsolete = DST_OBSOLETE_FORCE_CHK, 326 .error = -EINVAL, 327 .input = dst_discard, 328 .output = dst_discard_out, 329 }, 330 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 331 }; 332 333 #endif 334 335 static void rt6_info_init(struct rt6_info *rt) 336 { 337 memset_after(rt, 0, dst); 338 } 339 340 /* allocate dst with ip6_dst_ops */ 341 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 342 int flags) 343 { 344 struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev, 345 1, DST_OBSOLETE_FORCE_CHK, flags); 346 347 if (rt) { 348 rt6_info_init(rt); 349 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc); 350 } 351 352 return rt; 353 } 354 EXPORT_SYMBOL(ip6_dst_alloc); 355 356 static void ip6_dst_destroy(struct dst_entry *dst) 357 { 358 struct rt6_info *rt = (struct rt6_info *)dst; 359 struct fib6_info *from; 360 struct inet6_dev *idev; 361 362 ip_dst_metrics_put(dst); 363 rt6_uncached_list_del(rt); 364 365 idev = rt->rt6i_idev; 366 if (idev) { 367 rt->rt6i_idev = NULL; 368 in6_dev_put(idev); 369 } 370 371 from = xchg((__force struct fib6_info **)&rt->from, NULL); 372 fib6_info_release(from); 373 } 374 375 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev) 376 { 377 struct rt6_info *rt = (struct rt6_info *)dst; 378 struct inet6_dev *idev = rt->rt6i_idev; 379 380 if (idev && idev->dev != blackhole_netdev) { 381 struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev); 382 383 if (blackhole_idev) { 384 rt->rt6i_idev = blackhole_idev; 385 in6_dev_put(idev); 386 } 387 } 388 } 389 390 static bool __rt6_check_expired(const struct rt6_info *rt) 391 { 392 if (rt->rt6i_flags & RTF_EXPIRES) 393 return time_after(jiffies, rt->dst.expires); 394 else 395 return false; 396 } 397 398 static bool rt6_check_expired(const struct rt6_info *rt) 399 { 400 struct fib6_info *from; 401 402 from = rcu_dereference(rt->from); 403 404 if (rt->rt6i_flags & RTF_EXPIRES) { 405 if (time_after(jiffies, rt->dst.expires)) 406 return true; 407 } else if (from) { 408 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK || 409 fib6_check_expired(from); 410 } 411 return false; 412 } 413 414 void fib6_select_path(const struct net *net, struct fib6_result *res, 415 struct flowi6 *fl6, int oif, bool have_oif_match, 416 const struct sk_buff *skb, int strict) 417 { 418 struct fib6_info *sibling, *next_sibling; 419 struct fib6_info *match = res->f6i; 420 421 if (!match->nh && (!match->fib6_nsiblings || have_oif_match)) 422 goto out; 423 424 if (match->nh && have_oif_match && res->nh) 425 return; 426 427 if (skb) 428 IP6CB(skb)->flags |= IP6SKB_MULTIPATH; 429 430 /* We might have already computed the hash for ICMPv6 errors. In such 431 * case it will always be non-zero. Otherwise now is the time to do it. 432 */ 433 if (!fl6->mp_hash && 434 (!match->nh || nexthop_is_multipath(match->nh))) 435 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL); 436 437 if (unlikely(match->nh)) { 438 nexthop_path_fib6_result(res, fl6->mp_hash); 439 return; 440 } 441 442 if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound)) 443 goto out; 444 445 list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings, 446 fib6_siblings) { 447 const struct fib6_nh *nh = sibling->fib6_nh; 448 int nh_upper_bound; 449 450 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound); 451 if (fl6->mp_hash > nh_upper_bound) 452 continue; 453 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0) 454 break; 455 match = sibling; 456 break; 457 } 458 459 out: 460 res->f6i = match; 461 res->nh = match->fib6_nh; 462 } 463 464 /* 465 * Route lookup. rcu_read_lock() should be held. 466 */ 467 468 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh, 469 const struct in6_addr *saddr, int oif, int flags) 470 { 471 const struct net_device *dev; 472 473 if (nh->fib_nh_flags & RTNH_F_DEAD) 474 return false; 475 476 dev = nh->fib_nh_dev; 477 if (oif) { 478 if (dev->ifindex == oif) 479 return true; 480 } else { 481 if (ipv6_chk_addr(net, saddr, dev, 482 flags & RT6_LOOKUP_F_IFACE)) 483 return true; 484 } 485 486 return false; 487 } 488 489 struct fib6_nh_dm_arg { 490 struct net *net; 491 const struct in6_addr *saddr; 492 int oif; 493 int flags; 494 struct fib6_nh *nh; 495 }; 496 497 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg) 498 { 499 struct fib6_nh_dm_arg *arg = _arg; 500 501 arg->nh = nh; 502 return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif, 503 arg->flags); 504 } 505 506 /* returns fib6_nh from nexthop or NULL */ 507 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh, 508 struct fib6_result *res, 509 const struct in6_addr *saddr, 510 int oif, int flags) 511 { 512 struct fib6_nh_dm_arg arg = { 513 .net = net, 514 .saddr = saddr, 515 .oif = oif, 516 .flags = flags, 517 }; 518 519 if (nexthop_is_blackhole(nh)) 520 return NULL; 521 522 if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg)) 523 return arg.nh; 524 525 return NULL; 526 } 527 528 static void rt6_device_match(struct net *net, struct fib6_result *res, 529 const struct in6_addr *saddr, int oif, int flags) 530 { 531 struct fib6_info *f6i = res->f6i; 532 struct fib6_info *spf6i; 533 struct fib6_nh *nh; 534 535 if (!oif && ipv6_addr_any(saddr)) { 536 if (unlikely(f6i->nh)) { 537 nh = nexthop_fib6_nh(f6i->nh); 538 if (nexthop_is_blackhole(f6i->nh)) 539 goto out_blackhole; 540 } else { 541 nh = f6i->fib6_nh; 542 } 543 if (!(nh->fib_nh_flags & RTNH_F_DEAD)) 544 goto out; 545 } 546 547 for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) { 548 bool matched = false; 549 550 if (unlikely(spf6i->nh)) { 551 nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr, 552 oif, flags); 553 if (nh) 554 matched = true; 555 } else { 556 nh = spf6i->fib6_nh; 557 if (__rt6_device_match(net, nh, saddr, oif, flags)) 558 matched = true; 559 } 560 if (matched) { 561 res->f6i = spf6i; 562 goto out; 563 } 564 } 565 566 if (oif && flags & RT6_LOOKUP_F_IFACE) { 567 res->f6i = net->ipv6.fib6_null_entry; 568 nh = res->f6i->fib6_nh; 569 goto out; 570 } 571 572 if (unlikely(f6i->nh)) { 573 nh = nexthop_fib6_nh(f6i->nh); 574 if (nexthop_is_blackhole(f6i->nh)) 575 goto out_blackhole; 576 } else { 577 nh = f6i->fib6_nh; 578 } 579 580 if (nh->fib_nh_flags & RTNH_F_DEAD) { 581 res->f6i = net->ipv6.fib6_null_entry; 582 nh = res->f6i->fib6_nh; 583 } 584 out: 585 res->nh = nh; 586 res->fib6_type = res->f6i->fib6_type; 587 res->fib6_flags = res->f6i->fib6_flags; 588 return; 589 590 out_blackhole: 591 res->fib6_flags |= RTF_REJECT; 592 res->fib6_type = RTN_BLACKHOLE; 593 res->nh = nh; 594 } 595 596 #ifdef CONFIG_IPV6_ROUTER_PREF 597 struct __rt6_probe_work { 598 struct work_struct work; 599 struct in6_addr target; 600 struct net_device *dev; 601 netdevice_tracker dev_tracker; 602 }; 603 604 static void rt6_probe_deferred(struct work_struct *w) 605 { 606 struct in6_addr mcaddr; 607 struct __rt6_probe_work *work = 608 container_of(w, struct __rt6_probe_work, work); 609 610 addrconf_addr_solict_mult(&work->target, &mcaddr); 611 ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0); 612 netdev_put(work->dev, &work->dev_tracker); 613 kfree(work); 614 } 615 616 static void rt6_probe(struct fib6_nh *fib6_nh) 617 { 618 struct __rt6_probe_work *work = NULL; 619 const struct in6_addr *nh_gw; 620 unsigned long last_probe; 621 struct neighbour *neigh; 622 struct net_device *dev; 623 struct inet6_dev *idev; 624 625 /* 626 * Okay, this does not seem to be appropriate 627 * for now, however, we need to check if it 628 * is really so; aka Router Reachability Probing. 629 * 630 * Router Reachability Probe MUST be rate-limited 631 * to no more than one per minute. 632 */ 633 if (!fib6_nh->fib_nh_gw_family) 634 return; 635 636 nh_gw = &fib6_nh->fib_nh_gw6; 637 dev = fib6_nh->fib_nh_dev; 638 rcu_read_lock(); 639 last_probe = READ_ONCE(fib6_nh->last_probe); 640 idev = __in6_dev_get(dev); 641 if (!idev) 642 goto out; 643 neigh = __ipv6_neigh_lookup_noref(dev, nh_gw); 644 if (neigh) { 645 if (READ_ONCE(neigh->nud_state) & NUD_VALID) 646 goto out; 647 648 write_lock_bh(&neigh->lock); 649 if (!(neigh->nud_state & NUD_VALID) && 650 time_after(jiffies, 651 neigh->updated + idev->cnf.rtr_probe_interval)) { 652 work = kmalloc(sizeof(*work), GFP_ATOMIC); 653 if (work) 654 __neigh_set_probe_once(neigh); 655 } 656 write_unlock_bh(&neigh->lock); 657 } else if (time_after(jiffies, last_probe + 658 idev->cnf.rtr_probe_interval)) { 659 work = kmalloc(sizeof(*work), GFP_ATOMIC); 660 } 661 662 if (!work || cmpxchg(&fib6_nh->last_probe, 663 last_probe, jiffies) != last_probe) { 664 kfree(work); 665 } else { 666 INIT_WORK(&work->work, rt6_probe_deferred); 667 work->target = *nh_gw; 668 netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC); 669 work->dev = dev; 670 schedule_work(&work->work); 671 } 672 673 out: 674 rcu_read_unlock(); 675 } 676 #else 677 static inline void rt6_probe(struct fib6_nh *fib6_nh) 678 { 679 } 680 #endif 681 682 /* 683 * Default Router Selection (RFC 2461 6.3.6) 684 */ 685 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh) 686 { 687 enum rt6_nud_state ret = RT6_NUD_FAIL_HARD; 688 struct neighbour *neigh; 689 690 rcu_read_lock(); 691 neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev, 692 &fib6_nh->fib_nh_gw6); 693 if (neigh) { 694 u8 nud_state = READ_ONCE(neigh->nud_state); 695 696 if (nud_state & NUD_VALID) 697 ret = RT6_NUD_SUCCEED; 698 #ifdef CONFIG_IPV6_ROUTER_PREF 699 else if (!(nud_state & NUD_FAILED)) 700 ret = RT6_NUD_SUCCEED; 701 else 702 ret = RT6_NUD_FAIL_PROBE; 703 #endif 704 } else { 705 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ? 706 RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR; 707 } 708 rcu_read_unlock(); 709 710 return ret; 711 } 712 713 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, 714 int strict) 715 { 716 int m = 0; 717 718 if (!oif || nh->fib_nh_dev->ifindex == oif) 719 m = 2; 720 721 if (!m && (strict & RT6_LOOKUP_F_IFACE)) 722 return RT6_NUD_FAIL_HARD; 723 #ifdef CONFIG_IPV6_ROUTER_PREF 724 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2; 725 #endif 726 if ((strict & RT6_LOOKUP_F_REACHABLE) && 727 !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) { 728 int n = rt6_check_neigh(nh); 729 if (n < 0) 730 return n; 731 } 732 return m; 733 } 734 735 static bool find_match(struct fib6_nh *nh, u32 fib6_flags, 736 int oif, int strict, int *mpri, bool *do_rr) 737 { 738 bool match_do_rr = false; 739 bool rc = false; 740 int m; 741 742 if (nh->fib_nh_flags & RTNH_F_DEAD) 743 goto out; 744 745 if (ip6_ignore_linkdown(nh->fib_nh_dev) && 746 nh->fib_nh_flags & RTNH_F_LINKDOWN && 747 !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE)) 748 goto out; 749 750 m = rt6_score_route(nh, fib6_flags, oif, strict); 751 if (m == RT6_NUD_FAIL_DO_RR) { 752 match_do_rr = true; 753 m = 0; /* lowest valid score */ 754 } else if (m == RT6_NUD_FAIL_HARD) { 755 goto out; 756 } 757 758 if (strict & RT6_LOOKUP_F_REACHABLE) 759 rt6_probe(nh); 760 761 /* note that m can be RT6_NUD_FAIL_PROBE at this point */ 762 if (m > *mpri) { 763 *do_rr = match_do_rr; 764 *mpri = m; 765 rc = true; 766 } 767 out: 768 return rc; 769 } 770 771 struct fib6_nh_frl_arg { 772 u32 flags; 773 int oif; 774 int strict; 775 int *mpri; 776 bool *do_rr; 777 struct fib6_nh *nh; 778 }; 779 780 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg) 781 { 782 struct fib6_nh_frl_arg *arg = _arg; 783 784 arg->nh = nh; 785 return find_match(nh, arg->flags, arg->oif, arg->strict, 786 arg->mpri, arg->do_rr); 787 } 788 789 static void __find_rr_leaf(struct fib6_info *f6i_start, 790 struct fib6_info *nomatch, u32 metric, 791 struct fib6_result *res, struct fib6_info **cont, 792 int oif, int strict, bool *do_rr, int *mpri) 793 { 794 struct fib6_info *f6i; 795 796 for (f6i = f6i_start; 797 f6i && f6i != nomatch; 798 f6i = rcu_dereference(f6i->fib6_next)) { 799 bool matched = false; 800 struct fib6_nh *nh; 801 802 if (cont && f6i->fib6_metric != metric) { 803 *cont = f6i; 804 return; 805 } 806 807 if (fib6_check_expired(f6i)) 808 continue; 809 810 if (unlikely(f6i->nh)) { 811 struct fib6_nh_frl_arg arg = { 812 .flags = f6i->fib6_flags, 813 .oif = oif, 814 .strict = strict, 815 .mpri = mpri, 816 .do_rr = do_rr 817 }; 818 819 if (nexthop_is_blackhole(f6i->nh)) { 820 res->fib6_flags = RTF_REJECT; 821 res->fib6_type = RTN_BLACKHOLE; 822 res->f6i = f6i; 823 res->nh = nexthop_fib6_nh(f6i->nh); 824 return; 825 } 826 if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match, 827 &arg)) { 828 matched = true; 829 nh = arg.nh; 830 } 831 } else { 832 nh = f6i->fib6_nh; 833 if (find_match(nh, f6i->fib6_flags, oif, strict, 834 mpri, do_rr)) 835 matched = true; 836 } 837 if (matched) { 838 res->f6i = f6i; 839 res->nh = nh; 840 res->fib6_flags = f6i->fib6_flags; 841 res->fib6_type = f6i->fib6_type; 842 } 843 } 844 } 845 846 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf, 847 struct fib6_info *rr_head, int oif, int strict, 848 bool *do_rr, struct fib6_result *res) 849 { 850 u32 metric = rr_head->fib6_metric; 851 struct fib6_info *cont = NULL; 852 int mpri = -1; 853 854 __find_rr_leaf(rr_head, NULL, metric, res, &cont, 855 oif, strict, do_rr, &mpri); 856 857 __find_rr_leaf(leaf, rr_head, metric, res, &cont, 858 oif, strict, do_rr, &mpri); 859 860 if (res->f6i || !cont) 861 return; 862 863 __find_rr_leaf(cont, NULL, metric, res, NULL, 864 oif, strict, do_rr, &mpri); 865 } 866 867 static void rt6_select(struct net *net, struct fib6_node *fn, int oif, 868 struct fib6_result *res, int strict) 869 { 870 struct fib6_info *leaf = rcu_dereference(fn->leaf); 871 struct fib6_info *rt0; 872 bool do_rr = false; 873 int key_plen; 874 875 /* make sure this function or its helpers sets f6i */ 876 res->f6i = NULL; 877 878 if (!leaf || leaf == net->ipv6.fib6_null_entry) 879 goto out; 880 881 rt0 = rcu_dereference(fn->rr_ptr); 882 if (!rt0) 883 rt0 = leaf; 884 885 /* Double check to make sure fn is not an intermediate node 886 * and fn->leaf does not points to its child's leaf 887 * (This might happen if all routes under fn are deleted from 888 * the tree and fib6_repair_tree() is called on the node.) 889 */ 890 key_plen = rt0->fib6_dst.plen; 891 #ifdef CONFIG_IPV6_SUBTREES 892 if (rt0->fib6_src.plen) 893 key_plen = rt0->fib6_src.plen; 894 #endif 895 if (fn->fn_bit != key_plen) 896 goto out; 897 898 find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res); 899 if (do_rr) { 900 struct fib6_info *next = rcu_dereference(rt0->fib6_next); 901 902 /* no entries matched; do round-robin */ 903 if (!next || next->fib6_metric != rt0->fib6_metric) 904 next = leaf; 905 906 if (next != rt0) { 907 spin_lock_bh(&leaf->fib6_table->tb6_lock); 908 /* make sure next is not being deleted from the tree */ 909 if (next->fib6_node) 910 rcu_assign_pointer(fn->rr_ptr, next); 911 spin_unlock_bh(&leaf->fib6_table->tb6_lock); 912 } 913 } 914 915 out: 916 if (!res->f6i) { 917 res->f6i = net->ipv6.fib6_null_entry; 918 res->nh = res->f6i->fib6_nh; 919 res->fib6_flags = res->f6i->fib6_flags; 920 res->fib6_type = res->f6i->fib6_type; 921 } 922 } 923 924 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res) 925 { 926 return (res->f6i->fib6_flags & RTF_NONEXTHOP) || 927 res->nh->fib_nh_gw_family; 928 } 929 930 #ifdef CONFIG_IPV6_ROUTE_INFO 931 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 932 const struct in6_addr *gwaddr) 933 { 934 struct net *net = dev_net(dev); 935 struct route_info *rinfo = (struct route_info *) opt; 936 struct in6_addr prefix_buf, *prefix; 937 unsigned int pref; 938 unsigned long lifetime; 939 struct fib6_info *rt; 940 941 if (len < sizeof(struct route_info)) { 942 return -EINVAL; 943 } 944 945 /* Sanity check for prefix_len and length */ 946 if (rinfo->length > 3) { 947 return -EINVAL; 948 } else if (rinfo->prefix_len > 128) { 949 return -EINVAL; 950 } else if (rinfo->prefix_len > 64) { 951 if (rinfo->length < 2) { 952 return -EINVAL; 953 } 954 } else if (rinfo->prefix_len > 0) { 955 if (rinfo->length < 1) { 956 return -EINVAL; 957 } 958 } 959 960 pref = rinfo->route_pref; 961 if (pref == ICMPV6_ROUTER_PREF_INVALID) 962 return -EINVAL; 963 964 lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ); 965 966 if (rinfo->length == 3) 967 prefix = (struct in6_addr *)rinfo->prefix; 968 else { 969 /* this function is safe */ 970 ipv6_addr_prefix(&prefix_buf, 971 (struct in6_addr *)rinfo->prefix, 972 rinfo->prefix_len); 973 prefix = &prefix_buf; 974 } 975 976 if (rinfo->prefix_len == 0) 977 rt = rt6_get_dflt_router(net, gwaddr, dev); 978 else 979 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len, 980 gwaddr, dev); 981 982 if (rt && !lifetime) { 983 ip6_del_rt(net, rt, false); 984 rt = NULL; 985 } 986 987 if (!rt && lifetime) 988 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, 989 dev, pref); 990 else if (rt) 991 rt->fib6_flags = RTF_ROUTEINFO | 992 (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 993 994 if (rt) { 995 if (!addrconf_finite_timeout(lifetime)) 996 fib6_clean_expires(rt); 997 else 998 fib6_set_expires(rt, jiffies + HZ * lifetime); 999 1000 fib6_info_release(rt); 1001 } 1002 return 0; 1003 } 1004 #endif 1005 1006 /* 1007 * Misc support functions 1008 */ 1009 1010 /* called with rcu_lock held */ 1011 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res) 1012 { 1013 struct net_device *dev = res->nh->fib_nh_dev; 1014 1015 if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) { 1016 /* for copies of local routes, dst->dev needs to be the 1017 * device if it is a master device, the master device if 1018 * device is enslaved, and the loopback as the default 1019 */ 1020 if (netif_is_l3_slave(dev) && 1021 !rt6_need_strict(&res->f6i->fib6_dst.addr)) 1022 dev = l3mdev_master_dev_rcu(dev); 1023 else if (!netif_is_l3_master(dev)) 1024 dev = dev_net(dev)->loopback_dev; 1025 /* last case is netif_is_l3_master(dev) is true in which 1026 * case we want dev returned to be dev 1027 */ 1028 } 1029 1030 return dev; 1031 } 1032 1033 static const int fib6_prop[RTN_MAX + 1] = { 1034 [RTN_UNSPEC] = 0, 1035 [RTN_UNICAST] = 0, 1036 [RTN_LOCAL] = 0, 1037 [RTN_BROADCAST] = 0, 1038 [RTN_ANYCAST] = 0, 1039 [RTN_MULTICAST] = 0, 1040 [RTN_BLACKHOLE] = -EINVAL, 1041 [RTN_UNREACHABLE] = -EHOSTUNREACH, 1042 [RTN_PROHIBIT] = -EACCES, 1043 [RTN_THROW] = -EAGAIN, 1044 [RTN_NAT] = -EINVAL, 1045 [RTN_XRESOLVE] = -EINVAL, 1046 }; 1047 1048 static int ip6_rt_type_to_error(u8 fib6_type) 1049 { 1050 return fib6_prop[fib6_type]; 1051 } 1052 1053 static unsigned short fib6_info_dst_flags(struct fib6_info *rt) 1054 { 1055 unsigned short flags = 0; 1056 1057 if (rt->dst_nocount) 1058 flags |= DST_NOCOUNT; 1059 if (rt->dst_nopolicy) 1060 flags |= DST_NOPOLICY; 1061 1062 return flags; 1063 } 1064 1065 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type) 1066 { 1067 rt->dst.error = ip6_rt_type_to_error(fib6_type); 1068 1069 switch (fib6_type) { 1070 case RTN_BLACKHOLE: 1071 rt->dst.output = dst_discard_out; 1072 rt->dst.input = dst_discard; 1073 break; 1074 case RTN_PROHIBIT: 1075 rt->dst.output = ip6_pkt_prohibit_out; 1076 rt->dst.input = ip6_pkt_prohibit; 1077 break; 1078 case RTN_THROW: 1079 case RTN_UNREACHABLE: 1080 default: 1081 rt->dst.output = ip6_pkt_discard_out; 1082 rt->dst.input = ip6_pkt_discard; 1083 break; 1084 } 1085 } 1086 1087 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res) 1088 { 1089 struct fib6_info *f6i = res->f6i; 1090 1091 if (res->fib6_flags & RTF_REJECT) { 1092 ip6_rt_init_dst_reject(rt, res->fib6_type); 1093 return; 1094 } 1095 1096 rt->dst.error = 0; 1097 rt->dst.output = ip6_output; 1098 1099 if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) { 1100 rt->dst.input = ip6_input; 1101 } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) { 1102 rt->dst.input = ip6_mc_input; 1103 } else { 1104 rt->dst.input = ip6_forward; 1105 } 1106 1107 if (res->nh->fib_nh_lws) { 1108 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws); 1109 lwtunnel_set_redirect(&rt->dst); 1110 } 1111 1112 rt->dst.lastuse = jiffies; 1113 } 1114 1115 /* Caller must already hold reference to @from */ 1116 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from) 1117 { 1118 rt->rt6i_flags &= ~RTF_EXPIRES; 1119 rcu_assign_pointer(rt->from, from); 1120 ip_dst_init_metrics(&rt->dst, from->fib6_metrics); 1121 } 1122 1123 /* Caller must already hold reference to f6i in result */ 1124 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res) 1125 { 1126 const struct fib6_nh *nh = res->nh; 1127 const struct net_device *dev = nh->fib_nh_dev; 1128 struct fib6_info *f6i = res->f6i; 1129 1130 ip6_rt_init_dst(rt, res); 1131 1132 rt->rt6i_dst = f6i->fib6_dst; 1133 rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL; 1134 rt->rt6i_flags = res->fib6_flags; 1135 if (nh->fib_nh_gw_family) { 1136 rt->rt6i_gateway = nh->fib_nh_gw6; 1137 rt->rt6i_flags |= RTF_GATEWAY; 1138 } 1139 rt6_set_from(rt, f6i); 1140 #ifdef CONFIG_IPV6_SUBTREES 1141 rt->rt6i_src = f6i->fib6_src; 1142 #endif 1143 } 1144 1145 static struct fib6_node* fib6_backtrack(struct fib6_node *fn, 1146 struct in6_addr *saddr) 1147 { 1148 struct fib6_node *pn, *sn; 1149 while (1) { 1150 if (fn->fn_flags & RTN_TL_ROOT) 1151 return NULL; 1152 pn = rcu_dereference(fn->parent); 1153 sn = FIB6_SUBTREE(pn); 1154 if (sn && sn != fn) 1155 fn = fib6_node_lookup(sn, NULL, saddr); 1156 else 1157 fn = pn; 1158 if (fn->fn_flags & RTN_RTINFO) 1159 return fn; 1160 } 1161 } 1162 1163 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt) 1164 { 1165 struct rt6_info *rt = *prt; 1166 1167 if (dst_hold_safe(&rt->dst)) 1168 return true; 1169 if (net) { 1170 rt = net->ipv6.ip6_null_entry; 1171 dst_hold(&rt->dst); 1172 } else { 1173 rt = NULL; 1174 } 1175 *prt = rt; 1176 return false; 1177 } 1178 1179 /* called with rcu_lock held */ 1180 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res) 1181 { 1182 struct net_device *dev = res->nh->fib_nh_dev; 1183 struct fib6_info *f6i = res->f6i; 1184 unsigned short flags; 1185 struct rt6_info *nrt; 1186 1187 if (!fib6_info_hold_safe(f6i)) 1188 goto fallback; 1189 1190 flags = fib6_info_dst_flags(f6i); 1191 nrt = ip6_dst_alloc(dev_net(dev), dev, flags); 1192 if (!nrt) { 1193 fib6_info_release(f6i); 1194 goto fallback; 1195 } 1196 1197 ip6_rt_copy_init(nrt, res); 1198 return nrt; 1199 1200 fallback: 1201 nrt = dev_net(dev)->ipv6.ip6_null_entry; 1202 dst_hold(&nrt->dst); 1203 return nrt; 1204 } 1205 1206 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net, 1207 struct fib6_table *table, 1208 struct flowi6 *fl6, 1209 const struct sk_buff *skb, 1210 int flags) 1211 { 1212 struct fib6_result res = {}; 1213 struct fib6_node *fn; 1214 struct rt6_info *rt; 1215 1216 rcu_read_lock(); 1217 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 1218 restart: 1219 res.f6i = rcu_dereference(fn->leaf); 1220 if (!res.f6i) 1221 res.f6i = net->ipv6.fib6_null_entry; 1222 else 1223 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif, 1224 flags); 1225 1226 if (res.f6i == net->ipv6.fib6_null_entry) { 1227 fn = fib6_backtrack(fn, &fl6->saddr); 1228 if (fn) 1229 goto restart; 1230 1231 rt = net->ipv6.ip6_null_entry; 1232 dst_hold(&rt->dst); 1233 goto out; 1234 } else if (res.fib6_flags & RTF_REJECT) { 1235 goto do_create; 1236 } 1237 1238 fib6_select_path(net, &res, fl6, fl6->flowi6_oif, 1239 fl6->flowi6_oif != 0, skb, flags); 1240 1241 /* Search through exception table */ 1242 rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr); 1243 if (rt) { 1244 if (ip6_hold_safe(net, &rt)) 1245 dst_use_noref(&rt->dst, jiffies); 1246 } else { 1247 do_create: 1248 rt = ip6_create_rt_rcu(&res); 1249 } 1250 1251 out: 1252 trace_fib6_table_lookup(net, &res, table, fl6); 1253 1254 rcu_read_unlock(); 1255 1256 return rt; 1257 } 1258 1259 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 1260 const struct sk_buff *skb, int flags) 1261 { 1262 return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup); 1263 } 1264 EXPORT_SYMBOL_GPL(ip6_route_lookup); 1265 1266 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 1267 const struct in6_addr *saddr, int oif, 1268 const struct sk_buff *skb, int strict) 1269 { 1270 struct flowi6 fl6 = { 1271 .flowi6_oif = oif, 1272 .daddr = *daddr, 1273 }; 1274 struct dst_entry *dst; 1275 int flags = strict ? RT6_LOOKUP_F_IFACE : 0; 1276 1277 if (saddr) { 1278 memcpy(&fl6.saddr, saddr, sizeof(*saddr)); 1279 flags |= RT6_LOOKUP_F_HAS_SADDR; 1280 } 1281 1282 dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup); 1283 if (dst->error == 0) 1284 return (struct rt6_info *) dst; 1285 1286 dst_release(dst); 1287 1288 return NULL; 1289 } 1290 EXPORT_SYMBOL(rt6_lookup); 1291 1292 /* ip6_ins_rt is called with FREE table->tb6_lock. 1293 * It takes new route entry, the addition fails by any reason the 1294 * route is released. 1295 * Caller must hold dst before calling it. 1296 */ 1297 1298 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info, 1299 struct netlink_ext_ack *extack) 1300 { 1301 int err; 1302 struct fib6_table *table; 1303 1304 table = rt->fib6_table; 1305 spin_lock_bh(&table->tb6_lock); 1306 err = fib6_add(&table->tb6_root, rt, info, extack); 1307 spin_unlock_bh(&table->tb6_lock); 1308 1309 return err; 1310 } 1311 1312 int ip6_ins_rt(struct net *net, struct fib6_info *rt) 1313 { 1314 struct nl_info info = { .nl_net = net, }; 1315 1316 return __ip6_ins_rt(rt, &info, NULL); 1317 } 1318 1319 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res, 1320 const struct in6_addr *daddr, 1321 const struct in6_addr *saddr) 1322 { 1323 struct fib6_info *f6i = res->f6i; 1324 struct net_device *dev; 1325 struct rt6_info *rt; 1326 1327 /* 1328 * Clone the route. 1329 */ 1330 1331 if (!fib6_info_hold_safe(f6i)) 1332 return NULL; 1333 1334 dev = ip6_rt_get_dev_rcu(res); 1335 rt = ip6_dst_alloc(dev_net(dev), dev, 0); 1336 if (!rt) { 1337 fib6_info_release(f6i); 1338 return NULL; 1339 } 1340 1341 ip6_rt_copy_init(rt, res); 1342 rt->rt6i_flags |= RTF_CACHE; 1343 rt->rt6i_dst.addr = *daddr; 1344 rt->rt6i_dst.plen = 128; 1345 1346 if (!rt6_is_gw_or_nonexthop(res)) { 1347 if (f6i->fib6_dst.plen != 128 && 1348 ipv6_addr_equal(&f6i->fib6_dst.addr, daddr)) 1349 rt->rt6i_flags |= RTF_ANYCAST; 1350 #ifdef CONFIG_IPV6_SUBTREES 1351 if (rt->rt6i_src.plen && saddr) { 1352 rt->rt6i_src.addr = *saddr; 1353 rt->rt6i_src.plen = 128; 1354 } 1355 #endif 1356 } 1357 1358 return rt; 1359 } 1360 1361 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res) 1362 { 1363 struct fib6_info *f6i = res->f6i; 1364 unsigned short flags = fib6_info_dst_flags(f6i); 1365 struct net_device *dev; 1366 struct rt6_info *pcpu_rt; 1367 1368 if (!fib6_info_hold_safe(f6i)) 1369 return NULL; 1370 1371 rcu_read_lock(); 1372 dev = ip6_rt_get_dev_rcu(res); 1373 pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT); 1374 rcu_read_unlock(); 1375 if (!pcpu_rt) { 1376 fib6_info_release(f6i); 1377 return NULL; 1378 } 1379 ip6_rt_copy_init(pcpu_rt, res); 1380 pcpu_rt->rt6i_flags |= RTF_PCPU; 1381 1382 if (f6i->nh) 1383 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev)); 1384 1385 return pcpu_rt; 1386 } 1387 1388 static bool rt6_is_valid(const struct rt6_info *rt6) 1389 { 1390 return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev)); 1391 } 1392 1393 /* It should be called with rcu_read_lock() acquired */ 1394 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res) 1395 { 1396 struct rt6_info *pcpu_rt; 1397 1398 pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu); 1399 1400 if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) { 1401 struct rt6_info *prev, **p; 1402 1403 p = this_cpu_ptr(res->nh->rt6i_pcpu); 1404 /* Paired with READ_ONCE() in __fib6_drop_pcpu_from() */ 1405 prev = xchg(p, NULL); 1406 if (prev) { 1407 dst_dev_put(&prev->dst); 1408 dst_release(&prev->dst); 1409 } 1410 1411 pcpu_rt = NULL; 1412 } 1413 1414 return pcpu_rt; 1415 } 1416 1417 static struct rt6_info *rt6_make_pcpu_route(struct net *net, 1418 const struct fib6_result *res) 1419 { 1420 struct rt6_info *pcpu_rt, *prev, **p; 1421 1422 pcpu_rt = ip6_rt_pcpu_alloc(res); 1423 if (!pcpu_rt) 1424 return NULL; 1425 1426 p = this_cpu_ptr(res->nh->rt6i_pcpu); 1427 prev = cmpxchg(p, NULL, pcpu_rt); 1428 BUG_ON(prev); 1429 1430 if (res->f6i->fib6_destroying) { 1431 struct fib6_info *from; 1432 1433 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); 1434 fib6_info_release(from); 1435 } 1436 1437 return pcpu_rt; 1438 } 1439 1440 /* exception hash table implementation 1441 */ 1442 static DEFINE_SPINLOCK(rt6_exception_lock); 1443 1444 /* Remove rt6_ex from hash table and free the memory 1445 * Caller must hold rt6_exception_lock 1446 */ 1447 static void rt6_remove_exception(struct rt6_exception_bucket *bucket, 1448 struct rt6_exception *rt6_ex) 1449 { 1450 struct fib6_info *from; 1451 struct net *net; 1452 1453 if (!bucket || !rt6_ex) 1454 return; 1455 1456 net = dev_net(rt6_ex->rt6i->dst.dev); 1457 net->ipv6.rt6_stats->fib_rt_cache--; 1458 1459 /* purge completely the exception to allow releasing the held resources: 1460 * some [sk] cache may keep the dst around for unlimited time 1461 */ 1462 from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL); 1463 fib6_info_release(from); 1464 dst_dev_put(&rt6_ex->rt6i->dst); 1465 1466 hlist_del_rcu(&rt6_ex->hlist); 1467 dst_release(&rt6_ex->rt6i->dst); 1468 kfree_rcu(rt6_ex, rcu); 1469 WARN_ON_ONCE(!bucket->depth); 1470 bucket->depth--; 1471 } 1472 1473 /* Remove oldest rt6_ex in bucket and free the memory 1474 * Caller must hold rt6_exception_lock 1475 */ 1476 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket) 1477 { 1478 struct rt6_exception *rt6_ex, *oldest = NULL; 1479 1480 if (!bucket) 1481 return; 1482 1483 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { 1484 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp)) 1485 oldest = rt6_ex; 1486 } 1487 rt6_remove_exception(bucket, oldest); 1488 } 1489 1490 static u32 rt6_exception_hash(const struct in6_addr *dst, 1491 const struct in6_addr *src) 1492 { 1493 static siphash_aligned_key_t rt6_exception_key; 1494 struct { 1495 struct in6_addr dst; 1496 struct in6_addr src; 1497 } __aligned(SIPHASH_ALIGNMENT) combined = { 1498 .dst = *dst, 1499 }; 1500 u64 val; 1501 1502 net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key)); 1503 1504 #ifdef CONFIG_IPV6_SUBTREES 1505 if (src) 1506 combined.src = *src; 1507 #endif 1508 val = siphash(&combined, sizeof(combined), &rt6_exception_key); 1509 1510 return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT); 1511 } 1512 1513 /* Helper function to find the cached rt in the hash table 1514 * and update bucket pointer to point to the bucket for this 1515 * (daddr, saddr) pair 1516 * Caller must hold rt6_exception_lock 1517 */ 1518 static struct rt6_exception * 1519 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket, 1520 const struct in6_addr *daddr, 1521 const struct in6_addr *saddr) 1522 { 1523 struct rt6_exception *rt6_ex; 1524 u32 hval; 1525 1526 if (!(*bucket) || !daddr) 1527 return NULL; 1528 1529 hval = rt6_exception_hash(daddr, saddr); 1530 *bucket += hval; 1531 1532 hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) { 1533 struct rt6_info *rt6 = rt6_ex->rt6i; 1534 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr); 1535 1536 #ifdef CONFIG_IPV6_SUBTREES 1537 if (matched && saddr) 1538 matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr); 1539 #endif 1540 if (matched) 1541 return rt6_ex; 1542 } 1543 return NULL; 1544 } 1545 1546 /* Helper function to find the cached rt in the hash table 1547 * and update bucket pointer to point to the bucket for this 1548 * (daddr, saddr) pair 1549 * Caller must hold rcu_read_lock() 1550 */ 1551 static struct rt6_exception * 1552 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket, 1553 const struct in6_addr *daddr, 1554 const struct in6_addr *saddr) 1555 { 1556 struct rt6_exception *rt6_ex; 1557 u32 hval; 1558 1559 WARN_ON_ONCE(!rcu_read_lock_held()); 1560 1561 if (!(*bucket) || !daddr) 1562 return NULL; 1563 1564 hval = rt6_exception_hash(daddr, saddr); 1565 *bucket += hval; 1566 1567 hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) { 1568 struct rt6_info *rt6 = rt6_ex->rt6i; 1569 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr); 1570 1571 #ifdef CONFIG_IPV6_SUBTREES 1572 if (matched && saddr) 1573 matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr); 1574 #endif 1575 if (matched) 1576 return rt6_ex; 1577 } 1578 return NULL; 1579 } 1580 1581 static unsigned int fib6_mtu(const struct fib6_result *res) 1582 { 1583 const struct fib6_nh *nh = res->nh; 1584 unsigned int mtu; 1585 1586 if (res->f6i->fib6_pmtu) { 1587 mtu = res->f6i->fib6_pmtu; 1588 } else { 1589 struct net_device *dev = nh->fib_nh_dev; 1590 struct inet6_dev *idev; 1591 1592 rcu_read_lock(); 1593 idev = __in6_dev_get(dev); 1594 mtu = idev->cnf.mtu6; 1595 rcu_read_unlock(); 1596 } 1597 1598 mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); 1599 1600 return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu); 1601 } 1602 1603 #define FIB6_EXCEPTION_BUCKET_FLUSHED 0x1UL 1604 1605 /* used when the flushed bit is not relevant, only access to the bucket 1606 * (ie., all bucket users except rt6_insert_exception); 1607 * 1608 * called under rcu lock; sometimes called with rt6_exception_lock held 1609 */ 1610 static 1611 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh, 1612 spinlock_t *lock) 1613 { 1614 struct rt6_exception_bucket *bucket; 1615 1616 if (lock) 1617 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, 1618 lockdep_is_held(lock)); 1619 else 1620 bucket = rcu_dereference(nh->rt6i_exception_bucket); 1621 1622 /* remove bucket flushed bit if set */ 1623 if (bucket) { 1624 unsigned long p = (unsigned long)bucket; 1625 1626 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED; 1627 bucket = (struct rt6_exception_bucket *)p; 1628 } 1629 1630 return bucket; 1631 } 1632 1633 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket) 1634 { 1635 unsigned long p = (unsigned long)bucket; 1636 1637 return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED); 1638 } 1639 1640 /* called with rt6_exception_lock held */ 1641 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh, 1642 spinlock_t *lock) 1643 { 1644 struct rt6_exception_bucket *bucket; 1645 unsigned long p; 1646 1647 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, 1648 lockdep_is_held(lock)); 1649 1650 p = (unsigned long)bucket; 1651 p |= FIB6_EXCEPTION_BUCKET_FLUSHED; 1652 bucket = (struct rt6_exception_bucket *)p; 1653 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket); 1654 } 1655 1656 static int rt6_insert_exception(struct rt6_info *nrt, 1657 const struct fib6_result *res) 1658 { 1659 struct net *net = dev_net(nrt->dst.dev); 1660 struct rt6_exception_bucket *bucket; 1661 struct fib6_info *f6i = res->f6i; 1662 struct in6_addr *src_key = NULL; 1663 struct rt6_exception *rt6_ex; 1664 struct fib6_nh *nh = res->nh; 1665 int max_depth; 1666 int err = 0; 1667 1668 spin_lock_bh(&rt6_exception_lock); 1669 1670 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, 1671 lockdep_is_held(&rt6_exception_lock)); 1672 if (!bucket) { 1673 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket), 1674 GFP_ATOMIC); 1675 if (!bucket) { 1676 err = -ENOMEM; 1677 goto out; 1678 } 1679 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket); 1680 } else if (fib6_nh_excptn_bucket_flushed(bucket)) { 1681 err = -EINVAL; 1682 goto out; 1683 } 1684 1685 #ifdef CONFIG_IPV6_SUBTREES 1686 /* fib6_src.plen != 0 indicates f6i is in subtree 1687 * and exception table is indexed by a hash of 1688 * both fib6_dst and fib6_src. 1689 * Otherwise, the exception table is indexed by 1690 * a hash of only fib6_dst. 1691 */ 1692 if (f6i->fib6_src.plen) 1693 src_key = &nrt->rt6i_src.addr; 1694 #endif 1695 /* rt6_mtu_change() might lower mtu on f6i. 1696 * Only insert this exception route if its mtu 1697 * is less than f6i's mtu value. 1698 */ 1699 if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) { 1700 err = -EINVAL; 1701 goto out; 1702 } 1703 1704 rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr, 1705 src_key); 1706 if (rt6_ex) 1707 rt6_remove_exception(bucket, rt6_ex); 1708 1709 rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC); 1710 if (!rt6_ex) { 1711 err = -ENOMEM; 1712 goto out; 1713 } 1714 rt6_ex->rt6i = nrt; 1715 rt6_ex->stamp = jiffies; 1716 hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain); 1717 bucket->depth++; 1718 net->ipv6.rt6_stats->fib_rt_cache++; 1719 1720 /* Randomize max depth to avoid some side channels attacks. */ 1721 max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH); 1722 while (bucket->depth > max_depth) 1723 rt6_exception_remove_oldest(bucket); 1724 1725 out: 1726 spin_unlock_bh(&rt6_exception_lock); 1727 1728 /* Update fn->fn_sernum to invalidate all cached dst */ 1729 if (!err) { 1730 spin_lock_bh(&f6i->fib6_table->tb6_lock); 1731 fib6_update_sernum(net, f6i); 1732 spin_unlock_bh(&f6i->fib6_table->tb6_lock); 1733 fib6_force_start_gc(net); 1734 } 1735 1736 return err; 1737 } 1738 1739 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from) 1740 { 1741 struct rt6_exception_bucket *bucket; 1742 struct rt6_exception *rt6_ex; 1743 struct hlist_node *tmp; 1744 int i; 1745 1746 spin_lock_bh(&rt6_exception_lock); 1747 1748 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 1749 if (!bucket) 1750 goto out; 1751 1752 /* Prevent rt6_insert_exception() to recreate the bucket list */ 1753 if (!from) 1754 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock); 1755 1756 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 1757 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) { 1758 if (!from || 1759 rcu_access_pointer(rt6_ex->rt6i->from) == from) 1760 rt6_remove_exception(bucket, rt6_ex); 1761 } 1762 WARN_ON_ONCE(!from && bucket->depth); 1763 bucket++; 1764 } 1765 out: 1766 spin_unlock_bh(&rt6_exception_lock); 1767 } 1768 1769 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg) 1770 { 1771 struct fib6_info *f6i = arg; 1772 1773 fib6_nh_flush_exceptions(nh, f6i); 1774 1775 return 0; 1776 } 1777 1778 void rt6_flush_exceptions(struct fib6_info *f6i) 1779 { 1780 if (f6i->nh) 1781 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions, 1782 f6i); 1783 else 1784 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i); 1785 } 1786 1787 /* Find cached rt in the hash table inside passed in rt 1788 * Caller has to hold rcu_read_lock() 1789 */ 1790 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res, 1791 const struct in6_addr *daddr, 1792 const struct in6_addr *saddr) 1793 { 1794 const struct in6_addr *src_key = NULL; 1795 struct rt6_exception_bucket *bucket; 1796 struct rt6_exception *rt6_ex; 1797 struct rt6_info *ret = NULL; 1798 1799 #ifdef CONFIG_IPV6_SUBTREES 1800 /* fib6i_src.plen != 0 indicates f6i is in subtree 1801 * and exception table is indexed by a hash of 1802 * both fib6_dst and fib6_src. 1803 * However, the src addr used to create the hash 1804 * might not be exactly the passed in saddr which 1805 * is a /128 addr from the flow. 1806 * So we need to use f6i->fib6_src to redo lookup 1807 * if the passed in saddr does not find anything. 1808 * (See the logic in ip6_rt_cache_alloc() on how 1809 * rt->rt6i_src is updated.) 1810 */ 1811 if (res->f6i->fib6_src.plen) 1812 src_key = saddr; 1813 find_ex: 1814 #endif 1815 bucket = fib6_nh_get_excptn_bucket(res->nh, NULL); 1816 rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key); 1817 1818 if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i)) 1819 ret = rt6_ex->rt6i; 1820 1821 #ifdef CONFIG_IPV6_SUBTREES 1822 /* Use fib6_src as src_key and redo lookup */ 1823 if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) { 1824 src_key = &res->f6i->fib6_src.addr; 1825 goto find_ex; 1826 } 1827 #endif 1828 1829 return ret; 1830 } 1831 1832 /* Remove the passed in cached rt from the hash table that contains it */ 1833 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen, 1834 const struct rt6_info *rt) 1835 { 1836 const struct in6_addr *src_key = NULL; 1837 struct rt6_exception_bucket *bucket; 1838 struct rt6_exception *rt6_ex; 1839 int err; 1840 1841 if (!rcu_access_pointer(nh->rt6i_exception_bucket)) 1842 return -ENOENT; 1843 1844 spin_lock_bh(&rt6_exception_lock); 1845 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 1846 1847 #ifdef CONFIG_IPV6_SUBTREES 1848 /* rt6i_src.plen != 0 indicates 'from' is in subtree 1849 * and exception table is indexed by a hash of 1850 * both rt6i_dst and rt6i_src. 1851 * Otherwise, the exception table is indexed by 1852 * a hash of only rt6i_dst. 1853 */ 1854 if (plen) 1855 src_key = &rt->rt6i_src.addr; 1856 #endif 1857 rt6_ex = __rt6_find_exception_spinlock(&bucket, 1858 &rt->rt6i_dst.addr, 1859 src_key); 1860 if (rt6_ex) { 1861 rt6_remove_exception(bucket, rt6_ex); 1862 err = 0; 1863 } else { 1864 err = -ENOENT; 1865 } 1866 1867 spin_unlock_bh(&rt6_exception_lock); 1868 return err; 1869 } 1870 1871 struct fib6_nh_excptn_arg { 1872 struct rt6_info *rt; 1873 int plen; 1874 }; 1875 1876 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg) 1877 { 1878 struct fib6_nh_excptn_arg *arg = _arg; 1879 int err; 1880 1881 err = fib6_nh_remove_exception(nh, arg->plen, arg->rt); 1882 if (err == 0) 1883 return 1; 1884 1885 return 0; 1886 } 1887 1888 static int rt6_remove_exception_rt(struct rt6_info *rt) 1889 { 1890 struct fib6_info *from; 1891 1892 from = rcu_dereference(rt->from); 1893 if (!from || !(rt->rt6i_flags & RTF_CACHE)) 1894 return -EINVAL; 1895 1896 if (from->nh) { 1897 struct fib6_nh_excptn_arg arg = { 1898 .rt = rt, 1899 .plen = from->fib6_src.plen 1900 }; 1901 int rc; 1902 1903 /* rc = 1 means an entry was found */ 1904 rc = nexthop_for_each_fib6_nh(from->nh, 1905 rt6_nh_remove_exception_rt, 1906 &arg); 1907 return rc ? 0 : -ENOENT; 1908 } 1909 1910 return fib6_nh_remove_exception(from->fib6_nh, 1911 from->fib6_src.plen, rt); 1912 } 1913 1914 /* Find rt6_ex which contains the passed in rt cache and 1915 * refresh its stamp 1916 */ 1917 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen, 1918 const struct rt6_info *rt) 1919 { 1920 const struct in6_addr *src_key = NULL; 1921 struct rt6_exception_bucket *bucket; 1922 struct rt6_exception *rt6_ex; 1923 1924 bucket = fib6_nh_get_excptn_bucket(nh, NULL); 1925 #ifdef CONFIG_IPV6_SUBTREES 1926 /* rt6i_src.plen != 0 indicates 'from' is in subtree 1927 * and exception table is indexed by a hash of 1928 * both rt6i_dst and rt6i_src. 1929 * Otherwise, the exception table is indexed by 1930 * a hash of only rt6i_dst. 1931 */ 1932 if (plen) 1933 src_key = &rt->rt6i_src.addr; 1934 #endif 1935 rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key); 1936 if (rt6_ex) 1937 rt6_ex->stamp = jiffies; 1938 } 1939 1940 struct fib6_nh_match_arg { 1941 const struct net_device *dev; 1942 const struct in6_addr *gw; 1943 struct fib6_nh *match; 1944 }; 1945 1946 /* determine if fib6_nh has given device and gateway */ 1947 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg) 1948 { 1949 struct fib6_nh_match_arg *arg = _arg; 1950 1951 if (arg->dev != nh->fib_nh_dev || 1952 (arg->gw && !nh->fib_nh_gw_family) || 1953 (!arg->gw && nh->fib_nh_gw_family) || 1954 (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6))) 1955 return 0; 1956 1957 arg->match = nh; 1958 1959 /* found a match, break the loop */ 1960 return 1; 1961 } 1962 1963 static void rt6_update_exception_stamp_rt(struct rt6_info *rt) 1964 { 1965 struct fib6_info *from; 1966 struct fib6_nh *fib6_nh; 1967 1968 rcu_read_lock(); 1969 1970 from = rcu_dereference(rt->from); 1971 if (!from || !(rt->rt6i_flags & RTF_CACHE)) 1972 goto unlock; 1973 1974 if (from->nh) { 1975 struct fib6_nh_match_arg arg = { 1976 .dev = rt->dst.dev, 1977 .gw = &rt->rt6i_gateway, 1978 }; 1979 1980 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg); 1981 1982 if (!arg.match) 1983 goto unlock; 1984 fib6_nh = arg.match; 1985 } else { 1986 fib6_nh = from->fib6_nh; 1987 } 1988 fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt); 1989 unlock: 1990 rcu_read_unlock(); 1991 } 1992 1993 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev, 1994 struct rt6_info *rt, int mtu) 1995 { 1996 /* If the new MTU is lower than the route PMTU, this new MTU will be the 1997 * lowest MTU in the path: always allow updating the route PMTU to 1998 * reflect PMTU decreases. 1999 * 2000 * If the new MTU is higher, and the route PMTU is equal to the local 2001 * MTU, this means the old MTU is the lowest in the path, so allow 2002 * updating it: if other nodes now have lower MTUs, PMTU discovery will 2003 * handle this. 2004 */ 2005 2006 if (dst_mtu(&rt->dst) >= mtu) 2007 return true; 2008 2009 if (dst_mtu(&rt->dst) == idev->cnf.mtu6) 2010 return true; 2011 2012 return false; 2013 } 2014 2015 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev, 2016 const struct fib6_nh *nh, int mtu) 2017 { 2018 struct rt6_exception_bucket *bucket; 2019 struct rt6_exception *rt6_ex; 2020 int i; 2021 2022 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 2023 if (!bucket) 2024 return; 2025 2026 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 2027 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { 2028 struct rt6_info *entry = rt6_ex->rt6i; 2029 2030 /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected 2031 * route), the metrics of its rt->from have already 2032 * been updated. 2033 */ 2034 if (dst_metric_raw(&entry->dst, RTAX_MTU) && 2035 rt6_mtu_change_route_allowed(idev, entry, mtu)) 2036 dst_metric_set(&entry->dst, RTAX_MTU, mtu); 2037 } 2038 bucket++; 2039 } 2040 } 2041 2042 #define RTF_CACHE_GATEWAY (RTF_GATEWAY | RTF_CACHE) 2043 2044 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh, 2045 const struct in6_addr *gateway) 2046 { 2047 struct rt6_exception_bucket *bucket; 2048 struct rt6_exception *rt6_ex; 2049 struct hlist_node *tmp; 2050 int i; 2051 2052 if (!rcu_access_pointer(nh->rt6i_exception_bucket)) 2053 return; 2054 2055 spin_lock_bh(&rt6_exception_lock); 2056 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 2057 if (bucket) { 2058 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 2059 hlist_for_each_entry_safe(rt6_ex, tmp, 2060 &bucket->chain, hlist) { 2061 struct rt6_info *entry = rt6_ex->rt6i; 2062 2063 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) == 2064 RTF_CACHE_GATEWAY && 2065 ipv6_addr_equal(gateway, 2066 &entry->rt6i_gateway)) { 2067 rt6_remove_exception(bucket, rt6_ex); 2068 } 2069 } 2070 bucket++; 2071 } 2072 } 2073 2074 spin_unlock_bh(&rt6_exception_lock); 2075 } 2076 2077 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket, 2078 struct rt6_exception *rt6_ex, 2079 struct fib6_gc_args *gc_args, 2080 unsigned long now) 2081 { 2082 struct rt6_info *rt = rt6_ex->rt6i; 2083 2084 /* we are pruning and obsoleting aged-out and non gateway exceptions 2085 * even if others have still references to them, so that on next 2086 * dst_check() such references can be dropped. 2087 * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when 2088 * expired, independently from their aging, as per RFC 8201 section 4 2089 */ 2090 if (!(rt->rt6i_flags & RTF_EXPIRES)) { 2091 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) { 2092 RT6_TRACE("aging clone %p\n", rt); 2093 rt6_remove_exception(bucket, rt6_ex); 2094 return; 2095 } 2096 } else if (time_after(jiffies, rt->dst.expires)) { 2097 RT6_TRACE("purging expired route %p\n", rt); 2098 rt6_remove_exception(bucket, rt6_ex); 2099 return; 2100 } 2101 2102 if (rt->rt6i_flags & RTF_GATEWAY) { 2103 struct neighbour *neigh; 2104 2105 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); 2106 2107 if (!(neigh && (neigh->flags & NTF_ROUTER))) { 2108 RT6_TRACE("purging route %p via non-router but gateway\n", 2109 rt); 2110 rt6_remove_exception(bucket, rt6_ex); 2111 return; 2112 } 2113 } 2114 2115 gc_args->more++; 2116 } 2117 2118 static void fib6_nh_age_exceptions(const struct fib6_nh *nh, 2119 struct fib6_gc_args *gc_args, 2120 unsigned long now) 2121 { 2122 struct rt6_exception_bucket *bucket; 2123 struct rt6_exception *rt6_ex; 2124 struct hlist_node *tmp; 2125 int i; 2126 2127 if (!rcu_access_pointer(nh->rt6i_exception_bucket)) 2128 return; 2129 2130 rcu_read_lock_bh(); 2131 spin_lock(&rt6_exception_lock); 2132 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 2133 if (bucket) { 2134 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 2135 hlist_for_each_entry_safe(rt6_ex, tmp, 2136 &bucket->chain, hlist) { 2137 rt6_age_examine_exception(bucket, rt6_ex, 2138 gc_args, now); 2139 } 2140 bucket++; 2141 } 2142 } 2143 spin_unlock(&rt6_exception_lock); 2144 rcu_read_unlock_bh(); 2145 } 2146 2147 struct fib6_nh_age_excptn_arg { 2148 struct fib6_gc_args *gc_args; 2149 unsigned long now; 2150 }; 2151 2152 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg) 2153 { 2154 struct fib6_nh_age_excptn_arg *arg = _arg; 2155 2156 fib6_nh_age_exceptions(nh, arg->gc_args, arg->now); 2157 return 0; 2158 } 2159 2160 void rt6_age_exceptions(struct fib6_info *f6i, 2161 struct fib6_gc_args *gc_args, 2162 unsigned long now) 2163 { 2164 if (f6i->nh) { 2165 struct fib6_nh_age_excptn_arg arg = { 2166 .gc_args = gc_args, 2167 .now = now 2168 }; 2169 2170 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions, 2171 &arg); 2172 } else { 2173 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now); 2174 } 2175 } 2176 2177 /* must be called with rcu lock held */ 2178 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif, 2179 struct flowi6 *fl6, struct fib6_result *res, int strict) 2180 { 2181 struct fib6_node *fn, *saved_fn; 2182 2183 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 2184 saved_fn = fn; 2185 2186 redo_rt6_select: 2187 rt6_select(net, fn, oif, res, strict); 2188 if (res->f6i == net->ipv6.fib6_null_entry) { 2189 fn = fib6_backtrack(fn, &fl6->saddr); 2190 if (fn) 2191 goto redo_rt6_select; 2192 else if (strict & RT6_LOOKUP_F_REACHABLE) { 2193 /* also consider unreachable route */ 2194 strict &= ~RT6_LOOKUP_F_REACHABLE; 2195 fn = saved_fn; 2196 goto redo_rt6_select; 2197 } 2198 } 2199 2200 trace_fib6_table_lookup(net, res, table, fl6); 2201 2202 return 0; 2203 } 2204 2205 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 2206 int oif, struct flowi6 *fl6, 2207 const struct sk_buff *skb, int flags) 2208 { 2209 struct fib6_result res = {}; 2210 struct rt6_info *rt = NULL; 2211 int strict = 0; 2212 2213 WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) && 2214 !rcu_read_lock_held()); 2215 2216 strict |= flags & RT6_LOOKUP_F_IFACE; 2217 strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE; 2218 if (net->ipv6.devconf_all->forwarding == 0) 2219 strict |= RT6_LOOKUP_F_REACHABLE; 2220 2221 rcu_read_lock(); 2222 2223 fib6_table_lookup(net, table, oif, fl6, &res, strict); 2224 if (res.f6i == net->ipv6.fib6_null_entry) 2225 goto out; 2226 2227 fib6_select_path(net, &res, fl6, oif, false, skb, strict); 2228 2229 /*Search through exception table */ 2230 rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr); 2231 if (rt) { 2232 goto out; 2233 } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) && 2234 !res.nh->fib_nh_gw_family)) { 2235 /* Create a RTF_CACHE clone which will not be 2236 * owned by the fib6 tree. It is for the special case where 2237 * the daddr in the skb during the neighbor look-up is different 2238 * from the fl6->daddr used to look-up route here. 2239 */ 2240 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL); 2241 2242 if (rt) { 2243 /* 1 refcnt is taken during ip6_rt_cache_alloc(). 2244 * As rt6_uncached_list_add() does not consume refcnt, 2245 * this refcnt is always returned to the caller even 2246 * if caller sets RT6_LOOKUP_F_DST_NOREF flag. 2247 */ 2248 rt6_uncached_list_add(rt); 2249 rcu_read_unlock(); 2250 2251 return rt; 2252 } 2253 } else { 2254 /* Get a percpu copy */ 2255 local_bh_disable(); 2256 rt = rt6_get_pcpu_route(&res); 2257 2258 if (!rt) 2259 rt = rt6_make_pcpu_route(net, &res); 2260 2261 local_bh_enable(); 2262 } 2263 out: 2264 if (!rt) 2265 rt = net->ipv6.ip6_null_entry; 2266 if (!(flags & RT6_LOOKUP_F_DST_NOREF)) 2267 ip6_hold_safe(net, &rt); 2268 rcu_read_unlock(); 2269 2270 return rt; 2271 } 2272 EXPORT_SYMBOL_GPL(ip6_pol_route); 2273 2274 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net, 2275 struct fib6_table *table, 2276 struct flowi6 *fl6, 2277 const struct sk_buff *skb, 2278 int flags) 2279 { 2280 return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags); 2281 } 2282 2283 struct dst_entry *ip6_route_input_lookup(struct net *net, 2284 struct net_device *dev, 2285 struct flowi6 *fl6, 2286 const struct sk_buff *skb, 2287 int flags) 2288 { 2289 if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG) 2290 flags |= RT6_LOOKUP_F_IFACE; 2291 2292 return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input); 2293 } 2294 EXPORT_SYMBOL_GPL(ip6_route_input_lookup); 2295 2296 static void ip6_multipath_l3_keys(const struct sk_buff *skb, 2297 struct flow_keys *keys, 2298 struct flow_keys *flkeys) 2299 { 2300 const struct ipv6hdr *outer_iph = ipv6_hdr(skb); 2301 const struct ipv6hdr *key_iph = outer_iph; 2302 struct flow_keys *_flkeys = flkeys; 2303 const struct ipv6hdr *inner_iph; 2304 const struct icmp6hdr *icmph; 2305 struct ipv6hdr _inner_iph; 2306 struct icmp6hdr _icmph; 2307 2308 if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6)) 2309 goto out; 2310 2311 icmph = skb_header_pointer(skb, skb_transport_offset(skb), 2312 sizeof(_icmph), &_icmph); 2313 if (!icmph) 2314 goto out; 2315 2316 if (!icmpv6_is_err(icmph->icmp6_type)) 2317 goto out; 2318 2319 inner_iph = skb_header_pointer(skb, 2320 skb_transport_offset(skb) + sizeof(*icmph), 2321 sizeof(_inner_iph), &_inner_iph); 2322 if (!inner_iph) 2323 goto out; 2324 2325 key_iph = inner_iph; 2326 _flkeys = NULL; 2327 out: 2328 if (_flkeys) { 2329 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src; 2330 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst; 2331 keys->tags.flow_label = _flkeys->tags.flow_label; 2332 keys->basic.ip_proto = _flkeys->basic.ip_proto; 2333 } else { 2334 keys->addrs.v6addrs.src = key_iph->saddr; 2335 keys->addrs.v6addrs.dst = key_iph->daddr; 2336 keys->tags.flow_label = ip6_flowlabel(key_iph); 2337 keys->basic.ip_proto = key_iph->nexthdr; 2338 } 2339 } 2340 2341 static u32 rt6_multipath_custom_hash_outer(const struct net *net, 2342 const struct sk_buff *skb, 2343 bool *p_has_inner) 2344 { 2345 u32 hash_fields = ip6_multipath_hash_fields(net); 2346 struct flow_keys keys, hash_keys; 2347 2348 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2349 return 0; 2350 2351 memset(&hash_keys, 0, sizeof(hash_keys)); 2352 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 2353 2354 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2355 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2356 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2357 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2358 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2359 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2360 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2361 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL) 2362 hash_keys.tags.flow_label = keys.tags.flow_label; 2363 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2364 hash_keys.ports.src = keys.ports.src; 2365 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2366 hash_keys.ports.dst = keys.ports.dst; 2367 2368 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 2369 return flow_hash_from_keys(&hash_keys); 2370 } 2371 2372 static u32 rt6_multipath_custom_hash_inner(const struct net *net, 2373 const struct sk_buff *skb, 2374 bool has_inner) 2375 { 2376 u32 hash_fields = ip6_multipath_hash_fields(net); 2377 struct flow_keys keys, hash_keys; 2378 2379 /* We assume the packet carries an encapsulation, but if none was 2380 * encountered during dissection of the outer flow, then there is no 2381 * point in calling the flow dissector again. 2382 */ 2383 if (!has_inner) 2384 return 0; 2385 2386 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 2387 return 0; 2388 2389 memset(&hash_keys, 0, sizeof(hash_keys)); 2390 skb_flow_dissect_flow_keys(skb, &keys, 0); 2391 2392 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 2393 return 0; 2394 2395 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2396 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2397 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2398 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2399 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2400 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2401 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2402 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2403 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2404 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2405 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2406 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2407 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2408 hash_keys.tags.flow_label = keys.tags.flow_label; 2409 } 2410 2411 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2412 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2413 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2414 hash_keys.ports.src = keys.ports.src; 2415 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2416 hash_keys.ports.dst = keys.ports.dst; 2417 2418 return flow_hash_from_keys(&hash_keys); 2419 } 2420 2421 static u32 rt6_multipath_custom_hash_skb(const struct net *net, 2422 const struct sk_buff *skb) 2423 { 2424 u32 mhash, mhash_inner; 2425 bool has_inner = true; 2426 2427 mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner); 2428 mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner); 2429 2430 return jhash_2words(mhash, mhash_inner, 0); 2431 } 2432 2433 static u32 rt6_multipath_custom_hash_fl6(const struct net *net, 2434 const struct flowi6 *fl6) 2435 { 2436 u32 hash_fields = ip6_multipath_hash_fields(net); 2437 struct flow_keys hash_keys; 2438 2439 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2440 return 0; 2441 2442 memset(&hash_keys, 0, sizeof(hash_keys)); 2443 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2444 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2445 hash_keys.addrs.v6addrs.src = fl6->saddr; 2446 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2447 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2448 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2449 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2450 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL) 2451 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 2452 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2453 hash_keys.ports.src = fl6->fl6_sport; 2454 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2455 hash_keys.ports.dst = fl6->fl6_dport; 2456 2457 return flow_hash_from_keys(&hash_keys); 2458 } 2459 2460 /* if skb is set it will be used and fl6 can be NULL */ 2461 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 2462 const struct sk_buff *skb, struct flow_keys *flkeys) 2463 { 2464 struct flow_keys hash_keys; 2465 u32 mhash = 0; 2466 2467 switch (ip6_multipath_hash_policy(net)) { 2468 case 0: 2469 memset(&hash_keys, 0, sizeof(hash_keys)); 2470 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2471 if (skb) { 2472 ip6_multipath_l3_keys(skb, &hash_keys, flkeys); 2473 } else { 2474 hash_keys.addrs.v6addrs.src = fl6->saddr; 2475 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2476 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 2477 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2478 } 2479 mhash = flow_hash_from_keys(&hash_keys); 2480 break; 2481 case 1: 2482 if (skb) { 2483 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2484 struct flow_keys keys; 2485 2486 /* short-circuit if we already have L4 hash present */ 2487 if (skb->l4_hash) 2488 return skb_get_hash_raw(skb) >> 1; 2489 2490 memset(&hash_keys, 0, sizeof(hash_keys)); 2491 2492 if (!flkeys) { 2493 skb_flow_dissect_flow_keys(skb, &keys, flag); 2494 flkeys = &keys; 2495 } 2496 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2497 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src; 2498 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst; 2499 hash_keys.ports.src = flkeys->ports.src; 2500 hash_keys.ports.dst = flkeys->ports.dst; 2501 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2502 } else { 2503 memset(&hash_keys, 0, sizeof(hash_keys)); 2504 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2505 hash_keys.addrs.v6addrs.src = fl6->saddr; 2506 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2507 hash_keys.ports.src = fl6->fl6_sport; 2508 hash_keys.ports.dst = fl6->fl6_dport; 2509 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2510 } 2511 mhash = flow_hash_from_keys(&hash_keys); 2512 break; 2513 case 2: 2514 memset(&hash_keys, 0, sizeof(hash_keys)); 2515 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2516 if (skb) { 2517 struct flow_keys keys; 2518 2519 if (!flkeys) { 2520 skb_flow_dissect_flow_keys(skb, &keys, 0); 2521 flkeys = &keys; 2522 } 2523 2524 /* Inner can be v4 or v6 */ 2525 if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2526 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2527 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2528 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2529 } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2530 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2531 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src; 2532 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst; 2533 hash_keys.tags.flow_label = flkeys->tags.flow_label; 2534 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2535 } else { 2536 /* Same as case 0 */ 2537 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2538 ip6_multipath_l3_keys(skb, &hash_keys, flkeys); 2539 } 2540 } else { 2541 /* Same as case 0 */ 2542 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2543 hash_keys.addrs.v6addrs.src = fl6->saddr; 2544 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2545 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 2546 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2547 } 2548 mhash = flow_hash_from_keys(&hash_keys); 2549 break; 2550 case 3: 2551 if (skb) 2552 mhash = rt6_multipath_custom_hash_skb(net, skb); 2553 else 2554 mhash = rt6_multipath_custom_hash_fl6(net, fl6); 2555 break; 2556 } 2557 2558 return mhash >> 1; 2559 } 2560 2561 /* Called with rcu held */ 2562 void ip6_route_input(struct sk_buff *skb) 2563 { 2564 const struct ipv6hdr *iph = ipv6_hdr(skb); 2565 struct net *net = dev_net(skb->dev); 2566 int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF; 2567 struct ip_tunnel_info *tun_info; 2568 struct flowi6 fl6 = { 2569 .flowi6_iif = skb->dev->ifindex, 2570 .daddr = iph->daddr, 2571 .saddr = iph->saddr, 2572 .flowlabel = ip6_flowinfo(iph), 2573 .flowi6_mark = skb->mark, 2574 .flowi6_proto = iph->nexthdr, 2575 }; 2576 struct flow_keys *flkeys = NULL, _flkeys; 2577 2578 tun_info = skb_tunnel_info(skb); 2579 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2580 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id; 2581 2582 if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys)) 2583 flkeys = &_flkeys; 2584 2585 if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6)) 2586 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys); 2587 skb_dst_drop(skb); 2588 skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev, 2589 &fl6, skb, flags)); 2590 } 2591 2592 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net, 2593 struct fib6_table *table, 2594 struct flowi6 *fl6, 2595 const struct sk_buff *skb, 2596 int flags) 2597 { 2598 return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags); 2599 } 2600 2601 static struct dst_entry *ip6_route_output_flags_noref(struct net *net, 2602 const struct sock *sk, 2603 struct flowi6 *fl6, 2604 int flags) 2605 { 2606 bool any_src; 2607 2608 if (ipv6_addr_type(&fl6->daddr) & 2609 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) { 2610 struct dst_entry *dst; 2611 2612 /* This function does not take refcnt on the dst */ 2613 dst = l3mdev_link_scope_lookup(net, fl6); 2614 if (dst) 2615 return dst; 2616 } 2617 2618 fl6->flowi6_iif = LOOPBACK_IFINDEX; 2619 2620 flags |= RT6_LOOKUP_F_DST_NOREF; 2621 any_src = ipv6_addr_any(&fl6->saddr); 2622 if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) || 2623 (fl6->flowi6_oif && any_src)) 2624 flags |= RT6_LOOKUP_F_IFACE; 2625 2626 if (!any_src) 2627 flags |= RT6_LOOKUP_F_HAS_SADDR; 2628 else if (sk) 2629 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs); 2630 2631 return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output); 2632 } 2633 2634 struct dst_entry *ip6_route_output_flags(struct net *net, 2635 const struct sock *sk, 2636 struct flowi6 *fl6, 2637 int flags) 2638 { 2639 struct dst_entry *dst; 2640 struct rt6_info *rt6; 2641 2642 rcu_read_lock(); 2643 dst = ip6_route_output_flags_noref(net, sk, fl6, flags); 2644 rt6 = (struct rt6_info *)dst; 2645 /* For dst cached in uncached_list, refcnt is already taken. */ 2646 if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) { 2647 dst = &net->ipv6.ip6_null_entry->dst; 2648 dst_hold(dst); 2649 } 2650 rcu_read_unlock(); 2651 2652 return dst; 2653 } 2654 EXPORT_SYMBOL_GPL(ip6_route_output_flags); 2655 2656 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2657 { 2658 struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig; 2659 struct net_device *loopback_dev = net->loopback_dev; 2660 struct dst_entry *new = NULL; 2661 2662 rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1, 2663 DST_OBSOLETE_DEAD, 0); 2664 if (rt) { 2665 rt6_info_init(rt); 2666 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc); 2667 2668 new = &rt->dst; 2669 new->__use = 1; 2670 new->input = dst_discard; 2671 new->output = dst_discard_out; 2672 2673 dst_copy_metrics(new, &ort->dst); 2674 2675 rt->rt6i_idev = in6_dev_get(loopback_dev); 2676 rt->rt6i_gateway = ort->rt6i_gateway; 2677 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU; 2678 2679 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); 2680 #ifdef CONFIG_IPV6_SUBTREES 2681 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 2682 #endif 2683 } 2684 2685 dst_release(dst_orig); 2686 return new ? new : ERR_PTR(-ENOMEM); 2687 } 2688 2689 /* 2690 * Destination cache support functions 2691 */ 2692 2693 static bool fib6_check(struct fib6_info *f6i, u32 cookie) 2694 { 2695 u32 rt_cookie = 0; 2696 2697 if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie) 2698 return false; 2699 2700 if (fib6_check_expired(f6i)) 2701 return false; 2702 2703 return true; 2704 } 2705 2706 static struct dst_entry *rt6_check(struct rt6_info *rt, 2707 struct fib6_info *from, 2708 u32 cookie) 2709 { 2710 u32 rt_cookie = 0; 2711 2712 if (!from || !fib6_get_cookie_safe(from, &rt_cookie) || 2713 rt_cookie != cookie) 2714 return NULL; 2715 2716 if (rt6_check_expired(rt)) 2717 return NULL; 2718 2719 return &rt->dst; 2720 } 2721 2722 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, 2723 struct fib6_info *from, 2724 u32 cookie) 2725 { 2726 if (!__rt6_check_expired(rt) && 2727 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 2728 fib6_check(from, cookie)) 2729 return &rt->dst; 2730 else 2731 return NULL; 2732 } 2733 2734 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst, 2735 u32 cookie) 2736 { 2737 struct dst_entry *dst_ret; 2738 struct fib6_info *from; 2739 struct rt6_info *rt; 2740 2741 rt = container_of(dst, struct rt6_info, dst); 2742 2743 if (rt->sernum) 2744 return rt6_is_valid(rt) ? dst : NULL; 2745 2746 rcu_read_lock(); 2747 2748 /* All IPV6 dsts are created with ->obsolete set to the value 2749 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 2750 * into this function always. 2751 */ 2752 2753 from = rcu_dereference(rt->from); 2754 2755 if (from && (rt->rt6i_flags & RTF_PCPU || 2756 unlikely(!list_empty(&rt->dst.rt_uncached)))) 2757 dst_ret = rt6_dst_from_check(rt, from, cookie); 2758 else 2759 dst_ret = rt6_check(rt, from, cookie); 2760 2761 rcu_read_unlock(); 2762 2763 return dst_ret; 2764 } 2765 EXPORT_INDIRECT_CALLABLE(ip6_dst_check); 2766 2767 static void ip6_negative_advice(struct sock *sk, 2768 struct dst_entry *dst) 2769 { 2770 struct rt6_info *rt = (struct rt6_info *) dst; 2771 2772 if (rt->rt6i_flags & RTF_CACHE) { 2773 rcu_read_lock(); 2774 if (rt6_check_expired(rt)) { 2775 /* counteract the dst_release() in sk_dst_reset() */ 2776 dst_hold(dst); 2777 sk_dst_reset(sk); 2778 2779 rt6_remove_exception_rt(rt); 2780 } 2781 rcu_read_unlock(); 2782 return; 2783 } 2784 sk_dst_reset(sk); 2785 } 2786 2787 static void ip6_link_failure(struct sk_buff *skb) 2788 { 2789 struct rt6_info *rt; 2790 2791 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); 2792 2793 rt = (struct rt6_info *) skb_dst(skb); 2794 if (rt) { 2795 rcu_read_lock(); 2796 if (rt->rt6i_flags & RTF_CACHE) { 2797 rt6_remove_exception_rt(rt); 2798 } else { 2799 struct fib6_info *from; 2800 struct fib6_node *fn; 2801 2802 from = rcu_dereference(rt->from); 2803 if (from) { 2804 fn = rcu_dereference(from->fib6_node); 2805 if (fn && (rt->rt6i_flags & RTF_DEFAULT)) 2806 WRITE_ONCE(fn->fn_sernum, -1); 2807 } 2808 } 2809 rcu_read_unlock(); 2810 } 2811 } 2812 2813 static void rt6_update_expires(struct rt6_info *rt0, int timeout) 2814 { 2815 if (!(rt0->rt6i_flags & RTF_EXPIRES)) { 2816 struct fib6_info *from; 2817 2818 rcu_read_lock(); 2819 from = rcu_dereference(rt0->from); 2820 if (from) 2821 rt0->dst.expires = from->expires; 2822 rcu_read_unlock(); 2823 } 2824 2825 dst_set_expires(&rt0->dst, timeout); 2826 rt0->rt6i_flags |= RTF_EXPIRES; 2827 } 2828 2829 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu) 2830 { 2831 struct net *net = dev_net(rt->dst.dev); 2832 2833 dst_metric_set(&rt->dst, RTAX_MTU, mtu); 2834 rt->rt6i_flags |= RTF_MODIFIED; 2835 rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires); 2836 } 2837 2838 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt) 2839 { 2840 return !(rt->rt6i_flags & RTF_CACHE) && 2841 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from)); 2842 } 2843 2844 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk, 2845 const struct ipv6hdr *iph, u32 mtu, 2846 bool confirm_neigh) 2847 { 2848 const struct in6_addr *daddr, *saddr; 2849 struct rt6_info *rt6 = (struct rt6_info *)dst; 2850 2851 /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU) 2852 * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it. 2853 * [see also comment in rt6_mtu_change_route()] 2854 */ 2855 2856 if (iph) { 2857 daddr = &iph->daddr; 2858 saddr = &iph->saddr; 2859 } else if (sk) { 2860 daddr = &sk->sk_v6_daddr; 2861 saddr = &inet6_sk(sk)->saddr; 2862 } else { 2863 daddr = NULL; 2864 saddr = NULL; 2865 } 2866 2867 if (confirm_neigh) 2868 dst_confirm_neigh(dst, daddr); 2869 2870 if (mtu < IPV6_MIN_MTU) 2871 return; 2872 if (mtu >= dst_mtu(dst)) 2873 return; 2874 2875 if (!rt6_cache_allowed_for_pmtu(rt6)) { 2876 rt6_do_update_pmtu(rt6, mtu); 2877 /* update rt6_ex->stamp for cache */ 2878 if (rt6->rt6i_flags & RTF_CACHE) 2879 rt6_update_exception_stamp_rt(rt6); 2880 } else if (daddr) { 2881 struct fib6_result res = {}; 2882 struct rt6_info *nrt6; 2883 2884 rcu_read_lock(); 2885 res.f6i = rcu_dereference(rt6->from); 2886 if (!res.f6i) 2887 goto out_unlock; 2888 2889 res.fib6_flags = res.f6i->fib6_flags; 2890 res.fib6_type = res.f6i->fib6_type; 2891 2892 if (res.f6i->nh) { 2893 struct fib6_nh_match_arg arg = { 2894 .dev = dst->dev, 2895 .gw = &rt6->rt6i_gateway, 2896 }; 2897 2898 nexthop_for_each_fib6_nh(res.f6i->nh, 2899 fib6_nh_find_match, &arg); 2900 2901 /* fib6_info uses a nexthop that does not have fib6_nh 2902 * using the dst->dev + gw. Should be impossible. 2903 */ 2904 if (!arg.match) 2905 goto out_unlock; 2906 2907 res.nh = arg.match; 2908 } else { 2909 res.nh = res.f6i->fib6_nh; 2910 } 2911 2912 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr); 2913 if (nrt6) { 2914 rt6_do_update_pmtu(nrt6, mtu); 2915 if (rt6_insert_exception(nrt6, &res)) 2916 dst_release_immediate(&nrt6->dst); 2917 } 2918 out_unlock: 2919 rcu_read_unlock(); 2920 } 2921 } 2922 2923 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 2924 struct sk_buff *skb, u32 mtu, 2925 bool confirm_neigh) 2926 { 2927 __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu, 2928 confirm_neigh); 2929 } 2930 2931 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, 2932 int oif, u32 mark, kuid_t uid) 2933 { 2934 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; 2935 struct dst_entry *dst; 2936 struct flowi6 fl6 = { 2937 .flowi6_oif = oif, 2938 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark), 2939 .daddr = iph->daddr, 2940 .saddr = iph->saddr, 2941 .flowlabel = ip6_flowinfo(iph), 2942 .flowi6_uid = uid, 2943 }; 2944 2945 dst = ip6_route_output(net, NULL, &fl6); 2946 if (!dst->error) 2947 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true); 2948 dst_release(dst); 2949 } 2950 EXPORT_SYMBOL_GPL(ip6_update_pmtu); 2951 2952 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu) 2953 { 2954 int oif = sk->sk_bound_dev_if; 2955 struct dst_entry *dst; 2956 2957 if (!oif && skb->dev) 2958 oif = l3mdev_master_ifindex(skb->dev); 2959 2960 ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark), 2961 sk->sk_uid); 2962 2963 dst = __sk_dst_get(sk); 2964 if (!dst || !dst->obsolete || 2965 dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) 2966 return; 2967 2968 bh_lock_sock(sk); 2969 if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) 2970 ip6_datagram_dst_update(sk, false); 2971 bh_unlock_sock(sk); 2972 } 2973 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu); 2974 2975 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 2976 const struct flowi6 *fl6) 2977 { 2978 #ifdef CONFIG_IPV6_SUBTREES 2979 struct ipv6_pinfo *np = inet6_sk(sk); 2980 #endif 2981 2982 ip6_dst_store(sk, dst, 2983 ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ? 2984 &sk->sk_v6_daddr : NULL, 2985 #ifdef CONFIG_IPV6_SUBTREES 2986 ipv6_addr_equal(&fl6->saddr, &np->saddr) ? 2987 &np->saddr : 2988 #endif 2989 NULL); 2990 } 2991 2992 static bool ip6_redirect_nh_match(const struct fib6_result *res, 2993 struct flowi6 *fl6, 2994 const struct in6_addr *gw, 2995 struct rt6_info **ret) 2996 { 2997 const struct fib6_nh *nh = res->nh; 2998 2999 if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family || 3000 fl6->flowi6_oif != nh->fib_nh_dev->ifindex) 3001 return false; 3002 3003 /* rt_cache's gateway might be different from its 'parent' 3004 * in the case of an ip redirect. 3005 * So we keep searching in the exception table if the gateway 3006 * is different. 3007 */ 3008 if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) { 3009 struct rt6_info *rt_cache; 3010 3011 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr); 3012 if (rt_cache && 3013 ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) { 3014 *ret = rt_cache; 3015 return true; 3016 } 3017 return false; 3018 } 3019 return true; 3020 } 3021 3022 struct fib6_nh_rd_arg { 3023 struct fib6_result *res; 3024 struct flowi6 *fl6; 3025 const struct in6_addr *gw; 3026 struct rt6_info **ret; 3027 }; 3028 3029 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg) 3030 { 3031 struct fib6_nh_rd_arg *arg = _arg; 3032 3033 arg->res->nh = nh; 3034 return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret); 3035 } 3036 3037 /* Handle redirects */ 3038 struct ip6rd_flowi { 3039 struct flowi6 fl6; 3040 struct in6_addr gateway; 3041 }; 3042 3043 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net, 3044 struct fib6_table *table, 3045 struct flowi6 *fl6, 3046 const struct sk_buff *skb, 3047 int flags) 3048 { 3049 struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6; 3050 struct rt6_info *ret = NULL; 3051 struct fib6_result res = {}; 3052 struct fib6_nh_rd_arg arg = { 3053 .res = &res, 3054 .fl6 = fl6, 3055 .gw = &rdfl->gateway, 3056 .ret = &ret 3057 }; 3058 struct fib6_info *rt; 3059 struct fib6_node *fn; 3060 3061 /* Get the "current" route for this destination and 3062 * check if the redirect has come from appropriate router. 3063 * 3064 * RFC 4861 specifies that redirects should only be 3065 * accepted if they come from the nexthop to the target. 3066 * Due to the way the routes are chosen, this notion 3067 * is a bit fuzzy and one might need to check all possible 3068 * routes. 3069 */ 3070 3071 rcu_read_lock(); 3072 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 3073 restart: 3074 for_each_fib6_node_rt_rcu(fn) { 3075 res.f6i = rt; 3076 if (fib6_check_expired(rt)) 3077 continue; 3078 if (rt->fib6_flags & RTF_REJECT) 3079 break; 3080 if (unlikely(rt->nh)) { 3081 if (nexthop_is_blackhole(rt->nh)) 3082 continue; 3083 /* on match, res->nh is filled in and potentially ret */ 3084 if (nexthop_for_each_fib6_nh(rt->nh, 3085 fib6_nh_redirect_match, 3086 &arg)) 3087 goto out; 3088 } else { 3089 res.nh = rt->fib6_nh; 3090 if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway, 3091 &ret)) 3092 goto out; 3093 } 3094 } 3095 3096 if (!rt) 3097 rt = net->ipv6.fib6_null_entry; 3098 else if (rt->fib6_flags & RTF_REJECT) { 3099 ret = net->ipv6.ip6_null_entry; 3100 goto out; 3101 } 3102 3103 if (rt == net->ipv6.fib6_null_entry) { 3104 fn = fib6_backtrack(fn, &fl6->saddr); 3105 if (fn) 3106 goto restart; 3107 } 3108 3109 res.f6i = rt; 3110 res.nh = rt->fib6_nh; 3111 out: 3112 if (ret) { 3113 ip6_hold_safe(net, &ret); 3114 } else { 3115 res.fib6_flags = res.f6i->fib6_flags; 3116 res.fib6_type = res.f6i->fib6_type; 3117 ret = ip6_create_rt_rcu(&res); 3118 } 3119 3120 rcu_read_unlock(); 3121 3122 trace_fib6_table_lookup(net, &res, table, fl6); 3123 return ret; 3124 }; 3125 3126 static struct dst_entry *ip6_route_redirect(struct net *net, 3127 const struct flowi6 *fl6, 3128 const struct sk_buff *skb, 3129 const struct in6_addr *gateway) 3130 { 3131 int flags = RT6_LOOKUP_F_HAS_SADDR; 3132 struct ip6rd_flowi rdfl; 3133 3134 rdfl.fl6 = *fl6; 3135 rdfl.gateway = *gateway; 3136 3137 return fib6_rule_lookup(net, &rdfl.fl6, skb, 3138 flags, __ip6_route_redirect); 3139 } 3140 3141 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 3142 kuid_t uid) 3143 { 3144 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; 3145 struct dst_entry *dst; 3146 struct flowi6 fl6 = { 3147 .flowi6_iif = LOOPBACK_IFINDEX, 3148 .flowi6_oif = oif, 3149 .flowi6_mark = mark, 3150 .daddr = iph->daddr, 3151 .saddr = iph->saddr, 3152 .flowlabel = ip6_flowinfo(iph), 3153 .flowi6_uid = uid, 3154 }; 3155 3156 dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr); 3157 rt6_do_redirect(dst, NULL, skb); 3158 dst_release(dst); 3159 } 3160 EXPORT_SYMBOL_GPL(ip6_redirect); 3161 3162 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif) 3163 { 3164 const struct ipv6hdr *iph = ipv6_hdr(skb); 3165 const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb); 3166 struct dst_entry *dst; 3167 struct flowi6 fl6 = { 3168 .flowi6_iif = LOOPBACK_IFINDEX, 3169 .flowi6_oif = oif, 3170 .daddr = msg->dest, 3171 .saddr = iph->daddr, 3172 .flowi6_uid = sock_net_uid(net, NULL), 3173 }; 3174 3175 dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr); 3176 rt6_do_redirect(dst, NULL, skb); 3177 dst_release(dst); 3178 } 3179 3180 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk) 3181 { 3182 ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, 3183 READ_ONCE(sk->sk_mark), sk->sk_uid); 3184 } 3185 EXPORT_SYMBOL_GPL(ip6_sk_redirect); 3186 3187 static unsigned int ip6_default_advmss(const struct dst_entry *dst) 3188 { 3189 struct net_device *dev = dst->dev; 3190 unsigned int mtu = dst_mtu(dst); 3191 struct net *net = dev_net(dev); 3192 3193 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); 3194 3195 if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss) 3196 mtu = net->ipv6.sysctl.ip6_rt_min_advmss; 3197 3198 /* 3199 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and 3200 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. 3201 * IPV6_MAXPLEN is also valid and means: "any MSS, 3202 * rely only on pmtu discovery" 3203 */ 3204 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) 3205 mtu = IPV6_MAXPLEN; 3206 return mtu; 3207 } 3208 3209 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst) 3210 { 3211 return ip6_dst_mtu_maybe_forward(dst, false); 3212 } 3213 EXPORT_INDIRECT_CALLABLE(ip6_mtu); 3214 3215 /* MTU selection: 3216 * 1. mtu on route is locked - use it 3217 * 2. mtu from nexthop exception 3218 * 3. mtu from egress device 3219 * 3220 * based on ip6_dst_mtu_forward and exception logic of 3221 * rt6_find_cached_rt; called with rcu_read_lock 3222 */ 3223 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 3224 const struct in6_addr *daddr, 3225 const struct in6_addr *saddr) 3226 { 3227 const struct fib6_nh *nh = res->nh; 3228 struct fib6_info *f6i = res->f6i; 3229 struct inet6_dev *idev; 3230 struct rt6_info *rt; 3231 u32 mtu = 0; 3232 3233 if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) { 3234 mtu = f6i->fib6_pmtu; 3235 if (mtu) 3236 goto out; 3237 } 3238 3239 rt = rt6_find_cached_rt(res, daddr, saddr); 3240 if (unlikely(rt)) { 3241 mtu = dst_metric_raw(&rt->dst, RTAX_MTU); 3242 } else { 3243 struct net_device *dev = nh->fib_nh_dev; 3244 3245 mtu = IPV6_MIN_MTU; 3246 idev = __in6_dev_get(dev); 3247 if (idev && idev->cnf.mtu6 > mtu) 3248 mtu = idev->cnf.mtu6; 3249 } 3250 3251 mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); 3252 out: 3253 return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu); 3254 } 3255 3256 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, 3257 struct flowi6 *fl6) 3258 { 3259 struct dst_entry *dst; 3260 struct rt6_info *rt; 3261 struct inet6_dev *idev = in6_dev_get(dev); 3262 struct net *net = dev_net(dev); 3263 3264 if (unlikely(!idev)) 3265 return ERR_PTR(-ENODEV); 3266 3267 rt = ip6_dst_alloc(net, dev, 0); 3268 if (unlikely(!rt)) { 3269 in6_dev_put(idev); 3270 dst = ERR_PTR(-ENOMEM); 3271 goto out; 3272 } 3273 3274 rt->dst.input = ip6_input; 3275 rt->dst.output = ip6_output; 3276 rt->rt6i_gateway = fl6->daddr; 3277 rt->rt6i_dst.addr = fl6->daddr; 3278 rt->rt6i_dst.plen = 128; 3279 rt->rt6i_idev = idev; 3280 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0); 3281 3282 /* Add this dst into uncached_list so that rt6_disable_ip() can 3283 * do proper release of the net_device 3284 */ 3285 rt6_uncached_list_add(rt); 3286 3287 dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0); 3288 3289 out: 3290 return dst; 3291 } 3292 3293 static void ip6_dst_gc(struct dst_ops *ops) 3294 { 3295 struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops); 3296 int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval; 3297 int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity; 3298 int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout; 3299 unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc; 3300 unsigned int val; 3301 int entries; 3302 3303 if (time_after(rt_last_gc + rt_min_interval, jiffies)) 3304 goto out; 3305 3306 fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true); 3307 entries = dst_entries_get_slow(ops); 3308 if (entries < ops->gc_thresh) 3309 atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1); 3310 out: 3311 val = atomic_read(&net->ipv6.ip6_rt_gc_expire); 3312 atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity)); 3313 } 3314 3315 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg, 3316 const struct in6_addr *gw_addr, u32 tbid, 3317 int flags, struct fib6_result *res) 3318 { 3319 struct flowi6 fl6 = { 3320 .flowi6_oif = cfg->fc_ifindex, 3321 .daddr = *gw_addr, 3322 .saddr = cfg->fc_prefsrc, 3323 }; 3324 struct fib6_table *table; 3325 int err; 3326 3327 table = fib6_get_table(net, tbid); 3328 if (!table) 3329 return -EINVAL; 3330 3331 if (!ipv6_addr_any(&cfg->fc_prefsrc)) 3332 flags |= RT6_LOOKUP_F_HAS_SADDR; 3333 3334 flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE; 3335 3336 err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags); 3337 if (!err && res->f6i != net->ipv6.fib6_null_entry) 3338 fib6_select_path(net, res, &fl6, cfg->fc_ifindex, 3339 cfg->fc_ifindex != 0, NULL, flags); 3340 3341 return err; 3342 } 3343 3344 static int ip6_route_check_nh_onlink(struct net *net, 3345 struct fib6_config *cfg, 3346 const struct net_device *dev, 3347 struct netlink_ext_ack *extack) 3348 { 3349 u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; 3350 const struct in6_addr *gw_addr = &cfg->fc_gateway; 3351 struct fib6_result res = {}; 3352 int err; 3353 3354 err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res); 3355 if (!err && !(res.fib6_flags & RTF_REJECT) && 3356 /* ignore match if it is the default route */ 3357 !ipv6_addr_any(&res.f6i->fib6_dst.addr) && 3358 (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) { 3359 NL_SET_ERR_MSG(extack, 3360 "Nexthop has invalid gateway or device mismatch"); 3361 err = -EINVAL; 3362 } 3363 3364 return err; 3365 } 3366 3367 static int ip6_route_check_nh(struct net *net, 3368 struct fib6_config *cfg, 3369 struct net_device **_dev, 3370 netdevice_tracker *dev_tracker, 3371 struct inet6_dev **idev) 3372 { 3373 const struct in6_addr *gw_addr = &cfg->fc_gateway; 3374 struct net_device *dev = _dev ? *_dev : NULL; 3375 int flags = RT6_LOOKUP_F_IFACE; 3376 struct fib6_result res = {}; 3377 int err = -EHOSTUNREACH; 3378 3379 if (cfg->fc_table) { 3380 err = ip6_nh_lookup_table(net, cfg, gw_addr, 3381 cfg->fc_table, flags, &res); 3382 /* gw_addr can not require a gateway or resolve to a reject 3383 * route. If a device is given, it must match the result. 3384 */ 3385 if (err || res.fib6_flags & RTF_REJECT || 3386 res.nh->fib_nh_gw_family || 3387 (dev && dev != res.nh->fib_nh_dev)) 3388 err = -EHOSTUNREACH; 3389 } 3390 3391 if (err < 0) { 3392 struct flowi6 fl6 = { 3393 .flowi6_oif = cfg->fc_ifindex, 3394 .daddr = *gw_addr, 3395 }; 3396 3397 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags); 3398 if (err || res.fib6_flags & RTF_REJECT || 3399 res.nh->fib_nh_gw_family) 3400 err = -EHOSTUNREACH; 3401 3402 if (err) 3403 return err; 3404 3405 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex, 3406 cfg->fc_ifindex != 0, NULL, flags); 3407 } 3408 3409 err = 0; 3410 if (dev) { 3411 if (dev != res.nh->fib_nh_dev) 3412 err = -EHOSTUNREACH; 3413 } else { 3414 *_dev = dev = res.nh->fib_nh_dev; 3415 netdev_hold(dev, dev_tracker, GFP_ATOMIC); 3416 *idev = in6_dev_get(dev); 3417 } 3418 3419 return err; 3420 } 3421 3422 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg, 3423 struct net_device **_dev, 3424 netdevice_tracker *dev_tracker, 3425 struct inet6_dev **idev, 3426 struct netlink_ext_ack *extack) 3427 { 3428 const struct in6_addr *gw_addr = &cfg->fc_gateway; 3429 int gwa_type = ipv6_addr_type(gw_addr); 3430 bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true; 3431 const struct net_device *dev = *_dev; 3432 bool need_addr_check = !dev; 3433 int err = -EINVAL; 3434 3435 /* if gw_addr is local we will fail to detect this in case 3436 * address is still TENTATIVE (DAD in progress). rt6_lookup() 3437 * will return already-added prefix route via interface that 3438 * prefix route was assigned to, which might be non-loopback. 3439 */ 3440 if (dev && 3441 ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) { 3442 NL_SET_ERR_MSG(extack, "Gateway can not be a local address"); 3443 goto out; 3444 } 3445 3446 if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) { 3447 /* IPv6 strictly inhibits using not link-local 3448 * addresses as nexthop address. 3449 * Otherwise, router will not able to send redirects. 3450 * It is very good, but in some (rare!) circumstances 3451 * (SIT, PtP, NBMA NOARP links) it is handy to allow 3452 * some exceptions. --ANK 3453 * We allow IPv4-mapped nexthops to support RFC4798-type 3454 * addressing 3455 */ 3456 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) { 3457 NL_SET_ERR_MSG(extack, "Invalid gateway address"); 3458 goto out; 3459 } 3460 3461 rcu_read_lock(); 3462 3463 if (cfg->fc_flags & RTNH_F_ONLINK) 3464 err = ip6_route_check_nh_onlink(net, cfg, dev, extack); 3465 else 3466 err = ip6_route_check_nh(net, cfg, _dev, dev_tracker, 3467 idev); 3468 3469 rcu_read_unlock(); 3470 3471 if (err) 3472 goto out; 3473 } 3474 3475 /* reload in case device was changed */ 3476 dev = *_dev; 3477 3478 err = -EINVAL; 3479 if (!dev) { 3480 NL_SET_ERR_MSG(extack, "Egress device not specified"); 3481 goto out; 3482 } else if (dev->flags & IFF_LOOPBACK) { 3483 NL_SET_ERR_MSG(extack, 3484 "Egress device can not be loopback device for this route"); 3485 goto out; 3486 } 3487 3488 /* if we did not check gw_addr above, do so now that the 3489 * egress device has been resolved. 3490 */ 3491 if (need_addr_check && 3492 ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) { 3493 NL_SET_ERR_MSG(extack, "Gateway can not be a local address"); 3494 goto out; 3495 } 3496 3497 err = 0; 3498 out: 3499 return err; 3500 } 3501 3502 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type) 3503 { 3504 if ((flags & RTF_REJECT) || 3505 (dev && (dev->flags & IFF_LOOPBACK) && 3506 !(addr_type & IPV6_ADDR_LOOPBACK) && 3507 !(flags & (RTF_ANYCAST | RTF_LOCAL)))) 3508 return true; 3509 3510 return false; 3511 } 3512 3513 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 3514 struct fib6_config *cfg, gfp_t gfp_flags, 3515 struct netlink_ext_ack *extack) 3516 { 3517 netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker; 3518 struct net_device *dev = NULL; 3519 struct inet6_dev *idev = NULL; 3520 int addr_type; 3521 int err; 3522 3523 fib6_nh->fib_nh_family = AF_INET6; 3524 #ifdef CONFIG_IPV6_ROUTER_PREF 3525 fib6_nh->last_probe = jiffies; 3526 #endif 3527 if (cfg->fc_is_fdb) { 3528 fib6_nh->fib_nh_gw6 = cfg->fc_gateway; 3529 fib6_nh->fib_nh_gw_family = AF_INET6; 3530 return 0; 3531 } 3532 3533 err = -ENODEV; 3534 if (cfg->fc_ifindex) { 3535 dev = netdev_get_by_index(net, cfg->fc_ifindex, 3536 dev_tracker, gfp_flags); 3537 if (!dev) 3538 goto out; 3539 idev = in6_dev_get(dev); 3540 if (!idev) 3541 goto out; 3542 } 3543 3544 if (cfg->fc_flags & RTNH_F_ONLINK) { 3545 if (!dev) { 3546 NL_SET_ERR_MSG(extack, 3547 "Nexthop device required for onlink"); 3548 goto out; 3549 } 3550 3551 if (!(dev->flags & IFF_UP)) { 3552 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 3553 err = -ENETDOWN; 3554 goto out; 3555 } 3556 3557 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK; 3558 } 3559 3560 fib6_nh->fib_nh_weight = 1; 3561 3562 /* We cannot add true routes via loopback here, 3563 * they would result in kernel looping; promote them to reject routes 3564 */ 3565 addr_type = ipv6_addr_type(&cfg->fc_dst); 3566 if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) { 3567 /* hold loopback dev/idev if we haven't done so. */ 3568 if (dev != net->loopback_dev) { 3569 if (dev) { 3570 netdev_put(dev, dev_tracker); 3571 in6_dev_put(idev); 3572 } 3573 dev = net->loopback_dev; 3574 netdev_hold(dev, dev_tracker, gfp_flags); 3575 idev = in6_dev_get(dev); 3576 if (!idev) { 3577 err = -ENODEV; 3578 goto out; 3579 } 3580 } 3581 goto pcpu_alloc; 3582 } 3583 3584 if (cfg->fc_flags & RTF_GATEWAY) { 3585 err = ip6_validate_gw(net, cfg, &dev, dev_tracker, 3586 &idev, extack); 3587 if (err) 3588 goto out; 3589 3590 fib6_nh->fib_nh_gw6 = cfg->fc_gateway; 3591 fib6_nh->fib_nh_gw_family = AF_INET6; 3592 } 3593 3594 err = -ENODEV; 3595 if (!dev) 3596 goto out; 3597 3598 if (!idev || idev->cnf.disable_ipv6) { 3599 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device"); 3600 err = -EACCES; 3601 goto out; 3602 } 3603 3604 if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) { 3605 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 3606 err = -ENETDOWN; 3607 goto out; 3608 } 3609 3610 if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) && 3611 !netif_carrier_ok(dev)) 3612 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN; 3613 3614 err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap, 3615 cfg->fc_encap_type, cfg, gfp_flags, extack); 3616 if (err) 3617 goto out; 3618 3619 pcpu_alloc: 3620 fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); 3621 if (!fib6_nh->rt6i_pcpu) { 3622 err = -ENOMEM; 3623 goto out; 3624 } 3625 3626 fib6_nh->fib_nh_dev = dev; 3627 fib6_nh->fib_nh_oif = dev->ifindex; 3628 err = 0; 3629 out: 3630 if (idev) 3631 in6_dev_put(idev); 3632 3633 if (err) { 3634 lwtstate_put(fib6_nh->fib_nh_lws); 3635 fib6_nh->fib_nh_lws = NULL; 3636 netdev_put(dev, dev_tracker); 3637 } 3638 3639 return err; 3640 } 3641 3642 void fib6_nh_release(struct fib6_nh *fib6_nh) 3643 { 3644 struct rt6_exception_bucket *bucket; 3645 3646 rcu_read_lock(); 3647 3648 fib6_nh_flush_exceptions(fib6_nh, NULL); 3649 bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL); 3650 if (bucket) { 3651 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL); 3652 kfree(bucket); 3653 } 3654 3655 rcu_read_unlock(); 3656 3657 fib6_nh_release_dsts(fib6_nh); 3658 free_percpu(fib6_nh->rt6i_pcpu); 3659 3660 fib_nh_common_release(&fib6_nh->nh_common); 3661 } 3662 3663 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh) 3664 { 3665 int cpu; 3666 3667 if (!fib6_nh->rt6i_pcpu) 3668 return; 3669 3670 for_each_possible_cpu(cpu) { 3671 struct rt6_info *pcpu_rt, **ppcpu_rt; 3672 3673 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); 3674 pcpu_rt = xchg(ppcpu_rt, NULL); 3675 if (pcpu_rt) { 3676 dst_dev_put(&pcpu_rt->dst); 3677 dst_release(&pcpu_rt->dst); 3678 } 3679 } 3680 } 3681 3682 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, 3683 gfp_t gfp_flags, 3684 struct netlink_ext_ack *extack) 3685 { 3686 struct net *net = cfg->fc_nlinfo.nl_net; 3687 struct fib6_info *rt = NULL; 3688 struct nexthop *nh = NULL; 3689 struct fib6_table *table; 3690 struct fib6_nh *fib6_nh; 3691 int err = -EINVAL; 3692 int addr_type; 3693 3694 /* RTF_PCPU is an internal flag; can not be set by userspace */ 3695 if (cfg->fc_flags & RTF_PCPU) { 3696 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU"); 3697 goto out; 3698 } 3699 3700 /* RTF_CACHE is an internal flag; can not be set by userspace */ 3701 if (cfg->fc_flags & RTF_CACHE) { 3702 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE"); 3703 goto out; 3704 } 3705 3706 if (cfg->fc_type > RTN_MAX) { 3707 NL_SET_ERR_MSG(extack, "Invalid route type"); 3708 goto out; 3709 } 3710 3711 if (cfg->fc_dst_len > 128) { 3712 NL_SET_ERR_MSG(extack, "Invalid prefix length"); 3713 goto out; 3714 } 3715 if (cfg->fc_src_len > 128) { 3716 NL_SET_ERR_MSG(extack, "Invalid source address length"); 3717 goto out; 3718 } 3719 #ifndef CONFIG_IPV6_SUBTREES 3720 if (cfg->fc_src_len) { 3721 NL_SET_ERR_MSG(extack, 3722 "Specifying source address requires IPV6_SUBTREES to be enabled"); 3723 goto out; 3724 } 3725 #endif 3726 if (cfg->fc_nh_id) { 3727 nh = nexthop_find_by_id(net, cfg->fc_nh_id); 3728 if (!nh) { 3729 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 3730 goto out; 3731 } 3732 err = fib6_check_nexthop(nh, cfg, extack); 3733 if (err) 3734 goto out; 3735 } 3736 3737 err = -ENOBUFS; 3738 if (cfg->fc_nlinfo.nlh && 3739 !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) { 3740 table = fib6_get_table(net, cfg->fc_table); 3741 if (!table) { 3742 pr_warn("NLM_F_CREATE should be specified when creating new route\n"); 3743 table = fib6_new_table(net, cfg->fc_table); 3744 } 3745 } else { 3746 table = fib6_new_table(net, cfg->fc_table); 3747 } 3748 3749 if (!table) 3750 goto out; 3751 3752 err = -ENOMEM; 3753 rt = fib6_info_alloc(gfp_flags, !nh); 3754 if (!rt) 3755 goto out; 3756 3757 rt->fib6_metrics = ip_fib_metrics_init(cfg->fc_mx, cfg->fc_mx_len, 3758 extack); 3759 if (IS_ERR(rt->fib6_metrics)) { 3760 err = PTR_ERR(rt->fib6_metrics); 3761 /* Do not leave garbage there. */ 3762 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics; 3763 goto out_free; 3764 } 3765 3766 if (cfg->fc_flags & RTF_ADDRCONF) 3767 rt->dst_nocount = true; 3768 3769 if (cfg->fc_flags & RTF_EXPIRES) 3770 fib6_set_expires(rt, jiffies + 3771 clock_t_to_jiffies(cfg->fc_expires)); 3772 else 3773 fib6_clean_expires(rt); 3774 3775 if (cfg->fc_protocol == RTPROT_UNSPEC) 3776 cfg->fc_protocol = RTPROT_BOOT; 3777 rt->fib6_protocol = cfg->fc_protocol; 3778 3779 rt->fib6_table = table; 3780 rt->fib6_metric = cfg->fc_metric; 3781 rt->fib6_type = cfg->fc_type ? : RTN_UNICAST; 3782 rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY; 3783 3784 ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len); 3785 rt->fib6_dst.plen = cfg->fc_dst_len; 3786 3787 #ifdef CONFIG_IPV6_SUBTREES 3788 ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len); 3789 rt->fib6_src.plen = cfg->fc_src_len; 3790 #endif 3791 if (nh) { 3792 if (rt->fib6_src.plen) { 3793 NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing"); 3794 goto out_free; 3795 } 3796 if (!nexthop_get(nh)) { 3797 NL_SET_ERR_MSG(extack, "Nexthop has been deleted"); 3798 goto out_free; 3799 } 3800 rt->nh = nh; 3801 fib6_nh = nexthop_fib6_nh(rt->nh); 3802 } else { 3803 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack); 3804 if (err) 3805 goto out; 3806 3807 fib6_nh = rt->fib6_nh; 3808 3809 /* We cannot add true routes via loopback here, they would 3810 * result in kernel looping; promote them to reject routes 3811 */ 3812 addr_type = ipv6_addr_type(&cfg->fc_dst); 3813 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev, 3814 addr_type)) 3815 rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP; 3816 } 3817 3818 if (!ipv6_addr_any(&cfg->fc_prefsrc)) { 3819 struct net_device *dev = fib6_nh->fib_nh_dev; 3820 3821 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) { 3822 NL_SET_ERR_MSG(extack, "Invalid source address"); 3823 err = -EINVAL; 3824 goto out; 3825 } 3826 rt->fib6_prefsrc.addr = cfg->fc_prefsrc; 3827 rt->fib6_prefsrc.plen = 128; 3828 } else 3829 rt->fib6_prefsrc.plen = 0; 3830 3831 return rt; 3832 out: 3833 fib6_info_release(rt); 3834 return ERR_PTR(err); 3835 out_free: 3836 ip_fib_metrics_put(rt->fib6_metrics); 3837 kfree(rt); 3838 return ERR_PTR(err); 3839 } 3840 3841 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 3842 struct netlink_ext_ack *extack) 3843 { 3844 struct fib6_info *rt; 3845 int err; 3846 3847 rt = ip6_route_info_create(cfg, gfp_flags, extack); 3848 if (IS_ERR(rt)) 3849 return PTR_ERR(rt); 3850 3851 err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack); 3852 fib6_info_release(rt); 3853 3854 return err; 3855 } 3856 3857 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info) 3858 { 3859 struct net *net = info->nl_net; 3860 struct fib6_table *table; 3861 int err; 3862 3863 if (rt == net->ipv6.fib6_null_entry) { 3864 err = -ENOENT; 3865 goto out; 3866 } 3867 3868 table = rt->fib6_table; 3869 spin_lock_bh(&table->tb6_lock); 3870 err = fib6_del(rt, info); 3871 spin_unlock_bh(&table->tb6_lock); 3872 3873 out: 3874 fib6_info_release(rt); 3875 return err; 3876 } 3877 3878 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify) 3879 { 3880 struct nl_info info = { 3881 .nl_net = net, 3882 .skip_notify = skip_notify 3883 }; 3884 3885 return __ip6_del_rt(rt, &info); 3886 } 3887 3888 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg) 3889 { 3890 struct nl_info *info = &cfg->fc_nlinfo; 3891 struct net *net = info->nl_net; 3892 struct sk_buff *skb = NULL; 3893 struct fib6_table *table; 3894 int err = -ENOENT; 3895 3896 if (rt == net->ipv6.fib6_null_entry) 3897 goto out_put; 3898 table = rt->fib6_table; 3899 spin_lock_bh(&table->tb6_lock); 3900 3901 if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) { 3902 struct fib6_info *sibling, *next_sibling; 3903 struct fib6_node *fn; 3904 3905 /* prefer to send a single notification with all hops */ 3906 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); 3907 if (skb) { 3908 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 3909 3910 if (rt6_fill_node(net, skb, rt, NULL, 3911 NULL, NULL, 0, RTM_DELROUTE, 3912 info->portid, seq, 0) < 0) { 3913 kfree_skb(skb); 3914 skb = NULL; 3915 } else 3916 info->skip_notify = 1; 3917 } 3918 3919 /* 'rt' points to the first sibling route. If it is not the 3920 * leaf, then we do not need to send a notification. Otherwise, 3921 * we need to check if the last sibling has a next route or not 3922 * and emit a replace or delete notification, respectively. 3923 */ 3924 info->skip_notify_kernel = 1; 3925 fn = rcu_dereference_protected(rt->fib6_node, 3926 lockdep_is_held(&table->tb6_lock)); 3927 if (rcu_access_pointer(fn->leaf) == rt) { 3928 struct fib6_info *last_sibling, *replace_rt; 3929 3930 last_sibling = list_last_entry(&rt->fib6_siblings, 3931 struct fib6_info, 3932 fib6_siblings); 3933 replace_rt = rcu_dereference_protected( 3934 last_sibling->fib6_next, 3935 lockdep_is_held(&table->tb6_lock)); 3936 if (replace_rt) 3937 call_fib6_entry_notifiers_replace(net, 3938 replace_rt); 3939 else 3940 call_fib6_multipath_entry_notifiers(net, 3941 FIB_EVENT_ENTRY_DEL, 3942 rt, rt->fib6_nsiblings, 3943 NULL); 3944 } 3945 list_for_each_entry_safe(sibling, next_sibling, 3946 &rt->fib6_siblings, 3947 fib6_siblings) { 3948 err = fib6_del(sibling, info); 3949 if (err) 3950 goto out_unlock; 3951 } 3952 } 3953 3954 err = fib6_del(rt, info); 3955 out_unlock: 3956 spin_unlock_bh(&table->tb6_lock); 3957 out_put: 3958 fib6_info_release(rt); 3959 3960 if (skb) { 3961 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, 3962 info->nlh, gfp_any()); 3963 } 3964 return err; 3965 } 3966 3967 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg) 3968 { 3969 int rc = -ESRCH; 3970 3971 if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex) 3972 goto out; 3973 3974 if (cfg->fc_flags & RTF_GATEWAY && 3975 !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway)) 3976 goto out; 3977 3978 rc = rt6_remove_exception_rt(rt); 3979 out: 3980 return rc; 3981 } 3982 3983 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt, 3984 struct fib6_nh *nh) 3985 { 3986 struct fib6_result res = { 3987 .f6i = rt, 3988 .nh = nh, 3989 }; 3990 struct rt6_info *rt_cache; 3991 3992 rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src); 3993 if (rt_cache) 3994 return __ip6_del_cached_rt(rt_cache, cfg); 3995 3996 return 0; 3997 } 3998 3999 struct fib6_nh_del_cached_rt_arg { 4000 struct fib6_config *cfg; 4001 struct fib6_info *f6i; 4002 }; 4003 4004 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg) 4005 { 4006 struct fib6_nh_del_cached_rt_arg *arg = _arg; 4007 int rc; 4008 4009 rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh); 4010 return rc != -ESRCH ? rc : 0; 4011 } 4012 4013 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i) 4014 { 4015 struct fib6_nh_del_cached_rt_arg arg = { 4016 .cfg = cfg, 4017 .f6i = f6i 4018 }; 4019 4020 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg); 4021 } 4022 4023 static int ip6_route_del(struct fib6_config *cfg, 4024 struct netlink_ext_ack *extack) 4025 { 4026 struct fib6_table *table; 4027 struct fib6_info *rt; 4028 struct fib6_node *fn; 4029 int err = -ESRCH; 4030 4031 table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table); 4032 if (!table) { 4033 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 4034 return err; 4035 } 4036 4037 rcu_read_lock(); 4038 4039 fn = fib6_locate(&table->tb6_root, 4040 &cfg->fc_dst, cfg->fc_dst_len, 4041 &cfg->fc_src, cfg->fc_src_len, 4042 !(cfg->fc_flags & RTF_CACHE)); 4043 4044 if (fn) { 4045 for_each_fib6_node_rt_rcu(fn) { 4046 struct fib6_nh *nh; 4047 4048 if (rt->nh && cfg->fc_nh_id && 4049 rt->nh->id != cfg->fc_nh_id) 4050 continue; 4051 4052 if (cfg->fc_flags & RTF_CACHE) { 4053 int rc = 0; 4054 4055 if (rt->nh) { 4056 rc = ip6_del_cached_rt_nh(cfg, rt); 4057 } else if (cfg->fc_nh_id) { 4058 continue; 4059 } else { 4060 nh = rt->fib6_nh; 4061 rc = ip6_del_cached_rt(cfg, rt, nh); 4062 } 4063 if (rc != -ESRCH) { 4064 rcu_read_unlock(); 4065 return rc; 4066 } 4067 continue; 4068 } 4069 4070 if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric) 4071 continue; 4072 if (cfg->fc_protocol && 4073 cfg->fc_protocol != rt->fib6_protocol) 4074 continue; 4075 4076 if (rt->nh) { 4077 if (!fib6_info_hold_safe(rt)) 4078 continue; 4079 rcu_read_unlock(); 4080 4081 return __ip6_del_rt(rt, &cfg->fc_nlinfo); 4082 } 4083 if (cfg->fc_nh_id) 4084 continue; 4085 4086 nh = rt->fib6_nh; 4087 if (cfg->fc_ifindex && 4088 (!nh->fib_nh_dev || 4089 nh->fib_nh_dev->ifindex != cfg->fc_ifindex)) 4090 continue; 4091 if (cfg->fc_flags & RTF_GATEWAY && 4092 !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6)) 4093 continue; 4094 if (!fib6_info_hold_safe(rt)) 4095 continue; 4096 rcu_read_unlock(); 4097 4098 /* if gateway was specified only delete the one hop */ 4099 if (cfg->fc_flags & RTF_GATEWAY) 4100 return __ip6_del_rt(rt, &cfg->fc_nlinfo); 4101 4102 return __ip6_del_rt_siblings(rt, cfg); 4103 } 4104 } 4105 rcu_read_unlock(); 4106 4107 return err; 4108 } 4109 4110 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 4111 { 4112 struct netevent_redirect netevent; 4113 struct rt6_info *rt, *nrt = NULL; 4114 struct fib6_result res = {}; 4115 struct ndisc_options ndopts; 4116 struct inet6_dev *in6_dev; 4117 struct neighbour *neigh; 4118 struct rd_msg *msg; 4119 int optlen, on_link; 4120 u8 *lladdr; 4121 4122 optlen = skb_tail_pointer(skb) - skb_transport_header(skb); 4123 optlen -= sizeof(*msg); 4124 4125 if (optlen < 0) { 4126 net_dbg_ratelimited("rt6_do_redirect: packet too short\n"); 4127 return; 4128 } 4129 4130 msg = (struct rd_msg *)icmp6_hdr(skb); 4131 4132 if (ipv6_addr_is_multicast(&msg->dest)) { 4133 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n"); 4134 return; 4135 } 4136 4137 on_link = 0; 4138 if (ipv6_addr_equal(&msg->dest, &msg->target)) { 4139 on_link = 1; 4140 } else if (ipv6_addr_type(&msg->target) != 4141 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 4142 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n"); 4143 return; 4144 } 4145 4146 in6_dev = __in6_dev_get(skb->dev); 4147 if (!in6_dev) 4148 return; 4149 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) 4150 return; 4151 4152 /* RFC2461 8.1: 4153 * The IP source address of the Redirect MUST be the same as the current 4154 * first-hop router for the specified ICMP Destination Address. 4155 */ 4156 4157 if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) { 4158 net_dbg_ratelimited("rt6_redirect: invalid ND options\n"); 4159 return; 4160 } 4161 4162 lladdr = NULL; 4163 if (ndopts.nd_opts_tgt_lladdr) { 4164 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, 4165 skb->dev); 4166 if (!lladdr) { 4167 net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n"); 4168 return; 4169 } 4170 } 4171 4172 rt = (struct rt6_info *) dst; 4173 if (rt->rt6i_flags & RTF_REJECT) { 4174 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n"); 4175 return; 4176 } 4177 4178 /* Redirect received -> path was valid. 4179 * Look, redirects are sent only in response to data packets, 4180 * so that this nexthop apparently is reachable. --ANK 4181 */ 4182 dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr); 4183 4184 neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1); 4185 if (!neigh) 4186 return; 4187 4188 /* 4189 * We have finally decided to accept it. 4190 */ 4191 4192 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 4193 NEIGH_UPDATE_F_WEAK_OVERRIDE| 4194 NEIGH_UPDATE_F_OVERRIDE| 4195 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 4196 NEIGH_UPDATE_F_ISROUTER)), 4197 NDISC_REDIRECT, &ndopts); 4198 4199 rcu_read_lock(); 4200 res.f6i = rcu_dereference(rt->from); 4201 if (!res.f6i) 4202 goto out; 4203 4204 if (res.f6i->nh) { 4205 struct fib6_nh_match_arg arg = { 4206 .dev = dst->dev, 4207 .gw = &rt->rt6i_gateway, 4208 }; 4209 4210 nexthop_for_each_fib6_nh(res.f6i->nh, 4211 fib6_nh_find_match, &arg); 4212 4213 /* fib6_info uses a nexthop that does not have fib6_nh 4214 * using the dst->dev. Should be impossible 4215 */ 4216 if (!arg.match) 4217 goto out; 4218 res.nh = arg.match; 4219 } else { 4220 res.nh = res.f6i->fib6_nh; 4221 } 4222 4223 res.fib6_flags = res.f6i->fib6_flags; 4224 res.fib6_type = res.f6i->fib6_type; 4225 nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL); 4226 if (!nrt) 4227 goto out; 4228 4229 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; 4230 if (on_link) 4231 nrt->rt6i_flags &= ~RTF_GATEWAY; 4232 4233 nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key; 4234 4235 /* rt6_insert_exception() will take care of duplicated exceptions */ 4236 if (rt6_insert_exception(nrt, &res)) { 4237 dst_release_immediate(&nrt->dst); 4238 goto out; 4239 } 4240 4241 netevent.old = &rt->dst; 4242 netevent.new = &nrt->dst; 4243 netevent.daddr = &msg->dest; 4244 netevent.neigh = neigh; 4245 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent); 4246 4247 out: 4248 rcu_read_unlock(); 4249 neigh_release(neigh); 4250 } 4251 4252 #ifdef CONFIG_IPV6_ROUTE_INFO 4253 static struct fib6_info *rt6_get_route_info(struct net *net, 4254 const struct in6_addr *prefix, int prefixlen, 4255 const struct in6_addr *gwaddr, 4256 struct net_device *dev) 4257 { 4258 u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO; 4259 int ifindex = dev->ifindex; 4260 struct fib6_node *fn; 4261 struct fib6_info *rt = NULL; 4262 struct fib6_table *table; 4263 4264 table = fib6_get_table(net, tb_id); 4265 if (!table) 4266 return NULL; 4267 4268 rcu_read_lock(); 4269 fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true); 4270 if (!fn) 4271 goto out; 4272 4273 for_each_fib6_node_rt_rcu(fn) { 4274 /* these routes do not use nexthops */ 4275 if (rt->nh) 4276 continue; 4277 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex) 4278 continue; 4279 if (!(rt->fib6_flags & RTF_ROUTEINFO) || 4280 !rt->fib6_nh->fib_nh_gw_family) 4281 continue; 4282 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr)) 4283 continue; 4284 if (!fib6_info_hold_safe(rt)) 4285 continue; 4286 break; 4287 } 4288 out: 4289 rcu_read_unlock(); 4290 return rt; 4291 } 4292 4293 static struct fib6_info *rt6_add_route_info(struct net *net, 4294 const struct in6_addr *prefix, int prefixlen, 4295 const struct in6_addr *gwaddr, 4296 struct net_device *dev, 4297 unsigned int pref) 4298 { 4299 struct fib6_config cfg = { 4300 .fc_metric = IP6_RT_PRIO_USER, 4301 .fc_ifindex = dev->ifindex, 4302 .fc_dst_len = prefixlen, 4303 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | 4304 RTF_UP | RTF_PREF(pref), 4305 .fc_protocol = RTPROT_RA, 4306 .fc_type = RTN_UNICAST, 4307 .fc_nlinfo.portid = 0, 4308 .fc_nlinfo.nlh = NULL, 4309 .fc_nlinfo.nl_net = net, 4310 }; 4311 4312 cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO; 4313 cfg.fc_dst = *prefix; 4314 cfg.fc_gateway = *gwaddr; 4315 4316 /* We should treat it as a default route if prefix length is 0. */ 4317 if (!prefixlen) 4318 cfg.fc_flags |= RTF_DEFAULT; 4319 4320 ip6_route_add(&cfg, GFP_ATOMIC, NULL); 4321 4322 return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev); 4323 } 4324 #endif 4325 4326 struct fib6_info *rt6_get_dflt_router(struct net *net, 4327 const struct in6_addr *addr, 4328 struct net_device *dev) 4329 { 4330 u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT; 4331 struct fib6_info *rt; 4332 struct fib6_table *table; 4333 4334 table = fib6_get_table(net, tb_id); 4335 if (!table) 4336 return NULL; 4337 4338 rcu_read_lock(); 4339 for_each_fib6_node_rt_rcu(&table->tb6_root) { 4340 struct fib6_nh *nh; 4341 4342 /* RA routes do not use nexthops */ 4343 if (rt->nh) 4344 continue; 4345 4346 nh = rt->fib6_nh; 4347 if (dev == nh->fib_nh_dev && 4348 ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && 4349 ipv6_addr_equal(&nh->fib_nh_gw6, addr)) 4350 break; 4351 } 4352 if (rt && !fib6_info_hold_safe(rt)) 4353 rt = NULL; 4354 rcu_read_unlock(); 4355 return rt; 4356 } 4357 4358 struct fib6_info *rt6_add_dflt_router(struct net *net, 4359 const struct in6_addr *gwaddr, 4360 struct net_device *dev, 4361 unsigned int pref, 4362 u32 defrtr_usr_metric) 4363 { 4364 struct fib6_config cfg = { 4365 .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT, 4366 .fc_metric = defrtr_usr_metric, 4367 .fc_ifindex = dev->ifindex, 4368 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | 4369 RTF_UP | RTF_EXPIRES | RTF_PREF(pref), 4370 .fc_protocol = RTPROT_RA, 4371 .fc_type = RTN_UNICAST, 4372 .fc_nlinfo.portid = 0, 4373 .fc_nlinfo.nlh = NULL, 4374 .fc_nlinfo.nl_net = net, 4375 }; 4376 4377 cfg.fc_gateway = *gwaddr; 4378 4379 if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) { 4380 struct fib6_table *table; 4381 4382 table = fib6_get_table(dev_net(dev), cfg.fc_table); 4383 if (table) 4384 table->flags |= RT6_TABLE_HAS_DFLT_ROUTER; 4385 } 4386 4387 return rt6_get_dflt_router(net, gwaddr, dev); 4388 } 4389 4390 static void __rt6_purge_dflt_routers(struct net *net, 4391 struct fib6_table *table) 4392 { 4393 struct fib6_info *rt; 4394 4395 restart: 4396 rcu_read_lock(); 4397 for_each_fib6_node_rt_rcu(&table->tb6_root) { 4398 struct net_device *dev = fib6_info_nh_dev(rt); 4399 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL; 4400 4401 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) && 4402 (!idev || idev->cnf.accept_ra != 2) && 4403 fib6_info_hold_safe(rt)) { 4404 rcu_read_unlock(); 4405 ip6_del_rt(net, rt, false); 4406 goto restart; 4407 } 4408 } 4409 rcu_read_unlock(); 4410 4411 table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER; 4412 } 4413 4414 void rt6_purge_dflt_routers(struct net *net) 4415 { 4416 struct fib6_table *table; 4417 struct hlist_head *head; 4418 unsigned int h; 4419 4420 rcu_read_lock(); 4421 4422 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 4423 head = &net->ipv6.fib_table_hash[h]; 4424 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 4425 if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER) 4426 __rt6_purge_dflt_routers(net, table); 4427 } 4428 } 4429 4430 rcu_read_unlock(); 4431 } 4432 4433 static void rtmsg_to_fib6_config(struct net *net, 4434 struct in6_rtmsg *rtmsg, 4435 struct fib6_config *cfg) 4436 { 4437 *cfg = (struct fib6_config){ 4438 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ? 4439 : RT6_TABLE_MAIN, 4440 .fc_ifindex = rtmsg->rtmsg_ifindex, 4441 .fc_metric = rtmsg->rtmsg_metric, 4442 .fc_expires = rtmsg->rtmsg_info, 4443 .fc_dst_len = rtmsg->rtmsg_dst_len, 4444 .fc_src_len = rtmsg->rtmsg_src_len, 4445 .fc_flags = rtmsg->rtmsg_flags, 4446 .fc_type = rtmsg->rtmsg_type, 4447 4448 .fc_nlinfo.nl_net = net, 4449 4450 .fc_dst = rtmsg->rtmsg_dst, 4451 .fc_src = rtmsg->rtmsg_src, 4452 .fc_gateway = rtmsg->rtmsg_gateway, 4453 }; 4454 } 4455 4456 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg) 4457 { 4458 struct fib6_config cfg; 4459 int err; 4460 4461 if (cmd != SIOCADDRT && cmd != SIOCDELRT) 4462 return -EINVAL; 4463 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 4464 return -EPERM; 4465 4466 rtmsg_to_fib6_config(net, rtmsg, &cfg); 4467 4468 rtnl_lock(); 4469 switch (cmd) { 4470 case SIOCADDRT: 4471 /* Only do the default setting of fc_metric in route adding */ 4472 if (cfg.fc_metric == 0) 4473 cfg.fc_metric = IP6_RT_PRIO_USER; 4474 err = ip6_route_add(&cfg, GFP_KERNEL, NULL); 4475 break; 4476 case SIOCDELRT: 4477 err = ip6_route_del(&cfg, NULL); 4478 break; 4479 } 4480 rtnl_unlock(); 4481 return err; 4482 } 4483 4484 /* 4485 * Drop the packet on the floor 4486 */ 4487 4488 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes) 4489 { 4490 struct dst_entry *dst = skb_dst(skb); 4491 struct net *net = dev_net(dst->dev); 4492 struct inet6_dev *idev; 4493 SKB_DR(reason); 4494 int type; 4495 4496 if (netif_is_l3_master(skb->dev) || 4497 dst->dev == net->loopback_dev) 4498 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); 4499 else 4500 idev = ip6_dst_idev(dst); 4501 4502 switch (ipstats_mib_noroutes) { 4503 case IPSTATS_MIB_INNOROUTES: 4504 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr); 4505 if (type == IPV6_ADDR_ANY) { 4506 SKB_DR_SET(reason, IP_INADDRERRORS); 4507 IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 4508 break; 4509 } 4510 SKB_DR_SET(reason, IP_INNOROUTES); 4511 fallthrough; 4512 case IPSTATS_MIB_OUTNOROUTES: 4513 SKB_DR_OR(reason, IP_OUTNOROUTES); 4514 IP6_INC_STATS(net, idev, ipstats_mib_noroutes); 4515 break; 4516 } 4517 4518 /* Start over by dropping the dst for l3mdev case */ 4519 if (netif_is_l3_master(skb->dev)) 4520 skb_dst_drop(skb); 4521 4522 icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0); 4523 kfree_skb_reason(skb, reason); 4524 return 0; 4525 } 4526 4527 static int ip6_pkt_discard(struct sk_buff *skb) 4528 { 4529 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES); 4530 } 4531 4532 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb) 4533 { 4534 skb->dev = skb_dst(skb)->dev; 4535 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES); 4536 } 4537 4538 static int ip6_pkt_prohibit(struct sk_buff *skb) 4539 { 4540 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES); 4541 } 4542 4543 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb) 4544 { 4545 skb->dev = skb_dst(skb)->dev; 4546 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES); 4547 } 4548 4549 /* 4550 * Allocate a dst for local (unicast / anycast) address. 4551 */ 4552 4553 struct fib6_info *addrconf_f6i_alloc(struct net *net, 4554 struct inet6_dev *idev, 4555 const struct in6_addr *addr, 4556 bool anycast, gfp_t gfp_flags, 4557 struct netlink_ext_ack *extack) 4558 { 4559 struct fib6_config cfg = { 4560 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL, 4561 .fc_ifindex = idev->dev->ifindex, 4562 .fc_flags = RTF_UP | RTF_NONEXTHOP, 4563 .fc_dst = *addr, 4564 .fc_dst_len = 128, 4565 .fc_protocol = RTPROT_KERNEL, 4566 .fc_nlinfo.nl_net = net, 4567 .fc_ignore_dev_down = true, 4568 }; 4569 struct fib6_info *f6i; 4570 4571 if (anycast) { 4572 cfg.fc_type = RTN_ANYCAST; 4573 cfg.fc_flags |= RTF_ANYCAST; 4574 } else { 4575 cfg.fc_type = RTN_LOCAL; 4576 cfg.fc_flags |= RTF_LOCAL; 4577 } 4578 4579 f6i = ip6_route_info_create(&cfg, gfp_flags, extack); 4580 if (!IS_ERR(f6i)) { 4581 f6i->dst_nocount = true; 4582 4583 if (!anycast && 4584 (net->ipv6.devconf_all->disable_policy || 4585 idev->cnf.disable_policy)) 4586 f6i->dst_nopolicy = true; 4587 } 4588 4589 return f6i; 4590 } 4591 4592 /* remove deleted ip from prefsrc entries */ 4593 struct arg_dev_net_ip { 4594 struct net *net; 4595 struct in6_addr *addr; 4596 }; 4597 4598 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg) 4599 { 4600 struct net *net = ((struct arg_dev_net_ip *)arg)->net; 4601 struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr; 4602 4603 if (!rt->nh && 4604 rt != net->ipv6.fib6_null_entry && 4605 ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) && 4606 !ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) { 4607 spin_lock_bh(&rt6_exception_lock); 4608 /* remove prefsrc entry */ 4609 rt->fib6_prefsrc.plen = 0; 4610 spin_unlock_bh(&rt6_exception_lock); 4611 } 4612 return 0; 4613 } 4614 4615 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp) 4616 { 4617 struct net *net = dev_net(ifp->idev->dev); 4618 struct arg_dev_net_ip adni = { 4619 .net = net, 4620 .addr = &ifp->addr, 4621 }; 4622 fib6_clean_all(net, fib6_remove_prefsrc, &adni); 4623 } 4624 4625 #define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT) 4626 4627 /* Remove routers and update dst entries when gateway turn into host. */ 4628 static int fib6_clean_tohost(struct fib6_info *rt, void *arg) 4629 { 4630 struct in6_addr *gateway = (struct in6_addr *)arg; 4631 struct fib6_nh *nh; 4632 4633 /* RA routes do not use nexthops */ 4634 if (rt->nh) 4635 return 0; 4636 4637 nh = rt->fib6_nh; 4638 if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) && 4639 nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6)) 4640 return -1; 4641 4642 /* Further clean up cached routes in exception table. 4643 * This is needed because cached route may have a different 4644 * gateway than its 'parent' in the case of an ip redirect. 4645 */ 4646 fib6_nh_exceptions_clean_tohost(nh, gateway); 4647 4648 return 0; 4649 } 4650 4651 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway) 4652 { 4653 fib6_clean_all(net, fib6_clean_tohost, gateway); 4654 } 4655 4656 struct arg_netdev_event { 4657 const struct net_device *dev; 4658 union { 4659 unsigned char nh_flags; 4660 unsigned long event; 4661 }; 4662 }; 4663 4664 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt) 4665 { 4666 struct fib6_info *iter; 4667 struct fib6_node *fn; 4668 4669 fn = rcu_dereference_protected(rt->fib6_node, 4670 lockdep_is_held(&rt->fib6_table->tb6_lock)); 4671 iter = rcu_dereference_protected(fn->leaf, 4672 lockdep_is_held(&rt->fib6_table->tb6_lock)); 4673 while (iter) { 4674 if (iter->fib6_metric == rt->fib6_metric && 4675 rt6_qualify_for_ecmp(iter)) 4676 return iter; 4677 iter = rcu_dereference_protected(iter->fib6_next, 4678 lockdep_is_held(&rt->fib6_table->tb6_lock)); 4679 } 4680 4681 return NULL; 4682 } 4683 4684 /* only called for fib entries with builtin fib6_nh */ 4685 static bool rt6_is_dead(const struct fib6_info *rt) 4686 { 4687 if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD || 4688 (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN && 4689 ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev))) 4690 return true; 4691 4692 return false; 4693 } 4694 4695 static int rt6_multipath_total_weight(const struct fib6_info *rt) 4696 { 4697 struct fib6_info *iter; 4698 int total = 0; 4699 4700 if (!rt6_is_dead(rt)) 4701 total += rt->fib6_nh->fib_nh_weight; 4702 4703 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) { 4704 if (!rt6_is_dead(iter)) 4705 total += iter->fib6_nh->fib_nh_weight; 4706 } 4707 4708 return total; 4709 } 4710 4711 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total) 4712 { 4713 int upper_bound = -1; 4714 4715 if (!rt6_is_dead(rt)) { 4716 *weight += rt->fib6_nh->fib_nh_weight; 4717 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31, 4718 total) - 1; 4719 } 4720 atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound); 4721 } 4722 4723 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total) 4724 { 4725 struct fib6_info *iter; 4726 int weight = 0; 4727 4728 rt6_upper_bound_set(rt, &weight, total); 4729 4730 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4731 rt6_upper_bound_set(iter, &weight, total); 4732 } 4733 4734 void rt6_multipath_rebalance(struct fib6_info *rt) 4735 { 4736 struct fib6_info *first; 4737 int total; 4738 4739 /* In case the entire multipath route was marked for flushing, 4740 * then there is no need to rebalance upon the removal of every 4741 * sibling route. 4742 */ 4743 if (!rt->fib6_nsiblings || rt->should_flush) 4744 return; 4745 4746 /* During lookup routes are evaluated in order, so we need to 4747 * make sure upper bounds are assigned from the first sibling 4748 * onwards. 4749 */ 4750 first = rt6_multipath_first_sibling(rt); 4751 if (WARN_ON_ONCE(!first)) 4752 return; 4753 4754 total = rt6_multipath_total_weight(first); 4755 rt6_multipath_upper_bound_set(first, total); 4756 } 4757 4758 static int fib6_ifup(struct fib6_info *rt, void *p_arg) 4759 { 4760 const struct arg_netdev_event *arg = p_arg; 4761 struct net *net = dev_net(arg->dev); 4762 4763 if (rt != net->ipv6.fib6_null_entry && !rt->nh && 4764 rt->fib6_nh->fib_nh_dev == arg->dev) { 4765 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags; 4766 fib6_update_sernum_upto_root(net, rt); 4767 rt6_multipath_rebalance(rt); 4768 } 4769 4770 return 0; 4771 } 4772 4773 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags) 4774 { 4775 struct arg_netdev_event arg = { 4776 .dev = dev, 4777 { 4778 .nh_flags = nh_flags, 4779 }, 4780 }; 4781 4782 if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev)) 4783 arg.nh_flags |= RTNH_F_LINKDOWN; 4784 4785 fib6_clean_all(dev_net(dev), fib6_ifup, &arg); 4786 } 4787 4788 /* only called for fib entries with inline fib6_nh */ 4789 static bool rt6_multipath_uses_dev(const struct fib6_info *rt, 4790 const struct net_device *dev) 4791 { 4792 struct fib6_info *iter; 4793 4794 if (rt->fib6_nh->fib_nh_dev == dev) 4795 return true; 4796 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4797 if (iter->fib6_nh->fib_nh_dev == dev) 4798 return true; 4799 4800 return false; 4801 } 4802 4803 static void rt6_multipath_flush(struct fib6_info *rt) 4804 { 4805 struct fib6_info *iter; 4806 4807 rt->should_flush = 1; 4808 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4809 iter->should_flush = 1; 4810 } 4811 4812 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt, 4813 const struct net_device *down_dev) 4814 { 4815 struct fib6_info *iter; 4816 unsigned int dead = 0; 4817 4818 if (rt->fib6_nh->fib_nh_dev == down_dev || 4819 rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD) 4820 dead++; 4821 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4822 if (iter->fib6_nh->fib_nh_dev == down_dev || 4823 iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD) 4824 dead++; 4825 4826 return dead; 4827 } 4828 4829 static void rt6_multipath_nh_flags_set(struct fib6_info *rt, 4830 const struct net_device *dev, 4831 unsigned char nh_flags) 4832 { 4833 struct fib6_info *iter; 4834 4835 if (rt->fib6_nh->fib_nh_dev == dev) 4836 rt->fib6_nh->fib_nh_flags |= nh_flags; 4837 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4838 if (iter->fib6_nh->fib_nh_dev == dev) 4839 iter->fib6_nh->fib_nh_flags |= nh_flags; 4840 } 4841 4842 /* called with write lock held for table with rt */ 4843 static int fib6_ifdown(struct fib6_info *rt, void *p_arg) 4844 { 4845 const struct arg_netdev_event *arg = p_arg; 4846 const struct net_device *dev = arg->dev; 4847 struct net *net = dev_net(dev); 4848 4849 if (rt == net->ipv6.fib6_null_entry || rt->nh) 4850 return 0; 4851 4852 switch (arg->event) { 4853 case NETDEV_UNREGISTER: 4854 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0; 4855 case NETDEV_DOWN: 4856 if (rt->should_flush) 4857 return -1; 4858 if (!rt->fib6_nsiblings) 4859 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0; 4860 if (rt6_multipath_uses_dev(rt, dev)) { 4861 unsigned int count; 4862 4863 count = rt6_multipath_dead_count(rt, dev); 4864 if (rt->fib6_nsiblings + 1 == count) { 4865 rt6_multipath_flush(rt); 4866 return -1; 4867 } 4868 rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD | 4869 RTNH_F_LINKDOWN); 4870 fib6_update_sernum(net, rt); 4871 rt6_multipath_rebalance(rt); 4872 } 4873 return -2; 4874 case NETDEV_CHANGE: 4875 if (rt->fib6_nh->fib_nh_dev != dev || 4876 rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) 4877 break; 4878 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN; 4879 rt6_multipath_rebalance(rt); 4880 break; 4881 } 4882 4883 return 0; 4884 } 4885 4886 void rt6_sync_down_dev(struct net_device *dev, unsigned long event) 4887 { 4888 struct arg_netdev_event arg = { 4889 .dev = dev, 4890 { 4891 .event = event, 4892 }, 4893 }; 4894 struct net *net = dev_net(dev); 4895 4896 if (net->ipv6.sysctl.skip_notify_on_dev_down) 4897 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg); 4898 else 4899 fib6_clean_all(net, fib6_ifdown, &arg); 4900 } 4901 4902 void rt6_disable_ip(struct net_device *dev, unsigned long event) 4903 { 4904 rt6_sync_down_dev(dev, event); 4905 rt6_uncached_list_flush_dev(dev); 4906 neigh_ifdown(&nd_tbl, dev); 4907 } 4908 4909 struct rt6_mtu_change_arg { 4910 struct net_device *dev; 4911 unsigned int mtu; 4912 struct fib6_info *f6i; 4913 }; 4914 4915 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg) 4916 { 4917 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg; 4918 struct fib6_info *f6i = arg->f6i; 4919 4920 /* For administrative MTU increase, there is no way to discover 4921 * IPv6 PMTU increase, so PMTU increase should be updated here. 4922 * Since RFC 1981 doesn't include administrative MTU increase 4923 * update PMTU increase is a MUST. (i.e. jumbo frame) 4924 */ 4925 if (nh->fib_nh_dev == arg->dev) { 4926 struct inet6_dev *idev = __in6_dev_get(arg->dev); 4927 u32 mtu = f6i->fib6_pmtu; 4928 4929 if (mtu >= arg->mtu || 4930 (mtu < arg->mtu && mtu == idev->cnf.mtu6)) 4931 fib6_metric_set(f6i, RTAX_MTU, arg->mtu); 4932 4933 spin_lock_bh(&rt6_exception_lock); 4934 rt6_exceptions_update_pmtu(idev, nh, arg->mtu); 4935 spin_unlock_bh(&rt6_exception_lock); 4936 } 4937 4938 return 0; 4939 } 4940 4941 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg) 4942 { 4943 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; 4944 struct inet6_dev *idev; 4945 4946 /* In IPv6 pmtu discovery is not optional, 4947 so that RTAX_MTU lock cannot disable it. 4948 We still use this lock to block changes 4949 caused by addrconf/ndisc. 4950 */ 4951 4952 idev = __in6_dev_get(arg->dev); 4953 if (!idev) 4954 return 0; 4955 4956 if (fib6_metric_locked(f6i, RTAX_MTU)) 4957 return 0; 4958 4959 arg->f6i = f6i; 4960 if (f6i->nh) { 4961 /* fib6_nh_mtu_change only returns 0, so this is safe */ 4962 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change, 4963 arg); 4964 } 4965 4966 return fib6_nh_mtu_change(f6i->fib6_nh, arg); 4967 } 4968 4969 void rt6_mtu_change(struct net_device *dev, unsigned int mtu) 4970 { 4971 struct rt6_mtu_change_arg arg = { 4972 .dev = dev, 4973 .mtu = mtu, 4974 }; 4975 4976 fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg); 4977 } 4978 4979 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = { 4980 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 4981 [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) }, 4982 [RTA_PREFSRC] = { .len = sizeof(struct in6_addr) }, 4983 [RTA_OIF] = { .type = NLA_U32 }, 4984 [RTA_IIF] = { .type = NLA_U32 }, 4985 [RTA_PRIORITY] = { .type = NLA_U32 }, 4986 [RTA_METRICS] = { .type = NLA_NESTED }, 4987 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 4988 [RTA_PREF] = { .type = NLA_U8 }, 4989 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 4990 [RTA_ENCAP] = { .type = NLA_NESTED }, 4991 [RTA_EXPIRES] = { .type = NLA_U32 }, 4992 [RTA_UID] = { .type = NLA_U32 }, 4993 [RTA_MARK] = { .type = NLA_U32 }, 4994 [RTA_TABLE] = { .type = NLA_U32 }, 4995 [RTA_IP_PROTO] = { .type = NLA_U8 }, 4996 [RTA_SPORT] = { .type = NLA_U16 }, 4997 [RTA_DPORT] = { .type = NLA_U16 }, 4998 [RTA_NH_ID] = { .type = NLA_U32 }, 4999 }; 5000 5001 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 5002 struct fib6_config *cfg, 5003 struct netlink_ext_ack *extack) 5004 { 5005 struct rtmsg *rtm; 5006 struct nlattr *tb[RTA_MAX+1]; 5007 unsigned int pref; 5008 int err; 5009 5010 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 5011 rtm_ipv6_policy, extack); 5012 if (err < 0) 5013 goto errout; 5014 5015 err = -EINVAL; 5016 rtm = nlmsg_data(nlh); 5017 5018 if (rtm->rtm_tos) { 5019 NL_SET_ERR_MSG(extack, 5020 "Invalid dsfield (tos): option not available for IPv6"); 5021 goto errout; 5022 } 5023 5024 *cfg = (struct fib6_config){ 5025 .fc_table = rtm->rtm_table, 5026 .fc_dst_len = rtm->rtm_dst_len, 5027 .fc_src_len = rtm->rtm_src_len, 5028 .fc_flags = RTF_UP, 5029 .fc_protocol = rtm->rtm_protocol, 5030 .fc_type = rtm->rtm_type, 5031 5032 .fc_nlinfo.portid = NETLINK_CB(skb).portid, 5033 .fc_nlinfo.nlh = nlh, 5034 .fc_nlinfo.nl_net = sock_net(skb->sk), 5035 }; 5036 5037 if (rtm->rtm_type == RTN_UNREACHABLE || 5038 rtm->rtm_type == RTN_BLACKHOLE || 5039 rtm->rtm_type == RTN_PROHIBIT || 5040 rtm->rtm_type == RTN_THROW) 5041 cfg->fc_flags |= RTF_REJECT; 5042 5043 if (rtm->rtm_type == RTN_LOCAL) 5044 cfg->fc_flags |= RTF_LOCAL; 5045 5046 if (rtm->rtm_flags & RTM_F_CLONED) 5047 cfg->fc_flags |= RTF_CACHE; 5048 5049 cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK); 5050 5051 if (tb[RTA_NH_ID]) { 5052 if (tb[RTA_GATEWAY] || tb[RTA_OIF] || 5053 tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) { 5054 NL_SET_ERR_MSG(extack, 5055 "Nexthop specification and nexthop id are mutually exclusive"); 5056 goto errout; 5057 } 5058 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]); 5059 } 5060 5061 if (tb[RTA_GATEWAY]) { 5062 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]); 5063 cfg->fc_flags |= RTF_GATEWAY; 5064 } 5065 if (tb[RTA_VIA]) { 5066 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute"); 5067 goto errout; 5068 } 5069 5070 if (tb[RTA_DST]) { 5071 int plen = (rtm->rtm_dst_len + 7) >> 3; 5072 5073 if (nla_len(tb[RTA_DST]) < plen) 5074 goto errout; 5075 5076 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen); 5077 } 5078 5079 if (tb[RTA_SRC]) { 5080 int plen = (rtm->rtm_src_len + 7) >> 3; 5081 5082 if (nla_len(tb[RTA_SRC]) < plen) 5083 goto errout; 5084 5085 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen); 5086 } 5087 5088 if (tb[RTA_PREFSRC]) 5089 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]); 5090 5091 if (tb[RTA_OIF]) 5092 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]); 5093 5094 if (tb[RTA_PRIORITY]) 5095 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]); 5096 5097 if (tb[RTA_METRICS]) { 5098 cfg->fc_mx = nla_data(tb[RTA_METRICS]); 5099 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]); 5100 } 5101 5102 if (tb[RTA_TABLE]) 5103 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]); 5104 5105 if (tb[RTA_MULTIPATH]) { 5106 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]); 5107 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]); 5108 5109 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp, 5110 cfg->fc_mp_len, extack); 5111 if (err < 0) 5112 goto errout; 5113 } 5114 5115 if (tb[RTA_PREF]) { 5116 pref = nla_get_u8(tb[RTA_PREF]); 5117 if (pref != ICMPV6_ROUTER_PREF_LOW && 5118 pref != ICMPV6_ROUTER_PREF_HIGH) 5119 pref = ICMPV6_ROUTER_PREF_MEDIUM; 5120 cfg->fc_flags |= RTF_PREF(pref); 5121 } 5122 5123 if (tb[RTA_ENCAP]) 5124 cfg->fc_encap = tb[RTA_ENCAP]; 5125 5126 if (tb[RTA_ENCAP_TYPE]) { 5127 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]); 5128 5129 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack); 5130 if (err < 0) 5131 goto errout; 5132 } 5133 5134 if (tb[RTA_EXPIRES]) { 5135 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ); 5136 5137 if (addrconf_finite_timeout(timeout)) { 5138 cfg->fc_expires = jiffies_to_clock_t(timeout * HZ); 5139 cfg->fc_flags |= RTF_EXPIRES; 5140 } 5141 } 5142 5143 err = 0; 5144 errout: 5145 return err; 5146 } 5147 5148 struct rt6_nh { 5149 struct fib6_info *fib6_info; 5150 struct fib6_config r_cfg; 5151 struct list_head next; 5152 }; 5153 5154 static int ip6_route_info_append(struct net *net, 5155 struct list_head *rt6_nh_list, 5156 struct fib6_info *rt, 5157 struct fib6_config *r_cfg) 5158 { 5159 struct rt6_nh *nh; 5160 int err = -EEXIST; 5161 5162 list_for_each_entry(nh, rt6_nh_list, next) { 5163 /* check if fib6_info already exists */ 5164 if (rt6_duplicate_nexthop(nh->fib6_info, rt)) 5165 return err; 5166 } 5167 5168 nh = kzalloc(sizeof(*nh), GFP_KERNEL); 5169 if (!nh) 5170 return -ENOMEM; 5171 nh->fib6_info = rt; 5172 memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg)); 5173 list_add_tail(&nh->next, rt6_nh_list); 5174 5175 return 0; 5176 } 5177 5178 static void ip6_route_mpath_notify(struct fib6_info *rt, 5179 struct fib6_info *rt_last, 5180 struct nl_info *info, 5181 __u16 nlflags) 5182 { 5183 /* if this is an APPEND route, then rt points to the first route 5184 * inserted and rt_last points to last route inserted. Userspace 5185 * wants a consistent dump of the route which starts at the first 5186 * nexthop. Since sibling routes are always added at the end of 5187 * the list, find the first sibling of the last route appended 5188 */ 5189 if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) { 5190 rt = list_first_entry(&rt_last->fib6_siblings, 5191 struct fib6_info, 5192 fib6_siblings); 5193 } 5194 5195 if (rt) 5196 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 5197 } 5198 5199 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt) 5200 { 5201 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 5202 bool should_notify = false; 5203 struct fib6_info *leaf; 5204 struct fib6_node *fn; 5205 5206 rcu_read_lock(); 5207 fn = rcu_dereference(rt->fib6_node); 5208 if (!fn) 5209 goto out; 5210 5211 leaf = rcu_dereference(fn->leaf); 5212 if (!leaf) 5213 goto out; 5214 5215 if (rt == leaf || 5216 (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric && 5217 rt6_qualify_for_ecmp(leaf))) 5218 should_notify = true; 5219 out: 5220 rcu_read_unlock(); 5221 5222 return should_notify; 5223 } 5224 5225 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla, 5226 struct netlink_ext_ack *extack) 5227 { 5228 if (nla_len(nla) < sizeof(*gw)) { 5229 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY"); 5230 return -EINVAL; 5231 } 5232 5233 *gw = nla_get_in6_addr(nla); 5234 5235 return 0; 5236 } 5237 5238 static int ip6_route_multipath_add(struct fib6_config *cfg, 5239 struct netlink_ext_ack *extack) 5240 { 5241 struct fib6_info *rt_notif = NULL, *rt_last = NULL; 5242 struct nl_info *info = &cfg->fc_nlinfo; 5243 struct fib6_config r_cfg; 5244 struct rtnexthop *rtnh; 5245 struct fib6_info *rt; 5246 struct rt6_nh *err_nh; 5247 struct rt6_nh *nh, *nh_safe; 5248 __u16 nlflags; 5249 int remaining; 5250 int attrlen; 5251 int err = 1; 5252 int nhn = 0; 5253 int replace = (cfg->fc_nlinfo.nlh && 5254 (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE)); 5255 LIST_HEAD(rt6_nh_list); 5256 5257 nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE; 5258 if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND) 5259 nlflags |= NLM_F_APPEND; 5260 5261 remaining = cfg->fc_mp_len; 5262 rtnh = (struct rtnexthop *)cfg->fc_mp; 5263 5264 /* Parse a Multipath Entry and build a list (rt6_nh_list) of 5265 * fib6_info structs per nexthop 5266 */ 5267 while (rtnh_ok(rtnh, remaining)) { 5268 memcpy(&r_cfg, cfg, sizeof(*cfg)); 5269 if (rtnh->rtnh_ifindex) 5270 r_cfg.fc_ifindex = rtnh->rtnh_ifindex; 5271 5272 attrlen = rtnh_attrlen(rtnh); 5273 if (attrlen > 0) { 5274 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 5275 5276 nla = nla_find(attrs, attrlen, RTA_GATEWAY); 5277 if (nla) { 5278 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, 5279 extack); 5280 if (err) 5281 goto cleanup; 5282 5283 r_cfg.fc_flags |= RTF_GATEWAY; 5284 } 5285 r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); 5286 5287 /* RTA_ENCAP_TYPE length checked in 5288 * lwtunnel_valid_encap_type_attr 5289 */ 5290 nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); 5291 if (nla) 5292 r_cfg.fc_encap_type = nla_get_u16(nla); 5293 } 5294 5295 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK); 5296 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack); 5297 if (IS_ERR(rt)) { 5298 err = PTR_ERR(rt); 5299 rt = NULL; 5300 goto cleanup; 5301 } 5302 if (!rt6_qualify_for_ecmp(rt)) { 5303 err = -EINVAL; 5304 NL_SET_ERR_MSG(extack, 5305 "Device only routes can not be added for IPv6 using the multipath API."); 5306 fib6_info_release(rt); 5307 goto cleanup; 5308 } 5309 5310 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1; 5311 5312 err = ip6_route_info_append(info->nl_net, &rt6_nh_list, 5313 rt, &r_cfg); 5314 if (err) { 5315 fib6_info_release(rt); 5316 goto cleanup; 5317 } 5318 5319 rtnh = rtnh_next(rtnh, &remaining); 5320 } 5321 5322 if (list_empty(&rt6_nh_list)) { 5323 NL_SET_ERR_MSG(extack, 5324 "Invalid nexthop configuration - no valid nexthops"); 5325 return -EINVAL; 5326 } 5327 5328 /* for add and replace send one notification with all nexthops. 5329 * Skip the notification in fib6_add_rt2node and send one with 5330 * the full route when done 5331 */ 5332 info->skip_notify = 1; 5333 5334 /* For add and replace, send one notification with all nexthops. For 5335 * append, send one notification with all appended nexthops. 5336 */ 5337 info->skip_notify_kernel = 1; 5338 5339 err_nh = NULL; 5340 list_for_each_entry(nh, &rt6_nh_list, next) { 5341 err = __ip6_ins_rt(nh->fib6_info, info, extack); 5342 5343 if (err) { 5344 if (replace && nhn) 5345 NL_SET_ERR_MSG_MOD(extack, 5346 "multipath route replace failed (check consistency of installed routes)"); 5347 err_nh = nh; 5348 goto add_errout; 5349 } 5350 /* save reference to last route successfully inserted */ 5351 rt_last = nh->fib6_info; 5352 5353 /* save reference to first route for notification */ 5354 if (!rt_notif) 5355 rt_notif = nh->fib6_info; 5356 5357 /* Because each route is added like a single route we remove 5358 * these flags after the first nexthop: if there is a collision, 5359 * we have already failed to add the first nexthop: 5360 * fib6_add_rt2node() has rejected it; when replacing, old 5361 * nexthops have been replaced by first new, the rest should 5362 * be added to it. 5363 */ 5364 if (cfg->fc_nlinfo.nlh) { 5365 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL | 5366 NLM_F_REPLACE); 5367 cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE; 5368 } 5369 nhn++; 5370 } 5371 5372 /* An in-kernel notification should only be sent in case the new 5373 * multipath route is added as the first route in the node, or if 5374 * it was appended to it. We pass 'rt_notif' since it is the first 5375 * sibling and might allow us to skip some checks in the replace case. 5376 */ 5377 if (ip6_route_mpath_should_notify(rt_notif)) { 5378 enum fib_event_type fib_event; 5379 5380 if (rt_notif->fib6_nsiblings != nhn - 1) 5381 fib_event = FIB_EVENT_ENTRY_APPEND; 5382 else 5383 fib_event = FIB_EVENT_ENTRY_REPLACE; 5384 5385 err = call_fib6_multipath_entry_notifiers(info->nl_net, 5386 fib_event, rt_notif, 5387 nhn - 1, extack); 5388 if (err) { 5389 /* Delete all the siblings that were just added */ 5390 err_nh = NULL; 5391 goto add_errout; 5392 } 5393 } 5394 5395 /* success ... tell user about new route */ 5396 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags); 5397 goto cleanup; 5398 5399 add_errout: 5400 /* send notification for routes that were added so that 5401 * the delete notifications sent by ip6_route_del are 5402 * coherent 5403 */ 5404 if (rt_notif) 5405 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags); 5406 5407 /* Delete routes that were already added */ 5408 list_for_each_entry(nh, &rt6_nh_list, next) { 5409 if (err_nh == nh) 5410 break; 5411 ip6_route_del(&nh->r_cfg, extack); 5412 } 5413 5414 cleanup: 5415 list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) { 5416 fib6_info_release(nh->fib6_info); 5417 list_del(&nh->next); 5418 kfree(nh); 5419 } 5420 5421 return err; 5422 } 5423 5424 static int ip6_route_multipath_del(struct fib6_config *cfg, 5425 struct netlink_ext_ack *extack) 5426 { 5427 struct fib6_config r_cfg; 5428 struct rtnexthop *rtnh; 5429 int last_err = 0; 5430 int remaining; 5431 int attrlen; 5432 int err; 5433 5434 remaining = cfg->fc_mp_len; 5435 rtnh = (struct rtnexthop *)cfg->fc_mp; 5436 5437 /* Parse a Multipath Entry */ 5438 while (rtnh_ok(rtnh, remaining)) { 5439 memcpy(&r_cfg, cfg, sizeof(*cfg)); 5440 if (rtnh->rtnh_ifindex) 5441 r_cfg.fc_ifindex = rtnh->rtnh_ifindex; 5442 5443 attrlen = rtnh_attrlen(rtnh); 5444 if (attrlen > 0) { 5445 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 5446 5447 nla = nla_find(attrs, attrlen, RTA_GATEWAY); 5448 if (nla) { 5449 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, 5450 extack); 5451 if (err) { 5452 last_err = err; 5453 goto next_rtnh; 5454 } 5455 5456 r_cfg.fc_flags |= RTF_GATEWAY; 5457 } 5458 } 5459 err = ip6_route_del(&r_cfg, extack); 5460 if (err) 5461 last_err = err; 5462 5463 next_rtnh: 5464 rtnh = rtnh_next(rtnh, &remaining); 5465 } 5466 5467 return last_err; 5468 } 5469 5470 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 5471 struct netlink_ext_ack *extack) 5472 { 5473 struct fib6_config cfg; 5474 int err; 5475 5476 err = rtm_to_fib6_config(skb, nlh, &cfg, extack); 5477 if (err < 0) 5478 return err; 5479 5480 if (cfg.fc_nh_id && 5481 !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) { 5482 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 5483 return -EINVAL; 5484 } 5485 5486 if (cfg.fc_mp) 5487 return ip6_route_multipath_del(&cfg, extack); 5488 else { 5489 cfg.fc_delete_all_nh = 1; 5490 return ip6_route_del(&cfg, extack); 5491 } 5492 } 5493 5494 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 5495 struct netlink_ext_ack *extack) 5496 { 5497 struct fib6_config cfg; 5498 int err; 5499 5500 err = rtm_to_fib6_config(skb, nlh, &cfg, extack); 5501 if (err < 0) 5502 return err; 5503 5504 if (cfg.fc_metric == 0) 5505 cfg.fc_metric = IP6_RT_PRIO_USER; 5506 5507 if (cfg.fc_mp) 5508 return ip6_route_multipath_add(&cfg, extack); 5509 else 5510 return ip6_route_add(&cfg, GFP_KERNEL, extack); 5511 } 5512 5513 /* add the overhead of this fib6_nh to nexthop_len */ 5514 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg) 5515 { 5516 int *nexthop_len = arg; 5517 5518 *nexthop_len += nla_total_size(0) /* RTA_MULTIPATH */ 5519 + NLA_ALIGN(sizeof(struct rtnexthop)) 5520 + nla_total_size(16); /* RTA_GATEWAY */ 5521 5522 if (nh->fib_nh_lws) { 5523 /* RTA_ENCAP_TYPE */ 5524 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws); 5525 /* RTA_ENCAP */ 5526 *nexthop_len += nla_total_size(2); 5527 } 5528 5529 return 0; 5530 } 5531 5532 static size_t rt6_nlmsg_size(struct fib6_info *f6i) 5533 { 5534 int nexthop_len; 5535 5536 if (f6i->nh) { 5537 nexthop_len = nla_total_size(4); /* RTA_NH_ID */ 5538 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size, 5539 &nexthop_len); 5540 } else { 5541 struct fib6_info *sibling, *next_sibling; 5542 struct fib6_nh *nh = f6i->fib6_nh; 5543 5544 nexthop_len = 0; 5545 if (f6i->fib6_nsiblings) { 5546 rt6_nh_nlmsg_size(nh, &nexthop_len); 5547 5548 list_for_each_entry_safe(sibling, next_sibling, 5549 &f6i->fib6_siblings, fib6_siblings) { 5550 rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len); 5551 } 5552 } 5553 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws); 5554 } 5555 5556 return NLMSG_ALIGN(sizeof(struct rtmsg)) 5557 + nla_total_size(16) /* RTA_SRC */ 5558 + nla_total_size(16) /* RTA_DST */ 5559 + nla_total_size(16) /* RTA_GATEWAY */ 5560 + nla_total_size(16) /* RTA_PREFSRC */ 5561 + nla_total_size(4) /* RTA_TABLE */ 5562 + nla_total_size(4) /* RTA_IIF */ 5563 + nla_total_size(4) /* RTA_OIF */ 5564 + nla_total_size(4) /* RTA_PRIORITY */ 5565 + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */ 5566 + nla_total_size(sizeof(struct rta_cacheinfo)) 5567 + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */ 5568 + nla_total_size(1) /* RTA_PREF */ 5569 + nexthop_len; 5570 } 5571 5572 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh, 5573 unsigned char *flags) 5574 { 5575 if (nexthop_is_multipath(nh)) { 5576 struct nlattr *mp; 5577 5578 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); 5579 if (!mp) 5580 goto nla_put_failure; 5581 5582 if (nexthop_mpath_fill_node(skb, nh, AF_INET6)) 5583 goto nla_put_failure; 5584 5585 nla_nest_end(skb, mp); 5586 } else { 5587 struct fib6_nh *fib6_nh; 5588 5589 fib6_nh = nexthop_fib6_nh(nh); 5590 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6, 5591 flags, false) < 0) 5592 goto nla_put_failure; 5593 } 5594 5595 return 0; 5596 5597 nla_put_failure: 5598 return -EMSGSIZE; 5599 } 5600 5601 static int rt6_fill_node(struct net *net, struct sk_buff *skb, 5602 struct fib6_info *rt, struct dst_entry *dst, 5603 struct in6_addr *dest, struct in6_addr *src, 5604 int iif, int type, u32 portid, u32 seq, 5605 unsigned int flags) 5606 { 5607 struct rt6_info *rt6 = (struct rt6_info *)dst; 5608 struct rt6key *rt6_dst, *rt6_src; 5609 u32 *pmetrics, table, rt6_flags; 5610 unsigned char nh_flags = 0; 5611 struct nlmsghdr *nlh; 5612 struct rtmsg *rtm; 5613 long expires = 0; 5614 5615 nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags); 5616 if (!nlh) 5617 return -EMSGSIZE; 5618 5619 if (rt6) { 5620 rt6_dst = &rt6->rt6i_dst; 5621 rt6_src = &rt6->rt6i_src; 5622 rt6_flags = rt6->rt6i_flags; 5623 } else { 5624 rt6_dst = &rt->fib6_dst; 5625 rt6_src = &rt->fib6_src; 5626 rt6_flags = rt->fib6_flags; 5627 } 5628 5629 rtm = nlmsg_data(nlh); 5630 rtm->rtm_family = AF_INET6; 5631 rtm->rtm_dst_len = rt6_dst->plen; 5632 rtm->rtm_src_len = rt6_src->plen; 5633 rtm->rtm_tos = 0; 5634 if (rt->fib6_table) 5635 table = rt->fib6_table->tb6_id; 5636 else 5637 table = RT6_TABLE_UNSPEC; 5638 rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT; 5639 if (nla_put_u32(skb, RTA_TABLE, table)) 5640 goto nla_put_failure; 5641 5642 rtm->rtm_type = rt->fib6_type; 5643 rtm->rtm_flags = 0; 5644 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 5645 rtm->rtm_protocol = rt->fib6_protocol; 5646 5647 if (rt6_flags & RTF_CACHE) 5648 rtm->rtm_flags |= RTM_F_CLONED; 5649 5650 if (dest) { 5651 if (nla_put_in6_addr(skb, RTA_DST, dest)) 5652 goto nla_put_failure; 5653 rtm->rtm_dst_len = 128; 5654 } else if (rtm->rtm_dst_len) 5655 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr)) 5656 goto nla_put_failure; 5657 #ifdef CONFIG_IPV6_SUBTREES 5658 if (src) { 5659 if (nla_put_in6_addr(skb, RTA_SRC, src)) 5660 goto nla_put_failure; 5661 rtm->rtm_src_len = 128; 5662 } else if (rtm->rtm_src_len && 5663 nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr)) 5664 goto nla_put_failure; 5665 #endif 5666 if (iif) { 5667 #ifdef CONFIG_IPV6_MROUTE 5668 if (ipv6_addr_is_multicast(&rt6_dst->addr)) { 5669 int err = ip6mr_get_route(net, skb, rtm, portid); 5670 5671 if (err == 0) 5672 return 0; 5673 if (err < 0) 5674 goto nla_put_failure; 5675 } else 5676 #endif 5677 if (nla_put_u32(skb, RTA_IIF, iif)) 5678 goto nla_put_failure; 5679 } else if (dest) { 5680 struct in6_addr saddr_buf; 5681 if (ip6_route_get_saddr(net, rt, dest, 0, 0, &saddr_buf) == 0 && 5682 nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) 5683 goto nla_put_failure; 5684 } 5685 5686 if (rt->fib6_prefsrc.plen) { 5687 struct in6_addr saddr_buf; 5688 saddr_buf = rt->fib6_prefsrc.addr; 5689 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) 5690 goto nla_put_failure; 5691 } 5692 5693 pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics; 5694 if (rtnetlink_put_metrics(skb, pmetrics) < 0) 5695 goto nla_put_failure; 5696 5697 if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric)) 5698 goto nla_put_failure; 5699 5700 /* For multipath routes, walk the siblings list and add 5701 * each as a nexthop within RTA_MULTIPATH. 5702 */ 5703 if (rt6) { 5704 if (rt6_flags & RTF_GATEWAY && 5705 nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway)) 5706 goto nla_put_failure; 5707 5708 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex)) 5709 goto nla_put_failure; 5710 5711 if (dst->lwtstate && 5712 lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 5713 goto nla_put_failure; 5714 } else if (rt->fib6_nsiblings) { 5715 struct fib6_info *sibling, *next_sibling; 5716 struct nlattr *mp; 5717 5718 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); 5719 if (!mp) 5720 goto nla_put_failure; 5721 5722 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common, 5723 rt->fib6_nh->fib_nh_weight, AF_INET6, 5724 0) < 0) 5725 goto nla_put_failure; 5726 5727 list_for_each_entry_safe(sibling, next_sibling, 5728 &rt->fib6_siblings, fib6_siblings) { 5729 if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common, 5730 sibling->fib6_nh->fib_nh_weight, 5731 AF_INET6, 0) < 0) 5732 goto nla_put_failure; 5733 } 5734 5735 nla_nest_end(skb, mp); 5736 } else if (rt->nh) { 5737 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id)) 5738 goto nla_put_failure; 5739 5740 if (nexthop_is_blackhole(rt->nh)) 5741 rtm->rtm_type = RTN_BLACKHOLE; 5742 5743 if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) && 5744 rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0) 5745 goto nla_put_failure; 5746 5747 rtm->rtm_flags |= nh_flags; 5748 } else { 5749 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6, 5750 &nh_flags, false) < 0) 5751 goto nla_put_failure; 5752 5753 rtm->rtm_flags |= nh_flags; 5754 } 5755 5756 if (rt6_flags & RTF_EXPIRES) { 5757 expires = dst ? dst->expires : rt->expires; 5758 expires -= jiffies; 5759 } 5760 5761 if (!dst) { 5762 if (READ_ONCE(rt->offload)) 5763 rtm->rtm_flags |= RTM_F_OFFLOAD; 5764 if (READ_ONCE(rt->trap)) 5765 rtm->rtm_flags |= RTM_F_TRAP; 5766 if (READ_ONCE(rt->offload_failed)) 5767 rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED; 5768 } 5769 5770 if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0) 5771 goto nla_put_failure; 5772 5773 if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags))) 5774 goto nla_put_failure; 5775 5776 5777 nlmsg_end(skb, nlh); 5778 return 0; 5779 5780 nla_put_failure: 5781 nlmsg_cancel(skb, nlh); 5782 return -EMSGSIZE; 5783 } 5784 5785 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg) 5786 { 5787 const struct net_device *dev = arg; 5788 5789 if (nh->fib_nh_dev == dev) 5790 return 1; 5791 5792 return 0; 5793 } 5794 5795 static bool fib6_info_uses_dev(const struct fib6_info *f6i, 5796 const struct net_device *dev) 5797 { 5798 if (f6i->nh) { 5799 struct net_device *_dev = (struct net_device *)dev; 5800 5801 return !!nexthop_for_each_fib6_nh(f6i->nh, 5802 fib6_info_nh_uses_dev, 5803 _dev); 5804 } 5805 5806 if (f6i->fib6_nh->fib_nh_dev == dev) 5807 return true; 5808 5809 if (f6i->fib6_nsiblings) { 5810 struct fib6_info *sibling, *next_sibling; 5811 5812 list_for_each_entry_safe(sibling, next_sibling, 5813 &f6i->fib6_siblings, fib6_siblings) { 5814 if (sibling->fib6_nh->fib_nh_dev == dev) 5815 return true; 5816 } 5817 } 5818 5819 return false; 5820 } 5821 5822 struct fib6_nh_exception_dump_walker { 5823 struct rt6_rtnl_dump_arg *dump; 5824 struct fib6_info *rt; 5825 unsigned int flags; 5826 unsigned int skip; 5827 unsigned int count; 5828 }; 5829 5830 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg) 5831 { 5832 struct fib6_nh_exception_dump_walker *w = arg; 5833 struct rt6_rtnl_dump_arg *dump = w->dump; 5834 struct rt6_exception_bucket *bucket; 5835 struct rt6_exception *rt6_ex; 5836 int i, err; 5837 5838 bucket = fib6_nh_get_excptn_bucket(nh, NULL); 5839 if (!bucket) 5840 return 0; 5841 5842 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 5843 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { 5844 if (w->skip) { 5845 w->skip--; 5846 continue; 5847 } 5848 5849 /* Expiration of entries doesn't bump sernum, insertion 5850 * does. Removal is triggered by insertion, so we can 5851 * rely on the fact that if entries change between two 5852 * partial dumps, this node is scanned again completely, 5853 * see rt6_insert_exception() and fib6_dump_table(). 5854 * 5855 * Count expired entries we go through as handled 5856 * entries that we'll skip next time, in case of partial 5857 * node dump. Otherwise, if entries expire meanwhile, 5858 * we'll skip the wrong amount. 5859 */ 5860 if (rt6_check_expired(rt6_ex->rt6i)) { 5861 w->count++; 5862 continue; 5863 } 5864 5865 err = rt6_fill_node(dump->net, dump->skb, w->rt, 5866 &rt6_ex->rt6i->dst, NULL, NULL, 0, 5867 RTM_NEWROUTE, 5868 NETLINK_CB(dump->cb->skb).portid, 5869 dump->cb->nlh->nlmsg_seq, w->flags); 5870 if (err) 5871 return err; 5872 5873 w->count++; 5874 } 5875 bucket++; 5876 } 5877 5878 return 0; 5879 } 5880 5881 /* Return -1 if done with node, number of handled routes on partial dump */ 5882 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip) 5883 { 5884 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; 5885 struct fib_dump_filter *filter = &arg->filter; 5886 unsigned int flags = NLM_F_MULTI; 5887 struct net *net = arg->net; 5888 int count = 0; 5889 5890 if (rt == net->ipv6.fib6_null_entry) 5891 return -1; 5892 5893 if ((filter->flags & RTM_F_PREFIX) && 5894 !(rt->fib6_flags & RTF_PREFIX_RT)) { 5895 /* success since this is not a prefix route */ 5896 return -1; 5897 } 5898 if (filter->filter_set && 5899 ((filter->rt_type && rt->fib6_type != filter->rt_type) || 5900 (filter->dev && !fib6_info_uses_dev(rt, filter->dev)) || 5901 (filter->protocol && rt->fib6_protocol != filter->protocol))) { 5902 return -1; 5903 } 5904 5905 if (filter->filter_set || 5906 !filter->dump_routes || !filter->dump_exceptions) { 5907 flags |= NLM_F_DUMP_FILTERED; 5908 } 5909 5910 if (filter->dump_routes) { 5911 if (skip) { 5912 skip--; 5913 } else { 5914 if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL, 5915 0, RTM_NEWROUTE, 5916 NETLINK_CB(arg->cb->skb).portid, 5917 arg->cb->nlh->nlmsg_seq, flags)) { 5918 return 0; 5919 } 5920 count++; 5921 } 5922 } 5923 5924 if (filter->dump_exceptions) { 5925 struct fib6_nh_exception_dump_walker w = { .dump = arg, 5926 .rt = rt, 5927 .flags = flags, 5928 .skip = skip, 5929 .count = 0 }; 5930 int err; 5931 5932 rcu_read_lock(); 5933 if (rt->nh) { 5934 err = nexthop_for_each_fib6_nh(rt->nh, 5935 rt6_nh_dump_exceptions, 5936 &w); 5937 } else { 5938 err = rt6_nh_dump_exceptions(rt->fib6_nh, &w); 5939 } 5940 rcu_read_unlock(); 5941 5942 if (err) 5943 return count + w.count; 5944 } 5945 5946 return -1; 5947 } 5948 5949 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb, 5950 const struct nlmsghdr *nlh, 5951 struct nlattr **tb, 5952 struct netlink_ext_ack *extack) 5953 { 5954 struct rtmsg *rtm; 5955 int i, err; 5956 5957 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 5958 NL_SET_ERR_MSG_MOD(extack, 5959 "Invalid header for get route request"); 5960 return -EINVAL; 5961 } 5962 5963 if (!netlink_strict_get_check(skb)) 5964 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 5965 rtm_ipv6_policy, extack); 5966 5967 rtm = nlmsg_data(nlh); 5968 if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) || 5969 (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) || 5970 rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope || 5971 rtm->rtm_type) { 5972 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request"); 5973 return -EINVAL; 5974 } 5975 if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) { 5976 NL_SET_ERR_MSG_MOD(extack, 5977 "Invalid flags for get route request"); 5978 return -EINVAL; 5979 } 5980 5981 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 5982 rtm_ipv6_policy, extack); 5983 if (err) 5984 return err; 5985 5986 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 5987 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 5988 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6"); 5989 return -EINVAL; 5990 } 5991 5992 for (i = 0; i <= RTA_MAX; i++) { 5993 if (!tb[i]) 5994 continue; 5995 5996 switch (i) { 5997 case RTA_SRC: 5998 case RTA_DST: 5999 case RTA_IIF: 6000 case RTA_OIF: 6001 case RTA_MARK: 6002 case RTA_UID: 6003 case RTA_SPORT: 6004 case RTA_DPORT: 6005 case RTA_IP_PROTO: 6006 break; 6007 default: 6008 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request"); 6009 return -EINVAL; 6010 } 6011 } 6012 6013 return 0; 6014 } 6015 6016 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 6017 struct netlink_ext_ack *extack) 6018 { 6019 struct net *net = sock_net(in_skb->sk); 6020 struct nlattr *tb[RTA_MAX+1]; 6021 int err, iif = 0, oif = 0; 6022 struct fib6_info *from; 6023 struct dst_entry *dst; 6024 struct rt6_info *rt; 6025 struct sk_buff *skb; 6026 struct rtmsg *rtm; 6027 struct flowi6 fl6 = {}; 6028 bool fibmatch; 6029 6030 err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 6031 if (err < 0) 6032 goto errout; 6033 6034 err = -EINVAL; 6035 rtm = nlmsg_data(nlh); 6036 fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0); 6037 fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH); 6038 6039 if (tb[RTA_SRC]) { 6040 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr)) 6041 goto errout; 6042 6043 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]); 6044 } 6045 6046 if (tb[RTA_DST]) { 6047 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr)) 6048 goto errout; 6049 6050 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]); 6051 } 6052 6053 if (tb[RTA_IIF]) 6054 iif = nla_get_u32(tb[RTA_IIF]); 6055 6056 if (tb[RTA_OIF]) 6057 oif = nla_get_u32(tb[RTA_OIF]); 6058 6059 if (tb[RTA_MARK]) 6060 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]); 6061 6062 if (tb[RTA_UID]) 6063 fl6.flowi6_uid = make_kuid(current_user_ns(), 6064 nla_get_u32(tb[RTA_UID])); 6065 else 6066 fl6.flowi6_uid = iif ? INVALID_UID : current_uid(); 6067 6068 if (tb[RTA_SPORT]) 6069 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]); 6070 6071 if (tb[RTA_DPORT]) 6072 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]); 6073 6074 if (tb[RTA_IP_PROTO]) { 6075 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 6076 &fl6.flowi6_proto, AF_INET6, 6077 extack); 6078 if (err) 6079 goto errout; 6080 } 6081 6082 if (iif) { 6083 struct net_device *dev; 6084 int flags = 0; 6085 6086 rcu_read_lock(); 6087 6088 dev = dev_get_by_index_rcu(net, iif); 6089 if (!dev) { 6090 rcu_read_unlock(); 6091 err = -ENODEV; 6092 goto errout; 6093 } 6094 6095 fl6.flowi6_iif = iif; 6096 6097 if (!ipv6_addr_any(&fl6.saddr)) 6098 flags |= RT6_LOOKUP_F_HAS_SADDR; 6099 6100 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags); 6101 6102 rcu_read_unlock(); 6103 } else { 6104 fl6.flowi6_oif = oif; 6105 6106 dst = ip6_route_output(net, NULL, &fl6); 6107 } 6108 6109 6110 rt = container_of(dst, struct rt6_info, dst); 6111 if (rt->dst.error) { 6112 err = rt->dst.error; 6113 ip6_rt_put(rt); 6114 goto errout; 6115 } 6116 6117 if (rt == net->ipv6.ip6_null_entry) { 6118 err = rt->dst.error; 6119 ip6_rt_put(rt); 6120 goto errout; 6121 } 6122 6123 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 6124 if (!skb) { 6125 ip6_rt_put(rt); 6126 err = -ENOBUFS; 6127 goto errout; 6128 } 6129 6130 skb_dst_set(skb, &rt->dst); 6131 6132 rcu_read_lock(); 6133 from = rcu_dereference(rt->from); 6134 if (from) { 6135 if (fibmatch) 6136 err = rt6_fill_node(net, skb, from, NULL, NULL, NULL, 6137 iif, RTM_NEWROUTE, 6138 NETLINK_CB(in_skb).portid, 6139 nlh->nlmsg_seq, 0); 6140 else 6141 err = rt6_fill_node(net, skb, from, dst, &fl6.daddr, 6142 &fl6.saddr, iif, RTM_NEWROUTE, 6143 NETLINK_CB(in_skb).portid, 6144 nlh->nlmsg_seq, 0); 6145 } else { 6146 err = -ENETUNREACH; 6147 } 6148 rcu_read_unlock(); 6149 6150 if (err < 0) { 6151 kfree_skb(skb); 6152 goto errout; 6153 } 6154 6155 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 6156 errout: 6157 return err; 6158 } 6159 6160 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 6161 unsigned int nlm_flags) 6162 { 6163 struct sk_buff *skb; 6164 struct net *net = info->nl_net; 6165 u32 seq; 6166 int err; 6167 6168 err = -ENOBUFS; 6169 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 6170 6171 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); 6172 if (!skb) 6173 goto errout; 6174 6175 err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0, 6176 event, info->portid, seq, nlm_flags); 6177 if (err < 0) { 6178 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 6179 WARN_ON(err == -EMSGSIZE); 6180 kfree_skb(skb); 6181 goto errout; 6182 } 6183 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, 6184 info->nlh, gfp_any()); 6185 return; 6186 errout: 6187 if (err < 0) 6188 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 6189 } 6190 6191 void fib6_rt_update(struct net *net, struct fib6_info *rt, 6192 struct nl_info *info) 6193 { 6194 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 6195 struct sk_buff *skb; 6196 int err = -ENOBUFS; 6197 6198 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); 6199 if (!skb) 6200 goto errout; 6201 6202 err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0, 6203 RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE); 6204 if (err < 0) { 6205 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 6206 WARN_ON(err == -EMSGSIZE); 6207 kfree_skb(skb); 6208 goto errout; 6209 } 6210 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, 6211 info->nlh, gfp_any()); 6212 return; 6213 errout: 6214 if (err < 0) 6215 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 6216 } 6217 6218 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, 6219 bool offload, bool trap, bool offload_failed) 6220 { 6221 struct sk_buff *skb; 6222 int err; 6223 6224 if (READ_ONCE(f6i->offload) == offload && 6225 READ_ONCE(f6i->trap) == trap && 6226 READ_ONCE(f6i->offload_failed) == offload_failed) 6227 return; 6228 6229 WRITE_ONCE(f6i->offload, offload); 6230 WRITE_ONCE(f6i->trap, trap); 6231 6232 /* 2 means send notifications only if offload_failed was changed. */ 6233 if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 && 6234 READ_ONCE(f6i->offload_failed) == offload_failed) 6235 return; 6236 6237 WRITE_ONCE(f6i->offload_failed, offload_failed); 6238 6239 if (!rcu_access_pointer(f6i->fib6_node)) 6240 /* The route was removed from the tree, do not send 6241 * notification. 6242 */ 6243 return; 6244 6245 if (!net->ipv6.sysctl.fib_notify_on_flag_change) 6246 return; 6247 6248 skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL); 6249 if (!skb) { 6250 err = -ENOBUFS; 6251 goto errout; 6252 } 6253 6254 err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0, 6255 0, 0); 6256 if (err < 0) { 6257 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 6258 WARN_ON(err == -EMSGSIZE); 6259 kfree_skb(skb); 6260 goto errout; 6261 } 6262 6263 rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL); 6264 return; 6265 6266 errout: 6267 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 6268 } 6269 EXPORT_SYMBOL(fib6_info_hw_flags_set); 6270 6271 static int ip6_route_dev_notify(struct notifier_block *this, 6272 unsigned long event, void *ptr) 6273 { 6274 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 6275 struct net *net = dev_net(dev); 6276 6277 if (!(dev->flags & IFF_LOOPBACK)) 6278 return NOTIFY_OK; 6279 6280 if (event == NETDEV_REGISTER) { 6281 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev; 6282 net->ipv6.ip6_null_entry->dst.dev = dev; 6283 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev); 6284 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6285 net->ipv6.ip6_prohibit_entry->dst.dev = dev; 6286 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev); 6287 net->ipv6.ip6_blk_hole_entry->dst.dev = dev; 6288 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); 6289 #endif 6290 } else if (event == NETDEV_UNREGISTER && 6291 dev->reg_state != NETREG_UNREGISTERED) { 6292 /* NETDEV_UNREGISTER could be fired for multiple times by 6293 * netdev_wait_allrefs(). Make sure we only call this once. 6294 */ 6295 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev); 6296 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6297 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev); 6298 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev); 6299 #endif 6300 } 6301 6302 return NOTIFY_OK; 6303 } 6304 6305 /* 6306 * /proc 6307 */ 6308 6309 #ifdef CONFIG_PROC_FS 6310 static int rt6_stats_seq_show(struct seq_file *seq, void *v) 6311 { 6312 struct net *net = (struct net *)seq->private; 6313 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", 6314 net->ipv6.rt6_stats->fib_nodes, 6315 net->ipv6.rt6_stats->fib_route_nodes, 6316 atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc), 6317 net->ipv6.rt6_stats->fib_rt_entries, 6318 net->ipv6.rt6_stats->fib_rt_cache, 6319 dst_entries_get_slow(&net->ipv6.ip6_dst_ops), 6320 net->ipv6.rt6_stats->fib_discarded_routes); 6321 6322 return 0; 6323 } 6324 #endif /* CONFIG_PROC_FS */ 6325 6326 #ifdef CONFIG_SYSCTL 6327 6328 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write, 6329 void *buffer, size_t *lenp, loff_t *ppos) 6330 { 6331 struct net *net; 6332 int delay; 6333 int ret; 6334 if (!write) 6335 return -EINVAL; 6336 6337 ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 6338 if (ret) 6339 return ret; 6340 6341 net = (struct net *)ctl->extra1; 6342 delay = net->ipv6.sysctl.flush_delay; 6343 fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0); 6344 return 0; 6345 } 6346 6347 static struct ctl_table ipv6_route_table_template[] = { 6348 { 6349 .procname = "max_size", 6350 .data = &init_net.ipv6.sysctl.ip6_rt_max_size, 6351 .maxlen = sizeof(int), 6352 .mode = 0644, 6353 .proc_handler = proc_dointvec, 6354 }, 6355 { 6356 .procname = "gc_thresh", 6357 .data = &ip6_dst_ops_template.gc_thresh, 6358 .maxlen = sizeof(int), 6359 .mode = 0644, 6360 .proc_handler = proc_dointvec, 6361 }, 6362 { 6363 .procname = "flush", 6364 .data = &init_net.ipv6.sysctl.flush_delay, 6365 .maxlen = sizeof(int), 6366 .mode = 0200, 6367 .proc_handler = ipv6_sysctl_rtcache_flush 6368 }, 6369 { 6370 .procname = "gc_min_interval", 6371 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 6372 .maxlen = sizeof(int), 6373 .mode = 0644, 6374 .proc_handler = proc_dointvec_jiffies, 6375 }, 6376 { 6377 .procname = "gc_timeout", 6378 .data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout, 6379 .maxlen = sizeof(int), 6380 .mode = 0644, 6381 .proc_handler = proc_dointvec_jiffies, 6382 }, 6383 { 6384 .procname = "gc_interval", 6385 .data = &init_net.ipv6.sysctl.ip6_rt_gc_interval, 6386 .maxlen = sizeof(int), 6387 .mode = 0644, 6388 .proc_handler = proc_dointvec_jiffies, 6389 }, 6390 { 6391 .procname = "gc_elasticity", 6392 .data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity, 6393 .maxlen = sizeof(int), 6394 .mode = 0644, 6395 .proc_handler = proc_dointvec, 6396 }, 6397 { 6398 .procname = "mtu_expires", 6399 .data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires, 6400 .maxlen = sizeof(int), 6401 .mode = 0644, 6402 .proc_handler = proc_dointvec_jiffies, 6403 }, 6404 { 6405 .procname = "min_adv_mss", 6406 .data = &init_net.ipv6.sysctl.ip6_rt_min_advmss, 6407 .maxlen = sizeof(int), 6408 .mode = 0644, 6409 .proc_handler = proc_dointvec, 6410 }, 6411 { 6412 .procname = "gc_min_interval_ms", 6413 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 6414 .maxlen = sizeof(int), 6415 .mode = 0644, 6416 .proc_handler = proc_dointvec_ms_jiffies, 6417 }, 6418 { 6419 .procname = "skip_notify_on_dev_down", 6420 .data = &init_net.ipv6.sysctl.skip_notify_on_dev_down, 6421 .maxlen = sizeof(u8), 6422 .mode = 0644, 6423 .proc_handler = proc_dou8vec_minmax, 6424 .extra1 = SYSCTL_ZERO, 6425 .extra2 = SYSCTL_ONE, 6426 }, 6427 { } 6428 }; 6429 6430 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net) 6431 { 6432 struct ctl_table *table; 6433 6434 table = kmemdup(ipv6_route_table_template, 6435 sizeof(ipv6_route_table_template), 6436 GFP_KERNEL); 6437 6438 if (table) { 6439 table[0].data = &net->ipv6.sysctl.ip6_rt_max_size; 6440 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh; 6441 table[2].data = &net->ipv6.sysctl.flush_delay; 6442 table[2].extra1 = net; 6443 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 6444 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout; 6445 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval; 6446 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity; 6447 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires; 6448 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss; 6449 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 6450 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down; 6451 6452 /* Don't export sysctls to unprivileged users */ 6453 if (net->user_ns != &init_user_ns) 6454 table[1].procname = NULL; 6455 } 6456 6457 return table; 6458 } 6459 6460 size_t ipv6_route_sysctl_table_size(struct net *net) 6461 { 6462 /* Don't export sysctls to unprivileged users */ 6463 if (net->user_ns != &init_user_ns) 6464 return 1; 6465 6466 return ARRAY_SIZE(ipv6_route_table_template); 6467 } 6468 #endif 6469 6470 static int __net_init ip6_route_net_init(struct net *net) 6471 { 6472 int ret = -ENOMEM; 6473 6474 memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template, 6475 sizeof(net->ipv6.ip6_dst_ops)); 6476 6477 if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0) 6478 goto out_ip6_dst_ops; 6479 6480 net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true); 6481 if (!net->ipv6.fib6_null_entry) 6482 goto out_ip6_dst_entries; 6483 memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template, 6484 sizeof(*net->ipv6.fib6_null_entry)); 6485 6486 net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template, 6487 sizeof(*net->ipv6.ip6_null_entry), 6488 GFP_KERNEL); 6489 if (!net->ipv6.ip6_null_entry) 6490 goto out_fib6_null_entry; 6491 net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops; 6492 dst_init_metrics(&net->ipv6.ip6_null_entry->dst, 6493 ip6_template_metrics, true); 6494 INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached); 6495 6496 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6497 net->ipv6.fib6_has_custom_rules = false; 6498 net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template, 6499 sizeof(*net->ipv6.ip6_prohibit_entry), 6500 GFP_KERNEL); 6501 if (!net->ipv6.ip6_prohibit_entry) 6502 goto out_ip6_null_entry; 6503 net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops; 6504 dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst, 6505 ip6_template_metrics, true); 6506 INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached); 6507 6508 net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template, 6509 sizeof(*net->ipv6.ip6_blk_hole_entry), 6510 GFP_KERNEL); 6511 if (!net->ipv6.ip6_blk_hole_entry) 6512 goto out_ip6_prohibit_entry; 6513 net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops; 6514 dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst, 6515 ip6_template_metrics, true); 6516 INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached); 6517 #ifdef CONFIG_IPV6_SUBTREES 6518 net->ipv6.fib6_routes_require_src = 0; 6519 #endif 6520 #endif 6521 6522 net->ipv6.sysctl.flush_delay = 0; 6523 net->ipv6.sysctl.ip6_rt_max_size = INT_MAX; 6524 net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2; 6525 net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ; 6526 net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ; 6527 net->ipv6.sysctl.ip6_rt_gc_elasticity = 9; 6528 net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ; 6529 net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; 6530 net->ipv6.sysctl.skip_notify_on_dev_down = 0; 6531 6532 atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ); 6533 6534 ret = 0; 6535 out: 6536 return ret; 6537 6538 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6539 out_ip6_prohibit_entry: 6540 kfree(net->ipv6.ip6_prohibit_entry); 6541 out_ip6_null_entry: 6542 kfree(net->ipv6.ip6_null_entry); 6543 #endif 6544 out_fib6_null_entry: 6545 kfree(net->ipv6.fib6_null_entry); 6546 out_ip6_dst_entries: 6547 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 6548 out_ip6_dst_ops: 6549 goto out; 6550 } 6551 6552 static void __net_exit ip6_route_net_exit(struct net *net) 6553 { 6554 kfree(net->ipv6.fib6_null_entry); 6555 kfree(net->ipv6.ip6_null_entry); 6556 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6557 kfree(net->ipv6.ip6_prohibit_entry); 6558 kfree(net->ipv6.ip6_blk_hole_entry); 6559 #endif 6560 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 6561 } 6562 6563 static int __net_init ip6_route_net_init_late(struct net *net) 6564 { 6565 #ifdef CONFIG_PROC_FS 6566 if (!proc_create_net("ipv6_route", 0, net->proc_net, 6567 &ipv6_route_seq_ops, 6568 sizeof(struct ipv6_route_iter))) 6569 return -ENOMEM; 6570 6571 if (!proc_create_net_single("rt6_stats", 0444, net->proc_net, 6572 rt6_stats_seq_show, NULL)) { 6573 remove_proc_entry("ipv6_route", net->proc_net); 6574 return -ENOMEM; 6575 } 6576 #endif 6577 return 0; 6578 } 6579 6580 static void __net_exit ip6_route_net_exit_late(struct net *net) 6581 { 6582 #ifdef CONFIG_PROC_FS 6583 remove_proc_entry("ipv6_route", net->proc_net); 6584 remove_proc_entry("rt6_stats", net->proc_net); 6585 #endif 6586 } 6587 6588 static struct pernet_operations ip6_route_net_ops = { 6589 .init = ip6_route_net_init, 6590 .exit = ip6_route_net_exit, 6591 }; 6592 6593 static int __net_init ipv6_inetpeer_init(struct net *net) 6594 { 6595 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 6596 6597 if (!bp) 6598 return -ENOMEM; 6599 inet_peer_base_init(bp); 6600 net->ipv6.peers = bp; 6601 return 0; 6602 } 6603 6604 static void __net_exit ipv6_inetpeer_exit(struct net *net) 6605 { 6606 struct inet_peer_base *bp = net->ipv6.peers; 6607 6608 net->ipv6.peers = NULL; 6609 inetpeer_invalidate_tree(bp); 6610 kfree(bp); 6611 } 6612 6613 static struct pernet_operations ipv6_inetpeer_ops = { 6614 .init = ipv6_inetpeer_init, 6615 .exit = ipv6_inetpeer_exit, 6616 }; 6617 6618 static struct pernet_operations ip6_route_net_late_ops = { 6619 .init = ip6_route_net_init_late, 6620 .exit = ip6_route_net_exit_late, 6621 }; 6622 6623 static struct notifier_block ip6_route_dev_notifier = { 6624 .notifier_call = ip6_route_dev_notify, 6625 .priority = ADDRCONF_NOTIFY_PRIORITY - 10, 6626 }; 6627 6628 void __init ip6_route_init_special_entries(void) 6629 { 6630 /* Registering of the loopback is done before this portion of code, 6631 * the loopback reference in rt6_info will not be taken, do it 6632 * manually for init_net */ 6633 init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev; 6634 init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev; 6635 init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 6636 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6637 init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev; 6638 init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 6639 init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev; 6640 init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 6641 #endif 6642 } 6643 6644 #if IS_BUILTIN(CONFIG_IPV6) 6645 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 6646 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt) 6647 6648 BTF_ID_LIST(btf_fib6_info_id) 6649 BTF_ID(struct, fib6_info) 6650 6651 static const struct bpf_iter_seq_info ipv6_route_seq_info = { 6652 .seq_ops = &ipv6_route_seq_ops, 6653 .init_seq_private = bpf_iter_init_seq_net, 6654 .fini_seq_private = bpf_iter_fini_seq_net, 6655 .seq_priv_size = sizeof(struct ipv6_route_iter), 6656 }; 6657 6658 static struct bpf_iter_reg ipv6_route_reg_info = { 6659 .target = "ipv6_route", 6660 .ctx_arg_info_size = 1, 6661 .ctx_arg_info = { 6662 { offsetof(struct bpf_iter__ipv6_route, rt), 6663 PTR_TO_BTF_ID_OR_NULL }, 6664 }, 6665 .seq_info = &ipv6_route_seq_info, 6666 }; 6667 6668 static int __init bpf_iter_register(void) 6669 { 6670 ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id; 6671 return bpf_iter_reg_target(&ipv6_route_reg_info); 6672 } 6673 6674 static void bpf_iter_unregister(void) 6675 { 6676 bpf_iter_unreg_target(&ipv6_route_reg_info); 6677 } 6678 #endif 6679 #endif 6680 6681 int __init ip6_route_init(void) 6682 { 6683 int ret; 6684 int cpu; 6685 6686 ret = -ENOMEM; 6687 ip6_dst_ops_template.kmem_cachep = 6688 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0, 6689 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL); 6690 if (!ip6_dst_ops_template.kmem_cachep) 6691 goto out; 6692 6693 ret = dst_entries_init(&ip6_dst_blackhole_ops); 6694 if (ret) 6695 goto out_kmem_cache; 6696 6697 ret = register_pernet_subsys(&ipv6_inetpeer_ops); 6698 if (ret) 6699 goto out_dst_entries; 6700 6701 ret = register_pernet_subsys(&ip6_route_net_ops); 6702 if (ret) 6703 goto out_register_inetpeer; 6704 6705 ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep; 6706 6707 ret = fib6_init(); 6708 if (ret) 6709 goto out_register_subsys; 6710 6711 ret = xfrm6_init(); 6712 if (ret) 6713 goto out_fib6_init; 6714 6715 ret = fib6_rules_init(); 6716 if (ret) 6717 goto xfrm6_init; 6718 6719 ret = register_pernet_subsys(&ip6_route_net_late_ops); 6720 if (ret) 6721 goto fib6_rules_init; 6722 6723 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE, 6724 inet6_rtm_newroute, NULL, 0); 6725 if (ret < 0) 6726 goto out_register_late_subsys; 6727 6728 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE, 6729 inet6_rtm_delroute, NULL, 0); 6730 if (ret < 0) 6731 goto out_register_late_subsys; 6732 6733 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, 6734 inet6_rtm_getroute, NULL, 6735 RTNL_FLAG_DOIT_UNLOCKED); 6736 if (ret < 0) 6737 goto out_register_late_subsys; 6738 6739 ret = register_netdevice_notifier(&ip6_route_dev_notifier); 6740 if (ret) 6741 goto out_register_late_subsys; 6742 6743 #if IS_BUILTIN(CONFIG_IPV6) 6744 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 6745 ret = bpf_iter_register(); 6746 if (ret) 6747 goto out_register_late_subsys; 6748 #endif 6749 #endif 6750 6751 for_each_possible_cpu(cpu) { 6752 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); 6753 6754 INIT_LIST_HEAD(&ul->head); 6755 INIT_LIST_HEAD(&ul->quarantine); 6756 spin_lock_init(&ul->lock); 6757 } 6758 6759 out: 6760 return ret; 6761 6762 out_register_late_subsys: 6763 rtnl_unregister_all(PF_INET6); 6764 unregister_pernet_subsys(&ip6_route_net_late_ops); 6765 fib6_rules_init: 6766 fib6_rules_cleanup(); 6767 xfrm6_init: 6768 xfrm6_fini(); 6769 out_fib6_init: 6770 fib6_gc_cleanup(); 6771 out_register_subsys: 6772 unregister_pernet_subsys(&ip6_route_net_ops); 6773 out_register_inetpeer: 6774 unregister_pernet_subsys(&ipv6_inetpeer_ops); 6775 out_dst_entries: 6776 dst_entries_destroy(&ip6_dst_blackhole_ops); 6777 out_kmem_cache: 6778 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 6779 goto out; 6780 } 6781 6782 void ip6_route_cleanup(void) 6783 { 6784 #if IS_BUILTIN(CONFIG_IPV6) 6785 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 6786 bpf_iter_unregister(); 6787 #endif 6788 #endif 6789 unregister_netdevice_notifier(&ip6_route_dev_notifier); 6790 unregister_pernet_subsys(&ip6_route_net_late_ops); 6791 fib6_rules_cleanup(); 6792 xfrm6_fini(); 6793 fib6_gc_cleanup(); 6794 unregister_pernet_subsys(&ipv6_inetpeer_ops); 6795 unregister_pernet_subsys(&ip6_route_net_ops); 6796 dst_entries_destroy(&ip6_dst_blackhole_ops); 6797 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 6798 } 6799